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Deisl C, Moe OW, Hilgemann DW. Constitutive Plasma Membrane Turnover in T-REx293 cells via Ordered Membrane Domain Endocytosis under Mitochondrial Control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.17.576124. [PMID: 38293164 PMCID: PMC10827192 DOI: 10.1101/2024.01.17.576124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Clathrin/dynamin-independent endocytosis of ordered plasma membrane domains (ordered membrane domain endocytosis, OMDE) can become massive in response to cytoplasmic Ca elevations, G protein activation by non-hydrolyzable GTP analogs, and enhanced oxidative metabolism. In patch-clamped murine bone marrow macrophages (BMMs), cytoplasmic succinate and pyruvate, but not β-hydroxybutyrate, induce OMDE of 75% of the plasma membrane within 2 min. The responses require palmitoylation of membrane proteins, being decreased by 70% in BMMs lacking the acyltransferase, DHHC5, by treatment with carnitine to shift long-chain acyl groups from cytoplasmic to mitochondrial acyl-CoAs, by bromopalmitate/albumin complexes to block DHHCs, and by the mitochondria-specific cyclosporin, NIM811, to block permeability transition pores that may release mitochondrial coenzyme A into the cytoplasm. Using T-REx293 cells, OMDE amounts to 40% with succinate, pyruvate, or GTPγS, and it is inhibited by actin cytoskeleton disruption. Pyruvate-induced OMDE is blocked by the hydrophobic antioxidant, edaravone, which prevents permeability transition pore openings. Using fluorescent 3kD dextrans to monitor endocytosis, OMDE appears to be constitutively active in T-REx293 cells but not in BMMs. After 1 h without substrates or bicarbonate, pyruvate and hydroxybutyrate inhibit constitutive OMDE, as expected for a shift of CoA from long-chain acyl-CoAs to other CoA metabolites. In the presence of bicarbonate, pyruvate strongly enhances OMDE, which is then blocked by β-hydroxybutyrate, bromopalmitate/albumin complexes, cyclosporines, or edaravone. After pyruvate responses, T-REx293 cells grow normally with no evidence for apoptosis. Fatty acid-free albumin (15 μM) inhibits basal OMDE in T-REx293 cells, as do cyclosporines, carnitine, and RhoA blockade. Surprisingly, OMDE in the absence of substrates and bicarbonate is not inhibited by siRNA knockdown of the acyltransferases, DHHC5 or DHHC2, which are required for activated OMDE in patch clamp experiments. We verify biochemically that small CoA metabolites decrease long-chain acyl-CoAs. We verify also that palmitoylations of many PM-associated proteins decrease and increase when OMDE is inhibited and stimulated, respectively, by different metabolites. STED microscopy reveals that vesicles formed during constitutive OMDE in T-REX293 cells have 90 to 130 nm diameters. In summary, OMDE is likely a major G-protein-dependent endocytic mechanism that can be constitutively active in some cell types, albeit not BMMs. OMDE depends on different DHHC acyltransferases in different circumstances and can be limited by local supplies of fatty acids, CoA, and long-chain acyl-CoAs.
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Affiliation(s)
- Christine Deisl
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Orson W Moe
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Donald W Hilgemann
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Wang Y, Wang X, Luo Y, Zhang J, Lin Y, Wu J, Zeng B, Liu L, Yan P, Liang J, Guo H, Jin L, Tang Q, Long K, Li M. Spatio-temporal transcriptome dynamics coordinate rapid transition of core crop functions in 'lactating' pigeon. PLoS Genet 2023; 19:e1010746. [PMID: 37289658 PMCID: PMC10249823 DOI: 10.1371/journal.pgen.1010746] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 04/14/2023] [Indexed: 06/10/2023] Open
Abstract
Pigeons (Columba livia) are among a select few avian species that have developed a specialized reproductive mode wherein the parents produce a 'milk' in their crop to feed newborn squabs. Nonetheless, the transcriptomic dynamics and role in the rapid transition of core crop functions during 'lactation' remain largely unexplored. Here, we generated a de novo pigeon genome assembly to construct a high resolution spatio-temporal transcriptomic landscape of the crop epithelium across the entire breeding stage. This multi-omics analysis identified a set of 'lactation'-related genes involved in lipid and protein metabolism, which contribute to the rapid functional transitions in the crop. Analysis of in situ high-throughput chromatin conformation capture (Hi-C) sequencing revealed extensive reorganization of promoter-enhancer interactions linked to the dynamic expression of these 'lactation'-related genes between stages. Moreover, their expression is spatially localized in specific epithelial layers, and can be correlated with phenotypic changes in the crop. These results illustrate the preferential de novo synthesis of 'milk' lipids and proteins in the crop, and provides candidate enhancer loci for further investigation of the regulatory elements controlling pigeon 'lactation'.
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Affiliation(s)
- Yujie Wang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Xun Wang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
| | - Yi Luo
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jiaman Zhang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Yu Lin
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jie Wu
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Bo Zeng
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
| | - Lei Liu
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Peiqi Yan
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Jiyuan Liang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hongrui Guo
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Long Jin
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
| | - Qianzi Tang
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
| | - Keren Long
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
| | - Mingzhou Li
- Livestock and Poultry Multi-omics Key Laboratory of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
- Animal Breeding and Genetics Key Laboratory of Sichuan Province, Institute of Animal Genetics and Breeding, Sichuan Agricultural University, Chengdu, China
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3
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da Costa A, de Carvalho CA, Nascimento ND, de Andrade HF. Scavenger receptors mediate increased uptake of irradiated T.gondii extracts by J774 macrophages. Int J Radiat Biol 2023; 99:1559-1569. [PMID: 36862984 DOI: 10.1080/09553002.2023.2187475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 02/20/2023] [Indexed: 03/04/2023]
Abstract
PURPOSE Protein extracts developed increased immunogenicity without the aid of adjuvants after gamma irradiation. Gamma irradiation of snake venom increased antivenin production by detoxification and enhanced immunity, probably due preferential uptake of irradiated venoms by macrophage scavenger receptors. We studied this uptake of irradiated soluble Toxoplasma gondii extract (STag) by the J774 macrophage cell line similar to antigen presenting cells. MATERIAL AND METHODS We labeled STag by biosynthesis in living tachyzoites with radioactive amino acids before purification and irradiation or by adding labels as biotin or fluorescein in stored STag, for quantitative studies or subcellular distribution visualization. RESULTS There was enhanced binding and uptake of irradiated STag into the cells compared to non-irradiated STag. Using fluorescein labeled antigens and morphological assays, we confirmed that cells avidly ingested both native and irradiated proteins but native STag were digested after ingestion while irradiated proteins remained in the cell, suggesting diverse intracytoplasmic pathways. Native or irradiated STag present the same in vitro sensitivity to three types of peptidases. Inhibitors of scavenger receptors (SRs) such as Dextran sulfate (SR-A1 blocker) or Probucol (SR-B blocker) affect the specific uptake of irradiated antigens, suggesting its association with enhanced immunity. CONCLUSIONS Our data suggests that cell SRs recognize irradiated proteins, mainly SRs for oxidized proteins, leading to antigen uptake by an intracytoplasmic pathway with fewer peptidases that prolongs presentation to nascent major histocompatibility complex I or II and enhances immunity by better antigen presentation.
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Affiliation(s)
- Andrea da Costa
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, Brazil
| | | | - Nanci do Nascimento
- Centro de Biotecnologia, Instituto de Pesquisa Energéticas e Nucleares, IPEN/CNEN-SP, Sao Paulo, Brazil
| | - Heitor Franco de Andrade
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, Brazil
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Rezende L, Couto NFD, Fernandes-Braga W, Epshtein Y, Alvarez-Leite JI, Levitan I, Andrade LDO. OxLDL induces membrane structure rearrangement leading to biomechanics alteration and migration deficiency in macrophage. BIOCHIMICA ET BIOPHYSICA ACTA (BBA) - BIOMEMBRANES 2022; 1864:183951. [PMID: 35504320 DOI: 10.1016/j.bbamem.2022.183951] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 11/30/2022]
Abstract
Cholesterol sequestration from plasma membrane has been shown to induce lipid packing disruption, causing actin cytoskeleton reorganization and polymerization, increasing cell stiffness and inducing lysosomal exocytosis in non-professional phagocytes. Similarly, oxidized form of low-density lipoprotein (oxLDL) has also been shown to disrupt lipid organization and packing in endothelial cells, leading to biomechanics alterations that interfere with membrane injury and repair. For macrophages, much is known about oxLDL effects in cell activation, cytokine production and foam cell formation. However, little is known about its impact in the organization of macrophage membrane structured domains and cellular mechanics, the focus of the present study. Treatment of bone marrow-derived macrophages (BMDM) with oxLDL not only altered membrane structure, and potentially the distribution of raft domains, but also induced actin rearrangement, diffuse integrin distribution and cell shrinkage, similarly to observed upon treatment of these cells with MβCD. Those alterations led to decreased migration efficiency. For both treatments, higher co-localization of actin cytoskeleton and GM1 was observed, indicating a similar mechanism of action involving raft-like domain dynamics. Lastly, like MβCD treatment, oxLDL also induced lysosomal spreading in BMDM. We propose that OxLDL induced re-organization of membrane/cytoskeleton complex in macrophages can be attributed to the insertion of oxysterols into the membrane, which lead to changes in lipid organization and disruption of membrane structure, similar to the effect of cholesterol depletion by MβCD treatment. These results indicate that oxLDL can induce physical alterations in the complex membrane/cytoskeleton of macrophages, leading to significant biomechanical changes that compromise cell behavior.
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Affiliation(s)
- Luisa Rezende
- Department of Morphology/Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Natalia Fernanda Do Couto
- Department of Morphology/Federal University of Minas Gerais, Belo Horizonte, MG, Brazil; Department of Medicine, University of Illinois at Chicago, Chicago, USA
| | - Weslley Fernandes-Braga
- Department of Biochemistry and Immunology/Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Yulia Epshtein
- Department of Medicine, University of Illinois at Chicago, Chicago, USA
| | | | - Irena Levitan
- Department of Medicine, University of Illinois at Chicago, Chicago, USA
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Vogel A, Brunner JS, Hajto A, Sharif O, Schabbauer G. Lipid scavenging macrophages and inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159066. [PMID: 34626791 DOI: 10.1016/j.bbalip.2021.159066] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 08/18/2021] [Indexed: 12/11/2022]
Abstract
Macrophages are professional phagocytes, indispensable for maintenance of tissue homeostasis and integrity. Depending on their resident tissue, macrophages are exposed to highly diverse metabolic environments. Adapted to their niche, they can contribute to local metabolic turnover through metabolite uptake, conversion, storage and release. Disturbances in tissue homeostasis caused by infection, inflammation or damage dramatically alter the local milieu, impacting macrophage activation status and metabolism. In the case of persisting stimuli, defective macrophage responses ensue, which can promote tissue damage and disease. Especially relevant herein are disbalances in lipid rich environments, where macrophages are crucially involved in lipid uptake and turnover, preventing lipotoxicity. Lipid uptake is to a large extent facilitated by macrophage expressed scavenger receptors that are dynamically regulated and important in many metabolic diseases. Here, we review the receptors mediating lipid uptake and summarize recent findings on their role in health and disease. We further highlight the underlying pathways driving macrophage lipid acquisition and their impact on myeloid metabolic remodelling.
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Affiliation(s)
- Andrea Vogel
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Julia Stefanie Brunner
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Alexander Hajto
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria
| | - Omar Sharif
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
| | - Gernot Schabbauer
- Institute for Vascular Biology, Centre for Physiology and Pharmacology, Medical University Vienna, Vienna, Austria; Christian Doppler Laboratory for Arginine Metabolism in Rheumatoid Arthritis and Multiple Sclerosis, Vienna, Austria.
