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Fontaine V, Boumedine T, Monteiro E, Fournié M, Gersende G, Sahel JA, Picaud S, Veillet S, Lafont R, Latil M, Dilda PJ, Camelo S. RAR Inhibitors Display Photo-Protective and Anti-Inflammatory Effects in A2E Stimulated RPE Cells In Vitro through Non-Specific Modulation of PPAR or RXR Transactivation. Int J Mol Sci 2024; 25:3037. [PMID: 38474284 PMCID: PMC10932305 DOI: 10.3390/ijms25053037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/23/2024] [Accepted: 03/02/2024] [Indexed: 03/14/2024] Open
Abstract
N-retinylidene-N-retinylethanolamine (A2E) has been associated with age-related macular degeneration (AMD) physiopathology by inducing cell death, angiogenesis and inflammation in retinal pigmented epithelial (RPE) cells. It was previously thought that the A2E effects were solely mediated via the retinoic acid receptor (RAR)-α activation. However, this conclusion was based on experiments using the RAR "specific" antagonist RO-41-5253, which was found to also be a ligand and partial agonist of the peroxisome proliferator-activated receptor (PPAR)-γ. Moreover, we previously reported that inhibiting PPAR and retinoid X receptor (RXR) transactivation with norbixin also modulated inflammation and angiogenesis in RPE cells challenged in the presence of A2E. Here, using several RAR inhibitors, we deciphered the respective roles of RAR, PPAR and RXR transactivations in an in vitro model of AMD. We showed that BMS 195614 (a selective RAR-α antagonist) displayed photoprotective properties against toxic blue light exposure in the presence of A2E. BMS 195614 also significantly reduced the AP-1 transactivation and mRNA expression of the inflammatory interleukin (IL)-6 and vascular endothelial growth factor (VEGF) induced by A2E in RPE cells in vitro, suggesting a major role of RAR in these processes. Surprisingly, however, we showed that (1) Norbixin increased the RAR transactivation and (2) AGN 193109 (a high affinity pan-RAR antagonist) and BMS 493 (a pan-RAR inverse agonist), which are photoprotective against toxic blue light exposure in the presence of A2E, also inhibited PPARs transactivation and RXR transactivation, respectively. Therefore, in our in vitro model of AMD, several commercialized RAR inhibitors appear to be non-specific, and we propose that the phototoxicity and expression of IL-6 and VEGF induced by A2E in RPE cells operates through the activation of PPAR or RXR rather than by RAR transactivation.
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Affiliation(s)
- Valérie Fontaine
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Thinhinane Boumedine
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Elodie Monteiro
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Mylène Fournié
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Gendre Gersende
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
- Fondation Ophtalmologique Rothschild, 29 rue Manin, 75019 Paris, France
- Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Serge Picaud
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 Rue Moreau, 75012 Paris, France; (V.F.); (T.B.); (M.F.); (J.-A.S.); (S.P.)
| | - Stanislas Veillet
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - René Lafont
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Mathilde Latil
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Pierre J. Dilda
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
| | - Serge Camelo
- Biophytis, Sorbonne Université, BC9, 4 place Jussieu, 75005 Paris, France (M.L.); (P.J.D.)
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Lyu Y, Tschulakow AV, Wang K, Brash DE, Schraermeyer U. Chemiexcitation and melanin in photoreceptor disc turnover and prevention of macular degeneration. Proc Natl Acad Sci U S A 2023; 120:e2216935120. [PMID: 37155898 PMCID: PMC10194005 DOI: 10.1073/pnas.2216935120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 04/03/2023] [Indexed: 05/10/2023] Open
Abstract
Age-related macular degeneration, Stargardt disease, and their Abca4-/- mouse model are characterized by accelerated accumulation of the pigment lipofuscin, derived from photoreceptor disc turnover in the retinal pigment epithelium (RPE); lipofuscin accumulation and retinal degeneration both occur earlier in albino mice. Intravitreal injection of superoxide (O2•-) generators reverses lipofuscin accumulation and rescues retinal pathology, but neither the target nor mechanism is known. Here we show that RPE contains thin multi-lamellar membranes (TLMs) resembling photoreceptor discs, which associate with melanolipofuscin granules in pigmented mice but in albinos are 10-fold more abundant and reside in vacuoles. Genetically over-expressing tyrosinase in albinos generates melanosomes and decreases TLM-related lipofuscin. Intravitreal injection of generators of O2•- or nitric oxide (•NO) decreases TLM-related lipofuscin in melanolipofuscin granules of pigmented mice by ~50% in 2 d, but not in albinos. Prompted by evidence that O2•- plus •NO creates a dioxetane on melanin that excites its electrons to a high-energy state (termed "chemiexcitation"), we show that exciting electrons directly using a synthetic dioxetane reverses TLM-related lipofuscin even in albinos; quenching the excited-electron energy blocks this reversal. Melanin chemiexcitation assists in safe photoreceptor disc turnover.
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Affiliation(s)
- Yanan Lyu
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen72076, Germany
| | - Alexander V. Tschulakow
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen72076, Germany
- OcuTox GmbH, Preclinical Drug Assessment, Hechingen72379, Germany
| | - Kun Wang
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen72076, Germany
| | - Douglas E. Brash
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT06520-8040
- Yale Comprehensive Cancer Center, Yale University School of Medicine, New Haven, CT06520-8028
| | - Ulrich Schraermeyer
- Division of Experimental Vitreoretinal Surgery, Centre for Ophthalmology, University of Tuebingen, Tuebingen72076, Germany
- OcuTox GmbH, Preclinical Drug Assessment, Hechingen72379, Germany
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Brash DE, Goncalves LCP. Chemiexcitation: Mammalian Photochemistry in the Dark †. Photochem Photobiol 2023; 99:251-276. [PMID: 36681894 PMCID: PMC10065968 DOI: 10.1111/php.13781] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 01/18/2023] [Indexed: 01/23/2023]
Abstract
Light is one way to excite an electron in biology. Another is chemiexcitation, birthing a reaction product in an electronically excited state rather than exciting from the ground state. Chemiexcited molecules, as in bioluminescence, can release more energy than ATP. Excited states also allow bond rearrangements forbidden in ground states. Molecules with low-lying unoccupied orbitals, abundant in biology, are particularly susceptible. In mammals, chemiexcitation was discovered to transfer energy from excited melanin, neurotransmitters, or hormones to DNA, creating the lethal and carcinogenic cyclobutane pyrimidine dimer. That process was initiated by nitric oxide and superoxide, radicals triggered by ultraviolet light or inflammation. Several poorly understood chronic diseases share two properties: inflammation generates those radicals across the tissue, and cells that die are those containing melanin or neuromelanin. Chemiexcitation may therefore be a pathogenic event in noise- and drug-induced deafness, Parkinson's disease, and Alzheimer's; it may prevent macular degeneration early in life but turn pathogenic later. Beneficial evolutionary selection for excitable biomolecules may thus have conferred an Achilles heel. This review of recent findings on chemiexcitation in mammalian cells also describes the underlying physics, biochemistry, and potential pathogenesis, with the goal of making this interdisciplinary phenomenon accessible to researchers within each field.
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Affiliation(s)
- Douglas E. Brash
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT 06520-8040, USA
- Yale Cancer Center, Yale School of Medicine, New Haven, CT 06520-8028, USA
| | - Leticia C. P. Goncalves
- Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT 06520-8040, USA
- Institut de Chimie de Nice CNRS UMR7272, Université Côte d’Azur, 28 Avenue Valrose 06108 Nice, France
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Characterizing the Mechanisms of Metalaxyl, Bronopol and Copper Sulfate against Saprolegnia parasitica Using Modern Transcriptomics. Genes (Basel) 2022; 13:genes13091524. [PMID: 36140692 PMCID: PMC9498376 DOI: 10.3390/genes13091524] [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: 08/04/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022] Open
Abstract
Saprolegniasis, which is caused by Saprolegnia parasitica, leads to considerable economic losses. Recently, we showed that metalaxyl, bronopol and copper sulfate are good antimicrobial agents for aquaculture. In the current study, the efficacies of metalaxyl, bronopol and copper sulfate are evaluated by in vitro antimicrobial experiments, and the mechanism of action of these three antimicrobials on S. parasitica is explored using transcriptome technology. Finally, the potential target genes of antimicrobials on S. parasitica are identified by protein–protein interaction network analysis. Copper sulfate had the best inhibitory effect on S. parasitica, followed by bronopol. A total of 1771, 723 and 2118 DEGs upregulated and 1416, 319 and 2161 DEGs downregulated S. parasitica after three drug treatments (metalaxyl, bronopol and copper sulfate), separately. Additionally, KEGG pathway analysis also determined that there were 17, 19 and 13 significantly enriched metabolic pathways. PPI network analysis screened out three important proteins, and their corresponding genes were SPRG_08456, SPRG_03679 and SPRG_10775. Our results indicate that three antimicrobials inhibit S. parasitica growth by affecting multiple biological functions, including protein synthesis, oxidative stress, lipid metabolism and energy metabolism. Additionally, the screened key genes can be used as potential target genes of chemical antimicrobial drugs for S. parasitica.
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Molins B, Mesquida M, Adan A. Bioengineering approaches for modelling retinal pathologies of the outer blood-retinal barrier. Prog Retin Eye Res 2022:101097. [PMID: 35840488 DOI: 10.1016/j.preteyeres.2022.101097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 05/31/2022] [Accepted: 06/29/2022] [Indexed: 11/18/2022]
Abstract
Alterations of the junctional complex of the outer blood-retinal barrier (oBRB), which is integrated by the close interaction of the retinal pigment epithelium, the Bruch's membrane, and the choriocapillaris, contribute to the loss of neuronal signalling and subsequent vision impairment in several retinal inflammatory disorders such as age-related macular degeneration and diabetic retinopathy. Reductionist approaches into the mechanisms that underlie such diseases have been hindered by the absence of adequate in vitro models using human cells to provide the 3D dynamic architecture that enables expression of the in vivo phenotype of the oBRB. Conventional in vitro cell models are based on 2D monolayer cellular cultures, unable to properly recapitulate the complexity of living systems. The main drawbacks of conventional oBRB models also emerge from the cell sourcing, the lack of an appropriate Bruch's membrane analogue, and the lack of choroidal microvasculature with flow. In the last years, the advent of organ-on-a-chip, bioengineering, and stem cell technologies is providing more advanced 3D models with flow, multicellularity, and external control over microenvironmental properties. By incorporating additional biological complexity, organ-on-a-chip devices can mirror physiologically relevant properties of the native tissue while offering additional set ups to model and study disease. In this review we first examine the current understanding of oBRB biology as a functional unit, highlighting the coordinated contribution of the different components to barrier function in health and disease. Then we describe recent advances in the use of pluripotent stem cells-derived retinal cells, Bruch's membrane analogues, and co-culture techniques to recapitulate the oBRB. We finally discuss current advances and challenges of oBRB-on-a-chip technologies for disease modelling.
