Effect of common single nucleotide polymorphisms in COX-1 gene on related metabolic activity in diabetic patients treated with acetylsalicylic acid.

Clinical Basic research research Effect of common single nucleotide polymorphisms COX-1 gene gene on on related related metabolic metabolic activity activity in in diabetic diabetic in COX-1 patients treated with acetylsalicylic acid 1,2 1,2 Marek Postula Postula1,2 , Piotr K. Janicki3, Marek Rosiak1,2 , Agnieszka Kaplon-Cieslicka Kaplon-Cieslicka44,, Agnieszka AgnieszkaKondracka Kondracka5,5, 4 1,6 4 44 1,6 2 2 4 4 Filipiak ,, Dariusz Dariusz A. A.Kosior Kosior , Andrzej , AndrzejCzlonkowski Czlonkowski, Grzegorz , GrzegorzOpolski Opolski Ewa Trzepla , Krzysztof J. Filipiak 1Department of Cardiology and Hypertension, Central Clinical Hospital, the Ministry of the Interior, Warsaw, Poland 2Department of Clinical and Experimental Pharmacology, Medical University of Warsaw, Warsaw, Poland 3Perioperative Genomics Laboratory, Department of Anesthesiology, Penn State College of Medicine, Hershey, Pennsylvania, USA 4Department of Cardiology, Medical University of Warsaw, Warsaw, Poland 5Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Warsaw, Poland 6Mossakowski Medical Research Centre Polish Academy of Sciences, Warsaw, Poland Submitted: 25 February 2012 Accepted: 10 April 2012 Arch Med Sci 2014; 10, 6: 1198–1205 DOI: 10.5114/aoms.2013.35442 Copyright © 2014 Termedia & Banach Abstract Introduction: The objective of this study was to investigate the effect of common single nucleotide genomic polymorphisms in the cyclooxygenase-1 (COX-1) gene on the thromboxane A2 (TxA2) metabolite concentrations in serum and urine, as well as on prostaglandin F2α (PGF2α) urinary excretion in the diabetic population on acetylsalicylic acid (ASA) therapy. Material and methods: The study cohort consisted of 284 Caucasians with diabetes type 2 who had been taking ASA tablets at the dose of 75 mg/day for at least 3 months. Genotyping for the 4 selected SNPs within the COX-1 gene (two nonsynonymous-coding variants, rs3842787 [C50T, P17L] and rs5789 [C174A, L237M]; and two other synonymous SNPs, rs3842788 [G128A, Q41Q] and rs5788 [C644A]) was performed using the Sequenom iPLEX platform. Results: No statistically significant results were observed for the investigated SNPs and measured metabolites in the investigated cohort of patients. Statistically significant differences in S-TxB2 could however be observed for rs5788 in the subgroup of patients with very high S-TxB2 concentrations. In particular, more patients who were carriers of the minor allele for this polymorphism were observed in the group with S-TxB2 levels > 95th percentile, when compared with similar carriers in the group with S-TxB2 < 95th percentile (20% vs. 1.1%, respectively, p < 0.001, Mann-Whitney test). Conclusions: The results of our study suggest that the four investigated common SNPs in the COX1 gene are not associated with obviously altered TxA 2 metabolism and PGF2α synthesis in the investigated diabetic cohort treated with ASA. Key words: acetylsalicylic acid, cyclooxygenase-1, diabetes mellitus, thromboxane, 8-iso-prostaglandin F2α. Introduction Several mechanisms caused by metabolic and cellular abnormalities have been suggested to play a role in increased platelet reactivity. Endogenous Corresponding author: Marek Rosiak Department of Cardiology Medical University of Warsaw 1 A Banacha St 02-097 Warsaw, Poland Phone: +48 22 599 19 58 Fax: +48 22 599 19 57 E-mail: Effect of common single nucleotide polymorphisms in COX-1 gene on related metabolic activity in diabetic patients treated with acetylsalicylic acid and environmental factors – age, cholesterol and inflammatory markers levels, hypertension, diabetes mellitus, and cigarette smoking – explain only part of the variation in platelet function observed in persons with these conditions [1–9]. Although inherited and genetic factors have known links to cardiovascular disease, the evidence for genetic influences that enhance platelet function is much weaker [10–12]. Patients with type 2 diabetes mellitus (T2DM) are characterized by an elevated risk of recurrent atherothrombotic events. In addition, acetylsalicylic acid (ASA) therapy may be less effective in high-risk populations [11, 13, 14]. Patients with T2DM exhibit platelet hyperreactivity both in vitro and in vivo coupled with biochemical evidence of persistently increased thromboxane-dependent platelet activation [3–6]. Furthermore, polymorphisms in different genes have been associated with variability for increased platelet reactivity on ASA therapy in T2DM patients [14–16]. The problems with determining ASA response and the different methodologies available for determining the biochemical and functional effects of ASA have compounded the problems of attempting to define increased platelet reactivity despite ASA therapy, with some investigators suggesting that the term should be used only when production of thromboxane A2 (TxA2) (or its breakdown products) is blocked regardless of platelet function [11, 17]. Acetylsalicylic acid irreversibly inhibits cyclooxygenase (COX)-1 in human platelets. COX-1 (prostaglandin endoperoxide G/H synthase) catalyzes the formation of prostaglandin H2 (PGH2) from arachidonic acid (AA). This action is the committed step in prostaglandin synthesis, which yields the bioactive eicosanoids, prostaglandin D2, prostaglandin F2α (PGF2α), prostaglandin I2, and TxA2 through branching enzymatic pathways (Figure 1) [18]. The effect of ASA repeatedly administered once daily is irreversible, cumulative and saturable, reaching a ceiling effect in the low dose range [19]. The TxA2 production can be determined by measuring stable metabolites of TxA2, such as thromboxane B2 (TxB2) in the serum and 11-dehydro-TxB2 (11-dh-TxB2) in the urine. Because serum TxB2 production is predominantly dependent on platelet COX-1, it has been used as a primary measure of the inhibitory effects of low-dose ASA on platelets [20]. In addition to TxA2, platelets release F2-isoprostanes, in particular 8-iso-prostaglandin F2α (8-iso-PGF2α), a chemically stable compound derived from enzymatic and nonenzymatic oxidation of AA [21]. Platelet 8-iso-PGF2α is synthesized in vivo as a minor product of the COX-1 enzyme in human platelets and the COX-2 isoform in human monocytes, as well as through the free radical-catalyzed peroxidation of AA in biological membranes [22, 23]. Because 8-iso-PGF2α formation might correlate with the rate of TxA2 biosynthesis, it was hypothesized that increased oxidant stress in T2DM could induce enhanced generation of 8-iso-PGF2α, which can contribute to platelet activation [24]. Even if it was demonstrated previously that enhanced 8-isoPGF2α synthesis may be associated with advanced age, cigarette smoking, hypercholesterolemia, and unstable angina, as well as after coronary artery reperfusion, the role of 8-iso-PGF2α in ASA’s effect on TxA2 synthesis remains uncertain [25–33]. Genetic variation in COX-1 may affect enzyme expression, biochemical function or int (...truncated)