Goater J Jeffrey, O'Keefe Regis J, Rosier Randy N, Puzas J Edward, Schwarz Edward M
Department of Orthopaedics, The Center for Musculoskeletal Research, University of Rochester Medical Center, NY 14642, USA.
J Orthop Res. 2002 Mar;20(2):169-73. doi: 10.1016/S0736-0266(01)00083-3.
Aseptic loosening of prosthetic implants remains a serious orthopaedic problem and the greatest limitation to total joint arthroplasty. Central to the etiology of aseptic loosening is periprosthetic osteolysis at the bone-implant interface, which is caused by wear debris-induced inflammation. This inflammation produces the critical osteoclast differentiation factor RANKL, which directly stimulates osteoclastogenesis and osteoclastic bone resorption. A dominant factor known to counteract this process is the natural RANKL receptor antagonist protein OPG. Here we explore the potential of ex vivo OPG gene therapy for aseptic loosening by evaluating the eflicacy of stably transfected fibroblast-like synoviocytes (FLS) expressing OPG in preventing wear debris-induced osteoclastogenesis, in a mouse calvaria model. Although the stably transfected fibroblasts produced small amounts of OPG (0.3 ng/ml/72 h/10(6) cells), this protein was very effective in preventing osteoclastic resorption as determined in a bone wafer assay. More importantly. implantation of 10(7) FLS-OPG, together with 30 mg of Ti wear debris, onto the calvaria of mice, completely inhibited osteoclastogenesis 3 days after surgery. Animals given FLS-LacZ control cells, which persisted for 3 days as determined by X-gal staining, together with the Ti particles, had a 6-fold increase in osteoclastogenesis compared to controls without Ti. This increased osteoclastogenesis was completely inhibited by the FLS-OPG, as osteoclast numbers in the calvaria of these animals were similar to that seen in the SHAM controls.
假体植入物的无菌性松动仍然是一个严重的骨科问题，也是全关节置换术的最大限制因素。无菌性松动病因的核心是骨-植入物界面处的假体周围骨溶解，这是由磨损颗粒诱导的炎症引起的。这种炎症产生关键的破骨细胞分化因子RANKL，它直接刺激破骨细胞生成和破骨细胞性骨吸收。已知对抗这一过程的一个主要因素是天然的RANKL受体拮抗剂蛋白OPG。在这里，我们通过在小鼠颅骨模型中评估稳定转染表达OPG的成纤维细胞样滑膜细胞（FLS）在预防磨损颗粒诱导的破骨细胞生成方面的效果，探讨离体OPG基因治疗无菌性松动的潜力。尽管稳定转染的成纤维细胞产生少量的OPG（0.3 ng/ml/72 h/10⁶个细胞），但在骨片分析中确定，这种蛋白在预防破骨细胞性吸收方面非常有效。更重要的是，将10⁷个FLS-OPG与30 mg钛磨损颗粒一起植入小鼠颅骨，在手术后3天完全抑制了破骨细胞生成。给予FLS-LacZ对照细胞（通过X-gal染色确定其持续存在3天）与钛颗粒的动物，与没有钛颗粒的对照组相比，破骨细胞生成增加了6倍。这种增加的破骨细胞生成被FLS-OPG完全抑制，因为这些动物颅骨中的破骨细胞数量与假手术对照组相似。
