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Lee TT, Bell BA, Anderson BD, Song Y, Dunaief JL. Tamoxifen protects photoreceptors in the sodium iodate model. Exp Eye Res 2024; 242:109879. [PMID: 38570182 PMCID: PMC11055656 DOI: 10.1016/j.exer.2024.109879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024]
Abstract
Because the selective estrogen receptor modulator tamoxifen was shown to be retina-protective in the light damage and rd10 models of retinal degeneration, the purpose of this study was to test whether tamoxifen is retina-protective in a model where retinal pigment epithelium (RPE) toxicity appears to be the primary insult: the sodium iodate (NaIO3) model. C57Bl/6J mice were given oral tamoxifen (in the diet) or the same diet lacking tamoxifen, then given an intraperitoneal injection of NaIO3 at 25 mg/kg. The mice were imaged a week later using optical coherence tomography (OCT). ImageJ with a custom macro was utilized to measure retinal thicknesses in OCT images. Electroretinography (ERG) was used to measure retinal function one week post-injection. After euthanasia, quantitative real-time PCR (qRT-PCR) was performed. Tamoxifen administration partially protected photoreceptors. There was less photoreceptor layer thinning in OCT images of tamoxifen-treated mice. qRT-PCR revealed, in the tamoxifen-treated group, less upregulation of antioxidant and complement factor 3 mRNAs, and less reduction in the rhodopsin and short-wave cone opsin mRNAs. Furthermore, ERG results demonstrated preservation of photoreceptor function for the tamoxifen-treated group. Cone function was better protected than rods. These results indicate that tamoxifen provided structural and functional protection to photoreceptors against NaIO3. RPE cells were not protected. These neuroprotective effects suggest that estrogen-receptor modulation may be retina-protective. The fact that cones are particularly protected is intriguing given their importance for human visual function and their survival until the late stages of retinitis pigmentosa. Further investigation of this protective pathway could lead to new photoreceptor-protective therapeutics.
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Affiliation(s)
- Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ying Song
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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Anderson BD, Lee TT, Bell BA, Wang T, Dunaief JL. Optimizing the sodium iodate model: Effects of dose, gender, and age. Exp Eye Res 2024; 239:109772. [PMID: 38158173 PMCID: PMC10922497 DOI: 10.1016/j.exer.2023.109772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/26/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024]
Abstract
Sodium iodate (NaIO3) is a commonly used model for age-related macular degeneration (AMD), but its rapid and severe induction of retinal pigment epithelial (RPE) and photoreceptor degeneration can lead to the premature dismissal of potentially effective therapeutics. Additionally, little is known about how sex and age affect the retinal response to NaIO3. This study aims to establish a less severe yet reproducible regimen by testing low doses of NaIO3 while considering age- and sex-related effects, enabling a broader range of therapeutic evaluations. In this study, young (3-5 months) and old (18-24 months) male and female C57Bl/6J mice were given an intraperitoneal (IP) injection of 15, 20, or 25 mg/kg NaIO3. Damage assessment one week post-injection included in vivo imaging, histological examination, and qRT-PCR analysis. The results revealed that young mice showed no damage at 15 mg/kg IP NaIO3, with varying degrees of damage observed at 20 mg/kg. At 25 mg/kg, most young mice displayed widespread retinal damage, with females exhibiting less retinal thinning than males. In contrast, older mice at 20 and 25 mg/kg displayed a more patchy degeneration pattern, outer retinal undulations, and greater variability in degeneration than the young mice. The most effective model for minimizing damage while maintaining consistency utilizes young female mice injected with 25 mg/kg NaIO3. The observed sex- and age-related differences underscore the importance of considering these variables in research, aligning with the National Institutes of Health's guidance. While the model does not fully replicate the complexity of AMD, these findings enhance its utility as a valuable tool for testing RPE/photoreceptor protective or replacement therapies.
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Affiliation(s)
- Brandon D Anderson
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Timothy T Lee
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Brent A Bell
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Tan Wang
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA; Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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3
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Goo H, Lee MY, Lee YJ, Lee S, Ahn JC, Hong N. Multi-Wavelength Photobiomodulation Ameliorates Sodium Iodate-Induced Age-Related Macular Degeneration in Rats. Int J Mol Sci 2023; 24:17394. [PMID: 38139223 PMCID: PMC10743884 DOI: 10.3390/ijms242417394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/01/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023] Open
Abstract
Age-related macular degeneration (AMD) is a global health challenge. AMD causes visual impairment and blindness, particularly in older individuals. This multifaceted disease progresses through various stages, from asymptomatic dry to advanced wet AMD, driven by various factors including inflammation and oxidative stress. Current treatments are effective mainly for wet AMD; the therapeutic options for dry AMD are limited. Photobiomodulation (PBM) using low-energy light in the red-to-near-infrared range is a promising treatment for retinal diseases. This study investigated the effects of multi-wavelength PBM (680, 780, and 830 nm) on sodium iodate-induced oxidatively damaged retinal tissue. In an in vivo rat model of AMD induced by sodium iodate, multi-wavelength PBM effectively protected the retinal layers, reduced retinal apoptosis, and prevented rod bipolar cell depletion. Furthermore, PBM inhibited photoreceptor degeneration and reduced retinal pigment epithelium toxicity. These results suggest that multi-wavelength PBM may be a useful therapeutic strategy for AMD, mitigating oxidative stress, preserving retinal integrity, and preventing apoptosis.
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Affiliation(s)
- Hyeyoon Goo
- Department of Medical Laser, Graduate School of Medicine, Dankook University, Cheonan 31116, Republic of Korea;
- Beckman Laser Institute-Korea, Dankook University, Cheonan 31116, Republic of Korea; (M.Y.L.); (Y.-J.L.)
| | - Min Young Lee
- Beckman Laser Institute-Korea, Dankook University, Cheonan 31116, Republic of Korea; (M.Y.L.); (Y.-J.L.)
- Department of Otolaryngology-Head & Neck Surgery, College of Medicine, Dankook University Hospital, Dankook University, Cheonan 31116, Republic of Korea
| | - Yea-Jin Lee
- Beckman Laser Institute-Korea, Dankook University, Cheonan 31116, Republic of Korea; (M.Y.L.); (Y.-J.L.)
| | - Sangkeun Lee
- MEDI-IOT Co., Ltd., Seoul 02708, Republic of Korea;
| | - Jin-Chul Ahn
- Beckman Laser Institute-Korea, Dankook University, Cheonan 31116, Republic of Korea; (M.Y.L.); (Y.-J.L.)
| | - Namgue Hong
- Beckman Laser Institute-Korea, Dankook University, Cheonan 31116, Republic of Korea; (M.Y.L.); (Y.-J.L.)
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Iwagawa T, Saita K, Sagara H, Watanabe S. Downregulation of VEGF in the retinal pigment epithelium followed by choriocapillaris atrophy after NaIO3 treatment in mice. Exp Eye Res 2023; 234:109598. [PMID: 37479076 DOI: 10.1016/j.exer.2023.109598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023]
Abstract
Sodium iodate (NaIO3) induces retinal pigment epithelium (RPE) dysfunction, which leads to photoreceptor degeneration. Previously, we used electron microscopy to show that the administration of NaIO3 resulted in the accumulation of cell debris in the subretinal space, which was thought to be caused by failed phagocytosis in the outer segment of the photoreceptor due to RPE dysfunction. We further analyzed the pathological changes in the retina and choroid of NaIO3-injected mice, and found that the expression of OTX2, an RPE marker, disappeared from central part of the RPE 1 day after NaIO3 administration. Furthermore, fenestrated capillaries (choriocapillaris, CC) adjacent to the RPE could not be identified only 2 days after NaIO3 administration. An examination of the expression of the CC-specific protein plasmalemma vesicle-associated protein (PLVAP), in sections and flat-mount retina/choroid specimens showed destruction of the CC, and complete disappearance of the PLVAP signal 7 days after NaIO3 administration. In contrast, CD31 flat-mount immunohistochemistry of the retina indicated no difference in retinal vessels between NaIO3-treated mice and controls. Electron microscopy showed that the fenestrated capillaries in the kidney and duodenum were morphologically indistinguishable between control and NaIO3-treated mice. We examined cytokine production in the retina and RPE, and found that the Vegfa transcript level in the RPE decreased starting 1 day after NaIO3 administration. Taken together, these observations show that NaIO3 reduces the CC in the early stages of the pathology, which is accompanied by a rapid decrease in Vegfa expression in the RPE.
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Affiliation(s)
- Toshiro Iwagawa
- Department of Retinal Biology and Pathology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Kosuke Saita
- Department of Retinal Biology and Pathology, Graduate School of Medicine, The University of Tokyo, Japan; Department of Anesthesiology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Hiroshi Sagara
- Medical Proteomics Laboratory, Institute of Medical Science, The University of Tokyo, Japan
| | - Sumiko Watanabe
- Department of Retinal Biology and Pathology, Graduate School of Medicine, The University of Tokyo, Japan.
