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Bou Ghanem GO, Wareham LK, Calkins DJ. Addressing neurodegeneration in glaucoma: Mechanisms, challenges, and treatments. Prog Retin Eye Res 2024; 100:101261. [PMID: 38527623 DOI: 10.1016/j.preteyeres.2024.101261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/15/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
Glaucoma is the leading cause of irreversible blindness globally. The disease causes vision loss due to neurodegeneration of the retinal ganglion cell (RGC) projection to the brain through the optic nerve. Glaucoma is associated with sensitivity to intraocular pressure (IOP). Thus, mainstay treatments seek to manage IOP, though many patients continue to lose vision. To address neurodegeneration directly, numerous preclinical studies seek to develop protective or reparative therapies that act independently of IOP. These include growth factors, compounds targeting metabolism, anti-inflammatory and antioxidant agents, and neuromodulators. Despite success in experimental models, many of these approaches fail to translate into clinical benefits. Several factors contribute to this challenge. Firstly, the anatomic structure of the optic nerve head differs between rodents, nonhuman primates, and humans. Additionally, animal models do not replicate the complex glaucoma pathophysiology in humans. Therefore, to enhance the success of translating these findings, we propose two approaches. First, thorough evaluation of experimental targets in multiple animal models, including nonhuman primates, should precede clinical trials. Second, we advocate for combination therapy, which involves using multiple agents simultaneously, especially in the early and potentially reversible stages of the disease. These strategies aim to increase the chances of successful neuroprotective treatment for glaucoma.
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Affiliation(s)
- Ghazi O Bou Ghanem
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Lauren K Wareham
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - David J Calkins
- Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
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2
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Lucchesi M, Marracci S, Amato R, Lapi D, Santana-Garrido Á, Espinosa-Martín P, Vázquez CM, Mate A, Dal Monte M. The Anti-Inflammatory and Antioxidant Properties of Acebuche Oil Exert a Retinoprotective Effect in a Murine Model of High-Tension Glaucoma. Nutrients 2024; 16:409. [PMID: 38337691 PMCID: PMC10857689 DOI: 10.3390/nu16030409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/27/2024] [Accepted: 01/29/2024] [Indexed: 02/12/2024] Open
Abstract
Glaucoma is characterized by cupping of the optic disc, apoptotic degeneration of retinal ganglion cells (RGCs) and their axons, and thinning of the retinal nerve fiber layer, with patchy loss of vision. Elevated intraocular pressure (IOP) is a major risk factor for hypertensive glaucoma and the only modifiable one. There is a need to find novel compounds that counteract other risk factors contributing to RGC degeneration. The oil derived from the wild olive tree (Olea europaea var. sylvestris), also called Acebuche (ACE), shows powerful anti-inflammatory, antioxidant and retinoprotective effects. We evaluated whether ACE oil could counteract glaucoma-related detrimental effects. To this aim, we fed mice either a regular or an ACE oil-enriched diet and then induced IOP elevation through intraocular injection of methylcellulose. An ACE oil-enriched diet suppressed glaucoma-dependent retinal glia reactivity and inflammation. The redox status of the glaucomatous retinas was restored to a control-like situation, and ischemia was alleviated by an ACE oil-enriched diet. Notably, retinal apoptosis was suppressed in the glaucomatous animals fed ACE oil. Furthermore, as shown by electroretinogram analyses, RGC electrophysiological functions were almost completely preserved by the ACE oil-enriched diet. These ameliorative effects were IOP-independent and might depend on ACE oil's peculiar composition. Although additional studies are needed, nutritional supplementation with ACE oil might represent an adjuvant in the management of glaucoma.
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Affiliation(s)
- Martina Lucchesi
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (D.L.)
| | - Silvia Marracci
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (D.L.)
| | - Rosario Amato
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (D.L.)
| | - Dominga Lapi
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (D.L.)
| | - Álvaro Santana-Garrido
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain; (Á.S.-G.); (P.E.-M.); (C.M.V.)
- Epidemiología Clínica y Riesgo Cardiovascular, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Pablo Espinosa-Martín
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain; (Á.S.-G.); (P.E.-M.); (C.M.V.)
| | - Carmen María Vázquez
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain; (Á.S.-G.); (P.E.-M.); (C.M.V.)
- Epidemiología Clínica y Riesgo Cardiovascular, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Alfonso Mate
- Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain; (Á.S.-G.); (P.E.-M.); (C.M.V.)
- Epidemiología Clínica y Riesgo Cardiovascular, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, 56127 Pisa, Italy; (M.L.); (S.M.); (R.A.); (D.L.)
- Interdepartmental Research Center Nutrafood “Nutraceuticals and Food for Health”, University of Pisa, 56124 Pisa, Italy
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Wardman JH, Andreassen SN, Toft-Bertelsen TL, Jensen MN, Wilhjelm JE, Styrishave B, Hamann S, Heegaard S, Sinclair AJ, MacAulay N. CSF hyperdynamics in rats mimicking the obesity and androgen excess characteristic of patients with idiopathic intracranial hypertension. Fluids Barriers CNS 2024; 21:10. [PMID: 38273331 PMCID: PMC10810013 DOI: 10.1186/s12987-024-00511-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/05/2024] [Indexed: 01/27/2024] Open
Abstract
BACKGROUND Idiopathic intracranial hypertension (IIH) is a syndrome exhibiting elevated intracranial pressure (ICP), visual disturbances, and severe headache. IIH primarily affects young obese women, though it can occur in individuals of any age, BMI, and sex. IIH is characterized by systemic metabolic dysregulation with a profile of increased androgen hormones. However, the contribution of obesity/hormonal perturbations to cerebrospinal fluid (CSF) dynamics remains unresolved. METHODS We employed obese female Zucker rats and adjuvant testosterone to reveal IIH causal drivers. ICP and CSF dynamics were determined with in vivo experimentation and magnetic resonance imaging, testosterone levels assessed with mass spectrometry, and choroid plexus function revealed with transcriptomics. RESULTS Obese rats had undisturbed CSF testosterone levels and no changes in ICP or CSF dynamics. Adjuvant testosterone treatment of obese rats elevated the CSF secretion rate, although with no effect on the ICP, due to elevated CSF drainage capacity of these rats. CONCLUSIONS Obesity in itself therefore does not suffice to recapitulate the IIH symptoms in rats, but modulation of CSF dynamics appears with adjuvant testosterone treatment, which mimics the androgen excess observed in female IIH patients. Obesity-induced androgen dysregulation may thus contribute to the disease mechanism of IIH and could potentially serve as a future therapeutic target.
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Affiliation(s)
- Jonathan H Wardman
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Copenhagen, DK-2200, Denmark
| | - Søren Norge Andreassen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Copenhagen, DK-2200, Denmark
| | - Trine L Toft-Bertelsen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Copenhagen, DK-2200, Denmark
| | - Mette Nyholm Jensen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Copenhagen, DK-2200, Denmark
| | - Jens E Wilhjelm
- Department of Neurophysiology, Rigshospitalet, Copenhagen, Denmark
- Department of Health Technology, Technical University of Denmark, Copenhagen, Denmark
| | - Bjarne Styrishave
- Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Heegaard
- Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Alexandra J Sinclair
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Nanna MacAulay
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3, Copenhagen, DK-2200, Denmark.
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Wang X, Delle C, Peng W, Plá V, Giannetto M, Kusk P, Sigurdsson B, Sakurai S, Sweeney A, Sun Q, Du T, Libby RT, Nedergaard M. Age- and glaucoma-induced changes to the ocular glymphatic system. Neurobiol Dis 2023; 188:106322. [PMID: 37832797 DOI: 10.1016/j.nbd.2023.106322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 10/15/2023] Open
Abstract
The ocular glymphatic system supports bidirectional fluid transport along the optic nerve, thereby removes metabolic wastes including amyloid-β. To better understand this biological process, we examined the distributions of intravitreally and intracisternally infused tracers in full-length optic nerves from different age groups of mice. Aging was linked to globally impaired ocular glymphatic fluid transport, similar to what has seen previously in the brain. Aging also reduced the pupillary responsiveness to light stimulation and abolished light-induced facilitation in anterograde ocular glymphatic flow. In contrast to normal aging, in the DBA/2 J model of glaucoma, we found a pathological increase of glymphatic fluid transport to the anterior optic nerve that was associated with dilation of the perivascular spaces. Thus, aging and glaucoma have fundamentally different effects on ocular glymphatic fluid transport. Manipulation of glymphatic fluid transport might therefore present a new target for the treatment of glaucoma.
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Affiliation(s)
- Xiaowei Wang
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark; Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA.
| | - Christine Delle
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Weiguo Peng
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark; Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Virginia Plá
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Michael Giannetto
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA; Neuroscience Graduate Program, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Peter Kusk
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Björn Sigurdsson
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Shinya Sakurai
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Amanda Sweeney
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Qian Sun
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Ting Du
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Richard T Libby
- Department of Ophthalmology, University of Rochester Medical Center, Elmwood Avenue 601, Rochester, NY 14642, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark; Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, Rochester, NY 14642, USA.
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Amato R, Cammalleri M, Melecchi A, Bagnoli P, Porciatti V. Natural History of Glaucoma Progression in the DBA/2J Model: Early Contribution of Müller Cell Gliosis. Cells 2023; 12:cells12091272. [PMID: 37174673 PMCID: PMC10177096 DOI: 10.3390/cells12091272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Glaucoma is a chronic optic neuropathy characterized by progressive degeneration of retinal ganglion cells (RGCs). Elevated intraocular pressure (IOP) and the resulting mechanical stress are classically considered the main causes of RGC death. However, RGC degeneration and ensuing vision loss often occur independent of IOP, indicating a multifactorial nature of glaucoma, with the likely contribution of glial and vascular function. The aim of the present study was to provide a comprehensive evaluation of the time course of neuro-glial-vascular changes associated with glaucoma progression. We used DBA/2J mice in the age range of 2-15 months as a spontaneous model of glaucoma with progressive IOP elevation and RGC loss typical of human open-angle glaucoma. We found that the onset of RGC degeneration at 10 months of age coincided with that of IOP elevation and vascular changes such as decreased density, increased lacunarity and decreased tight-junction protein zonula occludens (ZO)-1, while hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) were already significantly upregulated at 6 months of age together with the onset of Müller cell gliosis. Astrocytes, however, underwent significant gliosis at 10 months. These results indicate that Müller cell activation occurs well before IOP elevation, with probable inflammatory consequences, and represents an early event in the glaucomatous process. Early upregulation of HIF-1α and VEGF is likely to contribute to blood retinal barrier failure, facilitating RGC loss. The different time courses of neuro-glial-vascular changes during glaucoma progression provide further insight into the nature of the disease and suggest potential targets for the development of efficient therapeutic intervention aside from IOP lowering.
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Affiliation(s)
- Rosario Amato
- Department of Biology, University of Pisa, 56127 Pisa, Italy
| | | | | | - Paola Bagnoli
- Department of Biology, University of Pisa, 56127 Pisa, Italy
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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Maestroni S, Belvedere A, Viganò I, Meoni C, Di Matteo F, Gabellini D, Bandello F, Pierro L, Zerbini G. Diabetes has no additional impact on retinal ganglion cell loss in a mouse model of spontaneous glaucoma. Eur J Ophthalmol 2022; 33:1418-1424. [PMID: 36523153 PMCID: PMC10152559 DOI: 10.1177/11206721221145980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Purpose There is no valid medical treatment for diabetic retinopathy mostly because its pathogenesis remains largely unknown. Early stages of diabetic retinopathy, just like glaucoma, are characterized by the loss of retinal ganglion cells. Whether the two diseases may share a similar pathogenic background is unknown. Methods To clarify this issue the thickness of retinal nerve fiber layer was studied in vivo by optical coherence tomography in 10 Ins2Akita (diabetic) and 10 C57BL/6J (control) mice. The number of retinal ganglion cells and retina's surface covered by neurofilaments were quantified ex vivo in 12 normoglycemic DBA/2J (glaucoma) and 11 diabetic (alloxan-induced) DBA/2J mice (glaucoma + diabetes). Results At 16 weeks of age retinal nerve fiber layer was significantly thinner in Ins2Akita mice confirming the neurodegenerative impact of diabetes. Number of retinal ganglion cells and retina's surface covered by neurofilaments were similar in normoglycemic and diabetic DBA/2J mice with the exception of the superior quadrant where the number of retinal ganglion cells was increased in animals with glaucoma + diabetes. Conclusions In presence of glaucoma, diabetes is unable to induce further retinal ganglion cells loss. The hypothesis that the mechanism leading to retinal ganglion cells loss may be shared by the two diseases cannot be ruled out. Whether early diabetes-driven retinal neurodegeneration could be prevented by neuroprotective treatment proven to be effective in case of glaucoma, remains to be clarified.
