1
|
Plafker SM, Titcomb T, Zyla-Jackson K, Kolakowska A, Wahls T. Overview of diet and autoimmune demyelinating optic neuritis: a narrative review. IMMUNOMETABOLISM (COBHAM, SURREY) 2023; 5:e00022. [PMID: 37128292 PMCID: PMC10144304 DOI: 10.1097/in9.0000000000000022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 03/29/2023] [Indexed: 05/03/2023]
Abstract
This review summarizes the cellular and molecular underpinnings of autoimmune demyelinating optic neuritis (ADON), a common sequela of multiple sclerosis and other demyelinating diseases. We further present nutritional interventions tested for people with multiple sclerosis focusing on strategies that have shown efficacy or associations with disease course and clinical outcomes. We then close by discuss the potential dietary guidance for preventing and/or ameliorating ADON.
Collapse
Affiliation(s)
- Scott M. Plafker
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Tyler Titcomb
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Katarzyna Zyla-Jackson
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Aneta Kolakowska
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Terry Wahls
- Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
2
|
Treatment with MDL 72527 Ameliorated Clinical Symptoms, Retinal Ganglion Cell Loss, Optic Nerve Inflammation, and Improved Visual Acuity in an Experimental Model of Multiple Sclerosis. Cells 2022; 11:cells11244100. [PMID: 36552864 PMCID: PMC9776605 DOI: 10.3390/cells11244100] [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: 09/25/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Multiple Sclerosis (MS) is a highly disabling neurological disease characterized by inflammation, neuronal damage, and demyelination. Vision impairment is one of the major clinical features of MS. Previous studies from our lab have shown that MDL 72527, a pharmacological inhibitor of spermine oxidase (SMOX), is protective against neurodegeneration and inflammation in the models of diabetic retinopathy and excitotoxicity. In the present study, utilizing the experimental autoimmune encephalomyelitis (EAE) model of MS, we determined the impact of SMOX blockade on retinal neurodegeneration and optic nerve inflammation. The increased expression of SMOX observed in EAE retinas was associated with a significant loss of retinal ganglion cells, degeneration of synaptic contacts, and reduced visual acuity. MDL 72527-treated mice exhibited markedly reduced motor deficits, improved neuronal survival, the preservation of synapses, and improved visual acuity compared to the vehicle-treated group. The EAE-induced increase in macrophage/microglia was markedly reduced by SMOX inhibition. Upregulated acrolein conjugates in the EAE retina were decreased through MDL 72527 treatment. Mechanistically, the EAE-induced ERK-STAT3 signaling was blunted by SMOX inhibition. In conclusion, our studies demonstrate the potential benefits of targeting SMOX to treat MS-mediated neuroinflammation and vision loss.
Collapse
|
3
|
Lucchesi M, Marracci S, Amato R, Filippi L, Cammalleri M, Dal Monte M. Neurosensory Alterations in Retinopathy of Prematurity: A Window to Neurological Impairments Associated to Preterm Birth. Biomedicines 2022; 10:biomedicines10071603. [PMID: 35884908 PMCID: PMC9313429 DOI: 10.3390/biomedicines10071603] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 06/21/2022] [Accepted: 07/04/2022] [Indexed: 11/16/2022] Open
Abstract
Retinopathy of prematurity (ROP) is one of the main blinding diseases affecting preterm newborns and is classically considered a vascular disorder. The premature exposure to the extrauterine environment, which is hyperoxic in respect to the intrauterine environment, triggers a cascade of events leading to retinal ischemia which, in turn, makes the retina hypoxic thus setting off angiogenic processes. However, many children with a history of ROP show persistent vision impairment, and there is evidence of an association between ROP and neurosensory disabilities. This is not surprising given the strict relationship between neuronal function and an adequate blood supply. In the present work, we revised literature data evidencing to what extent ROP can be considered a neurodegenerative disease, also taking advantage from data obtained in preclinical models of ROP. The involvement of different retinal cell populations in triggering the neuronal damage in ROP was described along with the neurological outcomes associated to ROP. The situation of ROP in Italy was assessed as well.
Collapse
Affiliation(s)
- Martina Lucchesi
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (M.C.)
| | - Silvia Marracci
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (M.C.)
| | - Rosario Amato
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (M.C.)
| | - Luca Filippi
- Department of Clinical and Experimental Medicine, Division of Neonatology and NICU, University of Pisa, 56126 Pisa, Italy;
| | - Maurizio Cammalleri
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (M.C.)
