[Oxidative stress induced the expression of Bax and p53 during the apoptosis of alveolar type II epithelial cell].
OBJECTIVE
To investigate the effects of oxidative stress on the survival and apoptosis of alveolar epithelial type II (ATII) cells, as well as the mechanisms of apoptosis.


METHODS
500 mumol/L H(2)O(2) was added into primary ATII cells at different times and cell viability, apoptotic ratio and the expression of Bax and p53 were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry (FCM) and Western blotting analysis, respectively. The change in mitochondrial membrane potential (MMP) was detected by fluorescence microscopy and FCM.


RESULTS
The cell viability and MMP were decreased by H(2)O(2) compared with the controls (F(1)=85.211, F(2)=72.453, respectively, both P<0.05). The cell apoptotic ratios were increased with the time of the stimulation prolonged compared with the controls (F=54.002, P<0.05). H(2)O(2) increased Bax and p53 protein levels (F(1)=28.118, F(2)=43.456, both P<0.05).


CONCLUSIONS
High level of oxidative stress can inhibit ATII cells proliferation, and induce cells apoptosis and decrease the MMP. Up-regulation of the expression of Bax and p53 may contribute to its apoptosis effects.
Fu
Yue-Qiang
YQ
Pediatric Intensive Care Unit, Children's Hospital, Chongqing University of Medical Sciences, Chongqing 400014, China. Fuyueqiang@sina.com.cn
Lu
Zhong-Yi
ZY
Fang
Fang
F
Tan
Li-Ping
LP
Kuang
Feng-Wu
FW
Wang
Xing-Yong
XY
Xu
Feng
F
D056809:Alveolar Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D017209:Apoptosis; D002470:Cell Survival; D002478:Cells, Cultured; D008297:Male; D053078:Membrane Potential, Mitochondrial; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
C494828:Bax protein, rat; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein