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 observe the effects of high concentr at ion glucose on the calcium-activated potassium channel of rabbits′ retinal Müller cells. Methods The rabbits′retinal Müller cells were cultured in vitro under the condition of high concentration glucose, and identified by immunohistochemical staining and transmission electron microscopy. Patch-clamp technique was used to observe the changes of the calcium-activated potassium channel of retinal Müller cells caused by high concentration glucose at different time.Results High concentration glucose could inhibit the calcium-activated potassium channel of cultured retinal Müller cells in a time-dependent manner. Conclusion High concentration glucose may reduce the biological functions of Müller cells by inhibiting calcium-activated potassium channel. (Chin J Ocul Fundus Dis，2003，19：164-167)
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 study the effect of serum rich in growth factors (SRGF) derived from plateletrich plasma (PRP) on the biological function of human and rat osteoblast.Methods PRP and platelet-poor plasma (PPP) obtained from healthy human and SD rat were activated by thrombin toget SRGF and serum poor in growth factors (SPGF). The level of TGFβ1 and PDGF-AB in human-SRGF and SPGF were assayed by enzyme-linked immunoassay(ELISA). Rat and human osteoblast were cultured and identified. Rat osteoblasts were treated with 5% rat-SRGF, 5% rat-SPGF and serumfree F12 medium, respectively. And human osteoblast were treated with 5% human-SRGF, 5% human-SPGF and serumfree DMEM. Cellular mitogenic activity was evaluated by thiazoly blue (MTT) colorimetric assay at 24, 48, 72 and 96hours.Results The level of TGF-β1 in human-SRGF was 307.67±35.57 ng/ml, and that of PDGF-AB was 52.76±7.89 ng/ml. The proliferation of rat and human osteoblast were promoted after treated with rat-SRGFand human-SRGF, respectively. In rat osteoblast groups, there were significant differences in absorbency between ratSPGF group and rat-SRGF group at 48 and 96 hours(Plt;0.05). In human osteoblast groups, the differences between human-SPGF group and human-SRGF group were significant at 48, 72 and 96 hours(Plt;0.05). The proliferation of these two kinds of osteoblasts almost stopped in serum-free medium, and the differences in absorbency , compared with othergroups，were significant (Plt;0.05). Conclusion High quality of PRP can be achieved by the improved method and SRGF is capable of up-regulating the proliferation of rat osteoblast and human osteoblast.
Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
Objective
To investigate the effects of advanced glycation endproducts (AGEs) on proliferation of pericytes of bovine retinal capillary vessels and expression of transforming growth factor beta;(TGF-beta;).
Methods
The proliferation of pericytes detected by methyl thiazolyl tetrazolium (MTT) colorimetric assay, cellular cycle of pericytes was analyzed by flow cytometry was used to analyze cell, and TGF-beta; protein expression of pericytes was observed by immunofluorescent staining.
Results
AGEs inhibited the proliferation of pericytes of bovine retinal capillary vessels, stopped the cellular cycle of pericytes in synthesis phase (S phase), increased the number of apoptotic cells obviously (Plt;0.01), and promoted the expression of TGF-beta; proteinof perycytes.
Conclusions
AGEs may promote the apoptosis of pericytes by inhibiting the proliferation of pericytes to lead the decrease of pericytes number, and may accelerate diabetic retinopathy by promoting the expression of TGF-beta; protein of pericytes.
(Chin J Ocul Fundus Dis, 2006, 22: 20-23)
Objective To determine the association between the geneti c polymorp hisms of vascular endothelial growth factor (VEGF) gene and the prognosis for retinopathy of prematurity (ROP) in Chinese. Methods Twenty infants with threshold ROP who had undergone retinal photocoagulation were in the treated group and 20 infants with self-regressed ROP without any treatment were in the control grou p . In the two groups, all the infants had oxygen-breathing history and the sex a n d gestational age were all suitable to be compared, except birth weight. Polymer ase chains reaction-restriction fragment length polymorphism was used to determine the frequencies of VEGF genes in the two groups. Results The frequencies of +405C allele were higher in the treated group than those in the control group (P＜0.05). The frequencies of the VEGF-460T/C and +936C/T ploymorphisms were similar in both groups (P＞0.05). Conclusions The +4 05C/G ge netic polymorphisms of VEGF may correlate to the prognosis of ROP. The carriers of +405CC allele are more susceptible to ROP.
