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Search Results (647)

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20 pages, 558 KB  
Review
Genetic Predisposition and Genetic Resilience Factors in Stress-Related Disorders During the Developmental Age: A Narrative Review
by Alessia Raffagnato, Arianna Raicich, Lisa Paiusco, Giulia Coser, Ilaria Bonemazzi, Andrea Gazzin, Maria Federica Pelizza, Caterina Ancora and Irene Toldo
Genes 2025, 16(11), 1362; https://doi.org/10.3390/genes16111362 - 10 Nov 2025
Viewed by 197
Abstract
Background: Stress-related disorders, including PTSD, acute stress disorders, adjustment disorder, and attachment disorders, arise from complex interactions between genetic susceptibility and environmental stressors. While early environmental factors play a central role in the development of these disorders, there is growing evidence that genetic [...] Read more.
Background: Stress-related disorders, including PTSD, acute stress disorders, adjustment disorder, and attachment disorders, arise from complex interactions between genetic susceptibility and environmental stressors. While early environmental factors play a central role in the development of these disorders, there is growing evidence that genetic predisposition also contributes to individual differences in vulnerability and resilience. This narrative review examines current evidence on genetic predisposition and resilience mechanisms in stress-related psychopathology during developmental age. Methods: A literature search was performed using PubMed, Cochrane, MedRxiv, and Medline databases, focusing on studies published between 2010 and 2025, written in English, in the pediatric and adolescent population. Priority was given to original research articles and high-impact reviews. Studies were selected based on relevance to the genetic mechanisms underlying vulnerability and resilience to stress. 71 of 317 were selected. Two hundred forty-six articles were excluded due to a lack of relevance to the topic or because they included an adult population. Results: Polymorphisms and epigenetic modifications in genes involved in hypothalamus–pituitary–adrenal axis (FKBP5, NR3C1, ADCYAP1R1 and ACE), serotoninergic (SLC6A4 and HTR2A), noradrenergic and dopaminergic system (COMT and MAOA), BDNF, estrogen receptor and excitatory amino acid transporters are associated with increased risk of psychopathology following early trauma, but are also implicated in the development of resilience. Conclusions: Genetic factors influence both vulnerability and resilience to stress-related disorders. However, further studies based on the role of genetics are needed to advance precision and personalized medicine, which is still largely underexplored to this day in the field of stress-induced disorders. Full article
(This article belongs to the Special Issue Genetics of Neuropsychiatric Disorders)
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14 pages, 2167 KB  
Article
Comparative Transcriptomic and Proteomic Analyses Identify Byssogenesis-Associated Genes in the Mediterranean Mussel Mytilus galloprovincialis Lamarck, 1819
by Xiuwei Zhen, Yiwen Chen, Wei Zhang, Yongren Li, Li Li, Haigang Qi and Shoudu Zhang
Int. J. Mol. Sci. 2025, 26(21), 10511; https://doi.org/10.3390/ijms262110511 - 29 Oct 2025
Viewed by 221
Abstract
Mussels’ byssus and their adhesion ability play a crucial role in their attachment and artificial cultivation of mussels. In this study, transcriptomic and proteomic analyses were performed to identify byssogenesis-associated genes in the Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819, seeking to advance our [...] Read more.
