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Tsai T, Reinehr S, Deppe L, Strubbe A, Kluge N, Dick HB, Joachim SC. Glaucoma Animal Models beyond Chronic IOP Increase. Int J Mol Sci 2024; 25:906. [PMID: 38255979 PMCID: PMC10815097 DOI: 10.3390/ijms25020906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP), other mechanisms play a pivotal role in glaucoma onset and progression. For example, it is known that excitotoxicity, immunological alterations, ischemia, and oxidative stress contribute to the neurodegeneration in glaucoma disease. To study these effects and to discover novel therapeutic approaches, appropriate animal models are needed. In this review, we focus on various glaucoma animal models beyond an elevated IOP. We introduce genetically modified mice, e.g., the optineurin E50K knock-in or the glutamate aspartate transporter (GLAST)-deficient mouse. Excitotoxicity can be mimicked by injecting the glutamate analogue N-methyl-D-aspartate intravitreally, which leads to rapid RGC degeneration. To explore the contribution of the immune system, the experimental autoimmune glaucoma model can serve as a useful tool. Here, immunization with antigens led to glaucoma-like damage. The ischemic mechanism can be mimicked by inducing a high IOP for a certain amount of time in rodents, followed by reperfusion. Thereby, damage to the retina and the optic nerve occurs rapidly after ischemia/reperfusion. Lastly, we discuss the importance of optic nerve crush models as model systems for normal-tension glaucoma. In summary, various glaucoma models beyond IOP increase can be utilized.
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Affiliation(s)
| | | | | | | | | | | | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892 Bochum, Germany; (T.T.); (S.R.); (L.D.); (N.K.); (H.B.D.)
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2
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Mazumder AG, Julé AM, Sun D. Astrocytes of the optic nerve exhibit a region-specific and temporally distinct response to elevated intraocular pressure. Mol Neurodegener 2023; 18:68. [PMID: 37759301 PMCID: PMC10523752 DOI: 10.1186/s13024-023-00658-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND The optic nerve is an important tissue in glaucoma and the unmyelinated nerve head region remains an important site of many early neurodegenerative changes. In both humans and mice, astrocytes constitute the major glial cell type in the region, and in glaucoma they become reactive, influencing the optic nerve head (ONH) microenvironment and disease outcome. Despite recognizing their importance in the progression of the disease, the reactive response of optic nerve head astrocytes remains poorly understood. METHODS To determine the global reactive response of ONH astrocytes in glaucoma we studied their transcriptional response to an elevation in IOP induced by the microbead occlusion model. To specifically isolate astrocyte mRNA in vivo from complex tissues, we used the ribotag method to genetically tag ribosomes in astrocytes, restricting analysis to astrocytes and enabling purification of astrocyte-associated mRNA throughout the entire cell, including the fine processes, for bulk RNA-sequencing. We also assessed the response of astrocytes in the more distal myelinated optic nerve proper (ONP) as glaucomatous changes manifest differently between the two regions. RESULTS Astrocytes of the optic nerve exhibited a region-specific and temporally distinct response. Surprisingly, ONH astrocytes showed very few early transcriptional changes and ONP astrocytes demonstrated substantially larger changes over the course of the experimental period. Energy metabolism, particularly oxidative phosphorylation and mitochondrial protein translation emerged as highly upregulated processes in both ONH and ONP astrocytes, with the former showing additional upregulation in antioxidative capacity and proteolysis. Interestingly, optic nerve astrocytes demonstrated a limited neuroinflammatory response, even when challenged with a more severe elevation in IOP. Lastly, there were a greater number of downregulated processes in both astrocyte populations compared to upregulated processes. CONCLUSION Our findings demonstrate an essential role for energy metabolism in the response of optic nerve astrocytes to elevated IOP, and contrary to expectations, neuroinflammation had a limited overall role. The transcriptional response profile is supportive of the notion that optic nerve astrocytes have a beneficial role in glaucoma. These previously uncharacterized transcriptional response of optic nerve astrocytes to injury reveal their functional diversity and a greater heterogeneity than previously appreciated.
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Affiliation(s)
- Arpan G Mazumder
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, 02114, USA
| | - Amélie M Julé
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Daniel Sun
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, 02114, USA.
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3
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Nam MH, Nahomi RB, Pantcheva MB, Dhillon A, Chiodo VA, Smith WC, Nagaraj RH. AAV2-Mediated Expression of HspB1 in RGCs Prevents Somal Damage and Axonal Transport Deficits in a Mouse Model of Ocular Hypertension. Transl Vis Sci Technol 2022; 11:8. [DOI: 10.1167/tvst.11.11.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Mi-Hyun Nam
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Rooban B. Nahomi
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Mina B. Pantcheva
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Armaan Dhillon
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
| | - Vince A. Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - W. Clay Smith
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Ram H. Nagaraj
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA
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Rajeswaren V, Wong JO, Yabroudi D, Nahomi RB, Rankenberg J, Nam MH, Nagaraj RH. Small Heat Shock Proteins in Retinal Diseases. Front Mol Biosci 2022; 9:860375. [PMID: 35480891 PMCID: PMC9035800 DOI: 10.3389/fmolb.2022.860375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 03/11/2022] [Indexed: 11/29/2022] Open
Abstract
This review summarizes the latest findings on small heat shock proteins (sHsps) in three major retinal diseases: glaucoma, diabetic retinopathy, and age-related macular degeneration. A general description of the structure and major cellular functions of sHsps is provided in the introductory remarks. Their role in specific retinal diseases, highlighting their regulation, role in pathogenesis, and possible use as therapeutics, is discussed.
