RESUMO
OBJECTIVES: In the past few decades, variety of foetal, embryonic and adult stem and progenitor cells have been tried with conflicting outcome for cell therapy of central nervous system injury and diseases. Cellular characteristics and functional plasticity of Globose basal stem cells (GBCs) residing in the olfactory epithelium of rat olfactory mucosa have not been studied in the past by the neuroscientists due to unavailability of specific markers for GBCs. In the present research, we standardized some techniques to isolate GBCs from rat olfactory epithelium in pure form using a highly selective GBC-III antibody passaged through fluorescence activated cell sorter (FACS). We also characterized these cells immunohistologically using various pluripotent stem cell markers. This work also throws some light on ionic channels present on these stem cells which are responsible for their neuron induction potential. MATERIALS AND METHODS: Globose basal stem cells were isolated from rat olfactory epithelium using GBC-III antibody and were characterized as multipotent stem cells using various neural progenitor markers. Ionic channels on GBCs were studied with voltage clamping. RESULTS: GBCs could be isolated in pure (99% purity) form and were found to be stained positive for all neural progenitor cell markers. Voltage gated Na(+) channels were completely absent, which proves the unexcitable nature of GBCs. Leaky K(+) channels were found to be present on the GBC which was of no significance. CONCLUSION: This research work can be helpful in understanding the nature of these stem cells and utilising them in future as potent candidates for neuro-regenerative therapies.
RESUMO
INTRODUCTION: Olfactory mucosa which is situated in the roof of the nasal cavity possesses an extremely peculiar and exceptional type of pluripotent stem cells called Globose Basal Cells (GBCs) which help in lifelong regeneration of the olfactory mucosa. Previous literature doesn't provide much knowledge on the cytological, histochemical and electrophysiological properties of these cells, as they have never been isolated in pure form. MATERIAL AND METHODS: Olfactory mucosa was obtained from six Albino Wistar rats by using standardized surgical and chemical separation procedures. GBCs were isolated by using different chemical, surgical and fluorescent techniques. RESULTS: In this research work, we standardized the techniques for isolating these stem cells in pure form from rat olfactory mucosa by tagging them with GBC-III antibody and separating them from other epithelial cells by using Fluorescence Activated Cell Sorter (FACS). GBC-III antibody is a mouse monoclonal IgM antibody which recognizes a 40 kDa surface antigen, which is a laminin receptor surface protein present on the GBCs. It is a highly specific marker for GBCs, unlike the earlier antibodies used, like GBC-I, which were nonspecific markers for GBCs and showed positive reactions, even with Horizontal Basal Cells (HBCs), sustentacular cells (Sus) and duct cells. This study also standardized the techniques for surgically excising the olfactory mucosa from the nasal septum and chemically separating the olfactory epithelium from the lamina propria. CONCLUSION: GBCs are an important group of cells which can be exploited in future to study and treat neuro-degenerative disorders like multiple sclerosis, brain ischaemia, etc. and spinal cord trauma, as they reside in a niche similar to the microenvironment in the central nervous system and have the similar ectodermal development as the neuronal and non-neuronal cells of the CNS. Moreover, olfactory epithelium is easily accessible for autologous transplantation of GBCs for different CNS disorders.
