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Brosolo G, Da Porto A, Marcante S, Picci A, Capilupi F, Capilupi P, Bulfone L, Vacca A, Bertin N, Vivarelli C, Comand J, Catena C, Sechi LA. Lipoprotein(a): Just an Innocent Bystander in Arterial Hypertension? Int J Mol Sci 2023; 24:13363. [PMID: 37686169 PMCID: PMC10487946 DOI: 10.3390/ijms241713363] [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: 08/07/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
Elevated plasma lipoprotein(a) [Lp(a)] is a relatively common and highly heritable trait conferring individuals time-dependent risk of developing atherosclerotic cardiovascular disease (CVD). Following its first description, Lp(a) triggered enormous scientific interest in the late 1980s, subsequently dampened in the mid-1990s by controversial findings of some prospective studies. It was only in the last decade that a large body of evidence has provided strong arguments for a causal and independent association between elevated Lp(a) levels and CVD, causing renewed interest in this lipoprotein as an emerging risk factor with a likely contribution to cardiovascular residual risk. Accordingly, the 2022 consensus statement of the European Atherosclerosis Society has suggested inclusion of Lp(a) measurement in global risk estimation. The development of highly effective Lp(a)-lowering drugs (e.g., antisense oligonucleotides and small interfering RNA, both blocking LPA gene expression) which are still under assessment in phase 3 trials, will provide a unique opportunity to reduce "residual cardiovascular risk" in high-risk populations, including patients with arterial hypertension. The current evidence in support of a specific role of Lp(a) in hypertension is somehow controversial and this narrative review aims to overview the general mechanisms relating Lp(a) to blood pressure regulation and hypertension-related cardiovascular and renal damage.
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Affiliation(s)
- Gabriele Brosolo
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Andrea Da Porto
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- Diabetes and Metabolism Unit, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Stefano Marcante
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Alessandro Picci
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Filippo Capilupi
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Patrizio Capilupi
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Luca Bulfone
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Antonio Vacca
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Nicole Bertin
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- Thrombosis and Hemostasis Unit, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Cinzia Vivarelli
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
| | - Jacopo Comand
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Cristiana Catena
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
| | - Leonardo A. Sechi
- Department of Medicine, University of Udine, 33100 Udine, Italy; (A.D.P.); (S.M.); (A.P.); (F.C.); (P.C.); (L.B.); (A.V.); (N.B.); (C.V.); (J.C.); (C.C.)
- European Hypertension Excellence Center, Clinica Medica, University of Udine, 33100 Udine, Italy
- Diabetes and Metabolism Unit, Clinica Medica, University of Udine, 33100 Udine, Italy
- Thrombosis and Hemostasis Unit, Clinica Medica, University of Udine, 33100 Udine, Italy
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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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Lipoprotein(a) beyond the kringle IV repeat polymorphism: The complexity of genetic variation in the LPA gene. Atherosclerosis 2022; 349:17-35. [PMID: 35606073 PMCID: PMC7613587 DOI: 10.1016/j.atherosclerosis.2022.04.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 02/23/2022] [Accepted: 04/01/2022] [Indexed: 12/24/2022]
Abstract
High lipoprotein(a) [Lp(a)] concentrations are one of the most important genetically determined risk factors for cardiovascular disease. Lp(a) concentrations are an enigmatic trait largely controlled by one single gene (LPA) that contains a complex interplay of several genetic elements with many surprising effects discussed in this review. A hypervariable coding copy number variation (the kringle IV type-2 repeat, KIV-2) generates >40 apolipoprotein(a) protein isoforms and determines the median Lp(a) concentrations. Carriers of small isoforms with up to 22 kringle IV domains have median Lp(a) concentrations up to 5 times higher than those with large isoforms (>22 kringle IV domains). The effect of the apo(a) isoforms are, however, modified by many functional single nucleotide polymorphisms (SNPs) distributed over the complete range of allele frequencies (<0.1% to >20%) with very pronounced effects on Lp(a) concentrations. A complex interaction is present between the apo (a) isoforms and LPA SNPs, with isoforms partially masking the effect of functional SNPs and, vice versa, SNPs lowering the Lp(a) concentrations of affected isoforms. This picture is further complicated by SNP-SNP interactions, a poorly understood role of other polymorphisms such as short tandem repeats and linkage structures that are poorly captured by common R2 values. A further layer of complexity derives from recent findings that several functional SNPs are located in the KIV-2 repeat and are thus not accessible to conventional sequencing and genotyping technologies. A critical impact of the ancestry on correlation structures and baseline Lp(a) values becomes increasingly evident. This review provides a comprehensive overview on the complex genetic architecture of the Lp(a) concentrations in plasma, a field that has made tremendous progress with the introduction of new technologies. Understanding the genetics of Lp(a) might be a key to many mysteries of Lp(a) and booster new ideas on the metabolism of Lp(a) and possible interventional targets.
