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Zhang SM, Fan B, Li YL, Zuo ZY, Li GY. Oxidative Stress-Involved Mitophagy of Retinal Pigment Epithelium and Retinal Degenerative Diseases. Cell Mol Neurobiol 2023; 43:3265-3276. [PMID: 37391574 PMCID: PMC10477140 DOI: 10.1007/s10571-023-01383-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/22/2023] [Indexed: 07/02/2023]
Abstract
The retinal pigment epithelium (RPE) is a highly specialized and polarized epithelial cell layer that plays an important role in sustaining the structural and functional integrity of photoreceptors. However, the death of RPE is a common pathological feature in various retinal diseases, especially in age-related macular degeneration (AMD) and diabetic retinopathy (DR). Mitophagy, as a programmed self-degradation of dysfunctional mitochondria, is crucial for maintaining cellular homeostasis and cell survival under stress. RPE contains a high density of mitochondria necessary for it to meet energy demands, so severe stimuli can cause mitochondrial dysfunction and the excess generation of intracellular reactive oxygen species (ROS), which can further trigger oxidative stress-involved mitophagy. In this review, we summarize the classical pathways of oxidative stress-involved mitophagy in RPE and investigate its role in the progression of retinal diseases, aiming to provide a new therapeutic strategy for treating retinal degenerative diseases. The role of mitophagy in AMD and DR. In AMD, excessive ROS production promotes mitophagy in the RPE by activating the Nrf2/p62 pathway, while in DR, ROS may suppress mitophagy by the FOXO3-PINK1/parkin signaling pathway or the TXNIP-mitochondria-lysosome-mediated mitophagy.
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Affiliation(s)
- Si-Ming Zhang
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Bin Fan
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Yu- Lin Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China
| | - Guang-Yu Li
- Department of Ophthalmology, Second Norman Bethune Hospital of Jilin University, Changchun, 130000, China.
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Burgoyne T, Toms M, Way C, Tracey-White D, Futter CE, Moosajee M. Changes in Mitochondrial Size and Morphology in the RPE and Photoreceptors of the Developing and Ageing Zebrafish. Cells 2022; 11:cells11223542. [PMID: 36428971 PMCID: PMC9688747 DOI: 10.3390/cells11223542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/05/2022] [Accepted: 11/04/2022] [Indexed: 11/12/2022] Open
Abstract
Mitochondria are essential adenosine triphosphate (ATP)-generating cellular organelles. In the retina, they are highly numerous in the photoreceptors and retinal pigment epithelium (RPE) due to their high energetic requirements. Fission and fusion of the mitochondria within these cells allow them to adapt to changing demands over the lifespan of the organism. Using transmission electron microscopy, we examined the mitochondrial ultrastructure of zebrafish photoreceptors and RPE from 5 days post fertilisation (dpf) through to late adulthood (3 years). Notably, mitochondria in the youngest animals were large and irregular shaped with a loose cristae architecture, but by 8 dpf they had reduced in size and expanded in number with more defined cristae. Investigation of temporal gene expression of several mitochondrial-related markers indicated fission as the dominant mechanism contributing to the changes observed over time. This is likely to be due to continued mitochondrial stress resulting from the oxidative environment of the retina and prolonged light exposure. We have characterised retinal mitochondrial ageing in a key vertebrate model organism, that provides a basis for future studies of retinal diseases that are linked to mitochondrial dysfunction.
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Affiliation(s)
- Thomas Burgoyne
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Royal Brompton Hospital, Guy’s and St Thomas’ NHS Foundation Trust, London SW3 6NP, UK
| | - Maria Toms
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- The Francis Crick Institute, London NW1 1AT, UK
| | - Chris Way
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Dhani Tracey-White
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Clare E. Futter
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- The Francis Crick Institute, London NW1 1AT, UK
- Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Correspondence:
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Wong JHC, Ma JYW, Jobling AI, Brandli A, Greferath U, Fletcher EL, Vessey KA. Exploring the pathogenesis of age-related macular degeneration: A review of the interplay between retinal pigment epithelium dysfunction and the innate immune system. Front Neurosci 2022; 16:1009599. [PMID: 36408381 PMCID: PMC9670140 DOI: 10.3389/fnins.2022.1009599] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 10/12/2022] [Indexed: 07/30/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss in the older population. Classical hallmarks of early and intermediate AMD are accumulation of drusen, a waste deposit formed under the retina, and pigmentary abnormalities in the retinal pigment epithelium (RPE). When the disease progresses into late AMD, vision is affected due to death of the RPE and the light-sensitive photoreceptors. The RPE is essential to the health of the retina as it forms the outer blood retinal barrier, which establishes ocular immune regulation, and provides support for the photoreceptors. Due to its unique anatomical position, the RPE can communicate with the retinal environment and the systemic immune environment. In AMD, RPE dysfunction and the accumulation of drusen drive the infiltration of retinal and systemic innate immune cells into the outer retina. While recruited endogenous or systemic mononuclear phagocytes (MPs) contribute to the removal of noxious debris, the accumulation of MPs can also result in chronic inflammation and contribute to AMD progression. In addition, direct communication and indirect molecular signaling between MPs and the RPE may promote RPE cell death, choroidal neovascularization and fibrotic scarring that occur in late AMD. In this review, we explore how the RPE and innate immune cells maintain retinal homeostasis, and detail how RPE dysfunction and aberrant immune cell recruitment contribute to AMD pathogenesis. Evidence from AMD patients will be discussed in conjunction with data from preclinical models, to shed light on future therapeutic targets for the treatment of AMD.
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Deletion of the Pedf gene leads to inflammation, photoreceptor loss and vascular disturbances in the retina. Exp Eye Res 2022; 222:109171. [PMID: 35809620 DOI: 10.1016/j.exer.2022.109171] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/25/2022] [Accepted: 06/30/2022] [Indexed: 11/24/2022]
Abstract
Retinal diseases are often accompanied by inflammation, vascular abnormalities, and neurodegeneration that decrease vision. Treatment with exogenous PEDF is widely shown to alleviate these conditions leading us to hypothesize that loss of function of the PEDF gene disrupts these pathways and leads to visual loss. Measurements were carried out by detailed phenotyping of PEDF null mice to assess expression of immunomodulators, glia activation, systemic inflammation, vascular disturbances, and visual sensitivity often associated with retinal pathologies. With a deletion of the Pedf gene, there was increased expression of several immune modulators in Pedf-/- retinas and serum with IL-2 and GM-CSF upregulated in both. Increases in retina glia activation and macrophage infiltration, levels of serum c-reactive protein (CRP), numbers of white and red blood cells and platelets and decreased blood glucose levels were all features associated with PEDF null mice. With PEDF gene deletion, there was also a notable increase in apoptosis in early developing retinas (PN3), reduced thickness of the photoreceptor layer, swelling of the inner plexiform layer, reduced retinal sensitivity and steady-state reduced activation of Erk and Akt, two signaling pathways used by PEDF. There is a substantial body of animal data emphasizing utility of PEDF treatment in homeostatic regulation of retinal diseases, including diabetic retinopathy and age-related macular degeneration but there is little agreement or evidence on the role of endogenous PEDF in retinal diseases. Our findings strongly support the concept that a deletion of the PEDF gene makes the retina vulnerable to diseases, and argue that endogenous PEDF plays a critical role in limiting pathological events in the retina.
