In:
Blood, American Society of Hematology, Vol. 90, No. 4 ( 1997-08-15), p. 1448-1457
Abstract:
We recently demonstrated that the gene encoding the peripheral cannabinoid receptor (Cb2) may be a proto-oncogene involved in murine myeloid leukemias. We show here that Cb2 may have a role in hematopoietic development. RNAse protection analysis showed that Cb2 is normally expressed in spleen and thymus. Cb2 mRNA is also expressed in 45 of 51 cell lines of distinct hematopoietic lineages, ie, myeloid, macrophage, mast, B-lymphoid, T-lymphoid, and erythroid cells. The effect of the fatty acid anandamide, an endogenous ligand for cannabinoid receptors, on primary murine marrow cells and hematopoietic growth factor (HGF )-dependent cell lines was then investigated. In vitro colony cultures of normal mouse bone marrow cells showed anandamide to potentiate interleukin-3 (IL-3)–induced colony growth markedly. Whereas HGFs alone stimulate proliferation of the various cell lines in serum-free culture only weakly, anandamide enhances the proliferative response of the cell lines to HGFs profoundly. This was apparent for responses induced by IL-3, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and erythropoietin. Anandamide was already effective at concentrations as low as 0.1 to 0.3 μmol/L and plateau effects were reached at 0.3 to 3 μmol/L. The addition of anandamide as single growth factor had no effect. The costimulatory effect of anandamide was not evident when cells were cultured with fetal calf serum (FCS), suggesting that FCS contains anandamide or another ligand capable of activating the peripheral cannabinoid receptor. Other cannabinoid ligands did not enhance the proliferative responsiveness of hematopoietic cells to HGFs. Transfection experiments of Cb2 in myeloid 32D cells showed that anandamide specifically activates proliferation through activation of the peripheral cannabinoid receptor. Anandamide appears to be a novel and synergistic growth stimulator for hematopoietic cells.
Type of Medium:
Online Resource
ISSN:
1528-0020
,
0006-4971
DOI:
10.1182/blood.V90.4.1448.1448_1448_1457
Language:
English
Publisher:
American Society of Hematology
Publication Date:
1997
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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