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Candidate gene and pathway analyses identifying genetic variations associated with prasugrel pharmacokinetics and pharmacodynamics. Thromb Res 2018; 173:27-34. [PMID: 30458339 DOI: 10.1016/j.thromres.2018.11.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/16/2018] [Accepted: 11/14/2018] [Indexed: 01/29/2023]
Abstract
AIM We aimed to investigate the genetic polymorphisms and pharmacogenetic variability associated with the pharmacodynamics (PD) and pharmacokinetics (PK) of prasugrel, in healthy Han Chinese subjects. PATIENTS & METHODS Healthy, native, Han Chinese subjects (n = 36) aged 18 to 45 years with unknown genotypes were included. All subjects received a loading dose (LD) on day 1 and a maintenance dose (MD) from day 2 until day 11. Candidate gene association and gene-set analysis of biological pathways related to prasugrel and platelet activity were analyzed. RESULTS 28 SNPs of 17 candidate genes previously associated with prasugrel or platelet activity were selected after a literature search. In the 30 mg LD groups (n = 24), ITGA2-rs28095 was found to be significantly associated with the P2Y12 reaction unit (PRU) value at 24 h after the LD (p = 0.015). 165 study genes related to platelet activation-related processes and prasugrel activity were selected from the MSigDB database, including curated gene sets from KEGG, Bio Carta, and Gene Cards. 14 SNPs of 9 genes were found to be significantly correlated both at 24 h and 12 days after LD: ADAMTSL1, PRKCA, ITPR2, P2RY12, P2RY14, PLCB4, PRKG1, ADCY1, and LYN. Seven SNPs of 6 protein-coding genes associated with area under the concentration-time curve (AUC0-tlast) were significantly identified among the 47 selected genes, including ADAMTSL1, CD36, P2RY1, PCSK9, PON1, and SCD. CONCLUSION These results show that genetic variation affects the PK and PD of prasugrel in normal individuals. Further studies with larger sample sizes are required to explore whether the SNPs are associated only with prasugrel activity or also with cardiovascular events and all-cause mortality.
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Sokol J, Skerenova M, Ivankova J, Simurda T, Stasko J. Association of Genetic Variability in Selected Genes in Patients With Deep Vein Thrombosis and Platelet Hyperaggregability. Clin Appl Thromb Hemost 2018; 24:1027-1032. [PMID: 29865896 PMCID: PMC6714740 DOI: 10.1177/1076029618779136] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The aim of this study was to evaluate the genetic variability of the selected single nucleotide polymorphisms (SNPs) and examine the association between these SNPs and risk for deep vein thrombosis (DVT) in patients with sticky platelet syndrome (SPS). We examined 84 patients with SPS and history of DVT and 101 healthy individuals. We were interested in 2 SNPs within platelet endothelial aggregation receptor 1 (PEAR1) gene (rs12041331 and rs12566888), 2 SNPs within mkurine retrovirus integration site 1 gene (rs7940646 and rs1874445), 1 SNP within Janus kinase 2 gene (rs2230722), 1 SNP within FCER1G gene (rs3557), 1 SNP within pro-platelet basic protein (rs442155), 4 SNPs within alpha2A adrenergic receptor 2A (ADRA2A; rs1800545, rs4311994, rs11195419, and rs553668), and 1 SNP within sonic hedgehog gene (rs2363910). We identified 2 protective SNPs within PEAR1 gene and 1 risk SNP within ADRA2A gene (PEAR1: rs12041331 and rs12566888; ADRA2A: rs1800545). A haplotype analysis of 4 SNPs within ADRA2A gene identified a risk haplotype aagc ( P = .003). Moreover, we identified 1 protective haplotype within PEAR1 gene (AT, P = .004). Our results support the idea that genetic variability of PEAR1 and ADRA2A genes is associated with platelet hyperaggregability manifested as venous thromboembolism. The study also suggests a possible polygenic type of SPS heredity.
