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Kris-Etherton PM, Riley TM, Petersen KS. Dietary modulation of Lp(a): more questions than answers. J Lipid Res 2024; 65:100592. [PMID: 38996919 DOI: 10.1016/j.jlr.2024.100592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024] Open
Affiliation(s)
- Penny M Kris-Etherton
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, USA
| | - Terrence M Riley
- Nutritional Physiology Lab, Pennington Biomedical Research Center, Baton Rouge, LA, USA
| | - Kristina S Petersen
- Department of Nutritional Sciences, Pennsylvania State University, University Park, PA, USA.
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2
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Lorey MB, Youssef A, Äikäs L, Borrelli M, Hermansson M, Assini JM, Kemppainen A, Ruhanen H, Ruuth M, Matikainen S, Kovanen PT, Käkelä R, Boffa MB, Koschinsky ML, Öörni K. Lipoprotein(a) induces caspase-1 activation and IL-1 signaling in human macrophages. Front Cardiovasc Med 2023; 10:1130162. [PMID: 37293282 PMCID: PMC10244518 DOI: 10.3389/fcvm.2023.1130162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/02/2023] [Indexed: 06/10/2023] Open
Abstract
Introduction Lipoprotein(a) (Lp(a)) is an LDL-like particle with an additional apolipoprotein (apo)(a) covalently attached. Elevated levels of circulating Lp(a) are a risk factor for atherosclerosis. A proinflammatory role for Lp(a) has been proposed, but its molecular details are incompletely defined. Methods and results To explore the effect of Lp(a) on human macrophages we performed RNA sequencing on THP-1 macrophages treated with Lp(a) or recombinant apo(a), which showed that especially Lp(a) induces potent inflammatory responses. Thus, we stimulated THP-1 macrophages with serum containing various Lp(a) levels to investigate their correlations with cytokines highlighted by the RNAseq, showing significant correlations with caspase-1 activity and secretion of IL-1β and IL-18. We further isolated both Lp(a) and LDL particles from three donors and then compared their atheroinflammatory potentials together with recombinant apo(a) in primary and THP-1 derived macrophages. Compared with LDL, Lp(a) induced a robust and dose-dependent caspase-1 activation and release of IL-1β and IL-18 in both macrophage types. Recombinant apo(a) strongly induced caspase-1 activation and IL-1β release in THP-1 macrophages but yielded weak responses in primary macrophages. Structural analysis of these particles revealed that the Lp(a) proteome was enriched in proteins associated with complement activation and coagulation, and its lipidome was relatively deficient in polyunsaturated fatty acids and had a high n-6/n-3 ratio promoting inflammation. Discussion Our data show that Lp(a) particles induce the expression of inflammatory genes, and Lp(a) and to a lesser extent apo(a) induce caspase-1 activation and IL-1 signaling. Major differences in the molecular profiles between Lp(a) and LDL contribute to Lp(a) being more atheroinflammatory.
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Affiliation(s)
- Martina B. Lorey
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Amer Youssef
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Lauri Äikäs
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
| | - Matthew Borrelli
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Martin Hermansson
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
| | - Julia M. Assini
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Aapeli Kemppainen
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
| | - Hanna Ruhanen
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute of Life Science (HiLIFE) and Biocenter Finland, Helsinki, Finland
| | - Maija Ruuth
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
| | - Sampsa Matikainen
- Helsinki Rheumatic Disease and Inflammation Research Group, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Petri T. Kovanen
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
| | - Reijo Käkelä
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Helsinki University Lipidomics Unit (HiLIPID), Helsinki Institute of Life Science (HiLIFE) and Biocenter Finland, Helsinki, Finland
| | - Michael B. Boffa
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
- Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Marlys L. Koschinsky
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Katariina Öörni
- Atherosclerosis Research Laboratory, Wihuri Research Institute, Helsinki, Finland
- Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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Abstract
PURPOSE OF REVIEW This review summarizes our current understanding of the processes of apolipoprotein(a) secretion, assembly of the Lp(a) particle and removal of Lp(a) from the circulation. We also identify existing knowledge gaps that need to be addressed in future studies. RECENT FINDINGS The Lp(a) particle is assembled in two steps: a noncovalent, lysine-dependent interaction of apo(a) with apoB-100 inside hepatocytes, followed by extracellular covalent association between these two molecules to form circulating apo(a).The production rate of Lp(a) is primarily responsible for the observed inverse correlation between apo(a) isoform size and Lp(a) levels, with a contribution of catabolism restricted to larger Lp(a) isoforms.Factors that affect apoB-100 secretion from hepatocytes also affect apo(a) secretion.The identification of key hepatic receptors involved in Lp(a) clearance in vivo remains unclear, with a role for the LDL receptor seemingly restricted to conditions wherein LDL concentrations are low, Lp(a) is highly elevated and LDL receptor number is maximally upregulated. SUMMARY The key role for production rate of Lp(a) [including secretion and assembly of the Lp(a) particle] rather than its catabolic rate suggests that the most fruitful therapies for Lp(a) reduction should focus on approaches that inhibit production of the particle rather than its removal from circulation.
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Affiliation(s)
| | - Marlys L Koschinsky
- Robarts Research Institute
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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4
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Clark JR, Gemin M, Youssef A, Marcovina SM, Prat A, Seidah NG, Hegele RA, Boffa MB, Koschinsky ML. Sortilin enhances secretion of apolipoprotein(a) through effects on apolipoprotein B secretion and promotes uptake of lipoprotein(a). J Lipid Res 2022; 63:100216. [PMID: 35469919 PMCID: PMC9131257 DOI: 10.1016/j.jlr.2022.100216] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 12/30/2022] Open
Abstract
Elevated plasma lipoprotein(a) (Lp(a)) is an independent, causal risk factor for atherosclerotic cardiovascular disease and calcific aortic valve stenosis. Lp(a) is formed in or on hepatocytes from successive noncovalent and covalent interactions between apo(a) and apoB, although the subcellular location of these interactions and the nature of the apoB-containing particle involved remain unclear. Sortilin, encoded by the SORT1 gene, modulates apoB secretion and LDL clearance. We used a HepG2 cell model to study the secretion kinetics of apo(a) and apoB. Overexpression of sortilin increased apo(a) secretion, while siRNA-mediated knockdown of sortilin expression correspondingly decreased apo(a) secretion. Sortilin binds LDL but not apo(a) or Lp(a), indicating that its effect on apo(a) secretion is likely indirect. Indeed, the effect was dependent on the ability of apo(a) to interact noncovalently with apoB. Overexpression of sortilin enhanced internalization of Lp(a), but not apo(a), by HepG2 cells, although neither sortilin knockdown in these cells or Sort1 deficiency in mice impacted Lp(a) uptake. We found several missense mutations in SORT1 in patients with extremely high Lp(a) levels; sortilin containing some of these mutations was more effective at promoting apo(a) secretion than WT sortilin, though no differences were found with respect to Lp(a) internalization. Our observations suggest that sortilin could play a role in determining plasma Lp(a) levels and corroborate in vivo human kinetic studies which imply that secretion of apo(a) and apoB are coupled, likely within the hepatocyte.
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Affiliation(s)
- Justin R Clark
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Matthew Gemin
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Amer Youssef
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | | | - Annik Prat
- Institut de Recherches Cliniques de Montreal, Montréal, QC, Canada
| | - Nabil G Seidah
- Institut de Recherches Cliniques de Montreal, Montréal, QC, Canada
| | - Robert A Hegele
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada; Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada; Department of Medicine, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Michael B Boffa
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada; Department of Biochemistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada
| | - Marlys L Koschinsky
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada; Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, ON, Canada.