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Affiliation(s)
- Blanca Molins
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain.
| | - Marina Mesquida
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Roche Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Alfredo Adan
- Group of Ocular Inflammation: Clinical and Experimental Studies, Institut d'Investigacions Biomèdiques Agustí Pi I Sunyer (IDIBAPS), C/ Sabino de Arana 1, 08028, Barcelona, Spain; Instituto Clínic de Oftalmología, Hospital Clínic Barcelona, C/ Sabino de Arana 1, 08028, Barcelona, Spain
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Molecular mechanism of ethanol fermentation inhibition via protein tyrosine nitration of pyruvate decarboxylase by reactive nitrogen species in yeast. Sci Rep 2022; 12:4664. [PMID: 35304512 PMCID: PMC8933545 DOI: 10.1038/s41598-022-08568-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 03/10/2022] [Indexed: 11/09/2022] Open
Abstract
Protein tyrosine nitration (PTN), in which tyrosine (Tyr) residues on proteins are converted into 3-nitrotyrosine (NT), is one of the post-translational modifications mediated by reactive nitrogen species (RNS). Many recent studies have reported that PTN contributed to signaling systems by altering the structures and/or functions of proteins. This study aimed to investigate connections between PTN and the inhibitory effect of nitrite-derived RNS on fermentation ability using the yeast Saccharomyces cerevisiae. The results indicated that RNS inhibited the ethanol production of yeast cells with increased intracellular pyruvate content. We also found that RNS decreased the activities of pyruvate decarboxylase (PDC) as a critical enzyme involved in ethanol production. Our proteomic analysis revealed that the main PDC isozyme Pdc1 underwent the PTN modification at Tyr38, Tyr157, and Tyr344. The biochemical analysis using the recombinant purified Pdc1 enzyme indicated that PTN at Tyr157 or Tyr344 significantly reduced the Pdc1 activity. Interestingly, the substitution of Tyr157 or Tyr344 to phenylalanine, which is no longer converted into NT, recovered the ethanol production under the RNS treatment conditions. These findings suggest that nitrite impairs the fermentation ability of yeast by inhibiting the Pdc1 activity via its PTN modification at Tyr157 and Tyr344 of Pdc1.
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Zhang D, Robinson K, Washington I. C20D3-Vitamin A Prevents Retinal Pigment Epithelium Atrophic Changes in a Mouse Model. Transl Vis Sci Technol 2021; 10:8. [PMID: 34878528 PMCID: PMC8662574 DOI: 10.1167/tvst.10.14.8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Purpose This study aimed to evaluate the contribution of vitamin A dimerization to retinal pigment epithelium (RPE) atrophic changes. Leading causes of irreversible blindness, including Stargardt disease and age-related macular degeneration (AMD), occur as a result of atrophic changes in RPE. The cause of the RPE atrophic changes is not apparent. During the vitamin A cycle, vitamin A dimerizes, leading to vitamin A cycle byproducts, such as vitamin A dimers, in the RPE. Methods To study the consequence of vitamin A dimerization to RPE atrophic changes, we used a rodent model with accelerated vitamin A dimerization, Abca4−/−/Rdh8−/− mice, and the vitamin A analog C20D3-vitamin A to selectively ameliorate the accelerated rate of vitamin A dimerization. Results We show that ameliorating the rate of vitamin A dimerization with C20D3-vitamin A mitigates pathological changes observed in the prodromal phase of the most prevalent retinal degenerative diseases, including fundus autofluorescence changes, dark adaptation delays, and signature RPE atrophic changes. Conclusions Data demonstrate that the dimerization of vitamin A during the vitamin A cycle is sufficient alone to cause the prerequisite RPE atrophic changes thought to be responsible for the leading causes of irreversible blindness and that correcting the dimerization rate with C20D3-vitamin A may be sufficient to prevent the RPE atrophic changes. Translational Relevance Preventing the dimerization of vitamin A with the vitamin A analog C20D3-vitamin A may be sufficient to alter the clinical course of the most prevalent forms of blindness, including Stargardt disease and age-related macular degeneration (AMD).
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Affiliation(s)
- Dan Zhang
- Columbia University Medical Center, Ophthalmology, New York, NY, USA
| | - Kiera Robinson
- Columbia University Medical Center, Ophthalmology, New York, NY, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY, USA.,biOOrg3.14, Buffalo, WY, USA
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Zhang D, Mihai DM, Washington I. Vitamin A cycle byproducts explain retinal damage and molecular changes thought to initiate retinal degeneration. Biol Open 2021; 10:273577. [PMID: 34842275 PMCID: PMC8649638 DOI: 10.1242/bio.058600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/03/2021] [Indexed: 01/24/2023] Open
Abstract
In the most prevalent retinal diseases, including Stargardt disease and age-related macular degeneration (AMD), byproducts of vitamin A form in the retina abnormally during the vitamin A cycle. Despite evidence of their toxicity, whether these vitamin A cycle byproducts contribute to retinal disease, are symptoms, beneficial, or benign has been debated. We delivered a representative vitamin A byproduct, A2E, to the rat's retina and monitored electrophysiological, histological, proteomic, and transcriptomic changes. We show that the vitamin A cycle byproduct is sufficient alone to damage the RPE, photoreceptor inner and outer segments, and the outer plexiform layer, cause the formation of sub-retinal debris, alter transcription and protein synthesis, and diminish retinal function. The presented data are consistent with the theory that the formation of vitamin A byproducts during the vitamin A cycle is neither benign nor beneficial but may be sufficient alone to cause the most prevalent forms of retinal disease. Retarding the formation of vitamin A byproducts could potentially address the root cause of several retinal diseases to eliminate the threat of irreversible blindness for millions of people. Summary: During the vitamin A cycle, byproducts of vitamin A form in the eye. Using a rat model, we show that the byproducts alone can explain several retinal derangements observed in the prodromal phase of human retinal disease. Retarding the formation of these byproducts may address the root cause of the most prevalent retinal diseases.
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Affiliation(s)
- Dan Zhang
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Doina M Mihai
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA.,biOOrg3.14, Buffalo, WY 82834, USA
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A2E-induced inflammation and angiogenesis in RPE cells in vitro are modulated by PPAR-α, -β/δ, -γ, and RXR antagonists and by norbixin. Aging (Albany NY) 2021; 13:22040-22058. [PMID: 34544906 PMCID: PMC8507260 DOI: 10.18632/aging.203558] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 09/03/2021] [Indexed: 12/15/2022]
Abstract
N-retinylidene-N-retinylethanolamine (A2E) plays a central role in age-related macular degeneration (AMD) by inducing angiogenesis and inflammation. A2E effects are mediated at least partly via the retinoic acid receptor (RAR)-α. Here we show that A2E binds and transactivates also peroxisome proliferator-activated receptors (PPAR) and retinoid X receptors (RXR). 9’-cis-norbixin, a di-apocarotenoid is also a ligand of these nuclear receptors (NR). Norbixin inhibits PPAR and RXR transactivation induced by A2E. Moreover, norbixin reduces protein kinase B (AKT) phosphorylation, NF-κB and AP-1 transactivation and mRNA expression of the inflammatory interleukins (IL) -6 and -8 and of vascular endothelial growth factor (VEGF) enhanced by A2E. By contrast, norbixin increases matrix metalloproteinase 9 (MMP9) and C-C motif chemokine ligand 2 (CCL2) mRNA expression in response to A2E. Selective PPAR-α, -β/δ and –γ antagonists inhibit the expression of IL-6 and IL-8 while only the antagonist of PPAR-γ inhibits the transactivation of NF-κB following A2E exposure. In addition, a cocktail of all three PPARs antagonists and also HX531, an antagonist of RXR reproduce norbixin effects on inflammation. Altogether, A2E’s deleterious biological effects could be inhibited through PPAR and RXR regulation. Moreover, the modulation of these NR by norbixin may open new avenues for the treatment of AMD.
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Ramazan ZK, Sarı İ, Yıldırım BG, Güntürk İ, Küçük E, Erşan S, Seydel GŞ. The Evaluation of oxidative stress, 3-nitrotyrosine, and HMGB-1 levels in patients with Wet Type Age-Related Macular Degeneration. J Med Biochem 2021; 41:275-281. [PMID: 36042902 PMCID: PMC9375537 DOI: 10.5937/jomb0-32189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 08/19/2021] [Indexed: 11/04/2022] Open
Abstract
Background This study aims to compare serum HMGB-1, 3-nitrotyrosine (3-NT), TAS, TOS, and OSI levels in Wettype Age-Related Macular Degeneration (wAMD) patients and healthy controls to determine the correlation of these parameters with each other. Methods Thirty patients with Wet-type Age-Related Macular Degeneration (wAMD) and 27 healthy adults, as controls were enrolled in the study. We determined the TAS and TOS levels in serum samples of both groups using commercial kits on a microplate reader. Serum HMGB-1 and 3-NT levels were measured with the enzyme-linked immunosorbent assay method. Results HMGB-1 levels were significantly higher in the patient group (137.51 pg/mL, p=0.001), while there was no difference between the two groups in serum 3-NT levels (p=0.428). A statistically significant difference found in the levels of TOS and OSI (p=0.001 and p=0.045, respectively) between the patients and controls, however, no significant difference was observed between the groups in terms of TAS levels (p=0.228). Conclusions Oxidative stress and HMGB-1 levels were increased in wAMD patients and enhanced oxidative stress may be associated with increased tissue necrosis and inflammation. Thus administration of antioxidant treatment in addition to routine therapy should be considered in wAMD.
