Scientific article

Nicotinamide adenine dinucleotide phosphate reduced oxidase 5 (Nox5) regulation by angiotensin II and endothelin-1 is mediated via calcium/calmodulin-dependent, rac-1-independent pathways in human endothelial cells

Published inCirculation research, vol. 106, no. 8, p. 1363-1373
Publication date2010

RATIONALE: Although Nox5 (Nox2 homolog) has been identified in the vasculature, its regulation and functional significance remain unclear. OBJECTIVES: We sought to test whether vasoactive agents regulate Nox5 through Ca(2+)/calmodulin-dependent processes and whether Ca(2+)-sensitive Nox5, associated with Rac-1, generates superoxide (O(2)(*-)) and activates growth and inflammatory responses via mitogen-activated protein kinases in human endothelial cells (ECs). METHODS AND RESULTS: Cultured ECs, exposed to angiotensin II (Ang II) and endothelin (ET)-1 in the absence and presence of diltiazem (Ca(2+) channel blocker), calmidazolium (calmodulin inhibitor), and EHT1864 (Rac-1 inhibitor), were studied. Nox5 was downregulated with small interfering RNA. Ang II and ET-1 increased Nox5 expression (mRNA and protein). Effects were inhibited by actinomycin D and cycloheximide and blunted by diltiazem, calmidazolium and low extracellular Ca(2+) ([Ca(2+)](e)). Ang II and ET-1 activated NADPH oxidase, an effect blocked by low [Ca(2+)](e), but not by EHT1864. Nox5 knockdown abrogated agonist-stimulated O(2)(*-) production and inhibited phosphorylation of extracellular signal-regulated kinase (ERK)1/2, but not p38 MAPK (mitogen-activated protein kinase) or SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase). Nox5 small interfering RNA blunted Ang II-induced, but not ET-1-induced, upregulation of proliferating-cell nuclear antigen and vascular cell adhesion molecule-1, important in growth and inflammation. CONCLUSIONS: Human ECs possess functionally active Nox5, regulated by Ang II and ET-1 through Ca(2+)/calmodulin-dependent, Rac-1-independent mechanisms. Nox5 activation by Ang II and ET-1 induces ROS generation and ERK1/2 phosphorylation. Nox5 is involved in ERK1/2-regulated growth and inflammatory signaling by Ang II but not by ET-1. We elucidate novel mechanisms whereby vasoactive peptides regulate Nox5 in human ECs and demonstrate differential Nox5-mediated functional responses by Ang II and ET-1. Such phenomena link Ca(2+)/calmodulin to Nox5 signaling, potentially important in the regulation of endothelial function by Ang II and ET-1.

  • Angiotensin II/ metabolism
  • Calcium/ metabolism
  • Calcium Channel Blockers/pharmacology
  • Calmodulin/antagonists & inhibitors/ metabolism
  • Cells, Cultured
  • Diltiazem/pharmacology
  • Endothelial Cells/drug effects/ enzymology
  • Endothelin-1/ metabolism
  • Enzyme Activation
  • Enzyme Inhibitors/pharmacology
  • Gene Expression Regulation, Enzymologic
  • Humans
  • Imidazoles/pharmacology
  • Inflammation/enzymology
  • JNK Mitogen-Activated Protein Kinases/metabolism
  • Membrane Proteins/genetics/ metabolism
  • Mitogen-Activated Protein Kinase 1/metabolism
  • Mitogen-Activated Protein Kinase 3/metabolism
  • NADPH Oxidase/genetics/ metabolism
  • Phosphorylation
  • Proliferating Cell Nuclear Antigen/metabolism
  • Pyrones/pharmacology
  • Quinolines/pharmacology
  • RNA Interference
  • RNA, Messenger/metabolism
  • Signal Transduction/drug effects
  • Superoxides/metabolism
  • Time Factors
  • Vascular Cell Adhesion Molecule-1/metabolism
  • p38 Mitogen-Activated Protein Kinases/metabolism
  • rac1 GTP-Binding Protein/antagonists & inhibitors/ metabolism
Affiliation Not a UNIGE publication
Citation (ISO format)
MONTEZANO, A. C. et al. Nicotinamide adenine dinucleotide phosphate reduced oxidase 5 (Nox5) regulation by angiotensin II and endothelin-1 is mediated via calcium/calmodulin-dependent, rac-1-independent pathways in human endothelial cells. In: Circulation research, 2010, vol. 106, n° 8, p. 1363–1373. doi: 10.1161/CIRCRESAHA.109.216036
Updates (1)
ISSN of the journal0009-7330

Technical informations

Creation08/27/2010 1:35:38 PM
First validation08/27/2010 1:35:38 PM
Update time03/14/2023 4:04:36 PM
Status update03/14/2023 4:04:35 PM
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