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Rudy MA, Watkins TA. A lead role for a "secondary" axonal injury response. Neural Regen Res 2025; 20:469-470. [PMID: 38819051 PMCID: PMC11317944 DOI: 10.4103/nrr.nrr-d-23-02070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/12/2024] [Accepted: 03/23/2024] [Indexed: 06/01/2024] Open
Affiliation(s)
- Melissa A. Rudy
- Division of Neuroimmunology and Glial Biology, Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
- Development, Disease Models, and Therapeutics Graduate Program, Baylor College of Medicine, Houston, TX, USA
| | - Trent A. Watkins
- Division of Neuroimmunology and Glial Biology, Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
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2
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Zhang X, Thomas GM. Recruitment, Regulation and Release: Control of signaling enzyme localization and function by reversible S-acylation. J Biol Chem 2024:107696. [PMID: 39168183 DOI: 10.1016/j.jbc.2024.107696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 08/03/2024] [Accepted: 08/12/2024] [Indexed: 08/23/2024] Open
Abstract
An ever-growing number of studies highlight the importance of S-acylation, a reversible protein-lipid modification, for diverse aspects of intracellular signaling. In this review, we summarize the current understanding of how S-acylation regulates perhaps the best-known class of signaling enzymes, protein kinases. We describe how S-acylation acts as a membrane targeting signal that localizes certain kinases to specific membranes, and how such membrane localization in turn facilitates the assembly of signaling hubs consisting of an S-acylated kinase's upstream activators and/or downstream targets. We further discuss recent findings that S-acylation can control additional aspects of the function of certain kinases, including their interactions and, surprisingly, their activity, and how such regulation might be exploited for potential therapeutic gain. We go on to describe the roles and regulation of de-S-acylases and how extracellular signals drive dynamic (de)S-acylation of certain kinases. We discuss how S-acylation has the potential to lead to 'emergent properties' that alter the temporal profile and/or salience of intracellular signaling events. We close by giving examples of other S-acylation-dependent classes of signaling enzymes and by discussing how recent biological and technological advances should facilitate future studies into the functional roles of S-acylation-dependent signaling.
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Affiliation(s)
- Xiaotian Zhang
- Department of Neural Sciences and Shriners Hospitals Pediatric Research Center, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Gareth M Thomas
- Department of Neural Sciences and Shriners Hospitals Pediatric Research Center, 3500 N. Broad Street, Philadelphia, PA 19140, USA.
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3
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Gómez-Deza J, Nebiyou M, Alkaslasi MR, Nadal-Nicolás FM, Somasundaran P, Slavutsky AL, Ward ME, Li W, Watkins TA, Le Pichon CE. DLK-dependent axonal mitochondrial fission drives degeneration following axotomy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.01.30.526132. [PMID: 36778383 PMCID: PMC9915495 DOI: 10.1101/2023.01.30.526132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we developed a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma. We demonstrated that this apoptotic wave is locally initiated in the axon by dual leucine zipper kinase (DLK). We found that mitochondrial fission and resultant cell death are entirely dependent on phosphorylation of dynamin related protein 1 (DRP1) downstream of DLK, revealing a new mechanism by which DLK can drive apoptosis. Importantly, we show that CRISPR mediated Drp1 depletion protected mouse retinal ganglion neurons from degeneration after optic nerve crush. Our results provide a powerful platform for studying degeneration of human neurons, pinpoint key early events in damage related neural death and new focus for therapeutic intervention.
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Affiliation(s)
- Jorge Gómez-Deza
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Matthew Nebiyou
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Mor R Alkaslasi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | | | | | - Anastasia L Slavutsky
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Michael E Ward
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Wei Li
- National Eye Institute, National Institutes of Health, Bethesda, United States
| | - Trent A Watkins
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX
- Department of Neurology, University of California at San Francisco
| | - Claire E Le Pichon
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
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4
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Zhang X, Jeong H, Niu J, Holland SM, Rotanz BN, Gordon J, Einarson MB, Childers WE, Thomas GM. Novel inhibitors of acute, axonal DLK palmitoylation are neuroprotective and avoid the deleterious side effects of cell-wide DLK inhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.19.590310. [PMID: 38712276 PMCID: PMC11071345 DOI: 10.1101/2024.04.19.590310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Dual leucine-zipper kinase (DLK) drives acute and chronic forms of neurodegeneration, suggesting that inhibiting DLK signaling could ameliorate diverse neuropathological conditions. However, direct inhibition of DLK's kinase domain in human patients and conditional knockout of DLK in mice both cause unintended side effects, including elevated plasma neurofilament levels, indicative of neuronal cytoskeletal disruption. Indeed, we found that a DLK kinase domain inhibitor acutely disrupted the axonal cytoskeleton and caused vesicle aggregation in cultured dorsal root ganglion (DRG) neurons, further cautioning against this therapeutic strategy. In seeking a more precise intervention, we found that retrograde (axon-to-soma) pro-degenerative signaling requires acute, axonal palmitoylation of DLK and hypothesized that modulating this post-translational modification might be more specifically neuroprotective than cell-wide DLK inhibition. To address this possibility, we screened >28,000 compounds using a high-content imaging assay that quantitatively evaluates DLK's palmitoylation-dependent subcellular localization. Of the 33 hits that significantly altered DLK localization in non-neuronal cells, several reduced DLK retrograde signaling and protected cultured DRG neurons from DLK-dependent neurodegeneration. Mechanistically, the two most neuroprotective compounds selectively prevent stimulus-dependent palmitoylation of axonal pools of DLK, a process crucial for DLK's recruitment to axonal vesicles. In contrast, these compounds minimally impact DLK localization and signaling in healthy neurons and avoid the cytoskeletal disruption associated with direct DLK inhibition. Importantly, our hit compounds also reduce pro-degenerative retrograde signaling in vivo, suggesting that modulating DLK's palmitoylation-dependent localization could be a novel neuroprotective strategy.
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5
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Qian C, Xin Y, Qi C, Wang H, Dong BC, Zack DJ, Blackshaw S, Hattar S, Zhou FQ, Qian J. Intercellular communication atlas reveals Oprm1 as a neuroprotective factor for retinal ganglion cells. Nat Commun 2024; 15:2206. [PMID: 38467611 DOI: 10.1038/s41467-024-46428-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 02/26/2024] [Indexed: 03/13/2024] Open
Abstract
Previous studies of neuronal survival have primarily focused on identifying intrinsic mechanisms controlling the process. This study explored how intercellular communication contributes to retinal ganglion cell (RGC) survival following optic nerve crush based on single-cell RNA-seq analysis. We observed transcriptomic changes in retinal cells in response to the injury, with astrocytes and Müller glia having the most interactions with RGCs. By comparing RGC subclasses characterized by distinct resilience to cell death, we found that the high-survival RGCs tend to have more ligand-receptor interactions with neighboring cells. We identified 47 interactions stronger in high-survival RGCs, likely mediating neuroprotective effects. We validated one identified target, the μ-opioid receptor (Oprm1), to be neuroprotective in three retinal injury models. Although the endogenous Oprm1 is preferentially expressed in intrinsically photosensitive RGCs, its neuroprotective effect can be transferred to other subclasses by pan-RGC overexpression of Oprm1. Lastly, manipulating the Oprm1 activity improved visual functions in mice.
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Affiliation(s)
- Cheng Qian
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ying Xin
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Cheng Qi
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Hui Wang
- Section on Light and Circadian Rhythms, National Institute of Mental Health, Bethesda, MD, USA
| | - Bryan C Dong
- Neuroscience Study Program, Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Donald J Zack
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Seth Blackshaw
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Samer Hattar
- Section on Light and Circadian Rhythms, National Institute of Mental Health, Bethesda, MD, USA
| | - Feng-Quan Zhou
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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6
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Harris A, Verticchio Vercellin A, Weinreb RN, Khawaja A, MacGregor S, Pasquale LR. Lessons From The Glaucoma Foundation Think Tank 2023: A Patient-Centric Approach to Glaucoma. J Glaucoma 2024; 33:e1-e14. [PMID: 38129952 DOI: 10.1097/ijg.0000000000002353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
PRCIS The main takeaways also included that BIG DATA repositories and AI are important combinatory tools to foster novel strategies to prevent and stabilize glaucoma and, in the future, recover vision loss from the disease. PURPOSE To summarize the main topics discussed during the 28th Annual Glaucoma Foundation Think Tank Meeting "A Patient-Centric Approach to Glaucoma" held in New York on June 9 and 10, 2023. METHODS The highlights of the sessions on BIG DATA, genetics, modifiable lifestyle risk factors, female sex hormones, and neuroprotection in the field of primary open angle glaucoma (POAG) were summarized. RESULTS The researchers discussed the importance of BIG DATA repositories available at national and international levels for POAG research, including the United Kingdom Biobank. Combining genotyped large cohorts worldwide, facilitated by artificial intelligence (AI) and machine-learning approaches, led to the milestone discovery of 312 genome-wide significant disease loci for POAG. While these loci could be combined into a polygenic risk score with clinical utility, Think Tank meeting participants also provided analytical epidemiological evidence that behavioral risk factors modify POAG polygenetic risk, citing specific examples related to caffeine and alcohol use. The impact of female sex hormones on POAG pathophysiology was discussed, as was neuroprotection and the potential use of AI to help mitigate specific challenges faced in clinical trials and speed approval of neuroprotective agents. CONCLUSIONS The experts agreed on the importance of genetics in defining individual POAG risk and highlighted the additional crucial role of lifestyle, gender, blood pressure, and vascular risk factors. The main takeaways also included that BIG DATA repositories and AI are important combinatory tools to foster novel strategies to prevent and stabilize glaucoma and, in the future, recover vision loss from the disease.
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Affiliation(s)
- Alon Harris
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY
| | | | - Robert N Weinreb
- Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, UC San Diego, La Jolla, CA
| | - Anthony Khawaja
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Stuart MacGregor
- Statistical Genetics Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Louis R Pasquale
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY
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7
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Asghari Adib E, Shadrach JL, Reilly-Jankowiak L, Dwivedi MK, Rogers AE, Shahzad S, Passino R, Giger RJ, Pierchala BA, Collins CA. DLK signaling in axotomized neurons triggers complement activation and loss of upstream synapses. Cell Rep 2024; 43:113801. [PMID: 38363678 PMCID: PMC11088462 DOI: 10.1016/j.celrep.2024.113801] [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: 09/26/2022] [Revised: 12/27/2023] [Accepted: 01/31/2024] [Indexed: 02/18/2024] Open
Abstract
Axotomized spinal motoneurons (MNs) lose presynaptic inputs following peripheral nerve injury; however, the cellular mechanisms that lead to this form of synapse loss are currently unknown. Here, we delineate a critical role for neuronal kinase dual leucine zipper kinase (DLK)/MAP3K12, which becomes activated in axotomized neurons. Studies with conditional knockout mice indicate that DLK signaling activation in injured MNs triggers the induction of phagocytic microglia and synapse loss. Aspects of the DLK-regulated response include expression of C1q first from the axotomized MN and then later in surrounding microglia, which subsequently phagocytose presynaptic components of upstream synapses. Pharmacological ablation of microglia inhibits the loss of cholinergic C boutons from axotomized MNs. Together, the observations implicate a neuronal mechanism, governed by the DLK, in the induction of inflammation and the removal of synapses.
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Affiliation(s)
- Elham Asghari Adib
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Jennifer L Shadrach
- Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, MI, USA
| | | | - Manish K Dwivedi
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Abigail E Rogers
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Shameena Shahzad
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Ryan Passino
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Roman J Giger
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Brian A Pierchala
- Department of Biologic and Materials Sciences, University of Michigan, Ann Arbor, MI, USA; Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Catherine A Collins
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA; Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA.
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8
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Köster KA, Dethlefs M, Duque Escobar J, Oetjen E. Regulation of the Activity of the Dual Leucine Zipper Kinase by Distinct Mechanisms. Cells 2024; 13:333. [PMID: 38391946 PMCID: PMC10886912 DOI: 10.3390/cells13040333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/24/2024] Open
Abstract
The dual leucine zipper kinase (DLK) alias mitogen-activated protein 3 kinase 12 (MAP3K12) has gained much attention in recent years. DLK belongs to the mixed lineage kinases, characterized by homology to serine/threonine and tyrosine kinase, but exerts serine/threonine kinase activity. DLK has been implicated in many diseases, including several neurodegenerative diseases, glaucoma, and diabetes mellitus. As a MAP3K, it is generally assumed that DLK becomes phosphorylated and activated by upstream signals and phosphorylates and activates itself, the downstream serine/threonine MAP2K, and, ultimately, MAPK. In addition, other mechanisms such as protein-protein interactions, proteasomal degradation, dephosphorylation by various phosphatases, palmitoylation, and subcellular localization have been shown to be involved in the regulation of DLK activity or its fine-tuning. In the present review, the diverse mechanisms regulating DLK activity will be summarized to provide better insights into DLK action and, possibly, new targets to modulate DLK function.
