【摘要】 目的:研究肿瘤坏死因子(TNF-α)对骨形成蛋白-2(BMP-2)诱导的小鼠成肌C2C12细胞向成骨细胞分化的影响并探讨相关的作用机制。方法:分别以TNF-α(5 ng/mL)和BMP-2(100 ng/mL)单独或联合处理小鼠成肌C2C12细胞,检测细胞中碱性磷酸酶(AKP)的活性;采用BMP-2 100 ng/mL联合不同浓度TNF-α(0、2、5、8、10 ng/mL)或TNF-α5 ng/mL联合不同浓度BMP-2(0、100、200、300 ng/mL)处理细胞,检测细胞中AKP的活性。蛋白质印迹法(Western Blot)检测细胞中Smad1和NF-κB磷酸化的水平。结果:与对照组相比,BMP-2(100 ng/mL)能显著增加C2C12细胞中AKP活性(P<0.05),但TNF-α(5 ng/mL)可显著抑制C2C12细胞中AKP活性(P<0.05)。C2C12细胞中AKP活性随着TNF-α浓度的增加显著降低(P<0.05),但随着BMP-2浓度的增加而显著升高(P<0.05)。与对照组相比,TNF-α能显著降低C2C12细胞中磷酸化Smad1的水平,且显著升高炎症相关因子NF-κB磷酸化水平,但加入BMP-2对NF-κB无显著影响。结论:TNF-α能抑制BMP-2诱导的C2C12细胞向成骨细胞分化,且具有一定的剂量效应,其作用机制可能与调控炎症相关因子NF-κB活性干预BMP2-Smad1信号通路有关。更多还原

【Abstract】 Objective: To investigate the effects of tumor necrosis factor-α(TNF-α) on osteoblast differentiation of mouse myoblasts C2C12 induced by bone morphogenetic protein-2(BMP-2) and its possible mechanism. Methods: The myogenic C2C12 cells were treated with TNF-α(5 ng/mL) and BMP-2(100 ng/mL) alone or in combination, and the activity of alkaline phosphatase(AKP)in the cells was detected; BMP-2 was maintained at 100 ng/mL combined with different concentrations of TNF-α(0 ng/mL,2ng/mL, 5 ng/mL,8 ng/m L, 10 ng/mL), or TNF-α to keep 5 ng/mL combined with different concentrations of BMP-2(0 ng/mL, 100 ng/mL, 200 ng/mL, 300 ng/mL)were used to treated cells, to analysis of the activity of AKP. The levels of Smad1 and NF-κB phosphorylation in cells were detected by Western Blot. Results: Compared with the control group, BMP-2(100 ng/mL) significantly increased AKP activity(P<0.05) in C2C12 cells, but TNF-α(5 ng/mL) significantly inhibited the activity of AKP in C2C12 cells(P<0.05). The activity of AKP in C2C12 cells decreased significantly with the increase of TNF-α concentration(P<0.05), but increased significantly with the increase of BMP-2 concentration(P<0.05). Compared with the control group, TNF-α were significantly reduced the level of phosphorylated Smad1 in C2C12 cells and significantly increased the phosphorylation level of inflammatory related factor NF-κB. However, BMP-2 had no significant effect on NF-κB. Conclusion: TNF-α can inhibit the differentiation of C2C12 cells into osteoblasts induced by BMP-2, and has a certain dose effect. The mechanism may be related to the regulation of the inflammation-related factor NF-κB activity in BMP2-Smad1 signaling pathway.更多还原