Project description:Caloric restriction (CR) is one of the most robust interventions shown to delay aging in diverse species, including rhesus monkeys (Macaca mulatta). Identification of factors involved in CR brings a promise of translatability to human health and aging. Here, we show that CR induced a profound change in abundance of circulating microRNAs (miRNAs) linked to growth and insulin signaling pathway, suggesting that miRNAs are involved in CR’s mechanisms of action in primates. Deep sequencing of plasma RNA extracts enriched for short species revealed a total of 243 unique species of miRNAs including 47 novel species. Approxi- mately 70% of the plasma miRNAs detected were conserved between rhesus monkeys and humans. CR induced or repressed 24 known and 10 novel miRNA species. Regression analysis revealed correlations between bodyweight, adiposity, and insulin sensitivity for 10 of the CR-regulated known miRNAs. Sequence alignment and target identification for these 10 miRNAs identify a role in signaling downstream of the insulin receptor. The highly abundant miR-125a-5p correlated positively with adiposity and negatively with insulin sensitivity and was negatively regulated by CR. Putative target pathways of CR- associated miRNAs were highly enriched for growth and insulin signaling that have previously been implicated in delayed aging. Clustering analysis further pointed to CR-induced miRNA regula- tion of ribosomal, mitochondrial, and spliceosomal pathways. These data are consistent with a model where CR recruits miRNA- based homeostatic mechanisms to coordinate a program of delayed aging.
Project description:We recruited ten normal-weight healthy men using inclusion criteria as previously described (Collet et al 2017). All males were healthy and not obese or overweight (average age: 23.8 years, average BMI (kg/m2): 23.3). Participants at baseline consumed a balanced diet (50% carbohydrate, 30% fat, and 20% protein). During caloric restriction, volunteers consumed 10% of normal energy requirement (226 kcal/d) for two days, again balanced (50% carbohydrate, 30% fat, and 20% protein), with the same macronutrient composition. After caloric restriction, volunteers were offered three substantial ad libitum buffet meals per day (20 MJ = 4,777 kcal) and additional snacks (16 MJ = 3,821 kcal) between meals for 2 days. They were invited to eat freely until comfortably full; food consumption was covertly measured. We collected fasting plasma samples at 0800 AM at baseline, after CR and refeeding (RF).