TGF-β和ERK1/2在自发性高血压大鼠主动脉中的表达

Expression of Transforming Growth Factor - beta 1 and Extracellular Signal Regulated Kinase1/2 in the Aorta of Spontaneously Hypertensive Rats

目的探讨细胞外信号调节激酶(ERK1/2)和转化生长因子-β(TGF-β1)在自发性高血压大鼠(SHR)主动脉血管平滑肌细胞(VSMC)和血管内皮细胞(EC)中的表达及其意义。方法将SHR分为4、8、16和20周龄组,采用免疫组化和Western blot方法检测主动脉血管EC和VSMC中ERK1/2和TGF-β1蛋白的表达。结果 SHR从8周龄开始血压升高,20周龄组收缩压达到(180±21)mmHg;Western blot检测显示,ERK1/2和TGF-β1在SHR16和SHR20周龄组VSMC和EC中的表达与4周龄组相比增高(P<0.05),且ERK1/2和TGF-β1蛋白积分光密度值与血压呈正相关;ERK1/2免疫组化结果显示,在SHR16和20周龄组,主动脉中内皮细胞阳性率分别为72.69%和70.14%、VSMC阳性率分别为35.01%和28.54%,明显高于SHR4周龄组(P<0.01);在SHR主动脉中,TGF-β1免疫组化表达均为阴性。结论在SHR动脉血管平滑肌细胞和内皮细胞中ERK1/2和TGF-β1的表达随着血压的增高呈现增加的趋势,推测ERK1/2和TGF-β1相互共同作用参与主动脉血管改变。

Objective To explore the expression and significance of extracellular signal -regulated kinase1/ 2 ,transforming growth factor- β1 in the VSMC and EC of spontaneously hypertensive rats （SHR）. Methods SHR were divided into 4 groups according to their ages （4 -week old, 8 -week old, 16 -week old and 20 -week old）. The expression of ERK1/2, TGF- β1 in the aorta of the 4 groups were tested by western blot and immunohistochemistry. Results SHRs＇ systolic blood pressure significantly increased since 8 weeks and sysotic blood pressure was （180 ±21）mmHg in 20 weeks old SHR. Western blot assays showed that ERK1/2 and TGF - β1 in EC and VSMC of SHR16 and SHR20 were significantly higher than those in SHR4 （P 〈 0. 05）. A positive correlation was found between the optical density of ERKI/2 and TGF -β1 and the blood pressure. Immunohistochemistry assays showed that the positive rate of ERK1/2 in EC of SHR16 and SHR20 was 72.69% and 70.14% respectively, and in VSMC was 35.01% and 28.54% ,both of which were higher than those of SHR4 （P 〈 0.05 ）. The expression of TGF - β1 were all negative in aorta of SHR. Conclusion For SHR, the level of the expression of ERK1/2 and TGFβ1 increases along with the blood pressure level. It is extrapolated that ERK1/2 and TGF -β1 participated in aorta lesion.