Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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Article

32 pages, 16488 KiB  
Article
Local Control Model of a Human Ventricular Myocyte: An Exploration of Frequency-Dependent Changes and Calcium Sparks
by Jerome Anthony E. Alvarez, M. Saleet Jafri and Aman Ullah
Biomolecules 2023, 13(8), 1259; https://doi.org/10.3390/biom13081259 - 17 Aug 2023
Viewed by 2321
Abstract
Calcium (Ca2+) sparks are the elementary events of excitation–contraction coupling, yet they are not explicitly represented in human ventricular myocyte models. A stochastic ventricular cardiomyocyte human model that adapts to intracellular Ca2+ ([Ca2+]i) dynamics, spark regulation, [...] Read more.
Calcium (Ca2+) sparks are the elementary events of excitation–contraction coupling, yet they are not explicitly represented in human ventricular myocyte models. A stochastic ventricular cardiomyocyte human model that adapts to intracellular Ca2+ ([Ca2+]i) dynamics, spark regulation, and frequency-dependent changes in the form of locally controlled Ca2+ release was developed. The 20,000 CRUs in this model are composed of 9 individual LCCs and 49 RyRs that function as couplons. The simulated action potential duration at 1 Hz steady-state pacing is ~0.280 s similar to human ventricular cell recordings. Rate-dependence experiments reveal that APD shortening mechanisms are largely contributed by the L-type calcium channel inactivation, RyR open fraction, and [Ca2+]myo concentrations. The dynamic slow-rapid-slow pacing protocol shows that RyR open probability during high pacing frequency (2.5 Hz) switches to an adapted “nonconducting” form of Ca2+-dependent transition state. The predicted force was also observed to be increased in high pacing, but the SR Ca2+ fractional release was lower due to the smaller difference between diastolic and systolic [Ca2+]SR. Restitution analysis through the S1S2 protocol and increased LCC Ca2+-dependent activation rate show that the duration of LCC opening helps modulate its effects on the APD restitution at different diastolic intervals. Ultimately, a longer duration of calcium sparks was observed in relation to the SR Ca2+ loading at high pacing rates. Overall, this study demonstrates the spontaneous Ca2+ release events and ion channel responses throughout various stimuli. Full article
(This article belongs to the Special Issue Computational Insights into Calcium Signaling)
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19 pages, 6423 KiB  
Article
Circulating H3K27 Methylated Nucleosome Plasma Concentration: Synergistic Information with Circulating Tumor DNA Molecular Profiling
by Emmanuel Grolleau, Julie Candiracci, Gaelle Lescuyer, David Barthelemy, Nazim Benzerdjeb, Christine Haon, Florence Geiguer, Margaux Raffin, Nathalie Hardat, Julie Balandier, Rémi Rabeuf, Lara Chalabreysse, Anne-Sophie Wozny, Guillaume Rommelaere, Claire Rodriguez-Lafrasse, Fabien Subtil, Sébastien Couraud, Marielle Herzog and Lea Payen-Gay
Biomolecules 2023, 13(8), 1255; https://doi.org/10.3390/biom13081255 - 16 Aug 2023
Cited by 2 | Viewed by 1796
Abstract
The molecular profiling of circulating tumor DNA (ctDNA) is a helpful tool not only in cancer treatment, but also in the early detection of relapse. However, the clinical interpretation of a ctDNA negative result remains challenging. The characterization of circulating nucleosomes (carrying cell-free [...] Read more.
The molecular profiling of circulating tumor DNA (ctDNA) is a helpful tool not only in cancer treatment, but also in the early detection of relapse. However, the clinical interpretation of a ctDNA negative result remains challenging. The characterization of circulating nucleosomes (carrying cell-free DNA) and associated epigenetic modifications (playing a key role in the tumorigenesis of different cancers) may provide useful information for patient management, by supporting the contributive value of ctDNA molecular profiling. Significantly elevated concentrations of H3K27Me3 nucleosomes were found in plasmas at the diagnosis, and during the follow-up, of NSCLC patients, compared to healthy donors (p-value < 0.0001). By combining the H3K27Me3 level and the ctDNA molecular profile, we found that 25.5% of the patients had H3K27Me3 levels above the cut off, and no somatic alteration was detected at diagnosis. This strongly supports the presence of non-mutated ctDNA in the corresponding plasma. During the patient follow-up, a high H3K27Me3-nucleosome level was found in 15.1% of the sample, despite no somatic mutations being detected, allowing the identification of disease progression from 43.1% to 58.2% over molecular profiling alone. Measuring H3K27Me3-nucleosome levels in combination with ctDNA molecular profiling may improve confidence in the negative molecular result for cfDNA in lung cancer at diagnosis, and may also be a promising biomarker for molecular residual disease (MRD) monitoring, during and/or after treatment. Full article
(This article belongs to the Collection Feature Papers in Molecular Biomarkers)
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17 pages, 1341 KiB  
Article
Long-Term Culturing of FreeStyle 293-F Cells Affects Immunoglobulin G Glycome Composition
by Fran Lukšić, Anika Mijakovac, Goran Josipović, Vedrana Vičić Bočkor, Jasminka Krištić, Ana Cindrić, Martina Vinicki, Filip Rokić, Oliver Vugrek, Gordan Lauc and Vlatka Zoldoš
Biomolecules 2023, 13(8), 1245; https://doi.org/10.3390/biom13081245 - 14 Aug 2023
Viewed by 1991
Abstract
Glycosylation of IgG regulates the effector function of this antibody in the immune response. Glycosylated IgG is a potent therapeutic used for both research and clinical purposes. While there is ample research on how different cell culture conditions affect IgG glycosylation, the data [...] Read more.
Glycosylation of IgG regulates the effector function of this antibody in the immune response. Glycosylated IgG is a potent therapeutic used for both research and clinical purposes. While there is ample research on how different cell culture conditions affect IgG glycosylation, the data are missing on the stability of IgG glycome during long cell passaging, i.e., cell “aging”. To test this, we performed three independent time course experiments in FreeStyle 293-F cells, which secrete IgG with a human-like glycosylation pattern and are frequently used to generate defined IgG glycoforms. During long-term cell culturing, IgG glycome stayed fairly stable except for galactosylation, which appeared extremely variable. Cell transcriptome analysis revealed no correlation in galactosyltransferase B4GALT1 expression with galactosylation change, but with expression of EEF1A1 and SLC38A10, genes previously associated with IgG galactosylation through GWAS. The FreeStyle 293-F cell-based system for IgG production is a good model for studies of mechanisms underlying IgG glycosylation, but results from the present study point to the utmost importance of the need to control IgG galactosylation in both in vitro and in vivo systems. This is especially important for improving the production of precisely glycosylated IgG for therapeutic purposes, since IgG galactosylation affects the inflammatory potential of IgG. Full article
(This article belongs to the Special Issue Protein Glycosylation and Human Diseases)
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11 pages, 7420 KiB  
Article
AlphaFold Accurately Predicts the Structure of Ribosomally Synthesized and Post-Translationally Modified Peptide Biosynthetic Enzymes
by Catriona H. Gordon, Emily Hendrix, Yi He and Mark C. Walker
Biomolecules 2023, 13(8), 1243; https://doi.org/10.3390/biom13081243 - 12 Aug 2023
Viewed by 1994
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a growing class of natural products biosynthesized from a genetically encoded precursor peptide. The enzymes that install the post-translational modifications on these peptides have the potential to be useful catalysts in the production of natural-product-like [...] Read more.
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a growing class of natural products biosynthesized from a genetically encoded precursor peptide. The enzymes that install the post-translational modifications on these peptides have the potential to be useful catalysts in the production of natural-product-like compounds and can install non-proteogenic amino acids in peptides and proteins. However, engineering these enzymes has been somewhat limited, due in part to limited structural information on enzymes in the same families that nonetheless exhibit different substrate selectivities. Despite AlphaFold2’s superior performance in single-chain protein structure prediction, its multimer version lacks accuracy and requires high-end GPUs, which are not typically available to most research groups. Additionally, the default parameters of AlphaFold2 may not be optimal for predicting complex structures like RiPP biosynthetic enzymes, due to their dynamic binding and substrate-modifying mechanisms. This study assessed the efficacy of the structure prediction program ColabFold (a variant of AlphaFold2) in modeling RiPP biosynthetic enzymes in both monomeric and dimeric forms. After extensive benchmarking, it was found that there were no statistically significant differences in the accuracy of the predicted structures, regardless of the various possible prediction parameters that were examined, and that with the default parameters, ColabFold was able to produce accurate models. We then generated additional structural predictions for select RiPP biosynthetic enzymes from multiple protein families and biosynthetic pathways. Our findings can serve as a reference for future enzyme engineering complemented by AlphaFold-related tools. Full article
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19 pages, 6804 KiB  
Article
Hidden Glutathione Transferases in the Human Genome
by Aaron J. Oakley
Biomolecules 2023, 13(8), 1240; https://doi.org/10.3390/biom13081240 - 12 Aug 2023
Cited by 2 | Viewed by 1341
Abstract
With the development of accurate protein structure prediction algorithms, artificial intelligence (AI) has emerged as a powerful tool in the field of structural biology. AI-based algorithms have been used to analyze large amounts of protein sequence data including the human proteome, complementing experimental [...] Read more.
With the development of accurate protein structure prediction algorithms, artificial intelligence (AI) has emerged as a powerful tool in the field of structural biology. AI-based algorithms have been used to analyze large amounts of protein sequence data including the human proteome, complementing experimental structure data found in resources such as the Protein Data Bank. The EBI AlphaFold Protein Structure Database (for example) contains over 230 million structures. In this study, these data have been analyzed to find all human proteins containing (or predicted to contain) the cytosolic glutathione transferase (cGST) fold. A total of 39 proteins were found, including the alpha-, mu-, pi-, sigma-, zeta- and omega-class GSTs, intracellular chloride channels, metaxins, multisynthetase complex components, elongation factor 1 complex components and others. Three broad themes emerge: cGST domains as enzymes, as chloride ion channels and as protein–protein interaction mediators. As the majority of cGSTs are dimers, the AI-based structure prediction algorithm AlphaFold-multimer was used to predict structures of all pairwise combinations of these cGST domains. Potential homo- and heterodimers are described. Experimental biochemical and structure data is used to highlight the strengths and limitations of AI-predicted structures. Full article
(This article belongs to the Special Issue Versatility of Glutathione Transferase Proteins)
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14 pages, 5715 KiB  
Article
Graph-Based Analyses of Dynamic Water-Mediated Hydrogen-Bond Networks in Phosphatidylserine: Cholesterol Membranes
by Honey Jain, Konstantina Karathanou and Ana-Nicoleta Bondar
Biomolecules 2023, 13(8), 1238; https://doi.org/10.3390/biom13081238 - 11 Aug 2023
Cited by 1 | Viewed by 1373
Abstract
Phosphatidylserine lipids are anionic molecules present in eukaryotic plasma membranes, where they have essential physiological roles. The altered distribution of phosphatidylserine in cells such as apoptotic cancer cells, which, unlike healthy cells, expose phosphatidylserine, is of direct interest for the development of biomarkers. [...] Read more.
Phosphatidylserine lipids are anionic molecules present in eukaryotic plasma membranes, where they have essential physiological roles. The altered distribution of phosphatidylserine in cells such as apoptotic cancer cells, which, unlike healthy cells, expose phosphatidylserine, is of direct interest for the development of biomarkers. We present here applications of a recently implemented Depth-First-Search graph algorithm to dissect the dynamics of transient water-mediated lipid clusters at the interface of a model bilayer composed of 1-palmytoyl-2-oleoyl-sn-glycero-2-phosphatidylserine (POPS) and cholesterol. Relative to a reference POPS bilayer without cholesterol, in the POPS:cholesterol bilayer there is a somewhat less frequent sampling of relatively complex and extended water-mediated hydrogen-bond networks of POPS headgroups. The analysis protocol used here is more generally applicable to other lipid:cholesterol bilayers. Full article
(This article belongs to the Special Issue Proton and Proton-Coupled Transport)
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29 pages, 3802 KiB  
Article
The Impact of Viral Infection on the Chemistries of the Earth’s Most Abundant Photosynthesizes: Metabolically Talented Aquatic Cyanobacteria
by Yunpeng Wang, Scarlet Ferrinho, Helen Connaris and Rebecca J. M. Goss
Biomolecules 2023, 13(8), 1218; https://doi.org/10.3390/biom13081218 - 4 Aug 2023
Cited by 2 | Viewed by 1691
Abstract
Cyanobacteria are the most abundant photosynthesizers on earth, and as such, they play a central role in marine metabolite generation, ocean nutrient cycling, and the control of planetary oxygen generation. Cyanobacteriophage infection exerts control on all of these critical processes of the planet, [...] Read more.