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Affiliation(s)
- Zor Kürşad Ramazan
- Niğde Ömer Halisdemir University School of Medicine Department of Ophthalmology, Bor Yolu, Niğde, Turkey
| | - İsmail Sarı
- Niğde Ömer Halisdemir University School of Medicine Department of Biochemistry, Bor Yolu, Niğde, Turkey
| | - Biçer Gamze Yıldırım
- Niğde Ömer Halisdemir University School of Medicine Department of Ophthalmology, Bor Yolu, Niğde, Turkey
| | - İnayet Güntürk
- Niğde Ömer Halisdemir University, Healthcare Services, Zübeyde Hanım Health Services Vocational High School, Bor Yolu, Niğde, Turkey
| | - Erkut Küçük
- Niğde Ömer Halisdemir University School of Medicine Department of Ophthalmology, Bor Yolu, Niğde, Turkey
| | - Serpil Erşan
- Niğde Ömer Halisdemir University School of Medicine Department of Biochemistry, Bor Yolu, Niğde, Turkey
| | - Gönül Şeyda Seydel
- Niğde Ömer Halisdemir University School of Medicine Department of Medical Biochemistry, Bor Yolu, Niğde, Turkey
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Vitamin A cycle byproducts impede dark adaptation. J Biol Chem 2021; 297:101074. [PMID: 34391781 PMCID: PMC8427233 DOI: 10.1016/j.jbc.2021.101074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 08/02/2021] [Accepted: 08/11/2021] [Indexed: 11/21/2022] Open
Abstract
Impaired dark adaptation (DA), a defect in the ability to adjust to dimly lit settings, is a universal hallmark of aging. However, the mechanisms responsible for impaired DA are poorly understood. Vitamin A byproducts, such as vitamin A dimers, are small molecules that form in the retina during the vitamin A cycle. We show that later in life, in the human eye, these byproducts reach levels commensurate with those of vitamin A. In mice, selectively inhibiting the formation of these byproducts, with the investigational drug C20D3-vitamin A, results in faster DA. In contrast, acutely increasing these ocular byproducts through exogenous delivery leads to slower DA, with otherwise preserved retinal function and morphology. Our findings reveal that vitamin A cycle byproducts alone are sufficient to cause delays in DA and suggest that they may contribute to universal age-related DA impairment. Our data further indicate that the age-related decline in DA may be tractable to pharmacological intervention by C20D3-vitamin A.
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Yu G, Gao SQ, Dong Z, Sheng L, Sun D, Zhang N, Zhang J, Margeivicus S, Fu P, Golczak M, Maeda A, Palczewski K, Lu ZR. Peptide Derivatives of Retinylamine Prevent Retinal Degeneration with Minimal Side Effects on Vision in Mice. Bioconjug Chem 2021; 32:572-583. [PMID: 33677964 DOI: 10.1021/acs.bioconjchem.1c00043] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Safe and effective molecular therapeutics for prophylactic treatment of retinal degenerative diseases are greatly needed. Disruptions in the clearance of all-trans-retinal (atRAL) by the visual (retinoid) cycle of the retina can lead to the accumulation of atRAL and its condensation products known to initiate progressive retinal dystrophy. Retinylamine (Ret-NH2) and its analogues are known to be effective in lowering the concentration of atRAL within the eye and thus preventing retinal degeneration in mouse models of human retinopathies. Here, we chemically modified Ret-NH2 with amino acids and peptides to improve the stability and ocular bioavailability of the resulting derivatives and to minimize their side effects. Fourteen Ret-NH2 derivatives were synthesized and tested in vitro and in vivo. These derivatives exhibited structure-dependent therapeutic efficacy in preventing light-induced retinal degeneration in Abca4-/-Rdh8-/- double-knockout mice, with the compounds containing glycine and/or L-valine generally exhibiting greater protective effects than Ret-NH2 or other tested amino acid derivatives of Ret-NH2. Ret-NH2-L-valylglycine amide (RVG) exhibited good stability in storage; and effective uptake and prolonged retention in mouse eyes. RVG readily formed a Schiff base with atRAL and did not inhibit RPE65 enzymatic activity. Administered by oral gavage, this retinoid also provided effective protection against light-induced retinal degeneration in Abca4-/-Rdh8-/- mice. Notably, the treatment with RVG had minimal effects on the regeneration of 11-cis-retinal and recovery of retinal function. RVG holds promise as a lead therapy for effective and safe treatment of human retinal degenerative diseases.
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Affiliation(s)
- Guanping Yu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Song-Qi Gao
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Zhiqian Dong
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Li Sheng
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Da Sun
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Ning Zhang
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Jianye Zhang
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Seunghee Margeivicus
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Pingfu Fu
- Department of Epidemiology and Biostatistics, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Akiko Maeda
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States.,Department of Ophthalmology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Krzysztof Palczewski
- Center for Translation Vision Research, Gavin Herbert Eye Institute, Departments of Ophthalmology, Physiology & Biophysics, and Chemistry, University of California, Irvine, California 92697, United States
| | - Zheng-Rong Lu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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13
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Hou XW, Wang Y, Pan CW. Metabolomics in Age-Related Macular Degeneration: A Systematic Review. Invest Ophthalmol Vis Sci 2020; 61:13. [PMID: 33315052 PMCID: PMC7735950 DOI: 10.1167/iovs.61.14.13] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/25/2020] [Indexed: 12/22/2022] Open
Abstract
Purpose Age-related macular degeneration (AMD) is one of the leading causes of blindness among the elderly, and the exact pathogenesis of the AMD remains unclear. The purpose of this review is to summarize potential metabolic biomarkers and pathways of AMD that might facilitate risk predictions and clinical diagnoses of AMD. Methods We obtained relevant publications of metabolomics studies of human beings by systematically searching the MEDLINE (PubMed) database before June 2020. Studies were included if they performed mass spectrometry-based or nuclear magnetic resonance-based metabolomics approach for humans. In addition, AMD was assessed from fundus photographs based on standardized protocols. The metabolic pathway analysis was performed using MetaboAnalyst 3.0. Results Thirteen studies were included in this review. Repeatedly identified metabolites including phenylalanine, adenosine, hypoxanthine, tyrosine, creatine, citrate, carnitine, proline, and maltose have the possibility of being biomarkers of AMD. Validation of the biomarker panels was observed in one study. Dysregulation of metabolic pathways involves lipid metabolism, carbohydrate metabolism, nucleotide metabolism, amino acid metabolism, and translation, which might play important roles in the development and progression of AMD. Conclusions This review summarizes the potential metabolic biomarkers and pathways related to AMD, providing opportunities for the construction of diagnostic or predictive models for AMD and the discovery of new therapeutic targets.
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Affiliation(s)
- Xiao-Wen Hou
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Ying Wang
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Chen-Wei Pan
- School of Public Health, Medical College of Soochow University, Suzhou, China
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14
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Eamegdool SS, Sitiwin EI, Cioanca AV, Madigan MC. Extracellular matrix and oxidative stress regulate human retinal pigment epithelium growth. Free Radic Biol Med 2020; 146:357-371. [PMID: 31751761 DOI: 10.1016/j.freeradbiomed.2019.11.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 11/01/2019] [Accepted: 11/13/2019] [Indexed: 11/23/2022]
Abstract
Age-related macular degeneration (AMD), the most common cause of vision loss with ageing, is characterised by degeneration of the photoreceptors and retinal pigment epithelium (RPE) and changes in the extracellular matrix (ECM) underlying the RPE. The pathogenesis of AMD is still not fully understood. In this study we investigated the in vitro growth and function of primary human RPE cells in response to different ECM substrates, including nitrite-modified ECM. We initially confirmed the presence of disorganised retinal glial and photoreceptor cells, marked retinal cytoplasmic and Bruch's membrane expression of nitro-tyrosine (an oxidative stress marker) and increased numbers of Iba1+ macrophages/microglia in human donor eye sections (aged and AMD) using multi-marker immunohistochemistry (n = 3). Concurrently, we utilised two-photon microscopy to reveal topographical changes in flatmounts of RPE-associated ECM and in the underlying choroid of aged and AMD donor eyes (n = 3). To recapitulate these observations in vitro, we then used primary human RPE cells to investigate how different ECM proteins, including nitrite cross-linked RPE-secreted ECM, modified RPE cell growth and function. Collagen I or IV increased RPE attachment and spreading two-to three-fold, associated with significantly increased cell migration and proliferation, consistent with a preferential interaction with these matrix substrates. Primary human RPE cells grown on collagen I and IV also showed increased secretion of pro-inflammatory cytokines, MCP-1 and IL-8. Nitrite-modification of RPE-secreted ECM (simulating ageing of Bruch's membrane) significantly reduced in vitro RPE attachment to the ECM and this was mitigated with collagen IV coating of the modified ECM. Taken together, our observations confirm the importance of RPE-ECM interactions for normal RPE growth and function, and for inducing RPE secretion of pro-inflammatory cytokines. Furthermore, the findings are consistent with ageing and/or oxidative stress-induced disruption of RPE-ECM interactions contributing to the pathogenesis of AMD.
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Affiliation(s)
- Steven S Eamegdool
- Save Sight Institute, University of Sydney, 2000, Australia; Eye Genetics Research Unit, Children's Medical Research Institute, 2145, Australia.
| | - Ephrem I Sitiwin
- Save Sight Institute, University of Sydney, 2000, Australia; School of Optometry and Vision Science, UNSW, 2052, Australia; Biomedical Imaging Facility, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Adrian V Cioanca
- Save Sight Institute, University of Sydney, 2000, Australia; The John Curtin School of Medical Research, The Australian National University, Canberra, ACT, 2601, Australia.
| | - Michele C Madigan
- Save Sight Institute, University of Sydney, 2000, Australia; School of Optometry and Vision Science, UNSW, 2052, Australia.
