p38MAPK对小儿急性肠梗阻肠坏死Occludin表达的影响及临床意义

目的 探讨p38MAPK信号通路在小儿急性肠梗阻肠坏死中对紧密连接蛋白Occludin表达的影响及临床意义.方法 选取2013年12月至2014年12月急诊入院的急性肠梗阻合并肠坏死患儿38例,术后病理切片均证实肠坏死为病变组;20例消化道畸形(梅克尔憩室、肠重复畸形无并发症)患儿为正常对照组.采用Western Blot检测切除肠管p38MAPK,p-p38MAPK含量;免疫组化法检测肠上皮间紧密连接蛋白Occludin表达(OD值);TUNEL法检测肠上皮细胞凋亡指数(AI);ELISA法检测术前、术后7d血清TNF-α含量;将各检测指标分别与Occludin蛋白OD值行相关性分析.结果 p38MAPK相对含量,病变组1.69±0.59,对照组1.89±0.63,P＞0.05;p-p38MAPK相对含量病变组1.15±0.14,对照组0.66±0.07;AI病变组52.10±1.7,对照组23.03±7.4;术前血清TNF-α含量病变组98.38±18.7,对照组50.02±11.1;Ocludin蛋白OD值病变组3.44±2.8,对照组8.66±4.6,P值均＜0.01.p-p38MAPK相对含量、AI、术前血清TNF-α含量分别与肠上皮细胞Occludin OD值相关性分析示:r=-0.616、r=-0.316、r=-0.562,三者间P＜0.01.结论 小儿急性肠梗阻肠坏死由于肠绞窄缺血缺氧p38MAPK信号通路被激活,启动细胞凋亡和TNF-α大量释放,使紧密连接Occludin蛋白表达下降,最终肠黏膜屏障破坏可能引发细菌移位.

Effect and clinical significance of p38MAPK signaling pathway on the expression of tight junction protein Occludin in acute intestinal obstruction with necrosis in children

Objective To explore the effect and clinical significance of p38MAPK signaling pathway on the expression of tight junction protein Occludin in acute intestinal obstruction with necrosis in children.Methods A total of 38 hospitalized children of acute intestinal obstruction with necrosis were selected from December 2013 to December 2014 as lesion group.And another 20 cases of digestive tract malformation (Meckeks diverticulum & intestinal duplication without complications) as normal group.Western blot was used for detecting the intestinal contents of p38MAPK and p-p38MAPK.And immunohistochemistry was employed for detecting the intestinal expression of Occludin and determining its value of optical density (OD).Apoptotic index (AI) of intestinal epithelial cells was measured by TdT-mediated dUTP nick end labeling (TUNEL).The serum contents of tumor necrosis factor-alpha (TNF-a) at Day 7 pre and post-operation were detected by enzyme-linked immunosorbent assay (ELISA).Correlation analysis was conducted between each index and Occludin OD level.Results Relative content of p38MAPK:1.69 ± 0.59 in lesion group versus 1.89 ± 0.63 in normal group (P＞0.05);relative content of p-p38MAPK:1.15 ± 0.14 in lesion group versus 0.66 ± 0.07 in normal group;AI:52.10 ± 1.7 in lesion group versus 23.03 ± 7.4 in normal group;preoperative content of TNF-a:98.38 ± 18.7 in lesion group versus 50.02 ± 11.1 in normal group;OD value of Occludin:3.44 ± 2.8 in lesion group versus 8.66 ± 4.6 in normal group (all P＜ 0.01).Correlation analysis between relative content of p-p38MAPK,AI and preoperative content of TNF-α and OD value of Occludin:r =-0.616,r =-0.316 and r =-0.562 (all P ＜ 0.01).Conclusions In pediatric acute intestinal obstruction with necrosis,strangulated intestinal ischemia and hypoxia may activate p38MAPK signing pathway,initiate apoptosis and release TNF-α so that a down-regulation of Occludin impairs intestinal mucosal barrier and leads to bacterial transolcation.