1
|
Nakamura Y, Kulkarni NN, Takahashi T, Alimohamadi H, Dokoshi T, Liu E, Shia M, Numata T, Luo EW, Gombart AF, Yang X, Secrest P, Gordts PL, Tsimikas S, Wong GC, Gallo RL. Increased LL37 in psoriasis and other inflammatory disorders promotes LDL uptake and atherosclerosis. J Clin Invest 2024; 134:e172578. [PMID: 38194294 PMCID: PMC10904043 DOI: 10.1172/jci172578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 01/05/2024] [Indexed: 01/10/2024] Open
Abstract
Patients with chronic inflammatory disorders such as psoriasis have an increased risk of cardiovascular disease and elevated levels of LL37, a cathelicidin host defense peptide that has both antimicrobial and proinflammatory properties. To explore whether LL37 could contribute to the risk of heart disease, we examined its effects on lipoprotein metabolism and show that LL37 enhanced LDL uptake in macrophages through the LDL receptor (LDLR), scavenger receptor class B member 1 (SR-B1), and CD36. This interaction led to increased cytosolic cholesterol in macrophages and changes in expression of lipid metabolism genes consistent with increased cholesterol uptake. Structure-function analysis and synchrotron small-angle x-ray scattering showed structural determinants of the LL37-LDL complex that underlie its ability to bind its receptors and promote uptake. This function of LDL uptake is unique to cathelicidins from humans and some primates and was not observed with cathelicidins from mice or rabbits. Notably, Apoe-/- mice expressing LL37 developed larger atheroma plaques than did control mice, and a positive correlation between plasma LL37 and oxidized phospholipid on apolipoprotein B (OxPL-apoB) levels was observed in individuals with cardiovascular disease. These findings provide evidence that LDL uptake can be increased via interaction with LL37 and may explain the increased risk of cardiovascular disease associated with chronic inflammatory disorders.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Adrian F. Gombart
- Linus Pauling Institute, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, USA
| | | | - Patrick Secrest
- Department of Medicine, Division of Endocrinology and Metabolism, and
| | - Philip L.S.M. Gordts
- Department of Medicine, Division of Endocrinology and Metabolism, and
- Glycobiology Research and Training Center, UCSD, La Jolla, California, USA
| | | | - Gerard C.L. Wong
- Department of Bioengineering, UCLA, Los Angeles, California, USA
| | | |
Collapse
|
2
|
Hu K, Perez-Matos MC, Argemi J, Vilar-Gomez E, Shalaurova I, Bullitt E, Landeen L, Sugahara G, Deng H, Mathur K, Tran S, Cai H, He H, Yalcin Y, Vieira Barbosa J, Ventura-Cots M, Marx K, Gad AP, Niezen S, Izunza Barba S, Ang LH, Popov YV, Fricker Z, Lai M, Curry M, Afdhal N, Szabo G, Mukamal KJ, Sanyal AJ, Otvos JD, Malik R, Saito T, Connelly MA, Chalasani NP, Bataller R, Jiang ZG. Lipoprotein Z, a hepatotoxic lipoprotein, predicts outcome in alcohol-associated hepatitis. Hepatology 2022; 75:968-982. [PMID: 34662439 PMCID: PMC9299888 DOI: 10.1002/hep.32203] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 09/01/2021] [Accepted: 09/20/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND AIMS Lipoprotein Z (LP-Z) is an abnormal free cholesterol (FC)-enriched LDL-like particle discovered from patients with cholestatic liver disease. This study aims to define the diagnostic value of LP-Z in alcohol-associated hepatitis (AH) and interrogate the biology behind its formation. APPROACH AND RESULTS We measured serum levels of LP-Z using nuclear magnetic resonance spectroscopy, a well-established clinical assay. Serum levels of LP-Z were significantly elevated in four AH cohorts compared with control groups, including heavy drinkers and patients with cirrhosis. We defined a Z-index, calculated by the ratio of LP-Z to total apolipoprotein B-containing lipoproteins, representing the degree of deviation from normal VLDL metabolism. A high Z-index was associated with 90-day mortality independent from the Model for End-Stage Liver Disease (MELD) and provided added prognosticative value. Both a Z-index ≤ 0.6 and a decline of Z-index by ≥0.1 in 2 weeks predicted 90-day survival. RNA-sequencing analyses of liver tissues demonstrated an inverse association in the expression of enzymes responsible for the extrahepatic conversion of VLDL to LDL and AH disease severity, which was further confirmed by the measurement of serum enzyme activity. To evaluate whether the FC in LP-Z could contribute to the pathogenesis of AH, we found significantly altered FC levels in liver explant of patients with AH. Furthermore, FC in reconstituted LP-Z particles caused direct toxicity to human hepatocytes in a concentration-dependent manner, supporting a pathogenic role of FC in LP-Z. CONCLUSIONS Impaired lipoprotein metabolism in AH leads to the accumulation of LP-Z in the circulation, which is hepatotoxic from excessive FC. A Z-index ≤ 0.6 predicts 90-day survival independent from conventional biomarkers for disease prognostication.