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15
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Gong J, Cai H, Noggle S, Paull D, Rizzolo LJ, Del Priore LV, Fields MA. Stem cell-derived retinal pigment epithelium from patients with age-related macular degeneration exhibit reduced metabolism and matrix interactions. Stem Cells Transl Med 2019; 9:364-376. [PMID: 31840941 PMCID: PMC7031648 DOI: 10.1002/sctm.19-0321] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022] Open
Abstract
Modeling age‐related macular degeneration (AMD) is challenging, because it is a multifactorial disease. To focus on interactions between the retinal pigment epithelium (RPE) and Bruch's membrane, we generated RPE from AMD patients and used an altered extracellular matrix (ECM) that models aged Bruch's membrane. Induced pluripotent stem cells (iPSCs) were generated from fibroblasts isolated from AMD patients or age‐matched (normal) controls. RPE derived from iPSCs were analyzed by morphology, marker expression, transepithelial electrical resistance (TER), and phagocytosis of rod photoreceptor outer segments. Cell attachment and viability was tested on nitrite‐modified ECM, a typical modification of aged Bruch's membrane. DNA microarrays with hierarchical clustering and analysis of mitochondrial function were used to elucidate possible mechanisms for the observed phenotypes. Differentiated RPE displayed cell‐specific morphology and markers. The TER and phagocytic capacity were similar among iPSC‐derived RPE cultures. However, distinct clusters were found for the transcriptomes of AMD and control iPSC‐derived RPE. AMD‐derived iPSC‐RPE downregulated genes responsible for metabolic‐related pathways and cell attachment. AMD‐derived iPSC‐RPE exhibited reduced mitochondrial respiration and ability to attach and survive on nitrite‐modified ECM. Cells that did attach induced the expression of complement genes. Despite reprogramming, iPSC derived from AMD patients yielded RPE with a transcriptome that is distinct from that of age‐matched controls. When challenged with an AMD‐like modification of Bruch's membrane, AMD‐derived iPSC‐RPE activated the complement immune system.
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Affiliation(s)
- Jie Gong
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut
| | - Hui Cai
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut
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- The New York Stem Cell Foundation (NYSCF) Research Institute, New York, New York
| | - Scott Noggle
- The New York Stem Cell Foundation (NYSCF) Research Institute, New York, New York
| | - Daniel Paull
- The New York Stem Cell Foundation (NYSCF) Research Institute, New York, New York
| | - Lawrence J Rizzolo
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut.,Department of Surgery, Yale University School of Medicine, New Haven, Connecticut
| | - Lucian V Del Priore
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut
| | - Mark A Fields
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut
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16
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Cai H, Gong J, Abriola L, Hoyer D, NYSCF Global Stem Cell Array Team, Noggle S, Paull D, Del Priore LV, Fields MA. High-throughput screening identifies compounds that protect RPE cells from physiological stressors present in AMD. Exp Eye Res 2019; 185:107641. [DOI: 10.1016/j.exer.2019.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 03/12/2019] [Accepted: 04/06/2019] [Indexed: 12/30/2022]
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17
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Biswal MR, Justis BD, Han P, Li H, Gierhart D, Dorey CK, Lewin AS. Daily zeaxanthin supplementation prevents atrophy of the retinal pigment epithelium (RPE) in a mouse model of mitochondrial oxidative stress. PLoS One 2018; 13:e0203816. [PMID: 30265681 PMCID: PMC6161850 DOI: 10.1371/journal.pone.0203816] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/28/2018] [Indexed: 01/04/2023] Open
Abstract
Oxidative damage is implicated in the pathogenesis of age-related macular degeneration (AMD). The dry form of AMD (geographic atrophy) is characterized by loss of RPE, photoreceptors, and macular pigments. The cumulative effects of oxidative stress impact mitochondrial function in RPE. In Sod2flox/floxVMD2-cre mice, the RPE specific deletion of Sod2, the gene for mitochondrial manganese superoxide dismutase (MnSOD), leads to elevated oxidative stress in retina and RPE, and causes changes in the RPE and underlying Bruch's membrane that share some features of AMD. This study tested the hypothesis that zeaxanthin supplementation would reduce oxidative stress and preserve RPE structure and function in these mice. Zeaxanthin in retina/RPE/choroid and liver was quantified by LC/MS, retinal function and structure were evaluated by electroretinogram (ERG) and spectral domain optical coherence tomography (SD-OCT), and antioxidant gene expression was measured by RT-PCR. After one month of supplementation, zeaxanthin levels were 5-fold higher in the retina/RPE/choroid and 12-fold higher in liver than in unsupplemented control mice. After four months of supplementation, amplitudes of the ERG a-wave (function of rod photoreceptors) and b-wave (function of the inner retina) were not different in supplemented and control mice. In contrast, the c-wave amplitude (a measure of RPE function) was 28% higher in supplemented mice than in control mice. Higher RPE/choroid expression of antioxidant genes (Cat, Gstm1, Hmox1, Nqo1) and scaffolding protein Sqstm1 were found in supplemented mice than in unsupplemented controls. Reduced nitrotyrosine content in the RPE/choroid was demonstrated by ELISA. Preliminary assessment of retinal ultrastructure indicated that supplementation supported better preservation of RPE structure with more compact basal infoldings and intact mitochondria. We conclude that daily zeaxanthin supplementation protected RPE cells from mitochondrial oxidative stress associated with deficiency in the MnSOD and thereby improved RPE function early in the disease course.
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Affiliation(s)
- Manas R. Biswal
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States of America
- Center for Vision Research, University of Florida, Gainesville, FL, United States of America
- College of Pharmacy, University of South Florida, Tampa, United States of America
- * E-mail:
| | - Bradley D. Justis
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Pingyang Han
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Hong Li
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | | | - Cheryl K. Dorey
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, United States of America
| | - Alfred S. Lewin
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL, United States of America
- Center for Vision Research, University of Florida, Gainesville, FL, United States of America
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, FL, United States of America
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18
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Thao MT, Karumanchi DK, Yacout SM, Gaillard ER. Nitrite ion modifies tyrosine and lysine residues of extracellular matrix proteins. Nitric Oxide 2018; 79:51-56. [PMID: 30055286 DOI: 10.1016/j.niox.2018.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/26/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
Age-related macular degeneration (AMD) is a disease characterized by degenerative changes in the retinal pigment epithelium and Bruch's membrane. Inflammation is considered a major risk factor for the development and progression of AMD. Nitrite is a potent byproduct of inflammation and has been detected at elevated concentrations in AMD donor tissue. We hypothesize that nitrite chemically modifies the extracellular matrix (ECM) of Bruch's membrane as an initial step to degenerative changes observed in AMD. Non-enzymatically nitrated synthetic ECM peptides, fibronectin and laminin, were used as model systems for inflammation. Using LC/MS, we identified that nitration preferentially occurred on tyrosine and deamination of lysine under the studied conditions. At tyrosine residues, 3-nitrotyrosine was produced and shifted the total mass by the addition of 45 amu. Deamination of lysine occurred and resulted in the formation of either an alkene or alcohol group. The alkene group was observed with a loss of 17 amu. An addition of 1 amu was observed with alcohol formation. We hypothesize that these initial chemical modifications to the structure of ECM proteins may be the responsible for altering the structure and consequent function of Bruch's membrane.
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Affiliation(s)
- Mai T Thao
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, USA
| | | | - Sally M Yacout
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, USA
| | - Elizabeth R Gaillard
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, USA; Department of Biological Sciences, Northern Illinois University, DeKalb, IL, USA.
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19
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Brash DE, Goncalves LCP, Bechara EJH. Chemiexcitation and Its Implications for Disease. Trends Mol Med 2018; 24:527-541. [PMID: 29751974 DOI: 10.1016/j.molmed.2018.04.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/27/2018] [Accepted: 04/06/2018] [Indexed: 12/20/2022]
Abstract
Quantum mechanics rarely extends to molecular medicine. Recently, the pigment melanin was found to be susceptible to chemiexcitation, in which an electron is chemically excited to a high-energy molecular orbital. In invertebrates, chemiexcitation causes bioluminescence; in mammals, a higher-energy process involving melanin transfers energy to DNA without photons, creating the lethal and mutagenic cyclobutane pyrimidine dimer that can cause melanoma. This process is initiated by NO and O2- radicals, the formation of which can be triggered by ultraviolet light or inflammation. Several chronic diseases share two properties: inflammation generates these radicals across the tissue, and the diseased cells lie near melanin. We propose that chemiexcitation may be an upstream event in numerous human diseases.
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Affiliation(s)
- Douglas E Brash
- Departments of Therapeutic Radiology and Dermatology, and Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520-8040, USA.
| | - Leticia C P Goncalves
- Departments of Therapeutic Radiology and Dermatology, and Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520-8040, USA
| | - Etelvino J H Bechara
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo 05513-970 SP, and Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Diadema, São Paulo 09972-270 SP, Brazil
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20
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Krilis M, Qi M, Madigan MC, Wong JWH, Abdelatti M, Guymer RH, Whitelock J, McCluskey P, Zhang P, Qi J, Hunyor AP, Krilis SA, Giannakopoulos B. Nitration of tyrosines in complement factor H domains alters its immunological activity and mediates a pathogenic role in age related macular degeneration. Oncotarget 2018; 8:49016-49032. [PMID: 28159936 PMCID: PMC5564745 DOI: 10.18632/oncotarget.14940] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 12/27/2016] [Indexed: 11/25/2022] Open
Abstract
Nitrosative stress has been implicated in the pathogenesis of age related macular degeneration (AMD). Tyrosine nitration is a unique type of post translational modification that occurs in the setting of inflammation and nitrosative stress. To date, the significance and functional implications of tyrosine nitration of complement factor H (CFH), a key complement regulator in the eye has not been explored, and is examined in this study in the context of AMD pathogenesis. Sections of eyes from deceased individuals with AMD (n = 5) demonstrated the presence of immunoreactive nitrotyrosine CFH. We purified nitrated CFH from retinae from 2 AMD patients. Mass spectrometry of CFH isolated from AMD eyes revealed nitrated residues in domains critical for binding to heparan sulphate glycosaminoglycans (GAGs), lipid peroxidation by-products and complement (C) 3b. Functional studies revealed that nitrated CFH did not bind to lipid peroxidation products, nor to the GAG of perlecan nor to C3b. There was loss of cofactor activity for Factor I mediated cleavage of C3b with nitrated CFH compared to non-nitrated CFH. CFH inhibits, but nitrated CFH significantly potentiates, the secretion of the pro-inflammatory and angiogenic cytokine IL-8 from monocytes that have been stimulated with lipid peroxidation by-products. AMD patients (n = 30) and controls (n = 30) were used to measure plasma nitrated CFH using a novel ELISA. AMD patients had significantly elevated nitrated CFH levels compared to controls (p = 0.0117). These findings strongly suggest that nitrated CFH contributes to AMD progression, and is a target for therapeutic intervention.
