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Biology subjects

Raitakari, O. T.

Publications and source records attributed to Raitakari, O. T..

6 recordsLinked to original sources

Male youth BMI is associated with epigenetic ageing of female descendants but not blood or sperm DNA methylation

Studies based on harvest records indicate that grandparental nutrition in youth is associated with the health traits of grandchildren in a sex-specific lineage. We investigated whether male early adulthood anthropometrics associate with epigenetic age, a measure of general well-being, and DNA methylation, a potential molecular inheritance mechanism, in three generations of descendants. Data on weight, height, BMI and chest circumference measured at military draft examinations (at age 18-24 yrs.) were retrieved from national archives for 1,013 men, herein referred to as Generation Archives (GA). The genome-wide DNA methylation of their descendants participating in the Young Finns Study (YFS) was measured from the blood and sperm from the children (59-80 yrs., nblood = 362, nsperm = 51), grandchildren (34-49 yrs., nblood = 421, nsperm = 98) and great-grandchildren (7-30 yrs., nblood = 200). The men's (GA) BMI had an inverse association with the epigenetic pace of ageing (DunedinPACE) of their daughters ({beta} = -0.01, p = 0.002, n = 169) and the daughters' daughters ({beta} = -0.01, p = 0.049, n = 126) but not with that of their male descendants. From within the YFS cohort, maternal, but not paternal, BMI at ages 13-34 also had an inverse association with the DunedinPACE of the immediate offspring. However, robust evidence for the inheritance mechanism was not found in the analyses between the anthropometric measurements of the GA men and the DNA methylation profiles in the blood and sperm of their descendants.

molecular biology↗

Traditional disease risk factors outperform epigenetic clocks as predictors of non-communicable disease morbidity in a middle-aged cohort

DNA methylation-based epigenetic clocks have been highlighted as promising biomarkers of ageing, and they have been shown to robustly predict morbidity and mortality. However, current literature is lacking a formal analysis of the increased prediction accuracy, or the added value, of the epigenetic clocks over traditional risk factors of common chronic diseases. Here, we have compared the most commonly used epigenetic clocks and traditional risk factors as predictors of incidence of ageing-associated non-communicable chronic disease in a 7-to-9-year follow-up in a middle-aged population cohort (n=1108, aged 34 to 49 years at baseline). In our cohort, a statistical model consisting of a combination of traditional risk factors outperforms any model including an epigenetic clock. The added value of epigenetic clock measurements over simple and affordable traditional risk factors should be clearly established, if epigenetic clocks are to be used in clinical settings or as tools of personal health monitoring.

molecular biology↗

Suppression of non-canonical autophagy induces endothelial and cardiac dysfunction

BackgroundWhile roles for canonical autophagy in the pathophysiology of cardiovascular disease have been established, we have limited understanding of the non-canonical functions of autophagy proteins in this context. LC3-asssociated endocytosis (LANDO) is a novel non-canonical function of autophagy proteins, in which LC3 (microtubule-associated protein light chain 3) is conjugated to early endosome membranes using a portion of the canonical autophagy machinery, and functions in the endocytic recycling of several plasma membrane proteins. Here we ask whether perturbation of LANDO can promote cardiovascular pathogenesis. MethodsCardiac and endothelial functions were assessed by echocardiography and flow-mediated dilatation in mice lacking Rubicon (Rubcn-/-) or the WD domain of ATG16L1 (Atg16l1{Delta}WDki), two known effectors of LANDO. Mice with conditional depletion of Rubicon in the endothelial, myeloid and cardiomyocyte compartments were used as well. Three-dimensional murine cardiac vasculature leakiness was investigated by light sheet fluorescence microcopy. Endothelial activation induced by shear stress was characterized in vitro in primary endothelial cells isolated from murine lungs and human aortic endothelial cells. Associations between genetically predicted expression of candidate genes involved in LANDO and human cardiovascular parameters were studied in the Young Finns Study and the UK Biobank. ResultsCompared to littermate controls, young Rubcn-/- and Atg16l1{Delta}WDki mice showed a decrease in cardiac and endothelial functions, as did mice with endothelium-specific deficiency. VEGFR2 recycling to the plasma membrane and nitric oxide pathway during shear stress were disrupted in LANDO-deficient primary murine and human endothelial cells. Proteomic analysis in primary human aortic endothelial cells revealed an upregulation of intracellular hemoglobin subunit alpha (Hb-) upon shear stress, which was blunted when RUBCN was ablated. Genetic expression studies uncovered several candidate genes related to LANDO that correlated with cardiovascular parameters. These included the retromer complex subunit VPS29, disruption of which decreased Hb- expression levels in human endothelial cells. ConclusionsOur data support a pivotal role of non-canonical functions of autophagy proteins in recycling VEGFR2 upon shear stress activation in endothelial cells together with Hb- expression that may contribute to the etiology of cardiovascular diseases.

