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Correction of sphingomyelinase deficiency in Niemann-Pick type C fibroblasts by removal of lipoprotein fraction from culture media

Authors :
Thomas, G. H.
Tuck-Muller, C. M.
Miller, C. S.
Reynolds, L. W.
Source :
Journal of Inherited Metabolic Disease; June 1989, Vol. 12 Issue: 2 p139-151, 13p
Publication Year :
1989

Abstract

The average sphingomyelinase activity of fibroblasts obtained from 12 Niemann-Pick type C patients was 37.9% of that of normal fibroblasts (27.2versus72nmol(mg protein)-1h-1) when the cells were cultured in minimum essential medium containing 13% fetal bovine serum. Following replacement of the above medium with medium in which the lipoprotein fraction had been removed from the fetal bovine serum, the sphingomyelinase activity rose over a 7-day period from about 1/3 of normal to normal or above. Upon reintroduction of medium containing 10% fetal bovine serum which had not been extracted, the sphingomyelinase activity of the Niemann-Pick type C cells again fell within 48h to 30% of the normal controls. In contrast, cell lines from patients with either Niemann-Pick Type A or B were not influenced by the presence or the absence of lipoprotein, i.e. lacked sphingomyelinase activity under all culture conditions examined. Histochemical staining with filipin showed an inverse relationship between the sphingomyelinase activity and intracellular, free, unesterified, cholesterol level. Moreover, immunochemical staining with an antibody against a lysosomal membrane protein provided direct evidence that the accumulation of unesterified cholesterol in cells cultured in regular (non-extracted) medium occurred within lysosomes and/or related organelles.

Details

Language :
English
ISSN :
01418955 and 15732665
Volume :
12
Issue :
2
Database :
Supplemental Index
Journal :
Journal of Inherited Metabolic Disease
Publication Type :
Periodical
Accession number :
ejs47605438
Full Text :
https://doi.org/10.1007/BF01800716