A Common Missense Variant in the ATP Receptor P2X7 Is Associated with Reduced Risk of Cardiovascular Events

BACKGROUND AND PURPOSE: Extracellular adenosine triphosphate (ATP) regulates inflammatory cells by activation of the P2X(7) receptor. We hypothesized that polymorphisms in P2RX7 influence the risk of ischemic heart disease (IHD), ischemic stroke (IS) and cardiovascular risk factors and tested this hypothesis using genetic association studies. METHODS: Two loss-of-function SNPs in P2RX7 were genotyped in 1244 IHD cases and 2488 controls as well as 5969 individuals with cardiovascular risk factors. Eleven SNPs in a 250 kb region on chromosome 12 spanning P2RX7 as well as neighboring genes OASL, P2RX4 and CAMKK2 were genotyped in 4138 individuals with IS and 2528 controls. Association was examined using linear and logistic regression models with an additive genetic model. RESULTS: The common loss-of-function variant rs3751143 was significantly associated with a decreased risk of IHD in smokers (P = 0.03) as well as decreased risk of IS (OR 0.89; 95% CI = 0.81-0.97; P = 0.012). In addition, an intronic SNP in CAMKK2, rs2686342, were associated with a decreased risk of IS (OR 0.89; 95% CI = 0.82-0.97; P = 0.011). In subgroup analyses, both SNPs were associated with decreased risk of IS in individuals with hypertension (P = 0.045 and 0.015, respectively). CONCLUSIONS: A common loss-of-function missense variant in the gene encoding the P2X(7) receptor is associated with reduced risk of IS and with IHD in smokers. These findings might implicate a role of purinergic signaling in atherogenesis or atherothrombosis

Collaboration between CpG sites is needed for stable somatic inheritance of DNA methylation states

Published online 27 November 2013Inheritance of 5-methyl cytosine modification of CpG (CG/CG) DNA sequences is needed to maintain early developmental decisions in vertebrates. The standard inheritance model treats CpGs as independent, with methylated CpGs maintained by efficient methylation of hemimethylated CpGs produced after DNA replication, and unmethylated CpGs maintained by an absence of de novo methylation. By stochastic simulations of CpG islands over multiple cell cycles and systematic sampling of reaction parameters, we show that the standard model is inconsistent with many experimental observations. In contrast, dynamic collaboration between CpGs can provide strong error-tolerant somatic inheritance of both hypermethylated and hypomethylated states of a cluster of CpGs, reproducing observed stable bimodal methylation patterns. Known recruitment of methylating enzymes by methylated CpGs could provide the necessary collaboration, but we predict that recruitment of demethylating enzymes by unmethylated CpGs strengthens inheritance and allows CpG islands to remain hypomethylated within a sea of hypermethylation.Jan O. Haerter, Cecilia Lövkvist, Ian B. Dodd and Kim Sneppe

Cognitive function in stroke survivors : A 10-year follow-up study

OBJECTIVES: Post-stroke cognitive impairment (PSCI) has considerable impact on patients and society. However, long-term studies on PSCI are scarce and may be influenced by assessment methods and selection bias. We aimed to (i) assess the prevalence of long-term PSCI; (ii) compare two common cognitive assessment instruments; and (iii) compare cognitive function of long-term stroke survivors with non-stroke persons.METHODS: Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were administered to 10-year survivors from a population-based cohort of first-ever stroke patients included in the Lund Stroke Register, Sweden, in 2001-2002. PSCI was defined as MMSE<27 and/or MoCA<25 and severe cognitive impairment as MMSE<23. Age- and sex-matched non-stroke control subjects who had performed MMSE (but not MoCA) were recruited from the longitudinal population study "Good Ageing in Skåne." The odds of having cognitive impairment for stroke survivors compared to controls were examined with logistic regression analyses adjusting for education.RESULTS: Of 145 stroke survivors after 10 years, 127 participated. MMSE showed PSCI in 46%, whereas MoCA displayed PSCI in 61%. Among the stroke survivors with MoCA<25, 35% had MMSE≥27 (P<.001). The odds of having severe cognitive impairment defined as MMSE<23 were higher among the stroke survivors compared to 354 controls (education-adjusted; OR=2.5; P=.004).CONCLUSIONS: Post-stroke cognitive impairment was prevalent among 10-year stroke survivors, and the odds of having severe cognitive impairment were higher among the stroke survivors compared to non-stroke persons. The burden of long-term PSCI might have been underestimated previously, and MoCA may be more suitable than MMSE to detect long-term PSCI

Data from: Variable effects on growth and defence traits for plant ecotypic differentiation and phenotypic plasticity along elevation gradients

Along ecological gradients, phenotypic differentiation can arise through natural selection on trait diversity and magnitude, and environment-driven plastic changes. The magnitude of ecotypic differentiation versus phenotypic plasticity can vary depending on the traits under study. Using reciprocal transplant-common gardens along steep elevation gradients, we evaluated patterns of ecotypic differentiation and phenotypic plasticity of several growth and defence-related traits for two coexisting but unrelated plant species, Cardamine pratensis and Plantago major. For both species, we observed ecotypic differentiation accompanied by plasticity in growth related traits. Plants grew faster and produced more biomass when placed at low elevation. In contrast, we observed fixed ecotypic differentiation for defence and resistance traits. Generally, low elevation ecotypes produced higher chemical defences regardless of the growing elevation. Yet, some plasticity was observed for specific compounds, such as indole glucosinolates. The results of this study may suggest that ecotypic differentiation in defence traits is maintained by costs of chemical defence production, while plasticity in growth traits is regulated by temperature driven growth response maximization