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6
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Chen G, Zhou Y, Zhang W, Qin Y, Wei B, Sun Y, Chen Y. Methyl-β-cyclodextrin suppresses the monocyte-endothelial adhesion triggered by lipopolysaccharide (LPS) or oxidized low-density lipoprotein (oxLDL). PHARMACEUTICAL BIOLOGY 2021; 59:1036-1044. [PMID: 34362284 PMCID: PMC8354180 DOI: 10.1080/13880209.2021.1953540] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
CONTEXT Recent studies demonstrated the anti-atherosclerotic efficacy of cyclodextrin. However, it remains unclear whether cyclodextrin exerts the anti-atherosclerotic effect via regulating monocyte-endothelial adhesion. OBJECTIVE To answer that question by recruiting methyl-β-cyclodextrin (MβCD) as a cyclodextrin representative. MATERIALS AND METHODS Human umbilical vein endothelial cells (HUVECs) were not treated, or treated with 1 µg/mL liposaccharide (LPS) or 50 µg/mL oxidized low-density lipoprotein (oxLDL) for 12 h, 5 mM MβCD for 1 h, and LPS/oxLDL (1 and 50 µg/mL, respectively for 12 h) plus MβCD (5 mM for 1 h), respectively. The effects of MβCD on LPS/oxLDL-triggered monocyte-endothelial adhesion and related molecules in signalling pathways were evaluated via confocal microscopy, flow cytometry, RT-PCR, western blotting, and cell adhesion assay. RESULTS MβCD with an IC50 of 27.66 mM (1 h treatment) exerted no significant cytotoxicity at ≤5 mM for ≤2 h. Compared with the control, both LPS and oxLDL induced an ∼2-3-fold increase in adhesion molecule expression (ICAM-1 and VCAM-1 at protein and mRNA levels) and NF-κB phosphorylation (p-NF-κB/pP65), an increase in IκB kinase (IKK), and a decrease in phosphorylated protein kinase B (p-Akt), respectively. Moreover, more monocytes (2-fold higher for LPS and 15% higher for oxLDL) were attached on LPS/oxLDL-stimulated HUVECs. 5 mM MβCD reversed the LPS/oxLDL-induced changes back to the control levels. CONCLUSIONS MβCD significantly suppresses the LPS/oxLDL-triggered monocyte-endothelial adhesion by downregulating adhesion molecule expression probably via LPS-IKK-NF-κB or oxLDL-Akt-NF-κB pathway. This study demonstrates a potential mechanism of the anti-atherosclerotic efficacy of cyclodextrin from the angle of monocyte-endothelial adhesion.
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Affiliation(s)
- Guo Chen
- College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Yun Zhou
- College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Wendiao Zhang
- Jiangxi Key Laboratory for Microscale Interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, China
| | - Ying Qin
- College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Key Laboratory for Microscale Interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, China
| | - Bo Wei
- College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Yanan Sun
- Jiangxi Key Laboratory for Microscale Interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, China
| | - Yong Chen
- College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
- Jiangxi Key Laboratory for Microscale Interdisciplinary Study, Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi, China
- CONTACT Yong Chen ; College of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
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7
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Lands B. Lipid nutrition: "In silico" studies and undeveloped experiments. Prog Lipid Res 2021; 85:101142. [PMID: 34818526 DOI: 10.1016/j.plipres.2021.101142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 12/14/2022]
Abstract
This review examines lipids and lipid-binding sites on proteins in relation to cardiovascular disease. Lipid nutrition involves food energy from ingested fatty acids plus fatty acids formed from excess ingested carbohydrate and protein. Non-esterified fatty acids (NEFA) and lipoproteins have many detailed attributes not evident in their names. Recognizing attributes of lipid-protein interactions decreases unexpected outcomes. Details of double bond position and configuration interacting with protein binding sites have unexpected consequences in acyltransferase and cell replication events. Highly unsaturated fatty acids (HUFA) have n-3 and n-6 motifs with documented differences in intensity of destabilizing positive feedback loops amplifying pathophysiology. However, actions of NEFA have been neglected relative to cholesterol, which is co-produced from excess food. Native low-density lipoproteins (LDL) bind to a high-affinity cell surface receptor which poorly recognizes biologically modified LDLs. NEFA increase negative charge of LDL and decrease its processing by "normal" receptors while increasing processing by "scavenger" receptors. A positive feedback loop in the recruitment of monocytes and macrophages amplifies chronic inflammatory pathophysiology. Computer tools combine multiple components in lipid nutrition and predict balance of energy and n-3:n-6 HUFA. The tools help design and execute precise clinical nutrition monitoring that either supports or disproves expectations.
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Affiliation(s)
- Bill Lands
- Fellow ASN, AAAS, SFRBM, ISSFAL, College Park, MD, USA.
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8
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Song Q, Wang XQ, Holmes TR, Bonkowski M, Roth EW, Ponedal A, Mirkin C, Paller AS. Epidermal SR-A Complexes Are Lipid Raft Based and Promote Nucleic Acid Nanoparticle Uptake. J Invest Dermatol 2021; 141:1428-1437.e8. [PMID: 33385397 PMCID: PMC8154648 DOI: 10.1016/j.jid.2020.10.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/13/2020] [Accepted: 10/05/2020] [Indexed: 01/22/2023]
Abstract
Scavenger receptors clear pathogens, transport lipid, and mediate polyanionic ligand uptake in macrophages, but their expression and role in the skin are poorly understood. Although the epidermal barrier typically excludes nucleic acid entry, topically applied, spherically arranged oligonucleotide nanoconjugates (spherical nucleic acids [SNAs]) penetrate mouse skin, three-dimensional (3D) skin equivalents, and human skin. We explored the mechanism of SNA uptake in normal human epidermal keratinocytes and 3D skin equivalents. Normal human epidermal keratinocytes and 3D raft treatment with SR-A inhibitors reduced SNA uptake by >80%. The human epidermis expresses SR-As SCARA3 and, to a lesser extent, MARCO. Simultaneous lentiviral knockdown of SCARA3 and MARCO reduced SNA uptake in normal human epidermal keratinocytes and 3D rafts after topical application, affirming a role for SR-As in SNA uptake and 3D raft penetration. Incubation of normal human epidermal keratinocytes at 4oC or with sodium azide prevented SNA uptake, suggesting active endocytosis. Endocytosis inhibitors, immunofluorescence, immunoprecipitation, and knockdown studies localized functional SR-As to FLOT-1-containing lipid rafts throughout the epidermis and CAV-1-containing rafts only in the upper epidermis. These studies suggest a central role for SR-A complexes in epidermal lipid rafts in mediating the uptake of nucleic acid‒laden nanoparticles.
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Affiliation(s)
- Qian Song
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Xiao-Qi Wang
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Thomas R Holmes
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Michael Bonkowski
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Eric W Roth
- Northwestern University Atomic and Nanoscale Characterization Experimental Center (NUANCE), Evanston, Illinois, USA
| | - Adam Ponedal
- Department of Chemical & Biological Engineering, Northwestern University, Evanston, Illinois, USA; International Institute for Nanotechnology, Northwestern University, Evanston, Illinois, USA
| | - Chad Mirkin
- International Institute for Nanotechnology, Northwestern University, Evanston, Illinois, USA; Department of Chemistry, Northwestern University, Evanston, Illinois, USA
| | - Amy S Paller
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA; International Institute for Nanotechnology, Northwestern University, Evanston, Illinois, USA.
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9
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Interactions of different lipoproteins with supported phospholipid raft membrane (SPRM) patterns to understand similar in-vivo processes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183535. [PMID: 33358851 DOI: 10.1016/j.bbamem.2020.183535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/01/2020] [Accepted: 12/11/2020] [Indexed: 11/21/2022]
Abstract
To better understand how lipoproteins interact and enter endothelium and participate in cellular processes, we investigated preferential lipid partitioning of triglyceride rich lipoproteins (TGRL), chylomicrons (CM), low density lipoproteins (LDL), very low density lipoproteins (VLDL) and their lipolysis products using supported phospholipid raft membrane (SPRM) patterns. We prepared SPRM patterns with Texas red labeled phospholipid patterns and Marina blue labeled raft patterns and added Atto-520 labeled lipoproteins (TGRL, CM, VLDL, LDL) and their lipolysis products in separate experiments and characterized these interactions using fluorescence microscopy. We observed that VLDL and LDL preferentially interacted with raft patterns. In contrast the TGRL and lipolysed products of TGRL interacted with both the patterns, slightly elevated preference for raft patterns and CM and its lipolysis products showed greater affinity to phospholipid patterns. The clear preference of VLDL and LDL for raft patterns suggests that these lipoproteins associate with cholesterol and sphingomyelin rich lipid micro-domains during their early interactions with endothelial cells, leading to atherosclerosis.
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10
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da Costa A, Nascimento ND, Galisteo AJ, Dias Dos Passos AB, de Andrade HF. Radiation effects on Toxoplasma antigens: different immune responses of irradiated intact tachyzoites or soluble antigens in experimental mice models. Int J Radiat Biol 2020; 96:697-706. [PMID: 31855098 DOI: 10.1080/09553002.2020.1704298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Purpose: Purpose: Protein irradiation causes aggregation, chain breakage, and oxidation, enhancing its uptake by antigen-presenting cells. To evaluate if irradiated proteins participate on the protection, we studied the immune response induced in mice immunized with irradiated soluble extracts of T. gondii tachyzoites (STag) or irradiated intact T. gondii RH tachyzoites (RH0.25 kGy).Material and Methods: Soluble extracts of Toxoplasma gondii tachyzoites (STag) were irradiated at different dose by Cobalt-60 source. By polyacrylamide gel electrophoresis (SDS-Page) we evaluated the effects on primary structures of protein STags induced by irradiation. By Enzyme-linked Immunosorbent Assay (ELISA) we evaluated the difference between humoral immune response induced by irradiated STag or RH tachyzoites in immunized mice from the detection of specific immunoglobulin G (IgG) antibodies in the serum of immunized mice. From challenge with viable RH strain of T. gondii we evaluated the protection induced in the immunized animals. By cytometry we performed the phenotyping of T and B lymphocytes in the peripheral blood of the immunized animals.Results: Irradiation dose of 1.5 kGy induced minimal changes in most proteins, without affecting their antigenicity or immunogenicity. Immunization showed saturation at the dose of 10 µg/mice, with worst response at higher doses. STag irradiated at 1.5 kGy (STag1.5 kGy) induced higher survival and protection similar to T. gondii RH strain irradiated at 0.25 kGy (RH0.25 kGy), with higher serum levels of high affinity IgG compared to STag native. Blood immune memory cells of mice immunized with STag1.5 kGy had higher proportions of CD19+ (cluster of differentiation 19) and CD4+ (cluster of differentiation 14) cells, whereas mice RH0.25 kGy had high proportion of memory CD8+ (cluster of differentiation 8) cells.Conclusions: Our data suggest that major histocompatibility complex type I (MHCI) pathway, appears seem to be used by RH0.25 kGy to generate cytotoxic cells while STag1.5 kGy uses a major histocompatibility complex type II (MHCII) pathway for B-cell memory, but both induce sufficient immune response for protection in mice without any adjuvant. Irradiation of soluble protein extracts enhances their immune response, allowing similar protection against T. gondii in mice as compared to irradiated intact parasites.
