Participation of Mesenchymal Stromal Cells in Muscle Tissue Regeneration

Mesenchymal stromal cells (MSCs) are considered as universal regulators of tissue homeostasis. Their use is promising for repair of skeletal muscles after injuries and diseases. The main participants of muscle regeneration are myosatellites, but resident MSCs also play a role in it. In addition, MSCs come from bone marrow to the injured muscle for its reparation. MSCs are capable of myogenic differentiation and fusion with muscle cells. However, paracrine secretion of regulatory molecules by MSCs is more important for regeneration. They promote survival, proliferation and differentiation of cells in the injured muscle. Factors secreted by MSCs affect all stages of reparative process. This allows using MSCs for complex delivery of bioactive molecules. Prospects for the use of MSCs have been demonstrated in various experimental models of muscle damage such as mechanical and chemical injuries, atrophy, ischemia, genetically determined muscular dystrophy. Improving the delivery of MSCs in the muscle can increase the efficiency of regeneration. Cell transplantation on artificial scaffolds allows to achieve this goal. Ultrasound treatment of muscles also concentrates MSCs at the site of injury. Magnetic delivery of the cells is another way to increase their concentration. The paracrine activity of MS Cs can be enhanced by preconditioning them with different stimuli that changes the secretory profile of cells in the desired direction. Genetic modification of MSCs also increases their therapeutic potential. MSCs produce extracellular vesicles with regulatory molecules such as miRNAs. The use of these vesicles and molecules is a new area of regenerative medicine. Activation of MSCs stimulates tissue regeneration due to internal reserves and, therefore, can be considered as a tool of in vivo tissue engineering.