替米沙坦通过上调自发性高血压大鼠视网膜ACE2-Ang-(1-7)-Mas轴减少视网膜血管内皮细胞凋亡

[Telmisartan reduces retina vessel endothelial cell apoptosis via upregulating retinal ACE2-Ang-(1-7)-Mas axis in spontaneous hypertensive rats].

作者信息

Lin Zhenhao, Ni Yunjie, Hou Lianglei, Song Lijuan, Wu Yihao, Hu Huanhuan, Zhang Juhong, Yang Deye

机构信息

Wenzhou Medical University, Wenzhou 325000, China.

Email:

出版信息

Zhonghua Xin Xue Guan Bing Za Zhi. 2015 Jul;43(7):625-30.

PMID:26420325

Abstract

OBJECTIVE

To investigate the effects of angiotensin II (Ang II) antagonist telmisartan on retina vessel endothelial cell apoptosis and its impact on the ACE2-Ang-(1-7)-Mas axis in spontaneous hypertensive rats (SHR).

METHODS

Thirty-six SHR 16 week-old were randomly divided into 3 groups (n = 12 each): SHR, SHRT (telmisartan 10 mg · kg-1 · d-1 by gastric gavage) and SHRTA group (telmisartan 10 mg · kg-1 · d-1 by gastric gavage plus intravenous injection of A-779 0.5 mg · kg-1 · d-1), twelve WKY rats served as normotensive control group. Systolic blood pressure was measured at pre-treatment and 8 weeks later. After 8 weeks, rats were sacrificed, the expression of ACE2 and Mas in retina were analyzed by qRT-PCR, Western blot and Immunohistochemistry, the Ang-(1-7) concentration in serum was measured by ELISA. Specimens were obtained and stained by hematoxylin and eosin, and the morphology of retina vessel was observed. Apoptosis of vessel endothelial cells were determined by using terminal deoxynucleotidyl transferase mediated dUTP nick end labeling method.

RESULTS

The systolic blood pressure of SHR, SHRT and SHRTA groups at baseline were significantly higher than age-matched WKY group (all P < 0.01). Eight weeks later, the systolic blood pressure group was significantly lower in SHRT group than in the SHR group (P < 0.01), this effect was partly reversed in SHRTA group. The retinal ACE2 mRNA and protein expression was significantly lower in SHR group than in WKY and SHRT groups (P < 0.01), which was similar between SHRT group and SHRTA group (P > 0.05). The retinal Mas mRNA and protein expression were significantly lower in SHR group compared to WKY and SHRT groups (all P < 0.01), which was significantly lower in SHRTA group than in the SHRT group (P < 0.05). ELISA results showed that serum Ang-(1-7) protein level was significantly lower in SHR group than in WKY group and SHRT group (both P < 0.05), which was lower in SHRTA group compared to SHRT group. Retinal vessel endothelial cell apoptosis was higher in SHR group than in WKY group, which could be reduced by cotreatment with telmisartan and this beneficial effect could be reversed by A-779.

CONCLUSION

Telmisartan can reduce retinal vessel endothelial cell apoptosis via upregulating the ACE2-Ang-(1-7)-Mas axis.

摘要

目的

探讨血管紧张素II（Ang II）拮抗剂替米沙坦对自发性高血压大鼠（SHR）视网膜血管内皮细胞凋亡的影响及其对ACE2-Ang-(1-7)-Mas轴的作用。

方法

将36只16周龄的SHR随机分为3组（每组n = 12）：SHR组、SHRT组（通过灌胃给予替米沙坦10 mg·kg-1·d-1）和SHRTA组（通过灌胃给予替米沙坦10 mg·kg-1·d-1并静脉注射A-779 0.5 mg·kg-1·d-1），12只WKY大鼠作为正常血压对照组。在治疗前及8周后测量收缩压。8周后，处死大鼠，通过qRT-PCR、蛋白质免疫印迹法和免疫组织化学分析视网膜中ACE2和Mas的表达，采用酶联免疫吸附测定法（ELISA）检测血清中Ang-(1-7)的浓度。获取标本并用苏木精-伊红染色，观察视网膜血管的形态。采用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法测定血管内皮细胞凋亡。

结果

SHR组、SHRT组和SHRTA组基线时的收缩压均显著高于年龄匹配的WKY组（均P < 0.01）。8周后，SHRT组的收缩压显著低于SHR组（P < 0.01），SHRTA组的这种作用部分被逆转。SHR组视网膜ACE2 mRNA和蛋白表达显著低于WKY组和SHRT组（P < 0.01），SHRT组和SHRTA组之间相似（P > 0.05）。SHR组视网膜Mas mRNA和蛋白表达显著低于WKY组和SHRT组（均P < 0.01），SHRTA组显著低于SHRT组（P < 0.05）。ELISA结果显示，SHR组血清Ang-(1-7)蛋白水平显著低于WKY组和SHRT组（均P < 0.05），SHRTA组低于SHRT组。SHR组视网膜血管内皮细胞凋亡高于WKY组，替米沙坦联合治疗可降低凋亡，而A-779可逆转这种有益作用。