Role of XBP1 signal transduction pathway in the ischemia/reperfusion injury of graft liver in rats / 中华器官移植杂志

ABSTRACT

Objective To explore the regulation mechanism of X box binding protein 1 (XBP1)signal transduction pathway for TNF-α and effective approach in ischemia/reperfusion (I/R) injury of liver transplantation for short hairpin RNA (shRNA) interference used to gene therapy in liver graft.Methods Male Sprague-Dawley rats were divided into three groups the cold ischemia transfection group (CIT), the in vivo transfection group (IVT) and the control group. Experiments of orthotopic liver transplantation were performed by two cuff method. The rats in CIT were perfused with XBP1-shRNA plasmid (pSIXBP1) during cold ischemia phase, those in IVT received the equivalent volume (2 ml) of pSIIRAK 4 after portal vein inoculation, and those in the control group were not subjected to any treatment. Rats were killed at 60 or 180 min after restoring reperfusion of hepatic portal vein.Histopathological damage degree of graft liver was observed by light microscope. The expression levels of XBP1 gene and protein were detected by RT-PCR and Western blotting. The activities of NF-κB and the serum TNF-α level were detected by ELISA. Results All the indexes including the degree of histopathological damage, the expression levels of XBP1 mRNA and protein and the TNF-α level were significantly decreased in CIT as compared with IVT and control group (P＜0. 05). However,there was no significant difference in NF-κB activity among the three groups (P＞0. 05). Conclusion The role of XBP1 pathway in TNF-α gene regulation and that of NF-κB pathway in rat liver I/R injury are two relatively independent aspects, and the depression of XBP1 expression with XBP1 shRNA through portal vein perfusion during cold ischemia phase could effectively alleviate graft hepatic I/R