Role of HMGB1 in organ injury during acute necrotizing pancreatitis and protective effect of HMGB1 monoclonal antibody

Abstract

Objective To investigate the role of HMGB1 in the pathogenesis of organ injury of acute necrotizing pancreatitis (ANP).Methods Male ICR mice were randomly allocated into control group,ANP group and HMGB1 monoclonal antibody group.ANP model was induced by intraperitoneal injection of 20％ L-arginine.Mice in HMGB1 monoclonal antibody group were given intraperitoneal injection of 200 μg of HMGB1 monoclonal antibody immediately after the induction of the ANP model.All the mice were sacrificed at 12,24,and 48 h after ANP induction.Serum level of amylase and liver,renal function were determined,level of serum HMGB1 was measured by using enzyme-linked immunosorbent assay,and then the pathologic changes of pancreas and liver were routinely observed and scored.The HMGB1 mRNA levels in the liver and pancreas were studied by real time fluorescence quantitative PCR.Results The serum levels of HMGB1 at 12 h in control group,ANP group and HMGB 1 monoclonal antibody group were (9.09 ± 1.03),(25.04 ± 4.30),(16.84 ± 4.27) μg/L; and pathological scores of pancreatic tissue were (1.50 ± 0.55),(4.33 ± 0.52),(3.03 ± 0.32) points ; and HMGB1 mRNA expressions in pancreas were 0.48 ± 0.18,7.53 ± 2.71,3.26 ±2.33 ; HMGB1 mRNA expressions in liver were-1.23 ± 0.37,0.15 ± 0.65,－ 1.27 ± 0.72.The corresponding values in ANP group were significantly higher than those in control group (P ＜ 0.05).While the corresponding values in HMGB1 monoclonal antibody group were significantly lower than those in ANP group (P ＜0.05).There was a positive linear relationship between serum HMGB1 level and pancreatic pathological scores 24 h after ANP induction (r =0.768,P ＜ 0.05).In addition,the serum levels of AMY,AST,ALT,LDH,BUN,Cr showed a similar trend as that of serum level of HMGB1,and the serum level of HMGB1 was positively associated with serum levels of Cr,BUN and ALT (r =0.824,0.719,0.590,P＜0.05).Conclusions HMGB1 may be a key factor of inflammatory response and organ dysfunction of ANP in mice,and extrinsic supply of its monoclonal antibody may decrease the injuries of pancreas and other organs during ANP. Key words: Pancreatits, acute necrotizing; High mobility group proteins; Antibodies, monoclonal