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Majimbi M, McLenachan S, Nesbit M, Chen FK, Lam V, Mamo J, Takechi R. In vivo retinal imaging is associated with cognitive decline, blood-brain barrier disruption and neuroinflammation in type 2 diabetic mice. Front Endocrinol (Lausanne) 2023; 14:1224418. [PMID: 37850093 PMCID: PMC10577437 DOI: 10.3389/fendo.2023.1224418] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 08/15/2023] [Indexed: 10/19/2023] Open
Abstract
Introduction Type 2 diabetes (T2D) is associated with chronic inflammation and neurovascular changes that lead to functional impairment and atrophy in neural-derived tissue. A reduction in retinal thickness is an early indicator of diabetic retinopathy (DR), with progressive loss of neuroglia corresponding to DR severity. The brain undergoes similar pathophysiological events as the retina, which contribute to T2D-related cognitive decline. Methods This study explored the relationship between retinal thinning and cognitive decline in the LepR db/db model of T2D. Diabetic db/db and non-diabetic db/+ mice aged 14 and 28 weeks underwent cognitive testing in short and long-term memory domains and in vivo retinal imaging using optical coherence tomography (OCT), followed by plasma metabolic measures and ex vivo quantification of neuroinflammation, oxidative stress and microvascular leakage. Results At 28 weeks, mice exhibited retinal thinning in the ganglion cell complex and inner nuclear layer, concomitant with diabetic insulin resistance, memory deficits, increased expression of inflammation markers and cerebrovascular leakage. Interestingly, alterations in retinal thickness at both experimental timepoints were correlated with cognitive decline and elevated immune response in the brain and retina. Discussion These results suggest that changes in retinal thickness quantified with in vivo OCT imaging may be an indicator of diabetic cognitive dysfunction and neuroinflammation.
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Affiliation(s)
- May Majimbi
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - Samuel McLenachan
- Lions Eye Institute Australia, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
| | - Michael Nesbit
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - Fred K. Chen
- Lions Eye Institute Australia, Harry Perkins Institute of Medical Research, Nedlands, WA, Australia
| | - Virginie Lam
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
| | - John Mamo
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
- Perron Institute for Neurological and Translational Research, Nedlands, WA, Australia
| | - Ryu Takechi
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, WA, Australia
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2
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Bucolo C, Barbieri A, Viganò I, Marchesi N, Bandello F, Drago F, Govoni S, Zerbini G, Pascale A. Short-and Long-Term Expression of Vegf: A Temporal Regulation of a Key Factor in Diabetic Retinopathy. Front Pharmacol 2021; 12:707909. [PMID: 34489701 PMCID: PMC8418071 DOI: 10.3389/fphar.2021.707909] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
To investigate the role of vascular endothelial growth factor (VEGF) at different phases of diabetic retinopathy (DR), we assessed the retinal protein expression of VEGF-A164 (corresponding to the VEGF165 isoform present in humans, which is the predominant member implicated in vascular hyperpermeability and proliferation), HIF-1α and PKCβ/HuR pathway in Ins2Akita (diabetic) mice at different ages. We used C57BL6J mice (WT) at different ages as control. Retina status, in terms of tissue morphology and neovascularization, was monitored in vivo at different time points by optical coherence tomography (OCT) and fluorescein angiography (FA), respectively. The results showed that VEGF-A164 protein expression increased along time to become significantly elevated (p < 0.05) at 9 and 46 weeks of age compared to WT mice. The HIF-1α protein level was significantly (p < 0.05) increased at 9 weeks of age, while PKCβII and HuR protein levels were increased at 46 weeks of age compared to WT mice. The thickness of retinal nerve fiber layer as measured by OCT was decreased in Ins2Akita mice at 9 and 46 weeks of age, while no difference in the retinal vasculature were observed by FA. The present findings show that the retina of the diabetic Ins2Akita mice, as expected for mice, does not develop proliferative retinopathy even after 46 weeks. However, diabetic Ins2Akita mice recapitulate the same evolution of patients with DR in terms of both retinal neurodegeneration and pro-angiogenic shift, this latter indicated by the progressive protein expression of the pro-angiogenic isoform VEGF-A164, which can be sustained by the PKCβII/HuR pathway acting at post-transcriptional level. In agreement with this last concept, this rise in VEGF-A164 protein is not paralleled by an increment of the corresponding transcript. Nevertheless, the observed increase in HIF-1α at 9 weeks indicates that this transcription factor may favor, in the early phase of the disease, the transcription of other isoforms, possibly neuroprotective, in the attempt to counteract the neurodegenerative effects of VEGF-A164. The time-dependent VEGF-A164 expression in the retina of diabetic Ins2Akita mice suggests that pharmacological intervention in DR might be chosen, among other reasons, on the basis of the specific stages of the pathology in order to pursue the best clinical outcome.
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Affiliation(s)
- Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Annalisa Barbieri
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Ilaria Viganò
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Nicoletta Marchesi
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS Ospedale San Raffaele, Vita-Salute University, Milan, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
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3
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Uemura A, Fruttiger M, D'Amore PA, De Falco S, Joussen AM, Sennlaub F, Brunck LR, Johnson KT, Lambrou GN, Rittenhouse KD, Langmann T. VEGFR1 signaling in retinal angiogenesis and microinflammation. Prog Retin Eye Res 2021; 84:100954. [PMID: 33640465 PMCID: PMC8385046 DOI: 10.1016/j.preteyeres.2021.100954] [Citation(s) in RCA: 137] [Impact Index Per Article: 45.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 02/12/2021] [Accepted: 02/19/2021] [Indexed: 12/13/2022]
Abstract
Five vascular endothelial growth factor receptor (VEGFR) ligands (VEGF-A, -B, -C, -D, and placental growth factor [PlGF]) constitute the VEGF family. VEGF-A binds VEGF receptors 1 and 2 (VEGFR1/2), whereas VEGF-B and PlGF only bind VEGFR1. Although much research has been conducted on VEGFR2 to elucidate its key role in retinal diseases, recent efforts have shown the importance and involvement of VEGFR1 and its family of ligands in angiogenesis, vascular permeability, and microinflammatory cascades within the retina. Expression of VEGFR1 depends on the microenvironment, is differentially regulated under hypoxic and inflammatory conditions, and it has been detected in retinal and choroidal endothelial cells, pericytes, retinal and choroidal mononuclear phagocytes (including microglia), Müller cells, photoreceptor cells, and the retinal pigment epithelium. Whilst the VEGF-A decoy function of VEGFR1 is well established, consequences of its direct signaling are less clear. VEGFR1 activation can affect vascular permeability and induce macrophage and microglia production of proinflammatory and proangiogenic mediators. However the ability of the VEGFR1 ligands (VEGF-A, PlGF, and VEGF-B) to compete against each other for receptor binding and to heterodimerize complicates our understanding of the relative contribution of VEGFR1 signaling alone toward the pathologic processes seen in diabetic retinopathy, retinal vascular occlusions, retinopathy of prematurity, and age-related macular degeneration. Clinically, anti-VEGF drugs have proven transformational in these pathologies and their impact on modulation of VEGFR1 signaling is still an opportunity-rich field for further research.
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Affiliation(s)
- Akiyoshi Uemura
- Department of Retinal Vascular Biology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan.
| | - Marcus Fruttiger
- UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Patricia A D'Amore
- Schepens Eye Research Institute of Massachusetts Eye and Ear, 20 Staniford Street, Boston, MA, 02114, USA.
| | - Sandro De Falco
- Angiogenesis Laboratory, Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", Via Pietro Castellino 111, 80131 Naples, Italy; ANBITION S.r.l., Via Manzoni 1, 80123, Naples, Italy.
| | - Antonia M Joussen
- Department of Ophthalmology, Charité-Universitätsmedizin Berlin, Hindenburgdamm 30, 12200 Berlin, and Augustenburger Platz 1, 13353, Berlin, Germany.
| | - Florian Sennlaub
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France.
| | - Lynne R Brunck
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Kristian T Johnson
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - George N Lambrou
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Kay D Rittenhouse
- Bayer Consumer Care AG, Pharmaceuticals, Peter-Merian-Strasse 84, CH-4052 Basel, Switzerland.
