Vascular endothelial growth factor/connective tissue growth factor and proteomic analysis of aqueous humor after intravitreal conbercept for proliferative diabetes retinopathy

AIM:To investigate the role of connective tissue growth factor(CTGF)and vascular endothelial growth factor(VEGF)in the protein profile of the aqueous humor in patients with proliferative diabetic retinopathy(PDR)following intravitreal injection of conbercept.METHODS:This study included 72 PDR patients and 8 cataract patients as controls.PDR patients were divided into 3 groups according to the intervals of 3,5,and 7d between intravitreal conbercept(IVC,0.5 mg/0.05 mL)injection and pars plana vitrectomy(PPV)performed.Aqueous humor samples were collected before and after IVC and PPV for VEGF and CTGF levels detected with enzyme-linked immunosorbent assay(ELISA).The differential proteomics of 10 patients who underwent PPV surgery 5d after IVC and 8 normal controls was studied,Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis were performed on the data,and the protein interaction network of 23 differential proteins was studied.RESULTS:Post-IVC,VEGF levels decreased and CTGF levels increased significantly in aqueous humor,with the CTGF/VEGF ratio rising significantly at all intervals.Liquid chromatography tandem mass spectrometry(LC-MS/MS)identified differentially expressed proteins between preand post-IVC samples.GO and KEGG analyses revealed involvement in immune response,stress response,complement and coagulation cascades,ferroptosis,and PPAR signaling pathways.PPI analysis highlighted key proteins like APOA1,C3,and transferrin(TF).ELISA assay confirmed the differential expression of proteins such as HBA1,SERPINA1,COL1A1,and ACTB,with significant changes in the IVC groups.CONCLUSION:The study demonstrates that IVC effectively reduces VEGF levels while increasing CTGF levels,thereby modifying the CTGF/VEGF ratio,and IVC significantly alters the protein profile in the aqueous humor of patients with PDR.Proteomic analysis reveals that these changes are associated with critical biological pathways and protein interactions involved in immune response,stress response,and cellular metabolism.

Streptozotocin induced diabetic retinopathy in rat and the expression of vascular endothelial growth factor and its receptor

·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene expression of vascular endothelial growth factor (VEGF) and its receptors during the development of DR. ·METHODS: A rat model of diabetes was established by intraperitoneal injection of STZ. The diabetic rats were housed for 2, 3 and 4 months after the development of diabetes. Retinal histopathological observation was performed. The retinal vessels were observed by immunofluorescence staining by CD31. The mRNA expression of VEGF, VEGF receptor 1 and 2 (VEGFR1/2) in rat retina was detected by reverse transcription - polymerase chain reaction (RT-PCR) analysis. · RESULTS: Retinal histopathological observation showed the morphological changes of inner nuclear layer (INL) and outer nuclear layer (ONL) at any time -point, and also demonstrated the increased new vessels at both 3, 4 months after the development of diabetes. The CD31 staining results showed that the number of vessels was increased in the retinas of diabetic rats at both 3 and 4 months after the development of diabetes. As compared to the normal rats, the mRNA expression of VEGF was increased in retinas of diabetic rats at 3 months after the development of diabetes, while VEGFR1 and VEGFR2 mRNA expression was increased at 2, 3 and 4 months after the development of diabetes.·CONCLUSION:Takentogether,ourresultsdemonstrated that DR was occurred at 3 months after the development of diabetes, and the mRNA expression of VEGF, VEGFR1 and VEGFR2 were increased in the process of DR. The present study further evidenced the involvement of VEGF and its receptors in the process of DR. ·

Functions of Müller cell-derived vascular endothelial growth factor in diabetic retinopathy

