[Induction of expression of von Willebrand factor cleaving protease of rat aortic endothelial cell by lipopolysaccharide challenge].

OBJECTIVE: To investigate the dose response effect and time response effect of lipopolysaccharide(LPS) on von Willebrand factor cleaving protease (ADAMTS-13, Vwf-cp) mRNA expression and protein in rat aortic endothelial cells (RAECs). METHODS: RAECs were grown by culturing of aortic tissue. When ARECs were cultured for one week, it was co-cultured by 1:3 to reach 4-5 generations. ARECs were randomly divided into five groups: control group and four LPS stimulation groups (0.01, 0.1, 1 and 5 µg/ml) . The RAECs and supernatants were obtained at 12, 24, 48, and 72 hours after being stimulated by LPS. ADAMTS-13 mRNA expression of RAECs was assessed by quantitation reverse transcription-polymerase chain reaction (RT-PCR), and protein of ADAMTS-13 in supernatants was determined by enzyme linked immunoadsorbent assay (ELISA). RESULTS: In the control group RAECs were shown to express ADAMTS-13 at both protein and mRNA levels. With the increase of concentration of LPS, or increase in stimulus duration, expression of ADAMTS-13 mRNA and protein were gradually lowered. Compared with the control group (25.22 ±1.41), the level of ADAMTS-13 mRNA in 0.01 µg/ml LPS stimulation group was markedly decreased at 48 hours (18.78±0.86, P<0.01). At 24 hours, the levels of ADAMTS-13 mRNA (23.43±0.63, 22.41±0.76) were markedly decreased in 0.1 µg/ml and 1 µg/ml LPS stimulation groups (P<0.05 and P<0.01). The level of ADAMTS-13 mRNA (20.01±2.47) in 5 µg/ml LPS stimulation group was markedly decreased at 12 hours (P<0.01). Compared with the control group [(115.76±2.36) ng/ml], protein level of ADAMTS-13 [(113.43±1.07) ng/ml] was markedly decreased at 12 hours in 0.01 µg/ml LPS stimulation group (P<0.05). The protein level of ADAMTS-13 [(7.63±2.64) ng/ml] was lowest in 5 µg/ml LPS stimulation group at 72 hours (P<0.01). CONCLUSION: Normal RAECs can express ADAMTS-13 at both mRNA and protein to certain extent. The expression of ADAMTS-13 mRNA and protein are decreased after LPS challenge in different concentrations for different duration in dose dependent and time dependent manner.

[Effect of Xuebijing injection on expression of endothelial protein C receptor and protease activated receptor 1 mRNA and protein in endothelial cells induced by lipopolysaccharide].

OBJECTIVE: To investigate the effect of Xuebijing injection on expression of endothelial protein C receptor (EPCR) and protease activated receptor 1 (PAR1) mRNA and protein in rat aortic endothelial cells (RAECs) after lipopolysaccharide (LPS) challenge. METHODS: RAECs were cultured for one week, and the purity was determined with flow cytometry. ARECs were randomly divided into four groups: control group, LPS stimulation group (1 mg/L LPS), Xuebijing injection treatment group (LPS: 1 mg/L, Xuebijing injection ; 10 g/L) and activated protein C (APC) treatment group (LPS: 1 mg/L, APC: 0.1 mg/L). The RAECs were collected at 12, 24, 48, and 72 hours after being stimulated by LPS. EPCR and PAR1 mRNA of RAECs were assessed by reverse transcription-polymerase chain reaction (RT-PCR). EPCR and PAR1 protein were assessed by flow cytometry. RESULTS: At 12 hours, EPCR and PAR1 protein expressions were not significantly different among groups (all P>0.05). The level of EPCR and PAR1 mRNA were decreased in LPS stimulation group, but they were elevated in both APC and Xuebijing injection treatment groups (P<0.05 or P<0.01). From 24 to 72 hours, compared to control group, the levels of EPCR mRNA and protein expression were significantly decreased after LPS stimulation (P<0.05 or P<0.01). The levels of EPCR expression were decreased and negatively correlated with the time of LPS treatment. Also, compared to LPS stimulation group, treatment with Xuebijing markedly elevated the levels of EPCR (P<0.01). The levels of PAR1 expression were significantly decreased by LPS stimulation compared with those of control group (P<0.05 or P<0.01). After the treatment with Xuebijng, the expression of PAR1 was gradually increased (all P<0.01). Compared with APC treatment group, Xuebijing could increase the PAR1 expression better. CONCLUSION: Xuebijing could raise EPCR and PAR1 mRNA and protein expression of RAECs after LPS challenge, and it may be related to its protection of endothelial cell from undergoing apoptosis.