Effect of serum high mobility group box 1 protein on immune function and autophagy level of myocardial cells in rats with sepsis.

OBJECTIVE To investigate the effects of serum high mobility group box 1 protein (HMGB1) on immune function and autophagy level of myocardial cells in rats with sepsis. MATERIALS AND METHODS Cecal ligation and perforation (CLP) was used to establish rat sepsis models. A total of 60 SD rats were selected and randomly divided into blank control group (BCG, n=20), sham group (SG, n=20) and cecal ligation and perforation group (CLPG, n=20). Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum HMGB1 level in sepsis rats. The expression levels of inflammatory factors in rats were detected, and the ratio of CD4+/CD8+ T cells was detected by flow cytometry. Western blot was used to detect the expression of autophagy-related protein microtubule-related protein 1 light chain 3 (LC3), Beclin-1 and apoptosis-related protein B lymphoblastoma-2 (Bcl-2), and cTnT protein, respectively. RESULTS The level of serum HMGB1 in the CLPG was significantly higher than that in the BCG and the SG (p<0.05). Compared with BCG and the SG, the CLPG had lower peripheral blood T lymphocyte proliferation response, lower IL-6 and IL-10 levels, and lower CD4+/CD8+T lymphocyte ratio (p<0.05). Bcl-2 and cTnT in the CLPG and SG were higher than those in the BCG. LC3-11 and Beclin-1 expression in the CLPG were higher than those in the BCG and SG (p<0.05). After HMGB1 interference in the CLPG, CD4+/CD8+T and Bcl-2 were significantly increased, while the other indicators were significantly decreased (p<0.05). The level of serum HMGB1 is directly related to the severity of sepsis. CONCLUSIONS The increase of serum HMGB1 level in sepsis has a significant impact on cellular immune dysfunction. Sepsis can effectively activate myocardial autophagy, and the level of autophagy shows an increasing trend.