miR-346 functions as a pro-survival factor under ER stress by activating mitophagy

Cancer Lett. 2018 Jan 28:413:69-81. doi: 10.1016/j.canlet.2017.10.030. Epub 2017 Oct 26.

Abstract

Stress in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), which attempts to restore normal function of the ER. Both autophagy and miRNAs have been reported to participate in the process of ER stress, but the relationship between these two factors is still obscure. In this study, we demonstrated that miR-346, which was induced under ER stress, modulated autophagic flux in HeLa cells. By regulating the process of autophagy, miR-346 reduced the ROS level in the cells, thus protecting them from death following ER stress. Furthermore, we demonstrated that GSK3B was the target of miR-346 and participated in ER stress-related autophagy. miR-346 activated autophagy by interrupting the association between BCL2 and BECN1 in a GSK3B-dependent manner. Our findings shed new light on the role of miRNAs during ER stress and suggest a new mechanism for the induction of autophagy under ER stress.

Keywords: Autophagy; ER stress; GSK3B; UPR; miR-346.

MeSH terms

  • Autophagy* / drug effects
  • Beclin-1 / metabolism
  • Brefeldin A / pharmacology
  • Cell Death
  • Dose-Response Relationship, Drug
  • Endoplasmic Reticulum / drug effects
  • Endoplasmic Reticulum / metabolism*
  • Endoplasmic Reticulum / pathology
  • Endoplasmic Reticulum Stress* / drug effects
  • Female
  • Glycogen Synthase Kinase 3 beta / metabolism
  • HeLa Cells
  • Humans
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Mitochondria / drug effects
  • Mitochondria / metabolism*
  • Mitochondria / pathology
  • Mitophagy* / drug effects
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Reactive Oxygen Species / metabolism
  • Signal Transduction
  • Time Factors
  • Ubiquitination
  • Uterine Cervical Neoplasms / metabolism*
  • Uterine Cervical Neoplasms / pathology

Substances

  • BCL2 protein, human
  • BECN1 protein, human
  • Beclin-1
  • MIRN346 microRNA, human
  • MicroRNAs
  • Proto-Oncogene Proteins c-bcl-2
  • Reactive Oxygen Species
  • Brefeldin A
  • GSK3B protein, human
  • Glycogen Synthase Kinase 3 beta