1
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Remote Ischemic Post-Conditioning Therapy is Protective in Mouse Model of Traumatic Optic Neuropathy. Neuromolecular Med 2020; 23:371-382. [PMID: 33185833 DOI: 10.1007/s12017-020-08631-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 10/30/2020] [Indexed: 10/23/2022]
Abstract
Traumatic optic neuropathy (TON) is characterized by visual dysfunction after indirect or direct injury to the optic nerve following blunt head trauma. TON is associated with increased oxidative stress and inflammation resulting in retinal ganglion cell (RGC) death. Remote ischemic post-conditioning (RIC) has been shown to enhance endogenous protective mechanisms in diverse disease models including stroke, vascular cognitive impairment (VCI), retinal injury and optic nerve injury. However, the protective mechanisms underlying the improvement of retinal function and RGC survival after RIC treatment remain unclear. Here, we hypothesized that RIC therapy may be protective following TON by preventing RGC death, oxidative insult and inflammation in the mouse retina. To carry out the study, mice were divided in three different groups (Control, TON and TON + RIC). We harvested retinal tissue 5 days after TON induction for western blotting and histochemical analysis. We observed increased TON-induced retinal cell death compared with controls by cleaved caspase-3 immunohistochemistry. Furthermore, the TON cohort demonstrated increased TUNEL positive cells which were significantly attenuated by RIC. Immunofluorescence data showed that oxidative stress markers dihydroethidium (DHE), NOX-2 and nitrotyrosine expression were elevated in the TON group relative to controls and RIC therapy significantly reduced the expression level of these markers. Next, we found that the proinflammatory cytokine TNF-α was increased and anti-inflammatory IL-10 was decreased in plasma of TON animals, and RIC therapy reversed this expression level. Interestingly, western blotting of retinal tissue showed that RGC marker Brn3a and tight junction proteins (ZO-1 and Occludin), and AMPKα1 expression were downregulated in the TON group compared to controls. However, RIC significantly increased the expression levels of these proteins. Together these data suggest that RIC therapy activates endogenous protective mechanisms which may attenuate TON-induced oxidative stress and inflammation, and improves BRB integrity.
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2
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Paz MC, Barcelona PF, Subirada PV, Ridano ME, Chiabrando GA, Castro C, Sánchez MC. Metabolic Syndrome Triggered by Fructose Diet Impairs Neuronal Function and Vascular Integrity in ApoE-KO Mouse Retinas: Implications of Autophagy Deficient Activation. Front Cell Dev Biol 2020; 8:573987. [PMID: 33154969 PMCID: PMC7587139 DOI: 10.3389/fcell.2020.573987] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/11/2020] [Indexed: 12/05/2022] Open
Abstract
Metabolic syndrome is a disorder characterized by a constellation of clinical findings such as elevated blood glucose, hyperinsulinemia, dyslipidemia, hypertension, and obesity. A positive correlation has been found between metabolic syndrome or its components and retinopathy, mainly at microvascular level, in patients without a history of diabetes. Here, we extend the investigations beyond the vascular component analyzing functional changes as well as neuronal and glial response in retinas of Apolipoprotein E knockout (ApoE-KO) mice fed with 10% w/v fructose diet. Given that autophagy dysfunction is implicated in retinal diseases related to hyperglycemia and dyslipidemia, the activation of this pathway was also analyzed. Two months of fructose intake triggered metabolic derangements in ApoE-KO mice characterized by dyslipidemia, hyperglycemia and hyperinsulinemia. An increased number of TUNEL positive cells, in addition to the ganglion cell layer, was observed in the inner nuclear layer in retina. Vascular permeability, evidenced by albumin–Evans blue leakage and extravasation of albumin was also detected. Furthermore, a significant decrease of the glial fibrillary acidic protein expression was confirmed by Western blot analysis. Absence of both Müller cell gliosis and pro-angiogenic response was also demonstrated. Finally, retinas of ApoE-KO FD mice showed defective autophagy activation as judged by LC3B mRNA and p62 protein levels correlating with the increased cell death. These results demonstrated that FD induced in ApoE-KO mice biochemical alterations compatible with metabolic syndrome associated with neuronal impairment and mild vascular alterations in the retina.
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Affiliation(s)
- María C Paz
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Pablo F Barcelona
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Paula V Subirada
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Magali E Ridano
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Gustavo A Chiabrando
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
| | - Claudia Castro
- Instituto de Medicina y Biología Experimental de Cuyo, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - María C Sánchez
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.,Centro de Investigaciones en Bioquímica Clínica e Inmunología, Consejo Nacional de Investigaciones Científicas y Técnicas, Córdoba, Argentina
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3
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Zhao L, Liao Q, Zhang Y, Tan S, Li S, Ke T. Ischemic Postconditioning Mitigates Retinopathy in Tree Shrews with Diabetic Cerebral Ischemia. J Diabetes Res 2020; 2020:6286571. [PMID: 32104713 PMCID: PMC7037873 DOI: 10.1155/2020/6286571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 01/04/2020] [Accepted: 01/17/2020] [Indexed: 12/25/2022] Open
Abstract
Ischemic postconditioning (PC) is proved to efficiently protect diabetic patients with acute myocardial infarction from ischemia-reperfusion injury. We aimed to explore the protective roles of ischemic PC on diabetic retinopathy in tree shrews with diabetic cerebral ischemia. A diabetic tree shrew model was established through high-fat diet feeding combined with streptozotocin (STZ) injection, while cortical thrombotic cerebral ischemia was induced photochemically. Tree shrews were divided into the normal control group, sham operation group, diabetes mellitus group, diabetes mellitus+cerebral ischemia group, and diabetes mellitus+cerebral ischemia+PC group (in which the tree shrews with diabetic cerebral ischemia were treated with ischemic PC). H&E staining was used to examine the pathological changes in the retina, and immunohistochemistry was performed to determine the retinal expression of VEGF (vascular endothelial growth factor). The modeling resulted in 77% tree shrews with diabetes. Ischemic PC reduced the blood glucose levels in the tree shrews with diabetic cerebral ischemia. Tree shrews with diabetes had thinned retina with disordered structures, and these pathological changes were aggravated after cerebral ischemia. The retinopathy was alleviated after ischemic PC. Retina expression of VEGF was mainly distributed in the ganglion cell layer in tree shrews. Diabetes and cerebral ischemia increased retinal VEGF expression in a step-wise manner, while additional ischemic PC reduced retinal VEGF expression. Therefore, ischemic PC effectively alleviates retinopathy in tree shrews with diabetic cerebral ischemia, and this effect is associated with reduced retinal VEGF expression.
