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Berkowitz BA, Paruchuri A, Stanek J, Podolsky RH, Childers KL, Roberts R. Acetazolamide Challenge Changes Outer Retina Bioenergy-Linked and Anatomical OCT Biomarkers Depending on Mouse Strain. Invest Ophthalmol Vis Sci 2024; 65:21. [PMID: 38488413 PMCID: PMC10946704 DOI: 10.1167/iovs.65.3.21] [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: 10/29/2023] [Accepted: 02/27/2024] [Indexed: 03/19/2024] Open
Abstract
Purpose The purpose of this study was to test the hypothesis that optical coherence tomography (OCT) bioenergy-linked and anatomical biomarkers are responsive to an acetazolamide (ACZ) provocation. Methods C57BL/6J mice (B6J, a strain with relatively inefficient mitochondria) and 129S6/ev mice (S6, a strain with relatively efficient mitochondria) were given a single IP injection of ACZ (carbonic anhydrase inhibitor) or vehicle. In each mouse, the Mitochondrial Configuration within Photoreceptors based on the profile shape Aspect Ratio (MCP/AR) index was determined from the hyper-reflective band immediately posterior to the external limiting membrane (ELM). In addition, we tested for ACZ-induced acidification by measuring contraction of the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness; the hyporeflective band (HB) signal intensity at the photoreceptor tips was also examined. Finally, the nuclear layer thickness was measured. Results In response to ACZ, MCP/AR was greater-than-vehicle in B6J mice and lower-than-vehicle in S6 mice. ACZ-treated B6J and S6 mice both showed ELM-RPE contraction compared to vehicle-treated mice, consistent with dehydration in response to subretinal space acidification. The HB intensity at the photoreceptor tips and the outer nuclear layer thickness (B6J and S6), as well as the inner nuclear layer thickness of B6J mice, were all lower than vehicle following ACZ. Conclusions Photoreceptor respiratory efficacy can be evaluated in vivo based on distinct rod mitochondria responses to subretinal space acidification measured with OCT biomarkers and an ACZ challenge, supporting and extending our previous findings measured with light-dark conditions.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H. Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Farias-Jofre M, Romero R, Galaz J, Xu Y, Miller D, Garcia-Flores V, Arenas-Hernandez M, Winters AD, Berkowitz BA, Podolsky RH, Shen Y, Kanninen T, Panaitescu B, Glazier CR, Pique-Regi R, Theis KR, Gomez-Lopez N. Blockade of IL-6R prevents preterm birth and adverse neonatal outcomes. EBioMedicine 2023; 98:104865. [PMID: 37944273 PMCID: PMC10665693 DOI: 10.1016/j.ebiom.2023.104865] [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: 07/07/2023] [Revised: 10/11/2023] [Accepted: 10/19/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Preterm birth preceded by spontaneous preterm labour often occurs in the clinical setting of sterile intra-amniotic inflammation (SIAI), a condition that currently lacks treatment. METHODS Proteomic and scRNA-seq human data were analysed to evaluate the role of IL-6 and IL-1α in SIAI. A C57BL/6 murine model of SIAI-induced preterm birth was developed by the ultrasound-guided intra-amniotic injection of IL-1α. The blockade of IL-6R by using an aIL-6R was tested as prenatal treatment for preterm birth and adverse neonatal outcomes. QUEST-MRI evaluated brain oxidative stress in utero. Targeted transcriptomic profiling assessed maternal, foetal, and neonatal inflammation. Neonatal biometrics and neurodevelopment were tested. The neonatal gut immune-microbiome was evaluated using metagenomic sequencing and immunophenotyping. FINDINGS IL-6 plays a critical role in the human intra-amniotic inflammatory response, which is associated with elevated concentrations of the alarmin IL-1α. Intra-amniotic injection of IL-1α resembles SIAI, inducing preterm birth (7% vs. 50%, p = 0.03, Fisher's exact test) and neonatal mortality (18% vs. 56%, p = 0.02, Mann-Whitney U-test). QUEST-MRI revealed no foetal brain oxidative stress upon in utero IL-1α exposure (p > 0.05, mixed linear model). Prenatal treatment with aIL-6R abrogated IL-1α-induced preterm birth (50% vs. 7%, p = 0.03, Fisher's exact test) by dampening inflammatory processes associated with the common pathway of labour. Importantly, aIL-6R reduces neonatal mortality (56% vs. 22%, p = 0.03, Mann-Whitney U-test) by crossing from the mother to the amniotic cavity, dampening foetal organ inflammation and improving growth. Beneficial effects of prenatal IL-6R blockade carried over to neonatal life, improving survival, growth, neurodevelopment, and gut immune homeostasis. INTERPRETATION IL-6R blockade can serve as a strategy to treat SIAI, preventing preterm birth and adverse neonatal outcomes. FUNDING NICHD/NIH/DHHS, Contract HHSN275201300006C. WSU Perinatal Initiative in Maternal, Perinatal and Child Health.
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Affiliation(s)
- Marcelo Farias-Jofre
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Division of Obstetrics and Gynecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Roberto Romero
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI, USA; Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA.
| | - Jose Galaz
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Division of Obstetrics and Gynecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Catolica de Chile, Santiago, Chile
| | - Yi Xu
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Derek Miller
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA
| | - Valeria Garcia-Flores
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA
| | - Marcia Arenas-Hernandez
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Andrew D Winters
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MO, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine; Detroit, MI, USA
| | - Robert H Podolsky
- Division of Biostatistics and Design Methodology, Center for Translational Research, Children's National Hospital, Silver Spring, MD, USA
| | - Yimin Shen
- Department of Radiology, School of Medicine, Wayne State University School of Medicine, Detroit, MI, USA
| | - Tomi Kanninen
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Bogdan Panaitescu
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Catherine R Glazier
- UCD School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Roger Pique-Regi
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kevin R Theis
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MO, USA
| | - Nardhy Gomez-Lopez
- Pregnancy Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, MD, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO, USA; Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MO, USA; Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA; Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
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Goodman C, Podolsky RH, Childers KL, Roberts R, Katz R, Waseem R, Paruchuri A, Stanek J, Berkowitz BA. Do multiple physiological OCT biomarkers indicate age-related decline in rod mitochondrial function in C57BL/6J mice? Front Neurosci 2023; 17:1280453. [PMID: 38046657 PMCID: PMC10693340 DOI: 10.3389/fnins.2023.1280453] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 10/31/2023] [Indexed: 12/05/2023] Open
Abstract
Purpose To test the hypothesis that rod photoreceptor mitochondria function in vivo progressively declines over time. Methods 2, 12, and 24 month-old dark- and light-adapted C57BL/6J (B6J) mice were examined by OCT. We measured (i) an index of mitochondrial configuration within photoreceptors measured from the profile shape aspect ratio (MCP/AR) of the hyperreflective band posterior to the external limiting membrane (ELM), (ii) a proxy for energy-dependent pH-triggered water removal, the thickness of the ELM-retinal pigment epithelium (ELM-RPE), and its correlate (iii) the hyporeflective band (HB) signal intensity at the photoreceptor tips. Visual performance was assessed by optokinetic tracking. Results In 2 and 24 month-old mice, MCP/AR in both inferior and superior retina was smaller in light than in dark; no dark-light differences were noted in 12 month-old mice. Dark-adapted inferior and superior, and light-adapted superior, ELM-RPE thickness increased with age. The dark-light difference in ELM-RPE thickness remained constant across all ages. All ages showed a decreased HB signal intensity magnitude in dark relative to light. In 12 month-old mice, the dark-light difference in HB magnitude was greater than in younger and older mice. Anatomically, outer nuclear layer thickness decreased with age. Visual performance indices were reduced at 24 month-old compared to 2 month-old mice. Conclusion While the working hypothesis was not supported herein, the results raise the possibility of a mid-life adaptation in rod mitochondrial function during healthy aging in B6J mice based on OCT biomarkers, a plasticity that occurred prior to declines in visual performance.
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Affiliation(s)
- Cole Goodman
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Robert H. Podolsky
- Biostatistics and Study Methodology, Children’s National Hospital, Silver Spring, MD, United States
| | | | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Ryan Katz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
| | - Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States
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4
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Berkowitz BA, Podolsky RH, Childers KL, Roberts R, Waseem R. Multiple Bioenergy-Linked OCT Biomarkers Suggest Greater-Than-Normal Rod Mitochondria Activity Early in Experimental Alzheimer's Disease. Invest Ophthalmol Vis Sci 2023; 64:12. [PMID: 36867132 PMCID: PMC9988708 DOI: 10.1167/iovs.64.3.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Purpose In Alzheimer's disease, central brain neurons show evidence for early hyperactivity. It is unclear if this occurs in the retina, another disease target. Here, we tested for imaging biomarker manifestation of prodromal hyperactivity in rod mitochondria in vivo in experimental Alzheimer's disease. Methods Light- and dark-adapted 4-month-old 5xFAD and wild-type (WT) mice, both on a C57BL/6J background, were studied with optical coherence tomography (OCT). We measured the reflectivity profile shape of the inner segment ellipsoid zone (EZ) as a proxy for mitochondria distribution. Two additional indices responsive to mitochondria activity were also measured: the thickness of the external limiting membrane-retinal pigment epithelium (ELM-RPE) region and the signal magnitude of a hyporeflective band (HB) between photoreceptor tips and apical RPE. Retinal laminar thickness and visual performance were evaluated. Results In response to low energy demand (light), WT mice showed the expected elongation in EZ reflectivity profile shape, relatively thicker ELM-RPE, and greater HB signal. Under high energy demand (dark), the EZ reflectivity profile shape was rounder, the ELM-RPE was thinner, and the HB was reduced. These OCT biomarker patterns for light-adapted 5xFAD mice did not match those of light-adapted WT mice but rather that of dark-adapted WT mice. Dark-adapted 5xFAD and WT mice showed the same biomarker pattern. The 5xFAD mice exhibited modest nuclear layer thinning and lower-than-normal contrast sensitivity. Conclusions Results from three OCT bioenergy biomarkers raise the novel possibility of early rod hyperactivity in vivo in a common Alzheimer's disease model.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen L Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Berkowitz BA, Podolsky RH, Childers KL, Roberts R, Katz R, Waseem R, Robbings BM, Hass DT, Hurley JB, Sweet IR, Goodman C, Qian H, Alvisio B, Heaps S. Transducin-Deficient Rod Photoreceptors Evaluated With Optical Coherence Tomography and Oxygen Consumption Rate Energy Biomarkers. Invest Ophthalmol Vis Sci 2022; 63:22. [PMID: 36576748 PMCID: PMC9804021 DOI: 10.1167/iovs.63.13.22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Purpose To test the hypothesis that rod energy biomarkers in light and dark are similar in mice without functional rod transducin (Gnat1rd17). Methods Gnat1rd17 and wildtype (WT) mice were studied in canonically low energy demand (light) and high energy demand (dark) conditions. We measured rod inner segment ellipsoid zone (ISez) profile shape, external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness, and magnitude of a hyporeflective band (HB) intensity dip located between photoreceptor tips and apical RPE; antioxidants were given in a subset of mice. Oxygen consumption rate (OCR) and visual performance indexes were also measured. Results The lower energy demand expected in light-adapted wildtype retinas was associated with an elongated ISez, thicker ELM-RPE, and higher HB magnitude, and lower OCR compared to high energy demand conditions in the dark. Gnat1rd17 mice showed a wildtype-like ISez profile shape at 20 minutes of light that became rounder at 60 minutes; at both times, ELM-RPE was smaller than wildtype values, and the HB magnitude was unmeasurable. OCR was higher than in the dark. Light-adapted Gnat1rd17 mice biomarkers were unaffected by anti-oxidants. Gnat1rd17 mice showed modest outer nuclear layer thinning and no reduction in visual performance indexes. Conclusions Light-stimulated changes in all biomarkers in WT mice are consistent with the established light-induced decrease in net energy demand. In contrast, biomarker changes in Gnat1rd17 mice raise the possibility that light increases net energy demand in the absence of rod phototransduction.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ryan Katz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Brian M Robbings
- Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington, United States.,Department of Medicine, UW Medicine Diabetes Institute, University of Washington, Seattle, Washington, United States
| | - Daniel T Hass
- Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - James B Hurley
- Department of Biochemistry, Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Ian R Sweet
- Department of Medicine, UW Medicine Diabetes Institute, University of Washington, Seattle, Washington, United States
| | - Cole Goodman
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Bruno Alvisio
- OSIO Bioinformatics Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Sam Heaps
- OSIO Bioinformatics Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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Gao S, Zeng Y, Li Y, Cohen ED, Berkowitz BA, Qian H. Fast and slow light-induced changes in murine outer retina optical coherence tomography: complementary high spatial resolution functional biomarkers. PNAS Nexus 2022; 1:pgac208. [PMID: 36338188 PMCID: PMC9615127 DOI: 10.1093/pnasnexus/pgac208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/21/2022] [Indexed: 11/18/2022]
Abstract
Fast (seconds) and slow (minutes to hours) optical coherence tomography (OCT) responses to light stimulation have been developed to probe outer retinal function with higher spatial resolution than the classical full-field electroretinogram (ERG). However, the relationships between functional information revealed by OCT and ERG are largely unexplored. In this study, we directly compared the fast and slow OCT responses with the ERG. Fast responses [i.e. the optoretinogram (ORG)] are dominated by reflectance changes in the outer segment (OS) and the inner segment ellipsoid zone (ISez). The ORG OS response has faster kinetics and a higher light sensitivity than the ISez response, and both differ significantly with ERG parameters. Sildenafil-inhibition of phototransduction reduced the ORG light sensitivity, suggesting a complete phototransduction pathway is needed for ORG responses. Slower OCT responses were dominated by light-induced changes in the external limiting membrane to retinal pigment epithelium (ELM-RPE) thickness and photoreceptor-tip hyporeflective band (HB) magnitudes, with the biggest changes occurring after prolonged light stimulation. Mice with high (129S6/ev) vs. low (C57BL/6 J) ATP(adenosine triphosphate) synthesis efficiency show similar fast ORG, but dissimilar slow OCT responses. We propose that the ORG reflects passive physiology, such as water movement from photoreceptors, in response to the photocurrent response (measurable by ERG), whereas the slow OCT responses measure mitochondria-driven physiology in the outer retina, such as dark-provoked water removal from the subretinal space.