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Affiliation(s)
- Vivian Rajeswaren
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
| | - Jeffrey O. Wong
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
| | - Dana Yabroudi
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
| | - Rooban B. Nahomi
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
| | - Johanna Rankenberg
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
| | - Mi-Hyun Nam
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
- *Correspondence: Mi-Hyun Nam, ; Ram H. Nagaraj,
| | - Ram H. Nagaraj
- Department of Ophthalmology, Sue Anschutz-Rodgers Eye Center, School of Medicine, Aurora, CO, United States
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, United States
- *Correspondence: Mi-Hyun Nam, ; Ram H. Nagaraj,
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5
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Somvanshi RK, Zou S, Kadhim S, Padania S, Hsu E, Kumar U. Cannabinol modulates neuroprotection and intraocular pressure: A potential multi-target therapeutic intervention for glaucoma. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166325. [DOI: 10.1016/j.bbadis.2021.166325] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/22/2021] [Accepted: 12/09/2021] [Indexed: 12/31/2022]
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6
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The protective role of HSP27 in ocular diseases. Mol Biol Rep 2022; 49:5107-5115. [PMID: 35212927 DOI: 10.1007/s11033-022-07222-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 02/02/2022] [Indexed: 10/19/2022]
Abstract
Heat shock proteins (HSPs) are stress-induced proteins that are important constituents of the cell's defense system. The activity of HSPs enhances when the cell undergoes undesirable environmental conditions like stress. The protective roles of HSPs are due to their molecular chaperone and anti-apoptotic functions. HSPs have a central role in the eye, and their malfunction has been associated with the manifestation of ocular diseases. Heat shock protein 27 (HSP27, HSPB1) is present in various ocular tissues, and it has been found to protect the eye from disease states such as retinoblastoma, uveal melanoma, glaucoma, and cataract. But some recent studies have shown the destructive role of HSP27 on retinal ganglionic cells. Thus, this article summarizes the role of heat shock protein 27 in eye and ocular diseases and will focus on the expression, regulation, and function of HSP27 in ocular complications.
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7
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Geva M, Gershoni-Emek N, Naia L, Ly P, Mota S, Rego AC, Hayden MR, Levin LA. Neuroprotection of retinal ganglion cells by the sigma-1 receptor agonist pridopidine in models of experimental glaucoma. Sci Rep 2021; 11:21975. [PMID: 34753986 PMCID: PMC8578336 DOI: 10.1038/s41598-021-01077-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 10/20/2021] [Indexed: 12/21/2022] Open
Abstract
Optic neuropathies such as glaucoma are characterized by retinal ganglion cell (RGC) degeneration and death. The sigma-1 receptor (S1R) is an attractive target for treating optic neuropathies as it is highly expressed in RGCs, and its absence causes retinal degeneration. Activation of the S1R exerts neuroprotective effects in models of retinal degeneration. Pridopidine is a highly selective and potent S1R agonist in clinical development. We show that pridopidine exerts neuroprotection of retinal ganglion cells in two different rat models of glaucoma. Pridopidine strongly binds melanin, which is highly expressed in the retina. This feature of pridopidine has implications to its ocular distribution, bioavailability, and effective dose. Mitochondria dysfunction is a key contributor to retinal ganglion cell degeneration. Pridopidine rescues mitochondrial function via activation of the S1R, providing support for the potential mechanism driving its neuroprotective effect in retinal ganglion cells.
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Affiliation(s)
| | | | - Luana Naia
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Department of Neurobiology, Care Science and Society, Karolinska Institutet, Stockholm, Sweden
| | - Philip Ly
- The Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Sandra Mota
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ana Cristina Rego
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- FMUC-Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Michael R Hayden
- Prilenia Therapeutics, Herzliya, Israel
- The Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Leonard A Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.
- Montreal Neurological Institute, McGill University, Montreal, Canada.
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8
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Grotegut P, Hoerdemann PJ, Reinehr S, Gupta N, Dick HB, Joachim SC. Heat Shock Protein 27 Injection Leads to Caspase Activation in the Visual Pathway and Retinal T-Cell Response. Int J Mol Sci 2021; 22:E513. [PMID: 33419223 PMCID: PMC7825587 DOI: 10.3390/ijms22020513] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/21/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022] Open
Abstract
Heat shock protein 27 (HSP27) is one of the small molecular chaperones and is involved in many cell mechanisms. Besides the known protective and helpful functions of intracellular HSP27, very little is known about the mode of action of extracellular HSP27. In a previous study, we showed that intravitreal injection of HSP27 led to neuronal damage in the retina and optic nerve after 21 days. However, it was not clear which degenerative signaling pathways were induced by the injection. For this reason, the pathological mechanisms of intravitreal HSP27 injection after 14 days were investigated. Histological and RT-qPCR analyses revealed an increase in endogenous HSP27 in the retina and an activation of components of the intrinsic and extrinsic apoptosis pathway. In addition, an increase in nucleus factor-kappa-light-chain-enhancer of activated B cells (NFκB), as well as of microglia/macrophages and T-cells could be observed. In the optic nerve, however, only an increased apoptosis rate was detectable. Therefore, the activation of caspases and the induction of an incipient immune response seem to be the main triggers for retinal degeneration in this intravitreal HSP27 model.