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Affiliation(s)
- Andrea da Costa
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brasil
| | - Nanci do Nascimento
- Instituto de Pesquisas Energéticas e Nucleares, Centro de Biotecnologia, São Paulo, Brasil
| | - Andrés Jimenez Galisteo
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brasil.,Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brasil
| | - Aline Bastos Dias Dos Passos
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brasil
| | - Heitor Franco de Andrade
- Laboratório de Protozoologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brasil
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11
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Riley DRJ, Khalil JS, Naseem KM, Rivero F. Biochemical and immunocytochemical characterization of coronins in platelets. Platelets 2019; 31:913-924. [PMID: 31801396 PMCID: PMC7497283 DOI: 10.1080/09537104.2019.1696457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Rapid reorganization of the actin cytoskeleton in response to receptor-mediated signaling cascades allows platelets to transition from a discoid shape to a flat spread shape upon adhesion to damaged vessel walls. Coronins are conserved regulators of the actin cytoskeleton turnover but they also participate in signaling events. To gain a better picture of their functions in platelets we have undertaken a biochemical and immunocytochemical investigation with a focus on Coro1. We found that class I coronins Coro1, 2 and 3 are abundant in human and mouse platelets whereas little Coro7 can be detected. Coro1 is mainly cytosolic, but a significant amount associates with membranes in an actin-independent manner and does not translocate from or to the membrane fraction upon exposure to thrombin, collagen or prostacyclin. Coro1 rapidly translocates to the Triton insoluble cytoskeleton upon platelet stimulation with thrombin or collagen. Coro1, 2 and 3 show a diffuse cytoplasmic localization with discontinuous accumulation at the cell cortex and actin nodules of human platelets, where all three coronins colocalize. Our data are consistent with a role of coronins as integrators of extracellular signals with actin remodeling and suggests a high extent of functional overlap among class I coronins in platelets.
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Affiliation(s)
- David R J Riley
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
| | - Jawad S Khalil
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK.,School of Physiology, Pharmacology and Neuroscience, Faculty of Life Sciences, University of Bristol , Bristol, UK
| | - Khalid M Naseem
- Leeds Institute for Cardiovascular and Metabolic Medicine, University of Leeds , Leeds, UK
| | - Francisco Rivero
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull , Hull, UK
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12
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Meyre D, Andress EJ, Sharma T, Snippe M, Asif H, Maharaj A, Vatin V, Gaget S, Besnard P, Choquet H, Froguel P, Linton KJ. Contribution of rare coding mutations in CD36 to type 2 diabetes and cardio-metabolic complications. Sci Rep 2019; 9:17123. [PMID: 31748580 PMCID: PMC6868229 DOI: 10.1038/s41598-019-53388-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 06/28/2019] [Indexed: 01/10/2023] Open
Abstract
We sequenced coding regions of the cluster of differentiation 36 (CD36) gene in 184 French individuals of European ancestry presenting simultaneously with type 2 diabetes (T2D), arterial hypertension, dyslipidemia, and coronary heart disease. We identified rare missense mutations (p.Pro191Leu/rs143150225 and p.Ala252Val/rs147624636) in two heterozygous cases. The two CD36 mutation carriers had no family history of T2D and no clustering of cardio-metabolic complications. While the p.Pro191Leu mutation was found in 84 heterozygous carriers from five ethnic groups from the genome aggregation database (global frequency: 0.0297%, N = 141,321), only one European carrier of the p.Ala252Val mutation was identified (global frequency: 0.00040%, N = 125,523). The Pro191 and Ala252 amino acids were not conserved (74.8% and 68.9% across 131 animal species, respectively). In vitro experiments showed that the two CD36 mutant proteins are expressed and trafficked to the plasma membrane where they bind modified low-density-lipoprotein (LDL) cholesterol as normal. However, molecular modelling of the recent CD36 crystal structure showed that Pro191 was located at the exit/entrance gate of the lipid binding chamber and Ala252 was in line with the chamber. Overall, our data do not support a major contribution of CD36 rare coding mutations to T2D and its cardio-metabolic complications in the French population.
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Affiliation(s)
- David Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada. .,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada. .,CNRS UMR8199, Pasteur Institute of Lille, Lille University, Lille, France.
| | - Edward J Andress
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Tanmay Sharma
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Marjolein Snippe
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Hamza Asif
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Arjuna Maharaj
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - Vincent Vatin
- CNRS UMR8199, Pasteur Institute of Lille, Lille University, Lille, France
| | - Stefan Gaget
- CNRS UMR8199, Pasteur Institute of Lille, Lille University, Lille, France
| | - Philippe Besnard
- UMR Lipides/Nutrition/Cancer U1231 INSERM/University Bourgogne-Franche Comté/AgroSupDijon, Dijon, France
| | - Hélène Choquet
- CNRS UMR8199, Pasteur Institute of Lille, Lille University, Lille, France.,Kaiser Permanente Northern California (KPNC), Division of Research, Oakland, California, United States of America
| | - Philippe Froguel
- CNRS UMR8199, Pasteur Institute of Lille, Lille University, Lille, France. .,Department of Genomics of Common Disease, Imperial College London, London, United Kingdom.
| | - Kenneth J Linton
- Centre for Cell Biology and Cutaneous Research, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom.
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13
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14
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Autophagy differentially regulates macrophage lipid handling depending on the lipid substrate (oleic acid vs. acetylated-LDL) and inflammatory activation state. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:158527. [PMID: 31520777 DOI: 10.1016/j.bbalip.2019.158527] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/01/2019] [Accepted: 09/08/2019] [Indexed: 12/17/2022]
Abstract
The regulation of lipid droplet (LD) dynamics by autophagy in naïve macrophages is complex: Inhibiting autophagosome initiation steps attenuates oleic acid (OA) induced LD (OA-LD) biogenesis, whereas interfering with later-autophagosome maturation/lysosomal steps accelerates OA-LD biogenesis rate, but not OA-LD degradation. Here we hypothesized that regulation of macrophage lipid handling by autophagy may be lipid-substrate and activation-state-specific. Using automated quantitative live-cell imaging, initial LD biogenesis rate was ~30% slower when the lipid source was acetylated low density lipoprotein (acLDL) compared to OA. Yet, both were similarly affected by triacsin-C, an inhibitor of acyl-CoA synthase, which inhibited, and etomoxir, an inhibitor of acylcarnitine palmitoyl transferase (fatty acid oxidation), which augmented, LD biogenesis rates. An autophagy inducing peptide, Tat-Beclin1, enhanced the degradation, and inhibited (by 37%) the biogenesis of acLDL induced LD (acLDL-LD). Yet, Tat-Beclin1 increased OA-LD biogenesis rate by 70%. When macrophages were pre-activated with LPS + INFG they exhibited increased autophagosome number and area, and reduced BECN1 and ATG14 protein levels, which associated with a markedly attenuated autophagic flux. Concomitantly, OA-LD and acLDL-LD biogenesis rates increased 3 and 7.4-fold, respectively, but could not be further modulated by Tat-Beclin1, as observed in non-activated/naïve macrophages. We propose that macrophage autophagy, and/or components of its machinery, differentially regulate LD/foam-cell biogenesis depending on the lipid-source, and that inflammatory activation uncouples autophagy from LD biogenesis.
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15
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Prasad GVRK, Dhar V, Mukhopadhaya A. Vibrio cholerae OmpU Mediates CD36-Dependent Reactive Oxygen Species Generation Triggering an Additional Pathway of MAPK Activation in Macrophages. THE JOURNAL OF IMMUNOLOGY 2019; 202:2431-2450. [PMID: 30867241 DOI: 10.4049/jimmunol.1800389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 02/06/2019] [Indexed: 01/18/2023]
Abstract
OmpU, one of the porins of Gram-negative bacteria Vibrio cholerae, induces TLR1/2-MyD88-NF-κB-dependent proinflammatory cytokine production by monocytes and macrophages of human and mouse origin. In this study, we report that in both the cell types, OmpU-induced proinflammatory responses involve activation of MAPKs (p38 and JNK). Interestingly, we observed that in OmpU-treated macrophages, p38 activation is TLR2 dependent, but JNK activation happens through a separate pathway involving reactive oxygen species (ROS) generation by NADPH oxidase complex and mitochondrial ROS. Further, we observed that OmpU-mediated mitochondrial ROS generation probably depends on OmpU translocation to mitochondria and NADPH oxidase-mediated ROS production is due to activation of scavenger receptor CD36. For the first time, to our knowledge, we are reporting that a Gram-negative bacterial protein can activate CD36 as a pattern recognition receptor. Additionally, we found that in OmpU-treated monocytes, both JNK and p38 activation is linked to the TLR2 activation only. Therefore, the ability of macrophages to employ multiple receptors such as TLR2 and CD36 to recognize a single ligand, as in this case OmpU, probably explains the very basic nature of macrophages being more proinflammatory than monocytes.
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Affiliation(s)
- G V R Krishna Prasad
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, 140306 Punjab, India
| | - Vinica Dhar
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, 140306 Punjab, India
| | - Arunika Mukhopadhaya
- Department of Biological Sciences, Indian Institute of Science Education and Research Mohali, Mohali, 140306 Punjab, India
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16
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Yu XH, Zhang DW, Zheng XL, Tang CK. Cholesterol transport system: An integrated cholesterol transport model involved in atherosclerosis. Prog Lipid Res 2018; 73:65-91. [PMID: 30528667 DOI: 10.1016/j.plipres.2018.12.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/30/2018] [Accepted: 12/01/2018] [Indexed: 02/07/2023]
Abstract
Atherosclerosis, the pathological basis of most cardiovascular disease (CVD), is closely associated with cholesterol accumulation in the arterial intima. Excessive cholesterol is removed by the reverse cholesterol transport (RCT) pathway, representing a major antiatherogenic mechanism. In addition to the RCT, other pathways are required for maintaining the whole-body cholesterol homeostasis. Thus, we propose a working model of integrated cholesterol transport, termed the cholesterol transport system (CTS), to describe body cholesterol metabolism. The novel model not only involves the classical view of RCT but also contains other steps, such as cholesterol absorption in the small intestine, low-density lipoprotein uptake by the liver, and transintestinal cholesterol excretion. Extensive studies have shown that dysfunctional CTS is one of the major causes for hypercholesterolemia and atherosclerosis. Currently, several drugs are available to improve the CTS efficiently. There are also several therapeutic approaches that have entered into clinical trials and shown considerable promise for decreasing the risk of CVD. In recent years, a variety of novel findings reveal the molecular mechanisms for the CTS and its role in the development of atherosclerosis, thereby providing novel insights into the understanding of whole-body cholesterol transport and metabolism. In this review, we summarize the latest advances in this area with an emphasis on the therapeutic potential of targeting the CTS in CVD patients.
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Affiliation(s)
- Xiao-Hua Yu
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Medical Research Experiment Center, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan 421001, China
| | - Da-Wei Zhang
- Department of Pediatrics and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Alberta, Canada
| | - Xi-Long Zheng
- Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Medical Research Experiment Center, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan 421001, China.
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17
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Seixas E, Escrevente C, Seabra MC, Barral DC. Rab GTPase regulation of bacteria and protozoa phagocytosis occurs through the modulation of phagocytic receptor surface expression. Sci Rep 2018; 8:12998. [PMID: 30158654 PMCID: PMC6115379 DOI: 10.1038/s41598-018-31171-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 08/08/2018] [Indexed: 01/22/2023] Open
Abstract
Phagocytosis of invading microorganisms by professional phagocytic cells has a central role in innate immunity. However, several microorganisms developed strategies to subvert this process. Previously, we reported that bacteria and protozoa modulate differently the expression of Rab GTPases. Moreover, our results suggested that this modulation can contribute to avoid phagocytosis. Here, we investigated the mechanism by which the malaria parasite Plasmodium berghei and the bacterium Escherichia coli subvert phagocytosis through the modulation of Rab14 or Rab9a expression, respectively. We first confirmed that the scavenger receptor CD36 and the Toll-like receptor (TLR) 4 are required for the phagocytosis of P. berghei and E. coli, respectively. Interestingly, we observed that Rab14 silencing leads to an increase in the surface expression of CD36 in macrophages, which can explain the increase in the phagocytosis of P. berghei we reported previously. Similar results were obtained for Rab9a and TLR4, i.e. Rab9a silencing causes an upregulation of TLR4 surface expression in macrophages. Furthermore, we found that the decrease in the internalization of CD36 and TLR4, upon Rab14 or Rab9a silencing, respectively, can explain the increase in the surface levels of these receptors. Thus, our studies provide evidence that the modulation of phagocytosis caused by changes in Rab expression is operated, at least partly through changes in the surface levels of phagocytic receptors.
