A primary mechanism to maintain cell homeostasis is apoptosis, a programmed or regulated form of cell death that controls the accumulation of defective cells. An imbalance of this process may result in the onset of several diseases, particularly those associated with aging. Calorie restriction has been proven to increase longevity and influence healthy aging by improving tissue performance and delaying the onset of age-related diseases. The underlying mechanisms of these effects likely involve decreased oxidative stress and optimization of mitochondrial bioenergetics in a tissue specific manner. This study investigated the effects of calorie restriction and those changes induced by the predominant fat source (lard, soybean oil, fish oil) in calorie-restricted diets on kidney apoptosis in relation to aging in mice fed experimental diets for 6 or 18 months. Markers related to apoptotic signaling, apoptotic protease activating factor 1 (APAF-1) and voltage-dependent anion channel 1 (VDAC-1), were measured for the different experimental conditions by following a Western blot methodology. Due to the role of ubiquinone (coenzyme Q, CoQ) in energy metabolism, alterations in CoQ biosynthesis may modify CoQ levels in tissues. Thus, the levels of coenzyme Q (CoQ) were determined by reversed-phase HPLC separation; also, mitochondrial cellular respiration was measured via citrate synthase mitochondrial marker enzyme. Results indicated that the distribution of APAF-1 in the cytosol demonstrates no significant effects in dietary fat source in the control groups of mice fed under calorie restriction with the exception of those in which lard is the primary source of dietary fat. These findings suggest that apoptosis signaling is deceased in calorie-restricted diets in which lard is used as the primary fat source. The distribution of VDAC-1 in mitochondria demonstrates no significant effects in dietary fat source in the control groups of mice fed under calorie restriction. Lastly, results of the levels of coenzyme Q suggest an increase with age in mice. In conclusion, the results of this study suggest that calorie restriction and the predominant fat source in calorie-restricted diets indeed induce effects on kidney apoptosis in relation to aging.
Mason, Jasmine; Ayalew, Mentewab; and . Villalba, José M., "Alteration of Mitochondrial Bioenergetics and Apoptotic Signaling with Aging in Mice Kidney: The Effects of Calorie Restriction and Dietary Fat" (2013). G-STEM Posters. 18.