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Cameron EG, Nahmou M, Toth AB, Heo L, Tanasa B, Dalal R, Yan W, Nallagatla P, Xia X, Hay S, Knasel C, Stiles TL, Douglas C, Atkins M, Sun C, Ashouri M, Bian M, Chang KC, Russano K, Shah S, Woodworth MB, Galvao J, Nair RV, Kapiloff MS, Goldberg JL. A molecular switch for neuroprotective astrocyte reactivity. Nature 2024; 626:574-582. [PMID: 38086421 DOI: 10.1038/s41586-023-06935-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/05/2023] [Indexed: 01/27/2024]
Abstract
The intrinsic mechanisms that regulate neurotoxic versus neuroprotective astrocyte phenotypes and their effects on central nervous system degeneration and repair remain poorly understood. Here we show that injured white matter astrocytes differentiate into two distinct C3-positive and C3-negative reactive populations, previously simplified as neurotoxic (A1) and neuroprotective (A2)1,2, which can be further subdivided into unique subpopulations defined by proliferation and differential gene expression signatures. We find the balance of neurotoxic versus neuroprotective astrocytes is regulated by discrete pools of compartmented cyclic adenosine monophosphate derived from soluble adenylyl cyclase and show that proliferating neuroprotective astrocytes inhibit microglial activation and downstream neurotoxic astrocyte differentiation to promote retinal ganglion cell survival. Finally, we report a new, therapeutically tractable viral vector to specifically target optic nerve head astrocytes and show that raising nuclear or depleting cytoplasmic cyclic AMP in reactive astrocytes inhibits deleterious microglial or macrophage cell activation and promotes retinal ganglion cell survival after optic nerve injury. Thus, soluble adenylyl cyclase and compartmented, nuclear- and cytoplasmic-localized cyclic adenosine monophosphate in reactive astrocytes act as a molecular switch for neuroprotective astrocyte reactivity that can be targeted to inhibit microglial activation and neurotoxic astrocyte differentiation to therapeutic effect. These data expand on and define new reactive astrocyte subtypes and represent a step towards the development of gliotherapeutics for the treatment of glaucoma and other optic neuropathies.
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Affiliation(s)
- Evan G Cameron
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA.
| | - Michael Nahmou
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Anna B Toth
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Lyong Heo
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Palo Alto, CA, USA
| | - Bogdan Tanasa
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Roopa Dalal
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Wenjun Yan
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Pratima Nallagatla
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Palo Alto, CA, USA
| | - Xin Xia
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Sarah Hay
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Cara Knasel
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | | | | | - Melissa Atkins
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Catalina Sun
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Masoumeh Ashouri
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Minjuan Bian
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Kun-Che Chang
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Kristina Russano
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Sahil Shah
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
- University of California, San Diego, La Jolla, CA, USA
| | - Mollie B Woodworth
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Joana Galvao
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Ramesh V Nair
- Stanford Center for Genomics and Personalized Medicine, Stanford University, Palo Alto, CA, USA
| | - Michael S Kapiloff
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
- Department of Medicine and Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Jeffrey L Goldberg
- Mary M. and Sash A. Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA.
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Shah SH, Schiapparelli LM, Ma Y, Yokota S, Atkins M, Xia X, Cameron EG, Huang T, Saturday S, Sun CB, Knasel C, Blackshaw S, Yates Iii JR, Cline HT, Goldberg JL. Quantitative transportomics identifies Kif5a as a major regulator of neurodegeneration. eLife 2022; 11:68148. [PMID: 35259089 PMCID: PMC8947766 DOI: 10.7554/elife.68148] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/07/2022] [Indexed: 11/29/2022] Open
Abstract
Many neurons in the adult central nervous system, including retinal ganglion cells (RGCs), degenerate and die after injury. Early axon protein and organelle trafficking failure is a key component in many neurodegenerative disorders yet changes to axoplasmic transport in disease models have not been quantified. We analyzed early changes in the protein ‘transportome’ from RGC somas to their axons after optic nerve injury and identified transport failure of an anterograde motor protein Kif5a early in RGC degeneration. We demonstrated that manipulating Kif5a expression affects anterograde mitochondrial trafficking in RGCs and characterized axon transport in Kif5a knockout mice to identify proteins whose axon localization was Kif5a-dependent. Finally, we found that knockout of Kif5a in RGCs resulted in progressive RGC degeneration in the absence of injury. Together with expression data localizing Kif5a to human RGCs, these data identify Kif5a transport failure as a cause of RGC neurodegeneration and point to a mechanism for future therapeutics.
