Hes repressors are essential regulators of hematopoietic stem cell development downstream of Notch signaling

PubMed Central

Guiu, Jordi; Shimizu, Ritsuko; D’Altri, Teresa; Fraser, Stuart T.; Hatakeyama, Jun; Bresnick, Emery H.; Kageyama, Ryoichiro; Dzierzak, Elaine; Yamamoto, Masayuki; Espinosa, Lluis

2013-01-01

Previous studies have identified Notch as a key regulator of hematopoietic stem cell (HSC) development, but the underlying downstream mechanisms remain unknown. The Notch target Hes1 is widely expressed in the aortic endothelium and hematopoietic clusters, though Hes1-deficient mice show no overt hematopoietic abnormalities. We now demonstrate that Hes is required for the development of HSC in the mouse embryo, a function previously undetected as the result of functional compensation by de novo expression of Hes5 in the aorta/gonad/mesonephros (AGM) region of Hes1 mutants. Analysis of embryos deficient for Hes1 and Hes5 reveals an intact arterial program with overproduction of nonfunctional hematopoietic precursors and total absence of HSC activity. These alterations were associated with increased expression of the hematopoietic regulators Runx1, c-myb, and the previously identified Notch target Gata2. By analyzing the Gata2 locus, we have identified functional RBPJ-binding sites, which mutation results in loss of Gata2 reporter expression in transgenic embryos, and functional Hes-binding sites, which mutation leads to specific Gata2 up-regulation in the hematopoietic precursors. Together, our findings show that Notch activation in the AGM triggers Gata2 and Hes1 transcription, and next HES-1 protein represses Gata2, creating an incoherent feed-forward loop required to restrict Gata2 expression in the emerging HSCs. PMID:23267012

Teleost growth factor independence (gfi) genes differentially regulate successive waves of hematopoiesis.

PubMed

Cooney, Jeffrey D; Hildick-Smith, Gordon J; Shafizadeh, Ebrahim; McBride, Paul F; Carroll, Kelli J; Anderson, Heidi; Shaw, George C; Tamplin, Owen J; Branco, Diana S; Dalton, Arthur J; Shah, Dhvanit I; Wong, Clara; Gallagher, Patrick G; Zon, Leonard I; North, Trista E; Paw, Barry H

2013-01-15

Growth Factor Independence (Gfi) transcription factors play essential roles in hematopoiesis, differentially activating and repressing transcriptional programs required for hematopoietic stem/progenitor cell (HSPC) development and lineage specification. In mammals, Gfi1a regulates hematopoietic stem cells (HSC), myeloid and lymphoid populations, while its paralog, Gfi1b, regulates HSC, megakaryocyte and erythroid development. In zebrafish, gfi1aa is essential for primitive hematopoiesis; however, little is known about the role of gfi1aa in definitive hematopoiesis or about additional gfi factors in zebrafish. Here, we report the isolation and characterization of an additional hematopoietic gfi factor, gfi1b. We show that gfi1aa and gfi1b are expressed in the primitive and definitive sites of hematopoiesis in zebrafish. Our functional analyses demonstrate that gfi1aa and gfi1b have distinct roles in regulating primitive and definitive hematopoietic progenitors, respectively. Loss of gfi1aa silences markers of early primitive progenitors, scl and gata1. Conversely, loss of gfi1b silences runx-1, c-myb, ikaros and cd41, indicating that gfi1b is required for definitive hematopoiesis. We determine the epistatic relationships between the gfi factors and key hematopoietic transcription factors, demonstrating that gfi1aa and gfi1b join lmo2, scl, runx-1 and c-myb as critical regulators of teleost HSPC. Our studies establish a comparative paradigm for the regulation of hematopoietic lineages by gfi transcription factors. Copyright © 2012 Elsevier Inc. All rights reserved.

Are neural crest stem cells the missing link between hematopoietic and neurogenic niches?

PubMed

Coste, Cécile; Neirinckx, Virginie; Gothot, André; Wislet, Sabine; Rogister, Bernard

2015-01-01

Hematopoietic niches are defined as cellular and molecular microenvironments that regulate hematopoietic stem cell (HSC) function together with stem cell autonomous mechanisms. Many different cell types have been characterized as contributors to the formation of HSC niches, such as osteoblasts, endothelial cells, Schwann cells, and mesenchymal progenitors. These mesenchymal progenitors have themselves been classified as CXC chemokine ligand (CXCL) 12-abundant reticular (CAR) cells, stem cell factor expressing cells, or nestin-positive mesenchymal stem cells (MSCs), which have been recently identified as neural crest-derived cells (NCSCs). Together, these cells are spatially associated with HSCs and believed to provide appropriate microenvironments for HSC self-renewal, differentiation, mobilization and hibernation both by cell-cell contact and soluble factors. Interestingly, it appears that regulatory pathways governing the hematopoietic niche homeostasis are operating in the neurogenic niche as well. Therefore, this review paper aims to compare both the regulation of hematopoietic and neurogenic niches, in order to highlight the role of NCSCs and nervous system components in the development and the regulation of the hematopoietic system.

The human stem cell hierarchy is defined by a functional dependence on Mcl-1 for self-renewal capacity.

PubMed

Campbell, Clinton J V; Lee, Jung Bok; Levadoux-Martin, Marilyne; Wynder, Tracy; Xenocostas, Anargyros; Leber, Brian; Bhatia, Mickie

2010-09-02

The molecular basis for the unique proliferative and self-renewal properties that hierarchically distinguish human stem cells from progenitors and terminally differentiated cells remains largely unknown. We report a role for the Bcl-2 family member myeloid cell leukemia-1 (Mcl-1) as an indispensable regulator of self-renewal in human stem cells and show that a functional dependence on Mcl-1 defines the human stem cell hierarchy. In vivo pharmacologic targeting of the Bcl-2 family members in human hematopoietic stem cells (HSCs) and human leukemic stem cells reduced stem cell regenerative and self-renewal function. Subsequent protein expression studies showed that, among the Bcl-2 family members, only Mcl-1 was up-regulated exclusively in the human HSC fraction on in vivo regeneration of hematopoiesis. Short hairpin RNA-knockdown of Mcl-1 in human cord blood cells did not affect survival in the HSC or hematopoietic progenitor cell fractions in vitro but specifically reduced the in vivo self-renewal function of human HSCs. Moreover, knockdown of Mcl-1 in ontogenetically primitive human pluripotent stem cells resulted in almost complete ablation of stem cell self-renewal function. Our findings show that Mcl-1 is an essential regulator of stem cell self-renewal in humans and therefore represents an axis for therapeutic interventions.

Regulation of Drosophila hematopoietic sites by Activin-β from active sensory neurons

PubMed Central

Makhijani, Kalpana; Alexander, Brandy; Rao, Deepti; Petraki, Sophia; Herboso, Leire; Kukar, Katelyn; Batool, Itrat; Wachner, Stephanie; Gold, Katrina S.; Wong, Corinna; O’Connor, Michael B.; Brückner, Katja

2017-01-01

An outstanding question in animal development, tissue homeostasis and disease is how cell populations adapt to sensory inputs. During Drosophila larval development, hematopoietic sites are in direct contact with sensory neuron clusters of the peripheral nervous system (PNS), and blood cells (hemocytes) require the PNS for their survival and recruitment to these microenvironments, known as Hematopoietic Pockets. Here we report that Activin-β, a TGF-β family ligand, is expressed by sensory neurons of the PNS and regulates the proliferation and adhesion of hemocytes. These hemocyte responses depend on PNS activity, as shown by agonist treatment and transient silencing of sensory neurons. Activin-β has a key role in this regulation, which is apparent from reporter expression and mutant analyses. This mechanism of local sensory neurons controlling blood cell adaptation invites evolutionary parallels with vertebrate hematopoietic progenitors and the independent myeloid system of tissue macrophages, whose regulation by local microenvironments remain undefined. PMID:28748922

Understanding the regulation of vertebrate hematopoiesis and blood disorders: big lessons from a small fish

PubMed Central

Robertson, Anne L.; Avagyan, Serine; Gansner, John M.; Zon, Leonard I.

2017-01-01

Hematopoietic stem cells (HSCs) give rise to all differentiated blood cells. Understanding the mechanisms that regulate self-renewal and lineage specification of HSCs is key for developing treatments for many human diseases. Zebrafish have emerged as an excellent model for studying vertebrate hematopoiesis. This review will highlight the unique strengths of zebrafish and important findings that have emerged from studies of blood development and disorders using this system. We discuss recent advances in our understanding of hematopoiesis, including the origin of HSCs, molecular control of their development, and key signaling pathways involved in their regulation. We highlight significant findings from zebrafish models of blood disorders, and discuss their application for investigating stem cell dysfunction in disease and for developing new therapeutics. PMID:27616157

Genome-wide Analysis of Simultaneous GATA1/2, RUNX1, FLI1, and SCL Binding in Megakaryocytes Identifies Hematopoietic Regulators

PubMed Central

Tijssen, Marloes R.; Cvejic, Ana; Joshi, Anagha; Hannah, Rebecca L.; Ferreira, Rita; Forrai, Ariel; Bellissimo, Dana C.; Oram, S. Helen; Smethurst, Peter A.; Wilson, Nicola K.; Wang, Xiaonan; Ottersbach, Katrin; Stemple, Derek L.; Green, Anthony R.; Ouwehand, Willem H.; Göttgens, Berthold

2011-01-01

Summary Hematopoietic differentiation critically depends on combinations of transcriptional regulators controlling the development of individual lineages. Here, we report the genome-wide binding sites for the five key hematopoietic transcription factors—GATA1, GATA2, RUNX1, FLI1, and TAL1/SCL—in primary human megakaryocytes. Statistical analysis of the 17,263 regions bound by at least one factor demonstrated that simultaneous binding by all five factors was the most enriched pattern and often occurred near known hematopoietic regulators. Eight genes not previously appreciated to function in hematopoiesis that were bound by all five factors were shown to be essential for thrombocyte and/or erythroid development in zebrafish. Moreover, one of these genes encoding the PDZK1IP1 protein shared transcriptional enhancer elements with the blood stem cell regulator TAL1/SCL. Multifactor ChIP-Seq analysis in primary human cells coupled with a high-throughput in vivo perturbation screen therefore offers a powerful strategy to identify essential regulators of complex mammalian differentiation processes. PMID:21571218

Wnt5a Regulates Hematopoietic Stem Cell Proliferation and Repopulation Through the Ryk Receptor

PubMed Central

Povinelli, Benjamin J.; Nemeth, Michael J.

2017-01-01

Proper regulation of the balance between hematopoietic stem cell (HSC) proliferation, self-renewal, and differentiation is necessary to maintain hematopoiesis throughout life. The Wnt family of ligands has been implicated as critical regulators of these processes through a network of signaling pathways. Previously, we have demonstrated that the Wnt5a ligand can induce HSC quiescence through a noncanonical Wnt pathway, resulting in an increased ability to reconstitute hematopoiesis. In this study, we tested the hypothesis that the Ryk protein, a Wnt ligand receptor that can bind the Wnt5a ligand, regulated the response of HSCs to Wnt5a. We observed that inhibiting Ryk blocked the ability of Wnt5a to induce HSC quiescence and enhance short-term and long-term hematopoietic repopulation. We found that Wnt5a suppressed production of reactive oxygen species, a known inducer of HSC proliferation. The ability of Wnt5a to inhibit ROS production was also regulated by Ryk. From these data, we propose that Wnt5a regulates HSC quiescence and hematopoietic repopulation through the Ryk receptor and that this process is mediated by suppression of reactive oxygen species. PMID:23939973

Wnt5a regulates hematopoietic stem cell proliferation and repopulation through the Ryk receptor.

PubMed

Povinelli, Benjamin J; Nemeth, Michael J

2014-01-01

Proper regulation of the balance between hematopoietic stem cell (HSC) proliferation, self-renewal, and differentiation is necessary to maintain hematopoiesis throughout life. The Wnt family of ligands has been implicated as critical regulators of these processes through a network of signaling pathways. Previously, we have demonstrated that the Wnt5a ligand can induce HSC quiescence through a noncanonical Wnt pathway, resulting in an increased ability to reconstitute hematopoiesis. In this study, we tested the hypothesis that the Ryk protein, a Wnt ligand receptor that can bind the Wnt5a ligand, regulated the response of HSCs to Wnt5a. We observed that inhibiting Ryk blocked the ability of Wnt5a to induce HSC quiescence and enhance short-term and long-term hematopoietic repopulation. We found that Wnt5a suppressed production of reactive oxygen species, a known inducer of HSC proliferation. The ability of Wnt5a to inhibit ROS production was also regulated by Ryk. From these data, we propose that Wnt5a regulates HSC quiescence and hematopoietic repopulation through the Ryk receptor and that this process is mediated by suppression of reactive oxygen species. © 2013 AlphaMed Press.

The microRNA-132 and microRNA-212 cluster regulates hematopoietic stem cell maintenance and survival with age by buffering FOXO3 expression

PubMed Central

Mehta, Arnav; Zhao, Jimmy L.; Sinha, Nikita; Marinov, Georgi K.; Mann, Mati; Kowalczyk, Monika S.; Galimidi, Rachel P.; Du, Xiaomi; Erikci, Erdem; Regev, Aviv; Chowdhury, Kamal; Baltimore, David

2015-01-01

Summary MicroRNAs are critical post-transcriptional regulators of hematopoietic cell-fate decisions, though little remains known about their role in aging hematopoietic stem cells (HSCs). We found that the microRNA-212/132 cluster (Mirc19) is enriched in HSCs and is up-regulated during aging. Both over-expression and deletion of microRNAs in this cluster leads to inappropriate hematopoiesis with age. Enforced expression of miR-132 in the bone marrow of mice led to rapid HSC cycling and depletion. A genetic deletion of Mirc19 in mice resulted in HSCs that had altered cycling, function, and survival in response to growth factor starvation. We found that miR-132 exerted its effect on aging HSCs by targeting the transcription factor FOXO3, a known aging associated gene. Our data demonstrates that Mirc19 plays a role in maintaining balanced hematopoietic output by buffering FOXO3 expression. We have thus identified it as a potential target that may play a role in age-related hematopoietic defects. PMID:26084022

Dual role of wingless signaling in stem-like hematopoietic precursor maintenance in Drosophila.

PubMed

Sinenko, Sergey A; Mandal, Lolitika; Martinez-Agosto, Julian A; Banerjee, Utpal

2009-05-01

In Drosophila, blood development occurs in a specialized larval hematopoietic organ, the lymph gland (LG), within which stem-like hemocyte precursors or prohemocytes differentiate to multiple blood cell types. Here we show that components of the Wingless (Wg) signaling pathway are expressed in prohemocytes. Loss- and gain-of-function analysis indicates that canonical Wg signaling is required for maintenance of prohemocytes and negatively regulates their differentiation. Wg signals locally in a short-range fashion within different compartments of the LG. In addition, Wg signaling positively regulates the proliferation and maintenance of cells that function as a hematopoietic niche in Drosophila, the posterior signaling center (PSC), and in the proliferation of crystal cells. Our studies reveal a conserved function of Wg signaling in the maintenance of stem-like blood progenitors and reveal an involvement of this pathway in the regulation of hemocyte differentiation through its action in the hematopoietic niche.

Nuclear adaptor Ldb1 regulates a transcriptional program essential for the maintenance of hematopoietic stem cells

PubMed Central

Li, LiQi; Jothi, Raja; Cui, Kairong; Lee, Jan Y; Cohen, Tsadok; Gorivodsky, Marat; Tzchori, Itai; Zhao, Yangu; Hayes, Sandra M; Bresnick, Emery H; Zhao, Keji; Westphal, Heiner; Love, Paul E

2013-01-01

The nuclear adaptor Ldb1 functions as a core component of multiprotein transcription complexes that regulate differentiation in diverse cell types. In the hematopoietic lineage, Ldb1 forms a complex with the non–DNA-binding adaptor Lmo2 and the transcription factors E2A, Scl and GATA-1 (or GATA-2). Here we demonstrate a critical and continuous requirement for Ldb1 in the maintenance of both fetal and adult mouse hematopoietic stem cells (HSCs). Deletion of Ldb1 in hematopoietic progenitors resulted in the downregulation of many transcripts required for HSC maintenance. Genome-wide profiling by chromatin immunoprecipitation followed by sequencing (ChIP-Seq) identified Ldb1 complex–binding sites at highly conserved regions in the promoters of genes involved in HSC maintenance. Our results identify a central role for Ldb1 in regulating the transcriptional program responsible for the maintenance of HSCs. PMID:21186366

Nuclear adaptor Ldb1 regulates a transcriptional program essential for the maintenance of hematopoietic stem cells.

PubMed

Li, LiQi; Jothi, Raja; Cui, Kairong; Lee, Jan Y; Cohen, Tsadok; Gorivodsky, Marat; Tzchori, Itai; Zhao, Yangu; Hayes, Sandra M; Bresnick, Emery H; Zhao, Keji; Westphal, Heiner; Love, Paul E

2011-02-01

The nuclear adaptor Ldb1 functions as a core component of multiprotein transcription complexes that regulate differentiation in diverse cell types. In the hematopoietic lineage, Ldb1 forms a complex with the non-DNA-binding adaptor Lmo2 and the transcription factors E2A, Scl and GATA-1 (or GATA-2). Here we demonstrate a critical and continuous requirement for Ldb1 in the maintenance of both fetal and adult mouse hematopoietic stem cells (HSCs). Deletion of Ldb1 in hematopoietic progenitors resulted in the downregulation of many transcripts required for HSC maintenance. Genome-wide profiling by chromatin immunoprecipitation followed by sequencing (ChIP-Seq) identified Ldb1 complex-binding sites at highly conserved regions in the promoters of genes involved in HSC maintenance. Our results identify a central role for Ldb1 in regulating the transcriptional program responsible for the maintenance of HSCs.

Rap G protein signal in normal and disordered lymphohematopoiesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minato, Nagahiro, E-mail: minato@imm.med.kyoto-u.ac.jp

2013-09-10

Rap proteins (Rap1, Rap2a, b, c) are small molecular weight GTPases of the Ras family. Rap G proteins mediate diverse cellular events such as cell adhesion, proliferation, and gene activation through various signaling pathways. Activation of Rap signal is regulated tightly by several specific regulatory proteins including guanine nucleotide exchange factors and GTPase-activating proteins. Beyond cell biological studies, increasing attempts have been made in the past decade to define the roles of Rap signal in specific functions of normal tissue systems as well as in cancer. In the immune and hematopoietic systems, Rap signal plays crucial roles in the developmentmore » and function of essentially all lineages of lymphocytes and hematopoietic cells, and importantly, deregulated Rap signal may lead to unique pathological conditions depending on the affected cell types, including various types of leukemia and autoimmunity. The phenotypical studies have unveiled novel, even unexpected functional aspects of Rap signal in cells from a variety of tissues, providing potentially important clues for controlling human diseases, including malignancy.« less

MicroRNA profiling of the murine hematopoietic system

PubMed Central

Monticelli, Silvia; Ansel, K Mark; Xiao, Changchun; Socci, Nicholas D; Krichevsky, Anna M; Thai, To-Ha; Rajewsky, Nikolaus; Marks, Debora S; Sander, Chris; Rajewsky, Klaus; Rao, Anjana; Kosik, Kenneth S

2005-01-01

Background MicroRNAs (miRNAs) are a class of recently discovered noncoding RNA genes that post-transcriptionally regulate gene expression. It is becoming clear that miRNAs play an important role in the regulation of gene expression during development. However, in mammals, expression data are principally based on whole tissue analysis and are still very incomplete. Results We used oligonucleotide arrays to analyze miRNA expression in the murine hematopoietic system. Complementary oligonucleotides capable of hybridizing to 181 miRNAs were immobilized on a membrane and probed with radiolabeled RNA derived from low molecular weight fractions of total RNA from several different hematopoietic and neuronal cells. This method allowed us to analyze cell type-specific patterns of miRNA expression and to identify miRNAs that might be important for cell lineage specification and/or cell effector functions. Conclusion This is the first report of systematic miRNA gene profiling in cells of the hematopoietic system. As expected, miRNA expression patterns were very different between hematopoietic and non-hematopoietic cells, with further subtle differences observed within the hematopoietic group. Interestingly, the most pronounced similarities were observed among fully differentiated effector cells (Th1 and Th2 lymphocytes and mast cells) and precursors at comparable stages of differentiation (double negative thymocytes and pro-B cells), suggesting that in addition to regulating the process of commitment to particular cellular lineages, miRNAs might have an important general role in the mechanism of cell differentiation and maintenance of cell identity. PMID:16086853

Estrogen signaling selectively induces apoptosis of hematopoietic progenitors and myeloid neoplasms without harming steady-state hematopoiesis.

PubMed

Sánchez-Aguilera, Abel; Arranz, Lorena; Martín-Pérez, Daniel; García-García, Andrés; Stavropoulou, Vaia; Kubovcakova, Lucia; Isern, Joan; Martín-Salamanca, Sandra; Langa, Xavier; Skoda, Radek C; Schwaller, Jürg; Méndez-Ferrer, Simón

2014-12-04

Estrogens are potent regulators of mature hematopoietic cells; however, their effects on primitive and malignant hematopoietic cells remain unclear. Using genetic and pharmacological approaches, we observed differential expression and function of estrogen receptors (ERs) in hematopoietic stem cell (HSC) and progenitor subsets. ERα activation with the selective ER modulator (SERM) tamoxifen induced apoptosis in short-term HSCs and multipotent progenitors. In contrast, tamoxifen induced proliferation of quiescent long-term HSCs, altered the expression of self-renewal genes, and compromised hematopoietic reconstitution after myelotoxic stress, which was reversible. In mice, tamoxifen treatment blocked development of JAK2(V617F)-induced myeloproliferative neoplasm in vivo, induced apoptosis of human JAK2(V617F+) HSPCs in a xenograft model, and sensitized MLL-AF9(+) leukemias to chemotherapy. Apoptosis was selectively observed in mutant cells, and tamoxifen treatment only had a minor impact on steady-state hematopoiesis in disease-free animals. Together, these results uncover specific regulation of hematopoietic progenitors by estrogens and potential antileukemic properties of SERMs. Copyright © 2014 Elsevier Inc. All rights reserved.

The histone H2A deubiquitinase Usp16 regulates hematopoiesis and hematopoietic stem cell function.

PubMed

Gu, Yue; Jones, Amanda E; Yang, Wei; Liu, Shanrun; Dai, Qian; Liu, Yudong; Swindle, C Scott; Zhou, Dewang; Zhang, Zhuo; Ryan, Thomas M; Townes, Tim M; Klug, Christopher A; Chen, Dongquan; Wang, Hengbin

2016-01-05

Epigenetic mechanisms play important regulatory roles in hematopoiesis and hematopoietic stem cell (HSC) function. Subunits of polycomb repressive complex 1 (PRC1), the major histone H2A ubiquitin ligase, are critical for both normal and pathological hematopoiesis; however, it is unclear which of the several counteracting H2A deubiquitinases functions along with PRC1 to control H2A ubiquitination (ubH2A) level and regulates hematopoiesis in vivo. Here we investigated the function of Usp16 in mouse hematopoiesis. Conditional deletion of Usp16 in bone marrow resulted in a significant increase of global ubH2A level and lethality. Usp16 deletion did not change HSC number but was associated with a dramatic reduction of mature and progenitor cell populations, revealing a role in governing HSC lineage commitment. ChIP- and RNA-sequencing studies in HSC and progenitor cells revealed that Usp16 bound to many important hematopoietic regulators and that Usp16 deletion altered the expression of genes in transcription/chromosome organization, immune response, hematopoietic/lymphoid organ development, and myeloid/leukocyte differentiation. The altered gene expression was partly rescued by knockdown of PRC1 subunits, suggesting that Usp16 and PRC1 counterbalance each other to regulate cellular ubH2A level and gene expression in the hematopoietic system. We further discovered that knocking down Cdkn1a (p21cip1), a Usp16 target and regulated gene, rescued the altered cell cycle profile and differentiation defect of Usp16-deleted HSCs. Collectively, these studies identified Usp16 as one of the histone H2A deubiquitinases, which coordinates with the H2A ubiquitin ligase PRC1 to regulate hematopoiesis, and revealed cell cycle regulation by Usp16 as key for HSC differentiation.

Stable multilineage xenogeneic replacement of definitive hematopoiesis in adult zebrafish.

PubMed

Hess, Isabell; Boehm, Thomas

2016-01-18

Bony fishes are the most numerous and phenotypically diverse group of vertebrates inhabiting our planet, making them an ideal target for identifying general principles of tissue development and function. However, lack of suitable experimental platforms prevents the exploitation of this rich source of natural phenotypic variation. Here, we use a zebrafish strain lacking definitive hematopoiesis for interspecific analysis of hematopoietic cell development. Without conditioning prior to transplantation, hematopoietic progenitor cells from goldfish stably engraft in adult zebrafish homozygous for the c-myb(I181N) mutation. However, in competitive repopulation experiments, zebrafish hematopoietic cells exhibit an advantage over their goldfish counterparts, possibly owing to subtle species-specific functional differences in hematopoietic microenvironments resulting from over 100 million years of independent evolution. Thus, our unique animal model provides an unprecedented opportunity to genetically and functionally disentangle universal and species-specific contributions of the microenvironment to hematopoietic progenitor cell maintenance and development.

Osteomacs interact with megakaryocytes and osteoblasts to regulate murine hematopoietic stem cell function.

PubMed

Mohamad, Safa F; Xu, Linlin; Ghosh, Joydeep; Childress, Paul J; Abeysekera, Irushi; Himes, Evan R; Wu, Hao; Alvarez, Marta B; Davis, Korbin M; Aguilar-Perez, Alexandra; Hong, Jung Min; Bruzzaniti, Angela; Kacena, Melissa A; Srour, Edward F

2017-12-12

Networking between hematopoietic stem cells (HSCs) and cells of the hematopoietic niche is critical for stem cell function and maintenance of the stem cell pool. We characterized calvariae-resident osteomacs (OMs) and their interaction with megakaryocytes to sustain HSC function and identified distinguishing properties between OMs and bone marrow (BM)-derived macrophages. OMs, identified as CD45 + F4/80 + cells, were easily detectable (3%-5%) in neonatal calvarial cells. Coculture of neonatal calvarial cells with megakaryocytes for 7 days increased OM three- to sixfold, demonstrating that megakaryocytes regulate OM proliferation. OMs were required for the hematopoiesis-enhancing activity of osteoblasts, and this activity was augmented by megakaryocytes. Serial transplantation demonstrated that HSC repopulating potential was best maintained by in vitro cultures containing osteoblasts, OMs, and megakaryocytes. With or without megakaryocytes, BM-derived macrophages were unable to functionally substitute for neonatal calvarial cell-associated OMs. In addition, OMs differentiated into multinucleated, tartrate resistant acid phosphatase-positive osteoclasts capable of bone resorption. Nine-color flow cytometric analysis revealed that although BM-derived macrophages and OMs share many cell surface phenotypic similarities (CD45, F4/80, CD68, CD11b, Mac2, and Gr-1), only a subgroup of OMs coexpressed M-CSFR and CD166, thus providing a unique profile for OMs. CD169 was expressed by both OMs and BM-derived macrophages and therefore was not a distinguishing marker between these 2 cell types. These results demonstrate that OMs support HSC function and illustrate that megakaryocytes significantly augment the synergistic activity of osteoblasts and OMs. Furthermore, this report establishes for the first time that the crosstalk between OMs, osteoblasts, and megakaryocytes is a novel network supporting HSC function.

Memory T and memory B cells share a transcriptional program of self-renewal with long-term hematopoietic stem cells

PubMed Central

Luckey, Chance John; Bhattacharya, Deepta; Goldrath, Ananda W.; Weissman, Irving L.; Benoist, Christophe; Mathis, Diane

2006-01-01

The only cells of the hematopoietic system that undergo self-renewal for the lifetime of the organism are long-term hematopoietic stem cells and memory T and B cells. To determine whether there is a shared transcriptional program among these self-renewing populations, we first compared the gene-expression profiles of naïve, effector and memory CD8+ T cells with those of long-term hematopoietic stem cells, short-term hematopoietic stem cells, and lineage-committed progenitors. Transcripts augmented in memory CD8+ T cells relative to naïve and effector T cells were selectively enriched in long-term hematopoietic stem cells and were progressively lost in their short-term and lineage-committed counterparts. Furthermore, transcripts selectively decreased in memory CD8+ T cells were selectively down-regulated in long-term hematopoietic stem cells and progressively increased with differentiation. To confirm that this pattern was a general property of immunologic memory, we turned to independently generated gene expression profiles of memory, naïve, germinal center, and plasma B cells. Once again, memory-enriched and -depleted transcripts were also appropriately augmented and diminished in long-term hematopoietic stem cells, and their expression correlated with progressive loss of self-renewal function. Thus, there appears to be a common signature of both up- and down-regulated transcripts shared between memory T cells, memory B cells, and long-term hematopoietic stem cells. This signature was not consistently enriched in neural or embryonic stem cell populations and, therefore, appears to be restricted to the hematopoeitic system. These observations provide evidence that the shared phenotype of self-renewal in the hematopoietic system is linked at the molecular level. PMID:16492737

Bone marrow adipocytes as negative regulators of the hematopoietic microenvironment

PubMed Central

Naveiras, Olaia; Nardi, Valentina; Wenzel, Pamela L.; Fahey, Frederic; Daley, George Q.

2009-01-01

Osteoblasts and endothelium constitute functional niches that support hematopoietic stem cells (HSC) in mammalian bone marrow (BM) 1,2,3 . Adult BM also contains adipocytes, whose numbers correlate inversely with the hematopoietic activity of the marrow. Fatty infiltration of hematopoietic red marrow follows irradiation or chemotherapy and is a diagnostic feature in biopsies from patients with marrow aplasia 4. To explore whether adipocytes influence hematopoiesis or simply fill marrow space, we compared the hematopoietic activity of distinct regions of the mouse skeleton that differ in adiposity. By flow cytometry, colony forming activity, and competitive repopulation assay, HSCs and short-term progenitors are reduced in frequency in the adipocyte-rich vertebrae of the mouse tail relative to the adipocyte-free vertebrae of the thorax. In lipoatrophic A-ZIP/F1 “fatless” mice, which are genetically incapable of forming adipocytes8, and in mice treated with the PPARγ inhibitor Bisphenol-A-DiGlycidyl-Ether (BADGE), which inhibits adipogenesis9, post-irradiation marrow engraftment is accelerated relative to wild type or untreated mice. These data implicate adipocytes as predominantly negative regulators of the bone marrow microenvironment, and suggest that antagonizingmarrow adipogenesis may enhance hematopoietic recovery in clinical bone marrow transplantation. PMID:19516257

HoxBlinc RNA Recruits Set1/MLL Complexes to Activate Hox Gene Expression Patterns and Mesoderm Lineage Development.

PubMed

Deng, Changwang; Li, Ying; Zhou, Lei; Cho, Joonseok; Patel, Bhavita; Terada, Naohiro; Li, Yangqiu; Bungert, Jörg; Qiu, Yi; Huang, Suming

2016-01-05

Trithorax proteins and long-intergenic noncoding RNAs are critical regulators of embryonic stem cell pluripotency; however, how they cooperatively regulate germ layer mesoderm specification remains elusive. We report here that HoxBlinc RNA first specifies Flk1(+) mesoderm and then promotes hematopoietic differentiation through regulation of hoxb pathways. HoxBlinc binds to the hoxb genes, recruits Setd1a/MLL1 complexes, and mediates long-range chromatin interactions to activate transcription of the hoxb genes. Depletion of HoxBlinc by shRNA-mediated knockdown or CRISPR-Cas9-mediated genetic deletion inhibits expression of hoxb genes and other factors regulating cardiac/hematopoietic differentiation. Reduced hoxb expression is accompanied by decreased recruitment of Set1/MLL1 and H3K4me3 modification, as well as by reduced chromatin loop formation. Re-expression of hoxb2-b4 genes in HoxBlinc-depleted embryoid bodies rescues Flk1(+) precursors that undergo hematopoietic differentiation. Thus, HoxBlinc plays an important role in controlling hoxb transcription networks that mediate specification of mesoderm-derived Flk1(+) precursors and differentiation of Flk1(+) cells into hematopoietic lineages. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

HoxBlinc RNA recruits Set1/MLL complexes to activate Hox gene expression patterns and mesoderm lineage development

PubMed Central

Deng, Changwang; Li, Ying; Zhou, Lei; Cho, Joonseok; Patel, Bhavita; Terada, Nao; Li, Yangqiu; Bungert, Jörg; Qiu, Yi; Huang, Suming

2015-01-01

Summary Trithorax proteins and long-intergenic noncoding RNAs are critical regulators of embryonic stem cell pluripotency; however, how they cooperatively regulate germ layer mesoderm specification remains elusive. We report here that HoxBlinc RNA first specifies Flk1+ mesoderm and then promotes hematopoietic differentiation through regulating hoxb gene pathways. HoxBlinc binds to the hoxb genes, recruits Setd1a/MLL1 complexes, and mediates long-range chromatin interactions to activate transcription of the hoxb genes. Depletion of HoxBlinc by shRNA-mediated KD or CRISPR-Cas9-mediated genetic deletion inhibits expression of hoxb genes and other factors regulating cardiac/hematopoietic differentiation. Reduced hoxb gene expression is accompanied by decreased recruitment of Set1/MLL1 and H3K4me3 modification, as well as by reduced chromatin loop formation. Re-expression of hoxb2-b4 genes in HoxBlinc-depleted embryoid bodies rescues Flk1+ precursors that undergo hematopoietic differentiation. Thus, HoxBlinc plays an important role in controlling hoxb transcription networks that mediate specification of mesoderm-derived Flk1+ precursors and differentiation of Flk1+ cells into hematopoietic lineages. PMID:26725110

Unique BK virus non-coding control region (NCCR) variants in hematopoietic stem cell transplant recipients with and without hemorrhagic cystitis.

PubMed

Carr, Michael J; McCormack, Grace P; Mutton, Ken J; Crowley, Brendan

2006-04-01

Hematopoietic stem cell transplant recipients frequently develop BK virus (BKV)-associated hemorrhagic cystitis, which coincides with BK viruria. However, the precise role of BKV in the etiology of hemorrhagic cystitis in hematopoietic stem cell transplant recipients remains unclear, since approximately 50% of all such adult transplant recipients excrete BKV, yet do not develop this clinical condition. In the present study, BKV were analyzed to determine if mutations in the non-coding control region (NCCR), and specific BKV sub-types defined by sequence analysis of major capsid protein VP1, were associated with development of hemorrhagic cystitis in hematopoietic stem cell transplant recipients. The regions encoding VP1 and NCCRs of BKV in urine samples collected from 15 hematopoietic stem cell transplant recipients with hemorrhagic cystitis and 20 without this illness were amplified and sequenced. Sequence variations in the NCCRs of BKV were identified in urine samples from those with and without hemorrhagic cystitis. Furthermore, five unique sequence variations within transcription factor binding sites in the canonical NCCR, O-P-Q-R-S, were identified, representing new BKV variants from a population of cloned quasi-species obtained from patients with and without hemorrhagic cystitis. Thirty-five BKV VP1 sequences were analyzed by phylogenetic analysis but no specific BKV sub-type was associated with hemorrhagic cystitis. Five previously unrecognized naturally occurring variants of the BKV are described which involve amplifications, deletions, and rearrangements of the archetypal BKV NCCRs in individuals with and without hemorrhagic cystitis. Architectural rearrangements in the NCCRs of BKV did not appear to be a prerequisite for development of hemorrhagic cystitis in hematopoietic stem cell transplant recipients. Copyright 2006 Wiley-Liss, Inc.

The RUNX1 +24 enhancer and P1 promoter identify a unique subpopulation of hematopoietic progenitor cells derived from human pluripotent stem cells

PubMed Central

Ferrell, Patrick I; Xi, Jiafei; Ma, Chao; Adlakha, Mitali; Kaufman, Dan S.

2016-01-01

Derivation of hematopoietic stem cells from human pluripotent stem cells remains a key goal for the fields of developmental biology and regenerative medicine. Here, we use a novel genetic reporter system to prospectively identify and isolate early hematopoietic cells derived from human embryonic stem cells (hESCs) and human induced pluripotent cells (iPSCs). Cloning the human RUNX1c P1 promoter and +24 enhancer to drive expression of tdTomato (tdTom) in hESCs and iPSCs, we demonstrate that tdTom expression faithfully enriches for RUNX1c-expressing hematopoietic progenitor cells. Time-lapse microscopy demonstrated the tdTom+ hematopoietic cells to emerge from adherent cells. Furthermore, inhibition of primitive hematopoiesis by blocking Activin/Nodal signaling promoted the expansion and/or survival of tdTom+ population. Notably, RUNX1c/tdTom+ cells represent only a limited subpopuation of CD34+CD45+ and CD34+CD43+ cells with a unique genetic signature. Using gene array analysis, we find significantly lower expression of Let-7 and mir181a microRNAs in the RUNX1c/tdTom+ cell population. These phenotypic and genetic analyses comparing the RUNX1c/tdTom+ population to CD34+CD45+ umbilical cord blood and fetal liver demonstrate several key differences that likely impact the development of HSCs capable of long-term multilineage engraftment from hESCs and iPSCs. PMID:25546363

Fanconi Anemia: A DNA repair disorder characterized by accelerated decline of the hematopoietic stem cell compartment and other features of aging.

PubMed

Brosh, Robert M; Bellani, Marina; Liu, Yie; Seidman, Michael M

2017-01-01

Fanconi Anemia (FA) is a rare autosomal genetic disorder characterized by progressive bone marrow failure (BMF), endocrine dysfunction, cancer, and other clinical features commonly associated with normal aging. The anemia stems directly from an accelerated decline of the hematopoietic stem cell compartment. Although FA is a complex heterogeneous disease linked to mutations in 19 currently identified genes, there has been much progress in understanding the molecular pathology involved. FA is broadly considered a DNA repair disorder and the FA gene products, together with other DNA repair factors, have been implicated in interstrand cross-link (ICL) repair. However, in addition to the defective DNA damage response, altered epigenetic regulation, and telomere defects, FA is also marked by elevated levels of inflammatory mediators in circulation, a hallmark of faster decline in not only other hereditary aging disorders but also normal aging. In this review, we offer a perspective of FA as a monogenic accelerated aging disorder, citing the latest evidence for its multi-factorial deficiencies underlying its unique clinical and cellular features. Published by Elsevier B.V.

Downstream targets of HOXB4 in a cell line model of primitive hematopoietic progenitor cells.

PubMed

Lee, Han M; Zhang, Hui; Schulz, Vincent; Tuck, David P; Forget, Bernard G

2010-08-05

Enforced expression of the homeobox transcription factor HOXB4 has been shown to enhance hematopoietic stem cell self-renewal and expansion ex vivo and in vivo. To investigate the downstream targets of HOXB4 in hematopoietic progenitor cells, HOXB4 was constitutively overexpressed in the primitive hematopoietic progenitor cell line EML. Two genome-wide analytical techniques were used: RNA expression profiling using microarrays and chromatin immunoprecipitation (ChIP)-chip. RNA expression profiling revealed that 465 gene transcripts were differentially expressed in KLS (c-Kit(+), Lin(-), Sca-1(+))-EML cells that overexpressed HOXB4 (KLS-EML-HOXB4) compared with control KLS-EML cells that were transduced with vector alone. In particular, erythroid-specific gene transcripts were observed to be highly down-regulated in KLS-EML-HOXB4 cells. ChIP-chip analysis revealed that the promoter region for 1910 genes, such as CD34, Sox4, and B220, were occupied by HOXB4 in KLS-EML-HOXB4 cells. Side-by-side comparison of the ChIP-chip and RNA expression profiling datasets provided correlative information and identified Gp49a and Laptm4b as candidate "stemness-related" genes. Both genes were highly ranked in both dataset lists and have been previously shown to be preferentially expressed in hematopoietic stem cells and down-regulated in mature hematopoietic cells, thus making them attractive candidates for future functional studies in hematopoietic cells.

A role for intracellular and extracellular DEK in regulating hematopoiesis.

PubMed

Capitano, Maegan L; Broxmeyer, Hal E

2017-07-01

Hematopoietic stem/progenitor cell fate decision during hematopoiesis is regulated by intracellular and extracellular signals such as transcription factors, growth factors, and cell-to-cell interactions. In this review, we explore the function of DEK, a nuclear phosphoprotein, on gene regulation. We also examine how DEK is secreted and internalized by cells, and discuss how both endogenous and extracellular DEK regulates hematopoiesis. Finally, we explore what currently is known about the regulation of DEK during inflammation. DEK negatively regulates the proliferation of early myeloid progenitor cells but has a positive effect on the differentiation of mature myeloid cells. Inflammation regulates intracellular DEK concentrations with inflammatory stimuli enhancing DEK expression. Inflammation-induced nuclear factor-kappa B activation is regulated by DEK, resulting in changes in the production of other inflammatory molecules such as IL-8. Inflammatory stimuli in turn regulates DEK secretion by cells of hematopoietic origin. However, how inflammation-induced expression and secretion of DEK regulates hematopoiesis remains unknown. Understanding how DEK regulates hematopoiesis under both homeostatic and inflammatory conditions may lead to a better understanding of the biology of HSCs and HPCs. Furthering our knowledge of the regulation of hematopoiesis will ultimately lead to new therapeutics that may increase the efficacy of hematopoietic stem cell transplantation.

Flow-induced protein kinase A–CREB pathway acts via BMP signaling to promote HSC emergence

PubMed Central

Kim, Peter Geon; Nakano, Haruko; Das, Partha P.; Chen, Michael J.; Rowe, R. Grant; Chou, Stephanie S.; Ross, Samantha J.; Sakamoto, Kathleen M.; Zon, Leonard I.; Schlaeger, Thorsten M.; Orkin, Stuart H.; Nakano, Atsushi

2015-01-01

Fluid shear stress promotes the emergence of hematopoietic stem cells (HSCs) in the aorta–gonad–mesonephros (AGM) of the developing mouse embryo. We determined that the AGM is enriched for expression of targets of protein kinase A (PKA)–cAMP response element-binding protein (CREB), a pathway activated by fluid shear stress. By analyzing CREB genomic occupancy from chromatin-immunoprecipitation sequencing (ChIP-seq) data, we identified the bone morphogenetic protein (BMP) pathway as a potential regulator of CREB. By chemical modulation of the PKA–CREB and BMP pathways in isolated AGM VE-cadherin+ cells from mid-gestation embryos, we demonstrate that PKA–CREB regulates hematopoietic engraftment and clonogenicity of hematopoietic progenitors, and is dependent on secreted BMP ligands through the type I BMP receptor. Finally, we observed blunting of this signaling axis using Ncx1-null embryos, which lack a heartbeat and intravascular flow. Collectively, we have identified a novel PKA–CREB–BMP signaling pathway downstream of shear stress that regulates HSC emergence in the AGM via the endothelial-to-hematopoietic transition. PMID:25870201

Deletion of the Imprinted Gene Grb10 Promotes Hematopoietic Stem Cell Self-Renewal and Regeneration.

PubMed

Yan, Xiao; Himburg, Heather A; Pohl, Katherine; Quarmyne, Mamle; Tran, Evelyn; Zhang, Yurun; Fang, Tiancheng; Kan, Jenny; Chao, Nelson J; Zhao, Liman; Doan, Phuong L; Chute, John P

2016-11-01

Imprinted genes are differentially expressed by adult stem cells, but their functions in regulating adult stem cell fate are incompletely understood. Here we show that growth factor receptor-bound protein 10 (Grb10), an imprinted gene, regulates hematopoietic stem cell (HSC) self-renewal and regeneration. Deletion of the maternal allele of Grb10 in mice (Grb10 m/+ mice) substantially increased HSC long-term repopulating capacity, as compared to that of Grb10 +/+ mice. After total body irradiation (TBI), Grb10 m/+ mice demonstrated accelerated HSC regeneration and hematopoietic reconstitution, as compared to Grb10 +/+ mice. Grb10-deficient HSCs displayed increased proliferation after competitive transplantation or TBI, commensurate with upregulation of CDK4 and Cyclin E. Furthermore, the enhanced HSC regeneration observed in Grb10-deficient mice was dependent on activation of the Akt/mTORC1 pathway. This study reveals a function for the imprinted gene Grb10 in regulating HSC self-renewal and regeneration and suggests that the inhibition of Grb10 can promote hematopoietic regeneration in vivo. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Menin regulates the function of hematopoietic stem cells and lymphoid progenitors

PubMed Central

Chen, Ya-Xiong; Friedman, Ann; Yang, Yuqing; Tubbs, Anthony T.; Shestova, Olga; Pear, Warren S.

2009-01-01

Men1 is a tumor suppressor gene mutated in endocrine neoplasms. Besides its endocrine role, the Men1 gene product menin interacts with the mixed lineage leukemia (MLL) protein, a histone H3 lysine 4 methyltransferase. Although menin and MLL fusion proteins cooperate to activate Homeobox (Hox) gene expression during transformation, little is known about the normal hematopoietic functions of menin. Here, we studied hematopoiesis after Men1 ablation. Menin loss modestly impaired blood neutrophil, lymphocyte, and platelet counts. Without hematopoietic stress, multilineage and myelo-erythroid bone marrow progenitor numbers were preserved, while B lymphoid progenitors were decreased. In contrast, competitive transplantation revealed a marked functional defect of long-term hematopoietic stem cells (HSC) in the absence of menin, despite normal initial homing of progenitors to the bone marrow. HoxA9 gene expression was only modestly decreased in menin-deficient HSCs. These observations reveal a novel and essential role for menin in HSC homeostasis that was most apparent during situations of hematopoietic recovery, suggesting that menin regulates molecular pathways that are essential during the adaptive HSC response to stress. PMID:19228930

CXCR1 remodels the vascular niche to promote hematopoietic stem and progenitor cell engraftment

PubMed Central

Blaser, Bradley W.; Moore, Jessica L.; Hagedorn, Elliott J.; Li, Brian; Riquelme, Raquel; Yang, Song; Zhou, Yi; Tamplin, Owen J.; Binder, Vera

2017-01-01

The microenvironment is an important regulator of hematopoietic stem and progenitor cell (HSPC) biology. Recent advances marking fluorescent HSPCs have allowed exquisite visualization of HSPCs in the caudal hematopoietic tissue (CHT) of the developing zebrafish. Here, we show that the chemokine cxcl8 and its receptor, cxcr1, are expressed by zebrafish endothelial cells, and we identify cxcl8/cxcr1 signaling as a positive regulator of HSPC colonization. Single-cell tracking experiments demonstrated that this is a result of increases in HSPC–endothelial cell “cuddling,” HSPC residency time within the CHT, and HSPC mitotic rate. Enhanced cxcl8/cxcr1 signaling was associated with an increase in the volume of the CHT and induction of cxcl12a expression. Finally, using parabiotic zebrafish, we show that cxcr1 acts HSPC nonautonomously to improve the efficiency of donor HSPC engraftment. This work identifies a mechanism by which the hematopoietic niche remodels to promote HSPC engraftment and suggests that cxcl8/cxcr1 signaling is a potential therapeutic target in patients undergoing hematopoietic stem cell transplantation. PMID:28351983

Immune-related zinc finger gene ZFAT is an essential transcriptional regulator for hematopoietic differentiation in blood islands

PubMed Central

Tsunoda, Toshiyuki; Takashima, Yasuo; Tanaka, Yoko; Fujimoto, Takahiro; Doi, Keiko; Hirose, Yumiko; Koyanagi, Midori; Yoshida, Yasuhiro; Okamura, Tadashi; Kuroki, Masahide; Sasazuki, Takehiko; Shirasawa, Senji

2010-01-01

TAL1 plays pivotal roles in vascular and hematopoietic developments through the complex with LMO2 and GATA1. Hemangioblasts, which have a differentiation potential for both endothelial and hematopoietic lineages, arise in the primitive streak and migrate into the yolk sac to form blood islands, where primitive hematopoiesis occurs. ZFAT (a zinc-finger gene in autoimmune thyroid disease susceptibility region / an immune-related transcriptional regulator containing 18 C2H2-type zinc-finger domains and one AT-hook) was originally identified as an immune-related transcriptional regulator containing 18 C2H2-type zinc-finger domains and one AT-hook, and is highly conserved among species. ZFAT is thought to be a critical transcription factor involved in immune-regulation and apoptosis; however, developmental roles for ZFAT remain unknown. Here we show that Zfat-deficient (Zfat−/−) mice are embryonic-lethal, with impaired differentiation of hematopoietic progenitor cells in blood islands, where ZFAT is exactly expressed. Expression levels of Tal1, Lmo2, and Gata1 in Zfat−/− yolk sacs are much reduced compared with those of wild-type mice, and ChIP-PCR analysis revealed that ZFAT binds promoter regions for these genes in vivo. Furthermore, profound reduction in TAL1, LMO2, and GATA1 protein expressions are observed in Zfat−/− blood islands. Taken together, these results suggest that ZFAT is indispensable for mouse embryonic development and functions as a critical transcription factor for primitive hematopoiesis through direct-regulation of Tal1, Lmo2, and Gata1. Elucidation of ZFAT functions in hematopoiesis might lead to a better understanding of transcriptional networks in differentiation and cellular programs of hematopoietic lineage and provide useful information for applied medicine in stem cell therapy. PMID:20660741

Knockdown of Fanconi anemia genes in human embryonic stem cells reveals early developmental defects in the hematopoietic lineage.

PubMed

Tulpule, Asmin; Lensch, M William; Miller, Justine D; Austin, Karyn; D'Andrea, Alan; Schlaeger, Thorsten M; Shimamura, Akiko; Daley, George Q

2010-04-29

Fanconi anemia (FA) is a genetically heterogeneous, autosomal recessive disorder characterized by pediatric bone marrow failure and congenital anomalies. The effect of FA gene deficiency on hematopoietic development in utero remains poorly described as mouse models of FA do not develop hematopoietic failure and such studies cannot be performed on patients. We have created a human-specific in vitro system to study early hematopoietic development in FA using a lentiviral RNA interference (RNAi) strategy in human embryonic stem cells (hESCs). We show that knockdown of FANCA and FANCD2 in hESCs leads to a reduction in hematopoietic fates and progenitor numbers that can be rescued by FA gene complementation. Our data indicate that hematopoiesis is impaired in FA from the earliest stages of development, suggesting that deficiencies in embryonic hematopoiesis may underlie the progression to bone marrow failure in FA. This work illustrates how hESCs can provide unique insights into human development and further our understanding of genetic disease.

Isolation, Characterization, and Transplantation of Bone Marrow-Derived Cell Components with Hematopoietic Stem Cell Niche Properties

PubMed Central

Ahmadbeigi, Naser; Vasei, Mohammad; Gheisari, Yousof; Mortazavi, Yousef; Azadmanesh, Kayhan; Omidkhoda, Azadeh; Janzamin, Ehsan; Nardi, Nance Beyer

2013-01-01

Although the unique role of hematopoietic stem cell (HSC) niche in hematopoiesis has long been recognized, unsuccessful isolation of intact niche units limited their in vitro study, manipulation, and therapeutic application. Here, we isolated cell complexes based on size fractionation from mouse bone marrow (BM), characterized the derived cells, and transplanted them to irradiated mice. These cell complexes were the origin of both BM mesenchymal stem cells and various hematopoietic lineages when kept in appropriate culture conditions. They also had the potential of recruiting circulating HSC. Intraperitoneal transplantation of these structures into irradiated mice not only showed long-lasting hematopoietic multilineage reconstitution, but also could recover the stromal cells of BM. In conclusion, this study for the first time provides evidences on the feasibility and efficacy of transplantation of HSC in association with their native specialized microenvironment. As the molecular cross-talk between HSC and niche is crucial for their proper function, the proposed method could be considered as a novel hematopoietic transplantation strategy. PMID:23879861

Preparing the “Soil”: The Premetastatic Niche

PubMed Central

Kaplan, Rosandra N.; Rafii, Shahin; Lyden, David

2010-01-01

Current focus on cancer metastasis has centered on the intrinsic factors regulating the cell autonomous homing of the tumor cells to the metastatic site. Specific up-regulation of fibronectin and clustering of bone marrow–derived cellular infiltrates coexpressing matrix metalloproteinases in distant tissue sites before tumor cell arrival are proving to be indispensable for the initial stages of metastasis. These bone marrow–derived hematopoietic progenitors that express vascular endothelial growth factor receptor 1 mobilize in response to the unique array of growth factors produced by the primary tumor. Their arrival in distant sites represents early changes in the local microenvironment, termed the “premetastatic niche,” which dictate the pattern of metastatic spread. Focus on the early cellular and molecular events in cancer dissemination and selectivity will likely lead to new approaches to detect and prevent metastasis at its earliest inception. PMID:17145848

The biochemistry of hematopoietic stem cell development.

PubMed

Kaimakis, P; Crisan, M; Dzierzak, E

2013-02-01

The cornerstone of the adult hematopoietic system and clinical treatments for blood-related disease is the cohort of hematopoietic stem cells (HSC) that is harbored in the adult bone marrow microenvironment. Interestingly, this cohort of HSCs is generated only during a short window of developmental time. In mammalian embryos, hematopoietic progenitor and HSC generation occurs within several extra- and intraembryonic microenvironments, most notably from 'hemogenic' endothelial cells lining the major vasculature. HSCs are made through a remarkable transdifferentiation of endothelial cells to a hematopoietic fate that is long-lived and self-renewable. Recent studies are beginning to provide an understanding of the biochemical signaling pathways and transcription factors/complexes that promote their generation. The focus of this review is on the biochemistry behind the generation of these potent long-lived self-renewing stem cells of the blood system. Both the intrinsic (master transcription factors) and extrinsic regulators (morphogens and growth factors) that affect the generation, maintenance and expansion of HSCs in the embryo will be discussed. The generation of HSCs is a stepwise process involving many developmental signaling pathways, morphogens and cytokines. Pivotal hematopoietic transcription factors are required for their generation. Interestingly, whereas these factors are necessary for HSC generation, their expression in adult bone marrow HSCs is oftentimes not required. Thus, the biochemistry and molecular regulation of HSC development in the embryo are overlapping, but differ significantly from the regulation of HSCs in the adult. HSC numbers for clinical use are limiting, and despite much research into the molecular basis of HSC regulation in the adult bone marrow, no panel of growth factors, interleukins and/or morphogens has been found to sufficiently increase the number of these important stem cells. An understanding of the biochemistry of HSC generation in the developing embryo provides important new knowledge on how these complex stem cells are made, sustained and expanded in the embryo to give rise to the complete adult hematopoietic system, thus stimulating novel strategies for producing increased numbers of clinically useful HSCs. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

Hematopoietic Stem Cells as a Novel Source of Dental Tissue Cells.

PubMed

Wilson, Katie R; Kang, In-Hong; Baliga, Uday; Xiong, Ying; Chatterjee, Shilpak; Moore, Emily; Parthiban, Beneta; Thyagarajan, Krishnamurthy; Borke, James L; Mehrotra, Shikhar; Kirkwood, Keith L; LaRue, Amanda C; Ogawa, Makio; Mehrotra, Meenal

2018-05-23

While earlier studies have suggested that cells positive for hematopoietic markers can be found in dental tissues, it has yet to be confirmed. To conclusively demonstrate this, we utilized a unique transgenic model in which all hematopoietic cells are green fluorescent protein + (GFP + ). Pulp, periodontal ligament (PDL) and alveolar bone (AvB) cell culture analysis demonstrated numerous GFP + cells, which were also CD45 + (indicating hematopoietic origin) and co-expressed markers of cellular populations in pulp (dentin matrix protein-1, dentin sialophosphoprotein, alpha smooth muscle actin [ASMA], osteocalcin), in PDL (periostin, ASMA, vimentin, osteocalcin) and in AvB (Runx-2, bone sialoprotein, alkaline phosphatase, osteocalcin). Transplantation of clonal population derived from a single GFP + hematopoietic stem cell (HSC), into lethally irradiated recipient mice, demonstrated numerous GFP + cells within dental tissues of recipient mice, which also stained for markers of cell populations in pulp, PDL and AvB (used above), indicating that transplanted HSCs can differentiate into cells in dental tissues. These hematopoietic-derived cells deposited collagen and can differentiate in osteogenic media, indicating that they are functional. Thus, our studies demonstrate, for the first time, that cells in pulp, PDL and AvB can have a hematopoietic origin, thereby opening new avenues of therapy for dental diseases and injuries.

MicroRNAs enriched in hematopoietic stem cells differentially regulate long-term hematopoietic output.

PubMed

O'Connell, Ryan M; Chaudhuri, Aadel A; Rao, Dinesh S; Gibson, William S J; Balazs, Alejandro B; Baltimore, David

2010-08-10

The production of blood cells depends on a rare hematopoietic stem-cell (HSC) population, but the molecular mechanisms underlying HSC biology remain incompletely understood. Here, we identify a subset of microRNAs (miRNAs) that is enriched in HSCs compared with other bone-marrow cells. An in vivo gain-of-function screen found that three of these miRNAs conferred a competitive advantage to engrafting hematopoietic cells, whereas other HSC miRNAs attenuated production of blood cells. Overexpression of the most advantageous miRNA, miR-125b, caused a dose-dependent myeloproliferative disorder that progressed to a lethal myeloid leukemia in mice and also enhanced hematopoietic engraftment in human immune system mice. Our study identifies an evolutionarily conserved subset of miRNAs that is expressed in HSCs and functions to modulate hematopoietic output.

The non-canonical Wnt receptor Ryk regulates hematopoietic stem cell repopulation in part by controlling proliferation and apoptosis.

PubMed

Famili, Farbod; Perez, Laura Garcia; Naber, Brigitta Ae; Noordermeer, Jasprina N; Fradkin, Lee G; Staal, Frank Jt

2016-11-24

The development of blood and immune cells requires strict control by various signaling pathways in order to regulate self-renewal, differentiation and apoptosis in stem and progenitor cells. Recent evidence indicates critical roles for the canonical and non-canonical Wnt pathways in hematopoiesis. The non-canonical Wnt pathway is important for establishment of cell polarity and cell migration and regulates apoptosis in the thymus. We here investigate the role of the non-canonical Wnt receptor Ryk in hematopoiesis and lymphoid development. We show that there are dynamic changes in Ryk expression during development and in different hematopoietic tissues. Functionally, Ryk regulates NK cell development in a temporal fashion. Moreover, Ryk-deficient mice show diminished, but not absent self-renewal of hematopoietic stem cells (HSC), via effects on mildly increased proliferation and apoptosis. Thus, Ryk deficiency in HSCs from fetal liver reduces their quiescence, leading to proliferation-induced apoptosis and decreased self-renewal.

Progressive Chromatin Condensation and H3K9 Methylation Regulate the Differentiation of Embryonic and Hematopoietic Stem Cells

DOE PAGES

Ugarte, Fernando; Sousae, Rebekah; Cinquin, Bertrand; ...

2015-10-17

Epigenetic regulation serves as the basis for stem cell differentiation into distinct cell types, but it is unclear how global epigenetic changes are regulated during this process. Here, we tested the hypothesis that global chromatin organization affects the lineage potential of stem cells and that manipulation of chromatin dynamics influences stem cell function. Using nuclease sensitivity assays, we found a progressive decrease in chromatin digestion among pluripotent embryonic stem cells (ESCs), multipotent hematopoietic stem cells (HSCs), and mature hematopoietic cells. Quantitative high-resolution microscopy revealed that ESCs contain significantly more euchromatin than HSCs, with a further reduction in mature cells. Increasedmore » cellular maturation also led to heterochromatin localization to the nuclear periphery. Functionally, prevention of heterochromatin formation by inhibition of the histone methyltransferase G9A resulted in delayed HSC differentiation. Lastly, our results demonstrate global chromatin rearrangements during stem cell differentiation and that heterochromatin formation by H3K9 methylation regulates HSC differentiation.« less

Progressive Chromatin Condensation and H3K9 Methylation Regulate the Differentiation of Embryonic and Hematopoietic Stem Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ugarte, Fernando; Sousae, Rebekah; Cinquin, Bertrand

Epigenetic regulation serves as the basis for stem cell differentiation into distinct cell types, but it is unclear how global epigenetic changes are regulated during this process. Here, we tested the hypothesis that global chromatin organization affects the lineage potential of stem cells and that manipulation of chromatin dynamics influences stem cell function. Using nuclease sensitivity assays, we found a progressive decrease in chromatin digestion among pluripotent embryonic stem cells (ESCs), multipotent hematopoietic stem cells (HSCs), and mature hematopoietic cells. Quantitative high-resolution microscopy revealed that ESCs contain significantly more euchromatin than HSCs, with a further reduction in mature cells. Increasedmore » cellular maturation also led to heterochromatin localization to the nuclear periphery. Functionally, prevention of heterochromatin formation by inhibition of the histone methyltransferase G9A resulted in delayed HSC differentiation. Lastly, our results demonstrate global chromatin rearrangements during stem cell differentiation and that heterochromatin formation by H3K9 methylation regulates HSC differentiation.« less

Modulation of occluding junctions alters the hematopoietic niche to trigger immune activation

PubMed Central

Khadilkar, Rohan J; Vogl, Wayne; Goodwin, Katharine

2017-01-01

Stem cells are regulated by signals from their microenvironment, or niche. During Drosophila hematopoiesis, a niche regulates prohemocytes to control hemocyte production. Immune challenges activate cell-signalling to initiate the cellular and innate immune response. Specifically, certain immune challenges stimulate the niche to produce signals that induce prohemocyte differentiation. However, the mechanisms that promote prohemocyte differentiation subsequent to immune challenges are poorly understood. Here we show that bacterial infection induces the cellular immune response by modulating occluding-junctions at the hematopoietic niche. Occluding-junctions form a permeability barrier that regulates the accessibility of prohemocytes to niche derived signals. The immune response triggered by infection causes barrier breakdown, altering the prohemocyte microenvironment to induce immune cell production. Moreover, genetically induced barrier ablation provides protection against infection by activating the immune response. Our results reveal a novel role for occluding-junctions in regulating niche-hematopoietic progenitor signalling and link this mechanism to immune cell production following infection. PMID:28841136

LRF-mediated Dll4 repression in erythroblasts is necessary for hematopoietic stem cell maintenance

PubMed Central

Lee, Sung-Uk; Maeda, Manami; Ishikawa, Yuichi; Li, Sierra Min; Wilson, Anne; Jubb, Adrian M.; Sakurai, Nagisa; Weng, Lihong; Fiorini, Emma; Radtke, Freddy; Yan, Minhong; MacDonald, H. Robson; Chen, Ching-Cheng

2013-01-01

Hematopoietic stem cells (HSCs) are the most primitive cells in the hematopoietic system and are under tight regulation for self-renewal and differentiation. Notch signals are essential for the emergence of definitive hematopoiesis in mouse embryos and are critical regulators of lymphoid lineage fate determination. However, it remains unclear how Notch regulates the balance between HSC self-renewal and differentiation in the adult bone marrow (BM). Here we report a novel mechanism that prevents HSCs from undergoing premature lymphoid differentiation in BM. Using a series of in vivo mouse models and functional HSC assays, we show that leukemia/lymphoma related factor (LRF) is necessary for HSC maintenance by functioning as an erythroid-specific repressor of Delta-like 4 (Dll4) expression. Lrf deletion in erythroblasts promoted up-regulation of Dll4 in erythroblasts, sensitizing HSCs to T-cell instructive signals in the BM. Our study reveals novel cross-talk between HSCs and erythroblasts, and sheds a new light on the regulatory mechanisms regulating the balance between HSC self-renewal and differentiation. PMID:23134786

Negative feedback on the effects of stem cell factor on hematopoiesis is partly mediated through neutral endopeptidase activity on substance P: a combined functional and proteomic study.

PubMed

Joshi, D D; Dang, A; Yadav, P; Qian, J; Bandari, P S; Chen, K; Donnelly, R; Castro, T; Gascon, P; Haider, A; Rameshwar, P

2001-11-01

Hematopoietic regulation is a complex but dynamic process regulated by intercellular and intracellular interactions within the bone marrow (BM) microenvironment. Through neurokinin-1 (NK-1) and NK-2 receptors, peptides (eg, substance P [SP]) encoded by the preprotachykinin-I gene mediate distinct hematopoietic effects. Cytokines, associated with hematopoietic stimulation, and SP regulate the expression of each other in BM mesenchymal and immune cells. Neutral endopeptidase (NEP) uses SP as a substrate to produce SP(1-4), which inhibits the proliferation of matured myeloid progenitor. This study determines whether the degradation of SP to SP(1-4) by endogenous NEP in BM stroma could be a feedback on hematopoietic stimulation by stem cell factor (SCF). SP(1-4) induced the production of transforming growth factor (TGF)-beta and tumor necrosis factor-alpha in BM stroma. TGF-beta production accounted for part of the inhibitory effects by SP(1-4) on the proliferation of early (granulocyte-macrophage colony-forming units) and late (long-term culture-initiating cells) hematopoietic progenitors. Enzyme-linked immunosorbent assays and/or protein-chip arrays indicated a timeline change of SP to SP(1-4) in BM stroma stimulated with SCF, which correlated with increase in NEP messenger RNA. Since SP and its fragment, SP(1-4), interact with the same receptor to mediate opposing hematopoietic effects, 2 interactive studies were done to understand the dual responses of NK-1: (1) a 3-dimensional molecular model of NK-1 and SP and (2) screening of a random dodecapeptide library for SP(1-4) interacting sites. The effects of SP(1-4) on hematopoietic progenitors and the timeline change of SP to SP(1-4), together with the 3-dimensional model, provide a partial explanation for the feedback on the stimulatory effects of SCF and SP on hematopoiesis.

Generating autologous hematopoietic cells from human-induced pluripotent stem cells through ectopic expression of transcription factors.

PubMed

Hwang, Yongsung; Broxmeyer, Hal E; Lee, Man Ryul

2017-07-01

Hematopoietic cell transplantation (HCT) is a successful treatment modality for patients with malignant and nonmalignant disorders, usually when no other treatment option is available. The cells supporting long-term reconstitution after HCT are the hematopoietic stem cells (HSCs), which can be limited in numbers. Moreover, finding an appropriate human leukocyte antigen-matched donor can be problematic. If HSCs can be stably produced in large numbers from autologous or allogeneic cell sources, it would benefit HCT. Induced pluripotent stem cells (iPSCs) established from patients' own somatic cells can be differentiated into hematopoietic cells in vitro. This review will highlight recent methods for regulating human (h) iPSC production of HSCs and more mature blood cells. Advancements in transcription factor-mediated regulation of the developmental stages of in-vivo hematopoietic lineage commitment have begun to provide an understanding of the molecular mechanism of hematopoiesis. Such studies involve not only directed differentiation in which transcription factors, specifically expressed in hematopoietic lineage-specific cells, are overexpressed in iPSCs, but also direct conversion in which transcription factors are introduced into patient-derived somatic cells which are dedifferentiated to hematopoietic cells. As iPSCs derived from patients suffering from genetically mutated diseases would express the same mutated genetic information, CRISPR-Cas9 gene editing has been utilized to differentiate genetically corrected iPSCs into normal hematopoietic cells. IPSCs provide a model for molecular understanding of disease, and also may function as a cell population for therapy. Efficient differentiation of patient-specific iPSCs into HSCs and progenitor cells is a potential means to overcome limitations of such cells for HCT, as well as for providing in-vitro drug screening templates as tissue-on-a-chip models.

Early Hematopoietic Zinc Finger Protein Prevents Tumor Cell Recognition by Natural Killer Cells1

PubMed Central

La Rocca, Rosanna; Fulciniti, Mariateresa; Lakshmikanth, Tadepally; Mesuraca, Maria; Ali, Talib Hassan; Mazzei, Valerio; Amodio, Nicola; Catalano, Lucio; Rotoli, Bruno; Ouerfelli, Ouathek; Grieco, Michele; Gulletta, Elio; Bond, Heather M.; Morrone, Giovanni; Ferrone, Soldano; Carbone, Ennio

2009-01-01

Early hematopoietic zinc finger/zinc finger protein 521 (EHZF/ZNF521) is a novel zinc finger protein expressed in hematopoietic stem and progenitor cells and is down-regulated during their differentiation. Its transcript is also abundant in some hematopoietic malignancies. Analysis of the changes in the antigenic profile of cells transfected with EHZF cDNA revealed up-regulation of HLA class I cell surface expression. This phenotypic change was associated with an increased level of HLA class I H chain, in absence of detectable changes in the expression of other Ag-processing machinery components. Enhanced resistance of target cells to NK cell-mediated cytotoxicity was induced by enforced expression of EHZF in the cervical carcinoma cell line HeLa and in the B lymphoblastoid cell line IM9. Preincubation of transfected cells with HLA class I Ag-specific mAb restored target cell susceptibility to NK cell-mediated lysis, indicating a specific role for HLA class I Ag up-regulation in the NK resistance induced by EHZF. A potential clinical significance of these findings is further suggested by the inverse correlation between EHZF and MHC class I expression levels, and autologous NK susceptibility of freshly explanted multiple myeloma cells. PMID:19342626

A Common Origin for B-1a and B-2 Lymphocytes in Clonal Pre- Hematopoietic Stem Cells.

PubMed

Hadland, Brandon K; Varnum-Finney, Barbara; Mandal, Pankaj K; Rossi, Derrick J; Poulos, Michael G; Butler, Jason M; Rafii, Shahin; Yoder, Mervin C; Yoshimoto, Momoko; Bernstein, Irwin D

2017-06-06

Recent evidence points to the embryonic emergence of some tissue-resident innate immune cells, such as B-1a lymphocytes, prior to and independently of hematopoietic stem cells (HSCs). However, whether the full hematopoietic repertoire of embryonic HSCs initially includes these unique lineages of innate immune cells has been difficult to assess due to lack of clonal assays that identify and assess HSC precursor (pre-HSC) potential. Here, by combining index sorting of single embryonic hemogenic precursors with in vitro HSC maturation and transplantation assays, we analyze emerging pre-HSCs at the single-cell level, revealing their unique stage-specific properties and clonal lineage potential. Remarkably, clonal pre-HSCs detected between E9.5 and E11.5 contribute to the complete B cell repertoire, including B-1a lymphocytes, revealing a previously unappreciated common precursor for all B cell lineages at the pre-HSC stage and a second embryonic origin for B-1a lymphocytes. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

The Differentiation Balance of Bone Marrow Mesenchymal Stem Cells Is Crucial to Hematopoiesis

PubMed Central

Zhang, Weiwei; Ran, Qian; Xiang, Yang; Zhong, Jiang F.; Li, Shengwen Calvin

2018-01-01

Bone marrow mesenchymal stem cells (BMSCs), the important component and regulator of bone marrow microenvironment, give rise to hematopoietic-supporting stromal cells and form hematopoietic niches for hematopoietic stem cells (HSCs). However, how BMSC differentiation affects hematopoiesis is poorly understood. In this review, we focus on the role of BMSC differentiation in hematopoiesis. We discussed the role of BMSCs and their progeny in hematopoiesis. We also examine the mechanisms that cause differentiation bias of BMSCs in stress conditions including aging, irradiation, and chemotherapy. Moreover, the differentiation balance of BMSCs is crucial to hematopoiesis. We highlight the negative effects of differentiation bias of BMSCs on hematopoietic recovery after bone marrow transplantation. Keeping the differentiation balance of BMSCs is critical for hematopoietic recovery. This review summarises current understanding about how BMSC differentiation affects hematopoiesis and its potential application in improving hematopoietic recovery after bone marrow transplantation. PMID:29765406

Global gene expression analyses of hematopoietic stem cell-like cell lines with inducible Lhx2 expression

PubMed Central

Richter, Karin; Wirta, Valtteri; Dahl, Lina; Bruce, Sara; Lundeberg, Joakim; Carlsson, Leif; Williams, Cecilia

2006-01-01

Background Expression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines. To address the molecular basis of Lhx2 function, we generated HSC-like cell lines where Lhx2 expression is regulated by a tet-on system and hence dependent on the presence of doxycyclin (dox). These cell lines efficiently down-regulate Lhx2 expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types. Results Global gene expression of these cell lines cultured in dox was compared to different time points after dox withdrawal using microarray technology. We identified 267 differentially expressed genes. The majority of the genes overlapping with HSC-specific databases were those down-regulated after turning off Lhx2 expression and a majority of the genes overlapping with those defined as late progenitor-specific genes were the up-regulated genes, suggesting that these cell lines represent a relevant model system for normal HSCs also at the level of global gene expression. Moreover, in situ hybridisations of several genes down-regulated after dox withdrawal showed overlapping expression patterns with Lhx2 in various tissues during embryonic development. Conclusion Global gene expression analysis of HSC-like cell lines with inducible Lhx2 expression has identified genes putatively linked to self-renewal / differentiation of HSCs, and function of Lhx2 in organ development and stem / progenitor cells of non-hematopoietic origin. PMID:16600034

Viral infections in transplant recipients.

PubMed

Razonable, R R; Eid, A J

2009-12-01

Solid organ and hematopoietic stem cell transplant recipients are uniquely predisposed to develop clinical illness, often with increased severity, due to a variety of common and opportunistic viruses. Patients may acquire viral infections from the donor (donor-derived infections), from reactivation of endogenous latent virus, or from the community. Herpes viruses, most notably cytomegalovirus and Epstein Barr virus, are the most common among opportunistic viral pathogens that cause infection after solid organ and hematopoietic stem cell transplantation. The polyoma BK virus causes opportunistic clinical syndromes predominantly in kidney and allogeneic hematopoietic stem cell transplant recipients. The agents of viral hepatitis B and C present unique challenges particularly among liver transplant recipients. Respiratory viral illnesses due to influenza, respiratory syncytial virus, and parainfluenza virus may affect all types of transplant recipients, although severe clinical disease is observed more commonly among lung and allogeneic hematopoietic stem cell transplant recipients. Less common viral infections affecting transplant recipients include those caused by adenoviruses, parvovirus B19, and West Nile virus. Treatment for viruses with proven effective antiviral drug therapies should be complemented by reduction in the degree of immunosuppression. For others with no proven antiviral drugs for therapy, reduction in the degree of immunosuppression remains as the sole effective strategy for management. Prevention of viral infections is therefore of utmost importance, and this may be accomplished through vaccination, antiviral strategies, and aggressive infection control measures.

Redox Regulation in Bone Marrow Failure

DTIC Science & Technology

2012-06-01

Fanconi anemia mutation for hematopoietic senescence. J Cell Sci, 2007. 120(Pt 9): p. 1572-83. 2. Aylon, Y. and M. Oren, Living with p53, dying of p53...aplastic anemia patients with a p38 MAPK inhibitor can restore defective hematopoietic activity, suggesting the critical role of p38 in bone marrow...hematopoietic stem cells, and eventually leading to bone marrow failure [7, 8] [9] [10]. On the other hand, treating aplastic anemia patients with a p38

Reactive oxygen species-dependent Toll/NF-κB activation in the Drosophila hematopoietic niche confers resistance to wasp parasitism.

PubMed

Louradour, Isabelle; Sharma, Anurag; Morin-Poulard, Ismael; Letourneau, Manon; Vincent, Alain; Crozatier, Michèle; Vanzo, Nathalie

2017-11-01

Hematopoietic stem/progenitor cells in the adult mammalian bone marrow ensure blood cell renewal. Their cellular microenvironment, called 'niche', regulates hematopoiesis both under homeostatic and immune stress conditions. In the Drosophila hematopoietic organ, the lymph gland, the posterior signaling center (PSC) acts as a niche to regulate the hematopoietic response to immune stress such as wasp parasitism. This response relies on the differentiation of lamellocytes, a cryptic cell type, dedicated to pathogen encapsulation and killing. Here, we establish that Toll/NF-κB pathway activation in the PSC in response to wasp parasitism non-cell autonomously induces the lymph gland immune response. Our data further establish a regulatory network where co-activation of Toll/NF-κB and EGFR signaling by ROS levels in the PSC/niche controls lymph gland hematopoiesis under parasitism. Whether a similar regulatory network operates in mammals to control emergency hematopoiesis is an open question.

The transcriptional landscape of hematopoietic stem cell ontogeny

PubMed Central

McKinney-Freeman, Shannon; Cahan, Patrick; Li, Hu; Lacadie, Scott A.; Huang, Hsuan-Ting; Curran, Matthew; Loewer, Sabine; Naveiras, Olaia; Kathrein, Katie L.; Konantz, Martina; Langdon, Erin M.; Lengerke, Claudia; Zon, Leonard I.; Collins, James J.; Daley, George Q.

2012-01-01

Transcriptome analysis of adult hematopoietic stem cells (HSC) and their progeny has revealed mechanisms of blood differentiation and leukemogenesis, but a similar analysis of HSC development is lacking. Here, we acquired the transcriptomes of developing HSC purified from >2500 murine embryos and adult mice. We found that embryonic hematopoietic elements clustered into three distinct transcriptional states characteristic of the definitive yolk sac, HSCs undergoing specification, and definitive HSCs. We applied a network biology-based analysis to reconstruct the gene regulatory networks of sequential stages of HSC development and functionally validated candidate transcriptional regulators of HSC ontogeny by morpholino-mediated knock-down in zebrafish embryos. Moreover, we found that HSCs from in vitro differentiated embryonic stem cells closely resemble definitive HSC, yet lack a Notch-signaling signature, likely accounting for their defective lymphopoiesis. Our analysis and web resource (http://hsc.hms.harvard.edu) will enhance efforts to identify regulators of HSC ontogeny and facilitate the engineering of hematopoietic specification. PMID:23122293

Adenosine signaling promotes hematopoietic stem and progenitor cell emergence

PubMed Central

Jing, Lili; Tamplin, Owen J.; Chen, Michael J.; Deng, Qing; Patterson, Shenia; Kim, Peter G.; Durand, Ellen M.; McNeil, Ashley; Green, Julie M.; Matsuura, Shinobu; Ablain, Julien; Brandt, Margot K.; Schlaeger, Thorsten M.; Huttenlocher, Anna; Daley, George Q.; Ravid, Katya

2015-01-01

Hematopoietic stem cells (HSCs) emerge from aortic endothelium via the endothelial-to-hematopoietic transition (EHT). The molecular mechanisms that initiate and regulate EHT remain poorly understood. Here, we show that adenosine signaling regulates hematopoietic stem and progenitor cell (HSPC) development in zebrafish embryos. The adenosine receptor A2b is expressed in the vascular endothelium before HSPC emergence. Elevated adenosine levels increased runx1+/cmyb+ HSPCs in the dorsal aorta, whereas blocking the adenosine pathway decreased HSPCs. Knockdown of A2b adenosine receptor disrupted scl+ hemogenic vascular endothelium and the subsequent EHT process. A2b adenosine receptor activation induced CXCL8 via cAMP–protein kinase A (PKA) and mediated hematopoiesis. We further show that adenosine increased multipotent progenitors in a mouse embryonic stem cell colony-forming assay and in embryonic day 10.5 aorta-gonad-mesonephros explants. Our results demonstrate that adenosine signaling plays an evolutionary conserved role in the first steps of HSPC formation in vertebrates. PMID:25870200

BAF180 regulates cellular senescence and hematopoietic stem cell homeostasis through p21

PubMed Central

Lee, Hyemin; Dai, Fangyan; Zhuang, Li; Xiao, Zhen-Dong; Kim, Jongchan; Zhang, Yilei; Ma, Li; You, M. James; Wang, Zhong; Gan, Boyi

2016-01-01

BAF180 (also called PBRM1), a subunit of the SWI/SNF complex, plays critical roles in the regulation of chromatin remodeling and gene transcription, and is frequently mutated in several human cancers. However, the role of mammalian BAF180 in tumor suppression and tissue maintenance in vivo remains largely unknown. Here, using a conditional somatic knockout approach, we explored the cellular and organismal functions of BAF180 in mouse. BAF180 deletion in primary mouse embryonic fibroblasts (MEFs) triggers profound cell cycle arrest, premature cellular senescence, without affecting DNA damage response or chromosomal integrity. While somatic deletion of BAF180 in adult mice does not provoke tumor development, BAF180 deficient mice exhibit defects in hematopoietic system characterized by progressive reduction of hematopoietic stem cells (HSCs), defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. BAF180 deletion results in elevated p21 expression in both MEFs and HSCs. Mechanistically, we showed that BAF180 binds to p21 promoter, and BAF180 deletion enhances the binding of modified histones associated with transcriptional activation on p21 promoter. Deletion of p21 rescues cell cycle arrest and premature senescence in BAF180 deficient MEFs, and partially rescues hematopoietic defects in BAF180 deficient mice. Together, our study identifies BAF180 as a critical regulator of cellular senescence and HSC homeostasis, which is at least partially regulated through BAF180-mediated suppression of p21 expression. Our results also suggest that senescence triggered by BAF180 inactivation may serve as a failsafe mechanism to restrain BAF180 deficiency-associated tumor development, providing a conceptual framework to further understand BAF180 function in tumor biology. PMID:26992241

E3 ligase FLRF (Rnf41) regulates differentiation of hematopoietic progenitors by governing steady-state levels of cytokine and retinoic acid receptors

PubMed Central

Jing, Xin; Infante, Jorge; Nachtman, Ronald G.; Jurecic, Roland

2008-01-01

Objective FLRF (Rnf41) gene was identified through screening of subtracted cDNA libraries form murine hematopoietic stem cells and progenitors. Subsequent work has revealed that FLRF acts as E3 ubiquitin ligase, and that it regulates steady-state levels of neuregulin receptor ErbB3, and participates in degradation of IAP protein BRUCE and parkin. The objective of this study was to start exploring the role of FLRF during hematopoiesis. Methods FLRF was over-expressed in a murine multipotent hematopoietic progenitor cell line EML, which can differentiate into almost all blood cell lineages, and in pro-B progenitor cell line BaF3. The impact of FLRF over-expression on EML cell differentiation into myelo-erythroid lineages was studied using hematopoietic colony-forming assays. The interaction of FLRF with cytokine receptors and receptor levels in control cells and EML and BaF3 cells over-expressing FLRF were examined with Western and immunoprecipitation. Results Remarkably, over-expression of FLRF significantly attenuated erythroid and myeloid differentiation of EML cells in response to cytokines Epo and IL-3, and retinoic acid (RA), and resulted in significant and constitutive decrease of steady-state levels of IL-3, Epo and RA receptor RARα in EML and BaF3 cells. Immunoprecipitation has revealed that FLRF interacts with IL-3, Epo and RARα receptors in EML and BaF3 cells, and that FLRF-mediated down-regulation of these receptors is ligand binding-independent. Conclusions The results of this study have revealed new FLRF-mediated pathway for ligand-independent receptor level regulation, and support the notion that through maintaining basal levels of cytokine receptors, FLRF is involved in the control of hematopoietic progenitor cell differentiation into myelo-erythroid lineages. PMID:18495327

An abnormal bone marrow microenvironment contributes to hematopoietic dysfunction in Fanconi anemia.

PubMed

Zhou, Yuan; He, Yongzheng; Xing, Wen; Zhang, Peng; Shi, Hui; Chen, Shi; Shi, Jun; Bai, Jie; Rhodes, Steven D; Zhang, Fengqui; Yuan, Jin; Yang, Xianlin; Zhu, Xiaofan; Li, Yan; Hanenberg, Helmut; Xu, Mingjiang; Robertson, Kent A; Yuan, Weiping; Nalepa, Grzegorz; Cheng, Tao; Clapp, D Wade; Yang, Feng-Chun

2017-06-01

Fanconi anemia is a complex heterogeneous genetic disorder with a high incidence of bone marrow failure, clonal evolution to acute myeloid leukemia and mesenchymal-derived congenital anomalies. Increasing evidence in Fanconi anemia and other genetic disorders points towards an interdependence of skeletal and hematopoietic development, yet the impact of the marrow microenvironment in the pathogenesis of the bone marrow failure in Fanconi anemia remains unclear. Here we demonstrated that mice with double knockout of both Fancc and Fancg genes had decreased bone formation at least partially due to impaired osteoblast differentiation from mesenchymal stem/progenitor cells. Mesenchymal stem/progenitor cells from the double knockout mice showed impaired hematopoietic supportive activity. Mesenchymal stem/progenitor cells of patients with Fanconi anemia exhibited similar cellular deficits, including increased senescence, reduced proliferation, impaired osteoblast differentiation and defective hematopoietic stem/progenitor cell supportive activity. Collectively, these studies provide unique insights into the physiological significance of mesenchymal stem/progenitor cells in supporting the marrow microenvironment, which is potentially of broad relevance in hematopoietic stem cell transplantation. Copyright© Ferrata Storti Foundation.

An abnormal bone marrow microenvironment contributes to hematopoietic dysfunction in Fanconi anemia

PubMed Central

Zhou, Yuan; He, Yongzheng; Xing, Wen; Zhang, Peng; Shi, Hui; Chen, Shi; Shi, Jun; Bai, Jie; Rhodes, Steven D.; Zhang, Fengqui; Yuan, Jin; Yang, Xianlin; Zhu, Xiaofan; Li, Yan; Hanenberg, Helmut; Xu, Mingjiang; Robertson, Kent A.; Yuan, Weiping; Nalepa, Grzegorz; Cheng, Tao; Clapp, D. Wade; Yang, Feng-Chun

2017-01-01

Fanconi anemia is a complex heterogeneous genetic disorder with a high incidence of bone marrow failure, clonal evolution to acute myeloid leukemia and mesenchymal-derived congenital anomalies. Increasing evidence in Fanconi anemia and other genetic disorders points towards an interdependence of skeletal and hematopoietic development, yet the impact of the marrow microenvironment in the pathogenesis of the bone marrow failure in Fanconi anemia remains unclear. Here we demonstrated that mice with double knockout of both Fancc and Fancg genes had decreased bone formation at least partially due to impaired osteoblast differentiation from mesenchymal stem/progenitor cells. Mesenchymal stem/progenitor cells from the double knockout mice showed impaired hematopoietic supportive activity. Mesenchymal stem/progenitor cells of patients with Fanconi anemia exhibited similar cellular deficits, including increased senescence, reduced proliferation, impaired osteoblast differentiation and defective hematopoietic stem/progenitor cell supportive activity. Collectively, these studies provide unique insights into the physiological significance of mesenchymal stem/progenitor cells in supporting the marrow microenvironment, which is potentially of broad relevance in hematopoietic stem cell transplantation. PMID:28341737

Quantitative stability of hematopoietic stem and progenitor cell clonal output in rhesus macaques receiving transplants

PubMed Central

Koelle, Samson J.

2017-01-01

Autologous transplantation of hematopoietic stem and progenitor cells lentivirally labeled with unique oligonucleotide barcodes flanked by sequencing primer targets enables quantitative assessment of the self-renewal and differentiation patterns of these cells in a myeloablative rhesus macaque model. Compared with other approaches to clonal tracking, this approach is highly quantitative and reproducible. We documented stable multipotent long-term hematopoietic clonal output of monocytes, granulocytes, B cells, and T cells from a polyclonal pool of hematopoietic stem and progenitor cells in 4 macaques observed for up to 49 months posttransplantation. A broad range of clonal behaviors characterized by contribution level and biases toward certain cell types were extremely stable over time. Correlations between granulocyte and monocyte clonalities were greatest, followed by correlations between these cell types and B cells. We also detected quantitative expansion of T cell–biased clones consistent with an adaptive immune response. In contrast to recent data from a nonquantitative murine model, there was little evidence for clonal succession after initial hematopoietic reconstitution. These findings have important implications for human hematopoiesis, given the similarities between macaque and human physiologies. PMID:28087539

Biomechanical force in blood development: extrinsic physical cues drive pro-hematopoietic signaling

PubMed Central

Lee, Hyun Jung; Li, Nan; Evans, Siobahn M.; Diaz, Miguel F.; Wenzel, Pamela L.

