scholarly journals The role of the homeobox gene, HOX B7, in human myelomonocytic differentiation

Blood ◽  
1995 ◽  
Vol 85 (3) ◽  
pp. 692-697 ◽  
Author(s):  
MC Lill ◽  
JF Fuller ◽  
R Herzig ◽  
GM Crooks ◽  
JC Gasson
Keyword(s):  
Cell Line ◽  
Vitamin D3 ◽  
Critical Role ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Hl60 Cell ◽  
Monocytic Differentiation ◽  
Granulocytic Differentiation ◽  
Gm Csf

Homeobox genes encode transcription factors known to be important morphogenic regulators during embryogenesis. An increasing body of work implies a role for homeobox genes in both hematopoiesis and oncogenesis. We have analyzed the role of the homeobox gene, HOX B7, in the program of differentiation of the biphenotypic myeloid cell line, HL60. Induction of monocytic differentiation in HL-60 cells by vitamin D3 resulted in rapid expression of HOX B7 mRNA, but stimulation with phorbol ester or dimethyl sulfoxide (DMSO) did not. Constitutive overexpression of HOX B7 in the HL60 cell line inhibited the granulocytic differentiation associated with stimulation with DMSO or retinoic acid, but had no effect on the monocytic differentiation induced by vitamin D3. Normal human monocytes do not constitutively express HOX B7, nor are they able to be induced to do so by stimulation with colony-stimulating factor 1 (CSF-1) and gamma interferon (IFN gamma), or with vitamin D3 and lipopolysaccharide. Human bone marrow (BM) cells were found to express HOX B7 in response to granulocyte- macrophage CSF (GM-CSF) and antisense oligonucleotides directed against HOX B7 inhibited the formation of colonies derived from GM-CSF- stimulated BM. These data suggest a critical role for HOX B7 in myelomonocytic differentiation.

scholarly journals Eosinophil-specific deletion of IκBα in mice reveals a critical role of NF-κB–induced Bcl-xL for inhibition of apoptosis

Blood ◽  
2015 ◽  
Vol 125 (25) ◽  
pp. 3896-3904 ◽  
Author(s):  
Christian Schwartz ◽  
Ralf Willebrand ◽  
Silke Huber ◽  
Rudolf A. Rupec ◽  
Davina Wu ◽  
...  
Keyword(s):  
Helminth Infection ◽  
Critical Role ◽  
Gm Csf ◽  
Eosinophil Survival ◽  
Key Points ◽  
Specific Deletion ◽  
Specific Inhibitors

Key Points IL-3, IL-5, and GM-CSF promote eosinophil survival by NF-κB–induced upregulation of Bcl-xL, which can be blocked by specific inhibitors. Specific and constitutive deletion of the inhibitor of NF-κB (IκBα) in eosinophils in vivo reduced apoptosis during helminth infection.

scholarly journals Preexisting Virus-Specific T Lymphocytes-Mediated Enhancement of Adenovirus Infections to Human Blood CD14+ Cells

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 154
Author(s):  
Fengling Feng ◽  
Jin Zhao ◽  
Pingchao Li ◽  
Ruiting Li ◽  
Ling Chen ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Viral Infection ◽  
Viral Infections ◽  
Critical Role ◽  
Scavenger Receptor ◽  
Activation Markers ◽  
Gm Csf ◽  
Cell Responses ◽  
Underlying Mechanisms