Cyanobacteria are the most abundant photosynthesizers on earth, and as such, they play a central role in marine metabolite generation, ocean nutrient cycling, and the control of planetary oxygen generation. Cyanobacteriophage infection exerts control on all of these critical processes of the planet, with the phage-ported homologs of genes linked to photosynthesis, catabolism, and secondary metabolism (marine metabolite generation). Here, we analyze the 153 fully sequenced cyanophages from the National Center for Biotechnology Information (NCBI) database and the 45 auxiliary metabolic genes (AMGs) that they deliver into their hosts. Most of these AMGs are homologs of those found within cyanobacteria and play a key role in cyanobacterial metabolism-encoding proteins involved in photosynthesis, central carbon metabolism, phosphate metabolism, methylation, and cellular regulation. A greater understanding of cyanobacteriophage infection will pave the way to a better understanding of carbon fixation and nutrient cycling, as well as provide new tools for synthetic biology and alternative approaches for the use of cyanobacteria in biotechnology and sustainable manufacturing. Full article
(This article belongs to the Special Issue Marine-Derived Molecules with Different Bioactivities)
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16 pages, 2091 KiB  
Article
Phosphoserine Aminotransferase Pathogenetic Variants in Serine Deficiency Disorders: A Functional Characterization
by Francesco Marchesani, Annalisa Michielon, Elisabetta Viale, Annalisa Bianchera, Davide Cavazzini, Loredano Pollegioni, Giulia Murtas, Andrea Mozzarelli, Stefano Bettati, Alessio Peracchi, Barbara Campanini and Stefano Bruno
Biomolecules 2023, 13(8), 1219; https://doi.org/10.3390/biom13081219 - 4 Aug 2023
Cited by 1 | Viewed by 1161
Abstract
In humans, the phosphorylated pathway (PP) converts the glycolytic intermediate D-3-phosphoglycerate (3-PG) into L-serine through the enzymes 3-phosphoglycerate dehydrogenase, phosphoserine aminotransferase (PSAT) and phosphoserine phosphatase. From the pathogenic point of view, the PP in the brain is particularly relevant, as genetic defects of [...] Read more.
In humans, the phosphorylated pathway (PP) converts the glycolytic intermediate D-3-phosphoglycerate (3-PG) into L-serine through the enzymes 3-phosphoglycerate dehydrogenase, phosphoserine aminotransferase (PSAT) and phosphoserine phosphatase. From the pathogenic point of view, the PP in the brain is particularly relevant, as genetic defects of any of the three enzymes are associated with a group of neurometabolic disorders known as serine deficiency disorders (SDDs). We recombinantly expressed and characterized eight variants of PSAT associated with SDDs and two non-SDD associated variants. We show that the pathogenetic mechanisms in SDDs are extremely diverse, including low affinity of the cofactor pyridoxal 5′-phosphate and thermal instability for S179L and G79W PSAT, loss of activity of the holo form for R342W PSAT, aggregation for D100A PSAT, increased Km for one of the substrates with invariant kcats for S43R PSAT, and a combination of increased Km and decreased kcat for C245R PSAT. Finally, we show that the flux through the in vitro reconstructed PP at physiological concentrations of substrates and enzymes is extremely sensitive to alterations of the functional properties of PSAT variants, confirming PSAT dysfunctions as a cause of SSDs. Full article
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14 pages, 35695 KiB  
Article
Del1 Is a Growth Factor for Skeletal Progenitor Cells in the Fracture Callus
by Yuxi Sun, Tatiana Boyko, Owen Marecic, Danielle Struck, Randall K. Mann, Tom W. Andrew, Michael Lopez, Xinming Tong, Stuart B. Goodman, Fan Yang, Michael T. Longaker, Charles K. F. Chan and George P. Yang
Biomolecules 2023, 13(8), 1214; https://doi.org/10.3390/biom13081214 - 3 Aug 2023
Viewed by 1723
Abstract
Failure to properly form bone or integrate surgical implants can lead to morbidity and additional surgical interventions in a significant proportion of orthopedic surgeries. While the role of skeletal stem cells (SSCs) in bone formation and repair is well-established, very little is known [...] Read more.
Failure to properly form bone or integrate surgical implants can lead to morbidity and additional surgical interventions in a significant proportion of orthopedic surgeries. While the role of skeletal stem cells (SSCs) in bone formation and repair is well-established, very little is known about the factors that regulate the downstream Bone, Cartilage, Stromal, Progenitors (BCSPs). BCSPs, as transit amplifying progenitor cells, undergo multiple mitotic divisions to expand the pool of lineage committed progenitors allowing stem cells to preserve their self-renewal and stemness. Del1 is a protein widely expressed in the skeletal system, but its deletion led to minimal phenotype changes in the uninjured mouse. In this paper, we demonstrate that Del1 is a key regulator of BCSP expansion following injury. In Del1 knockout mice, there is a significant reduction in the number of BCSPs which leads to a smaller callus and decreased bone formation compared with wildtype (WT) littermates. Del1 serves to promote BCSP proliferation and prevent apoptosis in vivo and in vitro. Moreover, exogenous Del1 promotes proliferation of aged human BCSPs. Our results highlight the potential of Del1 as a therapeutic target for improving bone formation and implant success. Del1 injections may improve the success of orthopedic surgeries and fracture healing by enhancing the proliferation and survival of BCSPs, which are crucial for generating new bone tissue during the process of bone formation and repair. Full article
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19 pages, 2480 KiB  
Article
A Combination of Conformation-Specific RAF Inhibitors Overcome Drug Resistance Brought about by RAF Overexpression
by Hiroaki Imoto, Nora Rauch, Ashish J. Neve, Fahimeh Khorsand, Martina Kreileder, Leonidas G. Alexopoulos, Jens Rauch, Mariko Okada, Boris N. Kholodenko and Oleksii S. Rukhlenko
Biomolecules 2023, 13(8), 1212; https://doi.org/10.3390/biom13081212 - 2 Aug 2023
Cited by 1 | Viewed by 2513
Abstract
Cancer cells often adapt to targeted therapies, yet the molecular mechanisms underlying adaptive resistance remain only partially understood. Here, we explore a mechanism of RAS/RAF/MEK/ERK (MAPK) pathway reactivation through the upregulation of RAF isoform (RAFs) abundance. Using computational modeling and in vitro experiments, [...] Read more.
Cancer cells often adapt to targeted therapies, yet the molecular mechanisms underlying adaptive resistance remain only partially understood. Here, we explore a mechanism of RAS/RAF/MEK/ERK (MAPK) pathway reactivation through the upregulation of RAF isoform (RAFs) abundance. Using computational modeling and in vitro experiments, we show that the upregulation of RAFs changes the concentration range of paradoxical pathway activation upon treatment with conformation-specific RAF inhibitors. Additionally, our data indicate that the signaling output upon loss or downregulation of one RAF isoform can be compensated by overexpression of other RAF isoforms. We furthermore demonstrate that, while single RAF inhibitors cannot efficiently inhibit ERK reactivation caused by RAF overexpression, a combination of two structurally distinct RAF inhibitors synergizes to robustly suppress pathway reactivation. Full article
(This article belongs to the Special Issue MAP Kinases: Functions in Signal Transduction and Disease)
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16 pages, 9406 KiB  
Article
CXCL10 Is Associated with Increased Cerebrospinal Fluid Immune Cell Infiltration and Disease Duration in Multiple Sclerosis
by Stephanie N. Blandford, Neva J. Fudge and Craig S. Moore
Biomolecules 2023, 13(8), 1204; https://doi.org/10.3390/biom13081204 - 1 Aug 2023
Cited by 4 | Viewed by 1550
Abstract
Background: Cerebrospinal fluid (CSF) is an important sampling site for putative biomarkers and contains immune cells. CXCL10 is a multiple sclerosis (MS)-relevant chemokine that is present in the injured central nervous system and recruits CXCR3+ immune cells toward injured tissues. Objective: Perform a [...] Read more.
Background: Cerebrospinal fluid (CSF) is an important sampling site for putative biomarkers and contains immune cells. CXCL10 is a multiple sclerosis (MS)-relevant chemokine that is present in the injured central nervous system and recruits CXCR3+ immune cells toward injured tissues. Objective: Perform a comprehensive evaluation to determine a potential relationship between CXCL10 and various immune cell subsets in the CNS of MS and control cases. Methods: In MS and control cases, CXCL10 was measured in the CSF and plasma by ELISA. Immune cells within both the CSF and peripheral blood were quantified by flow cytometry. Results: Compared to non-inflammatory neurological disease (NIND) cases, MS cases had significantly higher CXCL10 in CSF (p = 0.021); CXCL10 was also correlated with total cell numbers in CSF (p = 0.04) and T cell infiltrates (CD3+, p = 0.01; CD4+, p = 0.01; CD8+, p = 0.02); expression of CXCR3 on peripheral immune cell subsets was not associated with CSF CXCL10. Conclusions: Elevated levels of CXCL10 in the CSF of MS cases are associated with increased T cells but appear to be independent of peripheral CXCR3 expression. These results support the importance of elevated CXCL10 in MS and suggest the presence of an alternative mechanism of CXCL10 outside of solely influencing immune cell trafficking. Full article
(This article belongs to the Special Issue New Insights into Neuroimmunology)
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17 pages, 3410 KiB  
Article
Serum Soluble Lectin-like Oxidized Low-Density Lipoprotein Receptor-1 (sLOX-1) Is Associated with Atherosclerosis Severity in Coronary Artery Disease
by Katharine A. Kott, Elijah Genetzakis, Michael P. Gray, Peter Hansen, Helen M. McGuire, Jean Y. Yang, Stuart M. Grieve, Stephen T. Vernon and Gemma A. Figtree
Biomolecules 2023, 13(8), 1187; https://doi.org/10.3390/biom13081187 - 29 Jul 2023
Viewed by 1270
Abstract
Risk-factor-based scoring systems for atherosclerotic coronary artery disease (CAD) remain concerningly inaccurate at the level of the individual and would benefit from the addition of biomarkers that correlate with atherosclerosis burden directly. We hypothesized that serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) [...] Read more.
Risk-factor-based scoring systems for atherosclerotic coronary artery disease (CAD) remain concerningly inaccurate at the level of the individual and would benefit from the addition of biomarkers that correlate with atherosclerosis burden directly. We hypothesized that serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) would be independently associated with CAD and investigated this in the BioHEART study using 968 participants with CT coronary angiograms, which were scored for disease burden in the form of coronary artery calcium scores (CACS), Gensini scores, and a semi-quantitative soft-plaque score (SPS). Serum sLOX-1 was assessed by ELISA and was incorporated into regression models for disease severity and incidence. We demonstrate that sLOX-1 is associated with an improvement in the prediction of CAD severity when scored by Gensini or SPS, but not CACS. sLOX-1 also significantly improved the prediction of the incidence of obstructive CAD, defined as stenosis in any vessel >75%. The predictive value of sLOX-1 was significantly greater in the subgroup of patients who did not have any of the standard modifiable cardiovascular risk factors (SMuRFs). sLOX-1 is associated with CAD severity and is the first biomarker shown to have utility for risk prediction in the SMuRFless population. Full article
(This article belongs to the Special Issue Cardiovascular Diseases and Biomarkers)
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21 pages, 3365 KiB  
Article
Hemocompatibility of β-Cyclodextrin-Modified (Methacryloyloxy)ethyl Phosphorylcholine Coated Magnetic Nanoparticles
by Shuhui Li, Mehdi Ghaffari Sharaf, Elyn M. Rowe, Katherine Serrano, Dana V. Devine and Larry D. Unsworth
Biomolecules 2023, 13(8), 1165; https://doi.org/10.3390/biom13081165 - 25 Jul 2023
Viewed by 1422
Abstract
Adsorbing toxins from the blood to augment membrane-based hemodialysis is an active area of research. Films composed of β-cyclodextrin-co-(methacryloyloxy)ethyl phosphorylcholine (p(PMβCD-co-MPC)) with various monomer ratios were formed on magnetic nanoparticles and characterized. Surface chemistry effects on protein denaturation were evaluated and indicated that [...] Read more.
Adsorbing toxins from the blood to augment membrane-based hemodialysis is an active area of research. Films composed of β-cyclodextrin-co-(methacryloyloxy)ethyl phosphorylcholine (p(PMβCD-co-MPC)) with various monomer ratios were formed on magnetic nanoparticles and characterized. Surface chemistry effects on protein denaturation were evaluated and indicated that unmodified magnetic nanoparticles greatly perturbed the structure of proteins compared to coated particles. Plasma clotting assays were conducted to investigate the stability of plasma in the presence of particles, where a 2:2 monomer ratio yielded the best results for a given total surface area of particles. Total protein adsorption results revealed that modified surfaces exhibited reduced protein adsorption compared to bare particles, and pure MPC showed the lowest adsorption. Immunoblot results showed that fibrinogen, α1-antitrypsin, vitronectin, prekallikrein, antithrombin, albumin, and C3 correlated with film composition. Hemocompatibility testing with whole blood illustrated that the 1:3 ratio of CD to MPC had a negative impact on platelets, as evidenced by the increased activation, reduced response to an agonist, and reduced platelet count. Other formulations had statistically significant effects on platelet activation, but no formulation yielded apparent adverse effects on hemostasis. For the first time, p(PMβCD-co-MPC)-coated MNP were synthesized and their general hemocompatibility assessed. Full article
(This article belongs to the Special Issue Mechanisms and Kinetics of Interactions of Biomolecules at Interfaces)
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17 pages, 3567 KiB  
Article
Goldilocks Dilemma: LPS Works Both as the Initial Target and a Barrier for the Antimicrobial Action of Cationic AMPs on E. coli
by Martin Jakubec, Fredrik G. Rylandsholm, Philip Rainsford, Mitchell Silk, Maxim Bril’kov, Tone Kristoffersen, Eric Juskewitz, Johanna U. Ericson and John Sigurd M. Svendsen
Biomolecules 2023, 13(7), 1155; https://doi.org/10.3390/biom13071155 - 20 Jul 2023
Cited by 5 | Viewed by 2007
Abstract
Antimicrobial peptides (AMPs) are generally membrane-active compounds that physically disrupt bacterial membranes. Despite extensive research, the precise mode of action of AMPs is still a topic of great debate. This work demonstrates that the initial interaction between the Gram-negative E. coli and AMPs [...] Read more.
