[Effect of transforming growth factor-beta1 on proliferation and apoptosis of mononuclear cells of cord blood].
To explore the mechanism of transforming growth factor-beta1 (TGF-beta1) effect on umbilical cord blood mononuclear cells proliferation and apoptosis, 5-bromo-2'-deoxyurine (BrdU) incorporation assay was adopted to detect effect of TGF-beta1 on synthesis of DNA in cells. Western blot method was used to examine effect of TGF-beta1 on expression of cyclin A, Cyclin D1, CDK2 and CDK4 in G1 phase of cell cycle. Giemsa staining and flow cytometry (FCM) were performed to detected effect of TGF-beta1 on cell apoptosis. The results showed that (1) after culture of cells with IMDM containing 10% FBS, 10% FBS + 1 ng/ml TGF-beta1, 10% FBS + 2 ng/ml TGF-beta1 or 10% FBS + 5 ng/ml TGF-beta1 for 12 hours the OD values of TGF-beta1 group were significantly lower than control group (P <0.01); after culture for 24 hours the OD values of 1 ng/ml TGF-beta1 group had no significant difference compared with control group (P >0.05), but the OD values of 2 ng/ml and 5 ng/ml TGF-beta1 groups were significantly lower than control group (P <0.05). (2) 2 ng/ml TGF-beta1 could significantly inhibit the production of cyclin A, cyclin D1, CDK2 and CDK4, the protein levels were significantly lower than control group. (3) when the cells were co-cultured with 2 ng/ml TGF-beta1 for 12 and 24 hours, Giemsa staining and FCM detection could display typical apoptosis, the apoptosis rates were 14.42% and 31.98%, while apoptosis rate in control were 4.71% and 5.76%. It is concluded that TGF-beta1 can inhibit production of G1 cyclins and CDKs of umbilical cord blood mononuclear cells, arrest cells in the G1 phase of cell cycle and induce cell apoptosis. Thus, TGF-beta1 may be an important negative modulator in hematopoiesis.
Shi
Bin
B
Department of Hematology Fuxing Hospital, Capital Medical University, Beijing 100038, China.
Zhao
Xiang-Fu
XF
Cui
Jiang-Ying
JY
Wang
Shen-Wu
SW
D017209:Apoptosis / Q000187:drug effects*; D042846:CDC2-CDC28 Kinases / Q000032:analysis; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D019925:Cyclin A / Q000032:analysis; D019938:Cyclin D1 / Q000032:analysis; D051357:Cyclin-Dependent Kinase 2; D004247:DNA / Q000096:biosynthesis; D005312:Fetal Blood / Q000166:cytology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
D019925:Cyclin A; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D019938:Cyclin D1; D004247:DNA; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2