【 Abstract 】 Objective To probe into the role of inositol 1, 4, 5-trisphosphate (IP3) and bax gene expression in apoptosis of HepG2 cells induced by genistein (Gen). Methods HepG2 cells were treated with different concentrations including 20, 40, 60 and 80 μ mol/L Gen as HepG2 cells cultured with 0 μmol/L Gen for 72 h was control; HepG2 cells were treated with 60 μmol/L Gen for 6, 12, 24, 48 and 72 h as HepG2 cells treated with 60 μmol/L Gen for 0 h was control. IP3 content, bax mRNA expression and apoptosis rate were assayed by IP3- ［ 3H ］ Birtrak assay, RT-PCR and flow cytometry, respectively. ResultsHepG2 cells incubated with each concentration of Gen for 72 h ， IP3 content was lower than that of control 〔 (17.7 ± 1.3), (11.2 ± 0.9), (4.9 ± 0.5), (4.8 ± 0.3) pmol/106 cells vs (29.4 ± 0.5) pmol/106 cells 〕 , P ＜ 0.01 ； bax mRNA expression (RI which was the gray degree multiply area of bax/the gray degree multiply area of β -actin) was higher than that of control (0.26 ± 0.02, 0.33 ± 0.05, 0.35 ± 0.06, 0.38 ± 0.05 vs 0.09 ± 0.01), P ＜ 0.01 ； The apoptosis rate was higher than that of control 〔 (10.1 ± 0.9)%, (18.7 ± 1.6)%, (28.7 ± 2.5)%, (27.9 ± 2.0)% vs (2.6 ± 0.1)% 〕 , P ＜ 0.01. HepG2 cells were incubated with 60 μ mol/L Gen for 6, 12, 24, 48 and 72 h ， IP3 content was lower than that of control 〔 (22.6 ± 0.9), (12.0 ± 1.4), (7.5 ± 0.8), (5.6 ± 0.5), (4.3 ± 0.6) pmol/106 cells vs (29.2 ± 0.6) pmol/106 cells 〕 , P ＜ 0.01 ； bax mRNA expression was higher than that of control incubated with 60 μ mol/L Gen for above 12 h (0.25 ± 0.06, 0.29 ± 0.02, 0.30 ± 0.02, 0.35 ± 0.04 vs 0.09 ± 0.01), P ＜ 0.01 ； The apoptosis rate in groups incubated with 60 μ mol/L Gen for 24, 48 and 72 h was significantly higher than that in control 〔 (7.4 ± 0.5)%, (20.5 ± 2.0)%, (30.7 ± 1.6)% vs (2.6 ± 0.1)% 〕 , P ＜ 0.01. ConclusionGen induces apoptosis of HepG2 cells by reducing IP3 production and increasing bax gene expression.
Objective To observe the outcomes of using different concentrations of arsenic trioxide at varying phases on the breast cancer cell line MCF-7 and to study the mechanism of this effect. Methods The effect of arsenic trioxide on the growth of breast cancer cell line MCF-7 was observed after applying arsenic trioxide of different concentrations （0.5-16 μmol/Ｌ）. The inhibitory effect of arsenic trioxide on the cell proliferation was investigated with 3-(4，5-dimethyl-thizazol-2-yl)-2， 5-diphenyl tetrazolium bromide (MTT) and the induction of arsenic trioxide on cell apoptosis was detected by DNA ladder and terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL). Results The effect of arsenic trioxide on breast cancer cell line MCF-7 depended on the phase and the dose. The number of cell decreased significantly and there were conspicuously typical morphological changes of apoptosis after the use of arsenic trioxide， including membrane blebbing， chromatin pyknosis, nuclear fragmentation and the formation of apoptotic body. The typical DNA ladders were observed in the MCF-7 cells after 48 h administration of arsenic trioxide at concentrations 1-8 μmol/Ｌ. Significant elevations of apoptosis index at 24 h, 48 h and 72 h were all detected by TUNEL after incubating with 4 μmol/L arsenic trioxide. Conclusion Arsenic trioxide may inhibit the growth of breast cancer cell line MCF-7 significantly by inducing the apoptosis of breast cancer cell.
Objective
To construct human secreted apoptosis-related protein 1 (SARP1) gene yeast two-hybrid bait vector so as to study the biological functions of the SARP1 gene in the scar tissue.
Methods
The target gene from SARP1 gene full-length DNA segment was amplified by PCR, the upstream and downstream primers of the SARP1 gene with restriction enzymes Nde I and Sal I were designed. pGBKT7-SARP1 recombination plasmid was constructed by ligating the vector and the PCR production and identified by PCR and sequencing. Further more, pGBKT7-SARP1 was transformed into competent AH109 which contained kanamycin for selecting positive clones and screened the positive clony on the plate of SD/-Trp. The toxicity and transcriptional activation were tested by the phenotype assay.
