Ding Hao, Chen Song, Song Wen-Qi, Gao You-Shui, Guan Jun-Jie, Wang Yang, Sun Yuan, Zhang Chang-Qing
Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
Int J Biol Sci. 2014 Jun 27;10(7):746-56. doi: 10.7150/ijbs.8535. eCollection 2014.
One of the big challenges in tissue engineering for treating large bone defects is to promote the angiogenesis of the tissue-engineered bone. Hypoxia inducible factor-1α (HIF-1α) plays an important role in angiogenesis-osteogenesis coupling during bone regeneration, and can activate a broad array of angiogenic factors. Dimethyloxaloylglycine (DMOG) can activate HIF-1α expression in cells at normal oxygen tension. In this study, we explored the effect of DMOG on the angiogenic activity of bone mesenchymal stem cells (BMSCs) in the tissue-engineered bone. The effect of different concentrations of DMOG on HIF-1a expression in BMSCs was detected with western blotting, and the mRNA expression and secretion of related angiogenic factors in DMOG-treated BMSCs were respectively analyzed using qRT-PCR and enzyme linked immunosorbent assay. The tissue-engineered bone constructed with β-tricalcium phosphate (β-TCP) and DMOG-treated BMSCs were implanted into the critical-sized calvarial defects to test the effectiveness of DMOG in improving the angiogenic activity of BMSCs in the tissue-engineered bone. The results showed DMOG significantly enhanced the mRNA expression and secretion of related angiogenic factors in BMSCs by activating the expression of HIF-1α. More newly formed blood vessels were observed in the group treated with β-TCP and DMOG-treated BMSCs than in other groups. And there were also more bone regeneration in the group treated with β-TCP and DMOG-treated BMSCs. Therefore, we believed DMOG could enhance the angiogenic activity of BMSCs by activating the expression of HIF-1α, thereby improve the angiogenesis of the tissue-engineered bone and its bone healing capacity.
组织工程学在治疗大的骨缺损方面面临的一大挑战是促进组织工程骨的血管生成。缺氧诱导因子-1α（HIF-1α）在骨再生过程中的血管生成-骨生成偶联中发挥重要作用，并且可以激活多种血管生成因子。二甲基乙二酰甘氨酸（DMOG）能够在正常氧张力下激活细胞中HIF-1α的表达。在本研究中，我们探究了DMOG对组织工程骨中骨间充质干细胞（BMSCs）血管生成活性的影响。采用蛋白质免疫印迹法检测不同浓度DMOG对BMSCs中HIF-1α表达的影响，分别运用实时定量聚合酶链反应（qRT-PCR）和酶联免疫吸附测定法分析经DMOG处理的BMSCs中相关血管生成因子的mRNA表达和分泌情况。将用β-磷酸三钙（β-TCP）和经DMOG处理的BMSCs构建的组织工程骨植入临界大小的颅骨缺损处，以测试DMOG在改善组织工程骨中BMSCs血管生成活性方面的有效性。结果显示，DMOG通过激活HIF-1α的表达显著增强了BMSCs中相关血管生成因子的mRNA表达和分泌。与其他组相比，在β-TCP和经DMOG处理的BMSCs治疗组中观察到更多新形成的血管。并且在β-TCP和经DMOG处理的BMSCs治疗组中也有更多的骨再生。因此，我们认为DMOG可以通过激活HIF-1α的表达来增强BMSCs的血管生成活性，从而改善组织工程骨的血管生成及其骨愈合能力。
