Abstract
Background aims. In this study we investigated the effect of neurotrophin-3 (NT-3) and knockdown of NG2, one of the main inhibitory chondroitin sulfate proteoglycans (CSPG), in the glial scar following spinal cord injury (SCI). Methods. Short hairpin (sh) RNA were designed to target NG2 and were cloned into a lentiviral vector (LV). A LV was also constructed containing NT-3. LV expressing NT-3, shRNA to NG2 or combinations of both vectors were injected directly into contused rat spinal cords 1 week post-injury. Six weeks post-injection of LV, spinal cords were examined by histology for changes in scar size and by immunohistochemistry for changes in expression of CSPG, NT-3, astrocytes, neurons and microglia/macrophages. Motor function was assessed using the Basso, Beattie and Bresnahan (BBB) locomotor scale. Results. Animals that received the combination treatment of LV shNG2 and LV NT-3 showed reduced scar size. These animals also showed an increase in levels of neurons and NG2, a decrease in levels of astrocytes and a significant functional recovery as assessed using the BBB locomotor scale at 2 weeks post-treatment. Conclusions. The improvement in locomotor recovery and decrease in scar size shows the potential of this gene therapy approach as a therapeutic treatment for SCI.
Acknowledgements
We wish to thank Professor Dider Trono (EFPL, Switzerland) for the kind gift of the lentiviral vector gene transfer and packaging plasmids. The authors wish to acknowledge the facilities and scientific assistance of the Centre for Microscopy and Imaging at the National University of Ireland Galway (www.imaging.nuigalway.ie), a facility that is funded by NUIG and the Irish Government’s Programme for Research in third Level Institutions, Cycles 4 and 5, National Development Plan 2007–2013.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
This work was supported by funding from the Health Research Board of Ireland and Science Foundation Ireland.