Role of Sirt3 expression in peritoneal macrophages in dexmedetomidine-induced inhibition of inflammatory responses in septic mice / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of nicotinamide adenine dinucleotide-dependent deacetylase Sirtuin3 (Sirt3) expression in peritoneal macrophages in dexmedetomidine-induced inhibition of inflammatory responses in septic mice.Methods:Sixty-four healthy male C57BL/6 mice, aged 7 weeks, weighing about 20 g, were divided into 4 groups ( n=16 each) using a random number table method: sham operation group (S group), sepsis group (Sep group), dexmedetomidine group (DEX group), and dexmedetomidine plus Sirt3 inhibitor 3-TYP group (TYP group). Sepsis was induced by cecal ligation and puncture.In group DEX, normal saline 0.25 ml was intraperitoneally injected at 1 h before development of the model, and 30 min later dexmedetomidine 50 μg/kg (in 0.25 ml of normal saline) was intraperitoneally injected.In group S and group Sep, the equal volume of normal saline was intraperitoneally injected at 1 h and 30 min before development of the model, respectively.In group S, laparotomy and cecal extraction were performed without ligation and perforation.Peritoneal lavage was obtained at 24 h after operation, and peritoneal macrophages were cultured for 1 h. The expression of Sirt3, interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) mRNA in peritoneal macrophages was detected using quantitative real-time polymerase chain reaction.Western blot was used to detect the expression of Sirt3 in peritoneal macrophages.The concentrations of IL-1β and TNF-α in peritoneal fluid were measured by enzyme-linked immunosorbent assay.The 10-day survival of mice in each group was observed, and the survival rates were calculated. Results:Compared with group S, the expression of Sirt 3 protein and mRNA in peritoneal macrophages was significantly down-regulated, the expression of IL-1β and TNF-α mRNA was up-regulated, the concentrations of IL-1β and TNF-α in peritoneal lavage were increased, and the 10-day survival rates were decreased in Sep, DEX and TYP groups ( P<0.05). Compared with group Sep, the expression of Sirt3 protein and mRNA in peritoneal macrophages was significantly up-regulated, the expression of IL-1β and TNF-α mRNA was down-regulated, the concentrations of IL-1β and TNF-α in the peritoneal lavage were decreased, and the 10-day survival rate was increased in group DEX ( P<0.05). Compared with group DEX, the expression of Sirt3 protein and mRNA and IL-1β and TNF-α mRNA in peritoneal macrophages was significantly up-regulated, the concentrations of IL-1β and TNF-α in peritoneal lavage were increased, and the 10-day survival rate was decreased in group TYP ( P<0.05). Conclusions:Up-regulation of Sirt3 expression in peritoneal macrophages is involved in the process of dexmedetomidine-induced inhibition of inflammatory responses in septic mice.