ObjectiveTo detect the effect of adeno-associated-virus induced Kringles5 gene on retinal neovascularization in rats with retinopathy of prematurity (ROP), and to explore the new ways of treatment for ROP.MethodspSNAV-Kringle5-gfp carrier was constructed by subclone and adeno-associated-virus was packed to form rAAV-Kringle5-gfp. ROP model was set up under circumstances of high oxygen in 21 SD rats which were divided into experimental (21 eyes) and control group (21 eyes). Eighteen eyes from each group was used to making the histologic section of retina, and the other 3 eyes in each group was detected by polymerase chain reaction (PCR) and Western blotting. There were 5 rats in the normal control group. AAV-Kringle5-gfp with the dosage of 10 μl and titer of 2.5×1012vg/ml was injected into the eyes in experimental group, while rAAVlacZ with the same dosage and titer of 2.5×1011vg/ml was injected in to the eyes in control group. The expression of target gene in ocular tissues was observed under the fluoroscope. Twelve weeks later, the rats were executed, and the staining of Ⅷ factor related antigens in retinal vascular endothelial cells was performed and number of nucleolus of vascular endothelial cells were counted. ResultsThe plasmid of pSNAV-Kringle5-gfp was correct according to the sequence measurement; the expression of rAAV-Kringle5-gfp was found in vitreous cavity and on retina; the expression of target gene was found on the level of mRNA and protein; the number of nucleolus of vascular endothelial cells on the surface of retina was (19.954 2±3.825 7) in experimental group and (7.335 2±2.731 3) in the control group, which had significant difference between the two groups (P＜0.01）.ConclusionsAdeno-associated-virus induced Kringles5 gene can inhibit the occurrence of retinal neovascularization in patients with ROP.(Chin J Ocul Fundus Dis, 2005,21:288-291)
Clustered regularly interspersed short palindromic repeats/Cas system is a powerful genome-editing tool for efficient and precise genome engineering both in vitro and in vivo, with the advantages of easy, convenient and low cost. This technology makes it possible to simultaneously mutate multiple genes in a single fertilized egg, thus to study the gene expression, genetic interaction and gene function. Even though this method is still in its immature stage and its stability is inconclusive, making precision models of ocular diseases through genome editing may provide a positive effect to explore gene targeted therapy in genetic eye disease.
Duchenne muscular dystrophy is an X-linked inherited progressive degenerative muscle disease caused by mutations in the dystrophin gene, and is one of the most common progressive muscular dystrophies. We will review the selection of genetic diagnosis methods for Duchenne muscular dystrophy, the selection of experimental animal models, and treatment for the primary cause (including gene replacement therapy, exon skipping therapy, genome editing, stop codon read-through therapy, and stem cell therapy), the treatment of secondary pathological reactions and methods of assessing disease progression. The purpose is to enrich clinicians’ knowledge of the disease and provide a reference and help for the clinical diagnosis and treatment of Duchenne muscular dystrophy.
Objective To investigate the effect of myoblast transplantation on duchenne muscular dystrophy (DMD) and to explore the method and feasibil ity of applying gene therapy to DMD. Methods Myoblast of C57/BL10 mice were cultured using multiple-step enzyme digestion method and differential velocity adherent technique. The morphology of the cells was observed with inverted phase contrast microscope. The cells at passage 4 were labeled with 5-BrdU. Twenty-four DMDmodel mice (mdx mice: aged 4-6 weeks, male, 13.8-24.6 g) were randomly divided into two groups (n=12 per group): group A, 1 × 106/mL labeled myoblast were injected via ven caudal is twice at an interval of 2 weeks; group B: 1 mL DMEM/F12 was injected in the same manner serving as a control group. The mice were killed 4 weeks after operation and the motor abil ity of the mice was detected by one-time exhaustive swimming before their death. HE staining and immunohistochemistry staining observation for 5-BrdU, desmin, and dystrophin (Dys) were preformed, and the imaging analysis was conducted. Results The primary myoblast could be sub-cultured 5-7 days after culture, providing stable passage and sufficient cells. The time of onetime exhaustive swimming was (60.72 ± 5.76) minutes in group A and (47.77 ± 5.40) minutes in group B, there was significant significance between two groups (P lt; 0.01). At 4 weeks after injection, HE staining showed that in group A, there were round and transparent-stained myocytes and the percentage of centrally nucleated fibers (CNF) was 67%; while in group B, there were uneven muscle fiber with such pathological changes as hypertrophia, atrophia, degeneration, and necrosis, and the percentage of CNF was above 80%. Immunohistochemistry staining revealed that the expression of 5-BrdU, desmin, and Dys was positive in group A; while in group B, those expressions were l ittle or negative. Image analysis result displayed that integral absorbency (IA) value of desmin was 489.70 ± 451.83 in group A and 71.15 ± 61.14 in group B (P lt; 0.05) and the ratio of positive area to thetotal vision area was 0.314 3 ± 0.197 3 in group A and 0.102 8 ± 0.062 8 in group B (P lt; 0.05); the Dys IA value was 5 424.64 ± 2 658.01 in group A and 902.12 ± 593.51 in group B (P gt; 0.05) and the ratio of positive area to the total vision area was 0.323 7 ± 0.117 7 in group A and 0.035 2 ± 0.032 9 in group B (P lt; 0.05). Conclusion Myoblast transplantation has certain therapeutic effect on DMD of mice.
