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Lee HE, Jung M, Choi K, Jang JH, Hwang SK, Chae S, Lee JH, Mun JY. L-serine restored lysosomal failure in cells derived from patients with BPAN reducing iron accumulation with eliminating lipofuscin. Free Radic Biol Med 2024; 221:273-282. [PMID: 38740102 DOI: 10.1016/j.freeradbiomed.2024.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/30/2024] [Accepted: 05/08/2024] [Indexed: 05/16/2024]
Abstract
Defective mitochondria and autophagy, as well as accumulation of lipid and iron in WDR45 mutant fibroblasts, is related to beta-propeller protein-associated neurodegeneration (BPAN). In this study, we found that enlarged lysosomes in cells derived from patients with BPAN had low enzyme activity, and most of the enlarged lysosomes had an accumulation of iron and oxidized lipid. Cryo-electron tomography revealed elongated lipid accumulation, and spectrometry-based elemental analysis showed that lysosomal iron and oxygen accumulation superimposed with lipid aggregates. Lysosomal lipid aggregates superimposed with autofluorescence as free radical generator, lipofuscin. To eliminate free radical stress by iron accumulation in cells derived from patients with BPAN, we investigated the effects of the iron chelator, 2,2'-bipyridine (bipyridyl, BIP). To study whether the defects in patient-derived cells can be rescued by an iron chelator BIP, we tested whether the level of iron and reactive oxygen species (ROS) in the cells and genes related to oxidative stress were rescued BIP treatment. Although BIP treatment decreased some iron accumulation in the cytoplasm and mitochondria, the accumulation of iron in the lysosomes and levels of cellular ROS were unaffected. In addition, the change of specific RNA levels related to free radical stress in patient fibroblasts was not rescued by BIP. To alleviate free radical stress, we investigated whether l-serine can regulate abnormal structures in cells derived from patients with BPAN through the regulation of free radical stress. l-serine treatment alleviated increase of enlarged lysosomes and iron accumulation and rescued impaired lysosomal activity by reducing oxidized lipid accumulation in the lysosomes of the cells. Lamellated lipids in the lysosomes of the cells were identified as lipofuscin through correlative light and electron microscopy, and l-serine treatment reduced the increase of lipofuscin. These data suggest that l-serine reduces oxidative stress-mediated lysosomal lipid oxidation and iron accumulation by rescuing lysosomal activity.
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Affiliation(s)
- Hye Eun Lee
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea; School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Minkyo Jung
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Kiju Choi
- Division of Structural Biology, Baobab AiBIO, Incheon, South Korea
| | - Jae Hyuck Jang
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, South Korea; Electron Microscopy Group for Materials Science, Korea Basic Science Institute, Daejeon, South Korea
| | - Su-Kyeong Hwang
- Department of Pediatrics, School of Medicine, Kyungpook National University, Daegu, South Korea; Astrogen Inc., Techno-Building 313, Kyungpook National University, Daegu, 41566, South Korea
| | - Sehyun Chae
- Division of Chemical Engineering and Bioengineering, College of Art, Culture and Engineering, Kangwon National University, Chuncheon, 24341, South Korea
| | - Jae-Hyeok Lee
- Department of Neurology, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, 50612, South Korea; Medical Research Institute, Pusan National University School of Medicine, Yangsan, 50612, South Korea.
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea.
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Basyal D, Lee S, Kim HJ. Antioxidants and Mechanistic Insights for Managing Dry Age-Related Macular Degeneration. Antioxidants (Basel) 2024; 13:568. [PMID: 38790673 PMCID: PMC11117704 DOI: 10.3390/antiox13050568] [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: 03/18/2024] [Revised: 04/26/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Age-related macular degeneration (AMD) severely affects central vision due to progressive macular degeneration and its staggering prevalence is rising globally, especially in the elderly population above 55 years. Increased oxidative stress with aging is considered an important contributor to AMD pathogenesis despite multifaceted risk factors including genetic predisposition and environmental agents. Wet AMD can be managed with routine intra-vitreal injection of angiogenesis inhibitors, but no satisfactory medicine has been approved for the successful management of the dry form. The toxic carbonyls due to photo-oxidative degradation of accumulated bisretinoids within lysosomes initiate a series of events including protein adduct formation, impaired autophagy flux, complement activation, and chronic inflammation, which is implicated in dry AMD. Therapy based on antioxidants has been extensively studied for its promising effect in reducing the impact of oxidative stress. This paper reviews the dry AMD pathogenesis, delineates the effectiveness of dietary and nutrition supplements in clinical studies, and explores pre-clinical studies of antioxidant molecules, extracts, and formulations with their mechanistic insights.
