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Zaydon YA, Tsang SH. The ABCs of Stargardt disease: the latest advances in precision medicine. Cell Biosci 2024; 14:98. [PMID: 39060921 PMCID: PMC11282698 DOI: 10.1186/s13578-024-01272-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Accepted: 07/01/2024] [Indexed: 07/28/2024] Open
Abstract
Stargardt disease (STGD) is the most common form of inherited juvenile macular dystrophy and is caused by sequence variants in the ABCA4 gene. Due to its genetic complexity and phenotypic variability, STGD poses significant therapeutic challenges. In the past decade, a lot of progress has been made regarding our understanding of the molecular and clinical aspects of STGD, along with its mechanisms. This has led to the development of new therapies, and there are human clinical trials currently ongoing. This paper evaluates the emergence of pharmacological approaches targeting the visual cycle to mitigate retinal damage, the role of gene therapy in correcting specific genetic defects, and the use of stem cell therapies aimed at retinal regeneration by showcasing the latest clinical trials and precision medicine approaches.
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Affiliation(s)
- Yasmine A Zaydon
- Departments of Ophthalmology, Pathology and Cell Biology, Jonas Children's Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
| | - Stephen H Tsang
- Departments of Ophthalmology, Pathology and Cell Biology, Jonas Children's Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
- Department of Pathology and Cell Biology, The Herbert Irving Comprehensive Cancer Center, Institute of Human Nutrition, Columbia University, New York, NY, USA
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Campbell JM, Gosnell M, Agha A, Handley S, Knab A, Anwer AG, Bhargava A, Goldys EM. Label-Free Assessment of Key Biological Autofluorophores: Material Characteristics and Opportunities for Clinical Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403761. [PMID: 38775184 DOI: 10.1002/adma.202403761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/04/2024] [Indexed: 06/13/2024]
Abstract
Autofluorophores are endogenous fluorescent compounds that naturally occur in the intra and extracellular spaces of all tissues and organs. Most have vital biological functions - like the metabolic cofactors NAD(P)H and FAD+, as well as the structural protein collagen. Others are considered to be waste products - like lipofuscin and advanced glycation end products - which accumulate with age and are associated with cellular dysfunction. Due to their natural fluorescence, these materials have great utility for enabling non-invasive, label-free assays with direct ties to biological function. Numerous technologies, with different advantages and drawbacks, are applied to their assessment, including fluorescence lifetime imaging microscopy, hyperspectral microscopy, and flow cytometry. Here, the applications of label-free autofluorophore assessment are reviewed for clinical and health-research applications, with specific attention to biomaterials, disease detection, surgical guidance, treatment monitoring, and tissue assessment - fields that greatly benefit from non-invasive methodologies capable of continuous, in vivo characterization.
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Affiliation(s)
- Jared M Campbell
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | | | - Adnan Agha
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Shannon Handley
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Aline Knab
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Ayad G Anwer
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Akanksha Bhargava
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
| | - Ewa M Goldys
- Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, 2033, Australia
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Różanowska MB. Lipofuscin, Its Origin, Properties, and Contribution to Retinal Fluorescence as a Potential Biomarker of Oxidative Damage to the Retina. Antioxidants (Basel) 2023; 12:2111. [PMID: 38136230 PMCID: PMC10740933 DOI: 10.3390/antiox12122111] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Lipofuscin accumulates with age as intracellular fluorescent granules originating from incomplete lysosomal digestion of phagocytosed and autophagocytosed material. The purpose of this review is to provide an update on the current understanding of the role of oxidative stress and/or lysosomal dysfunction in lipofuscin accumulation and its consequences, particularly for retinal pigment epithelium (RPE). Next, the fluorescence of lipofuscin, spectral changes induced by oxidation, and its contribution to retinal fluorescence are discussed. This is followed by reviewing recent developments in fluorescence imaging of the retina and the current evidence on the prognostic value of retinal fluorescence for the progression of age-related macular degeneration (AMD), the major blinding disease affecting elderly people in developed countries. The evidence of lipofuscin oxidation in vivo and the evidence of increased oxidative damage in AMD retina ex vivo lead to the conclusion that imaging of spectral characteristics of lipofuscin fluorescence may serve as a useful biomarker of oxidative damage, which can be helpful in assessing the efficacy of potential antioxidant therapies in retinal degenerations associated with accumulation of lipofuscin and increased oxidative stress. Finally, amendments to currently used fluorescence imaging instruments are suggested to be more sensitive and specific for imaging spectral characteristics of lipofuscin fluorescence.
