Proteomic Changes And Drug Effects On Nitric Oxide And Apoptosis Of Pulmonary Tissues During Simulated Weightlessness

ObjectiveLung function changes during weightlessness,and a certain degree pulmonary tissue injury comes out.Tail-suspension was used as weightlessness simulation to study proteomic changes of pulmonary tissues in rats during simulated weightlessness,so as to investigate the mechanism of lung injury caused by weightlessness.And the changes of cell apoptosis and nitric oxide in pulmonary tissues in rats during simulated weightlessness were examined after N-acetylcysteine and ginkgo biloba extract were used to treat respectively,so as to supply the theoretical foundation of medicine protection of lung injury caused by weightlessness.Methods1.proteomic analysis:20 Sprague-Dawley male rats(weight range,180 to 220 g) were randomly divided into 2 groups:tail-suspension for 7 day group,control group. Tail-suspension(-30°) was used to simulate the physiological effects of weightlessness. The pulmonary tissues in rats were taken out after the rats were anaesthetized by abdominal injection with the 10%hydration chloraldehyde(30ml/kg) when the suspension ended.Using two-dimensional electrophoresis(2-DE) the different expression map was established after the proteins were extracted from pulmonary tissues.And proteins express differently was determined by comparing the level of each dots with gel imaging software and manually.Digest in gel was performed first and proteins were identified by high definition mass spectrometry(HDMS) combining with database.Finally,the function of these identified proteins was known and classified.2.drug intervention:40 Sprague-Dawley male rats(weight range,180 to 220 g) were randomly divided into 4 groups:tail-suspension for 7 day group,control group, N-acetylcysteine treatment group and ginkgo biloba extract treatment group. Tail-suspension(-30°) was used to simulate the physiological effects of weightlessness. The rats were anaesthetized by abdominal injection with the 10%hydration chloraldehyde (30ml/kg) when the suspension ended.The pulmonary tissues of rats were cut into paraffin sections.The condition of cell apoptosis in pulmonary tissues was detected with in situ death detection,the expression of inducible nitric oxide synthase(iNOS) was detected with immunohistochemistry and the expression of bcl-2,bax and iNOS mRNA were detected by hybridization in situ.Results1.proteomic changes:The different expression map was established by using two-dimensional electrophoresis(2-DE) to separate the pulmonary tissue extract in rats of tail-suspension group and control group.17 differential expression proteins were determined by comparing the level of each dots with gel imaging software and manually, in which.13 differential expression proteins were up-regulated,3 differential expression proteins were down-regulated and 1 differential expression proteins disappeared.All were in the region of molecular masses of 15972-60317 and an isoelectric point of 4.65-8.61 respectively.Among them,the maximum and minimus change was 6.9 folds and 0.1 folds. 17 proteins were identified by HDMS and in which.13 proteins were up-regulated,3 proteins were down-regulated,1 protein disappeared.The identified proteins included cytoskeletal proteins,degradation system related proteins,proteins involved in signal transduction,metabolism and other cell function.They may be related to cell energy metabolism,stress and inflammatory response,cell injury and repair,intracellular signal transduction and other cell function,and play an important role in cell-mediated immune response,apoptosis,etc.2.drug intervention:The index of cell apoptosis in pulmonary tissues of rats suspended for 7 days was higher significantly than that of control group(P＜0.05),the index of cell apoptosis in pulmonary tissues of rats in N-acetylcysteine treatment group was lower significantly than that of tail-suspension for 7 days group(P＜0.05).And the expressions of bcl-2/bax mRNA in pulmonary tissues had the corresponding changes.The level of iNOS in pulmonary tissues of rats suspended for 7 days was higher significantly than that of control group(P＜0.05),the level of iNOS in pulmonary tissues of rats in N-acetylcysteine treatment group was lower significantly than that of tail-suspension for 7 days group(P＜0.05).And the expressions of iNOS mRNA in pulmonary tissues had the corresponding changes.At the same,the index of cell apoptosis in pulmonary tissues of rats suspended for 7 days was higher significantly than that of control group(P＜0.05),and the index of cell apoptosis in pulmonary tissues of rats in ginkgo biloba extract treatment group was lower significantly than that of tail-suspension for 7 days group(P＜0.05).And the expressions of bcl-2/bax mRNA in pulmonary tissues had the corresponding changes. The level of iNOS in pulmonary tissues of rats suspended for 7 days was higher significantly than that of control group(P＜0.05),the level of iNOS in pulmonary tissues of rats in ginkgo biloba extract treatment group was lower significantly than that of tail-suspension for 7 days group(P＜0.05).And the expressions of iNOS mRNA in pulmonary tissues had the corresponding changes.ConclusionThere were proteomic changes of pulmonary tissues in rats during simulated weightlessness,in which some proteins were up-regulated while some proteins were down-regulated,even disappeared.They may be related to cell energy metabolism,stress and inflammatory response,cell injury and repair,intracellular signal transduction and other cell function,and play an important role in the mechanism of lung injury caused by weightlessness.The levels of cell apoptotic and iNOS expression in pulmonary tissues of rats increased during simulated weightlessness.N-acetylcysteine and ginkgo biloba extract could suppress cell apoptosis and iNOS expression in pulmonary tissues of rats during simulated weightlessness.