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Sample records for adult murine hematopoiesis

  1. Kras is Required for Adult Hematopoiesis.

    PubMed

    Damnernsawad, Alisa; Kong, Guangyao; Wen, Zhi; Liu, Yangang; Rajagopalan, Adhithi; You, Xiaona; Wang, Jinyong; Zhou, Yun; Ranheim, Erik A; Luo, Hongbo R; Chang, Qiang; Zhang, Jing

    2016-07-01

    Previous studies indicate that Kras is dispensable for fetal liver hematopoiesis, but its role in adult hematopoiesis remains unclear. Here, we generated a Kras conditional knockout allele to address this question. Deletion of Kras in adult bone marrow (BM) is mediated by Vav-Cre or inducible Mx1-Cre. We find that loss of Kras leads to greatly reduced thrombopoietin (TPO) signaling in hematopoietic stem cells (HSCs) and multipotent progenitors (MPPs), while stem cell factor-evoked ERK1/2 activation is not affected. The compromised TPO signaling is associated with reduced long term- and intermediate-term HSC compartments and a bias toward myeloid differentiation in MPPs. Although granulocyte macrophage colony-stimulating factor (GM-CSF)-evoked ERK1/2 activation is only moderately decreased in Kras(-/-) myeloid progenitors, it is blunted in neutrophils and neutrophil survival is significantly reduced in vitro. At 9-12 months old, Kras conditional knockout mice develop profound hematopoietic defects, including splenomegaly, an expanded neutrophil compartment, and reduced B cell number. In a serial transplantation assay, the reconstitution potential of Kras(-/-) BM cells is greatly compromised, which is attributable to defects in the self-renewal of Kras(-/-) HSCs and defects in differentiated hematopoietic cells. Our results demonstrate that Kras is a major regulator of TPO and GM-CSF signaling in specific populations of hematopoietic cells and its function is required for adult hematopoiesis. Stem Cells 2016;34:1859-1871. PMID:26972179

  2. Stable multilineage xenogeneic replacement of definitive hematopoiesis in adult zebrafish.

    PubMed

    Hess, Isabell; Boehm, Thomas

    2016-01-01

    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. PMID:26777855

  3. Stable multilineage xenogeneic replacement of definitive hematopoiesis in adult zebrafish

    PubMed Central

    Hess, Isabell; Boehm, Thomas

    2016-01-01

    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-mybI181N 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. PMID:26777855

  4. Modulation of retinoblastoma gene in normal adult hematopoiesis: peak expression and functional role in advanced erythroid differentiation.

    PubMed Central

    Condorelli, G L; Testa, U; Valtieri, M; Vitelli, L; De Luca, A; Barberi, T; Montesoro, E; Campisi, S; Giordano, A; Peschle, C

    1995-01-01

    The retinoblastoma (RB) gene specifies a nuclear phosphoprotein (pRb 105), which is a prototype tumor suppressor inactivated in a variety of human tumors. Recent studies suggest that RB is also involved in embryonic development of murine central nervous and hematopoietic systems. We have investigated RB expression and function in human adult hematopoiesis--i.e., in liquid suspension culture of purified quiescent hematopoietic progenitor cells (HPCs) induced by growth factor stimulus to proliferation and unilinage differentiation/maturation through the erythroid or granulocytic lineage. In the initial HPC differentiation stages, the RB gene is gradually induced at the mRNA and protein level in both erythroid and granulopoietic cultures. In late HPC differentiation and then precursor maturation, RB gene expression is sustained in the erythroid lineage, whereas it is sharply downmodulated in the granulocytic series. Functional studies were performed by treatment of HPC differentiation culture with phosphorothioate antisense oligomer targeting Rb mRNA; coherent with the expression pattern, oligomer treatment of late HPCs causes a dose-dependent and selective inhibition of erythroid colony formation. These observations suggest that the RB gene plays an erythroid- and stage-specific functional role in normal adult hematopoiesis, particularly at the level of late erythroid HPCs. Images Fig. 2 Fig. 3 Fig. 4 PMID:7761404

  5. Loss of the Homeodomain Transcription Factor Prep1 Perturbs Adult Hematopoiesis in the Bone Marrow.

    PubMed

    Yoshioka, Kentaro; Oda, Akihisa; Notsu, Chihiro; Ohtsuka, Takafumi; Kawai, Yasuhiro; Suzuki, Sadafumi; Nakamura, Takuro; Mabuchi, Yo; Matsuzaki, Yumi; Goitsuka, Ryo

    2015-01-01

    Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical role in embryonic hematopoiesis, as its insufficiency caused late embryonic lethality associated with defective hematopoiesis and angiogenesis. In the present study, we generated hematopoietic- and endothelial cell-specific Prep1-deficient mice and demonstrated that expression of Prep1 in the hematopoietic cell compartment is not essential for either embryonic or adult hematopoiesis, although its absence causes significant hematopoietic abnormalities in the adult bone marrow. Loss of Prep1 promotes cell cycling of hematopoietic stem/progenitor cells (HSPC), leading to the expansion of the HSPC pool. Prep1 deficiency also results in the accumulation of lineage-committed progenitors, increased monocyte/macrophage differentiation and arrested erythroid maturation. Maturation of T cells and B cells is also perturbed in Prep-deficient mice. These findings provide novel insight into the pleiotropic roles of Prep1 in adult hematopoiesis that were unrecognized in previous studies using germline Prep1 hypomorphic mice. PMID:26285139

  6. Loss of the Homeodomain Transcription Factor Prep1 Perturbs Adult Hematopoiesis in the Bone Marrow

    PubMed Central

    Yoshioka, Kentaro; Oda, Akihisa; Notsu, Chihiro; Ohtsuka, Takafumi; Kawai, Yasuhiro; Suzuki, Sadafumi; Nakamura, Takuro; Mabuchi, Yo; Matsuzaki, Yumi; Goitsuka, Ryo

    2015-01-01

    Prep1, a TALE-family homeodomain transcription factor, has been demonstrated to play a critical role in embryonic hematopoiesis, as its insufficiency caused late embryonic lethality associated with defective hematopoiesis and angiogenesis. In the present study, we generated hematopoietic- and endothelial cell-specific Prep1-deficient mice and demonstrated that expression of Prep1 in the hematopoietic cell compartment is not essential for either embryonic or adult hematopoiesis, although its absence causes significant hematopoietic abnormalities in the adult bone marrow. Loss of Prep1 promotes cell cycling of hematopoietic stem/progenitor cells (HSPC), leading to the expansion of the HSPC pool. Prep1 deficiency also results in the accumulation of lineage-committed progenitors, increased monocyte/macrophage differentiation and arrested erythroid maturation. Maturation of T cells and B cells is also perturbed in Prep-deficient mice. These findings provide novel insight into the pleiotropic roles of Prep1 in adult hematopoiesis that were unrecognized in previous studies using germline Prep1 hypomorphic mice. PMID:26285139

  7. Regulation of adult hematopoiesis by the a disintegrin and metalloproteinase 10 (ADAM10).

    PubMed

    Weber, Silvio; Wetzel, Sebastian; Prox, Johannes; Lehmann, Tobias; Schneppenheim, Janna; Donners, Marjo; Saftig, Paul

    2013-12-13

    Adult hematopoiesis requires tightly regulated cell-cell interactions between hematopoietic cells and the bone marrow stromal microenvironment. We addressed the question if the ectodomain sheddase ADAM10 is essential to regulate adult hematopoiesis. Induced ADAM10 deletion in hematopoietic cells resulted in morphological and histological abnormalities that resemble an unclassified myeloproliferative disorder (MPD). The MPD was characterized by an expansion of granulocytic subpopulations and their infiltration of peripheral hematopoietic tissues, the development of hepatosplenomegaly with extramedullary erythropoiesis, lymphnodepathy and death of the mice around 20weeks after induction. ADAM10 expression analysis during the different stages of the MPD revealed that non-targeted hematopoietic cells repopulated the immune system of the ADAM10-deficient mice. Examination of mice with a myeloid- or epidermis-specific deletion of ADAM10 and bone marrow transplantation (BMT) experiments indicated that the development of the MPD can be triggered by non-cell autonomous effects. We found that plasma levels of clinical markers for MPD such as G-CSF, TIMP-1 and IL-16 were significantly elevated in ADAM10-deficient mice. Our findings indicate that a tightly controlled ADAM10 expression is needed to balance hematopoietic cell-fate decisions in adult mice. PMID:24239882

  8. RCAD/Ufl1, a Ufm1 E3 ligase, is essential for hematopoietic stem cell function and murine hematopoiesis.

    PubMed

    Zhang, M; Zhu, X; Zhang, Y; Cai, Y; Chen, J; Sivaprakasam, S; Gurav, A; Pi, W; Makala, L; Wu, J; Pace, B; Tuan-Lo, D; Ganapathy, V; Singh, N; Li, H

    2015-12-01

    The Ufm1 conjugation system is a novel ubiquitin-like modification system, consisting of Ufm1, Uba5 (E1), Ufc1 (E2) and poorly characterized E3 ligase(s). RCAD/Ufl1 (also known as KIAA0776, NLBP and Maxer) was reported to function as a Ufm1 E3 ligase in ufmylation (Ufm1-mediated conjugation) of DDRGK1 and ASC1 proteins. It has also been implicated in estrogen receptor signaling, unfolded protein response (UPR) and neurodegeneration, yet its physiological function remains completely unknown. In this study, we report that RCAD/Ufl1 is essential for embryonic development, hematopoietic stem cell (HSC) survival and erythroid differentiation. Both germ-line and somatic deletion of RCAD/Ufl1 impaired hematopoietic development, resulting in severe anemia, cytopenia and ultimately animal death. Depletion of RCAD/Ufl1 caused elevated endoplasmic reticulum stress and evoked UPR in bone marrow cells. In addition, loss of RCAD/Ufl1 blocked autophagic degradation, increased mitochondrial mass and reactive oxygen species, and led to DNA damage response, p53 activation and enhanced cell death of HSCs. Collectively, our study provides the first genetic evidence for the indispensable role of RCAD/Ufl1 in murine hematopoiesis and development. The finding of RCAD/Ufl1 as a key regulator of cellular stress response sheds a light into the role of a novel protein network including RCAD/Ufl1 and its associated proteins in regulating cellular homeostasis. PMID:25952549

  9. Early hematopoiesis and macrophage development.

    PubMed

    McGrath, Kathleen E; Frame, Jenna M; Palis, James

    2015-12-01

    The paradigm that all blood cells are derived from hematopoietic stem cells (HSCs) has been challenged by two findings. First, there are tissue-resident hematopoietic cells, including subsets of macrophages that are not replenished by adult HSCs, but instead are maintained by self-renewal of fetal-derived cells. Second, during embryogenesis, there is a conserved program of HSC-independent hematopoiesis that precedes HSC function and is required for embryonic survival. The presence of waves of HSC-independent hematopoiesis as well as fetal HSCs raises questions about the origin of fetal-derived adult tissue-resident macrophages. In the murine embryo, historical examination of embryonic macrophage and monocyte populations combined with recent reports utilizing genetic lineage-tracing approaches has led to a model of macrophage ontogeny that can be integrated with existing models of hematopoietic ontogeny. The first wave of hematopoiesis contains primitive erythroid, megakaryocyte and macrophage progenitors that arise in the yolk sac, and these macrophage progenitors are the source of early macrophages throughout the embryo, including the liver. A second wave of multipotential erythro-myeloid progenitors (EMPs) also arises in the yolk sac. EMPs colonize the fetal liver, initiating myelopoiesis and forming macrophages. Lineage tracing indicates that this second wave of macrophages are distributed in most fetal tissues, although not appreciably in the brain. Thus, fetal-derived adult tissue-resident macrophages, other than microglia, appear to predominately derive from EMPs. While HSCs emerge at midgestation and colonize the fetal liver, the relative contribution of fetal HSCs to tissue macrophages at later stages of development is unclear. The inclusion of macrophage potential in multiple waves of hematopoiesis is consistent with reports of their functional roles throughout development in innate immunity, phagocytosis, and tissue morphogenesis and remodeling

  10. Stable differentiation and clonality of murine long-term hematopoiesis after extended reduced-intensity selection for MGMT P140K transgene expression

    PubMed Central

    Ball, Claudia R.; Pilz, Ingo H.; Schmidt, Manfred; Fessler, Sylvia; Williams, David A.; Glimm, Hanno

    2007-01-01

    Efficient in vivo selection increases survival of gene-corrected hematopoietic stem cells (HSCs) and protects hematopoiesis, even if initial gene transfer efficiency is low. Moreover, selection of a limited number of transduced HSCs lowers the number of cell clones at risk of gene activation by insertional mutagenesis. However, a limited clonal repertoire greatly increases the proliferation stress of each individual clone. Therefore, understanding the impact of in vivo selection on proliferation and lineage differentiation of stem-cell clones is essential for its clinical use. We established minimal cell and drug dosage requirements for selection of P140K mutant O6-methylguanine-DNA-methyltransferase (MGMT P140K)–expressing HSCs and monitored their differentiation potential and clonality under long-term selective stress. Up to 17 administrations of O6-benzylguanine (O6-BG) and 1,3-bis(2-chloroethyl)-1-nitroso-urea (BCNU) did not impair long-term differentiation and proliferation of MGMT P140K–expressing stem-cell clones in mice that underwent serial transplantation and did not lead to clonal exhaustion. Interestingly, not all gene-modified hematopoietic repopulating cell clones were efficiently selectable. Our studies demonstrate that the normal function of murine hematopoietic stem and progenitor cells is not compromised by reduced-intensity long-term in vivo selection, thus underscoring the potential value of MGMT P140K selection for clinical gene therapy. PMID:17496202

  11. RUNX1B Expression Is Highly Heterogeneous and Distinguishes Megakaryocytic and Erythroid Lineage Fate in Adult Mouse Hematopoiesis

    PubMed Central

    Draper, Julia E.; Sroczynska, Patrycja; Tsoulaki, Olga; Leong, Hui Sun; Fadlullah, Muhammad Z. H.; Miller, Crispin; Kouskoff, Valerie; Lacaud, Georges

    2016-01-01

    The Core Binding Factor (CBF) protein RUNX1 is a master regulator of definitive hematopoiesis, crucial for hematopoietic stem cell (HSC) emergence during ontogeny. RUNX1 also plays vital roles in adult mice, in regulating the correct specification of numerous blood lineages. Akin to the other mammalian Runx genes, Runx1 has two promoters P1 (distal) and P2 (proximal) which generate distinct protein isoforms. The activities and specific relevance of these two promoters in adult hematopoiesis remain to be fully elucidated. Utilizing a dual reporter mouse model we demonstrate that the distal P1 promoter is broadly active in adult hematopoietic stem and progenitor cell (HSPC) populations. By contrast the activity of the proximal P2 promoter is more restricted and its upregulation, in both the immature Lineage- Sca1high cKithigh (LSK) and bipotential Pre-Megakaryocytic/Erythroid Progenitor (PreMegE) populations, coincides with a loss of erythroid (Ery) specification. Accordingly the PreMegE population can be prospectively separated into “pro-erythroid” and “pro-megakaryocyte” populations based on Runx1 P2 activity. Comparative gene expression analyses between Runx1 P2+ and P2- populations indicated that levels of CD34 expression could substitute for P2 activity to distinguish these two cell populations in wild type (WT) bone marrow (BM). Prospective isolation of these two populations will enable the further investigation of molecular mechanisms involved in megakaryocytic/erythroid (Mk/Ery) cell fate decisions. Having characterized the extensive activity of P1, we utilized a P1-GFP homozygous mouse model to analyze the impact of the complete absence of Runx1 P1 expression in adult mice and observed strong defects in the T cell lineage. Finally, we investigated how the leukemic fusion protein AML1-ETO9a might influence Runx1 promoter usage. Short-term AML1-ETO9a induction in BM resulted in preferential P2 upregulation, suggesting its expression may be important to

  12. Extramedullary hematopoiesis in pilomatricomas.

    PubMed

    Kaddu, S; Beham-Schmid, C; Soyer, H P; Hödl, S; Beham, A; Kerl, H

    1995-04-01

    We report on seven adult patients with pilomatricomas showing histopathologic findings of extramedullary hematopoiesis. There was no Ovidence of hematological disorders or systemic diseases. Clinically, the lesions appeared to be firm, painless nodules situated on the upper extremities, head, and back. Histopathologically, they represented stereotypical examples of regressive pilomatricomas with relatively small basaloid areas and large masses of cornified eosinophilic material containing shadow cells with variable areas of calcification or ossification. Bone marrow cellular elements, including myeloid and erythroid precursors, and (in two cases) megakaryocytes were present. The finding of extramedullary hematopoiesis in seven (5.8%) of 120 cases of pilomatricomas may suggest that this phenomenon is not uncommon in these neoplasms. Interestingly, hematopoietic infiltrates were histopathologically detected to be contiguous with areas of osseous metaplasia in only two of the seven pilomatricomas in our study. It should further be stressed that extramedullary hematopoiesis in regressive lesions of pilomatricomas is a localized phenomenon and that these findings may not be linked with a systemic hematological disorder. The significance of extramedullary hematopoiesis in pilomatricomas, however, remains to be determined. PMID:8600776

  13. Crustacean hematopoiesis.

    PubMed

    Söderhäll, Irene

    2016-05-01

    Crustacean hemocytes are important mediators of immune reactions, and the regulation of hemocyte homeostasis is of utmost importance for the health of these animals. This review discusses the current knowledge on the lineages, synthesis and differentiation of hemocytes in crustaceans. Hematopoietic tissues, their origins, and the regulation of hematopoiesis during molting, seasonal variation and infection are discussed. Furthermore, studies concerning the molecular regulation of hemocyte formation in crustaceans are also described, and the different lineages and their molecular markers are discussed and compared with several insect species. Signaling pathways and the regulation of hematopoiesis by transcription factors are typically conserved among these arthropods, whereas cytokines and growth factors are more variable and species specific. However, considering the great diversity among the crustaceans, one should be cautious in drawing general conclusions from studies of only a few species. PMID:26721583

  14. Wnts are dispensable for differentiation and self-renewal of adult murine hematopoietic stem cells

    PubMed Central

    Kabiri, Zahra; Numata, Akihiko; Kawasaki, Akira; Tenen, Daniel G.

    2015-01-01

    Wnt signaling controls early embryonic hematopoiesis and dysregulated β-catenin is implicated in leukemia. However, the role of Wnts and their source in adult hematopoiesis is still unclear, and is clinically important as upstream Wnt inhibitors enter clinical trials. We blocked Wnt secretion in hematopoietic lineages by targeting Porcn, a membrane-bound O-acyltransferase that is indispensable for the activity and secretion of all vertebrate Wnts. Surprisingly, deletion of Porcn in Rosa-CreERT2/PorcnDel, MX1-Cre/PorcnDel, and Vav-Cre/PorcnDel mice had no effects on proliferation, differentiation, or self-renewal of adult hematopoietic stem cells. Targeting Wnt secretion in the bone marrow niche by treatment with a PORCN inhibitor, C59, similarly had no effect on hematopoiesis. These results exclude a role for hematopoietic PORCN-dependent Wnts in adult hematopoiesis. Clinical use of upstream Wnt inhibitors is not likely to be limited by effects on hematopoiesis. PMID:26089398

  15. Embryonic hematopoiesis.

    PubMed

    Golub, Rachel; Cumano, Ana

    2013-12-01

    Blood cells are continually produced from a pool of progenitors that derive from hematopoietic stem cells (HSCs). In vertebrates, the hematopoietic system develops from two distinct waves or generation of precursors. The first wave occurs in the yolk sac, in mammals or equivalent embryonic structure, and produces nucleated primitive erythrocytes that provide the embryo with the first oxygen transporter and are, therefore, essential for the viability of the embryo. The yolk sac also produces myeloid cells that migrate to the central nervous system and to the skin to form the microglia and skin specific macrophages, the Langerhans cells. The second wave occurs in the dorsal aorta and produces multipotential hematopoietic progenitors. These cells are generated once in the lifetime from mesoderm derivatives closely related to endothelial cells, during a short period of embryonic development. Newly generated cells do not reconstitute the hematopoietic compartment of conventional recipients; therefore, they are designated as immature or pre-HSCs. They undergo maturation into adult HSCs in the aorta or in the fetal liver accompanied by the expression of MHC class I, CD45, CD150, Sca-1 and the absence of CD48. Differentiation of HSCs first occurs in the fetal liver, giving rise to mature blood cells. HSCs also expand in the fetal liver, and in a short time period (four days in the mouse embryo), they increase over 40-fold. HSCs and progenitor cells exit the fetal liver and colonize the spleen, where differentiation to the myeloid lineage and particular lymphoid subsets is favored. PMID:24041595

  16. Hematopoiesis in snakes (Ophidia).

    PubMed

    Dabrowski, Z; Tabarowski, Z; Sano-Martins, I S; Spadacci-Morena, D D; Witkowska-Pelc, E; Krzysztofowicz, E; Spodaryk, K

    2002-01-01

    Locations of the hematopoietic tissue have been described in the following ophidian species: Bothrops jararaca, Bothrops jararacusu, Waglerophis merremii, Elaphe teniura teniura, Boa constrictor, and Python reticulatus. Studies were carried out on perfusion fixed vertebrae, ribs, spleen, liver, thymus, and kidney. Routine histological technique was applied using both light and electron microscopy. Hematopoietic tissue was found in the following locations of the vertebrae: neural spine, neural arch, postzygophysis processes, hypapophysis, vertebral centre. Moreover, intense hematopoiesis was found inside the ribs. In the spleen and thymus, only lymphopoiesis was found. Hematopoietic islets in the spleen were sporadically found only in young specimens. No hematopoiesis was observed in the liver and kidney. In the studied species, there were no differences in the location of hematopoietic tissue. A new model of mature and immature blood cell release to the lumen of marrow sinuses different from that known to operate in higher vertebrates is proposed. PMID:12056654

  17. Mapping hematopoiesis in a fully regenerative vertebrate: the axolotl

    PubMed Central

    Lopez, David; Lin, Li; Monaghan, James R.; Cogle, Christopher R.; Bova, Frank J.; Maden, Malcolm

    2014-01-01

    Hematopoietic stem cell (HSC)-derived cells are involved in wound healing responses throughout the body. Unfortunately for mammals, wound repair typically results in scarring and nonfunctional reparation. Among vertebrates, none display such an extensive ability for adult regeneration as urodele amphibians, including 1 of the more popular models: the axolotl. However, a lack of knowledge of axolotl hematopoiesis hinders the use of this animal for the study of hematopoietic cells in scar-free wound healing and tissue regeneration. We used white and cytomegalovirus:green fluorescent protein+ transgenic white axolotl strains to map sites of hematopoiesis and develop hematopoietic cell transplant methodology. We also established a fluorescence-activated cell sorter enrichment technique for major blood lineages and colony-forming unit assays for hematopoietic progenitors. The liver and spleen are both active sites of hematopoiesis in adult axolotls and contain transplantable HSCs capable of long-term multilineage blood reconstitution. As in zebrafish, use of the white axolotl mutant allows direct visualization of homing, engraftment, and hematopoiesis in real time. Donor-derived hematopoiesis occurred for >2 years in recipients generating stable hematopoietic chimeras. Organ segregation, made possible by embryonic microsurgeries wherein halves of 2 differently colored embryos were joined, indicate that the spleen is the definitive site of adult hematopoiesis. PMID:24802774

  18. Differential expression of murine adult hemoglobins in early ontogeny

    SciTech Connect

    Wawrzyniak, C.J.; Lewis, S.E.; Popp, R.A.

    1985-01-01

    A hemoglobin mutation is described that permits study of the expression of the two adult ..beta..-globin genes throughout fetal and postnatal development. Mice with a mutation at the Hbb/sup s/, ..beta..-globin locus, were used to study the relative levels of ..beta..-s2major and ..beta..-sminor globins specified by the mutant Hbb/sup s2/ haplotype during development. At 11.5 days of gestation ..beta..-sminor comprised over 80% and ..beta..-s2major under 20% of the adult beta-globin. The relative level of ..beta..-sminor decreased through fetal development; at birth ..beta..-sminor represented 33.7% of the ..beta..-globin. The adult values of 71.0% ..beta..-s2major and 29.0% ..beta..-sminor globin are expressed in mice six days after birth. Because the two ..beta..-globin genes are expressed in mice of the Hbb/sup 2s/ haplotype, both the ..beta..-smajor and ..beta..-sminor genes must be expressed in mice of the Hbb/sup s/ haplotype. Expression of the ..beta..-sminor gene is elevated to 35.6% in Hbb/sup s2/ mice that have been bled repeatedly. Thus, the 5' ..beta..-s2major and 3' ..beta..-sminor genes of the Hbb/sup s2/ haplotype and, presumably the 5' ..beta..-smajor and 3' ..beta..-sminor genes of the Hbb/sup s/ haplotype, are regulated independently and are homologous to the 5' ..beta..-dmajor and 3' ..beta..-dminor genes of the Hbb/sup d/ haplotype. Mice of the Hbb/sup s2/ haplotype are better than mice of the Hbb/sup d/ haplotytpe for studying the mechanisms of hemoglobin switching because the Hbb/sup s2/ each of the three embryonic and two adult hemoglobins can be separated by electrophoresis. 17 refs., 3 figs.

  19. Insect immunology and hematopoiesis.

    PubMed

    Hillyer, Julián F

    2016-05-01

    Insects combat infection by mounting powerful immune responses that are mediated by hemocytes, the fat body, the midgut, the salivary glands and other tissues. Foreign organisms that have entered the body of an insect are recognized by the immune system when pathogen-associated molecular patterns bind host-derived pattern recognition receptors. This, in turn, activates immune signaling pathways that amplify the immune response, induce the production of factors with antimicrobial activity, and activate effector pathways. Among the immune signaling pathways are the Toll, Imd, Jak/Stat, JNK, and insulin pathways. Activation of these and other pathways leads to pathogen killing via phagocytosis, melanization, cellular encapsulation, nodulation, lysis, RNAi-mediated virus destruction, autophagy and apoptosis. This review details these and other aspects of immunity in insects, and discusses how the immune and circulatory systems have co-adapted to combat infection, how hemocyte replication and differentiation takes place (hematopoiesis), how an infection prepares an insect for a subsequent infection (immune priming), how environmental factors such as temperature and the age of the insect impact the immune response, and how social immunity protects entire groups. Finally, this review highlights some underexplored areas in the field of insect immunobiology. PMID:26695127

  20. Piwi genes are dispensable for normal hematopoiesis in mice.

    PubMed

    Nolde, Mona J; Cheng, Ee-Chun; Guo, Shangqin; Lin, Haifan

    2013-01-01

    Hematopoietic stem cells (HSC) must engage in a life-long balance between self-renewal and differentiation to sustain hematopoiesis. The highly conserved PIWI protein family regulates proliferative states of stem cells and their progeny in diverse organisms. A Human piwi gene (for clarity, the non-italicized "piwi" refers to the gene subfamily), HIWI (PIWIL1), is expressed in CD34⁺ stem/progenitor cells and transient expression of HIWI in a human leukemia cell line drastically reduces cell proliferation, implying the potential function of these proteins in hematopoiesis. Here, we report that one of the three piwi genes in mice, Miwi2 (Piwil4), is expressed in primitive hematopoetic cell types within the bone marrow. Mice with a global deletion of all three piwi genes, Miwi, Mili, and Miwi2, are able to maintain long-term hematopoiesis with no observable effect on the homeostatic HSC compartment in adult mice. The PIWI-deficient hematopoetic cells are capable of normal lineage reconstitution after competitive transplantation. We further show that the three piwi genes are dispensable during hematopoietic recovery after myeloablative stress by 5-FU. Collectively, our data suggest that the function of the piwi gene subfamily is not required for normal adult hematopoiesis. PMID:24058407

  1. Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart

    SciTech Connect

    Weinberger, Florian Mehrkens, Dennis Starbatty, Jutta Nicol, Philipp Eschenhagen, Thomas

    2015-01-02

    Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1{sup +}) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1{sup +} cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ({sup 3}H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of {sup 3}H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1{sup +} cells. Whereas Islet{sup −} non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was not detected in >25,000 cells analyzed. Conclusions: Islet-1{sup +} cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes.

  2. Label-Retaining Cells in the Adult Murine Salivary Glands Possess Characteristics of Adult Progenitor Cells

    PubMed Central

    Chibly, Alejandro M.; Querin, Lauren; Harris, Zoey; Limesand, Kirsten H.

    2014-01-01

    Radiotherapy is the primary treatment for patients with head and neck cancer, which account for roughly 500,000 annual cases worldwide. Dysfunction of the salivary glands and associated conditions like xerostomia and dysphagia are often developed by these patients, greatly diminishing their life quality. Current preventative and palliative care fail to deliver an improvement in the quality of life, thus accentuating the need for regenerative therapies. In this study, a model of label retaining cells (LRCs) in murine salivary glands was developed, in which LRCs demonstrated proliferative potential and possessed markers of putative salivary progenitors. Mice were labeled with 5-Ethynyl-2′-deoxyuridine (EdU) at postnatal day 10 and chased for 8 weeks. Tissue sections from salivary glands obtained at the end of chase demonstrated co-localization between LRCs and the salivary progenitor markers keratin 5 and keratin 14, as well as kit mRNA, indicating that LRCs encompass a heterogeneous population of salivary progenitors. Proliferative potential of LRCs was demonstrated by a sphere assay, in which LRCs were found in primary and secondary spheres and they co-localized with the proliferation marker Ki67 throughout sphere formation. Surprisingly, LRCs were shown to be radio-resistant and evade apoptosis following radiation treatment. The clinical significance of these findings lie in the potential of this model to study the mechanisms that prevent salivary progenitors from maintaining homeostasis upon exposure to radiation, which will in turn facilitate the development of regenerative therapies for salivary gland dysfunction. PMID:25238060

  3. Unperturbed vs. post-transplantation hematopoiesis: both in vivo but different

    PubMed Central

    Busch, Katrin; Rodewald, Hans-Reimer

    2016-01-01

    Purpose of review Hematopoietic stem cell (HSC) transplantation has yielded tremendous information on experimental properties of HSCs. Yet, it remains unclear whether transplantation reflects the physiology of hematopoiesis. A limitation is the difficulty in accessing HSC functions without isolation, in-vitro manipulation and readout for potential. New genetic fate mapping and clonal marking techniques now shed light on hematopoiesis under physiological conditions. Recent findings Transposon-based genetic marks were introduced across the entire hematopoietic system to follow the clonal dynamics of these tags over time. A polyclonal source downstream from stem cells was found responsible for the production of at least granulocytes. In independent experiments, HSCs were genetically marked in adult mice, and the kinetics of label emergence throughout the system was followed over time. These experiments uncovered that during physiological steady-state hematopoiesis large numbers of HSCs yield differentiated progeny. Individual HSCs were active only rarely, indicating their very slow periodicity of differentiation rather than quiescence. Summary Noninvasive genetic experiments in mice have identified a major role of stem and progenitor cells downstream from HSCs as drivers of adult hematopoiesis, and revealed that post-transplantation hematopoiesis differs quantitatively from normal steady-state hematopoiesis. PMID:27213498

  4. Identification and enrichment of colony-forming cells from the adult murine pituitary

    SciTech Connect

    Lepore, D.A.; Roeszler, K.; Wagner, J.; Ross, S.A.; Bauer, K.; Thomas, P.Q. , E-Mail: paul.thomas@mcri.edu.au

    2005-08-01

    Stem and progenitor cells have been identified in many adult tissues including bone marrow, the central nervous system, and skin. While there is direct evidence to indicate the activity of a progenitor cell population in the pituitary gland, this putative subpopulation has not yet been identified. Herein we describe the isolation and characterization of a novel clonogenic cell type in the adult murine pituitary, which we have termed Pituitary Colony-Forming Cells (PCFCs). PCFCs constitute 0.2% of pituitary cells, and generate heterogeneous colonies from single cells. PCFCs exhibit variable proliferative potential, and may exceed 11 population doublings in 14 days. Enrichment of PCFCs to 61.5-fold with 100% recovery can be obtained through the active uptake of the fluorescent dipeptide, {beta}-Ala-Lys-N{epsilon}-AMCA. PCFCs are mostly contained within the large, agranular subpopulation of AMCA{sup +} cells, and constitute 28% of this fraction, corresponding to 140.5-fold enrichment. Interestingly, the AMCA{sup +} population contains rare cells that are GH{sup +} or PRL{sup +}. GH{sup +} cells were also identified in PCFC single cell colonies, suggesting that PCFCs have the potential to differentiate into GH{sup +} cells. Together, these data show that the pituitary contains a rare clonogenic population which may correspond to the somatotrope/lactotrope progenitors suggested by previous experiments.

  5. Extramedullary hematopoiesis in renal allograft

    PubMed Central

    Chen, Guilan; Ali, Reza; Shuldberg, Mark M.; Bastani, Bahar; Brink, David S.

    2013-01-01

    Extramedullary hematopoiesis (EMH), defined as the presence of hematopoietic elements outside of the medullary cavity of bone, has been reported in patients with various hematopoietic neoplasms including myelofibrosis. EMH commonly occurs in the liver and spleen (resulting in hepatosplenomegaly) and uncommonly involves the kidney. EMH involving the allograft kidney has not been reported in English literature. Herein, we report the first case of EMH in allograft kidney in a patient with myelofibrosis. The clinical and pathological findings are described. Through comparison of the medullary neoplastic infiltrate with the renal allograft infiltrate, we postulate the neoplastic nature of the infiltrate in the allograft kidney. PMID:26120442

  6. Alternatively activated macrophages determine repair of the infarcted adult murine heart

    PubMed Central

    Shiraishi, Manabu; Shintani, Yasunori; Shintani, Yusuke; Ishida, Hidekazu; Saba, Rie; Yamaguchi, Atsushi; Adachi, Hideo; Yashiro, Kenta

    2016-01-01

    Alternatively activated (also known as M2) macrophages are involved in the repair of various types of organs. However, the contribution of M2 macrophages to cardiac repair after myocardial infarction (MI) remains to be fully characterized. Here, we identified CD206+F4/80+CD11b+ M2-like macrophages in the murine heart and demonstrated that this cell population predominantly increases in the infarct area and exhibits strengthened reparative abilities after MI. We evaluated mice lacking the kinase TRIB1 (Trib1–/–), which exhibit a selective depletion of M2 macrophages after MI. Compared with control animals, Trib1–/– mice had a catastrophic prognosis, with frequent cardiac rupture, as the result of markedly reduced collagen fibril formation in the infarct area due to impaired fibroblast activation. The decreased tissue repair observed in Trib1–/– mice was entirely rescued by an external supply of M2-like macrophages. Furthermore, IL-1α and osteopontin were suggested to be mediators of M2-like macrophage–induced fibroblast activation. In addition, IL-4 administration achieved a targeted increase in the number of M2-like macrophages and enhanced the post-MI prognosis of WT mice, corresponding with amplified fibroblast activation and formation of more supportive fibrous tissues in the infarcts. Together, these data demonstrate that M2-like macrophages critically determine the repair of infarcted adult murine heart by regulating fibroblast activation and suggest that IL-4 is a potential biological drug for treating MI. PMID:27140396

  7. Long-Term Survival of Photoreceptors Transplanted into the Adult Murine Neural Retina Requires Immune Modulation

    PubMed Central

    West, Emma L.; Pearson, Rachael A.; Barker, Susie E.; Luhmann, Ulrich F. O.; Maclaren, Robert E.; Barber, Amanda C.; Duran, Yanai; Smith, Alexander J.; Sowden, Jane C.; Ali, Robin R.

    2012-01-01

    Stem cell therapy presents an opportunity to replace photoreceptors that are lost as a result of inherited and age-related degenerative disease. We have previously shown that murine postmitotic rod photoreceptor precursor cells, identified by expression of the rod-specific transcription factor Nrl, are able to migrate into and integrate within the adult murine neural retina. However, their long-term survival has yet to be determined. Here, we found that integrated Nrl.gfp+ve photoreceptors were present up to 12 months post-transplantation, albeit in significantly reduced numbers. Surviving cells had rod-like morphology, including inner/outer segments and spherule synapses. In a minority of eyes, we observed an early, marked reduction in integrated photoreceptors within 1 month post-transplantation, which correlated with increased numbers of amoeboid macrophages, indicating acute loss of transplanted cells due to an inflammatory response. In the majority of transplants, similar numbers of integrated cells were observed between 1 and 2 months post-transplantation. By 4 months, however, we observed a significant decrease in integrated cell survival. Macrophages and T cells were present around the transplantation site, indicating a chronic immune response. Immune suppression of recipients significantly increased transplanted photoreceptor survival, indicating that the loss observed in unsuppressed recipients resulted from T cell-mediated host immune responses. Thus, if immune responses are modulated, correctly integrated transplanted photoreceptors can survive for extended periods of time in hosts with partially mismatched H-2 haplotypes. These findings suggest that autologous donor cells are optimal for therapeutic approaches to repair the neural retina, though with immune suppression nonautologous donors may be effective. PMID:20857496

  8. Noncoding Regulatory RNAs in Hematopoiesis.

    PubMed

    Jeong, M; Goodell, M A

    2016-01-01

    Hematopoiesis is a dynamic process in which blood cells are continuously generated from hematopoietic stem cells (HSCs). The regulatory mechanisms controlling HSC fate have been studied extensively over the past several decades. Although many protein-coding genes have been shown to regulate hematopoietic differentiation, additional levels of HSC regulation are not well studied. Advances in deep sequencing have revealed many new classes of regulatory noncoding RNAs (ncRNAs), such as enhancer RNAs and antisense ncRNAs. Functional analysis of some of these ncRNAs has provided insights into the molecular mechanisms that regulate hematopoietic development and disease. In this review, we summarize recent advances in our understanding of functional regulatory ncRNAs associated with hematopoietic self-renewal and differentiation, as well as those dysregulated ncRNAs involved in hematologic malignancies. PMID:27137659

  9. Long noncoding RNAs in hematopoiesis

    PubMed Central

    Zhang, Xu; Hu, Wenqian

    2016-01-01

    Mammalian development is under tight control to ensure precise gene expression. Recent studies reveal a new layer of regulation of gene expression mediated by long noncoding RNAs. These transcripts are longer than 200nt that do not have functional protein coding capacity. Interestingly, many of these long noncoding RNAs are expressed with high specificity in different types of cells, tissues, and developmental stages in mammals, suggesting that they may have functional roles in diverse biological processes. Here, we summarize recent findings of long noncoding RNAs in hematopoiesis, which is one of the best-characterized mammalian cell differentiation processes. Then we provide our own perspectives on future studies of long noncoding RNAs in this field. PMID:27508063

  10. Autophagy Sustains Hematopoiesis Through Targeting Notch.

    PubMed

    Cao, Yan; Cai, Jinyang; Zhang, Suping; Yuan, Na; Fang, Yixuan; Wang, Zhijian; Li, Xin; Cao, Dan; Xu, Fei; Lin, Weiwei; Song, Lin; Wang, Zhen; Wang, Jian; Xu, Xiaoxiao; Zhang, Yi; Zhao, Wenli; Hu, Shaoyan; Zhang, Xueguang; Wang, Jianrong

    2015-11-15

    Autophagy is required for hematopoietic stem cell multilineage differentiation, but the underlying mechanism is unknown. Using a conditional mouse model and human leukemia cells, we uncovered a mechanistic link between autophagy and hematopoietic stem cell differentiation. Loss of autophagy in mouse hematopoietic stem cells diminished the bone marrow generation of functional blood cells, in particular lymphocytes, and resulted in a leukemic phenotype and elevated Notch signaling. Physiological autophagy activity in mice was inversely correlated with Notch signaling during adult hematopoietic stem cell differentiation, while pathologically low autophagy was associated with upregulated Notch signaling in dysfunctional hematopoietic stem cells of acute leukemia patients. Furthermore, we show that autophagy directly degraded intracellular Notch, the active form of Notch receptor cleaved from the full-length Notch molecule by γ-secretase. Finally, we show that hematopoietic multilineage differentiation potential was restored in autophagy defective hematopoietic stem and progenitor cells when their Notch signaling was abrogated either pharmacologically with γ-secretase inhibitor DAPT or genetically with RNA interference of Notch effector RBPJ. Hence, we propose that autophagy sustains hematopoiesis by direct targeting Notch. PMID:26178296

  11. Hematopoiesis and hematopoietic organs in arthropods.

    PubMed

    Grigorian, Melina; Hartenstein, Volker

    2013-03-01

    Hemocytes (blood cells) are motile cells that move throughout the extracellular space and that exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and the body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self-renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review, we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  12. Hematopoiesis and Hematopoietic Organs in Arthropods

    PubMed Central

    Grigorian, Melina; Hartenstein, Volker

    2013-01-01

    Hemocytes (blood cells) are motile cells moving throughout the extracellular space and exist in all clades of the animal kingdom. Hemocytes play an important role in shaping the extracellular environment and in the immune response. Developmentally, hemocytes are closely related to the epithelial cells lining the vascular system (endothelia) and body cavity (mesothelia). In vertebrates and insects, common progenitors, called hemangioblasts, give rise to the endothelia and blood cells. In the adult animal, many differentiated hemocytes seem to retain the ability to proliferate; however, in most cases investigated closely, the bulk of hemocyte proliferation takes place in specialized hematopoietic organs. Hematopoietic organs provide an environment where undifferentiated blood stem cells are able to self renew, and at the same time generate offspring that differentiate into different blood cell types. Hematopoiesis in vertebrates, taking place in the bone marrow, has been subject to intensive research by immunologists and stem cell biologists. Much less is known about blood cell formation in invertebrate animals. In this review we will survey structural and functional properties of invertebrate hematopoietic organs, with a main focus on insects and other arthropod taxa. We will then discuss similarities, at the molecular and structural level, that are apparent when comparing the development of blood cells in hematopoietic organs of vertebrates and arthropods. Our comparative review is intended to elucidate aspects of the biology of blood stem cells that are more easily missed when focusing on one or a few model species. PMID:23319182

  13. The Proteome of Native Adult Müller Glial Cells From Murine Retina*

    PubMed Central

    Hauser, Alexandra; Lepper, Marlen Franziska; Mayo, Rebecca

    2016-01-01

    To date, the proteomic profiling of Müller cells, the dominant macroglia of the retina, has been hampered because of the absence of suitable enrichment methods. We established a novel protocol to isolate native, intact Müller cells from adult murine retinae at excellent purity which retain in situ morphology and are well suited for proteomic analyses. Two different strategies of sample preparation - an in StageTips (iST) and a subcellular fractionation approach including cell surface protein profiling were used for quantitative liquid chromatography-mass spectrometry (LC-MSMS) comparing Müller cell-enriched to depleted neuronal fractions. Pathway enrichment analyses on both data sets enabled us to identify Müller cell-specific functions which included focal adhesion kinase signaling, signal transduction mediated by calcium as second messenger, transmembrane neurotransmitter transport and antioxidant activity. Pathways associated with RNA processing, cellular respiration and phototransduction were enriched in the neuronal subpopulation. Proteomic results were validated for selected Müller cell genes by quantitative real time PCR, confirming the high expression levels of numerous members of the angiogenic and anti-inflammatory annexins and antioxidant enzymes (e.g. paraoxonase 2, peroxiredoxin 1, 4 and 6). Finally, the significant enrichment of antioxidant proteins in Müller cells was confirmed by measurements on vital retinal cells using the oxidative stress indicator CM-H2DCFDA. In contrast to photoreceptors or bipolar cells, Müller cells were most efficiently protected against H2O2-induced reactive oxygen species formation, which is in line with the protein repertoire identified in the proteomic profiling. Our novel approach to isolate intact glial cells from adult retina in combination with proteomic profiling enabled the identification of novel Müller glia specific proteins, which were validated as markers and for their functional impact in glial

  14. The Proteome of Native Adult Müller Glial Cells From Murine Retina.

    PubMed

    Grosche, Antje; Hauser, Alexandra; Lepper, Marlen Franziska; Mayo, Rebecca; von Toerne, Christine; Merl-Pham, Juliane; Hauck, Stefanie M

    2016-02-01

    To date, the proteomic profiling of Müller cells, the dominant macroglia of the retina, has been hampered because of the absence of suitable enrichment methods. We established a novel protocol to isolate native, intact Müller cells from adult murine retinae at excellent purity which retain in situ morphology and are well suited for proteomic analyses. Two different strategies of sample preparation - an in StageTips (iST) and a subcellular fractionation approach including cell surface protein profiling were used for quantitative liquid chromatography-mass spectrometry (LC-MSMS) comparing Müller cell-enriched to depleted neuronal fractions. Pathway enrichment analyses on both data sets enabled us to identify Müller cell-specific functions which included focal adhesion kinase signaling, signal transduction mediated by calcium as second messenger, transmembrane neurotransmitter transport and antioxidant activity. Pathways associated with RNA processing, cellular respiration and phototransduction were enriched in the neuronal subpopulation. Proteomic results were validated for selected Müller cell genes by quantitative real time PCR, confirming the high expression levels of numerous members of the angiogenic and anti-inflammatory annexins and antioxidant enzymes (e.g. paraoxonase 2, peroxiredoxin 1, 4 and 6). Finally, the significant enrichment of antioxidant proteins in Müller cells was confirmed by measurements on vital retinal cells using the oxidative stress indicator CM-H2DCFDA. In contrast to photoreceptors or bipolar cells, Müller cells were most efficiently protected against H2O2-induced reactive oxygen species formation, which is in line with the protein repertoire identified in the proteomic profiling. Our novel approach to isolate intact glial cells from adult retina in combination with proteomic profiling enabled the identification of novel Müller glia specific proteins, which were validated as markers and for their functional impact in glial

  15. Renal Bleeding Due to Extramedullary Hematopoiesis in a Patient With Chronic Myelogenous Leukemia*

    PubMed Central

    Zettner, Stephanie; Mistry, Sandeep G.

