Transforming growth factor β1 mediates cell-cycle arrest of primitive hematopoietic cells independent of p21Cip1/Waf1or p27Kip1

Blood ◽  
2001 ◽  
Vol 98 (13) ◽  
pp. 3643-3649 ◽  
Author(s):  
Tao Cheng ◽  
Hongmei Shen ◽  
Neil Rodrigues ◽  
Sebastian Stier ◽  
David T. Scadden
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Progenitor Cell ◽  
Transforming Growth Factor ◽  
Hematopoietic Cells ◽  
Transforming Growth Factor Β1 ◽  
Primitive Cell ◽  
Hematopoietic Stem ◽  
Tgf Β1

Abstract The regulation of stem cell proliferation is a poorly understood process balancing rapid, massive blood cell production in times of stress with maintenance of a multipotent stem cell pool over decades of life. Transforming growth factor β1 (TGF-β1) has pleiotropic effects on hematopoietic cells, including the inhibition of primitive cell proliferation. It was recently demonstrated that the cyclin-dependent kinase inhibitors, p21Cip1/Waf1 (p21) and p27Kip1 (p27), can inhibit the proliferation of hematopoietic stem cells and progenitor cells, respectively. The relation of TGF-β1 stimulation to p21 and p27 was examined using a fine-mapping approach to gene expression in individual cells. Abundant TGF-β1 expression and p21 expression were documented in quiescent, cytokine-resistant hematopoietic stem cells and in terminally differentiated mature blood cells, but not in proliferating progenitor cell populations. TGF-β1 receptor (TβR II) was expressed ubiquitously without apparent modulation. Cell- cycle–synchronized 32D cells exposed to TGF-β1 demonstrated a marked antiproliferative effect of TGF-β1, yet neither the level of p21 mRNA nor the protein level of either p21 or p27 was altered. To corroborate these observations in primary cells, bone marrow mononuclear cells derived from mice engineered to be deficient in p21 or p27 were assessed. Progenitor and primitive cell function was inhibited by TGF-β1 equivalently in −/− and +/+ littermate controls. These data indicate that TGF-β1 exerts its inhibition on cell cycling independent of p21 and p27 in hematopoietic cells. TGF-β1 and p21 or p27 participate in independent pathways of stem cell regulation, suggesting that targeting each may provide complementary strategies for enhancing stem or progenitor cell expansion and gene transduction.

Growth factor expression pattern of homologous feeder layer for culturing buffalo embryonic stem cell-like cells

2012 ◽  
Vol 24 (8) ◽  
pp. 1098 ◽  
Author(s):  
Ruchi Sharma ◽  
Aman George ◽  
Nitin M. Kamble ◽  
Manmohan S. Chauhan ◽  
Suresh Singla ◽  
...  
Keyword(s):  
Stem Cell ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Embryonic Stem ◽  
Transforming Growth Factor Β1 ◽  
Activin A ◽  
Feeder Layer ◽  
Es Cell ◽  
Fetal Fibroblasts ◽  
Tgf Β1

The present study examined the expression profile of buffalo fetal fibroblasts (BFF) used as a feeder layer for embryonic stem (ES) cell-like cells. The expression of important growth factors was detected in cells at different passages. Mitomycin-C inactivation increased relative expression levels of ACTIVIN-A, TGF-β1, BMP-4 and GREMLIN but not of fibroblast growth factor-2 (FGF-2). The expression level of ACTIVIN-A, transforming growth factor-β1 (TGF-β1), bone morphogenetic protein-4 (BMP-4) and FGF-2 was similar in buffalo fetal fibroblast (BFF) cultured in stem cell medium (SCM), SCM + 1000 IU mL–1 leukemia inhibitory factor (LIF), SCM + 5 ng mL–1 FGF-2 or SCM + LIF + FGF-2 for 24 h whereas GREMLIN expression was higher in FGF-2-supplemented groups. In spent medium, the concentration of ACTIVIN-A was higher in FGF-2-supplemented groups whereas that of TGF-β1 was similar in SCM and LIF + FGF-2, which was higher than when either LIF or FGF-2 was used alone. Following culture of ES cell-like cells on a feeder layer for 24 h, the TGF-β1 concentration was higher with LIF+FGF-2 than with LIF or FGF-2 alone which, in turn, was higher than that in SCM. In the LIF + FGF-2 group, the concentration of TGF-β1 was lower and that of ACTIVIN-A was higher in spent medium at 24 h than at 48 h of culture. These results suggest that BFF produce signalling molecules that may help in self-renewal of buffalo ES cell-like cells.

