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Motipally SI, Kolson DR, Guan T, Kolandaivelu S. Aberrant Lipid Accumulation leads to Retinal Pigmental Epithelium Dysfunction and Photoreceptor Degeneration in Prcd -deficient mice. bioRxiv 2024:2024.03.08.584131. [PMID: 38558979 PMCID: PMC10979840 DOI: 10.1101/2024.03.08.584131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
P rogressive R od- C one D egeneration (PRCD) is an integral membrane protein exclusively expressed in photoreceptor outer segment (OS) disc membranes with an unknown function. Several mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. Canine Prcd -mutant models show decreased levels of Docosahexaenoic acid (DHA, 22:6n-3) in the OS, and both DHA and cholesterol in the plasma. However, potential changes in the levels of retinal cholesterol remain unexplored. In the present study, we investigate both the alterations in the retinal cholesterol levels and the under-studied pathophysiological changes that occur in the RPE of Prcd -deficient mice using a global Prcd -knockout mouse model. We report multiple lines of evidence supporting elevated levels of cholesteryl esters (C.Es) in the photoreceptors, and accumulation of lipid deposits in the RPE of Prcd -deficient mice. Strikingly, Prcd -deficient mice exhibit thickened Bruch's membrane (BrM), subretinal and sub-RPE drusenoid focal deposits mimicking an Age-related Macular Degeneration (AMD)-like phenotype. We additionally report extensive lipofuscin accumulation and propose that it can lead to RPE lysosomal dysfunction which may underlie the impaired phagocytosis observed in Prcd -deficient mice. Altogether, our data demonstrates structural and functional deficits in the RPE in addition to the altered total retinal cholesterol in Prcd -deficient mice.
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Eade KT, Ansell BRE, Giles S, Fallon R, Harkins-Perry S, Nagasaki T, Tzaridis S, Wallace M, Mills EA, Farashi S, Johnson A, Sauer L, Hart B, Diaz-Rubio ME, Bahlo M, Metallo C, Allikmets R, Gantner ML, Bernstein PS, Friedlander M. iPSC-derived retinal pigmented epithelial cells from patients with macular telangiectasia show decreased mitochondrial function. J Clin Invest 2023; 133:e163771. [PMID: 37115691 PMCID: PMC10145939 DOI: 10.1172/jci163771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/14/2023] [Indexed: 04/29/2023] Open
Abstract
Patient-derived induced pluripotent stem cells (iPSCs) provide a powerful tool for identifying cellular and molecular mechanisms of disease. Macular telangiectasia type 2 (MacTel) is a rare, late-onset degenerative retinal disease with an extremely heterogeneous genetic architecture, lending itself to the use of iPSCs. Whole-exome sequencing screens and pedigree analyses have identified rare causative mutations that account for less than 5% of cases. Metabolomic surveys of patient populations and GWAS have linked MacTel to decreased circulating levels of serine and elevated levels of neurotoxic 1-deoxysphingolipids (1-dSLs). However, retina-specific, disease-contributing factors have yet to be identified. Here, we used iPSC-differentiated retinal pigmented epithelial (iRPE) cells derived from donors with or without MacTel to screen for novel cell-intrinsic pathological mechanisms. We show that MacTel iRPE cells mimicked the low serine levels observed in serum from patients with MacTel. Through RNA-Seq and gene set enrichment pathway analysis, we determined that MacTel iRPE cells are enriched in cellular stress pathways and dysregulation of central carbon metabolism. Using respirometry and mitochondrial stress testing, we functionally validated that MacTel iRPE cells had a reduction in mitochondrial function that was independent of defects in serine biosynthesis and 1-dSL accumulation. Thus, we identified phenotypes that may constitute alternative disease mechanisms beyond the known serine/sphingolipid pathway.
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Affiliation(s)
- Kevin T. Eade
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Brendan Robert E. Ansell
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah Giles
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Regis Fallon
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Sarah Harkins-Perry
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Takayuki Nagasaki
- Department of Ophthalmology and
- Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Simone Tzaridis
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Martina Wallace
- Institute of Food and Health, School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Elizabeth A. Mills
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Samaneh Farashi
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Alec Johnson
- The Lowy Medical Research Institute, La Jolla, California, USA
| | - Lydia Sauer
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Barbara Hart
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - M. Elena Diaz-Rubio
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
| | - Melanie Bahlo
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Christian Metallo
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California, USA
- Department of Bioengineering, University of California San Diego, La Jolla, California, USA
| | - Rando Allikmets
- Department of Ophthalmology and
- Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Marin L. Gantner
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
| | - Paul S. Bernstein
- Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Martin Friedlander
- The Lowy Medical Research Institute, La Jolla, California, USA
- Department of Molecular Medicine, The Scripps Research Institute (TSRI), La Jolla, California, USA
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Lazzara F, Conti F, Platania CBM, Eandi CM, Drago F, Bucolo C. Effects of Vitamin D 3 and Meso-Zeaxanthin on Human Retinal Pigmented Epithelial Cells in Three Integrated in vitro Paradigms of Age-Related Macular Degeneration. Front Pharmacol 2021; 12:778165. [PMID: 34803719 PMCID: PMC8602342 DOI: 10.3389/fphar.2021.778165] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 09/30/2021] [Indexed: 11/13/2022] Open
Abstract
Age-related macular degeneration (AMD) is a degenerative retinal disease and one of major causes of irreversible vision loss. AMD has been linked to several pathological factors, such as oxidative stress and inflammation. Moreover, Aβ (1-42) oligomers have been found in drusen, the extracellular deposits that accumulate beneath the retinal pigmented epithelium in AMD patients. Hereby, we investigated the hypothesis that treatment with 1,25(OH) 2D3 (vitamin D3) and meso-zeaxathin, physiologically present in the eye, would counteract the toxic effects of three different insults on immortalized human retinal pigmented epithelial cells (ARPE-19). Specifically, ARPE-19 cells have been challenged with Aβ (1-42) oligomers, H2O2, LPS, and TNF-α, respectively. In the present study, we demonstrated that the combination of 1,25(OH)2D3 and meso-zeaxanthin significantly counteracted the cell damage induced by the three insults, at least in these in vitro integrated paradigms of AMD. These results suggest that combination of 1,25(OH)2D3 and meso-zeaxathin could be a useful approach to contrast pathological features of AMD, such as retinal inflammation and oxidative stress.
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Affiliation(s)
- Francesca Lazzara
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Federica Conti
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Chiara Bianca Maria Platania
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Chiara M Eandi
- Department of Ophthalmology, Fondation Asile des Aveugles, Jules Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland.,Department of Surgical Sciences, University of Torino, Torino, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
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Lynn SA, Johnston DA, Scott JA, Munday R, Desai RS, Keeling E, Weaterton R, Simpson A, Davis D, Freeman T, Chatelet DS, Page A, Cree AJ, Lee H, Newman TA, Lotery AJ, Ratnayaka JA. Oligomeric Aβ 1-42 Induces an AMD-Like Phenotype and Accumulates in Lysosomes to Impair RPE Function. Cells 2021; 10:413. [PMID: 33671133 PMCID: PMC7922851 DOI: 10.3390/cells10020413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/04/2021] [Accepted: 02/11/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease-associated amyloid beta (Aβ) proteins accumulate in the outer retina with increasing age and in eyes of age-related macular degeneration (AMD) patients. To study Aβ-induced retinopathy, wild-type mice were injected with nanomolar human oligomeric Aβ1-42, which recapitulate the Aβ burden reported in human donor eyes. In vitro studies investigated the cellular effects of Aβ in endothelial and retinal pigment epithelial (RPE) cells. Results show subretinal Aβ-induced focal AMD-like pathology within 2 weeks. Aβ exposure caused endothelial cell migration, and morphological and barrier alterations to the RPE. Aβ co-localized to late-endocytic compartments of RPE cells, which persisted despite attempts to clear it through upregulation of lysosomal cathepsin B, revealing a novel mechanism of lysosomal impairment in retinal degeneration. The rapid upregulation of cathepsin B was out of step with the prolonged accumulation of Aβ within lysosomes, and contrasted with enzymatic responses to internalized photoreceptor outer segments (POS). Furthermore, RPE cells exposed to Aβ were identified as deficient in cargo-carrying lysosomes at time points that are critical to POS degradation. These findings imply that Aβ accumulation within late-endocytic compartments, as well as lysosomal deficiency, impairs RPE function over time, contributing to visual defects seen in aging and AMD eyes.
