Levels Of PEDF Research Articles

Proliferative and inflammatory factors in the vitreous of patients with proliferative diabetic retinopathy.

Purpose:The purpose was to measure the concentrations of various cytokines and growth factors (including vascular endothelial growth factor [VEGF] and pigment epithelium-derived factor [PEDF]) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate interaction between inflammatory and proliferative factors in the genesis of PDR.Materials and Methods:Vitreous samples from 32 eyes with PDR and 25 eyes without diabetes mellitus and signs of DR (control) were collected. Vitreous concentrations of VEGF, PEDF, monocyte chemotactic protein-1 (MCP-1), interleukin-4 (IL-4), IL-6, IL-8, IL-10, IL-17A, and secretory immunoglobulin A (sIgA) were simultaneously measured using enzyme-linked immunoassay.Results:Vitreous levels of VEGF, PEDF, IL-17A, IL-6, IL-8, IL-4, and sIgA were significantly (Π < 0.05) higher in eyes with PDR compared to control. The concentration of VEGF was more than 17-times higher than in control, and the concentration of PEDF was not changed oppositely and was also higher (1.45-times) compared to control, that may indicate disturbances of compensatory mechanisms in angiogenesis regulation in PDR. Significant (P < 0.05) positive correlations were observed between vitreous concentrations of VEGF and IL-17A (r = 0.45), VEGF and IL-8 (r = 0.48), VEGF and IL-4 (r = 0.51), PEDF and IL-17A (r = 0.48), PEDF and IL-8 (r = 0.59), MCP-1 and PEDF (r = 0.72), MCP-1 and IL-8 (r = 0.45), IL-4 and IL-17A (r = 0.65), IL-4 and IL-8 (r = 0.71), IL-8 and IL-17A (r = 0.59).Conclusions:Significantly raised levels of inflammatory and proliferative factors and numerous positive correlations between them may demonstrate a significant role of activation of vascular proliferation and local inflammation in the pathogenesis of PDR.

MiR-9 regulates the post-transcriptional level of VEGF165a by targeting SRPK-1 in ARPE-19 cells.

To investigate the effect of the overexpression of miRNA-9 to the ratio of pro- and anti-angiogenic isoforms of vascular endothelial growth factor (VEGF) in human retinal pigment cells (ARPE-19). Oxidative stress was induced to ARPE-19 cells by 4-hydroxynonenal (4-HNE), tert-butyl hydroperoxide (t-BH), and hypoxia chamber with 1% O₂. Expression patterns of miRNAs were validated by qPCR. Relative mRNA levels of VEGF and PEDF were measured by semi-quantitative PCR. After the transfection of miR-9 mimic and inhibitor, transcriptional levels of VEGF165a, VEGF 165b, and SRPK-1 were measured by qPCR. We demonstrated that miR-9 expression is decreased in ARPE-19 human retinal pigment cells under hypoxic stress induced by 4-HNE, a lipid peroxidation end-product. We observed that miR-9 mimic transfection of ARPE-19 inhibited one of its targets, serine-arginine protein kinase-1 (SRPK-1), modulating the transcriptional level of VEGF165b. Transfection of miR-9 reduced the alternative splicing of VEGF165a mRNA in ARPE-19 cells under hypoxic conditions, suggesting that miR-mediated regulation of alternative splicing could be a potential therapeutic target in neovascular pathologies. Hypoxic stress decreased the miR-9 level in ARPE-19 cells, which increased the transcriptional level of SRPK-1, resulting in alternative splicing shift to pro-angiogenic isoforms of VEGF165 in human retinal pigment epithelial cells.

THU0525 Metaflammation, PEDF and Chemerin: Potential Systemic Factors Which Link Obesity to Response to Therapy in Early Rheumatoid Arthritis

BackgroundObesity per se is a systemic, low-grade inflammatory state and the adipose tissue is an endocrine organ that releases bioactive substances, including pro-inflammatory cytokines, like TNFα and IL6 and specific...