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Affiliation(s)
- Silvia Maestroni
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Arianna Belvedere
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Ilaria Viganò
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Cesare Meoni
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federico Di Matteo
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy
| | - Daniela Gabellini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy
| | - Luisa Pierro
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Vita-Salute University, Milan, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS San Raffaele Scientific Institute, Milan, Italy
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Mavilio A, Sisto D, Dammacco R, Durante G, Alessio G. Retrograde Optic Nerve Degeneration in Pituitary Adenoma: A Study with RE-PERG. Clin Ophthalmol 2022; 16:4135-4144. [DOI: 10.2147/opth.s384525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022] Open
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Rodrigo MJ, Bravo-Osuna I, Subias M, Montolío A, Cegoñino J, Martinez-Rincón T, Mendez-Martinez S, Aragón-Navas A, Garcia-Herranz D, Pablo LE, Herrero-Vanrell R, del Palomar AP, Garcia-Martin E. Tunable degrees of neurodegeneration in rats based on microsphere-induced models of chronic glaucoma. Sci Rep 2022; 12:20622. [PMID: 36450772 PMCID: PMC9712621 DOI: 10.1038/s41598-022-24954-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/22/2022] [Indexed: 12/12/2022] Open
Abstract
This study compares four different animal models of chronic glaucoma against normal aging over 6 months. Chronic glaucoma was induced in 138 Long-Evans rats and compared against 43 aged-matched healthy rats. Twenty-five rats received episcleral vein sclerosis injections (EPIm cohort) while the rest were injected in the eye anterior chamber with a suspension of biodegradable microspheres: 25 rats received non-loaded microspheres (N-L Ms cohort), 45 rats received microspheres loaded with dexamethasone (MsDexa cohort), and 43 rats received microspheres co-loaded with dexamethasone and fibronectin (MsDexaFibro cohort). Intraocular pressure, neuroretinal function, structure and vitreous interface were evaluated. Each model caused different trends in intraocular pressure, produced specific retinal damage and vitreous signals. The steepest and strongest increase in intraocular pressure was seen in the EPIm cohort and microspheres models were more progressive. The EPIm cohort presented the highest vitreous intensity and percentage loss in the ganglion cell layer, the MsDexa cohort presented the greatest loss in the retinal nerve fiber layer, and the MsDexaFibro cohort presented the greatest loss in total retinal thickness. Function decreased differently among cohorts. Using biodegradable microspheres models it is possible to generate tuned neurodegeneration. These results support the multifactorial nature of glaucoma based on several noxa.
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Affiliation(s)
- María Jesús Rodrigo
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain
| | - Irene Bravo-Osuna
- grid.4795.f0000 0001 2157 7667Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,Health Research Institute of the San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - Manuel Subias
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain
| | - Alberto Montolío
- grid.11205.370000 0001 2152 8769Biomaterials Group, Aragon Engineering Research Institute (I3a), University of Zaragoza, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| | - José Cegoñino
- grid.11205.370000 0001 2152 8769Biomaterials Group, Aragon Engineering Research Institute (I3a), University of Zaragoza, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| | - Teresa Martinez-Rincón
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain
| | - Silvia Mendez-Martinez
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain
| | - Alba Aragón-Navas
- grid.4795.f0000 0001 2157 7667Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,Health Research Institute of the San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - David Garcia-Herranz
- grid.4795.f0000 0001 2157 7667Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,Health Research Institute of the San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - Luis Emilio Pablo
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain
| | - Rocío Herrero-Vanrell
- grid.4795.f0000 0001 2157 7667Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal) Research Group UCM 920415, Department of Pharmaceutics and Food Technology, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,Health Research Institute of the San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - Amaya Pérez del Palomar
- grid.11205.370000 0001 2152 8769Biomaterials Group, Aragon Engineering Research Institute (I3a), University of Zaragoza, Zaragoza, Spain ,grid.11205.370000 0001 2152 8769Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain
| | - Elena Garcia-Martin
- grid.411106.30000 0000 9854 2756Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Spain ,grid.417198.20000 0000 8497 6529Thematic Research Network in Ophthalmology (Oftared), Carlos III National Institute of Health, Madrid, Spain ,grid.11205.370000 0001 2152 8769Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragón), University of Zaragoza, Zaragoza, Spain ,C/Padre Arrupe, Servicio de Oftalmología, Edificio de Consultas Externas, Planta 1, 50009 Zaragoza, Spain
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Van Hook MJ. Influences of Glaucoma on the Structure and Function of Synapses in the Visual System. Antioxid Redox Signal 2022; 37:842-861. [PMID: 35044228 PMCID: PMC9587776 DOI: 10.1089/ars.2021.0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/31/2021] [Indexed: 11/12/2022]
Abstract
Significance: Glaucoma is an age-related neurodegenerative disorder of the visual system associated with sensitivity to intraocular pressure (IOP). It is the leading irreversible cause of vision loss worldwide, and vision loss results from damage and dysfunction of the retinal output neurons known as retinal ganglion cells (RGCs). Recent Advances: Elevated IOP and optic nerve injury triggers pruning of RGC dendrites, altered morphology of excitatory inputs from presynaptic bipolar cells, and disrupted RGC synaptic function. Less is known about RGC outputs, although evidence to date indicates that glaucoma is associated with altered mitochondrial and synaptic structure and function in RGC-projection targets in the brain. These early functional changes likely contribute to vision loss and might be a window into early diagnosis and treatment. Critical Issues: Glaucoma affects different RGC populations to varying extents and along distinct time courses. The influence of glaucoma on RGC synaptic function as well as the mechanisms underlying these effects remain to be determined. Since RGCs are an especially energetically demanding population of neurons, altered intracellular axon transport of mitochondria and mitochondrial function might contribute to RGC synaptic dysfunction in the retina and brain as well as RGC vulnerability in glaucoma. Future Directions: The mechanisms underlying differential RGC vulnerability remain to be determined. Moreover, the timing and mechanisms of RGCs synaptic dysfunction and degeneration will provide valuable insight into the disease process in glaucoma. Future work will be able to capitalize on these findings to better design diagnostic and therapeutic approaches to detect disease and prevent vision loss. Antioxid. Redox Signal. 37, 842-861.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Science and Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Cellular & Integrative Physiology, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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10
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Westgate CSJ, Hagen SM, Israelsen IME, Hamann S, Jensen RH, Eftekhari S. The impact of obesity-related raised intracranial pressure in rodents. Sci Rep 2022; 12:9102. [PMID: 35650312 PMCID: PMC9160066 DOI: 10.1038/s41598-022-13181-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 05/06/2022] [Indexed: 12/31/2022] Open
Abstract
Elevated intracranial pressure (ICP) is observed in many brain disorders. Obesity has been linked to ICP pathogenesis in disorders such as idiopathic intracranial pressure (IIH). We investigated the effect of diet induced obesity (DIO) on ICP and clinically relevant sequelae. Rats were fed either a control or high fat diet. Following weight gain long term ICP, headache behavior, body composition and retinal outcome were examined. Post-hoc analysis of retinal histology and molecular analysis of choroid plexus and trigeminal ganglion (TG) were performed. DIO rats demonstrated raised ICP by 55% which correlated with the abdominal fat percentage and increased non-respiratory slow waves, suggestive of altered cerebral compliance. Concurrently, DIO rats demonstrated a specific cephalic cutaneous allodynia which negatively correlated with the abdominal fat percentage. This sensitivity was associated with increased expression of headache markers in TG. Additionally, DIO rats had increased retinal nerve fiber layer thickness in vivo associated with raised ICP with a subsequent post-hoc demonstration of neuroretinal degeneration. This study demonstrates for the first time that DIO leads to raised ICP and subsequent clinically relevant symptom development. This novel model of non-traumatic raised ICP could expand the knowledge regarding disorders with elevated ICP such as IIH.
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Affiliation(s)
- Connar Stanley James Westgate
- Department of Neurology, Danish Headache Center, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Copenhagen, Denmark
| | - Snorre Malm Hagen
- Department of Neurology, Danish Headache Center, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Copenhagen, Denmark
- Department of Ophthalmology, Rigshospitalet-Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Ida Marchen Egerod Israelsen
- Department of Neurology, Danish Headache Center, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Copenhagen, Denmark
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet-Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Rigmor Højland Jensen
- Department of Neurology, Danish Headache Center, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Copenhagen, Denmark
| | - Sajedeh Eftekhari
- Department of Neurology, Danish Headache Center, Glostrup Research Institute, Rigshospitalet-Glostrup, University of Copenhagen, Nordstjernevej 42, 2600, Copenhagen, Denmark.
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11
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Porciatti V, Chou TH. Using Noninvasive Electrophysiology to Determine Time Windows of Neuroprotection in Optic Neuropathies. Int J Mol Sci 2022; 23:5751. [PMID: 35628564 PMCID: PMC9145583 DOI: 10.3390/ijms23105751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 02/04/2023] Open
Abstract
The goal of neuroprotection in optic neuropathies is to prevent loss of retinal ganglion cells (RGCs) and spare their function. The ideal time window for initiating neuroprotective treatments should be the preclinical period at which RGCs start losing their functional integrity before dying. Noninvasive electrophysiological tests such as the Pattern Electroretinogram (PERG) can assess the ability of RGCs to generate electrical signals under a protracted degenerative process in both clinical conditions and experimental models, which may have both diagnostic and prognostic values and provide the rationale for early treatment. The PERG can be used to longitudinally monitor the acute and chronic effects of neuroprotective treatments. User-friendly versions of the PERG technology are now commercially available for both clinical and experimental use.
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12
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Frame G, Schuller A, Smith MA, Crish SD, Dengler-Crish CM. Alterations in Retinal Signaling Across Age and Sex in 3xTg Alzheimer’s Disease Mice. J Alzheimers Dis 2022; 88:471-492. [PMID: 35599482 PMCID: PMC9398084 DOI: 10.3233/jad-220016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Background: Visual disturbances often precede cognitive dysfunction in patients with Alzheimer’s disease (AD) and may coincide with early accumulation of amyloid-β (Aβ) protein in the retina. These findings have inspired critical research on in vivo ophthalmic Aβ imaging for disease biomarker detection but have not fully answered mechanistic questions on how retinal pathology affects visual signaling between the eye and brain. Objective: The goal of this study was to provide a functional and structural assessment of eye-brain communication between retinal ganglion cells (RGCs) and their primary projection target, the superior colliculus, in female and male 3xTg-AD mice across disease stages. Methods: Retinal electrophysiology, axonal transport, and immunofluorescence were used to determine RGC projection integrity, and retinal and collicular Aβ levels were assessed with advanced protein quantitation techniques. Results: 3xTg mice exhibited nuanced deficits in RGC electrical signaling, axonal transport, and synaptic integrity that exceeded normal age-related decrements in RGC function in age- and sex-matched healthy control mice. These deficits presented in sex-specific patterns among 3xTg mice, differing in the timing and severity of changes. Conclusion: These data support the premise that retinal Aβ is not just a benign biomarker in the eye, but may contribute to subtle, nuanced visual processing deficits. Such disruptions might enhance the biomarker potential of ocular amyloid and differentiate patients with incipient AD from patients experiencing normal age-related decrements in visual function.
