Adropin

Adropin is a peptide encoded by the energy homeostasis-associated gene ENHO,[1] which is highly conserved across mammals.[2]

Predicted structure of Adropin (AlphaFold)

Adropin's biological role was first described in mice by a group led by Andrew Butler, as a protein hormone, secreted from the liver (hepatokine), in the context of obesity and energy homeostasis. They derived the name "Adropin" from the Latin "aduro" - to set fire to, and "pinguis" - fat.[3]

In animals, adropin has been shown to have a regulatory role in carbohydrate/lipid metabolism,[4] as well as in endothelial function.[5][6] Adropin expression in the liver is regulated by feeding status and macronutrient content,[4] as well as by the biological clock. [7] Liver adropin is upregulated by estrogen[8] via ERa.[9]

In humans, lower levels of circulating adropin are associated with several medical conditions including metabolic syndrome, obesity[10] and inflammatory bowel disease.[11]

The brain is the organ with the highest levels of adropin expression.[12] In the brain, adropin has been shown to have a potential protective role role against neurological disease,[13] including in the context of brain aging and cognitive function,[14][15] as well as following acute ischemia.[16]

The orphan G protein-coupled receptor GPR19, has been proposed as a receptor for adropin.[17][18]

In the mouse ovary, adropin and GPR19 are strongly detected in the granulosa cells of large antral follicles and corpus luteum.[19] An additional study suggests a role for adropin in the acceleration of pubertal development.[20]