Pigment Epithelium-derived Growth Factor Research Articles

AUROLAB AQUEOUS DRAINAGE IMPLANT IN YOUNG ADULT WITH NEOVASCULAR GLAUCOMA AND TUBERCULOSIS HISTORY: A CASE REPORT

Introduction: Neovascular glaucoma (NVG) is historically known as rubeotic glaucoma, from “rubeosis iridis” that refers to the iris neovascularization. One of several causes that lead to rubeosis iridis is changes in Pigment Epithelium-Derived Growth Factor (PEDF) that may be caused by Mycobacterium tuberculosis. The influence of NVG may cause intraocular pressure (IOP) to rise rapidly. It can be decreased by Aurolab Aqueous Drainage Implant (AADI). Case Report: A 34-year-old male complained of left eye pain and sudden decreased vision for the past 2 months. He had been diagnosed with tuberculosis since 8 months ago. The patient’s blood pressure, blood sugar, cholesterol, and triglycerides were within normal limit. Diabetes Mellitus (-). Human Immunodeficiency Virus (-). Visual acuity of left eye was hand movement. The pupil was dilated and non-reactive, anterior chamber depth is shallow, and rubeosis iridis (+). IOP is 60 mmHg. Medical management was failed to decrease the IOP. Funduscopy image showed cup-disc ratio was 0,7. Ganglion cell complex parameters showed 80,91. On the next day after AADI implantation surgery, the patient’s left eye IOP was reduced to 10 mmHg. On the 14th day post operative visual acuity was 2 meter counting finger. The anterior segment of the conjunctiva bulbi was hyperemic and conjunctival injection was reduced. The camera oculi anterior showed remainder of the implant. In the iris, rubeosis iridis disappeared, pupil was dilated, IOP was increased to 12 mmHg Discussion: Neovascular glaucoma was caused by the growth of the fibrovascular membrane on the surface of the iris and the anterior chamber angle. The three most common causes of neovascular glaucoma were diabetes mellitus, central retinal vein occlusion, and carotid artery occlusion. Conclusion:AADI is a safe and effective option for patients with neovascular glaucoma following tuberculosis.

Mechanism of circular RNA-mediated regulation of L-DOPA to improve wet age-related macular degeneration

This study aimed to investigate the effect and mechanism of levodopa (L-DOPA) in the treatment of age-related macular degeneration (AMD). A wet AMD cell model was created via CoCl2 treatment of ARPE-19 cells. The cytoprotective effects of L-DOPA in the model were determined using CCK-8, flow cytometry, TUNEL, qPCR, and ELISA assays. Subsequently, circRNA sequencing and bioinformatics analysis were used to screen differentially expressed circRNAs, which were overexpressed in ARPE-19 cells, to explore their role in wet AMD. The findings revealed that 200 μM CoCl2 treatment inhibited the cell viability and the production of tyrosinase, melanin, and pigment epithelium-derived growth factor but promoted apoptosis and the expression of vascular endothelial growth factor in ARPE-19 cells. Moreover, 20 μM L-DOPA exerted the best therapeutic effect on the model. qPCR showed that Hsa_circ_0018401 (circ-SGMS1) was significantly differentially expressed in each experimental group, which was consistent with the sequencing results. The overexpression of circ-SGMS1 in ARPE-19 cells reversed the effects of CoCl2. Fluorescence in situ hybridization showed that circ-SGMS1 was expressed more in the nucleus than in the cytoplasm. qPCR assays indicated that circ-SGMS1 overexpression did not have a significant effect on the expressions of VEGFA and KDR but significantly reduced the expressions of HIF-1a and THBS1. Circ-SGMS1 is of immense significance in the AMD treatment mechanism of L-DOPA. Overexpression of circ-SGMS1 may alleviate wet AMD by inhibiting HIF-1a and THBS1 expression.

Diabetic retinopathy: neurovascular disease requiring neuroprotective and regenerative therapies.

Diabetic retinopathy: neurovascular disease requiring neuroprotective and regenerative therapies.

Soy Protein Nanofiber Scaffolds for Uniform Maturation of Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium.

