Mechanically Defined Microenvironment Promotes Stabilization of Microvasculature, Which Correlates with the Enrichment of a Novel Piezo-1+ Population of Circulating CD11b+ /CD115+ Monocytes

Adv Mater. 2019 May;31(21):e1808050. doi: 10.1002/adma.201808050. Epub 2019 Mar 29.

Abstract

Vascularization is a critical step in the restoration of cellular homeostasis. Several strategies including localized growth factor delivery, endothelial progenitor cells, genetically engineered cells, gene therapy, and prevascularized implants have been explored to promote revascularization. But, long-term stabilization of newly induced vessels remains a challenge. It has been shown that fibroblasts and mesenchymal stem cells can stabilize newly induced vessels. However, whether an injected biomaterial alone can serve as an instructive environment for angiogenesis remains to be elucidated. It is reported here that appropriate vascular branching, and long-term stabilization can be promoted simply by implanting a hydrogel with stiffness matching that of fibrin clot. A unique subpopulation of circulating CD11b+ myeloid and CD11b+ /CD115+ monocytes that express the stretch activated cation channel Piezo-1, which is enriched prominently in the clot-like hydrogel, is identified. These findings offer evidence for a mechanobiology paradigm in angiogenesis involving an interplay between mechanosensitive circulating cells and mechanics of tissue microenvironment.

Keywords: Piezo-1; carboxylated agarose; mechanobiology; therapeutic angiogenesis; vessel stabilization.

MeSH terms

  • Animals
  • CD11b Antigen / metabolism*
  • Cell Count
  • Cell Proliferation / drug effects
  • Cellular Microenvironment*
  • Endothelial Cells / metabolism
  • Hydrogels*
  • Ion Channels / metabolism*
  • Leukocytes, Mononuclear / metabolism
  • Mechanical Phenomena*
  • Mice, SCID
  • Microvessels / cytology*
  • Microvessels / metabolism
  • Monocytes / metabolism*
  • Neovascularization, Physiologic
  • Receptor, Macrophage Colony-Stimulating Factor / metabolism*
  • Sepharose / chemistry*
  • Signal Transduction

Substances

  • CD11b Antigen
  • Hydrogels
  • Ion Channels
  • PIEZO1 protein, human
  • Sepharose
  • Receptor, Macrophage Colony-Stimulating Factor