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Bao X, Liang Y, Chang H, Cai T, Feng B, Gordon K, Zhu Y, Shi H, He Y, Xie L. Targeting proprotein convertase subtilisin/kexin type 9 (PCSK9): from bench to bedside. Signal Transduct Target Ther 2024; 9:13. [PMID: 38185721 PMCID: PMC10772138 DOI: 10.1038/s41392-023-01690-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 09/27/2023] [Accepted: 10/27/2023] [Indexed: 01/09/2024] Open
Abstract
Proprotein convertase subtilisin/kexin type 9 (PCSK9) has evolved as a pivotal enzyme in lipid metabolism and a revolutionary therapeutic target for hypercholesterolemia and its related cardiovascular diseases (CVD). This comprehensive review delineates the intricate roles and wide-ranging implications of PCSK9, extending beyond CVD to emphasize its significance in diverse physiological and pathological states, including liver diseases, infectious diseases, autoimmune disorders, and notably, cancer. Our exploration offers insights into the interaction between PCSK9 and low-density lipoprotein receptors (LDLRs), elucidating its substantial impact on cholesterol homeostasis and cardiovascular health. It also details the evolution of PCSK9-targeted therapies, translating foundational bench discoveries into bedside applications for optimized patient care. The advent and clinical approval of innovative PCSK9 inhibitory therapies (PCSK9-iTs), including three monoclonal antibodies (Evolocumab, Alirocumab, and Tafolecimab) and one small interfering RNA (siRNA, Inclisiran), have marked a significant breakthrough in cardiovascular medicine. These therapies have demonstrated unparalleled efficacy in mitigating hypercholesterolemia, reducing cardiovascular risks, and have showcased profound value in clinical applications, offering novel therapeutic avenues and a promising future in personalized medicine for cardiovascular disorders. Furthermore, emerging research, inclusive of our findings, unveils PCSK9's potential role as a pivotal indicator for cancer prognosis and its prospective application as a transformative target for cancer treatment. This review also highlights PCSK9's aberrant expression in various cancer forms, its association with cancer prognosis, and its crucial roles in carcinogenesis and cancer immunity. In conclusion, this synthesized review integrates existing knowledge and novel insights on PCSK9, providing a holistic perspective on its transformative impact in reshaping therapeutic paradigms across various disorders. It emphasizes the clinical value and effect of PCSK9-iT, underscoring its potential in advancing the landscape of biomedical research and its capabilities in heralding new eras in personalized medicine.
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Affiliation(s)
- Xuhui Bao
- Institute of Therapeutic Cancer Vaccines, Fudan University Pudong Medical Center, Shanghai, China.
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, China.
- Department of Oncology, Fudan University Pudong Medical Center, Shanghai, China.
- Center for Clinical Research, Fudan University Pudong Medical Center, Shanghai, China.
- Clinical Research Center for Cell-based Immunotherapy, Fudan University, Shanghai, China.
- Department of Pathology, Duke University Medical Center, Durham, NC, USA.
| | - Yongjun Liang
- Center for Medical Research and Innovation, Fudan University Pudong Medical Center, Shanghai, China
| | - Hanman Chang
- Institute for Food Safety and Health, Illinois Institute of Technology, Chicago, IL, USA
| | - Tianji Cai
- Department of Sociology, University of Macau, Taipa, Macau, China
| | - Baijie Feng
- Department of Oncology, Fudan University Pudong Medical Center, Shanghai, China
| | - Konstantin Gordon
- Medical Institute, Peoples' Friendship University of Russia, Moscow, Russia
- A. Tsyb Medical Radiological Research Center, Obninsk, Russia
| | - Yuekun Zhu
- Department of Colorectal Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Hailian Shi
- Shanghai Key Laboratory of Compound Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Zhangjiang Hi-tech Park, Shanghai, China
| | - Yundong He
- Shanghai Key Laboratory of Regulatory Biology, School of Life Sciences, East China Normal University, Shanghai, China.
| | - Liyi Xie
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China.
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
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Siddiqui H, Deo N, Rutledge MT, Williams MJ, Redpath GM, McCormick SP. Plasminogen Receptors Promote Lipoprotein(a) Uptake by Enhancing Surface Binding and Facilitating Macropinocytosis. Arterioscler Thromb Vasc Biol 2023; 43:1851-1866. [PMID: 37589135 PMCID: PMC10521804 DOI: 10.1161/atvbaha.123.319344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/02/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND High levels of Lp(a) (lipoprotein(a)) are associated with multiple forms of cardiovascular disease. Lp(a) consists of an apoB100-containing particle attached to the plasminogen homologue apo(a). The pathways for Lp(a) clearance are not well understood. We previously discovered that the plasminogen receptor PlgRKT (plasminogen receptor with a C-terminal lysine) promoted Lp(a) uptake in liver cells. Here, we aimed to further define the role of PlgRKT and to investigate the role of 2 other plasminogen receptors, annexin A2 and S100A10 (S100 calcium-binding protein A10) in the endocytosis of Lp(a). METHODS Human hepatocellular carcinoma (HepG2) cells and haploid human fibroblast-like (HAP1) cells were used for overexpression and knockout of plasminogen receptors. The uptake of Lp(a), LDL (low-density lipoprotein), apo(a), and endocytic cargos was visualized and quantified by confocal microscopy and Western blotting. RESULTS The uptake of both Lp(a) and apo(a), but not LDL, was significantly increased in HepG2 and HAP1 cells overexpressing PlgRKT, annexin A2, or S100A10. Conversely, Lp(a) and apo(a), but not LDL, uptake was significantly reduced in HAP1 cells in which PlgRKT and S100A10 were knocked out. Surface binding studies in HepG2 cells showed that overexpression of PlgRKT, but not annexin A2 or S100A10, increased Lp(a) and apo(a) plasma membrane binding. Annexin A2 and S100A10, on the other hand, appeared to regulate macropinocytosis with both proteins significantly increasing the uptake of the macropinocytosis marker dextran when overexpressed in HepG2 and HAP1 cells and knockout of S100A10 significantly reducing dextran uptake. Bringing these observations together, we tested the effect of a PI3K (phosphoinositide-3-kinase) inhibitor, known to inhibit macropinocytosis, on Lp(a) uptake. Results showed a concentration-dependent reduction confirming that Lp(a) uptake was indeed mediated by macropinocytosis. CONCLUSIONS These findings uncover a novel pathway for Lp(a) endocytosis involving multiple plasminogen receptors that enhance surface binding and stimulate macropinocytosis of Lp(a). Although the findings were produced in cell culture models that have limitations, they could have clinical relevance since drugs that inhibit macropinocytosis are in clinical use, that is, the PI3K inhibitors for cancer therapy and some antidepressant compounds.
