scholarly journals Overexpression of Kinesin Superfamily Motor Proteins in Alzheimer’s Disease

2017 ◽  
Vol 60 (4) ◽  
pp. 1511-1524 ◽  
Author(s):  
Kelly Hares ◽  
James Scott Miners ◽  
Amelia Jane Cook ◽  
Claire Rice ◽  
Neil Scolding ◽  
...  
2019 ◽  
Vol 1 ◽  
pp. 1
Author(s):  
Kelly Hares ◽  
Scott Miners ◽  
Neil Scolding ◽  
Seth Love ◽  
Alastair Wilkins

Background: Early disturbances in axonal transport, before the onset of gross neuropathology, occur in a spectrum of neurodegenerative diseases including Alzheimer’s disease. Kinesin superfamily motor proteins (KIFs) are responsible for anterograde protein transport within the axon of various cellular cargoes, including synaptic and structural proteins. Dysregulated KIF expression has been associated with AD pathology and genetic polymorphisms within kinesin-light chain-1 (KLC1) have been linked to AD susceptibility. We examined the expression of KLC1 in AD, in relation to that of the KLC1 motor complex (KIF5A) and to susceptibility genotypes. Methods: We analysed KLC1 and KIF5A gene and protein expression in midfrontal cortex from 47 AD and 39 control brains. Results: We found that gene expression of both KIF5A and KLC1 increased with Braak tangle stage (0-II vs III-IV and V-VI) but was not associated with significant change at the protein level. We found no effect of KLC1 SNPs on KIF5A or KLC1 expression but KIF5A SNPs that had previously been linked to susceptibility in multiple sclerosis were associated with reduced KIF5A mRNA expression in AD cortex. Conclusions: Future in vitro and in vivo studies are required to understand the cause of upregulated KIF5A and KLC-1 gene expression in AD and any potential downstream consequences on pathogenesis, including any contribution of genetic polymorphisms within the KIF5A gene locus.


1998 ◽  
Vol 143 (3) ◽  
pp. 777-794 ◽  
Author(s):  
A. Ebneth ◽  
R. Godemann ◽  
K. Stamer ◽  
S. Illenberger ◽  
B. Trinczek ◽  
...  

The neuronal microtubule-associated protein tau plays an important role in establishing cell polarity by stabilizing axonal microtubules that serve as tracks for motor-protein–driven transport processes. To investigate the role of tau in intracellular transport, we studied the effects of tau expression in stably transfected CHO cells and differentiated neuroblastoma N2a cells. Tau causes a change in cell shape, retards cell growth, and dramatically alters the distribution of various organelles, known to be transported via microtubule-dependent motor proteins. Mitochondria fail to be transported to peripheral cell compartments and cluster in the vicinity of the microtubule-organizing center. The endoplasmic reticulum becomes less dense and no longer extends to the cell periphery. In differentiated N2a cells, the overexpression of tau leads to the disappearance of mitochondria from the neurites. These effects are caused by tau's binding to microtubules and slowing down intracellular transport by preferential impairment of plus-end–directed transport mediated by kinesin-like motor proteins. Since in Alzheimer's disease tau protein is elevated and mislocalized, these observations point to a possible cause for the gradual degeneration of neurons.


2019 ◽  
Vol 1 ◽  
pp. 1
Author(s):  
Kelly Hares ◽  
Scott Miners ◽  
Neil Scolding ◽  
Seth Love ◽  
Alastair Wilkins

Background: Early disturbances in axonal transport, before the onset of gross neuropathology, occur in a spectrum of neurodegenerative diseases including Alzheimer’s disease. Kinesin superfamily motor proteins (KIFs) are responsible for anterograde protein transport within the axon of various cellular cargoes, including synaptic and structural proteins. Dysregulated KIF expression has been associated with AD pathology and genetic polymorphisms within kinesin-light chain-1 (KLC1) have been linked to AD susceptibility. We examined the expression of KLC1 in AD, in relation to that of the KLC1 motor complex (KIF5A) and to susceptibility genotypes. Methods: We analysed KLC1 and KIF5A gene and protein expression in midfrontal cortex from 47 AD and 39 control brains. Results: We found that gene expression of both KIF5A and KLC1 increased with Braak tangle stage (0-II vs III-IV and V-VI) but was not associated with significant change at the protein level. We found no effect of KLC1 SNPs on KIF5A or KLC1 expression but KIF5A SNPs that had previously been linked to susceptibility in multiple sclerosis were associated with reduced KIF5A mRNA expression in AD cortex. Conclusions: The findings raise the possibility that genetic polymorphisms within the KIF5A gene locus could contribute to disturbances of axonal transport, neuronal connectivity and function across a spectrum of neurological conditions, including AD.


