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Objective:To study the gene expression of nuclear factor erythroid-2-related factor 2 (Nrf2), glutathione-S-transferase (GST) and interleukin-1 β (IL-1β) in A549 cells exposed to hyperoxia and cell apoptosis after siRNA interference with Nrf2.Method:Normal A549 cell lines were assigned into normoxia+siRNA group, normoxia+control group, hyperoxia+siRNA group and hyperoxia+control group according to whether siRNA interference was used and the exposure environment (normoxia/hyperoxia). The hyperoxia environment contained 95%O 2 and 5%CO 2. The levels of mRNA expression of Nrf2, GST and IL-1β were detected using quantitative real-time polymerase chain reaction (qRT-PCR). Flow cytometry was used to examine cell apoptosis of the hyperoxia+control group and hyperoxia+siRNA group at different time points. Analysis of variance (ANOVA) was used to test the relative gene expression and apoptosis of A549 cells. Result:(1) Compared with the normoxia+control group, the expression of Nrf2 and GST in the hyperoxia+control group was significantly increased ( P<0.05), and the expression of IL-1β was significantly decreased ( P<0.05); the expression of Nrf2 and GST in the normoxia+siRNA group decreased significantly ( P<0.05), while the expression of IL-1β increased significantly ( P<0.05). (2) Compared with the normoxia+siRNA group, Nrf2 expression in the hyperoxia+siRNA group showed no significant changes ( P=0.230), GST expression increased slightly ( P=0.057), and IL-1β expression decreased slightly ( P=0.112). (3) Compared with the hyperoxia+control group, the expression of Nrf2 and GST in the hyperoxia+siRNA group decreased significantly ( P<0.05), and the expression of IL-1β increased significantly ( P=0.042). (4) Compared with the hyperoxia+control group, the apoptosis of A549 cells in the hyperoxia+siRNA group increased significantly at 24 h, 48 h and 72 h ( P<0.05). Conclusion:After interfering with Nrf2, siRNA may regulate the expression of GST and IL-1β, preventing oxidative stress, reducing inflammatory response and inhibiting apoptosis.
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ObjectiveTo investigate the effect of intrathecal injection of TRPV3-siRNA lentivirus on bone cancer pain(BCP) behaviors in rats.Methods40 female SD rats successfully received intrathecal catheter implantation and without motor dysfunction were randomly divided into 4 groups (n=10 in each group):Sham group (S),BCP group (B),negative control lentivirus group (C) and TRPV3-siRNA lentivirus group (T).Group B,C and T were induced bone cancer pain by intra-right-femur inoculation of Wallker 256 cells,while rats in group S were injected of inactivated cell.Rats in group T were intrathecally treated with 5 μl TRPV3-siRNA lentivirus while rats in group C received 5 μl negative lentivirus on 1~6 d after surgery.All the rats received pain behaviors including paw withdrawal thermal latency(PWTL) and paw withdrawal mechanical threshold (PWMT) at 1 d before BCP and 1,3,6,9,12,15,18 and 21 d after BCP.L4~L6 spinal cords were reserved for RT-PCR and Western Blot.ResultsCompared with group S,PWTL and PWMT of group B were decreased (P0.05).The results of RT-PCR and Western blot demonstrated that the expression of TPPV3 in group T was decreased compared with that in group C(P<0.05).ConclusionIntrathecal injection of TRPV3-siRNA lentivirus can inhibit the expression of TRPV3 and thus alleviate symptom of PWTL,but not PWMT.
