Objective To observe the inhibitory effects of gene transfer of canstatin on retinal neovascularization in mice. Methods Fifty-six 7-day-old C57BL/6J mice were randomly divided into control group,oxygen-induced retinopathy (OIR) group, empty vector group and treated group,14 mices in each group. Except for the control group,the mice in the other groups were exposed to (75plusmn;2)% oxygen for 5 days and then back to the normal air to establish the model of OIR. On postnatal 12 day, the treated group was received intravitreal injection of canstatin pCMV-HA, while the empty vector group was received the same volume of empty plasmid.The changes of retinal vessels were observed by Evans blue angiography on postnatal 17 day. With parafin section which stained by hematoxylin and eosin, then the number of endotheliocyte nuclei breaking throuhgh the internal limiting membrane（ILM） was observed and counted by optical microscope.Results Retinal blood vessels distributed regularly in treated group compared with OIR group and empty vector group.The differences of the number of endotheliocyte nuclei breaking throuhgh ILM in treated group was significant compared with the other two groups（F=39.006，Plt;0.001).Conclusion The canstatin pCMV-HA can effectively inhibit the retinalneovascularization in OIR.
OBJECTIVE To probe the possibility of direct transfer of exogenous gene into peripheral nerve and its following expression in vivo. METHODS The PCMV beta plasmid containing cytomegalovirus (CMV) promoter and Escherichia Coli (E. Coli), beta-Galactosidease (beta-Gal) structural gene (lacZ gene) was constructed and injected into the rabbit sciatic nerve. The control group was injected PBS solution. The injected nerves were sampled and tested by beta-Gal enzyme activity assay of the 5-bromo-4-chloro-3-indolyl-beta-D-galactoside and beta-Gal histochemical stain. RESULTS In the control group, no beta-Gal enzyme activity was detected in the different stages after operation, and beta-Gal histochemical stains showed positive. In the experimental group, enzyme activity could be detected from 2 days to 30 days after operation, and the histochemical stains showed negative. CONCLUSION The exogenous gene can be transferred into peripheral nerve and expressed with bioactivity, thus the gene therapy to accelerate the recovery of nerve is practical.
Objective To investigate the stable, high effective and low toxicity gene transfer vectors’ basics in research and clinical application.Methods Current status of hepatocytedirected gene transfer vectors were reviewed by history document and contemporary experimental advances analysis.Results Viral and nonviral vector systems could both transduce target genes to liver effectively with various transduction rates based on their corresponding biological characteristics.Conclusion Hepatocyte is the effective target for gene therapy of liverrelated genetic, neoplastic and infectious diseases, although the security needs to be further evaluated.
With the advancement of molecular biology technology and the development of genetics, the viral vector system has been continuously improved and optimized. The viral vector system has gradually become one of the best carriers in ophthalmic gene therapy. Adenovirus vector has the characteristics of transient expression and plays an important role in reducing corneal immune response. Lentiviral vector has the characteristics of stable and high efficiency and can be expressed slowly in the body for a long time.Adeno-associated virus vector has the characteristics of low immunogenicity, high efficiency and precision and can infect a variety of retinal cells. The combined use of adeno-associated virus vector and CRISPR-Cas9 provides new methods for precise treatment of ophthalmic genetic diseases. The advent of viral vectors has significantly increased the potential of gene therapy and has unparalleled advantages over traditional therapies. We have reason to believe that virus-based gene transduction technology will soon achieve clinical application in the near future, and a large number of difficult ophthalmic problems will be solved by then.
ObjectiveTo investigate the expression of miR-195 and the underlying molecular mechanisms of miR-195 regulating HMGB1 in diabetic retinopathy (DR). MethodsExtract 5 ml venous blood from DR patients, diabetes mellitus (DM) patients and normal subjects, then extract and perificate plasma total RNA. MicroRNA array and real time polymerase chain reaction (RT-PCR) was used to screen out miRNAs which were expressed with significant differences in the serum of patients with DR. Bioinformatics was employed to predict the miR-195 related to high mobility group box 1 (HMGB1) regulation. Next, miR-195 was down-regulated or up-regulated in umbilical vein endothelial cells through transfection of miR-195 inhibitor and miR-29b mimics respectively.Then we analyzed expression of HMGB1 mRNA and protein by RT-PCR and Western blot. ResultsMicroRNA array results showed the expression of miR-195 in DR group is decreased by 8.34 times and 11.47 times compared with DM group and the normal group. RT-PCR verification results conforms to the microRNA array results. Compared with the DM group (F=0.034, t=8.057) and the normal group (F=0.370, t=9.522), the expression of miR-195 in DR group were significantly reduced, the differences were statistically significant (P < 0.05). RT-PCR showed that the expression of HMGB1 mRNA was significantly decreased in up-regulation group, compared with blank (F=0.023, t=11.287) and negative control group (F=0.365, t=7.471), the difference was statistically significant (P < 0.05). The expression of HMGB1 mRNA was significantly increased in down-regulation group, compared with blank (F=0.053, t=10.871) and negative control group (F=0.492, t=6.883), the difference was statistically significant (P < 0.05). Western blot showed that the expression of HMGB1 protein was significantly decreased in up-regulation group, compared with blank (F=0.021, t=8.820) and negative control group (F=0.039, t=7.401), the difference was statistically significant (P < 0.05); and significantly increased in down-regulation group, compared with blank (F=0.186, t=10.092) and negative control group (F=0.017, t=12.923), the difference was statistically significant (P < 0.05). ConclusionMiR-195 can inhibit the expression of HMGB1, reduce the inflammation and angiogenesis, thereby delaying or inhibiting the occurrence and development of DR.