2013-01-01

The hematopoietic system is dynamic during development and in adulthood, undergoing countless spatial and temporal transitions during the course of one’s life. Microenvironmental cues in the many unique hematopoietic niches differ, characterized by distinct soluble molecules, membrane-bound factors, and biophysical features that meet the changing needs of the blood system. Research from the last decade has revealed the importance of substrate elasticity and biomechanical force in determination of stem cell fate. Our understanding of the role of these factors in hematopoiesis is still relatively poor; however, the developmental origin of blood cells from the endothelium promts a model for comparison. Many endothelial mechanical sensors and second messenger systems may also determine hematopoietic stem cell fate, self renewal, and homing behaviors. Further, the intimate contact of hematopoietic cells with mechanosensitive cell types, including osteoblasts, endothelial cells, mesenchymal stem cells, and pericytes, places them in close proximity to paracrine signaling downstream of mechanical signals. The objective of this review is to present an overview of the sensors and intracellular signaling pathways activated by mechanical cues and highlight the role of mechanotransductive pathways in hematopoiesis. PMID:23850217

Ikaros gene expression and leukemia.

PubMed

Tonnelle, Cécile; Calmels, Boris; Maroc, Christine; Gabert, Jean; Chabannon, Christian

2002-01-01

The Ikaros (Ik) protein, or LyF1, was initially described as a protein binding to regulatory sequences of a number of genes expressed in murine lymphoid cells. Ikaros is a critical regulator of normal hematopoietic stem cell differentiation, as evidenced by dramatic defects in the lymphoid compartments, in homozygous animals with gene inactivation. Because differential splicing produces multiple isoforms with potentially different functions, Ikaros provides a unique model to study how post-transcriptional mechanisms may be involved in neoplastic processes. Indeed, several groups including ours have underlined evidences that expression of different Ikaros isoforms vary among different types of leukemias. The predominance of short isoforms in certain subsets is intriguing. Here, additional observations reinforced the hypothesis that Ikaros expression may be deregulated in human leukemias. Whether this is a cause or a consequence of the leukemic process remains speculative. Other human diseases however, provide examples of abnormal post-transcriptional regulations that have been further characterized.

The miR-23a~27a~24-2 microRNA cluster buffers transcription and signaling pathways during hematopoiesis

PubMed Central

Kurkewich, Jeffrey L.; Klopfenstein, Nathan; Wood, Christian; Boucher, Austin

2017-01-01

MicroRNA cluster mirn23a has previously been shown to promote myeloid development at the expense of lymphoid development in overexpression and knockout mouse models. This polarization is observed early in hematopoietic development, with an increase in common lymphoid progenitors (CLPs) and a decrease in all myeloid progenitor subsets in adult bone marrow. The pool size of multipotential progenitors (MPPs) is unchanged; however, in this report we observe by flow cytometry that polarized subsets of MPPs are changed in the absence of mirn23a. Additionally, in vitro culture of MPPs and sorted MPP transplants showed that these cells have decreased myeloid and increased lymphoid potential in vitro and in vivo. We investigated the mechanism by which mirn23a regulates hematopoietic differentiation and observed that mirn23a promotes myeloid development of hematopoietic progenitors through regulation of hematopoietic transcription factors and signaling pathways. Early transcription factors that direct the commitment of MPPs to CLPs (Ikzf1, Runx1, Satb1, Bach1 and Bach2) are increased in the absence of mirn23a miRNAs as well as factors that commit the CLP to the B cell lineage (FoxO1, Ebf1, and Pax5). Mirn23a appears to buffer transcription factor levels so that they do not stochastically reach a threshold level to direct differentiation. Intriguingly, mirn23a also inversely regulates the PI3 kinase (PI3K)/Akt and BMP/Smad signaling pathways. Pharmacological inhibitor studies, coupled with dominant active/dominant negative biochemical experiments, show that both signaling pathways are critical to mirn23a’s regulation of hematopoietic differentiation. Lastly, consistent with mirn23a being a physiological inhibitor of B cell development, we observed that the essential B cell transcription factor EBF1 represses expression of mirn23a. In summary, our data demonstrates that mirn23a regulates a complex array of transcription and signaling pathways to modulate adult hematopoiesis. PMID:28704388

What do we know about the participation of hematopoietic stem cells in hematopoiesis?

PubMed

Drize, Nina; Petinati, Nataliya

2015-01-01

The demonstrated presence in adult tissues of cells with sustained tissue regenerative potential has given rise to the concept of tissue stem cells. Assays to detect and measure such cells indicate that they have enormous proliferative potential and usually an ability to produce all or many of the mature cell types that define the specialized functionality of the tissue. In the hematopoietic system, one or only a few cells can restore lifelong hematopoiesis of the whole organism. To what extent is the maintenance of hematopoietic stem cells required during normal hematopoiesis? How does the constant maintenance of hematopoiesis occur and what is the behavior of the hematopoietic stem cells in the normal organism? How many of the hematopoietic stem cells are created during the development of the organism? How many hematopoietic stem cells are generating more mature progeny at any given moment? What happens to the population of hematopoietic stem cells in aging? This review will attempt to describe the results of recent research which contradict some of the ideas established over the past 30 years about how hematopoiesis is regulated.

Young endothelial cells revive aging blood.

PubMed

Chang, Vivian Y; Termini, Christina M; Chute, John P

2017-11-01

The hematopoietic system declines with age, resulting in decreased hematopoietic stem cell (HSC) self-renewal capacity, myeloid skewing, and immune cell depletion. Aging of the hematopoietic system is associated with an increased incidence of myeloid malignancies and a decline in adaptive immunity. Therefore, strategies to rejuvenate the hematopoietic system have important clinical implications. In this issue of the JCI, Poulos and colleagues demonstrate that infusions of bone marrow (BM) endothelial cells (ECs) from young mice promoted HSC self-renewal and restored immune cell content in aged mice. Additionally, delivery of young BM ECs along with HSCs following total body irradiation improved HSC engraftment and enhanced survival. These results suggest an important role for BM endothelial cells (ECs) in regulating hematopoietic aging and support further research to identify the rejuvenating factors elaborated by BM ECs that restore HSC function and the immune repertoire in aged mice.

Developmental regulation of myeloerythroid progenitor function by the Lin28b–let-7–Hmga2 axis

PubMed Central

Rowe, R. Grant; Wang, Leo D.; Coma, Silvia; Pearson, Daniel S.; Nguyen, Phi T.; Wagers, Amy J.

2016-01-01

For appropriate development, tissue and organ system morphogenesis and maturation must occur in synchrony with the overall developmental requirements of the host. Mistiming of such developmental events often results in disease. The hematopoietic system matures from the fetal state, characterized by robust erythrocytic output that supports prenatal growth in the hypoxic intrauterine environment, to the postnatal state wherein granulocytes predominate to provide innate immunity. Regulation of the developmental timing of these myeloerythroid states is not well understood. In this study, we find that expression of the heterochronic factor Lin28b decreases in common myeloid progenitors during hematopoietic maturation to adulthood in mice. This decrease in Lin28b coincides with accumulation of mature let-7 microRNAs, whose biogenesis is regulated by Lin28 proteins. We find that inhibition of let-7 in the adult hematopoietic system recapitulates fetal erythroid-dominant hematopoiesis. Conversely, deletion of Lin28b or ectopic activation of let-7 microRNAs in the fetal state induces a shift toward adult-like myeloid-dominant output. Furthermore, we identify Hmga2 as an effector of this genetic switch. These studies provide the first detailed analysis of the roles of endogenous Lin28b and let-7 in the timing of hematopoietic states during development. PMID:27401346

EVI2B is a C/EBPα target gene required for granulocytic differentiation and functionality of hematopoietic progenitors.

PubMed

Zjablovskaja, Polina; Kardosova, Miroslava; Danek, Petr; Angelisova, Pavla; Benoukraf, Touati; Wurm, Alexander A; Kalina, Tomas; Sian, Stephanie; Balastik, Martin; Delwel, Ruud; Brdicka, Tomas; Tenen, Daniel G; Behre, Gerhard; Fiore, Fréderic; Malissen, Bernard; Horejsi, Vaclav; Alberich-Jorda, Meritxell

2017-04-01

Development of hematopoietic populations through the process of differentiation is critical for proper hematopoiesis. The transcription factor CCAAT/enhancer binding protein alpha (C/EBPα) is a master regulator of myeloid differentiation, and the identification of C/EBPα target genes is key to understand this process. Here we identified the Ecotropic Viral Integration Site 2B (EVI2B) gene as a direct target of C/EBPα. We showed that the product of the gene, the transmembrane glycoprotein EVI2B (CD361), is abundantly expressed on the surface of primary hematopoietic cells, the highest levels of expression being reached in mature granulocytes. Using shRNA-mediated downregulation of EVI2B in human and murine cell lines and in primary hematopoietic stem and progenitor cells, we demonstrated impaired myeloid lineage development and altered progenitor functions in EVI2B-silenced cells. We showed that the compromised progenitor functionality in Evi2b-depleted cells can be in part explained by deregulation of cell proliferation and apoptosis. In addition, we generated an Evi2b knockout murine model and demonstrated altered properties of hematopoietic progenitors, as well as impaired G-CSF dependent myeloid colony formation in the knockout cells. Remarkably, we found that EVI2B is significantly downregulated in human acute myeloid leukemia samples characterized by defects in CEBPA. Altogether, our data demonstrate that EVI2B is a downstream target of C/EBPα, which regulates myeloid differentiation and functionality of hematopoietic progenitors.

CD146 expression on primary nonhematopoietic bone marrow stem cells is correlated with in situ localization

PubMed Central

Tormin, Ariane; Li, Ou; Brune, Jan Claas; Walsh, Stuart; Schütz, Birgit; Ehinger, Mats; Ditzel, Nicholas; Kassem, Moustapha

2011-01-01

Nonhematopoietic bone marrow mesenchymal stem cells (BM-MSCs) are of central importance for bone marrow stroma and the hematopoietic environment. However, the exact phenotype and anatomical distribution of specified MSC populations in the marrow are unknown. We characterized the phenotype of primary human BM-MSCs and found that all assayable colony-forming units-fibroblast (CFU-Fs) were highly and exclusively enriched not only in the lin−/CD271+/CD45−/CD146+ stem-cell fraction, but also in lin−/CD271+/CD45−/CD146−/low cells. Both populations, regardless of CD146 expression, shared a similar phenotype and genotype, gave rise to typical cultured stromal cells, and formed bone and hematopoietic stroma in vivo. Interestingly, CD146 was up-regulated in normoxia and down-regulated in hypoxia. This was correlated with in situ localization differences, with CD146 coexpressing reticular cells located in perivascular regions, whereas bone-lining MSCs expressed CD271 alone. In both regions, CD34+ hematopoietic stem/progenitor cells were located in close proximity to MSCs. These novel findings show that the expression of CD146 differentiates between perivascular versus endosteal localization of non-hematopoietic BM-MSC populations, which may be useful for the study of the hematopoietic environment. PMID:21415267

Ikaros-Notch axis in host hematopoietic cells regulates experimental graft-versus-host disease

PubMed Central

Toubai, Tomomi; Sun, Yaping; Tawara, Isao; Friedman, Ann; Liu, Chen; Evers, Rebecca; Nieves, Evelyn; Malter, Chelsea; Chockley, Peter; Maillard, Ivan; Winandy, Susan

2011-01-01

Host hematopoietically derived APCs play a vital role in the initiation of GVH responses. However, the APC autonomous molecular mechanisms that are critical for the induction of GVHD are not known. We report here that the Ikaros-Notch axis in host hematopoietically derived APCs regulates the severity of acute GVHD across multiple clinically relevant murine models of experimental bone marrow transplantation. In the present study, Ikaros deficiency (Ik−/−) limited to host hematopoietically derived APCs enhanced donor T-cell expansion and intensified acute GVHD, as determined by survival and other GVHD-specific parameters. The Ik−/− conventional CD8+ and CD8−CD11c+ dendritic cells (DCs), the most potent APCs, showed no increase in the expression of activation markers or in response to TLR stimulation compared with wild-type controls. However, Ik−/− DCs demonstrated an enhanced stimulation of allogeneic T cells. Deficiency of Ikaros in the conventional CD8+ and CD8−CD11c+ DCs was associated with an increase in Notch signaling, the blockade of which mitigated the enhanced in vitro and in vivo allostimulatory capacity. Therefore, the Ikaros-Notch axis is a novel pathway that modulates DC biology in general, and targeting this pathway in host hematopoietically derived APCs may reduce GVHD. PMID:21471527

Cell Fusion Reprogramming Leads to a Specific Hepatic Expression Pattern during Mouse Bone Marrow Derived Hepatocyte Formation In Vivo

PubMed Central

Arza, Elvira; Alvarez-Barrientos, Alberto; Fabregat, Isabel; Garcia-Bravo, Maria; Meza, Nestor W.; Segovia, Jose C.

2012-01-01

The fusion of bone marrow (BM) hematopoietic cells with hepatocytes to generate BM derived hepatocytes (BMDH) is a natural process, which is enhanced in damaged tissues. However, the reprogramming needed to generate BMDH and the identity of the resultant cells is essentially unknown. In a mouse model of chronic liver damage, here we identify a modification in the chromatin structure of the hematopoietic nucleus during BMDH formation, accompanied by the loss of the key hematopoietic transcription factor PU.1/Sfpi1 (SFFV proviral integration 1) and gain of the key hepatic transcriptional regulator HNF-1A homeobox A (HNF-1A/Hnf1a). Through genome-wide expression analysis of laser captured BMDH, a differential gene expression pattern was detected and the chromatin changes observed were confirmed at the level of chromatin regulator genes. Similarly, Tranforming Growth Factor-β1 (TGF-β1) and neurotransmitter (e.g. Prostaglandin E Receptor 4 [Ptger4]) pathway genes were over-expressed. In summary, in vivo BMDH generation is a process in which the hematopoietic cell nucleus changes its identity and acquires hepatic features. These BMDHs have their own cell identity characterized by an expression pattern different from hematopoietic cells or hepatocytes. The role of these BMDHs in the liver requires further investigation. PMID:22457803

Maternal high-fat diet and obesity compromise fetal hematopoiesis

PubMed Central

Kamimae-Lanning, Ashley N.; Krasnow, Stephanie M.; Goloviznina, Natalya A.; Zhu, Xinxia; Roth-Carter, Quinn R.; Levasseur, Peter R.; Jeng, Sophia; McWeeney, Shannon K.; Kurre, Peter; Marks, Daniel L.

2014-01-01

Objective Recent evidence indicates that the adult hematopoietic system is susceptible to diet-induced lineage skewing. It is not known whether the developing hematopoietic system is subject to metabolic programming via in utero high-fat diet (HFD) exposure, an established mechanism of adult disease in several organ systems. We previously reported substantial losses in offspring liver size with prenatal HFD. As the liver is the main hematopoietic organ in the fetus, we asked whether the developmental expansion of the hematopoietic stem and progenitor cell (HSPC) pool is compromised by prenatal HFD and/or maternal obesity. Methods We used quantitative assays, progenitor colony formation, flow cytometry, transplantation, and gene expression assays with a series of dietary manipulations to test the effects of gestational high-fat diet and maternal obesity on the day 14.5 fetal liver hematopoietic system. Results Maternal obesity, particularly when paired with gestational HFD, restricts physiological expansion of fetal HSPCs while promoting the opposing cell fate of differentiation. Importantly, these effects are only partially ameliorated by gestational dietary adjustments for obese dams. Competitive transplantation reveals compromised repopulation and myeloid-biased differentiation of HFD-programmed HSPCs to be a niche-dependent defect, apparent in HFD-conditioned male recipients. Fetal HSPC deficiencies coincide with perturbations in genes regulating metabolism, immune and inflammatory processes, and stress response, along with downregulation of genes critical for hematopoietic stem cell self-renewal and activation of pathways regulating cell migration. Conclusions Our data reveal a previously unrecognized susceptibility to nutritional and metabolic developmental programming in the fetal HSPC compartment, which is a partially reversible and microenvironment-dependent defect perturbing stem and progenitor cell expansion and hematopoietic lineage commitment. PMID:25685687

Many layers of embryonic hematopoiesis: new insights into B-cell ontogeny and the origin of hematopoietic stem cells.

PubMed

Hadland, Brandon; Yoshimoto, Momoko

2018-04-01

In adult hematopoiesis, the hematopoietic stem cell (HSC) sits at the top of a hierarchy of hematopoietic progenitors responsible for generating the diverse repertoire of blood and immune cells. During embryonic development, however, the initial waves of hematopoiesis provide the first functioning blood cells of the developing embryo, such as primitive erythrocytes arising in the yolk sac, independently of HSCs. In the field of developmental immunology, it has been recognized that some components of the immune system, such as B-1a lymphocytes, are uniquely produced during the embryonic and neonatal period, suggesting a "layered" development of immunity. Several recent studies have shed new light on the developmental origin of the layered immune system, suggesting complex and sometimes multiple contributions to unique populations of innate-like immune cells from both fetal HSCs and earlier HSC-independent progenitors. In this review, we will attempt to synthesize these studies to provide an integrated model of developmental hematopoiesis and layered immunity that may offer new insights into the origin of HSCs. Copyright © 2018 ISEH – Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

Fumarate hydratase is a critical metabolic regulator of hematopoietic stem cell functions.

PubMed

Guitart, Amelie V; Panagopoulou, Theano I; Villacreces, Arnaud; Vukovic, Milica; Sepulveda, Catarina; Allen, Lewis; Carter, Roderick N; van de Lagemaat, Louie N; Morgan, Marcos; Giles, Peter; Sas, Zuzanna; Gonzalez, Marta Vila; Lawson, Hannah; Paris, Jasmin; Edwards-Hicks, Joy; Schaak, Katrin; Subramani, Chithra; Gezer, Deniz; Armesilla-Diaz, Alejandro; Wills, Jimi; Easterbrook, Aaron; Coman, David; So, Chi Wai Eric; O'Carroll, Donal; Vernimmen, Douglas; Rodrigues, Neil P; Pollard, Patrick J; Morton, Nicholas M; Finch, Andrew; Kranc, Kamil R

2017-03-06

Strict regulation of stem cell metabolism is essential for tissue functions and tumor suppression. In this study, we investigated the role of fumarate hydratase (Fh1), a key component of the mitochondrial tricarboxylic acid (TCA) cycle and cytosolic fumarate metabolism, in normal and leukemic hematopoiesis. Hematopoiesis-specific Fh1 deletion (resulting in endogenous fumarate accumulation and a genetic TCA cycle block reflected by decreased maximal mitochondrial respiration) caused lethal fetal liver hematopoietic defects and hematopoietic stem cell (HSC) failure. Reexpression of extramitochondrial Fh1 (which normalized fumarate levels but not maximal mitochondrial respiration) rescued these phenotypes, indicating the causal role of cellular fumarate accumulation. However, HSCs lacking mitochondrial Fh1 (which had normal fumarate levels but defective maximal mitochondrial respiration) failed to self-renew and displayed lymphoid differentiation defects. In contrast, leukemia-initiating cells lacking mitochondrial Fh1 efficiently propagated Meis1 / Hoxa9 -driven leukemia. Thus, we identify novel roles for fumarate metabolism in HSC maintenance and hematopoietic differentiation and reveal a differential requirement for mitochondrial Fh1 in normal hematopoiesis and leukemia propagation. © 2017 Guitart et al.

Identification of transcriptional regulators in the mouse immune system

PubMed Central

Jojic, Vladimir; Shay, Tal; Sylvia, Katelyn; Zuk, Or; Sun, Xin; Kang, Joonsoo; Regev, Aviv; Koller, Daphne

2013-01-01

The differentiation of hematopoietic stem cells into immune cells has been extensively studied in mammals, but the transcriptional circuitry controlling it is still only partially understood. Here, the Immunological Genome Project gene expression profiles across mouse immune lineages allowed us to systematically analyze these circuits. Using a computational algorithm called Ontogenet, we uncovered differentiation-stage specific regulators of mouse hematopoiesis, identifying many known hematopoietic regulators, and 175 new candidate regulators, their target genes, and the cell types in which they act. Among the novel regulators, we highlight the role of ETV5 in γδT cells differntiation. Since the transcriptional program of human and mouse cells is highly conserved1, it is likely that many lessons learned from the mouse model apply to humans. PMID:23624555

Zebrafish Caudal Haematopoietic Embryonic Stromal Tissue (CHEST) Cells Support Haematopoiesis.

PubMed

Wolf, Anja; Aggio, Julian; Campbell, Clyde; Wright, Francis; Marquez, Gabriel; Traver, David; Stachura, David L

2017-03-16

Haematopoiesis is an essential process in early vertebrate development that occurs in different distinct spatial locations in the embryo that shift over time. These different sites have distinct functions: in some anatomical locations specific hematopoietic stem and progenitor cells (HSPCs) are generated de novo. In others, HSPCs expand. HSPCs differentiate and renew in other locations, ensuring homeostatic maintenance. These niches primarily control haematopoiesis through a combination of cell-to-cell signalling and cytokine secretion that elicit unique biological effects in progenitors. To understand the molecular signals generated by these niches, we report the generation of caudal hematopoietic embryonic stromal tissue (CHEST) cells from 72-hours post fertilization (hpf) caudal hematopoietic tissue (CHT), the site of embryonic HSPC expansion in fish. CHEST cells are a primary cell line with perivascular endothelial properties that expand hematopoietic cells in vitro. Morphological and transcript analysis of these cultures indicates lymphoid, myeloid, and erythroid differentiation, indicating that CHEST cells are a useful tool for identifying molecular signals critical for HSPC proliferation and differentiation in the zebrafish. These findings permit comparison with other temporally and spatially distinct haematopoietic-supportive zebrafish niches, as well as with mammalian haematopoietic-supportive cells to further the understanding of the evolution of the vertebrate hematopoietic system.

ERα promotes murine hematopoietic regeneration through the Ire1α-mediated unfolded protein response

PubMed Central

Chapple, Richard H; Hu, Tianyuan; Tseng, Yu-Jung; Liu, Lu; Kitano, Ayumi; Luu, Victor; Hoegenauer, Kevin A; Iwawaki, Takao; Li, Qing

2018-01-01

Activation of the unfolded protein response (UPR) sustains protein homeostasis (proteostasis) and plays a fundamental role in tissue maintenance and longevity of organisms. Long-range control of UPR activation has been demonstrated in invertebrates, but such mechanisms in mammals remain elusive. Here, we show that the female sex hormone estrogen regulates the UPR in hematopoietic stem cells (HSCs). Estrogen treatment increases the capacity of HSCs to regenerate the hematopoietic system upon transplantation and accelerates regeneration after irradiation. We found that estrogen signals through estrogen receptor α (ERα) expressed in hematopoietic cells to activate the protective Ire1α-Xbp1 branch of the UPR. Further, ERα-mediated activation of the Ire1α-Xbp1 pathway confers HSCs with resistance against proteotoxic stress and promotes regeneration. Our findings reveal a systemic mechanism through which HSC function is augmented for hematopoietic regeneration. PMID:29451493

Neural Crossroads in the Hematopoietic Stem Cell Niche.

PubMed

Agarwala, Sobhika; Tamplin, Owen J

2018-05-29

The hematopoietic stem cell (HSC) niche supports steady-state hematopoiesis and responds to changing needs during stress and disease. The nervous system is an important regulator of the niche, and its influence is established early in development when stem cells are specified. Most research has focused on direct innervation of the niche, however recent findings show there are different modes of neural control, including globally by the central nervous system (CNS) and hormone release, locally by neural crest-derived mesenchymal stem cells, and intrinsically by hematopoietic cells that express neural receptors and neurotransmitters. Dysregulation between neural and hematopoietic systems can contribute to disease, however new therapeutic opportunities may be found among neuroregulator drugs repurposed to support hematopoiesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hematopoietic stem cells burn fat to prevent exhaustion.

PubMed

Lallemand-Breitenbach, Valerie; de Thé, Hugues

2012-10-05

Ito et al. (2012) recently report in Nature Medicine that fatty acid oxidation (FAO) regulated by PPARδ controls asymmetric division in hematopoietic stem cells (HSCs). This metabolic mechanism prevents HSC exhaustion and is downstream of the promyelocytic leukemia protein PML, suggesting therapeutic implications for HSC function and disease. Copyright © 2012 Elsevier Inc. All rights reserved.

Expansion on Stromal Cells Preserves the Undifferentiated State of Human Hematopoietic Stem Cells Despite Compromised Reconstitution Ability

PubMed Central

Magnusson, Mattias; Sierra, Maria I.; Sasidharan, Rajkumar; Prashad, Sacha L.; Romero, Melissa; Saarikoski, Pamela; Van Handel, Ben; Huang, Andy; Li, Xinmin; Mikkola, Hanna K. A.

2013-01-01

Lack of HLA-matched hematopoietic stem cells (HSC) limits the number of patients with life-threatening blood disorders that can be treated by HSC transplantation. So far, insufficient understanding of the regulatory mechanisms governing human HSC has precluded the development of effective protocols for culturing HSC for therapeutic use and molecular studies. We defined a culture system using OP9M2 mesenchymal stem cell (MSC) stroma that protects human hematopoietic stem/progenitor cells (HSPC) from differentiation and apoptosis. In addition, it facilitates a dramatic expansion of multipotent progenitors that retain the immunophenotype (CD34+CD38−CD90+) characteristic of human HSPC and proliferative potential over several weeks in culture. In contrast, transplantable HSC could be maintained, but not significantly expanded, during 2-week culture. Temporal analysis of the transcriptome of the ex vivo expanded CD34+CD38−CD90+ cells documented remarkable stability of most transcriptional regulators known to govern the undifferentiated HSC state. Nevertheless, it revealed dynamic fluctuations in transcriptional programs that associate with HSC behavior and may compromise HSC function, such as dysregulation of PBX1 regulated genetic networks. This culture system serves now as a platform for modeling human multilineage hematopoietic stem/progenitor cell hierarchy and studying the complex regulation of HSC identity and function required for successful ex vivo expansion of transplantable HSC. PMID:23342037

E3 ligase FLRF (Rnf41) regulates differentiation of hematopoietic progenitors by governing steady-state levels of cytokine and retinoic acid receptors.

PubMed

Jing, Xin; Infante, Jorge; Nachtman, Ronald G; Jurecic, Roland

2008-09-01

FLRF (Rnf41) gene was identified through screening of subtracted cDNA libraries form murine hematopoietic stem cells and progenitors. Subsequent work has revealed that FLRF acts as E3 ubiquitin ligase, and that it regulates steady-state levels of neuregulin receptor ErbB3 and participates in degradation of IAP protein BRUCE and parkin. The objective of this study was to start exploring the role of FLRF during hematopoiesis. FLRF was overexpressed in a murine multipotent hematopoietic progenitor cell line EML, which can differentiate into almost all blood cell lineages, and in pro-B progenitor cell line BaF3. The impact of FLRF overexpression on EML cell differentiation into myeloerythroid lineages was studied using hematopoietic colony-forming assays. The interaction of FLRF with cytokine receptors and receptor levels in control cells and EML and BaF3 cells overexpressing FLRF were examined with Western and immunoprecipitation. Remarkably, overexpression of FLRF significantly attenuated erythroid and myeloid differentiation of EML cells in response to cytokines erythropoietin (EPO) and interleukin-3 (IL-3), and retinoic acid (RA), and resulted in significant and constitutive decrease of steady-state levels of IL-3, EPO, and RA receptor-alpha (RARalpha) in EML and BaF3 cells. Immunoprecipitation has revealed that FLRF interacts with IL-3, EPO, and RARalpha receptors in EML and BaF3 cells, and that FLRF-mediated downregulation of these receptors is ligand binding-independent. The results of this study have revealed new FLRF-mediated pathway for ligand-independent receptor level regulation, and support the notion that through maintaining basal levels of cytokine receptors, FLRF is involved in the control of hematopoietic progenitor cell differentiation into myeloerythroid lineages.

Distinct Molecular Signature of Murine Fetal Liver and Adult Hematopoietic Stem Cells Identify Novel Regulators of Hematopoietic Stem Cell Function

PubMed Central

Manesia, Javed K.; Franch, Monica; Tabas-Madrid, Daniel; Nogales-Cadenas, Ruben; Vanwelden, Thomas; Van Den Bosch, Elisa; Xu, Zhuofei; Pascual-Montano, Alberto; Khurana, Satish; Verfaillie, Catherine M.

2018-01-01

During ontogeny, fetal liver (FL) acts as a major site for hematopoietic stem cell (HSC) maturation and expansion, whereas HSCs in the adult bone marrow (ABM) are largely quiescent. HSCs in the FL possess faster repopulation capacity as compared with ABM HSCs. However, the molecular mechanism regulating the greater self-renewal potential of FL HSCs has not yet extensively been assessed. Recently, we published RNA sequencing-based gene expression analysis on FL HSCs from 14.5-day mouse embryo (E14.5) in comparison to the ABM HSCs. We reanalyzed these data to identify key transcriptional regulators that play important roles in the expansion of HSCs during development. The comparison of FL E14.5 with ABM HSCs identified more than 1,400 differentially expressed genes. More than 200 genes were shortlisted based on the gene ontology (GO) annotation term “transcription.” By morpholino-based knockdown studies in zebrafish, we assessed the function of 18 of these regulators, previously not associated with HSC proliferation. Our studies identified a previously unknown role for tdg, uhrf1, uchl5, and ncoa1 in the emergence of definitive hematopoiesis in zebrafish. In conclusion, we demonstrate that identification of genes involved in transcriptional regulation differentially expressed between expanding FL HSCs and quiescent ABM HSCs, uncovers novel regulators of HSC function. PMID:27958775

Aid is a key regulator of myeloid/erythroid differentiation and DNA methylation in hematopoietic stem/progenitor cells

PubMed Central

Kunimoto, Hiroyoshi; McKenney, Anna Sophia; Meydan, Cem; Shank, Kaitlyn; Nazir, Abbas; Rapaport, Franck; Durham, Benjamin; Garrett-Bakelman, Francine E.; Pronier, Elodie; Shih, Alan H.; Melnick, Ari; Chaudhuri, Jayanta

2017-01-01

Recent studies have reported that activation-induced cytidine deaminase (AID) and ten-eleven-translocation (TET) family members regulate active DNA demethylation. Genetic alterations of TET2 occur in myeloid malignancies, and hematopoietic-specific loss of Tet2 induces aberrant hematopoietic stem cell (HSC) self-renewal/differentiation, implicating TET2 as a master regulator of normal and malignant hematopoiesis. Despite the functional link between AID and TET in epigenetic gene regulation, the role of AID loss in hematopoiesis and myeloid transformation remains to be investigated. Here, we show that Aid loss in mice leads to expansion of myeloid cells and reduced erythroid progenitors resulting in anemia, with dysregulated expression of Cebpa and Gata1, myeloid/erythroid lineage-specific transcription factors. Consistent with data in the murine context, silencing of AID in human bone marrow cells skews differentiation toward myelomonocytic lineage. However, in contrast to Tet2 loss, Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD to induce myeloid transformation. Genome-wide transcription and differential methylation analysis uncover the critical role of Aid as a key epigenetic regulator. These results indicate that AID and TET2 share common effects on myeloid and erythroid lineage differentiation, however, their role is nonredundant in regulating HSC self-renewal and in myeloid transformation. PMID:28077417

Loss of β-catenin triggers oxidative stress and impairs hematopoietic regeneration

PubMed Central

Lento, William; Ito, Takahiro; Zhao, Chen; Harris, Jeffrey R.; Huang, Wei; Jiang, Chen; Owzar, Kouros; Piryani, Sadhna; Racioppi, Luigi; Chao, Nelson; Reya, Tannishtha

2014-01-01

Accidental or deliberate ionizing radiation exposure can be fatal due to widespread hematopoietic destruction. However, little is known about either the course of injury or the molecular pathways that regulate the subsequent regenerative response. Here we show that the Wnt signaling pathway is critically important for regeneration after radiation-induced injury. Using Wnt reporter mice, we show that radiation triggers activation of Wnt signaling in hematopoietic stem and progenitor cells. β-Catenin-deficient mice, which lack the ability to activate canonical Wnt signaling, exhibited impaired hematopoietic stem cell regeneration and bone marrow recovery after radiation. We found that, as part of the mechanism, hematopoietic stem cells lacking β-catenin fail to suppress the generation of reactive oxygen species and cannot resolve DNA double-strand breaks after radiation. Consistent with the impaired response to radiation, β-catenin-deficient mice are also unable to recover effectively after chemotherapy. Collectively, these data indicate that regenerative responses to distinct hematopoietic injuries share a genetic dependence on β-catenin and raise the possibility that modulation of Wnt signaling may be a path to improving bone marrow recovery after damage. PMID:24788518

Tif1γ regulates the TGF-β1 receptor and promotes physiological aging of hematopoietic stem cells.

PubMed

Quéré, Ronan; Saint-Paul, Laetitia; Carmignac, Virginie; Martin, Romain Z; Chrétien, Marie-Lorraine; Largeot, Anne; Hammann, Arlette; Pais de Barros, Jean-Paul; Bastie, Jean-Noël; Delva, Laurent

2014-07-22

The hematopoietic system declines with age. Myeloid-biased differentiation and increased incidence of myeloid malignancies feature aging of hematopoietic stem cells (HSCs), but the mechanisms involved remain uncertain. Here, we report that 4-mo-old mice deleted for transcription intermediary factor 1γ (Tif1γ) in HSCs developed an accelerated aging phenotype. To reinforce this result, we also show that Tif1γ is down-regulated in HSCs during aging in 20-mo-old wild-type mice. We established that Tif1γ controls TGF-β1 receptor (Tgfbr1) turnover. Compared with young HSCs, Tif1γ(-/-) and old HSCs are more sensitive to TGF-β signaling. Importantly, we identified two populations of HSCs specifically discriminated by Tgfbr1 expression level and provided evidence of the capture of myeloid-biased (Tgfbr1(hi)) and myeloid-lymphoid-balanced (Tgfbr1(lo)) HSCs. In conclusion, our data provide a new paradigm for Tif1γ in regulating the balance between lymphoid- and myeloid-derived HSCs through TGF-β signaling, leading to HSC aging.

Vitamin A-Retinoic Acid Signaling Regulates Hematopoietic Stem Cell Dormancy.

PubMed

Cabezas-Wallscheid, Nina; Buettner, Florian; Sommerkamp, Pia; Klimmeck, Daniel; Ladel, Luisa; Thalheimer, Frederic B; Pastor-Flores, Daniel; Roma, Leticia P; Renders, Simon; Zeisberger, Petra; Przybylla, Adriana; Schönberger, Katharina; Scognamiglio, Roberta; Altamura, Sandro; Florian, Carolina M; Fawaz, Malak; Vonficht, Dominik; Tesio, Melania; Collier, Paul; Pavlinic, Dinko; Geiger, Hartmut; Schroeder, Timm; Benes, Vladimir; Dick, Tobias P; Rieger, Michael A; Stegle, Oliver; Trumpp, Andreas

2017-05-18

Dormant hematopoietic stem cells (dHSCs) are atop the hematopoietic hierarchy. The molecular identity of dHSCs and the mechanisms regulating their maintenance or exit from dormancy remain uncertain. Here, we use single-cell RNA sequencing (RNA-seq) analysis to show that the transition from dormancy toward cell-cycle entry is a continuous developmental path associated with upregulation of biosynthetic processes rather than a stepwise progression. In addition, low Myc levels and high expression of a retinoic acid program are characteristic for dHSCs. To follow the behavior of dHSCs in situ, a Gprc5c-controlled reporter mouse was established. Treatment with all-trans retinoic acid antagonizes stress-induced activation of dHSCs by restricting protein translation and levels of reactive oxygen species (ROS) and Myc. Mice maintained on a vitamin A-free diet lose HSCs and show a disrupted re-entry into dormancy after exposure to inflammatory stress stimuli. Our results highlight the impact of dietary vitamin A on the regulation of cell-cycle-mediated stem cell plasticity. VIDEO ABSTRACT. Copyright © 2017. Published by Elsevier Inc.

Asymmetric segregation and self-renewal of hematopoietic stem and progenitor cells with endocytic Ap2a2.

PubMed

Ting, Stephen B; Deneault, Eric; Hope, Kristin; Cellot, Sonia; Chagraoui, Jalila; Mayotte, Nadine; Dorn, Jonas F; Laverdure, Jean-Philippe; Harvey, Michael; Hawkins, Edwin D; Russell, Sarah M; Maddox, Paul S; Iscove, Norman N; Sauvageau, Guy

2012-03-15

The stem cell-intrinsic model of self-renewal via asymmetric cell division (ACD) posits that fate determinants be partitioned unequally between daughter cells to either activate or suppress the stemness state. ACD is a purported mechanism by which hematopoietic stem cells (HSCs) self-renew, but definitive evidence for this cellular process remains open to conjecture. To address this issue, we chose 73 candidate genes that function within the cell polarity network to identify potential determinants that may concomitantly alter HSC fate while also exhibiting asymmetric segregation at cell division. Initial gene-expression profiles of polarity candidates showed high and differential expression in both HSCs and leukemia stem cells. Altered HSC fate was assessed by our established in vitro to in vivo screen on a subcohort of candidate polarity genes, which revealed 6 novel positive regulators of HSC function: Ap2a2, Gpsm2, Tmod1, Kif3a, Racgap1, and Ccnb1. Interestingly, live-cell videomicroscopy of the endocytic protein AP2A2 shows instances of asymmetric segregation during HSC/progenitor cell cytokinesis. These results contribute further evidence that ACD is functional in HSC self-renewal, suggest a role for Ap2a2 in HSC activity, and provide a unique opportunity to prospectively analyze progeny from HSC asymmetric divisions.

Early osteoinductive human bone marrow mesenchymal stromal/stem cells support an enhanced hematopoietic cell expansion with altered chemotaxis- and adhesion-related gene expression profiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugino, Noriko; Department of Transfusion Medicine and Cell Therapy, Kyoto University Hospital, Kyoto 606-8507; Miura, Yasuo, E-mail: ym58f5@kuhp.kyoto-u.ac.jp

Bone marrow (BM) microenvironment has a crucial role in supporting hematopoiesis. Here, by using a microarray analysis, we demonstrate that human BM mesenchymal stromal/stem cells (MSCs) in an early osteoinductive stage (e-MSCs) are characterized by unique hematopoiesis-associated gene expression with an enhanced hematopoiesis-supportive ability. In comparison to BM-MSCs without osteoinductive treatment, gene expression in e-MSCs was significantly altered in terms of their cell adhesion- and chemotaxis-related profiles, as identified with Gene Ontology and Gene Set Enrichment Analysis. Noteworthy, expression of the hematopoiesis-associated molecules CXCL12 and vascular cell adhesion molecule 1 was remarkably decreased in e-MSCs. e-MSCs supported an enhanced expansionmore » of CD34{sup +} hematopoietic stem and progenitor cells, and generation of myeloid lineage cells in vitro. In addition, short-term osteoinductive treatment favored in vivo hematopoietic recovery in lethally irradiated mice that underwent BM transplantation. e-MSCs exhibited the absence of decreased stemness-associated gene expression, increased osteogenesis-associated gene expression, and apparent mineralization, thus maintaining the ability to differentiate into adipogenic cells. Our findings demonstrate the unique biological characteristics of e-MSCs as hematopoiesis-regulatory stromal cells at differentiation stage between MSCs and osteoprogenitor cells and have significant implications in developing new strategy for using pharmacological osteoinductive treatment to support hematopoiesis in hematopoietic stem and progenitor cell transplantation. - Highlights: • Human BM-MSCs in an early osteoinductive stage (e-MSCs) support hematopoiesis. • Adhesion- and chemotaxis-associated gene signatures are altered in e-MSCs. • Expression of CXCL12 and VCAM1 is remarkably decreased in e-MSCs. • e-MSCs are at differentiation stage between MSCs and osteoprogenitor cells. • Osteoinductive treatment favors hematopoietic recovery after BMT in mice.« less

Multiple myeloma-related deregulation of bone marrow-derived CD34(+) hematopoietic stem and progenitor cells.

PubMed

Bruns, Ingmar; Cadeddu, Ron-Patrick; Brueckmann, Ines; Fröbel, Julia; Geyh, Stefanie; Büst, Sebastian; Fischer, Johannes C; Roels, Frederik; Wilk, Christian Matthias; Schildberg, Frank A; Hünerlitürkoglu, Ali-Nuri; Zilkens, Christoph; Jäger, Marcus; Steidl, Ulrich; Zohren, Fabian; Fenk, Roland; Kobbe, Guido; Brors, Benedict; Czibere, Akos; Schroeder, Thomas; Trumpp, Andreas; Haas, Rainer

2012-09-27

Multiple myeloma (MM) is a clonal plasma cell disorder frequently accompanied by hematopoietic impairment. We show that hematopoietic stem and progenitor cells (HSPCs), in particular megakaryocyte-erythrocyte progenitors, are diminished in the BM of MM patients. Genomic profiling of HSPC subsets revealed deregulations of signaling cascades, most notably TGFβ signaling, and pathways involved in cytoskeletal organization, migration, adhesion, and cell-cycle regulation in the patients. Functionally, proliferation, colony formation, and long-term self-renewal were impaired as a consequence of activated TGFβ signaling. In accordance, TGFβ levels in the BM extracellular fluid were elevated and mesenchymal stromal cells (MSCs) had a reduced capacity to support long-term hematopoiesis of HSPCs that completely recovered on blockade of TGFβ signaling. Furthermore, we found defective actin assembly and down-regulation of the adhesion receptor CD44 in MM HSPCs functionally reflected by impaired migration and adhesion. Still, transplantation into myeloma-free NOG mice revealed even enhanced engraftment and normal differentiation capacities of MM HSPCs, which underlines that functional impairment of HSPCs depends on MM-related microenvironmental cues and is reversible. Taken together, these data implicate that hematopoietic suppression in MM emerges from the HSPCs as a result of MM-related microenvironmental alterations.

Distinct Roles for Matrix Metalloproteinases 2 and 9 in Embryonic Hematopoietic Stem Cell Emergence, Migration, and Niche Colonization.

PubMed

Theodore, Lindsay N; Hagedorn, Elliott J; Cortes, Mauricio; Natsuhara, Kelsey; Liu, Sarah Y; Perlin, Julie R; Yang, Song; Daily, Madeleine L; Zon, Leonard I; North, Trista E

2017-05-09

Hematopoietic stem/progenitor cells (HSPCs) are formed during ontogeny from hemogenic endothelium in the ventral wall of the dorsal aorta (VDA). Critically, the cellular mechanism(s) allowing HSPC egress and migration to secondary niches are incompletely understood. Matrix metalloproteinases (MMPs) are inflammation-responsive proteins that regulate extracellular matrix (ECM) remodeling, cellular interactions, and signaling. Here, inhibition of vascular-associated Mmp2 function caused accumulation of fibronectin-rich ECM, retention of runx1/cmyb + HSPCs in the VDA, and delayed caudal hematopoietic tissue (CHT) colonization; these defects were absent in fibronectin mutants, indicating that Mmp2 facilitates endothelial-to-hematopoietic transition via ECM remodeling. In contrast, Mmp9 was dispensable for HSPC budding, being instead required for proper colonization of secondary niches. Significantly, these migration defects were mimicked by overexpression and blocked by knockdown of C-X-C motif chemokine-12 (cxcl12), suggesting that Mmp9 controls CHT homeostasis through chemokine regulation. Our findings indicate Mmp2 and Mmp9 play distinct but complementary roles in developmental HSPC production and migration. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Determining Physical Mechanisms of Gene Expression Regulation from Single Cell Gene Expression Data.

PubMed

Ezer, Daphne; Moignard, Victoria; Göttgens, Berthold; Adryan, Boris

2016-08-01

Many genes are expressed in bursts, which can contribute to cell-to-cell heterogeneity. It is now possible to measure this heterogeneity with high throughput single cell gene expression assays (single cell qPCR and RNA-seq). These experimental approaches generate gene expression distributions which can be used to estimate the kinetic parameters of gene expression bursting, namely the rate that genes turn on, the rate that genes turn off, and the rate of transcription. We construct a complete pipeline for the analysis of single cell qPCR data that uses the mathematics behind bursty expression to develop more accurate and robust algorithms for analyzing the origin of heterogeneity in experimental samples, specifically an algorithm for clustering cells by their bursting behavior (Simulated Annealing for Bursty Expression Clustering, SABEC) and a statistical tool for comparing the kinetic parameters of bursty expression across populations of cells (Estimation of Parameter changes in Kinetics, EPiK). We applied these methods to hematopoiesis, including a new single cell dataset in which transcription factors (TFs) involved in the earliest branchpoint of blood differentiation were individually up- and down-regulated. We could identify two unique sub-populations within a seemingly homogenous group of hematopoietic stem cells. In addition, we could predict regulatory mechanisms controlling the expression levels of eighteen key hematopoietic transcription factors throughout differentiation. Detailed information about gene regulatory mechanisms can therefore be obtained simply from high throughput single cell gene expression data, which should be widely applicable given the rapid expansion of single cell genomics.

Hematopoietic recovery of acute radiation syndrome by human superoxide dismutase-expressing umbilical cord mesenchymal stromal cells.

PubMed

Gan, Jingyi; Meng, Fanwei; Zhou, Xin; Li, Chan; He, Yixin; Zeng, Xiaoping; Jiang, Xingen; Liu, Jia; Zeng, Guifang; Tang, Yunxia; Liu, Muyun; Mrsny, Randall J; Hu, Xiang; Hu, Jifan; Li, Tao

2015-04-01

Acute radiation syndrome (ARS) leads to pancytopenia and multi-organ failure. Transplantation of hematopoietic stem cells provides a curative option for radiation-induced aplasia, but this therapy is limited by donor availability. We examined an alternative therapeutic approach to ARS with the use of human extracellular superoxide dismutase (ECSOD)-modified umbilical cord mesenchymal stromal cells (UCMSCs). This treatment combines the unique regenerative role of UCMSCs with the anti-oxidative activity of ECSOD. We demonstrated that systemically administered ECSOD-UCMSCs are able to protect mice from sub-lethal doses of radiation and improve survival by promoting multilineage hematopoietic recovery. The therapeutic effect of this treatment is related to the decrease in radiation-induced O(2)(-) and apoptosis. Our data highlight the clinical potential of this two-pronged approach to the treatment of ARS, thereby serving as a rapid and effective first-line strategy to combat the hematopoietic failure resulting from a radiation accident, nuclear terrorism and other radiologic emergencies. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Graft-versus-host disease causes failure of donor hematopoiesis and lymphopoiesis in interferon-gamma receptor-deficient hosts.

PubMed

Delisle, Jean-Sébastien; Gaboury, Louis; Bélanger, Marie-Pier; Tassé, Eliane; Yagita, Hideo; Perreault, Claude

2008-09-01

The immunopathologic condition known as graft-versus-host disease (GVHD) results from a type I T-cell process. However, a prototypical type I cytokine, interferon-gamma (IFN-gamma), can protect against several manifestations of GVHD in recipients of major histocompatibility complex (MHC)-mismatched hematopoietic cells. We transplanted hematopoietic cells from C3H.SW donors in wild-type (wt) and IFN-gamma-receptor-deficient (IFN-gammaRKO) MHC-matched C57BL/6 recipients. In IFN-gammaRKO recipients, host cells were unresponsive to IFN-gamma, whereas wt donor cells were exposed to exceptionally high levels of IFN-gamma. From an IFN-gamma perspective, we could therefore evaluate the impact of a loss-of-function on host cells and gain-of-function on donor cells. We found that lack of IFN-gammaR prevented up-regulation of MHC proteins on host cells but did not mitigate damage to most target organs. Two salient phenotypes in IFN-gammaRKO recipients involved donor cells: lymphoid hypoplasia and hematopoietic failure. Lymphopenia was due to FasL-induced apoptosis and decreased cell proliferation. Bone marrow aplasia resulted from a decreased proliferation of hematopoietic stem/progenitor cells that was associated with down-regulation of 2 genes negatively regulated by IFN-gamma: Ccnd1 and Myc. We conclude that IFN-gamma produced by alloreactive T cells may entail a severe graft-versus-graft reaction and could be responsible for cytopenias that are frequently observed in subjects with GVHD.

LTβR expression on hematopoietic cells regulates acute inflammation and influences maturation of myeloid subpopulations.

PubMed

Wege, Anja K; Huber, Barbara; Wimmer, Nadin; Männel, Daniela N; Hehlgans, Thomas

2014-07-01

Lymphotoxin beta-receptor (LTβR) is involved in the formation and maintenance of secondary lymphoid structures, as well as in the regulation of inflammatory responses. Because LTβR lymphoid structure formation continues to develop in infants, we compared two different chimera models: one using adult mice and the other using a transplantation model of neonatal mice. To elucidate the function of LTβR on lymphoid and non-lymphoid cells, we generated bone marrow chimeras on the wild type C57Bl/6 and the LTβR-deficient (LTβR(-/-)) background, and reconstituted the mice with bone marrow cells reciprocally. These chimeric mice were analyzed in the experimental model of acute dextran sulfate sodium-induced colitis. Interestingly, both models revealed not only equal reconstitution levels but also similar immunological responses: LTβR expression on stromal cells is essential for lymph node formation, whereas LTBR on hematopoietic cells is crucial for a decrease in inflammation. In addition, mice lacking LTβR on hematopoietic cells revealed (a) an increase of immature granulocytic cells in the spleen and (b) a reduced proportion of myeloid cells in peripheral blood and spleen expressing CD11b(+)Ly6C(+)Ly6G(-) (myeloid-derived suppressor cells expression profile). In conclusion, LTβR expression on hematopoietic cells seems to be involved in the down-regulation of acute inflammatory reactions paralleled by the appearance of immature myeloid cells. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Mathematical model of a gene regulatory network reconciles effects of genetic perturbations on hematopoietic stem cell emergence.

PubMed

Narula, Jatin; Williams, C J; Tiwari, Abhinav; Marks-Bluth, Jonathon; Pimanda, John E; Igoshin, Oleg A

2013-07-15

Interlinked gene regulatory networks (GRNs) are vital for the spatial and temporal control of gene expression during development. The hematopoietic transcription factors (TFs) Scl, Gata2 and Fli1 form one such densely connected GRN which acts as a master regulator of embryonic hematopoiesis. This triad has been shown to direct the specification of the hemogenic endothelium and emergence of hematopoietic stem cells (HSCs) in response to Notch1 and Bmp4-Smad signaling. Here we employ previously published data to construct a mathematical model of this GRN network and use this model to systematically investigate the network dynamical properties. Our model uses a statistical-thermodynamic framework to describe the combinatorial regulation of gene expression and reconciles, mechanistically, several previously published but unexplained results from different genetic perturbation experiments. In particular, our results demonstrate how the interactions of Runx1, an essential hematopoietic TF, with components of the Bmp4 signaling pathway allow it to affect triad activation and acts as a key regulator of HSC emergence. We also explain why heterozygous deletion of this essential TF, Runx1, speeds up the network dynamics leading to accelerated HSC emergence. Taken together our results demonstrate that the triad, a master-level controller of definitive hematopoiesis, is an irreversible bistable switch whose dynamical properties are modulated by Runx1 and components of the Bmp4 signaling pathway. Copyright © 2013 Elsevier Inc. All rights reserved.

Chromosome Instability Underlies Hematopoietic Stem Cell Dysfunction and Lymphoid Neoplasia Associated with Impaired Fbw7-Mediated Cyclin E Regulation

PubMed Central

Siu, Ka Tat; Xu, Yanfei; Swartz, Kelsey L.; Bhattacharyya, Mitra; Gurbuxani, Sandeep; Hua, Youjia

2014-01-01

The Fbw7 ubiquitin ligase critically regulates hematopoietic stem cell (HSC) function, though the precise contribution of individual substrate ubiquitination pathways to HSC homeostasis is unknown. In the work reported here, we used a mouse model in which we introduced two knock-in mutations (T74A and T393A [changes of T to A at positions 74 and 393]) to disrupt Fbw7-dependent regulation of cyclin E, its prototypic substrate, and to examine the consequences of cyclin E dysregulation for HSC function. Serial transplantation revealed that cyclin ET74A T393A HSCs self-renewed normally; however, we identified defects in their multilineage reconstituting capacity. By inducing hematologic stress, we exposed an impaired self-renewal phenotype in cyclin E knock-in HSCs that was associated with defective cell cycle exit and the emergence of chromosome instability (CIN). Importantly, p53 deletion induced both defects in self-renewal and multilineage reconstitution in cyclin E knock-in HSCs with serial transplantation and CIN in hematopoietic stem and progenitor cells. Moreover, CIN was a feature of fatal T-cell malignancies that ultimately developed in recipients of cyclin ET74A T393A; p53-null HSCs. Together, our findings demonstrate the importance of Fbw7-dependent cyclin E control to the hematopoietic system and highlight CIN as a characteristic feature of HSC dysfunction and malignancy induced by deregulated cyclin E. PMID:24958101

Fanconi anemia genes are highly expressed in primitive CD34+ hematopoietic cells

PubMed Central

Aubé, Michel; Lafrance, Matthieu; Brodeur, Isabelle; Delisle, Marie-Chantal; Carreau, Madeleine

2003-01-01

Background Fanconi anemia (FA) is a complex recessive genetic disease characterized by progressive bone marrow failure (BM) and a predisposition to cancer. We have previously shown using the Fancc mouse model that the progressive BM failure results from a hematopoietic stem cell defect suggesting that function of the FA genes may reside in primitive hematopoietic stem cells. Methods Since genes involved in stem cell differentiation and/or maintenance are usually regulated at the transcription level, we used a semiquantitative RT-PCR method to evaluate FA gene transcript levels in purified hematopoietic stem cells. Results We show that most FA genes are highly expressed in primitive CD34-positive and negative cells compared to lower levels in more differentiated cells. However, in CD34- stem cells the Fancc gene was found to be expressed at low levels while Fancg was undetectable in this population. Furthermore, Fancg expression is significantly decreased in Fancc -/- stem cells as compared to wild-type cells while the cancer susceptibility genes Brca1 and Fancd1/Brac2 are upregulated in Fancc-/- hematopoietic cells. Conclusions These results suggest that FA genes are regulated at the mRNA level, that increased Fancc expression in LTS-CD34+ cells correlates with a role at the CD34+ differentiation stage and that lack of Fancc affects the expression of other FA gene, more specifically Fancg and Fancd1/Brca2, through an unknown mechanism. PMID:12809565

Post-transcriptional regulation in hematopoiesis: RNA binding proteins take control.

PubMed

de Rooij, Laura P M H; Chan, Derek C H; Keyvani Chahi, Ava; Hope, Kristin J

2018-06-13

Normal hematopoiesis is sustained through a carefully orchestrated balance between hematopoietic stem cell (HSC) self-renewal and differentiation. The functional importance of this axis is underscored by the severity of disease phenotypes initiated by abnormal HSC function, including myelodysplastic syndromes and hematopoietic malignancies. Major advances in the understanding of transcriptional regulation of primitive hematopoietic cells have been achieved, however, the post-transcriptional regulatory layer that may impinge on their behavior remains underexplored by comparison. Key players at this level include RNA binding proteins (RBPs), which execute precise and highly coordinated control of gene expression through modulation of RNA properties that include its splicing, polyadenylation, localization, degradation or translation. With the recent identification of RBPs having essential roles in regulating proliferation and cell fate decisions in other systems, there has been an increasing appreciation of the importance of post-transcriptional control at the stem cell level. Here we discuss our current understanding of RBP-driven post-transcriptional regulation in HSC, its implications for normal, perturbed and malignant hematopoiesis, as well as the most recent technological innovations aimed at RBP-RNA network characterization at the systems level. Emerging evidence highlights RBP-driven control as an underappreciated feature of primitive hematopoiesis, the greater understanding of which has important clinical implications.

Megakaryocytes regulate hematopoietic stem cell quiescence via Cxcl4 secretion

PubMed Central

Bruns, Ingmar; Lucas, Daniel; Pinho, Sandra; Ahmed, Jalal; Lambert, Michele P.; Kunisaki, Yuya; Scheiermann, Christoph; Schiff, Lauren; Poncz, Mortimer; Bergman, Aviv; Frenette, Paul S.

2014-01-01

In the bone marrow (BM), hematopoietic stem cells (HSCs) lodge in specialized microenvironments that tightly control their proliferative state to adapt to the varying needs for replenishment of blood cells while also preventing exhaustion1. All putative niche cells suggested thus far have a non-hematopoietic origin2-8. Thus, it remains unclear how feedback from mature cells is conveyed to HSCs to adjust proliferation. Here we show that megakaryocytes (Mk) can directly regulate HSC pool size. Three-dimensional whole-mount imaging revealed that endogenous HSCs are frequently located adjacent to Mk in a non-random fashion. Selective in vivo depletion of Mk resulted in specific loss of HSC quiescence and led to a marked expansion of functional HSCs. Gene expression analyses revealed that Mk were the source of chemokine C-X-C motif ligand 4 (Cxcl4, also named platelet factor 4, Pf4) in the BM and Cxcl4 injection reduced HSC numbers via increased quiescence. By contrast, Cxcl4−/− mice exhibited increased HSC numbers and proliferation. Combined use of whole-mount imaging and computational modelling was highly suggestive of a megakaryocytic niche capable of influencing independently HSC maintenance by regulating quiescence. Thus, these results indicate that a terminally differentiated HSC progeny contributes to niche activity by directly regulating HSC behavior. PMID:25326802

MiR-17/20/93/106 promote hematopoietic cell expansion by targeting sequestosome 1–regulated pathways in mice

PubMed Central

Meenhuis, Annemarie; van Veelen, Peter A.; de Looper, Hans; van Boxtel, Nicole; van den Berge, Iris J.; Sun, Su M.; Taskesen, Erdogan; Stern, Patrick; de Ru, Arnoud H.; van Adrichem, Arjan J.; Demmers, Jeroen; Jongen-Lavrencic, Mojca; Löwenberg, Bob; Touw, Ivo P.; Sharp, Phillip A.

2011-01-01

MicroRNAs (miRNAs) are pivotal for regulation of hematopoiesis but their critical targets remain largely unknown. Here, we show that ectopic expression of miR-17, -20,-93 and -106, all AAAGUGC seed-containing miRNAs, increases proliferation, colony outgrowth and replating capacity of myeloid progenitors and results in enhanced P-ERK levels. We found that these miRNAs are endogenously and abundantly expressed in myeloid progenitors and down-regulated in mature neutrophils. Quantitative proteomics identified sequestosome 1 (SQSTM1), an ubiquitin-binding protein and regulator of autophagy-mediated protein degradation, as a major target for these miRNAs in myeloid progenitors. In addition, we found increased expression of Sqstm1 transcripts during CSF3-induced neutrophil differentiation of 32D-CSF3R cells and an inverse correlation of SQSTM1 protein levels and miR-106 expression in AML samples. ShRNA-mediated silencing of Sqstm1 phenocopied the effects of ectopic miR-17/20/93/106 expression in hematopoietic progenitors in vitro and in mice. Further, SQSTM1 binds to the ligand-activated colony-stimulating factor 3 receptor (CSF3R) mainly in the late endosomal compartment, but not in LC3 positive autophagosomes. SQSTM1 regulates CSF3R stability and ligand-induced mitogen-activated protein kinase signaling. We demonstrate that AAAGUGC seed-containing miRNAs promote cell expansion, replating capacity and signaling in hematopoietic cells by interference with SQSTM1-regulated pathways. PMID:21628417

The T-Cell Oncogene Tal2 Is a Target of PU.1 and Upregulated during Osteoclastogenesis

PubMed Central

Courtial, Nadine; Mücke, Christian; Herkt, Stefanie; Kolodziej, Stephan; Hussong, Helge; Lausen, Jörn

2013-01-01

Transcription factors play a crucial role in regulating differentiation processes during human life and are important in disease. The basic helix-loop-helix transcription factors Tal1 and Lyl1 play a major role in the regulation of gene expression in the hematopoietic system and are involved in human leukemia. Tal2, which belongs to the same family of transcription factors as Tal1 and Lyl1, is also involved in human leukaemia. However, little is known regarding the expression and regulation of Tal2 in hematopoietic cells. Here we show that Tal2 is expressed in hematopoietic cells of the myeloid lineage. Interestingly, we found that usage of the Tal2 promoter is different in human and mouse cells. Two promoters, hP1 and hP2 drive Tal2 expression in human erythroleukemia K562 cells, however in mouse RAW cells only the mP1 promoter is used. Furthermore, we found that Tal2 expression is upregulated during oesteoclastogenesis. We show that Tal2 is a direct target gene of the myeloid transcription factor PU.1, which is a key transcription factor for osteoclast gene expression. Strikingly, PU.1 binding to the P1 promoter is conserved between mouse and human, but PU.1 binding to P2 was only detected in human K562 cells. Additionally, we provide evidence that Tal2 influences the expression of the osteoclastic differentiation gene TRACP. These findings provide novel insight into the expression control of Tal2 in hematopoietic cells and reveal a function of Tal2 as a regulator of gene expression during osteoclast differentiation. PMID:24086757

TIS21/(BTG2) negatively regulates estradiol-stimulated expansion of hematopoietic stem cells by derepressing Akt phosphorylation and inhibiting mTOR signal transduction.

PubMed

Kim, Bong Cho; Ryu, Min Sook; Oh, S Paul; Lim, In Kyoung

2008-09-01

It has been known that 12-O-tetradecanoyl phorbol-13-acetate-inducible sequence 21 (TIS21), ortholog of human B-cell translocation gene 2, regulates expansions of stage-specific thymocytes and hematopoietic progenitors. In the present study, lineage-negative (Lin(-))/stem cell antigen-1-positive (Sca-1+)/c-Kit+ (LSK) cell content was significantly elevated in bone marrow (BM) of TIS21-knockout (TIS21(-/-)) female mice, suggesting 17beta-estradiol (E(2))-regulated progenitor expansion. E(2) induced DNA synthesis and cell proliferation of mouse embryonic fibroblasts (MEFs) isolated from TIS21(-/-) mice, but not wild type (WT). In contrast to WT, E(2) failed to activate protein kinase B (Akt) in the TIS21(-/-) MEFs, independent of extracellular signal-regulated kinase 1/2 (Erk1/2) activation. Despite attenuation of Akt activation, mammalian target of rapamycin (mTOR) was constitutively activated in the TIS21(-/-) MEFs. Furthermore, mitogen-activated protein kinase 1/2 inhibitor or knockdown of Erk1 could restore activation of Akt and downregulate mTOR. Immunoprecipitation showed Akt preferentially bound to phosphorylated Erk1/2 (p-Erk1/2) in TIS21(-/-) cells, but reconstitution of TIS21 inhibited their interaction. E(2)-injected TIS21(-/-) male mice also increased LSK cells in BM. Taken together, expansion of hematopoietic progenitors in TIS21(-/-) female mice might be through inhibition of Akt activation, and constitutive activation of mTOR via preferential binding of TIS21 to E(2)-induced p-Erk1/2, compared with that of Akt. Our results suggest that TIS21 plays a pivotal role in maintaining the hematopoietic stem cell compartment and hematopoiesis.

Circulating hematopoietic progenitor cells in patients affected by Chornobyl accident.

PubMed

Bilko, N M; Dyagil, I S; Russu, I Z; Bilko, D I

2016-12-01

High radiation sensitivity of stem cells and their ability to accumulate sublethal radiation damage provides the basis for investigation of hematopoietic progenitors using in vivo culture methodology. Unique samples of peripheral blood and bone marrow were derived from the patients affected by Chornobyl accident during liquidation campaign. To investigate functional activity of circulating hematopoietic progenitor cells from peripheral blood and bone marrow of cleanup workers in early and remote periods after the accident at Chornobyl nuclear power plant (CNPP). The assessment of the functional activity of circulating hematopoietic progenitor cells was performed in samples of peripheral blood and bone marrow of 46 cleanup workers, who were treated in the National Scientific Center for Radiation Medicine of the Academy of Medical Sciences of Ukraine alongside with 35 non radiated patients, who served as a control. Work was performed by culturing peripheral blood and bone marrow mononuclear cells in the original gel diffusion capsules, implanted into the peritoneal cavity of CBA mice. It was shown that hematopoietic progenitor cells could be identified in the peripheral blood of liquidators of CNPP accident. At the same time the number of functionally active progenitor cells of the bone marrow was significantly decreased and during the next 10 years after the accident, counts of circulating progenitor cells in the peripheral blood as well as functionally active hematopoietic cells in bone marrow returned to normal levels. It was shown that hematopoietic progenitor cells are detected not only in the bone marrow but also in the peripheral blood of liquidators as a consequence of radiation exposure associated with CNPP accident. This article is a part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

Chromatin remodeling and stem cell theory of relativity.

PubMed

Cerny, Jan; Quesenberry, Peter J

2004-10-01

The field of stem cell biology is currently being redefined. Stem cell (hematopoietic and non-hematopoietic) differentiation has been considered hierarchical in nature, but recent data suggest that there is no progenitor/stem cell hierarchy, but rather a reversible continuum. The stem cell (hematopoietic and non-hematopoietic) phenotype, the total differentiation capacity (hematopoietic and non-hematopoietic), gene expression as well as other stem cell functional characteristics (homing, receptor and adhesion molecule expression) vary throughout a cell-cycle transit widely. This seems to be dependent on shifting chromatin and gene expression with cell-cycle transit. The published data on DNA methylation, histone acetylation, and also RNAi, the major regulators of gene expression, conjoins very well and provides an explanation for the major issues of stem cell biology. Those features of stem cells mentioned above can be rather difficult to apprehend when a classical hierarchy biology view is applied, but they become clear and easier to understand once they are correlated with the underlining epigenetic changes. We are entering a new era of stem cell biology the era of "chromatinomics." We are one step closer to the practical use of cellular therapy for degenerative diseases.

41 CFR 101-42.1102-7 - Lead-containing paint and items bearing lead-containing paint.

Code of Federal Regulations, 2012 CFR

2012-07-01

... toxic heavy metal which, in humans, exerts its effects on the renal, hematopoietic, and nervous systems... Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS...

41 CFR 101-42.1102-7 - Lead-containing paint and items bearing lead-containing paint.

Code of Federal Regulations, 2014 CFR

2014-07-01

... toxic heavy metal which, in humans, exerts its effects on the renal, hematopoietic, and nervous systems... Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS UTILIZATION...

41 CFR 101-42.1102-7 - Lead-containing paint and items bearing lead-containing paint.

Code of Federal Regulations, 2013 CFR

2013-07-01

... toxic heavy metal which, in humans, exerts its effects on the renal, hematopoietic, and nervous systems... Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS UTILIZATION...

41 CFR 101-42.1102-7 - Lead-containing paint and items bearing lead-containing paint.

Code of Federal Regulations, 2010 CFR

2010-07-01

... toxic heavy metal which, in humans, exerts its effects on the renal, hematopoietic, and nervous systems... Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS UTILIZATION...

41 CFR 101-42.1102-7 - Lead-containing paint and items bearing lead-containing paint.

Code of Federal Regulations, 2011 CFR

2011-07-01

... toxic heavy metal which, in humans, exerts its effects on the renal, hematopoietic, and nervous systems... Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS UTILIZATION...

Cord blood-derived CD34+ hematopoietic cells with low mitochondrial mass are enriched in hematopoietic repopulating stem cell function.

PubMed

Romero-Moya, Damia; Bueno, Clara; Montes, Rosa; Navarro-Montero, Oscar; Iborra, Francisco J; López, Luis Carlos; Martin, Miguel; Menendez, Pablo

2013-07-01

The homeostasis of the hematopoietic stem/progenitor cell pool relies on a fine-tuned balance between self-renewal, differentiation and proliferation. Recent studies have proposed that mitochondria regulate these processes. Although recent work has contributed to understanding the role of mitochondria during stem cell differentiation, it remains unclear whether the mitochondrial content/function affects human hematopoietic stem versus progenitor function. We found that mitochondrial mass correlates strongly with mitochondrial membrane potential in CD34(+) hematopoietic stem/progenitor cells. We, therefore, sorted cord blood CD34(+) cells on the basis of their mitochondrial mass and analyzed the in vitro homeostasis and clonogenic potential as well as the in vivo repopulating potential of CD34(+) cells with high (CD34(+) Mito(High)) versus low (CD34(+) Mito(Low)) mitochondrial mass. The CD34(+) Mito(Low) fraction contained 6-fold more CD34(+)CD38(-) primitive cells and was enriched in hematopoietic stem cell function, as demonstrated by its significantly greater hematopoietic reconstitution potential in immuno-deficient mice. In contrast, the CD34(+) Mito(High) fraction was more enriched in hematopoietic progenitor function with higher in vitro clonogenic capacity. In vitro differentiation of CD34(+) Mito(Low) cells was significantly delayed as compared to that of CD34(+) Mito(High) cells. The eventual complete differentiation of CD34(+) Mito(Low) cells, which coincided with a robust expansion of the CD34(-) differentiated progeny, was accompanied by mitochondrial adaptation, as shown by significant increases in ATP production and expression of the mitochondrial genes ND1 and COX2. In conclusion, cord blood CD34(+) cells with low levels of mitochondrial mass are enriched in hematopoietic repopulating stem cell function whereas high levels of mitochondrial mass identify hematopoietic progenitors. A mitochondrial response underlies hematopoietic stem/progenitor cell differentiation and proliferation of lineage-committed CD34(-) cells.

Tcf7 Is an Important Regulator of the Switch of Self-Renewal and Differentiation in a Multipotential Hematopoietic Cell Line

PubMed Central

Schulz, Vincent P.; Hariharan, Manoj; Tuck, David; Lian, Jin; Du, Jiang; Shi, Minyi; Ye, Zhijia; Gerstein, Mark; Snyder, Michael P.; Weissman, Sherman

2012-01-01

A critical problem in biology is understanding how cells choose between self-renewal and differentiation. To generate a comprehensive view of the mechanisms controlling early hematopoietic precursor self-renewal and differentiation, we used systems-based approaches and murine EML multipotential hematopoietic precursor cells as a primary model. EML cells give rise to a mixture of self-renewing Lin-SCA+CD34+ cells and partially differentiated non-renewing Lin-SCA-CD34− cells in a cell autonomous fashion. We identified and validated the HMG box protein TCF7 as a regulator in this self-renewal/differentiation switch that operates in the absence of autocrine Wnt signaling. We found that Tcf7 is the most down-regulated transcription factor when CD34+ cells switch into CD34− cells, using RNA–Seq. We subsequently identified the target genes bound by TCF7, using ChIP–Seq. We show that TCF7 and RUNX1 (AML1) bind to each other's promoter regions and that TCF7 is necessary for the production of the short isoforms, but not the long isoforms of RUNX1, suggesting that TCF7 and the short isoforms of RUNX1 function coordinately in regulation. Tcf7 knock-down experiments and Gene Set Enrichment Analyses suggest that TCF7 plays a dual role in promoting the expression of genes characteristic of self-renewing CD34+ cells while repressing genes activated in partially differentiated CD34− state. Finally a network of up-regulated transcription factors of CD34+ cells was constructed. Factors that control hematopoietic stem cell (HSC) establishment and development, cell growth, and multipotency were identified. These studies in EML cells demonstrate fundamental cell-intrinsic properties of the switch between self-renewal and differentiation, and yield valuable insights for manipulating HSCs and other differentiating systems. PMID:22412390

Cytohesin 1 regulates homing and engraftment of human hematopoietic stem and progenitor cells.

PubMed

Rak, Justyna; Foster, Katie; Potrzebowska, Katarzyna; Talkhoncheh, Mehrnaz Safaee; Miharada, Natsumi; Komorowska, Karolina; Torngren, Therese; Kvist, Anders; Borg, Åke; Svensson, Lena; Bonnet, Dominique; Larsson, Jonas

2017-02-23

Adhesion is a key component of hematopoietic stem cell regulation mediating homing and retention to the niche in the bone marrow. Here, using an RNA interference screen, we identify cytohesin 1 (CYTH1) as a critical mediator of adhesive properties in primary human cord blood-derived hematopoietic stem and progenitor cells (HSPCs). Knockdown of CYTH1 disrupted adhesion of HSPCs to primary human mesenchymal stroma cells. Attachment to fibronectin and ICAM1, 2 integrin ligands, was severely impaired, and CYTH1-deficient cells showed a reduced integrin β1 activation response, suggesting that CYTH1 mediates integrin-dependent functions. Transplantation of CYTH1-knockdown cells to immunodeficient mice resulted in significantly lower long-term engraftment levels, associated with a reduced capacity of the transplanted cells to home to the bone marrow. Intravital microscopy showed that CYTH1 deficiency profoundly affects HSPC mobility and localization within the marrow space and thereby impairs proper lodgment into the niche. Thus, CYTH1 is a novel major regulator of adhesion and engraftment in human HSPCs through mechanisms that, at least in part, involve the activation of integrins. © 2017 by The American Society of Hematology.

DOCK2 regulates cell proliferation through Rac and ERK activation in B cell lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lei; Nishihara, Hiroshi, E-mail: nisihara@patho2.med.hokudai.ac.jp; Kimura, Taichi

2010-04-23

DOCK2; a member of the CDM protein family, regulates cell motility and cytokine production through the activation of Rac in mammalian hematopoietic cells and plays a pivotal role in the modulation of the immune system. Here we demonstrated the alternative function of DOCK2 in hematopoietic tumor cells, especially in terms of its association with the tumor progression. Immunostaining for DOCK2 in 20 cases of human B cell lymphoma tissue specimens including diffuse large B cell lymphoma and follicular lymphoma revealed the prominent expression of DOCK2 in all of the lymphoma cells. DOCK2-knockdown (KD) of the B cell lymphoma cell lines,more » Ramos and Raji, using the lentiviral shRNA system presented decreased cell proliferation compared to the control cells. Furthermore, the tumor formation of DOCK2-KD Ramos cell in nude mice was significantly abrogated. Western blotting analysis and pull-down assay using GST-PAK-RBD kimeric protein suggested the presence of DOCK2-Rac-ERK pathway regulating the cell proliferation of these lymphoma cells. This is the first report to clarify the prominent role of DOCK2 in hematopoietic malignancy.« less

AML1/ETO accelerates cell migration and impairs cell-to-cell adhesion and homing of hematopoietic stem/progenitor cells

PubMed Central

Saia, Marco; Termanini, Alberto; Rizzi, Nicoletta; Mazza, Massimiliano; Barbieri, Elisa; Valli, Debora; Ciana, Paolo; Gruszka, Alicja M.; Alcalay, Myriam

2016-01-01

The AML1/ETO fusion protein found in acute myeloid leukemias functions as a transcriptional regulator by recruiting co-repressor complexes to its DNA binding site. In order to extend the understanding of its role in preleukemia, we expressed AML1/ETO in a murine immortalized pluripotent hematopoietic stem/progenitor cell line, EML C1, and found that genes involved in functions such as cell-to-cell adhesion and cell motility were among the most significantly regulated as determined by RNA sequencing. In functional assays, AML1/ETO-expressing cells showed a decrease in adhesion to stromal cells, an increase of cell migration rate in vitro, and displayed an impairment in homing and engraftment in vivo upon transplantation into recipient mice. Our results suggest that AML1/ETO expression determines a more mobile and less adherent phenotype in preleukemic cells, therefore altering the interaction with the hematopoietic niche, potentially leading to the migration across the bone marrow barrier and to disease progression. PMID:27713544

Lipoprotein lipase regulates hematopoietic stem progenitor cell maintenance through DHA supply.

PubMed

Liu, Chao; Han, Tianxu; Stachura, David L; Wang, Huawei; Vaisman, Boris L; Kim, Jungsu; Klemke, Richard L; Remaley, Alan T; Rana, Tariq M; Traver, David; Miller, Yury I

2018-04-03

Lipoprotein lipase (LPL) mediates hydrolysis of triglycerides (TGs) to supply free fatty acids (FFAs) to tissues. Here, we show that LPL activity is also required for hematopoietic stem progenitor cell (HSPC) maintenance. Knockout of Lpl or its obligatory cofactor Apoc2 results in significantly reduced HSPC expansion during definitive hematopoiesis in zebrafish. A human APOC2 mimetic peptide or the human very low-density lipoprotein, which carries APOC2, rescues the phenotype in apoc2 but not in lpl mutant zebrafish. Creating parabiotic apoc2 and lpl mutant zebrafish rescues the hematopoietic defect in both. Docosahexaenoic acid (DHA) is identified as an important factor in HSPC expansion. FFA-DHA, but not TG-DHA, rescues the HSPC defects in apoc2 and lpl mutant zebrafish. Reduced blood cell counts are also observed in Apoc2 mutant mice at the time of weaning. These results indicate that LPL-mediated release of the essential fatty acid DHA regulates HSPC expansion and definitive hematopoiesis.

Hematopoietic Stem Cells in Neural-crest Derived Bone Marrow.

PubMed

Jiang, Nan; Chen, Mo; Yang, Guodong; Xiang, Lusai; He, Ling; Hei, Thomas K; Chotkowski, Gregory; Tarnow, Dennis P; Finkel, Myron; Ding, Lei; Zhou, Yanheng; Mao, Jeremy J

2016-12-21

Hematopoietic stem cells (HSCs) in the endosteum of mesoderm-derived appendicular bones have been extensively studied. Neural crest-derived bones differ from appendicular bones in developmental origin, mode of bone formation and pathological bone resorption. Whether neural crest-derived bones harbor HSCs is elusive. Here, we discovered HSC-like cells in postnatal murine mandible, and benchmarked them with donor-matched, mesoderm-derived femur/tibia HSCs, including clonogenic assay and long-term culture. Mandibular CD34 negative, LSK cells proliferated similarly to appendicular HSCs, and differentiated into all hematopoietic lineages. Mandibular HSCs showed a consistent deficiency in lymphoid differentiation, including significantly fewer CD229 + fractions, PreProB, ProB, PreB and B220 + slgM cells. Remarkably, mandibular HSCs reconstituted irradiated hematopoietic bone marrow in vivo, just as appendicular HSCs. Genomic profiling of osteoblasts from mandibular and femur/tibia bone marrow revealed deficiencies in several HSC niche regulators among mandibular osteoblasts including Cxcl12. Neural crest derived bone harbors HSCs that function similarly to appendicular HSCs but are deficient in the lymphoid lineage. Thus, lymphoid deficiency of mandibular HSCs may be accounted by putative niche regulating genes. HSCs in craniofacial bones have functional implications in homeostasis, osteoclastogenesis, immune functions, tumor metastasis and infections such as osteonecrosis of the jaw.

Hhex Regulates Hematopoietic Stem Cell Self-Renewal and Stress Hematopoiesis via Repression of Cdkn2a.

PubMed

Jackson, Jacob T; Shields, Benjamin J; Shi, Wei; Di Rago, Ladina; Metcalf, Donald; Nicola, Nicos A; McCormack, Matthew P

2017-08-01

The hematopoietically expressed homeobox transcription factor (Hhex) is important for the maturation of definitive hematopoietic progenitors and B-cells during development. We have recently shown that in adult hematopoiesis, Hhex is dispensable for maintenance of hematopoietic stem cells (HSCs) and myeloid lineages but essential for the commitment of common lymphoid progenitors (CLPs) to lymphoid lineages. Here, we show that during serial bone marrow transplantation, Hhex-deleted HSCs are progressively lost, revealing an intrinsic defect in HSC self-renewal. Moreover, Hhex-deleted mice show markedly impaired hematopoietic recovery following myeloablation, due to a failure of progenitor expansion. In vitro, Hhex-null blast colonies were incapable of replating, implying a specific requirement for Hhex in immature progenitors. Transcriptome analysis of Hhex-null Lin - Sca + Kit + cells showed that Hhex deletion leads to derepression of polycomb repressive complex 2 (PRC2) and PRC1 target genes, including the Cdkn2a locus encoding the tumor suppressors p16 Ink 4 a and p19 Arf . Indeed, loss of Cdkn2a restored the capacity of Hhex-null blast colonies to generate myeloid progenitors in vitro, as well as hematopoietic reconstitution following myeloablation in vivo. Thus, HSCs require Hhex to promote PRC2-mediated Cdkn2a repression to enable continued self-renewal and response to hematopoietic stress. Stem Cells 2017;35:1948-1957. © 2017 AlphaMed Press.

[Recent research advance on bone marrow microenvironment-mediated leukemia drug resistant mechanism].

PubMed

Fu, Bing; Ling, Yan-Juan

2011-06-01

The bone marrow microenvironment consists of bone marrow stromal cells, osteoblasts and osteoclasts which facilities the survival, differentiation and proliferation of hematopoietic cells through secreting soluble factors and extracellular matrix proteins that mediate these functions. This environment not only supports the growth of normal and malignant hematopoietic cells, but also protects them against the damage from chemotherapeutic agents through the secretion of soluble cytokines, cell adhesion, up-regulation of resistant genes and changes of cell cycle. In this review, the research advances on drug-resistance mechanisms mediated by bone marrow microenvironment are summarized briefly, including soluble factors mediating drug resistance, intercellular adhesion inducing drug resistance, up-regulation of some drug resistance genes, regulation in metabolism of leukemic cells, changes in cell cycles of tumor cells and so on.

Epigenetic and Epitranscriptomic Factors Make a Mark on Hematopoietic Stem Cell Development.

PubMed

Kasper, Dionna M; Nicoli, Stefania

2018-03-01

Blood specification is a highly dynamic process, whereby committed hemogenic endothelial cells (ECs) progressively transdifferentiate into multipotent, self-renewing hematopoietic stem cells (HSCs). Massive changes in gene expression must occur to switch cell identity, however the factors that mediate such an effect were a mystery until recently. This review summarizes the higher-order mechanisms involved in endothelial to hematopoietic reprogramming identified thus far. Accumulating evidence from mouse and zebrafish studies reveal that numerous chromatin-modifying (epigenetic) and RNA-modifying (epitranscriptomic) factors are required for the formation of HSCs from hemogenic endothelium. These genes function throughout the endothelial-hematopoietic transition, suggesting a dynamic interplay between 'epi'-machineries. Epigenetic and epitranscriptomic regulation are key mechanisms for reshaping global EC gene expression patterns to those that support HSC production. Future studies that capture modification dynamics should bring us closer to a complete understanding of how HSCs transition from hemogenic endothelium at the molecular level.

MERP1: a mammalian ependymin-related protein gene differentially expressed in hematopoietic cells.

PubMed

Gregorio-King, Claudia C; McLeod, Janet L; Collier, Fiona McL; Collier, Gregory R; Bolton, Karyn A; Van Der Meer, Gavin J; Apostolopoulos, Jim; Kirkland, Mark A

2002-03-20

We have utilized differential display polymerase chain reaction to investigate the gene expression of hematopoietic progenitor cells from adult bone marrow and umbilical cord blood. A differentially expressed gene was identified in CD34+ hematopoietic progenitor cells, with low expression in CD34- cells. We have obtained the full coding sequence of this gene which we designated human mammalian ependymin-related protein 1 (MERP1). Expression of MERP1 was found in a variety of normal human tissues, and is 4- and 10-fold higher in adult bone marrow and umbilical cord blood CD34+ cells, respectively, compared to CD34- cells. Additionally, MERP1 expression in a hematopoietic stem cell enriched population was down-regulated with proliferation and differentiation. Conceptual translation of the MERP1 open reading frame reveals significant homology to two families of glycoprotein calcium-dependant cell adhesion molecules: ependymins and protocadherins.

The cell fate determinant Scribble is required for maintenance of hematopoietic stem cell function.

PubMed

Mohr, Juliane; Dash, Banaja P; Schnoeder, Tina M; Wolleschak, Denise; Herzog, Carolin; Tubio Santamaria, Nuria; Weinert, Sönke; Godavarthy, Sonika; Zanetti, Costanza; Naumann, Michael; Hartleben, Björn; Huber, Tobias B; Krause, Daniela S; Kähne, Thilo; Bullinger, Lars; Heidel, Florian H

2018-05-01

Cell fate determinants influence self-renewal potential of hematopoietic stem cells. Scribble and Llgl1 belong to the Scribble polarity complex and reveal tumor-suppressor function in drosophila. In hematopoietic cells, genetic inactivation of Llgl1 leads to expansion of the stem cell pool and increases self-renewal capacity without conferring malignant transformation. Here we show that genetic inactivation of its putative complex partner Scribble results in functional impairment of hematopoietic stem cells (HSC) over serial transplantation and during stress. Although loss of Scribble deregulates transcriptional downstream effectors involved in stem cell proliferation, cell signaling, and cell motility, these effectors do not overlap with transcriptional targets of Llgl1. Binding partner analysis of Scribble in hematopoietic cells using affinity purification followed by mass spectometry confirms its role in cell signaling and motility but not for binding to polarity modules described in drosophila. Finally, requirement of Scribble for self-renewal capacity also affects leukemia stem cell function. Thus, Scribble is a regulator of adult HSCs, essential for maintenance of HSCs during phases of cell stress.

CXCR2 and CXCL4 regulate survival and self-renewal of hematopoietic stem/progenitor cells.

PubMed

Sinclair, Amy; Park, Laura; Shah, Mansi; Drotar, Mark; Calaminus, Simon; Hopcroft, Lisa E M; Kinstrie, Ross; Guitart, Amelie V; Dunn, Karen; Abraham, Sheela A; Sansom, Owen; Michie, Alison M; Machesky, Laura; Kranc, Kamil R; Graham, Gerard J; Pellicano, Francesca; Holyoake, Tessa L

2016-07-21

The regulation of hematopoietic stem cell (HSC) survival and self-renewal within the bone marrow (BM) niche is not well understood. We therefore investigated global transcriptomic profiling of normal human HSC/hematopoietic progenitor cells [HPCs], revealing that several chemokine ligands (CXCL1-4, CXCL6, CXCL10, CXCL11, and CXCL13) were upregulated in human quiescent CD34(+)Hoescht(-)Pyronin Y(-) and primitive CD34(+)38(-), as compared with proliferating CD34(+)Hoechst(+)Pyronin Y(+) and CD34(+)38(+) stem/progenitor cells. This suggested that chemokines might play an important role in the homeostasis of HSCs. In human CD34(+) hematopoietic cells, knockdown of CXCL4 or pharmacologic inhibition of the chemokine receptor CXCR2, significantly decreased cell viability and colony forming cell (CFC) potential. Studies on Cxcr2(-/-) mice demonstrated enhanced BM and spleen cellularity, with significantly increased numbers of HSCs, hematopoietic progenitor cell-1 (HPC-1), HPC-2, and Lin(-)Sca-1(+)c-Kit(+) subpopulations. Cxcr2(-/-) stem/progenitor cells showed reduced self-renewal capacity as measured in serial transplantation assays. Parallel studies on Cxcl4 demonstrated reduced numbers of CFC in primary and secondary assays following knockdown in murine c-Kit(+) cells, and Cxcl4(-/-) mice showed a decrease in HSC and reduced self-renewal capacity after secondary transplantation. These data demonstrate that the CXCR2 network and CXCL4 play a role in the maintenance of normal HSC/HPC cell fates, including survival and self-renewal. © 2016 by The American Society of Hematology.

