Fig. 8.

TGF-β1 is the only autoexpressed ligand to the 7 receptors. The same microarray data used to identify the upregulation of the receptors IL21R, IL9R, F2R, TGFBR2, IL4R, ADIPOR2, and CSF2RB were searched for the expression of their matched-ligands. A: fold change in relative fluorescent intensities in marrow CD34+/CD38lo cells relative to culture derived MKs. Positive fold changes indicate higher RNA expression levels by culture-derived MKs than day 0 CD34+/CD38lo cells. Data are shown as means ± SD from 3 independent experiments. B: UCB CD34+ cells (day 0) were cultured with IL 3, IL6, SCF, TPO. After 10 days of culture, CD41+ cells were isolated by flow cytometry. RNA was isolated, semiquantitative RT-PCR was performed, and the PCR products are shown on a 1% agarose gel.