Mussels’ byssus and their adhesion ability play a crucial role in their attachment and artificial cultivation of mussels. In this study, transcriptomic and proteomic analyses were performed to identify byssogenesis-associated genes in the Mediterranean mussel Mytilus galloprovincialis Lamarck, 1819, seeking to advance our knowledge of the molecular basis of byssal secretion in mussels. Transcriptomic analysis identified 1742 and 1498 differentially expressed genes in the foot tissue of M. galloprovincialis at 9 h and 24 h post-byssal ablation, respectively. Meanwhile, proteomic analysis revealed 1254 and 484 differentially expressed proteins at the same two time points. Integrated analysis identified 121 genes differentially expressed at both transcript and protein levels. Among these genes, 44 were significantly upregulated, and they may constitute high-confidence gene sets associated with mussel byssogenesis. Notably, they included genes encoding tyrosinase-like protein, low affinity immunoglobulin epsilon Fc receptor, and O-methyltransferase MdmC. They were enriched in KEGG pathways, including metabolism of amino acids, lipid metabolism, nucleotide metabolism, and immune system. Quantitative real-time PCR was performed on seven selected genes, confirming that their expression patterns were consistent with those observed in transcriptomic and proteomic sequencing. This study provides novel data and insights for understanding the molecular basis involved in byssus development of M. galloprovincialis. Full article
(This article belongs to the Section Molecular Genetics and Genomics)
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9 pages, 1535 KB  
Article
Heparin Provides Antiviral Activity Against Rhinovirus-16 via an Heparan Sulfate Proteoglycan-Independent Mechanism
by Leanne C. Helgers, Killian E. Vlaming, Tanja M. Kaptein, Julia Eder, Jan Willem Duitman and Teunis B. H. Geijtenbeek
Int. J. Mol. Sci. 2025, 26(21), 10393; https://doi.org/10.3390/ijms262110393 - 25 Oct 2025
Viewed by 287
Abstract
Human rhinovirus 16 (HRV-16) is a major cause of common colds and can exacerbate asthma and COPD, yet no approved antiviral treatments exist. Heparin, a highly sulfated polysaccharide, is known to block viral infection of many viruses that require attachment to heparan sulfate [...] Read more.
Human rhinovirus 16 (HRV-16) is a major cause of common colds and can exacerbate asthma and COPD, yet no approved antiviral treatments exist. Heparin, a highly sulfated polysaccharide, is known to block viral infection of many viruses that require attachment to heparan sulfate proteoglycans (HSPGs). Here, we investigated whether heparin inhibits HRV-16 infection. HRV-16 uses ICAM-1 as its attachment receptor and lacks a confirmed HSPG-binding mechanism. Notably, heparin inhibited HRV-16 infection in vitro in a dose- and time-dependent manner. Pre-treatment of either cells or virus particles with unfractionated heparin significantly reduced HRV-16 RNA expression at 24 and 48 h post-infection. In contrast, low-molecular-weight heparins blocked infection of HRV-16 significantly less effectively compared to unfractionated heparins. Our findings suggest that the inhibitory effect of unfractionated heparin on HRV-16 infection is likely independent of specific HSPGs interactions and may be mediated by the size and highly negative charge of unfractionated heparin. Importantly, the ability of unfractionated heparin to block viruses that do not require HSPGs for attachment implies a broader antiviral potential as a prophylactic or therapeutic agent against a variety of respiratory viruses. Full article
(This article belongs to the Special Issue Respiratory Virus Infection)
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29 pages, 1625 KB  
Review
Finding the Sweet Spot for the Treatment of B Cell Malignancies
by Valerie R. Wiersma
Cancers 2025, 17(20), 3366; https://doi.org/10.3390/cancers17203366 - 18 Oct 2025
Viewed by 548
Abstract
The glycan profile of cells comprises a high variety of sugar moieties that are attached to proteins (glycoproteins) and lipids (glycolipids) via a process called ‘glycosylation’. Cancer cells commonly carry aberrant glycans, which may be of interest for cancer diagnosis, prognosis, as well [...] Read more.
