Adropin regulates hepatic glucose production via PP2A/AMPK pathway in insulin-resistant hepatocytes

FASEB J. 2020 Aug;34(8):10056-10072. doi: 10.1096/fj.202000115RR. Epub 2020 Jun 24.

Abstract

Adropin as a secretory peptide has shown a protective role on the disorders of glucose and lipid metabolism. However, the role and mechanism of this peptide on the hepatic glucose production has remained unclear. Adropin knockout (KO) mice were generated to explore its effects on the enhanced hepatic glucose production in obesity. We found that compared to wild-type (WT) mice, adropin-KO mice developed the unbalanced enhanced hepatic glucose production in advance of the whole-body insulin resistance (IR) by high-fat diet (HFD). Mechanistically, adropin dissociated CREB-CRTC2 and FoxO1-PGC1α complex and reduced their binding to the promoters of G6Pase and PEPCK to decrease glucose production in IR. However, these effects were not observed in insulin-sensitive hepatocytes. Furthermore, in IR hepatocytes, dampened AMPK signaling was re-activated by adropin treatment via inhibition of PP2A. To further authenticate AMPK role in vivo, we administrated HFD-fed mice with AAV8-CA AMPKα and found that AMPK activation functionally restored the aberrant glucose production and IR induced by adropin-deficiency. This study provides evidence that adropin activates the AMPK pathway via inhibition of PP2A and decreases the liver glucose production in IR context. Therefore, adropin may represent a novel target for the prevention and treatment of diabetes.

Keywords: AMPK; diabetes; gluconeogenesis; obesity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Cell Line, Tumor
  • Cells, Cultured
  • Cyclic AMP Response Element-Binding Protein / metabolism
  • Diet, High-Fat / methods
  • Forkhead Box Protein O1 / metabolism
  • Glucose / metabolism*
  • HEK293 Cells
  • Hep G2 Cells
  • Hepatocytes / metabolism*
  • Humans
  • Insulin / metabolism*
  • Insulin Resistance / physiology*
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism
  • Protein Phosphatase 2 / metabolism*
  • Signal Transduction / physiology
  • Transcription Factors / metabolism

Substances

  • Cyclic AMP Response Element-Binding Protein
  • Enho protein, mouse
  • Forkhead Box Protein O1
  • Insulin
  • Intercellular Signaling Peptides and Proteins
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Transcription Factors
  • AMP-Activated Protein Kinases
  • Protein Phosphatase 2
  • Glucose