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Smith AS, Subramanian J, Doderer J, Moskovitz J. Methionine oxidation of clusterin in Alzheimer's disease and its effect on clusterin's binding to beta-amyloid. Neurosci Lett 2024; 836:137874. [PMID: 38857696 DOI: 10.1016/j.neulet.2024.137874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/20/2024] [Accepted: 06/07/2024] [Indexed: 06/12/2024]
Abstract
Clusterin is a secreted glycoprotein that participates in multiple physiological processes through its chaperon function. In Alzheimer's disease, the brain functions under an increased oxidative stress condition that causes an elevation of protein oxidation, resulting in enhanced pathology. Accordingly, it is important to determine the type of human brain cells that are mostly prone to methionine oxidation in Alzheimer's disease and specifically monitoring the methionine-oxidation levels of clusterin in human and mice brains and its effect on clusterin's function. We analyzed the level of methionine sulfoxide (MetO)-clusterin in these brains, using a combination of immunoprecipitation and Western-blott analyses. Also, we determine the effect of methionine oxidation on clusterin ability to bind beta-amyloid, in vitro, using calorimetric assay. Our results show that human neurons and astrocytes of Alzheimer's disease brains are mostly affected by methionine oxidation. Moreover, MetO-clusterin levels are elevated in postmortem Alzheimer's disease human and mouse brains in comparison to controls. Finally, oxidation of methionine residues of purified clusterin reduced its binding efficiency to beta-amyloid. In conclusion, we suggest that methionine oxidation of brain-clusterin is enhanced in Alzheimer's disease and that this oxidation compromises its chaperon function, leading to exacerbation of beta-amyloid's toxicity in Alzheimer's disease.
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Affiliation(s)
- Adam S Smith
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Julia Doderer
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Jackob Moskovitz
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA.
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2
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Massri M, Toonen EJ, Sarg B, Kremser L, Grasse M, Fleischer V, Torres-Quesada O, Hengst L, Skjoedt MO, Bayarri-Olmos R, Rosbjerg A, Garred P, Orth-Höller D, Prohászka Z, Würzner R. Complement C7 and clusterin form a complex in circulation. Front Immunol 2024; 15:1330095. [PMID: 38333209 PMCID: PMC10850381 DOI: 10.3389/fimmu.2024.1330095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/04/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction The complement system is part of innate immunity and is comprised of an intricate network of proteins that are vital for host defense and host homeostasis. A distinct mechanism by which complement defends against invading pathogens is through the membrane attack complex (MAC), a lytic structure that forms on target surfaces. The MAC is made up of several complement components, and one indispensable component of the MAC is C7. The role of C7 in MAC assembly is well documented, however, inherent characteristics of C7 are yet to be investigated. Methods To shed light on the molecular characteristics of C7, we examined the properties of serum-purified C7 acquired using polyclonal and novel monoclonal antibodies. The properties of serum‑purified C7 were investigated through a series of proteolytic analyses, encompassing Western blot and mass spectrometry. The nature of C7 protein-protein interactions were further examined by a novel enzyme-linked immunosorbent assay (ELISA), as well as size‑exclusion chromatography. Results Protein analyses showcased an association between C7 and clusterin, an inhibitory complement regulator. The distinct association between C7 and clusterin was also demonstrated in serum-purified clusterin. Further assessment revealed that a complex between C7 and clusterin (C7-CLU) was detected. The C7-CLU complex was also identified in healthy serum and plasma donors, highlighting the presence of the complex in circulation. Discussion Clusterin is known to dissociate the MAC structure by binding to polymerized C9, nevertheless, here we show clusterin binding to the native form of a terminal complement protein in vivo. The presented data reveal that C7 exhibits characteristics beyond that of MAC assembly, instigating further investigation of the effector role that the C7-CLU complex plays in the complement cascade.
