Abstract: Objective To explore the role of Caspase signaling pathway in regulating hepatocytes of the rat regenerating liver. Methods A total of 114 adult rats were randomly divided into 19 groups which consist of 9 partial hepatectomy groups,9 sham operation groups and 1 normal control group.Hepatocytes were separated with a conventional two-step perfusion method and the percoll density gradient centrifugation at 10 different time points following operation.Rat Genome 230 2.0 array was used to detect expression changes of Caspase signaling pathway-related genes in rat liver regeneration (LR) .Fluorescence quantitative PCR (FQ-PCR) was used to confirm reliability of microarray results.Bioinformatics and systems biology methods were used to analyze the role of Caspase signaling pathway in rat LR. Results Literatures showed that 38 paths and 123 genes were involved in Caspase signaling pathway.Of them,106 genes were included in Rat Genome 230 2.0 array,and it was found that 38 genes were related to hepatocytes of rat regenerating liver.A total of 21 paths from Caspase signaling pathway,including paths 1,2 and 11 at 30 hours,paths 27,29 and 31 at 70 hours,paths 15 and 16 at 2 hours and 30 hours,paths 3 and 4 at 30 hours and 72 hours after partial hepatectomy (PH),were found to inhibit hepatocyte apoptosis while 14 paths,such path 14 at 2 hours,path 34 at 6 hours,path 7 at 30 hours,path 13 at 2 hours and 30 hours,path 36 at 36 hours and 30 hours after PH,were involved in promoting hepatocyte apoptosis during rat LR. Conclusion Thirty-eight genes and 15 paths of Caspase signaling pathway may regulate apoptosis of hepatocytes in rat LR.

Key words: Rat liver regeneration, Caspase signaling pathway, Genome 230 2.0 array, Fluorescence quantitative PCR, Rat