Pain is a life-long symptom in sickle cell disease (SCD) and a predictor of disease progression and mortality, but little is known about its molecular mechanisms. Here, we characterized pain in a targeted knockin mouse model of SCD (TOW mouse) that exclusively expresses human alleles encoding normal α- and sickle β-globin. TOW mice exhibited ongoing spontaneous pain behavior and increased sensitivity to evoked pain compared with littermate control mice expressing normal human hemoglobins. PKCδ activation was elevated in the superficial laminae of the spinal cord dorsal horn in TOW mice, specifically in GABAergic inhibitory neurons. Functional inhibition and neuron-specific silencing of PKCδ attenuated spontaneous pain, mechanical allodynia, and heat hyperalgesia in TOW mice. Furthermore, we took a hematopoietic stem cell transplantation approach to generating a SCD model in PKCδ-deficient mice. Neither spontaneous pain nor evoked pain was detected in the mice lacking PKCδ despite full establishment of SCD phenotypes. These findings support a critical role of spinal PKCδ in the development of chronic pain in SCD, which may become a potential target for pharmacological interventions.
Ying He, Diana J. Wilkie, Jonathan Nazari, Rui Wang, Robert O. Messing, Joseph DeSimone, Robert E. Molokie, Zaijie Jim Wang
Hyperactivation of the mTOR pathway impairs hematopoietic stem cell (HSC) functions and promotes leukemogenesis. mTORC1 and mTORC2 differentially control normal and leukemic stem cell functions. mTORC1 regulates p70 ribosomal protein S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E–binding (eIF4E-binding) protein 1 (4E-BP1), and mTORC2 modulates AKT activation. Given the extensive crosstalk that occurs between mTORC1 and mTORC2 signaling pathways, we assessed the role of the mTORC1 substrate S6K1 in the regulation of both normal HSC functions and in leukemogenesis driven by the mixed lineage leukemia (MLL) fusion oncogene MLL-AF9. We demonstrated that S6K1 deficiency impairs self-renewal of murine HSCs by reducing p21 expression. Loss of S6K1 also improved survival in mice transplanted with MLL-AF9–positive leukemic stem cells by modulating AKT and 4E-BP1 phosphorylation. Taken together, these results suggest that S6K1 acts through multiple targets of the mTOR pathway to promote self-renewal and leukemia progression. Given the recent interest in S6K1 as a potential therapeutic target in cancer, our results further support targeting this molecule as a potential strategy for treatment of myeloid malignancies.
Joydeep Ghosh, Michihiro Kobayashi, Baskar Ramdas, Anindya Chatterjee, Peilin Ma, Raghuveer Singh Mali, Nadia Carlesso, Yan Liu, David R. Plas, Rebecca J. Chan, Reuben Kapur
BACKGROUND. Clinical laboratory tests are now being prescribed and made directly available to consumers through retail outlets in the USA. Concerns with these test have been raised regarding the uncertainty of testing methods used in these venues and a lack of open, scientific validation of the technical accuracy and clinical equivalency of results obtained through these services.
METHODS. We conducted a cohort study of 60 healthy adults to compare the uncertainty and accuracy in 22 common clinical lab tests between one company offering blood tests obtained from finger prick (Theranos) and 2 major clinical testing services that require standard venipuncture draws (Quest and LabCorp). Samples were collected in Phoenix, Arizona, at an ambulatory clinic and at retail outlets with point-of-care services.
RESULTS. Theranos flagged tests outside their normal range 1.6× more often than other testing services (
CONCLUSION. While laboratory practice standards exist to control this variability, the disparities between testing services we observed could potentially alter clinical interpretation and health care utilization. Greater transparency and evaluation of testing technologies would increase their utility in personalized health management.
FUNDING. This work was supported by the Icahn Institute for Genomics and Multiscale Biology, a gift from the Harris Family Charitable Foundation (to J.T. Dudley), and grants from the NIH (R01 DK098242 and U54 CA189201, to J.T. Dudley, and R01 AG046170 and U01 AI111598, to E.E. Schadt).
