Genetic Modification of Mesenchymal Stem Cells Overexpressing Angiotensin II Type 2 Receptor Increases Cell Migration to Injured Lung in LPS-Induced Acute Lung Injury Mice

Although mesenchymal stem cells (MSCs) transplantation has been shown to promote the lung respiration in acute lung injury (ALI) in vivo, its overall restorative capacity appears to be restricted mainly because of low retention in the injured lung. Angiotensin II (Ang II) are upregulated in the injured lung. Our previous study showed that Ang II increased MSCs migration via Ang II type 2 receptor (AT2R). To determine the effect of AT2R in MSCs on their cell migration after systemic injection in ALI mice, a human AT2R expressing lentiviral vector and a lentivirus vector carrying AT2R shRNA were constructed and introduced into human bone marrow MSCs. A mouse model of lipopolysaccharide-induced ALI was used to investigate the migration of AT2R-regulated MSCs and the therapeutic potential in vivo. Overexpression of AT2R dramatically increased Ang II-enhanced human bone marrow MSC migration in vitro. Moreover, MSC-AT2R accumulated in the damaged lung tissue at significantly higher levels than control MSCs 24 and 72 hours after systematic MSC transplantation in ALI mice. Furthermore, MSC-AT2R-injected ALI mice exhibited a significant reduction of pulmonary vascular permeability and improved the lung histopathology and had additional anti-inflammatory effects. In contrast, there were less lung retention in MSC-ShAT2R-injected ALI mice compared with MSC-Shcontrol after transplantation. Thus, MSC-ShAT2R-injected group exhibited a significant increase of pulmonary vascular permeability and resulted in a deteriorative lung inflammation. Our results demonstrate that overexpression of AT2R enhance the migration of MSCs in ALI mice and may provide a new therapeutic strategy for ALI.