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Affiliation(s)
- Shasha Gao
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450001, China
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yong Zeng
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ethan D Cohen
- Division of Biomedical Physics, Office of Science and Engineering Labs, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD 20993-0002, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Berkowitz BA, Podolsky RH, Childers KL, Burgoyne T, De Rossi G, Qian H, Roberts R, Katz R, Waseem R, Goodman C. Functional Changes Within the Rod Inner Segment Ellipsoid in Wildtype Mice: An Optical Coherence Tomography and Electron Microscopy Study. Invest Ophthalmol Vis Sci 2022; 63:8. [PMID: 35816042 PMCID: PMC9284466 DOI: 10.1167/iovs.63.8.8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Purpose To test the hypothesis that changing energy needs alter mitochondria distribution within the rod inner segment ellipsoid. Methods In mice with relatively smaller (C57BL/6J [B6J]) or greater (129S6/ev [S6]) retina mitochondria maximum reserve capacity, the profile shape of the rod inner segment ellipsoid zone (ISez) was measured with optical coherence tomography (OCT) under higher (dark) or lower (light) energy demand conditions. ISez profile shape was characterized using an unbiased ellipse descriptor (minor/major aspect ratio). Other bioenergy indexes evaluated include the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness and the magnitude of the signal intensity of a hyporeflective band located between the photoreceptor tips and apical RPE. The spatial distribution of rod ellipsoid mitochondria were also examined with electron microscopy. Results In B6J mice, darkness produced a greater ISez aspect ratio, thinner ELM-RPE, and a smaller hyporeflective band intensity than in light. In S6 mice, dark and light ISez aspect ratio values were not different and were greater than in light-adapted B6J mice; dark-adapted S6 mice showed smaller ELM-RPE thinning versus light, and negligible hyporeflective band intensity in the light. In B6J mice, mitochondria number in light increased in the distal inner segment ellipsoid and decreased proximally. In S6 mice, mitochondria number in the inner segment ellipsoid were not different between light and dark, and were greater than in B6J mice. Conclusions These data raise the possibility that rod mitochondria activity in mice can be noninvasively evaluated based on the ISez profile shape, a new OCT index that complements OCT energy biomarkers measured outside of the ISez region.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, Maryland, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, Unites States
| | - Tom Burgoyne
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Giulia De Rossi
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, Unites States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ryan Katz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Rida Waseem
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Cole Goodman
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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Hubbard WB, Spry ML, Gooch JL, Cloud AL, Vekaria HJ, Burden S, Powell DK, Berkowitz BA, Geldenhuys WJ, Harris NG, Sullivan PG. Clinically relevant mitochondrial-targeted therapy improves chronic outcomes after traumatic brain injury. Brain 2021; 144:3788-3807. [PMID: 34972207 PMCID: PMC8719838 DOI: 10.1093/brain/awab341] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 11/14/2022] Open
Abstract
Pioglitazone, an FDA-approved compound, has been shown to target the novel mitochondrial protein mitoNEET and produce short-term neuroprotection and functional benefits following traumatic brain injury. To expand on these findings, we now investigate the dose- and time-dependent effects of pioglitazone administration on mitochondrial function after experimental traumatic brain injury. We then hypothesize that optimal pioglitazone dosing will lead to ongoing neuroprotection and cognitive benefits that are dependent on pioglitazone-mitoNEET signalling pathways. We show that delayed intervention is significantly more effective than early intervention at improving acute mitochondrial bioenergetics in the brain after traumatic brain injury. In corroboration, we demonstrate that mitoNEET is more heavily expressed, especially near the cortical contusion, in the 18 h following traumatic brain injury. To explore whether these findings relate to ongoing pathological and behavioural outcomes, mice received controlled cortical impact followed by initiation of pioglitazone treatment at either 3 or 18 h post-injury. Mice with treatment initiation at 18 h post-injury exhibited significantly improved behaviour and tissue sparing compared to mice with pioglitazone initiated at 3 h post-injury. Further using mitoNEET knockout mice, we show that this therapeutic effect is dependent on mitoNEET. Finally, we demonstrate that delayed pioglitazone treatment improves serial motor and cognitive performance in conjunction with attenuated brain atrophy after traumatic brain injury. This study illustrates that mitoNEET is the critical target for delayed pioglitazone intervention after traumatic brain injury, mitochondrial-targeting is highly time-dependent after injury and there is an extended therapeutic window to effectively treat mitochondrial dysfunction after brain injury.
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Affiliation(s)
- W Brad Hubbard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
- Department of Physiology, University of Kentucky, Lexington, KY 40508, USA
- Lexington VA Healthcare System, Lexington, KY 40502, USA
| | - Malinda L Spry
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Jennifer L Gooch
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Amber L Cloud
- College of Medicine, University of Kentucky, Lexington, KY 40508, USA
| | - Hemendra J Vekaria
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - Shawn Burden
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
| | - David K Powell
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Werner J Geldenhuys
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV 26506, USA
| | - Neil G Harris
- UCLA Brain Injury Research Center, Department of Neurosurgery, and Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Patrick G Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY 40508, USA
- Lexington VA Healthcare System, Lexington, KY 40502, USA
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Saadane A, Du Y, Thoreson WB, Miyagi M, Lessieur EM, Kiser J, Wen X, Berkowitz BA, Kern TS. Photoreceptor Cell Calcium Dysregulation and Calpain Activation Promote Pathogenic Photoreceptor Oxidative Stress and Inflammation in Prodromal Diabetic Retinopathy. Am J Pathol 2021; 191:1805-1821. [PMID: 34214506 PMCID: PMC8579242 DOI: 10.1016/j.ajpath.2021.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 05/20/2021] [Accepted: 06/15/2021] [Indexed: 12/13/2022]
Abstract
This study tested the hypothesis that diabetes promotes a greater than normal cytosolic calcium level in rod cells that activates a Ca2+-sensitive protease, calpain, resulting in oxidative stress and inflammation, two pathogenic factors of early diabetic retinopathy. Nondiabetic and 2-month diabetic C57Bl/6J and calpain1 knockout (Capn1-/-) mice were studied; subgroups were treated with a calpain inhibitor (CI). Ca2+ content was measured in photoreceptors using Fura-2. Retinal calpain expression was studied by quantitative RT-PCR and immunohistochemistry. Superoxide and expression of inflammatory proteins were measured using published methods. Proteomic analysis was conducted on photoreceptors isolated from untreated diabetic mice or treated daily with CI for 2 months. Cytosolic Ca2+ content was increased twofold in photoreceptors of diabetic mice as compared with nondiabetic mice. Capn1 expression increased fivefold in photoreceptor outer segments of diabetic mice. Pharmacologic inhibition or genetic deletion of Capn1 significantly suppressed diabetes-induced oxidative stress and expression of proinflammatory proteins in retina. Proteomics identified a protein (WW domain-containing oxidoreductase [WWOX]) whose expression was significantly increased in photoreceptors from mice diabetic for 2 months and was inhibited with CI. Knockdown of Wwox using specific siRNA in vitro inhibited increase in superoxide caused by the high glucose. These results suggest that reducing Ca2+ accumulation, suppressing calpain activation, and/or reducing Wwox up-regulation are novel targets for treating early diabetic retinopathy.
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Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology, University of California, Irvine, Irvine, California.
| | - Yunpeng Du
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska; Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, Nebraska
| | - Masaru Miyagi
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Emma M Lessieur
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Jianying Kiser
- Department of Ophthalmology, University of California, Irvine, Irvine, California
| | - Xiangyi Wen
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - Timothy S Kern
- Department of Ophthalmology, University of California, Irvine, Irvine, California; Veterans Administration Medical Center Research Service, Long Beach, California
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10
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MacKinnon MJ, Berkowitz BA, Shih YYI. Superoxide free radical spin-lattice relaxivity: A quench-assisted MR study. Magn Reson Med 2021; 86:1058-1066. [PMID: 33755248 PMCID: PMC8113059 DOI: 10.1002/mrm.28722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 09/06/2020] [Revised: 01/15/2021] [Accepted: 01/17/2021] [Indexed: 12/24/2022]
Abstract
PURPOSE QuEnch-assiSTed (QUEST) MRI provides a unique biomarker of excessive production of paramagnetic free radicals (oxidative stress) in vivo. The contribution from superoxide, a common upstream species found in oxidative stress-based disease, to the QUEST metric is unclear. Here, we begin to address this question by measuring superoxide spin-lattice relaxivity (r1) in phantoms. METHODS Stable superoxide free radicals were generated in water phantoms of potassium superoxide ( KO 2 ) . To measure r1, 1/T1 of different concentration solutions of KO2 in the presence and absence of the antioxidant superoxide dismutase were measured. The 1/T1 confounding factors including acquisition sequence, pH, and water source were also evaluated. RESULTS The T1 -weighted signal intensity increased with KO2 concentration. No contribution from pH, or reaction products other than superoxide, noted on 1/T1 . Superoxide r1 was measured to be 0.29 mM-1 s-1 , in agreement with that reported for paramagnetic molecular oxygen and nitroxide free radicals. CONCLUSION Our first-in-kind measurement of superoxide free radical r1 suggests a detection sensitivity of QUEST MRI on the order of tens of μM, within the reported level of free radical production during oxidative stress in vivo. Similar studies for other common free radicals are needed.
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Affiliation(s)
- Martin J MacKinnon
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State School of Medicine, Detroit, MI, USA
| | - Yen-Yu Ian Shih
- Center for Animal MRI, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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11
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Berkowitz BA, Podolsky RH, Childers KL, Roberts R, Schneider M, Graffice E, Sinan K, Berri A, Harp L. Correcting QUEST Magnetic Resonance Imaging-Sensitive Free Radical Production in the Outer Retina In Vivo Does Not Correct Reduced Visual Performance in 24-Month-Old C57BL/6J Mice. Invest Ophthalmol Vis Sci 2021; 62:24. [PMID: 34036313 PMCID: PMC8164372 DOI: 10.1167/iovs.62.6.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose To test the hypothesis that acutely correcting a sustained presence of outer retina free radicals measured in vivo in 24-month-old mice corrects their reduced visual performance. Methods Male C57BL/6J mice two and 24 months old were noninvasively evaluated for unremitted production of paramagnetic free radicals based on whether 1/T1 in retinal laminae are reduced after acute antioxidant administration (QUEnch-assiSTed [QUEST] magnetic resonance imaging [MRI]). Superoxide production was measured in freshly excised retina (lucigenin assay). Combining acute antioxidant administration with optical coherence tomography (i.e., QUEST OCT) tested for excessive free radical–induced shrinkage of the subretinal space volume. Combining antioxidant administration with optokinetic tracking tested for a contribution of uncontrolled free radical production to cone-based visual performance declines. Results At two months, antioxidants had no effect on 1/T1 in vivo in any retinal layer. At 24 months, antioxidants reduced 1/T1 only in superior outer retina. No age-related change in retinal superoxide production was measured ex vivo, suggesting that free radical species other than superoxide contributed to the positive QUEST MRI signal at 24 months. Also, subretinal space volume did not show evidence for age-related shrinkage and was unresponsive to antioxidants. Finally, visual performance declined with age and was not restored by antioxidants that were effective per QUEST MRI. Conclusions An ongoing uncontrolled production of outer retina free radicals as measured in vivo in 24 mo C57BL/6J mice appears to be insufficient to explain reductions in visual performance.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Michael Schneider
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Emma Graffice
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kenan Sinan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ali Berri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Lamis Harp
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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12
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Abstract
There remains a need for high spatial resolution imaging indices of mitochondrial respiration in the outer retina that probe normal physiology and measure pathogenic and reversible conditions underlying loss of vision. Mitochondria are involved in a critical, but somewhat underappreciated, support system that maintains the health of the outer retina involving stimulus-evoked changes in subretinal space hydration. The subretinal space hydration light-dark response is important because it controls the distribution of vision-critical interphotoreceptor matrix components, including anti-oxidants, pro-survival factors, ions, and metabolites. The underlying signaling pathway controlling subretinal space water management has been worked out over the past 30 years and involves cGMP/mitochondria respiration/pH/RPE water efflux. This signaling pathway has also been shown to be modified by disease-generating conditions, such as hypoxia or oxidative stress. Here, we review recent advances in MRI and commercially available OCT technologies that can measure stimulus-evoked changes in subretinal space water content based on changes in the external limiting membrane-retinal pigment epithelium region. Each step within the above signaling pathway can also be interrogated with FDA-approved pharmaceuticals. A highlight of these studies is the demonstration of first-in-kind in vivo imaging of mitochondria respiration of any cell in the body. Future examinations of subretinal space hydration are expected to be useful for diagnosing threats to sight in aging and disease, and improving the success rate when translating treatments from bench-to-bedside.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
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13
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Gao S, Li Y, Bissig D, Cohen ED, Podolsky RH, Childers KL, Vernon G, Chen S, Berkowitz BA, Qian H. Functional regulation of an outer retina hyporeflective band on optical coherence tomography images. Sci Rep 2021; 11:10260. [PMID: 33986362 PMCID: PMC8119672 DOI: 10.1038/s41598-021-89599-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/27/2021] [Indexed: 12/30/2022] Open
Abstract
Human and animal retinal optical coherence tomography (OCT) images show a hyporeflective band (HB) between the photoreceptor tip and retinal pigment epithelium layers whose mechanisms are unclear. In mice, HB magnitude and the external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness appear to be dependent on light exposure, which is known to alter photoreceptor mitochondria respiration. Here, we test the hypothesis that these two OCT biomarkers are linked to metabolic activity of the retina. Acetazolamide, which acidifies the subretinal space, had no significant impact on HB magnitude but produced ELM-RPE thinning. Mitochondrial stimulation with 2,4-dinitrophenol reduced both HB magnitude and ELM-RPE thickness in parallel, and also reduced F-actin expression in the same retinal region, but without altering ERG responses. For mice strains with relatively lower (C57BL/6J) or higher (129S6/ev) rod mitochondrial efficacy, light-induced changes in HB magnitude and ELM-RPE thickness were correlated. Humans, analyzed from published data captured with a different protocol, showed a similar light–dark change pattern in HB magnitude as in the mice. Our results indicate that mitochondrial respiration underlies changes in HB magnitude upstream of the pH-sensitive ELM-RPE thickness response. These two distinct OCT biomarkers could be useful indices for non-invasively evaluating photoreceptor mitochondrial metabolic activity.
