Objective To study a simple and practical method of isolation, culture and identification of hepatic oval cells from adult rat. Methods Wistar adult rats were fed by 2-acetaminofluorere （AAF） and were stimulated by partial hepatectomy to activate the proliferation of hepatic oval cells. After operation 12 days, the livers were resected for isolating oval cells. Hepatic tissue was digested by 0.10% collagenase Ⅳ and the obtained heterogeneous liver cells were then isolated and purified by density gradient centrifugation. The expressions of albumin and CK19 mRNA in hepatic oval cells were analyzed by immuno-fluorescence and RT-PCR. Results The survival rate of the newly isolated oval cells was more than 90%. The hepatic stem cells were shown by immuno-fluorescence of stem cell’s antigen c-kit. The expressions of mRNA CK19 and albumin of the oval cell were also detected by PCR. The proliferation activity of the newly isolated oval cells was significantly high and they could be induced to differentiate into both hepatic and bile ductal cells by some growth factors. Conclusion The successful development of the simple and feasible isolation and purification procedure as well as the identification method for hepatic oval cells may provide a fundamental for further studies about bionomics of the hepatic stem cell and the relation between stem cells and hepatic carcinoma.
Objective To explore the proper dosage of establishment of stable hepatic oval cells （HOC） prolif-eration model by using 2-acetaminofluorene （2-AAF） combined with two-third partial hepatectomy （2/3 PH） surgery， and to explore isolated and cultured method of HOC in vitro. Methods The 174 Wistar rats were randomly divided into 4 experimental groups （each group enrolled 30 rats）， saline group （n=30）， and untreated group （n=24）. Rats of 4 experi-mental groups were underwent gavage of 5， 10， 15， and 20 mg/（kg ? d） 2-AAF， corresponding to the groups from No.1 to No.4 group. Rats of saline group received saline gavage and rats of untreated group didn’t received any treatment. A standard 2/3 PH surgery was performed on the 5th day after gavage， then the same gavage method was still administrated as preoperation untill rats were sacrificed. The liver tissues of 6 selected rats were adopted and identified by HE staining and immunohistochemical staining on 4， 8， 12， and 16 days after PH for observation of the proliferation of HOC in every group， on 4 days， levels of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） were tested in addition. HOC were isolated and purified by collagenase perfusion method and percoll gradient centrifugation. Results The surv-ival rates of untreated group，saline group，No.1 group，No.2 group，No.3 group，and No.4 group were 100% （24/24），93% （28/30），93% （28/30），90% （27/30），90% （27/30），and 80% （24/30） respectively. Compared with the saline group and untreated group， the levels of serum ALT and AST increased significantly in No.2， No.3， and No.4 group on the 4th day after PH （P＜0.05）. The results of HE staining showed that No.2， No.3， and No.4 group were observed visibly different level of damage at liver tissue， and the proliferation level of HOC were most obviously in No.3 and No.4 group. The results of immunohistochemical staining revealed that proliferation cells were positively expressed oval cell marker-6 （OV-6）. The number of OV-6 positive cells were increased significantly with the increase of dosage of 2-AAF between 4 days and 12 days after operation， and proliferation levels were related with dosages of 2-AAF （P＜0.05）. In all cultured cells， 80% of cells were OV-6 positive cells after isolation and culture by using collagenase perfusion method and percoll gradient centrifugation. Conclusions The methods of gavage of 2-AAF at 15 mg/（kg ? d） combined with 2/3 PH surgery can establish the HOC proliferation model on the 12th day， as well as the rats have lower mortality and better tolerance， especially. The collagenase perfusion method and percoll gradient centrifugation can be used to isolate HOC effectively.
Objective To construct gene-modified hepatic stem cells (WB-F344 cells), which have rat IL-13 gene and can secrete the recombinant rat IL-13 cytokine in the cells. Methods Firstly, the rat IL-13 sequences were synthesized. Then the sequences were amplificated in bacterium coli after recombinated with pWPXL-MOD plasmid. After PCR and sequence identification, the positive clones were packaged into lentivirus. After detecting the virus titer, the WB-F344 cells with constructed lentivirus vector with rat IL-13 gene were cultured, then the valid targets (expression level of the IL-13) were detected by real time-PCR and Western blot in cultured WB-F344 cells on 5 days. Results The valid DNA of rat IL-13 was recombinated and packaged in lentivirus vector. The recombinant gene sequence was correct by checking with gene sequence test. Then the recombinant was introducted into the WB-F344 cells cultures. The best multiplicity of infection (MOI) value for effective transfection was 5. IL-13 had been detected on day 5 after transfection by checking with real-time PCR and Western blot. Conclusion The recombinant rat IL-13 gene with lentivirus vector is constructed and gene-modified WB-F344 cells are cultured successfully, which can be used in next animal experiment.
Objective To investigate the clinical outlook of hepatic stem cells and its relations with liver cancer. Methods The literatures of recent years on the studies of hepatic stem cells were reviewed. Results Liver cancer may consist of cells of various differentiation grades and it may result from the perodifferentiated hepatic stem cells or abnormal differentiated cells. Conclusion The hypothesis of hepatic stem cells has been identified extensively. Further study maybe helpful for revealing the origin, carcinogenesis of hepatic cancer, and may also be useful for the understanding of the mechanism of metastasis.
ObjectiveTo introduce the general situation about oval cells and the advance in research on relation between the hepatic oval cells and hepatocellular carcinoma (HCC). MethodRelevant literatures in recent years about oval cells in hepatocellular carcinoma were collected and analyzed. ResultsHepatic oval cells are progenies of the hepatic stem cells that are thought to reside in the terminal branches of the biliary tree, termed the canals of Hering.After severe liver injury resulting in hepatocyte and cholangiocyte necrosis/apoptosis, the dual-potential oval cells will proliferate and differentiate into hepatocytes or cholangiocytes to replace the respective lost cell types.Recent studies have found many new oval cell surface markers, and promoted the recognition of oval cells.The level of oval cells proliferation is positively correlated with the malignant and inflammatory level of chronic liver diseases.More importantly, oval cells is involved in the occurrence, development, recurrence, and metastasis of liver cancer, and closely related to the prognosis of HCC. ConclusionAn improved understanding of the biological behavior of hepatic oval cells may lead to the development of novel diagnosis, treatment regimens, and prevention for hepatocellular carcinoma.