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Affiliation(s)
- Savannah A. Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - David A. Johnston
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Jenny A. Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Roshni S. Desai
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Ruaridh Weaterton
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Alexander Simpson
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Dillon Davis
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Thomas Freeman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - David S. Chatelet
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, Southampton SO16 6YD, UK; (D.A.J.); (D.S.C.); (A.P.)
| | - Angela J. Cree
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Helena Lee
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - Tracey A. Newman
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK
| | - J. Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP 806, Tremona Road, Southampton SO16 6YD, UK; (S.A.L.); (J.A.S.); (R.M.); (R.S.D.); (E.K.); (R.W.); (A.S.); (D.D.); (T.F.); (A.J.C.); (H.L.); (T.A.N.); (A.J.L.)
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Yue B, Zhang X, Li W, Wang J, Sun Z, Niu R. Fluoride exposure altered metabolomic profile in rat serum. Chemosphere 2020; 258:127387. [PMID: 32947680 DOI: 10.1016/j.chemosphere.2020.127387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/07/2020] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
It is well known that serum is an ideal and potential choice to reflect the toxicity of fluoride. However, the effects of fluoride on serum metabolome have not been reported until now. In this study, the models of 3-week-old rats exposed fluoride by breast milk and 11-week-old rats exposed fluoride via breast milk and drinking water containing sodium fluoride (100 mg/L) were established. Using Ultra Performance Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (UPLC-MS/MS), as compared with control group, 28 negative (NEG) and 52 positive (POS) metabolites were significantly up-regulated, meanwhile 30 NEG and 21 POS significantly down-regulated metabolites were found in serum of 3-week-old rats exposed to fluoride. For 11-week-old fluorosis rats, there were 119 NEG and 65 POS metabolites significantly increased, and 7 NEG, 5 POS metabolites were obviously decreased. Importantly, nicotinamide, adenosine, 1-Oleoyl-sn-glycero-3-phosphocholine (OGPC), and 1-Stearoyl-sn-glycerol 3-phosphocholine (SGPC) were shared by two models. The metabolites of urea cycle, such as urea and N2-Acetyl-l-ornithine, betaine as a methyl donor, were regarded to reflect the fluorosis degree. These metabolites could be the potential markers of fluorosis, contributing to the prevention and treatment of fluorosis.
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Affiliation(s)
- Baijuan Yue
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China
| | - Xuhua Zhang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China
| | - Wanpan Li
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China
| | - Jundong Wang
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China
| | - Zilong Sun
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China.
| | - Ruiyan Niu
- Shanxi Key Laboratory of Ecological Animal Science and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi, 030801, China.
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Wu T, Xu W, Wang Y, Tao M, Hu Z, Lv B, Hui Y, Du H. OxLDL enhances choroidal neovascularization lesion through inducing vascular endothelium to mesenchymal transition process and angiogenic factor expression. Cell Signal 2020; 70:109571. [DOI: 10.1016/j.cellsig.2020.109571] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/16/2020] [Accepted: 02/16/2020] [Indexed: 10/25/2022]
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Daftarian N, Zandi S, Piryaie G, Nikougoftar Zarif M, Ranaei Pirmardan E, Yamaguchi M, Behzadian Nejad Q, Hasanpour H, Samiei S, Pfister IB, Soheili ZS, Nakao S, Barakat A, Garweg JG, Ahmadieh H, Hafezi-Moghadam A. Peripheral blood CD163(+) monocytes and soluble CD163 in dry and neovascular age-related macular degeneration. FASEB J 2020; 34:8001-8011. [PMID: 32333612 DOI: 10.1096/fj.201901902rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 03/12/2020] [Accepted: 03/30/2020] [Indexed: 11/11/2022]
Abstract
Macrophages are the main infiltrating immune cells in choroidal neovascularization (CNV), a hallmark of the human wet, or neovascular age-related macular degeneration (AMD). Due to their plasticity and ability to adapt to the local microenvironment in a tissue-dependent manner, macrophages display polar functional phenotypes characterized by their cell surface markers and their cytokine profiles. We found accumulation of hemoglobin-scavenging cluster of differentiation 163 (CD163)(+) macrophages in laser-induced CNV lesions and higher expression of CD163(+) monocytes in the peripheral blood on day 7 post injury in mice. In comparison, CD80(+) macrophages did not differ with laser-injury in young or aged mice and did not significantly change in the peripheral blood of CNV mice. We examined the percentages of CD163(+), CD206(+), and CD80(+) monocytes in the peripheral blood of patients with wet AMD, patients with dry AMD, and in age-matched individuals without AMD as controls. Percentages of peripheral blood CD163(+) monocytes in both dry AMD (P < .001) and wet AMD (P < .05) were higher than in age-matched non-AMD controls, while there was no difference between the groups in the percentages of peripheral CD206(+) and CD80(+) monocytes. Further, serum level of soluble CD163 (sCD163) was elevated only in patients with wet AMD (P < .05). An examination of 40 cytokine levels across the study groups revealed that anti-VEGF treated patients with wet AMD, who showed no exudative signs on the day of blood drawing had a cytokine profile that was similar to that of non-AMD individuals. These results indicate that CD163 could be further evaluated for its potential as a useful marker of disease activity in patients with neovascular AMD. Future studies will address the origin and potential mechanistic role of CD163(+) macrophages in wet AMD pathologies of angiogenesis and leakage of blood components.
