Asfia Soomro, Ifeanyi Kennedy Nmecha, Jackie Trink, Renzhong Li, Joan C Krepinsky
{"title":"Analysis of TGFβ1-Induced activin A gene expression in kidney mesangial cells.","authors":"Asfia Soomro, Ifeanyi Kennedy Nmecha, Jackie Trink, Renzhong Li, Joan C Krepinsky","doi":"10.3389/fmolb.2025.1607043","DOIUrl":"10.3389/fmolb.2025.1607043","url":null,"abstract":"<p><strong>Introduction: </strong>The cytokine activin A is emerging as an important regulator of kidney fibrosis. Its expression, negligible in normal kidney, is significantly increased in various fibrotic kidney diseases. TGFβ1 is a cytokine belonging to the same family, which is well established to be a central mediator of kidney fibrosis. Although targeting TGFβ1 therapeutically is not feasible due to its homeostatic roles, we previously showed that activin A is upregulated by, and mediates the profibrotic effects of, TGFβ1.</p><p><strong>Methods: </strong>We investigated the transcriptional regulation of activin A by TGFβ1 in primary kidney mesangial cells (MC). Cells were transfected with a luciferase reporter construct containing the activin A promoter or a series of deletion constructs. Guided by MatInspector, key TGFβ1-responsive consensus elements were identified.</p><p><strong>Results: </strong>TGFβ1 increased transcription of the activin A subunit <i>inhba</i>. Using a series of deletion constructs of the <i>inhba</i> promoter, we identified a critical regulatory region located 350bp from the transcription start site that is responsive to TGFβ1. Analysis of this region for transcription factor regulatory elements, coupled with mutation analyses and transcription factor downregulation with siRNA, showed that Stat5 and FoxP1, but not Sox9, regulate <i>inhba</i> transcription by TGFβ1. Interestingly, although no consensus binding site in this region was identified for Smad3, a well-established mediator of TGFβ1 signaling, both a Smad3 inhibitor and use of MC isolated from Smad3 knockout kidneys, showed its requirement for the TGFβ1 response. We further identified a CT microsatellite just upstream of 350bp which suppressed promoter activity.</p><p><strong>Conclusion: </strong>These findings provide insight into potential therapeutic targets for activin A targeting and attenuation of kidney fibrosis.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1607043"},"PeriodicalIF":3.9,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12500454/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145250650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unveiling the mechanistic nexus: how micronutrient enrichment shapes brain function, and cognitive health.","authors":"Siddhartha Das, Pradipta Banerjee, Sudipta Jana, Hemanshu Mondal","doi":"10.3389/fmolb.2025.1623547","DOIUrl":"10.3389/fmolb.2025.1623547","url":null,"abstract":"<p><p>Minerals, vitamins, and trace elements are examples of micronutrients essential for psychological wellbeing and brain function. Severe disorders may result from their deficiency or, conversely, from an excess of them. Recent studies have indicated that the etiopathogenesis of certain neurological disorders may involve chronically elevated micronutrient levels. Physiological functions, such as energy metabolism, neurotransmitter synthesis, and antioxidant defence, are regulated by these vital nutrients and are essential for optimal neuronal activity. According to new research, micronutrient enrichment, whether through diet or supplements, can have a significant impact on cognitive function, neuroplasticity, and brain development. Cognitive decline, memory loss, and attention problems are linked to deficiencies in essential micronutrients, including vitamin B12, iron, zinc, and omega-3 fatty acids. Tailored micronutrient therapies have shown promise in reducing age-related cognitive decline and enhancing mental function in both healthy individuals and those at greater risk. This manuscript emphasizes the growing research linking micronutrient status to cognitive health. It also highlights the importance of maintaining a balanced diet and following appropriate supplementation practices to optimize brain function throughout life.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1623547"},"PeriodicalIF":3.9,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12500463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145250611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fengyin Jiang, He Fei, Lina Yang, Rujun Chen, Liwen Zhang
