1
|
Chew BLA, Ngoh ANQ, Phoo WW, Chan KWK, Ser Z, Tulsian NK, Lim SS, Weng MJG, Watanabe S, Choy MM, Low J, Ooi EE, Ruedl C, Sobota RM, Vasudevan SG, Luo D. Secreted dengue virus NS1 from infection is predominantly dimeric and in complex with high-density lipoprotein. eLife 2024; 12:RP90762. [PMID: 38787378 PMCID: PMC11126310 DOI: 10.7554/elife.90762] [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] [Indexed: 05/25/2024] Open
Abstract
Severe dengue infections are characterized by endothelial dysfunction shown to be associated with the secreted nonstructural protein 1 (sNS1), making it an attractive vaccine antigen and biotherapeutic target. To uncover the biologically relevant structure of sNS1, we obtained infection-derived sNS1 (isNS1) from dengue virus (DENV)-infected Vero cells through immunoaffinity purification instead of recombinant sNS1 (rsNS1) overexpressed in insect or mammalian cell lines. We found that isNS1 appeared as an approximately 250 kDa complex of NS1 and ApoA1 and further determined the cryoEM structures of isNS1 and its complex with a monoclonal antibody/Fab. Indeed, we found that the major species of isNS1 is a complex of the NS1 dimer partially embedded in a high-density lipoprotein (HDL) particle. Crosslinking mass spectrometry studies confirmed that the isNS1 interacts with the major HDL component ApoA1 through interactions that map to the NS1 wing and hydrophobic domains. Furthermore, our studies demonstrated that the sNS1 in sera from DENV-infected mice and a human patient form a similar complex as isNS1. Our results report the molecular architecture of a biological form of sNS1, which may have implications for the molecular pathogenesis of dengue.
Collapse
Affiliation(s)
- Bing Liang Alvin Chew
- Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore
- NTU Institute of Structural Biology, Nanyang Technological UniversitySingaporeSingapore
| | - AN Qi Ngoh
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
| | - Wint Wint Phoo
- Functional Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and ResearchSingaporeSingapore
| | - Kitti Wing Ki Chan
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
| | - Zheng Ser
- Functional Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and ResearchSingaporeSingapore
| | - Nikhil K Tulsian
- Department of Biological Sciences, National University of SingaporeSingaporeSingapore
- Singapore Centre for Life Sciences, Department of Biochemistry, National University of SingaporeSingaporeSingapore
| | - Shiao See Lim
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
| | - Mei Jie Grace Weng
- Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore
- NTU Institute of Structural Biology, Nanyang Technological UniversitySingaporeSingapore
| | - Satoru Watanabe
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
| | - Milly M Choy
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
| | - Jenny Low
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
- Department of Infectious Diseases, Singapore General HospitalSingaporeSingapore
| | - Eng Eong Ooi
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
- Yong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
- Saw Swee Hock School of Public Health, National University of SingaporeSingaporeSingapore
| | - Christiane Ruedl
- School of Biological Sciences, Nanyang Technological UniversitySingaporeSingapore
| | - Radoslaw M Sobota
- Functional Proteomics Laboratory, Institute of Molecular and Cell Biology, Agency for Science, Technology and ResearchSingaporeSingapore
| | - Subhash G Vasudevan
- Program in Emerging Infectious Diseases, Duke-NUS Medical SchoolSingaporeSingapore
- Department of Microbiology and Immunology, National University of SingaporeSingaporeSingapore
- Institute for Glycomics (G26), Griffith University Gold Coast CampusSouthportAustralia
| | - Dahai Luo
- Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore
- NTU Institute of Structural Biology, Nanyang Technological UniversitySingaporeSingapore
| |
Collapse
|
2
|
Niemelä A, Koivuniemi A. Systematic evaluation of lecithin:cholesterol acyltransferase binding sites in apolipoproteins via peptide based nanodiscs: regulatory role of charged residues at positions 4 and 7. PLoS Comput Biol 2024; 20:e1012137. [PMID: 38805510 PMCID: PMC11161081 DOI: 10.1371/journal.pcbi.1012137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 06/07/2024] [Accepted: 05/05/2024] [Indexed: 05/30/2024] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) exhibits α-activity on high-density and β-activity on low-density lipoproteins. However, the molecular determinants governing LCAT activation by different apolipoproteins remain elusive. Uncovering these determinants would offer the opportunity to design and explore advanced therapies against dyslipidemias. Here, we have conducted coarse-grained and all-atom molecular dynamics simulations of LCAT with nanodiscs made with α-helical amphiphilic peptides either derived from apolipoproteins A1 and E (apoA1 and apoE) or apoA1 mimetic peptide 22A that was optimized to activate LCAT. This study aims to explore what drives the binding of peptides to our previously identified interaction site in LCAT. We hypothesized that this approach could be used to screen for binding sites of LCAT in different apolipoproteins and would provide insights to differently localized LCAT activities. Our screening approach was able to discriminate apoA1 helixes 4, 6, and 7 as key contributors to the interaction with LCAT supporting the previous research data. The simulations provided detailed molecular determinants driving the interaction with LCAT: the formation of hydrogen bonds or salt bridges between peptides E4 or D4 and LCAT S236 or K238 residues. Additionally, salt bridging between R7 and D73 was observed, depending on the availability of R7. Expanding our investigation to diverse plasma proteins, we detected novel LCAT binding helixes in apoL1, apoB100, and serum amyloid A. Our findings suggest that the same binding determinants, involving E4 or D4 -S236 and R7-D73 interactions, influence LCAT β-activity on low-density lipoproteins, where apoE and or apoB100 are hypothesized to interact with LCAT.
