title: Depot-Specific Changes in Fat Metabolism with Aging in a Type 2 Diabetic Animal Model.
abstract: Visceral fat accretion is a hallmark of aging and is associated with aging-induced metabolic dysfunction. PPARγ agonist was reported to improve insulin sensitivity by redistributing fat from visceral fat to subcutaneous fat. The purpose of this study was to investigate the underlying mechanisms by which aging affects adipose tissue remodeling in a type 2 diabetic animal model and through which PPARγ activation modulates aging-related fat tissue distribution. At the ages of 21, 31 and 43 weeks, OLETF rats as an animal model of type 2 diabetes were evaluated for aging-related effects on adipose tissue metabolism in subcutaneous and visceral fat depots. During aging, the ratio of visceral fat weight to subcutaneous fat weight (V/S ratio) increased. Aging significantly increased the mRNA expression of genes involved in lipogenesis such as lipoprotein lipase, fatty acid binding protein aP2, lipin 1, and diacylglycerol acyltransferase 1, which were more prominent in visceral fat than subcutaneous fat. The mRNA expression of adipose triglyceride lipase, which is involved in basal lipolysis and fatty acid recycling, was also increased, more in visceral fat compared to subcutaneous fat during aging. The mRNA levels of the genes associated with lipid oxidation were increased, whereas the mRNA levels of genes associated with energy expenditure showed no significant change during aging. PPARγ agonist treatment in OLETF rats resulted in fat redistribution with a decreasing V/S ratio and improved glucose intolerance. The genes involved in lipogenesis decreased in visceral fat of the PPARγ agonist-treated rats. During aging, fat distribution was changed by stimulating lipid uptake and esterification in visceral fat rather than subcutaneous fat, and by altering the lipid oxidation.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
authors.affiliation: Diabetes Research Institute, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jung Mook
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Diabetes Research Institute, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eugene
authors.initials: E
authors.lastname: Chang
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Rhee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won-Young
authors.initials: WY
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Oh
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Park
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University, College of Medicine, Seoul, Korea.
authors.forename: Eun Seok
authors.initials: ES
authors.lastname: Kang
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University, College of Medicine, Seoul, Korea.
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Lee
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University, College of Medicine, Seoul, Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Cha
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D050154:Adiposity / Q000235:genetics; D000375:Aging / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D004734:Energy Metabolism; D005223:Fats / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D050152:Intra-Abdominal Fat / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D010084:Oxidation-Reduction; D047495:PPAR gamma / Q000819:agonists / Q000378:metabolism; D051381:Rats; D014280:Triglycerides / Q000096:biosynthesis
chemical_list: D005223:Fats; D005227:Fatty Acids; D047495:PPAR gamma; D014280:Triglycerides; D005947:Glucose