Antigen-specific T lymphocytes play a critical role in controlling viral infections. However, we report here that preexisting virus-specific T cell responses also contribute to promoting adenovirus (Ad) infection. Previously, we found that CD14+ monocytes from Ad-seropositive individuals exhibited an increased susceptibility to Ad infection, when compared with that of Ad-seronegative individuals. But the underlying mechanisms for this enhancement of viral infection are not completely clarified. In this study, we found that the efficacy of Ad infection into CD14+ monocytes was significantly decreased after CD3+ T lymphocytes depletion from PBMC samples of Ad-seropositive individuals. In contrast, adding virus-specific CD3+ T lymphocytes into PBMC samples of Ad-seronegative individuals resulted in a significant increase of infection efficacy. CD3+ T lymphocytes in PBMC samples from Ad-seropositive individuals were more sensitive to be activated by adenovirus stimulus, characterized by upregulation of multiple cytokines and activation markers and also enhancement of cell proliferation. Further studies demonstrated that GM-CSF and IL-4 can promote Ad infection by up-regulating the expression of scavenger receptor 1 (SR-A) and integrins αVβ5 receptor of CD14+ cells. And taken together, these results suggest a novel role of virus-specific T cells in mediating enhancement of viral infection, and provide insights to understand the pathogenesis and complicated interactions between viruses and host immune cells.

NCoA4 Containing Transcriptional Complexes Modulates Response of Myelomonocytic Leukemic Cell Line to Retinoids and VD3.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4238-4238
Author(s):  
Aurelie Baudet ◽  
Laurent Delva ◽  
Patrick Balaguer ◽  
David Piquemal ◽  
Jacques Marti ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cell Line ◽  
Real Time ◽  
Nuclear Receptors ◽  
Growth Arrest ◽  
Leukemic Cells ◽  
U937 Cells ◽  
Monocytic Differentiation ◽  
Granulocytic Differentiation ◽  
Transcriptional Complexes

Abstract Large scale analyses of transcriptome improve comprehension of complex processes such as differentiation or cell proliferation. SAGE libraries construction of the AML model U937 allowed the identification of new markers of myelomonocytic differentiation induced by retinoids and vitamin D3 (VD3) (Piquemal et al., 2002). Those molecules act through ligand-dependent transcription factors of the nuclear receptors family: RAR, RXR and VDR. Among differentially expressed members of transcriptional complexes, the most relevant was the co-regulator NCoA4 (Nuclear receptor Coactivator 4). This protein that modulates interactions between transcription factors, RNA polymerase II and chromatin remodeling factors, was initially described as a co-activator of the androgen receptor (AR). Its activity has been extended to receptors of estrogens (ER), peroxisome-proliferating activators (PPAR), retinoid X (RXR) and recently to VD3 receptor (VDR). Using real-time semi-quantitative PCR, we found that NCoA4 is specifically expressed during the monocytic differentiation of U937 but not during the granulocytic differentiation of NB4 cell lines. These results were confirmed by analysis on normal and in vitro-differentiated leukemia primary cells. Moreover, its early induction, within 6 hours of retinoids and VD3 treatment on U937 cells, suggests that its expression may be controlled by one or several nuclear receptors. Because of cross-talks between retinoids and VD3 pathways, we used NB4-LR2 cells in which RAR is knock-down. In this cell line, NCoA4 is expressed in a VDR-dependent fashion reinforcing the hypothesis that the coregulator is specifically involved in the VD3-monocytic differentiation of leukemic cells. Next, to explore the role of NCoA4, U937 cells were stably transfected to constitutively over-express the protein. The doubling time of this cell line (U-NCoA4) reaches to 48 hours against 24 hours in U937 cells. Concerning ligand-induced growth arrest, these cells are particularly sensitive to the RXR and VDR agonists while no significative difference was observed after treatment by the RAR agonist or by any combination. In addition, over-expression of NCoA4 induces a slow down of differentiation, as shown by expression of CD11b and CD14 myelomonocytic markers. Thus, in U-NCoA4, except for the RAR agonist, treatment for 72 hours corresponds to treatment for 48 hours levels of U937 cells. To conclude, in term of growth arrest, NCoA4 over-expressing cells are particularly sensitive to RXR and VDR agonists. Thus, natural ligands present in the culture medium might reduce or delay proliferation, inducing the same effect on differentiation. In order to have a large view of networks, transcriptome of U-NCoA4 was analyzed by real time PCR on Low Density Array composed of a hundred messengers extracted from U937 SAGE libraries. Analysis is currently in progress.