Retinal pigment epithelium (RPE) differentiated from human induced pluripotent stem cells, called induced retinal pigment epithelium (iRPE), is being explored as a cell-based therapy for the treatment of retinal degenerative diseases, especially age-related macular degeneration. The success of RPE implantation is linked to the use of biomimetic scaffolds that simulate Bruch's membrane and promote RPE maturation and integration as a functional tissue. Due to difficulties associated with animal protein-derived scaffolds, including sterility and pro-inflammatory responses, current practices favor the use of synthetic polymers, such as polycaprolactone (PCL), for generating nanofibrous scaffolds. In this study, we tested the hypothesis that plant protein-derived fibrous scaffolds can provide favorable conditions permissive for the maturation of RPE tissue sheets in vitro. Our natural, soy protein-derived nanofibrous scaffolds exhibited a J-shaped stress-strain curve that more closely resembled the mechanical properties of native tissues than PCL with significantly higher hydrophilicity of the natural scaffolds, favoring in vivo implantation. We then demonstrate that iRPE sheets growing on these soy protein scaffolds are equivalent to iRPE monolayers cultured on synthetic PCL nanofibrous scaffolds. Immunohistochemistry demonstrated RPE-like morphology and functionality with appropriate localization of RPE markers RPE65, PMEL17, Ezrin, and ZO1 and with anticipated histotypic polarization of vascular endothelial growth factor and pigment epithelium-derived growth factor as indicated by enzyme-linked immunosorbent assay. Scanning electron microscopy revealed dense microvilli on the cell surface and homogeneous tight junctional contacts between the cells. Finally, comparative transcriptome analysis in conjunction with principal component analysis demonstrated that iRPE on nanofibrous scaffolds, either natural or synthetic, matured more consistently than on nonfibrous substrates. Taken together, our studies suggest that the maturation of cultured iRPE sheets for subsequent clinical applications might benefit from the use of nanofibrous scaffolds generated from natural proteins. Impact statement Induced retinal pigment epithelium (iRPE) from patient-derived induced pluripotent stem cells (iPSCs) may yield powerful treatments of retinal diseases, including age-related macular degeneration. Recent studies, including early human clinical trials, demonstrate the importance of selecting appropriate biomaterial scaffolds to support tissue-engineered iRPE sheets during implantation. Electrospun scaffolds show particular promise due to their similarity to the structure of the native Bruch's membrane. In this study, we describe the use of electroprocessed nanofibrous soy protein scaffolds to generate polarized sheets of human iPSC-derived iRPE sheets. Our evaluation, including RNA-seq transcriptomics, indicates that these scaffolds are viable alternatives to scaffolds electrospun from synthetic polymers.

Fibrocyte-Like Cells from Intrauterine Growth Restriction Placentas Have a Reduced Ability to Stimulate Angiogenesis

Intrauterine growth restriction (IUGR) is a common complication of pregnancy whereby the fetus fails to achieve its genetic growth potential. Malformation of the placental vasculature is observed in IUGR and may be due to the development of the placenta in a chronically hypoxic environment. Recently, we identified that the predominant stromal cells in the angiogenic zones of the placenta are fibrocyte-like cells. The conditioned medium from fibrocyte-like cells (FcCM) has been shown to stimulate angiogenesis invitro. Thus, we hypothesized that FcCM from IUGR cells would have a reduced ability to stimulate angiogenesis and that chronic hypoxia would decrease the ability of both normal and IUGR fibrocyte-like cells to stimulate angiogenesis. IUGR FcCM had a reduced ability to stimulate endothelial tubule-like structure formation and an increased ability to stimulate endothelial migration compared with normal FcCM. However, normal and IUGR FcCM produced in chronic hypoxia did not alter endothelial proliferation, migration, or tubule-like structure formation. IUGR FcCM was found to have reduced levels of the pro-angiogenic cytokine IL-8 and increased levels of the anti-angiogenic factors activin-A and pigment epithelium-derived growth factor. Thus, alterations in the ability of IUGR fibrocyte-like cells to stimulate angiogenesis may contribute to the development of vascular malformation in IUGR, but invitro these changes cannot be attributed to a chronically hypoxic environment.

