Hepatocyte-specific HIF-1α ablation improves obesity-induced glucose intolerance by reducing first-pass GLP-1 degradation

Sci Adv. 2019 Jul 3;5(7):eaaw4176. doi: 10.1126/sciadv.aaw4176. eCollection 2019 Jul.

Abstract

The decrease in incretin effects is an important etiologic component of type 2 diabetes with unknown mechanisms. In an attempt to understand obesity-induced changes in liver oxygen homeostasis, we found that liver HIF-1α expression was increased mainly by soluble factors released from obese adipocytes, leading to decreased incretin effects. Deletion of hepatocyte HIF-1α protected obesity-induced glucose intolerance without changes in body weight, liver steatosis, or insulin resistance. In-depth mouse metabolic phenotyping revealed that obesity increased first-pass degradation of an incretin hormone GLP-1 with increased liver DPP4 expression and decreased sinusoidal blood flow rate, reducing active GLP-1 levels in peripheral circulation. Hepatocyte HIF-1α KO blocked these changes induced by obesity. Deletion of hepatocyte HIF-2α did not change liver DPP4 expression but improved hepatic steatosis. Our results identify a previously unknown pathway for obesity-induced impaired beta cell glucose response (incretin effects) and the development of glucose intolerance through inter-organ communications.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adipose Tissue / metabolism
  • Adipose Tissue / physiopathology
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Diet, High-Fat / adverse effects
  • Dipeptidyl Peptidase 4 / metabolism
  • Fatty Liver / etiology
  • Fatty Liver / metabolism
  • Glucagon-Like Peptide 1 / metabolism*
  • Glucose / metabolism
  • Hepatitis / etiology
  • Hepatocytes / metabolism*
  • Insulin Resistance
  • Liver / blood supply
  • Liver / metabolism
  • Male
  • Mice, Knockout
  • Obesity / etiology*

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • endothelial PAS domain-containing protein 1
  • Glucagon-Like Peptide 1
  • Dipeptidyl Peptidase 4
  • Dpp4 protein, mouse
  • Glucose