出版社：American Society for Biochemistry and Molecular Biology
摘要：Seven human disorders of postsqualene cholesterol biosynthesishave been described. One of these, congenital hemidysplasiawith ichthyosiform nevus and limb defects (CHILD) syndrome,results from mutations in the X-linked gene NADH sterol dehydrogenase-like(NSDHL) encoding a sterol dehydrogenase. A series of mutantalleles of the murine Nsdhl gene are carried by bare patches(Bpa) mice, with Bpa1H representing a null allele. HeterozygousBpa1H females display skin and skeletal abnormalities in a distributionreflecting random X inactivation, whereas hemizygous male embryosdie before embryonic day 10.5. To investigate the molecularbasis of defects associated with perturbations in cholesterolbiosynthesis, microarray analysis was performed comparing geneexpression in embryonic fibroblasts expressing the Bpa1H alleleversus wild-type (wt) cells. Labeled cDNAs from cells grownin normal serum or lipid-depleted serum (LDS) were hybridizedto microarrays containing 22,000 mouse genes. Among 44 genesthat showed higher expression in the Bpa1H versus wt cells grownin LDS, 11 function in cholesterol biosynthesis, 7 are involvedin fatty acid synthesis, 3 (Srebp2, Insig1, and Orf11) encodesterol-regulatory proteins, and 2 (Ldlr and StarD4) are lipidtransporters.
Of the 21 remaining genes, 16 are known genes, some of whichhave been implicated previously in cholesterol homeostasis orlipid-mediated signaling, and 5 are uncharacterized cDNA clones.Abbreviations:Bpa, bare patches; CHILD, congenital hemidysplasia with ichthyosiform nevus and limb defects; 7DHC, 7-dehydrocholesterol; E13.5, embryonic day 13.5; ER, endoplasmic reticulum; FACS, fluorescence-activated cell sorting; GFP, green fluorescent protein; HMGR, 3-hydroxy-3-methylglutaryl-CoA reductase; LDS, lipid-depleted serum; MEF, mouse embryonic fibroblast; NSDHL, NADH sterol dehydrogenase-like; SCAP, sterol-regulatory element binding protein cleavage-activating protein; SREBP, sterol-regulatory element binding protein; wt, wild type
Supplementary key words cholesterol biosynthesis • congenital hemidysplasia with ichthyosiform nevus and limb defects syndrome • microarray • bare patches • sterol • development