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Objective To investigate the effect of silencing Notch1 gene by RNA interference on the proliferation,apoptosis and Akt/mTOR signaling pathway in clear renal cell carcinoma.Methods The optimal segment targeting Notch1 gene was designed and transfected into 786-O cells by Lipofectamine TM2000.The Notch1 mRNA and protein were detected by RT-PCR and Western blot.The proliferation rate of 786-O cells was evaluated by MTT and the variation of apoptosis was measured by TUNEL.The protein expression level of apoptosis-related protein Bcl-2,caspase-3,caspase-9,and signaling pathway protein Akt,p-Akt,p-mTOR,p-P70S6K were detected by Western blott.Results Notchl mRNA and protein was markedly suppressed by the siRNA targeting Notch1.Treated with 0,40,60,80,100 and 120 nmol/L of Notch1 siRNA for 24 hours,cell proliferation rates were (98.51 ± 1.33) ％,(87.34 ± 2.26) ％,(64.72 ± 3.24)％,(57.68 ±3.32)％,(31.91 ± 1.85)％ and (19.27 ±2.73)％,and the difference was statistically significant (P ＜ 0.01).Treated with 0,40,80,and 120 nmol/L of Notchl siRNA for 24 hours,apoptosis rates were (7.6 ± 3.8) ％,(21.5 ± 4.8) ％,(32.3 ± 3.5) ％,and (46.3 ± 4.7％),the difference was statistically significant (P ＜ 0.05).Decreased expression of Akt signaling pathway proteins p-Akt,p-mTOR,p-70S6K and apoptosis-related protein Bcl-2,procaspase-3 was detected,but no change in the total protein of Akt.Conclusions Depletion of Notch1 gene could inhibit cell growth and induce apoptosis in 786-O cell line.It inhibits Akt/mTOR signaling pathway by dephosphorylated.
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Hydrogen sulphide is an endogenous inflammatory mediator produced by cystathionine-γ-lyase (CSE) in macrophages. To determine the role of H2S and macrophages in sepsis, we used small interference RNA (siRNA) to target the CSE gene and investigated its effect in a mouse model of sepsis. Cecal ligation puncture (CLP)-induced sepsis is characterized by increased levels of myeloperoxidase (MPO) activity, morphological changes in liver and pro-inflammatory cytokines and chemokines in the liver and lung. SiRNA treatment attenuated inflammation in the liver and lungs of mice following CLP-induced sepsis. Liver MPO activity increased in CLP-induced sepsis and treatment with siRNA significantly reduced this. Similarly, lung MPO activity increased following induction of sepsis with CLP while siRNA treatment significantly reduced MPO activity. Liver and lung cytokine and chemokine levels in CLP-induced sepsis reduced following treatment with siRNA. These findings show a crucial pro-inflammatory role for H2S synthesized by CSE in macrophages in sepsis and suggest CSE gene silencing with siRNA as a potential therapeutic approach for this condition.
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Purpose To explore the effect of EMS1-siRNA on the growth,invasion and migration of human gastric cancer cell line MGC803.Methods It used the Colony formation assay to determine the abilities of proliferation,and flow cytometry analysis to asses cell cycle distribution and apoptosis,transwell invasion and migration experiment to determine the ability of cell invasion and migration after knockdown the expression of EMS1 in MGC803.Results These results suggested that EMS1 gene down-regulated have no affect on cell cycle and cell apoptosis,but the ability of colony formation depressed and migration lowerd obviously (P ＜ 0.05).Conclusion The results shows EMS1 gene is related to proliferation and migration of tumor.
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AlM: To silent hypoxia inducible factor-1α ( HlF-1α) gene in malignant melanoma of the choroid cell by small interference RNA ( siRNA ) and investigate its effect on the expression of matrix metalloproteinase-2 ( MMP-2 ) in the choroid cell line human uveal melanoma cell (OCM-1) in hypoxia environment.METHODS:OCM-1 cells cultured on culture flask were divided into normal group and hypoxia group. Hypoxia group were divided into five groups: simple hypoxic group, and interference group, and negative control group, and positive control group, and liposome group. Normal group cells were cultured on DMEM culture flask with 10% FBS, 100U/mL penicillin, 100μg/mL streptomycin as well as high concentration of glucose. The cells were maintained at 37℃ in a humidified 5% CO2 incubator. Cells in good condition were selected for experiment. For hypoxia group, chemical hypoxia inducer CoCl2 was added into nutrient medium at the concentration of 100μmol/L to simulate hypoxia microenvironment. We designed and synthesised siRNA ( siRNA + negative control+positive control ) , the target sequences of the HlF-1α to transfect hypoxic malignant melanoma of the choroid cell. SiRNA including HlF-1α siRNA, β-actin siRNA and negative control group synthesized in vitro transfected hypoxic OCM - 1 cell through Lipofectamine2000. The expression of HlF-1α, MMP-2 gene and the protein were detected by RT-PCR and Western blot. RESULTS: Compared with the normal group, the expression of HlF-1α mRNA was not obviously changed (P>0. 05), but the expression of HlF-1α protein and MMP- 2 mRNA protein was significantly higher ( P0. 05).CONCLUSlON: Hypoxia status may upregulate the HlF-1α in OCM-1 cells by increasing the expression of protein. Hypoxia can also inactivate MMP-2, resulting in upregulation of MMP-2 RNA and the expression of its protein. The expression of HlF-1α and MMP-2 mRNA can be down-upregulated by transfecting OCM-1 with HlF-1α siRNA.