Antimicrobial peptides (AMPs) are generally membrane-active compounds that physically disrupt bacterial membranes. Despite extensive research, the precise mode of action of AMPs is still a topic of great debate. This work demonstrates that the initial interaction between the Gram-negative E. coli and AMPs is driven by lipopolysaccharides (LPS) that act as kinetic barriers for the binding of AMPs to the bacterial membrane. A combination of SPR and NMR experiments provide evidence suggesting that cationic AMPs first bind to the negatively charged LPS before reaching a binding place in the lipid bilayer. In the event that the initial LPS-binding is too strong (corresponding to a low dissociation rate), the cationic AMPs cannot effectively get from the LPS to the membrane, and their antimicrobial potency will thus be diminished. On the other hand, the AMPs must also be able to effectively interact with the membrane to exert its activity. The ability of the studied cyclic hexapeptides to bind LPS and to translocate into a lipid membrane is related to the nature of the cationic charge (arginine vs. lysine) and to the distribution of hydrophobicity along the molecule (alternating vs. clumped tryptophan). Full article
(This article belongs to the Special Issue Mechanisms and Kinetics of Interactions of Biomolecules at Interfaces)
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23 pages, 14523 KiB  
Article
A Molecular Analysis of the Aminopeptidase P-Related Domain of PID-5 from Caenorhabditis elegans
by Anna C. Lloyd, Kyle S. Gregory, R. Elwyn Isaac and K. Ravi Acharya
Biomolecules 2023, 13(7), 1132; https://doi.org/10.3390/biom13071132 - 14 Jul 2023
Cited by 1 | Viewed by 1826
Abstract
A novel protein, PID-5, has been shown to be a requirement for germline immortality and has recently been implicated in RNA-induced epigenetic silencing in the Caenorhabditis elegans embryo. Importantly, it has been shown to contain both an eTudor and aminopeptidase P-related domain. However, [...] Read more.
A novel protein, PID-5, has been shown to be a requirement for germline immortality and has recently been implicated in RNA-induced epigenetic silencing in the Caenorhabditis elegans embryo. Importantly, it has been shown to contain both an eTudor and aminopeptidase P-related domain. However, the silencing mechanism has not yet been fully characterised. In this study, bioinformatic tools were used to compare pre-existing aminopeptidase P molecular structures to the AlphaFold2-predicted aminopeptidase P-related domain of PID-5 (PID-5 APP-RD). Structural homology, metal composition, inhibitor-bonding interactions, and the potential for dimerisation were critically assessed through computational techniques, including structural superimposition and protein-ligand docking. Results from this research suggest that the metallopeptidase-like domain shares high structural homology with known aminopeptidase P enzymes and possesses the canonical ‘pita-bread fold’. However, the absence of conserved metal-coordinating residues indicates that only a single Zn2+ may be bound at the active site. The PID-5 APP-RD may form transient interactions with a known aminopeptidase P inhibitor and may therefore recognise substrates in a comparable way to the known structures. However, loss of key catalytic residues suggests the domain will be inactive. Further evidence suggests that heterodimerisation with C. elegans aminopeptidase P is feasible and therefore PID-5 is predicted to regulate proteolytic cleavage in the silencing pathway. PID-5 may interact with PID-2 to bring aminopeptidase P activity to the Z-granule, where it could influence WAGO-4 activity to ensure the balanced production of 22G-RNA signals for transgenerational silencing. Targeted experiments into APPs implicated in malaria and cancer are required in order to build upon the biological and therapeutic significance of this research. Full article
(This article belongs to the Topic Metalloproteins and Metalloenzymes)
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11 pages, 5442 KiB  
Article
Design of Beta-2 Microglobulin Adsorbent Protein Nanoparticles
by Justin E. Miller, Roger Castells-Graells, Mark A. Arbing, Aldo Munoz, Yi-Xiao Jiang, Charlize T. Espinoza, Brian Nguyen, Paul Moroz and Todd O. Yeates
Biomolecules 2023, 13(7), 1122; https://doi.org/10.3390/biom13071122 - 14 Jul 2023
Cited by 5 | Viewed by 1977
Abstract
Beta-2 microglobulin (B2M) is an immune system protein that is found on the surface of all nucleated human cells. B2M is naturally shed from cell surfaces into the plasma, followed by renal excretion. In patients with impaired renal function, B2M will accumulate in [...] Read more.
Beta-2 microglobulin (B2M) is an immune system protein that is found on the surface of all nucleated human cells. B2M is naturally shed from cell surfaces into the plasma, followed by renal excretion. In patients with impaired renal function, B2M will accumulate in organs and tissues leading to significantly reduced life expectancy and quality of life. While current hemodialysis methods have been successful in managing electrolyte as well as small and large molecule disturbances arising in chronic renal failure, they have shown only modest success in managing plasma levels of B2M and similar sized proteins, while sparing important proteins such as albumin. We describe a systematic protein design effort aimed at adding the ability to selectively remove specific, undesired waste proteins such as B2M from the plasma of chronic renal failure patients. A novel nanoparticle built using a tetrahedral protein assembly as a scaffold that presents 12 copies of a B2M-binding nanobody is described. The designed nanoparticle binds specifically to B2M through protein–protein interactions with nanomolar binding affinity (~4.2 nM). Notably, binding to the nanoparticle increases the effective size of B2M by over 50-fold, offering a potential selective avenue for separation based on size. We present data to support the potential utility of such a nanoparticle for removing B2M from plasma by either size-based filtration or by polyvalent binding to a stationary matrix under blood flow conditions. Such applications could address current shortcomings in the management of problematic mid-sized proteins in chronic renal failure patients. Full article
(This article belongs to the Section Biomacromolecules: Proteins)
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10 pages, 1211 KiB  
Article
An Integrated Glycosylation Signature of Rheumatoid Arthritis
by Oleg A. Mayboroda, Guinevere S. M. Lageveen-Kammeijer, Manfred Wuhrer and Radboud J. E. M. Dolhain
Biomolecules 2023, 13(7), 1106; https://doi.org/10.3390/biom13071106 - 12 Jul 2023
Viewed by 1325
Abstract
Rheumatoid arthritis (RA) Is a highly prevalent autoimmune disease that affects the joints but also various other organs. The disease is characterized by autoantibodies that are often already observed pre-disease. Since the 1980s, it has been known that antibody glycosylation is different in [...] Read more.
Rheumatoid arthritis (RA) Is a highly prevalent autoimmune disease that affects the joints but also various other organs. The disease is characterized by autoantibodies that are often already observed pre-disease. Since the 1980s, it has been known that antibody glycosylation is different in RA as compared to control individuals. While the literature on glycosylation changes in RA is dominated by reports on serum or plasma immunoglobulin G (IgG), our recent studies have indicated that the glycosylation changes observed for immunoglobulin A (IgA) and total serum N-glycome (TSNG) may be similarly prominent, and useful in differentiating between the RA patients and controls, or as a proxy of the disease activity. In this study, we integrated and compared the RA glycosylation signatures of IgG, IgA and TSNG, all determined in the pregnancy-induced amelioration of rheumatoid arthritis (PARA) cohort. We assessed the association of the altered glycosylation patterns with the disease, autoantibody positivity and disease activity. Our analyses indicated a common, composite glycosylation signature of RA that was independent of the autoantibody status. Full article
(This article belongs to the Special Issue Protein Glycosylation and Human Diseases)
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22 pages, 3658 KiB  
Article
The Metallodrug BOLD-100 Is a Potent Inhibitor of SARS-CoV-2 Replication and Has Broad-Acting Antiviral Activity
by Daniel S. Labach, Hinissan P. Kohio, Edwin A. Tse, Ermela Paparisto, Nicole J. Friesen, Jim Pankovich, Mark Bazett and Stephen D. Barr
Biomolecules 2023, 13(7), 1095; https://doi.org/10.3390/biom13071095 - 8 Jul 2023
Cited by 3 | Viewed by 1879
Abstract
The COVID-19 pandemic has highlighted an urgent need to discover and test new drugs to treat patients. Metal-based drugs are known to interact with DNA and/or a variety of proteins such as enzymes and transcription factors, some of which have been shown to [...] Read more.
The COVID-19 pandemic has highlighted an urgent need to discover and test new drugs to treat patients. Metal-based drugs are known to interact with DNA and/or a variety of proteins such as enzymes and transcription factors, some of which have been shown to exhibit anticancer and antimicrobial effects. BOLD-100 (sodium trans-[tetrachlorobis(1H-indazole)ruthenate(III)]dihydrate) is a novel ruthenium-based drug currently being evaluated in a Phase 1b/2a clinical trial for the treatment of advanced gastrointestinal cancer. Given that metal-based drugs are known to exhibit antimicrobial activities, we asked if BOLD-100 exhibits antiviral activity towards SARS-CoV-2. We demonstrated that BOLD-100 potently inhibits SARS-CoV-2 replication and cytopathic effects in vitro. An RNA sequencing analysis showed that BOLD-100 inhibits virus-induced transcriptional changes in infected cells. In addition, we showed that the antiviral activity of BOLD-100 is not specific for SARS-CoV-2, but also inhibits the replication of the evolutionarily divergent viruses Human Immunodeficiency Virus type 1 and Human Adenovirus type 5. This study identifies BOLD-100 as a potentially novel broad-acting antiviral drug. Full article
(This article belongs to the Special Issue Viral Drug Targets and Discovery of Antiviral Agents)
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23 pages, 1444 KiB  
Article
Xanthine–Dopamine Hybrid Molecules as Multitarget Drugs with Potential for the Treatment of Neurodegenerative Diseases
by Michał Załuski, Tadeusz Karcz, Anna Drabczyńska, Christin Vielmuth, Agnieszka Olejarz-Maciej, Monika Głuch-Lutwin, Barbara Mordyl, Agata Siwek, Grzegorz Satała, Christa E. Müller and Katarzyna Kieć-Kononowicz
Biomolecules 2023, 13(7), 1079; https://doi.org/10.3390/biom13071079 - 5 Jul 2023
Cited by 3 | Viewed by 1812
Abstract
Multitarget drugs based on a hybrid dopamine–xanthine core were designed as potential drug candidates for the treatment of neurodegenerative diseases. Monoamine oxidase B (MAO-B) inhibitors with significant ancillary A2A adenosine receptor (A2AAR) antagonistic properties were further developed to exhibit additional [...] Read more.
Multitarget drugs based on a hybrid dopamine–xanthine core were designed as potential drug candidates for the treatment of neurodegenerative diseases. Monoamine oxidase B (MAO-B) inhibitors with significant ancillary A2A adenosine receptor (A2AAR) antagonistic properties were further developed to exhibit additional phosphodiesterase-4 and -10 (PDE4/10) inhibition and/or dopamine D2 receptor (D2R) agonistic activity. While all of the designed compounds showed MAO-B inhibition in the nanomolar range mostly combined with submicromolar A2AAR affinity, significant enhancement of PDE-inhibitory and D2R-agonistic activity was additionally reached for some compounds through various structural modifications. The final multitarget drugs also showed promising antioxidant properties in vitro. In order to evaluate their potential neuroprotective effect, representative ligands were tested in a cellular model of toxin-induced neurotoxicity. As a result, protective effects against oxidative stress in neuroblastoma cells were observed, confirming the utility of the applied strategy. Further evaluation of the newly developed multitarget ligands in preclinical models of Alzheimer’s and Parkinson’s diseases is warranted. Full article
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18 pages, 2548 KiB  
Article
Activation of Metabotropic Glutamate Receptor (mGlu2) and Muscarinic Receptors (M1, M4, and M5), Alone or in Combination, and Its Impact on the Acquisition and Retention of Learning in the Morris Water Maze, NMDA Expression and cGMP Synthesis
by Joanna M. Wierońska, Paulina Cieślik, Grzegorz Burnat and Leszek Kalinowski
Biomolecules 2023, 13(7), 1064; https://doi.org/10.3390/biom13071064 - 30 Jun 2023
Cited by 4 | Viewed by 1679
Abstract
The Morris water maze (MWM) is regarded as one of the most popular tests for detecting spatial memory in rodents. Long-term potentiation and cGMP synthesis seem to be among the crucial factors involved in this type of learning. Muscarinic (M1, M [...] Read more.
