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Cell-specific DNA methylation in human alpha and beta cells regulates gene expression in type 2 diabetes.

Epigenome-wide studies of pancreatic islets provide valuable insights into type 2 diabetes (T2D) but lack methylomes from individual cell types. Here we show changes to alpha and beta cell-specific methylomes and transcriptomes from people with or without T2D, using whole-genome bisulfite sequencing and RNA sequencing. We discover 22,544 differentially methylated regions annotated to 7,975 genes in alpha versus beta cells, such as INS, GCG, PDX1 and PCSK1, with ~50% showing differential expression. CRISPR-dCas9-DNMT3A-based epigenetic editing increases INS and TH DNA methylation, while CRISPR-dCas9-TET1-based editing decreases GCG methylation, each altering INS, TH or GCG expression and content in beta cells. Pre-T2D/T2D-associated differentially methylated regions in alpha and beta cells overlap 12-18% of T2D-associated genome-wide association study candidates. Additionally, ONECUT2 is epigenetically upregulated in beta cells from people with pre-T2D/T2D and elevated in male Goto-Kakizaki rat islets. ONECUT2 overexpression in beta cells/islets downregulates gene sets impacting insulin secretion and glucose homeostasis, and reduces mitochondrial activity, ATP/ADP ratio and insulin secretion. We also provide 'alpha-beta-methylome' ( https://alpha-beta-methylome.serve.scilifelab.se/app/alpha-beta-methylome/ ), a resource exploring T2D, age and sex associations on methylation, highlighting cell-specific epigenetic regulation and dysfunctions contributing to T2D.

Humans↗

Transcriptome analysis reveals specific modulation of abscisic acid signaling by ROP10 small GTPase in Arabidopsis.

Abscisic acid (ABA) is a hormone that modulates a variety of agronomically important growth and developmental processes and various stresses responses, but its signal transduction pathways remain poorly understood. ROP10, a member of ROP small GTPases in Arabidopsis (Arabidopsis thaliana), is a plasma membrane-associated protein specifically involved in negative regulation of ABA responses. To dissect the ROP10-mediated ABA signaling, we carried out transcriptome analysis using the Arabidopsis full-genome chip. Our analysis revealed a total of 262 and 125 genes that were, respectively, up- and down-regulated (> or =2-fold cutoff) by 1 mum ABA in wild type (Wassilewskija [Ws]); 42 up-regulated and 38 down-regulated genes have not been identified in other studies. Consistent with the nonpleiotropic phenotypes of rop10-1, only three genes were altered in rop10-1 in the absence of ABA treatment. In response to 1 microm ABA, 341 and 127 genes were, respectively, activated and repressed in rop10-1. Interestingly, a particular subset of 21 genes that were not altered by 1 microm ABA in Ws but only activated in rop10-1 was identified. Reverse transcription-polymerase chain reaction analysis revealed the existence of three distinct categories of ABA dose-response patterns. One novel category is characterized by their ABA unresponsiveness in Ws and activation in rop10-1 at 1 microm but not 10 and 100 microm of ABA. This indicates that ROP10 gates the expression of genes that are specific to low concentrations of ABA. Furthermore, almost all of these 21 genes are known to be highly induced by various biotic and abiotic stresses. Consequently, we found that rop10-1 enhanced the sensitivity of seed germination inhibition to mannitol and sodium chloride. Our results suggest that ROP10 negatively regulates ABA responses by specifically and differentially modulating the ABA sensitivity of a subset of genes including protein kinases and zinc-finger family proteins.

Abscisic Acid↗

Transcriptome Analysis, Machine Learning, and Experimental Identification of CDK7 Affecting the Progression of Pregnancy-induced Hypertension by Influencing Macrophage Polarization.

