Stem Cell Research & Therapy•2026•DOI: 10.1186/s13287-026-04974-x
Background Variants in OTUD5 are associated with neurodevelopmental disorders (NDDs), yet the underlying molecular mechanisms remain unclear. This study aimed to investigate the pathogenicity of a novel OTUD5 variant (c.697G > A, p.Val233Met) and elucidate its regulatory role in neural progenitor cell (NPC) proliferation and differentiation, thereby uncovering the function of OTUD5 in neurodevelopment. Methods The OTUD5 variant was identified in two NDD patients via exome sequencing. Patient-derived induced pluripotent stem cells (iPSCs) and CRISPR/Cas9-corrected isogenic controls were generated. NPC proliferative activity was assessed by Ki67 immunofluorescence staining, cell-cycle distribution was analyzed by flow cytometry, and neuronal differentiation was evaluated by Tuj1/MAP2 immunofluorescence staining. Substrate screening was conducted in HEK293T cells using co-immunoprecipitation (Co-IP) and mass spectrometry. Deubiquitination capacity and protein stability were validated through ubiquitination assays and cycloheximide (CHX) chase experiments. Results The p.Val233Met variant, located within the catalytic OTU domain, induced a marked conformational alteration in the OTUD5 protein. Functionally, the variant caused aberrant NPC proliferation (1.8-fold increase in Ki67+ cells, accompanied by release of G1 arrest) and impaired neuronal differentiation (60% reduction in Tuj+ cells). Mechanistically, wild-type OTUD5 stabilized GSK3β by removing K48-linked ubiquitin chains, whereas the mutant isoform exhibited diminished deubiquitinase activity, accelerating GSK3β degradation and shortening its half-life by 40%. Conclusion This study establishes a novel disease mechanism whereby OTUD5 mutations disrupt NPC homeostasis through GSK3β destabilization, highlighting the critical role of ubiquitination regulation in neurodevelopment. Our iPSC model provides a platform for testing GSK3β-targeted therapies in OTUD5-related NDDs.
Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04480-6
Background Diabetic foot ulcers (DFU) typically exhibit impaired healing due to dysregulated re-epithelialization and excessive inflammation. Succinate, a key metabolic intermediate, is now understood to regulate inflammation through G Protein-Coupled Receptor 91 (GPR91) and succinate dehydrogenase (SDH), although its role in DFU remains unclear. Methods Co-cultures of M2 macrophages and epithelial cells, along with clinical samples, were used to analyze the expression of GPR91 and SDH. Functional assays were performed using high glucose (HG)-treated M2 macrophages (HG-M2) and an in vivo model. Cytokine and growth factor levels in cell supernatant were measured, and molecular mechanisms were explored via qRT-PCR, flow cytometry, and western blot analysis. Results Elevated glucose concentrations increased succinate levels and disrupted M2 macrophage–epidermal stem cells (EpSCs) interactions. GPR91 knockdown worsened HG-M2 dysfunction, while GPR91 overexpression (OE-GPR91) enhanced anti-inflammatory responses and reduced succinate. OE-GPR91-conditioned medium preserved EpSCs stemness and promoted migration mediated by hepatocyte growth factor (HGF). SDH inhibition (via Dimethyl malonate, DMM) boosted M2 macrophage activity by reducing reactive oxygen species (ROS) and upregulating Gpr91 expression. Mechanistically, GPR91 activated the pAkt/pGSK3β/β-catenin pathway, while DMM enhanced M2 macrophage function via the PI3K-Akt/pERK1/2 pathway. Conclusions GPR91 upregulation and SDH inhibition improve HG-M2 macrophage function, reduce inflammation, and enhance HGF-mediated EpSCs repair. Targeting both pathways may represent a promising approach to promote DFU healing.
