IGF2BP2-mediated m6A modification of IGF1R mRNA promotes neuronal senescence and cognitive decline in Alzheimer's disease.

Abstract

BACKGROUND: Alzheimer's disease (AD) is characterized by cognitive decline and neuronal loss, with cellular senescence emerging as a key driver. The insulin-like growth factor-1 receptor (IGF1R) pathway is implicated in aging and AD pathology. IGF2 mRNA binding protein 2 (IGF2BP2) can stabilize IGF1R mRNA, but its role in AD-associated neuronal senescence remains unclear. METHODS: We established AD mouse models and HO-induced senescent neuronal cell models to explore the impact of IGF2BP2 in neuronal senescence and cognitive deficits. RNA pull-down assays, methylated RNA immunoprecipitation (MeRIP)-qPCR, and behavioral tests were used to elucidate the molecular mechanisms and therapeutic potential of targeting IGF2BP2. RESULTS: IGF2BP2 was significantly up-regulated in the hippocampal neurons of AD mice. This upregulation correlated with increased β-amyloid (Aβ) deposition, neuronal damage, and cognitive impairments. In vitro, IGF2BP2 knockdown in HO-induced senescent neurons reduced IGF1R expression and alleviated neuronal senescence, as evidenced by decreased senescence-associated secretory phenotype factors and improved cell viability. Mechanistically, IGF2BP2 stabilized IGF1R mRNA through m6A modification, enhancing its expression. Knockdown of IGF2BP2 decreased IGF1R mRNA stability and expression, thereby mitigating neuronal senescence. In AD mice, IGF2BP2 knockdown improved cognitive function, reduced Aβ deposition, and delayed neuronal senescence. CONCLUSION: IGF2BP2 contributes to neuronal senescence and cognitive deficits in AD by regulating IGF1R expression through m6A modification.