Marolt Darja, Cozin Matthew, Vunjak-Novakovic Gordana, Cremers Serge, Landesberg Regina
Department of Biomedical Engineering, Columbia University, New York, NY 10032, USA.
J Oral Maxillofac Surg. 2012 May;70(5):1081-92. doi: 10.1016/j.joms.2011.05.002.
Administration of bisphosphonates has recently been associated with the development of osteonecrotic lesions of the jaw (ONJ). To elucidate the potential contributions of osteogenic cells to the development and regeneration of ONJ, we have isolated primary cells from human alveolar and long/iliac bones, and examined the effects of pamidronate on cell viability, proliferation, osteogenesis, and wound healing.
Primary human osteoblasts and bone marrow stromal cells were isolated from alveolar and iliac/long bone and marrow tissue. Cellular proliferation, alkaline phosphatase activity, apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling, caspase-3, and 4,6-diamidino-2-phenylindole dihydrochloride assays) and wound healing in an in vitro scratch assay were assessed after exposure to pamidronate at a range of clinically relevant doses.
Primary alveolar osteoblasts proliferated at significantly higher rates than long/iliac bone osteoblasts in vitro. Upon exposure of alveolar osteoblasts and long/iliac bone marrow stromal cells to pamidronate for more than 72 hours, we have observed significantly decreased cell viability, proliferation, osteogenesis, and in vitro wound healing at ≥6 × 10(-5) mol/L pamidronate, with the induction of apoptosis in approximately 20% of cell population.
The remodeling activity of alveolar bone, indicated by higher proliferation of alveolar osteoblasts, could be negatively affected by exposure to high concentrations of pamidronate over extended periods. The absence of anabolic effects of pamidronate on alveolar osteoblasts and the induction of apoptosis in osteogenic cells could negatively affect bone balance at this site and contribute to osteonecrosis of the jaw.
双膦酸盐的使用近来与颌骨骨坏死性病变（ONJ）的发生有关。为了阐明成骨细胞对ONJ发生和再生的潜在作用，我们从人牙槽骨和长骨/髂骨中分离出原代细胞，并研究了帕米膦酸对细胞活力、增殖、成骨及伤口愈合的影响。
从牙槽骨、髂骨/长骨及骨髓组织中分离出人原代成骨细胞和骨髓基质细胞。在体外划痕试验中，用一系列临床相关剂量的帕米膦酸处理细胞后，评估细胞增殖、碱性磷酸酶活性、凋亡（末端脱氧核苷酸转移酶dUTP缺口末端标记法、半胱天冬酶-3及4,6-二脒基-2-苯基吲哚二盐酸盐检测法）及伤口愈合情况。
在体外，原代牙槽骨成骨细胞的增殖速率显著高于长骨/髂骨成骨细胞。当牙槽骨成骨细胞和长骨/髂骨骨髓基质细胞暴露于帕米膦酸超过72小时后，我们观察到，当帕米膦酸浓度≥6×10⁻⁵ mol/L时，细胞活力、增殖、成骨及体外伤口愈合均显著降低，约20%的细胞群体发生凋亡。
牙槽骨成骨细胞较高的增殖速率表明其具有重塑活性，长时间暴露于高浓度的帕米膦酸可能会对其产生负面影响。帕米膦酸对牙槽骨成骨细胞无合成代谢作用，且可诱导成骨细胞凋亡，这可能会对该部位的骨平衡产生负面影响，并导致颌骨骨坏死。