Results
SARP1 was amplified and cloned into pGBKT7 successfully, SARP1 gene sequence in recombinant plasmid pGBKT7-SARP1 was verified by gel electrophoresis and DNA sequencing analysis. The sequence of inserted SARP1 gene was the same as the corresponding sequence found in GenBank database. The recombinant pGBKT7-SARP1 plasmids and empty pGBKT7 vector could form white colonies on SD/-Trp plates and none could survive on SD/-Leu plates.
Conclusion
The recombinant pGBKT7-SARP1 gene yeast two-hybrid bait vector is successfully constructed.
Objective To investigate the pathogenesis of acute lung injury in rats induced by intra-peritoneally injection of perforative peritonitis ascitic fluids（PPAF） and the role of L-arginine （L-Arg） in acute lung injury in this model. Methods Perforative peritonitis （PP） models were established in 60 rats and PPAF were collected. Forty-eight rats were randomly divided equally into NS group，PPAF group, and L-Arg group. Rats were randomly subjected to death at 7 h and 12 h. Peripheral blood WBC were counted，levels of NO and malondialdehyde （MDA） in serum were examined. Lung injury score and wet/dry ratio were evaluated， and level of myeloperoxidase （MPO） in lung tissues and lung cell apoptosis were tested. Results WBC count of peripheral blood, levels of NO and MDA in serum， level of MPO in lung tissue, lung injury score， wet/dry ratio， and lung cell apoptosis rate in PPAF group were significantly higher than that in NS group at each time point（P＜0.01）. Level of NO in serum in L-Arg group was higher than that in PPAF group （P＜0.01）， but lower level of MDA in serum， lower level of MPO in lung tissue and lung injury score，lower wet/dry ratio， and lung cell apoptosis rate were observed in L-Arg group（P＜0.05）. In PPAF group and L-Arg group， level of NO in serum， wet/dry ratio, and lung cell apoptosis rate were higher at 12 h than that at 7 h（P=0.000）. Serum NO level was in negative correlation with serum MDA level （r=-0.257，P=0.021）， MPO level in lung tissue（r=-0.444， P=0.011），and lung cell apoptosis（r=-0.351， P =0.010） in PPAF group and L-Arg group， but serum MDA level was in positive correlation with cell apoptosis（r=0.969， P＜0.001） in each group. Conclusions Acute lung injury rats model can be established by intra-peritoneally injection of PPAF. Enhanced oxidizing reaction and cell apoptosis take part in the occurrence of acute lung injury. L-Arg plays a protective role in acute lung injury.
【Abstract】 Objective To investigate the expression and significance of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors in pancreatic cancer. Methods Thirty-two samples of pancreatic cancer tissue were collected from year 2002 to 2004. All of them were verified by histopathology and there were 9 cases of well-differentiated, 12 of moderately differentiated, and 11 of poorly differentiated, in which 12 cases were in the stage of Ⅰor Ⅱand 20 in the stage of Ⅲ or Ⅳ according to the TNM staging method. Eighteen normal pancreatic tissues were used as control group. The expressions of TRAIL receptors (death receptor 4, death receptor 5, decoy receptor 4 and decoy receptor 5) mRNA were assayed by semi-quantitive reverse transcription polymerase chain reaction (RT-PCR) in the pancreatic cancer tissues and the normal pancreatic tissues. Results The expressions of death receptor 4 (DR4) and death receptor 5 (DR5) were detected in all the pancreatic cancer tissues and the normal pancreatic tissues and the levels of DR4 and DR5 were significantly higher than those of the normal pancreatic tissues (P＜0.01). Decoy receptor 1 (DcR1) and decoy receptor 2 (DcR2) were also expressed in normal pancreatic tissues, whereas DcR1 and DcR2 were only expressed in 18 and 20 pancreatic cancer tissues, respectively. However, there were no significant difference of the expression of DcR1 and DcR2 between the pancreatic cancer tissues and the normal pancreatic tissues （Pgt;0.05）. The expression level of DR5 in pancreatic cancer tissue was correlated with tumor differentiation and clinical stage, and the levels in stage Ⅲ and stage Ⅳwere significantly lower than those of stageⅠand stageⅡ(P＜0.05). The expressions of DR4, DcR1 and DcR2 were not correlated with tumor differentiation and clinical stage (Pgt;0.05). Conclusion ①The expression of TRAIL receptors in pancreatic cancer tissues is prevalent, but the types of receptors expressed in different tissues were also different. High expression of death receptors may play an important role in TRAIL recptors regulated pancreatic cancer apoptosis. ②The expression of DR5 is correlated with the differentiation degree of pancreatic cancer cell and clinical stage of tumor. The expressions of DR4, DcR1 and DcR2 should not be considered as related indexes of differentiation degree or clinical stage of pancreatic cancer.