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Affiliation(s)
- Elsa Seixas
- Centro de Estudos de Doenças Crónicas, NOVA Medical School
- Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal.,Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Cristina Escrevente
- Centro de Estudos de Doenças Crónicas, NOVA Medical School
- Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Miguel C Seabra
- Centro de Estudos de Doenças Crónicas, NOVA Medical School
- Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Duarte C Barral
- Centro de Estudos de Doenças Crónicas, NOVA Medical School
- Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Lisboa, Portugal.
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18
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The membrane-associated fraction of cyclase associate protein 1 translocates to the cytosol upon platelet stimulation. Sci Rep 2018; 8:10804. [PMID: 30018317 PMCID: PMC6050311 DOI: 10.1038/s41598-018-29151-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/03/2018] [Indexed: 01/09/2023] Open
Abstract
Platelets undergo profound shape changes upon adhesion to damaged blood vessel walls that are mediated by reorganisation of the actin cytoskeleton in response to receptor-mediated signalling cascades. The highly conserved 56 kDa multidomain cyclase associated protein 1 (CAP1) works in concert with cofilin and profilin to modulate actin filament turnover by facilitating cofilin-mediated actin filament severing and depolymerisation and catalysing profilin-mediated regeneration of actin monomers for reutilisation in growing filaments. CAP1 is abundant in platelets but its roles remain unexplored. We report that in suspended platelets CAP1 localises predominantly at the cell cortex whereas in spread platelets it is uniformly distributed in the cytoplasm, with enrichment at the cell cortex and the periphery of actin nodules. Upon subcellular fractionation most CAP1 was found cytosolic but part associated to the membrane fraction in an actin-independent manner. Interestingly, upon stimulation with thrombin a significant proportion of the membrane-associated CAP1 translocates to the cytosol. This relocalisation was prevented by prior treatment with PGI2 or the nitric oxide donor GSNO, or by inhibition of GSK3. Our results place CAP1 at a crossroad of signalling pathways that control platelet activation by contributing to actin remodelling at the cell cortex and actin nodules during platelet spreading.
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19
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Shamsaldeen YA, Ugur R, Benham CD, Lione LA. Diabetic dyslipidaemia is associated with alterations in eNOS, caveolin-1, and endothelial dysfunction in streptozotocin treated rats. Diabetes Metab Res Rev 2018; 34:e2995. [PMID: 29471582 DOI: 10.1002/dmrr.2995] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/19/2018] [Accepted: 02/05/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Diabetes is a complex progressive disease characterized by chronic hyperglycaemia and dyslipidaemia associated with endothelial dysfunction. Oxidized LDL (Ox-LDL) is elevated in diabetes and may contribute to endothelial dysfunction. The aim of this study was to relate the serum levels of Ox-LDL with endothelial dysfunction in streptozotocin (STZ)-diabetic rats and to further explore the changes in endothelial nitric oxide synthase (eNOS) and caveolin-1 (CAV-1) expression in primary aortic endothelial cells. METHODS Diabetes was induced with a single intraperitoneal injection of STZ in male Wistar rats. During the hyperglycaemic diabetes state serum lipid markers, aortic relaxation and aortic endothelial cell eNOS and CAV-1 protein expressions were measured. RESULTS Elevated serum Ox-LDL (STZ 1486 ± 78.1 pg/mL vs control 732.6 ± 160.6 pg/mL, P < .05) was associated with hyperglycaemia (STZ 29 ± 0.9 mmol/L vs control: 7.2 ± 0.2 mmol/L, P < .001) and hypertriglyceridaemia (STZ 9.0 ± 1.5 mmol/L vs control: 3.0 ± 0.3 mmol/L, P < .01) in diabetic rats. A significant reduction was observed in STZ-diabetic aortic endothelial cell eNOS and CAV-1 of 40% and 30%, respectively, accompanied by a compromised STZ-diabetic carbachol-induced vasodilation (STZ 29.6 ± 9.3% vs control 77.2 ± 2.5%, P < .001). CONCLUSIONS The elevated serum Ox-LDL in hyperglycaemic STZ-diabetic rats may contribute to diabetic endothelial dysfunction, possibly through downregulation of endothelial CAV-1 and eNOS.
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Affiliation(s)
- Yousif A Shamsaldeen
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, UK
| | - Rosemary Ugur
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, UK
| | - Christopher D Benham
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, UK
| | - Lisa A Lione
- School of Life and Medical Sciences, University of Hertfordshire, College Lane, UK
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20
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Wu Y, Wang L, Hu K, Yu C, Zhu Y, Zhang S, Shao A. Mechanisms and Therapeutic Targets of Depression After Intracerebral Hemorrhage. Front Psychiatry 2018; 9:682. [PMID: 30618863 PMCID: PMC6304443 DOI: 10.3389/fpsyt.2018.00682] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 11/23/2018] [Indexed: 12/17/2022] Open
Abstract
The relationship between depression and intracerebral hemorrhage (ICH) is complicated. One of the most common neuropsychiatric comorbidities of hemorrhagic stroke is Post-ICH depression. Depression, as a neuropsychiatric symptom, also negatively impacts the outcome of ICH by enhancing morbidity, disability, and mortality. However, the ICH outcome can be improved by antidepressants such as the frequently-used selective serotonin reuptake inhibitors. This review therefore presents the mechanisms of post-ICH depression, we grouped the mechanisms according to inflammation, oxidative stress (OS), apoptosis and autophagy, and explained them through their several associated signaling pathways. Inflammation is mainly related to Toll-like receptors (TLRs), the NF-kB mediated signal pathway, the PPAR-γ-dependent pathway, as well as other signaling pathways. OS is associated to nuclear factor erythroid-2 related factor 2 (Nrf2), the PI3K/Akt pathway and the MAPK/P38 pathway. Moreover, autophagy is associated with the mTOR signaling cascade and the NF-kB mediated signal pathway, while apoptosis is correlated with the death receptor-mediated apoptosis pathway, mitochondrial apoptosis pathway, caspase-independent pathways and others. Furthermore, we found that neuroinflammation, oxidative stress, autophagy, and apoptosis experience interactions with one another. Additionally, it may provide several potential therapeutic targets for patients that might suffer from depression after ICH.
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Affiliation(s)
- Yinan Wu
- Cancer Institute, Key Laboratory of Cancer Prevention and Intervention, China National Ministry of Education, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Liangliang Wang
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China
| | - Kaimin Hu
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chengcheng Yu
- Department of Orthopedics, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuanhan Zhu
- Department of Neurosurgery, Rongjun Hospital, Jiaxing, China
| | - Suzhan Zhang
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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Abstract
Temporal and spatial patterns of pathological changes such as loss of neurons and presence of pathological protein aggregates are characteristic of neurodegenerative diseases such as Amyotrophic Lateral Sclerosis, Frontotemporal Dementia, Alzheimer's disease and Parkinson's disease. These patterns are consistent with the propagation of protein misfolding and aggregation reminiscent of the prion diseases. There is a surge of evidence that suggests that large protein aggregates of a range of proteins are able to enter cells via macropinocytosis. Our recent work suggests that this process is activated by the binding of aggregates to the neuron cell surface. The current review considers the potential role of cell surface receptors in the triggering of macropinocytosis by protein aggregates and the possibility of utilizing macropinocytosis pathways as a therapeutic target.
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Affiliation(s)
- Justin J Yerbury
- a Proteostasis and Disease Research Center, School of Biological Sciences, Faculty of Science, Medicine and Health , University of Wollongong , Wollongong , Australia ; Illawarra Health and Medical Research Institute , Wollongong , Australia
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22
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Luo Y, Duan H, Qian Y, Feng L, Wu Z, Wang F, Feng J, Yang D, Qin Z, Yan X. Macrophagic CD146 promotes foam cell formation and retention during atherosclerosis. Cell Res 2017; 27:352-372. [PMID: 28084332 PMCID: PMC5339843 DOI: 10.1038/cr.2017.8] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 10/18/2016] [Accepted: 11/28/2016] [Indexed: 12/24/2022] Open
Abstract
The persistence of cholesterol-engorged macrophages (foam cells) in the artery wall fuels the development of atherosclerosis. However, the mechanism that regulates the formation of macrophage foam cells and impedes their emigration out of inflamed plaques is still elusive. Here, we report that adhesion receptor CD146 controls the formation of macrophage foam cells and their retention within the plaque during atherosclerosis exacerbation. CD146 is expressed on the macrophages in human and mouse atheroma and can be upregulated by oxidized low-density lipoprotein (oxLDL). CD146 triggers macrophage activation by driving the internalization of scavenger receptor CD36 during lipid uptake. In response to oxLDL, macrophages show reduced migratory capacity toward chemokines CCL19 and CCL21; this capacity can be restored by blocking CD146. Genetic deletion of macrophagic CD146 or targeting of CD146 with an antibody result in much less complex plaques in high-fat diet-fed ApoE-/- mice by causing lipid-loaded macrophages to leave plaques. Collectively, our findings identify CD146 as a novel retention signal that traps macrophages within the artery wall, and a promising therapeutic target in atherosclerosis treatment.
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Affiliation(s)
- Yongting Luo
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Hongxia Duan
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yining Qian
- Beijing Anzhen Hospital of the Capital University of Medical Sciences, Beijing 100029, China
| | - Liqun Feng
- Beijing Anzhen Hospital of the Capital University of Medical Sciences, Beijing 100029, China
| | - Zhenzhen Wu
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Fei Wang
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jing Feng
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Dongling Yang
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhihai Qin
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiyun Yan
- Key Laboratory of Protein and Peptide Pharmaceutical, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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23
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Ma L, Qian L, Ying Q, Zhang Y, Zhou C, Wu G. I 4, a synthetic anti-diabetes agent, attenuates atherosclerosis through its lipid-lowering, anti-inflammatory and anti-apoptosis properties. Mol Cell Endocrinol 2017; 440:80-92. [PMID: 27725191 DOI: 10.1016/j.mce.2016.10.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 09/10/2016] [Accepted: 10/07/2016] [Indexed: 01/12/2023]
Abstract
Here, we investigated whether I4, which was initially developed as a hypoglycemic agent, possesses anti-atherosclerotic activity and attempted to elucidate the probable mechanism of action underlying this activity. ApoE-/- mice were fed a Western diet and simultaneously administered I4, glimepiride, or pioglitazone once daily for 12 weeks, and the atherosclerotic vascular lesions, lipid content, and expression levels of LOX-1, ICAM-1, VCAM-1 and Bax/Bcl-2 in mouse aortas were assessed. RAW264.7 macrophage-derived foam cells were obtained via ox-LDL stimulation to investigate the lipid-lowering, anti-atherosclerotic inflammation and anti-apoptotic effect of I4. The data indicated that I4 significantly decreased the lipid accumulation in the circulation and tissue, especially for TG and FFA levels (p < 0.05 vs model group), alleviating the arterial and liver lesions induced by lipotoxicity. Its lipid-reducing effects may due to LOX-1and CD36 expression suppression. I4, at doses of 20 mg/kg and 10 mg/kg, significantly decreased serum IL-6, IL-1β, and TNF-α production and suppressed the expression of p-ERK, p-p38, VCAM-1 and ICAM-1 protein. I4 attenuated atherosclerotic inflammation by blocking NF-κB nuclear translocation, suppressing MAPK/NF-κB signaling pathway and diminishing NF-κB-VCAM-1 promoter region binding. Additionally, I4 suppressed p-p53 and cleaved-caspase-3 expression to inhibit foam cell apoptosis induced by ox-LDL uptake. Overall, I4 exerts potent inhibitory effects on atherosclerosis onset and development.