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Affiliation(s)
- Narsis Daftarian
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA.,Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Souska Zandi
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Swiss Eye Institute, Rotkreuz and Berner Augenklinik am Lindenhofspital, Bern, Switzerland.,Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Golbarg Piryaie
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahin Nikougoftar Zarif
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Ehsan Ranaei Pirmardan
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Muneo Yamaguchi
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Qurban Behzadian Nejad
- Negah Specialty Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Hasanpour
- Negah Specialty Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shahram Samiei
- Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran
| | - Isabel B Pfister
- Swiss Eye Institute, Rotkreuz and Berner Augenklinik am Lindenhofspital, Bern, Switzerland
| | - Zahra-Soheila Soheili
- Department of Molecular Medicine, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Shintaro Nakao
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Aliaa Barakat
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Justus G Garweg
- Swiss Eye Institute, Rotkreuz and Berner Augenklinik am Lindenhofspital, Bern, Switzerland.,Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Hamid Ahmadieh
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA.,Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Hafezi-Moghadam
- Molecular Biomarkers Nano-Imaging Laboratory, Brigham and Women's Hospital, Boston, MA, USA.,Department of Radiology, Harvard Medical School, Boston, MA, USA
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Notomi S, Ishihara K, Efstathiou NE, Lee JJ, Hisatomi T, Tachibana T, Konstantinou EK, Ueta T, Murakami Y, Maidana DE, Ikeda Y, Kume S, Terasaki H, Sonoda S, Blanz J, Young L, Sakamoto T, Sonoda KH, Saftig P, Ishibashi T, Miller JW, Kroemer G, Vavvas DG. Genetic LAMP2 deficiency accelerates the age-associated formation of basal laminar deposits in the retina. Proc Natl Acad Sci U S A 2019; 116:23724-34. [PMID: 31699817 DOI: 10.1073/pnas.1906643116] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Extracellular tissue debris accumulates with aging and in the most prevalent central-vision-threatening eye disorder, age-related macular degeneration (AMD). In this work, we discovered that lysosome-associated membrane protein-2 (LAMP2), a glycoprotein that plays a critical role in lysosomal biogenesis and maturation of autophagosomes/phagosomes, is preferentially expressed in the outermost, neuroepithelial layer of the retina, the retinal pigment epithelium (RPE), and contributes to the prevention of ultrastructural changes in extracellular basolaminar deposits including lipids and apolipoproteins. LAMP2 thus appears to play an important role in RPE biology, and its apparent decrease with aging and in AMD specimens suggests that its deficiency may accelerate the basolaminar deposit formation and RPE dysfunction seen in these conditions. The early stages of age-related macular degeneration (AMD) are characterized by the accumulation of basal laminar deposits (BLamDs). The mechanism for BLamDs accumulating between the retinal pigment epithelium (RPE) and its basal lamina remains elusive. Here we examined the role in AMD of lysosome-associated membrane protein-2 (LAMP2), a glycoprotein that plays a critical role in lysosomal biogenesis and maturation of autophagosomes/phagosomes. LAMP2 was preferentially expressed by RPE cells, and its expression declined with age. Deletion of the Lamp2 gene in mice resulted in age-dependent autofluorescence abnormalities of the fundus, thickening of Bruch’s membrane, and the formation of BLamDs, resembling histopathological changes occurring in AMD. Moreover, LAMP2-deficient mice developed molecular signatures similar to those found in human AMD—namely, the accumulation of APOE, APOA1, clusterin, and vitronectin—adjacent to BLamDs. In contrast, collagen 4, laminin, and fibronectin, which are extracellular matrix proteins constituting RPE basal lamina and Bruch’s membrane were reduced in Lamp2 knockout (KO) mice. Mechanistically, retarded phagocytic degradation of photoreceptor outer segments compromised lysosomal degradation and increased exocytosis in LAMP2-deficient RPE cells. The accumulation of BLamDs observed in LAMP2-deficient mice was eventually followed by loss of the RPE and photoreceptors. Finally, we observed loss of LAMP2 expression along with ultramicroscopic features of abnormal phagocytosis and exocytosis in eyes from AMD patients but not from control individuals. Taken together, these results indicate an important role for LAMP2 in RPE function in health and disease, suggesting that LAMP2 reduction may contribute to the formation of BLamDs in AMD.
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Keeling E, Chatelet DS, Johnston DA, Page A, Tumbarello DA, Lotery AJ, Ratnayaka JA. Oxidative Stress and Dysfunctional Intracellular Traffic Linked to an Unhealthy Diet Results in Impaired Cargo Transport in the Retinal Pigment Epithelium (RPE). Mol Nutr Food Res 2019; 63:e1800951. [PMID: 30835933 DOI: 10.1002/mnfr.201800951] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/18/2019] [Indexed: 12/19/2022]
Abstract
SCOPE Oxidative stress and dysregulated intracellular trafficking are associated with an unhealthy diet which underlies pathology. Here, these effects on photoreceptor outer segment (POS) trafficking in the retinal pigment epithelium (RPE), a major pathway of disease underlying irreversible sight-loss, are studied. METHODS AND RESULTS POS trafficking is studied in ARPE-19 cells using an algorithm-based quantification of confocal-immunofluorescence data supported by ultrastructural studies. It is shown that although POS are tightly regulated and trafficked via Rab5, Rab7 vesicles, LAMP1/2 lysosomes and LC3b-autophagosomes, there is also a considerable degree of variation and flexibility in this process. Treatment with H2 O2 and bafilomycin A1 reveals that oxidative stress and dysregulated autophagy target intracellular compartments and trafficking in strikingly different ways. These effects appear limited to POS-containing vesicles, suggesting a cargo-specific effect. CONCLUSION The findings offer insights into how RPE cells cope with stress, and how mechanisms influencing POS transport/degradation can have different outcomes in the senescent retina. These shed new light on cellular processes underlying retinopathies such as age-related macular degeneration. The discoveries reveal how diet and nutrition can cause fundamental alterations at a cellular level, thus contributing to a better understanding of the diet-disease axis.
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Affiliation(s)
- Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, SO16 6YD, UK
| | - David S Chatelet
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, SO16 6YD, UK
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, SO16 6YD, UK
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, MP12, Tremona Road, SO16 6YD, UK
| | - David A Tumbarello
- Biological Sciences, Faculty of Natural & Environmental Sciences, University of Southampton, Life Sciences Building 85, SO17 1BJ, UK
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, SO16 6YD, UK
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, SO16 6YD, UK
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, MP806, Tremona Road, SO16 6YD, UK
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Alamri A, Biswas L, Watson DG, Shu X. Deletion of TSPO Resulted in Change of Metabolomic Profile in Retinal Pigment Epithelial Cells. Int J Mol Sci 2019; 20:E1387. [PMID: 30893912 DOI: 10.3390/ijms20061387] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration is the main cause of vision loss in the aged population worldwide. Drusen, extracellular lesions formed underneath the retinal pigment epithelial (RPE) cells, are a clinical feature of AMD and associated with AMD progression. RPE cells support photoreceptor function by providing nutrition, phagocytosing outer segments and removing metabolic waste. Dysfunction and death of RPE cells are early features of AMD. The translocator protein, TSPO, plays an important role in RPE cholesterol efflux and loss of TSPO results in increased intracellular lipid accumulation and reactive oxygen species (ROS) production. This study aimed to investigate the impact of TSPO knockout on RPE cellular metabolism by identifying the metabolic differences between wildtype and knockout RPE cells, with or without treatment with oxidized low density lipoprotein (oxLDL). Using liquid chromatography mass spectrometry (LC/MS), we differentiated several metabolic pathways among wildtype and knockout cells. Lipids amongst other intracellular metabolites were the most influenced by loss of TSPO and/or oxLDL treatment. Glucose, amino acid and nucleotide metabolism was also affected. TSPO deletion led to up-regulation of fatty acids and glycerophospholipids, which in turn possibly affected the cell membrane fluidity and stability. Higher levels of glutathione disulphide (GSSG) were found in TSPO knockout RPE cells, suggesting TSPO regulates mitochondrial-mediated oxidative stress. These data provide biochemical insights into TSPO-associated function in RPE cells and may shed light on disease mechanisms in AMD.