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Joseph-Stelzmann-Str. 9, 50931, Cologne, Germany.
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4
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Sheskey SR, Antonetti DA, Rentería RC, Lin CM. Correlation of Retinal Structure and Visual Function Assessments in Mouse Diabetes Models. Invest Ophthalmol Vis Sci 2021; 62:20. [PMID: 34410299 PMCID: PMC8383928 DOI: 10.1167/iovs.62.10.20] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Purpose Diabetic retinopathy results in vision loss with changes to both retinal blood vessels and neural retina. Recent studies have revealed that animal models of diabetes demonstrate early loss of visual function. We explored the time course of retinal change in three different mouse models of diabetes in a longitudinal study using in vivo measures of retinal structure (optical coherence tomography [OCT]) and visual function (optomotor and pupillary responses). Methods OCT analysis of retinal microstructure, optokinetic response as a measure of visual acuity, and pupillary response to light stimulation were compared among the db/db, Ins2Akita, and streptozotocin (STZ)-induced mouse models of diabetes at 1.5, 3, 6, and 9 months of diabetes. Results The db/db, Ins2Akita, and STZ-induced models of diabetes all exhibited vision loss and retinal thinning as disease progressed. Both structural changes and functional measures were significantly correlated with the blood glucose levels. Despite this, vision loss and retinal thinning were not consistently correlated, except for the inner retinal layer thickness at 6 months of diabetes. Conclusions This longitudinal study compiled structural measures and functional outcome data for type 1 and 2 diabetes mouse models commonly used for diabetes studies and demonstrated an overall decline in retinal-related health in conjunction with weight change and blood glucose alterations. The relationship between the structural change and functional outcome could be correlative but is not necessarily causative, as retinal thinning was not sufficient to explain visual acuity decline.
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Affiliation(s)
- Sarah R Sheskey
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - René C Rentería
- Department of Clinical and Applied Science Education, School of Osteopathic Medicine, University of the Incarnate Word, San Antonio, Texas, United States
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
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5
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Quiroz J, Yazdanyar A. Animal models of diabetic retinopathy. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1272. [PMID: 34532409 PMCID: PMC8421981 DOI: 10.21037/atm-20-6737] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 12/23/2020] [Indexed: 12/16/2022]
Abstract
The retina is the posterior neuro-integrated layer of the eye that conducts impulses induced by light to the optic nerve for human vision. Diseases of the retina often leads to diminished vision and in some cases blindness. Diabetes mellitus (DM) is a worldwide public health issue and globally, there is an estimated 463 million people that are affected by DM and its consequences. Diabetic retinopathy (DR) is a blinding complication of chronic uncontrolled DM and is the most common cause of blindness in the United States between the ages 24-75. It is estimated that the global prevalence of DR will increase to 191.0 million by 2030, of those 56.3 million possessing vision-threatening diabetic retinopathy (VTDR). For the most part, current treatment modalities control the complications of DR without addressing the underlying pathophysiology of the disease. Therefore, there is an unmet need for new therapeutics that not only repair the damaged retinal tissue, but also reverse the course of DR. The key element in developing these treatments is expanding our basic knowledge by studying DR pathogenesis in animal models of proliferative and non-proliferative DR (PDR and NPDR). There are numerous models available for the research of both PDR and NPDR with substantial overlap. Animal models available include those with genetic backgrounds prone to hyperglycemic states, immunologic etiologies, or environmentally induced disease. In this review we aimed to comprehensively summarize the available animal models for DR while also providing insight to each model's ocular therapeutic potential for drug discovery.
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Affiliation(s)
- Jose Quiroz
- Medical Scientist Training Program, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Amirfarbod Yazdanyar
- Department of Ophthalmology and Visual Sciences, State University of New York (SUNY), Upstate Medical University, Syracuse, NY, USA
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Dellaa A, Mbarek S, Kahloun R, Dogui M, Khairallah M, Hammoum I, Rayana-Chekir NB, Charfeddine R, Lachapelle P, Chaouacha-Chekir RB. Functional alterations of retinal neurons and vascular involvement progress simultaneously in the Psammomys obesus model of diabetic retinopathy. J Comp Neurol 2021; 529:2620-2635. [PMID: 33474721 DOI: 10.1002/cne.25114] [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: 01/31/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 11/11/2022]
Abstract
To investigate the progression of diabetic retinopathy (DR) in a new diurnal animal model, we monitored clinically the DR in Psammomys obesus (P. obesus) during 7 months using electroretinography (ERG) and imaging techniques. After the onset of DR, all ERG components decreased progressively. In scotopic conditions, by 3-months of disease progression, the diabetic P. obesus displayed a significant decrease in amplitude of b-max, b-wave responses, and mixed b-waves. While mixed a-wave decreased between 4 and 7 months. Significant differences of OP2 appeared following 1 month of disease. In photopic conditions, we noticed a decrease in the a-wave at 2 months, while it took more than 5 months in b-wave amplitude. The photopic negative response (PhNR) and the i-wave amplitudes decreased following 4 and 5 months. OP1 and OP2 were the first to be altered and a significant decrease in the amplitude started after 3 months. Finally, 30 Hz-flicker and photopic S-cone were impaired after 2 and 3 months, respectively. The assessment of the eye fundus of the retina revealed an abnormal vascular architecture appeared at Months 6 and 7. In addition, we noticed exudates in the superior periphery of the retina at the same stage. The retina thickness showed a significant reduction at Month 7. Our results indicate that the clinical correlates of human DR are present in diabetic P. obesus. The depressed of ERGs, disruption of retinal architecture, and the appearance of exudates may reflect vascular and neuronal damage throughout the retina as are seen in the advanced stages of human DR.
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Affiliation(s)
- Ahmed Dellaa
- Laboratory of Physiopathology, Food and Biomolecules, Higher Institute of Biotechnology of Sidi Thabet, BiotechPole Sidi Thabet, University of Manouba, Tunisia
| | - Sihem Mbarek
- Laboratory of Physiopathology, Food and Biomolecules, Higher Institute of Biotechnology of Sidi Thabet, BiotechPole Sidi Thabet, University of Manouba, Tunisia
| | - Rim Kahloun
- Department of Ophthalmology, Hospital of Fattouma Bourguiba, Monastir, Tunisia
| | - Mohamed Dogui
- Department of Functional Explorations of the Nervous System, Hospital of Sahloul, Sousse, Tunisia
| | - Moncef Khairallah
- Department of Ophthalmology, Hospital of Fattouma Bourguiba, Monastir, Tunisia
| | - Imane Hammoum
- Laboratory of Physiopathology, Food and Biomolecules, Higher Institute of Biotechnology of Sidi Thabet, BiotechPole Sidi Thabet, University of Manouba, Tunisia
| | - Narjess Ben Rayana-Chekir
- Les Ophtalmologistes Associés de Sousse, Résidence Médicale Essalem, Place du Maghreb Arabe-Sousse, Tunisia
| | | | - Pierre Lachapelle
- Department of Ophthalmology, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Rafika Ben Chaouacha-Chekir
- Laboratory of Physiopathology, Food and Biomolecules, Higher Institute of Biotechnology of Sidi Thabet, BiotechPole Sidi Thabet, University of Manouba, Tunisia
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Mugisho OO, Green CR, Zhang J, Acosta ML, Rupenthal ID. Connexin43 hemichannels: A potential drug target for the treatment of diabetic retinopathy. Drug Discov Today 2019; 24:1627-1636. [PMID: 30690195 DOI: 10.1016/j.drudis.2019.01.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/17/2019] [Accepted: 01/17/2019] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is a chronic vascular disease of the retina that causes vision loss in patients with type 1 and type 2 diabetes, and is associated with vascular dysfunction and occlusion, retinal oedema, haemorrhage and inadequate growth of new blood vessels. Current DR therapies primarily target downstream, later-stage vascular defects with a significant proportion of diabetic macular oedema patients being non-responders. Moreover, other evidence suggests that prolonged use of therapies targeting vascular endothelial growth factor (VEGF) might be associated with increased onset of geographic atrophy and retinal ganglion cell death. It is therefore highly desirable to prevent the onset of DR or arrest its progression at a stage preceding the appearance of more-advanced pathology by targeting upstream disease mechanisms. Connexin43 hemichannels play a part in the pathogenesis of chronic inflammatory diseases, including inflammasome pathway activation; and hemichannel block has been shown to alleviate vascular leak and inflammation. This review discusses the inflammatory changes occurring in DR as well as current therapies and their limitations. It then focuses on the role of connexin43 in DR, providing evidence for the utility of connexin43 hemichannel blockers as novel therapeutics for DR treatment.
