| Research BasicsProliferative diabetic retinopathy(PDR)is a severe complication of diabetes,which has a great impact on the patient's visual function.The pathogenesis of PDR involves a huge regulatory network.The molecular imbalance of promoting and inhibiting retinal neovascularization is an important biological feature for aggravating the progression of PDR.PDR is characterized by extensive retinal neovascularization,and then vitreous hemorrhage and(or)tractional retinal detachment caused by vascular leakage and rupture.Eventually,it may lead to irreversible blindness.A growing body of evidence have demonstrated that glycosylation can promote neovascularization by affecting the activation,proliferation and migration of endothelial cells as well as the interaction between endothelial cells and other cells necessary to angiogenesis.?-galactoside-binding lectins(Galectins)may be an important regulator during the above process.Galectins are a kind of evolutionarily conserved galactoside-binding lectins that can regulate a variety of biological responses in the absence of specific receptors such as cytokines.Galectin-1 and Galectin-3 are the most widely studied members of the Galectins family.Carbohydrate-based recognition plays an important role in inflammation and neovascularization,and probably plays a certain role in the pathogenesis and complications of diabetes,which provides a new breakthrough point for the related research of PDR.ObjectiveTo explore the role of Galectin-1 and Galectin-3 in PDR and the possible related molecular biological mechanism by detecting the levels of Galectin-1,Galectin-3 and VEGF-A in serum,aqueous humor and vitreous body of patients with PDR,and to provide new ideas and targets for the study of pathogenesis,prevention and treatment of PDR.MethodsIn this study,42 patients(42 eyes)with PDR were enrolled in the Department of Ophthalmology,First Affiliated Hospital of Zhengzhou University from January 2019 to October 2019.The PDR group included 23 males and 19 females.The age of the patients in PDR group ranged from 47 to 74 years,and the mean age was 55.4±10.5 years.All patients underwent 23G vitrectomy.Intravitreal injection of Ranibizumab(anti-VEGF-A monoclonal antibody)was performed three days before the vitrectomy.The control group included 30 patients(30 eyes)with idiopathic macular hole.The cases included 12 males and 18 females.The age of patients in the control group ranged from 49 to 69 years,and the mean age was 59.5±11.2 years.Approximately 5 mL blood from median cubital vein of all subjects were collected,of which 3 mL blood was used to determine routine biochemical indexes,and another 2 mL blood was centrifuged to take the supernatant of 0.3 mL.Under the microscope,a 0.33 mm needle was used to insert into the anterior chamber at the 1 mm of the limbus of all subjects,and about 80-100?L of the undiluted aqueous humor was slowly extracted.Vitreous samples about 0.5-0.8 mL were obtained during the beginning of 23G standard three-channel vitrectomy with the closed perfusion.0.1 mL of the supernatant was taken after centrifugation.All samples were stored in the Eppendorf tubes at-80? immediately for testing.The levels of Galectin-1,Galectin-3 and VEGF-A in all samples were detected by ELISA.IBM SPSS 19.0 statistical software was used to analyze all the data.Differences between two independent samples were compared using t-test and Kruskal-Wallis nonparametric test.Paired sample t-test was used to analyze the paired data.And chi-square test was used to analyze the classified data.Results1.In this study,there was no significant difference in the levels of Galectin-1,Galectin-3 and VEGF-A in serum between the PDR group and the control group(1.64±0.69 vs 1.43±0.72 ng/mL,t?1.228,P?0.224;1181.27±537.78 vs 972.27±515.58 pg/mL,t?1.654,P?0.103 and 24.39±8.67 vs 22.14±6.44 pg/mL,t?1.208,P=0.231,respectively).2.Before the anti-VEGF treatment(intravitreal injection of Ranibizumab),the concentration of Galectin-1,Galectin-3 and VEGF-A in aqueous humor of the PDR group were significantly higher than those in the control group(1.14±0.56 vs 0.76±0.24 ng/mL,t?2.619,P=0.011;617.33±312.09 vs 382.28±219.69 pg/mL,t?2.491,P=0.015 and 104.97±26.71 vs 20.56±7.82 pg/mL,t?16.775,P<0.001,respectively).3.Three days after the anti-VEGF treatment,the concentration of Galectin-1,Galectin-3 in aqueous humor of the PDR group were significantly higher than those in the control group(1.25±0.59 vs 0.76±0.24 ng/mL,t?2.725,P?0.008 and 568.69±317.53 vs 382.28±219.69 pg/mL,t?2.437,P=0.017,respectively).There was nosignificant difference in the concentration of VEGF-A in aqueous humor between the PDR group and the control group(24.23±8.83 vs 20.56±7.82 pg/mL,t=1.822,P?0.073).4.In the PDR group,the concentration of VEGF-A in aqueous humor before the anti-VEGF treatment was higher than that three days after the anti-VEGF treatment(104.97±26.71 vs 24.23±8.83 pg/mL,t=23.456,P<0.001),while there was no statistical difference in the concentration of Galectin-1 and Galectin-3 in aqueous humor before and after the anti-VEGF treatment(1.14±0.56 vs 1.25±0.59 ng/mL,t=-1.610,P=0.112 and 617.33±312.09 vs 568.69±317.53 pg/mL,t=1.767,P?0.081,respectively).5.The levels of Galectin-1 and Galectin-3 in vitreous body in the PDR group were significantly higher than those in the control group(2.71±0.77 vs 1.01±0.55 ng/mL,t=10.310,P<0.001 and 1982.19±1057.47 vs 1286.85±543.95 pg/mL,t=3.299,P?0.002,respectively).While,there was no statistical difference in the level of VEGF-A in vitreous body between the PDR group and the control group(30.12±11.96 vs 25.90±7.92 pg/mL,t?1.684,P?0.097).Conclusions1.The increased levels of Galectin-1 and Galectin-3 in the eyes of PDR patients suggesting that Galectin-1 and Galectin-3 may participate in the pathogenesis of PDR.2.The ocular levels of Galectin-1 and Galectin-3 in the patients with PDR may not be affected by intravitreal injection of Ranibizumab,suggesting that Galectin-1 and Galectin-3 may not depend on VEGF to regulate the pathogenesis of PDR.3.The levels of Galectin-1 and Galectin-3 in serum may not be used as auxiliary indicators to indicate the condition of PDR. |
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