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Vasović DD, Ivković S, Živanović A, Major T, Milašin JM, Nikolić NS, Simonović JM, Šutulović N, Hrnčić D, Stanojlović O, Vesković M, Rašić DM, Mladenović D. Reduced light exposure mitigates streptozotocin-induced vascular changes and gliosis in diabetic retina by an anti-inflammatory effect and increased retinal cholesterol turnover. Chem Biol Interact 2024; 394:110996. [PMID: 38593908 DOI: 10.1016/j.cbi.2024.110996] [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: 02/11/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/11/2024]
Abstract
Diabetic retinopathy is not cured efficiently and changes of lifestyle measures may delay early retinal injury in diabetes. The aim of our study was to investigate the effects of reduced daily light exposure on retinal vascular changes in streptozotocin (STZ)-induced model of DM with emphasis on inflammation, Aqp4 expression, visual cycle and cholesterol metabolism-related gene expression in rat retina and RPE. Male Wistar rats were divided into the following groups: 1. control; 2. diabetic group (DM) treated with streptozotocin (100 mg/kg); 3. group exposed to light/dark cycle 6/18 h (6/18); 4. diabetic group exposed to light/dark cycle 6/18 h (DM+6/18). Retinal vascular abnormalities were estimated based on lectin staining, while the expression of genes involved in the visual cycle, cholesterol metabolism, and inflammation was determined by qRT-PCR. Reduced light exposure alleviated vasculopathy, gliosis and the expression of IL-1 and TNF-α in the retina with increased perivascular Aqp4 expression. The expression of genes involved in visual cycle and cholesterol metabolism was significantly up-regulated in RPE in DM+6/18 vs. DM group. In the retina only the expression of APOE was significantly higher in DM+6/18 vs. DM group. Reduced light exposure mitigates vascular changes and gliosis in DM via its anti-inflammatory effect, increased retinal cholesterol turnover and perivascular Aqp4 expression.
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Affiliation(s)
- Dolika D Vasović
- Eye Hospital, University Clinical Centre of Serbia, 11000, Belgrade, Serbia
| | - Sanja Ivković
- Department of Molecular Biology and Endocrinology, Vinca - Institute for Nuclear Sciences, National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Ana Živanović
- Department of Molecular Biology and Endocrinology, Vinca - Institute for Nuclear Sciences, National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Tamara Major
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, 11000, Belgrade, Serbia
| | - Jelena M Milašin
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Nađa S Nikolić
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Jelena M Simonović
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Nikola Šutulović
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dragan Hrnčić
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Olivera Stanojlović
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Milena Vesković
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dejan M Rašić
- Eye Hospital, University Clinical Centre of Serbia, 11000, Belgrade, Serbia; School of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dušan Mladenović
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia.
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Tanaka Y, Takagi R, Mitou S, Shimmura M, Hasegawa T, Amarume J, Shinohara M, Kageyama Y, Sasase T, Ohta T, Muramatsu SI, Kakehashi A, Kaburaki T. Protective Effect of Pemafibrate Treatment against Diabetic Retinopathy in Spontaneously Diabetic Torii Fatty Rats. Biol Pharm Bull 2024:b23-00872. [PMID: 38432946 DOI: 10.1248/bpb.b23-00872] [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: 03/05/2024]
Abstract
Diabetic retinopathy (DR) can cause visual impairment and blindness, and the increasing global prevalence of diabetes underscores the need for effective therapies to prevent and treat DR. Therefore, this study aimed to evaluate the protective effect of pemafibrate treatment against DR, using a Spontaneously Diabetic Torii (SDT) fatty rat model of obese type 2 diabetes. SDT fatty rats were fed either a diet supplemented with pemafibrate (0.3 mg/kg/day) for 16 weeks, starting at 8 weeks of age (Pf SDT fatty: study group), or normal chow (SDT fatty: controls). Normal chow was provided to Sprague-Dawley (SD) rats (SD: normal controls). Electroretinography (ERG) was performed at 8 and 24 weeks of age to evaluate the retinal neural function. After sacrifice, retinal thickness, number of retinal folds, and choroidal thickness were evaluated, and immunostaining was performed for aquaporin-4 (AQP4). No significant differences were noted in food consumption, body weight, or blood glucose level after pemafibrate administration. Triglyceride levels were reduced, and high-density lipoprotein cholesterol levels were increased. Extension of oscillatory potential (OP)1 and OP3 waves on ERG was suppressed in the Pf SDT fatty group. Retinal thickness at 1,500 microns from the optic disc improved in the Pf SDT fatty group. No significant improvements were noted in choroidal thickness or number of retinal folds. Quantitative analyses showed that AQP4-positive regions in the retinas were significantly larger in the Pf SDT fatty group than in the SDT fatty group. The findings suggest that pemafibrate treatment can exert protective effects against DR.
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Affiliation(s)
| | - Rina Takagi
- Department of Ophthalmology, Jichi Medical University
| | - Shingen Mitou
- Department of Ophthalmology, Jichi Medical University
| | | | | | | | | | | | - Tomohiko Sasase
- Biological/Pharmacological Research Laboratories, Central Pharmaceutical Research Institute, Japan Tobacco Inc
| | - Takeshi Ohta
- Laboratory of Animal Physiology and Functional Anatomy, Graduate School of Agriculture, Kyoto University
| | - Shin-Ichi Muramatsu
- Division of Neurological Gene Therapy, Center for Open Innovation, Jichi Medical University
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Llorián-Salvador M, Cabeza-Fernández S, Gomez-Sanchez JA, de la Fuente AG. Glial cell alterations in diabetes-induced neurodegeneration. Cell Mol Life Sci 2024; 81:47. [PMID: 38236305 PMCID: PMC10796438 DOI: 10.1007/s00018-023-05024-y] [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: 08/20/2023] [Revised: 10/09/2023] [Accepted: 10/29/2023] [Indexed: 01/19/2024]
Abstract
Type 2 diabetes mellitus is a global epidemic that due to its increasing prevalence worldwide will likely become the most common debilitating health condition. Even if diabetes is primarily a metabolic disorder, it is now well established that key aspects of the pathogenesis of diabetes are associated with nervous system alterations, including deleterious chronic inflammation of neural tissues, referred here as neuroinflammation, along with different detrimental glial cell responses to stress conditions and neurodegenerative features. Moreover, diabetes resembles accelerated aging, further increasing the risk of developing age-linked neurodegenerative disorders. As such, the most common and disabling diabetic comorbidities, namely diabetic retinopathy, peripheral neuropathy, and cognitive decline, are intimately associated with neurodegeneration. As described in aging and other neurological disorders, glial cell alterations such as microglial, astrocyte, and Müller cell increased reactivity and dysfunctionality, myelin loss and Schwann cell alterations have been broadly described in diabetes in both human and animal models, where they are key contributors to chronic noxious inflammation of neural tissues within the PNS and CNS. In this review, we aim to describe in-depth the common and unique aspects underlying glial cell changes observed across the three main diabetic complications, with the goal of uncovering shared glial cells alterations and common pathological mechanisms that will enable the discovery of potential targets to limit neuroinflammation and prevent neurodegeneration in all three diabetic complications. Diabetes and its complications are already a public health concern due to its rapidly increasing incidence, and thus its health and economic impact. Hence, understanding the key role that glial cells play in the pathogenesis underlying peripheral neuropathy, retinopathy, and cognitive decline in diabetes will provide us with novel therapeutic approaches to tackle diabetic-associated neurodegeneration.
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Affiliation(s)
- María Llorián-Salvador
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University, Belfast, UK.
| | - Sonia Cabeza-Fernández
- Institute for Health and Biomedical Research of Alicante (ISABIAL), Alicante, Spain
- Institute of Neuroscience CSIC-UMH, San Juan de Alicante, Spain
| | - Jose A Gomez-Sanchez
- Institute for Health and Biomedical Research of Alicante (ISABIAL), Alicante, Spain
- Institute of Neuroscience CSIC-UMH, San Juan de Alicante, Spain
| | - Alerie G de la Fuente
- Institute for Health and Biomedical Research of Alicante (ISABIAL), Alicante, Spain.
- Institute of Neuroscience CSIC-UMH, San Juan de Alicante, Spain.
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Chan-Ling T, Hu P, Li Calzi S, Warner J, Uddin N, DuPont M, Neuringer M, Kievit P, Renner L, Stoddard J, Ryals R, Boulton ME, McGill T, Grant MB. Glial, Neuronal, Vascular, Retinal Pigment Epithelium, and Inflammatory Cell Damage in a New Western Diet-Induced Primate Model of Diabetic Retinopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1789-1808. [PMID: 36965774 PMCID: PMC10616715 DOI: 10.1016/j.ajpath.2023.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 01/31/2023] [Accepted: 02/16/2023] [Indexed: 03/27/2023]
Abstract
This study investigated retinal changes in a Western diet (WD)-induced nonhuman primate model of type 2 diabetes. Rhesus nonhuman primates, aged 15 to 17 years, were fed a high-fat diet (n = 7) for >5 years reflective of the traditional WD. Age-matched controls (n = 6) were fed a standard laboratory primate diet. Retinal fundus photography, optical coherence tomography, autofluorescence imaging, and fluorescein angiography were performed before euthanasia. To assess diabetic retinopathy (DR), eyes were examined using trypsin digests, lipofuscin autofluorescence, and multimarker immunofluorescence on cross-sections and whole mounts. Retinal imaging showed venous engorgement and tortuosity, aneurysms, macular exudates, dot and blot hemorrhages, and a marked increase in fundus autofluorescence. Post-mortem changes included the following: decreased CD31 blood vessel density (P < 0.05); increased acellular capillaries (P < 0.05); increased density of ionized calcium-binding adaptor molecule expressing amoeboid microglia/macrophage; loss of regular distribution in stratum and spacing typical of ramified microglia; and increased immunoreactivity of aquaporin 4 and glial fibrillary acidic protein (P < 0.05). However, rhodopsin immunoreactivity (P < 0.05) in rods and neuronal nuclei antibody-positive neuronal density of 50% (P < 0.05) were decreased. This is the first report of a primate model of DR solely induced by a WD that replicates key features of human DR.
