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Llorens-Cebrià C, Núñez-Seral N, Villena-Ortiz Y, Martínez-Díaz I, Soler MJ, Ferrer-Costa R, Jacobs-Cachá C, López-Hellín J. Trypsin Partially Cleaves Apolipoprotein A-I (ApoA-I) Precursor into Mature ApoA-I Hindering the Quantification of Naturally Occurring ApoA-I Proteoforms by Liquid Chromatography in Multiple Reaction Monitoring Mode Mass Spectrometry (LC-MRM-MS). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:2267-2271. [PMID: 39304183 PMCID: PMC11450815 DOI: 10.1021/jasms.4c00155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 09/04/2024] [Accepted: 09/06/2024] [Indexed: 09/22/2024]
Abstract
Apolipoprotein A-I (ApoA-I), one of the most abundant proteins in plasma and the major protein component of high-density lipoprotein (HDL), is naturally found in several proteoforms; two of them are ProApoA-I and mature ApoA-I. These two proteoforms of ApoA-I coexist in biological samples and differ only in their N-terminal end. Virtually, the only way to differentiate them is by detecting the proteoform-specific N-terminal proteolytic peptides (RHFWQQDEPPQSPWDR and DEPPQSPWDR, respectively) using liquid chromatography in multiple reaction monitoring mode mass spectrometry (LC-MRM-MS). We have developed a bottom-up LC-MRM-MS method to simultaneously detect proApoA-I and mature ApoA-I. To test the specificity of the method, we digested with trypsin purified mature ApoA-I and recombinant proApoA-I. As expected, only the N-term peptide corresponding to the mature ApoA-I proteoform (DEPPQSPWDR) was detected when digesting mature ApoA-I. However, the digestion of the proApoA-I produced not only the N-terminal peptide corresponding to proApoA-I (RHFWQQDEPPQSPWDR) but also the N-terminal tryptic peptide corresponding to mature ApoA-I (DEPPQSPWDR). This effect was produced by standard and high-specificity trypsin as well as by the Arg-C enzyme in a self-limited manner (approximately 10% of the total). The synthetic proApo-I peptide is not cleaved by trypsin, suggesting that the here reported effect is dependent on protein conformation. The effect is not negligible, as it can be detected by LC-MRM-MS, and correction calculations should be applied to accurately quantify proApoA-I and mature ApoA-I in biological samples where these two proteoforms may coexist.
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Affiliation(s)
- Carmen Llorens-Cebrià
- Nephrology
and Transplantation Research Group, Vall
d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Norberto Núñez-Seral
- High
Technology Unit. Vall d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Yolanda Villena-Ortiz
- Clinical
Biochemistry Department. Vall d’Hebron University Hospital.
Clinical Biochemistry, drug delivery and therapy Research Group, Vall d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Irene Martínez-Díaz
- Nephrology
and Transplantation Research Group, Vall
d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Maria José Soler
- Nephrology
and Transplantation Research Group, Vall
d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Roser Ferrer-Costa
- Clinical
Biochemistry Department. Vall d’Hebron University Hospital.
Clinical Biochemistry, drug delivery and therapy Research Group, Vall d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Conxita Jacobs-Cachá
- Clinical
Biochemistry Department. Vall d’Hebron University Hospital.
Clinical Biochemistry, drug delivery and therapy Research Group, Vall d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
| | - Joan López-Hellín
- Clinical
Biochemistry Department. Vall d’Hebron University Hospital.
Clinical Biochemistry, drug delivery and therapy Research Group, Vall d’Hebrón Research Institute (VHIR), Vall d’Hebron Barcelona Hospital
Campus, 08035 Barcelona, Spain
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2
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Takahashi G, Hoshikawa K, Suzuki R, Sato K, Hoshi S, Yoshinao D, Shirakawa K. Development of a newly immunoassay specific for mouse presepsin (sCD14-ST). Sci Rep 2022; 12:21724. [PMID: 36522357 PMCID: PMC9755121 DOI: 10.1038/s41598-022-22096-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 10/10/2022] [Indexed: 12/23/2022] Open
Abstract
Presepsin (sCD14-ST) is used as a marker for sepsis diagnosis. The production mechanism of presepsin is unique in that it is produced through phagocytosis of microorganisms. However, some studies have demonstrated that non-infected patients had increased presepsin levels and that presepsin is related to the risk or severity of diseases. This study was designed to describe a sensitive sandwich enzyme-linked immunosorbent assay for mouse presepsin developed to investigate the association of presepsin with diseases. Polyclonal antibodies were generated from peptide-immunized rabbit antiserum. Mouse presepsin standard was prepared using the recombinant method as an Fc-fusion protein. The linear detection range of the method was 4.7-300 pg/mL with a detection limit of 1.4 pg/mL. The assay detected mouse presepsin where mouse soluble CD14 (sCD14) was digested by cathepsin D proteinase and the cross-reactivity of sCD14 was not observed. The normal levels of mouse presepsin and sCD14 were compared; 65.9 ± 21.4 pg/mL and 43.2 ± 7.2 ng/mL were determined, respectively. Moreover, the levels of presepsin and sCD14 were compared with a lipopolysaccharide (LPS)-injected sepsis mouse model. The newly developed analytical method had high specificity to presepsin and is an efficient tool for studying the association between presepsin and diseases.