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Affiliation(s)
| | | | - Hye Jin Kim
- College of Pharmacy, Keimyung University, Dauge 42601, Republic of Korea
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Lewis LLM, Dörschmann P, Seeba C, Thalenhorst T, Roider J, Iloki Assanga SB, Ruiz JCG, Del Castillo Castro T, Rosas-Burgos EC, Plascencia-Jatomea M, Ezquerra Brauer JM, Klettner A. Properties of Cephalopod Skin Ommochromes to Inhibit Free Radicals, and the Maillard Reaction and Retino-Protective Mechanisms in Cellular Models Concerning Oxidative Stress, Angiogenesis, and Inflammation. Antioxidants (Basel) 2022; 11:antiox11081574. [PMID: 36009293 PMCID: PMC9404994 DOI: 10.3390/antiox11081574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022] Open
Abstract
Ommochromes are pigments of invertebrates that exhibit oxidative stress protection. The aim of this study was to investigate ommochromes extracted from cephalopod’s skin for their ability to inhibit age-related-macular degeneration (AMD)-related factors such as H2O2-induced and iron-dependent oxidative stress (ferroptosis and erastin), accumulation of advanced glycation end-products (AGEs), as well as vascular endothelial growth factor (VEGF), and inflammatory cytokines (interleukin 6 and interleukin 8) secretion. As cell systems, we used primary porcine retinal pigment epithelium (RPE), human retinal pigment epithelium cell line ARPE-19 and uveal melanoma cell line OMM-1. In vitro, ommochromes produced an antiglycation effect by the inhibition of fructosylation reaction. The ommochromes showed protective effects against erastin- induced cell death in ARPE-19. In addition, in long-term stimulation (7 days) ommochromes decreased constitutively secreted VEGF, as well as interleukin 6 and interleukin 8 induced by Poly I:C in primary RPE. No relevant effects were detected in OMM-1 cells. The effects are dependent on the cell system, time of exposition, and concentration. This substance is of interest for further research concerning age-related macular degeneration.
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Affiliation(s)
- Luján Lidianys María Lewis
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Philipp Dörschmann
- Department of Ophthalmology, University of Kiel, University Medical Center, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany
| | - Charlotte Seeba
- Department of Ophthalmology, University of Kiel, University Medical Center, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany
| | - Tabea Thalenhorst
- Department of Ophthalmology, University of Kiel, University Medical Center, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany
| | - Johann Roider
- Department of Ophthalmology, University of Kiel, University Medical Center, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany
| | - Simon Bernard Iloki Assanga
- Department of Biological Chemical Sciences, Sonora University, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Juan Carlos Gálvez Ruiz
- Department of Biological Chemical Sciences, Sonora University, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Teresa Del Castillo Castro
- Department of Research on Polymers and Materials, Sonora University, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Ema Carina Rosas-Burgos
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Maribel Plascencia-Jatomea
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Josafat Marina Ezquerra Brauer
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo 83000, Sonora, Mexico
| | - Alexa Klettner
- Department of Ophthalmology, University of Kiel, University Medical Center, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany
- Correspondence: ; Tel.: +49-431-500-24283
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Han H, Nakaoka HJ, Hofmann L, Zhou JJ, Yu C, Zeng L, Nan J, Seo G, Vargas RE, Yang B, Qi R, Bardwell L, Fishman DA, Cho KWY, Huang L, Luo R, Warrior R, Wang W. The Hippo pathway kinases LATS1 and LATS2 attenuate cellular responses to heavy metals through phosphorylating MTF1. Nat Cell Biol 2022; 24:74-87. [PMID: 35027733 PMCID: PMC9022944 DOI: 10.1038/s41556-021-00813-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 11/08/2021] [Indexed: 12/11/2022]
Abstract
Heavy metals are both integral parts of cells and environmental toxicants, and their deregulation is associated with severe cellular dysfunction and various diseases. Here we show that the Hippo pathway plays a critical role in regulating heavy metal homeostasis. Hippo signalling deficiency promotes the transcription of heavy metal response genes and protects cells from heavy metal-induced toxicity, a process independent of its classic downstream effectors YAP and TAZ. Mechanistically, the Hippo pathway kinase LATS phosphorylates and inhibits MTF1, an essential transcription factor in the heavy metal response, resulting in the loss of heavy metal response gene transcription and cellular protection. Moreover, LATS activity is inhibited following heavy metal treatment, where accumulated zinc directly binds and inhibits LATS. Together, our study reveals an interplay between the Hippo pathway and heavy metals, providing insights into this growth-related pathway in tissue homeostasis and stress response.