    2014-01-01

    Chronic myelogenous leukemia (CML) is a myeloproliferative disorder that normally presents in middle-aged adults. Renal infiltration and extramedullary hematopoiesis in renal tissue has been rarely reported. This case report presents a patient with CML and renal insufficiency who developed gross hematuria. Efforts at controlling the hematuria led to a cascade of events propelled by the underlying disorder that ultimately led to a radical nephrectomy, multiorgan failure, and prolonged hospitalization. We suggest that management of gross hematuria in clinically stable patients with CML, suspected of having extramedullary hematopoiesis, should prioritize treatment of the myeloproliferative disorder over efforts to control bleeding. PMID:26958483

  16. Portal hypertension and ascites in extramedullary hematopoiesis.

    PubMed

    Amarapurkar, Pooja; Parekh, Sunil; Amarapurkar, Anjali; Amarapurkar, Deepak

    2012-06-01

    Myeloproliferative diseases (MPD) are clonal stem cell disorders which mainly include polycythemia vera (PV), essential thrombocythemia (ET), and idiopathic myelofibrosis (IMF). They are characterized by leucocytosis, thrombocytosis, erythrocytosis, splenomegaly, and bone marrow hypercellularity. This might also result in extramedullary hematopoiesis. Abdominal manifestation has been recognized as a feature of these disorders. Splenomegaly and hepatomegaly are fairly common as opposed to ascites which is rare. The MPDs mainly affect the hepatic circulatory systems. The common hepatic manifestations are Budd-Chiari syndrome (BCS), portal vein thrombosis (PVT), and nodular regenerative hyperplasia. A few other features seen in MPDs are caused by extramedullary hematopoiesis, increased hepatic blood flow, and secondary hemosiderosis from multiple blood transfusions. Portal hypertension is found in up to 7% of patients. We report a case of portal hypertension with ascites in a patient with extramedullary hematopoiesis treated with transjugular intrahepatic portocaval shunt (TIPS). PMID:25755427

  17. Posterior mediastinal extramedullary hematopoiesis secondary to hypoxia.

    PubMed

    Solazzo, A; D'Auria, V; Moccia, L G; Vatrella, A; Bocchino, M; Rea, G

    2016-05-01

    Two mediastinal masses were incidentally detected at high resolution computed tomography (HRCT) of a 72 year-old male patient, former smoker, affected by chronic obstructive pulmonary disease with worsening dyspnea and 2-year medical history of polycythemia secondary to hypoxia. Integration with a multidetector computed tomography (MDCT) scan after administration of intravenous injection contrast medium showed slightly inhomogeneous increase of enhancement of masses, suggesting in the first case potential malignancy. Diagnosis of extramedullary hematopoiesis was achieved by fine needle aspiration citology (FNAC). Extramedullary hematopoiesis must be considered in differential diagnosis in patients with medical history of polycythemia and severe hypoxia. PMID:27326388

  18. Posterior mediastinal extramedullary hematopoiesis secondary to hypoxia

    PubMed Central

    Solazzo, A; D’Auria, V; Moccia, LG; Vatrella, A; Bocchino, M; Rea, G

    2016-01-01

    Two mediastinal masses were incidentally detected at high resolution computed tomography (HRCT) of a 72 year-old male patient, former smoker, affected by chronic obstructive pulmonary disease with worsening dyspnea and 2-year medical history of polycythemia secondary to hypoxia. Integration with a multidetector computed tomography (MDCT) scan after administration of intravenous injection contrast medium showed slightly inhomogeneous increase of enhancement of masses, suggesting in the first case potential malignancy. Diagnosis of extramedullary hematopoiesis was achieved by fine needle aspiration citology (FNAC). Extramedullary hematopoiesis must be considered in differential diagnosis in patients with medical history of polycythemia and severe hypoxia. PMID:27326388

  19. Abnormal hematopoiesis in Gab2 mutant mice

    PubMed Central

    Zhang, Yi; Diaz-Flores, Ernesto; Li, Geqiang; Wang, Zhengqi; Kang, Zizhen; Haviernikova, Eleonora; Rowe, Sara; Qu, Cheng-Kui; Tse, William; Shannon, Kevin M.

    2007-01-01

    Gab2 is an important adapter molecule for cytokine signaling. Despite its major role in signaling by receptors associated with hematopoiesis, the role of Gab2 in hematopoiesis has not been addressed. We report that despite normal numbers of peripheral blood cells, bone marrow cells, and c-Kit+Lin−Sca-1+ (KLS) cells, Gab2-deficient hematopoietic cells are deficient in cytokine responsiveness. Significant reductions in the number of colony-forming units in culture (CFU-C) in the presence of limiting cytokine concentrations were observed, and these defects could be completely corrected by retroviral complementation. In earlier hematopoiesis, Gab2-deficient KLS cells isolated in vitro responded poorly to hematopoietic growth factors, resulting in an up to 11-fold reduction in response to a cocktail of stem cell factor, flt3 ligand, and thrombopoietin. Gab2-deficient c-Kit+Lin− cells also demonstrate impaired activation of extracellular signal-regulated kinase (ERK) and S6 in response to IL-3, which supports defects in activating the phosphatidylinositol-3 kinase (PI-3K) and mitogen-associated protein kinase (MAPK) signaling cascades. Associated with the early defects in cytokine response, competitive transplantation of Gab2−/− bone marrow cells resulted in defective long-term multilineage repopulation. Therefore, we demonstrate that Gab2 adapter function is intrinsically required for hematopoietic cell response to early-acting cytokines, resulting in defective hematopoiesis in Gab2-deficient mice. PMID:17374739

  20. Hematopoiesis In The Equine Fetal Liver Suggests Immune Preparedness

    PubMed Central

    Battista, JM; Tallmadge, RL; Stokol, T; Felippe, MJB

    2014-01-01

    We investigated how the equine fetus prepares its pre-immune humoral repertoire for an imminent exposure to pathogens in the neonatal period, particularly how the primary hematopoietic organs are equipped to support B cell hematopoiesis and immunoglobulin (Ig) diversity. We demonstrated that the liver and the bone marrow at approximately 100 days of gestation (DG) are active sites of hematopoiesis based on the expression of signature mRNA (c-KIT, CD34, IL7R, CXCL12, IRF8, PU.1, PAX5, NOTCH1, GATA1, CEBPA) and protein markers (CD34, CD19, IgM, CD3, CD4, CD5, CD8, CD11b, CD172A) of hematopoietic development and leukocyte differentiation molecules, respectively. To verify Ig diversity achieved during the production of B cells, V(D)J segments were sequenced in primary lymphoid organs of the equine fetus and adult horse, revealing that similar heavy chain VDJ segments and CDR3 lengths were most frequently used independent of life stage. In contrast, different lambda light chain segments were predominant in equine fetal compared to adult stage and, surprisingly, the fetus had less restricted use of variable gene segments to construct the lambda chain. Fetal Igs also contained elements of sequence diversity, albeit to a smaller degree than that of the adult horse. Our data suggest that the B cells produced in the liver and bone marrow of the equine fetus generate a wide repertoire of pre-immune Igs for protection, and the more diverse use of different lambda variable gene segments in fetal life may provide the neonate an opportunity to respond to a wider range of antigens at birth. PMID:25179685

  1. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis.

    PubMed

    López-Hidalgo, Rosa; Ballestín, Raul; Vega, Jessica; Blasco-Ibáñez, José M; Crespo, Carlos; Gilabert-Juan, Javier; Nácher, Juan; Varea, Emilio

    2016-01-01

    Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5'BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5'BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice. PMID

  2. Overexpression of wild-type or mutants forms of CEBPA alter normal human hematopoiesis.

    PubMed

    Quintana-Bustamante, O; Lan-Lan Smith, S; Griessinger, E; Reyal, Y; Vargaftig, J; Lister, T A; Fitzgibbon, J; Bonnet, D

    2012-07-01

    CCAAT/enhancer-binding protein-α (C/EBPα/CEBPA) is mutated in approximately 8% of acute myeloid leukemia (AML) in both familial and sporadic AML and, with FLT3 and NPM1, has received most attention as a predictive marker of outcome in patients with normal karyotype disease. Mutations clustering to either the N- or C-terminal (N- and C-ter) portions of the protein have different consequences on the protein function. In familial cases, the N-ter form is inherited with patients exhibiting long latency period before the onset of overt disease, typically with the acquisition of a C-ter mutation. Despite the essential insights murine models provide the functional consequences of wild-type C/EBPα in human hematopoiesis and how different mutations are involved in AML development have received less attention. Our data underline the critical role of C/EBPα in human hematopoiesis and demonstrate that C/EBPα mutations (alone or in combination) are insufficient to convert normal human hematopoietic stem/progenitor cells into leukemic-initiating cells, although individually each altered normal hematopoiesis. It provides the first insight into the effects of N- and C-ter mutations acting alone and to the combined effects of N/C double mutants. Our results mimicked closely what happens in CEBPA mutated patients. PMID:22371011

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

    PubMed Central

    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. PMID:27081472

  4. Long segment spinal epidural extramedullary hematopoiesis

    PubMed Central

    Garg, Kanwaljeet; Singh, Pankaj Kumar; Singh, Manmohan; Chandra, P. Sarat; Sharma, Bhawani Shankar

    2013-01-01

    Background: Extramedullary hematopoiesis is defined as the formation of blood cells outside the bone marrow. It is a common manifestation of many chronic hemolytic anemias, and typically involves the liver, spleen, and lymph nodes. Only rarely is the spinal epidural space involved. Methods: We describe a 25-year-old male, known to have thalassemia intermedia, who presented with a 1-month history of stiffness and weakness in both lower extremities. On physical examination, he had palpable splenomegaly accompanied by spinal tenderness at the D5 level, weakness in both lower extremities, hyperactive bilateral Patellar and Achilles reflexes with bilateral Babinski responses, and a graded sensory loss to pin appreciation below D5. Results: The magnetic resonance (MR) study revealed a posterior, isointense and soft tissue epidural mass extending from D2 to D12 on both the T1- and T2-weighted images. These findings were consistent with the diagnosis of “red marrow,” and long-segment spinal epidural extramedullary hematopoiesis. Conclusions: Although extramedullary hematopoiesis is rarely encountered within the spinal canal, it should be considered among the differential diagnoses when a posterior compressive thoracic lesion contributes to myelopathy in a patient with a history of thalassemia intermedia and the accompanying chronic hemolytic anemia. PMID:24404404

  5. Autosomal dominant cyclic hematopoiesis: Genetics, phenotype, and natural history

    SciTech Connect

    Palmer, S.E.; Stephens, K.; Dale, D.C.

    1994-09-01

    Autosomal dominant cyclic hematopoiesis (ADCH; cyclic neutropenia) is a rare disorder manifested by transient neutropenia that recurs every three weeks. To facilitate mapping the ADCH gene by genetic linkage analysis, we studied 9 ADCH families with 42 affected individuals. Pedigrees revealed AD inheritance with no evidence for decreased penetrance. Similar intra- and interfamilial variable expression was observed, with no evidence to support heterogeneity. At least 3 families displayed apparent new mutations. Many adults developed chronic neutropenia, while offspring always cycled during childhood. Children displayed recurrent oral ulcers, gingivitis, lymphadenopathy, fever, and skin and other infections with additional symptoms. Interestingly, there were no cases of neonatal infection. Some children required multiple hospitalizations for treatment. Four males under age 18 died of Clostridium sepsis following necrotizing enterocolitis; all had affected mothers. No other deaths due to ADCH were found; most had improvement of symptoms and infections as adults. Adults experienced increased tooth loss prior to age 30 (16 out of 27 adults, with 9 edentulous). No increase in myelodysplasia, malignancy, or congenital anomalies was observed. Recombinant G-CSF treatment resulted in dramatic improvement of symptoms and infections. The results suggest that ADCH is not a benign disorder, especially in childhood, and abdominal pain requires immediate evaluation. Diagnosis of ADCH requires serial blood counts in the proband and at least one CBC in relatives to exclude similar disorders. Genetic counseling requires specific histories as well as CBCs of each family member at risk to determine status regardless of symptom history, especially to assess apparent new mutations.

  6. In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas.

    PubMed

    Tremblay, Jacob R; LeBon, Jeanne M; Luo, Angela; Quijano, Janine C; Wedeken, Lena; Jou, Kevin; Riggs, Arthur D; Tirrell, David A; Ku, H Teresa

    2016-01-01

    Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. However, it is still unknown whether stem and progenitor cells exist in the adult pancreas. Research strategies using cre-lox lineage-tracing in adult mice have yielded results that either support or refute the idea that beta cells can be generated from the ducts, the presumed location where adult pancreatic progenitors may reside. These in vivo cre-lox lineage-tracing methods, however, cannot answer the questions of self-renewal and multi-lineage differentiation-two criteria necessary to define a stem cell. To begin addressing this technical gap, we devised 3-dimensional colony assays for pancreatic progenitors. Soon after our initial publication, other laboratories independently developed a similar, but not identical, method called the organoid assay. Compared to the organoid assay, our method employs methylcellulose, which forms viscous solutions that allow the inclusion of extracellular matrix proteins at low concentrations. The methylcellulose-containing assays permit easier detection and analyses of progenitor cells at the single-cell level, which are critical when progenitors constitute a small sub-population, as is the case for many adult organ stem cells. Together, results from several laboratories demonstrate in vitro self-renewal and multi-lineage differentiation of pancreatic progenitor-like cells from mice. The current protocols describe two methylcellulose-based colony assays to characterize mouse pancreatic progenitors; one contains a commercial preparation of murine extracellular matrix proteins and the other an artificial extracellular matrix protein known as a laminin hydrogel. The techniques shown here are 1) dissociation of the pancreas and sorting of CD133(+)Sox9/EGFP(+) ductal cells from adult mice, 2) single cell manipulation of the sorted cells, 3) single colony analyses using microfluidic q

  7. Impaired Hematopoiesis and Disrupted Monocyte/Macrophage Homeostasis in Mucopolysaccharidosis Type I Mice.

    PubMed

    Viana, Gustavo Monteiro; Buri, Marcus Vinícius; Paredes-Gamero, Edgar Julian; Martins, Ana Maria; D'Almeida, Vânia

    2016-03-01

    Mucopolysaccharidosis type I (MPS I) is a rare autosomal recessive disease caused by alpha-L-iduronidase deficiency in which heparan and dermatan sulfate degradation is compromised. Besides primary lysosomal glycosaminoglycan accumulation, further changes in cellular functions have also been described in several murine MPS models. Herein, we evaluated alterations in hematopoiesis and its implications on the production of mature progeny in a MPS I murine model. Despite the significant increase in hematopoietic stem cells, a reduction in common myeloid progenitors and granulocyte-macrophage progenitor cells was observed in Idua -/- mice bone marrow. Furthermore, no alterations in number, viability nor activation of cell death mechanisms were observed in Idua -/- mice mature macrophages but they presented higher sensitivity to apoptotic induction after staurosporine treatment. In addition, changes in Ca(2+) signaling and a reduction in phagocytosis ability were also found. In summary, our results revealed significant intracellular changes in mature Idua -/- macrophages related to alterations in Idua -/- mice hematopoiesis, revealing a disruption in cell homeostasis. These results provide new insights into physiopathology of MPS I. PMID:26235607

  8. Fate analysis of adult hippocampal progenitors in a murine model of fetal alcohol spectrum disorder (FASD).

    PubMed

    Kajimoto, Kenta; Allan, Andrea; Cunningham, Lee Anna

    2013-01-01

    Prenatal alcohol exposure can lead to fetal alcohol spectrum disorder (FASD) and associated behavioral impairments that may be linked to disruptions in adult hippocampal neurogenesis. Social and physical enrichment has been proposed as a potential therapeutic approach toward reversing behavioral deficits associated with FASD and is also a potent stimulator of adult hippocampal neurogenesis. In the present study, we utilized a genetic fate mapping approach in nestin-CreER(T2)/YFP bitransgenic mice to identify the stage-specific impact of prenatal alcohol exposure on the stepwise maturation of adult hippocampal progenitors. Using a limited alcohol access "drinking-in-the-dark" model of FASD, we confirm previous findings that moderate prenatal alcohol exposure has no effect on adult neurogenesis under standard housing conditions, but abolishes the neurogenic response to enriched environment (EE). Furthermore, we demonstrate that this effect is primarily due to failed EE-mediated survival of postmitotic neurons. Finally, we demonstrate that the neurogenic deficit is associated with impaired spatial pattern recognition, as demonstrated by delayed learning of FASD-EE mice in an A-B contextual discrimination task. These results identify a potential maturational stage-specific mechanism(s) underlying impaired neurogenic function in a preclinical model of FASD, and provide a basis for testing regulatory pathways in this model through conditional and inducible manipulation of gene expression in the adult hippocampal progenitor population. PMID:24040071

  9. Fate Analysis of Adult Hippocampal Progenitors in a Murine Model of Fetal Alcohol Spectrum Disorder (FASD)

    PubMed Central

    Kajimoto, Kenta; Allan, Andrea; Cunningham, Lee Anna

    2013-01-01

    Prenatal alcohol exposure can lead to fetal alcohol spectrum disorder (FASD) and associated behavioral impairments that may be linked to disruptions in adult hippocampal neurogenesis. Social and physical enrichment has been proposed as a potential therapeutic approach toward reversing behavioral deficits associated with FASD and is also a potent stimulator of adult hippocampal neurogenesis. In the present study, we utilized a genetic fate mapping approach in nestin-CreERT2/YFP bitransgenic mice to identify the stage-specific impact of prenatal alcohol exposure on the stepwise maturation of adult hippocampal progenitors. Using a limited alcohol access “drinking-in-the-dark” model of FASD, we confirm previous findings that moderate prenatal alcohol exposure has no effect on adult neurogenesis under standard housing conditions, but abolishes the neurogenic response to enriched environment (EE). Furthermore, we demonstrate that this effect is primarily due to failed EE-mediated survival of postmitotic neurons. Finally, we demonstrate that the neurogenic deficit is associated with impaired spatial pattern recognition, as demonstrated by delayed learning of FASD-EE mice in an A–B contextual discrimination task. These results identify a potential maturational stage-specific mechanism(s) underlying impaired neurogenic function in a preclinical model of FASD, and provide a basis for testing regulatory pathways in this model through conditional and inducible manipulation of gene expression in the adult hippocampal progenitor population. PMID:24040071

  10. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis

    PubMed Central

    López-Hidalgo, Rosa; Ballestín, Raul; Vega, Jessica; Blasco-Ibáñez, José M.; Crespo, Carlos; Gilabert-Juan, Javier; Nácher, Juan; Varea, Emilio

    2016-01-01

    Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5′BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5′BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice

  11. Ablating hedgehog signaling in tenocytes during development impairs biomechanics and matrix organization of the adult murine patellar tendon enthesis

    PubMed Central

    Aschbacher‐Smith, Lindsey; Lu, Yinhui; Dyment, Nathaniel A.; Liu, Chia‐Feng; Liu, Han; Wylie, Chris; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Jiang, Rulang; Butler, David L.

    2015-01-01

    ABSTRACT Restoring the native structure of the tendon enthesis, where collagen fibers of the midsubstance are integrated within a fibrocartilaginous structure, is problematic following injury. As current surgical methods fail to restore this region adequately, engineers, biologists, and clinicians are working to understand how this structure forms as a prerequisite to improving repair outcomes. We recently reported on the role of Indian hedgehog (Ihh), a novel enthesis marker, in regulating early postnatal enthesis formation. Here, we investigate how inactivating the Hh pathway in tendon cells affects adult (12‐week) murine patellar tendon (PT) enthesis mechanics, fibrocartilage morphology, and collagen fiber organization. We show that ablating Hh signaling resulted in greater than 100% increased failure insertion strain (0.10 v. 0.05 mm/mm, p<0.01) as well as sub‐failure biomechanical deficiencies. Although collagen fiber orientation appears overtly normal in the midsubstance, ablating Hh signaling reduces mineralized fibrocartilage by 32%, leading to less collagen embedded within mineralized tissue. Ablating Hh signaling also caused collagen fibers to coalesce at the insertion, which may explain in part the increased strains. These results indicate that Ihh signaling plays a critical role in the mineralization process of fibrocartilaginous entheses and may be a novel therapeutic to promote tendon‐to‐bone healing. © 2015 The Authors. Journal of Orthopaedic Research published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 33:1142–1151, 2015. PMID:25807894

  12. Intracranial Extramedullary Hematopoiesis in Beta-Thalassemia

    PubMed Central

    Karki, Bivek; Tamrakar, Karuna; Wu, Yuan-Kui

    2012-01-01

    Extramedullary hematopoiesis (EMH) represents tumor-like proliferation of hemopoietic tissue which complicates chronic hemoglobinopathy. Intracranial EMH is an extremely rare occurrence. Magnetic resonance imaging (MRI) offers a precise diagnosis. It is essential to distinguish EMH from other extradural central nervous system tumors, because treatment and prognosis are totally different. Herein, we report the imaging findings of beta-thalassemia in a 13-year-old boy complaining of weakness of left side of the body and gait disturbance; CT and MRI revealed an extradural mass in the right temporoparietal region. PMID:22438693

  13. Understanding leukemic hematopoiesis as a complex adaptive system

    PubMed Central

    Thomas, Xavier

    2015-01-01

    Normal and abnormal hematopoiesis is working as a complex adaptive system. From this perspective, the development and the behavior of hematopoietic cell lineages appear as a balance between normal and abnormal hematopoiesis in the setting of a functioning or malfunctioning microenvironment under the control of the immune system and the influence of hereditary and environmental events. PMID:26516407

  14. Mutant U2AF1 Expression Alters Hematopoiesis and Pre-mRNA Splicing In Vivo

    PubMed Central

    Shirai, Cara Lunn; Ley, James N.; White, Brian S.; Kim, Sanghyun; Tibbitts, Justin; Shao, Jin; Ndonwi, Matthew; Wadugu, Brian; Duncavage, Eric J.; Okeyo-Owuor, Theresa; Liu, Tuoen; Griffith, Malachi; McGrath, Sean; Magrini, Vincent; Fulton, Robert S.; Fronick, Catrina; O’Laughlin, Michelle; Graubert, Timothy A.; Walter, Matthew J.

    2015-01-01

    SUMMARY Heterozygous somatic mutations in the spliceosome gene U2AF1 occur in ~11% of patients with myelodysplastic syndromes (MDS), the most common adult myeloid malignancy. It is unclear how these mutations contribute to disease. We examined in vivo hematopoietic consequences of the most common U2AF1 mutation using a doxycycline-inducible transgenic mouse model. Mice expressing mutant U2AF1(S34F) display altered hematopoiesis and changes in pre-mRNA splicing in hematopoietic progenitor cells by whole transcriptome analysis (RNA-seq). Integration with human RNA-seq datasets determined that common mutant U2AF1-induced splicing alterations are enriched in RNA processing genes, ribosomal genes, and recurrently-mutated MDS and acute myeloid leukemia-associated genes. These findings support the hypothesis that mutant U2AF1 alters downstream gene isoform expression, thereby contributing to abnormal hematopoiesis in MDS patients. PMID:25965570

  15. The Role of Menin in Hematopoiesis

    PubMed Central

    Maillard, Ivan; Hess, Jay L.

    2010-01-01

    In the hematopoietic system, menin was found to interact with MLL, a large protein encoded by the mixed linage leukemia gene that acts as a histone H3 merhyltransferase. The MLL gene is a recurrent target for translocations in both acute myeloid and acute lymphoid leukemias. MLL gene rearrangements involve a variety of translocation partners, giving rise to MLL fusion proteins whose transforming ability is mediated through upregulated expression of Homeobox (Hox) genes as well as other targets. Recent work indicates that menin is an essential partner of MLL fusion proteins in leukemic cells and that it regulates normal hematopoiesis. In the absence of menin, steady-state hematopoiesis is largely preserved; however, menin-deficient hematopoietic stem cells are markedly deficient in situations of hematopoietic stress, such as during recovery after bone marrow transplantation. In leukemias driven by MLL fusion proteins, menin is essential for transformation and growth of the malignant cells. Thus, menin-MLL interactions represent a promising therapeutic target in leukemias with MLL rearrangements. PMID:20175452

  16. DNA methylation in normal and malignant hematopoiesis.

    PubMed

    Celik, Hamza; Kramer, Ashley; Challen, Grant A

    2016-06-01

    The study of DNA methylation has been a rapidly expanding field since its dawn in the 1960s. DNA methylation is an epigenetic modification that plays a crucial role in guiding the differentiation of stem cells to their destined lineage, and in maintaining tissue homeostasis. Moreover, aberrant DNA methylation has been well characterized as a significant contributing factor in the pathogenesis of a variety of cancers. Hematopoiesis is a process that is uniquely susceptible to epigenetic changes due to the small pool of actively cycling stem cells that give rise to the entire mature immune-hematopoietic system. Mutations in DNA methyltransferase enzymes have been shown to be initiating events in the development of hematological malignancies such as acute myeloid leukemia and, therefore, have become targets for improved diagnostics and therapy. The spatial and temporal regulation of DNA methylation in the hematopoietic developmental hierarchy is critical to hematopoietic homeostasis. An improved understanding of the roles that DNA methylation plays in normal and malignant hematopoiesis will have a significant impact on the future of regenerative stem cell therapy and clinical treatment of hematopoietic malignancies. This review aims to highlight current developments in the field and prioritize future research directions. PMID:26943352

  17. Differential vascular permeability along the forebrain ventricular neurogenic niche in the adult murine brain.

    PubMed

    Colín-Castelán, Dannia; Ramírez-Santos, Jesús; Gutiérrez-Ospina, Gabriel

    2016-02-01

    Adult neurogenesis is influenced by blood-borne factors. In this context, greater or lesser vascular permeability along neurogenic niches would expose differentially neural stem cells (NSCs), transit amplifying cells (TACs), and neuroblasts to such factors. Here we evaluate endothelial cell morphology and vascular permeability along the forebrain neurogenic niche in the adult brain. Our results confirm that the subventricular zone (SVZ) contains highly permeable, discontinuous blood vessels, some of which allow the extravasation of molecules larger than those previously reported. In contrast, the rostral migratory stream (RMS) and the olfactory bulb core (OBc) display mostly impermeable, continuous blood vessels. These results imply that NSCs, TACs, and neuroblasts located within the SVZ are exposed more readily to blood-borne molecules, including those with very high molecular weights, than those positioned along the RMS and the OBc, subregions in which every stage of neurogenesis also takes place. These observations suggest that the existence of specialized vascular niches is not a precondition for neurogenesis to occur; specialized vascular beds might be essential for keeping high rates of proliferation and/or differential differentiation of neural precursors located at distinct domains. PMID:26492830

  18. PDGFRα demarcates the cardiogenic clonogenic Sca1+ stem/progenitor cell in adult murine myocardium.

    PubMed

    Noseda, Michela; Harada, Mutsuo; McSweeney, Sara; Leja, Thomas; Belian, Elisa; Stuckey, Daniel J; Abreu Paiva, Marta S; Habib, Josef; Macaulay, Iain; de Smith, Adam J; al-Beidh, Farah; Sampson, Robert; Lumbers, R Thomas; Rao, Pulivarthi; Harding, Sian E; Blakemore, Alexandra I F; Jacobsen, Sten Eirik; Barahona, Mauricio; Schneider, Michael D

    2015-01-01

    Cardiac progenitor/stem cells in adult hearts represent an attractive therapeutic target for heart regeneration, though (inter)-relationships among reported cells remain obscure. Using single-cell qRT-PCR and clonal analyses, here we define four subpopulations of cardiac progenitor/stem cells in adult mouse myocardium all sharing stem cell antigen-1 (Sca1), based on side population (SP) phenotype, PECAM-1 (CD31) and platelet-derived growth factor receptor-α (PDGFRα) expression. SP status predicts clonogenicity and cardiogenic gene expression (Gata4/6, Hand2 and Tbx5/20), properties segregating more specifically to PDGFRα(+) cells. Clonal progeny of single Sca1(+) SP cells show cardiomyocyte, endothelial and smooth muscle lineage potential after cardiac grafting, augmenting cardiac function although durable engraftment is rare. PDGFRα(-) cells are characterized by Kdr/Flk1, Cdh5, CD31 and lack of clonogenicity. PDGFRα(+)/CD31(-) cells derive from cells formerly expressing Mesp1, Nkx2-5, Isl1, Gata5 and Wt1, distinct from PDGFRα(-)/CD31(+) cells (Gata5 low; Flk1 and Tie2 high). Thus, PDGFRα demarcates the clonogenic cardiogenic Sca1(+) stem/progenitor cell. PMID:25980517

  19. PDGFRα demarcates the cardiogenic clonogenic Sca1+ stem/progenitor cell in adult murine myocardium

    PubMed Central

    Noseda, Michela; Harada, Mutsuo; McSweeney, Sara; Leja, Thomas; Belian, Elisa; Stuckey, Daniel J.; Abreu Paiva, Marta S.; Habib, Josef; Macaulay, Iain; de Smith, Adam J.; al-Beidh, Farah; Sampson, Robert; Lumbers, R. Thomas; Rao, Pulivarthi; Harding, Sian E.; Blakemore, Alexandra I. F.; Eirik Jacobsen, Sten; Barahona, Mauricio; Schneider, Michael D.

    2015-01-01

    Cardiac progenitor/stem cells in adult hearts represent an attractive therapeutic target for heart regeneration, though (inter)-relationships among reported cells remain obscure. Using single-cell qRT–PCR and clonal analyses, here we define four subpopulations of cardiac progenitor/stem cells in adult mouse myocardium all sharing stem cell antigen-1 (Sca1), based on side population (SP) phenotype, PECAM-1 (CD31) and platelet-derived growth factor receptor-α (PDGFRα) expression. SP status predicts clonogenicity and cardiogenic gene expression (Gata4/6, Hand2 and Tbx5/20), properties segregating more specifically to PDGFRα+ cells. Clonal progeny of single Sca1+ SP cells show cardiomyocyte, endothelial and smooth muscle lineage potential after cardiac grafting, augmenting cardiac function although durable engraftment is rare. PDGFRα− cells are characterized by Kdr/Flk1, Cdh5, CD31 and lack of clonogenicity. PDGFRα+/CD31− cells derive from cells formerly expressing Mesp1, Nkx2-5, Isl1, Gata5 and Wt1, distinct from PDGFRα−/CD31+ cells (Gata5 low; Flk1 and Tie2 high). Thus, PDGFRα demarcates the clonogenic cardiogenic Sca1+ stem/progenitor cell. PMID:25980517

  20. Pharmacological analysis of epithelial chloride secretion mechanisms in adult murine airways.

    PubMed

    Gianotti, Ambra; Ferrera, Loretta; Philp, Amber R; Caci, Emanuela; Zegarra-Moran, Olga; Galietta, Luis J V; Flores, Carlos A

    2016-06-15

    Defective epithelial chloride secretion occurs in humans with cystic fibrosis (CF), a genetic defect due to loss of function of CFTR, a cAMP-activated chloride channel. In the airways, absence of an active CFTR causes a severe lung disease. In mice, genetic ablation of CFTR function does not result in similar lung pathology. This may be due to the expression of an alternative chloride channel which is activated by calcium. The most probable protein performing this function is TMEM16A, a calcium-activated chloride channel (CaCC). Our aim was to assess the relative contribution of CFTR and TMEM16A to chloride secretion in adult mouse trachea. For this purpose we tested pharmacological inhibitors of chloride channels in normal and CF mice. The amplitude of the cAMP-activated current was similar in both types of animals and was not affected by a selective CFTR inhibitor. In contrast, a CaCC inhibitor (CaCCinh-A01) strongly blocked the cAMP-activated current as well as the calcium-activated chloride secretion triggered by apical UTP. Although control experiments revealed that CaCCinh-A01 also shows inhibitory activity on CFTR, our results indicate that transepithelial chloride secretion in adult mouse trachea is independent of CFTR and that another channel, possibly TMEM16A, performs both cAMP- and calcium-activated chloride transport. The prevalent function of a non-CFTR channel may explain the absence of a defect in chloride transport in CF mice. PMID:27063443

  1. Prenatal exposure to lipopolysaccharide results in myocardial remodelling in adult murine offspring

    PubMed Central

    2013-01-01

    Background The epigenetic plasticity hypothesis indicates that pregnancy exposure may result in adult-onset diseases, including hypertension, diabetes and cardiovascular disease, in offspring. In a previous study, we discovered that prenatal exposure to inflammatory stimulants, such as lipopolysaccharides (LPS), could lead to hypertension in adult rat offspring. In the present study, we further demonstrate that maternal inflammation induces cardiac hypertrophy and dysfunction via ectopic over-expression of nuclear transcription factor κB (NF- κB), and pyrrolidine dithiocarbamate (PDTC) can protect cardiac function by reducing maternal inflammation. Methods Pregnant SD rats were randomly divided into three groups and intraperitoneally injected with a vehicle, LPS (0.79 mg/kg), or LPS (0.79 mg/kg) plus PDTC (100 mg/kg) at 8 to 12 days of gestation. The offspring were raised until 4 and 8 months old, at which point an echocardiographic study was performed. The left ventricular (LV) mass index and apoptosis were examined. Results At 4 months of age, the LPS offspring exhibited augmented posterior wall thickness. These rats displayed left ventricle (LV) hypertrophy and LV diastolic dysfunction as well as a higher apoptotic index, a higher level of Bax and a lower level of Bcl-2 at 8 months of age. The protein levels of NF-κB (p65) in the myocardium of the offspring were measured at this time. NF-κB protein levels were higher in the myocardium of LPS offspring. The offspring that were prenatally treated with PDTC displayed improved signs of blood pressure (BP) and LV hypertrophy. Conclusions Maternal inflammation can induce cardiac hypertrophy in offspring during aging accompanied with hypertension emergence and can be rescued by the maternal administration of PDTC (the inhibitor of NF-κB). PMID:24764457

  2. Glomerular parietal epithelial cells of adult murine kidney undergo EMT to generate cells with traits of renal progenitors.

    PubMed

    Swetha, G; Chandra, Vikash; Phadnis, Smruti; Bhonde, Ramesh

    2011-02-01

    Glomerular parietal epithelial cells (GPECs) are known to revert to embryonic phenotype in response to renal injury. However, the mechanism of de-differentiation in GPECs and the underlying cellular processes are not fully understood. In the present study, we show that cultured GPECs of adult murine kidney undergo epithelial-mesenchymal transition (EMT) to generate cells, which express CD24, CD44 and CD29 surface antigens. Characterization by qRT-PCR and immunostaining of these clonogenic cells demonstrate that they exhibit metastable phenotype with co-expression of both epithelial (cytokeratin-18) and mesenchymal (vimentin) markers. Transcript analysis by qRT-PCR revealed high expression of metanephric mesenchymal (Pax-2, WT-1, Six-1, Eya-1, GDNF) and uteric bud (Hoxb-7, C-Ret) genes in these cells, indicating their bipotent progenitor status. Incubation of GPECs with EMT blocker Prostaglandin E2, resulted in low expression of renal progenitor markers reflecting the correlation between EMT and acquired stemness in these cells. Additional in vitro renal commitment assays confirmed their functional staminality. When injected into E13.5 kidney rudiments, the cells incorporated into the developing kidney primordia and co-culture with E13.5 spinal cord resulted in branching and tubulogenesis in these cells. When implanted under renal capsule of unilaterally nephrectomized mice, these cells differentiated into immature glomeruli and vascular ducts. Our study demonstrates that EMT plays a major role in imparting plasticity to terminally differentiated GPECs by producing metastable cells with traits of kidney progenitors. The present study would improve our understanding on epithelial cell plasticity, furthering our knowledge of its role in renal repair and regeneration. PMID:19840197

  3. Osteomyelosclerosis, anemia and extramedullary hematopoiesis in mice lacking the transcription factor NFATc2

    PubMed Central

    Bauer, Wolfgang; Rauner, Martina; Haase, Michael; Kujawski, Satu; Arabanian, Laleh S.; Habermann, Ivonne; Hofbauer, Lorenz C.; Ehninger, Gerhard; Kiani, Alexander

    2011-01-01

    Background Nuclear factors of activated T cells (NFAT) are transcription factors that are central to cytokine production in activated T cells and regulate the development and differentiation of various tissues. NFATc2 is expressed in hematopoietic stem cells and regulated during myeloid commitment in a lineage-specific manner. The biological role of NFATc2 in hematopoiesis is, however, unclear. Design and Methods In the present study, we analyzed steady-state hematopoiesis in young (<3 months) and old (>12 months) mice lacking NFATc2. Complete blood counts were performed in the peripheral blood, bone marrow and spleen. Using cytological and histological analyses, the blood cell differential was determined. Colony-formation assays were used to determine the differentiation potential of hematopoietic cells. Bone cell cultures were derived from the bone marrow, and bone remodeling markers were determined in the serum. Results NFATc2−/− mice older than 12 months were anemic and thrombocytopenic. The bone marrows of these mice showed a markedly reduced number of hematopoietic cells, of which megakaryocytic and erythroid lineages were most affected. While the number of hematopoietic progenitor cells in NFATc2-deficent bone marrow was reduced, the myeloid differentiation potential of these cells remained intact. Aged NFATc2−/− mice showed ossification of their bone marrow space and developed extramedullary hematopoiesis in the spleen. Ex vivo differentiation assays revealed an intrinsic defect of NFATc2-deficient stromal cells, in which NFATc2−/− osteoblasts differentiated more efficiently than wild-type cells, whereas osteoclast differentiation was impaired. Conclusions Our data suggest that NFATc2 may play a role in the maintenance of steady-state hematopoiesis and bone remodeling in adult organisms. PMID:21750088

  4. Ultrafiltered pig leukocyte extract (IMUNOR) decreases nitric oxide formation and hematopoiesis-stimulating cytokine production in lipopolysaccharide-stimulated RAW 264.7 macrophages.