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Affiliation(s)
- Gaku Takahashi
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Kouichi Hoshikawa
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Rioto Suzuki
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Kotaro Sato
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Shintaro Hoshi
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Daisuke Yoshinao
- grid.411790.a0000 0000 9613 6383Department of Critical Care, Disaster and General Medicine, School of Medicine, Iwate Medical University, 2-1-1 Idaidori Yahaba Town, Iwate, 028-3695 Japan
| | - Kamon Shirakawa
- Clinical Development Group, LSI Medience Corporation, Tokyo, Japan
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Chymase as a Possible Therapeutic Target for Amelioration of Non-Alcoholic Steatohepatitis. Int J Mol Sci 2020; 21:ijms21207543. [PMID: 33066113 PMCID: PMC7589185 DOI: 10.3390/ijms21207543] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/09/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
The development and progression of non-alcoholic steatohepatitis (NASH) are linked to oxidative stress, inflammation, and fibrosis of the liver. Chymase, a chymotrypsin-like enzyme produced in mast cells, has various enzymatic actions. These actions include activation of angiotensin II, matrix metalloproteinase (MMP)-9, and transforming growth factor (TGF)-β, which are associated with oxidative stress, inflammation, and fibrosis, respectively. Augmentation of chymase activity in the liver has been reported in various NASH models. Generation of hepatic angiotensin II and related oxidative stress is upregulated in NASH but attenuated by treatment with a chymase inhibitor. Additionally, increases in MMP-9 and accumulation of inflammatory cells are observed in NASH but are decreased by chymase inhibitor administration. TGF-β and collagen I upregulation in NASH is also attenuated by chymase inhibition. These results in experimental NASH models demonstrate that a chymase inhibitor can effectively ameliorate NASH via the reduction of oxidative stress, inflammation, and fibrosis. Thus, chymase may be a therapeutic target for amelioration of NASH.
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4
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Inoue Y, Okamoto T, Honda T, Nukui Y, Akashi T, Takemura T, Tozuka M, Miyazaki Y. Disruption in the balance between apolipoprotein A-I and mast cell chymase in chronic hypersensitivity pneumonitis. IMMUNITY INFLAMMATION AND DISEASE 2020; 8:659-671. [PMID: 33016012 PMCID: PMC7654418 DOI: 10.1002/iid3.355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
Background Apolipoprotein A‐I (apoA‐I) has an antifibrotic effect in idiopathic pulmonary fibrosis. Although pulmonary fibrosis is associated with poor prognosis of patients with hypersensitivity pneumonitis (HP), little is known regarding the role of apoA‐I in the pathogenesis of HP. Methods Two‐dimensional electrophoresis, immunoblotting, and enzyme‐linked immunosorbent assays were performed for the identification and quantification of apoA‐I in bronchoalveolar lavage fluid (BALF) from patients with acute and chronic HP. To investigate the degradation of apoA‐I, apoA‐I was incubated with BALF. Moreover, the role of apoA‐I in TGF‐β1‐induced epithelial–mesenchymal transition of A549 cells was examined. Results The concentration of apoA‐I in the BALF was significantly lower in chronic HP (n = 56) compared with acute HP (n = 31). The expression level of apoA‐I was also low in the lung tissues of chronic HP. ApoA‐I was degraded by BALF from HP patients. The number of chymase‐positive mast cells in the alveolar parenchyma was inversely correlated with apoA‐I levels in the BALF of chronic HP patients. In vitro experiment using A549 cells, untreated apoA‐I inhibited TGF‐β1‐induced epithelial–mesenchymal transition, although this trend was not observed in the chymase‐treated apoA‐I. Conclusions A decrease of apoA‐I was associated with the pathogenesis of chronic HP in terms of pulmonary fibrosis and mast cell chymase attenuated the protective effect of apoA‐I against pulmonary fibrosis. Furthermore, apoA‐I could be a crucial molecule associated with lung fibrogenesis of HP.
