Protective role and mechanism of dexmedetomidine on the LPS-stimulated PC12 cells

Objective To explore the effect of dexmedetomidine on the lipopolysaccharide (LPS) stimulated PC12 cells and its potential mechanism. Methods PC12 cells were treated by LPS with a concentration of 400μg/ml. The cell viability, the concentrations of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in the cell culture supernatant were measured after 3-, 6-, or 12-h treatment. The expressions of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and phosphorylated p65 (p-p65) were measured. In the second part, PC12 cells were cultured under four different treatments, that is, normal culture media in first group, 400μg/ml LPS in second group, 100μmol/L dexmedetomidine in third group, 400μg/ml LPS and100μmol/L dexmedetomidine in fourth group. The indexes mentioned above were measured 6 hours after LPS and DEX treatments. Results The cell viability was decreased after LPS treatment, and the concentrations of IL-6 and TNF-α were increased significantly. Compared with control group, the concentrations in 3-, 6-, 12-h groups showed statistically significant differences (P<0.05), especially after 6 hours. The TLR4/MyD88/NF-κB pathway was activated after LPS stimuli and reached the peak value. Compared with LPS treatment group, PC12 cell apoptosis rate, the concentrations of IL-6 and TNF-α and the expressions of TLR4, MyD88 and p-p65 were decreased. The differences between LPS+DEX group and LPS group was statistically significant (P