1
|
Girkin CA, Strickland RG, Somerville MM, Anne Garner M, Grossman GH, Blake A, Kumar N, Ianov L, Fazio MA, Clark ME, Gross AK. Acute ocular hypertension in the living human eye: Model description and initial cellular responses to elevated intraocular pressure. Vision Res 2024; 223:108465. [PMID: 39173459 DOI: 10.1016/j.visres.2024.108465] [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: 06/05/2024] [Revised: 08/02/2024] [Accepted: 08/02/2024] [Indexed: 08/24/2024]
Abstract
This initial methods study presents the initial immunohistochemical and transcriptomic changes in the optic nerve head and retina from three research-consented brain-dead organ donors following prolonged and transient intraocular pressure (IOP) elevation. In this initial study, research-consented brain-dead organ donors were exposed to unilateral elevation of IOP for 7.5 h (Donor 1), 30 h (Donor 2), and 1 h (Donor 3) prior to organ procurement. Optic nerve tissue and retinal tissue was obtained following organ procurement for immunohistological and transcriptomic analysis. Optic nerve sections in Donor 1 exposed to 7.5-hours of unilateral sub-ischemic IOP elevation demonstrated higher levels of protein expression of the astrocytic marker, glial fibrillary acidic protein (GFAP), within the lamina cribrosa with greatest expression inferior temporally in the treated eye compared to control. Spatial transcriptomic analysis performed on optic nerve head tissues from Donor 2 exposed to 30 h of unilateral IOP elevation demonstrated differential transcription of mRNA across laminar and scleral regions. Immunohistochemistry of retinal sections from Donor 2 exhibited higher GFAP and IBA1 expression in the treated eye compared with control, but this was not observed in Donor 3, which was exposed to only 1-hour of IOP elevation. While there were no differences in GFAP protein expression in the retina following the 1-hour IOP elevation in Donor 3, there were higher levels of transcription of GFAP in the inner nuclear layer, and CD44 in the retinal ganglion cell layer, indicative of astrocytic and Müller glial reactivity as well as an early inflammatory response, respectively. We found that transcriptomic differences can be observed across treated and control eyes following unilateral elevation of IOP in brain dead organ donors. The continued development of this model affords the unique opportunity to define the acute mechanotranscriptomic response of the optic nerve head, evaluate the injury and repair mechanisms in the retina in response to IOP elevation, and enable correlation of in vivo imaging and functional testing with ex vivo cellular responses for the first time in the living human eye.
Collapse
Affiliation(s)
- Christopher A Girkin
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Ryan G Strickland
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - McKenna M Somerville
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mary Anne Garner
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Alan Blake
- Advancing Sight Network, Birmingham, AL, USA
| | - Nilesh Kumar
- IRCP-Biological Data Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Lara Ianov
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; IRCP-Biological Data Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Massimo A Fazio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mark E Clark
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alecia K Gross
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
| |
Collapse
|
2
|
Lee PY, Bui BV. Age-related differences in retinal function and structure in C57BL/6J and Thy1-YFPh mice. Neurobiol Aging 2024; 141:171-181. [PMID: 38964014 DOI: 10.1016/j.neurobiolaging.2024.06.005] [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: 11/30/2023] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/06/2024]
Abstract
Age-related neuronal adaptations are known to help maintain function. This study aims to examine gross age-related in vivo retinal functional adaptations (using electroretinography) in young and middle aged C57BL/6J and Thy1-YFPh mice and to relate this to in vivo retinal structure (using optical coherence tomography). Electroretinography responses were generally larger in Thy1-YFPh mice than in C57BL/6J mice, with similar in vivo retinal layer thicknesses except for longer inner/outer photoreceptor segment in Thy1-YFPh mice. Relative to 3-month-old mice, 12-month-old mice showed reduced photoreceptor (C57BL/6J 84.0±2.5 %; Thy1-YFPh 80.2±5.2 %) and bipolar cell (C57BL/6J 75.6±2.3 %; Thy1-YFPh 68.1±5.5 %) function. There was relative preservation of ganglion cell function (C57BL/6J 79.7±3.7 %; Thy1-YFPh 91.7±5.0 %) with age, which was associated with increased b-wave (bipolar cell) sensitivities to light. Ganglion cell function was correlated with both b-wave amplitude and sensitivity. This study shows that there are normal age-related adaptations to preserve functional output. Different mouse strains may have varied age-related adaptation capacity and should be taken into consideration when examining age-related susceptibility to injury.
Collapse
Affiliation(s)
- Pei Ying Lee
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia.
| |
Collapse
|
3
|
Lai JY, Mclarnon P, Sheridan C, Vallabh NA. Evaluating the impact of caloric restriction, body mass index and exercise on primary open-angle glaucoma: A review. Eur J Ophthalmol 2024:11206721241274445. [PMID: 39169764 DOI: 10.1177/11206721241274445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
This literature review evaluates any possible links between primary open-angle glaucoma (POAG) and caloric restriction (CR), body mass index (BMI), and exercise, aiming to map the extent of the literature. Its primary objective is to recognise the nature and breadth of research evidence, identify possible gaps in these topics and develop future studies. The databases searched were MEDLINE (PudMed), Scopus and ScienceDirect, in April 2023 for articles published in English, with no date restriction. A total of 447 search results were retrieved. Of these, 73 were related to CR, 249 to BMI, and 125 to exercise. Records identified included systematic reviews, meta-analyses, randomised controlled trials, cohort studies and animal studies. CR has been shown to halt the degeneration of retinal ganglion cells and protect against various glaucomatous processes in animal models. Low BMI has been shown to be associated with an increased risk of POAG and a faster rate of visual field deterioration in POAG. However, the association between high BMI and POAG is not consistent. Exercise has been shown to cause mechanical, vascular, and neurobiological changes affecting the pathophysiology of POAG. The present review helps identify key characteristics and factors relating to the impacts of CR, BMI, or exercise on POAG.
Collapse
Affiliation(s)
- Jonathan Ym Lai
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
| | - Patrick Mclarnon
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Carl Sheridan
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Neeru A Vallabh
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| |
Collapse
|
4
|
Stone J, Mason R, Mitrofanis J, Johnstone DM. Trace Toxins: The Key Component of a Healthful Diet. Dose Response 2024; 22:15593258241271692. [PMID: 39114768 PMCID: PMC11301730 DOI: 10.1177/15593258241271692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Accepted: 06/26/2024] [Indexed: 08/10/2024] Open
Abstract
Although it is well established that a vegetable-rich (Mediterranean) diet is associated with health benefits in later life, the mechanisms and biological origins of this benefit are not well established. This review seeks to identify the components a healthful diet that reduce the individual's suffering from non-communicable disease and extend longevity. We note the difference between the claims made for an essential diet (that prevents deficiency syndromes) and those argued for a diet that also prevents or delays non-communicable diseases and ask: what chemicals in our food induce this added resilience, which is effective against cardiovascular and neurodegenerative diseases, diabetes and even cancer? Working in the framework of acquired resilience (tissue resilience induced by a range of stresses), we arguethat the toxins evolved by plants as part of allelopathy (the competition between plant species) are key in making the 'healthful difference'. We further suggest the recognition of a category of micronutrients additional to the established 'micro' categories of vitamins and trace elements and suggest also that the new category be called 'trace toxins'. Implications of these suggestions are discussed.
Collapse
Affiliation(s)
| | - Rebecca Mason
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - John Mitrofanis
- Université Grenoble Alpes, Fonds de Dotation, Clinatec, Grenoble and Institute of Ophthalmology, University College London, London, UK
| | - Daniel M. Johnstone
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW, Australia
| |
Collapse
|
5
|
Sripinun P, See LP, Nikonov S, Chavali VRM, Vrathasha V, He J, O'Brien JM, Xia J, Lu W, Mitchell CH. Piezo1 and Piezo2 channels in retinal ganglion cells and the impact of Piezo1 stimulation on light-dependent neural activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.25.599602. [PMID: 38979351 PMCID: PMC11230181 DOI: 10.1101/2024.06.25.599602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Piezo channels are associated with neuropathology in diseases like traumatic brain injury and glaucoma, but pathways linking tissue stretch to aberrant neural signaling remain unclear. The present study demonstrates that Piezo1 activation increases action potential frequency in response to light and the spontaneous dark signal from mouse retinal explants. Piezo1 stimulation was sufficient to increase cytoplasmic Ca 2+ in soma and neurites, while stretch increased spiking activity in current clamp recordings from of isolated retinal ganglion cells (RGCs). Axon-marker beta-tubulin III colocalized with both Piezo1 and Piezo2 protein in the mouse optic nerve head, while RGC nuclear marker BRN3A colocalized with Piezo channels in the soma. Piezo1 was also present on GFAP-positive regions in the optic nerve head and colocalized with glutamine synthetase in the nerve fiber layer, suggesting expression in optic nerve head astrocytes and Müller glia end feet, respectively. Human RGCs from induced pluripotent stem cells also expressed Piezo1 and Piezo2 in soma and axons, while staining patterns in rats resembled those in mice. mRNA message for Piezo1 was greatest in the RPE/choroid tissue, while Piezo2 levels were highest in the optic nerve, with both channels also expressed in the retina. Increased expression of Piezo1 and Piezo2 occurred both 1 and 10 days after a single stretch in vivo; this increase suggests a potential role in rising sensitivity to repeated nerve stretch. In summary, Piezo1 and Piezo2 were detected in the soma and axons of RGCs, and stimulation affected the light-dependent output of RGCs. The rise in RGCs excitability induced by Piezo stimulation may have parallels to the early disease progression in models of glaucoma and other retinal degenerations. Highlights Activation of Piezo1 excites retinal ganglion cells, paralleling the early neurodegenerative progression in glaucoma mouse models and retinal degeneration.Piezo1 and Piezo2 were expressed in axons and soma of retinal ganglion cells in mice, rats, and human iPSC-RGCs.Functional assays confirmed Piezo1 in soma and neurites of neurons. Sustained elevation of Piezo1 and Piezo2 occurred after a single transient stretch may enhance damage from repeated traumatic nerve injury. Abstract Figure
Collapse
|
6
|
Becker S, L'Ecuyer Z, Jones BW, Zouache MA, McDonnell FS, Vinberg F. Modeling complex age-related eye disease. Prog Retin Eye Res 2024; 100:101247. [PMID: 38365085 PMCID: PMC11268458 DOI: 10.1016/j.preteyeres.2024.101247] [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: 08/15/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Modeling complex eye diseases like age-related macular degeneration (AMD) and glaucoma poses significant challenges, since these conditions depend highly on age-related changes that occur over several decades, with many contributing factors remaining unknown. Although both diseases exhibit a relatively high heritability of >50%, a large proportion of individuals carrying AMD- or glaucoma-associated genetic risk variants will never develop these diseases. Furthermore, several environmental and lifestyle factors contribute to and modulate the pathogenesis and progression of AMD and glaucoma. Several strategies replicate the impact of genetic risk variants, pathobiological pathways and environmental and lifestyle factors in AMD and glaucoma in mice and other species. In this review we will primarily discuss the most commonly available mouse models, which have and will likely continue to improve our understanding of the pathobiology of age-related eye diseases. Uncertainties persist whether small animal models can truly recapitulate disease progression and vision loss in patients, raising doubts regarding their usefulness when testing novel gene or drug therapies. We will elaborate on concerns that relate to shorter lifespan, body size and allometries, lack of macula and a true lamina cribrosa, as well as absence and sequence disparities of certain genes and differences in their chromosomal location in mice. Since biological, rather than chronological, age likely predisposes an organism for both glaucoma and AMD, more rapidly aging organisms like small rodents may open up possibilities that will make research of these diseases more timely and financially feasible. On the other hand, due to the above-mentioned anatomical and physiological features, as well as pharmacokinetic and -dynamic differences small animal models are not ideal to study the natural progression of vision loss or the efficacy and safety of novel therapies. In this context, we will also discuss the advantages and pitfalls of alternative models that include larger species, such as non-human primates and rabbits, patient-derived retinal organoids, and human organ donor eyes.