OBJECTIVE This paper aims to explore the new method of continuous delivery of epidermal growth factor to wounds by transfected fibroblasts to promote wound repair. METHODS It was constructed a novel chimeric expression plasmid in which the biologically active portion of the human epidermal growth factor (EGF) gene was fused in-frame to the human granulocyte colony-stimulating factor signal sequence. RESULTS Clonally selected human fibroblasts transfected with this construct could secrete biologically active EGF. After the transplantation of irradiated gene-transfected fibroblasts suspended in fibrin glue to murine full-thickness wounds, EGF could be demonstrated for at least seven days in the wounds, slowly decreasing from initially 470 ng/L to 140 ng/L in 7 days. No EGF was found in the wound at 14 days. CONCLUSION A single application of irradiated EGF gene transfected fibroblasts to wounds can continuously deliver the transgene in vivo and can be used to administer drugs to the wound bed during the crucial first seven days of wound-healing.
Objective To observe the influence of rAAV-mediated antisense vascular endothelial growth factor (rAAV-aVEGF165) on the expression of retinal VEGF in diabetic rats. Methods 40 Sprague-Dawley rats induced diabetic rat model by intraperitoneal injection with streptozotocin (STZ). 32 rats were involved in study besides death and blood sugar recovery in experimental process, 16 spragud-Dawleg (SD) rats were received intravitreal injection with rAAV-aVEGF165 (1010 pfu) as experimental group, another group of Sprague-Dawleg (SD) rats were injected with phosphate buffered saline (PBS) as control group. One and five month after model establishment, the expression of retinal VEGF was evaluate by immunhistochemistry and Western blot; the retinal vasular was examined by transmission electron microscopy. Results On 1 month,the expression of retinal VEGF was lowest in each group. On 5 month, the expression of retinal VEGF was decreased in experimental group which compared to control, the difference are statistically significant （t=23.87,Plt;0.01）. The transmission electron microscopy results showed that retina has no obvious chages in experimental group, however,contral group showed fragmental thickening and splitting of basement membrane, swelling and deformation of endothelia cells,fingerlike prcess into the capillary cavity,and uneven distibution of heterochromatin in pericytes. Conclusion rAAV-aVEGF165 can reduce the expression of retinal VEGF thereby preventing occurrence and development of diabetic retinopathy. rAAV is an effective vectors of eye antisense gene. （Chin J Ocul Fundus Dis，2008，24：255-258）
ObjectiveTo explore the effect of five copies hypoxia-responsive element (5HRE) and carcinoembryonic antigen promoter (CEAp) element, and to explore the inhibition effect of lentiviral vectors targeted Ras association domain family 1 isoform A (RASSF1A) gene on SGC7901 human gastric cancer cells. Methods①Expressions of carcinoembryonic antigen (CEA) mRNA and its protein, and RASSF1A protein in SGC7901, MKN28, and MCF-10A cells were detect by real time-PCR (qRT-PCR), immunocytochemistry, and Western blot, to confirm the experimental and negative control cells.②The recombinant vectors of pGL4.20-5HRE-CEAp-Luc were constructed through molecular cloning technique to transfected SGC7901, MKN28, and MCF-10A cells. Each kind of cell was divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). Comparison of the fold of activation was performed.③SGC7901 cells were infected by lentiviral vectors of pLV-5HRE-CEAp-RASSF1A (infection group) and negative virus (negative control group), SGC7901 cells without any treatment as blank control group. Then SGC7901 cells of 3 groups were divided into 2 groups:one of them didn't add CoCl2 (normoxia group), and another group added CoCl2 (hypoxia group). The expression of RASSF1A protein was tested by Western blot, and the growth inhibition rate was confirmed by cell counting kit-8 (CCK-8) assay. Comparisons of expression of RASSF1A protein and growth inhibition rate of each group were performed. Results①Results of qRT-PCR, immunocytochemistry and Western blot showed that, SGC7901 cells showed higher expression of CEA mRNA and positive expression of RASSF1A protein than corresponding index of MKN28 cells and MCF-10A cells (P < 0.05), which were assigned as experimental cells; but MKN28 cells showed lower expression of CEA mRNA and negative expression of RASSF1A protein, which were assigned as negative control cells.