promotes proliferation and migration of human microvascular endothelial cells

目的：骨保护素（OPG）是破骨细胞发生的关键调节因子。我们最近报道了内皮细胞对牙龈卟啉单胞菌的反应产生高水平的OPG。我们还发现，OPG处理可以保护人微血管内皮细胞（HMVECs）免受牙龈素活性细菌细胞提取物诱导的脱离和凋亡细胞死亡。这些结果表明，在牙周炎期间，骨保护素可作为内皮细胞的存活因子。然而，OPG在内皮中的作用尚不清楚。在本研究中，我们研究了OPG对HMVECs的影响。方法：在无血清条件下，用或不加OPG（终浓度为1 μ g/ml）培养HMVECs 4 d。采用四氮唑（WST-8）还原法评估细胞存活率。通过伤口愈合试验评估细胞迁移。采用整合素介导的细胞粘附试剂盒检测整合素在细胞表面的表达，该试剂盒由包被抗αvβ3抗体的板组成。结果：剥夺血清4 d内，经opg处理的HMVECs存活率为36.7%，未经opg处理的HMVECs存活率仅为20.0% （P < 0.05）。伤口愈合实验显示，与未处理的细胞相比，opg处理的hmvec在22小时内迁移到大约四分之三的受伤区域，而opg处理的细胞几乎没有迁移。此外，在血清剥夺条件下，OPG处理24 h可显著增加HMVECs表面αvβ3整合素的表达（P < 0.05）。结论：OPG可保护HMVECs免受血清剥夺诱导的细胞死亡。此外，OPG处理HMVECs可促进细胞迁移，上调vn3的表达。αvβ3介导内皮细胞存活通路。因此，我们的研究结果也表明，OPG可能通过影响α v β 3的表达来调节内皮细胞的存活。

Objective: Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis. We recently reported that endothelial cells produce high levels of OPG in response to Porphyromonas gingivalis. We also indicated that OPG treatment protects human microvascular endothelial cells (HMVECs) from detachment and apoptotic cell death induced by gingipain-active bacterial cell extracts. These results suggest that osteoprotegerin acts as a survival factor for endothelial cells during periodontitis. However, the role of OPG in the endothelium remains unknown. In this study, we investigated the effects of OPG on HMVECs. Methods: HMVECs were incubated with or without OPG (1 u g/ml final concentration)under a serum-free condition for 4 days. Cell survival was assessed by a tetrazolium (WST-8) reduction assay. Cell migration was assessed by a wound-healing assay. The expression of integrin on the cell surface was determined using the integrin-mediated cell adhesion kit, which consists of plates coated with an anti-αvβ3 antibody. Results: Within 4 days of serum deprivation, 36.7% of OPG-treated HMVECs were viable, whereas only 20.0% of OPG-untreated HMVECs were viable (P < 0.05). Wound-healing assay revealed that within 22 h, the OPG-treated HMVECs migrated to fill approximately three-quarters of the wounded area when compared with the OPG-untreated cells that showed very little migration. Furthermore, the OPG treatment for 24 h under serum deprivation condition resulted in a significant increase in the surface expression of αvβ3 integrin on the HMVECs (P < 0.05). Conclusions: OPG protects HMVECs against serum-deprivation-induced cell death. Furthermore, OPG treatment of HMVECs promotes cell migration, and up-regulates a v N 3 expression. The αvβ3 mediates the endothelial cell survival pathway. Therefore, our results also suggest that OPG may regulate the endothelial cell survival by affecting the expression of α v β 3.