title: Effects of lipoic acid on apelin in 3T3-L1 adipocytes and in high-fat fed rats.
abstract: Lipoic acid (LA) is an antioxidant with therapeutic properties on several diseases like diabetes and obesity. Apelin is a novel adipokine with potential beneficial actions on glucose metabolism and insulin resistance. The aim of this study was to examine in 3T3-L1 adipocytes the effects of LA on apelin gene expression and secretion, as well as elucidate the signaling pathways involved. We also tested the regulation of adipose apelin gene expression by LA supplementation in a model of high-fat diet-induced obesity. LA increased apelin secretion but not apelin gene expression in 3T3-L1 adipocytes. The AMPK inhibitor Compound C induced an increase in LA-stimulated apelin production, and, on the contrary, the AMPK activator AICAR completely reversed the LA stimulatory effects on apelin secretion, also inducing a significant reduction in apelin mRNA levels in this in vitro model. Apelin mRNA levels were increased in those animals fed with the high-fat diet, while the caloric restriction decreased apelin mRNA to control levels. However, apelin gene expression was not significantly modified in rats treated with LA compared with the obese group. The current data suggest the ability of LA to modulate apelin secretion by adipocytes. However the insulin-sensitizing effect of LA in vivo is not related to changes in apelin gene expression in our model of diet-induced obesity.
authors: Department of Nutrition, Food Science, Physiology and Toxicology, University of Navarra, C/Irunlarrea 1, Pamplona, Spain.
authors: Marta
authors: M
authors: Fernández-Galilea
authors: Patricia
authors: P
authors: Pérez-Matute
authors: Pedro
authors: P
authors: Prieto-Hontoria
authors: J Alfredo
authors: JA
authors: Martínez
authors: María Jesús
authors: MJ
authors: Moreno-Aliaga
mesh_terms: D041721:3T3-L1 Cells; D052438:Adipocytes, White / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D000073861:Apelin; D001786:Blood Glucose / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology; D059305:Diet, High-Fat / Q000009:adverse effects*; D019587:Dietary Supplements; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000097:blood; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D009025:Morpholines / Q000494:pharmacology; D009765:Obesity / Q000209:etiology / Q000517:prevention & control*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D008063:Thioctic Acid / Q000494:pharmacology*
chemical_list: D000073861:Apelin; C498579:Apln protein, rat; D001786:Blood Glucose; D002867:Chromones; D007328:Insulin; D036341:Intercellular Signaling Peptides and Proteins; D009025:Morpholines; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D008063:Thioctic Acid; D005947:Glucose