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Affiliation(s)
- Halima Siddiqui
- Department of Biochemistry (H.S., N.D., M.T.R., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
| | - Nikita Deo
- Department of Biochemistry (H.S., N.D., M.T.R., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
| | - Malcolm T. Rutledge
- Department of Biochemistry (H.S., N.D., M.T.R., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
| | - Michael J.A. Williams
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- Department of Medicine (M.J.A.W.), Dunedin School of Medicine, University of Otago, New Zealand
| | - Gregory M.I. Redpath
- Department of Biochemistry (H.S., N.D., M.T.R., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
| | - Sally P.A. McCormick
- Department of Biochemistry (H.S., N.D., M.T.R., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
- School of Biomedical Sciences, HeartOtago (H.S., N.D., M.T.R., M.J.A.W., G.M.I.R., S.P.A.M.), Dunedin School of Medicine, University of Otago, New Zealand
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Koschinsky ML, Stroes ESG, Kronenberg F. Daring to dream: Targeting lipoprotein(a) as a causal and risk-enhancing factor. Pharmacol Res 2023; 194:106843. [PMID: 37406784 DOI: 10.1016/j.phrs.2023.106843] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 06/15/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
Lipoprotein(a) [Lp(a)], a distinct lipoprotein class, has become a major focus for cardiovascular research. This review is written in light of the recent guideline and consensus statements on Lp(a) and focuses on 1) the causal association between Lp(a) and cardiovascular outcomes, 2) the potential mechanisms by which elevated Lp(a) contributes to cardiovascular diseases, 3) the metabolic insights on the production and clearance of Lp(a) and 4) the current and future therapeutic approaches to lower Lp(a) concentrations. The concentrations of Lp(a) are under strict genetic control. There exists a continuous relationship between the Lp(a) concentrations and risk for various endpoints of atherosclerotic cardiovascular disease (ASCVD). One in five people in the Caucasian population is considered to have increased Lp(a) concentrations; the prevalence of elevated Lp(a) is even higher in black populations. This makes Lp(a) a cardiovascular risk factor of major public health relevance. Besides the association between Lp(a) and myocardial infarction, the relationship with aortic valve stenosis has become a major focus of research during the last decade. Genetic studies provided strong support for a causal association between Lp(a) and cardiovascular outcomes: carriers of genetic variants associated with lifelong increased Lp(a) concentration are significantly more frequent in patients with ASCVD. This has triggered the development of drugs that can specifically lower Lp(a) concentrations: mRNA-targeting therapies such as anti-sense oligonucleotide (ASO) therapies and short interfering RNA (siRNA) therapies have opened new avenues to lower Lp(a) concentrations more than 95%. Ongoing Phase II and III clinical trials of these compounds are discussed in this review.
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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; Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Erik S G Stroes
- Department of Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | - Florian Kronenberg
- Institute of Genetic Epidemiology, Medical University of Innsbruck, Innsbruck, Austria.
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Roubtsova A, Scipione CA, Garçon D, Boffa MB, Seidah NG, Koschinsky ML, Prat A. Surface LDLR is a major receptor for lipoprotein(a) clearance in male mice lacking PCSK9. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159288. [PMID: 36708961 DOI: 10.1016/j.bbalip.2023.159288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/18/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023]
Affiliation(s)
- Anna Roubtsova
- Institut de Recherches Cliniques de Montréal (IRCM), Université de Montréal, Montreal, QC, Canada
| | - Corey A Scipione
- Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Damien Garçon
- Institut de Recherches Cliniques de Montréal (IRCM), Université de Montréal, Montreal, QC, Canada
| | - Michael B Boffa
- Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Nabil G Seidah
- Institut de Recherches Cliniques de Montréal (IRCM), Université de Montréal, Montreal, QC, Canada
| | - Marlys L Koschinsky
- Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Annik Prat
- Institut de Recherches Cliniques de Montréal (IRCM), Université de Montréal, Montreal, QC, Canada.
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Xu J, Zhu L, Xie Y, Zhang M, Xiao Z, Su R, Wen T, Liu L. Effects of Xuezhikang versus Pravastatin on Triglyceride Level in Patients with T2DM and Dyslipidemia: Study Protocol for a Multicenter Randomized Controlled Trial. Curr Vasc Pharmacol 2023; 21:211-217. [PMID: 36998136 PMCID: PMC10514502 DOI: 10.2174/1570161121666230328110215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 04/01/2023]
Abstract
BACKGROUND Hypertriglyceridemia, is commonly found in patients with diabetes. Xuezhikang, an extract of red yeast rice, is effective in reducing cardiovascular events in Chinese patients with diabetes and coronary heart disease (CHD). Xuezhikang has been reported to significantly decrease the level of triglycerides (TG), a potential causal risk factor for myocardial infarction. On the basis of a similar reduction in low-density lipoprotein cholesterol, this study will evaluate the effect of xuezhikang on TG levels compared with pravastatin in patients with type 2 diabetes mellitus (T2DM) and dyslipidemia. METHODS This is an open-label, multicenter, randomized controlled study to assess the effects of xuezhikang (1.2 g/day) and pravastatin (20 mg/day) on TG and other blood lipid parameters in patients with T2DM and dyslipidemia. A total of 114 patients will be enrolled and randomly assigned 1:1 to receive xuezhikang or pravastatin treatment for 6 weeks. RESULT The primary outcome measure is the change from baseline in fasting TG levels after 6 weeks. The change from baseline in other fasting and postprandial lipid parameters, and glucose profiles at 1, 2, and 4 h after a nutritious breakfast will also be explored. CONCLUSION This study will evaluate the effect of a 6-week treatment with xuezhikang compared with pravastatin on fasting and postprandial TG levels and other blood lipid parameters in patients with T2DM and dyslipidemia without atherosclerotic cardiovascular disease (ASCVD). The results will provide more information on optimizing the lipid control of patients with diabetes in the primary prevention of ASCVD.
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Affiliation(s)
- Jin Xu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Liyuan Zhu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Yingying Xie
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Miao Zhang
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Zixi Xiao
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Rongkai Su
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
| | - Tie Wen
- Department of Emergency Medicine, Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Emergency Medicine and Difficult Diseases Institute, Second Xiangya Hospital, Central South University, Hunan, 410011, China
| | - Ling Liu
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Hunan, 410011, China
- Research Institute of Blood Lipid and Atherosclerosis, Central South University, Hunan, 410011, China
- Modern Cardiovascular Disease Clinical Technology Research Center of Hunan Province, Hunan, 410011, China
- Cardiovascular Disease Research Center of Hunan Province, Hunan, 410011, China
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de Boer LM, Wiegman A, Swerdlow DI, Kastelein JJP, Hutten BA. Pharmacotherapy for children with elevated levels of lipoprotein(a): future directions. Expert Opin Pharmacother 2022; 23:1601-1615. [PMID: 36047306 DOI: 10.1080/14656566.2022.2118522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Elevated lipoprotein(a) [Lp(a)] is an independent risk factor for atherosclerotic cardiovascular disease (ASCVD). With the advent of the antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) targeted at LPA, the gene encoding apolipoprotein(a), that are highly effective for lowering Lp(a) levels, this risk factor might be managed in the near future. Given that Lp(a) levels are mostly genetically determined and once elevated, present from early age, we have evaluated future directions for the treatment of children with high Lp(a) levels. AREAS COVERED In the current review, we discuss different pharmacological treatments in clinical development and provide an in-depth overview of the effects of ASOs and siRNAs targeted at LPA. EXPERT OPINION Since high Lp(a) is an important risk factor for ASCVD and given the promising effects of both ASOs and siRNAs targeted at apo(a), there is an urgent need for well-designed prospective studies to assess the impact of elevated Lp(a) in childhood. If the Lp(a)-hypothesis is confirmed in adults, and also in children, the rationale might arise for treating children with high Lp(a) levels. However, we feel that this should be limited to children with the highest cardiovascular risk including familial hypercholesterolemia and potentially pediatric stroke.
