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Sadaf S, Nagarkoti S, Awasthi D, Singh AK, Srivastava RN, Kumar S, Barthwal MK, Dikshit M. nNOS induction and NOSIP interaction impact granulopoiesis and neutrophil differentiation by modulating nitric oxide generation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:119018. [PMID: 33771575 DOI: 10.1016/j.bbamcr.2021.119018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 02/26/2021] [Accepted: 03/19/2021] [Indexed: 12/15/2022]
Abstract
Nitric oxide (NO), a versatile free radical and a signalling molecule, plays an important role in the haematopoiesis, inflammation and infection. Impaired proliferation and differentiation of myeloid cells lead to malignancies and Hematopoietic deficiencies. This study was aimed to define the role of nNOS derived NO in neutrophil differentiation (in-vitro) and granulopoiesis (in-vivo) using multipronged approaches. The results obtained from nNOS over-expressing K562 cells revealed induction in C/EBPα derived neutrophil differentiation as evident by an increase in the expression of neutrophil specific cell surface markers, genes, transcription factors and functionality. nNOS mediated response also involved G-CSFR-STAT-3 axis during differentiation. Consistent increase in NO generation was observed during neutrophil differentiation of mice and human CD34+ HSPCs. Furthermore, granulopoiesis was abrogated in the nNOS inhibitor treated mice, depicting a decrease in the numbers of BM mature and progenitor neutrophils. Likewise, in vitro inhibition of nNOS in human CD34+ HSPCs indicated an indispensable role of nNOS in neutrophil differentiation. Expression of nNOS inhibitory protein, NOSIP was significantly and consistently decreased during the final stage of differentiation and was linked with the augmentation in NO release. Moreover, neutrophils from CML patients had more NOSIP and less NO generation as compared to the PMNs from healthy individuals. The present study thus indicates a critical role of nNOS, and its interaction with NOSIP during neutrophil differentiation. The study also highlights the importance of nNOS in the neutrophil progenitor proliferation and differentiation warranting investigations to assess its role in the haematopoiesis-related disorders.
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Affiliation(s)
- Samreen Sadaf
- Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Sheela Nagarkoti
- Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Deepika Awasthi
- Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | | | | | - Sachin Kumar
- Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India
| | | | - Madhu Dikshit
- Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow, India; Translational Health Science and Technology Institute, NCR Biotech Science Cluster, 3rd Milestone, Faridabad - Gurgaon Expressway, Faridabad, Haryana 121001, India.
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2
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Abdel-Azim H, Sun W, Wu L. Strategies to generate functionally normal neutrophils to reduce infection and infection-related mortality in cancer chemotherapy. Pharmacol Ther 2019; 204:107403. [PMID: 31470030 DOI: 10.1016/j.pharmthera.2019.107403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/19/2019] [Indexed: 02/08/2023]
Abstract
Neutrophils form an essential part of innate immunity against infection. Cancer chemotherapy-induced neutropenia (CCIN) is a condition in which the number of neutrophils in a patient's bloodstream is decreased, leading to increased susceptibility to infection. Granulocyte colony-stimulating factor (GCSF) has been the only approved treatment for CCIN over two decades. To date, CCIN-related infection and mortality remain a significant concern, as neutrophils generated in response to administered GCSF are functionally immature and cannot effectively fight infection. This review summarizes the molecular regulatory mechanisms of neutrophil granulocytic differentiation and innate immunity development, dissects the biology of GCSF in myeloid expansion, highlights the shortcomings of GCSF in CCIN treatment, updates the recent advance of a selective retinoid agonist that promotes neutrophil granulocytic differentiation, and evaluates the benefits of developing GCSF biosimilars to increase access to GCSF biologics versus seeking a new mode to fundamentally advance GCSF therapy for treatment of CCIN.
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Affiliation(s)
- Hisham Abdel-Azim
- Pediatric Hematology-Oncology, Blood and Marrow Transplantation, Children's Hospital Los Angeles Saban Research Institute, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Los Angeles, CA 90027, USA
| | - Weili Sun
- Pediatric Hematology-Oncology, City of Hope National Medical Center, 1500 E. Duarte road, Duarte, CA 91010, USA
| | - Lingtao Wu
- Research and Development, Therapeutic Approaches, 2712 San Gabriel Boulevard, Rosemead, CA 91770, USA.
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3
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The Ontogeny of a Neutrophil: Mechanisms of Granulopoiesis and Homeostasis. Microbiol Mol Biol Rev 2018; 82:82/1/e00057-17. [PMID: 29436479 DOI: 10.1128/mmbr.00057-17] [Citation(s) in RCA: 131] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Comprising the majority of leukocytes in humans, neutrophils are the first immune cells to respond to inflammatory or infectious etiologies and are crucial participants in the proper functioning of both innate and adaptive immune responses. From their initial appearance in the liver, thymus, and spleen at around the eighth week of human gestation to their generation in large numbers in the bone marrow at the end of term gestation, the differentiation of the pluripotent hematopoietic stem cell into a mature, segmented neutrophil is a highly controlled process where the transcriptional regulators C/EBP-α and C/EBP-ε play a vital role. Recent advances in neutrophil biology have clarified the life cycle of these cells and revealed striking differences between neonatal and adult neutrophils based on fetal maturation and environmental factors. Here we detail neutrophil ontogeny, granulopoiesis, and neutrophil homeostasis and highlight important differences between neonatal and adult neutrophil populations.
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Liu XF, Hummel M, Abecassis M. Epigenetic regulation of cellular and cytomegalovirus genes during myeloid cell development. ACTA ACUST UNITED AC 2017; 3. [PMID: 28707002 DOI: 10.18103/imr.v3i3.385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Myeloid cells are important cell types that carry human cytomegalovirus. Latent viral DNA is present in CD34+ progenitor cells and their derived monocytes. However, differentiation of latently infected monocytes to mature macrophages or dendritic cells causes reactivation of latent viruses. During hematopoietic development, pluripotent genes are repressed, and lineage specific genes are activated in a step-wise manner. This process is governed by cell-type specific chromatin states. Enhancers in the hematopoietic system are highly dynamic and established by pioneer (first tier) transcription factors (TFs), which set the stage for second and third tier TF binding. In this review, we examine the epigenetic mechanisms that regulate myeloid cell development, cell identity, and activation with a special focus on factors that regulate viral gene expression and the status of viral infection in myeloid cells.
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Affiliation(s)
- Xue-Feng Liu
- Comprehensive Transplant Center, Division of Organ Transplantation, Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611
| | - Mary Hummel
- Comprehensive Transplant Center, Division of Organ Transplantation, Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611
| | - Michael Abecassis
- Comprehensive Transplant Center, Division of Organ Transplantation, Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611
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Wang H, Bei L, Shah CA, Hu L, Eklund EA. HoxA10 Terminates Emergency Granulopoiesis by Increasing Expression of Triad1. THE JOURNAL OF IMMUNOLOGY 2015; 194:5375-87. [PMID: 25895533 DOI: 10.4049/jimmunol.1401909] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 03/18/2015] [Indexed: 01/19/2023]
Abstract
Expression of the E3 ubiquitin ligase Triad1 is greater in mature granulocytes than in myeloid progenitor cells. HoxA10 actives transcription of the gene encoding Triad1 (ARIH2) during myeloid differentiation, but the contribution of increased Triad1 expression to granulocyte production or function is unknown. Mice with bone marrow-specific disruption of the ARIH2 gene exhibit constitutive inflammation with tissue infiltration by granulocytes and B cells. In contrast, disruption of the HOXA10 gene in mice neither constitutively activates the innate immune response nor significantly alters steady-state granulopoiesis. This study explores the impact of HoxA10-induced Triad1 expression on emergency (stress) granulopoiesis. We found that mice with HOXA10 gene disruption exhibited an overwhelming and fatal emergency granulopoiesis response that was characterized by tissue infiltration with granulocytes, but reversed by re-expression of Triad1 in the bone marrow. We determined that HoxA9 repressed ARIH2 transcription in myeloid progenitor cells, antagonizing the effect of HoxA10 on Triad1 expression. Also, we found that differentiation-stage-specific ARIH2 transcription was regulated by the tyrosine phosphorylation states of HoxA9 and HoxA10. Our studies demonstrate a previously undescribed role for HoxA10 in terminating emergency granulopoiesis, suggesting an important contribution by Hox proteins to the innate immune response.
