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Khalil A, Barras A, Boukherroub R, Tseng CL, Devos D, Burnouf T, Neuhaus W, Szunerits S. Enhancing paracellular and transcellular permeability using nanotechnological approaches for the treatment of brain and retinal diseases. NANOSCALE HORIZONS 2023; 9:14-43. [PMID: 37853828 DOI: 10.1039/d3nh00306j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Paracellular permeability across epithelial and endothelial cells is, in large part, regulated by apical intercellular junctions also referred to as tight junctions (TJs). These junctions contribute to the spatial definition of different tissue compartments within organisms, separating them from the outside world as well as from inner compartments, with their primary physiological role of maintaining tissue homeostasis. TJs restrict the free, passive diffusion of ions and hydrophilic small molecules through paracellular clefts and are important for appropriate cell polarization and transporter protein localisation, supporting the controlled transcellular diffusion of smaller and larger hydrophilic as well as hydrophobic substances. This traditional diffusion barrier concept of TJs has been challenged lately, owing to a better understanding of the components that are associated with TJs. It is now well-established that mutations in TJ proteins are associated with a range of human diseases and that a change in the membrane fluidity of neighbouring cells can open possibilities for therapeutics to cross intercellular junctions. Nanotechnological approaches, exploiting ultrasound or hyperosmotic agents and permeation enhancers, are the paradigm for achieving enhanced paracellular diffusion. The other widely used transport route of drugs is via transcellular transport, allowing the passage of a variety of pro-drugs and nanoparticle-encapsulated drugs via different mechanisms based on receptors and others. For a long time, there was an expectation that lipidic nanocarriers and polymeric nanostructures could revolutionize the field for the delivery of RNA and protein-based therapeutics across different biological barriers equipped with TJs (e.g., blood-brain barrier (BBB), retina-blood barrier (RBB), corneal TJs, etc.). However, only a limited increase in therapeutic efficiency has been reported for most systems until now. The purpose of this review is to explore the reasons behind the current failures and to examine the emergence of synthetic and cell-derived nanomaterials and nanotechnological approaches as potential game-changers in enhancing drug delivery to target locations both at and across TJs using innovative concepts. Specifically, we will focus on recent advancements in various nanotechnological strategies enabling the bypassing or temporally opening of TJs to the brain and to the retina, and discuss their advantages and limitations.
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Affiliation(s)
- Asmaa Khalil
- Univ. Lille, CNRS, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France.
| | - Alexandre Barras
- Univ. Lille, CNRS, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France.
| | - Rabah Boukherroub
- Univ. Lille, CNRS, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France.
| | - Ching-Li Tseng
- Taipei Medical University, Graduate Institute of Biomedical Materials and Tissue Engineering (GIBMTE), New Taipei City 235603, Taiwan
- Taipei Medical University, International PhD Program in Biomedical Engineering (IPBME), New Taipei City 235603, Taiwan
| | - David Devos
- University Lille, CHU-Lille, Inserm, U1172, Lille Neuroscience & Cognition, LICEND, Lille, France
| | - Thierry Burnouf
- Taipei Medical University, Graduate Institute of Biomedical Materials and Tissue Engineering (GIBMTE), New Taipei City 235603, Taiwan
- Taipei Medical University, International PhD Program in Biomedical Engineering (IPBME), New Taipei City 235603, Taiwan
| | - Winfried Neuhaus
- AIT - Austrian Institute of Technology GmbH, Center Health and Bioresources, Competence Unit Molecular Diagnostics, 1210 Vienna, Austria
- Laboratory for Life Sciences and Technology (LiST), Faculty of Medicine and Dentistry, Danube Private University, 3500 Krems, Austria
| | - Sabine Szunerits
- Univ. Lille, CNRS, Univ. Polytechnique Hauts-de-France, UMR 8520 - IEMN, F-59000 Lille, France.