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Affiliation(s)
- Lotte M de Boer
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands.,Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Albert Wiegman
- Department of Pediatrics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | | | - John J P Kastelein
- Department of Vascular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Barbara A Hutten
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
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Ying Q, Chan DC, Pang J, Marcovina SM, Barrett PHR, Watts GF. PCSK9 inhibition with alirocumab decreases plasma lipoprotein(a) concentration by a dual mechanism of action in statin-treated patients with very high apolipoprotein(a) concentration. J Intern Med 2022; 291:870-876. [PMID: 35112754 DOI: 10.1111/joim.13457] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Inhibition of proprotein convertase subtilisin/kexin type 9 with alirocumab decreases plasma lipoprotein(a) [Lp(a)] levels. The kinetic mechanism for lowering Lp(a) by alirocumab may differ according to pre-treatment apolipoprotein(a) [apo(a)] levels. METHODS The effect of 12-week alirocumab (150 mg subcutaneously fortnightly) on the kinetics of apo(a) was compared in statin-treated patients with high (n = 10) and very high Lp(a) concentrations (n = 11). RESULTS In patients with high apo(a) concentrations, alirocumab lowered plasma apo(a) pool size (-17%, p < 0.01) chiefly by increasing the fractional catabolic rate (FCR) of apo(a) (+27%, p < 0.001). By contrast in patients with very high apo(a) concentrations, alirocumab significantly lowered plasma apo(a) pool size (-32%, p < 0.001) by both increasing apo(a) FCR (+30%, p < 0.001) and lowering production rate (-11%, p < 0.05). CONCLUSIONS In statin-treated patients with very high apo(a) concentrations, alirocumab lowers plasma Lp(a) concentration by a dual mode of action that increases the clearance and decreases the production of Lp(a) particles.
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Affiliation(s)
- Qidi Ying
- Faculty of Health and Medical Sciences, Medical School, University of Western Australia, Perth, Western Australia, Australia
| | - Dick C Chan
- Faculty of Health and Medical Sciences, Medical School, University of Western Australia, Perth, Western Australia, Australia
| | - Jing Pang
- Faculty of Health and Medical Sciences, Medical School, University of Western Australia, Perth, Western Australia, Australia
| | | | - Peter Hugh R Barrett
- Faculty of Medicine and Health, University of New England, Armidale, New South Wales, Australia
| | - Gerald F Watts
- Faculty of Health and Medical Sciences, Medical School, University of Western Australia, Perth, Western Australia, Australia.,Department of Cardiology and Internal Medicine, Lipid Disorders Clinic, Royal Perth Hospital, Perth, Western Australia, Australia
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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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Abstract
This article reviews the discovery of PCSK9, its structure-function characteristics, and its presently known and proposed novel biological functions. The major critical function of PCSK9 deduced from human and mouse studies, as well as cellular and structural analyses, is its role in increasing the levels of circulating low-density lipoprotein (LDL)-cholesterol (LDLc), via its ability to enhance the sorting and escort of the cell surface LDL receptor (LDLR) to lysosomes. This implicates the binding of the catalytic domain of PCSK9 to the EGF-A domain of the LDLR. This also requires the presence of the C-terminal Cys/His-rich domain, its binding to the secreted cytosolic cyclase associated protein 1, and possibly another membrane-bound "protein X". Curiously, in PCSK9-deficient mice, an alternative to the downregulation of the surface levels of the LDLR by PCSK9 is taking place in the liver of female mice in a 17β-estradiol-dependent manner by still an unknown mechanism. Recent studies have extended our understanding of the biological functions of PCSK9, namely its implication in septic shock, vascular inflammation, viral infections (Dengue; SARS-CoV-2) or immune checkpoint modulation in cancer via the regulation of the cell surface levels of the T-cell receptor and MHC-I, which govern the antitumoral activity of CD8+ T cells. Because PCSK9 inhibition may be advantageous in these processes, the availability of injectable safe PCSK9 inhibitors that reduces by 50% to 60% LDLc above the effect of statins is highly valuable. Indeed, injectable PCSK9 monoclonal antibody or small interfering RNA could be added to current immunotherapies in cancer/metastasis.
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Affiliation(s)
- Nabil G Seidah
- Laboratory of Biochemical Neuroendocrinology, Montreal Clinical Research Institute (IRCM, affiliated to the University of Montreal), Montreal, QC, Canada
| | - Annik Prat
- Laboratory of Biochemical Neuroendocrinology, Montreal Clinical Research Institute (IRCM, affiliated to the University of Montreal), Montreal, QC, Canada
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Chemello K, Chan DC, Lambert G, Watts GF. Recent advances in demystifying the metabolism of lipoprotein(a). Atherosclerosis 2022; 349:82-91. [DOI: 10.1016/j.atherosclerosis.2022.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 12/24/2022]
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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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12
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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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13
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Siddiqui H, Yevstigneyev N, Madani G, McCormick S. Approaches to Visualising Endocytosis of LDL-Related Lipoproteins. Biomolecules 2022; 12:biom12020158. [PMID: 35204658 PMCID: PMC8961563 DOI: 10.3390/biom12020158] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/20/2021] [Accepted: 01/12/2022] [Indexed: 02/04/2023] Open
Abstract
Endocytosis is the process by which molecules are actively transported into cells. It can take on a variety of forms depending on the cellular machinery involved ranging from specific receptor-mediated endocytosis to the less selective and actin-driven macropinocytosis. The plasma lipoproteins, which deliver lipids and other cargo to cells, have been intensely studied with respect to their endocytic uptake. One of the first molecules to be visualised undergoing endocytosis via a receptor-mediated, clathrin-dependent pathway was low-density lipoprotein (LDL). The LDL molecule has subsequently been shown to be internalised through multiple endocytic pathways. Dissecting the pathways of lipoprotein endocytosis has been crucial to understanding the regulation of plasma lipid levels and how lipids enter cells in the arterial wall to promote atherosclerosis. It has also aided understanding of the dysregulation that occurs in plasma lipid levels when molecules involved in uptake are defective, as is the case in familial hypercholesterolemia (FH). The aim of this review is to outline the many endocytic pathways utilised for lipoprotein uptake. It explores the various experimental approaches that have been applied to visualise lipoprotein endocytosis with an emphasis on LDL and its more complex counterpart, lipoprotein(a) [Lp(a)]. Finally, we look at new developments in lipoprotein visualisation that hold promise for scrutinising endocytic pathways to finer detail in the future.
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Affiliation(s)
- Halima Siddiqui
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Nikita Yevstigneyev
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Golnoush Madani
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
| | - Sally McCormick
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand; (H.S.); (N.Y.); (G.M.)