Collapse
Affiliation(s)
- Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Zia L'Ecuyer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Bryan W Jones
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Moussa A Zouache
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Fiona S McDonnell
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
7
|
van Koeverden AK, Afiat BC, Nguyen CT, Bui BV, Lee PY. Understanding how ageing impacts ganglion cell susceptibility to injury in glaucoma. Clin Exp Optom 2024; 107:147-155. [PMID: 37980904 DOI: 10.1080/08164622.2023.2279734] [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: 06/17/2023] [Accepted: 10/31/2023] [Indexed: 11/21/2023] Open
Abstract
Glaucoma is a leading cause of blindness worldwide, with a marked increase in prevalence with advancing age. Due to the multifactorial nature of glaucoma pathogenesis, dissecting how ageing impacts upon glaucoma risk requires analysis and synthesis of evidence from a vast literature. While there is a wealth of human clinical studies examining glaucoma pathogenesis and why older patients have increased risk, many aspects of the disease such as adaptations of retinal ganglion cells to stress, autophagy and the role of glial cells in glaucoma, require the use of animal models to study the complex cellular processes and interactions. Additionally, the accelerated nature of ageing in rodents facilitates the longitudinal study of changes that would not be feasible in human clinical studies. This review article examines evidence derived predominantly from rodent models on how the ageing process impacts upon various aspects of glaucoma pathology from the retinal ganglion cells themselves, to supporting cells and tissues such as glial cells, connective tissue and vasculature, in addition to oxidative stress and autophagy. An improved understanding of how ageing modifies these factors may lead to the development of different therapeutic strategies that target specific risk factors or processes involved in glaucoma.
Collapse
Affiliation(s)
- Anna K van Koeverden
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Brianna C Afiat
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Christine To Nguyen
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Pei Ying Lee
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| |
Collapse
|
8
|
Koçyiğit E, Gövez NE, Arslan S, Ağagündüz D. A narrative review on dietary components and patterns and age-related macular degeneration. Nutr Res Rev 2024:1-28. [PMID: 38221852 DOI: 10.1017/s0954422424000015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Age-related macular degeneration (AMD) is one of the most prevalent eye diseases among the ageing population worldwide. It is a leading cause of blindness in individuals over 55, particularly in industrialised Western countries. The prevalence of AMD increases with age, and genetic factors and environmental influences are believed to contribute to its development. Among the environmental factors, diet plays a significant role in AMD. This review explores the association between dietary components, dietary patterns and AMD. Various nutrients, non-nutrient substances and dietary models that have the potential to counteract oxidative stress and inflammation, which are underlying mechanisms of AMD, are discussed. Consuming fruits, vegetables, fish and seafood, whole grains, olive oil, nuts and low-glycaemic-index foods has been highlighted as beneficial for reducing the risk of AMD. Adhering to the Mediterranean diet, which encompasses these elements, can be recommended as a dietary pattern for AMD. Furthermore, the modulation of the gut microbiota through dietary interventions and probiotics has shown promise in managing AMD.
Collapse
Affiliation(s)
- Emine Koçyiğit
- Department of Nutrition and Dietetics, Ordu University, Ordu, Türkiye
| | - Nazlıcan Erdoğan Gövez
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
| | - Sabriye Arslan
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
| | - Duygu Ağagündüz
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Ankara, Türkiye
| |
Collapse
|
9
|
Chrysostomou V, Bell KC, Ng SW, Suresh S, Karthik G, Millet M, Chung Y, Crowston JG. A new model of axon degeneration in the mouse optic nerve using repeat intraocular pressure challenge. Exp Eye Res 2024; 238:109722. [PMID: 37952724 DOI: 10.1016/j.exer.2023.109722] [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: 08/16/2023] [Revised: 10/29/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
We characterize a new experimental model for inducing retinal ganglion cell (RGC) dysfunction and degeneration in mice. C57BL/6J mice were subjected to two acute periods of intraocular pressure (IOP) elevation (50 mmHg for 30 min) by cannulation of the anterior chamber. We used full-field electroretinography and visual evoked potentials (VEPs) to measure subsequent changes in retina and optic nerve function, and histochemical techniques to assess RGC survival and optic nerve structure. In 12 month old mice, a single IOP challenge caused loss and subsequent recovery of RGC function over the following 28 days with minimal cell death and no observed axonal damage. A second identical IOP challenge resulted in persistent RGC dysfunction and significant (36%) loss of RGC somas. This was accompanied by a 16.7% delay in the latency and a 27.6% decrease in the amplitude of the VEP. Severe axonal damage was seen histologically with enlargement of axons, myelin disruption, reduced axon density, and the presence of glial scarring. In contrast, younger 3 month old mice when exposed to a single or repeat IOP challenge showed quicker RGC functional recovery after a single challenge and full functional recovery after a repeat challenge with no detectable optic nerve dysfunction. These data demonstrate a highly reproducible and minimally invasive method for inducing RGC degeneration and axonal damage in mice. Resilience of the optic nerve to damage is highly dependent on animal age. The time-defined nature of functional versus structural loss seen in this model stands to facilitate investigation of neuroglial responses in the retina after IOP injury and the associated evaluation of neuroprotective treatment strategies. Further, the model may be used to investigate the impact of aging and the cellular switch between neurorecovery and neurodegeneration.
Collapse
Affiliation(s)
- Vicki Chrysostomou
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore.
| | - Katharina C Bell
- Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore; EYE-ACP, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Save Sight Institute, Charles Perkins Centre, University of Sydney, Australia
| | - Sze Woei Ng
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Samyuktha Suresh
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Gayathri Karthik
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore
| | - Marion Millet
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Yingying Chung
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore
| | - Jonathan G Crowston
- Centre for Vision Research, Duke-NUS Medical School, 8 College Road, 169857, Singapore; Singapore Eye Research Institute, The Academia, 20 College Road, 169856, Singapore; Save Sight Institute, Charles Perkins Centre, University of Sydney, Australia
| |
Collapse
|
10
|
Afiat BC, Zhao D, Wong VHY, Perera ND, Turner BJ, Nguyen CTO, Bui BV. Age-related deficits in retinal autophagy following intraocular pressure elevation in autophagy reporter mouse model. Neurobiol Aging 2023; 131:74-87. [PMID: 37586253 DOI: 10.1016/j.neurobiolaging.2023.07.009] [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: 01/18/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 08/18/2023]
Abstract
This study quantified age-related changes to retinal autophagy using the CAG-RFP-EGFP-LC3 autophagy reporter mice and considered how aging impacts autophagic responses to acute intraocular pressure (IOP) stress. IOP was elevated to 50 mm Hg for 30 minutes in 3-month-old and 12-month-old CAG-RFP-EGFP-LC3 (n = 7 per age group) and Thy1-YFPh transgenic mice (n = 3 per age group). Compared with younger eyes, older eyes showed diminished basal autophagy in the outer retina, while the inner retina was unaffected. Autophagic flux (red:yellow puncta ratio) was elevated in the inner plexiform layer. Three days following IOP elevation, older eyes showed poorer functional recovery, most notably in ganglion cell responses compared to younger eyes (12 months old: -33.4 ± 5.3% vs. 3 months mice: -13.4 ± 4.5%). This paralleled a reduced capacity to upregulate autophagic puncta volume in the inner retina in older eyes, a response that was seen in younger eyes. Age-related decline in basal and stress-induced autophagy in the retina is associated with greater retinal ganglion cells' susceptibility to IOP elevation.
Collapse
Affiliation(s)
- Brianna C Afiat
- 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
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, Victoria, Australia
| | - Nirma D Perera
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Bradley J Turner
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Christine T O Nguyen
- 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.
| |
Collapse
|
11
|
Girkin CA, Garner MA, Fazio MA, Clark ME, Karuppanan U, Hubbard MG, Bianco G, Hubbard ST, Fortune B, Gross AK. Retinal electrophysiologic response to IOP elevation in living human eyes. Exp Eye Res 2023; 229:109420. [PMID: 36806673 PMCID: PMC11048619 DOI: 10.1016/j.exer.2023.109420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 01/26/2023] [Accepted: 02/15/2023] [Indexed: 02/18/2023]
Abstract
PURPOSE The relationships between intraocular pressure (IOP), ocular perfusion pressure (OPP), retinal perfusion, and retinal electrophysiologic responses have been explored experimentally across several animal models. These studies have demonstrated that elevated IOP reduces OPP, and when this reduction in OPP exceeds the autoregulatory capacity of the retina vasculature, retinal perfusion and electrophysiologic responses are reduced. This study aimed to evaluate these interactions for the first time in the living human eye. METHODS Five eyes from three research-consented brain-dead organ donors underwent optical coherence tomography with angiographic (OCT/A; Spectralis, Heidelberg Engineering) and electroretinographic (ERG, Diagnosys LLC) measurements while IOP was manometrically-elevated stepwise to pressures of 10, 30 and 50 mmHg. Systemic blood pressure (BP) was monitored continuously during testing. Correlation analysis was applied to assess association between ERG and OPP changes. In a single eye, prolonged IOP elevation was induced with viscoelastic injection and serial ERG measurements were obtained. RESULTS Reductions in inner retinal function defined by photopic ERG were observed with elevation in IOP and concomitant reduction in OPP. Reductions, especially in b-wave, and photopic negative response (PhNR) amplitudes and implicit times were significantly correlated with elevation in IOP and reduction in OPP. There were more appreciable changes in perfusion and functional responses in eyes tested while systemic blood pressure was lower. With prolonged IOP elevation, selective loss of the PhNR response was observed. CONCLUSIONS In the living human eye, retinal perfusion and inner retinal function are acutely impacted by elevation of IOP, and this impact is related to systemic BP and OPP. This novel approach provides a viable model to study the autoregulatory responses to IOP elevation in the living human eye.
Collapse
Affiliation(s)
- Christopher A Girkin
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States.
| | - Mary Anne Garner
- Department of Neurobiology, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Massimo A Fazio
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States; Hamilton Glaucoma Center, Shiley Eye Institute, The Viterbi Family Department of Ophthalmology, University of California San Diego, La Jolla, CA, United States
| | - Mark E Clark
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Udayakumar Karuppanan
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Meredith G Hubbard
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States; Department of Neurobiology, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Gianfranco Bianco
- Department of Ophthalmology and Visual Sciences, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| | - Seth T Hubbard
- Department of Neurobiology, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States; Science and Technology Honors Program, The University of Alabama at Birmingham, Birmingham, AL, United States
| | - Brad Fortune
- Devers Eye Institute, Legacy Health, Portland, OR, United States
| | - Alecia K Gross
- Department of Neurobiology, The University of Alabama at Birmingham School of Medicine, Birmingham, AL, United States
| |
Collapse
|
12
|
Garner MA, Strickland RG, Girkin CA, Gross AK. Mechanisms of retinal ganglion cell injury following acute increases in intraocular pressure. FRONTIERS IN OPHTHALMOLOGY 2022; 2:1007103. [PMID: 38983517 PMCID: PMC11182138 DOI: 10.3389/fopht.2022.1007103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/26/2022] [Indexed: 07/11/2024]
Abstract
The maintenance of intraocular pressure (IOP) is critical to preserving the pristine optics required for vision. Disturbances in IOP can directly impact the optic nerve and retina, and inner retinal injury can occur following acute and chronic IOP elevation. There are a variety of animal models that have been developed to study the effects of acute and chronic elevation of IOP on the retina, retinal ganglion cell (RGC) morphology, intracellular signaling, gene expression changes, and survival. Acute IOP models induce injury that allows for the study of RGC response to well characterized injury and potential recovery. This review will focus on the initial impact of acute IOP elevation on RGC injury and recovery as these early responses may be the best targets for potential therapeutic interventions to promote RGC survival in glaucoma.
