BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as...BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.展开更多
Interferon Regulatory Factor-2 (IRF-2) belongs to IRF family, was identified as a mammalian transcription factor involved in Interferon beta (IFNβ) gene regulation. Besides that IRF-2 is involved in immunomodulation,...Interferon Regulatory Factor-2 (IRF-2) belongs to IRF family, was identified as a mammalian transcription factor involved in Interferon beta (IFNβ) gene regulation. Besides that IRF-2 is involved in immunomodulation, hematopoietic differentiation, cell cycle regulation and oncogenesis. We have done molecular sub-cloning and expression of recombinant murine IRF-2 as GST (Glutathione-S-Transferase)- IRF-2 fusion protein in E. coli/XL-1blue cells. Recombinant IRF-2 with GST moiety at N-terminus expressed as GST-IRF-2 (~66 kd) in E. coli along with different low molecular mass degradation products revealed approximately 30, 42, 60 and 62 kd by SDS-PAGE and Western blot, respectively. We further confirm that degradation takes place at C-terminus of the fusion protein not at N-terminus as anti-GST antibody was detecting all bands in the immunoblot. The recombinant IRF-2 was biologically active along with their degradation products in terms of their DNA binding activity as assessed by Electrophoretically Mobility Shift Assay (EMSA). We observed three different molecular mass DNA/protein complexes (1 - 3) with Virus Response Element (VRE) derived from human Interferon IFNβ gene and five different molecular mass complexes (1 - 5) with IRF-E motif (GAAAGT)4 in EMSA gel. GST only expressed from empty vector did not bind to these DNA elements. To confirm that the binding is specific, all complexes were competed out completely when challenged with 100-X fold molar excess of IRF-E oligo under cold competition. It means degradation products along with full-length protein are able to interact with VREβ as well as IRF-E motif. This means degradation products may regulate the target gene (s) activation/repression via interacting with VRE/IRF-E.展开更多
目的构建转录因子E2-2基因腺病毒载体,观测内皮祖细胞(endothelial progenitor cells,EPCs)过表达E2-2基因对DNA结合抑制因子-1(inhibitor of DNA binding/differentiation,ID1)表达的影响。方法分离、培养并鉴定小鼠骨髓EPCs。RT-PCR...目的构建转录因子E2-2基因腺病毒载体,观测内皮祖细胞(endothelial progenitor cells,EPCs)过表达E2-2基因对DNA结合抑制因子-1(inhibitor of DNA binding/differentiation,ID1)表达的影响。方法分离、培养并鉴定小鼠骨髓EPCs。RT-PCR法扩增E2-2基因CDs全长DNA,克隆入载体pTG19-T后,亚克隆入腺病毒穿梭载体pAdTrack-CMV中,构建pAdTrack/E2-2重组载体,与pAdEasy-1骨架质粒同源重组形成重组病毒pAd/E2-2,经293细胞包装,获具高效感染力的重组pAd/E2-2病毒。将该病毒感染EPCs,倒置显微镜观测经感染的EPCs的GFP表达情况。CCK-8(cell count kit-8)法检测病毒pAd/E2-2对EPCs生长、增殖的影响。RT-PCR、Western blot分别检测经感染的EPCs中E2-2与ID1基因及其编码蛋白的表达情况,并予以定量分析。结果分离、培养并鉴定到小鼠骨髓EPCs。克隆到2013 bp的E2-2基因,并获得高效感染力的重组pAd/E2-2病毒。CCK-8法检测表明,与对照比较,过表达E2-2的EPCs的生长、增殖速度减慢,48h开始变得尤为明显(P<0.01);RT-PCR、Western blot及定量分析结果显示,E2-2能下调ID1的表达,与对照比较,差异具统计学意义(P<0.01)。结论分离、培养并鉴定小鼠骨髓EPCs,克隆出E2-2基因,证实E2-2能明显抑制EPCs的生长、增殖,并能下调ID1基因的表达。展开更多
