Recombinant Domain V of beta (2)-Glycoprotein I Inhibits OxLDL-induced TF Expression in Macrophages

Objective: To investigate if lectin-like oxidised low density lipoprotein receptor is implicated in oxidised low density lipoprotein induced up-regulation of tissue factor and whether recombinant domain V of beta (2)-Glycoprotein I expressed in Pichia pastoris inhibits the binding of oxidised and lectin-like low density lipoprotein. Methods: The expression of tissue factor and lectin-like oxidised low density lipoprotein receptor was detected using Western blot methods. Small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor was used to block lectin-like oxidised low density lipoprotein receptor expression. Flow cytometry was used to test the effect of beta (2)-Glycoprotein I expressed in Pichia pastoris on the binding of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor by using the lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. Results: Oxidised low density lipoprotein at 5-10 mu g/mL increased tissue factor and lectin-like oxidised low density lipoprotein receptor expression, whereas 20-50 mu g/mL oxidised low density lipoprotein attenuated tissue factor expression. Inhibiting lectin-like oxidised low density lipoprotein receptor expression by small interference ribonucleic acid of lectin-like oxidised low density lipoprotein receptor impaired oxidised low density lipoprotein-induced tissue factor over expression in macrophages. Pretreatment with beta (2)-Glycoprotein I expressed in Pichia pastoris led to a strong inhibition of tissue factor and lectin-like oxidised low density lipoprotein receptor expression in a dose-dependent manner in macrophages. Flow cytometry analysis showed that beta (2)-Glycoprotein I expressed in Pichia pastoris attenuated the interaction of oxidised low density lipoprotein with lectin-like oxidised low density lipoprotein receptor in lectin-like oxidised low density lipoprotein receptor-expressing 293T cells. Conclusions: Lectin-like oxidised low density lipoprotein receptor was implicated in the expression of tissue factor induced by oxidised low density lipoprotein, and beta (2)-Glycoprotein I expressed in Pichia pastoris inhibited oxidised low density lipoprotein-induced tissue factor and lectin-like oxidised low density lipoprotein receptor expression, at least in part, via inhibition of the interaction between oxidised low density lipoprotein and lectin-like oxidised low density lipoprotein receptor.