Collapse
Affiliation(s)
- Kunpeng Hu
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA.,Division of General SurgeryThe Third Affiliated Hospital of Sun Yat-Sen UniversityGuangzhouChina
| | - Maria C Perez-Matos
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Josepmaria Argemi
- Division of Gastroenterology, Hepatology, and NutritionUniversity of Pittsburgh Medical CenterPittsburghPennsylvaniaUSA.,Hepatology ProgramCentro de Investigacion Medica Aplicada, Liver UnitClinica Universidad de NavarraInstituto de Investigacion de NavarraUniversity of NavarraPamplonaSpain
| | - Eduardo Vilar-Gomez
- Division of Gastroenterology and HepatologyIndiana University School of MedicineIndianapolisIndianaUSA
| | - Irina Shalaurova
- Laboratory Corporation of America HoldingsMorrisvilleNorth CarolinaUSA
| | - Esther Bullitt
- Department of Physiology and BiophysicsBoston University School of MedicineBostonMassachusettsUSA
| | | | - Go Sugahara
- Division of Gastrointestinal and Liver DiseasesKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA.,Research and Development DepartmentPhoenixBio, Co., LtdHigashi-Hiroshima, HiroshimaJapan
| | - Huiyan Deng
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Karan Mathur
- Division of Gastroenterology and HepatologyIndiana University School of MedicineIndianapolisIndianaUSA
| | - Stephanie Tran
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Huimei Cai
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Hanchang He
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Yusuf Yalcin
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Joana Vieira Barbosa
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA.,Division of Gastroenterology and HepatologyLausanne University Hospital and University of LausanneLausanneSwitzerland
| | - Meritxell Ventura-Cots
- Division of Gastroenterology, Hepatology, and NutritionUniversity of Pittsburgh Medical CenterPittsburghPennsylvaniaUSA
| | - Katherine Marx
- Transplant InstituteDepartment of SurgeryBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Aniket P Gad
- Confocal Imaging Core facilityBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Sebastian Niezen
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Sofia Izunza Barba
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Lay-Hong Ang
- Confocal Imaging Core facilityBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Yury V Popov
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Zachary Fricker
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Michelle Lai
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Michael Curry
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Nezam Afdhal
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Gyongyi Szabo
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Kenneth J Mukamal
- Division of General MedicineDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| | - Arun J Sanyal
- Division of Gastroenterology, Hepatology and NutritionVirginia Commonwealth University School of MedicineRichmondVirginiaUSA
| | - James D Otvos
- Laboratory Corporation of America HoldingsMorrisvilleNorth CarolinaUSA
| | - Raza Malik
- Liver CenterDivision of GastroenterologyTufts Medical CenterBostonMassachusettsUSA
| | - Takeshi Saito
- Division of Gastrointestinal and Liver DiseasesKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCaliforniaUSA
| | | | - Naga P Chalasani
- Division of Gastroenterology and HepatologyIndiana University School of MedicineIndianapolisIndianaUSA
| | - Ramon Bataller
- Division of Gastroenterology, Hepatology, and NutritionUniversity of Pittsburgh Medical CenterPittsburghPennsylvaniaUSA
| | - Z Gordon Jiang
- Division of Gastroenterology, Hepatology, and NutritionDepartment of MedicineBeth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMassachusettsUSA
| |
Collapse
|
3
|
Jakubauskas D, Jansen M, Lyngsø J, Cheng Y, Pedersen JS, Cárdenas M. Toward reliable low-density lipoprotein ultrastructure prediction in clinical conditions: A small-angle X-ray scattering study on individuals with normal and high triglyceride serum levels. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 31:102318. [PMID: 33091569 DOI: 10.1016/j.nano.2020.102318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/23/2020] [Accepted: 10/05/2020] [Indexed: 10/23/2022]
Abstract
Atherosclerosis is the main killer in the west and therefore a major health challenge today. Total serum cholesterol and lipoprotein concentrations, used as clinical markers, fail to predict the majority of cases, especially between the risk scale extremes, due to the high complexity in lipoprotein structure and composition. In particular, low-density lipoprotein (LDL) plays a key role in atherosclerosis development, with LDL size being a parameter considered for determining the risk for cardiovascular diseases. Determining LDL size and structural parameters is challenging to address experimentally under physiological-like conditions. This article describes the biochemistry and ultrastructure of normolipidemic and hypertriglyceridemic LDL fractions and subfractions using small-angle X-ray scattering. Our results conclude that LDL particles of hypertriglyceridemic compared to healthy individuals 1) have lower LDL core melting temperature, 2) have lower cholesteryl ester ordering in their core, 3) are smaller, rounder and more spherical below melting temperature, and 4) their protein-containing shell is thinner above melting temperature.