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Chen W, Lin B, Xie S, Yang W, Lin J, Li Z, Zhan Y, Gui S, Lin B. Naringenin protects RPE cells from NaIO 3-induced oxidative damage in vivo and in vitro through up-regulation of SIRT1. Phytomedicine 2021; 80:153375. [PMID: 33096452 DOI: 10.1016/j.phymed.2020.153375] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 07/15/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Dry age-related macular degeneration (dAMD) leads to serious burden of visual impairment and there is no definitive treatment. Previous studies have showed that naringenin (NAR) significantly increased electroretinography (ERG) c-wave in sodium iodate (NaIO3)-treated rats and viability of NaIO3-treated ARPE-19 cells. But the underlying mechanism is still unknown. PURPOSE We tested the hypothesis that anti-oxidation mediated by Sirtuin 1 (SIRT1) was important to the protective effect of NAR on dAMD. STUDY DESIGN/METHODS NaIO3-induced mice retinopathy and ARPE-19 cells injury models were established. In vivo, the protective effect of NAR eye drops on retina was evaluated by flash ERG (FERG) recording and histopathological examination. In vitro, viability of ARPE-19 cells, and the levels of lactic dehydrogenase (LDH), reactive oxygen species (ROS) and carbonyl protein were detected. Protein expression of SIRT1 was analyzed by immunochemical staining, immunofluorescence and western blotting. RESULTS NAR eye drops improved retinal function and morphology and normalized the protein expression of SIRT1 in mice exposed to NaIO3. NAR promoted the survival of ARPE-19 cells in a concentration-dependent manner. NAR up-regulated SIRT1 protein expression, and decreased levels of ROS and carbonyl protein. Moreover, EX527, a selective inhibitor of SIRT1, abolished the effects of NAR on the cell viability and ROS. In addition, SRT1720, a selective agonist of SIRT1, improved the viability of cells and suppressed the production of ROS. CONCLUSION Our findings indicate that SIRT1-mediated anti-oxidation contributes to the protective effect of NAR eye drops on dAMD.
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Affiliation(s)
- Wenpei Chen
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China; Guangdong Provincial Key Laboratory of Drug Non-clinical Evaluation and Research, Guangdong Lewwin Pharmaceutical Research Institute Co., Ltd., Guangzhou, Guangdong, 510990, China
| | - Bingqing Lin
- College of Mathematics and Statistics, Shenzhen University, Shenzhen, Guangdong, 518060, China
| | - Shichuan Xie
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China
| | - Wei Yang
- Guangdong Provincial Key Laboratory of Drug Non-clinical Evaluation and Research, Guangdong Lewwin Pharmaceutical Research Institute Co., Ltd., Guangzhou, Guangdong, 510990, China
| | - Junli Lin
- Guangdong Provincial Key Laboratory of Drug Non-clinical Evaluation and Research, Guangdong Lewwin Pharmaceutical Research Institute Co., Ltd., Guangzhou, Guangdong, 510990, China
| | - Zhaojia Li
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China
| | - Yaxian Zhan
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China
| | - Shuhua Gui
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China
| | - Baoqin Lin
- School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China.
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Kim HR, Kim S, Lee SW, Sin HS, Kim SY. Protective Effects of Fermented Paprika ( Capsicum annuum L.) on Sodium Iodate-Induced Retinal Damage. Nutrients 2020; 13:nu13010025. [PMID: 33374795 PMCID: PMC7824181 DOI: 10.3390/nu13010025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/15/2020] [Accepted: 12/21/2020] [Indexed: 02/08/2023] Open
Abstract
Diseases of the outer retina, including age-related macular degeneration (AMD), are major cause of permanent visual damage. The pathogenesis of AMD involves oxidative stress and damage of the retinal pigment epithelium. Capsicum annuum L. (paprika) fruits have been known as a source of vitamins, carotenoids, phenolic compounds, and metabolites with a well-known antioxidant activity, which have positive effects on human health and protection against AMD and cataracts. In this study, we investigated whether paprika (fermented (FP), yellow, and orange colored) fermented with Lactobacillus (L.) plantarum could increase the protective effect of retinal degeneration using in vitro and in vivo models. FP significantly increased cell survival and reduced levels of lactate dehydrogenase as well as intracellular reactive oxygen species (ROS) increase in SI (sodium iodate, NaIO3)-treated human retinal pigment epithelial (ARPE-19) cells. We developed a model of retinal damage in C57BL/6 mice using SI (30 mg/kg) via intraperitoneal injection. Seven days after SI administration, deformation and a decrease in thickness were observed in the outer nuclear layer, but improved by FP treatment. FP administration protected the SI-mediated reduction of superoxide dismutase and glutathione levels in the serum and ocular tissues of mice. The overproduction of cleaved poly(ADP-Ribose) Polymerase (PARP)1, caspase-3 and -8 proteins were significantly protected by FP in SI-treated cells and ocular tissues. In addition, we evaluated the potentiating effects of FP on antioxidants and their underlying mechanisms in RAW 264.7 cells. Lipopolysaccharide (LPS)-induced nitrite increase was markedly blocked by FP treatment in RAW 264.7 cells. Furthermore, FP reduced LPS-induced inducible nitric oxide synthase and cyclooxygenase-2 activation. The FP also enhanced the inhibitory effects on mitogen activated kinase signaling protein activation in ARPE-19 and RAW 264.7 cells and ocular tissues. There was no significant difference in total phenol and flavonoid content in paprika by fermentation, but the vitamin C content was increased in orange colored paprika, and protective effect against oxidative stress-mediated retinal damage was enhanced after fermentation. These results suggest that FP may be a potential candidate to protect against retinal degenerative diseases through the regulation of oxidative stress.
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Affiliation(s)
- Ha-Rim Kim
- Jeonju AgroBio-Materials Institute, Wonjangdong-gil 111-27, Deokjin-gu, Jeonju-si, Jeollabuk-do 54810, Korea; (H.-R.K.); (S.K.)
| | - Sol Kim
- Jeonju AgroBio-Materials Institute, Wonjangdong-gil 111-27, Deokjin-gu, Jeonju-si, Jeollabuk-do 54810, Korea; (H.-R.K.); (S.K.)
| | - Sang-Wang Lee
- Chebigen Co., Ltd., Jeonju 54853, Korea; (S.-W.L.); (H.-S.S.)
| | - Hong-Sig Sin
- Chebigen Co., Ltd., Jeonju 54853, Korea; (S.-W.L.); (H.-S.S.)
| | - Seon-Young Kim
- Jeonju AgroBio-Materials Institute, Wonjangdong-gil 111-27, Deokjin-gu, Jeonju-si, Jeollabuk-do 54810, Korea; (H.-R.K.); (S.K.)
- Correspondence: ; Tel.: +82-63-711-1053
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Jang KH, Hwang Y, Kim E. PARP1 Impedes SIRT1-Mediated Autophagy during Degeneration of the Retinal Pigment Epithelium under Oxidative Stress. Mol Cells 2020; 43:632-644. [PMID: 32732457 PMCID: PMC7398797 DOI: 10.14348/molcells.2020.0078] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/23/2020] [Accepted: 06/05/2020] [Indexed: 01/01/2023] Open
Abstract
The molecular mechanism underlying autophagy impairment in the retinal pigment epithelium (RPE) in dry age-related macular degeneration (AMD) is not yet clear. Based on the causative role of poly(ADP-ribose) polymerase 1 (PARP1) in RPE necrosis, this study examined whether PARP1 is involved in the autophagy impairment observed during dry AMD pathogenesis. We found that autophagy was downregulated following H2O2-induced PARP1 activation in ARPE-19 cells and olaparib, PARP1 inhibitor, preserved the autophagy process upon H2O2 exposure in ARPE-19 cells. These findings imply that PARP1 participates in the autophagy impairment upon oxidative stress in ARPE-19 cells. Furthermore, PARP1 inhibited autolysosome formation but did not affect autophagosome formation in H2O2-exposed ARPE-19 cells, demonstrating that PARP1 is responsible for impairment of late-stage autophagy in particular. Because PARP1 consumes NAD+ while exerting its catalytic activity, we investigated whether PARP1 impedes autophagy mediated by sirtuin1 (SIRT1), which uses NAD+ as its cofactor. A NAD+ precursor restored autophagy and protected mitochondria in ARPE-19 cells by preserving SIRT1 activity upon H2O2. Moreover, olaparib failed to restore autophagy in SIRT1-depleted ARPE-19 cells, indicating that PARP1 inhibits autophagy through SIRT1 inhibition. Next, we further examined whether PARP1-induced autophagy impairment occurs in the retinas of dry AMD model mice. Histological analyses revealed that olaparib treatment protected mouse retinas against sodium iodate (SI) insult, but not in retinas cotreated with SI and wortmannin, an autophagy inhibitor. Collectively, our data demonstrate that PARP1-dependent inhibition of SIRT1 activity impedes autophagic survival of RPE cells, leading to retinal degeneration during dry AMD pathogenesis.