Müller cells are macroglia and play many essential roles as supporting cells in the retina.To respond to pathological changes in diabetic retinopathy(DR),a major complication in the eye of diabetic patients,retinal Müller glia produce a high level of vascular endothelial growth factor(VEGF or VEGF-A).As VEGF is expressed by multiple retinal cell-types and Müller glia comprise only a small portion of cells in the retina,it has been a great challenge to reveal the function of VEGF or other globally expressed proteins produced by Müller cells.With the development of conditional gene targeting tools,it is now possible to dissect the function of Müller cell-derived VEGF in vivo.By using conditional gene targeting approach,we demonstrate that Müller glia are a major source of retinal VEGF in diabetic mice and Müller cell-derived VEGF plays a significant role in the alteration of protein expression and peroxynitration,which leads to retinal inflammation,neovascularization,vascular leakage,and vascular lesion,key pathological changes in DR.Therefore,Müller glia are a potential cellular target for the treatment of DR,a leading cause of blindness.

Association of vascular endothelial growth factor-634G/C and receptor for advanced glycation end products G82S gene polymorphisms with diabetic retinopathy

AIMTo investigate the association of receptor for advanced glycation end products (RAGE) G82S and vascular endothelial growth factor (VEGF) -634 G/C gene polymorphisms with diabetic retinopathy (DR).METHODSOur cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy (PDR), 15 had non proliferative diabetic retinopathy (NPDR), 34 had no diabetic retinopathy (NDR) and 61 healthy controls. Participants were tested for RAGE G82S and VEGF -634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTSWe found a significant association between VEGF -634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF -634 CC genotype compared to NDR patients [odds ratio for CC vs (GC+GG)=6.5, 95% CI=1.5-27.8, P=0.021]. Also VEGF -634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study (P=0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype (P=0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSIONPatients carrying VEGF -634 C polymorphism have a higher risk of PDR development, so VEGF -634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.

Dan Huang Ming Mu Recipe Suppresses the Progression of Streptozotocin-induced Diabetic Retinopathy After Retinal Laser Photocoagulation in Brown Norway Rats via Down-regulating Vascular Endothelial Growth Factor and Up-regulating Pigment Epithelium-derived

Objective To analyze the effects of Dan Huang Ming Mu Recipe(DHMMR)(a pharmaceutical preparation from herbs and having the function of replenishing vital essence,removing heat,promoting blood circulation and excreting pathogenic water) on diabetic retinopathy(DR) after retinal laser photocoagulation through regulating the expression of vascular endothelial growth factor(VEGF) and pigment epithelium-derived factor(PEDF).Methods Forty male Brown Norway(BN) rats were randomly divided into blank group(group A,10 BN rats) and model group(30 BN rats).DR models were induced by 40 mg/kg streptozotocin(STZ) and the body weight and blood glucose of rats were monitored.After 12-week injection,fluorescein fundus angiography(FFA) and histopathological examination were detected to confirm the successful establishment of DR models.Subsequently,the right eyes of model group rats were conducted retinal laser photocoagulation with the left eyes having no retinal laser photocoagulation and rats of the model group were randomly divided into group B(the model control group),group C(the positive control group),and group D(the DHMMR group),with 10 rats in each group.Rats of the group A and the group B were given vehicle,and the group C were given calcium dobesilate suspension by gavage,and the group D were given DHMMR by gavage.After 4-week gavage,FFA was carried out to observe the fundus microvascular change.Then,the rats were sacrificed to do histopathological examinations and the serum levels of P-selectin,cAMP,cGMP,and the relative expression of the protein of VEGF and PEDF in retina were detected.Results After 12-week STZ injection,the blood glucose of the model group were pronouncedly higher than the blank group(P < 0.01).Fundus micro-hemangioma changes were observed in the rats of the model group through FFA,and the rats of the blank group did not see any changes.The pictures of HE staining showed that the retinal structure of the model group was more disordered than the blank group.After 4-week gavage,treatments with DHMMR showed dramatic reduction of serum levels of Pselectin,cAMP and cGMP compared with the group B(P < 0.01).FFA and histopathological examinations of DHMMR-treated rats revealed significantly suppression of retinal edema,fundus microvascular destruction and retinal destruction distinguishing from the group B.And the relative expression of VEGF protein of the group D and the group A was markedly lower than that of the group B(P < 0.01).The relative expression of PEDF protein of the group D and the group A was dramatically higher than that of the group B to the contrary(P < 0.01).Conclusions DHMMR demonstrates pronounced suppressive effects on the progression of DR after retinal laser photocoagulation,through down-regulating VEGF and upregulating PEDF.

