Fig. 4.

Increased expression of lung glutathione peroxidase 2 (Gpx2) in Nrf2^+/+ newborn mice exposed to hyperoxia. A: increased expression of lung Gpx2 above room air was found in newborn Nrf2^+/+ mice exposed to hyperoxia for 24, 48, and 72 h. Minimal induction of lung Gpx2 expression was found in Nrf2^−/− mice exposed to hyperoxia. Nrf2^+/+ lung Gpx2 expression was significantly greater than Nrf2^−/− at 48 and 72 h of hyperoxia (*P < 0.003 and **P < 0.0001, respectively), n = 3–7 (per group). B: Gpx2 protein was significantly decreased in lung from 4-day-old Nrf2^−/− mice exposed to 72 h of hyperoxia (P < 0.004). C: representative example of Gpx2 Western blot. D: decreased Gpx2 staining in 4-day-old Nrf2^−/− mice exposed to 72 h of hyperoxia by immunohistochemistry (arrows point to Gpx2 staining). n = 5–6 (per group).