MicroRNA-200b/c-3p regulate epithelial plasticity and inhibit cutaneous wound healing by modulating TGF-β-mediated RAC1 signaling

Cell Death Dis. 2020 Oct 29;11(10):931. doi: 10.1038/s41419-020-03132-2.

Abstract

Cutaneous wound healing is pivotal for human skin to regain barrier function against pathogens. MicroRNAs (miRNAs) have been found to play regulatory roles in wound healing. However, the mechanism of miRNA regulation remains largely unknown. In this study, we focused on microRNA-200b/c-3p (miR-200b/c-3p) whose expression was abundant in intact epidermis, but dramatically decreased in skin wounds. In silico prediction identified RAC1 as a potential miR-200b/c-3p target. Luciferase reporter assay confirmed that miR-200b/c-p repressed RAC1 by direct targeting to its mRNA 3'UTR. Consistently, miR-200b/c-3p expression was discordantly related to RAC1 protein level during wound healing. Forced miR-200b/c-3p expression repressed RAC1 and inhibited keratinocyte migration as well as re-epithelialization in a mouse back skin full-thickness wound healing model. Mechanistically, miR-200b/c-3p modulated RAC1 to inhibit cell migration by repressing lamellipodia formation and intercellular adhesion dissolution in keratinocytes. Furthermore, we found that TGF-β1, which was highly expressed in skin wounds, contributed to the downregulation of miR-200b/c-3p in wound edge keratinocytes. Taken together, miR-200b/c-3p-mediated RAC1 repression inhibited keratinocyte migration to delay re-epithelialization. TGF-β1 induction attenuated miR-200b/c-3p regulation of RAC1 signaling in cutaneous wounds and the repression of miR-200b/c-3p accelerated keratinocyte migration to promote wound healing. Our data provide new insight into how miR-200b/c-3p affects keratinocyte migration and highlight the potential of miR-200b/c-3p targeting for accelerating wound healing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cell Plasticity / drug effects
  • Cell Plasticity / physiology
  • Female
  • HEK293 Cells
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / metabolism
  • Mice
  • Mice, Inbred C57BL
  • MicroRNAs / metabolism*
  • Neuropeptides / metabolism*
  • Signal Transduction / drug effects
  • Transforming Growth Factor beta1 / pharmacology*
  • Wound Healing / drug effects
  • Wound Healing / physiology*
  • rac1 GTP-Binding Protein / metabolism*

Substances

  • MIRN200 microRNA, human
  • MicroRNAs
  • Mirn200 microRNA, mouse
  • Neuropeptides
  • RAC1 protein, human
  • Rac1 protein, mouse
  • Transforming Growth Factor beta1
  • rac1 GTP-Binding Protein