Abstract:

Acute lung injury（ALI）is a critical clinical syndrome，characterized by progressive respiratory failure and stubborn hypoxemia，which can develop into highly fatal acute respiratory distress syndrome（ARDS）. Although the pathophysiology and treatment of ALI have been extensively studied，there is still a lack of effective therapies and prevention methods for ALI. Mesenchymal stem cells（MSCs）have been increasingly studied for the treatment of ALI because of their differentiation potential and low immunogenicity. The therapeutic effect of MSCs is partially exerted in a paracrine manner by releasing extracellular vesicles（EVs）. MSC⁃EVs contain a variety of mRNA，miRNA，cytokines，proteins and other substances，which can promote the repair and regeneration of damaged tissues. This article reviewed the biological characteristics of MSC⁃EVs，mechanism of action in treating ALI and latest progress in clinical trials，with the aspiration that MSC⁃EVs will become a new treatment strategy for ALI in the future.

Key words: mesenchymal stem cells,  , extracellular vesicles,  , acute lung injury,  , acute respiratory distress syndrome,  , exosomes