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Affiliation(s)
- Ling Zhao
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Yunnan 650101, China
| | - Qiwei Liao
- Department of Cardiology, The Yan-an Affiliated Hospital of Kunming Medical University, Yunnan 650051, China
| | - Yueting Zhang
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Yunnan 650101, China
| | - Shufen Tan
- Department of Gynecologic Oncology, The Third Affiliated Hospital of Kunming Medical University, Yunnan 650101, China
| | - Shuqing Li
- Department of Pathophysiology, Kunming Medical University, Yunnan 650050, China
| | - Tingyu Ke
- Department of Endocrinology, The Second Affiliated Hospital of Kunming Medical University, Yunnan 650101, China
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4
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Critical Role of Monocyte Recruitment in Optic Nerve Damage Induced by Experimental Optic Neuritis. Mol Neurobiol 2019; 56:7458-7472. [PMID: 31044366 DOI: 10.1007/s12035-019-1608-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 04/12/2019] [Indexed: 12/13/2022]
Abstract
Neuroinflammatory diseases are characterized by blood-brain barrier disruption (BBB) and leukocyte infiltration. We investigated the involvement of monocyte recruitment in visual pathway damage provoked by primary optic neuritis (ON) induced by a microinjection of bacterial lipopolysaccharide (LPS) into the optic nerve from male Wistar rats. Increased Evans blue extravasation and cellularity were observed at 6 h post-LPS injection. In WT-GFPþ/WT chimeric rat optic nerves, the presence of GFP(+) neutrophils and GFP(+) monocytes, and in wild-type rat optic nerves, an increase in CD11b+CD45low and CD11b+CD45high cell number, were observed at 24 h post-LPS. Gamma-irradiation did not affect the increase in BBB permeability, but significantly lessened the decrease in pupil light reflex (PLR), and retinal ganglion cell (RGC) number induced by LPS. At 6 h post-LPS, an increase in chemokine (C-C motif) ligand 2 (CCL2) immunoreactivity co-localized with neutrophils (but not microglia/macrophages or astrocytes) was observed, while at 24 h post-injection, an increase in Iba-1-immunoreactivity and its co-localization with CCL2 became evident. The co-injection of LPS with bindarit (a CCL2 synthesis inhibitor) lessened the effect of LPS on PLR, and RGC loss. The treatment with etoposide or gadolinium chloride that significantly decreased peripheral monocyte (but not neutrophil or lymphocyte) percentage decreased the effect of LPS on PLR, and RGC number. Moreover, a negative correlation between PRL and monocyte (but not lymphocyte or neutrophil) percentage was observed at 7 days post-LPS. Taken together, these results support that monocytes are key players in the initial events that take place during primary ON.
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5
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Ali SA, Zaitone SA, Dessouki AA, Ali AA. Pregabalin affords retinal neuroprotection in diabetic rats: Suppression of retinal glutamate, microglia cell expression and apoptotic cell death. Exp Eye Res 2019; 184:78-90. [PMID: 31002823 DOI: 10.1016/j.exer.2019.04.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 02/25/2019] [Accepted: 04/15/2019] [Indexed: 01/22/2023]
Abstract
Pregabalin is the first drug to receive FDA approval for treating diabetic neuropathic pain. This study investigated the neuroprotective effect of pregabalin in an experimental model of diabetic retinopathy and tested some possible mechanisms underlying the putative neuroprotective effect. Male Wistar rats received streptozotocin (45 mg/kg) to induce type 1 diabetes mellitus. After two weeks, a course of pregabalin (3, 10 and 30 mg/kg) has been launched for five consecutive weeks. Retinal expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) was estimated by real-time PCR and retinal glutamate content was also estimated. Further, retinal caspase-3 immunoblotting and DNA fragmentation assays determined the degree of apoptosis. Pregabalin improved histopathological abnormalities in diabetic retinas and suppressed the diabetes-enhanced retinal expression of IL-1β, TNF-α, CD11b (a surface marker for microglia) while attenuated expression of caspase-3 and DNA fragmentation versus the diabetic group. In addition, diabetic rats treated with pregabalin displayed reductions in retinal glutamate, nitric oxide and malondialdehyde (MDA) and enhanced reduced glutathione (GSH) content versus the diabetic controls. Furthermore, pregabalin enhanced the histopathological picture and reduced fibrosis in the optic nerve of diabetic rats in addition to suppression of the content of the glia fibrillary acidic protein. The findings provide the first evidence demonstrating that pregabalin alleviates retinal neuroinflammation, apoptosis and oxidative stress in an experimental type 1 diabetes mellitus. Therefore, pregabalin might serve as a potential therapy for retinopathy after adequate clinical research.