IL-4, IL-6, IL-10, IL-17A and vascular endothelial growth factor in the vitreous of patients with proliferative diabetic retinopathy

In current article, results of the determination of the concentrations of vascular endothelial growth factor (VEGF), and some interleukins (IL-4, IL-6, IL-10, IL-17А) in the vitreous of patients with proliferative diabetic retinopathy are presented. We have found that in the mechanism of development of diabetic retinopathy, significant role plays an activation of local inflammation process and vascular proliferation. This is evidenced by a significant increase in the vitreous concentration of IL-4, IL-6, IL-10, IL-17A and vascular endothelial growth factor. Identified correlations between VEGF and IL-17A, between VEGF and IL-4, and between IL-17A and IL-4 show the relationship of inflammation and proliferation processes in the pathogenesis of diabetic retinopathy.

Vascular endothelial growth factor trap-eye(Aflibercept) for the management of diabetic macular edema

Diabetic retinopathy(DR)is the most common cause of visual loss among working age individuals.Diabetic macular edema(DME)is an important complication of DR that affects around one third of the patients with DR.Several treatments have been approved for DME ranging from blood pressure and glycemic control to photocoagulation and more recently the use of vascular endothelial growth factor(VEGF)antagonists.The index review discusses aflibercept(EYLEA-Regeneron Pharmaceuticals,Inc.,Tarrytown,New York,NY,and Bayer Healthcare Pharmaceuticals,Berlin,Germany)in the context of other VEGF antagonists currently available for the treatment of DME.A systematic search of literature was conducted on PubMed,Scopus,and Google Scholar with no limitation on language or year of publication.Pre-clinical studies of aflibercept have shown a higher affinity of this molecule for vascular endothelial growth factor A(VEGF-A)along with a longer duration of action as compared to other VEGF antagonists.Recent clinical trials have shown visual outcome results for aflibercept to be similarly favorable as compared to other available agents with the added benefit of fewer required injections and less frequent monitoring.Aflibercept presents a potential exciting new addition to the armamentarium of current VEGF antagonists available for the treatment of DME and other retinal vascular diseases.However,further studies are indicated to confirm the role,safety,and efficacy of aflibercept for DME.

Effect of periocular injection of celecoxib and propranolol on ocular level of vascular endothelial growth factor in a diabetic mouse model

AIM： To investigate the effects of periocular injection of propranolol and celecoxib on ocular levels of vascular endothelial growth factor （VEGF） in a diabetic mouse model. METHODS： Forty 4-6wk BALB-C male mice weighing 20-25 g were used. The study groups included： nondiabetic control （group 1）, diabetic control （group 2）, diabetic propranolol （group 3）, and diabetic celecoxib （group 4）. After induction of type 1 diabetes by streptozotocin, propranolol （10 μg） and celecoxib （200 μg dissolved in carboxymethylcellulose 0.5%） were injected periocularly. The ocular level of VEGF was measured in all the study groups using enzyme-linked immuno sorbent assay （ELISA） method. RESULTS： Ocular VEGF level was significantly increased （1.25 fold） in the diabetic control group when compared to the non-diabetic group one week after induction with streptozotocin （P=0.002）. Both periocular propranolol and celecoxib significantly reduced ocular VEGF levels （P=0.047 and P〈0.001, respectively）. The effect was more pronounced with celecoxib, CONCLUSION： The periocular administration of propranolol and celecoxib can significantly reduce ocular VEGF levels in a diabetic mouse model.