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Affiliation(s)
- Hao Wang
- Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611; and
| | - Ling Bei
- Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611; and Jesse Brown Veteran's Administration Medical Center, Chicago, IL 60612
| | - Chirag A Shah
- Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611; and
| | - Liping Hu
- Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611; and
| | - Elizabeth A Eklund
- Feinberg School of Medicine and Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, IL 60611; and Jesse Brown Veteran's Administration Medical Center, Chicago, IL 60612
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6
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Valiuliene G, Stirblyte I, Cicenaite D, Kaupinis A, Valius M, Navakauskiene R. Belinostat, a potent HDACi, exerts antileukaemic effect in human acute promyelocytic leukaemia cells via chromatin remodelling. J Cell Mol Med 2015; 19:1742-55. [PMID: 25864732 PMCID: PMC4511371 DOI: 10.1111/jcmm.12550] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 01/08/2015] [Indexed: 11/30/2022] Open
Abstract
Epigenetic changes play a significant role in leukaemia pathogenesis, therefore histone deacetylases (HDACis) are widely accepted as an attractive strategy for acute promyelocytic leukaemia (APL) treatment. Belinostat (Bel, PXD101), a hydroxamate-type HDACi, has proved to be a promising cure in clinical trials for solid tumours and haematological malignancies. However, insight into molecular effects of Bel on APL, is still lacking. In this study, we investigated the effect of Bel alone and in combination with differentiation inducer retinoic acid (RA) on human promyelocytic leukaemia NB4 and HL-60 cells. We found that treatment with Bel, depending on the dosage used, inhibits cell proliferation, whereas in combination with RA enhances and accelerates granulocytic leukaemia cell differentiation. We also evaluated the effect of used treatments with Bel and RA on certain epigenetic modifiers (HDAC1, HDAC2, PCAF) as well as cell cycle regulators (p27) gene expression and protein level modulation. We showed that Bel in combination with RA up-regulates basal histone H4 hyperacetylation level more strongly compared to Bel or RA alone. Furthermore, chromatin immunoprecipitation assay indicated that Bel induces the accumulation of hyperacetylated histone H4 at the p27 promoter region. Mass spectrometry analysis revealed that in control NB4 cells, hyperacetylated histone H4 is mainly found in association with proteins involved in DNA replication and transcription, whereas after Bel treatment it is found with proteins implicated in pro-apoptotic processes, in defence against oxidative stress and tumour suppression. Summarizing, our study provides some novel insights into the molecular mechanisms of HDACi Bel action on APL cells.
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Affiliation(s)
- Giedre Valiuliene
- Department of Molecular Cell Biology, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Ieva Stirblyte
- Department of Molecular Cell Biology, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Dovile Cicenaite
- Department of Molecular Cell Biology, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Algirdas Kaupinis
- Proteomics Centre, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Mindaugas Valius
- Proteomics Centre, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
| | - Ruta Navakauskiene
- Department of Molecular Cell Biology, Institute of Biochemistry, Vilnius University, Vilnius, Lithuania
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Ying M, Zhou X, Zhong L, Lin N, Jing H, Luo P, Yang X, Song H, Yang B, He Q. Bortezomib sensitizes human acute myeloid leukemia cells to all-trans-retinoic acid-induced differentiation by modifying the RARα/STAT1 axis. Mol Cancer Ther 2012; 12:195-206. [PMID: 23243061 DOI: 10.1158/1535-7163.mct-12-0433] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
All-trans-retinoic acid (ATRA) has held great promise for differentiation-based therapy but reportedly downregulates retinoic acid receptor-α (RARα) in a proteasome-dependent manner, which leads to decreased acute myeloid leukemia (AML) cell differentiation efficiency. Therefore, research strategies that seek to further sensitize cells to retinoids and extend the range of retinoid-affected myeloid malignancies beyond acute promyelocytic leukemia (APL) are key investigative avenues. Here, we show that bortezomib, the first proteasome inhibitor approved for newly diagnosed and relapsed multiple myeloma, exhibited strong synergism with ATRA to promote HL60 and NB4 AML cell differentiation. We observed that bortezomib sensitized AML cells to ATRA-induced morphologic, biochemical, and functional changes, indicative of myeloid differentiation without cell death. In addition, treatment of human leukemia HL60 xenografts with bortezomib and ATRA together did not increase bortezomib-induced progressive weight loss but resulted in significant tumor growth inhibition in addition to increased differentiation (P < 0.05). These enhanced differentiation effects were accompanied by RARα stabilization and STAT1 activation. Taken together, our study was the first to evaluate bortezomib and ATRA synergy in AML cell differentiation and to assess new opportunities for bortezomib and ATRA combination as a promising approach for future differentiation therapy.
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Affiliation(s)
- Meidan Ying
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Hangzhou 310058, China
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8
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Mora-Jensen H, Jendholm J, Fossum A, Porse B, Borregaard N, Theilgaard-Mönch K. Technical Advance: Immunophenotypical characterization of human neutrophil differentiation. J Leukoc Biol 2011; 90:629-34. [DOI: 10.1189/jlb.0311123] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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9
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Abstract
Neutrophil granules store proteins that are critically important for the neutrophil to move from the vascular bed to tissues and to kill microorganisms. This is illustrated in nature when individual proteins are deleted due to inherited mutations of their cognate genes, and such deficiencies result in the conditions leucocyte adhesion deficiency and chronic granulomatous disease. The granules of the neutrophil have traditionally been divided into two or three major types but are instead a continuum where several subtypes can be identified with differences in protein content and propensity for mobilization. This is explained by the 'targeting by timing hypothesis' which states that granules are filled with granule proteins that are synthesized at the time the granule is formed. The heterogeneity of granules arises because the synthesis of granule proteins is individually controlled and major differences exist in the timings of biosynthesis during granulocytopoiesis. This is largely controlled by gene transcription.
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Affiliation(s)
- M Häger
- Granulocyte Research Laboratory, Department of Haematology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
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10
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Halene S, Gaines P, Sun H, Zibello T, Lin S, Khanna-Gupta A, Williams SC, Perkins A, Krause D, Berliner N. C/EBPepsilon directs granulocytic-vs-monocytic lineage determination and confers chemotactic function via Hlx. Exp Hematol 2009; 38:90-103. [PMID: 19925846 DOI: 10.1016/j.exphem.2009.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Mutations in the CCAAT enhancer binding protein epsilon (C/EBPepsilon) gene have been identified in the cells of patients with neutrophil specific granule deficiency, a rare congenital disorder marked by recurrent bacterial infections. Their neutrophils, in addition to lacking specific granules required for normal respiratory burst activity, also lack normal phagocytosis and chemotaxis. Although the specific granule deficiency phenotype has been replicated in C/EBPepsilon(-/-) (knockout [KO]) mice, the mechanisms by which C/EBPepsilon mutations act to decrease neutrophil function are not entirely clear. MATERIALS AND METHODS In order to determine the role of C/EBPepsilon in neutrophil differentiation and migration, we generated immortalized progenitor cell lines from C/EBPepsilon KO and wild-type mice and performed expression and flow cytometric analysis and functional studies. RESULTS Expression of lineage-specific cell surface antigens on our in vitro differentiated cell lines revealed persistent expression of monocytic markers on KO granulocytes. We verified this in primary murine peripheral blood and bone marrow cells. In addition, KO bone marrow had an increase in immature myeloid precursors at the common myeloid progenitor and granulocyte/monocyte progenitor levels, suggesting a critical role for C/EBPepsilon not only in granulocyte maturation beyond the promyelocyte stage, but also in the monocyte/granulocyte lineage decision. We found that restoration of Hlx (H2.0-like homeo box 1) expression, which was decreased in C/EBPepsilon KO cells, rescued chemotaxis, but not the other defects of C/EBPepsilon KO neutrophils. CONCLUSIONS We show two new regulatory functions of C/EBPepsilon in myelopoiesis: in the absence of C/EBPepsilon, there is not only incomplete differentiation of granulocytes, but myelopoiesis is disrupted with the appearance of an intermediate cell type with monocyte and granulocyte features, and the neutrophils have abnormal chemotaxis. Restoration of expression of Hlx provides partial recovery of function; it has no effect on neutrophil maturation, but can completely ameliorate the chemotaxis defect in C/EBPepsilon KO cells.
