6.Establishment and comparison of DHPG and BMI induced epileptic discharge models
Journal of Shanghai Jiaotong University(Medical Science) 2009;29(6):668-672
Objective To develop models of epileptic discharge by activating group Ⅰ metabotropic glutamate receptors (mGluR) or by blocking gamma-aminobutyric acid (GABA) receptors on rat hippocampal slices. Methods Rat hippocampal slices were exposed to mGluR group Ⅰ specific agonist dihydroxyphenylglycine (DHPG) or to GABAA receptor antagonists bicuculline methiodide(BMI), and single pyramidal cell in the CA3 region of the slice was recorded by whole cell patch clamp technique. Results Exposure to DHPG or BMI resulted in the induction of spontaneously occurring epileptic discharge in the CA3 region of rat hippocampal slice, and there was no significant difference in the frequency of discharge between them(P>0.05). Conclusion Epileptic discharge can be generated in vitro in response to a loss of balance between excitatory and inhibitory influences.
7.Autophagy inhibition enhances radiosensitivity of esophageal squamous carcinoma Eca-109 cells
Chi LU ; Zhang LEI ; Qiong FENG ; Ting LU ; Hongda LU
Chinese Journal of Radiological Medicine and Protection 2015;35(3):165-170
Objective To investigate the role of autophagy in radiation-induced death process of human esophageal squamous carcinoma Eca-109 cells.Methods Esophageal carcinoma cell line Eca-109 was divided into 6 groups of control,5 mmol/L 3-Methyladenine treatment,10 mmol/L treatment,6 Gy irradiation,irradiation + 5 mmol/L drug,and irradiation + 10 mmol/L drug.Some cells were transferred with GFP-LC3 plasmid and the changes of autophagosome were obserred.After each treatment,the expression of autophagy marker LC3B was measured by Western Blot,cell viability was detected by MTT,morphological characteristics of apoptosis cells were stained with a fluorescein of Hoechst 33342 and the percentage of apoptotic cells and cell cycle distribution were measured by flow cytometry.Clonogenic survival were used to evaluate the cell radiosensitivity.Results Autophagy level was increased after radiation,and the LC3B Ⅱ expression and LC3B Ⅱ/LC3B Ⅰ ratio were significantly decreased by autophagy inhibitor 3-Methyladenine (F =25.64,P < 0.05).The number of autophagosome fluorescent foci were significantly increased in the GFP-LC3 transfected cells after radiation,but reduced by 3-Methyladenine (F =127.36,P < 0.05).Compared with radiation alone group,autophagy inhibition combined with radiation significantly decreased cell viability (F =129.54,P < 0.05) and colony formation,increased apoptosis and the percentage of G2/M-phase cells.Conclusions 3-Methyladenine enhances the radiosensitivity of esophageal squamous carcinoma Eca-109 cells,suggesting that inhibition of autophagy could be used as an adjuvant treatment of radiotherapy in esophageal squamous carcinoma.
9.Differentiation of human bone marrow-derived stem cells into insulin-producing cells in vitro and in vivo
Yan LU ; Yuan ZHANG ; Zuohua CHI
Chinese Journal of Pathophysiology 2009;25(4):774-780
AIM: To explore the possibility of differentiating functional insulin-producing cells from human BM-derived stem cells. METHODS: Mesenchymal stem cells were isolated from human bone marrow. Then these cells were induced with epidermal growth factor, β-mercaptoethanol and high concentration of glucose. The gene expression related to islet β cells was detected by RT-PCR. Insulin in the treated cells was examined by immunocytochemistry. In addition, the levels of insulin secretion and glucose-stimulated insulin release were examined by microparticle enzyme immunoassay. Finally, the induced cells were implanted into the right renal subcapsular space of diabetic mice. Blood glucose levels were monitored 16 d after implantation. The right kidneys of the treated mice were harvested for immunohistochemistry. RESULTS: The key genes related to pancreatic β cells had been confirmed to express by PCR and insulin was detected by immunocytochemistry in differentiated human BM-derived stem cells induced by high glucose, which responded to glucose challenge. Furthermore, implantation of the cells in renal subcapsular space was able to lower the glucose levels in hyperglycemic mice. After 16 days, the implanted cells were determined still to be insulin positive cells by immunohistochemistry. CONCLUSION: These results indicate human BM-derived stem cells are capable of differentiating into functional insulin-producing cells and may represent a pool of cells for the treatment of diabetes.
10.Differentiation of mesenchymal stem cells from umbilical cord blood into hepatocyte-like cells in the in vitro culture
Zuohua CHI ; Yuan ZHANG ; Yan LU
Chinese Journal of Organ Transplantation 2008;29(3):159-163
Objective To discuss the possibility of differentiation of mesenchymal stem cells(MSCs)from umbilical cord blood(UCB)into hepatocyte-like cells in the in vitro culture.Methods MSCs were isolated from UCB,cultured and passaged.The surface markers were examined by flow cytometry.When cells were cultured to the third passage,they were inoculated into a 6-well plate.A two-stage induction method was used:MSCs in the first phase were cultured in DMEM/F12 medium supplemented with dexamethasone(final concentration of 0.5 μmol/L,the same below),hepatocyte growth factor(HGF,10 ng/ml),epidermal growth factor(10 ng/m1)and 1×insulin-transferrin-Se(ITS)for two weeks,then in DMEM/F12 supplemented with 0.5 μmol/L dexamethasone,10 ng/ml HGF,1×ITS,10 ng/ml Oncostatin M for another two weeks.Morphological changes were observed under a microscope.The gene expression correlated with hepatocytes was detected by using RT-PCR.Immunofluorescence staining was used to identify the expression of specific protein related to hepatocytes(AFP,Albumin,CK-18).Ultrastructure was detected under an electron microscope.Results In the cultured MSCs from UCB,CD34/CD45/CD14,CD54,CD49f and HLA-DR were not detected,there was low expression of CD106 and strong expression of CD29,CD44 and CD13.The gene expression of AFP,albumin,CK-18 and TAT was discovered and three kinds of protein AFP,albumin and CK-18 were positively showed in cytoplasm after 4 weeks'induction.The hepatin granules and fatty drops in cytoplasm of cells induced for 4 weeks were found under an electron microscope.Conclusion The MSCs fromUCB can differentiate into hepatocyte-like ceils in the in vitro culture under some conditions.