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Phosphoproteomic Profiling of Early-Stage Non-Small Cell Lung Cancer Provides Preliminary Evidence of Phosphorylation-Regulated Rho GTPase Signaling Driving Cytoskeletal Remodeling, Angiogenesis, and Cell Cycle Progression.

Non-small cell lung cancer (NSCLC) is the primary cause of cancer-related deaths worldwide. This can be attributed to the difficulty in early detection and the limited efficacy of available treatments, partly due to an incomplete understanding of the disease biology. Identification of key proteins involved in early-stage progression and understanding the underlying mechanisms can greatly contribute to the development of diagnostic and treatment strategies for NSCLC. Quantitative phosphoproteomic analysis was done on paired tumor tissues and adjacent normal lung tissues from early-stage NSCLC adenocarcinoma (LUAD) patients to allow for the identification of proteins with differential phosphorylation and their associated pathways. A total of 6483 phosphoproteins were identified, with 1229 proteins having significantly higher phosphorylation and 701 proteins having significantly lower phosphorylation in the tumor tissues. All MS data were deposited in ProteomeXchange with the identifier PXD071583. Function enrichment analysis showed that the differentially phosphorylated proteins and phosphosites were primarily involved in Rho GTPase signaling and cytoskeleton remodeling. Analysis of protein interaction networks suggests that the predicted kinase activity likely drives malignant transformation in NSCLC LUAD, presumably through Rho GTPase-mediated angiogenesis and cell cycle progression. More importantly, this study identified several protein phosphosites with differential phosphorylation and inferred kinase-phosphosite activities that have not previously been reported in NSCLC LUAD.

Humans

Serum Proteomic Profiling Reveals Renin-Associated Immune and Cytoskeletal Dysregulation in Post-COVID-19 Condition Patients with Secondary Adrenal Insufficiency.

Post-COVID-19 condition (PCC) with secondary adrenal insufficiency (SAI) involves multiorgan dysfunction, potentially linked to renin-angiotensin-aldosterone system dysregulation. The molecular basis of renin-associated pathology remains unclear. Here, PCC+SAI patients were stratified by upright renin into low- (<38.8&#x202f;pg/mL) and high-renin (&#x2265;38.8&#x202f;pg/mL) groups. Clinical, endocrine, and proteomic analyses were performed. We found that high-renin patients showed increased BMI, lipids, renin, and aldosterone, but reduced aldosterone-to-renin ratio. Proteomic annalysis identified 20 differentially expressed proteins (DEPs), including 17 upregulated and 3 downregulated proteins in Ren-H patients. Functional annotation revealed that 15 DEPs were immune-related (e.g., APOC4, APOE, C4BPA, CFAH, CFHR3, PF4V, PLF4), while FLNA and COF1 represented cytoskeletal proteins. These DEPs were primarily involved in immune response, complement and coagulation cascades, and MAPK signaling pathways. Correlation analyses indicated that upright renin was positively correlated with complement-related proteins and platelet-derived immune factors, while cytoskeletal proteins (FLNA, COF1) showed positive associations with serum Na+ levels. Additionally, white blood cell and platelet counts were positively correlated with the majority of DEPs. In conclusion, exploratory proteomic analyses suggest that elevated upright renin in PCC+SAI may be associated with immune dysregulation, complement activation, and cytoskeletal remodeling, offering novel insights into the endocrine-immune interactions driving postviral sequelae.

Humans

Nap1-mediated actin remodeling is essential for mammalian myoblast fusion.

Myoblast fusion is crucial for the formation, growth, maintenance and regeneration of healthy skeletal muscle. Unfortunately, the molecular machinery, cell behaviors, and membrane and cytoskeletal remodeling events that govern fusion and myofiber formation remain poorly understood. Using time-lapse imaging approaches on mouse C2C12 myoblasts, we identify discrete and specific molecular events at myoblast membranes during fusion and myotube formation. These events include rearrangement of cell shape from fibroblast to spindle-like morphologies, changes in lamellipodial and filopodial extensions during different periods of differentiation, and changes in membrane alignment and organization during fusion. We find that actin-cytoskeleton remodeling is crucial for these events: pharmacological inhibition of F-actin polymerization leads to decreased lamellipodial and filopodial extensions and to reduced myoblast fusion. Additionally, shRNA-mediated inhibition of Nap1, a member of the WAVE actin-remodeling complex, results in accumulations of F-actin structures at the plasma membrane that are concomitant with a decrease in myoblast fusion. Our data highlight distinct and essential roles for actin cytoskeleton remodeling during mammalian myoblast fusion, provide a platform for cellular and molecular dissection of the fusion process, and suggest a functional conservation of Nap1-regulated actin-cytoskeleton remodeling during myoblast fusion between mammals and Drosophila.