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5
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Youssef A, Clark JR, Marcovina SM, Boffa MB, Koschinsky ML. Apo(a) and ApoB Interact Noncovalently Within Hepatocytes: Implications for Regulation of Lp(a) Levels by Modulation of ApoB Secretion. Arterioscler Thromb Vasc Biol 2022; 42:289-304. [PMID: 35045727 DOI: 10.1161/atvbaha.121.317335] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Elevated plasma Lp(a) (lipoprotein(a)) levels are associated with increased risk for atherosclerotic cardiovascular disease and aortic valve stenosis. However, the cell biology of Lp(a) biosynthesis remains poorly understood, with the locations of the noncovalent and covalent steps of Lp(a) assembly unclear and the nature of the apoB-containing particle destined for Lp(a) unknown. We, therefore, asked if apo(a) and apoB interact noncovalently within hepatocytes and if this impacts Lp(a) biosynthesis. METHODS Using human hepatocellular carcinoma cells expressing 17K (17 kringle) apo(a), or a 17KΔLBS7,8 variant with a reduced ability to bind noncovalently to apoB, we performed coimmunoprecipitation, coimmunofluorescence, and proximity ligation assays to document intracellular apo(a):apoB interactions. We used a pulse-chase metabolic labeling approach to measure apo(a) and apoB secretion rates. RESULTS Noncovalent complexes containing apo(a)/apoB are present in lysates from cells expressing 17K but not 17KΔLBS7,8, whereas covalent apo(a)/apoB complexes are absent from lysates. 17K and apoB colocalized intracellularly, overlapping with staining for markers of endoplasmic reticulum trans-Golgi, and early endosomes, and less so with lysosomes. The 17KΔLBS7,8 had lower colocalization with apoB. Proximity ligation assays directly documented intracellular 17K/apoB interactions, which were dramatically reduced for 17KΔLBS7,8. Treatment of cells with PCSK9 (proprotein convertase subtilisin/kexin type 9) enhanced, and lomitapide reduced, apo(a) secretion in a manner dependent on the noncovalent interaction between apo(a) and apoB. Apo(a) secretion was also reduced by siRNA-mediated knockdown of APOB. CONCLUSIONS Our findings explain the coupling of apo(a) and Lp(a)-apoB production observed in human metabolic studies using stable isotopes as well as the ability of agents that inhibit apoB biosynthesis to lower Lp(a) levels.
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Affiliation(s)
- Amer Youssef
- Robarts Research Institute (A.Y., M.B.B., M.L.K.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Justin R Clark
- Department of Physiology & Pharmacology (J.R.C., M.L.K.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | | | - Michael B Boffa
- Robarts Research Institute (A.Y., M.B.B., M.L.K.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada.,Department of Biochemistry (M.B.B.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Marlys L Koschinsky
- Robarts Research Institute (A.Y., M.B.B., M.L.K.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada.,Department of Physiology & Pharmacology (J.R.C., M.L.K.), Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
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Sjuls S, Jensen U, Littmann K, Bruchfeld A, Brinck J. Effective cholesterol lowering after myocardial infarction in patients with nephrotic syndrome may require a multi-pharmacological approach: a case report. EUROPEAN HEART JOURNAL-CASE REPORTS 2021; 5:ytab151. [PMID: 34124564 PMCID: PMC8189300 DOI: 10.1093/ehjcr/ytab151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/10/2020] [Accepted: 04/09/2021] [Indexed: 01/10/2023]
Abstract
Background Nephrotic syndrome causes severe hypercholesterolaemia due to increased production and altered clearance of lipoproteins from the liver. It is challenging for patients with nephrotic syndrome and coronary heart disease to meet LDL-cholesterol (LDL-C) goals for secondary prevention with conventional lipid-lowering therapy. Case summary We present a man with nephrotic syndrome caused by focal segmental glomerular sclerosis (FSGS) and hypercholesterolaemia. He presented at the emergency room (ER) with an ST-elevation myocardial infarction at the age of 26. On follow-up, the patient had persistent hypercholesterolaemia [LDL-C 3.9 mmol/L and lipoprotein(a) 308 nmol/L] despite a combination of lipid-lowering therapy with atorvastatin 80 mg/day and ezetimibe 10 mg/day. Addition of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitory antibody evolocumab 140 mg bi-monthly did not improve cholesterol levels. However, after addition of the sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin 10 mg/day on top of other anti-proteinuric treatments, the patient’s proteinuria was reduced and a dramatic drop in LDL-C level by 3.2–0.6 mmol/L (−81%) was observed when evolocumab was re-introduced. Discussion We show that target LDL-C levels were obtained in this patient with therapy-resistant FSGS and hypercholesterolaemia following multi-pharmacological treatment with SGLT2 and PCSK9 inhibitors on top of conventional lipid-lowering therapy. The SGLT2-inhibitor reduced proteinuria and, speculatively, also reduced urinary loss of PCSK9-antibody. Therefore, in patients with nephrotic syndrome and cardiovascular disease novel therapeutic options to manage proteinuria could be considered to improve the efficacy of the lipid-lowering therapy, especially when the protein-based PCSK9 inhibitors are used.
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Affiliation(s)
- Simon Sjuls
- Department of Endocrinology, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden
| | - Ulf Jensen
- Department of Cardiology, Södersjukhuset, Stockholm 118 83, Sweden
| | - Karin Littmann
- Department of Endocrinology, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden.,Department of Medicine H7, Karolinska Institutet, Stockholm 141 86, Sweden
| | - Annette Bruchfeld
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping 581 83, Sweden.,Department of Renal Medicine, Karolinska University Hospital and CLINTEC Karolinska Institute, Stockholm 141 86, Sweden
| | - Jonas Brinck
- Department of Endocrinology, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden.,Department of Medicine H7, Karolinska Institutet, Stockholm 141 86, Sweden
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7
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Littmann K, Wodaje T, Alvarsson M, Bottai M, Eriksson M, Parini P, Brinck J. The Association of Lipoprotein(a) Plasma Levels With Prevalence of Cardiovascular Disease and Metabolic Control Status in Patients With Type 1 Diabetes. Diabetes Care 2020; 43:1851-1858. [PMID: 31862789 DOI: 10.2337/dc19-1398] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2019] [Accepted: 11/19/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To investigate the association of the cardiovascular risk factor lipoprotein (Lp)(a) and vascular complications in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Patients with type 1 diabetes receiving regular care were recruited in this observational cross-sectional study and divided into four groups according to their Lp(a) levels in nmol/L (very low <10, low 10-30, intermediate 30-120, high >120). Prevalence of vascular complications was compared between the groups. In addition, the association between metabolic control, measured as HbA1c, and Lp(a) was studied. RESULTS The patients (n = 1,860) had a median age of 48 years, diabetes duration of 25 years, and HbA1c of 7.8% (61 mmol/mol). The median Lp(a) was 19 (interquartile range 10-71) nmol/L. No significant differences between men and women were observed, but Lp(a) levels increased with increasing age. Patients in the high Lp(a) group had higher prevalence of complications than patients in the very low Lp(a) group. The age- and smoking-status-adjusted relative risk ratio of having any macrovascular disease was 1.51 (95% CI 1.01-2.28, P = 0.048); coronary heart disease, 1.70 (95% CI 0.97-3.00, P = 0.063); albuminuria, 1.68 (95% CI 1.12-2.50, P = 0.01); and calcified aortic valve disease, 2.03 (95% CI 1.03-4.03; P = 0.042). Patients with good metabolic control, HbA1c <6.9% (<52 mmol/mol), had significantly lower Lp(a) levels than patients with poorer metabolic control, HbA1c >6.9% (>52 mmol/mol). CONCLUSIONS Lp(a) is a significant risk factor for macrovascular disease, albuminuria, and calcified aortic valve disease in patients with type 1 diabetes. Poor metabolic control in patients with type 1 diabetes is associated with increased Lp(a) levels.
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Affiliation(s)
- Karin Littmann
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.,Function Karolinska University Laboratory, Karolinska University Hospital, Stockholm, Sweden
| | - Tigist Wodaje
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden.,Theme Heart and Vascular, Karolinska University Hospital, Stockholm, Sweden
| | - Michael Alvarsson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Theme Endocrinology and Nephrology, Karolinska University Hospital, Stockholm, Sweden
| | - Matteo Bottai
- Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mats Eriksson
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden.,Theme Endocrinology and Nephrology, Karolinska University Hospital, Stockholm, Sweden
| | - Paolo Parini
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden.,Theme Endocrinology and Nephrology, Karolinska University Hospital, Stockholm, Sweden
| | - Jonas Brinck
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm, Sweden .,Theme Endocrinology and Nephrology, Karolinska University Hospital, Stockholm, Sweden
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Affiliation(s)
- Dick C Chan
- Metabolic Research Centre, School of Medicine, Faculty of Medicine and Health Sciences, University of Western Australia, Perth, Western Australia, Australia
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What do we know about the role of lipoprotein(a) in atherogenesis 57 years after its discovery? Prog Cardiovasc Dis 2020; 63:219-227. [PMID: 32277995 DOI: 10.1016/j.pcad.2020.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 04/04/2020] [Indexed: 12/12/2022]
Abstract
Elevated circulating concentrations of lipoprotein(a) [Lp(a)] is strongly associated with increased risk of atherosclerotic cardiovascular disease (CVD) and degenerative aortic stenosis. This relationship was first observed in prospective observational studies, and the causal relationship was confirmed in genetic studies. Everybody should have their Lp(a) concentration measured once in their lifetime. CVD risk is elevated when Lp(a) concentrations are high i.e. > 50 mg/dL (≥100 mmol/L). Extremely high Lp(a) levels >180 mg/dL (≥430 mmol/L) are associated with CVD risk similar to that conferred by familial hypercholesterolemia. Elevated Lp(a) level was previously treated with niacin, which exerts a potent Lp(a)-lowering effect. However, niacin is currently not recommended because, despite the improvement in lipid profile, no improvements on clinical outcomes have been observed. Furthermore, niacin use has been associated with severe adverse effects. Post hoc analyses of clinical trials with proprotein convertase subtilisin/kexin type-9 (PCSK9) inhibitors have shown that these drugs exert clinical benefits by lowering Lp(a), independent of their potent reduction of low-density lipoprotein cholesterol (LDL-C). It is not yet known whether PCSK9 inhibitors will be of clinical use in patients with elevated Lp(a). Apheresis is a very effective approach to Lp(a) reduction, which reduces CVD risk but is invasive and time-consuming and is thus reserved for patients with very high Lp(a) levels and progressive CVD. Studies are ongoing on the practical application of genetic approaches to therapy, including antisense oligonucleotides against apolipoprotein(a) and small interfering RNA (siRNA) technology, to reduce the synthesis of Lp(a).