Collapse
Affiliation(s)
- Akseli Niemelä
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Artturi Koivuniemi
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| |
Collapse
|
3
|
Strickland MR, Rau MJ, Summers B, Basore K, Wulf J, Jiang H, Chen Y, Ulrich JD, Randolph GJ, Zhang R, Fitzpatrick JAJ, Cashikar AG, Holtzman DM. Apolipoprotein E secreted by astrocytes forms antiparallel dimers in discoidal lipoproteins. Neuron 2024; 112:1100-1109.e5. [PMID: 38266643 PMCID: PMC10994765 DOI: 10.1016/j.neuron.2023.12.018] [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: 09/11/2023] [Revised: 11/24/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
The Apolipoprotein E gene (APOE) is of great interest due to its role as a risk factor for late-onset Alzheimer's disease. ApoE is secreted by astrocytes in the central nervous system in high-density lipoprotein (HDL)-like lipoproteins. Structural models of lipidated ApoE of high resolution could aid in a mechanistic understanding of how ApoE functions in health and disease. Using monoclonal Fab and F(ab')2 fragments, we characterize the structure of lipidated ApoE on astrocyte-secreted lipoproteins. Our results provide support for the "double-belt" model of ApoE in nascent discoidal HDL-like lipoproteins, where two ApoE proteins wrap around the nanodisc in an antiparallel conformation. We further show that lipidated, recombinant ApoE accurately models astrocyte-secreted ApoE lipoproteins. Cryogenic electron microscopy of recombinant lipidated ApoE further supports ApoE adopting antiparallel dimers in nascent discoidal lipoproteins.
Collapse
Affiliation(s)
| | - Michael J Rau
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Brock Summers
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Katherine Basore
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - John Wulf
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Hong Jiang
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Yun Chen
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Department of Pathology and Immunology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Jason D Ulrich
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park Ave., St. Louis, MO 63108, USA
| | - Gwendalyn J Randolph
- Department of Pathology and Immunology, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Rui Zhang
- Department of Biochemistry and Molecular Biophysics, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - Anil G Cashikar
- Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Department of Psychiatry, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Taylor Family institute for Innovative Psychiatric Research, 660 S. Euclid Ave., St. Louis, MO 63110, USA
| | - David M Holtzman
- Department of Neurology, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, 660 S. Euclid Ave., St. Louis, MO 63110, USA; Knight Alzheimer's Disease Research Center, 4488 Forest Park Ave., St. Louis, MO 63108, USA.
| |
Collapse
|
4
|
He Y, Pavanello C, Hutchins PM, Tang C, Pourmousa M, Vaisar T, Song HD, Pastor RW, Remaley AT, Goldberg IJ, Costacou T, Sean Davidson W, Bornfeldt KE, Calabresi L, Segrest JP, Heinecke JW. Flipped C-Terminal Ends of APOA1 Promote ABCA1-Dependent Cholesterol Efflux by Small HDLs. Circulation 2024; 149:774-787. [PMID: 38018436 PMCID: PMC10913861 DOI: 10.1161/circulationaha.123.065959] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 11/05/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND Cholesterol efflux capacity (CEC) predicts cardiovascular disease independently of high-density lipoprotein (HDL) cholesterol levels. Isolated small HDL particles are potent promoters of macrophage CEC by the ABCA1 (ATP-binding cassette transporter A1) pathway, but the underlying mechanisms are unclear. METHODS We used model system studies of reconstituted HDL and plasma from control and lecithin-cholesterol acyltransferase (LCAT)-deficient subjects to investigate the relationships among the sizes of HDL particles, the structure of APOA1 (apolipoprotein A1) in the different particles, and the CECs of plasma and isolated HDLs. RESULTS We quantified macrophage and ABCA1 CEC of 4 distinct sizes of reconstituted HDL. CEC increased as particle size decreased. Tandem mass spectrometric analysis of chemically cross-linked peptides and molecular dynamics simulations of APOA1, the major protein of HDL, indicated that the mobility of C-terminus of that protein was markedly higher and flipped off the surface in the smallest particles. To explore the physiological relevance of the model system studies, we isolated HDL from LCAT-deficient subjects, whose small HDLs (like reconstituted HDLs) are discoidal and composed of APOA1, cholesterol, and phospholipid. Despite their very low plasma levels of HDL particles, these subjects had normal CEC. In both the LCAT-deficient subjects and control subjects, the CEC of isolated extra-small HDL (a mixture of extra-small and small HDL by calibrated ion mobility analysis) was 3- to 5-fold greater than that of the larger sizes of isolated HDL. Incubating LCAT-deficient plasma and control plasma with human LCAT converted extra-small and small HDL particles into larger particles, and it markedly inhibited CEC. CONCLUSIONS We present a mechanism for the enhanced CEC of small HDLs. In smaller particles, the C-termini of the 2 antiparallel molecules of APOA1 are "flipped" off the lipid surface of HDL. This extended conformation allows them to engage with ABCA1. In contrast, the C-termini of larger HDLs are unable to interact productively with ABCA1 because they form a helical bundle that strongly adheres to the lipid on the particle. Enhanced CEC, as seen with the smaller particles, predicts decreased cardiovascular disease risk. Thus, extra-small and small HDLs may be key mediators and indicators of the cardioprotective effects of HDL.