INTRODUCTION: Pregnancy-induced hypertension (PIH) is a severe pregnancy complication characterized by placental insufficiency, abnormal vascular remodeling, and immune dysregulation, but personalized therapeutic markers remain unclear. This study aimed to identify key genes and explore immune mechanisms in PIH using transcriptome analysis, machine learning, and experimental validation. METHODS: We analyzed the GSE204835 transcriptomic dataset to screen differentially expressed genes (DEGs) and performed Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and Gene Set Enrichment Analysis (GSEA) for functional annotation. Immune infiltration analysis was also performed to examine the immune landscape in PIH. Least Absolute Shrinkage and Selection Operator (LASSO) regression identified key genes, which were validated in a PIH cell model. Flow cytometry and immunofluorescence assays assessed the effect of CDK7 knockdown on macrophage polarization. RESULTS: A total of 1,598 DEGs (1,123 upregulated, 475 downregulated) were identified. Enrichment analyses highlighted associations with embryonic organ development, oxidative phosphorylation, angiogenesis, and oxidative stress. Immune infiltration analysis revealed altered eosinophil and macrophage polarization in PIH. LASSO regression selected 12 key genes, with CDK7 showing the most significant upregulation in the PIH model. CDK7 knockdown promoted macrophage polarization toward the anti-inflammatory M2 phenotype. DISCUSSION: These findings link CDK7 to immune dysregulation in PIH by modulating macrophage polarization, expanding our understanding of PIH's molecular mechanisms. The study's limitations include reliance on public datasets and in vitro models, warranting in vivo validation. CONCLUSION: CDK7 emerges as a potential therapeutic target for PIH, offering new insights into immunoregulatory interventions for this complication.

Female↗

Temporal Transcriptomic Profiling of NMBA-Induced Rat Esophageal Squamous Carcinogenesis Identifies Early Inflammatory Activation and Late NRF2-Associated Oxidative-Stress Remodeling.

Temporal molecular events during early esophageal squamous carcinogenesis remain incompletely defined, in part because human precursor tissues are difficult to obtain sequentially. We used the N-nitrosomethylbenzylamine (NMBA)-induced rat model to characterize stage-associated transcriptional programs during esophageal squamous carcinogenesis. Vehicle-control reference esophageal tissues and NMBA-treated esophageal tissues, collected at weeks 6 and 29, were profiled using Affymetrix Rat Genome 230 2.0 arrays, followed by pathway analysis and qRT-PCR validation of selected genes. Relative to vehicle-control reference tissues, 173 genes were differentially expressed at week 6, whereas 1628 genes were differentially expressed at week 29, indicating marked expansion of transcriptional dysregulation during carcinogenic progression. Sixteen genes were differentially expressed only at week 6, while 157 genes were altered at both time points. Pathway analysis suggested that inflammatory and immunologic processes were prominent during the early response to NMBA exposure, whereas late-stage carcinogenesis was characterized by NRF2-associated oxidative-stress response and dysregulation of multiple glutathione S-transferase family members. A subset of progression-associated genes, including Defb4, Gsta2, Sbsn, Spink5, Plcd4, Hbb, and Hba-a2, showed increasing dysregulation from week 6 to week 29. These findings define temporally distinct molecular programs in NMBA-induced esophageal squamous carcinogenesis and provide a framework for prioritizing candidate pathways and genes relevant to esophageal cancer prevention, early detection, and progression biology.

Animals↗

ACE2 and Parkinsonism‑related bone metabolic alterations: signaling pathways and hub gene analysis.