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Affiliation(s)
- Lingman Ma
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China
| | - Lifen Qian
- School of Pharmacy, Department of Pharmacology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, China
| | - Qidi Ying
- School of Pharmacy, Department of Pharmacology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, China
| | - Yan Zhang
- School of Pharmacy, Department of Pharmacology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, China
| | - Changlin Zhou
- State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing 210009, China.
| | - Guanzhong Wu
- School of Pharmacy, Department of Pharmacology, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing 210009, China.
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Varshney P, Yadav V, Saini N. Lipid rafts in immune signalling: current progress and future perspective. Immunology 2016; 149:13-24. [PMID: 27153983 DOI: 10.1111/imm.12617] [Citation(s) in RCA: 188] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 04/22/2016] [Accepted: 04/28/2016] [Indexed: 12/15/2022] Open
Abstract
Lipid rafts are dynamic assemblies of proteins and lipids that harbour many receptors and regulatory molecules and so act as a platform for signal transduction. They float freely within the liquid-disordered bilayer of cellular membranes and can cluster to form larger ordered domains. Alterations in lipid rafts are commonly found to be associated with the pathogenesis of several human diseases and recent reports have shown that the raft domains can also be perturbed by targeting raft proteins through microRNAs. Over the last few years, the importance of lipid rafts in modulating both innate and acquired immune responses has been elucidated. Various receptors present on immune cells like B cells, T cells, basophils and mast cells associate with lipid rafts on ligand binding and initiate signalling cascades leading to inflammation. Furthermore, disrupting lipid raft integrity alters lipopolysaccharide-induced cytokine secretion, IgE signalling, and B-cell and T-cell activation. The objective of this review is to summarize the recent progress in understanding the role of lipid rafts in the modulation of immune signalling and its related therapeutic potential for autoimmune diseases and inflammatory disorders.
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Affiliation(s)
- Pallavi Varshney
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India.,Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Vikas Yadav
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
| | - Neeru Saini
- Functional Genomics Unit, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India.,Academy of Scientific & Innovative Research, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), Delhi, India
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25
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Biedroń R, Peruń A, Józefowski S. CD36 Differently Regulates Macrophage Responses to Smooth and Rough Lipopolysaccharide. PLoS One 2016; 11:e0153558. [PMID: 27073833 PMCID: PMC4830570 DOI: 10.1371/journal.pone.0153558] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 03/31/2016] [Indexed: 01/22/2023] Open
Abstract
Lipopolysaccharide (LPS) is the major pathogen-associated molecular pattern of Gram-negative bacterial infections, and includes smooth (S-LPS) and rough (R-LPS) chemotypes. Upon activation by LPS through CD14, TLR4/MD-2 heterodimers sequentially induce two waves of intracellular signaling for macrophage activation: the MyD88-dependent pathway from the plasma membrane and, following internalization, the TRIF-dependent pathway from endosomes. We sought to better define the role of scavenger receptors CD36 and CD204/SR-A as accessory LPS receptors that can contribute to pro-inflammatory and microbicidal activation of macrophages. We have found that CD36 differently regulates activation of mouse macrophages by S-LPS versus R-LPS. The ability of CD36 to substitute for CD14 in loading R-LPS, but not S-LPS onto TLR4/MD-2 allows CD14-independent macrophage responses to R-LPS. Conversely, S-LPS, but not R-LPS effectively stimulates CD14 binding to CD36, which favors S-LPS transfer from CD14 onto TLR4/MD-2 under conditions of low CD14 occupancy with S-LPS in serum-free medium. In contrast, in the presence of serum, CD36 reduces S-LPS binding to TLR4/MD-2 and the subsequent MyD88-dependent signaling, by mediating internalization of S-LPS/CD14 complexes. Additionally, CD36 positively regulates activation of TRIF-dependent signaling by both S-LPS and R-LPS, by promoting TLR4/MD-2 endocytosis. In contrast, we have found that SR-A does not function as a S-LPS receptor. Thus, by co-operating with CD14 in both R- and S-LPS loading onto TLR4/MD-2, CD36 can enhance the sensitivity of tissue-resident macrophages in detecting infections by Gram-negative bacteria. However, in later phases, following influx of serum to the infection site, the CD36-mediated negative regulation of MyD88-dependent branch of S-LPS-induced TLR4 signaling might constitute a mechanism to prevent an excessive inflammatory response, while preserving the adjuvant effect of S-LPS for adaptive immunity.
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Affiliation(s)
- Rafał Biedroń
- Department of Immunology, Jagiellonian University Medical College, Kraków, Poland
| | - Angelika Peruń
- Department of Immunology, Jagiellonian University Medical College, Kraków, Poland
| | - Szczepan Józefowski
- Department of Immunology, Jagiellonian University Medical College, Kraków, Poland
- * E-mail:
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26
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Park YM. Oxidized LDL induces phosphorylation of non-muscle myosin IIA heavy chain in macrophages. BMB Rep 2015; 48:48-53. [PMID: 25322953 PMCID: PMC4345642 DOI: 10.5483/bmbrep.2015.48.1.186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 09/23/2014] [Accepted: 10/16/2014] [Indexed: 11/20/2022] Open
Abstract
Oxidized LDL (oxLDL) performs critical roles in atherosclerosis by inducing macrophage foam cell formation and promoting inflammation. There have been reports showing that oxLDL modulates macrophage cytoskeletal functions for oxLDL uptake and trapping, however, the precise mechanism has not been clearly elucidated. Our study examined the effect of oxLDL on non-muscle myosin heavy chain IIA (MHC-IIA) in macrophages. We demonstrated that oxLDL induces phosphorylation of MHC-IIA (Ser1917) in peritoneal macrophages from wild-type mice and THP-1, a human monocytic cell line, but not in macrophages deficient for CD36, a scavenger receptor for oxLDL. Protein kinase C (PKC) inhibitor-treated macrophages did not undergo the oxLDL-induced MHC-IIA phosphorylation. Our immunoprecipitation revealed that oxLDL increased physical association between PKC and MHC-IIA, supporting the role of PKC in this process. We conclude that oxLDL via CD36 induces PKC-mediated MHC-IIA (Ser1917) phosphorylation and this may affect oxLDL-induced functions of macrophages involved in atherosclerosis.
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Affiliation(s)
- Young Mi Park
- Department of Molecular Medicine, Ewha Womans University School of Medicine; Global Top 5 Research Program, Ewha Womans University, Seoul 158-710, Korea
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27
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Anderson CM, Kazantzis M, Wang J, Venkatraman S, Goncalves RLS, Quinlan CL, Ng R, Jastroch M, Benjamin DI, Nie B, Herber C, Van AAN, Park MJ, Yun D, Chan K, Yu A, Vuong P, Febbraio M, Nomura DK, Napoli JL, Brand MD, Stahl A. Dependence of brown adipose tissue function on CD36-mediated coenzyme Q uptake. Cell Rep 2015; 10:505-15. [PMID: 25620701 DOI: 10.1016/j.celrep.2014.12.048] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/13/2014] [Accepted: 12/19/2014] [Indexed: 02/05/2023] Open
Abstract
Brown adipose tissue (BAT) possesses the inherent ability to dissipate metabolic energy as heat through uncoupled mitochondrial respiration. An essential component of the mitochondrial electron transport chain is coenzyme Q (CoQ). While cells synthesize CoQ mostly endogenously, exogenous supplementation with CoQ has been successful as a therapy for patients with CoQ deficiency. However, which tissues depend on exogenous CoQ uptake as well as the mechanism by which CoQ is taken up by cells and the role of this process in BAT function are not well understood. Here, we report that the scavenger receptor CD36 drives the uptake of CoQ by BAT and is required for normal BAT function. BAT from mice lacking CD36 displays CoQ deficiency, impaired CoQ uptake, hypertrophy, altered lipid metabolism, mitochondrial dysfunction, and defective nonshivering thermogenesis. Together, these data reveal an important new role for the systemic transport of CoQ to BAT and its function in thermogenesis.
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Affiliation(s)
- Courtney M Anderson
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Melissa Kazantzis
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Jinshan Wang
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Subramaniam Venkatraman
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720, USA
| | | | - Casey L Quinlan
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Ryan Ng
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Martin Jastroch
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Daniel I Benjamin
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Biao Nie
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Candice Herber
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - An-Angela Ngoc Van
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Michael J Park
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Dawee Yun
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Karen Chan
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Angela Yu
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Peter Vuong
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Maria Febbraio
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Daniel K Nomura
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Joseph L Napoli
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA
| | - Martin D Brand
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Andreas Stahl
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA 94720, USA.
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28
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Jang S, Ohtani K, Fukuoh A, Mori K, Yoshizaki T, Kitamoto N, Kim Y, Suzuki Y, Wakamiya N. Scavenger receptor CL-P1 mediates endocytosis by associating with AP-2μ2. Biochim Biophys Acta Gen Subj 2014; 1840:3226-37. [DOI: 10.1016/j.bbagen.2014.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 07/27/2014] [Accepted: 07/28/2014] [Indexed: 10/24/2022]
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29
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Rao X, Zhong J, Maiseyeu A, Gopalakrishnan B, Villamena FA, Chen LC, Harkema JR, Sun Q, Rajagopalan S. CD36-dependent 7-ketocholesterol accumulation in macrophages mediates progression of atherosclerosis in response to chronic air pollution exposure. Circ Res 2014; 115:770-780. [PMID: 25186795 DOI: 10.1161/circresaha.115.304666] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE Air pollution exposure has been shown to potentiate plaque progression in humans and animals. Our previous studies have suggested a role for oxidized lipids in mediating adverse vascular effect of air pollution. However, the types of oxidized lipids formed in response to air pollutants and how this occurs and their relevance to atherosclerosis are not fully understood. OBJECTIVE To investigate the mechanisms by which particulate matter <2.5 μm (PM2.5) induces progression of atherosclerosis. METHODS AND RESULTS Atherosclerosis-prone ApoE(-/-) or LDLR(-/-) mice were exposed to filtered air or concentrated ambient PM2.5 using a versatile aerosol concentrator enrichment system for 6 months. PM2.5 increased 7-ketocholesterol (7-KCh), an oxidatively modified form of cholesterol, in plasma intermediate density lipoprotein/low-density lipoprotein fraction and in aortic plaque concomitant with progression of atherosclerosis and increased CD36 expression in plaque macrophages from PM2.5-exposed mice. Macrophages isolated from PM2.5-exposed mice displayed increased uptake of oxidized lipids without alterations in their efflux capacity. Consistent with these finding, CD36-positive macrophages displayed a heightened capacity for oxidized lipid uptake. Deficiency of CD36 on hematopoietic cells diminished the effect of air pollution on 7-KCh accumulation, foam cell formation, and atherosclerosis. CONCLUSIONS Our results suggest a potential role for CD36-mediated abnormal accumulations of oxidized lipids, such as 7-KCh, in air pollution-induced atherosclerosis progression.