Collapse
Affiliation(s)
- Dainius Jakubauskas
- Biofilms - Research center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmo University, Malmo, Sweden.
| | - Martin Jansen
- Institute of Clinical Chemistry and Laboratory Medicine, Medical Centre, University of Freiburg, Freiburg im Breisgau, Germany.
| | - Jeppe Lyngsø
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
| | - Yuanji Cheng
- Department of Materials Science and Applied Mathematics, Faculty of Technology and Society, Malmo University, Malmo, Sweden.
| | - Jan Skov Pedersen
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
| | - Marité Cárdenas
- Biofilms - Research center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmo University, Malmo, Sweden.
| |
Collapse
|
4
|
Baumstark D, Kremer W, Boettcher A, Schreier C, Sander P, Schmitz G, Kirchhoefer R, Huber F, Kalbitzer HR. 1H NMR spectroscopy quantifies visibility of lipoproteins, subclasses, and lipids at varied temperatures and pressures. J Lipid Res 2019; 60:1516-1534. [PMID: 31239285 PMCID: PMC6718440 DOI: 10.1194/jlr.m092643] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 06/18/2019] [Indexed: 01/27/2023] Open
Abstract
NMR-based quantification of human lipoprotein (sub)classes is a powerful high-throughput method for medical diagnostics. We evaluated select proton NMR signals of serum lipoproteins for elucidating the physicochemical features and the absolute NMR visibility of their lipids. We separated human lipoproteins of different subclasses by ultracentrifugation and analyzed them by 1H NMR spectroscopy at different temperatures (283-323 K) and pressures (0.1-200 MPa). In parallel, we determined the total lipid content by extraction with chloroform/methanol. The visibility of different lipids in the 1H NMR spectra strongly depends on temperature and pressure: it increases with increasing temperatures but decreases with increasing pressures. Even at 313 K, only part of the lipoprotein is detected quantitatively. In LDL and in HDL subclasses HDL2 and HDL3, only 39%, 62%, and 90% of the total cholesterol and only 73%, 70%, and 87% of the FAs are detected, respectively. The choline head groups show visibilities of 43%, 75%, and 87% for LDL, HDL2, and HDL3, respectively. The description of the NMR visibility of lipid signals requires a minimum model of three different compartments, A, B, and C. The thermodynamic analysis of compartment B leads to melting temperatures between 282 K and 308 K and to enthalpy differences that vary for the different lipoproteins as well as for the reporter groups selected. In summary, we describe differences in NMR visibility of lipoproteins and variations in biophysical responses of functional groups that are crucial for the accuracy of absolute NMR quantification.
Collapse
Affiliation(s)
- Daniela Baumstark
- Institute of Biophysics and Physical BiochemistryUniversity of Regensburg, 93040 Regensburg, Germany; Centre of Magnetic Resonance in Chemistry and Biomedicine University of Regensburg, 93040 Regensburg, Germany
| | - Werner Kremer
- Institute of Biophysics and Physical BiochemistryUniversity of Regensburg, 93040 Regensburg, Germany; Centre of Magnetic Resonance in Chemistry and Biomedicine University of Regensburg, 93040 Regensburg, Germany
| | - Alfred Boettcher
- Institute of Clinical Chemistry and Laboratory Medicine University Hospital Regensburg, 93053 Regensburg, Germany
| | - Christina Schreier
- Institute of Biophysics and Physical BiochemistryUniversity of Regensburg, 93040 Regensburg, Germany; Centre of Magnetic Resonance in Chemistry and Biomedicine University of Regensburg, 93040 Regensburg, Germany; numares AG, 93053 Regensburg, Germany
| | - Paul Sander
- Institute of Biophysics and Physical BiochemistryUniversity of Regensburg, 93040 Regensburg, Germany; Centre of Magnetic Resonance in Chemistry and Biomedicine University of Regensburg, 93040 Regensburg, Germany
| | - Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine University Hospital Regensburg, 93053 Regensburg, Germany
| | | | | | - Hans Robert Kalbitzer
- Institute of Biophysics and Physical BiochemistryUniversity of Regensburg, 93040 Regensburg, Germany; Centre of Magnetic Resonance in Chemistry and Biomedicine University of Regensburg, 93040 Regensburg, Germany.
