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Buonfiglio F, Böhm EW, Pfeiffer N, Gericke A. Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases? Antioxidants (Basel) 2023; 12:1465. [PMID: 37508003 PMCID: PMC10376185 DOI: 10.3390/antiox12071465] [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: 06/27/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Optic nerve disorders encompass a wide spectrum of conditions characterized by the loss of retinal ganglion cells (RGCs) and subsequent degeneration of the optic nerve. The etiology of these disorders can vary significantly, but emerging research highlights the crucial role of oxidative stress, an imbalance in the redox status characterized by an excess of reactive oxygen species (ROS), in driving cell death through apoptosis, autophagy, and inflammation. This review provides an overview of ROS-related processes underlying four extensively studied optic nerve diseases: glaucoma, Leber's hereditary optic neuropathy (LHON), anterior ischemic optic neuropathy (AION), and optic neuritis (ON). Furthermore, we present preclinical findings on antioxidants, with the objective of evaluating the potential therapeutic benefits of targeting oxidative stress in the treatment of optic neuropathies.
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Affiliation(s)
- Francesco Buonfiglio
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (E.W.B.); (N.P.)
| | | | | | - Adrian Gericke
- Department of Ophthalmology, University Medical Center, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; (E.W.B.); (N.P.)
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2
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Ye J, Zhu H, Yan W, Tu Y, Hu X, Wu W. Retinal peripapillary microvasculature in indirect traumatic optic neuropathy predicted prognosis of endoscopic trans-ethmosphenoid optic canal decompression. Acta Ophthalmol 2023; 101:e226-e235. [PMID: 36053015 DOI: 10.1111/aos.15243] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/29/2022] [Accepted: 08/19/2022] [Indexed: 11/27/2022]
Abstract
PURPOSES The purpose of this study is to quantify the alteration of retinal peripapillary microvasculature and structure in unilateral indirect traumatic optic neuropathy (ITON) and figure out predicted factors of visual improvement for ITON patients with endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) after one month. METHODS Twenty healthy controls and 72 unilateral ITON patients were included. Optical coherence tomography angiography was used to analyse radial peripapillary capillary (RPC) density, peripapillary retinal nerve fibre layer (pRNFL) thickness, superficial retinal capillary plexus (SRCP) and deep retinal capillary plexus (DRCP) density. Associations between preoperative parameters and postoperative best-corrected visual acuity (BCVA) were determined. The receiver operating characteristic (ROC) curves were used to figure out predicted factors of visual improvement for ITON after ETOCD one month. RESULTS In ITON eyes, the preoperative global RPC density, pRNFL thickness and SRCP density were reduced compared with unaffected eyes (p ≤ 0.001). Multivariate linear regression showed that preoperative global RPC density (Standardized β = -0.273), SRCP density (Standardized β = -0.183), DRCP density (Standardized β = -0.098) and preoperative BCVA (Standardized β = 0.795) were associated with the postoperative BCVA (All p < 0.001). The area under the curve (AUC) of preoperative global RPC density to predict visual improvement after ETOCD was 0.816, while the AUCs of preoperative BCVA, global pRNFL thickness, SRCP and DRCP density were 0.575, 0.756, 0.516 and 0.615, respectively. CONCLUSIONS The alteration of peripapillary area, especially the reduced RPC density, occurred in ITON eyes. The preoperative RPC density was associated with postoperative BCVA and was shown to be highly predictive for visual improvement after ETOCD one month.
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Affiliation(s)
- Jie Ye
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Hui Zhu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Wentao Yan
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yunhai Tu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiaozhou Hu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Wencan Wu
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
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Secondary Degeneration of Oligodendrocyte Precursor Cells Occurs as Early as 24 h after Optic Nerve Injury in Rats. Int J Mol Sci 2023; 24:ijms24043463. [PMID: 36834873 PMCID: PMC9964292 DOI: 10.3390/ijms24043463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Optic nerve injury causes secondary degeneration, a sequela that spreads damage from the primary injury to adjacent tissue, through mechanisms such as oxidative stress, apoptosis, and blood-brain barrier (BBB) dysfunction. Oligodendrocyte precursor cells (OPCs), a key component of the BBB and oligodendrogenesis, are vulnerable to oxidative deoxyribonucleic acid (DNA) damage by 3 days post-injury. However, it is unclear whether oxidative damage in OPCs occurs earlier at 1 day post-injury, or whether a critical 'window-of-opportunity' exists for therapeutic intervention. Here, a partial optic nerve transection rat model of secondary degeneration was used with immunohistochemistry to assess BBB dysfunction, oxidative stress, and proliferation in OPCs vulnerable to secondary degeneration. At 1 day post-injury, BBB breach and oxidative DNA damage were observed, alongside increased density of DNA-damaged proliferating cells. DNA-damaged cells underwent apoptosis (cleaved caspase3+), and apoptosis was associated with BBB breach. OPCs experienced DNA damage and apoptosis and were the major proliferating cell type with DNA damage. However, the majority of caspase3+ cells were not OPCs. These results provide novel insights into acute secondary degeneration mechanisms in the optic nerve, highlighting the need to consider early oxidative damage to OPCs in therapeutic efforts to limit degeneration following optic nerve injury.
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4
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Maxwell CJ, Soltisz AM, Rich WW, Choi A, Reilly MA, Swindle-Reilly KE. Tunable alginate hydrogels as injectable drug delivery vehicles for optic neuropathy. J Biomed Mater Res A 2022; 110:1621-1635. [PMID: 35607724 PMCID: PMC9543600 DOI: 10.1002/jbm.a.37412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/08/2022] [Accepted: 05/06/2022] [Indexed: 11/08/2022]
Abstract
Many disease pathologies, particularly in the eye, are induced by oxidative stress. In particular, injury to the optic nerve (ON), or optic neuropathy, is one of the most common causes of vision loss. Traumatic optic neuropathy (TON) occurs when the ON is damaged following blunt or penetrating trauma to either the head or eye. Currently, there is no effective treatment for TON, only management options, namely the systematic delivery of corticosteroids and surgical decompression of the optic nerve. Unfortunately, neither option alleviates the generation of reactive oxygen species (ROS) which are responsible for downstream damage to the ON. Additionally, the systemic delivery of corticosteroids can cause fatal off‐target effects in cases with brain involvement. In this study, we developed a tunable injectable hydrogel delivery system for local methylene blue (MB) delivery using an internal method of crosslinking. MB was chosen due to its ROS scavenging ability and neuroprotective properties. Our MB‐loaded polymeric scaffold demonstrated prolonged release of MB as well as in situ gel formation. Additionally, following rheological characterization, these alginate hydrogels demonstrated minimal cytotoxicity to human retinal pigment epithelial cells in vitro and exhibited injection feasibility through small‐gauge needles. Our chosen MB concentrations displayed a high degree of ROS scavenging following release from the alginate hydrogels, suggesting this approach may be successful in reducing ROS levels following ON injury, or could be applied to other ocular injuries.
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Affiliation(s)
- Courtney J Maxwell
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Andrew M Soltisz
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Wade W Rich
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Andrew Choi
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Matthew A Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Katelyn E Swindle-Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, USA.,William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, Ohio, USA
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5
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Cáceres-Vélez PR, Hui F, Hercus J, Bui B, Jusuf PR. Restoring the oxidative balance in age-related diseases - An approach in glaucoma. Ageing Res Rev 2022; 75:101572. [PMID: 35065274 DOI: 10.1016/j.arr.2022.101572] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 12/10/2021] [Accepted: 01/18/2022] [Indexed: 02/07/2023]
Abstract
As human life expectancy increases, age-related health issues including neurodegenerative diseases continue to rise. Regardless of genetic or environmental factors, many neurodegenerative conditions share common pathological mechanisms, such as oxidative stress, a hallmark of many age-related health burdens. In this review, we describe oxidative damage and mitochondrial dysfunction in glaucoma, an age-related neurodegenerative eye disease affecting 80 million people worldwide. We consider therapeutic approaches used to counteract oxidative stress in glaucoma, including untapped treatment options such as novel plant-derived antioxidant compounds that can reduce oxidative stress and prevent neuronal loss. We summarize the current pre-clinical models and clinical work exploring the therapeutic potential of a range of candidate plant-derived antioxidant compounds. Finally, we explore advances in drug delivery systems, particular those employing nanotechnology-based carriers which hold significant promise as a carrier for antioxidants to treat age-related disease, thus reviewing the key current state of all of the aspects required towards translation.
