Objective To investigate the effect of pigment epitheliumderived factor (PEDF）on the expression of glutamine synthetase in retinal Muuml;ller cells of diabetic rats.Methods Diabetic rats were induced with streptozotocin injection.Before and after injection of 10 mu;l (0.1 mu;g/mu;l) PEDF (experimental group) or 10 mu;l PBS (control group) into the vitreous cavities of diabetic rats respectively for 48 hours,the expressions of GS and IL-1beta; in retina were analyzed by immunohistochemistry and real time RTPCR techniques. After being treated with 100 ng/ml PEDF for 24 hours in high glucose conditions,the expressions of GS and IL-1beta; in cultured Muuml;ller cells were studied by western blot and real time RT-PCR techniques. Apoptosis was analyzed by flow cytometry after Annexin V fluorescein isothiocyanate/Propidium idoium (Annexin V-FITC/PI) staining.Results By immunohistochemistry (the protein level) and real time RT-PCR (the mRNA level),it was found that the expression of GS decreased and the expression of IL-1beta; increased obviously (real time RT-PCR：GS:t=4.23,P＜0.01；IL-1beta;:t=16.73,P＜0.01；immunohistochemistry：GS: t=5.13,P＜0.01；IL-1beta;:t=9.32,P＜0.01) in diabetic rats. After injection of 10 mu;l (0.1 mu;g/mu;l) PEDF into the vitreous cavities of diabetic rats for 48 hours,it was found that the expression of GS increased and the expression of IL-1beta; decreased significantly(RT-PCR GS:t=3.87,P＜0.01IL-1beta;:t=3.61,P＜0.05;immunohistochemistry:GS:t=3.32, P＜0.05；IL-1beta;: t=2.63,P＜0.05). Under high glucose conditions, 100 ng/ml PEDF induced decreasing expression of IL-1beta; and increasing expression of GS significantly (RT-PCR：GS: t=2.89, P＜0.05；IL-1beta;: t=3.37,P＜0.05；Western blot：GS:t=2.66,P＜0.05;IL-1beta;:t=3.23,P＜0.05).Apoptosis of Muuml;ller cells under high glucose conditions was inhibited significantly by the treatment with 100 nmol/ml PEDF (t=3.21,P＜0.05). Conclusions In diabetic rats,PEDF may decrease expression of IL-1beta; in rat retinal Muuml;ller cells, which may result in increasing expression of GS.To some degree,it inhibits possibly the death of retinal ganglion cells.
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 investigate the effects of recombinant adeno-associated virus type-2 (rAAV2) mediated delivery of pigment epitheliumderived factor (PEDF) on oxygen-induced retinal neovascularization (OIRNV) in mice. Methods A total of 22 C57/BL6 mice at the age of 3 days received intravitreal injections of 1 mu;l rAAV2-PEDF and rAAV2EGFP into the left eyes (experimental group) and the right eyes (control group). All mice were put into the oxygen box right after the injection to induce the OIRNV model.4 mice were sacrificed and PEDF protein in retina was measured by western blot at postnatal days 13 (P13). Twelve mice underwent retinal angiography with high molecular weight fluoresceindextran, and another 6 mice were sacrificed for retinal lectin immunohistochemistry staining at P17. Absolute and relative nonperfusion areas of retinal neovascularization were analyzed by Image-Pro Plus 5.1 software. Results The expression level of PEDF protein was higher in the experimental group than that in the control group.The absolute nonperfusion area was (0.96plusmn;0.22) mm2 in the experimental group and (1.96plusmn;0.34) mm2 in the control group; the difference between the two groups was significant（t=-8.554, P＜0.01）. The relative nonperfusion area was (8.64plusmn;1.52)% in the experimental group and (17.27plusmn;2.98)% in the control group with a significant difference between the two groups (t=-8.97, P＜0.01).The absolute area of retinal neovascularization was (0.37plusmn;0.11) mm2 in the experimental group which was obviously higher than (1.26plusmn;0.38) mm2 in the control group (t=-7.8, P＜0.01); the relative areas in experimental and control groups was (3.96plusmn;0.66)% and (11.45plusmn;2.06)%, respectively, whose difference is apparently(t=-8.51, P＜0.01).The areas of retina neovascularization were (0.11plusmn;0.003) mm2 and (0.41plusmn;0.02) mm2 in the experimental and control groups, respectively, and the difference between the two groups was significant（t=-5.14, P＜0.01）.Conclusions PEDF protein can stably express in the mice retina after rAAV2-PEDF transfetion. rAAV2-PEDF can decrease the retinal non-perfusion areas and inhibit the retinal neovascularization in OIRNV mice.