Matrix metalloproteinase-9 and vascular endothelial growth factor expression change in experimental retinal neovascularization

AIM： To investigate the signal transduction mechanism of matrix metalloproteinase-9 （MMP-9） mediatedvascular endothelial growth factor （VEGF） expression and retinal neovascularization （RNV） in oxygen-induced retinopathy （OIR） model. METHODS： C57BL/6J mice were divided into four groups： control group, OIR group, OIR control group （phosphatebuffered saline by intravitreal injection） and treated group [tissue inhibitor of matrix metalloproteinase-1 （TIMP-1） by intravitreal injection]. OIR model was established in C57BIJ6J mice exposed to 75% ＋2% oxygen for 5d. mRNA level and protein expression of MMP-9, TIMP-1 and VEGF were measured by real-time polymerase chain reaction and Western blotting, and located by immunohistochemistry. RESULTS： Levels of MMP-9 and VEGF in retina were significantly increased in animals with OIR and OIR control group. Levels of TIMP -1 in retina was significantly reduced in animals with OIR and OIR control group. Furthermore, a significant correlation was found between MMP-9 and VEGF. Intravitreal injection of TIMP- 1 significantly reduced MMP-9 and VEGF expression of the OIR mouse model （all P〈0.05）. CONCLUSION： These results demonstrate that MMP- 9-mediated up-regulation of VEGF promotes RNV in retinopathy of prematurity （ROP）. TIMP-1 may be a potential target for the prevention and treatment of ROP.

Elevated Vascular Endothelial Growth Factor Levels in the Vitreous of Patients With Proliferative Diabetic Retinopathy

Objective: To detect the levels of vascular endothelial growth factor (VEGF) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate the possible role of VEGF in the development of neovascularization in PDR. Methods ; Undiluted vitreous samples and fasting venous blood samples were obtained from 27 patients with PDR and 14 subjects with idiopathic macular hole who underwent pars plana vitrectomy. The concentration of VEGF was determined by quantitative enzyme - linked immunosorbent assay (ELISA).Results: The level of vitreous VEGF in patients with PDR (median 0. 41ng/ml, range 0. 09- 11. 56ng/ml) was significantly elevated when compared with that in control subjects (median 0.017ng/ml, range 0.008-0.04ng/ml)(P<0. 001). The median of PDR patients' serum VEGF concentration was 0.19ng/ml (0. 090. 46ng/ ml) which was far lower than vitreous VEGF concentration (P<0. 05). Vitreous VEGF concentration was higher in PDR patients with retinal detachment than that in patient

Evaluation of Serum and Aqueous Humor Vascular Endothelial Growth Factor in Neovascular Glaucoma

Purpose: The study aimed to evaluate and correlate between the levels of vascular endothelial growth factor (VEGF) in serum and aqueous humor in cases of neovascular glaucoma (NVG) to stand up on if it can be used as a marker for early detection of such cases. Methods: This observational case control study included 60 eyes, divided into 3 groups, group A of 30 eyes presented by cataract of different causes (not diabetic patients and no signs of NVG) as a control group and group B of 30 eyes with NVG due to different causes, group C of the same eyes in group B but after one month of treatment by intravitreal bevacizumab and laser treatment by pan retinal photocoagulation (PRP). Serum VEGF was estimated in all groups, also aqueous humor VEGF was estimated in group A and B only. In addition glycosylated hemoglobin (HbA1c) was estimated in group B;statistical analysis of the results was performed. Results: The study revealed that the commonest cause of NVG was proliferative diabetic retinopathy (PDR) in 26 cases (86.7%), HbA1c in group B revealed mean value 7.68% ± 2.75%. Serum VEFG level in the group B of cases of NVG was significantly higher than the control group A (P 0.05). Conclusions: VEGF is considered a good marker for the NVG either in serum or aqueous humor, laser treatment and the use of anti-VEGF are crucial treatment for such cases, and also glycemic control is a must for regulation of the vascular process in diabetic patients for prevention of such ocular neovascularization.