The Morris water maze (MWM) is regarded as one of the most popular tests for detecting spatial memory in rodents. Long-term potentiation and cGMP synthesis seem to be among the crucial factors involved in this type of learning. Muscarinic (M1, M4, and M5 receptors) and metabotropic glutamate (mGlu) receptors are important targets in the search for antipsychotic drugs with the potency to treat cognitive disabilities associated with the disorder. Here, we show that muscarinic receptor activators (VU0357017, VU0152100, and VU0238429) and an mGlu2 receptor activator, LY487379, dose-dependently prevented the development of cognitive disorders as a result of MK-801 administration in the MWM. The dose-ranges of the compounds were as follows: VU0357017, 0.25, 0.5, and 1 mg/kg; VU0152100, 0.05, 0.25, and 1 mg/kg; VU0238429, 1, 5, and 20 mg/kg; and LY487379, 0.5, 3, and 5 mg/kg. The co-administration of LY487379 with each of the individual muscarinic receptor ligands showed no synergistic effect, which contradicts the results obtained earlier in the novel object recognition (NOR) test. MWM learning resulted in increased cGMP synthesis, both in the cortex and hippocampi, when compared to that in intact animals, which was prevented by MK-801 administration. The investigated compounds at the highest doses reversed this MK-801-induced effect. Neither the procedure nor the treatment resulted in changes in GluN2B-NMDA expression. Full article
(This article belongs to the Special Issue Glutamate and Glutamate Receptors in Health and Diseases)
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23 pages, 9441 KiB  
Article
Quantitative Spatial Analysis of Neuroligin-3 mRNA Expression in the Enteric Nervous System Reveals a Potential Role in Neuronal–Glial Synapses and Reduced Expression in Nlgn3R451C Mice
by Madushani Herath, Ellie Cho, Ulrika Marklund, Ashley E. Franks, Joel C. Bornstein and Elisa L. Hill-Yardin
Biomolecules 2023, 13(7), 1063; https://doi.org/10.3390/biom13071063 - 30 Jun 2023
Cited by 3 | Viewed by 1811
Abstract
Mutations in the Neuroligin-3 (Nlgn3) gene are implicated in autism spectrum disorder (ASD) and gastrointestinal (GI) dysfunction, but cellular Nlgn3 expression in the enteric nervous system remains to be characterised. We combined RNAScope in situ hybridization and immunofluorescence to measure Nlgn3 [...] Read more.
Mutations in the Neuroligin-3 (Nlgn3) gene are implicated in autism spectrum disorder (ASD) and gastrointestinal (GI) dysfunction, but cellular Nlgn3 expression in the enteric nervous system remains to be characterised. We combined RNAScope in situ hybridization and immunofluorescence to measure Nlgn3 mRNA expression in cholinergic and VIP-expressing submucosal neurons, nitrergic and calretinin-containing myenteric neurons and glial cells in both WT and Nlgn3R451C mutant mice. We measured Nlgn3 mRNA neuronal and glial expression via quantitative three-dimensional image analysis. To validate dual RNAScope/immunofluorescence data, we interrogated available single-cell RNA sequencing (scRNASeq) data to assess for Nlgn3, Nlgn1, Nlgn2 and their binding partners, Nrxn1-3, MGDA1 and MGDA2, in enteric neural subsets. Most submucosal and myenteric neurons expressed Nlgn3 mRNA. In contrast to other Nlgns and binding partners, Nlgn3 was strongly expressed in enteric glia, suggesting a role for neuroligin-3 in mediating enteric neuron–glia interactions. The autism-associated R451C mutation reduces Nlgn3 mRNA expression in cholinergic but not in VIPergic submucosal neurons. In the myenteric plexus, Nlgn3 mRNA levels are reduced in calretinin, nNOS-labelled neurons and S100 β -labelled glia. We provide a comprehensive cellular profile for neuroligin-3 expression in ileal neuronal subpopulations of mice expressing the R451C autism-associated mutation in Nlgn3, which may contribute to the understanding of the pathophysiology of GI dysfunction in ASD. Full article
(This article belongs to the Special Issue Neuroimmune Interactions in Neuropsychiatric Diseases)
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23 pages, 4070 KiB  
Article
Bioinspired Synthesis of Silver Nanoparticles for the Remediation of Toxic Pollutants and Enhanced Antibacterial Activity
by Sujata Mandal, Sangchul Hwang, Sreekar B. Marpu, Mohammad A. Omary, Victor Prybutok and Sheldon Q. Shi
Biomolecules 2023, 13(7), 1054; https://doi.org/10.3390/biom13071054 - 29 Jun 2023
Cited by 5 | Viewed by 1697
Abstract
This research presents a novel and environmentally friendly approach for the synthesis of multifunctional nanobiocomposites for the efficient removal of toxic heavy metal and dye, as well as the disinfection of wastewater microorganisms. The nanobiocomposites (KAC-CS-AgNPs) were prepared by incorporating photochemically generated silver [...] Read more.
This research presents a novel and environmentally friendly approach for the synthesis of multifunctional nanobiocomposites for the efficient removal of toxic heavy metal and dye, as well as the disinfection of wastewater microorganisms. The nanobiocomposites (KAC-CS-AgNPs) were prepared by incorporating photochemically generated silver nanoparticles (AgNPs) within a chitosan (CS)-modified, high-surface-area activated carbon derived from kenaf (KAC), using a unique self-activation method. The even distribution of AgNPs was visible in the scanning electron microscopy images and a Fourier transform infra red study demonstrated major absorption peaks. The experimental results revealed that KA-CS-AgNPs exhibited exceptional adsorption efficiency for copper (Cu2+), lead (Pb2+), and Congo Red dye (CR), and showed potent antibacterial activity against Staphylococcus aureus and Escherichia coli. The maximum adsorption capacity (mg g−1) of KAC-CS-AgNPs was 71.5 for Cu2+, 72.3 for Pb2+, and 75.9 for CR, and the adsorption phenomena followed on the Freundlich and Langmuir isotherm models and the second-order kinetic model (R2 > 0.99). KAC-CS-AgNPs also exhibited excellent reusability of up to four consecutive cycles with minor losses in adsorption ability. The thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic in nature. The bacterial inactivation tests demonstrated that KAC-CS-AgNPs had a strong bactericidal effect on both E. coli and S. aureus, with MIC calculated for E. coli and S. aureus as 32 µg mL−1 and 44 µg mL−1, respectively. The synthesized bioinspired nanocomposite KAC-CS-AgNPs could be an innovative solution for effective and sustainable wastewater treatment and has great potential for commercial applications. Full article
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18 pages, 2809 KiB  
Article
Tissue Inhibitor of Matrix Metalloproteinases-1 (TIMP-1) and Pulmonary Involvement in COVID-19 Pneumonia
by Maria Antonella Zingaropoli, Tiziana Latronico, Patrizia Pasculli, Giorgio Maria Masci, Roberta Merz, Federica Ciccone, Federica Dominelli, Cosmo Del Borgo, Miriam Lichtner, Franco Iafrate, Gioacchino Galardo, Francesco Pugliese, Valeria Panebianco, Paolo Ricci, Carlo Catalano, Maria Rosa Ciardi, Grazia Maria Liuzzi and Claudio Maria Mastroianni
Biomolecules 2023, 13(7), 1040; https://doi.org/10.3390/biom13071040 - 26 Jun 2023
Cited by 4 | Viewed by 1568
Abstract
Background: The aim of the study was to longitudinally evaluate the association between MMP-2, MMP-9, TIMP-1 and chest radiological findings in COVID-19 patients. Methods: COVID-19 patients were evaluated based on their hospital admission (baseline) and three months after hospital discharge (T post) and [...] Read more.
Background: The aim of the study was to longitudinally evaluate the association between MMP-2, MMP-9, TIMP-1 and chest radiological findings in COVID-19 patients. Methods: COVID-19 patients were evaluated based on their hospital admission (baseline) and three months after hospital discharge (T post) and were stratified into ARDS and non-ARDS groups. As a control group, healthy donors (HD) were enrolled. Results: At the baseline, compared to HD (n = 53), COVID-19 patients (n = 129) showed higher plasma levels of MMP-9 (p < 0.0001) and TIMP-1 (p < 0.0001) and the higher plasma activity of MMP-2 (p < 0.0001) and MMP-9 (p < 0.0001). In the ARDS group, higher plasma levels of MMP-9 (p = 0.0339) and TIMP-1 (p = 0.0044) and the plasma activity of MMP-2 (p = 0.0258) and MMP-9 (p = 0.0021) compared to non-ARDS was observed. A positive correlation between the plasma levels of TIMP-1 and chest computed tomography (CT) score (ρ = 0.2302, p = 0.0160) was observed. At the T post, a reduction in plasma levels of TIMP-1 (p < 0.0001), whereas an increase in the plasma levels of MMP-9 was observed (p = 0.0088). Conclusions: The positive correlation between TIMP-1 with chest CT scores highlights its potential use as a marker of fibrotic burden. At T post, the increase in plasma levels of MMP-9 and the reduction in plasma levels of TIMP-1 suggested that inflammation and fibrosis resolution were still ongoing. Full article
(This article belongs to the Special Issue Matrix Metalloproteinases in Health and Disease 3.0)
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16 pages, 2707 KiB  
Article
Enzymatic Modification of Pomace Olive Oil with Natural Antioxidants: Effect on Oxidative Stability
by Renia Fotiadou, Dimitrios Lefas, Despina Vougiouklaki, Aliki Tsakni, Dimitra Houhoula and Haralambos Stamatis
Biomolecules 2023, 13(7), 1034; https://doi.org/10.3390/biom13071034 - 23 Jun 2023
Cited by 4 | Viewed by 1379
Abstract
Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive [...] Read more.
Enzymatic lipophilization has been proposed as a cost-effective strategy to produce new liposoluble antioxidant compounds. In this study, modified oils rich in structured phenolipids were prepared via one-pot enzymatic acylation of hydroxytyrosol (HTYR), vanillyl alcohol (VA) and homovanillyl alcohol (HVA) with pomace olive oil (POO) in solvent-free conditions using immobilized lipase on biogenic nanoparticles. The effect of temperature (30–70 °C) and enzyme concentration (0.1–1%, w/w) on the efficiency of the bioprocess as well as the reusability of the nanobiocatalyst were thoroughly investigated. The modified oils exhibited increased antioxidant activity compared to the control oil according to DPPH and CUPRAC assays (p < 0.05). The oxidative stability of pomace olive oil was also significantly enhanced after modification, as depicted by the K232 values and TBARS contents under accelerated oxidation at 60 °C (p < 0.05). Moreover, a fortified mayonnaise containing modified oil with HTYR was prepared that was noticeably stable compared to the control mayonnaise at 28 °C for 5 months (p < 0.05). Enzymatically modified oils have great potential for application in the nutraceutical and food industry, encouraging the exploitation of immobilized lipases as effective and green catalytic tools. Full article
(This article belongs to the Topic Antioxidant Activity of Natural Products)
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13 pages, 2921 KiB  
Article
Shapes and Patterns of Heme-Binding Motifs in Mammalian Heme-Binding Proteins
by Dhruv C. Rathod, Sonali M. Vaidya, Marie-T. Hopp, Toni Kühl and Diana Imhof
Biomolecules 2023, 13(7), 1031; https://doi.org/10.3390/biom13071031 - 23 Jun 2023
Cited by 5 | Viewed by 2629
Abstract
Heme is a double-edged sword. On the one hand, it has a pivotal role as a prosthetic group of hemoproteins in many biological processes ranging from oxygen transport and storage to miRNA processing. On the other hand, heme can transiently associate with proteins, [...] Read more.
Heme is a double-edged sword. On the one hand, it has a pivotal role as a prosthetic group of hemoproteins in many biological processes ranging from oxygen transport and storage to miRNA processing. On the other hand, heme can transiently associate with proteins, thereby regulating biochemical pathways. During hemolysis, excess heme, which is released into the plasma, can bind to proteins and regulate their activity and function. The role of heme in these processes is under-investigated, with one problem being the lack of knowledge concerning recognition mechanisms for the initial association of heme with the target protein and the formation of the resulting complex. A specific heme-binding sequence motif is a prerequisite for such complex formation. Although numerous short signature sequences indicating a particular protein function are known, a comprehensive analysis of the heme-binding motifs (HBMs) which have been identified in proteins, concerning specific patterns and structural peculiarities, is missing. In this report, we focus on the evaluation of known mammalian heme-regulated proteins concerning specific recognition and structural patterns in their HBMs. The Cys-Pro dipeptide motifs are particularly emphasized because of their more frequent occurrence. This analysis presents a comparative insight into the sequence and structural anomalies observed during transient heme binding, and consequently, in the regulation of the relevant protein. Full article
(This article belongs to the Special Issue Unraveling Mysteries of Heme Metabolism)
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16 pages, 3866 KiB  
Article
Chemical Composition and Bioactivity of Laboratory-Fermented Bee Pollen in Comparison with Natural Bee Bread
by Michał Miłek, Mateusz Mołoń, Monika Kula-Maximenko, Ewelina Sidor, Grzegorz Zaguła and Małgorzata Dżugan
Biomolecules 2023, 13(7), 1025; https://doi.org/10.3390/biom13071025 - 22 Jun 2023
Cited by 2 | Viewed by 2188
Abstract
Bee bread is a valuable product obtained from the hive on a relatively small scale, while bee pollen is more easily available. Therefore, an effective laboratory method of converting pollen into a bee bread substitute is desired. The aim of the research was [...] Read more.