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Affiliation(s)
- Yukihisa Inoue
- Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tsukasa Okamoto
- Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takayuki Honda
- Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshihisa Nukui
- Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Takumi Akashi
- Department of Pathology, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tamiko Takemura
- Department of Pathology, Japan Red Cross Centre, Tokyo, Japan
| | - Minoru Tozuka
- Department of Analytical Laboratory Chemistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yasunari Miyazaki
- Department of Respiratory Medicine, Tokyo Medical and Dental University, Tokyo, Japan
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5
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Soppert J, Lehrke M, Marx N, Jankowski J, Noels H. Lipoproteins and lipids in cardiovascular disease: from mechanistic insights to therapeutic targeting. Adv Drug Deliv Rev 2020; 159:4-33. [PMID: 32730849 DOI: 10.1016/j.addr.2020.07.019] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/12/2022]
Abstract
With cardiovascular disease being the leading cause of morbidity and mortality worldwide, effective and cost-efficient therapies to reduce cardiovascular risk are highly needed. Lipids and lipoprotein particles crucially contribute to atherosclerosis as underlying pathology of cardiovascular disease and influence inflammatory processes as well as function of leukocytes, vascular and cardiac cells, thereby impacting on vessels and heart. Statins form the first-line therapy with the aim to block cholesterol synthesis, but additional lipid-lowering drugs are sometimes needed to achieve low-density lipoprotein (LDL) cholesterol target values. Furthermore, beyond LDL cholesterol, also other lipid mediators contribute to cardiovascular risk. This review comprehensively discusses low- and high-density lipoprotein cholesterol, lipoprotein (a), triglycerides as well as fatty acids and derivatives in the context of cardiovascular disease, providing mechanistic insights into their role in pathological processes impacting on cardiovascular disease. Also, an overview of applied as well as emerging therapeutic strategies to reduce lipid-induced cardiovascular burden is provided.
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Affiliation(s)
- Josefin Soppert
- Institute for Molecular Cardiovascular Research (IMCAR), University Hospital Aachen, Aachen, Germany
| | - Michael Lehrke
- Medical Clinic I, University Hospital Aachen, Aachen, Germany
| | - Nikolaus Marx
- Medical Clinic I, University Hospital Aachen, Aachen, Germany
| | - Joachim Jankowski
- Institute for Molecular Cardiovascular Research (IMCAR), University Hospital Aachen, Aachen, Germany; Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, Maastricht University, the Netherlands
| | - Heidi Noels
- Institute for Molecular Cardiovascular Research (IMCAR), University Hospital Aachen, Aachen, Germany; Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands.
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6
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Apolipoprotein A-I proteolysis in aortic valve stenosis: role of cathepsin S. Basic Res Cardiol 2018; 113:30. [DOI: 10.1007/s00395-018-0689-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/26/2018] [Accepted: 06/12/2018] [Indexed: 01/11/2023]
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7
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Kareinen I, Baumann M, Nguyen SD, Maaninka K, Anisimov A, Tozuka M, Jauhiainen M, Lee-Rueckert M, Kovanen PT. Chymase released from hypoxia-activated cardiac mast cells cleaves human apoA-I at Tyr 192 and compromises its cardioprotective activity. J Lipid Res 2018; 59:945-957. [PMID: 29581158 DOI: 10.1194/jlr.m077503] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 03/22/2018] [Indexed: 01/05/2023] Open
Abstract
ApoA-I, the main structural and functional protein of HDL particles, is cardioprotective, but also highly sensitive to proteolytic cleavage. Here, we investigated the effect of cardiac mast cell activation and ensuing chymase secretion on apoA-I degradation using isolated rat hearts in the Langendorff perfusion system. Cardiac mast cells were activated by injection of compound 48/80 into the coronary circulation or by low-flow myocardial ischemia, after which lipid-free apoA-I was injected and collected in the coronary effluent for cleavage analysis. Mast cell activation by 48/80 resulted in apoA-I cleavage at sites Tyr192 and Phe229, but hypoxic activation at Tyr192 only. In vitro, the proteolytic end-product of apoA-I with either rat or human chymase was the Tyr192-truncated fragment. This fragment, when compared with intact apoA-I, showed reduced ability to promote migration of cultured human coronary artery endothelial cells in a wound-healing assay. We propose that C-terminal truncation of apoA-I by chymase released from cardiac mast cells during ischemia impairs the ability of apoA-I to heal damaged endothelium in the ischemic myocardium.