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Affiliation(s)
- Małgorzata B. Różanowska
- School of Optometry and Vision Sciences, College of Biomedical and Life Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, Wales, UK;
- Cardiff Institute for Tissue Engineering and Repair (CITER), Redwood Building, King Edward VII Avenue, Cardiff CF10 3NB, Wales, UK
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Vellasamy DM, Lee SJ, Goh KW, Goh BH, Tang YQ, Ming LC, Yap WH. Targeting Immune Senescence in Atherosclerosis. Int J Mol Sci 2022; 23:13059. [PMID: 36361845 PMCID: PMC9658319 DOI: 10.3390/ijms232113059] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 10/29/2023] Open
Abstract
Atherosclerosis is one of the main underlying causes of cardiovascular diseases (CVD). It is associated with chronic inflammation and intimal thickening as well as the involvement of multiple cell types including immune cells. The engagement of innate or adaptive immune response has either athero-protective or atherogenic properties in exacerbating or alleviating atherosclerosis. In atherosclerosis, the mechanism of action of immune cells, particularly monocytes, macrophages, dendritic cells, and B- and T-lymphocytes have been discussed. Immuno-senescence is associated with aging, viral infections, genetic predispositions, and hyperlipidemia, which contribute to atherosclerosis. Immune senescent cells secrete SASP that delays or accelerates atherosclerosis plaque growth and associated pathologies such as aneurysms and coronary artery disease. Senescent cells undergo cell cycle arrest, morphological changes, and phenotypic changes in terms of their abundances and secretome profile including cytokines, chemokines, matrix metalloproteases (MMPs) and Toll-like receptors (TLRs) expressions. The senescence markers are used in therapeutics and currently, senolytics represent one of the emerging treatments where specific targets and clearance of senescent cells are being considered as therapy targets for the prevention or treatment of atherosclerosis.
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Affiliation(s)
- Danusha Michelle Vellasamy
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
| | - Sin-Jye Lee
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
| | - Khang Wen Goh
- Faculty of Data Science and Information Technology, INTI International University, Nilai 71800, Malaysia
| | - Bey-Hing Goh
- Biofunctional Molecule Exploratory (BMEX) Research Group, School of Pharmacy, Monash University Malaysia, Bandar Sunway 47500, Malaysia
- College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, China
| | - Yin-Quan Tang
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
- Centre for Drug Discovery and Molecular Pharmacology, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
| | - Long Chiau Ming
- PAP Rashidah Sa’adatul Bolkiah Institute of Health Sciences, Universiti Brunei Darussalam, Gadong BE1410, Brunei
| | - Wei Hsum Yap
- School of Biosciences, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
- Centre for Drug Discovery and Molecular Pharmacology, Faculty of Medical and Health Sciences, Taylor’s University, Subang Jaya 47500, Malaysia
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The Effect of A2E on the Ca2+-PKC Signaling Pathway in Human RPE Cells Exposed to Blue Light. J Ophthalmol 2022; 2022:2233223. [PMID: 36304713 PMCID: PMC9596233 DOI: 10.1155/2022/2233223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Aims In a model of blue light-induced damage in N-retinylidene-N-retinylethanolamine (A2E)-loaded human retinal pigment epithelial (RPE) cells, we examined the effect of A2E on the calcium (Ca2+)-protein kinase C (PKC) signaling pathway. Methods Primary human RPE cells were cultured, and the cells in the 4th–6th passages were used in this study. The cells were divided into 5 groups: control cells (no A2E, no blue light), blue light-treated cells, blue light + chloroquine-treated cells, blue