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10
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Jawi MM, Frohlich J, Chan SY. Lipoprotein(a) the Insurgent: A New Insight into the Structure, Function, Metabolism, Pathogenicity, and Medications Affecting Lipoprotein(a) Molecule. J Lipids 2020; 2020:3491764. [PMID: 32099678 PMCID: PMC7016456 DOI: 10.1155/2020/3491764] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/17/2019] [Indexed: 12/15/2022] Open
Abstract
Lipoprotein(a) [Lp(a)], aka "Lp little a", was discovered in the 1960s in the lab of the Norwegian physician Kåre Berg. Since then, we have greatly improved our knowledge of lipids and cardiovascular disease (CVD). Lp(a) is an enigmatic class of lipoprotein that is exclusively formed in the liver and comprises two main components, a single copy of apolipoprotein (apo) B-100 (apo-B100) tethered to a single copy of a protein denoted as apolipoprotein(a) apo(a). Plasma levels of Lp(a) increase soon after birth to a steady concentration within a few months of life. In adults, Lp(a) levels range widely from <2 to 2500 mg/L. Evidence that elevated Lp(a) levels >300 mg/L contribute to CVD is significant. The improvement of isoform-independent assays, together with the insight from epidemiologic studies, meta-analyses, genome-wide association studies, and Mendelian randomization studies, has established Lp(a) as the single most common independent genetically inherited causal risk factor for CVD. This breakthrough elevated Lp(a) from a biomarker of atherosclerotic risk to a target of therapy. With the emergence of promising second-generation antisense therapy, we hope that we can answer the question of whether Lp(a) is ready for prime-time clinic use. In this review, we present an update on the metabolism, pathophysiology, and current/future medical interventions for high levels of Lp(a).
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Affiliation(s)
- Motasim M. Jawi
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Division of Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver V5Z 1M9, Canada
- Department of Clinical PhysiologyCorrection: Department of Physiology, University of Jeddah, P.O. Box: 24, Jeddah 21959, Saudi Arabia
| | - Jiri Frohlich
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - Sammy Y. Chan
- Healthy Heart Program, St. Paul's Hospital, Vancouver V6Z 1Y6, Canada
- Department of Medicine, Division of Cardiology, University of British Columbia, Vancouver V5Z 1M9, Canada
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11
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Boffa MB, Koschinsky ML. Proprotein convertase subtilisin/kexin type 9 inhibitors and lipoprotein(a)-mediated risk of atherosclerotic cardiovascular disease: more than meets the eye? Curr Opin Lipidol 2019; 30:428-437. [PMID: 31577611 DOI: 10.1097/mol.0000000000000641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
PURPOSE OF REVIEW Evidence continues to mount for elevated lipoprotein(a) [Lp(a)] as a prevalent, independent, and causal risk factor for atherosclerotic cardiovascular disease. However, the effects of existing lipid-lowering therapies on Lp(a) are comparatively modest and are not specific to Lp(a). Consequently, evidence that Lp(a)-lowering confers a cardiovascular benefit is lacking. Large-scale cardiovascular outcome trials (CVOTs) of inhibitory mAbs targeting proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) may address this issue. RECENT FINDINGS Although the ability of PCSK9i to lower Lp(a) by 15-30% is now clear, the mechanisms involved continue to be debated, with in-vitro and in-vivo studies showing effects on Lp(a) clearance (through the LDL receptor or other receptors) and Lp(a)/apolipoprotein(a) biosynthesis in hepatocytes. The FOURIER CVOT showed that patients with higher baseline levels of Lp(a) derived greater benefit from evolocumab and those with the lowest combined achieved Lp(a) and LDL-cholesterol (LDL-C) had the lowest event rate. Meta-analysis of ten phase 3 trials of alirocumab came to qualitatively similar conclusions concerning achieved Lp(a) levels, although an effect independent of LDL-C lowering could not be demonstrated. SUMMARY Although it is not possible to conclude that PCSK9i specifically lower Lp(a)-attributable risk, patients with elevated Lp(a) could derive incremental benefit from PCSK9i therapy.
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Affiliation(s)
| | - Marlys L Koschinsky
- Department of Physiology & Pharmacology
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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12
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Ma L, Chan DC, Ooi EMM, Marcovina SM, Barrett PHR, Watts GF. Apolipoprotein(a) Kinetics in Statin-Treated Patients With Elevated Plasma Lipoprotein(a) Concentration. J Clin Endocrinol Metab 2019; 104:6247-6255. [PMID: 31393573 DOI: 10.1210/jc.2019-01382] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/02/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND Lipoprotein(a) [Lp(a)] is a low-density lipoprotein‒like particle containing apolipoprotein(a) [apo(a)]. Patients with elevated Lp(a), even when treated with statins, are at increased risk of cardiovascular disease. We investigated the kinetic basis for elevated Lp(a) in these patients. OBJECTIVES Apo(a) production rate (PR) and fractional catabolic rate (FCR) were compared between statin-treated patients with and without elevated Lp(a). METHODS The kinetics of apo(a) were investigated in 14 patients with elevated Lp(a) and 15 patients with normal Lp(a) levels matched for age, sex, and body mass index using stable isotope techniques and compartmental modeling. All 29 patients were on background statin treatment. Plasma apo(a) concentration was measured using liquid chromatography-mass spectrometry. RESULTS The plasma concentration and PR of apo(a) were significantly higher in patients with elevated Lp(a) than in patients with normal Lp(a) concentration (all P < 0.01). The FCR of apo(a) was not significantly different between the groups. In univariate analysis, plasma concentration of apo(a) was significantly associated with apo(a) PR in both patient groups (r = 0.699 and r = 0.949, respectively; all P < 0.01). There was no significant association between plasma apo(a) concentration and FCR in either of the groups (r = 0.160 and r = -0.137, respectively). CONCLUSION Elevated plasma Lp(a) concentration is a consequence of increased hepatic production of Lp(a) particles in these patients. Our findings provide a kinetic rationale for the use of therapies that target the synthesis of apo(a) and production of Lp(a) particles in patients with elevated Lp(a).
