Effects of Propofol on Toll-like Receptor 4 Signal Pathway in Alveolar Macrophages Induced by Lipopolysaccharide

Aim: To investigate the effects of propofol on toll-like receptor 4 (TLR4) signaling pathway induced by lipopolysaccharide (LPS) in alveolar macrophages (AMs). Methods: AMs isolated from 10 patients were cultured for 1 hour. These cells were pooled and randomly divided into five groups. The final concentrations of LPS and propofol were 1μg/mL and 30μM, respectively. AMs were continually cultured for 24 hours after LPS addition. RT-PCR and real-time RT-PCR analyses were performed to quantify the cellular expression of TLR4 mRNA; activities of cellular NF-κB were detected; and TNF-α and IL-6 in cultural supernate were measured. Results: After AMs were stimulated by LPS, the expression of TLR4 mRNA and NF-κB activation were significantly increased, and the production of TNF-α and IL-6 enhanced drastically. Co-treatment of propofol and LPS, or treatment of propofol 1 hour before LPS, significantly inhibited the expression of TLR4 mRNA and the activation of NF-κΒ, and decreased the production of TNFα and IL-6. Conclusions: Early administration of propofol at a therapeutic concentration inhibited TLR4 signal pathway induced by LPS