血管紧张素Ⅱ(angiotensin Ⅱ,Ang Ⅱ)和降钙素基因相关肽(calcitonin gene-related peptide,CGRP)在血管的损伤和保护中起重要作用。为了探讨CGRP受体成分蛋白(receptor component protein,RCP)在CGRP~AngⅡ对血管平滑肌细胞(vascular smooth muscle cell,VSMC)血管过氧化物酶1(vascular peroxidase-1,VP01)表达调控中的作用及机制,本研究采用体外培养鼠源性A10血管平滑肌细胞株(A10VSMC),给予CGRP或/和AngⅡ刺激,并用小干扰RNA(siRNA)干扰细胞RCP基因的表达,WesternBlot检测RCP以及VP01蛋白表达水平;RT-PCR检测RCP及VP01 mRNA的表达水平。结果显示,在静止期野生型A10VSMC,CGRP和AngⅡ能分别上调RCP和VP01蛋白和mRNA表达(均P〈0.05),但CGRP预孵育细胞后,AngⅡ诱导的RCP和VPO1蛋白表达降低(均P〈0.05);与野生型组比较,VPO1在所有RCP基因干扰组的表达均显著降低(均P〈0.01)。同时,在RCP基因干扰条件下,和对照组相比,CGRP处理组VPO1蛋白的表达显著增加,而AngⅡ组没有明显变化;和AngⅡ组相比,CGRP与AngⅡ联合作用显著增虽VPO1蛋白表达,但这种作用能被抗氧化酶Catalase所抑制(P〈0.05)。以上结果提示,RCP可能参与CGRP或AngⅡ诱导的VP01蛋白表达;RCP可能在介导CGRP和AngⅡ受体共同调控VP01表达的信号转导整合中起一定作用。
Angiotensin Ⅱ (Ang Ⅱ) and calcitonin gene-related peptide (CGRP) play important roles in vascular injury and protection. In order to determine the role of CGRP receptor component protein (RCP) in signal transduction whereby CGRP and Ang Ⅱ mediate the expression of vascular peroxidase-1 (VPO1) in vascular smooth muscle cell (VSMC), mouse derived A10 vascular smooth muscle cell line (A10VSMC) was cultured with CGRP or/and Ang Ⅱ in vitro. RCP-specific small interference RNA (siRNA-RCP) was used to silence oligonucleotide sequence. Western blot and RT-PCR were used to determine the protein and mRNA expressions of RCP and VPO 1, respectively. The results showed that the expressions of RCP and VPO 1 were increased in the presence of CGRP or Ang Ⅱ in the quiescent A10VSMC. But the protein expressions of RCP and VPO 1 induced by Ang Ⅱ were decreased by pretreatment of CGRP (P 〈 0.05). The expressions of VPO1 were decreased in all the groups treated with siRNA-RCP, compared with those of wide-type counterparts. Meanwhile, the expression of VPO1 was significantly induced by CGRP but not Ang Ⅱ in the siRNA-RCP treated A10VSMCs. Ang II in combination with CGRP increased the protein expression of VPO1 in the siRNA-RCP-transfected cells, com- pared with Ang II alone, and this effect could be abolished by catalase. The results suggest that RCP may play an important role in the integration of signal transduction whereby CGRP and Ang 1I receptors jointly regulate VPO 1 expression in VSMC.