Bee bread is a valuable product obtained from the hive on a relatively small scale, while bee pollen is more easily available. Therefore, an effective laboratory method of converting pollen into a bee bread substitute is desired. The aim of the research was to verify the influence of selected factors (temperature, ultrasound) on the quality of obtained product using Lactobacillus rhamnosus inoculum. The composition of the fermented pollen was analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Raman spectroscopy, and SDS-PAGE and compared to natural bee bread and the original pollen. In vitro biological activity was assessed as antioxidant activity using a yeast model (BY4741 and sod1∆ strains). Fermentation of pollen occurred spontaneously and after inoculation, as demonstrated by lower pH and higher lactic acid content. Raman spectroscopy and ICP-OES confirmed changes in composition compared to the initial pollen. Compared to bee bread, the fermented pollen showed a higher content of polyphenols and comparable antioxidant activity; moreover, it accelerated yeast growth rate. In addition, a protective effect was observed for Cu/Zn-superoxide dismutase 1 (sod1∆ yeast mutant exposed to hydrogen peroxide-induced oxidative stress). The higher fermentation temperature (25 °C) produces a more bee-bread-like product, while the use of ultrasound and starter culture seems to have no positive effect. Full article
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15 pages, 1888 KiB  
Article
Dynamics of Urinary Extracellular DNA in Urosepsis
by Michaela Mihaľová, Nadja Šupčíková, Alexandra Gaál Kovalčíková, Ján Breza, Jr., Ľubomíra Tóthová, Peter Celec and Ján Breza, Sr.
Biomolecules 2023, 13(6), 1008; https://doi.org/10.3390/biom13061008 - 17 Jun 2023
Cited by 1 | Viewed by 1752
Abstract
Extracellular DNA (ecDNA) is a promising candidate marker for the early diagnosis and monitoring of urinary tract infections (UTIs). The aim of our study is to describe the dynamics of ecDNA in the plasma and urine of patients with urosepsis as well as [...] Read more.
Extracellular DNA (ecDNA) is a promising candidate marker for the early diagnosis and monitoring of urinary tract infections (UTIs). The aim of our study is to describe the dynamics of ecDNA in the plasma and urine of patients with urosepsis as well as in a mouse model of UTI. Samples of blood and urine were collected from adult patients with UTIs and obstructive uropathy (n = 36) during the first 3 days at the hospital and during a follow-up. Bacterial burden and urinary ecDNA were evaluated in a mouse UTI model (n = 26) at baseline; 24, 48, and 72 h after UTI induction; and 7 days after UTI induction. The plasma ecDNA did not change during urosepsis, but the plasma DNase activity increased significantly at the follow-up. The urinary ecDNA decreased significantly during hospitalization and remained low until the follow-up (90% lower vs. admission). No change was seen in the urinary DNase activity. C-reactive protein (CRP) and procalcitonin are positively correlated with plasma and urinary ecDNA. A UTI caused sepsis in 23% of mice. The urinary ecDNA decreased by three-fold and remained low until day 7 post-infection. Urinary bacterial burden is correlated with urinary ecDNA. Urinary ecDNA is a potential non-invasive marker for monitoring the effects of treatment during urosepsis and is related to UTI progression in the experimental animal model. Full article
(This article belongs to the Special Issue Biomarkers in Renal Diseases)
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27 pages, 8490 KiB  
Article
The Ubiquitin-Proteasome System Participates in Sperm Surface Subproteome Remodeling during Boar Sperm Capacitation
by Michal Zigo, Karl Kerns and Peter Sutovsky
Biomolecules 2023, 13(6), 996; https://doi.org/10.3390/biom13060996 - 15 Jun 2023
Cited by 2 | Viewed by 2777
Abstract
Sperm capacitation is a complex process endowing biological and biochemical changes to a spermatozoon for a successful encounter with an oocyte. The present study focused on the role of the ubiquitin–proteasome system (UPS) in the remodeling of the sperm surface subproteome. The sperm [...] Read more.
Sperm capacitation is a complex process endowing biological and biochemical changes to a spermatozoon for a successful encounter with an oocyte. The present study focused on the role of the ubiquitin–proteasome system (UPS) in the remodeling of the sperm surface subproteome. The sperm surface subproteome from non-capacitated and in vitro capacitated (IVC) porcine spermatozoa, with and without proteasomal inhibition, was selectively isolated. The purified sperm surface subproteome was analyzed using high-resolution, quantitative liquid chromatography–mass spectrometry (LC-MS) in four replicates. We identified 1680 HUGO annotated proteins, out of which we found 91 to be at least 1.5× less abundant (p < 0.05) and 141 to be at least 1.5× more abundant (p < 0.05) on the surface of IVC spermatozoa. These proteins were associated with sperm capacitation, hyperactivation, metabolism, acrosomal exocytosis, and fertilization. Abundances of 14 proteins were found to be significantly different (p < 0.05), exceeding a 1.5-fold abundance between the proteasomally inhibited (100 µM MG132) and vehicle control (0.2% ethanol) groups. The proteins NIF3L1, CSE1L, NDUFB7, PGLS, PPP4C, STK39, and TPRG1L were found to be more abundant; while BPHL, GSN, GSPT1, PFDN4, STYXL1, TIMM10, and UBXN4 were found to be less abundant in proteasomally inhibited IVC spermatozoa. Despite the UPS having a narrow range of targets, it modulated sperm metabolism and binding by regulating susceptible surface proteins. Changes in CSE1L, PFDN4, and STK39 during in vitro capacitation were confirmed using immunocytochemistry, image-based flow cytometry, and Western blotting. The results confirmed the active participation of the UPS in the extensive sperm surface proteome remodeling that occurs during boar sperm capacitation. This work will help us to identify new pharmacological mechanisms to positively or negatively modulate sperm fertilizing ability in food animals and humans. Full article
(This article belongs to the Special Issue Gametogenesis and Gamete Interaction)
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19 pages, 3901 KiB  
Article
Unconventional Source of Neurotoxic Protein Aggregation from Organelle Off-Target Bax∆2 in Alzheimer’s Disease
by Qi Yao, Anne Caroline Mascarenhas dos Santos, Huaiyuan Zhang, Adriana Mañas, Ammarah Hussaini, Ujin Kim, Congtai Xu, Sana Basheer, Shinya Tasaki and Jialing Xiang
Biomolecules 2023, 13(6), 970; https://doi.org/10.3390/biom13060970 - 10 Jun 2023
Viewed by 1835
Abstract
Protein aggregates are a hallmark of Alzheimer’s disease (AD). Extensive studies have focused on β-amyloid plaques and Tau tangles. Here, we illustrate a novel source of protein aggregates in AD neurons from organelle off-target proteins. Bax is a mitochondrial pore-forming pro-death protein. What [...] Read more.
Protein aggregates are a hallmark of Alzheimer’s disease (AD). Extensive studies have focused on β-amyloid plaques and Tau tangles. Here, we illustrate a novel source of protein aggregates in AD neurons from organelle off-target proteins. Bax is a mitochondrial pore-forming pro-death protein. What happens to Bax if it fails to target mitochondria? We previously showed that a mitochondrial target-deficient alternatively spliced variant, Bax∆2, formed large cytosolic protein aggregates and triggered caspase 8-mediated cell death. Bax∆2 protein levels were low in most normal organs and the proteins were quickly degraded in cancer. Here, we found that 85% of AD patients had Bax∆2 required alternative splicing. Increased Bax∆2 proteins were mostly accumulated in neurons of AD-susceptible brain regions. Intracellularly, Bax∆2 aggregates distributed independently of Tau tangles. Interestingly, Bax∆2 aggregates triggered the formation of stress granules (SGs), a large protein-RNA complex involved in AD pathogenesis. Although the functional domains required for aggregation and cell death are the same as in cancer cells, Bax∆2 relied on SGs, not caspase 8, for neuronal cell death. These results imply that the aggregation of organelle off-target proteins, such as Bax∆2, broadens the scope of traditional AD pathogenic proteins that contribute to the neuronal stress responses and AD pathogenesis. Full article
(This article belongs to the Special Issue Advances in Brain Development and Disease)
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13 pages, 1469 KiB  
Article
Anti-TNF Biologicals Enhance the Anti-Inflammatory Properties of IgG N-Glycome in Crohn’s Disease
by Maja Hanić, Frano Vučković, Helena Deriš, Claire Bewshea, Simeng Lin, James R. Goodhand, Tariq Ahmad, Irena Trbojević-Akmačić, Nicholas A. Kennedy, Gordan Lauc and PANTS Consortium
Biomolecules 2023, 13(6), 954; https://doi.org/10.3390/biom13060954 - 7 Jun 2023
Cited by 3 | Viewed by 1709
Abstract
Crohn’s disease (CD) is a chronic inflammation of the digestive tract that significantly impairs patients’ quality of life and well-being. Anti-TNF biologicals revolutionised the treatment of CD, yet many patients do not adequately respond to such therapy. Previous studies have demonstrated a pro-inflammatory [...] Read more.
Crohn’s disease (CD) is a chronic inflammation of the digestive tract that significantly impairs patients’ quality of life and well-being. Anti-TNF biologicals revolutionised the treatment of CD, yet many patients do not adequately respond to such therapy. Previous studies have demonstrated a pro-inflammatory pattern in the composition of CD patients’ immunoglobulin G (IgG) N-glycome compared to healthy individuals. Here, we utilised the high-throughput UHPLC method for N-glycan analysis to explore the longitudinal effect of the anti-TNF drugs infliximab and adalimumab on N-glycome composition of total serum IgG in 198 patients, as well as the predictive potential of IgG N-glycans at baseline to detect primary non-responders to anti-TNF therapy in 1315 patients. We discovered a significant decrease in IgG agalactosylation and an increase in monogalactosylation, digalactosylation and sialylation during the 14 weeks of anti-TNF treatment, regardless of therapy response, all of which suggested a diminished inflammatory environment in CD patients treated with anti-TNF therapy. Furthermore, we observed that IgG N-glycome might contain certain information regarding the anti-TNF therapy outcome before initiating the treatment. However, it is impossible to predict future primary non-responders to anti-TNF therapy based solely on IgG N-glycome composition at baseline. Full article
(This article belongs to the Collection Metabolomics and Integrated Multi-Omics in Health and Disease)
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20 pages, 2711 KiB  
Article
Administration of Warfarin Inhibits the Development of Cerulein-Induced Edematous Acute Pancreatitis in Rats
by Katarzyna Konarska-Bajda, Piotr Ceranowicz, Jakub Cieszkowski, Grzegorz Ginter, Agnieszka Stempniewicz, Krystyna Gałązka, Beata Kuśnierz-Cabala, Paulina Dumnicka, Joanna Bonior and Zygmunt Warzecha
Biomolecules 2023, 13(6), 948; https://doi.org/10.3390/biom13060948 - 6 Jun 2023
Cited by 3 | Viewed by 1758
Abstract
Acute pancreatitis (AP) is a severe disease with high morbidity and mortality in which inflammation and coagulation play crucial roles. The development of inflammation leads to vascular injury, endothelium and leukocytes stimulation, and an increased level of tissue factor, which results in the [...] Read more.
Acute pancreatitis (AP) is a severe disease with high morbidity and mortality in which inflammation and coagulation play crucial roles. The development of inflammation leads to vascular injury, endothelium and leukocytes stimulation, and an increased level of tissue factor, which results in the activation of the coagulation process. For this reason, anticoagulants may be considered as a therapeutic option in AP. Previous studies have shown that pretreatment with heparin, low-molecular-weight heparin (LMWH), or acenocoumarol inhibits the development of AP. The aim of the present study was to check if pretreatment with warfarin affects the development of edematous pancreatitis evoked by cerulein. Warfarin (90, 180, or 270 µg/kg/dose) or saline were administered intragastrically once a day for 7 days consecutively before the induction of AP. AP was evoked by the intraperitoneal administration of cerulein. The pre-administration of warfarin at doses of 90 or 180 µg/kg/dose reduced the histological signs of pancreatic damage in animals with the induction of AP. Additionally, other parameters of AP, such as an increase in the serum activity of lipase and amylase, the plasma concentration of D-dimer, and interleukin-1β, were decreased. In addition, pretreatment with warfarin administered at doses of 90 or 180 µg/kg/dose reversed the limitation of pancreatic blood flow evoked by AP development. Warfarin administered at a dose of 270 µg/kg/dose did not exhibit a preventive effect in cerulein-induced AP. Conclusion: Pretreatment with low doses of warfarin inhibits the development of AP evoked by the intraperitoneal administration of cerulein. Full article
(This article belongs to the Special Issue Biomarkers for Pancreatitis and Its Complications)
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13 pages, 3156 KiB  
Article
Ribosomal Protein S12 Hastens Nucleation of Co-Transcriptional Ribosome Assembly
by Margaret L. Rodgers, Yunsheng Sun and Sarah A. Woodson
Biomolecules 2023, 13(6), 951; https://doi.org/10.3390/biom13060951 - 6 Jun 2023
Cited by 1 | Viewed by 1557
Abstract
Ribosomal subunits begin assembly during transcription of the ribosomal RNA (rRNA), when the rRNA begins to fold and associate with ribosomal proteins (RPs). In bacteria, the first steps of ribosome assembly depend upon recognition of the properly folded rRNA by primary assembly proteins [...] Read more.
