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Aim To investigate the effect of sevoflurane preconditioning on spinal cord ischemia-reperfusion in-jury ( SCIRI ) of miR-199a-5p in rats. Methods Twenty-four SD rats were randomly divided into: group of sham ( Sham group) , group of ischemia-reperfusion ( I/R group ) , and group of sevoflurane and control ( SEVO+I/R group) . Sham group received the same operation, but did not inhale sevoflurane or close the aortic arch; SCIRI model was established after 14 min of the aortic arch of the non-invasive arterial clip in I/R group. SEVO+I/R group, before the establishment of SCIRI model, was inhaled 2.4% sevoflurane for 3 h. Basso Beattie Bresnahan scoring method was used to evaluate neuromotor function and TUNEL staining to observe apoptosis. Evans blue ( EB) was used to de-termine blood-spinal cord barrier ( BSCB) permeabili-ty; real-time qPCR to detect miR-199a-5p content;Western blot to measure the levels of caspase-9 and Bcl-2 in spinal cord tissues. Results Compared with sham group, the score of neuromotor function in I/R group decreased, cell apoptosis rate increased, BSCB permeability increased, miR-199a-5p expression de-creased, caspase-9 expression increased, and Bcl-2 expression decreased; compared with I/R group, the neurological motor function score of SEVO+I/R group increased, the apoptotic rate decreased, the BSCB per-meability decreased, the expression of miR-199a-5p increased, the expression of caspase-9 decreased, and the expression of Bcl-2 increased. Conclusion Sevoflurane pretreatment may reduce BSCB permeabili-ty and neuronal apoptosis by up-regulation of miR-199a-5p and protection of SCIRI in rats.
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Aim To observe the effect of icariside Ⅱ(ICS Ⅱ)on cardiomyocyte apoptosis in spontaneously hypertensive rats (SHR)and to explore its possible mechanism. Methods Thirty male 13-week-old SHRs were randomly divided into model group,ICS Ⅱ low, medium,high and positive drug group (n = 6),ho-mologous male Wistar-Kyoto rats as control group (n =6). After a week of adaptive feeding,ICS Ⅱ low,me-dium and high dose groups were given ICS Ⅱ 4,8,16 mg · kg - 1 (ig,qd),and the positive drug group was given losartan 20 mg·kg - 1 . At the same time,the WKY and SHR group were given equal volume double distilled water. After 12 weeks of administration,the blood pressure was measured in rats. Then,the rats were sacrificed and the left ventricles were separated in order to calculate the left ventricular mass index. HE staining was used to observe the pathological changes of the left ventricle,and the apoptosis of the left ventricu-lar myocardium was detected by TUNEL staining. The expressions of Bcl-2 and Bax mRNA in left ventricle were detected by real time RT-PCR,and Bcl-2,Bax and cleaved-caspase-3 protein expressions were detec-ted by Western blot. Results Compared with WKY group,the blood pressure and left ventricular mass in-dex increased in SHR group (P < 0. 05),and the my-ocardial cell arrangement was disordered and the cell hypertrophy and apoptosis were obvious,accompanied by rupture of filament ;the level of Bax mRNA was up-regulated (P < 0. 05),and Bcl-2 mRNA was down-regulated (P < 0. 05 );the expressions of Bax and cleaved-caspase-3 protein were up-regulated (P <0. 05),and the level of Bcl-2 protein was down-regu-lated (P < 0. 05 ),and the ratio of Bax / Bcl-2 in-creased (P < 0. 05). Compared with SHR group,the blood pressure and left ventricular mass index de-creased in ICS Ⅱ middle,high group and the positive drug group (P < 0. 05);moreover,the arrangement of myocardial cells became more orderly,the cell hyper-trophy and the apoptosis of myocardial cells were im-proved;the level of Bax mRNA was down-regulated and Bcl-2 mRNA was up-regulated (P < 0. 05);the expression of Bax and cleaved-caspase3 protein were down-regulated and the level of Bcl-2 protein was up-regulated (P < 0. 05 );the ratio of Bax / Bcl-2 de-creased (P < 0. 05). Conclusions ICS Ⅱ can im-prove the left ventricular cardiomyocytes apoptosis in SHR,and its mechanism is related to the decrease of blood pressure and the inhibition of mitochondrial ap-optosis pathway.