②In SGC7901 and MKN28 cells transfected recombinant vectors of pGL4.20-5HRECEAp-Luc, compared with normoxia group in the same kind of cell group, the folds of activation in hypoxia group were higher (P < 0.01), but there was no significant difference between the normoxia group and hypoxia group in MCF-10A cells (P > 0.05). In the condition of with or without CoCl2, compared with SGC7901 cells in the same condition, the folds of activation in MCF-10A and MKN28 cells were both lower (P < 0.05); compared with MKN28 cells, the fold of activation in MCF-10A cells was lower (P < 0.05).③Western blot results showed that, in the condition with and without CoCl2, expressions of RASSF1A protein decreased in SGC7901 cells of blank control group and negative control group; weak expressions of RASSF1A protein was observed in SGC7901 cells of infection group when in condition of without CoCl2, but increased when adding CoCl2. But RASSF1A protein didn't expressed in MKN28 cells of blank control group, negative control group, and infection group, whether adding CoCl2 or not. CCK-8 assay result showed that, in SGC7901 cells, the growth inhibition rate of infection group which added CoCl2 was higher than those of other 5 groups (P < 0.05); in MKN28 cells, the growth inhibition rates of infection group and negative group were all higher than those of blank control group, whether adding CoCl2 or not (P < 0.05), but there was no significant difference among the infection group and negative group, whether adding CoCl2 or not (P > 0.05). ConclusionsA new hypoxia inducible and cea-positive tumor-targeting transcriptional regulatory element of 5HRE-CEAp is established successfully, and lentivirus vector of pLV-5HRE-CEAp-RASSF1A can significant inhibit the growth of SGC7901 cells under hypoxia condition.
Objective To construct the recombinant adenovirus bearing human transforming growth factor β1(TGF-β1) and bone morphogenetic protein 7 (BMP-7) genes, and investigate its co-expression in the marrow stromalstemcells (MSCs) and bioactivity effect. Methods Using the replication defective adenovirus AdEasy as a carrier, MSCs were infected by the high-titer-level recombinant adenovirus taking TGF-β1 and BMP-7 genes. Immunocytochemistry, in situ hybridization，reverse transcription-polymerase chain reaction (RT-PCR), and hexuronic acid level test were used to detect the coexpression of the exogenous genes and to analyze their effect transfection on directive differentiation of MSCs. Results The immunocytochemistry staining showed that the brown coarse grains were situated in the cytoplasm of the most MSCs 72 h after infection. Procollagen ⅡmRNA in the cells was detected by the in situ hybridization, and the content of hexuronic acid in the culture mediumwas significantly increased 10 days after infection compared with the level before infecton (Plt;0.01). Conclusion The recombinant adenovirus bearing human TGF-β1 and BMP-7 genes can be constructed, and the exogenous gene can be coexpressed in MSCs, which may offer a novel approach to thelocal combination gene therapy for repairing joint cartilage defects.
OBJECTIVE: To study the effect of overexpression of truncated type II TGF-beta receptor on transforming growth factor-beta 1(TGF-beta 1) autoproduction in normal dermal fibroblasts. METHODS: In vitro cultured dermal fibroblasts were treated with recombinant human TGF-beta 1(rhTGF-beta 1) (5 ng/ml) or recombinant adenovirus containing truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-beta 1 were observed with Northern blotting. RESULTS: rhTGF-beta 1 up-regulated the gene expression of TGF-beta 1 and type I procollagen. Overexpression of truncated receptor II down-regulated the gene expression of TGF-beta 1. CONCLUSION: Overexpression of the truncated TGF-beta receptor II decreases TGF-beta 1 autoproduction via blocking TGF-beta receptor signal. The results may provided a new strategy for scar gene therapy.
Fundus disease is a kind of common ophthalmic disease with high blindness rate and great harm. Although great breakthroughs have been made in medical treatment, laser photocoagulation, radiotherapy and gene therapy of fundus disease, with the further understanding of the essence of fundus disease, there are higher requirements for the treatment of fundus disease. To strengthen scientific research on the etiology, pathological mechanism and clinical treatment of fundus diseases, to control the quality of research, to develop reasonable treatment plans and explore new treatment methods under the guidance of evidence-based medicine theory, to further improve the level of medical treatment and benefit patients with fundus diseases will still be a formidable challenge in the future.