Objective To observe the effects of immunologic cytokines or anti-angiogenesis gene transfer mediated by electroporation for choroidal melanoma cells.Methods The human embryo kidney cells and malignant choroidal melanoma cells were transfected with plasmids pNGVL-mIL2, pNGVL-mIL12, pCI-sFLK-1, pCR3.1-antiVEGF121,pCI-ExTek. Then the expression of mIL2, mIL12, sFLK-1, VEGF and ExTek were detected by enzymelinked immunosorbentassay (ELISA) and Western blot. Nude mice models of malignant choroidal melanoma were established and they were divided into four groups randomly. Each group was treated with 30 mu;l of 0.9% NaCl, 30 mu;g pNGVL, 30 mu;g antiVEGF121+sFLK-1+ExTek and 30 mu;g mIL2+mIL12 respectively by electroporation. Seven，14, 21, 28, 35 and 42 days after treatment, the tumor volumes were measured to calculate the tumor inhibition rate. Results ELISA and Western blot showed that mIL2，mIL12，sFLK-1 and ExTek were expressed after electroporation，VEGF expression was decreased remarkably. After treatment，the tumors of mIL2+mIL12 group were greatly inhibited with a tumor inhibition rate of 97.33%，while the tumors of antiVEGF121+sFLK-1+ExTek and pNGVL group were partially inhibited with tumor inhibition rates of 53.33% and 36.33% respectively.Conclusions Immunologic cytokines transfer mediated by electroporation can inhibit the growth of melanoma，but anti-angiogenesis only have a mild effects.
Objective To investigate if lactic acid can promote the expression of vascular endothelial growth factor (VEGF) in the rat retinal explants.Methods The retinas of two-week neonatal SD rats were placed onto the culture plate inserts and incubated with Dulbeccoprime;s modified Eagleprime;s medium （DMEM） plus 2% fetal bovine serum (FBS) containing 10,20,30 mmol/L of lactic acid, respectively. Each group had 24 retinas. At 24 hours after incubation, the retinas were sectioned for light microscopy and the expression of VEGF was measured by real time PCR and Western blot. Results The cultured retinas maintained intact construction, and no cytolysis and apoptosis were observed under light microscope. RT-PCR showed the levels of VEGF mRNA were 0.74plusmn;0.06 for 10 mmol/L lactic acid group, 0.99plusmn;0.12 for 20 mmol/L group, and 1.45plusmn;0.17 for 30 mmol/L group respectively. VEGF expression was 0.34plusmn;0.15 for 10 mmol/L, 0.54plusmn;0.16 for 20 mmol/L, and 0.93plusmn;0.23 for 30 mmol/L group respectively by Western blot. Both PCR and Western blot showed 30 mmol/L of lactic acid significantly increased the levels of VEGF mRNA and VEGF expression. Conclusion The induction of retinal VEGF by lactic acid is concentration-dependent.
Objective To observe the effects of dual targets intervention on the expression of vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) in diabetic rat retina. Methods Forty-eight Sprague -Dawley rats were randomly divided into control group (CON1 group) and diabetes mellitus group (DM group). The rats of DM group were induced with streptozotocin injection creating a diabetic model. Retinas were obtained at eight, 10, 12 weeks after DM induction from both groups. CTGF and VEGF mRNA levels were examined by realtime reverse transcriptionpolymerase chain reaction (RT-PCR). Based on the results of above experiments, 60 rats with same conditions were selected. Fifty rats were induced with streptozotocin injection creating a diabetic model, and 10 rats comprised the control group (CON2 group). Then the 50 diabetic rats were randomly divided into ranibizumab and CTGF shRNA dual targets intervention group, ranibizumab singletarget intervention group, CTGF shRNA singletarget intervention group and nonintervention group. Retinas were obtained at one week after intervention from all the groups. CTGF and VEGF mRNA levels were examined by RT-PCR. Results The levels of CTGF mRNA were significantly higher in DM group than that in CON1 group at the 8th weeks after DM induction, and this upregulation was maintained through the 12th week (t=-2.49, -2.67, -2.42;P＜0.05). There was no difference on VEGF mRNA levels between DM group and CON1 group at the 8th weeks after DM induction(t=-0.443,P=0.669). VEGF mRNA levels of DM group started to be significantly elevated over those in the CON1 group at the 10th week, and remained to be higher at the 12th week (t=-2.35, -2.57;P＜0.05). The VEGF mRNA of ranibizumab single-target intervention group was significantly lower than that in non-intervention group (t=-3.44,P=0.014), which was similar to CON2 group (t=-1.37,P＞0.05); however, the CTGF mRNA level was significantly increased as compared to the nonintervention group (t=2.48,P＜0.05). In the CTGF shRNA single-target intervention group, the levels of CTGF and VEGF mRNA were decreased as compared to the non-intervention group (t=0.23, -2.92;P＜0.05). In the ranibizumab and CTGF shRNA dual targets intervention group, the levels of CTGF and VEGF mRNA were decreased as compared to the non-intervention group (t=-6.09, -5.11;P＜0.001), which was similar to CON2 group (t=-1.16, 1.139; P＞0.05). Conclusions Both CTGF and VEGF gene expression are up-regulated in early diabetic rat retina, and the level of CTGF increased earlier than VEGF. Ranibizumab combined with CTGF shRNA could simultaneously reduce the level of CTGF and VEGF mRNA in diabetic rat retina.
