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Niu J, Sanders SS, Jeong HK, Holland SM, Sun Y, Collura KM, Hernandez LM, Huang H, Hayden MR, Smith GM, Hu Y, Jin Y, Thomas GM. Coupled Control of Distal Axon Integrity and Somal Responses to Axonal Damage by the Palmitoyl Acyltransferase ZDHHC17. Cell Rep 2020; 33:108365. [PMID: 33207199 PMCID: PMC7803378 DOI: 10.1016/j.celrep.2020.108365] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 08/28/2020] [Accepted: 10/19/2020] [Indexed: 12/25/2022] Open
Abstract
After optic nerve crush (ONC), the cell bodies and distal axons of most retinal ganglion cells (RGCs) degenerate. RGC somal and distal axon degenerations were previously thought to be controlled by two parallel pathways, involving activation of the kinase dual leucine-zipper kinase (DLK) and loss of the axon survival factor nicotinamide mononucleotide adenylyltransferase-2 (NMNAT2), respectively. Here, we report that palmitoylation of both DLK and NMNAT2 by the palmitoyl acyltransferase ZDHHC17 couples these signals. ZDHHC17-dependent palmitoylation enables DLK-dependent somal degeneration after ONC and also ensures NMNAT-dependent distal axon integrity in healthy optic nerves. We provide evidence that ZDHHC17 also controls survival-versus-degeneration decisions in dorsal root ganglion (DRG) neurons, and we identify conserved motifs in NMNAT2 and DLK that govern their ZDHHC17-dependent regulation. These findings suggest that the control of somal and distal axon integrity should be considered as a single, holistic process, mediated by the concerted action of two palmitoylation-dependent pathways.
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Affiliation(s)
- Jingwen Niu
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Shaun S Sanders
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Hey-Kyeong Jeong
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Sabrina M Holland
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Yue Sun
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kaitlin M Collura
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Luiselys M Hernandez
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Michael R Hayden
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA; Department of Neuroscience, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Gareth M Thomas
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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Peters OM, Lewis EA, Osterloh JM, Weiss A, Salameh JS, Metterville J, Brown RH, Freeman MR. Loss of Sarm1 does not suppress motor neuron degeneration in the SOD1G93A mouse model of amyotrophic lateral sclerosis. Hum Mol Genet 2019; 27:3761-3771. [PMID: 30010873 PMCID: PMC6196650 DOI: 10.1093/hmg/ddy260] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 07/09/2018] [Indexed: 12/14/2022] Open
Abstract
Axon degeneration occurs in all neurodegenerative diseases, but the molecular pathways regulating axon destruction during neurodegeneration are poorly understood. Sterile Alpha and TIR Motif Containing 1 (Sarm1) is an essential component of the prodegenerative pathway driving axon degeneration after axotomy and represents an appealing target for therapeutic intervention in neurological conditions involving axon loss. Amyotrophic lateral sclerosis (ALS) is characterized by rapid, progressive motor neuron degeneration and muscle atrophy, causing paralysis and death. Patient tissue and animal models of ALS show destruction of upper and lower motor neuron cell bodies and loss of their associated axons. Here, we investigate whether loss of Sarm1 can mitigate motor neuron degeneration in the SOD1G93A mouse model of ALS. We found no change in survival, behavioral, electrophysiogical or histopathological outcomes in SOD1G93A mice null for Sarm1. Blocking Sarm1-mediated axon destruction alone is therefore not sufficient to suppress SOD1G93A-induced neurodegeneration. Our data suggest the molecular pathways driving axon loss in ALS may be Sarm1-independent or involve genetic pathways that act in a redundant fashion with Sarm1.