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McCartan R, Gratkowski A, Browning M, Hahn-Townsend C, Ferguson S, Morin A, Bachmeier C, Pearson A, Brown L, Mullan M, Crawford F, Tzekov R, Mouzon B. Human amnionic progenitor cell secretome mitigates the consequence of traumatic optic neuropathy in a mouse model. Mol Ther Methods Clin Dev 2023; 29:303-318. [PMID: 37359418 PMCID: PMC10285248 DOI: 10.1016/j.omtm.2023.04.002] [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: 01/02/2023] [Accepted: 04/12/2023] [Indexed: 06/28/2023]
Abstract
Traumatic optic neuropathy (TON) is a condition in which acute injury to the optic nerve from direct or indirect trauma results in vision loss. The most common cause of TON is indirect injury to the optic nerve caused by concussive forces that are transmitted to the optic nerve. TON occurs in up to 5% of closed-head trauma patients and there is currently no known effective treatment. One potential treatment option for TON is ST266, a cell-free biological solution containing the secretome of amnion-derived multipotent progenitor (AMP) cells. We investigated the efficacy of intranasal ST266 in a mouse model of TON induced by blunt head trauma. Injured mice treated with a 10-day regimen of ST266 showed an improvement in spatial memory and learning, a significant preservation of retinal ganglion cells, and a decrease in neuropathological markers in the optic nerve, optic tract, and dorsal lateral geniculate nucleus. ST266 treatment effectively downregulated the NLRP3 inflammasome-mediated neuroinflammation pathway after blunt trauma. Overall, treatment with ST266 was shown to improve functional and pathological outcomes in a mouse model of TON, warranting future exploration of ST266 as a cell-free therapeutic candidate for testing in all optic neuropathies.
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Affiliation(s)
- Robyn McCartan
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | | | | | | | - Scott Ferguson
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Alexander Morin
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Corbin Bachmeier
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- Bay Pines Veterans’ Hospital, Saint Petersburg, FL 33708, USA
| | - Andrew Pearson
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Larry Brown
- Noveome Biotherapeutics, Inc., Pittsburgh, PA 15219, USA
| | - Michael Mullan
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Fiona Crawford
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- James A. Haley Veterans’ Hospital, Tampa, FL 33612, USA
| | | | - Benoit Mouzon
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- James A. Haley Veterans’ Hospital, Tampa, FL 33612, USA
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Yue J, Khan RS, Duong TT, Dine KE, Cui QN, O'Neill N, Aravand P, Liu T, Chaqour B, Shindler KS, Ross AG. Cell-Specific Expression of Human SIRT1 by Gene Therapy Reduces Retinal Ganglion Cell Loss Induced by Elevated Intraocular Pressure. Neurotherapeutics 2023; 20:896-907. [PMID: 36941497 PMCID: PMC10275821 DOI: 10.1007/s13311-023-01364-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2023] [Indexed: 03/23/2023] Open
Abstract
SIRT1 prevents retinal ganglion cell (RGC) loss in several acute and subacute optic neuropathy models following pharmacologic activation or genetic overexpression. We hypothesized that adeno-associated virus (AAV)-mediated overexpression of SIRT1 in RGCs in a chronic ocular hypertension model can reduce RGC loss, thereby preserving visual function by sustained therapeutic effect. A control vector AAV-eGFP and therapeutic vector AAV-SIRT1 were constructed and optimized for transduction efficiency. A magnetic microbead mouse model of ocular hypertension was optimized to induce a time-dependent and chronic loss of visual function and RGC degeneration. Mice received intravitreal injection of control or therapeutic AAV in which a codon-optimized human SIRT1 expression is driven by a RGC selective promoter. Intraocular pressure (IOP) was measured, and visual function was examined by optokinetic response (OKR) weekly for 49 days following microbead injection. Visual function, RGC survival, and axon numbers were compared among control and therapeutic AAV-treated animals. AAV-eGFP and AAV-SIRT1 showed transduction efficiency of ~ 40%. AAV-SIRT1 maintains the transduction of SIRT1 over time and is selectively expressed in RGCs. Intravitreal injections of AAV-SIRT1 in a glaucoma model preserved visual function, increased RGC survival, and reduced axonal degeneration compared with the control construct. Over-expression of SIRT1 through AAV-mediated gene transduction indicates a RGC-selective component of neuroprotection in multiple models of acute optic nerve degeneration. Results here show a neuroprotective effect of RGC-selective gene therapy in a chronic glaucoma model characterized by sustained elevation of IOP and subsequent RGC loss. Results suggest that this strategy may be an effective therapeutic approach for treating glaucoma, and warrants evaluation for the treatment of other chronic neurodegenerative diseases.
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Affiliation(s)
- Jipeng Yue
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
| | - Reas S Khan
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thu T Duong
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly E Dine
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
| | - Qi N Cui
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
| | - Nuala O'Neill
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
| | - Puya Aravand
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tehui Liu
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Brahim Chaqour
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Kenneth S Shindler
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ahmara G Ross
- University of Pennsylvania/Ophthalmology, Philadelphia, PA, USA.