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Affiliation(s)
- Ki-Hong Jang
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
| | - Yeseong Hwang
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
| | - Eunhee Kim
- Department of Biological Sciences, Chungnam National University, Daejeon, Korea
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Li R, Liu Y, Xie J, Huang X, Zhang L, Liu H, Li L. Sirt3 mediates the protective effect of hydrogen in inhibiting ROS-induced retinal senescence. Free Radic Biol Med 2019; 135:116-124. [PMID: 30735837 DOI: 10.1016/j.freeradbiomed.2019.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/30/2019] [Accepted: 02/04/2019] [Indexed: 02/07/2023]
Abstract
Hydrogen possesses antioxidative effects and cures numerous types of ophthalmopathy, but the mechanism of hydrogen on ROS-induced retinal senescence remains elusive. In this study, retinal morphology revealed that hydrogen reduced the number and size of vitreous black deposits in Bruch's membrane in NaIO3 mice. Hydrogen also reduced ROS levels in the retina as assessed by DHE staining. Moreover, this result was consistent with the downregulation of expression of the oxidative stress hallmark OGG1. These findings suggested that hydrogen can reduce retinal oxidative stress induced by NaIO3, and this result was further verified using the antioxidant ALCAR. Mechanistic analysis revealed that hydrogen significantly inhibited the downregulation of Sirt3 expression, and this notion was confirmed using AICAR, which restores Sirt3 expression and activity. Moreover, hydrogen reduced the expression of p53, p21 and p16 and the number of blue-green precipitations in the retinas of NaIO3 mice as assessed by SA-β-gal staining. We also found that hydrogen decreased the expression of the DNA damage-related protein ATM, cyclinD1 and NF-κB but increased the expression of the DNA repair-related protein HMGB1, suggesting that hydrogen inhibits senescence in retinas of NaIO3 mice. Additionally, OCT examination revealed that hydrogen suppressed retinal high reflex formation significantly and prevented the retina from thinning. This result was supported by ERG assays that demonstrated that hydrogen prevented the reduction in a- and b-wave amplitude induced by NaIO3 in mice. Thus, our data suggest that hydrogen may inhibit retinal senescence by suppressing the downregulation of Sirt3 expression through reduced oxidative stress reactions.
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Affiliation(s)
- Ruichan Li
- Department of Cell Biology, Taizhou University, Taizhou, PR China.
| | - Yanli Liu
- Department of Cell Biology, Taizhou University, Taizhou, PR China.
| | - Jing Xie
- Department of Cell Biology, Taizhou University, Taizhou, PR China.
| | - Xudong Huang
- Chemistry and Life College, Chengdu Normal University, Chengdu, PR China.
| | - Li Zhang
- Jinzhoushi Oral Cavity Hospital, Jinzhou, PR China.
| | - Hua Liu
- Department of Cell Biology, Jinzhou Medical University, Jinzhou, PR China.
| | - Lihua Li
- Department of Cell Biology, Taizhou University, Taizhou, PR China.
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Liu H, Hou C, Zeng Q, Zhao L, Cui Y, Yu L, Wang L, Zhao Y, Nie J, Zhang B, Wang A. Role of endoplasmic reticulum stress-induced apoptosis in rat thyroid toxicity caused by excess fluoride and/or iodide. Environ Toxicol Pharmacol 2016; 46:277-285. [PMID: 27522547 DOI: 10.1016/j.etap.2016.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 06/06/2023]
Abstract
Excess fluoride and iodide coexist in drinking water in many regions, but few studies have investigated the single or interactive effects on thyroid in vivo. In our study, Wistar rats were exposed to excess fluoride and/or iodide through drinking water for 2 or 8 months. The structure and function of the thyroid, cells apoptosis and the expression of inositol-requiring enzyme 1 (IRE1) pathway-related factors were analyzed. Results demonstrated that excess fluoride and/or iodide could change thyroid follicular morphology and alter thyroid hormone levels in rats. After 8 months treatment, both single and co-exposure of the two microelements could raise the thyroid cells apoptosis. However, the expressions of IRE1-related factors were only increased in fluoride-alone and the combined groups. In conclusion, thyroid structure and thyroid function were both affected by excess fluoride and/or iodide. IRE1-induced apoptosis were involved in this cytotoxic process caused by fluoride or the combination of two microelements.
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Affiliation(s)
- Hongliang Liu
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, PR China; School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, PR China.
| | - Changchun Hou
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, PR China
| | - Qiang Zeng
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, PR China
| | - Liang Zhao
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, PR China
| | - Yushan Cui
- Tianjin Centers for Disease Control and Prevention, 6 Huayue Road, Hedong District, Tianjin 300011, PR China
| | - Linyu Yu
- Tanggu Center for Disease Control and Prevention, 43 Fujiang Road, Tianjin Binhai New Area, Tianjin 300450, PR China
| | - Lingzhi Wang
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, PR China
| | - Yang Zhao
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, PR China
| | - Junyan Nie
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, PR China
| | - Bin Zhang
- School of Public Health, Tianjin Medical University, 22 Qixiangtai Road, Heping District, Tianjin 300070, PR China
| | - Aiguo Wang
- Department of Environmental Health and MOE Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030 Hubei, PR China.
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10
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Allard S, Tan J, Joll CA, von Gunten U. Mechanistic Study on the Formation of Cl-/Br-/I-Trihalomethanes during Chlorination/Chloramination Combined with a Theoretical Cytotoxicity Evaluation. Environ Sci Technol 2015; 49:11105-14. [PMID: 26280905 DOI: 10.1021/acs.est.5b02624] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Chlorination followed by chloramination can be used to mitigate the formation of potentially toxic iodinated disinfection byproducts (I-DBPs) while controlling the formation of regulated chloro-bromo-DBPs (Cl-/Br-DBPs). Water samples containing dissolved organic matter (DOM) isolates were subjected to 3 disinfection scenarios: NH2Cl, prechlorination followed by ammonia addition, and HOCl alone. A theoretical cytotoxicity evaluation was carried out based on the trihalomethanes (THMs) formed. This study demonstrates that the presence of bromide not only enhances the yield and rate of iodate formation, it also increases the formation of brominated I-THM precursors. A shift in the speciation from CHCl2I to the more toxic CHBr2I, as well as increased iodine incorporation in THMs, was observed in the presence of bromide. For low bromide concentrations, a decrease in I-THM formation and theoretical cytotoxicity was achieved only for high prechlorination times, while for high bromide concentrations, a short prechlorination time enabled the full conversion of iodide to iodate. For low DOM concentrations or DOM with low reactivity, Br-/I-THMs were preferentially formed for short prechlorination times, inducing high cytotoxicity. However, for high chlorine exposures, the cytotoxicity induced by the formation of regulated THMs might outweigh the benefit of I-THM mitigation. For high DOM concentrations or DOM with higher reactivity, mixed I-THMs were formed together with high concentrations of regulated THMs. In this case, based on the cytotoxicity of the THMs formed, the use of NH2Cl is recommended.
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Affiliation(s)
- Sebastien Allard
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University , GPO Box U1987, Perth Western Australia 6845, Australia
| | - Jace Tan
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University , GPO Box U1987, Perth Western Australia 6845, Australia
| | - Cynthia A Joll
- Curtin Water Quality Research Centre, Department of Chemistry, Curtin University , GPO Box U1987, Perth Western Australia 6845, Australia
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, ETH Zürich , 8600 Zürich, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale Lausanne (EPFL) , 1015 Lausanne, Switzerland
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Balmer J, Zulliger R, Roberti S, Enzmann V. Retinal Cell Death Caused by Sodium Iodate Involves Multiple Caspase-Dependent and Caspase-Independent Cell-Death Pathways. Int J Mol Sci 2015; 16:15086-103. [PMID: 26151844 PMCID: PMC4519888 DOI: 10.3390/ijms160715086] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/02/2015] [Accepted: 06/04/2015] [Indexed: 01/09/2023] Open
Abstract
Herein, we have investigated retinal cell-death pathways in response to the retina toxin sodium iodate (NaIO3) both in vivo and in vitro. C57/BL6 mice were treated with a single intravenous injection of NaIO3 (35 mg/kg). Morphological changes in the retina post NaIO3 injection in comparison to untreated controls were assessed using electron microscopy. Cell death was determined by TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining. The activation of caspases and calpain was measured using immunohistochemistry. Additionally, cytotoxicity and apoptosis in retinal pigment epithelial (RPE) cells, primary retinal cells, and the cone photoreceptor (PRC) cell line 661W were assessed in vitro after NaIO3 treatment using the ApoToxGlo™ assay. The 7-AAD/Annexin-V staining was performed and necrostatin (Nec-1) was administered to the NaIO3-treated cells to confirm the results. In vivo, degenerating RPE cells displayed a rounded shape and retracted microvilli, whereas PRCs featured apoptotic nuclei. Caspase and calpain activity was significantly upregulated in retinal sections and protein samples from NaIO3-treated animals. In vitro, NaIO3 induced necrosis in RPE cells and apoptosis in PRCs. Furthermore, Nec-1 significantly decreased NaIO3-induced RPE cell death, but had no rescue effect on treated PRCs. In summary, several different cell-death pathways are activated in retinal cells as a result of NaIO3.
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Affiliation(s)
- Jasmin Balmer
- Department of Ophthalmology, Inselspital, University of Bern, Bern 3010, Switzerland.
