Up-regulation of hepatic lipolysis stimulated lipoprotein receptor by leptin: a potential lever for controlling lipid clearance during the postprandial phase.
FASEB J
; 24(11): 4218-28, 2010 Nov.
Article
em En
| MEDLINE
| ID: mdl-20647547
ABSTRACT
As a hepatic receptor for triglyceride-rich lipoproteins, the lipolysis-stimulated lipoprotein receptor (LSR) may be involved in the dynamics of lipid distribution between the liver and peripheral tissues. Here, we explore the potential role of leptin in regulating LSR. At physiological concentrations (1-10 ng/ml), leptin increased LSR protein and mRNA levels in Hepa1-6 cells through an ERK1/2-dependent and α-amanitin-sensitive pathway. In vivo, leptin treatment of C57BL6/Rj mice (1 µg 2×/d, 8 d) led to a significant increase in hepatic LSR mRNA and protein, decreased liver triglycerides and increased VLDL secretion as compared to controls. LSR(+/-) mice with elevated postprandial lipemia placed on a high-fat (60% kcal) diet exhibited accelerated weight gain and increased fat mass as compared to controls. While plasma leptin levels were increased 3-fold, hepatic leptin receptor protein levels and phosphorylation of ERK1/2 were significantly reduced. Therefore, leptin is an important regulator of LSR protein levels providing the means for the control of hepatic uptake of lipids during the postprandial phase. However, this may no longer be functional in LSR(+/-) mice placed under a chronic dietary fat load, suggesting that this animal model could be useful for the study of molecular mechanisms involved in peripheral leptin resistance.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Regulação para Cima
/
Receptores de Lipoproteínas
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Período Pós-Prandial
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Leptina
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Metabolismo dos Lipídeos
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Lipólise
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Fígado
Limite:
Animals
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
França