Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130, USA.
Free Radic Biol Med. 2011 Dec 15;51(12):2300-8. doi: 10.1016/j.freeradbiomed.2011.09.039. Epub 2011 Oct 6.
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.
原发性巨细胞病毒 (CMV) 感染会促进内皮细胞中的氧化应激和减少一氧化氮 (NO) 的生物利用度。这些事件是心血管危险因素最早的血管反应之一。我们评估了 NAD(P)H 氧化酶和 NO 生物利用度在单纯巨细胞病毒感染或伴有高胆固醇血症的微血管反应中的作用。野生型 (WT) 或 gp91(phox) (NAD(P)H 氧化酶亚基) 敲除小鼠在接受模拟接种或 3×10(4) PFU 鼠巨细胞病毒 (mCMV) 腹腔注射 5 周后，分别接受正常或高胆固醇饮食 (HC) 4 周，然后使用活体显微镜评估小动脉功能和静脉血细胞募集。一些 WT 组接受了蝶酰谷氨酸 (一氧化氮合酶辅助因子四氢生物蝶呤的前体) 或 apocynin (NAD(P)H 氧化酶抑制剂/抗氧化剂)。无论饮食如何，mCMV 感染的 WT 内皮依赖性血管舒张均受损。这不受蝶酰谷氨酸的影响，而一氧化氮合酶的药理学抑制在模拟和 mCMV 小鼠中同样减少了舒张。apocynin 或总 gp91(phox) 的缺乏（使用骨髓嵌合体进行了测试），但不是血细胞或血管壁（血管壁仅测试）的缺乏，可预防小动脉功能障碍。mCMV-HC 诱导血细胞募集。蝶酰谷氨酸，但不是 NAD(P)H 氧化酶缺乏/apocynin，可减少白细胞积聚，而血小板黏附则可通过蝶酰谷氨酸、apocynin 或总、血小板特异性或血管壁 gp91(phox) 缺乏减少。这些数据表明，巨细胞病毒感染诱导的小动脉功能障碍与巨细胞病毒-HC 诱导的血小板和血管 NAD(P)H 氧化酶的血小板和血管 NAD(P)H 氧化酶的激活有关。相比之下，蝶酰谷氨酸的发现表明，内皮型一氧化氮合酶 (eNOS) 功能障碍，可能是解偶联，介导 mCMV-HC 对 venular 的反应，但不介导对小动脉的反应，这表明 NAD(P)H 氧化酶和 eNOS 对 mCMV 的微血管反应具有不同的调节作用。
