ABSTRACT
Objective To investigate the effect of granulocyte colony-stimulating factor(G-CSF)and its effect on the cognation in the PDGF hAPPV717I transgenic mice of Alzheimer's disease model.Methods Totally 36 PDGF hAPPV717I transgenic mice were randomly divided into two groups:G-CSF group and control group.The G CSF group was subcutaneously injected with 50 μg · kg-1 · d-1 of G-CSF for 7 days.The control group was injected subcutaneously with an equal volume of PBS in parallel.The animals were tested in Morris water maze on the 7th,14th,and 28th days after the last day of the injection,and the escape latency was recorded.Once the test was completed,the peripheral blood was taken to evaluate the effect of G-CSF to induce hematopoietic stem cells (HSCs) via flow cytometry.Then the mice were killed,their brains were quickly removed and frozen on dry ice.With the immunohistochemical staining and double immunofluorescence staining,the neurogenesis could be observed in the model mice.Results We found that G-CSF significantly shortened the escape latencies in PDGF-hAPPV717I transgenic mice compared to controls on the 7th,14th,and 28th day after G-CSF treatment [7 d:(27.19±4.07) s and (46.07±7.21) s,P＜0.000; 14 d:(26.48±5.29) sand (42.99±11.70) s,P＜0.010; 28 d:(24.97±3.61) s and (45.54±9.55) s,P＜0.002)].At the same time,we found that the percentage of CD34+/CD45+ cells in the peripheral blood was 0.358±0.161,0.223±0.038,0.168±0.049 on the 7th,14th,and 28th day after G-CSF treatment,respectively.Compared with the control group (0.073±0.026,0.067±0.034,0.072± 0.037),the percentage of CD34′ /CD45+ cells in the peripheral blood were increased (P＜0.001).BrdU+ cells were found in dentate gyrus (DG) of hippocampus and the cortex of the G-CSF group,where the BrdU+ /Ncstin- and BrdU-/MAP-2+ cells were also detected positively.Conclusions Subcutaneous administration of G- CSF may improve the cognition in APP transgenic mouse model of AD.G-CSF may mediate the proliferation,differentiation of hcmatopoietic stem cells (HSCs).and may induce the neural stem cells into the brain.
ABSTRACT
Objective To explore the optimal condition of direct differentiation into dopaminergic neurons of embryonic stem cells in serum-free and feeder layer cell free medium. Methods We used the method of phase induction to culture embryonic stem cells. At first, embryonic stem cells were cultured in the serum-free medium with bFGF and LIF so as to realize the direct differentiation from embryonic stem cells to neural precursors. Differentiated cells were determined by nestin immunocytochemical staining. On this basis, we transferred embryonic stem cells to the B27 serum-free medium with IL-1 so as to realize the direct differentiation from neural precursors to dopaminergic neurons. Differentiated cells were determined by TH immunocytochemical staining. Results Approximately 85 percent of cell masses were nestin immuno-positive. The differentiation ratio of dopaminergic neurons was 13%, which increased significantly in comparison with natural differentiation ratio of dopaminergic neurons.Conclusion Without serum and feeder layer cell, we can induce embryonic stem cells to differentiate into dopaminergic neurons effectively by adding different growth factors at different phases, which makes the inductive processes more easily.
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Objective To explore the survival,migration and differentiation of embryonic stem cells after transplantation into striatum and provide advantageous data for feasibility and safety of therapeutic transplantation. Methods We transplanted embryonic stem cells(undifferentiated ESCs and ESCs that had already developed into the stage of neural progenitor cells respectively) into striatum of the rat.Then differentiated cells were determined by morphological observation,Nissl's staining,TH and BrdU immunocytochemistry. Results We found that after transplanted 4 weeks,partially differentiated ESCs could survive and migrate into the surrounding host tissue.Some of them differentiated into TH-positive cells which had Nissl's bodies in cytoplasm.Whereas undifferentiated ESCs couldn't differentiate into TH-positive cells effectively and have the tendency to form tumor.Conclusion When conducting transplantation experiments of ESCs,it's better for ESCs to be induced into the stage of neural progenitor cells first and then transplanted.;
ABSTRACT
Objective To explore the inductive effect of striatal tissue on mouse embryonic stem cells and further analyse the cell source and inductive pattern of this inductive effect. Methods We employed striatal extracts、conditioned medium of striatal astrocytes and conditioned medium of striatal neurons to induce embryonic stem cell to differentiate directly. The differentiated cells were evaluated by morphological observation and TH immunocytochemical staining method. We also performed a quantitative analysis of the results. Results Striatal extracts and conditioned medium of striatal astrocytes had obvious inductive effect on embryonic stem cell.Percentages of three groups were 15%,15.2% and 3% respectively. Conclusions The astrocytes in striatum might have an inductive effect on dopaminergic neuronal differentiation of embryonic stem cells.The determination of inductive factor will be our next research aim.;
ABSTRACT
Objective To carry out construction of chimeras from embryonic stem cells of outbred KM mice. Methods We isolated embryonic stem cells from inner cell mass of KM mice blastocysts. Then we transferred embryonic stem cells into blastocoele of C57BL/6J inbred mice by microinjection in order to construct chimeric mice. Results The cells isolated from inner cell mass have typical characteristics,i e positive alkaline phophatase staining,normal karyotype,forming embryoid body. Now,we have constructed one chimeric mice successfully. Conclusion Embryonic stem cells isolated from inner cell mass can be used for the chimeras production successfully,which forms the substantial base of transgenic animal model by the way of using embryonic stem cells.