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Affiliation(s)
- Mariam Massri
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Bettina Sarg
- Institute of Medical Biochemsitry, Protein Core Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Leopold Kremser
- Institute of Medical Biochemsitry, Protein Core Facility, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Marco Grasse
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Verena Fleischer
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Omar Torres-Quesada
- Institute of Medical Biochemistry, Medical University of Innsbruck, Biocenter, Innsbruck, Austria
- Tyrolean Cancer Research Institute, Innsbruck, Austria
| | - Ludger Hengst
- Institute of Medical Biochemistry, Medical University of Innsbruck, Biocenter, Innsbruck, Austria
| | - Mikkel-Ole Skjoedt
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Institute of Immunology & Microbiology , University of Copenhagen, Copenhagen, Denmark
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Anne Rosbjerg
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Dorothea Orth-Höller
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
- MB-LAB Clinical Microbiology Laboratory, Innsbruck, Austria
| | - Zoltán Prohászka
- Department of Internal Medicine and Hematology, Semmelweis University, Budapest, Hungary
- Research Group for Immunology and Hematology, Semmelweis University-Eötvös Loránd Research Network (Office for Supported Research Groups), Budapest, Hungary
| | - Reinhard Würzner
- Institute of Hygiene & Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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3
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Kędzierski J, Allard JA, Odermatt A, Smieško M. Assessment of the inhibitory potential of anabolic steroids towards human AKR1D1 by computational methods and in vitro evaluation. Toxicol Lett 2023; 384:1-13. [PMID: 37451653 DOI: 10.1016/j.toxlet.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/21/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Exposure to xenobiotics can adversely affect biochemical reactions, including hepatic bile acid synthesis. Bile acids are essential for dissolving lipophilic compounds in the hydrophilic environment of the gastrointestinal tract. The critical micellar concentration of bile acids depends on the Δ4-reduction stereochemistry, with the 3-oxo-5β-steroid-Δ4-dehydrogenase (AKR1D1) introducing the cis ring A/B conformation. Loss-of-function mutations in AKR1D1 cause hepatic cholestasis, which, if left untreated can progress into steatosis and liver cirrhosis. Furthermore, AKR1D1 is involved in clearing steroids with an A-ring Δ4-double bond. Here, we tested whether anabolic-androgenic steroids (AAS), often taken off-label at high doses, might inhibit AKR1D1, thereby potentially causing hepatotoxicity. A computational molecular model was established and used for virtual screening of the DrugBank database consisting of 2740 molecules, yielding mainly steroidal hits. Fourteen AAS were selected for in vitro evaluation, as such compounds can reach high hepatic concentrations in an abuse situation. Nandrolone, clostebol, methasterone, drostanolone, and methenolone inhibited to various extent the AKR1D1-mediated reduction of testosterone. Molecular modeling suggests that 9 out of 14 investigated AAS are competitive inhibitors. Moreover quantum mechanical calculations show that nadrolone and clostebol are substrates of AKR1D1 with different activation energy barriers for the hydrogen transfer from cofactor to the C5 position affecting their turnover. In this multidisciplinary approach, we established a molecular model of AKR1D1, identified several AAS as inhibitors, and described their binding mode. This approach may be applied to study other classes of inhibitors including non-steroidal compounds.
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Affiliation(s)
- Jacek Kędzierski
- Computational Pharmacy, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland; Swiss Centre for Human Applied Toxicology, University of Basel, Missionsstrasse 64, Basel 4055, Switzerland
| | - Julien A Allard
- Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland; Swiss Centre for Human Applied Toxicology, University of Basel, Missionsstrasse 64, Basel 4055, Switzerland
| | - Alex Odermatt
- Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland; Swiss Centre for Human Applied Toxicology, University of Basel, Missionsstrasse 64, Basel 4055, Switzerland
| | - Martin Smieško
- Computational Pharmacy, Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, Basel 4056, Switzerland; Swiss Centre for Human Applied Toxicology, University of Basel, Missionsstrasse 64, Basel 4055, Switzerland.