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (M.C.)
- Correspondence: ; Tel.: +39-050-2211426
| |
Collapse
|
4
|
Roles of Fatty Acids in Microglial Polarization: Evidence from In Vitro and In Vivo Studies on Neurodegenerative Diseases. Int J Mol Sci 2022; 23:ijms23137300. [PMID: 35806302 PMCID: PMC9266841 DOI: 10.3390/ijms23137300] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 02/04/2023] Open
Abstract
Microglial polarization to the M1 phenotype (classically activated) or the M2 phenotype (alternatively activated) is critical in determining the fate of immune responses in neurodegenerative diseases (NDs). M1 macrophages contribute to neurotoxicity, neuronal and synaptic damage, and oxidative stress and are the first line of defense, and M2 macrophages elicit an anti-inflammatory response to regulate neuroinflammation, clear cell debris, and promote neuroregeneration. Various studies have focused on the ability of natural compounds to promote microglial polarization from the M1 phenotype to the M2 phenotype in several diseases, including NDs. However, studies on the roles of fatty acids in microglial polarization and their implications in NDs are a rare find. Most of the studies support the role of polyunsaturated fatty acids (PUFAs) in microglial polarization using cell and animal models. Thus, we aimed to collect data and provide a narrative account of microglial types, markers, and studies pertaining to fatty acids, particularly PUFAs, on microglial polarization and their neuroprotective effects. The involvement of only PUFAs in the chosen topic necessitates more in-depth research into the role of unexplored fatty acids in microglial polarization and their mechanistic implications. The review also highlights limitations and future challenges.
Collapse
|
5
|
Yu H, Bai S, Hao Y, Guan Y. Fatty acids role in multiple sclerosis as "metabokines". J Neuroinflammation 2022; 19:157. [PMID: 35715809 PMCID: PMC9205055 DOI: 10.1186/s12974-022-02502-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 06/01/2022] [Indexed: 12/21/2022] Open
Abstract
Multiple sclerosis (MS), as an autoimmune neurological disease with both genetic and environmental contribution, still lacks effective treatment options among progressive patients, highlighting the need to re-evaluate disease innate properties in search for novel therapeutic targets. Fatty acids (FA) and MS bear an interesting intimate connection. FA and FA metabolism are highly associated with autoimmunity, as the diet-derived circulatory and tissue-resident FAs level and composition can modulate immune cells polarization, differentiation and function, suggesting their broad regulatory role as “metabokines”. In addition, FAs are indeed protective factors for blood–brain barrier integrity, crucial contributors of central nervous system (CNS) chronic inflammation and progressive degeneration, as well as important materials for remyelination. The remaining area of ambiguity requires further exploration into this arena to validate the existed phenomenon, develop novel therapies, and confirm the safety and efficacy of therapeutic intervention targeting FA metabolism.
Collapse
Affiliation(s)
- Haojun Yu
- Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong, Shanghai, 200127, China
| | - Shuwei Bai
- Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong, Shanghai, 200127, China
| | - Yong Hao
- Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong, Shanghai, 200127, China.
| | - Yangtai Guan
- Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, 160 Pujian Road, Pudong, Shanghai, 200127, China.
| |
Collapse
|
6
|
Luo J, Lian Q, Zhu D, Zhao M, Mei T, Shang B, Yang Z, Liu C, Xu W, Zhou L, Wu K, Liu X, Lai Y, Mao F, Li W, Zuo C, Zhang K, Lin M, Zhuo Y, Liu Y, Lu L, Zhao L. PLSCR1 Promotes Apoptosis and Clearance of Retinal Ganglion Cells in Glaucoma Pathogenesis. Genes Dis 2022. [DOI: 10.1016/j.gendis.2022.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
7
|
Matrine treatment reduces retinal ganglion cell apoptosis in experimental optic neuritis. Sci Rep 2021; 11:9520. [PMID: 33947942 PMCID: PMC8097076 DOI: 10.1038/s41598-021-89086-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 04/20/2021] [Indexed: 11/25/2022] Open
Abstract
Inflammatory demyelination and axonal injury of the optic nerve are hallmarks of optic neuritis (ON), which often occurs in multiple sclerosis and is a major cause of visual disturbance in young adults. Although a high dose of corticosteroids can promote visual recovery, it cannot prevent permanent neuronal damage. Novel and effective therapies are thus required. Given the recently defined capacity of matrine (MAT), a quinolizidine alkaloid derived from the herb Radix Sophorae flavescens, in immunomodulation and neuroprotection, we tested in this study the effect of matrine on rats with experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. MAT administration, started at disease onset, significantly suppressed optic nerve infiltration and demyelination, with reduced numbers of Iba1+ macrophages/microglia and CD4+ T cells, compared to those from vehicle-treated rats. Increased expression of neurofilaments, an axon marker, reduced numbers of apoptosis in retinal ganglion cells (RGCs). Moreover, MAT treatment promoted Akt phosphorylation and shifted the Bcl-2/Bax ratio back towards an antiapoptotic one, which could be a mechanism for its therapeutic effect in the ON model. Taken as a whole, our results demonstrate that MAT attenuated inflammation, demyelination and axonal loss in the optic nerve, and protected RGCs from inflammation-induced cell death. MAT may therefore have potential as a novel treatment for this disease that may result in blindness.