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Affiliation(s)
| | - Sawsan A Zaitone
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia, 41522, Egypt; Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia.
| | - Amina A Dessouki
- Department of Pathology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt
| | - Azaa A Ali
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (girls), Al-Azhar University, Cairo, Egypt
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6
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Ren C, Wu H, Li D, Yang Y, Gao Y, Jizhang Y, Liu D, Ji X, Zhang X. Remote Ischemic Conditioning Protects Diabetic Retinopathy in Streptozotocin-induced Diabetic Rats via Anti-Inflammation and Antioxidation. Aging Dis 2018; 9:1122-1133. [PMID: 30574423 PMCID: PMC6284762 DOI: 10.14336/ad.2018.0711] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 07/11/2018] [Indexed: 12/13/2022] Open
Abstract
Ischemic conditioning inhibits oxidative stress and inflammatory response in diabetes. However, whether limb remote ischemic conditioning (LRIC) has beneficial effects on diabetic retinopathy (DR) remains unknown. This study aims to investigate the protective effects of LRIC in retinal ganglion cell in streptozotocin (STZ) induced Type 1 diabetic rats. A total of 48 healthy male Sprague-Dawley (200-220g) rats were randomly assigned to the normal group, normal+LRIC group, diabetes mellitus (DM) group and DM+LRIC group. Streptozotocin (STZ, 60 mg/kg) was intraperitoneally injected into the rats to establish the diabetic model. LRIC was conducted by tightening a tourniquet around the upper thigh and releasing for three cycles daily (10 mins x 3 cycles). Retinas were harvested after 12 weeks of LRIC treatment for histopathologic, Western blot and ELISA analysis. Plasma were collected at the same time for ELISA analysis. LRIC alleviated diabetic retinopathy symptoms as evidenced by the increased number of retinal ganglion cells (P<0.01) and decreased glial fibrillary acidic protein (GFAP) expression level (P<0.01) in the rat retina. LRIC in DM rats exhibited anti-inflammatory and antioxidative effects as confirmed by the down-regulation of pro-inflammatory cytokine: interleukin-6 (IL-6), and the up-regulation of antioxidants: superoxide dismutase (SOD), and glutathione (GSH)/oxidized glutathione (GSSG). Furthermore, LRIC significantly downregulated VEGF protein expression in the retina (P<0.01). These results suggest that the antioxidative and anti-inflammatory activities of LRIC may be important mechanisms involved in the protective effect of LRIC in STZ-induced diabetic rats.
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Affiliation(s)
- Changhong Ren
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,5Center of Stroke, Beijing Institute for Brain Disorder, Beijing 100069, China
| | - Hang Wu
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,2Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Dongjie Li
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,2Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yong Yang
- 3Department of Herbal Formula Science Medicine, Chinese Medicine College, Beijing University of Chinese Medicine, Beijing, China
| | - Yuan Gao
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,2Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Yunneng Jizhang
- 4Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, USA
| | - Dachuan Liu
- 2Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xunming Ji
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,5Center of Stroke, Beijing Institute for Brain Disorder, Beijing 100069, China
| | - Xuxiang Zhang
- 1Beijing Key Laboratory of Hypoxia Conditioning Translational Medicine, Beijing, China.,2Department of Ophthalmology, Xuanwu Hospital, Capital Medical University, Beijing, China
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7
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Hammoum I, Benlarbi M, Dellaa A, Kahloun R, Messaoud R, Amara S, Azaiz R, Charfeddine R, Dogui M, Khairallah M, Lukáts Á, Ben Chaouacha-Chekir R. Retinal dysfunction parallels morphologic alterations and precede clinically detectable vascular alterations in Meriones shawi, a model of type 2 diabetes. Exp Eye Res 2018; 176:174-187. [PMID: 30009825 DOI: 10.1016/j.exer.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/19/2018] [Accepted: 07/05/2018] [Indexed: 12/22/2022]
Abstract
Diabetic retinopathy is a major cause of reduced visual acuity and acquired blindness. The aim of this work was to analyze functional and vascular changes in diabetic Meriones shawi (M.sh) an animal model of metabolic syndrome and type 2 diabetes. The animals were divided into four groups. Two groups were fed a high fat diet (HFD) for 3 and 7 months, two other groups served as age-matched controls. Retinal function was assessed using full field electroretinogram (Ff-ERG). Retinal thickness and vasculature were examined by optical coherence tomography, eye fundus and fluorescein angiography. Immunohistochemistry was used to examine key proteins of glutamate metabolism and synaptic transmission. Diabetic animals exhibited significantly delayed scotopic and photopic ERG responses and decreases in scotopic and photopic a- and b-wave amplitudes at both time points. Furthermore, a decrease of the amplitude of the flicker response and variable changes in the scotopic and photopic oscillatory potentials was reported. A significant decrease in retinal thickness was observed. No evident change in the visual streak area and no sign of vascular abnormality was present; however, some exudates in the periphery were visible in 7 months diabetic animals. Imunohistochemistry detected a decrease in the expression of glutamate synthetase, vesicular glutamate transporter 1 and synaptophysin proteins. Results indicate that a significant retinal dysfunction was present in the HFD induced diabetes involving both rod and cone pathways and this dysfunction correlate well with the morphological abnormalities reported previously. Furthermore, neurodegeneration and abnormalities in retinal function occur before vascular alterations would be detectable in diabetic M.sh.
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Affiliation(s)
- Imane Hammoum
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia; Faculty of Sciences of Tunis, El Manar University (UTM), Tunis, Tunisia
| | - Maha Benlarbi
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Ahmed Dellaa
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia
| | - Rim Kahloun
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Riadh Messaoud
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Soumaya Amara
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Rached Azaiz
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Ridha Charfeddine
- UNIMED Pharmaceutical Industry, Industrial Area Kalaa Kebira, Sousse, Tunisia
| | - Mohamed Dogui
- Service of Functional Explorations of the Nervous System, Sahloul University Hospital, Sousse, Tunisia
| | - Moncef Khairallah
- Service of Ophtalmology, Fattouma Bourguiba University Hospital, Monastir, Tunisia
| | - Ákos Lukáts
- Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary
| | - Rafika Ben Chaouacha-Chekir
- Laboratory of Physiopathology, Food and Biomolecules (PAB) of the High Institute of Biotechnology, Sidi Thabet (ISBST), Univ Manouba (UMA), BiotechPole Sidi Thabet, Tunisia.