Brian A. Kidd, Gabriel Hoffman, Noah Zimmerman, Li Li, Joseph W. Morgan, Patricia K. Glowe, Gregory J. Botwin, Samir Parekh, Nikolina Babic, Matthew W. Doust, Gregory B. Stock, Eric E. Schadt, Joel T. Dudley
Posttranscriptional control of gene expression is important for defining both normal and pathological cellular phenotypes. In vitro, RNA-binding proteins (RBPs) have recently been shown to play important roles in posttranscriptional regulation; however, the contribution of RBPs to cell specification is not well understood. Here, we determined that the RBP insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is specifically overexpressed in mixed lineage leukemia–rearranged (MLL-rearranged) B-acute lymphoblastic leukemia (B-ALL), which constitutes a subtype of this malignancy associated with poor prognosis and high risk of relapse. IGF2BP3 was required for the survival of B-ALL cell lines, as knockdown led to decreased proliferation and increased apoptosis. Enforced expression of IGF2BP3 provided murine BM cells with a strong survival advantage, led to proliferation of hematopoietic stem and progenitor cells, and skewed hematopoietic development to the B cell/myeloid lineage. Cross-link immunoprecipitation and high throughput sequencing uncovered the IGF2BP3-regulated transcriptome, which includes oncogenes
Jayanth Kumar Palanichamy, Tiffany M. Tran, Jonathan M. Howard, Jorge R. Contreras, Thilini R. Fernando, Timothy Sterne-Weiler, Sol Katzman, Masoud Toloue, Weihong Yan, Giuseppe Basso, Martina Pigazzi, Jeremy R. Sanford, Dinesh S. Rao
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
Jaclyn Andricovich, Yan Kai, Weiqun Peng, Adlen Foudi, Alexandros Tzatsos
The use of fibrinolytic agents to prevent new thrombus formation is limited by an increased risk of bleeding due to lysis of hemostatic clots that prevent hemorrhage in damaged blood vessels. We sought to develop an agent that provides thromboprophylaxis without carrying a significant risk of causing systemic fibrinolysis or disrupting hemostatic clots. We previously showed that platelet (PLT) α granule–delivered urokinase plasminogen activator (uPA) is highly effective in preventing thrombosis, while being associated with little systemic fibrinolysis or bleeding. Here, we generated a chimeric prodrug composed of a single-chain version of the variable region of an anti-αIIbβ3 mAb fused to a thrombin-activatable, low-molecular-weight pro-uPA (PLT/uPA-T). PLT/uPA-T recognizes human αIIbβ3 on both quiescent and activated platelets and is enzymatically activated specifically by thrombin. We found that this prodrug binds tightly to human platelets even after gel filtration, has a prolonged half-life in mice transgenic for human αIIb compared with that of uPA-T, and prevents clot formation in a microfluidic system. Importantly, in two murine injury models, PLT/uPA-T did not lyse preexisting clots, even when administration was delayed by as little as 10 minutes, while it concurrently prevented the development of nascent thrombi. Thus, PLT/uPA-T represents the prototype of a platelet-targeted thromboprophylactic agent that selectively targets nascent over preexisting thrombi.