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Affiliation(s)
| | | | | | | | | | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892 Bochum, Germany; (P.G.); (P.J.H.); (S.R.); (N.G.); (H.B.D.)
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9
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Tang J, Tang Y, Yi I, Chen DF. The role of commensal microflora-induced T cell responses in glaucoma neurodegeneration. PROGRESS IN BRAIN RESEARCH 2020; 256:79-97. [PMID: 32958216 DOI: 10.1016/bs.pbr.2020.06.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the last decade, new evidence has become increasingly more compelling that commensal microflora profoundly influences the maturation and function of resident immune cells in host physiology. The concept of gut-retina axis is actively being explored. Studies have revealed a critical role of commensal microbes linked with neuronal stress, immune responses, and neurodegeneration in the retina. Microbial dysbiosis changes the blood-retina barrier permeability and modulates T cell-mediated autoimmunity to contribute to the pathogenesis of retinal diseases, such as glaucoma. Heat shock proteins (HSPs), which are evolutionarily conserved, are thought to function both as neuroprotectant and pathogenic antigens of T cells contributing to cell protection and tissue damage, respectively. Activated microglia recruit and interact with T cells during this process. Glaucoma, characterized by the progressive loss of retinal ganglion cells, is the leading cause of irreversible blindness. With nearly 70 million people suffering glaucoma worldwide, which doubles the number of patients with Alzheimer's disease, it represents the most frequent neurodegenerative disease of the central nervous system (CNS). Thus, understanding the mechanism of neurodegeneration in glaucoma and its association with the function of commensal microflora may help unveil the secrets of many neurodegenerative disorders in the CNS and develop novel therapeutic interventions.
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Affiliation(s)
- Jing Tang
- Department of Ophthalmology, West China Hospital, Sichuan University, Sichuan, China; Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Yizhen Tang
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Irvin Yi
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Dong Feng Chen
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States.
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10
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Role of Heat Shock Proteins in Glaucoma. Int J Mol Sci 2019; 20:ijms20205160. [PMID: 31635205 PMCID: PMC6834184 DOI: 10.3390/ijms20205160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/19/2019] [Accepted: 09/20/2019] [Indexed: 02/06/2023] Open
Abstract
Glaucoma, one of the most common causes of blindness worldwide, is a multifactorial neurodegenerative disease characterized by damage of retinal ganglion cells and optic nerve degeneration. However, the exact mechanism leading to glaucoma is still not understood. Evidences suggest an immunological involvement in the pathogenesis. Among other immune responses, altered autoantibody patterns were found in glaucoma patients. Especially elevated antibody levels against heat shock proteins (HSPs), like HSP27 or HSP60, were identified. In an animal model, an immunization with these HSPs induced a pressure-independent retinal ganglion cell degeneration and axon loss, hence mimicking glaucoma-like damage. In addition, development of autoreactive antibodies, as well as a glia and T-cell activation, were described in these animals. Recently, we noted that intravitreal HSP27 injection likewise led to a degeneration of retinal ganglion cells and their axons. Therefore, HSP27 might have a direct damaging effect on retinal cells, and might play a key role in glaucoma.
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11
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Commensal microflora-induced T cell responses mediate progressive neurodegeneration in glaucoma. Nat Commun 2018; 9:3209. [PMID: 30097565 PMCID: PMC6086830 DOI: 10.1038/s41467-018-05681-9] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/18/2018] [Indexed: 01/18/2023] Open
Abstract
Glaucoma is the most prevalent neurodegenerative disease and a leading cause of blindness worldwide. The mechanisms causing glaucomatous neurodegeneration are not fully understood. Here we show, using mice deficient in T and/or B cells and adoptive cell transfer, that transient elevation of intraocular pressure (IOP) is sufficient to induce T-cell infiltration into the retina. This T-cell infiltration leads to a prolonged phase of retinal ganglion cell degeneration that persists after IOP returns to a normal level. Heat shock proteins (HSP) are identified as target antigens of T-cell responses in glaucomatous mice and human glaucoma patients. Furthermore, retina-infiltrating T cells cross-react with human and bacterial HSPs; mice raised in the absence of commensal microflora do not develop glaucomatous T-cell responses or the associated neurodegeneration. These results provide compelling evidence that glaucomatous neurodegeneration is mediated in part by T cells that are pre-sensitized by exposure to commensal microflora.
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12
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Reinehr S, Kuehn S, Casola C, Koch D, Stute G, Grotegut P, Dick HB, Joachim SC. HSP27 immunization reinforces AII amacrine cell and synapse damage induced by S100 in an autoimmune glaucoma model. Cell Tissue Res 2017; 371:237-249. [PMID: 29064077 DOI: 10.1007/s00441-017-2710-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 10/11/2017] [Indexed: 12/11/2022]
Abstract
Previous studies have revealed a loss of retinal ganglion cells (RGCs) and optic nerve fibers after immunization with the S100B protein. Addition of heat shock protein 27 (HSP27) also leads to a decrease of RGCs. Our present aim has been to analyze various retinal cell types after immunization with S100B or S100B + HSP27 (S100 + HSP). After 28 days, retinas were processed for immunohistology and Western blot. RGCs, immunostained for NeuN, were significantly decreased in the S100 and the S100 + HSP groups. Significantly fewer ChAT+ cells were noted in both groups, whereas parvalbumin+ cells were only affected in the S100 + HSP group. Western blot results also revealed fewer ChAT signals in both immunized groups. No changes were noted with regard to PKCα+ rod bipolar cells, whereas a significant loss of recoverin+ cone bipolar cells was observed in both groups via immunohistology and Western blot. The presynaptic marker Bassoon and the postsynaptic marker PSD95 were significantly reduced in the S100 + HSP group. Opsin+ and rhodopsin+ photoreceptors revealed no changes in either group. Thus, the inner retinal layers are affected by immunization. However, the combination of S100 and HSP27 has a stronger additive effect on the retinal synapses and AII amacrine cells.
