The Study On The Role Of Toll-Like Receptor 2, 4 In Acute Edematous Pancreatitis

[Objective]The objective in this study includes: ㏕o investigate the expression and distribution of TLR2,TLR4 in rat pancreas. (D To explore if there are some TLR2,TLR4 distribution and expression changes occur in rat pancreas, intestinal mucosa during the process of acute edematous pancreatitis hence foundation provided for further research of what role the innate immune system plays in the pathogenesis of acute pancreatitis.[Methods] (D The model of rat acute edematous pancreatitis: Randomized male/female Wistar rats weighing 250-300g were divided into 4 groups: Group A as the normal controled 4-hour, and Group B as the 12-hour group,_while Group C as the acute edematous pancreatitis 4-hour, and Group D as_the 12-hour group. The models of rat acute edematous pancreatitis were_induced by subcutaneous injection of caerulein, while the control group received the same amount of injection of sterile normal saline instead. (2) Reverse Transcreptase-Polymerase Chain (RT-PCR) was applied to detect the expression of TLR2-mRNA,TLR4-mRNA. The products were identified by electrophoreisis in 1.3% agarose gels and the images were processed through UVI software.(3) Immunohistochemistry (IHC) : According to the principle of specific antigen-antibody combination, TLR2,TLR4 protein of tissues (pancreas, intestinal mucosa) were detected by specific anti-rat TLR2,TLR4 antibody respectively with immunohistochemistry technique. (4) The serum levels of TNFa,IL-l ,IL-6 were detected by ELISA, the serum amylase is also be measured.[Results] (1) RT-PCR: TLR2,TLR4 cDNA fragment were detected from total RNA of the rat pancreas. TLR2,TLR4 RNA were stronger expressed in acute edematous pancreatitis groups. (2) Immunohistochemistry revealed TLR2,TLR4 protein mainly distributed in the epithelium of the pancreatic duct, vascular endothelium. The intestinal mucosa also expressed TLR2 and TLR4. Stronger signals could be found in acute edematous pancreatitis groups. (3) The serum levels of amylase,TNFa,IL-l ,IL-6 were un-regulated in the experimental groups with notable statistic difference (P<0.05) compared with the control groups.[Conclusions] (1) The expression of TLR2,TLR4 definitely exists in rat pancreas, suggesting relationship between the innate immune system TLRs and pathophysiology of pancreas. TLR2,TLR4 protein mainly distributed in the epithelium of the pancreatic duct, pancreatic vascularendothelium and intestinal mucosa. (2) The expression levels of TLR2,TLR4 were growing higher in the experimental groups with the aggravation of inflammation. With reference to the serum levels of amylase,TNFa,IL-l ,IL-6, we conclude the expression levels of TLR2,TLR4 are positive inflammation-dependent. TLR2,TLR4 might win an important role in the process of inflammatory expansion in acute pancreatitis.