Stem Cell Research & Therapy•2025•DOI: 10.1186/s13287-025-04751-2
Background Sepsis survivors frequently develop compromised humoral immunity, manifesting as prolonged immunosuppression that increases susceptibility to secondary infections with high associated mortality. While mesenchymal stromal cells (MSCs) have demonstrated efficacy in mitigating initial inflammatory responses and improving early survival rates in murine cecal ligation and puncture (CLP) models, they show limited effectiveness against subsequent secondary infections. Given that lymphopenia represents a primary driver of this infection vulnerability, we sought to investigate whether spleen-targeted MSC therapy could prevent lymphocyte depletion and enhance protection against secondary infections. Methods In this study, we developed CXCR5-overexpressing MSCs (MSCCXCR5) to enhance their targeted migration toward splenic CXCL13. Using a CLP mouse model followed by secondary Staphylococcus aureus (S. aureus) infection, we systematically evaluated the therapeutic potential of MSCCXCR5 in combating post-sepsis immunosuppression. Results MSCCXCR5 demonstrated enhanced splenic migration, specifically homing to CXCL13-rich B-cell zones, and conferred significant protection against both S. aureus secondary infection and sepsis-induced lymphopenia. Mechanistic investigations revealed that MSCCXCR5 treatment preserved follicular and germinal center B-cell populations, maintaining splenic architecture and potentiating antigen-specific B-cell responses to CLP challenge. These effects collectively contributed to markedly improved survival outcomes in CLP mice following secondary infection. Conclusion Our findings demonstrate that MSCCXCR5 confers dual-phase protection in sepsis, improving survival during both the initial hyperinflammatory phase and subsequent immunosuppressive period. This comprehensive
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025051
Gastric cancer (GC) is a highly prevalent and lethal gastrointestinal cancer. Dysregulation of vesicle-mediated transport-related genes (VMTRGs) is closely associated with tumorigenesis and disease progression. However, the prognostic value of VMTRGs in GC remains unclear. In this study, on the basis of our proteomics data and public databases, we identify differentially expressed VMTRGs in infiltrative-type GC with more metastases and recurrences identified by Ming’s classification. Least absolute shrinkage and selection operator (LASSO) regression identifies 3 VMTRGs (SEC23A, RAB31, and GABARAPL2) from 41 infiltrative-associated VMTRGs, based on which a risk model Vesicle-Infiltrative Lasso System (VILS) is constructed, and its effectiveness and potential importance are validated by immune microenvironment analysis and functional enrichment analysis. As an independent prognostic factor for GC, VILS, combined with other clinically independent prognostic factors to form a nomogram, is effective in predicting GC prognosis. The VILS high-risk group has higher M2 macrophage and cancer-associated fibroblast infiltration, and lower infiltration of Th1 cells and natural killer cells. SEC23A is highly expressed in GC tissues and cells. The importance of SEC23A in GC cells is evaluated by in vitro assays including colony formation assay and CCK-8 assay, and by in vivo assay using a subcutaneous xenograft mouse model. The results show that SEC23A promotes GC cell proliferation and tumor growth through regulation of the cell cycle in vitro and in vivo. VILS provides excellent prognostic prediction for GC patients and is correlated with antitumor immune cell infiltration. SEC23A, the dominant gene of VILS, is highly expressed in GC and promotes GC growth and malignant progression through various molecular mechanisms. Our study reveals the effect of SEC23A on the proliferation of gastric cancer cells for the first time. Therefore, SEC23A has the potential to be a new therapeutic target for the diagnosis and treatment of GC.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2024235
Activated astrocytes and their associated inflammatory responses play critical roles in the pathogenesis of hypoxic-ischemic brain damage (HIBD). Gastrodin (GAS), an anti-inflammatory herbal agent, is known to suppress microglial activation. Here, we investigate whether it exerts a similar effect on activated astrocytes and whether it acts through S100B/RAGE-Smad3 signaling. The expression changes of S100B/RAGE-Smad3 signaling pathway-related proteins, inflammatory factors and A1/A2 astrocyte markers were detected by ELISA, western blot analysis, immunofluorescence and immunohistochemistry. The results show that GAS decreases the expression of sRAGE in the brain tissue and S100B in the serum and brain tissue of HIBD mice. However, it promotes the expression of sRAGE in the serum of HIBD mice. Moreover, GAS inhibits the expressions of RAGE, p-Smad3, TNF-α, and C3 (A1 astrocyte marker), and promotes the expressions of S100A10 (A2 astrocyte marker) and BDNF in HIBD model mice, as well as in oxygen glucose deprivation (OGD)-treated TNC-1 astrocytes. The immunofluorescence and immunohistochemical results of RAGE and p-Smad3, as well as the immunofluorescence results of C3 and S100A10, reveal the same trend. Interestingly, FPS-ZM1 (a specific inhibitor of RAGE) inhibits the expressions of p-Smad3, TNF-α, C3, and S100A10, but promotes that of BDNF compared with those in the OGD group. The combination of GAS and FPS-ZM1 further decreases the expression of C3. These results indicate that GAS can inhibit the activation of Smad3 through S100B/RAGE signaling and regulate the expression of A1/A2-type astrocytes.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025080
