# Modification of HDL and Macrophage Function in Atherosclerosis

> **NIH NIH P01** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2022 · $364,834

## Abstract

A major factor in mortality from atherosclerotic cardiovascular disease is the formation and expansion of
necrotic cores within lesions, which arise when macrophages that normally carry out efferocytosis
(phagocytosis of apoptotic cells) fail to clear apoptotic cells and instead undergo secondary necrosis. This
project seeks to elucidate the contribution of two families of lipids, isolevuglandins (IsoLG) and N-
acylethanolamides (NAEs), that potentially interact through HDL to altered macrophage efferocytic function, as
well as the role of Nape-pld, an enzyme that catalyzes both the formation of NAEs and the degradation of the
IsoLG adducts. We hypothesize that under normal conditions HDL promotes the ability of macrophages to
carry out efferocytosis by 1) accepting the cholesterol that macrophages take up during phagocytosis of
apoptotic cells and 2) delivering NAE precursors to macrophages which use their Nape-pld to hydrolyze these
precursors to NAEs which can promote expression of genes needed for efferocytosis. We hypothesize that in
conditions that promote atherosclerosis, HDL becomes modified by IsoLG which retards efferocytosis by 1)
inhibiting HDL's ability to accept cholesterol and 2) creating ligands recognized by pattern recognition
receptors that drive macrophages to a pro-inflammatory phenotype with high expression of inflammatory
cytokines and low expression of proteins needed for efferocytosis. Thus, IsoLG modification of HDL and
reduced Nape-pld expression combine to suppress the efferocytic capacity of macrophages, leading to the
formation and expansion of necrotic cores which create vulnerable atherosclerotic plaques.
We will test this hypothesis as follows:
Aim 1 will determine if apoAI lysine residues critical to cholesterol efflux are modified by isolevuglandins during
development of atherosclerosis.
Aim 2 will elucidate the mechanisms whereby HDL modified by lipid dicarbonyls potentiate inflammation in
macrophages and determine if these alterations contribute to reduced efferocytosis.
Aim 3 will determine the effects of macrophage Nape-pld deletion on atherosclerosis and macrophage
efferocytic capacity.

## Key facts

- **NIH application ID:** 10327718
- **Project number:** 5P01HL116263-07
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** SEAN Stephen DAVIES
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $364,834
- **Award type:** 5
- **Project period:** 2014-06-01 → 2025-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10327718

## Citation

> US National Institutes of Health, RePORTER application 10327718, Modification of HDL and Macrophage Function in Atherosclerosis (5P01HL116263-07). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10327718. Licensed CC0.

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