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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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2
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Berdowska I, Matusiewicz M, Krzystek-Korpacka M. HDL Accessory Proteins in Parkinson’s Disease—Focusing on Clusterin (Apolipoprotein J) in Regard to Its Involvement in Pathology and Diagnostics—A Review. Antioxidants (Basel) 2022; 11:antiox11030524. [PMID: 35326174 PMCID: PMC8944556 DOI: 10.3390/antiox11030524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 02/04/2023] Open
Abstract
Parkinson’s disease (PD)—a neurodegenerative disorder (NDD) characterized by progressive destruction of dopaminergic neurons within the substantia nigra of the brain—is associated with the formation of Lewy bodies containing mainly α-synuclein. HDL-related proteins such as paraoxonase 1 and apolipoproteins A1, E, D, and J are implicated in NDDs, including PD. Apolipoprotein J (ApoJ, clusterin) is a ubiquitous, multifunctional protein; besides its engagement in lipid transport, it modulates a variety of other processes such as immune system functionality and cellular death signaling. Furthermore, being an extracellular chaperone, ApoJ interacts with proteins associated with NDD pathogenesis (amyloid β, tau, and α-synuclein), thus modulating their properties. In this review, the association of clusterin with PD is delineated, with respect to its putative involvement in the pathological mechanism and its application in PD prognosis/diagnosis.
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Affiliation(s)
- Izabela Berdowska
- Correspondence: (I.B.); (M.M.); Tel.: +48-71-784-13-92 (I.B.); +48-71-784-13-70 (M.M.)
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3
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Thum C, Roy NC, Everett DW, McNabb WC. Variation in milk fat globule size and composition: A source of bioactives for human health. Crit Rev Food Sci Nutr 2021; 63:87-113. [PMID: 34190660 DOI: 10.1080/10408398.2021.1944049] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Milk fat globules (MFGs) are secreted from the mammalian gland and are composed of a triacylglycerol core surrounded by a triple membrane structure, the milk fat globule membrane (MFGM). The MFGM contains complex lipids and proteins reported to have nutritional, immunological, neurological and digestive functions. Human and ruminant milk are shown to share a similar MFG structure but with different size, profile and abundance of protein and polar lipids. This review summarizes the reported data on human, bovine, caprine and ovine MFG composition and concentration of bioactive components in different MFG-size fractions. A comprehensive understanding of compositional variations between milk from different species and MFG size fractions may help promote various milk sources as targeted supplements to improve human development and health. MFG size and MFGM composition are species-specific and affected by lactation, diet and breed (or maternal origin). Purification and enrichment methods for some bioactive proteins and lipids present in the MFGM have yet to be established or are not scaled sufficiently to be used to supplement human diets. To overcome this problem, MFG size selection through fractionation or herd selection may provide a convenient way to pre-enrich the MFG fraction with specific protein and lipid components to fulfill human dietary and health requirements.
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Affiliation(s)
- Caroline Thum
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand.,Riddet Institute, Palmerston North, New Zealand
| | - Nicole C Roy
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand.,Riddet Institute, Palmerston North, New Zealand.,High-Value Nutrition National Science Challenge, The University of Auckland, Auckland, New Zealand.,Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - David W Everett
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand.,Riddet Institute, Palmerston North, New Zealand
| | - Warren C McNabb
- Riddet Institute, Palmerston North, New Zealand.,High-Value Nutrition National Science Challenge, The University of Auckland, Auckland, New Zealand
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4
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Chaplot K, Jarvela TS, Lindberg I. Secreted Chaperones in Neurodegeneration. Front Aging Neurosci 2020; 12:268. [PMID: 33192447 PMCID: PMC7481362 DOI: 10.3389/fnagi.2020.00268] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/03/2020] [Indexed: 12/11/2022] Open
Abstract
Protein homeostasis, or proteostasis, is a combination of cellular processes that govern protein quality control, namely, protein translation, folding, processing, and degradation. Disruptions in these processes can lead to protein misfolding and aggregation. Proteostatic disruption can lead to cellular changes such as endoplasmic reticulum or oxidative stress; organelle dysfunction; and, if continued, to cell death. A majority of neurodegenerative diseases involve the pathologic aggregation of proteins that subverts normal neuronal function. While prior reviews of neuronal proteostasis in neurodegenerative processes have focused on cytoplasmic chaperones, there is increasing evidence that chaperones secreted both by neurons and other brain cells in the extracellular - including transsynaptic - space play important roles in neuronal proteostasis. In this review, we will introduce various secreted chaperones involved in neurodegeneration. We begin with clusterin and discuss its identification in various protein aggregates, and the use of increased cerebrospinal fluid (CSF) clusterin as a potential biomarker and as a potential therapeutic. Our next secreted chaperone is progranulin; polymorphisms in this gene represent a known genetic risk factor for frontotemporal lobar degeneration, and progranulin overexpression has been found to be effective in reducing Alzheimer's- and Parkinson's-like neurodegenerative phenotypes in mouse models. We move on to BRICHOS domain-containing proteins, a family of proteins containing highly potent anti-amyloidogenic activity; we summarize studies describing the biochemical mechanisms by which recombinant BRICHOS protein might serve as a therapeutic agent. The next section of the review is devoted to the secreted chaperones 7B2 and proSAAS, small neuronal proteins which are packaged together with neuropeptides and released during synaptic activity. Since proteins can be secreted by both classical secretory and non-classical mechanisms, we also review the small heat shock proteins (sHsps) that can be secreted from the cytoplasm to the extracellular environment and provide evidence for their involvement in extracellular proteostasis and neuroprotection. Our goal in this review focusing on extracellular chaperones in neurodegenerative disease is to summarize the most recent literature relating to neurodegeneration for each secreted chaperone; to identify any common mechanisms; and to point out areas of similarity as well as differences between the secreted chaperones identified to date.
