Regulatory Effects Of Trichinella Spiralis And Serine Protease Inhibitor On ERS Of Intestinal Epithelial Cells

In the conflict between parasite and host,parasites often interfere with the host’s defense system to benefit their own survival,the host eliminates the parasite’s harm to itself by activating its own defense system The accumulation of unfolded proteins or misfolded proteins in the endoplasmic reticulum can cause Endoplasmic reticulum stress Endoplasmic reticulum stress(ERS).ERS restores the normal physiological function of cells primarily by activating the unfolded protein response(UPR).If ERS continues or can not be alleviated,it will cause the production of pro-apoptotic factors and eventually lead to cell apoptosis.In recent years,research on the pathogenesis of intestinal dysfunction after parasitic infection has become a hot topic,and a number of experimental data have proved that various parasitic infections can trigger host ERS,but there is little exploration into why parasites cause host ERS.Therefore,this study mainly explored whether Trichinella,selected kazal type serine protease inhibitor(Ts Ka SPI)contribute to the invasion of intestinal epithelial cells in the infectious stage of Trichinella spiralis by regulating ERS.In order to study whether Trichinella regulates the ERS of host intestinal epithelial cells during the invasion of host,this study used Trichinella infection mouse animal model to analyze the damage of jejunal tissue by Hematoxylin-eddyr staining(H&E)staining,TUNEL to analyze the apoptosis of intestinal tissue cells,Real-time PCR(RT-q PCR)to detect the transcriptional level change of ERS-related proteins,and Western blotting to detect the activation of ERS-related proteins and apoptosis-related proteins;the results showed that in the intestinal stage of Trichinella infection,ERS appears in the jejunal tissue,and during the cyclic phase of Trichinella infection,the ERS of the jejunal tissue begins to recede.In order to further study the regulatory effect of Trichinella serine protease inhibitors(Ts SPI)on ERS,this study used pig intestinal epithelial cells(IPECs)to establish an in vitro culture model of Ts Ka SPI,one of the important components of Trichinella ES antigen,and detected the expression of ERS-related proteins(Bip,PERK,IRE1,ATF6)and apoptotic-related proteins(JNK,CHOP,caspase-12)by Western blotting,Flow cytometry(FCM)detected the apoptosis of IPECs,and RT-q PCR detected TLR2 and TLR4 The changes of Bcl-2,Bcl-x L,Bax,Fas-related factors and NF-κB signaling pathways,Enzyme-linked immunosorbent assay(ELISA)detected the secretion of inflammatory cytokines,and verified the interaction between the occurrence of intestinal epithelial cells ERS and the activation of NF-κB through the use of inhibitors;the results showed that Ts Ka SPI can activate intestinal epithelial cell ERS,induce apoptosis,and activate the NF-κB signaling pathway to promote the secretion of inflammatory factors,at the same time The correlation between NF-κB and ERS signaling pathways was studied,and inhibition experiments confirmed that the occurrence of ERS is usually accompanied by the activation of NF-κB,and the two regulate each other.In vivo experiments using intraperitoneal injection of Ts Ka SPI mouse immune model,RT-q PCR and Western blotting to detect the activation of ERS and apoptotic-related proteins also confirmed that Ts Ka SPI can activate intestinal epithelial cells to generate ERS.In conclusion,Trichinella and Ts Ka SPI antigen can promote apoptosis by activating the ERS response of intestinal epithelial cells,and at the same time,it can also activate the NF-κB signaling pathway and promote the occurrence and development of inflammatory response.The results laid a foundation for further exploring the relationship between parasitic diseases and host ERS responses,and for studying the pathogenesis of intestinal dysfunction after Trichinella infection.