Increased Haematopoietic Supportive Function of USSC from Umbilical Cord Blood Compared to CB MSC and Possible Role of DLK-1
Figure 4
Haematopoiesis-supporting capacity of USSC and CB MSC. (a) Representative co-culture of CD34+-cells on feeders of USSC, CB MSC, and CB MSC overexpressing DLK-1 (CB MSCDLK) in multiple independent wells (). With regards to total cell count, expansion of CD34+-cells and colony-forming units (CFU), co-culture on a USSC-feeder resulted in higher expansion rates than on CB MSC-feeder. Within 14 days, total cell count increased significantly stronger on USSC-feeder (by factor ) than on CB MSC-feeder (factor ; ). Expansion of total CD34+-cells also resulted in significantly higher expansion on USSC (-fold) than on CB MSC ( fold; ). For colony-forming units, cells cultured on USSC-feeder showed a higher expansion rate on day 10 and 14 (up to -fold versus -fold; ). Overexpression of DLK-1 in the CB MSC line did not have an influence on expansion rates, as the results for CB MSC and CB MSCDLK were approximately identical. (b) Expression levels of haematopoietic cytokines (IGF-2, IGFBP-1, SCF, SDF-1, THPO, ANGPTL-3) in USSC, CB MSC, and BM MSC were analyzed by real time PCR. The expression of insulin-like growth factor binding protein (IGFBP-1) was highest in USSC (), while stromal-derived factor 1 (SDF-1) expression was higher in CB MSC () and BM MSC () compared to USSC. Thrombopoietin (THPO) and angiopoietin-like 3 (ANGPTL-3) were not detectable.