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AIM:To investigate the expression of Grb2-associated binding protein 2 (Gab2) in human osteo-sarcoma cells and its relationship with the invasion and metastases of human osteosarcoma cells.METHODS: The tech-nique of small RNA interference was used to transfect human osteosarcoma U2-OS cell lines.Western blotting and RT-PCR were used to detect the protein and mRNA expression of Gab2 in transfected U2-OS cells.After transfection, through chem-otaxis and invasion assays in vitro, the cell migration and invasion abilities were detected.RESULTS:After transfection, the expression of Gab2 at mRNA and protein levels in Gab2 siRNA transfected cells ( SiGab2/U2-OS) was lower than that in scrambled siRNA transfected cells ( Scr/U2-OS ) and U2-OS cells.After stimulation with epidermal growth factor ( EGF) at concentration of 10 μg/L, the migration SiGab2/U2-OS cells was significantly less than Scr/U2-OS cells and U2-OS cells ( P<0.01 ) .The number of invasion cells of SiGab2/U2-OS group was significantly lower than the other 2 control groups ( P<0.01) .CONCLUSION:Inhibition of Gab2 expression obviously attenuates the migration and invasion abilities of human osteosarcoma U2-OS cell line.
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To screen the siRNAs (small interference RNA sequences ) which specifically inhibit the gene expression of TLR2 in human monocyte-derived macrophage , and discuss their prospects on the treatment of HIV at the level of molecular immunology.Methods:We obtained the mRNA sequences of human TLR 2 gene from NCBI gene bank ,then designed three siRNAs by siDESIGNTM software.The siRNA targeting human housekeeping gene GAPDH was used as positive control.The fluorescent labeling missense siRNA sequences (NC-FAM ) was used as negative control.We collected fresh peripheral blood from healthy volunteers and isolated mononuclear cells from the blood samples.The human mononuclear macrophages were then purified from mononuclear cells by utilizing adherence method.Cationic liposome reagent Lipofectamine 2000 was used to mediate siRNAs into the human mononuclear macrophages.The levels of TLR2 mRNA expression of siRNA-transfected monocyte-derived macrophage were determined by q-PCR.Expression of TLR2 protein was determined by Western blot.Results: At 72 h after transfection ,we found that the expression of GAPDH mRNA and protein in positive control group decreased significantly.Also found there existed significant differences between each siRNA group (F=41.957,P<0.001).Compared with negative control ,the relative expression of TLR2 mRNA in all siRNAs groups decreased significantly (P<0.05 ) , and the inhibition rates were 46%, 43%, 43% by three miRNAs respectively.Western blot showed that the expression of TLR 2 protein in siRNAs groups decreased significantly compared with that of control (P<0.05 ).Conclusion: The designed siRNAs in this study could inhibit the expression of TLR 2 gene in human monocyte-derived macrophage ,indicating that mediation of TLR-2 expression by siRNA might be a novel strategy for HIV treatment from the per-spective of molecular immunology.
