Molecular components, immune and stem cells in soft tissue regeneration

Wound healing is  a  spatiotemporal and  highly regulated process that is  divided into  four continuous and  overlapping stages: hemostasis, inflammation, repair (proliferation) and remodeling. All stages are controlled by various body systems and depend on the regulatory role of immune and stem cells. Despite significant progress in  understanding the  cellular and  molecular mechanisms of  inflammation, the role of the immune microenvironment in the regeneration process remains unclear. On the one hand, the critical importance of the cellular and molecular components of the immune system in the reparative response of tissues, including the degree of scarring, restoration of structure and function of organs, has been proven, and on the other hand, little data is presented on the loss of tissue regeneration ability associated with  the  immune competence evolution. The  review presents the  key cellular and molecular mechanisms of the immune response and of the stem cells participation soft tissue repair process during their interaction with the extracellular matrix. An analysis of the latest scientific data on the participation of components of  the  immune microenvironment and  of  stem cells in  soft tissue repair process was  carried  out based on  the  publications presented in  Google Scholar, Medline, PubMed, Scopus and Web of Science. It has been shown that the nature of this response and its duration have a significant impact on the outcome of repair – from incomplete recovery (scarring or fibrosis) to full regeneration. It is indicated that various types of immune and stem cells take part in the soft tissue repair and remodeling processes, and their interaction must be precisely controlled. The review data may provide the basis for the development of new therapeutic approaches for soft tissue repair through immune regulation or the use of stem cells and extracellular vesicles.