Regulation of aldosterone and cortisol production by the transcriptional repressor neuron restrictive silencer factor

Endocrinology. 2009 Jul;150(7):3110-7. doi: 10.1210/en.2008-1624. Epub 2009 Apr 2.

Abstract

Aldosterone synthase (CYP11B2) and 11 beta-hydroxylase (CYP11B1) regulate aldosterone and cortisol production, respectively. The expression of these enzymes is promoted by calcium influx through Cav3.2, a T-type calcium channel. Neuron-restrictive silencer factor (NRSF) binds to neuron-restrictive silencer element (NRSE) to suppress the transcription of NRSE-containing genes. We found a NRSE-like sequence in human CYP11B2 and CYP11B1 genes as well as the CACNA1H gene of many mammalian species. The CACNA1H gene encodes the alpha-subunit of Cav3.2. Here we investigated how NRSF/NRSE regulates aldosterone and cortisol synthesis. Inhibition of endogenous NRSF by an adenovirus-expressing dominant-negative NRSF (AD/dnNRSF) increased human CYP11B2 and CYP11B1 mRNA expression, leading to aldosterone and cortisol secretion in human adrenocortical (H295R) cells. In reporter gene experiments, NRSE suppressed luciferase reporters driven by CYP11B2 and CYP11B1 promoters and dnNRSF enhanced them. Moreover, cotransfection of dnNRSF increased luciferase activity of reporter genes after deletion or mutation of NRSE, suggesting that NRSF/NRSE regulates transcription of CYP11B2 and CYP11B1 genes indirectly. AD/dnNRSF augmented mRNA expression of rat CYP11B2 and CYP11B1 genes, neither of which contains a NRSE-like sequence in rat adrenal cells. AD/dnNRSE also significantly increased CACNA1H mRNA in H295R and rat adrenal cells. Efonidipine, a T/L-type calcium channel blocker, significantly suppressed dnNRSF-mediated up-regulation of CYP11B2 and CYP11B1 expression. Moreover, NRSF/NRSE is also involved in angiotensin II- and K(+)-stimulated augmentation of CYP11B2 and CYP11B1 gene transcription. In conclusion, NRSF/NRSE controls aldosterone and cortisol synthesis by regulating CYP11B2 and CYP11B1 gene transcription mainly through NRSF/NRSE-mediated enhancement of the CACNA1H gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldosterone / biosynthesis*
  • Angiotensin II / physiology
  • Animals
  • Calcium Channels, T-Type / genetics
  • Cell Line
  • Cytochrome P-450 CYP11B2 / genetics
  • Cytochrome P-450 CYP11B2 / metabolism
  • Humans
  • Hydrocortisone / biosynthesis*
  • Potassium / physiology
  • Rats
  • Repressor Proteins / physiology*
  • Steroid 11-beta-Hydroxylase / genetics

Substances

  • CACNA1H protein, human
  • Calcium Channels, T-Type
  • RE1-silencing transcription factor
  • Repressor Proteins
  • Angiotensin II
  • Aldosterone
  • Cytochrome P-450 CYP11B2
  • Steroid 11-beta-Hydroxylase
  • Potassium
  • Hydrocortisone