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Objective To investigate the effect of long hairpin RNA ( lhRNA) expression vector targeting HBV X gene ( HBx) on replication of hepatitis B virus ( HBV) and gene expression.Methods Four kinds of small interference RNAs ( siRNAs) were synthesized and lhRNA expression vectors targeting HBx were constructed.Four siRNA oligonucleotides and two lhRNA expression vectors were transfected into HepG2.2.15 cells.HBsAg, HBV DNA in culture supernatants and HBx mRNA in HepG2.2.15 cells were detected by time-resolved immunofluorometric assay, real-time quantitative PCR, and reverse transcription PCR, respectively.Negative sequence group or empty vector group was taken as the control.Independent-samples t test was performed to evaluate the inhibition effect on replication of HBV and gene expression. Results Compared with the negative control, HBsAg, HBV DNA level in culture supernatants and HBx mRNA in HepG2.2.15 cells were significantly decreased after siRNA-1 and siRNA-4 transfected at high concentrations (60 nmol/L or 90 nmol/L) (P<0.05), especially the HBsAg and HBV DNA levels in the siRNA-1 transfection group, which were significantly decreased at 24, 48 and 72 h after transfection ( P<0.05 or P <0.01 ) . Two lhRNA expression vectors ( pMD-HBxlh1 and pMD-HBxlh4 ) were successfully constructed and transfected into HepG2.2.15 cells, HBsAg and HBV DNA level in transfected cells was significantly lower than those in negative control (P<0.05).Conclusion The novel siRNA-1 is confirmed to target HBx gene and lhRNA expression vector targeting HBx can effectively inhibit the replication of HBV and expression of HBV gene.
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Objective To explore the effect of the gene silencing of phosphatidic acid-preferring phospholipase A1 (PA-PLA1) on insulin secretion in mouse insulin-secreting cell line MIN6. Methods The siRNA expression vector of mouse PA-PLA1 gene targeting was constructed using mouse PA-PLA1 mRNA sequence available in GenBank, and MIN6 cells were transfected with the vector. Fluorescence quantitative PCR and Western-blotwere applied to screen efficient RNAi-vector. After transfection with obtained efficient RNAi-vectors for 48 hours, glucose-stimulated insulin secretion experiments were conducted, and the changes of insulin secretion were examined. Results Four siRNA expression vectors of mouse PA-PLA1 gene targeting were confirmed to be successfully constructed by the analyses of enzyme cleavage and sequencing. The results of fluorescence quantitative PCR and Western blot analyses indicated that the siRNA expression vectorpGPU6-PA-PLA1-1885was the most effective RNAi-vector in the four vectors. The expression levels of the PA-PLA1 mRNA and protein of the MIN6 cells transfectedwith pGPU6-PA-PLA1-1885 decreased to 46.3% and 33.9% of that of the control, respectively, and meanwhile the insulin secretion levels of the cells decreased to 65.0% of that of the control (P < 0.05). Conclusion The gene silencing of phosphatidic acid-preferring phospholipase A1 might decrease insulin secretion in MIN6 cells.
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Background Arresting the overexpression of vascular endothelial growth factor (VEGF) will be a new approach to the inhibition of neovascularization.RNA interference (RNAi) can inhibit the expression of specific gene,and its application in eye has little interference to other gene expression.Objective This study was to investigate the effect of small interference RNA (siRNA) targeting VEGF on the expression of VEGF and retinal neovascularization in oxygen-induced retinopathy (OIR) model.Methods psi-HITM/enhanced green fluorescent protein (EGFP)/VEGF siRNA was designed and prepared in vitro.Mouse endothelioma (EOMA) were cultured in DMEM without antibiotic and divided into 5 groups.The cells were incubated in DMEM only in the blank control group;while 1 μl of LipofectamineTM 2000 + psi-HITM/EGFP,1 μl LipofectamineTM 2000 + 40,50 or 60 nmol/L of psi-HITM/EGFP/VEGF siRNA was added into DMEM in the negative control group and siRNA groups,respectively.The expression of VEGF mRNA and protein was detected by real time PCR (RT-PCR) and Western blot.The optimal effective concentration of VEGF siRNA was assessed.OIR models were established in 48 7-day-old C57BL/6J mice by raising them at an oxygen concentration of (75±2) ％ for 5 days and then to normal air.The mice were randomized into the model group,null vector group and VEGF siRNA