Inhibitory effect of maspinon neovascularization in diabetic retinopathy

BACKGROUND Diabetic retinopathy(DR)is a serious and potentially blinding complication of diabetes mellitus.Retinal neovascularization is one of the main pathological features of proliferative DR,and inhibiting retinal neovascularization is a research focus.AIM The aim was to evaluate the effect of intravitreal injection of recombinant human maspin on neovascularization in DR.METHODS An oxygen-induced retinopathy(OIR)mouse model was used to simulate neovascularization in DR.New born C57BL/6J mice were randomly divided to a normal control group,a maspin injection OIR group,and an OIR group.The mice in the maspin injection OIR group were injected with recombinant human maspin in the bilateral vitreous cavity on postnatal day P12,and those in the OIR group were injected with sterile phosphate buffered saline.The protein expression of vascular endothelial growth factor(VEGF)and hypoxia-inducible factor 1-alpha(HIF-1α)in the retina was measured by western blotting,and the mRNA expression of VEGF and HIF-1αwas measured by real-time polymerase chain reaction.The vascular cell nuclei that broke through the inner limiting membrane(ILM)were counted in haematoxylin-eosin stained retinal sections.RESULTS It was found that the number of vascular cell nuclei breaking through the ILM was 31.8±8.75 in the OIR group,which was significantly more than that in the normal control group(P<0.001).The number of vascular cell nuclei breaking through the ILM was 6.19±2.91 in the maspin injection OIR group,which was significantly less than that in OIR group(P<0.01).The relative protein and mRNA expression of VEGF and HIF-1αwas significantly lower in the retinas in the maspin injection OIR group than in those in the OIR group(P<0.01).CONCLUSION Maspin inhibited neovascularization in DR by modulating the HIF-1α/VEGF pathway,which provides a potential and effective strategy for the treatment of DR.

Research progress on the role of connective tissue growth factor in fibrosis of diabetic retinopathy

Diabetic retinopathy（DR） is one of the most important types of diabetic microangiopathy, which is a specific change of fundus lesions and is one of the most serious complications of diabetes. When DR develops to proliferative DR, the main factors of decreasing vision, and even blindness, include retinal detachment and vitreous hemorrhage caused by contraction of blood vessels by fiber membrane. Recent studies reported that the formation of fiber vascular membrane is closely related to retinal fibrosis. The connective tissue growth factor（CTGF） is a cytokine that is closely related to DR fibrosis. However, its mechanism is poorly understood. This paper summarizes the recent studies about CTGF on DR fibrosis for a comprehensive understanding of the role and mechanism of CTGF in PDR.

Effects of long non-coding RNA myocardial infarction-associated transcript on retinal neovascularization in a newborn mouse model of oxygen-induced retinopathy

Whether long non-coding RNA myocardial infarction-associated transcript is involved in oxygen-induced retinopathy remains poorly understood. To validate this hypothesis, we established a newborn mouse model of oxygen-induced retinopathy by feeding in an oxygen concentration of 75 ± 2% from postnatal day 8 to postnatal day 12, followed by in normal air. On postnatal day 11, the mice were injected with the myocardial infarction-associated transcript siRNA plasmid via the vitreous cavity to knockdown long non-coding RNA myocardial infarction-associated transcript. Myocardial infarction-associated transcript siRNA transcription significantly inhibited myocardial infarctionassociated transcript mRNA expression, reduced the phosphatidylinosital-3-kinase, phosphorylated Akt and vascular endothelial growth factor immunopositivities, protein and mRNA expression, and alleviated the pathological damage to the retina of oxygen-induced retinopathy mouse models. These findings suggest that myocardial infarction-associated transcript is likely involved in the retinal neovascularization in retinopathy of prematurity and that inhibition of myocardial infarction-associated transcript can downregulate phosphatidylinosital-3-kinase, phosphorylated Akt and vascular endothelial growth factor expression levels and inhibit neovascularization. This study was approved by the Animal Ethics Committee of Shengjing Hospital of China Medical University, China(approval No. 2016 PS074 K) on February 25, 2016.