Actins

Exploring the proteomic landscape of THP-1 monocytes through two-challenge LPS induction.

Proteome remodelling is central to the regulation of innate immune activation, yet the temporal organisation of protein networks engaged during repeated lipopolysaccharide (LPS) stimulation remains incompletely defined. In the present study, label-free quantitative mass spectrometry-based proteomics was used to characterise protein abundance changes in THP-1 monocytes at early (30&#xa0;min) and later (2&#xa0;h) time points following a second LPS challenge. This analysis was complemented by an independent co-immunoprecipitation proteomics experiment designed to identify candidate proteins associated with the regulatory pseudo-kinase IRAK3 during early TLR4 signalling. At 30&#xa0;min, differentially abundant proteins were enriched in pathways associated with pattern-recognition receptor signalling, NF-&#x3ba;B activity, RNA processing, phosphorylation, and ribonucleoprotein complex organisation. By 2&#xa0;h, the proteomic response broadened to include oxidative phosphorylation, antigen processing and presentation, vesicle-mediated transport, protein folding, and cytokine-regulatory pathways. These findings indicate that repeated LPS stimulation is accompanied by progressive remodelling of inflammatory, metabolic, translational, and proteostatic programmes rather than major changes in protein identity. Co-immunoprecipitation identified established TLR/IRAK3-associated components together with candidate IRAK3-associated proteins linked to RNA regulation, kinase signalling, ubiquitin-mediated processes, redox control, cytoskeletal remodelling, and damage-associated molecular pattern responses. Collectively, these findings define a temporal framework of proteomic adaptation during repeated inflammatory stimulation and expand the range of candidate proteins potentially contributing to IRAK3-centred regulation of innate immune signalling.

Humans

Role of semaphorin 4f in cardiac fibroblasts to regulate matrix production through actin remodeling and YAP/TAZ activation.

Cardiac fibrosis remains a critical determinant of adverse outcomes in heart disease, yet effective anti-fibrotic therapies are lacking. While multiple semaphorin family members participate in cardiovascular pathophysiology, the role of semaphorin 4f (Sema4f) in cardiac fibrosis remains unexplored. This study investigates the role and mechanisms of Sema4f in fibrotic remodeling post-myocardial infarction (MI). We employed flow cytometry to characterize cell type-specific Sema4f expression patterns in post-MI hearts. Lineage-specific knockout mice (fibroblast vs. myeloid) were subjected to left anterior descending ligation to assess functional consequences. Proteomic analysis of Sema4f-deficient cardiac fibroblasts was conducted to identify downstream effectors. Key pathways were subsequently validated using pharmacological inhibitors. We found that Sema4f expression was markedly upregulated during the fibrotic phase post-MI, primarily due to fibroblast activation. Fibroblast-, but not myeloid-, specific Sema4f deletion significantly reduced fibrosis and improved cardiac function. Proteomic profiling revealed that Sema4f deficiency led to downregulation of pro-fibrotic gene expression, which was associated with impaired actin cytoskeletal remodeling and decreased nuclear translocation of YAP/TAZ. Pharmacological inhibition of either actin remodeling or YAP/TAZ activity attenuated fibrosis, whereas YAP/TAZ activation abolished the anti-fibrotic effects of Sema4f knockout. Our study provides the first evidence demonstrating the functional role of Sema4f in cardiac fibroblast activation and fibrosis progression. We have identified a fibroblast-specific mechanism mediated by the Sema4f-actin cytoskeleton-YAP/TAZ axis, offering novel mechanistic insights into fibrosis regulation and revealing a promising therapeutic target for cardiac fibrosis with potential clinical applications.

Animals

Bovine Colostrum-Derived Extracellular Vesicles Impair Cancer Cell Proliferation Through Transcriptional Dysregulation.

