Accepted_test

Skeletal muscle makes up more than a third of human body mass; with a normal level of physical activity, skeletal muscles play a key role in the regulation of carbohydrate and fat metabolism and insulin sensitivity of the organism. Chronic decrease in motor activity (disuse) causes a decrease in the ability of muscles to oxidize fats and carbohydrates, reduces insulin sensitivity, the content of mitochondria and muscle mass, which has a negative impact on human metabolism and performance. Interestingly, the severity of the negative effects of disuse varies for different muscles for example, in m. soleus (the back part of the calf) is larger than that in m. vastus lateralis (the front part of the thigh). However, the molecular mechanisms explaining these differences are clearly not well understood.

The purpose of the work is to compare transcriptomic changes in the calf and thigh muscles after three weeks of disuse and to identify genes associated with a common and unique response to disuse.

We showed, that three-week disuse has a more pronounced effect on the phenotype (functional capabilities and relative protein content) of the calf muscles than the thigh muscles. These differences appear to be closely related to changes in the transcriptomic profile of m. soleus and m. vastus lateralis, which allowed us to identify common and unique mechanisms underlying the different responses of these muscles. The results obtained open up prospects for the search for pharmacological approaches to targeted prevention of decreased functional capabilities of various muscles during disuse.