MiR-106b fine tunes ATG16L1 expression and autophagic activity in intestinal epithelial HCT116 cells

Zili Zhai, Feng Wu, Alice Y. Chuang, John H. Kwon

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

Background: The microRNAs (miRNAs) regulate gene expression at the posttranscriptional level. ATG16L1, an essential component for autophagy and a risk gene for Crohn's disease, contains two binding sites in the 3'UTR for miR-17 family, including miRs-20a, -93, -106a, and -106b. The purpose of this study was to assess the effects of these miRNAs on ATG16L1 expression and autophagic activity in HCT116 cells. Methods: The functional binding sites in the ATG16L1 3'UTR were evaluated by transfection of pMIR-GLO vectors bearing the wild type or mutant 3'UTR into cells for luciferase reporter assay. The miRNA regulation of ATG16L1 expression was determined by quantitative real-time polymerase chain reaction and Western blot. The miRNA regulation of autophagic activity was evaluated by examining LC3II formation using Western blot and confocal imaging. Results: Both miR-106a and miR-106b mimics inhibited starvation-induced autophagy. The miR-106b mimic reduced ATG16L1 protein expression. Luciferase reporter assays showed that mutating the binding sequence at the positions 1036 to 1042 abrogated miR-106b regulation of ATG16L1 3'UTR luciferase activity. In addition, miR-106a and miR-106b overexpression inhibited the expression of several other autophagy genes, including ATG12. Conclusions: miR-106b targets ATG16L1 and modulates autophagy, partially through the binding site at the 3' end of ATG16L1 3'UTR. miR-106a regulates autophagy, possibly irrelevant to ATG16L1 regulation. Both miR-106a and miR-106b regulate multiple autophagy genes so that they may play an integral role in fine-tuning autophagy.

Original languageEnglish (US)
Pages (from-to)2295-2301
Number of pages7
JournalInflammatory Bowel Diseases
Volume19
Issue number11
DOIs
StatePublished - Oct 1 2013

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Keywords

  • ATG16L1
  • Autophagy
  • Crohn's disease
  • MicroRNA
  • MiR-106b

ASJC Scopus subject areas

  • Immunology and Allergy
  • Gastroenterology

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