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NOX2 and NOX4 mediate proliferative response in endothelial cells
Andreas Petry1, Talija Djordjevic, Michael Weitnauer
1Experimental Pediatric Cardiology, Department of Pediatric Cardiology and Congenital Heart Diseases, German Heart Center Munich at the Technical University Munich, Munich, Germany.
Antioxidants & Redox Signaling
|September 22, 2006
Summary
Endothelial cells generate reactive oxygen species (ROS) via NADPH oxidase (NOX) enzymes. Both NOX2 and NOX4 equally contribute to endothelial ROS production and cell proliferation, while NOX1 plays a minor role.
Area of Science:
- Vascular Biology
- Cellular Physiology
- Biochemistry
Background:
- Reactive oxygen species (ROS) are implicated in cardiovascular diseases.
- NADPH oxidases (NOX) are key sources of vascular ROS.
- The roles of different NOX homologues in endothelial cells are not fully understood.
Purpose of the Study:
- To compare the roles of NOX1, NOX2, and NOX4 in endothelial ROS production and proliferation.
- To investigate the co-localization and interactions of NOX homologues in endothelial cells.
Main Methods:
- Quantitative analysis of NOX1, NOX2, and NOX4 expression in endothelial cells.
- Bimolecular fluorescent complementation to study protein interactions.
- Assessment of ROS production and cell proliferation under basal conditions.
Main Results:
- Endothelial cells express NOX2 and NOX4 abundantly, with less prominent NOX1 expression.
- NOX2, NOX4, and NOX1 were found in a perinuclear compartment, with NOX2 and NOX4 co-localizing with the ER.
- NOX2 and NOX4 equally contributed to endothelial ROS generation and proliferation, whereas NOX1 did not significantly affect ROS levels.
Conclusions:
- Endothelial cells co-express NOX1, NOX2, and NOX4.
- NOX2 and NOX4 are the primary contributors to basal endothelial ROS production and proliferation.
- A complex interplay among NOX homologues regulates endothelial function.
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