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Affiliation(s)
- Sahil H Shah
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | | | - Yuanhui Ma
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, United States
| | - Satoshi Yokota
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Melissa Atkins
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Xin Xia
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Evan G Cameron
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Thanh Huang
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Sarah Saturday
- Neuroscience Department, The Scripps Research Institute, La Jolla, United States
| | - Catalin B Sun
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Cara Knasel
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
| | - John R Yates Iii
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, United States
| | - Hollis T Cline
- Neuroscience Department, The Scripps Research Institute, La Jolla, United States
| | - Jeffrey L Goldberg
- Byers Eye Institute and Spencer Center for Vision Research, Stanford University, Palo Alto, United States
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Xia X, Yu CY, Bian M, Sun CB, Tanasa B, Chang KC, Bruffett DM, Thakur H, Shah SH, Knasel C, Cameron EG, Kapiloff MS, Goldberg JL. MEF2 transcription factors differentially contribute to retinal ganglion cell loss after optic nerve injury. PLoS One 2020; 15:e0242884. [PMID: 33315889 PMCID: PMC7735573 DOI: 10.1371/journal.pone.0242884] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
Loss of retinal ganglion cells (RGCs) in optic neuropathies results in permanent partial or complete blindness. Myocyte enhancer factor 2 (MEF2) transcription factors have been shown to play a pivotal role in neuronal systems, and in particular MEF2A knockout was shown to enhance RGC survival after optic nerve crush injury. Here we expanded these prior data to study bi-allelic, tri-allelic and heterozygous allele deletion. We observed that deletion of all MEF2A, MEF2C, and MEF2D alleles had no effect on RGC survival during development. Our extended experiments suggest that the majority of the neuroprotective effect was conferred by complete deletion of MEF2A but that MEF2D knockout, although not sufficient to increase RGC survival on its own, increased the positive effect of MEF2A knockout. Conversely, MEF2A over-expression in wildtype mice worsened RGC survival after optic nerve crush. Interestingly, MEF2 transcription factors are regulated by post-translational modification, including by calcineurin-catalyzed dephosphorylation of MEF2A Ser-408 known to increase MEF2A-dependent transactivation in neurons. However, neither phospho-mimetic nor phospho-ablative mutation of MEF2A Ser-408 affected the ability of MEF2A to promote RGC death in vivo after optic nerve injury. Together these findings demonstrate that MEF2 gene expression opposes RGC survival following axon injury in a complex hierarchy, and further support the hypothesis that loss of or interference with MEF2A expression might be beneficial for RGC neuroprotection in diseases such as glaucoma and other optic neuropathies.