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Affiliation(s)
- Owen M Peters
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA.,Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Elizabeth A Lewis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jeannette M Osterloh
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Alexandra Weiss
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Johnny S Salameh
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Jake Metterville
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Robert H Brown
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Marc R Freeman
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
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Guvenc G, Kizmazoglu C, Aydin HE. Effect of Mannitol Infusion on Optic Nerve Injury After Acute Traumatic Subarachnoid Hemorrhage and Brain Injury. J Craniofac Surg 2018; 29:1772-1775. [PMID: 30106807 DOI: 10.1097/scs.0000000000004827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The primary aim of this paper is to investigate the neuroprotective and antiinflammatory effects of mannitol on optic nerve injury after acute traumatic subarachnoid hemorrhage and brain injury in rat models. Traumatic brain injury (TBI) and traumatic subarachnoid hemorrhage (tSAH) were produced by a custom-made weight-drop impact acceleration device. Thirty male Wistar rats were divided into 3 groups. Group I (n = 10) was the sham group, group II (n = 10) received TBI, and group III (n = 10) received TBI + mannitol (1 mg/kg intravenously). Optic nerve tissue glutathione peroxidase (GPx) and interleukin 1 beta (IL-1β) levels were measured 4 hours after the trauma. The authors used Kruskal-Wallis variance analysis and Mann-Whitney U tests for statistical analysis. Optic nerve tissue GPx levels were significantly higher in group III than in groups I and II (P < 0.05). Optic nerve tissue IL-1β levels were significantly lower in group III than in group II (P < 0.05) and higher than in group I (P < 0.05).Mannitol increased the antioxidant GPx levels and decreased the IL-1β levels, which can protect the optic nerve from secondary injury after severe acute trauma. Mannitol plays an important role in the treatment of acute severe indirect optic nerve injury after TBI and tSAH.
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Affiliation(s)
- Gonul Guvenc
- Department of Neurosurgery, Ataturk Training and Research Hospital, Katip Celebi University
| | - Ceren Kizmazoglu
- Department of Neurosurgery, School of Medicine Hospital, Dokuz Eylul University, Izmir
| | - Hasan Emre Aydin
- Department of Neurosurgery, Evliya Celebi Training and Research Hospital, Dumlupinar University, Kutahya, Turkey
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Heuss ND, Pierson MJ, Roehrich H, McPherson SW, Gram AL, Li L, Gregerson DS. Optic nerve as a source of activated retinal microglia post-injury. Acta Neuropathol Commun 2018; 6:66. [PMID: 30037353 PMCID: PMC6055350 DOI: 10.1186/s40478-018-0571-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 07/15/2018] [Indexed: 12/27/2022] Open
Abstract
Using mice expressing green fluorescent protein (GFP) from a transgenic CD11c promoter we found that a controlled optic nerve crush (ONC) injury attracted GFPhi retinal myeloid cells to the dying retinal ganglion cells and their axons. However, the origin of these retinal myeloid cells was uncertain. In this study we use transgenic mice in conjunction with ONC, partial and full optic nerve transection (ONT), and parabiosis to determine the origin of injury induced retinal myeloid cells. Analysis of parabiotic mice and fate mapping showed that responding retinal myeloid cells were not derived from circulating macrophages and that GFPhi myeloid cells could be derived from GFPlo microglia. Comparison of optic nerve to retina following an ONC showed a much greater concentration of GFPhi cells and GFPlo microglia in the optic nerve. Optic nerve injury also induced Ki67+ cells in the optic nerve but not in the retina. Comparison of the retinal myeloid cell response after full versus partial ONT revealed fewer GFPhi cells and GFPlo microglia in the retina following a full ONT despite it being a more severe injury, suggesting that full transection of the optic nerve can block the migration of responding myeloid cells to the retina. Our results suggest that the optic nerve can be a reservoir for activated microglia and other retinal myeloid cells in the retina following optic nerve injury.