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Flores‐Bellver M, Mighty J, Aparicio‐Domingo S, Li KV, Shi C, Zhou J, Cobb H, McGrath P, Michelis G, Lenhart P, Bilousova G, Heissel S, Rudy MJ, Coughlan C, Goodspeed AE, Becerra SP, Redenti S, Canto‐Soler MV. Extracellular vesicles released by human retinal pigment epithelium mediate increased polarised secretion of drusen proteins in response to AMD stressors. J Extracell Vesicles 2021; 10:e12165. [PMID: 34750957 PMCID: PMC8575963 DOI: 10.1002/jev2.12165] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/06/2021] [Accepted: 10/25/2021] [Indexed: 12/22/2022] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. Drusen are key contributors to the etiology of AMD and the ability to modulate drusen biogenesis could lead to therapeutic strategies to slow or halt AMD progression. The mechanisms underlying drusen biogenesis, however, remain mostly unknown. Here we demonstrate that under homeostatic conditions extracellular vesicles (EVs) secreted by retinal pigment epithelium (RPE) cells are enriched in proteins associated with mechanisms involved in AMD pathophysiology, including oxidative stress, immune response, inflammation, complement system and drusen composition. Furthermore, we provide first evidence that drusen-associated proteins are released as cargo of extracellular vesicles secreted by RPE cells in a polarised apical:basal mode. Notably, drusen-associated proteins exhibited distinctive directional secretion modes in homeostatic conditions and, differential modulation of this directional secretion in response to AMD stressors. These observations underpin the existence of a finely-tuned mechanism regulating directional apical:basal sorting and secretion of drusen-associated proteins via EVs, and its modulation in response to mechanisms involved in AMD pathophysiology. Collectively, our results strongly support an active role of RPE-derived EVs as a key source of drusen proteins and important contributors to drusen development and growth.
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Affiliation(s)
- Miguel Flores‐Bellver
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
| | - Jason Mighty
- Lehman CollegeBronxNew YorkUSA
- Biology Doctoral ProgramThe Graduate School and University CenterCity University of New YorkNew YorkNew YorkUSA
| | - Silvia Aparicio‐Domingo
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
| | - Kang V. Li
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
| | - Cui Shi
- Lehman CollegeBronxNew YorkUSA
- Biology Doctoral ProgramThe Graduate School and University CenterCity University of New YorkNew YorkNew YorkUSA
| | | | - Hannah Cobb
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
| | - Patrick McGrath
- Department of DermatologyUniversity of Colorado School of MedicineAuroraColoradoUSA
| | - German Michelis
- Section of Protein Structure and FunctionNEINIHBethesdaMarylandUSA
| | - Patricia Lenhart
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
| | - Ganna Bilousova
- Department of DermatologyUniversity of Colorado School of MedicineAuroraColoradoUSA
- Charles C. Gates Center for Regenerative MedicineUniversity of Colorado School of MedicineAuroraColoradoUSA
- Linda Crnic Institute for Down SyndromeUniversity of Colorado School of MedicineAuroraColoradoUSA
| | - Søren Heissel
- Proteomics Resource CenterThe Rockefeller UniversityNew YorkNew YorkUSA
| | - Michael J. Rudy
- Department of NeurologyUniversity of Colorado School of MedicineAuroraColoradoUSA
| | - Christina Coughlan
- University of Colorado Alzheimer's and Cognition CenterDepartment of NeurologyLinda Crnic Institute for Down SyndromeUniversity of Colorado Anschutz Medical CampusAuroraColoradoUSA
| | - Andrew E. Goodspeed
- Department of PharmacologyUniversity of Colorado Anschutz Medical CampusAuroraColoradoUSA
- University of Colorado Cancer CenterUniversity of Colorado Anschutz Medical CampusAuroraColoradoUSA
| | | | - Stephen Redenti
- Lehman CollegeBronxNew YorkUSA
- Biology Doctoral ProgramThe Graduate School and University CenterCity University of New YorkNew YorkNew YorkUSA
- Biochemistry Doctoral ProgramThe Graduate SchoolCity University of New YorkNew YorkNew YorkUSA
| | - M. Valeria Canto‐Soler
- CellSight Ocular Stem Cell and Regeneration ProgramDepartment of OphthalmologySue Anschutz‐Rodgers Eye CenterUniversity of Colorado, School of MedicineAuroraColoradoUSA
- Charles C. Gates Center for Regenerative MedicineUniversity of Colorado School of MedicineAuroraColoradoUSA
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Hsu ML, Huang WC, Zhou YR, Hu S, Huang CH, Wu SJ. Oleuropein Protects Human Retinal Pigment Epithelium Cells from IL-1β-Induced Inflammation by Blocking MAPK/NF-κB Signaling Pathways. Inflammation 2021; 45:297-307. [PMID: 34613549 DOI: 10.1007/s10753-021-01546-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/27/2021] [Accepted: 08/16/2021] [Indexed: 11/25/2022]
Abstract
Proinflammatory mediators such as interleukin (IL)-1β cause retinal pigment epithelium (RPE) inflammation, which is related to visual deterioration, including age-related macular degeneration and diabetic retinopathy. Oleuropein is a polyphenol compound that shows potent anti-inflammatory, antioxidant, and anti-cancer activities, but its effects on IL-1β-induced inflammation have not been examined in the adult RPE cell line ARPE-19. Here, we assessed the ability of oleuropein to attenuate this inflammation in ARPE-19 cells. IL-1β induced secretion of the inflammatory cytokines IL-6, monocyte chemoattractant protein-1 (MCP)-1, and soluble intercellular adhesion molecule (sICAM)-1. As measured by enzyme-linked immunosorbent assay, oleuropein significantly inhibited levels of all three proteins and led to decreased monocyte adhesiveness to ARPE-19 cells. To clarify the underlying anti-inflammatory mechanisms, we used western blots to evaluate the effect of oleuropein on inactivation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. The results showed that oleuropein significantly decreased levels of the inflammatory mediator cyclooxygenase-2 and increased anti-inflammatory protein HO-1 expression. We next examined if the anti-inflammatory activity of oleuropein arises via inactivated NF-κB. We found that suppressing phosphorylation of the JNK1/2 and p38 MAPK signaling pathways inhibited IL-6, MCP-1, and sICAM-1 secretion, implicating these pathways and NF-κB suppression in the effects of oleuropein. These results indicate that oleuropein shows potential for the prevention and treatment of inflammatory diseases of the retina.
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Affiliation(s)
- Ming-Lung Hsu
- Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Guishan Dist, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd, Taoyuan City, 33303, Taiwan
| | - Wen-Chung Huang
- Graduate Institute of Health Industry Technology, Research Center for Industry of Human Ecology, Research Center for Chinese Herbal Medicine, College of Human Ecology, Guishan Dist, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd, Taoyuan City, 33303, Taiwan
- Division of Allergy, Asthma, and Rheumatology, Department of Pediatrics, Guishan Dist, Chang Gung Memorial Hospital, Linkou, 33303, Taiwan
| | - Yi-Rong Zhou
- Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Guishan Dist, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd, Taoyuan City, 33303, Taiwan
| | - Sindy Hu
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Guishan Dist, Taoyuan, 33303, Taiwan
| | - Chun-Hsun Huang
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Guishan Dist, Taoyuan, 33303, Taiwan.
- Department of Cosmetic Science, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Guishan Dist, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd, Taoyuan City, 33303, Taiwan.
- Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd., Guishan Dist., Taoyuan City, 33303, Taiwan.
| | - Shu-Ju Wu
- Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Guishan Dist, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd, Taoyuan City, 33303, Taiwan.
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Guishan Dist, Taoyuan, 33303, Taiwan.
- Department of Nutrition and Health Sciences, Research Center for Food and Cosmetic Safety, and Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, No.261, Wenhua 1st Rd., Guishan Dist., Taoyuan City, 33303, Taiwan.
