Hepatic mTORC1 Opposes Impaired Insulin Action to Control Mitochondrial Metabolism in Obesity.

Published

Journal Article

Dysregulated mitochondrial metabolism during hepatic insulin resistance may contribute to pathophysiologies ranging from elevated glucose production to hepatocellular oxidative stress and inflammation. Given that obesity impairs insulin action but paradoxically activates mTORC1, we tested whether insulin action and mammalian target of rapamycin complex 1 (mTORC1) contribute to altered in vivo hepatic mitochondrial metabolism. Loss of hepatic insulin action for 2 weeks caused increased gluconeogenesis, mitochondrial anaplerosis, tricarboxylic acid (TCA) cycle oxidation, and ketogenesis. However, activation of mTORC1, induced by the loss of hepatic Tsc1, suppressed these fluxes. Only glycogen synthesis was impaired by both loss of insulin receptor and mTORC1 activation. Mice with a double knockout of the insulin receptor and Tsc1 had larger livers, hyperglycemia, severely impaired glycogen storage, and suppressed ketogenesis, as compared to those with loss of the liver insulin receptor alone. Thus, activation of hepatic mTORC1 opposes the catabolic effects of impaired insulin action under some nutritional states.

Full Text

Duke Authors

Cited Authors

  • Kucejova, B; Duarte, J; Satapati, S; Fu, X; Ilkayeva, O; Newgard, CB; Brugarolas, J; Burgess, SC

Published Date

  • July 12, 2016

Published In

Volume / Issue

  • 16 / 2

Start / End Page

  • 508 - 519

PubMed ID

  • 27346353

Pubmed Central ID

  • 27346353

Electronic International Standard Serial Number (EISSN)

  • 2211-1247

Digital Object Identifier (DOI)

  • 10.1016/j.celrep.2016.06.006

Language

  • eng

Conference Location

  • United States