Soluble Dietary Fiber Ameliorates Radiation-Induced Intestinal Epithelial-to-Mesenchymal Transition and Fibrosis.

Abstract

BACKGROUND:

Intestinal fibrosis is a late complication of pelvic radiotherapy. Epithelial-to-mesenchymal transition (EMT) plays an important role in tissue fibrosis. The aim of this study was to examine the effect of soluble dietary fiber on radiation-induced intestinal EMT and fibrosis in a mouse model.

MATERIALS AND METHODS:

Apple pectin (4% wt/wt in drinking water) was administered to wild-type and pVillin-Cre-EGFP transgenic mice with intestinal fibrosis induced by a single dose of abdominal irradiation of 10 Gy. The effects of pectin on intestinal EMT and fibrosis, gut microbiota, and short-chain fatty acid (SCFA) concentration were evaluated.

RESULTS:

Intestinal fibrosis in late radiation enteropathy showed increased submucosal thickness and subepithelial collagen deposition. Enhanced green fluorescent protein (EGFP)+/vimentin+ and EGFP+/α-smooth muscle actin (SMA)+ coexpressing cells were most clearly observed at 2 weeks after irradiation and gradually decreased at 4 and 12 weeks. Pectin significantly attenuated the thickness of submucosa and collagen deposition at 12 weeks (24.3 vs 27.6 µm in the pectin + radiation-treated group compared with radiation-alone group, respectively, P < .05; 69.0% vs 57.1%, P < .001) and ameliorated EMT at 2 and 4 weeks. Pectin also modulated the intestinal microbiota composition and increased the luminal SCFA concentration.

CONCLUSION:

The soluble dietary fiber pectin protected the terminal ileum against radiation-induced fibrosis. This effect might be mediated by altered SCFA concentration in the intestinal lumen and reduced EMT in the ileal epithelium.

• Authors: Jianbo Yang, Chao Ding, Xujie Dai, Tengfei Lv, Tingbing Xie, Tenghui Zhang, Wen Gao, Jianfeng Gong, Weiming Zhu, Ning Li, Jieshou Li
• Journal: JPEN. Journal of parenteral and enteral nutrition (JPEN J Parenter Enteral Nutr) Vol. 41 Issue 8 Pg. 1399-1410 (11 2017) ISSN: 1941-2444 [Electronic] United States
• PMID: 27660288 (Publication Type: Journal Article)

Chemical References

• Dietary Fiber
• Fatty Acids, Volatile
• Pectins

Topics

• Animals
• Dietary Fiber (pharmacology)
• Disease Models, Animal
• Epithelial-Mesenchymal Transition (drug effects, radiation effects)
• Fatty Acids, Volatile (metabolism)
• Fibrosis
• Gastrointestinal Microbiome (drug effects)
• Ileum (drug effects, pathology, radiation effects)
• Intestinal Mucosa (drug effects, pathology, radiation effects)
• Intestines (drug effects, pathology, radiation effects)
• Malus (chemistry)
• Mice
• Mice, Inbred C57BL
• Mice, Transgenic
• Pectins (pharmacology)
• Radiotherapy (adverse effects)