Expression Of High Mobility Group Protein Box-1 MRNA In Myocardium And Serum Of Rats With Sepsis

Objective:To investigate the level of the high mobility group protein box-1(HMGB1) in the myocardium and serum of rats with sepsis and provide the basic information for the further study of the role of the HMGB1 in the sepsis myocardial depression.Methods:Eighty adult male Wistar rats were selected as the research objects. They were randomly divided into 2hour,6hour,12hour,24hour,48 hour and 72hour groups, and a normal group, a sham group, with 10 rats in each group. Cecal ligation puncture (CLP) was used to establish the sepsis model. The normal group as the parallel control group, the sham group rats were made the switch abdominal surgeries. The serum was taken to assay the level of HMGB1 through the technique of enzyme-linked immunosorbent assay. The cardiac muscles were taken to assay the mRNA expressions of the HMGB1 through the technique of Real Time PCR, and the immunohistochemistry was applied to detect the expression of the HMGB1 in the myocardial tissue.Results:The average levels of the high mobility group protein box-1 of the serum of the sepsis rats from the CLP2h group to the CLP72h group are 61.78±12.19pg/ml,68.84±8.80pg/ml,79.70±8.79pg/ml,190.65±7.21pg/ml,433.39±48.2 4pg/ml and 384.16±26.81pg/ml,the normal group is 49.53±10.57pg/ml,the sham group is 54.41±7.50 pg/ml. The average level of the HMGB1 of the CLP group rats is higher significantly than the other two groups. The CLP48h group is the highest, and the CLP72h group is still higher than the other groups except the CLP48h group.The average expression of the HMGB 1 mRNA of the cardiac muscle of rats with sepsis in the normal group is 1,in the sham group is 0.92±0.17,from the CLP2h group to the CLP72h group are1.06±0.06,1.20±0.43,1.43±0.34,2.74±0.28,4.69±0.29 and 3.32±0.12,which is significantly higher than both the normal group and the sham group(p<0.05).It is indicated that the expression of the HMGB1mRNA of the cardiac muscle of rats with sepsis is increased,which are remarkable higher in the 24hour and 72hour groups, and the highest in the group of 48 hour(p<0.05).Myocardium from the CLP groups showed loose alignment with vacuolization, interstitial swelling, congestion and infiltration of inflammation cells under light microscope and the HMGB1 is positive in the cytoplasm of myocardial cells while compared with both of normal group and sham group, especially in the CLP48h and CLP72h groups. Conclusions:The expressions of the HMGB1 in the cardiac muscle and serum of the CLP groups are increased significantly, especially the rats of the CLP48h group. This may be relate to the sepsis myocardial depression in some extent, it is essential to carry on the further researches of the specific mechanisms, what is more, it is the time that 24-72 hours after establishing the sepsis model to explore the role of the HMGB1 in sepsis induced myocardial dysfunction.