Collapse
Affiliation(s)
- Yi He
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| | - Chiara Pavanello
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Italy (C.P., L.C.)
| | - Patrick M. Hutchins
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| | - Chongren Tang
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| | - Mohsen Pourmousa
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute (M.P., R.W.P.), National Institutes of Health, Bethesda, MD
| | - Tomas Vaisar
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| | - Hyun D. Song
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (H.D.S., J.P.S.)
| | - Richard W. Pastor
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute (M.P., R.W.P.), National Institutes of Health, Bethesda, MD
| | - Alan T. Remaley
- Department of Laboratory Medicine (A.T.R.), National Institutes of Health, Bethesda, MD
| | - Ira J. Goldberg
- Department of Medicine, New York University, New York, NY (I.J.G.)
| | - Tina Costacou
- Department of Epidemiology, University of Pittsburgh, PA (T.C.)
| | - W. Sean Davidson
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, OH (W.S.D.)
| | - Karin E. Bornfeldt
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| | - Laura Calabresi
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Italy (C.P., L.C.)
| | - Jere P. Segrest
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN (H.D.S., J.P.S.)
| | - Jay W. Heinecke
- Department of Medicine, University of Washington, Seattle (Y.H., P.M.H., C.T., T.V., K.E.B., J.W.H.)
| |
Collapse
|
5
|
He Y, Pavanello C, Hutchins PM, Tang C, Pourmousa M, Vaisar T, Song HD, Pastor RW, Remaley AT, Goldberg IJ, Costacou T, Davidson WS, Bornfeldt KE, Calabresi L, Segrest JP, Heinecke JW. Flipped C-Terminal Ends of APOA1 Promote ABCA1-dependent Cholesterol Efflux by Small HDLs. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.03.23297986. [PMID: 37961344 PMCID: PMC10635269 DOI: 10.1101/2023.11.03.23297986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Background Cholesterol efflux capacity (CEC) predicts cardiovascular disease (CVD) independently of HDL cholesterol (HDL-C) levels. Isolated small HDL particles are potent promoters of macrophage CEC by the ABCA1 pathway, but the underlying mechanisms are unclear. Methods We used model system studies of reconstituted HDL and plasma from control and lecithin-cholesterol acyltransferase (LCAT)-deficient subjects to investigate the relationships among the sizes of HDL particles, the structure of APOA1 in the different particles, and the CECs of plasma and isolated HDLs. Results We quantified macrophage and ABCA1 CEC of four distinct sizes of reconstituted HDL (r-HDL). CEC increased as particle size decreased. MS/MS analysis of chemically crosslinked peptides and molecular dynamics simulations of APOA1 (HDL's major protein) indicated that the mobility of that protein's C-terminus was markedly higher and flipped off the surface in the smallest particles. To explore the physiological relevance of the model system studies, we isolated HDL from LCAT-deficient subjects, whose small HDLs-like r-HDLs-are discoidal and composed of APOA1, cholesterol, and phospholipid. Despite their very low plasma levels of HDL particles, these subjects had normal CEC. In both the LCAT-deficient subjects and control subjects, the CEC of isolated extra-small HDL (a mixture of extra-small and small HDL by calibrated ion mobility analysis) was 3-5-fold greater than that of the larger sizes of isolated HDL. Incubating LCAT-deficient plasma and control plasma with human LCAT converted extra-small and small HDL particles into larger particles, and it markedly inhibited CEC. Conclusions We present a mechanism for the enhanced CEC of small HDLs. In smaller particles, the C-termini of the two antiparallel molecules of APOA1 are flipped off the lipid surface of HDL. This extended conformation allows them to engage with ABCA1. In contrast, the C-termini of larger HDLs are unable to interact productively with ABCA1 because they form a helical bundle that strongly adheres to the lipid on the particle. Enhanced CEC, as seen with the smaller particles, predicts decreased CVD risk. Thus, extra-small and small HDLs may be key mediators and indicators of HDL's cardioprotective effects.
