Objective To solve the shortage of hepatocytes for l iver tissue engineering, to explore the possibil ity of prol iferation of rat bone marrow mesenchymal stem cells (BMSCs) and the feasibil ity of differentiation of BMSCs into hepatocyteswith a culture system containing cholestatic rat serum and hepatocyte growth factor (HGF) in vitro. Methods Myeloid cellsof femur and tibia were collected from the female healthy Wistar rats at the age of 6 weeks, the BMSCs were isolated, purified and identified. Normal and cholestatic rat serum were prepared from 40 healthy Wistar rats at the age of 12-14 weeks. The 3rd passage of BMSCs were harvested and added different cultures according to the following grouping: group A, DMEM plus 10%FBS; group B, hepatocyte growth medium (HGM) plus 5%FBS; group C, HGM plus 5% normal rat serum; group D, HGM plus 5% cholestatic rat serum; group E, HGM plus 5% cholestatic rat serum plus 25 μg/L HGF. The changes of cell morphology were observed, MTT assay was used to measure cell growth; the expression of alpha-fetoprotein (AFP) and cytokeratin 18 (CK18) were detected by immunocytochemistry; the glycogen deposit was examined by periodic acid-schiff (PAS) staining; and the urea content in culture supernatant was determined by glutamate dehydrogenase. Results Polygonal cells and binuclear cells were observed in groups D and E, while the shapes of cells in groups A, B, and C did not obviously change. The cell growth curve demonstrated that the speed of cells proliferation in group C was the fastest, the one in group B was the slowest; showing significant differences when compared with groups A, D, and E (P lt; 0.05). On the 7th day in groups D and E, the positive expressions of AFP and CK18 emerged, on the 14th day the positive expression of glycogen emerged. At the same period, the expression ratio was higherin group E than in group D (P lt; 0.05). The urea concentration increased gradually with induction time in groups D and E, the concentration was higher in group E than in group D (P lt; 0.05). No expressions of AFP, CK18, glycogen, and change of the urea concentration were observed in groups A, B, and C. Conclusion Normal rat serum can obviously promote the growth of BMSCs; cholestatic rat serum which promote the growth of BMSCs can induce to differentiate into hepatocyte; and a combination of cholestatic serum and HGF can increase the differentiation ratio.
【摘要】 目的 探討丙型肝炎病毒非結構蛋白NS4B對肝細胞內p53表達的影響，以及在肝癌發生中的作用與機制。 方法 設置空白對照組、空白載體組、轉染NS4B組、轉染p53組、共轉染NS4B及p53組。使用脂質體介導轉染法，轉染丙型肝炎病毒非結構蛋白重組質粒PCXN2-NS4B及突變型p53基因重組質粒pC53-CX22AN3進入Chang肝細胞內，并用G418篩選獲得穩定表達細胞。采用免疫細胞化學法檢測p53表達率。 結果 空白對照組無p53表達，空白載體組及轉染NS4B組呈弱陽性表達，轉染p53組及共轉染組呈陽性表達；轉染p53組、共轉染組分別與空白對照組、空白載體組及轉染NS4B組比較，差異均有統計學意義 （Plt;0.05）。 結論 NS4B可能抑制p53表達，也可能阻止其進入細胞核，但NS4B與突變型p53關系不明確。NS4B導致肝細胞異常增生，誘導肝癌發生可能不依賴p53的異常表達及突變。【Abstract】 Objective To investigate the effect of hepatitis C Virus on-structural protein 4B(HCV NS4B) on expression of p53 in hepatic cell, and to study the role and mechanism in development of hepatocellular carcinoma. Methods The experiment was divided into negative control, pure vector PCXN2, PCXN2-NS4B, PC53-cx22AN3, and co-transfection group. Recombinant plasmid PCXN2-NS4B and mutant p53 gene--PC53-cx22AN3, PC53-cx22AN3 with PCXN2-NS4B, blank vectors were transfected into Chang liver cell by liposome-mediated transfection respectively. Positive cells were screened by G418. The expression rate of p53 was measured by immunocytochemistry. Result No expression rate of p53 gene in control group was found, lower positive expression in group PCXN2 and PCXN2-NS4B. The expression of p53 gene in group PC53-CX22AN3 and co-transfection was ber than the others (Plt;0.005). Conclusion HCV-NS4B may inhibit the expression of p53 gene, and it may play a crucial role in inhibiting p53 transfered to hepatic cells nuclear. But it isn’t clear that the. HCV-NS4B can enhance the role of mutant p53 gene. It suggested that HCV-NS4B induce proliferation of hepatic cell not through regulating the expression of p53.