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Affiliation(s)
- Shasha Gao
- Department of Ophthalmology, the First Affiliated Hospital, Zhengzhou University, Zhengzhou, China.,Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David Bissig
- Department of Neurology, University of California Davis, Sacramento, CA, USA
| | - Ethan D Cohen
- Division of Biomedical Physics, Office of Science and Engineering Labs, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, MD, USA
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, MI, 48073, USA
| | | | - Gregory Vernon
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Sonia Chen
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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14
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Berkowitz BA, Podolsky RH, Childers KL, Roche SL, Cotter TG, Graffice E, Harp L, Sinan K, Berri AM, Schneider M, Qian H, Gao S, Roberts R. Rod Photoreceptor Neuroprotection in Dark-Reared Pde6brd10 Mice. Invest Ophthalmol Vis Sci 2021; 61:14. [PMID: 33156341 PMCID: PMC7671864 DOI: 10.1167/iovs.61.13.14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Purpose The purpose of this study was to test the hypothesis that anti-oxidant and / or anti-inflammation drugs that suppress rod death in cyclic light-reared Pde6brd10 mice are also effective in dark-reared Pde6brd10 mice. Methods In untreated dark-reared Pde6brd10 mice at post-natal (P) days 23 to 24, we measured the outer nuclear layer (ONL) thickness (histology) and dark-light thickness difference in external limiting membrane-retinal pigment epithelium (ELM-RPE) (optical coherence tomography [OCT]), retina layer oxidative stress (QUEnch-assiSTed [QUEST] magnetic resonance imaging [MRI]); and microglia/macrophage-driven inflammation (immunohistology). In dark-reared P50 Pde6brd10 mice, ONL thickness was measured (OCT) in groups given normal chow or chow admixed with methylene blue (MB) + Norgestrel (anti-oxidant, anti-inflammatory), or MB or Norgestrel separately. Results P24 Pde6brd10 mice showed no significant dark-light ELM-RPE response in superior and inferior retina consistent with high cGMP levels. Norgestrel did not significantly suppress the oxidative stress of Pde6brd10 mice that is only found in superior central outer retina of males at P23. Overt rod degeneration with microglia/macrophage activation was observed but only in the far peripheral superior retina in male and female P23 Pde6brd10 mice. Significant rod protection was measured in female P50 Pde6brd10 mice given 5 mg/kg/day MB + Norgestrel diet; no significant benefit was seen with MB chow or Norgestrel chow alone, nor in similarly treated male mice. Conclusions In early rod degeneration in dark-reared Pde6brd10 mice, little evidence is found in central retina for spatial associations among biomarkers of the PDE6B mutation, oxidative stress, and rod death; neuroprotection at P50 was limited to a combination of anti-oxidant/anti-inflammation treatment in a sex-specific manner.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Sarah L Roche
- Cell Development and Disease Laboratory, Biochemistry Department, Biosciences Institute, University College Cork, Cork, Ireland
| | - Thomas G Cotter
- Cell Development and Disease Laboratory, Biochemistry Department, Biosciences Institute, University College Cork, Cork, Ireland
| | - Emma Graffice
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Lamis Harp
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kenan Sinan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ali M Berri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Michael Schneider
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Shasha Gao
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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15
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Berkowitz BA, Olds HK, Richards C, Joy J, Rosales T, Podolsky RH, Childers KL, Hubbard WB, Sullivan PG, Gao S, Li Y, Qian H, Roberts R. Novel imaging biomarkers for mapping the impact of mild mitochondrial uncoupling in the outer retina in vivo. PLoS One 2020; 15:e0226840. [PMID: 31923239 PMCID: PMC6953833 DOI: 10.1371/journal.pone.0226840] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/05/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To test the hypothesis that imaging biomarkers are useful for evaluating in vivo rod photoreceptor cell responses to a mitochondrial protonophore. METHODS Intraperitoneal injections of either the mitochondrial uncoupler 2,4 dinitrophenol (DNP) or saline were given to mice with either higher [129S6/eVTac (S6)] or lower [C57BL/6J (B6)] mitochondrial reserve capacities and were studied in dark or light. We measured: (i) the external limiting membrane-retinal pigment epithelium region thickness (ELM-RPE; OCT), which decreases substantially with upregulation of a pH-sensitive water removal co-transporter on the apical portion of the RPE, and (ii) the outer retina R1 (= 1/(spin lattice relaxation time (T1), an MRI parameter proportional to oxygen / free radical content. RESULTS In darkness, baseline rod energy production and consumption are relatively high compared to that in light, and additional metabolic stimulation with DNP provoked thinning of the ELM-RPE region compared to saline injection in S6 mice; ELM-RPE thickness was unresponsive to DNP in B6 mice. Also, dark-adapted S6 mice given DNP showed a decrease in outer retina R1 values compared to saline injection in the inferior retina. In dark-adapted B6 mice, transretinal R1 values were unresponsive to DNP in superior and inferior regions. In light, with its relatively lower basal rod energy production and consumption, DNP caused ELM-RPE thinning in both S6 and B6 mice. CONCLUSIONS The present results raise the possibility of non-invasively evaluating the mouse rod mitochondrial energy ecosystem using new DNP-assisted OCT and MRI in vivo assays.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
- * E-mail:
| | - Hailey K. Olds
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Collin Richards
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Joydip Joy
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Tilman Rosales
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Robert H. Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, MI, United States of America
| | - Karen Lins Childers
- Beaumont Research Institute, Beaumont Health, Royal Oak, MI, United States of America
| | - W. Brad Hubbard
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States of America
| | - Patrick G. Sullivan
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States of America
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States of America
- Lexington VA Health Care System, Lexington, KY, United States of America
| | - Shasha Gao
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
- Department of Ophthalmology, First Affiliated Hospital, Zhengzhou University, Zhengzhou, China
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, United States of America
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16
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Bosse KE, Ghoddoussi F, Eapen AT, Charlton JL, Susick LL, Desai K, Berkowitz BA, Perrine SA, Conti AC. Calcium/calmodulin-stimulated adenylyl cyclases 1 and 8 regulate reward-related brain activity and ethanol consumption. Brain Imaging Behav 2019; 13:396-407. [PMID: 29594872 PMCID: PMC6202255 DOI: 10.1007/s11682-018-9856-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Evidence suggests a predictive link between elevated basal activity within reward-related networks (e.g., cortico-basal ganglia-thalamic networks) and vulnerability for alcoholism. Both calcium channel function and cyclic adenosine monophosphate (cAMP)/protein kinase A-mediated signaling are critical modulators of reward neurocircuitry and reward-related behaviors. Calcium/calmodulin-stimulated adenylyl cyclases (AC) 1 and 8 are sensitive to activity-dependent increases in intracellular calcium and catalyze cAMP production. Therefore, we hypothesized AC1 and 8 regulate brain activity in reward regions of the cortico-basal ganglia-thalamic circuit and that this regulatory influence predicts voluntary ethanol drinking responses. This hypothesis was evaluated by manganese-enhanced magnetic resonance imaging and chronic, intermittent ethanol access procedures. Ethanol-naïve mice with genetic deletion of both AC1 and 8 (DKO mice) exhibited bilateral reductions in baseline activity within cortico-basal ganglia-thalamic regions associated with reward processing compared to wild-type controls (WT, C57BL/6 mice). Significant activity changes were not evident in regions either outside of the cortico-basal ganglia-thalamic network or within the network that are not associated with reward processing. Parallel studies demonstrated that reward network hypoactivity in DKO mice predicted a significant attenuation in consumption and preference levels to escalating ethanol concentrations (12, 20 and 30%) compared to WT mice, an effect that was maintained over extended access (14 sessions) to 20% ethanol. Summarizing, these data support a contribution of AC1 and 8 in cortico-basal ganglia-thalamic activity and the predictive value of this regulatory influence on ethanol drinking behavior, which merits the future evaluation of calcium-stimulated ACs in the neural processes that engender vulnerability to maladaptive alcohol drinking.
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Affiliation(s)
- Kelly E Bosse
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Farhad Ghoddoussi
- Department of Anesthesiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ajay T Eapen
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Jennifer L Charlton
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Laura L Susick
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kirt Desai
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Shane A Perrine
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Alana C Conti
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA.
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA.
- Department of Neurosurgery, Wayne State University, 4646 John R St., Detroit, MI, 48201, USA.
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Sudarshana DM, Nair G, Dwyer JT, Dewey B, Steele SU, Suto DJ, Wu T, Berkowitz BA, Koretsky AP, Cortese ICM, Reich DS. Manganese-Enhanced MRI of the Brain in Healthy Volunteers. AJNR Am J Neuroradiol 2019; 40:1309-1316. [PMID: 31371354 DOI: 10.3174/ajnr.a6152] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/13/2019] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE The manganese ion is used as an intracellular MR imaging contrast agent to study neuronal function in animal models, but it remains unclear whether manganese-enhanced MR imaging can be similarly useful in humans. Using mangafodipir (Teslascan, a chelated manganese-based contrast agent that is FDA-approved), we evaluated the dynamics of manganese enhancement of the brain and glandular structures in the rostral head and neck in healthy volunteers. MATERIALS AND METHODS We administered mangafodipir intravenously at a rate of 1 mL/minute for a total dose of 5 μmol/kg body weight. Nine healthy adult volunteers (6 men/3 women; median age, 43 years) completed baseline history and physical examination, 3T MR imaging, and blood work. MR imaging also followed mangafodipir administration at various time points from immediate to 7 days, with delayed scans at 1-3 months. RESULTS The choroid plexus and anterior pituitary gland enhanced within 10 minutes of infusion, with enhancement persisting up to 7 and 30 days, respectively. Exocrine (parotid, submandibular, sublingual, and lacrimal) glands also enhanced avidly as early as 1 hour postadministration, generally resolving by 1 month; 3 volunteers had residual exocrine gland enhancement, which resolved by 2 months in 1 and by 3 months in the other 2. Mangafodipir did not affect clinical parameters, laboratory values, or T1-weighted signal in the basal ganglia. CONCLUSIONS Manganese ions released from mangafodipir successfully enable noninvasive visualization of intra- and extracranial structures that lie outside the blood-brain barrier without adverse clinical effects, setting the stage for future neuroradiologic investigation in disease.
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Affiliation(s)
- D M Sudarshana
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland.,Cleveland Clinic Lerner College of Medicine of Case Western Reserve University (D.M.S.), Cleveland, Ohio
| | - G Nair
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - J T Dwyer
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - B Dewey
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - S U Steele
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - D J Suto
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - T Wu
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - B A Berkowitz
- Department of Ophthalmology (B.A.B.), Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan
| | - A P Koretsky
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - I C M Cortese
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
| | - D S Reich
- From the National Institute of Neurological Disorders and Stroke (D.M.S., G.N., J.T.D., B.D., S.U.S., D.J.S., T.W., A.P.K., I.C.M.C., D.S.R.), National Institutes of Health, Bethesda, Maryland
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18
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Berkowitz BA, Romero R, Podolsky RH, Lins-Childers KM, Shen Y, Rosales T, Wadghiri YZ, Hoang DM, Arenas-Hernandez M, Garcia-Flores V, Schwenkel G, Panaitescu B, Gomez-Lopez N. QUEST MRI assessment of fetal brain oxidative stress in utero. Neuroimage 2019; 200:601-606. [PMID: 31158477 DOI: 10.1016/j.neuroimage.2019.05.069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/15/2019] [Accepted: 05/27/2019] [Indexed: 01/29/2023] Open
Abstract
PURPOSE To achieve sufficient precision of R1 (=1/T1) maps of the fetal brain in utero to perform QUEnch-assiSTed (QUEST) MRI in which a significant anti-oxidant-induced reduction in R1 indicates oxidative stress. METHODS C57BL/6 mouse fetuses in utero were gently and non-surgically isolated and secured using a homemade 3D printed clip. Using a commercial receive-only surface coil, brain maps of R1, an index sensitive to excessive and continuous free radical production, were collected using either a conventional Cartesian or a non-Cartesian (periodically rotated overlapping parallel lines with enhanced reconstruction) progressive saturation sequence. Data were normalized to the shortest TR time to remove bias. To assess oxidative stress, brain R1 maps were acquired on the lipopolysaccharide (LPS) model of preterm birth ± rosiglitazone (ROSI, which has anti-oxidant properties); phosphate buffered saline (PBS) controls ± ROSI were similarly studied. RESULTS Sufficient quality R1 maps were generated by a combination of the 3D printed clip, surface coil detection, non-Cartesian sequence, and normalization scheme ensuring minimal fetal movement, good detection sensitivity, reduced motion artifacts, and minimal baseline variations, respectively. In the LPS group, the combined caudate-putamen and thalamus region R1 was reduced (p < 0.05) with ROSI treatment consistent with brain oxidative stress; no evidence for oxidative stress was found in the pons region. In the PBS control group, brain R1's did not change with ROSI treatment. CONCLUSION The sensitivity and reproducibility of the combined approaches described herein enabled first-time demonstration of regional oxidative stress measurements of the fetal brain in utero using QUEST MRI.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA.