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Divya MS, Rasheed VA, Schmidt T, Lalitha S, Hattar S, James J. Intraocular Injection of ES Cell-Derived Neural Progenitors Improve Visual Function in Retinal Ganglion Cell-Depleted Mouse Models. Front Cell Neurosci 2017; 11:295. [PMID: 28979193 PMCID: PMC5611488 DOI: 10.3389/fncel.2017.00295] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 09/05/2017] [Indexed: 12/16/2022] Open
Abstract
Retinal ganglion cell (RGC) transplantation is a promising strategy to restore visual function resulting from irreversible RGC degeneration occurring in glaucoma or inherited optic neuropathies. We previously demonstrated FGF2 induced differentiation of mouse embryonic stem cells (ESC) to RGC lineage, capable of retinal ganglion cell layer (GCL) integration upon transplantation. Here, we evaluated possible improvement of visual function by transplantation of ES cell derived neural progenitors in RGC depleted glaucoma mice models. ESC derived neural progenitors (ES-NP) were transplanted into N-Methyl-D-Aspartate (NMDA) injected, RGC-ablated mouse models and a pre-clinical glaucoma mouse model (DBA/2J) having sustained higher intra ocular pressure (IOP). Visual acuity and functional integration was evaluated by behavioral experiments and immunohistochemistry, respectively. GFP-expressing ES-NPs transplanted in NMDA-injected RGC-depleted mice differentiated into RGC lineage and possibly integrating into GCL. An improvement in visual acuity was observed after 2 months of transplantation, when compared to the pre-transplantation values. Expression of c-Fos in the transplanted cells, upon light induction, further suggests functional integration into the host retinal circuitry. However, the transplanted cells did not send axonal projections into optic nerve. Transplantation experiments in DBA/2J mouse showed no significant improvement in visual functions, possibly due to both host and transplanted retinal cell death which could be due to an inherent high IOP. We showed that, ES NPs transplanted into the retina of RGC-ablated mouse models could survive, differentiate to RGC lineage, and possibly integrate into GCL to improve visual function. However, for the survival of transplanted cells in glaucoma, strategies to control the IOP are warranted.
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Affiliation(s)
- Mundackal S Divya
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for BiotechnologyThiruvananthapuram, India
| | - Vazhanthodi A Rasheed
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for BiotechnologyThiruvananthapuram, India
| | - Tiffany Schmidt
- Department of Biology, Johns Hopkins UniversityBaltimore, MD, United States
| | - Soundararajan Lalitha
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for BiotechnologyThiruvananthapuram, India
| | - Samer Hattar
- Department of Biology, Johns Hopkins UniversityBaltimore, MD, United States
| | - Jackson James
- Neuro-Stem Cell Biology Laboratory, Neurobiology Division, Rajiv Gandhi Centre for BiotechnologyThiruvananthapuram, India
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Affiliation(s)
- Mohammadali Almasieh
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
| | - Leonard A. Levin
- Departments of Ophthalmology and Neurology, McGill University, Montreal H4A 3S5, Canada
- Maisonneuve-Rosemont Hospital Research Center and Department of Ophthalmology, University of Montreal, Montreal H1T 2M4, Canada
- Department of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin 53706
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JUN is important for ocular hypertension-induced retinal ganglion cell degeneration. Cell Death Dis 2017; 8:e2945. [PMID: 28726785 PMCID: PMC5550879 DOI: 10.1038/cddis.2017.338] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/06/2017] [Accepted: 06/12/2017] [Indexed: 12/14/2022]
Abstract
Ocular hypertension, a major risk factor for glaucoma, is thought to trigger glaucomatous neurodegeneration through injury to retinal ganglion cell (RGC) axons. The molecular signaling pathway leading from ocular hypertension to RGC degeneration, however, is not well defined. JNK signaling, a component of the mitogen-activated protein kinase (MAPK) family, and its canonical target, the transcription factor JUN, have been shown to regulate neurodegeneration in many different systems. JUN is expressed after glaucoma-relevant injuries and Jun deficiency protects RGCs after mechanical injury to the optic nerve. Here, we tested the importance of JNK–JUN signaling for RGC death after ocular hypertensive axonal injury in an age-related, mouse model of ocular hypertension. Immunohistochemistry was performed to evaluate JUN expression in ocular hypertensive DBA/2J mice. JUN was expressed in a temporal and spatial pattern consistent with a role in glaucomatous injury. To determine the importance of JUN in ocular hypertension-induced RGC death, a floxed allele of Jun and a retinal expressed cre recombinase (Six3-cre) were backcrossed onto the DBA/2J background. Intraocular pressure (IOP) and gross morphology of the retina and optic nerve head were assessed to determine whether removing Jun from the developing retina altered IOP elevation or retinal development. Jun deficiency in the retina did not alter DBA/2J IOP elevation or retinal development. Optic nerves and retinas were assessed at ages known to have glaucomatous damage in DBA/2J mice. Jun deficiency protected RGC somas from ocular hypertensive injury, but did not protect RGC axons from glaucomatous neurodegeneration. Jun is a major regulator of RGC somal degeneration after glaucomatous ocular hypertensive injury. These results suggest in glaucomatous neurodegeneration, JNK–JUN signaling has a major role as a pro-death signaling pathway between axonal injury and somal degeneration.