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Affiliation(s)
| | | | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, University of Maryland, Baltimore, Baltimore, MD, United States
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5
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Whiten DR, Cox D, Horrocks MH, Taylor CG, De S, Flagmeier P, Tosatto L, Kumita JR, Ecroyd H, Dobson CM, Klenerman D, Wilson MR. Single-Molecule Characterization of the Interactions between Extracellular Chaperones and Toxic α-Synuclein Oligomers. Cell Rep 2019; 23:3492-3500. [PMID: 29924993 PMCID: PMC6024880 DOI: 10.1016/j.celrep.2018.05.074] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/26/2018] [Accepted: 05/22/2018] [Indexed: 12/28/2022] Open
Abstract
The aberrant aggregation of α-synuclein is associated with several human diseases, collectively termed the α-synucleinopathies, which includes Parkinson’s disease. The progression of these diseases is, in part, mediated by extracellular α-synuclein oligomers that may exert effects through several mechanisms, including prion-like transfer, direct cytotoxicity, and pro-inflammatory actions. In this study, we show that two abundant extracellular chaperones, clusterin and α2-macroglobulin, directly bind to exposed hydrophobic regions on the surface of α-synuclein oligomers. Using single-molecule fluorescence techniques, we found that clusterin, unlike α2-macroglobulin, exhibits differential binding to α-synuclein oligomers that may be related to structural differences between two previously described forms of αS oligomers. The binding of both chaperones reduces the ability of the oligomers to permeabilize lipid membranes and prevents an oligomer-induced increase in ROS production in cultured neuronal cells. Taken together, these data suggest a neuroprotective role for extracellular chaperones in suppressing the toxicity associated with α-synuclein oligomers. Two extracellular chaperones directly bind to α-synuclein oligomers The binding is mediated by hydrophobicity on the oligomer surface Bound chaperones significantly attenuate the toxicity of α-synuclein oligomers
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Affiliation(s)
- Daniel R Whiten
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK; Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong 2522, NSW, Australia
| | - Dezerae Cox
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong 2522, NSW, Australia
| | - Mathew H Horrocks
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK; Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong 2522, NSW, Australia
| | - Christopher G Taylor
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Suman De
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Patrick Flagmeier
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Laura Tosatto
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Janet R Kumita
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Heath Ecroyd
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong 2522, NSW, Australia
| | - Christopher M Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK; UK Dementia Research Institute, University of Cambridge, Cambridge CB2 0XY, UK.
| | - Mark R Wilson
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong 2522, NSW, Australia.
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6
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Wiggs JL, Kang JH, Fan B, Levkovitch-Verbin H, Pasquale LR. A Role for Clusterin in Exfoliation Syndrome and Exfoliation Glaucoma? J Glaucoma 2018; 27 Suppl 1:S61-S66. [PMID: 29965900 PMCID: PMC8035929 DOI: 10.1097/ijg.0000000000000916] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The multifunctional protein clusterin (CLU) is a secreted glycoprotein ubiquitously expressed throughout the body, including in the eye. Its primary function is to act as an extracellular molecular chaperone, preventing the precipitation and aggregation of misfolded extracellular proteins. Clusterin is commonly identified at fluid-tissue interfaces, and has been identified in most body fluids. It is a component of exfoliation material, and CLU mRNA is reduced in eyes with exfoliation syndrome compared with controls. SNPs located in the CLU genomic region have been associated with Alzheimer disease (AD) at the genome-wide level and several CLU SNPs located in an apparent regulatory region have been nominally associated with XFS/XFG in Caucasians with European ancestry and in south Indians. Interestingly, clusterin associates with altered elastic fibers in human photoaged skin and prevents UV-induced elastin aggregation in vitro. In light of the known geographic risk factors for XFS/XFG, which could include UV light, investigations of CLU-geographic interactions could be of interest. Future studies investigating rare CLU variation and other complex interactions including gene-gene interactions in XFS/XFG cases and controls may also be fruitful. Although CLU has been considered as a therapeutic target in AD, cancer and dry eye, a role for clusterin in XFS/XFG needs to be better defined before therapeutic approaches involving CLU can be entertained.
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Affiliation(s)
- Janey L. Wiggs
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Jae Hee Kang
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
| | - BaoJian Fan
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Hani Levkovitch-Verbin
- Goldschleger Eye Institute, Tel Hashomer, Sheba Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - Louis R. Pasquale
- Department of Ophthalmology, Mass Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA
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7
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Matukumalli SR, Tangirala R, Rao CM. Clusterin: full-length protein and one of its chains show opposing effects on cellular lipid accumulation. Sci Rep 2017; 7:41235. [PMID: 28120874 PMCID: PMC5264606 DOI: 10.1038/srep41235] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 12/16/2016] [Indexed: 12/31/2022] Open
Abstract
Proteins, made up of either single or multiple chains, are designed to carry out specific biological functions. We found an interesting example of a two-chain protein where administration of one of its chains leads to a diametrically opposite outcome than that reported for the full-length protein. Clusterin is a highly glycosylated protein consisting of two chains, α- and β-clusterin. We have investigated the conformational features, cellular localization, lipid accumulation, in vivo effects and histological changes upon administration of recombinant individual chains of clusterin. We demonstrate that recombinant α- and β-chains exhibit structural and functional differences and differ in their sub-cellular localization. Full-length clusterin is known to lower lipid levels. In contrast, we find that β-chain-treated cells accumulate 2-fold more lipid than controls. Interestingly, α-chain-treated cells do not show such increase. Rabbits injected with β-chain, but not α-chain, show ~40% increase in weight, with adipocyte hypertrophy, liver and kidney steatosis. Many, sometimes contrasting, roles are ascribed to clusterin in obesity, metabolic syndrome and related conditions. Our findings of differential localization and activities of individual chains of clusterin should help in understanding better the roles of clusterin in metabolism.