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Affiliation(s)
- Tailoi Chan-Ling
- Department of Anatomy, Faculty of Medicine and Health, Bosch Institute, University of Sydney, Camperdown, New South Wales, Australia.
| | - Ping Hu
- Department of Anatomy, Faculty of Medicine and Health, Bosch Institute, University of Sydney, Camperdown, New South Wales, Australia; Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama
| | - Sergio Li Calzi
- Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama
| | - Jeff Warner
- Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama
| | - Nasir Uddin
- Department of Anatomy, Faculty of Medicine and Health, Bosch Institute, University of Sydney, Camperdown, New South Wales, Australia; Faculty of Science and Technology, Centre for Research in Therapeutic Solutions, University of Canberra, Bruce, Australian Capital Territory, Australia
| | - Mariana DuPont
- Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama
| | - Martha Neuringer
- Department of Neuroscience, Oregon Health and Science University, Beaverton, Oregon
| | - Paul Kievit
- Division of Cardiometabolic Health, Oregon Health and Science University, Beaverton, Oregon
| | - Lauren Renner
- Department of Neuroscience, Oregon Health and Science University, Beaverton, Oregon
| | - Jonathan Stoddard
- Integrated Pathology Core, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Renee Ryals
- Department of Ophthalmology, Oregon Health and Science University, Beaverton, Oregon
| | - Michael E Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama
| | - Trevor McGill
- Department of Neuroscience, Oregon Health and Science University, Beaverton, Oregon
| | - Maria B Grant
- Department of Ophthalmology and Visual Sciences, University of Alabama, Birmingham, Alabama.
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Mohammed SR, Elmasry K, El-Gamal R, El-Shahat MA, Sherif RN. Alteration of Aquaporins 1 and 4 immunohistochemical and gene expression in the cerebellum of diabetic albino rat. Tissue Cell 2023; 82:102076. [PMID: 36989704 DOI: 10.1016/j.tice.2023.102076] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 03/29/2023]
Abstract
Aquaporins (AQPs) are a family of transmembrane channel proteins. AQP1 and AQP4 are expressed in cerebellum amongst others. This study was designed to assess the effect of diabetes on AQP1 and AQP4 expression in cerebellum of rats. Diabetes was induced by a single intraperitoneal injection of Streptozotocin 45 mg/kg in 24 adult male Sprague Dawley rats. Six rats from control and diabetic groups were sacrificed at one, four, and eight weeks post diabetic confirmation. After eight weeks, measurement of malondialdehyde (MDA), reduced glutathione (GSH) concentrations, and cerebellar mRNA expression for AQP1 and AQP4 genes were performed. Immunohistochemical evaluation of AQP1, AQP4, and glial fibrillary acidic protein (GFAP) for cerebellar sections was performed for all groups. Diabetes caused degenerative changes in Purkinje cells with a significant increase in the cerebellar level of MDA and AQP1 immunoreactivity and a significant decrease in GSH level and AQP4 expression levels. However, the alteration in the AQP1 mRNA level was not statistically significant. GFAP immunoreactivity was increased in 8 W diabetic rats following its decrease in 1 W diabetic rats. Diabetes caused some alteration in the AQPs 1 and 4 expression in the cerebellum of diabetic rats which may contribute to diabetes-induced cerebellar complications.
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Xie Z, Wu X, Cheng R, Huang J, Wang X, Shi Q, Xu B, Paulus YM, Yuan S, Liu Q. A novel model of subretinal edema induced by DL-alpha aminoadipic acid. Exp Eye Res 2023; 228:109388. [PMID: 36652968 DOI: 10.1016/j.exer.2023.109388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/07/2022] [Accepted: 01/12/2023] [Indexed: 01/16/2023]
Abstract
In this study we described a new model of subretinal edema induced by single intraocular injection of DL-alpha-aminoadipic acid (DLAAA) that can be employed to study the mechanism of retinal edema and test the efficacy or potential toxicity of treatments. The progression of subretinal edema was evaluated by fundus photography, fluorescein angiography and optical coherence tomography for up to 4 weeks following DLAAA injection. The VEGF, IL-6, TNF-α, Occludin, ZO-1, AQP4, Kir4.1, GFAP and GS levels were examined in DLAAA models by immunostaining, immumohistochemical staining and Western blot. Additionally, bulk RNA-seq was used to detect the mechanism involved in DLAAA-induced retinal Müller cellular injuries. In vivo and vitro assays were further conducted to confirm the sequencing results. Subretinal edema was successfully induced by DLAAA in New Zealand White rabbits (1.29 mg/eye) and C57BL/6 mice (50 or 100 μg/eye). Our results demonstrated that the disruption of blood-retinal-barrier, including vascular hyperpermeability, inflammation, and Müller cell dysfunction of fluid clearance, was involved in subretinal edema formation in the model. Bulk RNA-seq and in vitro studies indicated the activation of p38 MAPK signaling pathway in DLAAA models. This DLAAA-induced subretinal edema model can be used for mechanistic studies or drug screening.
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Affiliation(s)
- Zhan Xie
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Xinjing Wu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Ruiwen Cheng
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Junlong Huang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Xiuying Wang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Qile Shi
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Bei Xu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yannis M Paulus
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI, USA.
| | - Songtao Yuan
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China.
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China.
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Jung SS, Son J, Yi SJ, Kim K, Park HS, Kang HW, Kim HK. Development of Müller cell-based 3D biomimetic model using bioprinting technology. Biomed Mater 2022; 18. [PMID: 36343367 DOI: 10.1088/1748-605x/aca0d5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/07/2022] [Indexed: 11/09/2022]
Abstract
Müller cells are the principal glial cells for the maintenance of structural stability and metabolic homeostasis in the human retina. Although variousin vitroexperiments using two-dimensional (2D) monolayer cell cultures have been performed, the results provided only limited results because of the lack of 3D structural environment and different cellular morphology. We studied a Müller cell-based 3D biomimetic model for use in experiments on thein vivo-like functions of Müller cells within the sensory retina. Isolated primary Müller cells were bioprinted and a 3D-aligned architecture was induced, which aligned Müller cell structure in retinal tissue. The stereographic and functional characteristics of the biomimetic model were investigated and compared to those of the conventional 2D cultured group. The results showed the potential to generate Müller cell-based biomimetic models with characteristic morphological features such as endfeet, soma, and microvilli. Especially, the 3D Müller cell model under hyperglycemic conditions showed similar responses as observed in thein vivodiabetic model with retinal changes, whereas the conventional 2D cultured group showed different cytokine and growth factor secretions. These results show that our study is a first step toward providing advanced tools to investigate thein vivofunction of Müller cells and to develop complete 3D models of the vertebrate retina.
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Affiliation(s)
- Sung Suk Jung
- Animal and Plant Quarantine Agency, 177 Hyeoksin 8-ro, Gimcheon City, Gyeongsangbuk-do 39660, Republic of Korea
| | - Jeonghyun Son
- Ulsan National Institute of Science and Technology, 50, UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Soo Jin Yi
- Department of Ophthalmology, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, Republic of Korea.,Bio-Medical Institute, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 41944, Republic of Korea.,Department of Biomedical Science, The Graduate School, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, Republic of Korea
| | - Kyungha Kim
- Ulsan National Institute of Science and Technology, 50, UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Han Sang Park
- Department of Ophthalmology, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, Republic of Korea
| | - Hyun-Wook Kang
- Ulsan National Institute of Science and Technology, 50, UNIST-gil, Ulju-gun, Ulsan 44919, Republic of Korea
| | - Hong Kyun Kim
- Department of Ophthalmology, School of Medicine, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, Republic of Korea.,Bio-Medical Institute, Kyungpook National University Hospital, 130 Dongdeok-ro, Jung-gu, Daegu 41944, Republic of Korea.,Department of Biomedical Science, The Graduate School, Kyungpook National University, 680 Gukchaebosang-ro, Jung-gu, Daegu 41944, Republic of Korea
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Neurovascular injury associated non-apoptotic endothelial caspase-9 and astroglial caspase-9 mediate inflammation and contrast sensitivity decline. Cell Death Dis 2022; 13:937. [PMID: 36347836 PMCID: PMC9643361 DOI: 10.1038/s41419-022-05387-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/25/2022] [Accepted: 10/27/2022] [Indexed: 11/11/2022]
Abstract
Retinal neurovascular injuries are a leading cause of vision loss in young adults presenting unmet therapeutic needs. Neurovascular injuries damage homeostatic communication between endothelial, pericyte, glial, and neuronal cells through signaling pathways that remain to be established. To understand the mechanisms that contribute to neuronal death, we use a mouse model of retinal vein occlusion (RVO). Using this model, we previously discovered that after vascular damage, there was non-apoptotic activation of endothelial caspase-9 (EC Casp9); knock-out of EC Casp9 led to a decrease in retinal edema, capillary ischemia, and neuronal death. In this study, we aimed to explore the role of EC Casp9 in vision loss and inflammation. We found that EC Casp9 is implicated in contrast sensitivity decline, induction of inflammatory cytokines, and glial reactivity. One of the noted glial changes was increased levels of astroglial cl-caspase-6, which we found to be activated cell intrinsically by astroglial caspase-9 (Astro Casp9). Lastly, we discovered that Astro Casp9 contributes to capillary ischemia and contrast sensitivity decline after RVO (P-RVO). These findings reveal specific endothelial and astroglial non-apoptotic caspase-9 roles in inflammation and neurovascular injury respectively; and concomitant relevancy to contrast sensitivity decline.
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Ochoa-de la Paz LD, Gulias-Cañizo R. Glia as a key factor in cell volume regulation processes of the central nervous system. Front Cell Neurosci 2022; 16:967496. [PMID: 36090789 PMCID: PMC9453262 DOI: 10.3389/fncel.2022.967496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/03/2022] [Indexed: 11/23/2022] Open
Abstract
Brain edema is a pathological condition with potentially fatal consequences, related to cerebral injuries such as ischemia, chronic renal failure, uremia, and diabetes, among others. Under these pathological states, the cell volume control processes are fully compromised, because brain cells are unable to regulate the movement of water, mainly regulated by osmotic gradients. The processes involved in cell volume regulation are homeostatic mechanisms that depend on the mobilization of osmolytes (ions, organic molecules, and polyols) in the necessary direction to counteract changes in osmolyte concentration in response to water movement. The expression and coordinated function of proteins related to the cell volume regulation process, such as water channels, ion channels, and other cotransport systems in the glial cells, and considering the glial cell proportion compared to neuronal cells, leads to consider the astroglial network the main regulatory unit for water homeostasis in the central nervous system (CNS). In the last decade, several studies highlighted the pivotal role of glia in the cell volume regulation process and water homeostasis in the brain, including the retina; any malfunction of this astroglial network generates a lack of the ability to regulate the osmotic changes and water movements and consequently exacerbates the pathological condition.
