Radiation-induced alterations of osteogenic and chondrogenic differentiation of human mesenchymal stem cells

PLoS One. 2015 Apr 2;10(3):e0119334. doi: 10.1371/journal.pone.0119334. eCollection 2015.

Abstract

While human mesenchymal stem cells (hMSCs), either in the bone marrow or in tumour microenvironment could be targeted by radiotherapy, their response is poorly understood. The oxic effects on radiosensitivity, cell cycle progression are largely unknown, and the radiation effects on hMSCs differentiation capacities remained unexplored. Here we analysed hMSCs viability and cell cycle progression in 21% O2 and 3% O2 conditions after medical X-rays irradiation. Differentiation towards osteogenesis and chondrogenesis after irradiation was evaluated through an analysis of differentiation specific genes. Finally, a 3D culture model in hypoxia was used to evaluate chondrogenesis in conditions mimicking the natural hMSCs microenvironment. The hMSCs radiosensitivity was not affected by O2 tension. A decreased number of cells in S phase and an increase in G2/M were observed in both O2 tensions after 16 hours but hMSCs released from the G2/M arrest and proliferated at day 7. Osteogenesis was increased after irradiation with an enhancement of mRNA expression of specific osteogenic genes (alkaline phosphatase, osteopontin). Osteoblastic differentiation was altered since matrix deposition was impaired with a decreased expression of collagen I, probably through an increase of its degradation by MMP-3. After induction in monolayers, chondrogenesis was altered after irradiation with an increase in COL1A1 and a decrease in both SOX9 and ACAN mRNA expression. After induction in a 3D culture in hypoxia, chondrogenesis was altered after irradiation with a decrease in COL2A1, ACAN and SOX9 mRNA amounts associated with a RUNX2 increase. Together with collagens I and II proteins decrease, associated to a MMP-13 expression increase, these data show a radiation-induced impairment of chondrogenesis. Finally, a radiation-induced impairment of both osteogenesis and chondrogenesis was characterised by a matrix composition alteration, through inhibition of synthesis and/or increased degradation. Alteration of osteogenesis and chondrogenesis in hMSCs could potentially explain bone/joints defects observed after radiotherapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cell Cycle / radiation effects
  • Cell Differentiation / radiation effects*
  • Cell Line
  • Cell Proliferation / radiation effects
  • Cell Survival / radiation effects
  • Cellular Senescence / radiation effects
  • Chondrogenesis*
  • Collagen / genetics
  • Collagen / metabolism
  • G2 Phase Cell Cycle Checkpoints / radiation effects
  • Gene Expression
  • Humans
  • Male
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism
  • Mesenchymal Stem Cells / radiation effects*
  • Osteoblasts / cytology
  • Osteoblasts / metabolism
  • Osteoblasts / radiation effects
  • Osteogenesis*
  • Oxygen Consumption
  • X-Rays
  • Young Adult

Substances

  • Collagen

Grants and funding

This project was funded by the Regional Council of Lower-Normandy (France, Programme Emergence to SCH), another Programme Emergence to Christophe Denoyelle (BioTICLA, Caen, France) and PG, the French Ministry of Research and the French National Agency of Research (ANR, PROMOCART grant) to PG. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.