1
|
Mohammad HMF, Eladl MA, Abdelmaogood AKK, Elshaer RE, Ghanam W, Elaskary A, Saleh MAK, Eltrawy AH, Ali SK, Moursi SMM, Bilasy SE, Zaitone SA, Alzlaiq WA, Atteya H. Protective Effect of Topiramate against Diabetic Retinopathy and Computational Approach Recognizing the Role of NLRP3/IL-1β/TNF-α Signaling. Biomedicines 2023; 11:3202. [PMID: 38137423 PMCID: PMC10741203 DOI: 10.3390/biomedicines11123202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/27/2023] [Accepted: 11/07/2023] [Indexed: 12/24/2023] Open
Abstract
The possible impact of topiramate against diabetic retinopathy (DREN) and its molecular mechanisms in relation to the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome has not been studied before. Thus, in the present study, we aimed to utilize a computational approach to investigate the possible protective effect of topiramate on experimental DREN and explore its impact on NLRP3/interlukin-1β signaling and brain-derived neurotrophic factor (BDNF) expression. Male albino mice were distributed to four experimental groups and assigned the following categorizations: (i) saline, (ii) diabetic, (iii) diabetic + topiramate 10 mg/kg and (iv) diabetic + topiramate 30 mg/kg. We observed shrinkage of total retinal thickness and elevation in retinal glutamate, malondialdehyde, NLRP3 and interlukin-1β but decreased glutathione (GSH) levels in the diabetic mice. Additionally, retinal ultra-structures in the diabetic group showed abnormalities and vacuolations in the pigmented epithelium, the photoreceptor segment, the outer nuclear layer, the inner nuclear layer and the ganglion cell layer (GCL). Mice treated with topiramate 10 or 30 mg/kg showed downregulation in retinal malondialdehyde, NLRP3 and interlukin-1β levels; improvements in the retinal pathologies; enhanced immunostaining for BDNF and improved ultra-structures in different retinal layers. Overall, the current results suggest topiramate as a neuroprotective agent for DREN, and future studies are warranted to further elucidate the mechanism of its protective action.
Collapse
Affiliation(s)
- Hala M. F. Mohammad
- Department of Clinical Pharmacology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
- Center of Excellence in Molecular and Cellular Medicine (CEMCM), Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Mohamed Ahmed Eladl
- Department of Basic Medical Sciences, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
| | - Asmaa K. K. Abdelmaogood
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Suez Canal University, Ismailia 41522, Egypt
| | - Rabie E. Elshaer
- Pathology Department, Faculty of Medicine (Boys), Al-Azhar University, Cairo 11884, Egypt
| | - Walaa Ghanam
- Department of Pathology, Faculty of Medicine, Suez University, Suez 43533, Egypt
| | - Abdelhakeem Elaskary
- Ophthalmology Department, Al-Azher Asyut Faculty of Medicine for Men, Asyut 71524, Egypt (M.A.K.S.)
| | - Mohamed A. K. Saleh
- Ophthalmology Department, Al-Azher Asyut Faculty of Medicine for Men, Asyut 71524, Egypt (M.A.K.S.)
| | - Amira H. Eltrawy
- Department of Anatomy and Embryology, Faculty of Medicine, Alexandria University, Alexandria 21526, Egypt
- Department of Anatomy, Faculty of Medicine, University of Tabuk, Tabuk 71451, Saudi Arabia
| | - Sahar K. Ali
- Department of Clinical Pharmacology, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Suzan M. M. Moursi
- Medical Physiology Department, Faculty of Medicine, Zagazig University, Zagazig 44519, Egypt
| | - Shymaa E. Bilasy
- College of Dental Medicine, California Northstate University, 9700 Taron Dr., Elk Grove, CA 95757, USA
- Department of Biochemistry, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Sawsan A. Zaitone
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk 71451, Saudi Arabia
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt
| | - Wafa Ali Alzlaiq
- Department of Clinical Pharmacy, College of Pharmacy, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Hayam Atteya
- Department of Pharmacy Practice and Clinical Pharmacy, Faculty of Pharmacy, Future University in Egypt, Cairo 11835, Egypt
- Department of Medical Pharmacology, Faculty of Medicine, Cairo University, Giza 12613, Egypt
| |
Collapse
|
2
|
Ahmadzadeh M, Esmaeilzadeh Z, Khezri MR, Jafari A, Ghasemnejad-Berenji M. The Promising Effect of Topiramate on Random-Pattern Skin Flap Survival in Rats. Aesthetic Plast Surg 2022; 46:2548-2555. [PMID: 35715535 DOI: 10.1007/s00266-022-02969-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/21/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Partial necrosis of skin flaps following plastic and reconstructive surgeries is one of the major problems in these medical interventions. This study was conducted to evaluate the beneficial effects of topiramate an anti-epileptic agent on ischemic random skin flaps. MATERIALS AND METHODS Twenty-four Wistar rats were provided and randomly divided into four experimental groups (control group and low-, intermediate- and high-dose treatment groups). A rat random-pattern skin flap model was performed in all groups, and animals in the low-, intermediate- and high-dose experimental groups were administered topiramate intraperitoneally at doses of 25, 50 and 100 mg/kg, respectively, 1 h before raising the flap and once daily for 7 consecutive days after the initial surgical procedure. Control rats received vehicle according to the same schedule. On postoperative day 7 the flap necrotic area was measured, and tissue samples were stained with hematoxylin and eosin for histological analysis. Furthermore, the oxidative stress in flap tissue was assessed by measuring the activity of superoxide dismutase (SOD), glutathione (GSH) level and the content of malondialdehyde (MDA). RESULTS Treating animals with 50 and 100 mg/kg topiramate significantly decreased the necrotic flap areas as compared to the control group. Histological studies demonstrated that in intermediate and high dose topiramate groups the inflammatory cell numbers were attenuated and microvessel development were markedly increased. Furthermore, the MDA contents were significantly reduced and GSH levels were significantly increased in these groups as compared to the control group. However, the SOD activity was increased significantly only in high-dose group as compared to the control group. CONCLUSIONS These findings indicated that topiramate in doses of 50 and 100 mg/kg increases random skin flap survival. NO LEVEL ASSIGNED This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
Collapse
Affiliation(s)
- Mehdi Ahmadzadeh
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
| | - Zeinab Esmaeilzadeh
- Department of Nutrition, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
- Department of Biochemistry, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | | | - Abbas Jafari
- Department of Toxicology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
- Cellular and Molecular Research Center, Research Institute on Cellular and Molecular Medicine, Urmia University of Medical Sciences, Urmia, Iran.
| | - Morteza Ghasemnejad-Berenji
- Experimental and Applied Pharmaceutical Research Center, Urmia University of Medical Sciences, Urmia, Iran.