Collapse
Affiliation(s)
- Mary Anne Garner
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Ryan G. Strickland
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Christopher A. Girkin
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Alecia K. Gross
- Department of Neurobiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| |
Collapse
|
13
|
Choi EY, Kim M, Lee CS, Byeon SH, Kim SS, Lee M. Intermittent Fasting Is Associated With a Decreased Risk of Age-Related Macular Degeneration. Am J Ophthalmol 2022; 243:1-9. [PMID: 35809657 DOI: 10.1016/j.ajo.2022.06.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/15/2022] [Accepted: 06/22/2022] [Indexed: 11/01/2022]
Abstract
PURPOSE To investigate the association between intermittent fasting and age-related macular degeneration (AMD) in the general older adult population. DESIGN A cross-sectional study using a population-based, government-led survey data, Korean National Health and Nutrition Examination Survey (KNHANES). METHODS A total of 4504 individuals aged ≥55 years with comprehensive data including meal frequency and fundus photography were selected using the KNHANES 2015-2018 database. Participants were divided into 2 groups based on breakfast frequency per week; intermittent fasting (nearly 0 time/week) and nonfasting (5-7 times/week) groups. Multiple logistic regression analysis was performed to determine the risk factors for AMD identified by fundus photography. RESULTS AMD was identified in 25.1% of total participants. The intermittent fasting group had a decreased risk of AMD compared with the nonfasting group (adjusted odds ratio [aOR] 0.413, 95% CI 0.203-0.841), especially in individuals with a younger age (<70 years, aOR 0.357, 95% CI 0.153-0.833), obesity (aOR 0.663, 95% CI 0.424-1.037), and urban residence (aOR 0.437, 95% CI 0.248-0.769). Increased age (aOR 1.058, 95% CI 1.041-1.076) and serum high-density lipoprotein levels (aOR 1.011, 95% CI 1.002-1.021) were also independent risk factors for AMD. CONCLUSIONS Using the population-based survey data, we demonstrated that intermittent fasting by skipping breakfast was significantly associated with a reduced risk of AMD in a representative older adult population, especially in individuals with age <70 years, obesity, and urban residence.
Collapse
Affiliation(s)
- Eun Young Choi
- Department of Ophthalmology, Gangnam Severance Hospital, Institute of Vision Research (E.Y.C., M.K.), Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Min Kim
- Department of Ophthalmology, Gangnam Severance Hospital, Institute of Vision Research (E.Y.C., M.K.), Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Christopher Seungkyu Lee
- Department of Ophthalmology, Severance Eye Hospital, Institute of Vision Research (C.S.L., S.H.B., S.S.K.), Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Suk Ho Byeon
- Department of Ophthalmology, Severance Eye Hospital, Institute of Vision Research (C.S.L., S.H.B., S.S.K.), Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sung Soo Kim
- Department of Ophthalmology, Severance Eye Hospital, Institute of Vision Research (C.S.L., S.H.B., S.S.K.), Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Minyoung Lee
- Department of Internal Medicine (M.L.), Yonsei University College of Medicine, Seoul, Republic of Korea; Institute of Endocrine Research (M.L.), Yonsei University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
14
|
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.
Collapse
|
15
|
Abstract
Glaucoma, a progressive age-related optic neuropathy characterized by the death of retinal ganglion cells, is the most common neurodegenerative cause of irreversible blindness worldwide. The therapeutic management of glaucoma, which is limited to lowering intraocular pressure, is still a challenge since visual loss progresses in a significant percentage of treated patients. Restricted dietary regimens have received considerable attention as adjuvant strategy for attenuating or delaying the progression of neurodegenerative diseases. Here we discuss the literature exploring the effects of modified eating patterns on retinal aging and resistance to stressor stimuli.
Collapse
Affiliation(s)
- Rossella Russo
- Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| | - Carlo Nucci
- Ophthalmology Unit, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Annagrazia Adornetto
- Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy
| |
Collapse
|
16
|
Abstract
PURPOSE OF REVIEW This review explores metabolic syndrome (MetS) as a risk factor that accelerates aging in retinal neurons and may contribute to the neurodegeneration seen in glaucomatous optic neuropathy (GON) and age-related macular degeneration (AMD). RECENT FINDINGS Both animal model experiments and epidemiologic studies suggest that metabolic stress may lead to aberrant regulation of a number of cellular pathways that ultimately lead to premature aging of the cell, including those of a neuronal lineage. SUMMARY GON and AMD are each leading causes of irreversible blindness worldwide. Aging is a significant risk factor in the specific retinal neuron loss that is seen with each condition. Though aging at a cellular level is difficult to define, there are many mechanistic modifiers of aging. Metabolic-related stresses induce inflammation, oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, alterations to the unfolded protein response, defects in autophagy, alterations to the microbiome, and deposition of advanced glycation end products that can all hasten the aging process. Due to the number of variables related to metabolic health, defining criteria to enable the study of risk factors at a population level is challenging. MetS is a definable constellation of related metabolic risk factors that includes enlarged waist circumference, dyslipidemia, systemic hypertension, and hyperglycemia. MetS has been associated with both GON and AMD and may contribute to disease onset and/or progression in each disease.
Collapse
|
17
|
Duarte JN. Neuroinflammatory Mechanisms of Mitochondrial Dysfunction and Neurodegeneration in Glaucoma. J Ophthalmol 2021; 2021:4581909. [PMID: 33953963 PMCID: PMC8064803 DOI: 10.1155/2021/4581909] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 06/29/2020] [Accepted: 03/23/2021] [Indexed: 12/13/2022] Open
Abstract
The exact mechanism of retinal ganglion cell loss in the pathogenesis of glaucoma is yet to be understood. Mitochondrial damage-associated molecular patterns (DAMPs) resulting from mitochondrial dysfunction have been linked to Leber's hereditary optic neuropathy and autosomal dominant optic atrophy, as well as to brain neurodegenerative diseases. Recent evidence shows that, in conditions where mitochondria are damaged, a sustained inflammatory response and downstream pathological inflammation may ensue. Mitochondrial damage has been linked to the accumulation of age-related mitochondrial DNA mutations and mitochondrial dysfunction, possibly through aberrant reactive oxygen species production and defective mitophagy. The present review focuses on how mitochondrial dysfunction may overwhelm the ability of neurons and glial cells to adequately maintain homeostasis and how mitochondria-derived DAMPs trigger the immune system and induce neurodegeneration.
Collapse
Affiliation(s)
- Joao N. Duarte
- Neuroinflammation Unit, Biotech Research & Innovation Center, University of Copenhagen, Copenhagen, Denmark
- Department of Ophthalmology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Immunology, Section 7631, Rigshospitalet, Copenhagen, Denmark
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
18
|
Yu H, Zhong H, Li N, Chen K, Chen J, Sun J, Xu L, Wang J, Zhang M, Liu X, Deng L, Huang P, Huang S, Shen X, Zhong Y. Osteopontin activates retinal microglia causing retinal ganglion cells loss via p38 MAPK signaling pathway in glaucoma. FASEB J 2021; 35:e21405. [PMID: 33559950 DOI: 10.1096/fj.202002218r] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/30/2020] [Accepted: 01/15/2021] [Indexed: 02/07/2023]
Abstract
Microglia activation and release of pro-inflammatory cytokines have been closely linked to glaucoma. However, the mechanisms that initiate these pathways remain unclear. Here, we investigated the role of a pro-inflammatory cytokine--osteopontin (OPN), in retinal microglia activation process along with the underlying mechanisms in glaucoma. A rat chronic ocular hypertension (COH) model was established presenting an increase in retinal OPN level and activation of microglia. Primary microglia cells were isolated and cultured under a pressure culture system showing heightened expressions of microglia-derived OPN with changes in inflammatory factors (TNF-α, IL-1β, and IL-6). OPN and OPN neutralizing antibody (Anti-OPN) interventions were both applied systems for comparison, and cross-referenced with OPN knockdown in vitro. JAK/STAT, NF-κB, ERK1/2, and p38 MAPK, recognized as the primary signaling pathways related to microglia activation, were then screened on whether they can facilitate OPN to act on microglia and their impact on specific inhibitors. Thereafter, retrograde labeling of retinal ganglion cells (RGCs) and flash visual evoked potentials (F-VEP) were used to investigate neuron protection in context of each blockade. Results suggest that OPN is able to enhance the proliferation and activation of retinal microglia in experimental glaucoma which may play a role in the glaucomatous optic neuropathy, and contribute to the eventual RGCs loss and vision function impairment. Such effect may be mediated through the regulation of p38 MAPK signaling pathway.
Collapse
Affiliation(s)
- Huan Yu
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Huimin Zhong
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Na Li
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Kaizhe Chen
- Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Junjue Chen
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Jun Sun
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Lili Xu
- Department of Emergency, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Jing Wang
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Mingui Zhang
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Xiaohong Liu
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Lianfu Deng
- Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Ping Huang
- Shanghai Key Laboratory for Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Shouyue Huang
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Xi Shen
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
| | - Yisheng Zhong
- Department of Ophthalmology, Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Shanghai, China
- Department of Ophthalmology, Zhoushan Branch of Ruijin Hospital Affiliated Medical School, Shanghai Jiaotong University, Zhoushan, China
| |
Collapse
|
19
|
Retinal ganglion cell dysfunction in mice following acute intraocular pressure is exacerbated by P2X7 receptor knockout. Sci Rep 2021; 11:4184. [PMID: 33603067 PMCID: PMC7893065 DOI: 10.1038/s41598-021-83669-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 12/22/2020] [Indexed: 12/21/2022] Open
Abstract
There is increasing evidence for the vulnerability of specific retinal ganglion cell (RGC) types in those with glaucoma and in animal models. In addition, the P2X7-receptor (P2X7-R) has been suggested to contribute to RGC death following stimulation and elevated IOP, though its role in RGC dysfunction prior to death has not been examined. Therefore, we examined the effect of an acute, non-ischemic intraocular pressure (IOP) insult (50 mmHg for 30 min) on RGC function in wildtype mice and P2X7-R knockout (P2X7-KO) mice. We examined retinal function using electroretinogram recordings and individual RGC responses using multielectrode arrays, 3 days following acute IOP elevation. Immunohistochemistry was used to examine RGC cell death and P2X7-R expression in several RGC types. Acute intraocular pressure elevation produced pronounced dysfunction in RGCs; whilst other retinal neuronal responses showed lesser changes. Dysfunction at 3 days post-injury was not associated with RGC loss or changes in receptive field size. However, in wildtype animals, OFF-RGCs showed reduced spontaneous and light-elicited activity. In the P2X7-KO, both ON- and OFF-RGC light-elicited responses were reduced. Expression of P2X7-R in wildtype ON-RGC dendrites was higher than in other RGC types. In conclusion, OFF-RGCs were vulnerable to acute IOP elevation and their dysfunction was not rescued by genetic ablation of P2X7-R. Indeed, knockout of P2X7-R also caused ON-RGC dysfunction. These findings aid our understanding of how pressure affects RGC function and suggest treatments targeting the P2X7-R need to be carefully considered.