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Xu HJ, Li QY, Zou T, Yin ZQ. Development-related mitochondrial properties of retinal pigment epithelium cells derived from hEROs. Int J Ophthalmol 2021; 14:1138-1150. [PMID: 34414076 DOI: 10.18240/ijo.2021.08.02] [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: 02/04/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the temporal mitochondrial characteristics of retinal pigment epithelium (RPE) cells obtained from human embryonic stem cells (hESC)-derived retinal organoids (hEROs-RPE), to verify the optimal period for using hEROs-RPE as donor cells from the aspect of mitochondria and to optimize RPE cell-based therapeutic strategies for age-related macular degeneration (AMD). METHODS RPE cells were obtained from hEROs and from spontaneous differentiation (SD-RPE). The mitochondrial characteristics were analyzed every 20d from day 60 to 160. Mitochondrial quantity was measured by MitoTracker Green staining. Transmission electron microscopy (TEM) was adopted to assess the morphological features of the mitochondria, including their distribution, length, and cristae. Mitochondrial membrane potentials (MMPs) were determined by JC-1 staining and evaluated by flow cytometry, reactive oxygen species (ROS) levels were evaluated by flow cytometry, and adenosine triphosphate (ATP) levels were measured by a luminometer. Differences between two groups were analyzed by the independent-samples t-test, and comparisons among multiple groups were made using one-way ANOVA or Kruskal-Wallis H test when equal variance was not assumed. RESULTS hEROs-RPE and SD-RPE cells from day 60 to 160 were successfully differentiated from hESCs and expressed RPE markers (Pax6, MITF, Bestrophin-1, RPE65, Cralbp). RPE features, including a cobblestone-like morphology with tight junctions (ZO-1), pigments and microvilli, were also observed in both hEROs-RPE and SD-RPE cells. The mitochondrial quantities of hEROs-RPE and SD-RPE cells both peaked at day 80. However, the cristae of hEROs-RPE mitochondria were less mature and abundant than those of SD-RPE mitochondria at day 80, with hEROs-RPE mitochondria becoming mature at day 100. Both hEROs-RPE and SD-RPE cells showed low ROS levels from day 100 to 140 and maintained a normal MMP during this period. However, hEROs-RPE mitochondria maintained a longer time to produce high levels of ATP (from day 120 to 140) than SD-RPE cells (only day 120). CONCLUSION hEROs-RPE mitochondria develop more slowly and maintain a longer time to supply high-level energy than SD-RPE mitochondria. From the mitochondrial perspective, hEROs-RPE cells from day 100 to 140 are an optimal cell source for treating AMD.
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Affiliation(s)
- Hao-Jue Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Qi-You Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Ting Zou
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Zheng-Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
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Schustak J, Twarog M, Wu X, Wu HY, Huang Q, Bao Y. Mechanism of Nucleic Acid Sensing in Retinal Pigment Epithelium (RPE): RIG-I Mediates Type I Interferon Response in Human RPE. J Immunol Res 2021; 2021:9975628. [PMID: 34239945 PMCID: PMC8235977 DOI: 10.1155/2021/9975628] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/12/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022] Open
Abstract
Age-related macular degeneration (AMD), a degenerative disease of the outer retina, is the leading cause of blindness among the elderly. A hallmark of geographic atrophy (GA), an advanced type of nonneovascular AMD (dry AMD), is photoreceptor and retinal pigment epithelium (RPE) cell death. Currently, there are no FDA-approved therapies for GA due to a lack of understanding of the disease-causing mechanisms. Increasing evidence suggests that chronic inflammation plays a predominant role in the pathogenesis of dry AMD. Dead or stressed cells release danger signals and inflammatory factors, which causes further damage to neighboring cells. It has been reported that type I interferon (IFN) response is activated in RPE cells in patients with AMD. However, how RPE cells sense stress to initiate IFN response and cause further damage to the retina are still unknown. Although it has been reported that RPE can respond to extracellularly added dsRNA, it is unknown whether and how RPE detects and senses internally generated or internalized nucleic acids. Here, we elucidated the molecular mechanism by which RPE cells sense intracellular nucleic acids. Our data demonstrate that RPE cells can respond to intracellular RNA and induce type I IFN responses via the RIG-I (DExD/H-box helicase 58, DDX58) RNA helicase. In contrast, we showed that RPE cells were unable to directly sense and respond to DNA through the cGAS-STING pathway. We demonstrated that this was due to the absence of the cyclic GMP-AMP synthase (cGAS) DNA sensor in these cells. The activation of IFN response via RIG-I induced expression of cell death effectors and caused barrier function loss in RPE cells. These data suggested that RPE-intrinsic pathways of nucleic acid sensing are biased toward RNA sensing.
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Affiliation(s)
- Joshua Schustak
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
| | - Michael Twarog
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
| | - Xiaoqiu Wu
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
| | - Henry Y. Wu
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
| | - Qian Huang
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
| | - Yi Bao
- The Department of Ophthalmology, Novartis Institutes for BioMedical Research, 22 Windsor Street, Cambridge, MA, USA
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Yu HJ, Wykoff CC. Investigational Agents in Development for the Treatment of Geographic Atrophy Secondary to Age-Related Macular Degeneration. BioDrugs 2021; 35:303-323. [PMID: 33893984 DOI: 10.1007/s40259-021-00481-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 12/13/2022]
Abstract
Geographic atrophy (GA) is an advanced form of age-related macular degeneration, a late-onset, complex, genetic degenerative disease of the retina. Multiple environmental and genetic factors have been implicated in the development of GA, a pathology ultimately defined by loss of photoreceptors and the underlying retinal pigment epithelium and choriocapillaris. The personal burden of GA has been documented to have a substantial negative impact on quality of life, with progressive and cumulative loss of visual function each year. Currently, there are no treatments to prevent or slow the development or progression of GA. Multiple genetic and histopathologic studies have implicated dysregulation of the complement cascade in GA pathogenesis, leading to the development of several investigational pharmaceuticals targeting key factors in this inflammatory pathway. Several other biochemical pathways have also been implicated in GA development and progression, such as mitochondrial components, mediators of apoptosis and molecules involved in extracellular matrix remodeling, many of which are also being investigated for their potential value as therapeutic targets for GA treatment. Recent advancements in our understanding of GA pathogenesis and the progression of multiple potential therapeutics into later-stage human clinical trials hold great promise for a clinically effective therapeutic for patients with GA to emerge within the near future.
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Affiliation(s)
- Hannah J Yu
- Retina Consultants of Texas, Retina Consultants of America, 4460 Bissonnet St., Suite 200, Bellaire, Texas, 77401, United States
| | - Charles C Wykoff
- Retina Consultants of Texas, Retina Consultants of America, 4460 Bissonnet St., Suite 200, Bellaire, Texas, 77401, United States.
- Blanton Eye Institute, Houston Methodist Hospital, Houston, TX, USA.