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Affiliation(s)
- Matthew Krilis
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, Sydney, NSW, Australia
| | - Miao Qi
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia
| | - Michele C Madigan
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, Sydney, NSW, Australia.,School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
| | - Jason W H Wong
- Prince of Wales Clinical School, University of New South Wales, Lowy Cancer Research Centre, Sydney, NSW, Australia
| | - Mahmoud Abdelatti
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - John Whitelock
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Peter McCluskey
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, Sydney, NSW, Australia
| | - Peng Zhang
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia.,Department of Cardiothoracic Surgery, Tianjin Medical University General Hospital, Tianjin, China
| | - Jian Qi
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia
| | - Alex P Hunyor
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, Sydney, NSW, Australia
| | - Steven A Krilis
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia
| | - Bill Giannakopoulos
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, NSW, Australia.,Department of Rheumatology, St George Hospital, Sydney, NSW, Australia
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21
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Shin Y, Moiseyev G, Petrukhin K, Cioffi CL, Muthuraman P, Takahashi Y, Ma JX. A novel RPE65 inhibitor CU239 suppresses visual cycle and prevents retinal degeneration. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2420-2429. [PMID: 29684583 DOI: 10.1016/j.bbadis.2018.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/02/2018] [Accepted: 04/17/2018] [Indexed: 01/25/2023]
Abstract
The retinoid visual cycle is an ocular retinoid metabolism specifically dedicated to support vertebrate vision. The visual cycle serves not only to generate light-sensitive visual chromophore 11-cis-retinal, but also to clear toxic byproducts of normal visual cycle (i.e. all-trans-retinal and its condensation products) from the retina, ensuring both the visual function and the retinal health. Unfortunately, various conditions including genetic predisposition, environment and aging may attribute to a functional decline of the all-trans-retinal clearance. To combat all-trans-retinal mediated retinal degeneration, we sought to slow down the retinoid influx from the RPE by inhibiting the visual cycle with a small molecule. The present study describes identification of CU239, a novel non-retinoid inhibitor of RPE65, a key enzyme in the visual cycle. Our data demonstrated that CU239 selectively inhibited isomerase activity of RPE65, with IC50 of 6 μM. Further, our results indicated that CU239 inhibited RPE65 via competition with its substrate all-trans-retinyl ester. Mice with systemic injection of CU239 exhibited delayed chromophore regeneration after light bleach, and conferred a partial protection of the retina against injury from high intensity light. Taken together, CU239 is a potent visual cycle modulator and may have a therapeutic potential for retinal degeneration.
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Affiliation(s)
- Younghwa Shin
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
| | - Konstantin Petrukhin
- Department of Ophthalmology, Columbia University, New York, NY 10032, United States
| | - Christopher L Cioffi
- Departments of Basic & Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - Parthasarathy Muthuraman
- Departments of Basic & Clinical Sciences and Pharmaceutical Sciences, Albany College of Pharmacy and Health Sciences, Albany, NY 12208, United States
| | - Yusuke Takahashi
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United states
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
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22
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Cai H, Gong J, Del Priore LV, Tezel TH, Fields MA. Culturing of Retinal Pigment Epithelial Cells on an Ex Vivo Model of Aged Human Bruch's Membrane. J Vis Exp 2018. [PMID: 29708536 PMCID: PMC5933494 DOI: 10.3791/57084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aside from vitamins and antioxidants recommended by the Age-Related Eye Disease Study, there is no effective therapy for "dry," or atrophic age-related macular degeneration (AMD) which represents 90% of the cases. Therapies are needed to slow or retard the development of geographic atrophy (GA), and understanding Bruch's membrane pathology is part of this process. Alterations in human Bruch's membrane precede the progression of AMD by contributing to the damage of retinal pigment epithelial (RPE) cells. Given the lack of sufficient animal models to study AMD, ex vivo models of aged human Bruch's membrane serve as a useful tool to study the behavior of RPE cells from immortalized and primary cell lines as well as RPE lines derived from induced pluripotent stem cells (iPSCs). Here, we present a detailed method that allows one to determine the effects of RPE cell behavior seeded on harvested human Bruch's membrane explants from human donors, including attachment, apoptosis and proliferation, ability to phagocytize photoreceptor outer segments, establishment of polarity, and gene expression. This assay provides an ex vivo model of aged Bruch's membrane to assess the functional characteristics of RPE cells when seeded on aged/compromised extracellular matrix.
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Affiliation(s)
- Hui Cai
- Department of Ophthalmology and Visual Science, Yale School of Medicine
| | - Jie Gong
- Department of Ophthalmology and Visual Science, Yale School of Medicine
| | | | - Tongalp H Tezel
- Edward S. Harkness Eye Institute, Columbia University School of Medicine
| | - Mark A Fields
- Department of Ophthalmology and Visual Science, Yale School of Medicine;
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23
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Inhibition of Peroxynitrite-Induced Mitophagy Activation Attenuates Cerebral Ischemia-Reperfusion Injury. Mol Neurobiol 2018; 55:6369-6386. [DOI: 10.1007/s12035-017-0859-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Accepted: 12/20/2017] [Indexed: 12/21/2022]
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Wang H, Sun Q, Zhou Y, Zhang H, Luo C, Xu J, Dong Y, Wu Y, Liu H, Wang W. Nitration-mediated deficiency of cystathionine β-synthase activity accelerates the progression of hyperhomocysteinemia. Free Radic Biol Med 2017; 113:519-529. [PMID: 29102635 DOI: 10.1016/j.freeradbiomed.2017.10.389] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 10/08/2017] [Accepted: 10/31/2017] [Indexed: 01/07/2023]
Abstract
Deficiency of cystathionine β-synthase (CBS) activity is the most common cause of increased homocysteine (Hcy). However, until now the underlying mechanisms why CBS activity decreased still remain unresolved. The goal of this study was to explore the contribution of nitrative stress to deficiency of CBS activity, and further identify the possible nitration sites of CBS protein. Results showed that in elderly people, there was an increased nitrative stress level, which was relative to elevated Hcy level. In natural aging rats and diet-induced hyperhomocysteinemia (HHcy) rats, the levels of Hcy and nitrative stress were both elevated, and interestingly, pretreatment with peroxynitrite (ONOO-) scavenger FeTMPyP ameliorated the elevation of Hcy as well as nitrative stress. Further experiments showed the reduction of CBS bioactivity and elevation of CBS nitration in two rats models were both reversed by FeTMPyP pretreatment. In vitro, replacement of tyrosine (Tyr, Y) residue (Tyr163, Tyr223, Tyr381, Tyr518) in CBS with alanine (Ala, A) abolished the Hcy-mediated CBS inactivation. These results highlighted that deficiency of CBS activity was correlated with the nitration of CBS at Tyr163, Tyr223, Tyr381 and Tyr518, which may play a mutual role in the progression of HHcy. This discovery may shed a novel light on the pathogenesis of HHcy and provide a possible gene therapy target to HHcy.
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Affiliation(s)
- Huanyuan Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Department of Traditional Chinese Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
| | - Qi Sun
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Yi Zhou
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Hui Zhang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Chenghua Luo
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Jiahui Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Yu Dong
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Ye Wu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Huirong Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China
| | - Wen Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China; Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Beijing 100069, China.
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Extracellular matrix nitration alters growth factor release and activates bioactive complement in human retinal pigment epithelial cells. PLoS One 2017; 12:e0177763. [PMID: 28505174 PMCID: PMC5432172 DOI: 10.1371/journal.pone.0177763] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/03/2017] [Indexed: 12/18/2022] Open
Abstract
Purpose We have shown previously that non-enzymatic nitration (NEN) of the extracellular matrix (ECM), which serves as a model of Bruch’s membrane (BM) aging, has a profound effect on the behavior of the overlying retinal pigment epithelial (RPE) cells, including altered phagocytic ability, reduced cell adhesion, and inhibition of proliferation. We know that transplanted RPE monolayers will encounter a hostile sub-RPE environment, including age-related alterations in BM that may compromise cell function and survival. Here we use our previous NEN model of BM aging to determine the effects of NEN of the ECM on growth factor release and complement activation in RPE cells. Methods Human induced-pluripotent stem cells (iPSCs) were differentiated into RPE cells, and confirmed by immunohistochemistry, confocal microscopy, and polymerase chain reaction. IPSC-derived RPE cells were plated onto RPE-derived ECM under untreated or nitrite-modified conditions. Cells were cultured for 7 days and barrier function measured by transepithelial resistance (TER). Vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), and complement component C3a were measured using enzyme-linked immunosorbent assay (ELISA). Results On average nitrite-modified ECM increased VEGF release both apically and basally by 0.15 ± 0.014 ng/mL (p <0.0001) and 0.21 ± 0.022 ng/mL (p <0.0001), respectively, in iPSC-derived RPE cells. Nitrite-modified ECM increased PEDF release in iPSC-derived RPE cells apically by 0.16 ± 0.031 ng/mL (p <0.0001), but not basally (0.27 ± 0.015 vs. 0.32 ± 0.029 ng/mL, (p >0.05)). Nitrite-modified ECM increased production of C3a in iPSC-derived RPE cells by 0.52 ± 0.123 ng/mL (p <0.05). Conclusion Nitrite-modified ECM increased VEGF, PEDF release, and C3a production in human iPSC-derived RPE cells. This model demonstrates changes seen in the basement membrane can lead to alterations in the cell biology of the RPE cells that may be related to the development of age-related macular degeneration.
