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Li S, Navia-Pelaez JM, Choi SH, Miller YI. Macrophage inflammarafts in atherosclerosis. Curr Opin Lipidol 2023; 34:189-195. [PMID: 37527160 DOI: 10.1097/mol.0000000000000888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
PURPOSE OF REVIEW Advances in single cell techniques revealed a remarkable diversity in macrophage gene expression profiles in atherosclerosis. However, the diversity of functional processes at the macrophage plasma membrane remains less studied. This review summarizes recent advances in characterization of lipid rafts, where inflammatory receptors assemble, in macrophages that undergo reprogramming in atherosclerotic lesions and in vitro under conditions relevant to the development of atherosclerosis. RECENT FINDINGS The term inflammarafts refers to enlarged lipid rafts with increased cholesterol content, hosting components of inflammatory receptor complexes assembled in close proximity, including TLR4-TLR4, TLR2-TLR1 and TLR2-CD36 dimers. Macrophages decorated with inflammarafts maintain chronic inflammatory gene expression and are primed to an augmented response to additional inflammatory stimuli. In mouse atherosclerotic lesions, inflammarafts are expressed primarily in nonfoamy macrophages and less in lipid-laden foam cells. This agrees with the reported suppression of inflammatory programs in foam cells. In contrast, nonfoamy macrophages expressing inflammarafts are the major inflammatory population in atherosclerotic lesions. Discussed are emerging reports that help understand formation and persistence of inflammarafts and the potential of inflammarafts as a novel therapeutic target. SUMMARY Chronic maintenance of inflammarafts in nonfoamy macrophages serves as an effector mechanism of inflammatory macrophage reprogramming in atherosclerosis.
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Affiliation(s)
- Shenglin Li
- Department of Medicine, University of California, San Diego, California, USA
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Lin HP, Singla B, Ahn W, Ghoshal P, Blahove M, Cherian-Shaw M, Chen A, Haller A, Hui DY, Dong K, Zhou J, White J, Stranahan AM, Jasztal A, Lucas R, Stansfield BK, Fulton D, Chlopicki S, Csányi G. Receptor-independent fluid-phase macropinocytosis promotes arterial foam cell formation and atherosclerosis. Sci Transl Med 2022; 14:eadd2376. [PMID: 36130017 PMCID: PMC9645012 DOI: 10.1126/scitranslmed.add2376] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Accumulation of lipid-laden foam cells in the arterial wall plays a central role in atherosclerotic lesion development, plaque progression, and late-stage complications of atherosclerosis. However, there are still fundamental gaps in our knowledge of the underlying mechanisms leading to foam cell formation in atherosclerotic arteries. Here, we investigated the role of receptor-independent macropinocytosis in arterial lipid accumulation and pathogenesis of atherosclerosis. Genetic inhibition of fluid-phase macropinocytosis in myeloid cells (LysMCre+ Nhe1fl/fl) and repurposing of a Food and Drug Administration (FDA)-approved drug that inhibits macrophage macropinocytosis substantially decreased atherosclerotic lesion development in low-density lipoprotein (LDL) receptor-deficient and Apoe-/- mice. Stimulation of macropinocytosis using genetic (H-RASG12V) and physiologically relevant approaches promoted internalization of unmodified native (nLDL) and modified [e.g., acetylated (ac) and oxidized (ox) LDL] lipoproteins in both wild-type and scavenger receptor (SR) knockout (Cd36-/-/Sra-/-) macrophages. Pharmacological inhibition of macropinocytosis in hypercholesterolemic wild-type and Cd36-/-/Sra-/- mice identified an important role of macropinocytosis in LDL uptake by lesional macrophages and development of atherosclerosis. Furthermore, serial section high-resolution imaging, LDL immunolabeling, and three-dimensional (3D) reconstruction of subendothelial foam cells provide visual evidence of lipid macropinocytosis in both human and murine atherosclerotic arteries. Our findings complement the SR paradigm of atherosclerosis and identify a therapeutic strategy to counter the development of atherosclerosis and cardiovascular disease.