Inhibition of Elastase or SDF-1/CXCR4 Axis Promotes Differentiation of Human AML Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1891-1891
Author(s):  
Sigal Tavor ◽  
Jasmine Jacob-Hirsch ◽  
Manny Eisenbach ◽  
Sigi Kay ◽  
Shoshana Baron ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Line ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Critical Role ◽  
Marker Genes ◽  
Granulocytic Differentiation ◽  
Elastase Inhibitor ◽  
Granule Proteins ◽  
Cxcr4 Axis

Abstract Elastase, along with other azurophil granule proteins like proteinase 3 regulates normal and leukemic granulopoiesis in an un-defined mechanism. We have recently showed that human acute myeloid leukemic (AML) cells constitutively express and secrete stromal derived factor 1 (SDF-1) dependent cell surface elastase, which regulates their migration and proliferation. To elucidate the molecular events and genes regulated by elastase and SDF-1/CXCR4 axis in AML cells, we examined gene expression of U937 AML cell line treated with neutralizing anti-CXCR4 Abs or elastase inhibitor (EI) compared to untreated cells, using DNA microarray technology. Unsupervised hierarchical clustering analysis showed very similar gene expression profiles of EI and anti CXCR4 Abs treated cells as compared to control. 230 of 8400 genes interrogated were repressed, and 164 were induced after culturing AML cells in the presence of EI or anti CXCR4 Abs at different time points as compared to untreated cells. Inhibition of elastase or CXCR4 was accompanied by down regulation of the transcripts of primary granule proteins. Functional classification of elastase or SDF-1/CXCR4 axis regulated genes revealed downregulation of HOXA9, HOXA10, ETS2, as well as other transcription factors that are over expressed in AML and are important for the development of leukemia. Whereas, transcriptional factors and regulators known to be induced during myeloid differentiation like C/EBPε, ID1, RUNX3 and HHEX were up-regulated in treated cells. Expression patterns of apoptosis genes indicated decline in death control by the p53 dependent pathway and a more prominent control by mitochondrial mediated apoptotic pathway like bcl2 related genes. In addition, receptors for interleukins, growth factors (G-CSFR and GM-CSF), complement component (C1QR1) were upregulated in the treated cells. In contrast, FLT-3, a growth factor receptor stimulating growth of early progenitor cells and AML blasts, was down regulated in AML cell treated with EI or anti CXCR4 Abs. These data were confirmed by real time PCR for selected marker genes of granulocytic differentiation. Interestingly, many of the differentially expressed genes were common to the transcriptional program of normal terminal granulocytic differentiation (Theilgaard-Monch & Borregarrd 2005. Blood 105:1785) suggesting that inhibition of elastase may induce differentiation in AML cells. Thus we further analyzed the effect of elastase inhibition on AML cell differentiation and growth. Treatment of HL60 AML cell line with EI triggered a proliferative arrest, apoptosis and mimicked terminal granulocytic differentiation, including morphologic changes, increased CD11b expression, and the ability to produce oxidative bursts. In summary, our study showed that inhibition of elastase or SDF-1/CXCR4 axis in AML cells affects similar pathways related to differentiation and malignant transformation, implying a critical role for those molecules in regulating leukemic development. Repression of elastase decreases proliferation and induces differentiation of AML cells, suggesting a potential new therapeutic approach for AML.

