👤 Michael Brauer

Brain-derived neurotrophic factor (BDNF) is a key neurotrophin due to its role in neuron process outgrowth, plasticity, and neuronal survival. Aerobic exercise can induce BDNF release and may ultimately maximize post-stroke recovery. This study aimed to determine if a program of moderate-to-high-intensity aerobic exercise increased concentrations of BDNF in subacute stroke survivors compared to usual care. A parallel-group, RCT was undertaken in people with subacute stroke undergoing rehabilitation. Participants were randomly allocated to usual care (control group) or usual care plus an 8-week program of moderate-high intensity treadmill walking (3 x 30 min sessions per week) (experimental group). Serum BDNF was collected by blinded assessors at baseline (Week 0), at the end of the intervention period (Week 8), and at 6 months follow up (Week 26). Sixty-seven participants ( As concentrations of BDNF increased immediately after a program of aerobic exercise, this may present a potential neurobiological mechanism to enhance recovery after stroke. Show less

Long-term exposure to air pollution has been associated with higher risk of cardiovascular mortality. Less is known about the association of air pollution with initial development of cardiovascular disease. Herein, the association between low-level exposure to air pollutants and subclinical carotid atherosclerosis in adults without known clinical cardiovascular disease was investigated. Cross-sectional analysis within a prospective cohort study. The Canadian Alliance for Healthy Hearts and Minds Cohort Study; a pan-Canadian cohort of cohorts. Canadian adults (n = 6645) recruited between 2014-2018 from the provinces of British Columbia, Alberta, Ontario, Quebec, and Nova Scotia, were studied, for whom averages of exposures to nitrogen dioxide (NO2), ozone (O3), and fine particulate matter (PM2.5) were estimated for the years 2008-2012. Carotid vessel wall volume (CWV) measured by magnetic resonance imaging (MRI). In adjusted linear mixed models, PM2.5 was not consistently associated with CWV (per 5 μg/m3 PM2.5; adjusted estimate = -8.4 mm3; 95% Confidence Intervals (CI) -23.3 to 6.48; p = 0.27). A 5 ppb higher NO2 concentration was associated with 11.8 mm3 lower CWV (95% CI -16.2 to -7.31; p<0.0001). A 3 ppb increase in O3 was associated with 9.34 mm3 higher CWV (95% CI 4.75 to 13.92; p<0.0001). However, the coarse/insufficient O3 resolution (10 km) is a limitation. In a cohort of healthy Canadian adults there was no consistent association between PM2.5 or NO2 and increased CWV as a measure of subclinical atherosclerosis by MRI. The reasons for these inconsistent associations warrant further study. Show less

Induced pluripotent stem cells (iPSC) derived from healthy individuals are important controls for disease-modeling studies. Here we apply precision health to create a high-quality resource of control iPSCs. Footprint-free lines were reprogrammed from four volunteers of the Personal Genome Project Canada (PGPC). Multilineage-directed differentiation efficiently produced functional cortical neurons, cardiomyocytes and hepatocytes. Pilot users demonstrated versatility by generating kidney organoids, T lymphocytes, and sensory neurons. A frameshift knockout was introduced into MYBPC3 and these cardiomyocytes exhibited the expected hypertrophic phenotype. Whole-genome sequencing-based annotation of PGPC lines revealed on average 20 coding variants. Importantly, nearly all annotated PGPC and HipSci lines harbored at least one pre-existing or acquired variant with cardiac, neurological, or other disease associations. Overall, PGPC lines were efficiently differentiated by multiple users into cells from six tissues for disease modeling, and variant-preferred healthy control lines were identified for specific disease settings. Show less

Metabolic syndrome (MetS) comprises a cluster of risk factors including central obesity, hypertension, dyslipidemia, and impaired glucose homeostasis. Lifestyle interventions that promote improvements in diet quality and physical activity represent a first line of therapy for MetS. However, varying responses to lifestyle interventions are well documented and may be partially explained by underlying genetic differences. The aim of this study was to investigate if variants in genes previously associated with MetS influence the magnitude of change in MetS risk during a 1-year lifestyle intervention. The present study used data collected from the Canadian Health Advanced by Nutrition and Graded Exercise study cohort (n = 159 men and women) to investigate the effect of 17 candidate single nucleotide polymorphisms (SNPs) on response to a 1-year lifestyle intervention. Associations between SNPs and the continuous MetS (cMetS) score, as well as individual MetS components, were examined. Reductions in cMetS score at both 3 months and 1 year were significantly associated with 2 variants: rs662799 (A/G) in apolipoprotein A5 (APOA5) and rs1501299 (G/T) in adiponectin (ADIPOQ). Individuals carrying a minor T allele in rs1501299 experienced a greater reduction in cMetS score at both 3 months and 1 year, whereas major allele AA homozygotes in rs662799 experienced greater reductions in cMetS score during the intervention. No associations were identified between the aforementioned SNPs and individual components of MetS. Both un-weighted and weighted genetic risk scores (GRS) using these 2 SNPs revealed that individuals carrying none of the risk alleles experienced significantly greater reductions in cMetS score after 1 year. The findings from the current study suggest that individuals with certain genotypes may benefit more from a lifestyle intervention for MetS and that specific variants, either independently or as part of a GRS, could be used as a nutrigenomic tool to tailor the intervention to reduce the risk of MetS. Show less

The evidence supporting an association between traffic-related air pollution exposure and incident childhood asthma is inconsistent and may depend on genetic factors. To identify gene-environment interaction effects on childhood asthma using genome-wide single-nucleotide polymorphism (SNP) data and air pollution exposure. Identified loci were further analyzed at epigenetic and transcriptomic levels. We used land use regression models to estimate individual air pollution exposure (represented by outdoor NO In the European cohorts, 186 SNPs had an interaction P < 1 × 10 Our results indicated that gene-environment interactions are important for asthma development and provided supportive evidence for interaction with air pollution for ADCY2, B4GALT5, and DLG2. Show less