Background: Sepsis involves profound immune and metabolic disturbances. This study investigated whether prophylactic short-chain fatty acid (SCFA) supplementation alters circulating immunometabolic biomarkers and biochemical markers of hepatic and renal injury in experimental sepsis.Methods: Male Wistar rats were assigned to four groups (n = 12/group) with independent 24-h and 48-h subgroups. Sepsis was induced by cecal ligation and puncture (CLP). A mixture of sodium acetate, propionate, and butyrate (60:20:20 molar ratio; total dose 500 mg/kg) was administered intraperitoneally for 7 days before CLP and discontinued after sepsis induction. Circulating immunometabolic and organ-injury-related markers were measured.Results: SCFA supplementation increased circulating G protein-coupled receptor 41 (GPR41)- and G protein-coupled receptor 43 (GPR43)-related marker concentrations and produced an overall increase in glucagon-like peptide-1 (GLP-1). Angiopoietin-like protein 4 (ANGPTL4) increased significantly in septic animals at both time points, whereas C1q/tumor necrosis factor-related protein 3 (CTRP3) was not significantly altered by SCFA supplementation within septic animals. Circulating NOD-like receptor family pyrin domain-containing protein 3 (NLRP3)-related marker concentrations were reduced at 24 h and 48 h, while NLRP6-related marker concentrations were reduced at 48 h. SCFA supplementation also reduced alanine aminotransferase (ALT), urea, and creatinine at both time points and aspartate aminotransferase (AST) at 48 h. Other adipokine and metabolic marker responses were marker- and time-dependent.Conclusion: Prophylactic SCFA supplementation was associated with changes in circulating immunometabolic biomarkers and reductions in biochemical markers of hepatic and renal injury in CLP-induced sepsis. These findings require further tissue-based and therapeutic investigation.
Background: Rheumatoid arthritis (RA), an autoimmune condition, causes fibroblast-like synoviocytes (FLSs) growth, joint inflammation, and erosion. Methotrexate (MTX), the principal treatment for this illness, has an unknown mechanism. We investigated the potential regulatory mechanism of MTX in RA-related synovial fibroblasts, focusing on whether MTX exerts therapeutic effects via regulating N6-methyladenosine (m6A) modification mediated by methyltransferase like 3 (METTL3), which affects the expression of the key purine metabolism enzyme 5-Aminoimidazole-4-Carboxamide Ribonucleotide Formyltransferase/IMP Cyclohydrolase (ATIC).Methods: The effects of MTX on RA-FLSs proliferation, migration, invasion, cell cycle distribution and apoptosis were assessed using methylthiazolyldiphenyl-tetrazolium bromide (MTT), Transwell assays and flow cytometry. METTL3 and ATIC protein levels were quantified by Western blotting. Functional rescue experiments were performed using METTL3-overexpressing cells, while the underlying molecular mechanism was investigated by methylated RNA immunoprecipitation (MeRIP) and RNA stability assays.Results: RA-FLSs proliferation, migration, and invasion were significantly higher than those of normal FLSs (p < 0.01). The cells entered S phase, and apoptosis decreased. Meanwhile, METTL3 and ATIC protein expression levels were increased (p < 0.01). MTX suppressed RA-FLS proliferation and migration (p < 0.01), triggered G0/G1 phase arrest and apoptosis (p < 0.001), and decreased METTL3 and ATIC protein levels (p < 0.05). METTL3 overexpression restored ATIC protein expression (p < 0.01) and reversed MTX’s cellular functional control on RA-FLSs (p < 0.01). METTL3 mediated m6A modification of ATIC mRNA, which elevated the m6A enrichment level of the ATIC transcript (p < 0.001) and slowed its mRNA degradation (p < 0.05).Conclusion: MTX reduces m6A enrichment in ATIC mRNA by suppressing METTL3, thereby decreasing ATIC expression. This METTL3-ATIC regulatory axis is associated with altered proliferation and apoptosis of RA-FLSs, suggesting a potential epitranscriptomic mechanism that may contribute to MTX’s therapeutic effects. This study provides preliminary in vitro evidence for a novel molecular pathway underlying MTX activity in RA-related synovial fibroblasts and identifies directions for future mechanistic investigation in rheumatoid arthritis.
Background: Oral lichen planus (OLP) is a chronic inflammatory and immune-mediated oral mucosal disease characterized by epithelial damage, basal cell degeneration, and recurrent lesions. However, the molecular mechanisms responsible for keratinocyte injury and apoptosis during OLP progression remain incompletely understood. This study aimed to investigate the protective role of scinderin (SCIN) and the potential involvement of epidermal growth factor receptor (EGFR) signaling during lipopolysaccharide (LPS)-induced inflammatory stress in human oral keratinocytes (HOKs).Methods: HOKs underwent transfection and were treated with LPS. Relative 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) metabolic activity and apoptosis were evaluated using an MTT assay and flow cytometry. Apoptosis-related proteins were assessed using Western blotting. Caspase 3 and 9 activities were assessed using a fluorometric assay. SCIN expression was analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting, whereas total EGFR, inhibitor of nuclear factor kappa B alpha (IκBα), and their phosphorylated forms were evaluated by Western blotting.Results: LPS stimulation decreased SCIN and total EGFR protein levels and relative MTT metabolic activity while increasing p-EGFR protein levels and p-EGFR/EGFR ratios (p < 0.001). LPS also promoted apoptosis, as evidenced by an increased apoptotic rate, elevated BCL-2-associated X protein (BAX) expression, cleaved caspase 3/caspase 3 ratio, and caspase 3 and caspase 9 activities, as well as decreased B-cell lymphoma 2 (BCL-2) expression (p < 0.05). SCIN overexpression significantly counteracted these LPS-induced molecular and cellular changes (p < 0.05). Compared with the Control group, LPS treatment also increased the phosphorylated (p)-IκBα/IκBα ratio (p < 0.001). EGFR knockdown further aggravated LPS-induced injury, whereas SCIN overexpression partially alleviated the associated apoptotic changes under EGFR knockdown conditions (p < 0.05).Conclusion: SCIN overexpression alleviated LPS-induced apoptosis in HOKs and was associated with changes in EGFR expression and phosphorylation. These findings highlight SCIN as a potential regulator of keratinocyte responses to inflammatory stress and support its further investigation in OLP-associated epithelial injury.