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Affiliation(s)
- Juraj Sokol
- 1 Department of Haematology and Transfusion Medicine, National Center of Haemostasis and Thrombosis, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Kollarova, Martin, Slovakia
| | - Maria Skerenova
- 2 Department of Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Kollarova, Martin, Slovakia
| | - Jela Ivankova
- 1 Department of Haematology and Transfusion Medicine, National Center of Haemostasis and Thrombosis, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Kollarova, Martin, Slovakia
| | - Tomas Simurda
- 1 Department of Haematology and Transfusion Medicine, National Center of Haemostasis and Thrombosis, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Kollarova, Martin, Slovakia
| | - Jan Stasko
- 1 Department of Haematology and Transfusion Medicine, National Center of Haemostasis and Thrombosis, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Kollarova, Martin, Slovakia
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3
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Abstract
Taken together, there is ample evidence of the association of cardiovascular disease, cerebrovascular, and inflammatory disease with single nucleotide variants (SNV) due to their impact on platelet size, number, and function. With the use of electronic medical record (EMR) or other phenotypic-linked bioinformatics sources, the more important "functional" variants are emerging and provide valuable information on their specific role in promoting early onset of disease or poor response to therapeutic measures. This review will focus upon the recognized common polymorphisms or gene variants with small, but functional effects, as it is becoming clear that these contribute to hyper- or hypo-responsive platelet phenotypes. The impact of these gene variants is distinguishable among normal individuals, and they are suspected contributors to increased risk of adverse outcomes in patients with underlying disease. There are thousands of gene variants and environmental factors that may mitigate risk or amplify the potential for disease within each of us. When combined with the environment and epigenetic influences, it is clear that whole-genome sequencing and bioinformatics alone will not be enough to truly predict "risk" or probability, but awareness of their potential influence may be a starting point in selective screening and generating prevention strategies to promote a healthy lifestyle or fine-tune therapeutic choices in the future.
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Affiliation(s)
- Diane Nugent
- a Hematology Advanced Diagnostic Laboratory , CHOC Children's Hospital , Orange , CA , USA.,b Center for Inherited Blood Disorders , Orange , CA.,c UC Irvine Medical School , Irvine , CA , USA
| | - Thomas Kunicki
- a Hematology Advanced Diagnostic Laboratory , CHOC Children's Hospital , Orange , CA , USA.,b Center for Inherited Blood Disorders , Orange , CA.,c UC Irvine Medical School , Irvine , CA , USA
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Adefurin A, Vanderbilt C, Okafor C, Kawai V, Li C, Shah A, Wei WQ, Kurnik D, Stein CM. Alpha2A adrenergic receptor genetic variation contributes to hyperglycemia after myocardial infarction. Int J Cardiol 2016; 215:482-6. [PMID: 27131769 PMCID: PMC4879094 DOI: 10.1016/j.ijcard.2016.04.079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/11/2016] [Indexed: 01/04/2023]
Abstract
BACKGROUND Acute myocardial infarction (AMI) is frequently associated with transient hyperglycemia even in patients without pre-existing diabetes. Acute stress can lead to increased blood glucose through the effect of catecholamines on alpha2A-adrenergic receptors (α2A-ARs) present in pancreatic islet β-cells. Variation in the gene (ADRA2A) that encodes the α2A-AR affects insulin release and glucose control and may play a particularly important role during times of stress. METHODS We performed a retrospective cohort study using de-identified electronic medical records linked to a DNA repository in 521 Caucasians and 55 African-American non-diabetic patients with AMI. We examined the association between admission blood glucose concentrations and ten selected ADRA2A SNPs in Caucasians. RESULTS Three ADRA2A SNPS were associated with stress-induced hyperglycemia in Caucasians. Individuals homozygous for the rs10885122 variant (n=9) had a 23% lower admission glucose (geometric mean [95% CI], 99 [83-118]mg/dl) compared with non-carriers (121 [118-125] mg/dl; n=401; P=0.001). Admission glucose was 14% higher in rs1800544 variant homozygotes (134 [119-150]mg/dl; n=36) compared to non-carriers (118 [115-121]mg/dl; n=290, P=0.046). Furthermore, homozygotes of the rs553668 variant (n=13) had a 13% higher glucose (133 [110-160]mg/dl) compared to non-carriers (118 [115-122]mg/dl; n=366; P=0.056). Haplotypes including these ADRA2A SNPs were associated with higher admission glucose levels. CONCLUSIONS Three ADRA2A genetic variants are associated with blood glucose and stress-induced hyperglycemia after AMI in Caucasians.
