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Updated: May 28, 2026
Bioluminescence Imaging of NADPH Oxidase Activity in Different Animal Models
Published on: October 22, 2012
NAD(P)H oxidase and eNOS play differential roles in cytomegalovirus infection-induced microvascular dysfunction
Igor L Leskov1, Jennifer Whitsett, Jeannette Vasquez-Vivar
1Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
Abstract:
Primary cytomegalovirus (CMV) infection promotes oxidative stress and reduces nitric oxide (NO) bioavailability in endothelial cells. These events are among the earliest vascular responses to cardiovascular risk factors. We assessed the roles of NAD(P)H oxidase and NO bioavailability in microvascular responses to persistent CMV infection alone or with hypercholesterolemia. Wild-type (WT) or gp91(phox) (NAD(P)H oxidase subunit) knockout mice received mock inoculum or 3×10(4) PFU murine CMV (mCMV) ip 5 weeks before placement on a normal or high-cholesterol diet (HC) for 4 weeks before assessment of arteriolar function and venular blood cell recruitment using intravital microscopy. Some WT groups received sepiapterin (a precursor of the nitric oxide synthase cofactor tetrahydrobiopterin) or apocynin (NAD(P)H oxidase inhibitor/antioxidant). Endothelium-dependent vasodilation was impaired in mCMV vs mock WT, regardless of diet. This was not affected by sepiapterin, and pharmacological inhibition of nitric oxide synthase reduced dilation similarly in mock and mCMV mice. Apocynin or deficiency of total, but not blood cell or vascular wall only (tested using bone marrow chimeras), gp91(phox) protected against arteriolar dysfunction. Blood cell recruitment was induced by mCMV-HC. Sepiapterin, but not NAD(P)H oxidase deficiency/apocynin, reduced leukocyte accumulation, whereas platelet adhesion was reduced by sepiapterin, apocynin, or total, platelet-specific, or vascular wall gp91(phox) deficiency. These data implicate activation of both hematopoietic and vessel wall NAD(P)H oxidase in mCMV-induced arteriolar dysfunction and platelet and vascular NAD(P)H oxidase in the thrombogenic phenotype induced by mCMV-HC. In contrast, findings with sepiapterin suggest that eNOS dysfunction, perhaps uncoupling, mediates venular, but not arteriolar, responses to mCMV-HC, thus indicating that NAD(P)H oxidase and eNOS differentially regulate microvascular responses to mCMV.
Insights
Cytomegalovirus (CMV) infection impairs blood vessel function by activating NAD(P)H oxidase, contributing to cardiovascular issues. Targeting this enzyme may offer new therapeutic strategies for CMV-related vascular complications.
Area of Science:
- Cardiovascular Research
- Infectious Diseases
- Vascular Biology
Background:
- Primary cytomegalovirus (CMV) infection induces oxidative stress and reduces nitric oxide (NO) bioavailability, early vascular responses linked to cardiovascular risk.
- NAD(P)H oxidase and NO bioavailability are critical in microvascular responses to cardiovascular risk factors and infections.
Purpose of the Study:
- To investigate the roles of NAD(P)H oxidase and NO bioavailability in microvascular dysfunction during persistent CMV infection, alone or with hypercholesterolemia.
- To elucidate the specific cellular sources (hematopoietic vs. vascular wall) of NAD(P)H oxidase involved in CMV-induced vascular changes.
Main Methods:
- Utilized wild-type (WT) and gp91(phox) knockout mice subjected to murine CMV (mCMV) infection.
- Administered normal or high-cholesterol diets and assessed microvascular function (vasodilation, blood cell recruitment) using intravital microscopy.
- Employed pharmacological interventions including sepiapterin (NO precursor) and apocynin (NAD(P)H oxidase inhibitor/antioxidant).
Main Results:
- CMV infection impaired endothelium-dependent vasodilation independently of diet, with NAD(P)H oxidase inhibition/deficiency protecting against this dysfunction.
- CMV infection combined with hypercholesterolemia induced blood cell recruitment; sepiapterin reduced leukocyte accumulation, while NAD(P)H oxidase inhibition reduced platelet adhesion.
- NAD(P)H oxidase activation in both hematopoietic and vascular cells contributes to CMV-induced arteriolar dysfunction and thrombotic events.
Conclusions:
- Activation of both hematopoietic and vascular NAD(P)H oxidase is implicated in CMV-induced arteriolar dysfunction and thrombogenic phenotypes.
- Endothelial nitric oxide synthase (eNOS) dysfunction differentially mediates venular responses to CMV and hypercholesterolemia, distinct from arteriolar responses.
- NAD(P)H oxidase and eNOS play differential roles in regulating microvascular responses to CMV infection.
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