Collapse
Affiliation(s)
- Yi He
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Chiara Pavanello
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Patrick M Hutchins
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Chongren Tang
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Mohsen Pourmousa
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Tomas Vaisar
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Hyun D Song
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37240, USA
| | - Richard W Pastor
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Alan T Remaley
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD 20892
| | - Ira J Goldberg
- Department of Medicine, New York University, New York, NY, 10016, USA
| | - Tina Costacou
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - W Sean Davidson
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, 45237, USA
| | - Karin E Bornfeldt
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Laura Calabresi
- Centro Grossi Paoletti, Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, Italy
| | - Jere P Segrest
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37240, USA
| | - Jay W Heinecke
- Department of Medicine, University of Washington, Seattle, WA, 98109, USA
| |
Collapse
|
6
|
Sacher S, Mukherjee A, Ray A. Deciphering structural aspects of reverse cholesterol transport: mapping the knowns and unknowns. Biol Rev Camb Philos Soc 2023; 98:1160-1183. [PMID: 36880422 DOI: 10.1111/brv.12948] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 02/03/2023] [Accepted: 02/24/2023] [Indexed: 03/08/2023]
Abstract
Atherosclerosis is a major contributor to the onset and progression of cardiovascular disease (CVD). Cholesterol-loaded foam cells play a pivotal role in forming atherosclerotic plaques. Induction of cholesterol efflux from these cells may be a promising approach in treating CVD. The reverse cholesterol transport (RCT) pathway delivers cholesteryl ester (CE) packaged in high-density lipoproteins (HDL) from non-hepatic cells to the liver, thereby minimising cholesterol load of peripheral cells. RCT takes place via a well-organised interplay amongst apolipoprotein A1 (ApoA1), lecithin cholesterol acyltransferase (LCAT), ATP binding cassette transporter A1 (ABCA1), scavenger receptor-B1 (SR-B1), and the amount of free cholesterol. Unfortunately, modulation of RCT for treating atherosclerosis has failed in clinical trials owing to our lack of understanding of the relationship between HDL function and RCT. The fate of non-hepatic CEs in HDL is dependent on their access to proteins involved in remodelling and can be regulated at the structural level. An inadequate understanding of this inhibits the design of rational strategies for therapeutic interventions. Herein we extensively review the structure-function relationships that are essential for RCT. We also focus on genetic mutations that disturb the structural stability of proteins involved in RCT, rendering them partially or completely non-functional. Further studies are necessary for understanding the structural aspects of RCT pathway completely, and this review highlights alternative theories and unanswered questions.
Collapse
Affiliation(s)
- Sukriti Sacher
- Department of Computational Biology, Indraprastha Institute of Information Technology, Okhla Phase III, New Delhi, 110019, India
| | - Abhishek Mukherjee
- Dhiti Life Sciences Pvt Ltd, B-107, Okhla Phase I, New Delhi, 110020, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, Okhla Phase III, New Delhi, 110019, India
| |
Collapse
|
7
|
Kalbitzer T, Lobenhofer K, Martin S, Beck Erlach M, Kremer W, Kalbitzer HR. NMR derived changes of lipoprotein particle concentrations related to impaired fasting glucose, impaired glucose tolerance, or manifest type 2 diabetes mellitus. Lipids Health Dis 2023; 22:42. [PMID: 36964528 PMCID: PMC10037821 DOI: 10.1186/s12944-023-01801-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 03/06/2023] [Indexed: 03/26/2023] Open
Abstract
Background Type 2 diabetes mellitus (T2D) and corresponding borderline states, impaired fasting glucose (IFG) and/or glucose tolerance (IGT), are associated with dyslipoproteinemia. It is important to distinguish between factors that cause T2D and that are the direct result of T2D. Methods The lipoprotein subclass patterns of blood donors with IFG, IGT, with IFG combined with IGT, and T2D are analyzed by nuclear magnetic resonance (NMR) spectroscopy. The development of lipoprotein patterns with time is investigated by using samples retained for an average period of 6 years. In total 595 blood donors are classified by oral glucose tolerance test (oGTT) and their glycosylated hemoglobin (HbA1c) concentrations. Concentrations of lipoprotein particles of 15 different subclasses are analyzed in the 10,921 NMR spectra recorded under fasting and non-fasting conditions. The subjects are assumed healthy according to the strict regulations for blood donors before performing the oGTT. Results Under fasting conditions manifest T2D exhibits a significant concentration increase of the smallest HDL particles (HDL A) combined with a decrease in all other HDL subclasses. In contrast to other studies reviewed in this paper, a general concentration decrease of all LDL particles is observed that is most prominent for the smallest LDL particles (LDL A). Under normal nutritional conditions a large, significant increase of the concentrations of VLDL and chylomicrons is observed for all groups with IFG and/or IGT and most prominently for manifest T2D. As we show it is possible to obtain an estimate of the concentrations of the apolipoproteins Apo-A1, Apo-B100, and Apo-B48 from the NMR data. In the actual study cohort, under fasting conditions the concentrations of the lipoproteins are not increased significantly in T2D, under non-fasting conditions only Apo-B48 increases significantly. Conclusion In contrast to other studies, in our cohort of “healthy” blood donors the T2D associated dyslipoproteinemia does not change the total concentrations of the lipoprotein particles produced in the liver under fasting and non-fasting conditions significantly but only their subclass distributions. Compared to the control group, under non-fasting conditions participants with IGT and IFG or T2D show a substantial increase of plasma concentrations of those lipoproteins that are produced in the intestinal tract. The intestinal insulin resistance becomes strongly observable.
