AIM:To explore the effects of galectin-3 (GAL-3) on the viability, migration and inflammation of human umbilical vein endothelial cells (HUVECs) and the mechanisms.METHODS:The HUVECs were cultured in vitro and treated with GAL-3 recombinant protein at 2 mg/L or GAL-3 short hairpin RNA (shRNA).The HUVECs were divided into normal group, recombinant GAL-3 group, shControl group and GAL-3-shRNA group.The mRNA expression of GAL-3, monocyte chemotactic protein (MCP)-1, IL-6, matrix metalloproteinase (MMP)-9 and cyclin D1 was detected by real-time quantitative PCR,and the protein expression of GAL-3, IL-6 and MCP-1 was detected by Western blot.The secretion levels of MCP-1 and IL-6 in the culture medium were measured by ELISA.The viability and the ability of migration of the HUVECs were examined by CCK-8 assay and wound healing assay.The protein levels of heat shock protein 90 (HSP90), ERK1/2, p-ERK1/2, JNK and p-JNK were determined by Western blot.RESULTS:The expression of GAL-3, MCP-1 and IL-6 at mRNA and protein levels, the mRNA expression of MMP-9 and cyclin D1, and the secretion levels of MCP-1 and IL-6 in the culture medium were significantly higher than those in normal group (P<0.05) after the HUVECs were treated with GAL-3 recombinant protein.However, these molecules mentioned above in GAL-3-shRNA group were significantly lower than those in normal group and negative control group (P<0.05).Compared with normal group, the viability and migration ability of the HUVECs in recombinant GAL-3 group were significantly increased, but the viability and migration ability of the HUVECs in GAL-3-shRNA group were lower than those in normal group and shControl group (P<0.05).In addition, the protein levels of p-ERK1/2 and HSP90 in recombinant GAL-3 group were higher than those in normal group (P<0.05), but those in GAL-3-shRNA group were lower than those in normal group and shControl group (P<0.05).The protein level of p-JNK was not oviously changed among the 4 groups.CONCLUSION:GAL-3 is involved in regulating the cell growth, migration and the release of inflammatory cytokines in vascular endothelial cells, which may be mediated by HSP90-ERK1/2 signaling pathway.