light + A2E-treated cells, and blue light + A2E + chloroquine-treated cells. The cells were first treated with chloroquine (15 μM for 12 h) and then loaded with A2E (25 μM for 2 h).The blue light intensity was 2000 ± 500 lux, and the duration was 6 h. After blue light exposure, the cells were cultured for 24 h. Fluo-3/AM staining was used to determine the level of cytoplasmic Ca2+, and the cells were photographed using a laser scanning confocal microscope to analyze the fluorescence intensity. The intracellular levels of inositol triphosphate (IP3) and diacylglycerol (DAG) were measured by enzyme-linked immunosorbent assay (ELISA). Intracellular PKC activity was measured with a nonradioactive nuclide assay. Results Among all cell groups, the levels of Ca2+, DAG, and IP3 were lowest in the control cells (P < 0.05). The Ca2+, DAG, and IP3 levels in the blue light + A2E-treated cells and blue light + chloroquine-treated cells were higher than those in the blue light-treated cells (P < 0.05). The Ca2+, DAG, and IP3 levels were highest in the blue light + A2E + chloroquine-treated group (P < 0.05). PKC activity was lowest in the control cells (P < 0.05). The PKC activity of the blue light + A2E-treated cells and blue light + chloroquine-treated cells was higher than that of the blue light-treated cells (P < 0.05), and the PKC activity of the blue light + A2E + chloroquine-treated cells was the highest (P < 0.05). Conclusion Blue light and A2E increased the levels of Ca2+, IP3, and DAG in human RPE cells and enhanced PKC activity, and blue light and A2E had a synergistic effect. Chloroquine further increased the levels of Ca2+, IP3, and DAG and PKC activity in RPE cells or A2E-loaded RPE cells exposed to blue light.
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Sen T, Thummer RP. CRISPR and iPSCs: Recent Developments and Future Perspectives in Neurodegenerative Disease Modelling, Research, and Therapeutics. Neurotox Res 2022; 40:1597-1623. [PMID: 36044181 PMCID: PMC9428373 DOI: 10.1007/s12640-022-00564-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/17/2022] [Accepted: 08/19/2022] [Indexed: 11/15/2022]
Abstract
Neurodegenerative diseases are prominent causes of pain, suffering, and death worldwide. Traditional approaches modelling neurodegenerative diseases are deficient, and therefore, improved strategies that effectively recapitulate the pathophysiological conditions of neurodegenerative diseases are the need of the hour. The generation of human-induced pluripotent stem cells (iPSCs) has transformed our ability to model neurodegenerative diseases in vitro and provide an unlimited source of cells (including desired neuronal cell types) for cell replacement therapy. Recently, CRISPR/Cas9-based genome editing has also been gaining popularity because of the flexibility they provide to generate and ablate disease phenotypes. In addition, the recent advancements in CRISPR/Cas9 technology enables researchers to seamlessly target and introduce precise modifications in the genomic DNA of different human cell lines, including iPSCs. CRISPR-iPSC-based disease modelling, therefore, allows scientists to recapitulate the pathological aspects of most neurodegenerative processes and investigate the role of pathological gene variants in healthy non-patient cell lines. This review outlines how iPSCs, CRISPR/Cas9, and CRISPR-iPSC-based approaches accelerate research on neurodegenerative diseases and take us closer to a cure for neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, Amyotrophic Lateral Sclerosis, and so forth.
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Affiliation(s)
- Tirthankar Sen
- Laboratory for Stem Cell Engineering and Regenerative Medicine, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati - 781039, Assam, India
| | - Rajkumar P Thummer
- Laboratory for Stem Cell Engineering and Regenerative Medicine, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati - 781039, Assam, India.