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
| | - Rahel Zulliger
- Department of Cell Biology, the University of Oklahoma Health Sciences Center, University of Oklahoma, Oklahoma City, OK 73104, USA.
| | - Stefano Roberti
- Department of Ophthalmology, Inselspital, University of Bern, Bern 3010, Switzerland.
| | - Volker Enzmann
- Department of Ophthalmology, Inselspital, University of Bern, Bern 3010, Switzerland.
- Department for Clinical Research, University of Bern, Bern 3010, Switzerland.
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Hariri S, Tam MC, Lee D, Hileeto D, Moayed AA, Bizheva K. Noninvasive imaging of the early effect of sodium iodate toxicity in a rat model of outer retina degeneration with spectral domain optical coherence tomography. J Biomed Opt 2013; 18:26017. [PMID: 23396538 DOI: 10.1117/1.jbo.18.2.026017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
An ultrahigh resolution spectral domain optical coherence tomography (SD-OCT) system is used to observe for the first time in vivo the early effect of sodium iodate (NaIO3) toxicity on retinal morphology. Retinal degeneration is induced in rats via tail vein injection of NaIO3 and structural changes in the outer retina are assessed longitudinally at baseline and 1, 2, 3, 6, 8, and 10 h, and 12 post drug administration with OCT, H&E histology, and IgG immunochemistry. Disruption of the structural integrity and changes in the optical reflectivity of the photoreceptor inner (IS) and outer segment (OS) layers are observed as early as 1 h post NaIO3 injection. A new layer is observed in the OCT tomograms to form between the retinal pigmented epithelium and the photoreceptors OS a few hours post NaIO3 injection. The dynamics and the low optical reflectivity of this layer, as well as cell swelling and disruption of the blood-retina barrier observed in the histological and immunohistochemistry cross-sections suggest that the layer corresponds to temporary fluid accumulation in the retina. Results from this study demonstrate the effectiveness of OCT technology for monitoring dynamic changes in the retinal morphology and provide better understanding of the early stages of outer retina degeneration induced by NaIO3 toxicity.
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Affiliation(s)
- Sepideh Hariri
- University of Waterloo, Department of Physics and Astronomy, Waterloo, Ontario, Canada
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Noel JM, Fernandez de Castro JP, DeMarco PJ, Franco LM, Wang W, Vukmanic EV, Peng X, Sandell JH, Scott PA, Kaplan HJ, McCall MA. Iodoacetic acid, but not sodium iodate, creates an inducible swine model of photoreceptor damage. Exp Eye Res 2012; 97:137-47. [PMID: 22251455 PMCID: PMC3323738 DOI: 10.1016/j.exer.2011.12.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 12/16/2011] [Accepted: 12/22/2011] [Indexed: 11/26/2022]
Abstract
Our purpose was to find a method to create a large animal model of inducible photoreceptor damage. To this end, we tested in domestic swine the efficacy of two chemical toxins, known to create photoreceptor damage in other species: Iodoacetic Acid (IAA) and Sodium Iodate (NaIO(3)). Intravenous (IV) administration of NaIO(3) up to 90 mg/kg had no effect on retinal function and 110 mg/kg was lethal. IV administration of IAA (5-20 mg/kg) produced concentration-dependent changes in visual function as measured by full-field and multi-focal electroretinograms (ffERG and mfERG), and 30 mg/kg IAA was lethal. The IAA-induced effects measured at two weeks were stable through eight weeks post-injection, the last time point investigated. IAA at 7.5, 10, and 12 mg/kg produce a concentration-dependent reduction in both ffERG b-wave and mfERG N1-P1 amplitudes compared to baseline at all post-injection times. Comparisons of dark- and light-adapted ffERG b-wave amplitudes show a more significant loss of rod relative to cone function. The fundus of swine treated with ≥10 mg/kg IAA was abnormal with thinner retinal vessels and pale optic discs, and we found no evidence of bone spicule formation. Histological evaluations show concentration-dependent outer retinal damage that correlates with functional changes. We conclude that NaIO(3,) is not an effective toxin in swine. In contrast, IAA can be used to create a rapidly inducible, selective, stable and concentration-dependent model of photoreceptor damage in swine retina. Because of these attributes this large animal model of controlled photoreceptor damage should be useful in the investigation of treatments to replace damaged photoreceptors.
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Affiliation(s)
- Jennifer M. Noel
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY
| | | | - Paul J. DeMarco
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
- Department of Psychological and Brain Sciences, University of Louisville, Louisville, KY
| | - Luisa M. Franco
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Wei Wang
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Eric V. Vukmanic
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Xiaoyan Peng
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Julie H. Sandell
- Department of Anatomy and Neurobiology, Boston University, Boston, MA
| | - Patrick A. Scott
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
- Department of Anatomy and Neurobiology, Boston University, Boston, MA
| | - Henry J. Kaplan
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
| | - Maureen A. McCall
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY
- Department of Psychological and Brain Sciences, University of Louisville, Louisville, KY
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Xu J, Liu XL, Yang XF, Guo HL, Zhao LN, Sun XF. Supplemental selenium alleviates the toxic effects of excessive iodine on thyroid. Biol Trace Elem Res 2011; 141:110-8. [PMID: 20517655 DOI: 10.1007/s12011-010-8728-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 05/04/2010] [Indexed: 10/19/2022]
Abstract
As excessive iodine intake is associated with a decrease of the activities of selenocysteine-containing enzymes, supplemental selenium was hypothesized to alleviate the toxic effects of excessive iodine. In order to verify this hypothesis, Balb/C mice were tested by giving tap water with or without potassium iodate and/or sodium selenite for 16 weeks, and the levels of iodine in urine and thyroid, the hepatic selenium level, the activities of glutathione peroxidase (GSHPx), type 1 deiodinase (D1), and thyroid peroxidase (TPO) were assayed. It had been observed in excessive iodine group that hepatic selenium, the activities of GSHPx, D1, and TPO decreased, while in the groups of 0.2 mg/L, 0.3 mg/L and 0.4 mg/L supplemental selenium, the urinary iodine increased significantly. Compared with the group of excessive iodine intake alone, supplemental selenium groups had higher activities of GSHPx, D1, and TPO. We could draw the conclusion that supplemental selenium could alleviate toxic effect of excessive iodine on thyroid. The optimal dosage of selenium ranges from 0.2 to 0.3 mg/L which can protect against thyroid hormone dysfunction induced by excessive iodine intake.
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Affiliation(s)
- Jian Xu
- Shenzhen Center for Chronic Disease Control, Shenzhen, 518020, People's Republic of China.
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Redfern WS, Storey S, Tse K, Hussain Q, Maung KP, Valentin JP, Ahmed G, Bigley A, Heathcote D, McKay JS. Evaluation of a convenient method of assessing rodent visual function in safety pharmacology studies: effects of sodium iodate on visual acuity and retinal morphology in albino and pigmented rats and mice. J Pharmacol Toxicol Methods 2010; 63:102-14. [PMID: 20619348 DOI: 10.1016/j.vascn.2010.06.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Revised: 06/04/2010] [Accepted: 06/29/2010] [Indexed: 11/13/2022]
Abstract
INTRODUCTION We have evaluated the ability of a semi-automated, optomotor reflex method to assess drug-induced visual dysfunction, in albino and pigmented rats and mice. METHODS Male Han Wistar (HW) and Long Evans (LE) rats and mice (CD-1 and C57BL/6) were tested in a chamber formed by 4 computer monitors displaying a rotating vertical grating, to elicit head-tracking movements. The highest visible grating frequency was taken as the threshold of visual acuity, in cycles per degree (c/d). Animals received an intravenous infusion of either sodium iodate (50mg/kg) or 0.9% w/v NaCl (aq). They were tested 2h later, then re-tested daily for a further 3 days. The time course of the effect was assessed in HW rats over a 6-week period, including electron microscopy, and immunohistochemical analysis of markers of injury and repair in the retina. RESULTS Baseline visual acuities for HW and LE rats were 0.355 ± 0.007 and 0.530 ± 0.004 c/d, respectively, and 0.296 ± 0.003 c/d and 0.370 ± 0.001 c/d for CD-1 and C57BL/6 mice, respectively (n=10 for each). In HW rats there was a dramatic loss of visual acuity 2h after administration of sodium iodate (0.021 ± 0.021 c/d; P<0.001). Less dramatic decreases in visual acuity were seen in LE rats and in the two mouse strains. In HW rats, visual acuity was restored after 4 weeks. This paralleled the histopathological recovery of the peripheral retina, whereas the central retina did not recover. DISCUSSION The method proved to be very convenient, and the stability of visual acuity in vehicle control rats over a 6-week period also demonstrated its suitability for inclusion in long-term toxicity studies. Both albino and pigmented mice and rats are suitable for assessment of retinotoxicity using this method, but albino rats are the most sensitive to sodium iodate.
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Affiliation(s)
- William S Redfern
- Safety Pharmacology Departmen, Safety Assessment UK, AstraZeneca R&D, Alderley Park, Cheshire SK10 4TG, United Kingdom.
