- Email: [email protected]
THE ROLE OF MICROTUBULES IN EXCITOTOXIN-INDUCED AXON DEGENERATION
Poster Presentations: Tuesday, July 18, 2017
after 6 months of chronic oral administration. Molecular mechanisms of neuroportection intersect with the longevity pathways activated by caloric restriction. Conclusions: Our studies demonstrate that modulation of MCI activity by small molecules partial inhibitors represents novel, safe and efficacious strategy for AD.
P3-060
P953
INTEGRATED BIOINFORMATICS ANALYSIS OF DIFFERENTIALLY EXPRESSED GENES (DEGS) OF ALZHEIMER’S DISEASE (AD) DATASETS FROM GENE EXPRESSION OMNIBUS (GEO)
Ashwani Kumar, Ankush Bansal, Jaypee University of Information Technology, Shimla, India. Contact e-mail: [email protected] P3-058
THE ROLE OF MICROTUBULES IN EXCITOTOXIN-INDUCED AXON DEGENERATION
Kelsey Hanson1, Carmen Fernandez-Martos1, James C. Vickers2, Anna E. King11Wicking Dementia Research and Education Centre, Hobart, Australia; 2University of Tasmania, Hobart, Australia. Contact e-mail: [email protected] Background: Axon degeneration is a process which occurs in
several neurodegenerative diseases, including Alzheimer’s disease, although, mechanisms are not well characterized. One potential cause of axon degeneration, excitotoxicity, results in the breakdown of the microtubule cytoskeleton, by unknown mechanisms. Investigating microtubule alterations following excitotoxic insult could provide insight into potential therapeutic treatment with microtubule stabilizing drugs. Therefore, we examined a time course of microtubule modifications after kainic acid-induced excitotoxicity and the potential of stabilizing microtubules with trichostatin A to prevent axon degeneration in vitro. Methods: Primary cortical culture of embryonic day 15.5 C57Bl/6 mice were grown to 10 days in vitro (DIV) prior to treatment with 10mM and 25mM concentrations of kainic acid to induce excitotoxicity. Alterations to microtubules, including post-translational modifications acetylation, tyrosination and glutamylation as well as alterations to microtubule associated proteins were assessed at 1, 6 and 18 hours post-treatment using ELISA and immunocytochemical techniques. Cell viability was assessed using alamarBlueÒ after kainic acid and trichostatin A treatment. Results: Kainic acid-induced excitotoxicity significantly (p<0.05) reduced acetylation of microtubules but significantly (p<0.05) increased tau expression after 6 hours. However, tyrosination of microtubules was unchanged. Cell viability assessed using alamarBlueÒ was reduced after kainic acid treatment. Microtubule stabilizing agent trichostatin A, increased acetylation of microtubules after 2 hours and was not toxic to neurons. Furthermore, when neurons were pre-treated with the drug prior to kainic acid exposure axon fragmentation was significantly (p<0.05) reduced. Conclusions: These data suggest that excitotoxic insult reduces microtubule acetylation and targeting microtubule post-translational modifications may be a promising potential therapeutic target for axon protection. Tyrosination was unaffected by excitotoxic insult at 10mM and 25mM kainic acid, suggesting it does not play a role in microtubule breakdown.
P3-059
WITHDRAWN
Background: Genome-wide transcription profiling is a powerful
diagnostic technique applied to disease tissue that may reveal quantitative and qualitative alterations in gene expression, that give information about genetics of disease. However, the data obtained from high-density microarrays and their mining is highly complex. Methods: In this paper, analysis of Hippocampal gene expression of 9 control and 22 Alzheimer’s Disease (AD) subjects of varying severity on 31 separate microarrays has been performed. We have applied two tailed T-test at significance level of 0.01 and grouped samples according to expression value of genes and then ranked accordingly for genes of different stage of AD. The important parameter for observing gene expression changes are P-value and log fold change in gene expression values. Cluster Heat maps are generated according to hierarchical gene mapping by using uncentered correlation distance and complete linkage algorithm. Results: It has been observed that for the over expression data there was frequent occurrence of major histocompatibility complex I and II related genes and few kinases, enolaeses and esterases, while for the under expression data abundance of kinases and few transcription factors was found. These biological entities were further analyzed for their specific role in the neuronal functions and transmissions. Conclusions: From these studies we can attempt to define therapeutic strategies that would prevent the loss of specific components of neuronal function in susceptible patients or be in a position to stimulate the replacement of lost cellular function in damaged neurons.
P3-061
POSTMORTEM BIOCHEMICAL ASSESSMENT OF SEVERITY AND MECHANISMS OF NEURORADIOLOGICALLY DOCUMENTED WHITE MATTER INJURY IN SMALL-VESSEL DISEASE
Catherine Humphreys1, Scott Miners2, Joanna M. Wardlaw3, Colin Smith4, Seth Love2, 1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom; 2University of Bristol, Bristol, United Kingdom; 3University of Edinburgh, Edinburgh, United Kingdom; 4 Univeristy of Edinburgh, Edinburgh, United Kingdom. Contact e-mail: [email protected] Background: Several neuroimaging abnormalities of cerebral white matter have been attributed to arteriolosclerotic small vessel disease, implicated in many cases of dementia. The pathogenesis of these abnormalities is poorly understood. Biochemical methods have been developed for measuring specific vessel wall constituents, proteins altered by tissue hypoxia, and others extravasated through leaky vessels, all
after 6 months of chronic oral administration. Molecular mechanisms of neuroportection intersect with the longevity pathways activated by caloric restriction. Conclusions: Our studies demonstrate that modulation of MCI activity by small molecules partial inhibitors represents novel, safe and efficacious strategy for AD.