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4
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Bell R, Vendruscolo M, Kumita JR. Probing the effects of N-terminal acetylation on α-synuclein structure, aggregation and cytotoxicity. Methods Enzymol 2023; 686:45-65. [PMID: 37532408 DOI: 10.1016/bs.mie.2022.09.003] [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] [Indexed: 03/12/2023]
Abstract
Parkinson's disease is associated with the aberrant aggregation of α-synuclein within brain cells. Although the causes of this process are still unclear, post-translational modifications of α-synuclein are likely to play a modulatory role. Since α-synuclein is constitutively N-terminally acetylated, we previously investigated how this protein modification affects the aggregation behavior of the protein using a variety of methods in vitro and in cell systems. This chapter describes the production of N-terminally acetylated (NTA) α-synuclein, the preparation of different seeds of NTA α-synuclein for aggregation assays and the experimental methods for the kinetic analysis of the aggregation process of NTA α-synuclein. We also detail our protocol to evaluate the effects of preformed protofibrils of NTA α-synuclein in cell-based assays. These methods can be applied to study other post-translational modifications of α-synuclein, or adapted for the study of N-acetylation of other aggregation-prone proteins.
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Affiliation(s)
- Rosie Bell
- Yusef Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Michele Vendruscolo
- Yusef Hamied Department of Chemistry, University of Cambridge, Cambridge, United Kingdom
| | - Janet R Kumita
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
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5
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Das L, Shekhar S, Chandrani P, Varma AK. In silico structural analysis of secretory clusterin to assess pathogenicity of mutations identified in the evolutionarily conserved regions. J Biomol Struct Dyn 2023; 41:469-478. [PMID: 34821197 DOI: 10.1080/07391102.2021.2007791] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Clusterin (CLU) is a secreted glycoprotein, heterodimeric in nature, and is expressed in a wide variety of tissues and body fluids such as serum and plasma. CLU has also been known to be a promising biomarker for cell death, malignancy, cancer progression, and resistance development. However, the lack of a CLU crystal structure obstructs understanding the possible role of reported mutations on the structure, and the subsequent effects on downstream signaling pathways and cancer progression. Considering the importance of crystal structure, a model structure of the pre-secretory isoform of CLU was built to predict the effect of mutations at the molecular level. Ab initio model was built using RaptorX, and loop refinement and energy minimization were carried out with ModLoop, ModRefiner, and GalaxyWeb servers. The cancer associated mutational spectra of CLU was retrieved from the cBioPortal server and 117 unique missense mutations were identified. Evolutionarily conserved regions and pathogenicity of mutations identified in CLU were analyzed using ConSurf and Rhapsody, respectively. Furthermore, sequence and structure-based mutational analysis were carried out with iSTABLE, DynaMut and PremPS servers. Molecular dynamics simulations were carried out with GROMACS for 50 ns to determine the stability of the wild type and mutant protein structures. A dynamically stable model structure of pre-secretory CLU (psCLU) which has high concurrence with the sequence based secondary structure predictions has been explored. Changes in the intra-atomic interactions and folding pattern between wild type and mutant structures were observed. To our conclusion, eleven mutations with the highest structural and functional significance have been predicted to have pathogenic and deleterious effects.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Lipi Das
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India.,Homi Bhabha National Institute, Training School Complex, Mumbai, India
| | - Shashank Shekhar
- Supercomputing Facility for Bioinformatics & Computational Biology, Indian Institute of Technology, New Delhi, India
| | - Pratik Chandrani
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India.,Homi Bhabha National Institute, Training School Complex, Mumbai, India.,Medical Oncology Molecular Lab, Tata Memorial Hospital, Mumbai, India
| | - Ashok K Varma
- Advanced Centre for Treatment, Research and Education in Cancer, Navi Mumbai, India.,Homi Bhabha National Institute, Training School Complex, Mumbai, India
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Chintala SK, Pan J, Satapathy S, Condruti R, Hao Z, Liu PW, O’Conner CF, Barr JT, Wilson MR, Jeong S, Fini ME. Recombinant Human Clusterin Seals Damage to the Ocular Surface Barrier in a Mouse Model of Ophthalmic Preservative-Induced Epitheliopathy. Int J Mol Sci 2023; 24:ijms24020981. [PMID: 36674497 PMCID: PMC9861099 DOI: 10.3390/ijms24020981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/23/2022] [Accepted: 12/31/2022] [Indexed: 01/07/2023] Open