Milk-derived extracellular vesicles (EVs) are a promising source of molecules with therapeutic potential. Bovine colostrum is particularly enriched in EVs, which carry cargo of proteins involved in immune regulation, development and cellular signalling. Some studies have explored their role as bioactive anti-cancer agents, however, their mechanistic effects remain underexplored. Here, we show that colostrum-derived EVs (Col-EVs) exert anti-proliferative effects in gastrointestinal cancer models, including cell lines and patient-derived organoids, which is independent of apoptosis induction. Using a multi-modal approach combining proteomics, imaging and functional assays, we demonstrate that Col-EVs induce a reversible growth-arrest state, characterized by widespread transcriptional and RNA-processing dysregulation, chromatin compaction, nuclear reorganization and cytoskeletal remodelling. Proteomic analyses reveal that Col-EV treatment disrupts key components of the transcriptional machinery and cell cycle regulatory pathways, effects that are reversible upon EV withdrawal and can be rescued pharmacologically using an EZH2 inhibitor. Col-EVs enhance the sensitivity of cancer cells as well to DNA-targeting chemotherapies such as 5-fluorouracil, indicating their potential as modulatory adjuvants rather than cytotoxic agents. Overall, our findings reveal that Col-EVs can reversibly suppress cancer cell proliferation by reprogramming transcriptional and nuclear architecture, offering a natural, biocompatible strategy for modulating tumour growth and sensitizing cancer cells to conventional therapies.

Extracellular Vesicles

Bioinformatic analysis reveals the potential association of ESRP1 with the splicing of cytoskeleton-associated genes in doxorubicin-resistant MCF7 breast cancer cells.

BACKGROUND: Breast cancer remains one of the most prevalent malignancies among women, with doxorubicin resistance posing a significant challenge that undermines treatment success and survival outcomes. Aberrant alternative splicing (AS), driven by dysregulation or mutations in splicing factors (SFs), is implicated in cancer initiation, progression, and drug resistance. This study aims to investigate the association of the epithelial cell-specific splicing factor ESRP1 with doxorubicin resistance in breast cancer, focusing on how ESRP1 deficiency correlates with AS changes that promote chemoresistance. METHODS: We analyzed RNA-sequencing (RNA-seq) data from doxorubicin-resistant (MCF7-DR) and parental (MCF7) breast cancer cell lines to identify enhanced alternative splicing events (ASEs) and changes in ESRP1 expression; we further leveraged The Cancer Genome Atlas (TCGA)-BRCA cohort to construct an SF-RASE correlation network for screening core SFs (including ESRP1). An integrative analysis combining crosslinking immunoprecipitation (CLIP-seq) data and The Cancer Genome Atlas (TCGA) database was performed to validate ESRP1 binding targets and assess the association between ESRP1-related splicing and cytoskeleton organization. RESULTS: We observed extensive AS changes and significantly downregulated ESRP1 expression in MCF7-DR cells. Integrative analysis identified 61 high-confidence ASEs that correlate with ESRP1 expression. Further bioinformatic integration suggests that ESRP1 expression is associated with the splicing patterns of SPTBN1, MAP2K7, FGFR3, and CYB561A3-four genes involved in cytoskeleton organization-though direct experimental verification to confirm a causal regulatory relationship between ESRP1 and the splicing of these genes is still pending. CONCLUSIONS: Our findings suggest that ESRP1 expression is closely associated with doxorubicin resistance in breast cancer cells, with concomitant alterations in key ASEs linked to cytoskeletal remodeling that correlate with ESRP1. Exploring the ESRP1-related splicing network may offer new strategies to overcome chemoresistance and improve patient outcomes. However, the small cell line sample size (n&#x2009;=&#x2009;2 per group) constrains the robustness of ASE and SF-ASE correlation findings, and these results should be interpreted with caution and require further validation with larger sample cohorts.

Alternative splicing

Comparative transcriptomic analysis of the gills and hepatopancreas of freshwater-cultured Litopenaeus vannamei under chronic nitrite stress.

