Manipulation of stem cell fate in vitro using plasmid-based transcription factor over-expression systems
Abstract
Introduction: The ability to switch stem cell differentiation fate in-vitro, is a powerful tool that may allow the
generation of large numbers of cells that may be required in order to develop biologically engineered tissues
and cells required for therapeutic applications such as pharmacological testing of new medications. The
transcription factor (“master switch”) Olig2, alone or in conjunction with Nkx2.2, has been implicated as a
key cell fate decider for emerging neuro-glial precursors derived from both embryonic stem (ES) cells and
from foetal neural stem (FNS) cells.
Methods: The in-vitro system of stem cells devoid of exogenous signaling was developed. Stem cells were
manipulated by pIRES plasmid vector driven, constitutively expressed Olig-2 or Olig-2/Nkx2.2 transcription
factor system introduced into proliferating embryonic or foetal neural stem cells, following a similar
embryological temporal p at t e r ni n g s e q ue nc e s e e n i n - v i v o.
Findings: Successful stem cell fate modification could be achieved in-vitro using the transcription factor
overexpression system. Substantially different cell fates were noted in the presence of Olig-2 alone and in
combination with Nkx2.2, with the achievement of premature glial differentiation.
Conclusion: This method, therefore, may be useful to generate rare live human cells (such as Oligodendroglia
or specialised myocardial cells) in-vitro.