Abstract
Activated microglia, involved in the occurrence and improvement of sepsis-associated encephalopathy, can induce the expression of pro-inflammatory cytokines and pro-inflammatory enzymes, resulting in inflammation-mediated neuronal cell death. It was reported that propofol could inhibit lipopolysaccharide (LPS) induced pro-inflammatory cytokine and pro-inflammatory enzyme expression in BV2 and primary microglial cells. However, the underlying mechanism is not well known. In the present study, we investigated whether and how propofol inhibited LPS-induced the expression of pro-inflammatory cytokines and pro-inflammatory enzymes in BV2 cells. LPS induced pro-inflammatory cytokine and pro-inflammatory enzyme expression, NF-κB, extracellular regulated kinase 1/2 (ERK), calcium (Ca2+)/calmodulin-dependent protein kinase II (CaMK II) phosphorylation, and BV2 cell Ca2+ accumulation. Propofol could reverse these effects induced by LPS. MK801, an inhibitor of the NMDA receptor, could attenuate LPS-induced Ca2+ accumulation, the expression of pro-inflammatory cytokines and pro-inflammatory enzymes, and phosphorylation of NF-κB, ERK, and CaMK II, which was similar to propofol. Moreover, these effects of propofol could be counteracted by rapastinel, an activator of the NMDA receptor. The present study suggested that propofol, via inhibiting the NMDA receptor, attenuating Ca2+ accumulation, and inhibiting CaMK II, ERK1/2, and NF-κB phosphorylation, down-regulated LPS-induced pro-inflammatory cytokine and pro-inflammatory enzyme expression.