| Part Ⅰ Effects of hyperoxia on exposure of IL-1beta and IL-6 in lung tissue of premature neonatal ratsObjective To investigate the effect of hyperoxia exposure on the expression of interleukin-1 beta(IL-1 beta)and IL-6 in lung tissue of premature neonatal rats,and to study the correlation between IL-1 beta and IL-6 and bronchopulmonary dysplasia(BPD).Methods Premature SD(Sprague-Dawley)rats at 21 days of gestation were caesarean section and fed for 1 day.Premature rats were randomly divided into two groups:air group(n=40)and hyperoxia group(n=40).Premature rats in the two groups were fed in normal pressure air and hyperoxia chamber respectively.Premature rats were tested every day and their weight and body length were recorded every other day.Lung tissue specimens of premature rats in two groups were collected on the 1st,4th,7th,10th and 14th days after exposure to air and high concentration oxygen respectively.Hematoxylin-eosin staining(HE)was used to detect the pathological changes of lung tissues of premature rats exposed to air and hyperoxia at different time points.Elisa was used to detect the expression of IL-1beta and IL-6 in lung tissues of premature rats exposed to air and hyperoxia at different time points.Results(1)Compared with the air group,the weight of premature rats in the hyperoxia group was significantly lower than that in the air group on the 7th,10th and 14th days,with statistical significance(p<0.05).(2)Compared with the air group,with the prolongation of hyperoxia exposure time,the typical pathological changes of bronchopulmonary dysplasia(BPD)appeared gradually in the lung tissue of premature rats in the hyperoxia group.(3)Compared with the air group,the expression of IL-1beta in lung tissues of premature rats in the hyperoxia group increased on the 7th,10th and 14th days after hyperoxia exposure,and the difference was statistically significant(p<0.05).(4)Compared with the air group,the expression of IL-6 in lung tissue decreased on the 1st and 4th day after hyperoxia exposure,and increased on the 7th and 10th day after hyperoxia exposure(p<0.05),while the expression of IL-6 decreased on the 14th day after hyperoxia exposure(p>0.05)Conclusion(1)Hyperoxia exposure can lead to slow weight gain and growth retardation in premature neonatal rats.(2)Hyperoxia exposure can block the lung development of premature neonatal rats and aggravate with the prolongation of hyperoxia exposure time.Typical pathological manifestations of BPD appear.(3)Hyperoxia exposure can increase the expression of IL-lbeta and IL-6 in the lung of premature rats,which may be one of the important mechanisms for the development of BPDPart Ⅱ:The expression of long-chain non-coding RNA MALAT11 and its relationship with apoptosis in lung tissue of premature rats exposed to hyperoxiaObjective To investigate the effect of hyperoxia exposure on the expression of long-chain non-coding RNA MALAT in lung tissue of premature rats and its relationship with apoptosis of lung tissue,and to explore the role of long-chain non-coding RNA MALAT expression in the development of hyperoxia-induced lung injury.Methods(1)Premature SD(Sprague-Dawley)rats were delivered by caesarean section at 21 days of gestation.After feeded for 1 day,they were randomly divided into two groups:air group(n=40)and hyperoxia group(n=40).Premature rats in the two groups were fed in normal pressure air and hyperoxia chamber,respectively.Lung tissue samples of premature rats in two groups were collected at 1,4,7,10 and 14 days after exposure to air and high concentration of oxygen respectively.RNA was extracted.Real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)was used to detect the expression of MALAT1 in lung tissue of premature rats at different time points of exposure to air and hyperoxia.Tunel was used to detect the effect of MALAT1 on apoptosis of lung cellsRresults(1)Compared with the air group,the relative expression of MALAT1 in lung tissue of premature rats in the hyperoxia group was lower than that in the air group on the 1st,10th and 14th day of hyperoxia exposure,with no significant difference(p>0.05);the expression of MALAT1 in the 4th and 7th day was higher than that in the air group,with significant difference(p<0.05).(2)Compared with the air group,apoptosis in lung tissue of premature rats in the hyperoxia group was higher than that in the air group from the first day.With the prolongation of hyperoxia time,apoptosis became more and more obviousConclusion(1)Hyperoxia exposure can induce the relative increase of MALAT1 in lung tissue of premature neonatal rats,suggesting that MALAT1 may be involved in the development of bronchopulmonary dysplasia.(2)Hyperoxia exposure can induce apoptosis in lung tissue of neonatal premature rats.Combining with previous studies in this group,it is suggested that MALAT1 has protective effect on bronchopulmonary dysplasia. |
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