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8
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Rehni AK, Dave KR. Ameliorative potential of conditioning on ischemia-reperfusion injury in diabetes. CONDITIONING MEDICINE 2018; 1:105-115. [PMID: 29795806 PMCID: PMC5962288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Diabetes is a serious metabolic disease characterized by hyperglycemia. Diabetes also leads to several long-term secondary complications. Cardiovascular disease is an important complication of diabetes and is a major contributor to morbidity and mortality in diabetic subjects. The discovery of conditioning-induced ischemic or anoxic tolerance has led to the demonstration of the protective potential of conditioning as a treatment strategy to mitigate ischemia-reperfusion injury. Diabetes modulates multiple metabolic pathways and signal transduction cascades. Some of these pathways may overlap with mechanisms that mediate the beneficial effects of conditioning from the body's reaction to a sublethal insult, indicating the possibility of a potential interaction between diabetes and conditioning. Studies demonstrate that diabetes abrogates the ameliorative effect of various forms of conditioning, such as ischemic preconditioning, ischemic postconditioning, remote ischemic conditioning and pharmacological conditioning, on ischemia-reperfusion injury in various animal models. Moreover, drugs used to treat diabetes may have a potential impact on protection afforded by conditioning from ischemic injury. Studies also indicate a potential impact of various anti-diabetic drugs on conditioning-induced protection. Overall, the literature suggests that a better understanding of the overlap among pathways activated by diabetes and those involved in induction of ischemia tolerance may help identify ideal conditioning paradigms to protect diabetic subjects from ischemic injury.
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Affiliation(s)
- Ashish K. Rehni
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | - Kunjan R. Dave
- Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
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9
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Gidday JM. Adaptive Plasticity in the Retina: Protection Against Acute Injury and Neurodegenerative Disease by Conditioning Stimuli. CONDITIONING MEDICINE 2018; 1:85-97. [PMID: 31423482 PMCID: PMC6696944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Although both preclinical and clinical conditioning studies in heart and brain lead the field of conditioning medicine, investigations of retinal conditioning still number more than 100. In this brief review, we highlight findings to date from animal and cell culture models of conditioning that provide demonstrated protection in acute and chronic retinal injury and disease models. The multitude of stimuli used to condition the retina, the signaling mediators and pathways identified, and the injury- and disease-resilient phenotypes documented are discussed herein, along with our recommendations for the kinds of studies needed to continue to advance this promising field. In our view, the robust protection afforded by these adaptive epigenetic responses to conditioning stress provides significant incentives for both furthering our investment in bench research and underwriting clinical trials, so that the full potential of this therapy can be realized.
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Affiliation(s)
- Jeffrey M Gidday
- Departments of Ophthalmology, Physiology, and the Neuroscience Center of Excellence, Louisiana State University School of Medicine, New Orleans, LA 70112
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10
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Iliescu DA, Ciubotaru A, Ghiţă MA, Dumitru A, Zăgrean L. Effect of sevoflurane preconditioning on light-induced retinal damage in diabetic rats. Rom J Ophthalmol 2018; 62:24-33. [PMID: 29796431 PMCID: PMC5959021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/15/2018] [Indexed: 11/29/2022] Open
Abstract
Hyperglycemia and bright light are powerful stress agents that produce an enhanced retinal damage, when simultaneously acting on retina. Previous studies have shown that preconditioning with sevoflurane anesthesia offers a certain degree of protection to retinal cells against light damage. The objective of this study was to explore the effect of sevoflurane anesthetic preconditioning on a model of light-induced retinal degeneration in diabetic rats. Wistar rats that were randomly divided into four groups: control (rats exposed to photostress), group 1 (rats exposed to photostress and sevoflurane preconditioning), group 2 (diabetic rats exposed to photostress), group 3 (diabetic rats exposed to photostress and sevoflurane preconditioning) were used for this experiment. We recorded basal electroretinogram (ERG), at 36 h and 14 days after photostress and performed histological analysis of the retina. Results showed that sevoflurane has a protective effect on light-induced neuroretinal degeneration proved by significantly less variations of the ERG before and after photostress. Diabetes appears to increase the damaging effect of photostress on retina and attenuate the protection provided by sevoflurane preconditioning.
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Affiliation(s)
- Daniela Adriana Iliescu
- Physiology Department, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
- Ophthalmology Department, "Dr. Carol Davila" Central Military University Emergency Hospital, Bucharest, Romania
| | - Alexandra Ciubotaru
- Physiology Department, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
| | - Mihai Aurelian Ghiţă
- Physiology Department, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
- Ophthalmology Department, University Emergency Hospital, Bucharest, Romania
| | - Adrian Dumitru
- Pathology Department, University Emergency Hospital, Bucharest, Romania
| | - Leon Zăgrean
- Physiology Department, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania
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11
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Yang D, So KF, Lo ACY. Lycium barbarum
polysaccharide extracts preserve retinal function and attenuate inner retinal neuronal damage in a mouse model of transient retinal ischaemia. Clin Exp Ophthalmol 2017; 45:717-729. [DOI: 10.1111/ceo.12950] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 02/11/2017] [Accepted: 03/20/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Di Yang
- Department of Ophthalmology, First Affiliated Hospital of Kunming Medical University; Kunming Medical University; Kunming Yunnan China
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong
| | - Kwok-Fai So
- 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 CY 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
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12
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Li MS, Xin M, Guo CL, Lin GM, Li J, Wu XG. Differential expression of breast cancer-resistance protein, lung resistance protein, and multidrug resistance protein 1 in retinas of streptozotocin-induced diabetic mice. Int J Ophthalmol 2017; 10:515-523. [PMID: 28503421 DOI: 10.18240/ijo.2017.04.03] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 01/13/2017] [Indexed: 11/23/2022] Open
Abstract
AIM To investigate the altering expression profiles of efflux transporters such as breast cancer-resistance protein (BCRP), lung resistance protein (LRP), and multidrug resistance protein 1 (MDR1) at the inner blood-retinal barrier (BRB) during the development of early diabetic retinopathy (DR) and/or aging in mice. METHODS Relative mRNA and protein expression profiles of these three efflux transporters in the retina during the development of early DR and/or aging in mice were examined. The differing expression profiles of Zonula occludens 1 (ZO-1) and vascular endothelial growth factor-A (VEGFA) in the retina as well as the perfusion characterization of fluorescein isothiocyanate (FITC)-dextran and Evans blue were examined to evaluate the integrity of the inner BRB. RESULTS There were significant alterations in these three efflux transporters' expression profiles in the mRNA and protein levels of the retina during the development of diabetes mellitus and/or aging. The development of early DR was confirmed by the expression profiles of ZO-1 and VEGFA in the retina as well as the compromised integrity of the inner BRB. CONCLUSION The expression profiles of some efflux transporters such as BCRP, LRP, and MDR1 in mice retina during diabetic and/or aging conditions are tested, and the attenuated expression of BCRP, LRP, and MDR1 along with the breakdown of the inner BRB is found, which may be linked to the pathogenesis of early DR.
