Hepatocyte growth factor (HGF) secreted in mesenchymal stem cell-endothelial cell (MSC-EC) interactions conditions restored remodelling of endothelial F-actin. The results indicated that human pulmonary microvascular endothelial cells cultured under normal condition had F-actin localised mainly at the cell periphery. Lipopolysaccharide (LPS) induced dispersion of F-actin. After 7 days of direct or indirect co-culture with human MSCs, remodelling of F-actin was partially restored. However, neutralising HGF from conditioned media with anti-HGF antibody caused F-actin to be disrupted again. DAPI, 4,6-diamidino-2-phenylindole.