Cytokine concentration in aqueous humour of eyes with exudative age‐related macular degeneration

To measure the concentration of cytokines in the aqueous humour of eyes with exudative age-related macular degeneration (AMD). The clinical interventional study included a study group of 18 patients with exudative AMD and a control group of 20 patients undergoing routine cataract surgery. Age did not vary significantly (p = 0.36) between study group (80.8 ± 6.4 years) and control group (77.0 ± 9.9 years), nor did gender (p = 0.75). During the interventions, aqueous humour samples were obtained, in which the concentration of cytokines was measured using a solid-phase chemiluminescence immunoassay. Macular thickness was measured by optical coherence tomography (OCT). In the study group as compared to the control group, significantly higher concentrations were measured for epithelial growth factor (EGF) (p = 0.017), human growth factor (HGF) (p= 0.048), intercellular adhesion molecule-1 (ICAM1) (p = 0.028), interleukin 12p40 (IL12p40) (p = 0.009), interleukin 1a2 (IL1a2) (p = 0.01), interleukin 3 (IL3) (p = 0.02), interleukin 6 (IL6) (p = 0.006), interleukin 8 (IL8) (p = 0.02), monocyte chemoattractant protein-1 (MCP-1) (p = 0.048), monokine induced by interferon gamma (MIG) (p = 0.016), matrix metalloproteinase 9 (MMP9) (p = 0.004) and plasminogen activator inhibitor 1 (PAI1) (p = 0.006). Macular thickness was significantly associated with the concentrations of EGF (p = 0.001), HGF (p = 0.02), ICAM1 (p = 0.001), interleukin 12p40 (p = 0.006), IL 1a2 (p = 0.002), MIG (p = 0.001), MMP9 (p < 0.001) and PAI1 (p = 0.01). Interleukin 6 and MCP-1 showed significant associations with the height of retinal pigment epithelium detachment. Numerous cytokines are associated with the presence and the amount of exudative AMD.

Pigment epithelium-derived growth factor: modulating adult neural stem cell self-renewal

The vascular niche-derived factor PEDF enhances Notch signaling in adult neural stem cells via an unexpected mechanism involving nuclear export of a transcriptional repressor, to promote both proliferation and multipotentiality.

Current and emerging therapies for the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of vision loss in the industrialized world. In the last few decades, the mainstay of treatment for choroidal neovascularization (CNV) due to AMD has been thermal laser photocoagulation. In the last decade, photodynamic therapy with verteporfin extended treatment for more patients. While both of these treatments have prevented further vision loss in a subset of patients, improvement in visual acuity is rare. Anti-vascular endothelial growth factor A (VEGF) therapy has revolutionized the treatment of AMD-related CNV. Pegaptanib, an anti-VEGF aptamer prevents vision loss in CNV, although the performance is similar to that of photodynamic therapy. Ranibizumab, an antibody fragment and bevacizumab, a full-length humanized monoclonal antibody against VEGF have both shown promising results with improvements in visual acuity with either agent. VEGF trap, a modified soluble VEGF receptor analogue, binds VEGF more tightly than all other anti-VEGF agents and has also shown promising results in early trials. Other treatment strategies to decrease the effect of VEGF have used small interfering ribonucleic acid (RNA) to inhibit VEGF production and VEGF receptor production. Steroids, including anecortave acetate in the treatment and prevention of CNV, have shown promise in controlled trials. Receptor tyrosine kinase inhibitors, such as vatalanib, inhibit downstream effects of VEGF, and have been effective in the treatment of CNV in early studies. Squalamine lactate inhibits plasma membrane ion channels with downstream effects on VEGF, and has shown promising results with systemic administration. Other growth factors, including pigment epithelium-derived growth factor that has been administered via an adenoviral vector has shown promising initial results. In some patients ciliary neurotrophic factor is currently being studied for the inhibition of progression of geographic atrophy. Combination therapy has been investigated, and may prove to be more effective in the management of AMD-associated CNV. Ongoing and future studies will be crucial for optimizing the treatment of patients with AMD.

