Project description:Adriatic islanders have a high prevalence of metabolic syndrome that is not fully explained by previous behavioral, dietary, and genetic studies. Some DNA methylation remains stable and may be established in early life, whereas others are dynamic and may vary over time in response to different conditions. The objective of the present study was to identify stable and dynamic DNA methylation loci associated with cardiometabolic traits among the populations from the island of Hvar, the largest island in the eastern Adriatic coast. An epigenome-wide association study (EWAS) was conducted using peripheral blood that was longitudinally collected at two time points, 10 years apart. DNA methylation was analyzed via Infinium MethylationEPIC BeadArray. Stable and dynamic loci were identified using linear mixed models. A total of 43,041 loci were classified as stable, while 45,769 loci were classified as dynamic. Associations between various cardiometabolic traits and stable and dynamic methylation loci were respectively assessed using linear mixed effects models adjusted for age, sex, and smoking status. After adjustment for false-discovery rate, 24 CpG loci were significantly associated with systolic blood pressure (Q < 0.1), of which 22 were stable loci and 2 were dynamic loci; while 12/22 (55%) of the systolic blood-pressure-associated stable loci resided in a gene promoter. Additionally, there was one stable locus associated with serum calcium and one with C-reactive protein. The results suggest that multiple genes involved in the determination of systolic blood pressure may be regulated via epigenetic programming established in early life.
Project description:Background Chronic sustained pressure overload induces cardiac remodeling, which often leads to heart failure. Cardiac macrophages (cMacs) are heterogeneous cell populations, and their elimination has been shown to exacerbate pressure overload-induced heart failure. CD163, a macrophage-specific scavenger receptor expressed in a subset of cMacs, has been linked to cardiovascular events through its serum soluble form. This study aimed to elucidate the functional role of the CD163+ cMacs subset in pressure overload-induced heart failure. Methods Transverse aortic constriction (TAC) was performed on wild-type and CD163-deficient (Cd163-/-) mice to investigate the role of CD163 in pressure overload-induced cardiac remodeling and heart failure. Echocardiography was used to assess heart structure and function. Transcriptomic analysis and transmission electron microscopy were employed to observe mitochondrial structure in cardiomyocytes. Flow cytometry was used to quantify cMacs and cytokine-expressing cMacs in the heart. Additionally, serum samples from hypertensive patients with and without heart failure were analyzed to explore the relationship between CD163 and heart failure. Results TAC-induced left ventricular systolic dysfunction, including reduced ejection fraction and fractional shortening, was significantly aggravated in Cd163-/- mice post-surgery. Genes differentially expressed due to CD163 deficiency were enriched in pathways related to mitochondrial bioenergetics and homeostasis. Transmission electron microscopy revealed an increase in dysfunctional mitochondria in cardiomyocytes of Cd163-/- mice post-TAC. Additionally, decreased serum interleukin (IL)-10 levels and reduced IL-10 expression in cMacs were observed in Cd163-/- mice post-TAC. IL-10 supplementation significantly reversed TAC-induced reductions in left ventricular systolic function and improved mitochondrial bioenergetics and homeostasis in Cd163-/- mice. Conclusions The protective functions of CD163 in cMacs are associated with IL-10 expression during pressure overload-induced heart failure.