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

The role of TGF-beta signaling pathway in the repairmen of intestinal mucosal injury in the rat model of abdominal compartment syndrome

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、cyclin D、CDK-2表达水平,Western blot检测TGF-β、Smad2、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;4 h和6 h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),cyclin D、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 -β and S - mad？., phosphorylated S - mad2 （ p - Smad2 ） protein. Another five rats were processed in accordance to ACS group, which prepared for hematoxylin eosln （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 - β in 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 -β protein 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.