Notch/Hes1信号转导通路在重症急性胰腺炎并发急性肺损伤中的作用机制

Mechanism of Notch/Hes1 signal transduction pathway in severe acute pancreatitis associated with acute lung injury

目的探讨重症急性胰腺炎(sever acute pancreatitis,SAP)并发急性肺损伤中Notch/Hes1信号转导通路的活性以及下游白细胞介素(interleukin,IL)-6,肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的变化规律。方法选取健康成年雄性大鼠40只,随机分对照组(10只)和研究组(30只),通过鼻胆管(biliary drainage,BD)针胰胆管逆行注入牛磺胆酸,建立SAP急性肺损伤大鼠模型。研究组在建模后6、12、18 h采用HITACHI 7600型全自动生化分析仪进行操作检测血淀粉酶、血气分析以及肺组织含水率,显微镜下进行胰腺和肺组织病变程度评分。免疫组化法检测肺组织Notch/hes1活性的变化,酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)试剂盒检测血清中IL-6,TNF-α的含量。对照组在术后也进行上述相关指标的检测。结果造模后的研究组大鼠肺损伤程度较对照组逐渐加重,组织含水量及PaCO2逐渐升高(F值分别为100.614和29.843,P值均<0.05)。免疫组织化学检测结果提示Notch/Hes1信号转导通路在肺损伤发展的过程中逐步被激活,至18 h达到峰值。在建模6 h以及18 h后,Notch/Hes1信号转导通路下游细胞因子IL-6、以及TNF-α血清中的含量较对照组显著升高,且在18 h达到最高值[6 h(IL-6,TNF-α):(1125.43±247.45)pg/L比(731.32±125.43)pg/L,(213.45±65.36)pg/L比(125.76±27.68)pg/L;18 h(IL-6,TNF-α):(2147.56±326.54)pg/L比(731.32±125.43)pg/L,(324.47±88.67)pg/L比(125.76±27.68)pg/L],研究组与对照组IL-6、以及TNF-α血清含量的组间差异均具有统计学意义(F值分别为62.790和14.881,P值均<0.05)。Notch/Hes1信号转导通路活性与肺损伤程度呈显著线性正相关(r=0.681,P<0.05)。结论SAP早期肺组织中Notch/Hes1信号传导通路逐步被激活,导致下游细胞因子IL-6以及TNF-α表达上调,与肺组织中的浸润、急性肺损伤的发生和进展密切相关。

Objective To investigate the activity of Notch/Hes1 signal transduction pathway and the changes of downstream cytokines interleukin(IL)-6 and tumor necrosis factor-α(TNF-α)in severe acute pancreatitis complicated with acute lung injury.Methods Forty healthy adult male rats were randomly divided into control group(10)and research group(30).Taurocholic acid was retrogradely injected into the pancreaticobiliary duct through the nasal bile duct(BD)needle to establish a rat model of severe acute pancreatitis and acute lung injury.In research group,the HITACHI 7600 automatic biochemical analyzer was used to detect the blood amylase,blood gas analysis and water content of lung tissueand at 6,12,and 18 h after modeling.At the same time,the pathological changes of pancreas and lung were scored under microscope.The immunohistochemical method was used to detect the change of lung tissue Notch/hes1 activity.Enzyme linked immunosorbent assay(ELISA)kit was used to detect the content of IL-6 and TNF-αin serum.In control group,the above indexes were also detected after operation.Results After modeling,the lung injury of rats in research group gradually increased compared with the control group,and the tissue water content and PaCO2 gradually increased(F values were 100.614 and 29.843 respectively,both P values<0.05).The results of immunohistochemistry showed that Notch/Hes1 signal transduction pathway was gradually activated during the development of lung injury and reaches its peak at 18 h.The levels of IL-6 and TNF-αin serum of Notch/Hes1 signal transduction pathway were significantly higher than those in control group at 6 h and 18 h after modeling,and reached the highest value at 18 h[6 h(IL-6,TNF-α):(1125.43±247.45)pg/L vs(731.32±125.43)pg/L,(213.45±65.36)pg/L vs(125.76±27.68)pg/L;18 h(IL-6,TNF-α):(2147.56±326.54)pg/L vs(731.32±125.43)pg/L,(324.47±88.67)pg/L vs(125.76±27.68)pg/L],and the difference was statistically significant between the control group and research group(F values were 62.790 and 14.881 respectively,both P values<0.05).Notch/Hes1 signal transduction pathway activity was positively correlated with the severity of lung injury(r=0.681,P<0.05).Conclusion In the early stage of severe acute pancreatitis,the Notch/Hes1 signaling pathway was gradually activated,resulting in the up-regulation of the downstream cytokines IL-6 and TNF-α,which was closely related to the infiltration of lung tissue and the occurrence and progress of acute lung injury related.