Shen X, Zhao Z, Yang B. MicroRNA-155 promotes apoptosis of colonic smooth muscle cells and aggravates colonic dysmotility by targeting IGF-1.
Exp Ther Med 2020;
19:2725-2732. [PMID:
32256755 DOI:
10.3892/etm.2020.8485]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 06/13/2019] [Indexed: 12/27/2022] Open
Abstract
Colonic dysmotility as a complication of diabetes affects public health; however, the underlying molecular mechanisms have remained elusive. Insulin-like growth factor-1 (IGF-1) was previously demonstrated to prevent apoptosis of colonic smooth muscle cells (SMCs) and alleviate colonic dysmotility in diabetic rats. However, the regulatory mechanisms upstream of IGF-1 in colonic dysmotility have remained to be determined. The present study reports on microRNA-155 (miR-155), initially identified using bioinformatics, as a direct upstream regulator of IGF-1. In colonic SMCs, miR-155 negatively regulated IGF-1 expression at the post-transcriptional level, as identified through ectopic overexpression and knockdown experiments. A luciferase reporter assay further demonstrated that miR-155 inhibits IGF-1 through binding to its 3'-untranslated region. Furthermore, overexpression of miR-155 led to increased apoptosis of colonic SMCs and a decrease in the thickness of colonic smooth muscle tissues of diabetic mice, indicating miR-155 aggravates colonic dysmotility. By contrast, knockdown of miR-155 induced the opposite effect. Overall, the results of the present study suggest a role of miR-155 in colonic dysmotility, thereby providing a novel therapeutic target.
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