Collapse
|
20
|
Tribble JR, Hui F, Jöe M, Bell K, Chrysostomou V, Crowston JG, Williams PA. Targeting Diet and Exercise for Neuroprotection and Neurorecovery in Glaucoma. Cells 2021; 10:295. [PMID: 33535578 PMCID: PMC7912764 DOI: 10.3390/cells10020295] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/15/2021] [Accepted: 01/28/2021] [Indexed: 12/11/2022] Open
Abstract
Glaucoma is a leading cause of blindness worldwide. In glaucoma, a progressive dysfunction and death of retinal ganglion cells occurs, eliminating transfer of visual information to the brain. Currently, the only available therapies target the lowering of intraocular pressure, but many patients continue to lose vision. Emerging pre-clinical and clinical evidence suggests that metabolic deficiencies and defects may play an important role in glaucoma pathophysiology. While pre-clinical studies in animal models have begun to mechanistically uncover these metabolic changes, some existing clinical evidence already points to potential benefits in maintaining metabolic fitness. Modifying diet and exercise can be implemented by patients as an adjunct to intraocular pressure lowering, which may be of therapeutic benefit to retinal ganglion cells in glaucoma.
Collapse
Affiliation(s)
- James R. Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; (F.H.); (J.G.C.)
- Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, VIC 3053, Australia
| | - Melissa Jöe
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| | - Katharina Bell
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
| | - Vicki Chrysostomou
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Jonathan G. Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC 3002, Australia; (F.H.); (J.G.C.)
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore 168751, Singapore; (K.B.); (V.C.)
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 171 64 Stockholm, Sweden; (J.R.T.); (M.J.)
| |
Collapse
|
21
|
Dogan S, Cicekdal MB, Ozorhan U, Karabiyik G, Kazan BT, Ekici ID, Yilmaz B, Demirel PB, Coban I, Tuysuz EC, Kuskucu A, Bayrak OF, Cleary MP, Tuna BG. Roles of adiponectin and leptin signaling-related microRNAs in the preventive effects of calorie restriction in mammary tumor development. Appl Physiol Nutr Metab 2021; 46:866-876. [PMID: 33493087 DOI: 10.1139/apnm-2020-1000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calorie restriction (CR) is suggested to prevent the development of mammary tumors (MTs); however, the mechanism remains to be clarified. We aimed to determine the microRNA (miRNA) profile in mice applied to 2 different CR protocols; chronic (CCR) and intermittent (ICR) and follow the MT development. In addition, the roles of miRNAs involved in adiponectin and/or leptin signaling pathways were investigated. Mice were divided into 3 groups: ad-libitum (AL), CCR, or ICR, which comprised 3 weeks of AL feeding followed by 1 week of 60% CR in a cyclic manner. Blood and tissue collection were performed at weeks 10, 17/18, 49/50 and 81/82. Long-term CCR provided better protection compared with ICR for MT development with a delay in the MT occurrence. Adiponectin expression in mammary fat pad were significantly higher in CCR group compared with AL. Using GeneChip Array, 250 of 3195 miRNAs were differentially expressed among the dietary groups. Thirteen of 250 miRNAs were related to adiponectin and/or leptin signaling genes. Results were verified by reverse transcription polymerase chain reaction. Specifically, miR-326-3p, miR-500-3p and miR-129-5p, which are related to adiponectin and/or leptin signaling, may play important roles in the preventive effects of CR in MT development and in ageing. Thus, these miRNAs might be putative biomarkers to target for diagnostic and treatment purposes. Novelty: Type of CR and micro RNA interaction is related to ageing. miR-326-3p, miR-500-3p and miR-129-5p expression levels were differentially expressed in MT development and in ageing. The genes associated with adiponectin and/or leptin signaling pathways are regulated by certain miRNAs in the protective effects of CR.
Collapse
Affiliation(s)
- Soner Dogan
- Department of Medical Biology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Munevver B Cicekdal
- Department of Medical Biology, School of Medicine, Yeditepe University, Istanbul, Turkey.,Faculty of Medicine and Health Sciences, Medical Biology, Ghent University, Ghent, Belgium
| | - Umit Ozorhan
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Goktug Karabiyik
- Department of Biophysics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Busra T Kazan
- Department of Medical Biology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Isin D Ekici
- Department of Pathology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Bayram Yilmaz
- Department of Physiology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Pinar B Demirel
- Department of Medical Biology and Genetics, School of Medicine, Maltepe University, Istanbul, Turkey
| | - Ilker Coban
- Department of Medical Biology, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Emre Can Tuysuz
- Department of Translational Medicine, Lund University, Lund, Sweden
| | - Aysegul Kuskucu
- Department of Genetics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Omer F Bayrak
- Department of Genetics, School of Medicine, Yeditepe University, Istanbul, Turkey
| | - Margot P Cleary
- Hormel Institute Medical Research Center, University of Minnesota, Austin, MN, USA
| | - Bilge G Tuna
- Department of Biophysics, School of Medicine, Yeditepe University, Istanbul, Turkey
| |
Collapse
|
22
|
Tang J, Hui F, Hadoux X, Soares B, Jamieson M, van Wijngaarden P, Coote M, Crowston JG. Short-Term Changes in the Photopic Negative Response Following Intraocular Pressure Lowering in Glaucoma. Invest Ophthalmol Vis Sci 2021; 61:16. [PMID: 32766747 PMCID: PMC7441296 DOI: 10.1167/iovs.61.10.16] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Purpose To evaluate the short-term changes in inner retinal function using the photopic negative response (PhNR) after intraocular pressure (IOP) reduction in glaucoma. Methods Forty-seven participants with glaucoma who were commencing a new or additional IOP-lowering therapy (treatment group) and 39 participants with stable glaucoma (control group) were recruited. IOP, visual field, retinal nerve fiber layer thickness, and electroretinograms (ERGs) were recorded at baseline and at a follow-up visit (3 ± 2 months). An optimized protocol developed for a portable ERG device was used to record the PhNR. The PhNR saturated amplitude (Vmax), Vmax ratio, semi-saturation constant (K), and slope of the Naka–Rushton function were analyzed. Results A significant percentage reduction in IOP was observed in the treatment group (28 ± 3%) compared to the control group (2 ± 3%; P < 0.0001). For PhNR Vmax, there was no significant interaction (F1,83 = 2.099, P = 0.15), but there was a significant difference between the two time points (F1,83 = 5.689, P = 0.019). Post hoc analysis showed a significant difference between baseline and 3 months in the treatment group (mean difference, 1.23 µV; 95% confidence interval [CI], 0.24–2.22) but not in the control group (0.30 µV; 95% CI, 0.78–1.38). K and slope were not significantly different in either group. Improvement beyond test–retest variability was seen in 17% of participants in the treatment group compared to 3% in the control group (P = 0.007, χ2 test). Conclusions The optimized protocol for measuring the PhNR detected short-term improvements in a proportion of participants following IOP reduction, although the majority showed no change.
Collapse
Affiliation(s)
- Jessica Tang
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Flora Hui
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Xavier Hadoux
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | | | | | - Peter van Wijngaarden
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Michael Coote
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Jonathan G Crowston
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Centre for Vision Research, Duke-NUS Medical School, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| |
Collapse
|
23
|
Jabbehdari S, Chen JL, Vajaranant TS. Effect of dietary modification and antioxidant supplementation on intraocular pressure and open-angle glaucoma. Eur J Ophthalmol 2020; 31:1588-1605. [PMID: 33008269 DOI: 10.1177/1120672120960337] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Primary open-angle glaucoma (POAG) is an age-dependent, intraocular pressure (IOP)-related degeneration of the retinal ganglion cells (RGC). At present, IOP is the only modifiable factor that has been identified to prevent glaucomatous vision loss. Though the pathogenesis of glaucomatous optic neuropathy is still not well understood, increasing evidence suggests oxidative stress may contribute to the induction and progression of glaucoma. Furthermore, antioxidant use may be protective against glaucoma through various mechanisms, including reducing IOP, preserving vascular health, and preventing ganglion cell loss. This article provides a comprehensive review of the effect of oxidative stress, diet, and antioxidant therapy on IOP and open-angle glaucoma.
Collapse
Affiliation(s)
- Sayena Jabbehdari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Judy L Chen
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | | |
Collapse
|
24
|
Jabbehdari S, Handa JT. Oxidative stress as a therapeutic target for the prevention and treatment of early age-related macular degeneration. Surv Ophthalmol 2020; 66:423-440. [PMID: 32961209 DOI: 10.1016/j.survophthal.2020.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 09/10/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022]
Abstract
Age-related macular degeneration, the leading cause of irreversible visual loss among older adults in developed countries, is a chronic, multifactorial, and progressive disease with the development of painless, central vision loss. Retinal pigment epithelial cell dysfunction is a core change in age-related macular degeneration that results from aging and the accumulated effects of genetic and environmental factors that, in part, is both caused by and leads to oxidative stress. In this review, we describe the role of oxidative stress, the cytoprotective oxidative stress pathways, and the impact of oxidative stress on critical cellular processes involved in age-related macular degeneration pathobiology. We also offer targeted therapy that may define how antioxidant therapy can either prevent or improve specific stages of age-related macular degeneration.
Collapse
Affiliation(s)
- Sayena Jabbehdari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - James T Handa
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
| |
Collapse
|
25
|
Dietary Patterns, Carbohydrates, and Age-Related Eye Diseases. Nutrients 2020; 12:nu12092862. [PMID: 32962100 PMCID: PMC7551870 DOI: 10.3390/nu12092862] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/16/2020] [Indexed: 12/19/2022] Open
Abstract
Over a third of older adults in the U.S. experience significant vision loss, which decreases independence and is a biomarker of decreased health span. As the global aging population is expanding, it is imperative to uncover strategies to increase health span and reduce the economic burden of this age-related disease. While there are some treatments available for age-related vision loss, such as surgical removal of cataracts, many causes of vision loss, such as dry age-related macular degeneration (AMD), remain poorly understood and no treatments are currently available. Therefore, it is necessary to better understand the factors that contribute to disease progression for age-related vision loss and to uncover methods for disease prevention. One such factor is the effect of diet on ocular diseases. There are many reviews regarding micronutrients and their effect on eye health. Here, we discuss the impact of dietary patterns on the incidence and progression of age-related eye diseases, namely AMD, cataracts, diabetic retinopathy, and glaucoma. Then, we focus on the specific role of dietary carbohydrates, first by outlining the physiological effects of carbohydrates on the body and then how these changes translate into eye and age-related ocular diseases. Finally, we discuss future directions of nutrition research as it relates to aging and vision loss, with a discussion of caloric restriction, intermittent fasting, drug interventions, and emerging randomized clinical trials. This is a rich field with the capacity to improve life quality for millions of people so they may live with clear vision for longer and avoid the high cost of vision-saving surgeries.
Collapse
|
26
|
Chong RS, Busoy JMF, Tan B, Yeo SW, Lee YS, Barathi AV, Crowston JG, Schmetterer L. A Minimally Invasive Experimental Model of Acute Ocular Hypertension with Acute Angle Closure Characteristics. Transl Vis Sci Technol 2020; 9:24. [PMID: 32832230 PMCID: PMC7414621 DOI: 10.1167/tvst.9.7.24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 05/04/2020] [Indexed: 12/21/2022] Open
Abstract
Purpose To describe a minimally invasive experimental model of acute ocular hypertension (OHT) with characteristics of acute angle closure (AAC). Methods Adult C57/Bl6 mice (n = 31) were subjected to OHT in one eye using a modified circumlimbal suture technique that elevated intraocular pressure (IOP) for 30 minutes. Contralateral un-operated eyes served as controls. IOP, anterior segment optical coherence tomography, and fundus fluorescein angiography (FFA) were performed. The positive scotopic threshold response (pSTR) and a-wave and b-wave amplitudes were also evaluated. Retinal tissues were immunostained for the retinal ganglion cell (RGC) marker RBPMS and the glial marker GFAP. Results OHT eyes developed shallower anterior chambers and dilated pupils. FFA showed focal leakage in 32.2% of OHT eyes, but in none of the control eyes. pSTR was significantly reduced at week 1 in OHT eyes compared to control eyes (57.3 ± 7.2 µV vs. 106.9 ± 24.8 µV; P < 0.05), but a- and b-waves were unaffected. GFAP was upregulated in OHT eyes but not in control eyes or eyes that had been sutured without OHT. RGC density was reduced in OHT eyes after 4 weeks (3857 ± 143.8) vs. control eyes (4469 ± 176.0) (P < 0.05). Conclusions Our minimally invasive model resulted in acute OHT with characteristics of AAC in the absence of non-OHT-related neuroinflammatory changes arising from ocular injury alone. Translational Relevance This model provides a valuable approach to studying specific characteristics of a severe blinding disease in an experimental setting. Focal areas of ischemia were demonstrated, consistent with clinical studies of acute angle closure patients elsewhere, which may indicate the need for further research into how this could affect visual outcome in these patients.