    PubMed

    Hofer, Michal; Vacek, Antonín; Lojek, Antonín; Holá, Jirina; Streitová, Denisa

    2007-10-01

    A low-molecular-weight (<12 kDa) ultrafiltered pig leukocyte extract, IMUNOR, was tested in experiments in vitro on non-stimulated and lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages in order to assess modulation of nitric oxide (NO) production (measured indirectly as the concentration of nitrites), hematopoiesis-stimulating activity of the supernatant of the macrophage cells (ascertained by counting cell colonies growing from progenitor cells for granulocytes and macrophages (GM-CFC) in vitro), and the release of hematopoiesis-stimulating cytokines. No hematopoiesis-stimulating activity and cytokine or NO production were found in the supernatant of non-stimulated macrophages. It was found that IMUNOR does not influence this status. Supernatant of LPS-stimulated macrophages was characterized by hematopoiesis-stimulating activity, as well as by the presence of nitrites, interleukin-6 (IL-6), and granulocyte colony-stimulating factor (G-CSF). A key role in the hematopoiesis-stimulating activity of the supernatant of LPS-stimulated macrophages could be ascribed to G-CSF since the formation of the colonies could be abrogated nearly completely by monoclonal antibodies against G-CSF. IMUNOR was found to suppress all the mentioned manifestations of the LPS-activated macrophages. When considering these results together with those from our previous in vivo study revealing stimulatory effects of IMUNOR on radiation-suppressed hematopoiesis, a hypothesis may be formulated which postulates a homeostatic role of IMUNOR, consisting in stimulation of impaired immune and hematopoietic systems but also in cutting back the production of proinflammatory mediators in cases of overstimulation which threats with undesirable consequences. PMID:17673152

  5. Genetics, phenotype, and natural history of autosomal dominant cyclic hematopoiesis

    SciTech Connect

    Palmer, S.E. |; Dale, D.C.

    1996-12-30

    Cyclic hematopoiesis (CH, or cyclic neutropenia) is a rare disease manifested by transient severe neutropenia that recurs approximately every 21 days. The hematologic profile of families with the autosomal dominant form (ADCH) has not been well characterized, and it is unknown if the phenotype is distinct from the more common sporadic congenital or acquired forms of CH. We studied nine ADCH families whose children displayed typical CH blood patterns. Pedigrees confirmed dominant inheritance without evidence of heterogeneity or decreased penetrance; three pedigrees suggested new mutations. Families were Caucasian with exception of one with a Cherokee Native American founder. A wide spectrum of symptom severity, ranging from asymptomatic to life-threatening illness, was observed within families. The phenotype changed with age. Children displayed typical neutrophil cycles with symptoms of mucosal ulceration, lymphadenopathy, and infections. Adults often had fewer and milder symptoms, sometimes accompanied by mild chronic neutropenia without distinct cycles. While CH is commonly described as {open_quotes}benign{close_quotes}, four children in three of the nine families died of Clostridium or E. coli colitis, documenting the need for urgent evaluation of abdominal pain. Misdiagnosis with other neutropenias was common but can be avoided by serial blood counts in index cases. Genetic counseling requires specific histories and complete blood counts in relatives at risk to assess status regardless of symptoms, especially to determine individuals with new mutations. We propose diagnostic criteria for ADCH in affected children and adults. Recombinant human granulocyte colony-stimulating factor treatment resulted in dramatic improvement of neutropenia and morbidity. The differential diagnosis from other forms of familial neutropenia is reviewed. 45 refs., 4 figs., 1 tab.

  6. Embryonic hematopoiesis in vertebrate somites gives rise to definitive hematopoietic stem cells.

    PubMed

    Qiu, Juhui; Fan, Xiaoying; Wang, Yixia; Jin, Hongbin; Song, Yixiao; Han, Yang; Huang, Shenghong; Meng, Yaping; Tang, Fuchou; Meng, Anming

    2016-08-01

    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

  7. Hypothalamic proline rich polypeptide regulates hematopoiesis.

    PubMed

    Bezirganyan, Kristina B; Davtyan, Tigran K; Galoyan, Armen A

    2010-06-01

    The AGAPEPAEPAQPGVY proline-rich polypeptide (PRP-1) was isolated from neurosecretory granules of the bovine neurohypophysis; it is produced by N. supraopticus and N. paraventricularis. It has been shown that PRP-1 has many potentially beneficial biological effects including immunoregulatory, hematopoietic, antimicrobial and anti-neurodegenerative properties. Here we demonstrated that PRP-1 administration influence on redistribution of monocytes, granulocytes and lymphocytes between bone marrow (BM) and peripheral blood and promotes the influx of granulocytes and monocytes/macrophages from BM into peripheral blood and accumulation of immature granulocyte and monocyte in BM and delayed the maturation of T cells in BM. PRP-1 increased colony-forming cell proliferation in rat cells in vivo. In PRP-treated rat BM, the CFU number at day 4, 7 and 14 was considerably increased in comparison with untreated rats BM and no difference was found at day 21 and day 28. We found that PRP-1 enhances erythroid and myeloid colonies formation in human CD34(+) progenitor cell culture in the presence of different growth factors and down-regulates T cells colony formation and specific surface markers expression during induction of human CD34(+) progenitor cells differentiation into T lymphocytes lineage. We suggested that the hypothalamic PRP-1 possibly represents an endogenous peptide whose primary functions are to regulate neuronal survival and differentiation and hematopoiesis within neurosecretory hypothalamus-bone marrow humoral axis. PMID:20020325

  8. Clonal hematopoiesis in acquired aplastic anemia.

    PubMed

    Ogawa, Seishi

    2016-07-21

    Clonal hematopoiesis (CH) in aplastic anemia (AA) has been closely linked to the evolution of late clonal disorders, including paroxysmal nocturnal hemoglobinuria and myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML), which are common complications after successful immunosuppressive therapy (IST). With the advent of high-throughput sequencing of recent years, the molecular aspect of CH in AA has been clarified by comprehensive detection of somatic mutations that drive clonal evolution. Genetic abnormalities are found in ∼50% of patients with AA and, except for PIGA mutations and copy-neutral loss-of-heterozygosity, or uniparental disomy (UPD) in 6p (6pUPD), are most frequently represented by mutations involving genes commonly mutated in myeloid malignancies, including DNMT3A, ASXL1, and BCOR/BCORL1 Mutations exhibit distinct chronological profiles and clinical impacts. BCOR/BCORL1 and PIGA mutations tend to disappear or show stable clone size and predict a better response to IST and a significantly better clinical outcome compared with mutations in DNMT3A, ASXL1, and other genes, which are likely to increase their clone size, are associated with a faster progression to MDS/AML, and predict an unfavorable survival. High frequency of 6pUPD and overrepresentation of PIGA and BCOR/BCORL1 mutations are unique to AA, suggesting the role of autoimmunity in clonal selection. By contrast, DNMT3A and ASXL1 mutations, also commonly seen in CH in the general population, indicate a close link to CH in the aged bone marrow, in terms of the mechanism for selection. Detection and close monitoring of somatic mutations/evolution may help with prediction and diagnosis of clonal evolution of MDS/AML and better management of patients with AA. PMID:27121470

  9. The evolutionary origins of chordate hematopoiesis and vertebrate endothelia.

    PubMed

    Pascual-Anaya, Juan; Albuixech-Crespo, Beatriz; Somorjai, Ildikó Maureen Lara; Carmona, Rita; Oisi, Yasuhiro; Alvarez, Susana; Kuratani, Shigeru; Muñoz-Chápuli, Ramón; Garcia-Fernàndez, Jordi

    2013-03-15

    The vertebrate circulatory system is the most complex vascular system among those of metazoans, with key innovations including a multi-chambered heart and highly specialized blood cells. Invertebrate vessels, on the other hand, consist of hemal spaces between the basal laminae of epithelia. How the evolutionary transition from an invertebrate-type system to the complex vertebrate one occurred is, however, poorly understood. We investigate here the development of the cardiovascular system of the cephalochordate amphioxus Branchiostoma lanceolatum in order to gain insight into the origin of the vertebrate cardiovascular system. The cardiac markers Hand, Csx (Nkx2-5) and Tbx4/5 reveal a broad cardiac-like domain in amphioxus; such a decentralized organization during development parallels that seen in the adult anatomy. Our data therefore support the hypothesis that amphioxus never possessed a proper heart, even transiently during development. We also define a putative hematopoietic domain, supported by the expression of the hematopoietic markers Scl and Pdvegfr. We show that this area is closed to the dorsal aorta anlages, partially linked to excretory tissues, and that its development is regulated by retinoic acid, thus recalling the aorta-gonads-mesonephros (AGM) area of vertebrates. This region probably produces Pdvegfr+ hemal cells, with an important role in amphioxus vessel formation, since treatments with an inhibitor of PDGFR/VEGFR lead to a decrease of Laminin in the basal laminae of developing vessels. Our results point to a chordate origin of hematopoiesis in an AGM-like area from where hemal Pdvegfr+ cells are produced. These Pdvegfr+ cells probably resemble the ancestral chordate blood cells from which the vertebrate endothelium later originated. PMID:23201012

  10. Osteogenesis with hematopoiesis simulating infection in a hydroxyapatite orbital implant.

    PubMed

    Jordan, David R; Belliveau, Michel J; Brownstein, Seymour; Padmore, Ruth F

    2009-01-01

    A 28-year-old woman underwent secondary orbital implant surgery with placement of a hydroxyapatite implant. Over the next 7 years she underwent 3 drilling procedures. She began having copious discharge 1 year after the last drilling procedure. She was seen on numerous occasions with socket discharge, unresponsive to a variety of topical and oral antibiotics. Clinically, with the conjunctiva diffusely inflamed, the implant tender to touch, and the presence of a pyogenic granuloma, implant infection was suspected and the implant subsequently removed. Histopathologic assessment revealed widespread lamellar bone formation, including focal areas of marrow with active extramedullary hematopoiesis. There was no evidence of an inflammatory process or infection. Postoperatively the patient's symptoms and signs resolved. Extramedullary hematopoiesis within hydroxyapatite implants is rare. Porous orbital implant infection is also rare. Osteogenesis with extramedullary hematopoiesis simulating implant infection has not previously been reported. PMID:19273939

  11. Correlating Histone Modification Patterns with Gene Expression Data During Hematopoiesis

    PubMed Central

    Hu, Gangqing; Zhao, Keji

    2014-01-01

    Hematopoietic stem cells (HSC) in mammals are an ideal system to study differentiation. While transcription factors (TFs) control the differentiation of HSCs to distinctive terminal blood cells, accumulating evidence suggests that chromatin structure and modifications constitute another critical layer of gene regulation. Recent genome-wide studies based on next-generation sequencing reveal that histone modifications are linked to gene expression and contribute to hematopoiesis. Here, we briefl y review the bioinformatics aspects for ChIP-Seq and RNA-Seq data analysis with applications to the epigenetic studies of hematopoiesis and provide a practical guide to several basic data analysis methods. PMID:24743998

  12. Lysine-specific histone demethylases in normal and malignant hematopoiesis.

    PubMed

    Andricovich, Jaclyn; Kai, Yan; Tzatsos, Alexandros

    2016-09-01

    The epigenetic control of gene expression is central to the development of the hematopoietic system and the execution of lineage-specific transcriptional programs. During the last 10 years, mounting evidence has implicated the family of lysine-specific histone demethylases as critical regulators of normal hematopoiesis, whereas their deregulation is found in a broad spectrum of hematopoietic malignancies. Here, we review recent findings on the role of these enzymes in normal and malignant hematopoiesis and highlight how aberrant epigenetic regulation facilitates hematopoietic cell transformation through subversion of cell fate and lineage commitment programs. PMID:27208808

  13. Murine mesenchymal stem cells transplanted to the central nervous system of neonatal versus adult mice exhibit distinct engraftment kinetics and express receptors that guide neuronal cell migration.

    PubMed

    Phinney, Donald G; Baddoo, Melody; Dutreil, Maria; Gaupp, Dina; Lai, Wen Tzu; Isakova, Iryna A

    2006-06-01

    Mesenchymal stem cells (MSCs) have demonstrated efficacy as cellular vectors for treating a variety of nervous system disorders. Nevertheless, few studies have quantified MSC engraftment levels or explored the mechanisms that promote their survival and migration in nervous tissue. In this study, we compared the engraftment kinetics and anatomical distribution of murine, male MSCs injected intracranially into neonatal versus adult female mice using a real-time PCR assay that targets the mouse SRY gene. These analyses revealed that MSCs exhibited low but equivalent engraftment levels in the central nervous system (CNS) of neonatal and adult transplant recipients at 12 days post-injection. However, MSC engraftment levels were significantly greater at 60 and 150 days post-transplantation in neonates as compared to adults. Despite these differences, engrafted MSCs were widely distributed along the neuraxis of the CNS in both transplant groups. Collectively, these data indicate that proliferation, but not engraftment and migration, of MSCs in brain are regulated by the host microenvironment. Using a genomics approach, we also identified MSC subpopulations that express neural adhesion proteins and receptors that regulate neuronal cell migration in brain, including cadherin 2, neurexin 1, ninjurin 1, neogenin 1, neuropilin 2, and roundabout homolog 1 and 4. Functional studies indicate these proteins confer cell adhesion and migration of MSCs in response to the appropriate chemoattractant. On the basis of these findings, we conclude that the unique molecular composition of MSC subpopulations imparts to them an inherent capacity to engraft and migrate in brain. These subpopulations may represent more potent cellular vectors for treating CNS disorders. PMID:16846379

  14. Intrathoracic extramedullary hematopoiesis: appearance on /sup 99m/Tc sulfur colloid marrow scan

    SciTech Connect

    Bronn, L.J.; Paquelet, J.R.; Tetalman, M.R.

    1980-06-01

    Imaging of the bone marrow by radionuclide scanning was performed using colloids, which are phagocytized by the reticuloendothelial cells of the marrow, or radioiron, which is incorporated into reticulocytes. The use of the former radiopharmaceutical is based on the assumption, generally valid except in aplastic states or after irradiation, that the distribution of hematopoietic and reticuloendothelial tissue in the marrow is similar. Regardless of the method used, active adult marrow is normally distributed only in the axial skeleton and proximal humeri and femurs. Marrow imaging has been used in the evaluation of myeloproliferative disorders, leukemia, lymphoma, aplastic states, malignancy metastatic to marrow, and hemolytic anemia. We report a case of thalassemia major in which the diagnosis of intrathoracic extramedullary hematopoiesis was confirmed with the /sup 99m/Tc sulfur colloid bone marrow scan.

  15. Expansion of human and murine hematopoietic stem and progenitor cells ex vivo without genetic modification using MYC and Bcl-2 fusion proteins.

    PubMed

    Bird, Gregory A; Polsky, Avital; Estes, Patricia; Hanlon, Teri; Hamilton, Haley; Morton, John J; Gutman, Jonathan; Jimeno, Antonio; Turner, Brian C; Refaeli, Yosef

    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

  16. Leukemic blast cells and controversies in models of hematopoiesis.

    PubMed

    Gluzman, D F; Sklyarenko, L M; Zavelevich, M P; Koval, S V; Ivanovskaya, T S

    2015-03-01

    Classical and up-to-date models of hematopoietic lineage determination are briefly reviewed with the focus on myeloid-based models challenging the existence of the common progenitor for T cells, B cells and NK cells. The analysis of immunophenotype of leukemic blast cells seems to be a promising approach for interpreting some controversies in the schemes of normal hematopoiesis. The literature data as well as our own findings in the patients with various types of acute leukemias are in favor of the concept postulating that common myeloid-lymphoid progenitors giving rise to T and B cell branches retain the myeloid potential. The similarity of some immunophenotypic features of blast cells in pro-B acute lymphoblastic leukemia and acute monoblastic leukemia is consistent with monocyte origin postulated in the studies of normal hematopoiesis. Study of acute leukemias may be the challenging area of research allowing for new insight into the origin of hematopoietic cell lineages. PMID:25804223

  17. The Role of Histone Acetyltransferases in Normal and Malignant Hematopoiesis

    PubMed Central

    Sun, Xiao-Jian; Man, Na; Tan, Yurong; Nimer, Stephen D.; Wang, Lan

    2015-01-01

    Histone, and non-histone, protein acetylation plays an important role in a variety of cellular events, including the normal and abnormal development of blood cells, by changing the epigenetic status of chromatin and regulating non-histone protein function. Histone acetyltransferases (HATs), which are the enzymes responsible for histone and non-histone protein acetylation, contain p300/CBP, MYST, and GNAT family members. HATs are not only protein modifiers and epigenetic factors but also critical regulators of cell development and carcinogenesis. Here, we will review the function of HATs such as p300/CBP, Tip60, MOZ/MORF, and GCN5/PCAF in normal hematopoiesis and the pathogenesis of hematological malignancies. The inhibitors that have been developed to target HATs will also be reviewed here. Understanding the roles of HATs in normal/malignant hematopoiesis will provide the potential therapeutic targets for the hematological malignancies. PMID:26075180

  18. The Role of Histone Acetyltransferases in Normal and Malignant Hematopoiesis.

    PubMed

    Sun, Xiao-Jian; Man, Na; Tan, Yurong; Nimer, Stephen D; Wang, Lan

    2015-01-01

    Histone, and non-histone, protein acetylation plays an important role in a variety of cellular events, including the normal and abnormal development of blood cells, by changing the epigenetic status of chromatin and regulating non-histone protein function. Histone acetyltransferases (HATs), which are the enzymes responsible for histone and non-histone protein acetylation, contain p300/CBP, MYST, and GNAT family members. HATs are not only protein modifiers and epigenetic factors but also critical regulators of cell development and carcinogenesis. Here, we will review the function of HATs such as p300/CBP, Tip60, MOZ/MORF, and GCN5/PCAF in normal hematopoiesis and the pathogenesis of hematological malignancies. The inhibitors that have been developed to target HATs will also be reviewed here. Understanding the roles of HATs in normal/malignant hematopoiesis will provide the potential therapeutic targets for the hematological malignancies. PMID:26075180

  19. Extramedullary hematopoiesis manifesting as a symptomatic pleural effusion.

    PubMed

    Bartlett, R P; Greipp, P R; Tefferi, A; Cupps, R E; Mullan, B P; Trastek, V F

    1995-12-01

    The occurrence of extramedullary hematopoiesis in the pleura is rare and is usually asymptomatic. It is generally diagnosed on postmortem examination. Herein we describe a 61-year-old woman with agnogenic myeloid metaplasia who sought medical assessment because of progressive dyspnea. Thoracentesis yielded sanguineous fluid with 10% myeloblasts. A 99mTc bone marrow scan demonstrated increased tracer activity throughout both lungs, an outcome consistent with extramedullary hematopoiesis. Fine-needle aspiration and video-assisted thoracoscopy were considered but deferred because of the potential risk of profuse bleeding. Treatment with low-dose external beam irradiation to the left posterior pleura was successful. To date, no hemothorax has recurred. PMID:7490917

  20. Fell Pony Syndrome: Characterization of Developmental Hematopoiesis Failure and Associated Gene Expression Profiles

    PubMed Central

    Tallmadge, Rebecca L.; Stokol, Tracy; Gould-Earley, Mary Jean; Earley, Ed; Secor, Erica J.; Matychak, Mary Beth

    2012-01-01

    Fell Pony syndrome (FPS) is a fatal immunodeficiency that occurs in foals of the Fell Pony breed. Affected foals present with severe anemia, B cell lymphopenia, and opportunistic infections. Our objective was to conduct a prospective study of potential FPS-affected Fell Pony foals to establish clinical, immunological, and molecular parameters at birth and in the first few weeks of life. Complete blood counts, peripheral blood lymphocyte phenotyping, and serum immunoglobulin concentrations were determined for 3 FPS-affected foals, 49 unaffected foals, and 6 adult horses. In addition, cytology of bone marrow aspirates was performed sequentially in a subset of foals. At birth, the FPS-affected foals were not noticeably ill and had hematocrit and circulating B cell counts comparable to those of unaffected foals; however, over 6 weeks, values for both parameters steadily declined. A bone marrow aspirate from a 3-week-old FPS-affected foal revealed erythroid hyperplasia and concurrent erythroid and myeloid dysplasia, which progressed to a severe erythroid hypoplasia at 5 weeks of life. Immunohistochemical staining confirmed the paucity of B cells in primary and secondary lymphoid tissues. The mRNA expression of genes involved in B cell development, signaling, and maturation was investigated using qualitative and quantitative reverse transcriptase PCR (RT-PCR). Several genes, including CREB1, EP300, MYB, PAX5, and SPI1/PU.1, were sequenced from FPS-affected and unaffected foals. Our study presents evidence of fetal erythrocyte and B cell hematopoiesis with rapid postnatal development of anemia and B lymphopenia in FPS-affected foals. The transition between fetal/neonatal and adult-like hematopoiesis may be an important aspect of the pathogenesis of FPS. PMID:22593239

  1. Angiopoietin-1 facilitates recovery of hematopoiesis in radiated mice

    PubMed Central

    Sun, Lan; Zhang, Huaibao; Bi, Laixi; Shi, Yi-Fen; Xing, Chongyun; Tang, Liyuan; Jiang, Songfu; Yu, Kang

    2016-01-01

    Angiopoietin-1 (Ang-1) plays a critical role in the regulation of endothelial cell survival and vascular maturation and stability. However, its role in hematopoiesis is not clear. Here, we determined effect of Ang-1 on the recovery of hematopoiesis in radiated mice. By injecting an Ang-1 plasmid, we found that Ang-1 was preferentially expressed in bone marrow (BM) of femur from radiated mice. This injection resulted in elevated blood counts and serum VEGF level. The blockade in S phase of cell cycle in mouse BM stromal cells following radiation was attenuated by injection of Ang-1 plasmid. In addition, injection of Ang-1 plasmid attenuated the radiation-mediated inhibition of Tie2 expression. Furthermore, through analyzing Notch1 expression, we found that injection of Ang-1 plasmid increased Notch mRNA expression in radiated mice. In conclusion, these findings suggest that Ang-1 facilitates the recovery of hematopoiesis in radiated mice with the involvement of Notch signaling pathway. PMID:27347310

  2. Angiopoietin-1 facilitates recovery of hematopoiesis in radiated mice.

    PubMed

    Sun, Lan; Zhang, Huaibao; Bi, Laixi; Shi, Yi-Fen; Xing, Chongyun; Tang, Liyuan; Jiang, Songfu; Yu, Kang

    2016-01-01

    Angiopoietin-1 (Ang-1) plays a critical role in the regulation of endothelial cell survival and vascular maturation and stability. However, its role in hematopoiesis is not clear. Here, we determined effect of Ang-1 on the recovery of hematopoiesis in radiated mice. By injecting an Ang-1 plasmid, we found that Ang-1 was preferentially expressed in bone marrow (BM) of femur from radiated mice. This injection resulted in elevated blood counts and serum VEGF level. The blockade in S phase of cell cycle in mouse BM stromal cells following radiation was attenuated by injection of Ang-1 plasmid. In addition, injection of Ang-1 plasmid attenuated the radiation-mediated inhibition of Tie2 expression. Furthermore, through analyzing Notch1 expression, we found that injection of Ang-1 plasmid increased Notch mRNA expression in radiated mice. In conclusion, these findings suggest that Ang-1 facilitates the recovery of hematopoiesis in radiated mice with the involvement of Notch signaling pathway. PMID:27347310

  3. 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

  4. GATA Factor-G-Protein-Coupled Receptor Circuit Suppresses Hematopoiesis.

    PubMed

    Gao, Xin; Wu, Tongyu; Johnson, Kirby D; Lahvic, Jamie L; Ranheim, Erik A; Zon, Leonard I; Bresnick, Emery H

    2016-03-01

    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

  5. Integration of Shh and Wnt Signaling Pathways Regulating Hematopoiesis.

    PubMed

    Zhou, Zhigang; Wan, Liping; Wang, Chun; Zhou, Kun

    2015-12-01

    To investigate the spatial and temporal programmed expression of Shh and Wnt members during key stages of definitive hematopoiesis and the possible mechanism of Shh and Wnt signaling pathways regulating the proliferation of hematopoietic progenitor cells (HPCs). Spatial and temporal programmed gene expression of Shh and Wnt signaling during hematopoiesis corresponded with c-kit(+)lin(-) HPCs proliferation. C-kit(+)Lin(-) populations derived from aorta-gonad-mesonephros (AGM) of Balb/c mice at E10.5 with increased expression of Shh and Wnt3a demonstrated a greater potential for proliferation. Additionally, supplementation with soluble Shh N-terminal peptide promoted the proliferation of c-kit(+)Lin(-) populations by activating the Wnt signaling pathway, an effect which was inhibited by blocking Shh signaling. A specific inhibitor of wnt signaling was capable of inhibiting Shh-induced proliferation in a similar manner to shh inhibitor. Our results provide valuable information on Shh and Wnt signaling involved in hematopoiesis and highlight the importance of interaction of Shh and Wnt signaling in regulating HPCs proliferation. PMID:26378473

  6. Hematopoiesis on nylon mesh templates. I. Long-term culture of rat bone marrow cells.

    PubMed

    Naughton, B A; Preti, R A; Naughton, G K

    1987-01-01

    Rodent hematopoietic cells have been perpetuated in long-term bone marrow culture (LTBMC), provided that they were plated onto a pre-established layer of bone marrow stromal cells (fibroblasts, reticular cells, adipocytes, macrophages, etc.). This monolayer-type system supports the self-renewal of murine pluripotent stem cells and produces substantial numbers of progenitors and mature cells of the myeloid lineage. In an effort to increase the growth potential of cells in LTBMC, an adherent matrix of stromal cells was established on a pretreated nylon screen template. Subsequent seeding of hematopoietic cells onto this matrix occurred both on the surface of the adherent layer and in the interstices formed by the developing stromal cells. A three dimensional growth pattern of hematopoietic colonies and clusters was observed. Mature cells and late stage precursors of the myeloid and erythroid series were observed in the non-adherent layer for the duration of the experiment (39 weeks). Cells similar in appearance to small lymphocytes were also seen in both the non-adherent and adherent layers. Cells associated with the adherent layer of this LTBMC system displayed the ability to reconstitute hematopoiesis in the irradiated host. It is suggested that because of its three-dimensional nature the nylon mesh LTBMC system possesses a greater hematologic potential per unit area than monolayer-type LTBMC. PMID:3480934

  7. Histone demethylase KDM2B regulates lineage commitment in normal and malignant hematopoiesis

    PubMed Central

    Andricovich, Jaclyn; Kai, Yan; Peng, Weiqun; Foudi, Adlen; Tzatsos, Alexandros

    2016-01-01

    The development of the hematopoietic system is a dynamic process that is controlled by the interplay between transcriptional and epigenetic networks to determine cellular identity. These networks are critical for lineage specification and are frequently dysregulated in leukemias. Here, we identified histone demethylase KDM2B as a critical regulator of definitive hematopoiesis and lineage commitment of murine hematopoietic stem and progenitor cells (HSPCs). RNA sequencing of Kdm2b-null HSPCs and genome-wide ChIP studies in human leukemias revealed that KDM2B cooperates with polycomb and trithorax complexes to regulate differentiation, lineage choice, cytokine signaling, and cell cycle. Furthermore, we demonstrated that KDM2B exhibits a dichotomous role in hematopoietic malignancies. Specifically, we determined that KDM2B maintains lymphoid leukemias, but restrains RAS-driven myeloid transformation. Our study reveals that KDM2B is an important mediator of hematopoietic cell development and has opposing roles in tumor progression that are dependent on cellular context. PMID:26808549

  8. Histone demethylase KDM2B regulates lineage commitment in normal and malignant hematopoiesis.

    PubMed

    Andricovich, Jaclyn; Kai, Yan; Peng, Weiqun; Foudi, Adlen; Tzatsos, Alexandros

    2016-03-01

    The development of the hematopoietic system is a dynamic process that is controlled by the interplay between transcriptional and epigenetic networks to determine cellular identity. These networks are critical for lineage specification and are frequently dysregulated in leukemias. Here, we identified histone demethylase KDM2B as a critical regulator of definitive hematopoiesis and lineage commitment of murine hematopoietic stem and progenitor cells (HSPCs). RNA sequencing of Kdm2b-null HSPCs and genome-wide ChIP studies in human leukemias revealed that KDM2B cooperates with polycomb and trithorax complexes to regulate differentiation, lineage choice, cytokine signaling, and cell cycle. Furthermore, we demonstrated that KDM2B exhibits a dichotomous role in hematopoietic malignancies. Specifically, we determined that KDM2B maintains lymphoid leukemias, but restrains RAS-driven myeloid transformation. Our study reveals that KDM2B is an important mediator of hematopoietic cell development and has opposing roles in tumor progression that are dependent on cellular context. PMID:26808549

  9. Hematopoiesis during development, aging, and disease.

    PubMed

    Jung, Johannes; Buisman, Sonja; de Haan, Gerald

    2016-08-01

    Hematopoietic stem cells were once considered identical. However, in the mid-1990s, it became apparent that stem cells from a person's early developmental phases are superior to those from adults, and aged stem cells are defective compared with young stem cells. It has since become clear that polycomb group proteins are important regulators of stem cell functioning. Polycomb group proteins are chromatin-associated proteins involved in writing or reading epigenetic histone modifications. Polycomb group proteins are involved in normal blood cell formation, in cancer, and possibly in aging. In this review, we describe how the different phases of hematopoietic stem cells-birth, maintenance, functional decline, derailment, and death-are continuous processes that may be controlled by polycomb group proteins. PMID:27235755

  10. Spleen hypoplasia leads to abnormal stress hematopoiesis in mice with loss of Pbx homeoproteins in splenic mesenchyme.

    PubMed

    Zewdu, Rediet; Risolino, Maurizio; Barbulescu, Alexandru; Ramalingam, Pradeep; Butler, Jason M; Selleri, Licia

    2016-07-01

    The spleen plays critical roles in immunity and also provides a permissive microenvironment for hematopoiesis. Previous studies have reported that the TALE-class homeodomain transcription factor Pbx1 is essential in hematopoietic stem and progenitor cells (HSPCs) for stem cell maintenance and progenitor expansion. However, the role of Pbx1 in the hematopoietic niche has not been investigated. Here we explored the effects that genetic perturbation of the splenic mesenchymal niche has on hematopoiesis upon loss of members of the Pbx family of homeoproteins. Splenic mesenchyme-specific inactivation of Pbx1 (SKO) on a Pbx2- or Pbx3-deficient genetic background (DKO) resulted in abnormal development of the spleen, which is dysmorphic and severely hypoplastic. This phenotype, in turn, affected the number of HSPCs in the fetal and adult spleen at steady state, as well as markedly impairing the kinetics of hematopoietic regeneration in adult mice after sub-lethal and lethal myelosuppressive irradiation. Spleens of mice with compound Pyx deficiency 8 days following sublethal irradiation displayed significant downregulation of multiple cytokine-encoding genes, including KitL/SCF, Cxcl12/SDF-1, IL-3, IL-4, GM-CSF/Csf2 IL-10, and Igf-1, compared with controls. KitL/SCF and Cxcl12/SDF-1 were recently shown to play key roles in the splenic niche in response to various haematopoietic stresses such as myeloablation, blood loss, or pregnancy. Our results demonstrate that, in addition to their intrinsic roles in HSPCs, non-cell autonomous functions of Pbx factors within the splenic niche contribute to the regulation of hematopoiesis, at least in part via the control of KitL/SCF and Cxcl12/SDF-1. Furthermore, our study establishes that abnormal spleen development and hypoplasia have deleterious effects on the efficiency of hematopoietic recovery after bone marrow injury. PMID:27075259

  11. Megaloblastic hematopoiesis in a 20 year old pregnant female

    PubMed Central

    Trivette, Evan T.; Hoedebecke, Kyle; Berry-Cabán, Cristóbal S.; Jacobs, Brandy R.

    2013-01-01

    Summary Background: Nitrous oxide can cause disordered blood cell proliferation and lead to pancytopenia and altered immune function. Case Report: A young pregnant female patient presented after binge nitrous oxide abuse with altered mental status and abnormal vital signs. From her initial assessment she was noted to have pancytopenia and was found to have megaloblastic, hyper-cellular changes in a subsequent bone marrow biopsy. This presentation was determined to be secondary to toxic effects after heavy use of nitrous oxide. Conclusions: Nitrous oxide exposure, including use as an inhalant, over 12 hours can lead to bone marrow abnormalities such as megaloblastic hematopoiesis. PMID:23569553

  12. MicroRNA-155 and Its Role in Malignant Hematopoiesis

    PubMed Central

    Ranganath, Prajnya

    2015-01-01

    MicroRNA-155 (miR-155) is a multifunctional molecule involved in both normal and malignant hematopoiesis. It has been found to be involved in the pathogenesis of many different hematological malignancies with either an oncogenic or a tumor-repressor effect, depending on the nature of the cell and the type of malignancy. In particular, it has been strongly implicated in the causation of diffuse large B-cell lymphomas. This review focuses on the molecular interactions of miR-155, its oncogenic mechanisms, and its potential as an effective therapeutic target for the associated malignancies. PMID:26523117

  13. Brain Derived Neurotrophic Factor Contributes to the Cardiogenic Potential of Adult Resident Progenitor Cells in Failing Murine Heart

    PubMed Central

    Samal, Rasmita; Ameling, Sabine; Dhople, Vishnu; Sappa, Praveen Kumar; Wenzel, Kristin; Völker, Uwe; Felix, Stephan B.; Hammer, Elke; Könemann, Stephanie

    2015-01-01

    Aims Resident cardiac progenitor cells show homing properties when injected into the injured but not to the healthy myocardium. The molecular background behind this difference in behavior needs to be studied to elucidate how adult progenitor cells can restore cardiac function of the damaged myocardium. Since the brain derived neurotrophic factor (BDNF) moderates cardioprotection in injured hearts, we focused on delineating its regulatory role in the damaged myocardium. Methods and Results Comparative gene expression profiling of freshly isolated undifferentiated Sca-1 progenitor cells derived either from heart failure transgenic αMHC-CyclinT1/Gαq overexpressing mice or wildtype littermates revealed transcriptional variations. Bdnf expression was up regulated 5-fold during heart failure which was verified by qRT-PCR and confirmed at protein level. The migratory capacity of Sca-1 cells from transgenic hearts was improved by 15% in the presence of 25ng/ml BDNF. Furthermore, BDNF-mediated effects on Sca-1 cells were studied via pulsed Stable Isotope Labeling of Amino acids in Cell Culture (pSILAC) proteomics approach. After BDNF treatment significant differences between newly synthesized proteins in Sca-1 cells from control and transgenic hearts were observed for CDK1, SRRT, HDGF, and MAP2K3 which are known to regulate cell cycle, survival and differentiation. Moreover BDNF repressed the proliferation of Sca-1 cells from transgenic hearts. Conclusion Comparative profiling of resident Sca-1 cells revealed elevated BDNF levels in the failing heart. Exogenous BDNF (i) stimulated migration, which might improve the homing ability of Sca-1 cells derived from the failing heart and (ii) repressed the cell cycle progression suggesting its potency to ameliorate heart failure. PMID:25799225

  14. Lysophosphatidic acid acts as a nutrient-derived developmental cue to regulate early hematopoiesis

    PubMed Central

    Li, Haisen; Yue, Rui; Wei, Bin; Gao, Ge; Du, Jiulin; Pei, Gang

    2014-01-01

    Primitive hematopoiesis occurs in the yolk sac blood islands during vertebrate embryogenesis, where abundant phosphatidylcholines (PC) are available as important nutrients for the developing embryo. However, whether these phospholipids also generate developmental cues to promote hematopoiesis is largely unknown. Here, we show that lysophosphatidic acid (LPA), a signaling molecule derived from PC, regulated hemangioblast formation and primitive hematopoiesis. Pharmacological and genetic blockage of LPA receptor 1 (LPAR1) or autotoxin (ATX), a secretory lysophospholipase that catalyzes LPA production, inhibited hematopoietic differentiation of mouse embryonic stem cells and impaired the formation of hemangioblasts. Mechanistic experiments revealed that the regulatory effect of ATX-LPA signaling was mediated by PI3K/Akt-Smad pathway. Furthermore, during in vivo embryogenesis in zebrafish, LPA functioned as a developmental cue for hemangioblast formation and primitive hematopoiesis. Taken together, we identified LPA as an important nutrient-derived developmental cue for primitive hematopoiesis as well as a novel mechanism of hemangioblast regulation. PMID:24829209

  15. Murine Typhus

    PubMed Central

    Dzul-Rosado, Karla R; Zavala Velázquez, Jorge Ernesto; Zavala-Castro, Jorge

    2012-01-01

    Rickettsia typhi: is an intracellular bacteria who causes murine typhus. His importance is reflected in the high frequency founding specific antibodies against Rickettsia typhi in several worldwide seroepidemiological studies, the seroprevalence ranging between 3-36%. Natural reservoirs of R. typhi are rats (some species belonging the Rattus Genus) and fleas (Xenopsylla cheopis) are his vector. This infection is associated with overcrowding, pollution and poor hygiene. Typically presents fever, headache, rash on trunk and extremities, in some cases may occur organ-specific complications, affecting liver, kidney, lung or brain. Initially the disease is very similar to other diseases, is very common to confuse the murine typhus with Dengue fever, therefore, ignorance of the disease is a factor related to complications or non-specific treatments for the resolution of this infection. This paper presents the most relevant information to consider about the rickettsiosis caused by Rickettsia typhi. PMID:24893060

  16. Eicosanoid Regulation of Hematopoiesis and Hematopoietic Stem and Progenitor Trafficking

    PubMed Central

    Hoggatt, Jonathan; Pelus, Louis M.

    2011-01-01

    Hematopoietic stem cell (HSC) transplantation is a potentially curative treatment for numerous hematologic malignancies. The transplant procedure as performed today takes advantage of HSC trafficking; either egress of HSC from the bone marrow to the peripheral blood, i.e. mobilization, for acquisition of the hematopoietic graft, and/or trafficking of HSC from the peripheral blood to bone marrow niches in the recipient patient, i.e. HSC homing. Numerous studies, many of which are reviewed herein, have defined hematopoietic regulatory mechanisms mediated by the 20-carbon lipid family of eicosanoids, and recent evidence strongly supports a role for eicosanoids in regulation of hematopoietic trafficking, adding a new role whereby eicosanoids regulate hematopoiesis. Short-term exposure of HSC to the eicosanoid prostaglandin E2 (PGE2) increases CXCR4 receptor expression, migration and in vivo homing of HSC. In contrast, cannabinoids reduce hematopoietic progenitor cell (HPC) CXCR4 expression and induce HPC mobilization when administered in vivo. Leukotrienes have been shown to alter CD34+ cell adhesion, migration, and regulate HSC proliferation, suggesting that eicosanoids have both opposing and complimentary roles in the regulation of hematopoiesis. Since numerous FDA approved compounds regulate eicosanoid signaling or biosynthesis, the utility of eicosanoid based therapeutic strategies to improve hematopoietic transplantation can be rapidly evaluated. PMID:20882043

  17. Thalassemia, extramedullary hematopoiesis, and spinal cord compression: A case report

    PubMed Central

    Bukhari, Syed Sarmad; Junaid, Muhammad; Rashid, Mamoon Ur

    2016-01-01

    Background: Extramedullary hematopoiesis (EMH) refers to hematopoiesis outside of the medulla of the bone. Chronic anemia states such as thalassemia can cause hematopoietic tissue to expand in certain locations. We report a case of spinal cord compression due to recurrent spinal epidural EMH, which was treated with a combination of surgery and radiotherapy. Pakistan has one of the highest incidence and prevalence of thalassemia in the world. We describe published literature on diagnosis and management of such cases. Case Description: An 18-year-old male presented with bilateral lower limb paresis. He was a known case of homozygous beta thalassemia major. He had undergone surgery for spinal cord compression due to EMH 4 months prior to presentation. Symptom resolution was followed by deterioration 5 days later. He was operated again at our hospital with complete resection of the mass. He underwent local radiotherapy to prevent recurrence. At 2 years follow-up, he showed complete resolution of symptoms. Follow-up imaging demonstrated no residual mass. Conclusion: The possibility of EMH should be considered in every patient with ineffective erythropoiesis as a cause of spinal cord compression. Treatment of such cases is usually done with blood transfusions, which can reduce the hematopoietic drive for EMH. Other options include surgery, hydroxyurea, radiotherapy, or a combination of these on a case to case basis. PMID:27069747

  18. AU-rich RNA binding proteins in hematopoiesis and leukemogenesis.

    PubMed

    Baou, Maria; Norton, John D; Murphy, John J

    2011-11-24

    Posttranscriptional mechanisms are now widely acknowledged to play a central role in orchestrating gene-regulatory networks in hematopoietic cell growth, differentiation, and tumorigenesis. Although much attention has focused on microRNAs as regulators of mRNA stability/translation, recent data have highlighted the role of several diverse classes of AU-rich RNA-binding protein in the regulation of mRNA decay/stabilization. AU-rich elements are found in the 3'-untranslated region of many mRNAs that encode regulators of cell growth and survival, such as cytokines and onco/tumor-suppressor proteins. These are targeted by a burgeoning number of different RNA-binding proteins. Three distinct types of AU-rich RNA binding protein (ARE poly-U-binding degradation factor-1/AUF1, Hu antigen/HuR/HuA/ELAVL1, and the tristetraprolin/ZFP36 family of proteins) are essential for normal hematopoiesis. Together with 2 further AU-rich RNA-binding proteins, nucleolin and KHSRP/KSRP, the functions of these proteins are intimately associated with pathways that are dysregulated in various hematopoietic malignancies. Significantly, all of these AU-rich RNA-binding proteins function via an interconnected network that is integrated with microRNA functions. Studies of these diverse types of RNA binding protein are providing novel insight into gene-regulatory mechanisms in hematopoiesis in addition to offering new opportunities for developing mechanism-based targeted therapeutics in leukemia and lymphoma. PMID:21917750

  19. Regulation of Primitive Hematopoiesis by Class I Histone Deacetylases

    PubMed Central

    Shah, Rishita R.; Koniski, Anne; Shinde, Mansi; Blythe, Shelby A.; Fass, Daniel M.; Haggarty, Stephen J.; Palis, James; Klein, Peter S.