- Center for Advanced Retinal and Ocular Therapeutics, F. M. Kirby Center for Molecular Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Sanie-Jahromi F, Mahmoudi A, Khalili MR, Nowroozzadeh MH. A Review on the Application of Stem Cell Secretome in the Protection and Regeneration of Retinal Ganglion Cells; a Clinical Prospect in the Treatment of Optic Neuropathies. Curr Eye Res 2022; 47:1463-1471. [PMID: 35876610 DOI: 10.1080/02713683.2022.2103153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE Retinal ganglion cells (RGCs) are one the most specialized neural tissues in the body. They transmit (and further process) chemoelectrical information originating in outer retinal layers to the central nervous system. In fact, the optic nerve is composed of RGC axons. Like other neural cells, RGCs will not completely heal after the injury, leading to irreversible vision loss from disorders such as glaucoma that primarily affect these cells. Several methods have been developed to protect or regenerate RGCs during or after the insult has occurred. This study aims to review the most recent clinical, animal and laboratory experiments designed for the regeneration of RGC that apply the stem cell-derived secretome. METHODS We extracted the studies from Web of Science (ISI), Medline (PubMed), Scopus, Embase, and Google scholar from the first record to the last report registered in 2022, using the following keywords; "secretome" OR "conditioned medium" OR "exosome" OR "extracellular vesicle" AND "stem cell" AND "RGC" OR "optic neuropathy". Any registered clinical trials related to the subject were also extracted from clinicaltrial.gov. All published original studies that express the effect of stem cell secretome on RGC cells in optic neuropathy, whether in vitro, in animal studies, or in clinical trials were included in this survey. RESULTS In this review, we provided an update on the existing reports, and a brief description of the details applied in the procedure. Compared to cell transplant, applying stem cell-derived secretome has the advantage of minimized immunogenicity yet preserving efficacy via its rich content of growth factors. CONCLUSIONS Different sources of stem cell secretomes have distinct implications in the management of RGC injury, which is the main subject of the present article.
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Affiliation(s)
- Fatemeh Sanie-Jahromi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ahmad Mahmoudi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Reza Khalili
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - M Hossein Nowroozzadeh
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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5
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Jeng BH, Hamrah P, Kirshner ZZ, Mendez BC, Wessel HC, Brown LR, Steed DL. Exploratory Phase II Multicenter, Open-Label, Clinical Trial of ST266, a Novel Secretome for Treatment of Persistent Corneal Epithelial Defects. Transl Vis Sci Technol 2022; 11:8. [PMID: 34994777 PMCID: PMC8742509 DOI: 10.1167/tvst.11.1.8] [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] [Indexed: 01/14/2023] Open
Abstract
Objective An exploratory phase II, multicenter, open-label, clinical trial (NCT03687632) was conducted to evaluate the safety and effectiveness in treating persistent corneal epithelial defects (PEDs) with ST266, a proprietary novel multi-cytokine platform biologic solution secreted by cultured Amnion-derived Multipotent Progenitor (AMP) cells. Methods Subjects with a PED were treated with ST266 eye drops 4 times daily for 28 days, then followed for 1 week. Safety was assessed by monitoring of adverse events (AEs) and serious adverse events (SAEs). Efficacy was assessed by measuring the area of the PED by slit lamp biomicroscopy. Tolerability of ST266, percentage of eyes with complete healing, reduction in area of the epithelial defect, and maintenance of a reduction in the area of the epithelial defect 7 days after treatment were recorded. Results Thirteen patients were enrolled into the trial at one of eight sites. The first patient withdrew after 5 days. The remaining 12 patients with PEDs with median duration of 39 days (range = 12 to 393 days) completed treatment. Ten of the 12 eyes had been refractory to treatment with various conventional therapies prior to enrollment. After 28 days of treatment, there was a significant decrease in mean PED area compared with baseline (66.4% ± 35.3%, P = 0.001). At follow-up, 1 week after completion of treatment, on day 35, the PED area was further reduced by 78.8% ± 37.5% (P = 0.01) compared with baseline. During 28 days of treatment, 5 eyes (41.7%) had complete wound closure. There were no AEs of concern thought to be related to the drug, and no SAEs were noted. Conclusions In this trial, we found ST266 eye drops might promote corneal epithelization, thereby reducing the PED area, including in refractory cases in a wide range of etiologies. ST266 was well-tolerated by most patients.
