ObjectiveTo observe the expression of vascular endothelial growth factor (VEGF) and aquaporin 4 (AQP4) in the inner limiting membrane (ILM) of diabetic retinopathy (DR) with macular edema, and analyze the correlation between VEGF and AQP4 expression. Methods A cross-sectional study. From September 2019 to September 2020, 38 eyes of 38 patients with DR and idiopathic macular hole (iMH) who underwent vitrectomy (PPV) combined with ILM stripping at the Hangzhou campus of The Affiliated Eye Hospital of Wenzhou Medical University at Hangzhou were included in the study. Among them, there were 25 males and 13 females who aged 37-76 years old, average age was 59±10 years old; All eye included 15 right eyes and 23 left eyes. iMH and DR included 9 eyes in 9 cases and 29 eyes in 29 cases, respectively, and they were divided into iMH group and DR group. The DR group was divided into DME group and no DME group according to whether it was accompanied by diabetic macular edema (DME), with 14 eyes and 15 eyes respectively. After the stripped ILM tissue was fixed, immunofluorescence analysis was performed to obtain a picture of the fluorescence mode of AQP4 and VEGF, and the fluorescence intensity value of VEGF and AQP4 was measured by Image J software. The differences of VEGF and AQP4 immunofluorescence values in the specimens between groups were compared by one-way analysis of variance. The correlation between the fluorescence intensity of AQP4 and the fluorescence intensity of VEGF was analyzed by Pearson correlation analysis. Results The average fluorescence intensity valuesof VEGF and AQP4 in ILM specimens of DME group, no DME group and iMH group were 38.96±7.53, 28.25±3.12, 30.07±4.84 and 49.07±8.73, 37.96±6.45, 38.08±5.04, respectively. The average fluorescence intensity of VEGF and AQP4 in the ILM specimens of the DME group was significantly higher than that of the no DME group and iMH group, and the difference was statistically significant (F=13.977, 9.454; P＜0.05). The average fluorescence intensity values of VEGF and AQP4 on IML specimens in the DR group were 33.80±7.91, 43.76±9.44, respectively. The results of Pearson correlation analysis showed that the fluorescence intensity of VEGF and AQP4 in the ILM specimens of the DR group was significantly positively correlated (r=0.597, P=0.003). ConclusionsThe expressions of VEGF and AQP4 in ILM of eyes with DR and DME are significantly increased compared with those without DME. The expression of VEGF and AQP4 in ILM of eyes with DR is positively correlated.
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.
ObjectiveTo investigate the effects of transforming growth factor-β (TGF-β) in choroidal neovascularization (CNV) induced by laser in mice. Methods Eighty male C57BL/6J mice at the age of 6-8 weeks old were randomly divided into the normal control, photocoagulation model, photocoagulation with phosphate buffered saline (PBS control group) and photocoagulation with TGF-β receptor inhibitor groups (TGF-β receptor inhibitor group), twenty mice of each group. Fundus argon laser photocoagulation was performed in the photocoagulation model group, PBS control group and TGF-β receptor inhibitor group to induce CNV. One week, two, three and four weeks after the laser procedure, fundus fluorescein angiography (FFA) was carried out in the normal control or photocoagulation model groups to observe CNV formation dynamically. Western blot was used to analyze the expressions of TGF-β in the retina from the mice of normal control or photocoagulation model groups, and VEGF or TNF-α in the retina of normal control, PBS control or TGF-β receptor inhibitor groups. The CNV areas of each group were evaluated by using fluorescein stain on retinal pigment epithelium (RPE)/choroid flat mounts after two weeks of photocoagulation. ResultsThe FFA results showed the retinal vessels centered on the optic disc and arranged radially, while the choroidal vascular present network distribution in the normal control mice. Significant leakage of fluorescein showed discoid strong fluorophore in photocoagulation sites of retina at one week after photocoagulation. The quantitative analysis results of Western blot demonstrated that the TGF-β protein expression levels in retina of photocoagulation model mice gradually increased with time passing. The protein expression levels of TGF-β were significant differences in the photocoagulation model group comparing with the normal control group (F=13.042, P < 0.05). The protein expression levels of TNF-α (F=14.721, 17.509) and VEGF (F=18.890, 11.251) increased significantly in retina of PBS control or TGF-β receptor inhibitor groups when compared with that of normal control group at one week, two, three and four weeks after photocoagulation, and the differences were both statistically significant (P < 0.05). Compared with PBS control group, the protein levels of TNF-α and VEGF in retina from TGF-β receptor inhibitor group were significantly reduced, the differences was statistically significant (F=21.321, 16.160, P < 0.05). Two weeks after laser photocoagulation, a distinct reduction in CNV lesion size in the TGF-β receptor inhibitor group mice when compared to PBS or normal control groups, the differences was statically significant (F=4.482, P < 0.05). ConclusionTGF-β may promote CNV formation by up-regulating both TNF-α and VEGF protein expressions, the application of its specific inhibitor is able to reduce CNV progression.
