Objective To establish the co-culture system of marrow stromal cells (MSCs)and A?1-40 injured PC12 in vitro and to evaluate the effect and mechanisms of the system inhibiting apoptosis of PC12 induced by A?1-40.Methods MSCs and PC12 were cultured in vitro and identified by CD44 immunofluorescent staining;PC12 were damaged by A?1-40,and transferred by transwell followed by the classification into 5 groups. PI and Annexin-V co-fluorescent staining was performed,then PC12 apoptosis were detected by flow cytometry and EM;Supernatant was analyzed by enzyme-linked immunoadsordent assay (ELISA) to detected TGF-?,NGF,BDNF,and bFGF. Results About 96% MSCs showed CD44 positive cells. Co-culture group had the lowest rate of PC12 apoptosis(46.17%?8.28%,F=61.637,P0.05). Conclusion The co-culture system of MSCs and A?1-40 injured PC12 in vitro could inhibit apoptosis of PC12 induced by A?1-40. Thus grafted MSCs have the possibility to inhibit neuronal apoptosis by A?in the diseased brain.

External use of either xanthotoxin or umbelliferone alone in normal rats showed that the chromosomes of the myelocyte were mutated at an aberrant rate of 2.0% and 0.2%, respectively (P

BACKGROUND: Drug treatment has unsatisfactory effect on Alzheimer disease, while many studies have indicated that the transplantation of bone marrow stromal cells (MSCs) is effective on Parkinson disease, cerebral ischemia, etc., but the mechanism is still unclear.OBJECTIVE: To imitate transplantation environment by co-culture of amyloid β1-40 (Aβ1-40) damaged PC12 cells and MSCs, observe the effect of bi-directional information feedback in the microenvironment on the transdifferentiation of MSCs to nerve cells, and observe its protective effect on the apoptosis of damaged PC12 cells.DESTGN: A comparative observation.SETTING: Department of Neurology, China Medical University.MATERIALS: SD rats of 2-3 weeks after birth either male or female were used. PC12 cell lines were purchased from the Institute of Cell Biology, Chinese Academy of Sciences; neuro-specific enolase (1:50, Boster, Wuhan);Methyl-thiazol-tetrazolium (MTT) 15 μL (terminal concentration of 0.5 g/L).METHODS: The experiment was carried out in the Experimental Center (provincial experimental animal center) of China Medical University from June to July in 2004. Bilateral femurs were aseptically removed from 1 SD rat, and MSCs were identified using CD44 antibody immunofiuorescently. PC12 was used to replace nerve cells. The PC12 cells were stimulated by Aβ1-40 then transferred by Transwell. There were 5 groups: Group A: normally cultured PC12 co-cultured with MSCs; Group B: Aβ1-40 stimulated PC12 co-cultured with MSCs; Group C: normal PC12 supernatant+MSCs; Group D: damaged PC12 supernatant+MSCs; Group E: MSCs cultured with common medium 1640.MAIN OUTCOME MEASURES:Routine immunohistochemical staining was performed. NSE positive cells were observed under inverted fluorescence microscope, 10 visual fields (200×) were randomly selected to count the positive cells. MTT metabolic rate was used to detect the proliferation of MSCs in each group. The differences of measurement data were compared using the one-way analysis of variance.fluorescent and bright fields, NSE positive cells appeared as red fluorescence, MSCs were bipolar, multipolar and cone shapes, and appeared as neuron-like forms with dendrite-like structure, and there were extensive connections among some neuron-like cells. The NSE positive rates was obviously higher in group B than groups A, C, D and E (P ＜ 0.01 ).in groups A, C, D and E (F=9.713, P＜ 0.01).

