Exploration on the mechanism of pioglitazone in alleviating severe acute pancreatitis induced lung injury by inhibiting the expression of TLR2 and TLR4's mRNA in lung tissue / 中华急诊医学杂志

ABSTRACT

Objective:To explore the mechanism of pioglitazone in reducing lung injury induced by acute pancreatitis.Methods:Thirty healthy male SD rats were randomly(random number) divided into the sham operation group, model group and pioglitazone group, with 10 rats in each group. After anesthesia, the rats in the sham operation group were injected with normal saline retrogradely through the pancreaticobiliary duct. In the model group, after anesthesia, the rats were retrogradely injected with sodium taurocholate into the pancreaticobiliary duct to construct the lung injury model of severe acute pancreatitis. In the pioglitazone group, the model was established after intraperitoneal injection of pioglitazone. Six rats in each group were randomly selected and killed 12 h after operation, and then lung tissue and venous blood were collected. The levels of serum amylase and TNF-α and NO in lung tissue homogenate were detected and compared among the three groups; the expression of TLR2 mRNA and TLR4 mRNA in lung tissue was detected by RT-PCR and compared among the three groups; the lung tissue pathological injury score and lung leakage index were calculated and compared among the three groups. The correlation of TLR2 and TLR4’s mRNA expression with lung tissue pathological injury score and lung leakage index was analyzed.Results:The levels of serum amylase and the levels of TNF-α and NO in lung tissue homogenate in the model group were significantly higher than those in the sham operation group, and the above indexes in the pioglitazone group were significantly lower than those in the model group ( P<0.05). The expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue, the lung tissue pathological injury score and lung leakage index in the model group were significantly higher than those in the sham operation group, and the above indexes in the pioglitazone group were significantly lower than those in the model group ( P<0.05). Spearman correlation analysis showed that the expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue were significantly positively correlated with the lung tissue pathological injury score ( rs=0.959, P<0.001; rs=0.924, P<0.001). Pearson correlation analysis showed that the expression levels of TLR2 mRNA and TLR4 mRNA in lung tissue were significantly positively correlated with the lung leakage index ( r=0.957, P<0.001; r=0.958, P<0.001). Conclusions:Pioglitazone may reduce the severity of severe acute pancreatitis induced lung injury by inhibiting the expression of TLR2 mRNA and TLR4 mRNA in lung tissue.