Rudy E. Fuentes, Sergei Zaitsev, Hyun Sook Ahn, Vincent Hayes, M. Anna Kowalska, Michele P. Lambert, Yuhuan Wang, Donald L. Siegel, Daniel W. Bougie, Richard H. Aster, Daniel D. Myers, Victoria Stepanova, Douglas B. Cines, Vladimir R. Muzykantov, Mortimer Poncz
Iron homeostasis is tightly regulated by the membrane iron exporter ferroportin and its regulatory peptide hormone hepcidin. The hepcidin/ferroportin axis is considered a promising therapeutic target for the treatment of diseases of iron overload or deficiency. Here, we conducted a chemical screen in zebrafish to identify small molecules that decrease ferroportin protein levels. The chemical screen led to the identification of 3 steroid molecules, epitiostanol, progesterone, and mifepristone, which decrease ferroportin levels by increasing the biosynthesis of hepcidin. These hepcidin-inducing steroids (HISs) did not activate known hepcidin-inducing pathways, including the BMP and JAK/STAT3 pathways. Progesterone receptor membrane component-1 (PGRMC1) was required for HIS-dependent increases in hepcidin biosynthesis, as PGRMC1 depletion in cultured hepatoma cells and zebrafish blocked the ability of HISs to increase hepcidin mRNA levels. Neutralizing antibodies directed against PGRMC1 attenuated the ability of HISs to induce hepcidin gene expression. Inhibiting the kinases of the SRC family, which are downstream of PGRMC1, blocked the ability of HISs to increase hepcidin mRNA levels. Furthermore, HIS treatment increased hepcidin biosynthesis in mice and humans. Together, these data indicate that PGRMC1 regulates hepcidin gene expression through an evolutionarily conserved mechanism. These studies have identified drug candidates and potential therapeutic targets for the treatment of diseases of abnormal iron metabolism.
Xiang Li, David K. Rhee, Rajeev Malhotra, Claire Mayeur, Liam A. Hurst, Emily Ager, Georgia Shelton, Yael Kramer, David McCulloh, David Keefe, Kenneth D. Bloch, Donald B. Bloch, Randall T. Peterson
Thrombosis is a common, life-threatening consequence of systemic infection; however, the underlying mechanisms that drive the formation of infection-associated thrombi are poorly understood. Here, using a mouse model of systemic
Jessica R. Hitchcock, Charlotte N. Cook, Saeeda Bobat, Ewan A. Ross, Adriana Flores-Langarica, Kate L. Lowe, Mahmood Khan, C. Coral Dominguez-Medina, Sian Lax, Manuela Carvalho-Gaspar, Stefan Hubscher, G. Ed Rainger, Mark Cobbold, Christopher D. Buckley, Tim J. Mitchell, Andrea Mitchell, Nick D. Jones, N. Van Rooijen, Daniel Kirchhofer, Ian R. Henderson, David H. Adams, Steve P. Watson, Adam F. Cunningham
Thrombosis and inflammation are intricately linked in several major clinical disorders, including disseminated intravascular coagulation and acute ischemic events. The damage-associated molecular pattern molecule high-mobility group box 1 (HMGB1) is upregulated by activated platelets in multiple inflammatory diseases; however, the contribution of platelet-derived HMGB1 in thrombosis remains unexplored. Here, we generated transgenic mice with platelet-specific ablation of HMGB1 and determined that platelet-derived HMGB1 is a critical mediator of thrombosis. Mice lacking HMGB1 in platelets exhibited increased bleeding times as well as reduced thrombus formation, platelet aggregation, inflammation, and organ damage during experimental trauma/hemorrhagic shock. Platelets were the major source of HMGB1 within thrombi. In trauma patients, HMGB1 expression on the surface of circulating platelets was markedly upregulated. Moreover, evaluation of isolated platelets revealed that HMGB1 is critical for regulating platelet activation, granule secretion, adhesion, and spreading. These effects were mediated via TLR4- and MyD88-dependent recruitment of platelet guanylyl cyclase (GC) toward the plasma membrane, followed by MyD88/GC complex formation and activation of the cGMP-dependent protein kinase I (cGKI). Thus, we establish platelet-derived HMGB1 as an important mediator of thrombosis and identify a HMGB1-driven link between MyD88 and GC/cGKI in platelets. Additionally, these findings suggest a potential therapeutic target for patients sustaining trauma and other inflammatory disorders associated with abnormal coagulation.