The AML1/ETO Target LAT2 Membrane Adaptor Molecule Is Regulated during Normal Monocytic Differentiation.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2401-2401
Author(s):  
Jesus Duque-Afonso ◽  
Leticia Solari ◽  
Michael Luebbert
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Cell Lines ◽  
U937 Cells ◽  
Monocytic Differentiation ◽  
Granulocytic Differentiation ◽  
Gm Csf ◽  
Adaptor Molecule ◽  
Cd34 Cells ◽  
Conditional Expression

Abstract LAT2 (NTAL/LAB/WBSCR5) is a 28 KDa membrane protein which acts as adaptor molecule in the signalling pathways of FcεR I, c-Kit, B cell and T cell receptor. Bone marrow-derived mast cells from knock-out (KO) mice are hyperresponsive to stimulation via FcεR I. Although LAT2 is highly expressed in B cells, no major changes were found in function or development of B cells from LAT2 KO mice. An autoimmunity syndrome in LAT2 KO mice is caused, at least in part, by hyperreactivity and higher proliferation of T cells. Previously, we showed that LAT2 mRNA is repressed in vivo by AML1/ETO which was confirmed by others in several large series of primary AML blasts. We wished to elucidate the possible role of LAT2 during the myelopoiesis. AML1/ETO was induced by Ponasterone A in an ecdysone-inducible system in U937 cells (9/14/18 cell line). AML bone marrow samples from 43 patients (pts) were analyzed for LAT2 expression. Several myeloid cell lines were treated either with ATRA, DMSO or PMA for 3 days. Normal CD34+ cells were differentiated ex vivo by G-CSF towards granulocytes and by GM-CSF plus IL-4 towards monocytes and dendritic cells. LAT2 expression was determined by Northern and Western blot. LAT2 protein was repressed not only in AML1/ETO positive primary AML blasts (6/6), but also in blasts from patients with deletions of chromosome 7 (3/4) and the t(15;17) (4/4); expression was moderate to high in AML blasts with normal karyotype (14/15). LAT2 was expressed in normal monocytes and even higher in alveolar macrophages but not in granulocytes of healthy donors. It was downregulated after ATRA-induced granulocytic differentiation of NB4, HL60 and U937 cells but upregulated after DMSO-induced granulocytic differentiation of HL60 cells and PMA-induced monocytic-macrophage differentiation of HL60, U937 and Kasumi-1 cells. In normal CD34+ cells, LAT2 was strongly induced 7 days after the addition of G-CSF and GM-CSF+IL4 respectively, but after 14 days it was downregulated (0.7 +/− 0.4-fold) by G-CSF-induced granulocytic differentiation and upregulated (5.8 +/− 2.8-fold) by GM-CSF+IL4-induced monocytic-DC differentiation. Conditional expression of AML1/ETO in 9/14/18-U937 cells partially inhibited the PMA- and vitamin D3-induced monocytic differentiation of these cells, as determined by FACS for CD11b and CD11c. In conclusion, LAT2 protein is strongly repressed by AML1/ETO in primary leukemias and is upregulated during the monocytic differentiation in several cell lines and normal CD34+ cells. Further studies in a LAT2 knock-down by shRNAs in U937 cells are warranted to functionally address its possible role in monocytic differentiation.

A HoxD11 Homeobox Gene Mutation Associated With Congenital Absent Radius But Without The Thrombocytopenia Of The TAR Syndrome Or a HoxA11 Mutation

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4837-4837
Author(s):  
Roger A. Fleischman
Keyword(s):  
Potential Role ◽  
Conflicts Of Interest ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Incomplete Penetrance ◽  
Potential Candidate ◽  
Negative Finding ◽  
Tar Syndrome ◽  
Absent Radius