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Affiliation(s)
- Xiaoquan Rao
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Jixin Zhong
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Andrei Maiseyeu
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
| | - Bhavani Gopalakrishnan
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Frederick A Villamena
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Lung-Chi Chen
- The Department of Environmental Medicine, New York University School of Medicine, Tuxedo, New York, USA
| | - Jack R Harkema
- Center for Integrative Toxicology and Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA
| | - Qinghua Sun
- Department of Pharmacology, Davis Heart & Lung Research Institute, The Ohio State University, Columbus, Ohio, USA.,College of Public Health, The Ohio State University, Columbus, Ohio, USA
| | - Sanjay Rajagopalan
- Division of Cardiovascular Medicine, University of Maryland Baltimore, Maryland, USA
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30
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Santamaria MH, Chen AY, Chow J, Muñoz DC, Schmid-Schönbein GW. Cleavage and reduced CD36 ectodomain density on heart and spleen macrophages in the spontaneously hypertensive rat. Microvasc Res 2014; 95:131-42. [PMID: 25172177 DOI: 10.1016/j.mvr.2014.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/21/2014] [Accepted: 08/18/2014] [Indexed: 12/23/2022]
Abstract
Metabolic disease is accompanied by a range of cellular defects ("comorbidities") whose origin is uncertain. To investigate this pathophysiological phenomenon we used the Spontaneously Hypertensive Rat (SHR), which besides an elevated arterial blood pressure also has many other comorbidities, including a defective glucose and lipid metabolism. We have shown that this model of metabolic disease has elevated plasma matrix metalloproteinase (MMP) activity, which cleaves the extracellular domain of membrane receptors. We hypothesize here that the increased MMP activity also leads to abnormal cleavage of the scavenger receptor and fatty acid transporter CD36. To test this idea, chronic pharmaceutical MMP inhibition (CGS27023A) of the SHR and its normotensive control, the Wistar Kyoto Rat (WKY), was used to determine if inhibition of MMP activity serves to maintain CD36 receptor density and function. Surface density of CD36 on macrophages from the heart, spleen, and liver was determined in WKY, SHR, CGS-treated WKY (CGS WKY), and CGS-treated SHR (CGS SHR) by immunohistochemistry with an antibody against the CD36 ectodomain. The extracellular CD36 density was lower in SHR heart and spleen macrophages compared to that in the WKY. MMP inhibition by CGS served to restore the reduced CD36 density on SHR cardiac and splanchnic macrophages to levels of the WKY. To examine CD36 function, culture assays with murine macrophages (RAW 264.7) after incubation in fresh WKY or SHR plasma were used to test for adhesion of light-weight donor red blood cell (RBC) by CD36. This form of RBC adhesion to macrophages was reduced after incubation in SHR compared WKY plasma. Analysis of the supernatant macrophage media by Western blot shows a higher level of CD36 extracellular protein fragments following exposure to SHR plasma compared to WKY. MMP inhibition in the SHR plasma compared to untreated plasma, served to increase the RBC adhesion to macrophages and decrease the number of receptor fragments in the macrophage media. In conclusion, these studies bring to light that plasma in the SHR model of metabolic disease has an unchecked MMP degrading activity which causes cleavage of a variety of membrane receptors, including CD36, which attenuates several cellular functions typical for the metabolic disease, including RBC adhesion to the scavenger receptor CD36. In addition to other cell dysfunctions chronic MMP inhibition restores CD36 in the SHR.
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Affiliation(s)
- Marco H Santamaria
- Department of Bioengineering, Jacobs School of Engineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Angela Y Chen
- Department of Bioengineering, Jacobs School of Engineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Jason Chow
- Department of Bioengineering, Jacobs School of Engineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Diana C Muñoz
- Department of Bioengineering, Jacobs School of Engineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093, USA.
| | - Geert W Schmid-Schönbein
- Department of Bioengineering, Jacobs School of Engineering, Institute of Engineering in Medicine, University of California San Diego, La Jolla, CA 92093, USA.
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31
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Protein mediated fatty acid uptake: Synergy between CD36/FAT-facilitated transport and acyl-CoA synthetase-driven metabolism. Arch Biochem Biophys 2014; 546:8-18. [DOI: 10.1016/j.abb.2014.01.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/17/2014] [Accepted: 01/23/2014] [Indexed: 11/21/2022]
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32
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van Oort MM, Drost R, Janβen L, Van Doorn JM, Kerver J, Van der Horst DJ, Luiken JJFP, Rodenburg KCW. Each of the four intracellular cysteines of CD36 is essential for insulin- or AMP-activated protein kinase-induced CD36 translocation. Arch Physiol Biochem 2014; 120:40-9. [PMID: 24377880 DOI: 10.3109/13813455.2013.876049] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Stimulation of cellular fatty acid uptake by induction of insulin signalling or AMP-kinase (AMPK) activation is due to translocation of the fatty acid-transporter CD36 from intracellular stores to the plasma membrane (PM). For investigating the role of the four Cys-residues within CD36's cytoplasmic tails in CD36 translocation, we constructed CHO-cells expressing CD36 mutants in which all four, two, or one of the intracellular Cys were replaced by Ser. Intracellular and PM localization of all mutants was similar to wild-type CD36 (CD36wt). Hence, the four Cys do not regulate sub-cellular CD36 localization. However, in contrast to CD36wt, insulin or AMPK activation failed to induce translocation of any of the mutants, indicating that all four intracellular Cys residues are essential for CD36 translocation. The mechanism of defective translocation of mutant CD36 is unknown, but appears not due to loss of S-palmitoylation of the cytoplasmic tails or to aberrant oligomerization of the mutants.
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Affiliation(s)
- Masja M van Oort
- Division of Endocrinology and Metabolism, Department of Biology and Institute of Biomembranes, Utrecht University , NL-3584 CH Utrecht , The Netherlands and
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33
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Zhou Y, Wang Y, Wang J, Anne Stetler R, Yang QW. Inflammation in intracerebral hemorrhage: from mechanisms to clinical translation. Prog Neurobiol 2013; 115:25-44. [PMID: 24291544 DOI: 10.1016/j.pneurobio.2013.11.003] [Citation(s) in RCA: 451] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 11/15/2013] [Accepted: 11/18/2013] [Indexed: 02/07/2023]
Abstract
Intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and is associated with high mortality and morbidity. Currently, no effective medical treatment is available to improve functional outcomes in patients with ICH. Potential therapies targeting secondary brain injury are arousing a great deal of interest in translational studies. Increasing evidence has shown that inflammation is the key contributor of ICH-induced secondary brain injury. Inflammation progresses in response to various stimuli produced after ICH. Hematoma components initiate inflammatory signaling via activation of microglia, subsequently releasing proinflammatory cytokines and chemokines to attract peripheral inflammatory infiltration. Hemoglobin (Hb), heme, and iron released after red blood cell lysis aggravate ICH-induced inflammatory injury. Danger associated molecular patterns such as high mobility group box 1 protein, released from damaged or dead cells, trigger inflammation in the late stage of ICH. Preclinical studies have identified inflammatory signaling pathways that are involved in microglial activation, leukocyte infiltration, toll-like receptor (TLR) activation, and danger associated molecular pattern regulation in ICH. Recent advances in understanding the pathogenesis of ICH-induced inflammatory injury have facilitated the identification of several novel therapeutic targets for the treatment of ICH. This review summarizes recent progress concerning the mechanisms underlying ICH-induced inflammation. We focus on the inflammatory signaling pathways involved in microglial activation and TLR signaling, and explore potential therapeutic interventions by targeting the removal of hematoma components and inhibition of TLR signaling.
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Affiliation(s)
- Yu Zhou
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Yanchun Wang
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China
| | - Jian Wang
- Department of Anesthesiology/Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - R Anne Stetler
- Center of Cerebrovascular Disease Research, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Qing-Wu Yang
- Department of Neurology, Xinqiao Hospital & The Second Affiliated Hospital, The Third Military Medical University, Chongqing, China.
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Clearance of apoptotic cells by macrophages induces regulatory phenotype and involves stimulation of CD36 and platelet-activating factor receptor. Mediators Inflamm 2013; 2013:950273. [PMID: 24347838 PMCID: PMC3854564 DOI: 10.1155/2013/950273] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 09/14/2013] [Accepted: 10/08/2013] [Indexed: 12/30/2022] Open
Abstract
Phagocytosis of apoptotic cells (efferocytosis) induces macrophage differentiation towards a regulatory phenotype (IL-10high/IL-12p40low). CD36 is involved in the recognition of apoptotic cells (AC), and we have shown that the platelet-activating factor receptor (PAFR) is also involved. Here, we investigated the contribution of PAFR and CD36 to efferocytosis and to the establishment of a regulatory macrophage phenotype. Mice bone marrow-derived macrophages were cocultured with apoptotic thymocytes, and the phagocytic index was determined. Blockage of PAFR with antagonists or CD36 with specific antibodies inhibited the phagocytosis of AC (~70–80%). Using immunoprecipitation and confocal microscopy, we showed that efferocytosis increased the CD36 and PAFR colocalisation in the macrophage plasma membrane; PAFR and CD36 coimmunoprecipitated with flotillin-1, a constitutive lipid raft protein, and disruption of these membrane microdomains by methyl-β-cyclodextrin reduced AC phagocytosis. Efferocytosis induced a pattern of cytokine production, IL-10high/IL-12p40low, that is, characteristic of a regulatory phenotype. LPS potentiated the efferocytosis-induced production of IL-10, and this was prevented by blocking PAFR or CD36. It can be concluded that phagocytosis of apoptotic cells engages CD36 and PAFR, possibly in lipid rafts, and this is required for optimal efferocytosis and the establishment of the macrophage regulatory phenotype.
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35
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Berre S, Gaudin R, Cunha de Alencar B, Desdouits M, Chabaud M, Naffakh N, Rabaza-Gairi M, Gobert FX, Jouve M, Benaroch P. CD36-specific antibodies block release of HIV-1 from infected primary macrophages and its transmission to T cells. ACTA ACUST UNITED AC 2013; 210:2523-38. [PMID: 24145510 PMCID: PMC3832921 DOI: 10.1084/jem.20130566] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
HIV-1-infected macrophages likely represent viral reservoirs, as they accumulate newly formed virions in internal virus-containing compartments (VCCs). However, the nature and biogenesis of VCCs remain poorly defined. We show that upon HIV-1 infection of primary human macrophages, Gag is recruited to preexisting compartments containing the scavenger receptor CD36, which then become VCCs. Silencing of CD36 in HIV-1-infected macrophages decreases the amount of virions released. Strikingly, soluble anti-CD36 antibodies, but not the natural ligands of CD36, inhibit release of virions from HIV-1-infected macrophages and the transmission of virus to CD4(+) T cells. The effect of the antibodies is potent, rapid, and induces the retention of virions within VCCs. Ectopic expression of CD36 in HeLa cells renders them susceptible to the inhibitory effect of the anti-CD36 mAb upon HIV-1 infection. We show that the anti-CD36 mAb inhibits HIV-1 release by clustering newly formed virions at their site of budding, and that signaling via CD36 is not required. Thus, HIV-1 reservoirs in macrophages may be tackled therapeutically using anti-CD36 antibodies to prevent viral dissemination.
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Affiliation(s)
- Stefano Berre
- Institut Curie, Centre de Recherche, F-75248 Paris, France
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36
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Myosin VI and Associated Proteins Are Expressed in Human Macrophages but Do Not Play a Role in Foam Cell Formation in THP-1 Cells. Int J Vasc Med 2013; 2013:516015. [PMID: 23840954 PMCID: PMC3690746 DOI: 10.1155/2013/516015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 04/16/2013] [Accepted: 05/08/2013] [Indexed: 01/02/2023] Open
Abstract
Myosin VI (Myo6) functions in endocytosis in conjunction with binding partners including adaptor protein (AP)-2, disabled 2 (Dab2), and GAIP interacting protein C terminus 1 (GIPC1). This study aimed to investigate the expression and function of Myo6 in macrophages and its possible role in the endocytosis of lipoproteins during the induction of foam cell formation. Expression of Myo6, AP-2 (α2 subunit), and Dab2 in THP-1 macrophages and primary human monocyte-derived macrophages was demonstrated at the mRNA and protein level, but GIPC1 was only detected at the mRNA level. Immunofluorescence showed that Myo6 was distributed similarly to F-actin in both macrophage types. AP-2α2 was found to have a similar subcellular distribution to Myo6 and Dab2 in THP-1 cells. Myo6 was located within membrane ruffles and protrusions of the plasma membrane. These results suggest that in macrophages Myo6 is required for several functions including cell adhesion, cell progression, and macropinocytosis. Low-density lipoprotein (LDL) and oxidised LDL (oxLDL) decreased Myo6 and GIPC1 mRNA expression in THP-1 cells, but uptake of the fluorescence-labelled lipoproteins was unaffected by knockdown of the expression of Myo6 or associated proteins with siRNA. Our findings, therefore, do not support the idea that Myo6 plays a major role in foam cell formation.
