Selective deletion of FGFR1 in AgRP neurons impairs energy homeostasis under high-fat diet in mice.

The global obesity crisis and the limited success of current treatments underscore the need to identify novel regulatory pathways. While central administration of α-Klotho exerts anti-obesity effects in rodents through AgRP neurons, the intracellular signaling mechanisms that mediate this process remain undefined. To define the role of FGFR1 within the α-Klotho signaling pathway in AgRP neurons, we performed a targeted deletion of the receptor in adult mice using an AAV-mediated CRISPR/Cas9 system alongside transgenic models. Deletion of FGFR1 in AgRP neurons disrupted energy homeostasis, promoting weight gain induced by a high-fat diet. Electrophysiological recordings revealed that FGFR1 loss increased the intrinsic firing rate of AgRP neurons and abolished the suppressive effect of α-Klotho on their activity. At the molecular level, FGFR1 knockdown decreased phosphorylation of the transcription factor FOXO1 and elevated AgRP mRNA expression. Our results define a crucial FGFR1 signaling axis in AgRP neurons that coordinately regulates their electrical activity and peptide expression, thereby establishing FGFR1 as an essential regulator of energy homeostasis.