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Affiliation(s)
| | | | - C. M. Rao
- CSIR- Centre for Cellular and Molecular Biology, Hyderabad, 500007, India
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8
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Bauskar A, Mack WJ, Mauris J, Argüeso P, Heur M, Nagel BA, Kolar GR, Gleave ME, Nakamura T, Kinoshita S, Moradian-Oldak J, Panjwani N, Pflugfelder SC, Wilson MR, Fini ME, Jeong S. Clusterin Seals the Ocular Surface Barrier in Mouse Dry Eye. PLoS One 2015; 10:e0138958. [PMID: 26402857 PMCID: PMC4581869 DOI: 10.1371/journal.pone.0138958] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/04/2015] [Indexed: 12/02/2022] Open
Abstract
Dry eye is a common disorder caused by inadequate hydration of the ocular surface that results in disruption of barrier function. The homeostatic protein clusterin (CLU) is prominent at fluid-tissue interfaces throughout the body. CLU levels are reduced at the ocular surface in human inflammatory disorders that manifest as severe dry eye, as well as in a preclinical mouse model for desiccating stress that mimics dry eye. Using this mouse model, we show here that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to the galectin LGALS3, a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. These findings define a fundamentally new mechanism for ocular surface protection and suggest CLU as a biotherapeutic for dry eye.
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Affiliation(s)
- Aditi Bauskar
- USC Institute for Genetic Medicine and Graduate Program in Medical Biology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
| | - Wendy J. Mack
- Southern California Clinical & Translational Science Institute and Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
| | - Jerome Mauris
- The Schepens Eye Research Institute, Massachusetts Eye & Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pablo Argüeso
- The Schepens Eye Research Institute, Massachusetts Eye & Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Martin Heur
- USC Eye Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
| | - Barbara A. Nagel
- Research Microscopy and Histology Core, Department of Pathology, Saint Louis University School of Medicine, St Louis, Missouri, United States of America
| | - Grant R. Kolar
- Department of Pathology and Department of Ophthalmology, Saint Louis University School of Medicine, St. Louis, Missouri, United States of America
| | - Martin E. Gleave
- The Vancouver Prostate Centre and Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Takahiro Nakamura
- Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Shigeru Kinoshita
- Department of Frontier Medical Science and Technology for Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Janet Moradian-Oldak
- Center for Craniofacial Molecular Biology, Division of Biomedical Sciences, University of Southern California, Herman Ostrow School of Dentistry of USC, Los Angeles, California, United States of America
| | - Noorjahan Panjwani
- New England Eye Center/Department of Ophthalmology and Department of Developmental, Molecular & Chemical Biology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Stephen C. Pflugfelder
- Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, United States of America
| | - Mark R. Wilson
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - M. Elizabeth Fini
- USC Institute for Genetic Medicine and Departments of Cell & Neurobiology and Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
| | - Shinwu Jeong
- USC Institute for Genetic Medicine and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
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9
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Rao VA. Perspectives on Engineering Biobetter Therapeutic Proteins with Greater Stability in Inflammatory Environments. BIOBETTERS 2015. [DOI: 10.1007/978-1-4939-2543-8_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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10
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Martínez‐Bujidos M, Rull A, González‐Cura B, Pérez‐Cuéllar M, Montoliu‐Gaya L, Villegas S, Ordóñez‐Llanos J, Sánchez‐Quesada JL. Clusterin/apolipoprotein J binds to aggregated LDL in human plasma and plays a protective role against LDL aggregation. FASEB J 2014; 29:1688-700. [DOI: 10.1096/fj.14-264036] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/01/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Maria Martínez‐Bujidos
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
- Biochemistry and Molecular Biology DepartmentUniversitat Autònoma de BarcelonaCerdanyolaSpain
| | - Anna Rull
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Beatriz González‐Cura
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Montserrat Pérez‐Cuéllar
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
| | - Laia Montoliu‐Gaya
- Protein Folding and Stability Group, Biochemistry and Molecular Biology DepartmentUniversitat Autònoma de BarcelonaCerdanyolaSpain
| | - Sandra Villegas
- Protein Folding and Stability Group, Biochemistry and Molecular Biology DepartmentUniversitat Autònoma de BarcelonaCerdanyolaSpain
| | - Jordi Ordóñez‐Llanos
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
- Biochemistry and Molecular Biology DepartmentUniversitat Autònoma de BarcelonaCerdanyolaSpain
| | - José Luis Sánchez‐Quesada
- Cardiovascular Biochemistry GroupResearch Institute of the Hospital de Sant Pau (IIB Sant Pau)BarcelonaSpain
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11