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Affiliation(s)
- Stephanie Halene
- Section of Hematology, Department of Internal Medicine and Yale Cancer Center, Yale University School of Medicine, New Haven, CT 06520-8073, USA.
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11
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Ernst J, Ghanem L, Bar-Joseph Z, McNamara M, Brown J, Steinman RA. IL-3 and oncogenic Abl regulate the myeloblast transcriptome by altering mRNA stability. PLoS One 2009; 4:e7469. [PMID: 19829692 PMCID: PMC2758590 DOI: 10.1371/journal.pone.0007469] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Accepted: 05/07/2009] [Indexed: 01/08/2023] Open
Abstract
The growth factor interleukin-3 (IL-3) promotes the survival and growth of multipotent hematopoietic progenitors and stimulates myelopoiesis. It has also been reported to oppose terminal granulopoiesis and to support leukemic cell growth through autocrine or paracrine mechanisms. The degree to which IL-3 acts at the posttranscriptional level is largely unknown. We have conducted global mRNA decay profiling and bioinformatic analyses in 32Dcl3 myeloblasts indicating that IL-3 caused immediate early stabilization of hundreds of transcripts in pathways relevant to myeloblast function. Stabilized transcripts were enriched for AU-Response elements (AREs), and an ARE-containing domain from the interleukin-6 (IL-6) 3′-UTR rendered a heterologous gene responsive to IL-3-mediated transcript stabilization. Many IL-3-stabilized transcripts had been associated with leukemic transformation. Deregulated Abl kinase shared with IL-3 the ability to delay turnover of transcripts involved in proliferation or differentiation blockade, relying, in part, on signaling through the Mek/Erk pathway. These findings support a model of IL-3 action through mRNA stability control and suggest that aberrant stabilization of an mRNA network linked to IL-3 contributes to leukemic cell growth.
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Affiliation(s)
- Jason Ernst
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Boston, Massachusetts, United States of America
| | - Louis Ghanem
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States of America
| | - Ziv Bar-Joseph
- Department of Computer Science, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Michael McNamara
- Regional Oncology Department, The Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Jason Brown
- Oncology staff, Meadeville Medical Center, Meadevill, Pennsylvania, United States of America
| | - Richard A. Steinman
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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12
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Doulatov S, Notta F, Rice KL, Howell L, Zelent A, Licht JD, Dick JE. PLZF is a regulator of homeostatic and cytokine-induced myeloid development. Genes Dev 2009; 23:2076-87. [PMID: 19723763 DOI: 10.1101/gad.1788109] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A major question in hematopoiesis is how the system maintains long-term homeostasis whereby the generation of large numbers of differentiated cells is balanced with the requirement for maintenance of progenitor pools, while remaining sufficiently flexible to respond to periods of perturbed cellular output during infection or stress. We focused on the development of the myeloid lineage and present evidence that promyelocytic leukemia zinc finger (PLZF) provides a novel function that is critical for both normal and stress-induced myelopoiesis. During homeostasis, PLZF restricts proliferation and differentiation of human cord blood-derived myeloid progenitors to maintain a balance between the progenitor and mature cell compartments. Analysis of PLZF promoter-binding sites revealed that it represses transcription factors involved in normal myeloid differentiation, including GFI-1, C/EBPalpha, and LEF-1, and induces negative regulators DUSP6 and ID2. Loss of ID2 relieves PLZF-mediated repression of differentiation identifying it as a functional target of PLZF in myelopoiesis. Furthermore, induction of ERK1/2 by myeloid cytokines, reflective of a stress response, leads to nuclear export and inactivation of PLZF, which augments mature cell production. Thus, negative regulators of differentiation can serve to maintain developmental systems in a primed state, so that their inactivation by extrinsic signals can induce proliferation and differentiation to rapidly satisfy increased demand for mature cells.
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Affiliation(s)
- Sergei Doulatov
- Division of Cell and Molecular Biology, University Health Network, Toronto, Ontario M5G 1L7, Canada
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13
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Anaplasma phagocytophilum increases cathepsin L activity, thereby globally influencing neutrophil function. Infect Immun 2008; 76:4905-12. [PMID: 18765732 DOI: 10.1128/iai.00851-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis, is an unusual obligate intracellular pathogen that persists in neutrophils. A. phagocytophilum increases the binding of a repressor, CCAAT displacement protein (CDP), to the gp91(phox) promoter, thereby diminishing the host oxidative burst. We now show that A. phagocytophilum infection also enhances the binding of CDP to the promoters of human neutrophil peptide 1 and C/EBPepsilon--molecules important for neutrophil defense and maturation--suggesting that this is a general strategy used by this pathogen to alter polymorphonuclear leukocyte function. To explore the mechanism by which A. phagocytophilum increases CDP activity, we assessed the effects of this microbe on cathepsin L, a protease that cleaves CDP into a form with increased DNA binding ability. A. phagocytophilum infection resulted in elevated cathepsin L activity and the proteolysis of CDP. Blocking the action of cathepsin L with a chemical inhibitor or small interfering RNA targeting of this molecule caused a marked reduction in the degree of A. phagocytophilum infection. These data demonstrate that increasing cathepsin L activity is a strategy used by A. phagocytophilum to alter CDP activity and thereby globally influence neutrophil function. As therapeutic options for A. phagocytophilum and related organisms are limited, these results also identify a cellular pathway that may be targeted for the treatment of A. phagocytophilum infection.
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14
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Bernasconi P. Molecular pathways in myelodysplastic syndromes and acute myeloid leukemia: relationships and distinctions-a review. Br J Haematol 2008; 142:695-708. [DOI: 10.1111/j.1365-2141.2008.07245.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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Wang XS, Zhang JW. The microRNAs involved in human myeloid differentiation and myelogenous/myeloblastic leukemia. J Cell Mol Med 2008; 12:1445-55. [PMID: 18554315 PMCID: PMC3918060 DOI: 10.1111/j.1582-4934.2008.00386.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 06/05/2008] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs (miRNAs) are endogenously expressed, functional RNAs that interact with native coding mRNAs to cleave mRNA or repress translation. Several miRNAs contribute to normal haematopoietic processes and some miRNAs act both as tumour suppressors and oncogenes in the pathology of haematological malignancies. While most effort is engaged in identifying and investigating the target genes of miRNAs, miRNA gene promoter methylation or transcriptional regulation is another important field of investigation, since these two main mechanisms can form a regulatory circuit. This review focuses on recent researches on miRNAs with important roles in myeloid cells.
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Affiliation(s)
- Xiao-Shuang Wang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, The Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jun-Wu Zhang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, The Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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16
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Stern JL, Cao JZ, Xu J, Mocarski ES, Slobedman B. Repression of human cytomegalovirus major immediate early gene expression by the cellular transcription factor CCAAT displacement protein. Virology 2008; 378:214-25. [PMID: 18614194 DOI: 10.1016/j.virol.2008.05.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2007] [Revised: 05/13/2008] [Accepted: 05/22/2008] [Indexed: 01/19/2023]
Abstract
Initiation of human cytomegalovirus (HCMV) productive infection is dependent on the major immediate early (MIE) genes ie1 and ie2. Several putative binding sites for CCAAT displacement protein (CDP or CUX1) were identified within the MIE promoter/regulatory region. Binding assays demonstrated binding of CUX1 to MIE-region oligonucleotides containing the CUX1 core binding sequence ATCGAT and mutagenesis of this sequence abrogated CUX1 binding. Furthermore, CUX1 repressed expression of a luciferase reporter construct controlled by the MIE promoter, and mutation of CUX1 binding sites within the promoter diminished this repressive function of CUX1. In the context of virus infection of HEK293 cells transfected with the CUX1 expression vector, CUX1 showed evidence of association with the HCMV MIE regulatory region and inhibited the capacity of the virus to express ie1 and ie2 transcripts, suggesting that this cellular factor regulates MIE gene expression following virus entry. These data identify a role for CUX1 in repressing HCMV gene expression essential for initiation of the replicative cycle.
