Protective Effect Of Peptidoglycan On Epithelial Cells Anaphylaxis

In this study,the intestinal epithelial cells of juvenile carp were used as the research object,and Bacillus subtilis was used as the tested strain to isolate the peptidoglycan.This experiment was conducted to investigate the protective effects of different concentration of B.subtilis peptidoglycan on the?-conglycinin-induced inflammatory lesions in intestinal epithelial cells of juvenile carp.In 24-cell microplates,the intestinal epithelial cells?IECs?of juvenile carp were primarily cultured for 72 h?in 26oC and 6%CO₂?,and then the IECs were randomly divided into 6 groups with 4 replicates per group.One of the 6 groups was set as negative control group,and the other groups were all supplemented with 1.0 mg/m L?-conglycinin in culture medium in order to establish inflammatory lesions.After 24 h further culture in the same condition,the culture medium was changed into the B.subtilis peptidoglycan culture medium with 0?positive control group?,0.15,0.30,0.45 and 0.60 mg/m L,respectively.The samples were collected to measure the antioxidant and anti-inflammatory indices after 12 h,24 h and 36 h B.subtilis peptidoglycan culture.The results showed as follows:?-conglycinin exposure significantly decreased the ASA,AHR,SOD,CAT,GPx,and increased the content of PC and the mRNA expression of inflammatory cytokines?IL-1?,IL-8,TNF-?,IL-10 and TGF-??.The 12,24 and 36 hours after the peptidoglycan were given,the activity of ASA,AHR,SOD,CAT,GPx and the content of PC in the cells were decreased in a dose-dependent manner;and the mRNA levels of IL-1?,IL-8 and TNF-?1 were down-regulated and IL-10 and TGF-?were up-regulated.The expression of IL-1?,IL-8 and TNF-?1 mRNA in the positive control group was significantly higher than that in the negative control group,but could be significantly inhibited by different concentrations of peptidoglycan,the higher the concentration,the stronger the inhibition.The expression of TNF-?1mRNA in 0.15 mg/m L peptidoglycan treatment group,the mRNA expression of IL-1?and IL-8 in 0.30 mg/m L peptidoglycan treatment group,the expression of IL-10 and TGF-?mRNA in positive control group are Significantly higher than the negative control.With the increase of peptidoglycan concentration,the expression of IL-10 and TGF-?mRNA increased significantly,but the expression of TGF-?mRNA in 0.15 mg/m L peptidoglycan group was not significantly different from that of the positive control group.Conclusion:?-conglycinin can induce oxidative damage in juvenile intestinal epithelial cells,and stimulate the development of inflammation by up-regulating the expression of IL-1?,IL-8 and TNF-?mRNA.Different concentration of B.subtilis peptidoglycan could significantly improve the anti-oxidative activity,and increase the mRNA levels of anti-inflammation cytokine,and decrease the pro-inflammation cytokine,and inhibit the inflammatory response of the carp IECs induced by?-conglycinin.