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Okonkwo ON, Agweye CT, Akanbi T. Neuroprotection for Nonarteritic Central Retinal Artery Occlusion: Lessons from Acute Ischemic Stroke. Clin Ophthalmol 2023; 17:1531-1543. [PMID: 37284058 PMCID: PMC10239763 DOI: 10.2147/opth.s403433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/19/2023] [Indexed: 06/08/2023] Open
Abstract
Nonarteritic central retinal artery occlusion (NA-CRAO) is a variant of acute ischemic stroke (AIS) and is a cause of sudden severe loss of vision. There are guidelines by the American Heart Association and the American Stroke Association for the care of CRAO patients. This review explores the basis of retinal neuroprotection for CRAO and its potential for improving the outcome of NA-CRAO. Recently, there have been significant advances in research into the use of neuroprotection to treat retinal diseases, including retinal detachment, age-related macular degeneration, and inherited retinal diseases. Also, neuroprotective research in AIS has been extensive, and newer drugs tested, including Uric acid, Nerinetide, and Otaplimastat, with promising results. Progress in cerebral neuroprotection after AIS offers hope for retinal neuroprotection after CRAO; and a possibility of extrapolating research findings from AIS into CRAO. Combining neuroprotection and thrombolysis can extend the therapeutic window for NA-CRAO treatment and potentially improve outcomes. Experimented neuroprotection for CRAO includes Angiopoietin (Comp Ang1), KUS 121, Gene therapy (XIAP), and hypothermia. Efforts in the field of neuroprotection for NA-CRAO should focus on better imaging to delineate the penumbra after an acute episode of NA-CRAO (using a combination of high-definition optical coherence angiography and electrophysiology). Also, research should explore details of pathophysiologic mechanisms involved in NA-CRAO, allowing for further neuroprotective intervention, and closing the gap between preclinical and clinical neuroprotection.
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Affiliation(s)
- Ogugua Ndubuisi Okonkwo
- Department of Ophthalmology, Eye Foundation Hospital and Eye Foundation Retina Institute, Ikeja, Lagos, Nigeria
| | - Chineze Thelma Agweye
- Department of Ophthalmology, University of Calabar and University of Calabar Teaching Hospital, Cross River, Nigeria
| | - Toyin Akanbi
- Department of Ophthalmology, Eye Foundation Hospital and Eye Foundation Retina Institute, Ikeja, Lagos, Nigeria
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2
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Siyanaki MRH, Azab MA, Lucke-Wold B. Traumatic Optic Neuropathy: Update on Management. ENCYCLOPEDIA 2023; 3:88-101. [PMID: 36718432 PMCID: PMC9884099 DOI: 10.3390/encyclopedia3010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Traumatic optic neuropathy is one of the causes of visual loss caused by blunt or penetrating head trauma and is classified as both direct and indirect. Clinical history and examination findings usually allow for the diagnosis of traumatic optic neuropathy. There is still controversy surrounding the management of traumatic optic neuropathy; some physicians advocate observation alone, while others recommend steroid therapy, surgery, or both. In this entry, we tried to highlight traumatic optic neuropathy's main pathophysiologic mechanisms with the most available updated treatment. Recent research suggests future therapies that may be helpful in traumatic optic neuropathy cases.
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Affiliation(s)
| | - Mohammed A. Azab
- Department of Neurosurgery, University of Cairo University, Cairo 12613, Egypt
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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3
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Traumatic optic neuropathy: a review of current studies. Neurosurg Rev 2022; 45:1895-1913. [PMID: 35034261 DOI: 10.1007/s10143-021-01717-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/26/2021] [Accepted: 12/09/2021] [Indexed: 10/24/2022]
Abstract
Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.
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4
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Research Progress of the Application of Hypothermia in the Eye. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3897168. [PMID: 33381263 PMCID: PMC7758138 DOI: 10.1155/2020/3897168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 02/07/2023]
Abstract
Hypothermia is widely used in the medical field to protect organs or tissues from damage. Different research fields have different explanations of the protection mechanism of hypothermia. Hypothermia is also widely used in the field of ophthalmology, for example, in the eye bank, the preservation of corneal tissue and the preservation of the eyeball. Low temperature can also be applied to some ophthalmic diseases, such as allergic conjunctivitis, retinal ischemia, and retinal hypoxia. It is used to relieve eye symptoms or reduce tissue damage. Hypothermic techniques have important applications in ophthalmic surgery, such as corneal refractive surgery, vitrectomy surgery, and ciliary body cryotherapy for end-stage glaucoma. Hypothermia can reduce the inflammation of the cornea and protect the retinal tissue. The eyeball is a complex organ, including collagen tissue of the eyeball wall and retinal nerve tissue and retinal blood vessels. The mechanism of low temperature protecting eye tissue is complicated. It is important to understand the mechanism of hypothermia and its applications in ophthalmology. This review introduces the mechanism of hypothermia and its application in the eye banks, eye diseases (allergic conjunctivitis, retinal ischemia, and hypoxia), and eye surgeries (corneal transplant surgery, corneal refractive surgery, and vitrectomy).