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Affiliation(s)
- Kyra-Alexandra Köster
- Department of Clinical Pharmacology and Toxicology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (K.-A.K.); (M.D.)
- DZHK Standort Hamburg, Kiel, Lübeck, Germany;
| | - Marten Dethlefs
- Department of Clinical Pharmacology and Toxicology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (K.-A.K.); (M.D.)
- DZHK Standort Hamburg, Kiel, Lübeck, Germany;
| | - Jorge Duque Escobar
- DZHK Standort Hamburg, Kiel, Lübeck, Germany;
- University Center of Cardiovascular Science, Department of Cardiology, University Heart & Vascular Center Hamburg, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - Elke Oetjen
- Department of Clinical Pharmacology and Toxicology, University Medical Centre Hamburg-Eppendorf, 20246 Hamburg, Germany; (K.-A.K.); (M.D.)
- DZHK Standort Hamburg, Kiel, Lübeck, Germany;
- Institute of Pharmacy, University of Hamburg, 20146 Hamburg, Germany
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9
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Kim S, Quagraine Y, Singh M, Kim JH. Rab11 suppresses neuronal stress signaling by localizing Dual leucine zipper kinase to axon terminals for protein turnover. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.18.537392. [PMID: 37131782 PMCID: PMC10153120 DOI: 10.1101/2023.04.18.537392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Dual Leucine Zipper Kinase (DLK) mediates multiple neuronal stress responses, and its expression levels are constantly suppressed to prevent excessive stress signaling. We found that Wallenda (Wnd), the Drosophila ortholog of DLK, is highly enriched in the axon terminals of Drosophila sensory neurons in vivo and that this subcellular localization is necessary for Highwire-mediated Wnd protein turnover under normal conditions. Our structure-function analysis found that Wnd palmitoylation is essential for its axon terminal localization. Palmitoylation-defective Wnd accumulated in neuronal cell bodies, exhibited dramatically increased protein expression levels, and triggered excessive neuronal stress responses. Defective intracellular transport is implicated in neurodegenerative conditions. Comprehensive dominant-negative Rab protein screening identified Rab11 as an essential factor for Wnd localization in axon terminals. Consequently, Rab11 loss-of-function increased the protein levels of Wnd and induced neuronal stress responses. Inhibiting Wnd activity significantly ameliorated neuronal loss and c-Jun N-terminal kinase signaling triggered by Rab11 loss-of-function. Taken together, these suggest that DLK proteins are constantly transported to axon terminals by Rab11 for protein turnover. Our study demonstrates how subcellular protein localization is coupled to protein turnover for neuronal stress signaling. Highlights Wnd is highly enriched in axon terminals.Wnd protein turnover by Hiw is restricted in the axon terminals.Protein palmitoylation of Wnd and Rab11 activity is essential for Wnd axonal localization. Rab11 mutations and defective Wnd palmitoylation impair Wnd protein turnover leading to increased Wnd protein levels and neuronal loss. Inhibiting Wnd activity mitigates neuronal stress response caused by Rab11 loss-of-function.
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10
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Estera LA, Walsh SP, Headen JA, Williamson RE, Kalinski AL. Neuroinflammation: Breaking barriers and bridging gaps. Neurosci Res 2023; 197:9-17. [PMID: 34748905 DOI: 10.1016/j.neures.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 11/01/2021] [Indexed: 01/04/2023]
Abstract
Neurons are the cells of the nervous system and are responsible for every thought, movement and perception. Immune cells are the cells of the immune system, constantly protecting from foreign pathogens. Understanding the interaction between the two systems is especially important in disease states such as autoimmune or neurodegenerative disease. Unfortunately, this interaction is typically detrimental to the host. However, recent efforts have focused on how neurons and immune cells interact, either directly or indirectly, following traumatic injury to the nervous system. The outcome of this interaction can be beneficial - leading to successful neural repair, or detrimental - leading to functional deficits, depending on where the injury occurs. This review will discuss our understanding of neuron-immune cell interactions after traumatic injury to both the peripheral and central nervous system.
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Affiliation(s)
- Lora A Estera
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Sam P Walsh
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Jordan A Headen
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | | | - Ashley L Kalinski
- Department of Biology, Ball State University, Muncie, IN 47306, USA.
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Zuo Z, Zhang Z, Zhang S, Fan B, Li G. The Molecular Mechanisms Involved in Axonal Degeneration and Retrograde Retinal Ganglion Cell Death. DNA Cell Biol 2023; 42:653-667. [PMID: 37819746 DOI: 10.1089/dna.2023.0180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023] Open
Abstract
Axonal degeneration is a pathologic change common to multiple retinopathies and optic neuropathies. Various pathologic factors, such as mechanical injury, inflammation, and ischemia, can damage retinal ganglion cell (RGC) somas and axons, eventually triggering axonal degeneration and RGC death. The molecular mechanisms of somal and axonal degeneration are distinct but also overlap, and axonal degeneration can result in retrograde somal degeneration. While the mitogen-activated protein kinase pathway acts as a central node in RGC axon degeneration, several newly discovered molecules, such as sterile alpha and Toll/interleukin-1 receptor motif-containing protein 1 and nicotinamide mononucleotide adenylyltransferase 2, also play a critical role in this pathological process following different types of injury. Therefore, we summarize the types of injury that cause RGC axon degeneration and retrograde RGC death and important underlying molecular mechanisms, providing a reference for the identification of targets for protecting axons and RGCs.
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Affiliation(s)
- Zhaoyang Zuo
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
| | - Ziyuan Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
| | - Siming Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
| | - Bin Fan
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
| | - Guangyu Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
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12
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Benowitz LI, Xie L, Yin Y. Inflammatory Mediators of Axon Regeneration in the Central and Peripheral Nervous Systems. Int J Mol Sci 2023; 24:15359. [PMID: 37895039 PMCID: PMC10607492 DOI: 10.3390/ijms242015359] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Although most pathways in the mature central nervous system cannot regenerate when injured, research beginning in the late 20th century has led to discoveries that may help reverse this situation. Here, we highlight research in recent years from our laboratory identifying oncomodulin (Ocm), stromal cell-derived factor (SDF)-1, and chemokine CCL5 as growth factors expressed by cells of the innate immune system that promote axon regeneration in the injured optic nerve and elsewhere in the central and peripheral nervous systems. We also review the role of ArmC10, a newly discovered Ocm receptor, in mediating many of these effects, and the synergy between inflammation-derived growth factors and complementary strategies to promote regeneration, including deleting genes encoding cell-intrinsic suppressors of axon growth, manipulating transcription factors that suppress or promote the expression of growth-related genes, and manipulating cell-extrinsic suppressors of axon growth. In some cases, combinatorial strategies have led to unprecedented levels of nerve regeneration. The identification of some similar mechanisms in human neurons offers hope that key discoveries made in animal models may eventually lead to treatments to improve outcomes after neurological damage in patients.
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Affiliation(s)
- Larry I. Benowitz
- Department of Neurosurgery, Boston Children’s Hospital, Boston, MA 02115, USA; (L.X.); (Y.Y.)
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurosurgery, Harvard Medical School, Boston, MA 02115, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA
| | - Lili Xie
- Department of Neurosurgery, Boston Children’s Hospital, Boston, MA 02115, USA; (L.X.); (Y.Y.)
- Department of Neurosurgery, Harvard Medical School, Boston, MA 02115, USA
- Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yuqin Yin
- Department of Neurosurgery, Boston Children’s Hospital, Boston, MA 02115, USA; (L.X.); (Y.Y.)
- Department of Neurosurgery, Harvard Medical School, Boston, MA 02115, USA
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13
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Hsueh HT, Chou RT, Rai U, Kolodziejski P, Liyanage W, Pejavar J, Mozzer A, Davison C, Appell MB, Kim YC, Leo KT, Kwon H, Sista M, Anders NM, Hemingway A, Rompicharla SVK, Pitha I, Zack DJ, Hanes J, Cummings MP, Ensign LM. Engineered peptide-drug conjugate provides sustained protection of retinal ganglion cells with topical administration in rats. J Control Release 2023; 362:371-380. [PMID: 37657693 PMCID: PMC10591956 DOI: 10.1016/j.jconrel.2023.08.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 05/03/2023] [Accepted: 08/29/2023] [Indexed: 09/03/2023]
Abstract
Effective eye drop delivery systems for treating diseases of the posterior segment have yet to be clinically validated. Further, adherence to eye drop regimens is often problematic due to the difficulty and inconvenience of repetitive dosing. Here, we describe a strategy for topically dosing a peptide-drug conjugate to achieve effective and sustained therapeutic sunitinib concentrations to protect retinal ganglion cells (RGCs) in a rat model of optic nerve injury. We combined two promising delivery technologies, namely, a hypotonic gel-forming eye drop delivery system, and an engineered melanin binding and cell-penetrating peptide that sustains intraocular drug residence time. We found that once daily topical dosing of HR97-SunitiGel provided up to 2 weeks of neuroprotection after the last dose, effectively doubling the therapeutic window observed with SunitiGel. For chronic ocular diseases affecting the posterior segment, the convenience of an eye drop combined with intermittent dosing frequency could result in greater patient adherence, and thus, improved disease management.
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Affiliation(s)
- Henry T Hsueh
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Renee Ti Chou
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, USA
| | - Usha Rai
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Patricia Kolodziejski
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Wathsala Liyanage
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jahnavi Pejavar
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Ann Mozzer
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Charlotte Davison
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Matthew B Appell
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Yoo Chun Kim
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kirby T Leo
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - HyeYoung Kwon
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Maanasa Sista
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Nicole M Anders
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD, USA
| | - Avelina Hemingway
- The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD, USA
| | - Sri Vishnu Kiran Rompicharla
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ian Pitha
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Donald J Zack
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Departments of Neuroscience, Molecular Biology and Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Justin Hanes
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD, USA
| | - Michael P Cummings
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, USA
| | - Laura M Ensign
- Center for Nanomedicine at the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Chemical & Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins University, Baltimore, MD, USA.
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14
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Agarwal D, Dash N, Mazo KW, Chopra M, Avila MP, Patel A, Wong RM, Jia C, Do H, Cheng J, Chiang C, Jurlina SL, Roshan M, Perry MW, Rho JM, Broyer R, Lee CD, Weinreb RN, Gavrilovici C, Oesch NW, Welsbie DS, Wahlin KJ. Human retinal ganglion cell neurons generated by synchronous BMP inhibition and transcription factor mediated reprogramming. NPJ Regen Med 2023; 8:55. [PMID: 37773257 PMCID: PMC10541876 DOI: 10.1038/s41536-023-00327-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 08/31/2023] [Indexed: 10/01/2023] Open
Abstract
In optic neuropathies, including glaucoma, retinal ganglion cells (RGCs) die. Cell transplantation and endogenous regeneration offer strategies for retinal repair, however, developmental programs required for this to succeed are incompletely understood. To address this, we explored cellular reprogramming with transcription factor (TF) regulators of RGC development which were integrated into human pluripotent stem cells (PSCs) as inducible gene cassettes. When the pioneer factor NEUROG2 was combined with RGC-expressed TFs (ATOH7, ISL1, and POU4F2) some conversion was observed and when pre-patterned by BMP inhibition, RGC-like induced neurons (RGC-iNs) were generated with high efficiency in just under a week. These exhibited transcriptional profiles that were reminiscent of RGCs and exhibited electrophysiological properties, including AMPA-mediated synaptic transmission. Additionally, we demonstrated that small molecule inhibitors of DLK/LZK and GCK-IV can block neuronal death in two pharmacological axon injury models. Combining developmental patterning with RGC-specific TFs thus provided valuable insight into strategies for cell replacement and neuroprotection.
