Comparative analysis of human hematopoietic-, muscle-, and neural-derived hematopoietic progenitors.
Human tissues indicated were harvested under identical conditions, and functional hematopoietic progenitor capacity was evaluated at day 0 (de novo–isolated tissues) and again at day 5 of culture in HGF conditions with or without BMP-4 or BMP-4 together with EPO. (A) Developmental potential of hematopoietic progenitors was compared among various human tissues by enumerating colony types as a measure of hematopoietic lineage commitment that include erythroid (BFU-E), monocytic (CFU-M), granulocytic (CFU-G), and myelocytic (CFU-GM). Composition of CFU types generated for each tissue is expressed as mean percentage ± SEM (n = 5) of the total colonies for muscle (gray), neural (white), and blood (black) cells cultured in essential media containing HGF (i), BMP-4 (ii), or BMP-4 and EPO in combination (iii). Single and double asterisks indicate substantial differences within measured groups ofP < .01, (n = 5). (B) Fold changes in total hematopoietic progenitor expansion was compared in response to culture conditions indicated and compared with day 0 of cultured fetal blood (i), muscle (ii), and neural (iii) cells. Each graph shows the increase in progenitors after culture in essential media containing HGF (●), BMP-4 (♦), or BMP-4 and EPO (▪). (C) Fold expansion of fetal blood cultured for 5 days in the absence or presence of cells derived from fetal muscle (i) or fetal neural (ii) tissue using cytokine combinations indicated. Cells were cocultured using 5.0 × 105 fetal blood cells to equal numbers of fetal muscle or neural cells to maintain the same cell density used in previous experiments shown in panel B. Insets show the relative fold expansion to fetal blood cells cultured alone compared with the various coculture treatments. (D) Hematopoietic progenitors assayed from single cells suspensions of muscle (i), neural (ii), and blood (iii) in the absence or presence of BMP-4 directly added to methylcellulose used in this clonal assay. Graphs show number of clonogenic progenitor of de novo–isolated tissues in the absence of BMP-4 (control) shown standardized as 100% and in the presence of BMP-4 as a percentage relative to control ± SEM. Results are based on a total of 5 independent samples.