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5
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Jiang L, Wan W, Xun Y, Xiong L, Wu B, Xiang Y, Li Z, Zhu L, Ji Y, Yang P, Hu K. Effect of hypothermic perfusion on phacoemulsification in cataract patients complicated with uveitis: a randomised trial. BMC Ophthalmol 2020; 20:232. [PMID: 32546211 PMCID: PMC7298810 DOI: 10.1186/s12886-020-01507-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 06/05/2020] [Indexed: 11/18/2022] Open
Abstract
Background To evaluate the effectiveness and safety of hypothermic perfusion in the phacoemulsification of cataract caused by uveitis. Methods This was a prospective, single-masked, randomised, controlled clinical trial. One hundred and six patients with uveitis-associated cataract underwent phacoemulsification with perfusion fluid temperature at 4 °C (treatment group) or 24 °C (control group). Anterior chamber inflammation grade, corneal endothelial cell count, corneal thickness, macular fovea thickness, and intraocular pressure (IOP) were observed on the 1st day and 7th day after operation. Results The aqueous flare score was 0.83 ± 0.76 in the 4 °C group, which was lower than that in the 24 °C group (1.51 ± 1.02, p = 0.006) on the first day after operation. The aqueous cells score was lower in the 4 °C group (0.17 ± 0.38) than that in the 24 °C group (0.62 ± 0.94, p = 0.025). The mean corneal thickness of incision in the 4 °C group (907.66 ± 85.37 μm) was thinner than that in the 24 °C group (963.75 ± 103.81 μm, p = 0.005). Corneal endothelial cells density, macular fovea thickness, or percentage of transiently increased IOP showed no difference between the two groups (p > 0.05). There was no significant difference in all the main outcome parameters between the two groups on the 7th day after operation (p > 0.05). Conclusions Hypothermic perfusion in the phacoemulsification of uveitis-associated cataract is safe, and it can effectively inhibit anterior chamber inflammation and reduce the incisional corneal edema in the early postoperative stage. Trial registration The study was registered with the Chinese Clinical Trial Registry. (http://www.chictr.org.cn/, Registration Number: ChiCTR1800016145).
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Affiliation(s)
- Lu Jiang
- Chongqing Medical University, Chongqing, China
| | - Wenjuan Wan
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, China
| | - Yan Xun
- Chongqing Medical University, Chongqing, China
| | - Liang Xiong
- Chongqing Medical University, Chongqing, China
| | - Binge Wu
- The Second affiliated hospital of Baotou medical college, Baotou, Inner Mongolia Autonomous Region, China
| | | | - Zhouyu Li
- Chongqing Medical University, Chongqing, China
| | - Lu Zhu
- Chongqing Medical University, Chongqing, China
| | - Yan Ji
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, China
| | - Peizeng Yang
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, China
| | - Ke Hu
- Chongqing Medical University, Chongqing, China. .,The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology and Chongqing Eye Institute, Chongqing, China.
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Mueller-Buehl AM, Doepper H, Grauthoff S, Kiebler T, Peters L, Hurst J, Kuehn S, Bartz-Schmidt KU, Dick HB, Joachim SC, Schnichels S. Oxidative stress-induced retinal damage is prevented by mild hypothermia in an ex vivo model of cultivated porcine retinas. Clin Exp Ophthalmol 2020; 48:666-681. [PMID: 32077190 DOI: 10.1111/ceo.13731] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/15/2020] [Accepted: 02/17/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Hydrogen peroxide (H2 O2 ) can be used in vitro to simulate oxidative stress. In retinal organ cultures, H2 O2 induces strong neurodegeneration of the retina. It is known that oxidative stress plays a role in the development of several retinal diseases including glaucoma and ischemia. Thus, we investigated whether processes underlying oxidative stress can be prevented by hypothermia using an ex vivo organ culture model of porcine retinas. METHODS Porcine retinal explants were cultivated for 5 and 8 days. Oxidative stress was induced via 300 μM H2 O2 on day 1 for 3 hours. Hypothermia treatment at 30°C was applied simultaneously with H2 O2 , for 3 hours. Retinal ganglion cells (RGCs), apoptosis, bipolar and cholinergic amacrine cells, microglia and macroglia were evaluated immunohistologically. Apoptosis rate was additionally analysed via western blot. RESULTS Reduced apoptosis rates through hypothermia led to a preservation of RGCs (P < .001). Amacrine cells were rescued after hypothermia treatment (P = .17), whereas bipolar cells were only protected partly. Additionally, at 8 days, microglial response due to oxidative stress was completely counteracted via hypothermia (P < .001). CONCLUSIONS H2 O2 induced strong degenerative processes in porcine retinas. The role of oxidative stress in the progression of retinal diseases makes this ex vivo organ culture model suitable to investigate new therapeutic approaches. In the present study, the damaging effect of H2 O2 to several retinal cell types was counteracted or strongly alleviated through hypothermia treatment. Especially RGCs, which are affected in glaucoma disease, were protected due to a reduced apoptosis rate through hypothermia.
