Role of high mobility group box1 in hemorrhagic shock-induced acute lung injury

Abstract

Objective To investigate the role of high mobility group box1 (HMGB1) in hemorrhagic shock-induced acute lung injury (ALI) in mouse model. Method Forty-two healthy male BALB/c mice were randomly divided into three groups: control group, hemorrhagic shock (HS) group and anti-HMGB1 treatmeut group. Car-diac puncture, was performed to induce ALI in mice. IL-β and TNF-α in lung tissues were detected by ELISA. Ex-pression of HMGB1 was determined by Westemblot. Myeloperoxidase (MPO) and Evens blue dye (EBD) in lung tissues were measured by colorimetry. Pathology of lung tissue was observed. ANOVA and LSD-t test were used in statistical analysis. Results Pulmonary blood vessel permeability increased 2 h after HS, pathology results re-vealed a diffused inflammatory cell infiltration in mouse lung tissue. Levels of IL-1β and TNF-α in lung tissues sig-nificantly increased at the early stage of ALI (4 h) compared to controls [IL-1β(333.83±31.18) vs. (284.83± 30.49), P =0.014; TNF-α(805.00±114.67) vs. (584.17±181.17), P =0.023]. Significant increase of HMGB1 in lung tissues occurred at the late stage of ALI (16～48 h) [HMGB1/β-actin (0.99±0.16) vs. (0.50 ±0.18), P =0.003]. The levels of MPO and EBD in ALl group significantly increased compared to controls, and reached the peak at4 h and 24 h respectively [MPO (38.33±3.88) vs. (8.00±0.89), P <0.01;EBD (20.05±2.79) vs. (4.63±0.43), P <0.01]. The peak level of MPO and EBD significantly decreased in anti-HMGB1 groups compared to that of ALI group [MPO (25.67±1.63) vs. (38.33±3.88), P < 0.01 ; EBD (5.68±0.53) vs. (20.05±2.79), P <0.001]. The infiltration of neutrophils and the destruction of the pul-monary cell walls ameliorated in anti-HMGB1 groups, especially in mice treated with anti-HMGB1 antihedy for 24 h. Conclusions HMGBI acts as a late pminfiammatory mediator in HS-induced ALI. Blockade of HMGB1 de-creases HS-induced pathophysiologic change of ALI in mice. Key words: High mobility group boxl ; Inflammatory mediator; Acute lung injury; Hemorrhagic shock; Patho-physiologic