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37
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Min KJ, Um HJ, Cho KH, Kwon TK. Curcumin inhibits oxLDL-induced CD36 expression and foam cell formation through the inhibition of p38 MAPK phosphorylation. Food Chem Toxicol 2013; 58:77-85. [PMID: 23603106 DOI: 10.1016/j.fct.2013.04.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Revised: 04/01/2013] [Accepted: 04/02/2013] [Indexed: 12/28/2022]
Abstract
The uptake of oxidized low density lipoprotein (oxLDL) via scavenger receptors transforms macrophages into foam cells, which are a hallmark of atherosclerosis. OxLDL markedly increases the expression of the CD36 scavenger receptor. Here, we investigated whether curcumin modulate CD36 expression in oxLDL-treated RAW 264.7 murine macrophages. Our results showed that curcumin dramatically inhibits CD36 expression and foam cell formation. Furthermore, oxLDL-induced expression and activity of peroxisome proliferator-activated receptor-gamma (PPAR-γ), which is involved in CD36 expression, is also blocked in curcumin-treated cells. OxLDL activates the mitogen-activated protein kinase (MAPK) signaling transduction pathway, and p38 MAPK is associated with oxLDL-induced CD36 and PPAR-γ expression. Overexpression of dominant negative p38 MAPK blocks oxLDL-induced CD36 and PPAR-γ expression. Furthermore, curcumin markedly inhibits p38 MAPK phosphorylation. Taken together, our results suggest that curcumin modulates oxLDL-induced CD36 expression and foam cell formation via the inhibition of p38 MAPK phosphorylation in RAW 264.7 murine macrophages.
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Affiliation(s)
- Kyoung-jin Min
- Department of Immunology, School of Medicine, Keimyung University, 2800 Dalgubeoldaero, Dalseo-Gu, Daegu 704-701, South Korea
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Chakraborty M, Lou C, Huan C, Kuo MS, Park TS, Cao G, Jiang XC. Myeloid cell-specific serine palmitoyltransferase subunit 2 haploinsufficiency reduces murine atherosclerosis. J Clin Invest 2013; 123:1784-97. [PMID: 23549085 DOI: 10.1172/jci60415] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/24/2013] [Indexed: 12/15/2022] Open
Abstract
Serine palmitoyltransferase (SPT) is the first and rate-limiting enzyme of the de novo biosynthetic pathway of sphingomyelin (SM). Both SPT and SM have been implicated in the pathogenesis of atherosclerosis, the development of which is driven by macrophages; however, the role of SPT in macrophage-mediated atherogenesis is unknown. To address this issue, we have analyzed macrophage inflammatory responses and reverse cholesterol transport, 2 key mediators of atherogenesis, in SPT subunit 2-haploinsufficient (Sptlc2(+/-)) macrophages. We found that Sptlc2(+/-) macrophages have significantly lower SM levels in plasma membrane and lipid rafts. This reduction not only impaired inflammatory responses triggered by TLR4 and its downstream NF-κB and MAPK pathways, but also enhanced reverse cholesterol transport mediated by ABC transporters. LDL receptor-deficient (Ldlr(-/-)) mice transplanted with Sptlc2(+/-) bone marrow cells exhibited significantly fewer atherosclerotic lesions after high-fat and high-cholesterol diet feeding. Additionally, Ldlr(-/-) mice with myeloid cell-specific Sptlc2 haploinsufficiency exhibited significantly less atherosclerosis than controls. These findings suggest that SPT could be a novel therapeutic target in atherosclerosis.
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Affiliation(s)
- Mahua Chakraborty
- Department of Cell Biology, State University of New York Downstate Medical Center, New York, New York, USA
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Roberts K, Zeineddine R, Corcoran L, Li W, Campbell IL, Yerbury JJ. Extracellular aggregated Cu/Zn superoxide dismutase activates microglia to give a cytotoxic phenotype. Glia 2012; 61:409-19. [PMID: 23281114 DOI: 10.1002/glia.22444] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 10/24/2012] [Indexed: 02/04/2023]
Abstract
A large body of literature suggests that amyotrophic lateral sclerosis (ALS) pathology is intimately linked with neuroinflammation, specifically activation and recruitment of microglia and astrocytes. The actual cause of gliosis is unclear. Extracellular Cu/Zn superoxide dismutase (SOD1) has recently been shown to activate microglia in a CD14 dependant mechanism providing one potential pathway by which glial cells become activated. As protein inclusions are thought to be an important part of ALS pathology and are associated with all forms of ALS, we sought to determine if aggregated SOD1 would activate microglia. Recombinant SOD1 was aggregated and this, or monomeric forms of SOD1 were then added to EOC.13 microglial cells or primary microglial cells in culture. Although monomeric mutant SOD1 has been shown to promote microglial activation in the past, we found that aggregated SOD1 was able to much more efficiently activate microglia in culture when compared with the unaggregated form of mutant SOD1. In addition to CD14 dependant pathways, aggregated SOD1 also bound to the surface of glial cells and was internalized in a lipid raft and scavenger receptor dependent manner. We have for the first time shown that aggregated mutant SOD1 potently activates microglia. These results suggest that there may be a potential link between protein aggregation and microglial activation in ALS.
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Affiliation(s)
- Kate Roberts
- School of Biological Sciences, Faculty of Science, University of Wollongong, New South Wales, Australia
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Davies BSJ, Goulbourne CN, Barnes RH, Turlo KA, Gin P, Vaughan S, Vaux DJ, Bensadoun A, Beigneux AP, Fong LG, Young SG. Assessing mechanisms of GPIHBP1 and lipoprotein lipase movement across endothelial cells. J Lipid Res 2012; 53:2690-7. [PMID: 23008484 DOI: 10.1194/jlr.m031559] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipoprotein lipase (LPL) is secreted into the interstitial spaces by adipocytes and myocytes but then must be transported to the capillary lumen by GPIHBP1, a glycosylphosphatidylinositol-anchored protein of capillary endothelial cells. The mechanism by which GPIHBP1 and LPL move across endothelial cells remains unclear. We asked whether the transport of GPIHBP1 and LPL across endothelial cells was uni- or bidirectional. We also asked whether GPIHBP1 and LPL are transported across cells in vesicles and whether this transport process requires caveolin-1. The movement of GPIHBP1 and LPL across cultured endothelial cells was bidirectional. Also, GPIHBP1 moved bidirectionally across capillary endothelial cells in live mice. The transport of LPL across endothelial cells was inhibited by dynasore and genistein, consistent with a vesicular transport process. Also, transmission electron microscopy (EM) and dual-axis EM tomography revealed GPIHBP1 and LPL in invaginations of the plasma membrane and in vesicles. The movement of GPIHBP1 across capillary endothelial cells was efficient in the absence of caveolin-1, and there was no defect in the internalization of LPL by caveolin-1-deficient endothelial cells in culture. Our studies show that GPIHBP1 and LPL move bidirectionally across endothelial cells in vesicles and that transport is efficient even when caveolin-1 is absent.
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Affiliation(s)
- Brandon S J Davies
- Department of Medicine, University of California, Los Angeles, CA 90095, USA.
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41
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Matarazzo S, Quitadamo MC, Mango R, Ciccone S, Novelli G, Biocca S. Cholesterol-lowering drugs inhibit lectin-like oxidized low-density lipoprotein-1 receptor function by membrane raft disruption. Mol Pharmacol 2012; 82:246-54. [PMID: 22570368 DOI: 10.1124/mol.112.078915] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Lectin-like oxidized low-density lipoprotein (LOX-1), the primary receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, is up-regulated in atherosclerotic lesions. Statins are the principal therapeutic agents for cardiovascular diseases and are known to down-regulate LOX-1 expression. Whether the effect on the LOX-1 receptor is related to statin-mediated cholesterol-lowering activity is unknown. We investigate the requirement of cholesterol for LOX-1-mediated lipid particle internalization, trafficking, and processing and the role of statins as inhibitors of LOX-1 function. Disruption of cholesterol-rich membrane microdomains by acute exposure of cells to methyl-β-cyclodextrin or chronic exposure to different statins (lovastatin and atorvastatin) led to a spatial disorganization of LOX-1 in plasma membranes and a marked loss of specific LOX-1 function in terms of ox-LDL binding and internalization. Subcellular fractionation and immunochemical studies indicate that LOX-1 is naturally present in caveolae-enriched lipid rafts and, by cholesterol reduction, the amount of LOX-1 in this fraction is highly decreased (≥60%). In contrast, isoprenylation inhibition had no effect on the distribution and function of LOX-1 receptors. Furthermore, in primary cultures from atherosclerotic human aorta lesions, we confirm the presence of LOX-1 in caveolae-enriched lipid rafts and demonstrate that lovastatin treatment led to down-regulation of LOX-1 in lipid rafts and rescue of the ox-LDL-induced apoptotic phenotype. Taken together, our data reveal a previously unrecognized essential role of membrane cholesterol for LOX-1 receptor activity and suggest that statins protect vascular endothelium against the adverse effect of ox-LDL by disruption of membrane rafts and impairment of LOX-1 receptor function.
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Affiliation(s)
- Sara Matarazzo
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, Rome, Italy
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42
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Sato M, Hutchinson DS, Halls ML, Furness SGB, Bengtsson T, Evans BA, Summers RJ. Interaction with caveolin-1 modulates G protein coupling of mouse β3-adrenoceptor. J Biol Chem 2012; 287:20674-88. [PMID: 22535965 DOI: 10.1074/jbc.m111.280651] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Caveolins act as scaffold proteins in multiprotein complexes and have been implicated in signaling by G protein-coupled receptors. Studies using knock-out mice suggest that β(3)-adrenoceptor (β(3)-AR) signaling is dependent on caveolin-1; however, it is not known whether caveolin-1 is associated with the β(3)-AR or solely with downstream signaling proteins. We have addressed this question by examining the impact of membrane rafts and caveolin-1 on the differential signaling of mouse β(3a)- and β(3b)-AR isoforms that diverge at the distal C terminus. Only the β(3b)-AR promotes pertussis toxin (PTX)-sensitive cAMP accumulation. When cells expressing the β(3a)-AR were treated with filipin III to disrupt membrane rafts or transfected with caveolin-1 siRNA, the cyclic AMP response to the β(3)-AR agonist CL316243 became PTX-sensitive, suggesting Gα(i/o) coupling. The β(3a)-AR C terminus, SP(384)PLNRF(389)DGY(392)EGARPF(398)PT, resembles a caveolin interaction motif. Mutant β(3a)-ARs (F389A/Y392A/F398A or P384S/F389A) promoted PTX-sensitive cAMP responses, and in situ proximity assays demonstrated an association between caveolin-1 and the wild type β(3a)-AR but not the mutant receptors. In membrane preparations, the β(3b)-AR activated Gα(o) and mediated PTX-sensitive cAMP responses, whereas the β(3a)-AR did not activate Gα(i/o) proteins. The endogenous β(3a)-AR displayed Gα(i/o) coupling in brown adipocytes from caveolin-1 knock-out mice or in wild type adipocytes treated with filipin III. Our studies indicate that interaction of the β(3a)-AR with caveolin inhibits coupling to Gα(i/o) proteins and suggest that signaling is modulated by a raft-enriched complex containing the β(3a)-AR, caveolin-1, Gα(s), and adenylyl cyclase.