Collapse
Affiliation(s)
- Rachel S Chong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore, Singapore.,Agency for Science, Technology and Research, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Joanna M F Busoy
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Bingyao Tan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Sia Wey Yeo
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Ying Shi Lee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
| | - Amutha V Barathi
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Jonathan G Crowston
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore
| | - Leopold Schmetterer
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore, Singapore.,School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.,Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.,SERI-NTU Advanced Ocular Engineering (STANCE), Singapore, Singapore
| |
Collapse
|
27
|
Hui F, Tang J, Williams PA, McGuinness MB, Hadoux X, Casson RJ, Coote M, Trounce IA, Martin KR, Wijngaarden P, Crowston JG. Improvement in inner retinal function in glaucoma with nicotinamide (vitamin
B3
) supplementation: A crossover randomized clinical trial. Clin Exp Ophthalmol 2020; 48:903-914. [DOI: 10.1111/ceo.13818] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/08/2020] [Accepted: 06/28/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Jessica Tang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision St. Erik Eye Hospital, Karolinska Institutet Stockholm Sweden
| | - Myra B. McGuinness
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Robert J. Casson
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences University of Adelaide Adelaide Australia
| | - Michael Coote
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Ian A. Trounce
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Keith R. Martin
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
- Department of Clinical Neurosciences University of Cambridge Cambridge UK
| | - Peter Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Jonathan G. Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
- Centre for Vision Research Duke‐NUS Medical School Singapore Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre Singapore Singapore
| |
Collapse
|
28
|
Ramírez AI, Fernández-Albarral JA, Hoz RD, López-Cuenca I, Salobrar-García E, Rojas P, Valiente-Soriano FJ, Avilés-Trigueros M, Villegas-Pérez MP, Vidal-Sanz M, Triviño A, Salazar JJ, Ramírez JM. Microglial changes in the early aging stage in a healthy retina and an experimental glaucoma model. PROGRESS IN BRAIN RESEARCH 2020; 256:125-149. [PMID: 32958210 DOI: 10.1016/bs.pbr.2020.05.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glaucoma is an age-related neurodegenerative disease that begins at the onset of aging. In this disease, there is an involvement of the immune system and therefore of the microglia. The purpose of this study is to evaluate the microglial activation using a mouse model of ocular hypertension (OHT) at the onset of aging. For this purpose, we used both naive and ocular hypertensives of 15-month-old mice (early stage of aging). In the latter, we analyzed the OHT eyes and the eyes contralateral to them to compare them with their aged controls. In the eyes of aged naive, aged OHT and aged contralateral eyes, microglial changes were observed compared to the young mice, including: (i) aged naive vs young naive: An increased soma size and vertical processes; (ii) aged OHT eyes vs young OHT eyes: A decrease in the area of the retina occupied by Iba-1 cells and in vertical processes; and (iii) aged contralateral vs young contralateral: A decrease in the soma size and arbor area and an increase in the number of microglia in the outer segment layer. Aged OHT eyes and the eyes contralateral to them showed an up-regulation of the CD68 expression in the branched microglia and a down-regulation in the MHCII and P2RY12 expression with respect to the eyes of young OHT mice. Conclusion: in the early phase of aging, morphological microglial changes along with changes in the expression of MHCII, CD68 and P2RY12, in both naive and OHT mice. These changes appear in aged OHT eyes and the eyes contralateral to them eyes.
Collapse
Affiliation(s)
- Ana I Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Óptica y Optometría, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Madrid, Spain
| | - José A Fernández-Albarral
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain
| | - Rosa de Hoz
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Óptica y Optometría, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Madrid, Spain
| | - Inés López-Cuenca
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain
| | - Elena Salobrar-García
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Óptica y Optometría, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Madrid, Spain
| | - Pilar Rojas
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Hospital General Universitario Gregorio Marañón, Instituto Oftálmico de Madrid, Madrid, Spain
| | - Francisco Javier Valiente-Soriano
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Marcelino Avilés-Trigueros
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - María Paz Villegas-Pérez
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Manuel Vidal-Sanz
- Department of Ophthalmology, University of Murcia and Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca), Murcia, Spain
| | - Alberto Triviño
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Medicina, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Spain
| | - Juan J Salazar
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Óptica y Optometría, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Madrid, Spain.
| | - José M Ramírez
- Instituto de Investigaciones Oftalmológicas Ramón Castroviejo, Universidad Complutense de Madrid, Madrid, Spain; Facultad de Medicina, Departamento de Inmunología, Oftalmología y ORL, Universidad Complutense de Madrid, Spain.
| |
Collapse
|
29
|
Kezic JM, Chrysostomou V, McMenamin PG, Crowston JG. Effects of age on retinal macrophage responses to acute elevation of intraocular pressure. Exp Eye Res 2020; 193:107995. [PMID: 32156653 DOI: 10.1016/j.exer.2020.107995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/17/2020] [Accepted: 03/05/2020] [Indexed: 11/25/2022]
Abstract
There is accumulating evidence that aging shifts the central nervous system milieu towards a proinflammatory state, with increased reactivity of microglia in the aging eye and brain having been implicated in the development of age-related neurodegenerative conditions. Indeed, alterations to microglial morphology and function have been recognized as a part of normal aging. Here, we sought to assess the effects of age on the retinal microglial and macrophage response to acute intraocular pressure (IOP) elevation. Further, we performed experiments whereby bone marrow from young or middle-aged mice was used to reconstitute the bone marrow of whole-body irradiated 12 month old mice. Bone marrow chimeric mice then underwent cannulation and IOP elevation 8 weeks after whole-body irradiation and bone marrow transplantation in order to determine whether the age of bone marrow alters the macrophage response to retinal injury. Our data show retinal macrophage reactivity and microglial morphological changes were enhanced in older mice when compared to younger mice in response to injury. When IOP elevation was performed after whole-body irradiation and bone marrow rescue, we noted subretinal macrophage accumulation and glial reactivity was reduced compared to non-irradiated mice that had also undergone IOP elevation. This effect was evident in both groups of chimeric mice that had received either young or middle-aged bone marrow, suggesting irradiation itself may alter the macrophage and glial response to injury rather than the age of bone marrow.
Collapse
Affiliation(s)
- Jelena M Kezic
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne, Victoria, 3002, Australia; Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia.
| | - Vicki Chrysostomou
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne, Victoria, 3002, Australia.
| | - Paul G McMenamin
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia.
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne, Victoria, 3002, Australia.
| |
Collapse
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Khatib TZ, Martin KR. Neuroprotection in Glaucoma: Towards Clinical Trials and Precision Medicine. Curr Eye Res 2019; 45:327-338. [PMID: 31475591 DOI: 10.1080/02713683.2019.1663385] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Purpose: The eye is currently at the forefront of translational medicine and therapeutics. However, despite advances in technology, primary open-angle glaucoma remains the leading cause of irreversible blindness worldwide. Traditional intraocular pressure (IOP)-lowering therapies are often not sufficient to prevent progression to blindness, even in patients with access to high-quality healthcare. Neuroprotection strategies, which aim to boost the ability of target cells to withstand a pathological insult, have shown significant promise in animal models but none have shown clinically relevant efficacy in human clinical trials to date. We sought to evaluate the current status of neuroprotection clinical trials for glaucoma and identify limitations which have prevented translation of new glaucoma therapies to date.Methods: Literature searches identified English language references. Sources included MEDLINE, EMBASE, the Cochrane Library and Web of Science databases; reference lists of retrieved studies; and internet pages of relevant organisations, meetings and conference proceedings, and clinical trial registries.Results: We discuss six key neuroprotective strategies for glaucoma that have reached the clinical trial stage. Delivery of neurotrophic factors through gene therapy is also progressing towards glaucoma clinical trials. Refinements in trial design and the use of new modalities to define structural and functional endpoints may improve our assessment of disease activity and treatment efficacy. Advances in our understanding of compartmentalised glaucomatous degeneration and continued progress in the molecular profiling of glaucoma patients will enable us to predict individual risk and tailor treatment.Conclusion: New approaches to future glaucoma neuroprotection trials could improve the prospects for new glaucoma therapies. Glaucoma treatment tailored according to an individual's unique risk profile may become increasingly common in the future.
Collapse
Affiliation(s)
- Tasneem Z Khatib
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Eye Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Medical Sciences Division, University of Oxford, Oxford, UK
| | - Keith R Martin
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Eye Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK.,Cambridge NIHR Biomedical Research Centre, Cambridge, UK.,Wellcome Trust - 5 MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| |
Collapse
|
32
|
Iwamura H, Kondo K, Kikuta S, Nishijima H, Kagoya R, Suzukawa K, Ando M, Fujimoto C, Toma-Hirano M, Yamasoba T. Caloric restriction reduces basal cell proliferation and results in the deterioration of neuroepithelial regeneration following olfactotoxic mucosal damage in mouse olfactory mucosa. Cell Tissue Res 2019; 378:175-193. [PMID: 31168693 DOI: 10.1007/s00441-019-03047-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 05/10/2019] [Indexed: 01/18/2023]
Abstract
The effects of caloric restriction (CR) on cell dynamics and gene expression in the mouse olfactory neuroepithelium are evaluated. Eight-week-old male C57BL/6 mice were fed either control pellets (104 kcal/week) or CR pellets (67 kcal/week). The cytoarchitecture of the olfactory neuroepithelium in the uninjured condition and its regeneration after injury by an olfactotoxic chemical, methimazole, were compared between mice fed with the control and CR diets. In the uninjured condition, there were significantly fewer olfactory marker protein (OMP)-positive olfactory receptor neurons and Ki67-positive proliferating basal cells at 3 months in the CR group than in the control group. The number of Ki67-positive basal cells increased after methimazole-induced mucosal injury in both the control and the CR groups, but the increase was less robust in the CR group. The recovery of the neuroepithelium at 2 months after methimazole administration was less complete in the CR group than in the control group. These histological changes were region-specific. The decrease in the OMP-positive neurons was prominent in the anterior region of the olfactory mucosa. Gene expression analysis using a DNA microarray and quantitative real-time polymerase chain reaction demonstrated that the expression levels of two inflammatory cytokines, interleukin-6 and chemokine ligand 1, were elevated in the olfactory mucosa of the CR group compared with the control group. These findings suggest that CR may be disadvantageous to the maintenance of the olfactory neuroepithelium, especially when it is injured.