Clinical co-occurrence of Parkinson's disease (PD) and age-related bone loss in elderly patients has garnered increasing attention, yet its molecular mechanisms remain incompletely elucidated. This study used an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD model in Ace2-/y mice to investigate the regulatory mechanisms of bone-brain axis-related genes and signaling pathways. Behavioral tests assessed motor and non-motor symptoms. Immunohistochemistry, Western blot, and histopathological staining analyzed dopaminergic neuron activity, microglial activation, and bone metabolic abnormalities. GEO dataset transcriptomics and weighted gene co-expression network analysis (WGCNA) identified key hub genes, with receiver operating characteristic (ROC) curves evaluating their diagnostic value in public single-disease transcriptome data. MPTP significantly exacerbated motor dysfunction and depression-like behaviors; Ace2 deletion lowered total Wnt, β-catenin, BMP and IGF-1 protein abundance alongside reduced phosphorylation ratios of their downstream kinases in brain and bone, while upregulating RANKL/RANK/OPG-associated inflammatory mediators, accompanied by elevated total α-synuclein, Casp3 and Bax protein levels. The parallel reduction of these signaling proteins only suggests potential perturbation of related cascades; WGCNA identified 10 hub genes (e.g., DNM1, OCRL, OPA1), whose dysregulation was linked to synaptic dysfunction and inflammation. ROC analysis based on single-disease datasets showed high diagnostic accuracy for PD and `osteoporosis (OP) (AUC: 0.683-0.981), with core genes influencing synaptic, MAPK, Rap1, and Ras pathways. These preclinical findings indicate that Ace2 deficiency is associated with concurrent pathological abnormalities in the brain and transient bone metabolic disturbance under short-term MPTP treatment in growing young male mice; coordinated dysregulation of shared signaling pathways was observed in the two tissues, consistent with a potential bone-brain axis pathological phenotype, though causal bidirectional tissue cross-talk cannot be confirmed in the current experimental design, providing candidate targets that warrant further validation.

Animals↗

Leveraging the genetics of psychiatric disorders to prioritize potential drug targets and compounds.

Genetics can inform biologically relevant drug development and repurposing, which may improve patient care. Here, we leverage the genetics of psychiatric disorders to prioritize potential drug targets and compounds. We used the genome-wide association studies of four psychiatric disorders [attention deficit hyperactivity disorder (ADHD), bipolar disorder, depression, and schizophrenia] and genes encoding drug targets. We conducted drug enrichment analyses incorporating the novel and biologically specific GSA-MiXeR tool. We conducted multiple molecular trait analyses using large-scale transcriptomic and proteomic datasets sampled from brain and blood tissue. This included the novel use of the UK Biobank proteomic data for a proteome-wide association study of psychiatric disorders. With the accumulated evidence, we prioritize potential drug targets and compounds for each disorder. We reveal candidate drug targets associated with a single or multiple disorders that implicate glutamate signaling. Drug prioritization indicated genetic support for psychotropic medications, including several top-ranked antipsychotics for schizophrenia. We also observed genetic support for commonly used psychotropics for psychiatric treatment (e.g., clozapine, duloxetine, and lithium). Revealed opportunities for drug repurposing included cholinergic drugs for ADHD, estrogen modulators for depression, and matrix metalloproteinases for ADHD and depression. Our findings indicate the genetic liability to schizophrenia is associated with reduced brain and blood expression of CYP2D6, a gene encoding a metabolizer of drugs and neurotransmitters, suggesting a genetic risk for poor drug response and altered neurotransmission. Our extensive analyses highlight the utility of genetics for informing drug development and repurposing for psychiatric disorders, providing novel opportunities for improving patient outcomes. Depicted is the series of analyses conducted to generate a list of prioritized drug targets and compounds. First pairings of genome-wide association study (GWAS) traits with drugs are generated using enrichment analyses. Next, a series of molecular trait analyses is conducted to generate and rank a list of potential drug targets for each GWAS trait. Finally, enrichment and molecular trait results are combined to generate a ranked list of prioritized drugs for each GWAS trait based on supporting genetic evidence. ADHD = Attention deficit hyperactivity disorder, BIP = Bipolar disorder, DEP = Depression, SCZ = Schizophrenia, DBP = Diastolic blood pressure, T2D = Type 2 diabetes, RNA = ribonucleic acid, XWAS = both transcriptome and proteome-wide association studies, MR = Mendelian randomization, coloc = colocalization.

