Production of hepatocyte growth factor from human lung microvascular endothelial cells induced by interleukin-1beta

To investigate the possible role of hepatocyte growth factor (HGF) in the reconstruction process following inflammatory damage in lung tissue, we compared HGF production of human lung microvascular endothelial cells (HLWECs) and human umbilical vein endothelial cells (HUVECs) after stimulation by interleukin(IL)-1beta. In an HLMEC-conditioned medium, large amounts of total (single and 2-chain) HGF were detected, and were 26- to 28-fold higher than those in HUVECs or human lung fibroblasts. The production of total HGF increased in a dose-dependent manner (4.7 to 9.2 times) with IL-1beta. In contrast, the amount of HGF in an HUVEC-conditioned medium was unaffected by IL-1beta treatment. The amount of cell-associated HGF also showed a dose-related increase (140% to 160%) in HLMECs, but not in HUVECs with IL1beta. In addition, HGF and c-met (HGF receptor) mRNAs in HLMECs and HUVECs were examined by the RT-PCR method. HGF and c-met mRNAs were clearly detected in HLMECs before and after treatment with IL-1beta, but not in HUVECs. These results suggest that increases in HGF production from HLMECs may play a role in the reconstruction process following inflammatory damage in lung tissue.