| |
Collapse
|
5
|
Lehofer B, Golub M, Kornmueller K, Kriechbaum M, Martinez N, Nagy G, Kohlbrecher J, Amenitsch H, Peters J, Prassl R. High Hydrostatic Pressure Induces a Lipid Phase Transition and Molecular Rearrangements in Low-Density Lipoprotein Nanoparticles. PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION : MEASUREMENT AND DESCRIPTION OF PARTICLE PROPERTIES AND BEHAVIOR IN POWDERS AND OTHER DISPERSE SYSTEMS 2018; 35:1800149. [PMID: 30283212 PMCID: PMC6166783 DOI: 10.1002/ppsc.201800149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Indexed: 06/08/2023]
Abstract
Low-density lipoproteins (LDL) are natural lipid transporter in human plasma whose chemically modified forms contribute to the progression of atherosclerosis and cardiovascular diseases accounting for a vast majority of deaths in westernized civilizations. For the development of new treatment strategies, it is important to have a detailed picture of LDL nanoparticles on a molecular basis. Through the combination of X-ray and neutron small-angle scattering (SAS) techniques with high hydrostatic pressure (HHP) this study describes structural features of normolipidemic, triglyceride-rich and oxidized forms of LDL. Due to the different scattering contrasts for X-rays and neutrons, information on the effects of HHP on the internal structure determined by lipid rearrangements and changes in particle shape becomes accessible. Independent pressure and temperature variations provoke a phase transition in the lipid core domain. With increasing pressure an inter-related anisotropic deformation and flattening of the particle are induced. All LDL nanoparticles maintain their structural integrity even at 3000 bar and show a reversible response toward pressure variations. The present work depicts the complementarity of pressure and temperature as independent thermodynamic parameters and introduces HHP as a tool to study molecular assembling and interaction processes in distinct lipoprotein particles in a nondestructive manner.
Collapse
Affiliation(s)
- Bernhard Lehofer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/IV, 8010 Graz, Austria
| | - Maksym Golub
- Institut Laue-Langevin, 71 avenue des Martyrs, 38044 Grenoble, France; Univ. Grenoble Alpes, CNRS + CEA, IBS, 38000 Grenoble, France
| | - Karin Kornmueller
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/IV, 8010 Graz, Austria
| | - Manfred Kriechbaum
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Nicolas Martinez
- Institut Laue-Langevin, 71 avenue des Martyrs, 38044 Grenoble, France; Univ. Grenoble Alpes, CNRS + CEA, IBS, 38000 Grenoble, France
| | - Gergely Nagy
- Paul Scherrer Institut, 5232 Villigen, Switzerland; Wigner Research Centre for Physics, 1121 Budapest, Hungary; European Spallation Source ERIC, 22363 Lund, Sweden
| | | | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria
| | - Judith Peters
- Institut Laue-Langevin, 71 avenue des Martyrs, 38044 Grenoble, France; Univ. Grenoble Alpes, CNRS, LiPhy, 38000 Grenoble, France
| | - Ruth Prassl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/IV, 8010 Graz, Austria
| |
Collapse
|
6
|
Maric S, Lind TK, Lyngsø J, Cárdenas M, Pedersen JS. Modeling Small-Angle X-ray Scattering Data for Low-Density Lipoproteins: Insights into the Fatty Core Packing and Phase Transition. ACS NANO 2017; 11:1080-1090. [PMID: 28048943 DOI: 10.1021/acsnano.6b08089] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Atherosclerosis and its clinical consequences are the leading cause of death in the western hemisphere. While many studies throughout the last decades have aimed at understanding the disease, the clinical markers in use today still fail to accurately predict the risks. The role of the current main clinical indicator, low density lipoprotein (LDL), in depositing fat to the vessel wall is believed to be the onset of the process. However, many subfractions of the LDL, which differ both in structure and composition, are present in the blood and among different individuals. Understanding the relationship between LDL structure and composition is key to unravel the specific role of various LDL components in the development and/or prevention of atherosclerosis. Here, we describe a model for analyzing small-angle X-ray scattering data for rapid and robust structure determination for the LDL. The model not only gives the overall structure but also the particular internal layering of the fats inside the LDL core. Thus, the melting of the LDL can be followed in situ as a function of temperature for samples extracted from healthy human patients and purified using a double protocol based on ultracentrifugation and size-exclusion chromatography. The model provides information on: (i) the particle-specific melting temperature of the core lipids, (ii) the structural organization of the core fats inside the LDL, (iii) the overall shape of the particle, and (iv) the flexibility and overall conformation of the outer protein/hydrophilic layer at a given temperature as governed by the organization of the core. The advantage of this method over other techniques such as cryo-TEM is the possibility of in situ experiments under near-physiological conditions which can be performed relatively fast (minutes at home source, seconds at synchrotron). This approach now allows the monitoring of structural changes in the LDL upon different stresses from the environment, such as changes in temperature, oxidation, or external agents used or currently in development against atherosclerotic plaque build-up and which are targeting the LDL.