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Affiliation(s)
- Gabrielle Frame
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
- Biomedical Sciences Graduate Program, Kent State University, Kent, OH, USA
| | - Adam Schuller
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Matthew A. Smith
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
- Rebecca D. Considine Research Institute, Akron Children’s Hospital, Akron, OH, USA
| | - Samuel D. Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
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13
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Muir ER, Chandra SB, Narayanan D, Zhang V, Zhang I, Jiang Z, Kiel JW, Duong TQ. Effects of chronic mild hyperoxia on retinal and choroidal blood flow and retinal function in the DBA/2J mouse model of glaucoma. PLoS One 2022; 17:e0266192. [PMID: 35333901 PMCID: PMC8956188 DOI: 10.1371/journal.pone.0266192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 03/15/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To test the hypothesis that mild chronic hyperoxia treatment would improve retinal function despite a progressive decline in ocular blood flow in the DBA/2J mouse model of glaucoma. Materials and methods DBA/2J mice were treated with chronic mild hyperoxia (30% O2) beginning at 4.5 months of age or were untreated by giving normal room air. Retinal and choroidal blood flow (RBF and ChBF, respectively) were measured at 4, 6, and 9 months of age by MRI. Blood flow was additionally measured under hypercapnia challenge (5% CO2 inhalation) to assess vascular reactivity. Intraocular pressure (IOP) was measured using a rebound tonometer at the same time points. Scotopic flash electroretinograms (ERGs) were recorded at 9 months of age. Results Both ChBF and RBF were reduced and significantly affected by age (p < 0.01), but neither were significantly affected by O2-treatment (p > 0.05). ChBF significantly increased in response to hypercapnia (p < 0.01), which was also unaffected by O2-treatment. Significant effects of age (p < 0.001) and of the interaction of age with treatment (p = 0.028) were found on IOP. IOP significantly decreased in O2-treated mice at 6 months compared to 4 months of age (p < 0.001), while IOP trended to increase with age in untreated mice. The amplitude of the b-wave from ERG was significantly increased in O2-treated DBA/2J compared to the untreated mice (p = 0.012), while the a-wave and oscillatory potentials were not significantly affected (p > 0.05). Conclusion This study investigated the effects of chronic mild hyperoxia on retinal function and on retinal and choroidal blood flow in a mouse model of glaucoma. Retinal function was improved in the O2-treated mice at late stage, despite a progressive decline of RBF and ChBF with age that was comparable to untreated mice.
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Affiliation(s)
- Eric R. Muir
- Department of Radiology, Stony Brook University, Stony Brook, NY, United States of America
- * E-mail:
| | - Saurav B. Chandra
- Research Imaging Institute, University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Divya Narayanan
- Department of Ophthalmology, University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Vincent Zhang
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, United States of America
| | - Ike Zhang
- Department of Radiology, Stony Brook University, Stony Brook, NY, United States of America
| | - Zhao Jiang
- Department of Radiology, Stony Brook University, Stony Brook, NY, United States of America
| | - Jeffrey W. Kiel
- Department of Ophthalmology, University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Timothy Q. Duong
- Department of Radiology, Albert Einstein College of Medicine, Bronx, NY, United States of America
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14
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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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15
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Roy Chowdhury U, Millar JC, Holman BH, Anderson KJ, Dosa PI, Roddy GW, Fautsch MP. Effect of ATP-sensitive Potassium Channel Openers on Intraocular Pressure in Ocular Hypertensive Animal Models. Invest Ophthalmol Vis Sci 2022; 63:15. [PMID: 35129587 PMCID: PMC8822368 DOI: 10.1167/iovs.63.2.15] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose To evaluate the effect of ATP-sensitive potassium channel openers cromakalim prodrug 1 (CKLP1) and diazoxide on IOP in three independent mouse models of ocular hypertension. Methods Baseline IOP was measured in TGFβ2 overexpression, steroid-induced, and iris dispersion (DBA/2J) ocular hypertension mouse models, followed by once daily eyedrop administration with CKLP1 (5 mM) or diazoxide (5 mM). The IOP was measured in conscious animals with a handheld rebound tonometer. Aqueous humor dynamics were assessed by a constant perfusion method. Effect of treatment on ocular tissues was evaluated by transmission electron microscopy. Results CKLP1 decreased the IOP by 20% in TGFβ2 overexpressing mice (n = 6; P < 0.0001), 24% in steroid-induced ocular hypertensive mice (n = 8; P < 0.0001), and 43% in DBA/2J mice (n = 15; P < 0.0001). Diazoxide decreased the IOP by 32% in mice with steroid-induced ocular hypertension (n = 13; P < 0.0001) and by 41% in DBA/2J mice (n = 4; P = 0.005). An analysis of the aqueous humor dynamics revealed that CKLP1 decreased the episcleral venous pressure by 29% in TGFβ2 overexpressing mice (n = 13; P < 0.0001) and by 72% in DBA/2J mice (n = 4 control, 3 treated; P = 0.0002). Diazoxide lowered episcleral venous pressure by 35% in steroid-induced ocular hypertensive mice (n = 3; P = 0.03). Tissue histology and cell morphology appeared normal when compared with controls. Accumulation of extracellular matrix was reduced in CKLP1- and diazoxide-treated eyes in the steroid-induced ocular hypertension model. Conclusions ATP-sensitive potassium channel openers CKLP1 and diazoxide effectively decreased the IOP in ocular hypertensive animal models by decreasing the episcleral venous pressure, supporting a potential therapeutic application of these agents in ocular hypertension and glaucoma.
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Affiliation(s)
| | - J Cameron Millar
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, United States
| | - Bradley H Holman
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States
| | | | - Peter I Dosa
- Institute for Therapeutics Discovery and Development, Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, United States
| | - Gavin W Roddy
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States
| | - Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, United States
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16
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Lazzara F, Amato R, Platania CBM, Conti F, Chou TH, Porciatti V, Drago F, Bucolo C. 1α,25-dihydroxyvitamin D 3 protects retinal ganglion cells in glaucomatous mice. J Neuroinflammation 2021; 18:206. [PMID: 34530842 PMCID: PMC8444391 DOI: 10.1186/s12974-021-02263-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 08/30/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Glaucoma is an optic neuropathy characterized by loss of function and death of retinal ganglion cells (RGCs), leading to irreversible vision loss. Neuroinflammation is recognized as one of the causes of glaucoma, and currently no treatment is addressing this mechanism. We aimed to investigate the anti-inflammatory and neuroprotective effects of 1,25(OH)2D3 (1α,25-dihydroxyvitamin D3, calcitriol), in a genetic model of age-related glaucomatous neurodegeneration (DBA/2J mice). METHODS DBA/2J mice were randomized to 1,25(OH)2D3 or vehicle treatment groups. Pattern electroretinogram, flash electroretinogram, and intraocular pressure were recorded weekly. Immunostaining for RBPMS, Iba-1, and GFAP was carried out on retinal flat mounts to assess retinal ganglion cell density and quantify microglial and astrocyte activation, respectively. Molecular biology analyses were carried out to evaluate retinal expression of pro-inflammatory cytokines, pNFκB-p65, and neuroprotective factors. Investigators that analysed the data were blind to experimental groups, which were unveiled after graph design and statistical analysis, that were carried out with GraphPad Prism. Several statistical tests and approaches were used: the generalized estimated equations (GEE) analysis, t-test, and one-way ANOVA. RESULTS DBA/2J mice treated with 1,25(OH)2D3 for 5 weeks showed improved PERG and FERG amplitudes and reduced RGCs death, compared to vehicle-treated age-matched controls. 1,25(OH)2D3 treatment decreased microglial and astrocyte activation, as well as expression of inflammatory cytokines and pNF-κB-p65 (p < 0.05). Moreover, 1,25(OH)2D3-treated DBA/2J mice displayed increased mRNA levels of neuroprotective factors (p < 0.05), such as BDNF. CONCLUSIONS 1,25(OH)2D3 protected RGCs preserving retinal function, reducing inflammatory cytokines, and increasing expression of neuroprotective factors. Therefore, 1,25(OH)2D3 could attenuate the retinal damage in glaucomatous patients and warrants further clinical evaluation for the treatment of optic neuropathies.
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Affiliation(s)
- Francesca Lazzara
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Rosario Amato
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
- Department of Biology, University of Pisa, Pisa, Italy
| | - Chiara Bianca Maria Platania
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
| | - Federica Conti
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy
- Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, School of Medicine, University of Catania, Catania, Italy.
- Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy.
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17
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Loizzo S, Rimondini R, Campana G, Fortuna A, Maroccia Z, Martorana A, Koch G. C57BL/6J and DBA/2J strains present opposite sex differences in flash visual evoked potential latency: A possible confusing factor in gender studies on neurological diseases' transgenic models. Brain Res Bull 2021; 176:18-24. [PMID: 34391824 DOI: 10.1016/j.brainresbull.2021.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 10/20/2022]
Abstract
The cholinergic neurotransmitter system in the brain is crucial in processing information related to cognitive, behavioral, and motor functions. A cholinergic dysfunction has been correctly described as one of the primary causes of neurodegenerative diseases. Differences in levels of acetylcholine or expression and function of receptors in selected brain areas have been indicated as one of the causes of sexual dimorphism in neurotransmission. However, variability in results among studies based on different mice strains could affect conclusions on this topic. Visual evoked potentials (VEPs) of male and female DBA/2J and C57BL/6J mice, which are two of the most common strains backgrounds in use for developing transgenic mice models of neurological diseases, have been studied. Effects induced by a single low dose of physostigmine have also been performed to evaluate the cholinergic system involvement. VEPs responses to luminous stimuli in C57BL/6J mice have shown a consistently lower latency than in DBA/2J, confirming the previous observation of strain differences in cholinergic function. Interestingly, strains present an opposite-sex difference in VEP latency not apparently related to sensitivity to physostigmine. These findings point at paying extreme attention to the choice of the genetic background of the animal model, especially in those basic and pre-clinical experiments that involve visual functioning.
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Affiliation(s)
- Stefano Loizzo
- Department of Cardiovascular, Endocrine-Metabolic and Ageing-Associated Diseases, Istituto Superiore di Sanità, Rome, Italy.
| | - Roberto Rimondini
- Department of Medical and Clinical Sciences, University of Bologna, Bologna, Italy
| | - Gabriele Campana
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Andrea Fortuna
- Department of Cardiovascular, Endocrine-Metabolic and Ageing-Associated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Zaira Maroccia
- Department of Cardiovascular, Endocrine-Metabolic and Ageing-Associated Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - Giacomo Koch
- Non-Invasive Brain Stimulation Unit, Department of Behavioral and Clinical Neurology, Santa Lucia Foundation, Rome, Italy
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18
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Amato R, Rossino MG, Cammalleri M, Timperio AM, Fanelli G, Dal Monte M, Pucci L, Casini G. The Potential of Lisosan G as a Possible Treatment for Glaucoma. Front Pharmacol 2021; 12:719951. [PMID: 34393798 PMCID: PMC8355587 DOI: 10.3389/fphar.2021.719951] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022] Open
Abstract
Lisosan G (LG), a fermented powder obtained from whole grains, is a nutritional supplement containing a variety of metabolites with documented antioxidant properties. We have recently demonstrated that orally administered LG protects diabetic rodent retinas from oxidative stress, inflammation, apoptosis, blood-retinal barrier disruption, and functional damage. Here, we investigated whether LG may exert protective effects in a model of glaucoma and measured the amounts of selected LG components that reach the retina after oral LG administration. Six-month-old DBA/2J mice were given an aqueous LG solution in place of drinking water for 2 mo. During the 2 mo of treatment with LG, the intraocular pressure (IOP) was monitored and the retinal ganglion cell (RGC) functional activity was recorded with pattern-electroretinography (PERG). At the end of the 2-mo period, the expression of oxidative stress and inflammatory markers was measured with qPCR, and RGC survival or macroglial activation were assessed with immunofluorescence. Alternatively, LG was administered by gavage and the concentrations of four of the main LG components (nicotinamide, gallic acid, 4-hydroxybenzoic acid, and quercetin) were measured in the retinas in the following 24 h using mass spectrometry. LG treatment in DBA/2J mice did not influence IOP, but it affected RGC function since PERG amplitude was increased and PERG latency was decreased with respect to untreated DBA/2J mice. This improvement of RGC function was concomitant with a significant decrease of both oxidative stress and inflammation marker expression, of RGC loss, and of macroglial activation. All four LG metabolites were found in the retina, although with different proportions with respect to the amount in the dose of administered LG, and with different temporal profiles in the 24 h following administration. These findings are consistent with neuroenhancing and neuroprotective effects of LG in glaucoma that are likely to derive from its powerful antioxidant properties. The co-occurrence of different metabolites in LG may provide an added value to their beneficial effects and indicate LG as a basis for the potential treatment of a variety of retinal pathologies.