Collapse
Affiliation(s)
- Hitoshi Iwamura
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Kenji Kondo
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
| | - Shu Kikuta
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Hironobu Nishijima
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Ryoji Kagoya
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Keigo Suzukawa
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Mizuo Ando
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Chisato Fujimoto
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Makiko Toma-Hirano
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Tatsuya Yamasoba
- Department of Otolaryngology-Head and Neck Surgery, The University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| |
Collapse
|
33
|
Comparative localization of cystathionine beta synthases and cystathionine gamma lyase in canine, non-human primate and human retina. Exp Eye Res 2019; 181:72-84. [PMID: 30653965 DOI: 10.1016/j.exer.2019.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/18/2018] [Accepted: 01/03/2019] [Indexed: 12/15/2022]
Abstract
Chronic exposure of the retina to light and high concentrations of polyunsaturated fatty acid in photoreceptor cells make this tissue susceptible to oxidative damage. As retinal degenerative diseases are associated with photoreceptor degeneration, the antioxidant activity of both hydrogen sulfide (H2S) and glutathione (GSH) may play an important role in ameliorating disease progression. H2S production is driven by cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS), the key enzymes that also drive transsulfuration pathway (TSP) necessary for GSH production. As it is currently unclear whether localized production of either H2S or GSH contributes to retinal homeostasis, we undertook a comparative analysis of CBS and CSE expression in canine, non-human primate (NHP) and human retinas to determine if these antioxidants could play a regulatory role in age-related or disease-associated retinal degeneration. Retinas from normal dogs, NHPs and humans were used for the study. Laser capture microdissection (LCM) was performed to isolate individual layers of the canine retina and analyze CBS and CSE gene expression by qRT-PCR. Immunohistochemistry and western blotting were performed for CBS and CSE labeling and protein expression in dog, NHP, and human retina, respectively. Using qRT-PCR, western blot, and immunohistochemistry (IHC), we showed that CBS and CSE are expressed in the canine, NHP, and human retina. IHC results from canine retina demonstrated increased expression levels of CBS but not CSE with post-developmental aging. IHC results also showed non-overlapping localization of both proteins with CBS presenting in rods, amacrine, horizontal, and nerve fiber cell layers while CSE was expressed by RPE, cones and Mϋller cells. Finally, we demonstrated that these enzymes localized to all three layers of canine, NHP and human retina: photoreceptors, outer plexiform layer (OPL) and notably in the ganglion cells layer/nerve fiber layer (GCL/NFL). QRT-PCR performed using RNA extracted from tissues isolated from these cell layers using laser capture microdissection (LCM) confirmed that each of CBS and CSE are expressed equally in these three layers. Together, these findings reveal that CSE and CBS are expressed in the retina, thereby supporting further studies to determine the role of H2S and these proteins in oxidative stress and apoptosis in retinal degenerative diseases.
Collapse
|
34
|
Stone J, Mitrofanis J, Johnstone DM, Falsini B, Bisti S, Adam P, Nuevo AB, George-Weinstein M, Mason R, Eells J. Acquired Resilience: An Evolved System of Tissue Protection in Mammals. Dose Response 2018; 16:1559325818803428. [PMID: 30627064 PMCID: PMC6311597 DOI: 10.1177/1559325818803428] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/22/2018] [Accepted: 08/29/2018] [Indexed: 12/11/2022] Open
Abstract
This review brings together observations on the stress-induced regulation of resilience mechanisms in body tissues. It is argued that the stresses that induce tissue resilience in mammals arise from everyday sources: sunlight, food, lack of food, hypoxia and physical stresses. At low levels, these stresses induce an organised protective response in probably all tissues; and, at some higher level, cause tissue destruction. This pattern of response to stress is well known to toxicologists, who have termed it hormesis. The phenotypes of resilience are diverse and reports of stress-induced resilience are to be found in journals of neuroscience, sports medicine, cancer, healthy ageing, dementia, parkinsonism, ophthalmology and more. This diversity makes the proposing of a general concept of induced resilience a significant task, which this review attempts. We suggest that a system of stress-induced tissue resilience has evolved to enhance the survival of animals. By analogy with acquired immunity, we term this system 'acquired resilience'. Evidence is reviewed that acquired resilience, like acquired immunity, fades with age. This fading is, we suggest, a major component of ageing. Understanding of acquired resilience may, we argue, open pathways for the maintenance of good health in the later decades of human life.
Collapse
Affiliation(s)
- Jonathan Stone
- Discipline of Physiology, Bosch Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - John Mitrofanis
- Discipline of Anatomy and Histology, Bosch Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - Daniel M. Johnstone
- Discipline of Physiology, Bosch Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - Benedetto Falsini
- Facolta’ di Medicina e Chirurgia, Fondazione Policlinico A. Gemelli, Universita’ Cattolica del S. Cuore, Rome, Italy
| | - Silvia Bisti
- Department of Biotechnical and Applied Clinical Sciences, Università degli Studi dell’Aquila, IIT Istituto Italiano di Tecnologia Genova and INBB Istituto Nazionale Biosistemi e Biostrutture, Rome, Italy
| | - Paul Adam
- School of Biological, Earth and Environmental Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Arturo Bravo Nuevo
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA
| | - Mindy George-Weinstein
- Department of Biomedical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA
| | - Rebecca Mason
- Discipline of Physiology, Bosch Institute of Medical Research, University of Sydney, Sydney, New South Wales, Australia
| | - Janis Eells
- College of Health Sciences, University of Wisconsin, Milwaukee, WI, USA
| |
Collapse
|
35
|
Corso-Díaz X, Jaeger C, Chaitankar V, Swaroop A. Epigenetic control of gene regulation during development and disease: A view from the retina. Prog Retin Eye Res 2018; 65:1-27. [PMID: 29544768 PMCID: PMC6054546 DOI: 10.1016/j.preteyeres.2018.03.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 02/01/2018] [Accepted: 03/08/2018] [Indexed: 12/20/2022]
Abstract
Complex biological processes, such as organogenesis and homeostasis, are stringently regulated by genetic programs that are fine-tuned by epigenetic factors to establish cell fates and/or to respond to the microenvironment. Gene regulatory networks that guide cell differentiation and function are modulated and stabilized by modifications to DNA, RNA and proteins. In this review, we focus on two key epigenetic changes - DNA methylation and histone modifications - and discuss their contribution to retinal development, aging and disease, especially in the context of age-related macular degeneration (AMD) and diabetic retinopathy. We highlight less-studied roles of DNA methylation and provide the RNA expression profiles of epigenetic enzymes in human and mouse retina in comparison to other tissues. We also review computational tools and emergent technologies to profile, analyze and integrate epigenetic information. We suggest implementation of editing tools and single-cell technologies to trace and perturb the epigenome for delineating its role in transcriptional regulation. Finally, we present our thoughts on exciting avenues for exploring epigenome in retinal metabolism, disease modeling, and regeneration.
Collapse
Affiliation(s)
- Ximena Corso-Díaz
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Catherine Jaeger
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Vijender Chaitankar
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
36
|
Zhao D, Nguyen CTO, He Z, Wong VHY, van Koeverden AK, Vingrys AJ, Bui BV. Age-related changes in the response of retinal structure, function and blood flow to pressure modification in rats. Sci Rep 2018; 8:2947. [PMID: 29440700 PMCID: PMC5811482 DOI: 10.1038/s41598-018-21203-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/29/2018] [Indexed: 12/11/2022] Open
Abstract
Age-related changes to the balance between the pressure inside the eye (intraocular pressure, IOP) and the pressure inside the brain (intracranial pressure, ICP) can modify the risk of glaucoma. In this study, we consider whether the optic nerve in older rat eyes is more susceptible to acute IOP and ICP modification. We systematically manipulate both ICP and IOP and quantify their effects on ganglion cell function (electroretinography, ERG), optic nerve structure (optical coherence tomography, OCT) and retinal blood flow (Doppler OCT). We show that ganglion cell function in older eyes was more susceptible to a higher optic nerve pressure difference (ONPD = IOP - ICP). This age-related susceptibility could not be explained by poorer blood flow with elevated ONPD. Rather, as ONPD increased the retinal nerve fibre layer showed greater compression, and the retinal surface showed less deformation in older eyes. Our data suggest that age-related changes to connective tissues in and around the rat optic nerve make it less flexible, which may result in greater strain on ganglion cell axons. This may account for greater functional susceptibility to higher optic nerve pressure differences in older rat eyes. Further studies in a species with a well-developed lamina cribrosa are needed to determine the clinical importance of these observations.
Collapse
Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Anna K van Koeverden
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Parkville, 3010, Victoria, Australia.
| |
Collapse
|
37
|
Izuta Y, Imada T, Hisamura R, Oonishi E, Nakamura S, Inagaki E, Ito M, Soga T, Tsubota K. Ketone body 3-hydroxybutyrate mimics calorie restriction via the Nrf2 activator, fumarate, in the retina. Aging Cell 2018; 17:e12699. [PMID: 29119686 PMCID: PMC5770878 DOI: 10.1111/acel.12699] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 11/29/2022] Open
Abstract
Calorie restriction (CR) being the most robust dietary intervention provides various health benefits. D-3-hydroxybutyrate (3HB), a major physiological ketone, has been proposed as an important endogenous molecule for CR. To investigate the role of 3HB in CR, we investigated potential shared mechanisms underlying increased retinal 3HB induced by CR and exogenously applied 3HB without CR to protect against ischemic retinal degeneration. The repeated elevation of retinal 3HB, with or without CR, suppressed retinal degeneration. Metabolomic analysis showed that the antioxidant pentose phosphate pathway and its limiting enzyme, glucose-6-phosphate dehydrogenase (G6PD), were concomitantly preserved. Importantly, the upregulation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a regulator of G6PD, and elevation of the tricarboxylic acid cycle's Nrf2 activator, fumarate, were also shared. Together, our findings suggest that CR provides retinal antioxidative defense by 3HB through the antioxidant Nrf2 pathway via modification of a tricarboxylic acid cycle intermediate during 3HB metabolism.
Collapse
Affiliation(s)
- Yusuke Izuta
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Toshihiro Imada
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Ryuji Hisamura
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Erina Oonishi
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Shigeru Nakamura
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Emi Inagaki
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| | - Masataka Ito
- Department of Developmental Anatomy and Regenerative BiologyNational Defense Medical CollegeTokorozawaJapan
| | - Tomoyoshi Soga
- Institute for Advanced BiosciencesKeio UniversityTsuruokaJapan
| | - Kazuo Tsubota
- Department of OphthalmologyKeio University School of MedicineTokyoJapan
| |
Collapse
|
38
|
Chrysostomou V, Hatch RJ, Colgan T, Paul JP, van Wijngaarden P, Trounce I, Lopez Sanchez MIG, Bell K, Grus F, Crowston JG. Visuelle Regeneration als Ziel für das Glaukom. Ophthalmologe 2018; 116:14-17. [DOI: 10.1007/s00347-018-0649-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
39
|
Liu HH, Zhang L, Shi M, Chen L, Flanagan JG. Comparison of laser and circumlimbal suture induced elevation of intraocular pressure in albino CD-1 mice. PLoS One 2017; 12:e0189094. [PMID: 29190824 PMCID: PMC5708743 DOI: 10.1371/journal.pone.0189094] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/18/2017] [Indexed: 12/23/2022] Open
Abstract
Animal models of ocular hypertension are important tools for glaucoma studies. Both acute transient models and chronic models of ocular hypertension may be useful to investigate specific aspects of neurodegeneration. In this study, we compare the intraocular pressure (IOP) and inner retinal changes induced by 1) laser photocoagulation of both episcleral veins and limbal vessels and 2) circumlimbal suture in CD-1 mice. The suture group is divided into 3 subgroups depending on the level of the immediate IOP spike (acute > 55 mmHg or chronic < 55 mmHg) and time period of monitoring (7 or 28 days). The laser group is followed for 7 days. IOP data show that it peaks at 5 hours and returns to normal level within 7 days in the laser group. In all suture groups, IOP spikes initially and decreases gradually, but it remains significantly elevated at 7 days. In 7 days, the acute suture model generates rapid loss of retinal nerve fiber layer (RNFL) and retinal ganglion cells (RGCs) when compared to the gradual loss by the chronic suture model, possibly due to retinal ischemia and reperfusion within the first few hours after treatment. The laser model falls between the acute suture and chronic suture models resulting in less RNFL and RGC loss than the acute suture model but significantly more loss than the chronic suture model. These results suggest that when using suture models of IOP elevation, it is critical to take the initial IOP spike into consideration and to choose between the acute and chronic models depending on respective research purposes.
