DEPARTAMENTO DE CIÊNCIAS DA VIDA ... - Estudo Geral

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I.1.2.1 - Immunophenotype
The Mesenchymal and Tissue Stem Cell Committee of the International Society for
Cellular Therapy proposed 3 minimal criteria to define human MSCs. Those are: i)
MSCs must be plastic-adherent when maintained in standard culture conditions; ii)
MSCs must express CD105, CD73 and CD90, and lack expression of CD45, CD34, CD14
or CD11b, CD79a or CD19 and HLA-DR surface molecules; iii) MSCs must differentiate
to osteoblasts, adipocytes and chondroblasts in vitro (Dominici et al., 2006). Although
MSCs express a high number of cell surface markers and those were all well
characterized, there is still no specific marker identified. However, there is a typical
neuroectodermal marker, nestin, which began to be regarded as a good marker for the
identification of MSCs (Mendez-Ferrer et al., 2010) and seems to be in agreement with
reports indicating at least a partial neuroectodermal origin of MSCs (Takashima et al.,
2007; Morikawa et al., 2009).
I.1.2.2 - CFU-F and proliferation capacity
Colony formation capacity is an important hallmark of stem cells and it
demonstrates the presence of highly proliferative cells in these cultures (Javazon et al.,
2001). MSCs also have the ability to form colonies in vitro after low-density plating or
single-cell sorting, however colonies derived from those assays are heterogeneous in
morphology, size and differentiation potential (Owen and Friedenstein, 1988;
Kuznetsov et al., 1997; Dominici et al., 2006).
I.1.2.3 - Multilineage differentiation capacity
MSCs are multipotent progenitor cells with the capability to differentiate in vivo
and in vitro into adipogenic, chondrogenic and osteogenic lineages (Caplan, 2009). This
capacity to differentiate in vitro into several mesenchymal phenotypes was what in
2006 the ISCT had defined as one of the main properties integrating the minimal
criteria that define MSCs (Dominici et al., 2006). However, those lineages are not the