Genetic modification and preconditioning strategies to enhance functionality of mesenchymal stromal cells: a clinical perspective

Mesenchymal stromal cell (MSC)-based therapy has generated great hope for the treatment of various diseases such as myocardial infarction and stroke. Unfortunately, MSC-based therapy faces major hurdles in its translation to clinical practice. To address these issues, preconditioning and genetic modification strategies have been developed. Through preconditioning, MSCs are cultured under sub-lethal conditions of environmental stresses or treated with specific drugs, biomolecules, and growth factors. Genetic modification is a procedure in which specific genetic sequences are transferred into the MSCs via viral vectors or CRISP/Cas9 in order to alter the expression of distinctive genes.In this article, a comprehensive review on preconditioning and gene modification inducers, mechanisms of action, and their impacts were discussed. In addition, clinical trials that used preconditioned and genetic modified MSCs are debated.Numerous preclinical investigations have demonstrated that preconditioning and genetic modifications considerably enhance MSC's therapeutic capacity through improving their survival rate, antioxidant activity, growth factor secretion, immunomodulation, homing efficiency, and angiogenesis. For MSC preconditioning and genetic modification to achieve clinical translation, remarkable outcomes in clinical trials are of pivotal importance.