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Affiliation(s)
- Xin Xia
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Caroline Y. Yu
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Minjuan Bian
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Catalina B. Sun
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Bogdan Tanasa
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Kun-Che Chang
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Dawn M. Bruffett
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Hrishikesh Thakur
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Sahil H. Shah
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Cara Knasel
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Evan G. Cameron
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
| | - Michael S. Kapiloff
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- Department of Medicine and Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- * E-mail: (MSK); (JLG)
| | - Jeffrey L. Goldberg
- Mary M. and Sash A. Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, United States of America
- * E-mail: (MSK); (JLG)
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Valdez-Lopez JC, Petr ST, Donohue MP, Bailey RJ, Gebreeziabher M, Cameron EG, Wolf JB, Szalai VA, Robinson PR. The C-Terminus and Third Cytoplasmic Loop Cooperatively Activate Mouse Melanopsin Phototransduction. Biophys J 2020; 119:389-401. [PMID: 32621866 PMCID: PMC7376183 DOI: 10.1016/j.bpj.2020.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/28/2020] [Accepted: 06/10/2020] [Indexed: 11/30/2022] Open
Abstract
Melanopsin, an atypical vertebrate visual pigment, mediates non-image-forming light responses including circadian photoentrainment and pupillary light reflexes and contrast detection for image formation. Melanopsin-expressing intrinsically photosensitive retinal ganglion cells are characterized by sluggish activation and deactivation of their light responses. The molecular determinants of mouse melanopsin's deactivation have been characterized (i.e., C-terminal phosphorylation and β-arrestin binding), but a detailed analysis of melanopsin's activation is lacking. We propose that an extended third cytoplasmic loop is adjacent to the proximal C-terminal region of mouse melanopsin in the inactive conformation, which is stabilized by the ionic interaction of these two regions. This model is supported by site-directed spin labeling and electron paramagnetic resonance spectroscopy of melanopsin, the results of which suggests a high degree of steric freedom at the third cytoplasmic loop, which is increased upon C-terminus truncation, supporting the idea that these two regions are close in three-dimensional space in wild-type melanopsin. To test for a functionally critical C-terminal conformation, calcium imaging of melanopsin mutants including a proximal C-terminus truncation (at residue 365) and proline mutation of this proximal region (H377P, L380P, Y382P) delayed melanopsin's activation rate. Mutation of all potential phosphorylation sites, including a highly conserved tyrosine residue (Y382), into alanines also delayed the activation rate. A comparison of mouse melanopsin with armadillo melanopsin-which has substitutions of various potential phosphorylation sites and a substitution of the conserved tyrosine-indicates that substitution of these potential phosphorylation sites and the tyrosine residue result in dramatically slower activation kinetics, a finding that also supports the role of phosphorylation in signaling activation. We therefore propose that melanopsin's C-terminus is proximal to intracellular loop 3, and C-terminal phosphorylation permits the ionic interaction between these two regions, thus forming a stable structural conformation that is critical for initiating G-protein signaling.
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Affiliation(s)
- Juan C Valdez-Lopez
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Stephen T Petr
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Matthew P Donohue
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland; Maryland NanoCenter, University of Maryland College Park, College Park, Maryland
| | - Robin J Bailey
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Meheret Gebreeziabher
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Evan G Cameron
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Julia B Wolf
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland
| | - Veronika A Szalai
- Center for Nanoscale and Technology, National Institutes of Standards and Technology, Gaithersburg, Maryland
| | - Phyllis R Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, Maryland.
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Venugopalan P, Cameron EG, Zhang X, Nahmou M, Muller KJ, Goldberg JL. Physiologic maturation is both extrinsically and intrinsically regulated in progenitor-derived neurons. Sci Rep 2020; 10:2337. [PMID: 32047174 PMCID: PMC7012889 DOI: 10.1038/s41598-020-58120-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/03/2020] [Indexed: 12/15/2022] Open
Abstract
During development, newly-differentiated neurons undergo several morphological and physiological changes to become functional, mature neurons. Physiologic maturation of neuronal cells derived from isolated stem or progenitor cells may provide insight into maturation in vivo but is not well studied. As a step towards understanding how neuronal maturation is regulated, we studied the developmental switch of response to the neurotransmitter GABA, from excitatory depolarization to inhibitory hyperpolarization. We compared acutely isolated retinal ganglion cells (RGCs) at various developmental stages and RGCs differentiated in vitro from embryonic retinal progenitors for the effects of aging and, independently, of retinal environment age on their GABAA receptor (GABAAR) responses, elicited by muscimol. We found that neurons generated in vitro from progenitors exhibited depolarizing, immature GABA responses, like those of early postnatal RGCs. As progenitor-derived neurons aged from 1 to 3 weeks, their GABA responses matured. Interestingly, signals secreted by the early postnatal retina suppressed acquisition of mature GABA responses. This suppression was not associated with changes in expression of GABAAR or of the chloride co-transporter KCC2, but rather with inhibition of KCC2 dimerization in differentiating neurons. Taken together, these data indicate GABA response maturation depends on release of inhibition by developmentally regulated diffusible signals from the retina.
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Affiliation(s)
- Praseeda Venugopalan
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Evan G Cameron
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Xiong Zhang
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA
| | - Michael Nahmou
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA
| | - Kenneth J Muller
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Department of Physiology & Biophysics, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.
| | - Jeffrey L Goldberg
- Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
- Shiley Eye Institute, University of California, San Diego, CA, 92093, USA.
