Search Results (2,644)

Short-chain fatty acids (SCFAs) and medium-chain fatty acids (MCFAs) include small organic anions derived from the gut microbiome that interact with organic anion transporters of the SLC22 family, many of which are expressed in the kidney proximal tubule. According to the Remote Sensing and Signaling Theory (RSST), crosstalk between organs (e.g., gut–liver–kidney axis, gut–brain axis) and the gut microbiome is mediated by metabolites and signaling molecules transported by multi-specific “drug” transporters. The renal drug transporter OAT1 (SLC22A6) is also a major transporter of gut-microbiome products and uremic toxins (e.g., indoxyl sulfate); it has been shown to act as part of a regulatory feedback loop involving the gut microbiome. SCFAs, especially propionate and butyrate, have been shown to play a central role in the transcriptional regulation of OAT1 through HDAC inhibition. By fecal metagenomics analyses of Oat1 knockout mice, we now find that propionate synthesis is among the most altered pathways in the gut microbiome. In contrast, these pathways were only minimally altered in the Oat3 (Slc22a8) knockout. Metabolomics analyses indicate that serum propionate derivatives (e.g., propionyl glycine) and 3-hydroxybutyrate are dependent on OAT1 in the knockout mice and in humans treated with probenecid, an OAT1 inhibitor. The gut microbiome of the Oat1 knockout mice also exhibited greater fatty acid synthesis, which generates odd-chain-length fatty acids (e.g. heptanoate) when propionate is available. Overall, the data, especially when considered in light of in vitro experiments of others, indicates the in vivo existence of a feedback loop connecting gut-microbiome-derived SCFAs and MCFAs to kidney proximal tubule uptake via OAT1. This bidirectional feedback loop in turn regulates OAT1 expression through HDAC inhibition. The feedback loop is clearly consistent with the Remote Sensing and Signaling Theory—in particular, the centrality of multi-specific “drug” transporters in organ crosstalk and host–microbiome interactions via small molecules with “high information content.” The key role of OAT1 function in maintaining tubular secretion in CKD supports the importance of this RSST loop in renal pathophysiology. Modulating this RSST loop could have therapeutic value in chronic kidney disease and other contexts. Full article

Background/Objectives: Protozoan parasites of the genus Leishmania are causative agents of a group of devastating human diseases, known as leishmaniasis. These microorganisms possess very unusual mechanisms of gene expression that are poorly understood. This study was aimed at analyzing the tRNA repertoire encoded in the Leishmania infantum genome, a species responsible for the most severe form of disease, visceral leishmaniasis. tRNAs are adaptor molecules aimed at decoding mRNAs into proteins. Results: A total of 92 tRNA genes, dispersed on 38 loci, were identified, often located in regions where unidirectional gene arrays converge. Putative intronic sequences were inferred for three tRNA genes, and, remarkably, nine tRNAs were found to overlap with the protein-coding sequences of annotated genes. According to structural predictions, the L. infantum tRNA repertoire covers 49 out of the 61 possible anticodons, but because of the well-documented wobble phenomenon, these are enough to decode all codons in the 8532 protein-coding genes currently annotated in its genome. As illustrated in this study, codon usage is a well-conserved trait among different Leishmania species but it differs substantially regarding its human host. Finally, we analyzed tRNA adaptation index (tAI) parameters, codon usage metrics, and relative protein expression levels. Conclusions: Apart from providing the tRNA gene repertoire and its genome distribution, we have shown the existence of a statistically significant, positive correlation between the tAI scores and protein expression levels in L. infantum promastigotes. Full article

