Screening And Initial Analysis Of The Relevant Albumens Of Regeneration Of Hepatocyte After Partial Hepatectomy In Rats

Liver is the most important organ in animals, it has the function of Metabolism, detoxification, bile secretion, swallow, defense and other physiological and biochemical function. When Liver failures, there is no effective alternative means, but liver has the great capacity of regeneration. Higgins has established the animal model of partial hepatectomy since 1931, and the studies in liver regeneration have great development. But most researches are focused on single protein, gene or signal pathway, because of the limit of research technology. In recent years the technology of proteomics has great development, which provides a good technological platform for research of liver regeneration on the whole. So we designed the experiment to study the proteomical change of hepatocyte in the early stage after partial hepatectomy.Objective:We used the rat 70% hepatectomy model to research the proteomics of the hepatocyte in the early stage (0h, 6h, 24h) after partial hepatectomy. We screened and appraised the different proteins related to the hepatocyte proliferation, got the information of the proteins through Internet. We hoped to study the molecular mechanism of the liver regeneration on the whole.Methods:We chose 18 male SD rats (weight 190-210g), randomly divided into three groups, 6h group, 24h group and 0h group, each group had 6 rats, made the rat 70% hepatectomy model with the method introduced by Goss. 6h group was the hepatocyte isolated from the rat liver in six hours after partial hepatectomy, 24h group was the hepatocyte isolated from the rat liver in 24 hours after partial hepatectomy, and the 0h group was the hepatocyte isolated from the rat liver immediately after partial hepatectomy. We extracted total proteins with cell lysate, used two-dimensional electrophoresis to separate the total proteins, detected the proteins in the gel with silver staining compatible mass spectrum, analyzed the gel pictures of the three groups with the imagermaster 2D software 2002.2 analysis software, got the PMF of the proteins with MALDI-TOF. Then we got the information of the proteins from the Swiss-prot data base and the relevant documents of the proteins from Pubmed data base.Result:1. We found 42 proteins which changed obviously in the early stage after partial hepatectomy through comparison of the proteomics of hepatocytes in the three groups (0h group, 6h group, 24h group). According to the documents related to the proteins, there were 9 proteins related to liver metabolism(Fatty acid-binding protein, etc.), 11 proteins related to synthesis and transcription of DNA and synthesis of proteins (Centromere protein S,Centromere protein M,Proteasome subunit beta type 7 precursor,etc.), 17 proteins related to regulation of cell proliferation (Histone deacetylase,Amyloid protein-binding protein 1,Developmentally-regulated GTP-binding protein,etc.), and 5 proteins had the other function.2. There were three main patterns of the change of those proteins in the early stage after partial hepatectomy: sustainedly increasing pattern, decreasing then increasing pattern and increasing then decreasing pattern. There were 14 proteins whose expression were both higher in time point 6h and 24h, and the changing pattern was mainly of the proteins related to regulation of cell proliferation, such as protein developmentally-regulated GTP-binding protein 2, Mitogen-activated protein kinase 3, etc. There were 13 proteins whose expression decreased in time point 6h, then increased in time point 24h, such as protein Proteasome subunit beta type 7 precursor, etc. There were 7 proteins whose expression increased in time poin 6h, then decreased in time point 24h, such as protein proteasome subunit beta type 7 precursor, transmembrane protein 115, etc. And the changed patten which was like a wave (increasing/decreasing and decreasing/increasing) was mainly of the proteins related to synthesis and transcription of DNA and synthesis of proteins.Conclusion:1. Proteins related to the regulation of the cell proliferation like Amyloid protein-binding protein 1, Developmentally-regulated GTP-binding protein ect. change obviously, which show sustainedly increasing pattern. Maybe they regulate liver regeneration through different signal pathway.2. Proteins related to synthesis and transcription of DNA show significant fluctuation, some show increasing/decreasing pattern like centromere protein, some show decreasing/ increasing pattern like histone deacetylase, which indicate they have different functions in the process of regeneration.3. Proteins related to the lipid metabolism changes obviously after hepatectomy, which show different patterns. And which indicate these proteins have complex functions. In our experiment, we have studied the exchange of the proteomics of hapatocyte in the early stage (0h, 6h, 24h) after partial hepatectomy. But we have not authenticated the proteins in our result within immunological methods or tested the expressions of the genes of the proteins, because of the limit of our time, but we would do all of those to finish the research of the liver regeneration on the whole in the future. .