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Affiliation(s)
- Devansh Agarwal
- Shu Chien-Gene Lay Department of Bioengineering, UC San Diego, La Jolla, CA, USA
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Nicholas Dash
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Kevin W Mazo
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Manan Chopra
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Maria P Avila
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Amit Patel
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Ryan M Wong
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Cairang Jia
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Hope Do
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Jie Cheng
- Department of Ophthalmology, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Colette Chiang
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Shawna L Jurlina
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Mona Roshan
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Michael W Perry
- Department of Biological Sciences, UC San Diego, La Jolla, CA, USA
| | - Jong M Rho
- Department of Neurosciences, UC San Diego, La Jolla, CA, USA
| | - Risa Broyer
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Cassidy D Lee
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Robert N Weinreb
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | | | - Nicholas W Oesch
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
- Department of Psychology, UC San Diego, La Jolla, CA, USA
| | - Derek S Welsbie
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA
| | - Karl J Wahlin
- Viterbi Family Department of Ophthalmology & the Shiley Eye Institute, UC San Diego, La Jolla, CA, USA.
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15
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Maes ME, Donahue RJ, Schlamp CL, Marola OJ, Libby RT, Nickells RW. BAX activation in mouse retinal ganglion cells occurs in two temporally and mechanistically distinct steps. Mol Neurodegener 2023; 18:67. [PMID: 37752598 PMCID: PMC10521527 DOI: 10.1186/s13024-023-00659-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
BACKGROUND Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then permeabilization of the MOM to facilitate the release of apoptotic signaling molecules. As a critical component of RGC death, BAX is an attractive target for neuroprotective therapies and an understanding of the kinetics of BAX activation and the mechanisms controlling the two stages of this process in RGCs is potentially valuable in informing the development of a neuroprotective strategy. METHODS The kinetics of BAX translocation were assessed by both static and live-cell imaging of a GFP-BAX fusion protein introduced into RGCs using AAV2-mediated gene transfer in mice. Activation of BAX was achieved using an acute optic nerve crush (ONC) protocol. Live-cell imaging of GFP-BAX was achieved using explants of mouse retina harvested 7 days after ONC. Kinetics of translocation in RGCs were compared to GFP-BAX translocation in 661W tissue culture cells. Permeabilization of GFP-BAX was assessed by staining with the 6A7 monoclonal antibody, which recognizes a conformational change in this protein after MOM insertion. Assessment of individual kinases associated with both stages of activation was made using small molecule inhibitors injected into the vitreous either independently or in concert with ONC surgery. The contribution of the Dual Leucine Zipper-JUN-N-Terminal Kinase cascade was evaluated using mice with a double conditional knock-out of both Mkk4 and Mkk7. RESULTS ONC induces the translocation of GFP-BAX in RGCs at a slower rate and with less intracellular synchronicity than 661W cells, but exhibits less variability among mitochondrial foci within a single cell. GFP-BAX was also found to translocate in all compartments of an RGC including the dendritic arbor and axon. Approximately 6% of translocating RGCs exhibited retrotranslocation of BAX immediately following translocation. Unlike tissue culture cells, which exhibit simultaneous translocation and permeabilization, RGCs exhibited a significant delay between these two stages, similar to detached cells undergoing anoikis. Translocation, with minimal permeabilization could be induced in a subset of RGCs using an inhibitor of Focal Adhesion Kinase (PF573228). Permeabilization after ONC, in a majority of RGCs, could be inhibited with a broad spectrum kinase inhibitor (sunitinib) or a selective inhibitor for p38/MAPK14 (SB203580). Intervention of DLK-JNK axis signaling abrogated GFP-BAX translocation after ONC. CONCLUSIONS A comparison between BAX activation kinetics in tissue culture cells and in cells of a complex tissue environment shows distinct differences indicating that caution should be used when translating findings from one condition to the other. RGCs exhibit both a delay between translocation and permeabilization and the ability for translocated BAX to be retrotranslocated, suggesting several stages at which intervention of the activation process could be exploited in the design of a therapeutic strategy.
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Affiliation(s)
- Margaret E Maes
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria
| | - Ryan J Donahue
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA
| | - Olivia J Marola
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA
| | - Richard T Libby
- Department of Ophthalmology, University of Rochester Medical Center, Rochester, NY, USA
| | - Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, 1300 University Avenue, Madison, WI, 53706, USA.
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA.
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16
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Qian C, Xin Y, Cheng Q, Wang H, Zack D, Blackshaw S, Hattar S, Feng-Quan Z, Qian J. Intercellular communication atlas reveals Oprm1 as a neuroprotective factor for retinal ganglion cells. RESEARCH SQUARE 2023:rs.3.rs-3193738. [PMID: 37645816 PMCID: PMC10462234 DOI: 10.21203/rs.3.rs-3193738/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The progressive death of mature neurons often results in neurodegenerative diseases. While the previous studies have mostly focused on identifying intrinsic mechanisms controlling neuronal survival, the extracellular environment also plays a critical role in regulating cell viability. Here we explore how intercellular communication contributes to the survival of retinal ganglion cells (RGCs) following the optic nerve crush (ONC). Although the direct effect of the ONC is restricted to the RGCs, we observed transcriptomic responses in other retinal cells to the injury based on the single-cell RNA-seq, with astrocytes and Müller glia having the most interactions with RGCs. By comparing the RGC subclasses showing distinct resilience to ONC-induced cell death, we found that the high-survival RGCs tend to have more ligand-receptor interactions with other retinal cells, suggesting that these RGCs are intrinsically programmed to foster more communication with their surroundings. Furthermore, we identified top 47 interactions that are stronger in the high-survival RGCs, likely representing neuroprotective interactions. We performed functional assays on one of the receptors, μ opioid receptor (Oprm1), a receptor known to play roles in regulating pain, reward, and addictive behavior. Although Oprm1 is preferentially expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs), its neuroprotective effect could be transferred to multiple RGC subclasses by specific overexpressing Oprm1 in pan-RGCs in ONC, excitotoxicity, and glaucoma models. Lastly, manipulating Oprm1 activity improved visual functions and altered pupillary light response in mice. Our study provides an atlas of cell-cell interactions in both intact and post-ONC retina and an effective strategy to predict molecular mechanisms in neuroprotection, underlying the principal role played by extracellular environment in supporting neuron survival.
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Affiliation(s)
- Cheng Qian
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Ying Xin
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Qi Cheng
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hui Wang
- Section on Light and Circadian Rhythms, National Institute of Mental Health, Bethesda, Maryland, United States
| | - Donald Zack
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Samer Hattar
- Section on Light and Circadian Rhythms, National Institute of Mental Health, Bethesda, Maryland, United States
| | - Zhou Feng-Quan
- Department of Orthopaedic Surgery, Johns Hopkins University School of Medicine, Baltimore, United States
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, United States
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, United States
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17
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Alexandris AS, Lee Y, Lehar M, Alam Z, McKenney J, Perdomo D, Ryu J, Welsbie D, Zack DJ, Koliatsos VE. Traumatic Axonal Injury in the Optic Nerve: The Selective Role of SARM1 in the Evolution of Distal Axonopathy. J Neurotrauma 2023; 40:1743-1761. [PMID: 36680758 PMCID: PMC10460965 DOI: 10.1089/neu.2022.0416] [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] [Indexed: 01/22/2023] Open
Abstract
Traumatic axonal injury (TAI), thought to be caused by rotational acceleration of the head, is a prevalent neuropathology in traumatic brain injury (TBI). TAI in the optic nerve is a common finding in multiple blunt-force TBI models and hence a great model to study mechanisms and treatments for TAI, especially in view of the compartmentalized anatomy of the visual system. We have previously shown that the somata and the proximal, but not distal, axons of retinal ganglion cells (RGC) respond to DLK/LZK blockade after impact acceleration of the head (IA-TBI). Here, we explored the role of the sterile alpha and TIR-motif containing 1 (SARM1), the key driver of Wallerian degeneration (WD), in the progressive breakdown of distal and proximal segments of the optic nerve following IA-TBI with high-resolution morphological and classical neuropathological approaches. Wild type and Sarm1 knockout (KO) mice received IA-TBI or sham injury and were allowed to survive for 3, 7, 14, and 21 days. Ultrastructural and microscopic analyses revealed that TAI in the optic nerve is characterized by variable involvement of individual axons, ranging from apparent early disconnection of a subpopulation of axons to a range of ongoing axonal and myelin perturbations. Traumatic axonal injury resulted in the degeneration of a population of axons distal and proximal to the injury, along with retrograde death of a subpopulation of RGCs. Quantitative analyses on proximal and distal axons and RGC somata revealed that different neuronal domains exhibit differential vulnerability, with distal axon segments showing more severe degeneration compared with proximal segments and RGC somata. Importantly, we found that Sarm1 KO had a profound effect in the distal optic nerve by suppressing axonal degeneration by up to 50% in the first 2 weeks after IA-TBI, with a continued but lower effect at 3 weeks, while also suppressing microglial activation. Sarm1 KO had no evident effect on the initial traumatic disconnection and did not ameliorate the proximal optic axonopathy or the subsequent attrition of RGCs, indicating that the fate of different axonal segments in the course of TAI may depend on distinct molecular programs within axons.
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Affiliation(s)
| | - Youngrim Lee
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mohamed Lehar
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zahra Alam
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - James McKenney
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Dianela Perdomo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiwon Ryu
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Derek Welsbie
- Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, California, USA
| | - Donald J. Zack
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neuroscience Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Vassilis E. Koliatsos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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18
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Qian C, Xin Y, Qi C, Wang H, Dong BC, Zack D, Blackshaw S, Hattar S, Zhou FQ, Qian J. Intercellular communication atlas reveals Oprm1 as a neuroprotective factor for retinal ganglion cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.14.549118. [PMID: 37502873 PMCID: PMC10370148 DOI: 10.1101/2023.07.14.549118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The progressive death of mature neurons often results in neurodegenerative diseases. While the previous studies have mostly focused on identifying intrinsic mechanisms controlling neuronal survival, the extracellular environment also plays a critical role in regulating cell viability. Here we explore how intercellular communication contributes to the survival of retinal ganglion cells (RGCs) following the optic nerve crush (ONC). Although the direct effect of the ONC is restricted to the RGCs, we observed transcriptomic responses in other retinal cells to the injury based on the single-cell RNA-seq, with astrocytes and Müller glia having the most interactions with RGCs. By comparing the RGC subclasses with distinct resilience to ONC-induced cell death, we found that the high-survival RGCs tend to have more ligand-receptor interactions with other retinal cells, suggesting that these RGCs are intrinsically programmed to foster more communication with their surroundings. Furthermore, we identified the top 47 interactions that are stronger in the high-survival RGCs, likely representing neuroprotective interactions. We performed functional assays on one of the receptors, μ-opioid receptor (Oprm1), a receptor known to play roles in regulating pain, reward, and addictive behavior. Although Oprm1 is preferentially expressed in intrinsically photosensitive retinal ganglion cells (ipRGC), its neuroprotective effect could be transferred to multiple RGC subclasses by selectively overexpressing Oprm1 in pan-RGCs in ONC, excitotoxicity, and glaucoma models. Lastly, manipulating Oprm1 activity improved visual functions or altered pupillary light response in mice. Our study provides an atlas of cell-cell interactions in intact and post-ONC retina, and a strategy to predict molecular mechanisms controlling neuroprotection, underlying the principal role played by extracellular environment in supporting neuron survival.
