Figure 5. mtH₂O₂ attenuation prevents hypoxia-induced Nox expression.

Lit Cont and MCAT mice were exposed to normoxic or hypoxic conditions for 3 weeks. Whole lung homogenates were collected from Lit Cont, MCAT, and Tg^hSOD2 mice. Nox mRNA values are relative to GAPDH, or 9S and expressed as fold-change vs. Normoxia. Protein samples are normalized to β-Actin. (A) MCAT expression attenuated hypoxiainduced Nox2 mRNA. Each bar represents mean ± SEM lung Nox2 mRNA (n = 9), *p < 0.05 compared to all other groups. (B) MCAT expression inhibited hypoxia-induced Nox2 protein levels. Each bar represents mean ± SEM lung Nox2 protein (n = 2 – 3), *p < 0.05 compared to all other groups. (C) MCAT expression prevented elevation of hypoxia-induced Nox4 mRNA levels. Each bar represents mean ± SEM lung Nox4 mRNA (n = 7 – 10), *p < 0.05 compared to all other groups. (D) Nox4 hypoxia-induced protein expression was attenuated in MCAT mice. Each bar represents mean ± SEM lung Nox4 protein (n = 3 – 4), *p < 0.05 compared to all other groups. (E) Hypoxia-induced lung Nox2 mRNA expression was exacerbated in Tg^hSOD2. Each bar represents mean ± SEM lung Nox2 mRNA (n = 6 – 11), *p < 0.05 compared to Lit Cont Normoxia and ^#p < 0.05 compared to Lit Cont Hypoxia. (F) Hypoxia elevates lung Nox2 protein in both Lit Cont and Tg^hSOD2. Each bar represents mean ± SEM lung Nox2 protein (n = 3), *p < 0.05 compared to all other groups. (G) Hypoxia-induced Nox4 mRNA expression is exacerbated in hypoxia-exposed Tg^hSOD2. Each bar represents mean ± SEM lung Nox4 mRNA (n = 6), *p < 0.05 compared to Lit Cont Normoxia and ^#p < 0.05 compared to Lit Cont Hypoxia. (H) Hypoxia increases lung Nox4 protein in Lit Cont and this increase is exacerbated in the hypoxia Tg^hSOD2 model. Each bar represents mean ± SEM lung Nox4 protein (n = 3 – 4), *p < 0.05 compared to Lit Cont Normoxia and ^#p < 0.05 compared to Lit Cont Hypoxia.