Paracrine effects of mesenchymal stem cells: future perspectives

Mesenchymal stem cells are a cell population with the ability to self-replicate and differentiate into various types of somatic cells. The present review focuses on the potential of mesenchymal stem cell cultures for cell therapy using transplantable cells or tissue-engineered constructs, and the paracrine factors secreted by mesenchymal stem cells. The methodological aspects of the use of these cells in various diseases both in clinical and preclinical trials have been demonstrated through examples of experimental therapy, with an overview of their primary mechanisms. In the context of cell therapy, mesenchymal stem cells are of significant interest because of their abundance and renewability. Although the differentiation pathways of mesenchymal stem cells are not yet fully elucidated, the cells themselves play a pivotal role in stem cell biology in view of their regulatory properties, including immunomodulatory, antiapoptotic, proliferation-promoting, and antifibrotic effects. It is important to emphasize that the paracrine functions of mesenchymal stem cells are the primary factor contributing to their enhanced integration into tissues, when compared to induced pluripotent stem cells, particularly in the context of cardiac tissue engineering. The review also highlights the role of exogenous factors, such as substrates, in modulating the efficacy of the paracrine effects of mesenchymal stem cells, which is crucial for identifying the optimal cellular microenvironment to enhance therapeutic outcomes without adverse effects.