The Constitutively Active Orphan G-protein-coupled Receptor GPR39 Protects from Cell Death by Increasing Secretion of Pigment Epithelium-derived Growth Factor

GPR39 is a constitutively active orphan G-protein-coupled receptor capable of increasing serum response element-mediated transcription. We found GPR39 to be up-regulated in a hippocampal cell line resistant against diverse stimulators of cell death and show that its overexpression protects against oxidative and endoplasmic reticulum stress, as well as against direct activation of the caspase cascade by Bax overexpression. In contrast, silencing GPR39 rendered cells more susceptible to cell death. An array analysis of transcripts induced by GPR39 revealed up-regulation of RGS16 (inhibitor of G-protein signaling 16), which suggested coupling to Galpha(13) and induction of serum response element-mediated transcription by the small GTPase RhoA. In line with this, co-expression of GPR39 with RGS16, dominant-negative RhoA, or serum response factor abolished cell protection, whereas overexpression of the serum response factor protected from cell death. Further downstream the signaling cascade, GPR39 overexpression leads to increased secretion of the cytoprotective pigment epithelium-derived growth factor (PEDF). Medium conditioned by cells overexpressing GPR39 contained 4-fold more PEDF, and when stripped off it lost most but not all of its protective properties. We conclude that GPR39 is a novel inhibitor of cell death, which might represent a therapeutic target with implications for processes involving apoptosis and endoplasmic reticulum stress like cancer, ischemia/reperfusion injury, and neurodegenerative disease.

Proangiogenic properties of 4‐hydroxy phenylretinamide (4‐HPR) in experimental neovascularization and study of its mechanisms

Purpose: We investigated the effect of 4‐HPR on a murine model of laser‐induced choroidal neovascularization (CNV). The effects of 4‐HPR on apoptosis and angiogenic factors was studied in cultured human retinal pigment epithelial cells (RPE).Methods: Retina of C57BL/6 mice was exposed to laser irradiation. 4‐HPR (0.2 mg or 1 mg) or vehicle was injected intraperitoneally daily for 14 days post‐laser. Cultured RPE were treated with 4‐HPR and apoptosis and regulation of growth factors was determined.Results: Mice treated with 4‐HPR exhibited an increase in vascular leakage, CNV lesion size, and lesion volume. A dose‐dependent decrease in lesion‐associated RPE cell number and increase in subretinal fluid was found. 4‐HPR increased RPE cytotoxicity, active caspase‐3 and apoptosis. Upregulation of vascular endothelial growth factor (VEGF)‐A, and ‐C and angiopoietin‐1 genes and increased VEGF secretion were observed with 4‐HPR (p&lt;0.01 vs. untreated), while pigment epithelium derived growth factor and thrombospondin‐1 were significantly (p&lt;0.05) downregulated.Conclusions: Administration of 4‐HPR to mice resulted in increased CNV. The increased neovascularization with 4‐HPR was accompanied by upregulation of proangiogenic and downregulation of antiangiogenic factors. Loss of RPE around the laser lesions may arise from 4‐HPR‐induced cell death. Supported by Arnold and Mabel Beckman Foundation.

N-(4-hydroxyphenyl) Retinamide Augments Laser-Induced Choroidal Neovascularization in Mice

To evaluate the effect of N-4-hydroxyphenyl retinamide (4-HPR) on experimental laser-induced choroidal neovascularization (CNV) and on the expression and secretion of relevant growth factors by cultured human retinal pigment epithelial (RPE) cells. CNV was induced by laser photocoagulation in C57BL/6 mice. 4-HPR (0.2 or 1 mg) or vehicle, was injected intraperitoneally twice daily for 14 days. Plasma and tissue levels of 4-HPR were measured by HPLC. CNV was evaluated by fluorescein angiography, histology, and quantitative confocal analysis of isolectin B4 histochemistry on days 7 and 14. Induction of apoptosis and expression and secretion of growth factors was studied in 4-HPR-treated RPE cultures. Mice treated with 4-HPR exhibited time- and dose-dependent increases in plasma and tissue 4-HPR levels. CNV lesions showed increased volume with increased vascular leakage and contained fewer lesion-associated RPE in treated versus untreated mice. Treatment of nonpolarized RPE cultures with 4-HPR in the presence of serum resulted in RPE apoptosis; however, apoptosis was minimal in similarly treated highly polarized RPE. Treatment of RPE cells with 4-HPR resulted in the upregulation of VEGF-A and -C (P < 0.05) and Ang-1 (P < 0.01) mRNA and increased secretion of VEGF-A and -C (P < 0.05), whereas pigment epithelium-derived growth factor (PEDF) and thrombospondin (TSP)-1 mRNA expression and secretion were downregulated (P < 0.05). 4-HPR increases lesion size and leakage in laser-induced CNV and is associated with the upregulation of key proangiogenic factors and the downregulation of antiangiogenic factors. Consistent with the preferential loss of RPE in CNV lesions in vivo, 4-HPR induces apoptosis of nonpolarized RPE in the presence of serum.

