Stable methylation loci are associated with systolic blood pressure in a Croatian island population.

Background: The objective was to identify stable and dynamic DNA methylation loci associated with cardiometabolic traits among an adult population from the Croatian island of Hvar. Materials & methods: An epigenome-wide association study was conducted using peripheral blood longitudinally collected at two time points 10 years apart via Infinium MethylationEPIC beadarray (n = 112). Stable and dynamic loci were identified using linear mixed models. Associations between cardiometabolic traits and loci were assessed using linear models. Results: 22 CpG loci were significantly associated with systolic blood pressure. Twenty were stable and two were dynamic. Conclusion: Multiple genes may be involved in the determination of systolic blood pressure level via stable epigenetic programming, potentially established earlier in life.

Cardiovascular disease is the leading cause of death worldwide. Previous studies have found that genetics incompletely explain susceptibility to cardiovascular disease. To find new potential risk factors, the authors investigated the possible contribution of DNA methylation (modifications to DNA that can affect gene expression but do not alter the underlying genetic code) in an adult population on the Croatian island of Hvar, which has a high number of people with cardiovascular and metabolic disease. By examining DNA methylation in blood collected at two time points, 10 years apart, the authors were able to identify DNA methylation that either stayed the same over time (stable) or changed the most over time (dynamic). These were then compared with clinical test results related to cardiovascular or metabolic diseases to determine if they are associated. Twenty-two methylation sites were found to be associated with systolic blood pressure. Of those, 20 were considered stable and two were dynamic. Additionally, there was one stable methylation site associated with serum calcium and one with C-reactive protein. These findings suggest that systolic blood pressure may be regulated through stable DNA methylation that is potentially established earlier in life.

Notch Regulates Innate Lymphoid Cell Plasticity during Human NK Cell Development.

Human NK cells develop in tonsils through discrete NK cell developmental intermediates (NKDIs), yet the mechanistic regulation of this process is unclear. We demonstrate that Notch activation in human tonsil-derived stage 3 (CD34-CD117+CD94-NKp80-) and 4A (CD34-CD117+/-CD94+NKp80-) NKDIs promoted non-NK innate lymphoid cell differentiation at the expense of NK cell differentiation. In contrast, stage 4B (CD34-CD117+/-CD94+NKp80+) NKDIs were NK cell lineage committed despite Notch activation. Interestingly, whereas NK cell functional maturation from stage 3 and 4A NKDIs was independent of Notch activation, the latter was required for high NKp80 expression and a stage 4B-like phenotype by the NKDI-derived NK cells. The Notch-dependent effects required simultaneous engagement with OP9 stromal cells and were also stage-specific, with NOTCH1 and NOTCH2 receptors regulating stage 3 NKDIs and NOTCH1 primarily regulating stage 4A NKDIs. These data establish stage-specific and stromal-dependent roles for Notch in regulating human NK cell developmental plasticity and maturation.