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Perdices L, Fuentes-Broto L, Segura F, Cavero A, Orduna-Hospital E, Insa-Sánchez G, Sánchez-Cano AI, Fernández-Sánchez L, Cuenca N, Pinilla I. Systemic epigallocatechin gallate protects against retinal degeneration and hepatic oxidative stress in the P23H-1 rat. Neural Regen Res 2022; 17:625-631. [PMID: 34380903 PMCID: PMC8504391 DOI: 10.4103/1673-5374.320990] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/08/2020] [Accepted: 01/13/2021] [Indexed: 11/21/2022] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited retinal disorders that lead to photoreceptor loss. RP has been reported to be related to oxidative stress, autophagy, and inflammation. (-)-Epigallocatechin gallate (EGCG), the most abundant catechin-based flavonoid in green tea leaves, has significant antioxidant, anti-carcinogenic, antimicrobial, and neuroprotective properties. EGCG, given its low molecular weight and hydrophilic properties, can cross the blood-retinal barrier and is able to reach different ocular tissues such as the lens, cornea, and retina. EGCG has been shown to provide retinal protection against ischemia; sodium nitroprusside-, N-methyl-D-aspartate-, lipopolysaccharide-, light-, sodium iodate-, or H2O2-induced damage and diabetic retinopathy. This suggests that systemic EGCG administration has the potential to protect against retinal degenerative or neurodegenerative diseases such as RP. The aim of this work was to investigate whether EGCG can protect against RP progression in the animal P23H line 1, the model of RP. Albino P23H rats were crossed with pigmented Long Evans rats to produce offspring exhibiting the clinical features of RP. Pigmented P23H rats were treated via intraperitoneal injection with saline or EGCG at a dose of 25 mg/kg every week from P100 to P160 and then compared to wild-type Long Evans rats. Rats treated with EGCG showed better visual and retinal electrical function with increased contrast sensitivity and b-wave values compared with those observed in P23H rats treated with vehicle. EGCG reduced lipid peroxidation and increased total antioxidant capacity and catalase and superoxide dismutase activities. No differences were observed in visual acuity, nitrate levels, nitrite levels or glutathione S-transferase activity. In conclusion, EGCG not only reduced the loss of visual function in P23H rats but also improved the levels of antioxidant enzymes and reduced oxidative damage. This study was approved by the Institutional Animal Care and Use Committee (CEICA) from the University of Zaragoza under project license PI12/14 on July 11, 2014.
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Affiliation(s)
- Lorena Perdices
- Aragón Institute for Health Research (IIS Aragón), Zaragoza, Spain
| | - Lorena Fuentes-Broto
- Pharmacology, Physiology & Legal and Forensic Medicine, University of Zaragoza, Zaragoza, Spain
| | - Francisco Segura
- Department of Applied Physics, University of Zaragoza, Zaragoza, Spain
| | - Ana Cavero
- Health Sciences Faculty, San Jorge University, Villanueva de Gállego, Spain
| | | | - Gema Insa-Sánchez
- Pharmacology, Physiology & Legal and Forensic Medicine, University of Zaragoza, Zaragoza, Spain
| | | | - Laura Fernández-Sánchez
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Isabel Pinilla
- Department of Surgery, Gynecology and Obstetrics, University of Zaragoza, Zaragoza, Spain; Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza, Spain
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Mathew DJ, Livne-Bar I, Sivak JM. An inducible rodent glaucoma model that exhibits gradual sustained increase in intraocular pressure with distinct inner retina and optic nerve inflammation. Sci Rep 2021; 11:22880. [PMID: 34819548 PMCID: PMC8613281 DOI: 10.1038/s41598-021-02057-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/09/2021] [Indexed: 01/29/2023] Open
Abstract
Glaucoma is a chronic and progressive neurodegenerative disease of the optic nerve resulting in loss of retinal ganglion cells (RGCs) and vision. The most prominent glaucoma risk factor is increased intraocular pressure (IOP), and most models focus on reproducing this aspect to study disease mechanisms and targets. Yet, current models result in IOP profiles that often do not resemble clinical glaucoma. Here we introduce a new model that results in a gradual and sustained IOP increase over time. This approach modifies a circumlimbal suture method, taking care to make the sutures 'snug' instead of tight, without inducing an initial IOP spike. This approach did not immediately affect IOPs, but generated gradual ocular hypertension (gOHT) as the sutures tighten over time, in comparison to loosely sutured control eyes (CON), resulting in an average 12.6 mmHg increase in IOP at 17 weeks (p < 0.001). Corresponding characterization revealed relevant