RAF1 in AgRP neurons involved in the regulation of energy metabolism via the MAPK signaling pathway.

V-raf-leukemia viral oncogene 1 (RAF1), a serine/threonine protein kinase, is well established to play a crucial role in tumorigenesis and cell development. However, the specific role of hypothalamic RAF1 in regulating energy metabolism remains unknown. In this study, we found that the expression of RAF1 was significantly increased in hypothalamic AgRP neurons of diet-induced obesity (DIO) mice. Under normal chow diet feeding, overexpression of Raf1 in AgRP neurons led to obesity in mice characterized by increased body weight, fat mass, and impaired glucose tolerance. Conversely, Raf1 knockout in AgRP neurons protected against diet-induced obesity, reducing fat mass and improving glucose tolerance. Mechanistically, Raf1 activated the MAPK signaling pathway, culminating in the phosphorylation of cAMP response element-binding protein (CREB), which enhanced transcription of Agrp and Npy. Insulin stimulation further potentiated the RAF1-MEK1/2-ERK1/2-CREB axis, highlighting RAF1's role in integrating hormonal and nutritional signals to regulate energy balance. Collectively, these findings underscore the important role of RAF1 in AgRP neurons in maintaining energy homeostasis and obesity pathogenesis, positioning it and its downstream pathways as potential therapeutic targets for innovative strategies to combat obesity and related metabolic diseases.