To investigate the differences in molecular responses between the gills and hepatopancreas of freshwater-cultured Litopenaeus vannamei under chronic nitrite stress, a 30-day chronic stress experiment was conducted with a control group and a stress group. Transcriptomic analysis of the gills and hepatopancreas was performed using Illumina sequencing; differentially expressed genes (DEGs) were identified, and GO, KEGG, GSEA, PPI, and RT-qPCR validation were carried out. The results showed that 196 DEGs (161 up-regulated and 35 down-regulated) were identified in the gills, and 287 DEGs (199 up-regulated and 88 down-regulated) in the hepatopancreas, with only 18 DEGs shared between the two tissues. DEGs in the gills were enriched in oxidoreductase activity, glycerophospholipid metabolism, and tyrosine metabolism; DEGs in the hepatopancreas were enriched in lipid transporter activity, phagosome, ECM-receptor interaction, and riboflavin metabolism. GSEA revealed significant suppression of the mTOR pathway in the gills and the Polycomb complex pathway in the hepatopancreas. PPI network analysis identified hub genes P5CS and eEF2 in the gills, and PER, TUBB1, SHMT, and TUBB4B in the hepatopancreas. RT-qPCR validation was consistent with the RNA-seq results (R2&#xa0;=&#xa0;0.764). This study indicates that, under chronic nitrite stress, the gill response is centered on redox regulation and inhibition of growth metabolism, whereas the hepatopancreas response primarily involves lipid transport, cytoskeletal remodeling, and phagosome activation. The two tissues synergistically adapt through fundamental biosynthetic and motor protein pathways. This research provides molecular evidence for deciphering the nitrite tolerance mechanisms in freshwater-cultured shrimp.

Animals

Low-salinity stress alters growth, histology, physiology, and transcriptomic profiles of the gills and antennal glands in Macrobrachium rosenbergii.

Salinity is a major abiotic constraint in freshwater aquaculture of the giant freshwater prawn Macrobrachium rosenbergii, yet the coordinated roles of the gills and antennal glands, the two primary osmoregulatory organs in decapod crustaceans, under low-salinity stress remain poorly characterized. Here, we integrated histological, physiological, and transcriptomic analyses to characterize the adaptive responses of M. rosenbergii to acute (96&#xa0;h) and chronic (8&#xa0;weeks) exposure to salinity 5. Chronic low-salinity stress significantly impaired growth performance and decreased the survival rate. Acute stress induced thinning of the gill filaments, partial disorganization of pillar cells, and dilation of the intermicrovillar space in the antennal glands, whereas chronic stress caused gill vacuolization, cuticle thinning, and adaptive folding of antennal gland microvilli. In parallel, acute exposure significantly decreased hemolymph sodium and potassium ion concentrations but increased magnesium ion concentration, whereas chronic exposure increased hemolymph sodium and potassium ion concentrations, upregulated gill Na+/K+-ATPase activity, and enhanced hepatopancreatic antioxidant capacity. Transcriptomic analyses revealed distinct tissue-specific responses. Under acute stress, the gills preferentially activated pathways associated with cytoskeletal remodeling, motor proteins, and tight junctions, whereas chronic acclimation shifted the transcriptional response toward the renin-angiotensin system and glutathione metabolism. In the antennal glands, acute stress rapidly activated the renin secretion pathway, whereas chronic exposure promoted membrane remodeling by enriching pathways related to lipid and glycan metabolism. These findings reveal tissue-specific functional differentiation and synergistic coordination between the gills and antennal glands that underpin M. rosenbergii's adaptive response to low-salinity stress.

Animals

Evaluation of pilocarpine effects on sweat proteome.

BACKGROUND: Sweat is increasingly recognized as a valuable, non-invasive biofluid for biomarker discovery, yet its composition depends on the stimulation method. This study aimed to determine how pharmacological induction with pilocarpine compares to physiologically induced sweat through exercise in shaping the sweat proteome. RESULTS: We analyzed thermoregulatory sweat from exercise, pilocarpine-induced sweat, and combined pilocarpine plus exercise sweat. Total protein concentrations were similar across conditions, but pilocarpine markedly increased proteomic diversity, with combined pilocarpine plus exercise sweat showing the highest number of identifications. The core sweat proteome remained stable, while pilocarpine selectively enriched low-abundance proteins involved in vesicular trafficking, cytoskeletal remodelling, and metabolism. Proteins linked to the canonical M3-Gq-PLC-Ca2+ pathway, including AQP5, CALML5, and CLIC1, were consistently enriched, confirming cholinergic activation. Pilocarpine-induced sweat also contained plasma-derived and immune-related proteins, reflecting enhanced secretion and reduced ductal reabsorption. CONCLUSIONS: Exercise yields a physiologically relevant but less complex proteome, pilocarpine-induced sweat produces a pharmacologically enriched yet biased profile, and combined pilocarpine plus exercise sweat maximizes protein detection at the expense of interpretability. These findings highlight the critical impact of stimulation paradigm on sweat proteomics and provide a reference framework for biomarker research. SIGNIFICANCE: This study employed LC-MS/MS to systematically characterize eccrine sweat and delineate how stimulation paradigms-exercise, pilocarpine, and their combination-shape its proteomic landscape. By demonstrating that pharmacological induction profoundly alters protein diversity and composition compared to physiologically induced sweat, these findings establish a critical benchmark for sweat-based biomarker research and highlight the need for paradigm-aware sampling strategies in clinical and translational contexts. Nonetheless, several methodological constraints warrant consideration: the limited sample size (five individuals per group), the exclusive inclusion of women under combined oral contraceptive treatment (21 active pills followed by 7 pill-free days), which restricts extrapolation to naturally cycling women, and the focus on healthy young adults (18-25&#xa0;years), limiting generalizability to older or clinically heterogeneous populations. Despite these limitations, this work provides a foundational framework for optimizing sweat collection protocols and advancing precision approaches in non-invasive diagnostics.

