间充质干细胞的衰老对其免疫调控能力的影响

本研究旨在探讨人脐带间充质干细胞(umbilical cord mesenchymal stem cells,UB-MSC)的衰老对其免疫调控能力的影响。从人脐带中分离MSC并进行传代培养,通过形态学观察其核质比的变化。分别选取第5代(对照组)及第13代(衰老组)MSC进行研究,运用细胞衰老特异性β-半乳糖苷酶检测试剂盒进行衰老检测,并采用CCK-8细胞计数试剂盒检测MSC对淋巴细胞增殖能力的影响,最后通过RT-PCR方法检测免疫调控相关基因在衰老MSC的表达情况。研究结果表明,随传代次数增加,MSC的长宽比增大,核质比减小。细胞衰老检测结果显示,第13代MSC的衰老细胞比例明显增加,但在体外混合淋巴细胞培养体系中,第13代MSC对淋巴细胞增殖的抑制作用与第5代相比明显增强(P<0.05),且第13代细胞免疫抑制相关基因表达增加,促炎相关基因表达减弱。结论:脐带间充质干细胞随体外培养代数增加而逐渐衰老,但免疫抑制能力逐渐加强。

Immunomodulatory Ability of Senile Mesenchymal Stem Cells

This study was aimed to investigate the immunomodulatory ability of human umbilical cord mesenchymal stem cells（UB-MSC） along with prolonging of culture time and increasing of passages in vitro.Mesenchymal stem cells（MSC） were isolated from human umbilical cord and cultured in vitro.The morphological changes and nucleocytoplasmic ratio of MSC were observed using Giemsa staining.MSC of the 5th passage were selected as control group,and MSC of the 13th passage were taken as senile group.The degree of cell senescence was detected by aging cells in situ test kit.Cell Counting Kit-WST-8 was used to determine the proliferation of lymphocytes in mixed lymphocytes coculture system with different passages of MSC.The expression of immunomodulation-related genes was detected by RT-PCR.The results showed that the length-breadth ratio of MSC increased and nucleocytoplasmic ratio decreased along with the increasing of passages.The senium degree of cells of the 13th passage was higher than that of the 5th passage cells.The capacity of suppressing lymphocyte proliferation of the 13th passage MSC was enhanced,compared with the 5th passage.Moreover,the expression of immunosuppression-related genes of senile MSC increased and the expression of most anti-inflammation associated genes declined as compared with young MSC by RT-PCR.It is concluded that the degree of MSC senescence gradually develops with increasing of culture passage,but the immunosupressive ability of MSC strengthens with continuous culture.