In order to investigate the direct effects of retinoids on normal adult hematopoietic progenitors, purified CD34+ cells were seeded in serum-free cultures in the presence of pharmacological (10-6) M or physiological (10- 12) M concentrations of all-trans retinoic acid (ATRA) and 9-cis retinoic acid (9-cis RA) plus combinations of specific cytokines. 10-6 M ATRA and 9- cis RA significantly decreased the number of granulomacrophagic, erythroid and megakaryocytic (CFU- meg) progenitors. On the other hand, 10-12 M ATRA significantly promoted the growth of CFU-meg, in the presence either of thrombopoietin or of IL-3+GM-CSF, and induced a reproducible stimulation of the immature CD34+DR- subset. In conclusion, our findings suggest that retinoic acids probably play a direct role in normal adult hematopoietic development at both physiological and pharmacological concentrations. The stimulatory effect on megakaryocytopoiesis should be considered in the perspective of a potential use of low-dose ATRA, combined with thrombopoietin or other cytokines, in pathological conditions where the megakaryocytic compartment is impaired and the stimulation of megakaryocytopoiesis is requested.
|Number of pages||5|
|Journal||European Journal of Haematology|
|Publication status||Published - 1999|
- All-trans retinoic acid
- Autolog ous transplantation
ASJC Scopus subject areas