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Affiliation(s)
- Hui-Ping Lin
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - Bhupesh Singla
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - WonMo Ahn
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - Pushpankur Ghoshal
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - Maria Blahove
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - Mary Cherian-Shaw
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - Alex Chen
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
| | - April Haller
- Department of Pathology, University of Cincinnati College of Medicine, USA
| | - David Y. Hui
- Department of Pathology, University of Cincinnati College of Medicine, USA
| | - Kunzhe Dong
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, USA
| | - Jiliang Zhou
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, USA
| | - Joseph White
- Department of Pathology, Medical College of Georgia, Augusta University, USA
| | - Alexis M. Stranahan
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, USA
| | - Agnieszka Jasztal
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Rudolf Lucas
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, USA
| | - Brian K. Stansfield
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
- Department of Pediatrics, Medical College of Georgia, Augusta University, USA
| | - David Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, USA
| | - Stefan Chlopicki
- Jagiellonian Centre for Experimental Therapeutics, Jagiellonian University, Krakow, Poland
| | - Gábor Csányi
- Vascular Biology Center, Medical College of Georgia, Augusta University, USA
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta University, USA
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Castaño D, Rattanasopa C, Monteiro-Cardoso VF, Corlianò M, Liu Y, Zhong S, Rusu M, Liehn EA, Singaraja RR. Lipid efflux mechanisms, relation to disease and potential therapeutic aspects. Adv Drug Deliv Rev 2020; 159:54-93. [PMID: 32423566 DOI: 10.1016/j.addr.2020.04.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 02/06/2023]
Abstract
Lipids are hydrophobic and amphiphilic molecules involved in diverse functions such as membrane structure, energy metabolism, immunity, and signaling. However, altered intra-cellular lipid levels or composition can lead to metabolic and inflammatory dysfunction, as well as lipotoxicity. Thus, intra-cellular lipid homeostasis is tightly regulated by multiple mechanisms. Since most peripheral cells do not catabolize cholesterol, efflux (extra-cellular transport) of cholesterol is vital for lipid homeostasis. Defective efflux contributes to atherosclerotic plaque development, impaired β-cell insulin secretion, and neuropathology. Of these, defective lipid efflux in macrophages in the arterial walls leading to foam cell and atherosclerotic plaque formation has been the most well studied, likely because a leading global cause of death is cardiovascular disease. Circulating high density lipoprotein particles play critical roles as acceptors of effluxed cellular lipids, suggesting their importance in disease etiology. We review here mechanisms and pathways that modulate lipid efflux, the role of lipid efflux in disease etiology, and therapeutic options aimed at modulating this critical process.
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Abstract
The reduction of plasma apolipoprotein B (apoB) containing lipoproteins has long been pursued as the main modifiable risk factor for the development of cardiovascular disease (CVD). This has led to an intense search for strategies aiming at reducing plasma apoB-lipoproteins, culminating in reduction of overall CV risk. Despite 3 decades of progress, CVD remains the leading cause of morbidity and mortality worldwide and, as such, new therapeutic targets are still warranted. Clinical and preclinical research has moved forward from the original concept, under which some lipids must be accumulated and other removed to achieve the ideal condition in disease prevention, into the concept that mechanisms that orchestrate lipid movement between lipoproteins, cells and organelles is equally involved in CVD. As such, this review scrutinizes potentially atherogenic changes in lipid trafficking and assesses the molecular mechanisms behind it. New developments in risk assessment and new targets for the mitigation of residual CVD risk are also addressed.
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Affiliation(s)
- Andrei C Sposito
- Atherosclerosis and Vascular Biology Laboratory (Aterolab), State University of Campinas (Unicamp), São Paulo, Brazil.
| | | | - Joaquim Barreto
- Atherosclerosis and Vascular Biology Laboratory (Aterolab), State University of Campinas (Unicamp), São Paulo, Brazil
| | - Ilaria Zanotti
- Department of Food and Drug, University of Parma, Parma, Italy
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Abstract
PURPOSE OF REVIEW Lipoprotein-induced intracellular lipid accumulation (foam cell formation) is a trigger of atherogenesis at the subendothelial arterial cell level. The purpose of this review is to describe the recent data related to the possible mechanisms of LDL-induced formation of lipid-laden foam cells and their role in the onset and development of atherosclerotic lesion. RECENT FINDINGS The most interesting current studies are related to the factors affecting foam cell formation. SUMMARY The phenomenon of lipid accumulation in cultured cells became the basis for creating a cellular test system that has already been successfully applied for development of drugs possessing direct antiatherosclerotic activity, and then the efficacy of these drugs was demonstrated in clinical studies. Moreover, this test system could be used for diagnostic assessing lipoproteins atherogenicity.
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Affiliation(s)
- Alexander N Orekhov
- Laboratory of Angiopatology, Institute of General Pathology and Pathophysiology
- Institute for Atherosclerosis Research, Skolkovo Innovative Center, Moscow, Russia
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