Detection of p16 promoter methylation in premature rats with chronic lung disease induced by hyperoxia.
BACKGROUND
The aim of the present study was to investigate p16 promoter methylation in premature rats with chronic lung disease (CLD) induced by hyperoxia.


METHODS
Eighty Wistar rats were randomized into the hyperoxia group (fraction of inspired oxygen [FiO(2)] = 900 mL/L) or the control group (FiO(2) = 210 mL/L), 40 for each group. Semi-nested methylation-specific polymerase chain reaction (sn-MSP) was applied to detect p16 promoter hypermethylation in lung tissues. Additionally, p16 mRNA and protein expression was detected on reverse transcription-polymerase chain reaction (RT-PCR), western blot and the strept actividin-biotin complex method.


RESULTS
Extended exposure to hyperoxia led to increased methylation, and the methylation level reached a peak in the period of maximum pulmonary fibrosis in the hyperoxia group, while the methylation did not occur in the control group. The methylation rates on semi-nested PCR (sn-PCR) and nested-MSP were, respectively, 52.5% and 42.5% in the hyperoxia group. There was no statistically significant difference between the two methods. The p16 mRNA and protein expression was significantly higher in those with p16 promoter hypermethylation than those without.


CONCLUSIONS
Exposure to hyperoxia may induce p16 promoter hypermethylation in lung tissues in premature rats, and methylation risk increases as exposure extends. p16 promoter methylation induced by hyperoxia may be one of the mechanisms for low p16 mRNA and protein expression.
Yue
Xiaohong
X
Department of Pediatrics, Shengjing Hospital of China Medical University, Shenyang, China.
Fu
Jianhua
J
Xue
Xindong
X
Gao
Hong
H
Liu
Dongyan
D
Zong
Zhihong
Z
Wang
Wei
W
Li
Hui
H
Yuan
Zhengwei
Z
D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation; D018496:Hyperoxia / Q000150:complications*; D008168:Lung / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011658:Pulmonary Fibrosis / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
D019941:Cyclin-Dependent Kinase Inhibitor p16; D012333:RNA, Messenger