Effect of simvastatin on inducing endothelial progenitor cells homing and promoting bone defect repair

目的研究局部植入辛伐他汀对兔颅骨极限骨缺损的修复作用及对血管内皮祖细胞(endothelial progenitor cells,EPCs)归巢的影响,探讨辛伐他汀促进骨缺损修复的作用机制。方法将辛伐他汀50mg加聚乳酸200mg以及单纯聚乳酸200mg分别溶解于1mL丙酮,制备辛伐他汀-聚乳酸复合材料及单纯聚乳酸材料。取2只雄性新西兰大白兔骨髓以体外贴壁法培养EPCs,将第3代EPCs制备为2×106个/mL细胞悬液,采用性别错配移植,经耳缘静脉移植至12只雌性新西兰大白兔,每只兔各2mL。移植3d后于12只雌性兔颅骨制备直径15mm的骨缺损,分别将辛伐他汀-聚乳酸复合材料(实验组,n=6)...To investigate the effect of simvastatin on inducing endothelial progenitor cells (EPCs) homing and promoting bone defect repair, and to explore the mechanism of local implanting simvastatin in promoting bone formation.Simvastatin (50 mg) compounded with polylactic acid (PLA, 200 mg) or only PLA (200 mg) was dissolved in acetone (1 mL) to prepare implanted materials (Simvastatin-PLA material, PLA material). EPCs were harvested from bone marrow of 2 male rabbits and cultured with M199; after identified by immunohistochemistry, the cell suspension of EPCs at the 3rd generation (2 x 10(6) cells/mL) was prepared and transplanted into 12 female rabbits through auricular veins (2 mL). After 3 days, the models of cranial defect with 15 cm diameter were made in the 12 female rabbits. And the defects were repaired with Simvastatin-PLA materials (experimental group, n=6) and PLA materials (control group, n=6), respectively. The bone repair was observed after 8 weeks of operation by gross appearance, X-ray film, and histology; gelatin-ink perfusion and HE staining were used to show the new vessels formation in the defect. Fluorescence in situ hybridization (FISH) was performed to show the EPCs homing at the defect site.All experimental animals of 2 groups survived to the end of the experiment. After 8 weeks in experimental group, new bone formation was observed in the bone defect by gross and histology, and an irregular, hyperdense shadow by X-ray film; no similar changes were observed in control group. FISH showed that the male EPC containing Y chromosome was found in the wall of new vessels in the defect of experimental group, while no male EPC containing Y chromosome was found in control group. The percentage of new bone formation in defect area was 91.63% +/- 4.07% in experimental group and 59.45% +/- 5.43% in control group, showing significant difference (P < 0.05).Simvastatin can promote bone defect repair, and its mechanism is probably associated with inducing EPCs homing and enhancing vasculogenesis.PubMed中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)0091103-11062