αB crystallin is apically secreted within exosomes by polarized human retinal pigment epithelium and provides neuroprotection to adjacent cells
| العنوان: | αB crystallin is apically secreted within exosomes by polarized human retinal pigment epithelium and provides neuroprotection to adjacent cells |
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| المؤلفون: | Ram Kannan, Christine Spee, Stephen J. Ryan, Ernesto Barron, Mizuki Kitamura, Parameswaran G. Sreekumar, David R. Hinton |
| المصدر: | PLoS ONE, Vol 5, Iss 10, p e12578 (2010) PLoS ONE |
| بيانات النشر: | Public Library of Science (PLoS), 2010. |
| سنة النشر: | 2010 |
| مصطلحات موضوعية: | Programmed cell death, Blotting, Western, lcsh:Medicine, Enzyme-Linked Immunosorbent Assay, Caspase 3, Retinal Pigment Epithelium, Interphotoreceptor matrix, Biology, Mice, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Extracellular, medicine, Animals, Humans, alpha-Crystallins, lcsh:Science, Secretory pathway, 030304 developmental biology, 0303 health sciences, Retina, Microscopy, Confocal, Multidisciplinary, Retinal pigment epithelium, Cell Death, lcsh:R, Cell Polarity, Retinal, Cell Biology/Cellular Death and Stress Responses, Hydrogen Peroxide, beta-Crystallins, Ophthalmology/Macular Disorders, eye diseases, Cell Compartmentation, Cell biology, medicine.anatomical_structure, Microscopy, Fluorescence, Biochemistry, chemistry, 030221 ophthalmology & optometry, Ophthalmology/Retinal Disorders, lcsh:Q, sense organs, Research Article |
| الوصف: | αB crystallin is a chaperone protein with anti-apoptotic and anti-inflammatory functions and has been identified as a biomarker in age-related macular degeneration. The purpose of this study was to determine whether αB crystallin is secreted from retinal pigment epithelial (RPE) cells, the mechanism of this secretory pathway and to determine whether extracellular αB crystallin can be taken up by adjacent retinal cells and provide protection from oxidant stress. We used human RPE cells to establish that αB crystallin is secreted by a non-classical pathway that involves exosomes. Evidence for the release of exosomes by RPE and localization of αB crystallin within the exosomes was achieved by immunoblot, immunofluorescence, and electron microscopic analyses. Inhibition of lipid rafts or exosomes significantly reduced αB crystallin secretion, while inhibitors of classic secretory pathways had no effect. In highly polarized RPE monolayers, αB crystallin was selectively secreted towards the apical, photoreceptor-facing side. In support, confocal microscopy established that αB crystallin was localized predominantly in the apical compartment of RPE monolayers, where it co-localized in part with exosomal marker CD63. Severe oxidative stress resulted in barrier breakdown and release of αB crystallin to the basolateral side. In normal mouse retinal sections, αB crystallin was identified in the interphotoreceptor matrix. An increased uptake of exogenous αB crystallin and protection from apoptosis by inhibition of caspase 3 and PARP activation were observed in stressed RPE cultures. αB Crystallin was taken up by photoreceptors in mouse retinal explants exposed to oxidative stress. These results demonstrate an important role for αB crystallin in maintaining and facilitating a neuroprotective outer retinal environment and may also explain the accumulation of αB crystallin in extracellular sub-RPE deposits in the stressed microenvironment in age-related macular degeneration. Thus evidence from our studies supports a neuroprotective role for αB crystallin in ocular diseases. |
| اللغة: | English |
| تدمد: | 1932-6203 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ec707137cb3ec1be0c052653f32d6109Test http://europepmc.org/articles/PMC2951891?pdf=renderTest |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....ec707137cb3ec1be0c052653f32d6109 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 19326203 |
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