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Affiliation(s)
- Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Jie Zhang
- Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Monica L Acosta
- School of Optometry and Vision Science and the New Zealand National Eye Centre, University of Auckland, New Zealand
| | - Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology and the New Zealand National Eye Centre, University of Auckland, New Zealand.
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8
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Mäe MA, Li T, Bertuzzi G, Raschperger E, Vanlandewijck M, He L, Nahar K, Dalheim A, Hofmann JJ, Laviña B, Keller A, Betsholtz C, Genové G. Prolonged systemic hyperglycemia does not cause pericyte loss and permeability at the mouse blood-brain barrier. Sci Rep 2018; 8:17462. [PMID: 30498224 PMCID: PMC6265246 DOI: 10.1038/s41598-018-35576-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/07/2018] [Indexed: 12/12/2022] Open
Abstract
Diabetes mellitus is associated with cognitive impairment and various central nervous system pathologies such as stroke, vascular dementia, or Alzheimer’s disease. The exact pathophysiology of these conditions is poorly understood. Recent reports suggest that hyperglycemia causes cerebral microcirculation pathology and blood-brain barrier (BBB) dysfunction and leakage. The majority of these reports, however, are based on methods including in vitro BBB modeling or streptozotocin-induced diabetes in rodents, opening questions regarding the translation of the in vitro findings to the in vivo situation, and possible direct effects of streptozotocin on the brain vasculature. Here we used a genetic mouse model of hyperglycemia (Ins2AKITA) to address whether prolonged systemic hyperglycemia induces BBB dysfunction and leakage. We applied a variety of methodologies to carefully evaluate BBB function and cellular integrity in vivo, including the quantification and visualization of specific tracers and evaluation of transcriptional and morphological changes in the BBB and its supporting cellular components. These experiments did neither reveal altered BBB permeability nor morphological changes of the brain vasculature in hyperglycemic mice. We conclude that prolonged hyperglycemia does not lead to BBB dysfunction, and thus the cognitive impairment observed in diabetes may have other causes.
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Affiliation(s)
- Maarja Andaloussi Mäe
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
| | - Tian Li
- Integrated Cardio-Metabolic Centre, Department of Medicine, Karolinska Institute, Huddinge, Sweden
| | - Giacomo Bertuzzi
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,University of Oxford; Physiology, Anatomy & Genetics, The Sherrington Building, Parks Road, Oxford, United Kingdom
| | - Elisabeth Raschperger
- Integrated Cardio-Metabolic Centre, Department of Medicine, Karolinska Institute, Huddinge, Sweden
| | - Michael Vanlandewijck
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,Integrated Cardio-Metabolic Centre, Department of Medicine, Karolinska Institute, Huddinge, Sweden
| | - Liqun He
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury, Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, China
| | - Khayrun Nahar
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Annika Dalheim
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,Department of Surgery, Cardinal Bernardin Cancer Center, Loyola University Chicago, Illinois, United States
| | - Jennifer J Hofmann
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,Concordia University, Austin, Texas, United States
| | - Bàrbara Laviña
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Annika Keller
- Department of Neurosurgery, Clinical Neurocenter, Zürich University Hospital, Zürich University, Zürich, Switzerland
| | - Christer Betsholtz
- Department of Immunology, Genetics, and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.,Integrated Cardio-Metabolic Centre, Department of Medicine, Karolinska Institute, Huddinge, Sweden
| | - Guillem Genové
- Integrated Cardio-Metabolic Centre, Department of Medicine, Karolinska Institute, Huddinge, Sweden.
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Elshaer SL, Evans W, Pentecost M, Lenin R, Periasamy R, Jha KA, Alli S, Gentry J, Thomas SM, Sohl N, Gangaraju R. Adipose stem cells and their paracrine factors are therapeutic for early retinal complications of diabetes in the Ins2 Akita mouse. Stem Cell Res Ther 2018; 9:322. [PMID: 30463601 PMCID: PMC6249931 DOI: 10.1186/s13287-018-1059-y] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/05/2018] [Accepted: 10/23/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Early-stage diabetic retinopathy (DR) is characterized by neurovascular defects. In this study, we hypothesized that human adipose-derived stem cells (ASCs) positive for the pericyte marker CD140b, or their secreted paracrine factors, therapeutically rescue early-stage DR features in an Ins2Akita mouse model. METHODS Ins2Akita mice at 24 weeks of age received intravitreal injections of CD140b-positive ASCs (1000 cells/1 μL) or 20× conditioned media from cytokine-primed ASCs (ASC-CM, 1 μL). Age-matched wildtype mice that received saline served as controls. Visual function experiments and histological analyses were performed 3 weeks post intravitreal injection. Biochemical and molecular analyses assessed the ASC-CM composition and its biological effects. RESULTS Three weeks post-injection, Ins2Akita mice that received ASCs had ameliorated decreased b-wave amplitudes and vascular leakage but failed to improve visual acuity, whereas Ins2Akita mice that received ASC-CM demonstrated amelioration of all aforementioned visual deficits. The ASC-CM group demonstrated partial amelioration of retinal GFAP immunoreactivity and DR-related gene expression but the ASC group did not. While Ins2Akita mice that received ASCs exhibited occasional (1 in 8) hemorrhagic retinas, mice that received ASC-CM had no adverse complications. In vitro, ASC-CM protected against TNFα-induced retinal endothelial permeability as measured by transendothelial electrical resistance. Biochemical and molecular analyses demonstrated several anti-inflammatory proteins including TSG-6 being highly expressed in cytokine-primed ASC-CM. CONCLUSIONS ASCs or their secreted factors mitigate retinal complications of diabetes in the Ins2Akita model. Further investigation is warranted to determine whether ASCs or their secreted factors are safe and effective therapeutic modalities long-term as current locally delivered therapies fail to effectively mitigate the progression of early-stage DR. Nonetheless, our study sheds new light on the therapeutic mechanisms of adult stem cells, with implications for assessing relative risks/benefits of experimental regenerative therapies for vision loss.