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Affiliation(s)
- J Lewis Stern
- Centre for Virus Research, Westmead Millennium Institute, PO Box 412, Westmead, New South Wales 2145, Australia
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17
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Sansregret L, Nepveu A. The multiple roles of CUX1: insights from mouse models and cell-based assays. Gene 2008; 412:84-94. [PMID: 18313863 DOI: 10.1016/j.gene.2008.01.017] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Revised: 01/18/2008] [Accepted: 01/21/2008] [Indexed: 01/19/2023]
Abstract
Cux (Cut homeobox) genes are present in all metazoans. Early reports described many phenotypes caused by cut mutations in Drosophila melanogaster. In vertebrates, CUX1 was originally characterized as the CCAAT-displacement protein (CDP). Another line of investigation revealed the presence of CUX1 within a multi-protein complex called the histone nuclear factor D (HiNF-D). Recent studies led to the identification of several CUX1 isoforms with distinct DNA binding and transcriptional properties. While the CCAAT-displacement activity was implicated in the transcriptional repression of several genes, some CUX1 isoforms were found to participate in the transcriptional activation of some genes. The expression and activity of CUX1 was shown to be regulated through the cell cycle and to be a target of TGF-beta signaling. Mechanisms of regulation include alternative transcription initiation, proteolytic processing, phosphorylation and acetylation. Cell-based assays have established a role for CUX1 in the control of cell cycle progression, cell motility and invasion. In the mouse, gene inactivation as well as over-expression in transgenic mice has revealed phenotypes in multiple organs and cell types. While some phenotypes could be explained by the presumed functions of CUX1 in the affected cells, other phenotypes invoked non-cell-autonomous effects that suggest regulatory functions with an impact on cell-cell interactions. The implication of CUX1 in cancer was suggested first from its over-expression in primary tumors and cancer cell lines and was later confirmed in mouse models.
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Ueda Y, Su Y, Richmond A. CCAAT displacement protein regulates nuclear factor-kappa beta-mediated chemokine transcription in melanoma cells. Melanoma Res 2007; 17:91-103. [PMID: 17496784 PMCID: PMC2665270 DOI: 10.1097/cmr.0b013e3280a60888] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Members of the nuclear factor-kappa beta (NF-kappaB) family maintain cellular homeostasis by enhancing the transcription of genes involved in inflammation, immune response, cell proliferation, and apoptosis. Melanoma tumor cells often express inflammatory mediators through enhanced activation of NF-kappaB. The NF-kappaB activation appears to result from the enhancer formation including NF-kappaB and lysine acetyl transferases such as p300, CREB (cyclic AMP-responsive element binding protein)-binding protein (CBP), and/or p300/CBP associating factor (PCAF). We observed that proteins expressed by Hs294T metastatic melanoma cells are highly acetylated compared with normal melanocytes, and dominant-negative PCAF reduced the basal and tumor necrosis factor-alpha-stimulated transcriptional activity of NF-kappaB. The promoter activity of NF-kappaB-regulated chemokines was also reduced by the expression of dominant-negative PCAF. The promoters of these chemokines contain a CCAAT displacement protein (CDP)-binding site near the NF-kappaB element. compared with vector-transduced cells, in CDP-transduced Hs294T cells: (i) over-expressed CDP bound efficiently to PCAF, (ii) tumor necrosis factor-alpha-stimulated chemokine expression and NF-kappaB-mediated transcription were reduced, and (iii) the binding of CBP to Rel A was reduced. These data suggest that CDP inhibits cytokine-induced NF-kappaB-regulated chemokine transcription. This study contributes to our understanding of the role of CDP in an enhanceosome of NF-kappaB-mediated chemokine transcription in human melanoma cells.
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Affiliation(s)
- Yukiko Ueda
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Yingjun Su
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
| | - Ann Richmond
- Department of Veterans Affairs, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Ma X, Renda MJ, Wang L, Cheng EC, Niu C, Morris SW, Chi AS, Krause DS. Rbm15 modulates Notch-induced transcriptional activation and affects myeloid differentiation. Mol Cell Biol 2007; 27:3056-64. [PMID: 17283045 PMCID: PMC1899951 DOI: 10.1128/mcb.01339-06] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
RBM15 is the fusion partner with MKL in the t(1;22) translocation of acute megakaryoblastic leukemia. To understand the role of the RBM15-MKL1 fusion protein in leukemia, we must understand the normal functions of RBM15 and MKL. Here, we show a role for Rbm15 in myelopoiesis. Rbm15 is expressed at highest levels in hematopoietic stem cells and at more moderate levels during myelopoiesis of murine cell lines and primary murine cells. Decreasing Rbm15 levels with RNA interference enhances differentiation of the 32DWT18 myeloid precursor cell line. Conversely, enforced expression of Rbm15 inhibits 32DWT18 differentiation. We show that Rbm15 alters Notch-induced HES1 promoter activity in a cell type-specific manner. Rbm15 inhibits Notch-induced HES1 transcription in nonhematopoietic cells but stimulates this activity in hematopoietic cell lines, including 32DWT18 and human erythroleukemia cells. Moreover, the N terminus of Rbm15 coimmunoprecipitates with RBPJkappa, a critical factor in Notch signaling, and the Rbm15 N terminus has a dominant negative effect, impairing activation of HES1 promoter activity by full-length-Rbm15. Thus, Rbm15 is differentially expressed during hematopoiesis and may act to inhibit myeloid differentiation in hematopoietic cells via a mechanism that is mediated by stimulation of Notch signaling via RBPJkappa.
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Affiliation(s)
- Xianyong Ma
- Yale University School of Medicine, Department of Laboratory Medicine, P.O. Box 208035, 333 Cedar Street, New Haven, CT 06520-8035, USA
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Sloand EM, Yong ASM, Ramkissoon S, Solomou E, Bruno TC, Kim S, Fuhrer M, Kajigaya S, Barrett AJ, Young NS. Granulocyte colony-stimulating factor preferentially stimulates proliferation of monosomy 7 cells bearing the isoform IV receptor. Proc Natl Acad Sci U S A 2006; 103:14483-8. [PMID: 16980411 PMCID: PMC1599987 DOI: 10.1073/pnas.0605245103] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Granulocyte colony-stimulating factor (GCSF) administration has been linked to the development of monosomy 7 in severe congenital neutropenia and aplastic anemia. We assessed the effect of pharmacologic doses of GCSF on monosomy 7 cells to determine whether this chromosomal abnormality developed de novo or arose as a result of favored expansion of a preexisting clone. Fluorescence in situ hybridization (FISH) of chromosome 7 was used to identify small populations of aneuploid cells. When bone marrow mononuclear cells from patients with monosomy 7 were cultured with 400 ng/ml GCSF, all samples showed significant increases in the proportion of monosomy 7 cells. In contrast, bone marrow from karyotypically normal aplastic anemia, myelodysplastic syndrome, or healthy individuals did not show an increase in monosomy 7 cells in culture. In bone marrow CD34 cells of patients with myelodysplastic syndrome and monosomy 7, GCSF receptor (GCSFR) protein was increased. Although no mutation was found in genomic GCSFR DNA, CD34 cells showed increased expression of the GCSFR class IV mRNA isoform, which is defective in signaling cellular differentiation. GCSFR signal transduction via the Jak/Stat system was abnormal in monosomy 7 CD34 cells, with increased phosphorylated signal transducer and activation of transcription protein, STAT1-P, and increased STAT5-P relative to STAT3-P. Our results suggest that pharmacologic doses of GCSF increase the proportion of preexisting monosomy 7 cells. The abnormal response of monosomy 7 cells to GCSF would be explained by the expansion of undifferentiated monosomy 7 clones expressing the class IV GCSFR, which is defective in signaling cell maturation.