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Affiliation(s)
- Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Christina Casola
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Dennis Koch
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Pia Grotegut
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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Yang S, Dizhoor A, Wilson DJ, Adamus G. GCAP1, Rab6, and HSP27: Novel Autoantibody Targets in Cancer-Associated Retinopathy and Autoimmune Retinopathy. Transl Vis Sci Technol 2016; 5:1. [PMID: 27152249 PMCID: PMC4855477 DOI: 10.1167/tvst.5.3.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 03/19/2016] [Indexed: 01/12/2023] Open
Abstract
PURPOSE Autoantibodies (AAbs) with different retinal specificities were reported in cancer-associated retinopathy (CAR) and autoimmune retinopathy (AR). The goal was to identify the small retinal proteins of apparent molecular mass of 23-kDa often recognized by patients' AAbs. METHODS Sera specific for a 23-kDa retinal protein of 173 patients were investigated retrospectively by Western blotting and double immunofluorescence confocal microscopy. A proteomic analysis revealed new 23-kDa protein candidates, including guanylyl cyclase-activating proteins (GCAPs), heat shock protein 27 (HSP27), and Rab6A GTPase (Rab6A). RESULTS Among the cohort of 173 patients, only 68 had anti-recoverin AAbs and the remaining 105 reacted with 4 unique proteins, which were identified as a Rab6A, HSP27, GCAP1, and GCAP2. Confocal images from a double labeling study confirmed the reactivity of AAbs with different types of cells in human retina, consistent with the target protein's respective cellular functions. Patients (62/173) had been diagnosed with various kinds of cancer, including 20% of patients who had anti-recoverin, 11% anti-Rab6A, and 5% anti-HSP27 AAbs. Only 50% of recoverin-seropositive patients had cancer and the individuals with anti-recoverin AAbs had a significantly higher likelihood to be diagnosed with cancer than patients with other anti-23-kDa AAbs. CONCLUSIONS The newly discovered retinal autoantigens may be involved in pathogenicity of CAR and AR. The recognition of AAbs against various retinal proteins associated with autoimmune retinal degeneration broadens the group of proteins related with these entities. TRANSLATIONAL RELEVANCE Patients with anti-recoverin, anti-GCAP1, anti-Rab6A, and anti-HSP27 AAbs represented diverse clinical phenotypes, so the presence of disease-associated AAbs provides important information for molecular diagnosis.
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Affiliation(s)
- Sufang Yang
- Casey Eye Institute, School of Medicine, Oregon Health and Science University, Portland, OR, USA
| | | | - David J Wilson
- Casey Eye Institute, School of Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Grazyna Adamus
- Casey Eye Institute, School of Medicine, Oregon Health and Science University, Portland, OR, USA
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14
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Piri N, Kwong JMK, Gu L, Caprioli J. Heat shock proteins in the retina: Focus on HSP70 and alpha crystallins in ganglion cell survival. Prog Retin Eye Res 2016; 52:22-46. [PMID: 27017896 PMCID: PMC4842330 DOI: 10.1016/j.preteyeres.2016.03.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 03/14/2016] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
Abstract
Heat shock proteins (HSPs) belong to a superfamily of stress proteins that are critical constituents of a complex defense mechanism that enhances cell survival under adverse environmental conditions. Cell protective roles of HSPs are related to their chaperone functions, antiapoptotic and antinecrotic effects. HSPs' anti-apoptotic and cytoprotective characteristics, their ability to protect cells from a variety of stressful stimuli, and the possibility of their pharmacological induction in cells under pathological stress make these proteins an attractive therapeutic target for various neurodegenerative diseases; these include Alzheimer's, Parkinson's, Huntington's, prion disease, and others. This review discusses the possible roles of HSPs, particularly HSP70 and small HSPs (alpha A and alpha B crystallins) in enhancing the survival of retinal ganglion cells (RGCs) in optic neuropathies such as glaucoma, which is characterized by progressive loss of vision caused by degeneration of RGCs and their axons in the optic nerve. Studies in animal models of RGC degeneration induced by ocular hypertension, optic nerve crush and axotomy show that upregulation of HSP70 expression by hyperthermia, zinc, geranyl-geranyl acetone, 17-AAG (a HSP90 inhibitor), or through transfection of retinal cells with AAV2-HSP70 effectively supports the survival of injured RGCs. RGCs survival was also stimulated by overexpression of alpha A and alpha B crystallins. These findings provide support for translating the HSP70- and alpha crystallin-based cell survival strategy into therapy to protect and rescue injured RGCs from degeneration associated with glaucomatous and other optic neuropathies.