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Affiliation(s)
- Lenin David Ochoa-de la Paz
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico
- Asociación para Evitar la Ceguera en México (APEC), Unidad de Investigación APEC-UNAM, Mexico
- *Correspondence: Lenin David Ochoa-de la Paz
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Chen Y, Chen H, Wang C, Yu J, Tao J, Mao J, Shen L. The Correlation between the Increased Expression of Aquaporins on the Inner Limiting Membrane and the Occurrence of Diabetic Macular Edema. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7412208. [PMID: 35528520 PMCID: PMC9071982 DOI: 10.1155/2022/7412208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/23/2022] [Accepted: 04/01/2022] [Indexed: 11/18/2022]
Abstract
Purpose Diabetic macular edema (DME) is a major cause of vision loss in patients with diabetic retinopathy; this study is aimed at comparing the expression of aquaporins (AQPs) on the inner limiting membranes (ILMs) of various vitreoretinal diseases and investigating the role of aquaporins expressed on the ILMs in mediating the occurrence of DME. Methods The whole-mounted ILM specimens surgically excised from patients with various vitreoretinal diseases (idiopathic macular hole, myopic traction maculopathy, and diabetic retinopathy) were analyzed by immunohistochemistry (IHC). The distribution and morphology of AQP4, AQP7, and AQP11 on the ILMs were correlated with immunohistochemical staining characteristics. Moreover, immunofluorescence of AQP4 was performed on the ILM specimens of the patient in four groups: the control group, negative control group, no DME group, and DME group. The immunofluorescence intensity value of AQP4 was measured using ImageJ. The difference between the four groups and the correction between the immunofluorescence value and central foveal thickness (CFT) were analyzed. Results In IHC sections, the expression of AQP4, AQP7, and AQP11 on ILMs of diabetic retinopathy (DR) with macular edema, respectively, seemed to be more abundant than in the idiopathic macular hole (iMH) and myopic traction maculopathy (MTM). Moreover, markedly higher fluorescence intensity of AQP4 of ILMs was determined in the DME group (51.05 ± 5.67) versus the other three groups (P < 0.001). A marked positive association was identified between the fluorescence intensity of AQP4 and CFT (r = 0.758; P = 0.011). Conclusions AQP4, AQP7, and AQP11 can be expressed on human ILM in vivo. The increased expression of AQPs on the ILMs of DR may be associated with the occurrence of DME. Moreover, the degree of DME may be positively correlated with the expression of AQP4 on the ILMs.
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Affiliation(s)
- Yiqi Chen
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China
| | - Huan Chen
- Department of Retina Center, Affiliated Eye Hospital of Wenzhou Medical University, Hangzhou, 310000 Zhejiang Province, China
| | - Chenxi Wang
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China
| | - Jiafeng Yu
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China
| | - Jiwei Tao
- Department of Retina Center, Affiliated Eye Hospital of Wenzhou Medical University, Hangzhou, 310000 Zhejiang Province, China
| | - Jianbo Mao
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China
| | - Lijun Shen
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, Zhejiang, China
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Carpi-Santos R, de Melo Reis RA, Gomes FCA, Calaza KC. Contribution of Müller Cells in the Diabetic Retinopathy Development: Focus on Oxidative Stress and Inflammation. Antioxidants (Basel) 2022; 11:antiox11040617. [PMID: 35453302 PMCID: PMC9027671 DOI: 10.3390/antiox11040617] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/01/2022] [Accepted: 03/15/2022] [Indexed: 01/27/2023] Open
Abstract
Diabetic retinopathy is a neurovascular complication of diabetes and the main cause of vision loss in adults. Glial cells have a key role in maintenance of central nervous system homeostasis. In the retina, the predominant element is the Müller cell, a specialized cell with radial morphology that spans all retinal layers and influences the function of the entire retinal circuitry. Müller cells provide metabolic support, regulation of extracellular composition, synaptic activity control, structural organization of the blood–retina barrier, antioxidant activity, and trophic support, among other roles. Therefore, impairments of Müller actions lead to retinal malfunctions. Accordingly, increasing evidence indicates that Müller cells are affected in diabetic retinopathy and may contribute to the severity of the disease. Here, we will survey recently described alterations in Müller cell functions and cellular events that contribute to diabetic retinopathy, especially related to oxidative stress and inflammation. This review sheds light on Müller cells as potential therapeutic targets of this disease.
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Affiliation(s)
- Raul Carpi-Santos
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (R.C.-S.); (F.C.A.G.)
| | - Ricardo A. de Melo Reis
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil;
| | - Flávia Carvalho Alcantara Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (R.C.-S.); (F.C.A.G.)
| | - Karin C. Calaza
- Instituto de Biologia, Departamento de Neurobiologia, Universidade Federal Fluminense, Niteroi 24210-201, RJ, Brazil
- Correspondence:
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Li X, Zhu J, Zhong Y, Liu C, Yao M, Sun Y, Yao W, Ni X, Zhou F, Yao J, Jiang Q. Targeting long noncoding RNA-AQP4-AS1 for the treatment of retinal neurovascular dysfunction in diabetes mellitus. EBioMedicine 2022; 77:103857. [PMID: 35172268 PMCID: PMC8850682 DOI: 10.1016/j.ebiom.2022.103857] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 11/23/2022] Open
Abstract
Background Diabetic retinopathy (DR) is a leading cause of blindness in the working-age population, which is characterized by retinal neurodegeneration and vascular dysfunction. Long non-coding RNAs (LncRNAs) have emerged as critical regulators in several biological processes and disease progression. Here we investigated the role of lncRNA AQP4-AS1 in retinal neurovascular dysfunction induced by diabetes. Methods Quantitative RT-PCR was used to detect the AQP4-AS1 expression pattern upon diabetes mellitus-related stresses. Visual electrophysiology examination, TUNEL staining, Evans blue staining, retinal trypsin digestion and immunofluorescent staining were conducted to detect the role of AQP4-AS1 in retinal neurovascular dysfunction in vivo. MTT assays, TUNEL staining, PI/Calcein-AM staining, EdU incorporation assay transwell assay and tube formation were conducted to detect the role of AQP4-AS1 in retinal cells function in vitro. qRT-PCR, western blot and in vivo studies were conducted to reveal the mechanism of AQP4-AS1-mediated retinal neurovascular dysfunction. Findings AQP4-AS1 was significantly increased in the clinical samples of diabetic retinopathy patients, high glucose-treated Müller cells, and diabetic retinas of a murine model. AQP4-AS1 silencing in vivo alleviated retinal neurodegeneration and vascular dysfunction as shown by improved retinal capillary degeneration, decreased reactive gliosis, and reduced RGC loss. AQP4-AS1 directly regulated Müller cell function and indirectly affected endothelial cell and RGC function in vitro. Mechanistically, AQP4-AS1 regulated retinal neurovascular dysfunction through affecting AQP4 levels. Interpretation This study reveals AQP4-AS1 is involved in retinal neurovascular dysfunction and expected to become a promising target for the treatment of neurovascular dysfunction in DR. Funding This work was generously supported by the grants from the National Natural Science Foundation of China (Grant No. 81800858, 82070983, 81870679 and 81970823), grants from the Medical Science and Technology Development Project Fund of Nanjing (Grant No ZKX17053 and YKK19158), grants from Innovation Team Project Fund of Jiangsu Province (No. CXTDB2017010), and the Science and Technology Development Plan Project Fund of Nanjing (Grant No 201716007, 201805007 and 201803058).
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Affiliation(s)
- Xiumiao Li
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China
| | - Junya Zhu
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China
| | - Yuling Zhong
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China
| | - Chang Liu
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Mudi Yao
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Yanan Sun
- Eye Institute and Department of Ophthalmology, Eye and ENT Hospital, Fudan University, Shanghai, China
| | - Wen Yao
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China
| | - Xisen Ni
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China
| | - Fen Zhou
- Eye Hospital and School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, China
| | - Jin Yao
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China.
| | - Qin Jiang
- The Affiliated Eye Hospital, Nanjing Medical University, Nanjing 210029, China; The Fourth School of Clinical Medicine, Nanjing Medical University, Nanjing, China.
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Hanaguri J, Nagai N, Yokota H, Kushiyama A, Watanabe M, Yamagami S, Nagaoka T. Fenofibrate Nano-Eyedrops Ameliorate Retinal Blood Flow Dysregulation and Neurovascular Coupling in Type 2 Diabetic Mice. Pharmaceutics 2022; 14:pharmaceutics14020384. [PMID: 35214116 PMCID: PMC8876509 DOI: 10.3390/pharmaceutics14020384] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/22/2022] [Accepted: 01/26/2022] [Indexed: 02/05/2023] Open
Abstract
We investigated the effect of fenofibrate nano-eyedrops (FenoNano) on impaired retinal blood flow regulation in type 2 diabetic mice. Six-week-old db/db mice were randomly divided into an untreated group (n = 6) and treated group, which received FenoNano (n = 6). The longitudinal changes in retinal neuronal function and blood flow responses to systemic hyperoxia and flicker stimulation were evaluated every 2 weeks in diabetic db/db mice treated with FenoNano (n = 6) or the vehicle (n = 6) from ages 8–14 weeks. The retinal blood flow was assessed using laser speckle flowgraphy. We also evaluated the expressions of vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP), and aquaporin 4 (AQP4) and the phosphorylation of peroxisome proliferator-activated receptor alpha (PPAR-α) by immunofluorescence. In db/db mice treated with FenoNano, both responses were restored from 8 to 14 weeks of age compared with the diabetic mice treated with the vehicle. At 14 weeks of age, the impaired regulation of retinal blood flow during systemic hyperoxia and flicker stimulation improved to about half of that in the db/db mice treated with FenoNano compared with the db/m control group (n = 5). FenoNano prevented the activation of VEGF and GFAP expression and increased the AQP4 expression and the phosphorylation of PPAR-α detected by immunofluorescence compared with the diabetic mice treated with the vehicle eyedrop. Our results suggested that the fenofibrate nano-eyedrops prevent retinal glial dysfunction via the phosphorylation of PPAR-α and improves the retinal blood flow dysregulation in type 2 diabetic mice.
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Affiliation(s)
- Junya Hanaguri
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Noriaki Nagai
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Kindai University, Higashi-Osaka 577-8502, Osaka, Japan;
| | - Harumasa Yokota
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Akifumi Kushiyama
- Department of Pharmacotherapy, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan;
| | - Masahisa Watanabe
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Satoru Yamagami
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
| | - Taiji Nagaoka
- Department of Visual Science, Division of Ophthalmology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan; (J.H.); (H.Y.); (M.W.); (S.Y.)