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Molday RS, Garces FA, Scortecci JF, Molday LL. Structure and function of ABCA4 and its role in the visual cycle and Stargardt macular degeneration. Prog Retin Eye Res 2021; 89:101036. [PMID: 34954332 DOI: 10.1016/j.preteyeres.2021.101036] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/07/2021] [Accepted: 12/13/2021] [Indexed: 12/17/2022]
Abstract
ABCA4 is a member of the superfamily of ATP-binding cassette (ABC) transporters that is preferentially localized along the rim region of rod and cone photoreceptor outer segment disc membranes. It uses the energy from ATP binding and hydrolysis to transport N-retinylidene-phosphatidylethanolamine (N-Ret-PE), the Schiff base adduct of retinal and phosphatidylethanolamine, from the lumen to the cytoplasmic leaflet of disc membranes. This ensures that all-trans-retinal and excess 11-cis-retinal are efficiently cleared from photoreceptor cells thereby preventing the accumulation of toxic retinoid compounds. Loss-of-function mutations in the gene encoding ABCA4 cause autosomal recessive Stargardt macular degeneration, also known as Stargardt disease (STGD1), and related autosomal recessive retinopathies characterized by impaired central vision and an accumulation of lipofuscin and bis-retinoid compounds. High resolution structures of ABCA4 in its substrate and nucleotide free state and containing bound N-Ret-PE or ATP have been determined by cryo-electron microscopy providing insight into the molecular architecture of ABCA4 and mechanisms underlying substrate recognition and conformational changes induced by ATP binding. The expression and functional characterization of a large number of disease-causing missense ABCA4 variants have been determined. These studies have shed light into the molecular mechanisms underlying Stargardt disease and a classification that reliably predicts the effect of a specific missense mutation on the severity of the disease. They also provide a framework for developing rational therapeutic treatments for ABCA4-associated diseases.
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Affiliation(s)
- Robert S Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada; Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, B.C., Canada.
| | - Fabian A Garces
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
| | | | - Laurie L Molday
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, B.C., Canada
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Korac B, Kalezic A, Pekovic-Vaughan V, Korac A, Jankovic A. Redox changes in obesity, metabolic syndrome, and diabetes. Redox Biol 2021; 42:101887. [PMID: 33579666 PMCID: PMC8113039 DOI: 10.1016/j.redox.2021.101887] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
"Life is an instantaneous encounter of circulating matter and flowing energy" (Jean Giaja, Serbian physiologist), is one of the most elegant definitions not only of life but the relationship of redox biology and metabolism. Their evolutionary liaison has created inseparable yet dynamic homeostasis in health, which, when disrupted, leads to disease. This interconnection is even more pertinent today, in an era of increasing metabolic diseases of epidemic proportions such as obesity, metabolic syndrome, and diabetes. Despite great advances in understanding the molecular mechanisms of redox and metabolic regulation, we face significant challenges in preventing, diagnosing, and treating metabolic diseases. The etiological association and temporal overlap of these syndromes present significant challenges for the discrimination of appropriate clinical biomarkers for diagnosis, treatment, and outcome prediction. These multifactorial, multiorgan metabolic syndromes with complex etiopathogenic mechanisms are accompanied by disturbed redox equilibrium in target tissues and circulation. Free radicals and reactive species are considered both a causal factor and a consequence of disease status. Thus, determining the subtypes and levels of free radicals and reactive species, oxidatively damaged biomolecules (lipids, proteins, and nucleic acids) and antioxidant defense components as well as redox-sensitive transcription factors and fluxes of redox-dependent metabolic pathways will help define existing and establish novel redox biomarkers for stratifying metabolic diseases. This review aims to discuss diverse redox/metabolic aspects in obesity, metabolic syndrome, and diabetes, with the imperative to help establish a platform for emerging and future redox-metabolic biomarkers research in precision medicine. Future research warrants detailed investigations into the status of redox biomarkers in healthy subjects and patients, including the use of emerging 'omic' profiling technologies (e.g., redox proteomes, lipidomes, metabolomes, and transcriptomes), taking into account the influence of lifestyle (diet, physical activity, sleep, work patterns) as well as circadian ~24h fluctuations in circulatory factors and metabolites.