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Affiliation(s)
- Natik Piri
- Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Brain Research Institute, University of California, Los Angeles, CA 90095, USA.
| | - Jacky M K Kwong
- Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
| | - Lei Gu
- Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
| | - Joseph Caprioli
- Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Brain Research Institute, University of California, Los Angeles, CA 90095, USA
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15
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Chidlow G, Wood JPM, Casson RJ. Expression of inducible heat shock proteins Hsp27 and Hsp70 in the visual pathway of rats subjected to various models of retinal ganglion cell injury. PLoS One 2014; 9:e114838. [PMID: 25535743 PMCID: PMC4275305 DOI: 10.1371/journal.pone.0114838] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/14/2014] [Indexed: 01/09/2023] Open
Abstract
Inducible heat shock proteins (Hsps) are upregulated in the central nervous system in response to a wide variety of injuries. Surprisingly, however, no coherent picture has emerged regarding the magnitude, duration and cellular distribution of inducible Hsps in the visual system following injury to retinal ganglion cells (RGCs). The current study sought, therefore, to achieve the following two objectives. The first aim of this study was to systematically characterise the patterns of Hsp27 and −70 expression in the retina and optic nerve in four discrete models of retinal ganglion cell (RGC) degeneration: axonal injury (ON crush), somato-dendritic injury (NMDA-induced excitotoxicity), chronic hypoperfusion (bilateral occlusion of the carotid arteris) and experimental glaucoma. The second aim was to document Hsp27 and −70 expression in the optic tract, the subcortical retinorecipient areas of the brain, and the visual cortex during Wallerian degeneration of RGC axons. Hsp27 was robustly upregulated in the retina in each injury paradigm, with the chronic models, 2VO and experimental glaucoma, displaying a more persistent Hsp27 transcriptional response than the acute models. Hsp27 expression was always associated with astrocytes and with a subset of RGCs in each of the models excluding NMDA. Hsp27 was present within astrocytes of the optic nerve/optic tract in control rats. During Wallerian degeneration, Hsp27 was upregulated in the optic nerve/optic tract and expressed de novo by astrocytes in the lateral geniculate nucleus and the stratum opticum of the superior colliculus. Conversely, the results of our study indicate Hsp70 was minimally induced in any of the models of injury, either in the retina, or in the optic nerve/optic tract, or in the subcortical, retinorecipient areas of the brain. The findings of the present study augment our understanding of the involvement of Hsp27 and Hsp70 in the response of the visual system to RGC degeneration.
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Affiliation(s)
- Glyn Chidlow
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
- * E-mail:
| | - John P. M. Wood
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
| | - Robert J. Casson
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Frome Road, Adelaide SA-5000, Australia
- Department of Ophthalmology and Visual Sciences, University of Adelaide, Frome Road, Adelaide SA-5000, Australia
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Tehrani S, Johnson EC, Cepurna WO, Morrison JC. Astrocyte processes label for filamentous actin and reorient early within the optic nerve head in a rat glaucoma model. Invest Ophthalmol Vis Sci 2014; 55:6945-52. [PMID: 25257054 DOI: 10.1167/iovs.14-14969] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine if astrocyte processes label for actin and to quantify the orientation of astrocytic processes within the optic nerve head (ONH) in a rat glaucoma model. METHODS Chronic intraocular pressure (IOP) elevation was produced by episcleral hypertonic saline injection and tissues were collected after 5 weeks. For comparison, eyes with optic nerve transection were collected at 2 weeks. Fellow eyes served as controls. Axonal degeneration in retrobulbar optic nerves was graded on a scale of 1 to 5. Optic nerve head sections (n ≥ 4 eyes per group) were colabeled with phalloidin (actin marker) and antibodies to astrocytic glial fibrillary acidic protein and aquaporin 4, or axonal tubulin βIII. Confocal microscopy and FIJI software were used to quantify the orientation of actin bundles. RESULTS Control ONHs showed stereotypically arranged actin bundles within astrocyte processes. Optic nerve head actin bundle orientation was nearly perpendicular to axons (82.9° ± 6.3° relative to axonal axis), unlike the retrobulbar optic nerve (45.4° ± 28.7°, P < 0.05). With IOP elevation, ONH actin bundle orientation became less perpendicular to axons, even in eyes with no perceivable axonal injury (i.e., 38.8° ± 15.1° in grade 1, P < 0.05 in comparison to control ONHs). With severe injury, ONH actin bundle orientation became more parallel to the axonal axis (24.1° ± 28.4°, P < 0.05 in comparison to control ONHs). Optic nerve head actin bundle orientation in transected optic nerves was unchanged. CONCLUSIONS Actin labeling identifies fine astrocyte processes within the ONH. Optic nerve head astrocyte process reorientation occurs early in response to elevated IOP.