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Affiliation(s)
- Abiodun Adefurin
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Charles Vanderbilt
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Chimalum Okafor
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Vivian Kawai
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Chun Li
- Department of Epidemiology and Biostatistics, Institute for Computational Biology, Case Western Reserve University, Cleveland, OH, United States
| | - Anushi Shah
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA
| | - Wei-Qi Wei
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, USA
| | - Daniel Kurnik
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA; Clinical Pharmacology Unit, Rambam Medical Center, Haifa, Israel; Rappaport Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, Israel.
| | - C Michael Stein
- Departments of Medicine and Pharmacology, Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Nashville, TN, USA
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Postula M, Janicki PK, Eyileten C, Rosiak M, Kaplon-Cieslicka A, Sugino S, Wilimski R, Kosior DA, Opolski G, Filipiak KJ, Mirowska-Guzel D. Next-generation re-sequencing of genes involved in increased platelet reactivity in diabetic patients on acetylsalicylic acid. Platelets 2015; 27:357-64. [PMID: 26599574 DOI: 10.3109/09537104.2015.1109071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The objective of this study was to investigate whether rare missense genetic variants in several genes related to platelet functions and acetylsalicylic acid (ASA) response are associated with the platelet reactivity in patients with diabetes type 2 (T2D) on ASA therapy. Fifty eight exons and corresponding introns of eight selected genes, including PTGS1, PTGS2, TXBAS1, PTGIS, ADRA2A, ADRA2B, TXBA2R, and P2RY1 were re-sequenced in 230 DNA samples from T2D patients by using a pooled PCR amplification and next-generation sequencing by Illumina HiSeq2000. The observed non-synonymous variants were confirmed by individual genotyping of 384 DNA samples comprising of the individuals from the original discovery pools and additional verification cohort of 154 ASA-treated T2DM patients. The association between investigated phenotypes (ASA induced changes in platelets reactivity by PFA-100, VerifyNow and serum thromboxane B2 level [sTxB2]), and accumulation of rare missense variants (genetic burden) in investigated genes was tested using statistical collapsing tests. We identified a total of 35 exonic variants, including 3 common missense variants, 15 rare missense variants, and 17 synonymous variants in 8 investigated genes. The rare missense variants exhibited statistically significant difference in the accumulation pattern between a group of patients with increased and normal platelet reactivity based on PFA-100 assay. Our study suggests that genetic burden of the rare functional variants in eight genes may contribute to differences in the platelet reactivity measured with the PFA-100 assay in the T2DM patients treated with ASA.