Humans↗

Transcriptome analysis reveals mechanisms by which Lactococcus lactis acquires nisin resistance.

Nisin, a posttranslationally modified antimicrobial peptide produced by Lactococcus lactis, is widely used as a food preservative. Yet, the mechanisms leading to the development of nisin resistance in bacteria are poorly understood. We used whole-genome DNA microarrays of L. lactis IL1403 to identify the factors underlying acquired nisin resistance mechanisms. The transcriptomes of L. lactis IL1403 and L. lactis IL1403 Nis(r), which reached a 75-fold higher nisin resistance level, were compared. Differential expression was observed in genes encoding proteins that are involved in cell wall biosynthesis, energy metabolism, fatty acid and phospholipid metabolism, regulatory functions, and metal and/or peptide transport and binding. These results were further substantiated by showing that several knockout and overexpression mutants of these genes had strongly altered nisin resistance levels and that some knockout strains could no longer become resistant to the same level of nisin as that of the wild-type strain. The acquired nisin resistance mechanism in L. lactis is complex, involving various different mechanisms. The four major mechanisms are (i) preventing nisin from reaching the cytoplasmic membrane, (ii) reducing the acidity of the extracellular medium, thereby stimulating the binding of nisin to the cell wall, (iii) preventing the insertion of nisin into the membrane, and (iv) possibly transporting nisin across the membrane or extruding nisin out of the membrane.

Anti-Bacterial Agents↗

Comparison of basal gene expression profiles and effects of hepatocarcinogens on gene expression in cultured primary human hepatocytes and HepG2 cells.

Toxicogenomics is a relatively new discipline of toxicology. Microarrays and bioinformatics tools are being used successfully to understand the effects of toxicants on in vivo and in vitro model systems, and to gain a better understanding of the relevance of in vitro models commonly used in toxicological studies. In this study, cDNA filter arrays were used to determine the basal expression patterns of human cultured primary hepatocytes from different male donors; compare the gene expression profile of HepG2 to that of primary hepatocytes; and analyze the effects of three genotoxic hepatocarcinogens; aflatoxin B(1) (AFB(1)), 2-acetylaminofluorene (2AAF), and dimethylnitrosamine (DMN), as well as one non-gentoxic hepatotoxin, acetaminophen (APAP) on gene expression in both in vitro systems. Real-time PCR was used to verify differential gene expression for selected genes. Of the approximately 31,000 genes screened, 3-6% were expressed in primary hepatocytes cultured on matrigel for 16 h. Of these genes, 867 were expressed in cultured hepatocytes from all donors. HepG2 cells expressed about 98% of the genes detectable in cultured primary hepatocytes, however, 31% of the HepG2 transcriptome was unique to the cell line. A number of these genes are expressed in human liver but expression is apparently lost during culture. There was considerable variability in the response to chemical carcinogen exposure in primary hepatocytes from different donors. The transcription factors, E2F1 and ID1 mRNA were increased three-fold and six-fold (P < 0.05, P < 0.01), respectively, in AFB(1) treated primary human hepatocytes but were not altered in HepG2. ID1 expression was also increased by dimethylnitrosamine, acetylaminofluorene and acetaminophen in both primary hepatocytes and HepG2. Identification of genes that are expressed in primary hepatocytes from most donors, as well as those genes with variable expression, will aid in understanding the variability in human reactions to drugs and chemicals. This study suggests that identification of biomarkers of exposure to some chemicals may be possible in the human through microarray analysis, despite the variability in responses.

Carcinogens↗

DNA oligonucleotide microarray technology identifies fisp-12 among other potential fibrogenic genes following murine unilateral ureteral obstruction (UUO): modulation during epithelial-mesenchymal transition.

