IL-6 /STAT-3 signaling pathway regulates the expression of high mobility group proteins 1 in intestinal mucosa of rats with sepsis / 中华急诊医学杂志

ABSTRACT

Objective To explore whether the IL-6/STAT3 signaling pathway regulate the expression of high mobility group proteins1 (HMGB1) in intestinal mucosa of rats with sepsis through the cecum ligation puncture (CLP). Methods One hundred and twenty male SD rats were randomly(random number) divided into three groups sham operation group (group S, n=40), CLP group(group C, n=40) and anti-IL-6 monoclonal antibody group (group T, n=40). Rats in group S only received the simple laparotomy;Rats in group C and group T were established as a rat model of sepsis using CLP; rats in group T received the intraperitoneal injection of anti-IL-6 monoclonal antibody at 1 h after CLP, while the same volume of sodium lactate ringer's solution was injected to rats in group S and group C. Ten rats in each group were sacrificed at 3, 12, 24 and 48 h, respectively, and intestinal mucosa specimens were collected for pathological examinations by HE staining. The protein expression of HMGB1 and IL-6 were detected by immunohistochemistry, STAT3-protein by Western blot.and the levels of diamine oxidase (DAO) and D lactic acid in plasma by spectrophotometric. Results Rats in group C and group T showed obvious intestinal damage to different degrees, significantly higher intestinal mucosa pathological scores and plasma levels of DAO and D-lactic acid compared with rats in group S (P<0.05). The protein expression of IL-6, HMGBl and p-STAT3 of intestinal mucosa in group C and group T also significantly increased compared with that in group S (P<0.05). The intestinal mucosa pathological score, plasma levels of DAO and D-lactic acid and protein expression of IL-6, HMGBl and STAT3 were decreased in group T compared with those in group C (P<0.05). The intestinal mucosa pathological scores were positively correlated with the protein expression of IL-6 and HMGB1 at 12, 24, and 48 h, respectively. Conclusions IL-6 and HMGBl were involved in the intestinal injury of septic rats. IL-6/STAT3 signaling pathway could up-regulate the expression of HMGB1 in intestinal mucosa of septic rats.