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Affiliation(s)
- Elaine M Sloand
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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22
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Maitra U, Seo J, Lozano MM, Dudley JP. Differentiation-induced cleavage of Cutl1/CDP generates a novel dominant-negative isoform that regulates mammary gene expression. Mol Cell Biol 2006; 26:7466-78. [PMID: 17015474 PMCID: PMC1636867 DOI: 10.1128/mcb.01083-06] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cutl1/CCAAT displacement protein (CDP) is a transcriptional repressor of mouse mammary tumor virus (MMTV), a betaretrovirus that is a paradigm for mammary-specific gene regulation. Virgin mammary glands have high levels of full-length CDP (200 kDa) that binds to negative regulatory elements (NREs) to repress MMTV transcription. During late pregnancy, full-length CDP levels decline, and a 150-kDa form of CDP (CDP150) appears concomitantly with a decline in DNA-binding activity for the MMTV NREs and an increase in viral transcripts. Developmental regulation of CDP was recapitulated in the normal mammary epithelial line, SCp2. Western blotting of tissue and SCp2 nuclear extracts confirmed that CDP150 lacks the C terminus. Transfection of tagged full-length and mutant cDNAs into SCp2 cells and use of a cysteine protease inhibitor demonstrated that CDP is proteolytically processed within the homeodomain to remove the C terminus during differentiation. Mixing of virgin and lactating mammary extracts or transfection of mutant CDP cDNAs missing the homeodomain into cells containing full-length CDP also abrogated NRE binding. Loss of DNA binding correlated with increased expression of MMTV and other mammary-specific genes, indicating that CDP150 is a developmentally induced dominant-negative protein. Thus, a novel posttranslational process controls Cutl1/CDP activity and gene expression in the mammary gland.
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Affiliation(s)
- Urmila Maitra
- Section of Molecular Genetics and Microbiology, The University of Texas at Austin, 24th and Speedway, ESB 226, Austin, TX 78712-0162, USA
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Teng CT. Factors regulating lactoferrin gene expressionThis paper is one of a selection of papers published in this Special Issue, entitled 7th International Conference on Lactoferrin: Structure, Function, and Applications, and has undergone the Journal's usual peer review process. Biochem Cell Biol 2006; 84:263-7. [PMID: 16936795 DOI: 10.1139/o06-034] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Regulation of gene expression by nuclear receptors and transcription factors involves the concerted action of multiple proteins. The process of transcriptional activation involves chromatin modification, nuclear receptor or transcription factor binding to the response element of the promoter, and coregulator recruitment. Despite advances in knowledge pertaining to the molecular mechanisms of gene regulation overall, there is very limited information available on the molecular mechanism of lactoferrin gene regulation. This review will outline novel information relating to general gene regulation and will discuss the current understanding of the regulation of lactoferrin gene expression by nuclear receptors and transcription factors.
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Affiliation(s)
- Christina T Teng
- Gene Regulation Section, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, NC 27709, USA.
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Schuster MB, Porse BT. C/EBPalpha: a tumour suppressor in multiple tissues? Biochim Biophys Acta Rev Cancer 2006; 1766:88-103. [PMID: 16616425 DOI: 10.1016/j.bbcan.2006.02.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Revised: 02/23/2006] [Accepted: 02/28/2006] [Indexed: 11/22/2022]
Abstract
The CCATT/enhancer binding protein alpha, C/EBPalpha, is a key transcription factor involved in late differentiation events of several cell types. Besides acting as a classical transcription factor, C/EBPalpha is also a well-characterized inhibitor of mitotic growth in most cell lines tested. In line with its anti-mitotic properties, C/EBPalpha has been shown to interact with, and alter the activities of, several cell cycle related proteins and a number of models as to the mechanistics of C/EBPalpha-mediated growth repression have been proposed. More recently, several reports have indicated that C/EBPalpha acts as a tumour suppressor in the hematopoietic system and that mutation within C/EBPalpha is sufficient to induce tumourigenesis. Here, we will review these data and probe the possibility that C/EBPalpha also act as a tumour suppressor in other C/EBPalpha-expressing tissues.
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Affiliation(s)
- Mikkel Bruhn Schuster
- Section for Gene Therapy Research, Department of Clinical Biochemistry, Copenhagen University Hospital, Juliane Maries Vej 20-9322, DK2100 Copenhagen, Denmark
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25
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Fazi F, Rosa A, Fatica A, Gelmetti V, De Marchis ML, Nervi C, Bozzoni I. A minicircuitry comprised of microRNA-223 and transcription factors NFI-A and C/EBPalpha regulates human granulopoiesis. Cell 2006; 123:819-31. [PMID: 16325577 DOI: 10.1016/j.cell.2005.09.023] [Citation(s) in RCA: 779] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Revised: 07/22/2005] [Accepted: 09/12/2005] [Indexed: 10/25/2022]
Abstract
MicroRNAs play important roles in cell differentiation by acting as translational inhibitors of specific target genes. Here we show that human granulocytic differentiation is controlled by a regulatory circuitry involving miR-223 and two transcriptional factors, NFI-A and C/EBPalpha. The two factors compete for binding to the miR-223 promoter: NFI-A maintains miR-223 at low levels, whereas its replacement by C/EBPalpha, following retinoic acid (RA)-induced differentiation, upregulates miR-223 expression. The competition by C/EBPalpha and the granulocytic differentiation are favored by a negative-feedback loop in which miR-223 represses NFI-A translation. In line with this, both RNAi against NFI-A and ectopic expression of miR-223 in acute promyelocytic leukemia (APL) cells enhance differentiation, whereas miR-223 knockdown inhibits the differentiation response to RA. Altogether, our data indicate that miR-223 plays a crucial role during granulopoiesis and point to the NFI-A repression as an important molecular pathway mediating gene reprogramming in this cell lineage.
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Affiliation(s)
- Francesco Fazi
- Department of Histology and Medical Embryology, University of Rome La Sapienza and San Raffaele Biomedical Science Park of Rome, Via di Castel Romano 100, 00128, Rome, Italy
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Fatica A, Rosa A, Fazi F, Ballarino M, Morlando M, De Angelis FG, Caffarelli E, Nervi C, Bozzoni I. MicroRNAs and hematopoietic differentiation. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2006; 71:205-10. [PMID: 17381298 DOI: 10.1101/sqb.2006.71.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The discovery of microRNAS (miRNAs) and of their mechanism of action has provided some very new clues on how gene expression is regulated. These studies established new concepts on how posttranscriptional control can fine-tune gene expression during differentiation and allowed the identification of new regulatory circuitries as well as factors involved therein. Because of the wealth of information available about the transcriptional and cellular networks involved in hematopoietic differentiation, the hematopoietic system is ideal for studying cell lineage specification. An interesting interplay between miRNAs and lineage-specific transcriptional factors has been found, and this can help us to understand how terminal differentiation is accomplished.
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Affiliation(s)
- A Fatica
- Institute Pasteur Cenci-Bolognetti, Department of Genetics and Molecular Biology and I.B.P.M., University of Rome La Sapienza, Rome, Italy
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Qian J, Chen Z, Lin J, Wang W, Cen J. Decreased expression of CCAAT/enhancer binding protein zeta (C/EBPzeta) in patients with different myeloid diseases. Leuk Res 2005; 29:1435-41. [PMID: 16005964 DOI: 10.1016/j.leukres.2005.05.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 05/12/2005] [Indexed: 11/25/2022]
Abstract
CCAAT/enhancer binding proteins (C/EBPs) are a family of transcription factors that have been implicated in diverse cellular functions such as cellular differentiation and proliferation, and inflammatory processes. C/EBPzeta, also known as GADD153, CHOP10, and DDIT3 has been found associated with the development of myxoid liposarcoma and the progression of melanoma. To investigate the correlation of C/EBPzeta transcript levels with the development of leukemia, samples from 187 patients with myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML) were examined for C/EBPzeta mRNA using real-time quantitative PCR (RQ-PCR). RQ-PCR analysis demonstrated the median levels of C/EBPzeta were significantly decreased in MDS, AML, and CML patients compared with normal controls (1.40, 0.96, 2.60 versus 14.69, P<0.0001). Significant differences were also observed between patients with CML and with AML or MDS. These results suggest that the insufficient dosage of C/EBPzeta might be involved in the development of leukemia.
