Effect of Aging on Mitochondrial Energetics in the Human Atria

Energy production in myocardial cells occurs mainly in the mitochondrion. Although alterations in mitochondrial functions in the senescent heart have been documented, the molecular bases for the aging-associated decline in energy metabolism in the human heart are not fully understood. The purpose of our study was to identify aging-related transcriptional changes in genes coding for mitochondrial proteins involved in substrate metabolism, oxidative phosphorylation system (OXPHOS), and the tricarboxylic acid (TCA) cycle, and to correlate these with the functional changes in the OXPHOS in human atrial appendage tissue from adult and aged patients free of atrial pathologies. We examined transcription profiles of genes coding for mitochondrial proteins in atrial tissue from aged (> 65 years old) and comorbidities-matched adult (< 65 years old) patients with preserved left ventricular function using high throughput microarray (Human Genome U133 Plus 2.0 arrays) and verified by RT-PCR.