Collapse
Affiliation(s)
- Selma Maric
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Tania Kjellerup Lind
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Jeppe Lyngsø
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , 8000 Aarhus, Denmark
| | - Marité Cárdenas
- Biofilms- Research Center for Biointerfaces, Dept. of Biomedical Science, Faculty of Health and Society, Malmö University , Malmö 20506, Sweden
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO) and Department of Chemistry, Aarhus University , 8000 Aarhus, Denmark
| |
Collapse
|
7
|
Fernández-Higuero JA, Benito-Vicente A, Etxebarria A, Milicua JCG, Ostolaza H, Arrondo JLR, Martín C. Structural changes induced by acidic pH in human apolipoprotein B-100. Sci Rep 2016; 6:36324. [PMID: 27824107 PMCID: PMC5099883 DOI: 10.1038/srep36324] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 10/14/2016] [Indexed: 11/16/2022] Open
Abstract
Acidification in the endosome causes lipoprotein release by promoting a conformational change in the LDLR allowing its recycling and degradation of LDL. Notwithstanding conformational changes occurring in the LDLR have expanded considerably, structural changes occurring in LDL particles have not been fully explored yet. The objectives of the present work were to study structural changes occurring in apoB100 by infrared spectroscopy (IR) and also LDL size and morphology by dynamic light scattering (DLS) and electron microscopy (EM) at both pH 7.4 and 5.0. We determined by IR that pH acidification from 7.4 to 5.0, resembling that occurring within endosomal environment, induces a huge reversible structural rearrangement of apoB100 that is characterized by a reduction of beta-sheet content in favor of alpha-helix structures. Data obtained from DLS and EM showed no appreciable differences in size and morphology of LDL. These structural changes observed in apoB100, which are likely implied in particle release from lipoprotein receptor, also compromise the apoprotein stability what would facilitate LDL degradation. In conclusion, the obtained results reveal a more dynamic picture of the LDL/LDLR dissociation process than previously perceived and provide new structural insights into LDL/LDLR interactions than can occur at endosomal low-pH milieu.
Collapse
Affiliation(s)
- José A. Fernández-Higuero
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - Asier Benito-Vicente
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - Aitor Etxebarria
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - José Carlos G. Milicua
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - Helena Ostolaza
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - José L. R. Arrondo
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| | - Cesar Martín
- Biofisika Institute (UPV/EHU, CSIC), University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
- Dpt. Biochemistry and Molecular Biology, University of the Basque Country, UPV/EHU, Spain, Apdo. 644, 48080 Bilbao, Spain
| |
Collapse
|
8
|
Kornmueller K, Lehofer B, Meindl C, Fröhlich E, Leitinger G, Amenitsch H, Prassl R. Peptides at the Interface: Self-Assembly of Amphiphilic Designer Peptides and Their Membrane Interaction Propensity. Biomacromolecules 2016; 17:3591-3601. [PMID: 27741400 PMCID: PMC5111122 DOI: 10.1021/acs.biomac.6b01089] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
![]()
Self-assembling
amphiphilic designer peptides have been successfully
applied as nanomaterials in biomedical applications. Understanding
molecular interactions at the peptide–membrane interface is
crucial, since interactions at this site often determine (in)compatibility.