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Greene MJ, Klimtchuk ES, Seldin DC, Berk JL, Connors LH. Cooperative stabilization of transthyretin by clusterin and diflunisal. Biochemistry 2014; 54:268-78. [PMID: 25478940 PMCID: PMC4303310 DOI: 10.1021/bi5011249] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
![]()
The
circulating protein transthyretin (TTR) can unfold, oligomerize,
and form highly structured amyloid fibrils that are deposited in tissues,
causing organ damage and disease. This pathogenic process is caused
by a heritable TTR point mutation in cases of familial TTR-related
amyloidosis or wild-type TTR in cases of age-associated amyloidosis
(previously called senile systemic amyloidosis). The TTR amyloid cascade
is hypothesized to begin with the dissociation of the TTR native tetrameric
structure into folded but unstable monomeric TTR subunits. Unfolding
of monomeric TTR initiates an oligomerization process leading to aggregation
and fibril formation. Numerous proteostatic mechanisms for regulating
the TTR amyloid cascade exist. Extracellular chaperones provide an
innate defense against misfolded proteins. Clusterin (CLU), a plasma
protein, has the capacity to recognize exposed hydrophobic regions
of misfolded proteins, shielding them from aggregation. We have previously
demonstrated that CLU is associated with the amyloid fibrils in cardiac
tissues from patients with TTR amyloidosis. In this study, we have
used tetrameric and monomeric TTR structural variants to determine
the ability of CLU to inhibit TTR amyloid fibril formation. Using
circular dichroism spectroscopy, we determined that CLU preferentially
stabilizes monomeric TTR and generates increasingly stable conformations
under acid stress. Moreover, studies using surface plasmon resonance
showed a direct interaction of CLU with high-molecular weight TTR
oligomers. The interactions of CLU with monomeric and aggregated TTR
proceed in a cooperative manner in the presence of diflunisal, a small
molecule drug used to stabilize TTR tetramers.
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Affiliation(s)
- Michael J Greene
- Amyloidosis Center, Boston University School of Medicine , K-507, 715 Albany Street, Boston, Massachusetts 02118, United States
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12
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Sluchanko NN, Roman SG, Chebotareva NA, Gusev NB. Chaperone-like activity of monomeric human 14-3-3ζ on different protein substrates. Arch Biochem Biophys 2014; 549:32-9. [PMID: 24681339 DOI: 10.1016/j.abb.2014.03.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/05/2014] [Accepted: 03/18/2014] [Indexed: 12/28/2022]
Abstract
Members of the 14-3-3 protein family interact with hundreds of different, predominantly phosphorylated, proteins. 14-3-3 dimers are prevalent but exist at the equilibrium with the monomers. Our previous studies using the engineered monomeric 14-3-3ζ (14-3-3ζm) showed that 14-3-3ζ monomer retained binding activity towards selected phosphorylated partners and, in addition, it prevented heat-induced aggregation of myosin subfragment 1. Since the chaperone-like activity of 14-3-3 monomers has been insufficiently studied, here we have analyzed the effect of 14-3-3ζm on the aggregation of different model proteins. We found that 14-3-3ζm demonstrated considerable chaperone-like activity by inhibiting the DTT-induced aggregation of insulin and thermally-induced aggregation of alcohol dehydrogenase and phosphorylase kinase. Importantly, the anti-aggregating activity of 14-3-3ζm was concentration-dependent and overall, was more pronounced than that of its dimeric counterpart. In some cases, the chaperone-like effect of 14-3-3ζm was comparable, or even higher, than that of the small heat shock proteins, HspB6 and HspB5. We suggest that 14-3-3s not only can bind and regulate the activity of multiple phosphoproteins, but also possess moonlighting chaperone-like activity, which is especially pronounced in the case of monomeric forms of 14-3-3 which can be present under certain stress conditions.
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Affiliation(s)
- Nikolai N Sluchanko
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Prospect 33, Moscow 119071, Russian Federation.
| | - Svetlana G Roman
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Prospect 33, Moscow 119071, Russian Federation
| | - Natalia A Chebotareva
- A. N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky Prospect 33, Moscow 119071, Russian Federation
| | - Nikolai B Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119991, Russian Federation
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13
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Abstract
Clusterin, also known as apolipoprotein J, is a ubiquitous multifunctional glycoprotein. Following its identification in 1983, clusterin was found to be clearly increased in Alzheimer's disease (AD). Later research demonstrated that clusterin could bind amyloid-beta (Abeta) peptides and prevent fibril formation, a hallmark of AD pathology. In addition to preventing excessive inflammation, intracellular clusterin was found to reduce apoptosis and oxidative stress. Although early studies were inconclusive, two recent large-scale genome-wide association studies (GWAS) independently identified variants within the clusterin gene as risk factors for developing AD. This review focuses on the characteristics of clusterin and possible mechanisms of its relationship to AD.
