Downregulation of SGK1 Expression is Critical for TGF-β-induced Apoptosis in Mouse Hepatocytes Cells

Transforming growth factor (TGF)-β-dependent apoptosis is important in the elimination of damaged or abnormal cells from normal tissues, especially in liver, in vivo. To investigate which gene expressions are critical for TGF-β-induced apoptosis in hepatocytes, gene expression profiling experiments were performed with TGF-β-treated and non-treated mouse hepatocytes AML12 cells. Findings showed that serum and glucocorticoid-inducible protein kinase1 (SGK1) expression is markedly downregulated during TGF-β-induced apoptosis. Findings confirmed that expression of SGK1 protein, as well as mRNA, is also markedly decreased with TGF-β treatment. Infection of adenoviral vector encoding constitutively active SGK1 (CA-SGK1), but not kinase dead SGK1 (KD-SGK1), attenuated TGF-β-induced apoptosis. All of these results suggest that downregulation of SGK1 expression is critical for TGF-β-induced apoptosis in AML12 cells.

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