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Ohtaka K, Machida S, Ohzeki T, Tanaka M, Kurosaka D, Masuda T, Ishii T. Protective Effect of Hepatocyte Growth Factor Against Degeneration of the Retinal Pigment Epithelium and Photoreceptor in Sodium Iodate–Injected Rats. Curr Eye Res 2009; 31:347-55. [PMID: 16603468 DOI: 10.1080/02713680600629797] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PURPOSE To investigate the possible protective effect of hepatocyte growth factor (HGF) against degeneration of photoreceptors and retinal pigment epithelium (RPE) in vivo. METHODS Sprague-Dawley (SD) rats received an intravitreal injection of HGF in the right eye. The left eye was injected with vehicle as a control. Two days after the intravitreal injections, rats were administered 40 mg/kg of sodium iodate (NaIO3) intravenously. Scotopic ERGs were elicited by different stimulus intensities with a maximum luminance of 0.84 log cds/m2. To evaluate RPE function, the azide response was evoked by intravenous injection of 0.1 mg sodium azide. These electrophysiological measurements were conducted on days 4, 7, 14, and 28 after the NaIO3 injections. After recording ERGs or azide response, animals were sacrificed for quantification of the histological change and immunohistochemical analysis using antibodies against RPE 65. RESULTS The threshold for the scotopic b-wave was significantly lower in HGF-treated eyes than in untreated control eyes (p < 0.005), and maximum b-wave amplitudes (Vbmax) were significantly larger in HGF-treated eyes (p < 0.05) across all experimental time points after NaIO3 injection. Azide response amplitudes were significantly larger in the HGF-treated eyes than in the untreated eyes (p < 0.05). The structure of the outer retina was preserved to a greater degree in the HGF-treated eyes than in the untreated eyes (p < 0.05). Immunohistochemical analysis demonstrated that irregular alignment of the outer nuclear layer was confined to the retinal area that was not stained with RPE 65. CONCLUSIONS Our results indicated that an intravitreal injection of HGF provided significant protection against degeneration of the photoreceptor and RPE induced by systemic administration of NaIO3. This suggests that HGF could be used as a therapeutic agent for degeneration of photoreceptors as well as RPE.
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Affiliation(s)
- Kouji Ohtaka
- Department of Ophthalmology, Iwate Medical University School of Medicine, Iwate, Japan
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Berkowitz BA, Roberts R, Luan H, Bissig D, Bui BV, Gradianu M, Calkins DJ, Vingrys AJ. Manganese-enhanced MRI studies of alterations of intraretinal ion demand in models of ocular injury. Invest Ophthalmol Vis Sci 2007; 48:3796-804. [PMID: 17652754 PMCID: PMC2041849 DOI: 10.1167/iovs.06-1278] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To provide proof-of-concept that the extent of intraretinal manganese uptake after systemic MnCl(2) injection, detected with manganese-enhanced MRI (MEMRI), assesses alterations in intraretinal ion demand in models of ocular insult. METHODS In Sprague-Dawley rats, retinal ion demand and thickness were measured from MEMRI data collected before, 4 hours after, or 1, 3, and 7 days after intraperitoneal injection of MnCl(2). Choroidal contribution or blood-retinal barrier permeability surface area product (BRB PS') was determined using MRI after Gd-DTPA injection. Ocular injury was evaluated 24 hours after intravitreal injection of phosphate-buffered saline (PBS, vehicle) or PBS + ouabain, or after intraperitoneal injection of sodium iodate. Manganese retinal toxicity was assessed by comparing full-field, white-flash electroretinographic (ERG) data obtained before and after systemic MnCl(2) administration. Rat choroidal thickness was measured from cross-sections prepared from paraformaldehyde-perfused adult rats. RESULTS Comparing pre- and post-Gd-DTPA images demonstrated minimal choroidal contribution to intraretinal analysis. Intraretinal signal intensity returned to baseline by 7 days after MnCl(2) injection. After ouabain injection, receptor and postreceptor uptake of manganese were subnormal (P < 0.05). After sodium iodate exposure, intraretinal manganese uptake was supernormal (P < 0.05) and did not increase with increasing BRB PS'. ERG data did not show any effect of MnCl(2) on photoreceptor a-wave and postreceptor b-wave relative to baseline at either observation time. CONCLUSIONS MEMRI measurements of uptake of systemically administered and nontoxic doses of manganese appear to be a powerful approach for measuring alteration in intraretinal ion demand in models of ocular injury.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan
- Department of Ophthalmology, Wayne State University, Detroit, Michigan
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan
| | - Hongmei Luan
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan
| | - David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan
| | - Bang V. Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Marius Gradianu
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan
| | - David J. Calkins
- Department of Ophthalmology and Visual Sciences, Vanderbilt University, Nashville, Tennessee
| | - Algis J. Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
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Siu TL, Morley JW. Influence of callosal transfer on visual cortical evoked response and the implication in the development of a visual prosthesis. Graefes Arch Clin Exp Ophthalmol 2007; 245:1797-803. [PMID: 17638003 DOI: 10.1007/s00417-007-0648-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 06/19/2007] [Accepted: 06/23/2007] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND The development of a visual prosthesis has been limited by an incomplete understanding of functional changes of the visual cortex accompanying deafferentation. In particular, the role of the corpus callosum in modulating these changes has not been fully evaluated. Recent experimental evidence suggests that through synaptic modulation, short-term (4-5 days) visual deafferentation can induce plastic changes in the visual cortex, leading to adaptive enhancement of residual visual input. We therefore investigated whether a compensatory rerouting of visual information can occur via the indirect transcallosal linkage after deafferentation and the influence of this interhemispheric communication on the visual evoked response of each hemisphere. METHODS In albino rabbits, misrouting of uncrossed optic fibres reduces ipsilateral input to a negligible degree. We thus took advantage of this congenital anomaly to model unilateral cortical and ocular deafferentation by eliminating visual input from one eye and recorded the visual evoked potential (VEP) from the intact eye. RESULTS In keeping with the chiasmal anomaly, no VEP was elicited from the hemisphere ipsilateral to the intact eye. This remained unchanged following unilateral visual deafferentation. The amplitude and latency of the VEP in the fellow hemisphere, however, were significantly decreased in the deafferented animals. CONCLUSION Our data suggest that callosal linkage does not contribute to visual evoked responses and this is not changed after short-term deafferentation. The decrease in amplitude and latency of evoked responses in the hemisphere ipsilateral to the treated eye, however, confirms the facilitatory role of callosal transfer. This observation highlights the importance of bicortical stimulation in the future design of a cortical visual prosthesis.
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Affiliation(s)
- Timothy L Siu
- Department of Neurosurgery, Prince of Wales Hospital, Barker Street, Randwick, NSW 2031, Australia.
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Harris JR, Brown GAJ, Jorgensen M, Kaushal S, Ellis EA, Grant MB, Scott EW. Bone marrow-derived cells home to and regenerate retinal pigment epithelium after injury. Invest Ophthalmol Vis Sci 2006; 47:2108-13. [PMID: 16639022 PMCID: PMC3759824 DOI: 10.1167/iovs.05-0928] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
PURPOSE To determine whether hematopoietic stem and progenitor cells (HSCs/HPCs) can home to and regenerate the retinal pigment epithelium (RPE) after induced injury. METHODS Enriched HSCs/HPCs from green fluorescent protein (gfp) transgenic mice were transplanted into irradiated recipient mice to track bone marrow-derived cells. Physical damage was induced by breaching Bruch's membrane and inducing vascular endothelial growth factor A (VEGFa) expression to promote neovascularization. RPE damage was also induced by sodium iodate injection (40 mg/kg) into wild-type or albino C57Bl/6 mice. Cell morphology, gfp expression, the presence of the Y chromosome, and the presence of melanosomes were used to determine whether the injured RPE was being repaired by the donor bone marrow. RESULTS Injury to the RPE recruits HSC/HPC-derived cells to incorporate into the RPE layer and differentiate into an RPE phenotype. A portion of the HSCs/HPCs adopt RPE morphology, express melanosomes, and integrate into the RPE without cell fusion. CONCLUSIONS HSCs/HPCs can migrate to the RPE layer after physical or chemical injury and regenerate a portion of the damaged cell layer.