    2013-01-01

    Background Histone deacetylases (HDACs) regulate multiple developmental processes and cellular functions. However, their roles in blood development have not been determined, and in Xenopus laevis, a specific function for HDACs has yet to be identified. Here, we employed the class I selective HDAC inhibitor, valproic acid (VPA), to show that HDAC activity is required for primitive hematopoiesis. Results VPA treatment during gastrulation resulted in a complete absence of red blood cells (RBCs) in Xenopus tadpoles, but did not affect development of other mesodermal tissues, including myeloid and endothelial lineages. These effects of VPA were mimicked by Trichostatin A (TSA), a well-established pan-HDAC inhibitor, but not by valpromide, which is structurally similar to VPA but does not inhibit HDACs. VPA also caused a marked, dose-dependent loss of primitive erythroid progenitors in mouse yolk sac explants at clinically relevant concentrations. In addition, VPA treatment inhibited erythropoietic development downstream of bmp4 and gata1 in Xenopus ectodermal explants. Conclusions These findings suggest an important role for class I HDACs in primitive hematopoiesis. Our work also demonstrates that specific developmental defects associated with exposure to VPA, a significant teratogen in humans, arise through inhibition of class I HDACs. PMID:23184530

  20. SRSF2 Is Essential for Hematopoiesis, and Its Myelodysplastic Syndrome-Related Mutations Dysregulate Alternative Pre-mRNA Splicing

    PubMed Central

    Komeno, Yukiko; Huang, Yi-Jou; Qiu, Jinsong; Lin, Leo; Xu, YiJun; Zhou, Yu; Chen, Liang; Monterroza, Dora D.; Li, Hairi; DeKelver, Russell C.; Yan, Ming

    2015-01-01

    Myelodysplastic syndromes (MDS) are a group of neoplasms characterized by ineffective myeloid hematopoiesis and various risks for leukemia. SRSF2, a member of the serine/arginine-rich (SR) family of splicing factors, is one of the mutation targets associated with poor survival in patients suffering from myelodysplastic syndromes. Here we report the biological function of SRSF2 in hematopoiesis by using conditional knockout mouse models. Ablation of SRSF2 in the hematopoietic lineage caused embryonic lethality, and Srsf2-deficient fetal liver cells showed significantly enhanced apoptosis and decreased levels of hematopoietic stem/progenitor cells. Induced ablation of SRSF2 in adult Mx1-Cre Srsf2flox/flox mice upon poly(I):poly(C) injection demonstrated a significant decrease in lineage− Sca+ c-Kit+ cells in bone marrow. To reveal the functional impact of myelodysplastic syndromes-associated mutations in SRSF2, we analyzed splicing responses on the MSD-L cell line and found that the missense mutation of proline 95 to histidine (P95H) and a P95-to-R102 in-frame 8-amino-acid deletion caused significant changes in alternative splicing. The affected genes were enriched in cancer development and apoptosis. These findings suggest that intact SRSF2 is essential for the functional integrity of the hematopoietic system and that its mutations likely contribute to development of myelodysplastic syndromes. PMID:26124281

  1. Maintenance of the functional integrity of mouse hematopoiesis by EED and promotion of leukemogenesis by EED haploinsufficiency

    PubMed Central

    Ikeda, Kenichiro; Ueda, Takeshi; Yamasaki, Norimasa; Nakata, Yuichiro; Sera, Yasuyuki; Nagamachi, Akiko; Miyama, Takahiko; Kobayashi, Hiroshi; Takubo, Keiyo; Kanai, Akinori; Oda, Hideaki; Wolff, Linda; Honda, Zen-ichiro; Ichinohe, Tatsuo; Matsubara, Akio; Suda, Toshio; Inaba, Toshiya; Honda, Hiroaki

    2016-01-01

    Polycomb repressive complex 2 (PRC2) participates in transcriptional repression through methylation of histone H3K27. The WD-repeat protein embryonic ectoderm development (EED) is a non-catalytic but an essential component of PRC2 and its mutations were identified in hematopoietic malignancies. To clarify the role(s) of EED in adult hematopoiesis and leukemogenesis, we generated Eed conditional knockout (EedΔ/Δ) mice. EedΔ/Δ mice died in a short period with rapid decrease of hematopoietic cells. Hematopoietic stem/progenitor cells (HSPCs) were markedly decreased with impaired bone marrow (BM) repopulation ability. Cell cycle analysis of HSPCs demonstrated increased S-phase fraction coupled with suppressed G0/G1 entry. Genes encoding cell adhesion molecules are significantly enriched in EedΔ/Δ HSPCs, and consistently, EedΔ/Δ HSPCs exhibited increased attachment to a major extracellular matrix component, fibronectin. Thus, EED deficiency increases proliferation on one side but promotes quiescence possibly by enhanced adhesion to the hematopoietic niche on the other, and these conflicting events would lead to abnormal differentiation and functional defect of EedΔ/Δ HSPCs. In addition, Eed haploinsufficiency induced hematopoietic dysplasia, and Eed heterozygous mice were susceptible to malignant transformation and developed leukemia in cooperation with Evi1 overexpression. Our results demonstrated differentiation stage-specific and dose-dependent roles of EED in normal hematopoiesis and leukemogenesis. PMID:27432459

  2. Maintenance of the functional integrity of mouse hematopoiesis by EED and promotion of leukemogenesis by EED haploinsufficiency.

    PubMed

    Ikeda, Kenichiro; Ueda, Takeshi; Yamasaki, Norimasa; Nakata, Yuichiro; Sera, Yasuyuki; Nagamachi, Akiko; Miyama, Takahiko; Kobayashi, Hiroshi; Takubo, Keiyo; Kanai, Akinori; Oda, Hideaki; Wolff, Linda; Honda, Zen-Ichiro; Ichinohe, Tatsuo; Matsubara, Akio; Suda, Toshio; Inaba, Toshiya; Honda, Hiroaki

    2016-01-01

    Polycomb repressive complex 2 (PRC2) participates in transcriptional repression through methylation of histone H3K27. The WD-repeat protein embryonic ectoderm development (EED) is a non-catalytic but an essential component of PRC2 and its mutations were identified in hematopoietic malignancies. To clarify the role(s) of EED in adult hematopoiesis and leukemogenesis, we generated Eed conditional knockout (Eed(Δ/Δ)) mice. Eed(Δ/Δ) mice died in a short period with rapid decrease of hematopoietic cells. Hematopoietic stem/progenitor cells (HSPCs) were markedly decreased with impaired bone marrow (BM) repopulation ability. Cell cycle analysis of HSPCs demonstrated increased S-phase fraction coupled with suppressed G0/G1 entry. Genes encoding cell adhesion molecules are significantly enriched in Eed(Δ/Δ) HSPCs, and consistently, Eed(Δ/Δ) HSPCs exhibited increased attachment to a major extracellular matrix component, fibronectin. Thus, EED deficiency increases proliferation on one side but promotes quiescence possibly by enhanced adhesion to the hematopoietic niche on the other, and these conflicting events would lead to abnormal differentiation and functional defect of Eed(Δ/Δ) HSPCs. In addition, Eed haploinsufficiency induced hematopoietic dysplasia, and Eed heterozygous mice were susceptible to malignant transformation and developed leukemia in cooperation with Evi1 overexpression. Our results demonstrated differentiation stage-specific and dose-dependent roles of EED in normal hematopoiesis and leukemogenesis. PMID:27432459

  3. The GIY-YIG Type Endonuclease Ankyrin Repeat and LEM Domain-Containing Protein 1 (ANKLE1) Is Dispensable for Mouse Hematopoiesis

    PubMed Central

    Braun, Juliane; Meixner, Arabella; Brachner, Andreas; Foisner, Roland

    2016-01-01

    Ankyrin repeat and LEM-domain containing protein 1 (ANKLE1) is a GIY-YIG endonuclease with unknown functions, mainly expressed in mouse hematopoietic tissues. To test its potential role in hematopoiesis we generated Ankle1-deficient mice. Ankle1Δ/Δ mice are viable without any detectable phenotype in hematopoiesis. Neither hematopoietic progenitor cells, myeloid and lymphoid progenitors, nor B and T cell development in bone marrow, spleen and thymus, are affected in Ankle1Δ/Δ-mice. Similarly embryonic stress erythropoiesis in liver and adult erythropoiesis in bone marrow and spleen appear normal. To test whether ANKLE1, like the only other known GIY-YIG endonuclease in mammals, SLX1, may contribute to Holliday junction resolution during DNA repair, Ankle1-deficient cells were exposed to various DNA-damage inducing agents. However, lack of Ankle1 did not affect cell viability and, unlike depletion of Slx1, Ankle1-deficiency did not increase sister chromatid exchange in Bloom helicase-depleted cells. Altogether, we show that lack of Ankle1 does neither affect mouse hematopoiesis nor DNA damage repair in mouse embryonic fibroblasts, indicating a redundant or non-essential function of ANKLE1 in mouse. PMID:27010503

  4. The human microbiome in hematopoiesis and hematologic disorders

    PubMed Central

    Manzo, Veronica E.

    2015-01-01

    Humans are now understood to be in complex symbiosis with a diverse ecosystem of microbial organisms, including bacteria, viruses, and fungi. Efforts to characterize the role of these microorganisms, commonly referred as the microbiota, in human health have sought to answer the fundamental questions of what organisms are present, how are they functioning to interact with human cells, and by what mechanism are these interactions occurring. In this review, we describe recent efforts to describe the microbiota in healthy and diseased individuals, summarize the role of various molecular technologies (ranging from 16S ribosomal RNA to shotgun metagenomic sequencing) in enumerating the community structure of the microbiota, and explore known interactions between the microbiota and humans, with a focus on the microbiota’s role in hematopoiesis and hematologic diseases. PMID:26012569

  5. Hematopoiesis "awakens": Evolving technologies, the force behind them.

    PubMed

    Flores-Figueroa, Eugenia; Essers, Marieke; Bowman, Teresa V

    2016-02-01

    Amid the beauty of the Kyoto countryside, leaders in the field of hematology met at the 44th annual International Society for Experimental Hematology (ISEH) meeting in late September 2015. Led by ISEH President Paul Frenette and President-Elect David Traver, the meeting covered many aspects of hematopoiesis with a focus on technology. At the meeting, it became clear that the future of hematology is being shaped by innovations in single-cell "omics" and imaging approaches that will provide answers to age-old questions on cellular identity. In this meeting review, we highlight the advances presented in understanding the hematopoietic stem cell (HSC) niche, heterogeneity, stress response, epigenetics, and how these processes change from birth to old age. PMID:26546749

  6. Is prolonged stem cell mobilization detrimental for hematopoiesis?

    PubMed Central

    Chigaev, Alexandre; Winter, Stuart S.; Sklar, Larry A.

    2011-01-01

    Multiple hematological side effects have been reported to result from treatment with psychoactive phenothiazines. These reported toxicities include leucopenia, granulocytopenia, thrombocytopenia, agranulocytosis, and bone marrow aplasia. The physiological mechanism causing these potentially life-threatening blood dyscrasias is unknown. Recently, we discovered that phenothiazines exhibit antagonistic properties towards the VLA-4 integrin, an adhesion molecule that is responsible for homing and retention of hematological stem/progenitor cells (HSPCs) in the bone marrow. After administration of thioridazine we detected rapid mobilization of HSPCs into the peripheral blood. We propose that in patients receiving phenothiazines over a prolonged time period, continuous mobilization of stem cells out of the stem cell niche, results in a disorder of hematopoiesis. Furthermore, we also postulate that such cytopenias are caused by a loss of the niche environment, which is known to be essential for stem cell maintenance. PMID:21963354

  7. Adrenal extramedullary hematopoiesis associated with β-thalassemia major

    PubMed Central

    Keikhaei, Bijan; Shirazi, Ahmad Soltani; Pour, Mahboob Mohammad

    2012-01-01

    The presence of apparently normal hematopoietic tissue outside of bone marrow cavity is defined as extramedullary hematopoiesis (EMH). EMH is a rare complication in thalassemia major (TM) and adrenal gland as well. This report describes a case of adrenal EMH in a 26-year-old man with β-TM. He has been transfused with regular blood transfusion since 9 months. During the routine physical examination he was incidentally found to have a hypoechoic mass at his abdominal ultrasonography. Abdominal computed tomography scan revealed a right well-defined suprarenal mass 7.7×7.3×5.8 cm in size. The diagnosis of EMH was confirmed with ultrasonographic-guided fine needle biopsy. Treatment options which include intensified regular blood transfusion and hydroxyurea have been started. PMID:22826797

  8. Understanding hematopoiesis from a single-cell standpoint.

    PubMed

    Kokkaliaris, Konstantinos D; Lucas, Daniel; Beerman, Isabel; Kent, David G; Perié, Leïla

    2016-06-01

    The cellular diversity of the hematopoietic system has been extensively studied, and a plethora of cell surface markers have been used to discriminate and prospectively purify different blood cell types. However, even within phenotypically identical fractions of hematopoietic stem and progenitor cells or lineage-restricted progenitors, significant functional heterogeneity is observed when single cells are analyzed. To address these challenges, researchers are now using techniques to follow single cells and their progeny to improve our understanding of the underlying functional heterogeneity. On November 19, 2015, Dr. David Kent and Dr. Leïla Perié, two emerging young group leaders, presented their recent efforts to dissect the functional properties of individual cells with a webinar series organized by the International Society for Experimental Hematology. Here, we provide a summary of the presented methods for cell labeling and clonal tracking and discuss how these different techniques have been employed to study hematopoiesis. PMID:26997547

  9. Practical Murine Hematopathology: A Comparative Review and Implications for Research

    PubMed Central

    O'Connell, Karyn E; Mikkola, Amy M; Stepanek, Aaron M; Vernet, Andyna; Hall, Christopher D; Sun, Chia C; Yildirim, Eda; Staropoli, John F; Lee, Jeannie T; Brown, Diane E

    2015-01-01

    Hematologic parameters are important markers of disease in human and veterinary medicine. Biomedical research has benefited from mouse models that recapitulate such disease, thus expanding knowledge of pathogenetic mechanisms and investigative therapies that translate across species. Mice in health have many notable hematologic differences from humans and other veterinary species, including smaller erythrocytes, higher percentage of circulating reticulocytes or polychromasia, lower peripheral blood neutrophil and higher peripheral blood and bone marrow lymphocyte percentages, variable leukocyte morphologies, physiologic splenic hematopoiesis and iron storage, and more numerous and shorter-lived erythrocytes and platelets. For accurate and complete hematologic analyses of disease and response to investigative therapeutic interventions, these differences and the unique features of murine hematopathology must be understood. Here we review murine hematology and hematopathology for practical application to translational investigation. PMID:25926395

  10. SCL/TAL1 in Hematopoiesis and Cellular Reprogramming.

    PubMed

    Hoang, T; Lambert, J A; Martin, R

    2016-01-01

    SCL, a transcription factor of the basic helix-loop-helix family, is a master regulator of hematopoiesis. Scl specifies lateral plate mesoderm to a hematopoietic fate and establishes boundaries by inhibiting the cardiac lineage. A combinatorial interaction between Scl and Vegfa/Flk1 sets in motion the first wave of primitive hematopoiesis. Subsequently, definitive hematopoietic stem cells (HSCs) emerge from the embryo proper via an endothelial-to-hematopoietic transition controlled by Runx1, acting with Scl and Gata2. Past this stage, Scl in steady state HSCs is redundant with Lyl1, a highly homologous factor. However, Scl is haploinsufficient in stress response, when a rare subpopulation of HSCs with very long term repopulating capacity is called into action. SCL activates transcription by recruiting a core complex on DNA that necessarily includes E2A/HEB, GATA1-3, LIM-only proteins LMO1/2, LDB1, and an extended complex comprising ETO2, RUNX1, ERG, or FLI1. These interactions confer multifunctionality to a complex that can control cell proliferation in erythroid progenitors or commitment to terminal differentiation through variations in single component. Ectopic SCL and LMO1/2 expression in immature thymocytes activates of a stem cell gene network and reprogram cells with a finite lifespan into self-renewing preleukemic stem cells (pre-LSCs), an initiating event in T-cell acute lymphoblastic leukemias. Interestingly, fate conversion of fibroblasts to hematoendothelial cells requires not only Scl and Lmo2 but also Gata2, Runx1, and Erg, indicating a necessary collaboration between these transcription factors for hematopoietic reprogramming. Nonetheless, full reprogramming into self-renewing multipotent HSCs may require additional factors and most likely, a permissive microenvironment. PMID:27137657

  11. Extramedullary Hematopoiesis Presenting as a Right Adrenal Mass in a Patient With Beta Thalassemia

    PubMed Central

    Karami, Hossein; Kosaryan, Mehrnoush; Taghipour, Mehrdad; Sharifian, Rayka; Aliasgharian, Aili; Motalebi, Mohsen

    2014-01-01

    Introduction: Extramedullary hematopoiesis in the kidney and adrenal are rarely reported in medical literature and are usually found as incidentaloma. It usually occurs in patients with hematologic disorder such as thalassemia. Case Presentation: The patient was a 23-year-old Iranian man with beta thalassemia who was admitted with a suprarenal mass. Adrenal mass was detected by ultrasonography and computed tomography. Results of biochemical evaluations were insignificant. The patient underwent right adrenalectomy. Gross and microscopic histopathologic examination demonstrated extramedullary hematopoiesis without any adrenal tissue. Conclusions: To the best of our knowledge, we document the first reported case of adrenal extramedullary hematopoiesis in Iran, which seems to be rare and remarkable. PMID:25695031

  12. Smyd5 plays pivotal roles in both primitive and definitive hematopoiesis during zebrafish embryogenesis

    PubMed Central

    Fujii, Tomoaki; Tsunesumi, Shin-ichiro; Sagara, Hiroshi; Munakata, Miyo; Hisaki, Yoshihiro; Sekiya, Takao; Furukawa, Yoichi; Sakamoto, Kazuhiro; Watanabe, Sumiko

    2016-01-01

    Methylation of histone tails plays a pivotal role in the regulation of a wide range of biological processes. SET and MYND domain-containing protein (SMYD) is a methyltransferase, five family members of which have been identified in humans. SMYD1, SMYD2, SMYD3, and SMYD4 have been found to play critical roles in carcinogenesis and/or the development of heart and skeletal muscle. However, the physiological functions of SMYD5 remain unknown. To investigate the function of Smyd5 in vivo, zebrafish were utilised as a model system. We first examined smyd5 expression patterns in developing zebrafish embryos. Smyd5 transcripts were abundantly expressed at early developmental stages and then gradually decreased. Smyd5 was expressed in all adult tissues examined. Loss-of-function analysis of Smyd5 was then performed in zebrafish embryos using smyd5 morpholino oligonucleotide (MO). Embryos injected with smyd5-MO showed normal gross morphological development, including of heart and skeletal muscle. However, increased expression of both primitive and definitive hematopoietic markers, including pu.1, mpx, l-plastin, and cmyb, were observed. These phenotypes of smyd5-MO zebrafish embryos were also observed when we introduced mutations in smyd5 gene with the CRISPR/Cas9 system. As the expression of myeloid markers was elevated in smyd5 loss-of-function zebrafish, we propose that Smyd5 plays critical roles in hematopoiesis. PMID:27377701

  13. Smyd5 plays pivotal roles in both primitive and definitive hematopoiesis during zebrafish embryogenesis.

    PubMed

    Fujii, Tomoaki; Tsunesumi, Shin-Ichiro; Sagara, Hiroshi; Munakata, Miyo; Hisaki, Yoshihiro; Sekiya, Takao; Furukawa, Yoichi; Sakamoto, Kazuhiro; Watanabe, Sumiko

    2016-01-01

    Methylation of histone tails plays a pivotal role in the regulation of a wide range of biological processes. SET and MYND domain-containing protein (SMYD) is a methyltransferase, five family members of which have been identified in humans. SMYD1, SMYD2, SMYD3, and SMYD4 have been found to play critical roles in carcinogenesis and/or the development of heart and skeletal muscle. However, the physiological functions of SMYD5 remain unknown. To investigate the function of Smyd5 in vivo, zebrafish were utilised as a model system. We first examined smyd5 expression patterns in developing zebrafish embryos. Smyd5 transcripts were abundantly expressed at early developmental stages and then gradually decreased. Smyd5 was expressed in all adult tissues examined. Loss-of-function analysis of Smyd5 was then performed in zebrafish embryos using smyd5 morpholino oligonucleotide (MO). Embryos injected with smyd5-MO showed normal gross morphological development, including of heart and skeletal muscle. However, increased expression of both primitive and definitive hematopoietic markers, including pu.1, mpx, l-plastin, and cmyb, were observed. These phenotypes of smyd5-MO zebrafish embryos were also observed when we introduced mutations in smyd5 gene with the CRISPR/Cas9 system. As the expression of myeloid markers was elevated in smyd5 loss-of-function zebrafish, we propose that Smyd5 plays critical roles in hematopoiesis. PMID:27377701

  14. ROS-mediated iron overload injures the hematopoiesis of bone marrow by damaging hematopoietic stem/progenitor cells in mice.

    PubMed

    Chai, Xiao; Li, Deguan; Cao, Xiaoli; Zhang, Yuchen; Mu, Juan; Lu, Wenyi; Xiao, Xia; Li, Chengcheng; Meng, Juanxia; Chen, Jie; Li, Qing; Wang, Jishi; Meng, Aimin; Zhao, Mingfeng

    2015-01-01

    Iron overload, caused by hereditary hemochromatosis or repeated blood transfusions in some diseases, such as beta thalassemia, bone marrow failure and myelodysplastic syndrome, can significantly induce injured bone marrow (BM) function as well as parenchyma organ dysfunctions. However, the effect of iron overload and its mechanism remain elusive. In this study, we investigated the effects of iron overload on the hematopoietic stem and progenitor cells (HSPCs) from a mouse model. Our results showed that iron overload markedly decreased the ratio and clonogenic function of murine HSPCs by the elevation of reactive oxygen species (ROS). This finding is supported by the results of NAC or DFX treatment, which reduced ROS level by inhibiting NOX4 and p38MAPK and improved the long-term and multi-lineage engrafment of iron overload HSCs after transplantation. Therefore, all of these data demonstrate that iron overload injures the hematopoiesis of BM by enhancing ROS through NOX4 and p38MAPK. This will be helpful for the treatment of iron overload in patients with hematopoietic dysfunction. PMID:25970748

  15. Identification of novel mRNA transcripts of the nm23-M1 gene that are modulated during mouse embryo development and are differently expressed in adult murine tissues.

    PubMed

    Gervasi, F; Capozza, F; Bruno, T; Fanciulli, M; Lombardi, D

    1998-12-01

    The nm23-M1, a putative metastasis-suppressor gene, and its homologs are involved in development and differentiation. We have shown previously that in vitro neuronal cell proliferation and differentiation can be modulated by nm23-M1 expression levels. In the present study, by the yeast two-hybrid system, we have shown that, at the onset of mouse tissue differentiation, the Nm23-M1 protein forms either homodimers, or heterodimers with Nm23-M2. Furthermore, we have isolated two cDNA variants of the nm23-M1 gene in the 3'-untranslated region (UTR). The two variants related to novel mRNA transcripts that are modulated in mouse embryo and are differently expressed in adult murine tissues. PMID:9881672

  16. Clonal hematopoiesis of indeterminate potential and its distinction from myelodysplastic syndromes

    PubMed Central

    Bejar, Rafael; Jaiswal, Siddhartha; Lindsley, R. Coleman; Sekeres, Mikkael A.; Hasserjian, Robert P.; Ebert, Benjamin L.

    2015-01-01

    Recent genetic analyses of large populations have revealed that somatic mutations in hematopoietic cells leading to clonal expansion are commonly acquired during human aging. Clonally restricted hematopoiesis is associated with an increased risk of subsequent diagnosis of myeloid or lymphoid neoplasia and increased all-cause mortality. Although myelodysplastic syndromes (MDS) are defined by cytopenias, dysplastic morphology of blood and marrow cells, and clonal hematopoiesis, most individuals who acquire clonal hematopoiesis during aging will never develop MDS. Therefore, acquisition of somatic mutations that drive clonal expansion in the absence of cytopenias and dysplastic hematopoiesis can be considered clonal hematopoiesis of indeterminate potential (CHIP), analogous to monoclonal gammopathy of undetermined significance and monoclonal B-cell lymphocytosis, which are precursor states for hematologic neoplasms but are usually benign and do not progress. Because mutations are frequently observed in healthy older persons, detection of an MDS-associated somatic mutation in a cytopenic patient without other evidence of MDS may cause diagnostic uncertainty. Here we discuss the nature and prevalence of CHIP, distinction of this state from MDS, and current areas of uncertainty regarding diagnostic criteria for myeloid malignancies. PMID:25931582

  17. Emergence of Clonal Hematopoiesis in the Majority of Patients with Acquired Aplastic Anemia

    PubMed Central

    Babushok, Daria V.; Perdigones, Nieves; Perin, Juan C.; Olson, Timothy S.; Ye, Wenda; Roth, Jacquelyn J.; Lind, Curt; Cattier, Carine; Li, Yimei; Hartung, Helge; Paessler, Michele E.; Frank, Dale M.; Xie, Hongbo M.; Cross, Shanna; Cockroft, Joshua D.; Podsakoff, Gregory M.; Monos, Dimitrios; Biegel, Jaclyn A.; Mason, Philip J.; Bessler, Monica

    2015-01-01

    Acquired aplastic anemia (aAA) is a non-malignant disease caused by autoimmune destruction of early hematopoietic cells. Clonal hematopoiesis is a late complication, seen in 20–25% of older patients. We hypothesized that clonal hematopoiesis in aAA is a more general phenomenon, which can arise early in disease even in younger patients. To evaluate clonal hematopoiesis in aAA, we used comparative whole exome sequencing of paired bone marrow and skin in 22 patients. We found somatic mutations in sixteen patients (72.7%) with a median disease duration of 1 year; twelve (66.7%) were patients with pediatriconset aAA. Fifty-eight mutations in 51 unique genes were primarily in pathways of immunity and transcriptional regulation. Most frequently mutated was PIGA, with 7 mutations. Only two mutations were in genes recurrently-mutated in MDS. Two patients had oligoclonal loss of HLA alleles, linking immune escape to clone emergence. Two patients had activating mutations in key signaling pathways (STAT5B(p.N642H), CAMK2G(p.T306M)). Our results suggest that clonal hematopoiesis in aAA is common, with two mechanisms emerging― immune escape and increased proliferation. Our findings expand conceptual understanding of this non-neoplastic blood disorder. Future prospective studies of clonal hematopoiesis in aAA will be critical for understanding outcomes, and for designing personalized treatment strategies. PMID:25800665

  18. Identification and Characterization of Genes Involved in Embryonic Crystal Cell Formation During Drosophila Hematopoiesis

    PubMed Central

    Milchanowski, Allison B.; Henkenius, Amy L.; Narayanan, Maya; Hartenstein, Volker; Banerjee, Utpal

    2004-01-01

    Parallels between vertebrate and Drosophila hematopoiesis add to the value of flies as a model organism to gain insights into blood development. The Drosophila hematopoietic system is composed of at least three classes of terminally differentiated blood cells: plasmatocytes, crystal cells, and lamellocytes. Recent studies have identified transcriptional and signaling pathways in Drosophila involving proteins similar to those seen in human blood development. To identify additional genes involved in Drosophila hematopoiesis, we have conducted a P-element-based genetic screen to isolate mutations that affect embryonic crystal cell development. Using a marker of terminally differentiated crystal cells, we screened 1040 P-element-lethal lines located on the second and third chromosomes and identified 44 individual lines that affect crystal cell development. Identifying novel genes and pathways involved in Drosophila hematopoiesis is likely to provide further insights into mammalian hematopoietic development and disorders. PMID:15454546

  19. Spliceosomal gene mutations in myelodysplasia: molecular links to clonal abnormalities of hematopoiesis

    PubMed Central

    Inoue, Daichi; Bradley, Robert K.; Abdel-Wahab, Omar

    2016-01-01

    Genomic analyses of the myeloid malignancies and clonal disorders of hematopoiesis that may give rise to these disorders have identified that mutations in genes encoding core spliceosomal proteins and accessory regulatory splicing factors are among the most common targets of somatic mutations. These spliceosomal mutations often occur in a mutually exclusive manner with one another and, in aggregate, account for the most frequent class of mutations in patients with myelodysplastic syndromes (MDSs) in particular. Although substantial progress has been made in understanding the effects of several of these mutations on splicing and splice site recognition, functional connections linking the mechanistic changes in splicing induced by these mutations to the phenotypic consequences of clonal and aberrant hematopoiesis are not yet well defined. This review describes our current understanding of the mechanistic and biological effects of spliceosomal gene mutations in MDSs as well as the regulation of splicing throughout normal hematopoiesis. PMID:27151974

  20. Reliable Genetic Labeling of Adult-Born Dentate Granule Cells Using Ascl1CreERT2 and GlastCreERT2 Murine Lines

    PubMed Central

    Yang, Sung M.; Alvarez, Diego D.

    2015-01-01

    Newly generated dentate granule cells (GCs) are relevant for input discrimination in the adult hippocampus. Yet, their precise contribution to information processing remains unclear. To address this question, it is essential to develop approaches to precisely label entire cohorts of adult-born GCs. In this work, we used genetically modified mice to allow conditional expression of tdTomato (Tom) in adult-born GCs and characterized their development and functional integration. Ascl1CreERT2;CAGfloxStopTom and GlastCreERT2;CAGfloxStopTom mice resulted in indelible expression of Tom in adult neural stem cells and their lineage upon tamoxifen induction. Whole-cell recordings were performed to measure intrinsic excitability, firing behavior, and afferent excitatory connectivity. Developing GCs were also staged by the expression of early and late neuronal markers. The slow development of adult-born GCs characterized here is consistent with previous reports using retroviral approaches that have revealed that a mature phenotype is typically achieved after 6–8 weeks. Our findings demonstrate that Ascl1CreERT2 and GlastCreERT2 mouse lines enable simple and reliable labeling of adult-born GC lineages within restricted time windows. Therefore, these mice greatly facilitate tagging new neurons and manipulating their activity, required for understanding adult neurogenesis in the context of network remodeling, learning, and behavior. SIGNIFICANCE STATEMENT Our study shows that Ascl1CreERT2 and GlastCreERT2 mice lines can be used to label large cohorts of adult-born dentate granule cells with excellent time resolution. Neurons labeled in this manner display developmental and functional profiles that are in full agreement with previous findings using thymidine analogs and retroviral labeling, thus providing an alternative approach to tackle fundamental questions on circuit remodeling. Because of the massive neuronal targeting and the simplicity of this method, genetic labeling will

  1. Reporter gene technologies for imaging cell fates in hematopoiesis.

    PubMed

    Kusy, Sophie; Contag, Christopher H

    2014-01-01

    Advances in noninvasive imaging technologies that allow for in vivo dynamic monitoring of cells and cellular function in living research subjects have revealed new insights into cell biology in the context of intact organs and their native environment. In the field of hematopoiesis and stem cell research, studies of cell trafficking involved in injury repair and hematopoietic engraftment have made great progress using these new tools. Stem cells present unique challenges for imaging since after transplantation, they proliferate dramatically and differentiate. Therefore, the imaging modality used needs to have a large dynamic range, and the genetic regulatory elements used need to be stably expressed during differentiation. Multiple imaging technologies using different modalities are available, and each varies in sensitivity, ease of data acquisition, signal to noise ratios (SNR), substrate availability, and other parameters that affect utility for monitoring cell fates and function. For a given application, there may be several different approaches that can be used. For mouse models, clinically validated technologies such as magnetic resonance imaging (MRI) and positron emission tomography (PET) have been joined by optical imaging techniques such as in vivo bioluminescence imaging (BLI) and fluorescence imaging (FLI), and all have been used to monitor bone marrow and stem cells after transplantation into mice. Photoacoustic imaging that utilizes the sound created by the thermal expansion of absorbed light to generate an image best represents hybrid technologies. Each modality requires that the cells of interest be marked with a genetic reporter that acts as a label making them uniquely visible using that technology. For each modality, there are several labels to choose from. Multiple methods for applying these different labels are available. This chapter provides an overview of the imaging technologies and commonly used labels for each, as well as detailed

  2. Inhibitory effects of homeodomain-interacting protein kinase 2 on the aorta-gonad-mapharsen hematopoiesis

    SciTech Connect

    Ohtsu, Naoki; Nobuhisa, Ikuo; Mochita, Miyuki; Taga, Tetsuya . E-mail: taga@kaiju.medic.kumamoto-u.ac.jp

    2007-01-01

    Definitive hematopoiesis starts in the aorta-gonad-mesonephros (AGM) region of the mouse embryo. Our previous studies revealed that STAT3, a gp130 downstream transcription factor, is required for AGM hematopoiesis and that homeodomain-interacting protein kinase 2 (HIPK2) phosphorylates serine-727 of STAT3. HIPK2 is a serine/threonine kinase known to be involved in transcriptional repression and apoptosis. In the present study, we examined the role of HIPK2 in hematopoiesis in mouse embryo. HIPK2 transcripts were found in fetal hematopoietic tissues such as the mouse AGM region and fetal liver. In cultured AGM cells, HIPK2 protein was detected in adherent cells. Functional analyses of HIPK2 were carried out by introducing wild-type and mutant HIPK2 constructs into AGM cultures. Production of CD45{sup +} hematopoietic cells was suppressed by forced expression of HIPK2 in AGM cultures. This suppression required the kinase domain and nuclear localization signals of HIPK2, but the kinase activity was dispensable. HIPK2-overexpressing AGM-derived nonadherent cells did not form cobblestone-like colonies in cultures with stromal cells. Furthermore, overexpression of HIPK2 in AGM cultures impeded the expansion of CD45{sup low}c-Kit{sup +} cells, which exhibit the immature hematopoietic progenitor phenotype. These data indicate that HIPK2 plays a negative regulatory role in AGM hematopoiesis in the mouse embryo.

  3. Dysregulated in vitro hematopoiesis, radiosensitivity, proliferation, and osteoblastogenesis with marrow from SAMP6 mice.

    PubMed

    O'Sullivan, Regina P; Greenberger, Joel S; Goff, Julie; Cao, Shaonan; Kingston, Kiera A; Zhou, Shuanhu; Dixon, Tracy; Houghton, Frank D; Epperly, Michael W; Wang, Hong; Glowacki, Julie

    2012-06-01

    The senescence accelerated-prone mouse variant 6 (SAMP6) shows normal growth followed by rapid aging, development of osteopenia, and shortened lifespan, compared with control R1 mice. Because oxidative stress is a fundamental mechanism of tissue aging, we tested whether cellular parameters that are associated with oxidative stress are impaired with marrow from SAMP6 mice. We compared in vitro hematopoiesis, irradiation sensitivity, proliferative potential, and osteoblastogenesis with marrow cells from SAMP6 and R1 mice. Marrow cells from SAMP6 mice showed shortened in vitro hematopoiesis; their stromal cells showed greater radiation sensitivity and decreased proliferation. Consistent with those properties, there was constitutive upregulation of transforming growth factor-β(1), an inhibitor of hematopoiesis, and of cell cycle inhibitory genes, p16(INK4A) and p19(ARF). Paradoxically, there was constitutive expression of osteoblast genes in stromal cells from SAMP6 mice, but in vitro matrix mineralization was impaired. These studies and data included in other reports indicate that impaired proliferation of osteoblast progenitors in SAMP6 marrow may be a major factor contributing to accelerated loss of bone mass. In sum, marrow from SAMP6 mice had diminished capacity for long-term hematopoiesis, increased radiosensitivity, and reduced proliferative capacity. PMID:22326715

  4. Dysregulated in vitro Hematopoiesis, Radiosensitivity, Proliferation, and Osteoblastogenesis with Marrow from SAMP6 Mice

    PubMed Central

    O’Sullivan, Regina P.; Greenberger, Joel S.; Goff, Julie; Cao, Shaonan; Kingston, Kiera A.; Zhou, Shuanhu; Dixon, Tracy; Houghton, Frank D.; Epperly, Michael W.; Wang, Hong; Glowacki, Julie

    2012-01-01

    The Senescence Accelerated-Prone mouse variant 6 (SAMP6) shows normal growth followed by rapid aging, development of osteopenia, and shortened lifespan, compared with control R1 mice. Because oxidative stress is a fundamental mechanism of tissue aging, we tested whether cellular parameters that are associated with oxidative stress are impaired with marrow from SAMP6 mice. We compared in vitro hematopoiesis, irradiation sensitivity, proliferative potential, and osteoblastogenesis with marrow cells from SAMP6 and R1 mice. Marrow cells from SAMP6 mice showed shortened in vitro hematopoiesis; their stromal cells showed greater radiation sensitivity and decreased proliferation. Consistent with those properties, there was constitutive upregulation of TGF-β1, an inhibitor of hematopoiesis, and of cell cycle inhibitory genes, p16INK4A and p19ARF. Paradoxically, there was constitutive expression of osteoblast genes in stromal cells from SAMP6 mice, but in vitro matrix mineralization was impaired. These studies and data included in other reports indicate that impaired proliferation of osteoblast progenitors in SAMP6 marrow may be a major factor contributing to accelerated loss of bone mass. In sum, marrow from SAMP6 mice had diminished capacity for long-term hematopoiesis, increased radiosensitivity, and reduced proliferative capacity. PMID:22326715

  5. A method for high purity intestinal epithelial cell culture from adult human and murine tissues for the investigation of innate immune function

    PubMed Central

    Graves, Christina L.; Harden, Scott W.; LaPato, Melissa; Nelson, Michael; Amador, Byron; Sorenson, Heather; Frazier, Charles J.; Wallet, Shannon M.

    2015-01-01

    Intestinal epithelial cells (IECs) serve as an important physiologic barrier between environmental antigens and the host intestinal immune system. Thus, IECs serve as a first line of defense and may act as sentinel cells during inflammatory insults. Despite recent renewed interest in IEC contributions to host immune function, the study of primary IEC has been hindered by lack of a robust culture technique, particularly for small intestinal and adult tissues. Here, a novel adaptation for culture of primary IEC is described for human duodenal organ donor tissue as well as duodenum and colon of adult mice. These epithelial cell cultures display characteristic phenotypes and are of high purity. In addition, the innate immune function of human primary IEC, specifically with regard to Toll-like receptor (TLR) expression and microbial ligand responsiveness, is contrasted with a commonly used intestinal epithelial cell line (HT-29). Specifically, TLR expression at the mRNA level and production of cytokine (IFNγ and TNFα) in response to TLR agonist stimulation is assessed. Differential expression of TLRs as well as innate immune responses to ligand stimulation is observed in human-derived cultures compared to that of HT-29. Thus, use of this adapted method to culture primary epithelial cells from adult human donors and from adult mice will allow for more appropriate studies of IECs as innate immune effectors. PMID:25193428

  6. Phenotypic, Morphological and Adhesive Differences of Human Hematopoietic Progenitor Cells Cultured on Murine versus Human Mesenchymal Stromal Cells

    PubMed Central

    Reichert, Doreen; Friedrichs, Jens; Ritter, Steffi; Käubler, Theresa; Werner, Carsten; Bornhäuser, Martin; Corbeil, Denis

    2015-01-01

    Xenogenic transplantation models have been developed to study human hematopoiesis in immunocompromised murine recipients. They still have limitations and therefore it is important to delineate all players within the bone marrow that could account for species-specific differences. Here, we evaluated the proliferative capacity, morphological and physical characteristics of human CD34+ hematopoietic stem and progenitor cells (HSPCs) after co-culture on murine or human bone marrow-derived mesenchymal stromal cells (MSCs). After seven days, human CD34+CD133– HSPCs expanded to similar extents on both feeder layers while cellular subsets comprising primitive CD34+CD133+ and CD133+CD34– phenotypes are reduced fivefold on murine MSCs. The number of migrating HSPCs was also reduced on murine cells suggesting that MSC adhesion influences cellular polarization of HSPC. We used atomic force microscopy-based single-cell force spectroscopy to quantify their adhesive interactions. We found threefold higher detachment forces of human HSPCs from murine MSCs compared to human ones. This difference is related to the N-cadherin expression level on murine MSCs since its knockdown abolished their differential adhesion properties with human HSPCs. Our observations highlight phenotypic, morphological and adhesive differences of human HSPCs when cultured on murine or human MSCs, which raise some caution in data interpretation when xenogenic transplantation models are used. PMID:26498381

  7. 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

    2016-01-01

    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. PMID:26699484

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

    PubMed Central

    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

    2016-01-01

    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. PMID:26699484

  9. Elk3 deficiency causes transient impairment in post-natal retinal vascular development and formation of tortuous arteries in adult murine retinae.