| | - Roberto Romero
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, University of Michigan Health System, Ann Arbor, Michigan, 48109, USA; Department of Epidemiology and Biostatistics, College of Human Medicine, Michigan State University, East Lansing, Michigan, 48824, USA; Center for Molecular Medicine and Genetics, Wayne State University, Detroit, Michigan, 48201, USA; Detroit Medical Center, Detroit, Michigan, 48201, USA
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, 48073, USA
| | | | - Yimin Shen
- Department of Radiology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - Tilman Rosales
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - Youssef Zaim Wadghiri
- Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), Bernard and Irene Schwartz Center for Biomedical Imaging, NYU School of Medicine and NYU Langone Health, New York, New York, 10016, USA
| | - D Minh Hoang
- Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), Bernard and Irene Schwartz Center for Biomedical Imaging, NYU School of Medicine and NYU Langone Health, New York, New York, 10016, USA
| | - Marcia Arenas-Hernandez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - Valeria Garcia-Flores
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - George Schwenkel
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - Bogdan Panaitescu
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA
| | - Nardhy Gomez-Lopez
- Perinatology Research Branch, Division of Obstetrics and Maternal-Fetal Medicine, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, U.S. Department of Health and Human Services (NICHD/NIH/DHHS), Bethesda, Maryland, 20847, and Detroit, Michigan, 48201, USA; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA; Department of Biochemistry, Microbiology and Immunology, Wayne State University School of Medicine, Detroit, Michigan, 48201, USA.
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Berkowitz BA, Podolsky RH, Qian H, Li Y, Jiang K, Nellissery J, Swaroop A, Roberts R. Mitochondrial Respiration in Outer Retina Contributes to Light-Evoked Increase in Hydration In Vivo. Invest Ophthalmol Vis Sci 2019; 59:5957-5964. [PMID: 30551203 PMCID: PMC6296210 DOI: 10.1167/iovs.18-25682] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose To test the hypothesis that mitochondrial respiration contributes to local changes in hydration involved in phototransduction-driven expansion of outer retina, as measured by structural responses on optical coherence tomography (OCT) and diffusion magnetic resonance imaging (MRI). Methods Oxygen consumption rate and mitochondrial reserve capacity of freshly isolated C57BL/6 and 129S6/SvEvTac mouse retina were measured using a Seahorse Extracellular Flux Analyzer. Light-stimulated outer retina layer water content was determined by proton density MRI, structure and thickness by ultrahigh-resolution OCT, and water mobility by diffusion MRI. Results Compared with C57BL/6 mice, 129S6/SvEvTac retina demonstrated a less robust mitochondrial respiratory basal level, with a higher reserve capacity and lower oxygen consumption in the light, suggesting a relatively lower production of water. C57BL/6 mice showed a light-triggered surge in water content of outer retina in vivo as well as an increase in hyporeflective bands, thickness, and water mobility. In contrast, light did not evoke augmented hydration in this region or an increase in hyporeflective bands or water mobility in the 129S6/SvEvTac outer retina. Nonetheless, we observed a significant but small increase in outer retinal thickness. Conclusions These studies suggest that respiratory-controlled hydration in healthy retina is linked with a localized light-evoked expansion of the posterior retina in vivo and may serve as a useful biomarker of the function of photoreceptor/retinal pigment epithelium complex.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | - Haohua Qian
- Visual Function Core National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Yichao Li
- Visual Function Core National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Ke Jiang
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Jacob Nellissery
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
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20
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Berkowitz BA, Podolsky RH, Lins-Childers KM, Li Y, Qian H. Outer Retinal Oxidative Stress Measured In Vivo Using QUEnch-assiSTed (QUEST) OCT. Invest Ophthalmol Vis Sci 2019; 60:1566-1570. [PMID: 30995313 PMCID: PMC6736344 DOI: 10.1167/iovs.18-26164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/05/2019] [Indexed: 02/06/2023] Open
Abstract
Purpose To test the hypothesis that oxidative stress in the outer retina (OR = distance from external limiting membrane to the retinal pigment epithelium-choroid boundary) can be detected by using antioxidants (AOs) to correct an impaired light-evoked response as measured by optical coherence tomography (OCT). Methods C57BL/6J mice were maintained in the dark for ∼20 hours and studied by OCT before and after 1 hour of light exposure. OR thickness in dark or light was measured, and the light-dark difference (i.e., the photoresponse) was calculated. Subgroups of mice were given either saline or d-cis-diltiazem (an inducer of transient and nondamaging OR oxidative stress) ± methylene blue (24 hours before examination) and α-lipoic acid (1 hour before examination); one group was kept only in the dark and given only AOs. Results In uninjected or saline-injected control mice, the OR showed a similar and reproducible light-induced expansion; dark-adapted mice given AOs did not increase dark-adapted OR thickness. The d-cis-diltiazem-treated mice had no photoresponse (P > 0.05). The d-cis-diltiazem-treated mice given AOs corrected (P < 0.05) the suppressed OR photoresponse, indicating the presence of oxidative stress. Conclusions QUEnch-assiSTed (QUEST) OCT reproduced results from previous gold standard assays, showing that oxidative stress impairs the OR photoresponse and that d-cis-diltiazem produces OR oxidative stress. We envision future applications of QUEST OCT in a range of oxidative stress-based retinopathies.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H. Podolsky
- Beaumont Research Institute, Beaumont Health, Royal Oak, Michigan, United States
| | | | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
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21
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Berkowitz BA, Podolsky RH, Farrell B, Lee H, Trepanier C, Berri AM, Dernay K, Graffice E, Shafie-Khorassani F, Kern TS, Roberts R. D-cis-Diltiazem Can Produce Oxidative Stress in Healthy Depolarized Rods In Vivo. Invest Ophthalmol Vis Sci 2019; 59:2999-3010. [PMID: 30025125 PMCID: PMC5995482 DOI: 10.1167/iovs.18-23829] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Purpose New perspectives are needed to understand decades of contradictory reports on the neuroprotective effects of the Cav1.2 L-type calcium channel blocker d-cis-diltiazem in retinitis pigmentosa (RP) models. Here, we address, in vivo, the following two knowledge gaps regarding d-cis-diltiazem's actions in the murine outer retina: (1) do normal mouse rods contain d-cis-diltiazem-insensitive Cav1.2 L-type calcium channels? (2) Can d-cis-diltiazem modify the normal rod redox environment? Methods First, transretinal Cav1.2 L-type calcium channels were noninvasively mapped with manganese-enhanced magnetic resonance imaging (MRI) following agonist Bay K 8644 in C57BL/6 (B6) and in Cav1.2 L-type calcium channel BAY K 8644-insensitive mutant B6 mice. Second, d-cis-diltiazem-treated oxidative stress-vulnerable (B6) or -resistant [129S6 (S6)] mice were examined in vivo (QUEnch-assiSTed [QUEST] MRI) and in whole retina ex vivo (lucigenin). Retinal thickness was measured using MRI. Results The following results were observed: (1) manganese uptake patterns in BAY K 8644-treated controls and mutant mice identified in vivo Cav1.2 L-type calcium channels in inner and outer retina; and (2) d-cis-diltiazem induced rod oxidative stress in dark-adapted B6 mice but not in light-adapted B6 mice or dark-adapted S6 mice (QUEST MRI). Oxidative stress in vivo was limited to inferior outer retina in dark-adapted B6 mice approximately 1-hour post d-cis-diltiazem. By approximately 4 hours post, only superior outer retina oxidative stress was observed and whole retinal superoxide production was supernormal. All groups had unremarkable retinal thicknesses. Conclusions D-cis-diltiazem's unexpectedly complex spatiotemporal outer retinal oxidative stress pattern in vivo was dependent on genetic background and rod membrane depolarization, but not apparently dependent on Cav1.2 L-type calcium channels, providing a potential rationale for contradictory results in different RP models.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States.,Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Benjamin Farrell
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Hojun Lee
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Christopher Trepanier
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ali M Berri
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kristin Dernay
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Emma Graffice
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Fatema Shafie-Khorassani
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Timothy S Kern
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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Berkowitz BA, Podolsky RH, Berri AM, Dernay K, Graffice E, Shafie-Khorassani F, Roberts R. Dark Rearing Does Not Prevent Rod Oxidative Stress In Vivo in Pde6brd10 Mice. Invest Ophthalmol Vis Sci 2018; 59:1659-1665. [PMID: 29625492 PMCID: PMC5868999 DOI: 10.1167/iovs.17-22734] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Purpose In cyclic light-reared Pde6brd10 mice, rod cell oxidative stress contributes to the degenerative phenotype. Dark rearing Pde6brd10 mice slows but does not prevent atrophy. This suggests that outer retinal oxidative stress occurs in Pde6brd10 mice independent of light exposure, a hypothesis tested in this study. Methods Mouse strains Pde6brd10 and C57Bl/6 (wild type) were dark reared until postnatal day (P) 23 (P23) or P30. In subgroups of dark-reared mice, (1) layer-specific excessive free radical production (i.e., an oxidative stress biomarker) in vivo via QUEnch-assiSTed magnetic resonance imaging (QUEST MRI) was indicated by a significant reduction in the greater-than-normal spin-lattice relaxation rate R1 (1/T1) with methylene blue, (2) superoxide production was measured ex vivo in whole retina (lucigenin), and (3) retinal layer spacing and thickness were assessed in vivo (optical coherence tomography, MRI). Results In P23 male Pde6brd10 mice, only the outer superior retina showed oxidative stress in vivo, as measured by QUEST MRI; a lucigenin assay confirmed supernormal superoxide production. In contrast, at P30, no evidence for retinal oxidative stress was observed. In P23 female Pde6brd10 mice, no retinal oxidative stress was apparent; however, at P30, oxidative stress was observed in superior inner and outer nuclear layers. Male and female Pde6brd10 mice at P23 had normal retinal thicknesses, whereas at P30, modest thinning was noted in inferior and superior retina. Conclusions We confirmed that outer retinal oxidative stress occurs in male and female dark-reared Pde6brd10 mice. Male and female Pde6brd10 mice demonstrated similar degrees of retinal thinning, but with unexpectedly distinct spatial and temporal retinal oxidative stress patterns.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States.,Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Ali M Berri
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kristin Dernay
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Emma Graffice
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Fatema Shafie-Khorassani
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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Berkowitz BA. Oxidative stress measured in vivo without an exogenous contrast agent using QUEST MRI. J Magn Reson 2018; 291:94-100. [PMID: 29705036 PMCID: PMC5963509 DOI: 10.1016/j.jmr.2018.01.013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 01/09/2018] [Accepted: 01/24/2018] [Indexed: 05/10/2023]
Abstract
Decades of experimental studies have implicated excessive generation of reactive oxygen species (ROS) in the decline of tissue function during normal aging, and as a pathogenic factor in a vast array of fatal or debilitating morbidities. This massive body of work has important clinical implications since many antioxidants are FDA approved, readily cross blood-tissue barriers, and are effective at improving disease outcomes. Yet, the potential benefits of antioxidants have remained largely unrealized in patients because conventional methods cannot determine the dose, timing, and drug combinations to be used in clinical trials to localize and decrease oxidative stress. To address this major problem and improve translational success, new methods are urgently needed that non-invasively measure the same ROS biomarker both in animal models and patients with high spatial resolution. Here, we summarize a transformative solution based on a novel method: QUEnch-assiSTed MRI (QUEST MRI). The QUEST MRI index is a significant antioxidant-induced improvement in pathophysiology, or a reduction in 1/T1 (i.e., R1). The latter form of QUEST MRI provides a unique measure of uncontrolled production of endogenous, paramagnetic reactive oxygen species (ROS). QUEST MRI results to-date have been validated by gold standard oxidative stress assays. QUEST MRI has high translational potential because it does not use an exogenous contrast agent and requires only standard MRI equipment. Summarizing, QUEST MRI is a powerful non-invasive approach with unprecedented potential for (i) bridging antioxidant treatment in animal models and patients, (ii) identifying tissue subregions exhibiting oxidative stress, and (iii) coupling oxidative stress localization with behavioral dysfunction, disease pathology, and genetic vulnerabilities to serve as a marker of susceptibility.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, United States; Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI 48201, United States.
