Association Study Of TRP Ion Channels With The Production Of Inflammatory Factors In Chicken Gut

The TRP（transient receptor potential）ion channel family was first discovered in Drosophila,and although research on them started late,their expression on neuronal and immune cells makes them an attractive drug target in inflammatory diseases.TRP channels that have been probed in the poultry intestine include: TRPA1,TRPM8,TRPV1,TRPV2,TRPV3,TRPV4.This study useds acute LPS（lipopolysaccharide）exposure and control of TRP ion channel opening and closing to reveal the link between TRP ion channels and inflammatory factor production in the poultry intestine by investigating TRP ion channel expression and inflammatory factor production.Developmental changes in TRP ion channel expression and inflammatory factor secretion in the chicken intestine.In this study,samples were taken from the duodenum,jejunum and ileum of broilers at 1 day of age,at weekly intervals,to detect the m RNA abundance of TRP ion channels and inflammatory cytokines.The results revealed that chicken intestinal TRP ion channels and inflammatory cytokines had higher gene expression abundance in the early or later stages of chicken growth.In the duodenum,LPS promoted TRPV2（14 d）,TRPM8（28 d）,and IFN-γ（14 d）gene expression（P < 0.05）and inhibited TRPV3（14 d）,TRPA1（1 d）,and IFN-γ（1 d,21 d）gene expression（P < 0.05）;in the jejunum,LPS upregulated TRPV1（56 d）,TRPV2（56 d）,TRPV3（14 d,56 d）,TRPV4（14 d,56 d）,TRPM8（7 d,56 d）,IL-6（7 d）and TNF-α（1 d,42 d）m RNA abundance（P < 0.05）and significantly downregulated TRPM8（28 d）,IFN-γ（21 d）m RNA abundance（P < 0.05）.In the ileum,LPS upregulated the m RNA abundance of TRPA1（28 d）,TRPM8（35 d）,TRPV1（28 d,56 d）,TRPV2（28 d,56 d）,TRPV3（14 d,28 d）,TRPV4（14 d,28 d,56 d）,IL-6（28 d）and TNF-α（42 d）（P < 0.05）,meanwhile down-regulated the m RNA abundance of TRPA1（49 d,56 d）,IFN-γ（21 d,56 d）and TNF-α（56 d）（P < 0.05）.The above results indicated that the gene expression of TRP ion channels and inflammatory cytokines in chickens varied according to age and intestinal sites,and the age at which the m RNA abundance of TRP ion channels and inflammatory cytokines changed significantly in the same intestinal sites was basically the same under normal physiological state and immune stress conditions,especially in the duodenum and ileum.Effect of opening and closing of TRP ion channel on NF-κB/MAPK inflammatory signaling pathway in chicken intestine.Isolation and incubation of chicken ileal explants,treatment with LPS,TRP non-specific activator（Carvacrol）or TRP non-specific inhibitor（Ruthenium Red and Neferine）and detection of gene expression of TRP ion channels,inflammatory cytokines NF-κB and MAPK inflammatory signalling pathways.It was found that the m RNA abundance of TRPV1,TRPV3,TRPV4,IL-1β,IL-2,IL-4,TLR-4,Myd88,IKK,IκBβ,TGFβ,JNK,AP-1-JUN increased significantly（P < 0.05）after the addition of carvacrol to LPS exposure,with TRPV1,TRPV3,TRPV4,IL-2,and IL-4 showed a dose-dependent response.The addition of ruthenium red to LPS exposure resulted in a significant decrease in m RNA abundance of TRPV2,TRPA1,IFN-γand JNK（P < 0.05）and a significant increase in gene expression of TGFβ,IKK,Myd88,IκBα,NF-κB and AP-1-FOS（P < 0.05）.The m RNA abundance of TRPA1,TNF-α and NF-κB was significantly decreased（P < 0.05）and the gene expression of IκBβ was significantly increased（P < 0.05）after the addition of NF on top of LPS exposure.Taken together,treatment of chicken intestine with nonspecific activators or antagonists that regulate TRP ion channel opening and closing resulted in corresponding upor down-regulation of gene expression of multiple TRP ion channels and further increase or decrease in m RNA abundance of inflammatory cytokines as well as NF-κB and MAPK pathway inflammatory signaling molecules on the basis of LPS exposure,revealing that TRP ion channels contribute to chicken intestinal inflammatory mediating role of TRP ion channels on chicken intestinal inflammatory cytokine production.