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Affiliation(s)
- Jeffrey R. Harris
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
| | - Gary A. J. Brown
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
| | - Marda Jorgensen
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
| | - Shalesh Kaushal
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
| | - E. Ann Ellis
- Microscopy and Imaging Center, Texas A&M University, College Station, Texas
| | - Maria B. Grant
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
| | - Edward W. Scott
- Program in Stem Cell Biology, University of Florida, Gainesville, Florida
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Li Y, Reca RG, Atmaca-Sonmez P, Ratajczak MZ, Ildstad ST, Kaplan HJ, Enzmann V. Retinal pigment epithelium damage enhances expression of chemoattractants and migration of bone marrow-derived stem cells. Invest Ophthalmol Vis Sci 2006; 47:1646-52. [PMID: 16565405 DOI: 10.1167/iovs.05-1092] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To characterize chemoattractants expressed by the retinal pigment epithelium (RPE) after sodium iodate (NaIO3)-induced damage and to investigate whether ocular-committed stem cells preexist in the bone marrow (BM) and migrate in response to the chemoattractive signals expressed by the damaged RPE. METHODS C57/BL6 mice were treated with a single intravenous injection of NaIO3 (50 mg/kg) to create RPE damage. At different time points real-time RT-PCR, ELISA, and immunohistochemistry were used to identify chemoattractants secreted in the subretinal space. Conditioned medium from NaIO3-treated mouse RPE was used in an in vitro assay to assess chemotaxis of stem cell antigen-1 positive (Sca-1+) BM mononuclear cells (MNCs). The expression of early ocular markers (MITF, Pax-6, Six-3, Otx) in migrated cells and in MNCs isolated from granulocyte colony-stimulating factor (G-CSF) and Flt3 ligand (FL)-mobilized and nonmobilized peripheral blood (PB) was analyzed by real-time RT-PCR. RESULTS mRNA for stromal cell-derived factor-1 (SDF-1), C3, hepatocyte growth factor (HGF), and leukemia inhibitory factor (LIF) was significantly increased, and higher SDF-1 and C3 protein secretion from the RPE was found after NaIO3 treatment. A higher number of BMMNCs expressing early ocular markers migrated to conditioned medium from damaged retina. There was also increased expression of early ocular markers in PBMNCs after mobilization. CONCLUSIONS Damaged RPE secretes cytokines that have been shown to serve as chemoattractants for BM-derived stem cells (BMSCs). Retina-committed stem cells appear to reside in the BM and can be mobilized into the PB by G-CSF and FL. These stem cells may have the potential to serve as an endogenous source for tissue regeneration after RPE damage.
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Affiliation(s)
- Yang Li
- Department of Ophthalmology and Visual Sciences, the
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Poul JM, Huet S, Godard T, Sanders P. Lack of genotoxicity of potassium iodate in the alkaline comet assay and in the cytokinesis-block micronucleus test. Comparison to potassium bromate. Food Chem Toxicol 2004; 42:203-9. [PMID: 14667467 DOI: 10.1016/j.fct.2003.08.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Iodine could be added to the diet of human population in the form of iodide or iodate but iodate had not been adequately tested for genotoxicity and carcinogenicity. In the present study, genotoxic effects of potassium iodate were evaluated in vitro using the alkaline comet assay and the cytokinesis-block micronucleus assay on CHO cells and compared to halogenate salt analogues potassium bromate and chlorate and also to their respective reduced forms (potassium iodide, bromide and chloride). The results showed that the comet assay failed to detect the presence of DNA damage after a treatment of cells by potassium iodate for concentrations up to 10 mM. This absence of primary DNA damage was confirmed in the cytokinesis-block micronucleus assay. In the same way, results showed that potassium chlorate as well as potassium iodide, bromide and chloride did not induced DNA damage in the alkaline comet assay for doses up to 10 mM. By contrast, potassium bromate exposure led to an increase in both DNA damage and frequency of micronucleated cells. The repair of bromate-induced DNA damage was incomplete 24 h after the end of treatment. These results seem to indicate that potassium bromate would induce DNA damage by several mechanisms besides oxidative stress.
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Affiliation(s)
- J M Poul
- AFSSA, Laboratoire d'Etudes et de Recherches sur les Médicaments Vétérinaires et les Désinfectants, Unité de Toxicologie Alimentaire, BP 90203, 35302 Cedex Fougères, France.
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23
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Abstract
PURPOSE To identify the retinal cells that determine the a-wave latency of rats. METHODS Electroretinograms (ERGs) were recorded from the rod-dominated (0.85% cones) retinas of Long-Evans rats following an intravitreal injection of 1 microL of 40 mM 2-amino-4-phosphonobutyric acid to block the activity of the ON pathway of the second order retinal neurons. ERGs were also recorded following an intraperitoneal injection of sodium iodate to destroy the retinal pigment epithelial (RPE) cells. Damage to a large area of the retina was produced by constant light exposure, and focal damage to the retina was induced by argon laser photocoagulation. The effects of age and anesthesia level on the a-wave latency were also determined. RESULTS Blocking the activity of the ON pathway of the second order retinal neurons did not alter the a-wave latency, and destroying the RPE cells also did not alter the a-wave latency. Damage to a large area of the retina resulted in prolonging the latency but focal retinal damage did not alter the a-wave latency. The a-wave latency was longer in young rat pups but was adult-like by 18 days. The level of anesthesia had no effect on the latency except at very deep stages. CONCLUSIONS The a-wave latency is determined solely by the activity of the photoreceptors. A prolonged latency would indicate that the photoreceptors are damaged over a large area of the retina.
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Affiliation(s)
- Hui Qiu
- Department of Ophthalmology, Hamamatsu University Medical School, Hamamatsu, Japan
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24
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Ueno H, Oishi K, Sayato Y, Nakamuro K. Oxidative cell damage in Kat-sod assay of oxyhalides as inorganic disinfection by-products and their occurrence by ozonation. Arch Environ Contam Toxicol 2000; 38:1-6. [PMID: 10556365 DOI: 10.1007/s002449910001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Nine oxyhalides as possible inorganic disinfection by-products were tested for oxidative cell damage by Kat-sod assay with E. coli mutant strains deficient in the active oxygen-scavenging enzymes. Chlorine dioxide, chlorite, and iodate were highly cytotoxic, whereas in the presence of cysteine, bromate (BrO3-) and metaperiodate (IO4-) showed more growth inhibition toward the superoxide dismutase-deficient strains than the wild strain. BrO3- also showed oxidative mutagenicity with cysteine or glutathione ethyl ester in S. typhimurium TA 100. To identify oxyhalides formed by ozonation of raw water containing sea water, the occurrence of ozonation by-products of bromide and iodide was investigated. The results indicate that BrO3- is toxicologically one of the most remarkable oxyhalides detectable in drinking water because IO4- was not detected in the ozonated solution of iodide, and the ozonation condition to lower BrO3- is to keep it neutral in the presence of ammonium ion.
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Affiliation(s)
- H Ueno
- Department of Biological Sciences, 1845 N. Fairmount, Wichita State University, Wichita, Kansas 67260-0026, USA
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25
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Abstract
ERGs and the azide responses were recorded from mice before and periodically up to 6 weeks after retinal pigment epithelium (RPE) damage by iodate injection to follow the recovery of retinal pigment epithelium and retinal function. At 14 days postinjection, there was a partial recovery of the maximal b-wave amplitude and the azide response but no further recovery was found after 14 days. The retinal sensitivity showed a slow recovery, and at 6 weeks postinjection did not differ from the pre-iodate sensitivity. These findings correlated with histological observations. We concluded that the recovery in ERGs resulted from RPE recovery and the large patchy area of recovered retina functioned normally.
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Affiliation(s)
- A Mizota
- Department of Ophthalmology, Chiba University School of Medicine, Japan
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26
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Sugimoto S, Imawaka M, Kurata K, Kanamaru K, Ito T, Sasaki S, Ando T, Saijo T, Sato S. [A procedure for recording electroretinogram (ERG) and effect of sodium iodate on ERG in mice]. J Toxicol Sci 1996; 21 Suppl 1:15-32. [PMID: 8709159 DOI: 10.2131/jts.21.supplementi_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A procedure for recording the electroretinogram (ERG) in mice with a coiled stainless steel-type electrode was developed in order to examine retinal toxicity. Mice received a single i.v. of sodium iodate (SI), a retinotoxic compound, via the tail vein at a dose of 12.5, 25, or 50 mg/kg, and the ERG was recorded periodically for 28 days after dosing. In addition, the retina was examined histopathologically on day 30 after dosing. 1. The mice were anesthetized with mixed anesthetics of urethane, xylazine and ketamine after 30 to 60 min of dark-adaptation. Sixteen responses to repetitive 1.2 J light stimuli at a frequency of 0.2 or 0.1 Hz were averaged by a microcomputer. Body temperature of the mice was kept constant at 37 to 38 degrees C using a thermostatically controlled heating mat. Under these conditions, stable ERG a-wave, b-wave, oscillatory potentials and c-wave could be recorded for 28 days. 2. SI at doses of 25 mg/kg or more caused depression of the amplitudes of the oscillatory potentials, and enhancement of the a- and b-wave amplitudes, while the c-wave was already extinguished on day 1 after dosing. Following these changes, the amplitudes of the a- and b-wave decreased from day 3 or 7 after dosing. These changes did not recover until day 28 after dosing. 3. Upon histopathologic examination of the retina, folding of the outer nuclear layer, disarrangement of the rods and cones, decrease of the visual cells and swelling and decrease of the pigment epithelial cells were observed with SI at 25 mg/kg or more. 4. Using this recording technique, it was confirmed that a stable ERG was recorded repeatedly for 28 days in mice, and the effects of SI on the ERG could be detected. Histopathologic findings in the retina revealed the abnormal portions were correlated well with the changes in the ERG. These results indicate that the ERG recording procedure developed in this study is useful for evaluating retinal toxicity in mice.
