OPG对TNF诱导的成骨细胞凋亡的抑制作用

Inhibitory effect of osteoprotegerin(OPG) on TNF-α induced apoptosis of osteoblastic cells

目的 探讨TNF α能否诱导成骨类细胞凋亡及OPG能否抑制其凋亡 ,开辟一条防治骨质疏松的新路。方法 将人间充质干细胞在分化培养液中培养 2 1天使之成为成骨细胞 ,与MG6 3一起用于凋亡实验。鼠WEHI 16 4细胞系用于阳性对照。AnnexinV和TUNEL分析方法检测成骨类细胞凋亡。结果 和FasL诱导细胞凋亡一样 ,TNF α能引起MG6 3骨肉瘤细胞、间充质干细胞和成骨细胞的凋亡 ,并表现为明显的浓度依赖和时间依赖。低浓度TNF α(170～ 5 0 0 pmol/L)作用于细胞 2～ 4h就显示了较明显的凋亡 ,而 0 4 5～1 5nmol/LOPG几乎完全抑制了 5 0 0 pmol/LTNF α诱导的凋亡。结论 OPG能够抑制TNF α诱导的成骨类细胞凋亡。

Objective To investigate induction of apoptosis of osteablastic cells induced by TNF-α and the inhibitory effect of OPG on this pathological process. Methods MG63 osteosarcoma cells and cultured osteoblasts isolated from human mesenchymal stem cells were chosen as the experimental cells for assessment of apoptosis induced by TNF-α, while murine WEHI 164 sarcoma cells were employed as positive control. Annexin V and terminal deaxyoridine nick-end labeling stain (TUNEL) were used as indicators for apoptosis. Results Apoptosis of osteoblasts occurred 2-4 hours after the treatment of 170-500pmol/L TNF-α. OPG at the cncerntration of 0.45-1.5nmol/L almost completely inhibited the apoptosis mediated by 500pmol/L TNF-α. WEHI cells showed increased sensitivity to TNF-α; TNF-α-mediated apoptosis was prevented by excess OPG when it was pre-incubated with TNF-α at 37℃. Osteoblasts produced OPG while osteoclastic cells produced TNF-α, both at concentrations consistent with their functional effects in bone. Conclusion OPG can inhibit the apoptosis induced by TNF-α in MG63 osteosarcoma cells, osteoblasts and human mesenchymal stem cells.