BACKGROUND: Tubulointerstitial inflammation and fibrosis are pathologic hallmarks of end-stage renal disease (ESRD). Here we have used DNA microarray technology to monitor the transcriptomic responses to murine unilateral ureteral obstruction (UUO) with a view to identifying molecular modulators of tubulointerstitial fibrosis. METHODS: Using Affymetrix Mu74Av2 microarrays, gene expression 4 and 10 days postobstruction was investigated relative to control contralateral kidneys. Candidate profibrogenic genes were further investigated in epithelial cells undergoing epithelial to mesenchymal transition (EMT) in vitro. RESULTS: mRNA levels for 1091 gene/EST sequences, of a total of 12,488 displayed on the microarray, were altered twofold or greater by days 4 and 10 postobstruction compared to contralateral control kidneys. Genes were categorised into functional groups, including modulators of cytoskeletal and extracellular matrix metabolism, cell growth, signalling, and transcription/translational events. Among the potentially profibrogenic genes, whose mRNA levels were increased after UUO, were fibroblast-inducible secreted protein (fisp-12), the murine homologue of connective tissue growth factor (CTGF), collagen XVIIIalpha1, secreted protein acidic and rich in cysteine (SPARC), and src-suppressed C-kinase substrate (SSeCKS). A sustained increase in fisp-12 mRNA level was observed during EMT induced by transforming growth factor-beta1 (TGF-beta1) and epidermal growth factor (EGF). CONCLUSION: Altered gene expression in murine UUO has been demonstrated. Increased expression of fisp-12, SPARC, and SSeCKS has been shown in response to TGF-beta1 treatment and during EMT, suggesting that these genes may offer potential therapeutic targets against tubulointerstitial fibrosis.

A Kinase Anchor Proteins↗

Decoding tumor immune microenvironment heterogeneity by single-cell and spatial multi-omics: From immunotherapy resistance to translational biomarkers.

Immune checkpoint blockade has transformed cancer therapy, yet primary and acquired resistance remain major clinical challenges. Increasing evidence indicates that immunotherapy resistance cannot be fully explained by tumor-intrinsic alterations or conventional biomarkers such as PD-L1 expression, tumor mutational burden, or microsatellite instability. Instead, therapeutic response is shaped by the tumor immune microenvironment (TIME) as a heterogeneous, spatially organized, and dynamically evolving ecosystem. Single-cell omics has revealed diverse immune and stromal cell states, including progenitor and terminally exhausted T cells, suppressive myeloid programs, B-cell/TLS-associated immune-reactive states, and CAF-mediated exclusion phenotypes. Spatial transcriptomics, spatial proteomics, and imaging-based approaches further demonstrate that these cell states assemble into distinct immune niches, including immune-inflamed, T-cell-excluded, myeloid-suppressive, metabolic/hypoxic, and TLS-associated niches. These spatial ecosystems determine whether antitumor immune cells can access malignant cells, receive antigen-presenting support, or become restrained by stromal, vascular, metabolic, and myeloid barriers. In this review, we summarize how single-cell and spatial multi-omics redefine TIME heterogeneity in immunotherapy resistance, highlight ligand-receptor communication networks linking cell states to spatial immune dysfunction, and discuss emerging translational biomarkers for patient stratification. We further propose that future immunotherapy biomarkers should evolve from static single-marker assays toward longitudinal, spatially resolved, and interpretable multi-omics models that guide precision combination immunotherapy.

Humans↗

Molecular and Genomic Mechanisms Linking Diabetes Mellitus and Periodontitis: From Pathogenesis to Translational Opportunities.

