Mesenchymal Stromal Cells (MSCs): A Promising Tool for Cell-Based Angiogenic Therapy

The Mesenchymal stromal cells (MSCs) are a diverse subset of adult multipotent precursors, known for their potential therapeutic properties in regenerative medicine mainly sustained by paracrine effects through secretion of a variety of biologically active molecules. MSC secretome includes a wide range of soluble protein factors, composed of growth factors and cytokines, and vesicular components, which transfer proteins and genetic material modulating the host microenvironment. In particular, MSC-derived secretome mediates the different steps of the angiogenic process, inducing endothelial cell functions in vitro and promoting angiogenesis in vivo. As a result, MSCs have been widely explored as a promising cell-based therapy in diseases caused by insufficient angiogenesis. Numerous studies of myocardial infarction, ischemic stroke, and critical limb ischemia in animals have shown that human MSCs can enhance angiogenesis and accelerate tissue regeneration. This extensive preclinical work encouraged the study of these remarkable cells for the treatment of these disorders in human clinical settings. The present review provides a comprehensive overview of the pro-angiogenic potential of MSCs and paracrine effectors of their secretome. In addition, bioengineering strategies, including ex vivo preconditioning and genetic modification approaches, to enhance MSC innate angiogenic properties, and thereby therapeutic potency, will be presented. Finally, an update on completed preclinical and clinical studies with MSCs for the treatment of ischemia-related diseases will be discussed.