- HeartOtago, School of Biomedical Sciences, University of Otago, Dunedin 9016, New Zealand
- Correspondence:
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14
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Durlach V, Bonnefont-Rousselot D, Boccara F, Varret M, Di-Filippo Charcosset M, Cariou B, Valero R, Charriere S, Farnier M, Morange PE, Meilhac O, Lambert G, Moulin P, Gillery P, Beliard-Lasserre S, Bruckert E, Carrié A, Ferrières J, Collet X, Chapman MJ, Anglés-Cano E. Lipoprotein(a): Pathophysiology, measurement, indication and treatment in cardiovascular disease. A consensus statement from the Nouvelle Société Francophone d'Athérosclérose (NSFA). Arch Cardiovasc Dis 2021; 114:828-847. [PMID: 34840125 DOI: 10.1016/j.acvd.2021.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/16/2021] [Accepted: 10/18/2021] [Indexed: 10/19/2022]
Abstract
Lipoprotein(a) is an apolipoprotein B100-containing low-density lipoprotein-like particle that is rich in cholesterol, and is associated with a second major protein, apolipoprotein(a). Apolipoprotein(a) possesses structural similarity to plasminogen but lacks fibrinolytic activity. As a consequence of its composite structure, lipoprotein(a) may: (1) elicit a prothrombotic/antifibrinolytic action favouring clot stability; and (2) enhance atherosclerosis progression via its propensity for retention in the arterial intima, with deposition of its cholesterol load at sites of plaque formation. Equally, lipoprotein(a) may induce inflammation and calcification in the aortic leaflet valve interstitium, leading to calcific aortic valve stenosis. Experimental, epidemiological and genetic evidence support the contention that elevated concentrations of lipoprotein(a) are causally related to atherothrombotic risk and equally to calcific aortic valve stenosis. The plasma concentration of lipoprotein(a) is principally determined by genetic factors, is not influenced by dietary habits, remains essentially constant over the lifetime of a given individual and is the most powerful variable for prediction of lipoprotein(a)-associated cardiovascular risk. However, major interindividual variations (up to 1000-fold) are characteristic of lipoprotein(a) concentrations. In this context, lipoprotein(a) assays, although currently insufficiently standardized, are of considerable interest, not only in stratifying cardiovascular risk, but equally in the clinical follow-up of patients treated with novel lipid-lowering therapies targeted at lipoprotein(a) (e.g. antiapolipoprotein(a) antisense oligonucleotides and small interfering ribonucleic acids) that markedly reduce circulating lipoprotein(a) concentrations. We recommend that lipoprotein(a) be measured once in subjects at high cardiovascular risk with premature coronary heart disease, in familial hypercholesterolaemia, in those with a family history of coronary heart disease and in those with recurrent coronary heart disease despite lipid-lowering treatment. Because of its clinical relevance, the cost of lipoprotein(a) testing should be covered by social security and health authorities.
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Affiliation(s)
- Vincent Durlach
- Champagne-Ardenne University, UMR CNRS 7369 MEDyC & Cardio-Thoracic Department, Reims University Hospital, 51092 Reims, France
| | - Dominique Bonnefont-Rousselot
- Metabolic Biochemistry Department, Hôpital Pitié-Salpêtrière, AP-HP, 75013 Paris, France; Université de Paris, CNRS, INSERM, UTCBS, 75006 Paris, France
| | - Franck Boccara
- Sorbonne University, GRC n(o) 22, C(2)MV, INSERM UMR_S 938, Centre de Recherche Saint-Antoine, IHU ICAN, 75012 Paris, France; Service de Cardiologie, Hôpital Saint-Antoine, AP-HP, 75012 Paris, France
| | - Mathilde Varret
- Laboratory for Vascular Translational Science (LVTS), INSERM U1148, Centre Hospitalier Universitaire Xavier Bichat, 75018 Paris, France; Université de Paris, 75018 Paris, France
| | - Mathilde Di-Filippo Charcosset
- Hospices Civils de Lyon, UF Dyslipidémies, 69677 Bron, France; Laboratoire CarMen, INSERM, INRA, INSA, Université Claude-Bernard Lyon 1, 69495 Pierre-Bénite, France
| | - Bertrand Cariou
- Université de Nantes, CHU Nantes, CNRS, INSERM, l'Institut du Thorax, 44000 Nantes, France
| | - René Valero
- Endocrinology Department, La Conception Hospital, AP-HM, Aix-Marseille University, INSERM, INRAE, C2VN, 13005 Marseille, France
| | - Sybil Charriere
- Hospices Civils de Lyon, INSERM U1060, Laboratoire CarMeN, Université Lyon 1, 69310 Pierre-Bénite, France
| | - Michel Farnier
- PEC2, EA 7460, University of Bourgogne Franche-Comté, 21079 Dijon, France; Department of Cardiology, CHU Dijon Bourgogne, 21000 Dijon, France
| | - Pierre E Morange
- Aix-Marseille University, INSERM, INRAE, C2VN, 13385 Marseille, France
| | - Olivier Meilhac
- INSERM, UMR 1188 DéTROI, Université de La Réunion, 97744 Saint-Denis de La Réunion, Reunion; CHU de La Réunion, CIC-EC 1410, 97448 Saint-Pierre, Reunion
| | - Gilles Lambert
- INSERM, UMR 1188 DéTROI, Université de La Réunion, 97744 Saint-Denis de La Réunion, Reunion; CHU de La Réunion, CIC-EC 1410, 97448 Saint-Pierre, Reunion
| | - Philippe Moulin
- Hospices Civils de Lyon, INSERM U1060, Laboratoire CarMeN, Université Lyon 1, 69310 Pierre-Bénite, France
| | - Philippe Gillery
- Laboratory of Biochemistry-Pharmacology-Toxicology, Reims University Hospital, University of Reims Champagne-Ardenne, UMR CNRS/URCA n(o) 7369, 51092 Reims, France
| | - Sophie Beliard-Lasserre
- Endocrinology Department, La Conception Hospital, AP-HM, Aix-Marseille University, INSERM, INRAE, C2VN, 13005 Marseille, France
| | - Eric Bruckert
- Service d'Endocrinologie-Métabolisme, Hôpital Pitié-Salpêtrière, AP-HP, 75013 Paris, France; IHU ICAN, Sorbonne University, 75013 Paris, France
| | - Alain Carrié
- Sorbonne University, UMR INSERM 1166, IHU ICAN, Laboratory of Endocrine and Oncological Biochemistry, Obesity and Dyslipidaemia Genetic Unit, Hôpital Pitié-Salpêtrière, AP-HP, 75013 Paris, France
| | - Jean Ferrières
- Department of Cardiology and INSERM UMR 1295, Rangueil University Hospital, TSA 50032, 31059 Toulouse, France
| | - Xavier Collet
- INSERM U1048, Institute of Metabolic and Cardiovascular Diseases, Rangueil University Hospital, BP 84225, 31432 Toulouse, France
| | - M John Chapman
- Sorbonne University, Hôpital Pitié-Salpêtrière and National Institute for Health and Medical Research (INSERM), 75013 Paris, France
| | - Eduardo Anglés-Cano
- Université de Paris, INSERM, Innovative Therapies in Haemostasis, 75006 Paris, France.