Pilocarpine

Newly identified invasion drivers define the tumor front in oral squamous cell carcinoma.

Cells at the invasive front of oral squamous cell carcinoma (OSCC) occupy a partial epithelial-to-mesenchymal transition (p-EMT) state that drives invasion and therapeutic resistance yet remains poorly understood. To define the regulators of this metastable state, we developed an isogenic OSCC model that captures stable epithelial and p-EMT phenotypes and used it to perform a genome-wide CRISPR invasion screen. This unbiased strategy identified 17 modulators of invasion, most previously unrecognized in cancer and virtually unexplored in OSCC, that converge on cytoskeletal remodeling, adhesion, and epigenetic regulation. Within this network, EDIL3 emerged as a central driver of EMT, invasion, and chemoresistance in head and neck cancer, extending prior reports in other tumor types. Importantly, the invasion signature derived from our screen localized with striking specificity to the tumor invasive front of human OSCC, providing direct clinical validation. Together, these findings reveal a novel, targetable network of transient invasion drivers defining the OSCC tumor front.

Journal Article

Biocontrol potential and molecular basis of predation in a marine raptorial ciliate.

Predator-prey interactions are widespread across organisms and are key drivers of morphological and behavioral evolution. Despite this, predation remains poorly understood among microbial eukaryotes, mostly due to the absence of a tractable experimental system that allows quantitative, reproducible investigation. This study establishes the marine raptorial ciliate Chaenea vorax as a highly efficient predator, with Rosenzweig-MacArthur model simulations based on predation data showing that only a few dozen individuals can eliminate the vast majority of the facultatively pathogenic ciliate Uronema marinum within 1-2&#xa0;days, providing a quantitative basis for developing predator-based biocontrol strategies in aquaculture. Genomic analysis shows that C. vorax possesses a highly fragmented macronuclear genome enriched with predation-related pathways, including calcium-mediated contractility, cellular proteolysis, toxin expulsion systems, among others. Transcriptomic profiling during predation events further demonstrates significant upregulation of genes involved in cytoskeletal remodeling, proteolytic activity, and cellular detoxification. Evolutionary analyses suggest that C. vorax has an extremely long evolutionary history, exceptionally high nucleotide diversity even among ciliates, and gene family expansions linked to predatory adaptation. Although the prey possesses certain defensive mechanisms (e.g. trichocysts), these are largely ineffective against short-term predation in closed aquatic environments. These findings provide fundamental insights into the molecular basis of predation in ciliates and suggest the potential utility of C. vorax in biocontrol applications targeting pathogenic ciliates.

Ciliophora

Proteomic signatures of adipocyte recruitment in breast cancer.

