Distinguishable DNA methylation defines a cardiac-specific epigenetic clock.

BACKGROUND: The present study investigates whether epigenetic differences emerge in the heart of patients undergoing cardiac surgery for an aortic valvular replacement (AVR) or coronary artery bypass graft (CABG). An algorithm is also established to determine how the pathophysiological condition might influence the human biological cardiac age. RESULTS: Blood samples and cardiac auricles were collected from patients who underwent cardiac procedures: 94 AVR and 289 CABG. The CpGs from three independent blood-derived biological clocks were selected to design a new blood- and the first cardiac-specific clocks. Specifically, 31 CpGs from six age-related genes, ELOVL2, EDARADD, ITGA2B, ASPA, PDE4C, and FHL2, were used to construct the tissue-tailored clocks. The best-fitting variables were combined to define new cardiac- and blood-tailored clocks validated through neural network analysis and elastic regression. In addition, telomere length (TL) was measured by qPCR. These new methods revealed a similarity between chronological and biological age in the blood and heart; the average TL was significantly higher in the heart than in the blood. In addition, the cardiac clock discriminated well between AVR and CABG and was sensitive to cardiovascular risk factors such as obesity and smoking. Moreover, the cardiac-specific clock identified an AVR patient's subgroup whose accelerated bioage correlated with the altered ventricular parameters, including left ventricular diastolic and systolic volume. CONCLUSION: This study reports on applying a method to evaluate the cardiac biological age revealing epigenetic features that separate subgroups of AVR and CABG.

The human immunoglobulin heavy diversity (IGHD) and joining (IGHJ) segments.

The 'Human Immunoglobulin Heavy Diversity (IGHD) and Joining (IGHJ) segments', fifth report of the 'IMGT Locus on Focus' section, comprises six tables entitled: (1) 'Human germline IGHD segments at 14q32.33'; (2) 'Human IGHD alleles'; (3) 'Human germline IGHJ segments at 14q32.33'; (4) 'Human IGHJ alleles'; (5) 'Human germline IGHD orphons on chromosome 15 (15q11.2)'; (6) 'Correspondence between the different human IGHD nomenclatures', and two figures: (1) 'Protein display of human IGH D-REGIONs'; (2) 'Protein display of human IGH J-REGIONs'. These tables and figures are available at the IMGT Marie-Paule page from IMGT, the international ImMunoGeneTics database (http://imgt.cnusc.fr:8104) created by Marie-Paule Lefranc, Université Montpellier II, CNRS, France.