Macrophages are key players in the pathology of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Existing studies and our previous studies have documented the role of CD206-positive M2 macrophages in the inflammatory process of AAV. Inflammasome activation is a critical pathway through which macrophages release inflammatory factors. In this study, we investigate the role of the inflammasome in macrophages in AAV and explore the role of CD206 in this process. We recruit newly diagnosed AAV patients and disease controls from our department. The expression and localization of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) and CD206 in the kidney are determined via immunofluorescence experiments. Myeloperoxidase (MPO)-ANCA immunoglobulin G (MPO-ANCA IgG) is purified from new-onset AAV patients with MPO-ANCA and used to treat lipopolysaccharide (LPS)-primed macrophages in vitro. Our findings reveal that NLRP3 expression is significantly elevated in the kidneys of active AAV patients, accompanied by increased cleaved caspase-1 and N-terminal gasdermin-D (GSDMD) levels in peripheral blood mononuclear cells (PBMCs). In vitro, MPO-ANCA IgG induces NLRP3 inflammasome activation and interleukin (IL)-1β production in macrophages, which is associated with increased MPO expression and JNK signaling pathway activation. Immunofluorescence analysis demonstrates partial colocalization of CD206 and NLRP3 in AAV kidneys. Furthermore, silencing of MRC1 gene, which encodes CD206, reduces inflammasome activation induced by MPO-ANCA IgG. In conclusion, our study provides evidence that MPO-ANCA IgG contributes to NLRP3 inflammasome activation and macrophage pyroptosis, with CD206 playing a critical role in this process. These findings elucidate the mechanisms underlying inflammation in AAV and suggest potential therapeutic targets.
Stem Cell Research & Therapy•2026•DOI: 10.1186/s13287-026-04974-x
Background: Variants in OTUD5 are associated with neurodevelopmental disorders (NDDs), yet the underlying molecular mechanisms remain unclear. This study aimed to investigate the pathogenicity of a novel OTUD5 variant (c.697G>A, p.Val233Met) and elucidate its regulatory role in neural progenitor cell (NPC) proliferation and differentiation, thereby uncovering the function of OTUD5 in neurodevelopment. Methods: The OTUD5 variant was identified in two NDD patients via exome sequencing. Patient-derived induced pluripotent stem cells (iPSCs) and CRISPR/Cas9-corrected isogenic controls were generated. NPC proliferative activity was assessed by Ki67 immunofluorescence staining, cell-cycle distribution was analyzed by flow cytometry, and neuronal differentiation was evaluated by Tuj1/MAP2 immunofluorescence staining. Substrate screening was conducted in HEK293T cells using co-immunoprecipitation (Co-IP) and mass spectrometry. Deubiquitination capacity and protein stability were validated through ubiquitination assays and cycloheximide (CHX) chase experiments. Results: The p.Val233Met variant, located within the catalytic OTU domain, induced a marked conformational alteration in the OTUD5 protein. Functionally, the variant caused aberrant NPC proliferation (1.8-fold increase in Ki67+ cells, accompanied by release of G1 arrest) and impaired neuronal differentiation (60% reduction in Tuj+ cells). Mechanistically, wild-type OTUD5 stabilized GSK3β by removing K48-linked ubiquitin chains, whereas the mutant isoform exhibited diminished deubiquitinase activity, accelerating GSK3β degradation and shortening its half-life by 40%. Conclusion: This study establishes a novel disease mechanism whereby OTUD5 mutations disrupt NPC homeostasis through GSK3β destabilization, highlighting the critical role of ubiquitination regulation in neurodevelopment. Our iPSC model provides a platform for testing GSK3β-targeted therapies in OTUD5-related NDDs.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21243
BACKGROUND: Virtual reality has demonstrated unique advantages as a novel non-pharmacological intervention in the treatment of neuropathic pain following spinal cord injury. OBJECTIVE: To systematically review the pathogenesis of neuropathic pain following spinal cord injury, summarize the specific application modes and mechanisms of virtual reality therapy for this condition, and explore key factors influencing treatment efficacy, thereby providing novel therapeutic options for patients with neuropathic pain following spinal cord injury. METHODS: A literature search was conducted in the CNKI, PubMed, Web of Science, and Cochrane Library databases up to June 2025. The Chinese and English search terms included “spinal cord injury, central sensitization, cerebral cortex, noninvasive therapy, neuropathic pain, virtual reality.” A total of 1 352 articles were retrieved, and 73 articles that met the inclusion criteria were ultimately included in the analysis. RESULTS AND CONCLUSION: The development of neuropathic pain following spinal cord injury involves complex mechanisms in both the spinal cord and brain, closely associated with central sensitization at the spinal level and abnormal plasticity changes in the brain. Virtual reality, as a novel intervention approach, can be used alone or in combination with other intervention methods, showing unique therapeutic value for the multidimensional pathogenesis of neuropathic pain after spinal cord injury. Standalone virtual reality applications primarily involve virtual walking interventions aimed at restoring abnormal brain plasticity changes, while combined virtual reality applications have shown certain effects in both inhibiting central sensitization and modulating brain plasticity. Although virtual reality intervention shows great potential in the treatment of neuropathic pain following spinal cord injury, current research and applications still have certain limitations. Future efforts should focus on addressing these issues to fully realize the therapeutic value of virtual reality in neuropathic pain following spinal cord injury.