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Acute Axonal Degeneration Drives Development of Cognitive, Motor, and Visual Deficits after Blast-Mediated Traumatic Brain Injury in Mice. eNeuro 2016; 3:eN-NWR-0220-16. [PMID: 27822499 PMCID: PMC5086797 DOI: 10.1523/eneuro.0220-16.2016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/09/2016] [Accepted: 10/06/2016] [Indexed: 12/19/2022] Open
Abstract
Axonal degeneration is a prominent feature of many forms of neurodegeneration, and also an early event in blast-mediated traumatic brain injury (TBI), the signature injury of soldiers in Iraq and Afghanistan. It is not known, however, whether this axonal degeneration is what drives development of subsequent neurologic deficits after the injury. The Wallerian degeneration slow strain (WldS) of mice is resistant to some forms of axonal degeneration because of a triplicated fusion gene encoding the first 70 amino acids of Ufd2a, a ubiquitin-chain assembly factor, that is linked to the complete coding sequence of nicotinamide mononucleotide adenylyltransferase 1 (NMAT1). Here, we demonstrate that resistance of WldS mice to axonal degeneration after blast-mediated TBI is associated with preserved function in hippocampal-dependent spatial memory, cerebellar-dependent motor balance, and retinal and optic nerve–dependent visual function. Thus, early axonal degeneration is likely a critical driver of subsequent neurobehavioral complications of blast-mediated TBI. Future therapeutic strategies targeted specifically at mitigating axonal degeneration may provide a uniquely beneficial approach to treating patients suffering from the effects of blast-mediated TBI.
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Shao WY, Liu X, Gu XL, Ying X, Wu N, Xu HW, Wang Y. Promotion of axon regeneration and inhibition of astrocyte activation by alpha A-crystallin on crushed optic nerve. Int J Ophthalmol 2016; 9:955-66. [PMID: 27500100 DOI: 10.18240/ijo.2016.07.04] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 05/25/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the effects of αA-crystallin in astrocyte gliosis after optic nerve crush (ONC) and the mechanism of α-crystallin in neuroprotection and axon regeneration. METHODS ONC was established on the Sprague-Dawley rat model and αA-crystallin (10(-4) g/L, 4 µL) was intravitreously injected into the rat model. Flash-visual evoked potential (F-VEP) was examined 14d after ONC, and the glial fibrillary acidic protein (GFAP) levels in the retina and crush site were analyzed 1, 3, 5, 7 and 14d after ONC by immunohistochemistry (IHC) and Western blot respectively. The levels of beta Tubulin (TUJ1), growth-associated membrane phosphoprotein-43 (GAP-43), chondroitin sulfate proteoglycans (CSPGs) and neurocan were also determined by IHC 14d after ONC. RESULTS GFAP level in the retina and the optic nerve significantly increased 1d after ONC, and reached the peak level 7d post-ONC. Injection of αA-crystallin significantly decreased GFAP level in both the retina and the crush site 3d after ONC, and induced astrocytes architecture remodeling at the crush site. Quantification of retinal ganglion cell (RGC) axons indicated αA-crystallin markedly promoted axon regeneration in ONC rats and enhanced the regenerated axons penetrated into the glial scar. CSPGs and neurocan expression also decreased 14d after αA-crystallin injection. The amplitude (N1-P1) and latency (P1) of F-VEP were also restored. CONCLUSION Our results suggest α-crystallin promotes the axon regeneration of RGCs and suppresses the activation of astrocytes.
