【摘要】 本文旨在观察血管紧张素II (angiotensin II, Ang II)对血管平滑肌细胞核转录因子-κB (nuclear factor-κB, NF-κB)的活性及骨形成蛋白-2 (bone morphogenetic protein-2, BMP-2)表达的影响,以探讨Ang II参与动脉粥样硬化的机制,并探讨川芎嗪是否能抑制Ang II的促动脉粥样硬化作用。采用Western blot、免疫组化和原位杂交等方法分别检测Ang II刺激和川芎嗪干预后NF-κB活性、BMP-2 蛋白和 mRNA 表达的变化。结果显示:(1) Ang II 刺激激活 NF-κB。Ang II 刺激 15 min 即有 NF-κB p65核转移,30 min 达高峰(P<0.01),1 h 后减退。川芎嗪抑制 Ang II诱导的NF-κB激活,与Ang II组比较,川芎嗪 + Ang II组NF-κB活性显著降低 (P<0.01)。 (2) Ang II 刺激 6 h 时 BMP-2 表达增强(P<0.05),12 h 时减弱(P<0.01),24 h 时更弱(P<0.01)。川芎嗪 + Ang II组中,川芎嗪干预6 h 时BMP-2 表达亦增强,12 与24 h 时保持正常水平。 (3) 川芎嗪对正常细胞的NF-κB活性和BMP-2 表达无影响。以上结果表明,Ang II刺激后激活NF-κB并最终使生长抑制因子BMP-2 表达下降,这可能是其参与动脉粥样硬化发生的机制之一。BMP-2 一过性增高可能不依赖NF-κB通路的激活。川芎嗪可抑制Ang II诱导的NF-κB激活与 BMP-2 表达降低,提示它在抗动脉粥样硬化形成中起重要作用。更多还原

【Abstract】 Tetramethylpyrazine (TMP), an effective component of traditional Chinese medicine Chuanxiong, is commonly used to resolve embolism. Its possible therapeutic effect against atherosclerosis has received considerable attention recently. Angiotensin II (Ang II) is highly implicated in the proliferation of vascular smooth muscle cells (VSMCs), resulting in atherosclerosis. The mecha- nisms of TMP in the proliferation of VSMCs induced by Ang II remain to be defined. The present study was aimed to study the effect of TMP on Ang II-induced VSMC proliferation through detection of nuclear factor-κB (NF-κB) activity and bone morphogenetic protein-2 (BMP-2) expression. Primary cultured rat aortic smooth muscle cells were divided into the control group, Ang II group, Ang II + TMP group and TMP group. Cells in each group were harvested at different time points (15, 30 and 60 min for detection of NF-κB activity; 6, 12 and 24 h for measurement of BMP-2 expression). NF-κB activation was identified as nuclear staining by immunohistochemistry. BMP-2 expression was observed through Western blot, immunohistochemistry and in situ hybridization. The results showed that: (1) Ang II stimulated the activation of NF-κB. Translocation of NF-κB p65 subunit from cytoplasm to nucleus appeared as early as 15 min, peaked at 30 min (P<0.01) and declined after 1 h. (2) TMP inhibited Ang II-induced NF-κB activation (P< 0.01). (3) Ang II increased BMP-2 expression at 6 h but declined it significantly at 12 and 24 h (P<0.01). (4) BMP-2 expression was also kept at high level at 6 h in Ang II + TMP group but maintained at the normal level at 12 and 24 h. (5) There was no significant difference in NF-κB activation and BMP-2 expression between the control group and TMP group. These results indicate that TMP inhibits Ang II-induced VSMC proliferation through repression of NF-κB activation and BMP-2 reduction, and BMP-2 expression is independent of the NF-κB pathway. In conclusion, TMP has therapeutic potential for the treatment of atherosclerosis.更多还原