BACKGROUND Stem cell therapy has been recognized as a promising strategy for enhancing cardiac function after myocardial infarction.Nonetheless,its clinical benefits are frequently limited by the poor survival and dif...BACKGROUND Stem cell therapy has been recognized as a promising strategy for enhancing cardiac function after myocardial infarction.Nonetheless,its clinical benefits are frequently limited by the poor survival and differentiation rates of the transplanted cells.AIM To clarify the role of hypoxia-inducible factor-1α(HIF-1α)/β-catenin in survival and angiogenesis of peripheral blood mesenchymal stem cells(PBMSCs).METHODS PBMSCs were isolated from rat abdominal aorta blood and characterized by multipotent differentiation assays.Cells were cultured under hypoxic conditions,followed by either overexpression or silencing of HIF-1α/β-catenin.Proliferative capacity was evaluated via colony formation assays,while cellular senescence was assessed usingβ-galactosidase staining.The protein and/or mRNA expressions of HIF-1α,β-catenin,basic fibroblast growth factor(bFGF),vascular endothelial growth factor(VEGF),survivin,Bcl2,Bax,cleaved caspase 3 were detected viawestern blotting and/or quantitative real-time polymerase chain reaction.PBMSCs co-expressing elevated HIF-1αandβ-catenin levels were transplanted into infarcted myocardial tissue to evaluate their therapeutic potential in vivo.RESULTS HIF-1αorβ-catenin overexpression enhanced self-renewal and inhibit apoptosis of PBMSCs by up-regulating Bcl2 and survivin,down-regulating Bax and cleaved-caspase 3.Besides,HIF-1αorβ-catenin overexpression elevated angiogenesis via increasing bFGF and VEGF expressions.Silence of HIF-1αorβ-catenin had opposite effect.Upregulation of HIF-1αincreasedβ-catenin expression,whereas modifications inβ-catenin did not influence HIF-1αexpression.Chromatin immunoprecipitation assay verified that HIF-1αdirectly modulatesβ-catenin transcription.In vivo,HIF-1αoverexpression significantly improved the retention of transplanted PBMSCs in infarcted myocardium and enhanced myocardial repair.Functional analysis further confirmed that HIF-1αoperated throughβ-catenin,which directly modulated the expression of bFGF,VEGF,survivin,Bcl2,Bax and cleaved caspase 3,thereby coordinating the anti-apoptotic and pro-angiogenic functions of transplanted PBMSCs.CONCLUSION This study highlights the modulatory function of HIF-1αon PBMSCs viaβ-catenin-driven anti-apoptotic and angiogenic signaling cascade under hypoxia environment,offering a promising strategy for improving the therapeutic effectiveness PBMSCs-based transplantation after myocardial infarction.展开更多
基金Guangdong Provincial Natural Science Foundation General Program,No.2025A1515012455Guangzhou Municipal Science and Technology Project,No.2024A03J0653,No.2023A03J0595,No.2023A03J0510,No.2023A03J0528.
文摘BACKGROUND Stem cell therapy has been recognized as a promising strategy for enhancing cardiac function after myocardial infarction.Nonetheless,its clinical benefits are frequently limited by the poor survival and differentiation rates of the transplanted cells.AIM To clarify the role of hypoxia-inducible factor-1α(HIF-1α)/β-catenin in survival and angiogenesis of peripheral blood mesenchymal stem cells(PBMSCs).METHODS PBMSCs were isolated from rat abdominal aorta blood and characterized by multipotent differentiation assays.Cells were cultured under hypoxic conditions,followed by either overexpression or silencing of HIF-1α/β-catenin.Proliferative capacity was evaluated via colony formation assays,while cellular senescence was assessed usingβ-galactosidase staining.The protein and/or mRNA expressions of HIF-1α,β-catenin,basic fibroblast growth factor(bFGF),vascular endothelial growth factor(VEGF),survivin,Bcl2,Bax,cleaved caspase 3 were detected viawestern blotting and/or quantitative real-time polymerase chain reaction.PBMSCs co-expressing elevated HIF-1αandβ-catenin levels were transplanted into infarcted myocardial tissue to evaluate their therapeutic potential in vivo.RESULTS HIF-1αorβ-catenin overexpression enhanced self-renewal and inhibit apoptosis of PBMSCs by up-regulating Bcl2 and survivin,down-regulating Bax and cleaved-caspase 3.Besides,HIF-1αorβ-catenin overexpression elevated angiogenesis via increasing bFGF and VEGF expressions.Silence of HIF-1αorβ-catenin had opposite effect.Upregulation of HIF-1αincreasedβ-catenin expression,whereas modifications inβ-catenin did not influence HIF-1αexpression.Chromatin immunoprecipitation assay verified that HIF-1αdirectly modulatesβ-catenin transcription.In vivo,HIF-1αoverexpression significantly improved the retention of transplanted PBMSCs in infarcted myocardium and enhanced myocardial repair.Functional analysis further confirmed that HIF-1αoperated throughβ-catenin,which directly modulated the expression of bFGF,VEGF,survivin,Bcl2,Bax and cleaved caspase 3,thereby coordinating the anti-apoptotic and pro-angiogenic functions of transplanted PBMSCs.CONCLUSION This study highlights the modulatory function of HIF-1αon PBMSCs viaβ-catenin-driven anti-apoptotic and angiogenic signaling cascade under hypoxia environment,offering a promising strategy for improving the therapeutic effectiveness PBMSCs-based transplantation after myocardial infarction.