- Correspondence: or ; Tel.: +81-3-3972-8111
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Little K, Llorián-Salvador M, Scullion S, Hernández C, Simó-Servat O, Del Marco A, Bosma E, Vargas-Soria M, Carranza-Naval MJ, Van Bergen T, Galbiati S, Viganò I, Musi CA, Schlingemann R, Feyen J, Borsello T, Zerbini G, Klaassen I, Garcia-Alloza M, Simó R, Stitt AW. Common pathways in dementia and diabetic retinopathy: understanding the mechanisms of diabetes-related cognitive decline. Trends Endocrinol Metab 2022; 33:50-71. [PMID: 34794851 DOI: 10.1016/j.tem.2021.10.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/06/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022]
Abstract
Type 2 diabetes (T2D) is associated with multiple comorbidities, including diabetic retinopathy (DR) and cognitive decline, and T2D patients have a significantly higher risk of developing Alzheimer's disease (AD). Both DR and AD are characterized by a number of pathological mechanisms that coalesce around the neurovascular unit, including neuroinflammation and degeneration, vascular degeneration, and glial activation. Chronic hyperglycemia and insulin resistance also play a significant role, leading to activation of pathological mechanisms such as increased oxidative stress and the accumulation of advanced glycation end-products (AGEs). Understanding these common pathways and the degree to which they occur simultaneously in the brain and retina during diabetes will provide avenues to identify T2D patients at risk of cognitive decline.
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Affiliation(s)
- Karis Little
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - María Llorián-Salvador
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Sarah Scullion
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Cristina Hernández
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain
| | - Olga Simó-Servat
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain
| | - Angel Del Marco
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Esmeralda Bosma
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands
| | - Maria Vargas-Soria
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Maria Jose Carranza-Naval
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | | | - Silvia Galbiati
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Ilaria Viganò
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Clara Alice Musi
- Università Degli Studi di Milano and Istituto di Ricerche Farmacologiche Mario Negri- IRCCS, Milano, Italy
| | - Reiner Schlingemann
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Lausanne, Switzerland
| | | | - Tiziana Borsello
- Università Degli Studi di Milano and Istituto di Ricerche Farmacologiche Mario Negri- IRCCS, Milano, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milano, Italy
| | - Ingeborg Klaassen
- Ocular Angiogenesis Group, University of Amsterdam, Amsterdam, The Netherlands
| | - Monica Garcia-Alloza
- Division of Physiology, School of Medicine, Instituto de Investigacion Biomedica de Cadiz (INIBICA), Universidad de Cadiz, Cadiz, Spain
| | - Rafael Simó
- Vall d'Hebron Research Institute and CIBERDEM (ISCIII), Barcelona, Spain.
| | - Alan W Stitt
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK.
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Abstract
Optic nerve health is essential for proper function of the visual system. However, the pathophysiology of certain neurodegenerative disease processes affecting the optic nerve, such as glaucoma, is not fully understood. Recently, it was hypothesized that a lack of proper clearance of neurotoxins contributes to neurodegenerative diseases. The ability to clear metabolic waste is essential for tissue homeostasis in mammals, including humans. While the brain lacks the traditional lymphatic drainage system identified in other anatomical regions, there is growing evidence of a glymphatic system in the central nervous system, which structurally includes the optic nerve. Named to acknowledge the supportive role of astroglial cells, this perivascular fluid drainage system is essential to remove toxic metabolites from the central nervous system. Herein, we review existing literature describing the physiology and dysfunction of the glymphatic system specifically as it relates to the optic nerve. We summarize key imaging studies demonstrating the existence of a glymphatic system in the optic nerves of wild-type rodents, aquaporin 4-null rodents, and humans; glymphatic imaging studies in diseases where the optic nerve is impaired; and current evidence regarding pharmacological and lifestyle interventions that may help promote glymphatic function to improve optic nerve health. We conclude by highlighting future research directions that could be applied to improve imaging detection and guide therapeutic interventions for diseases affecting the optic nerve.
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Affiliation(s)
- Anisha Kasi
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Crystal Liu
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Muneeb A Faiq
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Kevin C Chan
- Department of Ophthalmology; Department of Radiology; Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health; Center for Neural Science, College of Arts and Science, New York University, New York, NY, USA
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Effects of an Aquaporin 4 Inhibitor, TGN-020, on Murine Diabetic Retina. Int J Mol Sci 2020; 21:ijms21072324. [PMID: 32230876 DOI: 10.3390/ijms21072324] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/20/2020] [Accepted: 03/26/2020] [Indexed: 12/13/2022] Open
Abstract
PURPOSE To investigate the effect of a selective aquaporin 4 (AQP4) inhibitor, 2-(nicotinamide)-1,3,4-thiadiazole (TGN-020), on the expression of vascular endothelial growth factor (VEGF) and reactive oxygen species (ROS) production, as well as on the retinal edema in diabetic retina. METHODS Intravitreal injections of bevacizumab, TGN-020, or phosphate-buffered saline (PBS) were performed on streptozotocin-induced diabetic rats. Retinal sections were immunostained for anti-glial fibrillary acidic protein (GFAP), anti-AQP4, and anti-VEGF. Protein levels of VEGF from collected retinas were determined by Western blot analysis. In addition, retinal vascular leakage of Evans Blue was observed in the flat-mounted retina from the diabetic rats in the presence or absence of TGN-020. Volumetric changes of rat retinal Müller cells (TR-MUL5; transgenic rat Müller cells) and intracellular levels of ROS were determined using flow cytometry analysis of ethidium fluorescence in the presence or absence of TGN-020 or bevacizumab under physiological and high glucose conditions. RESULTS In the diabetic retina, the immunoreactivity and protein levels of VEGF were suppressed by TGN-020. AQP4 immunoreactivity was higher than in the control retinas and the expressions of AQP4 were co-localized with GFAP. Similarly to VEGF, AQP4 and GFAP were also suppressed by TGN-020. In the Evans Blue assay, TGN-020 decreased leakage in the diabetic retinas. In the cultured Müller cells, the increase in cell volumes and intracellular ROS production under high glucose condition were suppressed by exposure to TGN-020 as much as by exposure to bevacizumab. CONCLUSION TGN-020 may have an inhibitory effect on diabetic retinal edema.
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Liu X, Pan G. Roles of Drug Transporters in Blood-Retinal Barrier. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1141:467-504. [PMID: 31571172 PMCID: PMC7120327 DOI: 10.1007/978-981-13-7647-4_10] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Blood-retinal barrier (BRB) includes inner BRB (iBRB) and outer BRB (oBRB), which are formed by retinal capillary endothelial (RCEC) cells and by retinal pigment epithelial (RPE) cells in collaboration with Bruch's membrane and the choriocapillaris, respectively. Functions of the BRB are to regulate fluids and molecular movement between the ocular vascular beds and retinal tissues and to prevent leakage of macromolecules and other potentially harmful agents into the retina, keeping the microenvironment of the retina and retinal neurons. These functions are mainly attributed to absent fenestrations of RCECs, tight junctions, expression of a great diversity of transporters, and coverage of pericytes and glial cells. BRB existence also becomes a reason that systemic administration for some drugs is not suitable for the treatment of retinal diseases. Some diseases (such as diabetes and ischemia-reperfusion) impair BRB function via altering tight junctions, RCEC death, and transporter expression. This chapter will illustrate function of BRB, expressions and functions of these transporters, and their clinical significances.
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Affiliation(s)
- Xiaodong Liu
- grid.254147.10000 0000 9776 7793School of Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu China
| | - Guoyu Pan
- grid.9227.e0000000119573309Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, Shanghai China
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18
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Picconi F, Parravano M, Sciarretta F, Fulci C, Nali M, Frontoni S, Varano M, Caccuri AM. Activation of retinal Müller cells in response to glucose variability. Endocrine 2019; 65:542-549. [PMID: 31327157 DOI: 10.1007/s12020-019-02017-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/11/2019] [Indexed: 12/11/2022]
Abstract
PURPOSE In the earliest stages of diabetic retinopathy (DR), a dysfunction of Müller cells, characterized by high levels of glial fibrillary acidic protein (GFAP), and aquaporins (AQP), has been observed. Although chronic hyperglycemia causes the activation of Müller cells, the effect of glycemic fluctuations is yet unknown. The aim of the study was to analyze the impact of glucose variability on rat retinal Müller cells (rMC-1) adapted to either normal (5 mM) or high (25 mM) glucose levels. METHODS rMC-1 were cultured in a medium containing either 5 mM (N cells) or 25 mM of glucose (H cells) and then incubated for 96 h in a medium containing (a) low glucose (either 1-3 or 5 mM), (b) basal glucose (either 5 or 25 mM), (c) high glucose (either 25 or 45 mM), (d) basal and high glucose alternated every 24 h; (e) low- and high glucose alternated every 24 h; (f) basal glucose with episodes of low glucose for 30 min twice a day. Müller cells activation was evaluated by measuring the levels of GFAP, AQP4, and phospho-active extracellular signal-regulated kinase (pERK). RESULTS Under both basal and high glucose concentrations rMC-1 were viable, but their response to glucose excursions was different. In N cells kept under normal (5 mM) glucose, a significant glial activation was measured not only in response to constant high glucose but also to alternating low/high glucose. In H cells, adapted to 25 mM glucose, a significant response was observed only after exposition to a lower (5 mM) glucose concentration. CONCLUSION Our results highlight Müller cells activation in response to glucose variability and a different susceptibility depending on the basal glucose conditions.
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Affiliation(s)
- Fabiana Picconi
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita Fatebenefratelli Hospital, Rome, Italy
| | | | - Francesca Sciarretta
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Chiara Fulci
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Michela Nali
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Simona Frontoni
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
- Unit of Endocrinology, Diabetes and Metabolism, S. Giovanni Calibita Fatebenefratelli Hospital, Rome, Italy.
| | | | - Anna Maria Caccuri
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
- Center Nanoscience, Nanotechnology, Innovative Instrumentation (NAST), University of Rome Tor Vergata, Rome, Italy
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Aquaporin 4 Suppresses Neural Hyperactivity and Synaptic Fatigue and Fine-Tunes Neurotransmission to Regulate Visual Function in the Mouse Retina. Mol Neurobiol 2019; 56:8124-8135. [PMID: 31190144 PMCID: PMC6834759 DOI: 10.1007/s12035-019-01661-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/22/2019] [Indexed: 01/04/2023]
Abstract
The bidirectional water channel aquaporin 4 (AQP4) is abundantly expressed in the neural tissue. The advantages and disadvantages of AQP4 neural tissue deficiency under pathological conditions, such as inflammation, and relationship with neural diseases, such as Alzheimer’s disease, have been previously reported. However, the physiological functions of AQP4 are not fully understood. Here, we evaluated the role of AQP4 in the mouse retina using Aqp4 knockout (KO) mice. Aqp4 was expressed in Müller glial cells surrounding the synaptic area between photoreceptors and bipolar cells. Both scotopic and photopic electroretinograms showed hyperactive visual responses in KO mice, gradually progressing with age. Moreover, the amplitude reduction after frequent stimuli and synaptic fatigue was more severe in KO mice. Glutamine synthetase, glutamate aspartate transporter, synaptophysin, and the inward potassium channel Kir2.1, but not Kir4.1, were downregulated in KO retinas. KIR2.1 colocalized with AQP4 in Müller glial cells at the synaptic area, and its expression was affected by Aqp4 levels in primary Müller glial cell cultures. Intraocular injection of potassium in wild-type mice led to visual function hyperactivity, as observed in Aqp4 KO mice. Mitochondria molecules, such as Pgc1α and CoxIV, were downregulated, while apoptotic markers were upregulated in KO retinas. AQP4 may fine-tune synaptic activity, most likely by regulating potassium metabolism, at least in part, via collaborating with KIR2.1, and possibly indirectly regulating glutamate kinetics, to inhibit neural hyperactivity and synaptic fatigue which finally affect mitochondria and cause neurodegeneration.