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Affiliation(s)
- Meng-Shuang Li
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan 250022, Shandong Province, China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.,Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong Province, China
| | - Meng Xin
- Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong Province, China.,Department of Ophthalmology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai 264100, Shandong Province, China
| | - Chuan-Long Guo
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China
| | - Gui-Ming Lin
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan 250022, Shandong Province, China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China
| | - Jun Li
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China
| | - Xiang-Gen Wu
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan 250022, Shandong Province, China.,State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao 266071, Shandong Province, China.,Department of Pharmacy, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, Shandong Province, China
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Fan J, Alsarraf O, Chou CJ, Yates PW, Goodwin NC, Rice DS, Crosson CE. Ischemic preconditioning, retinal neuroprotection and histone deacetylase activities. Exp Eye Res 2016; 146:269-275. [PMID: 27060376 DOI: 10.1016/j.exer.2016.03.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 03/07/2016] [Accepted: 03/31/2016] [Indexed: 01/05/2023]
Abstract
Increased histone deacetylase (HDAC) activity and the resulting dysregulation of protein acetylation is an integral event in retinal degenerations associated with ischemia and ocular hypertension. This study investigates the role of preconditioning on the process of acetylation in ischemic retinal injury. Rat eyes were unilaterally subjected to retinal injury by 45 min of acute ischemia, and retinal neuroprotection induced by 5 min of an ischemic preconditioning (IPC) event. HDAC activity was evaluated by a fluorometric enzymatic assay with selective isoform inhibitors. Retinal localization of acetylated histone-H3 was determined by immunohistochemistry on retina cross sections. Cleaved caspase-3 level was evaluated by Western blots. Electroretinogram (ERG) analyses were used to assess differences in retinal function seven days following ischemic injury. In control eyes, analysis of HDAC isoforms demonstrated that HDAC1/2 accounted for 28.4 ± 1.6%, HDAC3 for 42.4 ± 1.5% and HDAC6 activity 27.3 ± 3.5% of total activity. Following ischemia, total Class-I HDAC activity increased by 21.2 ± 6.2%, and this increase resulted solely from a rise in HDAC1/2 activity. No change in HDAC3 activity was measured. Activity of Class-II HDACs and HDAC8 was negligible. IPC stimulus prior to ischemic injury also suppressed the rise in Class-I HDAC activity, cleaved caspase-3 levels, and increased acetylated histone-H3 in the retina. In control animals 7 days post ischemia, ERG a- and b-wave amplitudes were significantly reduced by 34.9 ± 3.1% and 42.4 ± 6.3%, respectively. In rats receiving an IPC stimulus, the ischemia-induced decline in ERG a- and b-wave amplitudes was blocked. Although multiple HDACs were detected in the retina, these studies provide evidence that hypoacetylation associated with ischemic injury results from the selective rise in HDAC1/2 activity and that neuroprotection induced by IPC is mediated in part by suppressing HDAC activity.
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Affiliation(s)
- Jie Fan
- 167 Ashley Avenue, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, 29425, USA.
| | - Oday Alsarraf
- 167 Ashley Avenue, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - C James Chou
- 167 Ashley Avenue, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Phillip W Yates
- 167 Ashley Avenue, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | | | - Dennis S Rice
- Lexicon Pharmaceuticals, The Woodlands, TX, 77381, USA
| | - Craig E Crosson
- 167 Ashley Avenue, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, 29425, USA
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14
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Angiopoietin 2 induces astrocyte apoptosis via αvβ5-integrin signaling in diabetic retinopathy. Cell Death Dis 2016; 7:e2101. [PMID: 26890140 PMCID: PMC5399183 DOI: 10.1038/cddis.2015.347] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 10/04/2015] [Accepted: 11/02/2015] [Indexed: 12/04/2022]
Abstract
The vascular leakage in diabetic retinopathy leads to macular edema and vision loss. Although astrocyte play an important role in regulating blood-brain barrier integrity in the brain, the precise role of astrocyte in blood-retinal barrier was yet to be elucidated. This study aimed to investigate the role of angiopoietin 2 (Ang2) in astrocyte loss and vascular leakage in the early streptozotocin-induced diabetic retinopathy. We demonstrated that vascular leakage occurred with astrocyte loss in early diabetic mice retina as Ang2 increased. The astrocyte loss and vascular leakage were inhibited by intravitreal injection of Ang2-neutralizing antibody. In vitro, Ang2 aggravated high glucose-induced astrocyte apoptosis via GSK-3β activation. Ang2 directly bound to αvβ5 integrin, which was abundant in astrocyte, and the blockade of αvβ5 integrin, in vitro, effectively attenuated Ang2-induced astrocyte apoptosis. In vivo, intravitreal injection of anti-αvβ5-integrin antibody inhibited astrocyte loss in early diabetic retinopathy. Taken together, Ang2 induced astrocyte apoptosis under high glucose via αvβ5-integrin/GSK-3β/β-catenin pathway. Therefore, we suggest that Ang2/integrin signaling could be a potential therapeutic target to prevent the vascular leakage by astrocyte loss in early diabetic retinopathy.