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Affiliation(s)
- Marek Postula
- a Department of Experimental and Clinical Pharmacology , Medical University of Warsaw, Center for Preclinical Research and Technology CEPT , Warsaw , Poland.,b Perioperative Genomics Laboratory , Penn State College of Medicine , Hershey , PA , USA
| | - Piotr K Janicki
- b Perioperative Genomics Laboratory , Penn State College of Medicine , Hershey , PA , USA
| | - Ceren Eyileten
- a Department of Experimental and Clinical Pharmacology , Medical University of Warsaw, Center for Preclinical Research and Technology CEPT , Warsaw , Poland
| | - Marek Rosiak
- a Department of Experimental and Clinical Pharmacology , Medical University of Warsaw, Center for Preclinical Research and Technology CEPT , Warsaw , Poland.,c Department of Cardiology and Hypertension , Central Clinical Hospital, The Ministry of the Interior , Warsaw , Poland
| | | | - Shigekazu Sugino
- b Perioperative Genomics Laboratory , Penn State College of Medicine , Hershey , PA , USA
| | - Radosław Wilimski
- e Department of Cardiac Surgery , Medical University of Warsaw , Warsaw , Poland
| | - Dariusz A Kosior
- c Department of Cardiology and Hypertension , Central Clinical Hospital, The Ministry of the Interior , Warsaw , Poland.,f Department of Applied Physiology , Mossakowski Medical Research Centre, Polish Academy of Sciences , Warsaw , Poland
| | - Grzegorz Opolski
- d Department of Cardiology , Medical University of Warsaw , Warsaw , Poland
| | | | - Dagmara Mirowska-Guzel
- a Department of Experimental and Clinical Pharmacology , Medical University of Warsaw, Center for Preclinical Research and Technology CEPT , Warsaw , Poland
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Mlakar V, Jurkovic Mlakar S, Zupan J, Komadina R, Prezelj J, Marc J. ADRA2A is involved in neuro-endocrine regulation of bone resorption. J Cell Mol Med 2015; 19:1520-9. [PMID: 25818344 PMCID: PMC4511350 DOI: 10.1111/jcmm.12505] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 10/28/2014] [Indexed: 12/12/2022] Open
Abstract
Adrenergic stimulation is important for osteoclast differentiation and bone resorption. Previous research shows that this happens through β2-adrenergic receptor (AR), but there are conflicting evidence on presence and role of α2A-AR in bone. The aim of this study was to investigate the presence of α2A-AR and its involvement in neuro-endocrine signalling of bone remodelling in humans. Real-time polymerase chain reaction (PCR) and immunohistochemistry were used to investigate α2A-AR receptor presence and localization in bone cells. Functionality of rs553668 and rs1800544 single nucleotide polymorphism SNPs located in α2A-AR gene was analysed by qPCR expression on bone samples and luciferase reporter assay in human osteosarcoma HOS cells. Using real-time PCR, genetic association study between rs553668 A>G and rs1800544 C>G SNPs and major bone markers was performed on 661 Slovenian patients with osteoporosis. α2A-AR is expressed in osteoblasts and lining cells but not in osteocytes. SNP rs553668 has a significant influence on α2A-AR mRNA level in human bone samples through the stability of mRNA. α2A-AR gene locus associates with important bone remodelling markers (BMD, CTX, Cathepsin K and pOC). The results of this study are providing comprehensive new evidence that α2A-AR is involved in neuro-endocrine signalling of bone turnover and development of osteoporosis. As shown by our results the neurological signalling is mediated through osteoblasts and result in bone resorption. Genetic study showed association of SNPs in α2A-AR gene locus with bone remodelling markers, identifying the individuals with higher risk of development of osteoporosis.
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Affiliation(s)
- Vid Mlakar
- Department of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Simona Jurkovic Mlakar
- Department of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Janja Zupan
- Department of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | - Radko Komadina
- Department for Research and Education, General and Teaching Hospital Celje, Celje, Slovenia
| | - Janez Prezelj
- Department of Endocrinology, Diabetes and Metabolic Diseases, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Janja Marc
- Department of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
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Geisler T, Schaeffeler E, Gawaz M, Schwab M. Genetic variation of platelet function and pharmacology: an update of current knowledge. Thromb Haemost 2013; 110:876-87. [PMID: 23702580 DOI: 10.1160/th13-02-0145] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 04/25/2013] [Indexed: 11/05/2022]
Abstract
Platelets are critically involved in atherosclerosis and acute thrombosis. The platelet phenotype shows a wide variability documented by the inherited difference of platelet reactivity, platelet volume and count and function of platelet surface receptors. Several candidate genes have been put into focus and investigated for their functional and prognostic role in healthy individuals and patients with cardiovascular (CV) disease treated with antiplatelet agents. In addition to genetic variation, other clinical, disease-related and demographic factors are important so-called non-genetic factors. Due to the small effect sizes of single nucleotide polymorphisms (SNP) in candidate genes and due to the low allele frequencies of functional relevant candidate SNPs, the identification of genetic risk factors with high predictive values generally depends on the sample size of study cohorts. In the post-genome era new array and bioinformatic technologies facilitate high throughput genome-wide association studies (GWAS) for the identification of novel candidate genes in large cardiovascular cohorts. One of the crucial aspects of platelet genomic studies is the precise definition of a specific clinical phenotype (e.g. stent thrombosis) as this will impact importantly the findings of genomic studies like GWAS. Here, we provide an update on genetic variation of platelet receptors and drug metabolising enzymes under specific consideration of data derived by GWAS. The potential impact of this information and the role in personalised therapeutic concepts will be discussed.