CXCR2 and CXCL4 regulate survival and self-renewal of hematopoietic stem/progenitor cells

PubMed Central

Sinclair, Amy; Park, Laura; Shah, Mansi; Drotar, Mark; Calaminus, Simon; Hopcroft, Lisa E. M.; Kinstrie, Ross; Guitart, Amelie V.; Dunn, Karen; Abraham, Sheela A.; Sansom, Owen; Michie, Alison M.; Machesky, Laura; Kranc, Kamil R.; Graham, Gerard J.; Pellicano, Francesca

2016-01-01

The regulation of hematopoietic stem cell (HSC) survival and self-renewal within the bone marrow (BM) niche is not well understood. We therefore investigated global transcriptomic profiling of normal human HSC/hematopoietic progenitor cells [HPCs], revealing that several chemokine ligands (CXCL1-4, CXCL6, CXCL10, CXCL11, and CXCL13) were upregulated in human quiescent CD34+Hoescht−Pyronin Y− and primitive CD34+38−, as compared with proliferating CD34+Hoechst+Pyronin Y+ and CD34+38+ stem/progenitor cells. This suggested that chemokines might play an important role in the homeostasis of HSCs. In human CD34+ hematopoietic cells, knockdown of CXCL4 or pharmacologic inhibition of the chemokine receptor CXCR2, significantly decreased cell viability and colony forming cell (CFC) potential. Studies on Cxcr2−/− mice demonstrated enhanced BM and spleen cellularity, with significantly increased numbers of HSCs, hematopoietic progenitor cell-1 (HPC-1), HPC-2, and Lin−Sca-1+c-Kit+ subpopulations. Cxcr2−/− stem/progenitor cells showed reduced self-renewal capacity as measured in serial transplantation assays. Parallel studies on Cxcl4 demonstrated reduced numbers of CFC in primary and secondary assays following knockdown in murine c-Kit+ cells, and Cxcl4−/− mice showed a decrease in HSC and reduced self-renewal capacity after secondary transplantation. These data demonstrate that the CXCR2 network and CXCL4 play a role in the maintenance of normal HSC/HPC cell fates, including survival and self-renewal. PMID:27222476

Reduced Erg Dosage Impairs Survival of Hematopoietic Stem and Progenitor Cells.

PubMed

Xie, Ying; Koch, Mia Lee; Zhang, Xin; Hamblen, Melanie J; Godinho, Frank J; Fujiwara, Yuko; Xie, Huafeng; Klusmann, Jan-Henning; Orkin, Stuart H; Li, Zhe

2017-07-01

ERG, an ETS family transcription factor frequently overexpressed in human leukemia, has been implicated as a key regulator of hematopoietic stem cells. However, how ERG controls normal hematopoiesis, particularly at the stem and progenitor cell level, and how it contributes to leukemogenesis remain incompletely understood. Using homologous recombination, we generated an Erg knockdown allele (Erg kd ) in which Erg expression can be conditionally restored by Cre recombinase. Erg kd/kd animals die at E10.5-E11.5 due to defects in endothelial and hematopoietic cells, but can be completely rescued by Tie2-Cre-mediated restoration of Erg in these cells. In Erg kd/+ mice, ∼40% reduction in Erg dosage perturbs both fetal liver and bone marrow hematopoiesis by reducing the numbers of Lin - Sca-1 + c-Kit + (LSK) hematopoietic stem and progenitor cells (HSPCs) and megakaryocytic progenitors. By genetic mosaic analysis, we find that Erg-restored HSPCs outcompete Erg kd/+ HSPCs for contribution to adult hematopoiesis in vivo. This defect is in part due to increased apoptosis of HSPCs with reduced Erg dosage, a phenotype that becomes more drastic during 5-FU-induced stress hematopoiesis. Expression analysis reveals that reduced Erg expression leads to changes in expression of a subset of ERG target genes involved in regulating survival of HSPCs, including increased expression of a pro-apoptotic regulator Bcl2l11 (Bim) and reduced expression of Jun. Collectively, our data demonstrate that ERG controls survival of HSPCs, a property that may be used by leukemic cells. Stem Cells 2017;35:1773-1785. © 2017 AlphaMed Press.

Biology of the TAM Receptors

PubMed Central

Lemke, Greg

2013-01-01

The TAM receptors—Tyro3, Axl, and Mer—comprise a unique family of receptor tyrosine kinases, in that as a group they play no essential role in embryonic development. Instead, they function as homeostatic regulators in adult tissues and organ systems that are subject to continuous challenge and renewal throughout life. Their regulatory roles are prominent in the mature immune, reproductive, hematopoietic, vascular, and nervous systems. The TAMs and their ligands—Gas6 and Protein S—are essential for the efficient phagocytosis of apoptotic cells and membranes in these tissues; and in the immune system, they act as pleiotropic inhibitors of the innate inflammatory response to pathogens. Deficiencies in TAM signaling are thought to contribute to chronic inflammatory and autoimmune disease in humans, and aberrantly elevated TAM signaling is strongly associated with cancer progression, metastasis, and resistance to targeted therapies. PMID:24186067

Biology of the TAM receptors.

PubMed

Lemke, Greg

2013-11-01

The TAM receptors--Tyro3, Axl, and Mer--comprise a unique family of receptor tyrosine kinases, in that as a group they play no essential role in embryonic development. Instead, they function as homeostatic regulators in adult tissues and organ systems that are subject to continuous challenge and renewal throughout life. Their regulatory roles are prominent in the mature immune, reproductive, hematopoietic, vascular, and nervous systems. The TAMs and their ligands--Gas6 and Protein S--are essential for the efficient phagocytosis of apoptotic cells and membranes in these tissues; and in the immune system, they act as pleiotropic inhibitors of the innate inflammatory response to pathogens. Deficiencies in TAM signaling are thought to contribute to chronic inflammatory and autoimmune disease in humans, and aberrantly elevated TAM signaling is strongly associated with cancer progression, metastasis, and resistance to targeted therapies.

Age-related mutations associated with clonal hematopoietic expansion and malignancies.

PubMed

Xie, Mingchao; Lu, Charles; Wang, Jiayin; McLellan, Michael D; Johnson, Kimberly J; Wendl, Michael C; McMichael, Joshua F; Schmidt, Heather K; Yellapantula, Venkata; Miller, Christopher A; Ozenberger, Bradley A; Welch, John S; Link, Daniel C; Walter, Matthew J; Mardis, Elaine R; Dipersio, John F; Chen, Feng; Wilson, Richard K; Ley, Timothy J; Ding, Li

2014-12-01

Several genetic alterations characteristic of leukemia and lymphoma have been detected in the blood of individuals without apparent hematological malignancies. The Cancer Genome Atlas (TCGA) provides a unique resource for comprehensive discovery of mutations and genes in blood that may contribute to the clonal expansion of hematopoietic stem/progenitor cells. Here, we analyzed blood-derived sequence data from 2,728 individuals from TCGA and discovered 77 blood-specific mutations in cancer-associated genes, the majority being associated with advanced age. Remarkably, 83% of these mutations were from 19 leukemia and/or lymphoma-associated genes, and nine were recurrently mutated (DNMT3A, TET2, JAK2, ASXL1, TP53, GNAS, PPM1D, BCORL1 and SF3B1). We identified 14 additional mutations in a very small fraction of blood cells, possibly representing the earliest stages of clonal expansion in hematopoietic stem cells. Comparison of these findings to mutations in hematological malignancies identified several recurrently mutated genes that may be disease initiators. Our analyses show that the blood cells of more than 2% of individuals (5-6% of people older than 70 years) contain mutations that may represent premalignant events that cause clonal hematopoietic expansion.

Transcription factor-mediated reprogramming toward hematopoietic stem cells

PubMed Central

Ebina, Wataru; Rossi, Derrick J

2015-01-01

De novo generation of human hematopoietic stem cells (HSCs) from renewable cell types has been a long sought-after but elusive goal in regenerative medicine. Paralleling efforts to guide pluripotent stem cell differentiation by manipulating developmental cues, substantial progress has been made recently toward HSC generation via combinatorial transcription factor (TF)-mediated fate conversion, a paradigm established by Yamanaka's induction of pluripotency in somatic cells by mere four TFs. This review will integrate the recently reported strategies to directly convert a variety of starting cell types toward HSCs in the context of hematopoietic transcriptional regulation and discuss how these findings could be further developed toward the ultimate generation of therapeutic human HSCs. PMID:25712209

ETS transcription factor ETV2/ER71/Etsrp in hematopoietic and vascular development, injury, and regeneration.

PubMed

Zhao, Haiyong; Xu, Canxin; Lee, Tae-Jin; Liu, Fang; Choi, Kyunghee

2017-04-01

The major goal in regenerative medicine is to repair and restore injured, diseased or aged tissue function, thereby promoting general health. As such, the field of regenerative medicine has great translational potential in undertaking many of the health concerns and needs that we currently face. In particular, hematopoietic and vascular systems supply oxygen and nutrients and thus play critical roles in tissue development and tissue regeneration. Additionally, tissue vasculature serves as a tissue stem cell niche and thus contributes to tissue homeostasis. Notably, hematopoietic and vascular systems are sensitive to injury and subject to regeneration. As such, successful hematopoietic and vascular regeneration is prerequisite for efficient tissue repair and organismal survival and health. Recent studies have established that the interplay among the ETS transcription factor ETV2, vascular endothelial growth factor, and its receptor VEGFR2/FLK1 is essential for hematopoietic and vascular development. Emerging studies also support the role of these three factors and possible interplay in hematopoietic and vascular regeneration. Comprehensive understanding of the molecular mechanisms involved in the regulation and function of these three factors may lead to more effective approaches in promoting tissue repair and regeneration. Developmental Dynamics 246:318-327, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Malat1 as an evolutionarily conserved lncRNA, plays a positive role in regulating proliferation and maintaining undifferentiated status of early-stage hematopoietic cells.

PubMed

Ma, Xian-Yong; Wang, Jian-Hui; Wang, Jing-Lan; Ma, Charles X; Wang, Xiao-Chun; Liu, Feng-Song

2015-09-03

The metastasis-associated lung adenocarcinoma transcription 1 (Malat1) is a highly conserved long non-coding RNA (lncRNA) gene. Previous studies showed that Malat1 is abundantly expressed in many tissues and involves in promoting tumor growth and metastasis by modulating gene expression and target protein activities. However, little is known about the biological function and regulation mechanism of Malat1 in normal cell proliferation. In this study we conformed that Malat1 is highly conserved across vast evolutionary distances amongst 20 species of mammals in terms of sequence, and found that mouse Malat1 expresses in tissues of liver, kidney, lung, heart, testis, spleen and brain, but not in skeletal muscle. After treating erythroid myeloid lymphoid (EML) cells with All-trans Retinoic Acid (ATRA), we investigated the expression and regulation of Malat1 during hematopoietic differentiation, the results showed that ATRA significantly down regulates Malat1 expression during the differentiation of EML cells. Mouse LRH (Lin-Rhodamine(low) Hoechst(low)) cells that represent the early-stage progenitor cells show a high level of Malat1 expression, while LRB (Lin - Hoechst(Low) Rhodamine(Bright)) cells that represent the late-stage progenitor cells had no detectable expression of Malat1. Knockdown experiment showed that depletion of Malat1 inhibits the EML cell proliferation. Along with the down regulation of Malat1, the tumor suppressor gene p53 was up regulated during the differentiation. Interestingly, we found two p53 binding motifs with help of bioinformatic tools, and the following chromatin immunoprecipitation (ChIP) test conformed that p53 acts as a transcription repressor that binds to Malat1's promoter. Furthermore, we testified that p53 over expression in EML cells causes down regulation of Malat1. In summary, this study indicates Malat1 plays a critical role in maintaining the proliferation potential of early-stage hematopoietic cells. In addition to its biological function, the study also uncovers the regulation pattern of Malat1 expression mediated by p53 in hematopoietic differentiation. Our research shed a light on exploring the Malat1 biological role including therapeutic significance to inhibit the proliferation potential of malignant cells.

Notch2 blockade enhances hematopoietic stem cell mobilization and homing.

PubMed

Wang, Weihuan; Yu, Shuiliang; Myers, Jay; Wang, Yiwei; Xin, William W; Albakri, Marwah; Xin, Alison W; Li, Ming; Huang, Alex Y; Xin, Wei; Siebel, Christian W; Lazarus, Hillard M; Zhou, Lan

2017-10-01

Despite use of newer approaches, some patients being considered for autologous hematopoietic cell transplantation (HCT) may only mobilize limited numbers of hematopoietic progenitor cells (HPCs) into blood, precluding use of the procedure, or being placed at increased risk of complications due to slow hematopoietic reconstitution. Developing more efficacious HPC mobilization regimens and strategies may enhance the mobilization process and improve patient outcome. Although Notch signaling is not essential for homeostasis of adult hematopoietic stem cells (HSCs), Notch-ligand adhesive interaction maintains HSC quiescence and niche retention. Using Notch receptor blocking antibodies, we report that Notch2 blockade, but not Notch1 blockade, sensitizes hematopoietic stem cells and progenitors (HSPCs) to mobilization stimuli and leads to enhanced egress from marrow to the periphery. Notch2 blockade leads to transient myeloid progenitor expansion without affecting HSC homeostasis and self-renewal. We show that transient Notch2 blockade or Notch2-loss in mice lacking Notch2 receptor lead to decreased CXCR4 expression by HSC but increased cell cycling with CXCR4 transcription being directly regulated by the Notch transcriptional protein RBPJ. In addition, we found that Notch2-blocked or Notch2-deficient marrow HSPCs show an increased homing to the marrow, while mobilized Notch2-blocked, but not Notch2-deficient stem cells and progenitors, displayed a competitive repopulating advantage and enhanced hematopoietic reconstitution. These findings suggest that blocking Notch2 combined with the current clinical regimen may further enhance HPC mobilization and improve engraftment during HCT. Copyright© 2017 Ferrata Storti Foundation.

Direct Protein Interactions Are Responsible for Ikaros-GATA and Ikaros-Cdk9 Cooperativeness in Hematopoietic Cells

PubMed Central

Bottardi, Stefania; Mavoungou, Lionel; Bourgoin, Vincent; Mashtalir, Nazar; Affar, El Bachir

2013-01-01

Ikaros (Ik) is a critical regulator of hematopoietic gene expression. Here, we established that the Ik interactions with GATA transcription factors and cyclin-dependent kinase 9 (Cdk9), a component of the positive transcription elongation factor b (P-TEFb), are required for transcriptional activation of Ik target genes. A detailed dissection of Ik-GATA and Ik-Cdk9 protein interactions indicated that the C-terminal zinc finger domain of Ik interacts directly with the C-terminal zinc fingers of GATA1, GATA2, and GATA3, whereas the N-terminal zinc finger domain of Ik is required for interaction with the kinase and T-loop domains of Cdk9. The relevance of these interactions was demonstrated in vivo in COS-7 and primary hematopoietic cells, in which Ik facilitated Cdk9 and GATA protein recruitment to gene promoters and transcriptional activation. Moreover, the oncogenic isoform Ik6 did not efficiently interact with Cdk9 or GATA proteins in vivo and perturbed Cdk9/P-TEFb recruitment to Ik target genes, thereby affecting transcription elongation. Finally, characterization of a novel nuclear Ik isoform revealed that Ik exon 6 is dispensable for interactions with Mi2 and GATA proteins but is essential for the Cdk9 interaction. Thus, Ik is central to the Ik-GATA-Cdk9 regulatory network, which is broadly utilized for gene regulation in hematopoietic cells. PMID:23732910

Direct protein interactions are responsible for Ikaros-GATA and Ikaros-Cdk9 cooperativeness in hematopoietic cells.

PubMed

Bottardi, Stefania; Mavoungou, Lionel; Bourgoin, Vincent; Mashtalir, Nazar; Affar, El Bachir; Milot, Eric

2013-08-01

Ikaros (Ik) is a critical regulator of hematopoietic gene expression. Here, we established that the Ik interactions with GATA transcription factors and cyclin-dependent kinase 9 (Cdk9), a component of the positive transcription elongation factor b (P-TEFb), are required for transcriptional activation of Ik target genes. A detailed dissection of Ik-GATA and Ik-Cdk9 protein interactions indicated that the C-terminal zinc finger domain of Ik interacts directly with the C-terminal zinc fingers of GATA1, GATA2, and GATA3, whereas the N-terminal zinc finger domain of Ik is required for interaction with the kinase and T-loop domains of Cdk9. The relevance of these interactions was demonstrated in vivo in COS-7 and primary hematopoietic cells, in which Ik facilitated Cdk9 and GATA protein recruitment to gene promoters and transcriptional activation. Moreover, the oncogenic isoform Ik6 did not efficiently interact with Cdk9 or GATA proteins in vivo and perturbed Cdk9/P-TEFb recruitment to Ik target genes, thereby affecting transcription elongation. Finally, characterization of a novel nuclear Ik isoform revealed that Ik exon 6 is dispensable for interactions with Mi2 and GATA proteins but is essential for the Cdk9 interaction. Thus, Ik is central to the Ik-GATA-Cdk9 regulatory network, which is broadly utilized for gene regulation in hematopoietic cells.

Sphingolipid Signaling and Hematopoietic Malignancies: To the Rheostat and Beyond

PubMed Central

Loh, Kenneth C.; Baldwin, Dianna; Saba, Julie D.

2011-01-01

Sphingosine-1-phosphate (S1P) is a bioactive lipid with diverse functions including the promotion of cell survival, proliferation, and migration, as well as the regulation of angiogenesis, inflammation, immunity, vascular permeability and nuclear mechanisms that control gene transcription. S1P is derived from metabolism of ceramide, which itself has diverse and generally growth-inhibitory effects through its impact on downstream targets involved in regulation of apoptosis, senescence and cell cycle progression. Regulation of ceramide, S1P and the biochemical steps that modulate the balance and interconversion of these two lipids are major determinants of cell fate, a concept referred to as the “sphingolipid rheostat.” There is abundant evidence that the sphingolipid rheostat plays a role in the origination, progression and drug resistance patterns of hematopoietic malignancies. The pathway has also been exploited to circumvent the problem of chemotherapy resistance in leukemia and lymphoma. Given the broad effects of sphingolipids, targeting multiple steps in the metabolic pathway may provide possible therapeutic avenues. However, new observations have revealed that sphingolipid signaling effects are more complex than previously recognized, requiring a revision of the sphingolipid rheostat model. Here, we summarize recent insights regarding the sphingolipid metabolic pathway and its role in hematopoietic malignancies. PMID:21707493

RanBPM (RanBP9) regulates mouse c-Kit receptor level and is essential for normal development of bone marrow progenitor cells

PubMed Central

Singh, Satyendra; Klarmann, Kimberly D.; Coppola, Vincenzo; Keller, Jonathan R.; Tessarollo, Lino

2016-01-01

c-Kit is a tyrosine kinase receptor important for gametogenesis, hematopoiesis, melanogenesis and mast cell biology. Dysregulation of c-Kit function is oncogenic and its expression in the stem cell niche of a number of tissues has underlined its relevance for regenerative medicine and hematopoietic stem cell biology. Yet, very little is known about the mechanisms that control c-Kit protein levels. Here we show that the RanBPM/RanBP9 scaffold protein binds to c-Kit and is necessary for normal c-Kit protein expression in the mouse testis and subset lineages of the hematopoietic system. RanBPM deletion causes a reduction in c-Kit protein but not its mRNA suggesting a posttranslational mechanism. This regulation is specific to the c-Kit receptor since RanBPM reduction does not affect other membrane proteins examined. Importantly, in both mouse hematopoietic system and testis, RanBPM deficiency causes defects consistent with c-Kit loss of expression suggesting that RanBPM is an important regulator of c-Kit function. The finding that this regulatory mechanism is also present in human cells expressing endogenous RanBPM and c-Kit suggests a potential new strategy to target oncogenic c-Kit in malignancies. PMID:27835883

RanBPM (RanBP9) regulates mouse c-Kit receptor level and is essential for normal development of bone marrow progenitor cells.

PubMed

Puverel, Sandrine; Kiris, Erkan; Singh, Satyendra; Klarmann, Kimberly D; Coppola, Vincenzo; Keller, Jonathan R; Tessarollo, Lino

2016-12-20

c-Kit is a tyrosine kinase receptor important for gametogenesis, hematopoiesis, melanogenesis and mast cell biology. Dysregulation of c-Kit function is oncogenic and its expression in the stem cell niche of a number of tissues has underlined its relevance for regenerative medicine and hematopoietic stem cell biology. Yet, very little is known about the mechanisms that control c-Kit protein levels. Here we show that the RanBPM/RanBP9 scaffold protein binds to c-Kit and is necessary for normal c-Kit protein expression in the mouse testis and subset lineages of the hematopoietic system. RanBPM deletion causes a reduction in c-Kit protein but not its mRNA suggesting a posttranslational mechanism. This regulation is specific to the c-Kit receptor since RanBPM reduction does not affect other membrane proteins examined. Importantly, in both mouse hematopoietic system and testis, RanBPM deficiency causes defects consistent with c-Kit loss of expression suggesting that RanBPM is an important regulator of c-Kit function. The finding that this regulatory mechanism is also present in human cells expressing endogenous RanBPM and c-Kit suggests a potential new strategy to target oncogenic c-Kit in malignancies.

Roles of Stat3 and ERK in G-CSF signaling.

PubMed

Kamezaki, Kenjirou; Shimoda, Kazuya; Numata, Akihiko; Haro, Takashi; Kakumitsu, Haruko; Yoshie, Masumi; Yamamoto, Masahiro; Takeda, Kiyoshi; Matsuda, Tadashi; Akira, Shizuo; Ogawa, Katsuhiro; Harada, Mine

2005-02-01

G-CSF specifically stimulates the proliferation and differentiation of cells that are committed to the neutrophil-granulocyte lineage. Although Stat3 was thought to be essential for the transduction of G-CSF-induced cell proliferation and differentiation signals, mice deficient for Stat3 in hematopoietic cells show neutrocytosis and infiltration of cells into the digestive tract. The number of progenitor cells in the neutrophil lineage is not changed, and G-CSF-induced proliferation of progenitor cells and prolonged neutrophil survival were observed in Stat3-deficient mice. In hematopoietic cells from Stat3-deficient mice, trace levels of SOCS3, a negative regulator of granulopoiesis, were observed, and SOCS3 expression was not induced by G-CSF stimulation. Stat3-null bone marrow cells displayed a significant activation of extra-cellular regulated kinase 1 (ERK1)/ERK2 under basal conditions, and the activation of ERK was enhanced and sustained by G-CSF stimulation. Furthermore, the augmented proliferation of Stat3-deficient bone marrow cells in response to G-CSF was dramatically decreased by addition of a MEK1 inhibitor. These results indicate that Stat3 functions as a negative regulator of G-CSF signaling by inducing SOCS3 expression and that ERK activation is the major factor responsible for inducing the proliferation of hematopoietic cells in response to G-CSF.

The development of human mast cells. An historical reappraisal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ribatti, Domenico, E-mail: domenico.ribatti@uniba.it

2016-03-15

The understanding of mast cell (MC) differentiation is derived mainly from in vitro studies of different stages of stem and progenitor cells. The hematopoietic lineage development of human MCs is unique compared to other myeloid-derived cells. Human MCs originate from CD34{sup +}/CD117{sup +}/CD13{sup +}multipotent hematopoietic progenitors, which undergo transendothelial recruitment into peripheral tissues, where they complete differentiation. Stem cell factor (SCF) is a major chemotactic factor for MCs and their progenitors. SCF also elicits cell-cell and cell-substratum adhesion, facilitates the proliferation, and sustains the survival, differentiation, and maturation, of MCs. Because MC maturation is influenced by local microenvironmental factors, differentmore » MC phenotypes can develop in different tissues and organs. - Highlights: • Human mast cells originate from CD34/CD117/CD13 positive multipotent hematopoietic progenitors. • Stem cell factor is a major chemotactic factor for mast cells and their progenitors. • Different mast cell phenotypes can develop in different tissues and organs.« less

The PIM kinases in hematological cancers.

PubMed

Alvarado, Yesid; Giles, Francis J; Swords, Ronan T

2012-02-01

The PIM genes represent a family of proto-oncogenes that encode three different serine/threonine protein kinases (PIM1, PIM2 and PIM3) with essential roles in the regulation of signal transduction cascades, which promote cell survival, proliferation and drug resistance. PIM kinases are overexpressed in several hematopoietic tumors and support in vitro and in vivo malignant cell growth and survival, through cell cycle regulation and inhibition of apoptosis. PIM kinases do not have an identified regulatory domain, which means that these proteins are constitutively active once transcribed. They appear to be critical downstream effectors of important oncoproteins and, when overexpressed, can mediate drug resistance to available agents, such as rapamycin. Recent crystallography studies reveal that, unlike other kinases, they possess a hinge region, which creates a unique binding pocket for ATP, offering a target for an increasing number of potent small-molecule PIM kinase inhibitors. Preclinical studies in models of various hematologic cancers indicate that these novel agents show promising activity and some of them are currently being evaluated in a clinical setting. In this review, we profile the PIM kinases as targets for therapeutics in hematologic malignancies.

Sex hormone drives blood stem cell reproduction.

PubMed

Calvanese, Vincenzo; Lee, Lydia K; Mikkola, Hanna K A

2014-03-18

Stem cells ensure the maintenance of tissue homeostasis throughout life by tightly regulating their self-renewal and differentiation. In a recent study published in Nature, Nakada et al, 2014 unveil an unexpected endocrine mechanism that regulates hematopoietic stem cell (HSC) self-renewal.

The possible role of liver kinase B1 in hydroquinone-induced toxicity of murine fetal liver and bone marrow hematopoietic stem cells.

PubMed

Li, Zhen; Wang, Chunhong; Zhu, Jie; Bai, YuE; Wang, Wei; Zhou, Yanfeng; Zhang, Shaozun; Liu, Xiangxiang; Zhou, Sheng; Huang, Wenting; Bi, Yongyi; Wang, Hong

2016-07-01

Epidemiological studies suggest that the increasing incidence of childhood leukemia may be due to maternal exposure to benzene, which is a known human carcinogen; however, the mechanisms involved remain unknown. Liver Kinase B1 (LKB1) acts as a regulator of cellular energy metabolism and functions to regulate hematopoietic stem cell (HSC) homeostasis. We hypothesize that LKB1 contributes to the deregulation of fetal or bone hematopoiesis caused by the benzene metabolite hydroquinone (HQ). To evaluate this hypothesis, we compared the effects of HQ on murine fetal liver hematopoietic stem cells (FL-HSCs) and bone marrow hematopoietic stem cells (BM-HSCs). FL-HSCs and BM-HSCs were isolated and enriched by a magnetic cell sorting system and exposed to various concentrations of HQ (0, 1.25, 2.5, 5, 10, 20, and 40 μM) for 24 h. We found that the inhibition of differentiation and growth, as well as the apoptosis rate of FL-HSCs, induced by HQ were consistent with the changes in BM-HSCs. Furthermore, G1 cell cycle arrest was observed in BM-HSCs and FL-HSCs in response to HQ. Importantly, FL-HSCs were more sensitive than BM-HSCs after exposure to HQ. The highest induction of LKB1 and adenosine monophosphate-activated protein kinase (AMPK) was observed with a much lower concentration of HQ in FL-HSCs than in BM-HSCs. LKB1 may play a critical role in apoptosis and cell cycle arrest of HQ-treated HSCs. This research has developed innovative ideas concerning benzene-induced hematopoietic toxicity or embryotoxicity, which can provide a new experimental evidence for preventing childhood leukemia. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 830-841, 2016. © 2014 Wiley Periodicals, Inc.

The Chromatin Regulator Brpf1 Regulates Embryo Development and Cell Proliferation*

PubMed Central

You, Linya; Yan, Kezhi; Zou, Jinfeng; Zhao, Hong; Bertos, Nicholas R.; Park, Morag; Wang, Edwin; Yang, Xiang-Jiao

2015-01-01

With hundreds of chromatin regulators identified in mammals, an emerging issue is how they modulate biological and pathological processes. BRPF1 (bromodomain- and PHD finger-containing protein 1) is a unique chromatin regulator possessing two PHD fingers, one bromodomain and a PWWP domain for recognizing multiple histone modifications. In addition, it binds to the acetyltransferases MOZ, MORF, and HBO1 (also known as KAT6A, KAT6B, and KAT7, respectively) to promote complex formation, restrict substrate specificity, and enhance enzymatic activity. We have recently showed that ablation of the mouse Brpf1 gene causes embryonic lethality at E9.5. Here we present systematic analyses of the mutant animals and demonstrate that the ablation leads to vascular defects in the placenta, yolk sac, and embryo proper, as well as abnormal neural tube closure. At the cellular level, Brpf1 loss inhibits proliferation of embryonic fibroblasts and hematopoietic progenitors. Molecularly, the loss reduces transcription of a ribosomal protein L10 (Rpl10)-like gene and the cell cycle inhibitor p27, and increases expression of the cell-cycle inhibitor p16 and a novel protein homologous to Scp3, a synaptonemal complex protein critical for chromosome association and embryo survival. These results uncover a crucial role of Brpf1 in controlling mouse embryo development and regulating cellular and gene expression programs. PMID:25773539

[Basic understanding of the HLA system in allogeneic hematopoietic cell transplantation].

PubMed

Ichinohe, Tatsuo

2015-10-01

Human immune responses are principally characterized by the human leukocyte antigen (HLA) system, a diverse set of cell surface molecules encoded by the major histocompatibility complex gene cluster on the short arm of chromosome 6. Among various members of the HLA family, the best characterized are the classic highly polymorphic class I and class II molecules that are responsible for antigen presentation to T cells and regulation of NK cell functions. In allogeneic hematopoietic cell transplantation, sophisticated approaches to donor-recipient allele-level matching at 3 class I (HLA-A/B/C) and 3 class II (HLA-DRB1/DQB1/DPB1) loci have been proven to lower the risk of immunologic complications such as graft failure and graft-versus-host disease, and possibly to confer effective graft-versus-malignancy effects. Future areas of research include clarifying the role of relatively non-polymorphic non-classical HLA molecules (HLA-E/F/G, HLA-DM/DO) and polymorphic/non-polymorphic class I-related molecules (MICA, MICB, HFE, MR1, CD1, FcRn) in the immune regulation that follows hematopoietic cell transplantation.

Microbe-Induced Inflammatory Signals Triggering Acquired Bone Marrow Failure Syndromes.

PubMed

Espinoza, J Luis; Kotecha, Ritesh; Nakao, Shinji

2017-01-01

Acquired bone marrow failure syndromes encompass a unique set of disorders characterized by a reduction in the effective production of mature cells by the bone marrow (BM). In the majority of cases, these syndromes are the result of the immune-mediated destruction of hematopoietic stem cells or their progenitors at various stages of differentiation. Microbial infection has also been associated with hematopoietic stem cell injury and may lead to associated transient or persistent BM failure, and recent evidence has highlighted the potential impact of commensal microbes and their metabolites on hematopoiesis. We summarize the interactions between microorganisms and the host immune system and emphasize how they may impact the development of acquired BM failure.

Microbe-Induced Inflammatory Signals Triggering Acquired Bone Marrow Failure Syndromes

PubMed Central

Espinoza, J. Luis; Kotecha, Ritesh; Nakao, Shinji

2017-01-01

Acquired bone marrow failure syndromes encompass a unique set of disorders characterized by a reduction in the effective production of mature cells by the bone marrow (BM). In the majority of cases, these syndromes are the result of the immune-mediated destruction of hematopoietic stem cells or their progenitors at various stages of differentiation. Microbial infection has also been associated with hematopoietic stem cell injury and may lead to associated transient or persistent BM failure, and recent evidence has highlighted the potential impact of commensal microbes and their metabolites on hematopoiesis. We summarize the interactions between microorganisms and the host immune system and emphasize how they may impact the development of acquired BM failure. PMID:28286502

Plasticity and Maintenance of Hematopoietic Stem Cells During Development

PubMed Central

Kanji, Suman; Pompili, Vincent J.; Das, Hiranmoy

2012-01-01

Maintenance of hematopoietic stem cells (HSCs) pool depends on fine balance between self-renewal and differentiation of HSCs. HSCs normally reside within the bone marrow niche of an adult mammal. The embryonic development of HSCs is a complex process that involves the migration of developing HSCs in multiple anatomical sites. Throughout the process, developing HSCs receive internal (transcriptional program) and external (HSC niche) signals, which direct them to maintain balance between self-renewal and differentiation, also to generate a pool of HSCs. In physiological condition HSCs differentiate into all mature cell types present in the blood. However, in pathological condition they may differentiate into non-hematological cells according to the need of the body. It was shown that HSCs can transdifferentiate into cell types that do not belong to the hematopoietic system suggests a complete paradigm shift of the hierarchical hematopoietic tree. This review describes the developmental origins and regulation of HSCs focusing on developmental signals that induce the adult hematopoietic stem cell program, as these informations are very critical for manipulating conditions for expansion of HSCs in ex vivo condition. This review also states clinical application and related patents using HSC. PMID:21517745

A role for thrombopoietin in hemangioblast development.

PubMed

Perlingeiro, Rita C R; Kyba, Michael; Bodie, Susan; Daley, George Q

2003-01-01

Vascular endothelial growth factor (VEGF) and stem cell factor (SCF) act as growth factors for the hemangioblast, an embryonic progenitor of the hematopoietic and endothelial lineages. Because thrombopoietin (TPO) and its receptor, c-Mpl, regulate primitive hematopoietic populations, including bone marrow hematopoietic stem cells, we investigated whether TPO acts on the hemangioblasts that derive from differentiation of embryonic stem cells in vitro. Reverse transcriptase polymerase chain reaction analysis detected expression of c-Mpl beginning on day 3 of embryoid body differentiation when the hemangioblast first arises. In assays of the hemangioblast colony-forming cell (BL-CFC), TPO alone supported BL-CFC formation and nearly doubled the number of BL-CFC when added together with VEGF and SCF. When replated under the appropriate conditions, TPO-stimulated BL-CFC gave rise to secondary hematopoietic colonies, as well as endothelial cells, confirming their nature as hemangioblasts. Addition of a neutralizing anti-VEGF antibody did not block TPO enhancement of BL-CFC formation, suggesting that TPO acts independently of VEGF. These results establish that Mpl signaling plays a role in the earliest stages of hematopoietic development and that TPO represents a third growth factor influencing hemangioblast formation.

The SKI proto-oncogene enhances the in vivo repopulation of hematopoietic stem cells and causes myeloproliferative disease.

PubMed

Singbrant, Sofie; Wall, Meaghan; Moody, Jennifer; Karlsson, Göran; Chalk, Alistair M; Liddicoat, Brian; Russell, Megan R; Walkley, Carl R; Karlsson, Stefan

2014-04-01

The proto-oncogene SKI is highly expressed in human myeloid leukemia and also in murine hematopoietic stem cells. However, its operative relevance in these cells remains elusive. We have over-expressed SKI to define its intrinsic role in hematopoiesis and myeloid neoplasms, which resulted in a robust competitive advantage upon transplantation, a complete dominance of the stem and progenitor compartments, and a marked enhancement of myeloid differentiation at the expense of other lineages. Accordingly, enforced expression of SKI induced a gene signature associated with hematopoietic stem cells and myeloid differentiation, as well as hepatocyte growth factor signaling. Here we demonstrate that, in contrast to what has generally been assumed, the significant impact of SKI on hematopoiesis is independent of its ability to inhibit TGF-beta signaling. Instead, myeloid progenitors expressing SKI are partially dependent on functional hepatocyte growth factor signaling. Collectively our results demonstrate that SKI is an important regulator of hematopoietic stem cell activity and its overexpression leads to myeloproliferative disease.

Essential role of FBXL5-mediated cellular iron homeostasis in maintenance of hematopoietic stem cells

PubMed Central

Muto, Yoshiharu; Nishiyama, Masaaki; Nita, Akihiro; Moroishi, Toshiro; Nakayama, Keiichi I.

2017-01-01

Hematopoietic stem cells (HSCs) are maintained in a hypoxic niche to limit oxidative stress. Although iron elicits oxidative stress, the importance of iron homeostasis in HSCs has been unknown. Here we show that iron regulation by the F-box protein FBXL5 is required for HSC self-renewal. Conditional deletion of Fbxl5 in mouse HSCs results in cellular iron overload and a reduced cell number. Bone marrow transplantation reveals that FBXL5-deficient HSCs are unable to reconstitute the hematopoietic system of irradiated recipients as a result of stem cell exhaustion. Transcriptomic analysis shows abnormal activation of oxidative stress responses and the cell cycle in FBXL5-deficient mouse HSCs as well as downregulation of FBXL5 expression in HSCs of patients with myelodysplastic syndrome. Suppression of iron regulatory protein 2 (IRP2) accumulation in FBXL5-deficient mouse HSCs restores stem cell function, implicating IRP2 as a potential therapeutic target for human hematopoietic diseases associated with FBXL5 downregulation. PMID:28714470

The SKI proto-oncogene enhances the in vivo repopulation of hematopoietic stem cells and causes myeloproliferative disease

PubMed Central

Singbrant, Sofie; Wall, Meaghan; Moody, Jennifer; Karlsson, Göran; Chalk, Alistair M.; Liddicoat, Brian; Russell, Megan R.; Walkley, Carl R.; Karlsson, Stefan

2014-01-01

The proto-oncogene SKI is highly expressed in human myeloid leukemia and also in murine hematopoietic stem cells. However, its operative relevance in these cells remains elusive. We have over-expressed SKI to define its intrinsic role in hematopoiesis and myeloid neoplasms, which resulted in a robust competitive advantage upon transplantation, a complete dominance of the stem and progenitor compartments, and a marked enhancement of myeloid differentiation at the expense of other lineages. Accordingly, enforced expression of SKI induced a gene signature associated with hematopoietic stem cells and myeloid differentiation, as well as hepatocyte growth factor signaling. Here we demonstrate that, in contrast to what has generally been assumed, the significant impact of SKI on hematopoiesis is independent of its ability to inhibit TGF-beta signaling. Instead, myeloid progenitors expressing SKI are partially dependent on functional hepatocyte growth factor signaling. Collectively our results demonstrate that SKI is an important regulator of hematopoietic stem cell activity and its overexpression leads to myeloproliferative disease. PMID:24415629

Polycythemia in transgenic mice expressing the human erythropoietin gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Semenza, G.L.; Traystman, M.D.; Gearhart, J.D.

1989-04-01

Erythropoietin is a glycoprotein hormone that regulates mammalian erythropoiesis. To study the expression of the human erythropoietin gene, EPO, 4 kilobases of DNA encompassing the gene with 0.4 kilobase of 5{prime} flanking sequence and 0.7 kilobase of 3{prime} flanking sequence was microinjected into fertilized mouse eggs. Transgenic mice were generated that are polycythemic, with increased erythrocytic indices in peripheral blood, increased numbers of erythroid precursors in hematopoietic tissue, and increased serum erythropoietin levels. Transgenic homozygotes show a greater degree of polycythemia than do heterozygotes as well as striking extramedullary erythropoiesis. Human erythropoietin RNA was found not only in fetal liver,more » adult liver, and kidney but also in all other transgenic tissues analyzed. Anemia induced increased human erythropoietin RNA levels in liver but not kidney. These transgenic mice represent a unique model of polycythemia due to increased erythropoietin levels.« less

Hematopoietic stem cells are acutely sensitive to Acd shelterin gene inactivation

PubMed Central

Jones, Morgan; Osawa, Gail; Regal, Joshua A.; Weinberg, Daniel N.; Taggart, James; Kocak, Hande; Friedman, Ann; Ferguson, David O.; Keegan, Catherine E.; Maillard, Ivan

2013-01-01

The shelterin complex plays dual functions in telomere homeostasis by recruiting telomerase and preventing the activation of a DNA damage response at telomeric ends. Somatic stem cells require telomerase activity, as evidenced by progressive stem cell loss leading to bone marrow failure in hereditary dyskeratosis congenita. Recent work demonstrates that dyskeratosis congenita can also arise from mutations in specific shelterin genes, although little is known about shelterin functions in somatic stem cells. We found that mouse hematopoietic stem cells (HSCs) are acutely sensitive to inactivation of the shelterin gene Acd, encoding TPP1. Homozygosity for a hypomorphic acd allele preserved the emergence and expansion of fetal HSCs but led to profoundly defective function in transplantation assays. Upon complete Acd inactivation, HSCs expressed p53 target genes, underwent cell cycle arrest, and were severely depleted within days, leading to hematopoietic failure. TPP1 loss induced increased telomeric fusion events in bone marrow progenitors. However, unlike in epidermal stem cells, p53 deficiency did not rescue TPP1-deficient HSCs, indicating that shelterin dysfunction has unique effects in different stem cell populations. Because the consequences of telomere shortening are progressive and unsynchronized, acute loss of shelterin function represents an attractive alternative for studying telomere crisis in hematopoietic progenitors. PMID:24316971

Purified hematopoietic stem cell engraftment of rare niches corrects severe lymphoid deficiencies without host conditioning

PubMed Central

Bhattacharya, Deepta; Rossi, Derrick J.; Bryder, David; Weissman, Irving L.

2006-01-01

In the absence of irradiation or other cytoreductive conditioning, endogenous hematopoietic stem cells (HSCs) are thought to fill the unique niches within the bone marrow that allow maintenance of full hematopoietic potential and thus prevent productive engraftment of transplanted donor HSCs. By transplantation of purified exogenous HSCs into unconditioned congenic histocompatible strains of mice, we show that ∼0.1–1.0% of these HSC niches are available for engraftment at any given point and find no evidence that endogenous HSCs can be displaced from the niches they occupy. We demonstrate that productive engraftment of HSCs within these empty niches is inhibited by host CD4+ T cells that recognize very subtle minor histocompatibility differences. Strikingly, transplantation of purified HSCs into a panel of severe combined immunodeficient (SCID) mice leads to a rapid and complete rescue of lymphoid deficiencies through engraftment of these very rare niches and expansion of donor lymphoid progenitors. We further demonstrate that transient antibody-mediated depletion of CD4+ T cells allows short-term HSC engraftment and regeneration of B cells in a mouse model of B(-) non-SCID. These experiments provide a general mechanism by which transplanted HSCs can correct hematopoietic deficiencies without any host conditioning or with only highly specific and transient lymphoablation. PMID:16380511

Essential Neuroscience in Immunology.

PubMed

Chavan, Sangeeta S; Tracey, Kevin J

2017-05-01

The field of immunology is principally focused on the molecular mechanisms by which hematopoietic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with the identification of several other reflexes regulating discrete immune functions. As outlined in this review, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first-in-class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoietic and neural responses to infection and injury. Copyright © 2017 by The American Association of Immunologists, Inc.

[Research Progress on Metabolic Regulatory Mechanisms of Hematopoietic Stem Cells -Review].

PubMed

Zhang, Ya-Wen; Cheng, Hui; Cheng, Tao

2018-06-01

Hematopoietic stem cells (HSC) are a class of stem cells with self-renewal and multipotent differentiation into a variety of blood cells and are most thoroughly studied, maturely applied in the clinic adult stem cell. Function of HSC is closely associated with metabolic regulation. The metabolic state mainly maintains HSC living in hypoxic bone marrow microenvironment depending on glycolysis for energy metabolism, and keeping low reactive oxygen species (ROS) level. Proteins like Hif-1, FoxO3, ATM, PTPMT1 protect HSC from ROS injury, maintaining HSC in hypoxic state. In addition, glucose metabolism-related enzymes, glutamine, fatty acid oxidation, purine and amino acid metabolism also play important roles in metabolic regulation of HSC. In this review the research progress on metabolism regnlation mechanisms of HSC is summurized, focusing on the mechanisms releted with oxydation metabolism regulation, carbohydrate metabolism level, purine metabolism and aminoacide metabolism.

Oxidative Stress, Bone Marrow Failure, and Genome Instability in Hematopoietic Stem Cells

PubMed Central

Richardson, Christine; Yan, Shan; Vestal, C. Greer

2015-01-01

Reactive oxygen species (ROS) can be generated by defective endogenous reduction of oxygen by cellular enzymes or in the mitochondrial respiratory pathway, as well as by exogenous exposure to UV or environmental damaging agents. Regulation of intracellular ROS levels is critical since increases above normal concentrations lead to oxidative stress and DNA damage. A growing body of evidence indicates that the inability to regulate high levels of ROS leading to alteration of cellular homeostasis or defective repair of ROS-induced damage lies at the root of diseases characterized by both neurodegeneration and bone marrow failure as well as cancer. That these diseases may be reflective of the dynamic ability of cells to respond to ROS through developmental stages and aging lies in the similarities between phenotypes at the cellular level. This review summarizes work linking the ability to regulate intracellular ROS to the hematopoietic stem cell phenotype, aging, and disease. PMID:25622253

Mapping gene expression patterns during myeloid differentiation using the EML hematopoietic progenitor cell line.

PubMed

Du, Yang; Campbell, Janee L; Nalbant, Demet; Youn, Hyewon; Bass, Ann C Hughes; Cobos, Everardo; Tsai, Schickwann; Keller, Jonathan R; Williams, Simon C

2002-07-01

The detailed examination of the molecular events that control the early stages of myeloid differentiation has been hampered by the relative scarcity of hematopoietic stem cells and the lack of suitable cell line models. In this study, we examined the expression of several myeloid and nonmyeloid genes in the murine EML hematopoietic stem cell line. Expression patterns for 19 different genes were examined by Northern blotting and RT-PCR in RNA samples from EML, a variety of other immortalized cell lines, and purified murine hematopoietic stem cells. Representational difference analysis (RDA) was performed to identify differentially expressed genes in EML. Expression patterns of genes encoding transcription factors (four members of the C/EBP family, GATA-1, GATA-2, PU.1, CBFbeta, SCL, and c-myb) in EML were examined and were consistent with the proposed functions of these proteins in hematopoietic differentiation. Expression levels of three markers of terminal myeloid differentiation (neutrophil elastase, proteinase 3, and Mac-1) were highest in EML cells at the later stages of differentiation. In a search for genes that were differentially expressed in EML cells during myeloid differentiation, six cDNAs were isolated. These included three known genes (lysozyme, histidine decarboxylase, and tryptophan hydroxylase) and three novel genes. Expression patterns of known genes in differentiating EML cells accurately reflected their expected expression patterns based on previous studies. The identification of three novel genes, two of which encode proteins that may act as regulators of hematopoietic differentiation, suggests that EML is a useful model system for the molecular analysis of hematopoietic differentiation.

Harnessing endogenous miR-181a to segregate transgenic antigen receptor expression in developing versus post-thymic T cells in murine hematopoietic chimeras.

PubMed

Papapetrou, Eirini P; Kovalovsky, Damian; Beloeil, Laurent; Sant'angelo, Derek; Sadelain, Michel

2009-01-01

MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression by targeting complementary sequences, referred to as miRNA recognition elements (MREs), typically located in the 3' untranslated region of mRNAs. miR-181a is highly expressed in developing thymocytes and markedly downregulated in post-thymic T cells. We investigated whether endogenous miR-181a can be harnessed to segregate expression of chimeric antigen receptors (CARs) and TCRs between developing and mature T cells. Lentiviral-encoded antigen receptors were tagged with a miR-181a-specific MRE and transduced into mouse BM cells that were used to generate hematopoietic chimeras. Expression of a CAR specific for human CD19 (hCD19) was selectively suppressed in late double-negative and double-positive thymocytes, coinciding with the peak in endogenous miR-181a expression. Receptor expression was fully restored in post-thymic resting and activated T cells, affording protection against a subsequent challenge with hCD19+ tumors. Hematopoietic mouse chimeras engrafted with a conalbumin-specific TCR prone to thymic clonal deletion acquired peptide-specific T cell responsiveness only when the vector-encoded TCR transcript was similarly engineered to be subject to regulation by miR-181a. These results demonstrate the potential of miRNA-regulated transgene expression in stem cell-based therapies, including cancer immunotherapy.

Histone acetyltransferase activity of MOF is required for adult but not early fetal hematopoiesis in mice

PubMed Central

Valerio, Daria G.; Xu, Haiming; Eisold, Meghan E.; Woolthuis, Carolien M.; Pandita, Tej K.

2017-01-01

K(lysine) acetyltransferase 8 (KAT8, also known as MOF) mediates the acetylation of histone H4 at lysine 16 (H4K16ac) and is crucial for murine embryogenesis. Lysine acetyltransferases have been shown to regulate various stages of normal hematopoiesis. However, the function of MOF in hematopoietic stem cell (HSC) development has not yet been elucidated. We set out to study the role of MOF in general hematopoiesis by using a Vav1-cre–induced conditional murine Mof knockout system and found that MOF is critical for hematopoietic cell maintenance and HSC engraftment capacity in adult hematopoiesis. Rescue experiments with a MOF histone acetyltransferase domain mutant illustrated the requirement for MOF acetyltransferase activity in the clonogenic capacity of HSCs and progenitors. In stark contrast, fetal steady-state hematopoiesis at embryonic day (E) 14.5 was not affected by homozygous Mof deletion despite dramatic loss of global H4K16ac. Hematopoietic defects start manifesting in late gestation at E17.5. The discovery that MOF and its H4K16ac activity are required for adult but not early and midgestational hematopoiesis supports the notion that multiple chromatin regulators may be crucial for hematopoiesis at varying stages of development. MOF is therefore a developmental-stage–specific chromatin regulator found to be essential for adult but not early fetal hematopoiesis. PMID:27827827

CBL family E3 ubiquitin ligases control JAK2 ubiquitination and stability in hematopoietic stem cells and myeloid malignancies

PubMed Central

Lv, Kaosheng; Jiang, Jing; Donaghy, Ryan; Riling, Christopher R.; Cheng, Ying; Chandra, Vemika; Rozenova, Krasimira; An, Wei; Mohapatra, Bhopal C.; Goetz, Benjamin T.; Pillai, Vinodh; Han, Xu; Todd, Emily A.; Jeschke, Grace R.; Langdon, Wallace Y.; Kumar, Suresh; Hexner, Elizabeth O.

2017-01-01

Janus kinase 2 (JAK2) is a central kinase in hematopoietic stem/progenitor cells (HSPCs), and its uncontrolled activation is a prominent oncogenic driver of hematopoietic neoplasms. However, molecular mechanisms underlying the regulation of JAK2 have remained elusive. Here we report that the Casitas B-cell lymphoma (CBL) family E3 ubiquitin ligases down-regulate JAK2 stability and signaling via the adaptor protein LNK/SH2B3. We demonstrated that depletion of CBL/CBL-B or LNK abrogated JAK2 ubiquitination, extended JAK2 half-life, and enhanced JAK2 signaling and cell growth in human cell lines as well as primary murine HSPCs. Built on these findings, we showed that JAK inhibitor (JAKi) significantly reduced aberrant HSPCs and mitigated leukemia development in a mouse model of aggressive myeloid leukemia driven by loss of Cbl and Cbl-b. Importantly, primary human CBL mutated (CBLmut) leukemias exhibited increased JAK2 protein levels and signaling and were hypersensitive to JAKi. Loss-of-function mutations in CBL E3 ubiquitin ligases are found in a wide range of myeloid malignancies, which are diseases without effective treatment options. Hence, our studies reveal a novel signaling axis that regulates JAK2 in normal and malignant HSPCs and suggest new therapeutic strategies for treating CBLmut myeloid malignancies. PMID:28611190

Regulation of long-term repopulating hematopoietic stem cells by EPCR/PAR1 signaling

PubMed Central

Gur-Cohen, Shiri; Kollet, Orit; Graf, Claudine; Esmon, Charles T.; Ruf, Wolfram; Lapidot, Tsvee

2016-01-01

The common developmental origin of endothelial and hematopoietic cells is manifested by coexpression of several cell surface receptors. Adult murine bone marrow (BM) long-term repopulating hematopoietic stem cells (LT-HSCs), endowed with the highest repopulation and self-renewal potential, express endothelial protein C receptor (EPCR), which is used as a marker to isolate them. EPCR/PAR1 signaling in endothelial cells has anticoagulant and anti-inflammatory roles, while thrombin/PAR1 signaling induces coagulation and inflammation. Recent studies define two new PAR1-mediated signaling cascades that regulate EPCR+ LT-HSC BM retention and egress. EPCR/PAR1 signaling facilitates LT-HSC BM repopulation, retention, survival, and chemotherapy resistance by restricting nitric oxide (NO) production, maintaining NOlow LT-HSC BM retention with increased VLA4 expression, affinity, and adhesion. Conversely, acute stress and clinical mobilization upregulate thrombin generation and activate different PAR1 signaling which overcomes BM EPCR+ LT-HSC retention, inducing their recruitment to the bloodstream. Thrombin/PAR1 signaling induces NO generation, TACE-mediated EPCR shedding, and upregulation of CXCR4 and PAR1, leading to CXCL12-mediated stem and progenitor cell mobilization. This review discusses new roles for factors traditionally viewed as coagulation related, which independently act in the BM to regulate PAR1 signaling in bone- and blood-forming progenitor cells, navigating their fate by controlling NO production. PMID:26928241

[Experimental study on aging effect of Angelica sinensis polysaccharides combined with cytarabine on human leukemia KG1alpha cell lines].

PubMed

Xu, Chun-Yan; Geng, Shan; Liu, Jun; Zhu, Jia-Hong; Zhang, Xian-Ping; Jiang, Rong; Wang, Ya-Ping

2014-04-01

The latest findings of our laboratory showed that Angelica sinensis polysaccharide (ASP) showed a definite effect in regulating the aging of hematopoietic stem cells. Leukemia is a type of malignant hematopoietic tumor in hematopoietic stem cells. There have been no relevant reports about ASP's effect in regulating the aging of leukemia cells. In this study, human acute myeloid leukemia (AML) KG1alpha cell lines in logarithmic growth phase were taken as the study object, and were divided into the ASP group, the cytarabine (Ara-C) group, the ASP + Ara-C group and the control group. The groups were respectively treated with different concentration of ASP, Ara-C and ASP + Ara-C for different periods, with the aim to study the effect of ASP combined with Ara-C in regulating the aging of human acute myeloid leukemia KG1alpha cell lines and its relevant mechanism. The results showed that ASP, Ara-C and ASP + Ara-C could obviously inhibit KG1alpha cell proliferation in vitro, block the cells in G0/G1 phase. The cells showed the aging morphological feature. The percentage of positive stained aging cells was dramatically increased, and could significantly up-regulate the expression of aging-related proteins P16 and RB, which were more obvious in the ASP + Ara-C group. In conclusion, the aging mechanism of KG1alpha cell induced by ASP and Ara-C may be related to the regulation of the expression of aging-related proteins, suggesting that the combined administration of ASP and anticancer drugs plays a better role in the treatment of leukemia .

Role of Tat-interacting protein of 110 kDa and microRNAs in the regulation of hematopoiesis.

PubMed

Liu, Ying; He, Johnny J

2016-07-01

Hematopoiesis is regulated by cellular factors including transcription factors, microRNAs, and epigenetic modifiers. Understanding how these factors regulate hematopoiesis is pivotal for manipulating them to achieve their desired potential. In this review, we will focus on HIV-1 Tat-interacting protein of 110 kDa (Tip110) and its regulation of hematopoiesis. There are several pathways in hematopoiesis that involve Tip110 regulation. Tip110 is expressed in human cord blood CD34 cells; its expression decreases when CD34 cells begin to differentiate. Tip110 is also expressed in mouse marrow hematopoietic stem cells (HSC) and hematopoietic progenitor cells (HPC). Tip110 expression increases the number, survival, and cell cycling of HPC. Tip110-mediated regulation of hematopoiesis has been linked to its reciprocal control of proto-oncogene expression. Small noncoding microRNAs (miRs) have been shown to play important roles in regulation of hematopoiesis. miR-124 specifically targets 3'-untranslated region of Tip110 and subsequently regulates Tip110 expression in HSC. Our recent findings for manipulating expression levels of Tip110 in HSC and HPC could be useful for expanding HSC and HPC and for improving engraftment of cord blood HSC/HPC.

Umbilical cord blood banking in the worldwide hematopoietic stem cell transplantation system: perspectives for Ukraine.

PubMed

Kalynychenko, T O

2017-09-01

Significant progress in the promotion of procedural technologies associated with the transplantation of hematopoietic stem cells caused a rapid increase in activity. The exchange of hematopoietic stem cells for unrelated donor transplantations is now much easier due to the relevant international professional structures and organizations established to support cooperation and standard setting, as well as rules for the functioning of both national donor registries and cord blood banks. These processes are increasing every year and are contributing to the outpacing rates of development in this area. Products within their country should be regulated by the competent government authorities. This study analyzes the work of international and national levels of support for transplantation activity in the field of unrelated hematopoietic stem cell transplantation, the standardization order of technologies, as well as data that justify the need to create a network of donated umbilical cord blood banks in Ukraine as a factor in the development of allogeneic transplantation. This will promote the accessibility of international standards for the treatment of serious diseases for Ukrainian citizens.

The Chromatin Remodeler BPTF Activates a Stemness Gene-Expression Program Essential for the Maintenance of Adult Hematopoietic Stem Cells.

PubMed

Xu, Bowen; Cai, Ling; Butler, Jason M; Chen, Dongliang; Lu, Xiongdong; Allison, David F; Lu, Rui; Rafii, Shahin; Parker, Joel S; Zheng, Deyou; Wang, Gang Greg

2018-03-13

Self-renewal and differentiation of adult stem cells are tightly regulated partly through configuration of chromatin structure by chromatin remodelers. Using knockout mice, we here demonstrate that bromodomain PHD finger transcription factor (BPTF), a component of the nucleosome remodeling factor (NURF) chromatin-remodeling complex, is essential for maintaining the population size of hematopoietic stem/progenitor cells (HSPCs), including long-term hematopoietic stem cells (HSCs). Bptf-deficient HSCs are defective in reconstituted hematopoiesis, and hematopoietic-specific knockout of Bptf caused profound defects including bone marrow failure and anemia. Genome-wide transcriptome profiling revealed that BPTF loss caused downregulation of HSC-specific gene-expression programs, which contain several master transcription factors (Meis1, Pbx1, Mn1, and Lmo2) required for HSC maintenance and self-renewal. Furthermore, we show that BPTF potentiates the chromatin accessibility of key HSC "stemness" genes. These results demonstrate an essential requirement of the chromatin remodeler BPTF and NURF for activation of "stemness" gene-expression programs and proper function of adult HSCs. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Latexin Inactivation Enhances Survival and Long-Term Engraftment of Hematopoietic Stem Cells and Expands the Entire Hematopoietic System in Mice.

PubMed

Liu, Yi; Zhang, Cuiping; Li, Zhenyu; Wang, Chi; Jia, Jianhang; Gao, Tianyan; Hildebrandt, Gerhard; Zhou, Daohong; Bondada, Subbarao; Ji, Peng; St Clair, Daret; Liu, Jinze; Zhan, Changguo; Geiger, Hartmut; Wang, Shuxia; Liang, Ying

2017-04-11

Natural genetic diversity offers an important yet largely untapped resource to decipher the molecular mechanisms regulating hematopoietic stem cell (HSC) function. Latexin (Lxn) is a negative stem cell regulatory gene identified on the basis of genetic diversity. By using an Lxn knockout mouse model, we found that Lxn inactivation in vivo led to the physiological expansion of the entire hematopoietic hierarchy. Loss of Lxn enhanced the competitive repopulation capacity and survival of HSCs in a cell-intrinsic manner. Gene profiling of Lxn-null HSCs showed altered expression of genes enriched in cell-matrix and cell-cell interactions. Thrombospondin 1 (Thbs1) was a potential downstream target with a dramatic downregulation in Lxn-null HSCs. Enforced expression of Thbs1 restored the Lxn inactivation-mediated HSC phenotypes. This study reveals that Lxn plays an important role in the maintenance of homeostatic hematopoiesis, and it may lead to development of safe and effective approaches to manipulate HSCs for clinical benefit. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Proteinase-Activated Receptor 1 (PAR1) Regulates Leukemic Stem Cell Functions

PubMed Central

Bäumer, Nicole; Krause, Annika; Köhler, Gabriele; Lettermann, Stephanie; Evers, Georg; Hascher, Antje; Bäumer, Sebastian; Berdel, Wolfgang E.

2014-01-01

External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1−/− hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1−/− leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance. PMID:24740120

Proteinase-Activated Receptor 1 (PAR1) regulates leukemic stem cell functions.

PubMed

Bäumer, Nicole; Krause, Annika; Köhler, Gabriele; Lettermann, Stephanie; Evers, Georg; Hascher, Antje; Bäumer, Sebastian; Berdel, Wolfgang E; Müller-Tidow, Carsten; Tickenbrock, Lara

2014-01-01

External signals that are mediated by specific receptors determine stem cell fate. The thrombin receptor PAR1 plays an important role in haemostasis, thrombosis and vascular biology, but also in tumor biology and angiogenesis. Its expression and function in hematopoietic stem cells is largely unknown. Here, we analyzed expression and function of PAR1 in primary hematopoietic cells and their leukemic counterparts. AML patients' blast cells expressed much lower levels of PAR1 mRNA and protein than CD34+ progenitor cells. Constitutive Par1-deficiency in adult mice did not affect engraftment or stem cell potential of hematopoietic cells. To model an AML with Par1-deficiency, we retrovirally introduced the oncogene MLL-AF9 in wild type and Par1-/- hematopoietic progenitor cells. Par1-deficiency did not alter initial leukemia development. However, the loss of Par1 enhanced leukemic stem cell function in vitro and in vivo. Re-expression of PAR1 in Par1-/- leukemic stem cells delayed leukemogenesis in vivo. These data indicate that Par1 contributes to leukemic stem cell maintenance.

Shear Stress Regulates Adhesion and Rolling of CD44+ Leukemic and Hematopoietic Progenitor Cells on Hyaluronan

PubMed Central

Christophis, Christof; Taubert, Isabel; Meseck, Georg R.; Schubert, Mario; Grunze, Michael; Ho, Anthony D.; Rosenhahn, Axel

2011-01-01

Leukemic cells and human hematopoietic progenitor cells expressing CD44 receptors have the ability to attach and roll on hyaluronan. We investigated quantitatively the adhesion behavior of leukemic cell lines and hematopoietic progenitor cells on thin films of the polysaccharides hyaluronan and alginate in a microfluidic system. An applied flow enhances the interaction between CD44-positive cells and hyaluronan if a threshold shear stress of 0.2 dyn/cm2 is exceeded. At shear stress ∼1 dyn/cm2, the cell rolling speed reaches a maximum of 15 μm/s. Leukemic Jurkat and Kasumi-1 cells lacking CD44-expression showed no adhesion or rolling on the polysaccharides whereas the CD44-expressing leukemic cells KG-1a, HL-60, K-562, and hematopoietic progenitor cells attached and rolled on hyaluronan. Interestingly, the observations of flow-induced cell rolling are related to those found in the recruitment of leukocytes to inflammatory sites and the mechanisms of stem-cell homing into the bone marrow. PMID:21806926

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smirnov, Sergey V.; Harbacheuski, Ryhor; Lewis-Antes, Anita

Mesenchymal stem cells (MSCs) in bone marrow (BM) regulate the differentiation and proliferation of adjacent hematopoietic precursor cells and contribute to the regeneration of mesenchymal tissues, including bone, cartilage, fat and connective tissue. BM is an important site for the pathogenesis of human cytomegalovirus (HCMV) where the virus establishes latency in hematopoietic progenitors and can transmit after reactivation to neighboring cells. Here we demonstrate that BM-MSCs are permissive to productive HCMV infection, and that HCMV alters the function of MSCs: (i) by changing the repertoire of cell surface molecules in BM-MSCs, HCMV modifies the pattern of interaction between BM-MSCs andmore » hematopoietic cells; (ii) HCMV infection of BM-MSCs undergoing adipogenic or osteogenic differentiation impaired the process of differentiation. Our results suggest that by altering BM-MSC biology, HCMV may contribute to the development of various diseases.« less

Epigenomics in hematopoietic transplantation: novel treatment strategies.

PubMed

Engel, Nicole; Rank, Andreas

2011-10-01

Allogeneic hematopoietic stem cell transplantation is a high risk but curative treatment option for leukemia, myelodysplasia and other hematological malignancies. After high dose radio- or chemo-therapy, recipient's hematopoiesis is replaced by a new immunosystem and residual malignant cells are eliminated by the graft-versus-leukemia reaction. The benefit of this immunological effect is limited by the most frequent complication of hematopoietic stem cell transplantation: graft-versus-host disease. In addition to their well-known anti-tumor activity, epigenetic drugs mediate immunotolerance without reducing alloreactivity or even enhance graft-versus-leukemia effect without inducing graft-versus-host disease by regulating cytokine release, increasing the circulating number of regulatory T cells and interacting with natural killer cells. We focus on the use of epigenetic drugs in the allogeneic transplantation setting in relation to their anti-tumor and immunomodulatory potential.

Deciphering the Developmental Dynamics of the Mouse Liver Transcriptome

PubMed Central

Gunewardena, Sumedha S.; Yoo, Byunggil; Peng, Lai; Lu, Hong; Zhong, Xiaobo; Klaassen, Curtis D.; Cui, Julia Yue

2015-01-01

During development, liver undergoes a rapid transition from a hematopoietic organ to a major organ for drug metabolism and nutrient homeostasis. However, little is known on a transcriptome level of the genes and RNA-splicing variants that are differentially regulated with age, and which up-stream regulators orchestrate age-specific biological functions in liver. We used RNA-Seq to interrogate the developmental dynamics of the liver transcriptome in mice at 12 ages from late embryonic stage (2-days before birth) to maturity (60-days after birth). Among 21,889 unique NCBI RefSeq-annotated genes, 9,641 were significantly expressed in at least one age, 7,289 were differently regulated with age, and 859 had multiple (> = 2) RNA splicing-variants. Factor analysis showed that the dynamics of hepatic genes fall into six distinct groups based on their temporal expression. The average expression of cytokines, ion channels, kinases, phosphatases, transcription regulators and translation regulators decreased with age, whereas the average expression of peptidases, enzymes and transmembrane receptors increased with age. The average expression of growth factors peak between Day-3 and Day-10, and decrease thereafter. We identified critical biological functions, upstream regulators, and putative transcription modules that seem to govern age-specific gene expression. We also observed differential ontogenic expression of known splicing variants of certain genes, and 1,455 novel splicing isoform candidates. In conclusion, the hepatic ontogeny of the transcriptome ontogeny has unveiled critical networks and up-stream regulators that orchestrate age-specific biological functions in liver, and suggest that age contributes to the complexity of the alternative splicing landscape of the hepatic transcriptome. PMID:26496202

Deciphering the Developmental Dynamics of the Mouse Liver Transcriptome.

PubMed

Gunewardena, Sumedha S; Yoo, Byunggil; Peng, Lai; Lu, Hong; Zhong, Xiaobo; Klaassen, Curtis D; Cui, Julia Yue

2015-01-01

During development, liver undergoes a rapid transition from a hematopoietic organ to a major organ for drug metabolism and nutrient homeostasis. However, little is known on a transcriptome level of the genes and RNA-splicing variants that are differentially regulated with age, and which up-stream regulators orchestrate age-specific biological functions in liver. We used RNA-Seq to interrogate the developmental dynamics of the liver transcriptome in mice at 12 ages from late embryonic stage (2-days before birth) to maturity (60-days after birth). Among 21,889 unique NCBI RefSeq-annotated genes, 9,641 were significantly expressed in at least one age, 7,289 were differently regulated with age, and 859 had multiple (> = 2) RNA splicing-variants. Factor analysis showed that the dynamics of hepatic genes fall into six distinct groups based on their temporal expression. The average expression of cytokines, ion channels, kinases, phosphatases, transcription regulators and translation regulators decreased with age, whereas the average expression of peptidases, enzymes and transmembrane receptors increased with age. The average expression of growth factors peak between Day-3 and Day-10, and decrease thereafter. We identified critical biological functions, upstream regulators, and putative transcription modules that seem to govern age-specific gene expression. We also observed differential ontogenic expression of known splicing variants of certain genes, and 1,455 novel splicing isoform candidates. In conclusion, the hepatic ontogeny of the transcriptome ontogeny has unveiled critical networks and up-stream regulators that orchestrate age-specific biological functions in liver, and suggest that age contributes to the complexity of the alternative splicing landscape of the hepatic transcriptome.

Ott1 (Rbm15) regulates thrombopoietin response in hematopoietic stem cells through alternative splicing of c-Mpl

PubMed Central

Xiao, Nan; Laha, Suparna; Das, Shankar P.; Morlock, Kayla; Jesneck, Jonathan L.

2015-01-01

Thrombopoietin (Thpo) signaling through the c-Mpl receptor promotes either quiescence or proliferation of hematopoietic stem cells (HSCs) in a concentration-dependent manner; however, in vivo Thpo serum levels are responsive to platelet mass rather than HSC demands, suggesting additional regulation exists. Ott1 (Rbm15), a spliceosomal component originally identified as a fusion partner in t(1;22)-associated acute megakaryocytic leukemia, is also essential for maintaining HSC quiescence under stress. Ott1 controls the alternative splicing of a dominant negative isoform, Mpl-TR, capable of inhibiting HSC engraftment and attenuating Thpo signaling. Ott1, which associates with Hdac3 and the histone methyltransferase, Setd1b, binds to both c-Mpl RNA and chromatin and regulates H4 acetylation and H3K4me3 marks. Histone deacetylase or histone methyltransferase inhibition also increases Mpl-TR levels, suggesting that Ott1 uses an underlying epigenetic mechanism to control alternative splicing of c-Mpl. Manipulation of Ott1-dependent alternative splicing may therefore provide a novel pharmacologic avenue for regulating HSC quiescence and proliferation in response to Thpo. PMID:25468569

Pten Cell Autonomously Modulates the Hematopoietic Stem Cell Response to Inflammatory Cytokines.

PubMed

Porter, Shaina N; Cluster, Andrew S; Signer, Robert A J; Voigtmann, Jenna; Monlish, Darlene A; Schuettpelz, Laura G; Magee, Jeffrey A

2016-06-14

Pten negatively regulates the phosphatidylinositol 3-kinase (PI3K) pathway and is required to maintain quiescent adult hematopoietic stem cells (HSCs). Pten has been proposed to regulate HSCs cell autonomously and non-cell autonomously, but the relative importance of each mechanism has not been directly tested. Furthermore, the cytokines that activate the PI3K pathway upstream of Pten are not well defined. We sought to clarify whether Pten cell autonomously or non-cell autonomously regulates HSC mobilization. We also tested whether Pten deficiency affects the HSC response to granulocyte colony-stimulating factor (G-CSF) and interferon-α (IFNα) since these cytokines induce HSC mobilization or proliferation, respectively. We show that Pten regulates HSC mobilization and expansion in the spleen primarily via cell-autonomous mechanisms. Pten-deficient HSCs do not require G-CSF to mobilize, although they are hyper-sensitized to even low doses of exogenous G-CSF. Pten-deficient HSCs are similarly sensitized to IFNα. Pten therefore modulates the HSC response to inflammatory cytokines. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

miR-146a deficiency in hematopoietic cells is not involved in the development of atherosclerosis.

PubMed

Del Monte, Alberto; Arroyo, Ana B; Andrés-Manzano, María J; García-Barberá, Nuria; Caleprico, María S; Vicente, Vicente; Roldán, Vanessa; González-Conejero, Rocío; Martínez, Constantino; Andrés, Vicente

2018-01-01

Atherosclerosis involves activation of the IRAK1/TRAF6/NF-κB inflammatory cascade, which is negatively regulated by miR146a. Previous studies showed that the TT genotype of rs2431697, located near the miR-146a gene, drives lower miR-146a transcription and predicts adverse cardiovascular events in anticoagulated atrial fibrillation patients. Moreover, systemic miR-146a administration protects mice from atherosclerosis. Here we evaluated the ability of miR-146a expression in the hematopoietic component to regulate atherosclerosis in low-density lipoprotein receptor-null mice (Ldlr-/-). Lethally-irradiated Ldlr-/- mice transplanted with bone marrow from wild-type or miR-146a-null mice were fed an atherogenic diet for 8 and 20 weeks. Irak1, Traf6 and MIR146A expression were quantified in thoracic aorta by qRT-PCR and Western blot. Aortic plaque size and composition were characterized by Oil-Red staining and immunohistochemistry and leukocyte recruitment by intravital microscopy. Blood cell counts were similar in fat-fed Ldlr-/-mice with or without hematopoietic miR-146a expression. However, plasma cholesterol decreased in fat-fed Ldlr-/-mice transplanted with bone marrow deficient for miR-146a. Finally, aortic atherosclerosis burden and recruitment of leukocytes into the vessel wall were undistinguishable between the two groups, despite higher levels of Irak1 and Traf6 mRNA and protein in the aorta of fat-fed mice lacking hematopoietic miR-146a expression. miR-146a deficiency exclusively in hematopoietic cells modulates cholesterol levels in plasma and the expression of its targets in the artery wall of fat-fed Ldlr-/- mice, but does not accelerate atherosclerosis. Atheroprotection upon systemic miR-146a administration may therefore be caused by specific effects on vascular cells.

Molecular integration of HoxB4 and STAT3 for self-renewal of hematopoietic stem cells: a model of molecular convergence for stemness.

PubMed

Hong, Sung-Hyun; Yang, Seung-Jip; Kim, Tae-Min; Shim, Jae-Seung; Lee, Ho-Sun; Lee, Ga-Young; Park, Bo-Bae; Nam, Suk Woo; Ryoo, Zae Young; Oh, Il-Hoan

2014-05-01

The upregulation of HoxB4 promotes self-renewal of hematopoietic stem cells (HSCs) without overriding the normal stem cell pool size. A similar enhancement of HSC self-renewal occurs when signal transducer and activator of transcription 3 (STAT3) is activated in HSCs. In this study, to gain insight into the functional organization of individual transcription factors (TFs) that have similar effects on HSCs, we investigated the molecular interplay between HoxB4 and STAT3 in the regulation of HSC self-renewal. We found that while STAT3-C or HoxB4 similarly enhanced the in vitro self-renewal and in vivo repopulating activities of HSCs, simultaneous transduction of both TFs did not have additive effects, indicating their functional redundancy in HSCs. In addition, activation of STAT3 did not cause changes in the expression levels of HoxB4. In contrast, the inhibition of STAT3 activity in HoxB4-overexpressing hematopoietic cells significantly abrogated the enhancing effects of HoxB4, and the upregulation of HoxB4 caused a ligand-independent Tyr-phosphorylation of STAT3. Microarray analysis revealed a significant overlap of the transcriptomes regulated by STAT3 and HoxB4 in undifferentiated hematopoietic cells. Moreover, a gene set enrichment analysis showed significant overlap in the candidate TFs that can recapitulate the transcriptional changes induced by HoxB4 or STAT3. Interestingly, among these common TFs were the pluripotency-related genes Oct-4 and Nanog. These results indicate that tissue-specific TFs regulating HSC self-renewal are functionally organized to play an equivalent role in transcription and provide insights into the functional convergence of multiple entries of TFs toward a conserved transcription program for the stem cell state. © 2014 AlphaMed Press.

Symbiont-induced odorant binding proteins mediate insect host hematopoiesis

PubMed Central

Benoit, Joshua B; Vigneron, Aurélien; Broderick, Nichole A; Wu, Yineng; Sun, Jennifer S; Carlson, John R; Aksoy, Serap; Weiss, Brian L

2017-01-01

Symbiotic bacteria assist in maintaining homeostasis of the animal immune system. However, the molecular mechanisms that underlie symbiont-mediated host immunity are largely unknown. Tsetse flies (Glossina spp.) house maternally transmitted symbionts that regulate the development and function of their host’s immune system. Herein we demonstrate that the obligate mutualist, Wigglesworthia, up-regulates expression of odorant binding protein six in the gut of intrauterine tsetse larvae. This process is necessary and sufficient to induce systemic expression of the hematopoietic RUNX transcription factor lozenge and the subsequent production of crystal cells, which actuate the melanotic immune response in adult tsetse. Larval Drosophila’s indigenous microbiota, which is acquired from the environment, regulates an orthologous hematopoietic pathway in their host. These findings provide insight into the molecular mechanisms that underlie enteric symbiont-stimulated systemic immune system development, and indicate that these processes are evolutionarily conserved despite the divergent nature of host-symbiont interactions in these model systems. DOI: http://dx.doi.org/10.7554/eLife.19535.001 PMID:28079523

Altered microRNA expression patterns in irradiated hematopoietic tissues suggest a sex-specific protective mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilnytskyy, Yaroslav; Zemp, Franz J.; Koturbash, Igor

To investigate involvement of miRNAs in radiation responses we used microRNAome profiling to analyze the sex-specific response of radiation sensitive hematopoietic lymphoid tissues. We show that radiation exposure resulted in a significant and sex-specific deregulation of microRNA expression in murine spleen and thymus tissues. Among the regulated miRNAs, we found that changes in expression of miR-34a and miR-7 may be involved in important protective mechanisms counteracting radiation cytotoxicity. We observed a significant increase in the expression of tumor-suppressor miR-34a, paralleled by a decrease in the expression of its target oncogenes NOTCH1, MYC, E2F3 and cyclin D1. Additionally, we show thatmore » miR-7 targets the lymphoid-specific helicase LSH, a pivotal regulator of DNA methylation and genome stability. While miR-7 was significantly down-regulated LSH was significantly up-regulated. These cellular changes may constitute an attempt to counteract radiation-induced hypomethylation. Tissue specificity of miRNA responses and possible regulation of miRNA expression upon irradiation are discussed.« less

Loss of T Cell and B Cell Quiescence Precedes the Onset of Microbial Flora-Dependent Wasting Disease and Intestinal Inflammation in Gimap5-Deficient Mice

PubMed Central

Barnes, Michael J.; Aksoylar, Halil; Krebs, Philippe; Bourdeau, Tristan; Arnold, Carrie N.; Xia, Yu; Khovananth, Kevin; Engel, Isaac; Sovath, Sosathya; Lampe, Kristin; Laws, Eleana; Saunders, Amy; Butcher, Geoffrey W.; Kronenberg, Mitchell; Steinbrecher, Kris; Hildeman, David; Grimes, H. Leighton; Beutler, Bruce; Hoebe, Kasper

2015-01-01

Homeostatic control of the immune system involves mechanisms that ensure the self-tolerance, survival and quiescence of hematopoietic-derived cells. In this study, we demonstrate that the GTPase of immunity associated protein (Gimap)5 regulates these processes in lymphocytes and hematopoietic progenitor cells. As a consequence of a recessive N-ethyl-N-nitrosourea–induced germline mutation in the P-loop of Gimap5, lymphopenia, hepatic extramedullary hematopoiesis, weight loss, and intestinal inflammation occur in homozygous mutant mice. Irradiated fetal liver chimeric mice reconstituted with Gimap5-deficient cells lose weight and become lymphopenic, demonstrating a hematopoietic cell-intrinsic function for Gimap5. Although Gimap5-deficient CD4+ T cells and B cells appear to undergo normal development, they fail to proliferate upon Ag-receptor stimulation although NF-κB, MAP kinase and Akt activation occur normally. In addition, in Gimap5-deficient mice, CD4+ T cells adopt a CD44high CD62Llow CD69low phenotype and show reduced IL-7rα expression, and T-dependent and T-independent B cell responses are abrogated. Thus, Gimap5-deficiency affects a noncanonical signaling pathway required for Ag-receptor–induced proliferation and lymphocyte quiescence. Antibiotic-treatment or the adoptive transfer of Rag-sufficient splenocytes ameliorates intestinal inflammation and weight loss, suggesting that immune responses triggered by microbial flora causes the morbidity in Gimap5-deficient mice. These data establish Gimap5 as a key regulator of hematopoietic integrity and lymphocyte homeostasis. PMID:20190135

Stromal and Hematopoietic Progenitors from C57/BI/6N Murine Bone Marrow After 30-Day "BION-M1" Spaceflight.

PubMed

Markina, Elena; Andreeva, Elena; Andrianova, Irina; Sotnezova, Elena; Buravkova, Ludmila

2018-05-02

Elucidation of the spaceflight (SF) effects on the adult stem and progenitor cells is an important goal in space biology and medicine. A unique opportunity for this was provided by project "BION-M1". The purpose of this study was to evaluate the effects of 30-day SF on biosatellite, 7-day recovery (SFR), and subsequent ground control (GC) experiment on the mononuclear cells (MNCs) from C57/BI/6N murine tibia bone marrow. Also, hematopoietic and stromal precursor functions were characterized ex vivo. There was no significant difference in the total MNC number between experimental groups. After SF, immunophenotyping revealed an increase of large-sized CD45 + MNCs corresponded to committed hematopoietic progenitors. The total hematopoietic colony-forming unit (CFU) number decreased after SF and did not restore after 7 day of recovery due to predominant reduction of bi- and multipotent CFUs and primitive burst-forming units in favor of unipotent CFUs. Functional activity of stromal precursors in vitro was only slightly altered. SF cells displayed the enhanced expression of alkaline phosphatase. The data of the GC experiment demonstrated the preservation of the functional activity of progenitor cells from mice bone marrow. The activation of erythropoiesis in expense of burst-forming units of erythrocytes elevation was detected. After 7 days of recovery, the number of colony-forming units of fibroblast (CFUs-f) was similar to the vivarium control, while the proliferative activity of bone marrow stromal precursors decreased. The present study demonstrated that certain hematopoietic progenitors are susceptible to SF factors, while the stromal precursors displayed a certain degree of resistance. These data indicate mild and reversible alterations of bone marrow progenitors after SF.

Enumerating Hematopoietic Stem and Progenitor Cells in Zebrafish Embryos.

PubMed

Esain, Virginie; Cortes, Mauricio; North, Trista E

2016-01-01

Over the past 20 years, zebrafish have proven to be a valuable model to dissect the signaling pathways involved in hematopoiesis, including Hematopoietic Stem and Progenitor Cell (HSPC) formation and homeostasis. Despite tremendous efforts to generate the tools necessary to characterize HSPCs in vitro and in vivo the zebrafish community still lacks standardized methods to quantify HSPCs across laboratories. Here, we describe three methods used routinely in our lab, and in others, to reliably enumerate HSPCs in zebrafish embryos: large-scale live imaging of transgenic reporter lines, Fluorescence-Activated Cell Sorting (FACS), and in vitro cell culture. While live imaging and FACS analysis allows enumeration of total or site-specific HSPCs, the cell culture assay provides the unique opportunity to test the functional potential of isolated HSPCs, similar to those employed in mammals.

CD44-mediated hyaluronan binding marks proliferating hematopoietic progenitor cells and promotes bone marrow engraftment

PubMed Central

Lee-Sayer, Sally S. M.; Dougan, Meghan N.; Cooper, Jesse; Sanderson, Leslie; Dosanjh, Manisha; Maxwell, Christopher A.

2018-01-01

CD44 is a widely expressed cell adhesion molecule that binds to the extracellular matrix component, hyaluronan. However, this interaction is not constitutive in most immune cells at steady state, as the ability of CD44 to engage hyaluronan is highly regulated. While activated T cells and macrophages gain the ability to bind hyaluronan by CD44, the status in other immune cells is less studied. Here we found a percentage of murine eosinophils, natural killer and natural killer T cells were capable of interacting with hyaluronan at steady state. To further investigate the consequences of hyaluronan binding by CD44 in the hematopoietic system, point mutations of CD44 that either cannot bind hyaluronan (LOF-CD44) or have an increased affinity for hyaluronan (GOF-CD44) were expressed in CD44-deficient bone marrow. Competitive bone marrow reconstitution of irradiated mice revealed an early preference for GOF-CD44 over WT-CD44 expressing cells, and for WT-CD44 over LOF-CD44 expressing cells, in the hematopoietic progenitor cell compartment. The advantage of the hyaluronan-binding cells was observed in the hematopoietic stem and progenitor populations, and was maintained throughout the immune system. Hematopoietic stem cells bound minimal hyaluronan at steady state, and this was increased when the cells were induced to proliferate whereas multipotent progenitors had an increased ability to bind hyaluronan at steady state. In vitro, the addition of hyaluronan promoted their proliferation. Thus, proliferating hematopoietic progenitors bind hyaluronan, and hyaluronan binding cells have a striking competitive advantage in bone marrow engraftment. PMID:29684048

Deregulation of vital mitotic kinase-phosphatase signaling in hematopoietic stem/progenitor compartment leads to cellular catastrophe in experimental aplastic anemia.

PubMed

Chatterjee, Ritam; Chattopadhyay, Sukalpa; Law, Sujata

2016-11-01

Aplastic anemia, the paradigm of bone marrow failure, is characterized by pancytopenic peripheral blood and hypoplastic bone marrow. Among various etiologies, inappropriate use of DNA alkylating drugs like cyclophosphamide and busulfan often causes the manifestation of the dreadful disease. Cell cycle impairment in marrow hematopoietic stem/progenitor compartment together with cellular apoptosis has been recognized as culpable factors behind aplastic pathophysiologies. However, the intricate molecular mechanisms remain unrevealed till date. In the present study, we have dealt with the mechanistic intervention of the disease by peripheral blood hemogram, bone marrow histopathology, cytopathology, hematopoietic kinetic study, scanning electron microscopy, DNA damage assessment and flowcytometric analysis of cellular proliferation and apoptosis in hematopoietic stem/progenitor cell (HSPC) rich marrow compartment using busulfan and cyclophosphamidemediated mouse model. To unveil the molecular mechanisms behind aplastic pathophysiology, we further investigated the role of some crucial mitotic and apoptotic regulators like Protein kinase-B (PKB), Gsk-3β, Cyclin-D1, PP2A, Cdc25c, Plk-1, Aurora kinase-A, Chk-1 regarding the hematopoietic catastrophe. Our observations revealed that the alteration of PKB-GSK-3β axis, Plk-1, and Aurora kinase-A expressions in HSPC compartment due to DNA damage response was associated with the proliferative impairment and apoptosis during aplastic anemia. The study established the correlation between the accumulation of DNA damage and alteration of the mentioned molecules in aplastic HSPCs that lead to the hematopoietic catastrophe. We anticipate that our findings will be beneficial for developing better therapeutic strategies for the dreadful disease concerned.

Regulated Apoptosis of Genetically-Modified Hematopoietic Stem and Progenitor Cells via an Inducible Caspase-9 Suicide Gene in Rhesus Macaques

PubMed Central

Barese, Cecilia N.; Felizardo, Tania C.; Sellers, Stephanie E.; Keyvanfar, Keyvan; Di Stasi, Antonio; Metzger, Mark E.; Krouse, Allen E.; Donahue, Robert E.; Spencer, David M.; Dunbar, Cynthia E.

2014-01-01

The high risk of insertional oncogenesis reported in clinical trials utilizing integrating retroviral vectors to genetically-modify hematopoietic stem and progenitor cells (HSPC) requires the development of safety strategies to minimize risks associated with novel cell and gene therapies. The ability to ablate genetically modified cells in vivo is desirable, should an abnormal clone emerge. Inclusion of “suicide genes” in vectors to facilitate targeted ablation of vector-containing abnormal clones in vivo is one potential safety approach. We tested whether the inclusion of the “inducible Caspase-9” (iCasp9) suicide gene in a gamma-retroviral vector facilitated efficient elimination of vector-containing HSPCs and their hematopoietic progeny in vivo long-term, in an autologous non-human primate transplantation model. Following stable engraftment of iCasp9 expressing hematopoietic cells in rhesus macaques, administration of AP1903, a chemical inducer of dimerization able to activate iCasp9, specifically eliminated vector-containing cells in all hematopoietic lineages long-term, suggesting activity at the HSPC level. Between 75–94% of vector-containing cells were eliminated by well-tolerated AP1903 dosing, but lack of complete ablation was linked to lower iCasp9 expression in residual cells. Further investigation of resistance mechanisms demonstrated upregulation of Bcl-2 in hematopoietic cell lines transduced with the vector and resistant to AP1903 ablation. These results demonstrate both the potential and the limitations of safety approaches utilizing iCasp9 to HSPC-targeted gene therapy settings, in a model with great relevance to clinical development. PMID:25330775

Histone acetyltransferase activity of MOF is required for adult but not early fetal hematopoiesis in mice.