- Byers Eye Institute, Stanford University, Stanford, CA, 94303, USA.
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Cameron EG, Xia X, Galvao J, Ashouri M, Kapiloff MS, Goldberg JL. Optic Nerve Crush in Mice to Study Retinal Ganglion Cell Survival and Regeneration. Bio Protoc 2020; 10:e3559. [PMID: 32368566 DOI: 10.21769/bioprotoc.3559] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In diseases such as glaucoma, the failure of retinal ganglion cell (RGC) neurons to survive or regenerate their optic nerve axons underlies partial and, in some cases, complete vision loss. Optic nerve crush (ONC) serves as a useful model not only of traumatic optic neuropathy but also of glaucomatous injury, as it similarly induces RGC cell death and degeneration. Intravitreal injection of adeno-associated virus serotype 2 (AAV2) has been shown to specifically and efficiently transduce RGCs in vivo and has thus been proposed as an effective means of gene delivery for the treatment of glaucoma. Indeed, we and others routinely use AAV2 to study the mechanisms that promote neuroprotection and axon regeneration in RGCs following ONC. Herein, we describe a step-by-step protocol to assay RGC survival and regeneration in mice following AAV2-mediated transduction and ONC injury including 1) intravitreal injection of AAV2 viral vectors, 2) optic nerve crush, 3) cholera-toxin B (CTB) labeling of regenerating axons, 4) optic nerve clearing, 5) flat mount retina immunostaining, and 6) quantification of RGC survival and regeneration. In addition to providing all the materials and procedural details necessary to execute this protocol, we highlight its advantages over other similar published approaches and include useful tips to ensure its faithful reproduction in any modern laboratory.
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Affiliation(s)
- Evan G Cameron
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA
| | - Xin Xia
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA
| | - Joana Galvao
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA
| | - Masoumeh Ashouri
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA
| | - Michael S Kapiloff
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA.,Department of Medicine and Stanford Cardiovascular Institute, Stanford University School of Medicine, Palo Alto, California 94034, USA
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Byers Eye Institute, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, California 94034, USA
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Chang KC, Sun C, Cameron EG, Madaan A, Wu S, Xia X, Zhang X, Tenerelli K, Nahmou M, Knasel CM, Russano KR, Hertz J, Goldberg JL. Opposing Effects of Growth and Differentiation Factors in Cell-Fate Specification. Curr Biol 2019; 29:1963-1975.e5. [PMID: 31155355 PMCID: PMC6581615 DOI: 10.1016/j.cub.2019.05.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/15/2019] [Accepted: 05/01/2019] [Indexed: 12/22/2022]
Abstract
Following ocular trauma or in diseases such as glaucoma, irreversible vision loss is due to the death of retinal ganglion cell (RGC) neurons. Although strategies to replace these lost cells include stem cell replacement therapy, few differentiated stem cells turn into RGC-like neurons. Understanding the regulatory mechanisms of RGC differentiation in vivo may improve outcomes of cell transplantation by directing the fate of undifferentiated cells toward mature RGCs. Here, we report a new mechanism by which growth and differentiation factor-15 (GDF-15), a ligand in the transforming growth factor-beta (TGF-β) superfamily, strongly promotes RGC differentiation in the developing retina in vivo in rodent retinal progenitor cells (RPCs) and in human embryonic stem cells (hESCs). This effect is in direct contrast to the closely related ligand GDF-11, which suppresses RGC-fate specification. We find these opposing effects are due in part to GDF-15's ability to specifically suppress Smad-2, but not Smad-1, signaling induced by GDF-11, which can be recapitulated by pharmacologic or genetic blockade of Smad-2 in vivo to increase RGC specification. No other retinal cell types were affected by GDF-11 knockout, but a slight reduction in photoreceptor cells was observed by GDF-15 knockout in the developing retina in vivo. These data define a novel regulatory mechanism of GDFs' opposing effects and their relevance in RGC differentiation and suggest a potential approach for advancing ESC-to-RGC cell-based replacement therapies.
