Regulation of Boundary Cap Neural Crest Stem Cell Differentiation After Transplantation

Abstract

Success of cell replacement therapies for neurological disorders will depend largely on the optimization of strategies to enhance viability and control the developmental fate of stem cells after transplantation. Once transplanted, stem/progenitor cells display a tendency to maintain an undifferentiated phenotype or differentiate into inappropriate cell types. Gain and loss of function experiments have revealed key transcription factors which drive differentiation of immature stem/progenitor cells toward more mature stages and eventually to full differentiation. An attractive course of action to promote survival and direct the differentiation of transplanted stem cells to a specific cell type would therefore be to force expression of regulatory differentiation molecules in already transplanted stem cells, using inducible gene expression systems which can be controlled from the outside. Here, we explore this hypothesis by employing a tetracycline gene regulating system (Tet-On) to drive the differentiation of boundary cap neural crest stem cells (bNCSCs) toward a sensory neuron fate after transplantation. We induced the expression of the key transcription factor Runx1 in Sox10-expressing bNCSCs. Forced expression of Runx1 strongly increased transplant survival in the enriched neurotrophic environment of the dorsal root ganglion cavity, and was sufficient to guide differentiation of bNCSCs toward a nonpeptidergic nociceptive sensory neuron phenotype both in vitro and in vivo after transplantation. These findings suggest that exogenous activation of transcription factors expression after transplantation in stem/progenitor cell grafts can be a constructive approach to control their survival as well as their differentiation to the desired type of cell and that the Tet-system is a useful tool to achieve this.

Neural crest stem cells increase beta cell proliferation and improve islet function in co-transplanted murine pancreatic islets

“…We found no labelling with antibodies that identify specific sensory neurone subtypes (S. Vasilovska and E. N. Kozlova, unpublished observations), indicating that specific stimulation of neuronal differentiation may be necessary to achieve reinnervation of islets from co-transplanted NCSCs. We recently demonstrated that subtype-specific differentiation of NCSCs after transplantation of only neurospheres can be induced by activating specific transcription factors [22]. This approach provides an opportunity to re-innervate islets from differentiated NCSCs in this transplantation setting.…”

Differentiating neural crest stem cells induce proliferation of cultured rodent islet beta cells

“…The neurospheres formed by NCSCs isolated from the DRG of E11.5 mice [16] were insulin − (data not shown), proliferated and remained undifferentiated when cultured in PROP [10]. When cultured in DIFF, which differs from PROP by the absence of bFGF and EGF, or when subjected for 2 days to an in vitro differentiation assay [17], the cells differentiated into either GFAP + or β-tubulin III + cells [10]. When islets and neurospheres were co-cultured in PROP for 1 week on glass slides coated with poly-lysine and laminin, axonal length was short (Fig.…”

“…The DRG preparation included the boundary cap, a transient neural crestderived structure giving rise to the last wave of DRG neurons in development [12][13][14]. The NCSCs are multipotent stem cells that have been shown to generate sensory neurons in vitro [15,16] and glial cells and neurons in vivo after transplantation [17,18].…”

Molecular Control of the Neural Crest and Peripheral Nervous System Development

“…Boundary cap progenitors maintain a state of pluripotency somewhere between that of early NCCs and a Schwann cell progenitor (SCP), though in vitro studies have shown that these cells can even generate multiple CNS subtypes (Coulpier et al, 2009; Zujovic et al, 2010, 2011). These characteristics have led to a number of studies seeking to utilize boundary cap progenitor transplantation in spinal cord, peripheral nerve, and dorsal root injury paradigms (Aldskogius et al, 2009; Aquino et al, 2006; Trolle, Konig, Abrahamsson, Vasylovska, & Kozlova, 2014; Zujovic et al, 2010, 2011). …”