"Mechanisms of Muscle Memory"
Kristian Gundersen (Professor, FYSCELL)
Memory is a cellular phenomenon. While memory has been extensively investigated in the brain and in the immune system, a cellular memory in somatic cells has received less attention. My lab has described a cellular memory in muscle cells, such that previous exercise or hormone exposure leaves long lasting cyto-architectural and epigenetic traces that can be very long lasting, that survives long periods of de - training and that seems to aid re-training. The mechanisms for the muscle memory will be discussed.
"Testosterone affects and alters the epigenome in skeletal muscle"
Mads Bengtsen (Research Fellow, BMB)
Testosterone is an anabolic steroid that induces hypertrophy through an increase in skeletal muscle mass and protein synthesis. Due to its pronounced effect, it is used both in medical treatments and as a doping agent in sports. Interestingly, it has been shown that short term treatment with the anabolic steroid creates long-lasting effects in muscle. However, how the steroid exerts its effect on the molecular level is not fully understood. To understand in more detail how testosterone affects the skeletal muscle and the regulatory program in the muscle-specific myonuclei, we treated mice with testosterone, purified the myonuclear population and analysed the epigenetic landscape of the muscle cells by ATAC-seq. Mapping of the epigenome shows that testosterone treatment induces global changes in the muscle-specific chromatin openness, both in promoter and distal-regulatory enhancer regions. Bioinformatics analyses of the differently enriched regions identified a complex regulatory network that can play a role in the increased hypertrophy and the long-term physiological effects observed by the steroid.