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Affiliation(s)
- Kun-Che Chang
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA.
| | - Catalina Sun
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Evan G Cameron
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Ankush Madaan
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Suqian Wu
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA; Eye, Ear, Nose, & Throat Hospital, Department of Ophthalmology & Visual Science, Fudan University, 200031 Shanghai, China
| | - Xin Xia
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Xiong Zhang
- Shiley Eye Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Kevin Tenerelli
- Shiley Eye Center, University of California San Diego, La Jolla, CA 92093, USA
| | - Michael Nahmou
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Cara M Knasel
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA
| | - Kristina R Russano
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA; Shiley Eye Center, University of California San Diego, La Jolla, CA 92093, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA
| | - Jonathan Hertz
- Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, School of Medicine, Stanford University, Palo Alto, CA 94304, USA; Shiley Eye Center, University of California San Diego, La Jolla, CA 92093, USA; Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA
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Affiliation(s)
- Evan G Cameron
- Byers Eye Institute, Stanford University, Palo Alto, CA, USA
| | - Michael S Kapiloff
- Department of Pediatrics and Medicine, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, USA
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9
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Affiliation(s)
- Evan G Cameron
- Department of Ophthalmology, Stanford University, Stanford, CA 94303, USA.
| | - Jeffrey L Goldberg
- Department of Ophthalmology, Stanford University, Stanford, CA 94303, USA
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10
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Wang Y, Cameron EG, Li J, Stiles TL, Kritzer MD, Lodhavia R, Hertz J, Nguyen T, Kapiloff MS, Goldberg JL. Muscle A-Kinase Anchoring Protein-α is an Injury-Specific Signaling Scaffold Required for Neurotrophic- and Cyclic Adenosine Monophosphate-Mediated Survival. EBioMedicine 2015; 2:1880-7. [PMID: 26844267 PMCID: PMC4703706 DOI: 10.1016/j.ebiom.2015.10.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 10/17/2015] [Accepted: 10/22/2015] [Indexed: 12/11/2022] Open
Abstract
Neurotrophic factor and cAMP-dependent signaling promote the survival and neurite outgrowth of retinal ganglion cells (RGCs) after injury. However, the mechanisms conferring neuroprotection and neuroregeneration downstream to these signals are unclear. We now reveal that the scaffold protein muscle A-kinase anchoring protein-α (mAKAPα) is required for the survival and axon growth of cultured primary RGCs. Although genetic deletion of mAKAPα early in prenatal RGC development did not affect RGC survival into adulthood, nor promoted the death of RGCs in the uninjured adult retina, loss of mAKAPα in the adult increased RGC death after optic nerve crush. Importantly, mAKAPα was required for the neuroprotective effects of brain-derived neurotrophic factor and cyclic adenosine-monophosphate (cAMP) after injury. These results identify mAKAPα as a scaffold for signaling in the stressed neuron that is required for RGC neuroprotection after optic nerve injury. mAKAPα is a stress-specific mediator of RGC survival. mAKAP deletion does not affect RGC survival in development or in the uninjured adult retina. mAKAP is downregulated after optic nerve injury, and its further deletion exacerbates RGC death. mAKAP deletion suppresses the neuroprotective effects of cAMP and BDNF after injury.
After injury or in degenerative diseases, neurons of the central nervous system (CNS) fail to regenerate and often die partly due to a lack of pro-survival, trophic signaling. Better understanding of such signaling is important for the development of therapies that enhance survival and regeneration of neurons after injury. Here we identify a critical regulator of such signaling, mAKAPα, a scaffold protein that coordinates pro-survival signaling to enhance survival and regeneration in CNS neurons after injury. The neuroprotective role of mAKAPα will likely lead to further future insights into the detailed nature of survival signaling in adult neurons.