Association between endoplasmic reticulum stress and risk factors of diabetic retinopathy

Diabetic retinopathy（DR）is one of the most common and challenging ocular complications of diabetes mellitus.As a chronic,progressive ocular disease that poses a serious threat to vision,DR has gradually become a leading cause of blindness worldwide.Emerging evidence points to an important role of endoplasmic reticulum（ER）stress in not only maintaining the steady-state equilibrium in the body,but also in intracellular synthesis,protein folding,and other essential functions.Recent studies have demonstrated clear associations between ER stressrelated physiological functions and the pathogenesis of DR.When cells are stimulated by external stimuli,UPR pathway is activated firstly to protect it.However,long-term harmful factors can induce ER stress.which interferes with the physiological metabolism of retinal cells and participates in the occurrence of DR via the ATF6 pathway,PERK pathway and IRE1 pathway.At present,ER stress blocker is expected to become a new anti-DR therapy.Thus,understanding the relationship between ER stress and DR will help to develop new effective preventative treatments.In this review,we summarize the risk factors of DR pathogenesis induced by ER stress toward revealing potentially new therapeutic targets.

Correlation of serum ICAM-1 and VEGF levels with microvascular injury in patients with senile diabetic retinopathy

Objective:To study the correlation between serum vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM) -1 level and microvascular injury in elderly diabetic retinopathy, and provide reference for clinical diagnosis and treatment.Methods:A total of 268 diabetic patients in our hospital in October 2015 -2017 year in October, on the basis of fundus fluorescein angiography and fundus examination were divided into proliferative diabetic retinopathy group (PDR), background diabetic retinopathy group (BDR) and diabetic retinopathy group (NDR), and 100 healthy at the same time to participate in the examination of our hospital as the control group. The changes of ICAM-1, VEGF and nitric oxide (NO), von Willebrand factor (vWF), endothelin-1 (ET-1) and thrombomodulin (TM) and other vascular endothelial function indexes in four groups were compared.Results:NDR group, BDR group, PDR group, ICAM-1, VEGF, NO and vWF (except NDR group), four ET-1 TM and vascular endothelial function indexes were significantly higher than the control group, while the difference between NDR vWF group was not statistical significant;differences in ICAM-1, VEGF and NO, vWF, ET-1 and TM four vascular endothelial function index among NDR group, BDR group and PDR group were statistically significant. Compared with the two groups, four vascular endothelial function indexes of ICAM-1, VEGF and NO, vWF, ET-1 and TM in retinopathy group were significantly higher than those in control group. Conclusions:There is correlation between VEGF, ICAM-1 level and microvascular injury in senile diabetic retinopathy patients. The late progression of the disease is, the higher VEGF, ICAM-1, NO, vWF, ET-1 and TM of vascular endothelial damage indexes are.It can reflect the microcirculation the extent of injury and blood rheology, and change of coagulation mechanism. It is worthy for clinical reference.

Vascular endothelial growth factor concentration in vitreous humor of patients with severe proliferative diabetic retinopathy after intravitreal injection of conbercept as an adjunctive therapy for vitrectomy

