Myocyte enhancer factor 2B is involved in the inducible expression of NOX1/NADPH oxidase, a vascular superoxide-producing enzyme

FEBS J. 2007 Oct;274(19):5128-36. doi: 10.1111/j.1742-4658.2007.06034.x. Epub 2007 Sep 5.

Abstract

NADPH oxidase is a major source of the superoxide produced in cardiovascular tissues. Expression of NOX1, a catalytic subunit of NADPH oxidase, is induced by various vasoactive factors, including angiotensin II, prostaglandin (PG) F(2alpha) and platelet-derived growth factor (PDGF). To clarify the molecular basis of this transcriptional activation, we delineated the promoter region of the NOX1 gene. RT-PCR and 5'-rapid amplification of cDNA ends-based analyses revealed a novel 5'-terminal exon of the rat NOX1 gene located approximately 28 kb upstream of the exon containing the start codon. Both PGF(2alpha) and PDGF enhanced the transcriptional activity of the - 3.6 kb 5'-flanking region of the NOX1 gene in A7r5 cells, a rat vascular smooth muscle cell line. A PGF(2alpha)-response element was located between -146 and -125 in the 5'-flanking region containing a consensus binding site for myocyte enhancer factor 2 (MEF2), to which binding of MEF2 was augmented by PGF(2alpha). Gene silencing of MEF2B by RNA interference significantly suppressed the expression of NOX1, while silencing of activating transcription factor (ATF)-1, previously implicated in up-regulation of NOX1, abolished the PGF(2alpha)- or PDGF-induced expression of MEF2B. These results indicate that superoxide production in vascular smooth muscle cells is regulated by the ATF-1-MEF2B cascade by induction of the expression of the NOX1 gene.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Blood Vessels / enzymology*
  • Cell Line
  • DNA Primers
  • DNA, Complementary
  • Dinoprost / physiology
  • Electrophoretic Mobility Shift Assay
  • Enzyme Induction
  • Gene Silencing
  • MEF2 Transcription Factors
  • Molecular Sequence Data
  • Myogenic Regulatory Factors / physiology*
  • NADH, NADPH Oxidoreductases / biosynthesis*
  • NADH, NADPH Oxidoreductases / genetics
  • NADH, NADPH Oxidoreductases / metabolism
  • NADPH Oxidase 1
  • Platelet-Derived Growth Factor / physiology
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • Rats
  • Superoxides / metabolism*
  • Transcriptional Activation / physiology

Substances

  • DNA Primers
  • DNA, Complementary
  • MEF2 Transcription Factors
  • Myogenic Regulatory Factors
  • Platelet-Derived Growth Factor
  • RNA, Messenger
  • Superoxides
  • Dinoprost
  • NADH, NADPH Oxidoreductases
  • NADPH Oxidase 1
  • NOX1 protein, rat

Associated data

  • GENBANK/AB258525