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Yako T, Nakamura M, Nakamura S, Hara H, Shimazawa M. Pharmacological inhibition of mitochondrial fission attenuates oxidative stress-induced damage of retinal pigmented epithelial cells. J Pharmacol Sci 2021; 146:149-159. [PMID: 34030797 DOI: 10.1016/j.jphs.2021.03.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 03/15/2021] [Accepted: 04/01/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria maintain their function by the process of mitochondrial dynamics, which involves repeated fusion and fission. It is thought that the failure of mitochondrial dynamics, especially excessive fission, is related to the progression of several diseases. A previous study demonstrated that mitochondrial fragmentation occurs in the retinal pigmented epithelial (RPE) cells of patients with non-exudative age-related macular degeneration (AMD). We predicted that the suppression of mitochondrial fragmentation offers a novel therapeutic strategy for non-exudative AMD. We investigated whether the inhibition of mitochondrial fission was effective against the oxidative stress-induced damage of ARPE-19 cells. The treatment of ARPE-19 cells with H2O2 caused mitochondrial fragmentation, but treatment with mitochondrial division inhibitor 1 (Mdivi-1) suppressed fragmentation. Additionally, Mdivi-1 protected ARPE-19 cells against H2O2-induced damage, and suppressed the release of cytochrome c from the mitochondria. Mitochondrial function was evaluated by staining with JC-1 and measuring the production of reactive oxygen species (ROS), which revealed that mitochondrial function improved in the Mdivi-1-treated group. These findings indicated that the inhibition of mitochondrial fission would be a novel therapeutic target for non-exudative AMD.
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Affiliation(s)
- Tomohiro Yako
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Maho Nakamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Shinsuke Nakamura
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan
| | - Masamitsu Shimazawa
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Gifu, Japan.
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Baek A, Son S, Baek YM, Kim DE. KRT8 (keratin 8) attenuates necrotic cell death by facilitating mitochondrial fission-mediated mitophagy through interaction with PLEC (plectin). Autophagy 2021; 17:3939-3956. [PMID: 33783309 DOI: 10.1080/15548627.2021.1897962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Dysregulation of mitochondrial homeostasis and accumulation of damaged mitochondria cause degenerative diseases such as age-related macular degeneration (AMD). We studied the effects of the intermediate cytofilament KRT8 (keratin 8) on mitochondrial homeostasis in relation to the morphology and function of mitochondria in retinal pigment epithelial cells under oxidative stress. When the mitochondria were damaged owing to oxidative stress, the damaged mitochondria were readily disposed of via mitophagy following mitochondrial fission. During this process, KRT8 was found to physically interact with the mitochondria through PLEC (plectin) and facilitate the mitochondrial fission-mediated mitophagy. However, the association between PLEC-anchoring mitochondria and KRT8 was dwindled by KRT8 phosphorylation under oxidative stress. The efficient KRT8-facilitated mitophagy flux suppressed the accumulation of damaged mitochondria and consequently diminished necrotic cell death under oxidative stress. Thus, by facilitating mitophagy, KRT8 protects RPE cells against necrotic cell death due to oxidative stress.
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Affiliation(s)
- Ahruem Baek
- Department of Bioscience and Biotechnology, Konkuk University, Gwangjin-gu, Republic of Korea
| | - Sumin Son
- Department of Bioscience and Biotechnology, Konkuk University, Gwangjin-gu, Republic of Korea
| | - Yu Mi Baek
- Department of Bioscience and Biotechnology, Konkuk University, Gwangjin-gu, Republic of Korea
| | - Dong-Eun Kim
- Department of Bioscience and Biotechnology, Konkuk University, Gwangjin-gu, Republic of Korea
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Hikage F, Furuhashi M, Ida Y, Ohguro H, Watanabe M, Suzuki S, Itoh K. Fatty acid-binding protein 4 is an independent factor in the pathogenesis of retinal vein occlusion. PLoS One 2021; 16:e0245763. [PMID: 33503066 PMCID: PMC7840053 DOI: 10.1371/journal.pone.0245763] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 01/07/2021] [Indexed: 01/11/2023] Open
Abstract
The main objective of current study was to identify the fatty acid-binding protein 4 (FABP4) expressed in both adipocytes and macrophages in vitreous fluid from patients with retinal vein occlusion (RVO). Patients with RVO (n = 14, CRVO; central RVO n = 5, BRVO; branch RVO n = 9) and non-RVO (macular hole or epiretinal membrane, n = 18) were surgically treated by a 25 or 27G vitrectomy. Undiluted vitreous fluid samples obtained as the result of surgery were subjected to enzyme-linked immunosorbent assays to measure the levels of FABP4 and vascular endothelial growth factor A (VEGFA).Data including ocular blood flow by laser speckle flow graphy (LSFG), height and weight, systemic blood pressures and several blood biochemistry values were collected. Among the LSFG mean blur rate (MBR) values of the optic nerve head (ONH) at baseline, MA (MBR of all area), MV (MBR of the vascular area), and MV-MT (MBR of the tissue area) were significantly decreased in patients with CRVO. The levels of V-FABP4 and V-VEGFA were relatively or significantly (P< 0.05) higher in the BRVO or CRVO patients compared to the non-RVO patients, respectively. A positive correlation (r = 0.36, P = 0.045) or a negative correlation (r = -0.51, P = 0.006) was observed between Log V-FABP4 and Log V-VEGF, or Log V-FABP4 and MV-MT at post-operative 1-week, respectively. Furthermore, neither of these factors were affected with respect to sex, body mass index and several clinical parameters that were collected, except that a positive correlation was observed for Log V-FABP4 with blood urea nitrogen. Stepwise multivariable regression analyses indicated that MV-MT at post-operative 1week was independently associated with Log V-FABP4 after adjustment for age and gender, and gender and Log V-FABP4 were independently associated with Log V-VEGFA after adjustment for age. The findings reported herein suggest that an independent factor, FABP4 may be synergistically involved in the pathogenesis of RVO with VEGFA.
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Affiliation(s)
- Fumihito Hikage
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masato Furuhashi
- Departments of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yosuke Ida
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
- * E-mail:
| | - Hiroshi Ohguro
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Megumi Watanabe
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Soma Suzuki
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Kaku Itoh
- Departments of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
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Beyond AREDS Formulations, What Is Next for Intermediate Age-Related Macular Degeneration (iAMD) Treatment? Potential Benefits of Antioxidant and Anti-inflammatory Apocarotenoids as Neuroprotectors. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4984927. [PMID: 33520083 PMCID: PMC7803142 DOI: 10.1155/2020/4984927] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 10/21/2020] [Accepted: 11/24/2020] [Indexed: 12/12/2022]
Abstract
Age-related macular degeneration (AMD) is the commonest cause of severe visual loss and blindness in developed countries among individuals aged 60 and older. AMD slowly progresses from early AMD to intermediate AMD (iAMD) and ultimately late-stage AMD. Late AMD encompasses either neovascular AMD (nAMD) or geographic atrophy (GA). nAMD is defined by choroidal neovascularization (CNV) and hemorrhage in the subretinal space at the level of the macula. This induces a rapid visual impairment caused by the death of photoreceptor cells. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) antibodies is the standard treatment of nAMD but adds to the burden of patient care. GA is characterized by slowly expanding photoreceptor, and retinal pigment epithelium (RPE) degeneration patches progressively leading to blindness. There is currently no therapy to cure GA. Late AMD continues to be an unmet medical need representing a major health problem with millions of patients worldwide. Oxidative stress and inflammation are recognized as some of the main risk factors to developing late AMD. The antioxidant formulation AREDS (Age-Related Eye Disease Studies), contains β-carotene, which has been replaced by lutein and zeaxanthin in AREDS2, are given to patients with iAMD but have a limited effect on the incidence of nAMD and GA. Thus, to avoid or slowdown the development of late stages of AMD (nAMD or GA), new therapies targeting iAMD are needed such as crocetin obtained through hydrolysis of crocin, an important component of saffron (Crocus sativus L.), and norbixin derived from bixin extracted from Bixa orellana seeds. We have shown that these apocarotenoids preserved more effectively RPE cells against apoptosis following blue light exposure in the presence of A2E than lutein and zeaxanthin. In this review, we will discuss the potential use of apocarotenoids to slowdown the progression of iAMD, to reduce the incidence of both forms of late AMD.