The glycan profile of cells comprises a high variety of sugar moieties that are attached to proteins (glycoproteins) and lipids (glycolipids) via a process called ‘glycosylation’. Cancer cells commonly carry aberrant glycans, which may be of interest for cancer diagnosis, prognosis, as well as the development of novel therapeutic strategies. This review focuses on the differential glycosylation patterns on malignant B cells, including both B cell lymphoma and leukemia. Well-known aberrant glycan profiles on malignant B cells include acquired high mannose N-glycans in the B cell receptor (BCR) of follicular lymphoma (FL), and increased expression of the glycosphingolipid Gb3/CD77 on Burkitt’s lymphoma (BL). These structures can be exploited for therapy by using lectins that specifically recognize these patterns with intrinsic cytotoxic activity or in a drug-conjugate format. Furthermore, immunotherapy can be improved by modulating glycans, especially sialic acids. Targeting glycans for immunotherapy is also of interest for chimeric antigen receptor (CAR) T cell therapy, a relatively novel therapy that has been quite effective in various B cell malignancies. Thus, the glycan profile of malignant B cells harbors many opportunities for therapeutic targeting. It is anticipated that further in-depth glycan profiling will open up many more opportunities for the treatment of B cell malignancies. Full article
(This article belongs to the Special Issue Oncology: State-of-the-Art Research in The Netherlands)
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23 pages, 3461 KB  
Article
Plasmonic Nanosensors for EGFR Detection: Optimizing Aptamer-Based Competitive Displacement Assays
by Alexandra Falamas, Andra-Sorina Tatar, Sanda Boca and Cosmin Farcău
Biosensors 2025, 15(10), 699; https://doi.org/10.3390/bios15100699 - 15 Oct 2025
Viewed by 615
Abstract
This study presents a comparative investigation of plasmonic sensing platforms based on colloidal gold nanoparticle (AuNP) suspensions and gold film over nanosphere (AuFoN) solid substrates for the detection of epidermal growth factor receptor (EGFR), an essential biomarker and therapeutic target in oncology. The [...] Read more.
This study presents a comparative investigation of plasmonic sensing platforms based on colloidal gold nanoparticle (AuNP) suspensions and gold film over nanosphere (AuFoN) solid substrates for the detection of epidermal growth factor receptor (EGFR), an essential biomarker and therapeutic target in oncology. The strategy relies on fluorescence emission modulation of an Atto647N-labeled DNA oligomer competitively bound to an EGFR-specific aptamer. Our results demonstrate that the colloidal AuNPs can function as competitive binding sensors, leading to fluorescence quenching upon fluorophore attachment to the surface of the NPs and partial fluorescence recovery due to EGFR-induced displacement of the fluorophore–aptamer complex. This specificity was confirmed by reversed binding experiments. However, the system proved highly sensitive to the experimental design: excessive washing (centrifugation) led to unspecific aggregation and signal loss, while reduced washing steps improved signal retention and revealed EGFR-induced fluorophore displacement into the supernatant. On the contrary, film-based substrates exhibited strong initial fluorescence, but failed to retain the fluorophore–aptamer complex after washing, resulting in fluorescence decay independent of EGFR incubation. This indicates that AuFoN lacked the binding stability necessary for specific displacement-based sensing. These findings highlight that while colloidal AuNPs can support competitive binding detection, their reproducibility is limited by colloidal stability and protocol sensitivity, whereas AuFoN substrates require improved surface functionalization strategies. The study emphasizes the critical role of surface chemistry, aptamer–fluorophore affinity, and washing protocols in determining the success or failure of plasmon-enhanced aptamer-based biosensing systems and suggests opportunities for improving specificity and robustness in future designs. Full article
(This article belongs to the Special Issue Aptamer-Based Sensing: Designs and Applications)
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19 pages, 2639 KB  
Article
Estradiol Triggers Cerebellar MLI-PC LTP via ERβ/Protein Kinase C Signaling Cascades in Mice In Vivo
by Zhao-Yi Zhang, Li Chen, Ming-Ze Sun, Chao-Yue Chen, Chun-Yan Wang, Yuki Todo, Zheng Tang, Yan-Cong Lv, Qin-Yong Zou, Chun-Ping Chu, Yin-Hua Xu and De-Lai Qiu
Int. J. Mol. Sci. 2025, 26(20), 9973; https://doi.org/10.3390/ijms26209973 - 14 Oct 2025
Viewed by 301
Abstract
17β-estradiol (E2) enhances the cerebellar molecular layer interneurons (MLIs)—Purkinje cells (PCs) synaptic transmission via activation of the Erβ in vivo in mice. Whether E2 regulates cerebellar MLI-PC synaptic plasticity is unknown. To investigate the mechanism of E2, we evaluated the modulation of facial [...] Read more.
