Search Results (810)

Alkaline pectate lyases hold significant promise for various industrial applications, including the degumming processes in papermaking and textiles. In this study, a novel pectinase, PelA, derived from a strain of Paenibacillus borealis, was characterized both at the molecular level and through enzymatic analysis. This enzyme represents a distinct cluster diverging from the well-characterized Bacillus pectinases and exhibits molecular activity under alkaline conditions, with an optimal pH of 9.5. It can be classified as an endo-(1,4)-pectate lyase, capable of cleaving the α-1,4 glycosidic bonds of polygalacturonic acid via a trans-elimination mechanism. Notably, the addition of the metal ion Ca²⁺ did not enhance enzyme activity. To achieve high-level secretory expression and improve its economic viability for bioapplications, the gene copy number of pelA in the host genome was increased by constructing tandem pelA gene expression cassettes. Following optimization of cultivation conditions and monitoring of cell growth, the recombinant strain harboring the multi-copy pelA gene attained an expression level of 7520 U/mL in a bioreactor. This study successfully achieved high-level secretory expression of an alkaline pectinase, thereby enhancing its potential for industrial bioapplications and providing a reference for future research on the heterologous expression of target genes. Full article

Myokines are secreted by muscle and play crucial roles in muscle repair and regeneration and also impact diverse physiological effects through crosstalk with other metabolic organs. However, aging is associated with a progressive decline in muscle mass, which in turn leads to reduced myokine secretion. This decline may contribute to the development of sarcopenia, leading to an increased risk of metabolic disorders such as type 2 diabetes. Accordingly, interest in identifying novel myokines and elucidating their biological functions is increasing. In this study, we explored the function of biglycan (BGN), a novel myokine, in aging-related metabolic tissues. BGN levels decreased in the muscle tissue and plasma of older adults and aged mice, whereas exercise intervention restored BGN expression in aged mice. BGN counteracted the expression of atrophy-related genes involved in muscle degradation and mitigated muscle mass loss by regulating AKT/mTOR signaling pathway. Notably, BGN decreased the expression of the senescence marker p21 and senescence-associated secretory phenotype (SASP)-related genes in hepatocytes. Additionally, BGN attenuated senescence-induced lipid accumulation and ROS generation. Our results suggest that BGN has beneficial effects against muscle atrophy and hepatocellular senescence, indicating its potential as a protective factor for age-related diseases. Full article

Background: African swine fever (ASF) is a highly contagious and often deadly disease that poses a major threat to swine production worldwide. The lack of a commercially available vaccine underscores the critical need for innovative immunization strategies to combat ASF. Methods: Six ASFV antigenic proteins (K78R, A104R, E120R, E183L, D117L, and H171R) were fused with the Lactiplantibacillus plantarum WCFS1 surface anchor LP3065 (LPxTG motif) to generate recombinant Lactiplantibacillus plantarum NC8 (rNC8) strains. The surface expression was confirmed using immunofluorescence and Western blotting assays. Additionally, the dendritic cell-targeting peptides (DCpep) were co-expressed with each antigen protein. Mice were immunized at a dosage of 10⁹ colony-forming units (CFU) per strain per mouse via intragastric (I.G.), intranasal (I.N.), and intravenous (I.V.) routes. The bacterial mixture was heat-inactivated by boiling for 15 min to destroy viable cells while preserving antigenic structures. I.V. administration caused no hypersensitivity, confirming the method’s safety and effectiveness. Results: Following I.G. administration, rNC8-E120R, rNC8-E183L, rNC8-K78R, and rNC8-A104R induced significant levels of secretory immunoglobulin A (sIgA) in fecal samples, whereas rNC8-H171R and rNC8-D117L failed to induce a comparable response. Meanwhile, rNC8-D117L, rNC8-K78R, and rNC8-A104R also elicited significant levels of sIgA in bronchoalveolar lavage fluid (BALF). Following I.N. immunization, rNC8-E120R, rNC8-K78R, and rNC8-A104R significantly increased sIgA levels in both fecal and BALF immunization. In contrast, I.V. immunization with heat-inactivated rNC8-K78R and rNC8-A104R induced robust serum IgG titers, whereas the remaining antigens elicited minimal or insignificant responses. Flow cytometry analysis revealed expanded CD3⁺CD4⁺ T cells in mice immunized via the I.N. and I.G. and CD3⁺CD4⁺ T cells only in those immunized via the I.N. route. Th1 responses were also significant in the sera of mice immunized via the I.G. and I.N. routes. Conclusions: The rNC8 multiple-antigen cocktail elicited strong systemic and mucosal immune responses, providing a solid foundation for the development of a probiotic-based vaccine against ASF. Full article

