The experiments in this project use innovative gene delivery techniques and a multipronged approach to assess the fundamental role of astrocyte activation in neurologic function in an intact mouse model of Alzheimer's disease (AD). Studies use adeno-associated virus vectors (AAV) bearing the astrocyte-specific promoter Gfa2 to target the protein phosphatase calcineurin (CN) and NFAT transcription factors in astrocytes of wild-type and APP/PS1 mice. AAV-Gfa2 vectors are bilaterally delivered to the hippocampus at different ages/disease stages and mice are assessed on different AD biomarkers.
In Aim 1, cognitive status is assessed using the active avoidance task, while synaptic function is evaluated using hippocampal slice electrophysiology and Western blot measures of synaptic proteins.
In Aim 2, hippocampal glutamate regulation is investigated using ceramic enzyme-based microelectrode arrays and measures of glutamate transporter levels.
In Aim 3, levels of glial activation and neuroinflammation are determined with immunohistochemical (IHC) analyses and assessment of cytokine levels using Multiplex ELISAs.
In Aim 4, IHC is used to determine the extent of A? deposition, while ELISAs are used to quantify levels of A?40 and A?42 in soluble and insoluble hippocampal tissue fractions, and Westerns used to assess BACE protein expression. AAV-Gfa2 vectors encode either potent inhibitors or activators of CN/NFAT signaling and therefore will determine the necessity and sufficiency of this astrocytic pathway in driving and/or maintaining neurologic dysfunction in AD mice. These studies provide a highly novel approach to the study of activated astrocytes and could have a major impact on the development of treatment strategies for AD and other neurodegenerative conditions.

Public Health Relevance

Increasing evidence implicates activated astrocytes in a variety of neurodegenerative conditions, including Alzheimer's disease (AD). However, these cells are difficult to target selectively with therapeutics. In this project, we use cutting-edge adeno associated virus vectors to selectively prevent astrocyte activation and improve neurologic function in intact AD model mice. This approach could emerge as a new treatment strategy for AD and other neurodegenerative disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG027297-08
Application #
8657965
Study Section
Cell Death in Neurodegeneration Study Section (CDIN)
Program Officer
Wise, Bradley C
Project Start
2005-12-01
Project End
2017-03-31
Budget Start
2014-04-01
Budget End
2015-03-31
Support Year
8
Fiscal Year
2014
Total Cost
$299,613
Indirect Cost
$94,613
Name
University of Kentucky
Department
Other Health Professions
Type
Schools of Medicine
DUNS #
939017877
City
Lexington
State
KY
Country
United States
Zip Code
40506
Sompol, Pradoldej; Furman, Jennifer L; Pleiss, Melanie M et al. (2017) Calcineurin/NFAT Signaling in Activated Astrocytes Drives Network Hyperexcitability in A?-Bearing Mice. J Neurosci 37:6132-6148
Sudduth, Tiffany L; Weekman, Erica M; Price, Brittani R et al. (2017) Time-course of glial changes in the hyperhomocysteinemia model of vascular cognitive impairment and dementia (VCID). Neuroscience 341:42-51
Lovell, Mark A; Lynn, Bert C; Fister, Shuling et al. (2016) A Novel Small Molecule Modulator of Amyloid Pathology. J Alzheimers Dis 53:273-87
Pleiss, Melanie M; Sompol, Pradoldej; Kraner, Susan D et al. (2016) Calcineurin proteolysis in astrocytes: Implications for impaired synaptic function. Biochim Biophys Acta 1862:1521-32
Pettigrew, L Creed; Kryscio, Richard J; Norris, Christopher M (2016) The TNF?-Transgenic Rat: Hippocampal Synaptic Integrity, Cognition, Function, and Post-Ischemic Cell Loss. PLoS One 11:e0154721
Norris, Christopher M; Sompol, Pradoldej; Roberts, Kelly N et al. (2016) Pycnogenol protects CA3-CA1 synaptic function in a rat model of traumatic brain injury. Exp Neurol 276:5-12
Furman, Jennifer L; Sompol, Pradoldej; Kraner, Susan D et al. (2016) Blockade of Astrocytic Calcineurin/NFAT Signaling Helps to Normalize Hippocampal Synaptic Function and Plasticity in a Rat Model of Traumatic Brain Injury. J Neurosci 36:1502-15
Niedowicz, Dana M; Reeves, Valerie L; Platt, Thomas L et al. (2014) Obesity and diabetes cause cognitive dysfunction in the absence of accelerated ?-amyloid deposition in a novel murine model of mixed or vascular dementia. Acta Neuropathol Commun 2:64
Wang, Wang-Xia; Danaher, Robert J; Miller, Craig S et al. (2014) Expression of miR-15/107 family microRNAs in human tissues and cultured rat brain cells. Genomics Proteomics Bioinformatics 12:19-30
Furman, Jennifer L; Norris, Christopher M (2014) Calcineurin and glial signaling: neuroinflammation and beyond. J Neuroinflammation 11:158

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