FIG. 4.

Characterization of in vitro expanded ITSCs. (A) Secondary neurospheres formed from cells cultured from biopsy of human turbinates. Scale bar: 100 μm. (B) Scanning electron microscope image of a secondary neurosphere. Scale bar: 10 μm. (C) Reverse transcriptase PCR analysis showed the expression of the stem cell marker nestin, the neural crest-related transcripts Slug, p75, and SOX10 and the Schwann cell marker CNPase. cDNA was normalized using the housekeeping gene β-Actin. (D) Immunocytochemical staining showed that neurospheres are positive for the stemness marker nestin. Nuclei were stained with SYTOX Green. Scale bar: 20μm (E) Comparison of gene expression of the transcription factors and genes important for reprogramming. C-MYC, WDR5, and KLF4 are expressed by ITSCs at the same level or even higher, whereas OCT4, SOX2, LIN28, and NANOG are expressed at lower levels compared with HUES6. (F) Verification of the results from microarray experiments by real-time PCR. SOX2 and OCT4 are expressed at a lower level compared with NTERA-2 whereas WDR5 and KLF4 are nearly expressed at the same level. (G) Expression level of pluripotency-associated transcripts as measured by microarray analysis.