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Affiliation(s)
- Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy
| | | | - Maurizio Cammalleri
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Anna Maria Timperio
- Department of Ecological and Biological Sciences, University of Tuscia, Viterbo, Italy
| | - Giuseppina Fanelli
- Department of Agriculture and Forest Sciences, University of Tuscia, Viterbo, Italy
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
| | - Laura Pucci
- National Research Council, Institute of Agricultural Biology and Biotechnology (IBBA), Pisa, Italy
| | - Giovanni Casini
- Department of Biology, University of Pisa, Pisa, Italy.,Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, Pisa, Italy
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19
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Amato R, Lazzara F, Chou TH, Romano GL, Cammalleri M, Dal Monte M, Casini G, Porciatti V. Diabetes Exacerbates the Intraocular Pressure-Independent Retinal Ganglion Cells Degeneration in the DBA/2J Model of Glaucoma. Invest Ophthalmol Vis Sci 2021; 62:9. [PMID: 34232257 PMCID: PMC8267218 DOI: 10.1167/iovs.62.9.9] [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] [Indexed: 12/11/2022] Open
Abstract
Purpose Glaucoma is a multifactorial disease, causing retinal ganglion cells (RGCs) and optic nerve degeneration. The role of diabetes as a risk factor for glaucoma has been postulated but still not unequivocally demonstrated. The purpose of this study is to clarify the effect of diabetes in the early progression of glaucomatous RGC dysfunction preceding intraocular pressure (IOP) elevation, using the DBA/2J mouse (D2) model of glaucoma. Methods D2 mice were injected with streptozotocin (STZ) obtaining a combined model of diabetes and glaucoma (D2 + STZ). D2 and D2 + STZ mice were monitored for weight, glycemia, and IOP from 3.5 to 6 months of age. In addition, the activity of RGC and outer retina were assessed using pattern electroretinogram (PERG) and flash electroretinogram (FERG), respectively. At the end point, RGC density and astrogliosis were evaluated in flat mounted retinas. In addition, Müller cell reactivity was evaluated in retinal cross-sections. Finally, the expression of inflammation and oxidative stress markers were analyzed. Results IOP was not influenced by time or diabetes. In contrast, RGC activity resulted progressively decreased in the D2 group independently from IOP elevation and outer retinal dysfunction. Diabetes exacerbated RGC dysfunction, which resulted independent from variation in IOP and outer retinal activity. Diabetic retinas displayed decreased RGC density and increased glial reactivity given by an increment in oxidative stress and inflammation. Conclusions Diabetes can act as an IOP-independent risk factor for the early progression of glaucoma promoting oxidative stress and inflammation-mediated RGC dysfunction, glial reactivity, and cellular death.
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Affiliation(s)
- Rosario Amato
- Department of Biology, University of Pisa, Pisa, Italy.,Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Francesca Lazzara
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, United States.,Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, United States
| | - Giovanni Luca Romano
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, United States.,Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy
| | | | | | | | - Vittorio Porciatti
- Bascom Palmer Eye Institute, Miller School of Medicine, University of Miami, Miami, Florida, United States
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20
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Modeling Retinal Ganglion Cell Dysfunction in Optic Neuropathies. Cells 2021; 10:cells10061398. [PMID: 34198840 PMCID: PMC8227951 DOI: 10.3390/cells10061398] [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] [Received: 04/19/2021] [Revised: 05/24/2021] [Accepted: 06/03/2021] [Indexed: 12/13/2022] Open
Abstract
As in glaucoma and other optic neuropathies cellular dysfunction often precedes cell death, the assessment of retinal ganglion cell (RGC) function represents a key outcome measure for neuroprotective strategies aimed at targeting distressed but still viable cells. RGC dysfunction can be assessed with the pattern electroretinogram (PERG), a sensitive measure of electrical activity of RGCs that is recorded non-invasively in human subjects and mouse models. Here, we offer a conceptual framework based on an intuitive state-transition model used for disease management in patients to identify progressive, potentially reversible stages of RGC dysfunction leading to cell death in mouse models of glaucoma and other optic neuropathies. We provide mathematical equations to describe state-transitions with a set of modifiable parameters that alter the time course and severity of state-transitions, which can be used for hypothesis testing and fitting experimental PERG data. PERG dynamics as a function of physiological stimuli are also used to differentiate phenotypic and altered RGC response dynamics, to assess susceptibility to stressors and to assess reversible dysfunction upon pharmacological treatment.
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21
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Retinal and cortical visual acuity in a common inbred albino mouse. PLoS One 2021; 16:e0242394. [PMID: 34048428 PMCID: PMC8162811 DOI: 10.1371/journal.pone.0242394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 05/12/2021] [Indexed: 11/19/2022] Open
Abstract
While albino mice are widely used in research which includes the use of visually guided behavioral tests, information on their visual capability is scarce. We compared the spatial resolution (acuity) of albino mice (BALB/c) with that of pigmented mice (C57BL/6J). We used a high-throughput pattern electroretinogram (PERG) and pattern visual evoked potential (PVEP) method for objective assessment of retinal and cortical acuity, as well as optomotor head-tracking response/ reflex (OMR). We found that PERG, PVEP, and OMR acuities of C57BL/6J mice were all in the range of 0.5-0.6 cycles/degree (cyc/deg). BALB/c mice had PERG and PVEP acuities in the range of 0.1-0.2 cyc/deg but were unresponsive to OMR stimulus. Results indicate that retinal and cortical acuity can be reliably determined with electrophysiological methods in BALB/c mice, although PERG/PVEP acuities are lower than those of C57BL/6J mice. The reduced acuity of BALB/c mice appears to be primarily determined at retinal level.
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Eastlake K, Jayaram H, Luis J, Hayes M, Khaw PT, Limb GA. Strain Specific Responses in a Microbead Rat Model of Experimental Glaucoma. Curr Eye Res 2021; 46:387-397. [PMID: 32842792 PMCID: PMC8025805 DOI: 10.1080/02713683.2020.1805472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 11/15/2022]
Abstract
PURPOSE A major challenge in glaucoma research is the lack of reproducible animal models of RGC and optic nerve damage, the characteristic features of this condition. We therefore examined the glaucomatous responses of two different rat strains, the Brown Norway (BN) and Lister Hooded (LH) rats, to high intraocular pressure (IOP) induced by injection of magnetic beads into the anterior chamber. METHODS Magnetic microsphere suspensions (20 µl of 5-20 mg/ml) were injected into the anterior chamber of BN (n = 9) or LH (N = 15) rats. Animals from each strain were divided into three groups, each receiving a different dose of microspheres. IOP was measured over 4 weeks using a rebound tonometer. Retinal ganglion cell (RGC) damage and function were assessed using scotopic electroretinograms (ERGs), retinal flatmounts and optic nerve histology. ANOVA and Student's t-tests were used to analyse the data. RESULTS A significant elevation in IOP was observed in BN rats receiving injections of 20 mg (37.18 ± 12.28 mmHg) or 10 mg microspheres/ml (36.95 ± 13.63 mmHg) when compared with controls (19.63 ± 4.29 mmHg) (p < .001) over 2 weeks. This correlated with a significant impairment of RGC function, as determined by scotopic ERG (p < .001), reduction in axon number (p < .05) and lower RGC density (P < .05) in animals receiving 20 mg or 10 mg microspheres/ml as compared with controls. LH rats receiving similar microsphere doses showed reduced scotopic ERG function (p < .001) after 2 weeks. No changes in IOP was seen in this strain, although a reduction in axon density was observed in optic nerve cross-sections (p < .05). Initial changes in IOP and ERG responses observed in BN rats remained unchanged for a duration of 7 weeks. In LH animals, ERG responses were decreased at 1-2 weeks and returned to control levels after 5 weeks. CONCLUSIONS Although this model was easily reproducible in BN rats, the phenotype of injury observed in LH rats was very different from that observed in BN animals. We suggest that differences in the glaucomatous response observed in these two strains may be ascribed to anatomical and physiological differences and merits further investigation.
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Affiliation(s)
- Karen Eastlake
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Hari Jayaram
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Joshua Luis
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Matthew Hayes
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Peng T. Khaw
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - G. Astrid Limb
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
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Regulation of distinct caspase-8 functions in retinal ganglion cells and astroglia in experimental glaucoma. Neurobiol Dis 2021; 150:105258. [PMID: 33434617 DOI: 10.1016/j.nbd.2021.105258] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/30/2020] [Accepted: 01/07/2021] [Indexed: 12/13/2022] Open
Abstract
Retinal ganglion cells (RGCs) expanding from the retina to the brain are primary victims of neurodegeneration in glaucoma, a leading cause of blindness; however, the neighboring astroglia survive the glaucoma-related stress and promote neuroinflammation. In light of diverse functions of caspase-8 in apoptosis, cell survival, and inflammation, this study investigated the importance of caspase-8 in different fates of glaucomatous RGCs and astroglia using two experimental approaches in parallel. In the first approach, cell type-specific responses of RGCs and astroglia to a caspase-8 cleavage-inhibiting pharmacological treatment were studied in rat eyes with or without experimentally induced glaucoma. The second approach utilized an experimental model of glaucoma in mice in which astroglial caspase-8 was conditionally deleted by cre/lox. Findings of these experiments revealed cell type-specific distinct processes that regulate caspase-8 functions in experimental glaucoma, which are involved in inducing the apoptosis of RGCs and promoting the survival and inflammatory responses of astroglia. Deletion of caspase-8 in astroglia protected RGCs against glia-driven inflammatory injury, while the inhibition of caspase-8 cleavage inhibited apoptosis in RGCs themselves. Various caspase-8 functions impacting both RGC apoptosis and astroglia-driven neuroinflammation may suggest the multi-target potential of caspase-8 regulation to provide neuroprotection and immunomodulation in glaucoma.
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Disturbed glucose and pyruvate metabolism in glaucoma with neuroprotection by pyruvate or rapamycin. Proc Natl Acad Sci U S A 2020; 117:33619-33627. [PMID: 33318177 PMCID: PMC7776900 DOI: 10.1073/pnas.2014213117] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Intraocular pressure-sensitive retinal ganglion cell degeneration is a hallmark of glaucoma, the leading cause of irreversible blindness. Here, we used RNA-sequencing and metabolomics to examine early glaucoma in DBA/2J mice. We demonstrate gene expression changes that significantly impact pathways mediating the metabolism and transport of glucose and pyruvate. Subsequent metabolic studies characterized an intraocular pressure (IOP)-dependent decline in retinal pyruvate levels coupled to dysregulated glucose metabolism prior to detectable optic nerve degeneration. Remarkably, retinal glucose levels were elevated 50-fold, consistent with decreased glycolysis but possibly including glycogen mobilization and other metabolic changes. Oral supplementation of the glycolytic product pyruvate strongly protected from neurodegeneration in both rat and mouse models of glaucoma. Investigating further, we detected mTOR activation at the mechanistic nexus of neurodegeneration and metabolism. Rapamycin-induced inhibition of mTOR robustly prevented glaucomatous neurodegeneration, supporting a damaging role for IOP-induced mTOR activation in perturbing metabolism and promoting glaucoma. Together, these findings support the use of treatments that limit metabolic disturbances and provide bioenergetic support. Such treatments provide a readily translatable strategy that warrants investigation in clinical trials.