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Affiliation(s)
- Sally L. Elshaer
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
- Pharmacology & Toxicology Department, College of Pharmacy, Mansoura University, Mansoura, Egypt
| | - William Evans
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | | | - Raji Lenin
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Ramesh Periasamy
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Kumar Abhiram Jha
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Shanta Alli
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Jordy Gentry
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Samuel M. Thomas
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
| | - Nicolas Sohl
- Cell Care Therapeutics, Inc., Monrovia, CA 91016 USA
| | - Rajashekhar Gangaraju
- Ophthalmology, University of Tennessee Health Science Center, 930 Madison Ave, Suite#768, Memphis, TN 38163 USA
- Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163 USA
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Uehara H, Lesuma T, Stocking P, Jensen N, Kumar SR, Zhang MA, Choi S, Zhang X, Archer B, Carroll L, Ambati BK. Detection of microvascular retinal changes in type I diabetic mice with optical coherence tomography angiography. Exp Eye Res 2018; 178:91-98. [PMID: 30268699 DOI: 10.1016/j.exer.2018.09.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/12/2018] [Accepted: 09/26/2018] [Indexed: 01/01/2023]
Abstract
Optical coherence tomography (OCT) angiography is a dye-free and non-invasive angiography which allows visualization of retinal and choroid vascular flow, enabling observation of highly permeable and three dimensional vasculature. Although OCT angiography is providing new insights in human retinal and choroidal diseases, a few studies have been reported in experimental mice. In this study, to determine the potential of OCT angiography in experimental mice, we sought to examine whether OCT angiography can detect vascular change in type I diabetic mice. To conduct age dependent analysis, 2 and 6 month old male type 1 diabetic Ins2Akita/+ and age matched C57BL/6J mice were used. OCT angiography was performed by Heidelberg Spectralis OCT Angiography Module with 30° lens + mouse adapter lens. We acquired the OCT angiography image from the peripheral nasal position. For analysis of OCT angiography images, OCT angiography positive area were used for vascular density. We analyzed vascular density from the retinal surface (inner limiting membrane) to 120 μm depth with 4 μm steps in order to correlate vascular density vs depth (N = 4 per group). Vascular density of both mouse strains demonstrated three different peaks. By comparing with the OCT image, the first peak (superficial), second peak (intermediate) and third peak (deep) were located in nerve fiber layer/ganglion cell layer, inner plexiform layer/inner nuclear layer and outer plexiform layer/outer nuclear layer, respectively. We calculated vascular density of these peaks separately. In C57BL/6J mice, the vascular density in all three layers do not show significant difference between 2- and 6-month-old. On the other hand, 6-month-old Ins2Akita/+ mice showed a significant decrease of the vascular density in all three layers compared to 2-month-old Ins2Akita/+ mice. Also, the vascular density of 6-month-old Ins2Akita/+ mice in the deep layer showed a significant decrease compared to 2- and 6-month-old C57BL/6J mice. Thus, OCT angiography successfully detects retinal vascular difference between type I diabetic mice and control mice, and age-dependent vasculature change in type I diabetic mice. The diabetic mice demonstrated reduced vascular density due to reduced density of flowing deep vessels. Importantly, we observed this difference without retinal blood leakage, hemorrhage or neovascularization. Our analysis (vascular density vs retinal depth) suggests that OCT angiography is useful for in vivo detection of retinal vasculature alteration in experimental mice.
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Affiliation(s)
- Hironori Uehara
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Timilai Lesuma
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Parker Stocking
- Rocky Vista University College of Osteopathic Medicine, 255 E. Center St. Ivins, UT, 84738, United States
| | - Nathan Jensen
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Sangeetha Ravi Kumar
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Mingyang Aaron Zhang
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Susie Choi
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Xiaohui Zhang
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Bonnie Archer
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Lara Carroll
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States
| | - Balamurali K Ambati
- Dept. of Ophthalmology, Moran Eye Center, University of Utah, 65 Mario Capecchi Dr., Salt Lake City, UT, 84132, United States.
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11
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Hammoum I, Benlarbi M, Dellaa A, Kahloun R, Messaoud R, Amara S, Azaiz R, Charfeddine R, Dogui M, Khairallah M, Lukáts Á, Ben Chaouacha-Chekir R. Retinal dysfunction parallels morphologic alterations and precede clinically detectable vascular alterations in Meriones shawi, a model of type 2 diabetes. Exp Eye Res 2018; 176:174-187. [PMID: 30009825 DOI: 10.1016/j.exer.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/19/2018] [Accepted: 07/05/2018] [Indexed: 12/22/2022]
Abstract
Diabetic retinopathy is a major cause of reduced visual acuity and acquired blindness. The aim of this work was to analyze functional and vascular changes in diabetic Meriones shawi (M.sh) an animal model of metabolic syndrome and type 2 diabetes. The animals were divided into four groups. Two groups were fed a high fat diet (HFD) for 3 and 7 months, two other groups served as age-matched controls. Retinal function was assessed using full field electroretinogram (Ff-ERG). Retinal thickness and vasculature were examined by optical coherence tomography, eye fundus and fluorescein angiography. Immunohistochemistry was used to examine key proteins of glutamate metabolism and synaptic transmission. Diabetic animals exhibited significantly delayed scotopic and photopic ERG responses and decreases in scotopic and photopic a- and b-wave amplitudes at both time points. Furthermore, a decrease of the amplitude of the flicker response and variable changes in the scotopic and photopic oscillatory potentials was reported. A significant decrease in retinal thickness was observed. No evident change in the visual streak area and no sign of vascular abnormality was present; however, some exudates in the periphery were visible in 7 months diabetic animals. Imunohistochemistry detected a decrease in the expression of glutamate synthetase, vesicular glutamate transporter 1 and synaptophysin proteins. Results indicate that a significant retinal dysfunction was present in the HFD induced diabetes involving both rod and cone pathways and this dysfunction correlate well with the morphological abnormalities reported previously. Furthermore, neurodegeneration and abnormalities in retinal function occur before vascular alterations would be detectable in diabetic M.sh.
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Affiliation(s)
- Imane Hammoum
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia; Faculty of Sciences of Tunis, El Manar University (UTM), Tunis, Tunisia
| | - Maha Benlarbi
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Ahmed Dellaa
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Rim Kahloun
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Riadh Messaoud
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Soumaya Amara
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Rached Azaiz
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Ridha Charfeddine
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Mohamed Dogui
- Service of Functional Explorations of the Nervous System, Sahloul University Hospital, Sousse, Tunisia
| | - Moncef Khairallah
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Rafika Ben Chaouacha-Chekir
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia.
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12
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Francis AW, Wanek J, Shahidi M. Assessment of Global and Local Alterations in Retinal Layer Thickness in Ins2 (Akita) Diabetic Mice by Spectral Domain Optical Coherence Tomography. J Ophthalmol 2018; 2018:7253498. [PMID: 29675273 PMCID: PMC5838457 DOI: 10.1155/2018/7253498] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/24/2017] [Indexed: 12/27/2022] Open
Abstract
PURPOSE/AIM The Ins2 (Akita) mouse is a spontaneous diabetic mouse model with a heterozygous mutation in the insulin 2 gene that results in sustained hyperglycemia. The purpose of the study was to assess global and local retinal layer thickness alterations in Akita mice by analysis of spectral domain optical coherence tomography (SD-OCT) images. MATERIALS AND METHODS SD-OCT imaging was performed in Akita and wild-type mice at 12 and 24 weeks of age. Inner retinal thickness (IRT), outer retinal thickness (ORT), total retinal thickness (TRT), and photoreceptor outer segment length (OSL) were measured. Mean global thickness values were compared between Akita and wild-type mice. Local thickness variations in Akita mice were assessed based on normative values in wild-type mice. RESULTS Akita mice had higher blood glucose levels and lower body weights (p < 0.001). On average, IRT, ORT, and TRT were approximately 2% lower in Akita mice than in wild-type mice (p ≤ 0.02). In Akita mice, the percent difference between retinal areas with thickness below and above normative values for IRT, ORT, and TRT was 22%, 32%, and 38%, respectively. CONCLUSIONS These findings support the use of the Akita mouse model to study the retinal neurodegenerative effects of hyperglycemia.