17β-estradiol (E2) enhances the cerebellar molecular layer interneurons (MLIs)—Purkinje cells (PCs) synaptic transmission via activation of the Erβ in vivo in mice. Whether E2 regulates cerebellar MLI-PC synaptic plasticity is unknown. To investigate the mechanism of E2, we evaluated the modulation of facial stimulation-evoked MLI-PC long-term plasticity in mice. Cell-attached recordings from PCs of Crus II were performed using an Axopatch-700B patch-clamp amplifier. The MLI-PC synaptic transmission was evoked by facial stimulation. Immunohistochemistry was used to detect the expression of ERβ. Under control conditions, 1 Hz facial stimuli induced long-term depression (LTD) at MLI-PC synapses, characterized by a sustained reduction in P1 amplitude and a simple spike (SS) pause. The facial stimulus-induced MLI-PC LTD was completely prevented by E2, but this effect was reversed by a selective ERα/ERβ antagonist, ICI182780. Blockade of cannabinoid receptor 1 (CB1R) eliminated the MLI-PC LTD under control conditions, but revealed an E2-triggered long-term potentiation (LTP). The E2-triggered MLI-PC LTP persisted in the presence of an ERα antagonist but was absent in the presence of an ERβ antagonist PHTPP. The E2-triggered MLI-PC LTP remained unaffected by protein kinase A inhibition but was abolished by inhibition of protein kinase C (PKC) and intracellular Ca2+ depletion. Moreover, ERβ immunoreactivity was abundantly distributed around dendrites and somas of PCs in the Crus II region of the mouse cerebellar cortex. The present results suggest that E2 activates ERβ, thereby triggering facial stimulation-induced MLI-PC LTP via the PKC signaling cascade, which occludes CB1R-dependent MLI-PC LTD in the cerebellar cortex of mice in vivo. Full article
(This article belongs to the Special Issue Brain Plasticity in Health and Disease)
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27 pages, 3600 KB  
Article
TREM-1 Interacts with Rotavirus Proteins and Drives Inflammatory Responses: A Combined Experimental and Computational Approach
by Amanda de Oliveira Matos, José Rodrigues do Carmo Neto, Fernanda Craveiro Franco, Jefferson do Carmo Dietz, Pedro Henrique dos Santos Dantas, Andrei Giacchetto Felice, Adriana Luchs, Milton Adriano Pelli de Oliveira, Artur Christian Garcia da Silva, Siomar de Castro Soares, Simone Gonçalves da Fonseca, Fátima Ribeiro-Dias, Bruno Junior Neves, Carolina Horta Andrade, Marcelle Silva-Sales and Helioswilton Sales-Campos
Pathogens 2025, 14(10), 1029; https://doi.org/10.3390/pathogens14101029 - 10 Oct 2025
Viewed by 554
Abstract
Rotavirus (RV) is one of the main etiologic agents associated with diarrheal diseases (DDs), being responsible for approximately 200 thousand deaths annually. Currently, there are still many aspects regarding the virus biology, cell cycle, and pathophysiology of RV that need further elucidation. Therefore, [...] Read more.
Rotavirus (RV) is one of the main etiologic agents associated with diarrheal diseases (DDs), being responsible for approximately 200 thousand deaths annually. Currently, there are still many aspects regarding the virus biology, cell cycle, and pathophysiology of RV that need further elucidation. Therefore, the present work aimed to investigate whether the triggering receptor expressed on myeloid cells 1 (TREM-1) might be associated with RV infection. This immune receptor has been observed as an amplifier of inflammatory responses in different infectious and non-infectious diseases, including inflammatory bowel disease and celiac disease. Initially, we searched for public transcriptomic data regarding RV infection and the expression of TREM-1 and its associated genes, which were significantly upregulated in infected mice and children. Then, we infected monocytes with the virus, with or without a TREM-1 inhibitor. The inhibition of the receptor’s activity resulted in a significant decrease in IL-1β production. We also observed a reduction in cytopathic effects when MA104 cells were treated with TREM-1 inhibitors and then infected with simian RV. To further elucidate the interactions between the virus and TREM-1, in silico tools were used to simulate interactions between the receptor and RV proteins. These simulations suggested the occurrence of interactions between TREM-1 and VP5*, a protein involved in viral attachment to target cells, and also between the receptor and NSP4, a viral enterotoxin with immunostimulant properties. Hence, our results indicate that TREM-1 is involved in RV infection, both as a mediator of inflammatory responses and as a player in the host–virus relationship. Full article
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16 pages, 8225 KB  
Article
SNARE Protein CfSec22 Mediates Vesicular Trafficking to Regulate Growth, Conidiogenesis, and Pathogenesis of Ceratocystis fimbriata
by Changgen Li, Yiming Wang, Xiaoying Cao, Kailun Lu, Lianwei Li and Jihong Jiang
Microorganisms 2025, 13(10), 2305; https://doi.org/10.3390/microorganisms13102305 - 5 Oct 2025
Viewed by 375
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play evolutionarily conserved roles in intracellular vesicle trafficking and membrane fusion across eukaryotes. In pathogenic fungi, various SNARE homologs have been shown to critically regulate host infection processes. Here, we characterize the functional roles of [...] Read more.