Secondary prevention and lifestyle indices after stroke in a long-term perspective

OBJECTIVES: To describe the long-term perspective regarding prevalence of risk factors, secondary stroke prevention, and lifestyle indices after stroke.METHODS: From a population-based one-year cohort (n = 416), we performed an observational study of 145 survivors at 16 months and 10 years after stroke (age 27-97 years) regarding secondary prevention including reaching acceptable treatment goals; nutritional status with focus on underweight; and the lifestyle indices: living situation, level of dependence, and self-assessed health condition.RESULTS: Ten years after stroke, 50% of the subjects with hypertension diagnosis and 55% of those without hypertension diagnosis were within the blood pressure goal <140/90 compared with 32% (P = .008) and 37% (N.S.) at 16 months. Acceptable HbA1c levels among subjects with diabetes mellitus diagnosis increased from 35% to 45% (N.S.). Among those without diabetes diagnosis, satisfactory HbA1c levels decreased from 98% to 79% (P < .001). Underweight increased from 9% to 17% (P = .019). Among patients with cerebral infarction, the prevalence of atrial fibrillation increased from 22% to 29% (P = .004), and treatment with oral anticoagulants from 75% to 78% (N.S.). Acceptable LDL cholesterol levels increased from 59% to 80% (P = .033) among subjects on lipid lowering treatment, and from 18% to 40% among untreated (P = .010). At 10 years, 90% still lived in their own home. Health condition was reported as good/very good/excellent by 65%. Age, female sex, and living situation were associated with intensity of secondary prevention measures and underweight.CONCLUSIONS: The proportion of individuals within treatment goals improved over time, but secondary prevention still needed additional consideration 10 years after stroke

A genetic risk score for hypertension associates with the risk of ischemic stroke in a Swedish case-control study.

Genetic risk scores (GRS), summing up the total effect of several single-nucleotide polymorphisms (SNPs) in genes associated with either coronary risk or cardiovascular risk factors, have been tested for association with ischemic stroke with conflicting results. Recently an association was found between a GRS based on 29 SNPs discovered by genome-wide association studies and hypertension. The aim of our study was to investigate the possible association of the same GRS with ischemic stroke on top of other 'traditional risk factors', also testing its potential improvement in indices of discrimination and reclassification, in a Swedish case-control study. Twenty-nine SNPs were genotyped in 3677 stroke cases and 2415 controls included in the Lund Stroke Register (LSR), the Malmö Diet and Cancer (MDC) study and the Sahlgrenska Academy Study on Ischemic Stroke (SAHLSIS). The analysis was conducted in the combined sample, and separately for the three studies. After adjustment for hypertension, diabetes mellitus and smoking habits, the GRS was associated with ischemic stroke in the combined sample (OR (95% CI) 1.086 (1.029-1.147) per SD increase in the GRS P=0.003) with similar trends in all three samples: LSR (1.050 (0.967-1.140); P=0.25), MDC (1.168 (1.060-1.288); P=0.002) and SAHLSIS (1.124 (0.997-1.267); P=0.055). Measures of risk discrimination and reclassification improved marginally using the GRS. A blood pressure GRS is independently associated with ischemic stroke risk in three Swedish case-control studies, however, the effect size is low and adds marginally to prediction of stroke on top of traditional risk factors including hypertension.European Journal of Human Genetics advance online publication, 8 October 2014; doi:10.1038/ejhg.2014.212

Supplementary Material for: Multiplicity of Risk Factors in Ischemic Stroke Patients: Relations to Age, Sex, and Subtype - A Study of 2,505 Patients from the Lund Stroke Register

<b><i>Background:</i></b> The prevalence of risk factors for ischemic stroke may vary between different groups of stroke patients. We examined the distribution of individual well-established risk factors as well as the multiplicity of risk factors in different age groups and among subtypes. <b><i>Methods:</i></b> In the Lund Stroke Register, we consecutively enrolled 2,505 patients with first-ever ischemic stroke from 2001 to 2009 and registered hypertension, diabetes mellitus, heart disease, current smoking, hypercholesterolemia as well as stroke subtype. <b><i>Results:</i></b> Among young patients (<55 years), at least 50% had ≥2 risk factors and 20-25% had ≥3 risk factors. In patients aged 55 years or older, the proportion with ≥2 risk factors was 70-80% and with ≥3 risk factors 35-45%. Men and women had a similar burden of risk factors. Approximately 50% of the cases classified as cardioembolism (CE) and large artery atherosclerosis (LAA) had ≥3 risk factors, which was significantly more than the other TOAST (Trial of Org 10172 in Acute Stroke Treatment) subtypes (CE p < 0.001, LAA p = 0.001). <b><i>Conclusions:</i></b> The prevalence of well-established risk factors is similar among young and old stroke patients with large proportions (50-80%) having ≥2 risk factors. Even though the prevalence of well-established risk factors differs between pathogenetic subtypes, these risk factors as well as the multiplicity of risk factors seem to be of clinical importance in all major subtypes of ischemic stroke