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Saadane A, Mast N, Trichonas G, Chakraborty D, Hammer S, Busik JV, Grant MB, Pikuleva IA. Retinal Vascular Abnormalities and Microglia Activation in Mice with Deficiency in Cytochrome P450 46A1-Mediated Cholesterol Removal. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 189:405-425. [PMID: 30448403 DOI: 10.1016/j.ajpath.2018.10.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/27/2018] [Accepted: 10/15/2018] [Indexed: 12/11/2022]
Abstract
CYP46A1 is the cytochrome P450 enzyme that converts cholesterol to 24-hydroxycholesterol, a cholesterol elimination product and a potent liver X receptor (LXR) ligand. We conducted retinal characterizations of Cyp46a1-/- mice that had normal fasting blood glucose levels but up to a 1.8-fold increase in retinal cholesterol. The retina of Cyp46a1-/- mice exhibited venous beading and tortuosity, microglia/macrophage activation, and increased vascular permeability, features commonly associated with diabetic retinopathy. The expression of Lxrα and Lxrβ was increased in both the whole Cyp46a1-/- retina and retinal macroglia/macrophages. The LXR-target genes were affected as well, primarily in activated microglial cells and macrophages. In the latter, the LXR-transactivated genes (Abca1, Abcg1, Apod, Apoe, Mylip, and Arg2) were up-regulated; similarly, there was an up-regulation of the LXR-transrepressed genes (Ccl2, Ptgs2, Cxcl1, Il1b, Il6, Nos2, and Tnfa). For comparison, gene expression was investigated in bone marrow-derived macrophages from Cyp46a1-/- mice as well as retinal and bone marrow-derived macrophages from Cyp27a1-/- and Cyp27a1-/-Cyp46a1-/- mice. CYP46A1 expression was detected in retinal endothelial cells, and this expression was increased in the proinflammatory environment. Retinal Cyp46a1-/- phosphoproteome revealed altered phosphorylation of 30 different proteins, including tight junction protein zonula occludens 1 and aquaporin 4. Collectively, the data obtained establish metabolic and regulatory significance of CYP46A1 for the retina and suggest pharmacologic activation of CYP46A1 as a potential therapeutic approach to dyslipidemia-induced retinal damage.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology and Visual Sciences, the University Hospitals, Case Western Reserve University, Cleveland, Ohio
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, the University Hospitals, Case Western Reserve University, Cleveland, Ohio
| | - George Trichonas
- Department of Ophthalmology and Visual Sciences, the University Hospitals, Case Western Reserve University, Cleveland, Ohio
| | | | - Sandra Hammer
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, Michigan
| | - Maria B Grant
- Department of Ophthalmology, University of Alabama, Birmingham, Alabama
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, the University Hospitals, Case Western Reserve University, Cleveland, Ohio.
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Jian WX, Zhang Z, Chu SF, Peng Y, Chen NH. Potential roles of brain barrier dysfunctions in the early stage of Alzheimer’s disease. Brain Res Bull 2018; 142:360-367. [DOI: 10.1016/j.brainresbull.2018.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/03/2018] [Accepted: 08/17/2018] [Indexed: 02/07/2023]
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Aggarwal A, Singh I, Sandhir R. Protective effect of S-nitrosoglutathione administration against hyperglycemia induced disruption of blood brain barrier is mediated by modulation of tight junction proteins and cell adhesion molecules. Neurochem Int 2018; 118:205-216. [PMID: 29792953 DOI: 10.1016/j.neuint.2018.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Revised: 04/26/2018] [Accepted: 05/18/2018] [Indexed: 11/30/2022]
Abstract
Diabetes is associated with increased blood brain barrier (BBB) permeability resulting in neurological deficits. The present study investigated the role of S-nitrosoglutathione (GSNO) on tight junction proteins and cell adhesion molecules in streptozotocin-induced diabetic mice. Diabetes was induced by intraperitoneal injection of streptozotocin (40 mg/kg body weight) for 5 days in mice. GSNO was administered daily (100 μg/kg body weight, orally) for 8 weeks after the induction of diabetes. A significant decline was observed in the cognitive ability of diabetic animals assessed using radial arm maze test. A significant increase was observed in nitrotyrosine levels in cortex and hippocampus of diabetic mice. Relative mRNA and protein expression of tight junction proteins viz; zona occludens-1 (ZO-1) and occludin were significantly lower in the microvessels isolated from cortex and hippocampus of diabetic animals, whereas expression of claudin-5 was unaltered. Immunofluorescence of tight junction proteins confirmed loss of ZO-1 and occludin in the diabetic brain. Furthermore, significant increase in interstitial cell adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 mRNA and protein levels was observed in diabetic animals. Ultrastructure of microvessels from diabetic brain was also altered thereby confirming BBB disruption. GSNO administration to diabetic animals, on the other hand, was able to ameliorate loss of ZO-1 and occludin as well as normalize ICAM-1 and VCAM-1 expression, restore BBB integrity, and improve cognitive deficits. The findings clearly suggest that GSNO is a therapeutic molecule with potential to protect BBB and prevent diabetes induced neurological deficits.
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Affiliation(s)
- Aanchal Aggarwal
- Department of Biochemistry, Basic Medical Science Building, Panjab University, Chandigarh, India
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson Veterans Administration Medical Center, Charleston, SC, USA
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Science Building, Panjab University, Chandigarh, India.
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23
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Pena J, Dulger N, Singh T, Zhou J, Majeska R, Redenti S, Vazquez M. Controlled microenvironments to evaluate chemotactic properties of cultured Müller glia. Exp Eye Res 2018; 173:129-137. [PMID: 29753729 DOI: 10.1016/j.exer.2018.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 12/20/2022]
Abstract
Emerging therapies have begun to evaluate the abilities of Müller glial cells (MGCs) to protect and/or regenerate neurons following retina injury. The migration of donor cells is central to many reparative strategies, where cells must achieve appropriate positioning to facilitate localized repair. Although chemical cues have been implicated in the MGC migratory responses of numerous retinopathies, MGC-based therapies have yet to explore the extent to which external biochemical stimuli can direct MGC behavior. The current study uses a microfluidics-based assay to evaluate the migration of cultured rMC-1 cells (as model MGC) in response to quantitatively-controlled microenvironments of signaling factors implicated in retinal regeneration: basic Fibroblast Growth factor (bFGF or FGF2); Fibroblast Growth factor 8 (FGF8); Vascular Endothelial Growth Factor (VEGF); and Epidermal Growth Factor (EGF). Findings indicate that rMC-1 cells exhibited minimal motility in response to FGF2, FGF8 and VEGF, but highly-directional migration in response to EGF. Further, the responses were blocked by inhibitors of EGF-R and of the MAPK signaling pathway. Significantly, microfluidics data demonstrate that changes in the EGF gradient (i.e. change in EGF concentration over distance) resulted in the directional chemotactic migration of the cells. By contrast, small increases in EGF concentration, alone, resulted in non-directional cell motility, or chemokinesis. This microfluidics-enhanced approach, incorporating the ability both to modulate and asses the responses of motile donor cells to a range of potential chemotactic stimuli, can be applied to potential donor cell populations obtained directly from human specimens, and readily expanded to incorporate drug-eluting biomaterials and combinations of desired ligands.
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Affiliation(s)
- Juan Pena
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Nihan Dulger
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Tanya Singh
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Jing Zhou
- Lehman College, Department of Biology, 250 Bedford Park Blvd, Bronx, NY, 10468, USA
| | - Robert Majeska
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Stephen Redenti
- Lehman College, Department of Biology, 250 Bedford Park Blvd, Bronx, NY, 10468, USA; The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Maribel Vazquez
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA; The Graduate Center of the City University of New York, New York, NY, 10016, USA.
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24
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Rübsam A, Parikh S, Fort PE. Role of Inflammation in Diabetic Retinopathy. Int J Mol Sci 2018; 19:ijms19040942. [PMID: 29565290 PMCID: PMC5979417 DOI: 10.3390/ijms19040942] [Citation(s) in RCA: 438] [Impact Index Per Article: 73.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/09/2018] [Accepted: 03/17/2018] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy is a common complication of diabetes and remains the leading cause of blindness among the working-age population. For decades, diabetic retinopathy was considered only a microvascular complication, but the retinal microvasculature is intimately associated with and governed by neurons and glia, which are affected even prior to clinically detectable vascular lesions. While progress has been made to improve the vascular alterations, there is still no treatment to counteract the early neuro-glial perturbations in diabetic retinopathy. Diabetes is a complex metabolic disorder, characterized by chronic hyperglycemia along with dyslipidemia, hypoinsulinemia and hypertension. Increasing evidence points to inflammation as one key player in diabetes-associated retinal perturbations, however, the exact underlying molecular mechanisms are not yet fully understood. Interlinked molecular pathways, such as oxidative stress, formation of advanced glycation end-products and increased expression of vascular endothelial growth factor have received a lot of attention as they all contribute to the inflammatory response. In the current review, we focus on the involvement of inflammation in the pathophysiology of diabetic retinopathy with special emphasis on the functional relationships between glial cells and neurons. Finally, we summarize recent advances using novel targets to inhibit inflammation in diabetic retinopathy.
