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Independence of triacylglycerol‐containing compartments in cultured fibroblasts from Wolman disease and multisystemic lipid storage myopathy
Author(s) -
Salvayre Robert,
Nègre Anne,
Radom Jean,
Douste-Blazy Louis
Publication year - 1989
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(89)80679-9
Subject(s) - catabolism , myopathy , lipid droplet , cytoplasm , biochemistry , vacuole , compartment (ship) , enzyme , cellular compartment , lipid metabolism , chemistry , biology , microbiology and biotechnology , cell , genetics , oceanography , geology
The functional relationship between the two subcellular compartments involved in catabolism of triglycerides, i.e. lysosomes and lipid‐containing cytoplasmic vacuoles, has been investigated using cultured fibroblasts from patients affected with two different genetic lipid (triacylglycerol) storage disorders: Wolman disease and multisystemic lipid storage myopathy. As shown by metabolic studies in intact cultured cells, lysosomal degradation of exogenous labelled triacylglycerols (incorporated into lipoproteins and internalized via the apo B/E receptor pathway) was blocked in Wolman cells, whereas catabolism of endogenously biosynthesized triacylglycerols was in the normal range. In contrast, in fibroblasts from multisystemic lipid storage myopathy, the degradation of endogenous triacylglycerols was blocked, whereas that of exogenous triacylglycerols (i.e. from lipoproteins) was normal. This comparative study demonstrates that the lysosomal and cytoplasmic compartments are functionally independent. Enzymatic studies allow one to discriminate clearly between 3 lipases and 2 carboxylesterases the role of which is discussed.