Ribosomal subunits begin assembly during transcription of the ribosomal RNA (rRNA), when the rRNA begins to fold and associate with ribosomal proteins (RPs). In bacteria, the first steps of ribosome assembly depend upon recognition of the properly folded rRNA by primary assembly proteins such as S4, which nucleates assembly of the 16S 5′ domain. Recent evidence, however, suggests that initial recognition by S4 is delayed due to variable folding of the rRNA during transcription. Here, using single-molecule colocalization co-transcriptional assembly (smCoCoA), we show that the late-binding RP S12 specifically promotes the association of S4 with the pre-16S rRNA during transcription, thereby accelerating nucleation of 30S ribosome assembly. Order of addition experiments suggest that S12 helps chaperone the rRNA during transcription, particularly near the S4 binding site. S12 interacts transiently with the rRNA during transcription and, consequently, a high concentration is required for its chaperone activity. These results support a model in which late-binding RPs moonlight as RNA chaperones during transcription in order to facilitate rapid assembly. Full article
(This article belongs to the Special Issue Ribosomal Proteins in Ribosome Assembly)
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17 pages, 9304 KiB  
Article
Quantifying Yeast Microtubules and Spindles Using the Toolkit for Automated Microtubule Tracking (TAMiT)
by Saad Ansari, Zachary R. Gergely, Patrick Flynn, Gabriella Li, Jeffrey K. Moore and Meredith D. Betterton
Biomolecules 2023, 13(6), 939; https://doi.org/10.3390/biom13060939 - 4 Jun 2023
Cited by 1 | Viewed by 1411
Abstract
Fluorescently labeled proteins absorb and emit light, appearing as Gaussian spots in fluorescence imaging. When fluorescent tags are added to cytoskeletal polymers such as microtubules, a line of fluorescence and even non-linear structures results. While much progress has been made in techniques for [...] Read more.
Fluorescently labeled proteins absorb and emit light, appearing as Gaussian spots in fluorescence imaging. When fluorescent tags are added to cytoskeletal polymers such as microtubules, a line of fluorescence and even non-linear structures results. While much progress has been made in techniques for imaging and microscopy, image analysis is less well-developed. Current analysis of fluorescent microtubules uses either manual tools, such as kymographs, or automated software. As a result, our ability to quantify microtubule dynamics and organization from light microscopy remains limited. Despite the development of automated microtubule analysis tools for in vitro studies, analysis of images from cells often depends heavily on manual analysis. One of the main reasons for this disparity is the low signal-to-noise ratio in cells, where background fluorescence is typically higher than in reconstituted systems. Here, we present the Toolkit for Automated Microtubule Tracking (TAMiT), which automatically detects, optimizes, and tracks fluorescent microtubules in living yeast cells with sub-pixel accuracy. Using basic information about microtubule organization, TAMiT detects linear and curved polymers using a geometrical scanning technique. Images are fit via an optimization problem for the microtubule image parameters that are solved using non-linear least squares in Matlab. We benchmark our software using simulated images and show that it reliably detects microtubules, even at low signal-to-noise ratios. Then, we use TAMiT to measure monopolar spindle microtubule bundle number, length, and lifetime in a large dataset that includes several S. pombe mutants that affect microtubule dynamics and bundling. The results from the automated analysis are consistent with previous work and suggest a direct role for CLASP/Cls1 in bundling spindle microtubules. We also illustrate automated tracking of single curved astral microtubules in S. cerevisiae, with measurement of dynamic instability parameters. The results obtained with our fully-automated software are similar to results using hand-tracked measurements. Therefore, TAMiT can facilitate automated analysis of spindle and microtubule dynamics in yeast cells. Full article
(This article belongs to the Special Issue Molecular Functions of Microtubules)
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20 pages, 7260 KiB  
Article
Cyclosporines Antagonize the Antiviral Activity of IFITMProteins by Redistributing Them toward the Golgi Apparatus
by David Prikryl, Mariana Marin, Tanay M. Desai, Yuhong Du, Haian Fu and Gregory B. Melikyan
Biomolecules 2023, 13(6), 937; https://doi.org/10.3390/biom13060937 - 3 Jun 2023
Cited by 1 | Viewed by 2006
Abstract
Interferon-induced transmembrane proteins (IFITMs) block the fusion of diverse enveloped viruses, likely through increasing the cell membrane’s rigidity. Previous studies have reported that the antiviral activity of the IFITM family member, IFITM3, is antagonized by cell pretreatment with rapamycin derivatives and cyclosporines A [...] Read more.
Interferon-induced transmembrane proteins (IFITMs) block the fusion of diverse enveloped viruses, likely through increasing the cell membrane’s rigidity. Previous studies have reported that the antiviral activity of the IFITM family member, IFITM3, is antagonized by cell pretreatment with rapamycin derivatives and cyclosporines A and H (CsA and CsH) that promote the degradation of IFITM3. Here, we show that CsA and CsH potently enhance virus fusion with IFITM1- and IFITM3-expressing cells by inducing their rapid relocalization from the plasma membrane and endosomes, respectively, towards the Golgi. This relocalization is not associated with a significant degradation of IFITMs. Although prolonged exposure to CsA induces IFITM3 degradation in cells expressing low endogenous levels of this protein, its levels remain largely unchanged in interferon-treated cells or cells ectopically expressing IFITM3. Importantly, the CsA-mediated redistribution of IFITMs to the Golgi occurs on a much shorter time scale than degradation and thus likely represents the primary mechanism of enhancement of virus entry. We further show that rapamycin also induces IFITM relocalization toward the Golgi, albeit less efficiently than cyclosporines. Our findings highlight the importance of regulation of IFITM trafficking for its antiviral activity and reveal a novel mechanism of the cyclosporine-mediated modulation of cell susceptibility to enveloped virus infection. Full article
(This article belongs to the Special Issue Molecular Mechanism Investigations into Membrane Fusion)
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16 pages, 896 KiB  
Article
Hyperactivity in Mice Induced by Opioid Agonists with Partial Intrinsic Efficacy and Biased Agonism Administered Alone and in Combination with Morphine
by Agnes Acevedo-Canabal, Travis W. Grim, Cullen L. Schmid, Nina McFague, Edward L. Stahl, Nicole M. Kennedy, Thomas D. Bannister and Laura M. Bohn
Biomolecules 2023, 13(6), 935; https://doi.org/10.3390/biom13060935 - 2 Jun 2023
Cited by 2 | Viewed by 2441
Abstract
Opioid analgesics such as morphine and fentanyl induce mu-opioid receptor (MOR)-mediated hyperactivity in mice. Herein, we show that morphine, fentanyl, SR-17018, and oliceridine have submaximal intrinsic efficacy in the mouse striatum using 35S-GTPγS binding assays. While all of the agonists act as [...] Read more.
Opioid analgesics such as morphine and fentanyl induce mu-opioid receptor (MOR)-mediated hyperactivity in mice. Herein, we show that morphine, fentanyl, SR-17018, and oliceridine have submaximal intrinsic efficacy in the mouse striatum using 35S-GTPγS binding assays. While all of the agonists act as partial agonists for stimulating G protein coupling in striatum, morphine, fentanyl, and oliceridine are fully efficacious in stimulating locomotor activity; meanwhile, the noncompetitive biased agonists SR-17018 and SR-15099 produce submaximal hyperactivity. Moreover, the combination of SR-17018 and morphine attenuates hyperactivity while antinociceptive efficacy is increased. The combination of oliceridine with morphine increases hyperactivity, which is maintained over time. These findings provide evidence that noncompetitive agonists at MOR can be used to suppress morphine-induced hyperactivity while enhancing antinociceptive efficacy; moreover, they demonstrate that intrinsic efficacy measured at the receptor level is not directly proportional to drug efficacy in the locomotor activity assay. Full article
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19 pages, 4790 KiB  
Article
Disease-Specific α-Synuclein Seeding in Lewy Body Disease and Multiple System Atrophy Are Preserved in Formaldehyde-Fixed Paraffin-Embedded Human Brain
by Ain Kim, Ivan Martinez-Valbuena, Jun Li, Anthony E. Lang and Gabor G. Kovacs
Biomolecules 2023, 13(6), 936; https://doi.org/10.3390/biom13060936 - 2 Jun 2023
Cited by 2 | Viewed by 2486
Abstract
Recent studies have been able to detect α-synuclein (αSyn) seeding in formaldehyde-fixed paraffin-embedded (FFPE) tissues from patients with synucleinopathies using seed amplification assays (SAAs), but with relatively low sensitivity due to limited protein extraction efficiency. With the aim of introducing an alternative option [...] Read more.
Recent studies have been able to detect α-synuclein (αSyn) seeding in formaldehyde-fixed paraffin-embedded (FFPE) tissues from patients with synucleinopathies using seed amplification assays (SAAs), but with relatively low sensitivity due to limited protein extraction efficiency. With the aim of introducing an alternative option to frozen tissues, we developed a streamlined protein extraction protocol for evaluating disease-specific seeding in FFPE human brain. We evaluated the protein extraction efficiency of different tissue preparations, deparaffinizations, and protein extraction buffers using formaldehyde-fixed and FFPE tissue of a single Lewy body disease (LBD) subject. Alternatively, we incorporated heat-induced antigen retrieval and dissociation using a commercially available kit. Our novel protein extraction protocol has been optimized to work with 10 sections of 4.5-µm-thickness or 2-mm-diameter micro-punch of FFPE tissue that can be used to seed SAAs. We demonstrated that extracted proteins from FFPE still preserve seeding potential and further show disease-specific seeding in LBD and multiple system atrophy. To the best of our knowledge, our study is the first to recapitulate disease-specific αSyn seeding behaviour in FFPE human brain. Our findings open new perspectives in re-evaluating archived human brain tissue, extending the disease-specific seeding assays to larger cohorts to facilitate molecular subtyping of synucleinopathies. Full article
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26 pages, 2667 KiB  
Article
Protein Biomarker Discovery Studies on Urinary sEV Fractions Separated with UF-SEC for the First Diagnosis and Detection of Recurrence in Bladder Cancer Patients
by Stephanie Jordaens, Eline Oeyen, Hanny Willems, Filip Ameye, Stefan De Wachter, Patrick Pauwels and Inge Mertens
Biomolecules 2023, 13(6), 932; https://doi.org/10.3390/biom13060932 - 1 Jun 2023
Cited by 5 | Viewed by 2087
Abstract
Urinary extracellular vesicles (EVs) are an attractive source of bladder cancer biomarkers. Here, a protein biomarker discovery study was performed on the protein content of small urinary EVs (sEVs) to identify possible biomarkers for the primary diagnosis and recurrence of non-muscle-invasive bladder cancer [...] Read more.
Urinary extracellular vesicles (EVs) are an attractive source of bladder cancer biomarkers. Here, a protein biomarker discovery study was performed on the protein content of small urinary EVs (sEVs) to identify possible biomarkers for the primary diagnosis and recurrence of non-muscle-invasive bladder cancer (NMIBC). The sEVs were isolated by ultrafiltration (UF) in combination with size-exclusion chromatography (SEC). The first part of the study compared healthy individuals with NMIBC patients with a primary diagnosis. The second part compared tumor-free patients with patients with a recurrent NMIBC diagnosis. The separated sEVs were in the size range of 40 to 200 nm. Based on manually curated high quality mass spectrometry (MS) data, the statistical analysis revealed 69 proteins that were differentially expressed in these sEV fractions of patients with a first bladder cancer tumor vs. an age- and gender-matched healthy control group. When the discriminating power between healthy individuals and first diagnosis patients is taken into account, the biomarkers with the most potential are MASP2, C3, A2M, CHMP2A and NHE-RF1. Additionally, two proteins (HBB and HBA1) were differentially expressed between bladder cancer patients with a recurrent diagnosis vs. tumor-free samples of bladder cancer patients, but their biological relevance is very limited. Full article
(This article belongs to the Special Issue The Next Generation of Proteomics for Precision Medicine)
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20 pages, 4362 KiB  
Article
Mucoadhesive Rifampicin-Liposomes for the Treatment of Pulmonary Infection by Mycobacterium abscessus: Chitosan or ε-Poly-L-Lysine Decoration
by Jacopo Forte, Patrizia Nadia Hanieh, Noemi Poerio, Tommaso Olimpieri, Maria Grazia Ammendolia, Maurizio Fraziano, Maria Gioia Fabiano, Carlotta Marianecci, Maria Carafa, Federico Bordi, Simona Sennato and Federica Rinaldi
Biomolecules 2023, 13(6), 924; https://doi.org/10.3390/biom13060924 - 31 May 2023
Cited by 3 | Viewed by 1766
Abstract
Mycobacterium abscessus (Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy [...] Read more.