The present study aims to elucidate how model membrane systems of
different complexity (in particular single-component phospholipid
bilayers and lipoproteins) respond to the presence of amphiphilic
designer peptides. We focused on two short anionic peptides, V4WD2 and A6YD, which are structurally
similar but showed a different self-assembly behavior. A6YD self-assembled into high aspect ratio nanofibers at low peptide
concentrations, as evidenced by synchrotron small-angle X-ray scattering
and electron microscopy. These supramolecular assemblies coexisted
with membranes without remarkable interference. In contrast, V4WD2 formed only loosely associated assemblies over
a large concentration regime, and the peptide promoted concentration-dependent
disorder on the membrane arrangement. Perturbation effects were observed
on both membrane systems although most likely induced by different
modes of action. These results suggest that membrane activity critically
depends on the peptide’s inherent ability to form highly cohesive
supramolecular structures.
Collapse
Affiliation(s)
- Karin Kornmueller
- Institute of Biophysics, Medical University of Graz , BioTechMed-Graz, Harrachgasse 21/VI, 8010 Graz, Austria
| | - Bernhard Lehofer
- Institute of Biophysics, Medical University of Graz , BioTechMed-Graz, Harrachgasse 21/VI, 8010 Graz, Austria
| | - Claudia Meindl
- Center for Medical Research, Core Facility Imaging, Medical University of Graz , Stiftingtalstraße 24, 8010 Graz, Austria
| | - Eleonore Fröhlich
- Center for Medical Research, Core Facility Imaging, Medical University of Graz , Stiftingtalstraße 24, 8010 Graz, Austria
| | - Gerd Leitinger
- Institute of Cell Biology, Histology and Embryology, Research Unit Electron Microscopic Techniques, Medical University of Graz , Harrachgasse 21, 8010 Graz, Austria
| | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology , Stremayrgasse 9/4, 8010 Graz, Austria
| | - Ruth Prassl
- Institute of Biophysics, Medical University of Graz , BioTechMed-Graz, Harrachgasse 21/VI, 8010 Graz, Austria
| |
Collapse
|
9
|
Oliveira CLP, Santos PR, Monteiro AM, Figueiredo Neto AM. Effect of oxidation on the structure of human low- and high-density lipoproteins. Biophys J 2015; 106:2595-605. [PMID: 24940777 DOI: 10.1016/j.bpj.2014.04.049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/20/2014] [Accepted: 04/30/2014] [Indexed: 10/25/2022] Open
Abstract
This work presents a controlled study of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) structural changes due to in vitro oxidation with copper ions. The changes were studied by small-angle x-ray scattering (SAXS) and dynamic light scattering (DLS) techniques in the case of LDL and by SAXS, DLS, and Z-scan (ZS) techniques in the case of HDL. SAXS data were analyzed with a to our knowledge new deconvolution method. This method provides the electron density profile of the samples directly from the intensity scattering of the monomers. Results show that LDL particles oxidized for 18 h show significant structural changes when compared to nonoxidized particles. Changes were observed in the electrical density profile, in size polydispersity, and in the degree of flexibility of the APO-B protein on the particle. HDL optical results obtained with the ZS technique showed a decrease of the amplitude of the nonlinear optical signal as a function of oxidation time. In contrast to LDL results reported in the literature, the HDL ZS signal does not lead to a complete loss of nonlinear optical signal after 18 h of copper oxidation. Also, the SAXS results did not indicate significant structural changes due to oxidation of HDL particles, and DLS results showed that a small number of oligomers formed in the sample oxidized for 18 h. All experimental results for the HDL samples indicate that this lipoprotein is more resistant to the oxidation process than are LDL particles.