HoxA11 and HoxD11 are homeobox genes critical for normal development of the forearm and thus are potential candidate genes for involvement in the pathogenesis of the thrombocytopenia/absent radius (TAR) syndrome. However, we previously reported an absence of coding sequence mutations in either HoxA11 or HoxD11 in a series of 10 unrelated TAR syndrome patients (Fleischman RA et al., Br J Haematol., 116:367-75, 2002). Despite this negative finding, interest in the potential role of homeobox genes in the TAR syndrome has been supported by a report of a HoxA11 mutation occurring in two kindreds with amegakaryocytic thrombocytopenia and radio-ulnar synostosis, a less pronounced more proximal pattern of radial malformation (Thompson AA and Nguyen LT. Nat Genet., 26:397-8, 2000). Unlike HoxA11, however, no mutations in the human HoxD11 gene have been described thus far that would help elucidate the potential role of this paralogous gene in megakaryopoiesis or the TAR syndrome. We now describe a novel mutation in human HoxD11 that results in a polyalanine sequence expansion, (GCG)6→ (GCG)8, and report that this mutation is associated with a unilateral absent radius in the affected propositus. A familial syndrome is suggested in this kindred, moreover, by the prior observation of a bilateral absent radius in a deceased maternal aunt. This mutation was not present in more than 100 unrelated normal subjects or 8 other unrelated individuals with sporadic absence of the radius. Two other living maternal relatives also carried the mutation but did not exhibit any radial defects, a finding consistent with autosomal dominance with incomplete penetrance, an inheritance pattern reported for short polyalanine expansion mutations in the related homeobox gene HoxD13 which cause synpolydactyly. In contrast to the reported HoxA11 mutation, however, neither the propositus nor the mutation carriers of this HoxD11 mutation exhibited thrombocytopenia or any other cytopenias or congenital defect. The results suggest that at least one class of mutation in human HoxD11 may be sufficient to cause an absent radius syndrome but unlike the reported HoxA11 mutation, does not adversely affect megakaryopoiesis. The findings further suggest that additional studies of the TAR syndrome may be necessary to exclude as yet undetected non-coding mutations in promoter or enhancer sequences that alter the expression of HoxA11, HoxD11 or other homeobox genes critical for radial development and/or megakaryopoiesis. This work was supported by a VA Merit Award. Disclosures: No relevant conflicts of interest to declare.

Eicosanoid regulation of angiogenesis: role of endothelial arachidonate 12-lipoxygenase

Blood ◽  
2000 ◽  
Vol 95 (7) ◽  
pp. 2304-2311
Author(s):  
Daotai Nie ◽  
Keqin Tang ◽  
Clement Diglio ◽  
Kenneth V. Honn
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Cell Line ◽  
Critical Role ◽  
Endothelial Cell Migration ◽  
Vascular Endothelial ◽  
12 Lipoxygenase

Angiogenesis, the formation of new capillaries from preexisting blood vessels, is a multistep, highly orchestrated process involving vessel sprouting, endothelial cell migration, proliferation, tube differentiation, and survival. Eicosanoids, arachidonic acid (AA)-derived metabolites, have potent biologic activities on vascular endothelial cells. Endothelial cells can synthesize various eicosanoids, including the 12-lipoxygenase (LOX) product 12(S)-hydroxyeicosatetraenoic acid (HETE). Here we demonstrate that endogenous 12-LOX is involved in endothelial cell angiogenic responses. First, the 12-LOX inhibitor, N-benzyl-N-hydroxy-5-phenylpentanamide (BHPP), reduced endothelial cell proliferation stimulated either by basic fibroblast growth factor (bFGF) or by vascular endothelial growth factor (VEGF). Second, 12-LOX inhibitors blocked VEGF-induced endothelial cell migration, and this blockage could be partially reversed by the addition of 12(S)-HETE. Third, pretreatment of an angiogenic endothelial cell line, RV-ECT, with BHPP significantly inhibited the formation of tubelike/cordlike structures within Matrigel. Fourth, overexpression of 12-LOX in the CD4 endothelial cell line significantly stimulated cell migration and tube differentiation. In agreement with the critical role of 12-LOX in endothelial cell angiogenic responses in vitro, the 12-LOX inhibitor BHPP significantly reduced bFGF-induced angiogenesis in vivo using a Matrigel implantation bioassay. These findings demonstrate that AA metabolism in endothelial cells, especially the 12-LOX pathway, plays a critical role in angiogenesis.