{"title":"Integrated analysis and experimental validation of E2F2 as a potential prognostic biomarker and its oncogenic roles in serous ovarian cancer.","authors":"Fengyin Jiang, He Fei, Lina Yang, Rujun Chen, Liwen Zhang","doi":"10.3389/fmolb.2025.1661558","DOIUrl":"10.3389/fmolb.2025.1661558","url":null,"abstract":"<p><strong>Background: </strong>This study evaluated the prognostic role of E2F transcription factor 2 (E2F2) in serous ovarian cancers (SOCs) and explored its biological functions, immune cell infiltration links, and therapeutic implications.</p><p><strong>Methods: </strong>Integrating TCGA/Genotype-Tissue Expression (GTEx) data, we used bioinformatics tools (ssGSEA, Immunophenoscore, and oncoPredict) to analyze pathways and treatment responses. Validation involved RT-qPCR, Western blot analysis, cytotoxicity, and transwell assays.</p><p><strong>Results: </strong>E2F2 was upregulated in SOC tumors, correlating with poorer overall/disease-free survival and higher tumor grade. Five cell-cycle-related genes (<i>ORC1</i>, <i>RAD54L</i>, <i>CCNF</i>, <i>NCAPH</i>, and <i>HASPIN</i>) showed strong co-expression. A pathway analysis of 808 differentially expressed genes linked E2F2 to immune cell recruitment, including CD4<sup>+</sup> T cells, NK cells, and Tregs; low E2F2 levels were associated with higher immune scores. High E2F2 predicted sensitivity to chemotherapy/targeted therapy, while low E2F2 correlated with anti-CTLA4 responsiveness. <i>In vitro</i>, E2F2 promoted metastasis.</p><p><strong>Conclusion: </strong>High E2F2 expression marks poor prognosis and immune cell infiltration in SOCs and thus acts as an independent risk factor. It may serve as a potential biomarker for diagnosis, patient stratification, and guiding personalized therapy. Further research could enhance SOC management.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1661558"},"PeriodicalIF":3.9,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12501506/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145250683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bruna Eugênia de Freitas, Armanda Rodrigues, Joana Palma-Marques, Juliana Inês Weber, Ana Valério-Bolas, Rodrigo Pedro Soares, Ana Claudia Torrecilhas, Micheli Ferla, Munira Muhammad Abdel Baqui, Raul Alexander Gonzales Cordova, Graça Alexandre-Pires, Isabel Pereira da Fonseca, Hélida Monteiro de Andrade, Gabriela Santos-Gomes
{"title":"Unleashing the immune modulatory potential of <i>Leishmania amazonensis-</i>derived extracellular vesicles in American cutaneous leishmaniasis.","authors":"Bruna Eugênia de Freitas, Armanda Rodrigues, Joana Palma-Marques, Juliana Inês Weber, Ana Valério-Bolas, Rodrigo Pedro Soares, Ana Claudia Torrecilhas, Micheli Ferla, Munira Muhammad Abdel Baqui, Raul Alexander Gonzales Cordova, Graça Alexandre-Pires, Isabel Pereira da Fonseca, Hélida Monteiro de Andrade, Gabriela Santos-Gomes","doi":"10.3389/fmolb.2025.1593363","DOIUrl":"10.3389/fmolb.2025.1593363","url":null,"abstract":"<p><strong>Introduction: </strong>American cutaneous leishmaniasis (ACL) constitutes a neglected skin disease that causes severe disability and significant social stigma for millions of people each year. This parasitic infection is caused by several species of the protozoan <i>Leishmania</i>, including <i>Leishmania amazonensis</i>. There is therefore an urgent need to develop effective new tools to control ACL, primarily due to the limitations of current prophylactic and therapeutic strategies, which are exacerbated by the growing burden of the disease and its social impact. In recent years, scientific research has focused on extracellular vesicles (EVs), which are lipid-enclosed rounded nanostructures that carry macromolecules to recipient cells and are part of eukaryotic biology. The role of <i>Leishmania</i>-derived EVs in host pathogenesis has attracted considerable attention among researchers, with studies suggesting that EVs may play a key role in modulating the host immune response. Therefore, this study examined the immunogenicity and protein cargo of EVs shed by <i>L. amazonensis,</i> exploring their effect on immune activation in the murine macrophages (MΦs) lineage.</p><p><strong>Methods: </strong>Nanoparticle tracking analysis, microscopy, proteomic methodologies, colorimetric assays, serological immune methods, PCR, and multiparametric flow cytometry were employed.