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Affiliation(s)
- Wei-Yang Shao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xiao Liu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xian-Liang Gu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Xi Ying
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Nan Wu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Hai-Wei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Yi Wang
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China; Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
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The role of autophagy in axonal degeneration of the optic nerve. Exp Eye Res 2016; 144:81-9. [DOI: 10.1016/j.exer.2015.08.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/06/2015] [Accepted: 08/18/2015] [Indexed: 11/21/2022]
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Ribas VT, Koch JC, Michel U, Bähr M, Lingor P. Attenuation of Axonal Degeneration by Calcium Channel Inhibitors Improves Retinal Ganglion Cell Survival and Regeneration After Optic Nerve Crush. Mol Neurobiol 2016; 54:72-86. [PMID: 26732591 DOI: 10.1007/s12035-015-9676-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/21/2015] [Indexed: 01/08/2023]
Abstract
Axonal degeneration is one of the initial steps in many traumatic and neurodegenerative central nervous system (CNS) disorders and thus a promising therapeutic target. A focal axonal lesion is followed by acute axonal degeneration (AAD) of both adjacent axon parts, before proximal and distal parts follow different degenerative fates at later time points. Blocking calcium influx by calcium channel inhibitors was previously shown to attenuate AAD after optic nerve crush (ONC). However, it remains unclear whether the attenuation of AAD also promotes consecutive axonal regeneration. Here, we used a rat ONC model to study the effects of calcium channel inhibitors on axonal degeneration, retinal ganglion cell (RGC) survival, and axonal regeneration, as well as the molecular mechanisms involved. Application of calcium channel inhibitors attenuated AAD after ONC and preserved axonal integrity as visualized by live imaging of optic nerve axons. Consecutively, this resulted in improved survival of RGCs and improved axonal regeneration at 28 days after ONC. We show further that calcium channel inhibition attenuated lesion-induced calpain activation in the proximity of the crush and inhibited the activation of the c-Jun N-terminal kinase pathway. Pro-survival signaling via Akt in the retina was also increased. Our data thus show that attenuation of AAD improves consecutive neuronal survival and axonal regeneration and that calcium channel inhibitors could be valuable tools for therapeutic interventions in traumatic and degenerative CNS disorders.
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Affiliation(s)
- Vinicius T Ribas
- Department of Neurology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Jan C Koch
- Department of Neurology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Uwe Michel
- Department of Neurology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany
| | - Mathias Bähr
- Department of Neurology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Paul Lingor
- Department of Neurology, University Medicine Göttingen, Robert-Koch-Str. 40, 37075, Göttingen, Germany. .,Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.
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Li HY, Ruan YW, Kau PWF, Chiu K, Chang RCC, Chan HHL, So KF. Effect of Lycium barbarum (Wolfberry) on alleviating axonal degeneration after partial optic nerve transection. Cell Transplant 2015; 24:403-17. [PMID: 25622224 DOI: 10.3727/096368915x686896] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Our previous results showed that the polysaccharides extracted from Lycium barbarum (LBP) could delay secondary degeneration of retinal ganglion cell bodies and improve the function of the retinas after partial optic nerve transection (PONT). Although the common degeneration mechanisms were believed to be shared by both neuronal bodies and axons, recently published data from slow Wallerian degeneration mutant (Wld(s)) mice supported the divergence in the mechanisms of them. Therefore, we want to determine if LBP could also delay the degeneration of axons after PONT. Microglia/macrophages were thought to be a source of reactive oxygen species after central nervous system (CNS) injury. After PONT, however, oxidative stress was believed to occur prior to the activation of microglia/macrophages in the areas vulnerable to secondary degeneration both in the optic nerves (ONs) and the retinas. But the results did not take into account the morphological changes of microglia/macrophages after their activation. So we examined the morphology in addition to the response magnitude of microglia/macrophages to determine their time point of activation. In addition, the effects of LBP on the activation of microglia/macrophages were investigated. The results showed that (1) LBP reduced the loss of axons in the central ONs and preserved the g-ratio (axon diameter/fiber diameter) in the ventral ONs although no significant effect was detected in the dorsal ONs; (2) microglia/macrophages were activated in the ONs by 12 h after PONT; (3) LBP decreased the response magnitude of microglia/macrophages 4 weeks after PONT. In conclusion, our results showed that LBP could delay secondary degeneration of the axons, and LBP could also inhibit the activation of microglia/macrophages. Therefore, LBP could be a promising herbal medicine to delay secondary degeneration in the CNS via modulating the function of microglia/macrophages.
