骨水泥颗粒促进成纤维母细胞介导的骨溶解

Bone cement particles promote fibroblast-supported osteolysis

目的检验松动假体周围假膜组织中成纤维母细胞是否能够分泌细胞核因子B受体活化因子配体(RANKL)并支持破骨细胞分化,并研究骨水泥颗粒对上述过程的影响。方法酶消化法从人工假体周围假膜标本中分离成纤维母细胞并作体外培养、传代后,一部分成纤维母细胞与外周血单核细胞共培养,并分别加入骨水泥颗粒及与免疫球蛋白Fc段融合的重组可溶性RANK胞外结构域(RANK:Fc)或抗TNF-抗体(anti-TNF-);培养结束后检测破骨细胞的形成,并比较各组细胞的骨吸收活性。另一部分成纤维母细胞单独培养并向实验组加入骨水泥颗粒,半定量RT-PCR法检测RANKL和骨保护素(OPG)mRNA的表达。结果细胞共培养结束时观察到具有生物学活性的破骨细胞形成;RNAK:Fc完全阻断后者的形成,而anti-TNF-则无明显抑制作用;骨水泥颗粒组破骨细胞活性较对照组增加(<0.001)。成纤维母细胞表达RANKL和OPGmRNA,骨水泥颗粒组的表达量较对照组分别增加1.6倍和1.4倍(值分别为0.005和0.008),并且RANKL/OPG的比率增大(=0.01)。结论人工假体周围假膜中成纤维母细胞表达RANKL并支持破骨细胞分化及其骨吸收活性;骨水泥颗粒显著提高这种基质细胞表达RANKL/OPG的比率,从而促进成纤维母细胞支持的溶骨。

Objective To observe whether fibroblasts from failure prosthetic pseudomembrane can express RANKL and support osteoclast formation, and to investigate the effect of bone cement particles on this process. Methods Fibroblasts were isolated from the inner granulation tissue of fresh pseudomembrane from 7 patients undergoing revision arthroplasty for aseptic loosening of the hip. Part of these fibroblasts was co-cultured with peripheral blood monocytes. RANKL an- tagonist RANK：Fc, TNF-a neutralizing antibody anti-TNF-a and bone cement particles were added to the co-cultures re- spectively. At the end of the culture, the formation of osteoclast was analyzed. Another part of the fibroblasts were cultured in the presence and absence of bune cement particles. Semiquantitive RT-PCR was performed to study the effect of bone cement particles on the expression of RANKL and OPG mRNA in the stromal cells. Results Osteoclasts were formed both in the presence and absence of bone cement particles, while osteoclast activity in the particles group was significantly increased（85.57±11.32 vs 51.81±14.02,P〈0.001）. RANK：Fc completely blocked the formation of osteoclast, while anti- TNF-u had no effect on this process. The expression of RANKL and OPG mRNA in particles group was increased 1.6 folds and 1.4folds respectively （P=0.005, 0.008 respectively） compared to the control group, and the ratio of RANKL/OPG was also significantly increased （P=0.01）. Conclusion Fibroblasts from the inner granulation tissue of failure prosthetic pseudomembrane can express RANKL and support osteoclast formation. Bone cement particles promote this process through up-regulation of RANKL/OPG ratio expressed in the fibroblasts.