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Affiliation(s)
- Yan Wang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States; Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Evan G Cameron
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States; Byers Eye Institute, Stanford University, Palo Alto, CA 94303, United States
| | - Jinliang Li
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Travis L Stiles
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Michael D Kritzer
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Rahul Lodhavia
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Jonathan Hertz
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States
| | - Tu Nguyen
- Department of Ophthalmology, University of California, San Diego, CA 92093, United States
| | - Michael S Kapiloff
- Department of Pediatrics, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States; Department of Medicine, Interdisciplinary Stem Cell Institute, Leonard M. Miller School of Medicine, University of Miami, Miami, FL, 33136, United States
| | - Jeffrey L Goldberg
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, United States; Department of Ophthalmology, University of California, San Diego, CA 92093, United States; Byers Eye Institute, Stanford University, Palo Alto, CA 94303, United States
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11
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Abstract
In mammals, the expression of the unusual visual pigment, melanopsin, is restricted to a small subset of intrinsically photosensitive retinal ganglion cells (ipRGCs), whose signaling regulate numerous non-visual functions including sleep, circadian photoentrainment and pupillary constriction. IpRGCs exhibit attenuated electrical responses following sequential and prolonged light exposures indicative of an adaptational response. The molecular mechanisms underlying deactivation and adaptation in ipRGCs however, have yet to be fully elucidated. The role of melanopsin phosphorylation and β-arrestin binding in this adaptive process is suggested by the phosphorylation-dependent reduction of melanopsin signaling in vitro and the ubiquitous expression of β-arrestin in the retina. These observations, along with the conspicuous absence of visual arrestin in ipRGCs, suggest that a β-arrestin terminates melanopsin signaling. Here, we describe a light- and phosphorylation- dependent reduction in melanopsin signaling mediated by both β-arrestin 1 and β-arrestin 2. Using an in vitro calcium imaging assay, we demonstrate that increasing the cellular concentration of β-arrestin 1 and β-arrestin 2 significantly increases the rate of deactivation of light-activated melanopsin in HEK293 cells. Furthermore, we show that this response is dependent on melanopsin carboxyl-tail phosphorylation. Crosslinking and co-immunoprecipitation experiments confirm β-arrestin 1 and β-arrestin 2 bind to melanopsin in a light- and phosphorylation- dependent manner. These data are further supported by proximity ligation assays (PLA), which demonstrate a melanopsin/β-arrestin interaction in HEK293 cells and ipRGCs. Together, these results suggest that melanopsin signaling is terminated in a light- and phosphorylation-dependent manner through the binding of a β-arrestin within the retina.
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Affiliation(s)
- Evan G. Cameron
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
| | - Phyllis R. Robinson
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, Maryland, United States of America
- * E-mail:
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12
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Porter ML, Kingston ACN, McCready R, Cameron EG, Hofmann CM, Suarez L, Olsen GH, Cronin TW, Robinson PR. Characterization of visual pigments, oil droplets, lens and cornea in the whooping crane Grus americana. ACTA ACUST UNITED AC 2014; 217:3883-90. [PMID: 25267845 DOI: 10.1242/jeb.108456] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Vision has been investigated in many species of birds, but few studies have considered the visual systems of large birds and the particular implications of large eyes and long-life spans on visual system capabilities. To address these issues we investigated the visual system of the whooping crane Grus americana (Gruiformes, Gruidae), which is one of only two North American crane species. It is a large, long-lived bird in which UV sensitivity might be reduced by chromatic aberration and entrance of UV radiation into the eye could be detrimental to retinal tissues. To investigate the whooping crane visual system we used microspectrophotometry to determine the absorbance spectra of retinal oil droplets and to investigate whether the ocular media (i.e. the lens and cornea) absorb UV radiation. In vitro expression and reconstitution was used to determine the absorbance spectra of rod and cone visual pigments. The rod visual pigments had wavelengths of peak absorbance (λmax) at 500 nm, whereas the cone visual pigment λmax values were determined to be 404 nm (SWS1), 450 nm (SWS2), 499 nm (RH2) and 561 nm (LWS), similar to other characterized bird visual pigment absorbance values. The oil droplet cut-off wavelength (λcut) values similarly fell within ranges recorded in other avian species: 576 nm (R-type), 522 nm (Y-type), 506 nm (P-type) and 448 nm (C-type). We confirm that G. americana has a violet-sensitive visual system; however, as a consequence of the λmax of the SWS1 visual pigment (404 nm), it might also have some UV sensitivity.