Collapse
Affiliation(s)
- Tina Kalbitzer
- grid.7727.50000 0001 2190 5763Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany
| | - Kristina Lobenhofer
- grid.7727.50000 0001 2190 5763Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany
| | - Silke Martin
- Blutspendedienst des Bayerischen Roten Kreuzes Gemeinnützige GmbH, Herzog-Heinrich-Straße 2, 80336 Munich, Germany
| | - Markus Beck Erlach
- grid.7727.50000 0001 2190 5763Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany
| | - Werner Kremer
- grid.7727.50000 0001 2190 5763Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany
| | - Hans Robert Kalbitzer
- grid.7727.50000 0001 2190 5763Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, Universitätsstr. 31, 93040 Regensburg, Germany
| |
Collapse
|
8
|
Chandrasekhar G, Chandra Sekar P, Srinivasan E, Amarnath A, Pengyong H, Rajasekaran R. Molecular simulation unravels the amyloidogenic misfolding of nascent ApoA1 protein, driven by deleterious point mutations occurring in between 170-178 hotspot region. J Biomol Struct Dyn 2022; 40:13278-13290. [PMID: 34613891 DOI: 10.1080/07391102.2021.1986134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Protein ApoA1 is extensively studied for its role in lipid metabolism. Its seedy dark side of amyloid formulation remains relatively understudied yet. Due to genetic mutations, the protein pathologically misshapes into its amyloid form that gets accumulated in various organs, including the heart. To contrive effective therapeutics against this debilitating congenital disorder, it is imperative to comprehend the structural ramifications induced by mutations in APoA1's dynamic conformation. Till now, several point mutations have been implicated in ApoA1's amyloidosis, although only a handful has been examined considerably. Especially, the single nucleotide polymorphisms (SNPs) that occur in-between 170-178 mutation hotspot site of APoA1 needs to be investigated, since most of them are culpable of amyloid deposition in the heart. To that effect, in the present study, we have computationally quantified and studied the ApoA1's biomolecular modifications fostered by SNPs in the 170-178 mutation hotspot. Findings from discrete molecular dynamics simulation studies indicate that the SNPs have noticeably steered the ApoA1's behaviour from its native structural dynamics. Analysis of protein's secondary structural changes exhibits a considerable change upon mutations. Further, subjecting the protein structures to simulated thermal denaturation shows increased resistance to denaturation among mutants when compared to native. Further, normal mode analysis of protein's dynamic motion also shows discrepancy in its dynamic structural change upon SNP. These structural digressions induced by SNPs can very well be the biomolecular incendiary that drives ApoA1 into its amyloidogenesis. And, understanding these structural modifications initiates a better understanding of SNP's amyloidogenic pathology on APoA1.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- G Chandrasekhar
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, Tamil Nadu, India
| | - P Chandra Sekar
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, Tamil Nadu, India
| | - E Srinivasan
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, Tamil Nadu, India
| | - A Amarnath
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, Tamil Nadu, India
| | - H Pengyong
- Central Lab, Changzhi Medical College, Changzhi, China
| | - R Rajasekaran
- Bioinformatics Lab, Department of Biotechnology, School of Bio Sciences and Technology, Vellore Institute of Technology (Deemed to be University), Vellore, Tamil Nadu, India
| |
Collapse
|
9
|
Melchior JT, Street SE, Vaisar T, Hart R, Jerome J, Kuklenyik Z, Clouet-Foraison N, Thornock C, Bedi S, Shah AS, Segrest JP, Heinecke JW, Davidson WS. Apolipoprotein A-I modulates HDL particle size in the absence of apolipoprotein A-II. J Lipid Res 2021; 62:100099. [PMID: 34324889 PMCID: PMC8385444 DOI: 10.1016/j.jlr.2021.100099] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/01/2021] [Accepted: 07/15/2021] [Indexed: 11/30/2022] Open
Abstract
