Long-term maintenance of mouse embryonic stem cell pluripotency by manipulating integrin signaling within 3D scaffolds without active Stat3

Biomaterials. 2012 Dec;33(35):8934-42. doi: 10.1016/j.biomaterials.2012.08.062. Epub 2012 Sep 19.

Abstract

We engineered an acellular biomimetic microenvironment to regulate stem cell fate and applied it to maintain mouse embryonic stem (ES) cell self-renewal. In the 3D environment formed using hydrogel scaffolds in which specific integrin ligation was provided, Stat3 activation by exogenous leukemia inhibitory factor (LIF) no longer acted as a limiting factor for stem cell self-renewal. Instead, simultaneous stimulation of integrins α(5)β(1), α(v)β(5), α(6)β(1) and α(9)β(1) within the 3D scaffold greatly increased Akt1 and Smad 1/5/8 activation, which resulted in prolonged self-renewal of the ES cells. The ES cells exposed to the combined stimulation of the integrins for 4 wk in LIF-free 3D scaffolds maintained the spherical morphology of cell colonies without losing any activity of pluripotency. In conclusion, cell niche-specific integrin signaling within the 3D environment supported mouse ES cell self-renewal, and the resulting integrin signaling replaced Stat3 with Akt1 and Smad 1/5/8 as critical signals for mouse ES cell self-renewal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Differentiation
  • Cell Proliferation
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • Gene Expression Regulation
  • Hydrogels / chemistry
  • Integrins / metabolism*
  • Leukemia Inhibitory Factor / pharmacology
  • Mice
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / metabolism*
  • Real-Time Polymerase Chain Reaction
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction
  • Tissue Scaffolds / chemistry*

Substances

  • Hydrogels
  • Integrins
  • Leukemia Inhibitory Factor
  • Lif protein, mouse
  • STAT3 Transcription Factor
  • Stat3 protein, mouse