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15
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Gidday JM, Zhang L, Chiang CW, Zhu Y. Enhanced Retinal Ganglion Cell Survival in Glaucoma by Hypoxic Postconditioning After Disease Onset. Neurotherapeutics 2015; 12:502-14. [PMID: 25549850 PMCID: PMC4404439 DOI: 10.1007/s13311-014-0330-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The neuroprotective efficacy of adaptive epigenetics, wherein beneficial gene expression changes are induced by nonharmful "conditioning" stimuli, is now well established in several acute, preclinical central nervous system injury models. Recently, in a mouse model of glaucoma, we demonstrated retinal ganglion cell (RGC) protection by repetitively "preconditioning" with hypoxia prior to disease onset, indicating an epigenetic approach may also yield benefits in chronic neurodegenerative disease. Herein, we determined whether presenting the repetitive hypoxic stimulus after disease initiation [repetitive hypoxic "postconditioning" (RH-Post)] could afford similar functional and morphologic protection against glaucomatous RGC injury. Chronic elevations in intraocular pressure (IOP) were induced unilaterally in adult male C57BL/6 mice by episcleral vein ligation. Mice were randomized to an RH-Post [1 h of systemic hypoxia (11% oxygen) every other day, starting 4 days after IOP elevation] or an untreated control group. After 3 weeks of experimental glaucoma, the 21-27% reduction and 5-25% prolongation in flash visual-evoked potential amplitudes and latencies, respectively, and the 30% impairment in visual acuity were robustly improved in RH-Post-treated mice, as was the 17% loss in RGC soma number and 20% reduction in axon integrity. These protective effects were observed without RH-Post affecting IOP. The present findings demonstrate that functional and morphologic protection of RGCs can be realized by stimulating epigenetic responses during the early stages of disease, and thus constitute a new conceptual approach to glaucoma therapeutics.
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Affiliation(s)
- Jeffrey M Gidday
- Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, 63110, USA,
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16
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Gidday JM. Extending injury- and disease-resistant CNS phenotypes by repetitive epigenetic conditioning. Front Neurol 2015; 6:42. [PMID: 25784897 PMCID: PMC4345883 DOI: 10.3389/fneur.2015.00042] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 02/18/2015] [Indexed: 01/12/2023] Open
Abstract
Significant reductions in the extent of acute injury in the CNS can be achieved by exposure to different preconditioning stimuli, but the duration of the induced protective phenotype is typically short-lasting, and thus is deemed as limiting its clinical applicability. Extending the period over which such adaptive epigenetic changes persist – in effect, expanding conditioning’s “therapeutic window” – would significantly broaden the potential applications of such a treatment approach in patients. The frequency of the conditioning stimulus may hold the key. While transient (1–3 days) protection against CNS ischemic injury is well established preclinically following a single preconditioning stimulus, repetitively presenting preconditioning stimuli extends the duration of ischemic tolerance by many weeks. Moreover, repetitive intermittent postconditioning enhances post-ischemic recovery metrics and improves long-term survival. Intermittent conditioning is also efficacious for preventing or delaying injury in preclinical models of chronic neurodegenerative disease, and for promoting long-lasting functional improvements in a number of other pathologies as well. Although the detailed mechanisms underlying these protracted kinds of neuroplasticity remain largely unstudied, accumulating empirical evidence supports the contention that all of these adaptive phenotypes are epigenetically mediated. Going forward, additional preclinical demonstrations of the ability to induce sustained beneficial phenotypes that reduce the burden of acute and chronic neurodegeneration, and experimental interrogations of the regulatory constructs responsible for these epigenetic responses, will accelerate the identification of not only efficacious but also practical, adaptive epigenetics-based treatments for individuals with neurological disease.
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Affiliation(s)
- Jeffrey M Gidday
- Department of Neurosurgery, Washington University School of Medicine , St. Louis, MO , USA ; Department of Ophthalmology and Visual Sciences, Washington University School of Medicine , St. Louis, MO , USA ; Department of Cell Biology and Physiology, Washington University School of Medicine , St. Louis, MO , USA
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17
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Rosenstein RE, Fernandez DC. Induction of ischemic tolerance as a promising treatment against diabetic retinopathy. Neural Regen Res 2014; 9:1581-4. [PMID: 25368643 PMCID: PMC4211198 DOI: 10.4103/1673-5374.141782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2014] [Indexed: 12/17/2022] Open
Abstract
Diabetic retinopathy is a leading cause of acquired blindness, and it is the most common ischemic disorder of the retina. Available treatments are not very effective. Efforts to inhibit diabetic retinopathy have focused either on highly specific therapeutic approaches for pharmacologic targets or using genetic approaches to change expression of certain enzymes. However, it might be wise to choose innovative treatment modalities that act by multiple potential mechanisms. The resistance to ischemic injury, or ischemic tolerance, can be transiently induced by prior exposure to a non-injurious preconditioning stimulus. A complete functional and histologic protection against retinal ischemic damage can be achieved by previous preconditioning with non-damaging ischemia. In this review, we will discuss evidence that supports that ischemic conditioning could help avert the dreaded consequences that results from retinal diabetic damage.
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Affiliation(s)
- Ruth E Rosenstein
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Diego C Fernandez
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina ; Present address: Johns Hopkins University, Department of Biology, Baltimore, MD, USA
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18
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Dorfman D, Aranda ML, González Fleitas MF, Chianelli MS, Fernandez DC, Sande PH, Rosenstein RE. Environmental enrichment protects the retina from early diabetic damage in adult rats. PLoS One 2014; 9:e101829. [PMID: 25004165 PMCID: PMC4086948 DOI: 10.1371/journal.pone.0101829] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/11/2014] [Indexed: 11/19/2022] Open
Abstract
Diabetic retinopathy is a leading cause of reduced visual acuity and acquired blindness. Available treatments are not completely effective. We analyzed the effect of environmental enrichment on retinal damage induced by experimental diabetes in adult Wistar rats. Diabetes was induced by an intraperitoneal injection of streptozotocin. Three days after vehicle or streptozotocin injection, animals were housed in enriched environment or remained in a standard environment. Retinal function (electroretinogram, and oscillatory potentials), retinal morphology, blood-retinal barrier integrity, synaptophysin, astrocyte and Müller cell glial fibrillary acidic protein, vascular endothelial growth factor, tumor necrosis factor-α, and brain-derived neurotrophic factor levels, as well as lipid peroxidation were assessed in retina from diabetic animals housed in standard or enriched environment. Environmental enrichment preserved scotopic electroretinogram a-wave, b-wave and oscillatory potential amplitude, avoided albumin-Evan's blue leakage, prevented the decrease in retinal synaptophysin and astrocyte glial fibrillary acidic protein levels, the increase in Müller cell glial fibrillary acidic protein, vascular endothelial growth factor and tumor necrosis factor-α levels, as well as oxidative stress induced by diabetes. In addition, enriched environment prevented the decrease in retinal brain-derived neurotrophic factor levels induced by experimental diabetes. When environmental enrichment started 7 weeks after diabetes onset, retinal function was significantly preserved. These results indicate that enriched environment could attenuate the early diabetic damage in the retina from adult rats.