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Affiliation(s)
- Ilona Kareinen
- Wihuri Research Institute, Helsinki, Finland; Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Marc Baumann
- Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki, Finland
| | | | | | - Andrey Anisimov
- Wihuri Research Institute, Helsinki, Finland; Translational Cancer Biology Program, University of Helsinki, Helsinki, Finland
| | - Minoru Tozuka
- Analytical Laboratory Chemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Matti Jauhiainen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland; National Institute for Health and Welfare, Helsinki, Finland
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8
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Wittenberg M, Nassiri M, Francuzik W, Lehmann K, Babina M, Worm M. Serum levels of 9α,11β-PGF 2 and apolipoprotein A1 achieve high predictive power as biomarkers of anaphylaxis. Allergy 2017; 72:1801-1805. [PMID: 28378321 DOI: 10.1111/all.13176] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2017] [Indexed: 02/02/2023]
Abstract
Anaphylaxis is a life-threatening hypersensitivity reaction. To identify biomarkers for the condition, we assessed serum levels of apolipoprotein (Apo)A and ApoE. We found a reduction of both lipoproteins in anaphylactic mice as well as in orally challenged food allergic patients. We then compared patients after acute anaphylaxis with several control groups (nonallergic, history of allergen-triggered anaphylaxis, acute cardiovascular/febrile reactions). In this unpaired setting, ApoE levels were unaltered, while ApoA1 was reduced in the anaphylactic group. Although unable to discriminate between anaphylaxis and cardiovascular/febrile reactions, ROC curve analysis revealed a reasonably high area under the curve (AUC) of 0.91 for ApoA1. Serum 9α,11ß-PGF2 , recently identified as a suitable biomarker for anaphylaxis, outperformed ApoA1 with AUC=0.95. Intriguingly however its power further increased upon combination of both mediators reaching AUC=1. Our data suggest that ApoA1 combined with 9α,11ß-PGF2 represents a useful composite biomarker of anaphylaxis, achieving superior diagnostic power over either factor alone.
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Affiliation(s)
- M. Wittenberg
- Department of Dermatology and Allergy Allergy Center Charité, CCM Charité‐Universitätsmedizin Berlin Berlin Germany
| | - M. Nassiri
- Department of Dermatology and Allergy Allergy Center Charité, CCM Charité‐Universitätsmedizin Berlin Berlin Germany
| | - W. Francuzik
- Department of Dermatology and Allergy Allergy Center Charité, CCM Charité‐Universitätsmedizin Berlin Berlin Germany
| | | | - M. Babina
- Department of Dermatology and Allergy Allergy Center Charité, CCM Charité‐Universitätsmedizin Berlin Berlin Germany
| | - M. Worm
- Department of Dermatology and Allergy Allergy Center Charité, CCM Charité‐Universitätsmedizin Berlin Berlin Germany
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Dinnes DLM, White MY, Kockx M, Traini M, Hsieh V, Kim M, Hou L, Jessup W, Rye K, Thaysen‐Andersen M, Cordwell SJ, Kritharides L. Human macrophage cathepsin β‐mediated C‐terminal cleavage of apolipoprotein α‐I at Ser
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severely impairs antiatherogenic capacity. FASEB J 2016; 30:4239-4255. [DOI: 10.1096/fj.201600508r] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 09/01/2016] [Indexed: 11/11/2022]
Affiliation(s)
| | - Melanie Y. White
- School of Molecular BioscienceDiscipline of Pathology School of Medical Sciences and Charles Perkins Centre University of Sydney Sydney New South Wales Australia
| | - Maaike Kockx
- Atherosclerosis LaboratoryANZAC Research Institute
| | | | - Victar Hsieh
- Department of CardiologySt. George Hospital Sydney New South Wales Australia
| | - Mi‐Jurng Kim
- School of Medical Sciences Sydney New South Wales Australia
| | - Liming Hou
- Lipid Research GroupSchool of Medical Sciences University of New South Wales Sydney New South Wales Australia
| | - Wendy Jessup
- Atherosclerosis LaboratoryANZAC Research Institute
| | - Kerry‐Anne Rye
- Lipid Research GroupSchool of Medical Sciences University of New South Wales Sydney New South Wales Australia
| | - Morten Thaysen‐Andersen
- Department of Chemistry and Biomolecular SciencesFaculty of Science and Engineering Macquarie University Sydney New South Wales Australia
| | - Stuart J. Cordwell
- School of Molecular BioscienceDiscipline of Pathology School of Medical Sciences and Charles Perkins Centre University of Sydney Sydney New South Wales Australia
