MicroRNA-214调节成骨、破骨过程防止早期股骨头骨坏死塌陷

Osteonecrosis of the femoral head (ONFH), which is a type of progressive and refractory disease, which caused by a lack of appropriate blood supply to trabecular bone in the femoral head and bone cell death due to various reasons. How to recover the vitality of femoral head is very important for preventing the collapse of the femoral head. We found that the blood supply of the femoral head with early stage of ONFH increases in the necrotic and sclerosis regions. Osteoclastic Repair is the key factor to result in the collapse of the femoral head.So promote osteogenic activity, inhibit osteoclast activity will be a core factor in the treatment of the ONFH. We found that the expression of the microRNA-214 is high in the samples of the ONFH and the inhibitors of the microRNA-214 can promote osteogenic activity, inhibit osteoclast activity. So we propose innovative view that the inhibitors of the microRNA-214 derived particles used in the treatment of ONFH. Continued to decrease microRNA-214 expression level to promote osteogenic activity, inhibit osteoclast activity and prevent the collapse of the femoral head.

股骨头骨坏死（Osteonecrosis of the Femoral Head, ONFH）是骨科临床上一种常见的难治性疾病，是由于不同原因导致部分股骨头的血供障碍而引起的一系列的病理过程。如何防止早期骨坏死塌陷并恢复股骨头的活力成为关键因素。前期研究结果发现：①早期股骨头骨坏死血供呈区域性分布特征，在硬化区和骨质结构破坏区股骨头血供显著增加；②建立两种鸸鹋股骨头骨坏死模型，提示破骨性骨修复（Osteoclastic Repair）是导致股骨头塌陷的主要因素，促进成骨过程，抑制破骨过程有望防止早期股骨头骨坏死塌陷；③microRNA-214抑制剂可以促进成骨活性，抑制破骨活性；④microRNA-214在早期股骨头骨坏死标本中表达显著升高。课题组尝试制备microRNA-214抑制剂缓释微球，局部调节股骨头坏死区内成骨、破骨过程，防治早期股骨头骨坏死塌陷，保留髋关节功能。

股骨头骨坏死是由多种因素导致的局部骨代谢性疾病，治疗难点在于如何防止早期骨坏死塌陷。目前认为骨坏死区内区域性的骨强度减低是导致塌陷的主要原因。本项目拟在研究人股骨头骨坏死标本骨结构的基础上，探索坏死股骨头内 miRNA-214 表达与局部成、破骨细胞活性之间的关系及潜在机制，制备腺相关病毒搭载 miRNA-214 抑制剂，观察药物调节成骨、破骨活性防治大鼠股骨头骨坏死塌陷的效果。首先根据骨质密度的不同，将临床中收集的股骨头骨坏死样本分为不同区域，分别采用病理学检测、实时荧光定量PCR、Western Blot等方法对骨微观结构及成骨、破骨细胞活性及miRNA-214表达情况进行分析，结果表明坏死区域miRNA-214表达显著增高，破骨活性显著增高，成骨活性显著降低。而硬化区成骨活性显著增高，破骨活性显著降低。同时，miRNA-214在股骨头骨坏死标本坏死区域显著增高。另外，成功制备AAV-anti-miRNA-214，发现其能够明显抑制破骨细胞的功能，促进成骨细胞的功能，同时可以显著下调miRNA-214的表达，TRAP染色结果显示AAV-anti-miRNA-214可以显著抑制骨髓间充质干细胞向破骨细胞分化的能力。MC3T3-E1细胞加入AAV病毒包裹的anti-miRNA-214，发现AAV-anti-miRNA-214能够明显促进成骨细胞的功能，ALP染色的结果显示成骨细胞的功能增强；在大鼠股骨头骨坏死模型治疗中，AAV- anti-miR-214可以促进成骨活性，抑制破骨活性，其双向调节作用可有效防治大鼠早期股骨头骨坏死塌陷，该结果对临床治疗早期股骨头骨坏死具有重要的指导意义。