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Affiliation(s)
- Megan L Porter
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA
| | - Alexandra C N Kingston
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Robert McCready
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Evan G Cameron
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Christopher M Hofmann
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Lauren Suarez
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Glenn H Olsen
- USGS Pautuxent Wildlife Research Center, Laurel, MD 20708, USA
| | - Thomas W Cronin
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Phyllis R Robinson
- Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA
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13
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Blasic JR, Matos-Cruz V, Ujla D, Cameron EG, Hattar S, Halpern ME, Robinson PR. Identification of critical phosphorylation sites on the carboxy tail of melanopsin. Biochemistry 2014; 53:2644-9. [PMID: 24678795 PMCID: PMC4010260 DOI: 10.1021/bi401724r] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
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Light-activated
opsins undergo carboxy-terminal phosphorylation,
which contributes to the deactivation of their photoresponse. The
photopigment melanopsin possesses an unusually long carboxy tail containing
37 serine and threonine sites that are potential sites for phosphorylation
by a G-protein dependent kinase (GRK). Here, we show that a small
cluster of six to seven sites is sufficient for deactivation of light-activated
mouse melanopsin. Surprisingly, these sites are distinct from those
that regulate deactivation of rhodopsin. In zebrafish, there are five
different melanopsin genes that encode proteins with distinct carboxy-terminal
domains. Naturally occurring changes in the same cluster of phosphorylatable
amino acids provides diversity in the deactivation kinetics of the
zebrafish proteins. These results suggest that variation in phosphorylation
sites provides flexibility in the duration and kinetics of melanopsin-mediated
light responses.
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Affiliation(s)
- Joseph R Blasic
- Department of Biological Sciences, University of Maryland, Baltimore County , Baltimore, Maryland 21250, United States
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14
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Abstract
Opsin proteins are essential molecules in mediating the ability of animals to detect and use light for diverse biological functions. Therefore, understanding the evolutionary history of opsins is key to understanding the evolution of light detection and photoreception in animals. As genomic data have appeared and rapidly expanded in quantity, it has become possible to analyse opsins that functionally and histologically are less well characterized, and thus to examine opsin evolution strictly from a genetic perspective. We have incorporated these new data into a large-scale, genome-based analysis of opsin evolution. We use an extensive phylogeny of currently known opsin sequence diversity as a foundation for examining the evolutionary distributions of key functional features within the opsin clade. This new analysis illustrates the lability of opsin protein-expression patterns, site-specific functionality (i.e. counterion position) and G-protein binding interactions. Further, it demonstrates the limitations of current model organisms, and highlights the need for further characterization of many of the opsin sequence groups with unknown function.
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Affiliation(s)
- Megan L Porter
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore, MD 21250, USA.
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15
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Joshi RC, De A, Cameron EG. A comparative study of a new alpha-adrenoceptor agonist, guanfacine and alpha-methyldopa in the treatment of hypertension. Br J Clin Pract 1984; 38:66-7, 71. [PMID: 6142723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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16
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Chazan BI, Old JM, Venkataraman G, Snape J, Cameron EG. A beta blocker-thiazide combination in the treatment of hypertension in diabetics. Br J Clin Pract 1981; 35:393-8. [PMID: 7030375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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17
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Blowers AJ, Cameron EG, Lawrence ER. Effervescent ergotamine tartrate (Effergot) in the treatment of the acute migraine attack. Br J Clin Pract 1981; 35:188-190. [PMID: 6794589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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18
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Cameron EG, Crowder D. Viskaldix in the treatment of essential hypertension. A study on hospital out-patients. Practitioner 1981; 225:581-5. [PMID: 7279846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Abstract
A large, open, multi-centre study was carried out in general practice to evaluate the effectiveness and tolerance of a combination of 10 mg pindolol plus 5 mg clopamide, in single tablet form, in the treatment of patients with essential hypertension. Computer analysis of the records of 8989 patients who completed the 8-weeks' study period showed that treatment with the combination product, in a dosage of 1 tablet daily in 83% of the patients, resulted in excellent blood pressure control in the majority (75%) of cases, irrespective of age or previous antihypertensive treatment, and was particularly effective in those with mild to moderate hypertension who had previously not received any therapy. Side-effects were generally not troublesome and only 8.3% of patients stopped treatment for this reason. The most commonly reported side-effects were dizziness, nausea, tiredness and headache.
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