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Affiliation(s)
- Han Han
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Hiroki J Nakaoka
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Line Hofmann
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Jeff Jiajing Zhou
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Clinton Yu
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Lisha Zeng
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Junyu Nan
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Gayoung Seo
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | | | - Bing Yang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Ruxi Qi
- Cryo-EM Center, Southern University of Science and Technology, Shenzhen, China
| | - Lee Bardwell
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Dmitry A Fishman
- Department of Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Ken W Y Cho
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Ray Luo
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, Irvine, CA, USA
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Rahul Warrior
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA.
| | - Wenqi Wang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, USA.
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Álvarez-Barrios A, Álvarez L, García M, Artime E, Pereiro R, González-Iglesias H. Antioxidant Defenses in the Human Eye: A Focus on Metallothioneins. Antioxidants (Basel) 2021; 10:89. [PMID: 33440661 PMCID: PMC7826537 DOI: 10.3390/antiox10010089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
The human eye, the highly specialized organ of vision, is greatly influenced by oxidants of endogenous and exogenous origin. Oxidative stress affects all structures of the human eye with special emphasis on the ocular surface, the lens, the retina and its retinal pigment epithelium, which are considered natural barriers of antioxidant protection, contributing to the onset and/or progression of eye diseases. These ocular structures contain a complex antioxidant defense system slightly different along the eye depending on cell tissue. In addition to widely studied enzymatic antioxidants, including superoxide dismutase, glutathione peroxidase, catalase, peroxiredoxins and selenoproteins, inter alia, metallothioneins (MTs) are considered antioxidant proteins of growing interest with further cell-mediated functions. This family of cysteine rich and low molecular mass proteins captures and neutralizes free radicals in a redox-dependent mechanism involving zinc binding and release. The state of the art of MTs, including the isoforms classification, the main functions described to date, the Zn-MT redox cycle as antioxidant defense system, and the antioxidant activity of Zn-MTs in the ocular surface, lens, retina and its retinal pigment epithelium, dependent on the number of occupied zinc-binding sites, will be comprehensively reviewed.
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Affiliation(s)
- Ana Álvarez-Barrios
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Lydia Álvarez
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Montserrat García
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
| | - Enol Artime
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Rosario Pereiro
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
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Nagakannan P, Tabeshmehr P, Eftekharpour E. Oxidative damage of lysosomes in regulated cell death systems: Pathophysiology and pharmacologic interventions. Free Radic Biol Med 2020; 157:94-127. [PMID: 32259579 DOI: 10.1016/j.freeradbiomed.2020.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 12/16/2022]
Abstract
Lysosomes are small specialized organelles containing a variety of different hydrolase enzymes that are responsible for degradation of all macromolecules, entering the cells through the endosomal system or originated from the internal sources. This allows for transport and recycling of nutrients and internalization of surface proteins for antigen presentation as well as maintaining cellular homeostasis. Lysosomes are also important storage compartments for metal ions and nutrients. The integrity of lysosomal membrane is central to maintaining their normal function, but like other cellular membranes, lysosomal membrane is subject to damage mediated by reactive oxygen species. This results in spillage of lysosomal enzymes into the cytoplasm, leading to proteolytic damage to cellular systems and organelles. Several forms of lysosomal dependent cell death have been identified in diseases. Examination of these events are important for finding treatment strategies relevant to cancer or neurodegenerative diseases as well as autoimmune deficiencies. In this review, we have examined the current literature on involvement of lysosomes in induction of programed cell death and have provided an extensive list of therapeutic approaches that can modulate cell death. Exploitation of these mechanisms can lead to novel therapies for cancer and neurodegenerative diseases.