| | - Leonard Kritharides
- Atherosclerosis LaboratoryANZAC Research Institute
- Department of CardiologyConcord Repatriation General Hospital Sydney New South Wales Australia
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10
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High-Density Lipoprotein Binds to Mycobacterium avium and Affects the Infection of THP-1 Macrophages. J Lipids 2016; 2016:4353620. [PMID: 27516907 PMCID: PMC4969507 DOI: 10.1155/2016/4353620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 06/13/2016] [Indexed: 12/25/2022] Open
Abstract
High-density lipoprotein (HDL) is involved in innate immunity toward various infectious diseases. Concerning bacteria, HDL is known to bind to lipopolysaccharide (LPS) and to neutralize its physiological activity. On the other hand, cholesterol is known to play an important role in mycobacterial entry into host cells and in survival in the intracellular environment. However, the pathogenicity of Mycobacterium avium (M. avium) infection, which tends to increase worldwide, remains poorly studied. Here we report that HDL indicated a stronger interaction with M. avium than that with other Gram-negative bacteria containing abundant LPS. A binding of apolipoprotein (apo) A-I, the main protein component of HDL, with a specific lipid of M. avium might participate in this interaction. HDL did not have a direct bactericidal activity toward M. avium but attenuated the engulfment of M. avium by THP-1 macrophages. HDL also did not affect bacterial killing after ingestion of live M. avium by THP-1 macrophage. Furthermore, HDL strongly promoted the formation of lipid droplets in M. avium-infected THP-1 macrophages. These observations provide new insights into the relationship between M. avium infection and host lipoproteins, especially HDL. Thus, HDL may help M. avium to escape from host innate immunity.
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11
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Takai S, Jin D. Improvement of cardiovascular remodelling by chymase inhibitor. Clin Exp Pharmacol Physiol 2016; 43:387-93. [DOI: 10.1111/1440-1681.12549] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 01/14/2016] [Accepted: 01/16/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Shinji Takai
- Department of Innovative Medicine; Graduate School of Medicine; Osaka Medical College; Takatsuki Japan
| | - Denan Jin
- Department of Pharmacology; Osaka Medical College; Takatsuki Japan
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12
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Houde M, Desbiens L, Schwertani A, Pejler G, Iglarz M, D'Orléans-Juste P. Endothelin receptor antagonist macitentan or deletion of mouse mast cell protease 4 delays lesion development in atherosclerotic mice. Life Sci 2016; 159:71-75. [PMID: 26976326 DOI: 10.1016/j.lfs.2016.03.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 02/12/2016] [Accepted: 03/09/2016] [Indexed: 11/16/2022]
Abstract
AIMS To determine the impact of mixed endothelin receptor antagonist and mouse mast cell protease-4 (mMCP-4) in the development of atherosclerosis in the mouse model. MATERIALS AND METHODS Apolipoprotein E (ApoE) KO mice were crossed with mMCP-4 KO mice to generate ApoE/mMCP-4 double KO mice. Atherosclerosis was induced with a normal- or high-fat diet for 12, 27 or 52weeks. Macitentan (30mg/kg/day), a dual ETA/ETB receptor antagonist, was given orally for 6weeks (27week protocol). At sacrifice, aortas and brachiocephalic arteries (BCAs) were collected. En face Sudan IV staining was performed on aortas and BCA sections were subjected to Masson's trichrome stain and α-smooth muscle actin labeling. KEY FINDINGS Under normal diet, both macitentan treatment and the absence of mMCP-4 reduced the development of aortic atherosclerotic lesions in 27-week old ApoE KO mice, but mMCP-4 deletion failed to maintain this effect on 52-week old mice. Under high-fat diet (WD), macitentan, but not the absence of mMCP-4, reduced aortic lesion development in ApoE KO mice. On BCA lesions of 27-week old WD mice, macitentan treatment had a small impact while mMCP-4 deletion showed improved features of plaque stability. SIGNIFICANCE These results suggest that the inhibition of mMCP-4 reduces lesion spreading in the earlier phases of atherosclerosis development and can help stabilise the more advanced plaque. Macitentan treatment was more effective to prevent lesion spreading but did not improve plaque features to the same extent.
