miR-101a and miR-30b contribute to inflammatory cytokine-mediated β-cell dysfunction

Lab Invest. 2015 Dec;95(12):1387-97. doi: 10.1038/labinvest.2015.112. Epub 2015 Sep 14.

Abstract

Inflammatory cytokines have a critical role in the progressive deterioration of pancreatic β-cell function and development of type 1 diabetes. Prolonged exposure of β-cells to inflammatory cytokines results in gene expression modifications, leading to loss of β-cell function. MicroRNAs (miRNAs) are small non-coding RNAs acting as key regulators of gene expression. Here, we demonstrate that miR-101a and miR-30b are key players in cytokine-mediated β-cell dysfunction. We found that IL-1β induces an increase in miR-101a and miR-30b in MIN6 cells, and that the two miRNAs participate in β-cell dysfunction, including decreased insulin content, gene expression, and increased β-cell death. miR-101a and miR-30b reduce proinsulin expression and insulin content by directly targeting the transcriptional factor Neurod1. In addition, β-cell apoptosis mediated by miR-101a and miR-30b is associated with diminished expression level of the antiapoptotic protein Bcl2. Moreover, we show that miR-101a causes an impairment in glucose-induced insulin secretion by decreasing the expression of the transcription factor Onecut2. Taken together, our findings suggest that changes in the levels of miR-101a and miR-30b contribute to cytokine-mediated β-cell dysfunction occurring during the development and progression of type 1 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cytokines
  • Diabetes Mellitus, Type 1 / etiology*
  • HEK293 Cells
  • Homeodomain Proteins / metabolism
  • Humans
  • Insulin / biosynthesis
  • Insulin-Secreting Cells / metabolism*
  • MicroRNAs / metabolism*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Transcription Factors / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Cytokines
  • Homeodomain Proteins
  • Insulin
  • MIRN101 microRNA, human
  • MIRN30b microRNA, human
  • MicroRNAs
  • NEUROD1 protein, human
  • ONECUT2 protein, human
  • Proto-Oncogene Proteins c-bcl-2
  • Transcription Factors