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Affiliation(s)
- Shandiz Tehrani
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Elaine C Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - William O Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - John C Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
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17
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Tuomela A, Liu P, Puranen J, Rönkkö S, Laaksonen T, Kalesnykas G, Oksala O, Ilkka J, Laru J, Järvinen K, Hirvonen J, Peltonen L. Brinzolamide nanocrystal formulations for ophthalmic delivery: Reduction of elevated intraocular pressure in vivo. Int J Pharm 2014; 467:34-41. [DOI: 10.1016/j.ijpharm.2014.03.048] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/20/2014] [Accepted: 03/25/2014] [Indexed: 11/16/2022]
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18
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Pinach S, Burt D, Berrone E, Barutta F, Bruno G, Porta M, Perin PC, Gruden G. Retinal heat shock protein 25 in early experimental diabetes. Acta Diabetol 2013; 50:579-85. [PMID: 22068623 DOI: 10.1007/s00592-011-0346-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 10/03/2011] [Indexed: 01/29/2023]
Abstract
Diabetic retinopathy is the leading cause of blindness in adults, and oxidative stress has been pathogenically associated with retinal neurodegeneration. Cellular stresses induce expression of heat shock proteins (HSPs) and this results in cytoprotection. Our aim was to assess retinal expression of HSP25 in early experimental diabetes. Mice were rendered diabetic by streptozotocin injection. Ten weeks after diabetes onset retinal HSP25 expression were studied by real-time PCR, immunoblotting and immunohistochemistry (IHC). Expression of nitrotyrosine and Cu/Zn superoxide dismutase (SOD), was assessed by IHC and apoptosis by TUNEL. Retinal HSP25 mRNA and protein expression was significantly increased in diabetic as compared to non-diabetic animals and localised predominantly within the retinal ganglion cells (RGC) layer. This was paralleled overexpression of nitrotyrosine and SOD and enhanced apoptosis. In early experimental diabetes, HSP25 is overexpressed in the RGC layer in parallel with markers of oxidative stress and apoptosis.
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Affiliation(s)
- Silvia Pinach
- Department of Internal Medicine, University of Turin, C/so Dogliotti 14, 10126, Turin, Italy,
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19
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Janssen SF, Gorgels TGMF, Bossers K, ten Brink JB, Essing AHW, Nagtegaal M, van der Spek PJ, Jansonius NM, Bergen AAB. Gene expression and functional annotation of the human ciliary body epithelia. PLoS One 2012; 7:e44973. [PMID: 23028713 PMCID: PMC3445623 DOI: 10.1371/journal.pone.0044973] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 08/15/2012] [Indexed: 12/01/2022] Open
Abstract
Purpose The ciliary body (CB) of the human eye consists of the non-pigmented (NPE) and pigmented (PE) neuro-epithelia. We investigated the gene expression of NPE and PE, to shed light on the molecular mechanisms underlying the most important functions of the CB. We also developed molecular signatures for the NPE and PE and studied possible new clues for glaucoma. Methods We isolated NPE and PE cells from seven healthy human donor eyes using laser dissection microscopy. Next, we performed RNA isolation, amplification, labeling and hybridization against 44×k Agilent microarrays. For microarray conformations, we used a literature study, RT-PCRs, and immunohistochemical stainings. We analyzed the gene expression data with R and with the knowledge database Ingenuity. Results The gene expression profiles and functional annotations of the NPE and PE were highly similar. We found that the most important functionalities of the NPE and PE were related to developmental processes, neural nature of the tissue, endocrine and metabolic signaling, and immunological functions. In total 1576 genes differed statistically significantly between NPE and PE. From these genes, at least 3 were cell-specific for the NPE and 143 for the PE. Finally, we observed high expression in the (N)PE of 35 genes previously implicated in molecular mechanisms related to glaucoma. Conclusion Our gene expression analysis suggested that the NPE and PE of the CB were quite similar. Nonetheless, cell-type specific differences were found. The molecular machineries of the human NPE and PE are involved in a range of neuro-endocrinological, developmental and immunological functions, and perhaps glaucoma.
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Affiliation(s)
- Sarah F. Janssen
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Theo G. M. F. Gorgels
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Koen Bossers
- Laboratory for Neuroregeneration, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Jacoline B. ten Brink
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Anke H. W. Essing
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Martijn Nagtegaal
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Peter J. van der Spek
- Department of Bioinformatics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nomdo M. Jansonius
- Department of Ophthalmology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Arthur A. B. Bergen
- Department of Clinical and Molecular Ophthalmogenetics, the Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
- Department of Ophthalmology, Academic Medical Centre, Amsterdam, The Netherlands
- Department of Clinical Genetics, Academic Medical Centre, Amsterdam, The Netherlands
- * E-mail:
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20
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The molecular basis of retinal ganglion cell death in glaucoma. Prog Retin Eye Res 2012; 31:152-81. [DOI: 10.1016/j.preteyeres.2011.11.002] [Citation(s) in RCA: 565] [Impact Index Per Article: 47.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 10/28/2011] [Accepted: 11/01/2011] [Indexed: 12/14/2022]
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21
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Armstrong CL, Duffin CA, McFarland R, Vogel MW. Mechanisms of compartmental purkinje cell death and survival in the lurcher mutant mouse. THE CEREBELLUM 2012; 10:504-14. [PMID: 21104177 DOI: 10.1007/s12311-010-0231-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Lurcher mutant mouse is characterized by its ataxic gait and loss of cerebellar Purkinje cells and their afferents, granule cells and olivary neurons, during the first weeks of postnatal development. For the 50 years since its discovery, the heterozygous Lurcher mutant has served as an important model system for studying neuron-target interactions in the developing cerebellum and cerebellar function. The identification of the Lurcher (Lc) gene over 10 years ago as a gain-of-function mutation in the δ2 glutamate receptor (GluRδ2) led to extensive studies of cell death mechanisms in the Lc/+ cerebellum. The advantage of this model system is that GluRδ2(+) receptors and GluRδ2(Lc) channels are expressed predominantly in Purkinje cells, making it possible to study the effects of a well-characterized leak current in a well-defined cell type during a critical phase of neuronal development. Yet there is still controversy surrounding the mechanisms of neuronal death in Lc/+ Purkinje cells with competing hypotheses for necrotic, apoptotic, and autophagic cell death pathways as a consequence of the excitotoxic stress caused by the GluRδ2(Lc) leak current. The goal of this review is to summarize recent studies that critically test the role of various cell death pathways in Lc/+ Purkinje cell degeneration with respect to evidence for the molecular heterogeneity of Purkinje cells. We propose that the expression of putative survival factors, such as heat shock proteins, in a subset of cerebellar Purkinje cells may affect cell death pathways and account for the pattern and diverse mechanisms of Lc/+ Purkinje degeneration.
