angiogenin and Macular-Degeneration

To determine whether pretreatment of retinal pigmented epithelial (RPE) cells with lutein can affect the response of cells to bevacizumab therapy.. One human RPE cell line (ARPE-19) was used for all experiments. The cells were treated with lutein in different concentrations (0.01, 0.1, 1, 10, or 100 μg/ml). After 24 h, all plates were treated with bevacizumab (0.25 mg/ml). Media were harvested 24 h later for sandwich ELISA-based angiogenesis arrays. A Quantibody Human Angiogenesis Array was used in order to quantify the secretion of the following 10 proangiogenic cytokines: angiogenin, ANG2, EGF, bFGF, HB-EGF, PDGF-BB, leptin, PIGF, HGF and VEGF.. Treatment with bevacizumab alone led to a significant decrease in VEGF, as well as a significant increase in angiogenin and bFGF. Pretreatment with 0.1 and 1.0 μg/ml of lutein led to significant decreases in both bFGF and angiogenin following treatment with bevacizumab compared to bevacizumab treatment alone. Lutein alone did not modify the secretion of proangiogenic cytokines.. Pretreatment of human RPE cells in culture with specific doses of lutein prior to bevacizumab treatment mitigated the increase in bFGF and angiogenin caused by bevacizumab monotherapy.

Topics: Angiogenesis Inhibitors; Bevacizumab; Cell Survival; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Humans; Lutein; Macular Degeneration; Middle Aged; Retinal Pigment Epithelium; Ribonuclease, Pancreatic; Signal Transduction

Age-related macular degeneration (AMD) is currently the leading cause of blindness in developed countries. Bevacizumab is a widely used anti-VEGF agent that is a commonly applied therapy for neovascular AMD; however, a consequence of bevacizumab therapy may be the activation of compensatory angiogenic signalling. Combination of bevacizumab with 3,4 dihydroxyphenyl ethanol (DPE) may attenuate this compensatory signalling. The goal of the study was to investigate this therapeutic option in a human retinal pigment epithelial cell line (ARPE-19).. ARPE-19 cells were incubated under both normoxic and hypoxic conditions. The cells were treated as follows: control, 100 µM DPE, 0.25 mg/ml bevacizumab, the combination of DPE and bevacizumab. Media was harvested after 24 h for sandwich ELISA-based angiogenesis assays. The secretion of the following 10 pro-angiogenic cytokines was measured: angiogenin, ANG2, EGF, bFGF, HB-EGF, PDGF-BB, Leptin, PIGF, HGF, and VEGF-A.. Treatment of ARPE-19 cells with bevacizumab significantly increased the secretion of angiogenin. Secretion of angiogenin and VEGF-A were significantly reduced following treatment with DPE under both normoxia and hypoxia. In addition, angiogenin secretion was significantly reduced following treatment with the combination of DPE and bevacizumab compared to bevacizumab alone.. Compensatory angiogenic signalling may occur in neovascular AMD following treatment with bevacizumab. Here we show that DPE, both alone and in combination with bevacizumab, can reduce the secretion of angiogenin, a cytokine that has been upregulated following treatment with bevacizumab in RPE cells. Therefore, DPE may represent a possible therapeutic agent to be used in combination with bevacizumab for the treatment of neovascular AMD.

Topics: Antioxidants; Cells, Cultured; Enzyme-Linked Immunosorbent Assay; Humans; Macular Degeneration; Phenylethyl Alcohol; Retinal Pigment Epithelium; Ribonuclease, Pancreatic

Age-related macular degeneration (AMD) is a common blinding disease in the elderly population. AMD is frequently complicated by choroidal neovascularization, causing irreversible losses in visual acuity. Proteins that induce pathologic angiogenesis in other systems include angiogenin, a small protein involved in angiogenesis in tumor metastases. Our goal was to determine if angiogenin participates in angiogenesis during choroidal neovascular membrane formation in AMD.. The expression of angiogenin in the human retina and retinal pigment epithelium (RPE)-choroid was determined using reverse-transcription (RT)-PCR and immunoblotting. Localization of angiogenin in human control eyes and in eyes with choroidal neovascularization was determined using immunohistochemistry. Potential angiogenin-mediated effects on endothelial cell migration, as well as angiogenin internalization by Rf/6a cells, were determined.. Angiogenin was synthesized by the human choroid and retina and localized to normal and pathologic vasculature. Angiogenin did not change the migratory behavior of Rf/6a chorioretinal endothelial cells; however, these cells did internalize exogenous angiogenin in culture.. Chorioretinal endothelial cells bind and internalize angiogenin, a protein localized to the choroid in normal eyes, as well as in some drusen and in neovascular membranes in AMD eyes. Angiogenin has been shown to participate in angiogenesis in other tissues. Although angiogenin does not increase the migratory behavior of these cells, it may play a role in other aspects of endothelial cell activation in neovascular AMD.

Topics: Aged, 80 and over; Cell Movement; Cell Nucleus; Cells, Cultured; Choroid; Endocytosis; Endothelial Cells; Gene Expression Regulation; Humans; Immunoblotting; Macular Degeneration; Polymerase Chain Reaction; Protein Transport; Retinal Pigment Epithelium; Ribonuclease, Pancreatic

The vitreous levels of angiogenin, which is a potent blood vessel-inducing protein, were measured to determine their association with proliferative diabetic retinopathy (PDR). Undiluted vitreous fluid specimens were collected from 30 eyes with PDR at the time of vitrectomy. A sandwich enzyme-liked immunosorbent assay was then used to quantitate the levels of angiogenin. As a control we determined the levels in the specimens from 21 patients with proliferative vitreoretinopathy (PVR) and 4 patients with idiopathic macular epiretinal membrane (IERM). The average angiogenin level in the eyes with PDR was 43.7 ng/ml, and no significant difference was observed among PDR, PVR and their reoperation cases. In the category of IERM, the mean concentration of angiogenin was 2.1 ng/ml, which was significantly lower than that of the PDR and PVR cases. Our study thus demonstrated a significant increase in the vitreous angiogenin levels in eyes with PDR, PVR and those undergoing reoperation for these conditions in comparison to eyes with IERM. We therefore postulated that the elevated angiogenin levels thus reflected a breakdown of the blood-ocular barrier in eyes with PDR and PVR.

Topics: Adult; Aged; Angiogenesis Inducing Agents; Blood-Retinal Barrier; Diabetic Retinopathy; Enzyme-Linked Immunosorbent Assay; Female; Humans; Macular Degeneration; Male; Middle Aged; Proteins; Retinal Neovascularization; Ribonuclease, Pancreatic; Vitreoretinopathy, Proliferative; Vitreous Body