Archives of biochemistry and biophysics最新文献

Background: Diabetic encephalopathy (DE), a severe neurological complication of diabetes, is characterized by cognitive decline and neuronal damage. While gut microbiota dysbiosis has been implicated in diabetes pathogenesis, its specific role and molecular mechanisms in DE remain unclear.

Methods: A multi-omics approach integrating 16S rRNA sequencing and untargeted metabolomics was performed on fecal samples from 29 DE patients and 31 diabetic controls (DM). An in vitro DE model was established using high glucose (HG)-treated HT22 cells, which were further incubated with sterile fecal microbiota supernatant (FMS) from DE patients. Neuronal viability, apoptosis, oxidative stress markers (SOD, MDA, ROS), and miR-493-3p expression were assessed. The miR-493-3p/RAF1 interaction was validated using dual-luciferase reporter assays and Western blot.

Results: No significant differences in overall microbial diversity were identified in DE and DM cohorts. However, DE patients exhibited distinct gut microbiota composition, with elevated Verrucomicrobiotaand Bacteroidota, and reduced Proteobacteriaand Firmicutes. Metabolomic analysis revealed 160 differentially abundant metabolites enriched in amino acid and lipid metabolism pathways. In vitro, DE-derived FMS dose-dependently exacerbated HG-induced neuronal oxidative damage and apoptosis, concomitant with miR-493-3p upregulation. Inhibition of miR-493-3p attenuated these damaging effects and restored RAF1 expression. RAF1 was confirmed as a direct target of miR-493-3p, and its downregulation was critical in mediating FMS-induced neuronal injury.

Conclusion: This study identified a novel gut-brain axis pathway in DE, whereby gut microbiota dysbiosis and metabolic alterations promote neuronal damage via the miR-493-3p/RAF1 signaling axis. These findings provide new insights into DE pathogenesis and suggest potential therapeutic targets for this debilitating complication.

Background: Ischemia/reperfusion injury (IRI) is a major cause of acute kidney injury (AKI), primarily driven by the increased production of reactive oxygen species (ROS). Elevated ROS levels can lead to cell apoptosis. However, effective therapeutic targets for IRI remain limited.

Purpose: This study aims to investigate the potential mechanisms by which BHMT modulates IRI.

Methods: RT-qPCR and Western blot were used to assess RNA and protein expression levels. MTT assay, flow cytometry, and ROS-related assays were employed to evaluate renal cell injury in vitro. Mechanistic studies were conducted to explore molecular interactions, while in vivo assays were used to assess IRI.

Results: Betaine-homocysteine S-methyltransferase (BHMT) was found to be downregulated in both ischemia/reperfusion (I/R) and hypoxia/reoxygenation (H/R) models. BHMT overexpression mitigated the effects of H/R or I/R on ROS production and cell apoptosis. Mechanistically, BHMT enhanced the synthesis of S-adenosylmethionine (SAM), which in turn increased DNA-methyltransferase (DNMT) activity. This facilitated methylation of the NADPH Oxidase 4 (NOX4) promoter, suppressing NOX4 transcription and expression. Rescue assays confirmed that BHMT reduced ROS production and cell apoptosis in H/R-treated renal cells by downregulating NOX4. Furthermore, elevated expression of Samd4a in I/R accelerated renal fibrosis progression through activation of the Wnt/β-catenin signaling pathway.

Conclusion: BHMT reduces ROS-induced apoptosis by downregulating NOX4, offering protection against renal IRI. Additionally, targeting Samd4a expression may provide a therapeutic approach for preventing chronic kidney disease in kidney injury models.

Our previous studies identified recombinant human MG53 (rhMG53) as a novel regulator that inhibits endothelial cell migration and angiogenesis by modulating focal adhesion kinase (FAK) signaling. However, the specific structural component of rhMG53 responsible for its inhibitory effects on angiogenesis has not yet been elucidated. Here, we generated a series of rhMG53 mutants and found that both the ΔB mutant (deletion of the B-box domain of rhMG53) and the ΔS mutant (deletion of the PRY-SPRY domain of rhMG53) failed to decrease endothelial migration and tube formation in vitro, indicating the critical roles of these two domains in rhMG53-regulated angiogenesis. Mechanistically, only the ΔB mutant failed to interact with FAK, suggesting that the B-box domain may function as a FAK-interacting domain. Notably, both the B-box and PRY-SPRY domains are essential for the inhibitory effects of rhMG53 on the activation of the FAK/Src/paxillin signaling pathway. Furthermore, the significance of these two domains in the anti-angiogenic activity of rhMG53 was further confirmed in the aortic ring vessel outgrowth assay and in the alkaline-induced corneal neovascularization model. These findings highlight the novel roles of the B-box and PRY-SPRY domains in rhMG53-regulated angiogenesis and enhance our understanding of rhMG53 in modulating endothelial functions.