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Abstract
In order to improve the current success of nanomedicine, a better understanding of how nano-sized materials interact with and are processed by cells is required. Typical in vitro nanoparticle-cell interaction studies often make use of cells cultured at different cell densities. However, in vivo, for their successful delivery to the target tissue, nanomedicines need to overcome several barriers, such as endothelial and epithelial cell barriers. Unlike sub-confluent or confluent cell cultures, cell barriers are tight cell monolayers, expressing a series of specialized tight junction proteins between adjacent cells to limit paracellular transport and ensure close cell-to-cell interactions. A clear understanding on how the development of cells into a cell barrier may affect the uptake of nano-sized drug carriers is still missing. To this aim, here, human primary umbilical vein endothelial cells (HUVEC) are used as a model cell line to form endothelial cell barriers. Then, nanoparticle uptake is assessed in the developed endothelial barriers and compared to the uptake in sub-confluent or confluent HUVEC cultures. The results clearly show that the organization of cells into a cell barrier leads to a differential gene expression of endocytic markers, and - interestingly - this is accompanied by reduced nanoparticle uptake levels. Transport inhibitors are used to characterise the mechanisms involved in the uptake. However, we show that some of them can strongly compromise barrier integrity, thus impairing the interpretation of the outcomes, and overall, only a partial inhibition of nanoparticle uptake could be obtained.
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Affiliation(s)
- Valentina Francia
- Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
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12
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Lynn SA, Keeling E, Dewing JM, Johnston DA, Page A, Cree AJ, Tumbarello DA, Newman TA, Lotery AJ, Ratnayaka JA. A convenient protocol for establishing a human cell culture model of the outer retina. F1000Res 2018; 7:1107. [PMID: 30271583 PMCID: PMC6137423 DOI: 10.12688/f1000research.15409.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/28/2018] [Indexed: 12/12/2022] Open
Abstract
The retinal pigment epithelium (RPE) plays a key role in the pathogenesis of several blinding retinopathies. Alterations to RPE structure and function are reported in Age-related Macular Degeneration, Stargardt and Best disease as well as pattern dystrophies. However, the precise role of RPE cells in disease aetiology remains incompletely understood. Many studies into RPE pathobiology have utilised animal models, which only recapitulate limited disease features. Some studies are also difficult to carry out in animals as the ocular space remains largely inaccessible to powerful microscopes. In contrast, in-vitro models provide an attractive alternative to investigating pathogenic RPE changes associated with age and disease. In this article we describe the step-by-step approach required to establish an experimentally versatile in-vitro culture model of the outer retina incorporating the RPE monolayer and supportive Bruch's membrane (BrM). We show that confluent monolayers of the spontaneously arisen human ARPE-19 cell-line cultured under optimal conditions reproduce key features of native RPE. These models can be used to study dynamic, intracellular and extracellular pathogenic changes using the latest developments in microscopy and imaging technology. We also discuss how RPE cells from human foetal and stem-cell derived sources can be incorporated alongside sophisticated BrM substitutes to replicate the aged/diseased outer retina in a dish. The work presented here will enable users to rapidly establish a realistic in-vitro model of the outer retina that is amenable to a high degree of experimental manipulation which will also serve as an attractive alternative to using animals. This in-vitro model therefore has the benefit of achieving the 3Rs objective of reducing and replacing the use of animals in research. As well as recapitulating salient structural and physiological features of native RPE, other advantages of this model include its simplicity, rapid set-up time and unlimited scope for detailed single-cell resolution and matrix studies.
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Affiliation(s)
- Savannah A. Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Jennifer M. Dewing
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - David A. Johnston
- Biomedical Imaging Unit, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Anton Page
- Biomedical Imaging Unit, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Angela J. Cree
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - David A. Tumbarello
- Biological Sciences, Faculty of Natural & Environmental Sciences, Life Sciences Building 85, University of Southampton, Southampton, Hampshire, SO17 1BJ, UK
| | - Tracey A. Newman
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
| | - Andrew J. Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
- Eye Unit, University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, SO16 6YD, UK
| | - J. Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, MP 806, Tremona Road, University of Southampton, Southampton, Hampshire, SO16 6YD, UK
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Lin YC, Horng LY, Sung HC, Wu RT. Sodium Iodate Disrupted the Mitochondrial-Lysosomal Axis in Cultured Retinal Pigment Epithelial Cells. J Ocul Pharmacol Ther 2018; 34:500-511. [PMID: 30020815 DOI: 10.1089/jop.2017.0073] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Low doses of sodium iodate (NaIO3) impair visual function in experimental animals with selective damage to retinal pigment epithelium (RPE) and serve as a useful model to study diseases caused by RPE degeneration. Mitochondrial dysfunction and defective autophagy have been suggested to play important roles in normal aging as well as many neurodegenerative diseases. In this study, we examined whether NaIO3 treatment disrupted the mitochondrial-lysosomal axis in cultured RPE. METHODS The human RPE cell line, ARPE-19, was treated with low concentrations (≤500 μM) of NaIO3. The expression of proteins involved in the autophagic pathway and mitochondrial biogenesis was examined with Western blot. Intracellular acidic compartments and lipofuscinogenesis were evaluated by acridine orange staining and autofluorescence, respectively. Mitochondrial mass, mitochondrial membrane potential (MMP), and mitochondrial function were quantified by MitoTracker Green staining, tetramethylrhodamine methyl ester staining, and the MTT assay, respectively. Phagocytosis and the degradation of photoreceptor outer segments (POS) were assessed by fluorescence-based approaches and Western blot against rhodopsin. RESULTS Treatment with low concentrations of NaIO3 decreased cellular acidity, blocked autophagic flux, and resulted in increased lipofuscinogenesis in ARPE-19 cells. Despite increases in protein levels of Sirtuin 1 and PGC-1α, mitochondrial function was compromised, and this decrease was attributed to disrupted MMP. POS phagocytic activities decreased by 60% in NaIO3-treated cells, and the degradation of ingested POS was also impaired. Pretreatment and cotreatment with rapamycin partially rescued NaIO3-induced RPE dysfunction. CONCLUSIONS Low concentrations of NaIO3 disrupted the mitochondrial-lysosomal axis in RPE and led to impaired phagocytic activities and degradation capacities.