PubMed

Valerio, Daria G; Xu, Haiming; Eisold, Meghan E; Woolthuis, Carolien M; Pandita, Tej K; Armstrong, Scott A

2017-01-05

K(lysine) acetyltransferase 8 (KAT8, also known as MOF) mediates the acetylation of histone H4 at lysine 16 (H4K16ac) and is crucial for murine embryogenesis. Lysine acetyltransferases have been shown to regulate various stages of normal hematopoiesis. However, the function of MOF in hematopoietic stem cell (HSC) development has not yet been elucidated. We set out to study the role of MOF in general hematopoiesis by using a Vav1-cre-induced conditional murine Mof knockout system and found that MOF is critical for hematopoietic cell maintenance and HSC engraftment capacity in adult hematopoiesis. Rescue experiments with a MOF histone acetyltransferase domain mutant illustrated the requirement for MOF acetyltransferase activity in the clonogenic capacity of HSCs and progenitors. In stark contrast, fetal steady-state hematopoiesis at embryonic day (E) 14.5 was not affected by homozygous Mof deletion despite dramatic loss of global H4K16ac. Hematopoietic defects start manifesting in late gestation at E17.5. The discovery that MOF and its H4K16ac activity are required for adult but not early and midgestational hematopoiesis supports the notion that multiple chromatin regulators may be crucial for hematopoiesis at varying stages of development. MOF is therefore a developmental-stage-specific chromatin regulator found to be essential for adult but not early fetal hematopoiesis. © 2017 by The American Society of Hematology.

Endothelial jagged-2 sustains hematopoietic stem and progenitor reconstitution after myelosuppression.

PubMed

Guo, Peipei; Poulos, Michael G; Palikuqi, Brisa; Badwe, Chaitanya R; Lis, Raphael; Kunar, Balvir; Ding, Bi-Sen; Rabbany, Sina Y; Shido, Koji; Butler, Jason M; Rafii, Shahin

2017-12-01

Angiocrine factors, such as Notch ligands, supplied by the specialized endothelial cells (ECs) within the bone marrow and splenic vascular niche play an essential role in modulating the physiology of adult hematopoietic stem and progenitor cells (HSPCs). However, the relative contribution of various Notch ligands, specifically jagged-2, to the homeostasis of HSPCs is unknown. Here, we show that under steady state, jagged-2 is differentially expressed in tissue-specific vascular beds, but its expression is induced in hematopoietic vascular niches after myelosuppressive injury. We used mice with EC-specific deletion of the gene encoding jagged-2 (Jag2) to demonstrate that while EC-derived jagged-2 was dispensable for maintaining the capacity of HSPCs to repopulate under steady-state conditions, by activating Notch2 it did contribute to the recovery of HSPCs in response to myelosuppressive conditions. Engraftment and/or expansion of HSPCs was dependent on the expression of endothelial-derived jagged-2 following myeloablation. Additionally, jagged-2 expressed in bone marrow ECs regulated HSPC cell cycle and quiescence during regeneration. Endothelial-deployed jagged-2 triggered Notch2/Hey1, while tempering Notch2/Hes1 signaling in HSPCs. Collectively, these data demonstrate that EC-derived jagged-2 activates Notch2 signaling in HSPCs to promote hematopoietic recovery and has potential as a therapeutic target to accelerate balanced hematopoietic reconstitution after myelosuppression.

Endothelial jagged-2 sustains hematopoietic stem and progenitor reconstitution after myelosuppression

PubMed Central

Guo, Peipei; Poulos, Michael G.; Palikuqi, Brisa; Badwe, Chaitanya R.; Lis, Raphael; Kunar, Balvir; Ding, Bi-Sen; Rabbany, Sina Y.; Butler, Jason M.

2017-01-01

Angiocrine factors, such as Notch ligands, supplied by the specialized endothelial cells (ECs) within the bone marrow and splenic vascular niche play an essential role in modulating the physiology of adult hematopoietic stem and progenitor cells (HSPCs). However, the relative contribution of various Notch ligands, specifically jagged-2, to the homeostasis of HSPCs is unknown. Here, we show that under steady state, jagged-2 is differentially expressed in tissue-specific vascular beds, but its expression is induced in hematopoietic vascular niches after myelosuppressive injury. We used mice with EC-specific deletion of the gene encoding jagged-2 (Jag2) to demonstrate that while EC-derived jagged-2 was dispensable for maintaining the capacity of HSPCs to repopulate under steady-state conditions, by activating Notch2 it did contribute to the recovery of HSPCs in response to myelosuppressive conditions. Engraftment and/or expansion of HSPCs was dependent on the expression of endothelial-derived jagged-2 following myeloablation. Additionally, jagged-2 expressed in bone marrow ECs regulated HSPC cell cycle and quiescence during regeneration. Endothelial-deployed jagged-2 triggered Notch2/Hey1, while tempering Notch2/Hes1 signaling in HSPCs. Collectively, these data demonstrate that EC-derived jagged-2 activates Notch2 signaling in HSPCs to promote hematopoietic recovery and has potential as a therapeutic target to accelerate balanced hematopoietic reconstitution after myelosuppression. PMID:29058691

Ability of circulating human hematopoietic lineage negative cells to support hematopoiesis.

PubMed

Peris, Pilar; Roforth, Matthew M; Nicks, Kristy M; Fraser, Daniel; Fujita, Koji; Jilka, Robert L; Khosla, Sundeep; McGregor, Ulrike

2015-01-01

Hematopoietic stem cell (HSC) self-renewal is regulated by osteoblast and/or endothelial cells within the hematopoietic niche. However, the true identity of the supporting cells and the nature of the secreted factors remain uncertain. We developed a novel mouse model and analyzed whether circulating human peripheral hematopoietic lineage negative/AP+ (lin-/AP+) cells support hematopoiesis in vivo. Thus, immunocompromised (Rag) mice expressing thymidine kinase (Tk) under the control of the 3.6Col1α1 promoter (Tk-Rag) were treated with ganciclovir, resulting in osteoblast progenitor cell ablation and subsequent loss of hematopoiesis (evaluated by measuring mouse Ter119+ erythroid cells). Following hematopoietic cell depletion, human bone marrow-derived marrow stromal cells (MSCs) or lin-/AP+ cells were infused into Tk-Rag mice and compared with saline infusions. Ganciclovir significantly reduced (7.4-fold) Ter119+ cells in the bone marrow of Tk-Rag mice compared to saline injections. Infusion of either MSCs or lin-/AP+ cells into ganciclovir-treated mice resulted in a 3.3-fold and 2.7-fold increase (P < 0.01), respectively, in Ter119+ cells compared to mice receiving saline. Relative to lin-/AP- cells, lin-/AP+ cells expressed high levels of mesenchymal, endothelial, and hematopoiesis supporting genes. Thus, human peripheral blood lin-/AP+ cells represent a novel cell type capable of supporting hematopoiesis in a manner comparable to MSCs. © 2014 Wiley Periodicals, Inc.

Deletion of Asxl1 results in myelodysplasia and severe developmental defects in vivo

PubMed Central

Abdel-Wahab, Omar; Gao, Jie; Adli, Mazhar; Dey, Anwesha; Trimarchi, Thomas; Chung, Young Rock; Kuscu, Cem; Hricik, Todd; Ndiaye-Lobry, Delphine; LaFave, Lindsay M.; Koche, Richard; Shih, Alan H.; Guryanova, Olga A.; Kim, Eunhee; Li, Sheng; Pandey, Suveg; Shin, Joseph Y.; Telis, Leon; Liu, Jinfeng; Bhatt, Parva K.; Monette, Sebastien; Zhao, Xinyang; Mason, Christopher E.; Park, Christopher Y.; Bernstein, Bradley E.

2013-01-01

Somatic Addition of Sex Combs Like 1 (ASXL1) mutations occur in 10–30% of patients with myeloid malignancies, most commonly in myelodysplastic syndromes (MDSs), and are associated with adverse outcome. Germline ASXL1 mutations occur in patients with Bohring-Opitz syndrome. Here, we show that constitutive loss of Asxl1 results in developmental abnormalities, including anophthalmia, microcephaly, cleft palates, and mandibular malformations. In contrast, hematopoietic-specific deletion of Asxl1 results in progressive, multilineage cytopenias and dysplasia in the context of increased numbers of hematopoietic stem/progenitor cells, characteristic features of human MDS. Serial transplantation of Asxl1-null hematopoietic cells results in a lethal myeloid disorder at a shorter latency than primary Asxl1 knockout (KO) mice. Asxl1 deletion reduces hematopoietic stem cell self-renewal, which is restored by concomitant deletion of Tet2, a gene commonly co-mutated with ASXL1 in MDS patients. Moreover, compound Asxl1/Tet2 deletion results in an MDS phenotype with hastened death compared with single-gene KO mice. Asxl1 loss results in a global reduction of H3K27 trimethylation and dysregulated expression of known regulators of hematopoiesis. RNA-Seq/ChIP-Seq analyses of Asxl1 in hematopoietic cells identify a subset of differentially expressed genes as direct targets of Asxl1. These findings underscore the importance of Asxl1 in Polycomb group function, development, and hematopoiesis. PMID:24218140

Protein Kinase C Enzymes in the Hematopoietic and Immune Systems.

PubMed

Altman, Amnon; Kong, Kok-Fai

2016-05-20

The protein kinase C (PKC) family, discovered in the late 1970s, is composed of at least 10 serine/threonine kinases, divided into three groups based on their molecular architecture and cofactor requirements. PKC enzymes have been conserved throughout evolution and are expressed in virtually all cell types; they represent critical signal transducers regulating cell activation, differentiation, proliferation, death, and effector functions. PKC family members play important roles in a diverse array of hematopoietic and immune responses. This review covers the discovery and history of this enzyme family, discusses the roles of PKC enzymes in the development and effector functions of major hematopoietic and immune cell types, and points out gaps in our knowledge, which should ignite interest and further exploration, ultimately leading to better understanding of this enzyme family and, above all, its role in the many facets of the immune system.

Mitophagy in hematopoietic stem cells

PubMed Central

Joshi, Aashish; Kundu, Mondira

2013-01-01

Hematopoietic stem cells (HSCs) are inherently quiescent and self-renewing, yet can differentiate and commit to multiple blood cell types. Intracellular mitochondrial content is dynamic, and there is an increase in mitochondrial content during differentiation and lineage commitment in HSCs. HSCs reside in a hypoxic niche within the bone marrow and rely heavily on glycolysis, while differentiated and committed progenitors rely on oxidative phosphorylation. Increased oxidative phosphorylation during differentiation and commitment is not only due to increased mitochondrial content but also due to changes in mitochondrial cytosolic distribution and efficiency. These changes in the intracellular mitochondrial landscape contribute signals toward regulating differentiation and commitment. Thus, a functional relationship exists between the mitochondria in HSCs and the state of the HSCs (i.e., stemness vs. differentiated). This review focuses on how autophagy-mediated mitochondrial clearance (i.e., mitophagy) may affect HSC mitochondrial content, thereby influencing the fate of HSCs and maintenance of hematopoietic homeostasis. PMID:24135495

Eosinophil-derived CCL-6 impairs hematopoietic stem cell homeostasis

PubMed Central

Zhang, Chao; Yi, Weiwei; Li, Fei; Du, Xufei; Wang, Hu; Wu, Ping; Peng, Chao; Luo, Man; Hua, Wen; Wong, Catherine CL; Lee, James J; Li, Wen; Chen, Zhihua; Ying, Songmin; Ju, Zhenyu; Shen, Huahao

2018-01-01

Eosinophils (Eos) have been long considered as end-stage effector cells in the hierarchical hematopoietic system. Numerous lines of evidence have suggested that Eos are multifunctional leukocytes with respect to the initiation, propagation and regulation of various inflammatory or immune reactions, especially in allergic diseases. Recent studies have shown that Eos are also required for maintenance of bone marrow plasma cells and differentiation of B cells. However, it remains unclear whether Eos contributes to regulation of hematopoietic stem cell (HSC) homeostasis. Here, we demonstrate that Eos disrupt HSC homeostasis by impairing HSC quiescence and reconstitution ability in wild-type mice following ovalbumin (OVA) challenge and even by causing bone marrow HSC failure and exhaustion in Cd3δ-Il-5 transgenic mice. The impaired maintenance and function of HSCs were associated with Eos-induced redox imbalance (increased oxidative phosphorylation and decreased anti-oxidants levels). More importantly, using mass spectrometry, we determined that CCL-6 is expressed at a high level under eosinophilia. We demonstrate that CCL-6 is Eos-derived and responsible for the impaired HSC homeostasis. Interestingly, blockage of CCL-6 with a specific neutralizing antibody, restored the reconstitution ability of HSCs while exacerbating eosinophilia airway inflammation in OVA-challenged mice. Thus, our study reveals an unexpected function of Eos/CCL-6 in HSC homeostasis. PMID:29327730

Regulation of Hematopoietic Stem Cell Behavior by the Nanostructured Presentation of Extracellular Matrix Components

PubMed Central

Muth, Christine Anna; Steinl, Carolin; Klein, Gerd; Lee-Thedieck, Cornelia

2013-01-01

Hematopoietic stem cells (HSCs) are maintained in stem cell niches, which regulate stem cell fate. Extracellular matrix (ECM) molecules, which are an essential part of these niches, can actively modulate cell functions. However, only little is known on the impact of ECM ligands on HSCs in a biomimetic environment defined on the nanometer-scale level. Here, we show that human hematopoietic stem and progenitor cell (HSPC) adhesion depends on the type of ligand, i.e., the type of ECM molecule, and the lateral, nanometer-scaled distance between the ligands (while the ligand type influenced the dependency on the latter). For small fibronectin (FN)–derived peptide ligands such as RGD and LDV the critical adhesive interligand distance for HSPCs was below 45 nm. FN-derived (FN type III 7–10) and osteopontin-derived protein domains also supported cell adhesion at greater distances. We found that the expression of the ECM protein thrombospondin-2 (THBS2) in HSPCs depends on the presence of the ligand type and its nanostructured presentation. Functionally, THBS2 proved to mediate adhesion of HSPCs. In conclusion, the present study shows that HSPCs are sensitive to the nanostructure of their microenvironment and that they are able to actively modulate their environment by secreting ECM factors. PMID:23405094

Eosinophil-derived CCL-6 impairs hematopoietic stem cell homeostasis.

PubMed

Zhang, Chao; Yi, Weiwei; Li, Fei; Du, Xufei; Wang, Hu; Wu, Ping; Peng, Chao; Luo, Man; Hua, Wen; Wong, Catherine Cl; Lee, James J; Li, Wen; Chen, Zhihua; Ying, Songmin; Ju, Zhenyu; Shen, Huahao

2018-03-01

Eosinophils (Eos) have been long considered as end-stage effector cells in the hierarchical hematopoietic system. Numerous lines of evidence have suggested that Eos are multifunctional leukocytes with respect to the initiation, propagation and regulation of various inflammatory or immune reactions, especially in allergic diseases. Recent studies have shown that Eos are also required for maintenance of bone marrow plasma cells and differentiation of B cells. However, it remains unclear whether Eos contributes to regulation of hematopoietic stem cell (HSC) homeostasis. Here, we demonstrate that Eos disrupt HSC homeostasis by impairing HSC quiescence and reconstitution ability in wild-type mice following ovalbumin (OVA) challenge and even by causing bone marrow HSC failure and exhaustion in Cd3δ-Il-5 transgenic mice. The impaired maintenance and function of HSCs were associated with Eos-induced redox imbalance (increased oxidative phosphorylation and decreased anti-oxidants levels). More importantly, using mass spectrometry, we determined that CCL-6 is expressed at a high level under eosinophilia. We demonstrate that CCL-6 is Eos-derived and responsible for the impaired HSC homeostasis. Interestingly, blockage of CCL-6 with a specific neutralizing antibody, restored the reconstitution ability of HSCs while exacerbating eosinophilia airway inflammation in OVA-challenged mice. Thus, our study reveals an unexpected function of Eos/CCL-6 in HSC homeostasis.

Transcription factor GATA-1 regulates human HOXB2 gene expression in erythroid cells.

PubMed

Vieille-Grosjean, I; Huber, P

1995-03-03

The human HOXB2 gene is a member of the vertebrate Hox gene family that contains genes coding for specific developmental stage DNA-binding proteins. Remarkably, within the hematopoietic compartment, genes of the HOXB complex are expressed specifically in erythromegakaryocytic cell lines and, for some of them, in hematopoietic progenitors. Here, we report the study of HOXB2 gene transcriptional regulation in hematopoietic cells, an initial step in understanding the lineage-specific expression of the whole HOXB complex in these cells. We have isolated the HOXB2 5'-flanking sequence and have characterized a promoter fragment extending 323 base pairs upstream from the transcriptional start site, which, in transfection experiments, was sufficient to direct the tissue-specific expression of HOXB2 in the erythroid cell line K562. In this fragment, we have identified a potential GATA-binding site that is essential to the promoter activity as demonstrated by point mutation experiments. Gel shift analysis revealed the formation of a specific complex in both erythroleukemic lines K562 and HEL that could be prevented by the addition of a specific antiserum raised against GATA-1 protein. These findings suggest a regulatory hierarchy in which GATA-1 is upstream of the HOXB2 gene in erythroid cells.

An integrated global regulatory network of hematopoietic precursor cell self-renewal and differentiation.

PubMed

You, Yanan; Cuevas-Diaz Duran, Raquel; Jiang, Lihua; Dong, Xiaomin; Zong, Shan; Snyder, Michael; Wu, Jia Qian

2018-06-12

Systematic study of the regulatory mechanisms of Hematopoietic Stem Cell and Progenitor Cell (HSPC) self-renewal is fundamentally important for understanding hematopoiesis and for manipulating HSPCs for therapeutic purposes. Previously, we have characterized gene expression and identified important transcription factors (TFs) regulating the switch between self-renewal and differentiation in a multipotent Hematopoietic Progenitor Cell (HPC) line, EML (Erythroid, Myeloid, and Lymphoid) cells. Herein, we report binding maps for additional TFs (SOX4 and STAT3) by using chromatin immunoprecipitation (ChIP)-Sequencing, to address the underlying mechanisms regulating self-renewal properties of lineage-CD34+ subpopulation (Lin-CD34+ EML cells). Furthermore, we applied the Assay for Transposase Accessible Chromatin (ATAC)-Sequencing to globally identify the open chromatin regions associated with TF binding in the self-renewing Lin-CD34+ EML cells. Mass spectrometry (MS) was also used to quantify protein relative expression levels. Finally, by integrating the protein-protein interaction database, we built an expanded transcriptional regulatory and interaction network. We found that MAPK (Mitogen-activated protein kinase) pathway and TGF-β/SMAD signaling pathway components were highly enriched among the binding targets of these TFs in Lin-CD34+ EML cells. The present study integrates regulatory information at multiple levels to paint a more comprehensive picture of the HSPC self-renewal mechanisms.

Loss of Cbl and Cbl-b ubiquitin ligases abrogates hematopoietic stem cell quiescence and sensitizes leukemic disease to chemotherapy

PubMed Central

An, Wei; Nadeau, Scott A.; Mohapatra, Bhopal C.; Feng, Dan; Zutshi, Neha; Storck, Matthew D.; Arya, Priyanka; Talmadge, James E.; Meza, Jane L.; Band, Vimla; Band, Hamid

2015-01-01

Cbl and Cbl-b are tyrosine kinase-directed RING finger type ubiquitin ligases (E3s) that negatively regulate cellular activation pathways. E3 activity-disrupting human Cbl mutations are associated with myeloproliferative disorders (MPD) that are reproduced in mice with Cbl RING finger mutant knock-in or hematopoietic Cbl and Cbl-b double knockout. However, the role of Cbl proteins in hematopoietic stem cell (HSC) homeostasis, especially in the context of MPD is unclear. Here we demonstrate that HSC expansion and MPD development upon combined Cbl and Cbl-b deletion are dependent on HSCs. Cell cycle analysis demonstrated that DKO HSCs exhibit reduced quiescence associated with compromised reconstitution ability and propensity to undergo exhaustion. We show that sustained c-Kit and FLT3 signaling in DKO HSCs promotes loss of colony-forming potential, and c-Kit or FLT3 inhibition in vitro protects HSCs from exhaustion. In vivo, treatment with 5-fluorouracil hastens DKO HSC exhaustion and protects mice from death due to MPD. Our data reveal a novel and leukemia therapy-relevant role of Cbl and Cbl-b in the maintenance of HSC quiescence and protection against exhaustion, through negative regulation of tyrosine kinase-coupled receptor signaling. PMID:25871390

Mechanism of enhanced hematopoietic response by soluble beta-glucan SCG in cyclophosphamide-treated mice.

PubMed

Harada, Toshie; Kawaminami, Hiromi; Miura, Noriko N; Adachi, Yoshiyuki; Nakajima, Mitsuhiro; Yadomae, Toshiro; Ohno, Naohito

2006-01-01

SCG is a major 6-branched 1,3-beta-D-glucan in Sparassis crispa Fr. SCG shows antitumor activity and also enhances the hematopoietic response in cyclophosphamide (CY)-treated mice. In the present study, the molecular mechanism of the enhancement of the hematopoietic response was investigated. The levels of interferon-(IFN-)gamma, tumor necrosis factor-(TNF-)alpha, granulocyte-macrophage-colony stimulating factor (GM-CSF), interleukin-(IL-) 6 and IL-12p70 were significantly increased by SCG in CY-treated mice. GM-CSF production in the splenocytes from the CY-treated mice was higher than that in normal mice regardless of SCG stimulation. Neutralizing GM-CSF significantly inhibited the induction of IFN-gamma, TNF-alpha and IL-12p70 by SCG. The level of cytokine induction by SCG was regulated by the amount of endogenous GM-CSF produced in response to CY treatment in a dose-dependent manner. The expression of beta-glucan receptors, such as CR3 and dectin-1, was up-regulated by CY treatment. Blocking dectin-1 significantly inhibited the induction of TNF-alpha and IL-12p70 production by SCG. Taken together, these results suggest that the key factors in the cytokine induction in CY-treated mice were the enhanced levels of both endogenous GM-CSF production and dectin-1 expression.

Epigenetic regulation of hematopoietic stem cell aging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beerman, Isabel, E-mail: isabel.beerman@childrens.harvard.edu; Department of Pediatrics, Harvard Medical School, Boston, MA 02115; Program in Cellular and Molecular Medicine, Division of Hematology/Oncology, Boston Children's Hospital, MA 02116

2014-12-10

Aging is invariably associated with alterations of the hematopoietic stem cell (HSC) compartment, including loss of functional capacity, altered clonal composition, and changes in lineage contribution. Although accumulation of DNA damage occurs during HSC aging, it is unlikely such consistent aging phenotypes could be solely attributed to changes in DNA integrity. Another mechanism by which heritable traits could contribute to the changes in the functional potential of aged HSCs is through alterations in the epigenetic landscape of adult stem cells. Indeed, recent studies on hematopoietic stem cells have suggested that altered epigenetic profiles are associated with HSC aging and playmore » a key role in modulating the functional potential of HSCs at different stages during ontogeny. Even small changes of the epigenetic landscape can lead to robustly altered expression patterns, either directly by loss of regulatory control or through indirect, additive effects, ultimately leading to transcriptional changes of the stem cells. Potential drivers of such changes in the epigenetic landscape of aged HSCs include proliferative history, DNA damage, and deregulation of key epigenetic enzymes and complexes. This review will focus largely on the two most characterized epigenetic marks – DNA methylation and histone modifications – but will also discuss the potential role of non-coding RNAs in regulating HSC function during aging.« less

Remuneration of hematopoietic stem cell donors: principles and perspective of the World Marrow Donor Association.

PubMed

Boo, Michael; van Walraven, Suzanna M; Chapman, Jeremy; Lindberg, Brian; Schmidt, Alexander H; Shaw, Bronwen E; Switzer, Galen E; Yang, Edward; Egeland, Torstein

2011-01-06

Hematopoietic stem cell transplantation is a curative procedure for life-threatening hematologic diseases. Donation of hematopoietic stem cells (HSCs) from an unrelated donor, frequently residing in another country, may be the only option for 70% of those in need of unrelated hematopoietic stem cell transplantation. To maximize the opportunity to find the best available donor, individual donor registries collaborate internationally. To provide homogeneity of practice among registries, the World Marrow Donor Association (WMDA) sets standards against which registries are accredited and provides guidance and regulations about unrelated donor safety and care. A basic tenet of the donor registries is that unrelated HSC donation is an altruistic act; nonpayment of donors is entrenched in the WMDA standards and in international practice. In the United States, the prohibition against remuneration of donors has recently been challenged. Here, we describe the reasons that the WMDA continues to believe that HSC donors should not be paid because of ethical concerns raised by remuneration, potential to damage the public will to act altruistically, the potential for coercion and exploitation of donors, increased risk to patients, harm to local transplantation programs and international stem cell exchange, and the possibility of benefiting some patients while disadvantaging others.

Brief Reports: Nfix Promotes Survival of Immature Hematopoietic Cells via Regulation of c-Mpl.

PubMed

Hall, Trent; Walker, Megan; Ganuza, Miguel; Holmfeldt, Per; Bordas, Marie; Kang, Guolian; Bi, Wenjian; Palmer, Lance E; Finkelstein, David; McKinney-Freeman, Shannon

2018-02-12

Hematopoietic stem and progenitor cells (HSPCs) are necessary for life-long blood production and replenishment of the hematopoietic system during stress. We recently reported that nuclear factor I/X (Nfix) promotes HSPC survival post-transplant. Here, we report that ectopic expression of Nfix in primary mouse HSPCs extends their ex vivo culture from about 20 to 40 days. HSPCs overexpressing Nfix display hypersensitivity to supportive cytokines and reduced apoptosis when subjected to cytokine deprivation relative to controls. Ectopic Nfix resulted in elevated levels of c-Mpl transcripts and cell surface protein on primary murine HSPCs as well as increased phosphorylation of STAT5, which is known to be activated down-stream of c-MPL. Blocking c-MPL signaling by removal of thrombopoietin or addition of a c-MPL neutralizing antibody negated the antiapoptotic effect of Nfix overexpression on cultured HSPCs. Furthermore, NFIX was capable of binding to and transcriptionally activating a proximal c-Mpl promoter fragment. In sum, these data suggest that NFIX-mediated upregulation of c-Mpl transcription can protect primitive hematopoietic cells from stress ex vivo. Stem Cells 2018. © AlphaMed Press 2018.

The role of telomeres and telomerase complex in haematological neoplasia: the length of telomeres as a marker of carcinogenesis and prognosis of disease.

PubMed

Gancarcíková, M; Zemanová, Z; Brezinová, J; Berková, A; Vcelíková, S; Smigová, J; Michalová, K

2010-01-01

Human telomeres (discovery of telomere structure and function has been recently awarded The Nobel Prize) consist of approximately 5-12 kb of tandem repeated sequences (TTAGGG)n and associated proteins capping chromosome ends which prevent degradation, loss of genetic information, end-to-end fusion, senescence and apoptosis. Due to the end-replication problem, telomere repeats are lost with each cell division, eventually leading to genetic instability and cellular senescence when telomeres become critically short. Stabilization of the telomeric DNA through telomerase activation, unique reverse transcriptase, or activation of the alternative mechanism of telomere maintenance is essential if the cells are to survive and proliferate indefinitely. Telomerase is expressed during early development and remains fully active in specific germline cells, but is undetectable in most normal somatic cells. High level of telomerase activity is detected in almost 90% of human tumours and immortalized cell lines. The hematopoietic compartment may develop genetic instability as a consequence of telomere erosion, resulting in aplastic anaemia (AA) and increased risk of myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML). Genetic instability associated with telomere dysfunction (i.e. short telomeres) is an early event in carcinogenesis. The molecular cytogenetic method telomere/centromere fluorescence in situ hybridization (T/C-FISH) can be used to characterize the telomere length of hematopoietic cells. This review describes recent advances in the molecular characterization of telomere system, the regulation of telomerase activity in cancer pathogenesis and shows that the telomeric length could be a potential clinical marker of hematologic neoplasia and prognosis of disease.

Mammary Gland Involution Provides a Unique Model to Study the TGF-β Cancer Paradox

PubMed Central

Guo, Qiuchen; Betts, Courtney; Pennock, Nathan; Mitchell, Elizabeth; Schedin, Pepper

2017-01-01

Transforming Growth Factor-β (TGF-β) signaling in cancer has been termed the “TGF-β paradox”, acting as both a tumor suppresser and promoter. The complexity of TGF-β signaling within the tumor is context dependent, and greatly impacted by cellular crosstalk between TGF-β responsive cells in the microenvironment including adjacent epithelial, endothelial, mesenchymal, and hematopoietic cells. Here we utilize normal, weaning-induced mammary gland involution as a tissue microenvironment model to study the complexity of TGF-β function. This article reviews facets of mammary gland involution that are TGF-β regulated, namely mammary epithelial cell death, immune activation, and extracellular matrix remodeling. We outline how distinct cellular responses and crosstalk between cell types during physiologically normal mammary gland involution contribute to simultaneous tumor suppressive and promotional microenvironments. We also highlight alternatives to direct TGF-β blocking anti-cancer therapies with an emphasis on eliciting concerted microenvironmental-mediated tumor suppression. PMID:28098775

New insights into the mechanisms of mammalian erythroid chromatin condensation and enucleation.

PubMed

Ji, Peng

2015-01-01

A unique feature in mammalian erythropoiesis is the dramatic chromatin condensation followed by enucleation. This step-by-step process starts at the beginning of terminal erythropoiesis after the hematopoietic stem cells are committed to erythroid lineage. Although this phenomenon is known for decades, the mechanisms of chromatin condensation and enucleation remain elusive. Recent advances in cell and molecular biology have started to reveal the molecular pathways in the regulation of chromatin condensation, the establishment of nuclear polarity prior enucleation, and the rearrangement of actin cytoskeleton in enucleation. However, many challenging questions, especially whether and how the apoptotic mechanisms are involved in chromatin condensation and how to dissect the functions of many actin cytoskeleton proteins in cytokinesis and enucleation, remain to be answered. Here I review our current understanding of mammalian erythroid chromatin condensation and enucleation during terminal differentiation with a focus on more recent studies. I conclude with my perspective of future works in this rising topic in developmental and cell biology. Copyright © 2015 Elsevier Inc. All rights reserved.

Identification of human cell responses to benzene and benzene metabolites.

PubMed

Gillis, Bruce; Gavin, Igor M; Arbieva, Zarema; King, Stephen T; Jayaraman, Sundararajan; Prabhakar, Bellur S

2007-09-01

Benzene is a common air pollutant and confirmed carcinogen, especially in reference to the hematopoietic system. In the present study we analyzed cytokine/chemokine production by, and gene expression induction in, human peripheral blood mononuclear cells upon their exposure to the benzene metabolites catechol, hydroquinone, 1,2,4-benzenetriol, and p-benzoquinone. Protein profiling showed that benzene metabolites can stimulate the production of chemokines, the proinflammatory cytokines TNF-alpha and IL-6, and the Th2 cytokines IL-4 and IL-5. Activated cells showed concurrent suppression of anti-inflammatory cytokine IL-10 expression. We also identified changes in global gene expression patterns in response to benzene metabolite challenges by using high-density oligonucleotide microarrays. Treatment with 1,2,4-benzenetriol resulted in the suppression of genes related to the regulation of protein expression and a concomitant activation of genes that encode heat shock proteins and cytochrome P450 family members. Protein and gene expression profiling identified unique human cellular responses upon exposure to benzene and benzene metabolites.

Interleukin-3 plays dual roles in osteoclastogenesis by promoting the development of osteoclast progenitors but inhibiting the osteoclastogenic process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Huixian; Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294; Shi, Zhenqi

2013-11-01

Highlights: •IL-3 treatment of bone marrow cells generates a population of hematopoietic cells. •IL-3-dependent hematopoietic cells are capable of differentiating into osteoclasts. •Osteoclasts derived from IL-3-dependent hematopoietic cells are functional. •IL-3 promotes the development of osteoclast progenitors. •IL-3 inhibits the osteoclastogenic process. -- Abstract: Interleukin (IL)-3, a multilineage hematopoietic growth factor, is implicated in the regulation of osteoclastogenesis. However, the role of IL-3 in osteoclastogenesis remains controversial; whereas early studies showed that IL-3 stimulates osteoclastogenesis, recent investigations demonstrated that IL-3 inhibits osteoclast formation. The objective of this work is to further address the role of IL-3 in osteoclastogenesis. We foundmore » that IL-3 treatment of bone marrow cells generated a population of cells capable of differentiating into osteoclasts in tissue culture dishes in response to the stimulation of the monocyte/macrophage-colony stimulating factor (M-CSF) and the receptor activator of nuclear factor kappa B ligand (RANKL). The IL-3-dependent hematopoietic cells were able to further proliferate and differentiate in response to M-CSF stimulation and the resulting cells were also capable of forming osteoclasts with M-CSF and RANKL treatment. Interestingly, IL-3 inhibits M-CSF-/RANKL-induced differentiation of the IL-3-dependent hematopoietic cells into osteoclasts. The flow cytometry analysis indicates that while IL-3 treatment of bone marrow cells slightly affected the percentage of osteoclast precursors in the surviving populations, it considerably increased the percentage of osteoclast precursors in the populations after subsequent M-CSF treatment. Moreover, osteoclasts derived from IL-3-dependent hematopoietic cells were fully functional. Thus, we conclude that IL-3 plays dual roles in osteoclastogenesis by promoting the development of osteoclast progenitors but inhibiting the osteoclastogenic process. These findings provide a better understanding of the role of IL-3 in osteoclastogenesis.« less

The Adaptor Protein SAP Regulates Type II NKT Cell Development, Cytokine Production and Cytotoxicity Against Lymphoma1

PubMed Central

Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L.; Stein, Paul L.; Wang, Chyung-Ru

2014-01-01

CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule-associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT cell TCR transgenic mouse model (24αβTg), we demonstrated that CD1d-expressing hematopoietic cells but not thymic epithelial cells meditate efficient selection of type II NKT cells. Further, we showed that SAP regulates type II NKT cell development by controlling Egr2 and PLZF expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IRF4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. PMID:25236978

The adaptor protein SAP regulates type II NKT-cell development, cytokine production, and cytotoxicity against lymphoma.

PubMed

Weng, Xiufang; Liao, Chia-Min; Bagchi, Sreya; Cardell, Susanna L; Stein, Paul L; Wang, Chyung-Ru

2014-12-01

CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT-cell TCR transgenic mouse model, we demonstrated that CD1d-expressing hematopoietic cells, but not thymic epithelial cells, meditate efficient selection of type II NKT cells. Furthermore, we showed that SAP regulates type II NKT-cell development by controlling early growth response 2 protein and promyelocytic leukemia zinc finger expression. SAP-deficient 24αβ transgenic T cells (24αβ T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αβ T cells was associated with reduced IFN regulatory factor 4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Estrogen Regulates Bone Turnover by Targeting RANKL Expression in Bone Lining Cells.

PubMed

Streicher, Carmen; Heyny, Alexandra; Andrukhova, Olena; Haigl, Barbara; Slavic, Svetlana; Schüler, Christiane; Kollmann, Karoline; Kantner, Ingrid; Sexl, Veronika; Kleiter, Miriam; Hofbauer, Lorenz C; Kostenuik, Paul J; Erben, Reinhold G

2017-07-25

Estrogen is critical for skeletal homeostasis and regulates bone remodeling, in part, by modulating the expression of receptor activator of NF-κB ligand (RANKL), an essential cytokine for bone resorption by osteoclasts. RANKL can be produced by a variety of hematopoietic (e.g. T and B-cell) and mesenchymal (osteoblast lineage, chondrocyte) cell types. The cellular mechanisms by which estrogen acts on bone are still a matter of controversy. By using murine reconstitution models that allow for selective deletion of estrogen receptor-alpha (ERα) or selective inhibition of RANKL in hematopoietic vs. mesenchymal cells, in conjunction with in situ expression profiling in bone cells, we identified bone lining cells as important gatekeepers of estrogen-controlled bone resorption. Our data indicate that the increase in bone resorption observed in states of estrogen deficiency in mice is mainly caused by lack of ERα-mediated suppression of RANKL expression in bone lining cells.

MiR-17 Partly Promotes Hematopoietic Cell Expansion through Augmenting HIF-1α in Osteoblasts

PubMed Central

Yang, Yuxia; Ma, Wei; Wu, Dan; Huang, Yu; Li, Hongge; Zou, Junhua; Zhang, Yanju; Feng, Meifu; Luo, Jianyuan

2013-01-01

Background Hematopoietic stem cell (HSC) regulation is highly dependent on interactions with the marrow microenvironment, of which osteogenic cells play a crucial role. While evidence is accumulating for an important role of intrinsic miR-17 in regulating HSCs and HPCs, whether miR-17 signaling pathways are also necessary in the cell-extrinsic control of hematopoiesis hereto remains poorly understood. Methodology/Principal Findings Using the immortalized clone with the characteristics of osteoblasts, FBMOB-hTERT, in vitro expansion, long-term culture initiating cell (LTC-IC) and non-obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice repopulating cell (SRC) assay revealed that the ectopic expression of miR-17 partly promoted the ability of FBMOB-hTERT to support human cord blood (CB) CD34+ cell expansion and maintain their multipotency. It also seemed that osteoblastic miR-17 was prone to cause a specific expansion of the erythroid lineage. Conversely, deficient expression of miR-17 partly inhibited the hematopoietic supporting ability of FBMOB-hTERT. We further identified that HIF-1α is responsible for, at least in part, the promoted hematopoietic supporting ability of FBMOB-hTERT caused by miR-17. HIF-1α expression is markedly enhanced in miR-17 overexpressed FBMOB-hTERT upon interaction with CB CD34+ cells compared to other niche associated factors. More interestingly, the specific erythroid lineage expansion of CB CD34+ cells caused by osteoblastic miR-17 was abrogated by HIF-1α knock down. Conclusion/Significance Our data demonstrated that CB CD34+ cell expansion can be partly promoted by osteoblastic miR-17, and in particular, ectopic miR-17 can cause a specific expansion of the erythroid lineage through augmenting HIF-1α in osteoblasts. PMID:23936170

Loss of the Liver X Receptors Disrupts the Balance of Hematopoietic Populations, With Detrimental Effects on Endothelial Progenitor Cells.

PubMed

Rasheed, Adil; Tsai, Ricky; Cummins, Carolyn L

2018-05-08

The liver X receptors (LXRs; α/β) are nuclear receptors known to regulate cholesterol homeostasis and the production of select hematopoietic populations. The objective of this study was to determine the importance of LXRs and a high-fat high-cholesterol diet on global hematopoiesis, with special emphasis on endothelial progenitor cells (EPCs), a vasoreparative cell type that is derived from bone marrow hematopoietic stem cells. Wild-type and LXR double-knockout ( Lxr αβ -/- ) mice were fed a Western diet (WD) to increase plasma cholesterol levels. In WD-fed Lxr αβ -/- mice, flow cytometry and complete blood cell counts revealed that hematopoietic stem cells, a myeloid progenitor, and mature circulating myeloid cells were increased; EPC numbers were significantly decreased. Hematopoietic stem cells from WD-fed Lxr αβ -/- mice showed increased cholesterol content, along with increased myeloid colony formation compared with chow-fed mice. In contrast, EPCs from WD-fed Lxr αβ -/- mice also demonstrated increased cellular cholesterol content that was associated with greater expression of the endothelial lineage markers Cd144 and Vegfr2 , suggesting accelerated differentiation of the EPCs. Treatment of human umbilical vein endothelial cells with conditioned medium collected from these EPCs increased THP-1 monocyte adhesion. Increased monocyte adhesion to conditioned medium-treated endothelial cells was recapitulated with conditioned medium from Lxr αβ -/- EPCs treated with cholesterol ex vivo, suggesting cholesterol is the main component of the WD inducing EPC dysfunction. LXRs are crucial for maintaining the balance of hematopoietic cells in a hypercholesterolemic environment and for mitigating the negative effects of cholesterol on EPC differentiation/secretome changes that promote monocyte-endothelial adhesion. © 2018 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Oceans of opportunity: exploring vertebrate hematopoiesis in zebrafish.

PubMed

Carroll, Kelli J; North, Trista E

2014-08-01

Exploitation of the zebrafish model in hematology research has surged in recent years, becoming one of the most useful and tractable systems for understanding regulation of hematopoietic development, homeostasis, and malignancy. Despite the evolutionary distance between zebrafish and humans, remarkable genetic and phenotypic conservation in the hematopoietic system has enabled significant advancements in our understanding of blood stem and progenitor cell biology. The strengths of zebrafish in hematology research lie in the ability to perform real-time in vivo observations of hematopoietic stem, progenitor, and effector cell emergence, expansion, and function, as well as the ease with which novel genetic and chemical modifiers of specific hematopoietic processes or cell types can be identified and characterized. Further, myriad transgenic lines have been developed including fluorescent reporter systems to aid in the visualization and quantification of specified cell types of interest and cell-lineage relationships, as well as effector lines that can be used to implement a wide range of experimental manipulations. As our understanding of the complex nature of blood stem and progenitor cell biology during development, in response to infection or injury, or in the setting of hematologic malignancy continues to deepen, zebrafish will remain essential for exploring the spatiotemporal organization and integration of these fundamental processes, as well as the identification of efficacious small molecule modifiers of hematopoietic activity. In this review, we discuss the biology of the zebrafish hematopoietic system, including similarities and differences from mammals, and highlight important tools currently utilized in zebrafish embryos and adults to enhance our understanding of vertebrate hematology, with emphasis on findings that have impacted our understanding of the onset or treatment of human hematologic disorders and disease. Copyright © 2014 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice

PubMed Central

Otten, Jeroen J. T.; de Jager, Saskia C. A.; Kavelaars, Annemieke; Seijkens, Tom; Bot, Ilze; Wijnands, Erwin; Beckers, Linda; Westra, Marijke M.; Bot, Martine; Busch, Matthias; Bermudez, Beatriz; van Berkel, Theo J. C.; Heijnen, Cobi J.; Biessen, Erik A. L.

2013-01-01

Leukocyte chemotaxis is deemed instrumental in initiation and progression of atherosclerosis. It is mediated by G-protein-coupled receptors (e.g., CCR2 and CCR5), the activity of which is controlled by G-protein-coupled receptor kinases (GRKs). In this study, we analyzed the effect of hematopoietic deficiency of a potent regulator kinase of chemotaxis (GRK2) on atherogenesis. LDL receptor-deficient (LDLr−/−) mice with heterozygous hematopoietic GRK2 deficiency, generated by bone marrow transplantation (n=15), displayed a dramatic attenuation of plaque development, with 79% reduction in necrotic core and increased macrophage content. Circulating monocytes decreased and granulocytes increased in GRK2+/− chimeras, which could be attributed to diminished granulocyte colony-forming units in bone marrow. Collectively, these data pointed to myeloid cells as major mediators of the impaired atherogenic response in GRK2+/− chimeras. LDLr−/− mice with macrophage/granulocyte-specific GRK2 deficiency (LysM-Cre GRK2flox/flox; n=8) failed to mimic the aforementioned phenotype, acquitting these cells as major responsible subsets for GRK2 deficiency-associated atheroprotection. To conclude, even partial hematopoietic GRK2 deficiency prevents atherosclerotic lesion progression beyond the fatty streak stage, identifying hematopoietic GRK2 as a potential target for intervention in atherosclerosis.—Otten, J. J. T., de Jager, S. C. A., Kavelaars, A., Seijkens, T., Bot, I., Wijnands, E., Beckers, L., Westra, M. M., Bot, M., Busch, M., Bermudez, B., van Berkel, T. J. C., Heijnen, C. J., Biessen, E. A. L. Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice. PMID:23047899

Oceans of Opportunity: Exploring Vertebrate Hematopoiesis in Zebrafish

PubMed Central

Carroll, Kelli J.; North, Trista E.

2015-01-01

Exploitation of the zebrafish model in hematology research has surged in recent years, becoming one of the most useful and tractable systems for understanding regulation of hematopoietic development, homeostasis, and malignancy. Despite the evolutionary distance between zebrafish and humans, remarkable genetic and phenotypic conservation in the hematopoietic system has enabled significant advancements in our understanding of blood stem and progenitor cell (HSPC) biology. The strengths of zebrafish in hematology research lie in the ability to perform real-time in vivo observations of hematopoietic stem, progenitor and effector cell emergence, expansion and function, as well as the ease with which novel genetic and chemical modifiers of specific hematopoietic processes or cell-types can be identified and characterized. Further, a myriad of transgenic lines have been developed including fluorescent reporter systems to aid in the visualization and quantification of specified cell types of interest and cell-lineage relationships, as well as effector lines that can be used to implement a wide range of experimental manipulations. As our understanding of the complex nature of HSPC biology during development, in response to infection or injury, or in the setting of hematological malignancy, continues to deepen, zebrafish will remain essential for exploring the spatio-temporal organization and integration of these fundamental processes, as well as the identification of efficacious small molecule modifiers of hematopoietic activity. In this review, we discuss the biology of the zebrafish hematopoietic system, including similarities and differences from mammals, and highlight important tools currently utilized in zebrafish embryos and adults to enhance our understanding of vertebrate hematology, with emphasis on findings that have impacted our understanding of the onset or treatment of human hematologic disorders and disease. PMID:24816275

Tamm-Horsfall Protein Regulates Granulopoiesis and Systemic Neutrophil Homeostasis

PubMed Central

Micanovic, Radmila; Chitteti, Brahmananda R.; Dagher, Pierre C.; Srour, Edward F.; Khan, Shehnaz; Hato, Takashi; Lyle, Allison; Tong, Yan; Wu, Xue-Ru

2015-01-01

Tamm-Horsfall protein (THP) is a glycoprotein uniquely expressed in the kidney. We recently showed an important role for THP in mediating tubular cross-talk in the outer medulla and in suppressing neutrophil infiltration after kidney injury. However, it remains unclear whether THP has a broader role in neutrophil homeostasis. In this study, we show that THP deficiency in mice increases the number of neutrophils, not only in the kidney but also in the circulation and in the liver, through enhanced granulopoiesis in the bone marrow. Using multiplex ELISA, we identified IL-17 as a key granulopoietic cytokine specifically upregulated in the kidneys but not in the liver of THP−/− mice. Indeed, neutralization of IL-17 in THP−/− mice completely reversed the systemic neutrophilia. Furthermore, IL-23 was also elevated in THP−/− kidneys. We performed real-time PCR on laser microdissected tubular segments and FACS-sorted renal immune cells and identified the S3 proximal segments, but not renal macrophages, as a major source of increased IL-23 synthesis. In conclusion, we show that THP deficiency stimulates proximal epithelial activation of the IL-23/IL-17 axis and systemic neutrophilia. Our findings provide evidence that the kidney epithelium in the outer medulla can regulate granulopoiesis. When this novel function is added to its known role in erythropoiesis, the kidney emerges as an important regulator of the hematopoietic system. PMID:25556169

Physiological Jak2V617F expression causes a lethal myeloproliferative neoplasm with differential effects on hematopoietic stem and progenitor cells.

PubMed

Mullally, Ann; Lane, Steven W; Ball, Brian; Megerdichian, Christine; Okabe, Rachel; Al-Shahrour, Fatima; Paktinat, Mahnaz; Haydu, J Erika; Housman, Elizabeth; Lord, Allegra M; Wernig, Gerlinde; Kharas, Michael G; Mercher, Thomas; Kutok, Jeffery L; Gilliland, D Gary; Ebert, Benjamin L

2010-06-15

We report a Jak2V617F knockin mouse myeloproliferative neoplasm (MPN) model resembling human polycythemia vera (PV). The MPN is serially transplantable and we demonstrate that the hematopoietic stem cell (HSC) compartment has the unique capacity for disease initiation but does not have a significant selective competitive advantage over wild-type HSCs. In contrast, myeloid progenitor populations are expanded and skewed toward the erythroid lineage, but cannot transplant the disease. Treatment with a JAK2 kinase inhibitor ameliorated the MPN phenotype, but did not eliminate the disease-initiating population. These findings provide insights into the consequences of JAK2 activation on HSC differentiation and function and have the potential to inform therapeutic approaches to JAK2V617F-positive MPN. Copyright 2010 Elsevier Inc. All rights reserved.

Vitamin C: C-ing a New Way to Fight Leukemia.

PubMed

Schönberger, Katharina; Cabezas-Wallscheid, Nina

2017-11-02

Metabolic cues and (epi-)genetic factors are emerging regulators of hematopoietic stem cell (HSC) potency. Two new studies in Nature and Cell, from Agathocleous et al. (2017) and Cimmino et al. (2017), respectively, show that vitamin C regulates HSC function and suppresses leukemogenesis by modulating Tet2 activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Ott1 (Rbm15) regulates thrombopoietin response in hematopoietic stem cells through alternative splicing of c-Mpl.

PubMed

Xiao, Nan; Laha, Suparna; Das, Shankar P; Morlock, Kayla; Jesneck, Jonathan L; Raffel, Glen D

2015-02-05

Thrombopoietin (Thpo) signaling through the c-Mpl receptor promotes either quiescence or proliferation of hematopoietic stem cells (HSCs) in a concentration-dependent manner; however, in vivo Thpo serum levels are responsive to platelet mass rather than HSC demands, suggesting additional regulation exists. Ott1 (Rbm15), a spliceosomal component originally identified as a fusion partner in t(1;22)-associated acute megakaryocytic leukemia, is also essential for maintaining HSC quiescence under stress. Ott1 controls the alternative splicing of a dominant negative isoform, Mpl-TR, capable of inhibiting HSC engraftment and attenuating Thpo signaling. Ott1, which associates with Hdac3 and the histone methyltransferase, Setd1b, binds to both c-Mpl RNA and chromatin and regulates H4 acetylation and H3K4me3 marks. Histone deacetylase or histone methyltransferase inhibition also increases Mpl-TR levels, suggesting that Ott1 uses an underlying epigenetic mechanism to control alternative splicing of c-Mpl. Manipulation of Ott1-dependent alternative splicing may therefore provide a novel pharmacologic avenue for regulating HSC quiescence and proliferation in response to Thpo. © 2015 by The American Society of Hematology.

miR-99 regulates normal and malignant hematopoietic stem cell self-renewal.

PubMed

Khalaj, Mona; Woolthuis, Carolien M; Hu, Wenhuo; Durham, Benjamin H; Chu, S Haihua; Qamar, Sarah; Armstrong, Scott A; Park, Christopher Y

2017-07-21

The microRNA-99 ( miR-99 ) family comprises a group of broadly conserved microRNAs that are highly expressed in hematopoietic stem cells (HSCs) and acute myeloid leukemia stem cells (LSCs) compared with their differentiated progeny. Herein, we show that miR-99 regulates self-renewal in both HSCs and LSCs. miR-99 maintains HSC long-term reconstitution activity by inhibiting differentiation and cell cycle entry. Moreover, miR-99 inhibition induced LSC differentiation and depletion in an MLL-AF9-driven mouse model of AML, leading to reduction in leukemia-initiating activity and improved survival in secondary transplants. Confirming miR-99 's role in established AML, miR-99 inhibition induced primary AML patient blasts to undergo differentiation. A forward genetic shRNA library screen revealed Hoxa1 as a critical mediator of miR-99 function in HSC maintenance, and this observation was independently confirmed in both HSCs and LSCs. Together, these studies demonstrate the importance of noncoding RNAs in the regulation of HSC and LSC function and identify miR-99 as a critical regulator of stem cell self-renewal. © 2017 Khalaj et al.

miR-99 regulates normal and malignant hematopoietic stem cell self-renewal

PubMed Central

Khalaj, Mona; Woolthuis, Carolien M.; Hu, Wenhuo; Durham, Benjamin H.; Chu, S. Haihua; Qamar, Sarah; Armstrong, Scott A.

2017-01-01

The microRNA-99 (miR-99) family comprises a group of broadly conserved microRNAs that are highly expressed in hematopoietic stem cells (HSCs) and acute myeloid leukemia stem cells (LSCs) compared with their differentiated progeny. Herein, we show that miR-99 regulates self-renewal in both HSCs and LSCs. miR-99 maintains HSC long-term reconstitution activity by inhibiting differentiation and cell cycle entry. Moreover, miR-99 inhibition induced LSC differentiation and depletion in an MLL-AF9–driven mouse model of AML, leading to reduction in leukemia-initiating activity and improved survival in secondary transplants. Confirming miR-99’s role in established AML, miR-99 inhibition induced primary AML patient blasts to undergo differentiation. A forward genetic shRNA library screen revealed Hoxa1 as a critical mediator of miR-99 function in HSC maintenance, and this observation was independently confirmed in both HSCs and LSCs. Together, these studies demonstrate the importance of noncoding RNAs in the regulation of HSC and LSC function and identify miR-99 as a critical regulator of stem cell self-renewal. PMID:28733386

Hematopoietic Stem Cells: Transcriptional Regulation, Ex Vivo Expansion and Clinical Application

PubMed Central

Aggarwal, R.; Lu, J.; Pompili, V.J.; Das, H.

2012-01-01

Maintenance of ex vivo hematopoietic stem cells (HSC) pool and its differentiated progeny is regulated by complex network of transcriptional factors, cell cycle proteins, extracellular matrix, and their microenvironment through an orchestrated fashion. Strides have been made to understand the mechanisms regulating in vivo quiescence and proliferation of HSCs to develop strategies for ex vivo expansion. Ex vivo expansion of HSCs is important to procure sufficient number of stem cells and as easily available source for HSC transplants for patients suffering from hematological disorders and malignancies. Our lab has established a nanofiber-based ex vivo expansion strategy for HSCs, while preserving their stem cell characteristics. Ex vivo expanded cells were also found biologically functional in various disease models. However, the therapeutic potential of expanded stem cells at clinical level still needs to be verified. This review outlines transcriptional factors that regulate development of HSCs and their commitment, genes that regulate cell cycle status, studies that attempt to develop an effective and efficient protocol for ex vivo expansion of HSCs and application of HSC in various non-malignant and malignant disorders. Overall the goal of the current review is to deliver an understanding of factors that are critical in resolving the challenges that limit the expansion of HSCs in vivo and ex vivo. PMID:22082480

A Unique Opportunity To Test Whether Cell Fusion Is a Mechanism of Breast Cancer Metastasis

DTIC Science & Technology

2016-08-01

mesenchymal stem cells are a potent fusion partner for breast cancer cells ...and hematopoietic stem cells were enriched. In addition, human mesenchymal stem cells were obtained from bone marrow. 2   Table 1...adherent cell types – mesenchymal stem cells and epithelial cell types. Thus, MSCs were mixed with each epithelial cell type  (i.e. MSCs with

Bone marrow osteoblast vulnerability to chemotherapy

PubMed Central

Gencheva, Marieta; Hare, Ian; Kurian, Susan; Fortney, Jim; Piktel, Debbie; Wysolmerski, Robert; Gibson, Laura F.

2013-01-01

Osteoblasts are a major component of the bone marrow microenvironment which provide support for hematopoietic cell development. Functional disruption of any element of the bone marrow niche, including osteoblasts, can potentially impair hematopoiesis. We have studied the effect of two widely used drugs with different mechanisms of action, etoposide (VP16) and melphalan, on murine osteoblasts at distinct stages of maturation. VP16 and melphalan delayed maturation of preosteoblasts and altered CXCL12 protein levels, a key regulator of hematopoietic cell homing to the bone marrow. Sublethal concentrations of VP16 and melphalan also decreased the levels of several transcripts which contribute to the composition of the extracellular matrix (ECM) including osteopontin (OPN), osteocalcin (OCN) and collagen 1A1 (Col1a1). The impact of chemotherapy on message and protein levels for some targets was not always aligned, suggesting differential responses at the transcription and translation or protein stability levels. Since one of the main functions of a mature osteoblast is to synthesize ECM of a defined composition, disruption of the ratio of its components may be one mechanism by which chemotherapy affects the ability of osteoblasts to support hematopoietic recovery coincident with altered marrow architecture. Collectively, these observations suggest that the osteoblast compartment of the marrow hematopoietic niche is vulnerable to functional dysregulation by damage imposed by agents frequently used in clinical settings. Understanding the mechanistic underpinning of chemotherapy-induced changes on the hematopoietic support capacity of the marrow microenvironment may contribute to improved strategies to optimize patient recovery post-transplantation. PMID:23551534

Short Stat5-Interacting Peptide Derived from Phospholipase C-β3 Inhibits Hematopoietic Cell Proliferation and Myeloid Differentiation

PubMed Central

Yasudo, Hiroki; Ando, Tomoaki; Xiao, Wenbin; Kawakami, Yuko; Kawakami, Toshiaki

2011-01-01

Constitutive activation of the transcription factor Stat5 in hematopoietic stem/progenitor cells leads to various hematopoietic malignancies including myeloproliferative neoplasm (MPN). Our recent study found that phospholipase C (PLC)-β3 is a novel tumor suppressor involved in MPN, lymphoma and other tumors. Stat5 activity is negatively regulated by the SH2 domain-containing protein phosphatase SHP-1 in a PLC-β3-dependent manner. PLC-β3 can form the multimolecular SPS complex together with SHP-1 and Stat5. The close physical proximity of SHP-1 and Stat5 brought about by interacting with the C-terminal segment of PLC-β3 (PLC-β3-CT) accelerates SHP-1-mediated dephosphorylation of Stat5. Here we identify the minimal sequences within PLC-β3-CT required for its tumor suppressor function. Two of the three Stat5-binding noncontiguous regions, one of which also binds SHP-1, substantially inhibited in vitro proliferation of Ba/F3 cells. Surprisingly, an 11-residue Stat5-binding peptide (residues 988-998) suppressed Stat5 activity in Ba/F3 cells and in vivo proliferation and myeloid differentiation of hematopoietic stem/progenitor cells. Therefore, this study further defines PLC-β3-CT as the Stat5- and SHP-1-binding domain by identifying minimal functional sequences of PLC-β3 for its tumor suppressor function and implies their potential utility in the control of hematopoietic malignancies. PMID:21949826

Sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells in mice

PubMed Central

Guo, Chang-Ying; Luo, Lan; Urata, Yoshishige; Goto, Shinji; Huang, Wen-Jing; Takamura, Syu; Hayashi, Fumiko; Doi, Hanako; Kitajima, Yuriko; Ono, Yusuke; Ogi, Tomoo; Li, Tao-Sheng

2015-01-01

We evaluated the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells. Adult C57BL/6 mice were daily exposed to 0, 2, 10, 50, and 250 mGy γ-ray for 1 month in succession, respectively. The damage of hematopoietic stem/progenitor cells in bone marrow were investigated within 2 hours (acute phase) or at 3 months (chronic phase) after the last exposure. Daily exposure to over 10 mGy γ-ray significantly decreased the number and colony-forming capacity of hematopoietic stem/progenitor cells at acute phase, and did not completely recover at chronic phase with 250 mGy exposure. Interestingly, the daily exposure to 10 or 50 mGy γ-ray decreased the formation of mixed types of colonies at chronic phase, but the total number of colonies was comparable to control. Immunostaining analysis showed that the formation of 53BP1 foci in c-kit+ stem/progenitor cells was significantly increased with daily exposure to 50 and 250 mGy at acute phase, and 250 mGy at chronic phase. Many genes involved in toxicity responses were up- or down-regulated with the exposures to all doses. Our data have clearly shown the sensitivity and dose dependency of radiation-induced injury in hematopoietic stem/progenitor cells of mice with daily exposures to 2 ~ 250 mGy γ-ray. PMID:25623887

Pim1 kinase regulates c-Kit gene translation.

PubMed

An, Ningfei; Cen, Bo; Cai, Houjian; Song, Jin H; Kraft, Andrew; Kang, Yubin

2016-01-01

Receptor tyrosine kinase, c-Kit (CD117) plays a pivotal role in the maintenance and expansion of hematopoietic stem/progenitor cells (HSPCs). Additionally, over-expression and/or mutational activation of c-Kit have been implicated in numerous malignant diseases including acute myeloid leukemia. However, the translational regulation of c-Kit expression remains largely unknown. We demonstrated that loss of Pim1 led to specific down-regulation of c-Kit expression in HSPCs of Pim1 -/- mice and Pim1 -/- 2 -/- 3 -/- triple knockout (TKO) mice, and resulted in attenuated ERK and STAT3 signaling in response to stimulation with stem cell factor. Transduction of c-Kit restored the defects in colony forming capacity seen in HSPCs from Pim1 -/- and TKO mice. Pharmacologic inhibition and genetic modification studies using human megakaryoblastic leukemia cells confirmed the regulation of c-Kit expression by Pim1 kinase: i.e., Pim1-specific shRNA knockdown down-regulated the expression of c-Kit whereas overexpression of Pim1 up-regulated the expression of c-Kit. Mechanistically, inhibition or knockout of Pim1 kinase did not affect the transcription of c-Kit gene. Pim1 kinase enhanced c-Kit 35 S methionine labeling and increased the incorporation of c-Kit mRNAs into the polysomes and monosomes, demonstrating that Pim1 kinase regulates c-Kit expression at the translational level. Our study provides the first evidence that Pim1 regulates c-Kit gene translation and has important implications in hematopoietic stem cell transplantation and cancer treatment.

BLOS2 negatively regulates Notch signaling during neural and hematopoietic stem and progenitor cell development

PubMed Central

Zhou, Wenwen; He, Qiuping; Zhang, Chunxia; He, Xin; Cui, Zongbin; Liu, Feng; Li, Wei

2016-01-01

Notch signaling plays a crucial role in controling the proliferation and differentiation of stem and progenitor cells during embryogenesis or organogenesis, but its regulation is incompletely understood. BLOS2, encoded by the Bloc1s2 gene, is a shared subunit of two lysosomal trafficking complexes, biogenesis of lysosome-related organelles complex-1 (BLOC-1) and BLOC-1-related complex (BORC). Bloc1s2−/− mice were embryonic lethal and exhibited defects in cortical development and hematopoiesis. Loss of BLOS2 resulted in elevated Notch signaling, which consequently increased the proliferation of neural progenitor cells and inhibited neuronal differentiation in cortices. Likewise, ablation of bloc1s2 in zebrafish or mice led to increased hematopoietic stem and progenitor cell production in the aorta-gonad-mesonephros region. BLOS2 physically interacted with Notch1 in endo-lysosomal trafficking of Notch1. Our findings suggest that BLOS2 is a novel negative player in regulating Notch signaling through lysosomal trafficking to control multiple stem and progenitor cell homeostasis in vertebrates. DOI: http://dx.doi.org/10.7554/eLife.18108.001 PMID:27719760

Regulation of myeloproliferation and M2 macrophage programming in mice by Lyn/Hck, SHIP, and Stat5

PubMed Central

Xiao, Wenbin; Hong, Hong; Kawakami, Yuko; Lowell, Clifford A.; Kawakami, Toshiaki

2008-01-01

The proliferation and differentiation of hematopoietic stem cells (HSCs) is finely regulated by extrinsic and intrinsic factors via various signaling pathways. Here we have shown that, similar to mice deficient in the lipid phosphatase SHIP, loss of 2 Src family kinases, Lyn and Hck, profoundly affects HSC differentiation, producing hematopoietic progenitors with increased proliferation, reduced apoptosis, growth factor–independent survival, and skewed differentiation toward M2 macrophages. This phenotype culminates in a Stat5-dependent myeloproliferative disease that is accompanied by M2 macrophage infiltration of the lung. Expression of a membrane-bound form of SHIP in HSCs lacking both Lyn and Hck restored normal hematopoiesis and prevented myeloproliferation. In vitro and in vivo studies suggested the involvement of autocrine and/or paracrine production of IL-3 and GM-CSF in the increased proliferation and myeloid differentiation of HSCs. Thus, this study has defined a myeloproliferative transformation-sensitive signaling pathway, composed of Lyn/Hck, SHIP, autocrine/paracrine cytokines, and Stat5, that regulates HSC differentiation and M2 macrophage programming. PMID:18246197

MED12 Regulates HSC-Specific Enhancers Independently of Mediator Kinase Activity to Control Hematopoiesis.

PubMed

Aranda-Orgilles, Beatriz; Saldaña-Meyer, Ricardo; Wang, Eric; Trompouki, Eirini; Fassl, Anne; Lau, Stephanie; Mullenders, Jasper; Rocha, Pedro P; Raviram, Ramya; Guillamot, María; Sánchez-Díaz, María; Wang, Kun; Kayembe, Clarisse; Zhang, Nan; Amoasii, Leonela; Choudhuri, Avik; Skok, Jane A; Schober, Markus; Reinberg, Danny; Sicinski, Piotr; Schrewe, Heinrich; Tsirigos, Aristotelis; Zon, Leonard I; Aifantis, Iannis

2016-12-01

Hematopoietic-specific transcription factors require coactivators to communicate with the general transcription machinery and establish transcriptional programs that maintain hematopoietic stem cell (HSC) self-renewal, promote differentiation, and prevent malignant transformation. Mediator is a large coactivator complex that bridges enhancer-localized transcription factors with promoters, but little is known about Mediator function in adult stem cell self-renewal and differentiation. We show that MED12, a member of the Mediator kinase module, is an essential regulator of HSC homeostasis, as in vivo deletion of Med12 causes rapid bone marrow aplasia leading to acute lethality. Deleting other members of the Mediator kinase module does not affect HSC function, suggesting kinase-independent roles of MED12. MED12 deletion destabilizes P300 binding at lineage-specific enhancers, resulting in H3K27Ac depletion, enhancer de-activation, and consequent loss of HSC stemness signatures. As MED12 mutations have been described recently in blood malignancies, alterations in MED12-dependent enhancer regulation may control both physiological and malignant hematopoiesis. Copyright © 2016 Elsevier Inc. All rights reserved.

R-spondin 1 is required for specification of hematopoietic stem cells through Wnt16 and Vegfa signaling pathways

PubMed Central

2017-01-01

Hematopoietic stem cells (HSCs) are the therapeutic component of bone marrow transplants, but finding immune-compatible donors limits treatment availability and efficacy. Recapitulation of endogenous specification during development is a promising approach to directing HSC specification in vitro, but current protocols are not capable of generating authentic HSCs with high efficiency. Across phyla, HSCs arise from hemogenic endothelium in the ventral floor of the dorsal aorta concurrent with arteriovenous specification and intersegmental vessel (ISV) sprouting, processes regulated by Notch and Wnt. We hypothesized that coordination of HSC specification with vessel patterning might involve modulatory regulatory factors such as R-spondin 1 (Rspo1), an extracellular protein that enhances β-catenin-dependent Wnt signaling and has previously been shown to regulate ISV patterning. We find that Rspo1 is required for HSC specification through control of parallel signaling pathways controlling HSC specification: Wnt16/DeltaC/DeltaD and Vegfa/Tgfβ1. Our results define Rspo1 as a key upstream regulator of two crucial pathways necessary for HSC specification. PMID:28087636

Efforts to enhance blood stem cell engraftment: Recent insights from zebrafish hematopoiesis

PubMed Central

Perlin, Julie R.; Robertson, Anne L.

2017-01-01

Hematopoietic stem cell transplantation (HSCT) is an important therapy for patients with a variety of hematological malignancies. HSCT would be greatly improved if patient-specific hematopoietic stem cells (HSCs) could be generated from induced pluripotent stem cells in vitro. There is an incomplete understanding of the genes and signals involved in HSC induction, migration, maintenance, and niche engraftment. Recent studies in zebrafish have revealed novel genes that are required for HSC induction and niche regulation of HSC homeostasis. Manipulation of these signaling pathways and cell types may improve HSC bioengineering, which could significantly advance critical, lifesaving HSCT therapies. PMID:28830909

Endothelial Barrier and Metabolism: New Kids on the Block Regulating Bone Marrow Vascular Niches.

PubMed

Harjes, Ulrike; Verfaillie, Catherine; Carmeliet, Peter

2016-05-09

The vasculature of the bone marrow remains poorly characterized, yet crucial to maintain hematopoiesis and retain stem cells in a quiescent state. A recent study by Itkin et al. (2016) in Nature reports how vascular barrier integrity and endothelial cell metabolism regulate hematopoietic stem cell quiescence and leukocyte trafficking. Copyright © 2016 Elsevier Inc. All rights reserved.

Progressive alterations in multipotent hematopoietic progenitors underlie lymphoid cell loss in aging.

PubMed

Young, Kira; Borikar, Sneha; Bell, Rebecca; Kuffler, Lauren; Philip, Vivek; Trowbridge, Jennifer J

2016-10-17

Declining immune function with age is associated with reduced lymphoid output of hematopoietic stem cells (HSCs). Currently, there is poor understanding of changes with age in the heterogeneous multipotent progenitor (MPP) cell compartment, which is long lived and responsible for dynamically regulating output of mature hematopoietic cells. In this study, we observe an early and progressive loss of lymphoid-primed MPP cells (LMPP/MPP4) with aging, concomitant with expansion of HSCs. Transcriptome and in vitro functional analyses at the single-cell level reveal a concurrent increase in cycling of aging LMPP/MPP4 with loss of lymphoid priming and differentiation potential. Impaired lymphoid differentiation potential of aged LMPP/MPP4 is not rescued by transplantation into a young bone marrow microenvironment, demonstrating cell-autonomous changes in the MPP compartment with aging. These results pinpoint an age and cellular compartment to focus further interrogation of the drivers of lymphoid cell loss with aging. © 2016 Young et al.

Restricted intra-embryonic origin of bona fide hematopoietic stem cells in the chicken

PubMed Central

Yvernogeau, Laurent

2017-01-01

Hematopoietic stem cells (HSCs), which are responsible for blood cell production, are generated during embryonic development. Human and chicken embryos share features that position the chicken as a reliable and accessible alternative model to study developmental hematopoiesis. However, the existence of HSCs has never been formally proven in chicken embryos. Here, we have established a complete cartography and quantification of hematopoietic cells in the aorta during development. We demonstrate the existence of bona fide HSCs, originating from the chicken embryo aorta (and not the yolk sac, allantois or head), through an in vivo transplantation assay. Embryos transplanted in ovo with GFP embryonic tissues on the chorio-allantoic membrane provided multilineage reconstitution in adulthood. Historically, most breakthrough discoveries in the field of developmental hematopoiesis were first made in birds and later extended to mammals. Our study sheds new light on the avian model as a valuable system to study HSC production and regulation in vivo. PMID:28526756

Donor parity no longer a barrier for female-to-male hematopoietic stem cell transplantation.

PubMed

van Halteren, Astrid G S; Dierselhuis, Miranda P; Netelenbos, Tanja; Fechter, Mirjam

2014-01-01

Allogeneic hematopoietic stem cell transplantation (HSCT) is a widely applied treatment for disorders mainly involving the hematopoietic system. The success of this treatment depends on many different patient- and donor-specific factors. Based on higher CD34+ yields and superior clinical outcomes associated with the use of male donors, males are generally seen as the preferred HSCT donor. In addition, female donors are notorious for bearing memory type lymphocytes induced by previous pregnancies; such alloimmune cells may provoke unwanted immune reactions such as graft-vs.-host disease in transplant recipients. Consequently, many transplant centers try to avoid parous donors, particularly when searching the best unrelated donor for a male patient. We recently showed that parous women with female offspring have an anti-male directed tolerogenic immune status comparable to that of nulliparous donors. As discussed in this article addendum, the sex of the donor's offspring combined with the presence of HY-specific T regulator cells are possibly better selection criteria than parity status per se.

Drosophila sessile hemocyte clusters are true hematopoietic tissues that regulate larval blood cell differentiation

PubMed Central

Leitão, Alexandre B; Sucena, Élio

2015-01-01

Virtually all species of coelomate animals contain blood cells that display a division of labor necessary for homeostasis. This functional partition depends upon the balance between proliferation and differentiation mostly accomplished in the hematopoietic organs. In Drosophila melanogaster, the lymph gland produces plasmatocytes and crystal cells that are not released until pupariation. Yet, throughout larval development, both hemocyte types increase in numbers. Mature plasmatocytes can proliferate but it is not known if crystal cell numbers increase by self-renewal or by de novo differentiation. We show that new crystal cells in third instar larvae originate through a Notch-dependent process of plasmatocyte transdifferentiation. This process occurs in the sessile clusters and is contingent upon the integrity of these structures. The existence of this hematopoietic tissue, relying on structure-dependent signaling events to promote blood homeostasis, creates a new paradigm for addressing outstanding questions in Drosophila hematopoiesis and establishing further parallels with vertebrate systems. DOI: http://dx.doi.org/10.7554/eLife.06166.001 PMID:25650737

Single-Cell RNA-Sequencing Reveals a Continuous Spectrum of Differentiation in Hematopoietic Cells.

PubMed

Macaulay, Iain C; Svensson, Valentine; Labalette, Charlotte; Ferreira, Lauren; Hamey, Fiona; Voet, Thierry; Teichmann, Sarah A; Cvejic, Ana

2016-02-02

The transcriptional programs that govern hematopoiesis have been investigated primarily by population-level analysis of hematopoietic stem and progenitor cells, which cannot reveal the continuous nature of the differentiation process. Here we applied single-cell RNA-sequencing to a population of hematopoietic cells in zebrafish as they undergo thrombocyte lineage commitment. By reconstructing their developmental chronology computationally, we were able to place each cell along a continuum from stem cell to mature cell, refining the traditional lineage tree. The progression of cells along this continuum is characterized by a highly coordinated transcriptional program, displaying simultaneous suppression of genes involved in cell proliferation and ribosomal biogenesis as the expression of lineage specific genes increases. Within this program, there is substantial heterogeneity in the expression of the key lineage regulators. Overall, the total number of genes expressed, as well as the total mRNA content of the cell, decreases as the cells undergo lineage commitment. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Distinguishing autocrine and paracrine signals in hematopoietic stem cell culture using a biofunctional microcavity platform

NASA Astrophysics Data System (ADS)

Müller, Eike; Wang, Weijia; Qiao, Wenlian; Bornhäuser, Martin; Zandstra, Peter W.; Werner, Carsten; Pompe, Tilo

2016-08-01

Homeostasis of hematopoietic stem cells (HSC) in the mammalian bone marrow stem cell niche is regulated by signals of the local microenvironment. Besides juxtacrine, endocrine and metabolic cues, paracrine and autocrine signals are involved in controlling quiescence, proliferation and differentiation of HSC with strong implications on expansion and differentiation ex vivo as well as in vivo transplantation. Towards this aim, a cell culture analysis on a polymer microcavity carrier platform was combined with a partial least square analysis of a mechanistic model of cell proliferation. We could demonstrate the discrimination of specific autocrine and paracrine signals from soluble factors as stimulating and inhibitory effectors in hematopoietic stem and progenitor cell culture. From that we hypothesize autocrine signals to be predominantly involved in maintaining the quiescent state of HSC in single-cell niches and advocate our analysis platform as an unprecedented option for untangling convoluted signaling mechanisms in complex cell systems being it of juxtacrine, paracrine or autocrine origin.

Prolonged fasting reduces IGF-1/PKA to promote hematopoietic-stem-cell-based regeneration and reverse immunosuppression.

PubMed

Cheng, Chia-Wei; Adams, Gregor B; Perin, Laura; Wei, Min; Zhou, Xiaoying; Lam, Ben S; Da Sacco, Stefano; Mirisola, Mario; Quinn, David I; Dorff, Tanya B; Kopchick, John J; Longo, Valter D

2014-06-05

Immune system defects are at the center of aging and a range of diseases. Here, we show that prolonged fasting reduces circulating IGF-1 levels and PKA activity in various cell populations, leading to signal transduction changes in long-term hematopoietic stem cells (LT-HSCs) and niche cells that promote stress resistance, self-renewal, and lineage-balanced regeneration. Multiple cycles of fasting abated the immunosuppression and mortality caused by chemotherapy and reversed age-dependent myeloid-bias in mice, in agreement with preliminary data on the protection of lymphocytes from chemotoxicity in fasting patients. The proregenerative effects of fasting on stem cells were recapitulated by deficiencies in either IGF-1 or PKA and blunted by exogenous IGF-1. These findings link the reduced levels of IGF-1 caused by fasting to PKA signaling and establish their crucial role in regulating hematopoietic stem cell protection, self-renewal, and regeneration. Copyright © 2014 Elsevier Inc. All rights reserved.

Coordinated transcriptional regulation of bone homeostasis by Ebf1 and Zfp521 in both mesenchymal and hematopoietic lineages

PubMed Central

Kiviranta, Riku; Yamana, Kei; Saito, Hiroaki; Ho, Daniel K.; Laine, Julius; Tarkkonen, Kati; Nieminen-Pihala, Vappu; Hesse, Eric; Correa, Diego; Määttä, Jorma; Tessarollo, Lino; Rosen, Evan D.; Horne, William C.; Jenkins, Nancy A.; Copeland, Neal G.; Warming, Soren

2013-01-01

Bone homeostasis is maintained by the coupled actions of hematopoietic bone-resorbing osteoclasts (OCs) and mesenchymal bone-forming osteoblasts (OBs). Here we identify early B cell factor 1 (Ebf1) and the transcriptional coregulator Zfp521 as components of the machinery that regulates bone homeostasis through coordinated effects in both lineages. Deletion of Zfp521 in OBs led to impaired bone formation and increased OB-dependent osteoclastogenesis (OC-genesis), and deletion in hematopoietic cells revealed a strong cell-autonomous role for Zfp521 in OC progenitors. In adult mice, the effects of Zfp521 were largely caused by repression of Ebf1, and the bone phenotype of Zfp521+/− mice was rescued in Zfp521+/−:Ebf1+/− mice. Zfp521 interacted with Ebf1 and repressed its transcriptional activity. Accordingly, deletion of Zfp521 led to increased Ebf1 activity in OBs and OCs. In vivo, Ebf1 overexpression in OBs resulted in suppressed bone formation, similar to the phenotype seen after OB-targeted deletion of Zfp521. Conversely, Ebf1 deletion led to cell-autonomous defects in both OB-dependent and cell-intrinsic OC-genesis, a phenotype opposite to that of the Zfp521 knockout. Thus, we have identified the interplay between Zfp521 and Ebf1 as a novel rheostat for bone homeostasis. PMID:23569325

c-Myc-Induced Survivin Is Essential for Promoting the Notch-Dependent T Cell Differentiation from Hematopoietic Stem Cells

PubMed Central

Haque, Rizwanul; Song, Jianyong; Haque, Mohammad; Lei, Fengyang; Sandhu, Praneet; Ni, Bing; Zheng, Songguo; Fang, Deyu; Yang, Jin-Ming; Song, Jianxun

2017-01-01

Notch is indispensable for T cell lineage commitment, and is needed for thymocyte differentiation at early phases. During early stages of T cell development, active Notch prevents other lineage potentials including B cell lineage and myeloid cell (e.g., dendritic cell) lineage. Nevertheless, the precise intracellular signaling pathways by which Notch promotes T cell differentiation remain unclear. Here we report that the transcription factor c-Myc is a key mediator of the Notch signaling–regulated T cell differentiation. In a well-established in vitro differentiation model of T lymphocytes from hematopoietic stem cells, we showed that Notch1 and 4 directly promoted c-Myc expression; dominant-negative (DN) c-Myc inhibited early T cell differentiation. Moreover, the c-Myc expression activated by Notch signaling increased the expression of survivin, an inhibitor of apoptosis (IAP) protein. We further demonstrated that over-expression of c-Myc increased the abundance of survivin and the T cell differentiation thereof, whereas dn c-Myc reduced survivin levels and concomitantly retarded the differentiation. The c-Myc–dependent survivin induction is functionally germane, because Notch-dependent T cell differentiation was canceled by the depletion of survivin. These results identify both c-Myc and survivin as important mediators of the Notch signaling–regulated differentiation of T lymphocytes from hematopoietic stem cells. PMID:28272325

Protein Tyrosine Phosphatase PRL2 Mediates Notch and Kit Signals in Early T Cell Progenitors.

PubMed

Kobayashi, Michihiro; Nabinger, Sarah C; Bai, Yunpeng; Yoshimoto, Momoko; Gao, Rui; Chen, Sisi; Yao, Chonghua; Dong, Yuanshu; Zhang, Lujuan; Rodriguez, Sonia; Yashiro-Ohtani, Yumi; Pear, Warren S; Carlesso, Nadia; Yoder, Mervin C; Kapur, Reuben; Kaplan, Mark H; Daniel Lacorazza, Hugo; Zhang, Zhong-Yin; Liu, Yan

2017-04-01

The molecular pathways regulating lymphoid priming, fate, and development of multipotent bone marrow hematopoietic stem and progenitor cells (HSPCs) that continuously feed thymic progenitors remain largely unknown. While Notch signal is indispensable for T cell specification and differentiation, the downstream effectors are not well understood. PRL2, a protein tyrosine phosphatase that regulates hematopoietic stem cell proliferation and self-renewal, is highly expressed in murine thymocyte progenitors. Here we demonstrate that protein tyrosine phosphatase PRL2 and receptor tyrosine kinase c-Kit are critical downstream targets and effectors of the canonical Notch/RBPJ pathway in early T cell progenitors. While PRL2 deficiency resulted in moderate defects of thymopoiesis in the steady state, de novo generation of T cells from Prl2 null hematopoietic stem cells was significantly reduced following transplantation. Prl2 null HSPCs also showed impaired T cell differentiation in vitro. We found that Notch/RBPJ signaling upregulated PRL2 as well as c-Kit expression in T cell progenitors. Further, PRL2 sustains Notch-mediated c-Kit expression and enhances stem cell factor/c-Kit signaling in T cell progenitors, promoting effective DN1-DN2 transition. Thus, we have identified a critical role for PRL2 phosphatase in mediating Notch and c-Kit signals in early T cell progenitors. Stem Cells 2017;35:1053-1064. © 2016 AlphaMed Press.

Integrative analysis of copy number and gene expression data suggests novel pathogenetic mechanisms in primary myelofibrosis.

PubMed

Salati, Simona; Zini, Roberta; Nuzzo, Simona; Guglielmelli, Paola; Pennucci, Valentina; Prudente, Zelia; Ruberti, Samantha; Rontauroli, Sebastiano; Norfo, Ruggiero; Bianchi, Elisa; Bogani, Costanza; Rotunno, Giada; Fanelli, Tiziana; Mannarelli, Carmela; Rosti, Vittorio; Salmoiraghi, Silvia; Pietra, Daniela; Ferrari, Sergio; Barosi, Giovanni; Rambaldi, Alessandro; Cazzola, Mario; Bicciato, Silvio; Tagliafico, Enrico; Vannucchi, Alessandro M; Manfredini, Rossella

2016-04-01

Primary myelofibrosis (PMF) is a Myeloproliferative Neoplasm (MPN) characterized by megakaryocyte hyperplasia, progressive bone marrow fibrosis, extramedullary hematopoiesis and transformation to Acute Myeloid Leukemia (AML). A number of phenotypic driver (JAK2, CALR, MPL) and additional subclonal mutations have been described in PMF, pointing to a complex genomic landscape. To discover novel genomic lesions that can contribute to disease phenotype and/or development, gene expression and copy number signals were integrated and several genomic abnormalities leading to a concordant alteration in gene expression levels were identified. In particular, copy number gain in the polyamine oxidase (PAOX) gene locus was accompanied by a coordinated transcriptional up-regulation in PMF patients. PAOX inhibition resulted in rapid cell death of PMF progenitor cells, while sparing normal cells, suggesting that PAOX inhibition could represent a therapeutic strategy to selectively target PMF cells without affecting normal hematopoietic cells' survival. Moreover, copy number loss in the chromatin modifier HMGXB4 gene correlates with a concomitant transcriptional down-regulation in PMF patients. Interestingly, silencing of HMGXB4 induces megakaryocyte differentiation, while inhibiting erythroid development, in human hematopoietic stem/progenitor cells. These results highlight a previously un-reported, yet potentially interesting role of HMGXB4 in the hematopoietic system and suggest that genomic and transcriptional imbalances of HMGXB4 could contribute to the aberrant expansion of the megakaryocytic lineage that characterizes PMF patients. © 2015 UICC.

Gadd45a deletion aggravates hematopoietic stem cell dysfunction in ATM-deficient mice.

PubMed

Chen, Yulin; Yang, Runan; Guo, Peng; Ju, Zhenyu

2014-01-01

Ataxia telangiectasia mutated (ATM) kinase plays an essential role in the maintenance of genomic stability. ATM-deficient (ATM(-/-)) mice exhibit hematopoietic stem cell (HSC) dysfunction and a high incidence of lymphoma. Gadd45a controls cell cycle arrest, apoptosis and DNA repair, and is involved in the ATM-p53 mediated DNA damage response. However, the role of Gadd45a in regulating the functionality of ATM(-/-) HSCs is unknown. Here we report that Gadd45a deletion did not rescue the defects of T-cells and B-cells development in ATM(-/-) mice. Instead, ATM and Gadd45a double knockout (ATM(-/-) Gadd45a(-/-)) HSCs exhibited an aggravated defect in long-term self-renewal capacity compared to ATM(-/-) HSCs in HSC transplantation experiments. Further experiments revealed that the aggravated defect of ATM(-/-) Gadd45a(-/-) HSCs was due to a reduction of cell proliferation, associated with an accumulation of DNA damage and subsequent activation of DNA damage response including an up-regulation of p53-p21 signaling pathway. Additionally, ATM(-/-) Gadd45a(-/-) mice showed an increased incidence of hematopoietic malignancies, as well as an increased rate of metastasis than ATM(-/-) mice. In conclusion, Gadd45a deletion aggravated the DNA damage accumulation, which subsequently resulted in a further impaired self-renewal capacity and an increased malignant transformation in ATM(-/-) HSCs.

Related-to-receptor tyrosine kinase receptor regulates hematopoietic stem and progenitor sensitivity to myelosuppressive injury in mice.

PubMed

Povinelli, Benjamin J; Srivastava, Pragya; Nemeth, Michael J

2015-03-01

Maintaining a careful balance between quiescence and proliferation of hematopoietic stem and progenitor cells (HSPCs) is necessary for lifelong blood formation. Previously, we demonstrated that the Wnt5a ligand inhibits HSPC proliferation through a functional interaction with a noncanonical Wnt ligand receptor termed 'related-to-receptor tyrosine kinase' (Ryk). Expression of Ryk on HSPCs in vivo is associated with a lower rate of proliferation, and, following treatment with fluorouracil (5-FU), the percentage of Ryk(+/high) HSPCs increased and the percentage of Ryk(-/low) HSPCs decreased. Based on these data, we hypothesized that one function of the Ryk receptor is to protect HSPCs from the effects of myeloablative agents. We found that Ryk expression on HSPCs is associated with lower rates of apoptosis following 5-FU and radiation. Transient inhibition of Ryk signaling in vivo resulted in increased hematopoietic-stem-cell proliferation and decreased hematopoietic-stem-cell function in bone marrow transplant assays. Furthermore, inhibition of Ryk signaling sensitized HSPCs to 5-FU treatment in association with increased levels of reactive oxygen species. Together, these results demonstrated an association between Ryk expression and survival of HSPCs following suppressive injury. Copyright © 2015 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Correlated miR-mRNA expression signatures of mouse hematopoietic stem and progenitor cell subsets predict "Stemness" and "Myeloid" interaction networks.