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Affiliation(s)
- Louis Ma
- School of Biomedical Sciences, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
- School of Medicine, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
| | - Dick C Chan
- School of Biomedical Sciences, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
- School of Medicine, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
| | - Esther M M Ooi
- School of Biomedical Sciences, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
| | - Santica M Marcovina
- Northwest Lipid Metabolism and Diabetes Research Laboratories, Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | - P Hugh R Barrett
- Faculty of Medicine and Health, University of New England, Armidale, New South Wales, Australia
| | - Gerald F Watts
- School of Medicine, Faculty of Health and Medicine, University of Western Australia, Perth, Western Australia, Australia
- Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, Western Australia, Australia
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13
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Ma L, Chan DC, Ooi EMM, Barrett PHR, Watts GF. Fractional turnover of apolipoprotein(a) and apolipoprotein B-100 within plasma lipoprotein(a) particles in statin-treated patients with elevated and normal Lp(a) concentration. Metabolism 2019; 96:8-11. [PMID: 30995439 DOI: 10.1016/j.metabol.2019.04.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 12/31/2022]
Abstract
CONTEXT Lipoprotein(a) [Lp(a)] is a highly atherogenic lipoprotein characterized by apolipoprotein(a) [apo(a)] covalently bounded to apoB-100 (apoB). However, the metabolism of apo(a) and apoB within plasma Lp(a) particles in patients on statins remains unclear. METHODS The kinetics of Lp(a)-apo(a) and Lp(a)-apoB were determined in 20 patients with elevated Lp(a) (≥0.8 g/L; n = 10) and normal Lp(a) (≤0.3 g/L; n = 10) using stable isotope techniques and compartmental modeling. Plasma apo(a) concentration was measured using liquid chromatography-mass spectrometry. All patients were on statin therapy and were studied in the fasting state. RESULTS The fractional catabolic rate (FCR) of Lp(a)-apo(a) was not significantly different from that of Lp(a)-apoB in statin-treated patients with elevated or normal Lp(a) (P > 0.05 in both). Lp(a)-apo(a) FCR was significantly correlated with Lp(a)-apoB in patients with elevated and normal Lp(a) concentrations (r = 0.970 and r = 0.979, respectively; all P < 0.001) with Lin's concordance test showing substantial agreement between the FCRs of Lp(a)-apo(a) and Lp(a)-apoB in patients with elevated and normal Lp(a) concentrations (rc = 0.978 and rc = 0.966, respectively). CONCLUSION Our data indicate that the apo(a) and apoB proteins within Lp(a) particles have similar FCR and are therefore tightly coupled as an Lp(a) holoparticle in statin-treated patients with elevated and normal Lp(a) concentrations.
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Affiliation(s)
- Louis Ma
- School of Biomedical Sciences, University of Western Australia, Perth, Australia; School of Medicine, University of Western Australia, Perth, Australia
| | - Dick C Chan
- School of Biomedical Sciences, University of Western Australia, Perth, Australia; School of Medicine, University of Western Australia, Perth, Australia
| | - Esther M M Ooi
- School of Biomedical Sciences, University of Western Australia, Perth, Australia
| | - P Hugh R Barrett
- Faculty of Medicine and Health, University of New England, Armidale, Australia
| | - Gerald F Watts
- School of Medicine, University of Western Australia, Perth, Australia; Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Australia.
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14
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Gentile M, Iannuzzo G, Mattiello A, Marotta G, Rubba F, Iannuzzi A, Panico S, Rubba P. Association between Lp(a) and small dense LDL in menopausal women without metabolic syndrome. Acta Cardiol 2019; 74:232-236. [PMID: 29914303 DOI: 10.1080/00015385.2018.1481599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Background: Lipoprotein (a) (Lp [a]) is associated with premature atherosclerosis in menopausal women without metabolic syndrome (MS). MS is the main confounder in the relationship between Lp(a) and atherosclerosis in menopausal women. We have evaluated the relationship between Lp(a) and small dense-low density lipoprotein (sd-LDL) in 228 menopausal women participating to Progetto Atena. Methods: Lp(a) was measured and LDL particle separation was performed: mean LDL diameter and LDL score (% of sd-LDL) particles calculated. Results: Women without MS and elevated Lp(a) have increased number of sd-LDL (p < .05) and higher LDL score compared with those below the median of the studied population (p < .05). The association between Lp(a) and sd-LDL was evaluated taking into account different adjustment models. Women with elevated levels of Lp(a) show the following OR of having a small LDL diameter (in the lowest quartile): 1.02, p = .003; adjusted for age; 1.02, p = .002; adjusted for age, and triglycerides, or a high LDL score (in the highest quartile): 1.02, p = .006; adjusted for age; 1.02, p = .002; adjusted for age and triglycerides. Conclusions: In this group of menopausal women without MS, the independent association of Lp(a) with sd-LDL might explain at least in part the association of Lp(a) with premature atherosclerosis.
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Affiliation(s)
- Marco Gentile
- Dipartimento di Medicina Clinica e Chirurgia, Università “Federico II” di Napoli, Napoli, Italy
| | - Gabriella Iannuzzo
- Dipartimento di Medicina Clinica e Chirurgia, Università “Federico II” di Napoli, Napoli, Italy
| | - Amalia Mattiello
- Dipartimento di Medicina Clinica e Chirurgia, Università “Federico II” di Napoli, Napoli, Italy
| | - Gennaro Marotta
- Dipartimento di Medicina Clinica e Chirurgia, Università “Federico II” di Napoli, Napoli, Italy
| | - Fabiana Rubba
- Dipartimento di Sanità Pubblica, Università degli Studi di Napoli Federico II, Napoli, Italy
| | - Arcangelo Iannuzzi
- Dipartimento di Sanità Pubblica, Università degli Studi di Napoli Federico II, Napoli, Italy
| | - Salvatore Panico
- Dipartimento di Medicina Clinica e Chirurgia, Università “Federico II” di Napoli, Napoli, Italy
| | - Paolo Rubba
- UO Medicina Interna, AORN “A. Cardarelli” di Napoli, Napoli, Italy
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15
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Nakajima K, Tokita Y, Tanaka A, Takahashi S. The VLDL receptor plays a key role in the metabolism of postprandial remnant lipoproteins. Clin Chim Acta 2019; 495:382-393. [PMID: 31078566 DOI: 10.1016/j.cca.2019.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/03/2019] [Accepted: 05/06/2019] [Indexed: 12/21/2022]
Abstract
A new concept to account for the process of postprandial remnant lipoprotein metabolism is proposed based on the characteristics of lipoprotein particles and their receptors. The characteristics of remnant lipoprotein (RLP) were investigated using an immuno-separation method. The majority of the postprandial lipoproteins increased after fat intake was shown to be VLDL remnants, not chylomicron (CM) remnants, based on the significantly high ratio of apoB100/apoB48 in the RLP and the high degree of similarity in the particle size of the apoB48 and apoB100 carrying lipoproteins, which fluctuate in parallel during a 6 h period after fat intake. The VLDL receptor was discovered as a receptor for TG-rich lipoprotein metabolism and is located in peripheral tissues such as skeletal muscle, adipose tissue, etc., but not in the liver. Postprandial VLDL particles are strongly bound and internalized into cells expressing the VLDL receptor. Ligands that bind to VLDL receptor, such as LPL and Lp(a), present in RLP. The presence of various specific ligands in VLDL remnants may enhance the capacity for binding to the VLDL receptor, which play the role primarily for energy delivery to the peripheral tissues, but is also a causal factor in atherogenic diseases when excessively and/or continuously remained in plasma.
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Affiliation(s)
- Katsuyuki Nakajima
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan; Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan.
| | - Yoshiharu Tokita
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan; Graduate School of Health Sciences, Gunma University, Maebashi, Gunma, Japan
| | - Akira Tanaka
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan
| | - Sadao Takahashi
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan; Division of Diabetes, Ageo Central General Hospital, Saitama, Japan
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16
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Chan DC, Watts GF, Coll B, Wasserman SM, Marcovina SM, Barrett PHR. Lipoprotein(a) Particle Production as a Determinant of Plasma Lipoprotein(a) Concentration Across Varying Apolipoprotein(a) Isoform Sizes and Background Cholesterol-Lowering Therapy. J Am Heart Assoc 2019; 8:e011781. [PMID: 30897995 PMCID: PMC6509712 DOI: 10.1161/jaha.118.011781] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 02/12/2019] [Indexed: 12/24/2022]
Abstract
Background Elevated lipoprotein(a) (Lp(a)), a low-density lipoprotein-like particle bound to the polymorphic apolipoprotein(a) (apo(a)), may be causal for cardiovascular disease. However, the metabolism of Lp(a) in humans is poorly understood. Methods and Results We investigated the kinetics of Lp(a)-apo(a) and low-density lipoprotein-apoB-100 in 63 normolipidemic men. The fractional catabolic rate ( FCR ) and production rate PR ) were studied. Plasma apo(a) concentration was significantly and inversely associated with apo(a) isoform size ( r=-0.536, P<0.001) and apo(a) FCR ( r=-0.363, P<0.01), and positively with apo(a) PR ( r=0.877, P<0.001). There were no significant associations between the FCR s of apo(a) and low-density lipoprotein-apoB-100. Subjects with smaller apo(a) isoform sizes (≤22 kringle IV repeats) had significantly higher apo(a) PR ( P<0.05) and lower apo(a) FCR ( P<0.01) than those with larger sizes. Plasma apo(a) concentration was significantly associated with apo(a) PR ( r=0.930, P<0.001), but not with FCR ( r=-0.012, P>0.05) in subjects with smaller apo(a) isoform size. In contrast, both apo(a) PR and FCR were significantly associated with plasma apo(a) concentrations ( r=0.744 and -0.389, respectively, P<0.05) in subjects with larger isoforms. In multiple regression analysis, apo(a) PR and apo(a) isoform size were significant predictors of plasma apo(a) concentration independent of low-density lipoprotein-apoB-100 FCR and background therapy with atorvastatin and evolocumab. Conclusions In normolipidemic men, the plasma Lp(a) concentration is predominantly determined by the rate of production of Lp(a) particles, irrespective of apo(a) isoform size and background therapy with a statin and a proprotein convertase subtilisin-kexin type 9 inhibitor. Our findings underscore the importance of therapeutic targeting of the hepatic synthesis and secretion of Lp(a) particles. Lp(a) particle catabolism may only play a modest role in determining Lp(a) concentration in subjects with larger apo(a) isoform size. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 02189837.