ObjectiveAfter establishing the rabbit brain death model, TUNEL, western blotting, and immuno-histochemical methods were used to detect hepatocyte apoptosis to study hepatocyte apoptosis level from rabbit donors after brain death.
MethodsSixty healthy male New Zealand rabbits were divided into brain death group (n=30) and sham group (n=30). The rabbits of brain death group were established by increasing intracranial pressure in a modified, slow, and intermittent way, collecting liver tissues after corresponding treatment respectively, using TUNEL to detect apoptosis rate, western blotting and immunohistochemical methods to detect the expression of Cleaved-caspase 3.
ResultsThe hepatocyte apoptosis rate at each time point of brain death group were higher than those of the corresponding time point of sham group (P<0.05), and the rate of hepatocyte apoptosis increased gradually with the extension of brain death time (P<0.05). The results of Western blot assay and immunohistochemistry assay showed that the relative expression amount of Cleaved-caspase 3 protein increased gradually with the extension of brain death time (P<0.05), and relative expression amount of Cleaved-caspase 3 protein at each time point of brain death group were higher than those of the corresponding time point of sham group (P<0.05).
ConclusionsThe relationship between brain death donor liver and cell apoptosis is closely related. Along with the extension of the brain death time in rabbits, the level of apoptosis of liver cells gradually increased, which affects the quality of liver donors after brain death.
【Abstract】ObjectiveTo construct the eukaryotic expressing plasmid of tumor necrosis factor-related apoptosisinducing ligand（TRAIL），and study its inhibitory effect on hepatic tumor which implanted subcutaneously in nude BALB/c mice.MethodsTotal RNA of U937 cell was extracted, and its extracellular domain (114-281aa) was amplified by RTPCR, then signal peptide was ligated. The recombinant secreting plasmid for TRAIL was constructed successfully which was confirmed by enzyme cleavage identification and sequencing identification. Liver cancer cell (strain No.7402) was implanted subcutaneously in 32 nude BALB/c mice. These mice were randomly divided into two groups: study group and control group. The mice in study group received muscular injection of plasmids for transfection, and the mice in control group received the injection of normal saline at the same time. The size of implanted tumors were measured continuously till the day of sacrificing, tumor cell apoptosis effect was examined by TUNEL method. ResultsIn study group，tumor volume was smaller than that in control group and the bluepurple apoptosis cells were observed under microscope. ConclusionTRAIL plasmid can induce apoptosis of liver cancer cell and can inhibit the growth of liver tumor.
ObjectiveTo evaluate the expression of miR-338-5p in colorectal cancer tissues and study its role in colon cancer cell proliferation, apoptosis, and cell cycle.
MethodsThe expression of miR-338-5p was detected by real-time PCR in the colorectal cancer tissues and corresponding adjacent to cancer tissue samples. The miR-338-5p-mimics was transfected into the colon cancer cell lines HCT116 and SW620 to investigate its role in cell proliferation, apoptosis, and cell cycle. The cell proliferation and apoptosis were measured by CCK-8 and flow cytometry, respectively. The cell cycle was also analyzed by flow cytometry.
Results①miR-338-5p expression was significantly downregulated in the colorectal cancer tissues as compared with corresponding adjacent to cancer tissue samples(P < 0.01). 2 Compared with the transfected negative control cells, the proliferation ability of colon cancer cell HCT116 or SW620 was significantly decreased(P < 0.01), cell apoptosis was significantly increased[HCT116 cell:(11.43±0.67)% versus(7.98±0.36)%, P < 0.01;SW620 cell:(10.5±0.2)% versus(7.93±0.5)%, P < 0.01), and cell G1 was arrested[HCT116 cell:(80.41±1.34)% versus (64.87±1.83)%, P < 0.01;SW620 cell:(68.76±0.41)% versus(54.89±0.78)%, P < 0.01) after transfecting miR-338-5p-mimics cells.
ConclusionmiR-338-5p may act as an anti-oncogene in colorectal cancer through regulation of cell proliferation, apoptosis, and cell cycle.