PubMed

Heiser, Diane; Tan, Yee Sun; Kaplan, Ian; Godsey, Brian; Morisot, Sebastien; Cheng, Wen-Chih; Small, Donald; Civin, Curt I

2014-01-01

Several individual miRNAs (miRs) have been implicated as potent regulators of important processes during normal and malignant hematopoiesis. In addition, many miRs have been shown to fine-tune intricate molecular networks, in concert with other regulatory elements. In order to study hematopoietic networks as a whole, we first created a map of global miR expression during early murine hematopoiesis. Next, we determined the copy number per cell for each miR in each of the examined stem and progenitor cell types. As data is emerging indicating that miRs function robustly mainly when they are expressed above a certain threshold (∼100 copies per cell), our database provides a resource for determining which miRs are expressed at a potentially functional level in each cell type. Finally, we combine our miR expression map with matched mRNA expression data and external prediction algorithms, using a Bayesian modeling approach to create a global landscape of predicted miR-mRNA interactions within each of these hematopoietic stem and progenitor cell subsets. This approach implicates several interaction networks comprising a "stemness" signature in the most primitive hematopoietic stem cell (HSC) populations, as well as "myeloid" patterns associated with two branches of myeloid development.

A Unique Case of Allogeneic Fat Grafting Between Brothers

PubMed Central

Kim, Samuel; Edelson, Richard L.; Sumpio, Brandon; Kwei, Stephanie

2016-01-01

Summary: We present a case of a 65-year-old man with cutaneous T-cell lymphoma treated with radiation therapy and an allogeneic hematopoietic stem cell transplant from his human leukocyte antigen-matched brother. Engraftment was successful, but the patient went on to develop painful, radiation-induced ulcers. The ulcers were fat-allografted using liposuctioned fat from his brother because of the patient’s unique chimeric state. Postprocedure follow-up revealed epithelialization of the ulcer sites and significant improvement in neuropathic pain. Our unique case study supports the use of fat grafting for its restorative purposes and for its ability to alleviate chronic neuropathic pain. Additionally, it appears that our case provides a basis of a general approach to the treatment of radiation-induced ulcers in chimeric patients with lymphoid malignancies. PMID:27757347

Health-related quality of life of hematopoietic stem cell transplant childhood survivors: state of the science.

PubMed

Tanzi, Elizabeth M

2011-01-01

The notion of health-related quality of life (HRQoL) holds unique significance in the treatment of patients who have undergone hematopoietic stem cell transplantation (HSCT). Not only is transplant procedure inevitably associated with immediate and late medical effects along with high mortality and morbidity rates, but it can also significantly affect the HRQoL for the patient and family. This review of literature will assist advanced practice nurses and pediatric oncology nurses in distinguishing and targeting interventions for patients and families who are at high risk of encountering distress during and following HSCT. It provides information on the assessment of pre-HSCT variables to identify patient subgroups in need of more aggressive supportive care to improve HRQoL during transplant. Furthermore, it serves as a guideline for developing interventional strategies and the role of the advanced practice nurse and pediatric oncology nurse caring for the patient throughout and following transplant.

Stem cell and genetic therapies for the fetus.

PubMed

Roybal, Jessica L; Santore, Matthew T; Flake, Alan W

2010-02-01

Advances in prenatal diagnosis have led to the prenatal management of a variety of congenital diseases. Although prenatal stem cell and gene therapy await clinical application, they offer tremendous potential for the treatment of many genetic disorders. Normal developmental events in the fetus offer unique biologic advantages for the engraftment of hematopoietic stem cells and efficient gene transfer that are not present after birth. Although barriers to hematopoietic stem cell engraftment exist, progress has been made and preclinical studies are now underway for strategies based on prenatal tolerance induction to facilitate postnatal cellular transplantation. Similarly, in-utero gene therapy shows experimental promise for a host of diseases and proof-in-principle has been demonstrated in murine models, but ethical and safety issues still need to be addressed. Here we review the current status and future potential of prenatal cellular and genetic therapy. Copyright 2009 Elsevier Ltd. All rights reserved.

Granulocyte colony-stimulating factor receptor signaling in severe congenital neutropenia, chronic neutrophilic leukemia, and related malignancies.

PubMed

Dwivedi, Pankaj; Greis, Kenneth D

2017-02-01

Granulocyte colony-stimulating factor is a hematopoietic cytokine that stimulates neutrophil production and hematopoietic stem cell mobilization by initiating the dimerization of homodimeric granulocyte colony-stimulating factor receptor. Different mutations of CSF3R have been linked to a unique spectrum of myeloid disorders and related malignancies. Myeloid disorders caused by the CSF3R mutations include severe congenital neutropenia, chronic neutrophilic leukemia, and atypical chronic myeloid leukemia. In this review, we provide an analysis of granulocyte colony-stimulating factor receptor, various mutations, and their roles in the severe congenital neutropenia, chronic neutrophilic leukemia, and malignant transformation, as well as the clinical implications and some perspective on approaches that could expand our knowledge with respect to the normal signaling mechanisms and those associated with mutations in the receptor. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Augmentation of anti-tumor immunity by adoptive T-cell transfer after allogeneic hematopoietic stem cell transplantation

PubMed Central

Bleakley, Marie; Turtle, Cameron J; Riddell, Stanley R

2012-01-01

Allogeneic hematopoietic stem cell transplantation (HCT) is currently the standard of care for most patients with high-risk acute leukemias and some other hematologic malignancies. Although HCT can be curative, many patients who undergo allogeneic HCT will later relapse. There is, therefore, a critical need for the development of novel post-HCT therapies for patients who are at high risk for disease recurrence following HCT. One potentially efficacious approach is adoptive T-cell immunotherapy, which is currently undergoing a renaissance that has been inspired by scientific insight into the key issues that impeded its previous clinical application. Translation of the next generation of adoptive T-cell therapies to the allogeneic HCT setting, using donor T cells of defined specificity and function, presents a unique set of challenges and opportunities. The challenges, progress and future of adoptive T-cell therapy following allogeneic HCT are discussed in this review. PMID:22992235

The cell fate determinant Llgl1 influences HSC fitness and prognosis in AML.

PubMed

Heidel, Florian H; Bullinger, Lars; Arreba-Tutusaus, Patricia; Wang, Zhu; Gaebel, Julia; Hirt, Carsten; Niederwieser, Dietger; Lane, Steven W; Döhner, Konstanze; Vasioukhin, Valera; Fischer, Thomas; Armstrong, Scott A

2013-01-14

A unique characteristic of hematopoietic stem cells (HSCs) is the ability to self-renew. Several genes and signaling pathways control the fine balance between self-renewal and differentiation in HSCs and potentially also in leukemia stem cells. Recently, studies have shed light on developmental molecules and evolutionarily conserved signals as regulators of stem cells in hematopoiesis and leukemia. In this study, we provide evidence that the cell fate determinant Llgl1 (lethal giant larvae homolog 1) plays an important role in regulation of HSCs. Loss of Llgl1 leads to an increase in HSC numbers that show increased repopulation capacity and competitive advantage after transplantation. This advantage increases upon serial transplantation or when stress is applied to HSCs. Llgl1(-/-) HSCs show increased cycling but neither exhaust nor induce leukemia in recipient mice. Llgl1 inactivation is associated with transcriptional repression of transcription factors such as KLF4 (Krüppel-like factor 4) and EGR1 (early-growth-response 1) that are known inhibitors of HSC self-renewal. Decreased Llgl1 expression in human acute myeloid leukemia (AML) cells is associated with inferior patient survival. Thus, inactivation of Llgl1 enhances HSC self-renewal and fitness and is associated with unfavorable outcome in human AML.

A monoallelic-to-biallelic T-cell transcriptional switch regulates GATA3 abundance

PubMed Central

Ku, Chia-Jui; Lim, Kim-Chew; Kalantry, Sundeep; Maillard, Ivan; Engel, James Douglas; Hosoya, Tomonori

2015-01-01

Protein abundance must be precisely regulated throughout life, and nowhere is the stringency of this requirement more evident than during T-cell development: A twofold increase in the abundance of transcription factor GATA3 results in thymic lymphoma, while reduced GATA3 leads to diminished T-cell production. GATA3 haploinsufficiency also causes human HDR (hypoparathyroidism, deafness, and renal dysplasia) syndrome, often accompanied by immunodeficiency. Here we show that loss of one Gata3 allele leads to diminished expansion (and compromised development) of immature T cells as well as aberrant induction of myeloid transcription factor PU.1. This effect is at least in part mediated transcriptionally: We discovered that Gata3 is monoallelically expressed in a parent of origin-independent manner in hematopoietic stem cells and early T-cell progenitors. Curiously, half of the developing cells switch to biallelic Gata3 transcription abruptly at midthymopoiesis. We show that the monoallelic-to-biallelic transcriptional switch is stably maintained and therefore is not a stochastic phenomenon. This unique mechanism, if adopted by other regulatory genes, may provide new biological insights into the rather prevalent phenomenon of monoallelic expression of autosomal genes as well as into the variably penetrant pathophysiological spectrum of phenotypes observed in many human syndromes that are due to haploinsufficiency of the affected gene. PMID:26385963

PEGylated G-CSF (BBT-015), GM-CSF (BBT-007), and IL-11 (BBT-059) analogs enhance survival and hematopoietic cell recovery in a mouse model of the hematopoietic syndrome of the acute radiation syndrome.

PubMed

Plett, Paul Artur; Chua, Hui Lin; Sampson, Carol H; Katz, Barry P; Fam, Christine M; Anderson, Lana J; Cox, George N; Orschell, Christie M

2014-01-01

Hematopoietic growth factors (HGF) are recommended therapy for high dose radiation exposure, but unfavorable administration schedules requiring early and repeat dosing limit the logistical ease with which they can be used. In this report, using a previously described murine model of H-ARS, survival efficacy and effect on hematopoietic recovery of unique PEGylated HGF were investigated. The PEGylated-HGFs possess longer half-lives and more potent hematopoietic properties than corresponding non-PEGylated-HGFs. C57BL/6 mice underwent single dose lethal irradiation (7.76-8.72 Gy, Cs, 0.62-1.02 Gy min) and were treated with various dosing regimens of 0.1, 0.3, and 1.0 mg kg of analogs of human PEG-G-CSF, murine PEG-GM-CSF, or human PEG-IL-11. Mice were administered one of the HGF analogs at 24-28 h post irradiation, and in some studies, additional doses given every other day (beginning with the 24-28 h dose) for a total of three or nine doses. Thirty-day (30 d) survival was significantly increased with only one dose of 0.3 mg kg of PEG-G-CSF and PEG-IL-11 or three doses of 0.3 mg kg of PEG-GM-CSF (p ≤ 0.006). Enhanced survival correlated with consistently and significantly enhanced WBC, NE, RBC, and PLT recovery for PEG-G- and PEG-GM-CSF, and enhanced RBC and PLT recovery for PEG-IL-11 (p ≤ 0.05). Longer administration schedules or higher doses did not provide a significant additional survival benefit over the shorter, lower dose, schedules. These data demonstrate the efficacy of BBT's PEG-HGF to provide significantly increased survival with fewer injections and lower drug doses, which may have significant economic and logistical value in the aftermath of a radiation event.

Rescue of the colony-stimulating factor 1 (CSF-1)-nullizygous mouse (Csf1(op)/Csf1(op)) phenotype with a CSF-1 transgene and identification of sites of local CSF-1 synthesis.

PubMed

Ryan, G R; Dai, X M; Dominguez, M G; Tong, W; Chuan, F; Chisholm, O; Russell, R G; Pollard, J W; Stanley, E R

2001-07-01

Colony-stimulating factor 1 (CSF-1) regulates the survival, proliferation, and differentiation of mononuclear phagocytes. It is expressed as a secreted glycoprotein or proteoglycan found in the circulation or as a biologically active cell-surface glycoprotein. To investigate tissue CSF-1 regulation, CSF-1-null Csf1(op)/Csf1(op) mice expressing transgenes encoding the full-length membrane-spanning CSF-1 precursor driven by 3.13 kilobases of the mouse CSF-1 promoter and first intron were characterized. Transgene expression corrected the gross osteopetrotic, neurologic, weight, tooth, and reproductive defects of Csf1(op)/Csf1(op) mice. Detailed analysis of one transgenic line revealed that circulating CSF-1, tissue macrophage numbers, hematopoietic tissue cellularity, and hematopoietic parameters were normalized. Tissue CSF-1 levels were normal except for elevations in 4 secretory tissues. Skin fibroblasts from the transgenic mice secreted normal amounts of CSF-1 but also expressed some cell-surface CSF-1. Also, lacZ driven by the same promoter/first intron revealed beta-galactosidase expression in hematopoietic, reproductive, and other tissue locations proximal to CSF-1 cellular targets, consistent with local regulation by CSF-1 at these sites. These studies indicate that the 3.13-kilobase promoter/first intron confers essentially normal CSF-1 expression. They also pinpoint new cellular sites of CSF-1 expression, including ovarian granulosa cells, mammary ductal epithelium, testicular Leydig cells, serous acinar cells of salivary gland, Paneth cells of the small intestine, as well as local sites in several other tissues.

Differentiation stage-specific regulation of primitive human hematopoietic progenitor cycling by exogenous and endogenous inhibitors in an in vivo model.

PubMed

Cashman, J D; Clark-Lewis, I; Eaves, A C; Eaves, C J

1999-12-01

Nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice transplanted with human cord blood or adult marrow cells and injected 6 weeks posttransplant with 2 daily doses of transforming growth factor-beta(1) (TGF-beta(1)), monocyte chemoattractant protein-1 (MCP-1), or a nonaggregating form of macrophage inflammatory protein-1alpha (MIP-1alpha) showed unique patterns of inhibition of human progenitor proliferation 1 day later. TGF-beta(1) was active on long-term culture initiating cells (LTC-IC) and on primitive erythroid and granulopoietic colony-forming cells (HPP-CFC), but had no effect on mature CFC. MCP-1 inhibited the cycling of both types of HPP-CFC but not LTC-IC. MIP-1alpha did not inhibit either LTC-IC or granulopoietic HPP-CFC but was active on erythroid HPP-CFC and mature granulopoietic CFC. All of these responses were independent of the source of human cells transplanted. LTC-IC of either human cord blood or adult marrow origin continue to proliferate in NOD/SCID mice for many weeks, although the turnover of all types of human CFC in mice transplanted with adult human marrow (but not cord blood) is downregulated after 6 weeks. Interestingly, administration of either MIP-1beta, an antagonist of both MIP-1alpha and MCP-1 or MCP-1(9-76), an antagonist of MCP-1 (and MCP-2 and MCP-3), into mice in which human marrow-derived CFC had become quiescent, caused the rapid reactivation of these progenitors in vivo. These results provide the first definition of stage-specific inhibitors of human hematopoietic progenitor cell cycling in vivo. In addition they show that endogenous chemokines can contribute to late graft failure, which can be reversed by the administration of specific antagonists.

Gene editing rescue of a novel MPL mutant associated with congenital amegakaryocytic thrombocytopenia.

PubMed

Cleyrat, Cédric; Girard, Romain; Choi, Eun H; Jeziorski, Éric; Lavabre-Bertrand, Thierry; Hermouet, Sylvie; Carillo, Serge; Wilson, Bridget S

2017-09-26

Thrombopoietin (Tpo) and its receptor (Mpl) are the principal regulators of early and late thrombopoiesis and hematopoietic stem cell maintenance. Mutations in MPL can drastically impair its function and be a contributing factor in multiple hematologic malignancies, including congenital amegakaryocytic thrombocytopenia (CAMT). CAMT is characterized by severe thrombocytopenia at birth, which progresses to bone marrow failure and pancytopenia. Here we report unique familial cases of CAMT that presented with a previously unreported MPL mutation: T814C (W272R) in the background of the activating MPL G117T (K39N or Baltimore) mutation. Confocal microscopy, proliferation and surface biotinylation assays, co-immunoprecipitation, and western blotting analysis were used to elucidate the function and trafficking of Mpl mutants. Results showed that Mpl protein bearing the W272R mutation, alone or together with the K39N mutation, lacks detectable surface expression while being strongly colocalized with the endoplasmic reticulum (ER) marker calreticulin. Both WT and K39N-mutated Mpl were found to be signaling competent, but single or double mutants bearing W272R were unresponsive to Tpo. Function of the deficient Mpl receptor could be rescued by using 2 separate approaches: (1) GRASP55 overexpression, which partially restored Tpo-induced signaling of mutant Mpl by activating an autophagy-dependent secretory pathway and thus forcing ER-trapped immature receptors to traffic to the cell surface; and (2) CRISPR-Cas9 gene editing used to repair MPL T814C mutation in transfected cell lines and primary umbilical cord blood-derived CD34 + cells. We demonstrate proof of principle for rescue of mutant Mpl function by using gene editing of primary hematopoietic stem cells, which indicates direct therapeutic applications for CAMT patients.

Gene editing rescue of a novel MPL mutant associated with congenital amegakaryocytic thrombocytopenia

PubMed Central

Girard, Romain; Choi, Eun H.; Jeziorski, Éric; Lavabre-Bertrand, Thierry; Hermouet, Sylvie; Carillo, Serge; Wilson, Bridget S.

2017-01-01

Thrombopoietin (Tpo) and its receptor (Mpl) are the principal regulators of early and late thrombopoiesis and hematopoietic stem cell maintenance. Mutations in MPL can drastically impair its function and be a contributing factor in multiple hematologic malignancies, including congenital amegakaryocytic thrombocytopenia (CAMT). CAMT is characterized by severe thrombocytopenia at birth, which progresses to bone marrow failure and pancytopenia. Here we report unique familial cases of CAMT that presented with a previously unreported MPL mutation: T814C (W272R) in the background of the activating MPL G117T (K39N or Baltimore) mutation. Confocal microscopy, proliferation and surface biotinylation assays, co-immunoprecipitation, and western blotting analysis were used to elucidate the function and trafficking of Mpl mutants. Results showed that Mpl protein bearing the W272R mutation, alone or together with the K39N mutation, lacks detectable surface expression while being strongly colocalized with the endoplasmic reticulum (ER) marker calreticulin. Both WT and K39N-mutated Mpl were found to be signaling competent, but single or double mutants bearing W272R were unresponsive to Tpo. Function of the deficient Mpl receptor could be rescued by using 2 separate approaches: (1) GRASP55 overexpression, which partially restored Tpo-induced signaling of mutant Mpl by activating an autophagy-dependent secretory pathway and thus forcing ER-trapped immature receptors to traffic to the cell surface; and (2) CRISPR-Cas9 gene editing used to repair MPL T814C mutation in transfected cell lines and primary umbilical cord blood–derived CD34+ cells. We demonstrate proof of principle for rescue of mutant Mpl function by using gene editing of primary hematopoietic stem cells, which indicates direct therapeutic applications for CAMT patients. PMID:29296828

Cloning and expression profile of FLT3 gene during progenitor cell-dependent liver regeneration.

PubMed

Aydin, Iraz T; Tokcaer, Zeynep; Dalgic, Aydin; Konu, Ozlen; Akcali, Kamil C

2007-12-01

The liver has a unique capacity to regenerate upon exposure to viral infections, toxic reactions and cancer formation. Liver regeneration is a complex phenomenon in which several factors participate during its onset. Cellular proliferation is an important component of this process and the factors that regulate this proliferation have a vital role. FLT3, a well-known hematopoietic stem cell and hepatic lineage surface marker, is involved in proliferative events of hematopoietic stem cells. However, its contribution to liver regeneration is not known. Therefore, the aim of this study was to clone and examine the role of FLT3 during liver regeneration in rats. Partial cDNA of rat homolog of FLT3 gene was cloned from thymus and the tissue specific expression of this gene at mRNA and protein levels was examined by RT-PCR and Western blot. After treating with 2-AAF and performing hepatectomy in rats to induce progenitor-dependent liver regeneration, the mRNA and protein expression profile of FLT3 was investigated by real-time PCR and Western blot during liver regeneration. In addition, cellular localization of FLT3 protein was determined by immunohistochemistry. The results indicated that rat FLT3 cDNA has high homology with mouse and human FLT3 cDNA. It was also found that FLT3 is expressed in most of the rat tissues and during liver regeneration. In addition, its intracellular localization is altered during the late stages of liver regeneration. The FLT3 receptor is activated at the late stages of liver regeneration and participates in the proliferation response that is observed during progenitor-dependent liver regeneration.

Host-Derived CD70 Suppresses Murine Graft-versus-Host Disease by Limiting Donor T Cell Expansion and Effector Function.

PubMed

Leigh, Nicholas D; O'Neill, Rachel E; Du, Wei; Chen, Chuan; Qiu, Jingxin; Ashwell, Jonathan D; McCarthy, Philip L; Chen, George L; Cao, Xuefang

2017-07-01

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment for hematologic and immunologic diseases. However, graft-versus-host disease (GVHD) may develop when donor-derived T cells recognize and damage genetically distinct normal host tissues. In addition to TCR signaling, costimulatory pathways are involved in T cell activation. CD27 is a TNFR family member expressed on T cells, and its ligand, CD70, is expressed on APCs. The CD27/CD70 costimulatory pathway was shown to be critical for T cell function and survival in viral infection models. However, the role of this pathway in allo-HCT is previously unknown. In this study, we have examined its contribution in GVHD pathogenesis. Surprisingly, Ab blockade of CD70 after allo-HCT significantly increases GVHD. Interestingly, whereas donor T cell- or bone marrow-derived CD70 plays no role in GVHD, host-derived CD70 inhibits GVHD as CD70 -/- hosts show significantly increased GVHD. This is evidenced by reduced survival, more severe weight loss, and increased histopathologic damage compared with wild-type hosts. In addition, CD70 -/- hosts have higher levels of proinflammatory cytokines TNF-α, IFN-γ, IL-2, and IL-17. Moreover, accumulation of donor CD4 + and CD8 + effector T cells is increased in CD70 -/- versus wild-type hosts. Mechanistic analyses suggest that CD70 expressed by host hematopoietic cells is involved in the control of alloreactive T cell apoptosis and expansion. Together, our findings demonstrate that host CD70 serves as a unique negative regulator of allogeneic T cell response by contributing to donor T cell apoptosis and inhibiting expansion of donor effector T cells. Copyright © 2017 by The American Association of Immunologists, Inc.

Identification of key factors regulating self-renewal and differentiation in EML hematopoietic precursor cells by RNA-sequencing analysis.

PubMed

Zong, Shan; Deng, Shuyun; Chen, Kenian; Wu, Jia Qian

2014-11-11

Hematopoietic stem cells (HSCs) are used clinically for transplantation treatment to rebuild a patient's hematopoietic system in many diseases such as leukemia and lymphoma. Elucidating the mechanisms controlling HSCs self-renewal and differentiation is important for application of HSCs for research and clinical uses. However, it is not possible to obtain large quantity of HSCs due to their inability to proliferate in vitro. To overcome this hurdle, we used a mouse bone marrow derived cell line, the EML (Erythroid, Myeloid, and Lymphocytic) cell line, as a model system for this study. RNA-sequencing (RNA-Seq) has been increasingly used to replace microarray for gene expression studies. We report here a detailed method of using RNA-Seq technology to investigate the potential key factors in regulation of EML cell self-renewal and differentiation. The protocol provided in this paper is divided into three parts. The first part explains how to culture EML cells and separate Lin-CD34+ and Lin-CD34- cells. The second part of the protocol offers detailed procedures for total RNA preparation and the subsequent library construction for high-throughput sequencing. The last part describes the method for RNA-Seq data analysis and explains how to use the data to identify differentially expressed transcription factors between Lin-CD34+ and Lin-CD34- cells. The most significantly differentially expressed transcription factors were identified to be the potential key regulators controlling EML cell self-renewal and differentiation. In the discussion section of this paper, we highlight the key steps for successful performance of this experiment. In summary, this paper offers a method of using RNA-Seq technology to identify potential regulators of self-renewal and differentiation in EML cells. The key factors identified are subjected to downstream functional analysis in vitro and in vivo.

Identification of Key Factors Regulating Self-renewal and Differentiation in EML Hematopoietic Precursor Cells by RNA-sequencing Analysis

PubMed Central

Chen, Kenian; Wu, Jia Qian

2014-01-01

Hematopoietic stem cells (HSCs) are used clinically for transplantation treatment to rebuild a patient's hematopoietic system in many diseases such as leukemia and lymphoma. Elucidating the mechanisms controlling HSCs self-renewal and differentiation is important for application of HSCs for research and clinical uses. However, it is not possible to obtain large quantity of HSCs due to their inability to proliferate in vitro. To overcome this hurdle, we used a mouse bone marrow derived cell line, the EML (Erythroid, Myeloid, and Lymphocytic) cell line, as a model system for this study. RNA-sequencing (RNA-Seq) has been increasingly used to replace microarray for gene expression studies. We report here a detailed method of using RNA-Seq technology to investigate the potential key factors in regulation of EML cell self-renewal and differentiation. The protocol provided in this paper is divided into three parts. The first part explains how to culture EML cells and separate Lin-CD34+ and Lin-CD34- cells. The second part of the protocol offers detailed procedures for total RNA preparation and the subsequent library construction for high-throughput sequencing. The last part describes the method for RNA-Seq data analysis and explains how to use the data to identify differentially expressed transcription factors between Lin-CD34+ and Lin-CD34- cells. The most significantly differentially expressed transcription factors were identified to be the potential key regulators controlling EML cell self-renewal and differentiation. In the discussion section of this paper, we highlight the key steps for successful performance of this experiment. In summary, this paper offers a method of using RNA-Seq technology to identify potential regulators of self-renewal and differentiation in EML cells. The key factors identified are subjected to downstream functional analysis in vitro and in vivo. PMID:25407807

Pleiotrophin regulates the expansion and regeneration of hematopoietic stem cells

PubMed Central

Himburg, Heather A; Muramoto, Garrett G; Daher, Pamela; Meadows, Sarah K; Russell, J Lauren; Doan, Phuong; Chi, Jen-Tsan; Salter, Alice B; Lento, William E; Reya, Tannishtha; Chao, Nelson; Chute, John P

2013-01-01

Hematopoietic stem cell (HSC) self-renewal is regulated by both intrinsic and extrinsic signals. Although some of the pathways that regulate HSC self-renewal have been uncovered, it remains largely unknown whether these pathways can be triggered by deliverable growth factors to induce HSC growth or regeneration. Here we show that pleiotrophin, a neurite outgrowth factor with no known function in hematopoiesis, efficiently promotes HSC expansion in vitro and HSC regeneration in vivo. Treatment of mouse bone marrow HSCs with pleiotrophin caused a marked increase in long-term repopulating HSC counts in culture, as measured in competitive repopulating assays. Treatment of human cord blood CD34+CDCD38−Lin− cells with pleiotrophin also substantially increased severe combined immunodeficient (SCID)-repopulating cell counts in culture, compared to input and cytokine-treated cultures. Systemic administration of pleiotrophin to irradiated mice caused a pronounced expansion of bone marrow stem and progenitor cells in vivo, indicating that pleiotrophin is a regenerative growth factor for HSCs. Mechanistically, pleiotrophin activated phosphoinositide 3-kinase (PI3K) signaling in HSCs; antagonism of PI3K or Notch signaling inhibited pleiotrophin-mediated expansion of HSCs in culture. We identify the secreted growth factor pleiotrophin as a new regulator of both HSC expansion and regeneration PMID:20305662

Pleiotrophin regulates the expansion and regeneration of hematopoietic stem cells.

PubMed

Himburg, Heather A; Muramoto, Garrett G; Daher, Pamela; Meadows, Sarah K; Russell, J Lauren; Doan, Phuong; Chi, Jen-Tsan; Salter, Alice B; Lento, William E; Reya, Tannishtha; Chao, Nelson J; Chute, John P

2010-04-01

Hematopoietic stem cell (HSC) self-renewal is regulated by both intrinsic and extrinsic signals. Although some of the pathways that regulate HSC self-renewal have been uncovered, it remains largely unknown whether these pathways can be triggered by deliverable growth factors to induce HSC growth or regeneration. Here we show that pleiotrophin, a neurite outgrowth factor with no known function in hematopoiesis, efficiently promotes HSC expansion in vitro and HSC regeneration in vivo. Treatment of mouse bone marrow HSCs with pleiotrophin caused a marked increase in long-term repopulating HSC numbers in culture, as measured in competitive repopulating assays. Treatment of human cord blood CD34(+)CDCD38(-)Lin(-) cells with pleiotrophin also substantially increased severe combined immunodeficient (SCID)-repopulating cell counts in culture, compared to input and cytokine-treated cultures. Systemic administration of pleiotrophin to irradiated mice caused a pronounced expansion of bone marrow stem and progenitor cells in vivo, indicating that pleiotrophin is a regenerative growth factor for HSCs. Mechanistically, pleiotrophin activated phosphoinositide 3-kinase (PI3K) signaling in HSCs; antagonism of PI3K or Notch signaling inhibited pleiotrophin-mediated expansion of HSCs in culture. We identify the secreted growth factor pleiotrophin as a new regulator of both HSC expansion and regeneration.

Regulation of hematopoietic stem cell aging by the small RhoGTPase Cdc42

PubMed Central

Geiger, Hartmut; Zheng, Yi

2015-01-01

Summary Aging of stem cells might be the underlying cause of tissue aging in tissue that in the adult heavily rely on stem cell activity, like the blood forming system. Hematopoiesis, the generation of blood forming cells, is sustained by hematopoietic stem cells. In this review article, we introduce the canonical set of phenotypes associated with aged HSCs, focus on the novel aging-associated phenotype apolarity caused by elevated activity of the small RhoGTPase in aged HSCs, disuccs the role of Cdc42 in hematopoiesis and describe that pharmacological inhibition of Cdc42 activity in aged HSCs results in functionally young and thus rejuvenated HSCs. PMID:25220425

Open the gates: vascular neurocrine signaling mobilizes hematopoietic stem and progenitor cells.

PubMed

Itkin, Tomer; Gómez-Salinero, Jesús María; Rafii, Shahin

2017-12-01

Mobilization of hematopoietic stem and progenitor cells (HSPCs) from the bone marrow (BM) into the peripheral blood is a complex process that is enhanced dramatically under stress-induced conditions. A better understanding of how the mobilization process is regulated will likely facilitate the development of improved clinical protocols for stem cell harvesting and transplantation. In this issue of the JCI, Singh et al. (1) showed that the truncated cleaved form of neurotransmitter neuropeptide Y (NPY) actively promotes a breach of BM vascular sinusoidal portals, thereby augmenting HSPC trafficking to the circulation. The authors report a previously unrecognized axis, in which expression of the enzyme dipeptidylpeptidase-4 (DPP4)/CD26 by endothelial cells activates NPY-mediated signaling by increasing the bioavailability of the truncated form of NPY. These findings underscore the importance of and urgency to develop pharmacological therapies that target the vasculature and regulate diverse aspects of hematopoiesis, such as HSPC trafficking, in steady-state and stress-induced conditions.

Accumulation of the Vitamin D Precursor Cholecalciferol Antagonizes Hedgehog Signaling to Impair Hemogenic Endothelium Formation

PubMed Central

Cortes, Mauricio; Liu, Sarah Y.; Kwan, Wanda; Alexa, Kristen; Goessling, Wolfram; North, Trista E.

2015-01-01

Summary Hematopoietic stem and progenitor cells (HSPCs) are born from hemogenic endothelium in the dorsal aorta. Specification of this hematopoietic niche is regulated by a signaling axis using Hedgehog (Hh) and Notch, which culminates in expression of Runx1 in the ventral wall of the artery. Here, we demonstrate that the vitamin D precursor cholecalciferol (D3) modulates HSPC production by impairing hemogenic vascular niche formation. Accumulation of D3 through exogenous treatment or inhibition of Cyp2r1, the enzyme required for D3 25-hydroxylation, results in Hh pathway antagonism marked by loss of Gli-reporter activation, defects in vascular niche identity, and reduced HSPCs. Mechanistic studies indicated the effect was specific to D3, and not active 1,25-dihydroxy vitamin D3, acting on the extracellular sterol-binding domain of Smoothened. These findings highlight a direct impact of inefficient vitamin D synthesis on cell fate commitment and maturation in Hh-regulated tissues, which may have implications beyond hemogenic endothelium specification. PMID:26365513

Discovering Hematopoietic Mechanisms Through Genome-Wide Analysis of GATA Factor Chromatin Occupancy

PubMed Central

Fujiwara, Tohru; O'Geen, Henriette; Keles, Sunduz; Blahnik, Kimberly; Linnemann, Amelia K.; Kang, Yoon-A; Choi, Kyunghee; Farnham, Peggy J.; Bresnick, Emery H.

2009-01-01

SUMMARY GATA factors interact with simple DNA motifs (WGATAR) to regulate critical processes, including hematopoiesis, but very few WGATAR motifs are occupied in genomes. Given the rudimentary knowledge of mechanisms underlying this restriction, and how GATA factors establish genetic networks, we used ChIP-seq to define GATA-1 and GATA-2 occupancy genome-wide in erythroid cells. Coupled with genetic complementation analysis and transcriptional profiling, these studies revealed a rich collection of targets containing a characteristic binding motif of greater complexity than WGATAR. GATA factors occupied loci encoding multiple components of the Scl/TAL1 complex, a master regulator of hematopoiesis and leukemogenic target. Mechanistic analyses provided evidence for cross-regulatory and autoregulatory interactions among components of this complex, including GATA-2 induction of the hematopoietic corepressor ETO-2 and an ETO-2 negative autoregulatory loop. These results establish fundamental principles underlying GATA factor mechanisms in chromatin and illustrate a complex network of considerable importance for the control of hematopoiesis. PMID:19941826

Hematopoietic Kit Deficiency, rather than Lack of Mast Cells, Protects Mice from Obesity and Insulin Resistance.

PubMed

Gutierrez, Dario A; Muralidhar, Sathya; Feyerabend, Thorsten B; Herzig, Stephan; Rodewald, Hans-Reimer

2015-05-05

Obesity, insulin resistance, and related pathologies are associated with immune-mediated chronic inflammation. Kit mutant mice are protected from diet-induced obesity and associated co-morbidities, and this phenotype has previously been attributed to their lack of mast cells. We performed a comprehensive metabolic analysis of Kit-dependent Kit(W/Wv) and Kit-independent Cpa3(Cre/+) mast-cell-deficient mouse strains, employing diet-induced or genetic (Lep(Ob/Ob) background) models of obesity. Our results show that mast cell deficiency, in the absence of Kit mutations, plays no role in the regulation of weight gain or insulin resistance. Moreover, we provide evidence that the metabolic phenotype observed in Kit mutant mice, while independent of mast cells, is immune regulated. Our data underscore the value of definitive mast cell deficiency models to conclusively test the involvement of this enigmatic cell in immune-mediated pathologies and identify Kit as a key hematopoietic factor in the pathogenesis of metabolic syndrome. Copyright © 2015 Elsevier Inc. All rights reserved.

Rapid Inflammation in Mice Lacking Both SOCS1 and SOCS3 in Hematopoietic Cells

PubMed Central

Ushiki, Takashi; Huntington, Nicholas D.; Glaser, Stefan P.; Kiu, Hiu; Georgiou, Angela; Zhang, Jian-Guo; Nicola, Nicos A.; Roberts, Andrew W.; Alexander, Warren S.

2016-01-01

The Suppressors of Cytokine Signalling (SOCS) proteins are negative regulators of cytokine signalling required to prevent excess cellular responses. SOCS1 and SOCS3 are essential to prevent inflammatory disease, SOCS1 by attenuating responses to IFNγ and gamma-common (γc) cytokines, and SOCS3 via regulation of G-CSF and IL-6 signalling. SOCS1 and SOCS3 show significant sequence homology and are the only SOCS proteins to possess a KIR domain. The possibility of overlapping or redundant functions was investigated in inflammatory disease via generation of mice lacking both SOCS1 and SOCS3 in hematopoietic cells. Loss of SOCS3 significantly accelerated the pathology and inflammatory disease characteristic of SOCS1 deficiency. We propose a model in which SOCS1 and SOCS3 operate independently to control specific cytokine responses and together modulate the proliferation and activation of lymphoid and myeloid cells to prevent rapid inflammatory disease. PMID:27583437

Immunomodulation: A definitive role of microRNA-142.

PubMed

Sharma, Salil

2017-12-01

Majority of microRNAs are evolutionarily conserved in vertebrates. This is suggestive of their similar roles in regulation of gene networks. In addition to their conserved mature sequences and regulatory roles, a few microRNAs show very cell or tissue specific expression. These microRNAs are highly enriched in some cell types or organs. One such microRNA is microRNA-142 (miR-142). The classical stem-loop structure of miR142 encodes for two species of mature microRNAs; miR142-5p and miR142-3p. MiR-142 is abundant in cells of hematopoietic origin, and therefore, aptly plays a role in lineage differentiation of hematopoietic cells. Interestingly, over the years, miR-142 has gained considerable attention for its quintessential role in regulating immune response. This mini-review discusses the important functional roles of miR-142 in inflammatory and immune response in different physiological and disease setting. Copyright © 2017 Elsevier Ltd. All rights reserved.

Profilin 1 is essential for retention and metabolism of mouse hematopoietic stem cells in bone marrow

PubMed Central

Zheng, Junke; Lu, Zhigang; Kocabas, Fatih; Böttcher, Ralph T.; Costell, Mercedes; Kang, Xunlei; Liu, Xiaoye; DeBerardinis, Ralph J.; Wang, Qianming; Chen, Guo-Qiang

2014-01-01

How stem cells interact with the microenvironment to regulate their cell fates and metabolism is largely unknown. Here we demonstrated that the deletion of the cytoskeleton-modulating protein profilin 1 (pfn1) in hematopoietic stem cell (HSCs) led to bone marrow failure, loss of quiescence, and mobilization and apoptosis of HSCs in vivo. A switch from glycolysis to mitochondrial respiration with increased reactive oxygen species (ROS) level was also observed in HSCs on pfn1 deletion. Importantly, treatment of pfn1-deficient mice with the antioxidant N-acetyl-l-cysteine reversed the ROS level and loss of quiescence of HSCs, suggesting that the metabolism is mechanistically linked to the cell cycle quiescence of stem cells. The actin-binding and proline-binding activities of pfn1 are required for its function in HSCs. Our study provided evidence that pfn1 at least partially acts through the axis of pfn1/Gα13/EGR1 to regulate stem cell retention and metabolism in the bone marrow. PMID:24385538

Cyclophosphamide Alters the Gene Expression Profile in Patients Treated with High Doses Prior to Stem Cell Transplantation

PubMed Central

El-Serafi, Ibrahim; Abedi-Valugerdi, Manuchehr; Potácová, Zuzana; Afsharian, Parvaneh; Mattsson, Jonas; Moshfegh, Ali; Hassan, Moustapha

2014-01-01

Background Hematopoietic stem cell transplantation is a curative treatment for several haematological malignancies. However, treatment related morbidity and mortality still is a limiting factor. Cyclophosphamide is widely used in condition regimens either in combination with other chemotherapy or with total body irradiation. Methods We present the gene expression profile during cyclophosphamide treatment in 11 patients conditioned with cyclophosphamide for 2 days followed by total body irradiation prior to hematopoietic stem cell transplantation. 299 genes were identified as specific for cyclophosphamide treatment and were arranged into 4 clusters highly down-regulated genes, highly up-regulated genes, early up-regulated but later normalized genes and moderately up-regulated genes. Results Cyclophosphamide treatment down-regulated expression of several genes mapped to immune/autoimmune activation and graft rejection including CD3, CD28, CTLA4, MHC II, PRF1, GZMB and IL-2R, and up-regulated immune-related receptor genes, e.g. IL1R2, IL18R1, and FLT3. Moreover, a high and significant expression of ANGPTL1 and c-JUN genes was observed independent of cyclophosphamide treatment. Conclusion This is the first investigation to provide significant information about alterations in gene expression following cyclophosphamide treatment that may increase our understanding of the cyclophosphamide mechanism of action and hence, in part, avoid its toxicity. Furthermore, ANGPTL1 remained highly expressed throughout the treatment and, in contrast to several other alkylating agents, cyclophosphamide did not influence c-JUN expression. PMID:24466173

Cyclophosphamide alters the gene expression profile in patients treated with high doses prior to stem cell transplantation.

PubMed

El-Serafi, Ibrahim; Abedi-Valugerdi, Manuchehr; Potácová, Zuzana; Afsharian, Parvaneh; Mattsson, Jonas; Moshfegh, Ali; Hassan, Moustapha

2014-01-01

Hematopoietic stem cell transplantation is a curative treatment for several haematological malignancies. However, treatment related morbidity and mortality still is a limiting factor. Cyclophosphamide is widely used in condition regimens either in combination with other chemotherapy or with total body irradiation. We present the gene expression profile during cyclophosphamide treatment in 11 patients conditioned with cyclophosphamide for 2 days followed by total body irradiation prior to hematopoietic stem cell transplantation. 299 genes were identified as specific for cyclophosphamide treatment and were arranged into 4 clusters highly down-regulated genes, highly up-regulated genes, early up-regulated but later normalized genes and moderately up-regulated genes. Cyclophosphamide treatment down-regulated expression of several genes mapped to immune/autoimmune activation and graft rejection including CD3, CD28, CTLA4, MHC II, PRF1, GZMB and IL-2R, and up-regulated immune-related receptor genes, e.g. IL1R2, IL18R1, and FLT3. Moreover, a high and significant expression of ANGPTL1 and c-JUN genes was observed independent of cyclophosphamide treatment. This is the first investigation to provide significant information about alterations in gene expression following cyclophosphamide treatment that may increase our understanding of the cyclophosphamide mechanism of action and hence, in part, avoid its toxicity. Furthermore, ANGPTL1 remained highly expressed throughout the treatment and, in contrast to several other alkylating agents, cyclophosphamide did not influence c-JUN expression.

Expansion of Human and Murine Hematopoietic Stem and Progenitor Cells Ex Vivo without Genetic Modification Using MYC and Bcl-2 Fusion Proteins

PubMed Central

Bird, Gregory A.; Polsky, Avital; Estes, Patricia; Hanlon, Teri; Hamilton, Haley; Morton, John J.; Gutman, Jonathan; Jimeno, Antonio

2014-01-01

The long-term repopulating hematopoietic stem cell (HSC) population can self-renew in vivo, support hematopoiesis for the lifetime of the individual, and is of critical importance in the context of bone marrow stem cell transplantation. The mechanisms that regulate the expansion of HSCs in vivo and in vitro remain unclear to date. Since the current set of surface markers only allow for the identification of a population of cells that is highly enriched for HSC activity, we will refer to the population of cells we expand as Hematopoietic Stem and Progenitor cells (HSPCs). We describe here a novel approach to expand a cytokine-dependent Hematopoietic Stem and Progenitor Cell (HSPC) population ex vivo by culturing primary adult human or murine HSPCs with fusion proteins including the protein transduction domain of the HIV-1 transactivation protein (Tat) and either MYC or Bcl-2. HSPCs obtained from either mouse bone marrow, human cord blood, human G-CSF mobilized peripheral blood, or human bone marrow were expanded an average of 87 fold, 16.6 fold, 13.6 fold, or 10 fold, respectively. The expanded cell populations were able to give rise to different types of colonies in methylcellulose assays in vitro, as well as mature hematopoietic populations in vivo upon transplantation into irradiated mice. Importantly, for both the human and murine case, the ex vivo expanded cells also gave rise to a self-renewing cell population in vivo, following initial transplantation, that was able to support hematopoiesis upon serial transplantation. Our results show that a self-renewing cell population, capable of reconstituting the hematopoietic compartment, expanded ex vivo in the presence of Tat-MYC and Tat-Bcl-2 suggesting that this may be an attractive approach to expand human HSPCs ex vivo for clinical use. PMID:25170611

The Adult Livers of Immunodeficient Mice Support Human Hematopoiesis: Evidence for a Hepatic Mast Cell Population that Develops Early in Human Ontogeny

PubMed Central

Muench, Marcus O.; Beyer, Ashley I.; Fomin, Marina E.; Thakker, Rahul; Mulvaney, Usha S.; Nakamura, Masato; Suemizu, Hiroshi; Bárcena, Alicia

2014-01-01

The liver plays a vital role in hematopoiesis during mammalian prenatal development but its hematopoietic output declines during the perinatal period. Nonetheless, hepatic hematopoiesis is believed to persist into adulthood. We sought to model human adult-liver hematopoiesis by transplantation of fetal and neonatal hematopoietic stem cells (HSCs) into adult immunodeficient mice. Livers were found to be engrafted with human cells consisting primarily of monocytes and B-cells with lesser contributions by erythrocytes, T-cells, NK-cells and mast-cells. A resident population of CD117++CD203c+ mast cells was also documented in human midgestation liver, indicating that these cells comprise part of the liver's resident immune cell repertoire throughout human ontogeny. The murine liver was shown to support human multilineage hematopoiesis up to 321 days after transplant. Evidence of murine hepatic hematopoiesis was also found in common mouse strains as old as 2 years. Human HSC engraftment of the murine liver was demonstrated by detection of high proliferative-potential colony-forming cells in clonal cultures, observation of CD38−CD34++ and CD133+CD34++ cells by flow cytometry, and hematopoietic reconstitution of secondary transplant recipients of chimeric liver cells. Additionally, chimeric mice with both hematopoietic and endothelial reconstitution were generated by intrasplenic injection of immunodeficient mice with liver specific expression of the urokinase-type plasminogen activator (uPA) transgene. In conclusion, the murine liver is shown to be a hematopoietic organ throughout adult life that can also support human hematopoiesis in severely immunodeficient strains. Further humanization of the murine liver can be achieved in mice harboring an uPA transgene, which support engraftment of non-hematopoietic cells types. Thus, offering a model system to study the interaction of diverse human liver cell types that regulate hematopoiesis and immune function in the liver. PMID:24819392

Local bone marrow renin-angiotensin system in the genesis of leukemia and other malignancies.

PubMed

Haznedaroglu, I C; Malkan, U Y

2016-10-01

The existence of a local renin-angiotensin system (RAS) specific to the hematopoietic bone marrow (BM) microenvironment had been proposed two decades ago. Most of the RAS molecules including ACE, ACE2, AGT, AGTR1, AGTR2, AKR1C4, AKR1D1, ANPEP, ATP6AP2, CMA1, CPA3, CTSA, CTSD, CTSG, CYP11A1, CYP11B1, CYP11B2, CYP17A1, CYP21A2, DPP3, EGFR, ENPEP, GPER, HSD11B1, HSD11B2, IGF2R, KLK1, LNPEP, MAS1, MME, NR3C1, NR3C2, PREP, REN, RNPEP, and THOP1 are locally present in the BM microenvironment. Local BM RAS peptides control the hematopoietic niche, myelopoiesis, erythropoiesis, thrombopoiesis and the development of other cellular lineages. Local BM RAS is important in hematopoietic stem cell biology and microenvironment. Angiotensin II regulates the proliferation, differentiation, and engraftment of hematopoietic stem cells. Activation of Mas receptor or ACE2 promotes proliferation of CD34+ cells. BM contains a progenitor that expresses renin throughout development. Angiotensin II attenuates the migration and proliferation of CD34+ Cells and promotes the adhesion of both MNCs and CD34+ cells. Renin cells in hematopoietic organs are precursor B cells. The renin cell requires RBP-J to differentiate. Mutant renin-expressing hematopoietic precursors can cause leukemia. Deletion of RBP-J in the renin-expressing progenitors enriches the precursor B-cell gene programme. Mutant cells undergo a neoplastic transformation, and mice develop a highly penetrant B-cell leukemia with multi-organ infiltration and early death. Many biological conditions during the development and function of blood cells are mediated by RAS, such as apoptosis, cellular proliferation, intracellular signaling, mobilization, angiogenesis, and fibrosis. The aim of this paper is to review recent developments regarding the actions of local BM RAS in the genesis of leukemia and other malignancies molecules.

Novel Insights into the Genetic Controls of Primitive and Definitive Hematopoiesis from Zebrafish Models

PubMed Central

Sood, Raman; Liu, Paul

2012-01-01

Hematopoiesis is a dynamic process where initiation and maintenance of hematopoietic stem cells, as well as their differentiation into erythroid, myeloid and lymphoid lineages, are tightly regulated by a network of transcription factors. Understanding the genetic controls of hematopoiesis is crucial as perturbations in hematopoiesis lead to diseases such as anemia, thrombocytopenia, or cancers, including leukemias and lymphomas. Animal models, particularly conventional and conditional knockout mice, have played major roles in our understanding of the genetic controls of hematopoiesis. However, knockout mice for most of the hematopoietic transcription factors are embryonic lethal, thus precluding the analysis of their roles during the transition from embryonic to adult hematopoiesis. Zebrafish are an ideal model organism to determine the function of a gene during embryonic-to-adult transition of hematopoiesis since bloodless zebrafish embryos can develop normally into early larval stage by obtaining oxygen through diffusion. In this review, we discuss the current status of the ontogeny and regulation of hematopoiesis in zebrafish. By providing specific examples of zebrafish morphants and mutants, we have highlighted the contributions of the zebrafish model to our overall understanding of the roles of transcription factors in regulation of primitive and definitive hematopoiesis. PMID:22888355

Discrete Notch signaling requirements in the specification of hematopoietic stem cells

PubMed Central

Kim, Albert D; Melick, Chase H; Clements, Wilson K; Stachura, David L; Distel, Martin; Panáková, Daniela; MacRae, Calum; Mork, Lindsey A; Crump, J Gage; Traver, David

2014-01-01

Hematopoietic stem cells (HSCs) require multiple molecular inputs for proper specification, including activity of the Notch signaling pathway. A requirement for the Notch1 and dispensability of the Notch2 receptor has been demonstrated in mice, but the role of the remaining Notch receptors has not been investigated. Here, we demonstrate that three of the four Notch receptors are independently required for the specification of HSCs in the zebrafish. The orthologues of the murine Notch1 receptor, Notch1a and Notch1b, are each required intrinsically to fate HSCs, just prior to their emergence from aortic hemogenic endothelium. By contrast, the Notch3 receptor is required earlier within the developing somite to regulate HSC emergence in a non-cell-autonomous manner. Epistatic analyses demonstrate that Notch3 function lies downstream of Wnt16, which is required for HSC specification through its regulation of two Notch ligands, dlc and dld. Collectively, these findings demonstrate for the first time that multiple Notch signaling inputs are required to specify HSCs and that Notch3 performs a novel role within the somite to regulate the neighboring precursors of hemogenic endothelium. PMID:25230933

Growth Factor-Activated Stem Cell Circuits and Stromal Signals Cooperatively Accelerate Non-Integrated iPSC Reprogramming of Human Myeloid Progenitors

PubMed Central

Park, Tea Soon; Huo, Jeffrey S.; Peters, Ann; Talbot, C. Conover; Verma, Karan; Zimmerlin, Ludovic; Kaplan, Ian M.; Zambidis, Elias T.

2012-01-01

Nonviral conversion of skin or blood cells into clinically useful human induced pluripotent stem cells (hiPSC) occurs in only rare fractions (∼0.001%–0.5%) of donor cells transfected with non-integrating reprogramming factors. Pluripotency induction of developmentally immature stem-progenitors is generally more efficient than differentiated somatic cell targets. However, the nature of augmented progenitor reprogramming remains obscure, and its potential has not been fully explored for improving the extremely slow pace of non-integrated reprogramming. Here, we report highly optimized four-factor reprogramming of lineage-committed cord blood (CB) myeloid progenitors with bulk efficiencies of ∼50% in purified episome-expressing cells. Lineage-committed CD33+CD45+CD34− myeloid cells and not primitive hematopoietic stem-progenitors were the main targets of a rapid and nearly complete non-integrated reprogramming. The efficient conversion of mature myeloid populations into NANOG+TRA-1-81+ hiPSC was mediated by synergies between hematopoietic growth factor (GF), stromal activation signals, and episomal Yamanaka factor expression. Using a modular bioinformatics approach, we demonstrated that efficient myeloid reprogramming correlated not to increased proliferation or endogenous Core factor expressions, but to poised expression of GF-activated transcriptional circuits that commonly regulate plasticity in both hematopoietic progenitors and embryonic stem cells (ESC). Factor-driven conversion of myeloid progenitors to a high-fidelity pluripotent state was further accelerated by soluble and contact-dependent stromal signals that included an implied and unexpected role for Toll receptor-NFκB signaling. These data provide a paradigm for understanding the augmented reprogramming capacity of somatic progenitors, and reveal that efficient induced pluripotency in other cell types may also require extrinsic activation of a molecular framework that commonly regulates self-renewal and differentiation in both hematopoietic progenitors and ESC. PMID:22905176

Hormones that Stimulate the Growth of Blood Cells.

ERIC Educational Resources Information Center

Golde, David W.; Gasson, Judith C.

1988-01-01

Describes the nature and action of hematopoietic proteins which regulate the production of specific sets of blood cells. Discusses the production of these hematopoietins by recombinant-DNA methods in an effort to enable physicians to treat patients by eliciting production of specific types of blood cells. (CW)

Human hematopoietic progenitors express erythropoietin.

PubMed

Stopka, T; Zivny, J H; Stopkova, P; Prchal, J F; Prchal, J T

1998-05-15

Erythropoietin (EPO) is a factor essential for erythroid cell proliferation, differentiation, and survival. The production of EPO by the kidneys in response to hypoxia and anemia is well documented. To determine whether EPO is also produced by hematopoietic cells, we analyzed the expression of EPO in normal human hematopoietic progenitors and in their progeny. Undifferentiated CD34(+)lin- hematopoietic progenitors do not have detectable EPO mRNA. Differentiating CD34(+) cells that are stimulated with recombinant human EPO in serum-free liquid cultures express both EPO and EPO receptor (EPOR). Because CD34(+) cells represent a heterogeneous cell population, we analyzed individual burst-forming units-erythroid (BFU-E) and nonerythroid colony-forming unit-granulocyte-macrophage colonies for EPO mRNA. Only BFU-E colonies were positive for EPO mRNA. Lysates from pooled BFU-E colonies stained positively for EPO by immunoblotting. To further confirm the intrinsic nature of erythroid EPO, we replaced extrinsic EPO in erythroid colony cultures with EPO-mimicking peptide (EMP). We show EPO expression in the EMP-stimulated BFU-Es at both mRNA and protein levels. Stimulation of bone marrow mononuclear cells (BMMCs) with EMP upregulated EPO expression. Furthermore, we found EPO and EPOR mRNAs as well as EPO protein in K562 cells, a human erythroleukemia cell line. Stimulation of K562 cells with EMP upregulated EPO expression. We suggest that EPO of erythroid origin may have a role in the regulation of erythropoiesis.

Reticular dysgenesis–associated AK2 protects hematopoietic stem and progenitor cell development from oxidative stress

PubMed Central

Rissone, Alberto; Weinacht, Katja Gabriele; la Marca, Giancarlo; Bishop, Kevin; Giocaliere, Elisa; Jagadeesh, Jayashree; Felgentreff, Kerstin; Dobbs, Kerry; Al-Herz, Waleed; Jones, Marypat; Chandrasekharappa, Settara; Kirby, Martha; Wincovitch, Stephen; Simon, Karen Lyn; Itan, Yuval; DeVine, Alex; Schlaeger, Thorsten; Schambach, Axel; Sood, Raman

2015-01-01

Adenylate kinases (AKs) are phosphotransferases that regulate the cellular adenine nucleotide composition and play a critical role in the energy homeostasis of all tissues. The AK2 isoenzyme is expressed in the mitochondrial intermembrane space and is mutated in reticular dysgenesis (RD), a rare form of severe combined immunodeficiency (SCID) in humans. RD is characterized by a maturation arrest in the myeloid and lymphoid lineages, leading to early onset, recurrent, and overwhelming infections. To gain insight into the pathophysiology of RD, we studied the effects of AK2 deficiency using the zebrafish model and induced pluripotent stem cells (iPSCs) derived from fibroblasts of an RD patient. In zebrafish, Ak2 deficiency affected hematopoietic stem and progenitor cell (HSPC) development with increased oxidative stress and apoptosis. AK2-deficient iPSCs recapitulated the characteristic myeloid maturation arrest at the promyelocyte stage and demonstrated an increased AMP/ADP ratio, indicative of an energy-depleted adenine nucleotide profile. Antioxidant treatment rescued the hematopoietic phenotypes in vivo in ak2 mutant zebrafish and restored differentiation of AK2-deficient iPSCs into mature granulocytes. Our results link hematopoietic cell fate in AK2 deficiency to cellular energy depletion and increased oxidative stress. This points to the potential use of antioxidants as a supportive therapeutic modality for patients with RD. PMID:26150473

C/EBPβ in bone marrow is essential for diet induced inflammation, cholesterol balance, and atherosclerosis.

PubMed

Rahman, Shaikh M; Baquero, Karalee C; Choudhury, Mahua; Janssen, Rachel C; de la Houssaye, Becky A; Sun, Ming; Miyazaki-Anzai, Shinobu; Wang, Shu; Moustaid-Moussa, Naima; Miyazaki, Makoto; Friedman, Jacob E

2016-07-01

Atherosclerosis is both a chronic inflammatory disease and a lipid metabolism disorder. C/EBPβ is well documented for its role in the development of hematopoietic cells and integration of lipid metabolism. However, C/EBPβ's role in atherosclerotic progression has not been examined. We assessed the impact of hematopoietic CEBPβ deletion in ApoE(-/-) mice on hyperlipidemia, inflammatory responses and lesion formation in the aorta. ApoE(-/-) mice were reconstituted with bone marrow cells derived from either WT or C/EBPβ(-/-) mice and placed on low fat or high fat/high cholesterol diet for 11 weeks. Hematopoietic C/EBPβ deletion in ApoE(-/-) mice reduced blood and hepatic lipids and gene expression of hepatic stearoyl CoA desaturase 1 and fatty acid synthase while expression of ATP binding cassette transporter G1, cholesterol 7-alpha-hydroxylase, and liver X receptor alpha genes were significantly increased. ApoE(-/-) mice reconstituted with C/EBPβ(-/-) bone marrow cells also significantly reduced blood cytokine levels and reduced lesion area in aortic sinuses compared with ApoE(-/-) mice reconstituted with WT bone marrow cells. Silencing of C/EBPβ in RAW264.7 macrophage cells prevented oxLDL-mediated foam cell formation and inflammatory cytokine secretion in conditioned medium. C/EBPβ in hematopoietic cells is crucial to regulate diet-induced inflammation, hyperlipidemia and atherosclerosis development. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Inhibition of T Cell Protein Tyrosine Phosphatase Enhances Interleukin-18-Dependent Hematopoietic Stem Cell Expansion

PubMed Central

Bourdeau, Annie; Trop, Sébastien; Doody, Karen M; Dumont, Daniel J; Tremblayef, Michel L

2013-01-01

The clinical application of hematopoietic progenitor cell-based therapies for the treatment of hematological diseases is hindered by current protocols, which are cumbersome and have limited efficacy to augment the progenitor cell pool. We report that inhibition of T-cell protein tyrosine phosphatase (TC-PTP), an enzyme involved in the regulation of cytokine signaling, through gene knockout results in a ninefold increase in the number of hematopoietic progenitors in murine bone marrow (BM). This effect could be reproduced using a short (48 hours) treatment with a pharmacological inhibitor of TC-PTP in murine BM, as well as in human BM, peripheral blood, and cord blood. We also demonstrate that the ex vivo use of TC-PTP inhibitor only provides a temporary effect on stem cells and did not alter their capacity to reconstitute all hematopoietic components in vivo. We establish that one of the mechanisms whereby inhibition of TC-PTP mediates its effects involves the interleukin-18 (IL-18) signaling pathway, leading to increased production of IL-12 and interferon-gamma by progenitor cells. Together, our results reveal a previously unrecognized role for IL-18 in contributing to the augmentation of the stem cell pool and provide a novel and simple method to rapidly expand progenitor cells from a variety of sources using a pharmacological compound. Stem Cells 2013;31:293–304 PMID:23135963

Hematopoietic-to-mesenchymal transition of adipose tissue macrophages is regulated by integrin β1 and fabricated fibrin matrices

PubMed Central

Majka, Susan M.; Kohrt, Wendy M.; Miller, Heidi L.; Sullivan, Timothy M.; Klemm, Dwight J.

2017-01-01

ABSTRACT Some bona fide adult adipocytes arise de novo from a bone marrow-derived myeloid lineage. These studies further demonstrate that adipose tissue stroma contains a resident population of myeloid cells capable of adipocyte and multilineage mesenchymal differentiation. These resident myeloid cells lack hematopoietic markers and express mesenchymal and progenitor cell markers. Because bone marrow mesenchymal progenitor cells have not been shown to enter the circulation, we hypothesized that myeloid cells acquire mesenchymal differentiation capacity in adipose tissue. We fabricated a 3-dimensional fibrin matrix culture system to define the adipose differentiation potential of adipose tissue-resident myeloid subpopulations, including macrophages, granulocytes and dendritic cells. Our data show that multilineage mesenchymal potential was limited to adipose tissue macrophages, characterized by the acquisition of adipocyte, osteoblast, chondrocyte and skeletal muscle myocyte phenotypes. Fibrin hydrogel matrices stimulated macrophage loss of hematopoietic cell lineage determinants and the expression of mesenchymal and progenitor cell markers, including integrin β1. Ablation of integrin β1 in macrophages inhibited adipocyte specification. Therefore, some bona fide adipocytes are specifically derived from adipose tissue-resident macrophages via an integrin β1-dependent hematopoietic-to-mesenchymal transition, whereby they become capable of multipotent mesenchymal differentiation. The requirement for integrin β1 highlights this molecule as a potential target for controlling the production of marrow-derived adipocytes and their contribution to adipose tissue development and function. PMID:28441086

Thrombomodulin Contributes to Gamma Tocotrienol-Mediated Lethality Protection and Hematopoietic Cell Recovery in Irradiated Mice

PubMed Central

Pathak, Rupak; Shao, Lijian; Ghosh, Sanchita P.; Zhou, Daohong; Boerma, Marjan; Weiler, Hartmut; Hauer-Jensen, Martin

2015-01-01

Systemic administration of recombinant thrombomodulin (TM) confers radiation protection partly by accelerating hematopoietic recovery. The uniquely potent radioprotector gamma tocotrienol (GT3), in addition to being a strong antioxidant, inhibits the enzyme hydroxy-methyl-glutaryl-coenzyme A reductase (HMGCR) and thereby likely modulates the expression of TM. We hypothesized that the mechanism underlying the exceptional radioprotective properties of GT3 partly depends on the presence of endothelial TM. In vitro studies confirmed that ionizing radiation suppresses endothelial TM (about 40% at 4 hr after 5 Gy γ-irradiation) and that GT3 induces TM expression (about 2 fold at the mRNA level after 5 μM GT3 treatment for 4 hr). In vivo survival studies showed that GT3 was significantly more effective as a radioprotector in TM wild type (TM+/+) mice than in mice with low TM function (TMPro/-). After exposure to 9 Gy TBI, GT3 pre-treatment conferred 85% survival in TM+/+ mice compared to only 50% in TMPro/-. Thus, GT3-mediated radiation lethality protection is partly dependent on endothelial TM. Significant post-TBI recovery of hematopoietic cells, particularly leukocytes, was observed in TM+/+ mice (p = 0.003), but not in TMPro/- mice, despite the fact that GT3 induced higher levels of granulocyte colony stimulating factor (G-CSF) in TMPro/- mice (p = 0.0001). These data demonstrate a critical, G-CSF-independent, role for endothelial TM in GT3-mediated lethality protection and hematopoietic recovery after exposure to TBI and may point to new strategies to enhance the efficacy of current medical countermeasures in radiological/nuclear emergencies. PMID:25860286

RUNX2 Mediates Plasmacytoid Dendritic Cell Egress from the Bone Marrow and Controls Viral Immunity.

PubMed

Chopin, Michaël; Preston, Simon P; Lun, Aaron T L; Tellier, Julie; Smyth, Gordon K; Pellegrini, Marc; Belz, Gabrielle T; Corcoran, Lynn M; Visvader, Jane E; Wu, Li; Nutt, Stephen L

2016-04-26

Plasmacytoid dendritic cells (pDCs) represent a unique immune cell type that responds to viral nucleic acids through the rapid production of type I interferons. Within the hematopoietic system, the transcription factor RUNX2 is exclusively expressed in pDCs and is required for their peripheral homeostasis. Here, we show that RUNX2 plays an essential role in promoting pDC localization and function. RUNX2 is required for the appropriate expression of the integrin-mediated adhesion machinery, as well as for the down-modulation of the chemokine receptor CXCR4, which allows pDC egress into the circulation. RUNX2 also facilitates the robust response to viral infection through the control of IRF7, the major regulator of type I interferon production. Mice lacking one copy of Runx2 have reduced numbers of peripheral pDCs and IFN-α expression, which might contribute to the reported difficulties of individuals with cleidocranial dysplasia, who are haploinsufficient for RUNX2, to clear viral infections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

USP10 Is an Essential Deubiquitinase for Hematopoiesis and Inhibits Apoptosis of Long-Term Hematopoietic Stem Cells.

PubMed

Higuchi, Masaya; Kawamura, Hiroki; Matsuki, Hideaki; Hara, Toshifumi; Takahashi, Masahiko; Saito, Suguru; Saito, Kousuke; Jiang, Shuying; Naito, Makoto; Kiyonari, Hiroshi; Fujii, Masahiro

2016-12-13

Self-renewal, replication, and differentiation of hematopoietic stem cells (HSCs) are regulated by cytokines produced by niche cells in fetal liver and bone marrow. HSCs must overcome stresses induced by cytokine deprivation during normal development. In this study, we found that ubiquitin-specific peptidase 10 (USP10) is a crucial deubiquitinase for mouse hematopoiesis. All USP10 knockout (KO) mice died within 1 year because of bone marrow failure with pancytopenia. Bone marrow failure in these USP10-KO mice was associated with remarkable reductions of long-term HSCs (LT-HSCs) in bone marrow and fetal liver. Such USP10-KO fetal liver exhibited enhanced apoptosis of hematopoietic stem/progenitor cells (HSPCs) including LT-HSCs but not of lineage-committed progenitor cells. Transplantation of USP10-competent bone marrow cells into USP10-KO mice reconstituted multilineage hematopoiesis. These results suggest that USP10 is an essential deubiquitinase in hematopoiesis and functions by inhibiting apoptosis of HSPCs including LT-HSCs. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Essential roles for Cdx in murine primitive hematopoiesis.

PubMed

Brooke-Bisschop, Travis; Savory, Joanne G A; Foley, Tanya; Ringuette, Randy; Lohnes, David

2017-02-15

The Cdx transcription factors play essential roles in primitive hematopoiesis in the zebrafish where they exert their effects, in part, through regulation of hox genes. Defects in hematopoiesis have also been reported in Cdx mutant murine embryonic stem cell models, however, to date no mouse model reflecting the zebrafish Cdx mutant hematopoietic phenotype has been described. This is likely due, in part, to functional redundancy among Cdx members and the early lethality of Cdx2 null mutants. To circumvent these limitations, we used Cre-mediated conditional deletion to assess the impact of concomitant loss of Cdx1 and Cdx2 on murine primitive hematopoiesis. We found that Cdx1/Cdx2 double mutants exhibited defects in primitive hematopoiesis and yolk sac vasculature concomitant with reduced expression of several genes encoding hematopoietic transcription factors including Scl/Tal1. Chromatin immunoprecipitation analysis revealed that Scl was occupied by Cdx2 in vivo, and Cdx mutant hematopoietic yolk sac differentiation defects could be rescued by expression of exogenous Scl. These findings demonstrate critical roles for Cdx members in murine primitive hematopoiesis upstream of Scl. Copyright © 2017 Elsevier Inc. All rights reserved.

Enhanced Ex Vivo Expansion of Human Hematopoietic Progenitors on Native and Spin Coated Acellular Matrices Prepared from Bone Marrow Stromal Cells

PubMed Central

Wasnik, Samiksha; Kantipudi, Suma; Kirkland, Mark A.; Pande, Gopal

2016-01-01

The extracellular microenvironment in bone marrow (BM) is known to regulate the growth and differentiation of hematopoietic stem and progenitor cells (HSPC). We have developed cell-free matrices from a BM stromal cell line (HS-5), which can be used as substrates either in native form or as tissue engineered coatings, for the enhanced ex vivo expansion of umbilical cord blood (UCB) derived HSPC. The physicochemical properties (surface roughness, thickness, and uniformity) of native and spin coated acellular matrices (ACM) were studied using scanning and atomic force microscopy (SEM and AFM). Lineage-specific expansion of HSPC, grown on these substrates, was evaluated by immunophenotypic (flow cytometry) and functional (colony forming) assays. Our results show that the most efficient expansion of lineage-specific HSPC occurred on spin coated ACM. Our method provides an improved protocol for ex vivo HSPC expansion and it offers a system to study the in vivo roles of specific molecules in the hematopoietic niche that influence HSPC expansion. PMID:26981135

In vivo imaging of transplanted hematopoietic stem and progenitor cells in mouse calvarium bone marrow

PubMed Central

Lo Celso, Cristina; Lin, Charles P; Scadden, David T

2011-01-01

In vivo imaging of transplanted hematopoietic stem and progenitor cells (HSPCs) was developed to investigate the relationship between HSPCs and components of their microenvironment in the bone marrow. In particular, it allows a direct observation of the behavior of hematopoietic cells during the first few days after transplantation, when the critical events in homing and early engraftment are occurring. By directly imaging these events in living animals, this method permits a detailed assessment of functions previously evaluated by crude assessments of cell counts (homing) or after prolonged periods (engraftment). This protocol offers a new means of investigating the role of cell-intrinsic and cell-extrinsic molecular regulators of hematopoiesis during the early stages of transplantation, and it is the first to allow the study of cell-cell interactions within the bone marrow in three dimensions and in real time. In this paper, we describe how to isolate, label and inject HSPCs, as well as how to perform calvarium intravital microscopy and analyze the resulting images. A typical experiment can be performed and analyzed in ~1 week. PMID:21212779

Bag1 is essential for differentiation and survival of hematopoietic and neuronal cells.

PubMed

Götz, Rudolf; Wiese, Stefan; Takayama, Shinichi; Camarero, Guadalupe C; Rossoll, Wilfried; Schweizer, Ulrich; Troppmair, Jakob; Jablonka, Sibylle; Holtmann, Bettina; Reed, John C; Rapp, Ulf R; Sendtner, Michael

2005-09-01

Bag1 is a cochaperone for the heat-shock protein Hsp70 that interacts with C-Raf, B-Raf, Akt, Bcl-2, steroid hormone receptors and other proteins. Here we use targeted gene disruption in mice to show that Bag1 has an essential role in the survival of differentiating neurons and hematopoietic cells. Cells of the fetal liver and developing nervous system in Bag1-/- mice underwent massive apoptosis. Lack of Bag1 did not disturb the primary function of Akt or Raf, as phosphorylation of the forkhead transcription factor FKHR and activation of extracellular signal-regulated kinase (Erk)-1/2 were not affected. However, the defect was associated with the disturbance of a tripartite complex formed by Akt, B-Raf and Bag1, in addition to the absence of Bad phosphorylation at Ser136. We also observed reduced expression of members of the inhibitor of apoptosis (IAP) family. Our data show that Bag1 is a physiological mediator of extracellular survival signals linked to the cellular mechanisms that prevent apoptosis in hematopoietic and neuronal progenitor cells.

Fancb deficiency impairs hematopoietic stem cell function

PubMed Central

Du, Wei; Amarachintha, Surya; Erden, Ozlem; Wilson, Andrew; Meetei, Amom Ruhikanta; Andreassen, Paul R.; Namekawa, Satoshi H.; Pang, Qishen

2015-01-01

Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, variable congenital malformations and a predisposition to malignancies. FANCB (also known as FAAP95), is the only X-linked FA gene discovered thus far. In the present study, we investigated hematopoiesis in adult Fancb deficient (Fancb−/y) mice and found that Fancb−/y mice have decreased hematopoietic stem cell (HSC) quiescence accompanied by reduced progenitor activity in vitro and reduced repopulating capacity in vivo. Like other FA mouse models previously reported, the hematopoietic system of Fancb−/y mice is hypersensitive to DNA cross-linking agent mitomycin C (MMC), which induces bone marrow failure in Fancb−/y mice. Furthermore, Fancb−/y BM exhibits slower recovery kinetics and less tolerance to myelotoxic stress induced by 5-fluorouracil than wild-type littermates. RNA-seq analysis reveals altered expression of genes involved in HSC function and cell cycle regulation in Fancb−/y HSC and progenitor cells. Thus, this Fancb−/y mouse model provides a novel approach for studying the critical role of the FA pathway not only in germ cell development but also in the maintenance of HSC function. PMID:26658157

"Nutrient-sensing" and self-renewal: O-GlcNAc in a new role.

PubMed

Sharma, Nikita S; Saluja, Ashok K; Banerjee, Sulagna

2018-06-01

Whether embryonic, hematopoietic or cancer stem cells, this metabolic reprogramming is dependent on the nutrient-status and bioenergetic pathways that is influenced by the micro-environmental niches like hypoxia. Thus, the microenvironment plays a vital role in determining the stem cell fate by inducing metabolic reprogramming. Under the influence of the microenvironment, like hypoxia, the stem cells have increased glucose and glutamine uptake which result in activation of hexosamine biosynthesis pathway (HBP) and increased O-GlcNAc Transferase (OGT). The current review is focused on understanding how HBP, a nutrient-sensing pathway (that leads to increased OGT activity) is instrumental in regulating self-renewal not only in embryonic and hematopoietic stem cells (ESC/HSC) but also in cancer stem cells.

The zebrafish gene cloche acts upstream of a flk-1 homologue to regulate endothelial cell differentiation.

PubMed

Liao, W; Bisgrove, B W; Sawyer, H; Hug, B; Bell, B; Peters, K; Grunwald, D J; Stainier, D Y

1997-01-01

The zebrafish cloche mutation affects both the endothelial and hematopoietic lineages at a very early stage (Stainier, D. Y. R., Weinstein, B. M., Detrich, H. W., Zon, L. I. and Fishman, M. C. (1995). Development 121, 3141-3150). The most striking vascular phenotype is the absence of endocardial cells from the heart. Microscopic examination of mutant embryos reveals the presence of endothelial-like cells in the lower trunk and tail regions while head vessels appear to be missing, indicating a molecular diversification of the endothelial lineage. Cell transplantation experiments show that cloche acts cell-autonomously within the endothelial lineage. To analyze further the role of cloche in regulating endothelial cell differentiation, we have examined the expression of flk-1 and tie, two receptor tyrosine kinase genes expressed early and sequentially in the endothelial lineage. In wild-type fish, flk-1-positive cells are found throughout the embryo and differentiate to form the nascent vasculature. In cloche mutants, flk-1-positive cells are found only in the lower trunk and tail regions, and this expression is delayed as compared to wild-type. Unlike the flk-1-positive cells in wild-type embryos, those in cloche mutants do not go on to express tie, suggesting that their differentiation is halted at an early stage. We also find that the cloche mutation is not linked to flk-1. These data indicate that cloche affects the differentiation of all endothelial cells and that it acts at a very early stage, either by directly regulating flk-1 expression or by controlling the differentiation of cells that normally develop to express flk-1. cloche mutants also have a blood deficit and their hematopoietic tissues show no expression of the hematopoietic transcription factor genes GATA-1 or GATA-2 at early stages. Because the appearance of distinct levels of flk-1 expression is delayed in cloche mutants, we examined GATA-1 expression at late embryonic stages and found some blood cell differentiation that appears to be limited to the region lined by the flk-1-expressing cells. The spatial restriction of blood in the ventroposterior-most region of cloche mutant embryos may be indicative of a ventral source of signal(s) controlling hematopoietic differentiation. In addition, the restricted colocalization of blood and endothelium in cloche mutants suggests that important interactions occur between these two lineages during normal development.

The Second Pediatric Blood and Marrow Transplant Consortium International Consensus Conference on Late Effects after Pediatric Hematopoietic Cell Transplantation (HCT): Defining the Unique Late Effects of Children undergoing HCT for Immune Deficiencies, Inherited Marrow Failure Disorders, and Hemoglobinopathies

PubMed Central

Dietz, Andrew C.; Duncan, Christine N.; Alter, Blanche P.; Bresters, Dorine; Cowan, Morton J.; Notarangelo, Luigi; Rosenberg, Philip S.; Shenoy, Shalini; Skinner, Roderick; Walters, Mark C.; Wagner, John; Baker, K. Scott; Pulsipher, Michael A.

2016-01-01

An international consensus conference sponsored by the Pediatric Blood and Marrow Transplant consortium entitled, “Late Effects Screening and Recommendations Following Allogeneic Hematopoietic Cell Transplant for Immune Deficiency and Non-malignant Hematologic Disease was held in Minneapolis, Minnesota on May 10–11, 2016. The purpose of the conference was to address the unmet need for a greater understanding of and the screening for long-term complications in the growing population of survivors of transplantation for nonmalignant disorders. The conference focused on transplantation for hemoglobinopathy, immune deficiency, and inherited bone marrow syndromes. A multidisciplinary group of experts in the disease areas and transplant late effects presented the current state of understanding of how the underlying disease, pretransplant therapies, and transplant related factors uniquely interact to influence the development of late toxicities. Recommendations were put forth by the group for the late effects screening of survivors of transplantation for these non-malignant disorders. The findings and recommendations that came from this conference will be presented in a series of six additional manuscripts in the upcoming months. In this manuscript we explore the need for screening practices specific to the survivors of transplantation for non-malignant diseases and the metholodologic challenges associated with the study of these patients. PMID:27737772

Megakaryocytes regulate hematopoietic stem cell quiescence through CXCL4 secretion.

PubMed

Bruns, Ingmar; Lucas, Daniel; Pinho, Sandra; Ahmed, Jalal; Lambert, Michele P; Kunisaki, Yuya; Scheiermann, Christoph; Schiff, Lauren; Poncz, Mortimer; Bergman, Aviv; Frenette, Paul S

2014-11-01

In the bone marrow, hematopoietic stem cells (HSCs) lodge in specialized microenvironments that tightly control the proliferative state of HSCs to adapt to the varying needs for replenishment of blood cells while also preventing HSC exhaustion. All putative niche cells suggested thus far have a nonhematopoietic origin. Thus, it remains unclear how feedback from mature cells is conveyed to HSCs to adjust their proliferation. Here we show that megakaryocytes (MKs) can directly regulate HSC pool size in mice. Three-dimensional whole-mount imaging revealed that endogenous HSCs are frequently located adjacent to MKs in a nonrandom fashion. Selective in vivo depletion of MKs resulted in specific loss of HSC quiescence and led to a marked expansion of functional HSCs. Gene expression analyses revealed that MKs are the source of chemokine C-X-C motif ligand 4 (CXCL4, also named platelet factor 4 or PF4) in the bone marrow, and we found that CXCL4 regulates HSC cell cycle activity. CXCL4 injection into mice resulted in a reduced number of HSCs because of their increased quiescence. By contrast, Cxcl4(-/-) mice exhibited an increased number of HSCs and increased HSC proliferation. Combined use of whole-mount imaging and computational modeling was highly suggestive of a megakaryocytic niche capable of independently influencing HSC maintenance by regulating quiescence. These results indicate that a terminally differentiated cell type derived from HSCs contributes to the HSC niche, directly regulating HSC behavior.

The Meaning of Disease and Spiritual Responses to Stressors in Adults With Acute Leukemia Undergoing Hematopoietic Stem Cell Transplantation.

PubMed

Farsi, Zahra

2015-12-01

Some studies have shown that patients with cancer may experience significant spiritual distress as well as spiritual growth, that there is a positive association between spirituality and coping, and that positive religious coping predicts enhanced health outcomes. This study was designed to help explain how the meaning of disease and spiritual responses to threatening stressors influence the final experiential outcomes of adults with leukemia undergoing hematopoietic stem cell transplantation in Iran. This grounded theory study conducted in-depth interviews between 2009 and 2011 on 10 adults in Iran with leukemia undergoing hematopoietic stem cell transplantation. Recorded audio interviews were transcribed verbatim in Persian and coded and analyzed using Corbin and Strauss (2008)'s approach. Main categories that emerged from data included "experiencing the meaning of cancer"; "changing perceptions of death, life and health"; and "moving toward perfection and sublimity." "Finding meaning" was the main concept that defined the final outcome of the experience of participants. Understanding the meaning to patients of disease and treatments may help healthcare providers better appreciate the patients' perspective and improve the physician-patient relationship. Nurses are well positioned to play a decisive role in helping patients cope effectively with their treatment process and in helping ensure positive outcomes for treatments through their helping patients find the unique meaning of their experience.

Functional dissection of hematopoietic stem cell populations with a stemness-monitoring system based on NS-GFP transgene expression.

PubMed

Ali, Mohamed A E; Fuse, Kyoko; Tadokoro, Yuko; Hoshii, Takayuki; Ueno, Masaya; Kobayashi, Masahiko; Nomura, Naho; Vu, Ha Thi; Peng, Hui; Hegazy, Ahmed M; Masuko, Masayoshi; Sone, Hirohito; Arai, Fumio; Tajima, Atsushi; Hirao, Atsushi

2017-09-12

Hematopoietic stem cells (HSCs) in a steady state can be efficiently purified by selecting for a combination of several cell surface markers; however, such markers do not consistently reflect HSC activity. In this study, we successfully enriched HSCs with a unique stemness-monitoring system using a transgenic mouse in which green florescence protein (GFP) is driven by the promoter/enhancer region of the nucleostemin (NS) gene. We found that the phenotypically defined long-term (LT)-HSC population exhibited the highest level of NS-GFP intensity, whereas NS-GFP intensity was strongly downregulated during differentiation in vitro and in vivo. Within the LT-HSC population, NS-GFP high cells exhibited significantly higher repopulating capacity than NS-GFP low cells. Gene expression analysis revealed that nine genes, including Vwf and Cdkn1c (p57), are highly expressed in NS-GFP high cells and may represent a signature of HSCs, i.e., a stemness signature. When LT-HSCs suffered from remarkable stress, such as transplantation or irradiation, NS-GFP intensity was downregulated. Finally, we found that high levels of NS-GFP identified HSC-like cells even among CD34 + cells, which have been considered progenitor cells without long-term reconstitution ability. Thus, high NS-GFP expression represents stem cell characteristics in hematopoietic cells, making this system useful for identifying previously uncharacterized HSCs.

CD62L− memory T cells enhance T-cell regeneration after allogeneic stem cell transplantation by eliminating host resistance in mice

PubMed Central

Zhang, Jifeng; Barefoot, Brice E.; Mo, Wenjian; Deoliveira, Divino; Son, Jessica; Cui, Xiuyu; Ramsburg, Elizabeth

2012-01-01

A major challenge in allogeneic hematopoietic cell transplantation is how to transfer T-cell immunity without causing graft-versus-host disease (GVHD). Effector memory T cells (CD62L−) are a cell subset that can potentially address this challenge because they do not induce GVHD. Here, we investigated how CD62L− T cells contributed to phenotypic and functional T-cell reconstitution after transplantation. On transfer into allogeneic recipients, CD62L− T cells were activated and expressed multiple cytokines and cytotoxic molecules. CD62L− T cells were able to deplete host radioresistant T cells and facilitate hematopoietic engraftment, resulting in enhanced de novo T-cell regeneration. Enhanced functional immune reconstitution was demonstrated in CD62L− T-cell recipients using a tumor and an influenza virus challenge model. Even though CD62L− T cells are able to respond to alloantigens and deplete host radioresistant immune cells in GVHD recipients, alloreactive CD62L− T cells lost the reactivity over time and were eventually tolerant to alloantigens as a result of prolonged antigen exposure, suggesting a mechanism by which CD62L− T cells were able to eliminate host resistance without causing GVHD. These data further highlight the unique characteristics of CD62L− T cells and their potential applications in clinical hematopoietic cell transplantation. PMID:22596261

A human bone marrow mesodermal-derived cell population with hemogenic potential.

PubMed

Mokhtari, Saloomeh; Colletti, Evan; Yin, Weihong; Sanada, Chad; Lamar, Zanetta; Simmons, Paul J; Walker, Steven; Bishop, Colin; Atala, Anthony; Zanjani, Esmail D; Porada, Christopher D; Almeida-Porada, Graça

2018-02-02

The presence, within the human bone marrow, of cells with both endothelial and hemogenic potential has been controversial. Herein, we identify, within the human fetal bone marrow, prior to establishment of hematopoiesis, a unique APLNR+, Stro-1+ cell population, co-expressing markers of early mesodermal precursors and/or hemogenic endothelium. In adult marrow, cells expressing similar markers are also found, but at very low frequency. These adult-derived cells can be extensively culture expanded in vitro without loss of potential, they preserve a biased hemogenic transcriptional profile, and, upon in vitro induction with OCT4, assume a hematopoietic phenotype. In vivo, these cells, upon transplantation into a fetal microenvironment, contribute to the vasculature, and generate hematopoietic cells that provide multilineage repopulation upon serial transplantation. The identification of this human somatic cell population provides novel insights into human ontogenetic hematovascular potential, which could lead to a better understanding of, and new target therapies for, malignant and nonmalignant hematologic disorders.

Transient loading of CD34+ hematopoietic progenitor cells with polystyrene nanoparticles.

PubMed

Deville, Sarah; Hadiwikarta, Wahyu Wijaya; Smisdom, Nick; Wathiong, Bart; Ameloot, Marcel; Nelissen, Inge; Hooyberghs, Jef

2017-01-01

CD34 + hematopoietic progenitor cells (HPCs) offer great opportunities to develop new treatments for numerous malignant and non-malignant diseases. Nanoparticle (NP)-based strategies can further enhance this potential, and therefore a thorough understanding of the loading behavior of HPCs towards NPs is essential for a successful application. The present study focusses on the interaction kinetics of 40 nm sized carboxylated polystyrene (PS) NPs with HPCs. Interestingly, a transient association of the NPs with HPCs is observed, reaching a maximum within 1 hour and declining afterwards. This behavior is not seen in dendritic cells (CD34-DCs) differentiated from HPCs, which display a monotonic increase in NP load. We demonstrate that this transient interaction requires an energy-dependent cellular process, suggesting active loading and release of NPs by HPCs. This novel observation offers a unique approach to transiently equip HPCs. A simple theoretical approach modeling the kinetics of NP loading and release is presented, contributing to a framework of describing this phenomenon.