group.1 μl of a mixture of psi-HITM/EGFP or VEGF siRNA (60 nmol/L) and LipofectamineTM 2000 was intravitreally injected,respectively,in the null vector group and VEGF siRNA group.The normal mice were used as the normal control group.Expression of VEGF mRNA and protein in the mouse retinas was detected by RT-PCR and Western blot,respectively,and FITC-dextran stretched retinal preparation was examined to evaluate the neovascularization,and retinal sections were examined to quantify the number of vascular endothelial cell nuclei extending beyond the internal limiting membrane (ILM).Results The in vitro transfection test showed that the expression of VEGF mRNA and protein in the EOMA cells was significantly different among the blank control group,negative control group and 40,50,60 nmol/L VEGF siRNA groups (F =148.890,P ＜ 0.001; F =306.960,P ＜ 0.001),and the expression of VEGF mRNA was lower in different concentrations of VEGF siRNA groups than that in the blank control group (t=73.950,119.890,156.480,all at P＜0.001).Also,the expression of VEGF protein was less in different concentrations of VEGF siRNA groups than that in the blank control group (t =15.452,23.344,42.119,all at P＜0.001).The optimal inhibitory concentration of VEGF siRNA was 60 nmol/L.In vivo study determined that compared to the model group and null vector group,the non-perfusion zones and neovascular net in the retina were decreased,and the number of vascular endothelial cell nuclei extending beyond the ILM was less in the VEGF siRNA group.The relative expression level of VEGF mRNA in the retinas was 1.23±0.18,4.02±0.16,3.98±0.19 and 1.98±0.12 in the normal control group,model group,null vector group and VEGF siRNA group,respectively,with a significant difference among them (F=369.780,P＜0.001),and the relative expression levels of VEGF mRNA in the model group and null vector group were higher than that in the normal control group (t=37.880,37.336,both P＜0.001),and the expression of VEGF mRNA in the VEGF siRNA group declined by 50.8％ (t=10.183,P＜0.001).The difference in the expression levels of VEGF protein also was assayed among the various groups (F=408.980,P＜0.001),and VEGF level in the retina was lowered by 68.0％ in the VEGF siRNA group compared to the model group (t =11.473,P＜0.001).However,VEGF level in the VEGF siRNA group remained at a high level in comparison with the normal control group (t =2.422,P＜0.001).Conclusions Intravitreal injection of VEGF siRNA can attenuate retinal neovascularization by effectively downregulate the expression VEGF mRNA and protein in the retina.
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Background and purpose:The pro-oncogene Bmi-1 is a member of the polycomb-group family, can regulation of the proliferation and self-renewal of normal and tumor stem cells. In recent years, Bmi-1 has been found that it is overexpressed in varieties of human malignant tumors. The study aimed to observe the effects of Bmi-1-siRNA on the growth capacity of lung cancer cell line A549 in vivo and in vivo, and explore its mechanism. Methods:The most effective one as a target sequence was chosen from four Bmi-1 siRNA sequences which were designed by our lab, and one random sequence was chosen as a negative control. In short, the chemically synthesized siRNA and control sequences were connected to a retrovirus expressing vector, pSUPERretro-Neo plasmid, and then transfected into A549 cells. The stably transfected cells were cultured and passed. The level of mRNA and protein of Bmi-1 in A549 cells were assessed by RT-PCR and Western blot respectively. The proliferations of A549 cells in vivo was analyzed with MTT, trypan blue exclusion and plate colony forming methods. Flow cytometry was used for cell cycle analysis. The potency of tumorigenesis was observed in nude mouse through hypodermic inoculation of A549 cells. The expressions of cyclin D, p21/27, p-AKT and PTEN were analyzed by Western blot. Results:Compared to A549-ctr and A549-wt cells, Bmi-1 mRNA and protein levels all signiifcantly reduced in A549-Bmi-1-siRNA cells. Bmi-1-siRNA inhibited the growth, colony formation in vitro and tumorigenesis in vitro of A549 cells, and the interference cells cell cycle arrested in G1 phase. In A549-Bmi-1-siRNA cells, p-AKT and cyclinD1 expression were down-regulated while p21/p27 and PTEN were up-regulated. Conclusion:Silencing Bmi-1 gene inhibits the proliferation of A549 cells through G1 phase arrest, which involves the downregulation of cyclin D/p-AKT and upregulation of p21/p27/PTEN.
