Subcellular distribution and mitogenic effect of basic fibroblast growth factor in mesenchymal uncommitted stem cells.
Uncommitted mesenchymal stem cells (MSC), upon commitment and differentiation give rise to several mature mesenchymal lineages. Although the involvement of specific growth factors, including FGF2, in the development of committed MSC is known, the effect of FGF2 on uncommitted progenitors remains unclear. We have analyzed on a comparative basis, the subcellular distribution and mitogenic effect of FGF2 in committed and uncommitted MSC prepared from human bone marrow. Indirect immunofluorescence studies showed strong nuclear FGF2 staining in both progenitors; however, cytoplasmic staining was only detected in committed cells. Western blot analysis revealed the presence of 22.5 and 21-22 kDa forms of FGF2 in the nucleus of both progenitors; however, their relative content was higher in uncommitted than in committed cells. Exogenous FGF2 stimulated proliferation and sustained quiescence in committed and uncommitted cells, respectively. These results show that both type of progenitors, apart from morphological and proliferative differences, display specific patterns of response to FGF2.
Benavente
Claudia A
CA
Programa Terapias Genicas y Celulares, INTA, Universidad de Chile, Santiago, Chile.
Sierralta
Walter D
WD
Conget
Paulette A
PA
Minguell
José J
JJ
D001854:Bone Marrow Cells; D018929:Cell Culture Techniques; D002453:Cell Cycle; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D019070:Cell Lineage; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism*; D020033:Protein Isoforms; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism; D016192:Resting Phase, Cell Cycle
D020033:Protein Isoforms; D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2