The tumor microenvironment (TME) is increasingly recognized as a dynamic regulator of breast cancer progression, with adipocytes functioning as active contributors rather than passive bystanders. Here, we investigated the proteomic and morphologic reprogramming of breast cancer-associated adipocytes (BrCAAs) in response to triple-negative breast cancer (TNBC). Using conditioned medium from HCC1143 cells, we established an in vitro BrCAA model and performed mass spectrometry-based proteomics. Comparative profiling revealed 256 differentially expressed proteins, enriched for pathways including fatty acid degradation, carbon metabolism, and glycogen turnover, consistent with a metabolic shift from energy storage to energy supply. Gene ontology and protein-protein interaction analyses further identified cytoskeletal remodeling, adhesion dynamics, and secretory pathway activation, supporting BrCAA-driven microenvironmental remodeling. In the MMTV-PyMT mouse model, morphometric analysis demonstrated progressive size reduction and increased contour irregularity of adipocytes adjacent to tumors, correlating with proteomic evidence of metabolic stress. Importantly, BrCAAs localized at tumor interfaces were associated with increased microvessel density and CD105+ endothelial activation compared to desmoplastic zones. Proteomic enrichment highlighted pro-angiogenic remodeling, with validation of basigin (BSG), integrin &#x3b1;V (ITGAV), and 2,4-dienoyl-CoA reductase 1 (DECR1). Collectively, our findings establish BrCAAs as metabolically and structurally reprogrammed stromal components that promote tumor metabolism and localized angiogenesis, representing potential therapeutic targets in aggressive breast cancer.

Female

PIP3 antagonist as a molecular regulator in MSC-derived cardiomyocytes: Potential in vitro therapeutic implications for conotruncal heart defects.

Conotruncal heart defects (CTDs) account for approximately one-third of all congenital heart defects. Elevated levels of phosphatidylinositol (3,4,5)-trisphosphate (PIP3) may contribute to CTD pathogenesis. PIP3 plays a pivotal role in mechanotransduction-based biological processes and remodeling of cardiac cytoskeletal proteins. Here, we aimed to evaluate the efficacy of the 322PESB derivative compound as a molecular regulator that antagonizes PIP3 binding pleckstrin homology (PH) domain of the Akt protein using mesenchymal stem cell-derived cardiomyocyte. Human adipose-derived MSCs (Ad-MSCs) were isolated. Immunophenotypic features of the hAd-MSCs were characterized according to minimal criteria of the international society for cellular therapy (ISCT) including immunophenotyping and trilineage differentiation potential. Subsequently, the differentiated hAd-MSCs were cultured in cardiomyogenesis-inducing medium. Successfully differentiated cardiomyocytes were assessed by measuring the expression levels of cardiomyocyte-specific genes using RT-qPCR. PIP3-primed cardiomyocytes were treated with 10 and 30&#xa0;&#x3bc;mol/L of a 322PESB derivative molecule. The results showed a typical MSCs with high expression levels of CD73 (77.55%), CD90 (87.59%) and CD105 (91.88%) and that was accompanied by low expression levels of CD34 (0.59%) and CD45 (1.78%). After 21&#xa0;days of MSC culture, cardiomyocyte-like cells with prominent striations were observed. Subsequent confirmation by RT-qPCR quantification of ADRB1 and MLC2a expression levels showed an average increase of 2.9-fold and 2.1-fold, respectively, in induced cardiomyocytes. Compared with the untreated control, PIP3 ELISA assay showed a significant increase in PIP3 levels in PIP3(10&#xa0;nmol/L)-primed cardiomyocytes treated with 10 and 30&#xa0;&#x3bc;mol/L of the 322PESB molecule derivative by 485.804 and 3564.164&#xa0;ng/mL, respectively. In this study, we conducted the first promising molecular regulator with potential therapeutic implications for CTD patients. Further functional animal model and clinical phase studies are recommended.

Cardiomyocyte

Integrative WGBS and ATAC-seq profiling reveals epigenetic and chromatin accessibility signatures associated with clutch length in goose ovaries.

Clutch length is an important reproductive trait in geese, but its epigenetic basis remains poorly characterized. Daily egg production was recorded for 280 individually housed Zi geese, and clutch-related indices were calculated as described in our previous study. Based on these records, six geese with contrasting clutch-length phenotypes were selected and assigned to the long-clutch (LC) and short-clutch (SC) groups. Ovarian tissues from three geese per group were subjected to whole-genome bisulfite sequencing (WGBS) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) to identify candidate epigenetic signatures associated with clutch length. WGBS identified 630,909 differentially methylated regions (DMRs), whereas ATAC-seq identified 902 differentially accessible regions (DARs). Integrated analysis revealed distinct patterns of ovarian DNA methylation and chromatin accessibility between the two groups, suggesting that clutch length variation may be accompanied by epigenomic differences in ovarian tissue. Genes associated with DMRs and/or DARs were enriched in biological processes related to granulosa cell differentiation and endocrine competence, follicular fate regulation, and periovulatory cytoskeletal and signaling remodeling. RERE was prioritized as a candidate locus because it was supported by changes in both DNA methylation and chromatin accessibility, whereas FOXL2, STAR, BAK1, FGF17, PRSS35, ACTR3, and AXIN1 were supported mainly by evidence from a single omics layer. RT-qPCR analysis of selected genes showed expression trends broadly consistent with the corresponding epigenomic differences, providing additional supportive evidence for these candidate associations. Collectively, this study provides an exploratory ovarian epigenomic resource and identifies candidate epigenetic signatures, genes, and biological processes associated with clutch length variation in geese.