Identification of emetine as a therapeutic agent that targets pigment epithelium derived factor - mediated inflammation and improves hyperglycemia in murine models of type 1 diabetes (IRM9P.728)

Abstract Pigment epithelium derived factor (PEDF) is a 50kDa secreted protein with inflammatory, antiangiogenic and neurotrophic properties. Elevated levels of PEDF are significantly associated with metabolic diseases including type 1 and type 2 diabetes, metabolic syndrome, and insulin resistance. PEDF administration to naïve animals result in the development of insulin resistance, and neutralization of PEDF with anti-PEDF antibodies improves the clinical outcome. Here we have identified a clinical drug candidate that attenuates PEDF mediated inflammation. Using a high-throughput screening approach, murine macrophages were stimulated with PEDF in the presence or absence of clinical drug candidates, and levels of secreted TNF analyzed. Following screening of 1,600 clinical candidate compounds, three lead compounds were identified, one being emetine, that dose dependently reduce PEDF induced macrophage activation without toxicity. Surface plasmon resonance analysis revealed that emetine binds to PEDF with high affinity (kD&amp;lt;25nM), and inhibits PEDF binding to its receptor adipose triglyceride lipase. Additionally, emetine reduces endocytosis of PEDF into macrophages. Administration of emetine to murine models of type 1 diabetes improves hyperglycemia, suppresses circulating levels of anti-insulin antibodies, and reduces pancreatic TNF and PEDF. Our studies suggest that emetine attenuates PEDF mediated inflammation, and has a therapeutic potential for treating type 1 diabetes.

Serum pigment epithelium-derived factor levels are independently correlated with the presence of coronary artery disease

BackgroundPigment epithelium-derived factor (PEDF) has been proved to be closely correlated with metabolic syndrome (MetS) and its components that are all risk factors of cardiovascular disease and may play a protective role against vascular injury and atherosclerosis. The present study was designed to investigate the relationship between serum PEDF and coronary artery disease (CAD).MethodsA total of 312 consecutive in-patients (including 228 with CAD and 197 with MetS) who underwent coronary angiography were enrolled. Serum PEDF was measured by sandwich enzyme immunoassay and used to carry out multivariate stepwise regression analysis to assess correlation with patient demographic and clinical parameters. Multiple logistic regression analysis was performed to identify factors independently correlated with CAD.ResultsPatients with MetS had significantly higher levels of serum PEDF than non-MetS subjects (11.1(8.2, 14.2) vs. 10.1(7.6, 12.4) μg/mL; P < 0.05). Patients with CAD also had significantly higher serum PEDF than non-CAD subjects (11.0(8.1, 14.2) vs. 10.3(8.1, 12.8) μg/mL; P < 0.05). Triglyceride (TG), C-reactive protein (CRP), estimated glomerular filtration rate (eGFR), and hypoglycemic therapy were independently correlated with serum PEDF levels, and serum PEDF was independently positively correlated with CAD.ConclusionsSerum PEDF levels are independently positively associated with CAD in a Chinese population. Elevated PEDF may act as a protective response against vascular damage and subsequent CAD.

Levels of PEDF in Pleural Effusions from Lung Adenocarcinoma and Benign Disease Patients

Anti-tumor properties assigned to PEDF, beside its role as an inhibitor of angiogenesis, make it a promising candidate in the search of new biomarkers for malignancy. In this study levels of PEDF were investigated in pleural effusions from lung adenocarcinoma and benign inflammatory disease patients. The mean PEDF concentration in the malignant group was slightly superior to that in patients suffering benign diseases (4.59 μg/mL vs 3.97 μg/mL), although the difference did not reach statistical significance (P0.166). Pleural effusion PEDF levels were not related to gender, age, smoking habit or pleural effusion size. We also investigated the possible relationship of PEDF levels in pleural effusion regarding clinicopathological features. Correlations were found for monocytes (P0.010) and polymorphonuclear leukocytes (P0.023) with PEDF levels in pleural effusion of malignant origin.

Levels of PEDF in pleural effusions from lung adenocarcinoma and benign disease patients.

Anti-tumor properties assigned to PEDF, beside its role as an inhibitor of angiogenesis, make it a promising candidate in the search of new biomarkers for malignancy. In this study levels of PEDF were investigated in pleural effusions from lung adenocarcinoma and benign inflammatory disease patients. The mean PEDF concentration in the malignant group was slightly superior to that in patients suffering benign diseases (4.59 μg/mL vs 3.97 μg/mL), although the difference did not reach statistical significance (P 0.166). Pleural effusion PEDF levels were not related to gender, age, smoking habit or pleural effusion size. We also investigated the possible relationship of PEDF levels in pleural effusion regarding clinicopathological features. Correlations were found for monocytes (P 0.010) and polymorphonuclear leukocytes (P 0.023) with PEDF levels in pleural effusion of malignant origin.

