降钙素基因相关肽对大鼠血管平滑肌细胞增殖及表型转化的影响

Influence of calcitonin gene-related peptide on proliferation and phenotype transformation of vascular smooth muscle cells

目的:探讨降钙基因相关肽(CGRP)对大鼠血管平滑肌细胞(VSMC)增殖及表型转化的影响,并对VSMC增殖模型的应用价值作出评估。方法:取大鼠主动脉,分成CGRP作用和无CGRP作用2个实验组,体外培养8d,收集血管前24h用BrdU标记。H-E染色和5-BrdU免疫细胞化学染色观察增殖变化;RT-PCR检测高血压相关基因1(HRG-1)和SM22α基因表达。结果:血管中膜可见大量棕黄色标记增殖的细胞核,VSMC明显增生,HRG-1和SM22α mRNA表达明显减少;而加入CGRP共培养组标记的增殖细胞大大减少,也未见有斑块增生,HRG-1和SM22α mRNA表达明显上调。结论:CGRP对VSMC增殖有抑制作用并可使VSMC从合成型向收缩型转化。

Objective： To investigate whether calcitonin gene-related peptide can influence proliferation and phenotype transformation of vascular smooth muscle cells （VSMCs） and to evaluate the organic model. Methods： Artery sgements were cultured in containing CGRP （2 × 10^7 mol/L） and no CGRP culture medium in vitro. BrdU （8 ×10^4 mol/ L） was added into the cultured medium 24 h before collecting sample collection. The proliferated cells were observed with H-E staining and labeled by BrdU with immunocytochemical method, and the mRNA expression of HRG-1 and SM22a was detected by RT-PCR. Results： The proliferated plaques on the cultured artery segments were found. The positive nucleuses of proliferated cells labeled by BrdU were found under microscope. The mRNA expression of HRG- 1 and SM22α was decreased in the aorta segments cultured for 8 d. While the aorta sgements were cultured in containing CGRP culture medium, the proliferated cells of VSMCs labeled by BrdU were obviously decreased, the proliferated plaques were not found and the mRNA expression of HRG-1 and SM22α was significantly increased. Conclusion： The results showed that inbibitory effect of CGRP on VSMC proliferation may up-regulate the expression of HRG-1 and SM22a and change the phenotype of VSMC from synthetic to contractile type. The organic model can be used to offer a favorable experimental platform for the study of proliferated vascular disease.