Collapse
|
10
|
Robinson MD, Cistola DP. Nanofluidity of fatty acid hydrocarbon chains as monitored by benchtop time-domain nuclear magnetic resonance. Biochemistry 2014; 53:7515-22. [PMID: 25409529 DOI: 10.1021/bi5011859] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The functional properties of lipid-rich assemblies such as serum lipoproteins, cell membranes, and intracellular lipid droplets are modulated by the fluidity of the hydrocarbon chain environment. Existing methods for monitoring hydrocarbon chain fluidity include fluorescence, electron spin resonance, and nuclear magnetic resonance (NMR) spectroscopy; each possesses advantages and limitations. Here we introduce a new approach based on benchtop time-domain (1)H NMR relaxometry (TD-NMR). Unlike conventional NMR spectroscopy, TD-NMR does not rely on the chemical shift resolution made possible by homogeneous, high-field magnets and Fourier transforms. Rather, it focuses on a multiexponential analysis of the time decay signal. In this study, we investigated a series of single-phase fatty acid oils, which allowed us to correlate (1)H spin-spin relaxation time constants (T2) with experimental measures of sample fluidity, as obtained using a viscometer. Remarkably, benchtop TD-NMR at 40 MHz was able to resolve two to four T2 components in biologically relevant fatty acids, assigned to nanometer-scale domains in different segments of the hydrocarbon chain. The T2 values for each domain were exquisitely sensitive to hydrocarbon chain structure; the largest values were observed for pure fatty acids or mixtures with the highest cis-double bond content. Moreover, the T2 values for each domain exhibited positive linear correlations with fluidity. The TD-NMR T2 and fluidity measurements appear to be monitoring the same underlying phenomenon: variations in hydrocarbon chain packing. The results from this study validate the use of benchtop TD-NMR T2 as a nanofluidity meter and demonstrate its potential for probing nanofluidity in other systems of biological interest.
Collapse
Affiliation(s)
- Michelle D Robinson
- Nanoparticle Diagnostics Research Laboratory, Division of Research & Innovation, and Department of Integrative Physiology, University of North Texas Health Science Center , Fort Worth, Texas 76107, United States
| | | |
Collapse
|
11
|
Lancaster JL, Antonijevic T, Starobin JM. Ordering and stability in lipid droplets with applications to low-density lipoproteins. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:062708. [PMID: 25019815 DOI: 10.1103/physreve.89.062708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Indexed: 06/03/2023]
Abstract
In this article, we present a framework for investigating the order-disorder transition in lipid droplets using the standard Ising model. While a single lipid droplet is itself a complex system whose constituent cholesteryl esters each possesses many degrees of freedom, we present justification for using this effective approach to isolate the underlying physics. It is argued that the behavior of the esters confined within lipid droplets is significantly different from that of a bulk system of similar esters, which is adequately described by continuum mean-field theory in the thermodynamic limit. When the droplet's shell is modeled as an elastic membrane, a simple picture emerges for a transition between two ordered phases within the core which is tuned by the strength of interactions between the esters. Triglyceride concentration is proposed as a variable which strongly influences the strength of interactions between cholesteryl esters within droplets. The possible relevance of this mechanism to the well known atherogenic nature of small low-density lipoprotein particles is discussed in detail.
Collapse
Affiliation(s)
- Jarrett L Lancaster
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, 2907 E. Lee Street, Greensboro, North Carolina 27401, USA
| | - Todor Antonijevic
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, 2907 E. Lee Street, Greensboro, North Carolina 27401, USA
| | - Joseph M Starobin
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, 2907 E. Lee Street, Greensboro, North Carolina 27401, USA
| |
Collapse
|
12
|
Rath EM, Duff AP, Håkansson AP, Knott RB, Church WB. Small-angle X-ray scattering of BAMLET at pH 12: a complex of α-lactalbumin and oleic acid. Proteins 2014; 82:1400-8. [PMID: 24408789 DOI: 10.1002/prot.24508] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 12/04/2013] [Accepted: 12/26/2013] [Indexed: 11/11/2022]
Abstract
BAMLET (Bovine Alpha-lactalbumin Made LEthal to Tumors) is a member of the family of the HAMLET-like complexes, a novel class of protein-based anti-cancer complexes that incorporate oleic acid and deliver it to cancer cells. Small angle X-ray scattering (SAXS) was performed on the complex at pH 12, examining the high pH structure as a function of oleic acid added. The SAXS data for BAMLET species prepared with a range of oleic acid concentrations indicate extended, irregular, partially unfolded protein conformations that vary with the oleic acid concentration. Increases in oleic acid concentration correlate with increasing radius of gyration without an increase in maximum particle dimension, indicating decreasing protein density. The models for the highest oleic acid content BAMLET indicate an unusual coiled elongated structure that contrasts with apo-α-lactalbumin at pH 12, which is an elongated globular molecule, suggesting that oleic acid inhibits the folding or collapse of the protein component of BAMLET to the globular form. Circular dichroism of BAMLET and apo-α-lactalbumin was performed and the results suggest that α-lactalbumin and BAMLET unfold in a continuum of increasing degree of unfolded states. Taken together, these results support a model in which BAMLET retains oleic acid by non-specific association in the core of partially unfolded protein, and represent a new type of lipoprotein structure.
