Figure 4

Microenvironmental cues and neuronal marker expression. (A) Flow cytometry histograms showing neuronal marker expression by trans-retinoic acid (RA)-primed CD133+ABCG2+CXCR4+ MSC after co-culture allowing direct cell to cell contact with the rat astrocyte cell line (DITNC1). (B) Co-culture of RA-primed CD133+ABCG2+CXCR4+ MSC allowing cell to cell contact with human bone marrow cell line (HS-5). Isotype staining control for each is shown as a green overlay histogram. Control levels for all samples were ≤ 2% cells positive. (C) RA-primed CD133+ABCG2+CXCR4+ MSC were cultured allowing cell to cell contact (top graph) or no contact (bottom graph) with human astroglial (SVGp12), human neuroblastoma (SK-N-F1), rat astrocyte (DITNC1), human dopaminergic (SK-N-MC) cell line or, as a control, HS-5. Efficiency of neuronal marker expression after 7 days of culture for nestin, glial fibrillary acidic protein (GFA), anticholine acetyl transferase (CHAT), tyrosine hydroxylase (TH), type III beta tubulin (Tuj1) and galactocerebroside (GalC) production is shown. Results represent the average +/- SD for 10 donors. Statistically significant comparisons (*P < 0.05, **P < 0.005) are indicated for each marker compared to control cells, which were RA-primed but not cultured with any of the cell lines listed. Unprimed cells expressed < 2% positive cells when cultured with mature neural cells for all of the mature neuronal markers evaluated.