N-aldehyde modified phosphatidylethanolamines formed by lipid peroxidation inhibit efferocytosis.
- 1Vanderbilt University
Abstract
Objective: Impairments in efferocytosis, the phagocytic clearance of apoptotic cells, contribute to the development of chronic inflammation and promote the formation of large necrotic cores within atherosclerotic plaques. A better understanding of the factors that impair efferocytosis could lead to improved interventions. Many chronic inflammatory conditions feature excessive lipid peroxidation, which generates reactive lipid aldehydes that can potentially form N-aldehyde-modified phosphatidylethanolamines (NAMPs). We therefore investigated the extent to which levels of NAMPs are elevated under conditions of oxidative stress and whether exposure of macrophages to NAMPs inhibit efferocytosis. Approach and Results: The effects of synthetic NAMPs and lipid peroxidation on efferocytosis were measured using the Incucyte Live-Cell Analysis System to monitor rate of ingestion of CypHer-labeled apoptotic cells by cultured bone marrow-derived macrophages in real time. The extent of NAMP formation under various conditions was examined using liquid chromatography coupled with mass spectrometry. Several representative species of NAMPs (N-isolevuglandin-phosphatidylethanolamine, N-IsoLG-PE; N-4-hydroxynonenal-phosphatidylethanolamine, N-HNE-PE; and N-azeloyl-phosphatidylethanolamine, N-Aze-PE) inhibited efferocytosis in a concentration-dependent manner. Hydrolysis of NAMPs by recombinant N-acyl phosphatidylethanolamine hydrolyzing phospholipase D (NAPE-PLD) abolished their inhibitory activity, whereas genetic deletion of macrophage NAPE-PLD enhanced NAMP-mediated inhibition of efferocytosis. Blocking the inhibitor of lipid peroxidation, glutathione peroxidase 4 (GPX4), increased macrophage NAMP concentrations and impaired efferocytosis. Unmodified high-density lipoprotein (HDL) promoted efferocytosis, but exposing HDL to reactive lipid aldehydes or peroxidizing agents markedly increased NAMPs and this modified HDL inhibited efferocytosis. HDL isolated from subjects with familial hypercholesterolemia had elevated levels of multiple NAMP species. NAMPs impaired macrophage cholesterol efflux, which is required for continual efferocytosis. Conclusion: NAMPs accumulate under conditions associated with lipid peroxidation and inhibit the ability of macrophages to carry out efferocytosis.
Related
- Insect-specific aldehyde synthase governs cuticle strength: a selective insecticide target
- CD300a Blockade attenuates renal fibrosis by enhancing macrophage efferocytosis and neutrophil MMP9 production
- Transient efferocytosis-induced activation of IKKβ reprograms macrophages to promote tissue resolution in mice
- Lipid peroxidation in Spartina alterniflora in relation to anthropogenic particles (APs) and sediment conditions in the Bahía Blanca Estuary, Argentina
- Elevated procoagulant platelets driven by necroptosis and pyroptosis aggravate pulmonary thrombosis via suppressing monocyte efferocytosis in severe pneumonia
BibTeX
@misc{fadaei2026naldehyde,
title = {{N-aldehyde modified phosphatidylethanolamines formed by lipid peroxidation inhibit efferocytosis.}},
author = {R. Fadaei and A. C. Bernstein and E. A. Wayman and A. L. Gonzalez and K. A. Tallman and Z. Mashhadi and A.-m. Alli-oluwafuyi and S. I. Dikalov and M. F. Linton and K. C. Vickers and A. C. Doran and S. S. Davies},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.10.750792},
url = {https://www.biorxiv.org/content/10.64898/2026.09.10.750792v1},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - N-aldehyde modified phosphatidylethanolamines formed by lipid peroxidation inhibit efferocytosis.
AU - R. Fadaei
AU - A. C. Bernstein
AU - E. A. Wayman
AU - A. L. Gonzalez
AU - K. A. Tallman
AU - Z. Mashhadi
AU - A.-m. Alli-oluwafuyi
AU - S. I. Dikalov
AU - M. F. Linton
AU - K. C. Vickers
AU - A. C. Doran
AU - S. S. Davies
PY - 2026
DA - 2026/09/10
PB - bioRxiv
DO - 10.64898/2026.09.10.750792
UR - https://www.biorxiv.org/content/10.64898/2026.09.10.750792v1
AB - Objective: Impairments in efferocytosis, the phagocytic clearance of apoptotic cells, contribute to the development of chronic inflammation and promote the formation of large necrotic cores within atherosclerotic plaques. A better understanding of the factors that impair efferocytosis could lead to improved interventions. Many chronic inflammatory conditions feature excessive lipid peroxidation, which generates reactive lipid aldehydes that can potentially form N-aldehyde-modified phosphatidylethanolamines (NAMPs). We therefore investigated the extent to which levels of NAMPs are elevated under conditions of oxidative stress and whether exposure of macrophages to NAMPs inhibit efferocytosis. Approach and Results: The effects of synthetic NAMPs and lipid peroxidation on efferocytosis were measured using the Incucyte Live-Cell Analysis System to monitor rate of ingestion of CypHer-labeled apoptotic cells by cultured bone marrow-derived macrophages in real time. The extent of NAMP formation under various conditions was examined using liquid chromatography coupled with mass spectrometry. Several representative species of NAMPs (N-isolevuglandin-phosphatidylethanolamine, N-IsoLG-PE; N-4-hydroxynonenal-phosphatidylethanolamine, N-HNE-PE; and N-azeloyl-phosphatidylethanolamine, N-Aze-PE) inhibited efferocytosis in a concentration-dependent manner. Hydrolysis of NAMPs by recombinant N-acyl phosphatidylethanolamine hydrolyzing phospholipase D (NAPE-PLD) abolished their inhibitory activity, whereas genetic deletion of macrophage NAPE-PLD enhanced NAMP-mediated inhibition of efferocytosis. Blocking the inhibitor of lipid peroxidation, glutathione peroxidase 4 (GPX4), increased macrophage NAMP concentrations and impaired efferocytosis. Unmodified high-density lipoprotein (HDL) promoted efferocytosis, but exposing HDL to reactive lipid aldehydes or peroxidizing agents markedly increased NAMPs and this modified HDL inhibited efferocytosis. HDL isolated from subjects with familial hypercholesterolemia had elevated levels of multiple NAMP species. NAMPs impaired macrophage cholesterol efflux, which is required for continual efferocytosis. Conclusion: NAMPs accumulate under conditions associated with lipid peroxidation and inhibit the ability of macrophages to carry out efferocytosis.
ER -