Background: Bronchopulmonary dysplasia reflects an alveolar epithelium in which the differentiation program remains incomplete. CCAAT/enhancer-binding protein α (C/EBPα) is indispensable for alveolar type II (AT2) maturation, yet the mechanisms governing its abundance under oxidant stress remain unexamined. Because canonical Wnt/β-catenin signaling has been reported to reduce C/EBPα in other lineages, we asked whether β-catenin signaling modulates C/EBPα in hyperoxia-exposed alveolar epithelium and whether this is accompanied by changes in differentiation marker expression.Methods: Rat AT2-like RLE-6TN cells were exposed to 95% O2 for 48 h. Wnt output was manipulated bidirectionally with ICG-001 (10 µM) under hyperoxia and lithium chloride (20 mM) under normoxia, while β-catenin was silenced under hyperoxia and overexpressed under normoxia. The contribution of C/EBPα was examined by silencing it during Wnt inhibition and by restoring it under continued hyperoxia without manipulating the pathway. Pathway activity (active β-catenin, Axin2), C/EBPα, differentiation markers (pro-SP-C/Sftpc, AQP5/Aqp5) and apoptosis were assessed.Results: Hyperoxia increased active β-catenin and Axin2 and reduced C/EBPα, pro-SP-C and AQP5, with increased apoptosis (all p < 0.001). ICG-001 reduced Axin2 without altering active β-catenin and increased C/EBPα, pro-SP-C and AQP5, whereas pharmacological glycogen synthase kinase-3β (GSK-3β) inhibition with lithium chloride reproduced the hyperoxic pattern under normoxia. β-catenin silencing under hyperoxia increased C/EBPα, Sftpc and Aqp5, whereas β-catenin overexpression under normoxia reduced them (all p < 0.001). Silencing C/EBPα markedly attenuated the ICG-001-induced increases in Sftpc and Aqp5, while C/EBPα overexpression alone increased both despite persistent hyperoxia.Conclusions: Canonical Wnt/β-catenin activity and C/EBPα abundance were inversely associated across perturbation experiments in hyperoxia-exposed AT2-like cells, and C/EBPα appears to contribute substantially to the effect of Wnt inhibition on differentiation marker expression. These findings support a functional β-catenin-C/EBPα relationship that may contribute to hyperoxia-associated changes in alveolar differentiation marker expression, pending mechanistic and in vivo confirmation.
Immune checkpoint inhibitors (ICI) targeting the programmed cell death protein-1 (PD-1)/programmed death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) axes have transformed the treatment landscape of genitourinary (GU) malignancies, yielding durable responses in subsets of patients with urothelial carcinoma, renal cell carcinoma (RCC), and selected cases of metastatic castration-resistant prostate cancer (mCRPC). However, most patients exhibit primary resistance, and those who initially respond frequently develop acquired resistance, substantially limiting long-term clinical benefit. A systematic understanding of the biological mechanisms driving resistance, the identification of robust predictive biomarkers, and the design of rational combination strategies are essential to extend the therapeutic reach of ICI-based regimens. To address this need, an integrative review was conducted following the Whittemore and Knafl (2005) framework. Systematic searches were performed in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Embase, and Web of Science, covering the period January 2020 to April 2026. Studies were selected according to predefined inclusion criteria encompassing original research, clinical trials, systematic reviews, and narrative reviews reporting on resistance mechanisms, predictive biomarkers, or emerging therapeutic strategies for ICI in GU cancers. A total of 32 studies met eligibility criteria. Three interconnected resistance categories were identified: (1) tumor cell-intrinsic mechanisms, including low tumor mutational burden (TMB), loss of antigen presentation via major histocompatibility complex class I (MHC-I) downregulation, activation of the Wnt/β-catenin and JAK/STAT pathways, and epigenetic reprogramming; (2) tumor microenvironment (TME)-mediated immunosuppression, driven by myeloid-derived suppressor cells (MDSCs), regulatory T cells (Tregs), cancer-associated fibroblasts (CAFs), and immunosuppressive cytokines including TGF-β and vascular endothelial growth factor (VEGF); and (3) acquired post-treatment resistance involving T-cell exhaustion and upregulation of alternative immune checkpoints. Among validated or clinically used biomarkers, PD-L1 expression demonstrated variable predictive utility across GU cancer types, while TMB-high status (≥10 mutations/megabase) predicted improved response to pembrolizumab across solid tumors. Emerging therapeutic strategies include ICI plus tyrosine kinase inhibitor (TKI) combinations, antibody-drug conjugates (ADCs), MDSC-targeted interventions, therapeutic vaccines, and radiotherapy sensitization. Overall, ICI resistance in GU cancers emerges as a multidimensional phenomenon with distinct biological drivers across tumor subtypes; precision combinations targeting both intrinsic tumor factors and the immunosuppressive TME represent the most promising avenue to overcome resistance, and standardization of composite biomarker platforms is urgently needed to individualize ICI selection in clinical practice.