2019 ◽  
Vol 42 ◽  
Author(s):  
Colleen M. Kelley ◽  
Larry L. Jacoby

Abstract Cognitive control constrains retrieval processing and so restricts what comes to mind as input to the attribution system. We review evidence that older adults, patients with Alzheimer's disease, and people with traumatic brain injury exert less cognitive control during retrieval, and so are susceptible to memory misattributions in the form of dramatic levels of false remembering.


Author(s):  
J. Metuzals ◽  
D. F. Clapin ◽  
V. Montpetit

Information on the conformation of paired helical filaments (PHF) and the neurofilamentous (NF) network is essential for an understanding of the mechanisms involved in the formation of the primary lesions of Alzheimer's disease (AD): tangles and plaques. The structural and chemical relationships between the NF and the PHF have to be clarified in order to discover the etiological factors of this disease. We are investigating by stereo electron microscopic and biochemical techniques frontal lobe biopsies from patients with AD and squid giant axon preparations. The helical nature of the lesion in AD is related to pathological alterations of basic properties of the nervous system due to the helical symmetry that exists at all hierarchic structural levels in the normal brain. Because of this helical symmetry of NF protein assemblies and PHF, the employment of structure reconstruction techniques to determine the conformation, particularly the handedness of these structures, is most promising. Figs. 1-3 are frontal lobe biopsies.


Author(s):  
Mark Ellisman ◽  
Maryann Martone ◽  
Gabriel Soto ◽  
Eleizer Masliah ◽  
David Hessler ◽  
...  

Structurally-oriented biologists examine cells, tissues, organelles and macromolecules in order to gain insight into cellular and molecular physiology by relating structure to function. The understanding of these structures can be greatly enhanced by the use of techniques for the visualization and quantitative analysis of three-dimensional structure. Three projects from current research activities will be presented in order to illustrate both the present capabilities of computer aided techniques as well as their limitations and future possibilities.The first project concerns the three-dimensional reconstruction of the neuritic plaques found in the brains of patients with Alzheimer's disease. We have developed a software package “Synu” for investigation of 3D data sets which has been used in conjunction with laser confocal light microscopy to study the structure of the neuritic plaque. Tissue sections of autopsy samples from patients with Alzheimer's disease were double-labeled for tau, a cytoskeletal marker for abnormal neurites, and synaptophysin, a marker of presynaptic terminals.


Author(s):  
D.F. Clapin ◽  
V.J.A. Montpetit

Alzheimer's disease is characterized by the accumulation of abnormal filamentous proteins. The most important of these are amyloid fibrils and paired helical filaments (PHF). PHF are located intraneuronally forming bundles called neurofibrillary tangles. The designation of these structures as "tangles" is appropriate at the light microscopic level. However, localized domains within individual tangles appear to demonstrate a regular spacing which may indicate a liquid crystalline phase. The purpose of this paper is to present a statistical geometric analysis of PHF packing.


Author(s):  
V.J.A. Montpetit ◽  
S. Dancea ◽  
S.W. French ◽  
D.F. Clapin

A continuing problem in Alzheimer research is the lack of a suitable animal model for the disease. The absence of neurofibrillary tangles of paired helical filaments is the most critical difference in the processes by which the central nervous system ages in most species other than man. However, restricting consideration to single phenomena, one may identify animal models for specific aspects of Alzheimer's disease. Abnormal fibers resembling PHF have been observed in dorsal root ganglia (DRG) neurons of rats in a study of chronic ethanol intoxication and spontaneously in aged rats. We present in this report evidence that PHF-like filaments occur in ethanol-treated rats of young age. In control animals lesions similar in some respects to our observations of cytoskeletal pathology in pyridoxine induced neurotoxicity were observed.Male Wistar BR rats (Charles River Labs) weighing 350 to 400 g, were implanted with a single gastrostomy cannula and infused with a liquid diet containing 30% of total calories as fat plus ethanol or isocaloric dextrose.


2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.


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