Endoplasmic reticulum-localized hepatic lipase decreases triacylglycerol storage and VLDL secretion

Hepatic triacylglycerol levels are governed through synthesis, degradation and export of this lipid. Here we demonstrate that enforced expression of hepatic lipase in the endoplasmic reticulum in McArdle RH7777 hepatocytes resulted in a significant decrease in the incorporation of fatty acids into cellular triacylglycerol and cholesteryl ester accompanied by attenuation of secretion of apolipoprotein B-containing lipoproteins. Hepatic lipase-mediated depletion of intracellular lipid storage increased the expression of peroxisome proliferator-activated receptor α and its target genes and augmented oxidation of fatty acids. These data show that 1) hepatic lipase is active in the endoplasmic reticulum and 2) intracellular hepatic lipase modulates cellular lipid metabolism and lipoprotein secretion.Fil: Erickson, Bruce. University of Alberta; CanadáFil: Selvan, Senthamil Paramadayalan. University of Alberta; CanadáFil: Ko, Kerry W. S.. University of Alberta; CanadáFil: Kelly, Karen. University of Alberta; CanadáFil: Quiroga, Ariel Dario. University of Alberta; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Fisiología Experimental (i); ArgentinaFil: Li, Lena. University of Alberta; CanadáFil: Nelson, Randy. University of Alberta; CanadáFil: King Jones, Kirst. University of Alberta; CanadáFil: Jacobs, René L.. University of Alberta; CanadáFil: Lehner, Richard. University of Alberta; Canad