Asymmetrical dimethylarginine level is independently associated with circulating levels of RAGE and PEDF

Asymmetrical dimethylarginine level is independently associated with circulating levels of RAGE and PEDF

Concurrent PEDF deficiency and Kras mutation induce invasive pancreatic cancer and adipose-rich stroma in mice

Background and aimsPigment epithelium-derived factor (PEDF), a non-inhibitory SERPIN with potent antiangiogenic activity, has been recently implicated in metabolism and adipogenesis, both of which are known to influence pancreatic cancer...

The Expression of PEDF and VEGF in the Gastric Wall of Prehepatic Portal Hypertensive Rats

Upper gastrointestinal bleeding of portal hypertension cases may result from gastric mucosal lesions due to portal hypertensive gastropathy. The pathological changes in the vessels of the gastric wall are very important in the pathogenesis of portal hypertensive gastropathy. However, the mechanisms of these pathological changes are not completely understood. In this study, we examined the expression levels of PEDF and VEGF in the gastric wall in rats with prehepatic portal hypertension. Eighteen healthy Wistar rats were randomly divided into groups A and B. Group A was used to establish the prehepatic portal hypertensive model and group B to evaluate a sham surgery. The VEGF and PEDF expression in the rat gastric wall were detected by immunohistochemical staining and western blotting. VEGF and PEDF were mainly expressed in the basal layer of the mucosal glands. The expression levels of VEGF and PEDF in group A were higher than that in group B at 7, 10 and 14 days after surgery. The expression levels of VEFG and PEDF in group B did not show significant changes. The results from the present study showed a significantly elevated expression of both VEGF and PEDF in the gastric walls during the development of portal hypertension. The expression of these proteins was mainly located in the basal layer of the gastric mucosa.

Intraocular levels of pigment epithelium-derived factor in patients with active uveitis

ObjectivePigment epithelium-derived factor (PEDF) is an antiangiogenic/neurotrophic dual functional factor, and recently it was also shown to mediate antioxidative and antiinflammatory action. The purpose of this study was to evaluate the levels of PEDF in the aqueous humor in eyes with idiopathic acute anterior uveitis (IAAU). MethodsA comparative control study. Aqueous humor was collected from 20 eyes of 20 patients with IAAU. The control group included 20 aqueous humor samples from 20 patients who underwent a cataract surgery and without any other ocular or systemic diseases. Levels of PEDF were determined with the ELISA test. ResultsConcentration of PEDF in aqueous humor was remarkably higher in patients with IAAU than in control subjects (Mann-Whitney U test, P<.001). Levels of PEDF were 6,291,637.70±8,564,836.48pg/ml (mean±SD) in eyes with IAAU and 449,178.10±158,670.19pg/ml in the eyes of the control group. ConclusionThe aqueous humor PEDF levels are increased in eyes with IAAU and may be increased as self-protection against inflammatio

Ratio of the vitreous vascular endothelial growth factor and pigment epithelial-derived factor in Eales disease

Eales disease (ED) is an idiopathic inflammatory venous occlusion of the peripheral retina. As neovascularization is prominent in ED, this study attempts to look at the ratio of VEGF, the angiogenic factor, and PEDF, an anti-angiogenic factor in the vitreous of ED patients in comparison with the macular hole (MH) and Proliferative Diabetic Retinopathy (PDR). Vitreous levels of VEGF and PEDF were determined in the undiluted vitreous specimen obtained from 26 ED cases, 17 PDR, and seven patients with MH. The vitreous levels of VEGF and PEDF were estimated by ELISA. The immunohistochemistry (IHC) for VEGF and PEDF were done in the epiretinal membrane of ED and PDR case. The VEGF/PEDF ratio was found to be significantly increased in ED (p = 0.014) and PDR (p = 0.000) compared to MH. However the ratio was 3.5-fold higher in PDR than ED (p = 0.009). The IHC data on the ERM specimen from ED showed the presence of VEGF and PEDF similar to PDR. The high angiogenic potential seen as the ratio of VEGF/PEDF correlates with the peak clinical onset of the disease in the age group 21–30 years and the diseases usually self-resolves above the age of 40, which is reflected by the low ratio of VEGF/PEDF. The study shows that the VEGF/PEDF ratio is significantly increased in ED though the angiogenic potential is higher in PDR than in ED. Clinically Eales Disease is known as a self-limiting disease, while PDR is a progressive disease.