Objective To evaluate the effects of inflammatory cytokines, including tumor necrosis factorTNF-alpha; and interleukins (IL-6 and IL-8), to the expression of pigment epithelium-derived factor (PEDF) in human retinal pigment epithelium (RPE)cells. Method Cultured primary human RPE cells were treated with 20，2，0.2 , and 0.02 ng/ml of TNF-alpha;, IL-6 and IL-8 separately. The levels of PEDF expression were determined by Western blot of the supernant after 6，12，24 and 48 hours of culture. Results PEDF secretion of RPE cells was inhibited by TNF-alpha;, IL-6 and IL-8 in a time- and dose-dependent fashion. Compared with the controls, the expression of PEDF decreased significantly in 0.02 ng/ml and 6 hours group (F＝7.14, P＜0.05）, 2.00 ng/ml and 48 hours group（F=14.05，P＜0.01) , and 20.00 ng/ml and 24 hours group（F=11.53，P＜0.01). TNF-alpha; was the most strength inhibitor (F＝14,P＜0.01）.Conclusion TNF-alpha;, IL-6, and IL-8 could suppress the expression of PEDF in the cultured human RPE cells.
Objective To observe the interferon-gamma; (IFN-gamma;), interleukin-2 (IL-2) levels of Th1 cytokine and IL-4、IL-10 levels of Th2 cytokine in serum and culture supernatants of splenic cells of the rats in the prevention of experimental autoimmune uveoretinitis（EAU）by oral tolerance. Methods 72 Lewis rats were randomly divided into EAU group，oral tolerance group (which including 10 mu;g、100 mu;g、1 mg、10 mg of S antigen group respectively) and control group，12 rats in each group. The animal model of EAU was induced by immunization with S antigen（50 mu;g）and Freundrsquo;s complete adjuvant. Oral tolerance 10 mu;g、100 mu;g、1 mg and 10 mg group were fed with 1 ml mixture of 10 mu;g、100 mu;g、1 mg、10 mg S antigen and 1 mg trypsin inhibitor respectively by intubation，once the other day，totally 7 times，and then induced EAU according to above methods；control group was fed with 1 ml mixture of phosphate buffered saline and 1 mg trypsin inhibitor，once the other day，totally 7 times，and then induced EAU. The clinical manifestation of EAU in the eye were recorded,the eyeballs were enucleated at the peak of EAU，followed by pathological grading. Meanwhile the serum was colleced; splentic cells were separated and cultured to collect the supernatant. Cytokine levels of IFN-gamma;, IL-2, IL-4 and IL-10 in serum, cultured supernatant of splenic cells were determined by enzyme-linked immunosorbent assay (ELISA). Results Compared with EAU and control group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the serum in 100 mu;g and 1 mg group were decreased while the levels of IL4 and IL10 (Th2 cytokine) were increased，the differences were statistically significant（F=51.9, 68.8, 35.7,7.5,P＜0.01). Compared the levels of Th1 and Th2 cytokines in the serum in 10 mu;g, 10 mg group with EAU and control group, the differences were not statistically significant. In 100 mu;g、1 mg group, the levels of IFN-gamma; and IL-2 (Th1 cytokine) in the culture supernatant of splenic cells were decreased while the levels of IL-4 and IL-10 (Th2 cytokine) were increased, compared with EAU and control group, the differences were statistically significant（F=57.1,15.6,33.1,167.7, P＜0.01）. Compared the levels of Th1 and Th2 cytokine in the culture supernatant of splenic cells in 10 mu;g、10 mg groups with EAU and control group, the difference are not statistically significant. Conclusions In the process to prevent EAU by oral intake, the levels of IFN-gamma; and IL-2 (Th1 cytokine ) were decrease while the levels of IL-4 and IL-10 (Th2 cytokine). Oral administration with too high or low dose of the antigen can not prevent EAU as well as the cytokine levels do not change obviously. Cytokines has played an important role in the prevention of EAU.
