Abstract-Interleukin-6 (IL-6) synthesized in response to diverse stimuli may play an important role in bridging the inflammatory and atherosclerotic processes. The acute-phase response after coronary artery bypass graft surgery (CABG) is associated with the induction and release of cytokines, such as IL-6. We have examined the effect of common polymorphisms in the IL-6 gene promoter (Ϫ174GϾC, Ϫ572GϾC, and Ϫ597GϾA) on IL-6 levels after elective CABG. DNA extracted from the peripheral blood of 127 patients was amplified by polymerase chain reaction. IL-6 genotypes were resolved by gel electrophoresis after restriction enzyme digestion. Serum IL-6 was measured before surgery and in serial samples at 6, 24, 48, and 72 hours after CABG. Genotype distribution was as expected for a population in Hardy-Weinberg equilibrium for all polymorphisms. Rare allele frequencies (Ϯ95% CIs) were similar to those reported previously: Ϫ597A 0.36 (0.30 to 0.42), Ϫ572C 0.07 (0.04 to 0.10), and Ϫ174C 0.37 (0.31 to 0.43). The Ϫ174GϾC and Ϫ597GϾA genotypes were in strong allelic association (⌬ϭ0.97, PϽ0.001). Baseline IL-6 levels did not significantly differ between patients with different genotypes for any polymorphism. However, 6 hours after CABG, peak IL-6 levels were significantly higher (Pϭ0.03) in carriers of the Ϫ572C allele than in those of the Ϫ572GG genotype (355Ϯ67 versus 216Ϯ13 pg/mL, respectively) and in those with genotype Ϫ174CC compared with Ϫ174G allele carriers (287Ϯ31 versus 227Ϯ15 pg/mL, respectively; Pϭ0.04). These effects remained statistically significant after adjusting for possible confounders, including age, sex, smoking, duration of cardiopulmonary bypass, aortic cross-clamp time, and total duration of surgery. These data demonstrate that IL-6 promoter polymorphisms influence peak IL-6 production after CABG, suggesting that these polymorphisms, which are functional in vitro, are also functional in vivo, suggesting a genetic influence on IL-6 levels after acute severe injury. (Arterioscler Thromb Vasc

Objective-Cyclooxygenase (COX)-2 is a key regulatory enzyme in the synthesis of prostanoids associated with trauma and inflammation. We investigated the COX-2 gene for functional variants that may influence susceptibility to disease. Methods and Results-The promoter of COX-2 was screened for variants in healthy subjects by use of polymerase chain reaction-based methods. Promoter activity was investigated by using reporter expression experiments in human lung fibroblasts. Patients undergoing coronary artery bypass graft surgery, with measurements of plasma markers linked to COX-2 activity, were genotyped for association studies. A common COX-2 promoter variant, Ϫ765GϾC, was found and shown to be carried by Ͼ25% of a group of healthy UK subjects. The Ϫ765C allele had significantly lower promoter activity compared with Ϫ765G, basally (28Ϯ3% lower, PϽ0.005) and in serum-stimulated cells (31Ϯ2% lower, PϽ0.005). In patients subjected to coronary artery bypass graft surgery, the magnitude of rise in levels of C-reactive protein (CRP) was strongly genotype dependent. Compared with Ϫ765G homozygotes, patients carrying the Ϫ765C allele had significantly lower plasma CRP levels at 1 to 4 days after surgery (14% lower at the peak of CRP levels on day 3, PϽ0.05 for all time points). Key Words: cyclooxygenase-2 Ⅲ promoter variant Ⅲ coronary artery bypass graft surgery Ⅲ C-reactive protein Ⅲ inflammation C yclooxygenase (COX) is a key regulatory enzyme in eicosanoid metabolism, converting free arachidonic acid to prostaglandin (PG)H 2 , from which a number of prostanoids, including PGE 2 , PGI 2 , PGD 2 , and thromboxane, are produced. 1 The prostanoids are important mediators in the control of normal tissue homeostasis and regulate inflammation in response to trauma or infection. 2 Two isoforms of COX have been identified, COX-1 and COX-2, which have common and specific roles. 3 COX-1 is expressed constitutively in most cell types; however, COX-2 is inducible on cell activation and is mainly expressed at sites of inflammation. COX-2 expression is raised in several pathophysiological states, and the use of COX inhibitors to reduce COX-2 activity has proven beneficial in attenuating chronic inflammatory conditions, such as arthritis and inflammatory bowel disease. 4,5 Several million people worldwide regularly use COX inhibitors. Regular use has been shown to decrease the relative risk of developing cardiovascular disease, stroke, and colorectal cancer. 5,6 See page 1516 Conclusions-ForAlthough COX-2 is widely accepted as a proinflammatory agonist and is therefore a suitable target for treating chronic inflammatory disease, there is increasing evidence to suggest that COX-2 has other roles, including anti-inflammatory, antifibrotic, and antithrombotic properties. 7-9 These alternative roles challenge the dogma that COX-2 is ubiquitously a foe, and indeed, there is evidence indicating that with certain tissue injuries, a limited expression of COX-2 can result in pathology, as in pulmonary fibrosis. 8,10 It also appears that COX-...

