Study Of The Effect Of MicroRNA-21 On Proliferation And TGF-?1 Expression Of Human Cord Blood Mesenchymal Stem Cells

Objective Umbilical cord blood mesenchymal stem cells(MSCs)that derived from human umbilical cord blood have strong differentiation ability,low risk of disease infectious and little damage for donors.Umbilical cord blood MSCs can differentiate into myocardial cells,nerve cells,cartilage cells,bone cells and can be used for the treatment of various diseases.MicroRNAs(miRNAs)are small endogenous noncoding RNAs with 18-24 nucleotides.Mi RNA can act as regulators of gene expression by cleaving mRNA or repressing mRNA translation.Such regulatory function makes miRNA capable of modulating cell proliferation,differentiation and apoptosis.Moreover,miRNA can be involved in regulating the proliferation and differentiation of MSCs.Thus the objective of this progect was to investigate the effect of miR-21 on the proliferation and TGF-?1 expression of MSCs.Methods(1)MSCs were isolated and cultured in vitro to explore their biological characteristics and affection factors for the culture.(2)The expression of miR-21 and TGF-?1 in human umbilical cord blood MSCs were measured through real-time PCR and western blotting,respectively.And the expression levels of miR-21 and TGF-?1 were compared with that in cancer cells.(3)The effect of miR-21 on proliferation and TGF-?1 expression on MSCs has been evaluated.The MSCs was isolated and cultured form human cord blood.MSCs were transfected with microRNA-21 mimics and microRNA-21 inhibitors by using Lipofectamine? 2000 Reagent.The proliferation influence of the transfected MSCs was detected by MTT assay.The expression of miR-21 and mRNA of TGF-?1 wasdetermined by qRT-PCR.The expression of protein of TGF-?1 was assessed through Western blotting.Results(1)It turned out that the cover of culture bottle by fetal bovine serum can promote cell adherence,the 5% DMEM-LG culture medium can promote cell proliferation and purification.Moreover,the rotate speed and time of centrifuge can also effect the proliferation and purification of MSCs.(2)Taking the MCF-7 cells as contrast,the expression quantity of miR-21 and TGF-?1 in MSCs has been detected through real time PCR and Western blotting.The results revealed that the miR-21 was low expression and the TGF-?1 was high expression in MSCs.(3)The results indicated that the MSCs proliferation activity decreased significantly after transfected miR-21 mimics,MSCs proliferation activity increased significantly after transfected miR-21 inhibitors.The MSCs transfected miR-21 mimics exhibited up-regulated miR-21 expression and attenuated TGF-?1 expression,MSCs transfected miR-21 inhibitors exhibited down-regulated miR-21 expression and up-regulated TGF-?1 expression.Therefore,miR-21 mimics can attenuate TGF-?1expression and suppress the proliferation activity of MSCs significantly.Conclusion Mi R-21 mimics can significantly inhibit the proliferation of human umbilical cord blood MSCs and decrease the expression of TGF-?1.MiR-21 inhibitor can significantly enhance the proliferation of human umbilical cord blood MSCs and promote the expression of TGF-?1.In view of the important role of TGF-?1 in the regulation of MSC proliferation,it is speculated that miR-21 may affect the proliferation of human umbilical cord blood by regulating the expression of TGF-?1.