Brainstem receptor regulates body mass loss

Growth and differentiation factor 15 (GDF15) acts on feeding centres in the brain to cause anorexia, leading to loss of both lean and fat mass and eventually cachexia. GDF15 levels rise in response to tissue stress and injury, and higher levels are associated with weight loss in numerous chronic human diseases, including cancer. Bernard Allan and colleagues now show that glial cell-derived neurotrophic factor (GDNF) receptor alpha-like (GFRAL) is a GDF15 receptor in the brainstem. The structure of GDF15 and its interaction with GFRAL together with biochemical experiments and analysis of Gfral knockout mice demonstrate that regulation of body weight by GFRAL is independent of previously characterized pathways. Unlike hormones from gut and adipose tissue that activate receptors mostly in the hypothalamus, GDF15 increases in response to tissue damage and activates GFRAL-expressing neurons in the brainstem. Gfral knockout mice overate under stressed conditions and were resistant to chemotherapy-induced anorexia and weight loss. These findings provide therapeutic opportunities for disorders with altered energy demands.