Key Event Overview
Please follow link to widget page to edit this section.
If you manually enter text in this section, it will get automatically altered or deleted in subsequent edits using the widgets.
AOPs Including This Key Event
|AOP Name||Event Type||Essentiality|
|Oxidative Stress Leading to Hypertension||KE||Strong|
|Homo sapiens||Homo sapiens||NCBI|
|Bos taurus||Bos taurus||NCBI|
|Mus musculus||Mus musculus||NCBI|
|Rattus norvegicus||Rattus norvegicus||NCBI|
Level of Biological Organization
How this Key Event works
Nitric oxide (NO), constitutively produced by endothelial nitric oxide synthase (eNOS), is an important regulator of vascular homeostasis. Endothelial-derived NO promotes vasodilation and protects against atherogenesis through the inhibition of vascular smooth muscle cell proliferation and migration, platelet aggregation and adhesion, and leukocyte adherence. Its effects have an influence on vascular resistance, blood pressure, vascular remodeling and angiogenesis (Luo et al., 2000). Dysfunctional eNOS as a result of eNOS uncoupling leads to a decrease or loss of NO bioavailability and an elevation of superoxide production (Crabtree et al., 2009). The imbalance of NO and superoxide is associated with many cardiovascular diseases such as hypertension, atherosclerosis, hypercholesterolemia, and diabetes mellitus.
How it is Measured or Detected
NO production can be measured through the conversion of L-arginine to L-citrulline (de Bono et al., 2007) , in situ fluorescent signal detection with fluorescent indicator DAF-2 DA (Itoh et al., 2000; Nagata et al., 1999; Qiu et al., 2001), EPR spin-trapping (Xia et al., 2000), and the determination of total nitrate and nitrite concentration (Crabtree et al., 2009; Du et al., 2013).
Evidence Supporting Taxonomic Applicability
NO depletion was observed in humans, cows, mice and rats (Chen et al., 2010; Crabtree et al., 2009; De Pascali et al., 2014; Du et al., 2013; Jayaram et al., 2015).
de Bono, J.P., Warrick, N., Bendall, J.K., Channon, K.M., and Alp, N.J. (2007). Radiochemical HPLC detection of arginine metabolism: Measurement of nitric oxide synthesis and arginase activity in vascular tissue. Nitric Oxide 16, 1–9.
Chen, X., Xu, J., Feng, Z., Fan, M., Han, J., and Yang, Z. (2010). Simvastatin combined with nifedipine enhances endothelial cell protection by inhibiting ROS generation and activating Akt phosphorylation. Acta Pharmacol. Sin. 31, 813–820.
Crabtree, M.J., Tatham, A.L., Al-Wakeel, Y., Warrick, N., Hale, A.B., Cai, S., Channon, K.M., and Alp, N.J. (2009). Quantitative regulation of intracellular endothelial nitric-oxide synthase (eNOS) coupling by both tetrahydrobiopterin-eNOS stoichiometry and biopterin redox status: insights from cells with tet-regulated GTP cyclohydrolase I expression. J. Biol. Chem. 284, 1136–1144.
De Pascali, F., Hemann, C., Samons, K., Chen, C.-A., and Zweier, J.L. (2014). Hypoxia and reoxygenation induce endothelial nitric oxide synthase uncoupling in endothelial cells through tetrahydrobiopterin depletion and S-glutathionylation. Biochemistry (Mosc.) 53, 3679–3688.
Du, Y., Navab, M., Shen, M., Hill, J., Pakbin, P., Sioutas, C., Hsiai, T.K., and Li, R. (2013). Ambient ultrafine particles reduce endothelial nitric oxide production via S-glutathionylation of eNOS. Biochem. Biophys. Res. Commun. 436, 462–466.
Dumitrescu, C., Biondi, R., Xia, Y., Cardounel, A.J., Druhan, L.J., Ambrosio, G., and Zweier, J.L. (2007). Myocardial ischemia results in tetrahydrobiopterin (BH4) oxidation with impaired endothelial function ameliorated by BH4. Proc. Natl. Acad. Sci. U. S. A. 104, 15081–15086.
Itoh, Y., Ma, F.H., Hoshi, H., Oka, M., Noda, K., Ukai, Y., Kojima, H., Nagano, T., and Toda, N. (2000). Determination and bioimaging method for nitric oxide in biological specimens by diaminofluorescein fluorometry. Anal. Biochem. 287, 203–209.
Jayaram, R., Goodfellow, N., Zhang, M.H., Reilly, S., Crabtree, M., De Silva, R., Sayeed, R., and Casadei, B. (2015). Molecular mechanisms of myocardial nitroso-redox imbalance during on-pump cardiac surgery. Lancet Lond. Engl. 385 Suppl 1, S49.
Luo, Z., Fujio, Y., Kureishi, Y., Rudic, R.D., Daumerie, G., Fulton, D., Sessa, W.C., and Walsh, K. (2000). Acute modulation of endothelial Akt/PKB activity alters nitric oxide–dependent vasomotor activity in vivo. J. Clin. Invest. 106, 493–499.
Nagata, N., Momose, K., and Ishida, Y. (1999). Inhibitory effects of catecholamines and anti-oxidants on the fluorescence reaction of 4,5-diaminofluorescein, DAF-2, a novel indicator of nitric oxide. J. Biochem. (Tokyo) 125, 658–661.
Qiu, W., Kass, D.A., Hu, Q., and Ziegelstein, R.C. (2001). Determinants of shear stress-stimulated endothelial nitric oxide production assessed in real-time by 4,5-diaminofluorescein fluorescence. Biochem. Biophys. Res. Commun. 286, 328–335.
Xia, Y., Cardounel, A.J., Vanin, A.F., and Zweier, J.L. (2000). Electron paramagnetic resonance spectroscopy with N-methyl-D-glucamine dithiocarbamate iron complexes distinguishes nitric oxide and nitroxyl anion in a redox-dependent manner: applications in identifying nitrogen monoxide products from nitric oxide synthase. Free Radic. Biol. Med. 29, 793–797.