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Pacella E, Loffredo L, Malvasi M, Trovato Battagliola E, Messineo D, Pacella F, Arrico L. Effects of Repeated Intravitreal Injections of Dexamethasone Implants on Intraocular Pressure: A 4-Year Study. Clin Ophthalmol 2020; 14:3611-3617. [PMID: 33154620 PMCID: PMC7605966 DOI: 10.2147/opth.s265691] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/11/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose Dexamethasone and other corticosteroids are administered intravitreally to treat a variety of retinal diseases. As a side effect, they can alter intraocular pressure (IOP). The purpose of this study is to describe the incidence, severity, and management of ocular hypertension following the administration of multiple intravitreal injections of dexamethasone implants. Materials and Methods A total of 78 eyes of 78 subjects (males 62%; females 38%; mean age 67 ± 13 years SD) received a total of 152 intravitreal injections of 0.7 mg dexamethasone implants over 4 years. Indications included retinal vein occlusion (87%), diabetic macular edema (9%), wet-type age-related macular degeneration (4%). Ocular hypertension was defined as intraocular pressure above 23 mmHg or any pressure increase of 10 mmHg or more from baseline values. IOP was measured by applanation tonometry before the injection (T0), as well as one week (T1), one month (T2), and three months (T3) afterwards. Results Five percent (4/78) of subjects developed ocular hypertension after the 1st injection. On the second and third rounds, additional 7.2% (3/42) and 4.2% (1/24) of subjects developed the same side effect. Among the 8 subjects who received a fourth injection, none was found with OHT. Pressure elevations were detected at T2 and T3. In all patients, topical medical therapy was sufficient to lower the IOP below threshold. Mean pressure variations following the first injection as compared to previous recorded values were +0.97 mmHg (T1), +0.92 mmHg (T2), and -0.41 mmHg (T3) (p < 0.05). Mean pressure variations following the second injection were +0.54 mmHg (T1), +0.23 mmHg (T2) and -0.66 mmHg (T3) (p < 0.05). Conclusion Ocular hypertension is a recognized side effect of intravitreal dexamethasone. Some patients develop it right after the first injection, while others develop it subsequently, on the 2nd or 3rd round. This side effect becomes most apparent 30-90 days following the implantation procedure and responds well to topical pressure-lowering medications.
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Affiliation(s)
- Elena Pacella
- Department of Sense Organs, University of Rome La Sapienza, Rome, Italy
| | - Lorenzo Loffredo
- Department of Clinical, Internal Medicine, Anesthesiology and Cardiovascular Sciences, University of Rome La Sapienza, Rome, Italy
| | | | | | - Daniela Messineo
- Department of Radiological, Oncological and Pathological Anatomy Sciences, Sapienza University of Rome, Rome, Italy
| | - Fernanda Pacella
- Department of Sense Organs, University of Rome La Sapienza, Rome, Italy
| | - Loredana Arrico
- Department of Sense Organs, University of Rome La Sapienza, Rome, Italy
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15
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Ibarra DE, Wiebe DE, Mireles T, Pattillo A, Roberts T, Wood TS, Przybylski C, Rodriguez CJ, García DM. A method for quantifying pigment position in retinal pigment epithelium. Exp Eye Res 2020; 195:108038. [PMID: 32333906 DOI: 10.1016/j.exer.2020.108038] [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: 11/07/2019] [Revised: 01/17/2020] [Accepted: 04/07/2020] [Indexed: 10/24/2022]
Abstract
In wildtype mice, the pigment granules in the retinal pigment epithelium aggregate in the dark towards Bruch's membrane and disperse towards the photoreceptors in the light. We have developed a repeatable method amenable for quantifying pigment position in the RPE from wild type mice by estimating the population density of pigment granules, or pigment density, within 4 μm2 areas in the basal part of cells examined by transmission electron microscopy. To measure pigment position, 2 μm × 2 μm squares were aligned along the apical ends of the basal microvilli. The pigment granules within each 4 μm2 area were counted, and the average pigment density was calculated for each mouse. The average pigment density for light-adapted mice (n = 3 mice) was 1.3 pigment granules/μm2 (± 0.2 pigment granules/μm2). For dark-adapted wildtype mice (n = 3 mice), pigment density was 1.9 pigment granules/μm2 (± 0.3 pigment granules/μm2). Pigment density was statistically significantly different (p < 0.02) between light-adapted and dark-adapted mice, with pigment density higher in the dark-adapted mice. This method was implemented by four observers and their results were compared. No statistically significant differences were found in the measurements acquired by the different observers, illustrating the repeatability of the method.
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Affiliation(s)
- Dora Evelyn Ibarra
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Diana E Wiebe
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Thomas Mireles
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Amanda Pattillo
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Tasha Roberts
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Tiffany S Wood
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Connor Przybylski
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Cody J Rodriguez
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
| | - Dana M García
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX, 78666, USA.
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16
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Khaltourina D, Matveyev Y, Alekseev A, Cortese F, Ioviţă A. Aging Fits the Disease Criteria of the International Classification of Diseases. Mech Ageing Dev 2020; 189:111230. [PMID: 32251691 DOI: 10.1016/j.mad.2020.111230] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/04/2020] [Accepted: 03/09/2020] [Indexed: 12/24/2022]
Abstract
The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.
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Affiliation(s)
- Daria Khaltourina
- Department of Risk Factor Prevention, Federal Research Institute for Health Organization and Informatics of Ministry of Health of the Russian Federation, Dobrolyubova St. 11, Moscow, 127254, Russia; International Longevity Alliance, 19 avenue Jean Jaurès, Sceaux, 92330, France.
| | - Yuri Matveyev
- Research Lab, Moscow Regional Research and Clinical Institute, Schepkina St. 61/2 k.1, Moscow, 129110, Russia
| | - Aleksey Alekseev
- Faculty of Physics, Lomonosov Moscow State University, Leninskie Gory, GSP-1, Moscow, 119991, Russia
| | - Franco Cortese
- Biogerontology Research Foundation, Apt 2354 Chynoweth House, Trevissome Park, Truro, London, TR4 8UN, UK
| | - Anca Ioviţă
- International Longevity Alliance, 19 avenue Jean Jaurès, Sceaux, 92330, France
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17
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Lakkaraju A, Umapathy A, Tan LX, Daniele L, Philp NJ, Boesze-Battaglia K, Williams DS. The cell biology of the retinal pigment epithelium. Prog Retin Eye Res 2020; 78:100846. [PMID: 32105772 PMCID: PMC8941496 DOI: 10.1016/j.preteyeres.2020.100846] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/19/2020] [Accepted: 02/23/2020] [Indexed: 02/07/2023]
Abstract
The retinal pigment epithelium (RPE), a monolayer of post-mitotic polarized epithelial cells, strategically situated between the photoreceptors and the choroid, is the primary caretaker of photoreceptor health and function. Dysfunction of the RPE underlies many inherited and acquired diseases that cause permanent blindness. Decades of research have yielded valuable insight into the cell biology of the RPE. In recent years, new technologies such as live-cell imaging have resulted in major advancement in our understanding of areas such as the daily phagocytosis and clearance of photoreceptor outer segment tips, autophagy, endolysosome function, and the metabolic interplay between the RPE and photoreceptors. In this review, we aim to integrate these studies with an emphasis on appropriate models and techniques to investigate RPE cell biology and metabolism, and discuss how RPE cell biology informs our understanding of retinal disease.
