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ObjectiveTo study the effect of hydrogen peroxide (H2O2) in inducing apoptosis of typeⅡalveolar epithelial cell (AECⅡ) after overexpression by adenoviral transfection of micro RNA-21-5p (miR-21-5p), and to explore the mechanism of its anti-apoptosis.Methods Subculture AECⅡ were randomly divided into four groups: normal control group (normal saline), H2O2 challenge group ( 0.5 mmol/L H2O2), miR-21-5p overexpression group (miR-21-5p adenovirus+ 0.5 mmol/L H2O2), miR-21-5p negative transfection group (adenovirus void+0.5 mmol/L H2O2). Transmission electron microscopy and flow cytometry were used to detect apoptotic morphology and early apoptotic rate. Real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of miR-21-5p in AECⅡ, and Western Blot was used to detect the protein expressions of Bcl-2, Bax, and caspase-3 at the highest transfection efficiency at different time points (6, 12, 24, 48 hours).Results ① AECⅡ identification: fluorescence microscopy showed the presence of characteristic structure of AECⅡ, i.e. microvilli and osmiophilic lamellar bodies.② Apoptotic morphology: transmission electron microscopy showed cytoplasmic retraction, chromatin condensation, margination, lack of cell surface microvilli, and emptying of osmiophilic lamellar bodies in AECⅡ.③ The expression of miR-21-5p in AECⅡ: the highest transfection efficiency was found at 48 hours. The expression of miR-21-5p in miR-21-5p overexpression group was significantly higher than that of the normal control group, H2O2 challenge group and miR-21-5p negative transfection group (A value: 1.54±0.02 vs. 1.02±0.02, 0.56±0.03, 0.58±0.02, allP< 0.05).④ The rate of early apoptosis: compared with normal control group, the early apoptotic rates in H2O2 challenge group, miR-21-5p negative transfection group and miR-21-5p overexpression group were gradually elevated with the prolongation of injury time. The early apoptotic rate in miR-21-5p overexpression group was significantly lower than that of the H2O2 challenge group and miR-21-5p negative transfection group at all time points except 6 hours [12 hours: (10.73±2.80)% vs. (16.26±0.59)%, (16.04±0.70)%; 24 hours:(16.00±3.44)% vs. (23.29±2.78)%, (23.58±2.31)%; 48 hours: (31.30±3.55)% vs. (50.53±2.17)%, (49.41±1.97)%, allP< 0.05]. There was no significant difference in early apoptotic rate between miR-21-5p negative transfection group and H2O2 challenge group at each time point.⑤ Protein expression: the expressions of Bax and caspase-3 in miR-21-5p overexpression group were significantly lower than those of the H2O2 challenge group and miR-21-5p negative transfection group [Bax (A value): 0.07±0.01 vs. 0.18±0.01, 0.13±0.01; caspase-3 (A value): 0.07±0.01 vs. 0.23±0.01, 0.12±0.01, allP< 0.05], and Bcl-2 protein expression was significantly higher than that of the H2O2 challenge group and miR-21-5p negative transfection group (A value: 0.26±0.01 vs. 0.06±0.01, 0.10±0.01, both P< 0.05).Conclusions① miR-21-5p has the function of anti-apoptosis of AECⅡ.② Adenoviral vector is a successful gene transfer vector when transfected with AECⅡ.③ The anti-apoptosis of AECⅡ by miR-21-5p may be associated with reduced Bax and caspase-3 protein levels and raised expression levels of Bcl-2 protein.
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Objective To explore the prognosis related genes of pancreatic ductal adenocarcinoma (PDAC)and investigate the molecular regulation mechanism.Methods Gene expression data of 102 PDAC patients with complete clinical survival data were selected from gene expression database of National Center for Biotechnology Information.The 106 transcription regulation gene collection was collected from Transfac database.The 715 microRNA (miRNA)target regulation gene collection was selected according to PicTar and TargetScanS method.Biological pathway data obtained from the Kyoto Encyclopedia of Genes and Genomes (KEGG).The known cancer genes were collected from the cancer gene census (CGC) database.Univariate Cox proportional hazards model was used to analyze the correlation between gene expression data and survival time,then obtained survival related candidate genes from the whole genome. Then the enriched genes were analyzed by hypergeometric distribution algorithm from three databases. Multiple correction testing was performed by BH-FDR method (FDR < 0.05 ).Kaplan-Meier was performed for survival curve analysis of PDAC.Results The results of data of 102 PDAC patients analyzed by univariate Cox proportional hazards model indicated that 273 genes were significantly related to the survival time of patients (P <0.000 1 ).After 273 survival genes were enrichment analyzed in 106 transcription factor regulation gene collection,12 survival genes enriched transcription factor target gene sets were found.After 273 survival genes were enrichment analyzed in 715 miRNA target regulation gene collection,11 survival genes enriched miRNAs target sets were discovered.After 273 survival genes were enrichment analyzed in pathway data of KEGG,15 survival genes enriched pathways were obtained. Period circadian clock 2 (PER2 )was regulated by CCAAT/enhancer binding protein (CEBPA)at transcription level and regulated by miRNA-32 after transcription.The prognosis of PDAC was affected by circadian rhythm pathway.The 102 patients with PDAC were ranked according to the expression of PER2 from high to low,the first 51 cases were included in PER2 higher expression group and the left were included in PER2 lower expression group.Kaplan-Meier survival analysis indicated that PER2 was significantly correlated with prognosis of PDAC (P <0.01 ).Conclusion CEBPA/miRNA-32/PER2 and its related circadian clock pathway may be the target pathway in interfering the development of PDAC,and is correlated with the prognosis of PDAC.
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Objective To study the molecular mechanism of injection with hepatocyte growth factor (HGF) at different doses on angiogenesis in myocardium of dogs with acute myocardial infarction (MI).Methods Sixteen 1.5-year-old male hybrid dogs,weighing 11-13 kg,were divided into 500 ?g HGF treatment group,1 000 ?g HGF treatment group,sham operation group,and no MI interference group,4 dogs in each group.Expressions of VEGF,HGF,CD31,and platelet factor Ⅷ in myocardium of dogs with MI were detected,the number of micro blood vessels was calculated,and correlation between angiogenesis and expression of HGF and VEGF was analyzed in 28 d after the model was established.Results HGF gene therapy could up-regulate the expression of CD31 and VEGF.The expression of CD31 and VEGF mRNA was 0.82 and 0.39 respectively in 1 000 ?g HGF group,and 0.47 and 0.21 respectively in 500 ?g HGF group.The expression of VEGF mRNA was 0.09 and no expression of CD31 mRNA was found in MI group.HGF could increase the angiogenesis in infracted myocardium.The microvascular density was 126.4?10.6,79.8?6.0,and 21.7?2.5/mm2,respectively,in 1 000 ?g HGF group,500 ?g HGF group,and MI group (P