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19
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Maes ME, Donahue RJ, Schlamp CL, Marola OJ, Libby RT, Nickells R. BAX activation in mouse retinal ganglion cells occurs in two temporally and mechanistically distinct steps. RESEARCH SQUARE 2023:rs.3.rs-2846437. [PMID: 37292963 PMCID: PMC10246290 DOI: 10.21203/rs.3.rs-2846437/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Background Pro-apoptotic BAX is a central mediator of retinal ganglion cell (RGC) death after optic nerve damage. BAX activation occurs in two stages including translocation of latent BAX to the mitochondrial outer membrane (MOM) and then permeabilization of the MOM to facilitate the release of apoptotic signaling molecules. As a critical component of RGC death, BAX is an attractive target for neuroprotective therapies and an understanding of the kinetics of BAX activation and the mechanisms controlling the two stages of this process in RGCs is potentially valuable in informing the development of a neuroprotective strategy. Methods The kinetics of BAX translocation were assessed by both static and live-cell imaging of a GFP-BAX fusion protein introduced into RGCs using AAV2-mediated gene transfer in mice. Activation of BAX was achieved using an acute optic nerve crush (ONC) protocol. Live-cell imaging of GFP-BAX was achieved using explants of mouse retina harvested 7 days after ONC. Kinetics of translocation in RGCs were compared to GFP-BAX translocation in 661W tissue culture cells. Permeabilization of GFP-BAX was assessed by staining with the 6A7 monoclonal antibody, which recognizes a conformational change in this protein after MOM insertion. Assessment of individual kinases associated with both stages of activation was made using small molecule inhibitors injected into the vitreous either independently or in concert with ONC surgery. The contribution of the Dual Leucine Zipper-JUN-N-Terminal Kinase cascade was evaluated using mice with a double conditional knock-out of both Mkk4 and Mkk7 . Results ONC induces the translocation of GFP-BAX in RGCs at a slower rate and with less intracellular synchronicity than 661W cells, but exhibits less variability among mitochondrial foci within a single cell. GFP-BAX was also found to translocate in all compartments of an RGC including the dendritic arbor and axon. Approximately 6% of translocating RGCs exhibited retrotranslocation of BAX immediately following translocation. Unlike tissue culture cells, which exhibit simultaneous translocation and permeabilization, RGCs exhibited a significant delay between these two stages, similar to detached cells undergoing anoikis. Translocation, with minimal permeabilization could be induced in a subset of RGCs using an inhibitor of Focal Adhesion Kinase (PF573228). Permeabilization after ONC, in a majority of RGCs, could be inhibited with a broad spectrum kinase inhibitor (sunitinib) or a selective inhibitor for p38/MAPK14 (SB203580). Intervention of DLK-JNK axis signaling abrogated GFP-BAX translocation after ONC. Conclusions A comparison between BAX activation kinetics in tissue culture cells and in cells of a complex tissue environment shows distinct differences indicating that caution should be used when translating findings from one condition to the other. RGCs exhibit both a delay between translocation and permeabilization and the ability for translocated BAX to be retrotranslocated, suggesting several stages at which intervention of the activation process could be exploited in the design of a therapeutic strategy.
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20
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Fague L, Marsh-Armstrong N. Dual leucine zipper kinase is necessary for retinal ganglion cell axonal regeneration in Xenopus laevis. PNAS NEXUS 2023; 2:pgad109. [PMID: 37152673 PMCID: PMC10162689 DOI: 10.1093/pnasnexus/pgad109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/08/2023] [Indexed: 05/09/2023]
Abstract
Retinal ganglion cell (RGC) axons of the African clawed frog, Xenopus laevis, unlike those of mammals, are capable of regeneration and functional reinnervation of central brain targets following injury. Here, we describe a tadpole optic nerve crush (ONC) procedure and assessments of brain reinnervation based on live imaging of RGC-specific transgenes which, when paired with CRISPR/Cas9 injections at the one-cell stage, can be used to assess the function of regeneration-associated genes in vivo in F0 animals. Using this assay, we find that map3k12, also known as dual leucine zipper kinase (Dlk), is necessary for RGC axonal regeneration and acts in a dose-dependent manner. Loss of Dlk does not affect RGC innervation of the brain during development or visually driven behavior but does block both axonal regeneration and functional vision restoration after ONC. Dlk loss does not alter the acute changes in mitochondrial movement that occur within RGC axons hours after ONC but does completely block the phosphorylation and nuclear translocation of the transcription factor Jun within RGCs days after ONC; yet, Jun is dispensable for reinnervation. These results demonstrate that in a species fully capable of regenerating its RGC axons, Dlk is essential for the axonal injury signal to reach the nucleus but may affect regeneration through a different pathway than by which it signals in mammalian RGCs.
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Affiliation(s)
- Lindsay Fague
- Department of Ophthalmology and Vision Science, UC Davis Eye Center, University of California, Davis, 1275 Med Science Drive Rm. 3451, Davis, CA 95616, USA
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21
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Bu H, Li Z, Lu Y, Zhuang Z, Zhen Y, Zhang L. Deciphering the multifunctional role of dual leucine zipper kinase (DLK) and its therapeutic potential in disease. Eur J Med Chem 2023; 255:115404. [PMID: 37098296 DOI: 10.1016/j.ejmech.2023.115404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/19/2023] [Accepted: 04/19/2023] [Indexed: 04/27/2023]
Abstract
Dual leucine zipper kinase (DLK, MAP3K12), a serine/threonine protein kinase, plays a key role in neuronal development, as it regulates axon regeneration and degeneration through its downstream kinase. Importantly, DLK is closely related to the pathogenesis of numerous neurodegenerative diseases and the induction of β-cell apoptosis that leads to diabetes. In this review, we summarize the current understanding of DLK function, and then discuss the role of DLK signaling in human diseases. Furthermore, various types of small molecule inhibitors of DLK that have been published so far are described in detail in this paper, providing some strategies for the design of DLK small molecule inhibitors in the future.
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Affiliation(s)
- Haiqing Bu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Zhijia Li
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Yingying Lu
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Zhiyao Zhuang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China
| | - Yongqi Zhen
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Lan Zhang
- Sichuan Engineering Research Center for Biomimetic Synthesis of Natural Drugs, School of Life Science and Engineering, Southwest Jiaotong University, Chengdu, 610031, China.
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Boal AM, McGrady NR, Chamling X, Kagitapalli BS, Zack DJ, Calkins DJ, Risner ML. Microfluidic Platforms Promote Polarization of Human-Derived Retinal Ganglion Cells That Model Axonopathy. Transl Vis Sci Technol 2023; 12:1. [PMID: 37010860 PMCID: PMC10080917 DOI: 10.1167/tvst.12.4.1] [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: 12/06/2022] [Accepted: 03/09/2023] [Indexed: 04/04/2023] Open
Abstract
Purpose Axons depend on long-range transport of proteins and organelles which increases susceptibility to metabolic stress in disease. The axon initial segment (AIS) is particularly vulnerable due to the high bioenergetic demand of action potential generation. Here, we prepared retinal ganglion cells derived from human embryonic stem cells (hRGCs) to probe how axonal stress alters AIS morphology. Methods hRGCs were cultured on coverslips or microfluidic platforms. We assayed AIS specification and morphology by immunolabeling against ankyrin G (ankG), an axon-specific protein, and postsynaptic density 95 (PSD-95), a dendrite-specific protein. Using microfluidic platforms that enable fluidic isolation, we added colchicine to the axon compartment to lesion axons. We verified axonopathy by measuring the anterograde axon transport of cholera toxin subunit B and immunolabeling against cleaved caspase 3 (CC3) and phosphorylated neurofilament H (SMI-34). We determined the influence of axon injury on AIS morphology by immunolabeling samples against ankG and measuring AIS distance from soma and length. Results Based on measurements of ankG and PSD-95 immunolabeling, microfluidic platforms promote the formation and separation of distinct somatic-dendritic versus axonal compartments in hRGCs compared to coverslip cultures. Chemical lesioning of axons by colchicine reduced hRGC anterograde axon transport, increased varicosity density, and enhanced expression of CC3 and SMI-34. Interestingly, we found that colchicine selectively affected hRGCs with axon-carrying dendrites by reducing AIS distance from somas and increasing length, thus suggesting reduced capacity to maintain excitability. Conclusions Thus, microfluidic platforms promote polarized hRGCs that enable modeling of axonopathy. Translational Relevance Microfluidic platforms may be used to assay compartmentalized degeneration that occurs during glaucoma.
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Affiliation(s)
- Andrew M. Boal
- Vanderbilt Eye Institute, Department of Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nolan R. McGrady
- Vanderbilt Eye Institute, Department of Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Xitiz Chamling
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bhanu S. Kagitapalli
- Vanderbilt Eye Institute, Department of Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Donald J. Zack
- Wilmer Eye Institute, Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David J. Calkins
- Vanderbilt Eye Institute, Department of Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael L. Risner
- Vanderbilt Eye Institute, Department of Ophthalmology & Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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Somasundaram P, Farley MM, Rudy MA, Stefanoff DG, Shah M, Goli P, Heo J, Wang S, Tran NM, Watkins TA. Coordinated stimulation of axon regenerative and neurodegenerative transcriptional programs by Atf4 following optic nerve injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534798. [PMID: 37034690 PMCID: PMC10081193 DOI: 10.1101/2023.03.29.534798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Previously we showed that neurodegeneration initiated by axonal insults depends in part on the stress-responsive kinase Perk (Larhammar et al., 2017). Here we show that Perk acts primarily through Activating Transcription Factor-4 (Atf4) to stimulate not only pro-apoptotic but also pro-regenerative responses following optic nerve injury. Using conditional knockout mice, we find an extensive Perk/Atf4-dependent transcriptional response that includes canonical Atf4 target genes and modest contributions by C/ebp homologous protein (Chop). Overlap with c-Jun-dependent transcription suggests interplay with a parallel stress pathway that couples regenerative and apoptotic responses. Accordingly, neuronal knockout of Atf4 recapitulates the neuroprotection afforded by Perk deficiency, and Perk or Atf4 knockout impairs optic axon regeneration enabled by disrupting the tumor suppressor Pten. These findings contrast with the transcriptional and functional consequences reported for CRISPR targeting of Atf4 or Chop and reveal an integral role for Perk/Atf4 in coordinating neurodegenerative and regenerative responses to CNS axon injury.
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24
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Christopher M, Hoseini P, Walker E, Proudfoot JA, Bowd C, Fazio MA, Girkin CA, De Moraes CG, Liebmann JM, Weinreb RN, Schwartzman A, Zangwill LM, Welsbie DS. A Deep Learning Approach to Improve Retinal Structural Predictions and Aid Glaucoma Neuroprotective Clinical Trial Design. Ophthalmol Glaucoma 2023; 6:147-159. [PMID: 36038107 DOI: 10.1016/j.ogla.2022.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 08/02/2022] [Accepted: 08/19/2022] [Indexed: 10/15/2022]
Abstract
PURPOSE To investigate the efficacy of a deep learning regression method to predict macula ganglion cell-inner plexiform layer (GCIPL) and optic nerve head (ONH) retinal nerve fiber layer (RNFL) thickness for use in glaucoma neuroprotection clinical trials. DESIGN Cross-sectional study. PARTICIPANTS Glaucoma patients with good quality macula and ONH scans enrolled in 2 longitudinal studies, the African Descent and Glaucoma Evaluation Study and the Diagnostic Innovations in Glaucoma Study. METHODS Spectralis macula posterior pole scans and ONH circle scans on 3327 pairs of GCIPL/RNFL scans from 1096 eyes (550 patients) were included. Participants were randomly distributed into a training and validation dataset (90%) and a test dataset (10%) by participant. Networks had access to GCIPL and RNFL data from one hemiretina of the probe eye and all data of the fellow eye. The models were then trained to predict the GCIPL or RNFL thickness of the remaining probe eye hemiretina. MAIN OUTCOME MEASURES Mean absolute error (MAE) and squared Pearson correlation coefficient (r2) were used to evaluate model performance. RESULTS The deep learning model was able to predict superior and inferior GCIPL thicknesses with a global r2 value of 0.90 and 0.86, r2 of mean of 0.90 and 0.86, and mean MAE of 3.72 μm and 4.2 μm, respectively. For superior and inferior RNFL thickness predictions, model performance was slightly lower, with a global r2 of 0.75 and 0.84, r2 of mean of 0.81 and 0.82, and MAE of 9.31 μm and 8.57 μm, respectively. There was only a modest decrease in model performance when predicting GCIPL and RNFL in more severe disease. Using individualized hemiretinal predictions to account for variability across patients, we estimate that a clinical trial can detect a difference equivalent to a 25% treatment effect over 24 months with an 11-fold reduction in the number of patients compared to a conventional trial. CONCLUSIONS Our deep learning models were able to accurately estimate both macula GCIPL and ONH RNFL hemiretinal thickness. Using an internal control based on these model predictions may help reduce clinical trial sample size requirements and facilitate investigation of new glaucoma neuroprotection therapies. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Mark Christopher
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Pourya Hoseini
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Evan Walker
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - James A Proudfoot
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Christopher Bowd
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Massimo A Fazio
- Callahan Eye Hospital, Heersink School of Medicine, University of Alabama-Birmingham, Birmingham, Alabama
| | - Christopher A Girkin
- Callahan Eye Hospital, Heersink School of Medicine, University of Alabama-Birmingham, Birmingham, Alabama
| | - Carlos Gustavo De Moraes
- Bernard and Shirlee Brown Glaucoma Research Laboratory, Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York
| | - Jeffrey M Liebmann
- Bernard and Shirlee Brown Glaucoma Research Laboratory, Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center, New York, New York
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Armin Schwartzman
- Division of Biostatistics, Herbert Wertheim School of Public Health, University of California, San Diego, California; Halıcıoğlu Data Science Institute, University of California, San Diego, California
| | - Linda M Zangwill
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California
| | - Derek S Welsbie
- Hamilton Glaucoma Center, Shiley Eye Institute, Viterbi Family Department of Ophthalmology, University of California, San Diego, California.