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Affiliation(s)
- Anne Rübsam
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Sonia Parikh
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Patrice E Fort
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
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25
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Pisani F, Cammalleri M, Dal Monte M, Locri F, Mola MG, Nicchia GP, Frigeri A, Bagnoli P, Svelto M. Potential role of the methylation of VEGF gene promoter in response to hypoxia in oxygen-induced retinopathy: beneficial effect of the absence of AQP4. J Cell Mol Med 2017; 22:613-627. [PMID: 28940930 PMCID: PMC5742711 DOI: 10.1111/jcmm.13348] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 07/11/2017] [Indexed: 12/16/2022] Open
Abstract
Hypoxia‐dependent accumulation of vascular endothelial growth factor (VEGF) plays a major role in retinal diseases characterized by neovessel formation. In this study, we investigated whether the glial water channel Aquaporin‐4 (AQP4) is involved in the hypoxia‐dependent VEGF upregulation in the retina of a mouse model of oxygen‐induced retinopathy (OIR). The expression levels of VEGF, the hypoxia‐inducible factor‐1α (HIF‐1α) and the inducible form of nitric oxide synthase (iNOS), the production of nitric oxide (NO), the methylation status of the HIF‐1 binding site (HBS) in the VEGF gene promoter, the binding of HIF‐1α to the HBS, the retinal vascularization and function have been determined in the retina of wild‐type (WT) and AQP4 knock out (KO) mice under hypoxic (OIR) or normoxic conditions. In response to 5 days of hypoxia, WT mice were characterized by (i) AQP4 upregulation, (ii) increased levels of VEGF, HIF‐1α, iNOS and NO, (iii) pathological angiogenesis as determined by engorged retinal tufts and (iv) dysfunctional electroretinogram (ERG). AQP4 deletion prevents VEGF, iNOS and NO upregulation in response to hypoxia thus leading to reduced retinal damage although in the presence of high levels of HIF‐1α. In AQP4 KO mice, HBS demethylation in response to the beginning of hypoxia is lower than in WT mice reducing the binding of HIF‐1α to the VEGF gene promoter. We conclude that in the absence of AQP4, an impaired HBS demethylation prevents HIF‐1 binding to the VEGF gene promoter and the relative VEGF transactivation, reducing the VEGF‐induced retinal damage in response to hypoxia.
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Affiliation(s)
- Francesco Pisani
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | | | | | - Filippo Locri
- Department of Biology, University of Pisa, Pisa, Italy
| | - Maria Grazia Mola
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Grazia Paola Nicchia
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Antonio Frigeri
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, Bari, Italy
| | - Paola Bagnoli
- Department of Biology, University of Pisa, Pisa, Italy
| | - Maria Svelto
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.,Institute of Biomembranes and Bioenergetics, National Research Council, Bari, Italy
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26
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Venkat P, Chopp M, Chen J. Blood-Brain Barrier Disruption, Vascular Impairment, and Ischemia/Reperfusion Damage in Diabetic Stroke. J Am Heart Assoc 2017; 6:e005819. [PMID: 28572280 PMCID: PMC5669184 DOI: 10.1161/jaha.117.005819] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Poornima Venkat
- Department of Neurology Research, Henry Ford Hospital, Detroit, MI
| | - Michael Chopp
- Department of Neurology Research, Henry Ford Hospital, Detroit, MI
- Department of Physics, Oakland University, Rochester, MI
| | - Jieli Chen
- Department of Neurology Research, Henry Ford Hospital, Detroit, MI
- Neurological & Gerontology Institute, Neurology, Tianjin Medical University General Hospital, Tianjin, China
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27
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Takahashi T, Fujimura M, Koyama M, Kanazawa M, Usuki F, Nishizawa M, Shimohata T. Methylmercury Causes Blood-Brain Barrier Damage in Rats via Upregulation of Vascular Endothelial Growth Factor Expression. PLoS One 2017; 12:e0170623. [PMID: 28118383 PMCID: PMC5261729 DOI: 10.1371/journal.pone.0170623] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/07/2017] [Indexed: 01/24/2023] Open
Abstract
Clinical manifestations of methylmercury (MeHg) intoxication include cerebellar ataxia, concentric constriction of visual fields, and sensory and auditory disturbances. The symptoms depend on the site of MeHg damage, such as the cerebellum and occipital lobes. However, the underlying mechanism of MeHg-induced tissue vulnerability remains to be elucidated. In the present study, we used a rat model of subacute MeHg intoxication to investigate possible MeHg-induced blood-brain barrier (BBB) damage. The model was established by exposing the rats to 20-ppm MeHg for up to 4 weeks; the rats exhibited severe cerebellar pathological changes, although there were no significant differences in mercury content among the different brain regions. BBB damage in the cerebellum after MeHg exposure was confirmed based on extravasation of endogenous immunoglobulin G (IgG) and decreased expression of rat endothelial cell antigen-1. Furthermore, expression of vascular endothelial growth factor (VEGF), a potent angiogenic growth factor, increased markedly in the cerebellum and mildly in the occipital lobe following MeHg exposure. VEGF expression was detected mainly in astrocytes of the BBB. Intravenous administration of anti-VEGF neutralizing antibody mildly reduced the rate of hind-limb crossing signs observed in MeHg-exposed rats. In conclusion, we demonstrated for the first time that MeHg induces BBB damage via upregulation of VEGF expression at the BBB in vivo. Further studies are required in order to determine whether treatment targeted at VEGF can ameliorate MeHg-induced toxicity.
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Affiliation(s)
- Tetsuya Takahashi
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Masatake Fujimura
- Department of Basic Medical Sciences, National Institute for Minamata Disease, Minamata, Kumamoto, Japan
| | - Misaki Koyama
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Masato Kanazawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Fusako Usuki
- Department of Clinical Medicine, National Institute for Minamata Disease, Minamata, Kumamoto, Japan
| | - Masatoyo Nishizawa
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
| | - Takayoshi Shimohata
- Department of Neurology, Brain Research Institute, Niigata University, Niigata, Niigata, Japan
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28
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Gleiser C, Wagner A, Fallier-Becker P, Wolburg H, Hirt B, Mack AF. Aquaporin-4 in Astroglial Cells in the CNS and Supporting Cells of Sensory Organs-A Comparative Perspective. Int J Mol Sci 2016; 17:E1411. [PMID: 27571065 PMCID: PMC5037691 DOI: 10.3390/ijms17091411] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 08/22/2016] [Accepted: 08/23/2016] [Indexed: 01/28/2023] Open
Abstract
The main water channel of the brain, aquaporin-4 (AQP4), is one of the classical water-specific aquaporins. It is expressed in many epithelial tissues in the basolateral membrane domain. It is present in the membranes of supporting cells in most sensory organs in a specifically adapted pattern: in the supporting cells of the olfactory mucosa, AQP4 occurs along the basolateral aspects, in mammalian retinal Müller cells it is highly polarized. In the cochlear epithelium of the inner ear, it is expressed basolaterally in some cells but strictly basally in others. Within the central nervous system, aquaporin-4 (AQP4) is expressed by cells of the astroglial family, more specifically, by astrocytes and ependymal cells. In the mammalian brain, AQP4 is located in high density in the membranes of astrocytic endfeet facing the pial surface and surrounding blood vessels. At these locations, AQP4 plays a role in the maintenance of ionic homeostasis and volume regulation. This highly polarized expression has not been observed in the brain of fish where astroglial cells have long processes and occur mostly as radial glial cells. In the brain of the zebrafish, AQP4 immunoreactivity is found along the radial extent of astroglial cells. This suggests that the polarized expression of AQP4 was not present at all stages of evolution. Thus, a polarized expression of AQP4 as part of a control mechanism for a stable ionic environment and water balanced occurred at several locations in supporting and glial cells during evolution. This initially basolateral membrane localization of AQP4 is shifted to highly polarized expression in astrocytic endfeet in the mammalian brain and serves as a part of the neurovascular unit to efficiently maintain homeostasis.
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Affiliation(s)
- Corinna Gleiser
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Andreas Wagner
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Petra Fallier-Becker
- Institute of Pathology and Neuropathology, Eberhard Karls Universität Tübingen, 72076 Tubingen, Germany.
| | - Hartwig Wolburg
- Institute of Pathology and Neuropathology, Eberhard Karls Universität Tübingen, 72076 Tubingen, Germany.
| | - Bernhard Hirt
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
| | - Andreas F Mack
- Institute of Clinical Anatomy and Cell Analysis, Eberhard Karls Universität Tübingen, 72074 Tübingen, Germany.
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29
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Amann B, Kleinwort KJH, Hirmer S, Sekundo W, Kremmer E, Hauck SM, Deeg CA. Expression and Distribution Pattern of Aquaporin 4, 5 and 11 in Retinas of 15 Different Species. Int J Mol Sci 2016; 17:ijms17071145. [PMID: 27438827 PMCID: PMC4964518 DOI: 10.3390/ijms17071145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 04/25/2016] [Accepted: 07/12/2016] [Indexed: 12/28/2022] Open
Abstract
Aquaporins (AQPs) are small integral membrane proteins with 13 members in mammals and are essential for water transport across membranes. They are found in many different tissues and cells. Currently, there are conflicting results regarding retinal aquaporin expression and subcellular localization between genome and protein analyses and among various species. AQP4, 7, 9 and 11 were described in the retina of men; whereas AQP6, 8 and 10 were earlier identified in rat retinas and AQP4, 5 and 11 in horses. Since there is a lack of knowledge regarding AQP expression on protein level in retinas of different animal models, we decided to analyze retinal cellular expression of AQP4, 5 and 11 in situ with immunohistochemistry. AQP4 was detected in all 15 explored species, AQP5 and AQP11 in 14 out of 15. Interestingly, AQP4 was unambiguously expressed in Muller glial cells, whereas AQP5 was differentially allocated among the species analyzed. AQP11 expression was Muller glial cell-specific in 50% of the animals, whereas in the others, AQP11 was detected in ganglion cell layer and at photoreceptor outer segments. Our data indicate a disparity in aquaporin distribution in retinas of various animals, especially for AQP5 and 11.
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Affiliation(s)
- Barbara Amann
- Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University, Veterinärstraße 13, D-80539 Munich, Germany.
| | - Kristina J H Kleinwort
- Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University, Veterinärstraße 13, D-80539 Munich, Germany.
| | - Sieglinde Hirmer
- Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University, Veterinärstraße 13, D-80539 Munich, Germany.
| | - Walter Sekundo
- Clinic for Ophthalmology, University Clinic Gießen und Marburg GmbH, Marburg, Baldingerstrasse, D-35033 Marburg, Germany.
| | - Elisabeth Kremmer
- Institute of Molecular Immunology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Marchioninistraße 25, D-81377 München, Germany.
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Heidemannstr. 1, D-80939 München, Germany.
| | - Cornelia A Deeg
- Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University, Veterinärstraße 13, D-80539 Munich, Germany.
- Experimental Ophthalmology, Philipps University of Marburg, Baldingerstrasse, D-35033 Marburg, Germany.
