重组腺相关病毒介导VEGF和BMP双基因共表达对兔早期激素性股骨头坏死的修复作用

Repair effects of co-expression of the VEGF and BMP genes via an adeno-associated viral vector on early steroid-in-duced avascular necrosis of the femoral head in rabbits

目的探讨重组腺相关病毒介导VEGF和BMP双基因共表达对兔早期激素性股骨头坏死的修复作用。方法制备兔早期激素性股骨头坏死模型，经MRI筛选的成模动物随机分为rAAV-IRES-hrGFP（AAV-GFP）、rAAV-hVEGF165-IRES-hrGFP（AAV-VEGF）、rAAV-hBMP-7-IRES．hrGFP（AAV-BMP）及rAAV．hVEGF165-IRES-hBMP-7（AAV-VEGHBMP）四组。通过髓芯减压手术分别将四种重组腺相关病毒载体直接注射人各组髓芯减压区内（25μl／侧）。注射12周后分别应用Westernblot检测、HE及免疫组织化学染色、MR检查、核素骨扫描、股骨头血管墨汁灌注冰冻切片、Micro．CT及股骨头生物力学检测等方法综合评估重组腺相关病毒载体对兔早期激素性股骨头坏死的修复作用。结果兔早期激素性股骨头坏死模型成模率可达73．33％。病毒注射12周后，rAAV．hVEGF165-IRES-hBMP-7载体有效表达hVEGF165，及hBMP-7基因，并产生hVEGF165及hBMP-7目的蛋白；体内表达的hVEGF165目的蛋白通过增加股骨头内新生血管数量改善血供，促进了骨坏死区组织代谢；体内表达的hBMP-7目的蛋白通过增加股骨头区骨矿物质密度，促进髓芯减压后骨生成。AAV-VEGF／BMP组重组腺相关病毒载体较AAV-VEGF组及AAV-BMP组更有效地提高了兔早期激素性股骨头坏死的修复效果。结论hVEGF165和hBMP-7双基因共表达重组腺相关病毒载体通过增加股骨头的血供及增强股骨头骨质量，对兔早期激素性股骨头坏死具有良好的修复作用。

Objective To investigate the repair effects of co-expression of the VEGF and BMP genes via an adeno-as-sociated viral vector on early steroid-induced avascular necrosis of the femoral head in rabbits, nethords To construct ani-mal model of early SANFH and screen by MR1. The SANFH animal were divided into rAAV-IRES-hrGFP （AAV-GFP）, rAAV-hVEGF165-IRES-hrGFP （AAV-VEGF）, rAAV-hBMP-7-IRES-hrGFP （AAV-BMP） and rAAV-hVEGF165-IRES-hBMP-7 （AAV- VEGF/BMP）groups. The four group virus vectors were injected into core decompression region at the dose of 25 μl/site after core decompression operation directly. Repair effects of rAAV vector on early SANFH in rabbits were evaluated by Western blot assay, HE staining, immunohistochemical staining, MRI, radionuclide bone scan, blood vessel counting detected by ink perfusion and fro-zen section, Micro-CT and biomechanical strength detection on the 12th week post-injection. Results Model success ratio was 73.33%. rAAV-hVEGF165-1RES-hBMP-7 virus vector efficiently expressed hVEGF165 and hBMP-7 genes on the 12th week after rAAV injection, hVEGF165 protein secreted in vivo promoted metabolism in core decompression region by increasing the quantity of new vessels and improving the blood supply; hBMP-7 protein secreted in vivo promoted new bone formation in core decompres- sion region by increasing bone mineral density and improving bone biomechanical strength. The AAV-VEGF/BMP group can pro- mote repair effects more effectively than AAV-VEGF group or AAV-BMP group. Conclusion The adeno-associated viral vectors co-expressing hVEGF165 and hBMP-7 can promote repair effects on early SANFH in rabbits by increasing the blood supply and strengthening the bone quality of femoral head.