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6
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Kang EYC, Liu PK, Wen YT, Quinn PMJ, Levi SR, Wang NK, Tsai RK. Role of Oxidative Stress in Ocular Diseases Associated with Retinal Ganglion Cells Degeneration. Antioxidants (Basel) 2021; 10:1948. [PMID: 34943051 PMCID: PMC8750806 DOI: 10.3390/antiox10121948] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/25/2021] [Accepted: 12/02/2021] [Indexed: 12/12/2022] Open
Abstract
Ocular diseases associated with retinal ganglion cell (RGC) degeneration is the most common neurodegenerative disorder that causes irreversible blindness worldwide. It is characterized by visual field defects and progressive optic nerve atrophy. The underlying pathophysiology and mechanisms of RGC degeneration in several ocular diseases remain largely unknown. RGCs are a population of central nervous system neurons, with their soma located in the retina and long axons that extend through the optic nerve to form distal terminals and connections in the brain. Because of this unique cytoarchitecture and highly compartmentalized energy demand, RGCs are highly mitochondrial-dependent for adenosine triphosphate (ATP) production. Recently, oxidative stress and mitochondrial dysfunction have been found to be the principal mechanisms in RGC degeneration as well as in other neurodegenerative disorders. Here, we review the role of oxidative stress in several ocular diseases associated with RGC degenerations, including glaucoma, hereditary optic atrophy, inflammatory optic neuritis, ischemic optic neuropathy, traumatic optic neuropathy, and drug toxicity. We also review experimental approaches using cell and animal models for research on the underlying mechanisms of RGC degeneration. Lastly, we discuss the application of antioxidants as a potential future therapy for the ocular diseases associated with RGC degenerations.
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Affiliation(s)
- Eugene Yu-Chuan Kang
- Department of Ophthalmology, Linkou Chang Gung Memorial Hospital, Taoyuan 33302, Taiwan;
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Pei-Kang Liu
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung 80424, Taiwan;
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80424, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Yao-Tseng Wen
- Institute of Eye Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97403, Taiwan;
| | - Peter M. J. Quinn
- Jonas Children’s Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; (P.M.J.Q.); (S.R.L.)
| | - Sarah R. Levi
- Jonas Children’s Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA; (P.M.J.Q.); (S.R.L.)
| | - Nan-Kai Wang
- Edward S. Harkness Eye Institute, Department of Ophthalmology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rong-Kung Tsai
- Institute of Eye Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97403, Taiwan;
- Institute of Medical Sciences, Tzu Chi University, Hualien 97403, Taiwan
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7
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Anyaegbu CC, Mao Y, McGonigle T, Raja S, Clarke T, Black AMB, Solomon T, Fuller K, Fitzgerald M. Simultaneous flow cytometric characterization of multiple cell types and metabolic states in the rat brain after repeated mild traumatic brain injury. J Neurosci Methods 2021; 359:109223. [PMID: 34004202 DOI: 10.1016/j.jneumeth.2021.109223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 12/18/2022]
Abstract
BACKGROUND Cellular responses at the sub-acute phase of mild traumatic brain injury (mTBI), and their contribution to ongoing damage, are unclear, complex and require simultaneous assessment of multiple cells to elucidate. NEW METHOD An 11-colour flow cytometry method for analysing brain cells was evaluated in a weight-drop rat model of repeated mTBI. Animals received sham, one, two or three mTBI delivered at 24 h intervals (n = 6/group). Cerebrum homogenates were prepared 11 days after first mTBI, in two cohorts of n = 3/group to enable same-day staining of fresh tissue. Percentages of neurons, astrocytes, microglia, mature oligodendrocytes and NeuN + CC1+ cells, neutrophils, macrophages and non-myeloid leukocytes, and their immunoreactivity for cell damage indicators (inducible nitric oxide synthase; iNOS, proliferating cell nuclear antigen; PCNA, 8-Oxo-2'-deoxyguanosine; 8OHDG and 4-hydroxynonenal; HNE), were assessed. RESULTS Median fluorescence intensity (MFI) of iNOS in activated microglia increased following two, but not one or three, mTBI (p = 0.04). However, there were differences between processing cohorts in terms of percentages and MFI of some PCNA+, iNOS+, 8OHDG + and HNE + cell populations. COMPARISON WITH EXISTING METHODS Previous applications of flow cytometry for rat brain analysis were typically limited to three or four markers. This method uses 11 markers to identify nine cell populations and evaluate their immunoreactivity to four metabolic indicators of cell damage. CONCLUSIONS Flow cytometry can be useful for discerning injury-related changes in multiple rat brain cells. However, markers sensitive to subtle changes in experimental conditions must be identified in pilot experiments and subsequently analysed in the same tissue-processing cohort.
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Affiliation(s)
- Chidozie C Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia.
| | - Yilin Mao
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Terry McGonigle
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Sushmitha Raja
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Thomas Clarke
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Anna M B Black
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Tanya Solomon
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia
| | - Kathy Fuller
- Division of Cancer Biology, School of Biomedical Sciences, The University of Western Australia, 35 Stirling Hwy, Nedlands 6009 Western Australia, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Belmont, Western Australia, Australia; Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands 6009 Western Australia, Australia
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8
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DeJulius C, Bernardo-Colón A, Naguib S, Backstrom J, Kavanaugh T, Gupta M, Duvall C, Rex T. Microsphere antioxidant and sustained erythropoietin-R76E release functions cooperate to reduce traumatic optic neuropathy. J Control Release 2021; 329:762-773. [PMID: 33049330 PMCID: PMC8162757 DOI: 10.1016/j.jconrel.2020.10.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 09/30/2020] [Accepted: 10/05/2020] [Indexed: 01/12/2023]
Abstract
Wild-type erythropoietin (EPO) is promising for neuroprotection, but its therapeutic use is limited because it causes a systemic rise in hematocrit. We have developed an EPO-R76E derivative that maintains neuroprotective function without effects on hematocrit, but this protein has a short half-life in vivo. Here, we compare the efficacy and carrier-induced inflammatory response of two polymeric microparticle (MP) EPO-R76E sustained release formulations based on conventional hydrolytically degradable poly(lactic-co-glycolic acid) (PLGA) and reactive oxygen species (ROS)-degradable poly(propylene sulfide) (PPS). Both MP types effectively loaded EPO-R76E and achieved sustained release, providing detectable levels of EPO-R76E at the injection site in the eye in vivo for at least 28 days. Testing in an in vitro oxidative stress assay and a mouse model of blast-induced indirect traumatic optic neuropathy (bITON) showed that PPS and PLGA MP-mediated delivery of EPO-R76E provided therapeutic protection. While unloaded PLGA MPs inherently increase levels of pro-inflammatory cytokines in the bITON model, drug-free PPS MPs have innate antioxidant properties that provide therapeutic benefit both in vitro and in vivo. Both PLGA and PPS MPs enabled sustained release of EPO-R76E, providing therapeutic benefits including reduction in inflammation and axon degeneration, and preservation of visual function as measured by electroretinogram. The PPS-based MP platform is especially promising for further development, as the delivery system provides inherent antioxidant benefits that can be harnessed to work in complement with EPO-R76E or other drugs for neuroprotection in the setting of traumatic eye injury.
