Dihydrotestosterone induces SREBP-1 expression and lipogenesis through the phosphoinositide 3-kinase/Akt pathway in HaCaT cells

BACKGROUND: The purpose of this study was to investigate the effects and mechanisms of dihydrotestosterone (DHT)-induced expression of sterol regulatory element binding protein-1 (SREBP-1), and the synthesis and secretion of lipids, in HaCaT cells. HaCaT cells were treated with DHT and either the phosphoinositide 3-kinase inhibitor LY294002 or the extracellular-signal-regulated kinase (ERK) inhibitor PD98059. Real time-PCR, Western blot, Oil Red staining and flow cytometry were employed to examine the mRNA and protein expressions of SREBP-1, the gene transcription of lipid synthesis, and lipid secretion in HaCaT cells. FINDINGS: We found that DHT upregulated mRNA and protein expressions of SREBP-1. DHT also significantly upregulated the transcription of lipid synthesis-related genes and increased lipid secretion, which can be inhibited by the addition of LY294002. CONCLUSIONS: Collectively, these results indicate that DHT induces SREBP-1 expression and lipogenesis in HaCaT cells via activation of the phosphoinositide 3-kinase/Akt Pathway.