retinal and optic nerve pathology, such as thinning of the retinal nerve fiber layer, decreased optokinetic response, RGC loss, and optic nerve head remodeling. Yet, angles remained open, with no evidence of inflammation. Corresponding biochemical profiling indicated significant increases in TGF-β2 and 3, and IL-1 family cytokines in gOHT optic nerve tissues compared to CON, with accompanying microglial reactivity, consistent with active tissue injury and repair mechanisms. Remarkably, this signature was absent from optic nerves following acute ocular hypertension (aOHT) associated with intentionally tightened sutures, although the resulting RGC loss was similar in both methods. These results suggest that the pattern of IOP change has an important impact on underlying pathophysiology.
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Affiliation(s)
- David J Mathew
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Izhar Livne-Bar
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Jeremy M Sivak
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ON, Canada.
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada.
- Department of Lab Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada.
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Effects of Daily Melatonin Supplementation on Visual Loss, Circadian Rhythms, and Hepatic Oxidative Damage in a Rodent Model of Retinitis Pigmentosa. Antioxidants (Basel) 2021; 10:antiox10111853. [PMID: 34829724 PMCID: PMC8614953 DOI: 10.3390/antiox10111853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 01/02/2023] Open
Abstract
Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases characterized by a progressive loss of visual function that primarily affect photoreceptors, resulting in the complete disorganization and remodeling of the retina. Progression of the disease is enhanced by increased oxidative stress in the retina, aqueous humor, plasma, and liver of RP animal models and patients. Melatonin has beneficial effects against age-related macular degeneration, glaucoma, and diabetic retinopathy, in which oxidative stress plays a key role. In the present study, we used the P23HxLE rat as an animal model of RP. Melatonin treatment (10 mg/kg b.w. daily in drinking water for 6 months) improved the parameters of visual function and decreased the rate of desynchronization of the circadian rhythm, both in P23HxLE and wild-type rats. Melatonin reduced oxidative stress and increased antioxidant defenses in P23HxLE animals. In wild-type animals, melatonin did not modify any of the oxidative stress markers analyzed and reduced the levels of total antioxidant defenses. Treatment with melatonin improved visual function, circadian synchronization, and hepatic oxidative stress in P23HxLE rats, an RP model, and had beneficial effects against age-related visual damage in wild-type rats.
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Johnson NP, Gregorich SM, Passaglia CL. Spatiotemporal Contrast Sensitivity of Brown-Norway Rats under Scotopic and Photopic Illumination. Neuroscience 2020; 449:63-73. [PMID: 33035619 DOI: 10.1016/j.neuroscience.2020.09.056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/03/2020] [Accepted: 09/28/2020] [Indexed: 11/24/2022]
Abstract
Rats are a popular animal model for vision research and for investigating disorders of the visual system. The study aimed to quantify the spatiotemporal contrast sensitivity function (CSF) of healthy adult Brown-Norway rats under scotopic and photopic illumination. Animals were trained to jump onto the one of two adjacent platforms behind which was displayed a sinewave grating pattern. Contrast thresholds of light- and dark-adapted rats were determined using a staircase method of adjustment for gratings that varied in spatial frequency (sf) and temporal frequency (tf) and ranged several log-units in mean luminance. Photopic CSFs showed strong bandpass spatial tuning, consistent with prior measurements, and weak bandpass temporal tuning. CSFs were parameterized by a truncated log-parabola model, yielding a peak contrast sensitivity of 52 ± 9, peak sf of 0.17 ± 0.05 cycles/degree, sf limit of 1.6 ± 0.3 cycles/degree, low sf attenuation of 85 ± 9%, peak tf of 1.7 ± 1.1 Hz, extrapolated tf limit of 166 ± 44 Hz, and low tf attenuation of 55 ± 12%. CSFs became more lowpass and decreased systematically in contrast sensitivity and spatiotemporal acuity as mean luminance was reduced. CSFs were also measured via the visual head-tracking reflex. Photopic contrast sensitivity, spatial acuity, and temporal acuity were all markedly below that of the grating detection task and optomotor findings for other rat strains. The CSF data provide a comprehensive and quantitative description of rat spatial and temporal vision and a benchmark for evaluating effects of ocular diseases on their ability to see.
