HIV-associated neurocognitive disorder is clinically defined by a combination of motor, cognitive, and behavioral deficits that result from progressive neuronal damage. Although a constellation of factors contributes to the neurodegeneration that occurs in HAND, the precise mechanism leading to neuronal damage remains unelucidated. Interestingly, the cell cycle machinery, specifically E2F1, has been implicated in many neurodegenerative diseases including HAND. However, both the physiologic and the pathologic roles of this cell cycle-related protein remain poorly understood. Ultimately, this new knowledge will lead to a novel therapeutic strategy of targeting the preservation of E2F1 physiologic function while simultaneously blocking its pathologic activity for treating HAND and other neurodegenerative diseases. The preliminary data provided in this proposal suggests that E2F1 binds RNA and plays a role in synaptic specialization, thus leading to the specific hypothesis of which E2F1 regulates synaptic specialization through its RNA binding activity in postmitotic neurons. To determine the role of E2F1 in synaptic specialization, E2F1 will be depleted using RNA interference technology or genetic knockout animals and assay for changes in dendritic arborization, spine morphogenesis, PSD95 clustering, and synapse number. To determine the role of E2F1 RNA binding activity in neurons, the RNA binding activity will be inhibited with dominant negative constructs lacking RNA binding domain or containing RNA competitive ligand and assay for changes in neuronal viability, stability of target ligands, and synaptic specializations. The results from these experiments will identify the physiologic role of E2F1 in postmitotic neurons and its potential pathologic contributions in HAND.

Public Health Relevance

Patients with HIV-associated dementia exhibit increased expression of cell cycle-related protein E2F1. However, little is known about its physiologic role in neurons and its pathologic role in neurodegeneration. We believe that identifying its physiologic function in neurons will lead to novel therapeutic strategy of targeting E2F1 to prevent neuronal damage and subsequent cognitive decline in HIV-associated dementia.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31NS071787-02
Application #
8153154
Study Section
Special Emphasis Panel (ZRG1-AARR-H (22))
Program Officer
Wong, May
Project Start
2010-07-01
Project End
2013-06-30
Budget Start
2011-07-01
Budget End
2012-06-30
Support Year
2
Fiscal Year
2011
Total Cost
$41,800
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Jackson, Dan P; Ting, Jenhao H; Pozniak, Paul D et al. (2018) Identification and characterization of two novel alternatively spliced E2F1 transcripts in the rat CNS. Mol Cell Neurosci 92:1-11
Zyskind, Jacob W; Wang, Ying; Cho, Giyong et al. (2015) E2F1 in neurons is cleaved by calpain in an NMDA receptor-dependent manner in a model of HIV-induced neurotoxicity. J Neurochem 132:742-55
Ting, Jenhao H; Marks, David R; Schleidt, Stephanie S et al. (2014) Targeted gene mutation of E2F1 evokes age-dependent synaptic disruption and behavioral deficits. J Neurochem 129:850-63
Wang, Ying; Zyskind, Jacob W; Colacurcio, Daniel J et al. (2012) Differential roles for caspase-mediated and calpain-mediated cell death in 1- and 3-week-old rat cortical cultures. Neuroreport 23:1052-8