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Muca A, Standafer E, Apawu AK, Ahmad F, Ghoddoussi F, Hali M, Warila J, Berkowitz BA, Holt AG. Tinnitus and temporary hearing loss result in differential noise-induced spatial reorganization of brain activity. Brain Struct Funct 2018; 223:2343-2360. [PMID: 29488007 PMCID: PMC6129978 DOI: 10.1007/s00429-018-1635-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 06/27/2017] [Accepted: 02/17/2018] [Indexed: 12/27/2022]
Abstract
Loud noise frequently results in hyperacusis or hearing loss (i.e., increased or decreased sensitivity to sound). These conditions are often accompanied by tinnitus (ringing in the ears) and changes in spontaneous neuronal activity (SNA). The ability to differentiate the contributions of hyperacusis and hearing loss to neural correlates of tinnitus has yet to be achieved. Towards this purpose, we used a combination of behavior, electrophysiology, and imaging tools to investigate two models of noise-induced tinnitus (either with temporary hearing loss or with permanent hearing loss). Manganese (Mn2+) uptake was used as a measure of calcium channel function and as an index of SNA. Manganese uptake was examined in vivo with manganese-enhanced magnetic resonance imaging (MEMRI) in key auditory brain regions implicated in tinnitus. Following acoustic trauma, MEMRI, the SNA index, showed evidence of spatially dependent rearrangement of Mn2+ uptake within specific brain nuclei (i.e., reorganization). Reorganization of Mn2+ uptake in the superior olivary complex and cochlear nucleus was dependent upon tinnitus status. However, reorganization of Mn2+ uptake in the inferior colliculus was dependent upon hearing sensitivity. Furthermore, following permanent hearing loss, reduced Mn2+ uptake was observed. Overall, by combining testing for hearing sensitivity, tinnitus, and SNA, our data move forward the possibility of discriminating the contributions of hyperacusis and hearing loss to tinnitus.
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Affiliation(s)
- Antonela Muca
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - Emily Standafer
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - Aaron K Apawu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - Farhan Ahmad
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - Farhad Ghoddoussi
- Department of Anesthesiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Mirabela Hali
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - James Warila
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
| | - Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Avril Genene Holt
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, 550 East Canfield Ave., Detroit, MI, 48201, USA.
- John D. Dingell VAMC, Detroit, MI, USA.
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Huereca DJ, Bakoulas KA, Ghoddoussi F, Berkowitz BA, Holt AG, Mueller PJ. Development of manganese-enhanced magnetic resonance imaging of the rostral ventrolateral medulla of conscious rats: Importance of normalization and comparison with other regions of interest. NMR Biomed 2018; 31:10.1002/nbm.3887. [PMID: 29327782 PMCID: PMC5819885 DOI: 10.1002/nbm.3887] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 11/19/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
Spinally projecting neurons in the rostral ventrolateral medulla (RVLM) are believed to contribute to pathophysiological alterations in sympathetic nerve activity and the development of cardiovascular disease. The ability to identify changes in the activity of RVLM neurons in conscious animals and humans, especially longitudinally, would represent a clinically important advancement in our understanding of the contribution of the RVLM to cardiovascular disease. To this end, we describe the initial development of manganese-enhanced magnetic resonance imaging (MEMRI) for the rat RVLM. Manganese (Mn2+ ) has been used to estimate in vivo neuronal activity in other brain regions because of both its paramagnetic properties and its entry into and accumulation in active neurons. In this initial study, our three goals were as follows: (1) to validate that Mn2+ enhancement occurs in functionally and anatomically localized images of the rat RVLM; (2) to quantify the dose and time course dependence of Mn2+ enhancement in the RVLM after one systemic injection in conscious rats (66 or 33 mg/kg, intraperitoneally); and (3) to compare Mn2+ enhancement in the RVLM with other regions to determine an appropriate method of normalization of T1 -weighted images. In our proof-of-concept and proof-of-principle studies, Mn2+ was identified by MRI in the rat RVLM after direct microinjection or via retrograde transport following spinal cord injections, respectively. Systemic injections in conscious rats produced significant Mn2+ enhancement at 24 h (p < 0.05). Injections of 66 mg/kg produced greater enhancement than 33 mg/kg in the RVLM and paraventricular nucleus of the hypothalamus (p < 0.05 for both), but only when normalized to baseline scans without Mn2+ injection. Consistent with findings from our previous functional and anatomical studies demonstrating subregional neuroplasticity, Mn2+ enhancement was higher in the rostral regions of the RVLM (p < 0.05). Together with important technical considerations, our studies support the development of MEMRI as a potential method to examine RVLM activity over time in conscious animal subjects.
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Affiliation(s)
- Daniel J. Huereca
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI
| | | | - Farhad Ghoddoussi
- Department of Anesthesiology, Wayne State University School of Medicine, Detroit, MI
| | - Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI
- Department of Opthlamology, Wayne State University School of Medicine, Detroit, MI
| | - Avril Genene Holt
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI
- John Dingell Veterans Administration Medical Center, Detroit, MI
| | - Patrick J. Mueller
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI
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Berkowitz BA, Podolsky RH, Lenning J, Khetarpal N, Tran C, Wu JY, Berri AM, Dernay K, Shafie-Khorassani F, Roberts R. Sodium Iodate Produces a Strain-Dependent Retinal Oxidative Stress Response Measured In Vivo Using QUEST MRI. Invest Ophthalmol Vis Sci 2017; 58:3286-3293. [PMID: 28666279 PMCID: PMC5493331 DOI: 10.1167/iovs.17-21850] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose We identify noninvasive biomarkers that measure the severity of oxidative stress within retina layers in sodium iodate (SI)-atrophy vulnerable (C57BL/6 [B6]) and SI-atrophy resistant (129S6/SvEvTac [S6]) mice. Methods At 24 hours after administering systemic SI to B6 and S6 mice we measured: (1) superoxide production in whole retina ex vivo, (2) excessive free radical production in vivo based on layer-specific 1/T1 values before and after α-lipoic acid (ALA) administration while the animal was inside the magnet (QUEnch-assiSTed MRI [QUEST MRI]), and (3) visual performance (optokinetic tracking) ± antioxidants; control mice were similarly assessed. Retinal layer spacing and thickness in vivo also were evaluated (optical coherence tomography, MRI). Results SI-treated B6 mice retina had a significantly higher superoxide production than SI-treated S6 mice. ALA-injected SI-treated B6 mice had reduced 1/T1 in more retinal layers in vivo than in SI-treated S6 mice. Uninjected and saline-injected SI-treated B6 mice had similar transretinal 1/T1 profiles. Notably, the inner segment layer 1/T1 of SI-treated B6 mice was responsive to ALA but was unresponsive in SI-treated S6 mice. In both SI-treated strains, antioxidants improved contrast sensitivity to similar extents; antioxidants did not change acuity in either group. Retinal thicknesses were normal in both SI-treated strains at 24 hours after treatment. Conclusions QUEST MRI uniquely measured severity of excessive free radical production within retinal layers of the same subject. Identifying the mechanisms underlying genetic vulnerabilities to oxidative stress is expected to help in understanding the pathogenesis of retinal degeneration.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States 2Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robert H Podolsky
- Deptarment of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Jacob Lenning
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Nikita Khetarpal
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Catherine Tran
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Johnny Y Wu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ali M Berri
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Kristin Dernay
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Fatema Shafie-Khorassani
- Deptarment of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States
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Berkowitz BA, Lenning J, Khetarpal N, Tran C, Wu JY, Berri AM, Dernay K, Haacke EM, Shafie-Khorassani F, Podolsky RH, Gant JC, Maimaiti S, Thibault O, Murphy GG, Bennett BM, Roberts R. In vivo imaging of prodromal hippocampus CA1 subfield oxidative stress in models of Alzheimer disease and Angelman syndrome. FASEB J 2017; 31:4179-4186. [PMID: 28592637 DOI: 10.1096/fj.201700229r] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 05/22/2017] [Indexed: 12/13/2022]
Abstract
Hippocampus oxidative stress is considered pathogenic in neurodegenerative diseases, such as Alzheimer disease (AD), and in neurodevelopmental disorders, such as Angelman syndrome (AS). Yet clinical benefits of antioxidant treatment for these diseases remain unclear because conventional imaging methods are unable to guide management of therapies in specific hippocampus subfields in vivo that underlie abnormal behavior. Excessive production of paramagnetic free radicals in nonhippocampus brain tissue can be measured in vivo as a greater-than-normal 1/T1 that is quenchable with antioxidant as measured by quench-assisted (Quest) MRI. Here, we further test this approach in phantoms, and we present proof-of-concept data in models of AD-like and AS hippocampus oxidative stress that also exhibit impaired spatial learning and memory. AD-like models showed an abnormal gradient along the CA1 dorsal-ventral axis of excessive free radical production as measured by Quest MRI, and redox-sensitive calcium dysregulation as measured by manganese-enhanced MRI and electrophysiology. In the AS model, abnormally high free radical levels were observed in dorsal and ventral CA1. Quest MRI is a promising in vivo paradigm for bridging brain subfield oxidative stress and behavior in animal models and in human patients to better manage antioxidant therapy in devastating neurodegenerative and neurodevelopmental diseases.-Berkowitz, B. A., Lenning, J., Khetarpal, N., Tran, C., Wu, J. Y., Berri, A. M., Dernay, K., Haacke, E. M., Shafie-Khorassani, F., Podolsky, R. H., Gant, J. C., Maimaiti, S., Thibault, O., Murphy, G. G., Bennett, B. M., Roberts, R. In vivo imaging of prodromal hippocampus CA1 subfield oxidative stress in models of Alzheimer disease and Angelman syndrome.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA; .,Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Jacob Lenning
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Nikita Khetarpal
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Catherine Tran
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Johnny Y Wu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Ali M Berri
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Kristin Dernay
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - E Mark Haacke
- Department of Radiology, Wayne State University, Detroit, Michigan, USA
| | - Fatema Shafie-Khorassani
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Robert H Podolsky
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - John C Gant
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Shaniya Maimaiti
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Olivier Thibault
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Brian M Bennett
- Centre for Neuroscience Studies, Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
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Berkowitz BA, Schmidt T, Podolsky RH, Roberts R. Melanopsin Phototransduction Contributes to Light-Evoked Choroidal Expansion and Rod L-Type Calcium Channel Function In Vivo. Invest Ophthalmol Vis Sci 2017; 57:5314-5319. [PMID: 27727394 PMCID: PMC5063053 DOI: 10.1167/iovs.16-20186] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose In humans, rodents, and pigeons, the dark → light transition signals nonretinal brain tissue to increase choroidal thickness, a major control element of choroidal blood flow, and thus of photoreceptor and retinal pigment epithelium function. However, it is unclear which photopigments in the retina relay the light signal to the brain. Here, we test the hypothesis that melanopsin (Opn4)-regulated phototransduction modulates light-evoked choroidal thickness expansion in mice. Methods Two-month-old C57Bl/6 wild-type (B6), 4- to 5-month-old C57Bl/6/129S6 wild-type (B6 + S6), and 2-month-old melanopsin knockout (Opn4−/−) on a B6 + S6 background were studied. Retinal anatomy was evaluated in vivo by optical coherence tomography and MRI. Choroidal thickness in dark and light were measured by diffusion-weighted MRI. Rod cell L-type calcium channel (LTCC) function in dark and light (manganese-enhanced MRI [MEMRI]) was also measured. Results Opn4−/− mice did not show the light-evoked expansion of choroidal thickness observed in B6 and B6 + S6 controls. Additionally, Opn4−/− mice had lower than normal rod cell and inner retinal LTCC function in the dark but not in the light. These deficits were not due to structural abnormalities because retinal laminar architecture and thickness, and choroidal thickness in the Opn4−/− mice were similar to controls. Conclusions First time evidence is provided that melanopsin phototransduction contributes to dark → light control of murine choroidal thickness. The data also highlight a contribution in vivo of melanopsin phototransduction to rod cell and inner retinal depolarization in the dark.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States 2Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
| | - Tiffany Schmidt
- Department of Neurobiology, Northwestern University, Evanston, Illinois, United States
| | - Robert H Podolsky
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
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Berkowitz BA, Miller RA, Roberts R. Genetically heterogeneous mice show age-related vision deficits not related to increased rod cell L-type calcium channel function in vivo. Neurobiol Aging 2016; 49:198-203. [PMID: 27823846 DOI: 10.1016/j.neurobiolaging.2016.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/22/2016] [Accepted: 09/15/2016] [Indexed: 12/18/2022]
Abstract
Visual performance declines over time in humans and 2-18 months outbred Long-Evans (LE) rats; vision is maintained in inbred 2-18 months C57BL/6 (B6) mice. Increased rod L-type calcium channel (LTCC) function predicts visual decline in LE rats but does not occur in B6 mice. Genetic diversity may contribute to rod LTCC function escalation time. To test this hypothesis, 4 and 18 months genetically heterogeneous UM-HET3 mice were studied. Rod LTCC function (manganese-enhanced magnetic resonance imaging [MRI]) and ocular anatomy (MRI, optical coherence tomography) were measured in vivo. Light-evoked subretinal space and choroid thickness changes were measured (diffusion-weighted MRI). Visual performance declined over time in the absence of (1) increased rod LTCC function; (2) changes in light-dependent expansion of the subretinal space and choroidal thickness; and (3) retinal thinning. Aging changed anterior and vitreous chambers' axial length and decreased light-stimulated choroidal expansion. Species differences appear to contribute to the LTCC function differences. Aging-related declines in vision in the UM-HET3 mice deserve more attention than they have received so far.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA; Department Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Richard A Miller
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Robin Roberts
- Department Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
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Berkowitz BA, Lewin AS, Biswal MR, Bredell BX, Davis C, Roberts R. MRI of Retinal Free Radical Production With Laminar Resolution In Vivo. Invest Ophthalmol Vis Sci 2016; 57:577-85. [PMID: 26886890 PMCID: PMC4771178 DOI: 10.1167/iovs.15-18972] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Recent studies have suggested the hypothesis that quench-assisted 1/T1 magnetic resonance imaging (MRI) measures free radical production with laminar resolution in vivo without the need of a contrast agent. Here, we test this hypothesis further by examining the spatial and detection sensitivity of quench-assisted 1/T1 MRI to strain, age, or retinal cell layer-specific genetic manipulations. Methods We studied: adult wild-type mice; mice at postnatal day 7 (P7); cre dependent retinal pigment epithelium (RPE)-specific MnSOD knockout mice; doxycycline-treated Sod2flox/flox mice lacking the cre transgene; and α-transducin knockout (Gnat1−/−) mice on a C57Bl/6 background. Transretinal 1/T1 profiles were mapped in vivo in the dark without or with antioxidant treatment, or followed by light exposure. We calibrated profiles spatially using optical coherence tomography. Results Dark-adapted RPE-specific MnSOD knockout mice had greater than normal 1/T1 in the RPE and outer nuclear layers that was corrected to wild-type levels by antioxidant treatment. Dark and light Gnat1−/− mice also had greater than normal outer retinal 1/T1 values. In adult wild-type mice, dark values of 1/T1 in the ellipsoid region and in the outer segment were suppressed by 13 minutes of light. By 29 minutes of light, 1/T1 reduction extended to the outer nuclear layer. Gnat1−/− mice demonstrated a faster light-evoked suppression of 1/T1 values in the outer retina. In P7 mice, transretinal 1/T1 profiles were the same in dark and light. Conclusions Quench-assisted MRI has the laminar resolution and detection sensitivity to evaluate normal and pathologic production of free radicals in vivo.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States 2Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, United States
