Oxidized low-density lipoprotein induced lectin-like oxidized low-density lipoprotein receptor-1 expression in hepatic sinusoidal endothelial cells

Objective To investigate the presence of lectin-like oxidized low-density lipoprotein(ox-LDL) receptor-1 (LOX-1) in cultured hepatic sinusoidal endothelial cells (HSECs), and meanwhile discuss the regulation of its mechanisms under ox-LDL injury conditions. Methods The mRNA and protein expression of LOX-1 was testified by real-time quantitative polymerase chain reaction(RT-PCR) and Western blotting methods. Meanwhile HSECs were stimulated with different concentration of ox-LDL (0, 20, 40, 60, 80 and 100 mg/L) for 24 h, and HSECs were stimulated with 80 mg/L for different times (0, 12, 24 and 48 h). Then expression of LOX-1 mRNA was measured by RT-PCR, and the protein expression of LOX-1 was testified by using Western blotting. Data were analyzed with one-way ANOVA and t test. Results LOX-1 exists in HSECs. After intervened with 20-80 mg/L ox-LDL for 24 h, LOX-1 mRNA and protein levels increased significantly in a dose-dependent manner(F=38.7, 3.48, both P<0.05). However, when concentration of ox-LDL reached 100 mg/L, the LOX-1 mRNA and protein expression decreased significantly compared with those intervened with 80 mg/L ox-LDL (t=23.75, 18.26, both P<0.05). Meanwhile, after intervened with 80 mg/L ox-LDL at different time (0-24 h), the expression of LOX-1 mRNA and protein significantly increased in a time-manner(F=2.36, 0.328, both P<0.05). And compared with those in cells intervened for 24 h, the mRNA and protein expression of LOX-1 decreased significantly when intervened for 48 h(t=69.21, 36.27, both P<0.05). However, compared with the cells incubated with 80 mg/L ox-LDL, the mRNA and protein expression of LOX-1 significantly decreased in HSECs treated with polyinosinic cytidylic acid(t=54.93, 28.19, both P<0.05). Conclusion LOX-1 exists in HSECs and ox-LDL could regulate it in a certain reach of concentration and time. However, polyinosinic cytidylic acid can partly restrained ox-LDL-induced LOX-1 expression. Key words: Hepatic sinusoidal endothelial cells; Oxidized low-density lipoprotein; Lectin-like oxidized low-density lipoprotein receptor-1