Steroidogenic enzyme gene expression in the human brain

mRNA, protein and activity for the enzymes required for the synthesis of adrenal corticosteroids have been demonstrated in rat brains by several laboratories. In this study real-time RT-PCR was used to determine whether mRNA for these enzymes are expressed in the human amygdala, caudate nucleus, cerebellum, corpus callosum, hippocampus, spinal cord, and thalamus. Published sequences for the human adrenal enzymes were used to construct primers. Results: mRNAs encoding cholesterol side-chain cleavage enzyme (CYP11A gene), 17beta-hydroxylase (CYP17), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 21-hydroxylase (CYP21), 11beta-hydroxysteroid dehydrogenase (11beta-HSD2) and glucocorticoid and mineralocorticoid receptors were detectable in all anatomical regions evaluated. The wwbeta-hydroxylase mRNA was detected in all except cerebellum and hippocampus. The aldosterone synthase mRNA was not found in amygdala, cerebellum or hippocampus. Levels of transcripts were 10(-1)-10(-7)-fold lower than those in the adrenal, with corpus callosum and spinal cord having the highest concentrations. Enzyme activity or relevance is yet unknown. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.