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Affiliation(s)
- Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and the Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia
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De Cicco NNT, Pereira MG, Corrêa JR, Andrade-Neto VV, Saraiva FB, Chagas-Lima AC, Gondim KC, Torres-Santos EC, Folly E, Saraiva EM, Cunha-E-Silva NL, Soares MJ, Atella GC. LDL uptake by Leishmania amazonensis: involvement of membrane lipid microdomains. Exp Parasitol 2012; 130:330-40. [PMID: 22381219 DOI: 10.1016/j.exppara.2012.02.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 02/10/2012] [Accepted: 02/13/2012] [Indexed: 02/02/2023]
Abstract
Leishmania amazonensis lacks a de novo mechanism for cholesterol synthesis and therefore must scavenge this lipid from the host environment. In this study we show that the L. amazonensis takes up and metabolizes human LDL(1) particles in both a time and dose-dependent manner. This mechanism implies the presence of a true LDL receptor because the uptake is blocked by both low temperature and by the excess of non-labelled LDL. This receptor is probably associated with specific microdomains in the membrane of the parasite, such as rafts, because this process is blocked by methyl-β-cyclodextrin (MCBD). Cholesteryl ester fluorescently-labeled LDL (BODIPY-cholesteryl-LDL) was used to follow the intracellular distribution of this lipid. After uptake it was localized in large compartments along the parasite body. The accumulation of LDL was analyzed by flow cytometry using FITC-labeled LDL particles. Together these data show for the first time that L. amazonensis is able to compensate for its lack of lipid synthesis through the use of a lipid importing machinery largely based on the uptake of LDL particles from the host. Understanding the details of the molecular events involved in this mechanism may lead to the identification of novel targets to block Leishmania infection in human hosts.
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Affiliation(s)
- Nuccia N T De Cicco
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21.941-902, Brazil
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Shu G, Liao WY, Feng JY, Yu KF, Zhai YF, Wang SB, Khondowe P, Wang XQ, Jiang QY. Active immunization of fatty acid translocase specifically decreased visceral fat deposition in male broilers. Poult Sci 2011; 90:2557-64. [PMID: 22010241 DOI: 10.3382/ps.2010-01238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipid accumulation of avian adipocytes is mainly dependent upon the fatty acid transmembrane uptake process mediated by membrane proteins, such as fatty acid translocase (FAT/CD36), fatty acid transport protein 1, and caveolin-2. To examine the effects of FAT/CD36 on spatial-specific fat deposition, 60 broiler chickens were randomly allocated to 2 groups by sex. Each male or female group contained 2 subgroups (n = 14-15) inoculated by intramuscular injection with chicken FAT/CD36 or BSA (control) immunogens at 34, 49, and 63 d. The subcutaneous and visceral fat deposits were measured, as were levels of plasma triglyceride and free fatty acid. Serum antibody titer was measured by ELISA. The mRNA expression levels of fatty acid transport-related genes in the adipose tissue of the male broilers were investigated to reveal the relationships among various fatty acid transporters. The results showed that active immunization with FAT/CD36 could significantly decrease the visceral fat of the male broilers by up to 40%, but it had no effect on subcutaneous fat stores of male broilers or on either site of fat deposition in female broilers. The concentration of plasma free fatty acids increased in the experimental groups for both male and female broilers. After the FAT/CD36 immunization, very low density lipoprotein receptor mRNA expression was upregulated in both the subcutaneous and visceral fat of male broilers, whereas peroxisome proliferator-activated receptor γ, FAT/CD36, and acyl-CoA binding protein mRNA expression levels were upregulated only in the visceral fat of male broilers. These results indicated a novel role of chicken FAT/CD36 in fat deposition, with sex- and spatial-specific effects.
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Affiliation(s)
- G Shu
- College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China
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Jaqaman K, Kuwata H, Touret N, Collins R, Trimble WS, Danuser G, Grinstein S. Cytoskeletal control of CD36 diffusion promotes its receptor and signaling function. Cell 2011; 146:593-606. [PMID: 21854984 DOI: 10.1016/j.cell.2011.06.049] [Citation(s) in RCA: 185] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 04/28/2011] [Accepted: 06/21/2011] [Indexed: 01/21/2023]
Abstract
The mechanisms that govern receptor coalescence into functional clusters--often a critical step in their stimulation by ligand--are poorly understood. We used single-molecule tracking to investigate the dynamics of CD36, a clustering-responsive receptor that mediates oxidized LDL uptake by macrophages. We found that CD36 motion in the membrane was spatially structured by the cortical cytoskeleton. A subpopulation of receptors diffused within linear confinement regions whose unique geometry simultaneously facilitated freedom of movement along one axis while increasing the effective receptor density. Co-confinement within troughs enhanced the probability of collisions between unligated receptors and promoted their clustering. Cytoskeleton perturbations that inhibited diffusion in linear confinement regions reduced receptor clustering in the absence of ligand and, following ligand addition, suppressed CD36-mediated signaling and internalization. These observations demonstrate a role for the cytoskeleton in controlling signal transduction by structuring receptor diffusion within membrane regions that increase their collision frequency.
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Affiliation(s)
- Khuloud Jaqaman
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
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Priming of the vascular endothelial growth factor signaling pathway by thrombospondin-1, CD36, and spleen tyrosine kinase. Blood 2011; 117:4658-66. [PMID: 21378271 DOI: 10.1182/blood-2010-09-305284] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
CD36 plays a critical role in the inhibition of angiogenesis through binding to the type 1 repeats of thrombospondin-1 (TSP-1) and activating Fyn tyrosine kinase and MAPK pathways. Here, we reveal a novel association of CD36 with VEGFR-2 and spleen tyrosine kinase (Syk). We also address the correlation between the expression of CD36 and Syk by demonstrating that overexpression of CD36 in HUVECs up-regulates endogenous Syk expression. We also define a new role for TSP-1 and CD36 in the activation of the VEGFR-2 signaling pathway that requires Syk. Our findings also identify a role for Syk as a stimulator of VEGF-A-induced angiogenesis by increasing phosphorylation of Y1175 in VEGFR-2, which is a major tyrosine for promoting VEGF-A-induced endothelial cell migration. Together, these studies introduce a new signaling pathway for TSP-1, CD36, and Syk, and address the role of these proteins in regulating the angiogenic switch.
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Involvement of cholesterol-enriched microdomains in class A scavenger receptor-mediated responses in human macrophages. Atherosclerosis 2011; 215:60-9. [DOI: 10.1016/j.atherosclerosis.2010.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Revised: 09/09/2010] [Accepted: 10/13/2010] [Indexed: 11/20/2022]
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Impact of oxLDL on Cholesterol-Rich Membrane Rafts. J Lipids 2011; 2011:730209. [PMID: 21490811 PMCID: PMC3066652 DOI: 10.1155/2011/730209] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 11/29/2010] [Indexed: 11/26/2022] Open
Abstract
Numerous studies have demonstrated that cholesterol-rich membrane rafts play critical roles in multiple cellular functions. However, the impact of the lipoproteins on the structure, integrity and cholesterol composition of these domains is not well understood. This paper focuses on oxidized low-density lipoproteins (oxLDLs) that are strongly implicated in the development of the cardiovascular disease and whose impact on membrane cholesterol and on membrane rafts has been highly controversial. More specifically, we discuss three major criteria for the impact of oxLDL on membrane rafts: distribution of different membrane raft markers, changes in membrane cholesterol composition, and changes in lipid packing of different membrane domains. We also propose a model to reconcile the controversy regarding the relationship between oxLDL, membrane cholesterol, and the integrity of cholesterol-rich membrane domains.
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Li R, Oteiza A, Sørensen KK, McCourt P, Olsen R, Smedsrød B, Svistounov D. Role of liver sinusoidal endothelial cells and stabilins in elimination of oxidized low-density lipoproteins. Am J Physiol Gastrointest Liver Physiol 2011; 300:G71-81. [PMID: 21030611 PMCID: PMC3025507 DOI: 10.1152/ajpgi.00215.2010] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Atherogenesis is associated with elevated levels of low-density lipoprotein (LDL) and its oxidized form (oxLDL) in the blood. The liver is an important scavenger organ for circulating oxLDLs. The present study aimed to examine endocytosis of mildly oxLDL (the major circulating form of oxLDLs) in liver sinusoidal endothelial cells (LSECs) and the involvement of the scavenger receptors stabilin-1 and stabilin-2 in this process. Freshly isolated LSECs, Kupffer cells (KCs), and stabilin-1- and stabilin-2-transfected human embryonic kidney cells were incubated with fluorescently labeled or radiolabeled oxLDLs [oxidized for 3 h (oxLDL(3)), 6 h, or 24 h (oxLDL(24))] to measure endocytosis. The intracellular localization of oxLDLs and stabilins in LSECs was examined by immunofluorescence and immunogold electron microscopy. Whereas oxLDL(24) was endocytosed both by LSECs and KCs, oxLDL(3) (mildly oxLDL) was taken up by LSECs only. The LSEC uptake of oxLDLs was significantly inhibited by the scavenger receptor ligand formaldehyde-treated serum albumin. Uptake of all modified LDLs was high in stabilin-1-transfected cells, whereas stabilin-2-transfected cells preferentially took up oxLDL(24), suggesting that stabilin-1 is a more important receptor for mildly oxLDLs than stabilin-2. Double immunogold labeling experiments in LSECs indicated interactions of stabilin-1 and stabilin-2 with oxLDL(3) on the cell surface, in coated pits, and endocytic vesicles. LSECs but not KCs endocytosed mildly oxLDL. Both stabilin-1 and stabilin-2 were involved in the LSEC endocytosis of oxLDLs, but experiments with stabilin-transfected cells pointed to stabilin-1 as the most important receptor for mildly oxLDL.
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Affiliation(s)
- Ruomei Li
- Faculty of Health Sciences, 1Vascular Biology Research Group and
| | - Ana Oteiza
- Faculty of Health Sciences, 1Vascular Biology Research Group and
| | | | - Peter McCourt
- Faculty of Health Sciences, 1Vascular Biology Research Group and
| | - Randi Olsen
- 2Department of Electron Microscopy, Institute of Medical Biology, University of Tromsø, Tromsø, Norway
| | - Bård Smedsrød
- Faculty of Health Sciences, 1Vascular Biology Research Group and
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Stephen SL, Freestone K, Dunn S, Twigg MW, Homer-Vanniasinkam S, Walker JH, Wheatcroft SB, Ponnambalam S. Scavenger receptors and their potential as therapeutic targets in the treatment of cardiovascular disease. Int J Hypertens 2010; 2010:646929. [PMID: 20981357 PMCID: PMC2958427 DOI: 10.4061/2010/646929] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 07/07/2010] [Indexed: 12/12/2022] Open
Abstract
Scavenger receptors act as membrane-bound and soluble proteins that bind to macromolecular complexes and pathogens. This diverse supergroup of proteins mediates binding to modified lipoprotein particles which regulate the initiation and progression of atherosclerotic plaques. In vascular tissues, scavenger receptors are implicated in regulating intracellular signaling, lipid accumulation, foam cell development, and cellular apoptosis or necrosis linked to the pathophysiology of atherosclerosis. One approach is using gene therapy to modulate scavenger receptor function in atherosclerosis. Ectopic expression of membrane-bound scavenger receptors using viral vectors can modify lipid profiles and reduce the incidence of atherosclerosis. Alternatively, expression of soluble scavenger receptors can also block plaque initiation and progression. Inhibition of scavenger receptor expression using a combined gene therapy and RNA interference strategy also holds promise for long-term therapy. Here we review our current understanding of the gene delivery by viral vectors to cells and tissues in gene therapy strategies and its application to the modulation of scavenger receptor function in atherosclerosis.
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Affiliation(s)
- Sam L Stephen
- Endothelial Cell Biology Unit, Institute of Molecular & Cellular Biology, LIGHT Laboratories, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK
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