TGF-β Inhibitor SB431542 Promotes the Differentiation of Induced Pluripotent Stem Cells and Embryonic Stem Cells into Mesenchymal-Like Cells

Figure 4

Average CD29 (a), CD44 (b), CD90 (c), CD9 (d), Tra 1-60 (e), SSEA-3 (f), Oct-4 (g), and HSP90β (h) expression in BM-hMSCs and iPSC/ESC-derived MSCs before and during the mesengenic differentiation process. The results suggest that both CD44 and CD29 lacked expression in undifferentiated cells and cells at MP0. The expression of these markers only increased to levels comparable to those of BM-hMSCs after the first passage into MPC Growth MEM media. By MP2, the expression of CD44 increased again while the expression of CD29 remained at the same level. CD90, CD9, and HSP90β, however, are highly expressed in both undifferentiated and mesenchymal stem cells derived from the bone marrow. HSP90β remained strongly expressed during the entire mesengenic differentiation process while the expression of CD90 and CD9 decreased after 10 days of exposure to SB431542 and increased again by MP1 and MP2, respectively. By MP2, the expression of CD90, CD9, and HSP90β reached levels comparable to those of BM-hMSCs. Lastly, Tra 1-60, SSEA-3, and Oct-4 are only strongly expressed in undifferentiated cells while BM-derived MSCs and ESC/iPSC-derived MSCs lacked expression of these pluripotent stem cell markers. Both Tra 1-60 and SSE-3 remained poorly expressed during the entire mesengenic differentiation process. On the other hand, the expression of Oct-4 decreased after 10 days of exposure to SB431542 and increased slightly after the first passage in MPC Growth MEM media, remaining at this level on subsequent passages. By MP2, the expression of Tra 1-60, SSEA-3, and Oct-4 remained at levels comparable to those of BM-hMSCs. An average of the expression of these markers in all cell lines examined before and during the differentiation process was combined to construct the graphs.

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