Abstract
There is a significant unmet need for therapeutics to treat ocular surface barrier damage, also called epitheliopathy, due to dry eye and related diseases. We recently reported that the natural tear glycoprotein CLU (clusterin), a molecular chaperone and matrix metalloproteinase inhibitor, seals and heals epitheliopathy in mice subjected to desiccating stress in a model of aqueous-deficient/evaporative dry eye. Here we investigated CLU sealing using a second model with features of ophthalmic preservative-induced dry eye. The ocular surface was stressed by topical application of the ophthalmic preservative benzalkonium chloride (BAC). Then eyes were treated with CLU and sealing was evaluated immediately by quantification of clinical dye uptake. A commercial recombinant form of human CLU (rhCLU), as well as an rhCLU form produced in our laboratory, designed to be compatible with U.S. Food and Drug Administration guidelines on current Good Manufacturing Practices (cGMP), were as effective as natural plasma-derived human CLU (pCLU) in sealing the damaged ocular surface barrier. In contrast, two other proteins found in tears: TIMP1 and LCN1 (tear lipocalin), exhibited no sealing activity. The efficacy and selectivity of rhCLU for sealing of the damaged ocular surface epithelial barrier suggests that it could be of therapeutic value in treating BAC-induced epitheliopathy and related diseases.
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Affiliation(s)
- Shravan K. Chintala
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Jinhong Pan
- New England Eye Center, Tufts Medical Center, Department of Ophthalmology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Sandeep Satapathy
- School of Chemistry and Molecular Bioscience, Molecular Horizons Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Rebecca Condruti
- Training Program in Cell, Molecular and Developmental Biology, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Zixuan Hao
- Training Program in Pharmacology and Drug Development, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Pei-wen Liu
- Training Program in Pharmacology and Drug Development, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Christian F. O’Conner
- Doctor of Medicine Training Program, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Joseph T. Barr
- The Ohio State University College of Optometry, Columbus, OH 43210, USA
| | - Mark R. Wilson
- School of Chemistry and Molecular Bioscience, Molecular Horizons Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Shinwu Jeong
- USC Roski Eye Institute, Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - M. Elizabeth Fini
- New England Eye Center, Tufts Medical Center, Department of Ophthalmology, Tufts University School of Medicine, Boston, MA 02111, USA
- Correspondence:
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7
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Wilson MR, Satapathy S, Jeong S, Fini ME. Clusterin, other extracellular chaperones, and eye disease. Prog Retin Eye Res 2021; 89:101032. [PMID: 34896599 DOI: 10.1016/j.preteyeres.2021.101032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 11/30/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022]
Abstract
Proteostasis refers to all the processes that maintain the correct expression level, location, folding and turnover of proteins, essential to organismal survival. Both inside cells and in body fluids, molecular chaperones play key roles in maintaining proteostasis. In this article, we focus on clusterin, the first-recognized extracellular mammalian chaperone, and its role in diseases of the eye. Clusterin binds to and inhibits the aggregation of proteins that are misfolded due to mutations or stresses, clears these aggregating proteins from extracellular spaces, and facilitates their degradation. Clusterin exhibits three main homeostatic activities: proteostasis, cytoprotection, and anti-inflammation. The so-called "protein misfolding diseases" are caused by aggregation of misfolded proteins that accumulate pathologically as deposits in tissues; we discuss several such diseases that occur in the eye. Clusterin is typically found in these deposits, which is interpreted to mean that its capacity as a molecular chaperone to maintain proteostasis is overwhelmed in the disease state. Nevertheless, the role of clusterin in diseases involving such deposits needs to be better defined before therapeutic approaches can be entertained. A more straightforward case can be made for therapeutic use of clusterin based on its proteostatic role as a proteinase inhibitor, as well as its cytoprotective and anti-inflammatory properties. It is likely that clusterin works together in this way with other extracellular chaperones to protect the eye from disease, and we discuss several examples. We end this article by predicting future steps that may lead to development of clusterin as a biological drug.