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Affiliation(s)
- T Geisler
- Tobias Geisler, Medizinische Klinik, Innere Medizin III, Kardiologie und Kreislauferkrankungen, Otfried-Müller-Str. 10, 72076 Tübingen, Germany, Tel: +49 7071 29 83688, E-mail:
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8
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Abstract
PURPOSE OF REVIEW This review summarizes our current knowledge of common gene variants (polymorphisms) that have small individual effects on platelet function in humans, but can cumulatively lead to hyperreactive platelets and increase risk for negative outcomes in thrombotic disorders. RECENT FINDINGS Candidate gene association and genome-wide association studies (GWAS) have identified loci that include single nucleotide polymorphisms, which exert a cumulative effect on platelet function by modifying basic platelet parameters, such as mean platelet volume (MPV) or platelet count, by altering the expression or activity of key platelet receptors, or by influencing downstream effector pathways utilized by these receptors. SUMMARY Variation in MPV between normal individuals is responsible for roughly a two-fold range in platelet protein content, including key surface receptors and reactive granule constituents, the association of ADRA2, GP1BA, GP6, ITGA2 and P2Y12 variants with platelet reactivity, initially identified by candidate gene analyses, has now been validated by genome-wide approaches in much larger individual cohorts, and GWAS have identified novel gene variants, most notably PEAR1, that participate in variation in platelet reactivity among normal individuals, all of which contribute to a genetic basis for differences in platelet reactivty among normal individuals.
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Postula M, Kaplon-Cieslicka A, Rosiak M, Kondracka A, Serafin A, Filipiak KJ, Czlonkowski A, Opolski G, Janicki PK. Genetic determinants of platelet reactivity during acetylsalicylic acid therapy in diabetic patients: evaluation of 27 polymorphisms within candidate genes. J Thromb Haemost 2011; 9:2291-301. [PMID: 21854539 DOI: 10.1111/j.1538-7836.2011.04482.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Decreased platelet responsiveness to acetylsalicylic acid (ASA) reported previously in diabetic patients could be attributed to patient-based, clinical, genetic and cellular factors. The objective of the present study was to investigate the effect of the genomic polymorphism on the platelet reactivity in diabetic patients treated with ASA. METHODS AND RESULTS The study cohort consisted of 295 Caucasians with diabetes type 2 who had been taking ASA tablets at the dose of 75 mg per day for at least 3 months for primary or secondary prevention of myocardial infarction (MI). Platelet reactivity analyzes were performed using VerifyNow ASA and PFA-100 assays. Genotyping for the selected 27 single nucleotide polymorphisms (SNPs) within 19 genes was performed using a Sequenom iPLEX platform. The results indicate that the statistically significant differences in platelet reactivity were observed in the PFA-100 assay for SNPs in following genes: TXBA2R (rs1131882), ADRA2A (rs4311994), PLA2G7 (rs7756935) and 9p21.3 (rs10120688) (P = 0.02, P = 0.03, P = 0.02, P = 0.03, respectively, all significance levels corrected for multiple comparisons). When using the VerifyNow ASA test, a weak nominal statistical significance (i.e. before multiple comparison testing) was observed for two SNPs in the GPVI gene: rs1671152 and rs1613662 [P = 0.025 (0.5) for both SNPs, corrected for multiple comparisons test]. CONCLUSIONS The results from the present study suggest that the four analyzed genes may contribute to platelet reactivity measured with the PFA-100 assay in the diabetic population treated with ASA.
