Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarge...Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.展开更多
本文旨在探究富含天冬氨酸尾1的单通道膜蛋白(Single-pass Membrane Protein With Aspartate Rich Tail1,Smdt1)对C3H10T1/2细胞增殖和成脂分化的调控效应。本研究将Smdt1基因的过表达和干扰载体转染至C3H10T1/2细胞模型,采用qPCR方法...本文旨在探究富含天冬氨酸尾1的单通道膜蛋白(Single-pass Membrane Protein With Aspartate Rich Tail1,Smdt1)对C3H10T1/2细胞增殖和成脂分化的调控效应。本研究将Smdt1基因的过表达和干扰载体转染至C3H10T1/2细胞模型,采用qPCR方法量化了增殖和成脂分化关键基因的表达水平变化,利用EdU染色检测细胞增殖活力,油红O染色方法鉴定脂滴积累的状态;进一步通过String database、Bio GRID、Int Act、GeneMANIA、DAVID和Genecard数据库构建Smdt1蛋白互作网络图。结果显示,在C3H10T1/2细胞中过表达Smdt1,极显著提升了增殖标志基因Pcna、Ki67、Cdk1及Cdk4的表达,EdU阳性细胞比例反映了细胞增殖速率加快;Smdt1极显著促进成脂分化关键基因Pparγ、Fabp4、-Adipoq的表达量,显著促进了Cebpα、Cebpβ的表达量,脂滴数量变多。在C3H10T1/2细胞体系中,干扰Smdt1,与增殖紧密相关的标志基因,包括Ki67、Pcna及Cdk1,其表达水平极显著降低,Cdk4的表达也呈现显著降低的趋势,反映在EdU增殖检测中,阳性细胞数量明显减少,细胞增殖活性受到抑制。进一步干扰Smdt1后,成脂分化途径的关键调控基因Cebpα、Pparγ、Cebpβ、Fabp4、Adipoq的表达均极显著降低,细胞内脂滴的数量也显著减少,细胞成脂分化能力削弱。蛋白功能预测发现,Smdt1能够与Mcu相互作用,参与线粒体钙离子转运、摄取和稳态。本研究发现Smdt1可以促进C3H10T1/2细胞增殖和成脂分化,为脂肪沉积的研究提供了新的方向。展开更多
文摘Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.
文摘本文旨在探究富含天冬氨酸尾1的单通道膜蛋白(Single-pass Membrane Protein With Aspartate Rich Tail1,Smdt1)对C3H10T1/2细胞增殖和成脂分化的调控效应。本研究将Smdt1基因的过表达和干扰载体转染至C3H10T1/2细胞模型,采用qPCR方法量化了增殖和成脂分化关键基因的表达水平变化,利用EdU染色检测细胞增殖活力,油红O染色方法鉴定脂滴积累的状态;进一步通过String database、Bio GRID、Int Act、GeneMANIA、DAVID和Genecard数据库构建Smdt1蛋白互作网络图。结果显示,在C3H10T1/2细胞中过表达Smdt1,极显著提升了增殖标志基因Pcna、Ki67、Cdk1及Cdk4的表达,EdU阳性细胞比例反映了细胞增殖速率加快;Smdt1极显著促进成脂分化关键基因Pparγ、Fabp4、-Adipoq的表达量,显著促进了Cebpα、Cebpβ的表达量,脂滴数量变多。在C3H10T1/2细胞体系中,干扰Smdt1,与增殖紧密相关的标志基因,包括Ki67、Pcna及Cdk1,其表达水平极显著降低,Cdk4的表达也呈现显著降低的趋势,反映在EdU增殖检测中,阳性细胞数量明显减少,细胞增殖活性受到抑制。进一步干扰Smdt1后,成脂分化途径的关键调控基因Cebpα、Pparγ、Cebpβ、Fabp4、Adipoq的表达均极显著降低,细胞内脂滴的数量也显著减少,细胞成脂分化能力削弱。蛋白功能预测发现,Smdt1能够与Mcu相互作用,参与线粒体钙离子转运、摄取和稳态。本研究发现Smdt1可以促进C3H10T1/2细胞增殖和成脂分化,为脂肪沉积的研究提供了新的方向。