Sebastian Vogel, Rebecca Bodenstein, Qiwei Chen, Susanne Feil, Robert Feil, Johannes Rheinlaender, Tilman E. Schäffer, Erwin Bohn, Julia-Stefanie Frick, Oliver Borst, Patrick Münzer, Britta Walker, Justin Markel, Gabor Csanyi, Patrick J. Pagano, Patricia Loughran, Morgan E. Jessup, Simon C. Watkins, Grant C. Bullock, Jason L. Sperry, Brian S. Zuckerbraun, Timothy R. Billiar, Michael T. Lotze, Meinrad Gawaz, Matthew D. Neal
Erythropoiesis requires rapid and extensive hemoglobin production. Heme activates globin transcription and translation; therefore, heme synthesis must precede globin synthesis. As free heme is a potent inducer of oxidative damage, its levels within cellular compartments require stringent regulation. Mice lacking the heme exporter FLVCR1 have a severe macrocytic anemia; however, the mechanisms that underlie erythropoiesis dysfunction in these animals are unclear. Here, we determined that erythropoiesis failure occurs in these animals at the CFU-E/proerythroblast stage, a point at which the transferrin receptor (CD71) is upregulated, iron is imported, and heme is synthesized — before ample globin is produced. From the CFU-E/proerythroblast (CD71+ Ter119– cells) stage onward, erythroid progenitors exhibited excess heme content, increased cytoplasmic ROS, and increased apoptosis. Reducing heme synthesis in FLVCR1-defient animals via genetic and biochemical approaches improved the anemia, implying that heme excess causes, and is not just associated with, the erythroid marrow failure. Expression of the cell surface FLVCR1 isoform, but not the mitochondrial FLVCR1 isoform, restored normal rbc production, demonstrating that cellular heme export is essential. Together, these studies provide insight into how heme is regulated to allow effective erythropoiesis, show that erythropoiesis fails when heme is excessive, and emphasize the importance of evaluating Ter119– erythroid cells when studying erythroid marrow failure in murine models.
Raymond T. Doty, Susan R. Phelps, Christina Shadle, Marilyn Sanchez-Bonilla, Siobán B. Keel, Janis L. Abkowitz
Protein disulfide isomerase (PDI) has two distinct CGHC redox-active sites; however, the contribution of these sites during different physiologic reactions, including thrombosis, is unknown. Here, we evaluated the role of PDI and redox-active sites of PDI in thrombosis by generating mice with blood cells and vessel wall cells lacking PDI (
Junsong Zhou, Yi Wu, Lu Wang, Lubica Rauova, Vincent M. Hayes, Mortimer Poncz, David W. Essex
The development of inhibitory antibodies to factor VIII (FVIII) is a major obstacle in using this clotting factor to treat individuals with hemophilia A. Patients with a congenital absence of FVIII do not develop central tolerance to FVIII, and therefore, any control of their FVIII-reactive lymphocytes relies upon peripheral tolerance mechanisms. Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulatory enzyme that supports Treg function and peripheral tolerance in adult life. Here, we investigated the association between IDO1 competence and inhibitor status by evaluating hemophilia A patients harboring F8-null mutations that were either inhibitor negative (