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15
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Blanchard V, Chemello K, Hollstein T, Hong-Fong CC, Schumann F, Grenkowitz T, Nativel B, Coassin S, Croyal M, Kassner U, Lamina C, Steinhagen-Thiessen E, Lambert G. The size of apolipoprotein (a) is an independent determinant of the reduction in lipoprotein (a) induced by PCSK9 inhibitors. Cardiovasc Res 2021; 118:2103-2111. [PMID: 34314498 DOI: 10.1093/cvr/cvab247] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 07/24/2021] [Indexed: 12/14/2022] Open
Abstract
AIMS Lipoprotein (a) [Lp(a)] is a lipoprotein species causatively associated with atherosclerosis. Unlike statins, PCSK9 inhibitors (PCSK9i) reduce Lp(a), but this reduction is highly variable. Levels of Lp(a) are chiefly governed by the size of its signature protein, apolipoprotein (a) [apo(a)]. Whether this parameter determines some of the reduction in Lp(a) induced by PCSK9i remains unknown. We aimed to investigate if the Lp(a) lowering efficacy of PCSK9i is modulated by the size of apo(a), which is genetically determined by the variable number of KIV domains present on that protein. METHODS AND RESULTS The levels of Lp(a) and the size of apo(a) were assessed in plasma samples from 268 patients before and after treatment with PCSK9i. Patients were recruited at the Outpatient Lipid Clinic of the Charité Hospital (Berlin) between 2015 and 2020. They were hypercholesterolemic at very high CVD risk with LDL-cholesterol levels above therapeutic targets despite maximally tolerated lipid-lowering therapy. Patients received either Alirocumab (75 or 150 mg) or Evolocumab (140 mg) every 2 weeks. Apo(a), apoB100, and apoE concentrations as well as apoE major isoforms were determined by liquid chromatography high-resolution mass spectrometry. Apo(a) isoforms sizes were determined by Western Blot. PCSK9i sharply reduced LDL-cholesterol (-57%), apoB100 (-47%) and Lp(a) (-36%). There was a positive correlation between the size of apo(a) and the relative reduction in Lp(a) induced by PCSK9i (r = 0.363, p = 0.0001). The strength of this association remained unaltered after adjustment for baseline Lp(a) levels and all other potential confounding factors. In patients with two detectable apo(a) isoforms, there was also a positive correlation between the size of apo(a) and the reduction in Lp(a), separately for the smaller (r = 0.350, p = 0.0001) and larger (r = 0.324, p = 0.0003) isoforms. The relative contribution of the larger isoform to the total concentration of apo(a) was reduced from 29% to 15% (p < 0.0001). CONCLUSIONS The size of apo(a) is an independent determinant of the response to PCSK9i. Each additional kringle domain is associated with a 3% additional reduction in Lp(a). This explains in part the variable efficacy of PCSK9i and allows to identify patients who will benefit most from these therapies in terms of Lp(a) lowering. TRANSLATIONAL PERSPECTIVE Unlike statins, PCSK9 inhibitors reduce the circulating levels of the highly atherogenic Lipoprotein (a). The underlying mechanism remains a matter of considerable debate. The size of apo(a), the signature protein of Lp(a), is extremely variable (300 to more than 800 kDa) and depends on its number of kringle domains. We now show that each increase in apo(a) size by one kringle domain is associated with a 3% additional reduction in Lp(a) following PCSK9i treatment and that apo(a) size polymorphism is an independent predictor of the reduction in Lp(a) induced by these drugs. In an era of personalized medicine, this allows to identify patients who will benefit most from PCSK9i in terms of Lp(a) lowering.
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Affiliation(s)
- Valentin Blanchard
- Université de La Réunion, INSERM UMR 1188 DéTROI, Sainte-Clotilde, France.,Centre for Heart & Lung Innovation, St. Paul's Hospital, Vancouver, Canada; Department of Medicine, UBC, Vancouver, Canada
| | - Kévin Chemello
- Université de La Réunion, INSERM UMR 1188 DéTROI, Sainte-Clotilde, France
| | - Tim Hollstein
- Department of Endocrinology, Campus Virchow-Klinikum, Charité Universitätsmedizin, Berlin, Germany.,Division of Endocrinology, Diabetology and Clinical Nutrition, Department of Internal Medicine 1, University of Kiel, Kiel, Germany
| | | | - Friederike Schumann
- Department of Endocrinology, Campus Virchow-Klinikum, Charité Universitätsmedizin, Berlin, Germany
| | - Thomas Grenkowitz
- Department of Endocrinology, Campus Virchow-Klinikum, Charité Universitätsmedizin, Berlin, Germany
| | - Brice Nativel
- Université de La Réunion, INSERM UMR 1188 DéTROI, Sainte-Clotilde, France
| | - Stefan Coassin
- Institute of Genetic Epidemiology, Department of Genetics and Pharmacology, Medical University of Innsbrück, Innsbrück, Austria
| | - Mikaël Croyal
- NUN, INRA, CHU Nantes, UMR 1280, PhAN, IMAD, CRNH-O, Nantes, France
| | - Ursula Kassner
- Department of Endocrinology, Campus Virchow-Klinikum, Charité Universitätsmedizin, Berlin, Germany
| | - Claudia Lamina
- Institute of Genetic Epidemiology, Department of Genetics and Pharmacology, Medical University of Innsbrück, Innsbrück, Austria
| | | | - Gilles Lambert
- Université de La Réunion, INSERM UMR 1188 DéTROI, Sainte-Clotilde, France
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16
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Effect of Evolocumab on Lipoprotein(a) and PCSK9 in Healthy Individuals with Elevated Lipoprotein(a) Level. J Cardiovasc Dev Dis 2020; 7:jcdd7040045. [PMID: 33076542 PMCID: PMC7712661 DOI: 10.3390/jcdd7040045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/15/2020] [Accepted: 10/09/2020] [Indexed: 12/21/2022] Open
Abstract
Background and aims: The aim of this study was to investigate the influence of a single injection of Evolocumab on the dynamics of Lp(a), fractions of apoB100-containing lipoproteins, PCSK9, and their complexes in healthy individuals with elevated Lp(a) levels. Methods: This open-label, 4-week clinical study involved 10 statin-naive volunteers with Lp(a) >30 mg/dL, LDL-C < 4.9 mmol/L, and a moderate risk of cardiovascular events. The concentrations of Lp(a), lipids, PCSK9, circulating immune complexes (CIC), and plasma complexes of PCSK9 with apoB100-containing lipoproteins (Lp(a)–PCSK9 and LDL–PCSK9) were measured before and each week after Evolocumab (MABs) administration. Results: After a single dose injection of 140 mg of MABs, the median concentration of PCSK9 in serum increased from 496 to 3944 ng/mL; however, the entire pool of circulating PCSK9 remained bound with MABs for 2–3 weeks. LDL-C level decreased significantly from 3.36 mmol/L to 2.27 mmol/L during the first two weeks after the injection. Lp(a) concentrations demonstrated multidirectional changes in different patients with the maximal decrease on the second week. There were no positive correlations between the changes in levels of Lp(a), LDL-C, and TC. The change in the amount of circulating complex of PCSK9–Lp(a) was significantly less than of PCSK9–apoB100 (−5% and −47% after 1 week, respectively). Conclusions: A single administration of monoclonal antibodies against PCSK9 (Evolocumab) in healthy individuals with hyperlipoproteinemia(a) resulted in a decrease of Lp(a) of 14%, a 5% decrease in PCSK9–Lp(a), a 36% reduction of LDL-C, a 47% decrease in PCSK9–apoB100 and a tenfold increase in total serum PCSK9 concentration.