    PubMed

    Weinl, Christine; Wasylyk, Christine; Garcia Garrido, Marina; Sothilingam, Vithiyanjali; Beck, Susanne C; Riehle, Heidemarie; Stritt, Christine; Roux, Michel J; Seeliger, Mathias W; Wasylyk, Bohdan; Nordheim, Alfred

    2014-01-01

    Serum Response Factor (SRF) fulfills essential roles in post-natal retinal angiogenesis and adult neovascularization. These functions have been attributed to the recruitment by SRF of the cofactors Myocardin-Related Transcription Factors MRTF-A and -B, but not the Ternary Complex Factors (TCFs) Elk1 and Elk4. The role of the third TCF, Elk3, remained unknown. We generated a new Elk3 knockout mouse line and showed that Elk3 had specific, non-redundant functions in the retinal vasculature. In Elk3(-/-) mice, post-natal retinal angiogenesis was transiently delayed until P8, after which it proceeded normally. Interestingly, tortuous arteries developed in Elk3(-/-) mice from the age of four weeks, and persisted into late adulthood. Tortuous vessels have been observed in human pathologies, e.g. in ROP and FEVR. These human disorders were linked to altered activities of vascular endothelial growth factor (VEGF) in the affected eyes. However, in Elk3(-/-) mice, we did not observe any changes in VEGF or several other potential confounding factors, including mural cell coverage and blood pressure. Instead, concurrent with the post-natal transient delay of radial outgrowth and the formation of adult tortuous arteries, Elk3-dependent effects on the expression of Angiopoietin/Tie-signalling components were observed. Moreover, in vitro microvessel sprouting and microtube formation from P10 and adult aortic ring explants were reduced. Collectively, these results indicate that Elk3 has distinct roles in maintaining retinal artery integrity. The Elk3 knockout mouse is presented as a new animal model to study retinal artery tortuousity in mice and human patients. PMID:25203538

  10. Elk3 Deficiency Causes Transient Impairment in Post-Natal Retinal Vascular Development and Formation of Tortuous Arteries in Adult Murine Retinae

    PubMed Central

    Weinl, Christine; Wasylyk, Christine; Garcia Garrido, Marina; Sothilingam, Vithiyanjali; Beck, Susanne C.; Riehle, Heidemarie; Stritt, Christine; Roux, Michel J.; Seeliger, Mathias W.; Wasylyk, Bohdan; Nordheim, Alfred

    2014-01-01

    Serum Response Factor (SRF) fulfills essential roles in post-natal retinal angiogenesis and adult neovascularization. These functions have been attributed to the recruitment by SRF of the cofactors Myocardin-Related Transcription Factors MRTF-A and -B, but not the Ternary Complex Factors (TCFs) Elk1 and Elk4. The role of the third TCF, Elk3, remained unknown. We generated a new Elk3 knockout mouse line and showed that Elk3 had specific, non-redundant functions in the retinal vasculature. In Elk3(−/−) mice, post-natal retinal angiogenesis was transiently delayed until P8, after which it proceeded normally. Interestingly, tortuous arteries developed in Elk3(−/−) mice from the age of four weeks, and persisted into late adulthood. Tortuous vessels have been observed in human pathologies, e.g. in ROP and FEVR. These human disorders were linked to altered activities of vascular endothelial growth factor (VEGF) in the affected eyes. However, in Elk3(−/−) mice, we did not observe any changes in VEGF or several other potential confounding factors, including mural cell coverage and blood pressure. Instead, concurrent with the post-natal transient delay of radial outgrowth and the formation of adult tortuous arteries, Elk3-dependent effects on the expression of Angiopoietin/Tie-signalling components were observed. Moreover, in vitro microvessel sprouting and microtube formation from P10 and adult aortic ring explants were reduced. Collectively, these results indicate that Elk3 has distinct roles in maintaining retinal artery integrity. The Elk3 knockout mouse is presented as a new animal model to study retinal artery tortuousity in mice and human patients. PMID:25203538

  11. Epigenetic therapy restores normal hematopoiesis in a zebrafish model of NUP98-HOXA9-induced myeloid disease.

    PubMed

    Deveau, A P; Forrester, A M; Coombs, A J; Wagner, G S; Grabher, C; Chute, I C; Léger, D; Mingay, M; Alexe, G; Rajan, V; Liwski, R; Hirst, M; Steigmaier, K; Lewis, S M; Look, A T; Berman, J N

    2015-10-01

    Acute myeloid leukemia (AML) occurs when multiple genetic aberrations alter white blood cell development, leading to hyperproliferation and arrest of cell differentiation. Pertinent animal models link in vitro studies with the use of new agents in clinical trials. We generated a transgenic zebrafish expressing human NUP98-HOXA9 (NHA9), a fusion oncogene found in high-risk AML. Embryos developed a preleukemic state with anemia and myeloid cell expansion, and adult fish developed a myeloproliferative neoplasm (MPN). We leveraged this model to show that NHA9 increases the number of hematopoietic stem cells, and that oncogenic function of NHA9 depends on downstream activation of meis1, the PTGS/COX pathway and genome hypermethylation through the DNA methyltransferase, dnmt1. We restored normal hematopoiesis in NHA9 embryos with knockdown of meis1 or dnmt1, as well as pharmacologic treatment with DNA (cytosine-5)-methyltransferase (DNMT) inhibitors or cyclo-oxygenase (COX) inhibitors. DNMT inhibitors reduced genome methylation to near normal levels. Strikingly, we discovered synergy when we combined sub-monotherapeutic doses of a histone deacetylase inhibitor plus either a DNMT inhibitor or COX inhibitor to block the effects of NHA9 on zebrafish blood development. Our work proposes novel drug targets in NHA9-induced myeloid disease, and suggests rational therapies by combining minimal doses of known bioactive compounds. PMID:26017032

  12. In utero transplantation of adult bone marrow decreases perinatal lethality and rescues the bone phenotype in the knockin murine model for classical, dominant osteogenesis imperfecta.

    PubMed

    Panaroni, Cristina; Gioia, Roberta; Lupi, Anna; Besio, Roberta; Goldstein, Steven A; Kreider, Jaclynn; Leikin, Sergey; Vera, Juan Carlos; Mertz, Edward L; Perilli, Egon; Baruffaldi, Fabio; Villa, Isabella; Farina, Aurora; Casasco, Marco; Cetta, Giuseppe; Rossi, Antonio; Frattini, Annalisa; Marini, Joan C; Vezzoni, Paolo; Forlino, Antonella

    2009-07-01

    Autosomal dominant osteogenesis imperfecta (OI) caused by glycine substitutions in type I collagen is a paradigmatic disorder for stem cell therapy. Bone marrow transplantation in OI children has produced a low engraftment rate, but surprisingly encouraging symptomatic improvements. In utero transplantation (IUT) may hold even more promise. However, systematic studies of both methods have so far been limited to a recessive mouse model. In this study, we evaluated intrauterine transplantation of adult bone marrow into heterozygous BrtlIV mice. Brtl is a knockin mouse with a classical glycine substitution in type I collagen [alpha1(I)-Gly349Cys], dominant trait transmission, and a phenotype resembling moderately severe and lethal OI. Adult bone marrow donor cells from enhanced green fluorescent protein (eGFP) transgenic mice engrafted in hematopoietic and nonhematopoietic tissues differentiated to trabecular and cortical bone cells and synthesized up to 20% of all type I collagen in the host bone. The transplantation eliminated the perinatal lethality of heterozygous BrtlIV mice. At 2 months of age, femora of treated Brtl mice had significant improvement in geometric parameters (P < .05) versus untreated Brtl mice, and their mechanical properties attained wild-type values. Our results suggest that the engrafted cells form bone with higher efficiency than the endogenous cells, supporting IUT as a promising approach for the treatment of genetic bone diseases. PMID:19414862

  13. Femur Window Chamber Model for In Vivo Cell Tracking in the Murine Bone Marrow.

    PubMed

    Chen, Yonghong; Maeda, Azusa; Bu, Jiachuan; DaCosta, Ralph

    2016-01-01

    Bone marrow is a complex organ that contains various hematopoietic and non-hematopoietic cells. These cells are involved in many biological processes, including hematopoiesis, immune regulation and tumor regulation. Commonly used methods for understanding cellular actions in the bone marrow, such as histology and blood counts, provide static information rather than capturing the dynamic action of multiple cellular components in vivo. To complement the standard methods, a window chamber (WC)-based model was developed to enable serial in vivo imaging of cells and structures in the murine bone marrow. This protocol describes a surgical procedure for installing the WC in the femur, in order to facilitate long-term optical access to the femoral bone marrow. In particular, to demonstrate its experimental utility, this WC approach was used to image and track neutrophils within the vascular network of the femur, thereby providing a novel method to visualize and quantify immune cell trafficking and regulation in the bone marrow. This method can be applied to study various biological processes in the murine bone marrow, such as hematopoiesis, stem cell transplantation, and immune responses in pathological conditions, including cancer. PMID:27500928

  14. Role of the clathrin adaptor PICALM in normal hematopoiesis and polycythemia vera pathophysiology

    PubMed Central

    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

    2015-01-01

    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 Jak2V617F 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. PMID:25552701

  15. EphB2 and EphB3 play an important role in the lymphoid seeding of murine adult thymus.

    PubMed

    Alfaro, David; García-Ceca, Javier; Farias-de-Oliveira, Desio A; Terra-Granado, Eugenia; Montero-Herradón, Sara; Cotta-de-Almeida, Vinicius; Savino, Wilson; Zapata, Agustín

    2015-12-01

    Adult thymuses lacking either ephrin type B receptor 2 (EphB2) or EphB3, or expressing a truncated form of EphB2, the forward signal-deficient EphB2LacZ, have low numbers of early thymic progenitors (ETPs) and are colonized in vivo by reduced numbers of injected bone marrow (BM) lineage-negative (Lin(-)) cells. Hematopoietic progenitors from these EphB mutants showed decreased capacities to colonize wild type (WT) thymuses compared with WT precursors, with EphB2(-/-) cells exhibiting the greatest reduction. WT BM Lin(-) cells also showed decreased colonizing capacity into mutant thymuses. The reduction was also more severe in EphB2(-/-) host thymuses, with a less severe phenotype in the EphB2LacZ thymus. These results suggest a major function for forward signaling through EphB2 and, to a lesser extent, EphB3, in either colonizing progenitor cells or thymic stromal cells, for in vivo adult thymus recruitment. Furthermore, the altered expression of the molecules involved in thymic colonization that occurs in the mutant thymus correlates with the observed colonizing capacities of different mutant mice. Reduced production of CCL21 and CCL25 occurred in the thymus of the 3 EphB-deficient mice, but their expression, similar to that of P-selectin, on blood vessels, the method of entry of progenitor cells into the vascular thymus, only showed a significant reduction in EphB2(-/-) and EphB3(-/-) thymuses. Decreased migration into the EphB2(-/-) thymuses correlated also with reduced expression of both ephrinB1 and ephrinB2, without changes in the EphB2LacZ thymuses. In the EphB3(-/-) thymuses, only ephrinB1 expression appeared significantly diminished, confirming the relevance of forward signals mediated by the EphB2-ephrinB1 pair in cell recruitment into the adult thymus. PMID:25810451

  16. Adult murine prostate basal and luminal cells are self-sustained lineages that can both serve as targets for prostate cancer initiation

    PubMed Central

    Choi, Nahyun; Zhang, Boyu; Zhang, Li; Ittmann, Michael; Xin, Li

    2012-01-01

    Summary The prostate epithelial lineage hierarchy and the cellular origin for prostate cancer remain inadequately defined. Using a lineage tracing approach, we show that adult rodent prostate basal and luminal cells are independently self-sustained in vivo. Disrupting the tumor suppressor Pten in either lineage led to prostate cancer initiation. However, the cellular composition and onset dynamics of the resulting tumors are distinctive. Prostate luminal cells are more responsive to Pten null-induced mitogenic signaling. In contrast, basal cells are resistant to direct transformation. Instead, loss of Pten activity induces the capability of basal cells to differentiate into transformation-competent luminal cells. Our study suggests that deregulation of epithelial differentiation is a critical step for the initiation of prostate cancers of basal cell origin. PMID:22340597

  17. Vaccination of adult and newborn mice of a resistant strain (C57BL/6J) against challenge with leukemias induced by Moloney murine leukemia virus

    SciTech Connect

    Reif, A.E.

    1985-01-01

    Adult or newborn C57BL/6J mice were immunized with isogenic Moloney strain MuLV-induced leukemia cells irradiated with 10,000 rads or treated with low concentrations of formalin. Groups of immunized and control mice were challenged with a range of doses of viable leukemia cells, and tumor deaths were recorded for 90 days after challenge. Then, the doses of challenge cells which produced 50% tumor deaths were calculated for immunized and control mice. The logarithm of their ratio quantified the degree of protection provided by immunization. For adult C57BL/6J mice, a single immunization with MuLV-induced leukemia cells was not effective; either cells plus Bacillus Calmette-Guerin or Corynebacterium parvum, or else two immunizations with irradiated leukemia cells were needed to produce statistically significant increases in the values of the doses of challenge cells which produced 50% tumor deaths. Cross-protection was obtained by immunization with other isogenic MuLV-induced leukemias, but not by immunization with isogenic carcinogen-induced tumors or with an isogenic spontaneous leukemia. For newborn mice, a single injection of irradiated leukemia cells provided 1.3 to 1.5 logs of protection, and admixture of B. Calmette-Guerin or C. parvum increased this protection to 2.4 to 2.7 logs. Since irradiated and frozen-thawed MuLV-induced leukemia cells contained viable MuLV, leukemia cells treated with 0.5 or 1.0% formalin were tested as an alternative. A single injection of formalin-treated isogenic leukemia cells admixed with C. parvum provided between 1.7 and 2.8 logs of protection. These results demonstrate that a single vaccination of newborn animals against a highly antigenic virally induced leukemia produces strong protection against a subsequent challenge with viable leukemia cells.

  18. Sympathoadrenergic modulation of hematopoiesis: a review of available evidence and of therapeutic perspectives

    PubMed Central

    Cosentino, Marco; Marino, Franca; Maestroni, Georges J. M.

    2015-01-01

    Innervation of the bone marrow (BM) has been described more than one century ago, however the first in vivo evidence that sympathoadrenergic fibers have a role in hematopoiesis dates back to less than 25 years ago. Evidence has since increased showing that adrenergic nerves in the BM release noradrenaline and possibly also dopamine, which act on adrenoceptors and dopaminergic receptors (DR) expressed on hematopoietic cells and affect cell survival, proliferation, migration and engraftment ability. Remarkably, dysregulation of adrenergic fibers to the BM is associated with hematopoietic disturbances and myeloproliferative disease. Several adrenergic and dopaminergic agents are already in clinical use for non-hematological indications and with a usually favorable risk-benefit profile, and are therefore potential candidates for non-conventional modulation of hematopoiesis. PMID:26300737

  19. Pro-inflammatory cytokines: emerging players regulating HSC function in normal and diseased hematopoiesis

    PubMed Central

    Mirantes, Cristina; Passegué, Emmanuelle; Pietras, Eric M.

    2014-01-01

    Hematopoiesis is the hierarchical process in which all lineages of blood cells are produced by self-renewing hematopoietic stem cells (HSCs) in the bone marrow (BM). While the regulatory factors that maintain proper HSC function and lineage output under normal conditions are well understood, significantly less is known about how HSC fate is regulated in response to inflammation or disease. As many blood disorders are associated with overproduction of pro-inflammatory cytokines, significant interest has emerged in understanding the impact of these factors on HSC function. In this review we highlight key advances demonstrating the impact of pro-inflammatory cytokines on the biology of HSCs and the BM niche, and address ongoing questions regarding their role in normal and pathogenic hematopoiesis. PMID:25149680

  20. Cocaine exposure impairs multineage hematopoiesis of human hematopoietic progenitor cells mediated by the sigma-1 receptor

    PubMed Central

    Nixon, Christopher C.; Schwartz, Brandon H.; Dixit, Dhaval; Zack, Jerome A.; Vatakis, Dimitrios N.

    2015-01-01

    Prenatal exposure to cocaine is a significant source of fetal and neonatal developmental defects. While cocaine associated neurological and cardiac pathologies are well-documented, it is apparent that cocaine use has far more diverse physiological effects. It is known that in some cell types, the sigma-1 receptor mediates many of cocaine's cellular effects. Here we present a novel and concise investigation into the mechanism that underlies cocaine associated hematopoietic pathology. Indeed, this is the first examination of the effects of cocaine on hematopoiesis. We show that cocaine impairs multilineage hematopoiesis from human progenitors from multiple donors and tissue types. We go on to present the first demonstration of the expression of the sigma-1 receptor in human CD34 + human hematopoietic stem/progenitor cells. Furthermore, we demonstrate that these cocaine-induced hematopoietic defects can be reversed through sigma-1 receptor blockade. PMID:25728014

  1. From hematopoiesis to neuropoiesis: Evidence of overlapping genetic programs

    PubMed Central

    Terskikh, Alexey V.; Easterday, Mathew C.; Li, Linheng; Hood, Leroy; Kornblum, Harley I.; Geschwind, Daniel H.; Weissman, Irving L.

    2001-01-01

    It is reasonable to propose that gene expression profiles of purified stem cells could give clues for the molecular mechanisms of stem cell behavior. We took advantage of cDNA subtraction to identify a set of genes selectively expressed in mouse adult hematopoietic stem cells (HSC) as opposed to bone marrow (BM). Analysis of HSC-enriched genes revealed several key regulatory gene candidates, including two novel seven transmembrane (7TM) receptors. Furthermore, by using cDNA microarray techniques we found a large set of HSC-enriched genes that are expressed in mouse neurospheres (a population greatly enriched for neural progenitor cells), but not present in terminally differentiated neural cells. In situ hybridization demonstrated that many of them, including one HSC-enriched 7TM receptor, were selectively expressed in the germinal zones of fetal and adult brain, the regions harboring mouse neural stem cells. We propose that at least some of the transcripts that are selectively and commonly expressed in two or more types of stem cells define a functionally conserved group of genes evolved to participate in basic stem cell functions, including stem cell self-renewal. PMID:11438738

  2. Microarray Analysis of Gene Expression Reveals that Cyclo-oxygenase-2 Gene Therapy Up-regulates Hematopoiesis and Down-regulates Inflammation During Endochondral Bone Fracture Healing

    PubMed Central

    Lau, K.-H. William; Popa, Nicoleta L.

    2014-01-01

    Background Cyclo-oxygenase-2 (Cox-2) is an inflammatory mediator that is necessary for the tissue repair, including bone fracture healing. Although the application of Cox-2 gene therapy to a murine closed femoral fracture has accelerated bony union, but the beneficial effect was not observed until the endochondral stage of bone repair that is well after the inflammatory stage normally subsides. Methods To identify the molecular pathways through which Cox-2 regulates fracture healing, we examined gene expression profile in fracture tissues in response to Cox-2 gene therapy during the endochondral bone repair phase. Cox-2 gene therapy was applied to the closed murine femur fracture model. Microarray analysis was performed at 10 days post-fracture to examine global gene expression profile in the fracture tissues during the endochondral bone repair phase. The entire repertoire of significantly expressed genes was examined by gene set enrichment analysis, and the most up-regulated individual genes were evaluated further. Results The genes that normally promote inflammation were under-represented in the microarray analysis, and the expression of several inflammatory chemokines was significantly down-regulated. There was an up-regulation of two key transcription factor genes that regulate hematopoiesis and erythropoiesis. More surprisingly, there was no significant up-regulation in the genes that are normally involved in angiogenesis or bone formation. However, the expression of two tissue remodeling genes was up-regulated. Conclusions The down-regulation of the inflammatory genes in response to Cox-2 gene therapy was unexpected, given the pro-inflammatory role of prostaglandins. Cox-2 gene therapy could promote bony union through hematopoietic precursor proliferation during endochondral bone repair and thereby enhances subsequently fracture callus remodeling that leads to bony union of the fracture gap. PMID:25247155

  3. BCR/ABL Directly Inhibits Expression of SHIP, an SH2-Containing Polyinositol-5-Phosphatase Involved in the Regulation of Hematopoiesis

    PubMed Central

    Sattler, Martin; Verma, Shalini; Byrne, Christopher H.; Shrikhande, Gautam; Winkler, Thomas; Algate, Paul A.; Rohrschneider, Larry R.; Griffin, James D.

    1999-01-01

    The BCR/ABL oncogene causes chronic myelogenous leukemia (CML), a myeloproliferative disorder characterized by clonal expansion of hematopoietic progenitor cells and granulocyte lineage cells. The SH2-containing inositol-5-phosphatase SHIP is a 145-kDa protein which has been shown to regulate hematopoiesis in mice. Targeted disruption of the murine SHIP gene results in a myeloproliferative syndrome characterized by a dramatic increase in numbers of granulocyte-macrophage progenitor cells in the marrow and spleen. Also, hematopoietic progenitor cells from SHIP−/− mice are hyperresponsive to certain hematopoietic growth factors, a phenotype very similar to the effects of BCR/ABL in murine cells. In a series of BCR/ABL-transformed hematopoietic cell lines, Philadelphia chromosome (Ph)-positive cell lines, and primary cells from patients with CML, the expression of SHIP was found to be absent or substantially reduced compared to untransformed cell lines or leukemia cells lacking BCR/ABL. Ba/F3 cells in which expression of BCR/ABL was under the control of a tetracycline-inducible promoter showed rapid loss of p145 SHIP, coincident with induction of BCR/ABL expression. Also, an ABL-specific tyrosine kinase inhibitor, CGP57148B (STI571), rapidly caused reexpression of SHIP, indicating that BCR/ABL directly, but reversibly, regulates the expression of SHIP protein. The estimated half-life of SHIP protein was reduced from 18 h to less than 3 h. However, SHIP mRNA also decreased in response to BCR/ABL, suggesting that SHIP protein levels could be affected by more than one mechanism. Reexpression of SHIP in BCR/ABL-transformed Ba/F3 cells altered the biological behavior of cells in culture. The reduction of SHIP due to BCR/ABL is likely to directly contribute to the pathogenesis of CML. PMID:10523635

  4. Impact of fluorescent silicon nanoparticles on circulating hemolymph and hematopoiesis in an invertebrate model organism.

    PubMed

    Xing, Rui; Li, Kai-Le; Zhou, Yan-Feng; Su, Yuan-Yuan; Yan, Si-Qi; Zhang, Kai-Long; Wu, Si-Cong; Sima, Yang-Hu; Zhang, Ke-Qin; He, Yao; Xu, Shi-Qing

    2016-09-01

    Silicon nanoparticles (SiNPs) have attractive potential applications in biological and medical fields, and yet their impact on animals is still controversial, and there have been no reports of their effects on hematopoiesis. In this study, the effects of SiNPs on hemocytes and hematopoiesis were investigated by administering SiNPs via a vascular injection into an invertebrate model, the silkworm. Our results show that the ability of SiNPs to enter different types of circulating hemocytes and their impact on those hemocytes differed significantly. Rapid accumulation of SiNPs was observed in granulocytes, oenocytoids, and spherulocytes, which have immune functions in the circulating hemolymph, whereas SiNPs did not easily enter prohemocytes, which can differentiate into granulocytes, oenocytoids, and spherulocytes and replenish them. The SiNPs that entered the hemocytes initiated autophagy and apoptosis via the lysosomal/mitochondrial pathway. High-dose SiNPs weakly stimulated lysosomal activity in hematopoietic organs, but did not lead to a significant increase in reactive oxygen species or severe autophagy or apoptosis in the organ tissues. We suggest that the damage caused by high-dose SiNPs to hematopoiesis is self-healing, because few SiNPs entered the hematopoietic stem cells in the circulating hemolymph, so the damage to the hematopoietic tissues was limited. PMID:27348562

  5. [Chronic myelogenous leukemia initially presenting with multiple subcutaneous tumors due to extramedullary hematopoiesis].

    PubMed

    Kurosawa, Shuhei; Doki, Noriko; Kaito, Satoshi; Sakaguchi, Masahiro; Harada, Kaito; Hino, Yutaro; Yamamoto, Keita; Ikegawa, Shuntaro; Yosioka, Kosuke; Watanabe, Daisuke; Senoo, Yasushi; Watakabe, Kyoko; Hagino, Takeshi; Igarashi, Aiko; Najima, Yuho; Kobayashi, Takeshi; Kakihana, Kazuhiko; Miyawaki, Shuichi; Sakamaki, Hisashi; Ohashi, Kazuteru

    2016-04-01

    A 53-year-old woman was admitted with right upper-extremity pain and multiple subcutaneous masses. Bone marrow aspirate showed hypercellular marrow with increased myeloid components at all stages of maturation. Cytogenetic analysis of the bone marrow revealed 100% Philadelphia chromosome positivity along with BCR/ABL gene rearrangement, as demonstrated by polymerase chain reaction (PCR). A diagnosis of chronic phase of chronic myeloid leukemia (CML) was therefore made. Biopsy of one of the subcutaneous masses showed proliferation of granulocytes in various stages of differentiation. There were also erythroid cells and megakaryocytes, without p53 and CD34-positive blasts. These results suggested that the subcutaneous masses had developed from extramedullary hematopoiesis, not blastomas. The patient was administered dasatinib (DA) 140 mg, combined with radiation therapy for pain and peripheral neuropathy from the right axial extramedullary tumor. The patient showed complete hematological remission and the subcutaneous masses had disappeared 1 month after starting administration of DA. Because the patient did not achieve a cytogenetic response, the tyrosine kinase inhibitor nilotinib was administered. She will undergo allogeneic stem cell transplantation in the near future. Extramedullary hematopoiesis in the early stages of CML is uncommon. Our case emphasizes the need to elucidate the pathogenesis of extramedullary hematopoiesis in the early stages of CML. PMID:27169451

  6. Reactive Oxygen Species Affect Transglutaminase Activity and Regulate Hematopoiesis in a Crustacean.

    PubMed

    Junkunlo, Kingkamon; Söderhäll, Kenneth; Söderhäll, Irene; Noonin, Chadanat

    2016-08-19

    Reactive oxygen species (ROS) serve as a prime signal in the commitment to hematopoiesis in both mammals and Drosophila In this study, the potential function of ROS during hematopoiesis in the crayfish Pacifastacus leniusculus was examined. The antioxidant N-acetylcysteine (NAC) was used to decrease ROS in both in vivo and in vitro experiments. An increase in ROS was observed in the anterior proliferation center (APC) after LPS injection. In the absence of NAC, the LPS-induced increase in ROS levels resulted in the rapid restoration of the circulating hemocyte number. In the presence of NAC, a delay in the recovery rate of the hemocyte number was observed. NAC treatment also blocked the spread of APC and other hematopoietic tissue (HPT) cells, maintaining these cells at an undifferentiated stage. Extracellular transglutaminase (TGase) has been shown previously to play a role in maintaining HPT cells in an undifferentiated form. In this study, we show that extracellular TGase activity increased when the ROS level in HPT or APC cells was reduced after NAC treatment. In addition, collagen, a major component of the extracellular matrix and a TGase substrate were co-localized on the HPT cell surface. Taken together, the results of this study show that ROS are involved in crayfish hematopoiesis, in which a low ROS level is required to maintain hematopoietic progenitor cells in the tissue and to reduce hemocyte release. The potential roles of TGase in this process are investigated and discussed. PMID:27339892

  7. Cloning of murine ferrochelatase.

    PubMed Central

    Brenner, D A; Frasier, F

    1991-01-01

    Ferrochelatase (protoheme ferro-lyase, EC 4.99.1.1) catalyzes the last step in the heme biosynthetic pathway, the chelation of ferrous iron and protoporphyrin to form heme. The activity of ferrochelatase is deficient in the inherited disease protoporphyria. In this study, murine ferrochelatase cDNAs were obtained by screening cDNA libraries with an oligonucleotide probe. The derived amino acid sequence of murine ferrochelatase has 47% identity with the recently cloned Saccharomyces cerevisiae ferrochelatase, but it is not significantly similar to other published sequences. Results of Southern blotting are consistent with a single murine ferrochelatase gene, while Northern blotting demonstrates two ferrochelatase transcripts in all tissues examined. The ferrochelatase protein and mRNAs have different relative concentrations in different tissues. The cloning of murine ferrochelatase cDNAs provides the basis for future studies on ferrochelatase gene expression and on the identification of the molecular defect in protoporphyria. Images PMID:1704134

  8. Effective treatment of a murine model of adult T-cell leukemia using 211At-7G7/B6 and its combination with unmodified anti-Tac (daclizumab) directed toward CD25.

    PubMed

    Zhang, Zhuo; Zhang, Meili; Garmestani, Kayhan; Talanov, Vladimir S; Plascjak, Paul S; Beck, Barbara; Goldman, Carolyn; Brechbiel, Martin W; Waldmann, Thomas A

    2006-08-01

    Adult T-cell leukemia (ATL) consists of an overabundance of T cells, which express CD25. Therapeutic efficacy of astatine-211 ((211)At)-labeled murine monoclonal antibody 7G7/B6 alone and in combination with daclizumab was evaluated in nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice given injections of MET-1 human T-cell leukemia cells. Daclizumab and 7G7/B6 are directed toward different epitopes of CD25. Either a single dose of 12 microCi (0.444 MBq) (211)At-7G7/B6 per mouse given intravenously or receptor-saturating doses of daclizumab given at 100 microg weekly for 4 weeks intravenously inhibited tumor growth as monitored by serum levels of human beta-2 microglobulin (beta(2)mu) and by prolonged survival of leukemia-bearing mice compared with the control groups (P < .001). The combination of 2 agents enhanced the antitumor effect when compared with groups treated with 12 microCi (0.444 MBq) of (211)At-7G7/B6 (P < .05) or daclizumab alone (P < .05). The median survival duration of the PBS group was 62.6 days and 61.5 days in the radiolabeled nonspecific antibody (211)At-11F11-treated group. In contrast, 91% of mice in the combination group survived through day 94. These results that demonstrate a significantly improved therapeutic efficacy by combining (211)At-7G7/B6 with daclizumab support a clinical trial of this regimen in patients with ATL. PMID:16569769

  9. Isolation and expansion of adult cardiac stem/progenitor cells in the form of cardiospheres from human cardiac biopsies and murine hearts.

    PubMed

    Chimenti, Isotta; Gaetani, Roberto; Barile, Lucio; Forte, Elvira; Ionta, Vittoria; Angelini, Francesco; Frati, Giacomo; Messina, Elisa; Giacomello, Alessandro

    2012-01-01

    The successful isolation and ex vivo expansion of resident cardiac stem/progenitor cells from human heart biopsies has allowed us to study their biological characteristics and their applications in therapeutic approaches for the repair of ischemic/infarcted heart, the preparation of tissue-engineered cardiac grafts and, possibly, the design of cellular kits for drug screening applications. From the first publication of the original method in 2004, several adjustments and slight changes have been introduced to optimize and adjust the procedure to the evolving experimental and translational needs. Moreover, due to the wide applicability of such a method (which is based on the exploitation of intrinsic functional properties of cells with regenerative properties that are present in most tissues), the key steps of this procedure have been used to derive several kinds of tissue-specific adult stem cells for preclinical or clinical purposes.In order to define the original procedure, complete with the up-to-date modifications introduced through the years, an exhaustive description of the current protocol is performed in this chapter, with particular attention in highlighting critical steps and troubleshoots. The procedure described here consists of modular steps, that could be employed to derive cells from any kind of tissue biopsy, and needs to be considered the gold standard of all the so-called "explant methods" or "cardiosphere methods," and it represents a milestone in the clinical translation of autologous cell therapy. PMID:22610568

  10. Sense and antisense transcripts of the developmentally regulated murine hsp70.2 gene are expressed in distinct and only partially overlapping areas in the adult brain

    NASA Technical Reports Server (NTRS)

    Murashov, A. K.; Wolgemuth, D. J.

    1996-01-01

    We have examined the spatial pattern of expression of a member of the hsp70 gene family, hsp70.2, in the mouse central nervous system. Surprisingly, RNA blot analysis and in situ hybridization revealed abundant expression of an 'antisense' hsp70.2 transcript in several areas of adult mouse brain. Two different transcripts recognized by sense and antisense riboprobes for the hsp70.2 gene were expressed in distinct and only partially overlapping neuronal populations. RNA blot analysis revealed low levels of the 2.7 kb transcript of hsp70.2 in several areas of the brain, with highest signal in the hippocampus. Abundant expression of a slightly larger (approximately 2.8 kb) 'antisense' transcript was detected in several brain regions, notably in the brainstem, cerebellum, mesencephalic tectum, thalamus, cortex, and hippocampus. In situ hybridization revealed that the sense and antisense transcripts were both predominantly neuronal and localized to the same cell types in the granular layer of the cerebellum, trapezoid nucleus of the superior olivary complex, locus coeruleus and hippocampus. The hsp70.2 antisense transcripts were particularly abundant in the frontal cortex, dentate gyrus, subthalamic nucleus, zona incerta, superior and inferior colliculi, central gray, brainstem, and cerebellar Purkinje cells. Our findings have revealed a distinct cellular and spatial localization of both sense and antisense transcripts, demonstrating a new level of complexity in the function of the heat shock genes.

  11. Fate Mapping and Quantitation of Hematopoiesis In Vivo.

    PubMed

    Höfer, Thomas; Busch, Katrin; Klapproth, Kay; Rodewald, Hans-Reimer

    2016-05-20

    Hematopoietic stem cells (HSCs) and downstream progenitors have long been studied based on phenotype, cell purification, proliferation, and transplantation into myeloablated recipients. These experiments, complemented by data on expression profiles, mouse mutants, and humans with hematopoietic defects, are the foundation for the current hematopoietic differentiation tree. However, there are fundamental gaps in our knowledge of the quantitative and qualitative operation of the HSC/progenitor system under physiological and pathological conditions in vivo. The hallmarks of HSCs, self-renewal and multipotency, are observed in in vitro assays and cell transplantation experiments; however, the extent to which these features occur naturally in HSCs and progenitors remains uncertain. We focus here on work that strives to address these unresolved questions, with emphasis on fate mapping and modeling of the hematopoietic flow from stem cells toward myeloid and lymphoid lineages during development and adult life. PMID:27168243

  12. Epigenome-wide DNA methylation analysis implicates neuronal and inflammatory signaling pathways in adult murine hepatic tumorigenesis following perinatal exposure to bisphenol A.

    PubMed

    Weinhouse, Caren; Sartor, Maureen A; Faulk, Christopher; Anderson, Olivia S; Sant, Karilyn E; Harris, Craig; Dolinoy, Dana C

    2016-07-01

    Developmental exposure to the endocrine-active compound bisphenol A (BPA) has been linked to epigenotoxic and potential carcinogenic effects in rodent liver, prostate, and mammary glands. A dose-dependent increase in hepatic tumors in 10-month mice perinatally exposed to one of three doses of BPA (50 ng, 50 µg, or 50 mg BPA/kg chow) was previously reported. These tumors represent early-onset disease and lack classical sexual dimorphism in incidence. Here, adult epigenome-wide liver DNA methylation profiles to identify gene promoters associated with perinatal BPA exposure and disease in 10-month mice with and without liver tumors were investigated. Mice with hepatic tumors showed 12,822 (1.8%) probes with differential methylation as compared with non-tumor animals, of which 8,656 (67.5%) were hypomethylated. A significant enrichment of differential methylation in Gene Ontology (GO) terms and biological processes related to morphogenesis and development, and epigenomic alteration were observed. Pathway enrichment revealed a predominance of hypermethylated neuronal signaling pathways linked to energy regulation and metabolic function, supporting metabolic consequences in the liver via BPA-induced disruption of neuronal signaling pathways. Hypothesis-driven pathway analysis revealed mouse and human genes linked to BPA exposure related to intracellular Jak/STAT and MAPK signaling pathways. Taken together, these findings are indicators of the relevance of the hepatic tumor phenotype seen in BPA-exposed mice to human health. This work demonstrated that epigenome-wide discovery experiments in animal models were effective tools for identification and understanding of paralagous epimutations salient to human disease. Environ. Mol. Mutagen. 57:435-446, 2016. © 2016 Wiley Periodicals, Inc. PMID:27334623

  13. Human and Murine Hematopoietic Stem Cell Aging Is Associated with Functional Impairments and Intrinsic Megakaryocytic/Erythroid Bias

    PubMed Central

    Rundberg Nilsson, Alexandra; Soneji, Shamit; Adolfsson, Sofia; Bryder, David; Pronk, Cornelis Jan

    2016-01-01

    Aging within the human hematopoietic system associates with various deficiencies and disease states, including anemia, myeloid neoplasms and reduced adaptive immune responses. Similar phenotypes are observed in mice and have been linked to alterations arising at the hematopoietic stem cell (HSC) level. Such an association is, however, less established in human hematopoiesis and prompted us here to detail characteristics of the most primitive human hematopoietic compartments throughout ontogeny. In addition, we also attempted to interrogate similarities between aging human and murine hematopoiesis. Coupled to the transition from human cord blood (CB) to young and aged bone marrow (BM), we observed a gradual increase in frequency of candidate HSCs. This was accompanied by functional impairments, including decreased lymphoid output and reduced proliferative potential. Downstream of human HSCs, we observed decreasing levels of common lymphoid progenitors (CLPs), and increasing frequencies of megakaryocyte/erythrocyte progenitors (MEPs) with age, which could be linked to changes in lineage-affiliated gene expression patterns in aged human HSCs. These findings were paralleled in mice. Therefore, our data support the notion that age-related changes also in human hematopoiesis involve the HSC pool, with a prominent skewing towards the megakaryocytic/erythroid lineages, and suggests conserved mechanisms underlying aging of the blood cell system. PMID:27368054

  14. 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

  15. Osseous metaplasia and mature bone formation with extramedullary hematopoiesis in follicular adenoma of thyroid gland.

    PubMed

    Harsh, Mohan; Dimri, Parul; Nagarkar, Nitin M

    2009-01-01

    Follicular adenomas of the thyroid may be subjected to degenerative changes like hemorrhagic and cystic changes, fibrosis, and calcification. Mature bone formation is a rare phenomenon, but extramedullary hematopoiesis (EMH) has also been rarely reported in thyroid gland. The combination of mature bone formation and EMH is rarer and has been reported, in a single case report, in a multinodular goitre. We describe a case of follicular adenoma with histologically proven osseous metaplasia and mature bone formation with EMH in a middle- aged woman, which, to our knowledge, is the first case in English language literature. PMID:19679966

  16. Human and murine erythropoiesis

    PubMed Central

    An, Xiuli; Schulz, Vincent P.; Mohandas, Narla; Gallagher, Patrick G.

    2015-01-01

    Purpose of review Research into the fundamental mechanisms of erythropoiesis has provided critical insights into inherited and acquired disorders of the erythrocyte. Studies of human erythropoiesis have primarily utilized in-vitro systems, whereas murine models have provided insights from in-vivo studies. This report reviews recent insights into human and murine erythropoiesis gained from transcriptome-based analyses. Recent findings The availability of high-throughput genomic methodologies has allowed attainment of detailed gene expression data from cells at varying developmental and differentiation stages of erythropoiesis. Transcriptome analyses of human and murine reveal both stage and species-specific similarities and differences across terminal erythroid differentiation. Erythroid-specific long noncoding RNAs exhibit poor sequence conservation between human and mouse. Genome-wide analyses of alternative splicing reveal that complex, dynamic, stage-specific programs of alternative splicing program are utilized during terminal erythroid differentiation. Transcriptome data provide a significant resource for understanding mechanisms of normal and perturbed erythropoiesis. Understanding these processes will provide innovative strategies to detect, diagnose, prevent, and treat hematologic disease. Summary Understanding the shared and different mechanisms controlling human and murine erythropoiesis will allow investigators to leverage the best model system to provide insights in normal and perturbed erythropoiesis. PMID:25719574

  17. Modeling Hematopoiesis and Responses to Radiation Countermeasures in a Bone Marrow-on-a-Chip.

    PubMed

    Torisawa, Yu-Suke; Mammoto, Tadanori; Jiang, Elisabeth; Jiang, Amanda; Mammoto, Akiko; Watters, Alexander L; Bahinski, Anthony; Ingber, Donald E

    2016-05-01

    Studies on hematopoiesis currently rely on animal models because in vitro culture methods do not accurately recapitulate complex bone marrow physiology. We recently described a bone marrow-on-a-chip microfluidic device that enables the culture of living hematopoietic bone marrow and mimics radiation toxicity in vitro. In the present study, we used this microdevice to demonstrate continuous blood cell production in vitro and model bone marrow responses to potential radiation countermeasure drugs. The device maintained mouse hematopoietic stem and progenitor cells in normal proportions for at least 2 weeks in culture. Increases in the number of leukocytes and red blood cells into the microfluidic circulation also could be detected over time, and addition of erythropoietin induced a significant increase in erythrocyte production. Exposure of the bone marrow chip to gamma radiation resulted in reduction of leukocyte production, and treatment of the chips with two potential therapeutics, granulocyte-colony stimulating factor or bactericidal/permeability-increasing protein (BPI), induced significant increases in the number of hematopoietic stem cells and myeloid cells in the fluidic outflow. In contrast, BPI was not found to have any effect when analyzed using static marrow cultures, even though it has been previously shown to accelerate recovery from radiation-induced toxicity in vivo. These findings demonstrate the potential value of the bone marrow-on-a-chip for modeling blood cell production, monitoring responses to hematopoiesis-modulating drugs, and testing radiation countermeasures in vitro. PMID:26993746

  18. TopBP1 Governs Hematopoietic Stem/Progenitor Cells Survival in Zebrafish Definitive Hematopoiesis

    PubMed Central

    Gao, Lei; Li, Dantong; Ma, Ke; Zhang, Wenjuan; Xu, Tao; Fu, Cong; Jing, Changbin; Jia, Xiaoe; Wu, Shuang; Sun, Xin; Dong, Mei; Deng, Min; Chen, Yi; Zhu, Wenge; Peng, Jinrong; Wan, Fengyi; Zhou, Yi; Zon, Leonard I.; Pan, Weijun

    2015-01-01

    In vertebrate definitive hematopoiesis, nascent hematopoietic stem/progenitor cells (HSPCs) migrate to and reside in proliferative hematopoietic microenvironment for transitory expansion. In this process, well-established DNA damage response pathways are vital to resolve the replication stress, which is deleterious for genome stability and cell survival. However, the detailed mechanism on the response and repair of the replication stress-induced DNA damage during hematopoietic progenitor expansion remains elusive. Here we report that a novel zebrafish mutantcas003 with nonsense mutation in topbp1 gene encoding topoisomerase II β binding protein 1 (TopBP1) exhibits severe definitive hematopoiesis failure. Homozygous topbp1cas003 mutants manifest reduced number of HSPCs during definitive hematopoietic cell expansion, without affecting the formation and migration of HSPCs. Moreover, HSPCs in the caudal hematopoietic tissue (an equivalent of the fetal liver in mammals) in topbp1cas003 mutant embryos are more sensitive to hydroxyurea (HU) treatment. Mechanistically, subcellular mislocalization of TopBP1cas003 protein results in ATR/Chk1 activation failure and DNA damage accumulation in HSPCs, and eventually induces the p53-dependent apoptosis of HSPCs. Collectively, this study demonstrates a novel and vital role of TopBP1 in the maintenance of HSPCs genome integrity and survival during hematopoietic progenitor expansion. PMID:26131719

  19. A Quantitative Proteomic Analysis of Hemogenic Endothelium Reveals Differential Regulation of Hematopoiesis by SOX17.

