脱氢紫堇碱在心肌细胞钙调控中的作用  

The effect of dehydeocorydaline on calcium handing in hypoxia cardiomyocytes

作　　者：赵昕[1] 汤浩[2] 韩雅玲[1] 闫承慧[1] 

机构地区：[1]沈阳军区总医院全军心血管病研究所心内科,辽宁110016 [2]中国医科大学基础医学院生理教研室

出　　处：《中华高血压杂志》2011年第1期75-80,共6页Chinese Journal of Hypertension

摘　　要：背景已有动物实验表明脱氢紫堇碱(DHC)可能通过阻止心肌细胞内钙超载,提高心肌细胞的自我保护作用,但还没有相关实验阐明DHC调控心肌细胞保护的分子机制。目的探讨DHC对心肌细胞内Ca2+超负荷及Ca2+调控相关蛋白的表达变化。方法采用逆转录聚合酶链反应(RT-PCR)方法对心肌细胞Ca2+调控相关蛋白,包括钙三磷酸腺苷酶(Ca2+-ATPase)、磷酸受钠蛋白(PLB)、斯里兰卡肉桂碱受体2(RYR2)、L型钙通道和肌集钙蛋白(CASQ)的mRNA在转录水平的改变进行了检测,在此基础上,又用western blot法做蛋白表达水平的检测。结果缺氧导致心肌细胞的Ca2+-ATPase、PLB、L型钙通道和CASQ的mRNA转录水平明显减低(P<0.01),而RYR2的mRNA转录水平却升高了(P<0.05)。DHC能使正常、缺氧心肌细胞的RYR2转录表达水平明显减低40%、10%,但CASQ却明显增加36%、82%(P<0.01)。结论心肌细胞的Ca2+-ATPase、CASQ、L型钙通道、PLB和RYR2的表达异常可能是缺氧引起心肌细胞内Ca2+超负荷的分子机制;DHC对缺氧心肌细胞的保护作用与其降低正常和缺氧心肌细胞RYR2及增加CASQ基因转录和蛋白表达有关。Background Ca^2＋ homeostasis plays an important role in myocardial cell injury induced by hypoxia,and prevention of intracellular Ca^2＋ overload is a key process for cardioprotection.It has been reported that dehydeocorydaline（DHC）prevent intracellular calcium overload and protect cardiomyocytes against anoxia injury.However,the detailed mechanism of DHC on cardioprotection remains unclear.Objective To investigate whether DHC protects cardiomyocytes against hypoxia-induced injury by regulating Ca^2＋ homeostasis.Methods The mRNA and protein expression of the calcium handling genes such as（SR）Ca^2＋-ATPase,L-type calcium channel,ryanodine receptor,calsequestrin and phospholamban were measured respectively by reverse transcription-polymerase chain reaction（RT-PCR）and Western blotting in hypoxia-induced myocardiac cells induced in vitro.Furthermore,the immunoprecipitate（IP）and immunofluorescence staining were used to evaluate the interaction between the ryanodine receptor and calsequestrin.Results The mRNA expressions of SR Ca^2＋-ATPase,calsequestrin,phospholamban and cardiac L-type calcium channel were significantly decreased in primary cultured myocardiac cells under hypoxia condition（P〈0.01）.In contrast,the mRNA level of ryanodine receptor was obviously increased（P〈0.05）.Furthermore,Western blotting demonstrated that expression of calsequestrin was markedly elevated 82% in hypoxia myocardiac cells or 36% in normal cells when treated by DHC（P〈0.01）,whereas ryanodine receptor was observed to reduce 10% in hypoxia myocardiac cells or to 40% in normal cells.Conclusion Down-regulation expressions of cardiac（SR）Ca^2＋-ATPase,L-type calcium channel,calsequestrin and phospholamban might be the basis of intracellular Ca^2＋ overload in hypoxia myocardiac cells.Moreover,DHC exerts its cardioprotection by modulating the expression of ryanodine receptor and calsequestrin.

关 键 词：钙调相关蛋白 缺氧 心肌细胞内游离钙 脱氢紫堇碱 

分 类 号：R541.4[医药卫生—心血管疾病]