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Affiliation(s)
- M Postula
- Department of Cardiology, Medical University of Warsaw, Poland.
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10
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Johnson AD. The genetics of common variation affecting platelet development, function and pharmaceutical targeting. J Thromb Haemost 2011; 9 Suppl 1:246-57. [PMID: 21781261 PMCID: PMC3151008 DOI: 10.1111/j.1538-7836.2011.04359.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Common variant effects on human platelet function and response to anti-platelet treatment have traditionally been studied using candidate gene approaches involving a limited number of variants and genes. These studies have often been undertaken in clinically defined cohorts. More recently, studies have applied genome-wide scans in larger population samples than prior candidate studies, in some cases scanning relatively healthy individuals. These studies demonstrate synergy with some prior candidate gene findings (e.g., GP6, ADRA2A) but also uncover novel loci involved in platelet function. Here, I summarise findings on common genetic variation influencing platelet development, function and therapeutics. Taken together, candidate gene and genome-wide studies begin to account for common variation in platelet function and provide information that may ultimately be useful in pharmacogenetic applications in the clinic. More than 50 loci have been identified with consistent associations with platelet phenotypes in ≥ 2 populations. Several variants are under further study in clinical trials relating to anti-platelet therapies. In order to have useful clinical applications, variants must have large effects on a modifiable outcome. Regardless of clinical applications, studies of common genetic influences, even of small effect, offer additional insights into platelet biology including the importance of intracellular signalling and novel receptors. Understanding of common platelet-related genetics remains behind parallel fields (e.g., lipids, blood pressure) due to challenges in phenotype ascertainment. Further work is necessary to discover and characterise loci for platelet function, and to assess whether these loci contribute to disease aetiologies or response to therapeutics.
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Affiliation(s)
- A D Johnson
- National Heart, Lung and Blood Institute's The Framingham Heart Study, Framingham, MA 01702, USA.
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11
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Kameda S, Sakata T, Kokubo Y, Mitsuguro M, Okamoto A, Sano M, Miyata T. Association of platelet aggregation with lipid levels in the Japanese population: the Suita study. J Atheroscler Thromb 2011; 18:560-7. [PMID: 21427509 DOI: 10.5551/jat.6288] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
AIM Platelets play a pivotal role in atherothrombotic diseases. Platelet aggregability induced by agonists has great interindividual variability; however, the factors influencing platelet aggregability variation have not been characterized in Asia. METHODS To examine the confounding factors influencing platelet counts and responsiveness to agonists, we measured the platelet counts and platelet aggregability induced by 1.7 µM adenosine diphosphate (ADP) or 1.7 µg/mL collagen using a light transmittance aggregometer in the Japanese general population without medication or cardiovascular disease (387 men and 550 women) in the Suita Study. RESULTS Platelet counts were negatively correlated with age in both men and women (Spearman's rank correlation coefficient: r(s)=-0.230 and -0.227; p< 0.01, respectively). In women, platelet counts were correlated negatively with the high-density lipoprotein (HDL) cholesterol level and positively with the low-density lipoprotein (LDL) cholesterol/HDL cholesterol (L/H) ratio (r(s)=-0.135 and 0.119; p< 0.01, respectively). In women, platelet aggregabilities by ADP and collagen were correlated with age (r(s)=0.118 and 0.143; p< 0.01, respectively), and collagen-induced platelet aggregability was correlated with the LDL cholesterol level, the L/H ratio, and the non-HDL cholesterol level (r(s)=0.167, 0.172, and 0.185; p< 0.01, respectively). Even after adjustment for age, systolic blood pressure, body mass index, and current smoking and drinking, the association of platelet counts with the L/H ratio in women and associations of collagen-induced platelet aggregability with the L/H ratio and the non-HDL cholesterol level remained. CONCLUSION Examination of platelet counts and platelet aggregability induced by ADP and collagen revealed gender, age and lipid levels as factors influencing inter-individual variability.
