Cytokine expression by human marrow-derived mesenchymal progenitor cells in vitro: Effects of dexamethasone and IL-1α

Abstract

We previously reported the purification, culture-expansion, and osteogenic differentiation potential of mesenchymal progenitor cells (MPCs) derived from human bone marrow. As a first step to establishing the phenotypic characteristics of MPCs, we reported on the identification of unique cell surface proteins which were detected with monoclonal antibodies. In this study, the phenotypic characterization of human marrow-derived MPCs is further established through the identification of a cytokine expression profile under standardized growth medium conditions and in the presence of regulators of the osteogenic and stromal cell lineages, dexamethasone and interleukin-1 alpha (IL-1 alpha), respectively. Constitutively expressed cytokines in this growth phase include G-CSF, SCF, LIF, M-CSF, IL-6, and IL-11, while GM-CSF, IL-3, TGF-beta 2 and OSM were not detected in the growth medium. Exposure of cells in growth medium to dexamethasone resulted in a decrease in the expression of LIF, IL-6, and IL-11. These cytokines have been reported to exert influence on the differentiation of cells derived from the bone marrow stroma through target cell receptors that utilize gp130-associated signal transduction pathways. Dexamethasone had no effect on the other cytokines expressed under growth medium conditions and was not observed to increase the expression of any of the cytokines measured in this study. In contrast, IL-1 alpha increased the expression of G-CSF, M-CSF, LIF, IL-6 and IL-11 and induced the expression of GM-CSF. IL-1 alpha had no effect on SCF expression and was not observed to decrease the production of any of the cytokines assayed. These data indicate that MPCs exhibit a distinct cytokine expression profile. We interpret this cytokine profile to suggest that MPCs serve specific supportive functions in the microenvironment of bone marrow. MPCs provide inductive and regulatory information which are consistent with the ability to support hematopoiesis, and also supply autocrine, paracrine, and juxtacrine factors that influence the cells of the marrow microenvironment itself. In addition, the cytokine profiles expressed by MPCs, in response to dexamethasone and IL-1 alpha, identify specific cytokines whose levels of expression change as MPCs differentiate or modulate their phenotype during osteogenic or stromagenic lineage entrance/progression.

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction

“…Several growth factors, such as vascular endothelial growth factor(VEGF) [7][8][9][10][11][12], fibroblast growth factor (FGF) [7,13], hepatocyte growth factor (HGF) [14] and platelet-derived growth factor (PDGF), have been generated in the presence of MI to resist ischemia and irreversible heart death. As the loss is highly localized, the endogenous response may be insufficient to repair the damaged blood vessels.…”

Marrow mesenchymal stem cells transduced with TPO/FL genes as support for ex vivo expansion of hematopoietic stem/progenitor cells

“…We chose IL-6 as the control cytokine because expression was in a range similar to that of the transduced gene product and previous data showed similar expression of IL-6 from hMSCs over time in hMSC cultures [35]. We observed TPO transgene expression from TPO/FL-transduced hMSCs and primary hMSCs averaging 175 ± 85 and 25 ± 11ng/10 5 cells per 24 hours, respectively (fi g. …”

“…Human BM samples were collected from healthy human donors (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46) years old) at the First Affl iated Hospital, Zhejiang University, under an Institutional-Review-Boardapproved protocol. Mononuclear cells (MNCs) were plated in hMSC medium at a density of 2 x 10 7 cells per 75-cm 2 plastic fl ask (Nunc, Naperville, Ill.).…”

Support of hMSCs transduced with TPO/FL genes to expansion of umbilical cord CD34+ cells in indirect co-culture

“…2. We chose IL-6 as the control cytokine as its expression was in a range similar to that of the transduced gene product, and because previous data had shown a similar expression of IL-6 from hMSCs over time in hMSC cultures (Haynesworth et al 1996). We observed TPO transgene expression from tfhMSCs and hMSCs averaging 175±85 and 25±11 ng/10 5 cells per 24 h, respectively (Fig.…”