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Background and purpose:Dihydrofolate reductase (DHFR) is expressed highly in platinum-resis-tant ovarian cancer. This study aimed to explore the relationship between the silence ofDHFR gene and platinum drug resistance in ovarian cancer, and lay the foundation for the treatment of platinum-resistant ovarian cancer.Methods:To design targeting hairpin siRNA ofDHFR gene, the optimal siRNA silent sequence was selected, and lentiviral vector carryingDHFR gene was constructed successfully, named DHFR-pGCSIL-SKOV3 cell. Flow cytometry was used to detect the cell apoptosis of DHFR-pGCSIL-SKOV3 cells, pGCSIL-SKOV3 cells and SKOV3 cells incubated in various concentrations of cisplatin (2.5, 5.0, 10.0 and 20.0 μg/mL) at different time points (24, 48 and 72 h), and cell cycle changes of these cells at IC50 cisplatin concentration (4.4 μg/mL). High performance liquid chromatography was used to test intracellular concentration of cisplatin at different induction concentration of cisplatin (2.5, 5.0 and 7.5 μg/mL) and various time points (24 and 48 h). Ultrastructural changes of these cells at concentration of cisplatin IC50 (4.4 μg/mL) were observed by transmission electron microscope.Results:After annealing double-strand nucleotide was connected to pGCSIL/GFP vector, sequencing result was correct. SKOV3 cell were transfected with virus particles followed by Western blot detection of interference effect. Flow cytometry was used to detect apoptosis in three groups of cells, and increased apoptosis rate was found at the raised cisplatin concentration (2.5, 5.0, 10.0 and 20.0 μg/mL) at 24, 48 and 72 h in DHFR-pGCSIL-SKOV3, pGCSIL-SKOV3 and SKOV3 cells. The apoptosis rate in DHFR-pGCSIL-SKOV3 was signiifcantly higher than that in pGCSIL-SKOV3 and SKOV3 cells at 24 and 48 h (P<0.05). Flow cytometry was adopted to test cells cycle of 3 groups at different time period under IC50 cisplatin concentration (4.4 μg/mL), the results indicated that G0/G1 phase cell rate of DHFR-pGCSIL-SKOV3 was much more than the others, of which G2/M and S phase cell rates were on the contrary. While at 72 h, 3 groups were mainly G2/M and S phase cell rates, DHFR-pGC-SIL-SKOV3 was lower than the others. High performance liquid chromatography method was used to detect intracellu-lar cisplatin concentration at 24 and 48 h after the cells were incubated at various concentrations of cisplatin (2.5 and 5.0μg/mL). The results showed the intracellular cisplatin content of DHFR-pGCSIL-SKOV3 cell was signiifcantly higher than that of pGCSIL-SKOV3 and SKOV3 cells. However, after incubation at cisplatin concentration of 7.5 μg/mL, the intracellular cisplatin content of DHFR-pGCSIL-SKOV3 cell was signiifcantly lower than that of pGCSIL-SKOV3 and SKOV3 cells at 24 h, while higher than pGCSIL-SKOV3 and SKOV3 cells at 48 h (P=0.034,P=0.014). We observed ultrastructural changes of three different cell lines induced by IC50 cisplatin concentration(4.4 μg/mL) at different time points by the electron microscope. We found that the microiflaments were increased and gathered together and mitochondrial structure was also changed obviously without the drug. However, there was rare microiflament in three groups of cells at 24 and 48 h, while at 72 h, obviously increased inordinate microiflaments were observed.Conclusion:We successfully constructed pGCSIL lentivirus interference carrier carryingDHFR gene. The research indicates that down-regulation ofDHFR gene is related to cisplatin drug resistance in ovarian cancer. The results laid the foundation for us to investigate the molecular mechanisms of multidrug-resistance in tumor.
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Objective To investigate the effects of hypoxic preconditioning on learning and memory and the possible protective mechanism in mice with cerebral ischemia-reperfusion injury.Methods Healthy adult male Kunming mice were randomly divided into five groups by Random number table:normal group( N group),hypoxic preconditioning group (HPC group),sham operation group (C group),ischemia-reperfusion group(O group),hypoxic preconditioning and ischemia-reperfusion group(HPC+O group).HPC+O group were given hypoxic preconditioning before 24h of ischemia-reperfusion.The escape latency was detected by Morris water maze and the neuron apoptosis of CA 1 area of hippocampal was determined by immunofluores-cence techniqueR.e sults The escape latency in HPC+O group on the second,third and fourth day of MWM was (39.92±4.52)s,(30.98±2.44)s,(19.69±4.27)s,and significantly lower than that in O group((54.35± 3.66)s,(46.31±4.81)s,(36.81±3.86)s).Mice in HPC+O spent longer time in the target quadrant than that in O group((36.44±5.33)%and(24.5±2.59)%,respectively, P<0.05).Immunofluorescence showed that the apoptotic ration of nerve cells in hippocampal CA 1 was significantly lower than that in O group ( 11.7 ± 0.14 and 1.35±0.14, P<0.05).Conclusion Hypoxic preconditioning can increase hippocampal CA1 neurons hypoxia tolerance of ischemia reperfusion injury in mice,and reduce the incidence of neural cell apoptosis.