CD9 protein belongs to a family of proteins called tetraspanins, so named for their four-transmembrane-spanning architectures. These proteins are located in domains in the plasmatic membrane, called tetraspanin-enriched microdomains (TEMs). Several proteases and cellular receptors for virus entry cluster into TEMs, suggesting that TEMs are preferred virus entry portals. Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein mediates virus attachment and entry into cells by binding to human angiotensin-converting enzyme 2 (ACE-2). In addition, the secretory, type-I membrane-bound SARS-CoV-2 S protein is synthesized as a precursor (proS) that undergoes posttranslational cleavages by host cell proteases, such as furin and TMPRSS2. Moreover, it has been shown that neuropilin-1 (NRP1), which is known to bind furin-cleaved substrates, potentiates SARS-CoV-2 infectivity. Our results indicate that CD9 facilitates SARS-CoV-2 infection. In addition, we show how knocking out CD9 leads to a decrease in the expression of NRP1, a protein that improves SARS-CoV-2 infection. Furthermore, we show that CD9 colocalizes with ACE-2, NRP1, furin, and TMPRSS2 at the plasma membrane; that the absence of CD9 decreases the expression of these proteins on the plasma membrane CD9-enriched microdomains, and that CD9 interacts with ACE2. In conclusion, our data suggest that CD9 facilitates SARS-CoV-2 infection and that CD9 brings together different host proteins involved in SARS-CoV-2 attachment and entry into host cells, such as ACE2, NRP1, furin, and TMPRSS2. Importantly, the fact that a blocking antibody targeting CD9 can effectively reduce SARS-CoV-2 titers highlights not only the mechanistic role of CD9 in viral entry but also offers translational potential, suggesting that tetraspanin-targeting antibodies could be developed as therapeutic agents against SARS-CoV-2 and possibly other coronaviruses, with meaningful implications for clinical intervention. Full article

Cystic fibrosis is a multisystem disorder caused by mutations in the CFTR gene that lead to impaired ion and fluid transport across secretory epithelia. Although the therapeutic impact of CFTR modulators has been extensively studied in airway epithelia, their efficacy in extra-pulmonary tissues, such as the pancreas, has been less explored. This study evaluated the effects of the CFTR modulators, VX770 (ivacaftor), VX661 (tezacaftor), and VX445 (elexacaftor), administered either individually or in combination, on CFPAC-1 cells, a pancreatic ductal epithelial cell line derived from a cystic fibrosis patient harboring the F508del CFTR mutation. The cells were cultured and differentiated onto porous supports, and a panel of functional parameters was assessed. These included transepithelial electrical conductance, fluid reabsorption, apical surface fluid pH, protein concentration, and microviscosity, the latter analyzed with multiple particle tracking. To simulate a pro-inflammatory micro-environment, the cells were preconditioned with lipopolysaccharide (LPS). Treatment with VX661 and VX445 resulted in significant improvement in epithelial function, with the triple combination producing the most pronounced rescue. Pro-inflammatory stimulation by LPS increased the production of cytokine IL6, IL-8, and IL-1β, as well as the protein content of the apical surface fluid. Despite the LPS pro-inflammatory stimulus, CFTR modulators preserved or slightly enhanced their efficacy in restoring CFTR-mediated ion and fluid transport. However, they did not reduce cytokine expression under pro-inflammatory conditions. Collectively, these findings show that CFTR modulators can restore critical aspects of cystic fibrosis pancreatic epithelial physiology in vitro, even under pro-inflammatory stress, supporting their potential relevance beyond the airway disease. Full article

