[HTML][HTML] Insulin action in AgRP-expressing neurons is required for suppression of hepatic glucose production

AC Könner, R Janoschek, L Plum, SD Jordan, E Rother… - Cell metabolism, 2007 - cell.com
AC Könner, R Janoschek, L Plum, SD Jordan, E Rother, X Ma, C Xu, P Enriori, B Hampel…
Cell metabolism, 2007cell.com
Insulin action in the central nervous system regulates energy homeostasis and glucose
metabolism. To define the insulin-responsive neurons that mediate these effects, we
generated mice with selective inactivation of the insulin receptor (IR) in either pro-
opiomelanocortin (POMC)-or agouti-related peptide (AgRP)-expressing neurons of the
arcuate nucleus of the hypothalamus. While neither POMC-nor AgRP-restricted IR knockout
mice exhibited altered energy homeostasis, insulin failed to normally suppress hepatic …
Summary
Insulin action in the central nervous system regulates energy homeostasis and glucose metabolism. To define the insulin-responsive neurons that mediate these effects, we generated mice with selective inactivation of the insulin receptor (IR) in either pro-opiomelanocortin (POMC)- or agouti-related peptide (AgRP)-expressing neurons of the arcuate nucleus of the hypothalamus. While neither POMC- nor AgRP-restricted IR knockout mice exhibited altered energy homeostasis, insulin failed to normally suppress hepatic glucose production during euglycemic-hyperinsulinemic clamps in AgRP-IR knockout (IRΔAgRP) mice. These mice also exhibited reduced insulin-stimulated hepatic interleukin-6 expression and increased hepatic expression of glucose-6-phosphatase. These results directly demonstrate that insulin action in POMC and AgRP cells is not required for steady-state regulation of food intake and body weight. However, insulin action specifically in AgRP-expressing neurons does play a critical role in controlling hepatic glucose production and may provide a target for the treatment of insulin resistance in type 2 diabetes.
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