Objective To investigate the influence of RNA interference targeting c-Jun gene on the proliferation of rat vascular smooth muscle cells (VSMCs). Methods The experiment was performed with c-Jun siRNA （c-Jun siRNA group）, control reverse sequence siRNA (control siRNA group) or no siRNA (control group). VSMCs were transfected with siRNA targeting c-Jun gene by liposome. Effects of c-Jun siRNA on mRNA and protein expressions of c-Jun were examined by RT-PCR analysis and Western blot respectively. MTT test and 3H-TdR incorporation were used to detect VSMCs proliferation. Cell cycle analysis of VSMCs in vitro was determined by flow cytometer. Results The expression levels of mRNA and protein of c-Jun in c-Jun siRNA group were significantly lower than those in control group （P＜0.05， P＜0.01). There was no significant difference between control group and control siRNA group （Pgt;0.05）. Proliferation activity of VSMCs decreased significantly in c-Jun siRNA group compared with that in control group （P＜0.05） and VSMCs was blocked in the G0/G1 phase of cell cycle significantly （P＜0.05）. There was no significant difference between control group and control siRNA group （Pgt;0.05）. Conclusion c-Jun gene silenced by RNA interference can inhibit VSMCs proliferation effectively in vitro.
Objective To construct vectors that express phosphatidylinositol-3-kinase, catalytic, beta polypeptide （PIK3cb） shRNA in eukaryon plasmid catalyzed by PI3K in rat, then test their effects on intimal hyperplasia in transplanted vein graft. Methods One hundred and fifty SD rats were randomly divided into six groups （n=25, in each group）: blank (25% Pluronic F-127), shRNA-1, shRNA-2, 1/2 （shRNA-1+shRNA-2）, negative control (pGenesil-1 scramble shRNA) and positive control （wortmannin） group. The jugular vein in rats were interpositioned autologously into the common carotid artery. shRNA and 25% Pluronic F-127 were mixed and coated around the transplanted vein in three PIK3cb shRNA groups. Every 5 samples were removed according to the time point (1, 3, 7, 14 and 28 days after operation), respectively. The thickness of intima and neointima area were calculated and analyzed by computer system. The PCNA expression was detected by Western blot and SP immunohistochemistry. Results The intimal thickness of three PIK3cb shRNA groups were lower than those in the blank group and negative control group on day 3, 7, 14, 28 after operation (P＜0.05); The neointima area in three PIK3cb shRNA groups (except shRNA-2 group on day 3, 7) began to decrease significantly from day one (P＜0.05). The protein expression of PCNA in three PIK3cb shRNA groups on day 3 after operation were decreased compared with blank group and negative group (P＜0.05). The percentage of the PCNA positive cells area in three PIK3cb shRNA groups were significantly lower than those in blank group and negative control group in each time point (Plt;0.05). There were no significant differences between blank and negative control group in different time points (Pgt;0.05). Conclusion The PIK3cb shRNA can effectively inhibit the proliferation of vascular smooth muscle cell, which may provide a new gene therapy for the prevention of vein graft restenosis after bypass grafting.
ObjectiveTo investigate the influence of EZH2 gene down-regulation by RNA interference on the proliferation and invasion of human glioma cell line U251.
MethodsThe recombinant plasmid of small hairpin RNA targeting EZH2 gene was constructed, and transfected into gioma U251 cells by electroporation. The expression of EZH2 mRNA and protein in the cells was detected by using reverse transcriptase-polymerase chain reaction and Western blot respectively; the viability of cells was determined by using methyl thiazol tetrazo1ium assay; and the invasiveness of U251 cells was tested by Transwell cabin.