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Affiliation(s)
- Andrew W. Francis
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
| | - Justin Wanek
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, Los Angeles, CA, USA
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13
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Mugisho OO, Green CR, Zhang J, Binz N, Acosta ML, Rakoczy E, Rupenthal ID. Immunohistochemical Characterization of Connexin43 Expression in a Mouse Model of Diabetic Retinopathy and in Human Donor Retinas. Int J Mol Sci 2017; 18:ijms18122567. [PMID: 29186067 PMCID: PMC5751170 DOI: 10.3390/ijms18122567] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 12/25/2022] Open
Abstract
Diabetic retinopathy (DR) develops due to hyperglycemia and inflammation-induced vascular disruptions in the retina with connexin43 expression patterns in the disease still debated. Here, the effects of hyperglycemia and inflammation on connexin43 expression in vitro in a mouse model of DR and in human donor tissues were evaluated. Primary human retinal microvascular endothelial cells (hRMECs) were exposed to high glucose (HG; 25 mM) or pro-inflammatory cytokines IL-1β and TNF-α (10 ng/mL each) or both before assessing connexin43 expression. Additionally, connexin43, glial fibrillary acidic protein (GFAP), and plasmalemma vesicular associated protein (PLVAP) were labeled in wild-type (C57BL/6), Akita (diabetic), and Akimba (DR) mouse retinas. Finally, connexin43 and GFAP expression in donor retinas with confirmed DR was compared to age-matched controls. Co-application of HG and cytokines increased connexin43 expression in hRMECs in line with results seen in mice, with no significant difference in connexin43 or GFAP expression in Akita but higher expression in Akimba compared to wild-type mice. On PLVAP-positive vessels, connexin43 was higher in Akimba but unchanged in Akita compared to wild-type mice. Connexin43 expression appeared higher in donor retinas with confirmed DR compared to age-matched controls, similar to the distribution seen in Akimba mice and correlating with the in vitro results. Although connexin43 expression seems reduced in diabetes, hyperglycemia and inflammation present in the pathology of DR seem to increase connexin43 expression, suggesting a causal role of connexin43 channels in the disease progression.
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Affiliation(s)
- Odunayo O Mugisho
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
- School of Optometry and Vision Science, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
| | - Colin R Green
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
| | - Jie Zhang
- Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
| | - Nicolette Binz
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth 6009, Western Australia, Australia.
| | - Monica L Acosta
- School of Optometry and Vision Science, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
| | - Elizabeth Rakoczy
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth 6009, Western Australia, Australia.
| | - Ilva D Rupenthal
- Buchanan Ocular Therapeutics Unit, Department of Ophthalmology, New Zealand National Eye Centre, University of Auckland, Auckland 1142, New Zealand.
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14
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Neurodegeneration in diabetic retinopathy: Potential for novel therapies. Vision Res 2017; 139:82-92. [PMID: 28988945 DOI: 10.1016/j.visres.2017.06.014] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 06/12/2017] [Accepted: 06/14/2017] [Indexed: 11/20/2022]
Abstract
The complex pathology of diabetic retinopathy (DR) affects both vascular and neural tissue. The characteristics of neurodegeneration are well-described in animal models but have more recently been confirmed in the clinical setting, mostly by using non-invasive imaging approaches such as spectral domain optical coherence tomography (SD-OCT). The most frequent observations report loss of tissue in the nerve fiber layer and inner plexiform layer, confirming earlier findings from animal models. In several cases the reduction in inner retinal layers is reported in patients with little evidence of vascular lesions or macular edema, suggesting that degenerative loss of neural tissue in the inner retina can occur after relatively short durations of diabetes. Animal studies also suggest that neurodegeneration leading to retinal thinning is not limited to cell death and tissue loss but also includes changes in neuronal morphology, reduced synaptic protein expression and alterations in neurotransmission, including changes in expression of neurotransmitter receptors as well as neurotransmitter release, reuptake and metabolism. The concept of neurodegeneration as an early component of DR introduces the possibility to explore alternative therapies to prevent the onset of vision loss, including neuroprotective therapies and drugs targeting individual neurotransmitter systems, as well as more general neuroprotective approaches to preserve the integrity of the neural retina. In this review we consider some of the evidence for progressive retinal neurodegeneration in diabetes, and explore potential neuroprotective therapies.
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15
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Liu W, Wang S, Soetikno B, Yi J, Zhang K, Chen S, Linsenmeier RA, Sorenson CM, Sheibani N, Zhang HF. Increased Retinal Oxygen Metabolism Precedes Microvascular Alterations in Type 1 Diabetic Mice. Invest Ophthalmol Vis Sci 2017; 58:981-989. [PMID: 28535269 PMCID: PMC5308771 DOI: 10.1167/iovs.16-20600] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose To investigate inner retinal oxygen metabolic rate (IRMRO2) during early stages of type 1 diabetes in a transgenic mouse model. Methods In current study, we involved seven diabetic mice (Akita/+, TSP1−/−) and seven control mice (TSP1−/−), and applied visible-light optical coherence tomography (vis-OCT) to image functional parameters including retinal blood flow rate, oxygen saturation (sO2) and the IRMRO2 value longitudinally from 5 weeks of age to 13 weeks of age. After imaging at 13 weeks of age, we analyzed the imaging results, and examined histology of mouse retina. Results Between diabetic mice and the control group, we observed significant differences in venous sO2 from 9 weeks of age (P = 0.006), and significant increment in IRMRO2 from 11 weeks of age (P = 0.001) in diabetic mice compared with control group. We did not find significant differences in retinal blood flow rate as well as arterial sO2 during imaging between diabetic and control mice. Histologic examination of diabetic and control mice at 13 weeks of age also revealed no anatomical retinal alternations. Conclusions In diabetic retinopathy, complications in retinal oxygen metabolism may occur before changes of retinal anatomical structure.
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Affiliation(s)
- Wenzhong Liu
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Shoujian Wang
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Brian Soetikno
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Ji Yi
- Department of Medicine, Boston University, Boston, Massachusetts, United States
| | - Kevin Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Siyu Chen
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States
| | - Robert A Linsenmeier
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States 5Department of Neurobiology, Northwestern University, Evanston, Illinois, United States
| | - Christine M Sorenson
- Department of Pediatrics, University Wisconsin, Madison, Wisconsin, United States
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Science, University of Wisconsin, Madison, Wisconsin, United States
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States 4Department of Ophthalmology, Northwestern University, Chicago, Illinois, United States
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16
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Blair NP, Wanek J, Felder AE, Brewer KC, Joslin CE, Shahidi M. Inner Retinal Oxygen Delivery, Metabolism, and Extraction Fraction in Ins2Akita Diabetic Mice. Invest Ophthalmol Vis Sci 2017; 57:5903-5909. [PMID: 27802520 PMCID: PMC5096417 DOI: 10.1167/iovs.16-20082] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Purpose Retinal nonperfusion and hypoxia are important factors in human diabetic retinopathy, and these presumably inhibit energy production and lead to cell death. The purpose of this study was to elucidate the effect of diabetes on inner retinal oxygen delivery and metabolism in a mouse model of diabetes. Methods Phosphorescence lifetime and blood flow imaging were performed in spontaneously diabetic Ins2Akita (n = 22) and nondiabetic (n = 22) mice at 12 and 24 weeks of age to measure retinal arterial (O2A) and venous (O2V) oxygen contents and total retinal blood flow (F). Inner retinal oxygen delivery (DO2) and metabolism (MO2) were calculated as F ∗ O2A and F ∗ (O2A − O2V), respectively. Oxygen extraction fraction (OEF), which equals MO2/DO2, was calculated. Results DO2 at 12 weeks were 112 ± 40 and 97 ± 29 nL O2/min in nondiabetic and diabetic mice, respectively (NS), and 148 ± 31 and 85 ± 37 nL O2/min at 24 weeks, respectively (P < 0.001). MO2 were 65 ± 31 and 66 ± 27 nL O2/min in nondiabetic and diabetic mice at 12 weeks, respectively, and 79 ± 14 and 54 ± 28 nL O2/min at 24 weeks, respectively (main effects = NS). At 12 weeks OEF were 0.57 ± 0.17 and 0.67 ± 0.09 in nondiabetic and diabetic mice, respectively, and 0.54 ± 0.07 and 0.63 ± 0.08 at 24 weeks, respectively (main effect of diabetes: P < 0.01). Conclusions Inner retinal MO2 was maintained in diabetic Akita mice indicating that elevation of the OEF adequately compensated for reduced DO2 and prevented oxidative metabolism from being limited by hypoxia.
