Ishibashi Toshiyuki, Nagata Kenji, Ohkawara Hiroshi, Sakamoto Takayuki, Yokoyama Keiko, Shindo Joji, Sugimoto Koichi, Sakurada Sotaro, Takuwa Yoh, Teramoto Tamio, Maruyama Yukio
First Department of Internal Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima, 960-1295, Japan.
Biochim Biophys Acta. 2002 Jun 12;1590(1-3):123-30. doi: 10.1016/s0167-4889(02)00201-x.
Increased production of plasminogen activator inhibitor-1 (PAI-1) in plaques plays a role in the pathogenesis of atherosclerosis. This study was conducted to investigate the effect of blockade of Rho/Rho-kinase signaling on the synthesis of PAI-1 in cultured human peripheral blood monocytes. HMG-CoA reductase inhibitors (statins) and inhibitors of Rho and Rho-kinase were added to monocyte cultures. The levels of PAI antigen and mRNA were determined by Western blotting and RT-PCR, respectively, and PAI-1 expression was assessed by immunohistochemistry. We performed pull-down assays to determine the activity of Rho by measuring the GTP-bound form of Rho A. In unstimulated and lipopolysaccharide (LPS)-stimulated cultured monocytes, statins reduced the levels of PAI-1 antigen and mRNA. The suppressive effects of statins on PAI-1 synthesis were reversed by geranylgeranylpyrophosphate (GGPP) and were mimicked by C3 exoenzyme. Immunohistochemistry confirmed the role of lipid modification by GGPP in suppressive effect of statins in PAI-1 synthesis. Pull-down assays demonstrated that statins decreased the levels of the GTP-bound form of Rho A. Our findings suggest that statins decrease the activity of Rho by inhibiting geranylgeranylation. Moreover, Rho-kinase inhibitors, Y-27632 and fasudil, suppressed the synthesis of PAI-1 in this culture system. We show that inhibition of Rho/Rho-kinase signaling downregulates the synthesis of PAI-1 in human monocytes.
斑块中纤溶酶原激活物抑制剂 -1（PAI -1）产量增加在动脉粥样硬化发病机制中起作用。本研究旨在探讨阻断Rho/Rho激酶信号对培养的人外周血单核细胞中PAI -1合成的影响。将HMG -CoA还原酶抑制剂（他汀类药物）以及Rho和Rho激酶抑制剂添加到单核细胞培养物中。分别通过蛋白质印迹法和逆转录 -聚合酶链反应测定PAI抗原和mRNA水平，并通过免疫组织化学评估PAI -1表达。我们进行了下拉实验，通过测量Rho A的GTP结合形式来确定Rho的活性。在未刺激和脂多糖（LPS）刺激的培养单核细胞中，他汀类药物降低了PAI -1抗原和mRNA水平。香叶基香叶基焦磷酸（GGPP）逆转了他汀类药物对PAI -1合成的抑制作用，而C3外切酶模拟了这种作用。免疫组织化学证实了GGPP的脂质修饰在他汀类药物对PAI -1合成的抑制作用中的作用。下拉实验表明，他汀类药物降低了Rho A的GTP结合形式的水平。我们的研究结果表明，他汀类药物通过抑制香叶基香叶基化降低Rho的活性。此外，Rho激酶抑制剂Y -27632和法舒地尔在该培养系统中抑制了PAI -1的合成。我们表明，抑制Rho/Rho激酶信号可下调人单核细胞中PAI -1的合成。
