TY - JOUR
T1 - The role of leptin resistance in the lipid abnormalities of aging
AU - Wang, Z. W.
AU - Pan, W. T.
AU - Lee, Young H
AU - Kakuma, T.
AU - Zhou, Y. T.
AU - Unger, Roger H
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - Leptin resistance has been implicated in the pathogenesis of obesity-related complications involving abnormalities of lipid metabolism that resemble those of old age. To determine whether development of leptin resistance in advancing age might account for such abnormalities, we compared the effects of hyperleptinemia (>40 ng/ml) induced in 2-month-old and 18-month-old lean wild-type (+/+) Zucker diabetic fatty rats by adenovirus gene transfer. The decline in food intake, body weight, and body fat in old rats was only 25%, 50%, and 16%, respectively, of the young rats. Whereas in young rats plasma free fatty acids fell 44% and triacylglycerol (TG) 94%, neither changed in the rats. In hyperleptinemic young rats, adipocyte expression of preadipocyte factor 1 increased dramatically and leptin mRNA virtually disappeared; there was increased expression of acyl CoA oxidase, carnitine palmitoyl transferase 1, and their transcription factor peroxisome proliferator-activated receptor α, accounting for the reduction in body fat. These hyperleptinemia-induced changes were profoundly reduced in the old rats. On a high-fat diet, old rats consumed 28% more calories than the young and gained 1.5× as much fat, despite greater endogenous hyperleptinemia. Expression of a candidate leptin resistance factor, suppressor of cytokine signaling 3 (SOCS-3), was compared in the hypothalamus and white adipocytes of young and old rats before and after induction of hyperleptinemia; hypothalamic SOCS-3 mRNA was ∼3× higher in old rats before, whereas it was 3× higher in WAT after, hyperleptinemia. We conclude that the anorexic and antilipopenic actions of leptin decline with age, possibly through increased SOCS-3 expression, and that this could account for the associated abnormalities in lipid metabolism of the elderly.
AB - Leptin resistance has been implicated in the pathogenesis of obesity-related complications involving abnormalities of lipid metabolism that resemble those of old age. To determine whether development of leptin resistance in advancing age might account for such abnormalities, we compared the effects of hyperleptinemia (>40 ng/ml) induced in 2-month-old and 18-month-old lean wild-type (+/+) Zucker diabetic fatty rats by adenovirus gene transfer. The decline in food intake, body weight, and body fat in old rats was only 25%, 50%, and 16%, respectively, of the young rats. Whereas in young rats plasma free fatty acids fell 44% and triacylglycerol (TG) 94%, neither changed in the rats. In hyperleptinemic young rats, adipocyte expression of preadipocyte factor 1 increased dramatically and leptin mRNA virtually disappeared; there was increased expression of acyl CoA oxidase, carnitine palmitoyl transferase 1, and their transcription factor peroxisome proliferator-activated receptor α, accounting for the reduction in body fat. These hyperleptinemia-induced changes were profoundly reduced in the old rats. On a high-fat diet, old rats consumed 28% more calories than the young and gained 1.5× as much fat, despite greater endogenous hyperleptinemia. Expression of a candidate leptin resistance factor, suppressor of cytokine signaling 3 (SOCS-3), was compared in the hypothalamus and white adipocytes of young and old rats before and after induction of hyperleptinemia; hypothalamic SOCS-3 mRNA was ∼3× higher in old rats before, whereas it was 3× higher in WAT after, hyperleptinemia. We conclude that the anorexic and antilipopenic actions of leptin decline with age, possibly through increased SOCS-3 expression, and that this could account for the associated abnormalities in lipid metabolism of the elderly.
KW - Fatty acids
KW - High-fat diet
KW - Hyperleptinemia
KW - Hypothalamus
KW - Lipotoxicity
KW - SOCS-3
UR - http://www.scopus.com/inward/record.url?scp=0035162054&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035162054&partnerID=8YFLogxK
U2 - 10.1096/fj.00-0310com
DO - 10.1096/fj.00-0310com
M3 - Article
C2 - 11149898
AN - SCOPUS:0035162054
SN - 0892-6638
VL - 15
SP - 108
EP - 114
JO - FASEB Journal
JF - FASEB Journal
IS - 1
ER -