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Affiliation(s)
- Ana M Mueller-Buehl
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Hannah Doepper
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sven Grauthoff
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Tobias Kiebler
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Laura Peters
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - José Hurst
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Karl U Bartz-Schmidt
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - H Burkard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sven Schnichels
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
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7
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Kim S, Kang-Mieler JJ, Liu W, Wang Z, Yiu G, Teixeira LBC, Mieler WF, Thomasy SM. Safety and Biocompatibility of Aflibercept-Loaded Microsphere Thermo-Responsive Hydrogel Drug Delivery System in a Nonhuman Primate Model. Transl Vis Sci Technol 2020; 9:30. [PMID: 32742760 PMCID: PMC7354880 DOI: 10.1167/tvst.9.3.30] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Purpose To evaluate the safety and tolerability of a microsphere thermo-responsive hydrogel drug delivery system (DDS) loaded with aflibercept in a nonhuman primate model. Methods A sterile 50 µL of aflibercept-loaded microsphere thermo-responsive hydrogel-DDS (aflibercept-DDS) was injected intravitreally into the right eye of 10 healthy rhesus macaques. A complete ophthalmic examination, intraocular pressure (IOP) measurement, fundus photography, spectral-domain optical coherence tomography (SD-OCT), and electroretinogram were performed monthly for 6 months. One macaque was euthanized monthly, and the enucleated eyes were submitted for measurement of bioactive aflibercept concentrations. Four eyes were submitted for histopathology. Results Injected aflibercept-DDS was visualized in the vitreous until 6 months postinjection. No abnormalities were observed in the anterior segment, and IOP remained within normal range during the study period. A small number of cells were observed in the vitreous of some macaques, but otherwise the remainder of the posterior segment examination was normal. No significant changes in retinal architecture or function as assessed by SD-OCT and histology or full-field electroretinography, respectively, were observed. A mild, focal foreign body reaction around the injectate was observed with histology at 6 months postinjection. A mean of 2.1 ng/µL of aflibercept was measured in the vitreous. Conclusions Intravitreally injected aflibercept-DDS achieved controlled, sustained release of aflibercept with no adverse effects for up to 6 months in the eyes of healthy rhesus macaques. Translational Relevance Aflibercept-DDS may be a more effective method to deliver bioactive antivascular endothelial growth factor agents than current practice by reducing the frequency of intravitreal injections and providing controlled drug release.
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Affiliation(s)
- Soohyun Kim
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California -Davis, Davis, CA, USA
| | - Jennifer J Kang-Mieler
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Wenqiang Liu
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, IL, USA
| | - Zhe Wang
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California -Davis, Davis, CA, USA
| | - Glenn Yiu
- Department of Ophthalmology and Vision Science, School of Medicine, University of California-Davis, Davis, CA, USA
| | - Leandro B C Teixeira
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - William F Mieler
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California -Davis, Davis, CA, USA.,Department of Ophthalmology and Vision Science, School of Medicine, University of California-Davis, Davis, CA, USA
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8
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Species Differences in the Nutrition of Retinal Ganglion Cells among Mammals Frequently Used as Animal Models. Cells 2019; 8:cells8101254. [PMID: 31615137 PMCID: PMC6829614 DOI: 10.3390/cells8101254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 09/26/2019] [Accepted: 10/13/2019] [Indexed: 12/23/2022] Open
Abstract
The diffusion rate for proper nutrition of the inner retina depends mainly on four factors which are discussed in this review: 1. The diffusion distance between blood and retinal ganglion cells shows morphological variants in different mammalian species, namely a choroidal nutrition type, a retinal nutrition type, and a mixture of both types. 2. Low oxygen concentration levels in the inner retina force the diffusion of oxygen especially in the choroidal nutrition type. Other nutrients might be supplied by surrounding cells, mainly Müller cells. 3. Diffusion in the eye is influenced by the intraocular pressure, which is vital for the retinal ganglion cells but might also influence their proper function. Again, the nutrition types established might explain the differences in normal intraocular pressure levels among different species. 4. Temperature is a critical feature in the eye which has to be buffered to avoid neuronal damage. The most effective buffer system is the increased blood turnover in the choroid which has to be established in all species.
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Klemm P, Hurst J, Dias Blak M, Herrmann T, Melchinger M, Bartz-Schmidt KU, Zeck G, Schultheiss M, Spitzer MS, Schnichels S. Hypothermia protects retinal ganglion cells against hypoxia-induced cell death in a retina organ culture model. Clin Exp Ophthalmol 2019; 47:1043-1054. [PMID: 31152487 DOI: 10.1111/ceo.13565] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 05/23/2019] [Accepted: 05/28/2019] [Indexed: 12/01/2022]
Abstract
BACKGROUND Hypoxia contributes to retinal damage in several retinal diseases, including central retinal artery occlusion, with detrimental consequences like painless, monocular loss of vision. Currently, the treatment options are severely limited due to the short therapy window, as the neuronal cells, especially the retinal ganglion cells (RGCs), are irreversibly damaged within the first few hours. Hypothermia might be a possible treatment option or at least might increase the therapy window. METHODS To investigate the neuroprotective effect of hypothermia after retinal hypoxia, an easy-to-use ex vivo retinal hypoxia organ culture model developed in our laboratory was used that reliably induced retinal damage on a structural, molecular and functional level. The neuroprotective effect of hypothermia after retinal hypoxia was analysed using optical coherence tomography scans, histological stainings, quantitative real-time polymerase chain reaction, western blotting and microelectrode array recordings. RESULTS Two different hypothermic temperatures (30°C and 20°C) were evaluated, both exhibited strong neuroprotective effects. Most importantly, hypothermia increased RGC survival after retinal hypoxia. Furthermore, hypothermia counteracted the hypoxia-induced RGC death, reduced macroglia activation, attenuated retinal thinning and protected from loss of spontaneous RGC activity. CONCLUSIONS These results indicate that already a mild reduction in temperature protects the RGCs against damage and could function as a promising therapeutic option for hypoxic diseases.