ObjectiveTo observe the expression of Rap1, guanosine triphosphate-Rap1 (GTP-Rap1), vascular endothelial growth factor (VEGF) and β-catenin in experimental choroidal neovascularization (CNV).MethodsForty-two brown Norwegian rats were randomly divided into a blank control group (7 rats) and a model group (35 rats). Both eyes were enrolled. The CNV model was established by holmium ion laser photocoagulation in the model group. At 3, 7, 14, 21, and 28 days after photocoagulation, fluorescein fundus angiography (FFA) and choroidal vascular smear were performed to observe the degree of fluorescein leakage and CNV area in rats; Western blot and real-time quantitative polymerase chain reaction (RT-PCR) were used to detect the expression of Rap1, GTP-Rap1, VEGF, β-catenin and mRNA in CNV.ResultsThe results of FFA examination showed that a large disc-shaped fluorescein leaked in the photo-condensation spot 14 days after photocoagulation. Laser confocal microscopy showed that compared with 7 days after photocoagulation, CNV area increased at 14, 21, 28 days after photocoagulation, and the difference were statistically significant (t=3.725, 5.532, 3.605;P＜0.05). Western blot showed that there was no significant difference in the relative expression of Rap1 protein in CNV at different time points after photocoagulation between the two groups (P=0.156). Compared with the blank control group, the relative expression of GTP-Rap1 protein was significantly decreased, the relative expression of VEGF and β-catenin protein were significantly increased in the model group (P=0.000). The results of RT-PCR showed that there was no significant difference in the relative expression of Rap1 mRNA at different time points after photocoagulation between the two groups (P=0.645), but there were significant difference in the relative expression of β-catenin mRNA (P=0.000). At 7, 14, 21 and 28 days after photocoagulation, there were significant difference in the relative expression of GTP-Rap1 and VEGF mRNA between the two groups (P=0.000).ConclusionsThe expression of GTP-Rap1 in experimental CNV is significantly lower than that in normal rats.
Anti-vascular dndothelial growth factor (VEGF) drugs have open up a new treatment channel for ocular neovascular diseases. A lots of clinical data has proved that anti-VEGF drugs are effective and safe. But we should also notice that long-term and excessive usage of anti-VEGF drugs brings some new problems and complications, and even affect the normal ocular physiological process of the angiogenesis and retinal blood flow. So, it is necessary to pay attention to the problems and potential risks of excessive usage of anti-VEGF therapies for ocular neovascular disease.
The introduction of anti-vascular endothelial growth factor (VEGF) therapy represents a landmark in the management of wet age-related macular degeneration (AMD). However, as a new therapy, several problems such as durability of the therapeutic effects, medication side effects, and medication selection have emerged. We should make appoint of improving the therapeutic effect and safety by realizing the limitation of the therapy, monitoring the clinical potential adverse reactions of anti-VEGF agents, and recommending individualized treatment.
Objective To observe the application and effectiveness of bevacizumab intravitreal injection as adjunctive treatment for laser coagulation to treat retinopathy of prematurity (ROP). MethodsFrom March 2008 to October 2010, 17 infants (31 eyes) with ROP received bevacizumab intravitreal injection and were analyzed. Ten infants were male (18 eyes) and 7 were female (13 eyes).Their gestational age was from 24.7 to 31.0 weeks, with a mean of (28.2±1.9) weeks. Their birth weight was from 750 to 1600 grams, with a mean of (1150±264) grams. The indications for treatment included poor papillary dilation and refractive media opacity precluding complete laser coagulation and that ROP could not be controlled after complete laser coagulation treatment. The duration of followup was 1.4 to 40.8 months, with a mean of (20.8±13.2) months. It was noted whether the diseases were completely controlled or not, unfavourable structural outcome occurred or not and if there were complications regarding treatment. Results During the follow-up of all 31 eyes, ROP of 27 eyes (87.0%) was controlled by bevacizumab intravitreal injection as adjunctive treatment for laser coagulation. Increasing neovascularization and traction retinal detachment occurred in 2 eyes (6.5%). These 2 eyes underwent vitreoretinal surgery. The posterior retinal structure returned to normal in 1 eye and posterior vitreoretinal traction occurred in 1 eye. After bevacizumab intravitreal injection ROP continued progressing and traction retina detachment occurred in 2 eyes. The overall health of this infant remained good during and after operation. No systemic adverse drug reactions were found. No endophthalmitis occurred. No ocular complications such as corneal burn, cataract, and anterior segmental ischemia were found. Conclusions During the follow-up，the effectiveness of bevacizumab intravitreal injection as adjunctive treatment for laser coagulation to treat ROP was positive. No complications regarding the treatment were found.