- Department of Pharmacology and Toxicology, School of Pharmacy, Urmia University of Medical Sciences, Urmia, Iran.
| |
Collapse
|
3
|
Yang X, Wang Y, Wu C, Ling EA. Animal Venom Peptides as a Treasure Trove for New Therapeutics Against Neurodegenerative Disorders. Curr Med Chem 2019; 26:4749-4774. [PMID: 30378475 DOI: 10.2174/0929867325666181031122438] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/08/2018] [Accepted: 10/24/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and cerebral ischemic stroke, impose enormous socio-economic burdens on both patients and health-care systems. However, drugs targeting these diseases remain unsatisfactory, and hence there is an urgent need for the development of novel and potent drug candidates. METHODS Animal toxins exhibit rich diversity in both proteins and peptides, which play vital roles in biomedical drug development. As a molecular tool, animal toxin peptides have not only helped clarify many critical physiological processes but also led to the discovery of novel drugs and clinical therapeutics. RESULTS Recently, toxin peptides identified from venomous animals, e.g. exenatide, ziconotide, Hi1a, and PcTx1 from spider venom, have been shown to block specific ion channels, alleviate inflammation, decrease protein aggregates, regulate glutamate and neurotransmitter levels, and increase neuroprotective factors. CONCLUSION Thus, components of venom hold considerable capacity as drug candidates for the alleviation or reduction of neurodegeneration. This review highlights studies evaluating different animal toxins, especially peptides, as promising therapeutic tools for the treatment of different neurodegenerative diseases and disorders.
Collapse
Affiliation(s)
- Xinwang Yang
- Department of Anatomy and Histology & Embryology, Faculty of Basic Medical Science, Kunming Medical University, Kunming 650500, Yunnan, China
| | - Ying Wang
- Key Laboratory of Chemistry in Ethnic Medicine Resource, State Ethnic Affairs Commission & Ministry of Education, School of Ethnomedicine and Ethnopharmacy, Yunnan Minzu University, Kunming 650500, Yunnan, China
| | - Chunyun Wu
- Department of Anatomy and Histology & Embryology, Faculty of Basic Medical Science, Kunming Medical University, Kunming 650500, Yunnan, China
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| |
Collapse
|
4
|
Vestergaard N, Cehofski LJ, Honoré B, Aasbjerg K, Vorum H. Animal Models Used to Simulate Retinal Artery Occlusion: A Comprehensive Review. Transl Vis Sci Technol 2019; 8:23. [PMID: 31440422 PMCID: PMC6701503 DOI: 10.1167/tvst.8.4.23] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 06/10/2019] [Indexed: 12/18/2022] Open
Abstract
Purpose To present an overview of animal models of retinal artery occlusion (RAO). Methods Through a systematic literature search in PubMed and Embase, papers describing methods of inducing RAO in animal models were included. The identified methodologic approaches were presented in a narrative synthesis and compared with RAO in humans. Results In total, 83 papers reporting on 88 experiments were included. Six different species were used with rodents and monkeys being the most common, and a minority were performed using cats, dogs, rabbits, or pigs. The anatomy of pigs and monkeys resemble that of humans most closely. The two most frequently used methods were laser-induced occlusion or ligation of the arteries. Other methods included raised intraocular pressure, arterial clamping, administration of vasoconstricting agents, the use of an occluder, embolization, and endovascular approaches to induce occlusion. In general, occlusions lasted for only 30 to 90 minutes, often followed by reperfusion. Conclusions Although a broad range of methods have previously been used, they all have limitations. Preferably, the methods should imitate the human disease as closely as possible and avoid damaging other structures. Therefore, monkeys followed by pigs are to be preferred and ligation or clamping may be a suitable model in larger animals as there is a potential to isolate and occlude the retinal artery only. Being less invasive, laser-induced occlusion is another suitable approach. Translational Relevance This review aims at assisting researchers in deciding on the most ideal experimental setting, and thereby increase the translational value to human disease.
Collapse
Affiliation(s)
- Nanna Vestergaard
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark
| | - Lasse Jørgensen Cehofski
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark.,Department of Ophthalmology, Vejle Hospital - part of Lillebaelt Hospital, Vejle, Denmark.,Department of Clinical Research, University of Southern Denmark, Odense, Denmark
| | - Bent Honoré
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.,Department of Clinical Medicine, Aalborg University Hospital, Aalborg, Denmark
| | - Kristian Aasbjerg
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark.,Department of Epidemiology, Aalborg University Hospital, Aalborg, Denmark
| | - Henrik Vorum
- Department of Ophthalmology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University Hospital, Aalborg, Denmark
| |
Collapse
|
5
|
Activation of 5-HT1A Receptors Promotes Retinal Ganglion Cell Function by Inhibiting the cAMP-PKA Pathway to Modulate Presynaptic GABA Release in Chronic Glaucoma. J Neurosci 2018; 39:1484-1504. [PMID: 30541912 DOI: 10.1523/jneurosci.1685-18.2018] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 12/12/2022] Open
Abstract
Serotonin (5-hydroxytryptamine, 5-HT) receptor agonists are neuroprotective in CNS injury models. However, the neuroprotective functional implications and synaptic mechanism of 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), a serotonin receptor (5-HT1A) agonist, in an adult male Wistar rat model of chronic glaucoma model remain unknown. We found that ocular hypertension decreased 5-HT1A receptor expression in rat retinas because the number of retinal ganglion cells (RGCs) was significantly reduced in rats with induced ocular hypertension relative to that in control retinas and 8-OH-DPAT enhanced the RGC viability. The protective effects of 8-OH-DPAT were blocked by intravitreal administration of the selective 5-HT1A antagonist WAY-100635 or the selective GABAA receptor antagonist SR95531. Using patch-clamp techniques, spontaneous and miniature GABAergic IPSCs (sIPSCs and mIPSCs, respectively) of RGCs in rat retinal slices were recorded. 8-OH-DPAT significantly increased the frequency and amplitude of GABAergic sIPSCs and mIPSCs in ON- and OFF-type RGCs. Among the signaling cascades mediated by the 5-HT1A receptor, the role of cAMP-protein kinase A (PKA) signaling was investigated. The 8-OH-DPAT-induced changes at the synaptic level were enhanced by PKA inhibition by H-89 and blocked by PKA activation with bucladesine. Furthermore, the density of phosphorylated PKA (p-PKA)/PKA was significantly increased in glaucomatous retinas and 8-OH-DPAT significantly decreased p-PKA/PKA expression, which led to the inhibition of PKA phosphorylation upon relieving neurotransmitter GABA release. These results showed that the activation of 5-HT1A receptors in retinas facilitated presynaptic GABA release functions by suppressing cAMP-PKA signaling and decreasing PKA phosphorylation, which could lead to the de-excitation of RGC circuits and suppress excitotoxic processes in glaucoma.SIGNIFICANCE STATEMENT We found that serotonin (5-HT) receptors in the retina (5-HT1A receptors) were downregulated after intraocular pressure elevation. Patch-clamp recordings demonstrated differences in the frequencies of miniature GABAergic IPSCs (mIPSCs) in ON- and OFF-type retinal ganglion cells (RGCs) and RGCs in normal and glaucomatous retinal slices. Therefore, phosphorylated protein kinase A (PKA) inhibition upon release of the neurotransmitter GABA was eliminated by 8-hydroxy-2- (di-n-propylamino) tetralin (8-OH-DPAT), which led to increased levels of GABAergic mIPSCs in ON- and OFF-type RGCs, thus enhancing RGC viability and function. These protective effects were blocked by the GABAA receptor antagonist SR95531 or the 5-HT1A antagonist WAY-100635. This study identified a novel mechanism by which activation of 5-HT1A receptors protects damaged RGCs via the cAMP-PKA signaling pathway that modulates GABAergic presynaptic activity.