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Affiliation(s)
- Jun Qian
- The Department of Hematology, The First People's Hospital of Zhenjiang, Zhenjiang, Jiangsu 212002, PR China
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28
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Wang L, Arcasoy MO, Watowich SS, Forget BG. Cytokine signals through STAT3 promote expression of granulocyte secondary granule proteins in 32D cells. Exp Hematol 2005; 33:308-17. [PMID: 15730854 PMCID: PMC2388245 DOI: 10.1016/j.exphem.2004.11.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 11/19/2004] [Accepted: 11/22/2004] [Indexed: 01/19/2023]
Abstract
OBJECTIVE In a previous study, we showed that activation of a transfected human erythropoietin receptor (EPOR) in the murine myeloid cell line 32D resulted in the development of morphologic features of granulocytic differentiation and expression of the neutrophil primary granule protein myeloperoxidase. We now studied if EPOR signaling could also mediate secondary granule protein gene expression and investigated the signal transduction requirements for induction of secondary granule gene expression in 32D cells. MATERIALS AND METHODS Wild-type and variant 32D cells expressing normal or chimeric EPORs or receptors for granulocyte colony-stimulating factor (G-CSFRs) were stimulated with EPO or G-CSF and the expression of granulocyte-specific genes was analyzed by Northern blot analysis. To determine the signaling mechanisms required for secondary granule protein gene induction, the activation of STAT pathways following growth factor stimulation was studied by Western blot analysis. RESULTS We found that EPO treatment of 32D cells engineered to express EPOR did not result in induction of the secondary granule protein genes encoding lactoferrin and 24p3 lipocalin, the mouse homolog of human N-Gal, or the myeloid transcription factor C/EBPepsilon. Replacement of the intracellular domain of EPOR with the intracellular domain of G-CSFR in a chimeric receptor was associated with EPO-mediated induction of lactoferrin, 24p3 lipocalin, and C/EBPepsilon genes. We found that STAT3 phosphorylation was mediated by the intracellular domain of G-CSFR, but not EPOR. Replacement of one or two of the STAT5 binding sites in the intracytoplasmic domain of the EPOR with STAT3 binding sites resulted in EPO-mediated STAT3 activation and a marked increase in the expression of the 24p3 lipocalin gene. Knockdown of STAT3 protein levels with siRNA caused significant decrease in 24p3 lipocalin gene induction. CONCLUSION These results indicate that EPOR signaling cannot substitute for G-CSFR signaling to stimulate secondary granule protein gene expression in 32D cells. In addition, STAT3 is a critical mediator of 24p3 lipocalin gene expression in these cells.
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Affiliation(s)
- Lei Wang
- Department of Medicine, Yale University School of Medicine, New Haven, Conn., USA
| | - Murat O. Arcasoy
- Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Stephanie S. Watowich
- Department of Immunology, University of Texas, MD Anderson Cancer Center, Houston, Tex., USA
| | - Bernard G. Forget
- Department of Medicine, Yale University School of Medicine, New Haven, Conn., USA
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Rosmarin AG, Yang Z, Resendes KK. Transcriptional regulation in myelopoiesis: Hematopoietic fate choice, myeloid differentiation, and leukemogenesis. Exp Hematol 2005; 33:131-43. [PMID: 15676205 DOI: 10.1016/j.exphem.2004.08.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Accepted: 08/06/2004] [Indexed: 12/24/2022]
Abstract
Myeloid cells (granulocytes and monocytes) are derived from multipotent hematopoietic stem cells. Gene transcription plays a critical role in hematopoietic differentiation. However, there is no single transcription factor that is expressed exclusively by myeloid cells and that, alone, acts as a "master" regulator of myeloid fate choice. Rather, myeloid gene expression is controlled by the combinatorial effects of several key transcription factors. Hematopoiesis has traditionally been viewed as linear and hierarchical, but there is increasing evidence of plasticity during blood cell development. Transcription factors strongly influence cellular lineage during hematopoiesis and expression of some transcription factors can alter the fate of developing hematopoietic progenitor cells. PU.1 and CCAAT/enhancer-binding protein alpha (C/EBPalpha) regulate expression of numerous myeloid genes, and gene disruption studies have shown that they play essential, nonredundant roles in myeloid cell development. They function in cooperation with other transcription factors, co-activators, and co-repressors to regulate genes in the context of chromatin. Because of their essential roles in regulating myeloid genes and in myeloid cell development, it has been hypothesized that abnormal expression of PU.1 and C/EBPalpha would contribute to aberrant myeloid differentiation, i.e. acute leukemia. Such a direct link has been elusive until recently. However, there is now persuasive evidence that mutations in both PU.1 and C/EBPalpha contribute directly to development of acute myelogenous leukemia. Thus, normal myeloid development and acute leukemia are now understood to represent opposite sides of the same hematopoietic coin.
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Affiliation(s)
- Alan G Rosmarin
- Department of Medicine, Brown Medical School, Providence, RI, USA.
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Khanna-Gupta A, Zibello T, Idone V, Sun H, Lekstrom-Himes J, Berliner N. Human neutrophil collagenase expression is C/EBP-dependent during myeloid development. Exp Hematol 2005; 33:42-52. [PMID: 15661397 DOI: 10.1016/j.exphem.2004.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 09/27/2004] [Accepted: 09/27/2004] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Human neutrophil collagenase (HNC) is one of several secondary granule proteins (SGP) expressed late in the myeloid maturation pathway. SGPs are encoded by unlinked and functionally diverse genes that are hypothesized to be coordinately regulated at the transcriptional level and demonstrate uniform dysregulation in leukemic cells. In support of the hypothesis that tissue and stage-specific expression of SGP genes is regulated by shared factor(s), we sought to identify factors responsible for positive regulation of the SGP genes. METHODS Using 5' deletion analysis, we identified a minimal HNC promoter located within the first 193 bp upstream of the transcription start site. Three CCAAT enhancer binding protein (C/EBP) sites were identified within this region and their functional importance was confirmed by mutational analysis, gel retardation, and oligonucleotide pulldown assays. Using chromatin immunoprecipitation (ChIP), we demonstrated that C/EBPalpha binds to the SGP gene promoters lactoferrin and HNC in nonexpressing cells. Upon induction of maturation, C/EBPalpha binds to these promoters and this binding correlates with the expression of both SGP genes. CONCLUSION We conclude that in the later stages of myeloid development, SGP genes are coordinately upregulated, and that members of the C/EBP family of transcription factors, in particular C/EBPalpha and C/EBPepsilon, play specific and unique roles in upregulating their expression.
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Affiliation(s)
- Arati Khanna-Gupta
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
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Kim J, Sharma S, Li Y, Cobos E, Palvimo JJ, Williams SC. Repression and coactivation of CCAAT/enhancer-binding protein epsilon by sumoylation and protein inhibitor of activated STATx proteins. J Biol Chem 2005; 280:12246-54. [PMID: 15661739 DOI: 10.1074/jbc.m413771200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CCAAT/enhancer-binding protein epsilon (C/EBPepsilon) is a neutrophil-specific transcription factor whose activity is controlled by juxtaposed activating and regulatory domains. We previously determined that the function of the major regulatory domain (RD1) in C/EBPepsilon was dependent on the integrity of a five-amino acid motif that was identical to the recognition site for members of the small ubiquitin-like modifier (SUMO) family of ubiquitin-related proteins. We show here that the SUMO attachment site (the regulatory domain motif) is necessary and sufficient both for the intrinsic inhibitory function of RD1 and for coactivation by PIASxalpha and PIASxbeta, two members of the protein inhibitor of activated STAT (PIAS) family of SUMO E3 ligases. PIASxbeta was a more potent coactivator than PIASxalpha of both full-length C/EBPepsilon and fusion proteins containing the N-terminal portion of C/EBPepsilon, whereas PIASxalpha was more active on fusion proteins containing a heterologous activation domain. Two modes of coactivation were observed, one that was dependent on the integrity of the RING finger (RF) domain and was shared by both PIASxalpha and PIASxbeta and a second mode that was independent of the RF and was only observed with PIASxbeta. Sumoylation of C/EBPepsilon was enhanced by coexpression of PIASxalpha, suggesting that this modification is associated with the enhanced activity of the target protein. These results suggest that a complex interplay of accessory factors, including SUMO and PIAS proteins, modulates the activity of C/EBPepsilon.
