The Role Of NOD1 Receptor In The Activation Of NF-κB And Proinflammatory Cytokines During SARA

Dairy animals are frequently nurtured high grain diets to meet the energy demand of high milk production or simply due to a shortage of forages at times.In the end,ruminal acidosis,especially sub acute ruminal acidosis（SARA）occurs.SARA is well known to trigger the inflammatory response that is probably caused by the translocation of Lipopolysaccharides（LPS）from the gastrointestinal tract into the bloodstream.The objective of this study was to investigate the possible mechanism involved in the alteration of gene expression in the rumen of dairy cows and lactating goats due to increases of circulating LPS in the rumen and translocation of LPS into blood stream because of high concentrate diet induced SARA and to investigate the role of sodium butyrate（Buffer）whether it mitigate the expression of inflammatory genes in the mammary gland tissue of lactating goats.To understand the relationship between high grain diet and ruminal inflammation during SARA,twelve healthy Holstein cows were randomly distributed into two groups:High concentrate diet（HC）group and Low Concentrate diet（LC）group.The HC group was fed a high-concentrate diet（6:4 concentrate/roughage ratio）whereas the LC group was fed low concentrate diet（4:6 concentrate/forage ratio）respectively for the 18 weeks of experimental period.Rumen fistula was installed in all the dairy cows at 16^th weekof the experiment,and slaughtered at the end of experimental period.Here we found that HC group exhibited significant increase in LPS concentration in the rumen fluid as compare to the LC group.The Radio immune assay was performed,which has revealed that the expressions of pro-inflammatory genes in the peripheral blood were significantly increased in HC group as compared to LC group.Rumen tissue samples were used to perform Real-time,the mRNA expression level of innate immune genes NOD1 and NF-κB were significantly elevated in HC group as compared to the LC group,followed by Proinflammatory genes（IL-1β,IL-6 and TNF-α）.The high expression of pro-inflammatory genes indicated inflammation.However,this increase in the expressions of pro-inflammatory genes was mediated by NF-κB induced through NOD1.Eighteen mid-lactating goats were randomly divided into three groups:High concentrate diet（HC）group,Comprehensive regulatory diet（CC）group and Low Concentrate diet（LC）group.Except（LC）group both the groups were fed a high-concentrate diet（6:4 concentrate/roughage ratio）,but CC group diet was palletized with mixed buffer agents for the 20 weeks of experimental period.Rumen fistula was installed in all the dairy goats at 14^th week of the experiment,and slaughtered at 24^th week.Taking together,we found that the concentration of LPS in the rumen fluid was significantly increased in HC group compared to the CC and LC groups.We performed radio Immunoassay,which has revealed the expression of pro-inflammatory genes in the peripheral blood were significantly up regulated in HC group as compared to CC and LC groups.Rumen tissue samples were used to perform Real-time,which has revealed the mRNA expression level of innate immune genes NOD1,IKβ and NF-κB were significantly elevated in HC group as compared with the CC and LC groups and the expressions of Proinflammatory cytokines（IL-1β,IL-6 and TNF-α）were up regulated in HC group compared to the CC and LC group,which is the evidence of inflammation.Meanwhile,this increase in the expressions of pro-inflammatory genes was mediated by NF-κB induced via NOD1.To investigate the relationship between high concentrate diet and High concentrate diet with butyrate sodium（buffer）in attenuating inflammation during SARA,Twelve mid-lactating goats were randomly divided into two groups 6 goats in each group:High concentrate diet（HC）as a control group and High concentrate diet with buffer（HCB）as a treatment group.Both the groups were fed a high-concentrate diet（6:4 concentrate/roughage ratio）,but HCB group diet was palletized with the surplus of mixed buffer agents for the 20 weeks of experimental period.Rumen fistula was installed in all the lactating goats at 14^th week of the experiment,and slaughtered at 24^th week.The pH of rumen fluid was measured through a pH meter and the concentration of LPS（Lipopolysaccharides）in peripheral blood was determined.Here we found that the LPS concentration was significantly increased in HC group while HCB group remained normal.The radio Immunoassay showed that the expressions of pro-inflammatory genes in the lacteal blood were significantly increased in HC group as compared to the HCB group.Mammary gland tissue samples were used to quantify the mRNA expression level of innate immune genes NOD1,IKβ and NF-κB were significantly elevated in HC group as compared to HCB group,similarity showed by Proinflammatory genes（IL-1β,IL-6 and TNF-α）.We have demonstrated for the first time that butyrate sodium（Buffer）inhibits inflammatory responses during SARA by inhibition of NF-κB activation in the mammary gland tissues of lactating goats.In conclusion,the present results specify innovative evidence for the critical role of NOD1 in the rumen wall tissues of dairy cows and lactating goats during SARA.By contributing significantly to induce alterations associated at least in part with activation of NF-κB signaling pathway（pro-inflammatory cytokines）.Our findings have further confirmed the engagement of NOD1 mediated immune response in Ruminal infarction,and its activation mitigated by Buffer in the mammary gland tissue of lactating goats during SARA.