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Objective The aim of current study is to determine the effect and mechanism of thymic stromal lymphopoietin on apoptosis of mouse nucleus pulposus cells by investigating the apoptotic activity and variation of intracellular phosphorylated protein kinase B (p-Akt),X-linkedinhibitor of apoptosis protein (XIAP),cysteinyl aspartate specific proteinase-3 (caspase-3),with the treatment of thymic stromal lymphopoietin.Methods Mouse lumbar nucleus pulposus cells were cultured and identified under a fluorescence microscope.Second or third passage cells maintained in monolayers were used for the following experiments.The groups were divided randomly into normal group,TNF-α treated group,TSLP treated group,TSLP+LY94002 treated group and TSLP+Embelin treated group.As a control,normal group was treated with PBS.TNF-α treated group was treated with 500 ng/ml TNF-αt as a positive control.TSLP treated group was treated with 10 ng/ml rhTSLP.TSLP+LY94002 treated group and TSLP+ Embelin treated group were treated with 10 ng/ml TSLP with the pretreatment of different pathway inhibitors for 30 ain in different corresponding experiments,for which 10 μ mol LY294002 or 50 LY294002 responding experimentsreatment of different pathway inhibitors formouse nucleus pulposus cells was detected by FACS.The expression levels of the intracellular p-Akt,XIAP,caspase-3 were investigated by Western blot analysis.Results As the culture cell type Ⅱ collagen staining was positive observed by fluorescence microscopy,we confirmed that the cuhured cells were nucleus pulposus cells.In comparison with negative control,the levels of p-Akt,XIAP in TSLP treated group were elevated (t=9.510,P=0.001;t=8.851,P=0.001).Thecaspase-3 activity were slightly enhanced and the rate of cells apoptosis was no significance.Compared with TSLP treated group,downregulated level of pAkt and XIAPand upregulatedcaspase-3 activity in TSLP+LY294002 treated group were observed (t=8.798,P=0.001;t=7.032,P=0.002;t=5.908,P=0.004).Upregulated caspase-3 activity were also observed in TSLP+ Embelin treated group (t=7.990,P=0.001).Furthermore,significant increased apoptotic cell rate was observed in TSLP+LY294002 or TSLP+Embelin treated groups (t=21.268,P=0.001;t=21.279,P=0.001).Conclusion TSLP may have a potential anti-apoptotic effect on mouse NP cells via upregulating XIAP in PI3K/Akt signaling pathway to restrain the activation of caspase-3.
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Objective To establish the MCF-7 cell models of Beclin 1 over-and low-expressions,and to detect the autophagic and apoptotic changes after 4 Gy irradiation,and to explore their molecular regulation mechanisms. Methods MCF-7,MCF-7 + 4Gy,MCF-7-Beclin 1 + 4Gy and MCF-7-Belcin 1 RNAi+ 4Gy groups were set up. Molecular biology method was used to construct Beclin 1 over-expression vector pcDNA3.1-Beclin 1,and to estabilish the Beclin 1 over- and low-expression cell models.After the cells were irradiated with 4 Gy, the autopahgic cell percentages were measured by fluorescence microscope with MDC staining, the apoptotic cell percentages were measured by FCM with AnnexinⅤ-FITC and PI staining,and the expressions of Beclin1,P53, Bcl-2 and Bax proteins were measured by Western blotting method.Results Compared with MCF-7 group,the autophagic and apoptotic cell percentages in MCF-7+4 Gy,MCF-7 Beclin 1 +4 Gy and MCF-7-Beclin 1 RNAi+4 Gy groups were significantly increased (P <0.05 or P <0.001 ),especially in MCF-7 Beclin 1+4 Gy group which was significantly higher than those in MCF-7 + 4 Gy (P < 0.05);while there was significant difference in the necrotic cell percentages between various groups. After 4 Gy irradiation, compared with MCF-7 group, the expression levels of Beclin 1,P53 and Bax proteins in MCF-7 + 4 Gy and MCF-7-Beclin 1 + 4 Gy groups were increased,but the expression levels of Bcl-2 protein were decreased,especially in MCF-7-Beclin 1 + 4 Gy group. Conclusion The MCF-7 cell models of Beclin 1 over-and low-expressions are successfully established,and ionizing radiation could induce the autophagy and apoptosis of MCF-7 cells,which is more obvious in Beclin 1 over-expression MCF-7 cells.Beclin 1 can activate P53,inhibit Bcl-2 and activate Bax,which forms the regulation of autophagy and apoptosis by P53 .
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Objective: To investigate the anti-tumor effects of tanshinone II A (TS II A) and its nanoparticles (TS-NP) against hepatoma in mice and possible mechanism. Methods: TS-NP was prepared by emulsion-solvent evaporation method. Hepatoma model was established in mice. The cell apoptotic index was tested by TUNEL staining, and expression of p33 mitogen activated protein kinase (p38 MAPK) and tumor growth factor β1 (TGFβ1) were detected by immunohistochemistry (SP method). Results: The weight of tumor in TS II A and TS-NP groups at different dosages was significantly lower than that in NS group (P < 0.01), and the survival time of mice in TS II A and TS-NP groups was significantly longer than that in NS group (P < 0.01). The apoptotic index of hepatoma cells in TS II A and TS-NP groups was increased compared with NS group (P < 0.01). The therapeutic outcome was more superior in TS-NP group than TS II A group at the same dosage. After treatment with TS II A and TS-NP, the expression of p38 MAPK was increased, but the expression of TGFβ1 was decreased (P < 0.01). The expression of p38 MAPK negatively correlated with TGFβ1 (r = -0.873, P < 0.001). Conclusion: TS II A and TS-NP could inhibit the growth of hepatoma and prolong the survival time of mice. The therapeutic outcome of TS-NP-treated group is better than that of TS II A-treated group at the same dosage. The anti-hepatoma mechanism may be associated with upregulation of the expression of p38 MAPK and downregulation of the expression of TGFβ1 which further inhibites cell proliferation and induces apoptosis.