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Affiliation(s)
- Sachika Kameda
- Laboratory of Clinical Chemistry, National Cerebral and Cardiovascular Center, Fujishiro-dai, Suita, Osaka, Japan.
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12
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Abstract
Genetic and environmental factors contribute to a substantial variation in platelet function seen among normal persons. Candidate gene association studies represent a valiant effort to define the genetic component in an era where genetic tools were limited, but the single nucleotide polymorphisms identified in those studies need to be validated by more objective, comprehensive approaches, such as genome-wide association studies (GWASs) of quantitative functional traits in much larger cohorts of more carefully selected normal subjects. During the past year, platelet count and mean platelet volume, which indirectly affect platelet function, were the subjects of GWAS. The majority of the GWAS signals were located to noncoding regions, a consistent outcome of all GWAS to date, suggesting a major role for mechanisms that alter phenotype at the level of transcription or posttranscriptional modifications. Of 15 quantitative trait loci associated with mean platelet volume and platelet count, one located at 12q24 is also a risk locus for coronary artery disease. In most cases, the effect sizes of individual quantitative trait loci are admittedly small, but the results of these studies have led to new insight into regulators of hematopoiesis and megakaryopoiesis that would otherwise be unapparent and difficult to define.
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13
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Johnson AD, Yanek LR, Chen MH, Faraday N, Larson MG, Tofler G, Lin SJ, Kraja AT, Province MA, Yang Q, Becker DM, O'Donnell CJ, Becker LC. Genome-wide meta-analyses identifies seven loci associated with platelet aggregation in response to agonists. Nat Genet 2010; 42:608-13. [PMID: 20526338 PMCID: PMC3057573 DOI: 10.1038/ng.604] [Citation(s) in RCA: 206] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 05/12/2010] [Indexed: 12/26/2022]
Abstract
Platelet function mediates both beneficial and harmful effects on human health, but few genes are known to contribute to variability in this process. We tested association of 2.5 million SNPs with platelet aggregation responses to three agonists (ADP, epinephrine and collagen) in two cohorts of European ancestry (N
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Affiliation(s)
- Andrew D Johnson
- National Heart, Lung, and Blood Institute's The Framingham Heart Study, Framingham, Massachusetts, USA.
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A functional genomics approach reveals novel quantitative trait loci associated with platelet signaling pathways. Blood 2009; 114:1405-16. [PMID: 19429868 DOI: 10.1182/blood-2009-02-202614] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Platelet response to activation varies widely between individuals but shows interindividual consistency and strong heritability. The genetic basis of this variation has not been properly explored. We therefore systematically measured the effect on function of sequence variation in 97 candidate genes in the collagen and adenosine-diphosphate (ADP) signaling pathways. Resequencing of the genes in 48 European DNA samples nearly doubled the number of known single nucleotide polymorphisms (SNPs) and informed the selection of 1327 SNPs for genotyping in 500 healthy Northern European subjects with known platelet responses to collagen-related peptide (CRP-XL) and ADP. This identified 17 novel associations with platelet function (P < .005) accounting for approximately 46% of the variation in response. Further investigations with platelets of known genotype explored the mechanisms behind some of the associations. SNPs in PEAR1 associated with increased platelet response to CRP-XL and increased PEAR1 protein expression after platelet degranulation. The minor allele of a 3' untranslated region (UTR) SNP (rs2769668) in VAV3 was associated with higher protein expression (P = .03) and increased P-selectin exposure after ADP activation (P = .004). Furthermore the minor allele of the intronic SNP rs17786144 in ITPR1 modified Ca(2+) levels after activation with ADP (P < .004). These data provide novel insights into key hubs within platelet signaling networks.
