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Orexin A stimulates glucose uptake, lipid accumulation and adiponectin secretion from 3T3-L1 adipocytes and isolated

M Skrzypski1, T T Le, P Kaczmarek

  • 1Department of Hepatology and Gastroenterology and Interdisciplinary Centre of Metabolism: Endocrinology, Diabetes and Metabolism, Charité-University Medicine Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.

Diabetologia
|April 21, 2011
PubMed
Abstract

Insights

Orexin A (OXA) enhances glucose uptake and lipid storage in adipocytes by activating PI3K and PPARγ2 pathways. This peptide also boosts adiponectin secretion, suggesting potential therapeutic applications for metabolic disorders.

Area of Science:

  • Metabolic research
  • Endocrinology
  • Adipocyte biology

Background:

  • Orexin A (OXA) is known to influence body weight and energy balance.
  • In vitro studies suggest OXA regulates lipid metabolism by increasing PPARγ expression and inhibiting lipolysis.

Purpose of the Study:

  • To investigate the metabolic effects and underlying mechanisms of Orexin A (OXA) action in adipocytes.
  • To characterize OXA's impact on glucose uptake, lipid metabolism, and adiponectin secretion.

Main Methods:

  • Experiments involved isolated rat adipocytes and 3T3-L1 adipocytes treated with OXA.
  • Key pathways investigated included phosphoinositide 3-kinase (PI3K) and peroxisome proliferator-activated receptor γ (PPARγ).
  • Measurements included glucose uptake, GLUT4 translocation, lipogenesis, lipolysis, and adiponectin secretion.

Main Results:

  • OXA stimulated glucose uptake and GLUT4 translocation via PI3K.
  • Cellular triacylglycerol content increased due to enhanced lipogenesis and reduced lipolysis.
  • OXA treatment increased adiponectin levels, expression, and secretion, effects dependent on PI3K and PPARγ2.

Conclusions:

  • OXA promotes glucose uptake and lipid storage in adipocytes through PI3K and PPARγ2 signaling.
  • The peptide inhibits lipolysis and stimulates adiponectin secretion.
  • OXA's metabolic profile suggests potential relevance in treating metabolic disorders, similar to insulin sensitizers.

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