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Affiliation(s)
- Pandian Nagakannan
- Regenerative Medicine Program and Spinal Cord Research Centre, Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Parisa Tabeshmehr
- Regenerative Medicine Program and Spinal Cord Research Centre, Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Eftekhar Eftekharpour
- Regenerative Medicine Program and Spinal Cord Research Centre, Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada.
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Dörschmann P, Mikkelsen MD, Thi TN, Roider J, Meyer AS, Klettner A. Effects of a Newly Developed Enzyme-Assisted Extraction Method on the Biological Activities of Fucoidans in Ocular Cells. Mar Drugs 2020; 18:E282. [PMID: 32466624 PMCID: PMC7344579 DOI: 10.3390/md18060282] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/20/2020] [Accepted: 05/25/2020] [Indexed: 12/26/2022] Open
Abstract
Fucoidans from brown seaweeds are promising substances as potential drugs against age-related macular degeneration (AMD). The heterogeneity of fucoidans requires intensive research in order to find suitable species and extraction methods. Ten different fucoidan samples extracted enzymatically from Laminaria digitata (LD), Saccharina latissima (SL) and Fucus distichus subsp. evanescens (FE) were tested for toxicity, oxidative stress protection and VEGF (vascular endothelial growth factor) inhibition. For this study crude fucoidans were extracted from seaweeds using different enzymes and SL fucoidans were further separated into three fractions (SL_F1-F3) by ion-exchange chromatography (IEX). Fucoidan composition was analyzed by high performance anion exchange chromatography (HPAEC) after acid hydrolysis. The crude extracts contained alginate, while two of the fractionated SL fucoidans SL_F2 and SL_F3 were highly pure. Cell viability was assessed with an 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay in OMM-1 and ARPE-19. Protective effects were investigated after 24 h of stress insult in OMM-1 and ARPE-19. Secreted VEGF was analyzed via ELISA (enzyme-linked immunosorbent assay) in ARPE-19 cells. Fucoidans showed no toxic effects. In OMM-1 SL_F2 and several FE fucoidans were protective. LD_SiAT2 (Cellic®CTec2 + Sigma-Aldrich alginate lyase), FE_SiAT3 (Cellic® CTec3 + Sigma-Aldrich alginate lyase), SL_F2 and SL_F3 inhibited VEGF with the latter two as the most effective. We could show that enzyme treated fucoidans in general and the fractionated SL fucoidans SL_F2 and SL_F3 are very promising for beneficial AMD relevant biological activities.
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Affiliation(s)
- Philipp Dörschmann
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany; (J.R.); (A.K.)
| | - Maria Dalgaard Mikkelsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kongens Lyngby, Denmark; (M.D.M.); (T.N.T.); (A.S.M.)
| | - Thuan Nguyen Thi
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kongens Lyngby, Denmark; (M.D.M.); (T.N.T.); (A.S.M.)
| | - Johann Roider
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany; (J.R.); (A.K.)
| | - Anne S. Meyer
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kongens Lyngby, Denmark; (M.D.M.); (T.N.T.); (A.S.M.)
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany; (J.R.); (A.K.)