Diabetes mellitus and periodontitis are bidirectionally associated chronic disorders linked through metabolic dysregulation, host inflammation, microbial dysbiosis, and impaired tissue remodeling. This review summarizes clinical, molecular, cellular, genomic, epigenomic, transcriptomic, and microbial evidence concerning the mechanisms underlying this relationship and their potential translational relevance. Chronic hyperglycemia is associated with advanced glycation end product signaling through the receptor for advanced glycation end products, mitogen-activated protein kinase/nuclear factor-&#x3ba;B activation, reactive oxygen species production, oxidative stress, and NLR family pyrin domain-containing 3 inflammasome activation, which may contribute to enhanced cytokine responses and periodontal tissue injury. Diabetes is also associated with altered neutrophil and macrophage function, increased T helper 17/interleukin-17 signaling, and an elevated receptor activator of nuclear factor-&#x3ba;B ligand/osteoprotegerin ratio, thereby favoring osteoclastogenesis and alveolar bone loss. Conversely, periodontal inflammation and microbial products may contribute to systemic low-grade inflammation, insulin resistance, and metabolic dysregulation. Multi-omics studies have identified shared susceptibility loci, regulatory networks, and disease-associated cell states, although their causal and clinical significance remains incompletely defined. These findings suggest potential roles for integrated medical-dental care, glycemic screening in dental settings, periodontal inflammation control, host-modulatory therapies, and regenerative biomaterials. Further longitudinal and experimental studies are needed to determine their clinical applicability.

Humans↗

Genome-wide analysis of the endothelial transcriptome under short-term chronic hypoxia.

We have utilized serial analysis of gene expression (SAGE) to analyze the temporal response of human aortic endothelial cells (HAECs) to short-term chronic hypoxia at the level of transcription. Primary cultures of HAECs were exposed to 1% O2 hypoxia for 8 and 24 h and compared with identical same passage cells cultured under standard (5% CO2-95% air) conditions. A total of 121,446 tags representing 37,096 unique tags were sequenced and genes whose expression levels were modulated by hypoxia identified by novel statistical analyses. Hierarchical clustering of genes displaying statistically significant hypoxia-responsive alterations in expression revealed temporal modulation of a number of major functional gene families including those encoding heat shock factors, glycolytic enzymes, extracellular matrix factors, cytoskeletal factors, apoptotic factors, cell cycle regulators and angiogenic factors. Within these families we documented the coordinated modulation of both previously known hypoxia-responsive genes, numerous genes whose expressions have not been previously shown to be altered by hypoxia, tags matching uncharacterized UniGene entries and entirely novel tags with no UniGene match. These preliminary data, which indicate a reduction in cell cycle progression, elevated metabolic stress and increased cytoskeletal remodeling under acute hypoxic stress, provide a foundation for further analyses of the molecular mechanisms underlying the endothelial response to short-term chronic hypoxia.

Aorta↗

Transcriptional response to the neuroleptic-like compound Ampullosporin A in the rat ketamine model.

Psychotic disorders affecting up to 1% of the human population represent pathological changes to the metabolic homeostasis of the brain. Increasing evidence in the literature suggests complex biochemical and/or transcriptional alterations accompanying schizophrenia-like phenomena. Sub-chronic treatment with sub-anaesthetic doses of ketamine induces schizophrenia-related psychotic alterations that can be used as an animal model in the study of this disorder. Ampullosporin A belongs to a specific group of pore-forming fungal peptides, peptaibols. We focused on the analysis of molecular events occurring in the brain of ketamine-pre-treated rats after administration of Ampullosporin A with neuroleptic-like activity. The complex experimental approach allowed us to correlate the use of low molecular weight substances with a transcriptome fingerprint in the prefrontal cortex. We found 63 genes to be up-regulated and 22 genes suppressed, with transthyretin, syndecan-1 and NeuroD1 showing the highest degree of up-regulation. Our results suggest the possibility that Ampullosporin A belongs to the group of neuroleptic-like compounds, inducing massive changes in neurotransmitter receptor composition, calcium signalling cascades and second messenger systems, and leading to the plastic reorganization of brain tissue, metabolic pathways and synapses.

Animals↗

An integrated study of acute effects of valproic acid in the liver using metabonomics, proteomics, and transcriptomics platforms.