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Affiliation(s)
- Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Justin Wanek
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Anthony E Felder
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Katherine C Brewer
- Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Charlotte E Joslin
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States 2Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States 3University of Illinois Cancer Center, Population Health, Behavior, and Outcomes Program, Chicago, Illinois, United States
| | - Mahnaz Shahidi
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, United States
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17
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Binz N, Rakoczy EP, Ali Rahman IS, Vagaja NN, Lai CM. Biomarkers for Diabetic Retinopathy - Could Endothelin 2 Be Part of the Answer? PLoS One 2016; 11:e0160442. [PMID: 27482904 PMCID: PMC4970817 DOI: 10.1371/journal.pone.0160442] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 07/19/2016] [Indexed: 12/17/2022] Open
Abstract
Purpose The endothelins are a family of three highly conserved and homologous vasoactive peptides that are expressed across all organ systems. Endothelin (Edn) dysregulation has been implicated in a number of pathophysiologies, including diabetes and diabetes-related complications. Here we examined Edn2 and endothelin receptor B (Endrb) expression in retinae of diabetic mouse models and measured serum Edn2 to assess its biomarker potential. Materials and Methods Edn2 and Ednrb mRNA and Edn2 protein expression were assessed in young (8wk) and mature (24wk) C57Bl/6 (wild type; wt), Kimba (model of retinal neovascularisation, RNV), Akita (Type 1 diabetes; T1D) and Akimba mice (T1D plus RNV) by qRT-PCR and immunohistochemistry. Edn2 protein concentration in serum was measured using ELISA. Results Fold-changes in Edn2 and Ednrb mRNA were seen only in young Kimba (Edn2: 5.3; Ednrb: 6.0) and young Akimba (Edn2: 7.9, Ednrb: 8.8) and in mature Kimba (Edn2:9.2, Ednrb:11.2) and mature Akimba (Edn2:14.0, Ednrb:17.5) mice. Co-localisation of Edn2 with Müller-cell-specific glutamine synthetase demonstrated Müller cells and photoreceptors as the major cell types for Edn2 expression in all animal models. Edn2 serum concentrations in young Kimba, Akita and Akimba mice were not elevated compared to wt. However, in mature mice, Edn2 serum concentration was increased in Akimba (6.9pg/mg total serum protein) compared to wt, Kimba and Akita mice (3.9, 4.6, and 3.8pg/mg total serum protein, respectively; p<0.05). Conclusions These results demonstrated that long-term hyperglycaemia in conjunction with VEGF-driven RNV increased Edn2 serum concentration suggesting Edn2 might be a candidate biomarker for vascular changes in diabetic retinopathy.
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MESH Headings
- Animals
- Biomarkers/blood
- Blood Glucose/metabolism
- Diabetes Mellitus, Type 1/blood
- Diabetes Mellitus, Type 1/diagnosis
- Diabetes Mellitus, Type 1/genetics
- Diabetes Mellitus, Type 1/pathology
- Disease Models, Animal
- Endothelin-2/blood
- Endothelin-2/genetics
- Ependymoglial Cells/metabolism
- Ependymoglial Cells/pathology
- Gene Expression
- Glycated Hemoglobin/metabolism
- Hyperglycemia/blood
- Hyperglycemia/diagnosis
- Hyperglycemia/genetics
- Hyperglycemia/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Inbred Strains
- Photoreceptor Cells, Vertebrate/metabolism
- Photoreceptor Cells, Vertebrate/pathology
- RNA, Messenger/blood
- RNA, Messenger/genetics
- Receptor, Endothelin B/blood
- Receptor, Endothelin B/genetics
- Retinal Neovascularization/blood
- Retinal Neovascularization/diagnosis
- Retinal Neovascularization/genetics
- Retinal Neovascularization/pathology
- Vascular Endothelial Growth Factor A/blood
- Vascular Endothelial Growth Factor A/genetics
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Affiliation(s)
- Nicolette Binz
- Molecular Ophthalmology, Lions Eye Institute, Nedlands, WA, 6009, Australia
| | - Elizabeth P. Rakoczy
- Molecular Ophthalmology, Lions Eye Institute, Nedlands, WA, 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, 6009, Australia
- * E-mail:
| | - Ireni S. Ali Rahman
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Nermina N. Vagaja
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Chooi-May Lai
- Molecular Ophthalmology, Lions Eye Institute, Nedlands, WA, 6009, Australia
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, WA, 6009, Australia
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18
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Wang J, Cui X, Roon P, Smith SB. Role of Sigma 1 Receptor in Retinal Degeneration of the Ins2Akita/+ Murine Model of Diabetic Retinopathy. Invest Ophthalmol Vis Sci 2016; 57:2770-81. [PMID: 27206247 PMCID: PMC4884059 DOI: 10.1167/iovs.15-18995] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/17/2016] [Indexed: 01/31/2023] Open
Abstract
PURPOSE Sigma receptor 1 (Sigma1R), a nonopioid putative molecular chaperone, has neuroprotective properties in retina. This study sought to determine whether delaying administration of (+)-pentazocine, a high-affinity Sigma1R ligand after onset of diabetes in Ins2Akita/+ diabetic mice would afford retinal neuroprotection and to determine consequences on retinal phenotype in Ins2Akita/+ diabetic mice in the absence of Sigma1R. METHODS Ins2Akita/+ diabetic and WT mice received intraperitoneal injections of (+)-pentazocine beginning 4 or 8 weeks after onset of diabetes; eyes were harvested at 25 weeks. Retinal histologic sections were analyzed to determine thicknesses of retinal layers, number of ganglion cells, and evidence of gliosis (increased glial fibrillary acidic protein levels). Ins2Akita/+/Sig1R-/-mice were generated and subjected to in vivo assessment of retinal architecture (optical coherence tomography [OCT]) and retinal vasculature using fluorescein angiography (FA) at 12 and 16 weeks compared with age-matched Ins2Akita/+ mice. Eyes were then harvested for retinal morphometric assessment and gliosis assessment. RESULTS Wild-type mice had 13 ± 0.06 cells/100 μm retinal length; cell bodies in Ins2Akita/+ mice injected 4 and 8 weeks after onset of diabetes with (+)-pentazocine retained significantly more ganglion cells compared with Ins2Akita/+ mice (9 ± 0.04) and demonstrated significant attenuation of gliosis. Ins2Akita/+/Sig1R-/-mouse retinas, analyzed to determine whether the Ins2Akita/+ phenotype was accelerated when lacking Sigma1R, revealed increased nerve fiber layer thickness (OCT), evidence of vitreal opacities, and vessel beading (FA) compared with Ins2Akita/+ mice. Morphometric analysis revealed significantly fewer ganglion cells in Ins2Akita/+/Sig1R-/-mice compared with Ins2Akita/+ mice. CONCLUSIONS Sigma1R may be a novel retinal stress modulator, and targeting it even after disease onset may afford retinal neuroprotection.
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Affiliation(s)
- Jing Wang
- Department of Cellular Biology and Anatomy Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
| | - Penny Roon
- Department of Cellular Biology and Anatomy Medical College of Georgia, Augusta University, Augusta, Georgia, United States
| | - Sylvia B. Smith
- Department of Cellular Biology and Anatomy Medical College of Georgia, Augusta University, Augusta, Georgia, United States
- The James and Jean Culver Vision Discovery Institute, Augusta University, Augusta, Georgia, United States
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, Georgia, United States
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Rajagopal R, Bligard GW, Zhang S, Yin L, Lukasiewicz P, Semenkovich CF. Functional Deficits Precede Structural Lesions in Mice With High-Fat Diet-Induced Diabetic Retinopathy. Diabetes 2016; 65:1072-84. [PMID: 26740595 PMCID: PMC5166563 DOI: 10.2337/db15-1255] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/23/2015] [Indexed: 12/23/2022]
Abstract
Obesity predisposes to human type 2 diabetes, the most common cause of diabetic retinopathy. To determine if high-fat diet-induced diabetes in mice can model retinal disease, we weaned mice to chow or a high-fat diet and tested the hypothesis that diet-induced metabolic disease promotes retinopathy. Compared with controls, mice fed a diet providing 42% of energy as fat developed obesity-related glucose intolerance by 6 months. There was no evidence of microvascular disease until 12 months, when trypsin digests and dye leakage assays showed high fat-fed mice had greater atrophic capillaries, pericyte ghosts, and permeability than controls. However, electroretinographic dysfunction began at 6 months in high fat-fed mice, manifested by increased latencies and reduced amplitudes of oscillatory potentials compared with controls. These electroretinographic abnormalities were correlated with glucose intolerance. Unexpectedly, retinas from high fat-fed mice manifested striking induction of stress kinase and neural inflammasome activation at 3 months, before the development of systemic glucose intolerance, electroretinographic defects, or microvascular disease. These results suggest that retinal disease in the diabetic milieu may progress through inflammatory and neuroretinal stages long before the development of vascular lesions representing the classic hallmark of diabetic retinopathy, establishing a model for assessing novel interventions to treat eye disease.
