Deura C, Kimura Y, Nonoyama T, Moriyama R. Gpr120 mRNA expression in gonadotropes in the mouse pituitary gland is regulated by free fatty acids.
J Reprod Dev 2020;
66:249-254. [PMID:
32115468 PMCID:
PMC7297631 DOI:
10.1262/jrd.2019-166]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
GPR120 is a long-chain fatty acid (LCFA) receptor that is specifically expressed in gonadotropes in the anterior pituitary gland in mice. The aim of this study was to investigate
whether GPR120 is activated by free fatty acids in the pituitary of mice and mouse immortalized gonadotrope LβT2 cells. First, the effects of palmitate on GPR120, gonadotropic
hormone b-subunits, and GnRH-receptor expression in gonadotropes were investigated in vitro. We observed palmitate-induced an increase in Gpr120
mRNA expression and a decrease in follicle-stimulating hormone b-subunit (Fshb) expression in LβT2 cells. Furthermore, palmitate exposure caused the
phosphorylation of ERK1/2 in LβT2 cells, but no significant changes were observed in the expression levels of luteinizing hormone b-subunit (Lhb) and gonadotropin
releasing hormone-receptor (Gnrh-r) mRNA and number of GPR120 immunoreactive cells. Next, diurnal variation in Gpr120 mRNA expression in the male
mouse pituitary gland was investigated using ad libitum and night-time restricted feeding (active phase from 1900 to 0700 h) treatments. In ad
libitum feeding group mice, Gpr120 mRNA expression at 1700 h was transiently higher than that measured at other times, and the peak blood non-esterified
fatty acid (NEFA) levels were observed from 1300 to 1500 h. These results were not observed in night-time-restricted feeding group mice. These results suggest that GPR120 is
activated by LCFAs to regulate follicle stimulating hormone (FSH) synthesis in the mouse gonadotropes.
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