Background:Proliferative diabetic retinopathy(PDR)is a progressive stage of diabetic retinopathy featured by the formation of neovascular and proliferative membrane.Vascular endothelial growth factor(VEGF)acts as a pivot factor in the development of neovascularization.This study was to investigate the changes of intravitreal VEGF concentrations of severe PDR after intravitreal injection of conbercept(IVC)and its potential advantages to the following vitrectomy.Methods:This was a prospective,interventional,randomized controlled study.Sixty eyes(60 patients)with severe PDR and 20 eyes from 20 patients with rhegmatogenous retinal detachment complicated with proliferative vitreoretinopathy were enrolled in this study.PDR eyes were randomly assigned to three groups by sortation randomization method with 20 eyes in each based on the interval of preoperative IVC(group A:7 days,group B:14 days,group C:non-IVC).Another 20 eyes without diabetes were enrolled as the non-diabetic control group(group D),receiving PPV directly.Vitreous specimens of all 80 patients were collected and evaluated afterwards.The intravitreal VEGF concentration of the four groups,and the total surgical time and the intraoperative bleeding rate of the PDR groups were recorded.Results:The mean intravitreal VEGF concentrations of groups A-D were 66.6±43.3,93.1±52.3,161.4±106.1 and 1.8±1.2 pg/mL,respectively.It increased significantly in PDR patients(groups A,B and C)(P=0.002,<0.001,and<0.001,respectively).PDR patients with preoperative IVC(groups A and B)presented significantly lower VEGF concentrations(P<0.001 and 0.001),intraoperative bleeding rates(P=0.004)and total surgical time(P<0.001,P=0.003)compared with group C.No statistical differences were presented between groups A and B on the three parameters.Conclusion:Seven days and 14 days of preoperative IVC are equally efficient and safe for the vitrectomy of severe PDR patients through decreasing vitreous VEGF concentrations,intraoperative bleeding rate and total surgical times.

Changes in vitreous VEGF, bFGF and fibrosis in proliferative diabetic retinopathy after intravitreal bevacizumab

AIMTo evaluate the relationship between intravitreal bevacizumab (IVB) treatment and the levels of vitreous vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and vitreous-retina surface fibrosis in patients with proliferative diabetic retinopathy (PDR).METHODSThis study was a prospective, open-label, controlled, randomized clinical trial. Sixty-eight eyes of PDR patients (n=53) and macular hole patients (n=15) were enrolled in this study. Thirty-four eyes of the PDR patients received IVB before vitrectomy. Twenty-three of the 34 PDR patients received IVB treatment 5d before vitrectomy (subgroup a), and 11 of the 34 PDR patients received IVB treatment greater than 2wk prior to vitrectomy (subgroup b). Nineteen of the PDR patients did not receive IVB treatment at any time prior to vitrectomy. The levels of bFGF and VEGF in vitreous samples were measured using enzyme-linked immunosorbent assay (ELISA) and the degree of vitreoretinal fibrosis was characterized using clinical data and data obtained intra-operatively.RESULTSIn PDR patients, VEGF and bFGF levels were significantly increased compared to non-PDR (control) subject's eyes (P&#x0003c;0.01). In PDR patients, vitreous VEGF levels were significantly decreased following IVB treatment compared to PDR patients that did not receive IVB treatment (P&#x0003c;0.01). The degree of vitreoretinal fibrosis was significantly increased in subgroup b compared to subgroup a(P&#x0003c;0.05) and to patients that did not receive IVB (P&#x0003c;0.05). Vitreous bFGF levels were significantly greater in subgroup b than subgroup a (P&#x0003c;0.01) or in patients who did not receive IVB treatment (P&#x0003c;0.05). A Spearman's rank correlation test indicated that higher levels of vitreous bFGF, but not VEGF, correlated with the degree of vitreoretinal fibrosis.CONCLUSIONWe found that bFGF levels increase in PDR patient's vitreous after IVB treatment longer than two weeks prior to vitrectomy and correlated with the degree of fibrosis after IVB treatment. These findings suggest vitreous fibrosis is increased in PDR patients after IVB treatment may be due to increased levels of bFGF.

