The Effects of All-trans Retinoic Acid on the Hematopoietic Cells of Untreated Human Umbilical Cord Blood and Mice

[Objective]To investigate the effects of all-trans retinoic acid (ATRA) on the hematopoiet-ic cells of untreated human umbilical cord blood and mice. [ Methods ](1) Different concentrations of A-TRA were added into the semisolid colony culture medium , and the effects of ATRA on the forming of CFU-GM, BFU-E and CFU-GEMM of human umbilical cord blood (hUCB) MNC were observed. (2)The system which contained 0. 5 umol/L ATRA and IL-6, G-CSF, EPO, SCF was used to culture hUCB MNC. The NC and CD34+ cells were counted, and the CFU-GM, BFU-E and CFU-GEMM were detected on day 7 and 14.(3) Different dosages of ATRA were used on BABL/C mice , and the WBC, CD34 + cells, RBC and PLT of the treated mice were counted on day 2, 4, 6 and 8 . [Results] (1) Proper consentra-tion of ATRA could enhance CFU-GM of hUCB but had no effects on BFU-E and CFU-GEMM. Higer con-sentration of ATRA could inhibit the colony formation of CFU-GM, BFU-E and CFU-GEMM. The concentra- tion of 0. 5μmol/L was the proper concentration for CFU-GM formation. As the concentration raised to 5. 0μmol/L , it began to inhibit all of the colony formation. If the consentration raised to 10μmol/L, no colony formation could be found. (2) On day 7 and day 14 after hUCB MNC were cultured in the liquid system which contained 0. 5μmol/L ATRA and IL-6, SCF, G-CSF, EPO, the CD34+ cells, CFU-GM, CFU-GEMM and BFU-E were all higher than that of control group.(3) After being treated with different dosages of ATRA, the WBC in the peripheror blood cells(PBC) and the CD34+ in the bone marrow(BM) of the mice began to rise on day 8. But ATRA had no effect on the PLT and RBC of mice. [Conclusion] (1)The consentration of ATRA from 0. 1 ~ 0. 5μmol/L can enhance the formation of CFU-GM of hUCB but had no effects on the formation of BFU-E and CFU-GEMM. As the consentration reaches 5. 0μmol/ L , ATRA inhibits the formation of CFU-GM, BFU-E and CFU-GEMM.(2)Combined with cytokines, A-TRA may delay the differentiation of CD34+ cells in the liquid culture system. (3) ATRA enhances the proliferation of WBC in the PBC and the CD34+ in the BM of mice, but had no effects on the PLT and RBC of mice.