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Affiliation(s)
- Jinyong Kim
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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32
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Yang L, Zhao H, Li SW, Ahrens K, Collins C, Eckenrode S, Ruan QG, McIndoe RA, She JX. Gene expression profiling during all-trans retinoic acid-induced cell differentiation of acute promyelocytic leukemia cells. J Mol Diagn 2004; 5:212-21. [PMID: 14573779 PMCID: PMC1907337 DOI: 10.1016/s1525-1578(10)60476-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Using cDNA microarrays we determined the gene expression patterns in the human acute promyelocytic leukemia (APL) cell line NB4 during all-trans retinoic acid (ATRA)-induced differentiation. We analyzed the expression of 12,288 genes in the NB4 cells after 12 hours, 24 hours, 48 hours, 72 hours, and 96 hours of ATRA exposure. During this time course, we found 168 up-regulated and more than 179 down-regulated genes, most of which have not been reported before. Many of the altered genes encode products that participate in signaling pathways, cell differentiation, programmed cell death, transcription regulation, and production of cytokines and chemokines. Of interest, the CD52 and protein kinase A regulatory subunit alpha (PKA-Rlalpha) genes, whose products are being used as therapeutic targets for certain human neoplasias in currently ongoing clinical trials, were among the genes observed to be markedly up-regulated after ATRA treatment. The present study provides valuable data to further understand the mechanism of ATRA-induced APL cell differentiation and suggests potential therapeutic alternatives for this leukemia.
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Affiliation(s)
- Lijun Yang
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida 32610, USA.
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Zhu Q, Maitra U, Johnston D, Lozano M, Dudley JP. The homeodomain protein CDP regulates mammary-specific gene transcription and tumorigenesis. Mol Cell Biol 2004; 24:4810-23. [PMID: 15143175 PMCID: PMC416401 DOI: 10.1128/mcb.24.11.4810-4823.2004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The CCAAT-displacement protein (CDP) has been implicated in developmental and cell-type-specific regulation of many cellular and viral genes. We previously have shown that CDP represses mouse mammary tumor virus (MMTV) transcription in tissue culture cells. Since CDP-binding activity for the MMTV long terminal repeat declines during mammary development, we tested whether binding mutations could alter viral expression. Infection of mice with MMTV proviruses containing CDP binding site mutations elevated viral RNA levels in virgin mammary glands and shortened mammary tumor latency. To determine if CDP has direct effects on MMTV transcription rather than viral spread, virgin mammary glands of homozygous CDP-mutant mice lacking one of three Cut repeat DNA-binding domains (DeltaCR1) were examined by reverse transcription-PCR. RNA levels of endogenous MMTV as well as alpha-lactalbumin and whey acidic protein (WAP) were elevated. Heterozygous mice with a different CDP mutation that eliminated the entire C terminus and the homeodomain (DeltaC mice) showed increased levels of MMTV, beta-casein, WAP, and alpha-lactalbumin RNA in virgin mammary glands compared to those from wild-type animals. No differences in amounts of WDNM1, epsilon-casein, or glyceraldehyde-3-phosphate dehydrogenase RNA were observed between the undifferentiated mammary tissues from wild-type and mutant mice, indicating the specificity of this effect. These data show independent contributions of different CDP domains to negative regulation of differentiation-specific genes in the mammary gland.
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Affiliation(s)
- Quan Zhu
- Section of Molecular Genetics and Microbiology, The University of Texas at Austin, One University Station, A5000, 24th and Speedway, ESB 226, Austin, TX 78712-0162, USA
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Maun NA, Gaines P, Khanna-Gupta A, Zibello T, Enriquez L, Goldberg L, Berliner N. G-CSF signaling can differentiate promyelocytes expressing a defective retinoic acid receptor: evidence for divergent pathways regulating neutrophil differentiation. Blood 2003; 103:1693-701. [PMID: 14604978 DOI: 10.1182/blood-2002-10-3247] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Several lines of investigation suggest that granulocyte colony-stimulating factor (G-CSF) augments all-trans retinoic acid (ATRA)-induced neutrophil differentiation in acute promyelocytic leukemia (APL). We sought to characterize the relationship between G-CSF- and ATRA-mediated neutrophil differentiation. We established a G-CSF receptor-transduced promyelocytic cell line, EPRO-Gr, derived from the granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent EPRO cell line harboring a dominant-negative retinoic acid receptor alpha (RARalpha). In EPRO-Gr, neutrophil differentiation occurs either in GM-CSF upon addition of ATRA or upon induction with G-CSF alone. Transient transfection of EPRO-Gr cells with a RARE-containing reporter plasmid demonstrates increased activity in the presence of ATRA, but not G-CSF, while STAT3 phosphorylation occurs only in response to G-CSF. This suggests that ATRA-mediated differentiation of EPRO-Gr cells occurs via a RARE-dependent, STAT3-independent pathway, while G-CSF-mediated differentiation occurs via a RARE-independent, STAT3-dependent pathway. ATRA and G-CSF thus regulate differentiation by divergent pathways. We characterized these pathways in the APL cell line, NB4. ATRA induction of NB4 cells resulted in morphologic differentiation and up-regulation of C/EBPepsilon and G-CSFR, but not in STAT3 phosphorylation. The addition of G-CSF with ATRA during NB4 induction resulted in STAT3 phosphorylation but did not enhance differentiation. These results may elucidate how G-CSF and ATRA affect the differentiation of primary and ATRA-resistant APL cells.
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Affiliation(s)
- Noel A Maun
- Section of Hematology, Yale University School of Medicine, New Haven, CT 06510, USA
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Bjerregaard MD, Jurlander J, Klausen P, Borregaard N, Cowland JB. The in vivo profile of transcription factors during neutrophil differentiation in human bone marrow. Blood 2003; 101:4322-32. [PMID: 12560239 DOI: 10.1182/blood-2002-03-0835] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In vivo distribution of myeloid transcription factors during granulopoiesis was investigated by Northern and Western blotting in 3 neutrophil precursor populations from human bone marrow: immature (myeloblasts [MBs] and promyelocytes [PMs]); intermediate mature (myelocytes [MCs] and metamyelocytes [MMs]); and mature neutrophil cells (band cells [BCs] and segmented neutrophil cells [SCs]). Nonneutrophil cells were removed with magnetic-bead-coupled antibodies against CD2, CD3, CD14, CD19, CD56, CD61, glycophorin-A, and CD49d (BCs/SCs) before RNA and protein extraction. Polymorphonuclear neutrophils (PMNs) from peripheral blood depleted with anti-CD49d antibodies were also included. Expression of acute myeloid leukemia 1b (AML-1b), c-myb, GATA-1, and CCAAT/enhancer binding protein gamma (C/EBP-gamma) was seen primarily in MBs/PMs, and little expression was found in more mature cells. The level of C/EBP-alpha was constant in the bone marrow-derived cells and decreased in PMNs. C/EBP-epsilon was found primarily in MCs/MMs and was almost absent in more mature cells. Expression of C/EBP-beta, C/EBP-delta, and C/EBP-zeta was observed from the MC/MM stage onward, with peak levels in the most mature cells. The amount of PU.1 increased throughout maturation whereas the level of Elf-1 reached a nadir in MCs/MMs The PU.1 coactivator c-jun and c-jun's dimerization partner c-fos were both detectable in MCs/MMs and increased in amount with maturity. CCAAT displacement protein (CDP) was found at comparable levels at all stages of differentiation. This demonstrates a highly individualized expression of the transcription factors, which can form the basis for the heterogeneous expression of granule proteins during granulopoiesis and cell cycle arrest in metamyelocytes.
