Steroid 21-hydroxylase expression and activity in human lymphocytes.
Steroid 21-hydroxylase encoded by CYP21 is expressed in adrenal cortex. Mutations in CYP21 cause potentially lethal congenital adrenal hyperplasia (CAH). Earlier observations suggested alternative sources of 21-hydroxylase activity, although its genetic source remains unclear. We found a novel source of CYP21 expression in normal human cultured B lymphocytes. The quantity of 21-hydroxylase transcript was reduced in B cell lines of CAH subjects compared with that in normal B-lymphoblastoid cells. No CYP21 transcript was detected in lymphocytes from a CAH patient with homozygous CYP21 deletion. Cultured lymphoid cells, including those carrying homozygous CYP21 deletion, and peripheral blood leukocytes converted both 17-hydroxyprogesterone to 11-deoxycortisol and progesterone to deoxycorticosterone. We conclude that lymphocytes express CYP21, but also possess a 21-hydroxylase distinct from CYP21. Activity of this isozyme may partially compensate for severe adrenal 21-hydroxylase deficiency.
Zhou
Z
Z
Department of Pediatrics, North Shore University Hospital, New York University School of Medicine, Manhasset 11030, USA.
Agarwal
V R
VR
Dixit
N
N
White
P
P
Speiser
P W
PW
D000312:Adrenal Hyperplasia, Congenital / Q000201:enzymology*; D001402:B-Lymphocytes / Q000201:enzymology*; D002460:Cell Line; D017931:DNA Primers; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic; D005819:Genetic Markers; D006801:Humans; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013255:Steroid 21-Hydroxylase / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D005819:Genetic Markers; D013255:Steroid 21-Hydroxylase