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins play evolutionarily conserved roles in intracellular vesicle trafficking and membrane fusion across eukaryotes. In pathogenic fungi, various SNARE homologs have been shown to critically regulate host infection processes. Here, we characterize the functional roles of CfSec22 in the sweet potato black rot pathogen Ceratocystis fimbriata. Phylogenetic and domain analyses demonstrate that CfSec22 shares homology with Sec22 proteins from Saccharomyces cerevisiae (ScSec22), Magnaporthe oryzae (MoSec22), and other fungi, containing both the characteristic Longin homology domain and V-SNARE domain. Functional studies reveal that CfSec22 regulates growth, conidiation, and virulence of C. fimbriata. Deletion of CfSEC22 resulted in abnormal vacuole morphology and impaired endocytosis. The ΔCfsec22 mutant displayed heightened sensitivity to diverse stress conditions: oxidative, endoplasmic reticulum, and cell wall stressors. Subcellular localization studies confirmed the endoplasmic reticulum residence of CfSec22. Finally, we established that CfSec22 regulates the secretion of virulence-associated proteins and is required for the induction of ipomeamarone in infected sweet potato tissues. Together, our findings demonstrate that CfSec22-mediated vesicle trafficking serves as a critical regulatory mechanism supporting growth, conidiogenesis, and pathogenicity in C. fimbriata. Full article
(This article belongs to the Special Issue Feature Paper in Plant–Microbe Interactions in Asia)
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52 pages, 1456 KB  
Review
The Gut Microbiome in Enteric Viral Infections: Underlying Mechanisms and Therapeutic Approaches
by Alejandro Borrego-Ruiz and Juan J. Borrego
Microorganisms 2025, 13(10), 2247; https://doi.org/10.3390/microorganisms13102247 - 25 Sep 2025
Viewed by 1286
Abstract
Despite growing recognition of the role of the gut microbiome in host health and in modulating pathogen activity, the dynamic and reciprocal relationship between enteric viruses and the gut microbial ecosystem remains insufficiently defined and requires further exploration. This comprehensive review examines the [...] Read more.
Despite growing recognition of the role of the gut microbiome in host health and in modulating pathogen activity, the dynamic and reciprocal relationship between enteric viruses and the gut microbial ecosystem remains insufficiently defined and requires further exploration. This comprehensive review examines the bidirectional interplay between the gut microbiome and enteric viral infections by addressing (i) viruses associated with gastrointestinal alterations, (ii) how enteric viral infections alter the composition and function of the gut microbiome, (iii) how the gut microbiome modulates viral infectivity and host susceptibility, and (iv) current microbial-based approaches for preventing or treating enteric viral infections. Gastrointestinal viral infections induce gut microbiome dysbiosis, marked by reductions in beneficial bacteria and increases in potentially pathogenic populations. Specific gut microorganisms can modulate host susceptibility, with certain bacterial genera increasing or decreasing infection risk and disease severity. Pattern recognition receptors in the intestinal epithelium detect microbial signals and trigger antimicrobial peptides, mucus, and interferon responses to control viral replication while maintaining tolerance to commensal bacteria. The gut microbiome can indirectly facilitate viral infections by creating a tolerogenic environment, suppressing antiviral antibody responses, and modulating interferon signaling, or directly enhance viral replication by stabilizing virions, promoting host cell attachment, and facilitating coinfection and viral