Amyloid-β induces hepatic insulin resistance by activating JAK2/STAT3/SOCS-1 signaling pathway

Diabetes. 2012 Jun;61(6):1434-43. doi: 10.2337/db11-0499. Epub 2012 Apr 20.

Abstract

Epidemiological studies indicate that patients with Alzheimer's disease (AD) have an increased risk of developing type 2 diabetes mellitus (T2DM), and experimental studies suggest that AD exacerbates T2DM, but the underlying mechanism is still largely unknown. This study aims to investigate whether amyloid-β (Aβ), a key player in AD pathogenesis, contributes to the development of insulin resistance, as well as the underlying mechanism. We find that plasma Aβ40/42 levels are increased in patients with hyperglycemia. APPswe/PSEN1dE9 transgenic AD model mice with increased plasma Aβ40/42 levels show impaired glucose and insulin tolerance and hyperinsulinemia. Furthermore, Aβ impairs insulin signaling in mouse liver and cultured hepatocytes. Aβ can upregulate suppressors of cytokine signaling (SOCS)-1, a well-known insulin signaling inhibitor. Knockdown of SOCS-1 alleviates Aβ-induced impairment of insulin signaling. Moreover, JAK2/STAT3 is activated by Aβ, and inhibition of JAK2/STAT3 signaling attenuates Aβ-induced upregulation of SOCS-1 and insulin resistance in hepatocytes. Our results demonstrate that Aβ induces hepatic insulin resistance by activating JAK2/STAT3/SOCS-1 signaling pathway and have implications toward resolving insulin resistance and T2DM.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / genetics
  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Blood Glucose / metabolism
  • Diabetes Mellitus, Type 2 / metabolism
  • Fasting / metabolism
  • Glucose Tolerance Test
  • Hepatocytes / metabolism
  • Humans
  • Hyperglycemia / metabolism
  • Insulin / metabolism
  • Insulin Resistance / physiology*
  • Janus Kinase 2 / metabolism*
  • Liver / metabolism*
  • Mice
  • Mice, Transgenic
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction / physiology
  • Suppressor of Cytokine Signaling 1 Protein
  • Suppressor of Cytokine Signaling Proteins / metabolism*

Substances

  • Amyloid beta-Peptides
  • Blood Glucose
  • Insulin
  • STAT3 Transcription Factor
  • Socs1 protein, mouse
  • Suppressor of Cytokine Signaling 1 Protein
  • Suppressor of Cytokine Signaling Proteins
  • Janus Kinase 2