Proliferative vitreoretinopathy (PVR) is a common complication and major cause of blindness of ocular trauma. Many cytokines, including vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), participate in the process of the pathogenesis of traumatic PVR. VEGF competitively inhibits binding of PDGF to its receptor (PDGFRα), enables indirect activation of PDGFRα by non-PDGF ligands, resulting in reduced p53 expression, cell proliferation and migration, which is a key point in the pathogenesis of traumatic PVR.
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.
ObjectiveTo observe the efficacy and safety of individual dose of intravitreal conbercept (IVC) in the treatment of retinopathy of prematurity (ROP) before type 1 threshold.MethodsA retrospective case study. From January to July, 2019, 23 cases (46 eyes) of children with type 1 pre-threshold ROP were included in the study. Among them, 14 cases (28 eyes) were male and 9 cases (18 eyes) were female. The mean gestational age at birth was 28.06±1.73 weeks. The average birth weight was 1.14±0.19 kg. The mean corrected gestational age was 34.38±1.41 weeks at the time of first intravitreal injection of IVC. The axial length (AL) of children was measured by A-mode ultrasound before IVC for the first time. According to the calculation of AL, the corresponding injection dose range was 14.23-16.19, 16.20-17.57, 17.58-18.63 mm and the injection dose of IVC was 0.015, 0.020, 0.025 ml (including IVC was 0.15, 0.20, 0.25 mg, respectively). The first IVC dose was 0.015 ml. On the first day before IVC and on the first and seventh days after IVC, 2 ml of arterial blood was taken from children, serum vascular endothelial growth factor (VEGF) concentration was detected. The follow-up time after treatment was ≥1 year. After one year of follow-up, the effective rate and recurrence rate of IVC for the first time were tested by χ2 tests. The short-term changes of injection times, injection intervals, retinal vascularization time and serum VEGF concentration in children were tested by t test.ResultsRetinal neovascularization subsided and vascular buckling decreased in all eyes. Iris neovascularization subsided, 1-3 weeks after IVC for the first time. Within one year after the first IVC, 16 eyes underwent IVC twice with or without new blood vessels at the junction of the vascular area. The average corrected gestational age was 40.56±3.81 weeks. The injection dose of IVC was 0.015 ml and 0.020 ml for 2 eyes and 14 eyes, respectively.The mean interval from IVC for the first time was 40.89±8.99 days. Of the 16 eyes who underwent IVC twice, 8 eyes showed neovascularization again in the retinal area with or without blood vessels. The average corrected gestational age was 43.00±1.41 weeks. The injection dose of IVC was 0.020 ml and 0.025 ml for 3 eyes and 5 eyes, respectively. The mean interval of the second IVC was 28.60±6.07 days. The mean interval from the first IVC was 69.20±12.40 days. At the end of follow-up, all eyes were treated effectively (100%, 46/46). The mean time of retinal vascularization was 46.31±3.42 weeks. The average number of injections was 1.52±0.76. On the first day before IVC and on the first and seventh days after IVC, the average serum VEGF concentrations were 111.21±148.71, 25.60±27.71 and 42.99±38.01 pg/ml, respectively. Serum VEGF concentration was significantly lower than that before IVC on the 1st and 7th day after IVC (Z=−4.054, −2.779; P＜0.05). Serum VEGF concentration was higher 7 days after IVC than 1 day after IVC, and the difference was statistically significant (Z=−2.505, P＜0.05). All eyes were not treated by laser photocoagulation or vitrectomy. No eye complications such as lens opacification, endophthalmitis and retinal detachment related to drugs or treatment methods were found in all patients.ConclusionIntravitreal injection of individualized dose of IVC is effective in the treatment of type 1 pre-threshold ROP. Seven days after treatment, serum VEGF concentration of patients’serum decreases.