Collapse
Affiliation(s)
- Emma M Rath
- Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, 2006, Australia
| | | | | | | | | |
Collapse
|
13
|
Antonijevic T, Lancaster JL, Starobin JM. Modeling order-disorder transition in Low-Density Lipoprotein. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2014; 2014:5220-5223. [PMID: 25571170 DOI: 10.1109/embc.2014.6944802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Low Density Lipoproteins (LDL) undergo a reversible order-disorder thermal transition close to biological temperature due to cooperative melting of the cholesteryl esters (CE) in the core of the LDL particle. We have noticed that chain-chain interactions between CE molecules are responsible for the stability of the ordered smectic phase; thus, we formulated a simple "coarse-grained" two-state model to describe the melting process. In this model only nearest neighbor interactions are allowed. On the basis of these assumptions we performed Metropolis Monte Carlo (MC) simulation in order to obtain the heat capacity curve. The resulting profile reveals well-known features of the systems with a finite size.
Collapse
|
14
|
Jayaraman S, Jasuja R, Zakharov MN, Gursky O. Pressure perturbation calorimetry of lipoproteins reveals an endothermic transition without detectable volume changes. Implications for adsorption of apolipoprotein to a phospholipid surface. Biochemistry 2011; 50:3919-27. [PMID: 21452855 DOI: 10.1021/bi200090y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Plasma lipoproteins are assemblies of lipids and apolipoproteins that mediate lipid transport and metabolism. High-density lipoproteins (HDL) remove excess cell cholesterol and provide protection against atherosclerosis. Important aspects of metabolic HDL remodeling, including apolipoprotein dissociation and lipoprotein fusion, are mimicked in thermal denaturation. We report the first study of the protein-lipid complexes by pressure perturbation calorimetry (PPC) beyond 100 °C. In PPC, volume expansion coefficient α(v)(T) is measured during heating; in proteins, α(v)(T) is dominated by hydration. Calorimetric studies of reconstituted HDL and of human high-density, low-density, and very low-density lipoproteins reveal that apolipoprotein unfolding, dissociation, and lipoprotein fusion are endothermic transitions without detectable volume changes. This may result from the limited applicability of PPC to slow kinetically controlled transitions such as thermal remodeling of lipoproteins and/or from the possibility that this remodeling causes no significant changes in the solvent structure and, hence, may not involve large transient solvent exposure of apolar moieties. Another conclusion is that apolipoprotein A-I in solution adsorbs to the phospholipid surface; protein hydration is preserved upon such adsorption. We posit that adsorption to a phospholipid surface helps recruit free apolipoprotein to the plasma membrane and facilitate HDL biogenesis.
Collapse
Affiliation(s)
- Shobini Jayaraman
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, United States.
| | | | | | | |
Collapse
|
15
|
Liu Y, Atkinson D. Immuno-electron cryo-microscopy imaging reveals a looped topology of apoB at the surface of human LDL. J Lipid Res 2011; 52:1111-1116. [PMID: 21460103 DOI: 10.1194/jlr.m013946] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A single copy of apoB is the sole protein component of human LDL. ApoB is crucial for LDL particle stabilization and is the ligand for LDL receptor, through which cholesterol is delivered to cells. Dysregulation of the pathways of LDL metabolism is well documented in the pathophysiology of atherosclerosis. However, an understanding of the structure of LDL and apoB underlying these biological processes remains limited. In this study, we derived a 22 Å-resolution three-dimensional (3D) density map of LDL using cryo-electron microscopy and image reconstruction, which showed a backbone of high-density regions that encircle the LDL particle. Additional high-density belts complemented this backbone high density to enclose the edge of the LDL particle. Image reconstructions of monoclonal antibody-labeled LDL located six epitopes in five putative domains of apoB in 3D. Epitopes in the LDL receptor binding domain were located on one side of the LDL particle, and epitopes in the N-terminal and C-terminal domains of apoB were in close proximity at the front side of the particle. Such image information revealed a looped topology of apoB on the LDL surface and demonstrated the active role of apoB in maintaining the shape of the LDL particle.
Collapse
Affiliation(s)
- Yuhang Liu
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118
| | - David Atkinson
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118.
| |
Collapse
|
16
|
Prassl R. Human low density lipoprotein: the mystery of core lipid packing. J Lipid Res 2010; 52:187-8. [PMID: 21131533 DOI: 10.1194/jlr.e013417] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Ruth Prassl
- Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, Graz, Austria.
| |
Collapse
|