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Affiliation(s)
- Zhong-Chen Wu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong Province, China
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14
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Peptides modulating conformational changes in secreted chaperones: from in silico design to preclinical proof of concept. Proc Natl Acad Sci U S A 2009; 106:13797-801. [PMID: 19666568 DOI: 10.1073/pnas.0906514106] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Blocking conformational changes in biologically active proteins holds therapeutic promise. Inspired by the susceptibility of viral entry to inhibition by synthetic peptides that block the formation of helix-helix interactions in viral envelope proteins, we developed a computational approach for predicting interacting helices. Using this approach, which combines correlated mutations analysis and Fourier transform, we designed peptides that target gp96 and clusterin, 2 secreted chaperones known to shift between inactive and active conformations. In human blood mononuclear cells, the gp96-derived peptide inhibited the production of TNFalpha, IL-1beta, IL-6, and IL-8 induced by endotoxin by >80%. When injected into mice, the peptide reduced circulating levels of endotoxin-induced TNFalpha, IL-6, and IFNgamma by >50%. The clusterin-derived peptide arrested proliferation of several neoplastic cell lines, and significantly enhanced the cytostatic activity of taxol in vitro and in a xenograft model of lung cancer. Also, the predicted mode of action of the active peptides was experimentally verified. Both peptides bound to their parent proteins, and their biological activity was abolished in the presence of the peptides corresponding to the counterpart helices. These data demonstrate a previously uncharacterized method for rational design of protein antagonists.
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15
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Nuutinen T, Suuronen T, Kauppinen A, Salminen A. Clusterin: a forgotten player in Alzheimer's disease. ACTA ACUST UNITED AC 2009; 61:89-104. [PMID: 19651157 DOI: 10.1016/j.brainresrev.2009.05.007] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/16/2022]
Abstract
Clusterin, also known as apolipoprotein J, is a versatile chaperone molecule which contains several amphipathic and coiled-coil alpha-helices, typical characteristics of small heat shock proteins. In addition, clusterin has three large intrinsic disordered regions, so-called molten globule domains, which can stabilize stressed protein structures. Twenty years ago, it was demonstrated that the expression of clusterin was clearly increased in Alzheimer's disease (AD). Later it was observed that clusterin can bind amyloid-beta peptides and prevent their fibrillization. Clusterin is also involved in the clearance of amyloid-beta peptides and fibrils by binding to megalin receptors and enhancing their endocytosis within glial cells. Clusterin is a complement inhibitor and can suppress complement activation observed in AD. Clusterin is also present in lipoprotein particles and regulates cholesterol and lipid metabolism of brain which is disturbed in AD. Clusterin is a stress-induced chaperone which is normally secreted but in conditions of cellular stress, it can be transported to cytoplasm where it can bind to Bax protein and inhibit neuronal apoptosis. Clusterin can also bind to Smad2/3 proteins and potentiate the neuroprotective TGFbeta signaling. An alternative splicing can produce a variant isoform of clusterin which can be translocated to nuclei where it induces apoptosis. The role of nuclear clusterin in AD needs to be elucidated. We will review here the extensive literature linking clusterin to AD and examine the recent progress in clusterin research with the respect to AD pathology. Though clusterin can be viewed as a multipotent guardian of brain, it is unable to prevent the progressive neuropathology in chronic AD.
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Affiliation(s)
- Tapio Nuutinen
- Department of Neuroscience and Neurology, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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16
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pH-, temperature- and ion-dependent oligomerization of Sulfolobus solfataricus recombinant amidase: a study with site-specific mutants. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2009; 2:221-31. [PMID: 19478917 DOI: 10.1155/2009/280317] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 12/22/2008] [Indexed: 11/17/2022]
Abstract
Recombinant amidase from Sulfolobus solfataricus occurred as a dimer of 110 kDa comprising identical subunits. Only dimers were present at pHs above 7.0, but with decreasing pH, dimers associated into octamers, with complete oligomerization occurring at pH 3.0. Oligomerization showed reversible temperature-dependence, with octamer formation increasing with temperature from 36 degrees C to between 70 and 80 degrees C. Increasing salt concentrations, favored dissociation of the octamers. Among the three investigated factors affecting the dimer-octamer equilibrium, the most important was pH. Among four mutants obtained by site-specific mutagenesis and selection for pH and temperature sensitivity, the T319I and D487N mutant amidases, like that of the native Sulfolobus solfataricus, responded to changes in pH and temperature with a conformational change affecting the dimer-octamer equilibrium. The Y41C and L34P mutant amidases were unaffected by pH and temperature, remaining always in the dimeric state. The differences among mutants in protein conformation must be related to the position of the introduced mutation. Although the L34P and Y41C mutations are located in the helical region 33-48 (LLKLQLESYERLDSLP), which is close to the amino-terminal segment of the protein, the T319I mutation is located in a strand on the surface of the protein, which is far from, and opposite to, the amino-terminal segment. The D487N mutation is located in the center of the protein, far distant from the 33-48 segment. These observations suggest that the segment of the protein closest to the amino-terminus plays a key role in the association of dimers into octamers.
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17
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Wilson MR, Yerbury JJ, Poon S. Potential roles of abundant extracellular chaperones in the control of amyloid formation and toxicity. ACTA ACUST UNITED AC 2008; 4:42-52. [DOI: 10.1039/b712728f] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Imhof A, Charnay Y, Vallet PG, Aronow B, Kovari E, French LE, Bouras C, Giannakopoulos P. Sustained astrocytic clusterin expression improves remodeling after brain ischemia. Neurobiol Dis 2006; 22:274-83. [PMID: 16473512 DOI: 10.1016/j.nbd.2005.11.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2005] [Revised: 11/15/2005] [Accepted: 11/17/2005] [Indexed: 11/16/2022] Open
Abstract
Clusterin is a glycoprotein highly expressed in response to tissue injury. Using clusterin-deficient (Clu-/-) mice, we investigated the role of clusterin after permanent middle cerebral artery occlusion (MCAO). In wild-type (WT) mice, clusterin mRNA displayed a sustained increase in the peri-infarct area from 14 to 30 days post-MCAO. Clusterin transcript was still present up to 90 days post-ischemia in astrocytes surrounding the core infarct. Western blot analysis also revealed an increase of clusterin in the ischemic hemisphere of WT mice, which culminates up to 30 days post-MCAO. Concomitantly, a worse structural restoration and higher number of GFAP-reactive astrocytes in the vicinity of the infarct scar were observed in Clu-/- as compared to WT mice. These findings go beyond previous data supporting a neuroprotective role of clusterin in early ischemic events in that they demonstrate that this glycoprotein plays a central role in the remodeling of ischemic damage.