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25
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The Role of MEF2 Transcription Factor Family in Neuronal Survival and Degeneration. Int J Mol Sci 2023; 24:ijms24043120. [PMID: 36834528 PMCID: PMC9963821 DOI: 10.3390/ijms24043120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/15/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
The family of myocyte enhancer factor 2 (MEF2) transcription factors comprises four highly conserved members that play an important role in the nervous system. They appear in precisely defined time frames in the developing brain to turn on and turn off genes affecting growth, pruning and survival of neurons. MEF2s are known to dictate neuronal development, synaptic plasticity and restrict the number of synapses in the hippocampus, thus affecting learning and memory formation. In primary neurons, negative regulation of MEF2 activity by external stimuli or stress conditions is known to induce apoptosis, albeit the pro or antiapoptotic action of MEF2 depends on the neuronal maturation stage. By contrast, enhancement of MEF2 transcriptional activity protects neurons from apoptotic death both in vitro and in preclinical models of neurodegenerative diseases. A growing body of evidence places this transcription factor in the center of many neuropathologies associated with age-dependent neuronal dysfunctions or gradual but irreversible neuron loss. In this work, we discuss how the altered function of MEF2s during development and in adulthood affecting neuronal survival may be linked to neuropsychiatric disorders.
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26
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Zheng B, Tuszynski MH. Regulation of axonal regeneration after mammalian spinal cord injury. Nat Rev Mol Cell Biol 2023; 24:396-413. [PMID: 36604586 DOI: 10.1038/s41580-022-00562-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2022] [Indexed: 01/06/2023]
Abstract
One hundred years ago, Ramón y Cajal, considered by many as the founder of modern neuroscience, stated that neurons of the adult central nervous system (CNS) are incapable of regenerating. Yet, recent years have seen a tremendous expansion of knowledge in the molecular control of axon regeneration after CNS injury. We now understand that regeneration in the adult CNS is limited by (1) a failure to form cellular or molecular substrates for axon attachment and elongation through the lesion site; (2) environmental factors, including inhibitors of axon growth associated with myelin and the extracellular matrix; (3) astrocyte responses, which can both limit and support axon growth; and (4) intraneuronal mechanisms controlling the establishment of an active cellular growth programme. We discuss these topics together with newly emerging hypotheses, including the surprising finding from transcriptomic analyses of the corticospinal system in mice that neurons revert to an embryonic state after spinal cord injury, which can be sustained to promote regeneration with neural stem cell transplantation. These gains in knowledge are steadily advancing efforts to develop effective treatment strategies for spinal cord injury in humans.
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Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
| | - Mark H Tuszynski
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
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27
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Craig RA, Fox BM, Hu C, Lexa KW, Osipov M, Thottumkara AP, Larhammar M, Miyamoto T, Rana A, Kane LA, Yulyaningsih E, Solanoy H, Nguyen H, Chau R, Earr T, Kajiwara Y, Fleck D, Lucas A, Haddick PCG, Takahashi RH, Tong V, Wang J, Canet MJ, Poda SB, Scearce-Levie K, Srivastava A, Sweeney ZK, Xu M, Zhang R, He J, Lei Y, Zhuo Z, de Vicente J. Discovery of Potent and Selective Dual Leucine Zipper Kinase/Leucine Zipper-Bearing Kinase Inhibitors with Neuroprotective Properties in In Vitro and In Vivo Models of Amyotrophic Lateral Sclerosis. J Med Chem 2022; 65:16290-16312. [PMID: 36469401 DOI: 10.1021/acs.jmedchem.2c01056] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Dual leucine zipper kinase (DLK) and leucine zipper-bearing kinase (LZK) are regulators of neuronal degeneration and axon growth. Therefore, there is a considerable interest in developing DLK/LZK inhibitors for neurodegenerative diseases. Herein, we use ligand- and structure-based drug design approaches for identifying novel amino-pyrazine inhibitors of DLK/LZK. DN-1289 (14), a potent and selective dual DLK/LZK inhibitor, demonstrated excellent in vivo plasma half-life across species and is anticipated to freely penetrate the central nervous system with no brain impairment based on in vivo rodent pharmacokinetic studies and human in vitro transporter data. Proximal target engagement and disease relevant pathway biomarkers were also favorably regulated in an in vivo model of amyotrophic lateral sclerosis.
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Affiliation(s)
- Robert A Craig
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Brian M Fox
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Cheng Hu
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Katrina W Lexa
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Maksim Osipov
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Arun P Thottumkara
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Martin Larhammar
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Takashi Miyamoto
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Anil Rana
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Lesley A Kane
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Ernie Yulyaningsih
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Hilda Solanoy
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Hoang Nguyen
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Roni Chau
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Timothy Earr
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Yuji Kajiwara
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Daniel Fleck
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Anthony Lucas
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Patrick C G Haddick
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Ryan H Takahashi
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Vincent Tong
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Jing Wang
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Mark J Canet
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Suresh B Poda
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Kimberly Scearce-Levie
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Ankita Srivastava
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Zachary K Sweeney
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
| | - Musheng Xu
- Department of Chemistry, WuXi AppTec Co., Ltd., 168 Nanhai Road, 10th Avenue, Tianjin TEDA, Tianjin 300457, China
| | - Rui Zhang
- Department of Chemistry, WuXi AppTec Co., Ltd., 168 Nanhai Road, 10th Avenue, Tianjin TEDA, Tianjin 300457, China
| | - Jianrong He
- Department of Chemistry, WuXi AppTec Co., Ltd., 168 Nanhai Road, 10th Avenue, Tianjin TEDA, Tianjin 300457, China
| | - Yanan Lei
- Department of Chemistry, WuXi AppTec Co., Ltd., 168 Nanhai Road, 10th Avenue, Tianjin TEDA, Tianjin 300457, China
| | - Zheng Zhuo
- Department of Chemistry, WuXi AppTec Co., Ltd., 168 Nanhai Road, 10th Avenue, Tianjin TEDA, Tianjin 300457, China
| | - Javier de Vicente
- Denali Therapeutics Inc., 161 Oyster Point Blvd., South San Francisco, California 94080, United States
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28
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Intrinsic heterogeneity in axon regeneration. Biochem Soc Trans 2022; 50:1753-1762. [DOI: 10.1042/bst20220624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/01/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
The nervous system is composed of a variety of neurons and glial cells with different morphology and functions. In the mammalian peripheral nervous system (PNS) or the lower vertebrate central nervous system (CNS), most neurons can regenerate extensively after axotomy, while the neurons in the mammalian CNS possess only limited regenerative ability. This heterogeneity is common within and across species. The studies about the transcriptomes after nerve injury in different animal models have revealed a series of molecular and cellular events that occurred in neurons after axotomy. However, responses of various types of neurons located in different positions of individuals were different remarkably. Thus, researchers aim to find the key factors that are conducive to regeneration, so as to provide the molecular basis for solving the regeneration difficulties after CNS injury. Here we review the heterogeneity of axonal regeneration among different cell subtypes in different animal models or the same organ, emphasizing the importance of comparative studies within and across species.
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29
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Noro T, Shah SH, Yin Y, Kawaguchi R, Yokota S, Chang KC, Madaan A, Sun C, Coppola G, Geschwind D, Benowitz LI, Goldberg JL. Elk-1 regulates retinal ganglion cell axon regeneration after injury. Sci Rep 2022; 12:17446. [PMID: 36261683 PMCID: PMC9581912 DOI: 10.1038/s41598-022-21767-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 09/30/2022] [Indexed: 01/12/2023] Open
Abstract
Adult central nervous system (CNS) axons fail to regenerate after injury, and master regulators of the regenerative program remain to be identified. We analyzed the transcriptomes of retinal ganglion cells (RGCs) at 1 and 5 days after optic nerve injury with and without a cocktail of strongly pro-regenerative factors to discover genes that regulate survival and regeneration. We used advanced bioinformatic analysis to identify the top transcriptional regulators of upstream genes and cross-referenced these with the regulators upstream of genes differentially expressed between embryonic RGCs that exhibit robust axon growth vs. postnatal RGCs where this potential has been lost. We established the transcriptional activator Elk-1 as the top regulator of RGC gene expression associated with axon outgrowth in both models. We demonstrate that Elk-1 is necessary and sufficient to promote RGC neuroprotection and regeneration in vivo, and is enhanced by manipulating specific phosphorylation sites. Finally, we co-manipulated Elk-1, PTEN, and REST, another transcription factor discovered in our analysis, and found Elk-1 to be downstream of PTEN and inhibited by REST in the survival and axon regenerative pathway in RGCs. These results uncover the basic mechanisms of regulation of survival and axon growth and reveal a novel, potent therapeutic strategy to promote neuroprotection and regeneration in the adult CNS.
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Affiliation(s)
- Takahiko Noro
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
- Department of Ophthalmology, Jikei University School of Medicine, Tokyo, Japan
| | - Sahil H Shah
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA.
- Medical Scientist Training Program, University of California San Diego, La Jolla, CA, USA.
| | - Yuqin Yin
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Riki Kawaguchi
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Satoshi Yokota
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
- Kobe City Eye Hospital, Kobe, Hyogo, Japan
| | - Kun-Che Chang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Ankush Madaan
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
| | - Catalina Sun
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
| | - Giovanni Coppola
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Daniel Geschwind
- Departments of Neurology and Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Larry I Benowitz
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, 1651 Page Mill Rd, Palo Alto, CA, 94034, USA
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Das A, Imanishi Y. Drug Discovery Strategies for Inherited Retinal Degenerations. BIOLOGY 2022; 11:1338. [PMID: 36138817 PMCID: PMC9495580 DOI: 10.3390/biology11091338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 09/07/2022] [Indexed: 12/03/2022]
Abstract
Inherited retinal degeneration is a group of blinding disorders afflicting more than 1 in 4000 worldwide. These disorders frequently cause the death of photoreceptor cells or retinal ganglion cells. In a subset of these disorders, photoreceptor cell death is a secondary consequence of retinal pigment epithelial cell dysfunction or degeneration. This manuscript reviews current efforts in identifying targets and developing small molecule-based therapies for these devastating neuronal degenerations, for which no cures exist. Photoreceptors and retinal ganglion cells are metabolically demanding owing to their unique structures and functional properties. Modulations of metabolic pathways, which are disrupted in most inherited retinal degenerations, serve as promising therapeutic strategies. In monogenic disorders, great insights were previously obtained regarding targets associated with the defective pathways, including phototransduction, visual cycle, and mitophagy. In addition to these target-based drug discoveries, we will discuss how phenotypic screening can be harnessed to discover beneficial molecules without prior knowledge of their mechanisms of action. Because of major anatomical and biological differences, it has frequently been challenging to model human inherited retinal degeneration conditions using small animals such as rodents. Recent advances in stem cell-based techniques are opening new avenues to obtain pure populations of human retinal ganglion cells and retinal organoids with photoreceptor cells. We will discuss concurrent ideas of utilizing stem-cell-based disease models for drug discovery and preclinical development.
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Affiliation(s)
- Arupratan Das
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Yoshikazu Imanishi
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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31
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Wong KA, Benowitz LI. Retinal Ganglion Cell Survival and Axon Regeneration after Optic Nerve Injury: Role of Inflammation and Other Factors. Int J Mol Sci 2022; 23:ijms231710179. [PMID: 36077577 PMCID: PMC9456227 DOI: 10.3390/ijms231710179] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/29/2022] [Accepted: 09/02/2022] [Indexed: 11/24/2022] Open
Abstract
The optic nerve, like most pathways in the mature central nervous system, cannot regenerate if injured, and within days, retinal ganglion cells (RGCs), the neurons that extend axons through the optic nerve, begin to die. Thus, there are few clinical options to improve vision after traumatic or ischemic optic nerve injury or in neurodegenerative diseases such as glaucoma, dominant optic neuropathy, or optic pathway gliomas. Research over the past two decades has identified several strategies to enable RGCs to regenerate axons the entire length of the optic nerve, in some cases leading to modest reinnervation of di- and mesencephalic visual relay centers. This review primarily focuses on the role of the innate immune system in improving RGC survival and axon regeneration, and its synergy with manipulations of signal transduction pathways, transcription factors, and cell-extrinsic suppressors of axon growth. Research in this field provides hope that clinically effective strategies to improve vision in patients with currently untreatable losses could become a reality in 5-10 years.