The intervention therapy targeting vascular endothelial growth factor (VEGF) has become a specific and effective method for the treatment of diabetic retinopathy (DR). However, some patients did not respond or responded poorly to anti-VEGF therapy, and its effects of eliminating edema and improving vision appear to be unstable in the same patient. Hypoxia-inducible factor-1α (HIF-1α), an important upstream transcriptional regulator of VEGF, is an oxygen concentration-sensitive protein expressed in tissues under hypoxia. It can simultaneously target many downstream target genes except VEGF, such as placental growth factor and angiopoietin-like protein 4, to cause blood-retinal barrier damage and neovascularization, and thus participate in various pathological changes of DR to promote the occurrence and development of DR. Therefore, direct intervention of HIF-1α or targeting one or more downstream target genes regulated by HIF-1α to treat DR may have better efficacy. In the future, the development of effective and safe HIF inhibitors or anti-VEGF with HIF-1α other target gene inhibitors may have broader clinical application prospects.
Objective To observe the effect of celecoxib on the expression vascular endothelial growth factors (VEGF) in diabetic rats. Methods Thirty-six wistar rats were used to establish the diabetic models by intraperitoneal injection with streptozotocin. The diabetic rats were divided into 2 groups: diabetic group (n=18) and celecoxib group (n=18). Celecoxib (50 mg/kg) was administered orally to the rats in celecoxib group and the physiological saline with the same volume was given orally to the rats in diabetic group. Eighteen else rats were in normal control group. All of the rats were executed 3 months later. The expression of VEGF protein was detected by immunohistochemistry method. Reverse transcription-polymerase chain reaction（RT-PCR） analysis was used to examine the expression of retinal VEGF mRNA and cyclooxygenase-2 mRNA. Results Lower positive expression of VEGF mRNA and cyclooxygenase-2 mRNA, weakly positive action of immunohistochemistry of VEGF, and lower expression of VEGF protein were detected in normal control group; in the diabetic group, the expression of VEGF mRNA and cyclooxygenase-2 mRNA increased obviously comparing with which in the control group (Plt;0.05), and the bly positive action of immunohistochemistry of VEGF and increased expression of VEGF protein were detected (Plt;0.01); in celecoxib group, the expression of VEGF mRNA was lower than that in the diabetic group (Plt;0.05), the expression of cyclooxygenase-2 mRNA didnprime;t decrease much (Pgt;0.05), the positive action of immunohistochemistry of VEGF decreased, and the expression of VEGF protein decreased (Plt;0.01). Conclusion By inhibiting the activation of cyclooxygenase-2, celecoxib can inhibit the expression of retinal VEGF mRNA and protein in diabetic rats induced by streptozotocin. (Chin J Ocul Fundus Dis,2007,23:265-268)
Objective To investigate the expression of pigment epitheliumderived factor (PEDF) and vascular endothelial growth factor (VEGF) in choroidal melanoma. Methods The expression of VEGF and PEDF protein in fifty-eight cases of paraffinembeded choroidal melanoma samples was measured by immunohistochemistry, the expression of PEDF mRNA in thirtynine choroidal melanoma samples was assayed by in situ hybridization. Results PEDF protein was detected in 13/58 cases (22.4%) of choroidal melanoma, the positive rate in nonsclerainvasion group (12/38, 31.6%) was higher (Plt;0.05) than that in sclerainvasion group (1/20, 5%). VEGF protein was detected in 43/58 cases (64%) of choroidal melanoma, the positive rate in nonsclerainvasion group (25/38, 65.8%) was lower (Plt;0.05) than that in sclerainvasion group (18/20, 90%). The expression of PEDF mRNA was detected in 18/39(46.2) cases, the positive rate in nonsclerainvasion group was higher (Plt;0.05) than that in sclerainvasion group. Conclusions Imbalanced expression of VEGF and PEDF in choroidal melanoma may play a key role in the angiogenesis, tumor progression and metastasis.
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.