An integrated omics approach was undertaken in order to elucidate a systems biology level understanding of the acute hepatotoxcity of valproic acid (VPA). Metabonomics, proteomics and gene expression microarray platforms were employed in this systems biology study. CD-1 female pregnant mice were injected subcutaneously with 600 mg/kg VPA or vehicle control. Urine, serum, and liver tissue were collected at 6, 12, and 24 h after dosing. Principal component analysis (PCA) of the metabonomics data showed clustering of the dosed groups away from the controls for the urine samples. Looser clustering was seen in the other sample sets investigated. However, VPA administration resulted in altered glucose concentrations in urine samples at 12 and 24 h and in aqueous liver tissue extracts at 12 h after VPA administration. Proteomics studies identified two proteins, glycogen phosphorylase and amylo-1,6-glucosidase, which were increased in dosed animals relative to control. Both of these proteins are involved in converting glycogen to glucose. Examination of the expression of 20,000 liver genes did not reveal significantly altered expression at 6, 12, or 24 h after VPA exposure. The combined studies indicated a perturbation in the glycogenolysis pathway following administration of VPA.

Animals↗

The skeletal muscle of aged male mice exhibits sustained growth regulatory transcriptional profile following glucocorticoid exposure compared with young males.

Excess glucocorticoids induce skeletal muscle myopathy by changing gene expression. Advanced age augments glucocorticoid-mediated muscle phenotypes, yet the transcriptional responses underlying those augmented phenotypes are unclear. The purpose of this study was to define the glucocorticoid-responsive transcriptome in young and aged muscle following both acute and more prolonged glucocorticoid treatment. Young (4-mo-old) or aged (24-mo-old) male mice were administered either an acute injection of dexamethasone (DEX) or vehicle or daily DEX or vehicle injections for 7 days. Muscles were harvested 6.5 h after the final or only injection. The tibialis anterior (TA) was selected for RNA sequencing analysis as DEX treatment lowered TA mass specifically in aged males. In silico analyses identified enriched pathways and transcription factors predicted to regulate DEX-sensitive genes. Acute DEX altered similar numbers of genes in young (950) versus aged males (913), although aged males had greater magnitudes of fold change. After 7 days of DEX treatment, aged muscle exhibited more DEGs compared with acute exposure (1,196 vs. 913), whereas young muscle exhibited fewer DEGs than after acute exposure (599 vs. 950). In aged males, glucocorticoid-sensitive genes were consistently enriched for growth regulatory processes across both time points, a pattern that was not evident in young males. Despite those age-associated transcriptional differences, the transcription factors predicted to regulate the glucocorticoid-sensitive genes were similar in young and aged males. These data expand our understanding into how aging modifies the transcriptional response to excess glucocorticoids in skeletal muscle.NEW & NOTEWORTHY Glucocorticoids promote mass loss in certain muscles with advanced age but not at younger ages. In a muscle whose mass is lost in response to elevated glucocorticoids only in advanced age in males, we show that glucocorticoids initiate a unique and exaggerated transcriptional profile after both acute exposure to the hormone and after prolonged treatment that is consistent with muscle atrophy. These findings expand our understanding of the effect primary aging has on glucocorticoid-induced atrophy in males.

Animals↗

Fecal microbiota transplantation promotes type 2 mucosal immune responses with colonic epithelium proliferation in patients with recurrent Clostridioides difficile.