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17
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Circulating Complex of Lipoprotein(a) and Proprotein Convertase Subtilisin/Kexin Type 9 in the Serum Measured by ELISA. Bull Exp Biol Med 2020; 169:639-643. [PMID: 32979126 DOI: 10.1007/s10517-020-04944-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Indexed: 12/21/2022]
Abstract
The presence of a complex of lipoprotein(a) and proprotein convertase subtilisin/kexin type 9 (PCSK9) in the blood of healthy volunteers and patients with cardiovascular diseases was analyzed by ELISA. The levels of the complex varied in a wide range and did not depend on the concentrations of Lp(a) and PCSK9. Moreover, the complex was found not only in patients with cardiovascular diseases, but also in healthy volunteers, which can indicate physiological role of lipoprotein(a) as PCSK9 transporter.
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18
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Chemello K, Beeské S, Trang Tran TT, Blanchard V, Villard EF, Poirier B, Le Bail JC, Dargazanli G, Ho-Van-Guimbal S, Boulay D, Bergis O, Pruniaux MP, Croyal M, Janiak P, Guillot E, Lambert G. Lipoprotein(a) Cellular Uptake Ex Vivo and Hepatic Capture In Vivo Is Insensitive to PCSK9 Inhibition With Alirocumab. JACC Basic Transl Sci 2020; 5:549-557. [PMID: 32613143 PMCID: PMC7315184 DOI: 10.1016/j.jacbts.2020.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022]
Abstract
Modulating LDL receptor expression genetically (in familial hypercholesterolemia) or pharmacologically (using statins or the PCSK9 inhibitor alirocumab) does not alter the cellular uptake of Lp(a) in primary human lymphocytes. Lp(a) hepatic capture is not modulated by PCSK9 inhibition with alirocumab in liver-humanized mice. LDLR does not appear to play a significant role in mediating Lp(a) plasma clearance in vivo.
Lipoprotein(a) (Lp[a]) is the most common genetically inherited risk factor for cardiovascular disease. Many aspects of Lp(a) metabolism remain unknown. We assessed the uptake of fluorescent Lp(a) in primary human lymphocytes as well as Lp(a) hepatic capture in a mouse model in which endogenous hepatocytes have been ablated and replaced with human ones. Modulation of LDLR expression with the PCSK9 inhibitor alirocumab did not alter the cellular or the hepatic uptake of Lp(a), demonstrating that the LDL receptor is not a major route for Lp(a) plasma clearance. These results have clinical implications because they underpin why statins are not efficient at reducing Lp(a).
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Key Words
- 3D, 3-dimensional
- AU, arbitrary unit
- BSA, bovine serum albumin
- ELISA, enzyme-linked immunosorbent assay
- FCR, fractional catabolic rate
- FRG, Fah(−/−)Rag2(−/−)Il2rg(−/−)
- HoFH, homozygous familial hypercholesterolemia
- LC-MS/MS, liquid chromatography tandem mass spectrometry
- LDL, low-density lipoprotein
- LDL-C, low-density lipoprotein cholesterol
- LDLR, low-density lipoprotein receptor
- Lp(a), lipoprotein(a)
- MFI, mean fluorescence intensity
- PBMC, peripheral blood mononuclear cell
- PBS, phosphate-buffered saline
- PCSK9, proprotein convertase subtilisin/kexin type 9
- apoB100, apolipoprotein B100
- bodipy, boron dipyrromethene
- lipoprotein(a)
- liver-humanized mice
- low-density lipoprotein receptor
- proprotein convertase subtilisin/kexin type 9
- rPCSK9, recombinant proprotein convertase subtilisin/kexin type 9
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Affiliation(s)
- Kévin Chemello
- Laboratoire Inserm UMR 1188 DéTROI, Université de La Réunion, Sainte Clotilde, France
| | | | | | - Valentin Blanchard
- Laboratoire Inserm UMR 1188 DéTROI, Université de La Réunion, Sainte Clotilde, France
| | | | | | | | | | | | | | | | | | - Mikaël Croyal
- Université de Nantes, CRNH Ouest, Inra UMR 1280 PhAN, Nantes, France
| | | | | | - Gilles Lambert
- Laboratoire Inserm UMR 1188 DéTROI, Université de La Réunion, Sainte Clotilde, France
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19
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Maranhão RC, Pala D, Freitas FR. Lipoprotein removal mechanisms and aging: implications for the cardiovascular health of the elderly. Curr Opin Endocrinol Diabetes Obes 2020; 27:104-109. [PMID: 32011347 DOI: 10.1097/med.0000000000000529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE OF REVIEW The speed of removal from the plasma of apolipoprotein B-containing lipoproteins, for example, chylomicrons, VLDL and LDL is determinant of the plasma concentration of these lipoproteins, is influenced by genetic features and ambient factors, and has implications in atherogenesis. As aging increases the clinical complications of atherosclerosis, it is important to appraise the status of the removal mechanisms in elderly individuals. RECENT FINDINGS Removal of triglyceride-rich lipoproteins remnants is delayed but the triglyceride breakdown is unchanged in elderly individuals. The discovery of PCSK9, enzyme that degrades LDL receptors, and the recent observation that PCSK9 is elevated in the elderly raises another hypothesis to account for the increased LDL-cholesterol levels in the elderly. The removal of cholesterol from cells by HDL, the first step of cholesterol reverse transport is also less efficient in the elderly, which may compromise the body cholesterol homeostasis. SUMMARY Aging determines reduction of the efficiency of lipoprotein plasma removal mechanisms, which is implicated in increased incidence of cardia complications. Moreover, aging is frequently accompanied by physical activity reduction, weight gain, and metabolic disturbances that can further decrease the efficacy of the removal mechanisms. This knowledge is important for promoting cardiovascular health in the elderly and prolonging survival.
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Affiliation(s)
- Raul C Maranhão
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina
- Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Daniela Pala
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina
| | - Fatima R Freitas
- Instituto do Coracao (InCor), Hospital das Clinicas HCFMUSP, Faculdade de Medicina
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20
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Vuorio A, Watts GF, Schneider WJ, Tsimikas S, Kovanen PT. Familial hypercholesterolemia and elevated lipoprotein(a): double heritable risk and new therapeutic opportunities. J Intern Med 2020; 287:2-18. [PMID: 31858669 DOI: 10.1111/joim.12981] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Accepted: 06/20/2019] [Indexed: 12/24/2022]
Abstract
There is compelling evidence that the elevated plasma lipoprotein(a) [Lp(a)] levels increase the risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. Like low-density lipoprotein (LDL) particles, Lp(a) particles contain cholesterol and promote atherosclerosis. In addition, Lp(a) particles contain strongly proinflammatory oxidized phospholipids and a unique apoprotein, apo(a), which promotes the growth of an arterial thrombus. At least one in 250 individuals worldwide suffer from the heterozygous form of familial hypercholesterolemia (HeFH), a condition in which LDL-cholesterol (LDL-C) is significantly elevated since birth. FH-causing mutations in the LDL receptor gene demonstrate a clear gene-dosage effect on Lp(a) plasma concentrations and elevated Lp(a) levels are present in 30-50% of patients with HeFH. The cumulative burden of two genetically determined pro-atherogenic lipoproteins, LDL and Lp(a), is a potent driver of ASCVD in HeFH patients. Statins are the cornerstone of treatment of HeFH, but they do not lower the plasma concentrations of Lp(a). Emerging therapies effectively lower Lp(a) by as much as 90% using RNA-based approaches that target the transcriptional product of the LPA gene. We are now approaching the dawn of an era, in which permanent and significant lowering of the high cholesterol burden of HeFH patients can be achieved. If outcome trials of novel Lp(a)-lowering therapies prove to be safe and cost-effective, they will provide additional risk reduction needed to effectively treat HeFH and potentially lower the CVD risk in these high-risk patients even more than currently achieved with LDL-C lowering alone.