Conidiobolus coronatus (Entomophthorales), a fungal pathogen with a broad insect host range, is a promising candidate for biocontrol applications. We sequenced a C. coronatus strain isolated from a Rhopalomyia sp. cadaver using PacBio long-read sequencing to elucidate the molecular basis of its wide host adaptability. The newly assembled 44.21 Mb genome exhibits high completeness (BUSCO score: 93.45%) and encodes 11,128 protein-coding genes, with 23.1% predicted to mediate pathogen–host interactions. Comparative genomics with the aphid-obligate pathogen C. obscurus revealed significant expansions in gene families associated with host adaptation mechanisms, including host recognition, transcriptional regulation, degradation of host components, detoxification, and immune evasion. Functional annotation highlighted enrichment in cellular component organization and energy metabolism. Pfam annotation identified one hundred twenty-five seven-transmembrane receptors (putative GPCRs), sixty-seven fungus-specific transcription factors, three hundred sixty-one peptidases (one hundred ninety-eight serine proteases and one hundred three metalloproteases), one hundred twenty-seven cytochrome P450 monooxygenases (P450s), thirty-five cysteine-rich secretory proteins, and fifty-five tyrosinases. Additionally, four hundred thirty carbohydrate-active enzymes (CAZymes) across six major modules were characterized. Untargeted metabolomics detected 22 highly expressed terpenoids, consistent with terpenoid biosynthesis gene clusters in the genome. Collectively, these expansions underpin the broad host range of C. coronatus by enabling cross-host signal decoding and gene expression reprogramming, breaching diverse host physicochemical barriers, and expanding its chemical ecological niche. This study provides genomic insights into broad host adaptability in entomopathogenic fungi, facilitating further understanding of pathogen–host interactions. Full article

Mesenchymal stem cells (MSCs), i.e., adult stem cells with immunomodulatory and secretory properties, contribute to tissue growth and regeneration, including healing processes. Some metal nanoparticles (NPs) are known to exhibit antimicrobial activity and may further potentiate tissue healing. We studied the effect of Ag, CuO, and ZnO NPs after in vitro exposure of mouse MSCs at the transcriptional level in order to reveal the potential toxicity as well as modulation of other processes that may modify the activity of MSCs. mRNA–miRNA interactions were further investigated to explore the epigenetic regulation of gene expression. All the tested NPs mediated immunomodulatory effects on MSCs, generation of extracellular vesicles, inhibition of osteogenesis, and enhancement of adipogenesis. Ag NPs exhibited the most pronounced response; they impacted the expression of the highest number of mRNAs, including those encoding interferon-γ-stimulated genes and genes involved in drug metabolism/cytochrome P450 activity, suggesting a response to the potential toxicity of Ag NPs (oxidative stress). Highly interacting MiR-126 was upregulated by all NPs, while downregulation of MiR-92a was observed after the ZnO NP treatment only, and both effects might be associated with the improvement of MSCs’ healing potency. Overall, our results demonstrate positive effects of NPs on MSCs, although increased oxidative stress caused by Ag NPs may limit the therapeutical potential of the combined MSC+NP treatment. Full article