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Affiliation(s)
- Dick C. Chan
- School of MedicineUniversity of Western AustraliaPerthAustralia
- School of Biomedical ScienceUniversity of Western AustraliaPerthAustralia
| | - Gerald F. Watts
- School of MedicineUniversity of Western AustraliaPerthAustralia
- The Lipid Disorders ClinicDepartment of CardiologyRoyal Perth HospitalPerthAustralia
| | | | | | - Santica M. Marcovina
- Northwest Lipid Metabolism and Diabetes Research LaboratoriesDivision of Metabolism, Endocrinology, and NutritionDepartment of MedicineUniversity of WashingtonSeattleWA
| | - P. Hugh R. Barrett
- School of Biomedical ScienceUniversity of Western AustraliaPerthAustralia
- Faculty of Medicine and HealthUniversity of New EnglandArmidaleNew South WalesAustralia
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17
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Borrelli MJ, Youssef A, Boffa MB, Koschinsky ML. New Frontiers in Lp(a)-Targeted Therapies. Trends Pharmacol Sci 2019; 40:212-225. [PMID: 30732864 DOI: 10.1016/j.tips.2019.01.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 12/13/2022]
Abstract
Interest in lipoprotein (a) [Lp(a)] has exploded over the past decade with the emergence of genetic and epidemiological studies pinpointing elevated levels of this unique lipoprotein as a causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). This review summarizes the most recent discoveries regarding therapeutic approaches to lower Lp(a) and presents these findings in the context of an emerging, although far from complete, understanding of the biosynthesis and catabolism of Lp(a). Application of Lp(a)-specific lowering agents to outcome trials will be the key to opening this new frontier in the battle against CVD.
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Affiliation(s)
- Matthew J Borrelli
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Amer Youssef
- Robarts Research Institute, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Michael B Boffa
- Robarts Research Institute, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada; Department of Biochemistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Marlys L Koschinsky
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada; Robarts Research Institute, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, Ontario, Canada.
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18
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Boffa MB, Koschinsky ML. Oxidized phospholipids as a unifying theory for lipoprotein(a) and cardiovascular disease. Nat Rev Cardiol 2019; 16:305-318. [DOI: 10.1038/s41569-018-0153-2] [Citation(s) in RCA: 114] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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19
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McCormick SPA, Schneider WJ. Lipoprotein(a) catabolism: a case of multiple receptors. Pathology 2018; 51:155-164. [PMID: 30595508 DOI: 10.1016/j.pathol.2018.11.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 01/09/2023]
Abstract
Lipoprotein(a) [Lp(a)] is an apolipoprotein B (apoB)-containing plasma lipoprotein similar in structure to low-density lipoprotein (LDL). Lp(a) is more complex than LDL due to the presence of apolipoprotein(a) [apo(a)], a large glycoprotein sharing extensive homology with plasminogen, which confers some unique properties onto Lp(a) particles. ApoB and apo(a) are essential for the assembly and catabolism of Lp(a); however, other proteins associated with the particle may modify its metabolism. Lp(a) specifically carries a cargo of oxidised phospholipids (OxPL) bound to apo(a) which stimulates many proinflammatory pathways in cells of the arterial wall, a key property underlying its pathogenicity and association with cardiovascular disease (CVD). While the liver and kidney are the major tissues implicated in Lp(a) clearance, the pathways for Lp(a) uptake appear to be complex and are still under investigation. Biochemical studies have revealed an exceptional array of receptors that associate with Lp(a) either via its apoB, apo(a), or OxPL components. These receptors fall into five main categories, namely 'classical' lipoprotein receptors, toll-like and scavenger receptors, lectins, and plasminogen receptors. The roles of these receptors have largely been dissected by genetic manipulation in cells or mice, although their relative physiological importance for removal of Lp(a) from the circulation remains unclear. The LPA gene encoding apo(a) has an overwhelming effect on Lp(a) levels which precludes any clear associations between potential Lp(a) receptor genes and Lp(a) levels in population studies. Targeted approaches and the selection of unique Lp(a) phenotypes within populations has nevertheless allowed for some associations to be made. Few of the proposed Lp(a) receptors can specifically be manipulated with current drugs and, as such, it is not currently clear whether any of these receptors could provide relevant targets for therapeutic manipulation of Lp(a) levels. This review summarises the current status of knowledge about receptor-mediated pathways for Lp(a) catabolism.
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Affiliation(s)
- Sally P A McCormick
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
| | - Wolfgang J Schneider
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, Vienna, Austria
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20
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Kostner KM, Kostner GM, Wierzbicki AS. Is Lp(a) ready for prime time use in the clinic? A pros-and-cons debate. Atherosclerosis 2018; 274:16-22. [PMID: 29747086 DOI: 10.1016/j.atherosclerosis.2018.04.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 12/11/2022]
Abstract
Lipoprotein (a) (Lp(a)) is a cholesterol-rich lipoprotein known since 1963. In spite of extensive research on Lp(a), there are still numerous gaps in our knowledge relating to its function, biosynthesis and catabolism. One reason for this might be that apo(a), the characteristic glycoprotein of Lp(a), is expressed only in primates. Results from experiments using transgenic animals therefore may need verification in humans. Studies on Lp(a) are also handicapped by the great number of isoforms of apo(a) and the heterogeneity of apo(a)-containing fractions in plasma. Quantification of Lp(a) in the clinical laboratory for a long time has not been standardized. Starting from its discovery, reports accumulated that Lp(a) contributed to the risk of cardiovascular disease (CVD), myocardial infarction (MI) and stroke. Early reports were based on case control studies but in the last decades a great deal of prospective studies have been published that highlight the increased risk for CVD and MI in patients with elevated Lp(a). Final answers to the question of whether Lp(a) is ready for wider clinical use will come from intervention studies with novel selective Lp(a) lowering medications that are currently underway. This article expounds arguments for and against this proposition from currently available data.
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Affiliation(s)
- Karam M Kostner
- Department of Cardiology, Mater Hospital and University of Queensland, Brisbane, Australia
| | - Gert M Kostner
- Department of Molecular Biology and Biochemistry, Gottfried Schatz Research Center for Cell Signaling, Medical University of Graz, Austria
| | - Anthony S Wierzbicki
- Department of Metabolic Medicine/Chemical Pathology, Guy's & St Thomas' Hospitals, London, UK.
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21
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Zanoni P, Velagapudi S, Yalcinkaya M, Rohrer L, von Eckardstein A. Endocytosis of lipoproteins. Atherosclerosis 2018; 275:273-295. [PMID: 29980055 DOI: 10.1016/j.atherosclerosis.2018.06.881] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/04/2018] [Accepted: 06/22/2018] [Indexed: 02/06/2023]
Abstract
During their metabolism, all lipoproteins undergo endocytosis, either to be degraded intracellularly, for example in hepatocytes or macrophages, or to be re-secreted, for example in the course of transcytosis by endothelial cells. Moreover, there are several examples of internalized lipoproteins sequestered intracellularly, possibly to exert intracellular functions, for example the cytolysis of trypanosoma. Endocytosis and the subsequent intracellular itinerary of lipoproteins hence are key areas for understanding the regulation of plasma lipid levels as well as the biological functions of lipoproteins. Indeed, the identification of the low-density lipoprotein (LDL)-receptor and the unraveling of its transcriptional regulation led to the elucidation of familial hypercholesterolemia as well as to the development of statins, the most successful therapeutics for lowering of cholesterol levels and risk of atherosclerotic cardiovascular diseases. Novel limiting factors of intracellular trafficking of LDL and the LDL receptor continue to be discovered and to provide drug targets such as PCSK9. Surprisingly, the receptors mediating endocytosis of high-density lipoproteins or lipoprotein(a) are still a matter of controversy or even new discovery. Finally, the receptors and mechanisms, which mediate the uptake of lipoproteins into non-degrading intracellular itineraries for re-secretion (transcytosis, retroendocytosis), storage, or execution of intracellular functions, are largely unknown.