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Affiliation(s)
- Patricia Klemm
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - José Hurst
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Matthias Dias Blak
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany.,Department of Ophthalmology, Klinikum Stuttgart, Stuttgart, Germany
| | - Thoralf Herrmann
- Department of Neurophysics, NMI Natural and Medical Sciences Institute, University of Tübingen, Reutlingen, Germany
| | - Marion Melchinger
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Karl U Bartz-Schmidt
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
| | - Günther Zeck
- Department of Neurophysics, NMI Natural and Medical Sciences Institute, University of Tübingen, Reutlingen, Germany
| | - Maximilian Schultheiss
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany.,Clinic for Ophthalmology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Martin S Spitzer
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany.,Clinic for Ophthalmology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Sven Schnichels
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Tübingen, Germany
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10
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Sun YJ, Ma S, Fan B, Wang Y, Wang SR, Li GY. Therapeutic hypothermia protects photoreceptors through activating Cirbp pathway. Neurochem Int 2019; 126:86-95. [DOI: 10.1016/j.neuint.2019.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/14/2019] [Accepted: 03/06/2019] [Indexed: 02/02/2023]
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11
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Maliha AM, Kuehn S, Hurst J, Herms F, Fehr M, Bartz-Schmidt KU, Dick HB, Joachim SC, Schnichels S. Diminished apoptosis in hypoxic porcine retina explant cultures through hypothermia. Sci Rep 2019; 9:4898. [PMID: 30894574 PMCID: PMC6427006 DOI: 10.1038/s41598-019-41113-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 02/13/2019] [Indexed: 12/22/2022] Open
Abstract
Simulation of hypoxic processes in vitro can be achieved through cobalt chloride (CoCl2), which induces strong neurodegeneration. Hypoxia plays an important role in the progression of several retinal diseases. Thus, we investigated whether hypoxia can be reduced by hypothermia. Porcine retinal explants were cultivated for four and eight days and hypoxia was mimicked by adding 300 µM CoCl2 from day one to day three. Hypothermia treatment (30 °C) was applied simultaneously. Retinal ganglion, bipolar and amacrine cells, as well as microglia were evaluated via immunohistological and western blot analysis. Furthermore, quantitative real-time PCR was performed to analyze cellular stress and apoptosis. In addition, the expression of specific marker for the previously described cell types were investigated. A reduction of ROS and stress markers HSP70, iNOS, HIF-1α was achieved via hypothermia. In accordance, an inhibition of apoptotic proteins (caspase 3, caspase 8) and the cell cycle arrest gene p21 was found in hypothermia treated retinae. Furthermore, neurons of the inner retina were protected by hypothermia. In this study, we demonstrate that hypothermia lowers hypoxic processes and cellular stress. Additionally, hypothermia inhibits apoptosis and protects neurons. Hence, this seems to be a promising treatment for retinal neurodegeneration.
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Affiliation(s)
- Ana M Maliha
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Sandra Kuehn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - José Hurst
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany
| | - Fenja Herms
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
- Clinic for Small Animals, University of Veterinary Medicine, Hannover, Germany
| | - Michael Fehr
- Clinic for Small Animals, University of Veterinary Medicine, Hannover, Germany
| | - Karl U Bartz-Schmidt
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Bochum, Germany.
| | - Sven Schnichels
- University Eye Hospital Tübingen, Centre for Ophthalmology Tübingen, Tübingen, Germany.
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12
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González Fleitas MF, Aranda ML, Dieguez HH, Devouassoux JD, Chianelli MS, Dorfman D, Rosenstein RE. Pre-ischemic enriched environment increases retinal resilience to acute ischemic damage in adult rats. Exp Eye Res 2019; 178:198-211. [DOI: 10.1016/j.exer.2018.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 10/02/2018] [Accepted: 10/12/2018] [Indexed: 01/10/2023]
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13
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Abstract
Neonatal encephalopathy is a major cause of neonatal mortality and morbidity. Therapeutic hypothermia is standard treatment for newborns at 35 weeks of gestation or more with intrapartum hypoxia-related neonatal encephalopathy. Term and late preterm infants with moderate-to-severe encephalopathy show improved survival and neurodevelopmental outcomes at 18 months of age after therapeutic hypothermia. Therapeutic hypothermia can increase survival without increasing major disability. Neonates with severe neonatal encephalopathy remain at risk of death or severe neurodevelopmental impairment. This guideline was prepared by the Turkish Neonatal Society to standardize the management of neonatal encephalopathy throughout the country.