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Affiliation(s)
- Aparna Lakkaraju
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Ankita Umapathy
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Li Xuan Tan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Lauren Daniele
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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18
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Zhu Y, Aredo B, Chen B, Zhao CX, He YG, Ufret-Vincenty RL. Mice With a Combined Deficiency of Superoxide Dismutase 1 (Sod1), DJ-1 (Park7), and Parkin (Prkn) Develop Spontaneous Retinal Degeneration With Aging. Invest Ophthalmol Vis Sci 2020; 60:3740-3751. [PMID: 31487745 PMCID: PMC6733419 DOI: 10.1167/iovs.19-27212] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Chronic oxidative stress is an important mechanism of disease in aging disorders. We do not have a good model to recapitulate AMD and other retinal disorders in which chronic oxidative stress plays an important role. We hypothesized that mice with a combined deficiency in superoxide dismutase 1 (Sod1), DJ-1 (Park-7), and Parkin (Prkn) (triple knock out, TKO) would have an increased level of chronic oxidative stress in the retina, with anatomic and functional consequences just with aging. Methods Eyes of TKO and B6J control mice were (1) monitored with optical coherence tomography (OCT) and electroretinography (ERG) over time, and (2) collected for oxidative marker protein analysis by ELISA or immunohistochemistry and for transmission electron microscopy studies. Results TKO mice developed qualitative disruptions in outer retinal layers in OCT by 3 months, increased accumulation of fundus spots and subretinal microglia by 6 months of age, significant retinal thinning by 9 months, and decreased ERG signal by 12 months. Furthermore, we found increased accumulation of the oxidative marker malondialdehyde (MDA) in the retina and increased basal laminal deposits (BLD) and mitochondria number and size in the retinal pigment epithelium of aging TKO mice. Conclusions TKO mice can serve as a platform to study retinal diseases that involve chronic oxidative stress, including macular degeneration, retinal detachment, and ischemic retinopathies. In order to model each of these diseases, additional disease-specific catalysts or triggers could be superimposed onto the TKO mice. Such studies could provide better insight into disease mechanisms and perhaps lead to new therapeutic approaches.
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Affiliation(s)
- Yuanfei Zhu
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Bogale Aredo
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Bo Chen
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Cynthia X Zhao
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Yu-Guang He
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
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19
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Alaimo A, Di Santo MC, Domínguez Rubio AP, Chaufan G, García Liñares G, Pérez OE. Toxic effects of A2E in human ARPE-19 cells were prevented by resveratrol: a potential nutritional bioactive for age-related macular degeneration treatment. Arch Toxicol 2019; 94:553-572. [PMID: 31792590 DOI: 10.1007/s00204-019-02637-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 11/26/2019] [Indexed: 01/23/2023]
Abstract
Age-related macular degeneration (AMD) is a late-onset retinal disease and the leading cause of central vision loss in the elderly. Degeneration of retinal pigment epithelial cells (RPE) is a crucial contributing factor responsible for the onset and progression of AMD. The toxic fluorophore N-retinyl-N-retinylidene ethanolamine (A2E), a major lipofuscin component, accumulates in RPE cells with age. Phytochemicals with antioxidant properties may have a potential role in both the prevention and treatment of this age-related ocular disease. Particularly, there is an increased interest in the therapeutic effects of resveratrol (RSV), a naturally occurring polyphenol (3,4',5-trihydroxystilbene). However, the underlying mechanism of the RSV antioxidative effect in ocular diseases has not been well explored. We hypothesized that this bioactive compound may have beneficial effects for AMD. To this end, to investigate the potential profits of RSV against A2E-provoked oxidative damage, we used human RPE cell line (ARPE-19). RSV (25 µM) attenuates the cytotoxicity and the typical morphological characteristics of apoptosis observed in 25 µM A2E-laden cells. RSV pretreatment strengthened cell monolayer integrity through the preservation of the transepithelial electrical resistance and reduced the fluorescein isothiocyanate (FITC)-dextran diffusion rate as well as cytoskeleton architecture. In addition, RSV exhorts protective effects against A2E-induced modifications in the intracellular redox balance. Finally, RSV also prevented A2E-induced mitochondrial network fragmentation. These findings reinforce the idea that RSV represents an attractive bioactive for therapeutic intervention against ocular diseases associated with oxidative stress such as AMD.
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Affiliation(s)
- Agustina Alaimo
- Departamento de Química Biológica, Laboratorio Interdisciplinario de Dinámica Celular y Nanoherramientas, CONICET-Universidad de Buenos Aires, Instituto de Química Biológica Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina.
| | - Mariana Carolina Di Santo
- Departamento de Química Biológica, Laboratorio Interdisciplinario de Dinámica Celular y Nanoherramientas, CONICET-Universidad de Buenos Aires, Instituto de Química Biológica Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Ana Paula Domínguez Rubio
- Departamento de Química Biológica, Laboratorio Interdisciplinario de Dinámica Celular y Nanoherramientas, CONICET-Universidad de Buenos Aires, Instituto de Química Biológica Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Gabriela Chaufan
- Departamento de Química Biológica, Laboratorio de Enzimología, Estrés Oxidativo y Metabolismo, CONICET-Universidad de Buenos Aires, Instituto de Química Biológica Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Guadalupe García Liñares
- Departamento de Química Orgánica, Laboratorio de Biocatálisis, CONICET-Universidad de Buenos Aires, Unidad de Microanálisis y Métodos Físicos en Química Orgánica (UMYMFOR), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina
| | - Oscar Edgardo Pérez
- Departamento de Química Biológica, Laboratorio Interdisciplinario de Dinámica Celular y Nanoherramientas, CONICET-Universidad de Buenos Aires, Instituto de Química Biológica Ciencias Exactas y Naturales (IQUIBICEN), Facultad de Ciencias Exactas y Naturales, Pabellón 2, Ciudad Universitaria, 1428, Buenos Aires, Argentina.
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20
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Daniele LL, Caughey J, Volland S, Sharp RC, Dhingra A, Williams DS, Philp NJ, Boesze-Battaglia K. Peroxisome turnover and diurnal modulation of antioxidant activity in retinal pigment epithelia utilizes microtubule-associated protein 1 light chain 3B (LC3B). Am J Physiol Cell Physiol 2019; 317:C1194-C1204. [PMID: 31577510 DOI: 10.1152/ajpcell.00185.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The retinal pigment epithelium (RPE) supports the outer retina through essential roles in the retinoid cycle, nutrient supply, ion exchange, and waste removal. Each day the RPE removes the oldest ~10% of photoreceptor outer segment (OS) disk membranes through phagocytic uptake, which peaks following light onset. Impaired degradation of phagocytosed OS material by the RPE can lead to toxic accumulation of lipids, oxidative tissue damage, inflammation, and cell death. OSs are rich in very long chain fatty acids, which are preferentially catabolized in peroxisomes. Despite the importance of lipid degradation in RPE function, the regulation of peroxisome number and activity relative to diurnal OS ingestion is relatively unexplored. Using immunohistochemistry, immunoblot analysis, and catalase activity assays, we investigated peroxisome abundance and activity at 6 AM, 7 AM (light onset), 8 AM, and 3 PM, in wild-type (WT) mice and mice lacking microtubule-associated protein 1 light chain 3B (Lc3b), which have impaired phagosome degradation. We found that catalase activity, but not the amount of catalase protein, is 50% higher in the morning compared with 3 PM, in RPE of WT, but not Lc3b-/-, mice. Surprisingly, we found that peroxisome abundance was stable during the day in RPE of WT mice; however, numbers were elevated overall in Lc3b-/- mice, implicating LC3B in autophagic organelle turnover in RPE. Our data suggest that RPE peroxisome function is regulated in coordination with phagocytosis, possibly through direct enzyme regulation, and may serve to prepare RPE peroxisomes for daily surges in ingested lipid-rich OS.
