MiR-34a promotes Fas-mediated cartilage endplate chondrocyte apoptosis by targeting Bcl-2

Mol Cell Biochem. 2015 Aug;406(1-2):21-30. doi: 10.1007/s11010-015-2420-4. Epub 2015 Apr 25.

Abstract

Apoptosis of cartilage endplate (CEP) chondrocytes is associated with the pathogenesis of intervertebral disk degeneration (IDD). Recent studies have shown that miR-34a is crucially involved in chondrocyte apoptosis during osteoarthritic cartilage. Here, we investigated the involvement of miR-34a in CEP chondrocyte apoptosis in IDD. In human degenerated CEP chondrocytes, miRNA (miR)-34a was markedly elevated in association with increased apoptosis. Bioinformatics target prediction identified Bcl-2 as a putative target of miR-34a. Furthermore, miR-34a inhibited Bcl-2 expression by directly targeting their 3'-untranslated regions, and this inhibition was abolished by mutation of the miR-34a binding sites. In vitro, knockdown of miR-34a in human endplate chondrocytes resulted in overexpression of Bcl-2, whereas upregulation of miR-34a led to repression of Bcl-2. Fas-mediated apoptosis was decreased when antagonizing miR-34a with locked nucleotide analog-miR-34a in human endplate chondrocytes. Taken together, our results demonstrate that upregulated miR-34a potentiates Fas-mediated endplate chondrocyte apoptosis, which is associated with IDD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Apoptosis*
  • Base Sequence
  • Binding Sites
  • Cartilage / pathology
  • Cells, Cultured
  • Chondrocytes / physiology*
  • Female
  • Humans
  • Intervertebral Disc Degeneration / metabolism
  • Intervertebral Disc Degeneration / pathology
  • Male
  • MicroRNAs / genetics*
  • Middle Aged
  • Proto-Oncogene Proteins c-bcl-2 / genetics*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • RNA Interference
  • fas Receptor / metabolism*

Substances

  • BCL2 protein, human
  • MIRN34 microRNA, human
  • MicroRNAs
  • Proto-Oncogene Proteins c-bcl-2
  • fas Receptor