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Affiliation(s)
- Hong-Ying Li
- GHM Institute of CNS Regeneration and Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, China
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Comparative evaluation of methods for estimating retinal ganglion cell loss in retinal sections and wholemounts. PLoS One 2014; 9:e110612. [PMID: 25343338 PMCID: PMC4208790 DOI: 10.1371/journal.pone.0110612] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 09/20/2014] [Indexed: 11/19/2022] Open
Abstract
To investigate the reliability of different methods of quantifying retinal ganglion cells (RGCs) in rat retinal sections and wholemounts from eyes with either intact optic nerves or those axotomised after optic nerve crush (ONC). Adult rats received a unilateral ONC and after 21 days the numbers of Brn3a+, βIII-tubulin+ and Islet-1+ RGCs were quantified in either retinal radial sections or wholemounts in which FluoroGold (FG) was injected 48 h before harvesting. Phenotypic antibody markers were used to distinguish RGCs from astrocytes, macrophages/microglia and amacrine cells. In wholemounted retinae, counts of FG+ and Brn3a+ RGCs were of similar magnitude in eyes with intact optic nerves and were similarly reduced after ONC. Larger differences in RGC number were detected between intact and ONC groups when images were taken closer to the optic nerve head. In radial sections, Brn3a did not stain astrocytes, macrophages/microglia or amacrine cells, whereas βIII-tubulin and Islet-1 did localize to amacrine cells as well as RGCs. The numbers of βIII-tubulin+ RGCs was greater than Brn3a+ RGCs, both in retinae from eyes with intact optic nerves and eyes 21 days after ONC. Islet-1 staining also overestimated the number of RGCs compared to Brn3a, but only after ONC. Estimates of RGC loss were similar in Brn3a-stained radial retinal sections compared to both Brn3a-stained wholemounts and retinal wholemounts in which RGCs were backfilled with FG, with sections having the added advantage of reducing experimental animal usage.
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Mead B, Logan A, Berry M, Leadbeater W, Scheven BA. Paracrine-mediated neuroprotection and neuritogenesis of axotomised retinal ganglion cells by human dental pulp stem cells: comparison with human bone marrow and adipose-derived mesenchymal stem cells. PLoS One 2014; 9:e109305. [PMID: 25290916 PMCID: PMC4188599 DOI: 10.1371/journal.pone.0109305] [Citation(s) in RCA: 179] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/10/2014] [Indexed: 12/16/2022] Open
Abstract
We have investigated and compared the neurotrophic activity of human dental pulp stem cells (hDPSC), human bone marrow-derived mesenchymal stem cells (hBMSC) and human adipose-derived stem cells (hAMSC) on axotomised adult rat retinal ganglion cells (RGC) in vitro in order to evaluate their therapeutic potential for neurodegenerative conditions of RGC. Using the transwell system, RGC survival and length/number of neurites were quantified in coculture with stem cells in the presence or absence of specific Fc-receptor inhibitors to determine the role of NGF, BDNF, NT-3, VEGF, GDNF, PDGF-AA and PDGF-AB/BB in stem cell-mediated RGC neuroprotection and neuritogenesis. Conditioned media, collected from cultured hDPSC/hBMSC/hAMSC, were assayed for the secreted growth factors detailed above using ELISA. PCR array determined the hDPSC, hBMSC and hAMSC expression of genes encoding 84 growth factors and receptors. The results demonstrated that hDPSC promoted significantly more neuroprotection and neuritogenesis of axotomised RGC than either hBMSC or hAMSC, an effect that was neutralized after the addition of specific Fc-receptor inhibitors. hDPSC secreted greater levels of various growth factors including NGF, BDNF and VEGF compared with hBMSC/hAMSC. The PCR array confirmed these findings and identified VGF as a novel potentially therapeutic hDPSC-derived neurotrophic factor (NTF) with significant RGC neuroprotective properties after coculture with axotomised RGC. In conclusion, hDPSC promoted significant multi-factorial paracrine-mediated RGC survival and neurite outgrowth and may be considered a potent and advantageous cell therapy for retinal nerve repair.
