Features and function of exosomes secreted by heat-stroke vascular endothelial cells / 解放军医学杂志

ABSTRACT

Objective To characterize exosomes released from human umbilical vein endothelial cells (HUVECs) after heatstroke, and explore their effects on biological behaviors of cells. Methods HUVECs were cultured and divided into the control group and the heat shock group. The heat shock group cells were exposed at 41 ℃ for 2 hours; the control group cells were incubated at 37 ℃ for 2 hours. The characteristics of exosomes secreted by the two groups were analyzed by nanoparticle tracing. The expression of exosomes marker proteins, CD63 and TSG101, were detected by Western blotting. The process of exosomes entering normal cells was observed by fluorescence labeling. To further explore the potential function of exosomes secreted from the heat-shocked cells, cells were co-cultured with exosomes collected from cells cultured at 37 ℃ or cells cultured at 41 ℃. Cells under normal culture conditions were served as a negative control (blank control). FACS was used to detect cell cycle and apoptosis; MTS was used to evaluate cell proliferation; ELISA was used to quantify coagulation related factor expression; high-throughput sequencing was used to profile microRNAs (miRNAs) in the exosomes. Results Different from the control group, the cells in 41 ℃ heat shock group secreted abnormal exosomes, which resulted in abnormal behaviors and functions of normal HUVECs. The expression of tissue factor, von Willebrand factor, plasminogen activator inhibitor-1 increased significantly (P<0.05), and the expression of tissue plasminogen activator decreased (P<0.05). Compared with the incubation of HUVECs at 37 ℃, there were 2590 miRNA regulatory changes in exosomes secreted by HUVECs after heat shock at 41 ℃, which had obvious effects on apoptosis. Conclusions Heat shock at 41 ℃ could induce the release of abnormal exosomes from HUVEC, leading to abnormal behavior and potential coagulation of normal cells.