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21264
BACKGROUND: Previous studies have established a correlation between non-alcoholic fatty liver disease and sarcopenia; however, their causal relationship remains uncertain. The gut-muscle-liver axis hypothesis posits intricate interactions between the gut microbiota and both sarcopenia and non-alcoholic fatty liver disease, yet the precise pathogenic mechanisms underlying these interactions remain poorly elucidated. OBJECTIVE: To investigate the potential causal relationship between sarcopenia and non-alcoholic fatty liver disease using Mendelian randomization analysis and to delve into the potential role of the gut microbiota in mediating or influencing the interplay between non-alcoholic fatty liver disease and sarcopenia. METHODS: Sarcopenia data were sourced from the UK Biobank (the UK National-Level Biomedical Database, supported by the UK government and developed in 2006 in collaboration with institutions such as the University of Oxford and the University of Manchester, which encompasses multidimensional data including genes, imaging, and health records from 500 000 participants), with relevant traits including appendicular muscle mass, grip strength, and walking speed. The non-alcoholic fatty liver disease dataset was derived from a publicly accessible GWAS summary dataset compiled by Ghodsian et al., comprising aggregated statistics from GWAS cohorts including eMERGE and FinnGen, updated GWAS data of non-alcoholic fatty liver disease from the UK Biobank, and newly conducted GWAS data from the Estonian Biobank. The 211 gut microbiota data were obtained from a large-scale human gut microbiome composition study conducted by the MiBioGen consortium. Inverse variance weighting, weighted median, MR-Egger, weighted model, and simple model methods were used to assess the mutual influences among non-alcoholic fatty liver disease, sarcopenia, and gut microbiota-related traits. RESULTS AND CONCLUSION: The inverse variance weighting analysis indicated that walking speed and appendicular muscle mass were negatively correlated with non-alcoholic fatty liver disease, while left and right hand grip strength showed no significant correlation with non-alcoholic fatty liver disease risk. Reverse Mendelian randomization analysis showed that non-alcoholic fatty liver disease was negatively correlated with appendicular muscle mass, but no significant correlation was found between non-alcoholic fatty liver disease and walking speed or left and right hand grip strength. Thirty-nine gut microbiota taxa were significantly associated with sarcopenia onset, and six gut microbiota taxa had a causal relationship with non-alcoholic fatty liver disease. The study suggests that gut microbiota may regulate the 'gut-liver-muscle axis' through short-chain fatty acid metabolism, providing a new direction for cross-organ mechanism research for Chinese scholars. Combined with the unique genetic background of the Chinese population (such as ALDH2 mutations and genes related to high-salt diet), it can further analyze the race-specific pathways of metabolic-muscle comorbidity, providing a scientific basis for formulating dietary recommendations that conform to the Chinese dietary structure (such as high grain intake).
