Abstract
Abstract: :
Purpose: Side population cells (SP cells) have a highly enriched stem cell activity and can proliferate to regenerate damaged tissues. We identify SP cells in lacrimal glands (LG) for cell therapy of dysfunction in LG of dry eye such as in Sjogren's syndrome. Materials and Methods: SP cells of 6–week–old, C57BL/6J male mice LG were isolated by flow cytometry, based on the efflux of fluorescent dye, Hoechst 33342. RT–PCR was performed on the isolated SP cells to confirm the characteristic of gene expression. We also analyzed differential gene expressions between SP cells and main population cells (MP cells) by cDNA microarray to identify the specific marker molecules for SP cells. Results: SP cells comprised of about 0.5% of total LG cells and showed epithelial–like sheet formation on culture dishes. Isolated SP cells expressed breast cancer resistant protein (Bcrp1), which is a marker molecule for stem cells. With the use of cDNA microarray, several genes including sulfated glycoprotein 2 isoform1 (19.9X), mouse gene for beta–1–globin (14.4X), M. musculus beta–globin complex (12.9X), M. Musculus DNA for alpha–globin gene and flanking regions (9.1X) were observed. Among these, sulfated glycoprotein 2 isoform1 was targeted as one of the candidates for the marker molecules of LG and the upregulated gene expression was confirmed by RT–PCR and real–time PCR. Conclusion: SP cells were isolated from mice LG, which have certain stem cell characteristics. This study provides essential potential for new cell therapy for lacrimal gland dysfunction because SP cells can be a source of expansion in vitro by analyzing these marker molecules.
Keywords: lacrimal gland • gene/expression • regeneration