Related Experiment Video
Updated: Apr 11, 2026
Ratiometric Biosensors that Measure Mitochondrial Redox State and ATP in Living Yeast Cells
Published on: July 22, 2013
NOX4 NADPH Oxidase-Dependent Mitochondrial Oxidative Stress in Aging-Associated Cardiovascular Disease
Aleksandr E Vendrov1, Kimberly C Vendrov2, Alberto Smith3
11 Department of Medicine, McAllister Heart Institute, University of North Carolina , Chapel Hill, North Carolina.
Aims:
Increased oxidative stress and vascular inflammation are implicated in increased cardiovascular disease (CVD) incidence with age. We and others demonstrated that NOX1/2 NADPH oxidase inhibition, by genetic deletion of p47phox, in Apoe(-/-) mice decreases vascular reactive oxygen species (ROS) generation and atherosclerosis in young age. The present study examined whether NOX1/2 NADPH oxidases are also pivotal to aging-associated CVD.
Results:
Both aged (16 months) Apoe(-/-) and Apoe(-/-)/p47phox(-/-) mice had increased atherosclerotic lesion area, aortic stiffness, and systolic dysfunction compared with young (4 months) cohorts. Cellular and mitochondrial ROS (mtROS) levels were significantly higher in aortic wall and vascular smooth muscle cells (VSMCs) from aged wild-type and p47phox(-/-) mice. VSMCs from aged mice had increased mitochondrial protein oxidation and dysfunction and increased vascular cell adhesion molecule 1 expression, which was abrogated with (2-(2,2,6,6-Tetramethylpiperidin-1-oxyl-4-ylamino)-2-oxoethyl)triphenylphosphonium chloride (MitoTEMPO) treatment. NOX4 expression was increased in the vasculature and mitochondria of aged mice and its suppression with shRNA in VSMCs from aged mice decreased mtROS levels and improved function. Increased mtROS levels were associated with enhanced mitochondrial NOX4 expression in aortic VSMCs from aged subjects, and NOX4 expression levels in arterial wall correlated with age and atherosclerotic severity. Aged Apoe(-/-) mice treated with MitoTEMPO and 2-(2-chlorophenyl)-4-methyl-5-(pyridin-2-ylmethyl)-1H-pyrazolo[4,3-c]pyridine-3,6(2H,5H)-dione had decreased vascular ROS levels and atherosclerosis and preserved vascular and cardiac function.
Innovation And Conclusion:
These data suggest that NOX4, but not NOX1/2, and mitochondrial oxidative stress are mediators of CVD in aging under hyperlipidemic conditions. Regulating NOX4 activity/expression and using mitochondrial antioxidants are potential approaches to reducing aging-associated CVD.
Insights
Mitochondrial oxidative stress and NOX4 contribute to age-related cardiovascular disease (CVD) in hyperlipidemic mice. Targeting NOX4 and using mitochondrial antioxidants may reduce aging-associated CVD.
Area of Science:
- Cardiovascular Science
- Oxidative Stress Research
- Aging Biology
Background:
- Increased oxidative stress and vascular inflammation contribute to age-related cardiovascular disease (CVD).
- Previous studies showed NOX1/2 NADPH oxidase inhibition reduces atherosclerosis in young Apoe(-/-) mice.
- The role of NOX1/2 in aging-associated CVD remained unclear.
Purpose of the Study:
- To investigate the role of NOX1/2 NADPH oxidases in aging-associated CVD.
- To determine the contribution of mitochondrial reactive oxygen species (mtROS) to vascular dysfunction in aged mice.
- To explore NOX4 as a potential mediator of aging-related vascular pathology.
Main Methods:
- Comparison of young (4 months) and aged (16 months) Apoe(-/-) and Apoe(-/-)/p47phox(-/-) mice.
- Measurement of atherosclerotic lesion area, aortic stiffness, and cardiac function.
- Assessment of cellular and mitochondrial ROS (mtROS) levels in aortic walls and vascular smooth muscle cells (VSMCs).
- Evaluation of mitochondrial protein oxidation, VSMC function, and vascular cell adhesion molecule 1 expression.
- Pharmacological inhibition of ROS with MitoTEMPO and NOX inhibition with a specific compound.
- Genetic suppression of NOX4 using shRNA in VSMCs from aged mice.
Main Results:
- Aged mice exhibited increased atherosclerosis, aortic stiffness, and systolic dysfunction compared to young mice.
- Significantly higher cellular and mtROS levels were observed in aged mice.
- NOX4 expression was elevated in the vasculature and mitochondria of aged mice.
- NOX4 suppression in VSMCs reduced mtROS and improved cellular function.
- NOX4 expression correlated with age and atherosclerotic severity.
- Treatment with MitoTEMPO and NOX inhibitor decreased ROS, atherosclerosis, and preserved vascular/cardiac function in aged Apoe(-/-) mice.
Conclusions:
- NOX4, not NOX1/2, and mitochondrial oxidative stress are key mediators of aging-associated CVD in hyperlipidemic conditions.
- Targeting NOX4 activity/expression and utilizing mitochondrial antioxidants are promising therapeutic strategies for reducing aging-associated CVD.
Related Concept Videos
01:37Mitochondria
01:43Electron Transport Chain: Complex III and IV
01:46Electron Transport Chain: Complex I and II
ROS generation is regulated and maintained at moderate levels necessary...
01:45Mitochondrial Membranes
01:26Aging
Cellular Clock Theory
The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of...