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Affiliation(s)
- Bennie H Jeng
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Pedram Hamrah
- Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Ziv Z Kirshner
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, USA
| | | | - Howard C Wessel
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, USA
| | - Larry R Brown
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, USA
| | - David L Steed
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, USA
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6
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Aneesh A, Liu A, Moss HE, Feinstein D, Ravindran S, Mathew B, Roth S. Emerging concepts in the treatment of optic neuritis: mesenchymal stem cell-derived extracellular vesicles. Stem Cell Res Ther 2021; 12:594. [PMID: 34863294 PMCID: PMC8642862 DOI: 10.1186/s13287-021-02645-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/31/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Optic neuritis (ON) is frequently encountered in multiple sclerosis, neuromyelitis optica spectrum disorder, anti-myelin oligodendrocyte glycoprotein associated disease, and other systemic autoimmune disorders. The hallmarks are an abnormal optic nerve and inflammatory demyelination; episodes of optic neuritis tend to be recurrent, and particularly for neuromyelitis optica spectrum disorder, may result in permanent vision loss. MAIN BODY Mesenchymal stem cell (MSC) therapy is a promising approach that results in remyelination, neuroprotection of axons, and has demonstrated success in clinical studies in other neuro-degenerative diseases and in animal models of ON. However, cell transplantation has significant disadvantages and complications. Cell-free approaches utilizing extracellular vesicles (EVs) produced by MSCs exhibit anti-inflammatory and neuroprotective effects in multiple animal models of neuro-degenerative diseases and in rodent models of multiple sclerosis (MS). EVs have potential to be an effective cell-free therapy in optic neuritis because of their anti-inflammatory and remyelination stimulating properties, ability to cross the blood brain barrier, and ability to be safely administered without immunosuppression. CONCLUSION We review the potential application of MSC EVs as an emerging treatment strategy for optic neuritis by reviewing studies in multiple sclerosis and related disorders, and in neurodegeneration, and discuss the challenges and potential rewards of clinical translation of EVs including cell targeting, carrying of therapeutic microRNAs, and prolonging delivery for treatment of optic neuritis.
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Affiliation(s)
- Anagha Aneesh
- Department of Anesthesiology, College of Medicine, University of Illinois, 835 South Wolcott Avenue, Room E714, Chicago, IL, 60612, USA
| | - Alice Liu
- Department of Anesthesiology, College of Medicine, University of Illinois, 835 South Wolcott Avenue, Room E714, Chicago, IL, 60612, USA
| | - Heather E Moss
- Departments of Ophthalmology and Neurology & Neurological Sciences, Stanford University, Palo Alto, CA, USA
| | - Douglas Feinstein
- Department of Anesthesiology, College of Medicine, University of Illinois, 835 South Wolcott Avenue, Room E714, Chicago, IL, 60612, USA
| | - Sriram Ravindran
- Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Biji Mathew
- Department of Anesthesiology, College of Medicine, University of Illinois, 835 South Wolcott Avenue, Room E714, Chicago, IL, 60612, USA.
| | - Steven Roth
- Department of Anesthesiology, College of Medicine, University of Illinois, 835 South Wolcott Avenue, Room E714, Chicago, IL, 60612, USA.
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Sarkar P, Mehtani A, Gandhi HC, Dubey V, Tembhurde PM, Gupta MK. Atypical optic neuritis: An overview. Indian J Ophthalmol 2021; 69:27-35. [PMID: 33323567 PMCID: PMC7926095 DOI: 10.4103/ijo.ijo_451_20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Optic neuritis (ON) refers to conditions that involve inflammation of the optic nerve. Various autoantibodies have been found, which are associated with central nervous system inflammatory disorders and have provided much information about the immune targets and mechanisms that impact the prognosis, treatment, and recurrence of atypical ON. Therefore, neurologists and ophthalmologists together should work to find out clinical, laboratory, and imaging findings that may provide important clues to the etiology of atypical ON and its management. Various biomarkers have been identified to confirm and distinguish atypical optic neuritis from others. The purpose of this review is to present the current scenario of atypical ON and its clinical management.
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Affiliation(s)
- Prathama Sarkar
- Department of Ophthalmology, Deen Dayal Upadhyay Hospital, New Delhi, India
| | - Amit Mehtani
- Department of Ophthalmology, Deen Dayal Upadhyay Hospital, New Delhi, India
| | - H C Gandhi
- Department of Ophthalmology, Deen Dayal Upadhyay Hospital, New Delhi, India
| | - Vinita Dubey
- Department of Ophthalmology, Deen Dayal Upadhyay Hospital, New Delhi, India
| | | | - Mohit Kumar Gupta
- Department of Ophthalmology, Deen Dayal Upadhyay Hospital, New Delhi, India
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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.