</p><p><strong>Results: </strong>EVs derived from <i>L. amazonensis</i> cultured promastigotes contain key components, such as the 63 kDa surface glycoprotein, intracellular heat shock protein 70, and α-type proteasome subunit, which may be involved in parasite survival. Moreover, EVs are recognized by mouse- and human-specific antibodies, indicating that they have the potential to elicit humoral immune responses and can be inactivated by host-specific antibodies. Depending on the concentration, EVs can drive MΦs to express MHC molecules that are essential for antigen presentation to T lymphocytes, thereby being able to promote a cellular immune response. EVs favor IL-1β<sup>+</sup>MΦs contraction, and low nitric oxide production, and activate the arginase pathway to produce urea along with the generation of proinflammatory cytokines. This MΦs modulation may support parasite control through the specific activation of T cells while preserving skin homeostasis, thereby reducing the pathology associated with <i>L. amazonensis</i> infection, which causes ACL and leads to the development of chronic disease.</p><p><strong>Discussion: </strong>Thus, this study's findings suggest that although <i>L. amazonensis</i>-derived EVs can trigger MΦs activation, favoring a pro-inflammatory immune response, they also have the potential to ensure parasite survival while limiting host pathogenesis. This can be advantageous for parasite transmission and essential for completing the parasite life cycle.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1593363"},"PeriodicalIF":3.9,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497982/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Post-translational modifications in heat stress-related diseases.","authors":"Qi Cui, Keran Jia, Fang Li, Jie Zheng, Fukun Wang","doi":"10.3389/fmolb.2025.1666874","DOIUrl":"10.3389/fmolb.2025.1666874","url":null,"abstract":"<p><p>Post-translational modifications (PTMs) act as pivotal molecular hubs integrating heat stress signals into cellular responses driving heat-related diseases like heatstroke. This review synthesizes evidence demonstrating that dynamic PTM networks-including phosphorylation, acetylation, ubiquitination, methylation, SUMOylation, and S-nitrosylation-orchestrate pathophysiology through three distinctive mechanisms: PTM crosstalk, tissue-specific PTM signatures defining organ vulnerability, and translational utility. The potentials of PTM alterations as novel biomarkers for early diagnosis/prognosis and PTM-targeted interventions as therapeutic strategies are discussed. By delineating how PTMs reconfigure proteostasis, metabolism, and inflammation, this review provides a mechanistic framework for targeting PTM pathways to mitigate heatstroke and related conditions.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1666874"},"PeriodicalIF":3.9,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12497517/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giacomo Zuccon, Aakriti Darnal, Edoardo Longo, Sara D'Aronco, Emanuele Boselli, Patrick Orlando, Alberto Ceccon
{"title":"Molecular mechanisms of amyloid inhibition: an NMR-driven framework with polyphenols as a case study.","authors":"Giacomo Zuccon, Aakriti Darnal, Edoardo Longo, Sara D'Aronco, Emanuele Boselli, Patrick Orlando, Alberto Ceccon","doi":"10.3389/fmolb.2025.1676927","DOIUrl":"10.3389/fmolb.2025.1676927","url":null,"abstract":"<p><p>Misfolding and aggregation of intrinsically disordered proteins into amyloid fibrils are central to neurodegenerative diseases such as Parkinson's, Alzheimer's, and Huntington's. Increasing evidence suggests that transient, low-populated oligomeric intermediates, rather than mature fibrils, are key cytotoxic species. Natural polyphenols have shown promise as amyloid inhibitors, though their mechanisms of action remain unclear due to the complexity of early aggregation. This perspective explores how solution-state NMR can quantitatively assess inhibitor mechanisms. Building on recent literature elucidating the aggregation mechanisms of the huntingtin exon 1 protein (htt<sup>ex1</sup>), responsible for Huntington's disease, we propose a kinetic framework that integrates early reversible oligomerization with downstream fibril formation and models the impact of small-molecule binding at distinct stages of the pathway. We show that monomer sequestration and inhibition of elongation-competent nuclei produce distinct aggregation profiles, resolvable through global fitting of NMR and kinetic data. This mechanistic insight enables classification of inhibitors by target stage-monomeric, oligomeric, or fibrillar-and demonstrates how polyphenols serve as a biologically relevant case study for applying this general NMR-driven framework to the design of small-molecule amyloid inhibitors.