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Affiliation(s)
- Anouk Imhof
- Department of Psychiatry, HUG, Belle-Idée, 2, ch. du Petit-Bel-Air, 1225 Chêne-Bourg Geneva Switzerland
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D’Abusco AS, Casadio R, Tasco G, Giangiacomo L, Giartosio A, Calamia V, Di Marco S, Chiaraluce R, Consalvi V, Scandurra R, Politi L. Oligomerization of Sulfolobus solfataricus signature amidase is promoted by acidic pH and high temperature. ARCHAEA-AN INTERNATIONAL MICROBIOLOGICAL JOURNAL 2006; 1:411-23. [PMID: 16243781 PMCID: PMC2685583 DOI: 10.1155/2005/543789] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The recombinant amidase from the hyperthermophylic archaeon Sulfolobus solfataricus (SSAM) a signature amidase, was cloned, purified and characterized. The enzyme is active on a large number of aliphatic and aromatic amides over the temperature range 60-95 degrees C and at pH values between 4.0 and 9.5, with an optimum at pH 5.0. The recombinant enzyme is in the form of a dimer of about 110 kD that reversibly associates into an octamer in a pH-dependent reaction. The pH dependence of the state of association was studied using gel permeation chromatography, analytical ultracentrifugation and dynamic light scattering techniques. At pH 7.0 all three techniques show the presence of two species, in about equal amounts, which is compatible with the existence of a dimeric and an octameric form. In decreasing pH, the dimers formed the octameric species and in increasing pH, the octameric species was converted to dimers. Above pH 8.0, only dimers were present, below pH 3.0 only octamers were present. The association of dimers into octamers decreased in non-polar solvents and increased with temperature. A mutant (Y41C) was obtained that did not show this behavior.
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Affiliation(s)
- Anna Scotto D’Abusco
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | - Rita Casadio
- CIRB Biocomputing Group, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - Gianluca Tasco
- CIRB Biocomputing Group, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - Laura Giangiacomo
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | - Anna Giartosio
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | - Valentina Calamia
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | | | - Roberta Chiaraluce
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | - Valerio Consalvi
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
| | - Roberto Scandurra
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
- Corresponding author ()
| | - Laura Politi
- Dipartimento di Scienze Biochimiche “A. Rossi-Fanelli,” Università “La Sapienza,” P.le A. Moro 5, 00185 Roma, Italy
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20
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Guns ES, Xie X, Fedoruk M, Madera C, Cowell S, Mayer LD, Skov K, Gleave ME, Kozlowski P. pH modulation using CsCl enhances therapeutic effects of vitamin D in LNCaP tumor bearing mice. Prostate 2005; 64:316-22. [PMID: 15754319 DOI: 10.1002/pros.20257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND The downstream effects of pH modulation significantly impact the biological fate of chemotherapeutic agents and tumor responsiveness to therapy. We have studied the effects of cesium chloride (CsCl) on pH modulation and subsequent vitamin D treatment in vitamin D receptor (VDR) positive LNCaP tumors and VDR null MDA/LCC6 tumors in vivo. METHODS Mice bearing LNCaP or MDA/LCC6 tumors were dosed orally with CsCl (150 mg/kg) or vitamin D (1 microg/kg) alone and in combination. Tumor volume and serum PSA (LNCaP only) were measured and intracellular pH was determined, using magnetic resonance spectroscopy (MRS), at tumor and leg muscle sites. Atomic absorption spectroscopy (AAS) was used to quantitate cesium in serum, organs, and tumor tissues. RESULTS From day 10 onwards, statistically significant (P<0.01) differences were observed in all LNCaP treated groups as compared with control. CsCl co-administered with vitamin D, caused an apparent sensitization of efficacy in this tumor model. There were no correlating differences in serum PSA. Elevation of pH was statistically significant for all three treatment groups as compared with control. The pH measured in leg muscle was not influenced by CsCl treatment. Inhibition of tumor growth was not apparent in VDR null MDA/LCC6 tumors although intracellular tumor pH was shifted. Cesium was rapidly absorbed into serum and present in LNCaP tumors, prostates and other tissues after 1 hr, remaining for up to 24 hr. CONCLUSIONS The data presented in this manuscript is the first report of chemosensitization by in vivo pH modulation using CsCl in mice bearing prostate or any other tumor xenograft.