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Ma X, Liu Y, Tan Y, Qu K, He X, Zhang H, Wang Z. Diallyl disulphide inhibits apolipoprotein(a) expression in HepG2 cells through the MEK1-ERK1/2-ELK-1 pathway. Lipids Health Dis 2017; 16:223. [PMID: 29178936 PMCID: PMC5702159 DOI: 10.1186/s12944-017-0616-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/16/2017] [Indexed: 11/24/2022] Open
Abstract
Background Lipoprotein(a) [LP(a)] is implicated as a common and independent risk factor for cardiovascular diseases. The therapeutic options currently available for reducing plasma LP(a) concentrations are limited. Diallyl disulphide (DADS), the main component of garlic, regulates lipid metabolism in hepatocytes and adipocytes through ERK1/2 signalling. This study aimed to assess the effect of DADS on apolipoprotein(a) [apo(a)] in HepG2 cells. We also determined the effects of DADS on apo(a) expression and secretion in HepG2 cells as well as the underlying mechanisms. Methods We examined the role of DADS on apo(a) expression in HepG2 cells by treating cell with different concentrations of DADS (10, 20, 40 and 80 μg/mL) for 24 h or treating cells with 40 μg/mL DADS for 0, 6, 12, 24 and 48 h. Then we used quantitative real-time PCR to analysis apo(a) mRNA levels, used Western blot to analysis apo(a) protein levels and used enzyme-linked immunosorbent assay to test apo(a) secreted levels. To farther determined the role of DADS, we applied Transfection of small interfering RNA to knockdown ELK-1levels and applied PD98059, a specific inhibitor of ERK1/2, to block ERK1/2 signal. Results The results show DADS inhibited apo(a) at both the mRNA and protein levels in HepG2 cells in a dose-dependent manner. DADS-mediated inhibition of apoa(a) expression in HepG2 cells was attenuated when the cells were cultured in medium containing PD98059 (ERK1/2 inhibitor) or were transfected with siRNAs against MEK1 or ELK-1. Overexpression of apo(a) yielded similar results. Conclusions This study reveals that DADS can downregulate apo(a) expression in a dose-dependent manner via the MEK-ERK12-ELK-1 pathway.
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Affiliation(s)
- Xiaofeng Ma
- Department of Cardiology, Affiliated Nanhua Hospital of University of South China, Hengyang, 421001, China.,Institute of Cardiovascular disease, Key Laboratory for Atherosclerology of Human Province, University of South China, Hengyang, 421001, China
| | - Yami Liu
- Institute of Cardiovascular disease, Key Laboratory for Atherosclerology of Human Province, University of South China, Hengyang, 421001, China
| | - Yanmei Tan
- Department of Pathology, Changde Vocational Technical College, Changde, 415000, China
| | - Kai Qu
- Institute of Cardiovascular disease, Key Laboratory for Atherosclerology of Human Province, University of South China, Hengyang, 421001, China
| | - Xinglan He
- Women and Children Healthcare Hospital of Zhu zhou, Zhuzhou, 412000, China
| | - Hai Zhang
- Department of Pathology, The First Affiliated Hospital of University of South China, Hengyang, 421001, China.
| | - Zuo Wang
- Institute of Cardiovascular disease, Key Laboratory for Atherosclerology of Human Province, University of South China, Hengyang, 421001, China.
