Edith Cowan University, Research Online, Perth, Western Australia
Abstract
Neurodegenerative disorders are conditions that mainly affect the brain and the central nervous system (CNS). Each disease type is characterised by loss of function which results from death of a particular region. Interestingly enough, most of the time disease pathology is due to loss of specific cell types in the CNS. These pathological conditions have both high economic costs and social implications for society. To treat such conditions, either the lost cells must be replaced or the cells surrounding the damaged tissue must be induced to undergo repair to replace the lost cells. The former looks more achievable whereas the latter is problematic as the CNS has limited ability to regenerate. For cell replacement therapies, stem cells hold much promise in particular bone marrow stromal stem cells (BMSSCs). Bone marrow stromal stem cells are phenomenal in terms of their plasticity, their ability to renew themselves and their availability. Just about every possible use of BMSSCs has been proposed from diverse fields, but little success has been achieved in same fields. BMSSCs have been used successfully for bone marrow transplants and to regenerate whole organs for cell replacement therapies. However current research has focused on differentiation of BMSSCs into neural tissue for cell replacement therapies for neurodegenerative disorders has had little success. The initial approach was to optimise conditions for the growth and differentiation of BMSSCs. Once optimal conditions were characterised, experiments to induce differentiation of BMSSCs only produced a_ mixture of neuronal cells. Ideally for cell replacement therapy, only a single type of cell lost in the disease process needs to be replaced. Pax7 is a key transcription factor that drives neural differentiation and migration of neural cells during development. It is also thought to determine neural differentiation in the tectum, where it specifically drives the fate of precursor cells towards a neural lineage. Upregulation of the transcription factor Pax7 in stem cells may induce these stem cells to differentiate towards neural differentiation. Since Pax7 specifies neural cell fate and not any other cell type in the CNS, transfected cells should differentiate into neurons similar to those found in the tectum. It is hypothesised that transfecting stem cells with Pax7 would create a novel method of differentiating stem cells into a homogeneous population of neurons. The differentiated cells could then be used as cellular material for cell replacement therapies. In this project a variety of stem cells, P19 cells, NIH3T3 cells and BMSSCs were transfected with Pax7 and assessed for neural differentiation. P19 and NIH3T3 transfected cells clearly showed differentiation along a neurogenic lineage, specifically towards the neurons of midbrain. Sadly, the BMSSCs did not survive the transfection process and further optimisation of conditions is required to achieve neural differentiation of BMSSCs
