Cytoplasmic triacylglycerols and cholesteryl esters are degraded in two separate catabolic pools in cultured human fibroblasts
- 16 August 1993
- journal article
- Published by Wiley in FEBS Letters
- Vol. 328 (3) , 230-234
- https://doi.org/10.1016/0014-5793(93)80933-l
Abstract
The sources and the catabolic pathways of cytoplasmic pools of triacylglycerols and cholesteryl esters have been comparatively investigated in cultured fibroblasts from normal subjects and from patients affected with neutral lipid storage disease (NLSD) and Wolman disease (WD). (i) Endogenously biosynthesized triacylglycerols and cholesteryl esters were degraded extra-lysosomaily since they were catabolized at similar rates in normal and in WD fibroblasts. In NLSD fibroblasts, the degradation of endogenous triacylglycerols was severely deficient, whereas that of endogenous cholesteryl esters was in the normal range, (ii) Reconstituted high density lipoproteins (HDL) containing radiolabelled [3H]triolein and cholesteryl [14C]oleate were taken up by cultured fibroblasts and rapidly degraded in a non-lysosomal compartment. In NLSD fibroblasts the degradation of HDL-[3H]triolein was blocked whereas that of HDL-[14C]cholesteryl oleate was in the normal range. These data suggest that: (i) the cytoplasmic pools of triacylglycerols and cholesteryl esters originate from HDL uptake and from endogenous biosynthesis as well; (ii) cytoplasmic (non-lysosomal) triacylglycerols and cholesteryl esters are degraded by two separate catabolic pathways.Keywords
This publication has 47 references indexed in Scilit:
- Cholesterol ester hydrolysis and hormone-sensitive lipase in lactating rat mammary tissueBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1991
- Cholesterol esters selectively taken up from high-density lipoproteins are hydrolyzed extralysosomallyBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1990
- Receptor-mediated uptake and ‘retroendocytosis’ of high-density lipoproteins by cholesterol-loaded human monocyte-derived macrophages: possible role in enhancing reverse cholesterol transportBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1989
- Contribution of cytoplasmic storage triacylglycerol to VLDL-triacylglycerol in isolated rat hepatocytesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1989
- Immunological evidence for the presence of hormone-sensitive lipase in rat tissues other than adipose tissueBiochemical and Biophysical Research Communications, 1987
- The uptake of the apoprotein and cholesteryl ester of high-density lipoproteins by the perfused rat liverBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1987
- Bile acid synthesis from HDL cholesterol and cholesterol ester by cultured chick embryo hepatocytesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1986
- Morphological evidence of lysosomal uptake of high-density lipoproteins by rat adrenocortical cells in vitroMolecular and Cellular Endocrinology, 1986
- Lipolysis of hepatic triacylglycerol storesFEBS Letters, 1982