f.j. gonzalez-velasquez, j.w. reed, j.w. fuseler, j.a. kotarek, d.d. soto-ortega, and m.a. moss
DESCRIPTION
Activation of endothelium in Alzheimer ’ s brain involves soluble aggregates of the amyloid- b protein. F.J. Gonzalez-Velasquez, J.W. Reed, J.W. Fuseler, J.A. Kotarek, D.D. Soto-Ortega, and M.A. Moss University of South Carolina. College of Engineering and Computing - PowerPoint PPT PresentationTRANSCRIPT
Activation of endothelium in Alzheimer’s brain involves soluble aggregates of the amyloid-protein
F.J. Gonzalez-Velasquez, J.W. Reed,J.W. Fuseler, J.A. Kotarek,
D.D. Soto-Ortega, and M.A. Moss
University of South Carolina
College of Engineering and ComputingUniversity of South Carolina
College of Engineering and ComputingUniversity of South Carolina
Alzheimer’s Pathology
Alzheimer’s Brain
Pathology
A Fibrils
Nichols et al. (2002)Biochemistry, 41: 6115-27.
Courtesy of D. Dickson,Mayo Clinic, Jacksonville.
Cerebral AmyloidAngiopathy
http://www.adrc.wustl.edu/adrc2.html
Amyloid Plaques
College of Engineering and ComputingUniversity of South Carolina
Cerebral Amyloid Angiopathy
• Characterized by deposition of A in the cerebrovasculature– Primarily A1-40
• Identified in over 90% of AD patients• A mutations: Dutch, Italian, Iowa, and
Arctic– Dutch and Italian mutations result exclusively in CAA
• Associated with an increased risk of hemorrhagic stroke
• Correlates with disease progression
Washington University ADRC
College of Engineering and ComputingUniversity of South Carolina
A and Endothelium
Cellular degeneration
Compromised BBB integrity
Increased vessel-associated monocyte cells
ToxicityIncreased permeabilityIncreased monocyte
adhesion, transmigration
Upregulated adhesion molecule expression
Washington University ADRC
Cerebrovasculature Cell Culture
College of Engineering and ComputingUniversity of South Carolina
Research Questions…
What form of A interacts with endothelial cells to promote activation
What signaling pathways are involved
monomer
nucleus
soluble intermediate
s
fibril
College of Engineering and ComputingUniversity of South Carolina
Isolation of A Species
Mixture
150 mMNaCl
2-10 mMNaCl
Fibrils
College of Engineering and ComputingUniversity of South Carolina
A model endothelium exhibitingblood-brain barrier properties was developed
Gonzalez-Velasquez and Moss (2008) J Neurochem, 104: 500-13.
College of Engineering and ComputingUniversity of South Carolina
Endothelial Cell Assays
Adhesion Transmigration Permeability
permeabilitycoefficient
Pe
%transmigrated
cells
%adherent
cells
College of Engineering and ComputingUniversity of South Carolina
Soluble A aggregates selectively activate endothelial cells
MIX MON SOL FIB
Gonzalez-Velasquez and Moss (2008) J Neurochem, 107: 466-77;Gonzalez-Velasquez, Kotarek, and Moss (2008) J Neurochem, 104: 500-14.
College of Engineering and ComputingUniversity of South Carolina
Endothelial activation ismore pronouncedin the presence of smaller soluble Aaggregationintermediates
Gonzalez-Velasquez and Moss (2008) J Neurochem, 107: 466-77;Gonzalez-Velasquez, Kotarek, and Moss (2008) J Neurochem, 104: 500-14.
Adhesion Permeability
College of Engineering and ComputingUniversity of South Carolina
NF-B and A
• NF-B is involved in the activation of endothelium – Adhesion molecule
upregulation
– Permeability
• A is capable of activating NF-B– Neuronal cells
– Glial cells
• A can activate NF-B via binding of several receptors– Receptor for advanced
glycation end products (RAGE)
– Toll-like receptors (TLRs)Hayden and Ghosh (2008) Cell,
132:344-62.
College of Engineering and ComputingUniversity of South Carolina
CONT TNF
MON SOL
MIX
FIB
NF-B nuclear translocation is selectively stimulated by soluble A aggregates
Gonzalez-Velasquez, Reed, et al, and Moss (2010) Curr Alzheimer Res, 8: 81-94.
.
College of Engineering and ComputingUniversity of South Carolina
NF-B activation is observed at physiological concentrations of A
Gonzalez-Velasquez, Reed, et al, and Moss (2011) Curr Alzheimer Res, 8: 81-94.
College of Engineering and ComputingUniversity of South Carolina
CONT MON MIX FIB0
10
20
30
40
***
% A
dhes
ion
CONT MON MIX FIB0
10
20
30
40
***
% T
rans
mig
rati
on
Inhibiting NF-B nucleartranslocation abrogatesA-induced adhesion,transmigration, andpermeability
Control MG 132
Gonzalez-Velasquez, Reed, et al, and Moss (2011) Curr Alzheimer Res, 8: 81-94.
College of Engineering and ComputingUniversity of South Carolina
Summary
• A is capable of activating endothelial monolayers– Monocyte adhesion– Monocyte transmigration– Permeability
• Specifically, soluble A aggregation intermediates are responsible for endothelial activation
• Smaller soluble aggregation intermediates are the most potent activators of the endothelium
• NF-B signaling is involved in A activation of endothelial monolayers
College of Engineering and ComputingUniversity of South Carolina
Research AssociateFrancisco Gonzalez-Velasquez
Undergraduate StudentsCharlotte CooperTim DavisAnthony EgalMcCall RogersEmily Matherly
Graduate StudentsAdriana Reyes BarceloJoseph KotarekWill ReedDeborah Soto-OrtegaChen SuoJui-Heng TsengKelly Wilson
AcknowledgementsNational Science Foundation
CAREER Award (BES 0644826)
American Heart Association, Mid-Atlantic AffiliateBeginning Grant-In-Aid (0565387U)
Alzheimer’s AssociationNew Investigator Research Grant (NIRG-07-60412)
USC Complementary and Alternative Medicine Center
Activation of endothelium in Alzheimer’s brain involves soluble aggregates of the amyloid- protein
F.J. Gonzalez-Velasquez, J.W. Reed,J.W. Fuseler, J.A. Kotarek,
D.D. Soto-Ortega, and M.A. Moss
University of South Carolina
College of Engineering and ComputingUniversity of South Carolina