Human high-density lipoproteins (HDL) are a complex mixture of structurally-related nanoparticles that perform distinct physiological functions. We previously showed human HDL containing apolipoprotein A-I (APOA1) but not apolipoprotein A-II (APOA2), designated LpA-I, is composed primarily of two discretely sized populations. Here, we isolated these particles directly from human plasma by antibody affinity chromatography, separated them by high-resolution size exclusion chromatography and performed a deep molecular characterization of each species. The large and small LpA-I populations were spherical with mean diameters of 109 Å and 91 Å, respectively. Unexpectedly, isotope dilution MS/MS with [15N]-APOA1 in concert with quantitation of particle concentration by calibrated ion mobility analysis demonstrated that the large particles contained fewer APOA1 molecules than the small particles; the stoichiometries were 3.0 and 3.7 molecules of APOA1 per particle, respectively. MS/MS experiments showed that the protein cargo of large LpA-I particles was more diverse. Human HDL and isolated particles containing both APOA1 and APOA2 exhibit a much wider range and variation of particle sizes than LpA-I, indicating that APOA2 is likely the major contributor to HDL size heterogeneity. We propose a ratchet model based on the trefoil structure of APOA1 whereby the helical cage maintaining particle structure has two 'settings' - large and small - that accounts for these findings. This understanding of the determinants of HDL particle size and protein cargo distribution serves as a basis for determining the roles of HDL subpopulations in metabolism and disease states.
Collapse
Affiliation(s)
- John T Melchior
- Center for Lipid and Arteriosclerosis Science, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237; Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, 99354
| | - Scott E Street
- Center for Lipid and Arteriosclerosis Science, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237
| | - Tomas Vaisar
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98109
| | - Rachel Hart
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Jay Jerome
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Zsuzsanna Kuklenyik
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341
| | - Noemie Clouet-Foraison
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98109
| | - Carissa Thornock
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98109
| | - Shimpi Bedi
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, 99354
| | - Amy S Shah
- Division of Endocrinology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center and University of Cincinnati, Cincinnati, Ohio 45229
| | - Jere P Segrest
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232
| | - Jay W Heinecke
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98109
| | - W Sean Davidson
- Center for Lipid and Arteriosclerosis Science, Department of Pathology and Laboratory Medicine, University of Cincinnati, Cincinnati, Ohio 45237.
| |
Collapse
|
10
|
Wolkowicz P, White CR, Anantharamaiah GM. Apolipoprotein Mimetic Peptides: An Emerging Therapy against Diabetic Inflammation and Dyslipidemia. Biomolecules 2021; 11:biom11050627. [PMID: 33922449 PMCID: PMC8146922 DOI: 10.3390/biom11050627] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 04/15/2021] [Accepted: 04/16/2021] [Indexed: 12/12/2022] Open
Abstract
Obesity has achieved epidemic status in the United States, resulting in an increase in type 2 diabetes mellitus, dyslipidemia, and cardiovascular disease. Numerous studies have shown that inflammation plays a key role in the development of insulin resistance and diabetic complications. HDL cholesterol levels are inversely associated with coronary heart disease in humans. The beneficial effect of HDL is due, in part, to apolipoproteins A-I and E, which possess anti-inflammatory properties. The functional quality of HDL, however, may be reduced in the context of diabetes. Thus, raising levels of functional HDL is an important target for reducing inflammation and diabetic complications. Apo A-I possesses eight alpha-helical sequences, most of which form class A amphipathic helical structures. Peptides belonging to this class inhibit atherogenesis in several mouse models. Additional peptides based on structural components of apoE have been shown to mediate a rapid clearance of atherogenic lipoproteins in dyslipidemic mice. In this review, we discuss the efficacy of apolipoprotein mimetic peptides in improving lipoprotein function, reducing inflammation, and reversing insulin resistance and cardiometabolic disease processes in diabetic animals.