Periodontal disease is a chronic inflammatory condition driven by polymicrobial biofilms whose interaction with the host immune response drives the destruction of tooth-supporting tissues. Within these communities, bacterial cell–cell communication—particularly quorum sensing (QS)—coordinates virulence factor expression, biofilm maturation, and interspecies behaviour, allowing pathogens to mount population-dependent attacks on the host. Disrupting these signals has therefore drawn growing attention as an anti-virulence strategy for biofilm-associated oral infection. Quorum quenching (QQ)—the inhibition or disruption of QS pathways—prevents bacteria from coordinating these virulence-related activities. The candidate inhibitors investigated to date fall into three broad classes: conventional antibiotics used at sub-inhibitory concentrations, plant-derived natural compounds, and synthetic molecules designed to interfere with signal synthesis, signal reception, or signal transduction. In experimental work on periodontal pathogens, agents from each class reduce biofilm formation, suppress virulence factor production, and disrupt microbial communication within polymicrobial biofilms. Clinical translation, however, lags behind the laboratory evidence. Most data still come from in vitro systems and animal models, and the ecological complexity of the oral biofilm makes therapeutic targeting difficult: signals that drive virulence in pathogens also support cooperation among commensals. Toxicity profiles, pharmacokinetics, and well-powered clinical trials are needed before quorum-quenching agents can be considered for routine periodontal care. Even with these caveats, targeting bacterial communication offers a different therapeutic logic from conventional antimicrobials: attenuating virulence rather than killing cells, and so exerting weaker selective pressure for resistance. Further dissection of QS networks in oral biofilms—and the rational design of quenching agents that act on pathogenic rather than commensal signalling—may yield useful adjuncts to current periodontal therapy. Full article

Metal–organic frameworks (MOFs) offer unique opportunities for drug delivery due to their high porosity and the possibility of hosting large drug molecules within well-defined pore systems. In this work, the zirconium-based MOF NU-1000 was investigated as a carrier for the antineoplastic drug mitoxantrone (MTX). NU-1000 particles were synthesized and characterized by PXRD, SEM, and DLS, confirming their crystallinity, morphology, and size distribution. MTX loading was achieved by aqueous incubation and quantified by UV-Vis spectroscopy and thermogravimetric analysis, yielding a high loading capacity of ~40–43 wt%, with most of the uptake occurring within the first three hours. Structural characterization demonstrated that the MOF preserves its crystallinity and morphology after drug incorporation, while the DLS results suggest that MTX is mainly accommodated within the internal pore system. To improve stability under physiological conditions, the composite was coated with NH₂-PEG-NH₂, resulting in PEG@MTX@NU-1000 particles with enhanced stability in phosphate-buffered saline. Cytotoxicity assays in HeLa cells showed that the PEGylated carrier is largely biocompatible, while PEG@MTX@NU-1000 exhibits a significantly enhanced antiproliferative effect compared to free MTX at short incubation times. These results demonstrate that NU-1000 is a promising platform for MTX delivery, combining high loading capacity, structural stability after PEGylation, and improved short-term therapeutic performance. Full article

Sarcoptic mange is a skin disease caused by Sarcoptes scabiei infestations, characterized by dermatitis, pruritus, and exudative responses in both humans and animals. Biologically, the life cycle of S. scabiei is confined to the host’s skin (stratum corneum), where mite-derived molecules trigger the influx of innate immune cells, including polymorphonuclear neutrophils (PMN), which play a central role in skin inflammatory responses. The antimicrobial activity of PMNs is regulated by Ca²⁺ fluxes and includes the generation of reactive oxygen species (ROS), degranulation, and the release of neutrophil extracellular traps (NETs). NETs are web-like structures composed of chromatin and enzymes that can trap and eventually kill pathogens; however, their involvement in S. scabiei infestations in bovines remains unclear. Here, we investigated interactions between bovine PMN and S. scabiei mites, as well as PMN responses to S. scabiei antigen (ScAg). Functional parameters included NET release, Ca²⁺ fluxes, ROS production and phagocytic activity, determined by fluorescence microscopy, Fluo-4 staining, luminol-derived luminescence and flow cytometry, respectively. Current data show that ScAg, but not whole mites, induces a weak NET release in exposed bovine PMN. Additionally, ScAg drives rapid and sustained Ca²⁺ fluxes and ROS production over time, without altering the phagocytic capacity of PMN. Full article

Streptomyces species are major producers of bioactive molecules via biosynthetic gene clusters (BGCs). However, many BGCs are silent or poorly expressed in their native hosts, making heterologous expression hosts a key strategy for discovering novel natural products and efficiently producing known compounds. In this study, Streptomyces albus ZD11, an industrial salinomycin producer capable of efficiently utilizing soybean oil to supply abundant polyketide precursors, was selected as a candidate host for the expression of polyketide BGCs. A genome-reduced derivative, designated ZD12, was constructed by deleting four endogenous polyketide BGCs from ZD11, aiming to reduce precursor competition and alleviate metabolic burden. To evaluate the polyketide biosynthesis capacity of ZD12, an engineered spectinabilin BGC was heterologously expressed in both ZD12 and a commonly used heterologous host S. albus J1074. The resulting ZD12-derived strain DHM produced 412 mg/L spectinabilin, while the J1074-derived strain J-DHM produced 114 mg/L, both of which were significantly higher than the native production level in S. spectabilis. Notably, the titer in DHM exceeded the highest previously reported heterologous titer by more than threefold. Furthermore, under identical integration conditions, DHM achieved a 2.6-fold higher spectinabilin titer than J-DHM, demonstrating the superior polyketide biosynthesis capacity of ZD12. Full article

