GLP1 receptor induced suppression of food intake and body weight
Full4Health partners from the University of Gothenburg publish in PNAS
Glucagon-like peptide 1 receptor induced suppression of food intake, and body weight is mediated by central IL-1 and IL-6
Glucagon-like peptide 1 (GLP-1), produced in the intestine and the brain, can stimulate insulin secretion from the pancreas and alleviate type 2 diabetes. The cytokine interleukin-6 (IL-6) may enhance insulin secretion from β-cells by stimulating peripheral GLP-1 production. GLP-1 and its analogs also reduce food intake and body weight, clinically beneﬁcial actions that are likely exerted at the level of the CNS, but otherwise are poorly understood. The cytokines IL-6 and interleukin 1β (IL-1β) may exert an anti-obesity effect in the CNS during health. Here we found that central injection of a clinically used GLP-1 receptor agonist, exendin-4, potently increased the expression of IL-6 in the hypothalamus (11-fold) and the hindbrain (4-fold) and of IL-1β in the hypothalamus, without changing the expression of other inﬂammation-associated genes. Furthermore, hypothalamic and hindbrain interleukin-associated intracellular signals [phosphorylated signal transducer and activator of transcription-3 (pSTAT3) and suppressor of cytokine signaling-1 (SOCS1)] were also elevated by exendin-4. Pharmacologic disruption of CNS IL-1 receptor or IL-6 biological activity attenuated anorexia and body weight loss induced by central exendin-4 administration in a rat. Simultaneous blockade of IL-1 and IL-6 activity led to a more potent attenuation of exendin-4 effects on food intake. Mice with global IL-1 receptor gene knockout or central IL-6 receptor knockdown showed attenuated decrease in food intake and body weight in response to peripheral exendin-4 treatment. GLP-1 receptor activation in the mouse neuronal Neuro2A cell line also resulted in increased IL-6 expression. These data outline a previously unidentiﬁed role of the central IL-1 and IL-6 in mediating the anorexic and body weight loss effects of GLP-1 receptor activation.
PNAS 2013 Sep 18 [Epub ahead of print] PMID 24048027