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1676927"},"PeriodicalIF":3.9,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12463619/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145185272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Atheer M Asiri, Daoud Ali, Nawal M Al-Malahi, Mohammed H A Almarzoug, Bader O Almutairi, Saad Alkahtani, Badr A Aldahmash, Saud Alarifi
{"title":"Eco-friendly production of silver-copper nanoparticles using coconut husk and evaluation of its anti-cancer properties on human breast cancer (MDA-MB-231) cell line.","authors":"Atheer M Asiri, Daoud Ali, Nawal M Al-Malahi, Mohammed H A Almarzoug, Bader O Almutairi, Saad Alkahtani, Badr A Aldahmash, Saud Alarifi","doi":"10.3389/fmolb.2025.1653312","DOIUrl":"10.3389/fmolb.2025.1653312","url":null,"abstract":"<p><p>The biological processes using green synthesis tool is safe, environmentally friendly, non-toxic, and economical, they are more suited to manufacturing nanoparticles with sizes between 1 and 100 nm than other related techniques. Here, I have used chemical methods to create bimetallic silver copper nanoparticles (Ag@CuNPs) utilizing coconut husk. Before exposure to target cells, the characterization of green silver copper nanoparticles (gAg@CuNPs) was done by UV vis spectrophotometer, scanning electron microscope (SEM), transmission electron microscopy (TEM), DLS. The shape of gAg@CuNPs are spherical and its size is measured 43.50 ± 1.5 nm. The cytotoxic effect of g Ag-Cu NPs on human breast cancer (MDA-MB-231) cells was determined by MTT and NRU tests. The cytotoxicity of gAg@CuNPs increased in a concentration-dependent manner and it showed high cytotoxic effect on MDA-MB-231 cells at the highest concentration of NPs exposure. From the MTT result I determined the median inhibitory concentration (IC<sub>50</sub>) for MDA-MB-231 cells at 24 h, which came out to be 66 μg/mL of NPs. Intracellular ROS levels was elevated at higher concentration of gAg@CuNPs. Superoxide dismutase (SOD) levels was increased at 33 μg/mL and it was reduced at 45 μg/mL. Glutathione (GSH) was reduced in MDA-MB-231 cells at high concentration of gAg@CuNPs. Using JC-1 staining, the loss of mitochondrial membrane potential in control, and gAg@CuNPs exposed cell were evaluated. In MDA-MB-231 cells, maximum apoptotic cells were observed at high concentration of NPs. Caspase-3/7 activity was increased in MDA-MB-231 cells at higher concentration of NPs. The above findings highlight the significance of gAg@CuNPs as cytotoxic agent brought on by oxidative stress, which frequently useful in a number of cancer treatments.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1653312"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12460125/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145185256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SRC is a potential target of Arctigenin in treating triple-negative breast cancer: based on machine learning algorithms, molecular modeling and <i>in Vitro</i> test.","authors":"Yuezhou Huang, Qing Luo, Linfeng Li, Tianping Li","doi":"10.3389/fmolb.2025.1644169","DOIUrl":"10.3389/fmolb.2025.1644169","url":null,"abstract":"<p><strong>Introduction: </strong>This research explores the therapeutic potential of Arctigenin (AG) against triple-negative breast cancer (TNBC) and elucidates its underlying molecular mechanisms.</p><p><strong>Methods: </strong>Potential targets of AG and TNBC-related genes were identified through public databases. By intersecting drug-specific and disease-related targets, key genes were selected for further analysis. Differential gene expression profiling and Weighted Gene Co-expression Network Analysis (WGCNA) were performed. Functional enrichment analysis was conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Machine learning algorithms were employed to identify hub genes, followed by validation through molecular docking, molecular dynamics (MD) simulations, and surface plasmon resonance (SPR) assays. In vitro experiments including cell viability assays, cell cycle analysis, apoptosis detection, and Western blotting were performed on MDA-MB-453 and MDA-MB-231 cell lines.