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Affiliation(s)
- Ying-Cheng Lin
- 1 Institute of Biopharmaceutical Sciences, School of Pharmaceutical Sciences, National Yang-Ming University , Taipei, Taiwan .,2 Department of Ophthalmology, Yang-Ming branch, Taipei City Hospital , Taipei, Taiwan
| | - Lin-Yea Horng
- 1 Institute of Biopharmaceutical Sciences, School of Pharmaceutical Sciences, National Yang-Ming University , Taipei, Taiwan .,3 Research Center for Drug Discovery, National Yang-Ming University , Taipei, Taiwan
| | - Hui-Ching Sung
- 3 Research Center for Drug Discovery, National Yang-Ming University , Taipei, Taiwan
| | - Rong-Tsun Wu
- 1 Institute of Biopharmaceutical Sciences, School of Pharmaceutical Sciences, National Yang-Ming University , Taipei, Taiwan .,3 Research Center for Drug Discovery, National Yang-Ming University , Taipei, Taiwan .,4 Graduate Institute of Natural Products, College of Pharmacy, Kaohsiung Medical University , Kaohsiung, Taiwan
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14
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Gautam J, Banskota S, Shah S, Jee JG, Kwon E, Wang Y, Kim DY, Chang HW, Kim JA. 4-Hydroxynonenal-induced GPR109A (HCA 2 receptor) activation elicits bipolar responses, G αi -mediated anti-inflammatory effects and G βγ -mediated cell death. Br J Pharmacol 2018; 175:2581-2598. [PMID: 29473951 DOI: 10.1111/bph.14174] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 12/07/2017] [Accepted: 01/30/2018] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE In this study, we examined the possibility that 4-hydroxynonenal (4-HNE) acting as a ligand for the HCA2 receptor (GPR109A) elicits both anti-inflammatory and cell death responses. EXPERIMENTAL APPROACH Agonistic activity of 4-HNE was determined by observing the inhibition of cAMP generation in CHO-K1-GPR109A-Gi cell line, using surface plasmon resonance (SPR) binding and competition binding assays with [3 H]-niacin. 4-HNE-mediated signalling pathways and cellular responses were investigated in cells expressing GPR109A and those not expressing these receptors. KEY RESULTS Agonistic activity of 4-HNE was stronger than that of niacin or 3-OHBA at inhibiting forskolin-induced cAMP production and SPR binding affinity. In ARPE-19 and CCD-841 cells, activation of GPR109A by high concentrations of the agonists 4-HNE (≥10 μM), niacin (≥1000 μM) and 3-OHBA (≥1000 μM) induced apoptosis accompanied by elevated Ca2+ and superoxide levels. This 4-HNE-induced cell death was blocked by knockdown of GPR109A or NOX4 genes, or treatment with chemical inhibitors of Gβγ (gallein), intracellular Ca2+ (BAPTA-AM), NOX4 (VAS2870) and JNK (SP600125), but not by the cAMP analogue 8-CPT-cAMP. By contrast, low concentrations of 4-HNE, niacin and 3-OHBA down-regulated the expression of pro-inflammatory cytokines IL-6 and IL-8. These 4-HNE-induced inhibitory effects were blocked by a cAMP analogue but not by inhibitors of Gβγ -downstream signalling molecules. CONCLUSIONS AND IMPLICATIONS These results revealed that 4-HNE is a strong agonist for GPR109A that induces Gαi -dependent anti-inflammatory and Gβγ -dependent cell death responses. Moreover, the findings indicate that specific intracellular signalling molecules, but not GPR109A, can serve as therapeutic targets to block 4-HNE-induced cell death.
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Affiliation(s)
- Jaya Gautam
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | | | - Sajita Shah
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Jun-Goo Jee
- College of Pharmacy, Kyungpook National University, Daegu, Korea
| | - Eunju Kwon
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Ying Wang
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | - Dong Young Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
| | | | - Jung-Ae Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Korea
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15
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Affiliation(s)
- Niko Kivinen
- Department of Ophthalmology; University of Eastern Finland; Kuopio Finland
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16
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Busch M, Wasmuth S, Spital G, Lommatzsch A, Pauleikhoff D. Activation of the ERK1/2-MAPK Signaling Pathway by Complement Serum in UV-POS-Pretreated ARPE-19 Cells. Ophthalmologica 2018; 239:215-224. [PMID: 29486466 DOI: 10.1159/000486404] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/18/2017] [Indexed: 11/19/2022]
Abstract
BACKGROUND Retinal pigment epithelial (RPE) cells undergo functional changes upon complement stimulation, which play a role in the pathogenesis of age-related macular degeneration (AMD). These effects are in part enhanced by pretreating ARPE-19 cells with UV-irradiated photoreceptor outer segments (UV-POS) in vitro. The aim of this study was to investigate the effects of human complement serum (HCS) treatment on p44/42 mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2 [ERK1/2]) activation in ARPE-19 cells pretreated with UV-POS. METHODS UV-POS-pretreated ARPE-19 cells were stimulated with 5% HCS or heat-inactivated HCS (HI-HCS) as a control. Pro tein expression of phosphorylated (activated) ERK1/2, total ERK1/2, Bax, and Bcl-2 was analyzed by Western blotting. Cell culture supernatants were analyzed for IL-6, IL-8, MCP-1, and VEGF by enzyme-linked immunosorbent assay (ELISA). Furthermore, extra- and intracellular reactive oxygen species (ROS) were determined. RESULTS The amount of phosphorylated ERK1/2 was increased in UV-POS-pretreated ARPE-19 cells, especially in combination with HCS stimulation, compared to non-pretreated ARPE-19 cells incubated with HCS alone or HI-HCS. The same observation was made for Bax and Bcl-2 expression. Furthermore, an increase in extra- and intracellular ROS was detected in UV-POS-pretreated ARPE-19 cells. The ELISA data showed that the production of IL-6, IL-8, and MCP-1 tended to increase in response to HCS in both UV-POS-pretreated and non-pretreated ARPE-19 cells. CONCLUSIONS Our data imply that ERK1/2 activation in ARPE-19 cells may represent a response mechanism to cellular and oxidative stress, associated with apoptosis-regulating factors such as Bax and Bcl-2, which might play a role in AMD, while ERK1/2 seems not to represent the crucial signaling pathway mediating the functional changes in RPE cells in response to complement stimulation.
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Affiliation(s)
- Martin Busch
- Ophtha-Lab, Department of Ophthalmology at St. Franziskus Hospital, Münster, Germany
| | - Susanne Wasmuth
- Ophtha-Lab, Department of Ophthalmology at St. Franziskus Hospital, Münster, Germany
| | - Georg Spital
- Department of Ophthalmology at St. Franziskus Hospital, Münster, Germany
| | - Albrecht Lommatzsch
- Department of Ophthalmology at St. Franziskus Hospital, Münster, Germany.,Department of Ophthalmology, University of Duisburg-Essen, Essen, Germany
| | - Daniel Pauleikhoff
- Department of Ophthalmology at St. Franziskus Hospital, Münster, Germany.,Department of Ophthalmology, University of Duisburg-Essen, Essen, Germany
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Limmongkon A, Janhom P, Amthong A, Kawpanuk M, Nopprang P, Poohadsuan J, Somboon T, Saijeen S, Surangkul D, Srikummool M, Boonsong T. Antioxidant activity, total phenolic, and resveratrol content in five cultivars of peanut sprouts. Asian Pac J Trop Biomed 2017; 7:332-8. [DOI: 10.1016/j.apjtb.2017.01.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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18
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Čolak E, Ignjatović S, Radosavljević A, Žorić L. The association of enzymatic and non-enzymatic antioxidant defense parameters with inflammatory markers in patients with exudative form of age-related macular degeneration. J Clin Biochem Nutr 2017; 60:100-107. [PMID: 28366988 PMCID: PMC5371514 DOI: 10.3164/jcbn.16-30] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 06/26/2016] [Indexed: 02/05/2023] Open
Abstract
There are evidence that oxidative stress and inflammation are involved in the pathogenesis of the age-related macular degeneration (AMD). The aim of this study was to analyze the antioxidant defense parameters and inflammatory markers in patients with exudative form of AMD (eAMD), their mutual correlations and association with the specific forms of AMD. The cross-sectional study, included 75 patients with the eAMD, 31 patients with the early form, and 87 aged-matched control subjects. Significantly lower SOD, TAS and albumin values and higher GR, CRP and IL-6 were found in the eAMD compared to the early form (p<0.05). Significant negative correlations were found between GPx and fibrinogen (r = -0.254), TAS and IL-6 (r = -0.999) and positive correlations between uric acid and CRP (r = 0.292), IL-6 and uric acid (r = 0.398) in the eAMD. A significant association of CRP (OR: 1.16, 95% CI: 1.03-1.32, p = 0.018), fibrinogen (OR: 2.21, 95% CI: 1.14-4.85, p = 0.021), TAS (OR: 7.45, 95% CI: 3.97-14.35, p = 0.0001), albumin (OR: 1.25, 95% CI: 1.11-1.41, p = 0.0001) and uric acid (OR: 1.006, 95% CI: 1.00-1.02, p = 0.003) was found with the eAMD. In conclusion it may be suggested, there is a significant impairment of antioxidant and inflammatory parameter levels in eAMD patients. In addition, significant association exists between the tested inflammatory markers and antioxidant parameters with late-eAMD.
