Project description:The goal of these studies was to determine the effects of fasting on skeletal muscle mRNA levels in healthy human subjects. Seven healthy adult human subjects fasted for 40 hours and then a muscle biopsy (fasting sample) was obtained from the vastus lateralis muscle. Immediately after the first muscle biospy, subjects then ate a mixed meal. Six hours after the first muscle biopsy, a second muscle biopsy (fed sample) was obtained from the contralateral vastus lateralis muscle. In each subject, mRNA levels under fasting conditions were normalized to mRNA levels under fed conditions, which were set at 1.
Project description:ATF4 is a fasting-induced trascription factor that promotes skeletal muscle atrophy. The goal of these studies was to determine how of loss of ATF4 affects skeletal muscle mRNA expression. For additional details see Ebert et al, Stress-Induced Skeletal Muscle Gadd45a Expression Reprograms Myonuclei and Causes Muscle Atrophy. JBC epub. June 12, 2012. Muscle-specfic ATF4 knockout (ATF4 mKO) mice and littermate controls were fasted for 24 hours and then tibialis anterior muscles were harvested. mRNA levels in ATF4 mKO muscles were normalized to levels in littermate control muscles.
Project description:Fasting increases the level of skeletal muscle ATF4 mRNA, which promotes skeletal myofiber atrophy. To begin to determine the mechanism of ATF4-mediated myofiber atrophy, we compared the effects of fasting and ATF4 overexpression on global skeletal muscle mRNA expression in C57BL/6 mice.
Project description:Fasting increases the level of skeletal muscle ATF4 mRNA, which promotes skeletal myofiber atrophy. To begin to determine the mechanism of ATF4-mediated myofiber atrophy, we compared the effects of fasting and ATF4 overexpression on global skeletal muscle mRNA expression in C57BL/6 mice.
Project description:The aim of the study was to investigate how short-term fasting affects whole-body energy homeostasis and skeletal muscle energy/nutrient-sensing pathways and transcriptome in humans. For this purpose, twelve young healthy men were studied during a 24-hour fast. Skeletal muscle biopsies were collected and analyzed at baseline and after 4, 10 and 24h of fasting. As expected, fasting induced a time-dependent decrease in plasma insulin and leptin levels, whereas levels of ketone bodies and free fatty acids increased. This was associated with a metabolic shift from glucose towards lipid oxidation. Transcriptome profiling identified genes that were significantly regulated by fasting in skeletal muscle at both early and late time-points. Collectively, our study provides a comprehensive map of the main energy/nutrient-sensing pathways and transcriptomic changes during short-term adaptation to fasting in human skeletal muscle