Collapse
|
11
|
Ushio N, Chambers JK, Watanabe K, Kayano M, Uchida K. Age-Related Arteriolar Changes With Lipid and Amyloid Deposits in the Gonads of Dogs. Vet Pathol 2021; 58:558-567. [PMID: 33686886 DOI: 10.1177/0300985821996670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Arteriolar lesions with lipid and/or amyloid deposits are frequently detected in canine gonads by routine histopathologic examination; however, they have never been examined in detail. In the present study, a total of 139 testes/epididymides and 200 ovaries from 72 male (4 months to 14 years old) and 105 female (7 months to 16 years old) dogs were examined for arteriolar lesions. Arteriolar lesions were detected in 21 of 72 male dogs (29%) and 54 of 105 female dogs (51%). These lesions were histologically classified into 4 types: "fibromuscular hypertrophy," characterized by thickening of the tunica intima; "focal vasculitis," characterized by mononuclear cell infiltration; "vacuolar change," consisting of lipid accumulation and infiltration of foamy cells; and "hyalinosis," characterized by irregular thickening with amyloid deposits. In the lesions of vacuolar change and hyalinosis, lipid deposition and infiltration of α-SMA-positive cells and Iba-1-positive cells were also observed. Foamy cells and amyloid deposits were immunopositive for apolipoproteins and oxidized low-density lipoprotein-related proteins. These results indicate that vacuolar change is possibly an early stage of atherosclerosis, and that amyloid may deposit as a consequence of the microenvironment associated with atherogenesis. Logistic regression analysis revealed that arteriolar lesions with lipid deposits were associated with age and interstitial cell tumors in male dogs, and with age in female dogs. Aging is likely an important risk factor of arteriolar lesions with lipid deposits of the canine gonads.
Collapse
Affiliation(s)
| | | | - Kenichi Watanabe
- 52746Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Mitsunori Kayano
- 52746Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | | |
Collapse
|
12
|
Harvey SR, VanAernum ZL, Kostelic MM, Marty MT, Wysocki VH. Probing the structure of nanodiscs using surface-induced dissociation mass spectrometry. Chem Commun (Camb) 2020; 56:15651-15654. [PMID: 33355562 PMCID: PMC7943047 DOI: 10.1039/d0cc05531j] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In the study of membrane proteins and antimicrobial peptides, nanodiscs have emerged as a valuable membrane mimetic to solubilze these molecules in a lipid bilayer. We present the structural characterization of nanodiscs using native mass spectrometry and surface-induced dissociation, which are powerful tools in structural biology.
Collapse
Affiliation(s)
- Sophie R Harvey
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH, USA.
| | | | | | | | | |
Collapse
|
13
|
Sligar SG, Denisov IG. Nanodiscs: A toolkit for membrane protein science. Protein Sci 2020; 30:297-315. [PMID: 33165998 DOI: 10.1002/pro.3994] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/25/2022]
Abstract
Membrane proteins are involved in numerous vital biological processes, including transport, signal transduction and the enzymes in a variety of metabolic pathways. Integral membrane proteins account for up to 30% of the human proteome and they make up more than half of all currently marketed therapeutic targets. Unfortunately, membrane proteins are inherently recalcitrant to study using the normal toolkit available to scientists, and one is most often left with the challenge of finding inhibitors, activators and specific antibodies using a denatured or detergent solubilized aggregate. The Nanodisc platform circumvents these challenges by providing a self-assembled system that renders typically insoluble, yet biologically and pharmacologically significant, targets such as receptors, transporters, enzymes, and viral antigens soluble in aqueous media in a native-like bilayer environment that maintain a target's functional activity. By providing a bilayer surface of defined composition and structure, Nanodiscs have found great utility in the study of cellular signaling complexes that assemble on a membrane surface. Nanodiscs provide a nanometer scale vehicle for the in vivo delivery of amphipathic drugs, therapeutic lipids, tethered nucleic acids, imaging agents and active protein complexes. This means for generating nanoscale lipid bilayers has spawned the successful use of numerous other polymer and peptide amphipathic systems. This review, in celebration of the Anfinsen Award, summarizes some recent results and provides an inroad into the current and historical literature.
Collapse
Affiliation(s)
- Stephen G Sligar
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
| | - Ilia G Denisov
- Departments of Biochemistry Chemistry, University of Illinois, Urbana-Champaign, Urbana, Illinois, USA
| |
Collapse
|
14
|
Ludovico ID, Gisonno RA, Gonzalez MC, Garda HA, Ramella NA, Tricerri MA. Understanding the role of apolipoproteinA-I in atherosclerosis. Post-translational modifications synergize dysfunction? Biochim Biophys Acta Gen Subj 2020; 1865:129732. [PMID: 32946930 DOI: 10.1016/j.bbagen.2020.129732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/17/2020] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND The identification of dysfunctional human apolipoprotein A-I (apoA-I) in atherosclerotic plaques suggests that protein structure and function may be hampered under a chronic pro inflammatory scenario. Moreover, the fact that natural mutants of this protein elicit severe cardiovascular diseases (CVD) strongly indicates that the native folding could shift due to the mutation, yielding a structure more prone to misfold or misfunction. To understand the events that determine the failure of apoA-I structural flexibility to fulfill its protective role, we took advantage of the study of a natural variant with a deletion of the residue lysine 107 (K107del) associated with atherosclerosis. METHODS Biophysical approaches, such as electrophoresis, fluorescence and spectroscopy were used to characterize proteins structure and function, either in native conformation or under oxidation or intramolecular crosslinking. RESULTS K107del structure was more flexible than the protein with the native sequence (Wt) but interactions with artificial membranes were preserved. Instead, structural restrictions by intramolecular crosslinking impaired the Wt and K107del lipid solubilization function. In addition, controlled oxidation decreased the yield of the native dimer conformation for both variants. CONCLUSIONS We conclude that even though mutations may alter protein structure and spatial arrangement, the highly flexible conformation compensates the mild shift from the native folding. Instead, post translational apoA-I modifications (probably chronic and progressive) are required to raise a protein conformation with significant loss of function and increased aggregation tendency. GENERAL SIGNIFICANCE The results learnt from this variant strength a close association between amyloidosis and atherosclerosis.
