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

N⁶-methyladenosine (m⁶A) 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 m⁶A 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 m⁶A methylation of PLCβ₃, a key enzyme of the Ca²⁺ signalling pathway, was decreased significantly in the hypothalamus in precocious rats. Upregulating FTO increased PLCβ3 expression and activated the Ca²⁺ signalling pathway, which promoted GnRH expression. Dual-luciferase reporter and MeRIP-qPCR assays confirmed that FTO regulated m⁶A demethylation of PLCβ₃ and promoted PLCβ₃ expression. Upon overexpressing FTO in the hypothalamic arcuate nucleus (ARC) in female rats, we observed advanced puberty onset. Meanwhile, PLCβ₃ and GnRH expression in the hypothalamus increased significantly, and the Ca²⁺ signalling pathway was activated. Our study demonstrates that FTO enhances GnRH expression, which promotes puberty onset, by regulating m⁶A demethylation of PLCβ3 and activating the Ca²⁺ signalling pathway.