In this study, we combined computational predictions with experimental validation as a hybrid strategy to explore whether the E protein of tick-borne encephalitis virus (TBEV) possesses autoimmune potential. Using in silico homology searches, we identified two viral epitopes (evglekl and vtgtqgt) within the TBEV E protein that share sequence identity with fragments of the human proteins DNAH7 and CSMD2. Antibodies against these epitopes were detected in the plasma of a subset of patients after natural TBEV infection. Notably, no such antibodies were found in recipients of the Tick-E-Vac vaccine, indicating that the current vaccine does not induce cross-reactive humoral responses to these epitopes. Further computational analysis predicted that these epitopes could be presented by HLA class II molecules (alleles DRB1*09:01 and DRB1*07:01), which are known to be associated with autoimmune pathologies. Molecular dynamics simulations confirmed stable binding of the peptides within the HLA grooves, with favorable binding energies. These findings suggest a possible involvement of T-helper cells in the autoreactive process. Natural TBEV infection can give rise to antibodies against epitopes homologous to human proteins, particularly in genetically predisposed hosts. While such homology alone does not predict the onset of autoimmune disease, it represents a risk factor. Full article

Butyrophilin-like 2 (BTNL2) is an immunomodulatory molecule critically involved in regulating the host immune response to infection with the avirulent Mycobacterium tuberculosis strain H37Ra. However, its functional role in modulating pyroptosis and associated inflammatory responses remains incompletely characterized. Here, we demonstrate that BTNL2 deficiency exacerbates pyroptosis and the inflammatory response in H37Ra-infected murine peritoneal macrophages via two distinct pathways. First, the loss of BTNL2 induces excessive mitochondrial damage, which leads to aberrant release of mitochondrial DNA (mtDNA) and accumulation of mitochondrial reactive oxygen species (mtROS), thereby triggering NLRP3 (NOD-like receptor family pyrin domain containing 3) inflammasome activation and gasdermin D (GSDMD)-mediated pyroptosis. Second, cytosolic mtDNA accumulation hyperactivates the cGAS–STING signaling axis, resulting in transcriptional upregulation of NLRP3 and consequent amplification of pro-inflammatory cytokine production. Collectively, these findings demonstrate that BTNL2 acts as a regulator of mitochondrial homeostasis and innate immune balance during H37Ra infection in primary peritoneal macrophages. The results provide mechanistic insights into BTNL2 function in the context of H37Ra-induced pyroptosis. Full article

Impairment in blood supply to the brain deprives its cells of the much-needed nutrients and molecules such as oxygen and glucose necessary for its development, growth and survival. This will set up a host of pathological processes such as impaired homeostasis, energy failure, excitotoxicity, oxidative stress, impaired protein synthesis, inflammation, cytokine-mediated toxicity and impairment of blood–brain barrier. These pathological processes will result in the damage or death of the cells depending on the extent of the deprivation. Similarly, they will impair synthesis of acetylcholine (Ach) and norepinephrine (NE), which are important neurotransmitters in the cholinergic and adrenergic systems responsible for cellular communication and functions. Thus, interventions to help arrest and/or modulate the initial and subsequent pathological states and help recover the functions of the brain are needed. One of such interventions is vagus nerve stimulation, which helps activate the cholinergic and the adrenergic systems via projections of the afferent fibers of the vagus nerve to the nucleus of the solitary tract (NTS). Activation of the cholinergic and the adrenergic systems results in reduction in pro-inflammatory factors such as tumor necrosis α, increase in pro-angiogenic factors and increase in firing of adrenergic neurons in the central nervous system (CNS). Full article

