ECM microenvironment unlocks brown adipogenic potential of adult human bone marrow-derived MSCs

Sci Rep. 2016 Feb 17:6:21173. doi: 10.1038/srep21173.

Abstract

Key to realizing the diagnostic and therapeutic potential of human brown/brite adipocytes is the identification of a renewable, easily accessible and safe tissue source of progenitor cells, and an efficacious in vitro differentiation protocol. We show that macromolecular crowding (MMC) facilitates brown adipocyte differentiation in adult human bone marrow mesenchymal stem cells (bmMSCs), as evidenced by substantially upregulating uncoupling protein 1 (UCP1) and uncoupled respiration. Moreover, MMC also induced 'browning' in bmMSC-derived white adipocytes. Mechanistically, MMC creates a 3D extracellular matrix architecture enshrouding maturing adipocytes in a collagen IV cocoon that is engaged by paxillin-positive focal adhesions also at the apical side of cells, without contact to the stiff support structure. This leads to an enhanced matrix-cell signaling, reflected by increased phosphorylation of ATF2, a key transcription factor in UCP1 regulation. Thus, tuning the dimensionality of the microenvironment in vitro can unlock a strong brown potential dormant in bone marrow.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activating Transcription Factor 2 / metabolism
  • Adipocytes, Brown / cytology
  • Adipocytes, Brown / metabolism
  • Adipocytes, White / cytology
  • Adipocytes, White / metabolism
  • Adipogenesis*
  • Cell Differentiation*
  • Cellular Microenvironment*
  • Extracellular Matrix / metabolism*
  • Gene Expression
  • Humans
  • Mesenchymal Stem Cells / cytology*
  • Mesenchymal Stem Cells / metabolism*
  • Models, Biological
  • Phenotype
  • Subcutaneous Fat, Abdominal / cytology
  • Subcutaneous Fat, Abdominal / metabolism
  • Uncoupling Protein 1 / genetics
  • Uncoupling Protein 1 / metabolism

Substances

  • Activating Transcription Factor 2
  • Uncoupling Protein 1