Background: Senescence, a state of permanent cell cycle arrest, is a complex cellular phenomenon closely affiliated with age-related diseases and pathological fibrosis. Cellular senescence is now recognized as a significant contributor to organ fibrosis, largely driven by transforming growth factor beta (TGF-β) signaling, such as in metabolic dysfunction-associated steatohepatitis (MASH), idiopathic pulmonary fibrosis (IPF), chronic kidney disease (CKD), and myocardial fibrosis, which can lead to heart failure, cystic fibrosis, and fibrosis in pancreatic tumors, to name a few. MASH is a progressive inflammatory and fibrotic liver condition that has reached pandemic proportions, now considered the largest non-viral contributor to the need for liver transplantation. Methods: We previously studied Oxy210, an anti-fibrotic and anti-inflammatory, orally bioavailable, oxysterol-based drug candidate for MASH, using APOE*3-Leiden.CETP mice, a humanized hyperlipidemic mouse model that closely recapitulates the hallmarks of human MASH. In this model, treatment of mice with Oxy210 for 16 weeks caused significant amelioration of the disease, evidenced by reduced hepatic inflammation, lipid deposition, and fibrosis, atherosclerosis and adipose tissue inflammation. Results: Here we demonstrate increased hepatic expression of senescence-associated genes and senescence-associated secretory phenotype (SASP), correlated with the expression of pro-fibrotic and pro-inflammatorygenes in these mice during the development of MASH that are significantly inhibited by Oxy210. Using the HepG2 human hepatocyte cell line, we demonstrate the induced expression of senescent-associated genes and SASP by TGF-β and inhibition by Oxy210. Conclusions: These findings further support the potential therapeutic effects of Oxy210 mediated in part through inhibition of senescence-driven hepatic fibrosis and inflammation in MASH and perhaps in other senescence-associated fibrotic diseases. Full article

Disparities in the functional classification of secretory genes among aphid taxa may be attributed to variations in coding sequences and gene expression profiles. However, the driving factors that regulate sequence evolution remain unclear. This study aimed to investigate the differences in coding sequences and expression patterns of secretory genes between the rose grain aphid (Metopolophium dirhodum) and the pea aphid (Acrythosiphon pisum), with a particular focus on their roles in evolutionary adaptations and functional diversity. The study involved the rearing of aphids, RNA extraction, de novo transcriptome assembly, functional annotation, secretory protein prediction, and comparative analysis of coding sequences and expression patterns across various functional categories using bioinformatics tools. The results revealed that metabolic genes exhibited greater coding sequence divergence, indicating the influence of positive selection. Moreover, significant expression divergence was noted among functional categories, particularly in metabolic and genetic information processing genes, which exhibited higher variability. This study enhances our understanding of the molecular mechanisms that contribute to phenotypic and genetic diversity among aphid species. This study elucidates the relationship between variations in coding sequences and differences in gene expression among functional categories, thereby establishing a foundation for future studies on gene evolution in response to environmental pressures. Full article

Suckling is crucial for piglet intestinal development and gut health, as it improves resilience during the challenging weaning phase and promotes subsequent growth. IPS, comprising Na⁺/K⁺ ions, whey protein, and glucose, has been shown to have positive effects on animal growth and intestinal health. The objectives of this study were to assess the impact of IPS consumption on the growth performance, immunity, intestinal growth and development, and microbiota structure of suckling piglets. A total of 160 newborn piglets were randomly divided into control and IPS groups, with IPS supplementation starting from 2 to 8 days after birth and continuing until 3 days before weaning. The findings revealed that IPS boosted the body weight at 24 days by 3.6% (p < 0.05) and improved the body weight gain from 16 to 24 days by 15.7% (p < 0.05). Additionally, the jejunal villus height and villus height to crypt depth ratio in the IPS group were notably increased to 1.08 and 1.31 times (p < 0.05), respectively, compared to the control group. Furthermore, IPS elevated the plasma levels of IgA and IgM, reduced the plasma levels of blood urea nitrogen (BUN), and enhanced the content of secretory immunoglobulin A (SIgA) in the jejunal mucosa of suckling piglets. Furthermore, IPS upregulated the mRNA expression of tight junction proteins GLP-2, ZO-1, and Claudin-1 in jejunal tissue, while downregulating the regulatory genes in the Toll-like pathway, including MyD88 and TLR-4 (p < 0.05). The analysis of gut microbiota indicated that IPS altered the relative abundance of gut microbes, with an increase in beneficial bacteria like Alloprevotella and Bacteroides. In conclusion, this study demonstrates that IPS supplementation enhances weaning weight, growth performance, immune function, and intestinal development in piglets, supporting the integration of IPS supplementation in the management of pre-weaning piglets. Full article