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Affiliation(s)
- Damián Dorfman
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Marcos L. Aranda
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - María Florencia González Fleitas
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Mónica S. Chianelli
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Diego C. Fernandez
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
- Laboratory of Histology, School of Medicine, University of Morón, Buenos Aires, Argentina
| | - Pablo H. Sande
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
| | - Ruth E. Rosenstein
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
- * E-mail:
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Cellular mechanisms of high mobility group 1 (HMGB-1) protein action in the diabetic retinopathy. PLoS One 2014; 9:e87574. [PMID: 24498140 PMCID: PMC3909191 DOI: 10.1371/journal.pone.0087574] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 12/22/2013] [Indexed: 01/14/2023] Open
Abstract
Diabetic retinopathy is one of the main microvascular complications of diabetes and remains one of the leading causes of blindness worldwide. Recent studies have revealed an important role of inflammatory and proangiogenic high mobility group 1 (HMGB-1) cytokine in diabetic retinopathy. To elucidate cellular mechanisms of HMGB-1 activity in the retina, we performed this study. The histological features of diabetic retinopathy include loss of blood-vessel pericytes and endothelial cells, as well as abnormal new blood vessel growth. To establish the role of HMGB-1 in vulnerability of endothelial cells and pericytes, cultures of these cells, or co-cultures with glial cells, were treated with HMGB-1 and assessed for survival after 24 hours. The expression levels of the cytokines, chemokines, and cell adhesion molecules in glial and endothelial cells were tested by quantitative RT-PCR to evaluate changes in these cells after HMGB-1 treatment. Animal models of neovascularization were also used to study the role of HMGB-1 in the retina. We report that pericyte death is mediated by HMGB-1-induced cytotoxic activity of glial cells, while HMGB-1 can directly mediate death of endothelial cells. We also found that HMGB-1 affects endothelial cell activity. However, we did not observe a difference in the levels of neovascularization between HMGB-1-treated eyes compared to the control eyes, nor in the levels of proangiogenic cytokine VEGF-A expression between glial cells treated with HMGB-1 and control cells. Our data also indicate that HMGB-1 is not involved in retinal neovascularization in the oxygen-induced retinopathy model. Thus, our data suggest that retinal pericyte and endothelial injury and death in diabetic retinopathy may be due to HMGB-1-induced cytotoxic activity of glial cells as well as the direct effect of HMGB-1 on endothelial cells. At the same time, our findings indicate that HMGB-1 plays an insignificant role in retinal and choroidal neovascularization.
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Berkowitz BA, Bissig D, Dutczak O, Corbett S, North R, Roberts R. MRI biomarkers for evaluation of treatment efficacy in preclinical diabetic retinopathy. ACTA ACUST UNITED AC 2013; 7:393-403. [PMID: 23786440 DOI: 10.1517/17530059.2013.814639] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
INTRODUCTION One sober consequence of the current epidemic of diabetes mellitus is that an increasing number of people world-wide will partially or completely lose their sight to diabetic retinopathy. Clinically, the sight-threatening complications of diabetes are diagnosed and treated based on visible retinal lesions (e.g., dot-blot hemorrhages or retinal neovascularization). However, such anatomical microvascular lesions are slow to respond with treatment. Thus, there remains an urgent need for imaging biomarkers that are abnormal before retinal lesions are visibly apparent and are responsive to treatment. AREAS COVERED Here, the development of new MRI methods, such as manganese-enhanced MRI, for evaluating early diabetes-evoked retinal pathophysiology, and its usefulness in guiding new treatments for diabetic retinopathy are reviewed. EXPERT OPINION In diabetic retinopathy, not all important diagnostic and prognostic needs are well served by optical methods. In the absence of gross anatomy changes, critical times when drug intervention is most likely to be successful at reducing vision loss are missed by most light-based methods and thus provide little help in guiding diagnosis and treatment. For example, before clinical symptoms, is there an optimal time to intervene with drug therapy? Is a drug reaching its target? How does one assess optimal drug dose, schedule, and routes? How well do current experimental models mimic the clinical condition? As discussed herein, MRI is as an analytical tool for addressing these unmet needs. Future clinical applications of MRI can be envisioned such as in clinical trials to assess drug treatment efficacy, or as an adjunct approach to refine or clarify a difficult clinical case. New MRI-generated hypotheses about the pathogenesis of diabetic retinopathy and its treatment are discussed. In the coming years, a substantial growth in the development and application of MRI is expected to address relevant question in both the basic sciences and in the clinic.
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Affiliation(s)
- Bruce A Berkowitz
- Wayne State University, Department of Anatomy and Cell Biology, Detroit, MI, USA.
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Liu X, Sha O, Cho EYP. Remote ischemic postconditioning promotes the survival of retinal ganglion cells after optic nerve injury. J Mol Neurosci 2013; 51:639-46. [PMID: 23733254 DOI: 10.1007/s12031-013-0036-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 05/20/2013] [Indexed: 02/07/2023]
Abstract
Ischemic conditioning, the application of a mild ischemic stimulus to an ischemia-sensitive structure like the heart or brain either before (preconditioning) or after (postconditioning) its exposure to a lethal ischemic insult, is known to switch on endogenous protective mechanisms. However, most studies of its neuroprotective effect in the central nervous system (CNS) have focused on ischemic damage or related conditions like hypoxia, while its potential in treating other neural diseases remains uncertain. In particular, the recent discovery of remote ischemic postconditioning whereby mild ischemia applied to a region remote from the target after the main ischemic insult also confers protection offers an attractive paradigm to study its potential in other types of neural injury. Retinal ganglion cells damaged by optic nerve transection undergo extensive cell death. However, application of a series of mild ischemic/reperfusion cycles to the hind limb (limb remote ischemic postconditioning) at 10 min or 6 h after optic nerve cut was found to promote ganglion cell survival at 7 days post-injury, with the 10 min postconditioning still exerting protection at 14 days post-injury. Concomitant with the increased ganglion cell survival, 51 % more ganglion cells expressed the small heat shock protein HSP27, when remote ischemic postconditioning was performed at 10 min post-injury, as compared to the sham conditioning group. Our results highlight the potential of using remote ischemic postconditioning as a noninvasive neuroprotective strategy in different CNS disorders like spinal cord and traumatic brain injury.