Davide Matino, Marco Gargaro, Elena Santagostino, Matteo N.D. Di Minno, Giancarlo Castaman, Massimo Morfini, Angiola Rocino, Maria E. Mancuso, Giovanni Di Minno, Antonio Coppola, Vincenzo N. Talesa, Claudia Volpi, Carmine Vacca, Ciriana Orabona, Rossana Iannitti, Maria G. Mazzucconi, Cristina Santoro, Antonella Tosti, Sara Chiappalupi, Guglielmo Sorci, Giuseppe Tagariello, Donata Belvini, Paolo Radossi, Raffaele Landolfi, Dietmar Fuchs, Louis Boon, Matteo Pirro, Emanuela Marchesini, Ursula Grohmann, Paolo Puccetti, Alfonso Iorio, Francesca Fallarino
Inherited thrombocytopenias are a group of disorders that are characterized by a low platelet count and are sometimes associated with excessive bleeding that ranges from mild to severe. We evaluated 36 unrelated patients and 17 family members displaying thrombocytopenia that were recruited to the UK Genotyping and Phenotyping of Platelets (GAPP) study. All patients had a history of excessive bleeding of unknown etiology. We performed platelet phenotyping and whole-exome sequencing (WES) on all patients and identified mutations in schlafen 14 (
Sarah J. Fletcher, Ben Johnson, Gillian C. Lowe, Danai Bem, Sian Drake, Marie Lordkipanidzé, Isabel Sánchez Guiú, Ban Dawood, José Rivera, Michael A. Simpson, Martina E. Daly, Jayashree Motwani, Peter W. Collins, Steve P. Watson, Neil V. Morgan, on behalf of the UK Genotyping and Phenotyping of Platelets study group
Epigenetic regulators play critical roles in normal hematopoiesis, and the activity of these enzymes is frequently altered in hematopoietic cancers. The major type II protein arginine methyltransferase PRMT5 catalyzes the formation of symmetric dimethyl arginine and has been implicated in various cellular processes, including pluripotency and tumorigenesis. Here, we generated
Fan Liu, Guoyan Cheng, Pierre-Jacques Hamard, Sarah Greenblatt, Lan Wang, Na Man, Fabiana Perna, Haiming Xu, Madhavi Tadi, Luisa Luciani, Stephen D. Nimer
neutropenia (SCN) is often associated with inherited heterozygous point
Ramesh C. Nayak, Lisa R. Trump, Bruce J. Aronow, Kasiani Myers, Parinda Mehta, Theodosia Kalfa, Ashley M. Wellendorf, C. Alexander Valencia, Patrick J. Paddison, Marshall S. Horwitz, H. Leighton Grimes, Carolyn Lutzko, Jose A. Cancelas
Myeloproliferative neoplasms (MPNs) are characterized by the clonal expansion of one or more myeloid cell lineage. In most cases, proliferation of the malignant clone is ascribed to defined genetic alterations. MPNs are also associated with aberrant expression and activity of multiple cytokines; however, the mechanisms by which these cytokines contribute to disease pathogenesis are poorly understood. Here, we reveal a non-redundant role for steady-state IL-33 in supporting dysregulated myelopoiesis in a murine model of MPN. Genetic ablation of the IL-33 signaling pathway was sufficient and necessary to restore normal hematopoiesis and abrogate MPN-like disease in animals lacking the inositol phosphatase SHIP. Stromal cell–derived IL-33 stimulated the secretion of cytokines and growth factors by myeloid and non-hematopoietic cells of the BM, resulting in myeloproliferation in SHIP-deficient animals. Additionally, in the transgenic JAK2V617F model, the onset of MPN was delayed in animals lacking IL-33 in radio-resistant cells. In human BM, we detected increased numbers of IL-33–expressing cells, specifically in biopsies from MPN patients. Exogenous IL-33 promoted cytokine production and colony formation by primary CD34+ MPN stem/progenitor cells from patients. Moreover, IL-33 improved the survival of JAK2V617F-positive cell lines. Together, these data indicate a central role for IL-33 signaling in the pathogenesis of MPNs.
