缬沙坦和卡托普利对兔血管平滑肌细胞组织因子和组织因子途径抑制物表达及活性的影响

目的观察氧化修饰低密度脂蛋白（ox-LDL）、血管紧张素转换酶抑制剂和血管紧张素受体拮抗剂对血管平滑肌细胞组织因子（TF）和组织因子途径抑制物（TFPI）表达和活性的影响。方法采用组织贴块法培养兔主动脉平滑肌细胞,进行形态学和α-肌动蛋白（actin）免疫组化鉴定。在细胞水平,采用免疫组化、免疫荧光法检测ox-LDL和缬沙坦对TF、TFPI蛋白表达的影响,激光共聚焦法检测ox-LDL和缬沙坦对TF蛋白表达的影响,ELISA法检测ox-LDL、缬沙坦和卡托普利对TF、TFPI抗原表达的影响,发色底物法检测ox-LDL、缬沙坦和卡托普利对TF活性的影响,RT—PCR检测ox-LDL和缬沙坦对TF mRNA表达的影响。结果ox-LDL可增加兔血管平滑肌细胞TF抗原活性和mRNA的表达,在mRNA水平调节TF的表达。ox-LDL可降低兔血管平滑肌细胞TFPI抗原的表达。不同浓度的缬沙坦和卡托普利可明显减少ox-LDL刺激的平滑肌细胞TF抗原表达及活性,缬沙坦对TF表达的影响呈浓度依赖性,同时缬沙坦还可明显减少ox-LDL刺激的TF mRNA表达,证明缬沙坦在mRNA水平上调节TF的表达。不同浓度的缬沙坦和卡托普利可增加ox-LDL刺激的血管平滑肌细胞TFPI抗原的表达,缬沙坦对TFPI表达的影响呈浓度依赖性,该结果由ELISA法得出。结论本实验在细胞水平观察到ox-LDL对血管平滑肌细胞TF表达和活性有促进作用,血管紧张素转换酶抑制剂和血管紧张素受体拮抗剂对其有抑制作用,但这两种药对TFPI的表达有促进作用。从一个新的角度说明这两种药对动脉粥样硬化斑块特别是斑块促凝性的影响,它们可能是通过部分调节TF和TFPI的表达水平而发挥作用的。

Effects of valsartan and captopril on expressions and activities of tissue factor and tissue factor pathway inhibitor

Objective To investigate the effects of ox-LDL,ACEI and ARB on expressions and activities of TF and TFPI in VSMC.Methods(1)Rabbit VSMC was cultured by explant-attached method in vitro.(2)The effects of ox-LDL and valsartan on TF and TFPI expressions were analyzed by immunohistochemistry and immunofluorscence.Laser scanning confocal microscopy were applied to analyze the effects of ox-LDL and valsartan on TF expression.The effects of ox-LDL,valsartan and eaptopril on TF and TFPI antigen expressions were analyzed by ELISA.Chromogenic substrate method was used to determine the effects of ox-LDL,valsartan and captopril on TF activity.The effects of ox-LDL and valsartan on TF mRNA expression were analyzed by RT-PCR.Results(1)ox-LDL could upregulate TF antigen,activity and TF expression at mRNA level and downregulate TFPI antigen.(2)Valsartan and captopril could reduce TF antigen and activity in VSMC treated by ox-LDL,and valsartan reduce it in a dose-dependent manner. Valsartan could also attenuate TF expression at mRNA level in VSMC treated by ox-LDL.(3)Using ELISA,valsartan and captopril could also enhance TFPI antigen in VSMC treated by ox-LDL.Conclusion Our study showed upregulated TF and downregulated TFPI expression and activity by ox-LDL and these effects could be reversed by ACEI and ARB indicating a new insight on the antiatherosclerotic effects of ACEI and ARB.