| First Author | Matsushima S | Year | 2013 |
| Journal | Circ Res | Volume | 112 |
| Issue | 8 | Pages | 1135-49 |
| PubMed ID | 23476056 | Mgi Jnum | J:213317 |
| Mgi Id | MGI:5584081 | Doi | 10.1161/CIRCRESAHA.111.300171 |
| Citation | Matsushima S, et al. (2013) Broad suppression of NADPH oxidase activity exacerbates ischemia/reperfusion injury through inadvertent downregulation of hypoxia-inducible factor-1alpha and upregulation of peroxisome proliferator-activated receptor-alpha. Circ Res 112(8):1135-49 |
| abstractText | RATIONALE: NADPH oxidase (Nox) 2 and Nox4 are major components of the Nox family which purposefully produce reactive oxidative species, namely O2(-) and H2O2, in the heart. The isoform-specific contribution of Nox2 and Nox4 to ischemia/reperfusion (I/R) injury is poorly understood. OBJECTIVE: We investigated the role of Nox2 and Nox4 in mediating oxidative stress and myocardial injury during I/R using loss-of-function mouse models. METHODS AND RESULTS: Systemic (s) Nox2 knockout (KO), sNox4 KO, and cardiac-specific (c) Nox4 KO mice were subjected to I/R (30 minutes/24 hours, respectively). Both myocardial infarct size/area at risk and O2(-) production were lower in sNox2 KO, sNox4 KO, and cNox4 KO than in wild-type mice. Unexpectedly, however, the myocardial infarct size/area at risk was greater, despite less O2(-) production, in sNox2 KO+cNox4 KO (double-KO) mice and transgenic mice (Tg) with cardiac-specific expression of dominant-negative Nox, which suppresses both Nox2 and Nox4, than in wild-type or single KO mice. Hypoxia-inducible factor-1alpha was downregulated whereas peroxisome proliferator-activated receptor-alpha was upregulated in Tg-dominant-negative Nox mice. A cross with mice deficient in prolyl hydroxylase 2, which hydroxylates hypoxia-inducible factor-1alpha, rescued the I/R injury and prevented upregulation of peroxisome proliferator-activated receptor-alpha in Tg-dominant-negative Nox mice. A cross with peroxisome proliferator-activated receptor-alpha KO mice also attenuated the injury in Tg- dominant-negative Nox mice. CONCLUSIONS: Both Nox2 and Nox4 contribute to the increase in reactive oxidative species and injury by I/R. However, low levels of reactive oxidative species produced by either Nox2 or Nox4 regulate hypoxia-inducible factor-1alpha and peroxisome proliferator-activated receptor-alpha, thereby protecting the heart against I/R, suggesting that Noxs also act as a physiological sensor for myocardial adaptation. |