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Wong VHY, Zhao D, Bui BV, Millar CJ, Nguyen CTO. Increased episcleral venous pressure in a mouse model of circumlimbal suture induced ocular hypertension. Exp Eye Res 2020; 202:108348. [PMID: 33166503 DOI: 10.1016/j.exer.2020.108348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate changes in aqueous humor dynamics during intraocular pressure (IOP) elevation induced by circumlimbal suture in mice. METHODS Ocular hypertension (OHT) was induced by applying a circumlimbal suture behind the limbus in male adult C57BL6/J mice. In the OHT group, the suture was left in place for an average of 8 weeks (n = 10, OHT group). In the sham control group the suture was cut at 2 days (n = 9, sham group) and in the naïve control group (n = 5) no suture was implanted. IOP was measured at baseline across 3 days, 1 h post-suture implantation, and at the chronic endpoint. Anterior segments were assessed using optical coherence tomography (OCT). Episcleral venous pressure (EVP), total outflow facility (C), uveoscleral outflow (Fu) and aqueous humor flow rate (Fin) were determined using a constant-flow infusion model. RESULTS All aqueous dynamic and chronic IOP outcome measures showed no difference between sham and naïve controls (p > 0.05) and thus these groups were combined into a single control group. IOP was elevated in OHT group compared with controls (p < 0.01). Chronic suture implantation did not change pupil size, anterior chamber depth or iridocorneal angles (p > 0.05). EVP was significantly higher in OHT eyes compared to control eyes (p < 0.01). There was no statistical difference in C, Fu and Fin between groups (p > 0.05). A significant linear correlation was found between IOP and EVP (R2 = 0.35, p = 0.001). CONCLUSIONS Circumlimbal suture implantation in mouse eyes results in chronic IOP elevation without angle closure. Chronic IOP elevation is likely to reflect higher EVP.
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Affiliation(s)
- Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Cameron J Millar
- North Texas Eye Research Institute, Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia.
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Rodrigo MJ, Martinez-Rincon T, Subias M, Mendez-Martinez S, Luna C, Pablo LE, Polo V, Garcia-Martin E. Effect of age and sex on neurodevelopment and neurodegeneration in the healthy eye: Longitudinal functional and structural study in the Long-Evans rat. Exp Eye Res 2020; 200:108208. [PMID: 32882213 DOI: 10.1016/j.exer.2020.108208] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 08/05/2020] [Accepted: 08/26/2020] [Indexed: 01/03/2023]
Abstract
The processes involved in neurodevelopment and aging have not yet been fully discovered. This is especially challenging in premorbid or borderline situations of neurodegenerative diseases such as Alzheimer's or glaucoma. The retina, as part of the central nervous system, can be considered the easiest and most accessible neural structure that can be analyzed using non-invasive methods. Animal studies of neuroretinal tissue in situations of health and under controlled conditions allow the earliest sex- and aging-induced changes to be analyzed so as to differentiate them from the first signs occurring in manifested disease. This study evaluates differences by age and sex based on intraocular pressure (IOP) and neuroretinal function and structure in healthy young and adult rats before decline due to senescence. For this purpose, eighty-five healthy Long-Evans rats (31 males and 54 females) were analyzed in this 6-month longitudinal study running from childhood to adulthood. IOP was measured by tonometer (Tonolab; Tiolat Oy Helsinki, Finland), neuroretinal function was recorded by flash scotopic and light-adapted photopic negative response electroretinography (ERG) (Roland consult® RETIanimal ERG, Germany) at 4, 16 and 28 weeks of age; and structure was evaluated by in vivo optical coherence tomography (OCT) (Spectralis, Heidelberg® Engineering, Germany). Analyzing both sexes together, IOP was below 20 mmHg throughout the study; retina (R), retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thicknesses measured by OCT decreased over time; an increase in ERG signal was recorded at week 16; and no differences were found between right and left eyes. However, analyzing differences by sex revealed that males had higher IOP (even reaching ocular hypertension [>20 mmHg] by the end of the study [7 months of age]), exhibited greater neuroretinal thickness but higher structural percentage loss, and had worse dark- and light-adapted function as measured by ERG than females. This study concludes that age and sex influenced neurodevelopment and neurodegeneration. Different structural and functional degenerative patterns were observed by sex; these occurred earlier and more intensely in males than in age-matched females.
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Affiliation(s)
- Maria Jesus Rodrigo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain; RETICS: Thematic Networks for Co-operative Research in Health for Ocular Diseases, Spain.
| | - Teresa Martinez-Rincon
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Manuel Subias
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Silvia Mendez-Martinez
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Coral Luna
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Luis Emilio Pablo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain; RETICS: Thematic Networks for Co-operative Research in Health for Ocular Diseases, Spain
| | - Vicente Polo
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain
| | - Elena Garcia-Martin
- Department of Ophthalmology, Miguel Servet University Hospital, Zaragoza, Miguel Servet Ophthalmology Research Group (GIMSO), Aragon Health Research Institute (IIS Aragon), University of Zaragoza, Spain; RETICS: Thematic Networks for Co-operative Research in Health for Ocular Diseases, Spain
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27
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Yang X, Zeng Q, Barış M, Tezel G. Transgenic inhibition of astroglial NF-κB restrains the neuroinflammatory and neurodegenerative outcomes of experimental mouse glaucoma. J Neuroinflammation 2020; 17:252. [PMID: 32859212 PMCID: PMC7456390 DOI: 10.1186/s12974-020-01930-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/17/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Glia-driven neuroinflammation promotes neuron injury in glaucoma that is a chronic neurodegenerative disease of the optic nerve and a leading cause of irreversible blindness. Although therapeutic modulation of neuroinflammation is increasingly viewed as a logical strategy to avoid inflammatory neurotoxicity in glaucoma, current understanding of the molecular regulation of neuroinflammation is incomplete, and the molecular targets for immunomodulation remains unknown. Growing datasets pointed to nuclear factor-kappaB (NF-κB), a key transcriptional activator of inflammation, which was identified to be most affected in glaucomatous astroglia. Using a cell type-specific experimental approach, this study aimed to determine the value of astroglial NF-κB as a potential treatment target for immunomodulation in experimental mouse glaucoma. METHODS Neuroinflammatory and neurodegenerative outcomes of experimental glaucoma were comparatively analyzed in mice with or without cre/lox-based conditional deletion of astroglial IκKβ, which is the main activating kinase involved in IκB degradation through the canonical pathway of NF-κB activation. Glial responses and the inflammatory status of the retina and optic nerve were analyzed by cell morphology and cytokine profiling, and neuron structure and function were analyzed by counting retinal ganglion cell (RGC) axons and somas and recording pattern electroretinography (PERG) responses. RESULTS Analysis of glial inflammatory responses showed immunomodulatory outcomes of the conditional transgenic deletion of IκKβ in astroglia. Various pro-inflammatory cytokines known to be transcriptional targets for NF-κB exhibited decreased production in IκKβ-deleted astroglia, which included TNF-α that can induce RGC apoptosis and axon degeneration during glaucomatous neurodegeneration. Indeed, transgenic modulation of inflammatory responses by astroglial IκKβ deletion reduced neurodegeneration at different neuronal compartments, including both RGC axons and somas, and protected PERG responses. CONCLUSIONS The findings of this study support a key role for astroglial NF-κB in neuroinflammatory and neurodegenerative outcomes of experimental glaucoma and the potential of this transcriptional regulator pathway as a glial treatment target to provide neuroprotection through immunomodulation. By pointing to a potential treatment strategy targeting the astroglia, these experimental findings are promising for future clinical translation through transgenic applications to improve the treatment of this blinding disease.
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Affiliation(s)
- Xiangjun Yang
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, 635 West 165th Street, New York, NY, 10032, USA
| | - Qun Zeng
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, 635 West 165th Street, New York, NY, 10032, USA
| | - Mine Barış
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, 635 West 165th Street, New York, NY, 10032, USA
| | - Gülgün Tezel
- Department of Ophthalmology, Vagelos College of Physicians and Surgeons, Columbia University, Edward S. Harkness Eye Institute, 635 West 165th Street, New York, NY, 10032, USA.
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Romano GL, Amato R, Lazzara F, Porciatti V, Chou TH, Drago F, Bucolo C. P2X7 receptor antagonism preserves retinal ganglion cells in glaucomatous mice. Biochem Pharmacol 2020; 180:114199. [PMID: 32798466 DOI: 10.1016/j.bcp.2020.114199] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/29/2020] [Accepted: 08/11/2020] [Indexed: 02/07/2023]
Abstract
To investigate the role of P2X7 receptor to preserve retinal ganglion cells (RGCs) structure and function in a genetic mouse model (DBA/2J mouse) of age-related glaucomatous neurodegeneration. Chronic treatment with P2X7 receptor antagonist eye drops was carried out in order to assess RGCs function and density by pattern electroretinogram (PERG) and RBPMS immunostaining, respectively. Further, microglia activation was assessed in flat-mounted retina by using Iba-1 immunostaining. Untreated glaucomatous eyes displayed significant microglia activation, alteration of PERG signal, and RGCs loss. In the P2X7 receptor antagonist-treated eyes, the PERG signal was significantly (p < 0.05) improved compared to controls, along with a significant (p < 0.05) reduction in terms of retinal microglial activation, and remarkable preservation of RGCs density. Altogether, these findings demonstrated that topical treatment with a P2X7 receptor antagonist has a neuroprotective effect on RGCs in glaucomatous mice, suggesting an appealing pharmacological approach to prevent retinal degenerative damage in optic neuropathy.
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Affiliation(s)
- Giovanni Luca Romano
- Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy; Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Rosario Amato
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, United States; Department of Biology, University of Pisa, Pisa, Italy
| | - Francesca Lazzara
- Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy; Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, FL, United States
| | - Filippo Drago
- Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy; Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy
| | - Claudio Bucolo
- Biomedical and Biotechnological Sciences Department, University of Catania, Catania, Italy; Center for Research in Ocular Pharmacology - CERFO, University of Catania, Catania, Italy
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Chou TH, Romano GL, Amato R, Porciatti V. Nicotinamide-Rich Diet in DBA/2J Mice Preserves Retinal Ganglion Cell Metabolic Function as Assessed by PERG Adaptation to Flicker. Nutrients 2020; 12:nu12071910. [PMID: 32605122 PMCID: PMC7401244 DOI: 10.3390/nu12071910] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022] Open
Abstract
Flickering light increases metabolic demand in the inner retina. Flicker may exacerbate defective mitochondrial function in glaucoma, which will be reflected in the pattern electroretinogram (PERG), a sensitive test of retinal ganglion cell (RGC) function. We tested whether flicker altered the PERG of DBA/2J (D2) glaucomatous mice and whether vitamin B3-rich diet contributed to the flicker effect. D2 mice fed with either standard chow (control, n = 10) or chow/water enriched with nicotinamide (NAM, 2000 mg/kg per day) (treated, n = 10) were monitored from 3 to 12 months. The PERG was recorded with superimposed flicker (F-PERG) at either 101 Hz (baseline) or 11 Hz (test), and baseline-test amplitude difference (adaptation) evaluated. At endpoint, flat-mounted retinas were immunostained (RBPMS and mito-tracker). F-PERG adaptation was 41% in 3-month-old D2 and decreased with age more in control D2 than in NAM-fed D2 (GEE, p < 0.01). At the endpoint, F-PERG adaptation was 0% in control D2 and 17.5% in NAM-fed D2, together with higher RGC density (2.4×), larger RGC soma size (2×), and greater intensity of mitochondrial staining (3.75×). F-PERG adaptation may provide a non-invasive tool to assess RGC autoregulation in response to increased metabolic demand and test the effect of dietary/pharmacological treatments on optic nerve disorders.
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Affiliation(s)
- Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (G.L.R.); (R.A.); (V.P.)
- Correspondence: ; Tel.: +1-305-482-4827
| | - Giovanni Luca Romano
- Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (G.L.R.); (R.A.); (V.P.)
- Department of Biomedical and Biotechnological Sciences, University of Catania, CT 95124 Catania, Italy
| | - Rosario Amato
- Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (G.L.R.); (R.A.); (V.P.)
- Department of Biology, University of Pisa, PI 56126 Pisa, Italy
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, Miami, FL 33136, USA; (G.L.R.); (R.A.); (V.P.)
