Preconditioning effects on expression of proto-oncogenes c-fos and c-jun after hepatic ischemia/reperfusion in rats

BACKGROUND: Ischemia/reperfusion is the main cause of hepatic damage in liver transplantation. Immediate early genes (IEGs) encode proteins can regulate expression of cellular response genes after injury, and is associated with tissue repair and cell apoptosis. The purpose of this re- search was to investigate the effects of preconditioning on expression of immediate early genes c-fos and c-jun follow- ing hepatic ischemia/reperfusion (IR) and its roles in cellu- lar regeneration and apoptosis. METHODS: Ninety-six Wistar rats were randomly divided into IR group and hepatic ischemic preconditioning (IPC) group, and each group was further divided into eight sub- groups (n =6). The model of partial liver ischemia/reper- fusion was used. The rats were subjected to 60-minute liver ischemia, preceded by 10-minute preconditioning. After 0-, 0.5-, 1-, 2-, 4-, 8-, 12-, 24-hour reperfusion, the se- rum and liver tissue in each group were collected to detect the level of serum ALT/AST, liver histopathology, expres- sion of c-fos, and c-jun mRNA. Flow cytometer was used to detect Ki67 and Sub-G1 as the quantity indicators of cell regeneration and apoptosis respectively. RESULTS: Compared with IR group, IPC group showed a significantly lower ALT/AST level in 0. 5-hour sub-group to 8-hour sub-group (P<0.05). Ki67 elevated significantly at 0.5, 1, 2 hours, but decreased significantly at 24 hours ( P < 0 . 05). Ap index decreased significantly after 1-hour reperfusion(P<0.05). Expressions of c-fos and c-jun mR- NA were low, especially c-jun at 0.5, 1 and 2 hours after reperfusion. CONCLUSION: Ischemic preconditioning can protect liver cells against ischemia/reperfusion injury, and this protec- tive effect may be related to influence transcription levels of c-fos and c-jun.