Gap junction-mediated intercellular ionic and metabolic coupling provides both homeostatic and signaling functions among astrocytes throughout the brain, and CNS pathology both results in and is caused by disruptions in astrocyte gap junction signaling. It is now well known that gap junction proteins (connexins) interact with other proteins, forming a molecular complex we term the Nexus. Recent data indicate that Nexus is a highly dynamic signaling unit, where direct linkages of connexins to adaptor and scaffolding molecules are bound to cytoskeletal, cytoplasmic and other membrane proteins, polarizing the astrocyte. The overall goal of this grant proposal is to understand how gap junctions in astrocytes control organization of this endfoot complex and thus control blood-brain-barrier integrity. To accomplish this goal, we propose to:
Aim 1 : Test the hypothesis that localization and mobility of gap junction proteins and their binding partners determines organization of astrocyte endfeet.
Aim 2. Determine downstream effects of connexins on endothelial tight junction formation.
Aim 3. Validate the hypothesis that localization and mobility of gap junction proteins and their binding partners determines organization of astrocyte endfeet using mice with modified connexin expression We believe that these interdisciplinary and innovative studies will provide the first molecular insights into the role of the astrocyte Nexus i establishment of cell polarity and thus identify important astrocyte functions that can be targeted to reverse disorders of astrocyte polarity.

Public Health Relevance

This application, which is based on numerous previous findings by the applicants, will determine how the protein complex formed of gap junction proteins and their binding partners contribute to astrocyte physiology. Specific experiments will evaluate how connexins link to cytoskeletal and other proteins of astrocytes, how these interactions give rise to polarization of astrocytes and to establishment of the tight endothelial barrier and how both the astrocyte polarization and endothelial barrier are remodeled following disruption by ultrasound.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS092466-07
Application #
9752670
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Bosetti, Francesca
Project Start
2015-09-01
Project End
2020-07-31
Budget Start
2019-08-01
Budget End
2020-07-31
Support Year
7
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Albert Einstein College of Medicine
Department
Type
DUNS #
081266487
City
Bronx
State
NY
Country
United States
Zip Code
10461
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