Peroxisome Proliferator–Activated Receptor-α Agonist Treatment in a Transgenic Model of Type 2 Diabetes Reverses the Lipotoxic State and Improves Glucose Homeostasis

• Published in: Diabetes (New York, N.Y.) Vol. 52; no. 7; pp. 1770 - 1778
• Main Authors: KIM, Hyunsook, HALUZIK, Martin, WHEELER, Michael B, LEROITH, Derek, ASGHAR, Zeenat, DAPHNE YAU, JOSEPH, Jamie W, FERNANDEZ, Ana M, REITMAN, Marc L, YAKAR, Shoshana, STANNARD, Bethel, HERON-MILHAVET, Lisa
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Diabetes Association 01.07.2003
• Subjects: Animals; Biological and medical sciences; Diabetes Mellitus, Type 2 - blood; Fundamental and applied biological sciences. Psychology; Gluconeogenesis - drug effects; Glucose - metabolism; Glucose Clamp Technique; Homeostasis; Kinetics; Lipids - blood; Liver - drug effects; Liver - metabolism; Mice; Mice, Inbred Strains; Mice, Transgenic; Muscle, Skeletal - drug effects; Muscle, Skeletal - metabolism; Pyrimidines - pharmacology; Receptor, IGF Type 1 - genetics; Receptor, IGF Type 1 - physiology; Receptors, Cytoplasmic and Nuclear - agonists; Receptors, Cytoplasmic and Nuclear - drug effects; Receptors, Cytoplasmic and Nuclear - genetics; RNA, Messenger - genetics; RNA, Ribosomal, 18S - drug effects; RNA, Ribosomal, 18S - genetics; Time Factors; Transcription Factors - agonists; Transcription Factors - drug effects; Transcription Factors - genetics; Triglycerides - metabolism
• ISSN: 0012-1797; 1939-327X
• DOI: 10.2337/diabetes.52.7.1770

Peroxisome Proliferator–Activated Receptor-α Agonist Treatment in a Transgenic Model of Type 2 Diabetes Reverses the Lipotoxic State and Improves Glucose Homeostasis Hyunsook Kim 1 , Martin Haluzik 1 , Zeenat Asghar 2 , Daphne Yau 2 , Jamie W. Joseph 2 , Ana M. Fernandez 1 , Marc L. Reitman 1 , Shoshana Yakar 1 , Bethel Stannard 1 , Lisa Heron-Milhavet 1 , Michael B. Wheeler 2 and Derek LeRoith 1 1 Diabetes Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 2 Department of Physiology, University of Toronto, Toronto, Ontario, Canada Address correspondence and reprint requests to Derek LeRoith, Molecular and Cellular Physiology Section, Diabetes Branch, NIDDK, National Institutes of Health, 9000 Rockville Pike, Bldg. 10, Rm. 8D12, Bethesda, MD 20892-1758. E-mail: derek{at}helix.nih.gov Abstract Abnormalities in insulin action are the characteristics of type 2 diabetes. Dominant-negative muscle-specific IGF-I receptor (MKR) mice exhibit elevated lipid levels at an early age and eventually develop type 2 diabetes. To evaluate the role of elevated lipids in the progression of the diabetic state, MKR mice were treated with WY14,643, a peroxisome proliferator–activated receptor (PPAR)-α agonist. WY14,643 treatment markedly reduced serum fatty acid and triglyceride levels within a few days, as well as muscle triglyceride levels, and subsequently normalized glucose and insulin levels in MKR mice. Hyperinsulinemic-euglycemic clamp analysis showed that WY14,643 treatment enhanced muscle and adipose tissue glucose uptake by improving whole-body insulin sensitivity. Insulin suppression of endogenous glucose production by the liver of MKR mice was also improved. The expression of genes involved in fatty acid oxidation was increased in liver and skeletal muscle, whereas gene expression levels of hepatic gluconeogenic enzymes were decreased in WY14,643-treated MKR mice. WY14,643 treatment also improved the pattern of glucose-stimulated insulin secretion from the perfused pancreata of MKR mice and reduced the β-cell mass. Taken together, these findings suggest that the reduction in circulating or intracellular lipids by activation of PPAR-α improved insulin sensitivity and the diabetic condition of MKR mice. ACO, acyl-CoA oxidase BrdU, 5-bromo-2′deoxyuridine CPT-1, carnitine palmitoyl transferase 1 FA, fatty acid IGF-IR, IGF-I receptor PPAR, peroxisome proliferator–activated receptor Footnotes M.L.R. is an employee of Merck. Accepted April 4, 2003. Received December 10, 2002. DIABETES