Interfacing Sca-1(pos) mesenchymal stem cells with biocompatible scaffolds with different chemical composition and geometry.

An immortalized murine mesenchymal stem cell line (mTERT-MSC) enriched for Lin(neg)/Sca-1(pos) fraction has been obtained through the transfection of MSC with murine TERT and single-cell isolation. Such cell line maintained the typical MSC self-renewal capacity and continuously expressed MSC phenotype. Moreover, mTERT-MSC retained the functional features of freshly isolated MSC in culture without evidence of senescence or spontaneous differentiation events.

Criticality of the biological and physical stimuli array inducing resident cardiac stem cell determination.

The replacement of injured cardiac contractile cells with stem cell-derived functionally efficient cardiomyocytes has been envisaged as the resolutive treatment for degenerative heart diseases. Nevertheless, many technical issues concerning the optimal procedures to differentiate and engraft stem cells remain to be answered before heart cell therapy could be routinely used in clinical practice. So far, most studies have been focused on evaluating the differentiative potential of different growth factors without considering that only the synergistic cooperation of biochemical, topographic, chemical, and physical factors could induce stem cells to adopt the desired phenotype.

Hepatocyte growth factor effects on mesenchymal stem cells: proliferation, migration, and differentiation.

Hepatocyte growth factor (HGF), a pleiotropic cytokine of mesenchymal origin promoting migration, proliferation, and survival in a wide spectrum of cells, can also modulate different biological responses in stem cells, but the mechanisms involved are not completely understood so far. In this context, we show that short-term exposure of mesenchymal stem cells (MSCs) to HGF can induce the activation of its cognate Met receptor and the downstream effectors ERK1/2, p38MAPK, and PI3K/Akt, while long-term exposure to HGF resulted in cytoskeletal rearrangement, cell migration, and marked inhibition of proliferation through the arrest in the G1-S checkpoint. When added to MSCs, the K252A tyrosine kinase inhibitor prevented HGF-induced responses.