Background-Abdominal aortic aneurysm is a multifactorial disorder in which inflammation is an important pathophysiological feature. In explant culture, aneurysm biopsies secrete large amounts of interleukin-6 (IL-6), and among aneurysm patients, the circulating concentration of IL-6 appears to be increased. Methods and Results-We investigated, in 19 patients, whether aneurysm wall was an important source of circulating IL-6.We also tested the hypotheses, in 466 patients with a small aneurysm, that (1) high concentrations of circulating IL-6 signaled rapid aneurysm growth and (2) the Ϫ174 G3 C polymorphism in the IL-6 promoter predicted survival. For 19 patients with large or inflammatory aneurysms, the concentration of IL-6 was higher in the iliac arteries than the brachial arteries (median difference 26.5 pg/mL, this difference increasing with aneurysm diameter, Pϭ0.01). In 466 patients with small aneurysms, the frequency of the Ϫ174 C allele (0.40) was similar to that in a normal healthy population. Patients of GG genotype had lower plasma concentrations of IL-6 than patients of GC and CC genotypes (medians 1.9, 4.8, and 15.6 pg/mL, respectively, Kruskal-Wallis Pϭ0.047). Cardiovascular and all-cause mortalities were lower for patients of GG genotype than for patients of GC and CC genotype: hazard ratios 0.32 (95% CI 0.12 to 0.93), Pϭ0.036, and 0.51 (95% CI 0.25 to 1.00), Pϭ0.05, respectively. There was no association between plasma IL-6 or IL-6 genotype and aneurysm growth. Conclusions-Aortic aneurysms appear to be an important source of circulating IL-6, the concentration being influenced by genotype. For patients with small aneurysms, the Ϫ174 G3 C IL-6 genotype predicts future cardiovascular mortality.

A polymorphism of the human angiotensin-1-converting enzyme (ACE) gene has been identified in which the presence (insertion, I allele) of a 287-bp fragment rather than the absence (deletion, D allele) is associated with lower ACE activity. Several recent studies have shown an association of the I allele with endurance performance, it being found with excess frequency in elite distance runners, rowers and mountaineers. Other workers using heterogeneous cohorts of athletes from mixed sporting disciplines have found no such association. An increasing linear trend of I allele frequency with the distance run amongst Olympic runners and an excess of the D allele amongst sprinters led us to examine whether the ratio of I and D alleles in swimmers competing over different distances would also vary. Swimmers (n=120) from the European and Commonwealth championships and an American college team had their ACE genotype determined and their gene and allele frequencies compared with several control groups, the most closely age-matched of which were 1,248 military recruits. Of the 103 Caucasians, there was a significant excess of the D allele compared with this control group only in the truly elite swimmers of the European and Commonwealth championships (P=0.004). This association remained in those competing over shorter distances (P=0.005 for 400 m and below) but not in the longer events. These findings were confirmed in three further large control groups. A population association study testing whether a genetic marker (the ACE I/D polymorphism) occurs more frequently in cases (elite athletes) than in controls therefore requires a homogeneous cohort of subjects from the same sporting discipline.