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Aims To study the effects of diterpenoid pekinenal of Euphorbia pekinensis Rupr. on cell prolif-eration, cell cycle phase and apoptosis of hepatoma SMMC-7721 cells and to probe into its anti-cancer mechanisms. Methods MTT assay was used to inves-tigate the effect of pekinenal on proliferation of SMMC-7721 cells; TUNEL method, Annexin V/PI staining and electron microscopy were employed to observe the cell apoptosis; Flow cytometry was applied to analyze the distribution of cell cycle. Results Proliferation of SMMC-7721 cells was markedly inhibited by pekinenal in a dose-dependent manner; Annexin V/PI staining showed that with the increase of pekinenal concentra-tion, apoptotic rate of SMMC-7721 cells increased sig-nificantly, compared with control group, the difference has significant statistical significance ( P < 0. 01 ) . TUNEL method test results showed that different con-centrations of pekinenal in SMMC-7721 cells could in-duce liver cancer cell apoptotic and apoptotic index ( AI) increased significantly ( P <0. 01 ) with the in-crease of drug concentration. Compared with control group, electron microscope found that after the treat-ment, hepatocyte mitochondrial swelling, endoplasmic reticulum expansion, cytoplasm inclusion body forma-tion, part of the nucleus apoptosis, and the more obvi-ous apoptosis appeared with the increase of drug con-centration. Flow cytometry analysis showed that differ-ent concentrations of pekinenal could all make the cell block in S phase. Conclusion Pekinenal has an obvi-ously inhibitory effect on the human liver cancer cells, and there is significant concentration dependence; Pe-kinenal probably inhibits cancer cell DNA synthesis for the human liver cell cycle arrest in S phase and inhibits the proliferation . It plays a role in liver cancer inhibi-tion by inducing liver cancer cells apoptosis, etc.
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Aim Toinvestigatetheinducementeffect of isatin on apoptosis of breast cancer cell line MCF-7 , andexploreitsdetailedmechanism.Methods MCF-7 cell lines were exposed to isatin at different concentra-tions(0,50,100,200 μmol·L-1 )for 48 h.Apop-totic features were demonstrated by nuclei staining with Hoechst 33258.Bcl-2,Bax and p53 mRNA were ana-lyzed by RT-PCR.Caspase-9 activation and mitochon-drial depolarization were assayed by flow cytometry. Bcl-2,Bax,p53 and cytochrome c proteins were ana-lyzedbyWesternblot.Results Isatininducesapopto-sis of MCF-7 cells.Furthermore,Bcl-2 expression was decreased and the ratio of Bcl-2 to Bax was significant-ly decreased by isatin.While,p53 expression relative-ly decreased.The mitochondrial transmembrane poten-tial was markedly reduced and the release of cyto-chrome c into the cytosol was increased after treatment with isatin.Simultaneously,caspase-9 was activated. Conclusions Isatinsignificantlyinducedtheapopto-sis of MCF-7 cells in vitro.These results strongly sug-gest that the p53 dependent mitochondrial pathway is involved in apoptosis.
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Aim To investigate the roles of FFJ-5 in human breast cancer MCF7 cells and drug-resistant MCF7/DOX cells and to explore its mechanisms. Methods MTT assay was used to detect the effect of FFJ-5 on MCF7 and MCF7/DOX cell proliferation and sensitivity of doxorubicin in MCF7/DOX cells.West-ern blot was used to investigate the effect of FFJ-5 on expression of EGFR,p-EGFR,Akt,p-Akt,PKM2, cleaved caspase-3,cleaved PARP and P-gp.DNA lad-der analysis was performed to determine the effect of FFJ-5 on genomic DNA.RT-PCR was performed to de-tect the influence of FFJ-5 on multidrug resistance gene MDR1 mRNA levels.Results The results showed that FFJ-5 inhibited the growth of MCF7 ,inhibited the expression and activity of EGFR and Akt,and conse-quently reduced the expression of PKM2 in MCF7 cells;FFJ-5 activated caspase-3 and induced genomic DNA fragmentation;FFJ-5 also inhibited the growth of MCF7/DOX cells and enhanced the anti-tumor activity of doxorubicin in MCF7/DOX cells.Conclusion The results suggest that FFJ-5 could inhibit MCF7 cell growth and induce MCF7 cell apoptosis through inhibi-tion of EGFR-Akt-PKM2 pathway and activation of ap-optosis-related factors caspase-3 , meanwhile FFJ-5 could also reverse the resistance of MCF7/DOX.
