BMP12基因和间充质干细胞修复兔跟腱缺损的形态学研究

Morphologic Study of Rabbit Achilles′s Tendon Defect Repaired with Bone Morphogenetic Protein 12 Gene and Bone Marrow Mesenchymal Stem Cells

目的 观察用BMP12基因和间充质干细胞修复兔跟腱缺损的形态学变化。方法 模拟微重力条件下构建两种组织工程化肌腱。 2 4只新西兰白兔分为 4组 :①单纯人发角蛋白 (HHK对照组 )组 ;②骨髓间充质干细胞 (MSCs) /HHK组织工程化肌腱组 ;③骨形态发生蛋白 12 (BMP12 )基因诱导的腱细胞 /HHK组织工程化肌腱组 ;④pTARGET BMP12质粒 /HHK组。采用光电镜、免疫组织化学和RT PCR方法观察术后不同时期损伤肌腱的修复情况。结果 MSCs/HHK组织工程化肌腱组和基因诱导的腱细胞 /HHK组织工程化肌腱组的缺损肌腱的再生修复效果均优于单纯HHK组 ,尤以基因诱导的腱细胞 /HHK组织工程化肌腱组的修复效果最佳 ,且伴随有Ⅰ型胶原mRNA表达的增高。结论 BMP12基因和MSCs通过促进内源性愈合参与了缺损肌腱的再生修复。

Objective To observe the morphologic changes of rabbit Achilles′s tendon defect repaired with bone morphogenetic protein 12 gene and human marrow mesenchymal stem cells. Methods In this experiment, two kinds of tissue-engineered tendons were constructed duder simulated microgravity in the rotary cell culture system, one is made of mesenchymal stem cells (MSCs) and human hair keratin (HHK) (named MSCs/HHK tendon), the other is made of tenocytes induced by bone morphogenetic protein 12 gene (BMP12) and HHK (named induced tenocytes/HHK tendon). The Achilles′s tendon defects of 24 New Zealand white rabbits were established and divided into 4 groups: ① HHK group (as control group), ② MSCs/HHK group, ③gene-induced tenocytes/HHK group and ④ pT ARGE T-BMP12 plasmid mediated by liposome/HHK tendon group. Using light and electromicroscope, immunohistochemistry and RT-PCR methods to observe the structures of the repaired tendons of each groups in different stages were observed. Results The degree of tendon regeneration in the implanted tissue-engineered tendon group and the pT ARGE T-BMP12 plasmid mediated by liposome/HHK tendon group were much better than that in HHK tendon group, associated with the increased expression of collagen Ⅰ, especially the gene-induced tenocytes/HHK tendon. Conclusion BMP12 gene and MSCs plays an important role in tendon regeneration by improving intrinsic healing and avoiding adhesion.