Gao Liu, Li Shilun, Li Yukun
Department of Endocrinology, The Third Hospital of Hebei Medical University139 Ziqiang Road, Shijiazhuang 050051, Hebei Province, China.
Key Orthopaedic Biomechanics Laboratory of Hebei Province139 Ziqiang Road, Shijiazhuang 050051, Hebei Province, China.
Am J Transl Res. 2018 Jan 15;10(1):315-324. eCollection 2018.
This study aimed to investigate the effect and mechanisms of Exendin-4 mediated-Hedgehog/Gli1 signaling pathway on the differentiation of osteoblasts in mouse. The alkaline phosphate activity, alizarin red staining and expression of Gli1, GLP-1R, Hedgehog, Runx2 and osteocalcin were analyzed using PCR and Western blot analysis after treating the osteoblastic cell line MC3T3-E1 with Exendin-4. Osteoblasts were treated with Gli1-siRNA and Hedgehog receptor antagonist Cyclopamine (Cy) and analyzed for their impact on the Hedgehog/Gli1 signaling pathway. Our results showed that optimal treatment of Exendin-4 was 7 days at 10 mol/L. Exendin-4 significantly promoted osteoblast formation in the cell line in a dose-dependent manner and up-regulated the expression of GLP-1R, Hedgehog and Gli1. Gli1-siRNA significantly down regulated the expression of Gli1 and Runx2, and offset Exendin-4-induced osteoblast differentiation. Similarly, Cy offset Exendin-4-induced Gli1 up-regulation. It is clear that Exendin-4 can promote the osteogenic differentiation of osteoblasts through Hedgehog/Gli1 signaling pathway.
本研究旨在探讨艾塞那肽-4介导的刺猬因子/胶质瘤相关癌基因同源物1（Hedgehog/Gli1）信号通路对小鼠成骨细胞分化的影响及其机制。在用艾塞那肽-4处理成骨细胞系MC3T3-E1后，采用聚合酶链反应（PCR）和蛋白质免疫印迹法分析碱性磷酸酶活性、茜素红染色以及Gli1、胰高血糖素样肽-1受体（GLP-1R）、刺猬因子、核心结合因子α1（Runx2）和骨钙素的表达。用Gli1小干扰RNA（siRNA）和刺猬因子受体拮抗剂环杷明（Cy）处理成骨细胞，并分析其对Hedgehog/Gli1信号通路的影响。我们的结果显示，艾塞那肽-4的最佳处理浓度为10 μmol/L，处理时间为7天。艾塞那肽-4以剂量依赖的方式显著促进细胞系中成骨细胞的形成，并上调GLP-1R、刺猬因子和Gli1的表达。Gli1-siRNA显著下调Gli1和Runx2的表达，并抵消艾塞那肽-4诱导的成骨细胞分化。同样，Cy抵消了艾塞那肽-4诱导的Gli1上调。显然，艾塞那肽-4可通过Hedgehog/GliI信号通路促进成骨细胞的成骨分化。