Supramolecular inclusion complexes are widely used in drug delivery and other fields, with the advantages of controllable structures, high stability, excellent biocompatibility, and the ability to improve drug solubility and achieve controlled release. However, traditional screening methods rely on experimental trial and error, which suffer from long cycles, high costs, and low throughput, limiting research and development efficiency. In recent years, the development of artificial intelligence has provided new solutions for the screening of inclusion complexes. This paper systematically reviewed the core technological system of AI in the screening of inclusion complexes, focusing on two aspects: prediction and optimization of key properties and rational design of host molecules, summarizing their specific application progress. At the same time, we analyzed the current core challenges, including data scarcity, insufficient model interpretability, and limited generalization capabilities, and propose future development directions such as building standardized databases, integrating physicochemical principles (e.g., molecular mechanics and thermodynamics), and establishing closed-loop research and development platforms. This review aims to provide a systematic reference for the in-depth application of artificial intelligence in the field of supramolecular inclusion complexes. Full article

The increasing prevalence of drug-resistant microorganisms has prompted research into novel antimicrobial compounds, with 2-thiophene carboxylic acid thiourea derivatives showing promise for future therapeutic applications. However, the poor water solubility of these compounds limits their practical use. This study investigates the formation and characterization of inclusion complexes between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 2-thiophene carboxylic acid-halogenated (chlorine-, bromine-, and iodine-) thiourea derivatives, seeking to improve their physicochemical properties. The dynamic light scattering (DLS) measurements and UV-Vis spectroscopy provided information related to thiourea–HPβCD aggregates and stoichiometry. Solid-state inclusion compounds and physical mixtures were prepared in two different molar ratios (thioureas:HPβCD = 1:1 and 1:2), and the morphology of the resulting powders was observed by scanning electron microscopy (SEM). Thermogravimetry (TG) and differential scanning calorimetry (DSC) (TG-DSC) coupled analysis were used to analyze thermal profiles in the temperature range of 25 °C to 600 °C, while the spectral data obtained by Fourier transform infrared spectroscopy (FTIR) provided the characteristic vibrational bands of the pure guest molecules and data corresponding to the structural and chemical changes in the host–guest systems. The structural and thermal analyses revealed significant interactions between the host and thioureas molecules, with evidence of possible interactions involving two cyclodextrin molecules. The results demonstrate the presence of intermediate stoichiometry in the inclusion compounds, with possible enhancement of the therapeutic potential of these thiourea derivatives. Full article

Background: Aging profoundly alters host immunity, yet how age-associated immune changes in the liver influence the growth of metastatic tumors remains incompletely understood. Liver metastasis is a major cause of cancer-related mortality, particularly in elderly patients, for whom aggressive treatments are often not feasible. This study aimed to clarify how aging reshapes the hepatic immune microenvironment and to identify age-associated host factors that influence liver metastasis growth. Methods: Tumor-naïve and tumor-bearing young and aged mice were analyzed using a syngeneic MC38 liver metastasis model. Immune cell composition in the liver was assessed by flow cytometry, and gene expression was evaluated by quantitative reverse transcription PCR (RT–qPCR). Public transcriptomic datasets were screened to identify age-associated inflammatory factors. The functional relevance of the S100A8/A9 axis was examined using the small-molecule inhibitor paquinimod. Results: Aging was associated with a distinct baseline immune cell composition in the liver. During liver metastasis, overall growth was comparable between young and aged mice; however, metastatic lesions in aged hosts showed increased expression of multiple inflammation-related genes and prominent accumulation of Ly6G⁺ cells. In silico screening identified S100a9 as one of the most highly upregulated inflammation-related genes in aged livers, which was confirmed in both tumor-naïve and metastatic liver tissues. Pharmacological modulation of the S100A8/A9 axis with paquinimod significantly reduced liver metastasis growth in aged, but not young, mice, and was accompanied by a shift in immune cell composition, including an increased representation of CD8⁺ T cells. Conclusions: These findings indicate that aging is associated with a distinct hepatic immune context that shapes the inflammatory and cellular composition of the tumor microenvironment during liver metastasis. S100A9 emerges as a key age-associated, host-derived factor that is functionally relevant to the growth of liver metastases in aged hosts, supporting the S100A8/A9 axis as a context-specific therapeutic target. Full article

