GRK5与持久兴奋βAR诱导心肌肥厚氧化应激途径的关系  

Relationship of GRK5 and oxidative stress in sustained βAR-stimulated cardiac hypertrophy

作　　者：李锐[1] 李丹丹[1] 杨霞[2] 杨冰[3] 屈扬扬[1] 张玲[1] 

机构地区：[1]天津医科大学基础医学院生理学与病理生理学系,300070 [2]天津市胸科医院病理科,300350 [3]天津医科大学基础医学院细胞生物学系

出　　处：《国际生物医学工程杂志》2015年第4期206-210,I0004,共6页International Journal of Biomedical Engineering

基　　金：天津市自然科学基金资助项目（15JcYBJC25400）;教育部留学回国人员科研启动基金资助项目

摘　　要：目的探讨持久兴奋B受体诱导病理性心肌肥厚机制中，氧化应激水平升高与GRK5之间的关系。方法雄性sD大鼠（180～200g），按照随机原则分为对照组（CTRL）、N-乙酰半胱氨酸（NAC）组（CTRL＋NAC）、异丙肾上腺素（ISO）组（ISO）及ISO注射辅以NAC组（ISO＋NAC），6只／组。ISO组通过腹腔注射给予ISO3mg／（kg·d），对照组给予腹腔注射等量生理盐水，NAC组通过饮用水给药15g/L，共2周，分别检测各组大鼠血压、心脏质量指数（HMI）、心肌组织学变化、心肌NOX4及GRK5的表达变化。结果与CTRL组比较，ISO组大鼠HMI明显升高[（3．99±0．10）mg／g VS（3．31±0．13）mg／g]，其差异有统计学意义（P〈0．05），心肌横截面积明显增大[（11117．00±387．57）μm^2vs（4572．23±176．39）μm^2]，其差异有统计学意义（P〈0．05）；ISO＋NAC组大鼠的HMI[（3．56±0．12）mg／g]、心肌细胞横截面积[（6160．33±141．44）μm2]均明显低于ISO组大鼠，其差异均具有统计学意义（P〈0．05）；ISO组大鼠心肌NOX4蛋白表达水平明显高于CTRL组（10．59±1．61VS4．35±1．65），其差异具有统计学意义（P〈0．05），NAC明显降低了ISO诱导的NOX4表达增加（4．67±1．25VS10．59±1．61），其差异具有统计学意义（P〈0．05）；用Westrenblot、免疫组化技术检测心肌GRK5表达情况，结果显示ISO组与CTRL组、ISO＋NAC组与ISO组差异均无统计学意义（黔0．05）；同时RT—qPCR技术检测心肌GRK5mRNA表达水平亦发现ISO与CTRL、ISO＋NAC与ISO组的差异均无统计学意义（P〈0．05）；鼠尾动脉血压测量结果显示在4组实验动物间差异均无统计学意义（P〉0．05）；NAC组各项指标与CTRL组大鼠无差异。结论持久兴奋BAR诱发病理性心肌肥厚机制中，GRK5可能未参与氧化应激通路对致肥厚因子的调节，有待进一步体外实验证明。Objective To explore the role of GRK5 in sustained 13 adrenergic receptor （13AR）-stimulated increased levels of oxidative stress. Methods Male SD rats （180-200 g） were separated into 4 groups according to the random principal： control group （CTRL）, control with NAC supplement group （CTRL＋NAC）, ISO treated group （ISO）, and ISO treated with NAC supplement group （ISO＋NAC）, with 6 rats in each group. ISO group was treated by method of intraperitoneal injection for 3 mg/（kg, d）. CTRL rats received same volume of physiological saline by same method, while NAC was treated by supplement in drinking water for 15 g/L per day. After 2 weeks of treatment, BP, heart mass index （HMI）, histology changes, expression of NOX4 and GRK5 of myocardium was examined. Results HMI of ISO rats was significantly higher than that of the CTRL group [（3.99±0.10 vs 3.31±0.13） mg/g, P〈0.05], and the cardio-myocyte cross-sectional area of ISO group was also significantly increased compared with CTRL group [（11 117.00±387.57 vs 4572.23±176.39） μm, P〈0.05]. ISO＋NAC significantly reduced the ISO-induced increases of heart weight index （3.56±0.12 mg/g, vs ISO, P〈0.05） and myocyte cross-sectional area （6160.33±＋141.44μm^2, vs ISO, P〈0.05）. The immunohistochemistry results showed that the expression of myocardial NOX4 of ISO group was significantly higher than that of CTRL group [（10.59±1.61 vs 4.35±1.65）, P〈0.05], and NAC reduced the ISO induced NOX4 expression increase [（4.67±1.25 vs 10.59±1.61）, P〈0.05]. Western Blot and immunohistochemistry were used to detect the protein expression of myocardial GRKS. Both results showed that there were no significant differences between ISO and CTRL, ISO＋NAC and ISO group （P〉0.05）. RT-qPCR detected no significant differences of myocardial GRK5 mRNA expression between ISO and CTRL, ISO＋NAC and ISO groups （P〉O.05）. Arterial blood pressure showed no significant difference among the 4 groups of rats （P〉.05�

关 键 词：心肌肥厚 G蛋白偶联受体激酶 氧化应激 N-乙酰半胱氨酸 

分 类 号：Q469[生物学—生理学] R54[医药卫生—心血管疾病]