Evaluation of VEGF gene polymorphisms and proliferative diabetic retinopathy in Mexican population

AIM： To assess if the included vascular endothelial growth factor （VEGF） polymorphisms rs3025035, rs3025021 and rs2010963 are associated to proliferative retinopathy in a Mexican population with type 2 diabetes mellitus （T2DM）. METHODS： A case-control study was conducted in adult individuals with T2DM associated to proliferative retinopathy or non-proliferative retinopathy from Oct. 2014 to Jun. 2015 from the Retina Department of the Asociation to Prevent Blindness in Mexico. The selected patients were adults with a diagnosis of T2DM ≥5y. All subjects had a comprehensive ocular examination and the classification of the retinopathy severity was made considering the Early Treatment Diabetic Retinopathy Study （ETDRS） standardization protocols. Genomic DNA was extracted from whole fresh blood. All samples were genotyped by qPCR for selected VEGF polymorphisms. Hardy-Weinberg equilibrium was calculated by comparing Chi-square values between the expected and the observed values for genotype counts.RESULTS： In total 142 individuals were enrolled, 71 individuals with T2DM and associated proliferative retinopathy and 71 individuals with non-proliferative retinopathy. One-sided Fisher’s exact test was performed for rs3025021 [OR （95% CI）=0.44（0.08-2.2）; P=0.25] and rs2010963 [OR （95% CI）=0.63（0.25-1.6）; P=0.23]. The minor allelic frequencies obtained were 26% for rs3025021, 10% for rs3025035 and 61% for rs2010963. The pairwise linkage disequilibrium between the three SNP was assessed, and was as follows： rs3025021 vs rs3025035： D’=1.0, r2=0.1043, P≤0.0001; rs3025021 vs rs2010963： D’=0.442, r2=0.0446, P=0.149; rs3025035 vs rs2010963： D’=0.505, r2=0.0214, P=0.142.CONCLUSION： This is the first analysis involving VEGF polymorphisms and proliferative diabetic retinopathy in a Mexican population. A major finding of the present study is that none of the polymorphisms studied was significantly associated with proliferative retinopathy. Based on these results, we can infer that different populations have different associations for the same polymorphisms.

Elevation of serum apelin-13 associated with proliferative diabetic retinopathy in type 2 diabetic patients

AIM: To compare apelin-13, a ligand of G-proteincoupled receptor which has been shown to be involved in retinal angiogenesis, and vascular endothelial growth factor(VEGF) serum levels in type 2 diabetes mellitus(T2DM) with or without retinopathy, and to investigate the relationship between the serum concentration of apelin-13 and diabetes retinopathy.METHODS: Sixty-nine patients with T2 DM were enrolled.Of the 69 patients, 16 had proliferative diabetic retinopathy(PDR group), 23 had non-PDR(NPDR group)and 30 had no retinopathy(T2DM group). Subjects’ information, including demographics, medical history,and use of medications were recorded. Their serum samples were collected for measuring the levels of C-reactive protein(CRP), serum lipid and glycosylated hemoglobin. Apelin-13 and VEGF serum levels were measured by enzyme-linked immunosorbent assay.Kruskal-Wallis test and one-way ANOVA were used to compare the differences among these groups. Chi-square test was used to assess categorical variables.Correlations between variables were investigated by Spearman rho correlation test and stepwise regression analysis. All statistical analyses were performed through SPSS 17.0 software.RESULTS: Sex, age, body mass index(BMI), blood pressure, CRP, hemoglobin A1c(Hb A1c) have no significantly difference in the three groups. Serum level of apelin-13 was significantly elevated in PDR group as compared with T2 DM group(P =0.041). Differences of VEGF serum concentration in the three groups were statistically significant(P =0.007, P =0.007 and P 【0.001,respectively). Spearman rho correlation test showed that serum apelin-13 was positively correlated with BMI,serum triglycerides, VEGF, but not with age, duration of diabetes, blood pressure, CRP, Hb A1 c and total-cholesterol. Stepwise regression analysis showed that BMI also significantly associated with serum apelin-13(P =0.002), while VEGF and serum triglycerides were irrelevant. CONCLUSION: This study elucidated a positive association of apelin-13 serum level with PDR, but not with VEGF. Apelin-13 may influence the promotion of PDR but unrelated with VEGF.