    PubMed

    Clarke, Raedun L; Robitaille, Aaron M; Moon, Randall T; Keller, Gordon

    2015-08-11

    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

  20. Hematopoiesis toxicity induced by 4-methylumbelliferon determined in an invertebrate model organism.

    PubMed

    Fang, Yan; He, Yue; Wang, Hua; Yan, Siqi; Xing, Rui; Yin, Weimin; Sima, Yanghu; Xu, Shiqing

    2016-04-01

    Umbelliferone has potential value as it has an inhibitory effect on tumor cells; however, its impact on an animal's circulatory system and hematopoietic function has not been reported. In this study, 4-methylumbelliferon (4-MU), an umbelliferone derivative, was used as a model drug, and its potential toxicity on hemocytes and hematopoietic organs (HOs) was investigated using an invertebrate animal model, the silkworm, Bombyx mori. The results showed that the level of reactive oxygen species in HOs increased when larvae (third day of the fifth instar) were orally exposed to 4 mM 4-MU for 8 min, followed by the induction of improved antioxidative metabolism of coenzymes in hemolymph. Exposure to 4-MU also significantly upregulated the expression levels of several genes in the hemolymph and fat body (a detoxification tissue similar to the liver in mammals) including antimicrobial peptide gene cecropinA and moricin, and a phagocytosis-related gene, tetraspanin E, suggesting an increased antioxidant level and antimicrobial ability of the circulatory system. However, the percentage of dead hemocytes increased and hematopoiesis significantly decreased in HOs, indicating the toxic effect of 4-MU on hemocytes and hematopoiesis, despite it inducing enhanced antioxidant and antimicrobial activity in the circulatory system. PMID:26327572

  1. Murine hematopoietic reconstitution after tagging and selection of retrovirally transduced bone marrow cells

    PubMed Central

    García-Hernández, B.; Castellanos, A.; López, A.; Orfao, A.; Sánchez-García, I.

    1997-01-01

    A major problem facing the effective treatment of patients with cancer is how to get the specific antitumor agent into every tumor cell. In this report we describe the use of a strategy that, by using retroviral vectors encoding a truncated human CD5 cDNA, allows the selection of only the infected cells, and we show the ability to obtain, before bone marrow transplantation, a population of 5-fluouraci-treated murine bone marrow cells that are 100% marked. This marked population of bone marrow cells is able to reconstitute the hematopoietic system in lethally irradiated mice, indicating that the surface marker lacks deleterious effects on the functionality of bone marrow cells. No gross abnormalities in hematopoiesis were detected in mice repopulated with CD5-expressing cells. Nevertheless, a significant proportion of the hematopoietic cells no longer expresses the surface marker CD5 in the 9-month-old recipient mice. This transcriptional inactivity of the proviral long terminal repeat (LTR) was accompanied by de novo methylation of the proviral sequences. Our results show that the use of the CD5 as a retrovirally encoded marker enables the rapid, efficient, and nontoxic selection in vitro of infected primary cells, which can entirely reconstitute the hematopoietic system in mice. These results should now greatly enhance the power of studies aimed at addressing questions such as generation of cancer-negative hematopoiesis. PMID:9371830

  2. Expression of the erythropoietin receptor by germline-derived cells - further support for a potential developmental link between the germline and hematopoiesis

    PubMed Central

    2014-01-01

    Background Expressing several markers of migrating primordial germ cells (PGCs), the rare population of quiescent, bone marrow (BM)-residing very small embryonic-like stem cells (VSELs) can be specified like PGCs into hematopoietic stem/progenitor cells (HSPCs). These two properties of VSELs support the possibility of a developmental origin of HSPCs from migrating PGCs. Methods To address a potential link between VSELs and germ line cells we analyzed by RT-PCR and FACS expression of erythropoietin receptor (EpoR) on murine bone marrow- and human umbilical cord blood-derived VSELs, murine and human teratocarcinoma cell lines and human ovarian cancer cells. A proper gating strategy and immunostaining excluded from FACS analysis potential contamination by erythroblasts. Furthermore, the transwell chemotaxis assays as well as adhesion and signaling studies were performed to demonstrate functionality of erythropoietin - EpoR axes on these cells. Results We report here that murine and human VSELs as well as murine and human teratocarcinoma cell lines and ovarian cancer cell lines share a functional EpoR. Conclusions Our data provide more evidence of a potential developmental link between germline cells, VSELs, and HSCs and sheds more light on the developmental hierarchy of the stem cell compartment in adult tissues. PMID:24982693

  3. Development and characterization of antiserum to murine granulocyte-macrophage colony-stimulating factor

    SciTech Connect

    Mochizuki, D.Y.; Eisenman, J.R.; Conlon, P.J.; Park, L.S.; Urdal, D.L.

    1986-05-15

    The expression in yeast of a cDNA clone encoding murine granulocyte-macrophage colony-stimulating factor (GM-CSF) has made possible the purification of large quantities of this recombinant protein. Rabbits immunized with pure recombinant GM-CSF generated antibodies that were shown to be specific for both recombinant GM-CSF and GM-CSF isolated from natural sources. Other lymphokines, including IL 1..beta.., IL 2, IL 3, and recombinant human GM-CSF did not react with the antiserum. The antiserum together with recombinant GM-CSF that had been radiolabeled with /sup 125/I to high specific activity, formed the foundation for a rapid, sensitive, and quantitative radioimmunoassay specific for murine GM-CSF. Furthermore, the antiserum was found to inhibit the biologic activities of GM-CSF as measured in both a bone marrow proliferation assay and a colony assay, and thus should prove to be a useful reagent for dissecting the complex growth factor activities involved in murine hematopoiesis.

  4. Hematopoietic Stem/Progenitor Cells Express Several Functional Sex Hormone Receptors—Novel Evidence for a Potential Developmental Link Between Hematopoiesis and Primordial Germ Cells

    PubMed Central

    Mierzejewska, Katarzyna; Borkowska, Sylwia; Suszynska, Ewa; Suszynska, Malwina; Poniewierska-Baran, Agata; Maj, Magda; Pedziwiatr, Daniel; Adamiak, Mateusz; Abdel-Latif, Ahmed; Kakar, Sham S.; Ratajczak, Janina; Kucia, Magda

    2015-01-01

    Evidence has accumulated that hematopoietic stem progenitor cells (HSPCs) share several markers with the germline, a connection supported by reports that prolactin, androgens, and estrogens stimulate hematopoiesis. To address this issue more directly, we tested the expression of receptors for pituitary-derived hormones, such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH), on purified murine bone marrow (BM) cells enriched for HSPCs and tested the functionality of these receptors in ex vivo signal transduction studies and in vitro clonogenic assays. We also tested whether administration of pituitary- and gonad-derived sex hormones (SexHs) increases incorporation of bromodeoxyuridine (BrdU) into HSPCs and expansion of hematopoietic clonogenic progenitors in mice and promotes recovery of blood counts in sublethally irradiated animals. We report for the first time that HSPCs express functional FSH and LH receptors and that both proliferate in vivo and in vitro in response to stimulation by pituitary SexHs. Furthermore, based on our observations that at least some of CD45− very small embryonic-like stem cells (VSELs) may become specified into CD45+ HSPCs, we also evaluated the expression of pituitary and gonadal SexHs receptors on these cells and tested whether these quiescent cells may expand in vivo in response to SexHs administration. We found that VSELs express SexHs receptors and respond in vivo to SexHs stimulation, as evidenced by BrdU accumulation. Since at least some VSELs share several markers characteristic of migrating primordial germ cells and can be specified into HSPCs, this observation sheds new light on the BM stem cell hierarchy. PMID:25607657

  5. c-kit mRNA expression in human and murine hematopoietic cell lines.

    PubMed

    André, C; d'Auriol, L; Lacombe, C; Gisselbrecht, S; Galibert, F

    1989-08-01

    The c-kit proto-oncogene belongs to the tyrosine kinase receptor family. Although its ligand is still unknown, there is increasing evidence to suggest its involvement in hematopoiesis. In order to detect lineage or differentiation related specificity, we have studied c-kit mRNA expression in both human and murine hematopoietic organs and cell lines. We show that c-kit mRNA expression is found at early stages of erythroid and myeloid differentiation. There is however, no evidence of c-kit expression in the lymphoid lineage. Our results suggest a possible role for c-kit as a receptor in the early stages of the erythroid/myeloid differentiation. PMID:2474787

  6. Clonal hematopoiesis as determined by the HUMARA assay is a marker for acquired mutations in epigenetic regulators in older women.

    PubMed

    Wiedmeier, Julia Erin; Kato, Catherine; Zhang, Zhenzhen; Lee, Hyunjung; Dunlap, Jennifer; Nutt, Eric; Rattray, Rogan; McKay, Sarah; Eide, Christopher; Press, Richard; Mori, Motomi; Druker, Brian; Dao, Kim-Hien

    2016-09-01

    Recent large cohort studies revealed that healthy older individuals harbor somatic mutations that increase their risk for hematologic malignancy and all-cause cardiovascular deaths. The majority of these mutations are in chromatin and epigenetic regulatory genes (CERGs). CERGs play a key role in regulation of DNA methylation (DNMT3A and TET2) and histone function (ASXL1) and in clonal proliferation of hematopoietic stem cells. We hypothesize that older women manifesting clonal hematopoiesis, defined here as a functional phenomenon in which a hematopoietic stem cell has acquired a survival and proliferative advantage, harbor a higher frequency of somatic mutations in CERGs. The human androgen receptor gene (HUMARA) assay was used in our study to detect the presence of nonrandom X inactivation in women, a marker for clonal hematopoiesis. In our pilot study, we tested 127 blood samples from women ≥65 years old without a history of invasive cancer or hematologic malignancies. Applying stringent qualitative criteria, we found that 26% displayed clonal hematopoiesis; 52.8% displayed polyclonal hematopoiesis; and 21.3% had indeterminate patterns (too close to call by qualitative assessment). Using Illumina MiSeq next-generation sequencing, we identified somatic mutations in CERGs in 15.2% of subjects displaying clonal hematopoiesis (three ASXL1 and two DNMT3A mutations with an average variant allele frequency of 15.7%, range: 6.3%-23.3%). In a more limited sequencing analysis, we evaluated the frequency of ASXL1 mutations by Sanger sequencing and found mutations in 9.7% of the clonal samples and 0% of the polyclonal samples. By comparing several recent studies (with some caveats as described), we determined the fold enrichment of detecting CERG mutations by using the HUMARA assay as a functional screen for clonal hematopoiesis. We conclude that a functional assay of clonal hematopoiesis is enriching for older women with somatic mutations in CERGs, particularly for ASXL

  7. Spinal Cord Compression Secondary to Extramedullary Hematopoiesis: Case Report and Review of the Literature.

    PubMed

    Wang, Arthur; Carberry, Nathan; Solli, Elena; Gillick, John; Islam, Humayun; Hillard, Virany

    2016-01-01

    Extramedullary hematopoiesis (EMH) is a rare cause of spinal cord compression (SCC). EMH represents the growth of blood cells outside of the bone marrow and occurs in a variety of hematologic illnesses, including various types of anemia and myeloproliferative disorders. Although EMH usually occurs in the liver, spleen, and lymph nodes, it may also occur within the spinal canal. When this occurs, the mass effect can compress the spinal cord, potentially leading to the development of neurological deficits. We present a case of SCC secondary to EMH. This report illustrates the importance of considering EMH in the differential diagnosis of SCC, even in the absence of signs of its most common etiologies. PMID:27462228

  8. Postnatal Hematopoiesis and Gut Microbiota in NOD Mice Deviate from C57BL/6 Mice

    PubMed Central

    Damlund, Dina Silke Malling; Metzdorff, Stine Broeng; Hasselby, Jane Preuss; Wiese, Maria; Lundsager, Mia; Buschard, Karsten Stig; Hansen, Axel Kornerup; Frøkiær, Hanne

    2016-01-01

    Neonatal studies in different mouse strains reveal that early life colonization affects the development of adaptive immunity in mice. The nonobese diabetic (NOD) mouse spontaneously develops autoimmune diabetes, but neonatal studies of NOD mice are lacking. We hypothesized that NOD mice deviate from another much used mouse strain, C57BL/6, with respect to postnatal microbiota and/or hematopoiesis and compared this in newborn mice of dams housed under the same conditions. A distinct bacteria profile rich in staphylococci was found at postnatal days (PND) 1–4 in NOD mice. Furthermore, a distinct splenic cell profile high in a granulocytic phenotype was evident in the neonatal NOD mice whereas neonatal C57BL/6 mice showed a profile rich in monocytes. Neonatal expression of Reg3g and Muc2 in the gut was deviating in NOD mice and coincided with fewer bacteria attaching to the Mucosal surface in NOD compared to C57BL/6 mice. PMID:26783537

  9. Extramedullary hematopoiesis within cystic renal cell carcinoma with oncocytic and chromophobe cell types: A case report

    PubMed Central

    CELIK, BETUL; BULUT, TANGUL; SEDELE, MURAT; SEZER, CEM; KARAKUS, VOLKAN

    2014-01-01

    Extramedullary hematopoiesis (EMH) is a phenomenon in which hematopoietic cells are found in sites other than the bone marrow. It is usually observed in the liver and spleen but may occasionally be found within solid tumors. The current case report presents a 69-year-old female patient who presented with a renal cyst. Histopathological examination following surgical removal of the cyst revealed a lining of oncocytic- and chromophobe-type cells with capsular invasion and a mass forming EMH with evident bone trabeculae within the cyst wall. Circulating hematopoietic stem cells in the blood and their colonization within tissues is discussed in the present case report, emphasizing certain types of renal cell carcinoma. PMID:24520308

  10. Cord Compression due to Extramedullary Hematopoiesis in an Adolescent with Known Beta Thalassemia Major

    PubMed Central

    Soman, Salil; Rosenfeld, David L; Roychowdhury, Sudipta; Drachtman, Richard A; Cohler, Alan

    2009-01-01

    We describe a 16 year-old male with β thalassemia major and gait disturbances that had not been given blood transfusions due to a severe childhood transfusion reaction. Thoracic spine MRI demonstrated hematopoietic marrow throughout the spine and epidural masses causing cord compression consistent with extramedullary hematopoiesis (EMH). After treatment with steroids, radiotherapy and monitored blood transfusions, the patient demonstrated significant improvement of his paraspinal lesions and near complete resolution of his neurological symptoms. While EMH causing cord compression in adolescents is rare in the current era of bone marrow transplantation or chronic transfusions, it should be considered when thalassemia major patients present with neurological deficits. The well defined imaging features of EMH can play a central role in its diagnosis and management, especially because surgical and / or radiotherapeutic intervention are often considered in cases of failed medical treatment. PMID:22470615

  11. Spinal Cord Compression Secondary to Extramedullary Hematopoiesis: Case Report and Review of the Literature

    PubMed Central

    Wang, Arthur; Carberry, Nathan; Solli, Elena; Gillick, John; Islam, Humayun; Hillard, Virany

    2016-01-01

    Extramedullary hematopoiesis (EMH) is a rare cause of spinal cord compression (SCC). EMH represents the growth of blood cells outside of the bone marrow and occurs in a variety of hematologic illnesses, including various types of anemia and myeloproliferative disorders. Although EMH usually occurs in the liver, spleen, and lymph nodes, it may also occur within the spinal canal. When this occurs, the mass effect can compress the spinal cord, potentially leading to the development of neurological deficits. We present a case of SCC secondary to EMH. This report illustrates the importance of considering EMH in the differential diagnosis of SCC, even in the absence of signs of its most common etiologies. PMID:27462228

  12. Endothelio-mesenchymal interaction controls runx1 expression and modulates the notch pathway to initiate aortic hematopoiesis

    PubMed Central

    Richard, Charlotte; Drevon, Cécile; Canto, Pierre-Yves; Villain, Gaelle; Bollérot, Karine; Lempereur, Aveline; Teillet, Marie-Aimée; Vincent, Christine; Castillo, Catalina Rosselló; Torres, Miguel; Piwarzyk, Eileen; Speck, Nancy A.; Souyri, Michèle; Jaffredo, Thierry

    2014-01-01

    SUMMARY Hematopoietic stem cells (HSCs) are produced by a small cohort of hemogenic endothelial cells (ECs) during development through the formation of intra-aortic hematopoietic cell (HC) clusters (HCs). The Runx1 transcription factor plays a key role in the EC to HC and HSC transition. We show that Runx1 expression in hemogenic ECs and the subsequent initiation of HC formation are tightly controlled by the sub-aortic mesenchyme, although the mesenchyme is not a source of HCs. Runx1 and Notch signaling are involved in this process, with Notch signaling decreasing with time in HCs. Inhibiting Notch signaling readily increases HC production in mouse and chicken embryos. In the mouse however, this increase is transient. Collectively, we show complementary roles of hemogenic ECs and mesenchymal compartments in triggering aortic hematopoiesis. The sub-aortic mesenchyme induces Runx1 expression in hemogenic-primed endothelial cells and collaborates with Notch dynamics to control aortic hematopoiesis. PMID:23537631

  13. Parallels between immune driven-hematopoiesis and T cell activation: 3 signals that relay inflammatory stress to the bone marrow

    SciTech Connect

    Libregts, Sten F.W.M.; Nolte, Martijn A.

    2014-12-10

    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 on 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.

  14. Germ line variants predispose to both JAK2 V617F clonal hematopoiesis and myeloproliferative neoplasms.

    PubMed

    Hinds, David A; Barnholt, Kimberly E; Mesa, Ruben A; Kiefer, Amy K; Do, Chuong B; Eriksson, Nicholas; Mountain, Joanna L; Francke, Uta; Tung, Joyce Y; Nguyen, Huong Marie; Zhang, Haiyu; Gojenola, Linda; Zehnder, James L; Gotlib, Jason

    2016-08-25

    We conducted a genome-wide association study (GWAS) to identify novel predisposition alleles associated with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and JAK2 V617F clonal hematopoiesis in the general population. We recruited a web-based cohort of 726 individuals with polycythemia vera, essential thrombocythemia, and myelofibrosis and 252 637 population controls unselected for hematologic phenotypes. Using a single-nucleotide polymorphism (SNP) array platform with custom probes for the JAK2 V617F mutation (V617F), we identified 497 individuals (0.2%) among the population controls who were V617F carriers. We performed a combined GWAS of the MPN cases plus V617F carriers in the control population (n = 1223) vs the remaining controls who were noncarriers for V617F (n = 252 140). For these MPN cases plus V617F carriers, we replicated the germ line JAK2 46/1 haplotype (rs59384377: odds ratio [OR] = 2.4, P = 6.6 × 10(-89)), previously associated with V617F-positive MPN. We also identified genome-wide significant associations in the TERT gene (rs7705526: OR = 1.8, P = 1.1 × 10(-32)), in SH2B3 (rs7310615: OR = 1.4, P = 3.1 × 10(-14)), and upstream of TET2 (rs1548483: OR = 2.0, P = 2.0 × 10(-9)). These associations were confirmed in a separate replication cohort of 446 V617F carriers vs 169 021 noncarriers. In a joint analysis of the combined GWAS and replication results, we identified additional genome-wide significant predisposition alleles associated with CHEK2, ATM, PINT, and GFI1B All SNP ORs were similar for MPN patients and controls who were V617F carriers. These data indicate that the same germ line variants endow individuals with a predisposition not only to MPN, but also to JAK2 V617F clonal hematopoiesis, a more common phenomenon that may foreshadow the development of an overt neoplasm. PMID:27365426

  15. Expression profile analysis of aorta-gonad-mesonephros region-derived stromal cells reveals genes that regulate hematopoiesis

    SciTech Connect

    Nagao, Kenji; Ohta, Takayuki; Hinohara, Atsushi; Tahara, Tomoyuki; Hagiwara, Tetsuya; Maeda, Yoshitake; Yoneya, Takashi; Sohma, Yoshiaki; Heike, Toshio; Nakahata, Tatsutoshi; Inagaki, Yoshimasa Nishikawa, Mitsuo

    2008-12-05

    The aorta-gonad-mesonephros (AGM) region is involved in the generation and maintenance of the first definitive hematopoietic stem cells (HSCs). A mouse AGM-derived cell line, AGM-S3, was shown to support the development of HSCs. To elucidate the molecular mechanisms regulating early hematopoiesis, we obtained subclones from AGM-S3, one of which was hematopoiesis supportive (S3-A9) and the other one of which was non-supportive (S3-A7), and we analyzed their gene expression profiles by gene chip analysis. In the present study, we found that Glypican-1 (GPC1) was highly expressed in the supportive subclone AGM-S3-A9. Over-expression of GPC1 in non-supportive cells led to the proliferation of progenitor cells in human cord blood when cocultured with the transfected-stromal cells. Thus, GPC1 may have an important role in the establishment of a microenvironment that supports early events in hematopoiesis.

  16. Adenosine A(1), A(2a), A(2b), and A(3) receptors in hematopoiesis. 2. Expression of receptor mRNA in resting and lipopolysaccharide-activated mouse RAW 264.7 macrophages.

    PubMed

    Streitová, D; Hofer, M; Holá, J; Vacek, A; Pospísil, M

    2010-01-01

    Expression of mRNA for adenosine receptor subtypes A(1), A(2a), A(2b), and A(3) in normal and lipopolysaccharide (LPS)-activated murine RAW 264.7 macrophages has been investigated using the method of quantitative real-time polymerase chain reaction. The results have shown a very low, unquantifiable expression of adenosine A(1) receptor mRNA in both normal and LPS-activated macrophages. The other three adenosine receptor mRNAs have been found to be expressed at various but always quantifiable levels. Activation of the macrophages by LPS induced upregulation of the expression of adenosine receptor A(2a) and A(2b) mRNA, whereas the expression of adenosine receptor A(3) mRNA was downregulated. Unstimulated macrophages exhibited a high expression of the A(2b) adenosine receptor mRNA. The findings are discussed from the point of view of the antiinflammatory and hematopoiesis-stimulating roles of the adenosine receptor signaling. PMID:19249906

  17. Activated Leukocyte Cell Adhesion Molecule (ALCAM or CD166) Modulates Bone Phenotype and Hematopoiesis

    PubMed Central

    Hooker, R. Adam; Chitteti, Brahmananda R.; Egan, Patrick H.; Cheng, Ying-Hua; Himes, Evan R.; Meijome, Tomas; Srour, Edward F.; Fuchs, Robyn K.; Kacena, Melissa A.

    2015-01-01

    Activated Leukocyte Cell Adhesion Molecule (ALCAM/CD166), is expressed on osteoblasts (OB) and hematopoietic stem cells (HSC) residing in the hematopoietic niche, and may have important regulatory roles in bone formation. Because HSC numbers are reduced 77% in CD166−/− mice, we hypothesized that changes in bone phenotype and consequently the endosteal niche may partially be responsible for this alteration. Therefore, we investigated bone phenotype and OB function in CD166−/− mice. Although osteoclastic measures were not affected by loss of CD166, CD166−/− mice exhibited a modest increase in trabecular bone fraction (42%), and increases in osteoid deposition (72%), OB number (60%), and bone formation rate (152%). Cortical bone geometry was altered in CD166−/− mice resulting in up to 81% and 49% increases in stiffness and ultimate force, respectively. CD166−/− OB displayed elevated alkaline phosphatase (ALP) activity and mineralization, and increased mRNA expression of Fra 1, ALP, and osteocalcin. Overall, CD166−/− mice displayed modestly elevated trabecular bone volume fraction with increased OB numbers and deposition of osteoid, and increased OB differentiation in vitro, possibly suggesting more mature OB are secreting more osteoid. This may explain the decline in HSC number in vivo because immature OB are mainly responsible for hematopoiesis enhancing activity. PMID:25730656

  18. The Evolving Role of the Aryl Hydrocarbon Receptor (AHR) in the Normophysiology of Hematopoiesis

    PubMed Central

    Lindsey, Stephan; Papoutsakis, Eleftherios T.

    2012-01-01

    In addition to its role as a toxicological signal mediator, the Aryl Hydrocarbon Receptor (AHR) is also a transcription factor known to regulate cellular responses to oxidative stress and inflammation through transcriptional regulation of molecules involved in the signaling of nucear factor-erythroid 2-related factor-2 (Nrf2), p53 (TRP53), retinoblastoma (RB1), and NFκB. Recent research suggests that AHR activation of these signaling pathways may provide the molecular basis for understanding AHR’s evolving role in endogenous developmental functions during hematopoietic stem-cell maintenance and differentiation. Recent developments into the hematopoietic roles for AHR are reviewed, aiming to reconcile divergent findings as to the endogenous function of AHR in hematopoiesis. Potential mechanistic explanations for AHR’s involvement in hematopoietic differentiation are discussed, focusing on its known role as a cell cycle mediator and its interactions with Hypoxia-inducible transcription factor-1 alpha (HIF1-α). Understanding the physiological mechanisms of AHR activation and signaling have far reaching implications ranging from explaining the action of various toxicological agents to providing novel ways to expand stem cell populations ex vivo for use in transplant therapies. PMID:22628113

  19. 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. PMID:27139488

  20. Dose-dependent role of the cohesin complex in normal and malignant hematopoiesis

    PubMed Central

    Viny, Aaron D.; Ott, Christopher J.; Spitzer, Barbara; Rivas, Martin; Meydan, Cem; Papalexi, Efthymia; Yelin, Dana; Shank, Kaitlyn; Reyes, Jaime; Chiu, April; Romin, Yevgeniy; Boyko, Vitaly; Thota, Swapna; Maciejewski, Jaroslaw P.; Melnick, Ari

    2015-01-01

    Cohesin complex members have recently been identified as putative tumor suppressors in hematologic and epithelial malignancies. The cohesin complex guides chromosome segregation; however, cohesin mutant leukemias do not show genomic instability. We hypothesized that reduced cohesin function alters chromatin structure and disrupts cis-regulatory architecture of hematopoietic progenitors. We investigated the consequences of Smc3 deletion in normal and malignant hematopoiesis. Biallelic Smc3 loss induced bone marrow aplasia with premature sister chromatid separation and revealed an absolute requirement for cohesin in hematopoietic stem cell (HSC) function. In contrast, Smc3 haploinsufficiency increased self-renewal in vitro and in vivo, including competitive transplantation. Smc3 haploinsufficiency reduced coordinated transcriptional output, including reduced expression of transcription factors and other genes associated with lineage commitment. Smc3 haploinsufficiency cooperated with Flt3-ITD to induce acute leukemia in vivo, with potentiated Stat5 signaling and altered nucleolar topology. These data establish a dose dependency for cohesin in regulating chromatin structure and HSC function. PMID:26438361

  1. SUMOylation Regulates Growth Factor Independence 1 in Transcriptional Control and Hematopoiesis.

    PubMed

    Andrade, Daniel; Velinder, Matthew; Singer, Jason; Maese, Luke; Bareyan, Diana; Nguyen, Hong; Chandrasekharan, Mahesh B; Lucente, Helena; McClellan, David; Jones, David; Sharma, Sunil; Liu, Fang; Engel, Michael E

    2016-05-15

    Cell fate specification requires precise coordination of transcription factors and their regulators to achieve fidelity and flexibility in lineage allocation. The transcriptional repressor growth factor independence 1 (GFI1) is comprised of conserved Snail/Slug/Gfi1 (SNAG) and zinc finger motifs separated by a linker region poorly conserved with GFI1B, its closest homolog. Moreover, GFI1 and GFI1B coordinate distinct developmental fates in hematopoiesis, suggesting that their functional differences may derive from structures within their linkers. We show a binding interface between the GFI1 linker and the SP-RING domain of PIAS3, an E3-SUMO (small ubiquitin-related modifier) ligase. The PIAS3 binding region in GFI1 contains a conserved type I SUMOylation consensus element, centered on lysine-239 (K239). In silico prediction algorithms identify K239 as the only high-probability site for SUMO modification. We show that GFI1 is modified by SUMO at K239. SUMOylation-resistant derivatives of GFI1 fail to complement Gfi1 depletion phenotypes in zebrafish primitive erythropoiesis and granulocytic differentiation in cultured human cells. LSD1/CoREST recruitment and MYC repression by GFI1 are profoundly impaired for SUMOylation-resistant GFI1 derivatives, while enforced expression of MYC blocks granulocytic differentiation. These findings suggest that SUMOylation within the GFI1 linker favors LSD1/CoREST recruitment and MYC repression to govern hematopoietic differentiation. PMID:26951200

  2. Effects of combined sunitinib and extracranial stereotactic radiotherapy on bone marrow hematopoiesis

    PubMed Central

    Kao, Johnny; Timmins, Jonathan; Ozao-Choy, Junko; Packer, Stuart

    2016-01-01

    There is considerable interest in deploying stereotactic body radiotherapy in combination with immune therapy for patients with extracranial oligometastases. In addition to angiogenesis inhibition, sunitinib appears to mediate antitumor immunity through effects on circulating monocytic cells. The current study investigated the effects of combined sunitinib and stereotactic radiotherapy on hematopoiesis. As part of a phase I/II clinical trial utilizing concurrent sunitinib (25–50 mg on days 1–28) and image-guided radiation therapy (40–50 Gy in 10 fractions starting on days 8–19) for patients with metastatic cancer, the complete blood count, platelet count and automatic differential were performed pretreatment and on days 8 and 19. On average, sunitinib monotherapy for 7 days resulted in a 33% decrease in monocytes and an 18% decrease in neutrophils (P<0.01 for all). Compared to sunitinib alone, combined sunitinib and radiation resulted in a further decrease in neutrophils, lymphocytes and platelets (P<0.05). Following sunitinib and radiation treatment, a greater than average decrease in monocytes (≥200/µl) was associated with a significant increase in progression-free and overall survival times. This exploratory study provides further evidence that monocytes represent a potential biomarker in patients with solid tumors treated with sunitinib. PMID:27602153

  3. Parp-2 is required to maintain hematopoiesis following sublethal γ-irradiation in mice

    PubMed Central

    Farrés, Jordi; Martín-Caballero, Juan; Martínez, Carlos; Lozano, Juan J.; Llacuna, Laura; Ampurdanés, Coral; Ruiz-Herguido, Cristina; Dantzer, Françoise; Schreiber, Valérie; Villunger, Andreas; Bigas, Anna; Yélamos, José

    2016-01-01

    Hematopoietic stem cells self-renew for life to guarantee the continuous supply of all blood cell lineages. Here we show that Poly(ADP-ribose) polymerase-2 (Parp-2) plays an essential role in hematopoietic stem/progenitor cells (HSPC) survival under steady-state conditions and in response to stress. Increased levels of cell death were observed in HSPC from untreated Parp-2−/− mice, but this deficit was compensated by increased rates of self-renewal, associated with impaired reconstitution of hematopoiesis upon serial bone marrow transplantation. Cell death after γ-irradiation correlated with an impaired capacity to repair DNA damage in the absence of Parp-2. Upon exposure to sublethal doses of γ-irradiation, Parp-2−/− mice exhibited bone marrow failure that correlated with reduced long-term repopulation potential of irradiated Parp-2−/− HSPC under competitive conditions. In line with a protective role of Parp-2 against irradiation-induced apoptosis, loss of p53 or the pro-apoptotic BH3-only protein Puma restored survival of irradiated Parp-2−/− mice, whereas loss of Noxa had no such effect. Our results show that Parp-2 plays essential roles in the surveillance of genome integrity of HSPC by orchestrating DNA repair and restraining p53-induced and Puma-mediated apoptosis. The data may affect the design of drugs targeting Parp proteins and the improvement of radiotherapy-based therapeutic strategies. PMID:23678004

  4. Adenosine A(3) receptor agonist acts as a homeostatic regulator of bone marrow hematopoiesis.

    PubMed

    Hofer, Michal; Pospísil, Milan; Znojil, Vladimír; Holá, Jirina; Vacek, Antonín; Streitová, Denisa

    2007-07-01

    The present study was performed to define the optimum conditions of the stimulatory action of the adenosine A(3) receptor agonist, N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide (IB-MECA), on bone marrow hematopoiesis in mice. Effects of 2-day treatment with IB-MECA given at single doses of 200nmol/kg twice daily were investigated in normal mice and in mice whose femoral bone marrow cells were either depleted or regenerating after pretreatment with the cytotoxic drug 5-fluorouracil. Morphological criteria were used to determine the proliferation state of the granulocytic and erythroid cell systems. Significant negative correlation between the control proliferation state and the increase of cell proliferation after IB-MECA treatment irrespective of the cell lineage investigated was found. The results suggest the homeostatic character of the induced stimulatory effects and the need to respect the functional state of the target tissue when investigating effects of adenosine receptor agonists under in vivo conditions. PMID:17383145

  5. Mitotic History Reveals Distinct Stem Cell Populations and Their Contributions to Hematopoiesis

    PubMed Central

    Säwén, Petter; Lang, Stefan; Mandal, Pankaj; Rossi, Derrick J.; Soneji, Shamit; Bryder, David

    2016-01-01

    Summary Homeostasis of short-lived blood cells is dependent on rapid proliferation of immature precursors. Using a conditional histone 2B-mCherry-labeling mouse model, we characterize hematopoietic stem cell (HSC) and progenitor proliferation dynamics in steady state and following several types of induced stress. HSC proliferation following HSC transplantation into lethally irradiated mice is fundamentally different not only from native hematopoiesis but also from other stress contexts. Whereas transplantation promoted sustained, long-term proliferation of HSCs, both cytokine-induced mobilization and acute depletion of selected blood cell lineages elicited very limited recruitment of HSCs to the proliferative pool. By coupling mCherry-based analysis of proliferation history with multiplex gene expression analyses on single cells, we have found that HSCs can be stratified into four distinct subtypes. These subtypes have distinct molecular signatures and differ significantly in their reconstitution potentials, showcasing the power of tracking proliferation history when resolving functional heterogeneity of HSCs. PMID:26997272

  6. 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

  7. Cloning and expression analysis of murine phospholipase D1.

    PubMed Central

    Colley, W C; Altshuller, Y M; Sue-Ling, C K; Copeland, N G; Gilbert, D J; Jenkins, N A; Branch, K D; Tsirka, S E; Bollag, R J; Bollag, W B; Frohman, M A

    1997-01-01

    Activation of phosphatidylcholine-specific phospholipase D(PLD) occurs as part of the complex signal-transduction cascade initiated by agonist stimulation of tyrosine kinase and G-protein-coupled receptors. A variety of mammalian PLD activities have been described, and cDNAs for two PLDs recently reported (human PLD1 and murine PLD2). We describe here the cloning and chromosomal localization of murine PLD1. Northern-blot hybridization and RNase protection analyses were used to examine the expression of murine PLD1 and PLD2 ina variety of cell lines and tissues. PLD1 and PLD2 were expressed in all RNA samples examined, although the absolute expression of each isoform varied, as well as the ratio of PLD1 to PLD2. Moreover, in situ hybridization of adult brain and murine embryo sections revealed high levels of expression of individual PLDs in some cell types and no detectable expression in others. Thus the two PLDs probably carry out distinct roles in restricted subsets of cells rather than ubiquitous roles in all cells. PMID:9307024

  8. Analysis of murine HOXA-2 activity in Drosophila melanogaster.

    PubMed

    Percival-Smith, A; Bondy, J A

    1999-01-01

    The murine HOXA-2 protein shares amino acid sequence similarity with Drosophila Proboscipedia (PB). In this paper, we test whether HOXA-2 and PB are functionally equivalent in Drosophila. In Drosophila, PB inhibits SCR activity required for larval T1 beard formation and adult tarsus formation and is required for maxillary palp and proboscis formation. HOXA-2 expressed from a heat-shock promoter weakly suppressed SCR activity required for T1 beard formation. But interestingly neither PB nor HOXA-2 expressed from a heat-shock promoter suppressed murine HOXA-5 activity, the murine SCR homologue, from inducing ectopic T1 beards in T2 and T3, indicating that HOXA-5 does not interact with PB. HOXA-2 activity expressed from the Tubulin alpha 1 promoter modified the pb null phenotype resulting in a proboscis-to-arista transformation, indicating that HOXA-2 was able to suppress SCR activity required for tarsus formation. However, HOXA-2 expressed from a Tubulin alpha 1 promoter was unable to direct maxillary palp determination when either ectopically expressed in the antenna or in the maxillary palp primordia of a pb null mutant. HOXA-2 was also unable to rescue pseudotrachea formation in a pb null mutant. These results indicate that the only activity that PB and HOXA-2 weakly share is the inhibition of SCR activity, and that murine HOXA-5 and Drosophila SCR do not share inhibition by PB activity. PMID:10322642

  9. Conserved hemopoietic transcription factor Cg-SCL delineates hematopoiesis of Pacific oyster Crassostrea gigas.

    PubMed

    Song, Xiaorui; Wang, Hao; Chen, Hao; Sun, Mingzhe; Liang, Zhongxiu; Wang, Lingling; Song, Linsheng

    2016-04-01

    Hemocytes are the effective immunocytes in bivalves, which have been reported to be derived from stem-like cells in gill epithelium of oyster. In the present work, a conserved haematopoietic transcription factor Tal-1/Scl (Stem Cell Leukemia) was identified in Pacific oyster (Cg-SCL), and it was evolutionarily close to the orthologs in deuterostomes. Cg-SCL was highly distributed in the hemocytes as well as gill and mantle. The hemocyte specific genes Integrin, EcSOD and haematopoietic transcription factors GATA3, C-Myb, c-kit, were down-regulated when Cg-SCL was interfered by dsRNA. During the larval developmental stages, the mRNA transcripts of Cg-SCL gradually increased after fertilization and peaked at early trochophore larvae stage (10 hpf, hours post fertilization), then sharply decreased in late trochophore larvae stage (15 hpf) before resuming in umbo larvae (120 hpf). Whole-mount immunofluorescence assay further revealed that the immunoreactivity of Cg-SCL appeared in blastula larvae with two approximate symmetric spots, and this expression pattern lasted in gastrula larvae. By trochophore, the immunoreactivity formed a ring around the dorsal region and then separated into two remarkable spots at the dorsal side in D-veliger larvae. After bacterial challenge, the mRNA expression levels of Cg-SCL were significantly up-regulated in the D-veliger and umbo larvae, indicating the available hematopoietic regulation in oyster larvae. These results demonstrated that Cg-SCL could be used as haematopoietic specific marker to trace potential developmental events of hematopoiesis during ontogenesis of oyster, which occurred early in blastula stage and maintained until D-veliger larvae. PMID:26915307

  10. AML suppresses hematopoiesis by releasing exosomes that contain microRNAs targeting c-MYB.

    PubMed

    Hornick, Noah I; Doron, Ben; Abdelhamed, Sherif; Huan, Jianya; Harrington, Christina A; Shen, Rongkun; Cambronne, Xiaolu A; Chakkaramakkil Verghese, Santhosh; Kurre, Peter

    2016-01-01

    Exosomes are paracrine regulators of the tumor microenvironment and contain complex cargo. We previously reported that exosomes released from acute myeloid leukemia (AML) cells can suppress residual hematopoietic stem and progenitor cell (HSPC) function indirectly through stromal reprogramming of niche retention factors. We found that the systemic loss of hematopoietic function is also in part a consequence of AML exosome-directed microRNA (miRNA) trafficking to HSPCs. Exosomes isolated from cultured AML or the plasma from mice bearing AML xenografts exhibited enrichment of miR-150 and miR-155. HSPCs cocultured with either of these exosomes exhibited impaired clonogenicity, through the miR-150- and miR-155-mediated suppression of the translation of transcripts encoding c-MYB, a transcription factor involved in HSPC differentiation and proliferation. To discover additional miRNA targets, we captured miR-155 and its target transcripts by coimmunoprecipitation with an attenuated RNA-induced silencing complex (RISC)-trap, followed by high-throughput sequencing. This approach identified known and previously unknown miR-155 target transcripts. Integration of the miR-155 targets with information from the protein interaction database STRING revealed proteins indirectly affected by AML exosome-derived miRNA. Our findings indicate a direct effect of AML exosomes on HSPCs that, through a stroma-independent mechanism, compromises hematopoiesis. Furthermore, combining miRNA target data with protein-protein interaction data may be a broadly applicable strategy to define the effects of exosome-mediated trafficking of regulatory molecules within the tumor microenvironment. PMID:27601730

  11. MDS-associated somatic mutations and clonal hematopoiesis are common in idiopathic cytopenias of undetermined significance

    PubMed Central

    Kwok, Brian; Hall, Jeff M.; Witte, John S.; Xu, Yin; Reddy, Prashanti; Lin, Keming; Flamholz, Rachel; Dabbas, Bashar; Yung, Aine; Al-Hafidh, Jenan; Balmert, Emily; Vaupel, Christine; El Hader, Carlos; McGinniss, Matthew J.; Nahas, Shareef A.; Kines, Julie

    2015-01-01

    Establishing a diagnosis in patients suspected of having a myelodysplastic syndrome (MDS) can be challenging and could be informed by the identification of somatic mutations. We performed a prospective study to examine the frequency and types of mutations encountered in 144 patients with unexplained cytopenias. Based on bone marrow findings, 17% were diagnosed with MDS, 15% with idiopathic cytopenias of undetermined significance (ICUS) and some evidence of dysplasia, and 69% with ICUS and no dysplasia. Bone marrow DNA was sequenced for mutations in 22 frequently mutated myeloid malignancy genes. Somatic mutations were identified in 71% of MDS patients, 62% of patients with ICUS and some dysplasia, and 20% of ICUS patients and no dysplasia. In total, 35% of ICUS patients carried a somatic mutation or chromosomal abnormality indicative of clonal hematopoiesis. We validated these results in a cohort of 91 lower-risk MDS and 249 ICUS cases identified over a 6-month interval. Mutations were found in 79% of those with MDS, in 45% of those with ICUS with dysplasia, and in 17% of those with ICUS without dysplasia. The spectrum of mutated genes was similar with the exception of SF3B1 which was rarely mutated in patients without dysplasia. Variant allele fractions were comparable between clonal ICUS (CCUS) and MDS as were mean age and blood counts. We demonstrate that CCUS is a more frequent diagnosis than MDS in cytopenic patients. Clinical and mutational features are similar in these groups and may have diagnostic utility once outcomes in CCUS patients are better understood. PMID:26429975

  12. CXCL12 Influences the Development of Extramedullary Hematopoiesis in the Spleens of Myelofibrosis Patients

    PubMed Central

    Wang, Xiaoli; Cho, Sool Yeon; Hu, Cing Siang; Chen, Daniel; Roboz, John; Hoffman, Ronald

    2014-01-01

    Myelofibrosis (MF) is characterized by the constitutive mobilization of hematopoietic stem cells (HSC) and progenitor cells (HPC) and the establishment of extramedullary hematopoiesis (EMH). The mechanisms underlying this abnormal HSC/HPC trafficking pattern remain poorly understood. We demonstrated that both splenic and peripheral blood (PB) MF CD34+ cells equally share a defective ability to home to the marrow but not the spleens of NOD/SCID mice. This trafficking pattern could not be attributed to discordant expression of integrins or chemokine receptors other than the down-regulation of CXCR4 by both PB and splenic MF CD34+ cells. The number of both splenic MF CD34+ cells and HPCs that migrated towards splenic MF plasma was, however, significantly greater than the number that migrated towards PB MF plasma. The concentration of the intact HSC/HPC chemo-attractant, CXCL12, was greater in splenic MF plasma than PB MF plasma as quantified using mass spectrometry. Functionally inactive truncated products of CXCL12 which are the product of proteolytic degradation by serine proteases were detected at similar levels in both splenic and PB MF plasma. Treatment with an anti-CXCL12 neutralizing antibody resulted in a reduction in the degree of migration of splenic MF CD34+ cells towards both PB and splenic MF plasma validating the role of CXCL12 as a functional chemo-attractant. Our data indicate that the MF splenic microenvironment is characterized by increased levels of intact, functional CXCL12, which contributes to the localization of MF CD34+ cells to the spleen and the establishment of EMH. PMID:25461253

  13. Tissue Inhibitor of Metalloproteinase-3 (TIMP-3) Regulates Hematopoiesis and Bone Formation In Vivo

    PubMed Central

    Shen, Yi; Winkler, Ingrid G.; Barbier, Valerie; Sims, Natalie A.; Hendy, Jean; Lévesque, Jean-Pierre

    2010-01-01

    Background Tissue inhibitor of metalloproteinases-3 (TIMP-3) inhibits matrix metalloproteinases and membrane-bound sheddases. TIMP-3 is associated with the extracellular matrix and is expressed in highly remodeling tissues. TIMP-3 function in the hematopoietic system is unknown. Methodology/Principal Findings We now report that TIMP-3 is highly expressed in the endosteal region of the bone marrow (BM), particularly by osteoblasts, endothelial and multipotent mesenchymal stromal cells which are all important cellular components of hematopoietic stem cell (HSC) niches, whereas its expression is very low in mature leukocytes and hematopoietic stem and progenitor cells. A possible role of TIMP-3 as an important niche component was further suggested by its down-regulation during granulocyte colony-stimulating factor-induced mobilization. To further investigate TIMP-3 function, mouse HSC were retrovirally transduced with human TIMP-3 and transplanted into lethally irradiated recipients. TIMP-3 overexpression resulted in decreased frequency of B and T lymphocytes and increased frequency of myeloid cells in blood and BM, increased Lineage-negative Sca-1+KIT+ cell proliferation in vivo and in vitro and increased colony-forming cell trafficking to blood and spleen. Finally, over-expression of human TIMP-3 caused a late onset fatal osteosclerosis. Conclusions/Significance Our results suggest that TIMP-3 regulates HSC proliferation, differentiation and trafficking in vivo, as well as bone and bone turn-over, and that TIMP-3 is expressed by stromal cells forming HSC niches within the BM. Thus, TIMP-3 may be an important HSC niche component regulating both hematopoiesis and bone remodeling. PMID:20941363

  14. Murine typhus in travelers returning from Indonesia.

    PubMed Central

    Parola, P.; Vogelaers, D.; Roure, C.; Janbon, F.; Raoult, D.

