Inward rectifying potassium (Kir) channels are key regulators of diverse physiological processes and may represent novel drug targets for diseases. In most cases, however, the lack of selective pharmacological probes has hindered progress toward defining their specific cellular functions as well as their drugability and therapeutic potential. Here the investigators propose to develop robust primary and secondary assays to support probe development efforts directed toward the """"""""astroglial"""""""" inward rectifier channel Kir4.1. This channel is expressed predominately in glial cells of the nervous system, inner ear and kidney tubule and may be a drug target for glial-cell cancers, disorders of myelination and hypertension.
In Aim 1, the investigators will develop a fluorescence-based thallium (Tl+) flux assay of Kir4.1 channel function for high-throughput screening (HTS) in either 384- or 1536- well plates. The assay will be validated for HTS by performing a screen of approximately 3,000 small molecules for modulators of Kir4.1 activity.
In Aim 2, the investigators will develop additional high- throughput Tl+ flux and moderate-throughput electrophysiological assays to support their subsequent probe development campaign. Lay summary: The long-term objective of this work is to develop novel chemical tools which to probe the structure, function and therapeutic potential of a """"""""potassium channel"""""""" expressed in the nervous system and kidney. These studies may lay the foundation for the development of novel drugs to treat cancer, movement disorders and high blood pressure.

Public Health Relevance

Inward rectifying potassium (Kir) channels play key physiological roles in diverse cell types and may represent novel therapeutic targets. However, the lack of selective small-molecule probes has hindered efforts to understand the integrative physiology and pharmacology of most Kir channels. Here we propose to develop robust fluorescence and electrophysiological assays to support high-throughput screening (HTS) and probe development efforts directed toward the """"""""astroglial"""""""" potassium channel Kir4.1.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21NS073097-01
Application #
8051173
Study Section
Special Emphasis Panel (ZRG1-BST-J (51))
Program Officer
Scheideler, Mark A
Project Start
2010-09-27
Project End
2014-08-31
Budget Start
2010-09-27
Budget End
2014-08-31
Support Year
1
Fiscal Year
2010
Total Cost
$155,167
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Anesthesiology
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
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Swale, Daniel R; Kharade, Sujay V; Denton, Jerod S (2014) Cardiac and renal inward rectifier potassium channel pharmacology: emerging tools for integrative physiology and therapeutics. Curr Opin Pharmacol 15:7-15
Raphemot, Rene; Weaver, C David; Denton, Jerod S (2013) High-throughput screening for small-molecule modulators of inward rectifier potassium channels. J Vis Exp :
Raphemot, Rene; Kadakia, Rishin J; Olsen, Michelle L et al. (2013) Development and validation of fluorescence-based and automated patch clamp-based functional assays for the inward rectifier potassium channel Kir4.1. Assay Drug Dev Technol 11:532-43
Denton, Jerod S; Pao, Alan C; Maduke, Merritt (2013) Novel diuretic targets. Am J Physiol Renal Physiol 305:F931-42