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Cathepsin B pH-Dependent Activity Is Involved in Lysosomal Dysregulation in Atrophic Age-Related Macular Degeneration. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:5637075. [PMID: 31885803 PMCID: PMC6925809 DOI: 10.1155/2019/5637075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/11/2019] [Accepted: 11/05/2019] [Indexed: 12/16/2022]
Abstract
Age-related macular degeneration (AMD) is characterized by retinal pigment epithelial (RPE) cell dysfunction beginning at early stages of the disease. The lack of an appropriate in vitro model is a major limitation in understanding the mechanisms leading to the occurrence of AMD. This study compared human-induced pluripotent stem cell- (hiPSC-) RPE cells derived from atrophic AMD patients (77 y/o ± 7) to hiPSC-RPE cells derived from healthy elderly individuals with no drusen or pigmentary alteration (62.5 y/o ± 17.5). Control and AMD hiPSC-RPE cell lines were characterized by immunofluorescence, flow cytometry, and electronic microscopy. The toxicity level of iron after Fe-NTA treatment was evaluated by an MTT test and by the detection of dichloro-dihydro-fluorescein diacetate. Twelve hiPSC-RPE cell lines (6 AMD and 6 controls) were used for the experiment. Under basal conditions, all hiPSC-RPE cells expressed a phenotypic profile of senescent cells with rounded mitochondria at passage 2. However, the treatment with Fe-NTA induced higher reactive oxygen species production and cell death in hiPSC-RPE AMD cells than in hiPSC-RPE Control cells. Interestingly, functional analysis showed differences in lysosomal activity between the two populations. Indeed, Cathepsin B activity was higher in hiPSC-RPE AMD cells compared to hiPSC-RPE Control cells in basal condition and link to a pH more acidic in this cell population. Moreover, oxidative stress exposure leads to an increase of Cathepsin D immature form levels in both populations, but in a higher proportion in hiPSC-RPE AMD cells. These findings could demonstrate that hiPSC-RPE AMD cells have a typical disease phenotype compared to hiPSC-RPE Control cells.
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Dörschmann P, Kopplin G, Roider J, Klettner A. Effects of Sulfated Fucans from Laminaria hyperborea Regarding VEGF Secretion, Cell Viability, and Oxidative Stress and Correlation with Molecular Weight. Mar Drugs 2019; 17:E548. [PMID: 31557816 PMCID: PMC6835690 DOI: 10.3390/md17100548] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 09/13/2019] [Accepted: 09/23/2019] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Sulfated fucans show interesting effects in the treatment of ocular diseases (e.g., age-related macular degeneration), depending on their chemical structure. Here, we compared three purified sulfated fucans from Laminaria hyperborea (LH) regarding cell viability, oxidative stress protection, and vascular endothelial growth factor (VEGF) secretion in ocular cells. METHODS High-molecular-weight sulfated fucan (Mw = 1548.6 kDa, Fuc1) was extracted with warm water and purified through ultrafiltration. Lower-molecular-weight samples (Mw = 499 kDa, Fuc2; 26.9 kDa, Fuc3) were obtained by mild acid hydrolysis of ultrapurified sulfated fucan and analyzed (SEC-MALS (Size-exclusion chromatography-Multi-Angle Light Scattering), ICP-MS, and GC). Concentrations between 1 and 100 µg/mL were tested. Cell viability was measured after 24 h (uveal melanoma cell line (OMM-1), retinal pigment epithelium (RPE) cell line ARPE-19, primary RPE cells) via MTT/MTS (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide/3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Oxidative stress protection was determined after 24 h (OMM-1, ARPE-19). VEGF secretion was analyzed via ELISA after three days (ARPE-19, RPE). RESULTS Fuc2 and Fuc3 were antiproliferative for OMM-1, but not for ARPE. Fuc1 protected OMM-1. VEGF secretion was lowered with all fucans except Fuc3 in ARPE-19 and RPE. The results suggest a correlation between molecular weight and biological activity, with efficiency increasing with size. CONCLUSION The LH sulfated fucan Fuc1 showed promising results regarding VEGF inhibition and protection, encouraging further medical research.
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Affiliation(s)
- Philipp Dörschmann
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
| | - Georg Kopplin
- Alginor ASA, Haraldsgata 162, 5525 Haugesund, Norway.