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Khanna-Gupta A, Zibello T, Sun H, Gaines P, Berliner N. Chromatin immunoprecipitation (ChIP) studies indicate a role for CCAAT enhancer binding proteins alpha and epsilon (C/EBP alpha and C/EBP epsilon ) and CDP/cut in myeloid maturation-induced lactoferrin gene expression. Blood 2003; 101:3460-8. [PMID: 12522000 DOI: 10.1182/blood-2002-09-2767] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In vitro models of granulopoiesis involving the inducible expression of either CCAAT enhancer binding protein alpha (C/EBP alpha) or C/EBP epsilon in myeloid cells have been shown to lead to the induction of a granulocytic maturation program accompanied by the expression of myeloid-specific genes. Since members of the C/EBP family of transcription factors recognize and bind to similar DNA-binding motifs, it has been difficult to elucidate the specific role of each of the C/EBP family members in eliciting myeloid gene expression. In order to address this issue, we focused on the expression of the lactoferrin (LF) gene. LF expression is transcriptionally regulated in a C/EBP-dependent manner in myeloid cells. Using chromatin immunoprecipitation (ChIP) analysis we demonstrate that C/EBP alpha binds to the LF promoter in nonexpressing cells. Upon induction of maturation, C/EBP epsilon binds to the LF promoter, which correlates with LF expression. Lack of LF expression in the acute promyelocytic leukemia cell line NB4, which harbors the t(15;17) translocation, cannot be correlated with aberrant binding at the C/EBP site in the LF promoter. It is, however, associated with the persistent binding of the silencer CCAAT displacement protein (CDP/cut) to the LF promoter in these cells. We conclude that C/EBP alpha, C/EBP epsilon, and CDP/cut all play definitive roles in regulating late gene expression during normal myeloid development.
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Affiliation(s)
- Arati Khanna-Gupta
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06510, USA
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Zhang P, Nelson E, Radomska HS, Iwasaki-Arai J, Akashi K, Friedman AD, Tenen DG. Induction of granulocytic differentiation by 2 pathways. Blood 2002; 99:4406-12. [PMID: 12036869 DOI: 10.1182/blood.v99.12.4406] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The CCAAT enhancer binding protein alpha (C/EBP alpha) transcription factor plays a critical role in granulocytopoiesis. Mice with a disruption of the C/EBP alpha gene demonstrate an early block in granulocytic differentiation, and disruption of C/EBP alpha function is a common theme in many types of human acute myelogenous leukemia, which is characterized by a block in myeloid development. To characterize further the nature of this block, we derived cell lines from the fetal liver of C/EBP alpha-deficient animals. These lines resembled morphologically the immature myeloid blasts observed in C/EBP alpha(-/-) fetal livers and did not express messenger RNA encoding early myeloid genes such as myeloperoxidase. Similarly, granulocytic markers such as Mac-1 and Gr-1 were not expressed; nor were erythroid and lymphoid surface antigens. Introduction of an inducible C/EBP alpha gene into the line revealed that conditional expression of C/EBP alpha induced the C/EBP family members C/EBP beta and C/EBP epsilon and subsequent granulocyte differentiation. Similar results were obtained when C/EBP alpha(-/-) cells were stimulated with the cytokines interleukin-3 and granulocyte-macrophage colony-stimulating factor, but not with all-trans retinoic acid, supporting a model of at least 2 pathways leading to the differentiation of myeloid progenitors to granulocytes and implicating induction of other C/EBP family members in granulopoiesis.
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Affiliation(s)
- Pu Zhang
- Harvard Institutes of Medicine, Harvard Medical School, Boston, MA 02115, USA
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Abstract
A common myeloid progenitor gives rise to both granulocytes and monocytes. The early stages of granulopoiesis are mediated by the C/EBPalpha, PU.1, RAR, CBF, and c-Myb transcription factors, and the later stages require C/EBPepsilon, PU.1, and CDP. Monocyte development requires PU.1 and interferon consensus sequence binding protein and can be induced by Maf-B, c-Jun, or Egr-1. Cytokine receptor signals modulate transcription factor activities but do not determine cell fates. Several mechanisms orchestrate the myeloid developmental program, including cooperative gene regulation, protein:protein interactions, regulation of factor levels, and induction of cell cycle arrest.
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Affiliation(s)
- Alan D Friedman
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland 21231, USA.
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Abstract
Granulocytes and monocytes develop from a common myeloid progenitor. Early granulopoiesis requires the C/EBPalpha, PU.1, RAR, CBF, and c-Myb transcription factors, and terminal neutrophil differentiation is dependent upon C/EBPepsilon, PU.1, Sp1, CDP, and HoxA10. Monopoiesis can be induced by Maf-B, c-Jun, or Egr-1 and is dependent upon PU.1, Sp1, and ICSBP. Signals eminating from cytokine receptors modulate factor activities but do not determine cell fates. Orchestration of the myeloid developmental program is achieved via cooperative gene regulation, via synergistic and inhibitory protein-protein interactions, via promoter auto-regulation and cross-regulation, via regulation of factor levels, and via induction of cell cycle arrest: For example, c-Myb and C/EBPalpha cooperate to activate the mim-1 and NE promoters, PU.1, C/EBPalpha, and CBF, regulate the NE, MPO, and M-CSF Receptor genes. PU.1:GATA-1 interaction and C/EBP suppression of FOG transcription inhibits erythroid and megakaryocyte gene expression. c-Jun:PU.1, ICSBP:PU.1, and perhaps Maf:Jun complexes induce monocytic genes. PU.1 and C/EBPalpha activate their own promoters, C/EBPalpha rapidly induces PU.1 and C/EBPepsilon RNA expression, and RARalpha activates the C/EBPepsilon promoter. Higher levels of PU.1 are required for monopoiesis than for B-lymphopoiesis, and higher C/EBP levels may favor granulopoiesis over monopoiesis. CBF and c-Myb stimulate proliferation whereas C/EBPalpha induces a G1/S arrest; cell cycle arrest is required for terminal myelopoiesis, perhaps due to expression of p53 or hypo-phosphorylated Rb.
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Affiliation(s)
- Alan D Friedman
- Division of Pediatric Oncology, Johns Hopkins University, Baltimore, Maryland, MD 21231, USA.
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Abstract
Myeloid blood cells comprise an important component of the immune system. Proper control of both lineage- and stage-specific gene expression is required for normal myeloid cell development and function. In recent years, a relatively small number of critical transcriptional regulators have been identified that serve important roles both in myeloid cell development and regulation of lineage-restricted gene expression in mature myeloid cells. This review summarizes our current understanding of the regulation of lineage- and stage-restricted transcription during myeloid cell differentiation, how critical transcriptional regulators control myeloid cell development, and how perturbations in transcription factor function results in the development of leukemia.
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Affiliation(s)
- David G Skalnik
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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Gombart AF, Koeffler HP. Neutrophil specific granule deficiency and mutations in the gene encoding transcription factor C/EBP(epsilon). Curr Opin Hematol 2002; 9:36-42. [PMID: 11753076 DOI: 10.1097/00062752-200201000-00007] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Neutrophil specific granule deficiency (SGD) is a rare congenital disorder. The neutrophils of these patients display atypical bilobed nuclei; lack expression of at least one primary and all secondary and tertiary granule proteins; and possess defects in chemotaxis, disaggregation, receptor upregulation, and bactericidal activity. SGD patients suffer frequent and severe bacterial infections. Although the first of five patients worldwide was reported in the early 1970s, the molecular basis for the defect was discovered only recently. This review presents data implicating the functional loss of the myeloid transcription factor CCAAT/enhancer binding protein (C/EBP(epsilon)) as a causative agent in the development of SGD. The murine model for SGD provides evidence for defects in eosinophil granule gene expression and indicates abnormalities in macrophage maturation and function. Deficiencies in multiple myeloid lineages, in addition to neutrophils, indicate the importance of C/EBP(epsilon) in regulating important innate immune and inflammatory responses critical for host defense.
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Affiliation(s)
- Adrian F Gombart
- Division of Hematology/Oncology, Cedars-Sinai Medical Center, Burns & Allen Research Institute, UCLA School of Medicine, Los Angeles, California 90048, USA.
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