Age-related histone H3.3 accumulation associates with a repressive chromatin in mouse tibialis anterior muscle.

The present study aimed to investigate age-related changes in histone variant H3.3 and its role in the aging process of mouse tibialis anterior muscle. H3.

Muscle type-specific RNA polymerase II recruitment during PGC-1α gene transcription after acute exercise in adult rats.

Epigenetic regulation of gene expression differs between fast- and slow-twitch skeletal muscles in adult rats, although the precise mechanisms are still unknown. The present study investigates the differences in responses of RNA polymerase II (Pol II) and histone acetylation during transcriptional activation in the plantaris and soleus muscles of adult rats after acute treadmill running. We targeted the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) gene to analyze epigenomic changes by chromatin immunoprecipitation.

Amount of daily exercise is an essential stimulation to alter the epigenome of skeletal muscle in rats.

Long-term running training causes epigenetic changes in the skeletal muscles. Here we tested the effects of the total amount or duration of running training on the distribution of histones in the rat plantaris muscle. Post-weaned young rats were assigned to 3 different training groups: Run-1, 30 min/day running exercise for 8 wk using an animal treadmill at 24 m/min; Run-2, 15 min/day for 8 wk; and Run-3, 60 min/day for 4 wk.

Running training experience attenuates disuse atrophy in fast-twitch skeletal muscles of rats.

Responsiveness to physiological stimuli, such as exercise and muscular inactivation, differs in individuals. However, the mechanisms responsible for these individual differences remain poorly understood. We tested whether a prior experience of exercise training affects the responses of skeletal muscles to unloading.

Prenatal myonuclei play a crucial role in skeletal muscle hypertrophy in rodents.

Multinucleated muscle fibers are formed by the fusion of myogenic progenitor cells during embryonic and fetal myogenesis. However, the role of prenatally incorporated myonuclei in the skeletal muscle fibers of adult animals is poorly understood. We demonstrated, using muscle-specific reporter mice, that the prenatal myonuclei remained in the adult soleus muscle, although cardiotoxin injection caused the loss of prenatal myonuclei.