FTO-mediated m6A demethylation regulates GnRH expression in the hypothalamus via the PLCβ3/Ca2+/CAMK signalling pathway

Abstract

Abstract N 6 -methyladenosine (m 6 A) plays a crucial role in the development and functional homeostasis of the central nervous system. The fat mass and obesity-associated ( FTO ) gene, which is highly expressed in the hypothalamus, is closely related to female pubertal development. In this study, we found that m 6 A methylation decreased in the hypothalamus gradually with puberty and decreased in female rats with precocious puberty. FTO expression was increased at the same time. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) showed that the m 6 A methylation of PLCβ 3 , a key enzyme of the Ca 2+ signalling pathway, was decreased significantly in the hypothalamus in precocious rats. Upregulating FTO increased PLCβ3 expression and activated the Ca 2+ signalling pathway, which promoted GnRH expression. Dual-luciferase reporter and MeRIP-qPCR assays confirmed that FTO regulated m 6 A demethylation of PLCβ 3 and promoted PLCβ 3 expression. Upon overexpressing FTO in the hypothalamic arcuate nucleus (ARC) in female rats, we observed advanced puberty onset. Meanwhile, PLCβ 3 and GnRH expression in the hypothalamus increased significantly, and the Ca 2+ signalling pathway was activated. Our study demonstrates that FTO enhances GnRH expression, which promotes puberty onset, by regulating m 6 A demethylation of PLCβ3 and activating the Ca 2+ signalling pathway.