| | - Manas R Biswal
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, United States
| | - Bryce X Bredell
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Christopher Davis
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
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Berkowitz BA, Bredell BX, Davis C, Samardzija M, Grimm C, Roberts R. Measuring In Vivo Free Radical Production by the Outer Retina. Invest Ophthalmol Vis Sci 2016; 56:7931-8. [PMID: 26670830 DOI: 10.1167/iovs.15-18420] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE Excessive and continuously produced free radicals in the outer retina are implicated in retinal aging and the pathogenesis of sight-threatening retinopathies, yet measuring outer retinal oxidative stress in vivo remains a challenge. Here, we test the hypothesis that continuously produced paramagnetic free radicals from the outer retina can be measured in vivo using high-resolution (22-μm axial resolution) 1/T1magnetic resonance imaging (MRI) without and with a confirmatory quench (quench-assisted MRI). METHODS Low-dose sodium iodate-treated and diabetic C57Bl6/J mice (and their controls), and rod-dominated (129S6) or cone-only R91W;Nrl-/- mice were studied. In dark-adapted groups, 1/T1 was mapped transretinally in vivo without or with (1) the antioxidant combination of methylene blue (MB) and α-lipoic acid (LPA), or (2) light exposure; in subgroups, retinal superoxide production was measured ex vivo (lucigenin). RESULTS In the sodium iodate model, retinal superoxide production and outer retina-specific 1/T1 values were both significantly greater than normal and corrected to baseline with MB+LPA therapy. Nondiabetic mice at two ages and 1.2-month diabetic mice (before the appearance of oxidative stress) had similar transretinal 1/T1 profiles. By 2.3 months of diabetes, only outer retinal 1/T1 values were significantly greater than normal and were corrected to baseline with MB+LPA therapy. In mice with healthy photoreceptors, a light quench caused 1/T1 of rods, but not cones, to significantly decrease from their values in the dark. CONCLUSIONS Quench-assisted MRI is a feasible method for noninvasively measuring normal and pathologic production of free radicals in photoreceptors/RPE in vivo.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States 2Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Bryce X Bredell
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Christopher Davis
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Marijana Samardzija
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Switzerland
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Switzerland
| | - Robin Roberts
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
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Perrine SA, Ghoddoussi F, Desai K, Kohler RJ, Eapen AT, Lisieski MJ, Angoa-Perez M, Kuhn DM, Bosse KE, Conti AC, Bissig D, Berkowitz BA. Cocaine-induced locomotor sensitization in rats correlates with nucleus accumbens activity on manganese-enhanced MRI. NMR Biomed 2015; 28:1480-1488. [PMID: 26411897 PMCID: PMC4618766 DOI: 10.1002/nbm.3409] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 08/18/2015] [Accepted: 08/21/2015] [Indexed: 06/05/2023]
Abstract
A long-standing goal of substance abuse research has been to link drug-induced behavioral outcomes with the activity of specific brain regions to understand the neurobiology of addiction behaviors and to search for drug-able targets. Here, we tested the hypothesis that cocaine produces locomotor (behavioral) sensitization that correlates with increased calcium channel-mediated neuroactivity in brain regions linked with drug addiction, such as the nucleus accumbens (NAC), anterior striatum (AST) and hippocampus, as measured using manganese-enhanced MRI (MEMRI). Rats were treated with cocaine for 5 days, followed by a 2-day drug-free period. The following day, locomotor sensitization was quantified as a metric of cocaine-induced neuroplasticity in the presence of manganese. Immediately following behavioral testing, rats were examined for changes in calcium channel-mediated neuronal activity in the NAC, AST, hippocampus and temporalis muscle, which was associated with behavioral sensitization using MEMRI. Cocaine significantly increased locomotor activity and produced behavioral sensitization compared with saline treatment of control rats. A significant increase in MEMRI signal intensity was determined in the NAC, but not AST or hippocampus, of cocaine-treated rats compared with saline-treated control rats. Cocaine did not increase signal intensity in the temporalis muscle. Notably, in support of our hypothesis, behavior was significantly and positively correlated with MEMRI signal intensity in the NAC. As neuronal uptake of manganese is regulated by calcium channels, these results indicate that MEMRI is a powerful research tool to study neuronal activity in freely behaving animals and to guide new calcium channel-based therapies for the treatment of cocaine abuse and dependence.
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Affiliation(s)
- Shane A. Perrine
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Farhad Ghoddoussi
- Department of Anesthesiology, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Kirtan Desai
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Robert J. Kohler
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Ajay T. Eapen
- Department of Neurosurgery, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Research Services, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Michael J. Lisieski
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Mariana Angoa-Perez
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Research Services, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Donald M. Kuhn
- Department of Psychiatry and Behavioral Neurosciences, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Research Services, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Kelly E. Bosse
- Department of Neurosurgery, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Research Services, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Alana C. Conti
- Department of Neurosurgery, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Research Services, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - David Bissig
- Department of Anatomy and Cell Biology, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
| | - Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
- Department of Ophthalmology, Wayne State University School of Medicine, John D. Dingell Veterans Affairs Medical Center, Detroit, MI
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Berkowitz BA, Murphy GG, Craft CM, Surmeier DJ, Roberts R. Genetic dissection of horizontal cell inhibitory signaling in mice in complete darkness in vivo. Invest Ophthalmol Vis Sci 2015; 56:3132-9. [PMID: 26024096 DOI: 10.1167/iovs.15-16581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
PURPOSE To test the hypothesis that horizontal cell (HC) inhibitory signaling controls the degree to which rod cell membranes are depolarized as measured by the extent to which L-type calcium channels (LTCCs) are open in complete darkness in the mouse retina in vivo. METHODS Dark-adapted wild-type (wt), CACNA1F (Ca(v)1.4(-/-)), arrestin-1 (Arr1(-/-)), and CACNA1D (Ca(v)1.3(-/-)) C57Bl/6 mice were studied. Manganese-enhanced MRI (MEMRI) evaluated the extent that rod LTCCs are open as an index of loss of HC inhibitory signaling. Subgroups were pretreated with D-cis-diltiazem (DIL) at a dose that specifically antagonizes Ca(v)1.2 channels in vivo. RESULTS Knockout mice predicted to have impaired HC inhibitory signaling (Ca(v)1.4(-/-) or Arr1(-/-)) exhibited greater than normal rod manganese uptake; inner retinal uptake was also supernormal. Genetically knocking out a closely associated gene not expected to impact HC inhibitory signaling (CACNA1D) did not generate this phenotype. The Arr1(-/-) mice exhibited the largest rod uptake of manganese. Manganese-enhanced MRI of DIL-treated Arr1(-/-) mice suggested a greater number of operant LTCC subtypes (i.e., Ca(v)1.2, 1.3, and 1.4) in rods and inner retina than that in DIL-treated Ca(v)1.4(-/-) mice (i.e., Ca(v)1.3). The Ca(v)1.3(-/-) + DIL-treated mice exhibited evidence for a compensatory contribution from Ca(v)1.2 LTCCs. CONCLUSIONS The data suggest that loss of HC inhibitory signaling is the proximate cause leading to maximally open LTCCs in rods, and possibly inner retinal cells, in mice in total darkness in vivo, regardless of compensatory changes in LTCC subtype manifested in the mutant mice.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States 2Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Geoffrey G Murphy
- University of Michigan Medical School, Molecular Behavioral Neuroscience Institute, Molecular and Integrative Physiology, Ann Arbor, Michigan, United States
| | - Cheryl Mae Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, and Department of Ophthalmology and Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California, United States
| | - D James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
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Giordano CR, Roberts R, Krentz KA, Bissig D, Talreja D, Kumar A, Terlecky SR, Berkowitz BA. Catalase therapy corrects oxidative stress-induced pathophysiology in incipient diabetic retinopathy. Invest Ophthalmol Vis Sci 2015; 56:3095-102. [PMID: 25813998 DOI: 10.1167/iovs.14-16194] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
PURPOSE Preclinical studies have highlighted retinal oxidative stress in the pathogenesis of diabetic retinopathy. We evaluated whether a treatment designed to enhance cellular catalase reduces oxidative stress in retinal cells cultured in high glucose and in diabetic mice corrects an imaging biomarker responsive to antioxidant therapy (manganese-enhanced magnetic resonance imaging [MEMRI]). METHODS Human retinal Müller and pigment epithelial cells were chronically exposed to normal or high glucose levels and treated with a cell-penetrating derivative of the peroxisomal enzyme catalase (called CAT-SKL). Hydrogen peroxide (H2O2) levels were measured using a quantitative fluorescence-based assay. For in vivo studies, streptozotocin (STZ)-induced diabetic C57Bl/6 mice were treated subcutaneously once a week for 3 to 4 months with CAT-SKL; untreated age-matched nondiabetic controls and untreated diabetic mice also were studied. MEMRI was used to analytically assess the efficacy of CAT-SKL treatment on diabetes-evoked oxidative stress-related pathophysiology in vivo. Similar analyses were performed with difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. RESULTS After catalase transduction, high glucose-induced peroxide production was significantly lowered in both human retinal cell lines. In diabetic mice in vivo, subnormal intraretinal uptake of manganese was significantly improved by catalase supplementation. In addition, in the peroxisome-rich liver of treated mice catalase enzyme activity increased and oxidative damage (as measured by lipid peroxidation) declined. On the other hand, DFMO was largely without effect in these in vitro or in vivo assays. CONCLUSIONS This proof-of-concept study raises the possibility that augmentation of catalase is a therapy for treating the retinal oxidative stress associated with diabetic retinopathy.
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Affiliation(s)
- Courtney R Giordano
- Department of Pharmacology, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Kendra A Krentz
- Department of Pharmacology, Wayne State University, Detroit, Michigan, United States
| | - David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Deepa Talreja
- Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
| | - Ashok Kumar
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States 3Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
| | - Stanley R Terlecky
- Department of Pharmacology, Wayne State University, Detroit, Michigan, United States
| | - Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States 3Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
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Berkowitz BA, Kern TS, Bissig D, Patel P, Bhatia A, Kefalov VJ, Roberts R. Systemic Retinaldehyde Treatment Corrects Retinal Oxidative Stress, Rod Dysfunction, and Impaired Visual Performance in Diabetic Mice. Invest Ophthalmol Vis Sci 2015; 56:6294-303. [PMID: 26431483 PMCID: PMC4594469 DOI: 10.1167/iovs.15-16990] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [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: 03/30/2015] [Accepted: 08/04/2015] [Indexed: 12/20/2022] Open
Abstract
PURPOSE Diabetes appears to induce a visual cycle defect because rod dysfunction is correctable with systemic treatment of the visual cycle chromophore 11-cis-retinaldehyde. However, later studies have found no evidence for visual cycle impairment. Here, we further examined whether photoreceptor dysfunction is corrected with 11-cis-retinaldehyde. Because antioxidants correct photoreceptor dysfunction in diabetes, the hypothesis that exogenous visual chromophores have antioxidant activity in the retina of diabetic mice in vivo was tested. METHODS Rod function in 2-month-old diabetic mice was evaluated using transretinal electrophysiology in excised retinas and apparent diffusion coefficient (ADC) MRI to measure light-evoked expansion of subretinal space (SRS) in vivo. Optokinetic tracking was used to evaluate cone-based visual performance. Retinal production of superoxide free radicals, generated mostly in rod cells, was biochemically measured with lucigenin. Diabetic mice were systemically treated with a single injection of either 11-cis-retinaldehyde, 9-cis-retinaldehyde (a chromophore surrogate), or all-trans-retinaldehyde (the photoisomerization product of 11-cis-retinaldehyde). RESULTS Consistent with previous reports, diabetes significantly reduced (1) dark-adapted rod photo responses (transretinal recording) by ∼18%, (2) rod-dominated light-stimulated SRS expansion (ADC MRI) by ∼21%, and (3) cone-dominated contrast sensitivity (using optokinetic tracking [OKT]) by ∼30%. Both 11-cis-retinaldehyde and 9-cis-retinaldehyde largely corrected these metrics of photoreceptor dysfunction. Higher-than-normal retinal superoxide production in diabetes by ∼55% was also significantly corrected following treatment with 11-cis-retinaldehyde, 9-cis-retinaldehyde, or all-trans-retinaldehyde. CONCLUSIONS Collectively, data suggest that retinaldehydes improve photoreceptor dysfunction in diabetic mice, independent of the visual cycle, via an antioxidant mechanism.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Timothy S. Kern
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
| | - David Bissig
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Priya Patel
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Ankit Bhatia
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
| | - Vladimir J. Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology Wayne State University School of Medicine, Detroit, Michigan, United States
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Saliba A, Du Y, Liu H, Patel S, Roberts R, Berkowitz BA, Kern TS. Photobiomodulation Mitigates Diabetes-Induced Retinopathy by Direct and Indirect Mechanisms: Evidence from Intervention Studies in Pigmented Mice. PLoS One 2015; 10:e0139003. [PMID: 26426815 PMCID: PMC4591336 DOI: 10.1371/journal.pone.0139003] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2022] Open
Abstract
Objective Daily application of far-red light from the onset of diabetes mitigated diabetes-induced abnormalities in retinas of albino rats. Here, we test the hypothesis that photobiomodulation (PBM) is effective in diabetic, pigmented mice, even when delayed until weeks after onset of diabetes. Direct and indirect effects of PBM on the retina also were studied. Methods Diabetes was induced in C57Bl/6J mice using streptozotocin. Some diabetics were exposed to PBM therapy (4 min/day; 670 nm) daily. In one study, mice were diabetic for 4 weeks before initiation of PBM for an additional 10 weeks. Retinal oxidative stress, inflammation, and retinal function were measured. In some mice, heads were covered with a lead shield during PBM to prevent direct illumination of the eye, or animals were treated with an inhibitor of heme oxygenase-1. In a second study, PBM was initiated immediately after onset of diabetes, and administered daily for 2 months. These mice were examined using manganese-enhanced MRI to assess effects of PBM on transretinal calcium channel function in vivo. Results PBM intervention improved diabetes-induced changes in superoxide generation, leukostasis, expression of ICAM-1, and visual performance. PBM acted in part remotely from the retina because the beneficial effects were achieved even with the head shielded from the light therapy, and because leukocyte-mediated cytotoxicity of retinal endothelial cells was less in diabetics treated with PBM. SnPP+PBM significantly reduced iNOS expression compared to PBM alone, but significantly exacerbated leukostasis. In study 2, PBM largely mitigated diabetes-induced retinal calcium channel dysfunction in all retinal layers. Conclusions PBM induces retinal protection against abnormalities induced by diabetes in pigmented animals, and even as an intervention. Beneficial effects on the retina likely are mediated by both direct and indirect mechanisms. PBM is a novel non-pharmacologic treatment strategy to inhibit early changes of diabetic retinopathy.