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Affiliation(s)
- Nicholas P Johnson
- University of South Florida, Molecular Pharmacology & Physiology Department, 12901 Bruce B Downs Boulevard MDC 40, Tampa, FL 33612, United States
| | - Sarah M Gregorich
- University of South Florida, Medical Engineering Department, 4202 E Fowler Avenue, Tampa, FL 33620, United States
| | - Christopher L Passaglia
- University of South Florida, Molecular Pharmacology & Physiology Department, 12901 Bruce B Downs Boulevard MDC 40, Tampa, FL 33612, United States; University of South Florida, Medical Engineering Department, 4202 E Fowler Avenue, Tampa, FL 33620, United States; University of South Florida, Ophthalmology Department, 12901 Bruce B Downs Boulevard MDC21, Tampa, FL 33612, United States.
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Perdices L, Fuentes-Broto L, Segura F, Cuenca N, Orduna-Hospital E, Pinilla I. Epigallocatechin Gallate Slows Retinal Degeneration, Reduces Oxidative Damage, and Modifies Circadian Rhythms in P23H Rats. Antioxidants (Basel) 2020; 9:antiox9080718. [PMID: 32784376 PMCID: PMC7465727 DOI: 10.3390/antiox9080718] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 12/31/2022] Open
Abstract
Retinitis pigmentosa (RP) includes a group of genetic disorders that involve the loss of visual function due to mutations mainly in photoreceptors but also in other retinal cells. Apoptosis, retinal disorganization, and inflammation are common in the progression of the disease. Epigallocatechin gallate (EGCG) has been proved as beneficial in different eye diseases. Pigmented heterozygous P23H rat was used as an animal model of RP. Visual function was assessed by optomotor and electroretinogram (ERG) and circadian rhythms were evaluated by telemetry. Hepatic oxidative damage and antioxidant defenses were assessed using biochemical tests. The visual function of the EGCG P23H group was preserved, with a deterioration in the activity period and lower values in the interdaily stability parameter. Control rats treated with EGCG were less active than the sham group. EGCG increased antioxidant levels in P23H rats but reduced total hepatic antioxidant capacity by almost 42% in control rats compared to the sham group. We conclude that treatment with EGCG improves visual function and antioxidant status in P23H rats but diminishes antioxidant defenses in wild-type control animals, and slightly worsens activity circadian rhythms. Further studies are necessary to clarify the beneficial effects in disease conditions and in healthy organisms.
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Affiliation(s)
- Lorena Perdices
- Aragon Institute for Health Research (IIS Aragón), 50009 Zaragoza, Spain; (L.P.); (I.P.)
| | - Lorena Fuentes-Broto
- Department of Pharmacology, Physiology and Legal and Forensic Medicine, Universidad de Zaragoza, 50009 Zaragoza, Spain
- Correspondence: ; Tel.: +34-976-761-706
| | - Francisco Segura
- Department of Applied Physics, Universidad de Zaragoza, 50009 Zaragoza, Spain;
| | - Nicolás Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, 03690 San Vicente del Raspeig, Alicante, Spain;
| | | | - Isabel Pinilla
- Aragon Institute for Health Research (IIS Aragón), 50009 Zaragoza, Spain; (L.P.); (I.P.)
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009 Zaragoza, Spain
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