eLife (Dec 2018)

miR-34a is a microRNA safeguard for Citrobacter-induced inflammatory colon oncogenesis

  • Lihua Wang,
  • Ergang Wang,
  • Yi Wang,
  • Robert Mines,
  • Kun Xiang,
  • Zhiguo Sun,
  • Gaiting Zhou,
  • Kai-Yuan Chen,
  • Nikolai Rakhilin,
  • Shanshan Chao,
  • Gaoqi Ye,
  • Zhenzhen Wu,
  • Huiwen Yan,
  • Hong Shen,
  • Jeffrey Everitt,
  • Pengcheng Bu,
  • Xiling Shen

DOI
https://doi.org/10.7554/eLife.39479
Journal volume & issue
Vol. 7

Abstract

Read online

Inflammation often induces regeneration to repair the tissue damage. However, chronic inflammation can transform temporary hyperplasia into a fertile ground for tumorigenesis. Here, we demonstrate that the microRNA miR-34a acts as a central safeguard to protect the inflammatory stem cell niche and reparative regeneration. Although playing little role in regular homeostasis, miR-34a deficiency leads to colon tumorigenesis after Citrobacter rodentium infection. miR-34a targets both immune and epithelial cells to restrain inflammation-induced stem cell proliferation. miR-34a targets Interleukin six receptor (IL-6R) and Interleukin 23 receptor (IL-23R) to suppress T helper 17 (Th17) cell differentiation and expansion, targets chemokine CCL22 to hinder Th17 cell recruitment to the colon epithelium, and targets an orphan receptor Interleukin 17 receptor D (IL-17RD) to inhibit IL-17-induced stem cell proliferation. Our study highlights the importance of microRNAs in protecting the stem cell niche during inflammation despite their lack of function in regular tissue homeostasis.

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