title: Culture-expanded human dermal stem cells exhibit donor to donor differences in cAMP generation.
abstract: Stem cell techniques have facilitated a number of potential uses for such cells in cell therapy and drug development. Studies of the cAMP/protein kinase A (PKA) pathway are widely employed to investigate the effects of a large variety of substances. We assayed the cAMP pathway in human skin-derived mesenchymal stem cells (S-MSC) to evaluate donor to donor variations in response to pharmacological manipulations in vitro. Immunophenotyping of S-MSC revealed that, in general, 95% of S-MSCs were positive for CD90, CD73 and CD105 and negative for the expression of haemopoetic markers CD14, CD45 and human leukocyte antigen-DR (HLA-DR). Nevertheless, fluctuations occurred in basal cAMP levels from 5 pmol/mg to 18 pmol/mg. Total cAMP response element binding protein (CREB) concentrations ranged from 0.8 ng/ml to 1 ng/ml, whereas the proportions of phospho-CREB versus total CREB differed between the cell lines. Basic fibroblast growth factor (FGF-2) and epidermal growth factor (EGF) stimulated cAMP generation, whereas leukaemia inhibiting factor reduced some of their effects. Forskolin (0.05 and 1 mM) acted in synergy with FGF-2 and EGF; however, it caused pronounced donor to donor differences in the increase of cAMP and phospho-CREB levels. Additionally, dibutyryl-cAMP caused significant donor to donor variations in cell proliferation, possibly indicating a change of cell differentiation status. We speculate that similar donor diversity might be observed after cell stimulation with various G(s)-protein-coupled receptor ligands. Heterogeneity of donor cell responses to stimulation of the cAMP pathway indicates the need for wide safety margins for S-MSC use in drug screening; nevertheless, knowledge of this heterogeneity might be useful for the design of donor-specific cell therapy.
authors.affiliation: University of Latvia, Riga.
authors.forename: Kaspars
authors.initials: K
authors.lastname: Jekabsons
authors.forename: Una
authors.initials: U
authors.lastname: Riekstina
authors.forename: Vadims
authors.initials: V
authors.lastname: Parfejevs
authors.forename: Anete
authors.initials: A
authors.lastname: Laizane
authors.forename: Marta
authors.initials: M
authors.lastname: Pavasare
authors.forename: Nelda
authors.initials: N
authors.lastname: Lencberga
authors.forename: Baiba
authors.initials: B
authors.lastname: Jansone
authors.forename: Ruta
authors.initials: R
authors.lastname: Muceniece
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008875:Middle Aged; D012867:Skin / Q000166:cytology* / Q000378:metabolism*
chemical_list: D000242:Cyclic AMP