Gene expression profiling for adult human olfactory neuroepithelial-derived progenitors

The olfactory neuroepithelium (ONe) is, a specialized tissue that lines a region of the nasal cavity high in the nasal vault, characterized by its life-long regenerative capacity. The purpose of the study was to further characterize and to compare gene expression profiling in neurosphere-forming cells (NSFCs) derived from primary cultures of ONe using a genome-wide array approach. Total RNA was isolated from p14, p78, and p189 in vitro passages and hybridized to the human genome-wide CodeLink Bioarrays. Differentially expressed genes were identified in 9 arrays using statistical filters and bioinformatics analysis. Of 55,775 transcripts, 11,345 (in all passages) were detected and 7,115 were commonly expressed in 9 arrays. From the 7,115 transcripts, 2,690 transcripts were expressed in stem cells. Of these 2,690 transcripts, 1,117 genes containing RefSeq accession numbers were identified and further classified based on their functional similarities using Gene Ontology (GO) tools. The changes in expression levels revealed by microarray experiments were validated using real-time RT-PCR analysis. Biological pathways were constructed to better understand the biological significance of the differentially expressed genes. Each passage of NSFCs was characterized immunocytochemically and compared using antibodies to peripherin, β-tubulin III, and nestin. The array results indicate the presence of both neuronal and epithelial phenotypes within the population of NSFCs. The pattern of gene expression of the NSFCs was unique compared to other lines perhaps reflecting species related differences and or adult versus embryonic derived stem cells.