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30
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Negative impact of AQP-4 channel inhibition on survival of retinal ganglion cells and glutamate metabolism after crushing optic nerve. Exp Eye Res 2016; 146:118-127. [DOI: 10.1016/j.exer.2015.12.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/30/2015] [Accepted: 12/30/2015] [Indexed: 01/02/2023]
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31
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Nicchia GP, Pisani F, Simone L, Cibelli A, Mola MG, Dal Monte M, Frigeri A, Bagnoli P, Svelto M. Glio-vascular modifications caused by Aquaporin-4 deletion in the mouse retina. Exp Eye Res 2016; 146:259-268. [DOI: 10.1016/j.exer.2016.03.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/08/2016] [Accepted: 03/22/2016] [Indexed: 10/22/2022]
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32
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Gaddini L, Varano M, Matteucci A, Mallozzi C, Villa M, Pricci F, Malchiodi-Albedi F. Müller glia activation by VEGF-antagonizing drugs: An in vitro study on rat primary retinal cultures. Exp Eye Res 2015; 145:158-163. [PMID: 26607807 DOI: 10.1016/j.exer.2015.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 10/28/2015] [Accepted: 11/10/2015] [Indexed: 11/27/2022]
Abstract
The effects of the anti-Vascular Endothelial Growth Factor (VEGF) drugs ranibizumab and aflibercept were studied in Müller glia in primary mixed cultures from rat neonatal retina. Treatment with both agents induced activation of Müller glia, demonstrated by increased levels of Glial Fibrillary Acidic Protein. In addition, phosphorylated Extracellular-Regulated Kinase 1/2 (ERK 1/2) showed enhanced immunoreactivity in activated Müller glia. Treatment with aflibercept induced an increase in K(+) channel (Kir) 4.1 levels and both drugs upregulated Aquaporin 4 (AQP4) in activated Müller glia. The results show that VEGF-antagonizing drugs influence the homeostasis of Müller cells in primary retinal cultures, inducing an activated phenotype. Upregulation of Kir4.1 and AQP4 suggests that Müller glia activation following anti-VEGF drugs may not depict a detrimental gliotic reaction. Indeed, it could represent one of the mechanisms able to contribute to the therapeutic effects of these drugs, particularly in the presence of macular edema.
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Affiliation(s)
- Lucia Gaddini
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy
| | - Monica Varano
- GB Bietti Eye Foundation IRCCS, Via Livenza, 3, Rome, 00198, Italy
| | - Andrea Matteucci
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy
| | - Cinzia Mallozzi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy
| | - Marika Villa
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy
| | - Flavia Pricci
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy
| | - Fiorella Malchiodi-Albedi
- Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena, 299, Rome, 00161, Italy.
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33
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Oku H, Morishita S, Horie T, Kida T, Mimura M, Fukumoto M, Kojima S, Ikeda T. Nitric Oxide Increases the Expression of Aquaporin-4 Protein in Rat Optic Nerve Astrocytes through the Cyclic Guanosine Monophosphate/Protein Kinase G Pathway. Ophthalmic Res 2015; 54:212-21. [PMID: 26517822 DOI: 10.1159/000440846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/03/2015] [Indexed: 11/19/2022]
Abstract
AIMS Nitric oxide (NO) is associated with neuroinflammation in the central nervous system. We determined whether NO increases the expression of aquaporin-4 (AQP4) in optic nerve astrocytes of rats. METHODS Isolated astrocytes were incubated under normoxic or hypoxic conditions with or without glucose (5.5 mM). The astrocytes were also exposed to different concentrations of S-nitroso-N-acetyl-DL-penicillamine (SNAP, 1.0-100 μM), an NO donor. The expression of AQP4 was determined by Western blot analyses, and NO formation was measured by the Griess reaction. The changes in astrocytic cellular volumes were determined by flow cytometry. RESULTS Hypoxia and glucose deprivation increased AQP4 expression and NO formation. Inhibition of NO synthetase (NOS) significantly suppressed these changes. SNAP caused a significant increase in AQP4 expression, and the increase was significantly suppressed by carboxy-PTIO, a scavenger of NO. Incubation with 8-Br-cyclic guanosine monophosphate (cGMP) mimicked the effects of SNAP, while the addition of either 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ; inhibitor of soluble guanylate cyclase) or KT5823 (protein kinase G inhibitor) suppressed the SNAP-induced increase in AQP4 significantly. SNAP also caused a significant increase in astrocytic cellular volume through the AQP4 channels. CONCLUSIONS NO increased the AQP4 expression of optic nerve astrocytes through the cGMP/protein kinase G pathway and enlarged their volume.
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Affiliation(s)
- Hidehiro Oku
- Department of Ophthalmology, Osaka Medical College, Takatsuki, Japan
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34
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de Senna PN, Xavier LL, Bagatini PB, Saur L, Galland F, Zanotto C, Bernardi C, Nardin P, Gonçalves CA, Achaval M. Physical training improves non-spatial memory, locomotor skills and the blood brain barrier in diabetic rats. Brain Res 2015; 1618:75-82. [PMID: 26032744 DOI: 10.1016/j.brainres.2015.05.026] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 05/19/2015] [Accepted: 05/22/2015] [Indexed: 10/23/2022]
Abstract
Type 1 diabetes mellitus (T1DM) progressively affects cognitive domains, increases blood-brain barrier (BBB) permeability and promotes neurovascular impairment in specific brain areas. Physical exercise, on the other hand, has beneficial effects on brain functions, improving learning and memory. This study investigated the effects of treadmill training on cognitive and motor behavior, and on the expression of proteins related to BBB integrity, such as claudin-5 and aquaporin-4 (AQP4) in the hippocampus and striatum in diabetic rats. For this study, 60 Wistar rats were divided into four groups (n=15 per group): non-trained control (NTC), trained control (TC), non-trained diabetic (NTD), trained diabetic (TD). After diabetic induction of 30 days by streptozotocin injection, the exercise groups were submitted to 5 weeks of running training. After that, all groups were assessed in a novel object-recognition task (NOR) and the rotarod test. Additionally, claudin-5 and AQP4 levels were measured using biochemical assays. The results showed that exercise enhanced NOR task performance and rotarod ability in the TC and TD animals. Diabetes produced a decrease in claudin-5 expression in the hippocampus and striatum and reduced AQP4 in the hippocampus. Exercise preserved the claudin-5 content in the striatum of TD rats, but not in the hippocampus. The reduction of AQP4 levels produced by diabetes was not reversed by exercise. We conclude that exercise improves short-term memory retention, enhances motor performance in diabetic rats and affects important structural components of the striatal BBB. The results obtained could enhance the knowledge regarding the neurochemical benefits of exercise in diabetes.
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Affiliation(s)
- Priscylla Nunes de Senna
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Laboratório de Biologia Celular e Tecidual, Departamento de Ciências Morfofisiológicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Léder Leal Xavier
- Laboratório de Biologia Celular e Tecidual, Departamento de Ciências Morfofisiológicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Pamela Brambilla Bagatini
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Lisiani Saur
- Laboratório de Biologia Celular e Tecidual, Departamento de Ciências Morfofisiológicas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Fabiana Galland
- Departamento de Bioquímica, Instituto de Ciências Básica da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Caroline Zanotto
- Departamento de Bioquímica, Instituto de Ciências Básica da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Caren Bernardi
- Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil
| | - Patrícia Nardin
- Departamento de Bioquímica, Instituto de Ciências Básica da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Carlos Alberto Gonçalves
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Departamento de Bioquímica, Instituto de Ciências Básica da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Matilde Achaval
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Suzuki H, Oku H, Horie T, Morishita S, Tonari M, Oku K, Okubo A, Kida T, Mimura M, Fukumoto M, Kojima S, Takai S, Ikeda T. Changes in expression of aquaporin-4 and aquaporin-9 in optic nerve after crushing in rats. PLoS One 2014; 9:e114694. [PMID: 25479407 PMCID: PMC4257723 DOI: 10.1371/journal.pone.0114694] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/12/2014] [Indexed: 12/23/2022] Open
Abstract
The purpose of this study was to determine the temporal and spatial changes in the expression of AQP4 and AQP9 in the optic nerve after it is crushed. The left optic nerves of rats were either crushed (crushed group) or sham operated (sham group), and they were excised before, and at 1, 2, 4, 7, and 14 days later. Four optic nerves were pooled for each time point in both groups. The expression of AQP4 and AQP9 was determined by western blot analyses. Immunohistochemistry was used to determine the spatial expression of AQP4, AQP9, and GFAP in the optic nerve. Optic nerve edema was determined by measuring the water content in the optic nerve. The barrier function of the optic nerve vessels was determined by the extravasated Evans blue dye on days 7 and 14. The results showed that the expression of AQP4 was increased on day 1 but the level was significantly lower than that in the sham group on days 4 and 7 (P<0.05). In contrast, the expression of AQP9 gradually increased, and the level was significantly higher than that in the sham group on days 7 and 14 (P<0.05, Tukey-Kramer). The down-regulation of AQP4 was associated with crush-induced optic nerve edema, and the water content of the nerve was significantly increased by 4.3% in the crushed optic nerve from that of the untouched fellow nerve on day 7. The expression of AQP4 and GFAP was reduced at the crushed site where AQP4-negative and AQP9-positive astrocytes were present. The barrier function was impaired at the crushed site on days 7 and 14, restrictedly where AQP4-negative and AQP9-positive astrocytes were present. The presence of AQP9-positive astrocytes at the crushed site may counteract the metabolic damage but this change did not fully compensate for the barrier function defect.
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Affiliation(s)
- Hiroyuki Suzuki
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Hidehiro Oku
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
- * E-mail:
| | - Taeko Horie
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Seita Morishita
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Masahiro Tonari
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Kazuma Oku
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Akiko Okubo
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Teruyo Kida
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Masashi Mimura
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | | | - Shota Kojima
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Shinji Takai
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
| | - Tsunehiko Ikeda
- Department of Ophthalmology, Osaka Medical College, Osaka, Japan
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Aggarwal A, Khera A, Singh I, Sandhir R. S-nitrosoglutathione prevents blood-brain barrier disruption associated with increased matrix metalloproteinase-9 activity in experimental diabetes. J Neurochem 2014; 132:595-608. [PMID: 25187090 DOI: 10.1111/jnc.12939] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 08/10/2014] [Accepted: 08/20/2014] [Indexed: 12/14/2022]
Abstract
Hyperglycemia is known to induce microvascular complications, thereby altering blood-brain barrier (BBB) permeability. This study investigated the role of matrix metalloproteinases (MMPs) and their endogenous inhibitors in increased BBB permeability and evaluated the protective effect of S-nitrosoglutathione (GSNO) in diabetes. Diabetes was induced in mice by intraperitoneal injection of streptozotocin (40 mg/kg body weight) for 5 days and GSNO was administered orally (100 μg/kg body weight) daily for 8 weeks after the induction of diabetes. A significant decline in cognitive functions was observed in diabetic mice assessed by Morris water maze test. Increased permeability to different molecular size tracers accompanied by edema and ion imbalance was observed in cortex and hippocampus of diabetic mice. Furthermore, activity of both pro and active MMP-9 was found to be significantly elevated in diabetic animals. Increased in situ gelatinase activity was observed in tissue sections and isolated microvessels from diabetic mice brain. The increase in activity of MMP-9 was attributed to increased mRNA and protein expression in diabetic mice. In addition, a significant decrease in mRNA and protein expression of tissue inhibitor of matrix metalloproteinase-1 was also observed in diabetic animals. However, GSNO supplementation to diabetic animals was able to abridge MMP-9 activation as well as tissue inhibitor of matrix metalloproteinase-1 levels, restoring BBB integrity and also improving learning and memory. Our findings clearly suggest that GSNO could prevent hyperglycemia-induced disruption of BBB by suppressing MMP-9 activity.