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A Dietary Combination of Forskolin with Homotaurine, Spearmint and B Vitamins Protects Injured Retinal Ganglion Cells in a Rodent Model of Hypertensive Glaucoma. Nutrients 2020; 12:nu12041189. [PMID: 32340314 PMCID: PMC7230514 DOI: 10.3390/nu12041189] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 04/11/2020] [Accepted: 04/20/2020] [Indexed: 12/11/2022] Open
Abstract
There is indication that nutritional supplements protect retinal cells from degeneration. In a previous study, we demonstrated that dietary supplementation with an association of forskolin, homotaurine, spearmint extract and B vitamins efficiently counteracts retinal dysfunction associated with retinal ganglion cell (RGC) death caused by optic nerve crush. We extended our investigation on the efficacy of dietary supplementation with the use of a mouse model in which RGC degeneration depends as closely as possible on intraocular pressure (IOP) elevation. In this model, injecting the anterior chamber of the eye with methylcellulose (MCE) causes IOP elevation leading to RGC dysfunction. The MCE model was characterized in terms of IOP elevation, retinal dysfunction as determined by electrophysiological recordings, RGC loss as determined by brain-specific homeobox/POU domain protein 3A immunoreactivity and dysregulated levels of inflammatory and apoptotic markers. Except for IOP elevation, dysfunctional retinal parameters were all recovered by dietary supplementation indicating the involvement of non-IOP-related neuroprotective mechanisms of action. Our hypothesis is that the diet supplement may be used to counteract the inflammatory processes triggered by glial cell activation, thus leading to spared RGC loss and the preservation of visual dysfunction. In this respect, the present compound may be viewed as a potential remedy to be added to the currently approved drug therapies for improving RGC protection.
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31
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Zhao D, Wong VHY, Nguyen CTO, Jobling AI, Fletcher EL, Vingrys AJ, Bui BV. Reversibility of Retinal Ganglion Cell Dysfunction From Chronic IOP Elevation. Invest Ophthalmol Vis Sci 2020; 60:3878-3886. [PMID: 31529082 DOI: 10.1167/iovs.19-27113] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To test the hypothesis that the capacity for retinal ganglion cells to functionally recover from chronic IOP elevation is dependent on the duration of IOP elevation. Methods IOP elevation was induced in one eye in anesthetized (isoflurane) adult C57BL6/J mice using a circumlimbal suture. Sutures were left in place for 8 and 16 weeks (n = 30 and 28). In two other groups the suture was cut after 8 and 12 weeks (n = 30 and 28), and ganglion cell function (electroretinography) and retinal structure (optical coherence tomography) were assessed 4 weeks later. Ganglion cell density was quantified by counting RBPMS (RNA-binding protein with multiple splicing)-stained cells. Results With IOP elevation (∼10 mm Hg above baseline), ganglion cell function declined to 75% ± 8% at 8 weeks and 59% ± 4% at 16 weeks relative to contralateral control eyes. The retinal nerve fiber layer was thinner at 8 (84% ± 4%) and 16 weeks (83% ± 3%), without a significant difference in total retinal thickness. Ganglion cell function recovered with IOP normalization (suture removal) at week 8 (97% ± 7%), but not at week 12 (73% ± 6%). Ganglion cell loss was found in all groups (-8% to -13%). Conclusions In the mouse circumlimbal suture model, 12 weeks of IOP elevation resulted in irreversible ganglion cell dysfunction, whereas retinal dysfunction was fully reversible after 8 weeks of IOP elevation.
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Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Victoria, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
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Pérez de Lara MJ, Avilés-Trigueros M, Guzmán-Aránguez A, Valiente-Soriano FJ, de la Villa P, Vidal-Sanz M, Pintor J. Potential role of P2X7 receptor in neurodegenerative processes in a murine model of glaucoma. Brain Res Bull 2019; 150:61-74. [PMID: 31102752 DOI: 10.1016/j.brainresbull.2019.05.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 04/23/2019] [Accepted: 05/10/2019] [Indexed: 12/20/2022]
Abstract
Glaucoma is a common cause of visual impairment and blindness, characterized by retinal ganglion cell (RGC) death. The mechanisms that trigger the development of glaucoma remain unknown and have gained significant relevance in the study of this neurodegenerative disease. P2X7 purinergic receptors (P2X7R) could be involved in the regulation of the synaptic transmission and neuronal death in the retina through different pathways. The aim of this study was to characterize the molecular signals underlying glaucomatous retinal injury. The time-course of functional, morphological, and molecular changes in the glaucomatous retina of the DBA/2J mice were investigated. The expression and localization of P2X7R was analysed in relation with retinal markers. Caspase-3, JNK, and p38 were evaluated in control and glaucomatous mice by immunohistochemical and western-blot analysis. Furthermore, electroretinogram recordings (ERG) were performed to assess inner retina dysfunction. Glaucomatous mice exhibited changes in P2X7R expression as long as the pathology progressed. There was P2X7R overexpression in RGCs, the primary injured neurons, which correlated with the loss of function through ERG measurements. All analyzed MAPK and caspase-3 proteins were upregulated in the DBA/2J retinas suggesting a pro-apoptotic cell death. The increase in P2X7Rs presence may contribute, together with other factors, to the changes in retinal functionality and the concomitant death of RGCs. These findings provide evidence of possible intracellular pathways responsible for apoptosis regulation during glaucomatous degeneration.
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Affiliation(s)
- María J Pérez de Lara
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, E-28037, Madrid, Spain
| | - Marcelino Avilés-Trigueros
- Laboratory of Experimental Ophthalmology, Dept. of Ophthalmology, Faculty of Medicine, University of Murcia and Murcia Institute of Bio-Health Research (IMIB), E-30120, El Palmar, Murcia, Spain
| | - Ana Guzmán-Aránguez
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, E-28037, Madrid, Spain
| | - F Javier Valiente-Soriano
- Laboratory of Experimental Ophthalmology, Dept. of Ophthalmology, Faculty of Medicine, University of Murcia and Murcia Institute of Bio-Health Research (IMIB), E-30120, El Palmar, Murcia, Spain
| | - Pedro de la Villa
- Systems Biology Department, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Madrid, Spain
| | - Manuel Vidal-Sanz
- Laboratory of Experimental Ophthalmology, Dept. of Ophthalmology, Faculty of Medicine, University of Murcia and Murcia Institute of Bio-Health Research (IMIB), E-30120, El Palmar, Murcia, Spain.
| | - Jesús Pintor
- Department of Biochemistry and Molecular Biology IV, Faculty of Optics and Optometry, Complutense University of Madrid, c/Arcos de Jalón 118, E-28037, Madrid, Spain
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Mead B, Ahmed Z, Tomarev S. Mesenchymal Stem Cell-Derived Small Extracellular Vesicles Promote Neuroprotection in a Genetic DBA/2J Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci 2019; 59:5473-5480. [PMID: 30452601 PMCID: PMC6735616 DOI: 10.1167/iovs.18-25310] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose To determine if bone marrow-derived stem cell (BMSC) small extracellular vesicles (sEV) promote retinal ganglion cell (RGC) neuroprotection in the genetic DBA/2J mouse model of glaucoma for 12 months. Methods BMSC sEV and control fibroblast-derived sEV were intravitreally injected into 3-month-old DBA/2J mice once a month for 9 months. IOP and positive scotopic threshold responses were measured from 3 months: IOP was measured monthly and positive scotopic threshold responses were measured every 3 months. RGC neuroprotection was determined in wholemounts stained with RNA binding protein with multiple splicing (RBPMS), whereas axonal damage was assessed using paraphenylenediamine staining. Results As expected, DBA/2J mice developed chronic ocular hypertension beginning at 6 months. The delivery of BMSC sEV, but not fibroblast sEV, provided significant neuroprotective effects for RBPMS+ RGC while significantly reducing the number of degenerating axons seen in the optic nerve. BMSC sEV significantly preserved RGC function in 6-month-old mice, but provided no benefit at 9 and 12 months. Conclusions BMSC sEV are an effective neuroprotective treatment in a chronic model of ocular hypertension for 1 year, preserving RGC numbers and protecting against axonal degeneration.
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Affiliation(s)
- Ben Mead
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States.,Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Stanislav Tomarev
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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Park YH, Snook JD, Ostrin EJ, Kim S, Chen R, Frankfort BJ. Transcriptomic profiles of retinal ganglion cells are defined by the magnitude of intraocular pressure elevation in adult mice. Sci Rep 2019; 9:2594. [PMID: 30796289 PMCID: PMC6385489 DOI: 10.1038/s41598-019-39141-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022] Open
Abstract
Elevated intraocular pressure (IOP) is the major risk factor for glaucoma, a sight threatening disease of retinal ganglion cells (RGCs) and their axons. Despite the central importance of IOP, details of the impact of IOP elevation on RGC gene expression remain elusive. We developed a 4-step immunopanning protocol to extract adult mouse RGCs with high fidelity and used it to isolate RGCs from wild type mice exposed to 2 weeks of IOP elevation generated by the microbead model. IOP was elevated to 2 distinct levels which were defined as Mild (IOP increase >1 mmHg and <4 mmHg) and Moderate (IOP increase ≥4 mmHg). RNA sequencing was used to compare the transcriptional environment at each IOP level. Differentially expressed genes were markedly different between the 2 groups, and pathway analysis revealed frequently opposed responses between the IOP levels. These results suggest that the magnitude of IOP elevation has a critical impact on RGC transcriptional changes. Furthermore, it is possible that IOP-based set points exist within RGCs to impact the direction of transcriptional change. It is possible that this improved understanding of changes in RGC gene expression can ultimately lead to novel diagnostics and therapeutics for glaucoma.
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Affiliation(s)
- Yong H Park
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Joshua D Snook
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Edwin J Ostrin
- Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, United States
| | - Sangbae Kim
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, 77030, United States.,Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, 77030, United States
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, 77030, United States. .,Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030, United States.
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Crosbie DE, Keaney J, Tam LCS, Daniel Stamer W, Campbell M, Humphries P. Age-related changes in eye morphology and aqueous humor dynamics in DBA/2J mice using contrast-enhanced ocular MRI. Magn Reson Imaging 2019; 59:10-16. [PMID: 30660703 DOI: 10.1016/j.mri.2019.01.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/15/2019] [Accepted: 01/16/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE Here, we are testing the hypothesis that dynamic contrast enhanced MRI (DCE-MRI) is a useful approach for non-invasively evaluating age-related changes in aqueous humor outflow and its contribution to elevated intraocular pressure in the DBA/2J model of pigmentary glaucoma. METHODS A rodent-specific 7 T MRI was used to assess eye anatomy (anterior chamber (AC) and vitreous body (VB) morphology, eye size, lens size) and aqueous humor dynamics (via intravenous administration of Gd-DTPA and Gd-BOPTA contrast agents) in C57BL/6 and DBA/2J mice at 3 and 9 months of age. RESULTS Gd-MRI was used to demonstrate an anterior solute pathway into the mouse AC. Topical latanoprost treatment in C57BL/6J mice reduced Gd-BOPTA accumulation in the AC. Age-related increases in AC area, AC depth and eye size were observed in DBA/2J mice compared to C57BL/6J mice. The rate of Gd-DTPA accumulation and peak Gd-DTPA intensity was lowest in 9-month old DBA/2J mice compared to 3-month old DBA/2J mice and C57BL/6J mice at both ages. Leakage of Gd-DTPA posteriorly into the VB was also observed in 9-month old DBA/2J mice. CONCLUSIONS These studies support the idea that age-related changes in aqueous humor outflow contribute to elevated intraocular pressure (IOP) in the DBA/2J model of pigmentary glaucoma. Gd-MRI is a valuable tool for better understanding of mechanisms and dynamics of aqueous humor circulation in normal and glaucomatous mouse eyes or following topical administration of medicines to reduce IOP.
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Affiliation(s)
- Darragh E Crosbie
- Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland
| | - James Keaney
- Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland; Ross University School of Veterinary Medicine, P. O. Box 334, Basseterre, St. Kitts, Saint Kitts and Nevis
| | - Lawrence C S Tam
- Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland
| | - W Daniel Stamer
- Departments of Ophthalmology and Biomedical Engineering, Duke University, Durham, NC, USA
| | - Matthew Campbell
- Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland.
| | - Peter Humphries
- Ocular Genetics, Unit, Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland.