physiology↗

Genetic variation in apolipoprotein A-I concentrations and risk of coronary artery disease

RationaleApolipoprotein A-I (apoA-I) infusions represent a potential novel therapeutic approach for the prevention of coronary artery disease (CAD) with phase III cardiovascular outcome trials currently underway. Although circulating apoA-I levels inversely associate with risk of CAD, the evidence base of this representing a causal relationship is lacking.\n\nObjectiveTo assess the causal role of apoA-I in CAD using human genetics.\n\nMethods and ResultsWe identified a variant (rs12225230) in APOA1 locus that associated with circulating apoA-I concentrations at GWAS significance (P<5x10-8) in 20,370 Finnish participants and meta-analyzed our data with a previous genome-wide association study of apoA-I. We obtained genetic estimates of CAD from UK Biobank and CARDIoGRAMplusC4D (totaling 122,733 CAD cases) and conducted a two-sample Mendelian randomization analysis. We compared our genetic findings to observational associations of apoA-I with risk of CAD in 918 incident CAD cases among 11,535 individuals from population-based prospective cohorts. We also summarized the available evidence from randomized controlled trials (RCTs) of apoA-I infusion therapies reporting CAD events. ApoA-I was associated with a lower risk of CAD in observational analyses (HR 0.81; 95%CI: 0.75, 0.88; per 1-SD higher apoA-I), with the association showing a dose-response relationship. Rs12225230 associated with apoA-I concentrations (per-C allele beta 0.076 SD; SE: 0.013; P=1.5x10-9) but not with potential confounders. In Mendelian randomization analyses, apoA-I was not related to risk of CAD (OR 1.13; 95%CI: 0.98, 1.30 per 1-SD higher apoA-I), which was different to the observational association (P-het<0.001). RCTs of apoA-I infusions did not show an effect on the risk of CAD.\n\nConclusionsGenetic evidence fails to support a cardioprotective role for apoA-I. This casts doubt on the likely benefit of apoA-I infusion therapy in the ongoing phase III cardiovascular outcome trial.

epidemiology↗

Multivariate genome-wide association analysis of a cytokine network reveals variants with widespread immune, haematological and cardiometabolic pleiotropy

Cytokines are essential regulatory components of the immune system and their aberrant levels have been linked to many disease states. Despite increasing evidence that cytokines operate in concert, many of the physiological interactions between cytokines, and the shared genetic architecture that underlie them, remain unknown. Here we aimed to identify and characterise genetic variants with pleiotropic effects on cytokines - to do this we performed a multivariate genome-wide association study on a correlation network of 11 circulating cytokines measured in 9,263 individuals. Meta-analysis identified a total of 8 loci significantly associated with the cytokine network, of which two (PDGFRB and ABO) had not been detected previously. Bayesian colocalisation analysis revealed shared causal variants between the eight cytokine loci and other traits; in particular, cytokine network variants at the ABO, SERPINE2, and ZFPM2 loci showed pleiotropic effects on the production of immune-related proteins; on metabolic traits such as lipoprotein and lipid levels; on blood-cell related traits such as platelet count; and on disease traits such as coronary artery disease and type 2 diabetes.

genomics↗

Lower hemoglobin levels associate with lower body mass index and healthier metabolic profile

Hemoglobin (Hb) is the main carrier of oxygen. In general, high-end Hb levels within the normal range are considered beneficial for health1. However, activation of the hypoxia response has been shown to protect mice against metabolic dysfunction2-4. We used Hb levels as an indicator for oxygenation status and studied its association with >170 anthropometric and metabolic parameters in two Finnish birth cohorts both in cross-sectional and longitudinal design (max n = 7,175). Here we show a positive linear association between Hb levels and body mass index (BMI). Subjects with the lower Hb levels had better glucose tolerance, lower cholesterol and blood pressure levels, less adverse metabolite profiles and lower inflammatory load. Notably, these associations were not only mediated by the lower BMI, and the effect size of many of them increased with age. Polygenic risk score (PRS) analyses indicated shared genetic determinants between Hb levels and BMI, insulin, triglyceride and HDL cholesterol levels. Mendelian randomization (MR) analyses could not demonstrate causal relationships between Hb and metabolic parameters. However, manipulation of Hb levels by venesection in mice showed evidence for causal associations with body weight and metabolic parameters. Our findings suggest that lower-end normal Hb levels may be favorable for systemic metabolism involving mild chronic activation of the hypoxia response. Therefore modulation of Hb levels could be a novel strategy towards maintenance of metabolic health.

epidemiology↗