The Ig-like domain of human GM-CSF receptor α plays a critical role in cytokine binding and receptor activation

2010 ◽  
Vol 426 (3) ◽  
pp. 307-317 ◽  
Author(s):  
Shamaruh Mirza ◽  
Andrew Walker ◽  
Jinglong Chen ◽  
James M. Murphy ◽  
Ian G. Young
Keyword(s):  
Structural Alignment ◽  
Critical Role ◽  
Receptor Activation ◽  
Gm Csf ◽  
Macrophage Colony Stimulating Factor ◽  
Subsequent Activation ◽  
Macrophage Colony ◽  
Key Residues ◽  
Stimulating Factor

GM-CSF (granulocyte/macrophage colony-stimulating factor) is an important mediator of inducible haemopoiesis and inflammation, and has a critical role in the function of alveolar macrophages. Its clinical applications include the mobilization of haemopoietic progenitors, and a role as an immune stimulant and vaccine adjuvant in cancer patients. GM-CSF signals via a specific α receptor (GM-CSFRα) and the shared hβc (human common β-subunit). The present study has investigated the role of the Ig-like domain of GM-CSFRα in GM-CSF binding and signalling. Deletion of the Ig-like domain abolished direct GM-CSF binding and decreased growth signalling in the presence of hβc. To locate the specific residues in the Ig-like domain of GM-CSFRα involved in GM-CSF binding, a structural alignment was made with a related receptor, IL-13Rα1 (interleukin-13 receptor α1), whose structure and mode of interaction with its ligand has recently been elucidated. Mutagenesis of candidate residues in the predicted region of interaction identified Val51 and Cys60 as having critical roles in binding to the α receptor, with Arg54 and Leu55 also being important. High-affinity binding in the presence of hβc was strongly affected by mutation of Cys60 and was also reduced by mutation of Val51, Arg54 and Leu55. Of the four key residues, growth signalling was most severely affected by mutation of Cys60. The results indicate a previously unrecognized role for the Ig-like domain, and in particular Cys60, of GM-CSFRα in the binding of GM-CSF and subsequent activation of cellular signalling.

scholarly journals All-trans retinoic acid reverses phorbol ester resistance in a human myeloid leukemia cell line

Blood ◽  
1994 ◽  
Vol 83 (2) ◽  
pp. 490-496 ◽  
Author(s):  
KD Yang ◽  
T Mizobuchi ◽  
SM Kharbanda ◽  
R Datta ◽  
E Huberman ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Cell Line ◽  
Leukemia Cell Line ◽  
Nonspecific Esterase ◽  
Mrna Levels ◽  
Monocytic Differentiation ◽  
Granulocytic Differentiation ◽  
Protein Levels ◽  
Trans Retinoic Acid ◽  
All Trans Retinoic Acid

Treatment of human HL-60 leukemic cells with 12-O-tetradecanoylphorbol- 13-acetate (TPA) is associated with activation of protein kinase C (PKC) and induction of monocytic differentiation. An HL-60 variant cell line, termed HL-525, derived from long-term exposure to TPA (Homma et al, Proc Natl Acad Sci USA 83: 7316, 1986) is resistant to TPA-induced differentiation and displays decreased PKC beta expression compared with the HL-60 parent line. However, this variant exhibits features of granulocytic differentiation, including nitroblue tetrazolium reduction, when exposed to all-trans retinoic acid (ATRA). Whereas treatment of HL-525 cells with ATRA or TPA alone had no effect on features of monocytic differentiation, these agents in combination resulted in cellular adhesion, nonspecific esterase staining, and induction of the c-fms (monocyte growth factor receptor) gene. In order to measure PKC expression associated with the reversal of TPA resistance by ATRA, we exposed HL-525 cells to ATRA and analyzed PKC- mRNA and protein levels. Exposure of HL-525 cells to ATRA for 3 days resulted in induction of PKC beta transcripts, whereas there was little change in PKC alpha mRNA levels. ATRA treatment was also associated with an increase in PKC activity and an induction of cytosolic PKC beta protein levels. These findings are consistent with the hypothesis that ATRA reverses TPA resistance in HL-525 cells by enhancing the expression of PKC.

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