leptin

Leptin is a protein hormone primarily produced by adipose (fat) tissue that plays a central role in regulating energy homeostasis, appetite, and metabolism. It acts as an appetite suppressant by signaling the hypothalamus in the brain to reduce food intake and increase energy expenditure. Leptin binds to its receptor (leptin receptor/ObR), which belongs to the class I cytokine family of receptors. The main intracellular signaling pathways activated by leptin include JAK-STAT, PI3K, ERK/MAPK, and mTOR. These pathways mediate effects on neuroendocrine function, immune regulation (including modulation of T lymphocyte responses), inflammation control via cytokine production (e.g., IL-1RA, IL-6, TNF-alpha), and metabolic processes such as glucose homeostasis and lipid metabolism[2][6][8]. Leptin deficiency or resistance can lead to increased appetite and severe metabolic disturbances; recombinant analogs like metreleptin are used therapeutically for congenital or acquired generalized lipodystrophy[1][5].

Other names

OB proteinobesity factorsatiety hormone