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Affiliation(s)
- Mete Akisu
- Division of Neonatology, Department of Pediatrics, Ege University, Faculty of Medicine, İzmir, Turkey
| | - Abdullah Kumral
- Division of Neonatology, Department of Pediatrics, Dokuz Eylül University, Faculty of Medicine, İzmir, Turkey
| | - Fuat Emre Canpolat
- Clinic of Newborn, University of Health Sciences, Zekai Tahir Burak Women's Health Health Application and Research Center, Ankara, Turkey
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14
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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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15
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Hypothermia Prevents Retinal Damage Generated by Optic Nerve Trauma in the Rat. Sci Rep 2017; 7:6966. [PMID: 28761115 PMCID: PMC5537267 DOI: 10.1038/s41598-017-07294-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 06/26/2017] [Indexed: 11/11/2022] Open
Abstract
Ocular and periocular traumatisms may result in loss of vision. Hypothermia provides a beneficial intervention for brain and heart conditions and, here, we study whether hypothermia can prevent retinal damage caused by traumatic neuropathy. Intraorbital optic nerve crush (IONC) or sham manipulation was applied to male rats. Some animals were subjected to hypothermia (8 °C) for 3 h following surgery. Thirty days later, animals were subjected to electroretinography and behavioral tests. IONC treatment resulted in amplitude reduction of the b-wave and oscillatory potentials of the electroretinogram, whereas the hypothermic treatment significantly (p < 0.05) reversed this process. Using a descending method of limits in a two-choice visual task apparatus, we demonstrated that hypothermia significantly (p < 0.001) preserved visual acuity. Furthermore, IONC-treated rats had a lower (p < 0.0001) number of retinal ganglion cells and a higher (p < 0.0001) number of TUNEL-positive cells than sham-operated controls. These numbers were significantly (p < 0.0001) corrected by hypothermic treatment. There was a significant (p < 0.001) increase of RNA-binding motif protein 3 (RBM3) and of BCL2 (p < 0.01) mRNA expression in the eyes exposed to hypothermia. In conclusion, hypothermia constitutes an efficacious treatment for traumatic vision-impairing conditions, and the cold-shock protein pathway may be involved in mediating the beneficial effects shown in the retina.
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Non-linear actions of physiological agents: Finite disarrangements elicit fitness benefits. Redox Biol 2017; 13:235-243. [PMID: 28595161 PMCID: PMC5460745 DOI: 10.1016/j.redox.2017.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/11/2017] [Indexed: 12/16/2022] Open
Abstract
Finite disarrangements of important (vital) physiological agents and nutrients can induce plethora of beneficial effects, exceeding mere attenuation of the specific stress. Such response to disrupted homeostasis appears to be universally conserved among species. The underlying mechanism of improved fitness and longevity, when physiological agents act outside their normal range is similar to hormesis, a phenomenon whereby toxins elicit beneficial effects at low doses. Due to similarity with such non-linear response to toxins described with J-shaped curve, we have coined a new term “mirror J-shaped curves” for non-linear response to finite disarrangement of physiological agents. Examples from the clinical trials and basic research are provided, along with the unifying mechanisms that tie classical non-linear response to toxins with the non-linear response to physiological agents (glucose, oxygen, osmolarity, thermal energy, calcium, body mass, calorie intake and exercise). Reactive oxygen species and cytosolic calcium seem to be common triggers of signaling pathways that result in these beneficial effects. Awareness of such phenomena and exploring underlying mechanisms can help physicians in their everyday practice. It can also benefit researchers when designing studies and interpreting growing number of scientific data showing non-linear responses to physiological agents.
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Longo L, Sinigaglia-Fratta LX, Weber GR, Janz-Moreira A, Kretzmann NA, Grezzana-Filho TDJM, Possa-Marroni N, Corso CO, Schmidt-Cerski CT, Reverbel-da-Silveira T, Álvares-da-Silva MR, dos-Santos JL. Hypothermia is better than ischemic preconditioning for preventing early hepatic ischemia/reperfusion in rats. Ann Hepatol 2016; 15:110-20. [PMID: 26626646 DOI: 10.5604/16652681.1184285] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Topical hypothermia (TH) and ischemic preconditioning (IPC) are used to decrease I/R injury. The efficacy of isolated or combined use of TH and IPC in the liver regarding inflammation and cytoprotection in early ischemia/reperfusion (I/R) injury needs to be evaluated. MATERIAL AND METHODS Wistar rats underwent 70% liver ischemia for 90 min followed by 120 min of reperfusion. Livers of animals allocated in the sham, normothermic ischemia (NI), IPC, TH, and TH+IPC groups were collected for molecular analyses by ELISA and Western blot, aiming to compare proinflammatory, anti-inflammatory, and antioxidant profiles. RESULTS Compared with NI, TH presented decreased tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-12 concentrations and increased IL-10 levels. TH animals displayed lower inducible nitric oxide synthase (iNOS) and higher endothelial nitric oxide synthase (eNOS) expressions. NAD(P)H-quinone oxidoreductase-1(NQO1) expression was also lower with TH. Isolated IPC and NI were similar regarding all these markers. TH+IPC was associated with decreased IL-12 concentration and reduced iNOS and NQO1 expressions, similarly to isolated TH. Expression of Kelch-like ECH-associated protein (Keap)-1 was increased and expression of nuclear and cytosolic nuclear erythroid 2-related factor 2 (Nrf2) was decreased with TH+IPC vs. NI. CONCLUSION TH was the most effective method of protection against early I/R injury. Isolated IPC entailed triggering of second-line antioxidant defense enzymes. Combined TH+IPC seemed to confer no additional advantage over isolated TH in relation to the inflammatory process, but had the advantage of completely avoid second-line antioxidant defense enzymes.