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Affiliation(s)
- Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, MO
| | - Gregory W Bligard
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, MO
| | - Sheng Zhang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, MO
| | - Li Yin
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine in St. Louis, St. Louis, MO
| | - Peter Lukasiewicz
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, MO
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine in St. Louis, St. Louis, MO
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Veenstra A, Liu H, Lee CA, Du Y, Tang J, Kern TS. Diabetic Retinopathy: Retina-Specific Methods for Maintenance of Diabetic Rodents and Evaluation of Vascular Histopathology and Molecular Abnormalities. ACTA ACUST UNITED AC 2015; 5:247-270. [PMID: 26331759 DOI: 10.1002/9780470942390.mo140190] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diabetic retinopathy is a major cause of visual impairment, which continues to increase in prevalence as more and more people develop diabetes. Despite the importance of vision, the retina is one of the smallest tissues in the body, and specialized techniques have been developed to study retinopathy. This article summarizes several methods used to (i) induce diabetes in mice, (ii) maintain the diabetic animals throughout the months required for development of typical vascular histopathology, (iii) evaluate vascular histopathology of diabetic retinopathy, and (iv) quantitate abnormalities implicated in the development of the retinopathy.
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Affiliation(s)
- Alexander Veenstra
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio.,These authors contributed equally to this work
| | - Haitao Liu
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,These authors contributed equally to this work
| | - Chieh Allen Lee
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Yunpeng Du
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio
| | - Jie Tang
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
| | - Timothy S Kern
- Case Western Reserve University and Case Medical Center, Cleveland, Ohio.,Veterans Administration Medical Center Research Service 151, Cleveland, Ohio
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Angiography reveals novel features of the retinal vasculature in healthy and diabetic mice. Exp Eye Res 2015; 138:6-21. [PMID: 26122048 DOI: 10.1016/j.exer.2015.06.023] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 05/07/2015] [Accepted: 06/22/2015] [Indexed: 01/11/2023]
Abstract
The mouse retina is a commonly used animal model for the study of pathogenesis and treatment of blinding retinal vascular diseases such as diabetic retinopathy. In this study, we aimed to characterize normal and pathological variations in vascular anatomy in the mouse retina using fluorescein angiography visualized with scanning laser ophthalmoscopy and optical coherence tomography (SLO-OCT). We examined eyes from C57BL/6J wild type mice as well as the Ins2(Akita) and Akimba mouse models of diabetic retinopathy using the Heidelberg Retinal Angiography (HRA) and OCT system. Angiography was performed on three focal planes to examine distinct vascular layers. For comparison with angiographic data, ex vivo analyses, including Indian ink angiography, histology and 3D confocal scanning laser microscopy were performed in parallel. All layers of the mouse retinal vasculature could be readily visualized during fluorescein angiography by SLO-OCT. Blood vessel density was increased in the deep vascular plexus (DVP) compared with the superficial vascular plexus (SVP). Arteriolar and venular typologies were established and structural differences were observed between venular types. Unexpectedly, the hyaloid artery was found to persist in 15% of C57BL/6 mice, forming anastomoses with peripheral retinal capillaries. Fluorescein leakage was easily detected in Akimba retinae by angiography, but was not observed in Ins2(Akita) mice. Blood vessel density was increased in the DVP of 6 month old Ins2(Akita) mice, while the SVP displayed reduced branching in precapillary arterioles. In summary, we present the first comprehensive characterization of the mouse retinal vasculature by SLO-OCT fluorescein angiography. Using this clinical imaging technique, we report previously unrecognized variations in C57BL/6J vascular anatomy and novel features of vascular retinopathy in the Ins2(Akita) mouse model of diabetes.
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23
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Diabetic retinopathy: recent advances towards understanding neurodegeneration and vision loss. SCIENCE CHINA-LIFE SCIENCES 2015; 58:541-9. [DOI: 10.1007/s11427-015-4856-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 02/02/2015] [Indexed: 12/22/2022]
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Abstract
Diabetic retinopathy (DR) is one of today's main causes of blindness in numerous developed countries worldwide. The underlying pathogenesis of DR is complex and not well understood, thus impeding development of specific, effective treatment modalities. Consequently, the use of animal models of DR is of critical importance for investigating the pathogenesis of and treatment for DR. While rats and mice are the most commonly used animal models of DR, the zebrafish now appears to be a promising model. Nonhuman primates and humans have similar eye structures, and both can develop spontaneous diabetes mellitus (DM). Although various traditionally used animal models of DR undergo a number of pathological changes similar to those of human DR, several human variations, e.g. retinal neovascularization, cannot yet be fully mimicked in any existing animal model of DM. Since both the animal models and the methods chosen for inducing DR have great influence on experimental results, a clear understanding of available animal models is vital for planning an experimental design. In this review, we summarize the mechanisms, methodologies and pros and cons of the most commonly used animal models of DR.
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Affiliation(s)
- Xiaoyan Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , P.R. China
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25
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Karlstetter M, Scholz R, Rutar M, Wong WT, Provis JM, Langmann T. Retinal microglia: just bystander or target for therapy? Prog Retin Eye Res 2014; 45:30-57. [PMID: 25476242 DOI: 10.1016/j.preteyeres.2014.11.004] [Citation(s) in RCA: 372] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 10/24/2022]
Abstract
Resident microglial cells can be regarded as the immunological watchdogs of the brain and the retina. They are active sensors of their neuronal microenvironment and rapidly respond to various insults with a morphological and functional transformation into reactive phagocytes. There is strong evidence from animal models and in situ analyses of human tissue that microglial reactivity is a common hallmark of various retinal degenerative and inflammatory diseases. These include rare hereditary retinopathies such as retinitis pigmentosa and X-linked juvenile retinoschisis but also comprise more common multifactorial retinal diseases such as age-related macular degeneration, diabetic retinopathy, glaucoma, and uveitis as well as neurological disorders with ocular manifestation. In this review, we describe how microglial function is kept in balance under normal conditions by cross-talk with other retinal cells and summarize how microglia respond to different forms of retinal injury. In addition, we present the concept that microglia play a key role in local regulation of complement in the retina and specify aspects of microglial aging relevant for chronic inflammatory processes in the retina. We conclude that this resident immune cell of the retina cannot be simply regarded as bystander of disease but may instead be a potential therapeutic target to be modulated in the treatment of degenerative and inflammatory diseases of the retina.
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Affiliation(s)
- Marcus Karlstetter
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Rebecca Scholz
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Matt Rutar
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jan M Provis
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.
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Hombrebueno JR, Chen M, Penalva RG, Xu H. Loss of synaptic connectivity, particularly in second order neurons is a key feature of diabetic retinal neuropathy in the Ins2Akita mouse. PLoS One 2014; 9:e97970. [PMID: 24848689 PMCID: PMC4029784 DOI: 10.1371/journal.pone.0097970] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 04/26/2014] [Indexed: 11/19/2022] Open
Abstract
Retinal neurodegeneration is a key component of diabetic retinopathy (DR), although the detailed neuronal damage remains ill-defined. Recent evidence suggests that in addition to amacrine and ganglion cell, diabetes may also impact on other retinal neurons. In this study, we examined retinal degenerative changes in Ins2Akita diabetic mice. In scotopic electroretinograms (ERG), b-wave and oscillatory potentials were severely impaired in 9-month old Ins2Akita mice. Despite no obvious pathology in fundoscopic examination, optical coherence tomography (OCT) revealed a progressive thinning of the retina from 3 months onwards. Cone but not rod photoreceptor loss was observed in 3-month-old diabetic mice. Severe impairment of synaptic connectivity at the outer plexiform layer (OPL) was detected in 9-month old Ins2Akita mice. Specifically, photoreceptor presynaptic ribbons were reduced by 25% and postsynaptic boutons by 70%, although the density of horizontal, rod- and cone-bipolar cells remained similar to non-diabetic controls. Significant reductions in GABAergic and glycinergic amacrine cells and Brn3a+ retinal ganglion cells were also observed in 9-month old Ins2Akita mice. In conclusion, the Ins2Akita mouse develops cone photoreceptor degeneration and the impairment of synaptic connectivity at the OPL, predominately resulting from the loss of postsynaptic terminal boutons. Our findings suggest that the Ins2Akita mouse is a good model to study diabetic retinal neuropathy.
