The Distribution And Expression Of TWEAK/Fn14 In Intestine Of Different Ages Of Piglets

Tumor necrosis factor-like weak inducer of apoptosis(TWEAK)plays an important role in maintaining gastrointestinal immune balance and mediating the intestinal inflammatory response by binding to its receptor Fibroblast growth factor-inducible14(Fn14).The diarrhea of piglets caused by various causes is mainly characterized by intestinal inflammatory disease.However,the expression pattern of TWEAK/Fn14 in gastrointestinal tract of piglets and its biological function in intestinal immunoregulation has not been fully investigated.The aim of this study was to investigate the distribution and expression of TWEAK and Fn14 in intestine of piglets in responses to ages and LPS stimulation.This study may shed light on the regulation of TWEAK-Fn14 pathway in immunocompromised and stable immunoregulatory transition in piglets under normal physiological conditions and inflammatory diseases.The small intestine,ileum,rectum and colon tissues of piglets at 0,7,33 days and 55 days of age were collected and the expression pattern of TWEAK,Fn14 and Occludin were detected by qRT-PCR and Western Blot.The results of the study were as follows:1.The results of fluorescence quantitative RT-PCR showed that TWEAK and Fn14 m RNA could be detected in intestinal tracts of healthy pigs at indicated ages.The expression of TWEAK mRNA was increased rapidly and peaked at 7 days,and the expression of Fn14 m RNA increased slightly between 7-55 days.The expression of TWEAK mRNA in LPS stimulated intestine was significantly lower than that in normal age matched control group while the expression of Fn14 mRNA was significantly increased after LPS stimulation.2.Western Blot analysis showed that low levels of TWEAK expression were detected in intestinal tissues of healthy piglets at 0 days,and a significant high levels of TWEAK expression were observed between 7-55 days.Interestingly,The highest level of TWEAK expression in rectal tissue at 7 days and quickly reduced after that were detected.The expression levels of Fn14 in the intestine of healthy pigs were weak at detected ages,in particularly at 0 days.In addition,the expression levels of Occludin in the small intestine was the lowest at 0-7 days,then increased gradually and reached peak 55 days.Occludin expression in ileal tissue was higher in all detected ages.In the colon and rectal tissues,Occludin had the highest level of expression at 0 days,and then all showed a decreased trend.After treatment with LPS,the expression of TWEAK and Occludin was significantly lowerthan that of normal age matched control group,while Fn14 expression was significantly increased.In summary,this study investigated the dynamic expression of TWEAK,Fn14 and Occludin in the intestine tract of healthy pigs at different ages and the effect of LPS stimulation on its expression.Effects of LPS on TWEAK,Fn14 and Occludin expression in piglets intestine suggests that TWEAK-Fn14 pathway may play an important regulatory role in intestinal inflammatory changes in piglets.