Collapse
|
6
|
Schur RM, Gao S, Yu G, Chen Y, Maeda A, Palczewski K, Lu ZR. New GABA modulators protect photoreceptor cells from light-induced degeneration in mouse models. FASEB J 2018; 32:3289-3300. [PMID: 29401616 DOI: 10.1096/fj.201701250r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
No clinically approved therapies are currently available that prevent the onset of photoreceptor death in retinal degeneration. Signaling between retinal neurons is regulated by the release and uptake of neurotransmitters, wherein GABA is the main inhibitory neurotransmitter. In this work, novel 3-chloropropiophenone derivatives and the clinical anticonvulsants tiagabine and vigabatrin were tested to modulate GABA signaling and protect against light-induced retinal degeneration. Abca4-/-Rdh8-/- mice, an accelerated model of retinal degeneration, were exposed to intense light after prophylactic injections of one of these compounds. Imaging and functional assessments of the retina indicated that these compounds successfully protected photoreceptor cells from degeneration to maintain a full-visual-field response. Furthermore, these compounds demonstrated a strong safety profile in wild-type mice and did not compromise visual function or damage the retina, despite repeated administration. These results indicate that modulating inhibitory GABA signaling can offer prophylactic protection against light-induced retinal degeneration.-Schur, R. M., Gao, S., Yu, G., Chen, Y., Maeda, A., Palczewski, K., Lu, Z.-R. New GABA modulators protect photoreceptor cells from light-induced degeneration in mouse models.
Collapse
Affiliation(s)
- Rebecca M Schur
- Case Center for Biomolecular Engineering, Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Songqi Gao
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Guanping Yu
- Case Center for Biomolecular Engineering, Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yu Chen
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Akiko Maeda
- Department of Ophthalmology and Visual Sciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Zheng-Rong Lu
- Case Center for Biomolecular Engineering, Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| |
Collapse
|
7
|
Ford L, Goldberg JL, Selan F, Greenberg HE, Shi Y. Comprehensive review of visual defects reported with topiramate. Clin Ophthalmol 2017; 11:983-992. [PMID: 28579749 PMCID: PMC5449165 DOI: 10.2147/opth.s125768] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Objective The objective of this study was to analyze clinical patterns of visual field defects (VFDs) reported with topiramate treatment and assess possible mechanism of action (MOA) for antiepileptic drug (AED) associated VFDs. Methods A comprehensive topiramate database review included preclinical data, sponsor’s clinical trials database, postmarketing spontaneous reports, and medical literature. All treatment-emergent adverse events (TEAEs) suggestive of retinal dysfunction/damage were summarized. Relative risk (RR) was computed from topiramate double-blind, placebo-controlled trials (DBPCTs) data. Results Preclinical studies and medical literature review suggested that despite sharing gamma-aminobutyric acid (GABA)-ergic MOA with other AEDs, topiramate treatment was not associated with VFDs. TEAEs suggestive of retinal dysfunction/damage were observed in 0.3%–0.7% of adults and pediatric patients with topiramate (N=4,679) versus ≤0.1% with placebo (N=1,834) in DBPCTs for approved indications (epilepsy and migraine prophylaxis); open-label trials (OLTs) and DBPCTs for investigational indications had similar incidence. Overall, 88% TEAEs were mild or moderate in severity. Serious TEAEs were very rare (DBPCTs: 0%; OLTs: ≤0.1%), and most were not treatment limiting, and resolved. The most common visual TEAEs (approved indications) were VFD, scotoma, and optic atrophy. The incidence of TEAEs in DBPCTs (approved and investigational indications) was higher in topiramate-treated (N=9,169) versus placebo-treated patients (N=5,023; 0.36% vs 0.24%), but the RR versus placebo-treated patients was not significant (RR: 1.51 [95% confidence interval: 0.78, 2.91]). Conclusion VFDs do not appear to be a class effect for AEDs with GABA-ergic MOA. The RR for VFDs is not significantly different between topiramate and placebo treatment.
Collapse
Affiliation(s)
- Lisa Ford
- Janssen Research & Development, LLC, Titusville, NJ
| | | | - Fred Selan
- Janssen Research & Development, LLC, Titusville, NJ
| | | | - Yingqi Shi
- Janssen Research & Development, LLC, Titusville, NJ
| |
Collapse
|
8
|
Shibagaki K, Okamoto K, Katsuta O, Nakamura M. Beneficial protective effect of pramipexole on light-induced retinal damage in mice. Exp Eye Res 2015. [PMID: 26213307 DOI: 10.1016/j.exer.2015.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We investigated the effects of pramipexole, a potent dopamine receptor D2/D3 agonist, on light-induced retinal damage in mice, H2O2-induced retinal pigment epithelium ARPE-19 cell injury in humans, and hydroxyl radical scavenging activity in a cell-free system. Pramipexole (0.1 and 1 mg/kg body weight) was orally administered to mice 1 h before light exposure (5000 lux, 2 h). Electrophysiological and morphologic studies were performed to evaluate the effects of the pramipexole on light-induced retinal damage in mice. Pramipexole significantly prevented the reduction of the a- and b-wave electroretinogram (ERG) amplitudes caused by light exposure in a dose-dependent manner. In parallel, damage to the inner and outer segments (IS/OS) of the photoreceptors, loss of photoreceptor nuclei, and the number of Tdt-mediated dUTP nick-end labeling (TUNEL)-positive cells in the outer nuclear layer (ONL) caused by light exposure were notably ameliorated by pramipexole. Additionally, pramipexole suppressed H2O2-induced ARPE-19 cell death in vitro in a concentration-dependent manner. The effect of pramipexole was significant at concentrations of 10(-6) M or higher. Pramipexole also significantly prevented H2O2-induced activation of caspases-3/7 and the intracellular accumulation of reactive oxygen species (ROS) in a concentration-dependent manner ranging from 10(-5) to 10(-3) M. Furthermore, pramipexole increased the scavenging activity toward a hydroxyl radical generated from H2O2 in a Fenton reaction. Our results suggest that pramipexole protects against light-induced retinal damage as an antioxidant and that it may be a novel and effective therapy for retinal degenerative disorders, such as dry age-related macular degeneration.
Collapse
Affiliation(s)
- Keiichi Shibagaki
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan; Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma-shi, Nara 630-0192, Japan.
| | - Kazuyoshi Okamoto
- Corporate Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
| | - Osamu Katsuta
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
| | - Masatsugu Nakamura
- Research and Development Division, Santen Pharmaceutical Co., Ltd., 4-20, Ofuka-cho, Kita-ku, Osaka 530-8552, Japan
| |
Collapse
|
9
|
Experimentally Induced Mammalian Models of Glaucoma. BIOMED RESEARCH INTERNATIONAL 2015; 2015:281214. [PMID: 26064891 PMCID: PMC4433635 DOI: 10.1155/2015/281214] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/01/2014] [Indexed: 11/17/2022]
Abstract
A wide variety of animal models have been used to study glaucoma. Although these models provide valuable information about the disease, there is still no ideal model for studying glaucoma due to its complex pathogenesis. Animal models for glaucoma are pivotal for clarifying glaucoma etiology and for developing novel therapeutic strategies to halt disease progression. In this review paper, we summarize some of the major findings obtained in various glaucoma models and examine the strengths and limitations of these models.
