Deleting Ghrelin Receptor, but Not Ghrelin, Turns Up Fat-Burning Thermostat

Deleting the receptor, not the protein ghrelin itself, turns up the body's fat-burning thermostat, giving aging mice an exothermic boost toward a svelte physique, researchers reported at the American Society of Cell Biology's 50th Annual Meeting in Philadelphia.

The protein's receptor, growth hormone secretagogue receptor (GHS-R), might make a better target than ghrelin for treating obesity, according to Yuxiang Sun, M.D., Ph.D., of the Baylor College of Medicine in Houston, TX.

Sun said that experimentally deleting the receptor from the body cells of laboratory mice prevented obesity by diminishing white adipose tissues and activating brown adipose tissue, thereby increasing heat production.

The new finding that ghrelin may not be as critical to energy expenditure as its receptor, GHS-R, came from research on body temperature regulation at Baylor, Sun explained. GHS-R acts as the "lock" for the "key-like" ligand ghrelin to dock; GHS-R subsequently activates down-stream metabolic signal pathways...