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Affiliation(s)
- Martin Houde
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Louisane Desbiens
- Department of Pharmacology, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Adel Schwertani
- Department of Cardiology, McGill University, Montréal, QC, Canada
| | - Gunnar Pejler
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Marc Iglarz
- Drug Discovery Department, Actelion Pharmaceuticals Ltd., Allschwil, Switzerland
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13
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Nguyen SD, Maaninka K, Lappalainen J, Nurmi K, Metso J, Öörni K, Navab M, Fogelman AM, Jauhiainen M, Lee-Rueckert M, Kovanen PT. Carboxyl-Terminal Cleavage of Apolipoprotein A-I by Human Mast Cell Chymase Impairs Its Anti-Inflammatory Properties. Arterioscler Thromb Vasc Biol 2015; 36:274-84. [PMID: 26681753 PMCID: PMC4725095 DOI: 10.1161/atvbaha.115.306827] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 11/18/2015] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Apolipoprotein A-I (apoA-I) has been shown to possess several atheroprotective functions, including inhibition of inflammation. Protease-secreting activated mast cells reside in human atherosclerotic lesions. Here we investigated the effects of the neutral proteases released by activated mast cells on the anti-inflammatory properties of apoA-I. APPROACH AND RESULTS Activation of human mast cells triggered the release of granule-associated proteases chymase, tryptase, cathepsin G, carboxypeptidase A, and granzyme B. Among them, chymase cleaved apoA-I with the greatest efficiency and generated C-terminally truncated apoA-I, which failed to bind with high affinity to human coronary artery endothelial cells. In tumor necrosis factor-α-activated human coronary artery endothelial cells, the chymase-cleaved apoA-I was unable to suppress nuclear factor-κB-dependent upregulation of vascular cell adhesion molecule-1 (VCAM-1) and to block THP-1 cells from adhering to and transmigrating across the human coronary artery endothelial cells. Chymase-cleaved apoA-I also had an impaired ability to downregulate the expression of tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 in lipopolysaccharide-activated GM-CSF (granulocyte-macrophage colony-stimulating factor)- and M-CSF (macrophage colony-stimulating factor)-differentiated human macrophage foam cells and to inhibit reactive oxygen species formation in PMA (phorbol 12-myristate 13-acetate)-activated human neutrophils. Importantly, chymase-cleaved apoA-I showed reduced ability to inhibit lipopolysaccharide-induced inflammation in vivo in mice. Treatment with chymase blocked the ability of the apoA-I mimetic peptide L-4F, but not of the protease-resistant D-4F, to inhibit proinflammatory gene expression in activated human coronary artery endothelial cells and macrophage foam cells and to prevent reactive oxygen species formation in activated neutrophils. CONCLUSIONS The findings identify C-terminal cleavage of apoA-I by human mast cell chymase as a novel mechanism leading to loss of its anti-inflammatory functions. When targeting inflamed protease-rich atherosclerotic lesions with apoA-I, infusions of protease-resistant apoA-I might be the appropriate approach.
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Affiliation(s)
- Su Duy Nguyen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Maaninka
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Jani Lappalainen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Nurmi
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Jari Metso
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Öörni
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Mohamad Navab
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Alan M Fogelman
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Matti Jauhiainen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Miriam Lee-Rueckert
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Petri T Kovanen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.).
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Lee-Rueckert M, Kovanen PT. The mast cell as a pluripotent HDL-modifying effector in atherogenesis: from in vitro to in vivo significance. Curr Opin Lipidol 2015; 26:362-8. [PMID: 26339766 DOI: 10.1097/mol.0000000000000224] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize evidence about the effects that mast cell mediators can exert on the cholesterol efflux-inducing function of high density lipoproteins (HDL). RECENT FINDINGS Subendothelially located activated mast cells are present in inflamed tissue sites, in which macrophage foam cells are also present. Upon activation, mast cells degranulate and expel 2 major neutral proteases, chymase and tryptase, and the vasoactive compound histamine, all of which are bound to the heparin-proteoglycan matrix of the granules. In the extracellular fluid, the proteases remain heparin-bound and retain their activities, whereas histamine dissociates and diffuses away to reach the endothelium. The heparin-bound mast cell proteases avidly degrade lipid-poor HDL particles so preventing their ability to induce cholesterol efflux from macrophage foam cells. In contrast, histamine enhances the passage of circulating HDL through the vascular endothelium into interstitial fluids, so favoring HDL interaction with peripheral macrophage foam cells and accelerating initiation of macrophage-specific reverse cholesterol transport. SUMMARY Mast cells exert various modulatory effects on HDL function. In this novel tissue cholesterol-regulating function, the functional balance of histamine and proteases, and the relative quantities of HDL particles in the affected microenvironment ultimately dictate the outcome of the multiple mast cell effects on tissue cholesterol content.
