Monocyte chemotactic protein-1-induced protein 1 (MCPIP1) plays a important role in ischemia/ reperfusion (I/R) injury. Autophagy is involved in activating endothelial cells in response to I/R. However, researchers have not clearly determined whether MCPIP1 mediates I/R injury in endothelial cells via autophagy, and its downstream mechanism remains unclear. Western blotting analyses and immunocytochemistry were applied to detect protein levels were detected in HUVECs. An in vitro scratch assay was used to detect cell migration. Cells were transfected with siRNAs to knockdown MCPIP1 and high mobility group box 1 (HMGB1) expression. The pharmacological activator of autophagy rapamycin and the specific calcium-sensing receptor (CaSR) inhibitor NPS-2143 were used to confirm the roles of autophagy and CaSR in I/R injury. I/R induced HMGB1 and CaSR expression, which subsequently upreguated the migration and apoptosis of HUVECs and coincided with the increase of autophagy. HMGB1 was involved in cell migration, whereas CaSR specifically participated in I/R-induced HUVEC apoptosis. Based on these findings, I/R-induced MCPIP1 expression regulates the migration and apoptosis of HUVECs via HMGB1 and CaSR, respectively, suggesting a new therapeutic targetof I/R injury.Vascular endothelial cell dysfunction plays an crucial role in ischemia/reperfusion (I/R) injury, a common aspect of cardiovascular disease that is characterized by the over-production of inflammatory factors, such as cytokines and chemokines 1,2 . Various biological events, such as autophagy, endoplasmic reticulum stress (ERS) and ubiquitination, are involved in endothelial cell dysfunction. Autophagy plays an important role in the ability of cells to adapt to changing environmental conditions and in cellular remodeling during angiogenesis [3][4][5][6] . However, the mechanisms underlying I/R-induced endothelial cell dysfunction that are associated with autophagy remain poorly understood.Based on accumulating evidence, monocyte chemotactic protein-1 (MCP-1) and its downstream molecule MCP-1-induced protein 1 (MCPIP1) facilitate vascular inflammation and endothelial dysfunction in response to I/R 1, [7][8][9][10] . For example, MCPIP1 has been shown to induce angiogenesis during placental vasculogenesis, which in turn leads to vascular remodeling [11][12][13] . Interestingly, recent studies have linked MCP-1/MCPIP1 with autophagy under different conditions that induce cell activation and apoptosis. For instance, MCP-1 and MCPIP1 contribute to cardiomyoblast death in patients with heart failure and are associated with autophagy resulting from ERS 14 . Moreover, MCPIP1-induced autophagy is required for angiogenesis in patients with angiogenesis-related cardiovascular diseases 15 . On the other hand, MCPIP1/p53 expression is induced after SiO2 exposure and promotes macrophage activation and apoptosis, suggesting the presence of a general link between the MCPIP1 signaling pathway and autophagy in different diseases 16,17 .