When a foe is actually a friend

Identification of a new endocrine hormone pathway implicates a positive role for a pro-inflammatory cytokine in metabolic homeostasis, according to research published this week in Nature Medicine. These results show how inter-organ cross-talk meets acute energy demands while also suggesting alternative avenues for therapy in type 2 diabetes.

The protein interleukin-6 (IL-6) is a pro-inflammatory cytokine and is believed to be detrimental to metabolic well being, especially as it is known to be elevated in states of obesity, though this notion is controversial.

Helga Ellingsgaard and her colleagues found that IL-6 released by muscle in response to exercise elevates the expression of the protein hormone GLP-1 by intestinal cells and pancreatic alpha cells. GLP-1 is known to improve insulin secretion by the pancreas and insulin promotes glucose uptake by cells, so the increase in GLP-1 may be a way by which fuel needs are met after physical activity. Likewise, Ellingsgaard and colleagues found that an injection of recombinant IL-6 increases GLP-1 levels in mouse models of type 2 diabetes and improves their glycemic control.