Increased serum pigment epithelium derived factor levels in Type 2 diabetes patients

Serum PEDF levels (mean (S.D.)) were increased in 96 Type 2 diabetic vs. 54 non-diabetic subjects; 5.3 (2.8) vs. 3.2 (2.0) μg/ml, p < 0.001. In diabetes, PEDF correlated with BMI, serum creatinine and LDL-cholesterol, but not with other lipids, HbA1c or CRP. PEDF did not differ by drugs, complications, or gender.

Regulating the angiogenic balance in tissues:A potential role for the proliferative state of fibroblasts

A balance between angiogenesis inducers and inhibitors in the microenvironment controls the rate of new blood vessel formation. We hypothesized that fibroblasts, an important cellular constituent of the tissue stroma, secrete molecules that contribute to this balance. We further hypothesized that fibroblasts secrete molecules that promote angiogenesis when they are in a proliferative state and molecules that inhibit angiogenesis when they are not actively cycling (quiescent). Microarray analysis revealed that angiogenesis inducers and inhibitors are regulated as fibroblasts transition into a quiescent state and re-enter the cell cycle in response to changes in serum. To assess whether changes in transcript levels result in changes in the levels of secreted proteins, we collected conditioned medium from proliferating and quiescent fibroblasts and performed immunoblotting for selected proteins. Secreted protein levels of the angiogenesis inhibitor PEDF were higher in quiescent than proliferating fibroblasts. Conversely, proliferating fibroblasts secreted increased levels of the angiogenesis inducer VEGF-C. For the angiogenesis inhibitor thrombospondin-2, quiescent cells secreted a prominent 160 kDa form in addition to the 200 kDa form secreted by proliferating and restimulated fibroblasts. Using immunohistochemistry we discovered that fibroblasts surround blood vessels and that the angiogenesis inhibitor PEDF is expressed by quiescent fibroblasts in uterine tissue, supporting a role for PEDF in maintaining quiescence of the vasculature. This work takes a new approach to the study of angiogenesis by examining the expression of multiple angiogenesis genes secreted from a key stromal cell, the fibroblast.

P73 isoforms affect VEGF, VEGF165b and PEDF expression in human colorectal tumors: VEGF165b downregulation as a marker of poor prognosis

The secreted mitogen vascular endothelial growth factor, VEGF, plays a pivotal role in angiogenesis. Hypoxia, inactivation of p53 and oncogenic K-Ras induce VEGF expression. Other factors such as p73 may also affect VEGF levels. Curiously, p73 may also regulate angiogenesis by affecting the expression of the pigment epithelium-derived factor, PEDF. Additionally, VEGF might harbor additional functions through the activation of E2F transcription factors. Recently, a new VEGF variant formed by alternative splicing, VEGF(165)b, has been described as exerting anti-angiogenic activity. We study here whether p73 isoforms levels -TAp73 and DeltaTAp73- and p53 and K-Ras status affect the expression of the above-mentioned angiogenesis-related genes (through the correlation between their expressions), the prognostic value of VEGF(165)b and PEDF and the correlation between VEGF and E2F-1 levels. Tumor and normal tissue of 112 colorectal cancer patients was analyzed to evaluate: (i) levels of TAp73, DeltaTAp73, VEGF, VEGF(165)b, PEDF and E2F-1 by quantitative real-time RT-PCR, (ii) p53 status by immunohistochemistry and (iii) mutations in the first exon of K-Ras by PCR-SSCP. Tumor characteristics were examined in each patient. Associations were observed between: (i) specific p73 isoforms and VEGF and VEGF(165)b expression; (ii) DeltaEx2p73 variant and downregulation of PEDF; (iii) VEGF and PEDF expression; (iv) inactive p53 and VEGF(165)b levels; (v) oncogenic K-Ras and PEDF downregulation; (vi) E2F-1 and VEGF expressions; (vii) VEGF(165)b downregulation and poor prognosis parameters of tumors. We conclude that the levels of p73 isoforms could affect the expression of VEGF, VEGF(165)b and PEDF. This scenario becomes complicated because a feedback between VEGF and PEDF may exist. VEGF may activate the E2F-1 factor. Mutations in K-Ras could negatively regulate PEDF expression. p53 inactivation might result in compensatory mechanisms such as over-expression of VEGF(165)b. Our data support the role of VEGF(165)b as a tumor suppressor factor in colorectal carcinogenesis and its possible prognosis value.