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Affiliation(s)
- A Vuorio
- From the, Mehiläinen Airport Health Centre, Vantaa, Finland.,Department of Forensic Medicine, University of Helsinki, Helsinki, Finland
| | - G F Watts
- School of Medicine, Faculty of Medicine and Health Sciences, University of Western Australia, Perth, Australia.,Lipid Disorders Clinic, Department of Cardiology, Royal Perth Hospital, Perth, Australia
| | - W J Schneider
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, Vienna, Austria
| | - S Tsimikas
- Vascular Medicine Program, Sulpizio Cardiovascular Center, Division of Cardiovascular Medicine, University of California, San Diego, CA, USA
| | - P T Kovanen
- Wihuri Research Institute, Helsinki, Finland
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21
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Apolipoprotein(a) phenotype determines the correlations of lipoprotein(a) and proprotein convertase subtilisin/kexin type 9 levels in patients with potential familial hypercholesterolemia. Atherosclerosis 2019; 277:477-482. [PMID: 30270088 DOI: 10.1016/j.atherosclerosis.2018.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/01/2018] [Accepted: 08/17/2018] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND AIMS The aim of this study is to investigate the relation between lipoprotein(a) [Lp(a)] and proprotein convertase subtilisin/kexin type 9 (PCSK9) concentrations, and their complex, in patients with potential familial hypercholesterolemia (FH), depending on apo(a) phenotype. METHODS The study included 205 patients with total cholesterol (TC) > 7.5 mmol/L and/or low density lipoprotein cholesterol (LDL-C)>4.9 mmol/L, 32 (15%) patients suffered from ischemic heart disease (IHD), 64 were taking statins. The diagnosis of FH was estimated according to the Dutch Lipid Clinics Network criteria. Lipid parameters, apoB-containing lipoprotein subfractions, Lp(a), PCSK9, Lp(a)-PCSK9 complex levels and apo(a) phenotype were determined. Depending on the apo(a) phenotype, all patients were divided into 2 groups: with high molecular weight (HMW) (n = 145) and low molecular weight (LMW) (n = 60) apo(a) phenotype. RESULTS The groups were comparable by all major clinical characteristics and biochemical parameters. In the whole group, PCSK9 concentration correlated with age, statins intake, Lp(a), TC and TG levels. Correlation between Lp(a) and PCSK9 levels was found only in the LMW apo(a) phenotype group independently of statins intake (r = 0.46, p < 0.001). Associations between Lp(a)-PCSK9 complex and large subfractions of intermediate (r = 0.30) and low-density lipoproteins (r = 0.30, p < 0.05 for both) were observed, with more significance in group 2 (r = 0.59, p < 0.005 and r = 0.40, p < 0.05, respectively). CONCLUSIONS In patients with potential familial hypercholesterolemia, positive correlations between concentrations of Lp(a) and PCSK9, as well as of Lp(a)-PCSK9 plasma complex with large subfractions of intermediate and low-density lipoproteins (IDL-1 and LDL-C), were determined by the LMW apo(a) phenotype.
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22
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Paquette M, Bernard S, Thanassoulis G, Baass A. LPA genotype is associated with premature cardiovascular disease in familial hypercholesterolemia. J Clin Lipidol 2019; 13:627-633.e1. [DOI: 10.1016/j.jacl.2019.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 03/20/2019] [Accepted: 04/16/2019] [Indexed: 12/30/2022]
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23
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Rawther T, Tabet F. Biology, pathophysiology and current therapies that affect lipoprotein (a) levels. J Mol Cell Cardiol 2019; 131:1-11. [DOI: 10.1016/j.yjmcc.2019.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/22/2019] [Accepted: 04/09/2019] [Indexed: 12/11/2022]
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24
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Ma L, Waldmann E, Ooi EMM, Chan DC, Barrett HPR, Watts GF, Parhofer KG. Lipoprotein (a) and Low-density lipoprotein apolipoprotein B metabolism following apheresis in patients with elevated lipoprotein(a) and coronary artery disease. Eur J Clin Invest 2019; 49:e13053. [PMID: 30447089 DOI: 10.1111/eci.13053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/04/2018] [Accepted: 11/13/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Lipoprotein apheresis effectively lowers lipoprotein(a) [Lp(a)] and low-density lipoprotein (LDL) by approximately 60%-70%. The rebound of LDL and Lp(a) particle concentrations following lipoprotein apheresis allows the determination of fractional catabolic rate (FCR) and hence production rate (PR) during non-steady state conditions. We aimed to investigate the kinetics of Lp(a) and LDL apolipoprotein B-100 (apoB) particles in patients with elevated Lp(a) and coronary artery disease undergoing regular apheresis. PATIENTS AND METHODS A cross-sectional study was carried out in 13 patients with elevated Lp(a) concentration (>500 mg/L) and coronary artery disease. Lp(a) and LDL-apoB metabolic parameters, including FCR and PR were derived by the fit of a compartment model to the Lp(a) and LDL-apoB concentration data following lipoprotein apheresis. RESULTS The FCR of Lp(a) was significantly lower than that of LDL-apoB (0.39 [0.31, 0.49] vs 0.57 [0.46, 0.71] pools/day, P = 0.03) with no significant differences in the corresponding PR (14.80 [11.34, 19.32] vs 15.73 [11.93, 20.75] mg/kg/day, P = 0.80). No significant associations were observed between the FCR and PR of Lp(a) and LDL-apoB. CONCLUSIONS In patients with elevated Lp(a), the fractional catabolism of Lp(a) is slower than that of LDL-apoB particles, implying that different metabolic pathways are involved in the catabolism of these lipoproteins. These findings have implications for new therapies for lowering apolipoprotein(a) and apoB to prevent atherosclerotic cardiovascular disease.
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Affiliation(s)
- Louis Ma
- School of Biomedical Science, University of Western Australia, Western Australia, Australia.,School of Medicine, University of Western Australia, Western Australia, Australia
| | - Elisa Waldmann
- Department of Internal Medicine IV, Ludwig-Maximilans-University Munich, Munich, Germany
| | - Esther M M Ooi
- School of Biomedical Science, University of Western Australia, Western Australia, Australia
| | - Dick C Chan
- School of Biomedical Science, University of Western Australia, Western Australia, Australia.,School of Medicine, University of Western Australia, Western Australia, Australia
| | - Hugh P R Barrett
- School of Biomedical Science, University of Western Australia, Western Australia, Australia
| | - Gerald F Watts
- School of Medicine, University of Western Australia, Western Australia, Australia.,Department of Cardiology, Lipid Disorders Clinic, Royal Perth Hospital, Western Australia, Australia
| | - Klaus G Parhofer
- Department of Internal Medicine IV, Ludwig-Maximilans-University Munich, Munich, Germany
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25
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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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26
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Abstract
PURPOSE OF REVIEW Our primary objective is to review the most recent findings on the biology of PCSK9 and on two key aspects of PCSK9 inhibition beyond LDL control of great clinical relevance: the regulation of lipoprotein (a) circulating levels by PCSK9 inhibitors and the putative diabetogenic effects of these novel therapies. RECENT FINDINGS The reality of two distinct extracellular and intracellular pathways by which PCSK9 decreases the abundance of the LDLR at the surface of many cell types, most importantly hepatocytes, has recently been established. In contrast, the exact mechanisms by which PCSK9 inhibitors lower the circulating levels of lipoprotein (a) remain a point of major dispute. Despite strong indications from genetic studies that PCSK9 inhibition should increase diabetes risk, no such effect has been observed in clinical trials, and in-vitro and in-vivo studies do not clarify this issue. SUMMARY The trafficking pathways by which PCSK9 enhance LDLR degradation via the endolysosomal extracellular route or via the Golgi-lysosomal intracellular route remain to be fully elucidated. The mechanisms by which PCSK9 inhibitors reduce lipoprotein (a) also merit additional research efforts. The role of PCSK9 on glucose metabolism should likewise be studied in depth.