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Washington I, Saad L. The Rate of Vitamin A Dimerization in Lipofuscinogenesis, Fundus Autofluorescence, Retinal Senescence and Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:347-53. [PMID: 26427431 DOI: 10.1007/978-3-319-17121-0_46] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
One of the earliest events preceding several forms of retinal degeneration is the formation and accumulation of vitamin A dimers in the retinal pigment epithelium (RPE) and underlying Bruch's membrane (BM). Such degenerations include Stargardt disease, Best disease, forms of retinitis pigmentosa, and age-related macular degeneration (AMD). Since their discovery in the 1990's, dimers of vitamin A, have been postulated as chemical triggers driving retinal senescence and degeneration. There is evidence to suggest that the rate at which vitamin A dimerizes and the eye's response to the dimerization products may dictate the retina's lifespan. Here, we present outstanding questions, finding the answers to which may help to elucidate the role of vitamin A dimerization in retinal degeneration.
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Affiliation(s)
- Ilyas Washington
- Department of Ophthalmology, Columbia University Medical Center, 160 Fort Washington Ave, Eye Research, 10032, New York, NY, USA.
| | - Leonide Saad
- Alkeus Pharmaceuticals, Inc., 02210, Boston, MA, USA.
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Moreira EF, Cai H, Tezel TH, Fields MA, Del Priore LV. Reengineering Human Bruch's Membrane Increases Rod Outer Segment Phagocytosis by Human Retinal Pigment Epithelium. Transl Vis Sci Technol 2015; 4:10. [PMID: 26557417 DOI: 10.1167/tvst.4.5.10] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 08/14/2015] [Indexed: 12/21/2022] Open
Abstract
PURPOSE We have shown previously that Bruch's membrane (BM) aging decreases retinal pigment epithelium (RPE) phagocytosis. Herein, we determine the effects of BM reengineering on RPE phagocytosis. METHODS BM explants were dissected from young and old donor eyes. Some old BM explants were reengineered by cleaning with Triton X-100 and/or coating with extracellular matrix (ECM) ligands. ARPE-19 cell-derived ECM (ARPE-ECM) modified ("aged") by sodium nitrite was subjected to similar treatments. ARPE-19 cells were then cultured to confluence onto the different surfaces. Fluorescently-labeled bovine rod outer segments (ROS) were fed to cells with or without αVβ5 integrin antibody. Image acquisition and phagocytosis quantification was performed by fluorescence microscopy and ImageJ analysis. RESULTS Cleaning old donor-derived BM with detergent does not increase the uptake of ROS, but a combination of cleaning and coating with ECM ligands significantly increases RPE phagocytosis (54.9 ± 6.2 vs. 83.5 ± 6.5 arbitrary units; P < 0.05) to levels closer to young donor BM (123.6 ± 9.9 arbitrary units). Similar effects were observed on nitrite-modified ARPE-ECM subjected to the same treatments. Incubation of αVβ5 blocking antibody with ROS significantly decreased RPE phagocytosis. CONCLUSIONS The detrimental effects of aging BM on RPE phagocytosis can be reversed by reengineering the BM surface with detergent cleaning and recoating with ECM ligands. TRANSLATION RELEVANCE These results demonstrate that the therapeutic success of transplanted RPE cells may require, at least in part, reengineering of diseased BM to make it a more suitable environment for attachment, survival and proper functioning of the RPE.
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Affiliation(s)
- Ernesto F Moreira
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Hui Cai
- Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Tongalp H Tezel
- Department of Ophthalmology, Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Mark A Fields
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Lucian V Del Priore
- Department of Ophthalmology Storm Eye Institute, Medical University of South Carolina, Charleston, SC, USA
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Fields MA, Cai H, Bowrey HE, Moreira EF, Beck Gooz M, Kunchithapautham K, Gong J, Vought E, Del Priore LV. Nitrite Modification of Extracellular Matrix Alters CD46 Expression and VEGF Release in Human Retinal Pigment Epithelium. Invest Ophthalmol Vis Sci 2015; 56:4231-8. [PMID: 26161984 PMCID: PMC4703405 DOI: 10.1167/iovs.15-16438] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/17/2015] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Loss of CD46 has recently been implicated in choroidal neovascularization in mice. Herein we investigated the effect of nitrite modification of the extracellular matrix (ECM) as an in vitro model of "aging" and its effect on CD46 expression and vascular endothelial growth factor (VEGF) release in cocultured human retinal pigment epithelium (RPE). METHODS ARPE-19 cells were plated onto RPE-derived ECM conditions (untreated; nitrite modified; nitrite modified followed by washing with Triton X-100; or nitrite modified followed by washing with Triton X-100 and coated with extracellular matrix ligands). Cells were cultured for 7 days and CD46 expression was analyzed by immunohistochemistry and Western blot. Additionally, CD46 short interfering RNA (siRNA) was transfected into ARPE-19 cells, and VEGF levels were determined by ELISA. Finally, in the same ECM conditions, ARPE-19 cells were challenged with normal human serum and VEGF levels determined by ELISA. RESULTS CD46 is expressed on the basolateral surface of ARPE-19 cells on RPE-derived ECM. Nitrite modification of ECM reduced the expression of CD46 on ARPE-19 cells by 0.5-fold (P = 0.003) and increased VEGF release in ARPE-19 cells by 1.7-fold (P < 0.001). CD46 knockdown also increased release of VEGF on the apical and basal sides of ARPE-19 cells in culture by 1.3- (P = 0.012) and 1.2-fold (P = 0.017), respectively. CONCLUSIONS Nitrite modification of the ECM decreased CD46 expression and increased the release of VEGF from ARPE-19 cells. Changes in CD46 expression may lead to changes in VEGF and play a pathologic role in the development of age-related macular degeneration.
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Affiliation(s)
- Mark A. Fields
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Hui Cai
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| | - Hannah E. Bowrey
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
| | - Ernesto F. Moreira
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
| | - Monika Beck Gooz
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Kannan Kunchithapautham
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
| | - Jie Gong
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
| | - Emma Vought
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, United States
| | - Lucian V. Del Priore
- Department of Ophthalmology Medical University of South Carolina, Charleston, South Carolina, United States
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Zhan X, Wang X, Desiderio DM. Mass spectrometry analysis of nitrotyrosine-containing proteins. MASS SPECTROMETRY REVIEWS 2015; 34:423-448. [PMID: 24318073 DOI: 10.1002/mas.21413] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/03/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Oxidative stress plays important roles in a wide range of diseases such as cancer, inflammatory disease, neurodegenerative disorders, etc. Tyrosine nitration in a protein is a chemically stable oxidative modification, and a marker of oxidative injuries. Mass spectrometry (MS) is a key technique to identify nitrotyrosine-containing proteins and nitrotyrosine sites in endogenous and synthetic nitroproteins and nitropeptides. However, in vivo nitrotyrosine-containing proteins occur with extreme low-abundance to severely challenge the use of MS to identify in vivo nitroproteins and nitrotyrosine sites. A preferential enrichment of nitroproteins and/or nitropeptides is necessary before MS analysis. Current enrichment methods include immuno-affinity techniques, chemical derivation of the nitro group plus target isolations, followed with tandem mass spectrometry analysis. This article reviews the MS techniques and pertinent before-MS enrichment techniques for the identification of nitrotyrosine-containing proteins. This article reviews future trends in the field of nitroproteomics, including quantitative nitroproteomics, systems biological networks of nitroproteins, and structural biology study of tyrosine nitration to completely clarify the biological functions of tyrosine nitration.
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Affiliation(s)
- Xianquan Zhan
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
- Hunan Engineering Laboratory for Structural Biology and Drug Design, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
- State Local Joint Engineering Laboratory for Anticancer Drugs, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
- The State Key Laboratory of Medical Genetics, Central South University, 88 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Xiaowei Wang
- Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
- Hunan Engineering Laboratory for Structural Biology and Drug Design, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
- State Local Joint Engineering Laboratory for Anticancer Drugs, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan, 410008, P.R. China
| | - Dominic M Desiderio
- The Charles B. Stout Neuroscience Mass Spectrometry Laboratory, Department of Neurology, College of Medicine, University of Tennessee Health Science Center, 847 Monroe Avenue, Memphis, Tennessee, 38163
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Verrastro I, Pasha S, Jensen KT, Pitt AR, Spickett CM. Mass spectrometry-based methods for identifying oxidized proteins in disease: advances and challenges. Biomolecules 2015; 5:378-411. [PMID: 25874603 PMCID: PMC4496678 DOI: 10.3390/biom5020378] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 03/20/2015] [Accepted: 03/23/2015] [Indexed: 01/02/2023] Open
Abstract
Many inflammatory diseases have an oxidative aetiology, which leads to oxidative damage to biomolecules, including proteins. It is now increasingly recognized that oxidative post-translational modifications (oxPTMs) of proteins affect cell signalling and behaviour, and can contribute to pathology. Moreover, oxidized proteins have potential as biomarkers for inflammatory diseases. Although many assays for generic protein oxidation and breakdown products of protein oxidation are available, only advanced tandem mass spectrometry approaches have the power to localize specific oxPTMs in identified proteins. While much work has been carried out using untargeted or discovery mass spectrometry approaches, identification of oxPTMs in disease has benefitted from the development of sophisticated targeted or semi-targeted scanning routines, combined with chemical labeling and enrichment approaches. Nevertheless, many potential pitfalls exist which can result in incorrect identifications. This review explains the limitations, advantages and challenges of all of these approaches to detecting oxidatively modified proteins, and provides an update on recent literature in which they have been used to detect and quantify protein oxidation in disease.
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Affiliation(s)
- Ivan Verrastro
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
| | - Sabah Pasha
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
| | - Karina Tveen Jensen
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
| | - Andrew R Pitt
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
| | - Corinne M Spickett
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, B4 7ET, UK.
