Rooney, Gemma E.

Object Glial scar and cystic formation greatly contribute to the inhibition of axonal regeneration after spinal cord injury (SCI). Attempts to promote axonal regeneration are extremely challenging in this type of hostile environment. The objective of this study was to examine the surgical methods that may be used to assess the factors that influence the level of scar and cystic formation in SCI. Methods In the first part of this study, a complete transection was performed at vertebral level T9–10 in adult female Sprague-Dawley rats. The dura mater was either left open (control group) or was closed using sutures or hyaluronic acid. In the second part of the study, complete or subpial transection was performed, with the same dural closure technique applied to both groups. Histological analysis of longitudinal sections of the spinal cord was performed, and the percentage of scar and cyst formation was determined. Results Dural closure using sutures resulted in significantly less glial scar formation (p = 0.0248), while incorporation of the subpial transection surgical technique was then shown to significantly decrease cyst formation (p < 0.0001). Conclusions In this study, the authors demonstrated the importance of the vasculature in cyst formation after spinal cord trauma and confirmed the importance of dural closure in reducing glial scar formation.

The aims of this research were to examine the neural expression profile of undifferentiated mesenchymal stem cells (MSCs), to define a serum-free environment that would support the survival of MSCs, and to assess the effects of elevated cyclic adenosine monophosphate (cAMP) levels on MSC morphology and expression of neural markers. The neural profile of MSCs was assessed using immunocytochemistry and real-time polymerase chain reaction (PCR) techniques. These MSCs were then cultured in varying serum-free environments, with flow cytometry analysis of cell viability and apoptosis. The effects of forskolin and 8 bromo-cAMP treatment on MSC morphology and expression of neural markers were assessed using light microscopy, immunocytochemistry and real-time PCR analysis. Expression of the neural markers nestin, vimentin, β III tubulin, glial fibrillary acidic protein, and the tropomyosin-related kinases was demonstrated in normal undifferentiated MSCs. Furthermore, MSCs cultured in serum-free conditions containing ascorbic acid 2-phosphate demonstrated greater long-term survival and reduced apoptosis. In contrast, forskolin increased the percentage of cells undergoing apoptosis. Culture in the presence of forskolin induced a 6-fold increase in β III tubulin expression after a 6-h exposure time, which was accompanied by dramatic changes in morphology. However, this effect was transient, with the cells reverting to their normal morphology by 24 h. Treatment with 8 bromo-cAMP induced similar increases in β III tubulin expression without such dramatic morphological changes. Factors which increase the concentration of cAMP induce transient changes in expression of neural markers that appear to be the result of cellular adaptation to changes in culture conditions rather than a real process of neural differentiation.