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Zeng JF, Zeng ZL, Zhang K, Zhao Y, Liu YM, Chen JJ, Tong H, Wei DH, Jiang ZS, Wang Z. miR-23b-3p and miR-125b-5p downregulate apo(a) expression by targeting Ets1 in HepG2 cells. Cell Biol Int 2017; 42:313-323. [PMID: 29064597 DOI: 10.1002/cbin.10896] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 10/22/2017] [Indexed: 12/24/2022]
Abstract
High concentrations of plasma lipoprotein(a) [Lp(a)] have been inferred to be an independent risk factor for cardiovascular and cerebrovascular diseases, such as coronary artery diseases, restenosis, and stroke. Apolipoprotein(a) [apo(a)] is one of the most important components of Lp(a) and contributes greatly to the increased concentration of plasma Lp(a). As a critical positive transacting factor of apo(a) gene, Ets1 has been proven as a target gene of several miRNAs, such as miR-193b, miR-125b-5p, miR-200b, miR-1, and miR-499. In this study, a series of experiments on miRNAs and relative miRNAs inhibitor delivered HepG2 cells were conducted, and two miRNAs that downregulate the apo(a) by targeting the 3'-UTR of Ets1 were identified. Results showed that apo(a) and Ets1 were differentially expressed in SMMC7721 and HepG2 cell lines. Meanwhile, apo(a) and Ets1 were inversely correlated with several hepatic endogenous miRNAs, such as miR-125b-5p, miR-23b-3p, miR-26a-5p, and miR-423-5p, which were predicted to bind to Ets1. Results show that miR-125b-5p and miR-23b-3p mimics could inhibit the synthesis of apo(a) by directly targeting Ets1 in HepG2, thereby reducing the plasma Lp (a) concentration.
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Affiliation(s)
- Jun-Fa Zeng
- The Second Hospital Affiliated to University of South China, Hengyang, Hunan, 421001, PR China
| | - Zhao-Lin Zeng
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Kai Zhang
- The Second Hospital Affiliated to University of South China, Hengyang, Hunan, 421001, PR China
| | - Yue Zhao
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Ya-Mi Liu
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Jiao-Jiao Chen
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Hai Tong
- The First Hospital Affiliated to University of South China, Hengyang, Hunan, 421001, PR China
| | - Dang-Heng Wei
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Zhi-Sheng Jiang
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
| | - Zuo Wang
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan, 421001, PR China
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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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Qu K, Ma XF, Li GH, Zhang H, Liu YM, Zhang K, Zeng JF, Lei JJ, Wei DH, Wang Z. Vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells. Int J Biol Macromol 2017; 98:637-645. [PMID: 28192139 DOI: 10.1016/j.ijbiomac.2017.02.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 01/16/2017] [Accepted: 02/06/2017] [Indexed: 01/01/2023]
Abstract
Lipoprotein(a)[Lp(a)] is a risk factor for coronary heart diseases. However, the metabolism of this protein remains poorly understood. Efficient and specific drugs that can decrease high plasma levels of Lp(a) have not been developed yet. Vitamin C is responsible for maintaining the catalytic activity of a group of iron and 2-oxoglutarate (2OG)-dependent dioxygenases and induces the generation of 5-hydroxymethylcytosine (5hmC) via Ten-eleven translocation (Tet) dioxygenases. In addition, It has been reported vitamin C deficiency induces atherosclerosis and increases Lp(a) and apo(a) plasma levels in Lp(a)+ mice. However, the mechanism is still unclear. In this study, we investigated the effects of vitamin C on apo(a) expression and the possible molecular mechanism of vitamin C that influences apolipoprotein(a) [apo(a)] biosynthesis in HepG2 cells. Results showed that vitamin C significantly inhibited the expression and secretion levels of apo(a). Vitamin C can also increase ELK1 expression and hydroxymethylation of ELK1 promoter and the globle DNA in HepG2 cells. In addition, the effects of vitamin C inhibiting the apo(a) expression were attenuated by ELK1siRNA and Tet2siRNA. These results suggested vitamin C down-regulate apo(a) expression via Tet2-dependent DNA demethylation in HepG2 cells.
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Affiliation(s)
- Kai Qu
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Xiao-Feng Ma
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Guo-Hua Li
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Hai Zhang
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Ya-Mi Liu
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Kai Zhang
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China; The Second Hospital Affiliated to University of South China, Hengyang 421001, Hunan, China
| | - Jun-Fa Zeng
- The Second Hospital Affiliated to University of South China, Hengyang 421001, Hunan, China
| | - Jian-Jun Lei
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Dang-Heng Wei
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China
| | - Zuo Wang
- Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, University of South China, Hengyang, Hunan 421001 China.