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Affiliation(s)
- Paolo Zanoni
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Srividya Velagapudi
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Mustafa Yalcinkaya
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Lucia Rohrer
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Arnold von Eckardstein
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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22
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Boffa MB, Koschinsky ML. The journey towards understanding lipoprotein(a) and cardiovascular disease risk: are we there yet? Curr Opin Lipidol 2018. [PMID: 29528858 DOI: 10.1097/mol.0000000000000499] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE OF REVIEW Evidence continues to mount for an important role for elevated plasma concentrations of lipoprotein(a) [Lp(a)] in mediating risk of atherothrombotic and calcific aortic valve diseases. However, there continues to be great uncertainty regarding some basic aspects of Lp(a) biology including its biosynthesis and catabolism, its mechanisms of action in health and disease, and the significance of its isoform size heterogeneity. Moreover, the precise utility of Lp(a) in the clinic remains undefined. RECENT FINDINGS The contribution of elevated Lp(a) to cardiovascular risk continues to be more precisely defined by larger studies. In particular, the emerging role of Lp(a) as a potent risk factor for calcific aortic valve disease has received much scrutiny. Mechanistic studies have identified commonalities underlying the impact of Lp(a) on atherosclerosis and aortic valve disease, most notably related to Lp(a)-associated oxidized phospholipids. The mechanisms governing Lp(a) concentrations remain a source of considerable dispute. SUMMARY This article highlights some key remaining challenges in understanding Lp(a) actions and clinical significance. Most important in this regard is demonstration of a beneficial effect of lowering Lp(a), a development that is on the horizon as effective Lp(a)-lowering therapies are being tested in the clinic.
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Affiliation(s)
| | - Marlys L Koschinsky
- Robarts Research Institute, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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23
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Watts GF, Chan DC, Somaratne R, Wasserman SM, Scott R, Marcovina SM, Barrett PHR. Controlled study of the effect of proprotein convertase subtilisin-kexin type 9 inhibition with evolocumab on lipoprotein(a) particle kinetics. Eur Heart J 2018; 39:2577-2585. [DOI: 10.1093/eurheartj/ehy122] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 03/02/2018] [Indexed: 12/24/2022] Open
Affiliation(s)
- Gerald F Watts
- Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, WA, Australia
- Schools of Medicine and Biomedical Science, University of Western Australia, Perth, WA, Australia
| | - Dick C Chan
- Schools of Medicine and Biomedical Science, University of Western Australia, Perth, WA, Australia
| | | | | | - Rob Scott
- Formerly of Amgen, Inc., Thousand Oaks, CA, USA
| | - Santica M Marcovina
- Northwest Lipid Metabolism and Diabetes Research Laboratories, Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington, Seattle, WA, USA
| | - P Hugh R Barrett
- Schools of Medicine and Biomedical Science, University of Western Australia, Perth, WA, Australia
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24
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Sun D, Li S, Zhao X, Wu NQ, Zhu CG, Guo YL, Gao Y, Qing P, Cui CJ, Liu G, Sun J, Dong Q, Li JJ. Association between lipoprotein (a) and proprotein convertase substilisin/kexin type 9 in patients with heterozygous familial hypercholesterolemia: A case-control study. Metabolism 2018; 79:33-41. [PMID: 29129821 DOI: 10.1016/j.metabol.2017.11.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 10/27/2017] [Accepted: 11/06/2017] [Indexed: 12/29/2022]
Abstract
BACKGROUND Recent data have suggested an important role of lipoprotein (a) [Lp(a)] and proprotein convertase substilisin/kexin type 9 (PCSK9) in the development of atherosclerotic cardiovascular disease (ASCVD) in both general population and family hypercholesterolemia (FH), while the relation of Lp(a) to PCSK9 has not been examined. OBJECTIVE The aim of the present study was to investigate the association between plasma PCSK9 and Lp(a)in patients with heterozygous FH (HeFH). METHODS Two hundred and fifty-five molecularly confirmed patients with HeFH were compared to 255 age- and gender-matched non-FH controls. Plasma PCSK9 and Lp(a) concentrations were measured using ELISA and immunoturbidimetric method respectively, and finally their association was assessed. RESULTS Both plasma PCSK9 and Lp(a) levels were significantly higher in patients with HeFH compared to control group (p<0.001). Besides, the Lp(a) concentration and percentage of Lp(a)≥300mg/L were increased by PCSK9 tertiles in HeFH group (both p<0.05) while not in control group. In partial correlation analysis, Lp(a) was associated with PCSK9 (r=0.254, p<0.001) in HeFH group but not in control, which were further confirmed by multivariable linear regression analysis. Furthermore, significant associations between Lp(a) and PCSK9 were also found in subgroups of HeFH group irrespective of definite or probable FH, with and without coronary artery disease (CAD), and with statin or not. CONCLUSIONS Plasma Lp(a) level was associated with PCSK9 in patients with HeFH alone, suggesting that much about the interaction of PCSK9 with Lp(a) in FH need further explorations.
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Affiliation(s)
- Di Sun
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Sha Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Xi Zhao
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Na-Qiong Wu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Cheng-Gang Zhu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Yuan-Lin Guo
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Ying Gao
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Ping Qing
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Chuan-Jue Cui
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Geng Liu
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Jing Sun
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Qian Dong
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China
| | - Jian-Jun Li
- Division of Dyslipidemia, State Key Laboratory of Cardiovascular Disease, Fu Wai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100037, China.
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Nakajima K, Tanaka A. Atherogenic postprandial remnant lipoproteins; VLDL remnants as a causal factor in atherosclerosis. Clin Chim Acta 2018; 478:200-215. [PMID: 29307667 DOI: 10.1016/j.cca.2017.12.039] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 12/23/2017] [Accepted: 12/24/2017] [Indexed: 01/02/2023]
Abstract
Oxidized LDL (Ox-LDL) and chylomicron (CM) remnants have been suggested to be the most atherogenic lipoproteins that initiate and exacerbate coronary atherosclerosis. In this review, we propose a hypothesis of the causal lipoproteins in atherosclerosis based on our recent findings on postprandial remnant lipoproteins (RLP). Plasma RLP-C and RLP-TG increased significantly after food intake, especially a fat load. More than 80% of the TG increase after the fat load consisted of the TG in RLP, which contained significantly greater apoB100 than apoB48 particles as VLDL remnants. The majority of the LPL in non-heparin plasma was found in RLP as an RLP-LPL complex and released into the circulation after hydrolysis. Plasma LPL did not increase after food intake, which may have caused the partial hydrolysis of CM and VLDL as well as the significant increase of RLP-TG in the postprandial plasma. LPL was inversely correlated with the RLP particle size after food intake. We showed that VLDL remnants are the major atherogenic lipoproteins in the postprandial plasma associated with insufficient LPL activity and a causal factor in the initiation and progression of atherosclerosis. We also propose "LPL bound TG-rich lipoproteins" as a new definition of remnant lipoproteins based on the findings of the RLP-LPL complex in the non-heparin plasma.
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Affiliation(s)
- Katsuyuki Nakajima
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan; Department of Clinical Laboratory Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan.
| | - Akira Tanaka
- Laboratory of Clinical Nutrition and Medicine, Kagawa Nutrition University, Tokyo, Japan
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26
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Scipione CA, Koschinsky ML, Boffa MB. Lipoprotein(a) in clinical practice: New perspectives from basic and translational science. Crit Rev Clin Lab Sci 2017; 55:33-54. [PMID: 29262744 DOI: 10.1080/10408363.2017.1415866] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Elevated plasma concentrations of lipoprotein(a) (Lp(a)) are a causal risk factor for coronary heart disease (CHD) and calcific aortic valve stenosis (CAVS). Genetic, epidemiological and in vitro data provide strong evidence for a pathogenic role for Lp(a) in the progression of atherothrombotic disease. Despite these advancements and a race to develop new Lp(a) lowering therapies, there are still many unanswered and emerging questions about the metabolism and pathophysiology of Lp(a). New studies have drawn attention to Lp(a) as a contributor to novel pathogenic processes, yet the mechanisms underlying the contribution of Lp(a) to CVD remain enigmatic. New therapeutics show promise in lowering plasma Lp(a) levels, although the complete mechanisms of Lp(a) lowering are not fully understood. Specific agents targeted to apolipoprotein(a) (apo(a)), namely antisense oligonucleotide therapy, demonstrate potential to decrease Lp(a) to levels below the 30-50 mg/dL (75-150 nmol/L) CVD risk threshold. This therapeutic approach should aid in assessing the benefit of lowering Lp(a) in a clinical setting.