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15
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Cubedo J, Padró T, García-Arguinzonis M, Vilahur G, Miñambres I, Pou JM, Ybarra J, Badimon L. A novel truncated form of apolipoprotein A-I transported by dense LDL is increased in diabetic patients. J Lipid Res 2015; 56:1762-73. [PMID: 26168996 DOI: 10.1194/jlr.p057513] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Indexed: 11/20/2022] Open
Abstract
Diabetic (DM) patients have exacerbated atherosclerosis and high CVD burden. Changes in lipid metabolism, lipoprotein structure, and dysfunctional HDL are characteristics of diabetes. Our aim was to investigate whether serum ApoA-I, the main protein in HDL, was biochemically modified in DM patients. By using proteomic technologies, we have identified a 26 kDa ApoA-I form in serum. MS analysis revealed this 26 kDa form as a novel truncated variant lacking amino acids 1-38, ApoA-IΔ(1-38). DM patients show a 2-fold increase in ApoA-IΔ(1-38) over nondiabetic individuals. ApoA-IΔ(1-38) is found in LDL, but not in VLDL or HDL, with an increase in LDL3 and LDL4 subfractions. To identify candidate mechanisms of ApoA-I truncation, we investigated potentially involved enzymes by in silico data mining, and tested the most probable molecule in an established animal model of diabetes. We have found increased hepatic cathepsin D activity as one of the potential proteases involved in ApoA-I truncation. Cathepsin D-cleaved ApoA-I exhibited increased LDL binding affinity and decreased antioxidant activity against LDL oxidation. In conclusion, we show for the first time: a) presence of a novel truncated ApoA-I form, ApoA-IΔ(1-38), in human serum; b) ApoA-IΔ(1-38) is transported by LDL; c) ApoA-IΔ(1-38) is increased in dense LDL fractions of DM patients; and d) cathepsin D-ApoA-I truncation may lead to ApoA-IΔ(1-38) binding to LDLs, increasing their susceptibility to oxidation and contributing to the high cardiovascular risk of DM patients.
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Affiliation(s)
- Judit Cubedo
- Cardiovascular Research Center (CSIC-ICCC), Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Teresa Padró
- Cardiovascular Research Center (CSIC-ICCC), Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Maisa García-Arguinzonis
- Cardiovascular Research Center (CSIC-ICCC), Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Gemma Vilahur
- Cardiovascular Research Center (CSIC-ICCC), Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain
| | - Inka Miñambres
- Endocrinology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | - Jose María Pou
- Endocrinology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
| | | | - Lina Badimon
- Cardiovascular Research Center (CSIC-ICCC), Biomedical Research Institute Sant Pau (IIB-Sant Pau), Barcelona, Spain Cardiovascular Research Chair, Universitat Autònoma de Barcelona, Barcelona, Spain
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16
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Favari E, Chroni A, Tietge UJF, Zanotti I, Escolà-Gil JC, Bernini F. Cholesterol efflux and reverse cholesterol transport. Handb Exp Pharmacol 2015; 224:181-206. [PMID: 25522988 DOI: 10.1007/978-3-319-09665-0_4] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Both alterations of lipid/lipoprotein metabolism and inflammatory events contribute to the formation of the atherosclerotic plaque, characterized by the accumulation of abnormal amounts of cholesterol and macrophages in the artery wall. Reverse cholesterol transport (RCT) may counteract the pathogenic events leading to the formation and development of atheroma, by promoting the high-density lipoprotein (HDL)-mediated removal of cholesterol from the artery wall. Recent in vivo studies established the inverse relationship between RCT efficiency and atherosclerotic cardiovascular diseases (CVD), thus suggesting that the promotion of this process may represent a novel strategy to reduce atherosclerotic plaque burden and subsequent cardiovascular events. HDL plays a primary role in all stages of RCT: (1) cholesterol efflux, where these lipoproteins remove excess cholesterol from cells; (2) lipoprotein remodeling, where HDL undergo structural modifications with possible impact on their function; and (3) hepatic lipid uptake, where HDL releases cholesterol to the liver, for the final excretion into bile and feces. Although the inverse association between HDL plasma levels and CVD risk has been postulated for years, recently this concept has been challenged by studies reporting that HDL antiatherogenic functions may be independent of their plasma levels. Therefore, assessment of HDL function, evaluated as the capacity to promote cell cholesterol efflux may offer a better prediction of CVD than HDL levels alone. Consistent with this idea, it has been recently demonstrated that the evaluation of serum cholesterol efflux capacity (CEC) is a predictor of atherosclerosis extent in humans.