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Hoover-Plow J, Huang M. Lipoprotein(a) metabolism: potential sites for therapeutic targets. Metabolism 2013; 62:479-91. [PMID: 23040268 PMCID: PMC3547132 DOI: 10.1016/j.metabol.2012.07.024] [Citation(s) in RCA: 112] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/03/2012] [Accepted: 07/11/2012] [Indexed: 11/20/2022]
Abstract
Lipoprotein(a) [Lp(a)] resembles low-density lipoprotein (LDL), with an LDL lipid core and apolipoprotein B (apoB), but contains a unique apolipoprotein, apo(a). Elevated Lp(a) is an independent risk factor for coronary and peripheral vascular diseases. The size and concentration of plasma Lp(a) are related to the synthetic rate, not the catabolic rate, and are highly variable with small isoforms associated with high concentrations and pathogenic risk. Apo(a) is synthesized in the liver, although assembly of apo(a) and LDL may occur in the hepatocytes or plasma. While the uptake and clearance site of Lp(a) is poorly delineated, the kidney is the site of apo(a) fragment excretion. The structure of apo(a) has high homology to plasminogen, the zymogen for plasmin and the primary clot lysis enzyme. Apo(a) interferes with plasminogen binding to C-terminal lysines of cell surface and extracellular matrix proteins. Lp(a) and apo(a) inhibit fibrinolysis and accumulate in the vascular wall in atherosclerotic lesions. The pathogenic role of Lp(a) is not known. Small isoforms and high concentrations of Lp(a) are found in healthy octogenarians that suggest Lp(a) may also have a physiological role. Studies of Lp(a) function have been limited since it is not found in commonly studied small mammals. An important aspect of Lp(a) metabolism is the modification of circulating Lp(a), which has the potential to alter the functions of Lp(a). There are no therapeutic drugs that selectively target elevated Lp(a), but a number of possible agents are being considered. Recently, new modifiers of apo(a) synthesis have been identified. This review reports the regulation of Lp(a) metabolism and potential sites for therapeutic targets.
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Affiliation(s)
- Jane Hoover-Plow
- J. J. Jacobs Center for Thrombosis and Vascular Biology, Department of Cardiovascular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44139, USA.
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Moradi Marjaneh M, Kirk EP, Posch MG, Ozcelik C, Berger F, Hetzer R, Otway R, Butler TL, Blue GM, Griffiths LR, Fatkin D, Martinson JJ, Winlaw DS, Feneley MP, Harvey RP. Investigation of association between PFO complicated by cryptogenic stroke and a common variant of the cardiac transcription factor GATA4. PLoS One 2011; 6:e20711. [PMID: 21673957 PMCID: PMC3108965 DOI: 10.1371/journal.pone.0020711] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2010] [Accepted: 05/08/2011] [Indexed: 01/12/2023] Open
Abstract
Patent foramen ovale (PFO) is associated with clinical conditions including cryptogenic stroke, migraine and varicose veins. Data from studies in humans and mouse suggest that PFO and the secundum form of atrial septal defect (ASDII) exist in an anatomical continuum of septal dysmorphogenesis with a common genetic basis. Mutations in multiple members of the evolutionarily conserved cardiac transcription factor network, including GATA4, cause or predispose to ASDII and PFO. Here, we assessed whether the most prevalent variant of the GATA4 gene, S377G, was significantly associated with PFO or ASD. Our analysis of world indigenous populations showed that GATA4 S377G was largely Caucasian-specific, and so subjects were restricted to those of Caucasian descent. To select for patients with larger PFO, we limited our analysis to those with cryptogenic stroke in which PFO was a subsequent finding. In an initial study of Australian subjects, we observed a weak association between GATA4 S377G and PFO/Stroke relative to Caucasian controls in whom ASD and PFO had been excluded (OR = 2.16; p = 0.02). However, in a follow up study of German Caucasians no association was found with either PFO or ASD. Analysis of combined Australian and German data confirmed the lack of a significant association. Thus, the common GATA4 variant S377G is likely to be relatively benign in terms of its participation in CHD and PFO/Stroke.
