人骨髓间充质干细胞的衰老机制及其“永生化”技术

背景：人类骨髓间充质干细胞由于其自身特性,被认为是最有潜力修复坏死心肌的干细胞,并已成为心肌组织工程研究的热点。目的：回顾分析人类骨髓间充质干细胞的衰老机制及根据这些机制建立的人类骨髓间充质干细胞永生化方法。方法：由第一作者检索1990/2010 PubMed数据库、万方数据库及Springer、Science Direct数据库有关骨髓间充质干细胞衰老机制及其永生化方法等方面的文献。结果与结论：骨髓间充质干细胞在体外培养传代过程中存在着细胞老化、干细胞样特征丢失的现象,阻碍了其在临床的广泛应用。通过对p53-p21及p16-pRb等信号通路细胞衰老分子机制的深入了解,研究者们试图建立永生化的骨髓间充质干细胞,包括将HPV16 E6E7蛋白的基因转入人骨髓间充质干细胞建立的KP细胞系,或将端粒末端转移酶反转录酶的片段phTERT-IRES2-EGFP转染入KP细胞,建立3A6细胞系等方法,均在一定程度上延长了骨髓间充质干细胞寿命。但由于利用病毒载体进行基因转染方法带来的基因重组和插入突变等风险及细胞的固有抗病毒反应导致转染成功率较低,因而大量研究集中在了寻找非基因干涉方法上,建立标准化的永生化骨髓间充质干细胞的方法有待进一步研究。

Senescence mechanism and immortalization of human bone marrow mesenchymal stem cells

BACKGROUND：Human bone marrow mesenchymal stem cells（hBMSCs） due to its property are considered one of the most promising stem cell for regeneration of the injured myocardiocytes,and have become the hot point for the study of myocardial tissue engineering.OBJECTIVE：To retrospectively analyze senescence mechanism of hBMSCs and to establish immortalized method of hBMSCs according to these mechanisms.METHODS：The first author retrieved PubMed Database,Wanfang Database,Springer and Science Direct Database for articles on senescence mechanism of hBMSCs and the immortalized method published from 1990 to 2010.RESULTS AND CONCLUSION：The senescence and loss of the stem cell property of BMSCs were found during the cell cultivation in vitro,which profoundly hinders clinical application of hBMSCs.In light of the mechanism of senescence including p53-p21 and p16-pRb,researchers have put intensive effort in finding ways to build up immortalized hBMSCs;methods for immortalization involving KP cells that transfect HPV16 E6E7 gene into BMSCs or 3A6 cells that both HPV16 E6E7 gene and phTERT-IRES2-EGFP are transfected into hBMSCs.Methods above had prolonged the BMSC survival.However,DNA transfection-based methodologies entail some risk of genomic recombination or insertional mutagenesis as well as innate antiviral responses.Thus,the success rate of transfection is low.The search for ways to avoiding senescence without incurring genetic change has become the focus of intense research effort.Standard methods for building up immortalized BMSCs require further study.