Abstract
Purpose:
The olfactory mucosa (OM) is a region of continuous neural regeneration throughout life. The lamina propria (LP) in the OM harbours olfactory ensheathing cells (OEC), which both physically and chemically support regeneration in this tissue. OECs promote neural regeneration in spinal cord damage and have been investigated for use in experimental optic nerve disease including trauma and glaucoma. Due to the complexity of the OM tissue, isolation of a pure OEC population remains a challenge. In this study we have sought to characterise the OM tissue as a means to isolate a pure population of OECs from the OM.
Methods:
We performed immunohistochemistry, confocal and electron microscopy to characterise the olfactory mucosa tissue. Different cell sorting strategies such as FACS and differential adhesion were used to separate the different cell populations. Western blotting and RT-PCR techniques were used to analyse cell populations.
Results:
Staining of the OM tissue showed the presence of mesenchymal stem cells in the lamina propria of the OM and their location seem to indicate a MSC niche in the tissue. Further expression of other stem cell markers such as Sox2 and Pax6 was found in the LP, which could indicate the presence of a different stem cell (like) population. We used bone marrow derived mesenchymal stem cells (BMSC) to compare with cells isolated from the OM. These BMSCs also share marker expression with OECs including the commonly used OEC markers s100β and p75.
Conclusions:
The olfactory mucosa is a complex tissue with at least one or possibly more stem cell populations residing in the lamina propria. The MSC population found in the LP shares marker expression with the OECs which can complicate the OEC isolation process. A distinctive set of markers in combination with other cell sorting techniques may possibly provide a relatively pure population of OECs. Characterising the OM may help to optimise optic nerve repair strategies using OECs.
Keywords: 629 optic nerve •
615 neuroprotection