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Affiliation(s)
- Corey A Scipione
- a Department of Advanced Diagnostics , Toronto General Hospital Research Institute, UHN , Toronto , Canada
| | - Marlys L Koschinsky
- b Robarts Research Institute , Western University , London , Canada.,c Department of Physiology & Pharmacology , Schulich School of Medicine & Dentistry, Western University , London , Canada
| | - Michael B Boffa
- d Department of Biochemistry , Western University , London , Canada
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27
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Abstract
Metabolic Syndrome (MetS), affecting at least 30% of adults in the Western World, is characterized by three out of five variables, from high triglycerides, to elevated waist circumference and blood pressure. MetS is not characterized by elevated cholesterolemia, but is rather the consequence of a complex interaction of factors generally leading to increased insulin resistance. Drug treatments are of difficult handling, whereas well-characterized nutraceuticals may offer an effective alternative. Among these, functional foods, e.g. plant proteins, have been shown to improve insulin resistance and reduce triglyceride secretion. Pro- and pre-biotics, that are able to modify intestinal microbiome, reduce absorption of specific nutrients and improve the metabolic handling of energy-rich foods. Finally, specific nutraceuticals have proven to be of benefit, in particular, red-yeast rice, berberine, curcumin as well as vitamin D. All these can improve lipid handling by the liver as well as ameliorate insulin resistance. While lifestyle approaches, such as with the Mediterranean diet, may prove to be too complex for the single patient, better knowledge of selected nutraceuticals and more appropriate formulations leading to improved bioavailability will certainly widen the use of these agents, already in large use for the management of these very frequent patient groups. Key messages Functional foods, e.g. plant proteins, improve insulin resistance. Pro- and pre-biotics improve the metabolic handling of energy-rich foods. Nutraceutical can offer a significant help in handling MetS patients being part of lifestyle recommendations.
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Affiliation(s)
- Cesare R Sirtori
- a Centro Dislipidemie , A.S.S.T. Grande Ospedale Metropolitano Niguarda , Milan , Italy
| | - Chiara Pavanello
- b Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro E. Grossi Paoletti , Università degli Studi di Milano , Milan , Italy
| | - Laura Calabresi
- b Dipartimento di Scienze Farmacologiche e Biomolecolari, Centro E. Grossi Paoletti , Università degli Studi di Milano , Milan , Italy
| | - Massimiliano Ruscica
- c Dipartimento di Scienze Farmacologiche e Biomolecolari , Università degli Studi di Milano , Milan , Italy
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28
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Ellis KL, Boffa MB, Sahebkar A, Koschinsky ML, Watts GF. The renaissance of lipoprotein(a): Brave new world for preventive cardiology? Prog Lipid Res 2017; 68:57-82. [DOI: 10.1016/j.plipres.2017.09.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/01/2017] [Accepted: 09/05/2017] [Indexed: 12/24/2022]
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29
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Enkhmaa B, Anuurad E, Zhang W, Yue K, Li CS, Berglund L. The roles of apo(a) size, phenotype, and dominance pattern in PCSK9-inhibition-induced reduction in Lp(a) with alirocumab. J Lipid Res 2017; 58:2008-2016. [PMID: 28798072 DOI: 10.1194/jlr.m078212] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/09/2017] [Indexed: 11/20/2022] Open
Abstract
An elevated level of lipoprotein (a) [Lp(a)] is a risk factor for CVD. Alirocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9, is reported to reduce Lp(a) levels. The relationship of Lp(a) reduction with apo(a) size polymorphism, phenotype, and dominance pattern and LDL cholesterol (LDL-C) reduction was evaluated in a pooled analysis of 155 hypercholesterolemic patients (75 with heterozygous familial hypercholesterolemia) from two clinical trials. Alirocumab significantly reduced total Lp(a) (pooled median: -21%, P = 0.0001) and allele-specific apo(a), an Lp(a) level carried by the smaller (median: -18%, P = 0.002) or the larger (median: -37%, P = 0.0005) apo(a) isoform, at week 8 versus baseline. The percent reduction in Lp(a) level with alirocumab was similar across apo(a) phenotypes (single vs. double bands) and carriers and noncarriers of a small size apo(a) (≤22 kringles). The percent reduction in LDL-C correlated significantly with the percent reduction in Lp(a) level (r = 0.407, P < 0.0001) and allele-specific apo(a) level associated with the smaller (r = 0.390, P < 0.0001) or larger (r = 0.270, P = 0.0183) apo(a) sizes. In conclusion, alirocumab-induced Lp(a) reduction was independent of apo(a) phenotypes and the presence or absence of a small size apo(a).
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Affiliation(s)
- Byambaa Enkhmaa
- Departments of Internal Medicine University of California, Davis, CA
| | | | - Wei Zhang
- Departments of Internal Medicine University of California, Davis, CA
| | - Kun Yue
- Public Health Sciences, University of California, Davis, CA.,Department of Statistics and Actuarial Science, University of Hong Kong, Pokfulam, Hong Kong
| | - Ching-Shang Li
- Public Health Sciences, University of California, Davis, CA
| | - Lars Berglund
- Departments of Internal Medicine University of California, Davis, CA
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Reyes-Soffer G, Ginsberg HN, Ramakrishnan R. The metabolism of lipoprotein (a): an ever-evolving story. J Lipid Res 2017; 58:1756-1764. [PMID: 28720561 DOI: 10.1194/jlr.r077693] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/18/2017] [Indexed: 02/06/2023] Open
Abstract
Lipoprotein (a) [Lp(a)] is characterized by apolipoprotein (a) [apo(a)] covalently bound to apolipoprotein B 100. It was described in human plasma by Berg et al. in 1963 and the gene encoding apo(a) (LPA) was cloned in 1987 by Lawn and colleagues. Epidemiologic and genetic studies demonstrate that increases in Lp(a) plasma levels increase the risk of atherosclerotic cardiovascular disease. Novel Lp(a) lowering treatments highlight the need to understand the regulation of plasma levels of this atherogenic lipoprotein. Despite years of research, significant uncertainty remains about the assembly, secretion, and clearance of Lp(a). Specifically, there is ongoing controversy about where apo(a) and apoB-100 bind to form Lp(a); which apoB-100 lipoproteins bind to apo(a) to create Lp(a); whether binding of apo(a) is reversible, allowing apo(a) to bind to more than one apoB-100 lipoprotein during its lifespan in the circulation; and how Lp(a) or apo(a) leave the circulation. In this review, we highlight past and recent data from stable isotope studies of Lp(a) metabolism, highlighting the critical metabolic uncertainties that exist. We present kinetic models to describe results of published studies using stable isotopes and suggest what future studies are required to improve our understanding of Lp(a) metabolism.
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Affiliation(s)
- Gissette Reyes-Soffer
- Departments of Medicine Columbia University College of Physicians and Surgeons, New York, NY 10032
| | - Henry N Ginsberg
- Departments of Medicine Columbia University College of Physicians and Surgeons, New York, NY 10032
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31
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Sharma M, Redpath GM, Williams MJA, McCormick SPA. Recycling of Apolipoprotein(a) After PlgRKT-Mediated Endocytosis of Lipoprotein(a). Circ Res 2016; 120:1091-1102. [PMID: 28003220 DOI: 10.1161/circresaha.116.310272] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 12/15/2016] [Accepted: 12/21/2016] [Indexed: 11/16/2022]
Abstract
RATIONALE Lipoprotein(a) [Lp(a)] is a low-density lipoprotein-like lipoprotein and important cardiovascular risk factor whose cognate receptor and intracellular fate remains unknown. OBJECTIVE Our study aimed to determine the intracellular trafficking pathway for Lp(a) and the receptor responsible for its uptake in liver cells. METHODS AND RESULTS Human hepatoma cells were treated with Lp(a) purified from human plasma and Lp(a) uptake studied using Western blot analysis and intracellular localization of Lp(a) by confocal microscopy. Lp(a) was maximally internalized by 2 hours and was detected by an antiapo(a) antibody to be localized to Rab5-positive early endosomes, the trans-Golgi network, and subsequently Rab11-positive recycling endosomes. In human hepatoma cells, the apo(a) component from the internalized Lp(a) was resecreted back into the cellular media, whereas the low-density lipoprotein component was localized to the lysosomal compartment. Lp(a) internalization was reduced 0.35-fold in HAP1 and 0.33-fold in human hepatoma cells in which the plasminogen receptor (KT) was knocked out. Conversely, Lp(a) internalization was enhanced 2-fold in HAP1 and 1.6-fold in human hepatoma cells in which plasminogen receptor (KT) was overexpressed, showing for the first time the role of a specific plasminogen receptor in Lp(a) uptake. CONCLUSIONS The novel findings that Lp(a) is internalized by the plasminogen receptor, plasminogen receptor (KT), and the apo(a) component is recycled may have important implications for the catabolism and function of Lp(a).