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Affiliation(s)
- Kimberly A. Wong
- Department of Neurosurgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- Correspondence: (K.A.W.); (L.I.B.)
| | - Larry I. Benowitz
- Department of Neurosurgery, Boston Children’s Hospital and Harvard Medical School, Boston, MA 02115, USA
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
- Correspondence: (K.A.W.); (L.I.B.)
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32
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Alexandris AS, Ryu J, Rajbhandari L, Harlan R, McKenney J, Wang Y, Aja S, Graham D, Venkatesan A, Koliatsos VE. Protective effects of NAMPT or MAPK inhibitors and NaR on Wallerian degeneration of mammalian axons. Neurobiol Dis 2022; 171:105808. [PMID: 35779777 PMCID: PMC10621467 DOI: 10.1016/j.nbd.2022.105808] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/14/2022] [Accepted: 06/25/2022] [Indexed: 01/23/2023] Open
Abstract
Wallerian degeneration (WD) is a conserved axonal self-destruction program implicated in several neurological diseases. WD is driven by the degradation of the NAD+ synthesizing enzyme NMNAT2, the buildup of its substrate NMN, and the activation of the NAD+ degrading SARM1, eventually leading to axonal fragmentation. The regulation and amenability of these events to therapeutic interventions remain unclear. Here we explored pharmacological strategies that modulate NMN and NAD+ metabolism, namely the inhibition of the NMN-synthesizing enzyme NAMPT, activation of the nicotinic acid riboside (NaR) salvage pathway and inhibition of the NMNAT2-degrading DLK MAPK pathway in an axotomy model in vitro. Results show that NAMPT and DLK inhibition cause a significant but time-dependent delay of WD. These time-dependent effects are related to NMNAT2 degradation and changes in NMN and NAD+ levels. Supplementation of NAMPT inhibition with NaR has an enhanced effect that does not depend on timing of intervention and leads to robust protection up to 4 days. Additional DLK inhibition extends this even further to 6 days. Metabolite analyses reveal complex effects indicating that NAMPT and MAPK inhibition act by reducing NMN levels, ameliorating NAD+ loss and suppressing SARM1 activity. Finally, the axonal NAD+/NMN ratio is highly predictive of cADPR levels, extending previous cell-free evidence on the allosteric regulation of SARM1. Our findings establish a window of axon protection extending several hours following injury. Moreover, we show prolonged protection by mixed treatments combining MAPK and NAMPT inhibition that proceed via complex effects on NAD+ metabolism and inhibition of SARM1.
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Affiliation(s)
| | - Jiwon Ryu
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Labchan Rajbhandari
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Robert Harlan
- The Molecular Determinants Center and Core, Johns Hopkins All Children's Hospital, St. Petersburg, FL, USA
| | - James McKenney
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yiqing Wang
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Susan Aja
- The Molecular Determinants Center and Core, Johns Hopkins All Children's Hospital, St. Petersburg, FL, USA
| | - David Graham
- The Molecular Determinants Center and Core, Johns Hopkins All Children's Hospital, St. Petersburg, FL, USA
| | - Arun Venkatesan
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Vassilis E Koliatsos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Johnson TV, Polo AD, Sahel JA, Schuman JS. Neuroprotection, Neuroenhancement, and Neuroregeneration of the Retina and Optic Nerve. OPHTHALMOLOGY SCIENCE 2022; 2:100216. [PMID: 36245765 PMCID: PMC9559091 DOI: 10.1016/j.xops.2022.100216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Tsai NY, Welsbie DS, Duan X. Live, die, or regenerate? New insights from multi-omic analyses. Neuron 2022; 110:2516-2519. [PMID: 35981522 PMCID: PMC9521179 DOI: 10.1016/j.neuron.2022.07.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this issue of Neuron, three studies establish new strategies to uncover mediators of retinal neuroprotection and optic nerve regeneration. Tian et al. (2022) carry out a multi-omics screen and identify transcriptional regulators of axon injury signaling leading to cell death; Jacobi et al. (2022) and Li et al. (2022) combine retrograde tracing and single-cell RNA-seq (scRNA-seq) to uncover molecular targets for axon regeneration.
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Affiliation(s)
- Nicole Y Tsai
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
| | - Derek S Welsbie
- Department of Ophthalmology, University of California San Diego, San Diego, CA, USA
| | - Xin Duan
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA.
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Adula KP, Shorey M, Chauhan V, Nassman K, Chen SF, Rolls MM, Sagasti A. The MAP3Ks DLK and LZK Direct Diverse Responses to Axon Damage in Zebrafish Peripheral Neurons. J Neurosci 2022; 42:6195-6210. [PMID: 35840323 PMCID: PMC9374156 DOI: 10.1523/jneurosci.1395-21.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 06/14/2022] [Accepted: 06/27/2022] [Indexed: 11/21/2022] Open
Abstract
Mitogen-activated protein kinase kinase kinases (MAP3Ks) dual leucine kinase (DLK) and leucine zipper kinase (LZK) are essential mediators of axon damage responses, but their responses are varied, complex, and incompletely understood. To characterize their functions in axon injury, we generated zebrafish mutants of each gene, labeled motor neurons (MNs) and touch-sensing neurons in live zebrafish, precisely cut their axons with a laser, and assessed the ability of mutant axons to regenerate in larvae, before sex is apparent in zebrafish. DLK and LZK were required redundantly and cell autonomously for axon regeneration in MNs but not in larval Rohon-Beard (RB) or adult dorsal root ganglion (DRG) sensory neurons. Surprisingly, in dlk lzk double mutants, the spared branches of wounded RB axons grew excessively, suggesting that these kinases inhibit regenerative sprouting in damaged axons. Uninjured trigeminal sensory axons also grew excessively in mutants when neighboring neurons were ablated, indicating that these MAP3Ks are general inhibitors of sensory axon growth. These results demonstrate that zebrafish DLK and LZK promote diverse injury responses, depending on the neuronal cell identity and type of axonal injury.SIGNIFICANCE STATEMENT The MAP3Ks DLK and LZK are damage sensors that promote diverse outcomes to neuronal injury, including axon regeneration. Understanding their context-specific functions is a prerequisite to considering these kinases as therapeutic targets. To investigate DLK and LZK cell-type-specific functions, we created zebrafish mutants in each gene. Using mosaic cell labeling and precise laser injury we found that both proteins were required for axon regeneration in motor neurons but, unexpectedly, were not required for axon regeneration in Rohon-Beard or DRG sensory neurons and negatively regulated sprouting in the spared axons of touch-sensing neurons. These findings emphasize that animals have evolved distinct mechanisms to regulate injury site regeneration and collateral sprouting, and identify differential roles for DLK and LZK in these processes.
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Affiliation(s)
- Kadidia Pemba Adula
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Matthew Shorey
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Vasudha Chauhan
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Khaled Nassman
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Shu-Fan Chen
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095
| | - Melissa M Rolls
- Department of Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802
| | - Alvaro Sagasti
- Molecular, Cell and Developmental Biology Department and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California 90095,
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Tortosa E, Sengupta Ghosh A, Li Q, Wong WR, Hinkle T, Sandoval W, Rose CM, Hoogenraad CC. Stress-induced vesicular assemblies of dual leucine zipper kinase are signaling hubs involved in kinase activation and neurodegeneration. EMBO J 2022; 41:e110155. [PMID: 35611591 PMCID: PMC9289706 DOI: 10.15252/embj.2021110155] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/09/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) drive key signaling cascades during neuronal survival and degeneration. The localization of kinases to specific subcellular compartments is a critical mechanism to locally control signaling activity and specificity upon stimulation. However, how MAPK signaling components tightly control their localization remains largely unknown. Here, we systematically analyzed the phosphorylation and membrane localization of all MAPKs expressed in dorsal root ganglia (DRG) neurons, under control and stress conditions. We found that MAP3K12/dual leucine zipper kinase (DLK) becomes phosphorylated and palmitoylated, and it is recruited to sphingomyelin-rich vesicles upon stress. Stress-induced DLK vesicle recruitment is essential for kinase activation; blocking DLK-membrane interaction inhibits downstream signaling, while DLK recruitment to ectopic subcellular structures is sufficient to induce kinase activation. We show that the localization of DLK to newly formed vesicles is essential for local signaling. Inhibition of membrane internalization blocks DLK activation and protects against neurodegeneration in DRG neurons. These data establish vesicular assemblies as dynamically regulated platforms for DLK signaling during neuronal stress responses.
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Affiliation(s)
- Elena Tortosa
- Department of Neuroscience, Genentech, Inc., South San Francisco, CA, USA
| | | | - Qingling Li
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Weng Ruh Wong
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Trent Hinkle
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Wendy Sandoval
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
| | - Christopher M Rose
- Department of Microchemistry, Proteomics and Lipidomics, Genentech, Inc., South San Francisco, CA, USA
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Saikia JM, Chavez-Martinez CL, Kim ND, Allibhoy S, Kim HJ, Simonyan L, Smadi S, Tsai KM, Romaus-Sanjurjo D, Jin Y, Zheng B. A Critical Role for DLK and LZK in Axonal Repair in the Mammalian Spinal Cord. J Neurosci 2022; 42:3716-3732. [PMID: 35361703 PMCID: PMC9087816 DOI: 10.1523/jneurosci.2495-21.2022] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/23/2022] [Accepted: 03/24/2022] [Indexed: 11/21/2022] Open
Abstract
The limited ability for axonal repair after spinal cord injury underlies long-term functional impairment. Dual leucine-zipper kinase [DLK; MAP kinase kinase kinase 12; MAP3K12] is an evolutionarily conserved MAP3K implicated in neuronal injury signaling from Caenorhabditis elegans to mammals. However, whether DLK or its close homolog leucine zipper kinase (LZK; MAP3K13) regulates axonal repair in the mammalian spinal cord remains unknown. Here, we assess the role of endogenous DLK and LZK in the regeneration and compensatory sprouting of corticospinal tract (CST) axons in mice of both sexes with genetic analyses in a regeneration competent background provided by PTEN deletion. We found that inducible neuronal deletion of both DLK and LZK, but not either kinase alone, abolishes PTEN deletion-induced regeneration and sprouting of CST axons, and reduces naturally-occurring axon sprouting after injury. Thus, DLK/LZK-mediated injury signaling operates not only in injured neurons to regulate regeneration, but also unexpectedly in uninjured neurons to regulate sprouting. Deleting DLK and LZK does not interfere with PTEN/mTOR signaling, indicating that injury signaling and regenerative competence are independently controlled. Together with our previous study implicating LZK in astrocytic reactivity and scar formation, these data illustrate the multicellular function of this pair of MAP3Ks in both neurons and glia in the injury response of the mammalian spinal cord.SIGNIFICANCE STATEMENT Functional recovery after spinal cord injury is limited because of a lack of axonal repair in the mammalian CNS. Dual leucine-zipper kinase (DLK) and leucine zipper kinase (LZK) are two closely related protein kinases that have emerged as regulators of neuronal responses to injury. However, their role in axonal repair in the mammalian spinal cord has not been described. Here, we show that DLK and LZK together play critical roles in axonal repair in the mammalian spinal cord, validating them as potential targets to promote repair and recovery after spinal cord injury. In addition to regulating axonal regeneration from injured neurons, both kinases also regulate compensatory axonal growth from uninjured neurons, indicating a more pervasive role in CNS repair than originally anticipated.
