Heo JS, Lee SH, Han HJ. Regulation of DNA synthesis in mouse embryonic stem cells by transforming growth factor-alpha: involvement of the PI3-K/Akt and Notch/Wnt signaling pathways.
Growth Factors 2008;
26:104-16. [PMID:
18428029 DOI:
10.1080/08977190802066655]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study examined the mechanisms by which transforming growth factor (TGF)-alpha regulates proliferation of mouse embryonic stem (ES) cells. TGF-alpha increased [3H] thymidine and BrdU incorporation in a time- (0-72 h) and dose-dependent (0-10 ng/ml) manner. TGF-alpha stimulated the phosphorylation of Akt, mammalian target of rapamycin (mTOR), p70S6K1 and p44/42 mitogen-activated protein kinases (MAPKs). TGF-alpha also increased the protein levels of Notch, Notch intracellular domain, Hes-1 and Wnt1. However, TGF-alpha-induced DNA synthesis was blocked by inhibition of Akt, mTOR, p44/42 MAPKs and Notch. TGF-alpha increased the gene expression of c-jun, c-myc and c-fos. Moreover, TGF-alpha increased cyclin D/CDK 4 and cyclin E/CDK 2 levels, while decreasing p21cip1/waf1 and p27kip1, which were blocked by the inhibition of Akt, mTOR and Notch. In conclusion, TGF-alpha regulated DNA synthesis of mouse ES cells via PI3-K/Akt, p44/42 MAPKs and Notch/Wnt pathways.
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