[Stimulation of bone marrow stromal cells conditioned medium on the expansion of mature megakaryocytes and colony forming unit-megakaryocyte in vitro].

In this study the effects of bone marrow stromal cells conditioned medium on the expansion of mature megakaryocytes and colony forming unit-megakaryocyte (CFU-Meg) in vitro were investigated. The serum-free bone marrow fibroblast conditioned medium (F-CM), bone marrow endothelial cell conditioned medium (E-CM) and bone marrow macrophage conditioned medium (M-CM) were collected and ultrafiltrated by using Centriprep-10. F-CM, E-CM, M-CM, the retentate (>10 kDa F-CM, >10 kDa E-CM and >10 kDa M-CM) contained substances whose molecular weight was more than 10 kDa and the filtrate (<10 kDa F-CM, <10 kDa E-CM and <10 kDa M-CM) contained substances whose molecular weight was less than 10 kDa were added in liquid culture system respectively. The results showed that F-CM, >10 kDa F-CM and E-CM, >10 kDa E-CM significantly promoted the expansion of mature megakaryocytes in liquid culture system, the percentage of mature megakaryocytes compared with 0 h control were (287.33-/+16.77)%, (236.67-/+39.72)%, (141.21-/+17.47)% and (179.03-/+30.98)%. But <10 kDa F-CM, <10 kDa E-CM, M-CM, >10 kDa M-CM and <10 kDa M-CM had no positive effects on the expansion of mature megakaryocytes. The effects of F-CM, E-CM or M-CM on the expansion of CFU-Meg were also investigated. The results indicated that F-CM and E-CM promoted the expansion of CFU-Meg in liquid culture system. M-CM had no positive effect on the expansion of CFU-Meg. the percentage of CFU-Meg compared with 0 h control were (168.18-/+30.24)%, (215.17-/+17.4)% and (85.0-/+7.0)%. The results of reverse transcription-polymerase chain reaction (RT-PCR ) showed that transforming growth factor -beta1 (TGF-beta1) mRNA was expressed in bone marrow endothelial cells and was not expressed in bone marrow fibroblasts. Thrombopoietin (TPO) mRNA was expressed in bone marrow fibroblasts and was not expressed in bone marrow endothelial cells. These results suggest that F-CM, >10kDa F-CM and E-CM, >10kDa E-CM significantly promoted the expansion of mature megakaryocytes and CFU-Meg in liquid culture system. The effect of F-CM on the expansion of mature megakaryocytes is better than that of E-CM.