TSH对血管内皮细胞和平滑肌细胞影响的研究

The effects of TSH on human vascular endothelial cells and smooth muscle cells

目的通过促甲状腺激素（TSH）对人血管内皮细胞和平滑肌细胞影响的研究，探讨TSH在动脉粥样硬化发生发展过程中的作用。方法体外培养人血管内皮细胞和平滑肌细胞，采用MTY法检测TSH对细胞活性的影响，实时荧光定量PCR观察TSH对内皮细胞内皮型一氧化氮合酶（eNOS）、前列环素（PGl2）、内皮素1、纤溶酶原激活物抑制剂1（PAI-1）mRNA水平以及平滑肌细胞表型转换的影响；流式细胞仪检测TSH对平滑肌细胞周期的影响，应用免疫组化、Western印迹检测TSH对平滑肌细胞周期素A、D1以及内皮细胞相关因子的蛋白表达。结果与对照组比较不同浓度TSH作用于内皮细胞后eNOS、PGl2mRNA水平降低，内皮素1、PAI-1 mRNA水平增加（P〈0．05），eNOS蛋白表达水平逐渐降低，而内皮索1蛋白表达水平逐渐增加（P〈0．05）。不同浓度TSH作用于平滑肌细胞后，可以促进平滑肌细胞发生表型转换、促进细胞周期向G2／M期转换，并使细胞周期素D1、A的表达量增加。结论TSH可能损伤血管内皮细胞功能，促进血管平滑肌细胞增殖。

Objective To study the effect of thyroid-stimulating hormone （ TSH ） on human vascular endothelial cells and smooth muscle cells and to explore the roles of TSH in the development of atherosclerosis. Methods Human vascular endothelial ceils and smooth muscle cells were cultured in vitro. MTT method was used to assay the effect of TSH on cell viability. Real-time PCR was used to determine the levels of endothelial nitric oxide synthase （ eNOS）, prostaeyclin （ PGI2 ）, endothelin-1 （ ET-1 ）, plasminagen activator inhibitor （ PAI-1 ） （ mRNA ） in endothelial cells and the phenotype transition of smooth muscle cells. The effect of TSH to the cycle of smooth muscle cells was detected by using flow eytometry. Immunocytochemistry and Western blot were used to investigate the expression of the cell cyclin A, D1, and the expression of endothelial cell associated factors eNOS and ET-1. Results Compared with the control group, eNOS and PGI2 mRNA levels decreased while ET-1 and PAI-1 mRNA levels increased when different eoncentrations of TSH were applied to endothelial cells （ P〈0.05 ）. The level of eNOS protein was decreased gradually while the level of ET-1 protein was gradually increased （ P〈0.05 ）. Different concentrations of TSH applied to smooth muscle cells could promote the transition of cell cycle phase G2 to phase M and increase the expression of cell cyclin A and D1. Conclusion TSH may damage the function of vascular endothelial cells and oromote the oroliferation of smooth muscle cells.