Hepatocyte growth factor (HGF) secreted by human mesenchymal stem cells (hMSCs) following mesenchymal stem cell-endothelial cell (MSC-EC) interactions upregulated vascular endothelial (VE)-cadherin protein and decreased caveolin-1 protein expression. Compared with the MSC group, MSC-EC interaction increased VE-cadherin protein expression (P <0.01) (A, C) while reducing caveolin-1 protein expression in human pulmonary microvascular endothelial cells (HPMECs) (P <0.01) (B, D). However, the MSC effect was significantly blocked by anti-HGF antibody (P <0.05 or P <0.01) (C, D). These results indicated that HGF secreted by hMSCs upregulated endothelial VE-cadherin protein and decreased caveolin-1 protein expression. (n=3, * *p < 0.01 vs. group LPS, # p < 0.01 vs. MSC; & p< 0.05 && p < 0.01 vs. group MSC-EC interaction) LPS, lipopolysaccharide.