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Kar T, Yildirim Y, Altundağ A, Sonmez M, Kaya A, Colakoglu K, Tekeli H, Cayonu M, Hummel T. The Relationship between Age-Related Macular Degeneration and Olfactory Function. NEURODEGENER DIS 2015; 15:219-24. [DOI: 10.1159/000381216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/12/2015] [Indexed: 11/19/2022] Open
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Yeo WS, Kim YJ, Kabir MH, Kang JW, Ahsan-Ul-Bari M, Kim KP. Mass spectrometric analysis of protein tyrosine nitration in aging and neurodegenerative diseases. MASS SPECTROMETRY REVIEWS 2015; 34:166-183. [PMID: 24889964 DOI: 10.1002/mas.21429] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This review highlights the significance of protein tyrosine nitration (PTN) in signal transduction pathways, the progress achieved in analytical methods, and the implication of nitration in the cellular pathophysiology of aging and age-related neurodegenerative diseases. Although mass spectrometry of nitrated peptides has become a powerful tool for the characterization of nitrated peptides, the low stoichiometry of this modification clearly necessitates the use of affinity chromatography to enrich modified peptides. Analysis of nitropeptides involves identification of endogenous, intact modification as well as chemical conversion of the nitro group to a chemically reactive amine group and further modifications that enable affinity capture and enhance detectability by altering molecular properties. In this review, we focus on the recent progress in chemical derivatization of nitropeptides for enrichment and mass analysis, and for detection and quantification using various analytical tools. PTN participates in physiological processes, such as aging and neurodegenerative diseases. Accumulation of 3-nitrotyrosine has been found to occur during the aging process; this was identified through mass spectrometry. Further, there are several studies implicating the presence of nitrated tyrosine in age-related diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis.
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Affiliation(s)
- Woon-Seok Yeo
- Department of Bioscience and Biotechnology, Bio/Molecular Informatics Center, Konkuk University, Seoul, 143-701, Republic of Korea
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Puntel A, Maeda A, Golczak M, Gao SQ, Yu G, Palczewski K, Lu ZR. Prolonged prevention of retinal degeneration with retinylamine loaded nanoparticles. Biomaterials 2015; 44:103-10. [PMID: 25617130 DOI: 10.1016/j.biomaterials.2014.12.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 12/12/2014] [Accepted: 12/20/2014] [Indexed: 01/07/2023]
Abstract
Retinal degeneration impairs the vision of millions in all age groups worldwide. Increasing evidence suggests that the etiology of many retinal degenerative diseases is associated with impairment in biochemical reactions involved in the visual cycle, a metabolic pathway responsible for regeneration of the visual chromophore (11-cis-retinal). Inefficient clearance of toxic retinoid metabolites, especially all-trans-retinal, is considered responsible for photoreceptor cytotoxicity. Primary amines, including retinylamine, are effective in lowing the concentration of all-trans-retinal within the retina and thus prevent retina degeneration in mouse models of human retinopathies. Here we achieved prolonged prevention of retinal degeneration by controlled delivery of retinylamine to the eye from polylactic acid nanoparticles in Abca4(-/-)Rdh8(-/-) (DKO) mice, an animal model of Stargardt disease/age-related macular degeneration. Subcutaneous administration of the nanoparticles containing retinylamine provided a constant supply of the drug to the eye for about a week and resulted in effective prolonged prevention of light-induced retinal degeneration in DKO mice. Retinylamine nanoparticles hold promise for prolonged prophylactic treatment of human retinal degenerative diseases, including Stargardt disease and age-related macular degeneration.
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Affiliation(s)
- Anthony Puntel
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Akiko Maeda
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44140, USA; Department of Ophthalmology, School of Medicine, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Marcin Golczak
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Song-Qi Gao
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Guanping Yu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44140, USA
| | - Zheng-Rong Lu
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, OH 44140, USA.
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Penn J, Mihai DM, Washington I. Morphological and physiological retinal degeneration induced by intravenous delivery of vitamin A dimers in rabbits. Dis Model Mech 2014; 8:131-8. [PMID: 25504631 PMCID: PMC4314778 DOI: 10.1242/dmm.017194] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The eye uses vitamin A as a cofactor to sense light and, during this process, some vitamin A molecules dimerize, forming vitamin A dimers. A striking chemical signature of retinas undergoing degeneration in major eye diseases such as age-related macular degeneration (AMD) and Stargardt disease is the accumulation of these dimers in the retinal pigment epithelium (RPE) and Bruch's membrane (BM). However, it is not known whether dimers of vitamin A are secondary symptoms or primary insults that drive degeneration. Here, we present a chromatography-free method to prepare gram quantities of the vitamin A dimer, A2E, and show that intravenous administration of A2E to the rabbit results in retinal degeneration. A2E-damaged photoreceptors and RPE cells triggered inflammation, induced remolding of the choroidal vasculature and triggered a decline in the retina's response to light. Data suggest that vitamin A dimers are not bystanders, but can be primary drivers of retinal degeneration. Thus, preventing dimer formation could be a preemptive strategy to address serious forms of blindness.
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Affiliation(s)
- Jackie Penn
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Doina M Mihai
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA
| | - Ilyas Washington
- Columbia University Medical Center, Ophthalmology, New York, NY 10032, USA.
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35
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Mihai DM, Washington I. Vitamin A dimers trigger the protracted death of retinal pigment epithelium cells. Cell Death Dis 2014; 5:e1348. [PMID: 25058422 PMCID: PMC4123103 DOI: 10.1038/cddis.2014.314] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/24/2014] [Accepted: 05/29/2014] [Indexed: 01/05/2023]
Abstract
Cellular events responsible for the initiation of major neurodegenerative disorders of the eye leading to blindness, including age-related macular degeneration, Stargardt and Best diseases, are poorly understood. Accumulation of vitamin A dimers, such as N-retinylidene-N-retinylethanolamine (A2E) in the retinal pigment epithelium (RPE), is one of the earliest measurable events preceding retinal degeneration. However, the extent to which these dimers contribute to tissue degeneration is not clear. To determine if A2E could trigger morphological changes associated with the degenerating RPE and subsequent cell death, we evaluated its toxicity to cultured human RPE cells (ARPE-19). We show that A2E triggered the accumulation of debris followed by a protracted death. A2E was up to ≈ 14-fold more toxic than its precursor, retinaldehyde. Measurements reveal that the concentration of A2E in the aged human eye could exceed the concentration of all other retinoids, opening the possibility of A2E-triggered cell death by several reported mechanisms. Findings suggest that accumulation of vitamin A dimers such as A2E in the human eye might be responsible for the formation of ubiquitous RPE debris, an early indication of retinal degeneration, and that preventing or reducing the accumulation of vitamin A dimers is a prudent strategy to prevent blindness.
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Affiliation(s)
- D M Mihai
- Department of Ophthalmology, Columbia University Medical Center, New York, NY 10032, USA
| | - I Washington
- Department of Ophthalmology, Columbia University Medical Center, New York, NY 10032, USA
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May CA. Chronologic versus biologic aging of the human choroid. ScientificWorldJournal 2013; 2013:378206. [PMID: 24453840 PMCID: PMC3886246 DOI: 10.1155/2013/378206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/03/2013] [Indexed: 12/15/2022] Open
Abstract
Several aspects of chronologic and biologic aging in the human choroid are reviewed from the literature. They often reveal methodological problems for age-dependent changes of the following parameters: choroidal thickness, choroidal pigmentation, choroidal vasculature and blood flow, and choroidal innervation. On reinterpreting some data of studies concerning Bruch's membrane, changes observed at different age points seem more likely to be nonlinear. Concluding from the data presented so far, chronologic aging should not be used as a factor for physiological changes in the human choroid. Longitudinal study designs are necessary to further establish the impact of age. Meanwhile, a more biologic oriented model of aging processes in the choroid should be established, including specified conditions (e.g., light exposure and refractory state). This would help to define more individual strategies for prevention and early stages of a certain defined disease.
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Affiliation(s)
- Christian Albrecht May
- Department of Anatomy, Medical Faculty Carl Gustav Carus, TU Dresden, Fetscherstraβe 74, 01307 Dresden, Germany
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Thao MT, Renfus DJ, Dillon J, Gaillard ER. A2E-mediated photochemical modification to fibronectin and its implications to age-related changes in Bruch's membrane. Photochem Photobiol 2013; 90:329-34. [PMID: 24303925 DOI: 10.1111/php.12200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 10/23/2013] [Indexed: 11/28/2022]
Abstract
Lipofuscin accumulates normally with age and is more pronounced in retinal dystrophies such as age-related macular degeneration. The major bis-retinoid component of lipofuscin is A2E. In addition to cell damage effects by A2E, we have previously demonstrated that blue-light-mediated A2E leads to modifications in the basement membrane protein laminin. Therefore, the purpose of this study was to advance the understanding of A2E photooxidation effects on fibronectin, the major glycoprotein of Bruch's membrane. In this study, A2E was irradiated with blue light in the presence of a fibronectin peptide consisting of amino acids from the integrin binding region. The modification sites were identified via LC/MS. Our research indicated that blue light irradiation caused cleavage throughout the A2E molecule closest to the pyridinium ring, and attached to the fibronectin peptide preferentially at lysine and arginine residues. All of these reactions are similar to the Maillard reaction. Altogether this study suggests that blue-light-irradiated A2E modifies peptides and forms advance glycation endproducts. Furthermore, these results can be used to identify modifications that occur in Bruch's membrane in vivo.
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Affiliation(s)
- Mai T Thao
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL
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Ma L, Dou HL, Huang YM, Lu XR, Xu XR, Qian F, Zou ZY, Pang HL, Dong PC, Xiao X, Wang X, Sun TT, Lin XM. Improvement of retinal function in early age-related macular degeneration after lutein and zeaxanthin supplementation: a randomized, double-masked, placebo-controlled trial. Am J Ophthalmol 2012; 154:625-634.e1. [PMID: 22835510 DOI: 10.1016/j.ajo.2012.04.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE To examine the effects of lutein and zeaxanthin supplementation on retinal function using multifocal electroretinograms (mfERG) in patients with early age-related macular degeneration (AMD). DESIGN Randomized, double-masked, placebo-controlled trial. METHODS One hundred eight subjects with early AMD were randomly assigned to receive 10 mg/d lutein (n = 27), 20 mg/d lutein (n = 27), 10 mg/d lutein plus 10 mg/d zeaxanthin (n = 27), or placebo (n = 27) for 48 weeks. Thirty-six age-matched controls without AMD were also enrolled to compare baseline data with early AMD patients. MfERG responses and macular pigment optical densities (MPODs) were recorded and analyzed at baseline and at 24 and 48 weeks. RESULTS There were significant reductions in N1P1 response densities in ring 1 to ring 3 in early AMD patients compared with the controls (P < .05), whereas neither N1P1 response densities in ring 4 to ring 6 nor P1 peak latencies significantly changed. After 48-week supplementation, the N1P1 response densities showed significant increases in ring 1 for the 20 mg lutein group and for the lutein and zeaxanthin group, and in ring 2 for the 20 mg lutein group. The increases in MPOD related positively to the increases in N1P1 response density in ring 1 and ring 2 for nearly all active treatment groups. N1P1 response densities in ring 3 to ring 6 or P1 peak latencies in all rings did not change significantly in any group. CONCLUSION Early functional abnormalities of the central retina in the early AMD patients could be improved by lutein and zeaxanthin supplementation. These improvements may be potentially attributed to the elevations in MPOD.