ObjectiveTo observe the effect of conditional knocking out (KO) vascular endothelial growth factor (VEGF) gene on the mouse model of oxygen induced retinopathy (OIR).MethodsThe conditional VEGF KO mice were generated using Cre-Loxp technology, resulting in the deletion of VEGF in a portion of Müller cells permanently in mouse retina. Cre positive was CKO mice, Cre negative was NKO mice. OIR was induced by keeping mice in 75% oxygen at postnatal 7 days (P7) to P12 and in room air from P12 to P17 (each 20 mice for CKO and NKO, respectively). The mice mortality was analyzed. At day P17, the percentage of retinal avascular area was calculated using retinal flat-mounting with fluorescence angiography, the number of vascular endothelial cell nucleus breaking through retinal inner limiting membrane was counted with hematoxylin eosin (HE) staining of retinal sections, and the expression of hypoxia-inducible factor-1α (HIF-1α) was detected by immunofluorescence analysis. ResultsDuring the development of OIR, the mortality rate of CKO mice (65.00%) was higher than that of NKO mice (30.00%) with the significant difference (x2=4.912, P=0.027). At day P17, all the mice retinas were harvested. The retinal fluorescence angiography displayed that the normal retinal vascularization of CKO mice was delayed, and large avascular areas were observed. Meanwhile, rare new vascular plexus was found in CKO mice and the thickness of whole retina decreased dramatically. In contrast, NKO mice developed larger area of normal retinal vascular network structure with higher blood vessel density and more new vascular plexus with obvious fluorescein leakage. The percentage of avascular area in CKO mice [(28.31±11.15)%] was higher than NKO mice [(16.82±7.23)%] with the significant difference (t=2.734, P=0.014). The HE staining of retinal sections indicated smaller counts of vascular endothelial cell nucleus breaking through retinal inner limiting membrane in CKO mice (26.10±6.37) when compared to NKO mice (28.80±7.59) , the difference was significant (t=2.437, P=0.016). The immunofluorescence analysis showed stronger expression of HIF-1α in CKO mice than NKO mice, which was mainly located in the retinal ganglion cell layer.ConclusionsThe local VEGF gene knockout partially inhibits retinal neovascularization in OIR mice. However, it also suppresses the normal retinal blood vascular development with a decrease of OIR mice survival ability.
ObjectiveTo analyze the concentrations of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in aqueous humor of patients with proliferative diabetic retinopathy (PDR) before and after intravitreal injection of ranibizumab.
MethodsTwenty-five eyes of 20 PDR patients were collected as the PDR group. Twenty-five eyes of 21 senile cataract patients were collected as the control group. There were no statistical significance in gender (χ2=0.223), age (Z=-1.555) and intraocular pressure (Z=-0.225) between the two groups (P > 0.05). Samples of aqueous humor (0.1 ml) were collected just before and 7 days after the injection of ranibizumab in PDR group. Samples of aqueous (0.1 ml) humor were collected just before cataract surgery in control group. The concentrations of VEGF and PEDF in the aqueous humor were measured by enzyme-linked immunosorbent assay.
ResultsThe VEGF and PEDF concentration in the aqueous humor were reduced significantly after intravitreal injection of ranibizumab in PDR group (Z=-4.072, -4.319; P < 0.05). The concentrations of VEGF and PEDF in the aqueous humor before intravitreal injection of ranibizumab in PDR group were significantly higher than the control group (Z=-5.228, 4.706; P < 0.05). The VEGF concentration in the aqueous humor after intravitreal injection of ranibizumab in PDR group were similar to control group (Z=-1.557, P > 0.05). However, the concentration of PEDF in the aqueous humor after intravitreal injection of ranibizumab in PDR group still higher than control group (Z=-2.475, P < 0.05). The ratio of VEGF/PEDF before and after intravitreal injection of ranibizumab was statistically different (Z=-2.058, P < 0.05), but was the same between PDR group and control group (Z=-0.456, -0.844; P > 0.05). The aqueous humor concentrations of VEGF and PEDF were not significantly correlated with each other, neither in PDR group (r=-0.195, -0.174; P > 0.05) nor in control group (r=-0.286, P > 0.05).
ConclusionsAqueous humor concentrations of VEGF and PEDF are significantly elevated in eyes with PDR. Intravitreal injection of ranibizumab significantly decreased the VEGF and PEDF in the aqueous humor after 7 days.
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.