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Affiliation(s)
- C.R. DeJulius
- Department of Biomedical Engineering, Vanderbilt University, United States
| | - A. Bernardo-Colón
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, United States
| | - S. Naguib
- Department of Ophthalmology & Visual Science, Vanderbilt University School of Medicine, United States
| | - J.R. Backstrom
- Department of Biomedical Engineering, Vanderbilt University, United States,Vanderbilt Eye Institute, Vanderbilt University Medical Center, United States
| | - T. Kavanaugh
- Department of Biomedical Engineering, Vanderbilt University, United States
| | - M.K. Gupta
- Department of Biomedical Engineering, Vanderbilt University, United States
| | - C.L. Duvall
- Department of Biomedical Engineering, Vanderbilt University, United States,Corresponding authors at: Department of Biomedical Engineering, Vanderbilt University, and Vanderbilt Eye Institute, Vanderbilt University Medical Center, United States. (C.L. Duvall), (T.S. Rex)
| | - T.S. Rex
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, United States,Department of Ophthalmology & Visual Science, Vanderbilt University School of Medicine, United States,Corresponding authors at: Department of Biomedical Engineering, Vanderbilt University, and Vanderbilt Eye Institute, Vanderbilt University Medical Center, United States. (C.L. Duvall), (T.S. Rex)
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O'Hare Doig RL, Santhakumar S, Fehily B, Raja S, Solomon T, Bartlett CA, Fitzgerald M, Hodgetts SI. Acute Cellular and Functional Changes With a Combinatorial Treatment of Ion Channel Inhibitors Following Spinal Cord Injury. Front Mol Neurosci 2020; 13:85. [PMID: 32670018 PMCID: PMC7331598 DOI: 10.3389/fnmol.2020.00085] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 04/24/2020] [Indexed: 01/12/2023] Open
Abstract
Reducing the extent of secondary degeneration following spinal cord injury (SCI) is necessary to preserve function, but treatment options have thus far been limited. A combination of the ion channel inhibitors Lomerizine (Lom), YM872 and oxATP, to inhibit voltage-gated Ca2+ channels, Ca2+ permeable AMPA receptors, and purinergic P2X7 receptors respectively, effectively limits secondary consequences of injury in in vitro and in vivo models of CNS injury. Here, we investigated the efficacy of these inhibitors in a clinically relevant model of SCI. Fischer (F344) rats were subjected to a moderate (150 kD) contusive SCI at thoracic level T10 and assessed at 2 weeks or 10 weeks post-injury. Lom was delivered orally twice daily and YM872 and oxATP were delivered via osmotic mini-pump implanted at the time of SCI until 2 weeks following injury. Open field locomotion analysis revealed that treatment with the three inhibitors in combination improved the rate of functional recovery of the hind limb (compared to controls) as early as 1-day post-injury, with beneficial effects persisting to 14 days post-injury, while all three inhibitors were present. At 2 weeks following combinatorial treatment, the functional improvement was associated with significantly decreased cyst size, increased immunoreactivity of β-III tubulin+ve axons, myelin basic protein, and reduced lipid peroxidation by-products, and increased CC1+ve oligodendrocytes and NG2+ve/PDGFα+ve oligodendrocyte progenitor cell densities, compared to vehicle-treated SCI animals. The combination of Lom, oxATP, and YM872 shows preclinical promise for control of secondary degeneration following SCI, and further investigation of long-term sustained treatment is warranted.
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Affiliation(s)
- Ryan L O'Hare Doig
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Neil Sachse Centre for Spinal Cord Research, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.,Adelaide Spinal Research Group, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Sreya Santhakumar
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
| | - Brooke Fehily
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Sushmitha Raja
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Tanya Solomon
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia.,Curtin Health Innovation Research Institute, Curtin University, Nedlands, WA, Australia
| | - Stuart I Hodgetts
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, Australia.,Perron Institute for Neurological and Translational Science, Nedlands, WA, Australia
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10
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Warnock A, Toomey LM, Wright AJ, Fisher K, Won Y, Anyaegbu C, Fitzgerald M. Damage Mechanisms to Oligodendrocytes and White Matter in Central Nervous System Injury: The Australian Context. J Neurotrauma 2020; 37:739-769. [DOI: 10.1089/neu.2019.6890] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Andrew Warnock
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Lillian M. Toomey
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
| | - Alexander J. Wright
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Katherine Fisher
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Yerim Won
- School of Human Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Chidozie Anyaegbu
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
| | - Melinda Fitzgerald
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Nedlands, Western Australia, Australia
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11
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Guo L, Davis BM, Ravindran N, Galvao J, Kapoor N, Haamedi N, Shamsher E, Luong V, Fico E, Cordeiro MF. Topical recombinant human Nerve growth factor (rh-NGF) is neuroprotective to retinal ganglion cells by targeting secondary degeneration. Sci Rep 2020; 10:3375. [PMID: 32099056 PMCID: PMC7042238 DOI: 10.1038/s41598-020-60427-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Optic neuropathy is a major cause of irreversible blindness worldwide, and no effective treatment is currently available. Secondary degeneration is believed to be the major contributor to retinal ganglion cell (RGC) death, the endpoint of optic neuropathy. Partial optic nerve transection (pONT) is an established model of optic neuropathy. Although the mechanisms of primary and secondary degeneration have been delineated in this model, until now how this is influenced by therapy is not well-understood. In this article, we describe a clinically translatable topical, neuroprotective treatment (recombinant human nerve growth factor, rh-NGF) predominantly targeting secondary degeneration in a pONT rat model. Topical application of rh-NGF twice daily for 3 weeks significantly improves RGC survival as shown by reduced RGC apoptosis in vivo and increased RGC population in the inferior retina, which is predominantly affected in this model by secondary degeneration. Topical rh-NGF also promotes greater axonal survival and inhibits astrocyte activity in the optic nerve. Collectively, these results suggest that topical rh-NGF exhibits neuroprotective effects on retinal neurons via influencing secondary degeneration process. As topical rh-NGF is already involved in early clinical trials, this highlights its potential in multiple indications in patients, including those affected by glaucomatous optic neuropathy.
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Affiliation(s)
- Li Guo
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Benjamin M Davis
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nivedita Ravindran
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Joana Galvao
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Neel Kapoor
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nasrin Haamedi
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ehtesham Shamsher
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Vy Luong
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Elena Fico
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom.,Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - M Francesca Cordeiro
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom. .,Western Eye Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
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Toomey LM, Bartlett CA, Gavriel N, McGonigle T, Majimbi M, Gopalasingam G, Rodger J, Fitzgerald M. Comparing modes of delivery of a combination of ion channel inhibitors for limiting secondary degeneration following partial optic nerve transection. Sci Rep 2019; 9:15297. [PMID: 31653948 PMCID: PMC6814709 DOI: 10.1038/s41598-019-51886-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 10/07/2019] [Indexed: 11/28/2022] Open
Abstract
Injury to the central nervous system is exacerbated by secondary degeneration. Previous research has shown that a combination of orally and locally administered ion channel inhibitors following partial optic nerve injury protects the myelin sheath and preserves function in the ventral optic nerve, vulnerable to secondary degeneration. However, local administration is often not clinically appropriate. This study aimed to compare the efficacy of systemic and local delivery of the ion channel inhibitor combination of lomerizine, brilliant blue G (BBG) and YM872, which inhibits voltage-gated calcium channels, P2X7 receptors and Ca2+ permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors respectively. Following a partial optic nerve transection, adult female PVG rats were treated with BBG and YM872 delivered via osmotic mini pump directly to the injury site, or via intraperitoneal injection, both alongside oral administration of lomerizine. Myelin structure was preserved with both delivery modes of the ion channel inhibitor combination. However, there was no effect of treatment on inflammation, either peripherally or at the injury site, or on the density of oligodendroglial cells. Taken together, the data indicate that even at lower concentrations, the combinatorial treatment may be preserving myelin structure, and that systemic and local delivery are comparable at improving outcomes following neurotrauma.
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Affiliation(s)
- Lillian M Toomey
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia
- Curtin Health Innovation Research Institute, Curtin University, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia
| | - Nikolas Gavriel
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia
| | - Terence McGonigle
- Curtin Health Innovation Research Institute, Curtin University, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia
| | - Maimuna Majimbi
- Curtin Health Innovation Research Institute, Curtin University, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia
| | - Gopana Gopalasingam
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia
| | - Jennifer Rodger
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia
- Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, 35 Stirling Hwy, Perth, 6009, Western Australia, Australia.
- Curtin Health Innovation Research Institute, Curtin University, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia.
- Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute Building, 8 Verdun St, Nedlands, 6009, Western Australia, Australia.
