Dicer ablation in osteoblasts by Runx2 driven cre-loxP recombination affects bone integrity, but not glucocorticoid-induced suppression of bone formation

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Peng Liu - , Ulm University, Leibniz Institute on Aging - Fritz Lipmann Institute (Author)
  • Mario Baumgart - , Leibniz Institute on Aging - Fritz Lipmann Institute (Author)
  • Marco Groth - , Leibniz Institute on Aging - Fritz Lipmann Institute (Author)
  • Jürgen Wittmann - , Friedrich-Alexander University Erlangen-Nürnberg (Author)
  • Hans Martin Jäck - , Friedrich-Alexander University Erlangen-Nürnberg (Author)
  • Matthias Platzer - , Leibniz Institute on Aging - Fritz Lipmann Institute (Author)
  • Jan P. Tuckermann - , Ulm University, Leibniz Institute on Aging - Fritz Lipmann Institute (Author)
  • Ulrike Baschant - , Department of Internal Medicine III, Division General Medicine, Department of Internal Medicine III, Ulm University, Leibniz Institute on Aging - Fritz Lipmann Institute (Author)

Abstract

Glucocorticoid-induced osteoporosis (GIO) is one of the major side effects of long-term glucocorticoid (GC) therapy mediated mainly via the suppression of bone formation and osteoblast differentiation independently of GC receptor (GR) dimerization. Since microRNAs play a critical role in osteoblast differentiation processes, we investigated the role of Dicer dependent microRNAs in the GC-induced suppression of osteoblast differentiation. MicroRNA sequencing of dexamethasone-treated wild-type and GR dimer-deficient mesenchymal stromal cells revealed GC-controlled miRNA expression in a GR dimer-dependent and GR dimer-independent manner. To determine the functional relevance of mature miRNAs in GC-induced osteoblast suppression, mice with an osteoblast-specific deletion of Dicer (DicerRunx2Cre) were exposed to glucocorticoids. In vitro generated Dicer-deficient osteoblasts were treated with dexamethasone and analyzed for proliferation, differentiation and mineralization capacity. In vivo, abrogation of Dicer-dependent miRNA biogenesis in osteoblasts led to growth retardation and impaired bone formation. However, subjecting these mice to GIO showed that bone formation was similar reduced in Dicer Runx2Cre mice and littermate control mice upon GC treatment. In line, differentiation of Dicer deficient osteoblasts was suppressed to the same extent as wild type cells by GC treatment. Therefore, Dicer-dependent small RNA biogenesis in osteoblasts plays only a minor role in the pathogenesis of GC-induced inhibition of bone formation.

Details

Original languageEnglish
Article number32112
JournalScientific reports
Volume6
Publication statusPublished - 24 Aug 2016
Peer-reviewedYes

External IDs

PubMed 27554624

Keywords

ASJC Scopus subject areas