Angiotensin II receptor blocker ameliorates stress-induced adipose tissue inflammation and insulin resistance

PLoS One. 2014 Dec 31;9(12):e116163. doi: 10.1371/journal.pone.0116163. eCollection 2014.

Abstract

A strong causal link exists between psychological stress and insulin resistance as well with hypertension. Meanwhile, stress-related responses play critical roles in glucose metabolism in hypertensive patients. As clinical trials suggest that angiotensin-receptor blocker delays the onset of diabetes in hypertensive patients, we investigated the effects of irbesartan on stress-induced adipose tissue inflammation and insulin resistance. C57BL/6J mice were subjected to 2-week intermittent restraint stress and orally treated with vehicle, 3 and 10 mg/kg/day irbesartan. The plasma concentrations of lipid and proinflammatory cytokines [Monocyte Chemoattractant Protein-1 (MCP-1), tumor necrosis factor-α, and interleukin-6] were assessed with enzyme-linked immunosorbent assay. Monocyte/macrophage accumulation in inguinal white adipose tissue (WAT) was observed with CD11b-positive cell counts and mRNA expressions of CD68 and F4/80 using immunohistochemistry and RT-PCR methods respectively. The mRNA levels of angiotensinogen, proinflammatory cytokines shown above, and adiponectin in WAT were also assessed with RT-PCR method. Glucose metabolism was assessed by glucose tolerance tests (GTTs) and insulin tolerance tests, and mRNA expression of insulin receptor substrate-1 (IRS-1) and glucose transporter 4 (GLUT4) in WAT. Restraint stress increased monocyte accumulation, plasma free fatty acids, expression of angiotensinogen and proinflammatory cytokines including MCP-1, and reduced adiponectin. Irbesartan reduced stress-induced monocyte accumulation in WAT in a dose dependent manner. Irbesartan treatment also suppressed induction of adipose angiotensinogen and proinflammatory cytokines in WAT and blood, and reversed changes in adiponectin expression. Notably, irbesartan suppressed stress-induced reduction in adipose tissue weight and free fatty acid release, and improved insulin tolerance with restoration of IRS-1 and GLUT4 mRNA expressions in WAT. The results indicate that irbesartan improves stress-induced adipose tissue inflammation and insulin resistance. Our results suggests that irbesartan treatment exerts additive benefits for glucose metabolism in hypertensive patients with mental stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adipokines / genetics
  • Adipose Tissue, White / drug effects
  • Adipose Tissue, White / metabolism
  • Angiotensin II Type 1 Receptor Blockers / pharmacology*
  • Angiotensinogen / genetics
  • Animals
  • Biphenyl Compounds / pharmacology*
  • Chemokine CCL2 / blood
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Insulin Resistance* / physiology
  • Irbesartan
  • Lipolysis / drug effects
  • Male
  • Mice, Inbred C57BL
  • Panniculitis / drug therapy*
  • Panniculitis / etiology
  • Panniculitis / metabolism
  • Stress, Physiological
  • Tetrazoles / pharmacology*

Substances

  • Adipokines
  • Angiotensin II Type 1 Receptor Blockers
  • Biphenyl Compounds
  • Ccl2 protein, mouse
  • Chemokine CCL2
  • Tetrazoles
  • Angiotensinogen
  • Irbesartan

Grants and funding

This study was supported by research grants from SENSHIN Medical Research Foundation (to KT), Suzuken Memorial Foundation (to KT), and a Grant-in-Aid for Scientific Research (Kakenhi 25461336 to KT). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.