Objective To investigate the stable, high effective and low toxicity gene transfer vectors’ basics in research and clinical application.Methods Current status of hepatocytedirected gene transfer vectors were reviewed by history document and contemporary experimental advances analysis.Results Viral and nonviral vector systems could both transduce target genes to liver effectively with various transduction rates based on their corresponding biological characteristics.Conclusion Hepatocyte is the effective target for gene therapy of liverrelated genetic, neoplastic and infectious diseases, although the security needs to be further evaluated.
【Abstract】Objective To investigate the injury of calcium on the liver. Methods By using collagenase-containing solution to perfuse the rat livers, the rat liver suspension with different viability was prepared, preserved hypothermically, and the cytosolic calcium comcentration was detected with Fura2/AM. Results ① The concentration of cytosolic calcium after 2-hour storage: Experiment group 1(viability 5%) (1055.0±30.79) nmol/L, experiment group 2(viability 10%) (853.0±20.42) nmol/L, experiment group 3(viability 30%) (616.0±13.20) nmol/L, experiment group 4(viability 50%) (562.0 ±26.06) nmol/L, experiment group 5(viability 70%-80%) (318.0±13.01) nmol/L, experiment group 6(viability 90%) (114.6±6.11) nmol/L. ②The concentration of cytosolic calcium after 24hour storage: Experiment group A(viability 10%) (1704.0±70.11) nmol/L, experiment group B(viability 50%) (1125.0±23.22) nmol/L. The results showed that the lower was the viability, the higher was the cytosolic calcium concentration.With the same viability the cytosolic calcium concentration elevated more than two times higher than the original concentration with the time lengthened. Conclusion Calcium overload is one of the main factors which attribute to the ischemiareperfusion injury of the hepatocytes.
Objective To prepare chitosan microcarriers and to use it to cultivate rat primary hepatocytes. Methods The crosslinked chitosan microcarrier was prepared by the reaction of glutaraldehyde with chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Rat primary hepatocytes cultured on chitosan microcarrier were observed by using phase contrast microscope and scanning electron microscope. Results Chitosan microcarriers with good properties could be prepared by adjusting the concentration of chitosan solution and the quantity of glutaraldehyde. Rat hepatocytes cultured on chitosan microcarriers retained the spherical shape as they have in vivo. And albumin secretion can last over one week. The highest albumin secretion rate reached 26.7μg/24h/ml. Conclusion Chitosan microcarriers is a promising scaffold for hepatocyte attachment, which can be used in bioartificial liver support system.
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.
Objective To investigate the effects of human recombinant hepatocyte growth factor(rh-HGF) on the expression of c-Met in intima of allograft vessels after cardiac transplantation in rats. Methods Heterotopic heart transplantation were established in abdominal cavity with eighty Wistar rats and forty SD rats. Donors’ cardiac grafts from Wistar rats were transplanted to SD rats(allograft) or Wistar rats(isograft).Sixty recipient rats were divided into three groups, control group：20 Wistar rats were injected with normal saline 1ml/kg·d intraperitoneally after transplantation; cyclosporine A (CsA) group:20 SD rats were injected with CsA 5mg/kg·d intraperitoneally on operation day; rhHGF group:20 SD rats were injected with rh-HGF 500μg/kg·d and CsA 5mg/kg·d intraperitoneally on operation day. The cardiac grafts were harvested at the 15th day and 60th day after transplantation. The crosssection of vascular tissues were used for immunohistochemistrical staining of c-Met, and investigated the expression of c-Met messenger ribonucleic acid (mRNA ) in intima of allograft vessels by reverse transcriptionpolymerase chain reaction(RT-PCR). The pathologic changes of allograft coronary vessels were observed with histopathological method. Results The allograft coronary arteries showed minimal intimal thickening, the endothelium and internal elastic lamina remained almost intact in rh-HGF group after transplantation.The expression of c-Met and c-Met mRNA in intima of allograft vessels after transplantation in rhHGF group were significantly higher than those in CsA group and control group（expression of c-Met at 60d: 1.85±0.26 vs. 0.96±0.10, t=8.491,P=0.000;1.85±0.26 vs. 0.58±0.03, t=13.725,P=0.000; expression of c-Met mRNA at 60d: 192±0.22 vs. 0.88±0.07, t=11.940,P=0.000;1.92±0.22 vs. 0.42±0.02,t=19.206,P=0.000）. Conclusion rh-HGF may prevent the progression of cardiac allograft vasculopathy through upregulating the expression of c-Met to stimulate endothelial cell repair and growth.