ResultsThe expression levels of EZH2 mRNA in U251 cells were detected in a significantly lower proportion in the EZH2-shRNA group (0.19±0.02) than that in the untransfected group (1.13±0.05) and the control-shRNA-GFP group (1.15±0.05). The expression levels of EZH2 protein in U251 cells were detected in a significantly lower proportion in the EZH2-shRNA group (0.20±0.02) than that in the untransfected group (1.03±0.03) and the control-shRNA-GFP group (0.97±0.06). The proliferation rates in EZH2-shRNA group were significantly decreased as compared with those in the untransfected group and control-shRNA-GFP group (24 hours after transfection:60.13%±3.15%, 100.00%±9.31%, 100.03%±9.35%; 48 hours after transfection:53.01%±3.14%, 100.00%±9.13%, 99.58%±9.27%; P<0.05) and Transwell cabin suggested that the invasiveness of U251 cells was significantly decreased (46.00±2.82, 60.67±5.71, 61.00±2.48; P<0.01).
ConclusionEZH2-targeted RNA interference can reduce the proliferation and invasion of human glioma cells, which suggests that EZH2 shRNA may be a potential gene therapeutic target of human glioma.
Objective
To explore the influence on the expressions of vascular endothelial growth factor (VEGF) gene and matrix metalloproteinase-2 (MMP-2) gene in hepatocellular carcinoma of SMMC-7721 cells with RNA interference (RNAi) silencing the expression of hypoxia inducible factor-1α (HIF-1α) gene.
Methods
Firstly, constructed short hairpin RNA (shRNA) targeting for HIF-1α gene, and then transfected it to SMMC-7721 cells after combining with plasmid. The SMMC-7721 cells were divided into three groups, silencing group, negative control group, and blank control group, which were transfected with HIF-1α-shRNA-pGenesil-1 recombinant vector, shRNA-HK-pGenesil-1 recombinant vector, and pGenesil-1 vector respectively. Transfection cells were screened by the concentration of 500 μg/mL G418, and then positive and negative cell clones with transfection recombination carrier were obtained. Detected the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups with real time PCR (RT-PCR) technology, under the condition of hypoxic training 6 h, 12 h, and 24 h, as well as conventional oxygen training.
Results
There was no expression of HIF-1α mRNA at conventional oxygen condition in the 3 groups, and there was no significant difference in expressions of VEGF mRNA and MMP-2 mRNA among the 3 groups (P>0.05) at the condition of conventional oxygen training. The expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the silencing group, compared with the the negative control group and the blank control group, were obviously decreased (P<0.05) under the condition of hypoxic training (6, 12, and 24 h), while there was no significant difference between the negative control group and the blank control group at each time point (P>0.05), but the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups under every condition of hypoxic training were all higher than those of conventional oxygen condition (P<0.05). Under the condition of hypoxic training, the expressions of HIF-1α mRNA, VEGF mRNA, and MMP-2 mRNA in the 3 groups decreased over time, and there was significant difference between any 2 time points in each group (P<0.05).
Conclusion
RNAi technique can effectively silence the expression of HIF-1α mRNA of SMMC-7721 cells, and then silence the expressions of VEGF and MMP-2 mRNA, to inhibit the invasion and metastasis of hepatocellular carcinoma.
ObjectiveTo observe the influence of down-regulation of HtrA1 expression by small interfering RNA on light-injured human retinal pigment epithelium (RPE) cells.
MethodsCultured human RPE cells(8th-12th generations)were exposed to the blue light at the intensity of (2000±500) Lux for 6 hours to establish the light injured model. Light injured cells were divided into HtrA1 siRNA group, negative control group and blank control group. HtrA1 siRNA group and negative control group were transfected with HtrA1 siRNA and control siRNA respectively. The proliferation of cells was assayed by CCK-8 method. Transwell test was used to detect the invasion ability of these three groups. Flow cytometry was used to detect the cell cycle and apoptosis. The expression of HtrA1 and vascular endothelial growth factor (VEGF)-A was detected by real time-polymerase chain reaction and Western blot respectively.
