Mesenchymal stem cells in treating human diseases: molecular mechanisms and clinical studies

Mesenchymal stem cells (MSCs) have emerged as a highly promising strategy in regenerative medicine due to their self-renewal, pluripotency and immunomodulatory properties. MSCs are nonhematopoietic, multipotent stem cells that can differentiate into various mesodermal lineages and modulate the immune system. The therapeutic potential of MSCs from different tissues has been widely explored in preclinical models and clinical trials for human diseases, ranging from autoimmune diseases and inflammatory disorders to neurodegenerative diseases and orthopedic injuries. The therapeutic effects of MSCs can be mediated through the release of bioactive molecules, including growth factors, cytokines, and extracellular vesicles, which play crucial roles in modulating the local cellular environment, promoting tissue repair, angiogenesis, and cell survival, and exerting anti-inflammatory effects. MSCs can also interact with various immune cells, such as T cells, B cells, dendritic cells, and macrophages, modulating the immune response through both direct cell‒cell interactions and the release of immunoregulatory molecules. This review delves into the molecular mechanisms, signaling pathways, and regulatory factors that underpin the therapeutic effects of MSCs. This review also highlights the clinical applications and challenges associated with the use of MSC-based drugs to promote the safety and efficacy of MSC-based therapies. Overall, this comprehensive review provides valuable insights into the current state of MSC research and its potential for transforming the field of regenerative medicine as well as immune-mediated inflammatory diseases.