Current Alzheimer Research

Debomoy K. Lahiri  
Department of Psychiatry, Indiana University School of Medicine
Neuroscience Research Center
Indianapolis, IN 46202
USA

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ADF/Cofilin-Actin Rods in Neurodegenerative Diseases

Author(s): J.R. Bamburg, B.W. Bernstein, R.C Davis, K.C. Flynn, C. Goldsbury, J.R. Jensen, M.T. Maloney, I.T. Marsden, L.S. Minamide, C.W. Pak, A.E. Shaw, I. Whiteman and O. Wiggan

Affiliation: Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA.

Abstract:

Dephosphorylation (activation) of cofilin, an actin binding protein, is stimulated by initiators of neuronal dysfunction and degeneration including oxidative stress, excitotoxic glutamate, ischemia, and soluble forms of β-amyloid peptide (Aβ). Hyperactive cofilin forms rod-shaped cofilin-saturated actin filament bundles (rods). Other proteins are recruited to rods but are not necessary for rod formation. Neuronal cytoplasmic rods accumulate within neurites where they disrupt synaptic function and are a likely cause of synaptic loss without neuronal loss, as occurs early in dementias. Different rod-inducing stimuli target distinct neuronal populations within the hippocampus. Rods form rapidly, often in tandem arrays, in response to stress. They accumulate phosphorylated tau that immunostains for epitopes present in “striated neuropil threads,” characteristic of tau pathology in Alzheimer disease (AD) brain. Thus, rods might aid in further tau modifications or assembly into paired helical filaments, the major component of neurofibrillary tangles (NFTs). Rods can occlude neurites and block vesicle transport. Some rod-inducing treatments cause an increase in secreted Aβ. Thus rods may mediate the loss of synapses, production of excess Aβ, and formation of NFTs, all of the pathological hallmarks of AD. Cofilin-actin rods also form within the nucleus of heat-shocked neurons and are cleared from cells expressing wild type huntingtin protein but not in cells expressing mutant or silenced huntingtin, suggesting a role for nuclear rods in Huntington disease (HD). As an early event in the neurodegenerative cascade, rod formation is an ideal target for therapeutic intervention that might be useful in treatment of many different neurological diseases.

Keywords: Cytoskeleton, Alzheimer disease, hippocampus, vesicle transport, amyloid beta, oxidative stress, Huntington disease, peptidomimetics, phosphorylated tau

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Article Details

VOLUME: 7
ISSUE: 3
Page: [241 - 250]
Pages: 10
DOI: 10.2174/156720510791050902
Price: $58