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Affiliation(s)
- Alexandra Saliba
- Case Western Reserve University, Cleveland, Ohio, United States of America
- Catholic University of Brasilia, Brasilia, Brazil
| | - Yunpeng Du
- Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Haitao Liu
- Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Shyam Patel
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
| | - Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States of America
- Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States of America
| | - Timothy S. Kern
- Case Western Reserve University, Cleveland, Ohio, United States of America
- Cleveland Veteran’s Affairs Medical Center, Research Service 151, Cleveland, Ohio, United States of America
- * E-mail:
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Berkowitz BA, Bissig D, Roberts R. MRI of rod cell compartment-specific function in disease and treatment in vivo. Prog Retin Eye Res 2015; 51:90-106. [PMID: 26344734 DOI: 10.1016/j.preteyeres.2015.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 08/26/2015] [Accepted: 09/01/2015] [Indexed: 10/23/2022]
Abstract
Rod cell oxidative stress is a major pathogenic factor in retinal disease, such as diabetic retinopathy (DR) and retinitis pigmentosa (RP). Personalized, non-destructive, and targeted treatment for these diseases remains elusive since current imaging methods cannot analytically measure treatment efficacy against rod cell compartment-specific oxidative stress in vivo. Over the last decade, novel MRI-based approaches that address this technology gap have been developed. This review summarizes progress in the development of MRI since 2006 that enables earlier evaluation of the impact of disease on rod cell compartment-specific function and the efficacy of anti-oxidant treatment than is currently possible with other methods. Most of the new assays of rod cell compartment-specific function are based on endogenous contrast mechanisms, and this is expected to facilitate their translation into patients with DR and RP, and other oxidative stress-based retinal diseases.
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Affiliation(s)
- Bruce A Berkowitz
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA; Dept. Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - David Bissig
- Dept. of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robin Roberts
- Dept. Of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
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Berkowitz BA, Grady EM, Khetarpal N, Patel A, Roberts R. Oxidative stress and light-evoked responses of the posterior segment in a mouse model of diabetic retinopathy. Invest Ophthalmol Vis Sci 2015; 56:606-15. [PMID: 25574049 PMCID: PMC4309313 DOI: 10.1167/iovs.14-15687] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [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: 09/16/2014] [Accepted: 12/12/2014] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To test the hypothesis that in a mouse model of diabetic retinopathy, oxidative stress is linked with impaired light-evoked expansion of choroidal thickness and subretinal space (SRS). METHODS We examined nondiabetic mice (wild-type, wt) with and without administration of manganese, nondiabetic mice deficient in rod phototransduction (transducin alpha knockout; GNAT1(-/-)), and diabetic mice (untreated or treated with the antioxidant α-lipoic acid [LPA]). Magnetic resonance imaging (MRI) was used to measure light-evoked increases in choroidal thickness and the apparent diffusion coefficient (ADC) at 88% to 100% depth into the retina (i.e., the SRS layer). RESULTS Choroidal thickness values were similar (P > 0.05) between all untreated nondiabetic dark-adapted groups and increased significantly (P < 0.05) with light; this expansion was subnormal (P < 0.05) in both diabetic groups. Apparent diffusion coefficient values in the SRS layer robustly increased (P < 0.05) in a light duration-dependent manner, and this effect was independent of the presence of Mn(2+). The light-stimulated increase in ADC at the location of the SRS was absent in GNAT1(-/-) and diabetic mice (P > 0.05). In diabetic mice, the light-dependent increase in SRS ADC was significantly (P < 0.05) restored with LPA. CONCLUSIONS Apparent diffusion coefficient MRI is a sensitive method for evaluating choroid thickness and its light-evoked expansion together with phototransduction-dependent changes in the SRS layer in mice in vivo. Because ADC MRI exploits an endogenous contrast mechanism, its translational potential is promising; it can also be performed in concert with manganese-enhanced MRI (MEMRI). Our data support a link between diabetes-related oxidative stress and rod, but not choroidal, pathophysiology.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
- Department of Ophthalmology, Wayne State University, Detroit, Michigan, United States
| | - Edmund Michael Grady
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Nikita Khetarpal
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Akshar Patel
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, Michigan, United States
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Abstract
Although photoreceptors account for most of the mass and metabolic activity of the retina, their role in the pathogenesis of diabetic retinopathy has been largely overlooked. Recent studies suggest that photoreceptors might play a critical role in the diabetes-induced degeneration of retinal capillaries, and thus can no longer be ignored. The present review summarizes diabetes-induced alterations in photoreceptor structure and function, and provides a rationale for further study of a role of photoreceptors in the pathogenesis of the retinopathy.
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Affiliation(s)
- Timothy S Kern
- Case Western Reserve University, Department of Medicine and Center for Diabetes Research Cleveland, Ohio, USA ; Veterans Administration Medical Center Research Service 151 Cleveland, Ohio, USA
| | - Bruce A Berkowitz
- Wayne State University School of Medicine, Departments of Anatomy and Cell Biology and Ophthalmology Detroit, Michigan, USA
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Berkowitz BA, Gorgis J, Patel A, Baameur F, Gurevich VV, Craft CM, Kefalov VJ, Roberts R. Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light-evoked translocation in vivo. FASEB J 2014; 29:554-64. [PMID: 25351983 DOI: 10.1096/fj.14-254953] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Rod tetrameric arrestin 1 (tet-ARR1), stored in the outer nuclear layer/inner segments in the dark, modulates photoreceptor synaptic activity; light exposure stimulates a reduction via translocation to the outer segments for terminating G-protein coupled phototransduction signaling. Here, we test the hypothesis that intraretinal spin-lattice relaxation rate in the rotating frame (1/T1ρ), an endogenous MRI contrast mechanism, has high potential for evaluating rod tet-ARR1 and its reduction via translocation. Dark- and light-exposed mice (null for the ARR1 gene, overexpressing ARR1, diabetic, or wild type with or without treatment with Mn2+, a calcium channel probe) were studied using 1/T1ρ MRI. Immunohistochemistry and single-cell recordings of the retinas were also performed. In wild-type mice with or without treatment with Mn2+, 1/T1ρ of avascular outer retina (64% to 72% depth) was significantly (P < 0.05) greater in the dark than in the light; a significant (P < 0.05) but opposite pattern was noted in the inner retina (<50% depth). Light-evoked outer retina Δ1/T1ρ was absent in ARR1-null mice and supernormal in overexpressing mice. In diabetic mice, the outer retinal Δ1/T1ρ pattern suggested normal dark-to-light tet-ARR1 translocation and chromophore content, conclusions confirmed ex vivo. Light-stimulated Δ1/T1ρ in inner retina was linked to changes in blood volume. Our data support 1/T1ρ MRI for noninvasively assessing rod tet-ARR1 and its reduction via protein translocation, which can be combined with other metrics of retinal function in vivo.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology and Department of Ophthalmology, Wayne State University, Detroit, Michigan, USA;
| | | | | | - Faiza Baameur
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, Tennessee, USA
| | - Cheryl M Craft
- Mary D. Allen Laboratory for Vision Research, USC Eye Institute, and Department of Ophthalmology and Department of Cell and Neurobiology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA; and
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
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Berkowitz BA, Grady EM, Roberts R. Confirming a prediction of the calcium hypothesis of photoreceptor aging in mice. Neurobiol Aging 2014; 35:1883-91. [PMID: 24680323 DOI: 10.1016/j.neurobiolaging.2014.02.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 02/14/2014] [Accepted: 02/26/2014] [Indexed: 12/01/2022]
Abstract
Prior work in healthy rats supported a calcium hypothesis of photoreceptor aging, wherein progressive age-related declines in photopic vision are explainable by the extent of earlier escalating d-cis-diltiazem-insensitive increases in photoreceptor L-type calcium channel (LTCC) activity in vivo. Unlike rats, healthy mice have relatively stable photopic vision until after 18 months of age. We therefore hypothesized that photoreceptor LTCC activity in mice would not progressively increase until after 18 months. In 2-5, 10, 18, and 26 months male C57Bl/6J mice, photoreceptor LTCC activity and retinal thickness were evaluated in vivo (manganese-enhanced magnetic resonance imaging) with some groups also treated with d-cis-diltiazem; visual performance was evaluated (optokinetic tracking). Data were calibrated for cone-only responses using mice without rod transducin (GNAT1-/-). Photopic vision was stable until after 18 months without retinal thinning or progressive increases in retinal manganese uptake. We measured an uptake spike at 10 months. This spike, unlike that in the rat, was diltiazem sensitive in the dark and diltiazem insensitive in the light. Between dark and light, uptake in inner retina of older mice was unequal (unlike that in 2-5 months mice); outer retinal uptake was similar to that in 2-5 months mice. Stable murine photopic visual performance and nonescalating photoreceptor LTCC activity before 18 months of age were consistent with a prediction of the calcium hypothesis. Stark differences in the temporal evolution of mouse and rat photoreceptor LTCC activity suggest the need for personalized identification of the retinal mechanisms contributing to declines in photopic vision to ensure success of future treatment efforts.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
| | - Edmund Michael Grady
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Robin Roberts
- Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA
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Bissig D, Berkowitz BA. Testing the calcium hypothesis of aging in the rat hippocampus in vivo using manganese-enhanced MRI. Neurobiol Aging 2013; 35:1453-8. [PMID: 24439958 DOI: 10.1016/j.neurobiolaging.2013.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 12/12/2013] [Accepted: 12/19/2013] [Indexed: 11/30/2022]
Abstract
In this study, we noninvasively tested the hypothesis that Mn(2+)-enhanced magnetic resonance imaging (MEMRI) is sensitive to age-related changes in Ca(2+) influx occurring in the hippocampal region CA1. Uptake of Mn(2+), an MRI contrast agent and Ca(2+) surrogate with low cellular efflux rates (days to weeks), was measured in longitudinal MEMRI studies involving 2 separate groups of male Long-Evans rats: one group was studied at 2.5 and 7 months of age, whereas the other was studied at 7 and 19 months of age. Separate or combined analysis revealed that the extent of Mn(2+) accumulation in CA1 significantly increased with age (p < 0.05). These results provide first-time in vivo confirmation of the calcium hypothesis of aging and justify future longitudinal studies combining MEMRI with behavioral testing to investigate mechanisms of age-related cognitive decline.
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Affiliation(s)
- David Bissig
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, USA; Department of Ophthalmology, Wayne State University School of Medicine, Detroit, MI, USA.
