急性肺损伤(Acute lung injury,ALI)和急性呼吸窘迫综合征(Acute respiratory distress syndrome,ARDS)是以低氧血症和肺部浸润为主要表现的临床危重症,致死率较高,目前临床以支持治疗为主,尚无有效的药物治疗方法。近年来研究发现,间充质干细胞(Mesenchymal stem cells,MSCs)在ALI/ARDS治疗方面有极大的潜力。治疗机制目前报道有免疫调节、增殖分化修复、抗菌作用等。炎性状态下微环境的改变对肺干细胞的行为及MSCs对ALI/ARDS的治疗有重要的影响,但具体作用 Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are clinical critically ill patients with hypoxemia and pulmonary infiltrates as the main manifestation. The mortality rate is relatively high Supportive treatment, there is no effective drug treatment. In recent years, studies have found that mesenchymal stem cells (MSCs) have great potential in the treatment of ALI / ARDS. Treatment mechanisms currently reported immune regulation, proliferation and differentiation repair, antibacterial effects. Changes of microenvironment in inflammatory state have important effect on the behavior of lung stem cells and the treatment of ALI / ARDS by MSCs, but the specific effect