Objective To observe the expression and investigate the significance of suppressor of cytokine signaling (SOCS) in peripheral blood mononuclear cells (PBMC) of experimental autoimmune uveitis (EAU). Methods 100 Lewis rats were immunized with interphotoreceptor retinoid-binding protein (IRBP) to induce EAU animal model, and they were divided into control group and treatment group randomly. The treatment group was administered cyclosporine A 20mg/（kgmiddot;d）after 1 to 28 days of immunization; the control group received saline buffer at equal quantity. All eyes were evaluated by slit-lamp microscopy before and after 7, 14, 21, 28 days of immunization; IL-4，IL-12，IFN-gamma; in the serum were measured by enzyme linked immunosorbent assay(ELISA); the SOCS mRNA and protein level in PBMC were measured by quantitative polymerase chain reaction (q-PCR) and western blot. Results The inflammation was most obvious at 14 days after immunization. The control group showed obvious iridocyclitis; the treatment group showed mild anterior chamber inflammation but no posterior synechia and hypopyon. The highest level of IL-12 and IFN-gamma; were observed at 14 days after immunization, followed by decline to the baseline at 28 days after immunization in control group; the highest level of IL-12 and IFN-gamma; were found at 14 days after immunization in treatment group, but the level was lower than control group obviously. Compared with the level before immunization, there are no differences at other time-point. The concentration of IL-4 decreased indistinctly in control group but increased in treatment group. SOCS1、Both of SOCS1 and SOCS5 increased to the highest level at 14 days after immunization, as 4.05 and 383 times of preimmunization in control group respectively, as 1.15 and 1.16 times in treatment group respectively. The CIS and SOCS3 mRNA increased lightly in two groups and treatment group milder than control group. Marked increased expression of SOCS1 and SOCS5 protein was detected at 7, 14, 21days than preimmunization, both of CIS and SOCS3 protein were significantly increased on 14, 21 days in control group; only SOCS1 protein was significantly increased on 14 days in treatment group and there are no differences at other time-point compared to pre-immunization. Conclusion Up-regulation of SOCS1 and SOCS5 expression maybe related to intensive response of Th1 in the development of EAU. Mild up-regulation of CIS and SOCS3 maybe associated with intensive response of Th2 which against the reaction of Th1 to carry out the dynamic immune balance.
Blood-retina barrier destruction, nerve injury, formation of neovascularization and fibroblast proliferation membrane are important pathological changes of DR, which are related to the combined effects of various vitreous cytokines. VEGF is mainly involved in increasing retinal vascular permeability and inducing neovascularization. Pigment epithelium derived factor is vital reducing vascular permeability and neuroprotection; IL plays a key role in mediating inflammatory response. TNF-α is related to inflammation, which is significantly up-regulated by hypoxia. TGF-β is an important cytokine regulating cell proliferation and differentiation. Connective tissue growth factor can promote the growth, migration and adhesion of endothelial cell. In addition, many other molecular mechanisms have not been fully elucidated, and further study on the molecular mechanism of DR is urgent. With the further study of molecular mechanism, the early intervention and targeted treatment of DR will be more effective.
ObjectiveTo study the changes and correlation of cytokines in aqueous humor before and after intravitreal injection of conbercept (IVC) treatment in patients with proliferative diabetic retinopathy (PDR).MethodsA prospective clinical study. From March to December 2019, 36 patients (42 eyes) of PDR patients treated with IVC combined with pars plana vitrectomy (PPV) (the observation group) and 27 patients (31 eyes) underwent cataract surgery in the same period (control group) in Department of Ophthalmology of the First Affiliated Hospital of Guangzhou University of Chinese Medicine were included in this study. Before PPV 5-7 days, IVC treatment was performed, and the aqueous humor were extracted during IVC and second-stage PPV in the observation group. The aqueous humor was extracted during cataract surgery in the control group. Luminex assay was used to detect VEGF-A, placental growth factor (PLGF), platelet-derived growth factor-AA (PDGF-AA), platelet-derived growth factor-BB (PDGF-BB), angiopoietin-like protein 4 (ANGPTL4), IL-6, IL-8, IL-1β, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α) cytokine expression. For normally distributed data, the independent sample t test was used for comparison between two independent samples; for non-normally distributed data, the Wilcoxon rank sum test was used for comparison between two independent samples. The correlation analysis used Spearman rank correlation test.ResultsBefore IVC treatment, the concentrations of VEGF-A, PLGF, PDGF-AA, ANGPTL4, IL-6, IL-8, MCP-1 and ICAM-1 in the aqueous humor of PDR patients were significantly higher than those in the control group (P＜0.05). After IVC treatment, the concentration of VEGF-A in the aqueous humor was significantly lower than that before treatment, and the concentrations of ANGPTL4 and IL-8 were significantly higher than those before treatment (P＜0.05). There were no significant differences in the concentrations of PLGF, PDGF-AA, PDGF-BB, IL-6, IL-1β, MCP-1, ICAM-1 and TNF-α before and after IVC treatment (P＞0.05). Before IVC treatment, the concentration of VEGF-A was positively correlated with PLGF, PDGF-AA, PDGF-BB, ANGPTL4, IL-6, IL-8, MCP-1 and TNF-α (P＜0.05).ConclusionsIVC treatment can reduce the concentration of VEGF-A and increase the concentrations of ANGPTL4 and IL-8 in aqueous humor in PDR patients before PPV.