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Martínez C, Antón AI, Corral J, Quiroga T, Panes O, Lozano ML, González-Conejero R, Teruel R, Navarro-Núñez L, Pereira J, Mezzano D, Vicente V, Rivera J. Genotype-phenotype relationship for six common polymorphisms in genes affecting platelet function from 286 healthy subjects and 160 patients with mucocutaneous bleeding of unknown cause. Br J Haematol 2009; 146:95-103. [PMID: 19388931 DOI: 10.1111/j.1365-2141.2009.07713.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Polymorphisms affecting platelet receptors and intracellular proteins have been extensively studied in relation to their potential influence in thrombosis and haemorrhages. However, few reports have addressed their impact on platelet function, with contradictory results. Limitations of these studies include, among others, small number of patients, the platelet functional parameters analyzed and their known variability in the healthy population. We studied the effect of six polymorphisms [ITGB3 1565T > C (HPA-1), GPIBA variable number tandem repeat and 524C > T (HPA-2), ITGA2 807C > T, ADRA2A 1780A > G, and TUBB1 Q43P] on platelet function in 286 healthy subjects and their potential pathogenetic role in 160 patients with hereditary mucocutaneous bleeding of unknown cause. We found no effect of any of these polymorphisms on platelet aggregation, secretion, PFA-100, and thrombin generation in platelet rich plasma. Furthermore, patients and controls showed no significant differences in the frequency of any of these polymorphisms. Thus, our study demonstrated that polymorphisms in genes affecting platelet function do not influence significantly major platelet functions and appear irrelevant in the pathogenesis of bleeding disorders.
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Rivera J, Lozano ML, Navarro-Núñez L, Vicente V. Platelet receptors and signaling in the dynamics of thrombus formation. Haematologica 2009; 94:700-11. [PMID: 19286885 DOI: 10.3324/haematol.2008.003178] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hemostasis and pathological thrombus formation are dynamic processes that require a co-ordinated series of events involving platelet membrane receptors, bidirectional intracellular signals, and release of platelet proteins and inflammatory substances. This review aims to summarize current knowledge in the key steps in the dynamics of thrombus formation, with special emphasis on the crucial participation of platelet receptors and signaling in this process. Initial tethering and firm adhesion of platelets to the exposed subendothelium is mediated by glycoprotein (GP) Ib/IX/V complex and collagen receptors, GP VI and alpha(2)beta(1) integrin, in the platelet surface, and by VWF and fibrillar collagen in the vascular site. Interactions between these elements are largely influenced by flow and trigger signaling events that reinforce adhesion and promote platelet activation. Thereafter, soluble agonists, ADP, thrombin, TxA(2), produced/released at the site of vascular injury act in autocrine and paracrine mode to amplify platelet activation and to recruit circulating platelets to the developing thrombus. Specific interactions of these agonists with their G-protein coupled receptors generate inside-out signaling leading to conformational activation of integrins, in particular alpha(IIb)beta(3), increasing their ligand affinity. Binding of alpha(IIb)beta(3) to its ligands, mainly fibrinogen, supports processes such as clot retraction and platelet aggregation. Stabilization of thrombi is supported by the late wave of signaling events promoted by close contact between aggregated platelets. The best known contact-dependent signaling is outside-in signaling through alphaIb beta(3), but new ones are being clarified such as those mediated by interaction of Eph receptors with ephrins, or by Sema 4D and Gas-6 binding to their receptors. Finally, newly identified mechanisms appear to control thrombus growth, including back-shifting of activated integrins and actuation of compensatory molecules such as ESAM or PECAM-1. The expanding knowledge of thrombotic disease is expected to translate into the development of new drugs to help management and prevention of thrombosis.
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Affiliation(s)
- José Rivera
- Centro Regional de Hemodonación, Universidad de Murcia, C/ Ronda de Garay s/n., Murcia, Spain
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Alpha 2A adrenergic receptor polymorphism is associated with plasma von Willebrand factor levels in a general population. Blood Coagul Fibrinolysis 2008; 19:395-9. [DOI: 10.1097/mbc.0b013e3283001d38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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