Mycobacterium abscessus (Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy against pulmonary Mabs infection, due to the possibility to be aerosolically administrated and to tune their properties in order to increase nebulization resistance and retainment of encapsulated drug. In fact, liposome surface can be modified by decoration with mucoadhesive polymers to enhance its stability, mucus penetration and prolong its residence time in the lung. The aim of this work is to employ Chitosan or ε-poly-L-lysine decoration for improving the properties of a novel liposomes composed by hydrogenated phosphatidyl-choline from soybean (HSPC) and anionic 1,2-Dipalmitoyl-sn-glycero-3-phosphorylglycerol sodium salt (DPPG) able to entrap Rifampicin. A deep physicochemical characterization of polymer-decorated liposomes shows that both polymers improve mucoadhesion without affecting liposome features and Rifampicin entrapment efficiency. Therapeutic activity on Mabs-infected macrophages demonstrates an effective antibacterial effect of ε-poly-L-lysine liposomes with respect to chitosan-decorated ones. Altogether, these results suggest a possible use of ε-PLL liposomes to improve antibiotic delivery in the lung. Full article
(This article belongs to the Special Issue Liposomes for Drug Delivery: Recent Advances and Discoveries)
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16 pages, 13956 KiB  
Article
xProtCAS: A Toolkit for Extracting Conserved Accessible Surfaces from Protein Structures
by Hazem M. Kotb and Norman E. Davey
Biomolecules 2023, 13(6), 906; https://doi.org/10.3390/biom13060906 - 30 May 2023
Viewed by 3599
Abstract
The identification of protein surfaces required for interaction with other biomolecules broadens our understanding of protein function, their regulation by post-translational modification, and the deleterious effect of disease mutations. Protein interaction interfaces are often identifiable as patches of conserved residues on a protein’s [...] Read more.
The identification of protein surfaces required for interaction with other biomolecules broadens our understanding of protein function, their regulation by post-translational modification, and the deleterious effect of disease mutations. Protein interaction interfaces are often identifiable as patches of conserved residues on a protein’s surface. However, finding conserved accessible surfaces on folded regions requires an understanding of the protein structure to discriminate between functional and structural constraints on residue conservation. With the emergence of deep learning methods for protein structure prediction, high-quality structural models are now available for any protein. In this study, we introduce tools to identify conserved surfaces on AlphaFold2 structural models. We define autonomous structural modules from the structural models and convert these modules to a graph encoding residue topology, accessibility, and conservation. Conserved surfaces are then extracted using a novel eigenvector centrality-based approach. We apply the tool to the human proteome identifying hundreds of uncharacterised yet highly conserved surfaces, many of which contain clinically significant mutations. The xProtCAS tool is available as open-source Python software and an interactive web server. Full article
(This article belongs to the Special Issue Bioinformatics in Protein Evolution)
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14 pages, 2074 KiB  
Article
Pharmacological Characterization of P626, a Novel Dual Adenosine A2A/A2B Receptor Antagonist, on Synaptic Plasticity and during an Ischemic-like Insult in CA1 Rat Hippocampus
by Martina Venturini, Federica Cherchi, Clara Santalmasi, Lucia Frulloni, Ilaria Dettori, Daniela Catarzi, Felicita Pedata, Vittoria Colotta, Flavia Varano, Elisabetta Coppi and Anna Maria Pugliese
Biomolecules 2023, 13(6), 894; https://doi.org/10.3390/biom13060894 - 27 May 2023
Viewed by 1866
Abstract
In recent years, the use of multi-target compounds has become an increasingly pursued strategy to treat complex pathologies, including cerebral ischemia. Adenosine and its receptors (A1AR, A2AAR, A2BAR, A3AR) are known to play a crucial [...] Read more.
In recent years, the use of multi-target compounds has become an increasingly pursued strategy to treat complex pathologies, including cerebral ischemia. Adenosine and its receptors (A1AR, A2AAR, A2BAR, A3AR) are known to play a crucial role in synaptic transmission either in normoxic or ischemic-like conditions. Previous data demonstrate that the selective antagonism of A2AAR or A2BAR delays anoxic depolarization (AD) appearance, an unequivocal sign of neuronal injury induced by a severe oxygen-glucose deprivation (OGD) insult in the hippocampus. Furthermore, the stimulation of A2AARs or A2BARs by respective selective agonists, CGS21680 and BAY60-6583, increases pre-synaptic neurotransmitter release, as shown by the decrease in paired-pulse facilitation (PPF) at Schaffer collateral-CA1 synapses. In the present research, we investigated the effect/s of the newly synthesized dual A2AAR/A2BAR antagonist, P626, in preventing A2AAR- and/or A2BAR-mediated effects by extracellular recordings of synaptic potentials in the CA1 rat hippocampal slices. We demonstrated that P626 prevented PPF reduction induced by CGS21680 or BAY60-6583 and delayed, in a concentration-dependent manner, AD appearance during a severe OGD. In conclusion, P626 may represent a putative neuroprotective compound for stroke treatment with the possible translational advantage of reducing side effects and bypassing differences in pharmacokinetics due to combined treatment. Full article
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18 pages, 2907 KiB  
Article
Serum N-Glycosylation RPLC-FD-MS Assay to Assess Colorectal Cancer Surgical Interventions
by Alan B. Moran, Georgia Elgood-Hunt, Yuri E. M. van der Burgt, Manfred Wuhrer, Wilma E. Mesker, Rob A. E. M. Tollenaar, Daniel I. R. Spencer and Guinevere S. M. Lageveen-Kammeijer
Biomolecules 2023, 13(6), 896; https://doi.org/10.3390/biom13060896 - 27 May 2023
Cited by 1 | Viewed by 2394
Abstract
A newly developed analytical strategy was applied to profile the total serum N-glycome of 64 colorectal cancer (CRC) patients before and after surgical intervention. In this cohort, it was previously found that serum N-glycome alterations in CRC were associated with patient [...] Read more.
A newly developed analytical strategy was applied to profile the total serum N-glycome of 64 colorectal cancer (CRC) patients before and after surgical intervention. In this cohort, it was previously found that serum N-glycome alterations in CRC were associated with patient survival. Here, fluorescent labeling of serum N-glycans was applied using procainamide and followed by sialic acid derivatization specific for α2,6- and α2,3-linkage types via ethyl esterification and amidation, respectively. This strategy allowed efficient separation of specific positional isomers on reversed-phase liquid chromatography–fluorescence detection–mass spectrometry (RPLC-FD-MS) and complemented the previous glycomics data based on matrix-assisted laser desorption/ionization (MALDI)-MS that did not include such separations. The results from comparing pre-operative CRC to post-operative samples were in agreement with studies that identified a decrease in di-antennary structures with core fucosylation and an increase in sialylated tri- and tetra-antennary N-glycans in CRC patient sera. Pre-operative abundances of N-glycans showed good performance for the classification of adenocarcinoma and led to the revisit of the previous MALDI-MS dataset with regard to histological and clinical data. This strategy has the potential to monitor patient profiles before, during, and after clinical events such as treatment, therapy, or surgery and should also be further explored. Full article
(This article belongs to the Special Issue Protein Glycosylation and Human Diseases)
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18 pages, 3951 KiB  
Article
Circulating Hsp70 Levels and the Immunophenotype of Peripheral Blood Lymphocytes as Potential Biomarkers for Advanced Lung Cancer and Therapy Failure after Surgery
by Seyer Safi, Luis Messner, Merten Kliebisch, Linn Eggert, Ceyra Ceylangil, Philipp Lennartz, Benedict Jefferies, Henriette Klein, Moritz Schirren, Michael Dommasch, Dominik Lobinger and Gabriele Multhoff
Biomolecules 2023, 13(5), 874; https://doi.org/10.3390/biom13050874 - 22 May 2023
Cited by 3 | Viewed by 1738
Abstract
Lung cancer remains a devastating disease with a poor clinical outcome. A biomarker signature which could distinguish lung cancer from metastatic disease and detect therapeutic failure would significantly improve patient management and allow for individualized, risk-adjusted therapeutic decisions. In this study, circulating Hsp70 [...] Read more.
Lung cancer remains a devastating disease with a poor clinical outcome. A biomarker signature which could distinguish lung cancer from metastatic disease and detect therapeutic failure would significantly improve patient management and allow for individualized, risk-adjusted therapeutic decisions. In this study, circulating Hsp70 levels were measured using ELISA, and the immunophenotype of the peripheral blood lymphocytes were measured using multiparameter flow cytometry, to identify a predictive biomarker signature for lung cancer patients pre- and post-operatively, in patients with lung metastases and in patients with COPD as an inflammatory lung disease. The lowest Hsp70 concentrations were found in the healthy controls followed by the patients with advanced COPD. Hsp70 levels sequentially increased with an advancing tumor stage and metastatic disease. In the early-recurrence patients, Hsp70 levels started to increase within the first three months after surgery, but remained unaltered in the recurrence-free patients. An early recurrence was associated with a significant drop in B cells and an increase in Tregs, whereas the recurrence-free patients had elevated T and NK cell levels. We conclude that circulating Hsp70 concentrations might have the potential to distinguish lung cancer from metastatic disease, and might be able to predict an advanced tumor stage and early recurrence in lung cancer patients. Further studies with larger patient cohorts and longer follow-up periods are needed to validate Hsp70 and immunophenotypic profiles as predictive biomarker signatures. Full article
(This article belongs to the Special Issue HSP70: From Signaling Mechanisms to Therapeutics)
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17 pages, 5746 KiB  
Article
The IP6K Inhibitor LI-2242 Ameliorates Diet-Induced Obesity, Hyperglycemia, and Hepatic Steatosis in Mice by Improving Cell Metabolism and Insulin Signaling
by Sandip Mukherjee, Molee Chakraborty, Jake Haubner, Glen Ernst, Michael DePasquale, Danielle Carpenter, James C. Barrow and Anutosh Chakraborty
Biomolecules 2023, 13(5), 868; https://doi.org/10.3390/biom13050868 - 20 May 2023
Cited by 4 | Viewed by 2192
Abstract
Obesity and nonalcoholic fatty liver disease (NAFLD) are global health concerns, and thus, drugs for the long-term treatment of these diseases are urgently needed. We previously discovered that the inositol pyrophosphate biosynthetic enzyme IP6K1 is a target in diet-induced obesity (DIO), insulin resistance, [...] Read more.
Obesity and nonalcoholic fatty liver disease (NAFLD) are global health concerns, and thus, drugs for the long-term treatment of these diseases are urgently needed. We previously discovered that the inositol pyrophosphate biosynthetic enzyme IP6K1 is a target in diet-induced obesity (DIO), insulin resistance, and NAFLD. Moreover, high-throughput screening (HTS) assays and structure−activity relationship (SAR) studies identified LI-2242 as a potent IP6K inhibitor compound. Here, we tested the efficacy of LI-2242 in DIO WT C57/BL6J mice. LI-2242 (20 mg/kg/BW daily, i.p.) reduced body weight in DIO mice by specifically reducing the accumulation of body fat. It also improved glycemic parameters and reduced hyperinsulinemia. LI-2242-treated mice displayed reduced the weight of various adipose tissue depots and an increased expression of metabolism- and mitochondrial-energy-oxidation-inducing genes in these tissues. LI-2242 also ameliorated hepatic steatosis by reducing the expression of genes that enhance lipid uptake, lipid stabilization, and lipogenesis. Furthermore, LI-2242 enhances the mitochondrial oxygen consumption rate (OCR) and insulin signaling in adipocytes and hepatocytes in vitro. In conclusion, the pharmacologic inhibition of the inositol pyrophosphate pathway by LI-2242 has therapeutic potential in obesity and NAFLD. Full article
(This article belongs to the Special Issue Inositol Phosphates in Health and Disease)
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19 pages, 3251 KiB  
Article
Enhanced L-β-Aminoisobutyric Acid Is Involved in the Pathophysiology of Effectiveness for Treatment-Resistant Schizophrenia and Adverse Reactions of Clozapine
by Kouji Fukuyama, Eishi Motomura and Motohiro Okada
Biomolecules 2023, 13(5), 862; https://doi.org/10.3390/biom13050862 - 19 May 2023
Cited by 2 | Viewed by 1885
Abstract
Clozapine is an effective antipsychotic for the treatment of antipsychotic-resistant schizophrenia; however, specific types of A/B adverse effects and clozapine-discontinuation syndromes are also well known. To date, both the critical mechanisms of clinical actions (effective for antipsychotic-resistant schizophrenia) and the adverse effects of [...] Read more.
