Lipopolysaccharide Stimulates Proopiomelanocortin Gene Expression in AtT20 Corticotroph Cells

Endocrine Journal

Kozo HASHIMOTO¹  Masato ASAI²  Masanori YOSHIDA²  Mitsuru NISHIYAMA¹  Toshihiro TAKAO¹  Yasumasa IWASAKI¹  Machiko KAMBAYASHI¹  Takafumi TAGUCHI¹ 

[1] Department of Endocrinology, Metabolism, and Nephrology, Kochi Medical School, Kochi University;Department of Medicine, Nagoya University Graduate School of Medicine

关键词: Proopiomelanocortin;    Lipopolysaccharide;    Toll-like receptor;    Innate immunity;   

DOI  :  10.1507/endocrj.K07-075

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(18)Cited-By(8)While lipopolysaccharides (LPS) are known to activate the hypothalamo-pituitary-adrenal axis, their direct effects on proopiomelanocortin (POMC) and adrenocorticotropin (ACTH) expression at the pituitary level through Toll-like receptors (TLRs) remain unclear. In this study, we examined the effects of LPS on ACTH secretion and the transcription of the POMC gene in the AtT20 mouse pituitary corticotroph cell line. RT-PCR analysis showed that TLR1-4 and 6 subtype mRNAs were expressed in AtT20 cells. When the cells were treated with LPS, a significant increase in the 5'-promoter activity of POMC gene was observed at 24 h, without any stimulatory effect on ACTH secretion. LPS also stimulated the expression of c-Fos gene and protein, and AP1-, but not NF-κB-, mediated transcription. Overall, our data show the expression of TLRs in the pituitary corticotroph cells, and suggest the direct stimulatory effect of LPS on POMC gene expression via TLR (probably TLR4), although the intracellular signaling pathways in the corticotroph may be different from those in immune cells.

【 授权许可】

Unknown