Collapse
|
10
|
Liu Z, Huang YY, Wang YX, Wang HG, Deng F, Heng B, Xie LH, Liu YQ. Prevention of cell death by the zinc ion chelating agent TPEN in cultured PC12 cells exposed to Oxygen-Glucose Deprivation (OGD). J Trace Elem Med Biol 2015; 31:45-52. [PMID: 26004891 DOI: 10.1016/j.jtemb.2015.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 03/07/2015] [Accepted: 03/20/2015] [Indexed: 11/28/2022]
Abstract
To elucidate the role of Zn(2+)-associated glutamate signaling pathway and voltage-dependent outward potassium ion currents in neuronal death induced by hypoxia-ischemia, PC12 cells were exposed to Oxygen-Glucose Deprivation (OGD) solution mimicking the hypoxic-ischemic condition in neuron, and the effect of N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a specific Zn(2+) chelating agent on OGD-induced neuronal death was assessed in the present study. The cell survival rate, apoptosis status, potassium channel currents, intracellular free glutamate concentration and GluR2 expression in PC12 cells exposed to OGD in the absence or presence of TPEN for different time were investigated. The results showed that OGD exposure increased apoptosis, reduced the cell viability (P < 0.01 at 3h, 6h and 24h, respectively compared to control), changed the voltage-dependent outward potassium ion current (increase at 1h, but decrease at 3h) and decreased the concentration of intracellular glutamate (P < 0.05 at 3h and 6h, P < 0.01 at 24h respectively compared to control) and GluR2 expression (P < 0.05 at 3h, 6h and 24h, respectively compared to control) in PC12 cells. TPEN partially reversed the influence resulted from OGD. These results suggest that OGD-induced cell apoptosis and/or death is mediated by the alteration in glutamate signaling pathway and the voltage-dependent outward potassium ion currents, while TPEN effectively prevent cell apoptosis and/or death under hypoxic-ischemic condition.
Collapse
Affiliation(s)
- Zhao Liu
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Yue-yang Huang
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Yu-xiang Wang
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Hong-gang Wang
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Fei Deng
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Bin Heng
- College of Life Sciences, Nankai University, Tianjin 300071, PR China
| | - Lai-hua Xie
- Department of Cell Biology and Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, USA
| | - Yan-qiang Liu
- College of Life Sciences, Nankai University, Tianjin 300071, PR China.
| |
Collapse
|
11
|
Sánchez-Villarejo MV, López-Pedrajas R, Sánchez-Vallejo V, Genovés JM, Muriach M, Barcia JM, Romero FJ, Miranda M. Chronic cocaine effects in retinal metabolism and electrophysiology: treatment with topiramate. Curr Eye Res 2013; 39:493-503. [PMID: 24215266 DOI: 10.3109/02713683.2013.850097] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Cocaine abuse is a major public health problem with multiple-related complications. Indeed, cocaine can affect almost every organ of the human body, but little is known about its effects on the visual system. The main purpose of this work was to study if topiramate was able to reverse changes in retinal metabolism and retinal function induced by chronic cocaine exposure in adult rats. MATERIALS AND METHODS Sixteen Wistar rats were treated with a daily oral dose of cocaine during 36 days. Sixteen rats receiving NaCl 0.9% served as controls. Eight control and eight cocaine animals were administered topiramate from day 18 to day 36 of the experiment. Malondialdehyde (MDA), glutathione (GSH) and glutamate content, as well as glutathione peroxidase (GPx) activity in retina tissue homogenates were determined. Retinal function was assessed by electroretinogram (ERG). RESULTS Glutamate concentration was increased in the retinas of cocaine-treated rats. No changes in oxidative stress parameters were observed in the retinas of cocaine-treated rats when compared with the control ones. Cocaine induced a decrease in the a-wave and b-wave ERG amplitude. The administration of topiramate reversed cocaine-induced increase in glutamate concentration and had little effect on a-wave and b-wave ERG amplitude. Topiramate, a drug used during the last decade for the treatment of epileptic seizures, is able to reverse the cocaine-induced alterations observed in retinal glutamate concentration. CONCLUSIONS We can conclude that retinal glutamate metabolism and function may be affected by exposure to cocaine. We confirm that topiramate, a treatment recently proposed for cocaine dependence, is also able to recover partially cocaine-induced changes in the retina.
Collapse
Affiliation(s)
- Maria V Sánchez-Villarejo
- Departamento Ciencias Biomédicas, Instituto de Ciencias Biomédicas, Universidad CEU Cardenal Herrera , Moncada , Spain
| | | | | | | | | | | | | | | |
Collapse
|
12
|
Effects of Topiramate on afferent visual pathways: controversies and uncertainties. Neurol Sci 2013; 34:603-4. [DOI: 10.1007/s10072-012-1109-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 04/24/2012] [Indexed: 10/28/2022]
|
13
|
Sivakumar V, Foulds WS, Luu CD, Ling EA, Kaur C. Hypoxia-induced retinal ganglion cell damage through activation of AMPA receptors and the neuroprotective effects of DNQX. Exp Eye Res 2013; 109:83-97. [PMID: 23375774 DOI: 10.1016/j.exer.2013.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 01/04/2013] [Accepted: 01/06/2013] [Indexed: 11/19/2022]
Abstract
Hypoxia-induced glutamate accumulation in neural tissues results in damage to neurons through excitotoxic mechanisms via activation of glutamate receptors (GluRs). Here we examine whether hypoxia in the developing retina would cause activation of the ionotropic α-amino-3-hydroxy-5-methylisoxazole-4-propioate (AMPA) GluRs and increase in Ca(2+) influx into retinal ganglion cells (RGCs) that might ultimately lead to their death. Neonatal Wistar rats were subjected to hypoxia for 2h and then sacrificed at various time points after the exposure together with normal age matched control rats. Primary cultures of RGCs were also prepared and subjected to hypoxia. Expression of AMPA glutamate receptor (GluR) 1-4 was examined in the retina. Additionally, expression of GluRs, intracellular Ca(2+) influx, reactive oxygen species (ROS) generation and cell death were investigated in cultured RGCs. GluR1-4 mRNA and protein expression showed a significant increase (P < 0.01) over control values after the hypoxic exposure both in vivo and in vitro. Cells expressing GluR1-4 in the retina were identified as RGCs by double immunofluorescence labeling with Thy1.1. Increased intracellular Ca(2+) in cultured RGCs following hypoxic exposure was reduced (P < 0.01) by 10 μM AMPA antagonist 6, 7-dinitroquinoxaline-2,3-dione (DNQX). Our results suggest that following a hypoxic insult, an increased amount of glutamate accumulates in the neonatal retina. This would then activate AMPA receptors which may damage RGCs through increased Ca(2+) accumulation and ROS generation. The involvement of AMPA receptors in damaging the RGCs is evidenced by suppression of intracellular Ca(2+) influx by DNQX which also decreased ROS generation and cell death by 50%.
Collapse
Affiliation(s)
- V Sivakumar
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, Singapore 117597, Singapore
| | | | | | | | | |
Collapse
|
14
|
Ishikawa M. Abnormalities in glutamate metabolism and excitotoxicity in the retinal diseases. SCIENTIFICA 2013; 2013:528940. [PMID: 24386591 PMCID: PMC3872404 DOI: 10.1155/2013/528940] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Accepted: 11/17/2013] [Indexed: 05/14/2023]
Abstract
In the physiological condition, glutamate acts as an excitatory neurotransmitter in the retina. However, excessive glutamate can be toxic to retinal neurons by overstimulation of the glutamate receptors. Glutamate excess is primarily attributed to perturbation in the homeostasis of the glutamate metabolism. Major pathway of glutamate metabolism consists of glutamate uptake by glutamate transporters followed by enzymatic conversion of glutamate to nontoxic glutamine by glutamine synthetase. Glutamate metabolism requires energy supply, and the energy loss inhibits the functions of both glutamate transporters and glutamine synthetase. In this review, we describe the present knowledge concerning the retinal glutamate metabolism under the physiological and pathological conditions.