【Abstract】 Objective To explore the new therapy for pulmonary fibrosis by observing the effects of insulin-like growth factor 1 ( IGF-1) treated mesenchymal stemcells ( MSCs) in rats with bleomycin-induced pulmonary fibrosis. Methods Bone marrowmesenchymal stemcells ( BMSCs) were harvested from6-week old male SD rats and cultured in vitro for the experiment. 48 SD rats were randomly divided into 4 groups, ie.a negative control group ( N) , a positive control group/bleomycin group ( B) , a MSCs grafting group ( M) ,and an IGF-1 treated MSCs grafting group ( I) . The rats in group B, M and I were intratracheally injected with bleomycin ( 1 mL,5 mg/kg) to induce pulmonary fibrosis. Group N were given saline as control. Group M/ I were injected the suspension of the CM-Dil labled-MSCs ( with no treatment/pre-incubated with IGF-1 for 48 hours) ( 0. 5mL,2 ×106 ) via the tail vein 2 days after injected bleomycin, and group B were injected with saline ( 0. 5 mL) simultaneously. The rats were sacrificed at 7,14,28 days after modeling. The histological changes of lung tissue were studied by HE and Masson’s trichrome staining. Hydroxyproline level in lung tissue was measured by digestion method. Frozen sections were made to observe the distribution of BMSCs in lung tissue, and the mRNA expression of hepatocyte growth factor ( HGF) was assayed by RTPCR.Results It was found that the red fluorescence of BMSCs existed in group M and I under the microscope and the integrated of optical density ( IOD) of group I was higher than that of group M at any time point. But the fluorescence was attenuated both in group M and group I until day 28. In the earlier period, the alveolitis in group B was more severe than that in the two cells-grafting groups in which group I was obviously milder. But there was no significant difference among group I, M and group N on day 28.Pulmonary fibrosis in group B, Mand I was significantly more severe than that in group N on day 14, but itwas milder in group M and I than that in group B on day 28. Otherwise, no difference existed between the two cells-grafting groups all the time. The content of hydroxyproline in group B was significantly higher than that in the other three groups all through the experiment, while there was on significant difference betweengroup I and group N fromthe beginning to the end. The value of group M was higher than those of group I and group N in the earlier period but decreased to the level of negative control group on day 28. Content of HGF mRNA in group Nand group I was maintained at a low level during the whole experiment process. The expression of HGF mRNA in group I was comparable to group M on day 7 and exceeded on day 14, the difference of which was more remarkable on day 28. Conclusions IGF-1 can enhance the migratory capacity of MSCs which may be a more effective treatment of lung disease. The mechanismmight be relatedto the increasing expression of HGF in MSCs.
Objective To investigate the immunological rejection after hepatocyte transplantation for acute liver failure （ALF） in mice．Methods The hepatocytes were isolated from pig，BALB/c and C57BL/6 mice livers were conducted and then transplanted into C57BL/6 mice．CCl4 was used to make ALF mice model．The experimental animals were randomly divided into three groups， including syngenic group，allogeneic group，and xenogenic group．The survival statuses of all the mice were recorded. The alteration of T lymphocyte subsets，immune globulin，and cytokine were determined．Results ①The survival ratio was 8/10，6/10， and 3/10 in the syngenic group， allogeneic group， and xenogenic group， respectively．The survival ratio in the syngenic group was significantly higher than that in the other two groups （P＜0.05）．②The CD4+ and CD8+ T cells of the peripheral blood in the syngenic group did not change significantly on week one after transplantation．The CD4+ T cells in the allogeneic group reached the peak on day 3 after hepatocyte transplantation （P＜0.05）， while CD8+ T cells did not change much in one week．The CD4+ and CD8+ T cells in the xenogenic group increased and reached the peak on day 3 after transplantation （P＜0.05）．③There were no significantly differences of IgM and IgG in the syngenic group among 0.5， 1， and 3 d after transplantation. IgM of the allogeneic group and xenogenic group reached the peak on day 1 （P＜0.05） and IgG reached the peak on day 3 （P＜0.05） after transplantation．④The concentrations of IFN-γ， TNF-ɑ， and IL-2 in the allogeneic group and xenogenic group were significantly higher than those in the syngenic group （P＜0.05）．The concentration of IL-6 of the xenogenic group was higher than that of the other two groups （P＜0.05）. Conclusions CD4+ and CD8+ T cells play an important role in immune response to both allogeneic and xenogenic hepatocyte transplantation， as well as induce humoral immune response early after hepatocyte transplantation．