Changes in growth factor expression in normal aging of the rat retina

Although much is known about the growth factor changes in ocular tissues during various diseases, little is known about normal aging of the retina. In order to further understand normal aging in the retina, we characterized age-related changes of growth factor expression in three different ages of rat retina. Real time PCR and protein analysis was conducted to investigate steady state mRNA expression and protein levels of VEGF, VEGFR2, PEDF, Ang-1, Tie-2, EphB4 and ephrinB2 in the retina of 8-, 22-, and 32-month-old Brown Norway X Fischer 344 F1 hybrid rats. An increase of VEGF protein levels was found at 32 months compared to 8 and 22 months of age. VEGFR2 protein was found to be increased at 22 and 32 months compared to 8 months. PEDF protein levels were reduced at 22 and 32 months. Tie-2 levels were found to be significantly decreased by 32 months compared to 8 months of age, while ephrinB2 was found to be significantly lower at both 22 and 32 months compared to 8 months of age. The increases found in VEGF and its receptor VEGFR2, with the simultaneous decrease of PEDF protein levels, may stimulate an environment that is well suited for neovascularization in the normal aging retina. Overall, these results suggest that normal aging produces substantial changes in gene expression and protein levels.

β-adrenergic receptor regulation of pigment epithelial-derived factor expression in rat retina

In the present study, we have examined a potential mechanism by which sympathetic nerves regulate PEDF and whether its down regulation may be responsible for increased capillary density observed after sympathectomy. Six weeks post-sympathectomy, eyes were removed from female Sprague–Dawley rats for Western blot analysis, RNA isolation, real-time PCR, and immunohistochemistry for measurement of PEDF expression. The contralateral or left eye was used as an intra-animal control. In addition, retinal pigment epithelial cells were grown in culture and treated with norepinephrine and propranolol. An ELISA assay was used to determine the amount of PEDF secreted into the RPE media. Quantitative results of Western blot analysis and real-time PCR confirm that both steady-state gene expression and protein levels of PEDF are significantly decreased in the sympathectomized retina ( P < 0.05) when compared to the contralateral retina. Qualitative results of immunohistochemistry verify that PEDF is located predominantly in the RPE cell layer of the retina, and levels are decreased in the sympathectomized retina. ELISA results illustrate that norepinephrine significantly increases PEDF secretion by RPE cells and propranolol slightly decreases PEDF secretion into RPE cell medium. In conclusion, down regulation of PEDF may contribute to the increased capillary density of the outer plexiform layer in the retina noted after sympathectomy. Furthermore, expression of PEDF was significantly increased after treatment of norepinephrine in RPE medium demonstrating a role of β-adrenergic regulation of PEDF. Since sympathetic nerves are damaged in diabetes and PEDF appears to be regulated by β-adrenergic receptors, these results suggest a role for sympathetic nerves in diabetic retinopathy. This knowledge, in turn, may be used for future treatment and prevention of diabetic retinopathy and other ocular diseases.

Expression of MATH1, a marker of cerebellar granule cell progenitors, identifies different medulloblastoma sub-types

In order to look for genetic markers helpful for the biological risk stratification of medulloblastomas (MBs) we assayed by real-time PCR expression levels of the following genes: MATH1, encoding a critical transcription factor for the differentiation of cerebellar granular cells (CGCs); PEDF, that encodes a trophic factor for CGCs and is located in a region of frequent allelic imbalance in MBs; and BIRC5, encoding the antiapoptotic protein survivin, usually overexpressed in malignancies. Expression levels of TRKC, higher in MBs with a more favorable prognosis, were also studied. Twenty-three patients were considered: MATH1 expression was strong in 14/23 and undetectable in the others. PEDF was up-regulated in 8/23, TRKC in 9/23, and BIRC5 in 23/23. MATH1 expression was significantly correlated with adult age ( p < 0.0001), tumor location in hemispheres rather than the vermis ( p < 0.0004), and PEDF and TRKC up-regulation ( p < 0.008 and p < 0.04, respectively). During development MATH1 is selectively expressed in the external germinal layer (EGL) of the cerebellum. Thus, MATH1 expression identifies a subgroup of MBs that derive from the EGL and arise during adult age into cerebellar hemispheres. MATH1 mRNA-positive MBs express high levels of PEDF and show a trend towards longer survival, in agreement with increased expression of TRKC. BIRC5 expression, which is strong in all MBs and absent in normal cerebellum, lacks any prognostic value but could be explored for selective targeting of therapeutic factors to MBs.