Collapse
Affiliation(s)
- Makoto Ishikawa
- Department of Ophthalmology, Akita Graduate University Faculty of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan
- *Makoto Ishikawa:
| |
Collapse
|
15
|
Fleischman A, Parvari U, Oron Y, Geyer O. Monitoring the effect of mild ischemia with a built-in light-emitting diode contact lens electrode and a low-cost custom-made apparatus. Physiol Meas 2012; 33:1053-2. [PMID: 22561091 DOI: 10.1088/0967-3334/33/6/1053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Electroretinography (ERG) is widely used in clinical work and research to assess the retinal function. We evaluated an easy to build ERG setup adapted for small animals comprising two contact lens electrodes with a built-in light-emitting diode and a custom-made amplification system. The system's sensitivity was tested by monitoring ERG in albino rat eyes subjected to mild ischemia. Flash ERG was recorded by two contact lens electrodes positioned on the rat's corneas and used alternately as test or reference. The a- and b-wave amplitudes, a-wave latency, b-wave implicit time and oscillatory potentials (OPs) were analyzed. Ischemia was achieved by elevating the intraocular pressure in the eye's anterior chamber. ERG was recorded on post-ischemia (PI) days -1, 1, 3 and 7. Morphological changes were analyzed on hematoxylin/eosin stained 5 µm sections of control 7d PI retinas. In control eyes, ERG exhibited a pattern similar to a standard recording. Retinas subjected to mild ischemia preserved ordered layered morphology, exhibiting approximately 30% loss of ganglion cells and no changes in gross morphology. By day 3 PI, ischemia caused an increase in the a-wave amplitude (from 34.9 ± 2.7 to 45.4 ± 4.3 µV), a decrease in the b-wave amplitude (from 248 ± 13 to 162 ± 8 µV), an increase in a-wave latency (from 11.1 ± 0.3 to 17.3 ± 1.4 ms) and b-wave implicit time (from 81.0 ± 1.6 to 90.0 ± 2.5 ms), and attenuation of OPs. The described setup proved sensitive and reliable for evaluating subtle changes in the retinal function in small animals.
Collapse
Affiliation(s)
- A Fleischman
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
| | | | | | | |
Collapse
|
16
|
Abtahi MA, Abtahi SH, Fazel F, Roomizadeh P, Etemadifar M, Jenab K, Akbari M. Topiramate and the vision: a systematic review. Clin Ophthalmol 2012; 6:117-31. [PMID: 22275816 PMCID: PMC3261698 DOI: 10.2147/opth.s27695] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Topiramate (TPM) is a sulfa-derivative monosaccharide that is used mainly for treating epilepsy and preventing migraine. Within the gamut of side effects attributable to this drug, ophthalmologic manifestations are of crucial importance. In this study, for the first time, the aim was to provide a systematic literature review regarding this issue. METHODS For the time period 1996-2011, a PubMed search was made for the studies concerning the adverse/beneficial effects of TPM on vision. Overall, 404 citations out of a total of 2756 TPM-related studies were examined for relevance. RESULTS A total of 74 relevant studies were reviewed, 65 of which comprise small observational studies describing the ophthalmic side effects of TPM in 84 patients. Of these patients, 66 were affected by ciliochoroidal effusion syndrome as the cardinal ocular side effect of TPM (17 cases of myopic shift and 49 cases of angle closure glaucoma). A comprehensive statistical analysis is provided on these 66 subjects. Other rare side effects of TPM on the vision were also reviewed, including massive choroidal effusion, ocular inflammatory reactions, visual field defects, probable effects on retina, cornea, and sclera, and neuroophthalmologic complications. In addition, a framework is provided to classify these results. DISCUSSION Due to the expanding spectrum of indications for the administration of TPM, neurologists and psychiatrists should be aware of its diverse ocular side effects. In conclusion, ocular complications following this drug should be taken seriously and be subjected to ophthalmic counseling.
Collapse
Affiliation(s)
- Mohammad-Ali Abtahi
- Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
- Ophthalmology Ward, Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Eye Research Center (IERC), Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Seyed-Hossein Abtahi
- Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Eye Research Center (IERC), Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Medical Students Research Center (IMSRC), Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farhad Fazel
- Ophthalmology Ward, Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Eye Research Center (IERC), Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Peyman Roomizadeh
- Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Medical Students Research Center (IMSRC), Isfahan University of Medical Sciences, Isfahan, Iran
| | - Masoud Etemadifar
- Department of Neurology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Keivan Jenab
- Ophthalmology Ward, Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
- Isfahan Eye Research Center (IERC), Feiz Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mojtaba Akbari
- Medical School, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
17
|
Mikati MA, Daderian R, Zeinieh M, Leonard AS, Azzam D, Kurdi R. Potential neuroprotective effects of continuous topiramate therapy in the developing brain. Epilepsy Behav 2011; 20:597-601. [PMID: 21450530 DOI: 10.1016/j.yebeh.2010.12.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/18/2010] [Accepted: 12/07/2010] [Indexed: 01/27/2023]
Abstract
Because antiepileptic drug therapy is usually given chronically with resulting concerns about long-term neurotoxicity, and because short-term topiramate (TPM) therapy has been reported to be neuroprotective against the effects of acute hypoxia, we investigated the long-term effects of continuous TPM therapy during early stages of development. Four groups of rat pups were studied: two sham manipulated normoxia groups and two acute hypoxia groups (at postnatal day [P] 10 down to 4% O(2)), each injected intraperitoneally daily with either vehicle or TPM (30 mg/kg) from P0 to P21. TPM therapy prevented hypoxia-induced long-term (P81) memory impairment (Morris water maze) as well as aggressivity (handling test). The hypoxia group receiving TPM also showed a trend toward reduced CA1 hippocampal cell loss. The aforementioned TPM therapy had no long-term deleterious effects on memory, hyperactivity, or CA1 cell counts in the TPM normoxia group as compared with normal controls.
Collapse
Affiliation(s)
- Mohamad A Mikati
- Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
| | | | | | | | | | | |
Collapse
|
18
|
Baltmr A, Duggan J, Nizari S, Salt TE, Cordeiro MF. Neuroprotection in glaucoma - Is there a future role? Exp Eye Res 2010; 91:554-66. [PMID: 20800593 DOI: 10.1016/j.exer.2010.08.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 07/26/2010] [Accepted: 08/06/2010] [Indexed: 02/06/2023]
Abstract
In glaucoma, the major cause of global irreversible blindness, there is an urgent need for treatment modalities that directly target the RGCs. The discovery of an alternative therapeutic approach, independent of IOP reduction, is highly sought after, due to the indirect nature and limited effectiveness of IOP lowering therapy in preventing RGC loss. Several mechanisms have been implicated in initiating the apoptotic cascade in glaucomatous retinopathy and numerous drugs have been shown to be neuroprotective in animal models of glaucoma. These mechanisms and their potential treatment include excitotoxicity, protein misfolding, mitochondrial dysfunction, oxidative stress, inflammation and neurotrophin deprivation. All of these mechanisms ultimately lead to programmed cell death with loss of RGCs. In this article we summarize the mechanisms involved in glaucomatous disease, highlight the rationale for neuroprotection in glaucoma management and review current potential neuroprotective strategies targeting RGCs from the laboratory to the clinic.
