Sun Mingqi, Yang Junli, Wang Jianzhong, Hao Ting, Jiang Dianming, Bao Guoyu, Liu Guanghui
Department of Orthopaedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
Medical Examination Center, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot 010010, China.
Cytokine. 2016 Apr;80:35-42. doi: 10.1016/j.cyto.2016.01.011. Epub 2016 Mar 3.
Fracture healing is regulated by proinflammatory mediators such as tumor necrosis factor-α (TNF-α), which poses influence on the balance between bone formation and remodeling. And the diabetes is thought to contribute to the delayed diabetic fracture healing. In the present study, we examined the promotion to proinflammatory cytokines and chemokines in type 2 diabetes mellitus (T2DM) patients with bone fractures, and then evaluated the promotion to TNF-α by the high glucose treatment in human osteoblast-like MG-63 cells and the regulatory role of the promoted TNF-α on the MG-63 cell apoptosis. It was demonstrated that there were significantly-upregulated high-sensitivity C-reactive protein (hsCRP) TNF-α, IL-1β, IL-6, IFN-γ-inducible protein 10 (IP-10) and RANTES in T2DM patients with bone fracture. And the promotion to TNF-α and IL-1β was confirmed in vitro in both mRNA and protein levels in high glucose-treated MG-63 cells. And either TNF-α or high glucose reduced the viability of MG-63 cells, promoted apoptosis and upregulated apoptosis-associated markers, such as released cytochrome c, cleaved caspase 3 and lyzed PARP. Moreover, there was a synergistic effect between TNF-α and high glucose. The viability reduction and the apoptosis induction of MG-63 cells were significantly higher in the group with both TNF-α and high glucose treatments, than in the group with singular TNF-α treatment. In conclusion, our study demonstrated that proinflammatory cytokines and chemokines were promoted in T2DM patients with bone fracture or in osteoblasts by the high glucose stimulation. TNF-α and high glucose synergistically reduced the viability and induced the apoptosis in the osteoblast-like MG-63 cells in vitro. It implies the significant regulatory role of TNF-α in the delayed fracture healing in T2DM.
骨折愈合受肿瘤坏死因子-α（TNF-α）等促炎介质调节，其对骨形成与重塑之间的平衡产生影响。糖尿病被认为会导致糖尿病性骨折愈合延迟。在本研究中，我们检测了2型糖尿病（T2DM）骨折患者促炎细胞因子和趋化因子的升高情况，然后评估高糖处理对人成骨样MG-63细胞中TNF-α的促进作用以及所促进的TNF-α对MG-63细胞凋亡的调节作用。结果表明，T2DM骨折患者的高敏C反应蛋白（hsCRP）、TNF-α、白细胞介素-1β（IL-1β）、白细胞介素-6（IL-6）、γ干扰素诱导蛋白10（IP-10）和调节激活正常T细胞表达和分泌因子（RANTES）显著上调。高糖处理的MG-63细胞在mRNA和蛋白水平上均证实了对TNF-α和IL-1β的促进作用。TNF-α或高糖均可降低MG-63细胞的活力，促进细胞凋亡并上调凋亡相关标志物，如释放的细胞色素c、裂解的半胱天冬酶3和裂解的聚（ADP-核糖）聚合酶（PARP）。此外，TNF-α与高糖之间存在协同作用。TNF-α和高糖联合处理组MG-63细胞活力降低和凋亡诱导显著高于单独TNF-α处理组。总之，我们的研究表明，高糖刺激可促进T2DM骨折患者或成骨细胞中促炎细胞因子和趋化因子的产生。TNF-α与高糖在体外协同降低成骨样MG-63细胞的活力并诱导其凋亡。这意味着TNF-α在T2DM延迟性骨折愈合中具有重要的调节作用。