BACKGROUNDFecal microbiota transplantation (FMT) is the most effective therapy for recurrent Clostridioides difficile infection (rCDI), yet its mechanism of action remains poorly understood.METHODSWe report the results of a clinical trial of patients undergoing FMT therapy for rCDI (n = 16), which analyzed colon biopsies, plasma, PBMCs, and stool at the time of FMT and 2-month follow-up. Plasma and colon biopsy samples were also collected from healthy controls for comparison with patients with rCDI. Microbiome composition, colonic gene expression, and immune changes were evaluated through high-throughput sequencing and immunoprofiling via flow cytometry.RESULTSNo patients experienced recurrence at follow-up. FMT significantly altered the intestinal microbiome but had no significant impact on the systemic immune system. In contrast, FMT promoted broad changes in colonic transcriptional profiles compared with both pre-FMT and healthy control biopsies, inhibiting genes associated with proinflammatory signaling and upregulating type 2 immunity and proliferative pathways (Myc and mTORC1). FMT increased expression of IL-33 and the type 2 immune EGFR family ligand amphiregulin, potentially explaining upregulation of Myc and mTORC1 pathways. Spatial transcriptomics demonstrated that these changes were localized to the colonic epithelium. Comparison of transcriptional profiles with available single-cell gene sets determined that post-FMT biopsies were enriched in signatures associated with proliferative cell types while repressing signatures of differentiated colonocytes.CONCLUSIONWe conclude that FMT promotes proliferation of the colonic epithelium in patients with rCDI, which may drive regeneration and protect against subsequent CDI.TRIAL REGISTRATIONClinicaltrials.gov NCT02797288.FUNDINGThis work was funded by grants from the NIH.

Adult↗

Dnmt3b and Dnmt3l knockdown reduces blastocyst development in early mouse embryos.

A one-cell embryo called a zygote develops into a blastocyst through several successive cell divisions and lineage specification, this process is called early embryo development. Both embryonic genome activation (EGA) and the first lineage specification during early embryonic development depend on tightly coordinated epigenomic organization. Regulation of the epigenome is primarily governed by DNA methylation mediated through DNA methyltransferase (Dnmt) enzymes. Dnmt1 is responsible for the maintenance of methylation during cellular division, while Dnmt3a/Dnmt3b enzymes play a role in the establishment of de novo methylation particularly during gametogenesis and early embryo development. Despite its lack of catalytic activity, Dnmt3l functions as a cofactor enhancing Dnmt3a/3b activity. Dnmt3b deficiency results in global hypomethylation and ultimately embryonic lethality. In this study, we aim to elucidate the effect of Dnmt3b and Dnmt3l silencing on early embryo development. For this purpose, our experimental groups were established using an in vitro mouse embryo development model: control, Dnmt3b small interfering RNA (siRNA), Dnmt3l siRNA, and a nontargeting siRNA group. Following gene silencing at the one-cell stage, embryonic developmental competence, the expression pattern of nonsilenced Dnmt enzymes, global DNA methylation levels, and transcriptome profiles were analyzed at the blastocyst stage. Dnmt3b/3l silencing resulted in decreased global DNA methylation and Dnmt1/3a expression, and reduced blastocyst rate. Differentially expressed genes included those involved in X-chromosome inactivation (Xist), transcriptional regulation (Rn7sk), translation (Eef1a1, Eef2), trophoblast development (Hsd3b1), compaction (Gja1), and oxidative phosphorylation (CYTB, COX1, mt-Rnr1). Our findings indicate that siRNA-mediated knockdown of Dnmt3b and Dnmt3l is associated with reduced blastocyst development, impaired embryo quality, and alterations in DNA methylation-related processes during early embryonic development.

Animals↗

Strain dependence of the cell wall-damage induced stimulon in Staphylococcus aureus.

The vancomycin stress induced transcriptome of the methicillin susceptible Staphylococcus aureus (MSSA) strain Newman was determined by microarray analysis. Subsets of the induced ORFs corresponded to those previously reported to be induced by vancomycin in the methicillin resistant S. aureus (MRSA) strains N315 and JH1, and/or by other cell wall active antibiotics in RN450; while other ORFs appeared to be induced strain specifically in Newman. Northern analyses showed that the induction pathway for several of the ORFs appeared to be altered in a number of clinical NARSA isolates. Induction was found to be dependent on inhibitory concentrations of antibiotics.

Bacterial Proteins↗