Expression Of SSeCKS In Hyperoxia-induced Lung Injury Of New-born Rats

【Objective】We proposed to establish the new-born rats model of hyperoxia-induced lung injury ,and detect the expression of protein SSeCKS in lung tissue , then observe the sub-cellular location of SSeCKS and change of F-actin in pulmonary capillary endothelial cells in hyperoxia—induced lung injury in newborn rats..【Methods】1. Totally 64 rats at the age of 12 h were divided into two groups:air control group, hyperoxia-induced lung injury group. Then the rats were executed at the time points of 12 h,24 h,48 h and 72 h after hyperoxic exposure, the right upper lung was resected for the examination of histopathology and immunohistochemistry,right below lung for wet weight/dry weight, and left lung for detecting the expression of SSeCKS by Western blot analysis, the location of SSeCKS in the cells of lung tissue was tested by confocal scanning microscopy.2. 128 rats at the age of 12 h were divided into four groups: I)air control group , II) hyperoxia induced lung injury group,III)hyperoxia—induced lung injury plus R031-8220 group,IV) hyperoxia—induced lung injury plus saline group. Rats of group I were raised in room air while rats of other groups were raised in boxes with hyperoxia. The rats of group III were administered with R031-8220 for three days while the group IV were administered with saline at the same time.The rats were executed at the time point of 12 h,24 h,48 h and 72 h respectively after hyperoxic exposure, the right lung was resected for histopathology and W/D,and at the time point of 72 h the expression and sub-cellular location of SSeCKS and F-actin in pulmonary capillary endothelial cell were observed by double immunofluorescence. All the date were analyzed with SPSS 13.0 software.【Results】1. At 12 h :there were no signifeicant differences of W/D,HE and expression of protein SSeCKS between two groups; 24 h of the hyperoxic explosure,the pathologic changs occurred,the protein of SSeCKS started to increase;48 h of the hyperoxic explosure ,W/D increased,HE appeared alveolar wall engorge and inflammatory cell infiltration ,the protein of SSeCKS increased more;and at 72 h appeared obvious acute inflammation , including alveolar wall engorge , inflammatory cell infiltration and hemorrhage,the protein of SSeCKS reached to the peak ,and was located in the endothelial cells of interalveolar blood capillaries.2.1 W/D and HE in different groups: HE of groups II,III,IV started to appeare lung injury at 24 h;at 48 h ,W/D of groups II,III,IV increased ;at the time point of 72 h, the rats of groups II,IV appeared obvious acute inflammation,including inflammatory cell infiltration, hemorrhage and pulmonary edema., W/D was significantly higher than group I;compared to group II,IV,the pathological change of group III was slighter and W/D was significantly lower, R031-8220 reducded these changs.2.2 Expression and sub-cellular location of SSeCKS in pulmonary capillary endoialthel cell at the point of 72 h: in group I, most of protein SSeCKS distributed around the cell membrane; in groups II,IV, the expression of SSeCKS significantly increased than group I and most of protein SSeCKS was in cell-substance. Hyperoxia increased the expression and the sub-cellular location of SSeCKS in pulmonary capillary endothelial cell;in group III: the expression of SSeCKS significantly decreased than groups II,IV, and distributed around the cell membrane. The inhibitor of PKC (R031-8220) inhibited these changs.2.3 The F-actin in different groups at 72 h:in groups II,,IV ,the stimulation of hyperoxia resulted in the redistribution of F-actin in endothelial cells,R031-8220 inhibited these changs.【Conclusion】1) New-born rats may develop to lung injury after 24 h persistent exposure to hyperxia.2) Hyperoxia could increase the expression level of SSeCKS ,suggested SSeCKS involve in the process of hyperoxia induced lung injury.3) The expression and sub-cellular location of SSeCKS in pulmonary capillary endothelial cell may involve in the process of permeability injury of pulmonary capillary endothelial cell induced by hyperoxia.4) R031-8220 may have a protective role in hyperoxia-induced lung injury.