Lukas F. Mager, Carsten Riether, Christian M. Schürch, Yara Banz, Marie-Hélène Wasmer, Regula Stuber, Alexandre P. Theocharides, Xiaohong Li, Yu Xia, Hirohisa Saito, Susumu Nakae, Gabriela M. Baerlocher, Markus G. Manz, Kathy D. McCoy, Andrew J. Macpherson, Adrian F. Ochsenbein, Bruce Beutler, Philippe Krebs
Transfusion of donor-derived platelets is commonly used for thrombocytopenia, which results from a variety of clinical conditions and relies on a constant donor supply due to the limited shelf life of these cells. Embryonic stem (ES) and induced pluripotent stem (iPS) cells represent a potential source of megakaryocytes and platelets for transfusion therapies; however, the majority of current ES/iPS cell differentiation protocols are limited by low yields of hematopoietic progeny. In both mice and humans, mutations in the gene-encoding transcription factor GATA1 cause an accumulation of proliferating, developmentally arrested megakaryocytes, suggesting that GATA1 suppression in ES and iPS cell–derived hematopoietic progenitors may enhance megakaryocyte production. Here, we engineered ES cells from WT mice to express a doxycycline-regulated (dox-regulated) shRNA that targets
Ji-Yoon Noh, Shilpa Gandre-Babbe, Yuhuan Wang, Vincent Hayes, Yu Yao, Paul Gadue, Spencer K. Sullivan, Stella T. Chou, Kellie R. Machlus, Joseph E. Italiano Jr., Michael Kyba, David Finkelstein, Jacob C. Ulirsch, Vijay G. Sankaran, Deborah L. French, Mortimer Poncz, Mitchell J. Weiss
A transition from fetal hemoglobin (HbF) to adult hemoglobin (HbA) normally occurs within a few months after birth. Increased production of HbF after this period of infancy ameliorates clinical symptoms of the major disorders of adult β-hemoglobin: β-thalassemia and sickle cell disease. The transcription factor BCL11A silences HbF and has been an attractive therapeutic target for increasing HbF levels; however, it is not clear to what extent BCL11A inhibits HbF production or mediates other developmental functions in humans. Here, we identified and characterized 3 patients with rare microdeletions of 2p15-p16.1 who presented with an autism spectrum disorder and developmental delay. Moreover, these patients all exhibited substantial persistence of HbF but otherwise retained apparently normal hematologic and immunologic function. Of the genes within 2p15-p16.1, only
Anindita Basak, Miroslava Hancarova, Jacob C. Ulirsch, Tugce B. Balci, Marie Trkova, Michal Pelisek, Marketa Vlckova, Katerina Muzikova, Jaroslav Cermak, Jan Trka, David A. Dyment, Stuart H. Orkin, Mark J. Daly, Zdenek Sedlacek, Vijay G. Sankaran
Rapidly cycling fetal and neonatal hematopoietic stem cells (HSCs) generate a pool of quiescent adult HSCs after establishing hematopoiesis in the bone marrow. We report an essential role for the trithorax group gene absent, small, or homeotic 1-like (
Morgan Jones, Jennifer Chase, Michelle Brinkmeier, Jing Xu, Daniel N. Weinberg, Julien Schira, Ann Friedman, Sami Malek, Jolanta Grembecka, Tomasz Cierpicki, Yali Dou, Sally A. Camper, Ivan Maillard
Hematopoietic stem cells (HSCs) first emerge during embryonic development within vessels such as the dorsal aorta of the aorta-gonad-mesonephros (AGM) region, suggesting that signals from the vascular microenvironment are critical for HSC development. Here, we demonstrated that AGM-derived endothelial cells (ECs) engineered to constitutively express AKT (AGM AKT-ECs) can provide an in vitro niche that recapitulates embryonic HSC specification and amplification. Specifically, nonengrafting embryonic precursors, including the VE-cadherin–expressing population that lacks hematopoietic surface markers, cocultured with AGM AKT-ECs specified into long-term, adult-engrafting HSCs, establishing that a vascular niche is sufficient to induce the endothelial-to-HSC transition in vitro. Subsequent to hematopoietic induction, coculture with AGM AKT-ECs also substantially increased the numbers of HSCs derived from VE-cadherin+CD45+ AGM hematopoietic cells, consistent with a role in supporting further HSC maturation and self-renewal. We also identified conditions that included NOTCH activation with an immobilized NOTCH ligand that were sufficient to amplify AGM-derived HSCs following their specification in the absence of AGM AKT-ECs. Together, these studies begin to define the critical niche components and resident signals required for HSC induction and self-renewal ex vivo, and thus provide insight for development of defined in vitro systems targeted toward HSC generation for therapeutic applications.
Brandon K. Hadland, Barbara Varnum-Finney, Michael G. Poulos, Randall T. Moon, Jason M. Butler, Shahin Rafii, Irwin D. Bernstein