Collapse
Affiliation(s)
- Hsin-Hua Liu
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Liwei Zhang
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Meng Shi
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Lu Chen
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - John G. Flanagan
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| |
Collapse
|
40
|
Chrysostomou V, van Wijngaarden P, Steinberg GR, Crowston JG. A short term high-fat high-sucrose diet in mice impairs optic nerve recovery after injury and this is not reversed by exercise. Exp Eye Res 2017; 162:104-109. [PMID: 28757158 DOI: 10.1016/j.exer.2017.07.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/14/2017] [Accepted: 07/25/2017] [Indexed: 12/09/2022]
Abstract
The aim of the current work was to test whether increased intake of dietary fat and sucrose in mice modifies the response of retinal ganglion cells (RGCs) of the optic nerve to injury, and whether any effects of diet are influenced by physical activity levels. C57BL/6J mice were given a high-fat high-sucrose (HFS) diet for 7 weeks, with or without exposure to regular exercise by swimming (60 min/day, 5 days/week). Injury to RGCs was subsequently induced by acute elevation of intraocular pressure (IOP) and retinas were assessed for function and structure. We report that mice on a HFS diet had similar body mass and blood glucose levels compared to mice on a control diet but suffered a 30% greater loss of RGC function following injury, as measured in vivo with the electroretinogram. RGC dysfunction in retinas from mice on the HFS diet was accompanied by activation of retinal macroglia but was not associated with neuronal cell loss. Exercising mice by swimming did not prevent HFS-induced RGC dysfunction in response to injury. This study shows for the first time that a short term increase in dietary fat and sucrose enhances the vulnerability of RGCs to dysfunction and cell stress after an acute injury, and that this is independent of obesity or hyperglycemia. Furthermore, our results suggest that detrimental effects of diet predominate over protective effects of exercise.
Collapse
Affiliation(s)
- Vicki Chrysostomou
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne VIC 3002, Australia; Ophthalmology, University of Melbourne, Department of Surgery, 32 Gisborne Street, East Melbourne VIC 3002, Australia.
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne VIC 3002, Australia; Ophthalmology, University of Melbourne, Department of Surgery, 32 Gisborne Street, East Melbourne VIC 3002, Australia
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, HSC 4N63, 1280 Main St. W. Hamilton, Ontario L8K 4P1, Canada
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, 32 Gisborne Street, East Melbourne VIC 3002, Australia; Ophthalmology, University of Melbourne, Department of Surgery, 32 Gisborne Street, East Melbourne VIC 3002, Australia
| |
Collapse
|
41
|
Zhao D, Nguyen CTO, Wong VHY, Lim JKH, He Z, Jobling AI, Fletcher EL, Chinnery HR, Vingrys AJ, Bui BV. Characterization of the Circumlimbal Suture Model of Chronic IOP Elevation in Mice and Assessment of Changes in Gene Expression of Stretch Sensitive Channels. Front Neurosci 2017; 11:41. [PMID: 28239332 PMCID: PMC5301305 DOI: 10.3389/fnins.2017.00041] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 01/19/2017] [Indexed: 12/30/2022] Open
Abstract
To consider whether a circumlimbal suture can be used to chronically elevate intraocular pressure (IOP) in mice and to assess its effect on retinal structure, function and gene expression of stretch sensitive channels. Anesthetized adult C57BL6/J mice had a circumlimbal suture (10/0) applied around the equator of one eye. In treated eyes (n = 23) the suture was left in place for 12 weeks whilst in sham control eyes the suture was removed at day two (n = 17). Contralateral eyes served as untreated controls. IOP was measured after surgery and once a week thereafter. After 12 weeks, electroretinography (ERG) was performed to assess photoreceptor, bipolar cell and retinal ganglion cell (RGC) function. Retinal structure was evaluated using optical coherence tomography. Retinae were processed for counts of ganglion cell density or for quantitative RT-PCR to quantify purinergic (P2x7, Adora3, Entpd1) or stretch sensitive channel (Panx1, Trpv4) gene expression. Immediately after suture application, IOP spiked to 33 ± 3 mmHg. After 1 day, IOP had recovered to 27 ± 3 mmHg. Between weeks 2 and 12, IOP remained elevated above baseline (control 14 ± 1 mmHg, ocular hypertensive 19 ± 1 mmHg). Suture removal at day 2 (Sham) restored IOP to baseline levels, where it remained through to week 12. ERG analysis showed that 12 weeks of IOP elevation reduced photoreceptor (−15 ± 4%), bipolar cell (−15 ± 4%) and ganglion cell responses (−19 ± 6%) compared to sham controls and respective contralateral eyes (untreated). The retinal nerve fiber layer was thinned in the presence of normal total retinal thickness. Ganglion cell density was reduced across all quadrants (superior −12 ± 5%; temporal, −7% ± 2%; inferior −9 ± 4%; nasal −8 ± 5%). Quantitative RT-PCR revealed a significant increase in Entpd1 gene expression (+11 ± 4%), whilst other genes were not significantly altered (P2x7, Adora3, Trpv4, Panx1). Our results show that circumlimbal ligation produces mild chronic ocular hypertension and retinal dysfunction in mice. Consistent with a sustained change to purinergic signaling we found an up-regulation of Entpd1.
Collapse
Affiliation(s)
- Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Andrew I Jobling
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Erica L Fletcher
- Department of Anatomy and Neuroscience, University of Melbourne Parkville, VIC, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne Parkville, VIC, Australia
| |
Collapse
|
42
|
Targeting retinal ganglion cell recovery. Eye (Lond) 2017; 31:196-198. [PMID: 28060359 DOI: 10.1038/eye.2016.281] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 10/30/2016] [Indexed: 11/08/2022] Open
Abstract
Accumulating evidence from experimental and clinical studies suggest that retinal ganglion cells at least in the earlier stages of glaucoma have the capacity to recover function following periods of functional loss. The capacity for recovery may be negatively impacted by advancing age but can be boosted by interventions such as diet restriction and exercise.
Collapse
|
43
|
Chrysostomou V, Galic S, Wijngaarden P, Trounce IA, Steinberg GR, Crowston JG. Exercise reverses age-related vulnerability of the retina to injury by preventing complement-mediated synapse elimination via a BDNF-dependent pathway. Aging Cell 2016; 15:1082-1091. [PMID: 27613664 PMCID: PMC5114604 DOI: 10.1111/acel.12512] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2016] [Indexed: 01/08/2023] Open
Abstract
Retinal ganglion cells (RGCs) become increasingly vulnerable to injury with advancing age. We recently showed that this vulnerability can be strongly modified in mice by exercise. However, the characteristics and underlying mechanisms of retinal protection with exercise remain unknown. Hence, the aim of this study was to investigate cellular changes associated with exercise‐induced protection of aging retinal cells and the role of local and peripheral trophic signalling in mediating these effects. We focussed on two molecules that are thought to play key roles in mediating beneficial effects of exercise: brain‐derived neurotrophic factor (BDNF) and AMP‐activated protein kinase (AMPK). In middle‐aged (12 months old) C57BL/6J mice, we found that exercise protected RGCs against dysfunction and cell loss after an acute injury induced by elevation of intra‐ocular pressure. This was associated with preservation of inner retinal synapses and reduced synaptic complement deposition. Retinal expression of BDNF was not upregulated in response to exercise alone. Rather, exercise maintained BDNF levels in the retina, which were decreased postinjury in nonexercised animals. Confirming a critical role for BDNF, we found that blocking BDNF signalling during exercise by pharmacological means or genetic knock‐down suppressed the functional protection of RGCs afforded by exercise. Protection of RGCs with exercise was independent of activation of AMPK in either retina or skeletal muscle. Our data support a previously unidentified mechanism in which exercise prevents loss of BDNF in the retina after injury and preserves neuronal function and survival by preventing complement‐mediated elimination of synapses.
Collapse
Affiliation(s)
- Vicki Chrysostomou
- Centre for Eye Research Australia Royal Victorian Eye and Ear Hospital University of Melbourne 32 Gisborne Street East Melbourne Vic. 3002 Australia
| | - Sandra Galic
- St. Vincent's Institute of Medical Research and Department of Medicine University of Melbourne 41 Victoria Parade Fitzroy Vic. 3065 Australia
| | - Peter Wijngaarden
- Centre for Eye Research Australia Royal Victorian Eye and Ear Hospital University of Melbourne 32 Gisborne Street East Melbourne Vic. 3002 Australia
| | - Ian A. Trounce
- Centre for Eye Research Australia Royal Victorian Eye and Ear Hospital University of Melbourne 32 Gisborne Street East Melbourne Vic. 3002 Australia
| | - Gregory R. Steinberg
- Division of Endocrinology and Metabolism Department of Medicine McMaster University 1280 Main Street West Hamilton ON L8S 4L8 Canada
- Department of Biochemistry and Biomedical Sciences McMaster University 1280 Main Street West Hamilton ON L8S 4L8 Canada
| | - Jonathan G. Crowston
- Centre for Eye Research Australia Royal Victorian Eye and Ear Hospital University of Melbourne 32 Gisborne Street East Melbourne Vic. 3002 Australia
| |
Collapse
|
44
|
Liu H, He Z, Nguyen CTO, Vingrys AJ, Bui BV. Reversal of functional loss in a rat model of chronic intraocular pressure elevation. Ophthalmic Physiol Opt 2016; 37:71-81. [DOI: 10.1111/opo.12331] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/17/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Hsin‐Hua Liu
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | - Zheng He
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | | | - Algis J. Vingrys
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| | - Bang V. Bui
- Department of Optometry & Vision Sciences University of Melbourne Parkville Australia
| |
Collapse
|
45
|
Khawaja AP, Cooke Bailey JN, Kang JH, Allingham RR, Hauser MA, Brilliant M, Budenz DL, Christen WG, Fingert J, Gaasterland D, Gaasterland T, Kraft P, Lee RK, Lichter PR, Liu Y, Medeiros F, Moroi SE, Richards JE, Realini T, Ritch R, Schuman JS, Scott WK, Singh K, Sit AJ, Vollrath D, Wollstein G, Zack DJ, Zhang K, Pericak-Vance M, Weinreb RN, Haines JL, Pasquale LR, Wiggs JL. Assessing the Association of Mitochondrial Genetic Variation With Primary Open-Angle Glaucoma Using Gene-Set Analyses. Invest Ophthalmol Vis Sci 2016; 57:5046-5052. [PMID: 27661856 PMCID: PMC5040191 DOI: 10.1167/iovs.16-20017] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
PURPOSE Recent studies indicate that mitochondrial proteins may contribute to the pathogenesis of primary open-angle glaucoma (POAG). In this study, we examined the association between POAG and common variations in gene-encoding mitochondrial proteins. METHODS We examined genetic data from 3430 POAG cases and 3108 controls derived from the combination of the GLAUGEN and NEIGHBOR studies. We constructed biological-system coherent mitochondrial nuclear-encoded protein gene-sets by intersecting the MitoCarta database with the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. We examined the mitochondrial gene-sets for association with POAG and with normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) subsets using Pathway Analysis by Randomization Incorporating Structure. RESULTS We identified 22 KEGG pathways with significant mitochondrial protein-encoding gene enrichment, belonging to six general biological classes. Among the pathway classes, mitochondrial lipid metabolism was associated with POAG overall (P = 0.013) and with NTG (P = 0.0006), and mitochondrial carbohydrate metabolism was associated with NTG (P = 0.030). Examining the individual KEGG pathway mitochondrial gene-sets, fatty acid elongation and synthesis and degradation of ketone bodies, both lipid metabolism pathways, were significantly associated with POAG (P = 0.005 and P = 0.002, respectively) and NTG (P = 0.0004 and P < 0.0001, respectively). Butanoate metabolism, a carbohydrate metabolism pathway, was significantly associated with POAG (P = 0.004), NTG (P = 0.001), and HTG (P = 0.010). CONCLUSIONS We present an effective approach for assessing the contributions of mitochondrial genetic variation to open-angle glaucoma. Our findings support a role for mitochondria in POAG pathogenesis and specifically point to lipid and carbohydrate metabolism pathways as being important.
