Hypoxia Activates the PTHrP -MEF2C Pathway to Attenuate Hypertrophy in Mesenchymal Stem Cell Derived Cartilage

Sci Rep. 2019 Sep 16;9(1):13274. doi: 10.1038/s41598-019-49499-x.

Abstract

Articular cartilage lacks an intrinsic repair capacity and due to the ability of mesenchymal stem cells (MSCs) to differentiate into chondrocytes, MSCs have been touted as a cellular source to regenerate damaged cartilage. However, a number of prevailing concerns for such a treatment remain. Generally, administration of MSCs into a cartilage defect results in poor regeneration of the damaged cartilage with the repaired cartilage consisting primarily of fibro-cartilage rather than hyaline cartilage. Methods that improve the chondrogenic potential of transplanted MSCs in vivo may be advantageous. In addition, the proclivity of MSC-derived cartilage to undergo hypertrophic differentiation or form bone in vivo also remains a clinical concern. If MSC-derived cartilage was to undergo hypertrophic differentiation in vivo, this would be deleterious in a clinical setting. This study focuses on establishing a mechanism of action by which hypoxia or low oxygen tension can be used to both enhance chondrogenesis and attenuate hypertrophic differentiation of both MSC and ATDC5 derived chondrocytes. Having elucidated a novel mechanism of action, the subsequent goals of this study were to develop an in vitro culture regime to mimic the beneficial effects of physiological low oxygen tension in a normoxic environment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anaerobiosis / physiology*
  • Animals
  • Cartilage, Articular / cytology*
  • Cell Hypoxia / physiology*
  • Cell Line, Tumor
  • Chondrocytes / cytology
  • Chondrogenesis / physiology*
  • Glycine / analogs & derivatives
  • Glycine / pharmacology
  • Humans
  • Hypertrophy / prevention & control*
  • Isoquinolines / pharmacology
  • MEF2 Transcription Factors / metabolism
  • Mesenchymal Stem Cell Transplantation
  • Mesenchymal Stem Cells / cytology*
  • Mice
  • Parathyroid Hormone-Related Protein / genetics
  • Parathyroid Hormone-Related Protein / metabolism
  • Prolyl-Hydroxylase Inhibitors / pharmacology

Substances

  • Isoquinolines
  • MEF2 Transcription Factors
  • Parathyroid Hormone-Related Protein
  • Prolyl-Hydroxylase Inhibitors
  • Glycine
  • roxadustat