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Affiliation(s)
- Emina Čolak
- Institute of Medical Biochemistry, Clinical Center of Serbia, School of Pharmacy, University of Belgrade, Belgrade 11000, Serbia
| | - Svetlana Ignjatović
- Institute of Medical Biochemistry, Clinical Center of Serbia, School of Pharmacy, University of Belgrade, Belgrade 11000, Serbia
| | - Aleksandra Radosavljević
- Institute of Ophthalmology, Medical Retina Department, Clinical Center of Serbia, School of Medicine, University of Belgrade, Belgrade 11000, Serbia
| | - Lepša Žorić
- Clinic for Eye Diseases, Clinical Center, Faculty of Medicine, Settlement Kosovska Mitrovica, Kosovska Mitrovica 38200, Serbia
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Elbay A, Ozer OF, Akkan JCU, Celik U, Kutlutürk I, Koytak A, Ozdemir H. Comparison of serum thiol–disulphide homeostasis and total antioxidant–oxidant levels between exudative age-related macular degeneration patients and healthy subjects. Int Ophthalmol 2017; 37:1095-101. [DOI: 10.1007/s10792-016-0367-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 09/30/2016] [Indexed: 12/14/2022]
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20
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Kauppinen A, Paterno JJ, Blasiak J, Salminen A, Kaarniranta K. Inflammation and its role in age-related macular degeneration. Cell Mol Life Sci 2016; 73:1765-86. [PMID: 26852158 PMCID: PMC4819943 DOI: 10.1007/s00018-016-2147-8] [Citation(s) in RCA: 437] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 01/05/2023]
Abstract
Inflammation is a cellular response to factors that challenge the homeostasis of cells and tissues. Cell-associated and soluble pattern-recognition receptors, e.g. Toll-like receptors, inflammasome receptors, and complement components initiate complex cellular cascades by recognizing or sensing different pathogen and damage-associated molecular patterns, respectively. Cytokines and chemokines represent alarm messages for leukocytes and once activated, these cells travel long distances to targeted inflamed tissues. Although it is a crucial survival mechanism, prolonged inflammation is detrimental and participates in numerous chronic age-related diseases. This article will review the onset of inflammation and link its functions to the pathogenesis of age-related macular degeneration (AMD), which is the leading cause of severe vision loss in aged individuals in the developed countries. In this progressive disease, degeneration of the retinal pigment epithelium (RPE) results in the death of photoreceptors, leading to a loss of central vision. The RPE is prone to oxidative stress, a factor that together with deteriorating functionality, e.g. decreased intracellular recycling and degradation due to attenuated heterophagy/autophagy, induces inflammation. In the early phases, accumulation of intracellular lipofuscin in the RPE and extracellular drusen between RPE cells and Bruch's membrane can be clinically detected. Subsequently, in dry (atrophic) AMD there is geographic atrophy with discrete areas of RPE loss whereas in the wet (exudative) form there is neovascularization penetrating from the choroid to retinal layers. Elevations in levels of local and systemic biomarkers indicate that chronic inflammation is involved in the pathogenesis of both disease forms.
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Affiliation(s)
- Anu Kauppinen
- Faculty of Health Sciences, School of Pharmacy, University of Eastern Finland, P.O. Box 1627, 70211, Kuopio, Finland.
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland.
| | - Jussi J Paterno
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
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21
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Hytti M, Piippo N, Salminen A, Honkakoski P, Kaarniranta K, Kauppinen A. Quercetin alleviates 4-hydroxynonenal-induced cytotoxicity and inflammation in ARPE-19 cells. Exp Eye Res 2015; 132:208-15. [PMID: 25662315 DOI: 10.1016/j.exer.2015.02.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 01/09/2015] [Accepted: 02/03/2015] [Indexed: 02/01/2023]
Abstract
Retinal pigment epithelium (RPE) plays the principal role in age-related macular degeneration (AMD), a progressive eye disease with no cure and limited therapeutical options. In the pathogenesis of AMD, degeneration of RPE cells by multiple factors including increased oxidative stress and chronic inflammation precedes the irreversible loss of photoreceptors and central vision. Here, we report that the plant-derived polyphenol, quercetin, increases viability and decreases inflammation in stressed human ARPE-19 cells after exposure to the lipid peroxidation end product 4-hydroxynonenal (HNE). Several previous studies have been conducted using the direct oxidant H2O2 but we preferred HNE since natural characteristics predispose RPE cells to the type of oxidative damage evoked by lipid peroxidation. Quercetin improved cell membrane integrity and mitochondrial function as assessed in LDH and MTT tests. Decreased production of proinflammatory mediators IL-6, IL-8, and MCP-1 were indicated at the RNA level by qPCR and at the protein level by the ELISA technique. In addition, we probed the signaling behind the effects and observed that p38 and ERK MAPK pathways, and CREB signaling are regulated by quercetin in ARPE-19 cells. In conclusion, our present data suggests that HNE is highly toxic to serum-starved ARPE-19 cells but quercetin is able to reverse these adverse effects even when administered after an oxidative insult.
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Affiliation(s)
- Maria Hytti
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland.
| | - Niina Piippo
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland.
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland; Department of Neurology, Kuopio University Hospital, P.O.B. 100, FI-70029 KYS, Finland.
| | - Paavo Honkakoski
- School of Pharmacy, Faculty of Health Science, University of Eastern Finland, P.O.B. 1627, FI-70211, Finland.
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, P.O.B. 100, FI-70029 KYS, Finland.
| | - Anu Kauppinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, P.O.B. 100, FI-70029 KYS, Finland.
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22
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Krohne TU, Westenskow PD, Kurihara T, Friedlander DF, Lehmann M, Dorsey AL, Li W, Zhu S, Schultz A, Wang J, Siuzdak G, Ding S, Friedlander M. Generation of retinal pigment epithelial cells from small molecules and OCT4 reprogrammed human induced pluripotent stem cells. Stem Cells Transl Med 2014; 1:96-109. [PMID: 22532929 DOI: 10.5966/sctm.2011-0057] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Autologous retinal pigment epithelium (RPE) grafts derived from induced pluripotent stem cells (iPSCs) may be used to cure blinding diseases in which RPE dysfunction results in photoreceptor degeneration. Four-, two-, and one-factor-derived iPSCs (4F-, 2F-, and 1F-iPSCs, respectively) were differentiated into fully functional cuboidal pigmented cells in polarized monolayers that express RPE-specific markers. 1F-iPSCs-RPE (1F-iPS-RPE) strongly resembles primary human fetal RPE (hfRPE) based on proteomic and untargeted metabolomic analyses, and using novel in vivo imaging technology coupled with electroretinography, we demonstrated that 1F-iPS-RPE mediate anatomical and functional rescue of photoreceptors after transplantation in an animal model of RPE-mediated retinal degeneration. 1F-iPS0RPE cells were injected subretinally as a suspension and formed a monolayer dispersed between host RPE cells. Furthermore, 1F-iPS-RPE do not simply provide trophic support to rescue photoreceptors as previously speculated but actually phagocytose photoreceptor outer segments in vivo and maintain visual cycling. Thus, 1f-iPS-RPE grafts may be superior to conventional iPS-RPE for clinical use because 1F-IPS-RPE closely resemble hfRPE, mediate anatomical and functional photoreceptor rescue in vivo, and are generated using a reduced number of potentially oncogenic reprogramming factors.