Clozapine is an effective antipsychotic for the treatment of antipsychotic-resistant schizophrenia; however, specific types of A/B adverse effects and clozapine-discontinuation syndromes are also well known. To date, both the critical mechanisms of clinical actions (effective for antipsychotic-resistant schizophrenia) and the adverse effects of clozapine remain to be elucidated. Recently, we demonstrated that clozapine increased the synthesis of L-β-aminoisobutyric acid (L-BAIBA) in the hypothalamus. L-BAIBA is an activator of the adenosine monophosphate-activated protein kinase (AMPK), glycine receptor, GABAA receptor, and GABAB receptor (GABAB-R). These targets of L-BAIBA overlap as potential targets other than the monoamine receptors of clozapine. However, the direct binding of clozapine to these aminoacidic transmitter/modulator receptors remains to be clarified. Therefore, to explore the contribution of increased L-BAIBA on the clinical action of clozapine, this study determined the effects of clozapine and L-BAIBA on tripartite synaptic transmission, including GABAB-R and the group-III metabotropic glutamate receptor (III-mGluR) using cultured astrocytes, as well as on the thalamocortical hyper-glutamatergic transmission induced by impaired glutamate/NMDA receptors using microdialysis. Clozapine increased astroglial L-BAIBA synthesis in time/concentration-dependent manners. Increased L-BAIBA synthesis was observed until 3 days after clozapine discontinuation. Clozapine did not directly bind III-mGluR or GABAB-R, whereas L-BAIBA activated these receptors in the astrocytes. Local administration of MK801 into the reticular thalamic nucleus (RTN) increased L-glutamate release in the medial frontal cortex (mPFC) (MK801-evoked L-glutamate release). Local administration of L-BAIBA into the mPFC suppressed MK801-evoked L-glutamate release. These actions of L-BAIBA were inhibited by antagonists of III-mGluR and GABAB-R, similar to clozapine. These in vitro and in vivo analyses suggest that increased frontal L-BAIBA signaling likely plays an important role in the pharmacological actions of clozapine, such as improving the effectiveness of treating treatment-resistant schizophrenia and several clozapine discontinuation syndromes via the activation of III-mGluR and GABAB-R in the mPFC. Full article
(This article belongs to the Special Issue Glutamate and Glutamate Receptors in Health and Diseases)
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12 pages, 1454 KiB  
Article
Role of the MDR Efflux Pump AcrAB in Epithelial Cell Invasion by Shigella flexneri
by Marco Coluccia, Aude Béranger, Rita Trirocco, Giulia Fanelli, Francesco Zanzi, Bianca Colonna, Milena Grossi, Gianni Prosseda and Martina Pasqua
Biomolecules 2023, 13(5), 823; https://doi.org/10.3390/biom13050823 - 11 May 2023
Cited by 3 | Viewed by 1986
Abstract
The tripartite complex AcrAB-TolC is the major RND pump in Escherichia coli and other Enterobacteriaceae, including Shigella, the etiological agent of bacillary dysentery. In addition to conferring resistance to many classes of antibiotics, AcrAB plays a role in the pathogenesis and virulence [...] Read more.
The tripartite complex AcrAB-TolC is the major RND pump in Escherichia coli and other Enterobacteriaceae, including Shigella, the etiological agent of bacillary dysentery. In addition to conferring resistance to many classes of antibiotics, AcrAB plays a role in the pathogenesis and virulence of several bacterial pathogens. Here, we report data demonstrating that AcrAB specifically contributes to Shigella flexneri invasion of epithelial cells. We found that deletion of both acrA and acrB genes causes reduced survival of S. flexneri M90T strain within Caco-2 epithelial cells and prevents cell-to-cell spread of the bacteria. Infections with single deletion mutant strains indicate that both AcrA and AcrB favor the viability of the intracellular bacteria. Finally, we were able to further confirm the requirement of the AcrB transporter activity for intraepithelial survival by using a specific EP inhibitor. Overall, the data from the present study expand the role of the AcrAB pump to an important human pathogen, such as Shigella, and add insights into the mechanism governing the Shigella infection process. Full article
(This article belongs to the Special Issue Theme Issue Honoring Scientist Louis Pasteur on His 200th Birthday)
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19 pages, 4128 KiB  
Article
Evolution of the Immunoglobulin Isotypes—Variations of Biophysical Properties among Animal Classes
by Nancy D. Pomarici, Roberta Cacciato, Janik Kokot, Monica L. Fernández-Quintero and Klaus R. Liedl
Biomolecules 2023, 13(5), 801; https://doi.org/10.3390/biom13050801 - 8 May 2023
Cited by 2 | Viewed by 2400
Abstract
The adaptive immune system arose around 500 million years ago in jawed fish, and, since then, it has mediated the immune defense against pathogens in all vertebrates. Antibodies play a central role in the immune reaction, recognizing and attacking external invaders. During the [...] Read more.
The adaptive immune system arose around 500 million years ago in jawed fish, and, since then, it has mediated the immune defense against pathogens in all vertebrates. Antibodies play a central role in the immune reaction, recognizing and attacking external invaders. During the evolutionary process, several immunoglobulin isotypes emerged, each having a characteristic structural organization and dedicated function. In this work, we investigate the evolution of the immunoglobulin isotypes, in order to highlight the relevant features that were preserved over time and the parts that, instead, mutated. The residues that are coupled in the evolution process are often involved in intra- or interdomain interactions, meaning that they are fundamental to maintaining the immunoglobulin fold and to ensuring interactions with other domains. The explosive growth of available sequences allows us to point out the evolutionary conserved residues and compare the biophysical properties among different animal classes and isotypes. Our study offers a general overview of the evolution of immunoglobulin isotypes and advances the knowledge of their characteristic biophysical properties, as a first step in guiding protein design from evolution. Full article
(This article belongs to the Section Biomacromolecules: Proteins)
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21 pages, 3287 KiB  
Article
Mice Mutated in the Third Fibronectin Domain of L1 Show Enhanced Hippocampal Neuronal Cell Death, Astrogliosis and Alterations in Behavior
by Ludovica Congiu, Viviana Granato, Igor Jakovcevski, Ralf Kleene, Luciana Fernandes, Sandra Freitag, Matthias Kneussel, Melitta Schachner and Gabriele Loers
Biomolecules 2023, 13(5), 776; https://doi.org/10.3390/biom13050776 - 29 Apr 2023
Cited by 2 | Viewed by 1786
Abstract
Adhesion molecules play major roles in cell proliferation, migration, survival, neurite outgrowth and synapse formation during nervous system development and in adulthood. The neural cell adhesion molecule L1 contributes to these functions during development and in synapse formation and synaptic plasticity after trauma [...] Read more.
Adhesion molecules play major roles in cell proliferation, migration, survival, neurite outgrowth and synapse formation during nervous system development and in adulthood. The neural cell adhesion molecule L1 contributes to these functions during development and in synapse formation and synaptic plasticity after trauma in adulthood. Mutations of L1 in humans result in L1 syndrome, which is associated with mild-to-severe brain malformations and mental disabilities. Furthermore, mutations in the extracellular domain were shown to cause a severe phenotype more often than mutations in the intracellular domain. To explore the outcome of a mutation in the extracellular domain, we generated mice with disruption of the dibasic sequences RK and KR that localize to position 858RKHSKR863 in the third fibronectin type III domain of murine L1. These mice exhibit alterations in exploratory behavior and enhanced marble burying activity. Mutant mice display higher numbers of caspase 3-positive neurons, a reduced number of principle neurons in the hippocampus, and an enhanced number of glial cells. Experiments suggest that disruption of the dibasic sequence in L1 results in subtle impairments in brain structure and functions leading to obsessive-like behavior in males and reduced anxiety in females. Full article
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17 pages, 6737 KiB  
Article
Unexpected Distribution of Chitin and Chitin Synthase across Soft-Bodied Cnidarians
by Lauren E. Vandepas, Michael G. Tassia, Kenneth M. Halanych and Chris T. Amemiya
Biomolecules 2023, 13(5), 777; https://doi.org/10.3390/biom13050777 - 29 Apr 2023
Cited by 3 | Viewed by 2382
Abstract
Cnidarians are commonly recognized as sea jellies, corals, or complex colonies such as the Portuguese man-of-war. While some cnidarians possess rigid internal calcareous skeletons (e.g., corals), many are soft-bodied. Intriguingly, genes coding for the chitin-biosynthetic enzyme, chitin synthase (CHS), were recently identified [...] Read more.
Cnidarians are commonly recognized as sea jellies, corals, or complex colonies such as the Portuguese man-of-war. While some cnidarians possess rigid internal calcareous skeletons (e.g., corals), many are soft-bodied. Intriguingly, genes coding for the chitin-biosynthetic enzyme, chitin synthase (CHS), were recently identified in the model anemone Nematostella vectensis, a species lacking hard structures. Here we report the prevalence and diversity of CHS across Cnidaria and show that cnidarian chitin synthase genes display diverse protein domain organizations. We found that CHS is expressed in cnidarian species and/or developmental stages with no reported chitinous or rigid morphological structures. Chitin affinity histochemistry indicates that chitin is present in soft tissues of some scyphozoan and hydrozoan medusae. To further elucidate the biology of chitin in cnidarian soft tissues, we focused on CHS expression in N. vectensis. Spatial expression data show that three CHS orthologs are differentially expressed in Nematostella embryos and larvae during development, suggesting that chitin has an integral role in the biology of this species. Understanding how a non-bilaterian lineage such as Cnidaria employs chitin may provide new insight into hitherto unknown functions of polysaccharides in animals, as well as their role in the evolution of biological novelty. Full article
(This article belongs to the Collection Feature Papers in Biochemistry)
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13 pages, 1831 KiB  
Article
Glucose Transporter Glut1-Dependent Metabolic Reprogramming Regulates Lipopolysaccharide-Induced Inflammation in RAW264.7 Macrophages
by Alex Cornwell, Hubert Ziółkowski and Alireza Badiei
Biomolecules 2023, 13(5), 770; https://doi.org/10.3390/biom13050770 - 29 Apr 2023
Cited by 4 | Viewed by 2733
Abstract
This study investigated the critical role of Glut1-mediated glucose metabolism in the inflammatory response of macrophages, which are energy-intensive cells within the innate immune system. Inflammation leads to increased Glut1 expression, ensuring sufficient glucose uptake to support macrophage functions. We demonstrated that using [...] Read more.
This study investigated the critical role of Glut1-mediated glucose metabolism in the inflammatory response of macrophages, which are energy-intensive cells within the innate immune system. Inflammation leads to increased Glut1 expression, ensuring sufficient glucose uptake to support macrophage functions. We demonstrated that using siRNA to knock down Glut1 reduces the expression of various pro-inflammatory cytokines and markers, such as IL-6, iNOS, MHC II/CD40, reactive oxygen species, and the hydrogen sulfide (H2S)-producing enzyme cystathionine γ-lyase (CSE). Glut1 activates a pro-inflammatory profile through a nuclear factor (NF)-κB, while silencing Glut1 can prevent lipopolysaccharide (LPS)-induced IκB degradation, blocking NF-κB activation. Glut1’s role in autophagy, an essential process for macrophage functions such as antigen presentation, phagocytosis, and cytokine secretion, was also measured. The findings show that LPS stimulation decreases autophagosome formation, but Glut1 knockdown reverses this effect, increasing autophagy beyond control levels. The study highlights Glut1’s importance in macrophage immune responses and its regulation of apoptosis during LPS stimulation. Knocking down Glut1 negatively impacts cell viability and mitochondrial intrinsic pathway signaling. These findings collectively suggest that targeting macrophage glucose metabolism through Glut1 could potentially serve as a target for controlling inflammation. Full article
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17 pages, 5074 KiB  
Article
Physico-Chemical Changes Induced by Gamma Irradiation on Some Structural Protein Extracts
by Maria Stanca, Carmen Gaidau, Traian Zaharescu, George-Alin Balan, Iulia Matei, Aurica Precupas, Anca Ruxandra Leonties and Gabriela Ionita
Biomolecules 2023, 13(5), 774; https://doi.org/10.3390/biom13050774 - 29 Apr 2023
Cited by 6 | Viewed by 1765
Abstract
In this study, the effect of gamma irradiation (10 kGy) on proteins extracted from animal hide, scales, and wool was evidenced by calorimetric (μDSC) and spectroscopic (IR, circular dichroism, and EPR) methods. Keratin was obtained from sheep wool, collagen and bovine gelatin from [...] Read more.
In this study, the effect of gamma irradiation (10 kGy) on proteins extracted from animal hide, scales, and wool was evidenced by calorimetric (μDSC) and spectroscopic (IR, circular dichroism, and EPR) methods. Keratin was obtained from sheep wool, collagen and bovine gelatin from bovine hide, and fish gelatin from fish scales. The μDSC experiments evidenced that gamma irradiation influences the thermal stability of these proteins differently. The thermal stability of keratin decreases, while a resistance to thermal denaturation was noticed for collagen and gelatins after gamma irradiation. The analysis of the IR spectra demonstrated that gamma irradiation determines changes in the vibrational modes of the amide groups that are associated with protein denaturation, most meaningfully in the case of keratin. As evidenced by circular dichroism for all proteins considered, exposure to gamma radiation produces changes in the secondary structure that are more significant than those produced by UV irradiation. Riboflavin has different effects on the secondary structure of the investigated proteins, a stabilizing effect for keratin and fish gelatin and a destabilizing effect for bovine gelatin, observed in both irradiated and non-irradiated samples. The EPR spectroscopy evidences the presence, in the gamma-irradiated samples, of free radicals centered on oxygen, and the increase in their EPR signals over time due to the presence of riboflavin. Full article
(This article belongs to the Special Issue Biomarkers of Oxidative and Radical Stress)
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