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Affiliation(s)
- Aanchal Aggarwal
- Department of Biochemistry, Basic Medical Science Building, Panjab University, Chandigarh, India
| | - Alka Khera
- Department of Biochemistry, Basic Medical Science Building, Panjab University, Chandigarh, India
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Rajat Sandhir
- Department of Biochemistry, Basic Medical Science Building, Panjab University, Chandigarh, India
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Semeraro F, Russo A, Rizzoni D, Danzi P, Morescalchi F, Costagliola C. Diameters and wall-to-lumen ratio of retinal arterioles in patients with retinal vein occlusion before and after treatment with dexamethasone intravitreal implants. J Ocul Pharmacol Ther 2014; 30:573-9. [PMID: 24828375 DOI: 10.1089/jop.2013.0130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND To evaluate the diameters and wall-to-lumen ratio (WLR) of retinal arterioles in patients with retinal vein occlusion (RVO) before and after a 0.7 mg dexamethasone (DEX) intravitreal implant and compare it with a matched control group of normal eyes. METHODS This was a single-site, multi-investigator, prospective, open-label, observational study in 15 patients with vision loss due to branch or central RVO treated with a single injection of DEX implant. An age-matched control group of 16 normal eyes was recruited. External and internal arteriolar diameters, WLR, and wall thickness were assessed in vivo using scanning-laser Doppler flowmetry. Visual acuity (VA) and central macular thickness (CMT) were evaluated. RESULTS Mean internal diameter showed a significant reduction in post-treatment RVO patients compared with pre-treatment RVO patients (56.0±18.0 μm vs. 67.9±16.9 μm, respectively; P=0.02). Mean WLR in pre-treatment RVO patients was 0.47±0.19, showing an increase to 0.63±0.23 3 months after treatment (P=0.037). No significant difference was found in arteriolar external diameter between normotensive, pre-treatment, and post-treatment subjects. CONCLUSION Treatment with a DEX implant in RVO patients led to significant improvements in both VA and CMT. These changes were accompanied by reductions in arteriolar lumen diameter, which could contribute to decreased capillary leakage and macular swelling.
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Affiliation(s)
- Francesco Semeraro
- 1 Eye Clinic, Department of Neurological and Vision Sciences, University of Brescia , Brescia, Italy
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Abcouwer SF, Gardner TW. Diabetic retinopathy: loss of neuroretinal adaptation to the diabetic metabolic environment. Ann N Y Acad Sci 2014; 1311:174-90. [PMID: 24673341 DOI: 10.1111/nyas.12412] [Citation(s) in RCA: 162] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy (DR) impairs vision of patients with type 1 and type 2 diabetes, associated with vascular dysfunction and occlusion, retinal edema, hemorrhage, and inappropriate growth of new blood vessels. The recent success of biologic treatments targeting vascular endothelial growth factor (VEGF) demonstrates that treating the vascular aspects in the later stages of the disease can preserve vision in many patients. It would also be highly desirable to prevent the onset of the disease or arrest its progression at a stage preceding the appearance of overt microvascular pathologies. The progression of DR is not necessarily linear but may follow a series of steps that evolve over the course of multiple years. Abundant data suggest that diabetes affects the entire neurovascular unit of the retina, with an early loss of neurovascular coupling, gradual neurodegeneration, gliosis, and neuroinflammation occurring before observable vascular pathologies. In this article, we consider the pathology of DR from the point of view that diabetes causes measurable dysfunctions in the complex integral network of cell types that produce and maintain human vision.
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Affiliation(s)
- Steven F Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, Michigan
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Pei L, Yang G, Jiang J, Jiang R, Deng Q, Chen B, Gan X. Expression of aquaporins in prostate and seminal vesicles of diabetic rats. J Sex Med 2013; 10:2975-85. [PMID: 23981690 DOI: 10.1111/jsm.12276] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Aquaporins (AQPs) are membrane proteins that facilitate the movement of water and many small solutes across biological membranes. Seminal fluid is primarily produced by prostate and seminal vesicles, and its production may potentially be mediated by many mechanisms related to transudation of fluid. Epidemiological data suggest that semen volume in diabetic men is significantly less than in nondiabetic men. AIM To investigate the change in volume of secretions of the prostate and seminal vesicles in diabetic rats and its association with the expression of AQPs 1-4. METHODS Twenty male Sprague Dawley rats were randomly divided among 4- and 6-week diabetic groups and 4- and 6-week control groups. Prostate and seminal vesicle secretions were collected and measured, and levels of expression of AQPs 1-4 were determined by immunohistochemical study and Western blot. MAIN OUTCOME MEASURES The levels of expression of AQPs 1-4 were determined in the prostate and seminal vesicles of diabetic rats by Western blot and immunohistochemical study. RESULTS Plasma glucose was significantly higher in diabetic model groups than in controls (P < 0.05). The weights of secretions of the prostate and seminal vesicles were significantly lower in diabetic model groups (P < 0.05). The levels of expression of AQPs 1 and 4 in seminal vesicles were significantly lower in diabetic model groups (P < 0.05). There was no difference in the level of expression of AQP3 in seminal vesicles among the groups. The levels of expression of AQPs 1, 3, and 4 in prostate were significantly lower in diabetic model groups (P < 0.05). AQP2 was not detectable in the prostate or seminal vesicles of any of the groups. CONCLUSIONS Decreased weight of prostate secretions in diabetic rats may be partly due to decreased levels of AQPs 1, 3, and 4 in prostatic tissue. Decreased weight of seminal vesicle secretions in diabetic rats may be partly due to decreased levels of AQP1 and AQP4 in seminal vesicles. There is no relationship between the expression of AQPs 1-4 and the duration of disease.
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Affiliation(s)
- Lijun Pei
- Department of Nuclear Medicine, Affiliated Hospital, Luzhou Medical College, Luzhou, China
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Klaassen I, Van Noorden CJF, Schlingemann RO. Molecular basis of the inner blood-retinal barrier and its breakdown in diabetic macular edema and other pathological conditions. Prog Retin Eye Res 2013; 34:19-48. [PMID: 23416119 DOI: 10.1016/j.preteyeres.2013.02.001] [Citation(s) in RCA: 465] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 12/19/2012] [Accepted: 02/01/2013] [Indexed: 12/16/2022]
Abstract
Breakdown of the inner endothelial blood-retinal barrier (BRB), as occurs in diabetic retinopathy, age-related macular degeneration, retinal vein occlusions, uveitis and other chronic retinal diseases, results in vasogenic edema and neural tissue damage, causing loss of vision. The central mechanism of altered BRB function is a change in the permeability characteristics of retinal endothelial cells caused by elevated levels of growth factors, cytokines, advanced glycation end products, inflammation, hyperglycemia and loss of pericytes. Subsequently, paracellular but also transcellular transport across the retinal vascular wall increases via opening of endothelial intercellular junctions and qualitative and quantitative changes in endothelial caveolar transcellular transport, respectively. Functional changes in pericytes and astrocytes, as well as structural changes in the composition of the endothelial glycocalyx and the basal lamina around BRB endothelium further facilitate BRB leakage. As Starling's rules apply, active transcellular transport of plasma proteins by the BRB endothelial cells causing increased interstitial osmotic pressure is probably the main factor in the formation of macular edema. The understanding of the complex cellular and molecular processes involved in BRB leakage has grown rapidly in recent years. Although appropriate animal models for human conditions like diabetic macular edema are lacking, these insights have provided tools for rational design of drugs aimed at restoring the BRB as well as for design of effective transport of drugs across the BRB, to treat the chronic retinal diseases such as diabetic macular edema that affect the quality-of-life of millions of patients.
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Affiliation(s)
- Ingeborg Klaassen
- Ocular Angiogenesis Group, Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Abstract
An essential requirement for adequate organ performance is the formation of permeability barriers that separate and maintain compartments of distinctive structure and function. The endothelial cell lining of the vasculature defines a semipermeable barrier between the blood and interstitial spaces of all organs. Disruption of the endothelial cell barrier can result in increased permeability and vascular leak. These effects are associated with multiple systemic disease processes and can accompany acute tissue responses to injury. The mechanisms that control barrier function are complex and their full understanding requires a multidisciplinary approach. The use of in vivo permeability data often complements molecular findings and adds power to the studies. The interaction of multiple cell types and tissues present only in mammalian models allows for testing of hypothesis and establishing the physiological significance of the results. In this chapter we describe simple methods that can be used systematically to measure the permeability profile of several organs.
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Lai AKW, Lo ACY. Animal models of diabetic retinopathy: summary and comparison. J Diabetes Res 2013; 2013:106594. [PMID: 24286086 PMCID: PMC3826427 DOI: 10.1155/2013/106594] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 09/02/2013] [Accepted: 09/02/2013] [Indexed: 12/16/2022] Open
Abstract
Diabetic retinopathy (DR) is a microvascular complication associated with chronic exposure to hyperglycemia and is a major cause of blindness worldwide. Although clinical assessment and retinal autopsy of diabetic patients provide information on the features and progression of DR, its underlying pathophysiological mechanism cannot be deduced. In order to have a better understanding of the development of DR at the molecular and cellular levels, a variety of animal models have been developed. They include pharmacological induction of hyperglycemia and spontaneous diabetic rodents as well as models of angiogenesis without diabetes (to compensate for the absence of proliferative DR symptoms). In this review, we summarize the existing protocols to induce diabetes using STZ. We also describe and compare the pathological presentations, in both morphological and functional aspects, of the currently available DR animal models. The advantages and disadvantages of using different animals, ranging from zebrafish, rodents to other higher-order mammals, are also discussed. Until now, there is no single model that displays all the clinical features of DR as seen in human. Yet, with the understanding of the pathological findings in these animal models, researchers can select the most suitable models for mechanistic studies or drug screening.
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Affiliation(s)
- Angela Ka Wai Lai
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Amy C. Y. Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Research Center of Heart, Brain, Hormone and Healthy Aging, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- *Amy C. Y. Lo:
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