Collapse
Affiliation(s)
- Abeir Baltmr
- Glaucoma and Retinal Neurodegeneration Research Group, Visual Neurosciences Department, University College London Institute of Ophthalmology, Bath Street, London EC1V 9EL, United Kingdom
| | | | | | | | | |
Collapse
|
19
|
Saggu S, Chotaliya H, Cai Z, Blumbergs P, Casson R. The spatiotemporal pattern of somal and axonal pathology after perikaryal excitotoxic injury to retinal ganglion cells: A histological and morphometric study. Exp Neurol 2008; 211:52-8. [DOI: 10.1016/j.expneurol.2007.12.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 12/12/2007] [Accepted: 12/18/2007] [Indexed: 11/26/2022]
|
20
|
Ruscher K, Rzeczinski S, Thein E, Freyer D, Victorov IV, Lam TT, Dirnagl U. Neuroprotective effects of the β-carboline abecarnil studied in cultured cortical neurons and organotypic retinal cultures. Neuropharmacology 2007; 52:1488-95. [PMID: 17449066 DOI: 10.1016/j.neuropharm.2007.02.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 02/11/2007] [Accepted: 02/13/2007] [Indexed: 12/28/2022]
Abstract
Presently there is no neuroprotective pharmacological treatment of proven clinical safety and efficacy available. The purpose of this study was to investigate whether the beta-carboline, abecarnil (Abe), which has already passed clinical phase III trials in patients with anxiety disorders, is neuroprotective in in vitro models of cerebral ischemia or excitotoxicity. Abe (100 nM) protected cultured cortical neurons when applied 20 min before or 20 min after combined oxygen glucose deprivation (OGD). Furthermore, cultured cortical neurons were protected from NMDA excitotoxicity when Abe (100 nM) was administered 20 min before or concurrent with 100 microM NMDA. In contrast, in adult rat organotypic retinal cultures, Abe failed to protect retinal ganglion cells (RGCs) against glutamate (Glu) excitotoxicity. Thus, although our data demonstrate that Abe is a potential neuroprotectant in cultured neurons, the lack of effect in an organotypical model of Glu toxicity indicates that further study is required before Abe might be considered for human neuroprotection trials.
Collapse
Affiliation(s)
- Karsten Ruscher
- Department of Experimental Neurology, Campus Charité Mitte, Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
21
|
Choi JW, Kim WK. Is topiramate a potential therapeutic agent for cerebral hypoxic/ischemic injury? Exp Neurol 2007; 203:5-7. [PMID: 17070522 DOI: 10.1016/j.expneurol.2006.09.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2006] [Accepted: 09/26/2006] [Indexed: 11/26/2022]
Affiliation(s)
- Ji Woong Choi
- Division of NanoSciences, Ewha Woman's University, 11-1, Daehyun-dong, Seodaemun-gu, Seoul 120-750, Republic of Korea
| | | |
Collapse
|
22
|
Sasaoka M, Taniguchi T, Shimazawa M, Ishida N, Shimazaki A, Hara H. Intravitreal injection of endothelin-1 caused optic nerve damage following to ocular hypoperfusion in rabbits. Exp Eye Res 2006; 83:629-37. [PMID: 16677631 DOI: 10.1016/j.exer.2006.03.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 03/02/2006] [Accepted: 03/07/2006] [Indexed: 10/24/2022]
Abstract
The purpose of this study was to investigate the time course of the ocular hypoperfusion, retinal damage, and optic nerve damage induced by intravitreal injection of endothelin-1 (ET-1) in rabbits. ET-1, at 5 pmol (20 microL, twice a week for 2 or 4 weeks), was injected from the pars plana into the posterior vitreous of the right eye. Optic nerve head (ONH) blood flow and retinal artery diameter, together with the neurofilament light chain (NF-L) content, retinal morphology, and axon density of the optic nerve, were evaluated at 2, 4, and 8 weeks after the first injection of ET-1 (n=7 or 8). Tissue blood velocity in ONH was measured using a laser speckle method, and the diameter of major retinal arteries on the rim of the ONH was calculated from fundus photographs by a masked observer. Histological analysis and immunoblot evaluation of NF-L in the optic nerve were performed to evaluate optic nerve damage. At 2 weeks after the first ET-1 injection, tissue blood velocity was decreased by approximately 20% (versus the contralateral eye), and the diameter of retinal arteries had decreased by approximately 40%. These changes were sustained at the same level until 8 weeks after the first ET-1 injection. At 4 and 8 weeks after the first ET-1 injection, the amount of NF-L in the optic nerve was significantly less in the ET-1 treated eyes than in the contralateral eyes. At 8 weeks after the first ET-1 injection, a loss of myelinated axons and increases in gliosis and connective tissue were noted in the optic nerve of the treated eye, and the optic nerve-axon number had decreased significantly (each, versus the untreated eye). Retinal ganglion cells in the retina were not observed any damage at 2, 4, and 8 weeks after ET-1 injection. In conclusion, intravitreal injection of ET-1 induced chronic hypoperfusion in the ONH and retina, which presumably caused decreases in NF-L content and axon number in the optic nerve noted in the later part of the observation period.
Collapse
Affiliation(s)
- Masaaki Sasaoka
- Glaucoma Group, Research and Development Center, Santen Pharmaceutical Co. Ltd., 8916-16 Takayama-cho, Ikoma 630-0101, Japan
| | | | | | | | | | | |
Collapse
|
23
|
Schuettauf F, Eibl KH, Thaler S, Shinoda K, Rejdak R, May CA, Blatsios G, Welge-Lussen U. Toxicity study of erucylphosphocholine in a rat model. Curr Eye Res 2005; 30:813-20. [PMID: 16146926 DOI: 10.1080/02713680591006093] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the effect of intraocular erucylphosphocholine (ErPC) on the retina, the retinal pigment epithelium (RPE), and the choroid in an in vivo rat model. METHODS Adult male Brown Norway rats were injected intravitreally with ErPC dissolved in balanced salt solution (BSS) at a final concentration of 10 or 100 microM with BSS serving as control. Adverse effects on the anterior and posterior segment were assessed by slit-lamp biomicroscopy and ophthalmoscopy. Retinal toxicity was assessed by electroretinography (ERG), retinal ganglion cell (RGC) quantification, and histology 7 days after intravitreal administration of ErPC. RESULTS There was neither a statistically significant difference in the clinical examination nor in the ERG waves of treated versus control rats 7 days after intravitreal administration of ErPC. Correspondingly, the number of RGC after BSS injection did not differ significantly from ErPC-injected animals. Histologic sections of the posterior segment of 10 and 100 microM ErPC-injected rats did not show any signs of retinal toxicity. Electron microscopy did not display a difference between the 10 microM and the control group. Only the 100 microM-injected animals showed a discrete irregularity of the Müller cell and the retinal ganglion cell cytoplasm at the ultrastructural level. CONCLUSIONS ErPC can safely be injected into the vitreous of adult rats at a concentration of 10 microM without any retinal toxicity. Even a 10-fold increase in ErPC concentration leads only to a discrete cytoplasmic irregularity of the innermost retinal layers.