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Affiliation(s)
- Mark R Wilson
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Sandeep Satapathy
- Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong; Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, New South Wales, 2522, Australia.
| | - Shinwu Jeong
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 1333 San Pablo Street., Los Angeles, CA, 90033, USA.
| | - M Elizabeth Fini
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine; Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences, Tufts University, 800 Washington St, Boston, MA, 02111, USA.
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8
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Priest L, Peters JS, Kukura P. Scattering-based Light Microscopy: From Metal Nanoparticles to Single Proteins. Chem Rev 2021; 121:11937-11970. [PMID: 34587448 PMCID: PMC8517954 DOI: 10.1021/acs.chemrev.1c00271] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Indexed: 02/02/2023]
Abstract
Our ability to detect, image, and quantify nanoscopic objects and molecules with visible light has undergone dramatic improvements over the past few decades. While fluorescence has historically been the go-to contrast mechanism for ultrasensitive light microscopy due to its superior background suppression and specificity, recent developments based on light scattering have reached single-molecule sensitivity. They also have the advantages of universal applicability and the ability to obtain information about the species of interest beyond its presence and location. Many of the recent advances are driven by novel approaches to illumination, detection, and background suppression, all aimed at isolating and maximizing the signal of interest. Here, we review these developments grouped according to the basic principles used, namely darkfield imaging, interferometric detection, and surface plasmon resonance microscopy.
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Affiliation(s)
| | | | - Philipp Kukura
- Physical and Theoretical
Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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9
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Xu L, Tian S, Peng X, Hua Y, Yang W, Chen L, Liu S, Wu W, Zhao J, He J, Wu L, Yang J, Zheng Y. Clusterin inhibits Aβ 42 aggregation through a "strawberry model" as detected by FRET-FCS. J Neurochem 2021; 158:444-454. [PMID: 33694231 DOI: 10.1111/jnc.15344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 02/19/2021] [Accepted: 03/07/2021] [Indexed: 11/28/2022]
Abstract
Extracellular plaque deposits of β-amyloid peptide (Aβ) are one of the main pathological features of Alzheimer's disease (AD). The aggregation of Aβ42 species, especially Aβ42 oligomers, is still an active research field in AD pathogenesis. Secretory clusterin protein (sCLU), an extracellular chaperone, plays an important role in AD pathogenesis. Although sCLU interacts directly with Aβ42 in vitro and in vivo, the mechanism is not clear. In this paper, His-tagged sCLU (sCLU-His) was cloned, expressed and purified, and we applied florescence resonance energy transfer-fluorescence correlation spectroscopy (FRET-FCS) to investigate the direct interaction of sCLU-His and Aβ42 at the single-molecule fluorescence level in vitro. Here, we chose four different fluorescently labeled Aβ42 oligomers to form two different groups of aggregation models, easy or difficult to aggregate. The results showed that sCLU-His could form complexes with both aggregation models, and sCLU-His inhibited the aggregation of Aβ42/RB ~ Aβ42/Atto647 (easy to aggregate model). The complexes were produced as the Aβ42/Label adhered to the sCLU-His, which is similar to a "strawberry model," as strawberry seeds are dotted on the outer surface of strawberries. This work provided additional insight into the interaction mechanism of sCLU and Aβ42 .