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Hasturk H, Steed D, Tosun E, Martins M, Floros C, Nguyen D, Stephens D, Cugini M, Starr J, Van Dyke TE. Use of amnion-derived cellular cytokine solution for the treatment of gingivitis: A 2-week safety, dose-ranging, proof-of-principle randomized trial. J Periodontol 2021; 92:1317-1328. [PMID: 33586783 PMCID: PMC8518950 DOI: 10.1002/jper.20-0800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 11/13/2022]
Abstract
Background A 6‐week Phase I clinical trial was performed to primarily evaluate the safety and secondarily determine the preliminary efficacy of a novel biological solution, ST266, comprised of a mixture of cytokines, growth factors, nucleic acids, and lipids secreted by cultured amnion‐derived multipotent progenitor cells on gingival inflammation. Methods Fifty‐four adults with gingivitis/periodontitis were randomly assigned to 1X ST266 or diluted 0.3X ST266 or saline topically applied on facial/lingual gingiva (20 µL/tooth). Safety was assessed through oral soft/hard tissue exam, adverse events, and routine laboratory tests. Efficacy was assessed by modified gingival index (MGI), bleeding on probing, plaque index, probing depth (PD), and clinical attachment level (CAL). Assessments were performed on day 0, 8, 12, and 42. ST266 and saline applied daily starting at day 0 through day 12 except weekend days. Plasma was analyzed for safety and proinflammatory cytokines, interleukin (IL)‐1β, IL‐6, tumor necrosis factor‐alpha, and interferon gamma. Gingival crevicular fluid (GCF) was analyzed for the same cytokines. Subgingival plaque was primarily analyzed by checkerboard DNA‐DNA hybridization. Comparisons with saline were modeled through a generalized estimating equations method adjusting for baseline. Results No safety concern was found related to ST266. Statistically significant reduction in MGI was noted at day 42 by 1X ST266 compared with saline (P = 0.044). PD and CAL were reduced by both doses of ST266 at day 42 (P <0.01) and by 1X ST266 at day 12 (P <0.05). GCF IL‐1β and IL‐6 levels were reduced by both doses of ST266 at day 12 (P <0.05, P <0.01, respectively). IL‐6 was also significantly reduced in plasma of both ST266 groups (P <0.05). Significant reductions in red complex bacteria were detected in both ST266 doses. Conclusions In this “first in human oral cavity” study, topical ST266 was safe and effective in reducing gingival inflammation in 6 weeks. Longitudinal studies with large sample sizes are warranted to assess the therapeutic value of this novel host modulatory compound in the treatment of periodontal diseases.
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Affiliation(s)
- Hatice Hasturk
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | | | - Emre Tosun
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Melissa Martins
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Constantinos Floros
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Daniel Nguyen
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Danielle Stephens
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Maryann Cugini
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
| | - Jacqueline Starr
- Brigham and Women's Hospital, Channing Division of Network Medicine, Boston, MA
| | - Thomas E Van Dyke
- The Forsyth Institute, Center for Clinical and Translational Research, Cambridge, MA
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10
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Rescue of retinal ganglion cells in optic nerve injury using cell-selective AAV mediated delivery of SIRT1. Gene Ther 2021; 28:256-264. [PMID: 33589779 PMCID: PMC8149296 DOI: 10.1038/s41434-021-00219-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 12/07/2020] [Accepted: 01/15/2021] [Indexed: 11/25/2022]
Abstract
SIRT1 prevents retinal ganglion cell (RGC) loss in models of optic neuropathy following pharmacologic activation or genetic overexpression. The exact mechanism of loss is not known, prior evidence suggests this is through oxidative stress to either neighboring cells or RGC specifically. We investigated the neuroprotective potential of RGC-selective SIRT1 gene therapy in the optic nerve crush (ONC) model. We hypothesized that AAV-mediated overexpression of SIRT1 in RGCs reduces RGC loss, thereby preserving visual function. Cohorts of C57Bl/6J mice received intravitreal injection of experimental or control AAVs using either a ganglion cell promoter or a constitutive promoter and ONC was performed. Visual function was examined by optokinetic response (OKR) for 7 days following ONC. Retina and optic nerves were harvested to investigate RGC survival by immunolabeling. The AAV7m8-SNCG.SIRT1 vector showed 44% transduction efficiency for RGCs compared with 25% (P > 0.05) by AAV2-CAG.SIRT1, and AAV7m8-SNCG.SIRT1 drives expression selectively in RGCs in vivo. Animals modeling ONC demonstrated reduced visual acuity compared to controls. Intravitreal delivery of AAV7m8-SNCG.SIRT1 mediated significant preservation of the OKR and RGC survival compared to AAV7m8-SNCG.eGFP controls, an effect not seen with the AAV2 vector. RGC-selective expression of SIRT1 offers a targeted therapy for an animal model with significant ganglion cell loss. Over-expression of SIRT1 through AAV-mediated gene transduction suggests a RGC selective component of neuro-protection using the ONC model. This study expands our understanding of SIRT1 mediated neuroprotection in the context of compressive or traumatic optic neuropathy, making it a strong therapeutic candidate for testing in all optic neuropathies.