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Affiliation(s)
- Lauren L Daniele
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jennifer Caughey
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stefanie Volland
- Department of Ophthalmology, Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Rachel C Sharp
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anuradha Dhingra
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David S Williams
- Department of Ophthalmology, Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, California.,Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California
| | - Nancy J Philp
- Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Kathleen Boesze-Battaglia
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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21
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Brown EE, DeWeerd AJ, Ildefonso CJ, Lewin AS, Ash JD. Mitochondrial oxidative stress in the retinal pigment epithelium (RPE) led to metabolic dysfunction in both the RPE and retinal photoreceptors. Redox Biol 2019; 24:101201. [PMID: 31039480 PMCID: PMC6488819 DOI: 10.1016/j.redox.2019.101201] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/10/2019] [Accepted: 04/11/2019] [Indexed: 12/22/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world. Recent evidence suggests that RPE and photoreceptors have an interconnected metabolism and that mitochondrial damage in RPE is a trigger for degeneration in both RPE and photoreceptors in AMD. To test this hypothesis, this study was designed to induce mitochondrial damage in RPE in mice to determine whether this is sufficient to cause RPE and photoreceptor damage characteristic of AMD. In this study, we conditionally deleted the gene encoding the mitochondrial antioxidant enzyme, manganese superoxide dismutase (MnSOD encoded by Sod2) in the retinal pigment epithelium (RPE) of albino BALB/cJ mice. VMD2-Cre;Sod2flox/flox BALB/cJ mice were housed in either 12-h dark, 12-h 200 lux white lighting (normal light), or 12-h dark, 12-h <10 lux red lighting (dim light). Electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT) were performed to assess retinal function and morphology. Immunofluorescence was used to examine protein expression; quantitative RT-PCR was used to measure gene expression. Sod2 knockout (KO) mice had reduced RPE function with age and increased oxidative stress compared to wild type (WT) controls as expected by the cell-specific deletion of Sod2. This was associated with alterations in RPE morphology and the structure and function of RPE mitochondria. In addition, data show a compensatory increase in RPE glycolytic metabolism. The metabolic shift in RPE correlated with severe disruption of photoreceptor mitochondria including a reduction in TOMM20 expression, mitochondrial fragmentation, and reduced COXIII/β-actin levels. These findings demonstrate that mitochondrial oxidative stress can lead to RPE dysfunction and metabolic reprogramming of RPE. Secondary to these changes, photoreceptors also undergo metabolic stress with increased mitochondrial damage. These data are consistent with the hypothesis of a linked metabolism between RPE and photoreceptors and suggest a mechanism of retinal degeneration in dry AMD. Deletion of Sod2 in the RPE led to loss of RPE function. Knockout mice had decreased ATP levels and decreased COXIII/β-actin levels in the RPE. Knockout mice had elevated expression of glycolytic enzymes in the RPE. RPE alterations led to secondary effects on photoreceptors.
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Affiliation(s)
- Emily E Brown
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA; Clinical and Translational Science Institute, University of Florida, Gainesville, FL, USA
| | - Alexander J DeWeerd
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Cristhian J Ildefonso
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - John D Ash
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, USA.
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22
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Toms M, Burgoyne T, Tracey-White D, Richardson R, Dubis AM, Webster AR, Futter C, Moosajee M. Phagosomal and mitochondrial alterations in RPE may contribute to KCNJ13 retinopathy. Sci Rep 2019; 9:3793. [PMID: 30846767 PMCID: PMC6405871 DOI: 10.1038/s41598-019-40507-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/18/2019] [Indexed: 12/29/2022] Open
Abstract
Mutations in KCNJ13 are associated with two retinal disorders; Leber congenital amaurosis (LCA) and snowflake vitreoretinal degeneration (SVD). We examined the retina of kcnj13 mutant zebrafish (obelixtd15, c.502T > C p.[Phe168Leu]) to provide new insights into the pathophysiology underlying these conditions. Detailed phenotyping of obelixtd15 fish revealed a late onset retinal degeneration at 12 months. Electron microscopy of the obelixtd15 retinal pigment epithelium (RPE) uncovered reduced phagosome clearance and increased mitochondrial number and size prior any signs of retinal degeneration. Melanosome distribution was also affected in dark-adapted 12-month obelixtd15 fish. At 6 and 12 months, ATP levels were found to be reduced along with increased expression of glial fibrillary acidic protein and heat shock protein 60. Quantitative RT-PCR of polg2, fis1, opa1, sod1/2 and bcl2a from isolated retina showed expression changes consistent with altered mitochondrial activity and retinal stress. We propose that the retinal disease in this model is primarily a failure of phagosome physiology with a secondary mitochondrial dysfunction. Our findings suggest that alterations in the RPE and photoreceptor cellular organelles may contribute to KCNJ13-related retinal degeneration and provide a therapeutic target.
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Affiliation(s)
- Maria Toms
- UCL Institute of Ophthalmology, London, UK
| | | | | | | | - Adam M Dubis
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew R Webster
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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23
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An in vitro protocol to study the effect of hyperglycemia on intracellular redox signaling in human retinal pigment epithelial (ARPE-19) cells. Mol Biol Rep 2019; 46:1263-1274. [DOI: 10.1007/s11033-019-04597-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/04/2019] [Indexed: 01/12/2023]
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Teves JMY, Bhargava V, Kirwan KR, Corenblum MJ, Justiniano R, Wondrak GT, Anandhan A, Flores AJ, Schipper DA, Khalpey Z, Sligh JE, Curiel-Lewandrowski C, Sherman SJ, Madhavan L. Parkinson's Disease Skin Fibroblasts Display Signature Alterations in Growth, Redox Homeostasis, Mitochondrial Function, and Autophagy. Front Neurosci 2018; 11:737. [PMID: 29379409 PMCID: PMC5770791 DOI: 10.3389/fnins.2017.00737] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/18/2017] [Indexed: 12/27/2022] Open
Abstract
The discovery of biomarkers for Parkinson's disease (PD) is challenging due to the heterogeneous nature of this disorder, and a poor correlation between the underlying pathology and the clinically expressed phenotype. An ideal biomarker would inform on PD-relevant pathological changes via an easily assayed biological characteristic, which reliably tracks clinical symptoms. Human dermal (skin) fibroblasts are accessible peripheral cells that constitute a patient-specific system, which potentially recapitulates the PD chronological and epigenetic aging history. Here, we compared primary skin fibroblasts obtained from individuals diagnosed with late-onset sporadic PD, and healthy age-matched controls. These fibroblasts were studied from fundamental viewpoints of growth and morphology, as well as redox, mitochondrial, and autophagic function. It was observed that fibroblasts from PD subjects had higher growth rates, and appeared distinctly different in terms of morphology and spatial organization in culture, compared to control cells. It was also found that the PD fibroblasts exhibited significantly compromised mitochondrial structure and function when assessed via morphological and oxidative phosphorylation assays. Additionally, a striking increase in baseline macroautophagy levels was seen in cells from PD subjects. Exposure of the skin fibroblasts to physiologically relevant stress, specifically ultraviolet irradiation (UVA), further exaggerated the autophagic dysfunction in the PD cells. Moreover, the PD fibroblasts accumulated higher levels of reactive oxygen species (ROS) coupled with lower cell viability upon UVA treatment. In essence, these studies highlight primary skin fibroblasts as a patient-relevant model that captures fundamental PD molecular mechanisms, and supports their potential utility to develop diagnostic and prognostic biomarkers for the disease.