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Objective To study the effect of knockdown A20 expression on the proliferation, apoptosis and migra-tion of MCF-7 cells and to evaluate the potential value of the A20 gene as the therapeutic target of breast cancer. Methods Synthesized siRNA targeted to A20 gene or negative control siRNA were transfected into MCF-7 cells by using lipofectamine 2000. CCK8 assay, Annexin V and 7-AAD double staining cytometry, Transwell assay were performed to investigate the effect of knockdown A20 mRNA expression on the proliferation, apoptosis, migration of MCF-7 cells, respectively. Results It can inhibit the proliferation and migration as well as promote the apoptosis in MCF-7 cells by knockdown A20 mRNA expression. Conclusion A20 gene plays an important role in the prolif-eration, apoptosis and migration of MCF-7 cells and it could be a potential therapeutic target of breast cancer.
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Aim To investigate the possible mecha-nisms of the levels of NO decrease induced apoptosis in human placental trophoblast cells. Methods Human placental trophoblast cells ( HTR-8 ) were cultured in 5 ml DMEM-F12 culture medium with 37℃ 5% CO2 . Then, the old culture medium was discarded and re-placed with 10,100,500,1 000 μmol·L-1 L-NAME, and the group without L-NAME was set as the control group, cultured for 48h. The effects of L-NAME on the survival of cells were detected by methylthiazolyldiphe-nyl tetrazolium bromide ( MTT); the content of NO in cells was tested by nitrate reductive enzymatic;trans-mission electron microscopy, flow cytometry analysis and Annexin-V FITC dyeing were used to test the effects of L-NAME on apoptosis in HTR-8 cells;restore Fe3+ colorimetric assay was applied for detection of to-tal antioxidant capacity ( T-AOC ) , xanthine oxidase for detection of superoxide dismutase ( SOD) activity, and thiobarbituric acid colorimetry for determination of content of MDA. Results Compared with the control group, the survival rate of HTR-8 cells and the levels of NO in 100,500,1 000 μmol·L-1 L-NAME group were significantly reduced(P<0.05,P<0.01). Flow analysis and Annexin-V FITC staining showed that L-NAME could induce cell apoptosis in a dose-dependent manner. The number of cell apoptosis was negatively correlated with the content of NO ( r = -0.5210 ) in HTR-8 cells. Transmission electron microscopy results showed that compared with the control group, the ex-perimental group's cell nucleus shape was irregular, nuclear pyknosis in irregular shape, the chromatin ag-glutination or side the collection, mitochondrial swell-ing or enrichment, crest fracture or dissolved, even vanished, forming the vacuole, especially in 100 μmol ·L-1 L-NAME group, the apoptotic bodies obviously appeared. At the same time, T-AOC, SOD levels in HTR-8 cells decreased ( P <0.05 ) , and the MDA content increased ( P<0.05 ) . The number of cell ap-optosis was negatively correlated with the level of T-AOC ( r= -0.3212 ) , SOD ( r= -0.2779 ) in HTR-8 cells , while positively correlated with the content of MDA(r=0.2807). Conclusion Oxidative stress may play an important role in the levels of NO decrease in-duced apoptosis in human placental trophoblast cells.
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Objective To study the expression of Livin and its relalionship with expression of p53 in small cell hmg cancer(SCLC).Methods Immunohistochemical S-P method was used to detect the ex-pression of Livin and p53 protein in 30 SCLC tissues and 16 para-cancerous lung tissues.Results Livin protein was expressed in 17 of 30 SCLC tissues(56.67%),but Livin protein showed low levels in para-can-cerous lung tissues(12.50%),P＜0.01.There was no significant correlalion between positive Livin protein expression and age,sex,TNM staging,lymph node metastasis and lumor diameter(P＞0.05).p53 protein was expressed in 14 of 30 SCLC tissues(46.67%),but p53 protein was no expressed in para-caneerous lung tissues,P＜0.01.The expression of Livin protein was positively related to the expression of p53 protein(P＜0.01).Conclusions The aberrant expression of Livin may be a new target for diagnosis and gene treatment of SCLC.The aberrant expression of Livin and p53 may play synergetic role in process of carcinogenesis of SCLC.