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13
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Enhanced mitochondrial autophagy (mitophagy) in oligodendrocytes might play a role in white matter pathology in schizophrenia. Med Hypotheses 2019; 134:109443. [PMID: 31644973 DOI: 10.1016/j.mehy.2019.109443] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/11/2019] [Accepted: 10/17/2019] [Indexed: 01/09/2023]
Abstract
Disrupted white matter integrity is a typical feature of brain pathologic alterations in schizophrenia, which includes impaired myelination, decreased oligodendrocyte densities, distortion of their spatial distribution and deviations from normal oligodendrocyte cell morphology. While most genes expressed "in the remaining" oligodendrocytes are downregulated in schizophrenia, only a few are upregulated. To the latter group belong prohibitin 2 and DISC 1, which were recently identified as mitochondria-located mitophagy receptors. Their overexpression, together with greatly reduced numbers and densities of oligodendroglial mitochondria and the structurally "normal appearance of the remaining mitochondria" in these cells as reported by Uranova's group (Uranova et al., 2001, 2004, 2018), point to enhanced mitophagy in oligodendrocytes in schizophrenia, which is possibly even cell protective by preventing apoptosis. Since massive loss of white matter oligodendrocytes is a characteristic feature of schizophrenia, we assume that increased mitophagy is a late event in the development and/or further progression of white matter pathologic changes. Moreover, altered oligodendroglial mitophagy might in part result from antipsychotic treatment. Further studies are clearly needed to substantiate our hypothesis on enhanced mitochondrial autophagy in schizophrenia, whereby the "drug-naïve state" and the possible influence of antipsychotic treatment could be elegantly simulated using animal models of the disease.
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14
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Li WX, Qu Y, Mu DZ, Tang J. [A review on the relationship between mitochondrial dysfunction and white matter injury in preterm infants]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2018; 20:864-869. [PMID: 30369366 PMCID: PMC7389051 DOI: 10.7499/j.issn.1008-8830.2018.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/28/2018] [Indexed: 06/08/2023]
Abstract
White matter injury in preterm infants has a complex etiology and can lead to long-term neurocognitive and behavioral deficits, but there are still no specific treatment methods for this disease at present. More and more studies have shown that mitochondrial dysfunction plays an important role in the pathogenesis of white matter injury in preterm infants and might be a common subcellular mechanism of white matter developmental disorder, which involves oxidative stress, reduced ATP synthesis, and disequilibrium of calcium homeostasis. This article reviews the role of mitochondria in brain development and the mechanism of mitochondrial dysfunction, with a hope to perform early intervention of white matter injury in preterm infants by protecting mitochondrial function, so as to provide a reference for improving the neurodevelopmental outcome of preterm infants who survive.
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Affiliation(s)
- Wen-Xing Li
- Department of Pediatrics, West China Second Hospital, Sichuan University/Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu 610041, China.
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15
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Smith NM, Giacci MK, Gough A, Bailey C, McGonigle T, Black AMB, Clarke TO, Bartlett CA, Swaminathan Iyer K, Dunlop SA, Fitzgerald M. Inflammation and blood-brain barrier breach remote from the primary injury following neurotrauma. J Neuroinflammation 2018; 15:201. [PMID: 29981582 PMCID: PMC6035802 DOI: 10.1186/s12974-018-1227-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 06/15/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Following injury to the central nervous system, increased microglia, secretion of pro- and anti-inflammatory cytokines, and altered blood-brain barrier permeability, a hallmark of degeneration, are observed at and immediately adjacent to the injury site. However, few studies investigate how regions remote from the primary injury could also suffer from inflammation and secondary degeneration. METHODS Adult female Piebald-Viral-Glaxo (PVG) rats underwent partial transection of the right optic nerve, with normal, age-matched, unoperated animals as controls. Perfusion-fixed brains and right optic nerves were harvested for immunohistochemical assessment of inflammatory markers and blood-brain barrier integrity; fresh-frozen brains were used for multiplex cytokine analysis. RESULTS Immediately ventral to the optic nerve injury, immunointensity of both the pro-inflammatory biomarker inducible nitric oxide synthase (iNOS) and the anti-inflammatory biomarker arginase-1 (Arg1) increased at 7 days post-injury, with colocalization of iNOS and Arg1 immunoreactivity within individual cells. CD11b+ and CD45+ cells were increased 7 days post-injury, with altered BBB permeability still evident at this time. In the lower and middle optic tract and superior colliculus, IBA1+ resident microglia were first increased at 3 days; ED1+ and CD11b+ cells were first increased in the middle and upper tract and superior colliculus 7 days post-injury. Increased fibrinogen immunoreactivity indicative of altered BBB permeability was first observed in the contralateral upper tract at 3 days and middle tract at 7 days post-injury. Multiplex cytokine analysis of brain homogenates indicated significant increases in the pro-inflammatory cytokines, IL-2 and TNFα, and anti-inflammatory cytokine IL-10 1 day post-injury, decreasing to control levels at 3 days for TNFα and 7 days for IL-2. IL-10 was significantly elevated at 1 and 7 days post-injury with a dip at 3 days post-injury. CONCLUSIONS Partial injury to the optic nerve induces a complex remote inflammatory response, characterized by rapidly increased pro- and anti-inflammatory cytokines in brain homogenates, increased numbers of IBA1+ cells throughout the visual pathways, and increased CD11b+ and ED1+ inflammatory cells, particularly towards the synaptic terminals. BBB permeability can increase prior to inflammatory cell infiltration, dependent on the brain region.
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Affiliation(s)
- Nicole M Smith
- School of Molecular Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Marcus K Giacci
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Alexander Gough
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Charlotte Bailey
- School of Molecular Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Terence McGonigle
- Curtin Health Innovation Research Institute, Curtin University, Verdun St, Nedlands, Western Australia, Australia
| | - Anna M B Black
- Curtin Health Innovation Research Institute, Curtin University, Verdun St, Nedlands, Western Australia, Australia
| | - Thomas O Clarke
- Curtin Health Innovation Research Institute, Curtin University, Verdun St, Nedlands, Western Australia, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia.,Curtin Health Innovation Research Institute, Curtin University, Verdun St, Nedlands, Western Australia, Australia
| | - K Swaminathan Iyer
- School of Molecular Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Sarah A Dunlop
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Stirling Hwy, Perth, Western Australia, 6009, Australia. .,Curtin Health Innovation Research Institute, Curtin University, Verdun St, Nedlands, Western Australia, Australia. .,Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute, Verdun St, Nedlands, Western Australia, 6009, Australia.
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16
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Oligodendroglia Are Particularly Vulnerable to Oxidative Damage after Neurotrauma In Vivo. J Neurosci 2018; 38:6491-6504. [PMID: 29915135 DOI: 10.1523/jneurosci.1898-17.2018] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 05/13/2018] [Accepted: 05/16/2018] [Indexed: 01/13/2023] Open
Abstract
Loss of function following injury to the CNS is worsened by secondary degeneration of neurons and glia surrounding the injury and is initiated by oxidative damage. However, it is not yet known which cellular populations and structures are most vulnerable to oxidative damage in vivo Using Nanoscale secondary ion mass spectrometry (NanoSIMS), oxidative damage was semiquantified within cellular subpopulations and structures of optic nerve vulnerable to secondary degeneration, following a partial transection of the optic nerve in adult female PVG rats. Simultaneous assessment of cellular subpopulations and structures revealed oligodendroglia as the most vulnerable to DNA oxidation following injury. 5-Ethynyl-2'-deoxyuridine (EdU) was used to label cells that proliferated in the first 3 d after injury. Injury led to increases in DNA, protein, and lipid damage in oligodendrocyte progenitor cells and mature oligodendrocytes at 3 d, regardless of proliferative state, associated with a decline in the numbers of oligodendrocyte progenitor cells at 7 d. O4+ preoligodendrocytes also exhibited increased lipid peroxidation. Interestingly, EdU+ mature oligodendrocytes derived after injury demonstrated increased early susceptibility to DNA damage and lipid peroxidation. However, EdU- mature oligodendrocytes with high 8-hydroxyguanosine immunoreactivity were more likely to be caspase3+ By day 28, newly derived mature oligodendrocytes had significantly reduced myelin regulatory factor gene mRNA, indicating that the myelination potential of these cells may be reduced. The proportion of caspase3+ oligodendrocytes remained higher in EdU- cells. Innovative use of NanoSIMS together with traditional immunohistochemistry and in situ hybridization have enabled the first demonstration of subpopulation specific oligodendroglial vulnerability to oxidative damage, due to secondary degeneration in vivoSIGNIFICANCE STATEMENT Injury to the CNS is characterized by oxidative damage in areas adjacent to the injury. However, the cellular subpopulations and structures most vulnerable to this damage remain to be elucidated. Here we use powerful NanoSIMS techniques to show increased oxidative damage in oligodendroglia and axons and to demonstrate that cells early in the oligodendroglial lineage are the most vulnerable to DNA oxidation. Further immunohistochemical and in situ hybridization investigation reveals that mature oligodendrocytes derived after injury are more vulnerable to oxidative damage than their counterparts existing at the time of injury and have reduced myelin regulatory factor gene mRNA, yet preexisting oligodendrocytes are more likely to die.
