血管紧张素Ⅱ受体1型-钙调神经磷酸酶信号通路对乳鼠肥大心室肌细胞L型钙离子流的调控作用  

Regulation of AT1R-calcineurin signaling pathway on L-type calcium current of hypertrophic ventricular myocytes from neonatal rats

作　　者：杨英[1] 夏桂玲 杨龙[1] 何炯红[1] 霍照美 郭楚娴 YANG Ying;XIA Guiling;YANG Long;HE Jionghong;HUO Zhaomei;GUO Chuxian(Department of Cardiology,Guizhou Provincial People′s Hospital,Guiyang 550002,China)

机构地区：[1]贵州省人民医院心内科,贵阳550002

出　　处：《国际心血管病杂志》2021年第5期296-300,共5页International Journal of Cardiovascular Disease

基　　金：贵州省科技计划项目(黔科合基础[2019]1205);贵州省科技平台及人才团队计划(黔科合平台人才[(2017)5405])。

摘　　要：目的:探讨血管紧张素Ⅱ受体1型(AT1R)-钙调神经磷酸酶(CaN)信号通路对乳鼠肥大心室肌细胞L型钙离子通道电流(I_(Ca-L))和动作电位时程(APD)的调控作用。方法:分离获得1 d龄SD乳鼠心室肌细胞,分为4组,对照组不予干预;苯肾上腺素(PE)组常规培养1 h后加入PE(终浓度0.1 mmol/L)干预24 h;氯沙坦(Los)+PE组先予Los(终浓度1μmol/L)干预1 h,再予PE干预24 h;环孢素A(CsA)+PE组先予CsA(终浓度0.25μg/mL)干预1 h,再予PE干预24 h。实时荧光定量聚合酶链反应检测肌球蛋白重链β(β-MHC)的mRNA表达水平。Western blot检测CaN A亚基β亚单位(CaNAβ)蛋白表达水平。全细胞膜片钳技术检测细胞膜I_(Ca-L)和单细胞APD。结果:PE组β-MHC的mRNA表达水平和CaNAβ的蛋白表达水平均高于对照组;I_(Ca-L)电流密度峰值绝对值[(-18.23±1.44)pA/pF对(-10.78±1.87)pA/pF]、50%APD[(25.7±2.4)ms对(15.3±3.0)ms]和90%APD[(197.6±10.6)ms对(91.8±21.3)ms]均高于对照组(P均<0.05)。Los+PE组β-MHC的mRNA表达水平和CaNAβ的蛋白表达水平均低于PE组;I_(Ca-L)电流密度峰值绝对值[(-14.02±1.51)pA/pF]、50%APD[(20.4±2.9)ms]和90%APD[(128.7±18.5)ms]均低于PE组(P均<0.05)。CsA+PE组β-MHC的mRNA表达水平和CaNAβ的蛋白表达水平均低于PE组;I_(Ca-L)电流密度峰值绝对值[(-12.19±1.09)pA/pF]、50%APD[(22.7±1.9)ms]和90%APD[(121.7±15.0)ms]均低于PE组(P均<0.05)。结论:AT1R-CaN信号通路参与乳鼠肥大心室肌细胞I_(Ca-L)和APD的调控。Objective:To investigate the role of angiotensinⅡreceptor 1 type(AT1R)-calcineurin(CaN)signaling pathway in regulating L-type Ca 2+channel current(I_(Ca-L))and action potential duration(APD)of hypertrophic ventricular myocytes from neonatal rats.Methods:The ventricular myocytes were isolated from one-day-old SD rats and cultured for 24 hours,and they were divided into 4 groups depending on the treatment administered.The control group was not intervened;the phenylephrine(PE)group was treated with 0.1 mmol/L PE for 24 hours after cultured for 1 hour;the losartan(Los)+PE group was treated with 1μmol/L Los for 1 hour,and then with 0.1 mmol/L PE for 24 hours;the cyclosporine A(CsA)+PE group was treated with 0.25μmol/L CsA for 1 hour,and then with 0.1 mmol/L PE for 24 hours.The mRNA expression of myosin heavy chain beta(β-MHC)was detected by real time PCR.The protein expression of theβisoform of the CaN A-subunit(CaNAβ)was assayed by western blot analysis.I_(Ca-L)and action potential were recorded by whole-cell patch clamp technique.Results:The expression levels ofβ-MHC mRNA and CaNAβprotein in PE group were higher than those in control group.The absolute peak value of I_(Ca-L)current density[(-18.23±1.44)pA/pF vs.(-10.78±1.87)pA/pF],50%APD[(25.7±2.4)ms vs.(15.3±3.0)ms]and 90%APD[(197.6±10.6)ms vs.(91.8±21.3)ms]in PE group were higher than those in control group(all P<0.05).The expression levels ofβ-MHC mRNA and CaNAβprotein in Los+PE group were lower than those in PE group.The absolute peak value of I_(Ca-L)current density[(-14.02±1.51)pA/pF],50%APD[(20.4±2.9)ms]and 90%APD[(128.7±18.5)ms]were lower than those in PE group(all P<0.05).The expression levels ofβ-MHC mRNA and CaNAβprotein in CsA+PE group were lower than those in PE group.The absolute value of I_(Ca-L)current density[(-12.19±1.09)pA/pF],50%APD[(22.7±1.9)ms]and 90%APD[(121.7±15.0)ms]were lower than those in PE group(all P<0.05).Conclusions:The AT1R-CaN signaling pathway is involved in the regulation of I_(Ca-L)and APD of hypertrophic

关 键 词：心室肌细胞 钙电流 动作电位 全细胞膜片钳技术 

分 类 号：R542.2[医药卫生—心血管疾病]