recombination. In turn, commensal gut bacteria can inhibit viral entry, enhance host antiviral responses, and strengthen mucosal barrier function, contributing to protection against gastrointestinal viral infections. Probiotics and fecal microbiota transplantation constitute potential microbial-based therapeutics that support antiviral defenses, preserve epithelial integrity, and restore microbial balance. In conclusion, the role of the gut microbiome in modulating enteric viral infections represents a promising area of future investigation. Therefore, integrating microbiome insights with virology and immunology could enable predictive and personalized strategies for prevention and treatment. Full article
(This article belongs to the Special Issue Microbiota and Gastrointestinal Diseases)
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19 pages, 2960 KB  
Article
Interaction Between Heparan Sulfate Oligosaccharide and the Receptor-Binding Domain of the Wild-Type and Omicron Variant of the SARS-CoV-2 Spike Protein
by Marco Mandalari, Michela Parafioriti, Minghong Ni, Francesca Benevelli, Monica Civera, Stefano Elli and Marco Guerrini
Biomolecules 2025, 15(9), 1343; https://doi.org/10.3390/biom15091343 - 19 Sep 2025
Viewed by 703
Abstract
Heparan sulfate proteoglycans serve as initial attachment sites for several viruses and bacteria. Recent studies suggest that SARS-CoV-2 similarly exploits these glycosaminoglycans, facilitating conformational changes in the spike protein that promote the interaction between the receptor-binding domain (S1-RBD) and the cellular angiotensin-converting enzyme [...] Read more.
Heparan sulfate proteoglycans serve as initial attachment sites for several viruses and bacteria. Recent studies suggest that SARS-CoV-2 similarly exploits these glycosaminoglycans, facilitating conformational changes in the spike protein that promote the interaction between the receptor-binding domain (S1-RBD) and the cellular angiotensin-converting enzyme 2 receptor (ACE2), thereby triggering the virus internalization process. The molecular details that drive this process, particularly the co-receptor role of heparan sulfate (HS), remain incompletely understood. The interaction between an HS hexasaccharide (hexa) and the N343 glycosylated S1-RBD of the wild-type (WT) and Omicron variant of SARS-CoV-2 was investigated. The conformational properties of hexa with these S1-RBDs in unbound and bound states are explored using multiple independent MD simulations; the protein binding epitope of hexa, as well as the details of its interaction with S1-RBD of the Omicron variant, are characterized by comparing experimental and theoretical 1H STD NMR signals. This investigation identifies the role played by the glycosyl moiety at N343 in potentially affecting this interaction in both WT and Omicron S1-RBD, explaining the observed low specificity and multi-modal nature of the interaction between HS oligosaccharides and these S1-RBDs. Full article
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10 pages, 1135 KB  
Article
A Bivalent Protease-Activated Receptor-Derived Peptide Mimics Neuronal Anti-Apoptotic Activity of Activated Protein C
by Abhay Sagare, Youbin Kim, Kassandra Kisler, Ruslan Rust, William J. Mack, José A. Fernández, Berislav V. Zlokovic and John H. Griffin
Bioengineering 2025, 12(9), 899; https://doi.org/10.3390/bioengineering12090899 - 22 Aug 2025
Viewed by 803
Abstract
Activated protein C (APC) exerts anticoagulant and cytoprotective cell signaling activities. APC’s cell signaling requires protease-activated receptor (PAR) PAR1 and PAR3, and APC’s PAR cleavages generate peptides capable of agonizing biased G-protein coupled receptor (GPCR) cytoprotective signaling, resulting in anti-inflammatory and anti-apoptotic activities [...] Read more.
