# Leukotriene B4 Regulation in Heart

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2024 · $643,426

## Abstract

PROJECT ABSTRACT
 Patients with type 2 diabetes (T2DM) are at increased risk (~50%) relative to non-diabetic individuals
of suffering sudden cardiac death (SCD), most often due to fatal ventricular arrhythmias such as torsades de
pointes (TdP). However, the underlying molecular mechanisms are unknown. Therefore, there is the critical
need to identify and validate novel cellular proarrhythmic mechanisms in T2DM. In that regard, we have
identified and validated a proarrhythmic lipid mediator, leukotriene B4 (LTB4), that is elevated in diabetes
compared to non-diabetic patients suggesting that risk for ventricular arrhythmias may be highest for patients
with high levels of LTB4. LTB4 inhibitors are a class of FDA-approved drugs that have been shown to confer
major cardiovascular benefits. Recent evidence showed that LTB4 receptor (LTB4R) knockout or LTB4
inhibitor treatment of myocytes, prevented LTB4-related metabolic defects, supporting the results of a
separate report indicating reduced LTB4 biosynthesis prevented ischemia/reperfusion-induced arrhythmias.
Our pilot studies revealed that LTB4 is increased in multiple diabetes mouse models (ob/ob and PANIC-
ATTAC), induces a profound prolongation of ventricular action potential duration, triggers cellular
arrhythmogenesis, and severely depresses the repolarizing rapidly activating delayed rectifier K current (IKr)
density in guinea pig ventricular myocytes but not in healthy heart cells, consistent with TdP vulnerability. We
have further found that guinea pigs challenged with LTB4 displayed prolonged QT interval, and that this can
be prevented with LTB4R inhibition, suggesting that preventing such LTB4-LTB4R effects may be
therapeutically beneficial in T2DM ventricular arrhythmias. Our long-term goal is to accelerate the rational
development of clinically useful anti-LTB4 agents as treatments for malignant ventricular arrhythmias. The
overall objective for this application is to determine how the LTB4R signaling axis promotes arrhythmia and its
usefulness as a preclinical drug target. Our central hypothesis, based on preliminary data described above, is
that LTB4 through the LTB4R drives adverse remodeling of ventricular myocyte electrical activity and
propensity for ventricular arrhythmias by promoting impaired IKr biophysics and preventing its functional
expression. The rationale for the proposed research is that a science-based determination of the preclinical in
vitro proarrhythmic effects of LTB4 and associated mechanisms of LTB4R inhibition is likely to support the
development of new and promising therapeutic strategies in patients with T2DM. Our experimental studies
will combine optical (FRET, photo-switchable fluorescent proteins, quantum dot labeling, 3D reconstruction),
electrophysiology, genetic and pharmacological tools in guinea pig and human ventricular myocytes. Our
expectation is that, if we understand T2DM ventricular electrical remodeling from a perspective of LTB4 and
downstream ...

## Key facts

- **NIH application ID:** 10936974
- **Project number:** 1R01HL174450-01
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Ademuyiwa Aromolaran
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $643,426
- **Award type:** 1
- **Project period:** 2024-07-01 → 2029-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10936974

## Citation

> US National Institutes of Health, RePORTER application 10936974, Leukotriene B4 Regulation in Heart (1R01HL174450-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10936974. Licensed CC0.

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