-
[show abstract]
[hide abstract]
ABSTRACT: Hepatocyte-like cells (NeoHepatocytes) generated from a peripheral blood monocyte-derived stem cell-like cell (the PCMO) are a promising alternative for primary hepatocytes in cell transplantation studies to cure liver diseases. However, to be therapeutically effective NeoHepatocytes are needed in large quantities. It was the aim of the present study to investigate i) whether the proportion of actively proliferating NeoHepatocytes can be enhanced by supplementing the PCMO differentiation medium (containing M-CSF, IL-3, and human serum) with either EGF or HB-EGF and ii) which signaling pathway underlies the promitotic effect.
EGF and HB-EGF enhanced cell proliferation of PCMOs as demonstrated by increased expression of cycle control genes (ABL, ANAPC2, CDC2, CDK4, CDK6), phosphorylation of the retinoblastoma protein, and increased PCMO cell numbers after stimulation with EGF or HB-EGF. EGF also raised the number of monocytes expressing the proliferation marker Ki67. PCMOs expressed the EGF receptors EGFR (ERBB1) and ERBB3, and expression of both increased during PCMO generation. Phosphoimmunoblotting of PCMOs indicated that both EGF and HB-EGF activated MEK-1/2 and ERK1/2 in a concentration-dependent fashion with the effect of EGF being more prominent. EGF treatment further decreased expression of p47phox and increased that of Nanog indicating enhanced dedifferentiation and pluripotency, respectively. Treatment with both EGF and HB-EGF resulted in NeoHepatocytes with improved functional parameters.
The results suggested that the addition of EGF or HB-EGF to PCMO differentiation medium superactivates MEK/ERK signaling which then increases both PCMO proliferation, number, and functional differentiation of PCMO-derived NeoHepatocytes.
Cell Communication and Signaling 08/2012; 10(1):23. · 5.50 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Adult stem or programmable cells hold great promise in diseases in which damaged or non-functional cells need to be replaced. We have recently demonstrated that peripheral blood monocytes can be differentiated in vitro into cells whose phenotypes resemble specialized cell types like hepatocytes and pancreatic beta cells. During phenotypic conversion the monocytes downregulate monocyte/macrophage differentiation markers being indicative of partial dedifferentiation and are partially reprogrammed to acquire a state of plasticity along with expression of various markers of pluripotency. These cells were termed “programmable cells of monocytic origin” (PCMOs). Current efforts focus on establishing culture conditions that increase both the plasticity and proliferation potential of PCMOs in order to be able to generate large amounts of blood-derived cells suitable for both autologous and allogeneic therapies
Stem Cells and Cancer Stem Cells. 04/2012; 6(4):367-375.
-
Hendrik Ungefroren,
Stephanie Groth,
Ayman Hyder,
Niels Thomsen, Hebke Hinz,
Norbert Reiling,
Evelin Grage-Griebenow,
Janka Held-Feindt,
Maren Schulze,
Andreas K Nüssler,
Fred Fändrich
[show abstract]
[hide abstract]
ABSTRACT: We have recently demonstrated that peripheral blood monocytes can be differentiated in vitro into hepatocyte-like cells using appropriate differentiation media. Phenotype conversion required prior in vitro culture in the presence of M-CSF, IL-3, and human serum, during which the cells acquired a state of plasticity, so were termed "programmable cells of monocytic origin" (PCMO). Here, we have further characterized the process of PCMO generation with respect to markers of monocyte-to-macrophage transition and pluripotency. During a 6-day culture period, various monocyte/macrophage differentiation markers were down-regulated being indicative of a process of partial dedifferentiation. Dedifferentiation and hepatic redifferentiation also proceeded in highly purified monocyte preparations, albeit with different kinetics, suggesting that the presence of nonmonocytes, or soluble factors derived from them, is not essential in order for monocytes to acquire a multipotent state. PCMOs expressed various markers of human embryonic stem cells with early induction of NANOG and OCT4. Expression of the pluripotency-associated OCT4A isoform was paralleled by a global rise in histone H3 methylation on Lys-4, a marker of active chromatin, and coincided with peak sensitivity to tissue-specific differentiation. These results show that peripheral blood monocytes can be induced in vitro to transiently acquire stem cell-like properties and concomitantly a state of increased differentiation potential toward the hepatocytic phenotype.
Stem cells and development 03/2010; 19(11):1769-80. · 4.15 Impact Factor