Infusion of freshly isolated autologous bone marrow derived mononuclear cells prevents endotoxin-induced lung injury in an ex-vivo perfused swine model

PubMed Central

2013-01-01

Introduction The acute respiratory distress syndrome (ARDS), affects up to 150,000 patients per year in the United States. We and other groups have demonstrated that bone marrow derived mesenchymal stromal stem cells prevent ARDS induced by systemic and local administration of endotoxin (lipopolysaccharide (LPS)) in mice. Methods A study was undertaken to determine the effects of the diverse populations of bone marrow derived cells on the pathophysiology of ARDS, using a unique ex-vivo swine preparation, in which only the ventilated lung and the liver are perfused with autologous blood. Six experimental groups were designated as: 1) endotoxin alone, 2) endotoxin + total fresh whole bone marrow nuclear cells (BMC), 3) endotoxin + non-hematopoietic bone marrow cells (CD45 neg), 4) endotoxin + hematopoietic bone marrow cells (CD45 positive), 5) endotoxin + buffy coat and 6) endotoxin + in vitro expanded swine CD45 negative adherent allogeneic bone marrow cells (cultured CD45neg). We measured at different levels the biological consequences of the infusion of the different subsets of cells. The measured parameters were: pulmonary vascular resistance (PVR), gas exchange (PO2), lung edema (lung wet/dry weight), gene expression and serum concentrations of the pro-inflammatory cytokines IL-1β, TNF-α and IL-6. Results Infusion of freshly purified autologous total BMCs, as well as non-hematopoietic CD45(-) bone marrow cells significantly reduced endotoxin-induced pulmonary hypertension and hypoxemia and reduced the lung edema. Also, in the groups that received BMCs and cultured CD45neg we observed a decrease in the levels of IL-1β and TNF-α in plasma. Infusion of hematopoietic CD45(+) bone marrow cells or peripheral blood buffy coat cells did not protect against LPS-induced lung injury. Conclusions We conclude that infusion of freshly isolated autologous whole bone marrow cells and the subset of non-hematopoietic cells can suppress the acute humoral and physiologic responses induced by endotoxemia by modulating the inflammatory response, mechanisms that do not involve engraftment or trans-differentiation of the cells. These observations may have important implications for the design of future cell therapies for ARDS. PMID:23497755

SHIP1-expressing mesenchymal stem cells regulate hematopoietic stem cell homeostasis and lineage commitment during aging.

PubMed

Iyer, Sonia; Brooks, Robert; Gumbleton, Matthew; Kerr, William G

2015-05-01

Hematopoietic stem cell (HSC) self-renewal and lineage choice are subject to intrinsic control. However, this intrinsic regulation is also impacted by external cues provided by niche cells. There are multiple cellular components that participate in HSC support with the mesenchymal stem cell (MSC) playing a pivotal role. We had previously identified a role for SH2 domain-containing inositol 5'-phosphatase-1 (SHIP1) in HSC niche function through analysis of mice with germline or induced SHIP1 deficiency. In this study, we show that the HSC compartment expands significantly when aged in a niche that contains SHIP1-deficient MSC; however, this expanded HSC compartment exhibits a strong bias toward myeloid differentiation. In addition, we show that SHIP1 prevents chronic G-CSF production by the aging MSC compartment. These findings demonstrate that intracellular signaling by SHIP1 in MSC is critical for the control of HSC output and lineage commitment during aging. These studies increase our understanding of how myeloid bias occurs in aging and thus could have implications for the development of myeloproliferative disease in aging.

Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice.

PubMed

Wang, Jiapeng; Li, Zhaomin; He, Yongzheng; Pan, Feng; Chen, Shi; Rhodes, Steven; Nguyen, Lihn; Yuan, Jin; Jiang, Li; Yang, Xianlin; Weeks, Ophelia; Liu, Ziyue; Zhou, Jiehao; Ni, Hongyu; Cai, Chen-Leng; Xu, Mingjiang; Yang, Feng-Chun

2014-01-23

ASXL1 is mutated/deleted with high frequencies in multiple forms of myeloid malignancies, and its alterations are associated with poor prognosis. De novo ASXL1 mutations cause Bohring-Opitz syndrome characterized by multiple congenital malformations. We show that Asxl1 deletion in mice led to developmental abnormalities including dwarfism, anophthalmia, and 80% embryonic lethality. Surviving Asxl1(-/-) mice lived for up to 42 days and developed features of myelodysplastic syndrome (MDS), including dysplastic neutrophils and multiple lineage cytopenia. Asxl1(-/-) mice had a reduced hematopoietic stem cell (HSC) pool, and Asxl1(-/-) HSCs exhibited decreased hematopoietic repopulating capacity, with skewed cell differentiation favoring granulocytic lineage. Asxl1(+/-) mice also developed mild MDS-like disease, which could progress to MDS/myeloproliferative neoplasm, demonstrating a haploinsufficient effect of Asxl1 in the pathogenesis of myeloid malignancies. Asxl1 loss led to an increased apoptosis and mitosis in Lineage(-)c-Kit(+) (Lin(-)c-Kit(+)) cells, consistent with human MDS. Furthermore, Asxl1(-/-) Lin(-)c-Kit(+) cells exhibited decreased global levels of H3K27me3 and H3K4me3 and altered expression of genes regulating apoptosis (Bcl2, Bcl2l12, Bcl2l13). Collectively, we report a novel ASXL1 murine model that recapitulates human myeloid malignancies, implying that Asxl1 functions as a tumor suppressor to maintain hematopoietic cell homeostasis. Future work is necessary to clarify the contribution of microenvironment to the hematopoietic phenotypes observed in the constitutional Asxl1(-/-) mice.

Prostaglandin E2 increases hematopoietic stem cell survival and accelerates hematopoietic recovery after radiation injury

PubMed Central

Porter, Rebecca L.; Georger, Mary; Bromberg, Olga; McGrath, Kathleen E.; Frisch, Benjamin J.; Becker, Michael W.; Calvi, Laura M.

2013-01-01

Hematopoietic stem and progenitor cells (HSPCs), which continuously maintain all mature blood cells, are regulated within the marrow microenvironment. We previously reported that pharmacologic treatment of naïve mice with prostaglandin E2 (PGE2) expands HSPCs. However, the cellular mechanisms mediating this expansion remain unknown. Here we demonstrate that PGE2 treatment in naïve mice inhibits apoptosis of HSPCs without changing their proliferation rate. In a murine model of sub-lethal total body irradiation (TBI), in which HSPCs are rapidly lost, treatment with a long-acting PGE2 analogue (dmPGE2) reversed the apoptotic program initiated by TBI. dmPGE2 treatment in vivo decreased the loss of functional HSPCs following radiation injury, as demonstrated both phenotypically and by their increased reconstitution capacity. The antiapoptotic effect of dmPGE2 on HSPCs did not impair their ability to differentiate in vivo, resulting instead in improved hematopoietic recovery after TBI. dmPGE2 also increased microenvironmental cyclooxygenase-2 expression and expanded the α-SMA+ subset of marrow macrophages, thus enhancing the bone marrow microenvironmental response to TBI. Therefore, in vivo treatment with PGE2 analogues may be particularly beneficial to HSPCs in the setting of injury by targeting them both directly and also through their niche. The current data provide rationale for in vivo manipulation of the HSPC pool as a strategy to improve recovery after myelosuppression. PMID:23169593

FGF-23 Is a Negative Regulator of Prenatal and Postnatal Erythropoiesis*

PubMed Central

Coe, Lindsay M.; Madathil, Sangeetha Vadakke; Casu, Carla; Lanske, Beate; Rivella, Stefano; Sitara, Despina

2014-01-01

Abnormal blood cell production is associated with chronic kidney disease (CKD) and cardiovascular disease (CVD). Bone-derived FGF-23 (fibroblast growth factor-23) regulates phosphate homeostasis and bone mineralization. Genetic deletion of Fgf-23 in mice (Fgf-23−/−) results in hypervitaminosis D, abnormal mineral metabolism, and reduced lymphatic organ size. Elevated FGF-23 levels are linked to CKD and greater risk of CVD, left ventricular hypertrophy, and mortality in dialysis patients. However, whether FGF-23 is involved in the regulation of erythropoiesis is unknown. Here we report that loss of FGF-23 results in increased hematopoietic stem cell frequency associated with increased erythropoiesis in peripheral blood and bone marrow in young adult mice. In particular, these hematopoietic changes are also detected in fetal livers, suggesting that they are not the result of altered bone marrow niche alone. Most importantly, administration of FGF-23 in wild-type mice results in a rapid decrease in erythropoiesis. Finally, we show that the effect of FGF-23 on erythropoiesis is independent of the high vitamin D levels in these mice. Our studies suggest a novel role for FGF-23 in erythrocyte production and differentiation and suggest that elevated FGF-23 levels contribute to the pathogenesis of anemia in patients with CKD and CVD. PMID:24509850

Wnt-Mediated Repression via Bipartite DNA Recognition by TCF in the Drosophila Hematopoietic System

PubMed Central

Zhang, Chen U.; Blauwkamp, Timothy A.; Burby, Peter E.; Cadigan, Ken M.

2014-01-01

The Wnt/β-catenin signaling pathway plays many important roles in animal development, tissue homeostasis and human disease. Transcription factors of the TCF family mediate many Wnt transcriptional responses, promoting signal-dependent activation or repression of target gene expression. The mechanism of this specificity is poorly understood. Previously, we demonstrated that for activated targets in Drosophila, TCF/Pangolin (the fly TCF) recognizes regulatory DNA through two DNA binding domains, with the High Mobility Group (HMG) domain binding HMG sites and the adjacent C-clamp domain binding Helper sites. Here, we report that TCF/Pangolin utilizes a similar bipartite mechanism to recognize and regulate several Wnt-repressed targets, but through HMG and Helper sites whose sequences are distinct from those found in activated targets. The type of HMG and Helper sites is sufficient to direct activation or repression of Wnt regulated cis-regulatory modules, and protease digestion studies suggest that TCF/Pangolin adopts distinct conformations when bound to either HMG-Helper site pair. This repressive mechanism occurs in the fly lymph gland, the larval hematopoietic organ, where Wnt/β-catenin signaling controls prohemocytic differentiation. Our study provides a paradigm for direct repression of target gene expression by Wnt/β-catenin signaling and allosteric regulation of a transcription factor by DNA. PMID:25144371

Hematopoietic cell differentiation from embryonic and induced pluripotent stem cells

PubMed Central

2013-01-01

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells. PMID:23796405

Ssb1 and Ssb2 cooperate to regulate mouse hematopoietic stem and progenitor cells by resolving replicative stress.

PubMed

Shi, Wei; Vu, Therese; Boucher, Didier; Biernacka, Anna; Nde, Jules; Pandita, Raj K; Straube, Jasmin; Boyle, Glen M; Al-Ejeh, Fares; Nag, Purba; Jeffery, Jessie; Harris, Janelle L; Bain, Amanda L; Grzelak, Marta; Skrzypczak, Magdalena; Mitra, Abhishek; Dojer, Norbert; Crosetto, Nicola; Cloonan, Nicole; Becherel, Olivier J; Finnie, John; Skaar, Jeffrey R; Walkley, Carl R; Pandita, Tej K; Rowicka, Maga; Ginalski, Krzysztof; Lane, Steven W; Khanna, Kum Kum

2017-05-04

Hematopoietic stem and progenitor cells (HSPCs) are vulnerable to endogenous damage and defects in DNA repair can limit their function. The 2 single-stranded DNA (ssDNA) binding proteins SSB1 and SSB2 are crucial regulators of the DNA damage response; however, their overlapping roles during normal physiology are incompletely understood. We generated mice in which both Ssb1 and Ssb2 were constitutively or conditionally deleted. Constitutive Ssb1/Ssb2 double knockout (DKO) caused early embryonic lethality, whereas conditional Ssb1/Ssb2 double knockout (cDKO) in adult mice resulted in acute lethality due to bone marrow failure and intestinal atrophy featuring stem and progenitor cell depletion, a phenotype unexpected from the previously reported single knockout models of Ssb1 or Ssb2 Mechanistically, cDKO HSPCs showed altered replication fork dynamics, massive accumulation of DNA damage, genome-wide double-strand breaks enriched at Ssb-binding regions and CpG islands, together with the accumulation of R -loops and cytosolic ssDNA. Transcriptional profiling of cDKO HSPCs revealed the activation of p53 and interferon (IFN) pathways, which enforced cell cycling in quiescent HSPCs, resulting in their apoptotic death. The rapid cell death phenotype was reproducible in in vitro cultured cDKO-hematopoietic stem cells, which were significantly rescued by nucleotide supplementation or after depletion of p53. Collectively, Ssb1 and Ssb2 control crucial aspects of HSPC function, including proliferation and survival in vivo by resolving replicative stress to maintain genomic stability. © 2017 by The American Society of Hematology.

Ssb1 and Ssb2 cooperate to regulate mouse hematopoietic stem and progenitor cells by resolving replicative stress

PubMed Central

Vu, Therese; Boucher, Didier; Biernacka, Anna; Nde, Jules; Pandita, Raj K.; Straube, Jasmin; Boyle, Glen M.; Al-Ejeh, Fares; Jeffery, Jessie; Harris, Janelle L.; Bain, Amanda L.; Grzelak, Marta; Skrzypczak, Magdalena; Mitra, Abhishek; Dojer, Norbert; Crosetto, Nicola; Cloonan, Nicole; Becherel, Olivier J.; Finnie, John; Skaar, Jeffrey R.; Walkley, Carl R.; Pandita, Tej K.; Rowicka, Maga; Ginalski, Krzysztof

2017-01-01

Hematopoietic stem and progenitor cells (HSPCs) are vulnerable to endogenous damage and defects in DNA repair can limit their function. The 2 single-stranded DNA (ssDNA) binding proteins SSB1 and SSB2 are crucial regulators of the DNA damage response; however, their overlapping roles during normal physiology are incompletely understood. We generated mice in which both Ssb1 and Ssb2 were constitutively or conditionally deleted. Constitutive Ssb1/Ssb2 double knockout (DKO) caused early embryonic lethality, whereas conditional Ssb1/Ssb2 double knockout (cDKO) in adult mice resulted in acute lethality due to bone marrow failure and intestinal atrophy featuring stem and progenitor cell depletion, a phenotype unexpected from the previously reported single knockout models of Ssb1 or Ssb2. Mechanistically, cDKO HSPCs showed altered replication fork dynamics, massive accumulation of DNA damage, genome-wide double-strand breaks enriched at Ssb-binding regions and CpG islands, together with the accumulation of R-loops and cytosolic ssDNA. Transcriptional profiling of cDKO HSPCs revealed the activation of p53 and interferon (IFN) pathways, which enforced cell cycling in quiescent HSPCs, resulting in their apoptotic death. The rapid cell death phenotype was reproducible in in vitro cultured cDKO-hematopoietic stem cells, which were significantly rescued by nucleotide supplementation or after depletion of p53. Collectively, Ssb1 and Ssb2 control crucial aspects of HSPC function, including proliferation and survival in vivo by resolving replicative stress to maintain genomic stability. PMID:28270450

Temporal Changes in FLT3 ITD Regulation of Stem Cell Self Renewal and Leukemogenesis

DTIC Science & Technology

2016-11-01

JAM is a 661   scholar of the Child Health Research Center for Excellence in Developmental 662   Biology at Washington University (K12-HD076224...SUPPLEMENTARY NOTES 14. ABSTRACT My goal is to understand how mechanisms that regulate normal hematopoietic development can also influence the mutation...pathways) in fetal, neonatal and adult progenitors. STAT5 was activated by FLT3-ITD at all stages of development , but MAPK was activated only in post

Skeleton and Glucose Metabolism: A Bone-Pancreas Loop

PubMed Central

Luce, Vincenza; Ventura, Annamaria; Colucci, Silvia; Cavallo, Luciano; Grano, Maria

2015-01-01

Bone has been considered a structure essential for mobility, calcium homeostasis, and hematopoietic function. Recent advances in bone biology have highlighted the importance of skeleton as an endocrine organ which regulates some metabolic pathways, in particular, insulin signaling and glucose tolerance. This review will point out the role of bone as an endocrine “gland” and, specifically, of bone-specific proteins, as the osteocalcin (Ocn), and proteins involved in bone remodeling, as osteoprotegerin, in the regulation of insulin function and glucose metabolism. PMID:25873957

Mice Lacking RIP3 Kinase are not Protected from Acute Radiation Syndrome.

PubMed

Castle, Katherine D; Daniel, Andrea R; Moding, Everett J; Luo, Lixia; Lee, Chang-Lung; Kirsch, David G

2018-06-01

Exposure to high doses of ionizing radiation can cause lethal injury to normal tissue, thus inducing acute radiation syndrome. Acute radiation syndrome is caused by depletion of bone marrow cells (hematopoietic syndrome) and irreparable damage to the epithelial cells in the gastrointestinal tract (gastrointestinal syndrome). Although radiation initiates apoptosis in the hematopoietic and gastrointestinal compartments within the first few hours after exposure, alternative mechanisms of cell death may contribute to injury in these radiosensitive tissues. In this study, we utilized mice lacking a critical regulator of necroptosis, receptor interacting protein 3 (RIP3) kinase, to characterize the role of RIP3 in normal tissue toxicity after irradiation. Our results suggest that RIP3-mediated signaling is not a critical driver of acute radiation syndrome.

The mammary cellular hierarchy and breast cancer.

PubMed

Oakes, Samantha R; Gallego-Ortega, David; Ormandy, Christopher J

2014-11-01

Advances in the study of hematopoietic cell maturation have paved the way to a deeper understanding the stem and progenitor cellular hierarchy in the mammary gland. The mammary epithelium, unlike the hematopoietic cellular hierarchy, sits in a complex niche where communication between epithelial cells and signals from the systemic hormonal milieu, as well as from extra-cellular matrix, influence cell fate decisions and contribute to tissue homeostasis. We review the discovery, definition and regulation of the mammary cellular hierarchy and we describe the development of the concepts that have guided our investigations. We outline recent advances in in vivo lineage tracing that is now challenging many of our assumptions regarding the behavior of mammary stem cells, and we show how understanding these cellular lineages has altered our view of breast cancer.

Effect of human cytomegalovirus infection on the expression of Hoxb2 and Hoxb4 genes in the developmental process of cord blood erythroid progenitors.

PubMed

Liu, Wen-Jun; Huang, Mei-Xian; Guo, Qu-Lian; Chen, Jun-Hong; Shi, Han

2011-01-01

The aim of the present study was to investigate the role of Hoxb2 and Hoxb4 gene expression induced by human cytomegalovirus (HCMV) and/or all-trans retinoic acid (ATRA) on the proliferation and committed differentiation process of human cord blood hematopoietic stem cells (HSCs) to colony-forming erythroid progenitor cells (CFU-Es) in vitro. Cord blood was collected from the fetal placenta umbilical vein in 12 cases and cultured using hematopoietic stem cell culture technique in vitro. The proliferation and differentiation of cord blood HSCs to CFU-Es were continuously disrupted with HCMV-AD169 and/or 6 x 10⁻⁸ mol/l of ATRA. Expression levels of the Hoxb2 and Hoxb4 genes in the blank, ATRA, HCMV-AD169 and ATRA + HCMV treatment groups of CFU-Es were detected on day 3, 7 and 10 of culture by fluorescent quantitative reverse transcriptase-polymerase chain reaction method. Hoxb2 and Hoxb4 gene expression in each group began on day 3, obviously increased on day 7 and reached a peak on day 10. The expression levels of the Hoxb2 and Hoxb4 genes in the HCMV group were obviously down-regulated compared with the level in the blank group. However, expression levels of the Hoxb2 and Hoxb4 genes were significantly up-regulated in the HCMV + ATRA group compared with the HCMV group (P<0.05). Abnormal expression of the Hoxb2 and Hoxb4 genes induced by HCMV may play important roles in abnormal hematopoietic damage. They were also correlated with the process of erythroid hematopoiesis. ATRA (6 x 10⁻⁸ mol/l) significantly up-regulated expression of the Hoxb2 and Hoxb4 genes in the normal erythroid progenitor cells and in those cells infected with HCMV as well.

Cutting the brakes on hematopoietic regeneration by blocking TGFβ to limit chemotherapy-induced myelosuppression

PubMed Central

Brenet, Fabienne; Scandura, Joseph M

2015-01-01

Hematopoietic stressors such as infection, bleeding, or toxic injury trigger a hematopoietic adaptation that sacrifices hematopoietic stem and progenitor cell (HSPC) quiescence to meet an urgent need for new blood cell production. Once the hematopoietic demands are adequately met, homeostasis must be restored. Transforming growth factor β (TGFβ) signaling is a central mediator mandating the return of HSPCs to quiescence after stress. Blockade of TGFβ signaling after hematopoietic stress delays the return of cycling HSPCs to quiescence and in so doing promotes hematopoietic stem cell (HSC) self-renewal and accelerates hematopoietic reconstitution. These findings open the door to new therapeutics that modulate the hematopoietic adaptation to stress. In this review, we will discuss the complex context-dependent activities of TGFβ in hematopoiesis and the potential benefits and limitations of using TGFβ pathway inhibitors to promote multilineage hematopoietic reconstitution after myelosuppressive chemotherapy. PMID:27308454

Fanconi anemia mesenchymal stromal cells-derived glycerophospholipids skew hematopoietic stem cell differentiation through Toll-like receptor signaling

PubMed Central

Amarachintha, Surya; Sertorio, Mathieu; Wilson, Andrew; Li, Xiaoli; Pang, Qishen

2015-01-01

Fanconi anemia (FA) patients develop bone marrow (BM) failure or leukemia. One standard care for these devastating complications is hematopoietic stem cell transplantation. We identified a group of mesenchymal stromal cells (MSCs)-derived metabolites, glycerophospholipids and their endogenous inhibitor, 5-(Tetradecyloxy)-2-furoic acid (TOFA), as regulators of donor hematopoietic stem and progenitor cells (HSPCs). We provided two pieces of evidence that TOFA could improve hematopoiesis-supporting function of FA MSCs: (1) limiting-dilution CAFC assay revealed that TOFA significantly increased cobblestone colonies in Fanca−/− or Fancd2−/− co-cultures compared to untreated co-cultures. (2) Competitive repopulating assay using output cells collected from co-cultures showed that TOFA greatly alleviated the abnormal expansion of the donor myeloid (CD45.2+Gr1+Mac1+) compartment in both peripheral blood and BM of recipient mice transplanted with cells from Fanca−/− or Fancd2−/− co-cultures. Further, mechanistic studies identified Tlr4 signaling as the responsible pathway mediating the effect of glycerophospholipids. Thus, targeting Glycerophospholipid biosynthesis in FA MSCs could be a therapeutic strategy to improve hematopoiesis and stem cell transplantation. PMID:26212365

Fanconi Anemia Mesenchymal Stromal Cells-Derived Glycerophospholipids Skew Hematopoietic Stem Cell Differentiation Through Toll-Like Receptor Signaling.

PubMed

Amarachintha, Surya; Sertorio, Mathieu; Wilson, Andrew; Li, Xiaoli; Pang, Qishen

2015-11-01

Fanconi anemia (FA) patients develop bone marrow (BM) failure or leukemia. One standard care for these devastating complications is hematopoietic stem cell transplantation. We identified a group of mesenchymal stromal cells (MSCs)-derived metabolites, glycerophospholipids, and their endogenous inhibitor, 5-(tetradecyloxy)-2-furoic acid (TOFA), as regulators of donor hematopoietic stem and progenitor cells. We provided two pieces of evidence that TOFA could improve hematopoiesis-supporting function of FA MSCs: (a) limiting-dilution cobblestone area-forming cell assay revealed that TOFA significantly increased cobblestone colonies in Fanca-/- or Fancd2-/- cocultures compared to untreated cocultures. (b) Competitive repopulating assay using output cells collected from cocultures showed that TOFA greatly alleviated the abnormal expansion of the donor myeloid (CD45.2+Gr1+Mac1+) compartment in both peripheral blood and BM of recipient mice transplanted with cells from Fanca-/- or Fancd2-/- cocultures. Furthermore, mechanistic studies identified Tlr4 signaling as the responsible pathway mediating the effect of glycerophospholipids. Thus, targeting glycerophospholipid biosynthesis in FA MSCs could be a therapeutic strategy to improve hematopoiesis and stem cell transplantation. © 2015 AlphaMed Press.

The Effects of Hematopoietic Growth Factors on Neurite Outgrowth

PubMed Central

Su, Ye; Cui, Lili; Piao, Chunshu; Li, Bin; Zhao, Li-Ru

2013-01-01

Stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) are initially discovered as the essential hematopoietic growth factors regulating bone marrow stem cell proliferation and differentiation, and SCF in combination with G-CSF (SCF+G-CSF) has synergistic effects on bone marrow stem cell mobilization. In this study we have determined the effect of SCF and G-CSF on neurite outgrowth in rat cortical neurons. Using molecular and cellular biology and live cell imaging approaches, we have revealed that receptors for SCF and G-CSF are expressed on the growth core of cortical neurons, and that SCF+G-CSF synergistically enhances neurite extension through PI3K/AKT and NFκB signaling pathways. Moreover, SCF+G-CSF induces much greater NFκB activation, NFκB transcriptional binding and brain-derived neurotrophic factor (BDNF) production than SCF or G-CSF alone. In addition, we have also observed that BDNF, the target gene of NFκB, is required for SCF+G-CSF-induced neurite outgrowth. These data suggest that SCF+G-CSF has synergistic effects to promote neurite growth. This study provides new insights into the contribution of hematopoietic growth factors in neuronal plasticity. PMID:24116056

Runx1 and Cbfβ regulate the development of Flt3+ dendritic cell progenitors and restrict myeloproliferative disorder

PubMed Central

Satpathy, Ansuman T.; Briseño, Carlos G.; Cai, Xiongwei; Michael, Drew G.; Chou, Chun; Hsiung, Sunnie; Bhattacharya, Deepta; Speck, Nancy A.

2014-01-01

Runx1 and Cbfβ are critical for the establishment of definitive hematopoiesis and are implicated in leukemic transformation. Despite the absolute requirements for these factors in the development of hematopoietic stem cells and lymphocytes, their roles in the development of bone marrow progenitor subsets have not been defined. Here, we demonstrate that Cbfβ is essential for the development of Flt3+ macrophage-dendritic cell (DC) progenitors in the bone marrow and all DC subsets in the periphery. Besides the loss of DC progenitors, pan-hematopoietic Cbfb-deficient mice also lack CD105+ erythroid progenitors, leading to severe anemia at 3 to 4 months of age. Instead, Cbfb deficiency results in aberrant progenitor differentiation toward granulocyte-macrophage progenitors (GMPs), resulting in a myeloproliferative phenotype with accumulation of GMPs in the periphery and cellular infiltration of the liver. Expression of the transcription factor Irf8 is severely reduced in Cbfb-deficient progenitors, and overexpression of Irf8 restors DC differentiation. These results demonstrate that Runx proteins and Cbfβ restrict granulocyte lineage commitment to facilitate multilineage hematopoietic differentiation and thus identify their novel tumor suppressor function in myeloid leukemia. PMID:24677539

Drosophila homolog of the human S6 ribosomal protein is required for tumor suppression in the hematopoietic system.

PubMed Central

Watson, K L; Konrad, K D; Woods, D F; Bryant, P J

1992-01-01

The tumor suppressor gene lethal(1)aberrant immune response 8 (air8) of Drosophila melanogaster encodes a homolog of the human S6 ribosomal protein. P element insertions that prevent expression of this gene cause overgrowth of the lymph glands (the hematopoietic organs), abnormal blood cell differentiation, and melanotic tumor formation. They also cause delayed development, inhibit growth of most of the larval organs, and lead to larval lethality. Mitotic recombination experiments indicate that the normal S6 gene is required for clone survival in the germ line and imaginal discs. The S6 gene produces a 1.1-kilobase transcript that is abundant throughout development in wild-type animals and in revertants derived from the insertional mutants but is barely detectable in the mutant larvae. cDNAs corresponding to this transcript show a 248-amino acid open reading frame with 75.4% identity and 94.8% similarity to both human and rat S6 ribosomal protein sequences. The results reveal a regulatory function of this ribosomal protein in the hematopoietic system of Drosophila that may be related to its developmentally regulated phosphorylation. Images PMID:1454811

Quantitative analysis by next generation sequencing of hematopoietic stem and progenitor cells (LSK) and of splenic B cells transcriptomes from wild-type and Usp3-knockout mice.

PubMed

Lancini, Cesare; Gargiulo, Gaetano; van den Berk, Paul C M; Citterio, Elisabetta

2016-03-01

The data described here provide genome-wide expression profiles of murine primitive hematopoietic stem and progenitor cells (LSK) and of B cell populations, obtained by high throughput sequencing. Cells are derived from wild-type mice and from mice deficient for the ubiquitin-specific protease 3 (USP3; Usp3Δ/Δ). Modification of histone proteins by ubiquitin plays a crucial role in the cellular response to DNA damage (DDR) (Jackson and Durocher, 2013) [1]. USP3 is a histone H2A deubiquitinating enzyme (DUB) that regulates ubiquitin-dependent DDR in response to DNA double-strand breaks (Nicassio et al., 2007; Doil et al., 2008) [2], [3]. Deletion of USP3 in mice increases the incidence of spontaneous tumors and affects hematopoiesis [4]. In particular, Usp3-knockout mice show progressive loss of B and T cells and decreased functional potential of hematopoietic stem cells (HSCs) during aging. USP3-deficient cells, including HSCs, display enhanced histone ubiquitination, accumulate spontaneous DNA damage and are hypersensitive to ionizing radiation (Lancini et al., 2014) [4]. To address whether USP3 loss leads to deregulation of specific molecular pathways relevant to HSC homeostasis and/or B cell development, we have employed the RNA-sequencing technology and investigated transcriptional differences between wild-type and Usp3Δ/Δ LSK, naïve B cells or in vitro activated B cells. The data relate to the research article "Tight regulation of ubiquitin-mediated DNA damage response by USP3 preserves the functional integrity of hematopoietic stem cells" (Lancini et al., 2014) [4]. The RNA-sequencing and analysis data sets have been deposited in NCBI׳s Gene Expression Omnibus (Edgar et al., 2002) [5] and are accessible through GEO Series accession number GSE58495 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE58495). With this article, we present validation of the RNA-seq data set through quantitative real-time PCR and comparative analysis.

Molecular Analysis of Neutrophil Differentiation from Human Induced Pluripotent Stem Cells Delineates the Kinetics of Key Regulators of Hematopoiesis.

PubMed

Sweeney, Colin L; Teng, Ruifeng; Wang, Hongmei; Merling, Randall K; Lee, Janet; Choi, Uimook; Koontz, Sherry; Wright, Daniel G; Malech, Harry L

2016-06-01

In vitro generation of mature neutrophils from human induced pluripotent stem cells (iPSCs) requires hematopoietic progenitor development followed by myeloid differentiation. The purpose of our studies was to extensively characterize this process, focusing on the critical window of development between hemogenic endothelium, hematopoietic stem/progenitor cells (HSPCs), and myeloid commitment, to identify associated regulators and markers that might enable the stem cell field to improve the efficiency and efficacy of iPSC hematopoiesis. We utilized a four-stage differentiation protocol involving: embryoid body (EB) formation (stage-1); EB culture with hematopoietic cytokines (stage-2); HSPC expansion (stage-3); and neutrophil maturation (stage-4). CD34(+) CD45(-) putative hemogenic endothelial cells were observed in stage-3 cultures, and expressed VEGFR-2/Flk-1/KDR and VE-cadherin endothelial markers, GATA-2, AML1/RUNX1, and SCL/TAL1 transcription factors, and endothelial/HSPC-associated microRNAs miR-24, miR-125a-3p, miR-126/126*, and miR-155. Upon further culture, CD34(+) CD45(-) cells generated CD34(+) CD45(+) HSPCs that produced hematopoietic CFUs. Mid-stage-3 CD34(+) CD45(+) HSPCs exhibited increased expression of GATA-2, AML1/RUNX1, SCL/TAL1, C/EBPα, and PU.1 transcription factors, but exhibited decreased expression of HSPC-associated microRNAs, and failed to engraft in immune-deficient mice. Mid-stage-3 CD34(-) CD45(+) cells maintained PU.1 expression and exhibited increased expression of hematopoiesis-associated miR-142-3p/5p and a trend towards increased miR-223 expression, indicating myeloid commitment. By late Stage-4, increased CD15, CD16b, and C/EBPɛ expression were observed, with 25%-65% of cells exhibiting morphology and functions of mature neutrophils. These studies demonstrate that hematopoiesis and neutrophil differentiation from human iPSCs recapitulates many features of embryonic hematopoiesis and neutrophil production in marrow, but reveals unexpected molecular signatures that may serve as a guide for enhancing iPSC hematopoiesis. Stem Cells 2016;34:1513-1526. © 2016 AlphaMed Press.

Molecular analysis of neutrophil differentiation from human iPSCs delineates the kinetics of key regulators of hematopoiesis

PubMed Central

Sweeney, Colin L.; Teng, Ruifeng; Wang, Hongmei; Merling, Randall K.; Lee, Janet; Choi, Uimook; Koontz, Sherry; Wright, Daniel G.; Malech, Harry L.

2016-01-01

In vitro generation of mature neutrophils from human induced pluripotent stem cells (iPSCs) requires hematopoietic progenitor development followed by myeloid differentiation. The purpose of our studies was to extensively characterize this process, focusing on the critical window of development between hemogenic endothelium, hematopoietic stem/progenitor cells (HSPCs), and myeloid commitment, to identify associated regulators and markers that might enable the stem cell field to improve the efficiency and efficacy of iPSC hematopoiesis. We utilized a 4-stage differentiation protocol involving: embryoid body (EB) formation (Stage-1); EB culture with hematopoietic cytokines (Stage-2); HSPC expansion (Stage-3); and neutrophil maturation (Stage-4). CD34+CD45− putative hemogenic endothelial cells were observed in Stage-3 cultures, and expressed VEGFR-2/Flk-1/KDR and VE-cadherin endothelial markers, GATA-2, AML1/RUNX1, and SCL/TAL1 transcription factors, and endothelial/HSPC-associated microRNAs miR-24, miR-125a-3p, miR-126/126*, and miR-155. Upon further culture, CD34+CD45− cells generated CD34+CD45+ HSPCs that produced hematopoietic CFUs. Mid-Stage-3 CD34+CD45+ HSPCs exhibited increased expression of GATA-2, AML1/RUNX1, SCL/TAL1, C/EBPα, and PU.1 transcription factors, but exhibited decreased expression of HSPC-associated microRNAs, and failed to engraft in immune-deficient mice. Mid-stage-3 CD34−CD45+ cells maintained PU.1 expression and exhibited increased expression of hematopoiesis-associated miR-142-3p/5p and a trend towards increased miR-223 expression, indicating myeloid commitment. By late Stage-4, increased CD15, CD16b, and C/EBPε expression were observed, with 25–65% of cells exhibiting morphology and functions of mature neutrophils. These studies demonstrate that hematopoiesis and neutrophil differentiation from human iPSCs recapitulates many features of embryonic hematopoiesis and neutrophil production in marrow, but reveals unexpected molecular signatures that may serve as a guide for enhancing iPSC hematopoiesis. PMID:26866427

Dynamic Cross Talk between S1P and CXCL12 Regulates Hematopoietic Stem Cells Migration, Development and Bone Remodeling

PubMed Central

Golan, Karin; Kollet, Orit; Lapidot, Tsvee

2013-01-01

Hematopoietic stem cells (HSCs) are mostly retained in a quiescent non-motile mode in their bone marrow (BM) niches, shifting to a migratory cycling and differentiating state to replenish the blood with mature leukocytes on demand. The balance between the major chemo-attractants CXCL12, predominantly in the BM, and S1P, mainly in the blood, dynamically regulates HSC recruitment to the circulation versus their retention in the BM. During alarm situations, stress-signals induce a decrease in CXCL12 levels in the BM, while S1P levels are rapidly and transiently increased in the circulation, thus favoring mobilization of stem cells as part of host defense and repair mechanisms. Myeloid cytokines, including G-CSF, up-regulate S1P signaling in the BM via the PI3K pathway. Induced CXCL12 secretion from stromal cells via reactive oxygen species (ROS) generation and increased S1P1 expression and ROS signaling in HSCs, all facilitate mobilization. Bone turnover is also modulated by both CXCL12 and S1P, regulating the dynamic BM stromal microenvironment, osteoclasts and stem cell niches which all functionally express CXCL12 and S1P receptors. Overall, CXCL12 and S1P levels in the BM and circulation are synchronized to mutually control HSC motility, leukocyte production and osteoclast/osteoblast bone turnover during homeostasis and stress situations. PMID:24276423

Inactivation of a Single Copy of Crebbp Selectively Alters Pre-mRNA Processing in Mouse Hematopoietic Stem Cells

PubMed Central

Lemieux, Madeleine E.; Cheng, Ziming; Zhou, Qing; White, Ruth; Cornell, John; Kung, Andrew L.; Rebel, Vivienne I.

2011-01-01

Global expression analysis of fetal liver hematopoietic stem cells (FL HSCs) revealed the presence of unspliced pre-mRNA for a number of genes in normal FL HSCs. In a subset of these genes, Crebbp+/− FL HSCs had less unprocessed pre-mRNA without a corresponding reduction in total mRNA levels. Among the genes thus identified were the key regulators of HSC function Itga4, Msi2 and Tcf4. A similar but much weaker effect was apparent in Ep300+/− FL HSCs, indicating that, in this context as in others, the two paralogs are not interchangeable. As a group, the down-regulated intronic probe sets could discriminate adult HSCs from more mature cell types, suggesting that the underlying mechanism is regulated with differentiation stage and is active in both fetal and adult hematopoiesis. Consistent with increased myelopoiesis in Crebbp hemizygous mice, targeted reduction of CREBBP abundance by shRNA in the multipotent EML cell line triggered spontaneous myeloid differentiation in the absence of the normally required inductive signals. In addition, differences in protein levels between phenotypically distinct EML subpopulations were better predicted by taking into account not only the total mRNA signal but also the amount of unspliced message present. CREBBP thus appears to selectively influence the timing and degree of pre-mRNA processing of genes essential for HSC regulation and thereby has the potential to alter subsequent cell fate decisions in HSCs. PMID:21901164

p38 MAPK inhibition suppresses the TLR-hypersensitive phenotype in FANCC- and FANCA-deficient mononuclear phagocytes

PubMed Central

Anur, Praveen; Yates, Jane; Garbati, Michael R.; Vanderwerf, Scott; Keeble, Winifred; Rathbun, Keaney; Hays, Laura E.; Tyner, Jeffrey W.; Svahn, Johanna; Cappelli, Enrico; Dufour, Carlo

2012-01-01

Fanconi anemia, complementation group C (FANCC)–deficient hematopoietic stem and progenitor cells are hypersensitive to a variety of inhibitory cytokines, one of which, TNFα, can induce BM failure and clonal evolution in Fancc-deficient mice. FANCC-deficient macrophages are also hypersensitive to TLR activation and produce TNFα in an unrestrained fashion. Reasoning that suppression of inhibitory cytokine production might enhance hematopoiesis, we screened small molecules using TLR agonist–stimulated FANCC- and Fanconi anemia, complementation group A (FANCA)–deficient macrophages containing an NF-κB/AP-1–responsive reporter gene (SEAP). Of the 75 small molecules screened, the p38 MAPK inhibitor BIRB 796 and dasatinib potently suppressed TLR8-dependent expression of the reporter gene. Fanconi anemia (FA) macrophages were hypersensitive to the TLR7/8 activator R848, overproducing SEAP and TNFα in response to all doses of the agonist. Low doses (50nM) of both agents inhibited p38 MAPK–dependent activation of MAPKAPK2 (MK2) and suppressed MK2-dependent TNFα production without substantially influencing TNFα gene transcription. Overproduction of TNFα by primary FA cells was likewise suppressed by these agents and involved inhibition of MK2 activation. Because MK2 is also known to influence production and/or sensitivity to 2 other suppressive factors (MIP-1α and IFNγ) to which FA hematopoietic progenitor cells are uniquely vulnerable, targeting of p38 MAPK in FA hematopoietic cells is a rational objective for preclinical evaluation. PMID:22234699

p38 MAPK inhibition suppresses the TLR-hypersensitive phenotype in FANCC- and FANCA-deficient mononuclear phagocytes.

PubMed

Anur, Praveen; Yates, Jane; Garbati, Michael R; Vanderwerf, Scott; Keeble, Winifred; Rathbun, Keaney; Hays, Laura E; Tyner, Jeffrey W; Svahn, Johanna; Cappelli, Enrico; Dufour, Carlo; Bagby, Grover C

2012-03-01

Fanconi anemia, complementation group C (FANCC)-deficient hematopoietic stem and progenitor cells are hypersensitive to a variety of inhibitory cytokines, one of which, TNFα, can induce BM failure and clonal evolution in Fancc-deficient mice. FANCC-deficient macrophages are also hypersensitive to TLR activation and produce TNFα in an unrestrained fashion. Reasoning that suppression of inhibitory cytokine production might enhance hematopoiesis, we screened small molecules using TLR agonist-stimulated FANCC- and Fanconi anemia, complementation group A (FANCA)-deficient macrophages containing an NF-κB/AP-1-responsive reporter gene (SEAP). Of the 75 small molecules screened, the p38 MAPK inhibitor BIRB 796 and dasatinib potently suppressed TLR8-dependent expression of the reporter gene. Fanconi anemia (FA) macrophages were hypersensitive to the TLR7/8 activator R848, overproducing SEAP and TNFα in response to all doses of the agonist. Low doses (50nM) of both agents inhibited p38 MAPK-dependent activation of MAPKAPK2 (MK2) and suppressed MK2-dependent TNFα production without substantially influencing TNFα gene transcription. Overproduction of TNFα by primary FA cells was likewise suppressed by these agents and involved inhibition of MK2 activation. Because MK2 is also known to influence production and/or sensitivity to 2 other suppressive factors (MIP-1α and IFNγ) to which FA hematopoietic progenitor cells are uniquely vulnerable, targeting of p38 MAPK in FA hematopoietic cells is a rational objective for preclinical evaluation.

Clonal evolution and clinical significance of copy number neutral loss of heterozygosity of chromosome arm 6p in acquired aplastic anemia.

PubMed

Betensky, Marisol; Babushok, Daria; Roth, Jacquelyn J; Mason, Philip J; Biegel, Jaclyn A; Busse, Tracy M; Li, Yimei; Lind, Curt; Papazoglou, Anna; Monos, Dimitri; Podsakoff, Gregory; Bessler, Monica; Olson, Timothy S

2016-01-01

Acquired aplastic anemia (aAA) results from the T cell-mediated autoimmune destruction of hematopoietic stem cells. Factors predicting response to immune suppression therapy (IST) or development of myelodysplastic syndrome (MDS) are beginning to be elucidated. Our recent data suggest most patients with aAA treated with IST develop clonal somatic genetic alterations in hematopoietic cells. One frequent acquired abnormality is copy-number neutral loss of heterozygosity on chromosome 6p (6p CN-LOH) involving the human leukocyte antigen (HLA) locus. We hypothesized that because 6p CN-LOH clones may arise from selective pressure to escape immune surveillance through deletion of HLA alleles, the development of 6p CN-LOH may affect response to IST. We used single nucleotide polymorphism array genotyping and targeted next-generation sequencing of HLA alleles to assess frequency of 6p CN-LOH, identity of HLA alleles lost through 6p CN-LOH, and impact of 6p CN-LOH on response to IST. 6p CN-LOH clones were present in 11.3% of patients, remained stable over time, and were not associated with development of MDS-defining cytogenetic abnormalities. Notably, no patient with 6p CN-LOH treated with IST achieved a complete response. In summary, clonal 6p CN-LOH in aAA defines a unique subgroup of patients that may provide insights into hematopoietic clonal evolution. Copyright © 2016 Elsevier Inc. All rights reserved.

Clonal Evolution and Clinical Significance of Copy Number Neutral Loss of Heterozygosity of Chromosome Arm 6p in Acquired Aplastic Anemia

PubMed Central

Betensky, Marisol; Babushok, Daria; Roth, Jacquelyn J.; Mason, Philip J; Biegel, Jaclyn A.; Busse, Tracy M; Li, Yimei; Lind, Curt; Papazoglou, Anna; Monos, Dimitri; Podsakoff, Gregory; Bessler, Monica; Olson, Timothy S.

2015-01-01

Acquired aplastic anemia (aAA) results from the T cell-mediated autoimmune destruction of hematopoietic stem cells. Factors predicting response to immune suppression therapy (IST) or development of myelodysplastic syndrome (MDS) are beginning to be elucidated. Our recent data suggest most patients with aAA treated with IST develop clonal somatic genetic alterations in hematopoietic cells. One frequent acquired abnormality is copy-number neutral loss of heterozygosity on chromosome 6p (6p CN-LOH) involving the human leukocyte antigen (HLA) locus. We hypothesized that because 6p CN-LOH clones may arise from selective pressure to escape immune surveillance through deletion of HLA alleles, the development of 6p CN-LOH may affect response to IST. We used single nucleotide polymorphism array genotyping and targeted next-generation sequencing of HLA alleles to assess frequency of 6p CN-LOH, identity of HLA alleles lost through 6p CN-LOH, and impact of 6p CN-LOH on response to IST. 6p CN-LOH clones were present in 11.3% of patients, remained stable over time, and were not associated with development of MDS-defining cytogenetic abnormalities. Notably, no patient with 6p CN-LOH treated with IST achieved a complete response. In summary, clonal 6p CN-LOH in aAA defines a unique subgroup of patients that may provide insights into hematopoietic clonal evolution. PMID:26702937

Hematopoietic Stem Cell Transplantation—50 Years of Evolution and Future Perspectives

PubMed Central

Henig, Israel; Zuckerman, Tsila

2014-01-01

Hematopoietic stem cell transplantation is a highly specialized and unique medical procedure. Autologous transplantation allows the administration of high-dose chemotherapy without prolonged bone marrow aplasia. In allogeneic transplantation, donor-derived stem cells provide alloimmunity that enables a graft-versus-tumor effect to eradicate residual disease and prevent relapse. The first allogeneic transplantation was performed by E. Donnall Thomas in 1957. Since then the field has evolved and expanded worldwide. New indications beside acute leukemia and aplastic anemia have been constantly explored and now include congenital disorders of the hematopoietic system, metabolic disorders, and autoimmune disease. The use of matched unrelated donors, umbilical cord blood units, and partially matched related donors has dramatically extended the availability of allogeneic transplantation. Transplant-related mortality has decreased due to improved supportive care, including better strategies to prevent severe infections and with the incorporation of reduced-intensity conditioning protocols that lowered the toxicity and allowed for transplantation in older patients. However, disease relapse and graft-versus-host disease remain the two major causes of mortality with unsatisfactory progress. Intense research aiming to improve adoptive immunotherapy and increase graft-versus-leukemia response while decreasing graft-versus-host response might bring the next breakthrough in allogeneic transplantation. Strategies of graft manipulation, tumor-associated antigen vaccinations, monoclonal antibodies, and adoptive cellular immunotherapy have already proved clinically efficient. In the following years, allogeneic transplantation is likely to become more complex, more individualized, and more efficient. PMID:25386344

Transforming growth factor-beta1 transcriptionally activates CD34 and prevents induced differentiation of TF-1 cells in the absence of any cell-cycle effects.

PubMed

Marone, M; Scambia, G; Bonanno, G; Rutella, S; de Ritis, D; Guidi, F; Leone, G; Pierelli, L

2002-01-01

A number of cytokines modulate self-renewal and differentiation of hematopoietic elements. Among these is transforming growth factor beta1 (TGF-beta1), which regulates cell cycle and differentiation of hematopoietic cells, but has pleiotropic activities depending on the state of responsiveness of the target cells. It has been previously shown by us and other authors that TGF-beta1 maintains human CD34(+) hematopoietic progenitors in an undifferentiated state, independently of any cell cycle effects, and that depletion of TGF-beta1 triggers differentiation accompanied by a decrease in CD34 antigen expression. In the present work, we show that exogenous TGF-beta1 upregulates the human CD34 antigen in the CD34(+) cell lines TF-1 and KG-1a, but not in the more differentiated CD34(-) cell lines HL-60 and K-562. We further studied this effect in the pluripotent erythroleukemia cell line TF-1. Here, TGF-beta1 did not effect cell growth, but induced transcriptional activation of full-length CD34 and prevented differentiation induced by differentiating agents. This effect was associated with nuclear translocation of Smad-2, activation of TAK-1, and with a dramatic decrease in p38 phosphorylation. In other systems TGF-beta1 has been shown to activate a TGF-beta-activated kinase 1 (TAK1), which in turn, activates p38. The specific inhibitor of p38 phosphorylation, SB202190, also increased CD34 RNA expression, indicating the existence of a link between p-38 inhibition by TGF-beta1 and CD34 overexpression. Our data demonstrate that TGF-beta1 transcriptionally activates CD34 and prevents differentiation of TF-1 cells by acting independently through the Smad, TAK1 and p38 pathways, and thus provide important clues for the understanding of hematopoietic development and a potential tool to modify response of hematopoietic cells to mitogens or differentiating agents.

Noncanonical Wnt5a-Ca(2+) -NFAT signaling axis in pesticide induced bone marrow aplasia mouse model: A study to explore the novel mechanism of pesticide toxicity.

PubMed

Chattopadhyay, Sukalpa; Chatterjee, Ritam; Law, Sujata

2016-10-01

According to case-control studies, long-term pesticide exposure can cause bone marrow aplasia like hematopoietic degenerative disease leading to impaired hematopoiesis and increased risk of aplastic anemia in human subjects. However, the exact mechanism of pesticide mediated hematotoxicity still remains elusive. In this study, we investigated the role of noncanonical Wnt signaling pathway, a crucial regulator of adult hematopoiesis, in pesticide induced bone marrow aplasia mouse model. Aplasia mouse model was developed following inhalation and dermal exposure of 5% aqueous mixture of common agriculturally used pesticides for 6 h/day for 5 days a week up to 90 days. After that, blood hemogram, marrow smear, cellularity, scanning electron microscopy, extramedullary hematopoiesis and flowcytometric expression analysis of noncanonical Wnt signaling components, such as Wnt 5a, fzd5, NFAT, IFN-γ, intracellular Ca(2+) level were evaluated in the bone marrow hematopoietic stem/progenitor compartment of the control and pesticide induced aplasia groups of animals. Results showed that pesticide exposed mice were anemic with peripheral blood pancytopenia, hypocellular degenerative marrow, and extramedullary hematopoiesis in the spleen. Upon pesticide exposure, Wnt 5a expression was severely downregulated with a decline in intracellular Ca(2+) level. Moreover, downstream of Wnt5a, we observed sharp downregulation of NFATc2 transcription factor expression, the major target of pesticide toxicity and its target molecule IFN-γ. Taken together, our result suggests that deregulation of Wnt5a-Ca(2+) -NFAT signaling axis in the hematopoietic stem/progenitor compartment plays a crucial role behind the pathogenesis of pesticide mediated bone marrow aplasia by limiting primitive hematopoietic stem cells' ability to maintain hematopoietic homeostasis and reconstitution mechanism in vivo during xenobiotic stress leading to ineffective hematopoiesis and evolution of bone marrow aplasia. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1163-1175, 2016. © 2015 Wiley Periodicals, Inc.

High Levels of Morbidity and Mortality Among Pediatric Hematopoietic Cell Transplant Recipients With Severe Sepsis: Insights From the Sepsis PRevalence, OUtcomes, and Therapies International Point Prevalence Study.

PubMed

Lindell, Robert B; Gertz, Shira J; Rowan, Courtney M; McArthur, Jennifer; Beske, Florian; Plunkett, Adrian; Weiss, Scott L; Thomas, Neal J; Nadkarni, Vinay M; Fitzgerald, Julie C

2017-12-01

Pediatric severe sepsis is a major cause of morbidity and mortality worldwide, and hematopoietic cell transplant patients represent a high-risk population. We assessed the epidemiology of severe sepsis in hematopoietic cell transplant patients, describing patient outcomes compared with children with no history of hematopoietic cell transplant. Secondary analysis of the Sepsis PRevalence, OUtcomes, and Therapies point prevalence study, comparing demographics, sepsis etiology, illness severity, organ dysfunction, and sepsis-related treatments in patients with and without hematopoietic cell transplant. The primary outcome was hospital mortality. Multivariable logistic regression models were used to determine adjusted differences in mortality. International; 128 PICUs in 26 countries. Pediatric patients with severe sepsis prospectively identified over a 1-year period. None. In patients with severe sepsis, 37/567 (6.5%) had a history of hematopoietic cell transplant. Compared with patients without hematopoietic cell transplant, hematopoietic cell transplant patients had significantly higher hospital mortality (68% vs 23%; p < 0.001). Hematopoietic cell transplant patients were more likely to have hospital acquired sepsis and had more preexisting renal and hepatic dysfunction than non-hematopoietic cell transplant patients with severe sepsis. History of hematopoietic cell transplant, renal replacement therapy, admission from inpatient floor, and number of organ dysfunctions at severe sepsis recognition were independently associated with hospital mortality in multivariable analysis; hematopoietic cell transplant conferred the highest odds of mortality (odds ratio, 4.00; 95% CI, 1.78-8.98). In secondary analysis of hematopoietic cell transplant patients compared with other immunocompromised patients with severe sepsis, history of hematopoietic cell transplant remained independently associated with hospital mortality (odds ratio, 3.03; 95% CI, 1.11-8.27). In an international study of pediatric severe sepsis, history of hematopoietic cell transplant is associated with a four-fold increased odds of hospital mortality after adjustment for potential measured confounders. Hematopoietic cell transplant patients more often originated from within the hospital compared to children with severe sepsis without hematopoietic cell transplant, possibly providing an earlier opportunity for sepsis recognition and intervention in this high-risk population.

Thrombopoietin: biology and clinical potentials.

PubMed

Miyazaki, H; Kato, T

1999-12-01

Thrombopoietin (TPO) is the principal physiologic regulator of platelet production. In vitro, TPO induces the growth of colony-forming units-megakaryocyte (CFU-MK) and the generation of mature polyploid megakaryocytes, which subsequently form extended cytoplasmic processes, termed proplatelets. On more differentiated CFU-MK, but not on megakaryocytes, TPO is critical for enhancing proplatelet formation. TPO has multilineage effects in hematopoiesis, not only stimulating megakaryocytopoiesis but also acting in synergy with other cytokines to enhance proliferation and survival of committed erythroid progenitors and primitive hematopoietic stem cells. Surface c-MPL, the receptor for TPO, defines a phenotype of hematopoietic stem cells with long-term repopulating ability. Treatment with various cytokine combinations, including TPO, results in an extensive ex vivo expansion of hematopoietic stem cells and blood cell precursors. In normal animals, pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) or glycosylated TPO increases the number of bone marrow megakaryocytes and their progenitors and greatly enhance the production of morphologically and functionally normal platelets. In contrast, they have only minimal effects on peripheral white blood cell and red blood cell counts. PEG-rHuMGDF used alone markedly expands circulating levels of multiple types of hematopoietic progenitors, and its effect is enhanced in combination with granulocyte colony-stimulating factor (G-CSF). Although PEG-rHuMGDF augments platelet aggregation induced by agonists in vitro, it has no influence in an animal model of thrombus formation. PEG-rHuMGDF or glycosylated TPO has a profound effect in a variety of animal models of thrombocytopenia, including myelosuppressive therapy. PEG-rHuMGDF treatment accelerates multilineage hematopoietic recovery, effectively improving thrombocytopenia, and, in most models, neutropenia and anemia. The concurrent administration of PEG-rHuMGDF and G-CSF does not interfere with the in vivo activity of cytokines but rather has synergistic effects. To further accelerate hematopoietic recovery, PEG-rHuMGDF administration should start at the earliest time following myelosuppressive treatment; this time sensitivity may result from the presence of a greater number of residual hematopoietic progenitors in the bone marrow soon after treatment. Moreover, if a relatively large dose of PEG-rHuMGDF is administered, a single intravenous injection is fully effective in improving impaired hematopoiesis. This effectiveness appears to be related to the persistence of PEG-rHuMGDF in the circulation. The safety and efficacy of two forms of the recombinant hormone, PEG-rHuMDGF and glycosylated human full-length TPO produced in mammalian cells, are currently under clinical investigation.

Proteomic Cornerstones of Hematopoietic Stem Cell Differentiation: Distinct Signatures of Multipotent Progenitors and Myeloid Committed Cells*

PubMed Central

Klimmeck, Daniel; Hansson, Jenny; Raffel, Simon; Vakhrushev, Sergey Y.; Trumpp, Andreas; Krijgsveld, Jeroen

2012-01-01

Regenerative tissues such as the skin epidermis, the intestinal mucosa or the hematopoietic system are organized in a hierarchical manner with stem cells building the top of this hierarchy. Somatic stem cells harbor the highest self-renewal activity and generate a series of multipotent progenitors which differentiate into lineage committed progenitors and subsequently mature cells. In this report, we applied an in-depth quantitative proteomic approach to analyze and compare the full proteomes of ex vivo isolated and FACS-sorted populations highly enriched for either multipotent hematopoietic stem/progenitor cells (HSPCs, LinnegSca-1+c-Kit+) or myeloid committed precursors (LinnegSca-1−c-Kit+). By employing stable isotope dimethyl labeling and high-resolution mass spectrometry, more than 5000 proteins were quantified. From biological triplicate experiments subjected to rigorous statistical evaluation, 893 proteins were found differentially expressed between multipotent and myeloid committed cells. The differential protein content in these cell populations points to a distinct structural organization of the cytoskeleton including remodeling activity. In addition, we found a marked difference in the expression of metabolic enzymes, including a clear shift of specific protein isoforms of the glycolytic pathway. Proteins involved in translation showed a collective higher expression in myeloid progenitors, indicating an increased translational activity. Strikingly, the data uncover a unique signature related to immune defense mechanisms, centering on the RIG-I and type-1 interferon response systems, which are installed in multipotent progenitors but not evident in myeloid committed cells. This suggests that specific, and so far unrecognized, mechanisms protect these immature cells before they mature. In conclusion, this study indicates that the transition of hematopoietic stem/progenitors toward myeloid commitment is accompanied by a profound change in processing of cellular resources, adding novel insights into the molecular mechanisms at the interface between multipotency and lineage commitment. PMID:22454540

Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells.

PubMed

Codispoti, Bruna; Rinaldo, Nicola; Chiarella, Emanuela; Lupia, Michela; Spoleti, Cristina Barbara; Marafioti, Maria Grazia; Aloisio, Annamaria; Scicchitano, Stefania; Giordano, Marco; Nappo, Giovanna; Lucchino, Valeria; Moore, Malcolm A S; Zhou, Pengbo; Mesuraca, Maria; Bond, Heather Mandy; Morrone, Giovanni

2017-07-04

Transplantation of hematopoietic stem cells (HSCs) is a well-established therapeutic approach for numerous disorders. HSCs are typically derived from bone marrow or peripheral blood after cytokine-induced mobilization. Umbilical cord blood (CB) represents an appealing alternative HSC source, but the small amounts of the individual CB units have limited its applications. The availability of strategies for safe ex vivo expansion of CB-derived HSCs (CB-HSCs) may allow to extend the use of these cells in adult patients and to avoid the risk of insufficient engraftment or delayed hematopoietic recovery.Here we describe a system for the ex vivo expansion of CB-HSCs based on their transient exposure to a recombinant TAT-BMI-1 chimeric protein. BMI-1 belongs to the Polycomb family of epigenetic modifiers and is recognized as a central regulator of HSC self-renewal. Recombinant TAT-BMI-1 produced in bacteria was able to enter the target cells via the HIV TAT-derived protein transduction peptide covalently attached to BMI-1, and conserved its biological activity. Treatment of CB-CD34+ cells for 3 days with repeated addition of 10 nM purified TAT-BMI-1 significantly enhanced total cell expansion as well as that of primitive hematopoietic progenitors in culture. Importantly, TAT-BMI-1-treated CB-CD34+ cells displayed a consistently higher rate of multi-lineage long-term repopulating activity in primary and secondary xenotransplants in immunocompromised mice. Thus, recombinant TAT-BMI-1 may represent a novel, effective reagent for ex vivo expansion of CB-HSC for therapeutic purposes.

Hematopoietic Colony Formation from Human Growth Factor-Dependent TF1 Cells and Human Cord Blood Myeloid Progenitor Cells Depends on SHP2 Phosphatase Function

PubMed Central

Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E.; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun

2013-01-01

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity. PMID:23082805

Hematopoietic colony formation from human growth factor-dependent TF1 cells and human cord blood myeloid progenitor cells depends on SHP2 phosphatase function.

PubMed

Broxmeyer, Hal E; Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun; Chan, Rebecca J

2013-03-15

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity.

C/EBPδ deficiency sensitizes mice to ionizing radiation-induced hematopoietic and intestinal injury.

PubMed

Pawar, Snehalata A; Shao, Lijian; Chang, Jianhui; Wang, Wenze; Pathak, Rupak; Zhu, Xiaoyan; Wang, Junru; Hendrickson, Howard; Boerma, Marjan; Sterneck, Esta; Zhou, Daohong; Hauer-Jensen, Martin

2014-01-01

Knowledge of the mechanisms involved in the radiation response is critical for developing interventions to mitigate radiation-induced injury to normal tissues. Exposure to radiation leads to increased oxidative stress, DNA-damage, genomic instability and inflammation. The transcription factor CCAAT/enhancer binding protein delta (Cebpd; C/EBPδ is implicated in regulation of these same processes, but its role in radiation response is not known. We investigated the role of C/EBPδ in radiation-induced hematopoietic and intestinal injury using a Cebpd knockout mouse model. Cebpd-/- mice showed increased lethality at 7.4 and 8.5 Gy total-body irradiation (TBI), compared to Cebpd+/+ mice. Two weeks after a 6 Gy dose of TBI, Cebpd-/- mice showed decreased recovery of white blood cells, neutrophils, platelets, myeloid cells and bone marrow mononuclear cells, decreased colony-forming ability of bone marrow progenitor cells, and increased apoptosis of hematopoietic progenitor and stem cells compared to Cebpd+/+ controls. Cebpd-/- mice exhibited a significant dose-dependent decrease in intestinal crypt survival and in plasma citrulline levels compared to Cebpd+/+ mice after exposure to radiation. This was accompanied by significantly decreased expression of γ-H2AX in Cebpd-/- intestinal crypts and villi at 1 h post-TBI, increased mitotic index at 24 h post-TBI, and increase in apoptosis in intestinal crypts and stromal cells of Cebpd-/- compared to Cebpd+/+ mice at 4 h post-irradiation. This study uncovers a novel biological function for C/EBPδ in promoting the response to radiation-induced DNA-damage and in protecting hematopoietic and intestinal tissues from radiation-induced injury.

Recombinant TAT-BMI-1 fusion protein induces ex vivo expansion of human umbilical cord blood-derived hematopoietic stem cells

PubMed Central

Codispoti, Bruna; Rinaldo, Nicola; Chiarella, Emanuela; Lupia, Michela; Spoleti, Cristina Barbara; Marafioti, Maria Grazia; Aloisio, Annamaria; Scicchitano, Stefania; Giordano, Marco; Nappo, Giovanna; Lucchino, Valeria; Moore, Malcolm A.S.; Zhou, Pengbo; Mesuraca, Maria

2017-01-01

Transplantation of hematopoietic stem cells (HSCs) is a well-established therapeutic approach for numerous disorders. HSCs are typically derived from bone marrow or peripheral blood after cytokine-induced mobilization. Umbilical cord blood (CB) represents an appealing alternative HSC source, but the small amounts of the individual CB units have limited its applications. The availability of strategies for safe ex vivo expansion of CB-derived HSCs (CB-HSCs) may allow to extend the use of these cells in adult patients and to avoid the risk of insufficient engraftment or delayed hematopoietic recovery. Here we describe a system for the ex vivo expansion of CB-HSCs based on their transient exposure to a recombinant TAT-BMI-1 chimeric protein. BMI-1 belongs to the Polycomb family of epigenetic modifiers and is recognized as a central regulator of HSC self-renewal. Recombinant TAT-BMI-1 produced in bacteria was able to enter the target cells via the HIV TAT-derived protein transduction peptide covalently attached to BMI-1, and conserved its biological activity. Treatment of CB-CD34+ cells for 3 days with repeated addition of 10 nM purified TAT-BMI-1 significantly enhanced total cell expansion as well as that of primitive hematopoietic progenitors in culture. Importantly, TAT-BMI-1-treated CB-CD34+ cells displayed a consistently higher rate of multi-lineage long-term repopulating activity in primary and secondary xenotransplants in immunocompromised mice. Thus, recombinant TAT-BMI-1 may represent a novel, effective reagent for ex vivo expansion of CB-HSC for therapeutic purposes. PMID:28187462

Sumoylation of CCAAT/enhancer-binding protein α is implicated in hematopoietic stem/progenitor cell development through regulating runx1 in zebrafish.

PubMed

Yuan, Hao; Zhang, Tao; Liu, Xiaohui; Deng, Min; Zhang, Wenqing; Wen, Zilong; Chen, Saijuan; Chen, Zhu; de The, Hugues; Zhou, Jun; Zhu, Jun

2015-03-11

The small ubiquitin-related modifier (SUMO) participates in various cellular processes, including maintenance of genome integrity, nuclear transport, transcription and signal transduction. However, the biological function of sumoylation in hematopoiesis has not been fully explored. We show here that definitive hematopoietic stem/progenitor cells (HSPCs) are depleted in SUMO-deficient zebrafish embryos. Impairment of sumoylation attenuates HSPC generation and proliferation. The hyposumoylation triggered HSPC defects are CCAAT/enhancer-binding protein α (C/ebpα) dependent. Critically, a SUMO-C/ebpα fusion rescues the defective hematopoiesis in SUMO-deficient embryos, at least in part through restored runx1 expression. While C/ebpα-dependent transcription is involved in myeloid differentiation, our studies here reveal that C/ebpα sumoylation is essential for HSPC development during definitive hematopoiesis.

Sumoylation of CCAAT/enhancer-binding protein α is implicated in hematopoietic stem/progenitor cell development through regulating runx1 in zebrafish

PubMed Central

Yuan, Hao; Zhang, Tao; Liu, Xiaohui; Deng, Min; Zhang, Wenqing; Wen, Zilong; Chen, Saijuan; Chen, Zhu; de The, Hugues; Zhou, Jun; Zhu, Jun

2015-01-01

The small ubiquitin-related modifier (SUMO) participates in various cellular processes, including maintenance of genome integrity, nuclear transport, transcription and signal transduction. However, the biological function of sumoylation in hematopoiesis has not been fully explored. We show here that definitive hematopoietic stem/progenitor cells (HSPCs) are depleted in SUMO-deficient zebrafish embryos. Impairment of sumoylation attenuates HSPC generation and proliferation. The hyposumoylation triggered HSPC defects are CCAAT/enhancer-binding protein α (C/ebpα) dependent. Critically, a SUMO-C/ebpα fusion rescues the defective hematopoiesis in SUMO-deficient embryos, at least in part through restored runx1 expression. While C/ebpα-dependent transcription is involved in myeloid differentiation, our studies here reveal that C/ebpα sumoylation is essential for HSPC development during definitive hematopoiesis. PMID:25757417

Depleting dietary valine permits nonmyeloablative mouse hematopoietic stem cell transplantation.

PubMed

Taya, Yuki; Ota, Yasunori; Wilkinson, Adam C; Kanazawa, Ayano; Watarai, Hiroshi; Kasai, Masataka; Nakauchi, Hiromitsu; Yamazaki, Satoshi

2016-12-02

A specialized bone marrow microenvironment (niche) regulates hematopoietic stem cell (HSC) self-renewal and commitment. For successful donor-HSC engraftment, the niche must be emptied via myeloablative irradiation or chemotherapy. However, myeloablation can cause severe complications and even mortality. Here we report that the essential amino acid valine is indispensable for the proliferation and maintenance of HSCs. Both mouse and human HSCs failed to proliferate when cultured in valine-depleted conditions. In mice fed a valine-restricted diet, HSC frequency fell dramatically within 1 week. Furthermore, dietary valine restriction emptied the mouse bone marrow niche and afforded donor-HSC engraftment without chemoirradiative myeloablation. These findings indicate a critical role for valine in HSC maintenance and suggest that dietary valine restriction may reduce iatrogenic complications in HSC transplantation. Copyright © 2016, American Association for the Advancement of Science.

Subregional localization and characterization of Ly6aGFP-expressing hematopoietic cells in the mouse embryonic head.

PubMed

Li, Zhuan; Vink, Chris S; Mariani, Samanta A; Dzierzak, Elaine

2016-08-01

Hematopoietic cell generation in the midgestation mouse embryo occurs through the natural transdifferentiation of temporally and spatially restricted set of hemogenic endothelial cells. These cells take on hematopoietic fate in the aorta, vitelline and umbilical arteries and appear as hematopoietic cell clusters that emerge from the vascular wall. Genetic and live imaging data have supported this. Recently, the embryonic head has been shown to contain fully functional hematopoietic stem cells (HSC). By lineage tracing, cerebrovascular specific endothelial cells were shown to contribute to the postnatal mouse hematopoietic system. Since Ly6aGFP is a marker of all HSCs, some hematopoietic cluster cells and hemogenic endothelial cells in the midgestation mouse aorta, we examine here whether embryonic head HSCs and vascular endothelial cells are positive for this marker. Whereas some head vasculature, single hematopoietic cells and all HSCs are Ly6aGFP expressing, we do not find clusters of hematopoietic cells emerging from the cerebrovasculature that are characteristic of endothelial-to-hematopoietic transition. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates capacity of hematopoietic stem cells to undergo lymphocyte differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahrenhoerster, Lori S.; Tate, Everett R.; Lakatos, Peter A.

The process of hematopoiesis, characterized by long-term self-renewal and multi-potent lineage differentiation, has been shown to be regulated in part by the ligand-activated transcription factor known as the aryl hydrocarbon receptor (AHR). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a ubiquitous contaminant and the most potent AHR agonist, also modulates regulation of adult hematopoietic stem and progenitor cell (HSC/HPC) homeostasis. However, the effect of developmental TCDD exposure on early life hematopoiesis has not been fully explored. Given the inhibitory effects of TCDD on hematopoiesis and lymphocyte development, we hypothesized that in utero exposure to TCDD would alter the functional capacity of fetal HSC/HPCs to completemore » lymphocyte differentiation. To test this hypothesis, we employed a co-culture system designed to facilitate the maturation of progenitor cells to either B or T lymphocytes. Furthermore, we utilized an innovative limiting dilution assay to precisely quantify differences in lymphocyte differentiation between HSC/HPCs obtained from fetuses of dams exposed to 3 μg/kg TCDD or control. We found that the AHR is transcribed in yolk sac hematopoietic cells and is transcriptionally active as early as gestational day (GD) 7.5. Furthermore, the number of HSC/HPCs present in the fetal liver on GD 14.5 was significantly increased in fetuses whose mothers were exposed to TCDD throughout pregnancy. Despite this increase in HSC/HPC cell number, B and T lymphocyte differentiation is decreased by approximately 2.5 fold. These findings demonstrate that inappropriate developmental AHR activation in HSC/HPCs adversely impacts lymphocyte differentiation and may have consequences for lymphocyte development in the bone marrow and thymus later in life.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xingbing, E-mail: wangxingbing91@hotmail.com; Cheng, Qiansong; Li, Lailing

Bone marrow derived-mesenchymal stromal cells (BM-MSCs) are multipotent, nonhematopoietic progenitors in a hematopoietic microenvironment and indispensable for regulating hematopoiesis. Several studies have reported that toll-like receptors (TLRs) are expressed in mesenchymal stromal cells (MSCs) to modulate their biological functions. In this study, we investigated the possible role(s) of TLRs in mediating the hematopoiesis-supporting role of human BM-MSCs. Human BM-MSCs were analyzed for mRNA expression of TLR1-10 by reverse transcription-polymerase chain reaction. TLR1-6, but not TLR7-10 were expressed by BM-MSCs. The protein expression of TLR2 and TLR4 was also confirmed by flow cytometry. We further explored the role of TLR2 andmore » TLR4 in mediating the capacity of BM-MSCs to support the proliferation and differentiation of CD34{sup +} hematopoietic stem/progenitor cells obtained from cord blood. BM-MSCs increased proliferation of CD34{sup +} cells and promoted the differentiation towards the myeloid lineage 7 or 14 days after co-culture, as well as colony formation by those cells and the production of interleukin 1 (IL-1), IL-8, IL-11, stem cell factor (SCF), granulocyte colony-stimulating factor (CSF), macrophage CSF and granulocyte-macrophage CSF, if MSCs had been stimulated with TLR2 agonist (PAM{sub 3}CSK{sub 4}) or TLR4 agonist (LPS). Interestingly, although these effects were elevated in a different degree, a synergistic effect was not observed in BM-MSCs co-stimulated with PAM{sub 3}CSK{sub 4} and LPS. Together, our findings suggest that TLR2 and TLR4 signaling may indirectly regulate hematopoiesis by modulating BM-MSCs' functions. The increased hematopoietic proliferation and differentiation could be mediated, at least in part, by augmented hematopoiesis-related cytokine production of BM-MSCs.« less

MYCN Transgenic Zebrafish Model with the Characterization of Acute Myeloid Leukemia and Altered Hematopoiesis

PubMed Central

Shen, Li-Jing; Chen, Fang-Yuan; Zhang, Yong; Cao, Lan-Fang; Kuang, Ying; Zhong, Min; Wang, Ting; Zhong, Hua

2013-01-01

Background Amplification of MYCN (N-Myc) oncogene has been reported as a frequent event and a poor prognostic marker in human acute myeloid leukemia (AML). The molecular mechanisms and transcriptional networks by which MYCN exerts its influence in AML are largely unknown. Methodology/Principal Findings We introduced murine MYCN gene into embryonic zebrafish through a heat-shock promoter and established the stable germline Tg(MYCN:HSE:EGFP) zebrafish. N-Myc downstream regulated gene 1 (NDRG1), negatively controlled by MYCN in human and functionally involved in neutrophil maturation, was significantly under-expressed in this model. Using peripheral blood smear detection, histological section and flow cytometric analysis of single cell suspension from kidney and spleen, we found that MYCN overexpression promoted cell proliferation, enhanced the repopulating activity of myeloid cells and the accumulation of immature hematopoietic blast cells. MYCN enhanced primitive hematopoiesis by upregulating scl and lmo2 expression and promoted myelopoiesis by inhibiting gata1 expression and inducing pu.1, mpo expression. Microarray analysis identified that cell cycle, glycolysis/gluconeogenesis, MAPK/Ras, and p53-mediated apoptosis pathways were upregulated. In addition, mismatch repair, transforming and growth factor β (TGFβ) were downregulated in MYCN-overexpressing blood cells (p<0.01). All of these signaling pathways are critical in the proliferation and malignant transformation of blood cells. Conclusion/Significance The above results induced by overexpression of MYCN closely resemble the main aspects of human AML, suggesting that MYCN plays a role in the etiology of AML. MYCN reprograms hematopoietic cell fate by regulating NDRG1 and several lineage-specific hematopoietic transcription factors. Therefore, this MYCN transgenic zebrafish model facilitates dissection of MYCN-mediated signaling in vivo, and enables high-throughput scale screens to identify the potential therapeutic targets. PMID:23554972

Hematopoietic Protein-1 Regulates the Actin Membrane Skeleton and Membrane Stability in Murine Erythrocytes

PubMed Central

Chan, Maia M.; Wooden, Jason M.; Tsang, Mark; Gilligan, Diana M.; Hirenallur-S, Dinesh K.; Finney, Greg L.; Rynes, Eric; MacCoss, Michael; Ramirez, Julita A.; Park, Heon; Iritani, Brian M.

2013-01-01

Hematopoietic protein-1 (Hem-1) is a hematopoietic cell specific member of the WAVE (Wiskott-Aldrich syndrome verprolin-homologous protein) complex, which regulates filamentous actin (F-actin) polymerization in many cell types including immune cells. However, the roles of Hem-1 and the WAVE complex in erythrocyte biology are not known. In this study, we utilized mice lacking Hem-1 expression due to a non-coding point mutation in the Hem1 gene to show that absence of Hem-1 results in microcytic, hypochromic anemia characterized by abnormally shaped erythrocytes with aberrant F-actin foci and decreased lifespan. We find that Hem-1 and members of the associated WAVE complex are normally expressed in wildtype erythrocyte progenitors and mature erythrocytes. Using mass spectrometry and global proteomics, Coomassie staining, and immunoblotting, we find that the absence of Hem-1 results in decreased representation of essential erythrocyte membrane skeletal proteins including α- and β- spectrin, dematin, p55, adducin, ankyrin, tropomodulin 1, band 3, and band 4.1. Hem1−/− erythrocytes exhibit increased protein kinase C-dependent phosphorylation of adducin at Ser724, which targets adducin family members for dissociation from spectrin and actin, and subsequent proteolysis. Increased adducin Ser724 phosphorylation in Hem1−/− erythrocytes correlates with decreased protein expression of the regulatory subunit of protein phosphatase 2A (PP2A), which is required for PP2A-dependent dephosphorylation of PKC targets. These results reveal a novel, critical role for Hem-1 in the homeostasis of structural proteins required for formation and stability of the actin membrane skeleton in erythrocytes. PMID:23424621

Aberrant expression of NKL homeobox gene HLX in Hodgkin lymphoma.

PubMed

Nagel, Stefan; Pommerenke, Claudia; Meyer, Corinna; Kaufmann, Maren; MacLeod, Roderick A F; Drexler, Hans G

2018-03-06

NKL homeobox genes are basic regulators of cell and tissue differentiation, many acting as oncogenes in T-cell leukemia. Recently, we described an hematopoietic NKL-code comprising six particular NKL homeobox genes expressed in hematopoietic stem cells and lymphoid progenitors, unmasking their physiological roles in the development of these cell types. Hodgkin lymphoma (HL) is a B-cell malignancy showing aberrant activity of several developmental genes resulting in disturbed B-cell differentiation. To examine potential concordances in abnormal lymphoid differentiation of T- and B-cell malignancies we analyzed the expression of the hematopoietic NKL-code associated genes in HL, comprising HHEX, HLX, MSX1, NKX2-3, NKX3-1 and NKX6-3. Our approach revealed aberrant HLX activity in 8 % of classical HL patients and additionally in HL cell line L-540. Accordingly, to identify upstream regulators and downstream target genes of HLX we used L-540 cells as a model and performed chromosome and genome analyses, comparative expression profiling and functional assays via knockdown and overexpression experiments therein. These investigations excluded chromosomal rearrangements of the HLX locus at 1q41 and demonstrated that STAT3 operated directly as transcriptional activator of the HLX gene. Moreover, subcellular analyses showed highly enriched STAT3 protein in the nucleus of L-540 cells which underwent cytoplasmic translocation by repressing deacetylation. Finally, HLX inhibited transcription of B-cell differentiation factors MSX1, BCL11A and SPIB and of pro-apoptotic factor BCL2L11/BIM, thereby suppressing Etoposide-induced cell death. Collectively, we propose that aberrantly expressed NKL homeobox gene HLX is part of a pathological gene network in HL, driving deregulated B-cell differentiation and survival.

Increased Expression of PcG Protein YY1 Negatively Regulates B Cell Development while Allowing Accumulation of Myeloid Cells and LT-HSC Cells

PubMed Central

Pan, Xuan; Jones, Morgan; Jiang, Jie; Zaprazna, Kristina; Yu, Duonan; Pear, Warren; Maillard, Ivan; Atchison, Michael L.

2012-01-01

Ying Yang 1 (YY1) is a multifunctional Polycomb Group (PcG) transcription factor that binds to multiple enhancer binding sites in the immunoglobulin (Ig) loci and plays vital roles in early B cell development. PcG proteins have important functions in hematopoietic stem cell renewal and YY1 is the only mammalian PcG protein with DNA binding specificity. Conditional knock-out of YY1 in the mouse B cell lineage results in arrest at the pro-B cell stage, and dosage effects have been observed at various YY1 expression levels. To investigate the impact of elevated YY1 expression on hematopoetic development, we utilized a mouse in vivo bone marrow reconstitution system. We found that mouse bone marrow cells expressing elevated levels of YY1 exhibited a selective disadvantage as they progressed from hematopoietic stem/progenitor cells to pro-B, pre-B, immature B and re-circulating B cell stages, but no disadvantage of YY1 over-expression was observed in myeloid lineage cells. Furthermore, mouse bone marrow cells expressing elevated levels of YY1 displayed enrichment for cells with surface markers characteristic of long-term hematopoietic stem cells (HSC). YY1 expression induced apoptosis in mouse B cell lines in vitro, and resulted in down-regulated expression of anti-apoptotic genes Bcl-xl and NFκB2, while no impact was observed in a mouse myeloid line. B cell apoptosis and LT-HSC enrichment induced by YY1 suggest that novel strategies to induce YY1 expression could have beneficial effects in the treatment of B lineage malignancies while preserving normal HSCs. PMID:22292011

Reduced hematopoietic stem cell frequency predicts outcome in acute myeloid leukemia.

PubMed

Wang, Wenwen; Stiehl, Thomas; Raffel, Simon; Hoang, Van T; Hoffmann, Isabel; Poisa-Beiro, Laura; Saeed, Borhan R; Blume, Rachel; Manta, Linda; Eckstein, Volker; Bochtler, Tilmann; Wuchter, Patrick; Essers, Marieke; Jauch, Anna; Trumpp, Andreas; Marciniak-Czochra, Anna; Ho, Anthony D; Lutz, Christoph

2017-09-01

In patients with acute myeloid leukemia and low percentages of aldehyde-dehydrogenase-positive cells, non-leukemic hematopoietic stem cells can be separated from leukemic cells. By relating hematopoietic stem cell frequencies to outcome we detected poor overall- and disease-free survival of patients with low hematopoietic stem cell frequencies. Serial analysis of matched diagnostic and follow-up samples further demonstrated that hematopoietic stem cells increased after chemotherapy in patients who achieved durable remissions. However, in patients who eventually relapsed, hematopoietic stem cell numbers decreased dramatically at the time of molecular relapse demonstrating that hematopoietic stem cell levels represent an indirect marker of minimal residual disease, which heralds leukemic relapse. Upon transplantation in immune-deficient mice cases with low percentages of hematopoietic stem cells of our cohort gave rise to leukemic or no engraftment, whereas cases with normal hematopoietic stem cell levels mostly resulted in multi-lineage engraftment. Based on our experimental data, we propose that leukemic stem cells have increased niche affinity in cases with low percentages of hematopoietic stem cells. To validate this hypothesis, we developed new mathematical models describing the dynamics of healthy and leukemic cells under different regulatory scenarios. These models suggest that the mechanism leading to decreases in hematopoietic stem cell frequencies before leukemic relapse must be based on expansion of leukemic stem cells with high niche affinity and the ability to dislodge hematopoietic stem cells. Thus, our data suggest that decreasing numbers of hematopoietic stem cells indicate leukemic stem cell persistence and the emergence of leukemic relapse. Copyright© 2017 Ferrata Storti Foundation.

HRV signaling in airway epithelial cells is regulated by ITAM-mediated recruitment and activation of Syk.

PubMed

Lau, Christine; Castellanos, Patricia; Ranev, Dimitre; Wang, Xiaomin; Chow, Chung-Wai

2011-05-01

Human rhinovirus (HRV), cause of the common cold, is a leading cause of exacerbations of asthma and chronic obstruction pulmonary disease (COPD). Binding of HRV to ICAM (intercellular adhesion molecule)-1, its major receptor, induces a profound inflammatory response from airway epithelial cells. My laboratory has identified Syk tyrosine kinase to be an early regulator of HRV-ICAM-1 signalling: Syk mediates replication-independent p38 mitogen-activated protein (MAP) kinase and phosphatidyl-inositol 3 (PI3)-kinase activation, interleukin (IL)-8 expression, as well as HRV internalization via clathrin-mediated endocytosis. Syk activation is accompanied by formation of a protein complex consisting of ICAM-1, ezrin and Syk at the plasma membrane. However, the molecular mechanisms that regulate this process are not understood. In this report, we investigated the role of the Syk-SH2 domains and the ezrin ITAM (immuno-tyrosine activation motif)-like motif in HRV-induced cell activation using the human BEAS-2B airway epithelial cells. Our observations suggest that the ezrin-ITAM plays a role in Syk recruitment and activation by binding to the Syk tandem SH2 domains, as originally described in the canonical ITAM-mediating signal transduction pathway in hematopoietic cells. This report is the first to demonstrate ITAM-mediated signaling in non-hematopoietic cells, suggesting that this signaling paradigm may be more ubiquitous than previously recognized.

Statins induce apoptosis through inhibition of Ras signaling pathways and enhancement of Bim and p27 expression in human hematopoietic tumor cells.

PubMed

Fujiwara, Daichiro; Tsubaki, Masanobu; Takeda, Tomoya; Tomonari, Yoshika; Koumoto, Yu-Ichi; Sakaguchi, Katsuhiko; Nishida, Shozo

2017-10-01

Recently, statins have been demonstrated to improve cancer-related mortality or prognosis in patients of various cancers. However, the details of the apoptosis-inducing mechanisms remain unknown. This study showed that the induction of apoptosis by statins in hematopoietic tumor cells is mediated by mitochondrial apoptotic signaling pathways, which are activated by the suppression of mevalonate or geranylgeranyl pyrophosphate biosynthesis. In addition, statins decreased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin through suppressing Ras prenylation. Furthermore, inhibition of extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin by statins induced Bim expression via inhibition of Bim phosphorylation and ubiquitination and cell-cycle arrest at G1 phase via enhancement of p27 expression. Moreover, combined treatment of U0126, a mitogen-activated protein kinase kinase 1/2 inhibitor, and rapamycin, a mammalian target of rapamycin inhibitor, induced Bim and p27 expressions. The present results suggested that statins induce apoptosis by decreasing the mitochondrial transmembrane potential, increasing the activation of caspase-9 and caspase-3, enhancing Bim expression, and inducing cell-cycle arrest at G1 phase through inhibition of Ras/extracellular signal-regulated kinase and Ras/mammalian target of rapamycin pathways. Therefore, our findings support the use of statins as potential anticancer agents or concomitant drugs of adjuvant therapy.

Cord blood in regenerative medicine: do we need immune suppression?

PubMed Central

Riordan, Neil H; Chan, Kyle; Marleau, Annette M; Ichim, Thomas E

2007-01-01

Cord blood is currently used as an alternative to bone marrow as a source of stem cells for hematopoietic reconstitution after ablation. It is also under intense preclinical investigation for a variety of indications ranging from stroke, to limb ischemia, to myocardial regeneration. A major drawback in the current use of cord blood is that substantial morbidity and mortality are associated with pre-transplant ablation of the recipient hematopoietic system. Here we raise the possibility that due to unique immunological properties of both the stem cell and non-stem cell components of cord blood, it may be possible to utilize allogeneic cells for regenerative applications without needing to fully compromise the recipient immune system. Issues raised will include: graft versus host potential, the immunogeneicity of the cord blood graft, and the parallels between cord blood transplantation and fetal to maternal trafficking. The previous use of unmatched cord blood in absence of any immune ablation, as well as potential steps for widespread clinical implementation of allogeneic cord blood grafts will also be discussed. PMID:17261200

In vivo Clonal Tracking of Hematopoietic Stem and Progenitor Cells Marked by Five Fluorescent Proteins using Confocal and Multiphoton Microscopy

PubMed Central

Malide, Daniela; Métais, Jean-Yves; Dunbar, Cynthia E.

