| ObjectiveThe aim of this study was to explore the pathophysiological characteristics of blood and organs during the development of sepsis by using a cecal ligation and puncture(CLP)-induced sepsis mouse model.And on this basis,the inmunoregulatory role of IL-22/IL-22R1 axis in the process of sepsis was also investigated.Methods1.A CLP-induced sepsis mouse model was established for analyzing the survival rate.Then six mice in sham-operated group and CLP group were executed at 8,32 and 72 h after operation,respectively.The histomorphological characteristics of multiple organs in the two groups at different time points were observed by H&E staining.2.According to the histopathological changes of organs,the expression of IL-22/IL-22R1 axis and related cytokines in various organs of mice was analyzed by Luminex,Q-PCR and iumunohistochemistry,in order to explore the potential role of IL-22/IL-22R1 axis in the process of sepsis,and to understand the immunoregulatory status in organs during the progress of sepsis.3.The serum proteomic changes of CLP mice and sham-operated mice at different time points were analyzed by iTRAQ technique and subjected to GO and cluster analysis in order to confirm the expression of IL-22 and other cytokines and to find a group or several groups of proteomes that can be used to monitor the progress of sepsis.Results1.Obvious morphological changes in organs of CLP mice were found at 8 h after modeling and more serious damage was found at 32 h after modeling.However,the histomorphology of most organs was improved significantly at 72 h after operation,but that of thymus and spleen was not improved yet.2.In the early stage of sepsis,the expression of IL-22 and IL-22R1 in various organs of CLP mice increased significantly,and maintained the high level to 32h after operation,and then they decreased rapidly to almost normal level,while the increase of IL-22BP expression lagged behind that of IL-22 and IL-22R1,which mainly antagonized the effects of IL-22/IL-22R1 axis during the recovery period of CLP mice.3.During the recovery stage of sepsis,the IL-22 mRNA levels in thymus and spleen of CLP mice decreased significantly,suggesting that even in the recovery stage,the immune function of mice was still impaired.4.A total of 258 differentially expressed proteins in the serum of mice were identified using iTRAQ between the sham group and CLP group at different time points.Then the differentially expressed proteins were subjected to GO classification,enrichment and cluster analysis,which yielded two groups of more meaningful proteins.One group rose rapidly in the early stage after operation,and then began to decline,while the other group rose rapidly in the early stage after operation,and continued to rise to 32 h after operation,and then began to decline.These two proteins had obvious characteristics in the course of sepsis and potential application value.Conclusion1.The histopathological characteristics of various organs of CLP mice were not consistent.In addition,the histological feature of thymus and spleen was not improved significantly even during the recovery period,which provided a histological basis for the further use of immunosuppression in the later stage of sepsis.2.IL-22/IL-22R1 axis participated in the evolution of sepsis in the early stages of sepsis,and its role continued consistently until the mouse lived through a life-threatening period.When the mice passed the life-threatening period,the elevated IL-22BP level in the organs inhibited the role of the IL-22/IL-22R1 axis due to its higher affinity with the IL-22,and played a role in promoting tissue repair during the recovery period.3.Serum proteomics study found two groups of proteomes with more characteristics,which may have potential application values.This study provides an experimental basis for determining the role of IL-22 in the pathophysiological progress of sepsis,and a new perspective and possible target for clinical treatment of sepsis. |
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