MicroRNA-29b ameliorates ileocolonic anastomosis fibrosis in interleukin-10-knockout mice via targeting heat shock protein 47

Abstract

Objective The purpose of this study is to investigate the effect of microRNA-29b (miR-29b) and heat shock protein 47 (HSP47) in the fibrosis of ileocolonic anastomosis of interleukin (IL)-10 knockout (IL-10KO) mice undergoing ileocecal resection and anastomosis (ICA). Methods A new model of ICA in IL-10KO mice was used to investigate the postsurgical fibrosis of anastomosis. 12 IL-10KO mice were randomized to IL-10KO and IL-10KO-ICA group. Aged-matched wild-type (WT) mice were assigned to WT and WT-ICA group. AgomiR-29b was used to up-regulate the expression of miR-29b. Crohn’s disease activity index (CDAI) was employed to evaluate the general condition of mice 8 weeks after the beginning of the experiment. Effects of miR-29b treatment on ileocolonic anastomosis were determined by histopathological and Western blotting analysis. Levels of miR-29b and HSP47 was measured by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR) and Western blotting. Western blotting was also used to assess the level of Collagen-Ⅰ (Col-Ⅰ) and Collagen-Ⅲ (Col-Ⅲ). Results Mean CDAI (WT group: 0.833±0.753 vs. WT-ICA group: 3.167±1.169 vs. IL-10KO group: 2.333±1.033 vs. IL-10KO-ICA group: 8.833±1.471, all P=0.000 when compare IL-10-ICA group to other groups) and fibrosis score (WT group: 0.333±0.516 vs. WT-ICA group: 0.833±0.408 vs. IL-10KO group: 1.667±0.817 vs. IL-10KO-ICA group: 4.000±0.632, all P=0.000, when compare IL-10-ICA group to other groups) of mice in IL-10KO-ICA group was significantly upregulated compared with other groups 8 weeks after the beginning of the experiment. Western blotting showed that the production of HSP47 was significantly inhibited by overexpression of miR-29b (A value: agomiR-NC group: 0.631±0.084 vs. agomiR-29b group: 0.268±0.069, P=0.000). Futhermore, overexpression of miR-29b significantly reduced the level of Col-Ⅰ (A value: agomiR-NC group: 0.588±0.900 vs. agomiR-29b group: 0.380±0.150, P=0.037) and Col-Ⅲ (A value: agomiR-NC group: 0.610±0.130 vs. agomiR-29b group: 0.412±0.094, P=0.017) of anastomosis of mice in IL-10KO-ICA group. Conclusion Upregulation of miR-29b may be a therapeutic strategy against postoperative anastomotic fibrosis in CD patients throughinhibition of HSP47. Key words: Crohn’s disease; Fibrosis; MicroRNA-29b; Heat shock protein 47