DNA methylation

Cytoskeletal mechanisms regulating attaching/effacing bacteria interactions with host cells: It takes a village to build the pedestal.

The actin cytoskeleton is a key cellular structure subverted by pathogens to infect and survive in or on host cells. Several pathogenic strains of Escherichia coli, such as enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC), developed a unique mechanism to remodel the actin cytoskeleton that involves the assembly of actin filament-rich pedestals beneath the bacterial attachment sites. Actin pedestal assembly is driven by bacterial effectors injected into the host cells, and this structure is important for EPEC and EHEC colonization. While the interplay between bacterial effectors and the actin polymerization machinery of host cells is well-understood, how other mechanisms of actin filament remodelling regulate pedestal assembly and bacterial attachment are poorly investigated. This review discusses the gaps in our understanding of the complexity of the actin cytoskeletal remodelling during EPEC and EHEC infection. We describe possible roles of actin depolymerizing, crosslinking and motor proteins in pedestal dynamics, and bacterial interactions with the host cells. We also discuss the biological significance of pedestal assembly for bacterial infection.

Humans

Proximity interactome of alphavirus replicase component nsP3 includes proviral host factors eIF4G and AHNAK.

All positive-strand RNA viruses replicate their genomes in association with modified intracellular membranes, inducing either membrane invaginations termed spherules, or double-membrane vesicles. Alphaviruses encode four non-structural proteins nsP1-nsP4, all of which are essential for RNA replication and spherule formation. To understand the host factors associated with the replication complex, we fused the efficient biotin ligase miniTurbo with Semliki Forest virus (SFV) nsP3, which is located on the cytoplasmic surface of the spherules. We characterized the proximal proteome of nsP3 in three cell lines, including cells unable to form stress granules, and identified >300 host proteins constituting the microenvironment of nsP3. These included all the nsPs, as well as several previously characterized nsP3 binding proteins. However, the majority of the identified interactors had no previously identified roles in alphavirus replication, including 39 of the top 50 interacting proteins. The most prominent biological processes involving the proximal proteins were nucleic acid metabolism, translational regulation, cytoskeletal rearrangement and membrane remodeling. siRNA silencing confirmed six novel proviral factors, USP10, AHNAK, eIF4G1, SH3GL1, XAB2 and ANKRD17, which are associated with distinct cellular functions. All of these except SH3GL1 were also important for the replication of chikungunya virus. We discovered that the small molecule 4E1RCat, which inhibits the interaction between the canonical translation initiation factors eIF4G and eIF4E, exhibits antiviral activity against SFV. Since the same molecule was previously found to inhibit coronaviruses, this suggest the possibility that translation initiation factors could be considered as targets for broadly acting antivirals.

Viral Nonstructural Proteins

Activation of Rac1 by shear stress in endothelial cells mediates both cytoskeletal reorganization and effects on gene expression.

Hemodynamic shear stress is a fundamental determinant of vascular remodeling and atherogenesis. Changes in focal adhesions, cytoskeletal organization and gene expression are major responses of endothelial cells to shear stress. Here, we show that activation of the small GTPase Rac is essential for gene expression and for providing spatial information for shear stress-induced cell alignment. Fluorescence resonance energy transfer (FRET) localizes activated Rac1 in the direction of flow. This directional Rac1 activation is downstream of shear-induced new integrin binding to extracellular matrix. Additionally, Rac1 mediates flow-induced stimulation of nuclear factor kappaB (NF-kappaB) and the subsequent expression of intercellular cell adhesion molecule 1 (ICAM-1), an adhesion receptor involved in the recruitment of leukocytes to atherosclerotic plaque. These studies provide a unifying model linking three of the main responses to shear stress that mediate both normal adaptation to hemodynamic forces and inflammatory dysfunction of endothelial cells in atherosclerosis.

Animals