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Affiliation(s)
- S Sugimoto
- Drug Safety Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan
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27
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Takeuchi A, Kricorian G, Marmor MF. Albumin movement out of the subretinal space after experimental retinal detachment. Invest Ophthalmol Vis Sci 1995; 36:1298-305. [PMID: 7775107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE The subretinal fluid of serous retinal detachments contains protein, but little is known about its origin and fate. The authors designed experiments to study the rate and route of albumin movement out of the subretinal space. METHODS Experimental retinal detachments were made in Dutch rabbits by injecting Hanks' balanced salt solution containing serum levels (approximately 30 mg/ml) of fluorescein isothiocyanate (FITC) albumin into the subretinal space through a micropipette. Subretinal, vitreous, and serum fluid samples were withdrawn 0 to 4 hours later through a similar micropipette and were analyzed for osmolality, FITC albumin content (by fluorophotometry) and FITC+native albumin content (by gel electrophoresis). Sodium iodate was injected intravenously in some rabbits to damage the retinal pigment epithelium (RPE). RESULTS Albumin injected into the subretinal fluid diffused steadily into the vitreous, and its concentration decreased by approximately 5% per hour. This rate was unaffected by RPE damage. Albumin did not move into the bloodstream unless the RPE was damaged with sodium iodate, and then it crossed the RPE at approximately 25% of the rate at which it moved into the vitreous. Subretinal fluid osmolality remained within the range of 293 to 294 mOsm/kg despite protein movement and the continual absorption of fluid from the detachments. CONCLUSIONS These results show that albumin in the subretinal space diffuses readily into the vitreous, and subretinal osmolality changes are rapidly equilibrated with the vitreous. Albumin does not cross normal RPE, and it crosses iodate-damaged RPE more slowly than it crosses retina. Thus, there must be a constant supply of albumin if high subretinal concentrations are to be sustained in clinical serous detachments.
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Affiliation(s)
- A Takeuchi
- Department of Ophthalmology, Stanford University School of Medicine, California, USA
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28
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Abstract
Methanol is an ocular toxicant which causes visual dysfunction often leading to blindness after acute exposure. The physiological and biochemical changes responsible for this toxicity are poorly understood. Previously, we reported that the folate-reduced (FR) rat is an animal model which mimics the characteristic human methanol toxicities. The present study examines the hypothesis that depletion of ATP after methanol administration is the initiating event in methanol-induced retinal toxicity. ATP is reduced in retinae of methanol-treated FR rats to the same extent as is seen in retinae of FR and folate-sufficient (FS) rats treated with the Müller cell (retinal glial cell) toxin alpha-aminoadipic acid. Changes in the electroretinogram and the response of Müller cells to a potassium stimulus are also similarly eliminated in methanol-treated FR rats and alpha-aminoadipic acid-treated FR and FS rats. These results suggest that the Müller cell may be the initial target in methanol-induced visual system toxicity.
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Affiliation(s)
- C D Garner
- Department of Automotive Safety and Health Research, General Motors Corporation, Warren, Michigan 48090-9055
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29
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Sugimoto S, Imawaka M, Ozaki H, Ito T, Ando T, Sato S. [A procedure for recording electroretinogram (ERG) with a contact lens-type electrode, and effect of sodium iodate on ERG in rats]. J Toxicol Sci 1994; 19 Suppl 3:531-42. [PMID: 7837305 DOI: 10.2131/jts.19.supplementiii_531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A procedure for recording the electroretinogram (ERG) in rats with a contact lens-type electrode was developed in order to examine visual toxicity overtime. Rats received a single intravenous injection of sodium iodate (SI), a retinotoxic compound, via the tail vein at a dose of 12.5, 20, 25 or 50 mg/kg, and the ERG was recorded for 10 days after dosing. Histopathologic examination of the retinas was then conducted. 1. The rats were anesthetized with ketamine hydrochloride (50 mg/kg, i.m.) after 90 to 120 min of dark-adaptation. Thirty-two responses to repetitive 1.2 joule light stimuli at 0.5 Hz interstimulus intervals were averaged by a microcomputer. Under these conditions, stable ERG a-wave, b-wave and oscillatory potentials could be recorded for 10 days. 2. At 12.5 mg/kg of SI, no treatment-related abnormalities were observed on the ERG. Doses of 20 mg/kg or more of SI caused depression of the amplitudes of the ERG a-wave and oscillatory potentials 2 hrs or 1 day after dosing. Following these changes, the amplitude of the ERG b-wave decreased 1 or 2 days after dosing. 3. Upon histopathologic examination of the retina, folding of the outer nuclear layer, disarrangement of the rods and cones and swelling and decrease of the pigment epithelial cells were observed at 20 mg/kg or more. The severity of the retinal lesions correlated well with the changes in the ERG. 4. Using this recording technique, it was confirmed that a stable ERG could be recorded repeatedly in rats, and the effects of SI on the ERG could be detected. Furthermore, histopathologic examination revealed that the severity of the retinal lesions correlated well with the changes in the ERG. These results indicate that the ERG recording technique employed in this study is useful for evaluating retinal toxicity in rats.
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Affiliation(s)
- S Sugimoto
- Drug Safety Research Laboratories, Takeda Chemical Industries, Ltd., Osaka, Japan
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30
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Adachi-Usami E, Mizota A, Ikeda H, Hanawa T, Kimura T. Transient increase of b-wave in the mouse retina after sodium iodate injection. Invest Ophthalmol Vis Sci 1992; 33:3109-13. [PMID: 1399414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Twenty C57 black mice received an injection of 40 mg/kg of sodium iodate through the caudal vein. The electroretinograms (ERGs) were recorded before and after injection. Flash stimuli with the maximum illuminance, 30,000 lux, were given at increasing levels of illuminance in 0.6 log U steps for 13 levels of intensity. The a- and b-wave amplitudes increased linearly with increased stimulus intensity for approximately 5.0 log U before being saturated. Twenty four hours after injection, the intensity-amplitude curve shifted toward the higher intensity region. It was calculated that the sensitivity loss of the b-wave after injection was 2.0 log U, although the maximum amplitude was larger and the peak latency was delayed. The same results were seen less obviously in the ERGs 48 hr after injection. After 96 hr, both waves were greatly attenuated and even abolished. At the time the increased ERGs were recorded, the histopathologic findings exhibited severe damage of the retina in the pigment epithelium and in the outer layer.
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Affiliation(s)
- E Adachi-Usami
- Department of Ophthalmology, Chiba University School of Medicine, Japan
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31
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Trier K, Olsen EB, Prause JU. Biochemical changes in rabbit sclera following destruction of pigment epithelium. Acta Ophthalmol 1991; 69:645-8. [PMID: 1776420 DOI: 10.1111/j.1755-3768.1991.tb04854.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The long-term effect of destruction of the pigment epithelium by sodium iodate on the biochemistry of rabbit sclera was studied in one group with intravenous injection of sodium iodate, and in a second group with injection of sodium iodate into the right eye. Intravenous treatment produced a non-significant increase in the uronic acid concentration. In the second group the untreated fellow eye was microscopically intact, but was shown (as the treated eye) to alter the concentration of uronic acid in different parts of the sclera. All eyes from treated animals exhibited changes in the relative content of the various glycosaminoglycans and in the content of hydroxyproline, hydroxylysine and proline. This work indicates that the pigment epithelium may play a key role in the control mechanism of the scleral connective tissue, and this again has major implications in terms of a possible medical treatment of axial myopia.
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Affiliation(s)
- K Trier
- Department of Dermatology, Rigshospitalet, Copenhagen, Denmark
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32
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Abstract
Intravenous sodium iodate damages the retinal pigment epithelium, causing immediate loss of the electroretinogram c-wave and eventual pigmentary retinopathy. L-cystein, an agent that enhances the c-wave, has been reported to prevent the late development of pigmentary degeneration. We found in rabbits that L-cystein given 30 min before, or simultaneously with (but not 30 min after) sodium iodate also blocks the loss of the c-wave. This result occurred at doses of L-cystein lower than those needed to produce enhancement of the c-wave, suggesting that these two actions of L-cystein may be independent. The iodate-blocking action of L-cystein may depend on chemical interaction.
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Affiliation(s)
- M Heike
- Department of Ophthamology, Stanford University School of Medicine, California
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33
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Ogata N, Kanai K, Ohkuma H, Uyama M. [Pathologic response of the regenerated retinal pigment epithelium (RPE)--affected by sodium iodate (NaIO3)]. Nippon Ganka Gakkai Zasshi 1989; 93:466-74. [PMID: 2801350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Phagocytosis, proliferation and metaplasia to fibroblast-like cells in the regenerated retinal pigment epithelial cell (RPE) were examined after damage caused by administration of sodium iodate. The solution of sodium iodate (40 mg/kg) was given in a single intravenous injection in rats. Three days after injection, RPE showed marked necrotic damage, but in 2 weeks flat regenerated RPE with short microvilli and no basal infolding were seen on Bruch's membrane. Polystyrene particles were then injected into the subretinal space. The rats were sacrificed 6 hours to 4 days after injection of the particles. The regenerated RPE showed phagocytosis within 6 hours. After 48 hours, they showed multilayer proliferation. After 4 days RPE transformed to spindle-shaped fibroblast-like cells. However proliferation and metaplasia of RPE markedly decreased. The results showed significant decrease in the function of regenerated RPE-cells as a result of their damage.
