Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
Int Immunopharmacol. 2012 Jun;13(2):156-62. doi: 10.1016/j.intimp.2012.03.026. Epub 2012 Apr 11.
Hepatocyte growth factor (HGF) has been demonstrated to stimulate osteoblast proliferation and participated bone remodeling. Bone morphogenetic protein-2 (BMP-2) is a crucial mediator in bone formation during fracture healing. However, the effects of HGF in BMP-2 expression in human osteoblasts are large unknown. Here we found that HGF induced BMP-2 expression in human osteoblasts dose-dependently. HGF-mediated BMP-2 production was attenuated by c-Met inhibitor or siRNA. Pretreatment with FAK inhibitor or JNK inhibitor (SP600125) also blocked the potentiating action of HGF. Stimulation of osteoblasts with HGF enhanced FAK phosphorylation, JNK phosphorylation, and RunX2 translocation from cytosol to the nucleus. HGF-mediated Runx2 binding to BMP-2 promoter was inhibited by c-Met inhibitor, FAK inhibitor, and SP600125. The binding of Runx2 to the BMP-2 promoter, as well as the recruitment of p300 and the enhancement of histones H3 and H4 acetylation on the BMP-2 promoter was enhanced by HGF. Our results suggest that HGF increased BMP-2 production in human osteoblasts via the c-Met receptor/FAK/JNK/Runx2 and p300 signaling pathways.
肝细胞生长因子 (HGF) 已被证明可刺激成骨细胞增殖,并参与骨重塑。骨形态发生蛋白 2 (BMP-2) 是骨折愈合过程中骨形成的关键介质。然而,HGF 对人成骨细胞中 BMP-2 表达的影响尚不清楚。在这里,我们发现 HGF 可剂量依赖性地诱导人成骨细胞中 BMP-2 的表达。HGF 介导的 BMP-2 产生可被 c-Met 抑制剂或 siRNA 减弱。FAK 抑制剂或 JNK 抑制剂 (SP600125) 的预处理也阻断了 HGF 的增强作用。HGF 刺激成骨细胞可增强 FAK 磷酸化、JNK 磷酸化以及 Runx2 从细胞质向核内易位。HGF 介导的 Runx2 与 BMP-2 启动子的结合可被 c-Met 抑制剂、FAK 抑制剂和 SP600125 抑制。HGF 增强了 Runx2 与 BMP-2 启动子的结合,以及 p300 的募集和 BMP-2 启动子上组蛋白 H3 和 H4 的乙酰化增强。我们的结果表明,HGF 通过 c-Met 受体/FAK/JNK/Runx2 和 p300 信号通路增加人成骨细胞中 BMP-2 的产生。