ISOLATION AND DIFFERENTIATION OF STEM CELLS: SEARCHING FOR NEW MARKERS

Abstract MSCs are the most studied adult stem cells, as they can be isolated from almost any tissue, they show a good self-renewal capacity in vitro and they also possess good “plasticity”(jiang nature). Oddly, MSCs are identified and defined by a combination of markers that are not distinctive, as they are shared by other cells including fibroblasts. Therefore, pure populations of MSCs cannot be isolated, as they are always contaminated by other adult cells that often do not possess stem cell plasticity. Thus, it would be very desirable to discover novel cell surface markers that would allow to discriminate MSCs from other cells. Moreover, new ways to control and promote cell differentiation are needed. Thus, it becomes crucial to search for new key molecules that can be modulated to increase MSCs differentiation toward the desired tissue or inhibit the differentiation when cells have to remain in an undifferentiated state. In this direction, we focused our attention on SLs, a family of lipids found in the outer leaflet of the plasma membrane and involved in many cell signaling pathways. Therefore, main aims of this work were: 1. to investigate the possible use of SLs as new surface markers for the identification, characterization and possibly isolation of human bone marrow MSCs; 2. to investigate the involvement of SLs in the preservation of the undifferentiated state of MSCs during in vitro culturing 3. to assess the possible role of SLs in the differentiation processes of MSCs upon opportune stimuli.