Measurement of 3 beta-hydroxysteroid delta 7-reductase activity in cultured skin fibroblasts utilizing ergosterol as a substrate: a new method for the diagnosis of the Smith-Lemli-Opitz syndrome

Autor: M Honda, G S Tint, A Honda, A K Batta, T S Chen, S Shefer, G Salen
Jazyk: angličtina
Rok vydání: 1996
Předmět:
Zdroj: Journal of Lipid Research, Vol 37, Iss 11, Pp 2433-2438 (1996)
Druh dokumentu: article
ISSN: 0022-2275
DOI: 10.1016/S0022-2275(20)37491-5
Popis: A new sensitive and specific method for the evaluation of 3 beta-hydroxysteroid delta 7-reductase activity, the defective enzyme in the Smith-Lemli-Opitz (SLO) syndrome, is described. The assay is based on the use of gas chromatography-mass spectrometry with selected-ion monitoring to measure the mass of brassicasterol (ergosta-5,22-dien-3 beta-ol) produced by the incubation of ergosterol (ergosta-5,7,22-trien-3 beta-ol) with cultured human skin fibroblasts. Although the conversion of ergosterol to brassicasterol was slower than the transformation of [3H]7-dehydrocholesterol to [3H] cholesterol, cells from control subjects produced brassicasterol efficiently. In contrast, cells form SLO patients produced very little brassicasterol (P < 0.0001, patients vs. parents or vs. controls). These results indicate that the reduction of ergosterol can be used as an assay for 3 beta-hydroxysteroid delta 7-reductase in human skin fibroblasts, which avoids the many problems caused by the instability and lack of availability of radiolabeled 7-dehydrocholesterol. The present method made it possible to diagnose the SLO syndrome with high sensitivity and reliability using a commercially available compound.
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