Collapse
|
8
|
Abstract
Optic neuritis (ON) is an inflammatory attack of the optic nerve that leads to visual disability. It is the most common optic neuropathy affecting healthy young adults, most commonly women aged 20-45 years. It can be idiopathic and monophasic or as part of a neurologic disease such as multiple sclerosis with recurrence and cumulative damage. Currently, there is no therapy to repair the damage from optic neuritis. Animal models are an essential tool for the understanding of the pathogenesis of optic neuritis and for the development of potential treatment strategies. Experimental autoimmune encephalomyelitis (EAE) is the most commonly used experimental rodent model for human autoimmune inflammatory demyelinating diseases of the central nervous system (CNS). In this review, we discuss the latest rodent models regarding optic neuritis, focusing on EAE model, and on its recent achievements and developments.
Collapse
Affiliation(s)
- Yael Redler
- Department of Neuro-Ophthalmology, Massachusetts Eye & Ear Infirmary/Harvard Medical School, Boston, MA, United States
| | - Michael Levy
- Department of Neurology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, United States
| |
Collapse
|
9
|
Jung E, Jung WK, Park S, Kim HR, Kim J. Aucuba japonica extract inhibits retinal neovascularization in a mouse model of oxygen-induced retinopathy, with its bioactive components preventing VEGF-induced retinal vascular hyperpermeability. Food Sci Nutr 2020; 8:2895-2903. [PMID: 32566207 PMCID: PMC7300051 DOI: 10.1002/fsn3.1590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/19/2020] [Accepted: 03/30/2020] [Indexed: 12/27/2022] Open
Abstract
Neovascularization in the retina is common pathophysiology of diabetic retinal microvasculopathy and exudative macular degeneration. Our study assessed the inhibitory activity of an ethanol-based extract of Aucuba japonica (AJE) on abnormal angiogenesis in the retina with a hyperoxia-induced neovascular retinopathy model. The inhibitory effects of aucubin, quercetin, and kaempferol, bioactive compounds, from A. japonica, on retinal vascular hyperpermeability were also examined. On the 7th postnatal day (P7), the C57BL/6 pups were exposed to a hyperoxic environment with 75% oxygen to develop the experimental angiogenesis in retinas. On the 12th postnatal day (P12), the pups were then returned to the normal atmospheric pressure of oxygen. From P12 to P16, the administration was intraperitoneal. The dose per day was 250 mg per kg weight. Retinal neovascularization was measured with retinal flat mounts prepared on P17. We also measured the vascular leakage mediated by the vascular endothelial growth factor (VEGF) in retinas. Mice treated with AJE had markedly smaller neovascular lesions, in comparison with vehicle-administered mice. AJE downregulated the expression of both VEGF protein and mRNA. In addition, aucubin, quercetin, and kaempferol ameliorated VEGF-induced retinal vascular leakage. The results of our study suggest that AJE is a potent antiangiogenic substance. AJE could also serve as a therapeutic agent for abnormal growth of vessels in the retina in patients with ischemic retinopathy. The bioactive compounds of AJE may be responsible for its antiangiogenic abilities.
