术后肠梗阻炎症进展中NR4A1、MAPK及IL-6表达变化的分析

Expression of NR4A1,MAPK and IL-6 in Postoperative ILeus Inflammatory Process

目的探讨孤核受体NR4A1对大鼠术后肠梗阻(POI)炎症的调控作用。方法18只Sprague-Dawley(SD)大鼠随机分为假手术组、模型组(POI模型)、激动剂组(POI模型+CytosporoneB),每组各6只。激动剂组术前1 h腹腔注射CytosporoneB(13 mg/kg),假手术组和模型组术前1 h腹腔注射同等剂量磷酸盐缓冲液。饲养48 h后用墨汁灌胃,30 min后麻醉处死大鼠,取血液和小肠组织。采用免疫组织化学方法测定肠组织NR4A1表达,光镜下观察肠组织病理形态学改变,测量小肠推进率,TUNEL法检测肠组织细胞凋亡,免疫荧光实验检测肠组织丝裂原活化蛋白激酶(MAPK)14和MAPK3的表达,ELISA法检测血浆和肠组织中白细胞介素6(IL-6)的含量。结果与假手术组比较,模型组NR4A1表达明显降低,小肠推进率下降(P<0.0001),肠组织炎症加重,细胞凋亡明显升高(P<0.01),MAPK14和MAPK3显著上调(P<0.0001),血浆和肠组织的IL-6水平升高(P<0.0001)。与模型组比较,激动剂组中NR4A1表达明显升高,小肠推进率升高(P<0.0001),肠组织炎症明显减轻,细胞凋亡明显降低(P<0.01),MAPK14和MAPK3表达显著下调(P<0.0001),血浆和肠组织的IL-6水平降低(P<0.001或P<0.0001)。结论激活NR4A1表达可减轻大鼠POI的炎症反应和梗阻症状,其机制可能与通过抑制MAPK信号通路有关。

Objective To investigate the regulatory effects of NR4A1 on postoperative ileus inflammation in rats.Methods Eighteen spraguedawley(SD)rats were divided into three groups(n=6 each group)using a random table method:sham group,model group(POI model),and stimulator group(POI model+CytosporoneB).The POI model was established by operation in rats.At 1 h before operation,the rats were treated with stimulator CytosporoneB(13 mg/kg),or the same dose of phosphate buffer solution,separately.The stomach was inked after at 48 h.After 30 min,all rats were sacrificed to harvest intestines tissues and blood for index detection.The expression of NR4A1 in intestinal tissue was measured using an immunohistochemistry technology.The histopathological changes of intestinal tissue was observed under light microscope.The intestinal propulsion rate was measured using a ruler.The expression of MAPK14 and MAPK3 in intestinal tissue were measured using an immunofluorescence technology.The apoptosis of intestinal tissue was measured using a TUNEL.The interleukin-6(IL-6)level of plasma and intestinal tissue were measured using an enzyme-linkedimmunosorbent assay(ELISA).Results Compared to the sham group,the expression of NR4A1 and small intestine propulsion rate in the model group were significantly decreased.However,the following indexes in the model group were significantly increased:The inflammation of intestinal tissue,the expression of MAPK14 and MAPK3(P<0.0001),apoptosis(P<0.01),IL-6 level of plasma and intestinal tissue(P<0.0001).Compared to the model group,the expression of NR4A1 and small intestine propulsion rate in the stimulator group were significantly increased.The following indexes in the stimulator group were significantly decreased:The inflammation of intestinal tissue,the expression of MAPK14 and MAPK3(P<0.0001),apoptosis(P<0.01),IL-6 level of plasma and intestinal tissue(P<0.001 or P<0.0001).Conclusion Activation of NR4A1 can reduce the inflammatory response and obstructive symptoms of POI in rats.The mechanism maybe related to the inhibition of MAPK signaling pathway.