Human hematopoietic stem cells stimulated to proliferate in vitro lose engraftment potential during their S/G2/M transit and do not reenter G0

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4185-4193 ◽  
Author(s):  
Hanno Glimm ◽  
IL-Hoan Oh ◽  
Connie J. Eaves
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Cell Activity ◽  
Human Cord Blood ◽  
Hematopoietic Stem ◽  
A Cell

Abstract An understanding of mechanisms regulating hematopoietic stem cell engraftment is of pivotal importance to the clinical use of cultured and genetically modified transplants. Human cord blood (CB) cells with lymphomyeloid repopulating activity in NOD/SCID mice were recently shown to undergo multiple self-renewal divisions within 6 days in serum-free cultures containing Flt3-ligand, Steel factor, interleukin 3 (IL-3), IL-6, and granulocyte colony-stimulating factor. The present study shows that, on the fifth day, the transplantable stem cell activity is restricted to the G1fraction, even though both colony-forming cells (CFCs) and long-term culture-initiating cells (LTC-ICs) in the same cultures are approximately equally distributed between G0/G1and S/G2/M. Interestingly, the G0 cells defined by their low levels of Hoechst 33342 and Pyronin Y staining, and reduced Ki67 and cyclin D expression (representing 21% of the cultured CB population) include some mature erythroid CFCs but very few primitive CFCs, LTC-ICs, or repopulating cells. Although these findings suggest a cell cycle–associated change in in vivo stem cell homing, the cultured G0/G1 and S/G2/M CD34+ CB cells exhibited no differences in levels of expression of VLA-4, VLA-5, or CXCR-4. Moreover, further incubation of these cells for 1 day in the presence of a concentration of transforming growth factor β1 that increased the G0/G1 fraction did not enhance detection of repopulating cells. The demonstration of a cell cycle–associated mechanism that selectively silences the transplantability of proliferating human hematopoietic stem cells poses both challenges and opportunities for the future improvement of ex vivo–manipulated grafts.

Excessive Hematopoietic Stem Cell Proliferation Leads to Chromosomal Instability

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4772-4772
Author(s):  
Liliana Souza ◽  
Natalyn Hawk ◽  
Sweta Sengupta ◽  
Carlos Cabrera ◽  
Morgan L. McLemore
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Chromosomal Instability ◽  
Wild Type ◽  
Dna Breaks ◽  
Hematopoietic Stem ◽  
Stem Cell Proliferation ◽  
Double Stranded Dna

Abstract Truncation mutations in the granulocyte colony stimulating factor receptor (G-CSFR), common in severe congenital neutropenia (SCN), lead to excessive stem cell proliferation in response to G-CSF. These G-CSFR mutants are (at least indirectly) implicated in the progression of these patients to acute leukemia. Since SCN patients require continuous G-CSF treatment throughout their lifespan, we hypothesize that excessive stem cell proliferation can lead to DNA damage. Stem cells are relatively quiescent and rarely enter the cell cycle under normal conditions. During the cell cycle cells generate approximately 5000 single strand DNA lesions per nucleus (Vilenchik and Knudson, 2003). Approximately 1% of these lesions are ultimately converted to double strand DNA breaks (DSBs). Hematopoietic stem cells are found within the Sca+ ckit+ Lin- (KLS) population. Wild type and mice bearing a mutant G-CSFR similar to that found in patients with SCN were treated with G-CSF. After 21 days of treatment with G-CSF (10 ug/kg/day), the KLS population in the bone marrow increased four-fold in wild type mice and eight-fold in mutant mice. We isolated Lin-Sca+ bone marrow cells from these G-CSF treated mice and evaluated for the presence of double stranded DNA breaks by staining with anti-phospho-H2AX by immunofluorescence. H2AX is a histone whose phosphorylated form localizes to the site of double stranded DNA breaks. The results showed that there is an 8-fold increase in the DSB in wild type Lin-Sca+ and 10-fold in mutant Lin-Sca+ when compared to cells from untreated mice. This data suggests that excessive proliferation can contribute to an increase in DSBs in hematopoietic stem cells. Investigation of potential mechanisms contributing to DSB formation are ongoing. Understanding the causes and trends of chromosomal instability would improve our understanding of leukemogenesis and potentially reveal novel treatment strategies.

