Kim Tack-Joong, Yun Yeo-Pyo
Research Center for Bioresource and Health, College of Pharmacy, Chungbuk National University, 48 Gaesin-Dong, Heungduk-Gu, Cheongju, Chungbuk, Korea.
Vascul Pharmacol. 2007 Jan;46(1):43-51. doi: 10.1016/j.vph.2006.06.007. Epub 2006 Jun 16.
Platelet derived growth factor (PDGF)-BB is one of the most potent vascular smooth muscle cell (VSMC) proliferative factors, and abnormal VSMC proliferation by PDGF-BB plays an important role in the development and progression of atherosclerosis. The aim of this study was to assess the effect of NQ304 [2-chloro-3-(4-hexylphenyl)-amino-1,4-naphthoquinone], a newly synthesized 1,4-naphthoquinone derivative, on the proliferation of PDGF-BB-stimulated rat aortic VSMCs. Antiproliferative effects of NQ304 on rat aortic VSMCs were examined by direct cell counting and by using [(3)H] thymidine incorporation assays. It was found that NQ304 potently the growth of VSMCs. Preincubation with NQ304 (1-10 microM) significantly inhibited proliferation and DNA synthesis of 50 ng/ml PDGF-BB-stimulated rat aortic VSMCs in a concentration-dependent manner. In addition, we investigated the mechanism of proliferation suppression by NQ304 in PDGF-BB-stimulated rat aortic VSMCs, and found that PDGF-BB-stimulated immediate-early gene expression (c-fos), activator protein (AP)-1 activation, extracellular signal-regulated kinase 1 and 2 (ERK1/2) phosphorylation, and Akt kinase were significantly inhibited by NQ304. An examination of the suppressive effects of NQ304 on PDGF-BB-stimulated VSMC cycle progression showed that NQ304 (10 microM) induced the G1 phase arrest of PDGF-BB-stimulated cell cycle progression by elevating p21(cip1) mRNA expression. These findings suggest that the inhibitory effects of NQ304 on DNA synthesis, proliferation, and cell cycle progression on PDGF-BB-stimulated VSMCs are mediated via the downregulations of AP-1 activation and c-fos expression achieved in turn via the suppressions of the phosphatidylinositol 3-kinase (PI3K)/Akt and ERK1/2 signaling pathways.
血小板衍生生长因子（PDGF）-BB是最有效的血管平滑肌细胞（VSMC）增殖因子之一，PDGF-BB引起的VSMC异常增殖在动脉粥样硬化的发生和发展中起重要作用。本研究旨在评估新合成的1,4-萘醌衍生物NQ304 [2-氯-3-（4-己基苯基）-氨基-1,4-萘醌]对PDGF-BB刺激的大鼠主动脉VSMC增殖的影响。通过直接细胞计数和使用[³H]胸苷掺入试验检测NQ304对大鼠主动脉VSMC的抗增殖作用。发现NQ304有效抑制VSMC的生长。用NQ304（1-10 microM）预孵育以浓度依赖的方式显著抑制50 ng/ml PDGF-BB刺激的大鼠主动脉VSMC的增殖和DNA合成。此外，我们研究了NQ304在PDGF-BB刺激的大鼠主动脉VSMC中抑制增殖的机制，发现NQ304显著抑制PDGF-BB刺激的即刻早期基因表达（c-fos）、激活蛋白（AP）-1激活、细胞外信号调节激酶1和2（ERK1/2）磷酸化以及Akt激酶。对NQ304对PDGF-BB刺激的VSMC细胞周期进程的抑制作用的检查表明，NQ304（10 microM）通过提高p21（cip1）mRNA表达诱导PDGF-BB刺激的细胞周期进程的G1期阻滞。这些发现表明，NQ304对PDGF-BB刺激的VSMC的DNA合成、增殖和细胞周期进程的抑制作用是通过依次抑制磷脂酰肌醇3激酶（PI3K）/Akt和ERK1/2信号通路实现的AP-1激活和c-fos表达的下调介导的。