- Norwegian Biopolymer Laboratory (NOBIPOL), Department of Biotechnology and Food Science, NTNU, 7491 Trondheim, Norway.
| | - Johann Roider
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
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Dörschmann P, Bittkau KS, Neupane S, Roider J, Alban S, Klettner A. Effects of Fucoidans from Five Different Brown Algae on Oxidative Stress and VEGF Interference in Ocular Cells. Mar Drugs 2019; 17:E258. [PMID: 31052228 PMCID: PMC6562460 DOI: 10.3390/md17050258] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Fucoidans are interesting for potential usage in ophthalmology, and especially age-related macular degeneration. However, fucoidans from different species may vary in their effects. Here, we compare fucoidans from five algal species in terms of oxidative stress protection and vascular endothelial growth factor (VEGF) interference in ocular cells. METHODS Brown algae (Fucus vesiculosus, Fucus distichus subsp. evanescens, Fucus serratus, Laminaria digitata, Saccharina latissima) were harvested and fucoidans isolated by hot-water extraction. Fucoidans were tested in several concentrations (1, 10, 50, and 100 µg/mL). Effects were measured on a uveal melanoma cell line (OMM-1) (oxidative stress), retinal pigment epithelium (RPE) cell line ARPE19 (oxidative stress and VEGF), and primary RPE cells (VEGF). Oxidative stress was induced by H2O2 or tert-Butyl hydroperoxide (TBHP). Cell viability was investigated with methyl thiazolyl tetrazolium (MTT or MTS) assay, and VEGF secretion with ELISA. Affinity to VEGF was determined by a competitive binding assay. RESULTS All fucoidans protected OMM-1 from oxidative stress. However, in ARPE19, only fucoidan from Saccharina latissima was protective. The affinity to VEGF of all fucoidans was stronger than that of heparin, and all reduced VEGF secretion in ARPE19. In primary RPE, only the fucoidan from Saccharina latissima was effective. CONCLUSION Among the fucoidans from five different species, Saccharina latissima displayed the most promising results concerning oxidative stress protection and reduction of VEGF secretion.
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Affiliation(s)
- Philipp Dörschmann
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
| | - Kaya Saskia Bittkau
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Kiel, Gutenbergstraße 76, 24118 Kiel, Germany.
| | - Sandesh Neupane
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Kiel, Gutenbergstraße 76, 24118 Kiel, Germany.
| | - Johann Roider
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
| | - Susanne Alban
- Department of Pharmaceutical Biology, Pharmaceutical Institute, University of Kiel, Gutenbergstraße 76, 24118 Kiel, Germany.
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Arnold-Heller-Str. 3, Haus 25, 24105 Kiel, Germany.
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Reactive Oxygen Species-Mediated Damage of Retinal Neurons: Drug Development Targets for Therapies of Chronic Neurodegeneration of the Retina. Int J Mol Sci 2018; 19:ijms19113362. [PMID: 30373222 PMCID: PMC6274960 DOI: 10.3390/ijms19113362] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 10/18/2018] [Accepted: 10/19/2018] [Indexed: 02/06/2023] Open
Abstract
The significance of oxidative stress in the development of chronic neurodegenerative diseases of the retina has become increasingly apparent in recent years. Reactive oxygen species (ROS) are free radicals produced at low levels as a result of normal cellular metabolism that are ultimately metabolized and detoxified by endogenous and exogenous mechanisms. In the presence of oxidative cellular stress, ROS are produced in excess, resulting in cellular injury and death and ultimately leading to tissue and organ dysfunction. Recent studies have investigated the role of excess ROS in the pathogenesis and development of chronic neurodegenerative diseases of the retina including glaucoma, diabetic retinopathy, and age-related macular degeneration. Findings from these studies are promising insofar as they provide clear rationales for innovative treatment and prevention strategies of these prevalent and disabling diseases where currently therapeutic options are limited. Here, we briefly outline recent developments that have contributed to our understanding of the role of ROS in the pathogenesis of chronic neurodegenerative diseases of the retina. We then examine and analyze the peer-reviewed evidence in support of ROS as targets for therapy development in the area of chronic neurodegeneration of the retina.
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