Human hematopoietic stem cells stimulated to proliferate in vitro lose engraftment potential during their S/G2/M transit and do not reenter G0

Blood ◽  
2000 ◽  
Vol 96 (13) ◽  
pp. 4185-4193 ◽  
Author(s):  
Hanno Glimm ◽  
IL-Hoan Oh ◽  
Connie J. Eaves
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Stem Cell ◽  
Hematopoietic Stem Cells ◽  
Transforming Growth Factor ◽  
Ex Vivo ◽  
Cell Activity ◽  
Human Cord Blood ◽  
Hematopoietic Stem ◽  
A Cell

An understanding of mechanisms regulating hematopoietic stem cell engraftment is of pivotal importance to the clinical use of cultured and genetically modified transplants. Human cord blood (CB) cells with lymphomyeloid repopulating activity in NOD/SCID mice were recently shown to undergo multiple self-renewal divisions within 6 days in serum-free cultures containing Flt3-ligand, Steel factor, interleukin 3 (IL-3), IL-6, and granulocyte colony-stimulating factor. The present study shows that, on the fifth day, the transplantable stem cell activity is restricted to the G1fraction, even though both colony-forming cells (CFCs) and long-term culture-initiating cells (LTC-ICs) in the same cultures are approximately equally distributed between G0/G1and S/G2/M. Interestingly, the G0 cells defined by their low levels of Hoechst 33342 and Pyronin Y staining, and reduced Ki67 and cyclin D expression (representing 21% of the cultured CB population) include some mature erythroid CFCs but very few primitive CFCs, LTC-ICs, or repopulating cells. Although these findings suggest a cell cycle–associated change in in vivo stem cell homing, the cultured G0/G1 and S/G2/M CD34+ CB cells exhibited no differences in levels of expression of VLA-4, VLA-5, or CXCR-4. Moreover, further incubation of these cells for 1 day in the presence of a concentration of transforming growth factor β1 that increased the G0/G1 fraction did not enhance detection of repopulating cells. The demonstration of a cell cycle–associated mechanism that selectively silences the transplantability of proliferating human hematopoietic stem cells poses both challenges and opportunities for the future improvement of ex vivo–manipulated grafts.

scholarly journals High proliferative potential-quiescent cells: a working model to study primitive quiescent hematopoietic cells

1998 ◽  
Vol 111 (13) ◽  
pp. 1867-1875 ◽  
Author(s):  
N. Fortunel ◽  
P. Batard ◽  
A. Hatzfeld ◽  
M.N. Monier ◽  
B. Panterne ◽  
...  
Keyword(s):  
Stem Cell ◽  
Transforming Growth Factor ◽  
Hematopoietic Cells ◽  
Inhibitory Effect ◽  
Cytokine Receptors ◽  
Proliferative Potential ◽  
Hematopoietic Stem ◽  
Quiescent Cells ◽  
Working Model ◽  
Multipotent Progenitors

Human adult hematopoietic stem cells are mostly quiescent or slow cycling. We have previously demonstrated that blocking of transforming growth factor-beta1 (TGF-beta1) is able to activate, in the presence of cytokines, primitive quiescent hematopoietic multipotent progenitors which could not grow in a two week semi-solid culture assay (short term culture). We have also shown that anti-TGF-beta1 can up-modulate c-KIT, the receptor of the stem cell factor (steel factor). To elucidate whether TGF-beta1 plays a central role in controlling the quiescence of hematopoietic primitive cells, it was necessary to demonstrate, as detailed in this study, that: (1) whatever the cytokine combination tested, addition of anti-TGF-beta1 releases from quiescence multipotent progenitors with a significantly higher hematopoietic potential than those activated by cytokines alone. (2) Other important cytokine receptors controlling the most primitive hematopoietic cells such as FLT3 and the IL6 receptor (IL6-R) are down-modulated by TGF-beta1 but rapidly up-modulated by anti-TGF-beta1. (3) Anti-TGF-beta1-sensitive multipotent and high proliferative potential progenitors express these cytokine receptors at a low level (FLT3(low) and IL6-Rlow). According to these results, we propose the working model of ‘High Proliferative Potential-Quiescent cells’ to refer to these primitive hematopoietic multipotent progenitors that are highly sensitive to the growth inhibitory effect of TGF-beta1. This model could be valid not only to study the human hematopoietic quiescent progenitors but also for other somatic stem cell systems.