Objective To study hepatocyte growth factor (HGF) and its receptor (c-met) expressions in human colorectal cancer and non-neoplasm colorectal mucosa, and the relationship with tumor angiogenesis. Methods Tissue microarrays (TMAs) were made up of 80 cases of colorectal cancer and 80 cases of nonneoplasm colorectal mucosa. The expressions of HGF and c-met were detected by immunohistochemistry (SP). CD105 was used as a marker to account microvessel density (MVD) in tumor tissue. Results HGF was over expressed in 48 cases and c-met was over expressed in 63 cases of colorectal cancer tissue, and the correlation between HGF and c-met positive expression was significant (r=0.231, Plt;0.05). The high expression rate of HGF and cmet in colorectal cancer were significantly higher than that in non-neoplasm colorectal mucosa (χ2=35.387, Plt;0.05; χ2=59.854, Plt;0.05) of colorectal cancer. The overexpression of HGF was correlated with lymph node metastasis (χ2=4.743, Plt;0.05) and TNM staging (χ2=5.576, Plt;0.05). The overexpression of c-met was correlated with differentiation (χ2=15.767, Plt;0.05) and lymph node metastasis (χ2=5.765, Plt;0.05) of colorectal cancer. MVD was different between overexpression and lowexpression colorectal cancer tissues of HGF and cmet (t=2.150, Plt;0.05; t=2.052, Plt;0.05). There was statistical correlation between HGF and cmet overexpression (r=0.259, Plt;0.05). The overexpressions of HGF and cmet were correlated with lymph metastasis in moderate differentiation cancer (χ2=13.154, Plt;0.05; χ2=5.371, Plt;0.05). Conclusions The overexpressions of HGF and c-met in colorectal cancer may be related with tumor angiogenesis. Detecting the expressions of HGF and c-met is valuable to estimate the biological character of colorectal cancer.
Objective To establ ish a new induction method from human embryonic stem cells (hESCs) differentiating into hepatocyte-l ike cells using an adherent culture system with single-step induction. Methods Undifferentiated hESCs were cultured on Matrigel-coated culture plates for 4 days, hepatic differentiation was initiated at 60%-70% confluence by adding Activin A for 5 days. Then the induction medium was replaced by hepatocyte induction medium (HIM) supplemented with fibroblast growth factor 1 (FGF-1) and bone morphogenetic protein 4 (BMP-4) for another 6 days. Finally, the cells were treated with HIM adding hepatocyte growth factor (HGF) and Oncostatin M (OSM) for 5-7 days. The characteristics of differentiated cells were determined by morphology, immunofluorescence staining, RT-PCR, and Periodicacid- Schiff (PAS) test. Results Differentiated cells treated with Activin A, FGF-1, BMP-4, HGF, and OSM sequentially were morphologically larger and became spherical, oval or polygon. Some cells had 2 or 3 nuclei, suggesting that the cells have a hepatocyte-l ike morphology. Differentiated cells at first induction stage could be stained positive by SOX17 and Forkhead (FOX)A2 after induction by Activin A. Then they turned to be α fetoprotein (AFP) and α1 antitripsin positive cells at second induction stage after induction by FGF-1 and BMP-4. Finally, the differentiated cells treated with HGF and OSM showed PAS possitive for glycogen detection. The differentiated cells at various stages also expressed at early (SOX17, FOXA2, and GATA-4),middle (AFP, albumin, and cytokeratin 18), and mature (alcohol dehydrogenase 1C and Cytochrome P4501B1) stage hepatic genes, respectively. Conclusion Using a simple-step induction method and by suppl ied with cytokines consequently, hESCs can be induced to differentiate into hepatocyte-l ike cells. The differentiation method can provide seed cells for hepatic tissue engineering or cell-therapy.
Objective To introduce the studies on gene therapy for peripheral arterial disease(PAD) using plasmid DNA encoding human hepatocyte growth factor(HGF) gene. Methods Recent articles including preclinical and clinical studies were reviewed. Results Intramuscular injection of human HGF plasmid DNA into rat, rabbit, dog and diabetic hindlimb ischemic models, resulted in a significant increase in capillary density, blood flow and blood pressure. but no influence on tumor growth in mice. A clinical trial wasperformed in ischemic limbs of 6 critical limb ischemic patients, the result showed that no side effect caused by gene transfer was detected in all 6 patients.The pain scale and long diameter of ischemic ulcers were reduced. Conclusion Intramuscular injection of naked HGF plasmid DNA could be a safe and potential treatment for PAD.