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Affiliation(s)
- Emma S Guns
- The Prostate Centre at Vancouver General Hospital, Vancouver, British Columbia, Canada
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21
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Chernik IS, Panasenko OO, Li Y, Marston SB, Gusev NB. pH-induced changes of the structure of small heat shock proteins with molecular mass 24/27kDa (HspB1). Biochem Biophys Res Commun 2004; 324:1199-203. [PMID: 15504341 DOI: 10.1016/j.bbrc.2004.09.176] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2004] [Indexed: 10/26/2022]
Abstract
The effect of pH on the structure of recombinant chicken Hsp24, human Hsp27 and their 3D mutants mimicking phosphorylation at Ser15, Ser77/78, and Ser81/82 was analyzed. Circular dichroism and fluorescent spectroscopy indicate that changes of pH in the range 6.0-7.5 weakly affected the secondary and tertiary structure of the wild type proteins, but induced noticeable changes in the structure of their 3D mutants. According to size-exclusion chromatography and analytical ultracentrifugation variation of pH-induced pronounced changes in the quaternary structure of small heat shock proteins and acidification resulted in accumulation of large oligomers of Hsp24/27. It is concluded that small changes of pH strongly affect the quaternary structure of small heat shock proteins and by this means can influence their functioning in the cell.
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Affiliation(s)
- Ivan S Chernik
- Department of Biochemistry, School of Biology, Moscow State University, Moscow 119992, Russia
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22
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Pinho D, Besson S, Brondino CD, Pereira E, de Castro B, Moura I. Two azurins with unusual redox and spectroscopic properties isolated from the Pseudomonas chlororaphis strains DSM 50083T and DSM 50135. J Inorg Biochem 2004; 98:276-86. [PMID: 14729308 DOI: 10.1016/j.jinorgbio.2003.10.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Two azurins (Az624 and Az626) were isolated from the soluble extract of two strains of Pseudomonas chlororaphis, DSM 50083(T) and DSM 50135, respectively, grown under microaerobic conditions with nitrate as final electron acceptor. The azurins, purified to electrophoretic homogeneity in three chromatographic steps, exhibit several peculiar properties. They have high reduction potentials and lower pI than most azurins described in the literature. As previously observed for Pseudomonas aeruginosa azurin, their reduction potentials are pH-dependent, but the pK values of their oxidized forms are lower, which suggests that deeper structural changes are associated with the oxidation process of these novel azurins. A hitherto undescribed pH-dependence of the diffusion coefficient was observed in Az624, that could be caused either by conformational changes, or by the formation of supramolecular aggregates associated with a protonation process. Both azurins exhibit axial X-band electron paramagnetic resonance spectra in frozen solution showing a typical hyperfine with the copper nucleus (I=3/2) and a well-resolved superhyperfine structure with two equivalent 14N nucleus (I=1), which is not usually observed for azurins from other species.
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Affiliation(s)
- Dora Pinho
- REQUIMTE, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Porto 4169-007, Portugal
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23
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Poon S, Rybchyn MS, Easterbrook-Smith SB, Carver JA, Pankhurst GJ, Wilson MR. Mildly acidic pH activates the extracellular molecular chaperone clusterin. J Biol Chem 2002; 277:39532-40. [PMID: 12176985 DOI: 10.1074/jbc.m204855200] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many features of the chaperone action of clusterin are similar to those of the intracellular small heat shock proteins (sHSPs) that, like clusterin, exist in solution as heterogeneous aggregates. Increased temperature induces dissociation of some sHSP aggregates and an enhanced chaperone action, suggesting that a dissociated form is the active chaperone species. We recently reported that clusterin aggregates dissociate at mildly acidic pH. To further explore the similarities between clusterin and the sHSPs, we tested the effects of temperature and pH on the structure of clusterin and its chaperone action. Our results demonstrate that increased temperature does not induce dissociation of clusterin aggregates, or other major structural changes, and has little effect on its chaperone action. However, we show that the chaperone action of clusterin is enhanced at mildly acidic pH. Clusterin is the first chaperone shown to be activated by reduced pH. This unique mode of activation appears to result from an increase in regions of solvent-exposed hydrophobicity, which is independent of any major changes in secondary or tertiary structure. We propose a model in which low pH-induced dissociation of clusterin aggregates increases the abundance of the heterodimeric chaperone-active species, which has greater hydrophobicity exposed to solution.
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Affiliation(s)
- Stephen Poon
- Department of Biological Sciences, University of Wollongong, Northfields Ave., Wollongong, New South Wales 2522, Australia
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24
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Hatters DM, Wilson MR, Easterbrook-Smith SB, Howlett GJ. Suppression of apolipoprotein C-II amyloid formation by the extracellular chaperone, clusterin. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2789-94. [PMID: 12047389 DOI: 10.1046/j.1432-1033.2002.02957.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effect of the extracellular chaperone, clusterin, on amyloid fibril formation by lipid-free human apolipoprotein C-II (apoC-II) was investigated. Sub-stoichiometric levels of clusterin, derived from either plasma or semen, potently inhibit amyloid formation by apoC-II. Inhibition is dependent on apoC-II concentration, with more effective inhibition by clusterin observed at lower concentrations of apoC-II. The average sedimentation coefficient of apoC-II fibrils formed from apoC-II (0.3 mg.mL-1) is reduced by coincubation with clusterin (10 microg x mL(-1)). In contrast, addition of clusterin (0.1 mg x mL(-1)) to preformed apoC-II amyloid fibrils (0.3 mg x mL(-1)) does not affect the size distribution after 2 days. This sedimentation velocity data suggests that clusterin inhibits fibril growth but does not promote fibril dissociation. Electron micrographs indicate similar morphologies for amyloid fibrils formed in the presence or absence of clusterin. The substoichiometric nature of the inhibition suggests that clusterin interacts with transient amyloid nuclei leading to dissociation of the monomeric subunits. We propose a general role for clusterin in suppressing the growth of extracellular amyloid.