Objective To construct small hairpin RNA (shRNA) expression plasmid targeting rat opticin gene.Methods Four pairs of opticin oligonucleotides were synthesized and inserted into the plasmid vector, resulting into four plasmids: shRNA-1, shRNA-2, shRNA-3 and shRNA-4. Then the four constructed shRNA expression vectors and empty vector were transfected into rat ciliary non-pigment epithelium (NPE) cells by lipofectmaine 2000. Nontransfected NPE cells were set as control group.The expression of opticin mRNA and protein were measured by Reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot respectively.Results The opticin mRNA expression of the shRNA-1,shRNA-2,shRNA-3,shRNA-4 group were decreased compared with the control group (F=10.239，P＝0.000)；the inhibitory rate were 85.7%，62.87%，54.87% and 48.77% respectively.The opticin protein expression of the shRNA-1,shRNA-2,shRNA-3,shRNA-4 group were also decreased compared with the control group (F=17.870，P=0.000)；the inhibitory rate were 78.7%，34.6%，31.1% and 16.8% respectively.Conclusions The shRNA-1 expression plasmid has most potent inhibitory effect on opticin expression in rat ciliary NPE cells.
Objective To compare the transfection effects on soluble fms-like tyrosine kinase receptor-1 (sFlt-1) gene (2-4 transcellular region) mediated by carboxymethylated dextran coated nanoparticle and lipofectamineTM2000.Methods The plasmid pcDNA3.1-EGFP/sFlt-1(2-4) was constructed and assessed by enzyme cut, electrophoresis, and genetic sequencing. Three groups were divided: nanoparticle group, lipofectamine group, and non-transfected group. Twenty-four and 48 hours after the transfection, the distribution of cellular green fluorescence was oberved under the inverted phase contrast fluorescence microscope; the expression rate of green fluorescence was measured by flow cytometry; the expression of sFlt-1(2-4)mRNA and the protein was detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blot; the growth of the cells was observed by methyl thiazolyl tetrazolium (MTT) colorimetry and the relative growth rate (RGR) of the cells in each group was calculated; the cellular apoptosis in each group was detected by Hoechst staining.Results The sequence of sFlt-1(2-4) gene was equal to 915 base pair (bp).The transfection rate was 45% in nanoparticle group and 21% in lipofectamine group; the difference between the two groups was significant (t=2.541，Plt;0.05). Forty-eight hours after the transfection, the expression of sFlt-1（2-4）mRNA and protein was obviously higher in nanoparticle group than that in lipofectamine group (t=2.454，2.398；Plt;0.05) . Twenty-four and 48 hours after the transfection,the difference of RGR of the cells between nanoparticle and non-transfected group was not significant（t=1.436，Pgt;0.05）; the RGR in lipofectamine group differed much from that in non-transfected and nanoparticle group (t=2.412，2.545; Plt;0.05) ; the difference of cellular apoptosis was not significant between nanoparticle and nontransfected group (t=1.436，Pgt;0.05), but significant between nanoparticle and lipofectamine group (t=2.236，Plt;0.05). Conclusion The transfection rate of sFlt-1(2-4) mediated by carboxymethylated dextran coated nanoparticle was higher than that mediated by lipofectamineTM2000.
Objective To investigate the effect of B7-1 and IL-12 gene expression on the immunogenicity of hepatocellular carcinoma (HCC) HepG2 cells. Methods Plasmids encoding B7-1 and IL-12 molecules were retrovirally introduced into human HCC cells,empty vector as control. PBLs were cocultured with HepG2/B7-1,HepG2/IL-12 and HepG2/neo cells. Three days later,PBLs were submitted to specific cytotoxicity test and nonspecific cytotoxicity test against K562 cells by MTT assay.Results HLA-Ⅰ molecules on PBLs were detected by FACS.HLA-Ⅰ molecules expressing on PBL cocultured with HepG2/B7-1,HepG2/IL-12 cells were enhanced by 16.95% and 14.71% than those of HepG2/neo group, respectively(Ｐ＜0.05). Specific cytotoxicity against HepG2/B7-1 cells was 12.5% higher than that of against HepG2/neo cell,while no increase in that of against HepG2/IL-12 cells. Cytotoxicities against K562 cells in HepG2/B7-1,HepG2/IL-12 groups were 19.38% and 14.78% higher than those of HepG2/neo group, but no significant difference between the first two groups.Conclusion B7-1 and IL-12 gene transfer could remarkably promote immunogenicity of hepatocellular carcinoma cells and induce b specific and nonspecific immunity against hepatocellular carcinoma in vitro.