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Willett K, Khan RS, Dine K, Wessel H, Kirshner ZZ, Sauer JL, Ellis A, Brown LR, Shindler KS. Neuroprotection mediated by ST266 requires full complement of proteins secreted by amnion-derived multipotent progenitor cells. PLoS One 2021; 16:e0243862. [PMID: 33406093 PMCID: PMC7787369 DOI: 10.1371/journal.pone.0243862] [Citation(s) in RCA: 4] [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: 04/08/2020] [Accepted: 11/27/2020] [Indexed: 11/23/2022] Open
Abstract
ST266 is the biological secretome of cultured Amnion-derived Multipotent Progenitor cells containing multiple growth factors and cytokines. While intranasally-administered ST266 improves the phenotype in experimental optic neuritis, specific ST266 components mediating these effects are not known. We compared the effects of ST266 with and without removal of large molecular weight proteins both in vitro and in the multiple sclerosis model experimental autoimmune encephalomyelitis (EAE) in C57BL/6J mice. Mice were treated daily with intranasal vehicle, ST266 or lower molecular weight fraction of ST266. Retinal ganglion cells were counted in isolated retinas, and optic nerves were assessed for inflammation and demyelination. ST266 treatment significantly improved retinal ganglion cell survival and reduced optic nerve demyelination in EAE mice. The lower molecular weight ST266 fraction significantly improved optic nerve demyelination, but only showed a trend towards improved retinal ganglion cell survival. ST266 fractions below 50kDa increased Schwann cell proliferation in vitro, but were less effective than non-fractionated ST266. Demyelination attenuation was partially associated with the lower molecular weight ST266 fraction, but removal of higher molecular weight biomolecules from ST266 diminishes its neuroprotective effects, suggesting at least some high molecular weight proteins play a role in ST266-mediated neuroprotection.
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Affiliation(s)
- Keirnan Willett
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Reas S. Khan
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kimberly Dine
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Howard Wessel
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Ziv Z. Kirshner
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Jodie L. Sauer
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Ashley Ellis
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Larry R. Brown
- Noveome Biotherapeutics, Inc., Pittsburgh, Pennsylvania, United States of America
| | - Kenneth S. Shindler
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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12
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Miller PE, Eaton JS. Medical anti-glaucoma therapy: Beyond the drop. Vet Ophthalmol 2020; 24 Suppl 1:2-15. [PMID: 33164328 DOI: 10.1111/vop.12843] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/30/2020] [Accepted: 10/20/2020] [Indexed: 12/25/2022]
Abstract
Barriers to effective medical therapy are numerous and include difficulties with effective and sustained control of intraocular pressure (IOP) and adherence to prescribed anti-glaucoma drop regimens. In an effort to circumvent these challenges, a number of new anti-glaucoma therapies with sustained effects have emerged. Methods for sustained delivery of prostaglandin analogs are being intensely investigated and many are in human clinical trials. Intracameral devices include the following: Allergan's Durysta™ Bimatoprost SR, Envisia Therapeutics' ENV515 travoprost implant, Glaukos' iDose™ , Ocular Therapeutix's OTX-TIC travoprost implant, and Santen's polycaprolactone implant with PGE2-derivative DE-117. Other prostaglandin-based technologies include Allergan's bimatoprost ring (placed in the conjunctival fornix), Ocular Therapeutics' OTX-TP intracanalicular travoprost implant, subconjunctival latanoprost in a liposomal formulation, and the PGE2 derivative PGN 9856-isopropyl ester that is applied to the periorbital skin. Exciting breakthroughs in gene therapy include using viral vectors to correct defective genes such as MYOC or to modulate gonioimplant fibrosis, CRISPR technology to edit MYOC or to alter aquaporin to reduce aqueous humor production, and siRNA technology to silence specific genes. Stem cell technology can repopulate depleted tissues or, in the case of Neurotech's Renexus® NT-501 intravitreal implant, serve as a living drug delivery device that continuously secretes neurotrophic factors. Other unique approaches involve nanotechnology, nasal sprays that deliver drug directly to the optic nerve and noninvasive alternating current stimulation of surviving cells in the optic nerve. Over time these modalities are likely to challenge the preeminent role that drops currently play in the medical treatment of glaucoma in animals.
