# Discovery of Adenosine Receptor Allosteric Modulators for Cardiovascular Disease and Inflammation

> **NIH NIH F31** · MEDICAL COLLEGE OF WISCONSIN · 2022 · $39,528

## Abstract

PROJECT SUMMARY
Cardiovascular disease is the leading cause of death in the United States for both men and women, costing
$351.2 billion dollars and accounting for over 840,000 deaths annually. The A3 adenosine receptor (A3AR) is a
Gi protein-coupled receptor that is highly expressed in several types of inflammatory cells, including neutrophils.
Increased adenosine levels following tissue injury/inflammation leads to activation of A3AR signaling, which aids
to limit inflammation and to promote repair, in part by impairing immune cell chemotaxis and activation. Agonists
of the A3AR are being investigated for a multitude of inflammatory diseases including cardiac ischemia and
chemotherapy-induced cardiotoxicity. Unfortunately, dose-limiting side effects have been reported in early
clinical trials potentially limiting their usefulness. Compounds that potentiate signaling of endogenous ligands,
termed positive allosteric modulators (PAMs), allow for spatiotemporal specificity, and reduced off-target effects.
It is anticipated that PAMs targeting the A3AR will offer a superior treatment approach. In these proposed studies,
I aim to characterize and further develop A3AR PAMs that will serve as small molecule probes and useful therapeutics for
cardiac injury and inflammatory disorders. Prior structure-activity-relationship studies (SAR) identified the 1H-
imidazo[4,5]quinoline-4-amine, LUF6000, and the 2,4-disubstituted quinoline, LUF6096, as exhibiting PAM
activity at the A3AR, where these modulators enhance orthosteric agonist efficacy upwards of 2-fold.
Unfortunately, they also have the undesirable tendency to decrease agonist potency. In addition, none of the
PAMs we have investigated thus far exhibit PAM activity versus rodent receptors, preventing us from assessing
biological activity in preclinical rodent models of disease. In Aim 1, I will expand on prior SAR studies by
characterizing two new series of derivatives, based off the structures of LUF6000 and LUF6096 with the goal of
identifying improved A3AR PAMs that dually enhance orthosteric agonist efficacy and potency. As part of this
aim, I will investigate whether our PAM ligands support biased (G protein-dependent vs G protein-independent)
signaling and assess for activity versus the mouse A3AR. In Aim 2, I will exploit species differences and generate
human/mouse chimeric and mutant A3ARs to facilitate identification of the binding pocket for LUF6000 and
LUF6096. Lastly, in Aim 3 I will investigate the biological effects of LUF6000 and LUF6096 on two critical
neutrophil functions - superoxide production and chemotaxis - utilizing a human neutrophilic cell line (HL60 cells).
Upon completion of these proposed studies, under the guidance of my mentor, a diverse team of collaborators,
and my dissertation committee, I will gain experience in experimental design, execution of biochemical assays,
molecular cloning, and basics of rational drug design, which will result in publishable data and prepa...

## Key facts

- **NIH application ID:** 10464473
- **Project number:** 1F31HL160193-01A1
- **Recipient organization:** MEDICAL COLLEGE OF WISCONSIN
- **Principal Investigator:** Courtney L Fisher
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $39,528
- **Award type:** 1
- **Project period:** 2022-09-02 → 2023-06-14

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10464473

## Citation

> US National Institutes of Health, RePORTER application 10464473, Discovery of Adenosine Receptor Allosteric Modulators for Cardiovascular Disease and Inflammation (1F31HL160193-01A1). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10464473. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*