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Objective To observe the correlation between the changes of neural cell apoptosis arid caspase-3 gene expression in brain tissues following acute severe traumatic injury to brain(TIB).Method A total of 120 adult Spraque-Dawley rats were divided into a control group(n=8)，TIB group(n=56)and TIB with administration of caspase-3 inhibitor group(n=56).TIB models of rats were made with Feeney's method.The z-DEVDfmk(5 μg)，caspase-3 inhibitor，was administered by intracerebral infusion，and the rats were sacrificed 1，6，24，48 hours and 3，7，14 days postinjury(n=8 for each interval).The specimens of the injured cerebral cortex，suhcerticai white matter，hippocampus，dentate gyrus and contrahteral corresponding brain tissues were taken for detecting apoptesis of neural cells by the terminal deoxynucleotidyl transferase mediated DUTP nick end labeling (TUNEL)methods and flow cytomeay.Caspase-3 mRNA and protein expression were detected by using RT-PCR，immunohistochemistry and western blot analysis.The caspase-3 activity was detected by using caspase-3 fluorescent assay kit.Student t-test and Spearman correlation analysis were used to analyze the data with SPSS version 10.1 software package.Results Apoptesis indexes(AI)and the apoptesis percentage(AP)of neural cells in the injured brain regions increased quickly after injury，and reached its peak 24 to 48 hours later，then decreased slowly,but it remained at higher level above that of normal till 14 days later(P＜0.01).The levels of caspase-3 mRNA,eastme-3 protein and caspase-3 activity were increased significantly post injury，and reached its peak at 24 to 48 hours，then it gradually decreased.Compared with control group，the levels ofoptical density of caspase-3 proteins in the injured hippocampus and subcortical white matter at 24 and 48 hours post injury increased 1484% and 1690%，caspase-3 mRNA expressiom increased 1043%and 1180%，and the degreas of caspase-3 activity increased 148% and 183%，respectively.The expression of caspase-3 proenzyme and its P17 subarrit increased.After trealment with caspase-3 inhibitor z-DEVD-fmk，the levels of caspase-3 mRNA，protein expression and caspase-3 activity were significantly decreased.and AI and AP were significantly decreased as well.The correlation between caspase-3 mRNA and level of neural apoptesis was positive(r=0.821，P＜0.01)，and it was likewise between caspase-3 protein and level of neural apoptosis(r=0.638.P＜0.01).Interestingly enough，a positive correlation was found between caspase-3 mRNA and easpase-3 proteins(r=0.945，P＜0.01).Conclusions The activation of caspase-3 leads to apoptosis of neural cells after acute TIB.The expression of caspase-3 are consistent with apoptosis of neural cells following TIB.The regulation of caspase-3 induced by TIB occurs at a ceriain critical link before transduction.Caspase-3 inhibitor can efficiently inhibit apoptosis of neural cells following TIB.
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Objective To observe the effect of DNA methyltransferase 1 (DNMT1 ) gene silencing by RNA interfering technology on the proliferation and apoptosis of HeLa cells. Methods Recombinant plasmid pshRNA-DNMT1-A, B and C were respectively transfected into HeLa cells by lipofectamine 2000, while cells transfected plasmid vector pSilencer3.1-HI and cells untreated as control groups. RT-PCR was adopted to select the recombinant plasmid which showed the most optimal inhibition effect. RT-PCR and western blotting was used to detected the mRNA and protein expression of DNMT1 in HeLa cells transfected for 24, 48 and 72 hours. Cell counting kit-8 (CCK-8 ) assay was used to investigate the proliferation of the HeLa cells after transfection, while apoptosis was detected by flowcytometry(FCM ) method. Results Three DNMT1-targeted short hairpin RNA (shRNA) A,B and C were successfully inserted into the plasmid vector PShRNA, and the coding sequences of the obtained shRNA were consistent with the designed fragments. The results indicated that both recombinant plasmid pshRNA-DNMT1-A and B could effectively knock down the expression of DNMT1 gene in human cervical cancer cells, of which pshRNA-DNMTI-B was the better choice. While no effect of pshRNA-DNMTI-C was seen. BT-PCR