The Wnt modulator sFRP2 enhances mesenchymal stem cell engraftment, granulation tissue formation and myocardial repair

Proc Natl Acad Sci U S A. 2008 Nov 25;105(47):18366-71. doi: 10.1073/pnas.0803437105. Epub 2008 Nov 18.

Abstract

Cell-based therapies, using multipotent mesenchymal stem cells (MSCs) for organ regeneration, are being pursued for cardiac disease, orthopedic injuries and biomaterial fabrication. The molecular pathways that regulate MSC-mediated regeneration or enhance their therapeutic efficacy are, however, poorly understood. We compared MSCs isolated from MRL/MpJ mice, known to demonstrate enhanced regenerative capacity, to those from C57BL/6 (WT) mice. Compared with WT-MSCs, MRL-MSCs demonstrated increased proliferation, in vivo engraftment, experimental granulation tissue reconstitution, and tissue vascularity in a murine model of repair stimulation. The MRL-MSCs also reduced infarct size and improved function in a murine myocardial infarct model compared with WT-MSCs. Genomic and functional analysis indicated a downregulation of the canonical Wnt pathway in MRL-MSCs characterized by significant up-regulation of specific secreted frizzled-related proteins (sFRPs). Specific knockdown of sFRP2 by shRNA in MRL-MSCs decreased their proliferation and their engraftment in and the vascular density of MRL-MSC-generated experimental granulation tissue. These results led us to generate WT-MSCs overexpressing sFRP2 (sFRP2-MSCs) by retroviral transduction. sFRP2-MSCs maintained their ability for multilineage differentiation in vitro and, when implanted in vivo, recapitulated the MRL phenotype. Peri-infarct intramyocardial injection of sFRP2-MSCs resulted in enhanced engraftment, vascular density, reduced infarct size, and increased cardiac function after myocardial injury in mice. These findings implicate sFRP2 as a key molecule for the biogenesis of a superior regenerative phenotype in MSCs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Enzyme-Linked Immunosorbent Assay
  • Heart / physiopathology*
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mesenchymal Stem Cells / cytology*
  • Mice
  • Mice, Inbred C57BL
  • Regeneration / physiology*
  • Wound Healing

Substances

  • Membrane Proteins
  • Sfrp2 protein, mouse