Collapse
Affiliation(s)
- Anthony P. Khawaja
- National Institute for Health Research (NIHR) Biomedical Research Centre, Moorfields Eye Hospital National Health Service (NHS) Foundation Trust, and University College London (UCL) Institute of Ophthalmology, London, United Kingdom
| | - Jessica N. Cooke Bailey
- Department of Epidemiology and Biostatistics, Institute for Computational Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Jae Hee Kang
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - R. Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
| | - Michael A. Hauser
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, United States
- Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States
| | - Murray Brilliant
- Marshfield Clinic Research Foundation, Marshfield, Wisconsin, United States
| | - Donald L. Budenz
- Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina, United States
| | - William G. Christen
- Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - John Fingert
- Department of Ophthalmology, University of Iowa, College of Medicine, Iowa City, Iowa, United States
- Stephen A. Wynn Institute for Vision Research, Iowa City, Iowa, United States
| | | | - Terry Gaasterland
- Scripps Genome Center, University of California at San Diego, San Diego, California, United States
| | - Peter Kraft
- Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States
- Program in Genetic Epidemiology and Statistical Genetics, Harvard School of Public Health, Boston, Massachusetts, United States
| | - Richard K. Lee
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Paul R. Lichter
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Felipe Medeiros
- Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, San Diego, California, United States
| | - Syoko E. Moroi
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
| | - Julia E. Richards
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, United States
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan, United States
| | - Tony Realini
- Department of Ophthalmology, West Virginia University Eye Institute, Morgantown, West Virginia, United States
| | - Robert Ritch
- Einhorn Clinical Research Center, Department of Ophthalmology, New York Eye and Ear Infirmary of Mount Sinai, New York, New York, United States
| | - Joel S. Schuman
- Department of Ophthalmology, New York University, New York, New York, United States
| | - William K. Scott
- Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Kuldev Singh
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, United States
| | - Arthur J. Sit
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Douglas Vollrath
- Department of Genetics, Stanford University School of Medicine, Palo Alto, California, United States
| | - Gadi Wollstein
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Donald J. Zack
- Wilmer Eye Institute, Johns Hopkins University Hospital, Baltimore, Maryland, United States
| | - Kang Zhang
- Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, San Diego, California, United States
| | - Margaret Pericak-Vance
- Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, United States
| | - Robert N. Weinreb
- Hamilton Glaucoma Center, Shiley Eye Institute, University of California, San Diego, San Diego, California, United States
| | - Jonathan L. Haines
- Department of Epidemiology and Biostatistics, Institute for Computational Biology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States
| | - Louis R. Pasquale
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States
| | - Janey L. Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States
| |
Collapse
|
46
|
Mead B, Tomarev S. Evaluating retinal ganglion cell loss and dysfunction. Exp Eye Res 2016; 151:96-106. [PMID: 27523467 DOI: 10.1016/j.exer.2016.08.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 12/16/2022]
Abstract
Retinal ganglion cells (RGC) bear the sole responsibility of propagating visual stimuli to the brain. Their axons, which make up the optic nerve, project from the retina to the brain through the lamina cribrosa and in rodents, decussate almost entirely at the optic chiasm before synapsing at the superior colliculus. For many traumatic and degenerative ocular conditions, the dysfunction and/or loss of RGC is the primary determinant of visual loss and are the measurable endpoints in current research into experimental therapies. To actually measure these endpoints in rodent models, techniques must ascertain both the quantity of surviving RGC and their functional capacity. Quantification techniques include phenotypic markers of RGC, retrogradely transported fluorophores and morphological measurements of retinal thickness whereas functional assessments include electroretinography (flash and pattern) and visual evoked potential. The importance of the accuracy and reliability of these techniques cannot be understated, nor can the relationship between RGC death and dysfunction. The existence of up to 30 types of RGC complicates the measuring process, particularly as these may respond differently to disease and treatment. Since the above techniques may selectively identify and ignore particular subpopulations, their appropriateness as measures of RGC survival and function may be further limited. This review discusses the above techniques in the context of their subtype specificity.
Collapse
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, MD, 20892, USA.
| | - Stanislav Tomarev
- Section of Retinal Ganglion Cell Biology, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| |
Collapse
|
47
|
Nguyen CT, Tsai TI, He Z, Vingrys AJ, Lee PY, Bui BV. Simultaneous Recording of Electroretinography and Visual Evoked Potentials in Anesthetized Rats. J Vis Exp 2016. [PMID: 27404129 DOI: 10.3791/54158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The electroretinogram (ERG) and visual evoked potential (VEP) are commonly used to assess the integrity of the visual pathway. The ERG measures the electrical responses of the retina to light stimulation, while the VEP measures the corresponding functional integrity of the visual pathways from the retina to the primary visual cortex following the same light event. The ERG waveform can be broken down into components that reflect responses from different retinal neuronal and glial cell classes. The early components of the VEP waveform represent the integrity of the optic nerve and higher cortical centers. These recordings can be conducted in isolation or together, depending on the application. The methodology described in this paper allows simultaneous assessment of retinal and cortical visual evoked electrophysiology from both eyes and both hemispheres. This is a useful way to more comprehensively assess retinal function and the upstream effects that changes in retinal function can have on visual evoked cortical function.
Collapse
Affiliation(s)
| | - Tina I Tsai
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Pei Y Lee
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne;
| |
Collapse
|
48
|
Fahy ET, Chrysostomou V, Abbott CJ, van Wijngaarden P, Crowston JG. Axonal transport along retinal ganglion cells is grossly intact during reduced function post-injury. Exp Eye Res 2016; 146:289-292. [PMID: 26965224 DOI: 10.1016/j.exer.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 11/30/2022]
Abstract
It has been established that beyond middle age, mice are slower to recover inner retinal function following an acute intraocular pressure (IOP) injury. While 3 month old animals exhibit near-complete recovery 1 week following injury, 12 and 18 month old animals demonstrate prolonged inner retinal dysfunction. In this study we aim to determine whether age-related differences in functional recovery of the inner retina are due to differences in retinal ganglion cell (RGC) axonal transport. C57BL/6J mice at 3 (n = 8) and 18 months (n = 8) of age were used. At day 0, right eyes were cannulated and the IOP was maintained at 50 mmHg for 30 min. At day 5, mice received bilateral intravitreal injections of choleratoxin subunit B (CTB) conjugated to Alexafluor 488. At day 7, mice were euthanized and tissue was collected. Axonal transport of CTB was quantified in retinas and superior colliculi (SC) using fluorescent microscopy. In response to IOP elevation, the overall degree of axonal transport was comparable between young and old mice. Furthermore, no differences in axonal transport were detected between control eyes and injured in mice at any age. In conclusion, impaired recovery of inner retinal function 1 week following acute IOP injury in old mice is not associated with changes in active axonal transport in RGCs at this time.
Collapse
Affiliation(s)
- E T Fahy
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia
| | - V Chrysostomou
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia
| | - C J Abbott
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia
| | - P van Wijngaarden
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia
| | - J G Crowston
- Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, Victoria, Australia.
| |
Collapse
|
49
|
What is the effect of fasting on the lifespan of neurons? Ageing Res Rev 2015; 24:160-5. [PMID: 26264849 DOI: 10.1016/j.arr.2015.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 07/17/2015] [Accepted: 07/30/2015] [Indexed: 12/14/2022]
Abstract
Medical advancements have increased life expectancy but have consequently increased the incidence of age-related disease. Fasting or dietary restriction (DR) can help prevent these via anti-ageing effects; however, these effects in neurons are less well characterized. Here, a series of animal and human studies of the effects of DR on the structural and functional integrity of neurons and the underlying mechanisms are analyzed. DR improves the integrity of animal neurons via a wide range of possible mechanisms including changes in metabolism, oxidative damage, stress responses, growth factors, and gene expression. These mechanisms are extensively interlinked and point to an optimum range of calorie intake, above calorie deprivation and below burdensome calorie excess. Human studies also suggest that DR improves neuron integrity; however, due to ethical and methodological limitations, the most conclusive data on DR hinge upon on-going life-long monkey experiments. Rather than developing pharmacological mimetics of DR, our focus should be on educating the public about DR in order to minimize age-related disease.
Collapse
|
50
|
Zhi Z, Cepurna W, Johnson E, Jayaram H, Morrison J, Wang RK. Evaluation of the effect of elevated intraocular pressure and reduced ocular perfusion pressure on retinal capillary bed filling and total retinal blood flow in rats by OMAG/OCT. Microvasc Res 2015; 101:86-95. [PMID: 26186381 DOI: 10.1016/j.mvr.2015.07.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 07/04/2015] [Accepted: 07/04/2015] [Indexed: 01/01/2023]
Abstract
PURPOSE To determine if retinal capillary filling is preserved in the face of acutely elevated intraocular pressure (IOP) in anesthetized rats, despite a reduction in total retinal blood flow (RBF), using optical microangiography/optical coherence tomography (OMAG/OCT). METHODS OMAG provided the capability of depth-resolved imaging of the retinal microvasculature down to the capillary level. Doppler OCT was applied to measure the total RBF using an enface integration approach. The microvascular pattern, capillary density, and total RBF were monitored in vivo as the IOP was increased from 10 to 100mmHg in 10mmHg intervals and returned back to 10mmHg. RESULTS In animals with mean arterial pressure (MAP) of 102±4mmHg (n=10), when IOP was increased from 0 to 100mmHg, the capillary density remained at or above 80% of baseline for the IOP up to 60mmHg [or ocular perfusion pressure (OPP) at 40mmHg]. This was then decreased, achieving 60% of baseline at IOP 70mmHg and OPP of 30mmHg. Total RBF was unaffected by moderate increases in IOP up to 30mmHg, beyond which total RBF decreased linearly, reaching 50% of baseline at IOP 60mmHg and OPP 40mmHg. Both capillary density and total RBF were totally extinguished at 100mmHg, but fully recovered when IOP returned to baseline. By comparison, a separate group of animals with lower MAP (mean=75±6mmHg, n=7) demonstrated comparable decreases in both capillary filling and total RBF at IOPs that were 20mmHg lower than in the initial group. Both were totally extinguished at 80mmHg, but fully recovered when IOP returned to baseline. Relationships of both parameters to OPP were unchanged. CONCLUSION Retinal capillary filling and total RBF responses to IOP elevation can be monitored non-invasively by OMAG/OCT and both are influenced by OPP. Retinal capillary filling was relatively preserved down to a perfusion pressure of 40mmHg, despite a linear reduction in total RBF.
Collapse
Affiliation(s)
- Zhongwei Zhi
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - William Cepurna
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Elaine Johnson
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Hari Jayaram
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - John Morrison
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA; Department of Ophthalmology, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|