BACKGROUND: The primary pathophysiology of Alzheimer disease (AD) is linked to β-amyloid (Aβ)protein. Neural progenitor cells (NPCs), which have the ability of multipotency, self-renewal and repair,have been detected in the central nerve system (CNS) of adult rat recently. But effective function of these neural progenitor cells are not seen in the AD brain ,which mechanism is unclear.It is unclear if Aβ1-40protein is compromised by the signal pathway of c-Jun N-termial kinase associated with the neurotoxicity to the progenitor cells on the cortex of embryonic rats.OBJECTIVE: To investigate the mechanism of c-Jun N-terminal kinase signal transduction pathway of Aβ1-40 protein, which has neuronal toxicity to progenitor cells(CPC)on the cortex of embryonic rats . To detect the neuroprotective effects of c-Jun N-termial kinase inhibitor (SP600125) against Aβ1-40-induced neuronal toxicity to the cortical progenitor cells on the cortex of embryonic rats.DESIGN: A randomized and controlled trial with cells as objects.SETTING: Department of Neurology, First Hospital Affiliated to China Medical UniversityMATERIALS: This experiment was carried out at the Central Laboratory,China Medical University from May to October 2005. Embryos at age of 14 days from Wistar rats were used in this experiment.METHODS: Cortical progenitor cells harvested from Wistar embryonic rats were cultured in vitro, passaged and identified. Embryonic rat cortical progenitor cells of rats with good growth state were randomly divided into 4groups:Aβ1-40 group (10 nmol/L Aβ1-40 in each well);SP600125+Aβ1-40group (10 μmol/L SP600125 for 30 minutes and then with 10 nmol/L Aβ1-40 in each well); SP600125 group ( 10 μmol/L SP600125 in each well); Normal saline group (same volume of normal saline). The incubated durations were 0,2 hours, 4 hours, 6 hours, 12 hours, 24 hours respectively,8 wells for each time point. The cell survival rate was measured by MTF assay (The concentration of cortical progenitor cells on the cortex was 1×10s L-1 in each group), the apoptosis rate was detected by flow cytometer (The concentration of cortical progenitor cells on the cortex was 1 ×1010 L-1in each group) and the expression of c-Jun N-termial kinase and p-c-Jun N-termial kinase, c-Jun,p-c-Jun were measured by Western Blot(The concentration of cortical progenitor cells on the cortex was 1×1013 L-1 in each group). t test was adopted for the comparison of difference in measurement data.sion of c-Jun N-terminal kinase, p-c-Jun N-termial kinase ,c-Jun and p-c-Jun of embryonic rat CPC .ture time in Aβ group and SP600125 +Aβ group, decreased obviously at 4hours; cellular survival rate in Aβ1-40 group was lower obviously than that in the other 3 groups at 0,2,4,6,12,24 hours (P ＜ 0.01); Cellular survival rate in SP60025 +Aβ1-40 group was lower obviously than that in SP600125 group and normal saline group at 2,4,6,12,24 hours (P ＜ 0.01);Compared with normal saline group, the difference of cell survival rate was not significant without time-dependent manner in SP600125 group (P＞ 0.05).amyloid protein group and SP600125 +Aβ group, increased obviously at 4hours; cell apoptosis rate in Aβ1-40 group was higher obviously than that of the other 3 groups at 0,2,4,6,12,24 hours(P ＜ 0.01); Cellular apoptosis rate in SP60025+Aβ1-40 group was higher obviously than that in the SP600125 group and normal saline group at 2,4,6,12,24 hours (P ＜ 0.01);Compared with normal saline group, the difference of cellular apoptosis rate was not significant without time-dependent manner in SP600125 group 12,24 hours without changes in Aβ1-40 group; the expression of p-c-Jun N-terminal kinase and p-c-Jun in Aβ1-40 group were seen at 0hour ,increased gradually, reached to the peak at hour 4 and decreased gradually.CONCLUSION: Aβ1-40 could inhibit the cell activity of CPC , reduce cellular survival rate and induce cellular apoptosis. c-Jun N-terminal kinase signal transduction pathway may mediate the Aβ1-40 inducd neurnal apoptosis in AD which may be one reason for unseen rescue mechanism in AD. SP600125 (c-Jun N-terminal kinase inhibitor) could inhibit the activation of c-Jun N-terminal kinase and c-Jun and protect the embryonic rats CPC from the Aβ1-40-induced neurotoxicity.

Objective: Our purpose was to study the relationship between the Fas antigen expression and neuron apoptosis after cerebral ischemia. Methods: We detected the Fas antigen expression and neuron apoptosis dynamically in the animal models with cerebral ischemia by immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) method. Results: Fas antigen was positive after 30 minutes of ischemia and reached peak at 60 minutes. At the 24th hour, it began to decrease, and negative on the 3th day. While the positive cell for TUNEL method appeared after 60 minutes of ischemia, reached peak on 3 day, and decreased on 7 day. Conclusion: Neuron apoptosis after cerebral ischemia is closely related to the over-expression of Fas antigen.