African swine fever virus (ASFV) is the causative agent of African swine fever (ASF), a fatal and highly contagious disease, resulting in enormous losses to the global swine industry. No licensed vaccines or effective therapeutics are currently available to control ASFV infection. Interferons (IFNs) serve as key mediators of host antiviral immunity by inducing interferon-stimulated genes (ISGs), but the specific mechanisms by which individual ISGs restrict ASFV replication remain unclear. Interferon-induced protein with tetratricopeptide repeats 3 (IFIT3, also called ISG60) has been shown to exhibit antiviral activity against various viruses, but its role in ASFV infection has not been previously studied. Here, we used porcine alveolar macrophages (PAMs), the primary target cells of ASFV, to investigate IFIT3’s function in ASFV replication. We found that overexpression of IFIT3 inhibited ASFV replication, while its knockdown enhanced viral propagation. Mechanistically, IFIT3 directly blocked ASFV adsorption to host cells, thereby suppressing all subsequent stages of the viral cycle. IFIT3 also specifically interacted with ASFV F334L, an early viral gene product that encodes the small subunit of ribonucleotide reductase, a key enzyme for viral DNA synthesis. Additionally, IFIT3 positively regulated the STAT1/TBK1/IRF3 signaling axis: its overexpression increased phosphorylation of TBK1 and IRF3, as well as the protein level of STAT1, while IFIT3 knockdown attenuated activation of these molecules. Transcriptomic analysis of IFIT3-knockout PAMs revealed significant suppression of innate immune pathways, including type I interferon, JAK-STAT, and RIG-I-like receptor pathways, along with downregulated expression of core antiviral molecules such as ISG15, MX1, and STAT1. Conversely, pathways related to viral adsorption, endocytosis, and cytoskeleton were activated, and pathways involved in protein translation initiation, endoplasmic reticulum stress, and autophagy were dysregulated, creating a favorable intracellular environment for ASFV replication. In conclusion, IFIT3 restricts ASFV replication possibly by inhibiting viral adsorption and promoting innate immune signaling, identifying it as a potential therapeutic target against ASFV. This study’s limitation is its in vitro PAM model; future work will validate IFIT3’s role in vivo and develop targeted inhibitors. Full article

Advances in mass spectrometry-based metabolomics have enabled the detection of numerous small molecules in biological systems, revealing complex metabolic alterations associated with cancer. Among these, dipeptides are consistently detected in plasma, serum, and tumor tissue metabolomic profiles, yet their biological significance is not fully understood. In most studies, circulating dipeptides are interpreted as nonspecific byproducts of protein degradation generated during increased proteolysis. However, accumulating evidence suggests that at least some endogenous dipeptides may have biological activities, including antioxidant effects, metabolic modulation, and potential signaling functions. In this review, we examine the possible origins, transport mechanisms, and biological implications of circulating dipeptides in cancer metabolomics. We discuss multiple sources of dipeptide generation, including intracellular proteolysis, autophagy, extracellular matrix remodeling, tumor cell death, host tissue catabolism, and microbiome metabolism. We also summarize current knowledge regarding peptide transport systems and intracellular dipeptide metabolism that may regulate the fate of these molecules within mammalian systems. In addition, evidence supporting the biological activities of certain endogenous dipeptides is reviewed to evaluate the possibility that some circulating dipeptides may function as bioactive metabolites. Finally, we propose conceptual frameworks for interpreting circulating dipeptides in cancer, including their potential roles as indicators of protein turnover, intermediates in amino acid recycling, stress-buffering molecules, metabolic signals, or components of tumor–host metabolic communication. A better understanding of circulating dipeptides may provide new insights into cancer metabolism and reveal previously overlooked metabolite classes with potential biomarker or functional significance. Full article

Mesenchymal stem/stromal cells (MSCs) are multipotent progenitor cells with potent immunomodulatory properties, making them attractive candidates for treating inflammatory and autoimmune diseases. A key mediator of MSC-induced immunosuppression is programmed death-ligand 1 (PD-L1), a checkpoint molecule that interacts with PD-1 on immune cells to regulate immune responses and promote tolerance. This review synthesizes current evidence on the role of PD-L1 expression in MSCs, emphasizing its effects on both the innate and adaptive immune systems, its therapeutic potential, and its utility as a biomarker for MSC potency and clinical efficacy. We examine how PD-L1 modulates T cell activation, dendritic cell maturation, macrophage polarization, and cytokine profiles, including its role in exosomal contexts. Additionally, we highlight its synergistic interactions with other immune checkpoints and discuss its dual function as both a therapeutic effector and a dynamic biomarker. Finally, we explore its relevance in clinical contexts such as autoimmune diseases, graft-versus-host disease, sepsis, and transplantation and conclude with a discussion of challenges and future directions in harnessing PD-L1 for MSC-based therapies. Full article