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Objective To explore the effect of hyperoxia on A549 cells suppressed with surfactant protein A (SP-A) suppressed by small interference RNA(SiRNA)-mediated gene silencing,and discuss the function of SP-A in hyperoxic lung injury.Methods A549 cells were gained by serial sub cultivation in vitro and randomly divided into 2 groups,silenced of SP-A group and the control group.A549 cells were transfected with synthetic SP-A sequence-specific SiRNA by Lipofectamine 2000,continuously exposed to hyperoxia(950 mL/L 02,50 mL/L CO2).After exposure to hyperoxia for 48 hours,72 hours and 96 hours,total protein and culture supernatant were gained.SP-A protein was detected by Western-blot,the capacity of proliferation was detected by methyl thiazolyl tetrazolium,and thiobarbituric acid colorimetric method was used to detect the malondialdehyde (MDA) in culture supernatant.Results Sequence-specific SiRNA targeted SP-A2 and significantly down-regulated its expression in A549 cells.Compared with the control group in hyperoxia,the expression of SP-A significantly decreased after 48 hours,72 hours in the silenced group (all P ＜ 0.05),and the capacity of proliferation in A549 cells silenced by SP-A were obviously decreased after 48 hours,72 hours and 96 hours(all P ＜0.05).But there was no significant difference in the MDA in culture supernatant between 2 groups(all P ＞ 0.05).Conclusions The capacity of resisting hyperoxia decreased in A549 cells silenced by SP-A,which indicates that SP-A can protect hyperoxic lung injury.
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Dengue virus infection has become a global threat affecting around 100 countries in the world. Currently, there is no licensed antiviral agent available against dengue. Thus, there is a strong need to develop therapeutic strategies that can tackle this life threatening disease. RNA interference is an important and effective gene silencing process which degrades targeted RNA by a sequence specific process. Several studies have been conducted during the last decade to evaluate the efficiency of siRNA in inhibiting dengue virus replication. This review summarizes siRNAs as a therapeutic approach against dengue virus serotypes and concludes that siRNAs against virus and host genes can be next generation treatment of dengue virus infection.
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Animales , Humanos , Dengue , Terapéutica , Virus del Dengue , Genética , Interferencia de ARN , ARN Interferente Pequeño , Genética , Usos TerapéuticosRESUMEN
Objective To investigate the transfection efficiency of combination of ultrasound (US) microbubbles (MBs) mediated liposome small interference RNA (siRNA) to human and rat retinal pigment epithelium (RPE) cells. Methods Human and rat RPE cells and siRNA were incubated in 24-well plates (2×10~5/well and 1×10~5/well, respectively). The cells were devided into 5 groups: siRNA+US, siRNA+MBs+US, siRNA+L (liposome), siRNA+L+US, siRNA+L+US+MBs. After 12 h, transfection efficiency was observed with fluorescence microscopy and flow cytometry. Results US or ultrasound targeted microbubbles destruction without liposome-mediated could not promote siRNA transfection efficiency to human and rat RPE cells. The transfection efficiency of human and rat RPE cells significantly decreased in the siRNA+L+US+MBs group, but increased in siRNA+L+US group. Conclusion Ultrasonic irradiation can promote lipid-mediated siRNA transfected human RPE cells.
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Objective To investigate the effects of a proliferation-inducing ligand(APRIL)gene silencing by small interfering RNA(siRNA)on cell cycle and proliferation of colon carcinoma SW480 cells.Methods The siRNA plasmid vector targeting APRIL gene,named as siRNA-APRIL,was transfected into SW480 cells,transfected with scrambled vector as a nontargeting control and nontransfected group as another control.APRIL mRNA and protein expression were examined by real-time PCR and Western blot,respectively.Cell proliferation activity was analyzed by cell counting kit-8(CK-8),cell cycle was detected by flow cytometry,and p21 together with p27,two important regulatory genes in cell cycle,were measured by RTPCR.Results Compared with nontargeting control and nontransfected control,APRIL expression was inhibited significantly at both mRNA and protein level by siRNA-APRIL being transfected in SW480 cells(P ＜0.05).Cell proliferation ability was drastically repressed after siRNA-APRIL being transfected at 48 h,72 h and 96 h(P ＜ 0.05).After transfected 48 h,the percent of Go/G1 phase cell was significantly increased,S and G2/M phase cell were significantly decreased,the number of cell in apoptosis was increased and the expression of p21 and p27 mRNA were up-regulated(P ＜ 0.05).There was no significant difference when compared the two control groups each other(P ＞ 0.05).Conclusion siRNA-APRIL can effectively knockdown the expression of APRIL gene in SW480 cells,moreover,it can inhibit the cell proliferation and induce G0/G1 phase cell cycle arrest,which occurrence may involve in upregulation the mRNA expression of p21 and p27.
