血管紧张素Ⅱ对大鼠肺微血管内皮细胞APJ mRNA和Apelin mRNA表达的影响

Effect of angiotension Ⅱ on Apelin mRNA and APJ mRNA expression in pulmonary microvascular endothelial cells in rats

目的探讨血管紧张素Ⅱ（AngⅡ）对肺微血管内皮细胞APJ mRNA和Apelin mRNA表达的影响。方法培养并鉴定24h新生SD大鼠肺微血管内皮细胞，取2-4代培养细胞，细胞密度5×10^5个／ml，培养至80％融合后，进行药物干预。第一部分实验分为5组（n=4）：加入AngⅡ至终浓度分别为10^-9mol／L（Ⅱ组）、10^-8mol／L（Ⅲ组）、10^-7mol／L（Ⅳ组）、10^-6mol／L（Ⅴ组），Ⅰ组不加入AngⅡ，24h后采用RT-PCR技术测定Apelin mRNA和APJ mRNA的表达水平。第二部分实验分为6组（n=4）：加入AngⅡ至终浓度为10^-7mol／L，分别在孵育即刻（Ⅰ组）、1h（Ⅱ组）、6h（Ⅲ组）、12h（Ⅳ组）、24h（Ⅴ组）、48h（Ⅵ组）时，采用RT-PCR技术测定Apelin mRNA和APJ mRNA的表达水平。结果第一部分实验结果：与Ⅰ组比较，Ⅱ组Apelin mRNA表达上调，APJ mRNA表达下调，Ⅲ组～Ⅴ组Apelin mRNA和APJ mRNA表达下调（P〈0．05或0．01），与Ⅱ组比较，Ⅲ组～Ⅴ组Apelin mRNA和APJ mRNA表达下调，呈浓度依赖性（P〈0．01）。第二部分实验结果：Apelin mRNA在10^-7mol/L AngⅡ孵育6h内表达上调，孵育1h时达高峰（P〈0．05或0．01），孵育6h后Apelin mRNA表达下调，且呈时间依赖性（P〈0．01）；而APJ mRNA在孵育12h后呈时间依赖性持续下调（P〈0．01）。结论AngⅡ呈浓度和时间依赖性地下调Apelin mRNA和APJ mRNA的表达，可能是其参与肺微血管内皮细胞损伤的发生机制。

Objective To investigate the effects of angiotensin Ⅱ （Ang Ⅱ ） on the Apelin mRNA and APJ mRNA expression in pulmonary microvascular endothelial cells （PMVECs） in rats. Methods Pulmonary microvascular endothelial cells obtained from 24 h old neonatal SD rats were cultured in DMEM liquid culture medium. The 2nd-4th generation PMVECs were inoculated on 6-well plates （5 × 10^5 ）. The experiment was performed in two parts. In part Ⅰ different concentration of AngⅡ 0, 10^-9 , 10^-8 , 10^-7 , 10^-6mol/L （group Ⅰ - Ⅴ ） were added into the PMVECs. The expression of Apelin mRNA and APJ mRNA was determined at 24 h after addition of AngⅡ by RT-PCR. In part Ⅱ the cells were exposed to 10^-7mol/L AngⅡ . The expression of Apelin mRNA and APJ mRNA was determined immediately and at 1, 6, 12, 24, 48 h（group Ⅰ -Ⅵ ） after addition of Ang Ⅱ by RT-PCR. Results In part Ⅰ Apelin mRNA expression was significantly higher in group Ⅱ （Ang Ⅱ 10^-9 mol/ L） but lower in group Ⅲ-Ⅴ （AngⅡ 10^-8 s, 10^-7, 10^-6 mol/L） than in group Ⅰ （control, AngⅡ 0 mol/L）. The APJ mRNA expression was significandy lowered in group Ⅱ -Ⅴ in a dose-dependent manner as compared with control group （group Ⅰ ） . In part Ⅱ both Apelin mRNA and APJ mRNA expression exhibited a bi-phasic response to Ang Ⅱ 10^-7 mol/L, increased at first and was then decreasing with time. The Apelin mRNA and APJ mRNA expression reached the peak at 1 h of incubation with Ang Ⅱ respectively. Conclusion Ang Ⅱ decreases both Apelin mRNA and APJ mRNA expression in PMVECs in a dose and time dependent manner. The down-regulation of Apelin mRNA and APJ mRNA expression may be involved in the mechanism of injury to PMVECs.