转化生长因子-β通路在腹腔间隔室综合征大鼠模型肠黏膜损伤修复中的作用

摘要

目的 探讨转化生长因子-β(TGF-β)信号通路在腹腔间隔室综合征(ACS)大鼠模型肠黏膜损伤修复中的作用.方法 SD大鼠30只,随机分为实验组(ACS)组 、对照组(sham组).实验组模型建立成功后再以相应腹内压(20 mmHg)维持0.5、2、4、6 h 4个时间点随机分为4个组,每组6只.每组实验末期,正中剖腹,找到回盲部,切取近端回肠组织,Q-PCR检测TGF-β、cyclinD、CDK-2表达水平,Western blot检测TGF-β、S-mad2、磷酸化S-mad2(p-Smad2)蛋白表达水平;此外,如上相同分组共5只大鼠,处理同上,常规HE染色.结果 sham组回肠黏膜上皮细胞结构完整,排列相对整齐;ACS组0.5 h肠黏膜损伤相对较轻,绒毛部分脱落;2 h时肠黏膜明显水肿,肠黏膜上皮间隙增宽,黏膜上皮细胞变性及坏死;4h和6h肠绒毛完整性被破坏,绒毛顶端脱落,广泛糜烂,中性粒细胞浸润.ACS组0.5、2、4、6 h组TGF-β表达量较sham组表达降低(P<0.05),cyclinD、CDK-2表达量较Sham组升高,差异有统计学意义(P<0.05).ACS组中TGF-β、p-Smad2蛋白表达较sham组降低,差异有统计学意义(P<0.05),S-mad2蛋白表达在sham组和ACS组中差异无统计学意义(P>0.05).结论ACS形成后会造成肠黏膜损伤,肠黏膜损+伤后TGF-β信号通路启动一系列分子反应,促进肠黏膜损伤的修复.%Objective To investigate the role of transforming growth factor -beta ( TGF-β) signaling pathway in the repairmen of intestinal mucosal injury in the rat model of abdominal compartment syndrome (ACS).Methods Thirty Sprague-Dawley male rats were randomly divided into two groups that included experimental group ( ACS group, n=24) and sham group (n=6).After the model of ACS was successfully established , the rats were divided into four subgroups as the corresponding intra -abdominal pressure (IAP) were maintained for 0.5, 2, 4, or 6 h, respectively.At the end of each operation , the proximal ileum was collected for Q -PCR detection to verify the expression of TGF -beta, cyclinD and CDK-2;and Western blot detection to verify the expression of TGF -βand S-mad2, phosphorylated S -mad2 (p-Smad2) protein.Another five rats were processed in accordance to ACS group , which prepared for hematoxylin eosin (HE) staining.Results The structure of ileal mucosal epithelial cells was relatively neat in sham group .The in-testinal mucosal injury was relatively light in 0.5 h subgroup.In 2 h subgroup, obvious hydroptic intestinal mucosa , wid-ened intestinal mucosal epithelial gap , and necrotic mucosal epithelial cells were observed .In addition, the integrity of in-testinal villus was damaged , with villus shedding and infiltration of neutrophils in 4 h and 6 h subgroups .The expression of gene TGF-βin ACS group was significantly lower than sham group (P<0.05), while the expression of cyclinD and CDK-2 was significantly higher than sham group (P<0.05).The expression of TGF-βprotein and p-Smad2 protein was significantly lower than that in sham group (P<0.05).However, the expression of S-mad2 protein in sham group showed no significant difference when compared with ACS group .Conclusion These results supports that ACS could damage intestinal mucosa , and then TGF -βsignaling pathway could activate a series of molecular reaction which pro -motes the repairmen of intestinal mucosal injury .