Insulin‐like growth factors, angiopoietin‐2, and pigment epithelium–derived growth factor in the hypoxic retina

As the response of the adult retina to hypoxia is likely to differ from that already established in the neonatal animal, this study was undertaken to examine the expression patterns of insulin-like growth factor-I (IGF-I) and -II (IGF-II), angiopoietin-2 (Ang-2), and pigment epithelium-derived growth factor (PEDF) in normal and hypoxic retinas of adult rats. In the latter, the retinas were examined from 3 hr to 14 days after hypoxic exposure. The mRNA and protein expression of IGF-I, IGF-II, Ang-2, and PEDF in the retina was determined by real-time RT-PCR, Western blotting, and immunohistochemistry. The results showed up-regulated expression of IGF-I, IGF-II, and Ang-2 mRNA and protein in response to hypoxia, whereas PEDF expression was drastically reduced, suggesting that increased expression of IGF-I and IGF-II may be involved not only in neovascularization but also in neuroprotection in hypoxic conditions. The up-regulation of Ang-2, a proangiogenic factor, and the down-regulation of PEDF, an antiangiogenic factor, is indicative of an imbalance between pro- and antiangiogenic factors in the hypoxic retina that may favor neovascularization. This was supported by the increased density of rat endothelial cell antigen-1 (RECA-1) protein quantification and RECA-1-stained blood vessels in the inner retina.

Pigment epithelium-derived factor in ulcerative colitis: Possible relationship with disease activity

Objectives Pigment epithelium-derived factor (PEDF) is an endogenous most potential angiogenic inhibitor and increased expression of PEDF in intestinal mucosa specimens was shown in the course of ulcerative colitis (UC). The aim of the present study was to evaluate serum concentration of pigment epithelium-derived growth factor, a potent anti-angiogenic factor and its possible association with vascular endothelial growth factor (VEGF) levels and disease activity. Methods Concentrations of PEDF and VEGF were measured in sera of 33 patients (13 females and 20 males) with active UC. Results There was significant increase of serum PEDF (32.3 ± 2.9 vs. 20.6 ± 4.7 ng/mL, P < 0.05) as well as VEGF (326.4 ± 58.1 vs. 110.9 ± 15.7 pg/mL, P < 0.05) in UC patients compared to healthy controls. Serum PEDF showed strong, positive correlation with endoscopic score ( r = 0.622, P < 0.001), while such association was absent in respect to VEGF ( r = 0.05, P = 0.77). In contrast serum VEGF decreased in severe UC comparing to patients with a mild course of disease, however the difference was not significant (274.9 ± 64.9 vs. 360.4 ± 103.4 pg/mL, P = 0.53). Conclusions Increase in serum PEDF during UC, especially in severe forms of disease suggests its involvement in UC pathogenesis.

