Differential expression of mitochondrial proteome and NADH-dehydrogenase subunit 4 in type II alveolar epithelial cell of primary fetal rat exposed to hyperoxia

Objective To explore the effect of hyperoxia exposure on the mitochondrial proteome and the expression of NADH-dehydrogenase subunit 4 (ND4) of type Ⅱ alveolar epithelial cells (AEC Ⅱ) of primary fetal rat. Methods The primary fetal rats (gestation 19～20 d) AEC Ⅱ were cultured in vitro and then were randomly divided into 2 groups. Air-exposed control group and hyperoxia-exposed group. The differential expression of mitoehondrial proteome was analyzed by two-dimensional electrophoresis. The expression of ND4 mRNA and protein was determined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot, respectively. Results Compared with air control group, we found 55 protein spots with differential expression after 24 h of hyperoxia. After exposure to hyperoxia for 12 h and 24 h, the expression of AEC Ⅱ ND4 mRNA (1.20±0. 12 vs 4.61±0. 43,0. 69±0. 07 vs 2.15± 0. 14, PF 0.05 for all). Conclusions The changes of AEC Ⅱ mitoehondrial (including respiratory chain) function might play a critical role in the development of hyperoxia lung injury. Key words: Hyperoxia;  Pulmonary alveoli;  Epithelial cells;  Mitochondria/proteins; Proteome;  NADH-dehydrogenase