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Berkowitz BA, Bissig D, Dutczak O, Corbett S, North R, Roberts R. MRI biomarkers for evaluation of treatment efficacy in preclinical diabetic retinopathy. ACTA ACUST UNITED AC 2013; 7:393-403. [PMID: 23786440 DOI: 10.1517/17530059.2013.814639] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
INTRODUCTION One sober consequence of the current epidemic of diabetes mellitus is that an increasing number of people world-wide will partially or completely lose their sight to diabetic retinopathy. Clinically, the sight-threatening complications of diabetes are diagnosed and treated based on visible retinal lesions (e.g., dot-blot hemorrhages or retinal neovascularization). However, such anatomical microvascular lesions are slow to respond with treatment. Thus, there remains an urgent need for imaging biomarkers that are abnormal before retinal lesions are visibly apparent and are responsive to treatment. AREAS COVERED Here, the development of new MRI methods, such as manganese-enhanced MRI, for evaluating early diabetes-evoked retinal pathophysiology, and its usefulness in guiding new treatments for diabetic retinopathy are reviewed. EXPERT OPINION In diabetic retinopathy, not all important diagnostic and prognostic needs are well served by optical methods. In the absence of gross anatomy changes, critical times when drug intervention is most likely to be successful at reducing vision loss are missed by most light-based methods and thus provide little help in guiding diagnosis and treatment. For example, before clinical symptoms, is there an optimal time to intervene with drug therapy? Is a drug reaching its target? How does one assess optimal drug dose, schedule, and routes? How well do current experimental models mimic the clinical condition? As discussed herein, MRI is as an analytical tool for addressing these unmet needs. Future clinical applications of MRI can be envisioned such as in clinical trials to assess drug treatment efficacy, or as an adjunct approach to refine or clarify a difficult clinical case. New MRI-generated hypotheses about the pathogenesis of diabetic retinopathy and its treatment are discussed. In the coming years, a substantial growth in the development and application of MRI is expected to address relevant question in both the basic sciences and in the clinic.
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Affiliation(s)
- Bruce A Berkowitz
- Wayne State University, Department of Anatomy and Cell Biology, Detroit, MI, USA.
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Bissig D, Berkowitz BA. Light-dependent changes in outer retinal water diffusion in rats in vivo. Mol Vis 2012; 18:2561-xxx. [PMID: 23129976 PMCID: PMC3482170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 10/18/2012] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To test the hypothesis that in rats, intraretinal light-dependent changes on diffusion-weighted magnetic resonance imaging (MRI) in vivo are consistent with known retinal layer-specific physiology. METHODS In male Sprague-Dawley rats, retinal morphology (thickness, extent, surface area, volume) and intraretinal profiles of the apparent diffusion coefficient (ADC, i.e., water mobility) parallel and perpendicular to the optic nerve were measured in vivo using quantitative MRI methods during light and dark stimulation. RESULTS The parallel ADC in the posterior half of the avascular, photoreceptor-dominated outer retina was significantly higher in light than dark, and this pattern was reversed (dark>light) in the anterior outer retina. The perpendicular ADC in the posterior outer retina was similar in light and dark, but was significantly higher in dark than light in the anterior outer retina. No light-dark changes in the inner retina were noted. CONCLUSIONS We identified light-dependent intraretinal diffusion changes that reflected established stimulation-based changes in outer retinal hydration. These findings are expected to motivate future applications of functional diffusion-based MRI in blinding disorders of the outer retina.
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Affiliation(s)
- David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI,Department of Ophthalmology, Wayne State University, Detroit, MI
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Li X, McClellan ME, Tanito M, Garteiser P, Towner R, Bissig D, Berkowitz BA, Fliesler SJ, Woodruff ML, Fain GL, Birch DG, Khan MS, Ash JD, Elliott MH. Loss of caveolin-1 impairs retinal function due to disturbance of subretinal microenvironment. J Biol Chem 2012; 287:16424-34. [PMID: 22451674 DOI: 10.1074/jbc.m112.353763] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Caveolin-1 (Cav-1), an integral component of caveolar membrane domains, is expressed in several retinal cell types, including photoreceptors, retinal vascular endothelial cells, Müller glia, and retinal pigment epithelium (RPE) cells. Recent evidence links Cav-1 to ocular diseases, including autoimmune uveitis, diabetic retinopathy, and primary open angle glaucoma, but its role in normal vision is largely undetermined. In this report, we show that ablation of Cav-1 results in reduced inner and outer retinal function as measured, in vivo, by electroretinography and manganese-enhanced MRI. Somewhat surprisingly, dark current and light sensitivity were normal in individual rods (recorded with suction electrode methods) from Cav-1 knock-out (KO) mice. Although photoreceptor function was largely normal, in vitro, the apparent K(+) affinity of the RPE-expressed α1-Na(+)/K(+)-ATPase was decreased in Cav-1 KO mice. Cav-1 KO retinas also displayed unusually tight adhesion with the RPE, which could be resolved by brief treatment with hyperosmotic medium, suggesting alterations in outer retinal fluid homeostasis. Collectively, these findings demonstrate that reduced retinal function resulting from Cav-1 ablation is not photoreceptor-intrinsic but rather involves impaired subretinal and/or RPE ion/fluid homeostasis.
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Affiliation(s)
- Xiaoman Li
- Department of Ophthalmology and Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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Braun RD, Bissig D, North R, Vistisen KS, Berkowitz BA. Human tumor cell proliferation evaluated using manganese-enhanced MRI. PLoS One 2012; 7:e30572. [PMID: 22363447 PMCID: PMC3281834 DOI: 10.1371/journal.pone.0030572] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 12/22/2011] [Indexed: 12/28/2022] Open
Abstract
Background Tumor cell proliferation can depend on calcium entry across the cell membrane. As a first step toward the development of a non-invasive test of the extent of tumor cell proliferation in vivo, we tested the hypothesis that tumor cell uptake of a calcium surrogate, Mn2+ [measured with manganese-enhanced MRI (MEMRI)], is linked to proliferation rate in vitro. Methodology/Principal Findings Proliferation rates were determined in vitro in three different human tumor cell lines: C918 and OCM-1 human uveal melanomas and PC-3 prostate carcinoma. Cells growing at different average proliferation rates were exposed to 1 mM MnCl2 for one hour and then thoroughly washed. MEMRI R1 values (longitudinal relaxation rates), which have a positive linear relationship with Mn2+ concentration, were then determined from cell pellets. Cell cycle distributions were determined using propidium iodide staining and flow cytometry. All three lines showed Mn2+-induced increases in R1 compared to cells not exposed to Mn2+. C918 and PC-3 cells each showed a significant, positive correlation between MEMRI R1 values and proliferation rate (p≤0.005), while OCM-1 cells showed no significant correlation. Preliminary, general modeling of these positive relationships suggested that pellet R1 for the PC-3 cells, but not for the C918 cells, could be adequately described by simply accounting for changes in the distribution of the cell cycle-dependent subpopulations in the pellet. Conclusions/Significance These data clearly demonstrate the tumor-cell dependent nature of the relationship between proliferation and calcium influx, and underscore the usefulness of MEMRI as a non-invasive method for investigating this link. MEMRI is applicable to study tumors in vivo, and the present results raise the possibility of evaluating proliferation parameters of some tumor types in vivo using MEMRI.
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Affiliation(s)
- Rod D Braun
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America.
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Berkowitz BA, Bissig D, Patel P, Bhatia A, Roberts R. Acute systemic 11-cis-retinal intervention improves abnormal outer retinal ion channel closure in diabetic mice. Mol Vis 2012; 18:372-6. [PMID: 22355248 PMCID: PMC3283205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 02/02/2012] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To test the hypothesis that in dark-adapted diabetic mice subnormal manganese uptake in the outer retina can be ameliorated with exogenous 11-cis-retinal intervention. METHODS Three groups were studied: age-matched controls and mice that had been diabetic for 3 months with and without acute, systemic 11-cis-retinal treatment administered 30 min before the manganese injection. Mice in each group were examined with manganese-enhanced magnetic resonance imaging (MEMRI) to assess central intraretinal manganese uptake and extraocular muscle manganese uptake. Bodyweights and glycated hemoglobin were determined. RESULTS Both diabetic groups had lower bodyweights and higher glycated hemoglobin levels relative to controls; no differences in these parameters between diabetic groups were noted. No substantial differences in muscle uptake were noted between any of the groups. Diabetes produced a subnormal intraretinal uptake of manganese; acute exogenous 11-cis-retinal significantly corrected only outer retinal uptake, although not to control levels. CONCLUSIONS The present results provide for the first time evidence that raises the possibility of a critical role of 11-cis-retinal, a key participant of the visual cycle, in diabetes-evoked outer retinal dysfunction.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI,Department of Ophthalmology, Wayne State University, Detroit, MI
| | - David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Priya Patel
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Ankit Bhatia
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
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Berkowitz BA, Bissig D, Ye Y, Valsadia P, Kern TS, Roberts R. Evidence for diffuse central retinal edema in vivo in diabetic male Sprague Dawley rats. PLoS One 2012; 7:e29619. [PMID: 22253747 PMCID: PMC3256169 DOI: 10.1371/journal.pone.0029619] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 12/01/2011] [Indexed: 12/27/2022] Open
Abstract
Background Investigations into the mechanism of diffuse retinal edema in diabetic subjects have been limited by a lack of animal models and techniques that co-localized retinal thickness and hydration in vivo. In this study we test the hypothesis that a previously reported supernormal central retinal thickness on MRI measured in experimental diabetic retinopathy in vivo represents a persistent and diffuse edema. Methodology/Principal Findings In diabetic and age-matched control rats, and in rats experiencing dilutional hyponatremia (as a positive edema control), whole central retinal thickness, intraretinal water content and apparent diffusion coefficients (ADC, ‘water mobility’) were measured in vivo using quantitative MRI methods. Glycated hemoglobin and retinal thickness ex vivo (histology) were also measured in control and diabetic groups. In the dilutional hyponatremia model, central retinal thickness and water content were supernormal by quantitative MRI, and intraretinal water mobility profiles changed in a manner consistent with intracellular edema. Groups of diabetic (2, 3, 4, 6, and 9 mo of diabetes), and age-matched controls were then investigated with MRI and all diabetic rats showed supernormal whole central retinal thickness. In a separate study in 4 mo diabetic rats (and controls), MRI retinal thickness and water content metrics were significantly greater than normal, and ADC was subnormal in the outer retina; the increase in retinal thickness was not detected histologically on sections of fixed and dehydrated retinas from these rats. Conclusions/Significance Diabetic male Sprague Dawley rats demonstrate a persistent and diffuse retinal edema in vivo, providing, for the first time, an important model for investigating its pathogenesis and treatment. These studies also validate MRI as a powerful approach for investigating mechanisms of diabetic retinal edema in future experimental and clinical investigations.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, United States of America.
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Berkowitz BA, Bissig D, Bergman D, Bercea E, Kasturi VK, Roberts R. Intraretinal calcium channels and retinal morbidity in experimental retinopathy of prematurity. Mol Vis 2011; 17:2516-26. [PMID: 21976962 PMCID: PMC3185031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 09/22/2011] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To test the hypothesis that intraretinal calcium channels participate in retinal morbidity in a variable oxygen (VO) model of retinopathy of prematurity. METHODS In control and VO Long Evans (LE) rats, either untreated or treated with voltage- or ligand-gated calcium channel antagonists, we measured retinal neovascular (NV) incidence and severity (adenosine diphosphatase staining), and retinal thickness and intraretinal ion channel activity (manganese-enhanced magnetic resonance imaging). Comparisons with the commonly studied Sprague Dawley rats were performed. Visual performance (optokinetic tracking) in untreated VO LE rats was also evaluated. RESULTS In control LE rats, specific L-type voltage calcium channel antagonism, but not ligand-gated channel blockers, suppressed retinal manganese accumulation, while the inhibition of L-type channels normalized intraretinal uptake in VO LE rats. VO LE rats developed more severe NV than VO Sprague Dawley rats. Following VO, both strains demonstrated significant and similar degrees of retinal thinning and supernormal intraretinal manganese uptake. However, over time, intraretinal uptake remained elevated only in VO LE rats. Visual performance was subnormal in VO LE rats. L-type voltage-gated calcium channel antagonism reduced NV severity by 28% (p<0.05) in experimental LE rats compared to that in the control group. CONCLUSIONS Abnormal intraretinal calcium channel activity is linked with retinal morbidity in experimental retinopathy of prematurity.
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Affiliation(s)
- Bruce A. Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI,Department of Ophthalmology, Wayne State University, Detroit, MI
| | - David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Deborah Bergman
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Emanuela Bercea
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Vijaya K. Kasturi
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI
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Bissig D, Berkowitz BA. Same-session functional assessment of rat retina and brain with manganese-enhanced MRI. Neuroimage 2011; 58:749-60. [PMID: 21749922 DOI: 10.1016/j.neuroimage.2011.06.062] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 06/09/2011] [Accepted: 06/24/2011] [Indexed: 11/27/2022] Open
Abstract
Manganese-enhanced MRI (MEMRI) is a powerful non-invasive approach for objectively measuring either retina or binocular visual brain activity in vivo. In this study, we investigated the sensitivity of MEMRI to monocular stimulation using a new protocol for providing within-subject functional comparisons in the retina and brain in the same scanning session. Adult Sprague Dawley or Long-Evans rats had one eye covered with an opaque patch. After intraperitoneal Mn(2+) administration on the following day, rats underwent visual stimulation for 8h. Animals were then anesthetized, and the brain and each eye examined by MEMRI. Function was assessed through pairwise comparisons of the patched (dark-adapted) versus unpatched (light-exposed) eyes, and of differentially-stimulated brain structures - the dorsal lateral geniculate nucleus, superior colliculus, and visual cortical regions - contralateral to the patched versus unpatched eye. As expected, Mn(2+) uptake was greater in the outer retina of dark-adapted, relative to light-exposed, eyes (P<0.05). Contralateral to the unpatched eye, significantly more Mn(2+) uptake was found throughout the visual brain regions than in the corresponding structures contralateral to the patched eye (P<0.05). Notably, this regional pattern of activity corresponded well to previous work with monocular stimulation. No stimulation-dependent differences in Mn(2+) uptake were observed in negative control brain regions (P>0.05). Post-hoc assessment of functional data by animal age and strain revealed no significant effects. These results demonstrate, for the first time, the acquisition of functional MRI data from the eye and visual brain regions in a single scanning session.
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Affiliation(s)
- David Bissig
- Department of Anatomy and Cell Biology, Wayne State University, Detroit, MI 48201, USA
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