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Affiliation(s)
- Junmi M Saikia
- Department of Neurosciences, School of Medicine
- Neurosciences Graduate Program
| | | | - Noah D Kim
- Department of Neurosciences, School of Medicine
| | | | - Hugo J Kim
- Department of Neurosciences, School of Medicine
| | | | | | | | | | - Yishi Jin
- Department of Neurosciences, School of Medicine
- Department of Neurobiology, School of Biological Sciences
- Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine
- VA San Diego Healthcare System Research Service, San Diego, California 92161
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Tavakoli S, Puranen J, Bahrpeyma S, Lautala VE, Karumo S, Lajunen T, del Amo EM, Ruponen M, Urtti A. Liposomal sunitinib for ocular drug delivery: a potential treatment for choroidal neovascularization. Int J Pharm 2022; 620:121725. [DOI: 10.1016/j.ijpharm.2022.121725] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 11/25/2022]
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Niu J, Holland SM, Ketschek A, Collura KM, Hesketh NL, Hayashi T, Gallo G, Thomas GM. Palmitoylation couples the kinases DLK and JNK3 to facilitate prodegenerative axon-to-soma signaling. Sci Signal 2022; 15:eabh2674. [PMID: 35349303 DOI: 10.1126/scisignal.abh2674] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dual leucine-zipper kinase (DLK; a MAP3K) mediates neuronal responses to diverse injuries and insults through the c-Jun N-terminal kinase (JNK) family of mitogen-activated protein kinases (MAPKs). Here, we identified two ways through which DLK is coupled to the neural-specific isoform JNK3 to control prodegenerative signaling. JNK3 catalyzed positive feedback phosphorylation of DLK that further activated DLK and locked the DLK-JNK3 module in a highly active state. Neither homologous MAP3Ks nor a homologous MAPK could support this positive feedback loop. Unlike the related JNK1 isoform JNK2 and JNK3 promote prodegenerative axon-to-soma signaling and were endogenously palmitoylated. Moreover, palmitoylation targeted both DLK and JNK3 to the same axonal vesicles, and JNK3 palmitoylation was essential for axonal retrograde signaling in response to optic nerve crush injury in vivo. These findings provide previously unappreciated insights into DLK-JNK signaling relevant to neuropathological conditions and answer long-standing questions regarding the selective prodegenerative roles of JNK2 and JNK3.
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Affiliation(s)
- Jingwen Niu
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Sabrina M Holland
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Andrea Ketschek
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Kaitlin M Collura
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Natasha L Hesketh
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Takashi Hayashi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central6 (6-10), 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Gianluca Gallo
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA.,Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, 3500 N. Broad St., Philadelphia, PA 19140, USA
| | - Gareth M Thomas
- Shriners Hospitals Pediatric Research Center (Center for Neurorehabilitation and Neural Repair), Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA.,Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, 3500 N. Broad St., Philadelphia, PA 19140, USA
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Varadarajan SG, Hunyara JL, Hamilton NR, Kolodkin AL, Huberman AD. Central nervous system regeneration. Cell 2022; 185:77-94. [PMID: 34995518 PMCID: PMC10896592 DOI: 10.1016/j.cell.2021.10.029] [Citation(s) in RCA: 84] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 02/06/2023]
Abstract
Neurons of the mammalian central nervous system fail to regenerate. Substantial progress has been made toward identifying the cellular and molecular mechanisms that underlie regenerative failure and how altering those pathways can promote cell survival and/or axon regeneration. Here, we summarize those findings while comparing the regenerative process in the central versus the peripheral nervous system. We also highlight studies that advance our understanding of the mechanisms underlying neural degeneration in response to injury, as many of these mechanisms represent primary targets for restoring functional neural circuits.
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Affiliation(s)
| | - John L Hunyara
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natalie R Hamilton
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Andrew D Huberman
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA.
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41
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Chen J, Li H, Yang C, He Y, Arai T, Huang Q, Liu X, Miao L. Citrus Naringenin Increases Neuron Survival in Optic Nerve Crush Injury Model by Inhibiting JNK-JUN Pathway. Int J Mol Sci 2021; 23:385. [PMID: 35008811 PMCID: PMC8745540 DOI: 10.3390/ijms23010385] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 11/24/2022] Open
Abstract
Traumatic nerve injury activates cell stress pathways, resulting in neuronal death and loss of vital neural functions. To date, there are no available neuroprotectants for the treatment of traumatic neural injuries. Here, we studied three important flavanones of citrus components, in vitro and in vivo, to reveal their roles in inhibiting the JNK (c-Jun N-terminal kinase)-JUN pathway and their neuroprotective effects in the optic nerve crush injury model, a kind of traumatic nerve injury in the central nervous system. Results showed that both neural injury in vivo and cell stress in vitro activated the JNK-JUN pathway and increased JUN phosphorylation. We also demonstrated that naringenin treatment completely inhibited stress-induced JUN phosphorylation in cultured cells, whereas nobiletin and hesperidin only partially inhibited JUN phosphorylation. Neuroprotection studies in optic nerve crush injury mouse models revealed that naringenin treatment increased the survival of retinal ganglion cells after traumatic optic nerve injury, while the other two components had no neuroprotective effect. The neuroprotection effect of naringenin was due to the inhibition of JUN phosphorylation in crush-injured retinal ganglion cells. Therefore, the citrus component naringenin provides neuroprotection through the inhibition of the JNK-JUN pathway by inhibiting JUN phosphorylation, indicating the potential application of citrus chemical components in the clinical therapy of traumatic optic nerve injuries.
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Affiliation(s)
- Jie Chen
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Hui Li
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Changming Yang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Yinjia He
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Tatsuo Arai
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Qiang Huang
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xiaodong Liu
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing 100029, China; (H.L.); (Y.H.)
| | - Linqing Miao
- Beijing Advanced Innovation Center for Intelligent Robots and Systems, Beijing Institute of Technology, Beijing 100081, China; (J.C.); (C.Y.); (T.A.); (Q.H.)
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
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Kingston R, Amin D, Misra S, Gross JM, Kuwajima T. Serotonin transporter-mediated molecular axis regulates regional retinal ganglion cell vulnerability and axon regeneration after nerve injury. PLoS Genet 2021; 17:e1009885. [PMID: 34735454 PMCID: PMC8594818 DOI: 10.1371/journal.pgen.1009885] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 11/16/2021] [Accepted: 10/17/2021] [Indexed: 11/19/2022] Open
Abstract
Molecular insights into the selective vulnerability of retinal ganglion cells (RGCs) in optic neuropathies and after ocular trauma can lead to the development of novel therapeutic strategies aimed at preserving RGCs. However, little is known about what molecular contexts determine RGC susceptibility. In this study, we show the molecular mechanisms underlying the regional differential vulnerability of RGCs after optic nerve injury. We identified RGCs in the mouse peripheral ventrotemporal (VT) retina as the earliest population of RGCs susceptible to optic nerve injury. Mechanistically, the serotonin transporter (SERT) is upregulated on VT axons after injury. Utilizing SERT-deficient mice, loss of SERT attenuated VT RGC death and led to robust retinal axon regeneration. Integrin β3, a factor mediating SERT-induced functions in other systems, is also upregulated in RGCs and axons after injury, and loss of integrin β3 led to VT RGC protection and axon regeneration. Finally, RNA sequencing analyses revealed that loss of SERT significantly altered molecular signatures in the VT retina after optic nerve injury, including expression of the transmembrane protein, Gpnmb. GPNMB is rapidly downregulated in wild-type, but not SERT- or integrin β3-deficient VT RGCs after injury, and maintaining expression of GPNMB in RGCs via AAV2 viruses even after injury promoted VT RGC survival and axon regeneration. Taken together, our findings demonstrate that the SERT-integrin β3-GPNMB molecular axis mediates selective RGC vulnerability and axon regeneration after optic nerve injury.
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Affiliation(s)
- Rody Kingston
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, Pittsburgh, Pennsylvania, United States of America
| | - Dwarkesh Amin
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, Pittsburgh, Pennsylvania, United States of America
| | - Sneha Misra
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, Pittsburgh, Pennsylvania, United States of America
| | - Jeffrey M. Gross
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, Pittsburgh, Pennsylvania, United States of America
- Department of Developmental Biology, The McGowan Institute for Regenerative Medicine, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Takaaki Kuwajima
- Department of Ophthalmology, The Louis J. Fox Center for Vision Restoration, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Morejon-Garcia P, Keren B, Marcos-Alcalde I, Gomez-Puertas P, Mochel F, Lazo PA. Dysfunctional Homozygous VRK1-D263G Variant Impairs the Assembly of Cajal Bodies and DNA Damage Response in Hereditary Spastic Paraplegia. NEUROLOGY-GENETICS 2021; 7:e624. [PMID: 34504951 PMCID: PMC8422991 DOI: 10.1212/nxg.0000000000000624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 07/26/2021] [Indexed: 11/29/2022]
Abstract
Background and Objectives To conduct a genetic and molecular functional study of a family with members affected of hereditary spastic paraplegia (HSP) of unknown origin and carrying a novel pathogenic vaccinia-related kinase 1 (VRK1) variant. Methods Whole-exome sequencing was performed in 2 patients, and their parents diagnosed with HSP. The novel VRK1 variant was detected by whole-exome sequencing, molecularly modeled and biochemically characterized in kinase assays. Functionally, we studied the role of this VRK1 variant in DNA damage response and its effect on the assembly of Cajal bodies (CBs). Results We have identified a very rare homozygous variant VRK1-D263G with a neurologic phenotype associated with HSP and moderate intellectual disability. The molecular modeling of this VRK1 variant protein predicted an alteration in the folding of a loop that interferes with the access to the kinase catalytic site. The VRK1-D263G variant is kinase inactive and does not phosphorylate histones H2AX and H3, transcription factors activating transcription factor 2 and p53, coilin needed for assembly of CBs, and p53 binding protein 1, a DNA repair protein. Functionally, this VRK1 variant protein impairs CB formation and the DNA damage response. Discussion This report expands the neurologic spectrum of neuromotor syndromes associated with a new and rare VRK1 variant, representing a novel pathogenic participant in complicated HSP and demonstrates that CBs and the DNA damage response are impaired in these patients.
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Affiliation(s)
- Patricia Morejon-Garcia
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Boris Keren
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Iñigo Marcos-Alcalde
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Paulino Gomez-Puertas
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Fanny Mochel
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
| | - Pedro A Lazo
- Molecular Mechanisms of Cancer Program (P.M.-G., P.A.L.), Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Salamanca; Instituto de Investigación Biomédica de Salamanca (IBSAL) (P.M.-G., P.A.L.), Hospital Universitario de Salamanca, Spain; Genetics Department (B.K.), La Pitié-Salpêtrière Hospital, APHP. Sorbonne Université, Paris, France; Molecular Modelling Group (I.M.-A.), Centro de Biología Molecular "Severo Ochoa". CSIC - Universidad Autónoma de Madrid, Spain; Biosciences Research Institute (I.M.-A., P.G.-P.), School of Experimental Sciences, Universidad Francisco de Vitoria, Madrid, Spain; and Sorbonne Université - Université Pierre et Marie Curie (F.M.), Institut du Cerveau et de la Moelle épinière, INSERM U-1127, CNRS-UMR 7225, Paris, France
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Fague L, Liu YA, Marsh-Armstrong N. The basic science of optic nerve regeneration. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1276. [PMID: 34532413 PMCID: PMC8421956 DOI: 10.21037/atm-20-5351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/15/2021] [Indexed: 12/25/2022]
Abstract
Diverse insults to the optic nerve result in partial to total vision loss as the axons of retinal ganglion cells are destroyed. In glaucoma, axons are injured at the optic nerve head; in other optic neuropathies, axons can be damaged along the entire visual pathway. In all cases, as mammals cannot regenerate injured central nervous system cells, once the axons are lost, vision loss is irreversible. However, much has been learned about how retinal ganglion cells respond to axon injuries, and many of these crucial discoveries offer hope for future regenerative therapies. Here we review the current understanding regarding the temporal progression of axonal degeneration. We summarize known survival and regenerative mechanisms in mammals, including specific signaling pathways, key transcription factors, and reprogramming genes. We cover mechanisms intrinsic to retinal ganglion cells as well as their interactions with myeloid and glial cell populations in the retina and optic nerve that affect survival and regeneration. Finally, we highlight some non-mammalian species that are able to regenerate their retinal ganglion cell axons after injury, as understanding these successful regenerative responses may be essential to the rational design of future clinical interventions to regrow the optic nerve. In the end, a combination of many different molecular and cellular interventions will likely be the only way to achieve functional recovery of vision and restore quality of life to millions of patients around the world.