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Affiliation(s)
- Carol L Armstrong
- Department of Chemical and Biological Sciences, Mt Royal University, Calgary, AB, Canada, T3E 6K6
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22
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Chidlow G, Daymon M, Wood JPM, Casson RJ. Localization of a wide-ranging panel of antigens in the rat retina by immunohistochemistry: comparison of Davidson's solution and formalin as fixatives. J Histochem Cytochem 2011; 59:884-98. [PMID: 21832149 DOI: 10.1369/0022155411418115] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The preferred fixative for whole eyes is Davidson's solution, which provides optimal tissue preservation while avoiding retinal detachment. Hitherto, the compatibility of Davidson's solution with immunohistochemistry has been largely untested. The goal of the present study was to compare the immunolabeling patterns of a wide-ranging panel of commercially available, previously validated antibodies in formalin- and Davidson's-fixed retinas. Immunohistochemistry was performed in normal pigmented rat eyes and, to facilitate localization of inducible proteins, eyes injected with the bacterial toxin lipopolysaccharide or subjected to laser-induced photoreceptor damage. Specificity of labeling was judged by the morphology and distribution of immunopositive cells, by the absence of signal in appropriate controls, and by comparison with expected staining patterns. Retinas fixed in formalin displayed only adequate morphological integrity but were highly compatible with all 39 antibodies evaluated. Retinas fixed in Davidson's solution displayed morphological integrity superior to those fixed in formalin. Generally, the cellular and subcellular patterns and intensities of immunoreactivities obtained with each fixative were identical; however, Davidson's fixative was less compatible with certain antibodies, such as the neurotransmitter γ-aminobutyric acid, the microglial marker iba1, the macroglial stress protein nestin, and the small heat shock proteins Hsp27 and αB-crystallin, shortfalls that somewhat temper enthusiasm concerning its use.
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Affiliation(s)
- Glyn Chidlow
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Adelaide, Australia.
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23
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Sherpa T, Hunter SS, Frey RA, Robison BD, Stenkamp DL. Retinal proliferation response in the buphthalmic zebrafish, bugeye. Exp Eye Res 2011; 93:424-36. [PMID: 21723280 DOI: 10.1016/j.exer.2011.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 05/23/2011] [Accepted: 06/05/2011] [Indexed: 10/18/2022]
Abstract
The zebrafish retina regenerates in response to acute retinal lesions, replacing damaged neurons with new neurons. In this study we test the hypothesis that chronic stress to inner retinal neurons also triggers a retinal regeneration response in the bugeye zebrafish. Mutations in the lrp2 gene in zebrafish are associated with a progressive eye phenotype (bugeye) that models several risk factors for human glaucoma including buphthalmos (enlarged eyes), elevated intraocular pressure (IOP), and upregulation of genes related to retinal ganglion cell pathology. The retinas of adult bugeye zebrafish showed high rates of ongoing proliferation which resulted in the production of a small number of new retinal neurons, particularly photoreceptors. A marker of mechanical cell stress, Hsp27, was strongly expressed in inner retinal neurons and glia of bugeye retinas. The more enlarged eyes of individual bugeye zebrafish showed disrupted retinal lamination, and a persistent reduced density of neurons in the ganglion cell layer (GCL), although total numbers of GCL neurons were higher than in control eyes. Despite the presence of a proliferative response to damage, the adult bugeye zebrafish remained behaviorally blind. These findings suggest the existence of an unsuccessful regenerative response to a persistent pathological condition in the bugeye zebrafish.
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Affiliation(s)
- Tshering Sherpa
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844-3051, USA
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24
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Chidlow G, Ebneter A, Wood JPM, Casson RJ. The optic nerve head is the site of axonal transport disruption, axonal cytoskeleton damage and putative axonal regeneration failure in a rat model of glaucoma. Acta Neuropathol 2011; 121:737-51. [PMID: 21311901 PMCID: PMC3098991 DOI: 10.1007/s00401-011-0807-1] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/27/2011] [Accepted: 01/29/2011] [Indexed: 02/02/2023]
Abstract
The neurodegenerative disease glaucoma is characterised by the progressive death of retinal ganglion cells (RGCs) and structural damage to the optic nerve (ON). New insights have been gained into the pathogenesis of glaucoma through the use of rodent models; however, a coherent picture of the early pathology remains elusive. Here, we use a validated, experimentally induced rat glaucoma model to address fundamental issues relating to the spatio-temporal pattern of RGC injury. The earliest indication of RGC damage was accumulation of proteins, transported by orthograde fast axonal transport within axons in the optic nerve head (ONH), which occurred as soon as 8 h after induction of glaucoma and was maximal by 24 h. Axonal cytoskeletal abnormalities were first observed in the ONH at 24 h. In contrast to the ONH, no axonal cytoskeletal damage was detected in the entire myelinated ON and tract until 3 days, with progressively greater damage at later time points. Likewise, down-regulation of RGC-specific mRNAs, which are sensitive indicators of RGC viability, occurred subsequent to axonal changes at the ONH and later than in retinas subjected to NMDA-induced somatic excitotoxicity. After 1 week, surviving, but injured, RGCs had initiated a regenerative-like response, as delineated by Gap43 immunolabelling, in a response similar to that seen after ON crush. The data presented here provide robust support for the hypothesis that the ONH is the pivotal site of RGC injury following moderate elevation of IOP, with the resulting anterograde degeneration of axons and retrograde injury and death of somas.
