Hepatocyte-secreted DPP4 in obesity promotes adipose inflammation and insulin resistance

Nature. 2018 Mar 29;555(7698):673-677. doi: 10.1038/nature26138. Epub 2018 Mar 21.

Abstract

Obesity-induced metabolic disease involves functional integration among several organs via circulating factors, but little is known about crosstalk between liver and visceral adipose tissue (VAT). In obesity, VAT becomes populated with inflammatory adipose tissue macrophages (ATMs). In obese humans, there is a close correlation between adipose tissue inflammation and insulin resistance, and in obese mice, blocking systemic or ATM inflammation improves insulin sensitivity. However, processes that promote pathological adipose tissue inflammation in obesity are incompletely understood. Here we show that obesity in mice stimulates hepatocytes to synthesize and secrete dipeptidyl peptidase 4 (DPP4), which acts with plasma factor Xa to inflame ATMs. Silencing expression of DPP4 in hepatocytes suppresses inflammation of VAT and insulin resistance; however, a similar effect is not seen with the orally administered DPP4 inhibitor sitagliptin. Inflammation and insulin resistance are also suppressed by silencing expression of caveolin-1 or PAR2 in ATMs; these proteins mediate the actions of DPP4 and factor Xa, respectively. Thus, hepatocyte DPP4 promotes VAT inflammation and insulin resistance in obesity, and targeting this pathway may have metabolic benefits that are distinct from those observed with oral DPP4 inhibitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Caveolin 1 / deficiency
  • Caveolin 1 / genetics
  • Caveolin 1 / metabolism
  • Dipeptidyl Peptidase 4 / deficiency
  • Dipeptidyl Peptidase 4 / genetics
  • Dipeptidyl Peptidase 4 / metabolism*
  • Factor Xa / metabolism
  • Hepatocytes / drug effects
  • Hepatocytes / enzymology
  • Hepatocytes / metabolism*
  • Humans
  • Inflammation / enzymology*
  • Inflammation / genetics
  • Inflammation / metabolism
  • Insulin Resistance* / genetics
  • Intra-Abdominal Fat / metabolism
  • Intra-Abdominal Fat / pathology*
  • Macrophages / metabolism
  • Male
  • Mice
  • Mice, Obese
  • Obesity / enzymology*
  • Obesity / genetics
  • Obesity / metabolism
  • Receptor, PAR-2 / deficiency
  • Receptor, PAR-2 / genetics
  • Receptor, PAR-2 / metabolism
  • Sitagliptin Phosphate / administration & dosage
  • Sitagliptin Phosphate / pharmacology

Substances

  • Caveolin 1
  • Receptor, PAR-2
  • DPP4 protein, human
  • Dipeptidyl Peptidase 4
  • Dpp4 protein, mouse
  • Factor Xa
  • Sitagliptin Phosphate