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Affiliation(s)
- Elda Favari
- Department of Pharmacy, University of Parma, Parco Area delle Scienze 27/A, 43124, Parma, Italy
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17
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Kontush A, Lindahl M, Lhomme M, Calabresi L, Chapman MJ, Davidson WS. Structure of HDL: particle subclasses and molecular components. Handb Exp Pharmacol 2015; 224:3-51. [PMID: 25522985 DOI: 10.1007/978-3-319-09665-0_1] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
A molecular understanding of high-density lipoprotein (HDL) will allow a more complete grasp of its interactions with key plasma remodelling factors and with cell-surface proteins that mediate HDL assembly and clearance. However, these particles are notoriously heterogeneous in terms of almost every physical, chemical and biological property. Furthermore, HDL particles have not lent themselves to high-resolution structural study through mainstream techniques like nuclear magnetic resonance and X-ray crystallography; investigators have therefore had to use a series of lower resolution methods to derive a general structural understanding of these enigmatic particles. This chapter reviews current knowledge of the composition, structure and heterogeneity of human plasma HDL. The multifaceted composition of the HDL proteome, the multiple major protein isoforms involving translational and posttranslational modifications, the rapidly expanding knowledge of the HDL lipidome, the highly complex world of HDL subclasses and putative models of HDL particle structure are extensively discussed. A brief history of structural studies of both plasma-derived and recombinant forms of HDL is presented with a focus on detailed structural models that have been derived from a range of techniques spanning mass spectrometry to molecular dynamics.
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Affiliation(s)
- Anatol Kontush
- National Institute for Health and Medical Research (INSERM), UMR-ICAN 1166, Paris, France,
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18
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Bot I, Shi GP, Kovanen PT. Mast cells as effectors in atherosclerosis. Arterioscler Thromb Vasc Biol 2014; 35:265-71. [PMID: 25104798 DOI: 10.1161/atvbaha.114.303570] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The mast cell is a potent immune cell known for its functions in host defense responses and diseases, such as asthma and allergies. In the past years, accumulating evidence established the contribution of the mast cell to cardiovascular diseases as well, in particular, by its effects on atherosclerotic plaque progression and destabilization. Through its release not only of mediators, such as the mast cell-specific proteases chymase and tryptase, but also of growth factors, histamine, and chemokines, activated mast cells can have detrimental effects on its immediate surroundings in the vessel wall. This results in matrix degradation, apoptosis, and enhanced recruitment of inflammatory cells, thereby actively contributing to cardiovascular diseases. In this review, we will discuss the current knowledge on mast cell function in cardiovascular diseases and speculate on potential novel therapeutic strategies to prevent acute cardiovascular syndromes via targeting of mast cells.
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Affiliation(s)
- Ilze Bot
- From the Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (I.B.); Department of Medicine, Brigham and Woman's Hospital and Harvard Medical School, Boston, MA (G.-P.S.); and Wihuri Research Institute, Helsinki, Finland (P.T.K.).
| | - Guo-Ping Shi
- From the Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (I.B.); Department of Medicine, Brigham and Woman's Hospital and Harvard Medical School, Boston, MA (G.-P.S.); and Wihuri Research Institute, Helsinki, Finland (P.T.K.)
| | - Petri T Kovanen
- From the Division of Biopharmaceutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands (I.B.); Department of Medicine, Brigham and Woman's Hospital and Harvard Medical School, Boston, MA (G.-P.S.); and Wihuri Research Institute, Helsinki, Finland (P.T.K.)
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19
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Identification of sites in apolipoprotein A-I susceptible to chymase and carboxypeptidase A digestion. Biosci Rep 2012; 33:49-56. [PMID: 23072735 PMCID: PMC3522476 DOI: 10.1042/bsr20120094] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
MCs (mast cells) adversely affect atherosclerosis by promoting the progression of lesions and plaque destabilization. MC chymase cleaves apoA-I (apolipoprotein A-I), the main protein component of HDL (high-density lipoprotein). We previously showed that C-terminally truncated apoA-I (cleaved at the carboxyl side of Phe225) is present in normal human serum using a newly developed specific mAb (monoclonal antibody). In the present study, we aimed to identify chymase-induced cleavage sites in both lipid-free and lipid-bound (HDL3) forms of apoA-I. Lipid-free apoA-I was preferentially digested by chymase, at the C-terminus rather than the N-terminus. Phe229 and Tyr192 residues were the main cleavage sites. Interestingly, the Phe225 residue was a minor cleavage site. In contrast, the same concentration of chymase failed to digest apoA-I in HDL3; however, a 100-fold higher concentration of chymase modestly digested apoA-I in HDL3 at only the N-terminus, especially at Phe33. CPA (carboxypeptidase A) is another MC protease, co-localized with chymase in severe atherosclerotic lesions. CPA, in vitro, further cleaved C-terminal Phe225 and Phe229 residues newly exposed by chymase, but did not cleave Tyr192. These results indicate that several forms of C-terminally and N-terminally truncated apoA-I could exist in the circulation. They may be useful as new biomarkers to assess the risk of CVD (cardiovascular disease).
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