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Affiliation(s)
- Bato Korac
- Department of Physiology, Institute for Biological Research "Siniša Stanković"- National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia; Center for Electron Microscopy, Faculty of Biology, University of Belgrade, 11000, Belgrade, Serbia.
| | - Andjelika Kalezic
- Department of Physiology, Institute for Biological Research "Siniša Stanković"- National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Vanja Pekovic-Vaughan
- Institute of Life Course and Medical Sciences, Faculty of Health and Life Sciences, William Henry Duncan Building, University of Liverpool, L7 8TX, Liverpool, UK
| | - Aleksandra Korac
- Center for Electron Microscopy, Faculty of Biology, University of Belgrade, 11000, Belgrade, Serbia
| | - Aleksandra Jankovic
- Department of Physiology, Institute for Biological Research "Siniša Stanković"- National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia.
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Baksheeva VE, Tiulina VV, Tikhomirova NK, Gancharova OS, Komarov SV, Philippov PP, Zamyatnin AA, Senin II, Zernii EY. Suppression of Light-Induced Oxidative Stress in the Retina by Mitochondria-Targeted Antioxidant. Antioxidants (Basel) 2018; 8:E3. [PMID: 30577635 PMCID: PMC6356525 DOI: 10.3390/antiox8010003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 01/06/2023] Open
Abstract
Light-induced oxidation of lipids and proteins provokes retinal injuries and results in progression of degenerative retinal diseases, such as, for instance, iatrogenic photic maculopathies. Having accumulated over years retinal injuries contribute to development of age-related macular degeneration (AMD). Antioxidant treatment is regarded as a promising approach to protecting the retina from light damage and AMD. Here, we examine oxidative processes induced in rabbit retina by excessive light illumination with or without premedication using mitochondria-targeted antioxidant SkQ1 (10-(6'-plastoquinonyl)decyltriphenyl-phosphonium). The retinal extracts obtained from animals euthanized within 1⁻7 days post exposure were analyzed for H₂O₂, malondialdehyde (MDA), total antioxidant activity (AOA), and activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) using colorimetric and luminescence assays. Oxidation of visual arrestin was monitored by immunoblotting. The light exposure induced lipid peroxidation and H₂O₂ accumulation in the retinal cells. Unexpectedly, it prominently upregulated AOA in retinal extracts although SOD and GPx activities were compromised. These alterations were accompanied by accumulation of disulfide dimers of arrestin revealing oxidative stress in the photoreceptors. Premedication of the eyes with SkQ1 accelerated normalization of H₂O₂ levels and redox-status of lipids and proteins, contemporarily enhancing AOA and, likely, sustaining normal activity of GPx. Thus, SkQ1 protects the retina from light-induced oxidative stress and could be employed to suppress oxidative damage of proteins and lipids contributing to AMD.
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Affiliation(s)
- Viktoriia E Baksheeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Veronika V Tiulina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Natalia K Tikhomirova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Olga S Gancharova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Sergey V Komarov
- Department of Biology and Pathology of Domestic, Laboratory and Exotic Animals, Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology, Moscow 109472, Russia.