    1998-01-01

    We report the first three documented cases of murine typhus imported into Europe from Indonesia, discuss clues for the diagnosis of the disease, and urge that murine fever be considered in the diagnosis of febrile disease in travelers. PMID:9866749

  15. Antibacterial activity of recombinant murine beta interferon.

    PubMed Central

    Fujiki, T; Tanaka, A

    1988-01-01

    Recombinant murine beta interferon was protective and therapeutic for mice against Listeria monocytogenes infection in vivo. The recombinant murine beta interferon caused enhanced H2O2 release by macrophages in vivo, but not in vitro. PMID:3343048

  16. Human cord cell hematopoiesis in three-dimensional nonwoven fibrous matrices: in vitro simulation of the marrow microenvironment.

    PubMed

    Li, Y; Ma, T; Kniss, D A; Yang, S T; Lasky, L C

    2001-06-01

    Current hematopoietic culture systems mainly utilize two-dimensional devices with limited ability to promote self-renewal of early progenitors. In vivo-like three-dimensional (3-D) culture environments might be conducive to regulating stem cell proliferation and differentiation similar to in vivo hematopoiesis. The few 3-D cultures reported in the literature either produced few progenitors or provided little information about microenvironment. In this study, we constructed a 3-D hematopoietic microenvironment composed of nonwoven matrix and human cord blood (CB) cells to simulate the marrow microenvironment and expand cord progenitors. Nonwoven polyethylene terephthalate (PET) fabric with defined microstructure was used as the 3-D scaffold and the PET surface was modified by hydrolysis to improve cell adhesion. Different cell organizations were formed in a 3-D matrix in a developmental manner, from individual cells and cells bridging between fibers to large cell aggregates. Both stromal and hematopoietic cells were distributed spatially within the scaffold. Compared to two-dimensional (2-D) CD34(+) cell culture, 3-D culture produced 30-100% higher total cells and progenitors without exogenous cytokines. With thrombopoietin and flt-3/flk-2 ligand, it supported two- to three-fold higher total cell number (62.1- vs. 24.6-fold), CD34(+) cell number (6.8- vs. 2.8-fold) and colony-forming unit (CFU) number for 7-9 weeks (n = 6), indicating a hematopoiesis pathway that promoted progenitor production. Culture in 3-D nonwoven matrices enhanced cell-cell and cell-matrix interactions and allowed 3-D distribution of stromal and hematopoietic cells. The formation of cell aggregates and higher progenitor content indicated that the spatial microenvironment in 3-D culture played an important role in promoting hematopoiesis. This 3-D culture system can be used as an in vitro model to study stem cell or progenitor behavior, and to achieve sustained progenitor expansion. PMID

  17. Type I IFNs Act upon Hematopoietic Progenitors To Protect and Maintain Hematopoiesis during Pneumocystis Lung Infection in Mice.

    PubMed

    Prigge, Justin R; Hoyt, Teri R; Dobrinen, Erin; Capecchi, Mario R; Schmidt, Edward E; Meissner, Nicole

    2015-12-01

    Although acquired bone marrow failure (BMF) is considered a T cell-mediated autoimmune disease, few studies have considered contributing roles of innate immune deviations following otherwise innocuous infections as a cause underlying the immune defects that lead to BMF. Type I IFN signaling plays an important role in protecting hematopoiesis during systemic stress responses to the opportunistic fungal pathogen Pneumocystis. During Pneumocystis lung infection, mice deficient in both lymphocytes and type I IFN receptor (IFrag(-/-)) develop rapidly progressing BMF associated with accelerated hematopoietic cell apoptosis. However, the communication pathway eliciting the induction of BMF in response to this strictly pulmonary infection has been unclear. We developed a conditional-null allele of Ifnar1 and used tissue-specific induction of the IFrag(-/-) state and found that, following Pneumocystis lung infection, type I IFNs act not only in the lung to prevent systemic immune deviations, but also within the progenitor compartment of the bone marrow to protect hematopoiesis. In addition, transfer of sterile-filtered serum from Pneumocystis-infected mice as well as i.p. injection of Pneumocystis into uninfected IFrag(-/-) mice induced BMF. Although specific cytokine deviations contribute to induction of BMF, immune-suppressive treatment of infected IFrag(-/-) mice ameliorated its progression but did not prevent loss of hematopoietic progenitor functions. This suggested that additional, noncytokine factors also target and impair progenitor functions; and interestingly, fungal β-glucans were also detected in serum. In conclusion, our data demonstrate that type 1 IFN signaling protects hematopoiesis within the bone marrow compartment from the damaging effects of proinflammatory cytokines elicited by Pneumocystis in the lung and possibly at extrapulmonary sites via circulating fungal components. PMID:26519535

  18. Targeted Disruption of the Murine fps/fes Proto-Oncogene Reveals that Fps/Fes Kinase Activity Is Dispensable for Hematopoiesis

    PubMed Central

    Senis, Yotis; Zirngibl, Ralph; McVeigh, Jennifer; Haman, Andre; Hoang, Trang; Greer, Peter A.

    1999-01-01

    The fps/fes proto-oncogene encodes a cytoplasmic protein-tyrosine kinase that is functionally implicated in the survival and terminal differentiation of myeloid progenitors and in signaling from several members of the cytokine receptor superfamily. To gain further insight into the physiological function of fps/fes, we targeted the mouse locus with a kinase-inactivating missense mutation. Mutant Fps/Fes protein was expressed at normal levels in these mice, but it lacked detectable kinase activity. Homozygous mutant animals were viable and fertile, and they showed no obvious defects. Flow cytometry analysis of bone marrow showed no statistically significant differences in the levels of myeloid, erythroid, or B-cell precursors. Subtle abnormalities observed in mutant mice included slightly elevated total leukocyte counts and splenomegaly. In bone marrow hematopoietic progenitor cell colony-forming assays, mutant mice gave slightly elevated numbers and variable sizes of CFU-granulocyte macrophage in response to interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Tyrosine phosphorylation of Stat3 and Stat5A in bone marrow-derived macrophages was dramatically reduced in response to GM-CSF but not to IL-3 or IL-6. This suggests a distinct nonredundant role for Fps/Fes in signaling from the GM-CSF receptor that does not extend to the closely related IL-3 receptor. Lipopolysaccharide-induced Erk1/2 activation was also reduced in mutant macrophages. These subtle molecular phenotypes suggest a possible nonredundant role for Fps/Fes in myelopoiesis and immune responses. PMID:10523632

  19. Immunosuppressive effect of murine cytomegalovirus.

    PubMed Central

    Loh, L; Hudson, J B

    1980-01-01

    Murine cytomegalovirus suppressed the ability of spleen cells to respond to mitogens in vitro. The degree of suppression was proportional to the multiplicity of infection. This effect could not be explained by cytolysis of lymphocytes, an alteration in the kinetics of the response to mitogen, or a direct competition between virions and mitogen molecules for cell-surface receptors. Nor was it due to simple contact between cell and virus, since ultraviolet-inactivated murine cytomegalovirus failed to suppress the response to mitogens. Reconstitution experiments were performed which involved mixing various combinations of infected and uninfected macrophages and lymphocytes. Under these conditions, it was found that the infected macrophages and lymphocytes. Under these conditions, it was found that the infected macrophages had an impaired capacity to mediate the response ot T lymphocytes to concanavalin A. This suggests that murine cytomegalovirus may cause immunosuppression indirectly by interfering with macrophage function. PMID:6244228

  20. Differential expression and functional role of GATA-2, NF-E2, and GATA-1 in normal adult hematopoiesis.

    PubMed Central

    Labbaye, C; Valtieri, M; Barberi, T; Meccia, E; Masella, B; Pelosi, E; Condorelli, G L; Testa, U; Peschle, C

    1995-01-01

    We have explored the expression of the transcription factors GATA-1, GATA-2, and NF-E2 in purified early hematopoietic progenitor cells (HPCs) induced to gradual unilineage erythroid or granulocytic differentiation by growth factor stimulus. GATA-2 mRNA and protein, already expressed in quiescent HPCs, is rapidly induced as early as 3 h after growth factor stimulus, but then declines in advanced erythroid and granulocytic differentiation and maturation. NF-E2 and GATA-1 mRNAs and proteins, though not detected in quiescent HPCs, are gradually induced at 24-48 h in both erythroid and granulocytic culture. Beginning at late differentiation/early maturation stage, both transcription factors are further accumulated in the erythroid pathway, whereas they are suppressed in the granulopoietic series. Similarly, the erythropoietin receptor (EpR) is induced and sustainedly expressed during erythroid differentiation, although beginning at later times (i.e., day 5), whereas it is barely expressed in the granulopoietic pathway. In the first series of functional studies, HPCs were treated with antisense oligomers targeted to transcription factor mRNA: inhibition of GATA-2 expression caused a decreased number of both erythroid and granulocyte-monocytic clones, whereas inhibition of NF-E2 or GATA-1 expression induced a selective impairment of erythroid colony formation. In a second series of functional studies, HPCs treated with retinoic acid were induced to shift from erythroid to granulocytic differentiation (Labbaye et al. 1994. Blood. 83:651-656); this was coupled with abrogation of GATA-1, NF-E2, and EpR expression and conversely enhanced GATA-2 levels. These results indicate the expression and key role of GATA-2 in the early stages of HPC proliferation/differentiation. Conversely, NF-E2 and GATA-1 expression and function are apparently restricted to erythroid differentiation and maturation: their expression precedes that of the EpR, and their function may be in part mediated via the EpR. Images PMID:7738198

  1. Extramedullary Hematopoiesis Generates Ly-6Chigh Monocytes that Infiltrate Atherosclerotic Lesions

    PubMed Central

    Robbins, Clinton S.; Chudnovskiy, Aleksey; Rauch, Philipp J.; Figueiredo, Jose-Luiz; Iwamoto, Yoshiko; Gorbatov, Rostic; Etzrodt, Martin; Weber, Georg F.; Ueno, Takuya; van Rooijen, Nico; Mulligan-Kehoe, Mary Jo; Libby, Peter; Nahrendorf, Matthias; Pittet, Mikael J.; Weissleder, Ralph; Swirski, Filip K.

    2012-01-01

    Background Atherosclerotic lesions are believed to grow via the recruitment of bone marrow-derived monocytes. Among the known murine monocyte subsets, Ly-6Chigh monocytes are inflammatory, accumulate in lesions preferentially, and differentiate. Here we hypothesized that the bone marrow outsources the production of Ly-6Chigh monocytes during atherosclerosis. Methods and Results Using murine models of atherosclerosis and fate-mapping approaches, we show that hematopoietic stem and progenitor cells (HSPC) progressively relocate from the bone marrow to the splenic red pulp where they encounter GM-CSF and IL-3, clonally expand, and differentiate to Ly-6Chigh monocytes. Monocytes born in such extramedullary niches intravasate, circulate, and accumulate abundantly in atheromata. Upon lesional infiltration, Ly-6Chigh monocytes secrete inflammatory cytokines, reactive oxygen species, and proteases. Eventually, they ingest lipids and become foam cells. Conclusions Our findings indicate that extramedullary sites supplement the bone marrow’s hematopoietic function by producing circulating inflammatory cells that infiltrate atherosclerotic lesions. PMID:22144566

  2. Functional consequences of perturbed CXCL12 signal processing: analyses of immature hematopoiesis in GRK6-deficient mice.

    PubMed

    Chudziak, Doreen; Spohn, Gabriele; Karpova, Darja; Dauber, Katrin; Wiercinska, Eliza; Miettinen, Johanna A; Papayannopoulou, Thalia; Bönig, Halvard

    2015-03-15

    Hematopoietic stem and progenitor cells (HSPCs) reside in bone marrow (BM) in an environment rich in CXCL12, the ligand for CXCR4, which is constitutively expressed on all immature hematopoietic cells in BM. This ligand-receptor pair critically controls HSPC retention and (relative) quiescence in BM. Interestingly, in a chemokine-abundant environment, CXCR4 surface expression and CXCL12 sensitivity of BM-residing HSPCs are continuously maintained. The mechanisms underlying this peculiar pattern of G-protein signal integration by BM-HSPCs are unknown. G-protein receptor kinases (GRKs) control receptor function by phosphorylating the intracellular domains upon ligand-induced activation, which results in receptor internalization and transient refractoriness. Using, therefore, a GRK6-deficient (GRK6(-/-)) mouse, we sought to address how perturbed ligand-induced CXCR4 (in)activation affects HSPC behavior in vitro and in vivo. In vitro, GRK6(-/-) HSPCs were characterized by hyper-responsiveness to CXCL12, as expected. In vivo, GRK6(-/-) immature hematopoiesis was characterized by a marked expansion of immature hematopoiesis in spleens and a modest repopulation defect in serial competitive transplantation. Enforced mobilization with granulocyte colony-stimulating factor (G-CSF) and AMD3100 was normal, as was hematopoietic regeneration after noncompetitive transplantation or pharmacological myelosuppression. These observations illustrate that GRK-mediated restriction of CXCR4 signal input after ligand engagement is largely dispensable for BM-resident HSPCs, which may explain how continuous CXCL12 responsiveness of BM-HSPCs can be maintained. PMID:25316534

  3. Antimicrobial proteins of murine macrophages.

    PubMed Central

    Hiemstra, P S; Eisenhauer, P B; Harwig, S S; van den Barselaar, M T; van Furth, R; Lehrer, R I

    1993-01-01

    Three murine microbicidal proteins (MUMPs) were purified from cells of the murine macrophage cell line RAW264.7 that had been activated by gamma interferon. Similar proteins were also present in nonactivated RAW264.7 cells, in cells of the murine macrophage cell line J774A.1, and in resident and activated murine peritoneal macrophages. MUMP-1, MUMP-2, and MUMP-3 killed Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Mycobacterium fortuitum, and Cryptococcus neoformans in vitro. MUMP-1 resembled an H1 histone but was unusual because its N-terminal residue (serine) was not N acetylated. Although MUMP-2 was N terminally blocked, its high lysine/arginine ratio and its reactivity with an antibody to H1 histones suggested that it also belonged to the H1 histone family. MUMP-3 was identical to histone H2B in 30 of 30 amino-terminal residues. Although the antimicrobial properties of histones have been recognized for decades, this is the first evidence that such proteins may endow the lysosomal apparatus of macrophages with nonoxidative antimicrobial potential. Other MUMPs, including some with a more restricted antimicrobial spectrum and one that appeared to be induced in RAW264.7 cells after gamma interferon stimulation, were noted but remain to be characterized. Images PMID:8514411

  4. The role of G-CSF and IL-6 in the granulopoiesis-stimulating activity of murine blood serum induced by perorally administered ultrafiltered pig leukocyte extract, IMUNOR.

    PubMed

    Vacek, Antonín; Hofer, Michal; Holá, Jirina; Weiterová, Lenka; Streitová, Denisa; Svoboda, Jaroslav

    2007-05-01

    IMUNOR, a low-molecular weight (< 12 kD) ultrafiltered pig leukocyte extract, has been previously found to have significant stimulatory effects on murine hematopoiesis supressed by ionizing radiation or cytotoxic drugs. This communication shows data on the mechanisms of these effects. Using ELISA assay, significantly increased levels of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) were observed. On the contrary, no detectable levels of granulocyte-macrophage colony-stimulating factor (GM-CFC) and interleukin-3 (IL-3) have been found in blood serum of IMUNOR-treated mice. Incubation of the serum from IMUNOR-treated mice with antibodies against G-CSF caused abrogation of the ability of the sera to stimulate in vitro growth of colonies originating from granulocyte-macrophage progenitor cells (GM-CFC). In contrast, incubation of the serum with antibodies against IL-6 did not change its colony-stimulating activity. It may be inferred from these findings that G-CSF is probably the main cytokine responsible for the granulopoiesis-stimulating effects of IMUNOR. When the serum from IMUNOR-treated mice with G-CSF inactivated by anti-G-CSF antibodies (but with elevated IL-6) was added to cultures of bone marrow cells together with a suboptimum concentration of IL-3, a significant increase in the numbers of GM-CFC colonies was found. Moreover, conjoint inactivation of G-CSF and IL-6 significantly decreased the numbers of GM-CFC colonies in comparison with those observed when only G-CSF was inactivated. This observation strongly suggests that though IMUNOR-induced IL-6 is not able to induce the growth of GM-CFC colonies alone, it is able to potentiate the hematopoiesis-stimulating effect of IL-3. These findings represent a new knowledge concerning the hematopoiesis-stimulating action of IMUNOR, a promising immunomodulatory agent. PMID:17386413

  5. The proteasome inhibitor bortezomib induces testicular toxicity by upregulation of oxidative stress, AMP-activated protein kinase (AMPK) activation and deregulation of germ cell development in adult murine testis

    SciTech Connect

    Li, Wei; Fu, Jianfang; Zhang, Shun; Zhao, Jie; Xie, Nianlin; Cai, Guoqing

    2015-06-01

    Understanding how chemotherapeutic agents mediate testicular toxicity is crucial in light of compelling evidence that male infertility, one of the severe late side effects of intensive cancer treatment, occurs more often than they are expected to. Previous study demonstrated that bortezomib (BTZ), a 26S proteasome inhibitor used to treat refractory multiple myeloma (MM), exerts deleterious impacts on spermatogenesis in pubertal mice via unknown mechanisms. Here, we showed that intermittent treatment with BTZ resulted in fertility impairment in adult mice, evidenced by testicular atrophy, desquamation of immature germ cells and reduced caudal sperm storage. These deleterious effects may originate from the elevated apoptosis in distinct germ cells during the acute phase and the subsequent disruption of Sertoli–germ cell anchoring junctions (AJs) during the late recovery. Mechanistically, balance between AMP-activated protein kinase (AMPK) activation and Akt/ERK pathway appeared to be indispensable for AJ integrity during the late testicular recovery. Of particular interest, the upregulated testicular apoptosis and the following disturbance of Sertoli–germ cell interaction may both stem from the excessive oxidative stress elicited by BTZ exposure. We also provided the in vitro evidence that AMPK-dependent mechanisms counteract follicle-stimulating hormone (FSH) proliferative effects in BTZ-exposed Sertoli cells. Collectively, BTZ appeared to efficiently prevent germ cells from normal development via multiple mechanisms in adult mice. Employment of antioxidants and/or AMPK inhibitor may represent an attractive strategy of fertility preservation in male MM patients exposed to conventional BTZ therapy and warrants further investigation. - Highlights: • Intermittent treatment with BTZ caused fertility impairment in adult mice. • BTZ treatment elicited apoptosis during early phase of testicular recovery. • Up-regulation of oxidative stress by BTZ treatment

  6. The proteasome inhibitor bortezomib induces testicular toxicity by upregulation of oxidative stress, AMP-activated protein kinase (AMPK) activation and deregulation of germ cell development in adult murine testis.

    PubMed

    Li, Wei; Fu, Jianfang; Zhang, Shun; Zhao, Jie; Xie, Nianlin; Cai, Guoqing

    2015-06-01

    Understanding how chemotherapeutic agents mediate testicular toxicity is crucial in light of compelling evidence that male infertility, one of the severe late side effects of intensive cancer treatment, occurs more often than they are expected to. Previous study demonstrated that bortezomib (BTZ), a 26S proteasome inhibitor used to treat refractory multiple myeloma (MM), exerts deleterious impacts on spermatogenesis in pubertal mice via unknown mechanisms. Here, we showed that intermittent treatment with BTZ resulted in fertility impairment in adult mice, evidenced by testicular atrophy, desquamation of immature germ cells and reduced caudal sperm storage. These deleterious effects may originate from the elevated apoptosis in distinct germ cells during the acute phase and the subsequent disruption of Sertoli-germ cell anchoring junctions (AJs) during the late recovery. Mechanistically, balance between AMP-activated protein kinase (AMPK) activation and Akt/ERK pathway appeared to be indispensable for AJ integrity during the late testicular recovery. Of particular interest, the upregulated testicular apoptosis and the following disturbance of Sertoli-germ cell interaction may both stem from the excessive oxidative stress elicited by BTZ exposure. We also provided the in vitro evidence that AMPK-dependent mechanisms counteract follicle-stimulating hormone (FSH) proliferative effects in BTZ-exposed Sertoli cells. Collectively, BTZ appeared to efficiently prevent germ cells from normal development via multiple mechanisms in adult mice. Employment of antioxidants and/or AMPK inhibitor may represent an attractive strategy of fertility preservation in male MM patients exposed to conventional BTZ therapy and warrants further investigation. PMID:25886977

  7. A Novel Population of Cells Expressing Both Hematopoietic and Mesenchymal Markers Is Present in the Normal Adult Bone Marrow and Is Augmented in a Murine Model of Marrow Fibrosis

    PubMed Central

    Ohishi, Masanobu; Ono, Wanida; Ono, Noriaki; Khatri, Richa; Marzia, Marilena; Baker, Emma K.; Root, Sierra H.; Wilson, Tremika Le-Shan; Iwamoto, Yukihide; Kronenberg, Henry M.; Aguila, Hector L.; Purton, Louise E.; Schipani, Ernestina

    2012-01-01

    Bone marrow (BM) fibrosis is a feature of severe hyperparathyroidism. Consistent with this observation, mice expressing constitutively active parathyroid hormone (PTH)/PTH-related peptide receptors (PPR) in osteoblasts (PPR*Tg) display BM fibrosis. To obtain insight into the nature of BM fibrosis in such a model, a double-mutant mouse expressing constitutively active PPR and green fluorescent protein (GFP) under the control of the type I collagen promoter (PPR*Tg/GFP) was generated. Confocal microscopy and flow cytometry revealed the presence of a cell population expressing GFP (GFP+) that was also positive for the hematopoietic marker CD45 in the BM of both PPR*Tg/GFP and control animals. This cell population was expanded in PPR*Tg/GFP. The existence of cells expressing both type I collagen and CD45 in the adult BM was confirmed by IHC and fluorescence-activated cell sorting. An analysis of total RNA extracted from sorted GFP+CD45+ cells showed that these cells produced type I collagen and PTH/PTH-related peptide receptor and receptor activator for NF-κB mRNAs, further supporting their features of being both mesenchymal and hematopoietic lineages. Similar cells, known as fibrocytes, are also present in pathological fibroses. Our findings, thus, indicate that the BM is a permissive microenvironment for the differentiation of fibrocyte-like cells and raise the possibility that these cells could contribute to the pathogenesis of BM fibrosis. PMID:22155108

  8. Focal extra-axial hemorrahagic mass with subdural hemorrhage secondare to extramedullary hematopoiesis in idiopathic myelodysplastic sindrome.

    PubMed

    Di Ieva, A; Di Lieva, A; Aimar, E; Tancioni, F; Levi, D; Debernardi, A; Pisano, P; Rahal, D; Nozza, A; Magagnoli, M; Gaetani, P

    2007-03-01

    Idiopathic myelodysplastic syndrome is a disease characterized by a clonal stem cell disorder in which megacaryocitic and granulocytic lineages are mainly involved; extramedullary myeloid metaplasia is due to abnormal location of myeloid tissue in other organs than bone marrow. Rarely the central nervous system is involved. When it happens, it is typical to find masses around the brain and pachymeningeal thickening, but it is very rare to find it associated with subdural haemorrhage, as in the case we describe in the present article. Considering our case and the literature we can suggest that radiological images associated with the clinical history of the patient suggestive for extramedullary hematopoiesis can be sufficient for a correct diagnosis and for a radiotherapy treatment, demanding surgery in the case of diagnostic doubts, massive hemorrahages or neurological decifits caused by the focal lesions. PMID:17369789

  9. Acute arrest of hematopoiesis induced by infection with Staphylococcus epidermidis following total knee arthroplasty: A case report and literature review

    PubMed Central

    BI, LINTAO; LI, JUN; LU, ZHENXIA; SHAO, HUI; WANG, YING

    2016-01-01

    Infection is one of the most severe complications of total knee prosthesis implantation. The present study reported the case of a 74-year-old female that developed a Staphylococcus epidermidis infection following a cemented total knee arthroplasty. A routine blood test revealed neutropenia and anemia, while S. epidermidis was detected in the peripheral blood and bone marrow. In the present case, S. epidermidis infection led to acute arrest of hematopoiesis (AAH), also known as aplastic crisis, which is the temporary cessation of red cell production. The development of AAH secondary to S. epidermidis infection is rare and, to the best of our knowledge, this is the first case reported in the literature. The present study increased our knowledge of this rare disease and its characteristics, which will enable physicians to be aware of the development of AAH as a rare complication of S. epidermidis infection. PMID:26998019

  10. Concise Review: CXCR4/CXCL12 Signaling in Immature Hematopoiesis--Lessons From Pharmacological and Genetic Models.

    PubMed

    Karpova, Darja; Bonig, Halvard

    2015-08-01

    Dominant, although nonexclusive roles of CXCR4 and its chief ligand CXCL12 in bone marrow (BM) retention and preservation of the relative quiescence of hematopoietic stem/progenitor cells (HSPCs), along with their involvement in human immunodeficiency virus infection, in trafficking of mature hematopoietic cells to sites of inflammation and in orderly migration of nonhematopoietic cells during embryogenesis, explain the significant interest of the scientific community in the mode of action of this receptor-ligand pair. In this focused review, we seek to distil from the large body of information that has become available over the years some of the key findings about the role of CXCR4/CXCL12 in normal immature hematopoiesis. It is hoped that understanding the mechanistic insights gained there from will help generate hypotheses about potential avenues in which cancer/leukemia cell behavior can be modified by interference with this pathway. PMID:25966814

  11. Blood morphology and the levels of selected cytokines related to hematopoiesis in occupational short-term exposure to lead.

    PubMed

    Dobrakowski, Michał; Boroń, Marta; Czuba, Zenon P; Birkner, Ewa; Chwalba, Artur; Hudziec, Edyta; Kasperczyk, Sławomir

    2016-08-15

    The aim of the study was to investigate the influence of a short-term exposure to lead on the blood morphology and the levels of selected cytokines related to hematopoiesis in occupationally exposed workers. The study population included 37 males occupationally exposed to lead for 36 to 44days. Their blood lead level raised from 10.7±7.67μg/dl at baseline to the level of 49.1±14.1μg/dl at the end of the study. The level of hemoglobin and values of MCH and MCHC were decreased due to a short-term exposure to lead by 2%, 2%, and 1%, respectively. The counts of WBC, LYM, and MXD increased significantly by 5%, 7%, and 35%. Similarly, the count of PLT increased by 7%, while PDW, MPV, and P-LCR decreased by 6%, 3%, and 9%, respectively. The levels of IL-7, G-CSF, HGF, PDGF AB/BB, SCF, and PECAM-1, decreased significantly by 30%, 33%, 8%, 30%, 25%, and 20%, respectively. A short-term occupational exposure to lead results in a decreased hemoglobin level and increased counts of WBC and PLT. Changes in counts and proportions of different types of leukocytes and decreased values of PLT indices, such as PDW, MPV, and P-LCR, due to the subacute lead-exposure may be associated with lead-induced decreased levels of cytokines related to hematopoiesis, including SCF, G-CSF, IL-7, and PDGF. PMID:27298078

  12. Functional Consequences of Perturbed CXCL12 Signal Processing: Analyses of Immature Hematopoiesis in GRK6-Deficient Mice

    PubMed Central

    Chudziak, Doreen; Spohn, Gabriele; Karpova, Darja; Dauber, Katrin; Wiercinska, Eliza; Miettinen, Johanna A.; Papayannopoulou, Thalia

    2015-01-01

    Hematopoietic stem and progenitor cells (HSPCs) reside in bone marrow (BM) in an environment rich in CXCL12, the ligand for CXCR4, which is constitutively expressed on all immature hematopoietic cells in BM. This ligand-receptor pair critically controls HSPC retention and (relative) quiescence in BM. Interestingly, in a chemokine-abundant environment, CXCR4 surface expression and CXCL12 sensitivity of BM-residing HSPCs are continuously maintained. The mechanisms underlying this peculiar pattern of G-protein signal integration by BM-HSPCs are unknown. G-protein receptor kinases (GRKs) control receptor function by phosphorylating the intracellular domains upon ligand-induced activation, which results in receptor internalization and transient refractoriness. Using, therefore, a GRK6-deficient (GRK6−/−) mouse, we sought to address how perturbed ligand-induced CXCR4 (in)activation affects HSPC behavior in vitro and in vivo. In vitro, GRK6−/− HSPCs were characterized by hyper-responsiveness to CXCL12, as expected. In vivo, GRK6−/− immature hematopoiesis was characterized by a marked expansion of immature hematopoiesis in spleens and a modest repopulation defect in serial competitive transplantation. Enforced mobilization with granulocyte colony-stimulating factor (G-CSF) and AMD3100 was normal, as was hematopoietic regeneration after noncompetitive transplantation or pharmacological myelosuppression. These observations illustrate that GRK-mediated restriction of CXCR4 signal input after ligand engagement is largely dispensable for BM-resident HSPCs, which may explain how continuous CXCL12 responsiveness of BM-HSPCs can be maintained. PMID:25316534

  13. Reversibility of Defective Hematopoiesis Caused by Telomere Shortening in Telomerase Knockout Mice.

    PubMed

    Raval, Aparna; Behbehani, Gregory K; Nguyen, Le Xuan Truong; Thomas, Daniel; Kusler, Brenda; Garbuzov, Alina; Ramunas, John; Holbrook, Colin; Park, Christopher Y; Blau, Helen; Nolan, Garry P; Artandi, Steven E; Mitchell, Beverly S

    2015-01-01

    Telomere shortening is common in bone marrow failure syndromes such as dyskeratosis congenita (DC), aplastic anemia (AA) and myelodysplastic syndromes (MDS). However, improved knowledge of the lineage-specific consequences of telomere erosion and restoration of telomere length in hematopoietic progenitors is required to advance therapeutic approaches. We have employed a reversible murine model of telomerase deficiency to compare the dependence of erythroid and myeloid lineage differentiation on telomerase activity. Fifth generation Tert-/- (G5 Tert-/-) mice with shortened telomeres have significant anemia, decreased erythroblasts and reduced hematopoietic stem cell (HSC) populations associated with neutrophilia and increased myelopoiesis. Intracellular multiparameter analysis by mass cytometry showed significantly reduced cell proliferation and increased sensitivity to activation of DNA damage checkpoints in erythroid progenitors and in erythroid-biased CD150hi HSC, but not in myeloid progenitors. Strikingly, Cre-inducible reactivation of telomerase activity restored hematopoietic stem and progenitor cell (HSPC) proliferation, normalized the DNA damage response, and improved red cell production and hemoglobin levels. These data establish a direct link between the loss of TERT activity, telomere shortening and defective erythropoiesis and suggest that novel strategies to restore telomerase function may have an important role in the treatment of the resulting anemia. PMID:26133370

  14. Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers.

    PubMed

    Waterstrat, Amanda; Rector, Kyle; Geiger, Hartmut; Liang, Ying

    2016-01-01

    Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis. PMID:27503415

  15. Quantitative trait gene Slit2 positively regulates murine hematopoietic stem cell numbers

    PubMed Central

    Waterstrat, Amanda; Rector, Kyle; Geiger, Hartmut; Liang, Ying

    2016-01-01

    Hematopoietic stem cells (HSC) demonstrate natural variation in number and function. The genetic factors responsible for the variations (or quantitative traits) are largely unknown. We previously identified a gene whose differential expression underlies the natural variation of HSC numbers in C57BL/6 (B6) and DBA/2 (D2) mice. We now report the finding of another gene, Slit2, on chromosome 5 that also accounts for variation in HSC number. In reciprocal chromosome 5 congenic mice, introgressed D2 alleles increased HSC numbers, whereas B6 alleles had the opposite effect. Using gene array and quantitative polymerase chain reaction, we identified Slit2 as a quantitative trait gene whose expression was positively correlated with the number of HSCs. Ectopic expression of Slit2 not only increased the number of the long-term colony forming HSCs, but also enhanced their repopulation capacity upon transplantation. Therefore, Slit2 is a novel quantitative trait gene and a positive regulator of the number and function of murine HSCs. This finding suggests that Slit2 may be a potential therapeutic target for the effective in vitro and in vivo expansion of HSCs without compromising normal hematopoiesis. PMID:27503415

  16. Endothelial cells and hematopoiesis: a light microscopic study of fetal, normal, and pathologic human bone marrow in plastic-embedded sections.

    PubMed

    Islam, A; Glomski, C; Henderson, E S

    1992-07-01

    The origin and morphological identity of hematopoietic progenitor cells, as well as their precursor, the pleuripotential hematopoietic stem cell (HSC), has not been established. Our studies of 2 microns sectioned undecalcified plastic-embedded bone marrow (BM) from healthy human fetuses; normal adults; patients with acute myeloblastic leukemia (AML), acute lymphoblastic leukemia (ALL), and chronic granulocytic leukemia (CGL) in various stages (chronic, accelerated, acute blastic phase, and after autografting); and patients recovering from therapy-induced marrow hypoplasia suggest that proliferative hematopoietic zones exist near the endosteum (endosteal marrow) and the vascular endothelium (capillary and sinus-lining endothelium) and a maturational zone distal to these regions. In some of these areas, morphologically recognizable hematopoietic cells were seen and interpreted as emerging and maturing in a sequential progression, suggesting an origin from the endosteal or endothelial progenitors. In other loci, early hematopoietic cells were seen in close contact with the endosteal or vascular endothelial (VE) cells. This latter relationship suggested that these areas of cellular contact were important and represented sites of cell to cell interaction that may be associated with the liberation of growth factors by endosteal and endothelial cells and their action on hematopoietic progenitor cells. Following treatment-induced hypoplasia, the endosteal and VE cells were seen to modulate, transform, and migrate into the surrounding empty and edematous marrow space as fibroblasts. Later, as hemopoietic regeneration began, clusters of regenerating hematopoietic cells were seen adjacent to bone trabecule (BT) and near the vascular endothelium. We postulate that endosteal and VE cells are the equivalent of embryonal-stage, undifferentiated mesenchyme and, under the appropriate regulatory influence, are capable of modulation and transformation (differentiation) into stromal

  17. Murine Typhus, Reunion, France, 2011–2013

    PubMed Central

    Camuset, Guillaume; Socolovschi, Cristina; Moiton, Marie-Pierre; Kuli, Barbara; Foucher, Aurélie; Poubeau, Patrice; Borgherini, Gianandrea; Wartel, Guillaume; Audin, Héla; Raoult, Didier; Filleul, Laurent; Parola, Philippe; Pagès, Fréderic

    2015-01-01

    Murine typhus case was initially identified in Reunion, France, in 2012 in a tourist. Our investigation confirmed 8 autochthonous cases that occurred during January 2011–January 2013 in Reunion. Murine typhus should be considered in local patients and in travelers returning from Reunion who have fevers of unknown origin. PMID:25625653

  18. Pleiotropic roles of Notch signaling in normal, malignant, and developmental hematopoiesis in the human

    PubMed Central

    Kushwah, Rahul; Guezguez, Borhane; Lee, Jung Bok; Hopkins, Claudia I; Bhatia, Mickie

    2014-01-01

    The Notch signaling pathway is evolutionarily conserved across species and plays an important role in regulating cell differentiation, proliferation, and survival. It has been implicated in several different hematopoietic processes including early hematopoietic development as well as adult hematological malignancies in humans. This review focuses on recent developments in understanding the role of Notch signaling in the human hematopoietic system with an emphasis on hematopoietic initiation from human pluripotent stem cells and regulation within the bone marrow. Based on recent insights, we summarize potential strategies for treatment of human hematological malignancies toward the concept of targeting Notch signaling for fate regulation. PMID:25252682

  19. Caught in a Wnt storm: Complexities of Wnt signaling in hematopoiesis.

    PubMed

    Staal, Frank J T; Chhatta, Amiet; Mikkers, Harald

    2016-06-01

    The Wnt signaling pathway is an evolutionary conserved pathway that is involved in the development of almost every organ system in the body and provides self-renewal signals for most, if not all, adult stem cell systems. In recent years, this pathway has been studied by various research groups working on hematopoietic stem cells, resulting in contradicting conclusions. Here, we discuss and interpret the results of these studies and propose that Wnt dosage, the source of hematopoietic stem cells, and interactions with other pathways explain these disparate results. PMID:27016274

  20. Alteration of classical and hematopoiesis specific p53 pathway in the bone marrow hematopoietic stem/progenitor compartment facilitates leukemia progression in experimental mice.

    PubMed

    Chatterjee, Ritam; Chattopadhyay, Sukalpa; Law, Sujata

    2016-08-01

    Downregulation of p53 is associated with most of the neoplasms, however it claims additional significance for hematopoietic malignancy due to its supplementary role during hematopoiesis. Apart from the classical role as tumor suppressor, p53 during steady state hematopoiesis is associated with the maintenance of quiescent cell population in bone marrow by upregulating necdin (Ndn) and Gfi-1. We felt, it is necessary to delineate its attribution towards malignant conversion of hematopoietic system during leukemogenesis from all the possible angles. The present study deals with the characterization of N-N' Ethylnitrosourea (ENU) induced mouse model of leukemia by peripheral blood hemogram, bone marrow cytology, histology, cytochemical staining (MPO) and scanning electron microscopic study. We further investigated the alteration of conventional and hematopoiesis specific p53 pathways by flowcytometric expressional analysis of ATM, Chk-2, p53, p21, Ndn, Gfi-1 and Tie-2. The disruption of classical p53 pathway was observed in leukemic hematopoietic stem/progenitor population which involved downregulation of ATM, Chk-2, p53 and p21. Moreover, the expressional decline of Ndn and Gfi-1 hinted towards the mechanism of hindrance of hematopoietic quiescency in leukemic bone marrow. Increased expression of Tie-2 due to reverse correlation with p53 was found to be responsible for pathological angiogenesis in bone marrow together with increased blast burden in bone marrow during leukemia. The study presents the mechanistic scenario of the alteration of both classical as well as hematopoiesis specific p53 pathways in HSPC compartment triggering leukemic pathophysiology. PMID:27280487

  1. EphA2 Is a Therapy Target in EphA2-Positive Leukemias but Is Not Essential for Normal Hematopoiesis or Leukemia

    PubMed Central

    Charmsaz, Sara; Beckett, Kirrilee; Smith, Fiona M.; Bruedigam, Claudia; Moore, Andrew S.; Al-Ejeh, Fares; Lane, Steven W.; Boyd, Andrew W.