We identified Murashka, a RING finger protein, in an oogenesis screen as a regulator of Drosophila ovary germline stem cell niche development. Mutant alleles of murashka exhibited an enlarged niche phenotype reminiscent of increased Notch signalling and displayed genetic interactions with Notch alleles, and with polychaetoid, a regulator of Notch during niche development. These interactions uncovered both positive and negative impacts on Notch in different genetic backgrounds. In S2 cells, Murashka formed a complex with Notch and colocalised with Notch in the secretory pathway. Murashka expression in S2 cells down-regulated Notch signalling levels but could result in increased fold induction due to the proportionally greater decrease in basal ligand-independent activity. In vivo Murashka expression had different outcomes on different Notch target genes. We observed a decrease in the expression of vestigial along the anterior/posterior boundary of the wing imaginal disc, but not of wingless at the dorsal/ventral boundary. Instead, weak ectopic wingless was observed, which was synergistically increased by the coexpression of Deltex, a positive regulator of ligand-independent signalling. Our results identify a novel developmental role for murashka, a gene previously only associated with a function in long-term memory, and indicate a regulatory role for Murashka through a physical interaction with Notch that has context-dependent outcomes. Murashka adds to a growing number of ubiquitin ligase regulators which interact with Notch at different locations within its secretory and endocytic trafficking pathways. Full article

Thyroid hormones (thyroxine, T₄, and triiodothyronine, T₃) are indispensable for sustaining vertebrate life, and their deficiency gives rise to a wide range of symptoms characteristic of hypothyroidism, affecting 5–10% of the world’s population. The precursor for thyroid hormone synthesis is thyroglobulin (Tg), a large iodoglycoprotein consisting of upstream regions I-II-III (responsible for synthesis of most T₄) and the C-terminal CholinEsterase-Like (ChEL) domain (responsible for synthesis of most T₃, which can also be generated extrathyroidally by T₄ deiodination). Using CRISPR/Cas9-mediated mutagenesis, we engineered a knock-in of secretory ChEL into the endogenous TG locus. Secretory ChEL acquires Golgi-type glycans and is properly delivered to the thyroid follicle lumen, where T₃ is first formed. Homozygous knock-in mice are capable of thyroidal T₃ synthesis but largely incompetent for T₄ synthesis such that T₄-to-T₃ conversion contributes little. Instead, T₃ production is regulated thyroidally by thyrotropin (TSH). Compared to cog/cog mice with conventional hypothyroidism (low serum T₄ and T₃), the body size of ChEL-knock-in mice is larger; although, these animals with profound T₄ deficiency did exhibit a marked elevation of serum TSH and a large goiter, despite normal circulating T₃ levels. ChEL knock-in mice exhibited a normal expression of hepatic markers of thyroid hormone action but impaired locomotor activities and increased anxiety-like behavior, highlighting tissue-specific differences in T₃ versus T₄ action, reflecting key considerations in patients receiving thyroid hormone replacement therapy. Full article