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Affiliation(s)
- Larisse Longo
- Graduate Program in Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Leila Xavier Sinigaglia-Fratta
- Graduate Program in Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Giovana R Weber
- Graduate Program in Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Andrea Janz-Moreira
- Experimental Laboratory of Hepatology and Gastroenterology,Porto Alegre, Brazil
| | | | | | - Norma Possa-Marroni
- Experimental Laboratory of Hepatology and Gastroenterology,Porto Alegre, Brazil
| | | | | | | | - Mário R Álvares-da-Silva
- Graduate Program in Gastroenterology and Hepatology, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Jorge L dos-Santos
- Experimental Laboratory of Hepatology and Gastroenterology,Porto Alegre, Brazil
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Larrayoz IM, Rey-Funes M, Contartese DS, Rolón F, Sarotto A, Dorfman VB, Loidl CF, Martínez A. Cold Shock Proteins Are Expressed in the Retina Following Exposure to Low Temperatures. PLoS One 2016; 11:e0161458. [PMID: 27556928 PMCID: PMC4996528 DOI: 10.1371/journal.pone.0161458] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 08/05/2016] [Indexed: 12/05/2022] Open
Abstract
Hypothermia has been proposed as a therapeutic intervention for some retinal conditions, including ischemic insults. Cold exposure elevates expression of cold-shock proteins (CSP), including RNA-binding motif protein 3 (RBM3) and cold inducible RNA-binding protein (CIRP), but their presence in mammalian retina is so far unknown. Here we show the effects of hypothermia on the expression of these CSPs in retina-derived cell lines and in the retina of newborn and adult rats. Two cell lines of retinal origin, R28 and mRPE, were exposed to 32°C for different time periods and CSP expression was measured by qRT-PCR and Western blotting. Neonatal and adult Sprague-Dawley rats were exposed to a cold environment (8°C) and expression of CSPs in their retinas was studied by Western blotting, multiple inmunofluorescence, and confocal microscopy. RBM3 expression was upregulated by cold in both R28 and mRPE cells in a time-dependent fashion. On the other hand, CIRP was upregulated in R28 cells but not in mRPE. In vivo, expression of CSPs was negligible in the retina of newborn and adult rats kept at room temperature (24°C). Exposure to a cold environment elicited a strong expression of both proteins, especially in retinal pigment epithelium cells, photoreceptors, bipolar, amacrine and horizontal cells, Müller cells, and ganglion cells. In conclusion, CSP expression rapidly rises in the mammalian retina following exposure to hypothermia in a cell type-specific pattern. This observation may be at the basis of the molecular mechanism by which hypothermia exerts its therapeutic effects in the retina.
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Affiliation(s)
- Ignacio M. Larrayoz
- Angiogenesis Study Group, Center for Biomedical Research of La Rioja (CIBIR), 26006, Logroño, Spain
- * E-mail:
| | - Manuel Rey-Funes
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis” (IBCN), Facultad de Medicina, Universidad de Buenos Aires, CONICET, Paraguay 2155 (C1428ABG), Ciudad Autónoma de Buenos Aires, Argentina
| | - Daniela S. Contartese
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis” (IBCN), Facultad de Medicina, Universidad de Buenos Aires, CONICET, Paraguay 2155 (C1428ABG), Ciudad Autónoma de Buenos Aires, Argentina
| | - Federico Rolón
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis” (IBCN), Facultad de Medicina, Universidad de Buenos Aires, CONICET, Paraguay 2155 (C1428ABG), Ciudad Autónoma de Buenos Aires, Argentina
| | - Anibal Sarotto
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis” (IBCN), Facultad de Medicina, Universidad de Buenos Aires, CONICET, Paraguay 2155 (C1428ABG), Ciudad Autónoma de Buenos Aires, Argentina
| | - Veronica B. Dorfman
- Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Hidalgo 775 (C1405BCK), Ciudad Autónoma de Buenos Aires, Argentina
| | - Cesar F. Loidl
- Laboratorio de Neuropatología Experimental, Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis” (IBCN), Facultad de Medicina, Universidad de Buenos Aires, CONICET, Paraguay 2155 (C1428ABG), Ciudad Autónoma de Buenos Aires, Argentina
- Laboratorio de Neurociencia, Facultad de Ciencias Médicas, Universidad Católica de Cuyo. San Juan, Argentina
| | - Alfredo Martínez
- Angiogenesis Study Group, Center for Biomedical Research of La Rioja (CIBIR), 26006, Logroño, Spain
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Neuroprotective hypothermia - Why keep your head cool during ischemia and reperfusion. Biochim Biophys Acta Gen Subj 2016; 1860:2521-2528. [PMID: 27475000 DOI: 10.1016/j.bbagen.2016.07.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/28/2016] [Accepted: 07/25/2016] [Indexed: 12/20/2022]
Abstract
BACKGROUND Targeted temperature management (TTM) is the induced cooling of the entire body or specific organs to help prevent ischemia and reperfusion (I/R) injury, as may occur during major surgery, cardiac resuscitation, traumatic brain injury and stroke. Ischemia and reperfusion induce neuronal damage by mitochondrial dysfunction and oxidative injury, ER stress, neuronal excitotoxicity, and a neuroinflammatory response, which may lead to activation of apoptosis pathways. SCOPE OF REVIEW The aim of the current review is to discuss TTM targets that convey neuroprotection and to identify potential novel pharmacological intervention strategies for the prevention of cerebral ischemia and reperfusion injury. MAJOR CONCLUSIONS TTM precludes I/R injury by reducing glutamate release and oxidative stress and inhibiting release of pro-inflammatory factors and thereby counteracts mitochondrial induced apoptosis, neuronal excitotoxicity, and neuroinflammation. Moreover, TTM promotes regulation of the unfolded protein response and induces SUMOylation and the production of cold shock proteins. These advantageous effects of TTM seem to depend on the clinical setting, as well as type and extent of the injury. Therefore, future aims should be to refine hypothermia management in order to optimize TTM utilization and to search for pharmacological agents mimicking the cellular effects of TTM. GENERAL SIGNIFICANCE Bundling knowledge about TTM in the experimental, translational and clinical setting may result in better approaches for diminishing I/R damage. While application of TTM in the clinical setting has some disadvantages, targeting its putative protective pathways may be useful to prevent I/R injury and reduce neurological complications.