Activated protein C (APC) exerts anticoagulant and cytoprotective cell signaling activities. APC’s cell signaling requires protease-activated receptor (PAR) PAR1 and PAR3, and APC’s PAR cleavages generate peptides capable of agonizing biased G-protein coupled receptor (GPCR) cytoprotective signaling, resulting in anti-inflammatory and anti-apoptotic activities and endothelial barrier stabilization. The PAR-sequence-derived 34-residue “G10 peptide” comprising PAR1 residues 47–55 covalently attached by a 10-glycine linker to PAR3 residues 51–65 is an orthosteric/allosteric bivalent GPCR agonist that potently mimics APC’s anti-inflammatory activity and endothelial barrier stabilization activity. The objective of this study was to determine whether the G10 peptide mimics APC’s anti-apoptotic activity using cultured murine neurons challenged by N-methyl-d-aspartate that provokes neuronal apoptosis. In these new studies, the G10 peptide mimicked APC’s anti-apoptotic activity. Thus, the PAR-derived 34-residue G10 peptide mimics APC’s three major cytoprotective activities, namely anti-inflammatory and anti-apoptotic activities and endothelial barrier stabilization. Peptides that agonize GPCRs provide promising and currently approved drugs; e.g., semaglutide and tirzepatide that contain 31 and 39 amino acid residues, respectively. Thus, this new study adds to the rationale for pursuing further studies of the G10 peptide for potential therapeutic value for multiple pathologies where APC or signaling-selective APC variants are therapeutic in preclinical animal studies. Full article
(This article belongs to the Section Biochemical Engineering)
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19 pages, 4709 KB  
Article
The Tetraspanin CD9 Facilitates SARS-CoV-2 Infection and Brings Together Different Host Proteins Involved in SARS-CoV-2 Attachment and Entry into Host Cells
by Vanessa Rivero, María Laura Saiz, Daniel Torralba, Carlos López-Larrea, Beatriz Suarez-Alvarez and Marta L. DeDiego
Viruses 2025, 17(8), 1141; https://doi.org/10.3390/v17081141 - 20 Aug 2025
Viewed by 3738
Abstract
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 [...] Read more.
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
(This article belongs to the Special Issue Coronaviruses Pathogenesis, Immunity, and Antivirals (2nd Edition))
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15 pages, 2817 KB  
Article
Dysfunction of Autophagy in Adipose Tissue Macrophages Regulated via FoxO1 in Obesity-Related Severe Acute Pancreatitis
by Xin Ling, Zewen Zhang, Lihui Lin, Xianwen Guo and Zhen Ding
Int. J. Mol. Sci. 2025, 26(15), 7206; https://doi.org/10.3390/ijms26157206 - 25 Jul 2025
Viewed by 656
Abstract
Adipose tissue macrophages (ATMs) play important roles in the progression of obesity-related severe acute pancreatitis (SAP). This study aimed to investigate the alterations of autophagic flux within ATMs, as well as the possible regulatory mechanisms. Obese mice were induced via high-fat diets. SAP [...] Read more.
Adipose tissue macrophages (ATMs) play important roles in the progression of obesity-related severe acute pancreatitis (SAP). This study aimed to investigate the alterations of autophagic flux within ATMs, as well as the possible regulatory mechanisms. Obese mice were induced via high-fat diets. SAP was triggered using caerulein and lipopolysaccharide. Inflammatory injuries within pancreatic and adipose tissue were assessed. Autophagic flux, along with the expression of autophagosome-located soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, were examined in ATMs. RNA-sequencing was performed to identify the possible regulatory factor, which was further validated. The results showed that obesity exacerbated inflammatory injuries. ATMs in obesity-related SAP exhibited impaired autophagic flux characterized by reduced autophagosome–lysosome fusion. Expression of autophagosome-located SNARE proteins decreased in ATMs. RNA-sequencing identified Forkhead box as the differentially expressed transcription factor associated with autophagy. The expression and transcriptional activity of Forkhead box O1 (FoxO1) decreased. The inhibition of FoxO1 exacerbated SNARE proteins’ suppression and autophagic flux impairment, while the activation of FoxO1 showed the opposite effect. In conclusion, obesity-induced impaired autophagic flux and autophagosome–lysosome fusion in ATMs are potentially regulated via autophagosome-located SNARE proteins and the transcription factor FoxO1. The impaired autophagic flux in ATMs aggravated inflammatory injuries of obesity-related SAP. Full article
(This article belongs to the Section Molecular Pathology, Diagnostics, and Therapeutics)
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26 pages, 24138 KB  
Review
Insights into the Landscape of Alphavirus Receptor and Antibody Interactions
by Shishir Poudyal, Abhishek Bandyopadhyay and Richard J. Kuhn
Viruses 2025, 17(7), 1019; https://doi.org/10.3390/v17071019 - 21 Jul 2025
Viewed by 1359
Abstract
Alphaviruses engage a diverse array of attachment factors and receptors during viral entry, resulting in a broad host range and disease spectrum, and thus presenting them as a major global public health concern. The development of effective antivirals against these arboviruses relies on [...] Read more.
