[The effects of activated protein C on the von Willebrand factor and von Willebrand factor cleaving protease of rat aortic endothelial cell induced by lipopolysaccharide].

Objective: To investigate the activated protein C (APC) on the von Willebrand factor antigen (vWFAg) and von Willebrand factor cleaving protease (ADAMTS-13) protein expression in rat aortic endothelial cells (RAECs) induced by lipopolysaccharide (LPS).

Methods: RAECs from Wistar rats were cultured with the tissue explants adherence method. RAECs were cultured for one week, After one week culture, RAECs in 4-5 generations were divided into control group, LPS stimulation groups (1 mg/L) and APC intervention groups (0.1, 1 and 10 mg/L APC was added after LPS stimulation). The supernatants were obtained at 12, 24, 48, and 72 hours after LPS stimulated to determine the vWFAg and protein of ADAMTS-13 expression by enzyme-linked immunoadsorbent assay (ELISA).

Results: In the control group, RAECs expressed little vWFAg and protein of ADAMTS-13. With stimulation of LPS, the vWFAg was significantly increased at 12 hours, and reached the peak at 48 hours [(285.45±30.13)%], and the level of ADAMTS-13 (μg/L) was gradually decreased, and reached the nadir at 72 hours (13.32±2.37), there was significant difference compared with control group [vWFAg: (94.53±7.83)%, ADAMTS-13: 115.76±2.36, both P<0.01). The effects on vWFAg promoting and ADAMTS-13 inhibition after LPS stimulation could be dose-dependently reversed by APC. 10 mg/L of APC could decrease the peak of vWFAg at 48 hours of LPS stimulation [(198.43±17.92)% vs. (285.45±30.13)%], and increase the minimize of ADAMTS-13 (μg/L) at 72 hours of LPS stimulation (125.25±2.70 vs. 13.32±2.37), with significant difference (both P<0.01).

Conclusions: After stimulation with LPS, the level of vWFAg was time-dependent increased, as the protein of ADAMTS-13 was decreased. APC could attenuate the effect of LPS on vWFAg and protein of ADAMTS-13 with dose-dependent and time-dependent patterns.