目的研究心脏发育相关基因心肌转录因子NKX2.5和锌指转录因子GATA4在先天性心脏病(CHD)的相互作用关系。方法构建基因NKX2.5和GATA4真核表达质粒及脑钠肽启动子荧光素酶报告基因表达质粒,真核表达质粒经转染后,利用免疫共沉淀技术证明基...目的研究心脏发育相关基因心肌转录因子NKX2.5和锌指转录因子GATA4在先天性心脏病(CHD)的相互作用关系。方法构建基因NKX2.5和GATA4真核表达质粒及脑钠肽启动子荧光素酶报告基因表达质粒,真核表达质粒经转染后,利用免疫共沉淀技术证明基因NKX2.5和GATA4两者是否有相互作用,通过荧光素酶分析技术分析基因NKX2.5和GATA4对脑钠肽启动子序是否存在协同激活作用。结果 p CMV-HA-NKX2.5与Pre-immune作用后蛋白表达量0,与Anti-Myc作用后蛋白表达量为3.63±1.23,与Input作用后蛋白表达量为2.95±1.05,NKX2.5可将GATA4沉淀下来;p CMV-Myc-GATA4与Pre-immune作用后蛋白表达量0,与Anti-Myc作用后蛋白表达量为5.63±2.06,与Input作用后蛋白表达量为5.75±2.86,GATA4可将NKX2.5沉淀下来;脑钠肽(BNP)启动子荧光表达质粒与两者共转染比分别单独转染NKX2.5和GATA4对脑钠肽启动子的激活作用更强。结论 NKX2.5和GATA4之间具有相互作用,在心脏发育过程中起着重要的协同作用。展开更多
SIRT1,a mammalian ortholog of yeast silent information regulator 2(Sir2),is an NAD+-dependent protein deacetylase that plays a critical role in the regulation of vascular function.The current study aims to investigate...SIRT1,a mammalian ortholog of yeast silent information regulator 2(Sir2),is an NAD+-dependent protein deacetylase that plays a critical role in the regulation of vascular function.The current study aims to investigate the functional significance of deacetylase activity of SIRT1 in heart.Here we show that the early postnatal hearts expressed the highest level of SIRT1deacetylase activity compared to adult and aged hearts.We generated transgenic mice with cardiac-specific expression of a dominant-negative form of the human SIRT1(SIRT1H363Y),which represses endogenous SIRT1 activity.The transgenic mice displayed dilated atrial and ventricular chambers,and died early in the postnatal period.Pathological,echocardiographic and molecular phenotype confirmed the presence of dilated cardiomyopathy.Terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling analysis revealed a greater abundance of apoptotic nuclei in the hearts of transgenic mice.Furthermore,we show that cardiomyocyte apoptosis caused by suppression of SIRT1 activity is,at least in part,due to increased p53acetylation and upregulated Bax expression.These results indicate that dominant negative form of SIRT1(SIRT1H363Y)overexpression in mouse hearts causes cardiomyocyte apoptosis and early-onset heart failure,suggesting a critical role of SIRT1 in preserving normal cardiac development during the early postnatal period.展开更多
文摘目的研究心脏发育相关基因心肌转录因子NKX2.5和锌指转录因子GATA4在先天性心脏病(CHD)的相互作用关系。方法构建基因NKX2.5和GATA4真核表达质粒及脑钠肽启动子荧光素酶报告基因表达质粒,真核表达质粒经转染后,利用免疫共沉淀技术证明基因NKX2.5和GATA4两者是否有相互作用,通过荧光素酶分析技术分析基因NKX2.5和GATA4对脑钠肽启动子序是否存在协同激活作用。结果 p CMV-HA-NKX2.5与Pre-immune作用后蛋白表达量0,与Anti-Myc作用后蛋白表达量为3.63±1.23,与Input作用后蛋白表达量为2.95±1.05,NKX2.5可将GATA4沉淀下来;p CMV-Myc-GATA4与Pre-immune作用后蛋白表达量0,与Anti-Myc作用后蛋白表达量为5.63±2.06,与Input作用后蛋白表达量为5.75±2.86,GATA4可将NKX2.5沉淀下来;脑钠肽(BNP)启动子荧光表达质粒与两者共转染比分别单独转染NKX2.5和GATA4对脑钠肽启动子的激活作用更强。结论 NKX2.5和GATA4之间具有相互作用,在心脏发育过程中起着重要的协同作用。
基金supported by the National Natural Science Foundation of China(31271227,81161120551)the National Basic Research Program of China(2011CB503902)
文摘SIRT1,a mammalian ortholog of yeast silent information regulator 2(Sir2),is an NAD+-dependent protein deacetylase that plays a critical role in the regulation of vascular function.The current study aims to investigate the functional significance of deacetylase activity of SIRT1 in heart.Here we show that the early postnatal hearts expressed the highest level of SIRT1deacetylase activity compared to adult and aged hearts.We generated transgenic mice with cardiac-specific expression of a dominant-negative form of the human SIRT1(SIRT1H363Y),which represses endogenous SIRT1 activity.The transgenic mice displayed dilated atrial and ventricular chambers,and died early in the postnatal period.Pathological,echocardiographic and molecular phenotype confirmed the presence of dilated cardiomyopathy.Terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling analysis revealed a greater abundance of apoptotic nuclei in the hearts of transgenic mice.Furthermore,we show that cardiomyocyte apoptosis caused by suppression of SIRT1 activity is,at least in part,due to increased p53acetylation and upregulated Bax expression.These results indicate that dominant negative form of SIRT1(SIRT1H363Y)overexpression in mouse hearts causes cardiomyocyte apoptosis and early-onset heart failure,suggesting a critical role of SIRT1 in preserving normal cardiac development during the early postnatal period.