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34
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Ogata N, Kanai K, Ohkuma H, Uyama M. [Pathologic response of the weak damaged retinal pigment epithelium (RPE)--affected by sodium iodate (NaIO3)]. Nippon Ganka Gakkai Zasshi 1989; 93:439-48. [PMID: 2801347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We examined the cellular responses of the retinal pigment epithelium (RPE) damaged by sodium iodate. RPE was damaged by intravenous administration of sodium iodate, 10mg per kg body weight, in rats. This dose of the agent damaged RPE weakly. Twenty-four hours after the administration of sodium iodate, polystyrene particles were injected into the subretinal space trans-sclerally. Rats were sacrificed at 6 hours to 4 days after injection of particles. Twenty four hours after injection of sodium iodate, RPE were weakly damaged. The cell organelles were swollen and ruptured, but cell structures were not destroyed. Then particles were injected into the subretinal space, RPE did not phagocytize the particles until 24 hours after the injection of particles. After 48 hours, RPE showed proliferation. After 4 days, RPE formed thick multilayers in the subretinal space and transformed to spindle shapes, and RPE underwent metaplasia to fibroblast-like cells. However proliferation of RPE was not marked. RPE cells weakly damaged by sodium iodate showed delay in phagocytosis of the particles and decrease in proliferation and metaplasia to fibroblast-like cells.
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35
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Chou A, Takase M. [A electrophysiological method for evaluation of the retinal toxicity of drug]. Nippon Ganka Gakkai Zasshi 1984; 88:1350-6. [PMID: 6528835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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36
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Sato S, Sugimoto S, Chiba S. [Effects of sodium iodate, iodoacetic acid and ethambutol on electroretinogram and visual evoked potential in rats]. J Toxicol Sci 1984; 9:389-99. [PMID: 6527394 DOI: 10.2131/jts.9.389] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The effects of sodium iodate (SI), iodoacetic acid (IAA) and ethambutol (EB) on the electroretinogram (ERG) and the visual evoked potential (VEP) were examined in unrestrained rats. A single intravenous dose of SI at 25 mg/kg caused depression of amplitudes of the ERG a-wave and oscillatory potentials 24 hrs after dosing. Following these changes, the amplitude of the ERG b-wave decreased. The depression of the VEP was observed in parallel with the depression in amplitude of the ERG. A single intravenous dose of IAA, even at a dose of 60 mg/kg which induced death of the rats, did not cause any significant abnormality in the ERG and VEP. Repeated subcutaneous dose of EB at 500 mg/kg/day depressed the amplitude of the P1-N1 wave and prolonged the peak latency of the P1 and N1 waves of the VEP without affecting the ERG after administration for 5 to 6 weeks. These abnormalities of the VEP appeared almost in parallel with ataxic gait. Neither gross behavioral changes suggesting visual disturbances nor abnormal ocular fundus was revealed in any rat receiving SI or EB even when marked depression of the ERG and/or VEP was observed. These results indicate that SI damages retinal function and EB does the conduction pathways from the retina to the visual cortex. In addition, the simultaneous recordings of both the ERG and VEP in unrestrained rats were found to be useful for evaluating the visual toxicity, and to furnish useful information on the site of toxic action of drugs.
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37
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Korte GE, Reppucci V, Henkind P. RPE destruction causes choriocapillary atrophy. Invest Ophthalmol Vis Sci 1984; 25:1135-45. [PMID: 6480292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The authors have obtained evidence that destruction of the retinal pigment epithelium (RPE) causes choriocapillaris (CC) atrophy. The observations led us to hypothesize that the RPE modulates CC structure and function. Rabbits received injections of sodium iodate, which selectively destroyed the RPE. The authors killed the rabbits at various times after iodate and examined the RPE and CC by fluorescein angiography, fundus photography, and light and electron microscopy. Fluorescein angiography and fundus photography revealed a pattern of retinopathy similar to that described by other investigators, eg, blood-retinal barrier breakdown and the patchy nature of the RPE/CC degeneration. One week after injection of iodate, the RPE transformed into a mixture of flattened, depigmented cells and plump, highly pigmented ones lying along Bruch's membrane. The CC appeared normal by light microscopy, but electron microscopy revealed changes indicating CC atrophy: degenerating endothelial cells (EC), EC that appeared normal but had reduced numbers of fenestrae, and pericapillary basal laminae that looped away from the endothelium, as if the latter had shrunk. One month after iodate, patches of Bruch's membrane were devoid of RPE, which was replaced by scar tissue. The CC was markedly atrophic over these patches, having reduced numbers of profiles and smaller lumina in those which remained. The CC appeared normal over areas where RPE remained. Eleven weeks after iodate, the light microscopic picture parallelled that seen 1 month after injection, but the patchy RPE degeneration was more extensive. By electron microscopy, the CC profiles over areas devoid of RPE showed severe atrophy. Degenerating EC were more numerous. EC adjacent to areas of RPE loss had few or no fenestrae. Here, capillaries were encased in dense, collagenous, connective tissue, unlike the CC of normal rabbits. These changes were not seen where the RPE still covered Bruch's membrane. These observations suggest that RPE modulates CC structure and function. The authors propose that a diffusible vascular modulating factor produced by RPE cells does this.
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38
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Jonadet M, Chopineau J, Bastide P. [Optotoxic effects of sodium iodate on several enzymatic activities of the retina (glycolysis, Krebs cycle, pentose cycle)]. Ann Pharm Fr 1982; 40:281-9. [PMID: 7181424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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39
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Ringvold A, Olsen EG, Flage T. Transient breakdown of the retinal pigment epithelium diffusion barrier after sodium iodate: a fluorescein angiographic and morphological study in the rabbit. Exp Eye Res 1981; 33:361-9. [PMID: 7297617 DOI: 10.1016/s0014-4835(81)80088-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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40
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Gonsette RE. [Contrast media in use in myelography and ventriculography: current status and future prospects]. Radiol Med 1980; 66:195-202. [PMID: 6256823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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41
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Menna F. Therapeutic effects in ocular lesions obtained by systematic and topical administration of an activator of the oxygen metabolism. Ophthalmologica 1980; 180 Suppl 1:1-50. [PMID: 7231877 DOI: 10.1159/000309080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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42
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Abstract
Accumulation of iodate in eye tissues and fluids as a possible explanation of the retinotoxic effect of iodate has been studied by intravenous injection of NaIO3(30 mg/kg), 125IO-3 and 131I- in rabbits. 125IO-3 was determined in fluids and tissue extracts by precipitation with BaCl2 after addition of KIO3. 125IO-3 was rapidly broken down in blood (T 1/2 = 14 min.). 125IO-3 was not present in aqueous humour, vitreous or extracts from retina, choroid + pigmentary epithelium or liver. Concentrations of 125I were comparable in blood, choroid + pigmentary epithelium and liver tissue while in vitreous and aqueous humour low concentrations of 125I were found which, however, increased gradually during 5 hrs after injection to reach levels comparable with blood levels of 125I. Retina had a low concentration of 125I. The ratio 125I/131I (R) in blood decreases during the first 60 min. after injection followed by a slow rise. R in retina, choroid + pigmentary epithelium and liver was the same as in blood at the same time after injection. During the first 80 min. after injection R was higher in vitreous than in blood while it was lower in aqueous humour than in blood. At longer times after injection R was identical in the three fluids. The investigation has been supplemented with whole body scintigraphy of rabbits injected with NaIO3(30 mg/kg) and 131IO-3 or 131I-. The reduction kinetics of IO-3 to I- by some body fluids, tissues, cystein and glutathione was also studied. It is concluded that the retinotoxic effect of iodate is not due to accumulation of IO-3 in eye tissues, but more likely to damage to biochemical mechanisms involved in the reduction of IO-3 to I-.
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43
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Peyman GA, Vlchek JK, Seth NV. Chorioretinal diffusion processes following pigment epithelial degeneration. Invest Ophthalmol 1975; 14:58-62. [PMID: 1110139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We studied the effect of sodium iodate-induced pigment epithelial degeneration on chorioretinal diffusion processes. Rabbits received two intravenous injections of sodium iodate at the retinotoxic dose of 22.5 mg. per kilogram over a six- to eight-hour period. Combined horseradish peroxidase tracing technique and electron microscopy were used to compare diffusion processes over a five-week period. Ultrastructural examination of retina twenty-four hours after iodate administration revealed pigment epithelial degeneration, accompanied by disruption of junctional complexes (zonulae occludentes). Peroxidase molecules were found in areas of greater cytoplasmic degeneration and in intercellular spaces up to the level of the external limiting membrane. Ultrastructural observations at later stages revealed similar findings except in the case of Muller cells, 20 per cent of which showed cytoplasmic degeneration and peroxidase uptake. The diffusion barrier was not re-established as the replacement cells did not rebuild zonulae occludentes.
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44
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45
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Siegel SM, Smith CW. A note on the biological activity of the noble gas compound xenon trioxide. Space Life Sci 1972; 3:260-4. [PMID: 5038192 DOI: 10.1007/bf00928171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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