P3-060
P953
INTEGRATED BIOINFORMATICS ANALYSIS OF DIFFERENTIALLY EXPRESSED GENES (DEGS) OF ALZHEIMER’S DISEASE (AD) DATASETS FROM GENE EXPRESSION OMNIBUS (GEO)
Ashwani Kumar, Ankush Bansal, Jaypee University of Information Technology, Shimla, India. Contact e-mail: [email protected] P3-058
THE ROLE OF MICROTUBULES IN EXCITOTOXIN-INDUCED AXON DEGENERATION
Kelsey Hanson1, Carmen Fernandez-Martos1, James C. Vickers2, Anna E. King11Wicking Dementia Research and Education Centre, Hobart, Australia; 2University of Tasmania, Hobart, Australia. Contact e-mail: [email protected] Background: Axon degeneration is a process which occurs in
several neurodegenerative diseases, including Alzheimer’s disease, although, mechanisms are not well characterized. One potential cause of axon degeneration, excitotoxicity, results in the breakdown of the microtubule cytoskeleton, by unknown mechanisms. Investigating microtubule alterations following excitotoxic insult could provide insight into potential therapeutic treatment with microtubule stabilizing drugs. Therefore, we examined a time course of microtubule modifications after kainic acid-induced excitotoxicity and the potential of stabilizing microtubules with trichostatin A to prevent axon degeneration in vitro. Methods: Primary cortical culture of embryonic day 15.5 C57Bl/6 mice were grown to 10 days in vitro (DIV) prior to treatment with 10mM and 25mM concentrations of kainic acid to induce excitotoxicity. Alterations to microtubules, including post-translational modifications acetylation, tyrosination and glutamylation as well as alterations to microtubule associated proteins were assessed at 1, 6 and 18 hours post-treatment using ELISA and immunocytochemical techniques. Cell viability was assessed using alamarBlueÒ after kainic acid and trichostatin A treatment. Results: Kainic acid-induced excitotoxicity significantly (p<0.05) reduced acetylation of microtubules but significantly (p<0.05) increased tau expression after 6 hours. However, tyrosination of microtubules was unchanged. Cell viability assessed using alamarBlueÒ was reduced after kainic acid treatment. Microtubule stabilizing agent trichostatin A, increased acetylation of microtubules after 2 hours and was not toxic to neurons. Furthermore, when neurons were pre-treated with the drug prior to kainic acid exposure axon fragmentation was significantly (p<0.05) reduced. Conclusions: These data suggest that excitotoxic insult reduces microtubule acetylation and targeting microtubule post-translational modifications may be a promising potential therapeutic target for axon protection. Tyrosination was unaffected by excitotoxic insult at 10mM and 25mM kainic acid, suggesting it does not play a role in microtubule breakdown.
P3-059
WITHDRAWN
Background: Genome-wide transcription profiling is a powerful
diagnostic technique applied to disease tissue that may reveal quantitative and qualitative alterations in gene expression, that give information about genetics of disease. However, the data obtained from high-density microarrays and their mining is highly complex. Methods: In this paper, analysis of Hippocampal gene expression of 9 control and 22 Alzheimer’s Disease (AD) subjects of varying severity on 31 separate microarrays has been performed. We have applied two tailed T-test at significance level of 0.01 and grouped samples according to expression value of genes and then ranked accordingly for genes of different stage of AD. The important parameter for observing gene expression changes are P-value and log fold change in gene expression values. Cluster Heat maps are generated according to hierarchical gene mapping by using uncentered correlation distance and complete linkage algorithm. Results: It has been observed that for the over expression data there was frequent occurrence of major histocompatibility complex I and II related genes and few kinases, enolaeses and esterases, while for the under expression data abundance of kinases and few transcription factors was found. These biological entities were further analyzed for their specific role in the neuronal functions and transmissions. Conclusions: From these studies we can attempt to define therapeutic strategies that would prevent the loss of specific components of neuronal function in susceptible patients or be in a position to stimulate the replacement of lost cellular function in damaged neurons.
P3-061
POSTMORTEM BIOCHEMICAL ASSESSMENT OF SEVERITY AND MECHANISMS OF NEURORADIOLOGICALLY DOCUMENTED WHITE MATTER INJURY IN SMALL-VESSEL DISEASE
Catherine Humphreys1, Scott Miners2, Joanna M. Wardlaw3, Colin Smith4, Seth Love2, 1Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom; 2University of Bristol, Bristol, United Kingdom; 3University of Edinburgh, Edinburgh, United Kingdom; 4 Univeristy of Edinburgh, Edinburgh, United Kingdom. Contact e-mail: [email protected] Background: Several neuroimaging abnormalities of cerebral white matter have been attributed to arteriolosclerotic small vessel disease, implicated in many cases of dementia. The pathogenesis of these abnormalities is poorly understood. Biochemical methods have been developed for measuring specific vessel wall constituents, proteins altered by tissue hypoxia, and others extravasated through leaky vessels, all