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Binda NS, Carayon CPP, Agostini RM, Pinheiro ACDN, Cordeiro MN, Silva MAR, Silva JF, Pereira EMR, da Silva Junior CA, de Castro Junior CJ, Guimarães ALS, Gomez MV. PhTx3-4, a Spider Toxin Calcium Channel Blocker, Reduces NMDA-Induced Injury of the Retina. Toxins (Basel) 2016; 8:toxins8030070. [PMID: 26978403 PMCID: PMC4810215 DOI: 10.3390/toxins8030070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 01/26/2016] [Accepted: 03/01/2016] [Indexed: 11/16/2022] Open
Abstract
The in vivo neuroprotective effect of PhTx3-4, a spider toxin N-P/Q calcium channel blocker, was studied in a rat model of NMDA-induced injury of the retina. NMDA (N-Methyl-d-Aspartate)-induced retinal injury in rats reduced the b-wave amplitude by 62% ± 3.6%, indicating the severity of the insult. PhTx3-4 treatment increased the amplitude of the b-wave, which was almost equivalent to the control retinas that were not submitted to injury. The PhTx3-4 functional protection of the retinas recorded on the ERG also was observed in the neuroprotection of retinal cells. NMDA-induced injury reduced live cells in the retina layers and the highest reduction, 84%, was in the ganglion cell layer. Notably, PhTx3-4 treatment caused a remarkable reduction of dead cells in the retina layers, and the highest neuroprotective effect was in the ganglion cells layer. NMDA-induced cytotoxicity of the retina increased the release of glutamate, reactive oxygen species (ROS) production and oxidative stress. PhTx3-4 treatment reduced glutamate release, ROS production and oxidative stress measured by malondialdehyde. Thus, we presented for the first time evidence of in vivo neuroprotection from NMDA-induced retinal injury by PhTx3-4 (-ctenitoxin-Pn3a), a spider toxin that blocks N-P/Q calcium channels.
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Affiliation(s)
- Nancy Scardua Binda
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Charles Porto Petruceli Carayon
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Rafael Mourão Agostini
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Ana Cristina do Nascimento Pinheiro
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Marta Nascimento Cordeiro
- Ezequiel Dias Foundation (FUNED), Laboratory of Biochemistry, Rua Conde Pereira Carneiro 80, Belo Horizonte, Minas Gerais 30510-010, Brazil.
| | - Marco Aurélio Romano Silva
- Faculty of Medicine, Minas Gerais Federal University, Neuroscience Laboratory, Av. Alfredo Balena 190, Belo Horizonte, Minas Gerais 30130-100, Brazil.
| | - Juliana Figueira Silva
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Elizete Maria Rita Pereira
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Claudio Antonio da Silva Junior
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Célio José de Castro Junior
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
| | - Andre Luiz Sena Guimarães
- Department of Dentistry, Montes Claros State University, University Hospital, Health Laboratory Research, Montes Claros, Montes Claros, Minas Gerais 39401-001, Brazil.
| | - Marcus Vinicius Gomez
- Institute of Education and Research Santa Casa Belo Horizonte-Laboratory of Toxins, Rua Domingos Vieira 590, Belo Horizonte, Minas Gerais 30150-240, Brazil.
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Schultheiss M, Schnichels S, Hermann T, Hurst J, Feldkaemper M, Arango-Gonzalez B, Ueffing M, Bartz-Schmidt KU, Zeck G, Spitzer MS. Hypothermia Protects and Prolongs the Tolerance Time of Retinal Ganglion Cells against Ischemia. PLoS One 2016; 11:e0148616. [PMID: 26848953 PMCID: PMC4744055 DOI: 10.1371/journal.pone.0148616] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 01/21/2016] [Indexed: 11/26/2022] Open
Abstract
Purpose Hypothermia has been shown to be neuroprotective in the therapy of ischemic stroke in the brain. To date no studies exist on the level of the inner retina and it is unclear if hypothermia would prolong the ischemic tolerance time of retinal ganglion cells, which are decisive in many ischemic retinopathies. Methods Bovine eyes were enucleated and stored either at 21°C or 37°C for 100 or 340 minutes, respectively. Afterwards the globes were dissected, the retina was prepared and either the spontaneous ganglion cell responses were measured or the retina was incubated as an organotypic culture for additional 24 hours. After incubation the retina was either processed for histology (H&E and DAPI staining) or real-time PCR (Thy-1 expression) was performed. Results Hypothermia prolonged ganglion cell survival up to 340 minutes under ischemic conditions. In contrast to eyes kept at 37°C the eyes stored at 21°C still showed spontaneous ganglion cell spiking (56.8% versus 0%), a 5.8 fold higher Thy-1 mRNA expression (not significant, but a trend) and a preserved retinal structure after 340 minutes of ischemia. Conclusion Hypothermia protects retinal ganglion cells against ischemia and prolongs their ischemic tolerance time.