results showed that the relative mRNA expression of DNMT1 gene in Helm cells transfected with pshRNA-DNMT1 for 24, 48 and 72 hours were 0.406±0.057,0.191±0.036 and 0.104±0.015, which were significantly lower than that in Helm cells transfected by empty vector and non-transfected cells (0.520±0.020, 0.537±0.041, respectively, P ＜ 0.05 ). The western blotting analysis manifested that the relative expression of DNMT1 protein of Helm cells transfected by pshRNA-DNMT1 for 24, 48 and 72 hours were 0.197±0.024, 0.075±0.015, 0.040± 0.013, which were significantly lower than that in transfected cells by empty vector and non-transfected cells (0.273±0.010, 0.283±0.016, respectively, P ＜0.05). The CCK-8 results showed that the cell survival rates of HeLa cells transfected by pshRNA-DNMT1 for 24, 48, 72, 96 and 120 hours were 70.8%, 64.8%, 51.6%, 45.3% and 38.0%, there were statistically different compared with cells transfected by empty vector and non-transfected cells at different time-points (P ＜ 0.01 ). The results of FCM indicated that the apoptesis rate of HeLa cells trandected with pshRNA-DNMTI for 24, 48 and 72 hours were (17.7± 1.3 ) %, (35.3±1.3 ) %, (47.6±1.6 ) %, which were significantly higher than empty vector transfected cells and non-transfected cells [(4.9±0.5 ) %, (5.1±0.7 ) %, respectively, P ＜ 0.05]. Conclusions DNMT1 can be successfully silenced by RNA interfering in cervical Helm cells. Downregulation of DNMT1 can inhibit cervical cancer cells proliferation and induce cell apoptosis.
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Objective To investigate the dynamic changes of transcription profiles of mouse thymus gene expression in different times after 6 Gy γ-irradiation.Methods High-flux cDNA microarray technique was used irradiation,the numbers and types of differentially expressed genes were gradually decreased,for instance,the induced differential expression genes were involved in cell cycle,immunity and stress,apeptosis,signal transduction,transcription regulation,DNA synthesis and recombination,cystoskeleton,ion channel and transportation,metabolism,protein translation and synthesis,development and cell differentiation,etc.correlated cell cycle(3 up-regulating:Cyclin G,Anxal,Fgf1 and 2 down-regulating:Cdc2a,Cdc25b),5 genes correlated immune stress(4 up-regulating:IL-18,Casp1,IL-15,IL-7 and 1 down-regulating:Cd28),7 genes correlated apoptosis(4 up-regulating:Caspl,Anxal,Perp,IL-7 and 3 down-regulating:Pten,Api5 and Fas).Conclusions After 6 Gy irradiation,differentially expressed genes in mouse thymus is not only involved in many targets,levels and pathways,but also displayed an obvious difference in times.This reveals the regular pattern of differential expression genes in the process of injury and reconstitution in moderate dose irradiated mouse thymus.
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Objective To investigate apoptosis of polymorphonuclear neutrophil and activity of caspase-3 in the peripheral blood and discuss their correlation with development of multiple organ dysfunc- tion syndrome (MODS) after multiple injury. Methods A total of 55 patients with multiple injury were included in the prospective study, and divided into two groups, ie, MODS group (multiple injury patients who developed MODS,) and non-MODS group (multiple injury patients who were free from MODS). The activity of caspase-3 was detected by flow cytometry and the serum levels of IL-6 and IL-10 were detected by ELISA. Then, we evaluated whether the neutrophil apoptesis was correlated with the ser- um levels of IL-6 and IL-10 in patients with MODS. Results Compared with non-MODS group, neu- trophil apoptesis was significantly reduced and activated caspase-3 decreased significantly in MODS group (P <0.05). In MODS group, serum IL-6 was increased significantly while serum IL-10 was decreased significantly compared with non-MODS group. The apoptosis of neutrophil in multiple injury patients with MODS had a negative correlation with IL-6 levels but a positive correlation with IL-10 levels. Conclu- sions The delayed apoptosis of neutrophil due to decreased activated caspase-3 may play partial roles in the development of MODS after multiple injury. IL-6 and IL-10 may contribute to the apoptotic changes.