Emotional trauma and psychological stress can precipitate cardiac arrhythmia and sudden death through arrhythmogenic effects of efferent sympathetic drive. Patients with preexisting heart disease are particularly at risk. Moreover, generation of proarrhythmic activity patterns within cerebral autonomic centers may be amplified by afferent feedback from a dysfunctional myocardium. An electrocortical potential reflecting afferent cardiac information has been described, reflecting individual differences in interoceptive sensitivity (awareness of one's own heartbeats). To inform our understanding of mechanisms underlying arrhythmogenesis, we extended this approach, identifying electrocortical potentials corresponding to the cortical expression of afferent information about the integrity of myocardial function during stress. We measured changes in cardiac response simultaneously with electroencephalography in patients with established ventricular dysfunction. Experimentally induced mental stress enhanced cardiovascular indices of sympathetic activity (systolic blood pressure, heart rate, ventricular ejection fraction, and skin conductance) across all patients. However, the functional response of the myocardium varied; some patients increased, whereas others decreased, cardiac output during stress. Across patients, heartbeat-evoked potential amplitude at left temporal and lateral frontal electrode locations correlated with stress-induced changes in cardiac output, consistent with an afferent cortical representation of myocardial function during stress. Moreover, the amplitude of the heartbeat-evoked potential in the left temporal region reflected the proarrhythmic status of the heart (inhomogeneity of left ventricular repolarization). These observations delineate a cortical representation of cardiac function predictive of proarrhythmic abnormalities in cardiac repolarization. Our findings highlight the dynamic interaction of heart and brain in stress-induced cardiovascular morbidity. afferent homeostatic feedback ͉ electroencephalography ͉ heart beat-evoked potential ͉ insula cortex ͉ ischemia

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Objective-C-reactive protein (CRP) concentrations are predictive of cardiovascular disease, and levels are heritable, in part. We identified novel polymorphisms in the CRP gene and assessed their influence on CRP level. Methods and Results-CRP was measured in 250 male army recruits before and after strenuous exercise and perioperatively in 193 coronary artery bypass graft (CABG) patients. Two novel polymorphisms were identified in the CRP gene, Ϫ717GϾA in the promoter and ϩ1444CϾT in the 3ЈUTR. Among army recruits, CRP was higher in ϩ1444TT homozygotes than ϩ1444 C-allele carriers at baseline (

Background: Interleukin-6 (IL-6) concentrations vary substantially among individuals. This study aimed to identify novel genetic markers to explain these differences. Methods: We sequenced a region 6-kb upstream of the IL6 [interleukin 6 (interferon, beta 2)] transcription start site in a search for functional variants and detected 3 common variants: −6331T>C, −6101A>T, and −5617/−5616C/A>T/G. IL6 −6331T>C (C allele frequency, 0.20; 95% confidence interval, 0.16–0.24) showed strong negative linkage disequilibrium with −174G>C (D′ = −0.97) and was studied further in 309 individuals who underwent coronary artery bypass grafting. Results: Patients with the TT genotype had higher IL-6 concentrations 6 h after surgery than those with the CC genotype (mean, 199.4 ng/L vs 114.9 ng/L; P = 0.02). A similar association was seen in a cohort of 173 patients who underwent intensive periodontal therapy: Individuals with the CC genotype had significantly lower IL-6 concentrations 24 h after therapy than TT patients (mean, 0.78 ng/L vs 5.00 ng/L; P < 0.0001). A similar trend was observed in 203 healthy individuals from northern Europe (1.29 ng/L for the TT genotype vs 0.89 ng/L for the CC genotype; P = 0.07). Reporter assays that used a sequence flanking the −6331 single-nucleotide polymorphism spliced upstream to the IL-6 minimal promoter driving luciferase gene expression demonstrated a 1.3-fold increase in promoter activity (P < 0.01) for constructs containing −6331T. Electrophoretic mobility shift assays revealed enhanced binding of transcription factor Oct-1 to the T allele. Conclusions: IL6 −6331T is associated with increased IL-6 concentrations in an acute inflammatory state via a mechanism involving binding of the Oct-1 transcription factor. This finding may help resolve conflicting studies based on the IL6 −174G>C variant.