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Affiliation(s)
- Jose R. Hombrebueno
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Rosana G. Penalva
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
| | - Heping Xu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, United Kingdom
- * E-mail:
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Wisniewska-Kruk J, Klaassen I, Vogels IMC, Magno AL, Lai CM, Van Noorden CJF, Schlingemann RO, Rakoczy EP. Molecular analysis of blood-retinal barrier loss in the Akimba mouse, a model of advanced diabetic retinopathy. Exp Eye Res 2014; 122:123-31. [PMID: 24703908 DOI: 10.1016/j.exer.2014.03.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 03/06/2014] [Accepted: 03/17/2014] [Indexed: 12/31/2022]
Abstract
The molecular mechanisms of vascular leakage in diabetic macular edema and proliferative retinopathy are poorly understood, mainly due to the lack of reliable in vivo models. The Akimba (Ins2(Akita)VEGF(+/-)) mouse model combines retinal neovascularization with hyperglycemia, and in contrast to other models, displays the majority of signs of advanced clinical diabetic retinopathy (DR). To study the molecular mechanism that underlies the breakdown of the blood-retinal barrier (BRB) in diabetic macular edema and proliferative diabetic retinopathy, we investigated the retinal vasculature of Akimba and its parental mice Kimba (trVEGF029) and Akita (Ins2(Akita)). Quantitative PCR, immunohistochemistry and fluorescein angiography were used to characterize the retinal vasculature with special reference to the inner BRB. Correlations between the degree of fluorescein leakage and retinal gene expression were tested by calculating the Spearman's correlation coefficient. Fluorescein leakage demonstrating BRB loss was observed in Kimba and Akimba, but not in Akita or wild type mice. In Kimba and Akimba mice fluorescein leakage was associated with focal angiogenesis and correlated significantly with Plvap gene expression. PLVAP is an endothelial cell-specific protein that is absent in intact blood-retinal barrier, but its expression significantly increases in pathological conditions such as DR. Furthermore, in Akimba mice BRB disruption was linked to decreased expression of endothelial junction proteins, pericyte dropout and vessel loss. Despite fluorescein leakage, no alteration in BRB protein levels or pericyte coverage was detected in retinas of Kimba mice. In summary, our data not only demonstrate that hyperglycemia sensitizes retinal vasculature to the effects of VEGF, leading to more severe microvascular changes, but also confirm an important role of PLVAP in the regulation of BRB permeability.
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Affiliation(s)
- Joanna Wisniewska-Kruk
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Ingeborg Klaassen
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Ilse M C Vogels
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Aaron L Magno
- Department of Molecular Ophthalmology, Lions Eye Institute, Nedlands, Western Australia, Australia.
| | - Chooi-May Lai
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia.
| | - Cornelis J F Van Noorden
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Reinier O Schlingemann
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Clinical and Molecular Ophthalmogenetics, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Science (KNAW), Amsterdam, The Netherlands.
| | - Elizabeth P Rakoczy
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia.
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Szabadfi K, Pinter E, Reglodi D, Gabriel R. Neuropeptides, trophic factors, and other substances providing morphofunctional and metabolic protection in experimental models of diabetic retinopathy. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2014; 311:1-121. [PMID: 24952915 DOI: 10.1016/b978-0-12-800179-0.00001-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vision is the most important sensory modality for many species, including humans. Damage to the retina results in vision loss or even blindness. One of the most serious complications of diabetes, a disease that has seen a worldwide increase in prevalence, is diabetic retinopathy. This condition stems from consequences of pathological metabolism and develops in 75% of patients with type 1 and 50% with type 2 diabetes. The development of novel protective drugs is essential. In this review we provide a description of the disease and conclude that type 1 diabetes and type 2 diabetes lead to the same retinopathy. We evaluate existing experimental models and recent developments in finding effective compounds against this disorder. In our opinion, the best models are the long-term streptozotocin-induced diabetes and Otsuka Long-Evans Tokushima Fatty and spontaneously diabetic Torii rats, while the most promising substances are topically administered somatostatin and pigment epithelium-derived factor analogs, antivasculogenic substances, and systemic antioxidants. Future drug development should focus on these.
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Affiliation(s)
- Krisztina Szabadfi
- Department of Experimental Zoology and Neurobiology, University of Pecs, Pecs, Hungary; Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary.
| | - Erika Pinter
- Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary; Department of Pharmacology and Pharmacotherapy, University of Pecs, Pecs, Hungary
| | - Dora Reglodi
- Department of Anatomy, PTE MTA Lendulet-PACAP Research Team, University of Pecs, Pecs, Hungary
| | - Robert Gabriel
- Department of Experimental Zoology and Neurobiology, University of Pecs, Pecs, Hungary; Janos Szentagothai Research Center, University of Pecs, Pecs, Hungary
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Vagaja NN, Binz N, McLenachan S, Rakoczy EP, McMenamin PG. Influence of endotoxin-mediated retinal inflammation on phenotype of diabetic retinopathy in Ins2 Akita mice. Br J Ophthalmol 2013; 97:1343-50. [PMID: 23913246 DOI: 10.1136/bjophthalmol-2013-303201] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To evaluate the impact of systemic exposure to bacterial lipopolysaccharide (LPS) on a rodent model of background diabetic retinopathy. METHODS Toll-like receptor 4 (TLR4)-mediated systemic inflammation was induced in Ins2(Akita) heterozygotes and age-matched C57BL6/J-Ins2(+) littermates by single or repeated intraperitoneal injections of the TLR4 ligand LPS (9 µg/g body weight). 24 hours after a single injection in 7-week-old mice retinal Il1b, Tnfa and Vegf transcripts were measured with real-time PCR. Vascular endothelial growth factor (VEGF) protein levels were evaluated with bead-based immunoassay. Leukostasis and endothelial injury were assessed in retinal wholemounts following perfusion with rhodamine or FITC conjugated concanavalin A to label leukocytes and propidium iodide to label dead or injured cells. In mice which had received three fortnightly injections between 10 and 16 weeks of age, retinal thicknesses and vascular structure were evaluated at 17-18 weeks of age using optical coherence tomography (OCT) and fluorescein angiography. Retinal architecture was assesed using resin-based histology. RESULTS Compared with normoglycaemic controls, systemic LPS exposure in Ins2(Akita) mice was associated with a 3.5-fold increase in endothelial cell injury and attenuated leukostasis in the retinal vasculature. Hyperglycaemia or acute LPS inflammation did not increase retinal VEGF content. Thinning (10-13 µm) of posterior retina was detected with OCT 2 weeks after repeated exposure to LPS in Ins2(Akita) mice but not in normoglycaemic controls. Capillary networks and retinal morphology were unaffected by recurrent LPS inflammation in Ins2(Akita) and control mice. CONCLUSIONS In hyperglycaemic mice, exposure to systemic LPS was associated with two hallmark pathologies of early background diabetic retinopathy, namely, the injury of capillary endothelium and in vivo thinning of the retina.
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Affiliation(s)
- Nermina N Vagaja
- Centre for Ophthalmology and Visual Science, University of Western Australia, , Crawley, Western Australia, Australia
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