Endothelial lipase provides an alternative pathway for FFA uptake in lipoprotein lipase–deficient mouse adipose tissue
AUTOR(ES)
Kratky, Dagmar
FONTE
American Society for Clinical Investigation
RESUMO
Lipoprotein lipase (LPL) is thought to be the only enzyme responsible for the catabolism of triglycerides (TGs) associated with TG-rich lipoproteins in adipose tissue (AT). However, LPL deficiency in humans and induced mutant mice is not associated with decreased fat mass. We investigated whether endothelial lipase (EL), a recently discovered phospholipase, might represent an alternative mechanism for the uptake of phospholipid-derived fatty acids in murine lipoprotein-deficient AT. When LPL was expressed in AT and isolated murine adipocytes, EL mRNA was not detectable. In contrast, mouse AT and isolated adipocytes that lacked LPL expressed large amounts of EL mRNA. The cellular phospholipase activity in LPL-deficient fat pads was increased 4-fold compared with control fat pads and could be inhibited to control levels by a specific EL antibody. Fatty acids produced by EL activity were absorbed by adipocytes and incorporated into the TG moiety of AT. Our results suggest that EL activity in AT and other peripheral tissues might contribute to the tissue uptake of free fatty acids, which could have important implications for the metabolism of plasma lipoproteins.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=539186Documentos Relacionados
- Metabolism of apolipoproteins B-48 and B-100 of triglyceride-rich lipoproteins in normal and lipoprotein lipase-deficient humans.
- Lipoprotein lipase controls fatty acid entry into adipose tissue, but fat mass is preserved by endogenous synthesis in mice deficient in adipose tissue lipoprotein lipase
- Characterization of lipase-deficient mutants of Acinetobacter calcoaceticus BD413: identification of a periplasmic lipase chaperone essential for the production of extracellular lipase.
- Hepatic lipase gene therapy in hepatic lipase-deficient mice. Adenovirus-mediated replacement of a lipolytic enzyme to the vascular endothelium.
- Extracellular degradation of lipoprotein lipase in rat adipose tissue