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17
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Chiha W, LeVaillant CJ, Bartlett CA, Hewitt AW, Melton PE, Fitzgerald M, Harvey AR. Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury. PLoS One 2018; 13:e0192348. [PMID: 29425209 PMCID: PMC5806857 DOI: 10.1371/journal.pone.0192348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/20/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Partial transection (PT) of the optic nerve is an established experimental model of secondary degeneration in the central nervous system. After a dorsal transection, retinal ganglion cells (RGCs) with axons in ventral optic nerve are intact but vulnerable to secondary degeneration, whereas RGCs in dorsal retina with dorsal axons are affected by primary and secondary injuries. Using microarray, we quantified gene expression changes in dorsal and ventral retina at 1 and 7 days post PT, to characterize pathogenic pathways linked to primary and secondary degeneration. RESULTS In comparison to uninjured retina Cryba1, Cryba2 and Crygs, were significantly downregulated in injured dorsal retina at days 1 and 7. While Ecel1, Timp1, Mt2A and CD74, which are associated with reducing excitotoxicity, oxidative stress and inflammation, were significantly upregulated. Genes associated with oxygen binding pathways, immune responses, cytokine receptor activity and apoptosis were enriched in dorsal retina at day 1 after PT. Oxygen binding and apoptosis remained enriched at day 7, as were pathways involved in extracellular matrix modification. Fewer changes were observed in ventral retina at day 1 after PT, most associated with the regulation of protein homodimerization activity. By day 7, apoptosis, matrix organization and signal transduction pathways were enriched. Discriminant analysis was also performed for specific functional gene groups to compare expression intensities at each time point. Altered expression of selected genes (ATF3, GFAP, Ecel1, TIMP1, Tp53) and proteins (GFAP, ECEL1 and ATF3) were semi-quantitatively assessed by qRT-PCR and immunohistochemistry respectively. CONCLUSION There was an acute and complex primary injury response in dorsal retina indicative of a dynamic interaction between neuroprotective and neurodegenerative events; ventral retina vulnerable to secondary degeneration showed a delayed injury response. Both primary and secondary injury resulted in the upregulation of numerous genes linked to RGC death, but differences in the nature of these changes strongly suggest that death occurred via different molecular mechanisms.
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Affiliation(s)
- Wissam Chiha
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, WA, Australia
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Chrisna J. LeVaillant
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Carole A. Bartlett
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Alex W. Hewitt
- Lions Eye Institute, The University of Western Australia, Nedlands, WA, Australia
| | - Phillip E. Melton
- Curtin/UWA Centre for Genetic Origins of Health and Disease, School of Biomedical Science, The University of Western Australia and Curtin University, Bentley, WA, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, WA, Australia
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- Perron Institute for Neurological and Translational Science, QEII Medical Centre, Nedlands, WA, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Alan R. Harvey
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, WA, Australia
- School of Human Sciences, The University of Western Australia, Crawley, WA, Australia
- Perron Institute for Neurological and Translational Science, QEII Medical Centre, Nedlands, WA, Australia
- * E-mail:
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18
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The PGC-1α Activator ZLN005 Ameliorates Ischemia-Induced Neuronal Injury In Vitro and In Vivo. Cell Mol Neurobiol 2017; 38:929-939. [DOI: 10.1007/s10571-017-0567-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/14/2017] [Indexed: 01/02/2023]
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19
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Abstract
PURPOSE To examine the choroidal thickness in patients with indirect traumatic optic neuropathy (TON) Methods: Patients with unilateral traumatic optic neuropathy over a period of 4 years were included in this study. Horizontal and vertical enhanced-depth imaging (EDI) from spectral-domain optical coherence tomography (SD-OCT) scans of the fovea were obtained in patients with unilateral TON within 2 weeks of injury. The main outcome measure was the choroidal thickness at nine locations. The choroidal thickness was compared between affected and unaffected eyes in the TON group, and the mean difference in the choroidal thickness in both eyes was compared between TON and control groups. RESULTS A total of 16 patients and 20 control subjects were included. The choroidal thickness at horizontal, vertical and average subfoveal, inner temporal, and outer inferior locations was significantly thicker (13-23%) in affected eyes than in unaffected fellow eyes (p = 0.042, 0.046, 0.024, 0.013, 0.018, and 0.027, respectively). The mean difference value between choroidal thickness measurements in both eyes was significantly larger in the TON group than in the control group at the horizontal, vertical and average subfoveal, inner temporal, inner nasal, inner superior, inner inferior, and outer superior locations (p = 0.001, 0.011, <0.001, 0.001, 0.033, 0.014, 0.011, and 0.014, respectively). The choroidal thickness at subfoveal locations showed no statistical difference between TON and control eyes (p > 0.05). CONCLUSION Eyes affected by TON showed a regionally thicker choroid than unaffected fellow eye. This thick choroid might be due to impaired blood circulation and vascular remodeling of the optic nerve head and choroid. These results help to better understand the pathophysiology of TON.
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Affiliation(s)
- Ju-Yeun Lee
- a Department of Ophthalmology , Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , South Korea
| | - Doo-Ri Eo
- a Department of Ophthalmology , Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , South Korea
| | - Kyung-Ah Park
- a Department of Ophthalmology , Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , South Korea
| | - Sei Yeul Oh
- a Department of Ophthalmology , Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul , South Korea
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20
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O'Hare Doig RL, Chiha W, Giacci MK, Yates NJ, Bartlett CA, Smith NM, Hodgetts SI, Harvey AR, Fitzgerald M. Specific ion channels contribute to key elements of pathology during secondary degeneration following neurotrauma. BMC Neurosci 2017; 18:62. [PMID: 28806920 PMCID: PMC5557315 DOI: 10.1186/s12868-017-0380-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/05/2017] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Following partial injury to the central nervous system, cells beyond the initial injury site undergo secondary degeneration, exacerbating loss of neurons, compact myelin and function. Changes in Ca2+ flux are associated with metabolic and structural changes, but it is not yet clear how flux through specific ion channels contributes to the various pathologies. Here, partial optic nerve transection in adult female rats was used to model secondary degeneration. Treatment with combinations of three ion channel inhibitors was used as a tool to investigate which elements of oxidative and structural damage related to long term functional outcomes. The inhibitors employed were the voltage gated Ca2+ channel inhibitor Lomerizine (Lom), the Ca2+ permeable AMPA receptor inhibitor YM872 and the P2X7 receptor inhibitor oxATP. RESULTS Following partial optic nerve transection, hyper-phosphorylation of Tau and acetylated tubulin immunoreactivity were increased, and Nogo-A immunoreactivity was decreased, indicating that axonal changes occurred acutely. All combinations of ion channel inhibitors reduced hyper-phosphorylation of Tau and increased Nogo-A immunoreactivity at day 3 after injury. However, only Lom/oxATP or all three inhibitors in combination significantly reduced acetylated tubulin immunoreactivity. Most combinations of ion channel inhibitors were effective in restoring the lengths of the paranode and the paranodal gap, indicative of the length of the node of Ranvier, following injury. However, only all three inhibitors in combination restored to normal Ankyrin G length at the node of Ranvier. Similarly, HNE immunoreactivity and loss of oligodendrocyte precursor cells were only limited by treatment with all three ion channel inhibitors in combination. CONCLUSIONS Data indicate that inhibiting any of a range of ion channels preserves certain elements of axon and node structure and limits some oxidative damage following injury, whereas ionic flux through all three channels must be inhibited to prevent lipid peroxidation and preserve Ankyrin G distribution and OPCs.