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Affiliation(s)
- Monika Sharma
- From the Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand (M.S., G.M.R., S.P.A.M.); and Department of Medicine, Dunedin School of Medicine, University of Otago, New Zealand (M.J.A.W.)
| | - Gregory M Redpath
- From the Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand (M.S., G.M.R., S.P.A.M.); and Department of Medicine, Dunedin School of Medicine, University of Otago, New Zealand (M.J.A.W.)
| | - Michael J A Williams
- From the Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand (M.S., G.M.R., S.P.A.M.); and Department of Medicine, Dunedin School of Medicine, University of Otago, New Zealand (M.J.A.W.)
| | - Sally P A McCormick
- From the Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand (M.S., G.M.R., S.P.A.M.); and Department of Medicine, Dunedin School of Medicine, University of Otago, New Zealand (M.J.A.W.).
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32
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Reyes-Soffer G, Pavlyha M, Ngai C, Thomas T, Holleran S, Ramakrishnan R, Karmally W, Nandakumar R, Fontanez N, Obunike J, Marcovina SM, Lichtenstein AH, Matthan NR, Matta J, Maroccia M, Becue F, Poitiers F, Swanson B, Cowan L, Sasiela WJ, Surks HK, Ginsberg HN. Effects of PCSK9 Inhibition With Alirocumab on Lipoprotein Metabolism in Healthy Humans. Circulation 2016; 135:352-362. [PMID: 27986651 PMCID: PMC5262523 DOI: 10.1161/circulationaha.116.025253] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 12/07/2016] [Indexed: 12/02/2022]
Abstract
Supplemental Digital Content is available in the text. Background: Alirocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), lowers plasma low-density lipoprotein (LDL) cholesterol and apolipoprotein B100 (apoB). Although studies in mice and cells have identified increased hepatic LDL receptors as the basis for LDL lowering by PCSK9 inhibitors, there have been no human studies characterizing the effects of PCSK9 inhibitors on lipoprotein metabolism. In particular, it is not known whether inhibition of PCSK9 has any effects on very low-density lipoprotein or intermediate-density lipoprotein (IDL) metabolism. Inhibition of PCSK9 also results in reductions of plasma lipoprotein (a) levels. The regulation of plasma Lp(a) levels, including the role of LDL receptors in the clearance of Lp(a), is poorly defined, and no mechanistic studies of the Lp(a) lowering by alirocumab in humans have been published to date. Methods: Eighteen (10 F, 8 mol/L) participants completed a placebo-controlled, 2-period study. They received 2 doses of placebo, 2 weeks apart, followed by 5 doses of 150 mg of alirocumab, 2 weeks apart. At the end of each period, fractional clearance rates (FCRs) and production rates (PRs) of apoB and apo(a) were determined. In 10 participants, postprandial triglycerides and apoB48 levels were measured. Results: Alirocumab reduced ultracentrifugally isolated LDL-C by 55.1%, LDL-apoB by 56.3%, and plasma Lp(a) by 18.7%. The fall in LDL-apoB was caused by an 80.4% increase in LDL-apoB FCR and a 23.9% reduction in LDL-apoB PR. The latter was due to a 46.1% increase in IDL-apoB FCR coupled with a 27.2% decrease in conversion of IDL to LDL. The FCR of apo(a) tended to increase (24.6%) without any change in apo(a) PR. Alirocumab had no effects on FCRs or PRs of very low-density lipoproteins-apoB and very low-density lipoproteins triglycerides or on postprandial plasma triglycerides or apoB48 concentrations. Conclusions: Alirocumab decreased LDL-C and LDL-apoB by increasing IDL- and LDL-apoB FCRs and decreasing LDL-apoB PR. These results are consistent with increases in LDL receptors available to clear IDL and LDL from blood during PCSK9 inhibition. The increase in apo(a) FCR during alirocumab treatment suggests that increased LDL receptors may also play a role in the reduction of plasma Lp(a). Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01959971.
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Affiliation(s)
- Gissette Reyes-Soffer
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.).
| | - Marianna Pavlyha
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Colleen Ngai
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Tiffany Thomas
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Stephen Holleran
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Rajasekhar Ramakrishnan
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Wahida Karmally
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Renu Nandakumar
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Nelson Fontanez
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Joseph Obunike
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Santica M Marcovina
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Alice H Lichtenstein
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Nirupa R Matthan
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - James Matta
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Magali Maroccia
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Frederic Becue
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Franck Poitiers
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Brian Swanson
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Lisa Cowan
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - William J Sasiela
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Howard K Surks
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.)
| | - Henry N Ginsberg
- From Columbia University College of Physicians and Surgeons, New York (G.R.-S., M.P., C.N., T.T., S.H., R.R., W.K., R.N., N.F., H.N.G.); The City University of New York (J.O.); Northwest Lipid Metabolism and Diabetes Research Laboratories, University of Washington, Seattle (S.M.M.); Cardiovascular Nutrition Laboratory, JM USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA (A.H.L., N.R.M.); Sanofi, Bridgewater, NJ (J.M., B.S., L.C., H.K.S.); Umanis, Levallois-Perret, France (M.M.); Sanofi, Montpellier, France (F.B.); Sanofi, Paris, France (F.P.); and Regeneron Pharmaceuticals, Inc., Tarrytown, NY (W.J.S.).
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33
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SRM-based measurements of proprotein convertase subtilisin/kexin type 9 and lipoprotein(a) kinetics in nonhuman primate serum. Bioanalysis 2016; 8:2551-2563. [DOI: 10.4155/bio-2016-0146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: PCSK9 and Lp(a) have been identified as potential biomarkers for cardiovascular disease. The ability to measure protein turnover rates will provide insights into the dynamic properties of these proteins and lead to better understanding of their biological roles. We aimed to implement the stable isotope-labeled tracers ([2H3]-leucine) and develop a novel LC-selected reaction monitoring (SRM) mass spectrometry (MS) method to study the kinetics of PCSK9 and Lp(a). Results: A sensitive method using immunoaffinity enrichment coupled with LC-SRM MS was developed to measure the production and degradation rates of PCSK9 and Lp(a) in naive nonhuman primate serum. Comparable results were obtained from two different routes of tracer administration. Conclusion: Immunoaffinity enrichment coupled with LC-SRM MS demonstrated success in in vivo kinetic measurements of proteins with relatively slow turnover rate (Lp[a]) or low abundance (PCSK9) in serum.
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34
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Kotani K, Serban MC, Penson P, Lippi G, Banach M. Evidence-based assessment of lipoprotein(a) as a risk biomarker for cardiovascular diseases - Some answers and still many questions. Crit Rev Clin Lab Sci 2016; 53:370-8. [PMID: 27173621 DOI: 10.1080/10408363.2016.1188055] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The present article is aimed at outlining the current state of knowledge regarding the clinical value of lipoprotein(a) (Lp(a)) as a marker of cardiovascular disease (CVD) risk by summarizing the results of recent clinical studies, meta-analyses and systematic reviews. The literature supports the predictive value of Lp(a) on CVD outcomes, although the effect size is modest. Lp(a) would also appear to have an effect on cerebrovascular outcomes, however the effect appears even smaller than that for CVD outcomes. Consideration of apolipoprotein(a) (apo(a)) isoforms and LPA genetics in relation to the simple assessment of Lp(a) concentration may enhance clinical practice in vascular medicine. We also describe recent advances in Lp(a) research (including therapies) and highlight areas where further research is needed such as the measurement of Lp(a) and its involvement in additional pathophysiological processes.
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Affiliation(s)
- Kazuhiko Kotani
- a Division of Community and Family MedicinevJichi Medical University , Shimotsuke-City , Japan .,b Department of Clinical Laboratory Medicine , Jichi Medical University , Shimotsuke-City , Japan
| | - Maria-Corina Serban
- c Department of Epidemiology , University of Alabama at Birmingham , Birmingham , AL , USA .,d Department of Functional Sciences , Discipline of Pathophysiology, "Victor Babes" University of Medicine and Pharmacy , Timisoara , Romania
| | - Peter Penson
- e Section of Clinical Biochemistry , School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University , Liverpool , UK
| | - Giuseppe Lippi
- f Section of Clinical Biochemistry , University of Verona , Verona , Italy , and
| | - Maciej Banach
- g Department of Hypertension , Chair of Nephrology and Hypertension, Medical University of Lodz , Lodz , Poland
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