Targeting angiogenesis, the underlying disorder in neovascular age-related macular degeneration

Angiogenesis has a causal role in many diseases, including neovascular age-related macular degeneration (AMD). Identification of key regulators of angiogenesis, including vascular endothelial growth factor (VEGF), fibroblast growth factor 2, pigment epithelium-derived growth factor, angiopoietins and extracellular matrix molecules, has facilitated the development of novel therapeutic agents that target the underlying pathological angiogenic process. Among these, VEGF serves as a "master switch" for many ocular neovascular conditions through its promotion of endothelial cell proliferation and survival, vascular permeability and ocular inflammation.Two anti-VEGF agents are now clinically available: bevacizumab, an antibody for metastatic colorectal cancer, and pegaptanib sodium, an aptamer for neovascular AMD. Unlike bevacizumab, which binds all VEGF isoforms, pegaptanib targets only VEGF 165, the isoform responsible for pathological ocular neovascularization and thus an ideal target for treatment of AMD. Although other therapies targeting angiogenesis in AMD are in clinical development, to date, pegaptanib is the only therapy approved by the Food and Drug Administration of the United States for the treatment of all neovascular AMD and represents a valuable addition to the hitherto limited options available for patients.

Stimulation of Neovascularization by the Anti-angiogenic Factor PEDF

Examine the effect of (pigment epithelium-derived growth factor; PEDF) on laser-induced choroidal neovascularization (CNV). Adult C57Bl/6 mice were anesthetized and four laser spots were placed in each quadrant of the fundus with a krypton red laser (614 nm, 50 microm, 0.05 second, 200 mW). Animals were treated with various doses of PEDF administered with miniosmotic pumps implanted subcutaneously. Seven days after laser treatment, mice were perfused with 3% FITC high-molecular-weight dextran, the eyes enucleated, and neovascularization analyzed by confocal microscopy. Data were recorded as the volume of the neovascular complex. The effect of PEDF on endothelial cell migration, vascular tube formation in synthetic basement membrane, and VEGF production was also determined. Mice receiving a lower dose of PEDF (90 microg/mL) had significantly decreased areas of CNV. A high dose of PEDF (360 microg/mL) significantly increased CNV, whereas an intermediate dose (180 microg/mL) of PEDF had no effect. PEDF inhibited endothelial cell migration and vascular tube formation at lower doses (0.5-5 microg/mL). High doses of PEDF (25-50 microg/mL) stimulated endothelial cell migration, enhanced vascular tube formation in vitro, and stimulated VEGF production from endothelial cells. Neutralizing anti-VEGF antibody completely reversed the stimulatory effects of high doses of PEDF on CNV in vivo. PEDF demonstrates opposing effects on CNV and endothelial cell function. Whereas low doses are inhibitory, high doses can augment the development of the neovasculature. These results suggest that the effects of PEDF on neovascularization are more complex than originally believed and that caution should be exercised when PEDF therapies are considered.

Ionizing radiation induces a p53-dependent apoptotic mechanism in ARPE-19 cells.

To investigate the molecular mechanisms for cell growth inhibition or apoptosis in human retinal pigment epithelium (RPE) cells after ionizing radiation. Cell survival studies, a TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay, and a caspase-3 immunocytochemical analysis were performed on irradiated ARPE-19 cell cultures at different time periods. Transcriptional levels of p53, p21, Bax, Fas/Fas-L, vascular endothelial growth factor ( VEGF), and pigment epithelium-derived growth factor ( PEDF) were evaluated by semiquantitative reverse transcriptional polymerase chain reaction. Mutations in the p53 gene were analyzed by DNA sequencing. Protein levels of p53, VEGF, and PEDF were evaluated by Western blot. Cell viability was inversely related to radiation dose. TUNEL-positive cells were detected 6 h after radiation exposure. Caspase-3 immunocytochemical analysis revealed increased immunoreactivity in the TUNEL-positive cells. Levels of p53, p21, and Bax mRNA were greatest at the 2-h postradiation period. VEGF and PEDF mRNA and protein levels were constant. Protein levels of p53 were increased at the 4- and 6-h postradiation period. Ionizing radiation induces apoptosis in normal proliferating RPE cells through p53 activation, without affecting expression of VEGF or PEDF. We documented a molecular basis for explaining the decrease in effectiveness of radiation therapy, particularly for age-related macular degeneration. In the clinical setting, selection of appropriate radiation therapy methods and the doses for specific diseases need careful evaluation.

The role of Fas-FasL in the development and treatment of ischemic retinopathy.