Objective To explore the molecular mechanism of miR-515-5p in inhibiting chondrocyte apoptosis and alleviating inflammatory response in osteoarthritis (OA). Methods Human cartilage cell line C28/I2 was cultured in vitro and treated with 10 ng/mL interleukin 1β (IL-1β) for 24 hours to construct an in vitro OA model. C28/I2 cells were transfected with miR mimics, mimics negative control (NC), over expression (oe)-NC, and oe-Toll-like receptor 4 (TLR4), respectively, and then treated with 10 ng/mL IL-1β for 24 hours to establish OA model. Cell proliferation capacity was detected by cell counting kit 8 and 5-Ethynyl-2’-deoxyuridine, cell apoptosis and cell cycle were detected by flow cytometry, and B-cell lymphoma 2 protion (Bcl-2), Bcl-2-associated X protein (Bax), cleaved-Caspase-3, TLR4, myeloid differentiation primary response gene 88 (MyD88), p65 and phosphorylated p65 (p-p65) protein expression levels were detected by Western blot. Real-time fluorescence quantitative PCR was used to detect mRNA expression levels of miR-515-5p and TLR4, and ELISA was used to detect pro-inflammatory factor prostaglandin E2 (PGE2), tumor necrosis factor α (TNF -α), and IL-6 levels in cell supernatant. The potential binding sites between miR-515-5p and TLR4 were predicted by BiBiServ2 database, and the targeting relationship between miR-515-5p and TLR4 was verified by dual luciferase reporting assay. Results After the treatment of C28/I2 cells with IL-1β, the expressions of miR-515-5p and Bcl-2 protein and the proliferation ability of C28/I2 cells significantly reduced. The expression levels of Bax and cleaved-Caspase-3 protein, the levels of pro-inflammatory factors (PGE2, TNF-α, IL-6) in the supernatant of C28/I2 cells, and the apoptosis of C28/I2 cells significantly increased. In addition, the proportion of the cells at S phase and G2 phase decreased significantly, and the proportion of cells at G1 phase increased significantly, suggesting that the cell cycle was blocked after IL-1β treatment. After transfection with miR mimics, the expression level of miR-515-5p in the cells significantly up-regulated, partially reversing the apoptosis of OA chondrocytes induced by IL-1β, and alleviating the cycle arrest and inflammatory response of OA chondrocytes. After treating C28/I2 cells with IL-1β, the mRNA and protein levels of TLR4 significantly increased. Overexpression of miR-515-5p targeted inhibition of TLR4 expression and blocked activation of MyD88/nuclear factor κB (NF-κB) pathway. Overexpression of TLR4 could partially reverse the effect of miR mimics on IL-1β-induced apoptosis and inflammation of OA chondrocytes. ConclusionmiR-515-5p negatively regulates the expression of TLR4, inhibits the activation of MyD88/NF-κB pathway and apoptosis of OA chondrocytes, and effectively alleviates the inflammatory response of the cells.
ObjectiveUnder hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.MethodsThe hAMSCs were isolated and cultured from amniotic membrane tissue from voluntary donors who were treated with cesarean section. And the morphological observation by inverted phase contrast microscope and immunofluorescence detection of the expressions of stem cell markers OCT-4 and NANOG were performed to identify the cultured cells. The third generation hAMSCs were treated with 200 μmol/L CoCl2, and transient transfection of plasmids were added according to the following grouping: group A was hAMSCs blank group; group B was pcDNA3.1 negative control group; group C was short hairpin RNA (shRNA) negative control group; group D was shRNA-HIF-1α interference group; group E was pcDNA3.1-HIF-1α over expression group. Cell survival rate of each group was measured by cell counting kit 8 (CCK-8) at 12, 24, 48 hours after hypoxia treatment. Flow cytometry was used to detect apoptosis rate of each group at 24 hours after hypoxia treatment. The expression levels of HIF-1α, vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), Bax, and cleaved Caspase-3 (C-Caspase-3) proteins were detected by Western blot at 24 hours after hypoxia treatment.ResultsCCK-8 assay showed that the cell survival rate of group D was significantly lower than those of groups A and C at all time points after hypoxia treatment; while the cell survival rate in group E was significantly increased than those in groups A and B, and the diffrences at 24 hours were significant (P<0.05). In group E, the cell survival rate at 24 hours was significantly higher than those at 12 and 48 hours (P<0.05). The results of flow cytometry showed that the apoptosis rate in group D was significantly higher than those in groups A and C (P<0.05), and the apoptosis rate in group E was significantly lower than those in groups A and B (P<0.05). Western blot showed that the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group D were significantly decreased when compared with those in groups A and C, and the expressions of Bax and C-Caspase-3 proteins were significantly increased (P<0.05). On the contrary, the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group E were significantly higher than those in groups A and B, and the expressions of Bax and C-Caspase-3 proteins were significantly decreased (P<0.05).ConclusionOverexpression of HIF-1α gene can significantly improve hAMSCs tolerance to hypoxia, the mechanism may be related to up-regulation of VEGF and Bcl-2 expressions, and down-regulation of Bax and C-Caspase-3 expressions.
