Spinal cord regeneration following injury represents a major clinical challenge. Over recent years, stem cells have demonstrated promise for promoting spinal repair in the lab and in early stage clinical trials through functional replacement of neuronal and glial cells and through secondary trophic mechanisms to promote endogenous regeneration. Research has primarily focused on the use of embryonic tissue-derived stem cells of potentially limited therapeutic application due to related ethical concerns. The dental pulp harbours a source of easily accessible progenitor cells that have demonstrated early promise in improving functional outcome of experimental models of spinal cord injury via growth factor release. This thesis explores the potential of dental pulp progenitor cells (DPPCs) to promote spinal repair through direct cellular replacement. Progenitor cells isolated from murine incisors were found to express early stage neural and glial markers. Specific protocols were developed demonstrating the ability of DPPCs to differentiate in vitro into neuronal-like and oligodendrocyte-like cells with appropriate morphology and expression of mature markers. Electrophysiological testing revealed that DPPC-derived neuronal-like cells were of an immature non-functional phenotype. Undifferentiated DPPCs injected into an ex vivo spinal cord slice model showed signs of proliferation, migration and spontaneous differentiation within spinal tissue. DPPCs pre-differentiated into oligodendrocyte-like cells failed to survive transplantation but neuronally pre-differentiated cells survived, showing signs of integration into endogenous neuronal pathways. In a small scale pilot study, neuronally pre-differentiated DPPCs were transplanted into a clinically relevant in vivo model of spinal cord injury. DPPCs maintained expression of neuronal markers four weeks after grafting into the injured spinal cord. Axonal projections towards grafted cells and synaptic protein expression suggested possible integration into neuronal pathways, albeit without an associated statistical functional improvement. The results presented in this thesis provide a strong case for the potential of DPPCs to facilitate functional recovery through direct cell replacement mechanisms.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:585329 |
| Date | January 2013 |
| Creators | Young, Fraser |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/53879/ |
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