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Yamoah A, Tripathi P, Guo H, Scheve L, Walter P, Johnen S, Müller F, Weis J, Goswami A. Early Alterations of RNA Binding Protein (RBP) Homeostasis and ER Stress-Mediated Autophagy Contributes to Progressive Retinal Degeneration in the rd10 Mouse Model of Retinitis Pigmentosa (RP). Cells 2023; 12:cells12071094. [PMID: 37048167 PMCID: PMC10092976 DOI: 10.3390/cells12071094] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 04/14/2023] Open
Abstract
The retinal degeneration 10 (rd10) mouse model is widely used to study retinitis pigmentosa (RP) pathomechanisms. It offers a rather unique opportunity to study trans-neuronal degeneration because the cell populations in question are separated anatomically and the mutated Pde6b gene is selectively expressed in rod photoreceptors. We hypothesized that RNA binding protein (RBP) aggregation and abnormal autophagy might serve as early pathogenic events, damaging non-photoreceptor retinal cell types that are not primarily targeted by the Pde6b gene defect. We used a combination of immunohistochemistry (DAB, immunofluorescence), electron microscopy (EM), subcellular fractionation, and Western blot analysis on the retinal preparations obtained from both rd10 and wild-type mice. We found early, robust increases in levels of the protective endoplasmic reticulum (ER) calcium (Ca2+) buffering chaperone Sigma receptor 1 (SigR1) together with other ER-Ca2+ buffering proteins in both photoreceptors and non-photoreceptor neuronal cells before any noticeable photoreceptor degeneration. In line with this, we found markedly altered expression of the autophagy proteins p62 and LC3, together with abnormal ER widening and large autophagic vacuoles as detected by EM. Interestingly, these changes were accompanied by early, prominent cytoplasmic and nuclear aggregation of the key RBPs including pTDP-43 and FET family RBPs and stress granule formation. We conclude that progressive neurodegeneration in the rd10 mouse retina is associated with early disturbances of proteostasis and autophagy, along with abnormal cytoplasmic RBP aggregation.
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Affiliation(s)
- Alfred Yamoah
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- EURON-European Graduate School of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Priyanka Tripathi
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- EURON-European Graduate School of Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Haihong Guo
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Leonie Scheve
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Peter Walter
- Department of Ophthalmology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Sandra Johnen
- Department of Ophthalmology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Frank Müller
- Institute of Biological Information Processing, Molecular and Cellular Physiology, IBI-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Joachim Weis
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
| | - Anand Goswami
- Institute of Neuropathology, University Hospital RWTH Aachen, 52074 Aachen, Germany
- Department of Neurology, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Department of Neurology, Eleanor and Lou Gehrig ALS Center, Columbia University, New York, NY 10032, USA
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