</p><p><strong>Results: </strong>Our study identified 183 AG-related targets, 5,193 differentially expressed genes, and 6,173 co-expression module genes associated with TNBC. Machine learning algorithms pinpointed 4 hub genes from 28 intersecting targets. Molecular docking, Molecular dynamics (MD) and surface plasmon resonance (SPR) indicated a moderately strong interaction between AG and SRC kinase, where the oxygen atom of AG forms hydrogen bonds with the oxygen atom in M341 and the nitrogen atom in G344 of SRC. In vitro experiments confirmed that AG reduced the viability of MDA-MB-453 and MDA-MB-231 cells in a concentration-and time-dependent manner, leading S phase arrest and apoptosis. Western blotting indicated that AG significantly reduced the levels of Bcl-2, caspase-3, and caspase-9, as well as decreased SRC, p-PI3K-p85, p-AKT1, p-MEK1/2, and p-ERK1/2 expression in TNBC cells in a concentration dependent manner.</p><p><strong>Conclusion: </strong>AG exerts anti-TNBC effects by directly binding to SRC kinase, concurrently inhibiting both PI3K/AKT and MEK/ERK signaling pathways, ultimately leading to cell cycle arrest and apoptosis.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1644169"},"PeriodicalIF":3.9,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12460110/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145185288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Klaudia Dubniewicz, Laura Pardyak, Artur Gurgul, Igor Jasielczuk, Tomasz Szmatoła, Zbigniew J Arent
{"title":"Serovar-specific genomic features of <i>Leptospira interrogans</i> Hardjo: implications for host adaptation.","authors":"Klaudia Dubniewicz, Laura Pardyak, Artur Gurgul, Igor Jasielczuk, Tomasz Szmatoła, Zbigniew J Arent","doi":"10.3389/fmolb.2025.1648097","DOIUrl":"10.3389/fmolb.2025.1648097","url":null,"abstract":"<p><strong>Introduction: </strong>Leptospirosis, caused by <i>Leptospira</i> spp.<i>,</i> is one of the most widespread zoonoses worldwide. It affects both domestic and wild animals, with ruminants serving as a primary reservoir for serovar Hardjo. This serovar causes long-term colonisation of the kidney and genital tract. Hardjo strains are taxonomically assigned to two <i>Leptospira</i> species: <i>Leptospira interrogans</i> and <i>Leptospira borgpetersenii</i>. However, the molecular basis of <i>L. interrogans serovar</i> Hardjo adaptation remains poorly understood. Comparative genomic analysis of <i>L. interrogans</i> strains classified as the Hardjo serovar and other non-Hardjo serovars of the same species may help identify genetic determinants associated with host adaptation and species-specific cellular immune responses. Unfortunately, these pathogens are highly fastidious, and only a limited number of whole genomes have been sequenced to date.</p><p><strong>Materials and methods: </strong>Four <i>L. interrogans</i> serovar Hardjo European isolates were sequenced. Using these new sequences alongside publicly available genomes of <i>L. interrogans</i> strains classified as Hardjo and non-Hardjo serovars, we performed comparative genomic analyses.</p><p><strong>Results: </strong>Hardjo strains formed a distinct phylogenetic clade and harboured unique variants, including an intact <i>cas3</i> gene and a modified <i>thiM</i> start codon. We identified 88 Hardjo-specific orthologues, some located in putative genomic islands outside <i>rfb</i> locus. Several encoded proteins related to mobile elements, toxin-antitoxin systems or signal transduction. Enhanced biofilm formation in Hardjo strains supports a host-adapted phenotype.</p><p><strong>Conclusion: </strong>This study expands the genomic dataset for <i>L. interrogans</i> serovar Hardjo and provides novel insights into its genetic distinctiveness, suggesting potential factors that may facilitate colonisation and persistence in ruminant hosts.</p>","PeriodicalId":12465,"journal":{"name":"Frontiers in Molecular Biosciences","volume":"12 ","pages":"1648097"},"PeriodicalIF":3.9,"publicationDate":"2025-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12457778/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145148344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}