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Affiliation(s)
- Lindsay Fague
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Yin Allison Liu
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Nicholas Marsh-Armstrong
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
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Do JL, Allahwerdy S, David RCC, Weinreb RN, Tuszynski MH, Welsbie DS. Optic Nerve Engraftment of Neural Stem Cells. Invest Ophthalmol Vis Sci 2021; 62:30. [PMID: 34283208 PMCID: PMC8300061 DOI: 10.1167/iovs.62.9.30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Purpose To evaluate the integrative potential of neural stem cells (NSCs) with the visual system and characterize effects on the survival and axonal regeneration of axotomized retinal ganglion cells (RGCs). Methods For in vitro studies, primary, postnatal rat RGCs were directly cocultured with human NSCs or cultured in NSC-conditioned media before their survival and neurite outgrowth were assessed. For in vivo studies, human NSCs were transplanted into the transected rat optic nerve, and immunohistology of the retina and optic nerve was performed to evaluate RGC survival, RGC axon regeneration, and NSC integration with the injured visual system. Results Increased neurite outgrowth was observed in RGCs directly cocultured with NSCs. NSC-conditioned media demonstrated a dose-dependent effect on RGC survival and neurite outgrowth in culture. NSCs grafted into the lesioned optic nerve modestly improved RGC survival following an optic nerve transection (593 ± 164 RGCs/mm2 vs. 199 ± 58 RGCs/mm2; P < 0.01). Additionally, RGC axonal regeneration following an optic nerve transection was modestly enhanced by NSCs transplanted at the lesion site (61.6 ± 8.5 axons vs. 40.3 ± 9.1 axons, P < 0.05). Transplanted NSCs also differentiated into neurons, received synaptic inputs from regenerating RGC axons, and extended axons along the transected optic nerve to incorporate with the visual system. Conclusions Human NSCs promote the modest survival and axonal regeneration of axotomized RGCs that is partially mediated by diffusible NSC-derived factors. Additionally, NSCs integrate with the injured optic nerve and have the potential to form neuronal relays to restore retinofugal connections.
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Affiliation(s)
- Jiun L Do
- Hamilton Glaucoma Center, Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Salam Allahwerdy
- Hamilton Glaucoma Center, Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Ryan Caezar C David
- Hamilton Glaucoma Center, Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Robert N Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
| | - Mark H Tuszynski
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States.,Veterans Administration Medical Center, San Diego, California, United States
| | - Derek S Welsbie
- Hamilton Glaucoma Center, Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, California, United States
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Ren X, Ju Y, Wang C, Wei R, Sun H, Zhang Q. MARCKS on Tumor-Associated Macrophages is Correlated with Immune Infiltrates and Poor Prognosis in Hepatocellular Carcinoma. Cancer Invest 2021; 39:756-768. [PMID: 34279157 DOI: 10.1080/07357907.2021.1950757] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Hepatocellular carcinoma is the fourth most common cause of cancer-related death. However, the cross-talk between tumor immune microenvironment and hepatocellular carcinoma (HCC) remains unclear. MATERIAL AND METHODS We analyzed the expression of miR-143-3p in exosomes from different HCC cell lines. Differentially expressed genes (DEGs) in Tumor-associated macrophages (TAMs) co-cultured with HCC cell lines were overlapped with miR-143-3p target genes. We used the Oncomine, Kaplan-Meier plotter, and The Cancer Genome Atlas (TCGA) databases to assess Myristoylated alanine-rich C-kinase substrate (MARCKS) expression in various types of cancers. The relationship between patient clinicopathological characteristics and MARCKS expression level was identified using the Kaplan-Meier plotter database. Last, we analyzed how MARCKS expression correlated with immune infiltration makers using the TCGA database, Tumor IMmune Estimation Resource (TIMER), and Gene Expression Profiling Interactive Analysis (GEPIA). RESULTS Exosomal miR-143-3p was elevated after IL-6 treatment in the HCC cell line. MARCKS, a target gene of miR-143-3p, was up-regulated in Tumor-associated macrophages co-cultured with high-metastatic-potential HCC cell line. MARCKS expression was identified as significantly correlated with outcome in multiple types of cancer, especially in HCC. High MARCKS expression level was associated with poorer overall survival (OS), Progress-free survival (PFS), and also with patient gender, race, hepatitis virus background, stage, grade, AJCC_T, and vascular invasion. MARCKS was positively associated with levels of T follicular helper cells (TFH) (R = .48, p < .001), T helper type 2 (Th2) cells (R = .47, p < .001), macrophages (R = .41, p ≤ .001), T helper cells (R = .40, p < .001), T helper type 1 (Th1) cells (R = .38, p < .001), T cells (R = .34, p < .001), NK CD56bright cells (R = .34, p < .001) and immature DC (iDC) (R = .33, p < .001), and negatively associated with levels of T helper 17 (Th17) cells. Also, MARCKS may influence the M2 polarization and immune escape. CONCLUSION The present study suggests that MARCKS on TAMs is associated with poor prognosis and immune cell infiltration in HCC.
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Affiliation(s)
- Xudong Ren
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Yanqin Ju
- Department of Stomotology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chaoqun Wang
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Ran Wei
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Haoting Sun
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Quanbao Zhang
- Department of General Surgery, Huashan Hospital, Fudan University, Shanghai, China
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Wang R, Xu Y, Niu C, Gao X, Xu X. A Novel Small Peptide H-KI20 Inhibits Retinal Neovascularization Through the JNK/ATF2 Signaling Pathway. Invest Ophthalmol Vis Sci 2021; 62:16. [PMID: 33439229 PMCID: PMC7814360 DOI: 10.1167/iovs.62.1.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose Abundant evidence has shown benefits of antivascular endothelial growth factor (anti-VEGF) therapies in neovascular eye diseases. However, the high cost, side effects, and inconvenience of frequent injections demand alternative novel drug candidates. This study aimed to analyze antiangiogenic effects of peptide H-KI20 and illustrated signaling mechanisms. Methods Live cell culture and tracing, wound healing assay, and tube formation were performed in human retinal microvascular endothelial cells (HRECs). The chick embryo chorioallantoic membrane and mouse oxygen-induced ischemic retinopathy model were applied to examine the effects of H-KI20 in vivo. The intracellular signaling pathways were examined. Molecular docking and surface plasmon resonance assay were used to validate the direct interaction of H-KI20 and c-Jun N-terminal kinase 2 (JNK2). Results H-KI20 had high penetration ability in vitro and in vivo. It inhibited motility, migration, and tube formation of HRECs, without cytotoxicity, and inhibited angiogenesis in vivo. Furthermore, H-KI20 treatment reduced the phosphorylation level of activating transcription factor 2 (ATF2) stimulated by VEGF via downregulating p-JNK. H-KI20 bound to JNK2 directly with a dissociation constant value of 83.68 µM. The knockdown of ATF2 attenuated VEGF-induced tube formation and decreased the movement speed of HRECs. Conclusions H-KI20 inhibited angiogenesis both in vitro and in vivo. The ratios of p-ATF2/ATF2 and p-JNK/JNK stimulated by VEGF were decreased by H-KI20, and H-KI20 targeted JNK2 directly. In addition, the pivotal role of ATF2 in VEGF-induced retinal neovascularization was elucidated for the first time. Taken together, H-KI20 displays potential for pathological retinal angiogenesis as a sustained and low-toxic peptide.
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Affiliation(s)
- Ruonan Wang
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Preventative Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center/Shanghai Eye Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai General Hospital, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Yi Xu
- Department of Preventative Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center/Shanghai Eye Hospital, Shanghai, China
| | - Chen Niu
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xihui Gao
- MOE/NHC/CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xun Xu
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Preventative Ophthalmology, Shanghai Eye Disease Prevention and Treatment Center/Shanghai Eye Hospital, Shanghai, China.,National Clinical Research Center for Eye Diseases, Shanghai General Hospital, Shanghai, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
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Multifactorial Pathogenic Processes of Retinal Ganglion Cell Degeneration in Glaucoma towards Multi-Target Strategies for Broader Treatment Effects. Cells 2021; 10:cells10061372. [PMID: 34199494 PMCID: PMC8228726 DOI: 10.3390/cells10061372] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/14/2021] [Accepted: 05/29/2021] [Indexed: 02/06/2023] Open
Abstract
Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cell (RGC) somas, degeneration of axons, and loss of synapses at dendrites and axon terminals. Glaucomatous neurodegeneration encompasses multiple triggers, multiple cell types, and multiple molecular pathways through the etiological paths with biomechanical, vascular, metabolic, oxidative, and inflammatory components. As much as intrinsic responses of RGCs themselves, divergent responses and intricate interactions of the surrounding glia also play decisive roles for the cell fate. Seen from a broad perspective, multitarget treatment strategies have a compelling pathophysiological basis to more efficiently manipulate multiple pathogenic processes at multiple injury sites in such a multifactorial neurodegenerative disease. Despite distinct molecular programs for somatic and axonal degeneration, mitochondrial dysfunction and glia-driven neuroinflammation present interdependent processes with widespread impacts in the glaucomatous retina and optic nerve. Since dysfunctional mitochondria stimulate inflammatory responses and proinflammatory mediators impair mitochondria, mitochondrial restoration may be immunomodulatory, while anti-inflammatory treatments protect mitochondria. Manipulation of these converging routes may thus allow a unified treatment strategy to protect RGC axons, somas, and synapses. This review presents an overview of recent research advancements with emphasis on potential treatment targets to achieve the best treatment efficacy to preserve visual function in glaucoma.
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Wang J, Struebing FL, Geisert EE. Commonalities of optic nerve injury and glaucoma-induced neurodegeneration: Insights from transcriptome-wide studies. Exp Eye Res 2021; 207:108571. [PMID: 33844961 PMCID: PMC9890784 DOI: 10.1016/j.exer.2021.108571] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/28/2021] [Accepted: 04/02/2021] [Indexed: 02/03/2023]
Abstract
Glaucoma is a collection of diseases that lead to an irreversible vision loss due to damage of retinal ganglion cells (RGCs). Although the underlying events leading to RGC death are not fully understood, recent research efforts are beginning to define the genetic changes that play a critical role in the initiation and progression of glaucomatous injury and RGC death. Several genetic and experimental animal models have been developed to mimic glaucomatous neurodegeneration. These models differ in many respects but all result in the loss of RGCs. Assessing transcriptional changes across different models could provide a more complete perspective on the molecular drivers of RGC degeneration. For the past several decades, changes in the retinal transcriptome during neurodegeneration process were defined using microarray methods, RNA sequencing and now single cell RNA sequencing. It is understood that these methods have strengths and weaknesses due to technical differences and variations in the analytical tools used. In this review, we focus on the use of transcriptome-wide expression profiling of the changes occurring as RGCs are lost across different glaucoma models. Commonalities of optic nerve crush and glaucoma-induced neurodegeneration are identified and discussed.
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Affiliation(s)
- Jiaxing Wang
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Felix L. Struebing
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Germany,Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Eldon E. Geisert
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA,Corresponding author: (E.E. Geisert)
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Ion-Complex Microcrystal Formulation Provides Sustained Delivery of a Multimodal Kinase Inhibitor from the Subconjunctival Space for Protection of Retinal Ganglion Cells. Pharmaceutics 2021; 13:pharmaceutics13050647. [PMID: 34062883 PMCID: PMC8147274 DOI: 10.3390/pharmaceutics13050647] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 02/07/2023] Open
Abstract
Glaucoma is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is one of the major risk factors for glaucoma onset and progression, and available pharmaceutical interventions are exclusively targeted at IOP lowering. However, degeneration of retinal ganglion cells (RGCs) may continue to progress despite extensive lowering of IOP. A complementary strategy to IOP reduction is the use of neuroprotective agents that interrupt the process of cell death by mechanisms independent of IOP. Here, we describe an ion complexation approach for formulating microcrystals containing ~50% loading of a protein kinase inhibitor, sunitinib, to enhance survival of RGCs with subconjunctival injection. A single subconjunctival injection of sunitinib-pamoate complex (SPC) microcrystals provided 20 weeks of sustained retina drug levels, leading to neuroprotection in a rat model of optic nerve injury. Furthermore, subconjunctival injection of SPC microcrystals also led to therapeutic effects in a rat model of corneal neovascularization. Importantly, therapeutically relevant retina drug concentrations were achieved with subconjunctival injection of SPC microcrystals in pigs. For a chronic disease such as glaucoma, a formulation that provides sustained therapeutic effects to complement IOP lowering therapies could provide improved disease management and promote patient quality of life.
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