Cardiac precursors in human bone marrow and cord blood: in vitro cell cardiogenesis

BACKGROUND: Cell transplantation has come of age but numerous questions still remain. Which type of cell should be used? Cardiac precursors are present in mouse bone marrow and used to repair the infarcted myocardium in mice. We searched for these precursors in human bone marrow and analyzed gene expression patterns in cells induced to differentiate in vitro. METHODS: Cells from human bone marrow were isolated and cultured in medium supplemented with autologous serum and 5% CO2. Cell characterization was performed by immunocytochemical analysis. mRNA was isolated and retrotranscribed. The active genes were detected with polymerase chain reaction by using specific oligonucleotides. RESULTS: Some inducers pushed the cell through different stages of cardiogenesis, with expression of cardiac transcriptional activators and structural proteins. Some combinations of stimuli were able to drive cells to advanced stages of cardiogenesis. CONCLUSIONS: These studies lead to an exact description of in vitro cardiogenesis in humans. Our aim was also to assess the residual proliferative capacity of cells and to enhance the differentiation efficiency, thus maximizing their repair capacity and the likelihood that they functionally integrate with the surrounding cardiac tissue.