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Affiliation(s)
- Joji M. Y. Teves
- Graduate Interdisciplinary Program in Applied Biosciences, University of Arizona, Tucson, AZ, United States
| | - Vedanshi Bhargava
- Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, United States
| | - Konner R. Kirwan
- Neuroscience and Cognitive Science Undergraduate Program, Undergraduate Biology Research Program, University of Arizona, Tucson, AZ, United States
| | - Mandi J. Corenblum
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Rebecca Justiniano
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Georg T. Wondrak
- Pharmacology and Toxicology, University of Arizona, Tucson, AZ, United States
| | - Annadurai Anandhan
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Andrew J. Flores
- Graduate Interdisciplinary Program in Physiological Sciences, University of Arizona, Tucson, AZ, United States
| | - David A. Schipper
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - Zain Khalpey
- Department of Surgery, University of Arizona, Tucson, AZ, United States
| | - James E. Sligh
- Department of Medicine, University of Arizona, Tucson, AZ, United States
| | | | - Scott J. Sherman
- Department of Neurology, University of Arizona, Tucson, AZ, United States
| | - Lalitha Madhavan
- Department of Neurology, University of Arizona, Tucson, AZ, United States,The Evelyn F McKnight Brain Institute, University of Arizona, Tucson, AZ, United States,*Correspondence: Lalitha Madhavan
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Mitochondria: Potential Targets for Protection in Age-Related Macular Degeneration. RETINAL DEGENERATIVE DISEASES 2018; 1074:11-17. [DOI: 10.1007/978-3-319-75402-4_2] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Om Parkash R, Mahajan S, Biala V, Om Parkash T, Tasneem AF. Flap motility as a sign of posterior capsule rupture in peripherally extended anterior capsular tears. Clin Ophthalmol 2017; 11:1445-1451. [PMID: 28860692 PMCID: PMC5558569 DOI: 10.2147/opth.s136532] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Purpose To describe various types of anterior capsular tears and an early diagnostic, flap motility, as a sign of posterior capsular rupture following posterior extension of radial tears. Design This was a prospective study carried out in 4,331 eyes that underwent phacoemulsification in a private practice setting from April 2015 to February 2016. Twenty six consecutive cases of anterior capsular tears were included. Morphological features of anterior capsular tears and resultant complications were evaluated. Parameters studied were surgical step during which the tear occurred, shape of tear, its extension in relation to the equator, and flap nature and motility in tear extending up to equator. Main outcome measures The main outcome measures were motility and nature of flaps in anterior capsular radial tears and the relation to posterior capsule rupture. Results Based on shape, extent, and angulation, anterior capsular tears were categorized into 5 types: Type I, pre-equatorial radial tear (26.92%); Type II, post-equatorial radial tear (3.85%); Type III, Argentinean flag sign pre-equatorial tear (57.69%); Type IV, Argentinean flag sign post-equatorial tear (7.69%), and Type V, mini punch (3.85%). Flaps were either seen to be everted and fluttering or inverted and non-fluttering. In all cases with everted fluttering flaps no posterior capsular rupture (PCR) was observed, while in cases with inverted non-fluttering flaps a PCR was observed (p<0.05). Conclusion Everted and fluttering flaps of the anterior capsular tears indicate pre-equatorial tear, while inverted and non-fluttering flaps indicate posterior capsule rupture following tear extension beyond the equator.
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Affiliation(s)
| | - Shruti Mahajan
- Department of Cataract and Refractive Surgery, Dr Om Parkash Eye Institute, Amritsar
| | - Vinod Biala
- Department of Cataract Surgery, Eye Care Centre, Ghaziabad
| | | | - Alhaj F Tasneem
- Department of Ophthalmology, Vydehi Institute of Medical Sciences and Research Centre, Bangalore, India
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Pacella E, Pacella F, De Paolis G, Parisella FR, Turchetti P, Anello G, Cavallotti C. Glycosaminoglycans in the human cornea: age-related changes. OPHTHALMOLOGY AND EYE DISEASES 2015; 7:1-5. [PMID: 25674020 PMCID: PMC4310673 DOI: 10.4137/oed.s17204] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 09/16/2014] [Accepted: 09/30/2014] [Indexed: 11/05/2022]
Abstract
AIM To investigate possible age-related changes in glycosaminoglycans (GAGs) in the human cornea. The substances today called GAGs were previously referred to as mucopolysaccharides. METHODS Samples of human cornea were taken from 12 younger (age 21 ± 1.2) and 12 older (age 72 ± 1.6) male subjects. Samples were weighed, homogenized, and used for biochemical and molecular analyses. All the quantitative results were statistically analyzed. RESULTS The human cornea appears to undergo age-related changes, as evidenced by our biochemical and molecular results. The total GAG and hyaluronic acid counts were significantly higher in the younger subjects than in the older subjects. The sulfated heavy GAGs, such as chondroitin, dermatan, keratan, and heparan sulfate, were lower in the younger subjects than in the older subjects. DISCUSSION GAGs of the human cornea undergo numerous age-related changes. Their quantity is significantly altered in the elderly in comparison with younger subjects. GAGs play an important role in age-related diseases of the human cornea.
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Affiliation(s)
- Elena Pacella
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome, Italy
| | - Fernanda Pacella
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome, Italy
| | - Giulio De Paolis
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome, Italy
| | | | - Paolo Turchetti
- National Institute for Health, Migration and Poverty (INMP/NIHMP), Rome, Italy
| | - Giulia Anello
- Department of Sense Organs, Faculty of Medicine and Dentistry, Sapienza University of Rome, Rome, Italy
| | - Carlo Cavallotti
- Section of Human Anatomy, Sapienza University of Rome, Rome, Italy
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Craword SE, Fitchev P, Veliceasa D, Volpert OV. The many facets of PEDF in drug discovery and disease: a diamond in the rough or split personality disorder? Expert Opin Drug Discov 2013; 8:769-92. [PMID: 23642051 DOI: 10.1517/17460441.2013.794781] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Pigment epithelium-derived factor (PEDF) was discovered as a neurotrophic factor secreted by retinal pigment epithelial cells. A decade later, it re-emerged as a powerful angiogenesis inhibitor guarding ocular function. Since then, significant advances were made identifying PEDF's mechanisms, targets and biomedical applications. AREAS COVERED The authors review several methodologies that have generated significant new information about the potential of PEDF as a drug. Furthermore, the authors review and discuss mechanistic and structure-function analyses combined with the functional mapping of active fragments, which have yielded several short bioactive PEDF peptides. Additionally, the authors present functional studies in knockout animals and human correlates that have provided important information about conditions amenable to PEDF-based therapies. EXPERT OPINION Through its four known receptors, PEDF causes a wide range of cellular events vitally important for the organism, which include survival and differentiation, migration and invasion, lipid metabolism and stem cell maintenance. These processes are deregulated in multiple pathological conditions, including cancer, metabolic and cardiovascular disease. PEDF has been successfully used in countless preclinical models of these conditions and human correlates suggest a wide utility of PEDF-based drugs. The most significant clinical application of PEDF, to date, is its potential therapeutic use for age-related macular degeneration. Moreover, PEDF-based gene therapy has advanced to early stage clinical trials. PEDF active fragments have been mapped and used to design short peptide mimetics conferring distinct functions of PEDF, which may address specific clinical problems and become prototype drugs.
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Affiliation(s)
- Susan E Craword
- St. Louis University School of Medicine, Department of Pathology, St. Louis, Missouri, USA
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