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Affiliation(s)
- Paul E Miller
- School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Joshua Seth Eaton
- School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
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13
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Farfán N, Carril J, Redel M, Zamorano M, Araya M, Monzón E, Alvarado R, Contreras N, Tapia-Bustos A, Quintanilla ME, Ezquer F, Valdés JL, Israel Y, Herrera-Marschitz M, Morales P. Intranasal Administration of Mesenchymal Stem Cell Secretome Reduces Hippocampal Oxidative Stress, Neuroinflammation and Cell Death, Improving the Behavioral Outcome Following Perinatal Asphyxia. Int J Mol Sci 2020; 21:ijms21207800. [PMID: 33096871 PMCID: PMC7589575 DOI: 10.3390/ijms21207800] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/11/2020] [Accepted: 10/14/2020] [Indexed: 12/11/2022] Open
Abstract
Perinatal Asphyxia (PA) is a leading cause of motor and neuropsychiatric disability associated with sustained oxidative stress, neuroinflammation, and cell death, affecting brain development. Based on a rat model of global PA, we investigated the neuroprotective effect of intranasally administered secretome, derived from human adipose mesenchymal stem cells (MSC-S), preconditioned with either deferoxamine (an hypoxia-mimetic) or TNF-α+IFN-γ (pro-inflammatory cytokines). PA was generated by immersing fetus-containing uterine horns in a water bath at 37 °C for 21 min. Thereafter, 16 μL of MSC-S (containing 6 μg of protein derived from 2 × 105 preconditioned-MSC), or vehicle, were intranasally administered 2 h after birth to asphyxia-exposed and control rats, evaluated at postnatal day (P) 7. Alternatively, pups received a dose of either preconditioned MSC-S or vehicle, both at 2 h and P7, and were evaluated at P14, P30, and P60. The preconditioned MSC-S treatment (i) reversed asphyxia-induced oxidative stress in the hippocampus (oxidized/reduced glutathione); (ii) increased antioxidative Nuclear Erythroid 2-Related Factor 2 (NRF2) translocation; (iii) increased NQO1 antioxidant protein; (iv) reduced neuroinflammation (decreasing nuclearNF-κB/p65 levels and microglial reactivity); (v) decreased cleaved-caspase-3 cell-death; (vi) improved righting reflex, negative geotaxis, cliff aversion, locomotor activity, anxiety, motor coordination, and recognition memory. Overall, the study demonstrates that intranasal administration of preconditioned MSC-S is a novel therapeutic strategy that prevents the long-term effects of perinatal asphyxia.
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Affiliation(s)
- Nancy Farfán
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Jaime Carril
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Martina Redel
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Marta Zamorano
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Maureen Araya
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Estephania Monzón
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Raúl Alvarado
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Norton Contreras
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago 8380453, Chile; (N.C.); (J.L.V.)
| | - Andrea Tapia-Bustos
- School of Pharmacy, Faculty of Medicine, Universidad Andres Bello, Santiago 8370149, Chile;
| | - María Elena Quintanilla
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Fernando Ezquer
- Center for Regenerative Medicine, Faculty of Medicine-Clínica Alemana, Universidad del Desarrollo, Santiago 7710162, Chile;
| | - José Luis Valdés
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago 8380453, Chile; (N.C.); (J.L.V.)
| | - Yedy Israel
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Mario Herrera-Marschitz
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
| | - Paola Morales
- Molecular & Clinical Pharmacology Program, ICBM, Faculty of Medicine University of Chile, Santiago 8380453, Chile; (N.F.); (J.C.); (M.R.); (M.Z.); (M.A.); (E.M.); (R.A.); (M.E.Q.); (Y.I.); (M.H.-M.)
- Department of Neuroscience, Faculty of Medicine, University of Chile, Santiago 8380453, Chile; (N.C.); (J.L.V.)
