Effects of S100A12 gene silencing on serum levels of anti-inflammatory/pro-inflammatory cytokines in septic rats through the ERK signaling pathway.

We explored the effect of S100A12 gene on serum levels of anti-inflammatory/pro-inflammatory cytokines in septic rats by activating the extracellular signal-regulated kinase (ERK) signaling pathway. A total of 180 specific pathogen-free (SPF) rats were purchased to establish cecal ligation and puncture (CLP) model. Rats were assigned into the sham, model, empty vector, S100A12 siRNA, epidermal growth factor (EGF), and S100A12 siRNA + EGF groups. The expressions of S100A12, ERK-1, ERK-2, cPLA2, and NF-κB in liver tissues of rats among six groups were detected by RT-qPCR and western blotting. ELISA was used to determine serum levels of IL-1β, IL-10, TNF-α, procalcitonin (PCT), and C-reactive protein (CRP). Pearson correlation analysis was conducted to measure correlations. Cell apoptosis of rats among six groups was detected by Tunel staining. The expressions of S100A12, ERK-1, ERK-2, cPLA2, and NF-κB decreased in the S100A12 siRNA group while increased in the EGF group compared with the model group. S100A12 mRNA expression was positively correlated with mRNA expressions of related genes in the ERK signaling pathway (ERK-1, ERK-2, cPLA2, and NF-κB) in the model and empty vector groups. Expressions of IL-1β, IL-6, TNF-α, PCT, and CRP in the EGF group were higher than those in the model group, but were lower than those in the S100A12 siRNA group. Compared with the model group, cell apoptosis decreased in the S100A12 siRNA group but that increased in the EGF group. We demonstrates that S100A12 gene silencing decreases serum levels of anti-inflammatory/pro-inflammatory cytokines in septic rats by inhibiting the ERK signaling pathway.