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27
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Abstract
Clinical trials have unequivocally shown that inhibition of proprotein convertase subtilisin/kexin type 9 (PCSK9) efficaciously and safely prevents cardiovascular events by lowering levels of LDL cholesterol. PCSK9 in the circulation is derived mainly from the liver, but the protein is also expressed in the pancreas, the kidney, the intestine and the central nervous system. Although PCSK9 modulates cholesterol metabolism by regulating LDL receptor expression in the liver, in vitro and in vivo studies have suggested that PCSK9 is involved in various other physiological processes. Although therapeutic PCSK9 inhibition could theoretically have undesired effects by interfering with these non-cholesterol-related processes, studies of individuals with genetically determined reduced PCSK9 function and clinical trials of PCSK9 inhibitors have not revealed clinically meaningful adverse consequences of almost completely eradicating PCSK9 from the circulation. The clinical implications of PCSK9 functions beyond lipid metabolism in terms of wanted or unwanted effects of therapeutic PCSK9 inhibition therefore appear to be limited. The objective of this Review is to describe the physiological role of PCSK9 beyond the LDL receptor to provide a rational basis for monitoring the effects of PCSK9 inhibition as these drugs gain traction in the clinic.
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Affiliation(s)
| | - Gilles Lambert
- Inserm UMR 1188 DéTROI, Université de La Réunion, Saint-Denis de La Réunion, France
| | - Bertrand Cariou
- L'institut du thorax, INSERM, CNRS, Université de Nantes, CHU Nantes, Nantes, France
| | - G Kees Hovingh
- Department of Vascular Medicine, Academisch Medisch Centrum, Amsterdam, Netherlands.
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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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29
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Bhatnagar D, Shiraz A. Modulation of cardiovascular risk factors. Curr Opin Lipidol 2018; 29:269-270. [PMID: 29715242 DOI: 10.1097/mol.0000000000000516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Deepak Bhatnagar
- Diabetes Centre, Royal Oldham Hospital, Oldham
- Division of Diabetes, Endocrinology & Gastroenterology, Univesrity of Manchester, Manchester
- University of Salford, Salford, UK
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PCSK9 inhibition with alirocumab reduces lipoprotein(a) levels in nonhuman primates by lowering apolipoprotein(a) production rate. Clin Sci (Lond) 2018; 132:1075-1083. [DOI: 10.1042/cs20180040] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 04/12/2018] [Accepted: 05/03/2018] [Indexed: 12/24/2022]
Abstract
Therapeutic antibodies targeting proprotein convertase subtilisin kexin type 9 (PCSK9) (e.g. alirocumab) lower low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in clinical trials. We recently showed that PCSK9 enhances apolipoprotein(a) [apo(a)] secretion from primary human hepatocytes but does not affect Lp(a) cellular uptake. Here, we aimed to determine how PCSK9 neutralization modulates Lp(a) levels in vivo.
Six nonhuman primates (NHP) were treated with alirocumab or a control antibody (IgG1) in a crossover protocol. After the lowering of lipids reached steady state, NHP received an intravenous injection of [2H3]-leucine, and blood samples were collected sequentially over 48 h. Enrichment of apolipoproteins in [2H3]-leucine was assessed by liquid chromatography–tandem mass spectrometry (LC–MS/MS). Kinetic parameters were calculated using numerical models with the SAAMII software. Compared with IgG1, alirocumab significantly reduced total cholesterol (TC) (−28%), LDL-C (−67%), Lp(a) (−56%), apolipoprotein B100 (apoB100) (−53%), and apo(a) (−53%). Alirocumab significantly increased the fractional catabolic rate of apoB100 (+29%) but not that of apo(a). Conversely, alirocumab sharply and significantly reduced the production rate (PR) of apo(a) (−42%), but not significantly that of apoB100, compared with IgG1, respectively.
In line with the observations made in human hepatocytes, the present kinetic study establishes that PCSK9 neutralization with alirocumab efficiently reduces circulating apoB100 and apo(a) levels by distinct mechanisms: apoB primarily by enhancing its catabolism and apo(a) primarily by lowering its production.
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Seidah NG, Chrétien M, Mbikay M. The ever-expanding saga of the proprotein convertases and their roles in body homeostasis: emphasis on novel proprotein convertase subtilisin kexin number 9 functions and regulation. Curr Opin Lipidol 2018; 29:144-150. [PMID: 29342010 DOI: 10.1097/mol.0000000000000484] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE OF REVIEW The nine members of the proprotein convertase family play major physiological roles during development and in the adult, and their dysregulation leads to various diseases. The primary objective of this article is to review recent findings on the clinical importance of some of these convertases concentrating mostly on PCSK9, the ninth member of the convertase family. This includes the transcriptional and translational regulation of PCSK9, its ability to enhance the degradation of LDL receptor (LDLR), and the implication of PCSK9 in inflammation and sepsis. RECENT FINDINGS PCSK9 levels are upregulated by E2F1 and reduced by specific miRNAs and by Annexin A2 that bind the 3' end of its mRNA. The implication of the LDLR in the clearance of pathogenic bacterial debris in mice and human puts in perspective a new role for PCSK9 in the regulation of sepsis. The specific implication of the LDLR in the clearance of Lp(a) is now confirmed by multiple studies of PCSK9 inhibition in human cohorts. SUMMARY Emerging data suggest that PCSK9 can be regulated at the transcriptional and translational levels by specific factors and miRNAs. The identification of a novel pocket in the catalytic domain of PCSK9 represents a harbinger for a new class of small inhibitor drugs. The implication of the LDLR in reducing the effects of bacterially induced sepsis has been supported by both human and mouse data. Outcome studies confirmed the clinical importance of reducing PCSK9 levels. The present review puts in perspective new developments in the PCSK9 biology and its regulation of the LDLR. VIDEO ABSTRACT: http://links.lww.com/COL/A17.
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Affiliation(s)
| | - Michel Chrétien
- Laboratory of Functional Endoproteolysis, Montreal Clinical Research Institute of Montreal (IRCM), Montreal, Quebec, Canada
| | - Majambu Mbikay
- Laboratory of Functional Endoproteolysis, Montreal Clinical Research Institute of Montreal (IRCM), Montreal, Quebec, Canada
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32
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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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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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34
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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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