Collapse
Affiliation(s)
- Frank Schuettauf
- Department of Ophthalmology, Eberhard Karls University, Tübingen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Osborne NN, Wood JPM, Chidlow G. Invited Review: Neuroprotective Properties of Certain β-Adrenoceptor Antagonists Used for the Treatment of Glaucoma. J Ocul Pharmacol Ther 2005; 21:175-81. [PMID: 15969634 DOI: 10.1089/jop.2005.21.175] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Although it is known that ganglion cell death causes loss of vision in glaucoma, the pathogenesis of the disease is complex, probably involving an initial ischemic insult to the ganglion cell axons and glial cells with the ganglion cell bodies eventually being affected. It may therefore be necessary to blunt many stages in the pathogenesis of the disease to obtain a clinically effective neuroprotective strategy. In animal experiments, one cause of ganglion cell death in ischemia is an overactivation of glutamate receptors and a subsequent rise in intracellular levels of sodium and calcium ions as well as a generation of reactive oxygen species. In contrast, optic nerve death in ischemia is mainly caused by an influx of sodium and reversal of the sodium/calcium exchanger, which leads to a rise in intracellular calcium. Thus, a substance that reduces the influx of sodium will protect the ganglion cell axon, and if it also reduces calcium influx and/or acts as an antioxidant it will protect the ganglion cell body in addition. Of all antiglaucoma drugs, only beta-blockers have both calcium and sodium channel blocking activity, with betaxolol being the most efficacious of those analyzed. In addition, of the tested ophthalmic beta-blockers only metipranolol has powerful antioxidant properties. Moreover, laboratory studies on rats have shown that topically applied beta-blockers attenuate ischemic injury to ganglion cells by mechanisms that do not appear to involve an action on beta-receptors. Thus, of the substances used to lower intraocular pressure in glaucoma, beta-blockers have unique additional characteristics that also give them the capacity to act as neuroprotectants.
Collapse
Affiliation(s)
- Neville N Osborne
- Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, United Kingdom.
| | | | | |
Collapse
|
25
|
Osborne NN, Chidlow G, Layton CJ, Wood JPM, Casson RJ, Melena J. Optic nerve and neuroprotection strategies. Eye (Lond) 2005; 18:1075-84. [PMID: 15534592 DOI: 10.1038/sj.eye.6701588] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Experimental studies have yielded a wealth of information related to the mechanism of ganglion cell death following injury either to the myelinated ganglion cell axon or to the ganglion cell body. However, no suitable animal models exist where injury can be directed to the optic nerve head region, particularly the unmyelinated ganglion cell axons. The process of relating the data from the various animal models to many different types of optic neuropathies in man must, therefore, be cautious. RESULTS Extensive studies on the isolated optic nerve have yielded valuable information on the way white matter is affected by ischaemia and how certain types of compounds can attenuate the process. Moreover, there are now persuasive data on how ganglion cell survival is affected when the ocular blood flow is reduced in various animal models. As a consequence, the molecular mechanisms involved in ganglion cell death are fairly well understood and various pharmacological agents have been shown to blunt the process when delivered before or shortly after the insult. CONCLUSIONS A battery of agents now exist that can blunt animal ganglion cell death irrespective of whether the insult was to the ganglion cell body or the myelinated axon. Whether this information can be applied for use in patients remains a matter of debate, and major obstacles need to be overcome before the laboratory studies may be applied clinically. These include the delivery of the pharmacological agents to the site of ganglion cell injury and side effects to the patients. Moreover, it is necessary to establish whether effective neuroprotection is only possible when the drug is administered at a defined time after injury to the ganglion cells. This information is essential in order to pursue the idea that a neuroprotective strategy can be applied to a disease like glaucoma, where ganglion cell death appears to occur at different times during the lifetime of the patient.
Collapse
Affiliation(s)
- N N Osborne
- Nuffield Laboratory of Ophthalmology, Oxford University, Oxford, UK.
| | | | | | | | | | | |
Collapse
|
26
|
Yamamoto R, Yoneda S, Hara H. Neuroprotective effects of beta-secretase inhibitors against rat retinal ganglion cell death. Neurosci Lett 2005; 370:61-4. [PMID: 15489018 DOI: 10.1016/j.neulet.2004.07.087] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 07/20/2004] [Accepted: 07/29/2004] [Indexed: 10/26/2022]
Abstract
Beta-secretase, an enzyme participating in amyloid beta-peptide generation, is thought to be involved in the pathogenesis of Alzheimer's disease. We examined the effects of beta-secretase inhibitors such as N-benzyloxycarbonyl-Val-Leu-leucinal (Z-VLL-CHO) and H-EVNstatineVAEF-NH2 (GL-189) on glutamate-induced retinal ganglion cell (RGC) death in vitro. In cultures of purified RGCs from neonatal rats, 2-day exposure to 25 microM glutamate induced RGC death, and Z-VLL-CHO (100 nM) and GL-189 (1 microM) had neuroprotective effects. We also found out that Z-VLL-CHO showed a neuroprotective effect on retinal damage induced by optic nerve crush in vivo. Thus, beta-secretase could be a potential target for therapy of neurodegenerative retinal diseases.
Collapse
Affiliation(s)
- Rie Yamamoto
- Research and Development Center, Santen Pharmaceutical Co. Ltd., 8916-16 Takayama-cho, Ikoma 630-0101, Japan
| | | | | |
Collapse
|
27
|
Kipnis J, Avidan H, Caspi RR, Schwartz M. Dual effect of CD4+CD25+ regulatory T cells in neurodegeneration: a dialogue with microglia. Proc Natl Acad Sci U S A 2004; 101 Suppl 2:14663-9. [PMID: 15331781 PMCID: PMC521988 DOI: 10.1073/pnas.0404842101] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Autoimmune CD4(+) T cells can mediate the ability to withstand neurodegenerative conditions. Here we show that the ability to spontaneously manifest a T cell-dependent protective response is restricted by naturally occurring CD4(+)CD25(+) regulatory T cells (Treg); depletion of Treg was beneficial in two mouse strains (C57BL/6J and BALB/c/OLA) differing in their spontaneous T cell-dependent ability to withstand the consequences of optic nerve injury. Passive transfer of exogenous Treg was destructive in BALB/c/OLA mice (which can spontaneously manifest a T cell-dependent protective anti-self response to injury) but beneficial in C57BL/6J mice (which have only limited ability to manifest such a response). This dichotomy was resolved by the finding that, in severe combined immunodeficient mice, a beneficial effect is obtained by passive transfer of either Treg-free CD4(+) T cells (Teff) or Treg alone, indicating that neuroprotection can be achieved by either Treg or Teff in the absence of the other. We attribute these disparate effects of Treg to their differential interaction (in part via IL-10 and transforming growth factor beta) with local innate immune cells (microglia) in the presence and in the absence of effector T cells. Activation of microglia by pro- and antiinflammatory cytokines in suitably controlled amounts might trigger different signal transduction pathways, each of which induces a neuroprotective microglial phenotype. These results suggest that, under neurodegenerative conditions, the effects of Treg, and possibly also of other regulatory T cells, might not be uniform, and that their expression in different individuals might be genetically determined. Therefore, therapeutic intervention based on induction of regulatory T cells might have limitations.
