The mechanism of artificial ulcer fibrosis of stenosis after full circumcision of esophageal mucosal dissection based on TGF-β1/Smads/ACTA2 signaling pathway: A porcine model [基于TGF-β1/Smads/ACTA2信号通路探讨猪食管ESD环切术后狭窄模型人工溃疡纤维化的机制]

作者：Zhou X.; Ma D.; Fu J.; Wang Y.-F.; Su S.-C.; Tang Z.-X.; Li X.-Y.; Chen J.; Li Z.

来源：Medical Journal of Chinese People's Liberation Army, 2022, 764-770.

DOI：10.11855/j.issn.0577-7402.2022.08.0764

• endoscopic submucosal dissection
• esophageal stenosis
• fibrosis
• myofibroblasts
• transcription growth factor β1

Objective To investigate the mechanism of artificial ulcer fibrosis of stenosis after full circumcision of esophageal mucosal dissection in porcine model based on TGF-β1/Smads/ACTA2 signaling pathway. Methods A total of eight pigs were randomized into two groups (4 in each group): sham operation group and model group. Animals in the model group received full circumcision of ESD to establish the esophageal artificial ulcer fibrosis model. Three weeks after the surgery, we collected esophageal tissues from animals. We further analyzed the tissues with Hematoxylin-eosin (HE) staining to observe the pathological characteristics of esophageal tissues. The real-time quantitative polymerase chain reaction (qRT-PCR) was employed to detect the mRNA relative expression levels of TGF-β1, Smad2, Smad3, and ACTA2. We then examined the positive expression of CTGF and ACTA2 using immunohistochemistry. Lastly, we detected the protein relative expression levels of TGF-β1, Smad2/3, p-Smad2/3, Smad4, Smad7, CTGF, and ACTA2 using Western blotting. Results Compared with the sham operation group, the fibroblasts in the artificial ulcer site proliferated rapidly with a more transformed myofibroblast phenotype in the model group. In the model group, the qRT-PCR results showed up-regulated mRNA levels of TGF-β1 (P<0.001), Smad3 (P=0.004), and ACTA2 (P=0.001). The results of immunohistochemistry showed that the positive expression of CTGF (P<0.001) and ACTA2 (P<0.001) in the model group were higher than those in the sham operation group. We also observed up-regulated levels of TGF-β1 (P=0.002), Smad2/3 (P=0.003), p-Smad2/3 (P=0.002), Smad4 (P<0.001), Smad7 (P=0.016), CTGF (P<0.001), and ACTA2 in the model group, compared with the sham operation group. Conclusion A porcine model of stenosis after full circumcision of esophageal mucosal dissection was successfully established, and the mechanism may be related to the artificial ulcer fibrosis by TGF-β1/Smads/ACTA2 signaling pathway.