肿瘤坏死因子α对小鼠破骨细胞分化的影响

目的:在诱导破骨细胞分化的体外骨髓细胞培养系统中,研究破骨细胞分化因子(RANKL)存在和不存在的情况下,肿瘤坏死因子α(TNF-α)对破骨细胞分化的影响.方法:选用小鼠巨噬细胞集落刺激因子(M-CSF)依赖性非附着性骨髓细胞,在含有25μg/L M-CSF和0,l,10,100μg/L TNF-α的α-MEM培养液中培养5 d后,观察抗酒石酸酸性磷酸酶染色(TRAP)阳性多核细胞的形成;细胞在含有25 μg/L M-CSF和30μg/L sRANKL的α-MEM培养液中进行培养,比较加入和不加人10μg/L TNF-α培养4、5、6和9 d后,所形成的TRAP( )多核细胞的数目和骨吸收面积.结果:TNF-α在没有RANKL的情况下,不能诱导小鼠骨髓细胞形成破骨细胞.在RANKL存在的情况下,TNF-α可促进破骨样细胞的形成和骨吸收,但对破骨细胞分化的促进作用仅表现在培养的早期.结论:在RANKL存在的情况下TNF-α可促进破骨细胞的分化,但不能取代RANKL.TNF-α加速破骨细胞的形成,却并不延长其生存时间.

Effect of TNF-α on murine osteoclast differentiation

OBJECTIVE: The purpose of this study was to investigate the effect of TNF-alpha on osteoclast differentiation in primary murine bone marrow cell culture with and without RANKL. METHODS: M-CSF-dependent bone marrow cells were isolated from 5-6 weeks old mice, and cultured in the presence of M-CSF (25 microg/L) with different concentrations of TNF-alpha (0, 1, 10, 100 microg/L) for 5 days, the formation of TRAP(+) multinucleated cells was observed. These cells were also cultured in the presence of both RANKL (30 microg/L) and M-CSF (25 microg/L) with or without 10 microg/L TNF-alpha for 4, 5, 6 and 9 days. The number of TRAP(+) multinucleated cells and resorption pits on dentine slices were counted under light microscope. RESULTS: In the absence of RANKL, TNF-alpha was unable to induce osteoclast formation from murine bone marrow precursors. In the presence of RANKL, TNF-alpha augmented osteoclastogenesis and bone resorption, and this effect occurred only on the early stage. CONCLUSION: TNF-alpha enhances RANKL-induced osteoclast formation and function, but cannot substitute for RANKL. TNF-alpha stimulates osteoclast differentiation, but not survival.