Define a role for Fas-FasL in oxygen-induced retinopathy and explore the mechanism of pigment-epithelium-derived growth factor (PEDF) inhibition in this model. Seven-day-old mice C57BL/6J (B6), FasL-defective (B6-gld), or Fas-defective (B6-lpr) mice were exposed to 75% oxygen for 5 days (postnatal day [P]7-P12) and returned to room air. On day P17, vascular architecture was assessed microscopically after perfusion with FITC-dextran, and preretinal nuclei were quantified by PAS and hematoxylin staining. In some experiments, mice were treated intraperitoneally with PEDF. Vascular architecture and preretinal nuclei counts were compared with those in PBS-treated control animals. Oxygen-induced retinopathy was significantly increased in FasL-defective gld mice compared with wild-type B6 animals. This was manifested by an increase in the number of microaneurysms, neovascular tufts, and preretinal nuclei. PEDF treatment prevented retinopathy in B6, B6-gld, and B6-lpr mice. Fas-FasL interactions regulate the extent of oxygen-induced retinal neovascularization. The inhibition of neovascularization in B6 gld, and B6-lpr mice by PEDF suggests that Fas-FasL interactions are probably not the mechanism for inhibition in this model.

Pigment epithelium-derived factor is deficient in the vitreous of patients with choroidal neovascularization due to age-related macular degeneration

PURPOSE: Pigment epithelium-derived growth factor (PEDF) is a potent inhibitor of angiogenesis that is found in the normal eye. The purpose of this study is to report decreased levels of PEDF in the vitreous of eyes with choroidal neovascularization (CNV) due to age-related macular degeneration (AMD). DESIGN: Prospective case-control study. METHODS: In a prospective case-control study, undiluted vitreous was collected from nine eyes of nine patients with CNV due to AMD and from an age-matched control group of 12 eyes of 12 patients with retinal disorders not involving neovascularization. Vitreous PEDF and vascular endothelial growth factor (VEGF) concentrations were determined by Western blot analyses and enzyme-linked immunosorbent assay (ELISA), respectively. Angiogenic activities of the vitreous samples were assessed in vitro using an endothelial cell chemotaxis assay. RESULTS: In vitreous samples from nine eyes with CNV due to AMD the mean ± SD PEDF level was 2.8 ng/μl ± 1.3 ng/μl. In vitreous samples from 12 age-matched control eyes the mean ± SD PEDF level was 16.4 ng/μl ± 7.1 ng/μl. The difference between the two groups was statistically significant ( P = .00003). No significant difference in vitreous VEGF concentration was seen between CNV/AMD samples and control samples ( P = .23). All CNV/AMD vitreous samples induced endothelial cell migration in vitro. No sample from age-matched non-age-related macular degeneration controls could induce endothelial cell migration, and 11 of 12 were able to block VEGF-induced migration in vitro. This inhibitory activity required active PEDF. CONCLUSION: The vitreous of patients with CNV due to AMD contained lower levels of PEDF and lacked the antiangiogenic activity of vitreous from age-matched controls. This suggests that loss of PEDF creates a permissive environment for CNV patients with AMD.

Prevention of ischemia-induced retinopathy by the natural ocular antiangiogenic agent pigment epithelium-derived factor.

Aberrant blood vessel growth in the retina that underlies the pathology of proliferative diabetic retinopathy and retinopathy of prematurity is the result of the ischemia-driven disruption of the normally antiangiogenic environment of the retina. In this study, we show that a potent inhibitor of angiogenesis found naturally in the normal eye, pigment epithelium-derived growth factor (PEDF), inhibits such aberrant blood vessel growth in a murine model of ischemia-induced retinopathy. Inhibition was proportional to dose and systemic delivery of recombinant protein at daily doses as low as 2.2 mg/kg could prevent aberrant endothelial cells from crossing the inner limiting membrane. PEDF appeared to inhibit angiogenesis by causing apoptosis of activated endothelial cells, because it induced apoptosis in cultured endothelial cells and an 8-fold increase in apoptotic endothelial cells could be detected in situ when the ischemic retinas of PEDF-treated animals were compared with vehicle-treated controls. The ability of low doses of PEDF to curtail aberrant growth of ocular endothelial cells without overt harm to retinal morphology suggests that this natural protein may be beneficial in the treatment of a variety of retinal vasculopathies.