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Affiliation(s)
- Glyn Chidlow
- Ophthalmic Research Laboratories, South Australian Institute of Ophthalmology, Hanson Institute Centre for Neurological Diseases, Adelaide, SA, Australia.
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25
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Morrison JC, Cepurna Ying Guo WO, Johnson EC. Pathophysiology of human glaucomatous optic nerve damage: insights from rodent models of glaucoma. Exp Eye Res 2010; 93:156-64. [PMID: 20708000 DOI: 10.1016/j.exer.2010.08.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Revised: 07/28/2010] [Accepted: 08/03/2010] [Indexed: 10/19/2022]
Abstract
Understanding mechanisms of glaucomatous optic nerve damage is essential for developing effective therapies to augment conventional pressure-lowering treatments. This requires that we understand not only the physical forces in play, but the cellular responses that translate these forces into axonal injury. The former are best understood by using primate models, in which a well-developed lamina cribrosa, peripapillary sclera and blood supply are most like that of the human optic nerve head. However, determining cellular responses to elevated intraocular pressure (IOP) and relating their contribution to axonal injury require cell biology techniques, using animals in numbers sufficient to perform reliable statistical analyses and draw meaningful conclusions. Over the years, models of chronically elevated IOP in laboratory rats and mice have proven increasingly useful for these purposes. While lacking a distinct collagenous lamina cribrosa, the rodent optic nerve head (ONH) possesses a cellular arrangement of astrocytes, or glial lamina, that ultrastructurally closely resembles that of the primate. Using these tools, major insights have been gained into ONH and the retinal cellular responses to elevated IOP that, in time, can be applied to the primate model and, ultimately, human glaucoma.
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Affiliation(s)
- John C Morrison
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, CERES, 3375 SW Terwilliger Bvld, Portland, OR 97239, USA.
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26
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O'Reilly AM, Currie RW, Clarke DB. HspB1 (Hsp 27) Expression and Neuroprotection in the Retina. Mol Neurobiol 2010; 42:124-32. [PMID: 20514530 DOI: 10.1007/s12035-010-8143-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 05/12/2010] [Indexed: 12/14/2022]
Affiliation(s)
- Amanda M O'Reilly
- Department of Anatomy & Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, NS, B3H 1X5, Canada
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27
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Hypoxia inducible factor-1α (HIF-1α) and some HIF-1 target genes are elevated in experimental glaucoma. J Mol Neurosci 2010; 42:183-91. [PMID: 20237864 DOI: 10.1007/s12031-010-9343-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Accepted: 02/17/2010] [Indexed: 10/19/2022]
Abstract
Low levels of hypoxia have been suggested to be a mechanism of retinal damage in glaucoma. To test the hypothesis that the activation of the hypoxia-responsive transcription factor hypoxia inducible factor-1alpha (HIF-1alpha) is involved in the pathophysiology of glaucoma, we used a rat model of glaucoma to study (1) HIF-1alpha retinal protein levels by immunoblot analysis, (2) cellular localization of HIF-1alpha in the retina by immunohistochemistry, and (3) expression of retinal HIF-1 gene targets by quantitative real-time polymerase chain reaction. Glaucoma was unilaterally induced in rats by injecting hypertonic saline in episcleral veins. We find that HIF-1alpha protein was increased in the retina following elevation of intraocular pressure, specifically in Müller glia and astrocytes but not in activated microglia. Eight established HIF-1 target genes were measured in experimental glaucoma. Retinal Epo, Flt-1, Hsp-27, Pai-1, and Vegfa mRNA levels were increased and Et-1, Igf2, and Tgfbeta3 levels were decreased in the glaucomatous retinas. Thus, the increase in HIF-1alpha levels in Müller glia and astrocytes is accompanied by a marked up regulation of some, but not all, HIF-1 transcriptional targets. These data support the hypothesis that HIF-1alpha becomes transcriptionally active in astrocytes and Müller cells but not microglia or neurons in glaucoma, arguing against a global hypoxia stimulus to the retina.
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28
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Kalesnykas G, Tuulos T, Uusitalo H, Jolkkonen J. Neurodegeneration and cellular stress in the retina and optic nerve in rat cerebral ischemia and hypoperfusion models. Neuroscience 2008; 155:937-47. [DOI: 10.1016/j.neuroscience.2008.06.038] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 06/12/2008] [Accepted: 06/12/2008] [Indexed: 11/30/2022]
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