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Enlarged Optic Nerve Axons and Reduced Visual Function in Mice with Defective Microfibrils. eNeuro 2018; 5:eN-NWR-0260-18. [PMID: 30406200 PMCID: PMC6220594 DOI: 10.1523/eneuro.0260-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/13/2018] [Indexed: 01/13/2023] Open
Abstract
Glaucoma is a leading cause of irreversible vision loss due to retinal ganglion cell (RGC) degeneration that develops slowly with age. Elevated intraocular pressure (IOP) is a significant risk factor, although many patients develop glaucoma with IOP in the normal range. Mutations in microfibril-associated genes cause glaucoma in animal models, suggesting the hypothesis that microfibril defects contribute to glaucoma. To test this hypothesis, we investigated IOP and functional/structural correlates of RGC degeneration in mice of either sex with abnormal microfibrils due to heterozygous Tsk mutation of the fibrilin-1 gene (Fbn1Tsk/+). Although IOP was not affected, Fbn1Tsk/+ mice developed functional deficits at advanced age consistent with glaucoma, including reduced RGC responses in electroretinogram (ERG) experiments. While RGC density in the retina was not affected, the density of RGC axons in the optic nerve was significantly reduced in Fbn1Tsk/+ mice. However, reduced axon density correlated with expanded optic nerves, resulting in similar numbers of axons in Fbn1Tsk/+ and control nerves. Axons in the optic nerves of Fbn1Tsk/+ mice were significantly enlarged and axon diameter was strongly correlated with optic nerve area, as has been reported in early pathogenesis of the DBA/2J mouse model of glaucoma. Our results suggest that microfibril abnormalities can lead to phenotypes found in early-stage glaucomatous neurodegeneration. Thinning of the elastic fiber-rich pia mater was found in Fbn1Tsk/+ mice, suggesting mechanisms allowing for optic nerve expansion and a possible biomechanical contribution to determination of axon caliber.
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Fry LE, Fahy E, Chrysostomou V, Hui F, Tang J, van Wijngaarden P, Petrou S, Crowston JG. The coma in glaucoma: Retinal ganglion cell dysfunction and recovery. Prog Retin Eye Res 2018; 65:77-92. [DOI: 10.1016/j.preteyeres.2018.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/18/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
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Rathnasamy G, Foulds WS, Ling EA, Kaur C. Retinal microglia - A key player in healthy and diseased retina. Prog Neurobiol 2018; 173:18-40. [PMID: 29864456 DOI: 10.1016/j.pneurobio.2018.05.006] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/09/2018] [Accepted: 05/29/2018] [Indexed: 01/04/2023]
Abstract
Microglia, the resident immune cells of the brain and retina, are constantly engaged in the surveillance of their surrounding neural tissue. During embryonic development they infiltrate the retinal tissues and participate in the phagocytosis of redundant neurons. The contribution of microglia in maintaining the purposeful and functional histo-architecture of the adult retina is indispensable. Within the retinal microenvironment, robust microglial activation is elicited by subtle changes caused by extrinsic and intrinsic factors. When there is a disturbance in the cell-cell communication between microglia and other retinal cells, for example in retinal injury, the activated microglia can manifest actions that can be detrimental. This is evidenced by activated microglia secreting inflammatory mediators that can further aggravate the retinal injury. Microglial activation as a harbinger of a variety of retinal diseases is well documented by many studies. In addition, a change in the microglial phenotype which may be associated with aging, may predispose the retina to age-related diseases. In light of the above, the focus of this review is to highlight the role played by microglia in the healthy and diseased retina, based on findings of our own work and from that of others.
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Affiliation(s)
- Gurugirijha Rathnasamy
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore; Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, United States
| | - Wallace S Foulds
- Singapore Eye Research Institute Level 6, The Academia, Discovery Tower, 20 College Road, 169856, Singapore; University of Glasgow, Glasgow, Scotland, G12 8QQ, United Kingdom
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore
| | - Charanjit Kaur
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore.
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Struebing FL, King R, Li Y, Cooke Bailey JN, Wiggs JL, Geisert EE. Genomic loci modulating retinal ganglion cell death following elevated IOP in the mouse. Exp Eye Res 2018; 169:61-67. [PMID: 29421330 PMCID: PMC5939594 DOI: 10.1016/j.exer.2017.12.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/13/2017] [Accepted: 12/28/2017] [Indexed: 12/25/2022]
Abstract
The present study was designed to identify genomic loci modulating the susceptibility of retinal ganglion cells (RGC) to elevated intraocular pressure (IOP) in the BXD recombinant inbred mouse strain set. IOP was elevated by injecting magnetic microspheres into the anterior chamber and blocking the trabecular meshwork using a handheld magnet to impede drainage. The IOP was then measured over the next 21 days. Only animals with IOP greater than 25 mmHg for two consecutive days or an IOP above 30 mmHg on a single day after microsphere-injection were used in this study. On day 21, mice were sacrificed and the optic nerve was processed for histology. Axons were counted for both the injected and the control eye in 49 BXD strains, totaling 181 normal counts and 191 counts associated with elevated IOP. The axon loss for each strain was calculated and the data were entered into genenetwork.org. The average number of normal axons in the optic nerve across all strains was 54,788 ± 16% (SD), which dropped to 49,545 ± 20% in animals with artificially elevated IOP. Interval mapping demonstrated a relatively similar genome-wide map for both conditions with a suggestive Quantitative Trait Locus (QTL) on proximal Chromosome 3. When the relative axon loss was used to generate a genome-wide interval map, we identified one significant QTL (p < 0.05) on Chromosome 18 between 53.6 and 57 Mb. Within this region, the best candidate gene for modulating axon loss was Aldh7a1. Immunohistochemistry demonstrated ALDH7A1 expression in mouse RGCs. ALDH7A1 variants were not significantly associated with glaucoma in the NEIGHBORHOOD GWAS dataset, but this enzyme was identified as part of the butanoate pathway previously associated with glaucoma risk. Our results suggest that genomic background influences susceptibility to RGC degeneration and death in an inducible glaucoma model.
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Affiliation(s)
- Felix L Struebing
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Rebecca King
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Ying Li
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Jessica N Cooke Bailey
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, USA
| | | | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, USA
| | - Eldon E Geisert
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA.
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Anesthetic Preconditioning as Endogenous Neuroprotection in Glaucoma. Int J Mol Sci 2018; 19:ijms19010237. [PMID: 29342845 PMCID: PMC5796185 DOI: 10.3390/ijms19010237] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/09/2018] [Accepted: 01/11/2018] [Indexed: 12/15/2022] Open
Abstract
Blindness in glaucoma is the result of death of Retinal Ganglion Cells (RGCs) and their axons. RGC death is generally preceded by a stage of reversible dysfunction and structural remodeling. Current treatments aimed at reducing intraocular pressure (IOP) are ineffective or incompletely effective in management of the disease. IOP-independent neuroprotection or neuroprotection as adjuvant to IOP lowering in glaucoma remains a challenge as effective agents without side effects have not been identified yet. We show in DBA/2J mice with spontaneous IOP elevation and glaucoma that the lifespan of functional RGCs can be extended by preconditioning RGCs with retrobulbar lidocaine in one eye at four months of age that temporary blocks RGC axonal transport. The contralateral, PBS-injected eye served as control. Lidocaine-induced impairment of axonal transport to superior colliculi was assessed by intravitreal injection of cholera toxin B. Long-term (nine months) effect of lidocaine were assessed on RGC electrical responsiveness (PERG), IOP, expression of relevant protein (BDNF, TrkB, PSD95, GFAP, Synaptophysin, and GAPDH) and RGC density. While lidocaine treatment did not alter the age-related increase of IOP, TrkB expression was elevated, GFAP expression was decreased, RGC survival was improved by 35%, and PERG function was preserved. Results suggest that the lifespan of functional RGCs in mouse glaucoma can be extended by preconditioning RGCs in early stages of the disease using a minimally invasive treatment with retrobulbar lidocaine, a common ophthalmologic procedure. Lidocaine is inexpensive, safe and is approved by Food and Drug Administration (FDA) to be administered intravenously.
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Abstract
Electroretinography is a crucial assay for studying the function and the functional integrity of the retina. The mouse is an important animal model for studying the retinal neurons and circuitries. In addition, it is often used as animal model for human retinal disorders. Therefore, a good understanding of the procedures in animal handling, of the methods for data analysis and of the requirements for stimulators and for the data acquisition equipment is of importance. Here, the currently most common methods and materials for in vivo electroretinography in the mouse are discussed.
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Affiliation(s)
- Jan Kremers
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany.
| | - Naoyuki Tanimoto
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Kiel, Germany
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Kalogerou M, Kolovos P, Prokopiou E, Papagregoriou G, Deltas C, Malas S, Georgiou T. Omega-3 fatty acids protect retinal neurons in the DBA/2J hereditary glaucoma mouse model. Exp Eye Res 2017; 167:128-139. [PMID: 29258748 DOI: 10.1016/j.exer.2017.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 11/15/2017] [Accepted: 12/11/2017] [Indexed: 12/31/2022]
Abstract
The purpose of this study was to evaluate the neuroprotective effects of omega-3 polyunsaturated fatty acid (ω3-PUFA) supplementation, alone or in combination with timolol eye drops, in a mouse model of hereditary glaucoma. DBA/2J mice (8.5-month-old) were assigned to an ω3-PUFAs + timolol, ω3-PUFAs only, timolol only, or an untreated group. Treated mice received a daily gavage administration of eicosapentaenoic acid (EPA) and docosahexaenoic acid and/or topical instillation of timolol (0.5%) once a day for 3 months. Blood was analysed regularly to determine ω3-PUFA levels and retinas were histologically analysed. Real-time PCR and Western blot were performed for retinal pro-inflammatory cytokines and macrophages. Blood arachidonic acid/EPA ratio gradually decreased and reached the desired therapeutic range (1-1.5) after 4 weeks of daily gavage with ω3-PUFAs in the ω3-PUFAs + timolol and ω3-PUFAs only groups. Retinal ganglion cell densities were significantly higher in the ω3-PUFAs + timolol (1303.77 ± 139.62/mm2), ω3-PUFAs only (768.40 ± 52.44/mm2) and timolol only (910.57 ± 57.28/mm2) groups than in the untreated group (323.39 ± 95.18/mm2). ω3-PUFA supplementation alone or timolol alone, significantly increased protein expression levels of M1 macrophage-secreted inducible nitric oxide synthase and M2 macrophage-secreted arginase-1 in the retina, which led to significant decreases in the expression levels of tumour necrosis factor-α (TNF-α). ω3-PUFA supplementation alone also resulted in significantly reduced expression of interleukin-18 (IL-18). ω3-PUFA + timolol treatment had no effect on the expression level of any of the aforementioned mediators in the retina. Supplementation with ω3-PUFAs has neuroprotective effect in the retinas of DBA/2J mice that is enhanced when combined with timolol eye drops. The continued inflammation following ω3-PUFAs + timolol treatment suggests that downregulation of IL-18 and TNF-α may not be the only factors involved in ω3-PUFA-mediated neuroprotection in the retina.
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MESH Headings
- Administration, Ophthalmic
- Adrenergic beta-Antagonists/therapeutic use
- Animals
- Arachidonic Acid/blood
- Arginase/metabolism
- Blotting, Western
- Cell Survival
- Disease Models, Animal
- Drug Combinations
- Eicosapentaenoic Acid/blood
- Fatty Acids, Omega-3/administration & dosage
- Female
- Glaucoma, Open-Angle/genetics
- Glaucoma, Open-Angle/metabolism
- Glaucoma, Open-Angle/prevention & control
- Interleukin-18/metabolism
- Intraocular Pressure/drug effects
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Nitric Oxide Synthase Type II/metabolism
- Ophthalmic Solutions
- Optic Nerve Diseases/genetics
- Optic Nerve Diseases/metabolism
- Optic Nerve Diseases/prevention & control
- Real-Time Polymerase Chain Reaction
- Retinal Ganglion Cells/drug effects
- Timolol/therapeutic use
- Tonometry, Ocular
- Tumor Necrosis Factor-alpha/metabolism
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Affiliation(s)
- Maria Kalogerou
- Ophthalmos Research and Educational Institute, Morfou 48, Egkomi, 2417 Nicosia, Cyprus.
| | - Panagiotis Kolovos
- Ophthalmos Research and Educational Institute, Morfou 48, Egkomi, 2417 Nicosia, Cyprus.
| | - Ekatherine Prokopiou
- Ophthalmos Research and Educational Institute, Morfou 48, Egkomi, 2417 Nicosia, Cyprus.
| | - Gregory Papagregoriou
- Molecular Medicine Research Centre and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Kallipoleos 75, 1678 Nicosia, Cyprus.
| | - Constantinos Deltas
- Molecular Medicine Research Centre and Laboratory of Molecular and Medical Genetics, Department of Biological Sciences, University of Cyprus, Kallipoleos 75, 1678 Nicosia, Cyprus.
| | - Stavros Malas
- Developmental and Functional Genetics Group, The Cyprus Institute of Neurology and Genetics, 1683 Nicosia, Cyprus.
| | - Tassos Georgiou
- Ophthalmos Research and Educational Institute, Morfou 48, Egkomi, 2417 Nicosia, Cyprus.