目的观察金雀异黄酮对缺氧体外培养大鼠骨髓间充质干细胞(BMSCs)增殖与成骨分化的影响。方法采用贴壁筛选法体外培养BMSCs并用三气培养箱建立缺氧模型。设常氧对照组、缺氧对照组和缺氧加药组,其中缺氧加药组细分为1×10-8、1×...目的观察金雀异黄酮对缺氧体外培养大鼠骨髓间充质干细胞(BMSCs)增殖与成骨分化的影响。方法采用贴壁筛选法体外培养BMSCs并用三气培养箱建立缺氧模型。设常氧对照组、缺氧对照组和缺氧加药组,其中缺氧加药组细分为1×10-8、1×10-7和1×10-6 mol.L-1组金雀异黄酮组,缺氧处理36 h后分析各组的细胞增殖和成骨性指标包括碱性磷酸酶(ALP)活性、Ⅰ型胶原表达、钙盐沉积量和钙化结节面积等,并用Real Time RT-PCR法检测Runx2和骨形成蛋白(BMP)-2的基因表达情况。结果与缺氧对照组比较,金雀异黄酮抑制BMSCs增殖,显著提高ALP活性、Ⅰ型胶原表达量、钙盐沉积量和钙化结节面积,并提高基因Runx2和BMP-2的表达水平,且呈现出剂量依赖性特点。结论金雀异黄酮具有抑制缺氧BMSCs增殖并促进其成骨分化的作用。展开更多
基金Supported by the Higher Education Commission(HEC),Pakistan Scholarship for Ph.D.Studies to Razzaq SS,No.520-148390-2BS6-011.
文摘BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.
文摘Interferon Regulatory Factor-2 (IRF-2) belongs to IRF family, was identified as a mammalian transcription factor involved in Interferon beta (IFNβ) gene regulation. Besides that IRF-2 is involved in immunomodulation, hematopoietic differentiation, cell cycle regulation and oncogenesis. We have done molecular sub-cloning and expression of recombinant murine IRF-2 as GST (Glutathione-S-Transferase)- IRF-2 fusion protein in E. coli/XL-1blue cells. Recombinant IRF-2 with GST moiety at N-terminus expressed as GST-IRF-2 (~66 kd) in E. coli along with different low molecular mass degradation products revealed approximately 30, 42, 60 and 62 kd by SDS-PAGE and Western blot, respectively. We further confirm that degradation takes place at C-terminus of the fusion protein not at N-terminus as anti-GST antibody was detecting all bands in the immunoblot. The recombinant IRF-2 was biologically active along with their degradation products in terms of their DNA binding activity as assessed by Electrophoretically Mobility Shift Assay (EMSA). We observed three different molecular mass DNA/protein complexes (1 - 3) with Virus Response Element (VRE) derived from human Interferon IFNβ gene and five different molecular mass complexes (1 - 5) with IRF-E motif (GAAAGT)4 in EMSA gel. GST only expressed from empty vector did not bind to these DNA elements. To confirm that the binding is specific, all complexes were competed out completely when challenged with 100-X fold molar excess of IRF-E oligo under cold competition. It means degradation products along with full-length protein are able to interact with VREβ as well as IRF-E motif. This means degradation products may regulate the target gene (s) activation/repression via interacting with VRE/IRF-E.
文摘目的观察金雀异黄酮对缺氧体外培养大鼠骨髓间充质干细胞(BMSCs)增殖与成骨分化的影响。方法采用贴壁筛选法体外培养BMSCs并用三气培养箱建立缺氧模型。设常氧对照组、缺氧对照组和缺氧加药组,其中缺氧加药组细分为1×10-8、1×10-7和1×10-6 mol.L-1组金雀异黄酮组,缺氧处理36 h后分析各组的细胞增殖和成骨性指标包括碱性磷酸酶(ALP)活性、Ⅰ型胶原表达、钙盐沉积量和钙化结节面积等,并用Real Time RT-PCR法检测Runx2和骨形成蛋白(BMP)-2的基因表达情况。结果与缺氧对照组比较,金雀异黄酮抑制BMSCs增殖,显著提高ALP活性、Ⅰ型胶原表达量、钙盐沉积量和钙化结节面积,并提高基因Runx2和BMP-2的表达水平,且呈现出剂量依赖性特点。结论金雀异黄酮具有抑制缺氧BMSCs增殖并促进其成骨分化的作用。
