Retinal pigment epithelium (RPE) exosomes contain signaling phosphoproteins affected by oxidative stress. 2013

Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
CNR Institute of Neuroscience, Viale G. Colombo 3, 35121 Padova, Italy; Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy. Electronic address: lucia.biasutto@cnr.it.

Age-related macular degeneration (AMD) is a leading cause of vision loss and blindness among the elderly population in the industrialized world. One of the typical features of this pathology is the gradual death of retinal pigment epithelial (RPE) cells, which are essential for maintaining photoreceptor functions and survival. The etiology is multifactorial, and oxidative stress is clearly one of the key factors involved in disease pathogenesis (Plafker, Adv. Exp. Med. Biol. 664 (2010) 447-56; Qin, Drug Dev. Res. 68 (2007) 213-225). Recent work has revealed the presence of phosphorylated signaling proteins in the vitreous humour of patients affected by AMD or other retinal diseases. While the location of these signaling proteins is typically the cell membrane or intracellular compartments, vitreous samples were proven to be cell-free (Davuluri et al., Arch. Ophthalmol. 127 (2009) 613-21). To gain a better understanding of how these proteins can be shed into the vitreous, we used reverse phase protein arrays (RPMA) to analyze the protein and phosphoprotein content of exosomes shed by cultured ARPE-19 cells under oxidative stress conditions. Seventy two proteins were shown to be released by ARPE-19 cells and compartmentalized within exosomes. Forty one of them were selectively detected in their post-translationally modified form (i.e., phosphorylated or cleaved) for the first time in exosomes. Sets of these proteins were linked together reflecting activation of pathway units within exosomes. A subset of (phospho)proteins were altered in exosomes secreted by ARPE-19 cells subjected to oxidative stress, compared to that secreted by control/non stressed cells. Stress-altered exosome proteins were found to be involved in pathways regulating apoptosis/survival (i.e, Bak, Smac/Diablo, PDK1 (S241), Akt (T308), Src (Y416), Elk1 (S383), ERK 1/2 (T202/Y204)) and cell metabolism (i.e., AMPKα1 (S485), acetyl-CoA carboxylase (S79), LDHA). Exosomes may thus represent the conduit through which membrane and intracellular signaling proteins are released into the vitreous. Changes in their (phospho)protein content upon stress conditions suggest their possible role in mediating cell-cell signaling during physio-pathological events; furthermore, exosomes may represent a potential source of biomarkers.

UI MeSH Term Description Entries
D008954 Models, Biological Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment. Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D010750 Phosphoproteins Phosphoprotein
D012015 Reference Standards A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy. Standard Preparations,Standards, Reference,Preparations, Standard,Standardization,Standards,Preparation, Standard,Reference Standard,Standard Preparation,Standard, Reference
D002478 Cells, Cultured Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others. Cultured Cells,Cell, Cultured,Cultured Cell
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015398 Signal Transduction The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway. Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal
D017382 Reactive Oxygen Species Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of SIGNAL TRANSDUCTION and GENE EXPRESSION, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS. Active Oxygen Species,Oxygen Radical,Oxygen Radicals,Pro-Oxidant,Reactive Oxygen Intermediates,Active Oxygen,Oxygen Species, Reactive,Pro-Oxidants,Oxygen, Active,Pro Oxidant,Pro Oxidants,Radical, Oxygen
D055213 Retinal Pigment Epithelium The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment. Epithelium, Retinal Pigment,Pigment Epithelium, Retinal
D055354 Exosomes A type of extracellular vesicle, containing RNA and proteins, that is secreted into the extracellular space by EXOCYTOSIS when MULTIVESICULAR BODIES fuse with the PLASMA MEMBRANE.
D018384 Oxidative Stress A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi). Anti-oxidative Stress,Antioxidative Stress,DNA Oxidative Damage,Nitro-Oxidative Stress,Oxidative Cleavage,Oxidative DNA Damage,Oxidative Damage,Oxidative Injury,Oxidative Nitrative Stress,Oxidative Stress Injury,Oxidative and Nitrosative Stress,Stress, Oxidative,Anti oxidative Stress,Anti-oxidative Stresses,Antioxidative Stresses,Cleavage, Oxidative,DNA Damage, Oxidative,DNA Oxidative Damages,Damage, DNA Oxidative,Damage, Oxidative,Damage, Oxidative DNA,Injury, Oxidative,Injury, Oxidative Stress,Nitrative Stress, Oxidative,Nitro Oxidative Stress,Nitro-Oxidative Stresses,Oxidative Cleavages,Oxidative DNA Damages,Oxidative Damage, DNA,Oxidative Damages,Oxidative Injuries,Oxidative Nitrative Stresses,Oxidative Stress Injuries,Oxidative Stresses,Stress Injury, Oxidative,Stress, Anti-oxidative,Stress, Antioxidative,Stress, Nitro-Oxidative,Stress, Oxidative Nitrative,Stresses, Nitro-Oxidative

Related Publications

Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
January 2013, PloS one,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
January 2017, PloS one,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
June 2019, Redox biology,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
January 1975, Modern problems in ophthalmology,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
April 1989, Nippon Ganka Gakkai zasshi,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
April 1989, Nippon Ganka Gakkai zasshi,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
January 2015, Pharmaceutical research,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
October 2020, Redox biology,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
June 2004, Experimental eye research,
Lucia Biasutto, and Antonella Chiechi, and Robin Couch, and Lance A Liotta, and Virginia Espina
April 2011, The British journal of ophthalmology,
Copied contents to your clipboard!