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Affiliation(s)
| | - Sven Schnichels
- Centre for Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
- * E-mail:
| | - Thoralf Hermann
- Natural and Medical Sciences Institute at the University Tübingen, Reutlingen, Germany
| | - Jose Hurst
- Centre for Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
| | - Marita Feldkaemper
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Marius Ueffing
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Guenther Zeck
- Natural and Medical Sciences Institute at the University Tübingen, Reutlingen, Germany
| | - Martin S. Spitzer
- Centre for Ophthalmology, University Eye Hospital Tübingen, Tübingen, Germany
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Microglial Activation Promotes Cell Survival in Organotypic Cultures of Postnatal Mouse Retinal Explants. PLoS One 2015; 10:e0135238. [PMID: 26252475 PMCID: PMC4529135 DOI: 10.1371/journal.pone.0135238] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 07/20/2015] [Indexed: 02/03/2023] Open
Abstract
The role of microglia during neurodegeneration remains controversial. We investigated whether microglial cells have a neurotoxic or neuroprotective function in the retina. Retinal explants from 10-day-old mice were treated in vitro with minocycline to inhibit microglial activation, with LPS to increase microglial activation, or with liposomes loaded with clodronate (Lip-Clo) to deplete microglial cells. Flow cytometry was used to assess the viability of retinal cells in the explants and the TUNEL method to show the distribution of dead cells. The immunophenotypic and morphological features of microglia and their distribution were analyzed with flow cytometry and immunocytochemistry. Treatment of retinal explants with minocycline reduced microglial activation and simultaneously significantly decreased cell viability and increased the presence of TUNEL-labeled cell profiles. This treatment also prevented the migration of microglial cells towards the outer nuclear layer, where cell death was most abundant. The LPS treatment increased microglial activation but had no effect on cell viability or microglial distribution. Finally, partial microglial removal with Lip-Clo diminished the cell viability in the retinal explants, showing a similar effect to that of minocycline. Hence, cell viability is diminished in retinal explants cultured in vitro when microglial cells are removed or their activation is inhibited, indicating a neurotrophic role for microglia in this system.
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Aranda ML, Dorfman D, Sande PH, Rosenstein RE. Experimental optic neuritis induced by the microinjection of lipopolysaccharide into the optic nerve. Exp Neurol 2015; 266:30-41. [PMID: 25687552 DOI: 10.1016/j.expneurol.2015.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 12/26/2014] [Accepted: 01/29/2015] [Indexed: 10/24/2022]
Abstract
Optic neuritis (ON) is a condition involving primary inflammation, demyelination, and axonal injury in the optic nerve which leads to retinal ganglion cell (RGC) loss, and visual dysfunction. We investigated the ability of a single microinjection of bacterial lipopolysaccharide (LPS) directly into the optic nerve to induce functional and structural alterations compatible with ON. For this purpose, optic nerves from male Wistar rats remained intact or were injected with vehicle or LPS. The effect of LPS was evaluated at several time points post-injection in terms of: i) visual pathway and retinal function (visual evoked potentials (VEPs) and electroretinograms, (ERGs), respectively), ii) anterograde transport from the retina to its projection areas, iii) consensual pupil light reflex (PLR), iv) optic nerve histology, v) microglia/macrophage reactivity (by Iba-1- and ED1-immunostaining), vi) astrocyte reactivity (by glial fibrillary acid protein-immunostaining), vii) axon number (by toluidine blue staining), vii) demyelination (by myelin basic protein immunoreactivity and luxol fast blue staining), viii) optic nerve ultrastructure, and ix) RGC number (by Brn3a immunoreactivity). LPS induced a significant and persistent decrease in VEP amplitude and PLR, without changes in the ERG. In addition, LPS induced a deficit in anterograde transport, and an early inflammatory response consisting in an increased cellularity, and Iba-1 and ED1-immunoreactivity in the optic nerve, which were followed by changes in axonal density, astrocytosis, demyelination, and axon and RGC loss. These results suggest that the microinjection of LPS into the optic nerve may serve as a new experimental model of primary ON.
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Affiliation(s)
- Marcos L Aranda
- Laboratorio de Neuroquímica Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina/CEFyBO, Universidad de Buenos Aires/CONICET, Paraguay 2155, Buenos Aires, Argentina
| | - Damián Dorfman
- Laboratorio de Neuroquímica Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina/CEFyBO, Universidad de Buenos Aires/CONICET, Paraguay 2155, Buenos Aires, Argentina
| | - Pablo H Sande
- Laboratorio de Neuroquímica Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina/CEFyBO, Universidad de Buenos Aires/CONICET, Paraguay 2155, Buenos Aires, Argentina
| | - Ruth E Rosenstein
- Laboratorio de Neuroquímica Retiniana y Oftalmología Experimental, Departamento de Bioquímica Humana, Facultad de Medicina/CEFyBO, Universidad de Buenos Aires/CONICET, Paraguay 2155, Buenos Aires, Argentina.
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Effects of a conventional photocoagulator and a 3-ns pulse laser on preconditioning responses and retinal ganglion cell survival after optic nerve crush. Exp Eye Res 2014; 127:77-90. [DOI: 10.1016/j.exer.2014.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 07/07/2014] [Accepted: 07/10/2014] [Indexed: 11/22/2022]
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