Pioglitazone Enhances β-Arrestin2 Signaling and Ameliorates Insulin Resistance in Classical Insulin Target Tissues

Shaimaa El-Fayoumi1,2, Rehab Mansour1,3, Amr Mahmoud1,4

  • 1Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt.

Pharmacology
|June 3, 2021
PubMed
Abstract

Insights

Pioglitazone enhances insulin sensitivity by increasing beta-arrestin2 signaling in key tissues like the liver and muscle. This study reveals a new mechanism for this antidiabetic drug.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Pharmacology

Background:

  • Pioglitazone is an oral antidiabetic agent belonging to the thiazolidinedione class.
  • Insulin resistance is a hallmark of type 2 diabetes, affecting major metabolic tissues.
  • Beta-arrestin2 signaling plays a role in cellular responses to insulin.

Purpose of the Study:

  • To investigate the impact of pioglitazone on beta-arrestin2 signaling.
  • To determine if pioglitazone's insulin-sensitizing effects involve beta-arrestin2.
  • To examine these effects in classical insulin target tissues.

Main Methods:

  • Mice were divided into three groups: standard chow, high-fructose, high-fat diet (HFrHFD), and HFrHFD with pioglitazone treatment.
  • Pioglitazone was administered orally for the final four weeks of the HFrHFD feeding period.
  • Insulin sensitivity, beta-arrestin2 levels, and downstream signaling molecules were assessed.

Main Results:

  • Pioglitazone treatment significantly improved insulin sensitivity, indicated by a reduced insulin resistance index.
  • Beta-arrestin2 levels and signaling were significantly increased in adipose tissue, liver, and skeletal muscle of treated mice.
  • Key signaling molecules, including phosphatidylinositol 4,5 bisphosphate and phosphorylated Akt, were elevated, while diacylglycerol was reduced.

Conclusions:

  • This study identifies a novel mechanism for pioglitazone's action in enhancing insulin sensitivity.
  • Pioglitazone's beneficial effects are linked to increased beta-arrestin2 signaling in insulin target tissues.
  • The findings contribute to understanding pioglitazone's role in metabolic regulation.

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