Molecular mechanisms of phenotypic changes in different leg skeletal muscles induced by 3-week disuse
The aim of the study was: i) to compare the changes in the phenotype and proteomic profile of the ankle flexor muscles/m. soleus and knee extensors/m. vastus lateralis after three weeks of head-down tilt bed rest, and ii) to assess the extent to which mRNA profile changes induced by disuse affect the proteomic profile of these muscles (i.e. the extent to which changes in protein concentration in these muscles are regulated at the level of mRNA). For this purpose, the mass of the thigh and calf muscles, their maximum voluntary contraction, and aerobic performance were measured before and after disuse, and compared to the maximum mitochondrial respiration rate and proteomic (global quantitative mass spectrometry-based proteomic) and transcriptomic (RNA-sequencing) profiles of samples from m. soleus and m. vastus lateralis.