微重力对干细胞增殖分化影响的研究进展

Effects of microgravity on proliferation and differentiation of stem cells

微重力环境会影响干细胞的生长、增殖和分化。既往的部分研究表明,微重力环境下培养的间充质干细胞的生长速度较正常重力条件下培养更快,其原因可能是细胞团体积的增大。但是有研究指出微重力能够通过影响细胞周期抑制间充质干细胞增殖。在分化方面,微重力能够抑制间充质干细胞的成骨分化,促进其成脂肪分化,但是对其成软骨分化影响仍存争议。有研究者对微重力培养的间充质干细胞进行基因测序提示其成骨分化相关基因表达降低,同时伴有成脂肪分化的基因表达增高。微重力可能通过整合素/丝裂原活化蛋白激酶和PPAR-γ这两条信号通路抑制干细胞成骨分化作用,而微重力如何影响成软骨分化以及成脂分化的机制仍缺乏相关研究。同时,微重力能够有效地维持间充质干细胞的多能性和自我更新能力。微重力对于间充质干细胞的影响为组织工程的进一步发展提供了探索依据。

Microgravity can effect the proliferation and differentiation of stem cells. Previous studies have shown that the mesenchymal stem cell in microgravity grow faster than that under normal gravity. It may be because of the increase of cell cluster. However, it also indicates that microgravity can inhibit of the proliferation of mesenchymal stem cell by influencing cell cycle. Moreover, microgravity can restrain the osteogenetic differentiation of mesenchymal stem cell,and promote the adipogenic differentiation. However, the study how microgravity influences the chondrogenic differentiation remains controversial. In the gene sequencing test, it shows the gene expression of osteogenesis has decreased,and that of adipogenic differentiation increases. It was possible that microgravity activate intergrin/protein kinase and PPAR-to inhibit osteogenetic differentiation. The mechanism of adipogenic differentiation and chondrogenic differentiation, nevertheless, still lack relevant research. Microgravity can effectively maintain the pluripotency and self-renewal capability of mesenchymal stem cell. The effect of microgravity on mesenchymal stem cells could provide a basis for further development of tissue engineering.