Collapse
Affiliation(s)
- Ivo Díaz Ludovico
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina
| | - Romina A Gisonno
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina
| | - Marina C Gonzalez
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina
| | - Horacio A Garda
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina
| | - Nahuel A Ramella
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina.
| | - M Alejandra Tricerri
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Argentina; Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, La Plata CP 1900, Argentina.
| |
Collapse
|
15
|
Structural analysis of lecithin:cholesterol acyltransferase bound to high density lipoprotein particles. Commun Biol 2020; 3:28. [PMID: 31942029 PMCID: PMC6962161 DOI: 10.1038/s42003-019-0749-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 12/17/2019] [Indexed: 02/07/2023] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) catalyzes a critical step of reverse cholesterol transport by esterifying cholesterol in high density lipoprotein (HDL) particles. LCAT is activated by apolipoprotein A-I (ApoA-I), which forms a double belt around HDL, however the manner in which LCAT engages its lipidic substrates and ApoA-I in HDL is poorly understood. Here, we used negative stain electron microscopy, crosslinking, and hydrogen-deuterium exchange studies to refine the molecular details of the LCAT-HDL complex. Our data are consistent with LCAT preferentially binding to the edge of discoidal HDL near the boundary between helix 5 and 6 of ApoA-I in a manner that creates a path from the lipid bilayer to the active site of LCAT. Our results provide not only an explanation why LCAT activity diminishes as HDL particles mature, but also direct support for the anti-parallel double belt model of HDL, with LCAT binding preferentially to the helix 4/6 region.
Collapse
|
16
|
Gao D, Ashraf MZ, Zhang L, Kar N, Byzova TV, Podrez EA. Cross-linking modifications of HDL apoproteins by oxidized phospholipids: structural characterization, in vivo detection, and functional implications. J Biol Chem 2020; 295:1973-1984. [PMID: 31907281 DOI: 10.1074/jbc.ra119.008445] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 12/16/2019] [Indexed: 01/05/2023] Open
Abstract
Apolipoprotein A-I (apoA-I) is cross-linked and dysfunctional in human atheroma. Although multiple mechanisms of apoA-I cross-linking have been demonstrated in vitro, the in vivo mechanisms of cross-linking are not well-established. We have recently demonstrated the highly selective and efficient modification of high-density lipoprotein (HDL) apoproteins by endogenous oxidized phospholipids (oxPLs), including γ-ketoalkenal phospholipids. In the current study, we report that γ-ketoalkenal phospholipids effectively cross-link apoproteins in HDL. We further demonstrate that cross-linking impairs the cholesterol efflux mediated by apoA-I or HDL3 in vitro and in vivo Using LC-MS/MS analysis, we analyzed the pattern of apoprotein cross-linking in isolated human HDL either by synthetic γ-ketoalkenal phospholipids or by oxPLs generated during HDL oxidation in plasma by the physiologically relevant MPO-H2O2-NO2 - system. We found that five histidine residues in helices 5-8 of apoA-I are preferably cross-linked by oxPLs, forming stable pyrrole adducts with lysine residues in the helices 3-4 of another apoA-I or in the central domain of apoA-II. We also identified cross-links of apoA-I and apoA-II with two minor HDL apoproteins, apoA-IV and apoE. We detected a similar pattern of apoprotein cross-linking in oxidized murine HDL. We further detected oxPL cross-link adducts of HDL apoproteins in plasma and aorta of hyperlipidemic LDLR-/- mice, including cross-link adducts of apoA-I His-165-apoA-I Lys-93, apoA-I His-154-apoA-I Lys-105, apoA-I His-154-apoA-IV Lys-149, and apoA-II Lys-30-apoE His-227. These findings suggest an important mechanism that contributes to the loss of HDL's atheroprotective function in vivo.
Collapse
Affiliation(s)
- Detao Gao
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Mohammad Z Ashraf
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Lifang Zhang
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Niladri Kar
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Tatiana V Byzova
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195
| | - Eugene A Podrez
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195.
| |
Collapse
|