P-15肽促进间充质干细胞向软骨细胞分化的分子机制及体内成骨作用研究  

Molecular mechanism of P-15 peptide promoting the differentiation of mesenchymal stem cells into chondrocytes and its function of osteogenesis in vivo

作　　者：张郡[1] 杨利丽[1] 刘钦毅[1] 孟宪荣[1] 刘睿[1] 王瑞强[1] 田海清[1] 万腾[1] ZHANG Jun YANG Li-li LIUQin-yi et al(The Second Hospital of Jilin University ,Changchun 130041 ,China)

机构地区：[1]吉林大学第二医院,吉林长春130041

出　　处：《中国实验诊断学》2017年第9期1619-1621,共3页Chinese Journal of Laboratory Diagnosis

摘　　要：目的通过细胞实验研究发现P-15肽能有效激活、促进间充质干细胞增殖和向软骨细胞分化,但是否在体内仍有类似作用尚不明确。因此,本研究旨在探讨P-15肽可能如何激活、促进干细胞向软骨细胞增殖分化,同时在体内功能状态。方法培养鼠间充质干细胞在含有和不含有P-15肽的培养基中,培养6小时后,两组细胞均用α5整合素抗体和pFAK抗体染色,进行免疫荧光染色,同时进行蛋白免疫印迹分析;在维斯塔小白鼠腹部皮下注射250μl含有P-15+rhBMP-2或单纯rhBMP-2的基质胶建立小鼠皮下异位骨化模型,术后12天处死小鼠,分离取下腹部基质胶行Micro CT及组织学检查。结果 (1)与对照组相比,P-15肽培养组pFAK和α5整联蛋白的表达较对照组均有显著性增高(P<0.05);(2)Micro CT扫描、组织切片染色及免疫组织化学均提示P-15肽组基质胶周边软骨沉积,发现肥大软骨细胞沉积在外围区域。结论 (1)P-15肽可能通过激活pFAK通路并上调α5整联蛋白的表达促进MSCs向软骨细胞分化;(2)P-15肽能促进局部组织软骨沉积,进而出现组织骨化。Objective P15 peptide enhances chondrocyte differentiation and formation in vitro. However,the mechanism is unclear, and whether this is effective in vivo is not clear. In this study, we assessed the mechanism of chondrogenic differentiation in vitro. Further investigationto determine whether P15 could independently direct chondrogenesis or mineralization in vivo. Methods To determine if P15 enhances chondrogenic differentiation through integrin α5/pFAK signaling, we stained MSCs that had been maintained on either uncoated or P15-coated dishes using antibodies specific for α5 integrin or pFAK. Six hours after plating,the expression of integrin was determined by Western blot and fluorescent immunohistochemistry. Male Wistar mices received two injections of Matrigel with bone morphogenetic protein2（BMP2） in the right abdominal region and two injections of Matrigel with P15 in the left abdominal region, respectively. 12 days after injections, thetransplanted masses were excised and analyzed by micro CT and histology. Results Compare to the control group, cells grown in vitroon surfaces coated with the P15 peptide have increased α5integrin expression and show activation of FAK（P〈0. 05）. When P15 was combined with BMP2,it was observed that an increased number of MSCs transformed into chondrocytes at D12. Conclusion P15 may interact indirectly with integrin α5/pFAK signaling to enhance chondrocyte differentiation. P15 has the ability to increase bone formation through endochondral formation.

关 键 词：P-15肽 软骨细胞 软骨内骨化 分化 α5整合蛋白/pFAK信号通路 

分 类 号：R68[医药卫生—骨科学]