Gao Xinyu, Iwai Masaru, Inaba Shinji, Tomono Yumiko, Kanno Harumi, Mogi Masaki, Horiuchi Masatsugu
Department of Molecular Cardiovascular Biology and Pharmacology, Ehime University Graduate School of Medicine, Shitsukawa, Tohon, Ehime, Japan.
Am J Hypertens. 2007 Nov;20(11):1170-5. doi: 10.1016/j.amjhyper.2007.07.011.
The effect of a calcium channel blocker (CCB) on the expression of monocyte chemoattractant protein (MCP)-1 was explored in inflammatory vascular injury, focusing on the role of nuclear factor (NF)-kappaB.
Vascular injury was induced by cuff placement. Expression of MCP-1 was determined by real-time RT-PCR. NF-kappaB expression and its activity were detected by Western blot and electrophoretic mobility shift assay.
Polyethylene cuff placement around the mouse femoral artery increased MCP-1 expression, together with proliferation of vascular smooth muscle cells and neointimal formation in the injured artery. The content of NF-kappaB was decreased in the cytosolic fraction but increased in the nuclear fraction prepared from the injured artery. In the nuclear fraction, the binding activity of NF-kappaB to the promoter region of MCP-1 was markedly increased. On the other hand, IkappaB content in the cytosolic fraction was decreased in the injured artery after cuff placement, accompanied by an increase in IkappaB kinase (IKK) phosphorylation. Treatment of mice with a CCB, nifedipine, at a dose of 5 mg/kg/day, significantly decreased vascular smooth muscle cell proliferation and neointimal formation without affecting blood pressure. This dose of nifedipine inhibited the increase in MCP-1 expression in the injured artery. Moreover, nifedipine reduced the nuclear content and DNA-binding activity of NF-kappaB in the injured artery. In contrast, the decrease in IkappaB content and the increase in IKK phosphorylation in the cytosolic fraction were attenuated by nifedipine.
These results indicate that MCP-1 expression in inflammatory vascular injury is regulated by activation of NF-kappaB. The results also suggest that nifedipine attenuates MCP-1 expression in the injured artery via inhibition of the nuclear translocation and DNA-binding activity of NF-kappaB, and thereby improves vascular remodeling.
在炎症性血管损伤中，研究钙通道阻滞剂（CCB）对单核细胞趋化蛋白（MCP）-1表达的影响，并着重探讨核因子（NF）-κB的作用。
通过套环放置诱导血管损伤。采用实时逆转录聚合酶链反应（RT-PCR）测定MCP-1的表达。通过蛋白质免疫印迹法（Western blot）和电泳迁移率变动分析（EMSA）检测NF-κB的表达及其活性。
在小鼠股动脉周围放置聚乙烯套环可增加MCP-1的表达，同时伴有血管平滑肌细胞增殖和损伤动脉内膜增生。损伤动脉胞质组分中NF-κB含量降低，而核组分中NF-κB含量增加。在核组分中，NF-κB与MCP-1启动子区域的结合活性显著增加。另一方面，套环放置后损伤动脉胞质组分中IκB含量降低，同时IκB激酶（IKK）磷酸化增加。以5mg/kg/天的剂量用CCB硝苯地平治疗小鼠，可显著减少血管平滑肌细胞增殖和内膜增生，且不影响血压。该剂量的硝苯地平可抑制损伤动脉中MCP-1表达的增加。此外，硝苯地平可降低损伤动脉中NF-κB的核含量及其DNA结合活性。相反，硝苯地平可减弱胞质组分中IκB含量的降低和IKK磷酸化的增加。
这些结果表明，炎症性血管损伤中MCP-1的表达受NF-κB激活的调节。结果还提示，硝苯地平通过抑制NF-κB的核转位及其DNA结合活性，减轻损伤动脉中MCP-1的表达，从而改善血管重塑。