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Affiliation(s)
- Xia Liu
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, China
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Ischemic conditioning protects from axoglial alterations of the optic pathway induced by experimental diabetes in rats. PLoS One 2012; 7:e51966. [PMID: 23284834 PMCID: PMC3527393 DOI: 10.1371/journal.pone.0051966] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 11/09/2012] [Indexed: 11/20/2022] Open
Abstract
Diabetic retinopathy is a leading cause of blindness. Visual function disorders have been demonstrated in diabetics even before the onset of retinopathy. At early stages of experimental diabetes, axoglial alterations occur at the distal portion of the optic nerve. Although ischemic conditioning can protect neurons and synaptic terminals against ischemic damage, there is no information on its ability to protect axons. We analyzed the effect of ischemic conditioning on the early axoglial alterations in the distal portion of the optic nerve induced by experimental diabetes. Diabetes was induced in Wistar rats by an intraperitoneal injection of streptozotocin. Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 5 min; this maneuver started 3 days after streptozotocin injection and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. The application of ischemia pulses prevented a deficit in the anterograde transport from the retina to the superior colliculus, as well as an increase in astrocyte reactivity, ultraestructural myelin alterations, and altered morphology of oligodendrocyte lineage in the optic nerve distal portion at early stages of experimental diabetes. Ischemia tolerance prevented a significant decrease of retinal glutamine synthetase activity induced by diabetes. These results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved axonal function and structure.
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Salido EM, Dorfman D, Bordone M, Chianelli MS, Sarmiento MIK, Aranda M, Rosenstein RE. Ischemic conditioning protects the rat retina in an experimental model of early type 2 diabetes. Exp Neurol 2012; 240:1-8. [PMID: 23153579 DOI: 10.1016/j.expneurol.2012.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 10/30/2012] [Accepted: 11/05/2012] [Indexed: 02/02/2023]
Abstract
Diabetic retinopathy is a leading cause of acquired blindness in adults, mostly affected by type 2 diabetes mellitus (T2DM). We have developed an experimental model of early T2DM in adult rats which mimics some features of human T2DM at its initial stages, and provokes significant retinal alterations. We investigated the effect of ischemic conditioning on retinal changes induced by the moderate metabolic derangement. For this purpose, adult male Wistar rats received a control diet or 30% sucrose in the drinking water, and 3 weeks after this treatment, animals were injected with vehicle or streptozotocin (STZ, 25mg/kg). Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 5 min; this maneuver started 3 weeks after vehicle or STZ injection and was weekly repeated in one eye, while control eyes were submitted to a sham procedure. Fasting and postprandial glycemia, and glucose, and insulin tolerance tests were analyzed. At 12 weeks of treatment, animals which received a sucrose-enriched diet and STZ showed significant differences in metabolic tests, as compared with control groups. Brief ischemia pulses in one eye and a sham procedure in the contralateral eye did not affect glucose metabolism in control or diabetic rats. Ischemic pulses reduced the decrease in the electroretinogram a-wave, b-wave, and oscillatory potential amplitude, and the increase in retinal lipid peroxidation, NOS activity, TNFα, Müller cells glial fibrillary acidic protein, and vascular endothelial growth factor levels observed in diabetic animals. In addition, ischemic conditioning prevented the decrease in retinal catalase activity induced by T2DM. These results indicate that induction of ischemic tolerance could constitute a fertile avenue for the development of new therapeutic strategies to treat diabetic retinopathy associated with T2DM.
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Affiliation(s)
- Ezequiel M Salido
- Laboratory of Retinal Neurochemistry and Experimental Ophthalmology, Department of Human Biochemistry, School of Medicine/CEFyBO, University of Buenos Aires/CONICET, Buenos Aires, Argentina
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Shi SY, Feng XM, Li Y, Li X, Chen XL. Expression of neuroglobin in ocular hypertension induced acute hypoxic-ischemic retinal injury in rats. Int J Ophthalmol 2011; 4:393-5. [PMID: 22553688 DOI: 10.3980/j.issn.2222-3959.2011.04.14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 06/28/2011] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the expression of neuroglobin (Ngb) in the retina of rats with ocular hypertension induced acute retinal hypoxic-ischemic injury. METHODS Seventy Wistar rats were divided into 7 groups randomly. The experimental model was induced by elevation of intraocular pressure via anterior chamber canula insertion in the left eyes and the fellow eyes were preserved as normal controls. The retinal tissues were taken at 1, 5, 10, 15, 20, 30 and 60 minutes after hypoxic-ischemia injury. Protein was extracted, and then analyzed by Western-blot method. SPSS was used for statistical analysis. RESULTS The time-depended expressions of Ngb were observed. The level of Ngb increased rapidly at 1 minute after ischemia and reached to the peak at 5 minutes, which had significant difference from that of control group (P<0.05). It kept in high level during 5-15 minutes (P<0.05), then decreased after 20 minutes till 60 minutes. There were no significant differences between experimental and control group in the latter period (P>0.05). CONCLUSION The expression of Ngb in retinal tissue increased rapidly after hypoxic-ischemic injury in rats, suggesting that Ngb may play an important role in the process of acute retinal hypoxic-ischemic injury.
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Affiliation(s)
- Shao-Yang Shi
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 11004, Liaoning Province, China
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