| Summary: | 碩士 === 國立臺灣大學 === 生化科技學系 === 105 === Mesenchymal stem cells (MSCs) are multipotent stem cells which have regenerative and immunoregulatory properties. These features make MSCs being applied in cellular therapy an attractive approach. MSCs can differentiate into osteocytes, chondrocytes and adipocytes under certain culture condition. Recent studies have demonstrated that MSC might lose immunoregulatory properties during the adipogenic differentiation, suggesting its relationships with immunity. Vitamin A and D have been known to regulate the differentiation of MSCs, and might have effects on the immunoregulatory properties of MSCs. Hence, the aim of this study is to investigate the effects of vitamins on differentiation and immunoregulatory properties of MSCs. First, MSCs were isolated from 4-week-old BALB/c bone marrow, characterized by specific surface markers, differentiation tendency to adipocytes, chondrocytes and osteocytes under appropriate condition, and the immunoregulatory properties to supress T cells proliferation. After confirming all the above properties of MSCs, MSCs were cultrured in medium containing different concentrations of all trans-retinoic acid, 1α,25-(OH)2D3 and folic acid. Differentiation and immunoregulatory properties were determined on days 3, 7 and 14. These results showed that after a 7-day culture, vitamin A reduced the gene exprsesion of PPARγ, C/EBPα, Ap2, Glut4, and promoted the proliferation of MSCs. Vitamin D under 0.1 nM reduced the gene exprsesion of C/EBPα, Ap2, but also inhibited the proliferation of MSCs. Folic acid promoted the proliferation of MSCs and under 100 μM could reduce the expression of C/EBPα. On the other hand, all of these vitamins did not alter the inhibitory effect of MSC subsets on CD4+ T cell proliferation. Vitamin A and folic acid reduced the gene expression of Tnfα, Tgfb after a 7-day culture. Besides, Vitamin A enhanced the expression of Il-6 after a 14-day culture. In conclusion, Vitamin A could promote the proliferation of MSCs and inhibited the adipogenesis of MSCs. Vitamin D could inhibit the expression of adipocyte-related gene, but also inhibit the proliferation of MSCs. Folic acid could also promote the proliferation of MSCs, and maintain MSCs in an undifferentiated state. This research suggested that addition of vitamins at certain concentration might alter MSC proliferation and differentiation, which provides information for the expansion of MSCs.
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