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.
8.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.
9.Induction of umbilical cord blood-derived mesenchymal stem cells differentiating into pancreatic islet β-like cells in vitro
Zuohua CHI ; Yan LU ; Yuan ZHANG
Chinese Journal of Tissue Engineering Research 2010;14(49):9307-9310
BACKGROUND: At present,there are many reports regarding the differentiation of bone marrow-derived mesenchymal stem cells or pancreatic gland stem cells into pancreatic islet β-like cells.But little is about umbilical cord blood-derived mesenchymal stem cells(UCBMSCs)differentiation into pancreatic islet β-like cells in vitro.OBJECTIVE: To investigate whether UCBMSCs can differentiate into pancreatic islet β-like cells in vitro and the optimal inducing condition.METHODS: UCB samples were obtained sterilely from healthy parturients.Nucleated cells were isolated by sedimentation with hydroxyethyl starch and MSCs were obtained by adherent method.Then purified UCBMSCs were induced with epidermal growth factor,β-mercaptoethanol,high glucose,Activin A and hepatocyte growth factor(HGF).Following cell morphology observation,induced cells were identified by insulin immunofluorescence.In addition,insulin secretion and glucose-stimulated insulin release were examined by chemiluminescence immunoassay.RESULTS AND CONCLUSION: After induction,many cells exhibited a round appearance and produced islet-like cell clusters.Immunofluorescence assay showed insulin positive in the treated cells.In addition,chemiluminescence immunoassay demonstrated low expression of insulin and secretion of insulin upon glucose challenge.UCBMSCs can differentiate into pancreatic islet β-like cells in vitro.
10.Differentiation of human umbilical cord blood-mesenchymal stem cells into hepatocyte-like cells using in vitro combination of various growth differentiation factors
Zuohua CHI ; Yuan ZHANG ; Yan LU
Chinese Journal of Tissue Engineering Research 2009;13(49):9797-9800
BACKGROUND: Reproductive activity of hepatocytes is limited. There are numerous studies concerning stem cells differentiation into hepatocytes, including embryonic stem cells, bone marrow cells, pancreas stem cells, neural stem cells, various sources of mesenchymal stem cells.OBJECTIVE: To explore the possibility of induction of mesenchymal stem cells (MSCs) from umbilical cord blood (UCB) into hepatocyte-like cells in vitro culture.DESIGN, TIME AND SETTING: A cytological in vitro study was performed at the Institute of Hematology, Medical College of Jinan University from October 2005 to April 2006.MATERIALS: Fetus cord blood was obtained from spontaneous delivery and caesarean delivered healthy pregnant women at the Department of Obstetrics and Gynecology, First Affiliated Hospital of Jinan University. The parturients signed the informed consents.METHODS: UCB-MSCs were incubated in vitro, and digested in trypsin-EDTA. The third passage of cells at 5 × 10~4 cells/cm~2 wereinoculated. Original medium was removed 48 hours later. Cells were washed in phosphate-buffered saline. In the first phase, cells were incubated in F12 medium supplemented with dexamethasone, hepatocyte growth factor, epidermal growth factor and 1 ×its for 2 weeks. In the second phase, cells were incubated in F12 medium containing dexamethasone, hepatocyte growth factor,oncostatin M and 1 × ITS for two weeks.MAIN OUTCOME MEASURES: The following parameters were measured: expression of surface marker of UCB-MSCs using flow cytometry, expression of related gene and protein of hepatocytes following induction respectively using RT-PCR and immunofluorescence staining.RESULTS: No CD34/CD45/CD14 of hematopoietic markers were detected, either no the CD54, CD49f, HLA-DR were found. The low expression of CD106 and high expression of CD29, CD44, CD13 were found. The gene expression of a-fetoprotein, albumin,CK-18 and TAT were discovered, and three kind of protein a-fetoprotein, albumin, CK-18 were positively observed in cytoplasm after 4 weeks of induction using immunofluorescence staining.CONCLUSION: UCB-MSCs are able to differentiate into hepatocyte-like cells in vitro culture following combination with many growth differentiation factors, such as dexamethasone, hepatocyte growth factor, epidermal growth factor, tumorigenesis M and ITS.