ResultsThe mRNA and protein level of HtrA1 in the light injured cells increased significantly compared to that in normal RPE cells (t=17.62, 15.09; P<0.05). Compared with negative control group and blank control group, the knockdown of HtrA1 in HtrA1 siRNA group was associated with reduced cellular proliferation (t=6.37, 4.52), migration (t=9.56, 12.13), apoptosis (t=23.37, 29.08) and decreased mRNA (t=17.36, 11.32, 7.29, 4.05) and protein levels (t=12.02, 15.28, 4.98, 6.24) of HtrA1 and VEGF-A. Cells of HtrA1 siRNA group mainly remained in G0/G1 phase, the difference was statistically significant (t=6.24, 4.93; P<0.05).
ConclusionKnockdown of HtrA1 gene may reduce the proliferation, migration capability and apoptosis of light-injured RPE cells, and decrease the expression of VEGF-A.
Objective To observe the effect of RNA interference (RNAi) on HepG2 hepatic cancer cell by small interfering RNA (siRNA). Methods siRNA targeting vascular endothelial growth factor (VEGF) gene was transfected into HepG2 cells by LipofectimineTM 2000. The VEGF mRNA and protein were respectively detected by real-time quantitive PCR and Western blot, and the concentration of VEGF protein in the cell culture supertant was determined by ELISA at 48 h after culture. Results The average efficiency of siRNA transfection was (90.4±2.9)% after 6 h cell culture. The expressions of VEGF mRNA and protein in HepG2 cells could be effectively suppressed by siRNA, and the concentration of VEGF protein in the cell culture supertant was also decreased. Conclusion siRNA can knock down the expression of VEGF gene and decrease the concentration of VEGF protein in HepG2 cells.
Objective To construct the expression short hairpin RNA （shRNA） targeting gene kir2. 1 in rat myocardial cells, named pEGFP6 kir2. 1, and to observe the effects on the expression of messenger RNA（mRNA） and protein of gene kir2. 1 as well as the changes of myocardial beating rates. Methods Five RNA interference （RNAi） sites targeting the rat kir2. 1 gene was selected, designed and synthesized five pairs of oligonucleotides fragments ,annealed them to double-strand, then cloned them into the vectors containing U6 promoter,obtained the vector expressing five aim genes. Rat myocardial cells were divided into three groups： Experimental group, negative plasmid control group and normal control group. Reverse transcription-polymerase chain reaction（RT PCR） and Western-blot were carried out to detect the expression of the mRNA and protein of gene kir2.1 and the beating rates of myocardial cells were observed after 72 h. Results The expression of mRNA and protein of gene kir2. 1 of experimental group were markedly lower than that of other two control groups after 72 h（P〈0.01）. There was no statistically significant between two control groups. The beating rate in experimental group was much faster than other two control groups （P〈0.01）, remained unchanged in both negative plasmid control group and normal control group. Conclusion Plasmid pEGFP6-kir2.1 could suppress the expression of the mRNA and protein of kir2.1 and increase the rat cardiac muscle cell beats.
Objective To construct gene silence adenovirus vector targeting both transglutaminase 2 （TG2） and Mer receptor tyrosine kinase （Mertk） synchronously and detect the gene silence function of it. Methods The interfering plasmids targeting TG2 protein and Mertk protein were constructed firstly， then the H1 promoter and RNA interfering （RNAi） sequence were cut and ligated to pAdTrack for constructing pAdTrack/TG2/Mertk. The pAdTrack/TG2/Mertk was transfected into BJ5183 bacterial cells which contained pAdEasy-1， then the plasmid was detected by enzyme digestion after recovery. Adenovirus were harvested after that pAdTrack/TG2/Mertk was infected into HEK293 cells. The virus titer was measured after repeated amplification. The RAW264.7 cells were infected by pAdTrack/TG2/Mertk， pAdTrack/TG2， pAdTrack/Mertk， and pAdTrack/green fluorescent protein （GFP）， respectively. Then the expression levels of TG2 protein and Mertk protein of mouse macrophages were detected by Western blot after infection. Results The virus titer of pAdTrack/TG2/Mertk plasmid was 6.13×1010GFU/mL. The pAdTrack/TG2/Mertk plasmid which contained 2 promoters and 2 RNAi sequences was identified successfully by enzyme digestion. Compared with pAdTrack/GFP group and pAdTrack/Mertk group （there was no significant differece between the 2 groups）， the expression levels of TG2 protein of mouse macrophages which infected with pAdTrack/TG2/Mertk or pAdTrack/TG2 decreased obviously （P＜0.01）， but there was no significant difference between the later 2 groups. Compared with pAdTrack/GFP group and pAdTrack/TG2 group （there was no significant difference between the 2 groups）， the expression levels of Mertk protein of mouse macrophages which infected with pAdTrack/TG2/Mertk or pAdTrack/Mertk decreased obviously too （P＜0.01）， but there was no significant difference between the later 2 groups. Conclusion Gene silence adenovirus vector plasmid targeting both TG2 and Mertk synchronously is constructed successfully， and the pAdTrack/TG2/Mertk can reduce the expressions of TG2 protein and Mertk protein of mouse macrophages obviously.