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Aim According to various target sites of HLA-E mRNA,to design and synthesize 3 pieces of HLA-E siRNA chain,to compare quantitatively their efficiency of silencing gene in BEL-7402 with HLA-E(+)in order to select the dominant siRNA.Methods The hepatocarcinomal BEL-7402 cells,induced by 5×10~5 IU·L~(-1) IFN-γ,expressed HLA-E(+) and was pured by flow cytometry selecting as target cells for research.3 pieces of specific siRNA(A,B,C group)were designed and chemically synthesized,then the concentration of which(0.1 mmol·L~(-1))was respectively transfected through Lipofectamin 2000 into target cells.After 48 h,the gene silent effect on HLA-E gene in A,B and C groups was quantitatively observed by cytoimmunofluorence,flow cytometery,Western blot and real-time PCR,as well as on NK cytotoxicity to target cells tested by NK killing rate.Results Compared with those of control or non-specific siRNA group,HLA-E antigen,protein product,HLA-E mRNA and HLA-E molecule on cell surface were statistically down-regulated in A,B,and C group(P<0.01),whose were silenced more (above 90%) in B or C group than in A group (P<0.01).The NK killing rate in A,B and C groups was dominantly improved(P<0.01),which in B or C group was higher than in A group (P<0.01).Conclusion The targeted siRNA can specifically and high-efficiently silence HLA-E expression in hepatocarcinomal cells,and may keep them from immunoescape through non-classic HLAⅠ pathway to imply new strategy for hepatocarcinomal gene-immunotherapy.
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Objective To study the inhibition of tumor necrosis factor-alpha(TNF-α)cytokine expression of BV-2 cells induced by hypoxia-reoxygenation injury by siRNA targeting TLR4 gene via the RNAi mechanisms.Method BV-2 mouse microglial cell line was cultured in six-well plates and randomly divided into group N(nor-mal group),group H(hypoxia-reoxygenation),group T(hypoxia-reoxygenation+TLR4-siRNA transfected group),group C(hypoxia-reoxygenation+pEGFP-H1/control-siRNA transfected group)and group B(hypox-ia-reoxygenation+pEGFP-H1 transfected group).Group H,group T,group C and group B were cultured in hy-poxia condition for 3 h followed by reoxygenation for 24 h.The plasma was transfected into BV-2 cells mediated by lipofectamine 2000.The efficiency of transfection were detected by flow cytometry to observe the expression of EGFP.RT-PCR method was used to detect the level of mRNA of TLR4 or NF-кB p65.Westem blot methed was used to test the expression of TLR4 protein.and ELISA was used to test the level of TNF-α in the supernatants.Analysis of variances was used for statistical analysis.Results The expression of EGFP gene waa;(67.58±7.16)% after transfection by flow cytometry analysis.Compared to group N,the TLR4 mRNA,NF-кB p65 mR-NA,TLR4 protein level and the TNF-α quantity in group H,group T,group C and group B increased after the hy-poxia-reoxygenation treatment(P＜0.01).While the expression of the TLR4 mRNA,NF-кB p65 mRNA,TLR4 protein level and the TNF-α quantity in the group T down-regulated compared to group H,group C and group B(P＜0.01).And there were no changes in group C,group B and group H about observation index(P＞0.05).Conclusions The siRNA targeting TLR4 mRNA could inhibit the inflammatory reaction released by BV-2 cells in-duced by hypoxia-reoxygenation stimulation.
