吡格列酮对糖尿病大鼠血管钙化的影响及机制

The Effect and Mechanism of Pioglitazone on Vascular Calcification in Diabetic Rats

目的研究吡格列酮对糖尿病大鼠血管钙化的影响及其可能机制。方法将36只SD雄性大鼠随机平均分为6组:对照组、糖尿病组、钙化组、糖尿病+钙化组、钙化+吡格列酮组、糖尿病+钙化+吡格列酮组;建立大鼠血管钙化模型(维生素D3+华法林)和糖尿病模型(链尿佐菌素);并对血管组织进行Von Kossa染色、钙含量和碱性磷酸酶活性检测,qRT-PCR检测mRNA表达,免疫组织化学法检测骨保护素蛋白表达。结果钙化组血管平滑肌细胞及其间质内有大量黑色颗粒沉积;糖尿病+钙化组较糖尿病组和钙化组血管组织钙含量、碱性磷酸酶活性分别升高3.63倍、1.35倍和3.69倍、1.30倍(P<0.05),骨保护素mRNA含量及其蛋白表达降低(P<0.05);糖尿病+钙化+吡格列酮组较糖尿病+钙化组钙含量、碱性磷酸酶活性分别下调13.70%、18.04%(P<0.05),骨保护素mRNA含量及其蛋白表达升高(P<0.05)。结论吡格列酮可以减轻血管钙化程度并上调骨保护素mRNA含量及蛋白表达,骨保护素可能是抑制血管钙化主要因素之一。

Aim To explore the effect and mechanism of pioglitazone on vascular calcification （VC） in diabetic rats. Methods Rat model of vascular calcification and diabetes （DM） was established by injection of vitamin D3 plus warfarin and streptozocin（STZ）. Thirty six ten-week-old male SD rats were randomely divided into six groups： control group, DM group, VC group, VC ＋ DM group, VC ＋ PIO group, VC ＋ DM ＋ PIO group. Calcification was confirmed by Von Kossa staining, and calcium content and alkaline phosphatase （ALP） activity of the vascular tissue were measured. The expression of osteoprotegerin （OPG） mRNA and protein were examined by qRT-PCR and immunohistochemistry. Results Massive black granules were observed in the vascular smooth muscle ceils and interstitial tissue by Von Kossa staining in VC group and VC ＋ DM group. Calcium content and ALP activity of VC ＋ DM group were 3.63 times and 1.35 times higher than DM group, and 3.69 times and 1.30 times（P 〈0.05）higher than VC group, but the expression of OPG mRNA and protein were reduced（P 〈 0. 05）. Calcium content and ALP activity of VC ＋ DM ＋ PIO group decreased 13.70% and 18.04% than VC ＋ DM group （P 〈 0.05 ）, but the expression of OPG mRNA and protein increased （P 〈 0.05）. Conclusion Pioglitazone can reduce the degree of vascular calcification and increase the expression of OPG mRNA and protein. OPG is likely to be one of the main factors of inhibiting vascular calcification.