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Affiliation(s)
- Ryan L O'Hare Doig
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Wissam Chiha
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Marcus K Giacci
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Nathanael J Yates
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Nicole M Smith
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Experimental and Regenerative Neurosciences, School of Chemistry and Biochemistry, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Stuart I Hodgetts
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Perron Institute for Neurological and Translational Science, Verdun St, Nedlands, WA, 6009, Australia
| | - Alan R Harvey
- Experimental and Regenerative Neurosciences, School of Human Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Perron Institute for Neurological and Translational Science, Verdun St, Nedlands, WA, 6009, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Crawley, WA, 6009, Australia. .,Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia. .,Perron Institute for Neurological and Translational Science, Verdun St, Nedlands, WA, 6009, Australia.
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21
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Yates NJ, Lydiard S, Fehily B, Weir G, Chin A, Bartlett CA, Alderson J, Fitzgerald M. Repeated mild traumatic brain injury in female rats increases lipid peroxidation in neurons. Exp Brain Res 2017; 235:2133-2149. [PMID: 28417146 DOI: 10.1007/s00221-017-4958-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 04/07/2017] [Indexed: 11/30/2022]
Abstract
Negative outcomes of mild traumatic brain injury (mTBI) can be exacerbated by repeated insult. Animal models of repeated closed-head mTBI provide the opportunity to define acute pathological mechanisms as the number of mTBI increases. Furthermore, little is known about the effects of mTBI impact site, and how this may affect brain function. We use a closed head, weight drop model of mTBI that allows head movement following impact, in adult female rats to determine the role of the number and location of mTBI on brain pathology and behaviour. Biomechanical assessment of two anatomically well-defined mTBI impact sites were used, anterior (bregma) and posterior (lambda). Location of the impact had no significant effect on impact forces (450 N), and the weight impact locations were on average 5.4 mm from the desired impact site. No between location vertical linear head kinematic differences were observed immediately following impact, however, in the 300 ms post-impact, significantly higher mean vertical head displacement and velocity were observed in the mTBI lambda trials. Breaches of the blood brain barrier were observed with three mTBI over bregma, associated with immunohistochemical indicators of damage. However, an increased incidence of hairline fractures of the skull and macroscopic haemorrhaging made bregma an unsuitable impact location to model repeated mTBI. Repeated mTBI over lambda did not cause skull fractures and were examined more comprehensively, with outcomes following one, two or three mTBI or sham, delivered at 1 day intervals, assessed on days 1-4. We observe a mild behavioural phenotype, with subtle deficits in cognitive function, associated with no identifiable neuroanatomical or inflammatory changes. However, an increase in lipid peroxidation in a subset of cortical neurons following two mTBI indicates increasing oxidative damage with repeated injury in female rats, supported by increased amyloid precursor protein immunoreactivity with three mTBI. This study of acute events following closed head mTBI identifies lipid peroxidation in neurons at the same time as cognitive deficits. Our study adds to existing literature, providing biomechanics data and demonstrating mild cognitive disturbances associated with diffuse injury, predominantly to grey matter, acutely following repeated mTBI.
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Affiliation(s)
- Nathanael J Yates
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Perth, Australia
| | - Stephen Lydiard
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Perth, Australia
| | - Brooke Fehily
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Perth, Australia
| | - Gillian Weir
- School of Sport Science, Exercise and Health, The University of Western Australia, Perth, WA, 6009, Australia
| | - Aaron Chin
- School of Sport Science, Exercise and Health, The University of Western Australia, Perth, WA, 6009, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Perth, Australia
| | - Jacqueline Alderson
- School of Sport Science, Exercise and Health, The University of Western Australia, Perth, WA, 6009, Australia.,Auckland University of Technology, Sports Performance Research Institute New Zealand (SPRINZ), Auckland, New Zealand
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Biological Sciences, The University of Western Australia, Perth, Australia. .,Curtin Health Innovation Research Institute, Curtin University, Bentley, Australia. .,Perron Institute for Nerurological and Translational Science, Sarich Neuroscience Research Institute, Verdun St, Nedlands, WA, 6009, Australia.
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22
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Yates NJ, Giacci MK, O'Hare Doig RL, Chiha W, Ashworth BE, Kenna J, Bartlett CA, Fitzgerald M. Delayed treatment of secondary degeneration following acute optic nerve transection using a combination of ion channel inhibitors. Neural Regen Res 2017; 12:307-316. [PMID: 28400815 PMCID: PMC5361517 DOI: 10.4103/1673-5374.200814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Studies have shown that a combined application of several ion channel inhibitors immediately after central nervous system injury can inhibit secondary degeneration. However, for clinical use, it is necessary to determine how long after injury the combined treatment of several ion channel inhibitors can be delayed and efficacy maintained. In this study, we delivered Ca2+ entry-inhibiting P2X7 receptor antagonist oxidized-ATP and AMPA receptor antagonist YM872 to the optic nerve injury site via an iPRECIO@ pump immediately, 6 hours, 24 hours and 7 days after partial optic nerve transection surgery. In addition, all of the ion channel inhibitor treated rats were administered with calcium channel antagonist lomerizine hydrochloride. It is important to note that as a result of implantation of the particular pumps required for programmable delivery of therapeutics directly to the injury site, seromas occurred in a significant proportion of animals, indicating infection around the pumps in these animals. Improvements in visual function were observed only when treatment was delayed by 6 hours; phosphorylated Tau was reduced when treatment was delayed by 24 hours or 7 days. Improvements in structure of node/paranode of Ranvier and reductions in oxidative stress indicators were also only observed when treatment was delayed for 6 hours, 24 hours, or 7 days. Benefits of ion channel inhibitors were only observed with time-delayed treatment, suggesting that delayed therapy of Ca2+ ion channel inhibitors produces better neuroprotective effects on secondary degeneration, at least in the presence of seromas.
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Affiliation(s)
- Nathanael J Yates
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Marcus K Giacci
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Ryan L O'Hare Doig
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; Department of Experimental and Regenerative Neurosciences, School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Wissam Chiha
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; Department of Experimental and Regenerative Neurosciences, School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Bethany E Ashworth
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Jade Kenna
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Carole A Bartlett
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Melinda Fitzgerald
- Department of Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
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O'Hare Doig RL, Bartlett CA, Smith NM, Hodgetts SI, Dunlop SA, Hool L, Fitzgerald M. Specific combinations of ion channel inhibitors reduce excessive Ca 2+ influx as a consequence of oxidative stress and increase neuronal and glial cell viability in vitro. Neuroscience 2016; 339:450-462. [PMID: 27725216 DOI: 10.1016/j.neuroscience.2016.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/15/2016] [Accepted: 10/02/2016] [Indexed: 01/02/2023]
Abstract
Combinations of Ca2+ channel inhibitors have been proposed as an effective means to prevent excess Ca2+ flux and death of neurons and glia following neurotrauma in vivo. However, it is not yet known if beneficial outcomes such as improved viability have been due to direct effects on intracellular Ca2+ concentrations. Here, the effects of combinations of Lomerizine (Lom), 2,3-dioxo-7-(1H-imidazol-1-yl)6-nitro-1,2,3,4-tetrahydro-1-quinoxalinyl]acetic acid monohydrate (YM872), 3,5-dimethyl-1-adamantanamine (memantine (Mem)) and/or adenosine 5'-triphosphate periodate oxidized sodium salt (oxATP) to block voltage-gated Ca2+ channels, Ca2+ permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, NMDA receptors and purinergic P2X7 receptors (P2X7R) respectively, on Ca2+ concentration and viability of rat primary mixed cortical (MC) cultures exposed to hydrogen peroxide (H2O2) insult, were assessed. The contribution of ryanodine-sensitive intracellular stores to intracellular Ca2+ concentration was also assessed. Live cell calcium imaging revealed that a 30min H2O2 insult induced a slow increase in intracellular Ca2+, in part from intracellular sources, associated with loss of cell viability by 6h. Most combinations of inhibitors that included oxATP significantly decreased Ca2+ influx and increased cell viability when administered simultaneously with H2O2. However, reductions in intracellular Ca2+ concentration were not always linked to improved cell viability. Examination of the density of specific cell subpopulations demonstrated that most combinations of inhibitors that included oxATP preserved NG2+ non-oligodendroglial cells, but preservation of astrocytes and neurons required additional inhibitors. Olig2+ oligodendroglia and ED-1+ activated microglia/macrophages were not preserved by any of the inhibitor combinations. These data indicate that following H2O2 insult, limiting intracellular Ca2+ entry via P2X7R is generally associated with increased cell viability. Protection of NG2+ non-oligodendroglial cells by Ca2+ channel inhibitor combinations may contribute to observed beneficial outcomes in vivo.
