Fig. 5.

Hyperoxia-induced senescent fetal lung fibroblasts have a secretory phenotype. A: concentrated medium of fetal fibroblasts exposed to normoxia (21% O₂) or hyperoxia (40% O₂) for 7 days or to etoposide was assessed by customized ELISA for protein levels of IL-1α, IL-1β, IL-6, IL-8, TNF-α, LAP, and PAI-1. B: total RNA was isolated from primary human fetal fibroblasts from these groups, and mRNA for IL-1α, IL-1β, IL-8, TGFβ, and MMP3 was quantified by quantitative PCR. Hyperoxia increased both mRNA and protein for a variety of proinflammatory and profibrotic mediators. Values are means ± SE from n = 5–7 samples. *P < 0.05 compared with normoxia group (one-way ANOVA).