2014-01-01

We developed and validated a fluorescent marking methodology for clonal tracking of hematopoietic stem and progenitor cells (HSPCs) with high spatial and temporal resolution to study in vivo hematopoiesis using the murine bone marrow transplant experimental model. Genetic combinatorial marking using lentiviral vectors encoding fluorescent proteins (FPs) enabled cell fate mapping through advanced microscopy imaging. Vectors encoding five different FPs: Cerulean, EGFP, Venus, tdTomato, and mCherry were used to concurrently transduce HSPCs, creating a diverse palette of color marked cells. Imaging using confocal/two-photon hybrid microscopy enables simultaneous high resolution assessment of uniquely marked cells and their progeny in conjunction with structural components of the tissues. Volumetric analyses over large areas reveal that spectrally coded HSPC-derived cells can be detected non-invasively in various intact tissues, including the bone marrow (BM), for extensive periods of time following transplantation. Live studies combining video-rate multiphoton and confocal time-lapse imaging in 4D demonstrate the possibility of dynamic cellular and clonal tracking in a quantitative manner. PMID:25145579

Transcription regulation by distal enhancers

PubMed Central

Stadhouders, Ralph; van den Heuvel, Anita; Kolovos, Petros; Jorna, Ruud; Leslie, Kris; Grosveld, Frank; Soler, Eric

2012-01-01

Genome-wide chromatin profiling efforts have shown that enhancers are often located at large distances from gene promoters within the noncoding genome. Whereas enhancers can stimulate transcription initiation by communicating with promoters via chromatin looping mechanisms, we propose that enhancers may also stimulate transcription elongation by physical interactions with intronic elements. We review here recent findings derived from the study of the hematopoietic system. PMID:22771987

Loss of the hematopoietic stem cell factor GATA2 in the osteogenic lineage impairs trabecularization and mechanical strength of bone.

PubMed

Tolkachov, Alexander; Fischer, Cornelius; Ambrosi, Thomas H; Bothe, Melissa; Han, Chung-Ting; Muenzner, Matthias; Mathia, Susanne; Salminen, Marjo; Seifert, Georg; Thiele, Mario; Duda, Georg N; Meijsing, Sebastiaan H; Sauer, Sascha; Schulz, Tim J; Schupp, Michael

2018-03-26

The transcription factor GATA2 is required for expansion and differentiation of hematopoietic stem cells (HSCs). In mesenchymal stem cells (MSCs) GATA2 blocks adipogenesis, but its biological relevance and underlying genomic events are unknown. We report a dual function of GATA2 in bone homeostasis. GATA2 in MSCs binds near genes involved in skeletal system development and co-localizes with motifs for FOX and HOX transcription factors, known regulators of skeletal development. Ectopic GATA2 blocks osteoblastogenesis by interfering with SMAD1/5/8 activation. MSC-specific deletion of GATA2 in mice increases numbers and differentiation capacity of bone-derived precursors, resulting in elevated bone formation. Surprisingly, MSC-specific GATA2 deficiency impairs trabecularization and mechanical strength of bone, involving reduced MSC expression of the osteoclast inhibitor osteoprotegerin and increased osteoclast numbers. Thus, GATA2 affects bone turnover via MSC-autonomous and indirect effects. By regulating bone trabecularization, GATA2 expression in the osteogenic lineage may contribute to the anatomical and cellular microenvironment of the HSC niche required for hematopoiesis. Copyright © 2018 American Society for Microbiology.

GATA Factor-G-Protein-Coupled Receptor Circuit Suppresses Hematopoiesis

PubMed Central

Gao, Xin; Wu, Tongyu; Johnson, Kirby D.; Lahvic, Jamie L.; Ranheim, Erik A.; Zon, Leonard I.; Bresnick, Emery H.

2016-01-01

Summary Hematopoietic stem cells (HSCs) originate from hemogenic endothelium within the aorta-gonad-mesonephros (AGM) region of the mammalian embryo. The relationship between genetic circuits controlling stem cell genesis and multi-potency is not understood. A Gata2 cis element (+9.5) enhances Gata2 expression in the AGM and induces the endothelial to HSC transition. We demonstrated that GATA-2 rescued hematopoiesis in +9.5−/− AGMs. As G-protein-coupled receptors (GPCRs) are the most common targets for FDA-approved drugs, we analyzed the GPCR gene ensemble to identify GATA-2-regulated GPCRs. Of the 20 GATA-2-activated GPCR genes, four were GATA-1-activated, and only Gpr65 expression resembled Gata2. Contrasting with the paradigm in which GATA-2-activated genes promote hematopoietic stem and progenitor cell genesis/function, our mouse and zebrafish studies indicated that GPR65 suppressed hematopoiesis. GPR65 established repressive chromatin at the +9.5 site, restricted occupancy by the activator Scl/TAL1, and repressed Gata2 transcription. Thus, a Gata2 cis element creates a GATA-2-GPCR circuit that limits positive regulators that promote hematopoiesis. PMID:26905203

Regulator of differentiation 1 (ROD1) binds to the amphipathic C-terminal peptide of thrombospondin-4 and is involved in its mitogenic activity.

PubMed

Sadvakassova, Gulzhakhan; Dobocan, Monica C; Difalco, Marcos R; Congote, Luis F

2009-09-01

The matrix protein thrombospondin-4 has an acidic amphipathic C-terminal peptide (C21) which stimulates erythroid cell proliferation. Here we show that C21 stimulates red cell formation in anemic mice in vivo. In vitro experiments indicated that the peptide-mediated increase of erythroid colony formation in cultures of human CD34+ hematopoietic progenitor cells was possible only under continuous presence of erythropoietin. In the absence of this cytokine, C21 stimulated exclusively myeloid colony formation. Therefore, the peptide is not a specific erythroid differentiation factor. In fact, it is mitogenic in non-erythroid cells, such as skin fibroblasts and kidney epithelial cells. In erythroleukemic TF-1 cells, it actually decreased the production of the erythroid differentiation marker glycophorin A. C21-affinity chromatography revealed regulator of differentiation 1 (ROD1) as a major C21-binding protein. ROD1 is the hematopoietic cell paralog of polypyrimidine tract binding proteins (PTBs), RNA splice regulators which regulate differentiation by repressing tissue-specific exons. ROD1 binding to C21 was strongly inhibited by synthetic RNAs in the order poly A > poly U > poly G = poly C and was weakly inhibited by a synthetic phosphorylated peptide mimicking the C-terminal domain of RNA polymerase II. Cellular overexpression or knockdown experiments of ROD1 suggest a role for this protein in the mitogenic activity of C21. Since the nuclear proteins ROD1 and PTBs regulate differentiation at a posttranscriptional level and there is a fast nuclear uptake of C21, we put forward the idea that the peptide is internalized, goes to the nucleus and maintains cells in a proliferative state by supporting ROD1-mediated inhibition of differentiation.

The homeobox gene CDX2 is aberrantly expressed in most cases of acute myeloid leukemia and promotes leukemogenesis

PubMed Central

Scholl, Claudia; Bansal, Dimple; Döhner, Konstanze; Eiwen, Karina; Huntly, Brian J.P.; Lee, Benjamin H.; Rücker, Frank G.; Schlenk, Richard F.; Bullinger, Lars; Döhner, Hartmut; Gilliland, D. Gary; Fröhling, Stefan

2007-01-01

The homeobox transcription factor CDX2 plays an important role in embryonic development and regulates the proliferation and differentiation of intestinal epithelial cells in the adult. We have found that CDX2 is expressed in leukemic cells of 90% of patients with acute myeloid leukemia (AML) but not in hematopoietic stem and progenitor cells derived from normal individuals. Stable knockdown of CDX2 expression by RNA interference inhibited the proliferation of various human AML cell lines and strongly reduced their clonogenic potential in vitro. Primary murine hematopoietic progenitor cells transduced with Cdx2 acquired serial replating activity, were able to be continuously propagated in liquid culture, generated fully penetrant and transplantable AML in BM transplant recipients, and displayed dysregulated expression of Hox family members in vitro and in vivo. These results demonstrate that aberrant expression of the developmental regulatory gene CDX2 in the adult hematopoietic compartment is a frequent event in the pathogenesis of AML; suggest a role for CDX2 as part of a common effector pathway that promotes the proliferative capacity and self-renewal potential of myeloid progenitor cells; and support the hypothesis that CDX2 is responsible, in part, for the altered HOX gene expression that is observed in most cases of AML. PMID:17347684

A Cell Kinetic Model of Granulocytopoiesis Under Radiation Exposure: Extension from Murines to Canines and Humans

NASA Technical Reports Server (NTRS)

Hu, Shaowen; Cucinotta, Francis A.

2009-01-01

Space radiation poses significant challenges to space travel, and it is essential to understand the possible adverse effects from space radiation exposure to the radiosensitive organ systems that are important for immediate survival of human, e.g., the hematopoietic system. In this presentation a biomathematical model of granulocytopoiesis is described and used to analyze the blood granulocyte changes seen in the blood of mammalians under continuous and acute radiation exposure. This is one of a set of hematopoietic models that have been successfully utilized to simulate and interpret the experimental data of acute and chronic radiation on rodents. We discuss the underlying implicit regulation mechanism and the biological relevance of the kinetic parameters estimation method. Extension of the model to predictions in dogs and humans systems indicates that the modeling results are consistent with the cumulative experimental and empirical data from various sources. This implies the potential to integrate the models into one united system for monitoring the hematopoietic response of various species under irradiation. Based on the evidence of threshold responses of dogs to extended periods of low daily dose exposures, we discuss the potential health risks of the space traveler under chronic stress of low-dose irradiation and the possibly encountered Solar Particle Events.

Single-cell transcriptional analysis of normal, aberrant, and malignant hematopoiesis in zebrafish.

PubMed

Moore, Finola E; Garcia, Elaine G; Lobbardi, Riadh; Jain, Esha; Tang, Qin; Moore, John C; Cortes, Mauricio; Molodtsov, Aleksey; Kasheta, Melissa; Luo, Christina C; Garcia, Amaris J; Mylvaganam, Ravi; Yoder, Jeffrey A; Blackburn, Jessica S; Sadreyev, Ruslan I; Ceol, Craig J; North, Trista E; Langenau, David M

2016-05-30

Hematopoiesis culminates in the production of functionally heterogeneous blood cell types. In zebrafish, the lack of cell surface antibodies has compelled researchers to use fluorescent transgenic reporter lines to label specific blood cell fractions. However, these approaches are limited by the availability of transgenic lines and fluorescent protein combinations that can be distinguished. Here, we have transcriptionally profiled single hematopoietic cells from zebrafish to define erythroid, myeloid, B, and T cell lineages. We also used our approach to identify hematopoietic stem and progenitor cells and a novel NK-lysin 4(+) cell type, representing a putative cytotoxic T/NK cell. Our platform also quantified hematopoietic defects in rag2(E450fs) mutant fish and showed that these fish have reduced T cells with a subsequent expansion of NK-lysin 4(+) cells and myeloid cells. These data suggest compensatory regulation of the innate immune system in rag2(E450fs) mutant zebrafish. Finally, analysis of Myc-induced T cell acute lymphoblastic leukemia showed that cells are arrested at the CD4(+)/CD8(+) cortical thymocyte stage and that a subset of leukemia cells inappropriately reexpress stem cell genes, including bmi1 and cmyb In total, our experiments provide new tools and biological insights into single-cell heterogeneity found in zebrafish blood and leukemia. © 2016 Moore et al.

Update on thrombopoietin in preclinical and clinical trials.

PubMed

Miyazaki, H

1998-05-01

Thrombopoietin, also termed the c-Mpl ligand, is a lineage-dominant hematopoietic factor that primarily regulates megakaryopoiesis and thrombopoiesis. Treatment of normal animals with recombinant human megakaryocyte growth and development factor, a truncated molecule of the c-Mpl ligand, which is modified with polyethylene glycol (PEG-rHuMGDF), and glycosylated recombinant thrombopoietin stimulates the expansion of bone marrow megakaryocytes and their progenitors, and greatly enhances the production of morphologically and functionally normal platelets. In contrast, this cytokine has only minimal effects on peripheral leukocyte and erythrocyte counts. In myelosuppressed animals, PEG-rHuMGDF or glycosylated thrombopoietin accelerates multilineage hematopoietic recovery effectively improving thrombocytopenia and, in most models, leukopenia (or neutropenia) and anemia. In addition to daily multiple injections, even a single injection of PEG-rHuMGDF after myelosuppressive treatment is fully effective for hematopoietic recovery. In clinical trials, PEG-rHuMGDF or glycosylated recombinant human thrombopoietin potently stimulates thrombopoiesis in cancer patients before chemotherapy. The administration of PEG-rHuMGDF alone or in combination with recombinant human granulocyte colony-stimulating factor (rhG-CSF) reduces the duration of severe thrombocytopenia and in some cases platelet nadirs in patients with advanced cancers after dose-intensive chemotherapy. The recombinant hormone is well-tolerated with little drug-related toxicity.

Evidence that β7 Integrin Regulates Hematopoietic Stem Cell Homing and Engraftment Through Interaction with MAdCAM-1.

PubMed

Murakami, Jodi L; Xu, Baohui; Franco, Christopher B; Hu, Xingbin; Galli, Stephen J; Weissman, Irving L; Chen, Ching-Cheng

2016-01-01

α4β7 integrin is a cell adhesion receptor that is crucial for the migration of hematopoietic progenitors and mature effector cells in the periphery, but its role in adult hematopoiesis is controversial. We identified a subset of hematopoietic stem cells (HSCs) in the bone marrow (BM) that expressed β7 integrin. These β7(+) HSCs were capable of multilineage, long-term reconstitution and had an inherent competitive advantage over β7(-) HSCs. On the other hand, HSCs that lacked β7 integrin (β7KO) had reduced engraftment potential. Interestingly, quantitative RT-PCR and flow cytometry revealed that β7KO HSCs expressed lower levels of the chemokine receptor CXCR4. Accordingly, β7KO HSCs exhibited impaired migration abilities in vitro and BM homing capabilities in vivo. Lethal irradiation induced expression of the α4β7 integrin ligand-mucosal addressin cell adhesion molecule-1 (MAdCAM-1) on BM endothelial cells. Moreover, blocking MAdCAM-1 reduced the homing of HSCs and impaired the survival of recipient mice. Altogether, these data indicate that β7 integrin, when expressed by HSCs, interacted with its endothelial ligand MAdCAM-1 in the BM microenvironment, thereby promoting HSC homing and engraftment.

Research progress on the proliferation and differentiation of

NASA Astrophysics Data System (ADS)

An, A.; Tan, B.

Space environments such as microgravity magnetic field radiation and heavy metal ions affects the development and functions of human and mammalian cells To study these influences and the corresponding metabolisms is in favour of knowing about the development and differentiation process of organism cells In recent years researches on the differentiation of stem cells induced in vitro provide a new pathway for the repair of tissue lesion and therapy of human diseases Stem cells are potential in capable of differentiating into different functional cells But there has no reliable methods to induce the stem cells differentiating forward specific cells and to gain enough cells for transplantation which limited their application on clinical therapy It has been indicated that microgravity influenced embryonic development hematopoietic and mesenchymal stem cells and so on Hematopoietic stem cell migration and its differentiation were affected by microgravity The specific differentiation of hematopoietic stem cells was inhibited under microgravity The expression of proteins regulating cell cycle period also changed Mesenchymal stem cells provide a source of cells for the repair of musculoskeletal tissue in ground experiment While under microgravity the proliferation and differentiation of mesenchymal stem cells were influenced along with the differentiated cells function changed Furthermore in the differentiation process of stem cells under microgravity the mechanism of signal transport was also affected and the specific differentiation

Single-cell transcriptional analysis of normal, aberrant, and malignant hematopoiesis in zebrafish

PubMed Central

Garcia, Elaine G.; Lobbardi, Riadh; Jain, Esha; Tang, Qin; Moore, John C.; Cortes, Mauricio; Molodtsov, Aleksey; Kasheta, Melissa; Luo, Christina C.; Garcia, Amaris J.; Mylvaganam, Ravi; Yoder, Jeffrey A.; Blackburn, Jessica S.; Sadreyev, Ruslan I.; Ceol, Craig J.; North, Trista E.

2016-01-01

Hematopoiesis culminates in the production of functionally heterogeneous blood cell types. In zebrafish, the lack of cell surface antibodies has compelled researchers to use fluorescent transgenic reporter lines to label specific blood cell fractions. However, these approaches are limited by the availability of transgenic lines and fluorescent protein combinations that can be distinguished. Here, we have transcriptionally profiled single hematopoietic cells from zebrafish to define erythroid, myeloid, B, and T cell lineages. We also used our approach to identify hematopoietic stem and progenitor cells and a novel NK-lysin 4+ cell type, representing a putative cytotoxic T/NK cell. Our platform also quantified hematopoietic defects in rag2E450fs mutant fish and showed that these fish have reduced T cells with a subsequent expansion of NK-lysin 4+ cells and myeloid cells. These data suggest compensatory regulation of the innate immune system in rag2E450fs mutant zebrafish. Finally, analysis of Myc-induced T cell acute lymphoblastic leukemia showed that cells are arrested at the CD4+/CD8+ cortical thymocyte stage and that a subset of leukemia cells inappropriately reexpress stem cell genes, including bmi1 and cmyb. In total, our experiments provide new tools and biological insights into single-cell heterogeneity found in zebrafish blood and leukemia. PMID:27139488

VE-cadherin expression allows identification of a new class of hematopoietic stem cells within human embryonic liver.

PubMed

Oberlin, Estelle; Fleury, Maud; Clay, Denis; Petit-Cocault, Laurence; Candelier, Jean-Jacques; Mennesson, Benoît; Jaffredo, Thierry; Souyri, Michèle

2010-11-25

Edification of the human hematopoietic system during development is characterized by the production of waves of hematopoietic cells separated in time, formed in distinct embryonic sites (ie, yolk sac, truncal arteries including the aorta, and placenta). The embryonic liver is a major hematopoietic organ wherein hematopoietic stem cells (HSCs) expand, and the future, adult-type, hematopoietic cell hierarchy becomes established. We report herein the identification of a new, transient, and rare cell population in the human embryonic liver, which coexpresses VE-cadherin, an endothelial marker, CD45, a pan-hematopoietic marker, and CD34, a common endothelial and hematopoietic marker. This population displays an outstanding self-renewal, proliferation, and differentiation potential, as detected by in vitro and in vivo hematopoietic assays compared with its VE-cadherin negative counterpart. Based on VE-cadherin expression, our data demonstrate the existence of 2 phenotypically and functionally separable populations of multipotent HSCs in the human embryo, the VE-cadherin(+) one being more primitive than the VE-cadherin(-) one, and shed a new light on the hierarchical organization of the embryonic liver HSC compartment.

Transcriptome analysis of rainbow trout infected with high and low virulence strains of Infectious hematopoietic necrosis virus

USGS Publications Warehouse

Purcell, Maureen K.; Marjara, Inderjit Singh; Batts, William; Kurath, Gael; Hansen, John D.

2010-01-01

There are three main genetic lineages or genogroups of Infectious hematopoietic necrosis virus (IHNV) in N. America. Strains representing the M genogroup are more virulent in rainbow trout relative to the U genogroup. In this study, we used microarray analysis to evaluate potential mechanisms responsible for host-specific virulence in rainbow trout that were given intraperitoneal injections of buffer or a representative M or U type virus strain. Reverse transcriptase quantitative PCR (RT-qPCR) was used to assess viral load and gene expression of select immune genes. Viral load was significantly higher in trout infected with the M virus starting at 24 h post-infection (p.i.) and continuing until 72 h p.i. Microarray analysis of the 48 h time point revealed 153 up-regulated and 248 down-regulated features in response to M virus infection but only 62 up-regulated and 49 down-regulated features following U virus infection. Translation and transcription features were among the most frequent down-regulated features in response to M virus infection and may be associated with the host cell shutoff phenomenon. A greater host cell shutoff response by the M virus may facilitate subversion of the host cell transcriptional machinery and enhance viral replication, suggesting the M virus may be better optimized to manipulate the rainbow trout transcriptional and translational machinery. Anti-viral associated features were the most commonly up-regulated features. A common set of features were up-regulated in both the M and U infection groups, but were induced to a higher magnitude in the M infection group. Gene expression of the anti-viral genes Mx-1 and Vig-1 was correlated but not entirely dependent on viral load in the anterior kidney. Slower replication of the U virus may allow the host more time to induce protective anti-viral immune mechanisms.

MicroRNA and Transcriptomic Profiling Showed miRNA-Dependent Impairment of Systemic Regulation and Synthesis of Biomolecules in Rag2 KO Mice.

PubMed

Reza, Abu Musa Md Talimur; Choi, Yun-Jung; Kim, Jin-Hoi

2018-02-27

The Rag2 knockout (KO) mouse is a well-established immune-compromised animal model for biomedical research. A comparative study identified the deregulated expression of microRNAs (miRNAs) and messenger RNAs (mRNAs) in Rag2 KO mice. However, the interaction between deregulated genes and miRNAs in the alteration of systemic (cardiac, renal, hepatic, nervous, and hematopoietic) regulations and the synthesis of biomolecules (such as l-tryptophan, serotonin, melatonin, dopamine, alcohol, noradrenaline, putrescine, and acetate) are unclear. In this study, we analyzed both miRNA and mRNA expression microarray data from Rag2 KO and wild type mice to investigate the possible role of miRNAs in systemic regulation and biomolecule synthesis. A notable finding obtained from this analysis is that the upregulation of several genes which are target molecules of the downregulated miRNAs in Rag2 KO mice, can potentially trigger the degradation of l-tryptophan, thereby leading to the systemic impairment and alteration of biomolecules synthesis as well as changes in behavioral patterns (such as stress and fear responses, and social recognition memory) in Rag2 gene-depleted mice. These findings were either not observed or not explicitly described in other published Rag2 KO transcriptome analyses. In conclusion, we have provided an indication of miRNA-dependent regulations of clinical and pathological conditions in cardiac, renal, hepatic, nervous, and hematopoietic systems in Rag2 KO mice. These results may significantly contribute to the prediction of clinical disease caused by Rag2 deficiency.

Hematopoietic stem cell-specific GFP-expressing transgenic mice generated by genetic excision of a pan-hematopoietic reporter gene.

PubMed

Perez-Cunningham, Jessica; Boyer, Scott W; Landon, Mark; Forsberg, E Camilla

2016-08-01

Selective labeling of specific cell types by expression of green fluorescent protein (GFP) within the hematopoietic system would have great utility in identifying, localizing, and tracking different cell populations in flow cytometry, microscopy, lineage tracing, and transplantation assays. In this report, we describe the generation and characterization of a new transgenic mouse line with specific GFP labeling of all nucleated hematopoietic cells and platelets. This new "Vav-GFP" mouse line labels the vast majority of hematopoietic cells with GFP during both embryonic development and adulthood, with particularly high expression in hematopoietic stem and progenitor cells (HSPCs). With the exception of transient labeling of fetal endothelial cells, GFP expression is highly selective for hematopoietic cells and persists in donor-derived progeny after transplantation of HSPCs. Finally, we also demonstrate that the loxP-flanked reporter allows for specific GFP labeling of different hematopoietic cell subsets when crossed to various Cre reporter lines. By crossing Vav-GFP mice to Flk2-Cre mice, we obtained robust and highly selective GFP expression in hematopoietic stem cells (HSCs). These data describe a new mouse model capable of directing GFP labeling exclusively of hematopoietic cells or exclusively of HSCs. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Transcriptional diversity during lineage commitment of human blood progenitors.

PubMed

Chen, Lu; Kostadima, Myrto; Martens, Joost H A; Canu, Giovanni; Garcia, Sara P; Turro, Ernest; Downes, Kate; Macaulay, Iain C; Bielczyk-Maczynska, Ewa; Coe, Sophia; Farrow, Samantha; Poudel, Pawan; Burden, Frances; Jansen, Sjoert B G; Astle, William J; Attwood, Antony; Bariana, Tadbir; de Bono, Bernard; Breschi, Alessandra; Chambers, John C; Consortium, Bridge; Choudry, Fizzah A; Clarke, Laura; Coupland, Paul; van der Ent, Martijn; Erber, Wendy N; Jansen, Joop H; Favier, Rémi; Fenech, Matthew E; Foad, Nicola; Freson, Kathleen; van Geet, Chris; Gomez, Keith; Guigo, Roderic; Hampshire, Daniel; Kelly, Anne M; Kerstens, Hindrik H D; Kooner, Jaspal S; Laffan, Michael; Lentaigne, Claire; Labalette, Charlotte; Martin, Tiphaine; Meacham, Stuart; Mumford, Andrew; Nürnberg, Sylvia; Palumbo, Emilio; van der Reijden, Bert A; Richardson, David; Sammut, Stephen J; Slodkowicz, Greg; Tamuri, Asif U; Vasquez, Louella; Voss, Katrin; Watt, Stephen; Westbury, Sarah; Flicek, Paul; Loos, Remco; Goldman, Nick; Bertone, Paul; Read, Randy J; Richardson, Sylvia; Cvejic, Ana; Soranzo, Nicole; Ouwehand, Willem H; Stunnenberg, Hendrik G; Frontini, Mattia; Rendon, Augusto

2014-09-26

Blood cells derive from hematopoietic stem cells through stepwise fating events. To characterize gene expression programs driving lineage choice, we sequenced RNA from eight primary human hematopoietic progenitor populations representing the major myeloid commitment stages and the main lymphoid stage. We identified extensive cell type-specific expression changes: 6711 genes and 10,724 transcripts, enriched in non-protein-coding elements at early stages of differentiation. In addition, we found 7881 novel splice junctions and 2301 differentially used alternative splicing events, enriched in genes involved in regulatory processes. We demonstrated experimentally cell-specific isoform usage, identifying nuclear factor I/B (NFIB) as a regulator of megakaryocyte maturation-the platelet precursor. Our data highlight the complexity of fating events in closely related progenitor populations, the understanding of which is essential for the advancement of transplantation and regenerative medicine. Copyright © 2014, American Association for the Advancement of Science.

The Cytokine Flt3-Ligand in Normal and Malignant Hematopoiesis.

PubMed

Tsapogas, Panagiotis; Mooney, Ciaran James; Brown, Geoffrey; Rolink, Antonius

2017-05-24

The cytokine Fms-like tyrosine kinase 3 ligand (FL) is an important regulator of hematopoiesis. Its receptor, Flt3, is expressed on myeloid, lymphoid and dendritic cell progenitors and is considered an important growth and differentiation factor for several hematopoietic lineages. Activating mutations of Flt3 are frequently found in acute myeloid leukemia (AML) patients and associated with a poor clinical prognosis. In the present review we provide an overview of our current knowledge on the role of FL in the generation of blood cell lineages. We examine recent studies on Flt3 expression by hematopoietic stem cells and its potential instructive action at early stages of hematopoiesis. In addition, we review current findings on the role of mutated FLT3 in leukemia and the development of FLT3 inhibitors for therapeutic use to treat AML. The importance of mouse models in elucidating the role of Flt3-ligand in normal and malignant hematopoiesis is discussed.

Interleukin-7 Availability Is Maintained by a Hematopoietic Cytokine Sink Comprising Innate Lymphoid Cells and T Cells.

PubMed

Martin, Christopher E; Spasova, Darina S; Frimpong-Boateng, Kwesi; Kim, Hee-Ok; Lee, Minji; Kim, Kwang Soon; Surh, Charles D

2017-07-18

Interleukin-7 (IL-7) availability determines the size and proliferative state of the resting T cell pool. However, the mechanisms that regulate steady-state IL-7 amounts are unclear. Using experimental lymphopenic mouse models and IL-7-induced homeostatic proliferation to measure IL-7 availability in vivo, we found that radioresistant cells were the source of IL-7 for both CD4 + and CD8 + T cells. Hematopoietic lineage cells, although irrelevant as a source of IL-7, were primarily responsible for limiting IL-7 availability via their expression of IL-7R. Unexpectedly, innate lymphoid cells were found to have a potent influence on IL-7 amounts in the primary and secondary lymphoid tissues. These results demonstrate that IL-7 homeostasis is achieved through consumption by multiple subsets of innate and adaptive immune cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Cellular therapies supplement: strategies for improving transplant efficiency in the context of cellular therapeutics.

PubMed

Jimenez, Antonio; Fung, Henry C; Christopherson, Kent W

2011-11-01

The field of hematopoietic stem cell transplantation (HSCT) has overcome many obstacles that have led to our current clinical ability to utilize cells collected from marrow, mobilized peripheral blood, or umbilical cord blood for the treatment of malignant and nonmalignant hematologic diseases. It is in this context that it becomes evident that future progress will lie in our development of an understanding of the biology by which the process of HSCT is regulated. By understanding the cellular components and the mechanisms by which HSCT is either enhanced or suppressed it will then be possible to design therapeutic strategies to improve rates of engraftment that will have a positive impact on immune reconstitution post-HSCT. In this review we focus primarily on allogeneic hematopoietic stem cell transplantation (allo-HSCT), the current challenges associated with allo-HSCT, and some developing strategies to improve engraftment in this setting. © 2011 American Association of Blood Banks.

Complex regulation of HSC emergence by the Notch signaling pathway

PubMed Central

Butko, Emerald; Pouget, Claire; Traver, David

2016-01-01

Hematopoietic stem cells are formed during embryonic development, and serve as the foundation of the definitive blood program for life. Notch signaling has been well established as an essential direct contributor to HSC specification. However, several recent studies have indicated that the contribution of Notch signaling is complex. HSC specification requires multiple Notch signaling inputs, some received directly by hematopoietic precursors, and others that occur indirectly within neighboring somites. Of note, proinflammatory signals provided by primitive myeloid cells are needed for HSC specification via upregulation of the Notch pathway in hemogenic endothelium. In addition to multiple requirements for Notch activation, recent studies indicate that Notch signaling must subsequently be repressed to permit HSC emergence. Finally, Notch must then be reactivated to maintain HSC fate. In this review, we discuss the growing understanding of the dynamic contributions of Notch signaling to the establishment of hematopoiesis during development. PMID:26586199

Dexamethasone facilitates erythropoiesis in murine embryonic stem cells differentiating into hematopoietic cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, Anand S.; Kaushal, Sharmeela; Mishra, Rangnath

2006-07-28

Differentiating embryonic stem (ES) cells are increasingly emerging as an important source of hematopoietic progenitors with a potential to be useful for both basic and clinical research applications. It has been suggested that dexamethasone facilitates differentiation of ES cells towards erythrocytes but the mechanism responsible for sequential expression of genes regulating this process are not well-understood. Therefore, we in vitro induced differentiation of murine ES cells towards erythropoiesis and studied the sequential expression of a set of genes during the process. We hypothesized that dexamethasone-activates its cognate nuclear receptors inducing up-regulation of erythropoietic genes such as GATA-1, Flk-1, Epo-R, andmore » direct ES cells towards erythropoietic differentiation. ES cells were cultured in primary hematopoietic differentiation media containing methyl-cellulose, IMDM, IL-3, IL-6, and SCF to promote embryoid body (EB) formation. Total RNA of day 3, 5, and 9-old EBs was isolated for gene expression studies using RT-PCR. Cells from day 9 EBs were subjected to secondary differentiation using three different cytokines and growth factors combinations: (1) SCF, EPO, dexamethasone, and IGF; (2) SCF, IL-3, IL-6, and TPO; and (3) SCF IL-3, IL-6, TPO, and EPO. Total RNA from day 12 of secondary differentiated ES cells was isolated to study the gene expression pattern during this process. Our results demonstrate an up-regulation of GATA-1, Flk-1, HoxB-4, Epo-R, and globin genes ({alpha}-globin, {beta}H-1 globin, {beta}-major globin, {epsilon} -globin, and {zeta}-globin) in the 9-day-old EBs, whereas, RNA from 5-day-old EBs showed expression of HoxB-4, {epsilon}-globin, {gamma}-globin, {beta}H1-globin, and Flk-1. Three-day-old EBs showed only HoxB-4 and Flk-1 gene expression and lacked expression of all globin genes. These findings indicate that erythropoiesis-specific genes are activated later in the course of differentiation. Gene expression studies on the ES cells of secondary EB origin cultured in media containing dexamethasone showed a down-regulation of GATA-3 and an up-regulation of GATA-1, Flk-1, and Epo-R in comparison to the two other cytokines and growth factor combinations containing media. The secondary differentiation also showed an enhanced production of erythrocytic precursors in dexamethasone containing media in comparison to that in the control media. Our results indicate that dexamethasone can prove to be an effective agent which can be employed to enhance differentiation towards erythrocytic progenitors from ES cells.« less

Umbilical Cord Blood Transplantation Supported by Third Party Donor Cells: Rationale, Results and Applications

PubMed Central

van Besien, Koen; Liu, Hongtao; Jain, Nitin; Stock, Wendy; Artz, Andrew

2012-01-01

Low incidence of GVHD provides the major rational for pursuing UCB stem cell transplant (UCB SCT). Considerable evidence also suggests a lower rate of recurrence after UCB SCT than after transplantation from adult donors. Recent advances in understanding of the human fetal immune development provide a rational underpinning for these clinical outcomes. The fetal immune system is geared toward maintaining tolerance to foreign antigens, particularly to the maternal antigens to which it is exposed throughout gestation. To this purpose it is dominated by a unique population of peripheral T regulatory cells which actively maintain tolerance. This and other features of the UCB lymphoid system explains the low incidence of GVHD and superior outcomes of UCB SCT with NIMA (non-inherited maternal antigens)-matched grafts. At the same time, highly sensitized maternal microchimeric cells are frequently detected in UCB and likely contribute to superior GVL effects and low rates of disease recurrence in IPA (inherited paternal antigen) matched UCB recipients. But historically erratic and slow hematopoietic recovery after UCB SCT leads to increased early morbidity and mortality, excessive hospitalization and costs. This has held up the widespread utilization of UCB SCT in adults. Here we summarize recent data on UCB SCT with an emphasis on studies of co-infusion of adult CD34 selected hematopoietic stem cells with UCB SCT. This procedure, through transient engraftment of adult hematopoietic stem cells largely overcomes the problem of delayed engraftment. We also briefly discuss unresolved issues and possible future applications of this technology. PMID:23142329

Neurotrophins promote revascularization by local recruitment of TrkB+ endothelial cells and systemic mobilization of hematopoietic progenitors

PubMed Central

Kermani, Pouneh; Rafii, Dahlia; Jin, David K.; Whitlock, Paul; Schaffer, Wendy; Chiang, Anne; Vincent, Loic; Friedrich, Matthias; Shido, Koji; Hackett, Neil R.; Crystal, Ronald G.; Rafii, Shahin; Hempstead, Barbara L.

2005-01-01

The neurotrophin brain-derived neurotrophic factor (BDNF) is required for the maintenance of cardiac vessel wall stability during embryonic development through direct angiogenic actions on endothelial cells expressing the tropomysin receptor kinase B (TrkB). However, the role of BDNF and a related neurotrophin ligand, neurotrophin-4 (NT-4), in the regulation of revascularization of the adult tissues is unknown. To study the potential angiogenic capacity of BDNF in mediating the neovascularization of ischemic and non-ischemic adult mouse tissues, we utilized a hindlimb ischemia and a subcutaneous Matrigel model. Recruitment of endothelial cells and promotion of channel formation within the Matrigel plug by BDNF and NT-4 was comparable to that induced by VEGF-A. The introduction of BDNF into non-ischemic ears or ischemic limbs induced neoangiogenesis, with a 2-fold increase in the capillary density. Remarkably, treatment with BDNF progressively increased blood flow in the ischemic limb over 21 days, similar to treatment with VEGF-A. The mechanism by which BDNF enhances capillary formation is mediated in part through local activation of the TrkB receptor and also by recruitment of Sca-1+CD11b+ pro-angiogenic hematopoietic cells. BDNF induces a potent direct chemokinetic action on subsets of marrow-derived Sca-1+ hematopoietic cells co-expressing TrkB. These studies suggest that local regional delivery of BDNF may provide a novel mechanism for inducing neoangiogenesis through both direct actions on local TrkB-expressing endothelial cells in skeletal muscle and recruitment of specific subsets of TrkB+ bone marrow–derived hematopoietic cells to provide peri-endothelial support for the newly formed vessels. PMID:15765148

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libregts, Sten F.W.M.; Nolte, Martijn A., E-mail: m.nolte@sanquin.nl

Quiescence, self-renewal, lineage commitment and differentiation of hematopoietic stem cells (HSCs) towards fully mature blood cells are a complex process that involves both intrinsic and extrinsic signals. During steady-state conditions, most hematopoietic signals are provided by various resident cells inside the bone marrow (BM), which establish the HSC micro-environment. However, upon infection, the hematopoietic process is also affected by pathogens and activated immune cells, which illustrates an effective feedback mechanism to hematopoietic stem and progenitor cells (HSPCs) via immune-mediated signals. Here, we review the impact of pathogen-associated molecular patterns (PAMPs), damage-associated molecular patterns (DAMPs), costimulatory molecules and pro-inflammatory cytokines onmore » the quiescence, proliferation and differentiation of HSCs and more committed progenitors. As modulation of HSPC function via these immune-mediated signals holds an interesting parallel with the “three-signal-model” described for the activation and differentiation of naïve T-cells, we propose a novel “three-signal” concept for immune-driven hematopoiesis. In this model, the recognition of PAMPs and DAMPs will activate HSCs and induce proliferation, while costimulatory molecules and pro-inflammatory cytokines confer a second and third signal, respectively, which further regulate expansion, lineage commitment and differentiation of HSPCs. We review the impact of inflammatory stress on hematopoiesis along these three signals and we discuss whether they act independently from each other or that concurrence of these signals is important for an adequate response of HSPCs upon infection. - Highlights: • Inflammation and infection have a direct impact on hematopoiesis in the bone marrow. • We draw a striking parallel between immune-driven hematopoiesis and T cell activation. • We review how PAMPs and DAMPs, costimulation and cytokines influence HSPC function.« less

MicroRNA-125 family members exert a similar role in the regulation of murine hematopoiesis.

PubMed

Wojtowicz, Edyta E; Walasek, Marta A; Broekhuis, Mathilde J C; Weersing, Ellen; Ritsema, Martha; Ausema, Albertina; Bystrykh, Leonid V; de Haan, Gerald

2014-10-01

MicroRNAs (miRNAs) are crucial for proper functioning of hematopoietic stem and progenitor cells (HSPCs). Members of the miRNA-125 family (consisting of miR-125a, miR-125b1, and miR-125b2) are known to confer a proliferative advantage on cells upon overexpression, to decrease the rate of apoptosis by targeting proapoptotic genes, and to promote differentiation toward the myeloid lineage in mice. However, many distinct biological effects of the three miR-125 species have been reported as well. In the current study, we set out to assess whether the three miRNA-125s that carry identical seed sequences could be functionally different. Our data show that overexpression of each of the three miR-125 family members preserves HSPCs in a primitive state in vitro, results in a competitive advantage upon serial transplantation, and promotes skewing toward the myeloid lineage. All miR-125 family members decreased the pool of phenotypically defined Lin(-)Sca(+)Kit(+)CD48(-)CD150(+) long-term hematopoietic stem cells, simultaneously increasing the self-renewal activity upon secondary transplantation. The downregulation of miR-125s in hematopoietic stem cells abolishes these effects and impairs long-term contribution to blood cell production. The introduction of a point mutation within the miRNA-125 seed sequence abolishes all abovementioned effects and leads to the restoration of normal hematopoiesis. Our results show that all miR-125 family members are similar in function, they likely operate in a seed-sequence-dependent manner, and they induce a highly comparable hematopoietic phenotype. Copyright © 2014 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Transcription regulation by distal enhancers: who's in the loop?

PubMed

Stadhouders, Ralph; van den Heuvel, Anita; Kolovos, Petros; Jorna, Ruud; Leslie, Kris; Grosveld, Frank; Soler, Eric

2012-01-01

Genome-wide chromatin profiling efforts have shown that enhancers are often located at large distances from gene promoters within the noncoding genome. Whereas enhancers can stimulate transcription initiation by communicating with promoters via chromatin looping mechanisms, we propose that enhancers may also stimulate transcription elongation by physical interactions with intronic elements. We review here recent findings derived from the study of the hematopoietic system.

Development of hematopoietic stem and progenitor cells from human pluripotent stem cells.

PubMed

Chen, Tong; Wang, Fen; Wu, Mengyao; Wang, Zack Z

2015-07-01

Human pluripotent stem cells (hPSCs), including human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), provide a new cell source for regenerative medicine, disease modeling, drug discovery, and preclinical toxicity screening. Understanding of the onset and the sequential process of hematopoietic cells from differentiated hPSCs will enable the achievement of personalized medicine and provide an in vitro platform for studying of human hematopoietic development and disease. During embryogenesis, hemogenic endothelial cells, a specified subset of endothelial cells in embryonic endothelium, are the primary source of multipotent hematopoietic stem cells. In this review, we discuss current status in the generation of multipotent hematopoietic stem and progenitor cells from hPSCs via hemogenic endothelial cells. We also review the achievements in direct reprogramming from non-hematopoietic cells to hematopoietic stem and progenitor cells. Further characterization of hematopoietic differentiation in hPSCs will improve our understanding of blood development and expedite the development of hPSC-derived blood products for therapeutic purpose. © 2015 Wiley Periodicals, Inc.

Altered Hematopoiesis in Mice Lacking DNA Polymerase μ Is Due to Inefficient Double-Strand Break Repair

PubMed Central

Lucas, Daniel; Escudero, Beatriz; Ligos, José Manuel; Segovia, Jose Carlos; Estrada, Juan Camilo; Terrados, Gloria; Blanco, Luis; Samper, Enrique; Bernad, Antonio

2009-01-01

Polymerase mu (Polμ) is an error-prone, DNA-directed DNA polymerase that participates in non-homologous end-joining (NHEJ) repair. In vivo, Polμ deficiency results in impaired Vκ-Jκ recombination and altered somatic hypermutation and centroblast development. In Polμ−/− mice, hematopoietic development was defective in several peripheral and bone marrow (BM) cell populations, with about a 40% decrease in BM cell number that affected several hematopoietic lineages. Hematopoietic progenitors were reduced both in number and in expansion potential. The observed phenotype correlates with a reduced efficiency in DNA double-strand break (DSB) repair in hematopoietic tissue. Whole-body γ-irradiation revealed that Polμ also plays a role in DSB repair in non-hematopoietic tissues. Our results show that Polμ function is required for physiological hematopoietic development with an important role in maintaining early progenitor cell homeostasis and genetic stability in hematopoietic and non-hematopoietic tissues. PMID:19229323

Loss of quiescence and self-renewal capacity of hematopoietic stem cell in an in vitro leukemic niche.

PubMed

Vanegas, Natalia-Del Pilar; Vernot, Jean-Paul

2017-01-01

Leukemic and mesenchymal stem cells interact in the leukemic microenvironment and affect each other differently. This interplay has also important implications for the hematopoietic stem cell (HSC) biology and function. This study evaluated human HSC self-renewal potential and quiescence in an in vitro leukemic niche without leukemic cells. A leukemic niche was established by co-culturing mesenchymal stem cells with a fresh conditioned medium obtained from a leukemic (REH) cell line. After 3 days, the REH-conditioned medium was removed and freshly isolated CD34+ at a density of up to 100,000 cells/ml were added to the leukemic niche. CD34+ cell evaluations (cell cycle, self-renewal gene expression and migration capacity) were performed after 3 further days of co-culture. Additionally, we preliminary investigated the soluble factors present in the leukemic niche and their effect on the mesenchymal stem cells. Statistical significance was assessed by Student's t test or the nonparametric test Kolmogorov-Smirnov. By co-culturing normal mesenchymal stem cells with the REH-conditioned medium we showed that hematopoietic stem cells, normally in a quiescent state, enter cell cycle and proliferate. This loss of quiescence was accompanied by an increased expression of Ki-67 and c-Myc, two well-known cell proliferation-associated markers. Two central regulators of quiescence GATA2 and p53 were also down regulated. Importantly, two genes involved in HSC self-renewal, Klf4 and the histone-lysine N -methyltransferase enzyme Ezh2, were severely affected. On the contrary, c-Kit expression, the stem cell factor receptor, was upregulated in hematopoietic stem cells when compared to the normal niche. Interestingly, mesenchymal stem cells incubated with the REH-conditioned medium stopped growing, showed a flattened morphology with the appearance of small vacuoles, and importantly, became positive for the senescence-associated beta-galactosidase activity. Evaluation of the leukemic-conditioned medium showed increased IL-6 and IL-8, suggesting that these cytokines could be responsible for the observed changes. Our results showed that quiescence and self-renewal are severely affected in this leukemic niche. This in vitro leukemic niche, established without leukemic cells, will facilitate HSC gene expression evaluation and the development of therapeutic agents aimed to neutralize soluble factors and the cell signaling pathways involved in HSC alterations.

PUMILIO/FOXP1 signaling drives expansion of hematopoietic stem/progenitor and leukemia cells

PubMed Central

Naudin, Cécile; Hattabi, Aurore; Michelet, Fabio; Miri-Nezhad, Ayda; Benyoucef, Aissa; Pflumio, Françoise; Guillonneau, François; Fichelson, Serge; Vigon, Isabelle; Dusanter-Fourt, Isabelle

2017-01-01

RNA-binding proteins (RBPs) have emerged as important regulators of invertebrate adult stem cells, but their activities remain poorly appreciated in mammals. Using a short hairpin RNA strategy, we demonstrate here that the 2 mammalian RBPs, PUMILIO (PUM)1 and PUM2, members of the PUF family of posttranscriptional regulators, are essential for hematopoietic stem/progenitor cell (HSPC) proliferation and survival in vitro and in vivo upon reconstitution assays. Moreover, we found that PUM1/2 sustain myeloid leukemic cell growth. Through a proteomic approach, we identified the FOXP1 transcription factor as a new target of PUM1/2. Contrary to its canonical repressive activity, PUM1/2 rather promote FOXP1 expression by a direct binding to 2 canonical PUM responsive elements present in the FOXP1-3′ untranslated region (UTR). Expression of FOXP1 strongly correlates with PUM1 and PUM2 levels in primary HSPCs and myeloid leukemia cells. We demonstrate that FOXP1 by itself supports HSPC and leukemic cell growth, thus mimicking PUM activities. Mechanistically, FOXP1 represses the expression of the p21−CIP1 and p27−KIP1 cell cycle inhibitors. Enforced FOXP1 expression reverses shPUM antiproliferative and proapoptotic activities. Altogether, our results reveal a novel regulatory pathway, underscoring a previously unknown and interconnected key role of PUM1/2 and FOXP1 in regulating normal HSPC and leukemic cell growth. PMID:28232582

MAVS Expressed by Hematopoietic Cells Is Critical for Control of West Nile Virus Infection and Pathogenesis.

PubMed

Zhao, Jincun; Vijay, Rahul; Zhao, Jingxian; Gale, Michael; Diamond, Michael S; Perlman, Stanley

2016-08-15

West Nile virus (WNV) is the most important cause of epidemic encephalitis in North America. Innate immune responses, which are critical for control of WNV infection, are initiated by signaling through pathogen recognition receptors, RIG-I and MDA5, and their downstream adaptor molecule, MAVS. Here, we show that a deficiency of MAVS in hematopoietic cells resulted in increased mortality and delayed WNV clearance from the brain. In Mavs(-/-) mice, a dysregulated immune response was detected, characterized by a massive influx of macrophages and virus-specific T cells into the infected brain. These T cells were polyfunctional and lysed peptide-pulsed target cells in vitro However, virus-specific T cells in the brains of infected Mavs(-/-) mice exhibited lower functional avidity than those in wild-type animals, and even virus-specific memory T cells generated by prior immunization could not protect Mavs(-/-) mice from WNV-induced lethal disease. Concomitant with ineffective virus clearance, macrophage numbers were increased in the Mavs(-/-) brain, and both macrophages and microglia exhibited an activated phenotype. Microarray analyses of leukocytes in the infected Mavs(-/-) brain showed a preferential expression of genes associated with activation and inflammation. Together, these results demonstrate a critical role for MAVS in hematopoietic cells in augmenting the kinetics of WNV clearance and thereby preventing a dysregulated and pathogenic immune response. West Nile virus (WNV) is the most important cause of mosquito-transmitted encephalitis in the United States. The innate immune response is known to be critical for protection in infected mice. Here, we show that expression of MAVS, a key adaptor molecule in the RIG-I-like receptor RNA-sensing pathway, in hematopoietic cells is critical for protection from lethal WNV infection. In the absence of MAVS, there is a massive infiltration of myeloid cells and virus-specific T cells into the brain and overexuberant production of proinflammatory cytokines. These results demonstrate the important role that MAVS expression in hematopoietic cells has in regulating the inflammatory response in the WNV-infected brain. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Rhabdomyosarcoma presenting as acute leukemia.

PubMed

Morandi, S; Manna, A; Sabattini, E; Porcellini, A

1996-08-01

We describe a case of a very unusual presentation of rhabdomyosarcoma. An 18-year-old woman presented with symptoms and signs compatible with acute leukemia. The bone marrow picture showed diffuse involvement sustained by undifferentiated blasts that turned out to be of striated muscle origin by immunochemistry. While it is well known that rhabdomyosarcoma may metastasize to the bone marrow, extensive marrow involvement with leukemic spread as a unique clinical manifestation is extremely rare. Our observation further confirms the need to consider rhabdomyosarcoma among the possible differential diagnoses in patients who present with a leukemic picture and atypical blasts lacking all hematopoietic markers.

Hematopoietic Stem Cell Transplantation in Primary Immunodeficiency Patients in the Black Sea Region of Turkey.

PubMed

Yıldıran, Alişan; Çeliksoy, Mehmet Halil; Borte, Stephan; Güner, Şükrü Nail; Elli, Murat; Fışgın, Tunç; Özyürek, Emel; Sancak, Recep; Oğur, Gönül

2017-12-01

Hematopoietic stem cell transplantation is a promising curative therapy for many combined primary immunodeficiencies and phagocytic disorders. We retrospectively reviewed pediatric cases of patients diagnosed with primary immunodeficiencies and scheduled for hematopoietic stem cell transplantation. We identified 22 patients (median age, 6 months; age range, 1 month to 10 years) with various diagnoses who received hematopoietic stem cell transplantation. The patient diagnoses included severe combined immunodeficiency (n=11), Chediak-Higashi syndrome (n=2), leukocyte adhesion deficiency (n=2), MHC class 2 deficiency (n=2), chronic granulomatous syndrome (n=2), hemophagocytic lymphohistiocytosis (n=1), Wiskott-Aldrich syndrome (n=1), and Omenn syndrome (n=1). Of the 22 patients, 7 received human leukocyte antigen-matched related hematopoietic stem cell transplantation, 12 received haploidentical hematopoietic stem cell transplantation, and 2 received matched unrelated hematopoietic stem cell transplantation. The results showed that 5 patients had graft failure. Fourteen patients survived, yielding an overall survival rate of 67%. Screening newborn infants for primary immunodeficiency diseases may result in timely administration of hematopoietic stem cell transplantation.

Brief report: ectopic expression of NUP98-HOXA10 augments erythroid differentiation of human embryonic stem cells.

PubMed

Ji, Junfeng; Risueño, Ruth M; Hong, Seokho; Allan, David; Rosten, Patty; Humphries, Keith; Bhatia, Mickie

2011-04-01

Hox genes encode highly conserved transcription factors that have been implicated in hematopoietic development and self-renewal of hematopoietic stem cells (HSCs) and hematopoietic development. The potency of NUP98-HOXA10hd (NA10) on adult murine bone marrow HSC self-renewal prompted us to examine its effect on specification and proliferation of hematopoietic cells derived from human embryonic stem cells (hESCs). Here, we demonstrate that expression of NA10 in hESCs influences the hematopoietic differentiation program. The specific effect of NA10 is dependent on the developmental stage of hematopoietic emergence from hESCs. Overexpression of NA10 in either undifferentiated hESCs or early hemogenic precursors augmented the frequency of CD45(-) GlycophorinA(+) cells and erythroid progenitors (blast-forming unit-erythrocyte). In contrast, targeted NA10 expression in primitive CD34+ cells committed to the hematopoietic lineage had no effect on erythropoietic capacity but instead increased hematopoietic progenitor proliferation. Our study reveals a novel neomorphic effect of NA10 in early human erythroid development from pluripotent stem cells. Copyright © 2011 AlphaMed Press.

Distinct Brca1 Mutations Differentially Reduce Hematopoietic Stem Cell Function.

PubMed

Mgbemena, Victoria E; Signer, Robert A J; Wijayatunge, Ranjula; Laxson, Travis; Morrison, Sean J; Ross, Theodora S

2017-01-24

BRCA1 is a well-known DNA repair pathway component and a tissue-specific tumor suppressor. However, its role in hematopoiesis is uncertain. Here, we report that a cohort of patients heterozygous for BRCA1 mutations experienced more hematopoietic toxicity from chemotherapy than those with BRCA2 mutations. To test whether this reflects a requirement for BRCA1 in hematopoiesis, we generated mice with Brca1 mutations in hematopoietic cells. Mice homozygous for a null Brca1 mutation in the embryonic hematopoietic system (Vav1-iCre;Brca1 F22-24/F22-24 ) developed hematopoietic defects in early adulthood that included reduced hematopoietic stem cells (HSCs). Although mice homozygous for a huBRCA1 knockin allele (Brca1 BRCA1/BRCA1 ) were normal, mice with a mutant huBRCA1/5382insC allele and a null allele (Mx1-Cre;Brca1 F22-24/5382insC ) had severe hematopoietic defects marked by a complete loss of hematopoietic stem and progenitor cells. Our data show that Brca1 is necessary for HSC maintenance and normal hematopoiesis and that distinct mutations lead to different degrees of hematopoietic dysfunction. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Hematopoietic stem cell loss and hematopoietic failure in severe aplastic anemia is driven by macrophages and aberrant podoplanin expression.

PubMed

McCabe, Amanda; Smith, Julianne N P; Costello, Angelica; Maloney, Jackson; Katikaneni, Divya; MacNamara, Katherine C

2018-05-17

Severe aplastic anemia results from profound hematopoietic stem cell loss. T cells and interferon gamma have long been associated with severe aplastic anemia, yet the underlying mechanisms driving hematopoietic stem cell loss remain unknown. Using a mouse model of severe aplastic anemia, we demonstrate that interferon gamma-dependent hematopoietic stem cell loss required macrophages. Interferon gamma was necessary for bone marrow macrophage persistence, despite loss of other myeloid cells and hematopoietic stem cells. Depleting macrophages or abrogating interferon gamma signaling specifically in macrophages did not impair T cell activation or interferon gamma production in the bone marrow but rescued hematopoietic stem cells and reduced mortality. Thus, macrophages are not required for induction of interferon gamma in severe aplastic anemia and rather act as sensors of interferon gamma. Macrophage depletion rescued thrombocytopenia, increased bone marrow megakaryocytes, preserved platelet-primed stem cells, and increased the platelet-repopulating capacity of transplanted hematopoietic stem cells. In addition to the hematopoietic effects, severe aplastic anemia induced loss of non-hematopoietic stromal populations, including podoplanin-positive stromal cells. However, a subset of podoplanin-positive macrophages was increased during disease, and blockade of podoplanin in mice was sufficient to rescue disease. Our data further our understanding of disease pathogenesis demonstrating a novel role for macrophages as sensors of interferon gamma, thus illustrating an important role for the microenvironment in pathogenesis of severe aplastic anemia. Copyright © 2018, Ferrata Storti Foundation.

Epigenetic Therapy of Hematopoietic Malignancies: Novel Approaches for Tissue-Specific and Global Inhibition of EZH2 Enzymatic Activities

DTIC Science & Technology

2015-08-01

such as myelodysplastic syndromes (MDSs), primary myelofibrosis (PMF), myeloproliferative neoplasms (MPNs), and chronic myelomonocytic leukemia (CMML...Inactivation of polycomb repressive complex 2 components in myeloproliferative and myelo- dysplastic/ myeloproliferative neoplasms . Blood. 2012;119:1208...and emerges as regulator of myeloid neoplasms .19,20 Inhibitors selective to EZH2 have recently been developed and shown to be effective in killing

Challenges and Opportunities to Harnessing the (Hematopoietic) Stem Cell Niche

PubMed Central

Choi, Ji Sun; Harley, Brendan A. C.

2016-01-01

In our body, stem cells reside in a microenvironment termed the niche. While the exact composition and therefore the level of complexity of a stem cell niche can vary significantly tissue-to-tissue, the stem cell niche microenvironment is dynamic, typically containing spatial and temporal variations in both cellular, extracellular matrix, and biomolecular components. This complex flow of secreted or bound biomolecules, cytokines, extracellular matrix components, and cellular constituents all contribute to the regulation of stem cell fate specification events, making engineering approaches at the nano- and micro-scale of particular interest for creating an artificial niche environment in vitro. Recent advances in fabrication approaches have enabled biomedical researchers to capture and recreate the complexity of stem cell niche microenvironments in vitro. Such engineered platforms show promise as a means to enhance our understanding of the mechanisms underlying niche-mediated stem cell regulation as well as offer opportunities to precisely control stem cell expansion and differentiation events for clinical applications. While these principles generally apply to all adult stem cells and niches, in this review, we focus on recent developments in engineering synthetic niche microenvironments for one of the best-characterized stem cell populations, hematopoietic stem cells (HSC). Specifically, we highlight recent advances in platforms designed to facilitate the extrinsic control of HSC fate decisions. PMID:27134819

Tumor necrosis factor-alpha inhibits stem cell factor-induced proliferation of human bone marrow progenitor cells in vitro. Role of p55 and p75 tumor necrosis factor receptors.

PubMed Central

Rusten, L S; Smeland, E B; Jacobsen, F W; Lien, E; Lesslauer, W; Loetscher, H; Dubois, C M; Jacobsen, S E

1994-01-01

Stem cell factor (SCF), a key regulator of hematopoiesis, potently synergizes with a number of hematopoietic growth factors. However, little is known about growth factors capable of inhibiting the actions of SCF. TNF-alpha has been shown to act as a bidirectional regulator of myeloid cell proliferation and differentiation. This study was designed to examine interactions between TNF-alpha and SCF. Here, we demonstrate that TNF-alpha potently and directly inhibits SCF-stimulated proliferation of CD34+ hematopoietic progenitor cells. Furthermore, TNF-alpha blocked all colony formation stimulated by SCF in combination with granulocyte colony-stimulating factor (CSF) or CSF-1. The synergistic effect of SCF observed in combination with GM-CSF or IL-3 was also inhibited by TNF-alpha, resulting in colony numbers similar to those obtained in the absence of SCF. These effects of TNF-alpha were mediated through the p55 TNF receptor, whereas little or no inhibition was signaled through the p75 TNF receptor. Finally, TNF-alpha downregulated c-kit cell-surface expression on CD34+ bone marrow cells, and this was predominantly a p55 TNF receptor-mediated event as well. Images PMID:7518828

Airway structural cells regulate TLR5-mediated mucosal adjuvant activity.

PubMed

Van Maele, L; Fougeron, D; Janot, L; Didierlaurent, A; Cayet, D; Tabareau, J; Rumbo, M; Corvo-Chamaillard, S; Boulenouar, S; Jeffs, S; Vande Walle, L; Lamkanfi, M; Lemoine, Y; Erard, F; Hot, D; Hussell, T; Ryffel, B; Benecke, A G; Sirard, J-C

2014-05-01

Antigen-presenting cell (APC) activation is enhanced by vaccine adjuvants. Most vaccines are based on the assumption that adjuvant activity of Toll-like receptor (TLR) agonists depends on direct, functional activation of APCs. Here, we sought to establish whether TLR stimulation in non-hematopoietic cells contributes to flagellin's mucosal adjuvant activity. Nasal administration of flagellin enhanced T-cell-mediated immunity, and systemic and secretory antibody responses to coadministered antigens in a TLR5-dependent manner. Mucosal adjuvant activity was not affected by either abrogation of TLR5 signaling in hematopoietic cells or the presence of flagellin-specific, circulating neutralizing antibodies. We found that flagellin is rapidly degraded in conducting airways, does not translocate into lung parenchyma and stimulates an early immune response, suggesting that TLR5 signaling is regionalized. The flagellin-specific early response of lung was regulated by radioresistant cells expressing TLR5 (particularly the airway epithelial cells). Flagellin stimulated the epithelial production of a small set of mediators that included the chemokine CCL20, which is known to promote APC recruitment in mucosal tissues. Our data suggest that (i) the adjuvant activity of TLR agonists in mucosal vaccination may require TLR stimulation of structural cells and (ii) harnessing the effect of adjuvants on epithelial cells can improve mucosal vaccines.

76 FR 39234 - Federal Acquisition Regulation; Unique Procurement Instrument Identifier

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-05

...-AL70 Federal Acquisition Regulation; Unique Procurement Instrument Identifier AGENCIES: Department of... Acquisition Regulation (FAR) to standardize use of unique Procurement Instrument Identifiers (PIID) throughout... Acquisition Council and the Defense Acquisition Regulations Council (the Councils) reviewed the public...

Role of the clathrin adaptor PICALM in normal hematopoiesis and polycythemia vera pathophysiology.

PubMed

Ishikawa, Yuichi; Maeda, Manami; Pasham, Mithun; Aguet, Francois; Tacheva-Grigorova, Silvia K; Masuda, Takeshi; Yi, Hai; Lee, Sung-Uk; Xu, Jian; Teruya-Feldstein, Julie; Ericsson, Maria; Mullally, Ann; Heuser, John; Kirchhausen, Tom; Maeda, Takahiro

2015-04-01

Clathrin-dependent endocytosis is an essential cellular process shared by all cell types. Despite this, precisely how endocytosis is regulated in a cell-type-specific manner and how this key pathway functions physiologically or pathophysiologically remain largely unknown. PICALM, which encodes the clathrin adaptor protein PICALM, was originally identified as a component of the CALM/AF10 leukemia oncogene. Here we show, by employing a series of conditional Picalm knockout mice, that PICALM critically regulates transferrin uptake in erythroid cells by functioning as a cell-type-specific regulator of transferrin receptor endocytosis. While transferrin receptor is essential for the development of all hematopoietic lineages, Picalm was dispensable for myeloid and B-lymphoid development. Furthermore, global Picalm inactivation in adult mice did not cause gross defects in mouse fitness, except for anemia and a coat color change. Freeze-etch electron microscopy of primary erythroblasts and live-cell imaging of murine embryonic fibroblasts revealed that Picalm function is required for efficient clathrin coat maturation. We showed that the PICALM PIP2 binding domain is necessary for transferrin receptor endocytosis in erythroblasts and absolutely essential for erythroid development from mouse hematopoietic stem/progenitor cells in an erythroid culture system. We further showed that Picalm deletion entirely abrogated the disease phenotype in a Jak2(V617F) knock-in murine model of polycythemia vera. Our findings provide new insights into the regulation of cell-type-specific transferrin receptor endocytosis in vivo. They also suggest a new strategy to block cellular uptake of transferrin-bound iron, with therapeutic potential for disorders characterized by inappropriate red blood cell production, such as polycythemia vera. Copyright© Ferrata Storti Foundation.

Adult hematopoietic stem cells lacking Hif-1α self-renew normally.

PubMed

Vukovic, Milica; Sepulveda, Catarina; Subramani, Chithra; Guitart, Amélie V; Mohr, Jasmine; Allen, Lewis; Panagopoulou, Theano I; Paris, Jasmin; Lawson, Hannah; Villacreces, Arnaud; Armesilla-Diaz, Alejandro; Gezer, Deniz; Holyoake, Tessa L; Ratcliffe, Peter J; Kranc, Kamil R

2016-06-09

The hematopoietic stem cell (HSC) pool is maintained under hypoxic conditions within the bone marrow microenvironment. Cellular responses to hypoxia are largely mediated by the hypoxia-inducible factors, Hif-1 and Hif-2. The oxygen-regulated α subunits of Hif-1 and Hif-2 (namely, Hif-1α and Hif-2α) form dimers with their stably expressed β subunits and control the transcription of downstream hypoxia-responsive genes to facilitate adaptation to low oxygen tension. An initial study concluded that Hif-1α is essential for HSC maintenance, whereby Hif-1α-deficient HSCs lost their ability to self-renew in serial transplantation assays. In another study, we demonstrated that Hif-2α is dispensable for cell-autonomous HSC maintenance, both under steady-state conditions and following transplantation. Given these unexpected findings, we set out to revisit the role of Hif-1α in cell-autonomous HSC functions. Here we demonstrate that inducible acute deletion of Hif-1α has no impact on HSC survival. Notably, unstressed HSCs lacking Hif-1α efficiently self-renew and sustain long-term multilineage hematopoiesis upon serial transplantation. Finally, Hif-1α-deficient HSCs recover normally after hematopoietic injury induced by serial administration of 5-fluorouracil. We therefore conclude that despite the hypoxic nature of the bone marrow microenvironment, Hif-1α is dispensable for cell-autonomous HSC maintenance. © 2016 by The American Society of Hematology.

Adult hematopoietic stem cells lacking Hif-1α self-renew normally

PubMed Central

Vukovic, Milica; Sepulveda, Catarina; Subramani, Chithra; Guitart, Amélie V.; Mohr, Jasmine; Allen, Lewis; Panagopoulou, Theano I.; Paris, Jasmin; Lawson, Hannah; Villacreces, Arnaud; Armesilla-Diaz, Alejandro; Gezer, Deniz; Holyoake, Tessa L.; Ratcliffe, Peter J.

2016-01-01

The hematopoietic stem cell (HSC) pool is maintained under hypoxic conditions within the bone marrow microenvironment. Cellular responses to hypoxia are largely mediated by the hypoxia-inducible factors, Hif-1 and Hif-2. The oxygen-regulated α subunits of Hif-1 and Hif-2 (namely, Hif-1α and Hif-2α) form dimers with their stably expressed β subunits and control the transcription of downstream hypoxia-responsive genes to facilitate adaptation to low oxygen tension. An initial study concluded that Hif-1α is essential for HSC maintenance, whereby Hif-1α–deficient HSCs lost their ability to self-renew in serial transplantation assays. In another study, we demonstrated that Hif-2α is dispensable for cell-autonomous HSC maintenance, both under steady-state conditions and following transplantation. Given these unexpected findings, we set out to revisit the role of Hif-1α in cell-autonomous HSC functions. Here we demonstrate that inducible acute deletion of Hif-1α has no impact on HSC survival. Notably, unstressed HSCs lacking Hif-1α efficiently self-renew and sustain long-term multilineage hematopoiesis upon serial transplantation. Finally, Hif-1α–deficient HSCs recover normally after hematopoietic injury induced by serial administration of 5-fluorouracil. We therefore conclude that despite the hypoxic nature of the bone marrow microenvironment, Hif-1α is dispensable for cell-autonomous HSC maintenance. PMID:27060169

Novel anti-c-Mpl monoclonal antibodies identified multiple differentially glycosylated human c-Mpl proteins in megakaryocytic cells but not in human solid tumors.

PubMed

Zhan, Jinghui; Felder, Barbara; Ellison, Aaron R; Winters, Aaron; Salimi-Moosavi, Hossein; Scully, Sheila; Turk, James R; Wei, Ping

2013-06-01

Thrombopoietin and its cognate receptor, c-Mpl, are the primary molecular regulators of megakaryocytopoiesis and platelet production. To date the pattern of c-Mpl expression in human solid tumors and the distribution and biochemical properties of c-Mpl proteins in hematopoietic tissues are largely unknown. We have recently developed highly specific mouse monoclonal antibodies (MAb) against human c-Mpl. In this study we used these antibodies to demonstrate the presence of full-length and truncated human c-Mpl proteins in various megakaryocytic cell types, and their absence in over 100 solid tumor cell lines and in the 12 most common primary human tumor types. Quantitative assays showed a cell context-dependent distribution of full-length and truncated c-Mpl proteins. All forms of human c-Mpl protein were found to be modified with extensive N-linked glycosylation but different degrees of sialylation and O-linked glycosylation. Of note, different variants of full-length c-Mpl protein exhibiting differential glycosylation were expressed in erythromegakaryocytic leukemic cell lines and in platelets from healthy human donors. This work provides a comprehensive analysis of human c-Mpl mRNA and protein expression on normal and malignant hematopoietic and non-hematopoietic cells and demonstrates the multiple applications of several novel anti-c-Mpl antibodies.

Single Targeted Exon Mutation Creates a True Congenic Mouse for Competitive Hematopoietic Stem Cell Transplantation: The C57BL/6-CD45.1(STEM) Mouse.

PubMed

Mercier, Francois E; Sykes, David B; Scadden, David T

2016-06-14

Defining the molecular regulators of hematopoietic stem and progenitor cells (HSPCs) requires in vivo functional analyses. Competitive bone marrow transplants (BMTs) compare control and test HSPCs to demonstrate the functional role of a genetic change or chemical perturbation. Competitive BMT is enabled by antibodies that specifically recognize hematopoietic cells from congenic mouse strains due to variants of the cell surface protein CD45, designated CD45.1 and CD45.2. The current congenic competitor strain, B6.SJL-Ptprc(a) Pepc(b)/BoyJ (CD45.1), has a substantial inherent disadvantage in competition against the C57BL/6 (CD45.2) strain, confounding experimental interpretation. Despite backcrossing, the congenic interval over which the B6.SJL-Ptprc(a) Pepc(b)/BoyJ strain differs is almost 40 Mb encoding ∼300 genes. Here, we demonstrate that a single amino acid change determines the CD45.1 epitope. Further, we report on the single targeted exon mutant (STEM) mouse strain, CD45.1(STEM), which is functionally equivalent to CD45.2 cells in competitive BMT. This strain will permit the precise definition of functional roles for candidate genes using in vivo HSPC assays. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A non-redundant function of cyclin E1 in hematopoietic stem cells.

PubMed

Campaner, Stefano; Viale, Andrea; De Fazio, Serena; Doni, Mirko; De Franco, Francesca; D'Artista, Luana; Sardella, Domenico; Pelicci, Pier Giuseppe; Amati, Bruno

2013-12-01

A precise balance between quiescence and proliferation is crucial for the lifelong function of hematopoietic stem cells (HSCs). Cyclins E1 and E2 regulate exit from quiescence in fibroblasts, but their role in HSCs remains unknown. Here, we report a non-redundant role for cyclin E1 in mouse HSCs. A long-term culture-initiating cell (LTC-IC) assay indicated that the loss of cyclin E1, but not E2, compromised the colony-forming activity of primitive hematopoietic progenitors. Ccne1(-/-) mice showed normal hematopoiesis in vivo under homeostatic conditions but a severe impairment following myeloablative stress induced by 5-fluorouracil (5-FU). Under these conditions, Ccne1(-/-) HSCs were less efficient in entering the cell cycle, resulting in decreased hematopoiesis and reduced survival of mutant mice upon weekly 5-FU treatment. The role of cyclin E1 in homeostatic conditions became apparent in aged mice, where HSC quiescence was increased in Ccne1(-/-) animals. On the other hand, loss of cyclin E1 provided HSCs with a competitive advantage in bone marrow serial transplantation assays, suggesting that a partial impairment of cell cycle entry may exert a protective role by preventing premature depletion of the HSC compartment. Our data support a role for cyclin E1 in controlling the exit from quiescence in HSCs. This activity, depending on the physiological context, can either jeopardize or protect the maintenance of hematopoiesis.

Amino acid–insensitive mTORC1 regulation enables nutritional stress resilience in hematopoietic stem cells

PubMed Central

Kalaitzidis, Demetrios; Efeyan, Alejo; Kfoury, Youmna; Nayyar, Naema; Sykes, David B.; Mercier, Francois E.; Papazian, Ani; Baryawno, Ninib; Victora, Gabriel D.; Sabatini, David M.; Scadden, David T.

2017-01-01

The mTOR pathway is a critical determinant of cell persistence and growth wherein mTOR complex 1 (mTORC1) mediates a balance between growth factor stimuli and nutrient availability. Amino acids or glucose facilitates mTORC1 activation by inducing RagA GTPase recruitment of mTORC1 to the lysosomal outer surface, enabling activation of mTOR by the Ras homolog Rheb. Thereby, RagA alters mTORC1-driven growth in times of nutrient abundance or scarcity. Here, we have evaluated differential nutrient-sensing dependence through RagA and mTORC1 in hematopoietic progenitors, which dynamically drive mature cell production, and hematopoietic stem cells (HSC), which provide a quiescent cellular reserve. In nutrient-abundant conditions, RagA-deficient HSC were functionally unimpaired and upregulated mTORC1 via nutrient-insensitive mechanisms. RagA was also dispensable for HSC function under nutritional stress conditions. Similarly, hyperactivation of RagA did not affect HSC function. In contrast, RagA deficiency markedly altered progenitor population function and mature cell output. Therefore, RagA is a molecular mechanism that distinguishes the functional attributes of reactive progenitors from a reserve stem cell pool. The indifference of HSC to nutrient sensing through RagA contributes to their molecular resilience to nutritional stress, a characteristic that is relevant to organismal viability in evolution and in modern HSC transplantation approaches. PMID:28319048

An update on ABO incompatible hematopoietic progenitor cell transplantation.

PubMed

Staley, Elizabeth M; Schwartz, Joseph; Pham, Huy P

2016-06-01

Hematopoietic progenitor cell (HPC) transplantation has long been established as the optimal treatment for many hematologic malignancies. In the setting of allogenic HLA matched HPC transplantation, greater than 50% of unrelated donors and 30% of related donors demonstrate some degree of ABO incompatibility (ABOi), which is classified in one of three ways: major, minor, or bidirectional. Major ABOi refers to the presence of recipient isoagglutinins against the donor's A and/or B antigen. Minor ABOi occurs when the HPC product contains the isoagglutinins targeting the recipient's A and/or B antigen. Bidirectional refers to the presence of both major and minor ABOi. Major adverse events associated with ABOi HPC transplantation includes acute and delayed hemolysis, pure red cell aplasia, and delayed engraftment. ABOi HPC transplantation poses a unique challenge to the clinical transplantation unit, the HPC processing lab, and the transfusion medicine service. Therefore, it is essential that these services actively communicate with one another to ensure patient safety. This review will attempt to globally address the challenges related to ABOi HPC transplantation, with an increased focus on aspects related to the laboratory and transfusion medicine services. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Role of long-term follow-up in management of late-onset post-hematopoietic stem cell transplant complications].

PubMed

Asano-Mori, Yuki

As the number of long-term survivors after allogeneic hematopoietic stem cell transplantation (HSCT) has increased owing to advances in transplantation and supportive care techniques, the health and welfare of these survivors have come into focus. However, they are still at risks for various complications, including chronic graft-versus-host disease, infectious diseases, and secondary cancers even in the late period, which can not only interfere with the patient's quality of life (QOL) but also lead to death. The importance of long-term follow-up (LTFU) and management have been recently recognized, and nationwide systems to promote LTFU care in patients receiving HSCT, such as medical fee revision, publication of a LTFU guideline unique to Japan, and preparation of patient pocketbook, is under consideration. The number of medical facilities at LTFU outpatient clinic is also increasing; therefore, an optimal comprehensive support system may be established sooner or later. However, self-management by patients is essential to overcome late complications as well as to improve QOL after HSCT. Healthcare professionals should collaborate and continue to make the greatest possible efforts to educate patients regarding the risks of late complications and their prevention.

Single low-dose rHuIL-12 safely triggers multilineage hematopoietic and immune-mediated effects

PubMed Central

2014-01-01

Background Recombinant human interleukin 12 (rHuIL-12) regulates hematopoiesis and cell-mediated immunity. Based on these hematopoietic and immunomodulatory activities, a recombinant human IL-12 (rHuIL-12) is now under development to address the unmet need for a medical countermeasure against the hematopoietic syndrome of the acute radiation syndrome (HSARS) that occurs in individuals exposed to lethal radiation, and also to serve as adjuvant therapy that could provide dual hematopoietic and immunotherapeutic benefits in patients with cancer receiving chemotherapy. We sought to demonstrate in healthy subjects the safety of rHuIL-12 at single, low doses that are appropriate for use as a medical countermeasure for humans exposed to lethal radiation and as an immunomodulatory anti-cancer agent. Methods Two placebo-controlled, double-blinded studies assessed the safety, tolerability, pharmacokinetics and pharmacodynamics of rHuIL-12. The first-in-human (FIH) dose-escalation study randomized subjects to single subcutaneous injections of placebo or rHuIL-12 at 2, 5, 10, and 20 μg doses. Due to toxicity, dose was reduced to 15 μg and then to 12 μg. The phase 1b expansion study randomized subjects to the highest safe and well tolerated dose of 12 μg. Results Thirty-two subjects were enrolled in the FIH study: 4 active and 2 placebo at rHuIL-12 doses of 2, 5, 10, 12, and 15 μg; 1 active and 1 placebo at 20 μg. Sixty subjects were enrolled in the expansion study: 48 active and 12 placebo at 12 μg dose of rHuIL-12. In both studies, the most common adverse events (AEs) related to rHuIL-12 were headache, dizziness, and chills. No immunogenicity was observed. Elimination of rHuIL-12 was biphasic, suggesting significant distribution into extravascular spaces. rHuIL-12 triggered transient changes in neutrophils, platelets, reticulocytes, lymphocytes, natural killer cells, and CD34+ hematopoietic progenitor cells, and induced increases in interferon-γ and C-X-C motif chemokine 10. Conclusion A single low dose of rHuIl-12 administered subcutaneously can elicit hematological and immune-mediated effects without undue toxicity. The safety and the potent multilineage hematopoietic/immunologic effects triggered by low-dose rHuIL-12 support the development of rHuIL-12 both as a radiation medical countermeasure and as adjuvant immunotherapy for cancer. Trial registration ClinicalTrials.gov: NCT01742221 PMID:24725395

Is it time for a new classification of mast cells? What do we know about mast cell heterogeneity?

PubMed

Frossi, Barbara; Mion, Francesca; Sibilano, Riccardo; Danelli, Luca; Pucillo, Carlo E M

2018-03-01

Mast cells (MCs) are derived from committed precursors that leave the hematopoietic tissue, migrate in the blood, and colonize peripheral tissues where they terminally differentiate under microenvironment stimuli. They are distributed in almost all vascularized tissues where they act both as immune effectors and housekeeping cells, contributing to tissue homeostasis. Historically, MCs were classified into 2 subtypes, according to tryptic enzymes expression. However, MCs display a striking heterogeneity that reflects a complex interplay between different microenvironmental signals delivered by various tissues, and a differentiation program that decides their identity. Moreover, tissue-specific MCs show a trained memory, which contributes to shape their function in a specific microenvironment. In this review, we summarize the current state of our understanding of MC heterogeneity that reflects their different tissue experiences. We describe the discovery of unique cell molecules that can be used to distinguish specific MC subsets in vivo, and discuss how the improved ability to recognize these subsets provided new insights into the biology of MCs. These recent advances will be helpful for the understanding of the specific role of individual MC subsets in the control of tissue homeostasis, and in the regulation of pathological conditions such as infection, autoimmunity, and cancer. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mitigation of radiation-induced hematopoietic injury by the polyphenolic acetate 7, 8-diacetoxy-4-methylthiocoumarin in mice

PubMed Central

Venkateswaran, Kavya; Shrivastava, Anju; Agrawala, Paban K.; Prasad, Ashok; Kalra, Namita; Pandey, Parvat R.; Manda, Kailash; Raj, Hanumantharao G.; Parmar, Virinder S.; Dwarakanath, Bilikere S.

2016-01-01

Protection of the hematopoietic system from radiation damage, and/or mitigation of hematopoietic injury are the two major strategies for developing medical countermeasure agents (MCM) to combat radiation-induced lethality. In the present study, we investigated the potential of 7, 8-diacetoxy-4-methylthiocoumarin (DAMTC) to ameliorate radiation-induced hematopoietic damage and the associated mortality following total body irradiation (TBI) in C57BL/6 mice. Administration of DAMTC 24 hours post TBI alleviated TBI-induced myelo-suppression and pancytopenia, by augmenting lymphocytes and WBCs in the peripheral blood of mice, while bone marrow (BM) cellularity was restored through enhanced proliferation of the stem cells. It stimulated multi-lineage expansion and differentiation of myeloid progenitors in the BM and induced proliferation of splenic progenitors thereby, facilitating hematopoietic re-population. DAMTC reduced the radiation-induced apoptotic and mitotic death in the hematopoietic compartment. Recruitment of pro-inflammatory M1 macrophages in spleen contributed to the immune-protection linked to the mitigation of hematopoietic injury. Recovery of the hematopoietic compartment correlated well with mitigation of mortality at a lethal dose of 9 Gy, leading to 80% animal survival. Present study establishes the potential of DAMTC to mitigate radiation-induced injury to the hematopoietic system by stimulating the re-population of stem cells from multiple lineages. PMID:27849061

Lack of Phenotypical and Morphological Evidences of Endothelial to Hematopoietic Transition in the Murine Embryonic Head during Hematopoietic Stem Cell Emergence.

PubMed

Iizuka, Kazuhide; Yokomizo, Tomomasa; Watanabe, Naoki; Tanaka, Yosuke; Osato, Motomi; Takaku, Tomoiku; Komatsu, Norio

2016-01-01

During mouse ontogeny, hematopoietic cells arise from specialized endothelial cells, i.e., the hemogenic endothelium, and form clusters in the lumen of arterial vessels. Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work suggests that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head has not yet been determined because the hematopoietic clusters and hemogenic endothelium in the head region have not been well characterized. In this study, we used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit+ hematopoietic clusters and Runx1+ hemogenic endothelium in the whole-head vasculature. The number of c-Kit+ hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, apparent nascent hematopoietic cells, which are characterized by a "budding" structure and a Runx1+ hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs.

Lack of Phenotypical and Morphological Evidences of Endothelial to Hematopoietic Transition in the Murine Embryonic Head during Hematopoietic Stem Cell Emergence

PubMed Central

Iizuka, Kazuhide; Yokomizo, Tomomasa; Watanabe, Naoki; Tanaka, Yosuke; Osato, Motomi; Takaku, Tomoiku; Komatsu, Norio

2016-01-01

During mouse ontogeny, hematopoietic cells arise from specialized endothelial cells, i.e., the hemogenic endothelium, and form clusters in the lumen of arterial vessels. Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work suggests that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head has not yet been determined because the hematopoietic clusters and hemogenic endothelium in the head region have not been well characterized. In this study, we used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit+ hematopoietic clusters and Runx1+ hemogenic endothelium in the whole-head vasculature. The number of c-Kit+ hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, apparent nascent hematopoietic cells, which are characterized by a “budding” structure and a Runx1+ hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs. PMID:27227884

Effect of Calcium-Infiltrated Hydroxyapatite Scaffolds on the Hematopoietic Fate of Human Umbilical Vein Endothelial Cells.

PubMed

Zhang, Qinghao; Gerlach, Jörg C; Schmelzer, Eva; Nettleship, Ian

2017-01-01

Foamed hydroxyapatite offers a three-dimensional scaffold for the development of bone constructs, mimicking perfectly the in vivo bone structure. In vivo, calcium release at the surface is assumed to provide a locally increased gradient supporting the maintenance of the hematopoietic stem cells niche. We fabricated hydroxyapatite scaffolds with high surface calcium concentration by infiltration, and used human umbilical vein endothelial cells (HUVECs) as a model to study the effects on hematopoietic lineage direction. HUVECs are umbilical vein-derived and thus possess progenitor characteristics, with a prospective potential to give rise to hematopoietic lineages. HUVECs were cultured for long term on three-dimensional porous hydroxyapatite scaffolds, which were either infiltrated biphasic foams or untreated. Controls were cultured in two-dimensional dishes. The release of calcium into culture medium was determined, and cells were analyzed for typical hematopoietic and endothelial gene expressions, surface markers by flow cytometry, and hematopoietic potential using colony-forming unit assays. Our results indicate that the biphasic foams promoted a hematopoietic lineage direction of HUVECs, suggesting an improved in vivo-like scaffold for hematopoietic bone tissue engineering. © 2017 S. Karger AG, Basel.

Autophagy in stem cells

PubMed Central

Guan, Jun-Lin; Simon, Anna Katharina; Prescott, Mark; Menendez, Javier A.; Liu, Fei; Wang, Fen; Wang, Chenran; Wolvetang, Ernst; Vazquez-Martin, Alejandro; Zhang, Jue

2013-01-01

Autophagy is a highly conserved cellular process by which cytoplasmic components are sequestered in autophagosomes and delivered to lysosomes for degradation. As a major intracellular degradation and recycling pathway, autophagy is crucial for maintaining cellular homeostasis as well as remodeling during normal development, and dysfunctions in autophagy have been associated with a variety of pathologies including cancer, inflammatory bowel disease and neurodegenerative disease. Stem cells are unique in their ability to self-renew and differentiate into various cells in the body, which are important in development, tissue renewal and a range of disease processes. Therefore, it is predicted that autophagy would be crucial for the quality control mechanisms and maintenance of cellular homeostasis in various stem cells given their relatively long life in the organisms. In contrast to the extensive body of knowledge available for somatic cells, the role of autophagy in the maintenance and function of stem cells is only beginning to be revealed as a result of recent studies. Here we provide a comprehensive review of the current understanding of the mechanisms and regulation of autophagy in embryonic stem cells, several tissue stem cells (particularly hematopoietic stem cells), as well as a number of cancer stem cells. We discuss how recent studies of different knockout mice models have defined the roles of various autophagy genes and related pathways in the regulation of the maintenance, expansion and differentiation of various stem cells. We also highlight the many unanswered questions that will help to drive further research at the intersection of autophagy and stem cell biology in the near future. PMID:23486312

The TGFβ pathway is a key player for the endothelial-to-hematopoietic transition in the embryonic aorta.

PubMed

Lempereur, A; Canto, P Y; Richard, C; Martin, S; Thalgott, J; Raymond, K; Lebrin, F; Drevon, C; Jaffredo, T

2018-02-15

The embryonic aorta produces hematopoietic stem and progenitor cells from a hemogenic endothelium localized in the aortic floor through an endothelial to hematopoietic transition. It has been long proposed that the Bone Morphogenetic Protein (BMP)/Transforming Growth Factor ß (TGFß) signaling pathway was implicated in aortic hematopoiesis but the very nature of the signal was unknown. Here, using thorough expression analysis of the BMP/TGFß signaling pathway members in the endothelial and hematopoietic compartments of the aorta at pre-hematopoietic and hematopoietic stages, we show that the TGFß pathway is preferentially balanced with a prominent role of Alk1/TgfßR2/Smad1 and 5 on both chicken and mouse species. Functional analysis using embryonic stem cells mutated for Acvrl1 revealed an enhanced propensity to produce hematopoietic cells. Collectively, we reveal that TGFß through the Alk1/TgfßR2 receptor axis is acting on endothelial cells to produce hematopoiesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Regulation of vesicular trafficking and leukocyte function by Rab27 GTPases and their effectors

PubMed Central

Catz, Sergio Daniel

2013-01-01

The Rab27 family of GTPases regulates the efficiency and specificity of exocytosis in hematopoietic cells, including neutrophils, CTLs, NK cells, and mast cells. However, the mechanisms regulated by Rab27 GTPases are cell-specific, as they depend on the differential expression and function of particular effector molecules that are recruited by the GTPases. In addition, Rab27 GTPases participate in multiple steps of the regulation of the secretory process, including priming, tethering, docking, and fusion through sequential interaction with multiple effector molecules. Finally, recent reports suggest that Rab27 GTPases and their effectors regulate vesicular trafficking mechanisms other than exocytosis, including endocytosis and phagocytosis. This review focuses on the latest discoveries on the function of Rab27 GTPases and their effectors Munc13-4 and Slp1 in neutrophil function comparatively to their functions in other leukocytes. PMID:23378593

Outcomes of hematopoietic cell transplantation using donors or recipients with inherited chromosomally integrated HHV-6.