Collapse
Affiliation(s)
- Eunsoo Jung
- Laboratory of ToxicologyResearch Institute for Veterinary Science and College of Veterinary MedicineSeoul National UniversitySeoulKorea
| | - Woo Kwon Jung
- Department of Oral PathologySchool of DentistryJeonbuk National UniversityJeonjuKorea
| | - Su‐Bin Park
- Department of Oral PathologySchool of DentistryJeonbuk National UniversityJeonjuKorea
| | - Hyung Rae Kim
- Department of Oral PathologySchool of DentistryJeonbuk National UniversityJeonjuKorea
| | - Junghyun Kim
- Department of Oral PathologySchool of DentistryJeonbuk National UniversityJeonjuKorea
| |
Collapse
|
10
|
Neurotoxicity of nanoparticles entering the brain via sensory nerve-to-brain pathways: injuries and mechanisms. Arch Toxicol 2020; 94:1479-1495. [DOI: 10.1007/s00204-020-02701-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 03/05/2020] [Indexed: 12/15/2022]
|
11
|
Assessing the anterior visual pathway in optic neuritis: recent experimental and clinical aspects. Curr Opin Neurol 2020; 32:346-357. [PMID: 30694926 DOI: 10.1097/wco.0000000000000675] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Multiple sclerosis (MS) and related autoimmune disorders of the central nervous system such as neuromyelitis optica spectrum disorders (NMOSD) are characterized by chronic disability resulting from autoimmune neuroinflammation, with demyelination, astrocyte damage, impaired axonal transmission and neuroaxonal loss. Novel therapeutics stopping or reversing the progression of disability are still urgently warranted. This review addresses research on optic neuritis in preclinical experimental models and their translation to clinical trials. RECENT FINDINGS Optic neuritis can be used as paradigm for an MS relapse which can serve to evaluate the efficacy of novel therapeutics in clinical trials with a reasonable duration and cohort size. The advantage is the linear structure of the visual pathway allowing the assessment of visual function and retinal structure as highly sensitive outcome parameters. Experimental autoimmune encephalomyelitis is an inducible, inflammatory and demyelinating central nervous system disease extensively used as animal model of MS. Optic neuritis is part of the clinicopathological manifestations in a number of experimental autoimmune encephalomyelitis models. These have gained increasing interest for studies evaluating neuroprotective and/or remyelinating substances as longitudinal, visual and retinal readouts have become available. SUMMARY Translation of preclinical experiments, evaluating neuroprotective or remyelinating therapeutics to clinical studies is challenging. In-vivo readouts like optical coherence tomography, offers the possibility to transfer experimental study designs to clinical optic neuritis trials.
Collapse
|
12
|
Palani CD, Fouda AY, Liu F, Xu Z, Mohamed E, Giri S, Smith SB, Caldwell RB, Narayanan SP. Deletion of Arginase 2 Ameliorates Retinal Neurodegeneration in a Mouse Model of Multiple Sclerosis. Mol Neurobiol 2019; 56:8589-8602. [PMID: 31280447 DOI: 10.1007/s12035-019-01691-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022]
Abstract
Optic neuritis is a major clinical feature of multiple sclerosis (MS) and can lead to temporary or permanent vision loss. Previous studies from our laboratory have demonstrated the critical involvement of arginase 2 (A2) in retinal neurodegeneration in models of ischemic retinopathy. The current study was undertaken to investigate the role of A2 in MS-mediated retinal neuronal damage and degeneration. Experimental autoimmune encephalomyelitis (EAE) was induced in wild-type (WT) and A2 knockout (A2-/-) mice. EAE-induced motor deficits, loss of retinal ganglion cells, retinal thinning, inflammatory signaling, and glial activation were studied in EAE-treated WT and A2-/- mice and their respective controls. Increased expression of A2 was observed in WT retinas in response to EAE induction. EAE-induced motor deficits were markedly reduced in A2-/- mice compared with WT controls. Retinal flat mount studies demonstrated a significant reduction in the number of RGCs in WT EAE retinas in comparison with normal control mice. A significant improvement in neuronal survival was evident in retinas of EAE-induced A2-/- mice compared with WT. RNA levels of the proinflammatory molecules CCL2, COX2, IL-1α, and IL-12α were significantly reduced in the A2-/- EAE retinas compared with WT EAE. EAE-induced activation of glia (microglia and Müller cells) was markedly reduced in A2-/- retinas compared with WT. Western blot analyses showed increased levels of phospho-ERK1/2 and reduced levels of phospho-BAD in the WT EAE retina, while these changes were prevented in A2-/- mice. In conclusion, our studies establish EAE as an excellent model to study MS-mediated retinal neuronal damage and suggest the potential value of targeting A2 as a therapy to prevent MS-mediated retinal neuronal injury.