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Double-stranded RNA (dsRNA) induces a sequence-specific silencing in eukaryotic cells. This silencing process beggins when long dsRNA is cleaved to 21 to 26 long small RNA by means of the RNAse III-type enzyme Dicer. These small dsRNA are included into silencing effector complexes, that are targeted to complementary sequences. Small RNA dependent gene silencing can be achieved by distinct mechanisms based depending mainly on the nature of target sequences and on the proteins present in the effector complex. The route of interference RNA (RNAi) begins when Dicer yields small interference RNA (siR-NA) that bind to complementary mRNA for its degradation, forming the RISC complex. siRNA are naturally formed from transposons and dsRNA viruses during its replication, as well as from other bidirectional transcribed repetitive sequences. Some of the enzymes thar are part of the RNAi machinery, including Dicer, are encoded by multigene families in many species, that also play a role in other mechanisms of RND-dependent gene silencing. MicroRNA's (miRNA) are other small RNA's that can induce gene silencing at the mRNA level. These are formed in a general manner when Dicer process hairpin structures resulting from the transcription of non-coding sequences from plant and animal genomes. miRNA's are integrated into a RISC-like complex, after which, depending on their degree of complementarity with target mRNA, can either repress translation or induce mRNA degradation. miRNA-dependent silencing is essential for the development of multicellular organisms. Artificial RNAi induction by means of siRNA or miRNA is being used as a tool to inactivate gene expression in culture cells and in living organisms. This review focuses on the progress in the understanding of the mechanisms involved in gene regulation by RNA in animals and details some current efforts to apply theses phenomena as a tool in research and in the therapeutic of human diseases.
El RNA de doble cadena puede inducir un silenciamiento secuencia-específico en eucarionte. Este proceso de silenciamiento se inicia cuando el RNAdc largo es procesado a RNA pequeño de 21 a 26 nucleótidos mediante la enzima RNAsa III Dicer. Estos RNA pequeños se incorporan a complejos efectores de silenciamiento, que son guiados a secuencias complementarias blanco. Existen diferentes tipos de silenciamiento, cuyas diferencias se basan principalmente en la naturaleza de la secuencia blanco y en la composición proteica de los complejos efectores. La ruta del RNA de interferencia (RNAi) se inicia cuando Dicer genera pequeños RNA de interferencia (siRNA) que se unen por complementariedad al mRNA para su degradación, utilizando el complejo RISC. De manera natural, los siRNA se originan de transposones y virus que producen RNAdc durante su replicación, así como también de otras secuencias repetidas transcritas bidireccionalmente. Algunas de las enzimas que conforman la maquinaria del RNAi como Dicer, entre otras, son codificadas por familias multigénicas en varias especies y también participan en otros mecanismos de silenciamiento mediado por RNA. Los microRNA son otros RNA pequeños que pueden inducir silenciamiento al unirse al mRNA. Éstos se generan de manera general cuando Dicer procesa estructuras de horquilla compuestas de regiones no codificantes, en genomas de plantas y animales. Los miRNA se incorporan a un complejo similar a RISC y, dependiendo de su grado de complementariedad con el mRNA blanco, pueden tener represión traduccional o bien digerir el mRNA. El silenciamiento mediado por miRNA es esencial para el desarrollo de plantas y animales. La inducción artificial del RNAi mediante siRNA o miRNA ha sido adoptada como una herramienta para inactivar la expresión génica, tanto en células en cultivo como en organismos vivos. En esta revisión se muestra el gran progreso en el entendimiento de los mecanismos que participan en la regulación génica mediada por RNA en animales y detalla algunos esfuerzos actuales para encauzar a estos mecanismos como una herramienta en la investigación y como posible terapia en enfermedades.
Asunto(s)
Humanos , MicroARNs/metabolismo , Interferencia de ARN/fisiología , ARN Interferente Pequeño/metabolismo , MicroARNs/genética , ARN Interferente Pequeño/genéticaRESUMEN
Objective To investigate the effects of siRNAs targeted protein kinase C ?(PKC?) on the proliferation and apoptosis of A549 cell line.Methods Six PKC? siRNAs were designed and chemical synthesized. Candidate PKC? siRNA was transfected into A549 cells,PKC? mRNA level was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). Then,the effects of more effective PKC? siRNAs on A549 were further investigated by using clone formation assay,Hoechst 33258 staining,propidium iodide (PI) staining,Annexin V-FITC and PI dual staining and western blot. Results Six candidate PKC? siRNAs were designed and named as No.1,No.2,No.3,No.4,No.5 and No.6 PKC? siRNA. Compared with controls,PKC? mRNA levels were all significantly downregulated and the cell proliferation was inhibited in A549 cells treated with candidate PKC? siRNAs except No.5 (P