Objectives: Metformin may exert anticancer effects in non-small cell lung cancer (NSCLC) by influencing long non-coding RNAs involved in the disease's pathology. The Study aimed to investigate the inhibitory effect of metformin on NSCLC by modulating the expression of lncRP11-242D8.1.

Methods: Inflammation and apoptosis levels in NSCLC were assessed at the molecular level using immunofluorescence, RT-qPCR, and ELISA. Metformin's effects on NSCLC in vitro were evaluated by CCK8, scratch wound healing, Transwell, colony formation, flow cytometry assays, etc. Bioinformatics analysis and molecular experiments were combined to investigate the mechanisms involving metformin and lncRP11-242D8.1.

Results: Low expression of lncRP11-242D8.1 is positively correlated with increased inflammation and decreased apoptosis, leading to poor prognosis in NSCLC. Treatment with metformin in the H1299 cell model improved this trend.

Conclusion: This study suggests that metformin treats NSCLC by upregulating lncRP11-242D8.1 expression, which inhibits inflammation and promotes apoptosis, offering a new perspective for clinical treatment.

Chemotherapy-induced ncRNA-mediated plasticity is an emerging concept in cancer research. To that end, we observed a cisplatin-responsive regulatory program centered on piRNA activation. OSCC cells exposed to cisplatin markedly promoted the piRNA expression, with piR-hsa-30937 showing the most prominent upregulation. Mechanistically, cisplatin disrupts the OCT1-DNMT1 repressive complex that mediates DNA methylation of transcription factor binding sites of piR-hsa-30937, to derepress its expression. Functionally, piR-hsa-30937 targets GAB2 and sensitizes OSCC cells to cisplatin by suppressing proliferation, enhancing apoptosis, and γ-H2AX accumulation. Furthermore, GAB2 overexpression reversed these effects and desensitized OSCC cells to cisplatin by activating NF-κB-mediated JNK suppression. Overall, cisplatin actively remodels the OCT1-DNMT1-piR-hsa-30937 axis regulating piRNA expression, which in turn potentiates cisplatin cytotoxicity by attenuating GAB2-mediated survival signaling in OSCC.

Adipose-derived mesenchymal stem cell-derived exosomes (ADMSC-ex) have demonstrated remarkable efficacy in promoting diabetic wound healing. However, the underlying mechanisms remain largely elusive. In this study, we showed the healing process of skin wounds in diabetic rats was notably delayed, but this delay was mitigated by the administration of ADMSCs-ex. Neutrophil extracellular traps (NETs) formation was significantly upregulated in the skin wounds from the diabetes group. ADMSCs-ex administration attenuated this upregulation. The upregulation of S100A9 was confirmed in wound tissues from diabetic rats, as well as neutrophils induced by high glucose. ADMSCs-ex administration significantly reduced S100A9 protein expression via delivering miR-92a-1-5p in vitro. In vivo study showed that miR-92a-1-5p knockdown obstructed the promotional effect of ADMSCs-ex on diabetic wound healing and NETs formation. In conclusion, this study provides evidence that ADMSCs-ex accelerate diabetic wounds healing via a conserved miR-92a-1-5p/S100A9 pathway. These findings suggest that these exosomes loaded with miR-92a-1-5p may represent a promising therapeutic approach for the management of impaired healing of diabetic wounds.