- Correspondence: ; Tel.: +56-229786788
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14
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Gramlich OW, Brown AJ, Godwin CR, Chimenti MS, Boland LK, Ankrum JA, Kardon RH. Systemic Mesenchymal Stem Cell Treatment Mitigates Structural and Functional Retinal Ganglion Cell Degeneration in a Mouse Model of Multiple Sclerosis. Transl Vis Sci Technol 2020; 9:16. [PMID: 32855863 PMCID: PMC7422913 DOI: 10.1167/tvst.9.8.16] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/26/2020] [Indexed: 01/14/2023] Open
Abstract
Purpose The purpose of this study was to determine mesenchymal stem cell (MSC) therapy efficacy on rescuing the visual system in the experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS) and to provide new mechanistic insights. Methods EAE was induced in female C57BL6 mice by immunization with myelin oligodendrocyte glycoprotein (MOG)35–55, complete Freund's adjuvant, and pertussis toxin. The findings were compared to sham-immunized mice. Half of the EAE mice received intraperitoneally delivered stem cells (EAE + MSC). Clinical progression was monitored according to a five-point EAE scoring scheme. Pattern electroretinogram (PERG) and retinal nerve fiber layer (RNFL) thickness were measured 32 days after induction. Retinas were harvested to determine retinal ganglion cell (RGC) density and prepared for RNA-sequencing. Results EAE animals that received MSC treatment seven days after EAE induction showed significantly lower motor-sensory impairment, improvement in the PERG amplitude, and preserved RNFL. Analysis of RNA-sequencing data demonstrated statistically significant differences in gene expression in the retina of MSC-treated EAE mice. Differentially expressed genes were enriched for pathways involved in endoplasmic reticulum stress, endothelial cell differentiation, HIF-1 signaling, and cholesterol transport in the MSC-treated EAE group. Conclusions Systemic MSC treatment positively affects RGC function and survival in EAE mice. Better cholesterol handling by increased expression of Abca1, the cholesterol efflux regulatory protein, paired with the resolution of HIF-1 signaling activation might explain the improvements seen in PERG of EAE animals after MSC treatment. Translational Relevance Using MSC therapy in a mouse model of MS, we discovered previously unappreciated biochemical pathways associated with RGC neuroprotection, which have the potential to be pharmacologically targeted as a new treatment regimen.
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Affiliation(s)
- Oliver W Gramlich
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, USA
| | - Alexander J Brown
- Department of Biomedical Research, National Jewish Health, Denver, CO, USA.,Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Cheyanne R Godwin
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, USA
| | - Michael S Chimenti
- Iowa Institute of Human Genetics, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Lauren K Boland
- Roy J. Carver Department of Biomedical Engineering College, The University of Iowa, Iowa City, IA, USA
| | - James A Ankrum
- Roy J. Carver Department of Biomedical Engineering College, The University of Iowa, Iowa City, IA, USA
| | - Randy H Kardon
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, USA
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15
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Targeted Krüppel-Like Factor 4 Gene Knock-Out in Retinal Ganglion Cells Improves Visual Function in Multiple Sclerosis Mouse Model. eNeuro 2020; 7:ENEURO.0320-19.2020. [PMID: 32165410 PMCID: PMC7139550 DOI: 10.1523/eneuro.0320-19.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 02/12/2020] [Accepted: 02/20/2020] [Indexed: 12/26/2022] Open
Abstract
Axonal demyelination injury and neuronal degeneration are the primary causes of visual disability in multiple sclerosis (MS)-linked optic neuritis patients. Immunomodulatory therapies targeting inflammation have failed to avert the disease progression and no therapies exist to prevent the neuronal deficits seen in MS to date. Neuroprotective strategies targeting oligodendrocytes and astroglia have shown limited success due to a lack of axonal regeneration from injured neurons. In this study, we used the chronic experimental autoimmune encephalomyelitis (EAE) mouse model of MS to investigate the axonal regenerative approach to improve the neuronal function. Our approach focused on targeted knock-out (KO) of the developmentally regulated axon growth inhibitory Krüppel-like factor 4 (Klf4) gene in retinal ganglion cells (RGCs) of Klf4fl/flmice by intravitreal delivery of AAV2-Cre-ires-EGFP recombinant virus (1) at the time of EAE sensitization and (2) after the onset of optic neuritis-mediated visual defects in the mice. Klf4 gene KO performed simultaneous with EAE sensitization prevented the visual loss as assessed by pattern electroretinograms (PERGs) in the mice and protected the RGCs from EAE-mediated death. More importantly, however, Klf4 gene KO after the onset of optic neuritis also resulted in RGC neuroprotection with additional restoration of their function, thereby improving the visual function outcomes in the EAE model. This study establishes the efficacy of Klf4 targeted knock-down in EAE even after the onset of disease symptoms, and thus should be further explored as a potential treatment strategy for MS/optic neuritis patients.
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