| | - Pavel P Philippov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Andrey A Zamyatnin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Ivan I Senin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Evgeni Yu Zernii
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
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Moreno-García A, Kun A, Calero O, Medina M, Calero M. An Overview of the Role of Lipofuscin in Age-Related Neurodegeneration. Front Neurosci 2018; 12:464. [PMID: 30026686 PMCID: PMC6041410 DOI: 10.3389/fnins.2018.00464] [Citation(s) in RCA: 211] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 06/18/2018] [Indexed: 12/21/2022] Open
Abstract
Despite aging being by far the greatest risk factor for highly prevalent neurodegenerative disorders, the molecular underpinnings of age-related brain changes are still not well understood, particularly the transition from normal healthy brain aging to neuropathological aging. Aging is an extremely complex, multifactorial process involving the simultaneous interplay of several processes operating at many levels of the functional organization. The buildup of potentially toxic protein aggregates and their spreading through various brain regions has been identified as a major contributor to these pathologies. One of the most striking morphologic changes in neurons during normal aging is the accumulation of lipofuscin (LF) aggregates, as well as, neuromelanin pigments. LF is an autofluorescent lipopigment formed by lipids, metals and misfolded proteins, which is especially abundant in nerve cells, cardiac muscle cells and skin. Within the Central Nervous System (CNS), LF accumulates as aggregates, delineating a specific senescence pattern in both physiological and pathological states, altering neuronal cytoskeleton and cellular trafficking and metabolism, and being associated with neuronal loss, and glial proliferation and activation. Traditionally, the accumulation of LF in the CNS has been considered a secondary consequence of the aging process, being a mere bystander of the pathological buildup associated with different neurodegenerative disorders. Here, we discuss recent evidence suggesting the possibility that LF aggregates may have an active role in neurodegeneration. We argue that LF is a relevant effector of aging that represents a risk factor or driver for neurodegenerative disorders.
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Affiliation(s)
| | - Alejandra Kun
- Biochemistry Section, Science School, Universidad de la República, Montevideo, Uruguay
- Protein and Nucleic Acids Department, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Olga Calero
- Chronic Disease Programme-CROSADIS, Instituto de Salud Carlos III, Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
| | - Miguel Medina
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
- Alzheimer Disease Research Unit, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Madrid, Spain
| | - Miguel Calero
- Chronic Disease Programme-CROSADIS, Instituto de Salud Carlos III, Madrid, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Madrid, Spain
- Alzheimer Disease Research Unit, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Madrid, Spain
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Removal of the blue component of light significantly decreases retinal damage after high intensity exposure. PLoS One 2018; 13:e0194218. [PMID: 29543853 PMCID: PMC5854379 DOI: 10.1371/journal.pone.0194218] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 02/27/2018] [Indexed: 12/14/2022] Open
Abstract
Light causes damage to the retina (phototoxicity) and decreases photoreceptor responses to light. The most harmful component of visible light is the blue wavelength (400–500 nm). Different filters have been tested, but so far all of them allow passing a lot of this wavelength (70%). The aim of this work has been to prove that a filter that removes 94% of the blue component may protect the function and morphology of the retina significantly. Three experimental groups were designed. The first group was unexposed to light, the second one was exposed and the third one was exposed and protected by a blue-blocking filter. Light damage was induced in young albino mice (p30) by exposing them to white light of high intensity (5,000 lux) continuously for 7 days. Short wavelength light filters were used for light protection. The blue component was removed (94%) from the light source by our filter. Electroretinographical recordings were performed before and after light damage. Changes in retinal structure were studied using immunohistochemistry, and TUNEL labeling. Also, cells in the outer nuclear layer were counted and compared among the three different groups. Functional visual responses were significantly more conserved in protected animals (with the blue-blocking filter) than in unprotected animals. Also, retinal structure was better kept and photoreceptor survival was greater in protected animals, these differences were significant in central areas of the retina. Still, functional and morphological responses were significantly lower in protected than in unexposed groups. In conclusion, this blue-blocking filter decreases significantly photoreceptor damage after exposure to high intensity light. Actually, our eyes are exposed for a very long time to high levels of blue light (screens, artificial light LED, neons…). The potential damage caused by blue light can be palliated.