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Affiliation(s)
- Lingwan Xu
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Shijun Tian
- Hebei Agriculture University, Baoding, China
| | - Xianglei Peng
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Ying Hua
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Wenxuan Yang
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Longwei Chen
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Shilei Liu
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Wenzheng Wu
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Jiang Zhao
- Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Jinsheng He
- School of Sciences, Beijing Jiaotong University, Beijing, China
| | - Liqing Wu
- National Institute of Metrology, Beijing, China
| | - Jingfa Yang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Yanpeng Zheng
- School of Sciences, Beijing Jiaotong University, Beijing, China
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10
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Fini ME, Jeong S, Wilson MR. Therapeutic Potential of the Molecular Chaperone and Matrix Metalloproteinase Inhibitor Clusterin for Dry Eye. Int J Mol Sci 2020; 22:E116. [PMID: 33374364 PMCID: PMC7794831 DOI: 10.3390/ijms22010116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/29/2022] Open
Abstract
Evidence is presented herein supporting the potential of the natural homeostatic glycoprotein CLU (clusterin) as a novel therapeutic for the treatment of dry eye. This idea began with the demonstration that matrix metalloproteinase MMP9 is required for damage to the ocular surface in mouse dry eye. Damage was characterized by degradation of OCLN (occludin), a known substrate of MMP9 and a key component of the paracellular barrier. Following up on this finding, a yeast two-hybrid screen was conducted using MMP9 as the bait to identify other proteins involved. CLU emerged as a strong interacting protein that inhibits the enzymatic activity of MMP9. Previously characterized as a molecular chaperone, CLU is expressed prominently by epithelia at fluid-tissue interfaces and secreted into bodily fluids, where it protects cells and tissues against damaging stress. It was demonstrated that CLU also protects the ocular surface in mouse dry eye when applied topically to replace the natural protein depleted from the dysfunctional tears. CLU is similarly depleted from tears in human dry eye. The most novel and interesting finding was that CLU binds selectively to the damaged ocular surface. In this position, CLU protects against epithelial cell death and barrier proteolysis, and dampens the autoimmune response, while the apical epithelial cell layer is renewed. When present at high enough concentration, CLU also blocks staining by vital dyes used clinically to diagnose dry eye. None of the current therapeutics have this combination of properties to "protect, seal, and heal". Future work will be directed towards human clinical trials to investigate the therapeutic promise of CLU.
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Affiliation(s)
- M. Elizabeth Fini
- New England Eye Center, Tufts Medical Center and Department of Ophthalmology, Tufts University School of Medicine, Program in Pharmacology & Drug Development, Graduate School of Biomedical Sciences Tufts University, Boston, MA 02111, USA
| | - Shinwu Jeong
- Department of Ophthalmology, USC Roski Eye Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90089, USA;
| | - Mark R. Wilson
- The Illawarra Health and Medical Research Institute, Molecular Horizons and the School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia;
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11
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Balcar VJ, Zeman T, Janout V, Janoutová J, Lochman J, Šerý O. Single Nucleotide Polymorphism rs11136000 of CLU Gene (Clusterin, ApoJ) and the Risk of Late-Onset Alzheimer's Disease in a Central European Population. Neurochem Res 2020; 46:411-422. [PMID: 33206315 DOI: 10.1007/s11064-020-03176-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 11/28/2022]
Abstract
Clusterin (CLU; also known as apolipoprotein J, ApoJ) is a protein of inconstant structure known to be involved in diverse processes inside and outside of brain cells. CLU can act as a protein chaperon or protein solubilizer, lipid transporter as well as redox sensor and be anti- or proapoptotic, depending on context. Primary structure of CLU is encoded by CLU gene which contains single nucleotide polymorphisms (SNP's) associated with the risk of late-onset Alzheimer's disease (LOAD). Studying a sample of Czech population and using the case-control association approach we identified C allele of the SNP rs11136000 as conferring a reduced risk of LOAD, more so in females than in males. Additionally, data from two smaller subsets of the population sample suggested a possible association of rs11136000 with diabetes mellitus. In a parallel study, we found no association between rs11136000 and mild cognitive impairment (MCI). Our findings on rs11136000 and LOAD contradict those of some previous studies done elsewhere. We discuss the multiple roles of CLU in a broad range of molecular mechanisms that may contribute to the variability of genetic studies of CLU in various ethnic groups. The above discordance notwithstanding, our conclusions support the association of rs1113600 with the risk of LOAD.
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Affiliation(s)
- Vladimir J Balcar
- Bosch Institute and Discipline of Anatomy and Histology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia. .,Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.
| | - Tomáš Zeman
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Vladimír Janout
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic.,Present address: Faculty of Health Sciences, Palacký University Olomouc, Olomouc, Czech Republic
| | - Jana Janoutová
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic.,Present address: Faculty of Health Sciences, Palacký University Olomouc, Olomouc, Czech Republic
| | - Jan Lochman
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Omar Šerý
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
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