TIMAP, a novel CAAX box protein regulated by TGF-β1 and expressed in endothelial cells

2002 ◽  
Vol 283 (1) ◽  
pp. C327-C337 ◽  
Author(s):  
Wangsen Cao ◽  
Subhendra N. Mattagajasingh ◽  
Hangxue Xu ◽  
Kwanghee Kim ◽  
Wolfgang Fierlbeck ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Transforming Growth Factor ◽  
Fluorescent Protein ◽  
Hematopoietic Cells ◽  
Transforming Growth Factor Β1 ◽  
Representational Difference Analysis ◽  
Rat Tissues ◽  
Novel Gene ◽  
Green Fluorescent ◽  
Tgf Β1

Representational difference analysis of the glomerular endothelial cell response to transforming growth factor-β1 (TGF-β1) revealed a novel gene, TIMAP (TGF-β-inhibited membrane-associated protein), which contains 10 exons and maps to human chromosome 20.q11.22. By Northern blot, TIMAP mRNA is highly expressed in all cultured endothelial and hematopoietic cells. The frequency of the TIMAP SAGE tag is much greater in endothelial cell SAGE databases than in nonendothelial cells. Immunofluorescence studies of rat tissues show that anti-TIMAP antibodies localize to vascular endothelium. TGF-β1 represses TIMAP through a protein synthesis- and histone deacetylase-dependent process. The TIMAP protein contains five ankyrin repeats, a protein phosphatase-1 (PP1)-interacting domain, a COOH-terminal CAAX box, a domain arrangement similar to that of MYPT3, and a PP1 inhibitor. A green fluorescent protein-TIMAP fusion protein localized to the plasma membrane in a CAAX box-dependent fashion. Hence, TIMAP is a novel gene highly expressed in endothelial and hematopoietic cells and regulated by TGF-β1. On the basis of its domain structure, TIMAP may serve a signaling function, potentially through interaction with PP1.

scholarly journals Ac-SDKP inhibits transforming growth factor-β1-induced differentiation of human cardiac fibroblasts into myofibroblasts

2010 ◽  
Vol 298 (5) ◽  
pp. H1357-H1364 ◽  
Author(s):  
Hongmei Peng ◽  
Oscar A. Carretero ◽  
Edward L. Peterson ◽  
Nour-Eddine Rhaleb
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Cardiac Fibroblasts ◽  
Transforming Growth Factor Β1 ◽  
Collagen Production ◽  
Smad7 Expression ◽  
Human Cardiac Fibroblasts ◽  
Tgf Β1

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) inhibits collagen production and cell proliferation in cultured rat cardiac fibroblasts, but its effect on differentiation of fibroblasts into myofibroblasts is not known. High amounts of transforming growth factor-β1 (TGF-β1) have been found in fibrotic cardiac tissue. TGF-β1 converts fibroblasts into myofibroblasts, which produce more extracellular matrix proteins than fibroblasts. We hypothesized that 1) Ac-SDKP inhibits TGF-β1-induced differentiation of fibroblasts into myofibroblasts; and 2) this effect is mediated in part by blocking phosphorylation of small-mothers-against-decapentaplegic (Smad) 2 and extracellular signal-regulated kinase (ERK) 1/2. For this study, we used human fetal cardiac fibroblasts (HCFs), which do not spontaneously become myofibroblasts when cultured at low passages. We investigated the effect of Ac-SDKP on TGF-β1-induced HCF transformation into myofibroblasts, Smad2 and ERK1/2 phosphorylation, Smad7 expression, cell proliferation, and collagen production. We also investigated TGF-β1 production by HCFs stimulated with endothelin-1 (ET-1). As expected, HCFs treated with TGF-β1 transformed into myofibroblasts as indicated by increased expression of α-smooth muscle actin and a higher proportion of the embryonic isoform of smooth muscle myosin compared with untreated cells. TGF-β1 also increased Smad2 and ERK1/2 phosphorylation but did not affect Smad7 expression. In addition, TGF-β1 stimulated HCF proliferation as indicated by an increase in mitochondrial dehydrogenase activity and collagen production (hydroxyproline assay). Ac-SDKP significantly inhibited all of the effects of TGF-β1. It also inhibited ET-1-stimulated TGF-β1 production. We concluded that Ac-SDKP markedly suppresses differentiation of human cardiac fibroblasts into myofibroblasts, probably by inhibiting the TGF-β/Smad/ERK1/2 signaling pathway, and thus mediating its anti-fibrotic effects.

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