RNA-Based Potentiatorsfor AMPA and Kainate Receptors

NIH RePORTER · NIH · R56 · $542,849 · view on reporter.nih.gov ↗

Abstract

AMPA and kainate receptors are different subtypes of the glutamate ion channel family. AMPA receptors mediate the majority of excitatory neurotransmission in the brain, and they are indispensable for brain activities such as memory and learning. Potentiation of AMPA receptors has been shown in both animal and clinical studies to improve cognitive activities such as memory. However, a lack of potent, subtype-selective and subunit-selective potentiators or positive modulators of AMPA receptors has hindered the development of effective drugs for a treatment of age-associated memory impairment and loss. Having subtype-selective potentiators would give us the ability to augment only those AMPA receptor subunits that are involved in memory deficits, but leave those uninvolved untouched. This is because the expression of AMPA receptors and channels in the brain is age-, tissue- and disease-dependent. Therefore, any desirable positive modulators as drug candidates should be highly selective to avoid off-target effects. Our preliminary data have shown we have been able to develop AMPA receptor-selective and separately kainate receptor-selective potentiating aptamers. No known kainate receptor potentiating agent has ever been reported. Thus, the therapeutic utility of a kainate receptor selective potentiator has not yet been explored. The hypothesis to be tested is that the use of a combination of two approaches, i.e., systematic evolution of ligands by exponential enrichment (SELEX) to evolve RNA aptamers from a RNA library, and a set of functional assays, including a laser-pulse photolysis technique to characterize aptamers with the functional (i.e., non-desensitized) receptor forms in the microsecond-to-millisecond time domain, will enable us to identify potent, subtype-selective potentiating RNA aptamers for both AMPA and kainate receptors. The use of the SELEX approach to design and to discover AMPA receptor potentiators represents a paradigm shift from conventional potentiator/drug development strategies. RNA potentiating aptamers themselves represent a new class of positive modulators with a high potential as both tool molecules for neuroscience research and drug candidates for a potential therapy for cognitive impairment in aging.

Key facts

NIH application ID
10231300
Project number
1R56AG066015-01A1
Recipient
STATE UNIVERSITY OF NEW YORK AT ALBANY
Principal Investigator
LI NIU
Activity code
R56
Funding institute
NIH
Fiscal year
2020
Award amount
$542,849
Award type
1
Project period
2020-09-30 → 2023-08-31