Collapse
Affiliation(s)
- Chithra D Palani
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30912, USA
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
| | - Abdelrahman Y Fouda
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
| | - Fang Liu
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30912, USA
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
| | - Zhimin Xu
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
| | - Eslam Mohamed
- Georgia Cancer Center, Augusta University, Augusta, GA, 30912, USA
- Department of Immunology, Moffitt Cancer Center, Tampa, FL, 33612, USA
| | - Shailedra Giri
- Department of Neurology, Henry Ford Health System, Detroit, MI, 48202, USA
| | - Sylvia B Smith
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA
| | - Ruth B Caldwell
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA
- Charlie Norwood VA Medical Center, Augusta, GA, 30904, USA
| | - S Priya Narayanan
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia, Augusta, GA, 30912, USA.
- Culver Vision Discovery Institute, Augusta University, Augusta, GA, 30912, USA.
- Vascular Biology Center, Augusta University, Augusta, GA, 30912, USA.
- Charlie Norwood VA Medical Center, Augusta, GA, 30904, USA.
| |
Collapse
|
13
|
Locri F, Cammalleri M, Pini A, Dal Monte M, Rusciano D, Bagnoli P. Further Evidence on Efficacy of Diet Supplementation with Fatty Acids in Ocular Pathologies: Insights from the EAE Model of Optic Neuritis. Nutrients 2018; 10:nu10101447. [PMID: 30301197 PMCID: PMC6213612 DOI: 10.3390/nu10101447] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 09/29/2018] [Accepted: 10/01/2018] [Indexed: 12/18/2022] Open
Abstract
In the experimental autoimmune encephalomyelitis (EAE) mouse model of optic neuritis, we recently demonstrated that diet supplementation with a balanced mixture of fatty acids (FAs), including omega 3 and omega 6, efficiently limited inflammatory events in the retina and prevented retinal ganglion cell (RGC) death, although mechanisms underlying the efficacy of FAs were to be elucidated. Whether FAs effectiveness was accompanied by efficient rescue of demyelinating events in the optic nerve was also unresolved. Finally, the possibility that RGC rescue might result in ameliorated visual performance remained to be investigated. Here, the EAE model of optic neuritis was used to investigate mechanisms underlying the anti-inflammatory effects of FAs, including their potential efficacy on macrophage polarization. In addition, we determined how FAs-induced rescue of RGC degeneration was related to optic nerve histopathology by performing ultrastructural morphometric analysis with transmission electron microscopy. Finally, RGC rescue was correlated with visual performance by recording photopic electroretinogram, an efficient methodology to unravel the role of RGCs in the generation of electroretinographic waves. We conclude that the ameliorative effects of FAs were dependent on a predominant anti-inflammatory action including a role on promoting the shift of macrophages from the inflammatory M1 phenotype towards the anti-inflammatory M2 phenotype. This would finally result in restored optic nerve histopathology and ameliorated visual performance. These findings can now offer new perspectives for implementing our knowledge on the effectiveness of diet supplementation in counteracting optic neuritis and suggest the importance of FAs as possible adjuvants in therapies against inflammatory diseases of the eye.
Collapse
MESH Headings
- Animals
- Anti-Inflammatory Agents/pharmacology
- Anti-Inflammatory Agents/therapeutic use
- Cell Death
- Dietary Supplements
- Electroretinography
- Encephalomyelitis, Autoimmune, Experimental/drug therapy
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Fatty Acids, Omega-3/pharmacology
- Fatty Acids, Omega-3/therapeutic use
- Fatty Acids, Omega-6/pharmacology
- Fatty Acids, Omega-6/therapeutic use
- Female
- Inflammation/drug therapy
- Inflammation/etiology
- Macrophages/drug effects
- Mice, Inbred C57BL
- Microscopy, Electron, Transmission/methods
- Neuroprotective Agents/pharmacology
- Neuroprotective Agents/therapeutic use
- Optic Nerve/drug effects
- Optic Nerve/pathology
- Optic Neuritis/drug therapy
- Optic Neuritis/etiology
- Optic Neuritis/pathology
- Retinal Ganglion Cells/drug effects
- Retinal Ganglion Cells/pathology
- Visual Acuity
Collapse
Affiliation(s)
- Filippo Locri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
| | - Maurizio Cammalleri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood ''Nutraceuticals and Food for Health'', University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Alessandro Pini
- Department of Experimental and Clinical Medicine, University of Florence, Viale Pieraccini 6, 50139 Firenze, Italy.
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood ''Nutraceuticals and Food for Health'', University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Dario Rusciano
- Sooft Italia SpA, Contrada Molino 17, 63833 Montegiorgio (FM), Italy.
| | - Paola Bagnoli
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
| |
Collapse
|