Replicative or stress-induced senescence disrupts the functioning of multipotent mesenchymal stromal cells (MSCs) required for tissue renewal and regeneration. Aged MSCs demonstrate reduced proliferation, impaired differentiation, and aberrant secretory activity, defined as “senescence-associated secretory phenotype” (SASP). SASP is characterized by elevated secretion of proinflammatory cytokines and specific extracellular vesicles (SASP-EVs), which affect the cellular microenvironment and promote tissue dysfunction. However, molecular mechanisms responsible for senescent phenotype propagation remain largely obscure. Earlier, we demonstrated suppression of adipogenic differentiation and insulin sensitivity of young MSCs by SASP-EVs. In this study, we elucidated potential mechanisms underlying SASP-EVs’ effects on MSCs. Bioinformatic analysis revealed that insulin signaling components are the most probable targets of SASP-EVs microRNA cargo. We demonstrated that SASP-EVs downregulated intracellular AGO1 levels, but surprisingly, PTEN levels were upregulated. Specifically, the increase in PTEN content was provided by its nuclear fraction. We have found that the intracellular PTEN distribution in young MSCs treated by SASP-EVs was similar to senescent MSCs. Furthermore, PTEN upregulation was accompanied by increased PTENP1 expression—a molecular sponge for PTEN-targeting microRNAs. Our findings indicate that nuclear PTEN could be a hallmark of senescent MSCs, and SASP-EVs propagate the senescent phenotype in young MSCs by promoting PTEN nuclear localization. Full article

Enteroendocrine cells (EECs) are specialized secretory cells in the gut epithelium that differentiate from intestinal stem cells (ISCs). Mature EECs secrete incretin hormones that stimulate pancreatic insulin secretion and regulate appetite. Decreased EEC numbers and impaired secretion of the incretin glucagon-like peptide-1 (GLP1) have been implicated in obesity-associated metabolic complications. Gut microbial metabolites of dietary tryptophan (TRP) were recently shown to modulate ISC proliferation and differentiation. However, their specific effects on EEC differentiation are not known. We hypothesized that the gut microbial metabolites of dietary tryptophan counteract impaired GLP1 production and function in obesity by stimulating EEC differentiation from ISCs. We utilized complementary models of human and rat intestines to determine the effects of obesity or TRP metabolites on EEC differentiation. EEC differentiation was assessed by the EEC marker chromogranin A (CHGA) levels in the intestinal mucosa of normal versus obese rats. The effects of TRP metabolites on EEC differentiation were determined in human intestinal organoids treated with indole, a primary TRP metabolite, or the culture supernatant of Lactobacillus acidophilus grown in TRP media (LA-CS-TRP). Our results showed that the mRNA and protein levels of CHGA, the EEC marker, were significantly decreased (~60%) in the intestinal mucosa of high-fat-diet-induced obese rat intestines. The expression of the transcription factors that direct the ISC differentiation towards the EEC lineage was also decreased in obesity. In human organoids, treatment with indole or LA-CS-TRP significantly increased (more than 2-fold) CHGA levels, which were blocked by the aryl hydrocarbon receptor (AhR) antagonist CH-223191. Thus, the stimulation of EEC differentiation by colonic microbial metabolites highlights a novel therapeutic role of TRP metabolites in obesity and associated metabolic disorders. Full article

Tissue-resident macrophages are essential for skin homeostasis. This study investigated whether lipopolysaccharide (LPS)-activated macrophages affect senescence and rejuvenation in human dermal fibroblasts. Human monocytic THP-1 cells were stimulated with Pantoea agglomerans–derived LPS (1–1000 ng/mL), and culture supernatants were collected. These were applied to two NB1RGB fibroblast populations: young, actively dividing cells (Young cells) and senescent cells with high population doubling levels and reduced proliferation (Old cells). Senescence markers P16, P21, and Ki-67 were analyzed at gene and protein levels. Conditioned medium from Old cells induced senescence in Young cells, increasing P16 and P21 expression levels. This effect was suppressed by cotreatment with LPS-activated THP-1 supernatant. Old cells treated with the LPS-activated supernatant exhibited decreased P16 and P21 levels as well as increased Ki-67 expression, indicating partial rejuvenation. These effects were not observed following treatment with unstimulated THP-1 supernatants or LPS alone. Overall, these findings suggest that secretory factors from LPS-activated macrophages can suppress cellular senescence and promote human dermal fibroblast rejuvenation, highlighting the potential role of macrophage activation in regulating cellular aging and offering a promising strategy for skin aging intervention. Full article