Gender differences in the expression and cellular localization of lipin 1 in the hearts of fructose-fed rats.
To give new insight to alterations of cardiac lipid metabolism accompanied by a fructose-rich diet (FRD), rats of both sexes were exposed to 10 % fructose in drinking water during 9 weeks. The protein level and subcellular localization of the main regulators of cardiac lipid metabolism, such as lipin 1, peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α), carnitine palmitoyltransferase I (CPTI), and CD36 were studied. Caloric intake in fructose-fed rats (FFR) of both sexes was increased. Circulating triacylglyceroles (TAG) and non-esterified fatty acids were increased in male FFR, while females increased visceral adiposity and blood TAG. Total expression of lipin 1 in cardiac cell lysate and its cytosolic and microsomal level were increased in the hearts of male FFR. PPARα and PGC-1α content were decreased in the nuclear extract. In addition, cardiac deposition of TAG in male FFR was elevated, as well as inhibitory phosphorylation of insulin receptor substrate 1 (IRS-1). In contrast, in female FFR, lipin 1 level was increased in nuclear extract only, while overall CPTI expression and phosphorylation of IRS-1 at serine 307 were decreased. The results of our study suggest that fructose diet causes gender-dependent alterations in cardiac lipid metabolism. Potentially detrimental effects of FRD seem to be limited to male rats. Most of the observed changes might be a consequence of elevated expression and altered localization of lipin 1. Increased inhibitory phosphorylation of IRS-1 is possible link between cardiac lipid metabolism and insulin resistance in FFR.
Laboratory for Molecular Biology and Endocrinology, Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001, Belgrade, Serbia.
Snježana
S
Romić
Snežana
S
Tepavčević
Zorica
Z
Žakula
Tijana
T
Milosavljević
Milan
M
Kostić
Marijana
M
Petković
Goran
G
Korićanac
D000818:Animals; D004032:Diet; D005260:Female; D005632:Fructose / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D009206:Myocardium / Q000166:cytology*; D009687:Nuclear Proteins / Q000032:analysis* / Q000096:biosynthesis*; D051381:Rats; D012727:Sex Characteristics
C530902:Lpin1 protein, rat; D009687:Nuclear Proteins; D005632:Fructose