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Affiliation(s)
- Mahdi Moradi Marjaneh
- The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Kensington, Australia
| | - Edwin P. Kirk
- Faculty of Medicine, University of New South Wales, Kensington, Australia
- Department of Medical Genetics, Sydney Children's Hospital, Randwick, Australia
| | - Maximilian G. Posch
- The Experimental and Clinical Research Center (ECRC), Charité – Universitätsmedizin, Berlin, Germany
- Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Cemil Ozcelik
- The Experimental and Clinical Research Center (ECRC), Charité – Universitätsmedizin, Berlin, Germany
| | | | | | - Robyn Otway
- The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Tanya L. Butler
- Heart Centre for Children, The Children's Hospital at Westmead, Westmead, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Gillian M. Blue
- Heart Centre for Children, The Children's Hospital at Westmead, Westmead, Australia
| | - Lyn R. Griffiths
- Genomics Research Centre, Griffith University, Gold Coast, Australia
| | - Diane Fatkin
- The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Kensington, Australia
- Cardiology Department, St Vincent's Hospital, Darlinghurst, Australia
| | - Jeremy J. Martinson
- University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - David S. Winlaw
- Heart Centre for Children, The Children's Hospital at Westmead, Westmead, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Michael P. Feneley
- The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Kensington, Australia
- Cardiology Department, St Vincent's Hospital, Darlinghurst, Australia
| | - Richard P. Harvey
- The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Kensington, Australia
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Warnatz HJ, Querfurth R, Guerasimova A, Cheng X, Haas SA, Hufton AL, Manke T, Vanhecke D, Nietfeld W, Vingron M, Janitz M, Lehrach H, Yaspo ML. Functional analysis and identification of cis-regulatory elements of human chromosome 21 gene promoters. Nucleic Acids Res 2010; 38:6112-23. [PMID: 20494980 PMCID: PMC2952857 DOI: 10.1093/nar/gkq402] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Given the inherent limitations of in silico studies relying solely on DNA sequence analysis, the functional characterization of mammalian promoters and associated cis-regulatory elements requires experimental support, which demands cloning and analysis of putative promoter regions. Focusing on human chromosome 21, we cloned 182 gene promoters of 2500 bp in length and conducted reporter gene assays on transfected-cell arrays. We found 56 promoters that were active in HEK293 cells, while another 49 promoters could be activated by treatment of cells with Trichostatin A or depletion of serum. We observed high correlations between promoter activities and endogenous transcript levels, RNA polymerase II occupancy, CpG islands and core promoter elements. Truncation of a subset of 62 promoters to ∼500 bp revealed that truncation rarely resulted in loss of activity, but rather in loss of responses to external stimuli, suggesting the presence of cis-regulatory response elements within distal promoter regions. In these regions, we found a strong enrichment of transcription factor binding sites that could potentially activate gene expression in the presence of stimuli. This study illustrates the modular functional architecture of chromosome 21 promoters and helps to reveal the complex mechanisms governing transcriptional regulation.
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Affiliation(s)
- Hans-Jörg Warnatz
- Department for Vertebrate Genomics, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
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The apo(a) gene (TTTTA)n promoter polymorphism and its association with variability in exons of the kringle IV types 8 to 10. Clin Chim Acta 2009; 405:39-42. [DOI: 10.1016/j.cca.2009.03.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 03/30/2009] [Accepted: 03/30/2009] [Indexed: 11/22/2022]
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Zídková K, Kebrdlová V, Zlatohlávek L, Ceska R. Detection of variability in apo(a) gene transcription regulatory sequences using the DGGE method. Clin Chim Acta 2006; 376:77-81. [PMID: 16916503 DOI: 10.1016/j.cca.2006.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/17/2006] [Accepted: 07/17/2006] [Indexed: 11/27/2022]
Abstract
BACKGROUND Increased lipoprotein(a), Lp(a), concentration is an independent risk factor for premature atherosclerosis. Apolipoprotein(a), apo(a), determines properties of the lipoprotein and its production rate is the limiting step in Lp(a) particle formation. METHODS Subjects covering the whole range of Lp(a) concentration were separated into quintiles. A randomly chosen sample from each quintile was derived, there being a total number of 713 individuals. The DGGE method was used to scan the known transcription regulatory regions of apo(a) gene (promoter; DHII and DHIII enhancers) for variability and its distribution across quintiles. RESULTS Besides 5 previously reported nucleotide substitutions (+121 G>A; +93 C>T; -1712 G>T; -1617 C>A; -1230 A>G) 16 unreported rare sequence variants were detected. All polymorphic variants were distributed throughout the quintiles with several significant differences. The novel +62 C variant was found only among individuals with Lp(a) levels over 16 mg/dl. CONCLUSION The apo(a) gene transcription regulatory regions were not revealed to be extremely polymorphic. However, we should consider a combined effect of all polymorphic sites from the whole apo(a) gene locus, including the apo(a) gene length polymorphism, when dealing with high population variability of Lp(a) levels.
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Affiliation(s)
- Katerina Zídková
- 3rd Medical Department, 1st Faculty of Medicine and General Teaching Hospital, Charles University in Prague, Prague 12808, Czech Republic.
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