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Affiliation(s)
- Tim U Krohne
- Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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McDowell RE, McGeown JG, Stitt AW, Curtis TM. Therapeutic potential of targeting lipid aldehydes and lipoxidation end-products in the treatment of ocular disease. Future Med Chem 2013; 5:189-211. [PMID: 23360143 DOI: 10.4155/fmc.12.202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Lipoxidation reactions and the subsequent accumulation of advanced lipoxidation end products (ALEs) have been implicated in the pathogenesis of many of the leading causes of visual impairment. Here, we begin by outlining some of the major lipid aldehydes produced through lipoxidation reactions, the ALEs formed upon their reaction with proteins, and the endogenous aldehyde metabolizing enzymes involved in protecting cells against lipoxidation mediated damage. Discussions are subsequently focused on the clinical and experimental evidence supporting the contribution of lipid aldehydes and ALEs in the development of ocular diseases. From these discussions, it is clear that inhibition of lipoxidation reactions and ALE formation could represent a new therapeutic avenue for the treatment of a broad range of ocular disorders. Current and emerging pharmacological strategies to prevent or neutralize the effects of lipid aldehydes and ALEs are therefore considered, with particular emphasis on the potential of these drugs for treatment of diseases of the eye.
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24
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Viiri J, Amadio M, Marchesi N, Hyttinen JMT, Kivinen N, Sironen R, Rilla K, Akhtar S, Provenzani A, D'Agostino VG, Govoni S, Pascale A, Agostini H, Petrovski G, Salminen A, Kaarniranta K. Autophagy activation clears ELAVL1/HuR-mediated accumulation of SQSTM1/p62 during proteasomal inhibition in human retinal pigment epithelial cells. PLoS One 2013; 8:e69563. [PMID: 23922739 PMCID: PMC3726683 DOI: 10.1371/journal.pone.0069563] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/10/2013] [Indexed: 12/21/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common reason of visual impairment in the elderly in the Western countries. The degeneration of retinal pigment epithelial cells (RPE) causes secondarily adverse effects on neural retina leading to visual loss. The aging characteristics of the RPE involve lysosomal accumulation of lipofuscin and extracellular protein aggregates called “drusen”. Molecular mechanisms behind protein aggregations are weakly understood. There is intriguing evidence suggesting that protein SQSTM1/p62, together with autophagy, has a role in the pathology of different degenerative diseases. It appears that SQSTM1/p62 is a connecting link between autophagy and proteasome mediated proteolysis, and expressed strongly under the exposure to various oxidative stimuli and proteasomal inhibition. ELAVL1/HuR protein is a post-transcriptional factor, which acts mainly as a positive regulator of gene expression by binding to specific mRNAs whose corresponding proteins are fundamental for key cellular functions. We here show that, under proteasomal inhibitor MG-132, ELAVL1/HuR is up-regulated at both mRNA and protein levels, and that this protein binds and post-transcriptionally regulates SQSTM1/p62 mRNA in ARPE-19 cell line. Furthermore, we observed that proteasomal inhibition caused accumulation of SQSTM1/p62 bound irreversibly to perinuclear protein aggregates. The addition of the AMPK activator AICAR was pro-survival and promoted cleansing by autophagy of the former complex, but not of the ELAVL1/HuR accumulation, indeed suggesting that SQSTM1/p62 is decreased through autophagy-mediated degradation, while ELAVL1/HuR through the proteasomal pathway. Interestingly, when compared to human controls, AMD donor samples show strong SQSTM1/p62 rather than ELAVL1/HuR accumulation in the drusen rich macular area suggesting impaired autophagy in the pathology of AMD.
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Affiliation(s)
- Johanna Viiri
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Marialaura Amadio
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Nicoletta Marchesi
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Juha M. T. Hyttinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Niko Kivinen
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
| | - Reijo Sironen
- Institute of Clinical Medicine, Pathology and Forensic Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Clinical Pathology, Kuopio University Hospital, Kuopio, Finland
- Biocenter Kuopio and Cancer Center of Eastern Finland, University of Eastern Finland, Kuopio, Finland
| | - Kirsi Rilla
- Department of Anatomy, School of Medicine, Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Saeed Akhtar
- Department of Optometry and Vision Sciences College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Alessandro Provenzani
- Laboratory of Genomic Screening, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Vito Giuseppe D'Agostino
- Laboratory of Genomic Screening, Centre for Integrative Biology, University of Trento, Trento, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Hansjurgen Agostini
- Department of Ophthalmology, University Eye Hospital, Albert-Ludwigs University of Freiburg, Freiburg im Breisgau, Germany
| | - Goran Petrovski
- Department of Ophthalmology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
- Stem Cells and Eye Research Laboratory, Department of Biochemistry and Molecular Biology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary
| | - Antero Salminen
- Department of Neurology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, Kuopio, Finland
- * E-mail:
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25
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Kaarniranta K, Sinha D, Blasiak J, Kauppinen A, Veréb Z, Salminen A, Boulton ME, Petrovski G. Autophagy and heterophagy dysregulation leads to retinal pigment epithelium dysfunction and development of age-related macular degeneration. Autophagy 2013; 9:973-84. [PMID: 23590900 PMCID: PMC3722332 DOI: 10.4161/auto.24546] [Citation(s) in RCA: 239] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is a complex, degenerative and progressive eye disease that usually does not lead to complete blindness, but can result in severe loss of central vision. Risk factors for AMD include age, genetics, diet, smoking, oxidative stress and many cardiovascular-associated risk factors. Autophagy is a cellular housekeeping process that removes damaged organelles and protein aggregates, whereas heterophagy, in the case of the retinal pigment epithelium (RPE), is the phagocytosis of exogenous photoreceptor outer segments. Numerous studies have demonstrated that both autophagy and heterophagy are highly active in the RPE. To date, there is increasing evidence that constant oxidative stress impairs autophagy and heterophagy, as well as increases protein aggregation and causes inflammasome activation leading to the pathological phenotype of AMD. This review ties together these crucial pathological topics and reflects upon autophagy as a potential therapeutic target in AMD.
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Affiliation(s)
- Kai Kaarniranta
- Department of Ophthalmology; Institute of Clinical Medicine; University of Eastern Finland; Kuopio, Finland; Department of Ophthalmology; Kuopio University Hospital; Kuopio, Finland
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26
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Pilat A, Herrnreiter AM, Skumatz CMB, Sarna T, Burke JM. Oxidative stress increases HO-1 expression in ARPE-19 cells, but melanosomes suppress the increase when light is the stressor. Invest Ophthalmol Vis Sci 2013; 54:47-56. [PMID: 23221079 DOI: 10.1167/iovs.12-11153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Phagocytized melanosomes in ARPE-19 cells were previously shown to decrease susceptibility to oxidative stress induced by hydrogen peroxide treatment and increase stress due to light irradiation relative to cells containing control black latex beads. Here we asked whether differential expression of antioxidant enzymes in cells containing pigment granules could explain the outcomes. METHODS ARPE-19 cells were loaded by phagocytosis with porcine RPE melanosomes or black latex beads (control particles). Heme oxygenase-1 (HO-1), HO-2, glutathione peroxidase (GPx), and catalase were quantified by Western blot analysis before and after treatment with sublethal hydrogen peroxide or blue light (400-450 nm). The stress was confirmed as sublethal by cell survival analysis using real-time quantification of propidium iodide fluorescence. RESULTS Phagocytosis itself produced transient changes in protein levels of some antioxidant enzymes, but steady-state levels (7 days after phagocytosis) did not differ in cells containing melanosomes versus beads. Sublethal stress, induced by either hydrogen peroxide or light, had no effect on catalase or HO-2 in either particle-free or particle-loaded cells. In contrast, HO-1 protein was upregulated by treatment with both hydrogen peroxide and light. Particle content did not affect the HO-1 increase induced by hydrogen peroxide, but the increase induced by blue light irradiation was partially blocked in cells containing black beads and blocked even more in cells containing melanosomes. CONCLUSIONS The results do not implicate differential antioxidant enzyme levels in stress protection by melanosomes against hydrogen peroxide, but they suggest a multifaceted role for melanosomes in regulating light stress susceptibility in RPE cells.