Alphaviruses engage a diverse array of attachment factors and receptors during viral entry, resulting in a broad host range and disease spectrum, and thus presenting them as a major global public health concern. The development of effective antivirals against these arboviruses relies on a comprehensive understanding of the molecular interplay between these viruses and host cell factors, as well as the wide range of immune responses that ensue following viral infection. In this review, we present the current understanding of the complex landscape of alphavirus interaction with attachment factors and entry receptors, some of which are characterized structurally, while others are characterized biochemically. Additionally, we provide an overview of the molecular bases of epitope recognition by neutralizing and non-neutralizing antibodies against alphaviruses, and how icosahedral symmetry influences these interactions, such as occupancy and neutralization potency. We further discuss the structural bases of epitope recognition of a few pan-alphavirus antibodies, their potential therapeutic implications, and offer future perspectives on the development of effective therapeutics against clinically relevant alphaviruses. Full article
(This article belongs to the Special Issue 15-Year Anniversary of Viruses)
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19 pages, 3486 KB  
Article
3-O Sulfated Heparan Sulfate (G2) Peptide Ligand Impairs the Infectivity of Chlamydia muridarum
by Weronika Hanusiak, Purva Khodke, Jocelyn Mayen, Kennedy Van, Ira Sigar, Balbina J. Plotkin, Amber Kaminski, James Elste, Bajarang Vasant Kumbhar and Vaibhav Tiwari
Biomolecules 2025, 15(7), 999; https://doi.org/10.3390/biom15070999 - 12 Jul 2025
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Abstract
Background: Heparan sulfate (HS) is widely implicated as a receptor for Chlamydia cell attachment and infectivity. However, the enzymatic modification of HS modified by the 3-O sulfotransferase-3 (3-OST-3) enzyme in chlamydial cell entry remains unknown. Methodology: To rule out the possibility that host [...] Read more.
Background: Heparan sulfate (HS) is widely implicated as a receptor for Chlamydia cell attachment and infectivity. However, the enzymatic modification of HS modified by the 3-O sulfotransferase-3 (3-OST-3) enzyme in chlamydial cell entry remains unknown. Methodology: To rule out the possibility that host cell 3-O sulfated heparan sulfate (3-OS HS) plays a significant role in C. muridarum entry, a Chinese hamster ovary (CHO-K1) cell model lacking endogenous 3-OST-3 was used. In addition, we further tested the efficacy of the phage-display-derived cationic peptides recognizing heparan sulfate (G1 peptide) and the moieties of 3-O sulfated heparan sulfate (G2 peptide) against C. muridarum entry using human cervical adenocarcinoma (HeLa 229) and human vaginal epithelial (VK2/E6E7) cell lines. Furthermore, molecular dynamics simulations were conducted to investigate the interactions of the Chlamydia lipid bilayer membrane with the G1 and G2 peptides, focusing on their binding modes and affinities. Results: The converse effect of 3-OST-3 expression in the CHO-K1 cells had no enhancing effect on C. muridarum entry. The G2 peptide significantly (>80%) affected the cell infectivity of the elementary bodies (EBs) at all the tested concentrations, as evident from the reduced fluorescent staining in the number of inclusion bodies. The observed neutralization effect of G2 peptide on C. muridarum entry suggests the possibility of sulfated-like domains being present on the EBs. In addition, data generated from our in silico computational structural modeling indicated that the G2 peptide ligand had significant affinity towards the C. muridarum lipid bilayer. Conclusions: Taken together, our findings show that the pretreatment of C. muridarum with 3-O sulfated heparan sulfate recognizing G2 peptide significantly prevents the entry of EBs into host cells. Full article
(This article belongs to the Section Chemical Biology)
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