Collapse
Affiliation(s)
- Jonathan Kipnis
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | | | | | | |
Collapse
|
28
|
Poulsen CF, Simeone TA, Maar TE, Smith-Swintosky V, White HS, Schousboe A. Modulation by topiramate of AMPA and kainate mediated calcium influx in cultured cerebral cortical, hippocampal and cerebellar neurons. Neurochem Res 2004; 29:275-82. [PMID: 14992287 DOI: 10.1023/b:nere.0000010456.92887.3b] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The effect of the antiepileptic drug topiramate on Ca2+ uptake through (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionate (AMPA) and kainate (KA) receptors was investigated in different cell culture systems consisting of neurons from the cerebral cortex, hippocampus, and cerebellum. Ca2+ influx was assayed using a fluorescent Ca2+ chelator to monitor changes in the intracellular Ca2+ concentration or cobalt staining to assess the effect of topiramate on Ca2+-permeable AMPA/KA receptors. In all types of neuronal cultures studied, AMPA and KA were found to elicit an influx of Ca2+ in a subset of the neuronal population. Topiramate, at concentrations of 30 and 100 microM, inhibited Ca2+ influx by up to 60%. Modulation of AMPA and KA-evoked Ca2+ influx may contribute to both the antiepileptic and neuroprotective properties of topiramate.
Collapse
Affiliation(s)
- Claus F Poulsen
- Department of Pharmacology, The Danish University of Pharmaceutical Sciences, Copenhagen, Denmark
| | | | | | | | | | | |
Collapse
|
29
|
Taniguchi T, Shimazawa M, Hara H. Alterations in neurofilament light in optic nerve in rat kainate and monkey ocular hypertension models. Brain Res 2004; 1013:241-8. [PMID: 15193534 DOI: 10.1016/j.brainres.2004.04.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2004] [Indexed: 11/30/2022]
Abstract
The purpose of this study is to evaluate the changes in neurofilament light (NF-L) protein in the optic nerve in rat kainate and monkey ocular hypertension models. In the rat model, optic nerve damage was induced by kainate injection into the vitreous body. In the monkey model, photocoagulation of the trabecular meshwork led to laser-induced ocular hypertension. NF-L in optic nerve extract was quantified by quantitative immunoblot using an imaging analyzer. The amount of NF-L in optic nerve was compared between normal and kainate-treated groups at 7 days after kainate injection. Specimens from rat optic nerves and retinas were evaluated histologically to examine the correlations between damage and amount of NF-L in the optic nerve. In monkeys, the amount of NF-L in the optic nerve was compared between control fellow and ocular hypertensive eyes. Injection of kainate induced morphological optic nerve and retinal damage in rats. The amount of NF-L in the optic nerve was significantly reduced in kainate-treated eyes (vs. normal eyes). The amount of NF-L correlated with the cell count in the ganglion cell layer and the axon number in the optic nerve at 7 days after kainate injection. Further, 6-cyano-7-nitro-quinoxaline-2,3-dione, a non N-methyl-D-aspartate receptor antagonist, suppressed the kainate-induced reduction in NF-L and retinal damage. In the monkey model, ocular hypertension and morphological optic nerve damage were shown by laser-treated eyes. The amount of NF-L in the optic nerve was reduced in laser-treated eyes. In conclusion, in rat kainate and monkey ocular hypertension models, immunoblot evaluation of NF-L shows the reduction of the amount of NF-L in the optic nerves of treated-eyes. The amount of NF-L correlated with the morphological retinal and optic nerve damage in rats. These findings indicate that immunoblot evaluation of NF-L in the optic nerve may provide a quantitative index of optic nerve damage.
Collapse
Affiliation(s)
- Takazumi Taniguchi
- Glaucoma Group, Research and Development Center, Santen Pharmaceutical Co., Ltd., 8916-16 Takayama-cho, Ikoma, Nara 630-0101, Japan
| | | | | |
Collapse
|
30
|
Goto W, Ichikawa M, Tanaka E, Hara H, Araie M. Bunazosin hydrochloride reduces glutamate-induced neurotoxicity in rat primary retinal cultures. Brain Res 2004; 1003:130-7. [PMID: 15019572 DOI: 10.1016/j.brainres.2003.12.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2003] [Indexed: 11/29/2022]
Abstract
To study neuroprotective effects of bunazosin hydrochloride which is an alpha(1)-adrenoceptor antagonist used as an ocular hypotensive drug compared to other alpha(1)-adrenoceptor antagonists, and its mechanism of action. We evaluated the neuroprotective effects of bunazosin hydrochloride or seven other alpha(1)-adrenoceptor antagonists against glutamate-induced cell death in rat primary retinal cultures. We also evaluated the binding inhibition of bunazosin hydrochloride for 24 different receptors/channels and its effects on the Na(+) influx into cells induced by veratridine or glutamate. Bunazosin hydrochloride significantly inhibited glutamate-induced cell death at concentrations of 1 and 10 microM. Cells were also protected when treated with some alpha(1)-adrenoceptor antagonists, but not by the others. Bunazosin hydrochloride showed a high inhibition for Na(+) channels and inhibited the Na(+) influx induced by veratridine or glutamate. These findings indicate that in retinal cultures bunazosin hydrochloride has a neuroprotective effect against glutamate-induced cell death and that the inhibition of Na(+) channels by bunazosin hydrochloride may be partly responsible for this effect.
Collapse
Affiliation(s)
- Wakana Goto
- Ophthalmic Research and Development Division, Santen Pharmaceutical Co Ltd, 8916-16 Takayama-cho, Ikoma 630-0101, Nara, Japan
| | | | | | | | | |
Collapse
|
31
|
Osborne NN, Casson RJ, Wood JPM, Chidlow G, Graham M, Melena J. Retinal ischemia: mechanisms of damage and potential therapeutic strategies. Prog Retin Eye Res 2004; 23:91-147. [PMID: 14766318 DOI: 10.1016/j.preteyeres.2003.12.001] [Citation(s) in RCA: 737] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Retinal ischemia is a common cause of visual impairment and blindness. At the cellular level, ischemic retinal injury consists of a self-reinforcing destructive cascade involving neuronal depolarisation, calcium influx and oxidative stress initiated by energy failure and increased glutamatergic stimulation. There is a cell-specific sensitivity to ischemic injury which may reflect variability in the balance of excitatory and inhibitory neurotransmitter receptors on a given cell. A number of animal models and analytical techniques have been used to study retinal ischemia, and an increasing number of treatments have been shown to interrupt the "ischemic cascade" and attenuate the detrimental effects of retinal ischemia. Thus far, however, success in the laboratory has not been translated to the clinic. Difficulties with the route of administration, dosage, and adverse effects may render certain experimental treatments clinically unusable. Furthermore, neuroprotection-based treatment strategies for stroke have so far been disappointing. However, compared to the brain, the retina exhibits a remarkable natural resistance to ischemic injury, which may reflect its peculiar metabolism and unique environment. Given the increasing understanding of the events involved in ischemic neuronal injury it is hoped that clinically effective treatments for retinal ischemia will soon be available.
Collapse
Affiliation(s)
- Neville N Osborne
- Nuffield Laboratory of Ophthalmology, University of Oxford, Walton Street, Oxford OX2 6AW, UK.
| | | | | | | | | | | |
Collapse
|