 |
The Journal of Neuroscience, June 14, 2006, 26(24):6533-6542; doi:10.1523/JNEUROSCI.5567-05.2006
Previous Article | Next Article 
Neurobiology of Disease
Phosphorylation of Actin-Depolymerizing Factor/Cofilin by LIM-Kinase Mediates Amyloid -Induced Degeneration: A Potential Mechanism of Neuronal Dystrophy in Alzheimer's Disease
Lorena Heredia,1
Pablo Helguera,4
Soledad de Olmos,2
Gabriela Kedikian,1
Francisco Solá Vigo,1
Frank LaFerla,4
Matthias Staufenbiel,5
José de Olmos,2
Jorge Busciglio,4
Alfredo Cáceres,3 and
Alfredo Lorenzo1
Laboratories of 1Experimental Neuropathology, 2Neuroanatomy, and 3 Cell Biology, Instituto de Investigación Médica "Mercedes y Martín Ferreyra"/Consejo Nacional de Investigaciones Científicas y Técnicas, 5000 Córdoba, Argentina, 4Department of Neurobiology and Behavior, University of California, Irvine, California 92697-4550, and 5Novartis Institute for BioMedical Research Basel, Inc., CH-4002 Basel, Switzerland
Correspondence should be addressed to Dr. Alfredo Lorenzo, Laboratory of Experimental Neuropathology, Instituto de Investigación Médica "Mercedes y Martín Ferreyra"/Consejo Nacional de Investigaciones Científicas y Técnicas, Casilla de Correo 389, 5000 Córdoba, Argentina. Email: alorenzo{at}immf.uncor.edu
Deposition of fibrillar amyloid (fA ) plays a critical role in Alzheimer's disease (AD). We have shown recently that fA -induced dystrophy requires the activation of focal adhesion proteins and the formation of aberrant focal adhesion structures, suggesting the activation of a mechanism of maladaptative plasticity in AD. Focal adhesions are actin-based structures that provide a structural link between the extracellular matrix and the cytoskeleton. To gain additional insight in the molecular mechanism of neuronal degeneration in AD, here we explored the involvement of LIM kinase 1 (LIMK1), actin-depolymerizing factor (ADF), and cofilin in A -induced dystrophy. ADF/cofilin are actin-binding proteins that play a central role in actin filament dynamics, and LIMK1 is the kinase that phosphorylates and thereby inhibits ADF/cofilin. Our data indicate that treatment of hippocampal neurons with fA increases the level of Ser3-phosphorylated ADF/cofilin and Thr508-phosphorylated LIMK1 (P-LIMK1), accompanied by a dramatic remodeling of actin filaments, neuritic dystrophy, and neuronal cell death. A synthetic peptide, S3 peptide, which acts as a specific competitor for ADF/cofilin phosphorylation by LIMK1, inhibited fA -induced ADF/cofilin phosphorylation, preventing actin filament remodeling and neuronal degeneration, indicating the involvement of LIMK1 in A -induced neuronal degeneration in vitro. Immunofluorescence analysis of AD brain showed a significant increase in the number of P-LIMK1-positive neurons in areas affected with AD pathology. P-LIMK1-positive neurons also showed early signs of AD pathology, such as intracellular A and pretangle phosphorylated tau. Thus, LIMK1 activation may play a key role in AD pathology.
Key words: amyloid ; A ; LIMK1; ADF/cofilin; Alzheimer's disease; dystrophic neuritis; neuronal neurodegeneration
Received July 21, 2005;
revised April 28, 2006;
accepted April 30, 2006.
Correspondence should be addressed to Dr. Alfredo Lorenzo, Laboratory of Experimental Neuropathology, Instituto de Investigación Médica "Mercedes y Martín Ferreyra"/Consejo Nacional de Investigaciones Científicas y Técnicas, Casilla de Correo 389, 5000 Córdoba, Argentina. Email: alorenzo{at}immf.uncor.edu
This article has been cited by other articles:

|
 |

|
 |
 
Q.-L. Ma, F. Yang, F. Calon, O. J. Ubeda, J. E. Hansen, R. H. Weisbart, W. Beech, S. A. Frautschy, and G. M. Cole
p21-activated Kinase-aberrant Activation and Translocation in Alzheimer Disease Pathogenesis
J. Biol. Chem.,
May 16, 2008;
283(20):
14132 - 14143.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Williamson, A. Usardi, D. P. Hanger, and B. H. Anderton
Membrane-bound {beta}-amyloid oligomers are recruited into lipid rafts by a fyn-dependent mechanism
FASEB J,
May 1, 2008;
22(5):
1552 - 1559.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. Petratos, Q.-X. Li, A. J. George, X. Hou, M. L. Kerr, S. E. Unabia, I. Hatzinisiriou, D. Maksel, M.-I. Aguilar, and D. H. Small
The -amyloid protein of Alzheimer's disease increases neuronal CRMP-2 phosphorylation by a Rho-GTP mechanism
Brain,
January 1, 2008;
131(1):
90 - 108.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Z. Wen, L. Han, J. R. Bamburg, S. Shim, G.-l. Ming, and J. Q. Zheng
BMP gradients steer nerve growth cones by a balancing act of LIM kinase and Slingshot phosphatase on ADF/cofilin
J. Cell Biol.,
October 3, 2007;
178(1):
107 - 119.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. F. S. Bell, D. A. Bennett, and A. C. Cuello
Paradoxical Upregulation of Glutamatergic Presynaptic Boutons during Mild Cognitive Impairment
J. Neurosci.,
October 3, 2007;
27(40):
10810 - 10817.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. M. Sharma, J. M. Litersky, K. Bhaskar, and G. Lee
Tau impacts on growth-factor-stimulated actin remodeling
J. Cell Sci.,
March 1, 2007;
120(5):
748 - 757.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|