PubMed

Hill, Joshua A; Magaret, Amalia S; Hall-Sedlak, Ruth; Mikhaylova, Anna; Huang, Meei-Li; Sandmaier, Brenda M; Hansen, John A; Jerome, Keith R; Zerr, Danielle M; Boeckh, Michael

2017-08-24

Human herpesvirus 6 (HHV-6) species have a unique ability to integrate into chromosomal telomeres. Mendelian inheritance via gametocyte integration results in HHV-6 in every nucleated cell. The epidemiology and clinical effect of inherited chromosomally integrated HHV-6 (iciHHV-6) in hematopoietic cell transplant (HCT) recipients is unclear. We identified 4319 HCT donor-recipient pairs (8638 subjects) who received an allogeneic HCT and had archived pre-HCT peripheral blood mononuclear cell samples. We screened these samples for iciHHV-6 and compared characteristics of HCT recipients and donors with iciHHV-6 with those of recipients and donors without iciHHV-6, respectively. We calculated Kaplan-Meier probability estimates and Cox proportional hazards models for post-HCT outcomes based on recipient and donor iciHHV-6 status. We identified 60 HCT recipients (1.4%) and 40 donors (0.9%) with iciHHV-6; both recipient and donor harbored iciHHV-6 in 13 HCTs. Thus, there were 87 HCTs (2%) in which the recipient, donor, or both harbored iciHHV-6. Acute graft-versus-host disease (GVHD) grades 2-4 was more frequent when recipients or donors had iciHHV-6 (adjusted hazard ratios, 1.7-1.9; P = .004-.001). Cytomegalovirus viremia (any and high-level) was more frequent among recipients with iciHHV-6 (adjusted HRs, 1.7-3.1; P = .001-.040). Inherited ciHHV-6 status did not significantly affect risk for chronic GVHD, hematopoietic cell engraftment, overall mortality, or nonrelapse mortality. Screening for iciHHV-6 could guide donor selection and post-HCT risk stratification and treatment. Further study is needed to replicate these findings and identify potential mechanisms. © 2017 by The American Society of Hematology.

Gene Editing of Human Hematopoietic Stem and Progenitor Cells: Promise and Potential Hurdles.

PubMed

Yu, Kyung-Rok; Natanson, Hannah; Dunbar, Cynthia E

2016-10-01

Hematopoietic stem and progenitor cells (HSPCs) have great therapeutic potential because of their ability to both self-renew and differentiate. It has been proposed that, given their unique properties, a small number of genetically modified HSPCs could accomplish lifelong, corrective reconstitution of the entire hematopoietic system in patients with various hematologic disorders. Scientists have demonstrated that gene addition therapies-targeted to HSPCs and using integrating retroviral vectors-possess clear clinical benefits in multiple diseases, among them immunodeficiencies, storage disorders, and hemoglobinopathies. Scientists attempting to develop clinically relevant gene therapy protocols have, however, encountered a number of unexpected hurdles because of their incomplete knowledge of target cells, genomic control, and gene transfer technologies. Targeted gene-editing technologies using engineered nucleases such as ZFN, TALEN, and/or CRISPR/Cas9 RGEN show great clinical promise, allowing for the site-specific correction of disease-causing mutations-a process with important applications in autosomal dominant or dominant-negative genetic disorders. The relative simplicity of the CRISPR/Cas9 system, in particular, has sparked an exponential increase in the scientific community's interest in and use of these gene-editing technologies. In this minireview, we discuss the specific applications of gene-editing technologies in human HSPCs, as informed by prior experience with gene addition strategies. HSPCs are desirable but challenging targets; the specific mechanisms these cells evolved to protect themselves from DNA damage render them potentially more susceptible to oncogenesis, especially given their ability to self-renew and their long-term proliferative potential. We further review scientists' experience with gene-editing technologies to date, focusing on strategies to move these techniques toward implementation in safe and effective clinical trials.

A novel CBL-Bflox/flox mouse model allows tissue-selective fully conditional CBL/CBL-B double-knockout: CD4-Cre mediated CBL/CBL-B deletion occurs in both T-cells and hematopoietic stem cells

PubMed Central

Goetz, Benjamin; An, Wei; Mohapatra, Bhopal; Zutshi, Neha; Iseka, Fany; Storck, Matthew D.; Meza, Jane; Sheinin, Yuri; Band, Vimla; Band, Hamid

2016-01-01

CBL-family ubiquitin ligases are critical negative regulators of tyrosine kinase signaling, with a clear redundancy between CBL and CBL-B evident in the immune cell and hematopoietic stem cell studies. Since CBL and CBL-B are negative regulators of immune cell activation, elimination of their function to boost immune cell activities could be beneficial in tumor immunotherapy. However, mutations of CBL are associated with human leukemias, pointing to tumor suppressor roles of CBL proteins; hence, it is critical to assess the tumor-intrinsic roles of CBL and CBL-B in cancers. This has not been possible since the only available whole-body CBL-B knockout mice exhibit constitutive tumor rejection. We engineered a new CBL-Bflox/flox mouse, combined this with an existing CBLflox/flox mouse to generate CBLflox/flox; CBL-Bflox/flox mice, and tested the tissue-specific concurrent deletion of CBL and CBL-B using the widely-used CD4-Cre transgenic allele to produce a T-cell-specific double knockout. Altered T-cell development, constitutive peripheral T-cell activation, and a lethal multi-organ immune infiltration phenotype largely resembling the previous Lck-Cre driven floxed-CBL deletion on a CBL-B knockout background establish the usefulness of the new model for tissue-specific CBL/CBL-B deletion. Unexpectedly, CD4-Cre-induced deletion in a small fraction of hematopoietic stem cells led to expansion of certain non-T-cell lineages, suggesting caution in the use of CD4-Cre for T-cell-restricted gene deletion. The establishment of a new model of concurrent tissue-selective CBL/CBL-B deletion should allow a clear assessment of the tumor-intrinsic roles of CBL/CBL-B in non-myeloid malignancies and help test the potential for CBL/CBL-B inactivation in immunotherapy of tumors. PMID:27276677

Generation of Transgenic Mouse Fluorescent Reporter Lines for Studying Hematopoietic Development

PubMed Central

Vacaru, Andrei M.; Vitale, Joseph; Nieves, Johnathan; Baron, Margaret H.

2015-01-01

During the development of the hematopoietic system, at least 8 distinct lineages are generated in the mouse embryo. Transgenic mice expressing fluorescent proteins at various points in the hematopoietic hierarchy, from hematopoietic stem cell to multipotent progenitors to each of the final differentiated cell types, have provided valuable tools for tagging, tracking, and isolating these cells. In this chapter, we discuss general considerations in designing a transgene, survey available fluorescent probes, and methods for confirming and analyzing transgene expression in the hematopoietic systems of the embryo, fetus, and postnatal/adult animal. PMID:25064110

Autologous Hematopoietic Stem Cell Transplantation to Prevent Antibody Mediated Rejection After Vascularized Composite Allotransplantation

DTIC Science & Technology

2017-10-01

Award Number: W81XWH-16-1-0664 TITLE: Autologous Hematopoietic Stem Cell Transplantation to Prevent Antibody-Mediated Rejection after...Annual 3. DATES COVERED 15 Sep 2016 – 14 Sep 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Autologous Hematopoietic Stem Cell Transplantation to...sensitization, autologous hematopoietic stem cell transplantation, antibody mediated rejection, donor specific antibodies 16. SECURITY CLASSIFICATION OF

Insulin-Like Growth Factor 1 Mitigates Hematopoietic Toxicity After Lethal Total Body Irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Dunhua; Deoliveira, Divino; Kang, Yubin

2013-03-15

Purpose: To investigate whether and how insulin-like growth factor 1 (IGF-1) mitigates hematopoietic toxicity after total body irradiation. Methods and Materials: BALB/c mice were irradiated with a lethal dose of radiation (7.5 Gy) and treated with IGF-1 at a dose of 100 μg/dose intravenously once a day for 5 consecutive days starting within 1 hour after exposure. Survival and hematopoietic recovery were monitored. The mechanisms by which IGF-1 promotes hematopoietic recovery were also studied by use of an in vitro culture system. Results: IGF-1 protected 8 of 20 mice (40%) from lethal irradiation, whereas only 2 of 20 mice (10%) inmore » the saline control group survived for more than 100 days after irradiation. A single dose of IGF-1 (500 μg) was as effective as daily dosing for 5 days. Positive effects were noted even when the initiation of treatment was delayed as long as 6 hours after irradiation. In comparison with the saline control group, treatment with IGF-1 significantly accelerated the recovery of both platelets and red blood cells in peripheral blood, total cell numbers, hematopoietic stem cells, and progenitor cells in the bone marrow when measured at day 14 after irradiation. IGF-1 protected both hematopoietic stem cells and progenitor cells from radiation-induced apoptosis and cell death. In addition, IGF-1 was able to facilitate the proliferation and differentiation of nonirradiated and irradiated hematopoietic progenitor cells. Conclusions: IGF-1 mitigates radiation-induced hematopoietic toxicity through protecting hematopoietic stem cells and progenitor cells from apoptosis and enhancing proliferation and differentiation of the surviving hematopoietic progenitor cells.« less

Hematological alterations in protein malnutrition.

PubMed

Santos, Ed W; Oliveira, Dalila C; Silva, Graziela B; Tsujita, Maristela; Beltran, Jackeline O; Hastreiter, Araceli; Fock, Ricardo A; Borelli, Primavera

2017-11-01

Protein malnutrition is one of the most serious nutritional problems worldwide, affecting 794 million people and costing up to $3.5 trillion annually in the global economy. Protein malnutrition primarily affects children, the elderly, and hospitalized patients. Different degrees of protein deficiency lead to a broad spectrum of signs and symptoms of protein malnutrition, especially in organs in which the hematopoietic system is characterized by a high rate of protein turnover and, consequently, a high rate of protein renewal and cellular proliferation. Here, the current scientific information about protein malnutrition and its effects on the hematopoietic process is reviewed. The production of hematopoietic cells is described, with special attention given to the hematopoietic microenvironment and the development of stem cells. Advances in the study of hematopoiesis in protein malnutrition are also summarized. Studies of protein malnutrition in vitro, in animal models, and in humans demonstrate several alterations that impair hematopoiesis, such as structural changes in the extracellular matrix, the hematopoietic stem cell niche, the spleen, the thymus, and bone marrow stromal cells; changes in mesenchymal and hematopoietic stem cells; increased autophagy; G0/G1 cell-cycle arrest of progenitor hematopoietic cells; and functional alterations in leukocytes. Structural and cellular changes of the hematopoietic microenvironment in protein malnutrition contribute to bone marrow atrophy and nonestablishment of hematopoietic stem cells, resulting in impaired homeostasis and an impaired immune response. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Lineage-Specific Genome Architecture Links Enhancers and Non-coding Disease Variants to Target Gene Promoters.

PubMed

Javierre, Biola M; Burren, Oliver S; Wilder, Steven P; Kreuzhuber, Roman; Hill, Steven M; Sewitz, Sven; Cairns, Jonathan; Wingett, Steven W; Várnai, Csilla; Thiecke, Michiel J; Burden, Frances; Farrow, Samantha; Cutler, Antony J; Rehnström, Karola; Downes, Kate; Grassi, Luigi; Kostadima, Myrto; Freire-Pritchett, Paula; Wang, Fan; Stunnenberg, Hendrik G; Todd, John A; Zerbino, Daniel R; Stegle, Oliver; Ouwehand, Willem H; Frontini, Mattia; Wallace, Chris; Spivakov, Mikhail; Fraser, Peter

2016-11-17

Long-range interactions between regulatory elements and gene promoters play key roles in transcriptional regulation. The vast majority of interactions are uncharted, constituting a major missing link in understanding genome control. Here, we use promoter capture Hi-C to identify interacting regions of 31,253 promoters in 17 human primary hematopoietic cell types. We show that promoter interactions are highly cell type specific and enriched for links between active promoters and epigenetically marked enhancers. Promoter interactomes reflect lineage relationships of the hematopoietic tree, consistent with dynamic remodeling of nuclear architecture during differentiation. Interacting regions are enriched in genetic variants linked with altered expression of genes they contact, highlighting their functional role. We exploit this rich resource to connect non-coding disease variants to putative target promoters, prioritizing thousands of disease-candidate genes and implicating disease pathways. Our results demonstrate the power of primary cell promoter interactomes to reveal insights into genomic regulatory mechanisms underlying common diseases. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Development and differentiation of the erythroid lineage in mammals

PubMed Central

Barminko, Jeffrey; Reinholt, Brad; Baron, Margaret H.

2016-01-01

Summary The red blood cell (RBC) is responsible for performing the highly specialized function of oxygen transport, making it essential for survival during gestation and postnatal life. Establishment of sufficient RBC numbers, therefore, has evolved to be a major priority of the postimplantation embryo. The “primitive” erythroid lineage is the first to be specified in the developing embryo proper. Significant resources are dedicated to producing RBCs throughout gestation. Two transient and morphologically distinct waves of hematopoietic progenitor-derived erythropoiesis are observed in development before hematopoietic stem cells (HSCs) take over to produce “definitive” RBCs in the fetal liver. Toward the end of gestation, HSCs migrate to the bone marrow, which becomes the primary site of RBC production in the adult. Erythropoiesis is regulated at various stages of erythroid cell maturation to ensure sufficient production of RBCs in response to physiological demands. Here, we highlight key aspects of mammalian erythroid development and maturation as well as differences among the primitive and definitive erythroid cell lineages. PMID:26709231

Drug discovery for Diamond-Blackfan anemia using reprogrammed hematopoietic progenitors

PubMed Central

Doulatov, Sergei; Vo, Linda T.; Macari, Elizabeth R.; Wahlster, Lara; Kinney, Melissa A.; Taylor, Alison M.; Barragan, Jessica; Gupta, Manav; McGrath, Katherine; Lee, Hsiang-Ying; Humphries, Jessica M.; DeVine, Alex; Narla, Anupama; Alter, Blanche P.; Beggs, Alan H.; Agarwal, Suneet; Ebert, Benjamin L.; Gazda, Hanna T.; Lodish, Harvey F.; Sieff, Colin A.; Schlaeger, Thorsten M.; Zon, Leonard I.; Daley, George Q.

2017-01-01

Diamond-Blackfan anemia (DBA) is a congenital disorder characterized by the failure of erythroid progenitor differentiation, severely curtailing red blood cell production. Because many DBA patients fail to respond to corticosteroid therapy, there is considerable need for therapeutics for this disorder. Identifying therapeutics for DBA requires circumventing the paucity of primary patient blood stem and progenitor cells. To this end, we adopted a reprogramming strategy to generate expandable hematopoietic progenitor cells from induced pluripotent stem cells (iPSCs) from DBA patients. Reprogrammed DBA progenitors recapitulate defects in erythroid differentiation, which were rescued by gene complementation. Unbiased chemical screens identified SMER28, a small-molecule inducer of autophagy, which enhanced erythropoiesis in a range of in vitro and in vivo models of DBA. SMER28 acted through autophagy factor ATG5 to stimulate erythropoiesis and up-regulate expression of globin genes. These findings present an unbiased drug screen for hematological disease using iPSCs and identify autophagy as a therapeutic pathway in DBA. PMID:28179501

A Quantitative Proteomic Analysis of Hemogenic Endothelium Reveals Differential Regulation of Hematopoiesis by SOX17

PubMed Central

Clarke, Raedun L.; Robitaille, Aaron M.; Moon, Randall T.; Keller, Gordon

2015-01-01

Summary The in vitro derivation of hematopoietic stem cells (HSCs) from pluripotent stem cells (PSCs) is complicated by the existence of multiple overlapping embryonic blood cell programs called primitive, erythromyeloid progenitor (EMP), and definitive. As HSCs are only generated during the definitive stage of hematopoiesis, deciphering the regulatory pathways that control the emergence of this program and identifying markers that distinguish it from the other programs are essential. To identify definitive specific pathways and marker sets, we used label-free proteomics to determine the proteome of embryo-derived and mouse embryonic stem cell-derived VE-CADHERIN+CD45− definitive hematopoietic progenitors. With this approach, we identified Stat1 as a marker that distinguishes the definitive erythroid lineage from the primitive- and EMP-derived lineages. Additionally, we provide evidence that the generation of the Stat1+ definitive lineage is dependent on Sox17. These findings establish an approach for monitoring the emergence of definitive hematopoiesis in the PSC differentiation cultures. PMID:26267830

Pleiotrophin mediates hematopoietic regeneration via activation of RAS.

PubMed

Himburg, Heather A; Yan, Xiao; Doan, Phuong L; Quarmyne, Mamle; Micewicz, Eva; McBride, William; Chao, Nelson J; Slamon, Dennis J; Chute, John P

2014-11-01

Hematopoietic stem cells (HSCs) are highly susceptible to ionizing radiation-mediated death via induction of ROS, DNA double-strand breaks, and apoptotic pathways. The development of therapeutics capable of mitigating ionizing radiation-induced hematopoietic toxicity could benefit both victims of acute radiation sickness and patients undergoing hematopoietic cell transplantation. Unfortunately, therapies capable of accelerating hematopoietic reconstitution following lethal radiation exposure have remained elusive. Here, we found that systemic administration of pleiotrophin (PTN), a protein that is secreted by BM-derived endothelial cells, substantially increased the survival of mice following radiation exposure and after myeloablative BM transplantation. In both models, PTN increased survival by accelerating the recovery of BM hematopoietic stem and progenitor cells in vivo. PTN treatment promoted HSC regeneration via activation of the RAS pathway in mice that expressed protein tyrosine phosphatase receptor-zeta (PTPRZ), whereas PTN treatment did not induce RAS signaling in PTPRZ-deficient mice, suggesting that PTN-mediated activation of RAS was dependent upon signaling through PTPRZ. PTN strongly inhibited HSC cycling following irradiation, whereas RAS inhibition abrogated PTN-mediated induction of HSC quiescence, blocked PTN-mediated recovery of hematopoietic stem and progenitor cells, and abolished PTN-mediated survival of irradiated mice. These studies demonstrate the therapeutic potential of PTN to improve survival after myeloablation and suggest that PTN-mediated hematopoietic regeneration occurs in a RAS-dependent manner.

Inflamm-Aging of Hematopoiesis, Hematopoietic Stem Cells, and the Bone Marrow Microenvironment

PubMed Central

Kovtonyuk, Larisa V.; Fritsch, Kristin; Feng, Xiaomin; Manz, Markus G.; Takizawa, Hitoshi

2016-01-01

All hematopoietic and immune cells are continuously generated by hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) through highly organized process of stepwise lineage commitment. In the steady state, HSCs are mostly quiescent, while HPCs are actively proliferating and contributing to daily hematopoiesis. In response to hematopoietic challenges, e.g., life-threatening blood loss, infection, and inflammation, HSCs can be activated to proliferate and engage in blood formation. The HSC activation induced by hematopoietic demand is mediated by direct or indirect sensing mechanisms involving pattern recognition receptors or cytokine/chemokine receptors. In contrast to the hematopoietic challenges with obvious clinical symptoms, how the aging process, which involves low-grade chronic inflammation, impacts hematopoiesis remains undefined. Herein, we summarize recent findings pertaining to functional alternations of hematopoiesis, HSCs, and the bone marrow (BM) microenvironment during the processes of aging and inflammation and highlight some common cellular and molecular changes during the processes that influence hematopoiesis and its cells of origin, HSCs and HPCs, as well as the BM microenvironment. We also discuss how age-dependent alterations of the immune system lead to subclinical inflammatory states and how inflammatory signaling might be involved in hematopoietic aging. Our aim is to present evidence supporting the concept of “Inflamm-Aging,” or inflammation-associated aging of hematopoiesis. PMID:27895645

Erythro-Myeloid Progenitors: “definitive” hematopoiesis in the conceptus prior to the emergence of hematopoietic stem cells

PubMed Central

Frame, Jenna M.; McGrath, Kathleen E.; Palis, James

2013-01-01

Erythro-myeloid progenitors (EMP) serve as a major source of hematopoiesis in the developing conceptus prior to the formation of a permanent blood system. In this review, we summarize the current knowledge regarding the emergence, fate, and potential of this hematopoietic stem cell (HSC)-independent wave of hematopoietic progenitors, focusing on the murine embryo as a model system. A better understanding of the temporal and spatial control of hematopoietic emergence in the embryo will ultimately improve our ability to derive hematopoietic stem and progenitor cells from embryonic stem cells and induced pluripotent stem cells to serve therapeutic purposes. PMID:24095199

Donor Dependent Variations in Hematopoietic Differentiation among Embryonic and Induced Pluripotent Stem Cell Lines

PubMed Central

Féraud, Olivier; Valogne, Yannick; Melkus, Michael W.; Zhang, Yanyan; Oudrhiri, Noufissa; Haddad, Rima; Daury, Aurélie; Rocher, Corinne; Larbi, Aniya; Duquesnoy, Philippe; Divers, Dominique; Gobbo, Emilie; Brunet de la Grange, Philippe; Louache, Fawzia; Bennaceur-Griscelli, Annelise; Mitjavila-Garcia, Maria Teresa

2016-01-01

Hematopoiesis generated from human embryonic stem cells (ES) and induced pluripotent stem cells (iPS) are unprecedented resources for cell therapy. We compared hematopoietic differentiation potentials from ES and iPS cell lines originated from various donors and derived them using integrative and non-integrative vectors. Significant differences in differentiation toward hematopoietic lineage were observed among ES and iPS. The ability of engraftment of iPS or ES-derived cells in NOG mice varied among the lines with low levels of chimerism. iPS generated from ES cell-derived mesenchymal stem cells (MSC) reproduce a similar hematopoietic outcome compared to their parental ES cell line. We were not able to identify any specific hematopoietic transcription factors that allow to distinguish between good versus poor hematopoiesis in undifferentiated ES or iPS cell lines. There is a relatively unpredictable variation in hematopoietic differentiation between ES and iPS cell lines that could not be predicted based on phenotype or gene expression of the undifferentiated cells. These results demonstrate the influence of genetic background in variation of hematopoietic potential rather than the reprogramming process. PMID:26938212

Biology and flow cytometry of proangiogenic hematopoietic progenitors cells.

PubMed

Rose, Jonathan A; Erzurum, Serpil; Asosingh, Kewal

2015-01-01

During development, hematopoiesis and neovascularization are closely linked to each other via a common bipotent stem cell called the hemangioblast that gives rise to both hematopoietic cells and endothelial cells. In postnatal life, this functional connection between the vasculature and hematopoiesis is maintained by a subset of hematopoietic progenitor cells endowed with the capacity to differentiate into potent proangiogenic cells. These proangiogenic hematopoietic progenitors comprise a specific subset of bone marrow (BM)-derived cells that homes to sites of neovascularization and possess potent paracrine angiogenic activity. There is emerging evidence that this subpopulation of hematopoietic progenitors plays a critical role in vascular health and disease. Their angiogenic activity is distinct from putative "endothelial progenitor cells" that become structural cells of the endothelium by differentiation into endothelial cells. Proangiogenic hematopoietic progenitor cell research requires multidisciplinary expertise in flow cytometry, hematology, and vascular biology. This review provides a comprehensive overview of proangiogenic hematopoietic progenitor cell biology and flow cytometric methods to detect these cells in the peripheral blood circulation and BM. © 2014 International Society for Advancement of Cytometry.

Structural Basis of Substrate Recognition by Hematopoietic Tyrosine Phosphatase (HePTP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Critton, D.; Tortajada, A; Stetson, G

2008-01-01

Hematopoietic tyrosine phosphatase (HePTP) is one of three members of the kinase interaction motif (KIM) phosphatase family which also includes STEP and PCPTP1. The KIM-PTPs are characterized by a 15 residue sequence, the KIM, which confers specific high-affinity binding to their only known substrates, the MAP kinases Erk and p38, an interaction which is critical for their ability to regulate processes such as T cell differentiation (HePTP) and neuronal signaling (STEP). The KIM-PTPs are also characterized by a unique set of residues in their PTP substrate binding loops, where 4 of the 13 residues are differentially conserved among the KIM-PTPsmore » as compared to more than 30 other class I PTPs. One of these residues, T106 in HePTP, is either an aspartate or asparagine in nearly every other PTP. Using multiple techniques, we investigate the role of these KIM-PTP specific residues in order to elucidate the molecular basis of substrate recognition by HePTP. First, we used NMR spectroscopy to show that Erk2-derived peptides interact specifically with HePTP at the active site. Next, to reveal the molecular details of this interaction, we solved the high-resolution three-dimensional structures of two distinct HePTP-Erk2 peptide complexes. Strikingly, we were only able to obtain crystals of these transient complexes using a KIM-PTP specific substrate-trapping mutant, in which the KIM-PTP specific residue T106 was mutated to an aspartic acid (T106D). The introduced aspartate side chain facilitates the coordination of the bound peptides, thereby stabilizing the active dephosphorylation complex. These structures establish the essential role of HePTP T106 in restricting HePTP specificity to only those substrates which are able to interact with KIM-PTPs via the KIM (e.g., Erk2, p38). Finally, we describe how this interaction of the KIM is sufficient for overcoming the otherwise weak interaction at the active site of KIM-PTPs.« less

Chronic myelomonocytic leukemia: Forefront of the field in 2015

PubMed Central

Benton, Christopher B; Nazha, Aziz; Pemmaraju, Naveen; Garcia-Manero, Guillermo

2016-01-01

Chronic myelomonocytic leukemia (CMML) includes components of both myelodysplastic syndrome and myeloproliferative neoplasms and is associated with a characteristic peripheral monocytosis. CMML is caused by the proliferation of an abnormal hematopoietic stem cell clone and may be influenced by microenvironmental changes. The disease is rare and has undergone revisions in its classification. We review the recent classification strategies as well as diagnostic criteria, focusing on CMML’s genetic alterations and unique pathophysiology. We also discuss the latest molecular characterization of the disease, including how molecular factors affect current prognostic models. Finally, we focus on available treatment strategies, with a special emphasis on experimental and forthcoming therapies. PMID:25869097

Protective Role of Angiogenin Against Hematopoietic Syndrome of the Acute Radiation Syndrome

DTIC Science & Technology

2017-05-01

AWARD NUMBER: W81XWH-15-1-0207 TITLE: “Protective Role of Angiogenin Against Hematopoietic Syndrome of the Acute Radiation Syndrome ...SUBTITLE Protective Role of Angiogenin Against Hematopoietic Syndrome 5a. CONTRACT NUMBER of the Acute Radiation Syndrome 5b. GRANT NUMBER 5c...hematopoietic syndrome of the acute radiation syndrome (H-ARS) and is able to attenuate the effect of residual bone marrow damage (RBMD) after

An Analysis of microRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-13-1-0082 TITLE: An Analysis of microRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells ...syndromes (MDS) to identify microRNAs (miRNAs) dysregulated in MDS hematopoietic stem cells (MDS HSCs) as compared with normal HSCs. MiRNAs differentially...the age-related predisposition for the development of MDS. 15. SUBJECT TERMS MicroRNAs, the myelodysplastic syndromes, hematopoietic stem cells

An Analysis of MicroRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells

DTIC Science & Technology

2015-10-01

AWARD NUMBER: W81XWH-13-1-0082 TITLE: An Analysis of microRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells ...syndromes (MDS) to identify microRNAs (miRNAs) dysregulated in MDS hematopoietic stem cells (MDS HSCs) as compared with normal HSCs. MiRNAs differentially...the age-related predisposition for the development of MDS. 15. SUBJECT TERMS MicroRNAs, the myelodysplastic syndromes, hematopoietic stem cells

Selection of genetically modified hematopoietic cells in vitro and in vivo using alkylating agent lysomustine.

PubMed

Rozov, F N; Grinenko, T S; Levit, G L; Krasnov, V P; Belyavsky, A V

2010-09-15

Efficient gene transfer into hematopoietic stem cells is vital for the success of gene therapy of hematopoietic and immune system disorders. An in vivo selection system based on a mutant form of the O(6)-methylguanine-DNA-methyltransferase gene (MGMTm) is considered one of the more promising strategies for expansion of hematopoietic cells transduced with viral vectors. Here we demonstrate that MGMTm-expressing cells can be efficiently selected using lysomustine, a nitrosourea derivative of lysine. K562 and murine bone marrow cells expressing MGMTm are protected from the cytotoxic action of lysomustine in vitro. We also show in a murine model that MGMTm-transduced hematopoietic cells can be expanded in vivo on transplantation into sublethally irradiated recipients followed by lysomustine treatment. These results indicate that lysomustine can be used as a potent novel chemoselection drug applicable for gene therapy of hematopoietic and immune system disorders. 2010 Elsevier Inc. All rights reserved.

Loss of aryl hydrocarbon receptor promotes gene changes associated with premature hematopoietic stem cell exhaustion and development of a myeloproliferative disorder in aging mice.

PubMed

Singh, Kameshwar P; Bennett, John A; Casado, Fanny L; Walrath, Jason L; Welle, Stephen L; Gasiewicz, Thomas A

2014-01-15

Loss of immune function and increased hematopoietic disease are among the most clinically significant consequences of aging. Hematopoietic stem cells (HSCs) from mice lacking aryl hydrocarbon receptor (AhR) have high rates of cell division. Studies were designed to test the hypothesis that aging AhR-null allele (AhR-KO) mice develop premature HSC exhaustion, and changes leading to hematological disease. Compared to wild-type, aging AhR-KO mice showed a decreased survival rate, splenomegaly, increased circulating white blood cells, hematopoietic cell accumulation in tissues, and anemia. Analysis of bone marrow indicated increased numbers of stem/progenitor and lineage-committed cells, but decreased erythroid progenitors. There was also decreased self-renewal capacity of HSCs determined by competitive repopulation and serial transplantation. HSCs also showed increased levels of reactive oxygen species (ROS), Ki-67, and γ-H2A.X, but decreased p16(Ink4a). Splenic cells from aging KO mice had abnormal expression of genes, including Gata-1, Sh2d3c, Gfi-1, p21, and c-myc, involved in trafficking and associated with leukemia. HSCs from AhR-KO mice had gene changes related to HSC maintenance and consistent with phenotype observed. The most prominent gene changes (overexpression of Srpk2, Creb1, Hes1, mtor, pdp1) have been associated with HSC hyperproliferation, leukemia, and accelerated aging. Pathway analyses also indicated an enrichment of genes associated with oxidative stress, acute myelogenous leukemia, aging, and heat shock response, and the β-catenin/Wnt pathways. These data indicate that loss of AhR and associated changes in multiple signaling pathways promote premature HSC exhaustion and development of a myeloproliferative disorder. They also implicate a critical role of the AhR in the regulation of HSCs.

Deficiency in Aryl Hydrocarbon Receptor (AHR) Expression throughout Aging Alters Gene Expression Profiles in Murine Long-Term Hematopoietic Stem Cells

PubMed Central

Bennett, John A.; Singh, Kameshwar P.; Unnisa, Zeenath; Welle, Stephen L.; Gasiewicz, Thomas A.

2015-01-01

Dysregulation of hematopoietic stem cell (HSC) signaling can contribute to the development of diseases of the blood system. Lack of aryl hydrocarbon receptor (AhR) has been associated with alterations in gene expression related to HSC function and the subsequent development of a myeloproliferative disorder in aging female mice. We sorted the most primitive population of HSCs with the highest stem cell potential (Long-term, or LT-HSCs) from 18-month-old AhR-null-allele (AhR-KO) and WT mice and analyzed gene expression using microarray to determine alterations in gene expression and cell signaling networks in HSCs that could potentially contribute to the aging phenotype of AhR-KO mice. Comparisons with previous array data from 8-week old mice indicated that aging alone is sufficient to alter gene expression. In addition, a significant number of gene expression differences were observed in aged LT-HSCs that are dependent on both aging and lack of AhR. Pathway analysis of these genes revealed networks related to hematopoietic stem cell activity or function. qPCR was used to confirm the differential expression of a subset of these genes, focusing on genes that may represent novel AhR targets due to the presence of a putative AhR binding site in their upstream regulatory region. We verified differential expression of PDGF-D, Smo, Wdfy1, Zbtb37 and Zfp382. Pathway analysis of this subset of genes revealed overlap between cellular functions of the novel AhR targets and AhR itself. Lentiviral-mediated knockdown of AhR in lineage-negative hematopoietic cells was sufficient to induce changes in all five of the candidate AhR targets identified. Taken together, these data suggest a role for AhR in HSC functional regulation, and identify novel HSC AhR target genes that may contribute to the phenotypes observed in AhR-KO mice. PMID:26208102

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustafsson, Karin; Heffner, Garrett; Wenzel, Pamela L.

The widely expressed adaptor protein Shb has previously been reported to contribute to T cell function due to its association with the T cell receptor and furthermore, several of Shb's known interaction partners are established regulators of blood cell development and function. In addition, Shb deficient embryonic stem cells displayed reduced blood cell colony formation upon differentiation in vitro. The aim of the current study was therefore to explore hematopoietic stem and progenitor cell function in the Shb knockout mouse. Shb deficient bone marrow contained reduced relative numbers of long-term hematopoietic stem cells (LT-HSCs) that exhibited lower proliferation rates. Despitemore » this, Shb knockout LT-HSCs responded promptly by entering the cell cycle in response to genotoxic stress by 5-fluorouracil treatment. In competitive LT-HSC transplantations, Shb null cells initially engrafted as well as the wild-type cells but provided less myeloid expansion over time. Moreover, Shb knockout bone marrow cells exhibited elevated basal activities of focal adhesion kinase/Rac1/p21-activated kinase signaling and reduced responsiveness to Stem Cell Factor stimulation. Consequently, treatment with a focal adhesion kinase inhibitor increased Shb knockout LT-HSC proliferation. The altered signaling characteristics thus provide a plausible mechanistic explanation for the changes in LT-HSC proliferation since these signaling intermediates have all been shown to participate in LT-HSC cell cycle control. In summary, the loss of Shb dependent signaling in bone marrow cells, resulting in elevated focal adhesion kinase activity and reduced proliferative responses in LT-HSCs under steady state hematopoiesis, confers a disadvantage to the maintenance of LT-HSCs over time. -- Highlights: • Shb is an adaptor protein operating downstream of tyrosine kinase receptors. • Shb deficiency reduces hematopoietic stem cell proliferation. • The proliferative effect of Shb occurs via increased focal adhesion kinase activity. • Shb is critical for the long-term maintenance of the hematopoietic stem cell pool.« less

[Prokaryotic Expression and Purification of the Notch Ligand and Its Effect on Hematopoiesis after Carbon Tetrachloride Damage].

PubMed

Chen, Juan-Juan; Huang, Si-Yong; Ma, Peng-Fei; Wu, Bi-Jia; Zhou, Si-Lang; Zhao, Yong-Xing; Gong, Jun-Mei; Liang, Ying-Min

2018-04-01

To express and purify the mouse endothelial cell-targeted recombinant Notch ligand protein mD1R, and to investigate its effect on hematopoiesis after carbon tetrachloride damage. PCR was performed to clone and construct the expression vector pET22b(+)-mD1R. The mD1R successfully transformed into E. coli was induced by IPTG, and purified with Ni 2+ -beads affinity chromatography. The target protein was detected by SDS-PAGE. The fluorescence-activated cell sorting analysis (FACS), cell adhesion test, immunofluorescence staining and quantitative real-time PCR were employed to detect the endothelial cell-targeted and Notch signaling-activated biological characteristics of mD1R. The carbon tetrachloride mouse model was established to observe the effects of mD1R on the hematopoietic stem cell (HSC), myeloid cells and lymphoid cells by flow cytometry. The Lin - Scal-1 + c-Kit + cells were sorted by magnetic bead, FACS was performed to analyze the cell cycle, and RT-PCR was employed to observe the expression of interleukin (IL)-10. The prokaryotic expression vector was successfully cloned and constructed. The purity and the activity were confirmed in mD1R recombinant protein. The purified mD1R activated the Notch signaling pathway of hematopoietic stem cells in carbon tetrachloride damaged mouse, and internally elevated the number of HSC and long-term HSC to 2.96-fold and 6.18-fold. In addition, mD1R improved the amplification of the myeloid progenitor cells and the myeloid-derived suppressor cells, particularly the granulocyte/monocyte into blood. Mechanistically, the further analyses suggested that Notch pathway could increase the proliferation of HSC and enhance expression of IL-10 after stress injury. A new and activated recombinant Notch ligand protein has been obtained successfully to communicate hematopoietic stem cells and hematopoietic microenvironment. The Notch- mediated intrinsic hematopoiesis has been regulated by the anti-inflammatory factor after stress injury.

Effect of Mutation Order on Myeloproliferative Neoplasms

PubMed Central

Nangalia, Jyoti; Silber, Yvonne; Wedge, David C.; Grinfeld, Jacob; Baxter, E. Joanna; Massie, Charles E.; Papaemmanuil, Elli; Menon, Suraj; Godfrey, Anna L.; Dimitropoulou, Danai; Guglielmelli, Paola; Bellosillo, Beatriz; Besses, Carles; Döhner, Konstanze; Harrison, Claire N.; Vassiliou, George S.; Vannucchi, Alessandro; Campbell, Peter J.; Green, Anthony R.

2015-01-01

BACKGROUND Cancers result from the accumulation of somatic mutations, and their properties are thought to reflect the sum of these mutations. However, little is known about the effect of the order in which mutations are acquired. METHODS We determined mutation order in patients with myeloproliferative neoplasms by genotyping hematopoietic colonies or by means of next-generation sequencing. Stem cells and progenitor cells were isolated to study the effect of mutation order on mature and immature hematopoietic cells. RESULTS The age at which a patient presented with a myeloproliferative neoplasm, acquisition of JAK2 V617F homozygosity, and the balance of immature progenitors were all influenced by mutation order. As compared with patients in whom the TET2 mutation was acquired first (hereafter referred to as “TET2-first patients”), patients in whom the Janus kinase 2 (JAK2) mutation was acquired first (“JAK2-first patients”) had a greater likelihood of presenting with polycythemia vera than with essential thrombocythemia, an increased risk of thrombosis, and an increased sensitivity of JAK2-mutant progenitors to ruxolitinib in vitro. Mutation order influenced the proliferative response to JAK2 V617F and the capacity of double-mutant hematopoietic cells and progenitor cells to generate colony-forming cells. Moreover, the hematopoietic stem-and-progenitor-cell compartment was dominated by TET2 single-mutant cells in TET2-first patients but by JAK2–TET2 double-mutant cells in JAK2-first patients. Prior mutation of TET2 altered the transcriptional consequences of JAK2 V617F in a cell-intrinsic manner and prevented JAK2 V617F from up-regulating genes associated with proliferation. CONCLUSIONS The order in which JAK2 and TET2 mutations were acquired influenced clinical features, the response to targeted therapy, the biology of stem and progenitor cells, and clonal evolution in patients with myeloproliferative neoplasms. (Funded by Leukemia and Lymphoma Research and others.) PMID:25671252

[Clinical significance of autologous transplantation with hematopoietic stem cells in leukemia and solid tumors].

PubMed

Hinterberger, W; Adler, V; Bauer, K; Haberhauer, G; Habertheuer, K H; Höniger, S; Huber, K; Kier, P; Kittel, E; Ruckser, R

1995-01-01

Autologous Transplantation of hematopoietic tissue with frozen hematopoietic stem cells is increasingly used for leukemias and lymphomas, but also for some solid tumors. In the past, autotransplants have been performed with bone marrow as the source of hematopoietic stem cells. Circulating, blood derived hematopoietic stem cells, however, allow safe engraftment of all cell lines after supralethal chemo-radiotherapy. This survey describes the role of autologous stem cell transplantation in disorders that are currently in the center of clinical and scientific interest. This estimation is based on the proportion of protocols dealing with, and centering on, autologous stem cell transplantation in the context of treatment for leukemias and solid tumors ("Oncodisc", "PDQ").

Inhibiting glycogen synthase kinase-3 mitigates the hematopoietic acute radiation syndrome in mice.

PubMed

Lee, Chang-Lung; Lento, William E; Castle, Katherine D; Chao, Nelson J; Kirsch, David G

2014-05-01

Exposure to a nuclear accident or radiological attack can cause death from acute radiation syndrome (ARS), which results from radiation injury to vital organs such as the hematopoietic system. However, the U.S. Food and Drug Administration (FDA) has not approved any medical countermeasures for this specific purpose. With growing concern over nuclear terrorism, there is an urgent need to develop small molecule deliverables that mitigate mortality from ARS. One emerging modulator of hematopoietic stem/progenitor cell (HSPC) activity is glycogen synthase kinase-3 (GSK-3). The inhibition of GSK-3 has been shown to augment hematopoietic repopulation in mouse models of bone marrow transplantation. In this study, we performed an in vitro screen using irradiated bone marrow mononuclear cells (BM-MNCs) to test the effects of four GSK-3 inhibitors: CHIR99021; 6-Bromoindirubin-3'-oxime (BIO); SB415286; and SB216763. This screen showed that SB216763 significantly increased the frequency of c-Kit(+) Lin(-) Sca1(+) (KLS) cells and hematopoietic colony-forming cells in irradiated BM-MNCs. Importantly, administration of a single dose of SB216763 to C57BL/6J mice by subcutaneous injection 24 h after total-body irradiation significantly improved hematopoietic recovery and mitigated hematopoietic ARS. Collectively, our results demonstrate that the GSK-3 inhibitor SB216763 is an effective medical countermeasure against acute radiation injury of the hematopoietic system.

Endothelial transplantation rejuvenates aged hematopoietic stem cell function

PubMed Central

Poulos, Michael G.; Gutkin, Michael C.; Llanos, Pierre; Gilleran, Katherine; Rabbany, Sina Y.; Butler, Jason M.

2017-01-01

Age-related changes in the hematopoietic compartment are primarily attributed to cell-intrinsic alterations in hematopoietic stem cells (HSCs); however, the contribution of the aged microenvironment has not been adequately evaluated. Understanding the role of the bone marrow (BM) microenvironment in supporting HSC function may prove to be beneficial in treating age-related functional hematopoietic decline. Here, we determined that aging of endothelial cells (ECs), a critical component of the BM microenvironment, was sufficient to drive hematopoietic aging phenotypes in young HSCs. We used an ex vivo hematopoietic stem and progenitor cell/EC (HSPC/EC) coculture system as well as in vivo EC infusions following myelosuppressive injury in mice to demonstrate that aged ECs impair the repopulating activity of young HSCs and impart a myeloid bias. Conversely, young ECs restored the repopulating capacity of aged HSCs but were unable to reverse the intrinsic myeloid bias. Infusion of young, HSC-supportive BM ECs enhanced hematopoietic recovery following myelosuppressive injury and restored endogenous HSC function in aged mice. Coinfusion of young ECs augmented aged HSC engraftment and enhanced overall survival in lethally irradiated mice by mitigating damage to the BM vascular microenvironment. These data lay the groundwork for the exploration of EC therapies that can serve as adjuvant modalities to enhance HSC engraftment and accelerate hematopoietic recovery in the elderly population following myelosuppressive regimens. PMID:29035282

Pleiotrophin mediates hematopoietic regeneration via activation of RAS

PubMed Central

Himburg, Heather A.; Yan, Xiao; Doan, Phuong L.; Quarmyne, Mamle; Micewicz, Eva; McBride, William; Chao, Nelson J.; Slamon, Dennis J.; Chute, John P.

2014-01-01

Hematopoietic stem cells (HSCs) are highly susceptible to ionizing radiation–mediated death via induction of ROS, DNA double-strand breaks, and apoptotic pathways. The development of therapeutics capable of mitigating ionizing radiation–induced hematopoietic toxicity could benefit both victims of acute radiation sickness and patients undergoing hematopoietic cell transplantation. Unfortunately, therapies capable of accelerating hematopoietic reconstitution following lethal radiation exposure have remained elusive. Here, we found that systemic administration of pleiotrophin (PTN), a protein that is secreted by BM-derived endothelial cells, substantially increased the survival of mice following radiation exposure and after myeloablative BM transplantation. In both models, PTN increased survival by accelerating the recovery of BM hematopoietic stem and progenitor cells in vivo. PTN treatment promoted HSC regeneration via activation of the RAS pathway in mice that expressed protein tyrosine phosphatase receptor-zeta (PTPRZ), whereas PTN treatment did not induce RAS signaling in PTPRZ-deficient mice, suggesting that PTN-mediated activation of RAS was dependent upon signaling through PTPRZ. PTN strongly inhibited HSC cycling following irradiation, whereas RAS inhibition abrogated PTN-mediated induction of HSC quiescence, blocked PTN-mediated recovery of hematopoietic stem and progenitor cells, and abolished PTN-mediated survival of irradiated mice. These studies demonstrate the therapeutic potential of PTN to improve survival after myeloablation and suggest that PTN-mediated hematopoietic regeneration occurs in a RAS-dependent manner. PMID:25250571

Vascular Endothelial Growth Factor and Angiopoietin-1 Stimulate Postnatal Hematopoiesis by Recruitment of Vasculogenic and Hematopoietic Stem Cells

PubMed Central

Hattori, Koichi; Dias, Sergio; Heissig, Beate; Hackett, Neil R.; Lyden, David; Tateno, Masatoshi; Hicklin, Daniel J.; Zhu, Zhenping; Witte, Larry; Crystal, Ronald G.; Moore, Malcolm A.S.; Rafii, Shahin

2001-01-01

Tyrosine kinase receptors for angiogenic factors vascular endothelial growth factor (VEGF) and angiopoietin-1 (Ang-1) are expressed not only by endothelial cells but also by subsets of hematopoietic stem cells (HSCs). To further define their role in the regulation of postnatal hematopoiesis and vasculogenesis, VEGF and Ang-1 plasma levels were elevated by injecting recombinant protein or adenoviral vectors expressing soluble VEGF165, matrix-bound VEGF189, or Ang-1 into mice. VEGF165, but not VEGF189, induced a rapid mobilization of HSCs and VEGF receptor (VEGFR)2+ circulating endothelial precursor cells (CEPs). In contrast, Ang-1 induced delayed mobilization of CEPs and HSCs. Combined sustained elevation of Ang-1 and VEGF165 was associated with an induction of hematopoiesis and increased marrow cellularity followed by proliferation of capillaries and expansion of sinusoidal space. Concomitant to this vascular remodeling, there was a transient depletion of hematopoietic activity in the marrow, which was compensated by an increase in mobilization and recruitment of HSCs and CEPs to the spleen resulting in splenomegaly. Neutralizing monoclonal antibody to VEGFR2 completely inhibited VEGF165, but not Ang-1–induced mobilization and splenomegaly. These data suggest that temporal and regional activation of VEGF/VEGFR2 and Ang-1/Tie-2 signaling pathways are critical for mobilization and recruitment of HSCs and CEPs and may play a role in the physiology of postnatal angiogenesis and hematopoiesis. PMID:11342585

Zinc finger protein 521 antagonizes early B-cell factor 1 and modulates the B-lymphoid differentiation of primary hematopoietic progenitors.

PubMed

Mega, Tiziana; Lupia, Michela; Amodio, Nicola; Horton, Sarah J; Mesuraca, Maria; Pelaggi, Daniela; Agosti, Valter; Grieco, Michele; Chiarella, Emanuela; Spina, Raffaella; Moore, Malcolm A S; Schuringa, Jan Jacob; Bond, Heather M; Morrone, Giovanni

2011-07-01

Zinc finger protein 521 (EHZF/ZNF521) is a multi-functional transcription co-factor containing 30 zinc fingers and an amino-terminal motif that binds to the nucleosome remodelling and histone deacetylase (NuRD) complex. ZNF521 is believed to be a relevant player in the regulation of the homeostasis of the hematopoietic stem/progenitor cell compartment, however the underlying molecular mechanisms are still largely unknown. Here, we show that this protein plays an important role in the control of B-cell development by inhibiting the activity of early B-cell factor-1 (EBF1), a master factor in B-lineage specification. In particular, our data demonstrate that: (1) ZNF521 binds to EBF1 via its carboxyl-terminal portion and this interaction is required for EBF1 inhibition; (2) NuRD complex recruitment by ZNF521 is not essential for the inhibition of transactivation of EBF1-dependent promoters; (3) ZNF521 represses EBF1 target genes in a human B-lymphoid molecular context; and (4) RNAi-mediated silencing of ZNF521/Zfp521 in primary human and murine hematopoietic progenitors strongly enhances the generation of B-lymphocytes in vitro. Taken together, our data indicate that ZNF521 can antagonize B-cell development and lend support to the notion that it may contribute to conserve the multipotency of primitive lympho-myeloid progenitors by preventing or delaying their EBF1-driven commitment toward the B-cell lineage.

Changes in human bone marrow fat content associated with changes in hematopoietic stem cell numbers and cytokine levels with aging

PubMed Central

Tuljapurkar, Sonal R; McGuire, Timothy R; Brusnahan, Susan K; Jackson, John D; Garvin, Kevin L; Kessinger, Margaret A; Lane, Judy T; O' Kane, Barbara J; Sharp, John G

2011-01-01

Hematological deficiencies increase with aging, including anemias, reduced responses to hematopoietic stress and myelodysplasias. This investigation tested the hypothesis that increased bone marrow (BM) fat content in humans with age was associated with decreased numbers of side population (SP) hematopoietic stem cells, and this decrease correlated with changes in cytokine levels. BM was obtained from the femoral head and trochanteric region of the femur removed at surgery for total hip replacement (N = 100 subjects). In addition, BM from cadavers (N = 36), with no evidence of hip disease, was evaluated for fat content. Whole trabecular marrow samples were ground in a sterile mortar and pestle, and cellularity and lipid content determined. Marrow cells were stained with Hoechst dye and SP profiles were acquired. Plasma levels of insulin-like growth factor (IGF)-1, stromal-derived factor (SDF)-1 and interleukin (IL)-6 were measured using ELISA. Fat content in the BM of human subjects and cadavers increased with age. The numbers of SP stem cells in BM as well as plasma IGF-1 and SDF-1 levels decreased in correlation with increased BM fat. IL-6 had no relationship to changes in marrow fat. These data suggest that increased BM fat may be associated with a decreased number of SP stem cells and IGF-1 and SDF-1 levels with aging. These data further raise a more general question as to the role of adipose cells in the regulation of tissue stem cells. PMID:21923862

Protective Effects of 2-Amino-5,6-dihydro-4H-1,3-thiazine and Its Derivative against Radiation-Induced Hematopoietic and Intestinal Injury in Mice.

PubMed

Li, Yuanyuan; Kong, Shaofan; Yang, Fujun; Xu, Wenqing

2018-05-21

Ionizing radiation (IR) acts as an external stimulating factor, when it acts on the body, it will activate NF- κ B and cause the up-regulation of inducible nitric oxide synthase (iNOS) and induce a large amount of nitric oxide (NO) production. NO and other reactive nitrogen and oxygen species (RNS and ROS) can cause damage to biological molecules and affect their physiological functions. Our study investigated the protective role of 2-amino-5,6-dihydro-4 H -1,3-thiazine hydrobromide (2-ADT) and 2-acetylamino-5,6-dihydro-4 H -1,3-thiazine hydrobromide (2-AADT), two nitric oxide synthase inhibitors, against radiation-induced hematopoietic and intestinal injury in mice. Pretreatment with 2-ADT and 2-AADT improved the survival of mice exposed to a lethal dose of radiation, especially, the survival rate of the 2-ADT 20 mg/kg group was significantly higher than that of the vehicle group ( p < 0.001). Our findings indicated that the radioprotective actions of 2-ADT and 2-AADT are achieved via accelerating hematopoietic system recovery, decreasing oxidative and nitrosative stress by enhancing the antioxidant defense system and reducing NO as well as peroxynitrite (ONOO − ) content, and mitigating the radiation-induced DNA damage evaluated by comet assay. These results suggest that 2-ADT and 2-AADT may have great application potential in ameliorating the damages of radiotherapy.

A small interfering RNA targeting Lnk accelerates bone fracture healing with early neovascularization.

PubMed

Kawakami, Yohei; Ii, Masaaki; Matsumoto, Tomoyuki; Kawamoto, Atsuhiko; Kuroda, Ryosuke; Akimaru, Hiroshi; Mifune, Yutaka; Shoji, Taro; Fukui, Tomoaki; Asahi, Michio; Kurosaka, Masahiro; Asahara, Takayuki

2013-09-01

Lnk, an intracellular adapter protein, is expressed in hematopoietic cell lineages, which has recently been proved as an essential inhibitory signaling molecule for stem cell self-renewal in the stem cell factor-c-Kit signaling pathway with enhanced hematopoietic and osteogenic reconstitution in Lnk-deficient mice. Moreover, the therapeutic potential of hematopoietic stem/endothelial progenitor cells (EPCs) for fracture healing has been demonstrated with mechanistic insight into vasculogenesis/angiogenesis and osteogenesis enhancement in the fracture sites. We report here, Lnk siRNA-transfected endothelial commitment of c-kit+/Sca-1+/lineage- subpopulations of bone marrow cells have high EPC colony-forming capacity exhibiting endothelial markers, VE-Cad, VEGF and Ang-1. Lnk siRNA-transfected osteoblasts also show highly osteoblastic capacity. In vivo, locally transfected Lnk siRNA could successfully downregulate the expression of Lnk at the fracture site up to 1 week, and radiological and histological examination showed extremely accelerated fracture healing in Lnk siRNA-transfected mice. Moreover, Lnk siRNA-transfected mice exhibited sufficient therapeutic outcomes with intrinstic enhancement of angiogenesis and osteogenesis, specifically, the mice demonstrated better blood flow recovery in the sites of fracture. In our series of experiments, we clarified that a negatively regulated Lnk system contributed to a favorable circumstance for fracture healing by enhancing vasculogenesis/angiogenesis and osteogenesis. These findings suggest that downregulation of Lnk system may have the clinical potential for faster fracture healing, which contributes to the reduction of delayed unions or non-unions.

Purinergic Receptors in Quiescence and Localization of Leukemic Stem Cells

DTIC Science & Technology

2011-05-01

2011. Ewing’s Sarcoma Gene EWS regulates Hematopoietic Stem Cell Senescence. Blood, 117:1156-66. Conclusion How leukemia stem cells gained...findings contained in this report are those of the author( s ) and should not be construed as an official Department of the Army position, policy or...Receptors in Quiescence and Localization of Leukemic Stem Cells 5b. GRANT NUMBER W81XWH-09-1-0364 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) 5d

Identification of the Microtubule-Inhibitor Activated Bcl-xL Kinase: A Regulator of Breast Cancer Cell Chemosensitivity to Taxol

DTIC Science & Technology

2011-08-01

not shown). 1 5 Translational research study We continued the clinical protocol entitled “Alterations in the Bcl-2 Family Proteins...Bcl- 2 protein phosphorylation in hematopoietic cells may be more likely to have fever, neutropenia than others, for example. While effective...Alterations in the Bcl-2 Family Proteins in the Peripheral Blood Following Treatment with Taxanes in Patients with Breast Cancer.” Accepted by the UAMS

Identification of a role for the nuclear receptor EAR-2 in the maintenance of clonogenic status within the leukemia cell hierarchy

PubMed Central

Ichim, CV; Atkins, HL; Iscove, NN; Wells, RA

2016-01-01

Identification of genes that regulate clonogenicity of acute myelogenous leukemia (AML) cells is hindered by the difficulty of isolating pure populations of cells with defined proliferative abilities. By analyzing the growth of clonal siblings in low passage cultures of the cell line OCI/AML4 we resolved this heterogeneous population into strata of distinct clonogenic potential, permitting analysis of the transcriptional signature of single cells with defined proliferative abilities. By microarray analysis we showed that the expression of the orphan nuclear receptor EAR-2 (NR2F6) is greater in leukemia cells with extensive proliferative capacity than in those that have lost proliferative ability. EAR-2 is expressed highly in long-term hematopoietic stem cells, relative to short-term hematopoietic stem and progenitor cells, and is downregulated in AML cells after induction of differentiation. Exogenous expression of EAR-2 increased the growth of U937 cells and prevented the proliferative arrest associated with terminal differentiation, and blocked differentiation of U937 and 32Dcl3 cells. Conversely, silencing of EAR-2 by short-hairpin RNA initiated terminal differentiation of these cell lines. These data identify EAR-2 as an important factor in the regulation of clonogenicity and differentiation, and establish that analysis of clonal siblings allows the elucidation of differences in gene expression within the AML hierarchy. PMID:21637284

Notch Signaling and Alloreactivity.

PubMed

Radojcic, Vedran; Maillard, Ivan

2016-12-01

Solid organ and allogeneic hematopoietic cell transplantation have become standard therapeutic interventions that save patient lives and improve quality of life. Our enhanced understanding of transplantation immunobiology has refined clinical management and improved outcomes. However, organ rejection and graft-versus-host disease remain major obstacles to the broader successful application of these therapeutic procedures. Notch signaling regulates multiple aspects of adaptive and innate immunity. Preclinical studies identified Notch signaling as a promising target in autoimmune diseases, as well as after allogeneic hematopoietic cell and solid organ transplantation. Notch was found to be a central regulator of alloreactivity across clinically relevant models of transplantation. Notch inhibition in T cells prevented graft-versus-host disease and organ rejection, establishing organ tolerance by skewing CD4 T helper polarization away from a proinflammatory response toward suppressive regulatory T cells. Notch ligand blockade also dampened alloantibody deposition and prevented chronic rejection through humoral mechanisms. Toxicities of systemic Notch blockade were observed with γ-secretase inhibitors in preclinical and early clinical trials across different indications, but they did not arise upon preclinical targeting of Delta-like Notch ligands, a strategy sufficient to confer full benefits of Notch ablation in T cell alloimmunity. Because multiple clinical grade reagents have been developed to target individual Notch ligands and receptors, the benefits of Notch blockade in transplantation are calling for translation of preclinical findings into human transplantation medicine.

Comprehensive gene expression profiling following DNA vaccination of rainbow trout against infectious hematopoietic necrosis virus

USGS Publications Warehouse

Purcell, Maureen K.; Nichols, Krista M.; Winton, James R.; Kurath, Gael; Thorgaard, Gary H.; Wheeler, Paul; Hansen, John D.; Herwig, Russell P.; Park, Linda K.

2006-01-01

The DNA vaccine based on the glycoprotein gene of Infectious hematopoietic necrosis virus induces a non-specific anti-viral immune response and long-term specific immunity against IHNV. This study characterized gene expression responses associated with the early anti-viral response. Homozygous rainbow trout were injected intra-muscularly (I.M.) with vector DNA or the IHNV DNA vaccine. Gene expression in muscle tissue (I.M. site) was evaluated using a 16,008 feature salmon cDNA microarray. Eighty different genes were significantly modulated in the vector DNA group while 910 genes were modulated in the IHNV DNA vaccinate group relative to control group. Quantitative reverse-transcriptase PCR was used to examine expression of selected immune genes at the I.M. site and in other secondary tissues. In the localized response (I.M. site), the magnitudes of gene expression changes were much greater in the vaccinate group relative to the vector DNA group for the majority of genes analyzed. At secondary systemic sites (e.g. gill, kidney and spleen), type I IFN-related genes were up-regulated in only the IHNV DNA vaccinated group. The results presented here suggest that the IHNV DNA vaccine induces up-regulation of the type I IFN system across multiple tissues, which is the functional basis of early anti-viral immunity.

Dnmt1 regulates the myogenic lineage specification of muscle stem cells.

PubMed

Liu, Renjing; Kim, Kun-Yong; Jung, Yong-Wook; Park, In-Hyun

2016-10-18

DNA methylation is an important epigenetic mark that regulates gene expression. Dnmt1 plays an important role in maintaining DNA methylation patterns on daughter DNA strands. Studies have shed light into the functional role of Dnmt1 regulation in the hematopoietic and epidermal systems. Here we show that Dnmt1 is required for myogenesis. Loss of Dnmt1 results in reduced expression of myogenic genes and defects in myogenic differentiation. We have utilized a conditional knockout mouse approach to examine the functional consequences of Dnmt1 depletion specifically in the developing muscle. These mice were born runted, with smaller body weights, and reduced ability to form myotubes in vitro. We show that expression of Id-1, a negative regulator of myogenesis, is enhanced in Dnmt1-deficient cultures, leading to enhanced transdifferentiation of myoblasts toward the osteogenic lineage. Thus, these studies demonstrate that Dnmt1 influences cellular identity and determines lineage fidelity.

Dnmt1 regulates the myogenic lineage specification of muscle stem cells

PubMed Central

Liu, Renjing; Kim, Kun-Yong; Jung, Yong-Wook; Park, In-Hyun

2016-01-01

DNA methylation is an important epigenetic mark that regulates gene expression. Dnmt1 plays an important role in maintaining DNA methylation patterns on daughter DNA strands. Studies have shed light into the functional role of Dnmt1 regulation in the hematopoietic and epidermal systems. Here we show that Dnmt1 is required for myogenesis. Loss of Dnmt1 results in reduced expression of myogenic genes and defects in myogenic differentiation. We have utilized a conditional knockout mouse approach to examine the functional consequences of Dnmt1 depletion specifically in the developing muscle. These mice were born runted, with smaller body weights, and reduced ability to form myotubes in vitro. We show that expression of Id-1, a negative regulator of myogenesis, is enhanced in Dnmt1-deficient cultures, leading to enhanced transdifferentiation of myoblasts toward the osteogenic lineage. Thus, these studies demonstrate that Dnmt1 influences cellular identity and determines lineage fidelity. PMID:27752090

Hematopoietic tissue repair under chronic low daily dose irradiation

NASA Astrophysics Data System (ADS)

Seed, T. M.

The capacity of the hematopoietic system to repair constantly accruing cellular damage under chronic, low daily dose gamma irradiation is essential for the maintenance of a functional hematopoietic system, and, in turn, long term survival. In certain individuals, however, such continuous cycles of damage and repair provide an essential inductive environment for selected types of hematopathologies, e.g., myeloid leukemia (ML). In our laboratory we have been studying temporal and causal relationships between hematopoietic capacity, associated repair functions, and propensities for hematologic disease in canines under variable levels of chronic radiation stress (0.3-26.3 cGy d^-1). Results indicate that the maximum exposure rate tolerated by the hematopoietic system is highly individual-specific (three major responding subgroups identified) and is based largely on the degree to which repair capacity, and, in turn, hematopoietic restoration, is augmented under chronic exposure. In low-tolerance individuals (prone to aplastic anemia, subgroup 1), the failure to augment basic repair functions seemingly results in a progressive accumulation of genetic and cellular damage within vital progenitorial marrow compartments (particularly marked within erythroid compartments) that results in loss of reproductive capacity and ultimately in collapse of the hematopoietic system. The high-tolerance individuals (radioaccommodated and either prone- or not prone to ML, subgroup 2 & 3) appear to minimize the accumulating damage effect of daily exposures by extending repair functions, which preserves reproductive integrity and fosters regenerative hematopoietic responses. As the strength of the regenerative response manifests the extent of repair augmentation, the relatively strong response of high-tolerance individuals progressing to patent ML suggests an insufficiency of repair quality rather than repair quantity. The kinetics of these repair-mediated, regenerative hematopoietic responses within the major subgroups are under study and should provide useful insights into the nature of hematopoietic accommodation (or its failure) under greatly extended periods of chronic, low-daily-dose ionizing radiation exposure.

In vivo engineering of bone tissues with hematopoietic functions and mixed chimerism

PubMed Central

Shih, Yu-Ru; Kang, Heemin; Rao, Vikram; Chiu, Yu-Jui; Kwon, Seong Keun; Varghese, Shyni

2017-01-01

Synthetic biomimetic matrices with osteoconductivity and osteoinductivity have been developed to regenerate bone tissues. However, whether such systems harbor donor marrow in vivo and support mixed chimerism remains unknown. We devised a strategy to engineer bone tissues with a functional bone marrow (BM) compartment in vivo by using a synthetic biomaterial with spatially differing cues. Specifically, we have developed a synthetic matrix recapitulating the dual-compartment structures by modular assembly of mineralized and nonmineralized macroporous structures. Our results show that these matrices incorporated with BM cells or BM flush transplanted into recipient mice matured into functional bone displaying the cardinal features of both skeletal and hematopoietic compartments similar to native bone tissue. The hematopoietic function of bone tissues was demonstrated by its support for a higher percentage of mixed chimerism compared with i.v. injection and donor hematopoietic cell mobilization in the circulation of nonirradiated recipients. Furthermore, hematopoietic cells sorted from the engineered bone tissues reconstituted the hematopoietic system when transplanted into lethally irradiated secondary recipients. Such engineered bone tissues could potentially be used as ectopic BM surrogates for treatment of nonmalignant BM diseases and as a tool to study hematopoiesis, donor–host cell dynamics, tumor tropism, and hematopoietic cell transplantation. PMID:28484009

In vivo engineering of bone tissues with hematopoietic functions and mixed chimerism.

PubMed

Shih, Yu-Ru; Kang, Heemin; Rao, Vikram; Chiu, Yu-Jui; Kwon, Seong Keun; Varghese, Shyni

2017-05-23

Synthetic biomimetic matrices with osteoconductivity and osteoinductivity have been developed to regenerate bone tissues. However, whether such systems harbor donor marrow in vivo and support mixed chimerism remains unknown. We devised a strategy to engineer bone tissues with a functional bone marrow (BM) compartment in vivo by using a synthetic biomaterial with spatially differing cues. Specifically, we have developed a synthetic matrix recapitulating the dual-compartment structures by modular assembly of mineralized and nonmineralized macroporous structures. Our results show that these matrices incorporated with BM cells or BM flush transplanted into recipient mice matured into functional bone displaying the cardinal features of both skeletal and hematopoietic compartments similar to native bone tissue. The hematopoietic function of bone tissues was demonstrated by its support for a higher percentage of mixed chimerism compared with i.v. injection and donor hematopoietic cell mobilization in the circulation of nonirradiated recipients. Furthermore, hematopoietic cells sorted from the engineered bone tissues reconstituted the hematopoietic system when transplanted into lethally irradiated secondary recipients. Such engineered bone tissues could potentially be used as ectopic BM surrogates for treatment of nonmalignant BM diseases and as a tool to study hematopoiesis, donor-host cell dynamics, tumor tropism, and hematopoietic cell transplantation.

An Analysis of microRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells

DTIC Science & Technology

2014-08-01

AWARD NUMBER: W81XWH-13-1-0082 TITLE: An Analysis of microRNA Expression in the Myelodysplastic Syndromes Using Hematopoietic Stem Cells ... Hematopoietic Stem Cells 5b. GRANT NUMBER W81XWH-13-1-0082 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Dr. Stephen Chung 5e. TASK...in MDS hematopoietic stem cells (MDS HSCs) as compared with normal HSCs. MiRNAs differentially expressed between MDS HSCs and normal HSCs overlapped

Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model

PubMed Central

Santiago-Osorio, Edelmiro; Ledesma-Martínez, Edgar; Aguiñiga-Sánchez, Itzen; Poblano-Pérez, Ignacio; Weiss-Steider, Benny; Montesinos-Montesinos, Juan José; de Lourdes Mora-García, María

2015-01-01

Background Hematopoietic stem cells transplantation has high clinical potential against a wide variety of hematologic, metabolic, and autoimmune diseases and solid tumors. Clinically, hematopoietic stem cells derived from peripheral blood are currently used more than those obtained from sources such as bone marrow. However, mobilizing agents used in the clinic tend to fail in high rates, making the number of mobilized cells insufficient for transplantation. We investigated whether sodium caseinate induces functional mobilization of hematopoietic stem cells into peripheral blood of Balb/c mice. Material/Methods Using a mouse model, we administrated sodium caseinate or Plerixafor, a commercial mobilizing agent, and analyzed counts of hematopoietic stem cells in peripheral blood, and then cells were transplanted into lethally irradiated mice to restore hematopoiesis. All assays were performed at least twice. Results We found that sodium caseinate increases the number of mononuclear cells in peripheral blood with the immunophenotype of hematopoietic stem cells (0.2 to 0.5% LSK cells), allowing them to form colonies of various cell lineages in semisolid medium (p<0.05). This effect is similar to that of Plerixafor, and cells transplanted into lethally irradiated mice can restore hematopoiesis at higher percentages than mononuclear cells mobilized by Plerixafor (40% vs. 20%, respectively). Further, a secondary transplant rescued a separate group of irradiated mice from death, proving definitive evidence of hematopoietic reconstitution after hematopoietic stem cells transplantation. Data are presented as mean ± standard deviation. To determine significant differences between the data, one-way ANOVA and the Tukey test were used. Conclusions Collectively these results show the utility of sodium caseinate as a mobilizer of hematopoietic stem cells and its potential clinical application in transplantation settings. PMID:26409928

Thrombopoietin contributes to the formation and the maintenance of hematopoietic progenitor-containing cell clusters in the aorta-gonad-mesonephros region.

PubMed

Harada, Kaho; Nobuhisa, Ikuo; Anani, Maha; Saito, Kiyoka; Taga, Tetsuya

2017-07-01

In the midgestation mouse embryo, hematopoietic cell clusters containing hematopoietic stem/progenitor cells arise in the aorta-gonad-mesonephros (AGM) region. We have previously reported that forced expression of the Sox17 transcription factor in CD45 low c-Kit high AGM cells, which are the hematopoietic cellular component of the cell clusters, and subsequent coculture with OP9 stromal cells in the presence of three cytokines, stem cell factor (SCF), interleukin-3 (IL-3), and thrombopoietin (TPO), led to the formation and the maintenance of cell clusters with cells at an undifferentiated state in vitro. In this study, we investigated the role of each cytokine in the formation of hematopoietic cell clusters. We cultured Sox17-transduced AGM cells with each of the 7 possible combinations of the three cytokines. The size and the number of Sox17-transduced cell clusters in the presence of TPO, either alone or in combination, were comparable to that observed with the complete set of the three cytokines. Expression of TPO receptor, c-Mpl was almost ubiquitously expressed and maintained in Sox17-transduced hematopoietic cell clusters. In addition, the expression level of c-Mpl was highest in the CD45 low c-Kit high cells among the Sox17-transduced cell clusters. Moreover, c-Mpl protein was highly expressed in the intra-aortic hematopoietic cell clusters in comparison with endothelial cells of dorsal aorta. Finally, stimulation of the endothelial cells prepared from the AGM region by TPO induced the production of hematopoietic cells. These results suggest that TPO contributes to the formation and the maintenance of hematopoietic cell clusters in the AGM region. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model.

PubMed

Santiago-Osorio, Edelmiro; Ledesma-Martínez, Edgar; Aguiñiga-Sánchez, Itzen; Poblano-Pérez, Ignacio; Weiss-Steider, Benny; Montesinos-Montesinos, Juan José; Mora-García, María de Lourdes

2015-09-25

BACKGROUND Hematopoietic stem cells transplantation has high clinical potential against a wide variety of hematologic, metabolic, and autoimmune diseases and solid tumors. Clinically, hematopoietic stem cells derived from peripheral blood are currently used more than those obtained from sources such as bone marrow. However, mobilizing agents used in the clinic tend to fail in high rates, making the number of mobilized cells insufficient for transplantation. We investigated whether sodium caseinate induces functional mobilization of hematopoietic stem cells into peripheral blood of Balb/c mice. MATERIAL AND METHODS Using a mouse model, we administrated sodium caseinate or Plerixafor, a commercial mobilizing agent, and analyzed counts of hematopoietic stem cells in peripheral blood, and then cells were transplanted into lethally irradiated mice to restore hematopoiesis. All assays were performed at least twice. RESULTS We found that sodium caseinate increases the number of mononuclear cells in peripheral blood with the immunophenotype of hematopoietic stem cells (0.2 to 0.5% LSK cells), allowing them to form colonies of various cell lineages in semisolid medium (p<0.05). This effect is similar to that of Plerixafor, and cells transplanted into lethally irradiated mice can restore hematopoiesis at higher percentages than mononuclear cells mobilized by Plerixafor (40% vs. 20%, respectively). Further, a secondary transplant rescued a separate group of irradiated mice from death, proving definitive evidence of hematopoietic reconstitution after hematopoietic stem cells transplantation. Data are presented as mean ± standard deviation. To determine significant differences between the data, one-way ANOVA and the Tukey test were used. CONCLUSIONS Collectively these results show the utility of sodium caseinate as a mobilizer of hematopoietic stem cells and its potential clinical application in transplantation settings.

Nitric oxide/cGMP pathway signaling actively down-regulates α4β1-integrin affinity: an unexpected mechanism for inducing cell de-adhesion.

PubMed

Chigaev, Alexandre; Smagley, Yelena; Sklar, Larry A

2011-05-17

Integrin activation in response to inside-out signaling serves as the basis for rapid leukocyte arrest on endothelium, migration, and mobilization of immune cells. Integrin-dependent adhesion is controlled by the conformational state of the molecule, which is regulated by seven-transmembrane Guanine nucleotide binding Protein-Coupled Receptors (GPCRs). α4β1-integrin (CD49d/CD29, Very Late Antigen-4, VLA-4) is expressed on leukocytes, hematopoietic progenitors, stem cells, hematopoietic cancer cells, and others. VLA-4 conformation is rapidly up-regulated by inside-out signaling through Gαi-coupled GPCRs and down-regulated by Gαs-coupled GPCRs. However, other signaling pathways, which include nitric oxide-dependent signaling, have been implicated in the regulation of cell adhesion. The goal of the current report was to study the effect of nitric oxide/cGMP signaling pathway on VLA-4 conformational regulation. Using fluorescent ligand binding to evaluate the integrin activation state on live cells in real-time, we show that several small molecules, which specifically modulate nitric oxide/cGMP signaling pathway, as well as a cell permeable cGMP analog, can rapidly down-modulate binding of a VLA-4 specific ligand on cells pre-activated through three Gαi-coupled receptors: wild type CXCR4, CXCR2 (IL-8RB), and a non-desensitizing mutant of formyl peptide receptor (FPR ΔST). Upon signaling, we detected rapid changes in the ligand dissociation rate. The dissociation rate after inside-out integrin de-activation was similar to the rate for resting cells. In a VLA-4/VCAM-1-specific myeloid cell adhesion system, inhibition of the VLA-4 affinity change by nitric oxide had a statistically significant effect on real-time cell aggregation. We conclude that nitric oxide/cGMP signaling pathway can rapidly down-modulate the affinity state of the VLA-4 binding pocket, especially under the condition of sustained Gαi-coupled GPCR signaling, generated by a non-desensitizing receptor mutant. This suggests a fundamental role of this pathway in de-activation of integrin-dependent cell adhesion.

Targeting Leukemia Stem Cells in the Bone Marrow Niche

PubMed Central

Bornhäuser, Martin

2018-01-01

The bone marrow (BM) niche encompasses multiple cells of mesenchymal and hematopoietic origin and represents a unique microenvironment that is poised to maintain hematopoietic stem cells. In addition to its role as a primary lymphoid organ through the support of lymphoid development, the BM hosts various mature lymphoid cell types, including naïve T cells, memory T cells and plasma cells, as well as mature myeloid elements such as monocyte/macrophages and neutrophils, all of which are crucially important to control leukemia initiation and progression. The BM niche provides an attractive milieu for tumor cell colonization given its ability to provide signals which accelerate tumor cell proliferation and facilitate tumor cell survival. Cancer stem cells (CSCs) share phenotypic and functional features with normal counterparts from the tissue of origin of the tumor and can self-renew, differentiate and initiate tumor formation. CSCs possess a distinct immunological profile compared with the bulk population of tumor cells and have evolved complex strategies to suppress immune responses through multiple mechanisms, including the release of soluble factors and the over-expression of molecules implicated in cancer immune evasion. This chapter discusses the latest advancements in understanding of the immunological BM niche and highlights current and future immunotherapeutic strategies to target leukemia CSCs and overcome therapeutic resistance in the clinic. PMID:29466292

NCI, NHLBI/PBMTC First International Conference on Late Effects after Pediatric Hematopoietic Cell Transplantation: Endocrine Challenges--Thyroid Dysfunction, Growth Impairment, Bone Health, & Reproductive Risks

PubMed Central

Dvorak, Christopher C.; Gracia, Clarisa R.; Sanders, Jean E.; Cheng, Edward Y.; Baker, K. Scott; Pulsipher, Michael A.; Petryk, Anna

2011-01-01

The endocrine system is highly susceptible to damage by high-dose chemotherapy and/or irradiation prior to hematopoietic cell transplantation (HCT) during childhood. The specific endocrine organs most affected by HCT include the thyroid gland, the pituitary, and the gonads. In addition, hormones that support development and stability of the skeletal system are also affected. Insufficiency of thyroid hormone is one of the most common late sequelae of HCT, and occurs more often in young children. Deficiency in the pituitary’s production of growth hormone is a problem of unique concern to the pediatric population. The reproductive risks of HCT depend on the patient’s gender and pubertal status at the time of HCT. Pubertal or gonadal failure frequently occurs, especially in females. Infertility risks for both genders remain high, while methods of fertility preservation are limited in all but post-pubertal males. Bone health post-HCT can be compromised by low bone mineral density as well as avascular necrosis, but the data on both problems in the pediatric HCT population are limited. In this paper, the current state of knowledge, gaps in that knowledge, and recommendations for future research are addressed in detail for each of these systems. PMID:22005649

The bone marrow niche, stem cells, and leukemia: impact of drugs, chemicals, and the environment.

PubMed

Snyder, Robert

2014-03-01

Detection, treatment, and prevention of bone marrow diseases have long been the aims of experimental and clinical hematologists and mechanistically oriented toxicologists. Among these diseases is aplastic anemia, which manifests as the cessation of normal blood cell production; the leukemias, in contrast, feature the production of excessive hematologic cancer cells. Both diseases are associated with exposure to either industrial chemicals or cancer chemotherapeutic agents. Studies of hematopoietic bone marrow cells in culture have shown that the generation of circulating blood cells requires the interaction of hematopoietic stem cells (HSCs) with supporting marrow stromal cells; yet, isolation of HSCs from bone destroys the unique morphology of the marrow stroma in which the HSCs reside. Imaging techniques and related studies have made it possible to examine specific niches where HSCs may either initiate differentiation toward mature blood cells or reside in a dormant state awaiting a signal to begin differentiation. HSCs and related cells may be highly vulnerable to the mutagenic or toxic effects of drugs or other chemicals early in these processes. Additional studies are required to determine the mechanisms by which drug or chemical exposure may affect these cells and lead to either depression of bone marrow function or to leukemia. © 2014 New York Academy of Sciences.

Production and characterization of murine monoclonal antibody against synthetic peptide of CD34.

PubMed

Maleki, Leili Aghebati; Majidi, Jafar; Baradaran, Behzad; Abdolalizadeh, Jalal; Akbari, Aliakbar Movassaghpour

2013-01-01

The treatment of hematologic malignancies and immunodeficiency diseases are offered by hematopoietic stem cells (HSCs) as a unique self-renewal and differentiation source which most commonly is selected by CD34 surface marker for HSC. The purpose of this study was to develop and characterize monoclonal antibody against CD34 antigen for detection of hematopoietic stem cells. Balb/c mice were immunized with two synthetic peptides of CD34 and Spleen cells were fused with SP2/0.Fused cells were grown in hypoxanthine, aminopterine and thymidine (HAT) selective medium and cloned by limiting dilution. Large scale of monoclonal antibodies was produced by mouse ascites production of mAb (in vivo) method. Monoclonal antibody was purified by chromatography. Then reactivity of these antibodies was evaluated in different immunological assays including ELISA, immunofluorescence (IF), western blot (WB) and flowcytometry. In this study, between five positive clone wells, two clones were chosen for limiting dilution. Limiting dilution product was one monoclone (3-D5 monoclone) with absorbance about 2. Isotype of this mAb was identified as IgG1 class with Kappa (κ) light chain. This antibody is highly specific and functional in biomedical applications such as ELISA, flowcytometry, immunofluorescence, and western blot assays.

Embryonic hematopoiesis in vertebrate somites gives rise to definitive hematopoietic stem cells

PubMed Central

Qiu, Juhui; Fan, Xiaoying; Wang, Yixia; Jin, Hongbin; Song, Yixiao; Han, Yang; Huang, Shenghong; Meng, Yaping; Tang, Fuchou; Meng, Anming

2016-01-01

Hematopoietic stem cells (HSCs) replenish all types of blood cells. It is debating whether HSCs in adults solely originate from the aorta-gonad-mesonephros (AGM) region, more specifically, the dorsal aorta, during embryogenesis. Here, we report that somite hematopoiesis, a previously unwitnessed hematopoiesis, can generate definitive HSCs (dHSCs) in zebrafish. By transgenic lineage tracing, we found that a subset of cells within the forming somites emigrate ventromedially and mix with lateral plate mesoderm-derived primitive hematopoietic cells before the blood circulation starts. These somite-derived hematopoietic precursors and stem cells (sHPSCs) subsequently enter the circulation and colonize the kidney of larvae and adults. RNA-seq analysis reveals that sHPSCs express hematopoietic genes with sustained expression of many muscle/skeletal genes. Embryonic sHPSCs transplanted into wild-type embryos expand during growth and survive for life time with differentiation into various hematopoietic lineages, indicating self-renewal and multipotency features. Therefore, the embryonic origin of dHSCs in adults is not restricted to the AGM. PMID:27252540

Long survival and immunologic reconstitution following transplantation with syngeneic or allogeneic fetal liver and neonatal spleen cells. [X radiation, mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yunis, E.J.; Fernandes, G.; Smith, J.

1976-12-01

Spleen cells from newborn syngeneic and allogeneic mice that lack fully differentiated T lymphocytes can be used as a hematopoietic source to reconstitute both hematopoietic and lymphoid systems of lethally irradiated mice without producing a GVHR. Fetal liver cells from syngeneic and allogeneic mice that lack postthymic T lymphocytes can also be used for hematopoietic and immunologic reconstitution of lethally irradiated mice without producing GVHR. Immunologic deficiency is observed in some experiments in mice given supralethal irradiation (1000 R) and fetal liver as reconstituting hematopoietic tissue. The findings suggest that T cells, at an early stage of differentiation, are moremore » susceptible to tolerance induction than are T lymphocytes at later stages of differentiation and do not, in general, produce GVHR. It is postulated that hematopoietic cells, free of postthymic lymphoid cells, can be used for hematopoietic or immunologic reconstitution and celular engineering without producing GVHD.« less

Adoptive immunotherapy against kidney targets in dog-leukocyte antigen-identical mixed hematopoietic canine chimeras.

PubMed

Junghanss, Christian; Takatu, Alessandra; Little, Marie-Terese; Maciej Zaucha, J; Zellmer, Eustacia; Yunusov, Murad; Sale, George; Georges, George E; Storb, Rainer

2003-02-15

Stable mixed-donor-host-hematopoietic chimerism can serve as a platform for adoptive immunotherapy. Infusions of donor lymphocytes (DLI) sensitized against hematopoietic cells converted mixed hematopoietic into full-donor chimerism in dog-leukocyte antigen (DLA)-identical littermates. Whether sensitization against tissue of solid organs leads to organ-specific immunity that can be transferred by DLI was unknown and was investigated in these experiments using the kidney as target. DLA-identical recipients with established stable mixed-donor-host-hematopoietic chimerism were used. In five pairs, hematopoietic stem-cell transplant (HSCT) donors were sensitized by kidney transplantation from the respective chimeras. In a second group, five HSCT donors received vaccinations that were generated from kidney cells of the respective mixed chimeras. Twenty-eight days after sensitization, DLI were administered to the mixed-hematopoietic chimeras. All HSCT donors rejected their kidney grafts from their mixed-chimeric recipients within 22 to 45 days. DLI caused no sustained graft-versus-kidney effects in the mixed-chimeric recipients. However, DLI donors sensitized by kidney transplantation converted 4 of 5 mixed chimeras into virtually complete (>95%) donor-type chimeras, compared with 1 of 5 mixed chimeras given DLI by vaccination from sensitized donors. Although DLA-identical kidney grafts from mixed-hematopoietic chimeras were readily rejected by their HSCT donors, subsequent transfusions of sensitized-donor lymphocytes into mixed chimeras converted mixed to all-donor chimerism but failed to induce graft-versus-kidney effects. Vaccination strategies in lieu of kidney grafts failed to convert mixed chimerism.

Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators.

PubMed

Silberstein, Lev; Goncalves, Kevin A; Kharchenko, Peter V; Turcotte, Raphael; Kfoury, Youmna; Mercier, Francois; Baryawno, Ninib; Severe, Nicolas; Bachand, Jacqueline; Spencer, Joel A; Papazian, Ani; Lee, Dongjun; Chitteti, Brahmananda Reddy; Srour, Edward F; Hoggatt, Jonathan; Tate, Tiffany; Lo Celso, Cristina; Ono, Noriaki; Nutt, Stephen; Heino, Jyrki; Sipilä, Kalle; Shioda, Toshihiro; Osawa, Masatake; Lin, Charles P; Hu, Guo-Fu; Scadden, David T

2016-10-06

Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on the differential single-cell gene expression analysis of mesenchymal osteolineage cells close to, and further removed from, hematopoietic stem/progenitor cells (HSPCs) to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. We functionally examined, among the genes that were preferentially expressed in proximal cells, three secreted or cell-surface molecules not previously connected to HSPC biology-the secreted RNase angiogenin, the cytokine IL18, and the adhesion molecule Embigin-and discovered that all of these factors are HSPC quiescence regulators. Therefore, our proximity-based differential single-cell approach reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance the understanding of microenvironmental regulation of stem cell function. Copyright © 2016 Elsevier Inc. All rights reserved.

Regulation of Hemopoietic Stem Cell Turnover and Population Size in Neonatal Mice

DTIC Science & Technology

1975-04-01

Following birth the hematopoietic stem cell population of the liver as measured by the in vivo spleen nodule assay (CFU) declines with a halving time...of about 48 hours. The stem cell population of the spleen grows exponentially with a doubling time of about 17 hours. In vitro incubation with high...single spleen colonies derived from neonatal liver and spleen CFU that both stem cell populations have a high self-renewal capacity. Thus, the decline in

Regulatory coding of lymphoid lineage choice by hematopoietic transcription factors

NASA Technical Reports Server (NTRS)

Warren, Luigi A.; Rothenberg, Ellen V.

2003-01-01

During lymphopoiesis, precursor cells negotiate a complex regulatory space, defined by the levels of several competing and cross-regulating transcription factors, before arriving at stable states of commitment to the B-, T- and NK-specific developmental programs. Recent perturbation experiments provide evidence that this space has three major axes, corresponding to the PU.1 versus GATA-1 balance, the intensity of Notch signaling through the CSL pathway, and the ratio of E-box transcription factors to their Id protein antagonists.

Thermal inactivation of infectious hematopoietic necrosis and infectious pancreatic necrosis virus

USGS Publications Warehouse

Gosting, L.; Gould, R.W.

1981-01-01

A plaque assay was used to follow the inactivation kinetics of infectious hematopoietic necrosis virus and infectious pancreatic necrosis virus in cell culture media at various temperatures. Inactivation of infectious hematopoietic necrosis virus in a visceral organ slurry was compared with that in culture media.

Idiopathic aplastic anemia: diagnosis and classification.

PubMed

Dolberg, Osnat Jarchowsky; Levy, Yair

2014-01-01

Aplastic anemia (AA) is a disease characterized by pancytopenia and hypoplastic bone marrow caused by the decrease of hematopoietic stem cells. The pathogenesis of AA is complex and involves an abnormal hematopoietic microenvironment, hematopoietic stem cell/progenitor cell deficiencies and immunity disorders. Survival in severe aplastic anemia (SAA) has markedly improved in the past 4 decades because of advances in hematopoietic stem cell transplantation, immunosuppressive and biologic drugs, and supportive care. Herein, we will update the main issues concern AA according to our literature review. Copyright © 2014 Elsevier B.V. All rights reserved.