Previous studies have shown that bone marrow aspirate concentrate (BMAC) can promote tendon-bone interface healing in a rabbit chronic rotator cuff tear model, but its underlying mechanism of action has not been fully elucidated. We suspected that the synergistic effect of platelet-rich plasma (PRP) and bone marrow mesenchymal stem cells (BMSCs) in BMAC might improve the anti-apoptotic and paracrine effects of BMSCs. Here, we prepared rabbit PRP and BMSCs, and found that PRP not only attenuated hypoxic and serum-free medium (H/SF)-induced apoptosis of BMSCs but also increased the protein expression of Bcl2, which was reduced by H/SF, and decreased the protein expression of cleaved caspase 9, and cleaved caspase 3, which was elevated by H/SF, in BMSCs. PRP also promoted the expression of growth factors (PDGF, VEGF, TGF-β1, and IGF-1) in BMSCs. In a chronic rotator cuff tear rabbit model, the PRP + BMSC-treated group showed higher values of biomechanical properties than the BMSC-treated group. Furthermore, results also showed that PRP promoted the phosphorylation of Akt in BMSCs, and inhibition of the PI3K/Akt pathway not only increased the apoptosis of BMSCs cultured with PRP, but it also decreased the concentration of growth factors in culture medium of BMSCs. Collectively, our results indicate that PRP enhances the anti-apoptotic and paracrine effects of BMSCs, and this might be related to the activation of the PI3K/Akt pathway in BMSCs by PRP.

Background: Chronic endometritis (CE) is a common gynecological disorder linked to infertility, but its pathogenesis remains unclear.

Aim: To investigate the role of lncRNA MALAT1 in lipopolysaccharide (LPS)-induced endometritis and its regulatory mechanism involving the miR-142-3p/PIK3R1 axis.

Methods: A total of 133 patients with chronic endometritis (CE) and 100 healthy controls were enrolled. Serum and endometrial tissue samples were collected to detect the expression levels of MALAT1, miR-142-3p, and PIK3R1 using RT-qPCR. LPS-treated human endometrial stromal cells (HESCs) were used to establish an endometritis cell model. Cell transfection with MALAT1 siRNA, miR-142-3p mimic/inhibitor, and their negative controls was performed. ELISA was used to measure the concentrations of IL-6, IL-1β, and TNF-α. The CCK-8 assay assessed cell viability. Bioinformatics tools (lncLocator, Starbase, STRING) and dual-luciferase reporter assay validated the targeting relationships among MALAT1, miR-142-3p, and PIK3R1. Western blot assay was performed to measure the protein expression of PIK3R1 and PI3K/Akt pathway.

Results: MALAT1 and PIK3R1 were upregulated in serum and tissues of CE patients, while miR-142-3p was downregulated. MALAT1 had certain diagnostic value for distinguishing CE from healthy controls. LPS treatment induced inflammatory responses in HESCs, and knockdown of MALAT1 inhibited LPS-induced overexpression of IL-6, IL-1β, and TNF-α. Mechanistically, MALAT1 directly targeted miR-142-3p, and miR-142-3p targeted PIK3R1. Co-transfection of si-MALAT1 and miR-142-3p inhibitor partially reversed the anti-inflammatory effect of MALAT1 knockdown by regulating PI3K/Akt pathway.

Conclusion: MALAT1 promotes LPS-induced endometritis progression by modulating miR-142-3p to upregulate PIK3R1, suggesting the MALAT1/miR-142-3p/PIK3R1 axis as a potential diagnostic indicator and therapeutic target for CE.

Background: Prostate cancer (PC) remains a major public health challenge, with emerging evidence suggesting that microRNA-93-5p (miR-93-5p) plays a critical role in cancer progression.

Aim: This study investigated how exosomal miR-93-5p derived from PC cells modulates tumor-associated macrophage (TAM) polarization and influences PC progression, while elucidating the underlying molecular mechanisms.

Methods: We analyzed miR-93-5p expression levels in PC tissues and serum samples, followed by detailed characterization of PC cell-derived exosomes. Subsequently, we evaluated the capacity of these exosomes to induce macrophage polarization, examined the regulatory relationship between miR-93-5p and suppressor of cytokine signaling 6 (SOCS6), and assessed the activation status of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway.

Results: Elevated miR-93-5p levels in PC tissues and serum were significantly associated with metastatic features. We demonstrated that PC cell-derived exosomes enriched with miR-93-5p effectively reprogram macrophages toward an immunosuppressive M2 phenotype. Mechanistically, this polarization was mediated through miR-93-5p-induced downregulation of SOCS6, a negative regulator of cytokine signaling, leading to subsequent activation of the JAK2/STAT3 pathway, which enhances PC cell motility and invasiveness. Importantly, xenograft experiments confirmed that miR-93-5p-enriched macrophages substantially accelerated tumor growth in vivo.

Conclusion: Our findings reveal that exosomal miR-93-5p from PC cells drives M2 macrophage polarization and disease progression through SOCS6 suppression and JAK2/STAT3 pathway activation. These results identify exosomal miR-93-5p as a promising therapeutic target and provide new avenues for developing innovative treatment strategies against PC.