Zinc enhances the cell adhesion,migration,and self-renewal potential of human umbilical cord derived mesenchymal stem cells

BACKGROUND Zinc(Zn)is the second most abundant trace element after Fe,present in the human body.It is frequently reported in association with cell growth and proliferation,and its deficiency is considered to be a major disease contributing factor.AIM To determine the effect of Zn on in vitro growth and proliferation of human umbilical cord(hUC)-derived mesenchymal stem cells(MSCs).METHODS hUC-MSCs were isolated from human umbilical cord tissue and characterized based on immunocytochemistry,immunophenotyping,and tri-lineage differentiation.The impact of Zn on cytotoxicity and proliferation was determined by MTT and Alamar blue assay.To determine the effect of Zn on population doubling time(PDT),hUC-MSCs were cultured in media with and without Zn for several passages.An in vitro scratch assay was performed to analyze the effect of Zn on the wound healing and migration capability of hUC-MSCs.A cell adhesion assay was used to test the surface adhesiveness of hUC-MSCs.Transcriptional analysis of genes involved in the cell cycle,proliferation,migration,and selfrenewal of hUC-MSCs was performed by quantitative real-time polymerase chain reaction.The protein expression of Lin28,a pluripotency marker,was analyzed by immunocytochemistry.RESULTS Zn at lower concentrations enhanced the rate of proliferation but at higher concentrations(>100μM),showed concentration dependent cytotoxicity in hUC-MSCs.hUC-MSCs treated with Zn exhibited a significantly greater healing and migration rate compared to untreated cells.Zn also increased the cell adhesion rate,and colony forming efficiency(CFE).In addition,Zn upregulated the expression of genes involved in the cell cycle(CDC20,CDK1,CCNA2,CDCA2),proliferation(transforming growth factorβ1,GDF5,hypoxia-inducible factor 1α),migration(CXCR4,VCAM1,VEGF-A),and self-renewal(OCT4,SOX2,NANOG)of hUC-MSCs.Expression of Lin28 protein was significantly increased in cells treated with Zn.CONCLUSION Our findings suggest that zinc enhances the proliferation rate of hUC-MSCs decreasing the PDT,and maintaining the CFE.Zn also enhances the cell adhesion,migration,and self-renewal of hUC-MSCs.These results highlight the essential role of Zn in cell growth and development.

Overexpression of GATA binding protein 4 and myocyte enhancer factor 2C induces differentiation of mesenchymal stem cells into cardiac-like cells

BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.