Figure 2

Effects of hyperoxia on stretch-induced macrophage inflammatory protein-2 (MIP-2) mRNA expression and DNA binding in JNK knockout mice. (a) MIP-2 mRNA (top panel), GAPDH mRNA (middle panel), and arbitrary units (bottom panel) from control, non-ventilated mice, and mice ventilated at a tidal volume (V_T) 30 ml/kg for one hour with room air (RA) or hyperoxia (n = 5 per group). The ratio of MIP-2 mRNA to GAPDH was expressed in arbitrary units. The expression of MIP-2 mRNA was performed by RNase protection assay. (b) Nuclear proteins of lung tissue from control, non-ventilated mice, and mice ventilated at a V_T of 30 ml/kg without or with hyperoxia were incubated with or without excess unlabeled activator protein-1 (AP-1) or nuclear factor-kappa-B (NF-κB) consensus oligonucleotide (negative control) (n = 5 per group). Arbitrary units were expressed as increase of DNA-binding activity as described in Materials and methods. *p < 0.05 versus control, non-ventilated mice; †p < 0.05 versus all other groups. GAPDH, glyceraldehyde-3-phosphate dehydrogenase; JNK, c-Jun NH₂-terminal kinase; NC, control, non-ventilated mice; O2, mice with hyperoxia; WT, wild-type.