Chinese Journal of Tissue Engineering Research•2026•DOI: 10.12307/2026.21571
BACKGROUND: Numerous studies have confirmed that quercetin can inhibit the release of inflammatory factors and reduce local inflammatory responses in wounds, creating favorable conditions for wound healing. However, quercetin has poor water solubility and low bioavailability, which limits its application in wound treatment. OBJECTIVE: To investigate the antibacterial properties of quercetin-silver nanoparticle/methacrylated hyaluronic acid composite hydrogels. METHODS: Quercetin-silver nanoparticles (QuAgNPs) were synthesized by hydrothermal reduction method. QuAgNPs were loaded into methacrylated hyaluronic acid (HAMA) hydrogel precursor solution at different mass concentrations (1, 5, 10, 20, 40, 60, 80 μg/mL) to prepare composite hydrogels, denoted as 1, 5, 10, 20, 40, 60, 80 μg/mL QuAgNPs/HAMA hydrogels, while pure HAMA hydrogels were also prepared. Staphylococcus aureus was co-cultured with 1, 5, 10, 20, 40, 60, 80 μg/mL QuAgNPs/HAMA hydrogels, and antibacterial properties were detected by inhibition zone experiment. In vitro drug release properties of 60 and 80 μg/mL QuAgNPs/HAMA hydrogels were tested. Based on the results of the inhibition zone experiment, appropriate QuAgNPs/HAMA hydrogels were selected for subsequent experiments. The microstructure of HAMA hydrogel and 60 μg/mL QuAgNPs/HAMA hydrogel was observed under scanning electron microscope. Staphylococcus aureus (or Escherichia coli) were co-cultured with QuAgNPs, HAMA hydrogel, and 60 μg/mL QuAgNPs/HAMA hydrogel, with bacteria cultured alone as blank control, and antibacterial rates were detected by spread plate antibacterial experiment. Human umbilical vein endothelial cells were co-cultured with QuAgNPs, HAMA hydrogel extract, and 60 μg/mL QuAgNPs/HAMA hydrogel extract, with cells cultured alone as blank control, and cell viability was detected by live/dead cell staining. RESULTS AND CONCLUSION: The inhibition zone experiment showed that the antibacterial properties of 60 and 80 μg/mL QuAgNPs/HAMA hydrogels were stronger than those of 1, 5, 10, 20, 40 μg/mL QuAgNPs/HAMA hydrogels, and there was no difference between 60 and 80 μg/mL QuAgNPs/HAMA hydrogels. Both 60 and 80 μg/mL QuAgNPs/HAMA hydrogels had good in vitro drug release properties. Therefore, 60 μg/mL QuAgNPs/HAMA hydrogel was selected for subsequent experiments. Scanning electron microscopy showed that HAMA hydrogel had a loose porous structure, and approximately spherical QuAgNPs particles were scattered on the surface of 60 μg/mL QuAgNPs/HAMA hydrogel. Spread plate antibacterial experiment showed that QuAgNPs and 60 μg/mL QuAgNPs/HAMA hydrogel had significant inhibitory effects on Staphylococcus aureus and Escherichia coli. Live/dead cell staining showed that QuAgNPs, HAMA hydrogel, and 60 μg/mL QuAgNPs/HAMA hydrogel did not affect cell viability and had good cytocompatibility. These results indicate that QuAgNPs/HAMA composite hydrogel has good antibacterial properties.
Acta Biochimica et Biophysica Sinica•2025•DOI: 10.3724/abbs.2025080
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a life-threatening systemic autoimmune disease characterized by necrotizing small vessel vasculitis, with pauci-immune glomerulonephritis being the most severe manifestation. Macrophages, particularly CD206-positive M2 subsets, are central to AAV pathology, yet the mechanistic link between inflammasome activation and CD206 remains undefined. This study investigates NLRP3 inflammasome activity and pyroptosis in CD206+ macrophages exposed to myeloperoxidase (MPO)-ANCA immunoglobulin G (IgG). Newly diagnosed AAV patients and disease controls were recruited; renal NLRP3 and CD206 expression were assessed by immunofluorescence. MPO-ANCA IgG was purified from new-onset AAV patients and applied to lipopolysaccharide (LPS)-primed macrophages in vitro. Results demonstrate significantly elevated NLRP3 expression in active AAV kidneys, accompanied by increased cleaved caspase-1 and N-terminal gasdermin-D (GSDMD) in peripheral blood mononuclear cells (PBMCs). In vitro, MPO-ANCA IgG induces NLRP3 inflammasome activation and interleukin (IL)-1β production, associated with increased MPO expression and JNK signaling pathway activation. Immunofluorescence reveals partial colocalization of CD206 and NLRP3 in AAV kidneys. Silencing of MRC1, encoding CD206, reduces inflammasome activation induced by MPO-ANCA IgG. These findings establish that MPO-ANCA IgG contributes to NLRP3 inflammasome activation and macrophage pyroptosis, with CD206 playing a critical role. The study elucidates mechanisms underlying AAV inflammation and suggests potential therapeutic targets.