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Affiliation(s)
- Danny M Hatters
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Victoria, Australia
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25
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Poon S, Treweek TM, Wilson MR, Easterbrook-Smith SB, Carver JA. Clusterin is an extracellular chaperone that specifically interacts with slowly aggregating proteins on their off-folding pathway. FEBS Lett 2002; 513:259-66. [PMID: 11904161 DOI: 10.1016/s0014-5793(02)02326-8] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Clusterin is an extracellular mammalian chaperone protein which inhibits stress-induced precipitation of many different proteins. The conformational state(s) of proteins that interact with clusterin and the stage(s) along the folding and off-folding (precipitation-bound) pathways where this interaction occurs were previously unknown. We investigated this by examining the interactions of clusterin with different structural forms of alpha-lactalbumin, gamma-crystallin and lysozyme. When assessed by ELISA and native gel electrophoresis, clusterin did not bind to various stable, intermediately folded states of alpha-lactalbumin nor to the native form of this protein, but did bind to and inhibit the slow precipitation of reduced alpha-lactalbumin. Reduction-induced changes in the conformation of alpha-lactalbumin, in the absence and presence of clusterin, were monitored by real-time (1)H NMR spectroscopy. In the absence of clusterin, an intermediately folded form of alpha-lactalbumin, with some secondary structure but lacking tertiary structure, aggregated and precipitated. In the presence of clusterin, this form of alpha-lactalbumin was stabilised in a non-aggregated state, possibly via transient interactions with clusterin prior to complexation. Additional experiments demonstrated that clusterin potently inhibited the slow precipitation, but did not inhibit the rapid precipitation, of lysozyme and gamma-crystallin induced by different stresses. These results suggest that clusterin interacts with and stabilises slowly aggregating proteins but is unable to stabilise rapidly aggregating proteins. Collectively, our results suggest that during its chaperone action, clusterin preferentially recognises partly folded protein intermediates that are slowly aggregating whilst venturing along their irreversible off-folding pathway towards a precipitated protein.
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Affiliation(s)
- Stephen Poon
- Department of Chemistry, University of Wollongong, Northfields Avenue, 2522, Wollongong, NSW, Australia
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26
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Charlwood J, Hanrahan S, Tyldesley R, Langridge J, Dwek M, Camilleri P. Use of proteomic methodology for the characterization of human milk fat globular membrane proteins. Anal Biochem 2002; 301:314-24. [PMID: 11814302 DOI: 10.1006/abio.2001.5498] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Characterization of the major human milk fat globular membrane proteins was carried out using proteomic techniques comprising two-dimensional polyacrylamide gel electrophoresis, followed by in situ PNGase F and trypsin digestion. Matrix-assisted laser desorption/ionization quadrupole time-of-flight and electrospray ionization mass spectrometry identified seven major protein components: alpha-lactalbumin, lysozyme precursor, beta-casein, clusterin, lactotransferrin, polymeric immunoglobulin receptor precursor, and human milk fat globule EGF-factor 8 protein. Sequence information on the protein-associated glycans was determined by matrix-assisted laser desorption-ionization quadrupole time-of-flight hybrid mass spectrometry. This glycan analysis revealed interesting fucosylation branching patterns which may be influential in maternal protection of the newborn against bacterial and viral pathogenic attack.
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Affiliation(s)
- Joanne Charlwood
- New Frontiers Science Park, GlaxoSmithKline, Third Avenue, Harlow, Essex, CM19 5AW, United Kingdom
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27
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Gerritsen HE, Robles R, Lämmle B, Furlan M. Partial amino acid sequence of purified von Willebrand factor-cleaving protease. Blood 2001; 98:1654-61. [PMID: 11535494 DOI: 10.1182/blood.v98.6.1654] [Citation(s) in RCA: 274] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
von Willebrand factor-cleaving protease (vWF-cp) is responsible for the continuous degradation of plasma vWF multimers released from endothelial cells. It is deficient in patients with thrombotic thrombocytopenic purpura, who show unusually large vWF multimers in plasma. Purified vWF-cp may be useful for replacement in these patients, who are now treated by plasma therapy. In this study, vWF-cp was purified from normal human plasma by affinity chromatography on the IgG fraction from a patient with autoantibodies to vWF-cp and by a series of further chromatographic procedures, including affinity chromatography on Protein G, Ig-TheraSorb, lentil lectin, and heparin. Four single-chain protein bands, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreducing conditions, showed M(r) of 150, 140, 130, and 110 kd and were found to share the same N-terminal amino acid sequence, suggesting that they were derived from the same polypeptide chain that had been partially degraded at the carboxy-terminal end. A hydrophobic sequence (Ala-Ala-Gly-Gly-Ile-Leu-His-Leu-Glu-Leu-Leu-Val-Ala-Val-Gly) of the first 15 residues was established. The protease migrates in gel filtration as a high-molecular-weight complex with clusterin, a 70-kd protein with chaperonelike activity. vWF-cp bound to clusterin is dissociated by the use of concentrated chaotropic salts. vWF-cp in normal human plasma or serum is not associated with clusterin, suggesting that the observed complex is due to vWF-cp denaturation during the purification procedure. Activity of vWF-cp is unusually stable during incubation at 37 degrees C; its in vitro half-life in citrated human plasma, heparin plasma, or serum is longer than 1 week. There was even a temporary increase in protease activity during the first 3 days of incubation.
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Affiliation(s)
- H E Gerritsen
- Central Hematology Laboratory, University Hospital, Inselspital, Bern, Switzerland
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