Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion

α2-Macroglobulin (α2M) is an abundant plasma/extracellular space protein implicated in clearance of amyloid β (Aβ), a key constituent of Alzheimer's disease (AD) plaques. α2M also regulates proteinase and growth factor activities. In recent years, there have been >30 genetic studies debating...

Full description

Bibliographic Details
Main Authors: Caroline Hope, Joseph Mettenburg, Steven L Gonias, Steven T DeKosky, M.Ilyas Kamboh, Charleen T Chu
Format: Article
Language:English
Published: Elsevier 2003-12-01
Series:Neurobiology of Disease
Online Access:http://www.sciencedirect.com/science/article/pii/S0969996103001505
_version_ 1818862587324923904
author Caroline Hope
Joseph Mettenburg
Steven L Gonias
Steven T DeKosky
M.Ilyas Kamboh
Charleen T Chu
author_facet Caroline Hope
Joseph Mettenburg
Steven L Gonias
Steven T DeKosky
M.Ilyas Kamboh
Charleen T Chu
author_sort Caroline Hope
collection DOAJ
description α2-Macroglobulin (α2M) is an abundant plasma/extracellular space protein implicated in clearance of amyloid β (Aβ), a key constituent of Alzheimer's disease (AD) plaques. α2M also regulates proteinase and growth factor activities. In recent years, there have been >30 genetic studies debating the controversial role of a five-base-pair intronic deletion in the A2M gene in late-onset AD. However, little is known about potential effects of the deletion upon α2M function. In this study, we examined the subunit and conformational structure of α2M in AD plasma samples, and its capacity to bind trypsin, transforming growth factor-β1, and Aβ. Plasma from patients homozygous for the deletion (DD) showed normal α2M subunit size, conformation, and proteinase inhibitory activity. Interestingly, plasma α2M from two DD patients showed markedly increased TGF-β1 binding. Moreover, methylamine-treated DD plasma samples showed modest, but significant, elevations in Aβ binding to α2M* compared with samples from patients lacking the deletion. These observations suggest a possible functional basis by which the A2M deletion may influence multifactorial AD pathogenesis.
first_indexed 2024-12-19T10:02:14Z
format Article
id doaj.art-6db2b9a4af5c4726a52ef835cab71155
institution Directory Open Access Journal
issn 1095-953X
language English
last_indexed 2024-12-19T10:02:14Z
publishDate 2003-12-01
publisher Elsevier
record_format Article
series Neurobiology of Disease
spelling doaj.art-6db2b9a4af5c4726a52ef835cab711552022-12-21T20:26:37ZengElsevierNeurobiology of Disease1095-953X2003-12-01143504512Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletionCaroline Hope0Joseph Mettenburg1Steven L Gonias2Steven T DeKosky3M.Ilyas Kamboh4Charleen T Chu5Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USADepartment of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USADepartment of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USADepartment of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USADepartment of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USADepartment of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22908, USA; Department of Pathology, University of Virginia, Charlottesville, VA 22908, USA; Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15213, USA; Pittsburgh Institute of Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USAα2-Macroglobulin (α2M) is an abundant plasma/extracellular space protein implicated in clearance of amyloid β (Aβ), a key constituent of Alzheimer's disease (AD) plaques. α2M also regulates proteinase and growth factor activities. In recent years, there have been >30 genetic studies debating the controversial role of a five-base-pair intronic deletion in the A2M gene in late-onset AD. However, little is known about potential effects of the deletion upon α2M function. In this study, we examined the subunit and conformational structure of α2M in AD plasma samples, and its capacity to bind trypsin, transforming growth factor-β1, and Aβ. Plasma from patients homozygous for the deletion (DD) showed normal α2M subunit size, conformation, and proteinase inhibitory activity. Interestingly, plasma α2M from two DD patients showed markedly increased TGF-β1 binding. Moreover, methylamine-treated DD plasma samples showed modest, but significant, elevations in Aβ binding to α2M* compared with samples from patients lacking the deletion. These observations suggest a possible functional basis by which the A2M deletion may influence multifactorial AD pathogenesis.http://www.sciencedirect.com/science/article/pii/S0969996103001505
spellingShingle Caroline Hope
Joseph Mettenburg
Steven L Gonias
Steven T DeKosky
M.Ilyas Kamboh
Charleen T Chu
Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
Neurobiology of Disease
title Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
title_full Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
title_fullStr Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
title_full_unstemmed Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
title_short Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion
title_sort functional analysis of plasma α2 macroglobulin from alzheimer s disease patients with the a2m intronic deletion
url http://www.sciencedirect.com/science/article/pii/S0969996103001505
work_keys_str_mv AT carolinehope functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion
AT josephmettenburg functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion
AT stevenlgonias functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion
AT steventdekosky functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion
AT milyaskamboh functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion
AT charleentchu functionalanalysisofplasmaa2macroglobulinfromalzheimersdiseasepatientswiththea2mintronicdeletion