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Stanniocalcin-1 rescued photoreceptor degeneration in two rat models of inherited retinal degeneration. Mol Ther 2012; 20:788-97. [PMID: 22294148 DOI: 10.1038/mt.2011.308] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Oxidative stress and photoreceptor apoptosis are prominent features of many forms of retinal degeneration (RD) for which there are currently no effective therapies. We previously observed that mesenchymal stem/stromal cells reduce apoptosis by being activated to secrete stanniocalcin-1 (STC-1), a multifunctional protein that reduces oxidative stress by upregulating mitochondrial uncoupling protein-2 (UCP-2). Therefore, we tested the hypothesis that intravitreal injection of STC-1 can rescue photoreceptors. We first tested STC-1 in the rhodopsin transgenic rat characterized by rapid photoreceptor loss. Intravitreal STC-1 decreased the loss of photoreceptor nuclei and transcripts and resulted in measurable retinal function when none is otherwise present in this rapid degeneration. We then tested STC-1 in the Royal College of Surgeons (RCS) rat characterized by a slower photoreceptor degeneration. Intravitreal STC-1 reduced the number of pyknotic nuclei in photoreceptors, delayed the loss of photoreceptor transcripts, and improved function of rod photoreceptors. Additionally, STC-1 upregulated UCP-2 and decreased levels of two protein adducts generated by reactive oxygen species (ROS). Microarrays from the two models demonstrated that STC-1 upregulated expression of a similar profile of genes for retinal development and function. The results suggested that intravitreal STC-1 is a promising therapy for various forms of RD including retinitis pigmentosa and atrophic age-related macular degeneration (AMD).
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Sripathi SR, He W, Um JY, Moser T, Dehnbostel S, Kindt K, Goldman J, Frost MC, Jahng WJ. Nitric oxide leads to cytoskeletal reorganization in the retinal pigment epithelium under oxidative stress. ACTA ACUST UNITED AC 2012; 3:1167-1178. [PMID: 27974994 DOI: 10.4236/abb.2012.38143] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Light is a risk factor for various eye diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa (RP). We aim to understand how cytoskeletal proteins in the retinal pigment epithetlium (RPE) respond to oxidative stress, including light and how these responses affect apoptotic signaling. Previously, proteomic analysis revealed that the expression levels of vimentin and serine/threonine protein phosphatase 2A (PP2A) are significantly increased when mice are exposed under continuous light for 7 days compared to a condition of 12 hrs light/dark cycling exposure using retina degeneration 1 (rd1) model. When melatonin is administered to animals while they are exposed to continuous light, the levels of vimentin and PP2A return to a normal level. Vimentin is a substrate of PP2A that directly binds to vimentin and dephosphorylates it. The current study shows that upregulation of PP2Ac (catalytic subunit) phosphorylation negatively correlates with vimentin phosphorylation under stress condition. Stabilization of vimentin appears to be achieved by decreased PP2Ac phosphorylation by nitric oxide induction. We tested our hypothesis that site-specific modifications of PP2Ac may drive cytoskeletal reorganization by vimentin dephosphorylation through nitric oxide signaling. We speculate that nitric oxide determines protein nitration under stress conditions. Our results demonstrate that PP2A and vimentin are modulated by nitric oxide as a key element involved in cytoskeletal signaling. The current study suggests that external stress enhances nitric oxide to regulate PP2Ac and vimentin phosphorylation, thereby stabilizing or destabilizing vimentin. Phosphorylation may result in depolymerization of vimentin, leading to nonfilamentous particle formation. We propose that a stabilized vimentin might act as an anti-apoptotic molecule when cells are under oxidative stress.
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Affiliation(s)
- Srinivas R Sripathi
- Department of Biological Sciences, Michigan Technological University, Houghton, USA
| | - Weilue He
- Department of Biological Sciences, Michigan Technological University, Houghton, USA.,Department of Biomedical Engineering, Michigan Technological University, Houghton, USA
| | - Ji-Yeon Um
- Department of Biological Sciences, Michigan Technological University, Houghton, USA
| | - Trevor Moser
- Department of Biological Sciences, Michigan Technological University, Houghton, USA
| | - Stevie Dehnbostel
- Department of Biological Sciences, Michigan Technological University, Houghton, USA
| | - Kimberly Kindt
- Department of Biological Sciences, Michigan Technological University, Houghton, USA
| | - Jeremy Goldman
- Department of Biomedical Engineering, Michigan Technological University, Houghton, USA
| | - Megan C Frost
- Department of Biomedical Engineering, Michigan Technological University, Houghton, USA
| | - Wan Jin Jahng
- Department of Biological Sciences, Michigan Technological University, Houghton, USA.,Retina Proteomics Laboratory, Department of Petroleum Chemistry, American University of Nigeria, Yola, Nigeria
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Mishur RJ, Rea SL. Applications of mass spectrometry to metabolomics and metabonomics: detection of biomarkers of aging and of age-related diseases. MASS SPECTROMETRY REVIEWS 2012; 31:70-95. [PMID: 21538458 DOI: 10.1002/mas.20338] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 03/29/2011] [Accepted: 03/29/2011] [Indexed: 05/20/2023]
Abstract
Every 5 years or so new technologies, or new combinations of old ones, seemingly burst onto the science scene and are then sought after until they reach the point of becoming commonplace. Advances in mass spectrometry instrumentation, coupled with the establishment of standardized chemical fragmentation libraries, increased computing power, novel data-analysis algorithms, new scientific applications, and commercial prospects have made mass spectrometry-based metabolomics the latest sought-after technology. This methodology affords the ability to dynamically catalogue and quantify, in parallel, femtomole quantities of cellular metabolites. The study of aging, and the diseases that accompany it, has accelerated significantly in the last decade. Mutant genes that alter the rate of aging have been found that increase lifespan by up to 10-fold in some model organisms, and substantial progress has been made in understanding fundamental alterations that occur at both the mRNA and protein level in tissues of aging organisms. The application of metabolomics to aging research is still relatively new, but has already added significant insight into the aging process. In this review we summarize these findings. We have targeted our manuscript to two audiences: mass spectrometrists interested in applying their technical knowledge to unanswered questions in the aging field, and gerontologists interested in expanding their knowledge of both mass spectrometry and the most recent advances in aging-related metabolomics.
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Affiliation(s)
- Robert J Mishur
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245, USA.
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Karve TM, Cheema AK. Small changes huge impact: the role of protein posttranslational modifications in cellular homeostasis and disease. JOURNAL OF AMINO ACIDS 2011; 2011:207691. [PMID: 22312457 PMCID: PMC3268018 DOI: 10.4061/2011/207691] [Citation(s) in RCA: 231] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/18/2011] [Indexed: 01/08/2023]
Abstract
Posttranslational modifications (PTMs) modulate protein function in most eukaryotes and have a ubiquitous role in diverse range of cellular functions. Identification, characterization, and mapping of these modifications to specific amino acid residues on proteins are critical towards understanding their functional significance in a biological context. The interpretation of proteome data obtained from the high-throughput methods cannot be deciphered unambiguously without a priori knowledge of protein modifications. An in-depth understanding of protein PTMs is important not only for gaining a perception of a wide array of cellular functions but also towards developing drug therapies for many life-threatening diseases like cancer and neurodegenerative disorders. Many of the protein modifications like ubiquitination play a decisive role in various drug response(s) and eventually in disease prognosis. Thus, many commonly observed PTMs are routinely tracked as disease markers while many others are used as molecular targets for developing target-specific therapies. In this paper, we summarize some of the major, well-studied protein alterations and highlight their importance in various chronic diseases and normal development. In addition, other promising minor modifications such as SUMOylation, observed to impact cellular dynamics as well as disease pathology, are mentioned briefly.
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Affiliation(s)
- Tejaswita M Karve
- Department of Biochemistry, Cellular & Molecular Biology, Lombardi Comprehensive Cancer Center, Georgetown University School of Medicine, 3900 Reservoir Road, NW, Washington DC 20057, USA
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Ardeljan D, Tuo J, Chan CC. Carboxyethylpyrrole plasma biomarkers in age-related macular degeneration. DRUG FUTURE 2011; 36:712-718. [PMID: 23847393 DOI: 10.1358/dof.2011.036.09.1678338] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Age-related macular degeneration causes irreversible central blindness in people over the age of 50 and is increasing in prevalence among elderly populations. There are currently limited treatment options available for the exudative form of the disease and no formal treatments for the geographic atrophy form aside from lifestyle change and incorporation of antioxidant supplements in the diet. As such, it is important to be able to assess high-risk AMD patients as early as possible in order to prescribe preventative measures. Carboxyethylpyrrole (CEP) is a promising plasma biomarker suited to this purpose. Both CEP immunoreactivity levels as well as anti-CEP autoantibody titers are significantly elevated in AMD patients and thus provide the potential to assess AMD susceptibility with approximately 80% accuracy when evaluated alongside genomic AMD markers. Moreover, strong evidence implicates CEP as functionally related to AMD pathogenesis, a role which must be explored further. This avenue of research will foster improved understanding of the disease itself and perhaps reveal better therapeutic targets and options. Further research into the role of CEP in AMD pathogenesis and the application of CEP as an AMD biomarker is merited.
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Affiliation(s)
- Daniel Ardeljan
- Immunopathology Section, Laboratory of Immunology National Eye Institute, National Institutes of Health
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Wielgus AR, Collier RJ, Martin E, Lih FB, Tomer KB, Chignell CF, Roberts JE. Blue light induced A2E oxidation in rat eyes – experimental animal model of dry AMD. Photochem Photobiol Sci 2010; 9:1505-12. [DOI: 10.1039/c0pp00133c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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