    2015-01-01

    Members of the Eph family of receptor tyrosine kinases and their membrane bound ephrin ligands have been shown to play critical roles in many developmental processes and more recently have been implicated in both normal and pathological processes in post-embryonic tissues. In particular, expression studies of Eph receptors and limited functional studies have demonstrated a role for the Eph/ephrin system in hematopoiesis and leukemogenesis. In particular, EphA2 was reported on hematopoietic stem cells and stromal cells. There are also reports of EphA2 expression in many different types of malignancies including leukemia, however there is a lack of knowledge in understanding the role of EphA2 in hematopoiesis and leukemogenesis. We explored the role of EphA2 in hematopoiesis by analyzing wild type and EphA2 knockout mice. Mature, differentiated cells, progenitors and hematopoietic stem cells derived from knockout and control mice were analyzed and no significant abnormality was detected. These studies showed that EphA2 does not have an obligatory role in normal hematopoiesis. Comparative studies using EphA2-negative MLL-AF9 leukemias derived from EphA2-knockout animals showed that there was no detectable functional role for EphA2 in the initiation or progression of the leukemic process. However, expression of EphA2 in leukemias initiated by MLL-AF9 suggested that this protein might be a possible therapy target in this type of leukemia. We showed that treatment with EphA2 monoclonal antibody IF7 alone had no effect on tumorigenicity and latency of the MLL-AF9 leukemias, while targeting of EphA2 using EphA2 monoclonal antibody with a radioactive payload significantly impaired the leukemic process. Altogether, these results identify EphA2 as a potential radio-therapeutic target in leukemias with MLL translocation. PMID:26083390

  2. Insights into monocyte-driven osteoclastogenesis and its link with hematopoiesis: regulatory roles of PECAM-1 (CD31) and SHP-1.

    PubMed

    Wu, Yue; Madri, Joseph

    2010-01-01

    Osteoclasts are derived from hematopoietic cells of monocyte-macrophage lineage. Osteoclastogenesis is orchestrated by the migration of monocytic osteoclast progenitor cells in close proximity to bone surfaces destined for resorption. Although the overall roles of monocyte migratory behavior in osteoclastogenesis remain enigmatic, impaired monocyte migration can lead to either decreased or increased osteoclastogenesis, which appears contingent upon the roles of migration in either fusion events required for osteoclast formation or terminal differentiation of osteoclasts. The cell adhesion molecule PECAM-1 (platelet endothelial cell adhesion molecule 1), in concert with the tyrosine phosphatase SHP-1 (Src homology 2-containing protein tyrosine phosphatase 1) and tyrosine kinase Syk-1 (spleen tyrosine kinase 1), functions as a negative regulator of osteoclastogenesis. Both PECAM-1 (CD31) and SHP-1 knockout mice exhibit not only increased osteoclastogenesis but also abnormal hematopoiesis, which is suggestive of the intricate interplay between hematopoiesis and osteoclastogenesis. Interestingly, the most pronounced effect of PECAM-1 deficiency on hematopoiesis is reflected by excessive megakaryocytopoiesis. Emerging data have suggested the role of megakaryocytes in bone remodeling. Megakaryocytopoiesis-osteoclastogenesis interactions are discussed herein, reconciling the discrepancies shown by different studies in this area. PECAM-1 and non-receptor tyrosine phosphatase polymorphisms have been revealed in a spectrum of diseases. The complex regulatory roles of PECAM-1 and SHP-1 in vivo suggest the potential utilization of polymorphisms of these genes for diagnostic purposes. PMID:21083524

  3. Hematopoiesis and aging. IV. Mass and distribution of erythroid marrow in aged mice

    SciTech Connect

    Boggs, D.R.

    1985-11-01

    Aged mice are ''anemic,'' i.e., they have a lower hematocrit than young adult mice, but this appears to be a ''dilutional'' anemia; the red cell mass is normal. Other observations have supported the hypothesis that basal erythropoiesis does not change as mice grow old. In the present study, the percentage of injected VZFe found in the skeleton and spleen, VZFe distribution between various bones and bone groups, and the number of nucleated erythroid cells per humerus were studied and the total mass of erythroid precursors was calculated. There was no significant difference in any of these values between mice aged 3-27 months. The variability of VZFe distribution within various skeletal parts was no greater in aged than in young mice. Thus, these data further strengthen the case for normal basal rates of erythropoiesis in aged mice.

  4. The IKAROS Interaction with a Complex Including Chromatin Remodeling and Transcription Elongation Activities Is Required for Hematopoiesis

    PubMed Central

    Bottardi, Stefania; Mavoungou, Lionel; Pak, Helen; Daou, Salima; Bourgoin, Vincent; Lakehal, Yahia A.; Affar, El Bachir; Milot, Eric

    2014-01-01

    IKAROS is a critical regulator of hematopoietic cell fate and its dynamic expression pattern is required for proper hematopoiesis. In collaboration with the Nucleosome Remodeling and Deacetylase (NuRD) complex, it promotes gene repression and activation. It remains to be clarified how IKAROS can support transcription activation while being associated with the HDAC-containing complex NuRD. IKAROS also binds to the Positive-Transcription Elongation Factor b (P-TEFb) at gene promoters. Here, we demonstrate that NuRD and P-TEFb are assembled in a complex that can be recruited to specific genes by IKAROS. The expression level of IKAROS influences the recruitment of the NuRD-P-TEFb complex to gene regulatory regions and facilitates transcription elongation by transferring the Protein Phosphatase 1α (PP1α), an IKAROS-binding protein and P-TEFb activator, to CDK9. We show that an IKAROS mutant that is unable to bind PP1α cannot sustain gene expression and impedes normal differentiation of IkNULL hematopoietic progenitors. Finally, the knock-down of the NuRD subunit Mi2 reveals that the occupancy of the NuRD complex at transcribed regions of genes favors the relief of POL II promoter-proximal pausing and thereby, promotes transcription elongation. PMID:25474253

  5. Co-transplantation of Hematopoietic Stem Cells and Cxcr4 Gene-Transduced Mesenchymal Stem Cells Promotes Hematopoiesis.

    PubMed

    Chen, Wei; Li, Miao; Su, Guizhen; Zang, Yu; Yan, Zhiling; Cheng, Hai; Pan, Bin; Cao, Jiang; Wu, Qingyun; Zhao, Kai; Zhu, Feng; Zeng, Lingyu; Li, Zhenyu; Xu, Kailin

    2015-04-01

    Mesenchymal stem cells (MSCs) are a promising candidate for cellular therapies. Co-transplantation of MSCs and hematopoietic stem cells (HSCs) promotes successful engraftment and improves hematopoietic recovery. In this study, the effects of co-transplantation of HSCs and mouse bone marrow (BM)-derived MSCs overexpressing CXCR4 (CXCR4-MSC) on CXCR4-MSC homing capacity and the reconstitution potential in lethally irradiated mice were evaluated. Recovery of donor-derived peripheral blood leukocytes and platelets was accelerated when CXCR4-MSCs were co-transplanted with BM cells. The frequency of c-kit(+)Sca(+)Lin(-) HSCs was higher in recipient BM following co-transplantation of CXCR4-MSCs compared with the EGFP-MSC control and the BMT only groups. Surprisingly, the rate of early engraftment of donor-derived BM cells in recipients co-transplanted with CXCR4-MSCs was slightly lower than in the absence of MSCs on day 7. Moreover, co-transplantation of CXCR4-MSCs regulated the balance of T helper cells subsets. Hematopoietic tissue reconstitution was evaluated by histopathological analysis of BM and spleen. Co-transplantation of CXCR4-MSCs was shown to promote the recovery of hematopoietic organs. These findings indicate that co-transplantation of CXCR4-MSCs promotes the early phase of hematopoietic recovery and sustained hematopoiesis. PMID:25391891

  6. Thrombopoietin induces hematopoiesis from mouse ES cells via HIF-1α-dependent activation of a BMP4 autoregulatory loop.

    PubMed

    Pramono, Andri; Zahabi, Azadeh; Morishima, Tatsuya; Lan, Dan; Welte, Karl; Skokowa, Julia

    2016-07-01

    Understanding the molecular mechanisms underlying hematopoietic differentiation of embryonic stem (ES) cells may help to ascertain the conditions for the in vitro generation of hematopoietic cells. Previously, we found that patients with congenital amegakaryocytic thrombocytopenia (CAMT), who develop pancytopenia early after birth, harbor mutations within the thrombopoietin (TPO) receptor, c-MPL. This knowledge, together with observations in vitro and in vivo, suggests that TPO/c-MPL signaling promotes early hematopoiesis. However, the mechanisms underlying TPO signaling are not fully elucidated. Here, we describe a direct connection between TPO and bone morphogenetic protein 4 (BMP4) signaling pathways in determining the hematopoietic fate of ES cells. Morphogen BMP4 is known to induce early hematopoietic differentiation of ES cells. Treatment of ES cells with TPO induced the autocrine production of BMP4 with concomitant upregulation of the BMP receptor BMPR1A, phosphorylation of SMAD1, 5, 8, and activation of specific BMP4 target genes; this was mediated by TPO-dependent binding of transcription factor HIF-1α to the BMP4 gene promoter. Treatment of ES cells with the BMP antagonist noggin substantially reduced TPO-dependent hematopoietic differentiation of ES cells. Thus, our findings contribute to the establishment of techniques for generating hematopoietic cells from ES cells. PMID:27447537

  7. Analysis of hematopoiesis in mice irradiated with 500 mGy of X rays at different stages of development

    SciTech Connect

    Grande, T.; Bueren, J.A.

    1995-09-01

    We have investigated whether a relatively low dose of 500 mGy of X rays given as a single acute irradiation at different stages of pre-and postnatal development induces significant changes in the content of femoral hematopoietic progenitores during a 1-year period after irradiation. Data obtained show that, in the case of 4-day-old embryos as well as in 2-day, 8-day and 12-week-old mice, this dose is below the threshold capable of inducing a long-term impairment of hematopoiesis in the mouse. Nevertheless, in mice irradiated at the 13th or the 17th day postconception, a hematopoietic dysfunction consisting of a significant reduction in the proportion of femoral granulocyte-macrophage colony-forming units (CFU-GM) was manifested 1 year after irradiation. Our study confirms that, for most stages of development in the mouse, a single acute X irradiation of 500 mGy is below the threshold dose capable of inducing deterministic effects in the mouse hematopoietic system, although it reveals the induction of a significant impairment in the CFU-GM population when irradiation is given at the late stages of embryonic development. 24 refs., 4 figs.

  8. Roles of HIPK1 and HIPK2 in AML1- and p300-dependent transcription, hematopoiesis and blood vessel formation.

    PubMed

    Aikawa, Yukiko; Nguyen, Lan Anh; Isono, Kyoichi; Takakura, Nobuyuki; Tagata, Yusuke; Schmitz, M Lienhard; Koseki, Haruhiko; Kitabayashi, Issay

    2006-09-01

    Histone acetyltransferases (HATs) p300 and CREB-binding protein (CBP) function as co-activators for a variety of sequence-specific transcription factors, including AML1. Here, we report that homeodomain-interacting protein kinase-2 (HIPK2) forms a complex with AML1 and p300, and phosphorylates both AML1 and p300 to stimulate transcription activation as well as HAT activities. Phosphorylation of p300 is triggered by phosphorylated AML1 as well as by PU.1, c-MYB, c-JUN and c-FOS, and is inhibited by dominant-negative HIPK2. Phosphorylation of p300 and AML1 is impaired in Hipk1/2 double-deficient mouse embryos. Double-deficient mice exhibit defects in primitive/definitive hematopoiesis, vasculogenesis, angiogenesis and neural tube closure. These phenotypes are in part similar to those observed in p300- and CBP-deficient mice. HIPK2 also phosphorylates another co-activator, MOZ, in an AML1-dependent manner. We discuss a possible mechanism by which transcription factors could regulate local histone acetylation and transcription of their target genes. PMID:16917507

  9. Extramedullary hematopoiesis in a case of benign mixed mammary tumor in a female dog: cytological and histopathological assessment

    PubMed Central

    2010-01-01

    Backgroud Extramedullary hematopoiesis (EMH) is defined as the presence of hematopoietic stem cells such as erythroid and myeloid lineage plus megakaryocytes in extramedullary sites like liver, spleen and lymph nodes and is usually associated with either bone marrow or hematological disorders. Mammary EMH is a rare condition either in human and veterinary medicine and can be associated with benign mixed mammary tumors, similarly to that described in this case. Case presentation Hematopoietic stem cells were found in a benign mixed mammary tumor of a 7-year-old female mongrel dog that presents a nodule in the left inguinal mammary gland. The patient did not have any hematological abnormalities. Cytological evaluation demonstrated two distinct cell populations, composed of either epithelial or mesenchymal cells, sometimes associated with a fibrillar acidophilic matrix, apart from megakaryocytes, osteoclasts, metarubricytes, prorubricytes, rubricytes, rubriblasts, promyelocytes, myeloblasts. Histological examination confirmed the presence of an active hematopoietic bone marrow within the bone tissue of a benign mammary mixed tumor. Conclusions EMH is a rare condition described in veterinary medicine that can be associated with mammary mixed tumors. It's detection can be associated with several neoplastic and non-neoplastic mammary lesions, i.e. osteosarcomas, mixed tumors and bone metaplasia. PMID:20846427

  10. Primary Myelofibrosis Presenting as Extramedullary Hematopoiesis in a Transplanted Liver Graft: Case Report and Review of the Literature

    PubMed Central

    Mohyuddin, Ghulam Rehman; Yacoub, Abdulraheem

    2016-01-01

    Primary myelofibrosis (PMF) commonly results in extramedullary hematopoiesis (EMH) in the spleen and liver as well as a variety of other organs. We present a first report of a unique presentation of PMF in a liver transplant recipient patient as EMH in the transplanted liver graft. A 76-year-old man with history of cryptogenic cirrhosis received cadaveric liver transplantation in 1996. He maintained a normal graft function and stable hematologic parameters until 2013 when he presented with anemia and progressive fatigue. Extensive work-up did not identify the etiology of the recent decline in his hemoglobin; thus a liver biopsy was done which showed findings of EMH within the sinusoids with increased megakaryocytes, some with atypical morphology. A BM biopsy revealed a hypercellular marrow, moderately increased reticulin fibrosis, and features consistent with primary myelofibrosis. Abdominal imaging showed a normal-size spleen and did not identify any sites of EMH outside of the liver. The diagnosis of myelofibrosis was thus made, and this case demonstrated predominant tropism to a transplanted liver graft with absence of EMH elsewhere. We would thus like to emphasize that findings of EMH in subjects with no preexisting hematologic neoplasm should warrant close follow-up and assessment. PMID:26885416

  11. Multifaceted roles of GSK-3 and Wnt/β-catenin in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention

    PubMed Central

    McCubrey, J A; Steelman, L S; Bertrand, F E; Davis, N M; Abrams, S L; Montalto, G; D'Assoro, A B; Libra, M; Nicoletti, F; Maestro, R; Basecke, J; Cocco, L; Cervello, M; Martelli, A M

    2014-01-01

    Glycogen synthase kinase-3 (GSK-3) is well documented to participate in a complex array of critical cellular processes. It was initially identified in rat skeletal muscle as a serine/threonine kinase that phosphorylated and inactivated glycogen synthase. This versatile protein is involved in numerous signaling pathways that influence metabolism, embryogenesis, differentiation, migration, cell cycle progression and survival. Recently, GSK-3 has been implicated in leukemia stem cell pathophysiology and may be an appropriate target for its eradication. In this review, we will discuss the roles that GSK-3 plays in hematopoiesis and leukemogenesis as how this pivotal kinase can interact with multiple signaling pathways such as: Wnt/β-catenin, phosphoinositide 3-kinase (PI3K)/phosphatase and tensin homolog (PTEN)/Akt/mammalian target of rapamycin (mTOR), Ras/Raf/MEK/extracellular signal-regulated kinase (ERK), Notch and others. Moreover, we will discuss how targeting GSK-3 and these other pathways can improve leukemia therapy and may overcome therapeutic resistance. In summary, GSK-3 is a crucial regulatory kinase interacting with multiple pathways to control various physiological processes, as well as leukemia stem cells, leukemia progression and therapeutic resistance. GSK-3 and Wnt are clearly intriguing therapeutic targets. PMID:23778311

  12. Far Upstream Element Binding Protein Plays a Crucial Role in Embryonic Development, Hematopoiesis, and Stabilizing Myc Expression Levels.

    PubMed

    Zhou, Weixin; Chung, Yang Jo; Parrilla Castellar, Edgardo R; Zheng, Ying; Chung, Hye-Jung; Bandle, Russell; Liu, Juhong; Tessarollo, Lino; Batchelor, Eric; Aplan, Peter D; Levens, David

    2016-03-01

    The transcription factor far upstream element binding protein (FBP) binds and activates the MYC promoter when far upstream element is via TFIIH helicase activity early in the transcription cycle. The fundamental biology and pathology of FBP are complex. In some tumors FBP seems pro-oncogenic, whereas in others it is a tumor suppressor. We generated an FBP knockout (Fubp1(-/-)) mouse to study FBP deficiency. FBP is embryo lethal from embryonic day 10.5 to birth. A spectrum of pathology is associated with FBP loss; besides cerebral hyperplasia and pulmonary hypoplasia, pale livers, hypoplastic spleen, thymus, and bone marrow, cardiac hypertrophy, placental distress, and small size were all indicative of anemia. Immunophenotyping of hematopoietic cells in wild-type versus knockout livers revealed irregular trilineage anemia, with deficits in colony formation. Despite normal numbers of hematopoietic stem cells, transplantation of Fubp1(-/-) hematopoietic stem cells into irradiated mice entirely failed to reconstitute hematopoiesis. In competitive transplantation assays against wild-type donor bone marrow, Fubp1(-/-) hematopoietic stem cells functioned only sporadically at a low level. Although cultures of wild-type mouse embryo fibroblasts set Myc levels precisely, Myc levels of mouse varied wildly between fibroblasts harvested from different Fubp1(-/-) embryos, suggesting that FBP contributes to Myc set point fixation. FBP helps to hold multiple physiologic processes to close tolerances, at least in part by constraining Myc expression. PMID:26774856

  13. IL-10 regulates murine lupus.

    PubMed

    Yin, Zhinan; Bahtiyar, Gul; Zhang, Na; Liu, Lanzhen; Zhu, Ping; Robert, Marie E; McNiff, Jennifer; Madaio, Michael P; Craft, Joe

    2002-08-15

    MRL/MpJ-Tnfrsf6(lpr) (MRL/MpJ-Fas(lpr); MRL-Fas(lpr)) mice develop a spontaneous lupus syndrome closely resembling human systemic lupus erythematosus. To define the role of IL-10 in the regulation of murine lupus, IL-10 gene-deficient (IL-10(-/-)) MRL-Fas(lpr) (MRL-Fas(lpr) IL-10(-/-)) mice were generated and their disease phenotype was compared with littermates with one or two copies of an intact IL-10 locus (MRL-Fas(lpr) IL-10(+/-) and MRL-Fas(lpr) IL-10(+/+) mice, respectively). MRL-Fas(lpr) IL-10(-/-) mice developed severe lupus, with earlier appearance of skin lesions, increased lymphadenopathy, more severe glomerulonephritis, and higher mortality than their IL-10-intact littermate controls. The increased severity of lupus in MRL-Fas(lpr) IL-10(-/-) mice was closely associated with enhanced IFN-gamma production by both CD4(+) and CD8(+) cells and increased serum concentration of IgG2a anti-dsDNA autoantibodies. The protective effect of IL-10 in this lupus model was further supported by the observation that administration of rIL-10 reduced IgG2a anti-dsDNA autoantibody production in wild-type MRL-Fas(lpr) animals. In summary, our results provide evidence that IL-10 can down-modulate murine lupus through inhibition of pathogenic Th1 cytokine responses. Modulation of the level of IL-10 may be of potential therapeutic benefit for human lupus. PMID:12165544

  14. Dynamic Control of Enhancer Repertoires Drives Lineage and Stage-Specific Transcription during Hematopoiesis.

    PubMed

    Huang, Jialiang; Liu, Xin; Li, Dan; Shao, Zhen; Cao, Hui; Zhang, Yuannyu; Trompouki, Eirini; Bowman, Teresa V; Zon, Leonard I; Yuan, Guo-Cheng; Orkin, Stuart H; Xu, Jian

    2016-01-11

    Enhancers are the primary determinants of cell identity, but the regulatory components controlling enhancer turnover during lineage commitment remain largely unknown. Here we compare the enhancer landscape, transcriptional factor occupancy, and transcriptomic changes in human fetal and adult hematopoietic stem/progenitor cells and committed erythroid progenitors. We find that enhancers are modulated pervasively and direct lineage- and stage-specific transcription. GATA2-to-GATA1 switch is prevalent at dynamic enhancers and drives erythroid enhancer commissioning. Examination of lineage-specific enhancers identifies transcription factors and their combinatorial patterns in enhancer turnover. Importantly, by CRISPR/Cas9-mediated genomic editing, we uncover functional hierarchy of constituent enhancers within the SLC25A37 super-enhancer. Despite indistinguishable chromatin features, we reveal through genomic editing the functional diversity of several GATA switch enhancers in which enhancers with opposing functions cooperate to coordinate transcription. Thus, genome-wide enhancer profiling coupled with in situ enhancer editing provide critical insights into the functional complexity of enhancers during development. PMID:26766440

  15. The aryl hydrocarbon receptor: Regulation of hematopoiesis and involvement in the progression of blood diseases

    PubMed Central

    Casado, Fanny L.; Singh, Kameshwar P.; Gasiewicz, Thomas A.

    2010-01-01

    The aryl hydrocarbon receptor (AhR) is a basic helix-loop-helix protein that belongs to the superfamily of environment-sensing PAS (Per-ARNT-Sim) proteins. A large number of ligands have been described to bind AhR and promote its nuclear translocation. In the nucleus, the AhR and its dimerization partner the AhR nuclear translocase (ARNT), also known as HIF1β, form a DNA-binding complex that acts as a transcriptional regulator. Animal and human data suggest that, beyond its mediating responses to xenobiotic and/or unknown endogenous ligands, the AhR has a role, although as yet undefined, in the regulation of cell cycle and inflammation. The AhR also appears to regulate the hematopoietic and immune systems during development and adult life in a cell-specific manner. While accidental exposure to xenobiotic AhR ligands has been associated with leukemia in humans, the specific mechanisms of AhR involvement are still not completely understood. However, recent data are consistent with a functional role of the AhR in the maintenance of hematopoietic stem and/or progenitor cells (HSCs/HPCs). Studies highlighting AhR-regulation of HSCs/HPCs provide a rational framework to understand their biology, a role of the AhR in hematopoietic diseases, and a means to develop interventions for these diseases. PMID:20171126

  16. Characterization of the murine 5T4 oncofoetal antigen: a target for immunotherapy in cancer.

    PubMed Central

    Woods, Andrew M; Wang, Who W; Shaw, David M; Ward, Christopher M; Carroll, Miles W; Rees, Buddug R; Stern, Peter L

    2002-01-01

    Human 5T4 oncofoetal antigen defined by the murine 5T4 monoclonal antibody is a highly glycosylated protein expressed by trophoblast and a few specialized adult epithelia. Up-regulation of 5T4 expression in some cancers is associated with poor clinical outcome; overexpression of human 5T4 cDNA in epithelial cells can alter their morphology and motility, supporting a role for such functions in cancer and development. A murine model to study 5T4 biology and tumour immunology would be useful. The production of m5T4-specific antibodies, their use in establishing transfected cells and documenting their biological properties in vitro are described. A rat monoclonal antibody specific for mouse 5T4 molecules by ELISA, flow cytometry, immunohistochemistry and immunoprecipitation was isolated and epitope mapped. Similar to its human counterpart, murine 5T4 antigen is a 72 kDa glycoprotein (immunoprecipitation and Western blot analysis) and exhibits punctate cell surface expression, dependent upon the integrity of the actin cytoskeleton. Likewise, overexpression of autologous murine 5T4 by B16 F10 melanoma cells and A9 L fibroblasts accentuates the 5T4 phenotype, which is characterized by a spindle-like morphology, increased motility, and reduced adhesion and proliferation rate. Immunohistochemical analysis of adult mouse tissues shows a restricted pattern of expression similar to that of human 5T4 antigen. The murine 5T4 antigen-expressing cell lines and antibody reagents are now being used to explore novel immunotherapies in pre-clinical models and the biology of 5T4 in development. PMID:12003637

  17. Characterization of the murine 5T4 oncofoetal antigen: a target for immunotherapy in cancer.

    PubMed

    Woods, Andrew M; Wang, Who W; Shaw, David M; Ward, Christopher M; Carroll, Miles W; Rees, Buddug R; Stern, Peter L

    2002-08-15

    Human 5T4 oncofoetal antigen defined by the murine 5T4 monoclonal antibody is a highly glycosylated protein expressed by trophoblast and a few specialized adult epithelia. Up-regulation of 5T4 expression in some cancers is associated with poor clinical outcome; overexpression of human 5T4 cDNA in epithelial cells can alter their morphology and motility, supporting a role for such functions in cancer and development. A murine model to study 5T4 biology and tumour immunology would be useful. The production of m5T4-specific antibodies, their use in establishing transfected cells and documenting their biological properties in vitro are described. A rat monoclonal antibody specific for mouse 5T4 molecules by ELISA, flow cytometry, immunohistochemistry and immunoprecipitation was isolated and epitope mapped. Similar to its human counterpart, murine 5T4 antigen is a 72 kDa glycoprotein (immunoprecipitation and Western blot analysis) and exhibits punctate cell surface expression, dependent upon the integrity of the actin cytoskeleton. Likewise, overexpression of autologous murine 5T4 by B16 F10 melanoma cells and A9 L fibroblasts accentuates the 5T4 phenotype, which is characterized by a spindle-like morphology, increased motility, and reduced adhesion and proliferation rate. Immunohistochemical analysis of adult mouse tissues shows a restricted pattern of expression similar to that of human 5T4 antigen. The murine 5T4 antigen-expressing cell lines and antibody reagents are now being used to explore novel immunotherapies in pre-clinical models and the biology of 5T4 in development. PMID:12003637

  18. Differential effects of drugs upon hematopoiesis can be assessed in long-term bone marrow cultures established on nylon screens.

    PubMed

    Naughton, B A; Sibanda, B; Azar, L; San Roman, J

    1992-04-01

    Hematotoxicity is associated with exposure to chemotherapeutic drugs and numerous other agents. Most measurements of the hematopoietic effects of prospective therapeutic drugs and environmental agents have been made in animal models. We tested the influence of various drugs on hematopoiesis in long-term cultures of Long-Evans rat bone marrow cells. These cultures were established on nylon screen-bone marrow stromal cell templates that were suspended in liquid medium. Previous phenotypic analyses of adherent zone cells of suspended nylon screen bone marrow cultures (NSBMC) using monoclonal antibodies and flow cytometry indicated that they maintain a multilineage character for extended periods in culture and display continuous proliferation of hematopoietic progenitors (colony-forming unit culture [CFU-C]). NSBMC of various ages were incubated for 21 hr with several concentrations of beta-D-cytosine arabinofuranoside, 5-fluorouracil, cyclophosphamide, or methotrexate. Adherent zone cells were dissociated enzymatically, phenotyped by flow cytometry, and assayed for colony-forming unit culture content. beta-D-cytosine arabinofuranoside, 5-fluorouracil, and methotrexate treatment of bone marrow cultures resulted in a dose-related diminution in colony-forming unit culture numbers in the adherent zones of NSBMC. Phenotypic analyses revealed similar trends but certain of these drugs manifested lineage specificities. Toxicity was also related to cyclophosphamide dose, but the presence of bone marrow stroma was necessary to demonstrate this effect in vitro. A subpopulation of these cells was found to metabolize ethoxyfluorescein ethyl ester to fluorescein after induction with 2,3,7,8-tetrachlorodibenzo-p-dioxin, an effect which was quantified by flow cytometry. NSBMC may be used to ascertain lineage-specific toxicities and evaluate the effects of drugs on the proliferation of hematopoietic progenitor cells. PMID:1549628

  19. In vivo reprogramming of murine cardiac fibroblasts into induced cardiomyocytes

    PubMed Central

    Qian, Li; Huang, Yu; Spencer, C. Ian; Foley, Amy; Vedantham, Vasanth; Liu, Lei; Conway, Simon J.; Fu, Ji-dong; Srivastava, Deepak

    2012-01-01

    SUMMARY The reprogramming of adult cells into pluripotent cells or directly into alternative adult cell types holds great promise for regenerative medicine. We reported that cardiac fibroblasts, which represent 50% of the cells in the mammalian heart, can be directly reprogrammed to adult cardiomyocyte-like cells in vitro by the addition of Gata4, Mef2c and Tbx5 (GMT). Here, we use genetic lineage-tracing to show that resident non-myocytes in the murine heart can be reprogrammed into cardiomyocyte-like cells in vivo by local delivery of GMT after coronary ligation. Induced cardiomyocytes became bi-nucleate, assembled sarcomeres and had cardiomyocyte-like gene expression. Analysis of single cells revealed ventricular cardiomyocyte-like action potentials, beating upon electrical stimulation, and evidence of electrical coupling. In vivo delivery of GMT decreased infarct size and modestly attenuated cardiac dysfunction up to 3 months after coronary ligation. Delivery of the pro-angiogenic and fibroblast activating peptide, Thymosin β4, along with GMT, resulted in further improvements in scar area and cardiac function. These findings demonstrate that cardiac fibroblasts can be reprogrammed into cardiomyocyte-like cells in their native environment for potential regenerative purposes. PMID:22522929

  20. Apoptosis in irradiated murine tumors.

    PubMed

    Stephens, L C; Ang, K K; Schultheiss, T E; Milas, L; Meyn, R E

    1991-09-01

    Early radiation responses of transplantable murine ovarian (OCaI) and hepatocellular (HCaI) carcinomas were examined at 6, 24, 48, 96, and 144 h after single photon doses of 25, 35, or 45 Gy. Previous studies using tumor growth delay and tumor radiocurability assays had shown OCaI tumors to be relatively radiosensitive and HCaI tumors to be radioresistant. At 6 h, approximately 20% of nuclei in OCaI tumors showed aberrations characteristic of cell death by apoptosis. This contrasted to an incidence of 3% in HCaI tumors. Mitotic activity was eliminated in OCaI tumors but was only transiently suppressed in HCaI tumors. At 24-96 h, OCaI tumors continued to display apoptosis and progressive necrosis, whereas HCaI tumors responded by exhibiting marked pleomorphism. Factors other than mitotic activity may influence tumor radiosensitivity, and one of these may be susceptibility to induction of apoptosis (programmed cell death), because this was a prominent early radiation response by the radiosensitive OCaI tumors. PMID:1886987

  1. Chemoimmunotherapy of murine bladder cancer.

    PubMed

    Stogdill, B J; Lamm, D L; Livingston, R B

    1981-11-01

    The lethality of invasive transitional cell carcinoma (TCC) has prompted a search for effective, minimally toxic, adjuvant therapy. Such agents were evaluated in a murine bladder cancer (MBT2) model which parallels the clinical disease. One hundred C3H/He mice were inoculated i.d. with 2.5 x 10(4) viable MBT2 tumor cells and randomized to receive either normal saline (control), cis-Platinum (CPT), cyclophosphamide (CY), methotrexate (MTX), BCG, (CY + MTX), or (CY + MTX + BCG). Chemotherapy was given intraperitoneally weekly starting on day 7 after inoculation. Immunotherapy was given intralesionally on days 1 and 10 only. All mice were treated for 5 weeks followed by 5 weeks of observation. At 5 weeks, tumors of mice receiving cyclophosphamide alone or either of the combinations of therapy were smaller (P less than 0.01) than tumors of controls or other single agents alone. Each regimen increased survival, but only the combination regimen increase survival significantly (P less than 0.01). In the doses and schedule used in this model. Combination chemotherapy and chemoimmunotherapy significantly delay tumor growth and increase duration of survival (P less than 0.01) when compared with controls or single agent groups. PMID:7298287

  2. DNA methylation analysis of murine hematopoietic side population cells during aging.

    PubMed

    Taiwo, Oluwatosin; Wilson, Gareth A; Emmett, Warren; Morris, Tiffany; Bonnet, Dominique; Schuster, Eugene; Adejumo, Tomas; Beck, Stephan; Pearce, Daniel J

    2013-10-01

    Stem cells have been found in most tissues/organs. These somatic stem cells produce replacements for lost and damaged cells, and it is not completely understood how this regenerative capacity becomes diminished during aging. To study the possible involvement of epigenetic changes in somatic stem cell aging, we used murine hematopoiesis as a model system. Hematopoietic stem cells (HSCs) were enriched for via Hoechst exclusion activity (SP-HSC) from young, medium-aged and old mice and subjected to comprehensive, global methylome (MeDIP-seq) analysis. With age, we observed a global loss of DNA methylation of approximately 5%, but an increase in methylation at some CpG islands. Just over 100 significant (FDR<0.2) aging-specific differentially methylated regions (aDMRs) were identified, which are surprisingly few considering the profound age-based changes that occur in HSC biology. Interestingly, the polycomb repressive complex -2 (PCRC2) target genes Kiss1r, Nav2 and Hsf4 were hypermethylated with age. The promoter for the Sdpr gene was determined to be progressively hypomethylated with age. This occurred concurrently with an increase in gene expression with age. To explore this relationship further, we cultured isolated SP-HSC in the presence of 5-aza-deoxycytdine and demonstrated a negative correlation between Sdpr promoter methylation and gene expression. We report that DNA methylation patterns are well preserved during hematopoietic stem cell aging, confirm that PCRC2 targets are increasingly methylated with age, and suggest that SDPR expression changes with age in HSCs may be regulated via age-based alterations in DNA methylation. PMID:23949429

  3. INCREASED SUSCEPTIBILITY TO PARATHION POISONING FOLLOWING MURINE CYTOMEGALOVIRUS INFECTION

    EPA Science Inventory

    Increased Susceptibility to Parathion Poisoning Following Murine Cytomegalovirus Infection. Fifty to 100 percent mortality occurred in mice treated with ordinarily sublethal doses of parathion 2 to 5 days post infection with murine cytomegalovirus (MCMV). These mortalities appear...

  4. Murine typhus in Kuwait in 1978

    PubMed Central

    Al-Awadi, Abdul Rahman; Al-Kazemi, Nouri; Ezzat, Gaafar; Saah, Alfred J.; Shepard, Charles; Zaghloul, Talaat; Gherdian, Beatriz

    1982-01-01

    Murine typhus occurred in 254 individuals in Kuwait between April and August 1978; 81% of patients were aged between 15 and 44 years, and 63% were male. The highest attack rate occurred among people in the lowest socioeconomic class. The outbreak coincided with a period of high rat and flea density. A study of the first 104 cases suggested that infection was acquired in the home, but a case — control study revealed no significant differences between patients and control subjects in terms of exposure to rats or domestic animals, and other factors. This suggests that murine typhus is hyperendemic rather than epidemic in Kuwait. The disease is being controlled through reduction of both flea and rat populations. Murine typhus may be much more common in many areas than is generally realized, and its status should be re-evaluated regularly in all known and potential foci. PMID:6980739

  5. Murine Norovirus: Propagation, Quantification and Genetic Manipulation

    PubMed Central

    Hwang, Seungmin; Alhatlani, Bader; Arias, Armando; Caddy, Sarah L; Christodoulou, Constantina; Cunha, Juliana; Emmott, Ed; Gonzalez-Hernandez, Marta; Kolawole, Abimbola; Lu, Jia; Rippinger, Christine; Sorgeloos, Frédéric; Thorne, Lucy; Vashist, Surender; Goodfellow, Ian

    2014-01-01

    Murine norovirus (MNV) is a positive-sense, plus-stranded RNA virus in the Caliciviridae family. It is the most common pathogen in biomedical research colonies. MNV is also related to the human noroviruses, which cause the majority of non-bacterial gastroenteritis worldwide. Like the human noroviruses, MNV is an enteric virus that replicates in the intestine and is transmitted by the fecal-oral route. MNV replicates in murine macrophages and dendritic cells in cells in culture and in the murine host. This virus is often used to study mechanisms in norovirus biology, because the human noroviruses are refractory to growth in cell culture. MNV combines the availability of a cell culture and reverse genetics system with the ability to study infection in the native host. Herein, we describe a panel of techniques that are commonly used to study MNV biology. PMID:24789596

  6. Extramedullary Pulmonary Hematopoiesis Causing Pulmonary Hypertension and Severe Tricuspid Regurgitation Detected by Technetium-99m Sulfur Colloid Bone Marrow Scan and Single-Photon Emission Computed Tomography/CT

    PubMed Central

    Clarke, Michael John; Kannivelu, Anbalagan; Chinchure, Dinesh; Srinivasan, Sivasubramanian

    2014-01-01

    Extramedullary pulmonary hematopoiesis is a rare entity with a limited number of case reports in the available literature only. We report the case of a 66-year-old man with known primary myelofibrosis, in whom a Technetium-99m sulfur colloid bone marrow scan with single-photon emission computed tomography (SPECT)/CT revealed a pulmonary hematopoiesis as the cause of pulmonary hypertension and severe tricuspid regurgitation. To the best of our knowledge, this is the first description of Technetium-99m sulfur colloid SPECT/CT imaging in this rare condition. PMID:24843243

  7. Regulation of Hematopoiesis

    PubMed Central

    Desforges, Jane F.

    1984-01-01

    These discussions are selected from the weekly staff conferences in the Department of Medicine, University of California, San Francisco. Taken from transcriptions, they are prepared by Drs Homer A. Boushey, Associate Professor of Medicine, and David G. Warnock, Associate Professor of Medicine, under the direction of Dr Lloyd H. Smith, Jr, Professor of Medicine and Chairman of the Department of Medicine. Requests for reprints should be sent to the Department of Medicine, University of California, San Francisco, School of Medicine, San Francisco, CA 94143. PMID:6382801

  8. Murine neonatal intravascular injections: Modeling newborn disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to perform murine neonatal intravascular injections likely will prove useful in studying many newborn-specific disease states that are modeled in mice. Unfortunately, effective intravascular injection in the neonatal mouse has been limited by developmental immaturity and small size. To e...

  9. Deep Sequencing of the Murine Olfactory Receptor Neuron Transcriptome

    PubMed Central

    Kanageswaran, Ninthujah; Demond, Marilen; Nagel, Maximilian; Schreiner, Benjamin S. P.; Baumgart, Sabrina; Scholz, Paul; Altmüller, Janine; Becker, Christian; Doerner, Julia F.; Conrad, Heike; Oberland, Sonja; Wetzel, Christian H.; Neuhaus, Eva M.; Hatt, Hanns; Gisselmann, Günter

    2015-01-01

    The ability of animals to sense and differentiate among thousands of odorants relies on a large set of olfactory receptors (OR) and a multitude of accessory proteins within the olfactory epithelium (OE). ORs and related signaling mechanisms have been the subject of intensive studies over the past years, but our knowledge regarding olfactory processing remains limited. The recent development of next generation sequencing (NGS) techniques encouraged us to assess the transcriptome of the murine OE. We analyzed RNA from OEs of female and male adult mice and from fluorescence-activated cell sorting (FACS)-sorted olfactory receptor neurons (ORNs) obtained from transgenic OMP-GFP mice. The Illumina RNA-Seq protocol was utilized to generate up to 86 million reads per transcriptome. In OE samples, nearly all OR and trace amine-associated receptor (TAAR) genes involved in the perception of volatile amines were detectably expressed. Other genes known to participate in olfactory signaling pathways were among the 200 genes with the highest expression levels in the OE. To identify OE-specific genes, we compared olfactory neuron expression profiles with RNA-Seq transcriptome data from different murine tissues. By analyzing different transcript classes, we detected the expression of non-olfactory GPCRs in ORNs and established an expression ranking for GPCRs detected in the OE. We also identified other previously undescribed membrane proteins as potential new players in olfaction. The quantitative and comprehensive transcriptome data provide a virtually complete catalogue of genes expressed in the OE and present a useful tool to uncover candidate genes involved in, for example, olfactory signaling, OR trafficking and recycling, and proliferation. PMID:25590618

  10. Deep sequencing of the murine olfactory receptor neuron transcriptome.

    PubMed

    Kanageswaran, Ninthujah; Demond, Marilen; Nagel, Maximilian; Schreiner, Benjamin S P; Baumgart, Sabrina; Scholz, Paul; Altmüller, Janine; Becker, Christian; Doerner, Julia F; Conrad, Heike; Oberland, Sonja; Wetzel, Christian H; Neuhaus, Eva M; Hatt, Hanns; Gisselmann, Günter

    2015-01-01

    The ability of animals to sense and differentiate among thousands of odorants relies on a large set of olfactory receptors (OR) and a multitude of accessory proteins within the olfactory epithelium (OE). ORs and related signaling mechanisms have been the subject of intensive studies over the past years, but our knowledge regarding olfactory processing remains limited. The recent development of next generation sequencing (NGS) techniques encouraged us to assess the transcriptome of the murine OE. We analyzed RNA from OEs of female and male adult mice and from fluorescence-activated cell sorting (FACS)-sorted olfactory receptor neurons (ORNs) obtained from transgenic OMP-GFP mice. The Illumina RNA-Seq protocol was utilized to generate up to 86 million reads per transcriptome. In OE samples, nearly all OR and trace amine-associated receptor (TAAR) genes involved in the perception of volatile amines were detectably expressed. Other genes known to participate in olfactory signaling pathways were among the 200 genes with the highest expression levels in the OE. To identify OE-specific genes, we compared olfactory neuron expression profiles with RNA-Seq transcriptome data from different murine tissues. By analyzing different transcript classes, we detected the expression of non-olfactory GPCRs in ORNs and established an expression ranking for GPCRs detected in the OE. We also identified other previously undescribed membrane proteins as potential new players in olfaction. The quantitative and comprehensive transcriptome data provide a virtually complete catalogue of genes expressed in the OE and present a useful tool to uncover candidate genes involved in, for example, olfactory signaling, OR trafficking and recycling, and proliferation. PMID:25590618