【Abstract】 Objective The seed cells source is a research focus in tissue engineered cartilage. To observe whether the post-RNA interference (RNAi) chondrocytes could be used as the seed cells of tissue engineered cartilage. Methods Chondrocytes were separated from Sprague Dawley rats. The first passage chondrocytes were used and divided into 2 groups: normal chondrocytes (control group) and post-RNAi (experimental group). Normal and post-RNAi chondrocytes were seeded into chitosan/gelatin material and cultured in vitro to prepare tissue engineered cartilage. The contents of Aggrecan and Aggrecanase-1, 2 were measured by HE and Masson staining, scanning electron microscope (SEM), and RT-PCR. Results The histological results: no obvious difference was observed in cell number and extracellular matrix (ECM) between 2 groups at 2 weeks; when compared with control group, the secretion of ECM and the cell number increased in experimental group with time. The RT-PCR results: the expression of Aggrecan mRNA in experimental group was significantly higher than that in control group (P lt; 0.05); but the expressions of Aggrecanase-1, 2 mRNA in experimental group were significantly lower than those in control group (P lt; 0.05). The SEM results: the cell number in experimental group was obviously more than that in control group, and the cells in experimental group were conjugated closely. Conclusion The post-RNAi chondrocytes can be used as the seed cells for tissue engineered cartilage, which can secrete more Aggrecan than normal chondrocytes. But their biological activities need studying further.
Objective To investigate the effect of small interfering RNA(siRNA) targeting hypoxia inducible factor1alpha; (HIF1alpha;) and vascular endothelial growth factor (VEGF) on expression of VEGF in human vascular endothelial cells. Methods HIF-1alpha; siRNA recombinant plasmid was constructed. Human vascular ndothelial cells were cultured in vitro and divided into normoxia group (20% O2) and hypoxia group (1% O2). Hypoxia group was then divided into control group, vector group, HIF-1alpha; group (HIF-1alpha; siRNA), VEGF group ( VEGF165 siRNA) and cotransfection group (HIF-1alpha; siRNA+VEGF165 siRNA). LipofectamineTM 2000 (LF2000) mediated vector plasmid was transfected to cells in each group except the control group. The expression of HIF-1alpha; siRNA and VEGF165 siRNA recombinant plasmid were identified by reverse transcriptasepolymerase chain reaction (RT-PCR). The expression of VEGF mRNA and protein were detected by RTPCR and immunocytochemical method. Results The expression of HIF-1alpha; siRNA and VEGF165 si RNA recombinant plasmid were detected 24 hours after transfected. The expression of VEGF mRNA and protein was faint in the normoxia group, but increased obviously in hypoxia group. The expression of VEGF mRNA and protein in the HIF1alpha;, VEGF and cotransfection groups were lower than which in the control group. Cotransfection group showed the highest inhibitory effect. Conclusion HIF-1alpha; and VEGF165 siRNA can effectively inhibit the expression of VEGF in human vascular endothelial cells.
