摘要
目的研究泛素蛋白酶体抑制剂MG262对钙调神经磷酸酶信号通路的影响,探讨其抑制心肌细胞肥大的机制。方法在去甲肾上腺素诱导培养的乳鼠肥大心肌细胞中加入MG262,通过Phalloidin染色观察细胞的形态,RNA Dot Blot检测胚胎蛋白基因表达,Western blot检测细胞中钙调神经磷酸酶蛋白含量,免疫荧光标记观察活化T细胞核因子c4(NFATc4)蛋白在细胞内分布。结果去甲肾上腺素使细胞面积增大近1.1倍,胚胎基因心房利钠因子(ANF)、脑钠肽(BNP)、β肌球蛋白重链(β-MHC)的mRNA表达上调,细胞核内NFATc4蛋白表达水平增加。MG262明显抑制去甲肾上腺素诱导的细胞肥大(P<0.05)和ANP、BNP、β-MHC的mRNA表达上调(P<0.05),细胞面积下降了33%;同时MG262使去甲肾上腺素诱导的细胞钙调神经磷酸酶蛋白表达水平下降,抑制NFATc4核内转位。结论 MG262可能通过抑制钙调神经磷酸酶信号通路,减轻心肌细胞肥大。
Aim To demonstrate the mechanisms of proteasome inhibition on norepinephrine（ NE）-induced hypertrophic growth of neonatal rat cardiomyocytes（ NRC） via studying the alteration of calcineurin（ CaN） signaling pathway.Methods Proteasome inhibitor MG262 was cotreated with NE in NRC. Cell size was observed by phalloidin-stained technique. The expression of fetal genes and CaN was detected by using RNA dot blot analysis and Western blot analysis respectively. The fixed cells were immunofluorescence labeled with nuclear factor of activated T cell c4（ NFATc4） and visualized by fluorescence microscopy. Results Fetal genes of atrial natriuretic factor（ ANF）,brain natriuretic peptide（ BNP）and β-myosin heavy chain（ β-MHC） mRNA as well as expression of CaN were upregulated and NFATc4 was predominantly expressed in nucleus on NE induced NRC. However,more than 2. 1 fold NE-induced increase in cardiomyoctyes was markedly supressed by cotreatment with MG262（ P〈0. 05）. NE-induced upregulation of CaN and fetal gene expression was significantly relieved by MG262（ P〈0. 05）. NFATc4 was relocated from nucleus to cytoplasm. Conclusion MG262 attenuates agonist induced cardiomyocyte hypertrophy,at least in part,via inhibiting CaN signaling pathway.
出处
《中国动脉硬化杂志》
CAS
CSCD
北大核心
2014年第8期774-778,共5页
Chinese Journal of Arteriosclerosis
基金
南京市医学科技发展资金资助项目(YKK10078)