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Affiliation(s)
- Ryan L O'Hare Doig
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Nicole M Smith
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia; School of Chemistry and Biochemistry, The University of Western Australia, Crawley, Western Australia, Australia
| | - Stuart I Hodgetts
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Sarah A Dunlop
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Livia Hool
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Crawley, Western Australia, Australia; Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, The University of Western Australia, Crawley, Western Australia, Australia; School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia.
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Microglia-induced activation of non-canonical Wnt signaling aggravates neurodegeneration in demyelinating disorders. Mol Cell Biol 2016; 36:2728-2741. [PMID: 27550808 DOI: 10.1128/mcb.00139-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Oligodendrocytes are myelinating cells of the central nervous system. Multiple sclerosis (MS) is a demyelinating disease characterized by both myelin loss and neuronal degeneration. However, the molecular mechanisms underlying neuronal degeneration in demyelinating disorders are not fully understood. In the experimental autoimmune encephalomyelitis (EAE) demyelinating mouse model of MS, inflammatory microglia produce cytokines including interleukin-1β (IL-1β). Since microglia and non-canonical Wnt signaling components in neurons, such as the co-receptor Ror2, were observed in the spinal cord of EAE mice, we postulated that the interplay between activated microglia and spinal neurons under EAE conditions is mediated through non-canonical Wnt signaling. EAE treatment up-regulated in vivo expression of non-canonical Wnt signaling components in spinal neurons through microglial activation. In accordance with the neuronal degeneration detected in the EAE spinal cord in vivo, co-culture of spinal neurons with microglia or the application of recombinant IL-1β up-regulated non-canonical Wnt signaling, and induced neuronal cell death, which was suppressed by the inhibition of the Wnt-Ror2 pathway. Ectopic non-canonical Wnt signaling aggravated the demyelinating pathology in another MS mouse model due to Wnt5a-induced neurodegeneration. The linkage between activated microglia and neuronal Wnt-Ror2 signaling may provide a possible candidate target for therapeutic approaches to demyelinating disorders.
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25
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Automatic quantitative analysis of experimental primary and secondary retinal neurodegeneration: implications for optic neuropathies. Cell Death Discov 2016. [DOI: 10.1038/cddiscovery.2016.31 ecollection 2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Automatic quantitative analysis of experimental primary and secondary retinal neurodegeneration: implications for optic neuropathies. Cell Death Discov 2016; 2:16031. [PMID: 27551521 PMCID: PMC4979431 DOI: 10.1038/cddiscovery.2016.31] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/15/2016] [Indexed: 01/03/2023] Open
Abstract
Secondary neurodegeneration is thought to play an important role in the pathology of neurodegenerative disease, which potential therapies may target. However, the quantitative assessment of the degree of secondary neurodegeneration is difficult. The present study describes a novel algorithm from which estimates of primary and secondary degeneration are computed using well-established rodent models of partial optic nerve transection (pONT) and ocular hypertension (OHT). Brn3-labelled retinal ganglion cells (RGCs) were identified in whole-retinal mounts from which RGC density, nearest neighbour distances and regularity indices were determined. The spatial distribution and rate of RGC loss were assessed and the percentage of primary and secondary degeneration in each non-overlapping segment was calculated. Mean RGC number (82 592±681) and RGC density (1695±23.3 RGC/mm2) in naïve eyes were comparable with previous studies, with an average decline in RGC density of 71±17 and 23±5% over the time course of pONT and OHT models, respectively. Spatial analysis revealed greatest RGC loss in the superior and central retina in pONT, but significant RGC loss in the inferior retina from 3 days post model induction. In comparison, there was no significant difference between superior and inferior retina after OHT induction, and RGC loss occurred mainly along the superior/inferior axis (~30%) versus the nasal–temporal axis (~15%). Intriguingly, a significant loss of RGCs was also observed in contralateral eyes in experimental OHT. In conclusion, a novel algorithm to automatically segment Brn3a-labelled retinal whole-mounts into non-overlapping segments is described, which enables automated spatial and temporal segmentation of RGCs, revealing heterogeneity in the spatial distribution of primary and secondary degenerative processes. This method provides an attractive means to rapidly determine the efficacy of neuroprotective therapies with implications for any neurodegenerative disorder affecting the retina.
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Ashworth BE, Stephens E, Bartlett CA, Serghiou S, Giacci MK, Williams A, Hart NS, Fitzgerald M. Comparative assessment of phototherapy protocols for reduction of oxidative stress in partially transected spinal cord slices undergoing secondary degeneration. BMC Neurosci 2016; 17:21. [PMID: 27194427 PMCID: PMC4872332 DOI: 10.1186/s12868-016-0259-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 05/11/2016] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Red/near-infrared light therapy (R/NIR-LT) has been developed as a treatment for a range of conditions, including injury to the central nervous system (CNS). However, clinical trials have reported variable or sub-optimal outcomes, possibly because there are few optimized treatment protocols for the different target tissues. Moreover, the low absolute, and wavelength dependent, transmission of light by tissues overlying the target site make accurate dosing problematic. RESULTS In order to optimize light therapy treatment parameters, we adapted a mouse spinal cord organotypic culture model to the rat, and characterized myelination and oxidative stress following a partial transection injury. The ex vivo model allows a more accurate assessment of the relative effect of different illumination wavelengths (adjusted for equal quantal intensity) on the target tissue. Using this model, we assessed oxidative stress following treatment with four different wavelengths of light: 450 nm (blue); 510 nm (green); 660 nm (red) or 860 nm (infrared) at three different intensities: 1.93 × 10(16) (low); 3.85 × 10(16) (intermediate) and 7.70 × 10(16) (high) photons/cm(2)/s. We demonstrate that the most effective of the tested wavelengths to reduce immunoreactivity of the oxidative stress indicator 3-nitrotyrosine (3NT) was 660 nm. 860 nm also provided beneficial effects at all tested intensities, significantly reducing oxidative stress levels relative to control (p ≤ 0.05). CONCLUSIONS Our results indicate that R/NIR-LT is an effective antioxidant therapy, and indicate that effective wavelengths and ranges of intensities of treatment can be adapted for a variety of CNS injuries and conditions, depending upon the transmission properties of the tissue to be treated.