Objective To observe the inhibition of LipofectamineTM2000 (LF2000)mediated pSUPER recombinant plasmid expressing small interference RNA targeting hypoxia-induced factor (HIF)-1alpha;(pSUPERsiHIF-1alpha;) on retinal neovascularization in mice. Methods pSUPERsiHIF-1alpha; recombinant plasmid was created. Forty-eight (seven-day-old) C57BL/6J mice were randomly divided into a normal group, the control group, empty vector group and gene therapy group with 12 mice in each group. Mice in the normal group were kept in normal room air, while the other three groups retinal neovascularization was induced by hypoxia. The mice in control group were not treated. The mice in the vector group received intravitreous injection of pSUPER and LF2000 (1 mu;l), and the gene therapy group received pSUPERsiHIF-1alpha; and LF2000 (1 mu;l)one day before being returned to normal room air．Fluorescent angiography was used to assess the vascular pattern. The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections．HIF-lalpha;and vascular endothelial growth factor (VEGF) levels in retinas were measured by immune histochemical staining method and reverse transeriptase-polymerase chain reaction (RT-PCR). Results Fluorescent angiography showed radial branching pattern vessels in the normal group and distorted large vessels, obstructed capillaries, many neovascular tuffs, fluorescence leakage in the peripheral retina in the control group and vector group. The gene therapy group demonstrated a significant reduction in neovascular tufts and fluorescence leakage compared with the control group and the vector group. The number of vascular cell nuclei extending breaking through the internal limiting membrane(ILM) of control group and vector group increased significantly compared with normal group (F=5850.016,P＜0.05), while obviously decreasing in the gene therapy group compared with control group (F=3012.469,P＜0.05). Immunohistochemical staining showed the expression of HIF-1alpha; protein in nucleus and VEGF protein in cytoplasm. The expression of HIF-1alpha; protein in retina was negative, while VEGF protein was weakly positive in normal group. The expression of HIF-1alpha; and VEGF protein were both positive in control group and vector group, while weakly positive in gene therapy group. The Results of RT-PCR showed that the expression of HIF-1alpha; mRNA in retina was increased significantly in control group and vector group as compared with normal group (F=3102.326,P＜0.05), while decreasing significantly in gene therapy group as compared with control group (F=3336.425,P＜0.05). Conclusion Retinal neovascularization in the mice is significantly inhibited by intravitreal injection of LF2000-mediated recombinant plasmid pSUPERsiHIF-1alpha;.
ObjectiveTo observe the effect of adenovirus-mediated Tum5 (rAd-Tum5) inhibiting retinal neovascularization (RNV) of oxygen-induced retinopathy (OIR) mouse model. MethodsThe OIR model was induced in 96 C57BL/6J mice aged of 7 days according to the literature. These mice were divided randomly into control group, OIR group, OIR rAd-green fluorescent grotein (GFP) group and OIR rAd-Tum5 group, each group had 24 mice. The rAd-GFP and rAd-Tum5 were injected into the vitreous cavity of mice aged of 12 days in OIR rAd-GFP group and OIR rAd-Tum5 group, respectively. Meanwhile, OIR group and the control group received the injection of physiological saline solution of same volume. The relatively non-perfusion area was evaluated by fluorescence angiography, and the number of pre-retinal nucleus breaking through internal limiting membranes was observed by hematoxylin-eosin staining. The expression of vascular endothelial growth factor (VEGF) was estimated by immunofluorescent (IF) and Western blot. ResultsThe retinal avascular areas of all groups were significantly different (F=61.224, P<0.01). The retinal avascular area of the rAd-Tum5 group was decreased significantly comparing with that in the OIR group and rAd-GFP group (P<0.01). However, there are no significant differences between the OIR group and rAd-GFP group (P=0.827). The number of pre-retinal nucleus breaking through ILM of all groups was significantly different (F=635.738, P<0.01), but no significantly difference was observed in OIR group and rAd-GFP group (P=0.261). Significant differences could also been seen between OIR rAd-Tum5 group and OIR group as well as OIR rAd-Tum5 group and OIR rAd-GFP group (P<0.01). The results of IF and Western blot indicated that expression of VEGF in the OIR group and rAd-GFP group was obviously up-regulated, compared with that in the control group. But the expression was declined in the rAd-Tum5 group compared with that in the OIR group and rAd-GFP group. ConclusionTum-5 peptide can efficiently prevent RNV probably by down-regulating expression of VEGF.