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Affiliation(s)
- Ben Mead
- Neurotrauma Research Group, Neurobiology Section, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
- School of Dentistry, University of Birmingham, Birmingham, United Kingdom
- * E-mail:
| | - Ann Logan
- Neurotrauma Research Group, Neurobiology Section, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Martin Berry
- Neurotrauma Research Group, Neurobiology Section, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Wendy Leadbeater
- Neurotrauma Research Group, Neurobiology Section, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham, United Kingdom
| | - Ben A. Scheven
- School of Dentistry, University of Birmingham, Birmingham, United Kingdom
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Fernandes KA, Harder JM, John SW, Shrager P, Libby RT. DLK-dependent signaling is important for somal but not axonal degeneration of retinal ganglion cells following axonal injury. Neurobiol Dis 2014; 69:108-16. [PMID: 24878510 DOI: 10.1016/j.nbd.2014.05.015] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 04/18/2014] [Accepted: 05/17/2014] [Indexed: 11/16/2022] Open
Abstract
Injury to retinal ganglion cell (RGC) axons triggers rapid activation of Jun N-terminal kinase (JNK) signaling, a major prodeath pathway in injured RGCs. Of the multiple kinases that can activate JNK, dual leucine kinase (Dlk) is known to regulate both apoptosis and Wallerian degeneration triggered by axonal insult. Here we tested the importance of Dlk in regulating somal and axonal degeneration of RGCs following axonal injury. Removal of DLK from the developing optic cup did not grossly affect developmental RGC death or inner plexiform layer organization. In the adult, Dlk deficiency significantly delayed axonal-injury induced RGC death. The activation of JUN was also attenuated in Dlk deficient retinas. Dlk deficiency attenuated the activation of the somal pool of JNK but did not prevent activation of the axonal pool of JNK after axonal injury, indicating that JNK activation in different cellular compartments of an RGC following axonal injury is regulated by distinct upstream kinases. In contrast to its robust influence on somal degeneration, Dlk deficiency did not alter RGC axonal degeneration after axonal injury as assessed using physiological readouts of optic nerve function.
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Affiliation(s)
- Kimberly A Fernandes
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Jeffrey M Harder
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Simon W John
- The Jackson Laboratory and Howard Hughes Medical Institute, Bar Harbor, ME 04609, USA
| | - Peter Shrager
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Richard T Libby
- Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY 14642, USA; Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA; The Center for Visual Sciences, University of Rochester Medical Center, Rochester, NY 14642, USA.
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16
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Wallerian degeneration: an emerging axon death pathway linking injury and disease. Nat Rev Neurosci 2014; 15:394-409. [DOI: 10.1038/nrn3680] [Citation(s) in RCA: 387] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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17
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Massoll C, Mando W, Chintala SK. Excitotoxicity upregulates SARM1 protein expression and promotes Wallerian-like degeneration of retinal ganglion cells and their axons. Invest Ophthalmol Vis Sci 2013; 54:2771-80. [PMID: 23518770 PMCID: PMC3632266 DOI: 10.1167/iovs.12-10973] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Accepted: 03/14/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study investigated the role of sterile alpha/Armadillo/Toll-Interleukin receptor homology domain 1 protein (SARM1) in Wallerian-like degeneration of retinal ganglion cells (RGCs) and their axons after inducing excitotoxicity. METHODS To induce excitotoxicity, kainic acid (KA) was injected into the vitreous humor of B6.Cg-Tg(Thy1-YFP)HJrs/J mice. Control mice received PBS. At 24, 48, and 72 hours after injection, degeneration of RGCs and their axons in the retina was determined by fundus imaging, and axonal degeneration in the optic nerves was determined by fluorescence microscopy. SARM1 protein levels were determined by Western blot analysis and SARM1 tissue localization was determined by immunohistochemistry. Causal role of SARM1 in KA-mediated degeneration of RGCs and their axons was determined by treating the eyes with KA along with Sarm1 silencer siRNA. RESULTS Fundus imaging and microscopic analysis indicated that KA promoted Wallerian-like degeneration of RGCs and axons in KA-treated eyes, but not in PBS-treated eyes. Quantitative analysis indicated a significant increase in degeneration of RGCs and their axons in KA-treated injected eyes, but not in PBS-treated eyes. Compared with low levels of SARM1 protein in retinal protein extracts, retinal cross sections, and optic nerve from PBS-treated eyes, SARM1 protein levels were increased in KA-treated eyes. Finally, treatment of eyes with KA along with a Sarm1 silencer siRNA attenuated KA-mediated degeneration of RGCs and their axons significantly. CONCLUSIONS Results presented in this study, for the first time, show that KA-mediated upregulation of SARM1 protein promotes Wallerian-like degeneration of RGCs and their axons.
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Affiliation(s)
- Charlotte Massoll
- Eye Research Institute of Oakland University, Rochester, Michigan 48309, USA
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