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Affiliation(s)
- Bethany Eve Ashworth
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
- />Department of Biology and Biochemistry, The University of Bath, Bath, UK
| | - Emma Stephens
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
- />Department of Biology and Biochemistry, The University of Bath, Bath, UK
| | - Carole A. Bartlett
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
| | - Stylianos Serghiou
- />Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Marcus K. Giacci
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
| | - Anna Williams
- />Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Nathan S. Hart
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
- />Department of Biological Sciences, Macquarie University, Sydney, NSW 2109 Australia
| | - Melinda Fitzgerald
- />Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, WA Australia
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28
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Smith NM, Gachulincova I, Ho D, Bailey C, Bartlett CA, Norret M, Murphy J, Buckley A, Rigby PJ, House MJ, St Pierre T, Fitzgerald M, Iyer KS, Dunlop SA. An Unexpected Transient Breakdown of the Blood Brain Barrier Triggers Passage of Large Intravenously Administered Nanoparticles. Sci Rep 2016; 6:22595. [PMID: 26940762 PMCID: PMC4778073 DOI: 10.1038/srep22595] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/18/2016] [Indexed: 12/24/2022] Open
Abstract
The highly restrictive blood-brain barrier (BBB) plays a critically important role in maintaining brain homeostasis and is pivotal for proper neuronal function. The BBB is currently considered the main limiting factor restricting the passage of large (up to 200 nm) intravenously administered nanoparticles to the brain. Breakdown of the barrier occurs as a consequence of cerebrovascular diseases and traumatic brain injury. In this article, we report that remote injuries in the CNS are also associated with BBB dysfunction. In particular, we show that a focal partial transection of the optic nerve triggers a previously unknown transient opening of the mammalian BBB that occurs in the visual centres. Importantly, we demonstrate that this transient BBB breakdown results in a dramatic change in the biodistribution of intravenously administered large polymeric nanoparticles which were previously deemed as BBB-impermeable.
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Affiliation(s)
- Nicole M Smith
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia.,School of Chemistry and Biochemistry, The University of Western Australia, Perth, WA 6009, Australia
| | - Ivana Gachulincova
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia
| | - Diwei Ho
- School of Chemistry and Biochemistry, The University of Western Australia, Perth, WA 6009, Australia
| | - Charlotte Bailey
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia
| | - Marck Norret
- School of Chemistry and Biochemistry, The University of Western Australia, Perth, WA 6009, Australia
| | - John Murphy
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia
| | - Alysia Buckley
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia
| | - Paul J Rigby
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia
| | - Michael J House
- School of Physics, The University of Western Australia, Perth, WA 6009, Australia
| | - Timothy St Pierre
- School of Physics, The University of Western Australia, Perth, WA 6009, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia
| | - K Swaminathan Iyer
- School of Chemistry and Biochemistry, The University of Western Australia, Perth, WA 6009, Australia
| | - Sarah A Dunlop
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Perth, WA 6009, Australia
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29
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Nita M, Grzybowski A. The Role of the Reactive Oxygen Species and Oxidative Stress in the Pathomechanism of the Age-Related Ocular Diseases and Other Pathologies of the Anterior and Posterior Eye Segments in Adults. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:3164734. [PMID: 26881021 PMCID: PMC4736974 DOI: 10.1155/2016/3164734] [Citation(s) in RCA: 818] [Impact Index Per Article: 102.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/18/2022]
Abstract
The reactive oxygen species (ROS) form under normal physiological conditions and may have both beneficial and harmful role. We search the literature and current knowledge in the aspect of ROS participation in the pathogenesis of anterior and posterior eye segment diseases in adults. ROS take part in the pathogenesis of keratoconus, Fuchs endothelial corneal dystrophy, and granular corneal dystrophy type 2, stimulating apoptosis of corneal cells. ROS play a role in the pathogenesis of glaucoma stimulating apoptotic and inflammatory pathways on the level of the trabecular meshwork and promoting retinal ganglion cells apoptosis and glial dysfunction in the posterior eye segment. ROS play a role in the pathogenesis of Leber's hereditary optic neuropathy and traumatic optic neuropathy. ROS induce apoptosis of human lens epithelial cells. ROS promote apoptosis of vascular and neuronal cells and stimulate inflammation and pathological angiogenesis in the course of diabetic retinopathy. ROS are associated with the pathophysiological parainflammation and autophagy process in the course of the age-related macular degeneration.
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Affiliation(s)
- Małgorzata Nita
- Domestic and Specialized Medicine Centre “Dilmed”, Ulica Bohaterów Monte Cassino 3, 40-231 Katowice, Poland
| | - Andrzej Grzybowski
- Department of Ophthalmology, Poznan City Hospital, Ulica Szwajcarska 3, 61-285 Poznań, Poland
- Chair of Ophthalmology, Medical Faculty, University of Warmia and Mazury, Ulica Żołnierska 14 C, 10-719 Olsztyn, Poland
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30
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Lozić I, Hartz RV, Bartlett CA, Shaw JA, Archer M, Naidu PSR, Smith NM, Dunlop SA, Iyer KS, Kilburn MR, Fitzgerald M. Enabling dual cellular destinations of polymeric nanoparticles for treatment following partial injury to the central nervous system. Biomaterials 2015; 74:200-16. [PMID: 26461115 DOI: 10.1016/j.biomaterials.2015.10.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 09/29/2015] [Accepted: 10/01/2015] [Indexed: 12/27/2022]
Abstract
Following neurotrauma, oxidative stress is spread via the astrocytic syncytium and is associated with increased aquaporin 4 (AQP4), inflammatory cell infiltration, loss of neurons and glia and functional deficits. Herein we evaluate multimodal polymeric nanoparticles functionalized with an antibody to an extracellular epitope of AQP4, for targeted delivery of an anti-oxidant as a therapeutic strategy following partial optic nerve transection. Using fluorescence microscopy, spectrophotometry, correlative nanoscale secondary ion mass spectrometry (NanoSIMS) and transmission electron microscopy, in vitro and in vivo, we demonstrate that functionalized nanoparticles are coated with serum proteins such as albumin and enter both macrophages and astrocytes when administered to the site of a partial optic nerve transection in rat. Antibody functionalized nanoparticles synthesized to deliver the antioxidant resveratrol are effective in reducing oxidative damage to DNA, AQP4 immunoreactivity and preserving visual function. Non-functionalized nanoparticles evade macrophages more effectively and are found more diffusely, including in astrocytes, however they do not preserve the optic nerve from oxidative damage or functional loss following injury. Our study highlights the need to comprehensively investigate nanoparticle location, interactions and effects, both in vitro and in vivo, in order to fully understand functional outcomes.
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Affiliation(s)
- I Lozić
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia; Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - R V Hartz
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - C A Bartlett
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - J A Shaw
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - M Archer
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - P S R Naidu
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia; Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - N M Smith
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia; Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - S A Dunlop
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - K Swaminathan Iyer
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - M R Kilburn
- Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
| | - M Fitzgerald
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia.
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31
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Direct optic nerve sheath (DONS) application of Schwann cells prolongs retinal ganglion cell survival in vivo. Cell Death Dis 2014; 5:e1460. [PMID: 25321467 PMCID: PMC4237238 DOI: 10.1038/cddis.2014.399] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 08/06/2014] [Accepted: 08/08/2014] [Indexed: 01/10/2023]
Abstract
Cell-based therapies are increasingly recognized as a potential strategy to treat retinal neurodegenerative disease. Their administration, however, is normally indirect and complex, often with an inability to assess in real time their effects on cell death and their migration/integration into the host retina. In the present study, using a partial optic nerve transection (pONT) rat model, we describe a new method of Schwann cell (SC) delivery (direct application to injured optic nerve sheath, SC/DONS), which was compared with intravitreal SC delivery (SC/IVT). Both SC/DONS and SC/IVT were able to be assessed in vivo using imaging to visualize retinal ganglion cell (RGC) apoptosis and SC retinal integration. RGC death in the pONT model was best fitted to the one-phase exponential decay model. Although both SC/DONS and SC/IVT altered the temporal course of RGC degeneration in pONT, SC/DONS resulted in delayed but long-lasting effects on RGC protection, compared with SC/IVT treatment. In addition, their effects on primary and secondary degeneration, and axonal regeneration, were also investigated, by histology, whole retinal counting, and modelling of RGC loss. SC/DONS was found to significantly reduce RGC apoptosis in vivo and significantly increase RGC survival by targeting secondary rather than primary degeneration. Both SC/DONS and SC/IVT were found to promote RGC axonal regrowth after optic nerve injury, with evidence of GAP-43 expression in RGC somas and axons. SC/DONS may have the potential in the treatment of optic neuropathies, such as glaucoma. We show that SC transplantation can be monitored in real time and that the protective effects of SCs are associated with targeting secondary degeneration, with implications for translating cell-based therapies to the clinic.
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