Cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide(MTT)method.DNA fragmentation was visualizedby agarose gel electrophoresis.Phospho-p38 mitogen-activated protein kinase(MAPK)expression
查找更多 was detected by Western blotting.Results:Aspirin at lowconcentrations from 1×10~(-10)mol/L to 1×10~(-8)mol/L decreased the apoptosis andp38 MAPK pbosphorylation induced by H_2O_2 in BAEC,while high doses of aspi-rin(1×10~(-7)-1×10~(-4)mol/L)induced typical apoptotic changes in BAEC and stimu-lated the expression of phospho-p38 MAPK in a concentration-dependent manner.SB203580,a specific p38 MAPK inhibitor,blocked such effects.Conclusion:Aspirin exhibits a biphasic effect on the apoptosis in BAEC,reducing apoptosisat low concentration and inducing apoptosis at high concentration,p38 MAPKmay be an important signal molecule mediating the effects of aspirin.
Aim:To characterize the molecular mechanisms of nitrofen-induced pulmonaryhypoplasia.Methods:After administration of nitrofen to cultured type Ⅱ A549pneumocytes,cell proliferation and DNA 寻找更多 synthesis
were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetry,colony forma-tion assay,flow cytometry and[~3H]-thymidine incorporation assay.Apoptosiswas measured by terminal transferase-mediated dUTP nick-end-labeling,acridineorange-ethidium bromide staining and flow cytometry.Expression of proliferatingcell nuclear antigen (PCNA) and apoptosis-related genes was assayed byimmunofluorescence,RT-PCR and Western blot.Results:Nitrofen inhibited thecell proliferation of A549 cells in a dose-and time-dependent manner,accompa-nied by downregulation of PCNA.As a result,the DNA synthesis of nitrofen-treated A549 cells decreased,while cell cycle was arrested at G_0/G_1 phase.Moreover,nitrofen induced apoptosis of A549 cells,which
was not abolished by Z-Val-Ala-Asp(OCH_3)-fluoromethylketone.In addition,nitrofen decreased the expressionof Bcl-x_L,but not of Bcl-2,Bax,and Bak,resulting in a loss of mitochondrialmembrane 点击此处 potential and the nuclear translocation of apoptosis-inducing factor(AIF).Meanwhile,nitrofen strongly activated the p38 mitogen-activated proteinkinase (p38-MAPK).Pretreatment of cells with SB203580 (5 μmol/L) blockednitrofen-induced phosphorylation of p38-MAPK and abolished nitrofen-inducedAIF translocation and apoptosis in A549 cells.Conclusion:Nitrofen suppressesthe proliferation of cultured type Ⅱ pneumocytes accompanied by thedownregulation of PCNA,and induces mitochondria-mediated apoptosis involv-ing the activation of p38-MAPK.
AIM: To investigate whether heat shock pretreatment(HSP) improves mesenchymal stem cell(MSC) repair via autophagy following hepatic ischemia-reperfusion injury(HIRI).METHODS: Apoptosis of MSCs was induced by 250 m M hydrogen peroxide(H2O2) for 6 h. HSP was carried out using a 42 ℃ water bath for 1, 2 or 3 h.