ObjectiveTo investigate the role of sonic hedgehog (Shh) signal transduction pathway in the expression of vascular endothelial growth factor (VEGF) under hypoxia in cultured human retinal pigment epithelial (hRPE) cells. MethodsARPE-19 were cultured and divided into normal ARPE-19 (Cont) and hypoxia group (100 μmol/L CoCl2 Cobalt Chloride +ARPE-19); hypoxia group was further divided into CoCl2 group, cyclopamine group (CYA) and dimethyl sulfoxide (DMSO) group. 20μmol/L cyclopamine was added to the CYA group 1 hour before hypoxia, 1‰DMSO was added into DMSO group at the same time. The hRPE cells were cultured under hypoxia for 4, 8, 12, 24 hours. The expression of Shh and VEGF were determined by Real-time fluorescent quantitate PCR (RT-PCR). The amount of VEGF in the hRPE-conditioned supernatant was measured using enzyme linked immunosorbent assay (ELISA) at 4, 8, 12, 24 hours, respectively. ResultsRT-PCR tests showed that the level of Shh and VEGF of hRPE was time dependently increased (Shh: F=45.260, P=0.001; VEGF: F=264.938, P=0.001). The level of Shh and VEGF of hRPE in the group treated with cyclopamine was decreased (P < 0.01). ELISA tests showed that the amount of VEGF in hRPE supernatant was significantly increased in time-dependent manner (F=3 156.676, P=0.001), and it was down-regulated by cyclopamine under hypoxia (P < 0.01). ConclusionShh signal transduction pathway could play a role in the VEGF expression induced by hypoxia in hRPE cells.
Objective To observe the expression of the pigment epithelium derived growth factor (PEDF) in retina and the effects of PEDF for vascular endothelial growth factor (VEGF) and retinal microvascular after recombinant adeno-associated virus mediated pigment epithelium derived factor（rAAV-mediated-PEDF）transferred retina of diabetic rats. Methods Male Wister rats were induced diabetes with intraperitoneal injection of streptozocin, then divided into 1 month group (DM1), 3month group(DM3) and 6 month group randomly. In diabetic rats, right eyes were injected rAAV2CMVhPEDF into vitreum as treat group,left eyes were injected into rAAV2-CMV-GFP (1times;1011 v.g/ml) as self-control group. In normal rats, right eyes were punctured but not injected (CONf), left eyes let it be without any disposal. The levels of VEGFmRNA and hPEDFmRNA in retina were evaluated using RT-PCR in different period. The protein levels of VEGF, PEDF within the retina were determined using western blot. The change of retinal capillary were observed through retinal vascular flattening. Result The expression of hPEDFmRNA in retina was enhanced persistence after rAAV2-CMV-hPEDF injected, achieved climax until 6 months. The levels of PEDF were also incerased consecutive, the differences were statistically significant in treatment group compared with own control group （Plt;0.01）. Levels of mRNA and protein of VEGF at different time-points among therapy group were not statistically significant, all obviously higher than normal （Plt;0.05），but all lower obviously than respectively own control group at the same timepoint （Plt;0.01）. The morphology of retinal capillary was not different significant with normal rats in 1 month diabetic rats. Morphology changes of therapy groups were less than those of respective own control group in DM3 and DM6. Conclusion Intravitreous injection rAAV2-CMV-hPEDF can increase expression of mRNA and protein of PEDF，alleviate lesion of retinal microvascular in early period of diabetic rats and supress expression of VEGF in retina of diabetic rats.The regulation occur on mRNA level. （Chin J Ocul Fundus Dis，2008，24：259-264）
Objective To study the relationship between the expression of sonic hedgehog (Shh) and vascular endothelial growth factor (VEGF) in hypoxic human retinal pigment epithelial (hRPE) cells. Methods Cultured hRPE-19 cells (3rd - 6th generations) were used in this experiment. hRPE-19 cells were divided into three groups including the control group, the hypoxia experimental group (100 μmol/L CoCl2) and the inhibition group (pretreatment with 20 μmol/L cyclopamine 1 hour before hypoxia). After culturing for 4, 8, 12 and 24 hours, the mRNA level of Shh and VEGF genes in these cells were measured by fluorescence quantitative polymerase chain reaction, and the protein level of Shh and VEGF in the supernatants were measure by enzyme-linked immunosorbent assay. The relationship between the expression of Shh and VEGF was analyzed by Pearson correlation analysis. Results The control group expressed low levels of Shh and VEGF mRNA/protein. The expression of Shh and VEGF mRNA/protein in the hypoxia experimental group was significantly higher than that in the control group (F=178.364, 183.732, 77.456, 91.572; P＜0.01). The expression of Shh and VEGF mRNA in the inhibition group was significantly lower than that in the hypoxia experimental group (F=68.745, 121.834; P＜0.01). In the hypoxia experimental group, the expression of VEGF protein was positively correlated with the expression of Shh protein (r=0.942, P＜0.05); and the expression of VEGF and Shh mRNA was positively correlated (r=0.970, P＜0.01). However, there was no significant correlation in the expression of VEGF and Shh mRNA in the inhibition group (r=0.915, P＞0.05). Conclusion There is a positive correlation between the expression of Shh and VEGF in hypoxic hRPE cells.