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Affiliation(s)
- Anna Pilat
- Department of Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Krakow, Poland
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27
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Ebrahimi KB, Handa JT. Lipids, lipoproteins, and age-related macular degeneration. J Lipids 2011; 2011:802059. [PMID: 21822496 DOI: 10.1155/2011/802059] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 04/14/2011] [Accepted: 05/09/2011] [Indexed: 01/31/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly. While excellent treatment has emerged for neovascular disease, treatment for early AMD is lacking due to an incomplete understanding of the early molecular events. A prominent age-related change is the accumulation of neutral lipid in normal Bruch's membrane (BrM) throughout adulthood and also disease-related BrM accumulations called basal deposits and drusen. AMD lesion formation has thus been conceptualized as sharing mechanisms with atherosclerotic plaque formation, where low-density lipoprotein (LDL) retention within the arterial wall initiates a cascade of pathologic events. However, we do not yet understand how lipoproteins contribute to AMD. This paper explores how systemic and local production of lipoproteins might contribute to the pathogenesis of AMD.
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28
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Kishan AU, Modjtahedi BS, Martins EN, Modjtahedi SP, Morse LS. Lipids and age-related macular degeneration. Surv Ophthalmol 2011; 56:195-213. [PMID: 21439604 DOI: 10.1016/j.survophthal.2010.08.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 08/29/2010] [Accepted: 08/31/2010] [Indexed: 01/17/2023]
Abstract
Given the considerable public health burden imposed by age-related macular degeneration (AMD), much effort has been directed towards elucidating principles of pathogenesis in order to identify risk factors and develop preventive measures and treatments. Together with epidemiological evidence linking cardiovascular risk factors with AMD risk and basic science work examining the role of lipid metabolism in AMD, numerous human studies have assayed a potential relationship between dietary lipids and the development of AMD. We examine the evidence for a role for lipid metabolism in AMD, highlighting key basic biochemical principles, work in animal models, and relevant human studies. The topics of lipoprotein modulation and omega-3 fatty acid intake receive special attention from both a basic science and clinical study standpoint. The evidence suggests that consumption of omega-3 fatty acids, perhaps in concert with antioxidants, may constitute a rational preventative strategy against AMD development, though, absent an appropriately developed double-blind, randomized control trial, insufficient data exist to recommend implementation in the clinical setting at this time.
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29
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Stahl A, Krohne TU, Sapieha P, Chen J, Hellstrom A, Chew E, Holz FG, Smith LEH. Lipid metabolites in the pathogenesis and treatment of neovascular eye disease. Br J Ophthalmol 2011; 95:1496-501. [PMID: 21421650 DOI: 10.1136/bjo.2010.194241] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Lipids and lipid metabolites have long been known to play biological roles that go beyond energy storage and membrane structure. In age-related macular degeneration and diabetes, for example, dysregulation of lipid metabolism is closely associated with disease onset and progression. At the same time, some lipids and their metabolites can exert beneficial effects in the same disorders. This review summarises our current knowledge of the contributions of lipids to both the pathogenesis and treatment of neovascular eye disease. The clinical entities covered are exudative age-related macular degeneration, diabetic retinopathy and retinopathy of prematurity, with a special emphasis on the potential therapeutic effects of ω3- (also known as n-3) polyunsaturated fatty acids.
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Affiliation(s)
- Andreas Stahl
- Department of Ophthalmology, Harvard Medical School, Children's Hospital, Boston, Massachusetts 02115, USA
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30
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Qin S, Rodrigues GA. Differential roles of AMPKα1 and AMPKα2 in regulating 4-HNE-induced RPE cell death and permeability. Exp Eye Res 2010; 91:818-24. [PMID: 21029733 DOI: 10.1016/j.exer.2010.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/18/2010] [Accepted: 10/18/2010] [Indexed: 11/30/2022]
Abstract
Lipid peroxidation products such as 4-hydroxy-2-nonenal (4-HNE) cause dysfunction and death of retinal pigmented epithelial (RPE) cells, thereby leading to retinal degeneration. The molecular mechanisms underlying their action remain elusive however. In this study, the roles of AMP-activated protein kinase (AMPK) in 4-HNE-induced RPE cell dysfunction and viability were addressed. 4-HNE caused RPE cell death and down-regulated basal activity of AMPK as evidenced by decreased Thr(172) phosphorylation of AMPKα. Exposure of RPE cells to the AMPK inhibitor, compound C also led to cell death, indicating that RPE cell death is correlated with 4-HNE modulation of AMPK activity. ARPE19 cells express both AMPKα1 and AMPKα2 with predominant expression of the AMPKα1 isoform. siRNA studies revealed that knockdown of AMPKα1 expression sensitized RPE cells to 4-HNE. Intriguingly, knockdown of AMPKα2 protected RPE cells from 4-HNE injury. Sub-lethal doses of 4-HNE induced an increase in RPE monolayer permeability, as measured by reduction in trans-epithelial resistance (TER). Knockdown of AMPKα2 but not AMPKα1 significantly restored RPE cell barrier function. No further protection was observed by knockdown of both AMPKα1 and AMPKα2. In contrast, knockdown of AMPKα1 and/or AMPKα2 did not reverse the 4-HNE's inhibitory effects on production of IL-8 and MCP-1. These data demonstrate that AMPKα1 and AMPKα2 play distinct roles in regulating 4-HNE effects on RPE function and viability. Therefore, selective modulation of AMPKα activity may benefit patients with retinal degeneration associated with RPE cell atrophy.
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Affiliation(s)
- Suofu Qin
- Retinal Disease Research, Department of Biological Sciences, Allergan, Inc., 2525 Dupont Drive, Irvine, CA 92612, USA.
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31
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Wright AF, Chakarova CF, Abd El-Aziz MM, Bhattacharya SS. Photoreceptor degeneration: genetic and mechanistic dissection of a complex trait. Nat Rev Genet 2010; 11:273-84. [PMID: 20212494 DOI: 10.1038/nrg2717] [Citation(s) in RCA: 434] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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32
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Krohne TU, Stratmann NK, Kopitz J, Holz FG. Effects of lipid peroxidation products on lipofuscinogenesis and autophagy in human retinal pigment epithelial cells. Exp Eye Res 2010; 90:465-71. [DOI: 10.1016/j.exer.2009.12.011] [Citation(s) in RCA: 299] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Revised: 12/30/2009] [Accepted: 12/30/2009] [Indexed: 11/19/2022]
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