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Turner AJ, Vander Wall R, Gupta V, Klistorner A, Graham SL. DBA/2J mouse model for experimental glaucoma: pitfalls and problems. Clin Exp Ophthalmol 2017; 45:911-922. [PMID: 28516453 DOI: 10.1111/ceo.12992] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 05/04/2017] [Accepted: 05/11/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND The DBA/2J mouse has been described as a model for congenital experimental glaucoma. It develops anterior segment anomalies with synechiae and pigment dispersion leading to raised intraocular pressure and glaucomatous damage. However, there are serious practical considerations when using this model in longitudinal studies. METHODS We followed 118 mice from 12-48 weeks of age in a pharmaceutical trial. Here we report on the findings in control animals (n = 37). Intraocular pressure was measured weekly, electrophysiology and optical coherence tomography every 6 weeks. A subset also had invasive intraocular pressure measurements performed prior to euthanasia. RESULTS Although intraocular pressure eventually rose by 9 months in most animals, tonometry was complicated by corneal calcification in the majority of animals rendering intraocular pressure measurement unreliable. Invasive intraocular pressure did not correlate with non-invasive measures. Loss of scotopic threshold response and thinning of inner retinal layers on optical coherence tomography was observed over time, suggesting glaucomatous damage, but this occurred in some animals without raised intraocular pressure. Poor pupil dilation significantly affected electrophysiology, optical coherence tomography and fundus imaging; 22% of animals developed major systemic complications leading to high dropout rate. CONCLUSIONS The DBA/2J experimental glaucoma model shows variability in expression, and its pathological changes cause major difficulties in assessing disease progression. From our experience, the model presents significant challenges for drug studies in glaucoma, as there are many confounding factors: difficulty with accurate intraocular pressure measurement, in vivo imaging, and electrophysiology recording and a high dropout rate. In addition, there may be an underlying neurodegenerative process independent of intraocular pressure.
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Affiliation(s)
- Anita J Turner
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Roshana Vander Wall
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Vivek Gupta
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Alex Klistorner
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, New South Wales, Australia
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Sun D, Moore S, Jakobs TC. Optic nerve astrocyte reactivity protects function in experimental glaucoma and other nerve injuries. J Exp Med 2017; 214:1411-1430. [PMID: 28416649 PMCID: PMC5413323 DOI: 10.1084/jem.20160412] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 12/05/2016] [Accepted: 03/08/2017] [Indexed: 01/06/2023] Open
Abstract
Reactive remodeling of optic nerve head astrocytes is consistently observed in glaucoma and other optic nerve injuries. However, it is unknown whether this reactivity is beneficial or harmful for visual function. In this study, we used the Cre recombinase (Cre)-loxP system under regulation of the mouse glial fibrillary acidic protein promoter to knock out the transcription factor signal transducer and activator of transcription 3 (STAT3) from astrocytes and test the effect this has on reactive remodeling, ganglion cell survival, and visual function after experimental glaucoma and nerve crush. After injury, STAT3 knockout mice displayed attenuated astrocyte hypertrophy and reactive remodeling; astrocytes largely maintained their honeycomb organization and glial tubes. These changes were associated with increased loss of ganglion cells and visual function over a 30-day period. Thus, reactive astrocytes play a protective role, preserving visual function. STAT3 signaling is an important mediator of various aspects of the reactive phenotype within optic nerve astrocytes.
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Affiliation(s)
- Daniel Sun
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114
| | - Sara Moore
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114
| | - Tatjana C Jakobs
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114
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Williams PA, Harder JM, Foxworth NE, Cochran KE, Philip VM, Porciatti V, Smithies O, John SWM. Vitamin B 3 modulates mitochondrial vulnerability and prevents glaucoma in aged mice. Science 2017; 355:756-760. [PMID: 28209901 PMCID: PMC5408298 DOI: 10.1126/science.aal0092] [Citation(s) in RCA: 370] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/23/2016] [Indexed: 12/25/2022]
Abstract
Glaucomas are neurodegenerative diseases that cause vision loss, especially in the elderly. The mechanisms initiating glaucoma and driving neuronal vulnerability during normal aging are unknown. Studying glaucoma-prone mice, we show that mitochondrial abnormalities are an early driver of neuronal dysfunction, occurring before detectable degeneration. Retinal levels of nicotinamide adenine dinucleotide (NAD+, a key molecule in energy and redox metabolism) decrease with age and render aging neurons vulnerable to disease-related insults. Oral administration of the NAD+ precursor nicotinamide (vitamin B3), and/or gene therapy (driving expression of Nmnat1, a key NAD+-producing enzyme), was protective both prophylactically and as an intervention. At the highest dose tested, 93% of eyes did not develop glaucoma. This supports therapeutic use of vitamin B3 in glaucoma and potentially other age-related neurodegenerations.
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Affiliation(s)
| | | | | | | | | | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Oliver Smithies
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME 04609, USA.
- Department of Ophthalmology, Tufts University of Medicine, Boston, MA 02111, USA
- The Howard Hughes Medical Institute, Bar Harbor, ME 04609, USA
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Mysona B, Kansara N, Zhao J, Bollinger K. The Role of Sigma 1 Receptor as a Neuroprotective Target in Glaucoma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:299-307. [PMID: 28315279 DOI: 10.1007/978-3-319-50174-1_20] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The role of sigma 1 receptor (S1R) in glaucoma is emerging as a promising field of study. Glaucoma is an optic neuropathy that shares common pathogenic mechanisms with other neurodegenerative diseases such as Alzheimer's and Parkinson's disease . S1R modulates multiple cellular functions associated with neurodegeneration . These include Ca2+ ion homeostasis, endoplasmic reticulum (ER) and oxidative stress , survival signaling pathways, neurotrophin secretion, and glial activation. S1R may also have neurorestorative properties including enhancement of neuronal plasticity and neurite outgrowth. Recent studies using agonists for S1R within the eye provide hope that it could be a therapeutic target for glaucoma. Understanding the role of S1R in glaucoma may help us to stop the progression of this sight threatening disease.
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Affiliation(s)
- Barbara Mysona
- Departments of Cellular Biology and Anatomy and Ophthalmology and the James and Jean Culver Vision Discovery Institute, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Neil Kansara
- Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA
| | - Jing Zhao
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Kathryn Bollinger
- Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
- The James and Jean Culver Vision Discovery Institute, Augusta, GA, 30912, USA.
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA.
- Department of Cellular Biology and Anatomy, Augusta University, Augusta, GA, 30912, USA.
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Chandra S, Muir ER, Deo K, Kiel JW, Duong TQ. Effects of Dorzolamide on Retinal and Choroidal Blood Flow in the DBA/2J Mouse Model of Glaucoma. Invest Ophthalmol Vis Sci 2016; 57:826-31. [PMID: 26934140 PMCID: PMC4777278 DOI: 10.1167/iovs.15-18291] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To test the hypothesis that acute topical dorzolamide (DZ) decreases intraocular pressure (IOP) and increases retinal and choroidal blood flow in the DBA/2J mouse model of glaucoma. METHODS Retinal and choroidal blood flow were measured in 4- and 9-month-old DBA/2J mice, and 4-month C57BL/6 (control) mice under isoflurane anesthesia using magnetic resonance imaging. Ocular blood flow was measured at baseline, and 1 and 2 hours after topical dorzolamide. Intraocular pressure was measured using a rebound tonometer in a subset of animals at the same time points. RESULTS Baseline IOP in the 4-month-old DBA/2J mice and C57BL/6 mice was not significantly different (P > 0.05), and IOP in both groups was less than in the 9-month-old DBA/2J mice (P < 0.05 for both). Compared to baseline, dorzolamide reduced IOP at 1 and 2 hours after dorzolamide in the 4- (P < 0.05) and 9-month-old (P < 0.01) DBA/2J mice, but not in the C57BL/6J mice (P > 0.05). Baseline retinal blood flow was lower in the 4-month and 9-month-old DBA/2J mice compared with the 4-month-old C57BL/6J mice (P < 0.05). Baseline choroidal blood flow in the 9-month-old DBA/2J mice was less than in the C57BL/6J mice (P < 0.05). Compared with baseline, both retinal and choroidal blood flow increased at 1-hour post-dorzolamide and remained elevated 2 hours later in the 9-month-old DBA/2J mice (P < 0.05). CONCLUSIONS Dorzolamide lowers IOP and raises retinal and choroidal blood flow in older DBA/2J mice, consistent with the study hypothesis.
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Central visual pathways in glaucoma: evidence for distal mechanisms of neuronal self-repair. J Neuroophthalmol 2016; 35 Suppl 1:S29-37. [PMID: 26274834 DOI: 10.1097/wno.0000000000000291] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
As in other age-related neurodegenerative diseases, progression of neurodegeneration in glaucoma involves early axonopathy. In glaucoma, this is marked by degradation of active transport along retinal ganglion cell (RGC) axons projecting from the retina to the brain. In experimental systems, transport degradation occurs first in the most distal site in the RGC projection, the superior colliculus (SC) of the midbrain. Even as degradation progresses from one retinotopic sector to the next, important structures in the affected sectors persist, including synapses from RGC axon terminals onto SC neurons. This structural persistence is accompanied by focally increased brain-derived neurotrophic factor in hypertrophic SC astrocyte glia and defines a therapeutic window of opportunity. Thus, central brain structures in glaucoma may respond to disease-relevant stress by induction of mechanisms useful for maintaining retinal signals.
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Williams PA, Tribble JR, Pepper KW, Cross SD, Morgan BP, Morgan JE, John SWM, Howell GR. Inhibition of the classical pathway of the complement cascade prevents early dendritic and synaptic degeneration in glaucoma. Mol Neurodegener 2016; 11:26. [PMID: 27048300 PMCID: PMC4822272 DOI: 10.1186/s13024-016-0091-6] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/13/2022] Open
Abstract
Background Glaucoma is a complex, multifactorial disease characterised by the loss of retinal ganglion cells and their axons leading to a decrease in visual function. The earliest events that damage retinal ganglion cells in glaucoma are currently unknown. Retinal ganglion cell death appears to be compartmentalised, with soma, dendrite and axon changes potentially occurring through different mechanisms. There is mounting evidence from other neurodegenerative diseases suggesting that neuronal dendrites undergo a prolonged period of atrophy, including the pruning of synapses, prior to cell loss. In addition, recent evidence has shown the role of the complement cascade in synaptic pruning in glaucoma and other diseases. Results Using a genetic (DBA/2J mouse) and an inducible (rat microbead) model of glaucoma we first demonstrate that there is loss of retinal ganglion cell synapses and dendrites at time points that precede axon or soma loss. We next determine the role of complement component 1 (C1) in early synaptic loss and dendritic atrophy during glaucoma. Using a genetic knockout of C1qa (D2.C1qa-/- mouse) or pharmacological inhibition of C1 (in the rat bead model) we show that inhibition of C1 is sufficient to preserve dendritic and synaptic architecture. Conclusions This study further supports assessing the potential for complement-modulating therapeutics for the prevention of retinal ganglion cell degeneration in glaucoma.
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Affiliation(s)
| | - James R Tribble
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | | | - Stephen D Cross
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - B Paul Morgan
- Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Department of Ophthalmology, Tufts University of Medicine, Boston, MA, 02111, USA. .,The Howard Hughes Medical Institute, Bar Harbor, ME, 04609, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA. .,Graduate Program in Genetics, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA, USA.
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Martinez-Aguila A, Fonseca B, Perez de Lara MJ, Pintor J. Effect of Melatonin and 5-Methoxycarbonylamino-N-Acetyltryptamine on the Intraocular Pressure of Normal and Glaucomatous Mice. ACTA ACUST UNITED AC 2016; 357:293-9. [DOI: 10.1124/jpet.115.231456] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/02/2016] [Indexed: 01/02/2023]
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