Mesenchymal stem cells overexpressing Ang1 attenuates phosgene-induced acute lung injury in rats.

Phosgene-induced acute lung injury (P-ALI) is characterized by inflammation and effective treatments are lacking. Angiopoietin-1 (Ang1) has the beneficial effects on P-ALI. Mesenchymal stem cells (MSCs) have the potential for re-epithelization and recovery in lung injury. Thus, we hypothesized that Ang1 expressing MSCs would have beneficial effects on P-ALI. Here, an Ang1 expressing lentiviral vector was constructed and infected into rat bone marrow MSCs. Histological analyses revealed significant pathological improvements especially after treatment with MSCs in the rats exposed to phosgene. Ang1 facilitated the homing of MSCs to injured lung tissue and significantly increased expression of both epithelial cell marker Aquaporin-5 (AQP5) and surfactant protein-C (SPC) in the lung tissues. Moreover, MSCs-Ang1 reduced level of pro-inflammatory cytokines TGF-β1 and IL-1β and increased the expression of the anti-inflammatory cytokine IL-10 in the serum and bronchoalveolar lavage fluid (BALF) of P-ALI rats. In conclusion, our results suggest that Ang1 may improve the therapeutic potential of MSCs for P-ALI treatment.