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Lei L, Tzekov R, Li H, McDowell JH, Gao G, Smith WC, Tang S, Kaushal S. Inhibition or Stimulation of Autophagy Affects Early Formation of Lipofuscin-Like Autofluorescence in the Retinal Pigment Epithelium Cell. Int J Mol Sci 2017; 18:ijms18040728. [PMID: 28353645 PMCID: PMC5412314 DOI: 10.3390/ijms18040728] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 03/23/2017] [Accepted: 03/24/2017] [Indexed: 12/22/2022] Open
Abstract
The accumulation of lipofuscin in the retinal pigment epithelium (RPE) is dependent on the effectiveness of photoreceptor outer segment material degradation. This study explored the role of autophagy in the fate of RPE lipofuscin degradation. After seven days of feeding with either native or modified rod outer segments, ARPE-19 cells were treated with enhancers or inhibitors of autophagy and the autofluorescence was detected by fluorescence-activated cell sorting. Supplementation with different types of rod outer segments increased lipofuscin-like autofluorescence (LLAF) after the inhibition of autophagy, while the induction of autophagy (e.g., application of rapamycin) decreased LLAF. The effects of autophagy induction were further confirmed by Western blotting, which showed the conversion of LC3-I to LC3-II, and by immunofluorescence microscopy, which detected the lysosomal activity of the autophagy inducers. We also monitored LLAF after the application of several autophagy inhibitors by RNA-interference and confocal microscopy. The results showed that, in general, the inhibition of the autophagy-related proteins resulted in an increase in LLAF when cells were fed with rod outer segments, which further confirms the effect of autophagy in the fate of RPE lipofuscin degradation. These results emphasize the complex role of autophagy in modulating RPE autofluorescence and confirm the possibility of the pharmacological clearance of RPE lipofuscin by small molecules.
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Affiliation(s)
- Lei Lei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, No.54 South Xianlie Road, Guangzhou 510060, China.
- Department of Ophthalmology, University of Massachusetts Medical School, 381 Plantation Street, Worcester, MA 01605, USA.
| | - Radouil Tzekov
- Department of Ophthalmology, University of Massachusetts Medical School, 381 Plantation Street, Worcester, MA 01605, USA.
- Department of Ophthalmology, University of South Florida, 13127 USF Magnolia Drive, Tampa, FL 33612, USA.
- The Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA.
| | - Huapeng Li
- Gene Therapy Center, University of Massachusetts Medical School, 381 Plantation Street, Worcester, MA 01605, USA.
| | - J Hugh McDowell
- The Department of Ophthalmology, University of Florida Health Science Center, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - Guangping Gao
- Gene Therapy Center, University of Massachusetts Medical School, 381 Plantation Street, Worcester, MA 01605, USA.
| | - W Clay Smith
- The Department of Ophthalmology, University of Florida Health Science Center, 1600 SW Archer Road, Gainesville, FL 32610, USA.
| | - Shibo Tang
- Aier School of Ophthalmology, Central South University, Floor 4, New Century Building, 198# Furong Middle Road, Changsha 410015, China.
| | - Shalesh Kaushal
- Department of Ophthalmology, University of Massachusetts Medical School, 381 Plantation Street, Worcester, MA 01605, USA.
- VRMI, 6205 NW 81st Drive, Gainesville, FL 32653, USA.
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Zhou C, Yu Y, Elston DM. Diagnostic value of eccrine glands and hair follicles in direct immunofluorescent analysis of pemphigus vulgaris and bullous pemphigoid. J Cutan Pathol 2016; 43:334-8. [DOI: 10.1111/cup.12664] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 12/22/2015] [Accepted: 01/06/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Cheng Zhou
- Ackerman Academy of Dermatopathology; New York NY USA
- Department of Dermatology; Peking University People's Hospital; Beijing China
| | - Yan Yu
- Ackerman Academy of Dermatopathology; New York NY USA
- Department of Dermatology; First Hospital of Jilin University; Changchun Jilin China
| | - Dirk M. Elston
- Ackerman Academy of Dermatopathology; New York NY USA
- Department of Dermatology and Dermatologic Surgery; Medical University of South Carolina; Charleston SC USA
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