1
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Kaur A, Venkatesan A, Kandarpa M, Talpaz M, Raghavan M. Lysosomal degradation targets mutant calreticulin and the thrombopoietin receptor in myeloproliferative neoplasms. Blood Adv 2024; 8:3372-3387. [PMID: 38640435 PMCID: PMC11255115 DOI: 10.1182/bloodadvances.2023011432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 03/24/2024] [Accepted: 04/15/2024] [Indexed: 04/21/2024] Open
Abstract
ABSTRACT Somatic mutants of calreticulin (CRT) drive myeloproliferative neoplasms (MPNs) via binding to the thrombopoietin receptor (MPL) and aberrant activation of the JAK/STAT pathway. Compared with healthy donors, platelets from mutant CRT-expressing patients with MPN display low cell surface MPL. Additionally, coexpression of MPL with an MPN-linked CRT mutant (CRTDel52) reduces cell surface MPL, suggesting that CRTDel52 may induce MPL degradation. We show that lysosomal degradation is relevant to the turnover of CRTDel52 and MPL. Furthermore, CRTDel52 increases the lysosomal localization and degradation of MPL. Mammalian target of rapamycin (mTOR) inhibitors reduce cellular CRTDel52 and MPL, secreted CRTDel52 levels, and impair CRTDel52-mediated cell proliferation. mTOR inhibition also reduces colony formation and differentiation of CD34+ cells from patients with MPN but not from healthy donors. Together, these findings indicate that low-surface MPL is a biomarker of mutant CRT-mediated MPN and that induced degradation of CRTDel52 and MPL is an avenue for therapeutic intervention.
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Affiliation(s)
- Amanpreet Kaur
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI
| | - Arunkumar Venkatesan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI
| | - Malathi Kandarpa
- Division of Hematology/Oncology, Department of Internal Medicine, University of Michigan Rogel Cancer Center, Ann Arbor, MI
| | - Moshe Talpaz
- Division of Hematology/Oncology, Department of Internal Medicine, University of Michigan Rogel Cancer Center, Ann Arbor, MI
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI
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2
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Behrens K, Kauppi M, Viney EM, Kueh AJ, Hyland CD, Willson TA, Salleh L, de Graaf CA, Babon JJ, Herold MJ, Nicola NA, Alexander WS. Differential in vivo roles of Mpl cytoplasmic tyrosine residues in murine hematopoiesis and myeloproliferative disease. Leukemia 2024; 38:1342-1352. [PMID: 38491305 PMCID: PMC11147766 DOI: 10.1038/s41375-024-02219-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/02/2024] [Accepted: 03/05/2024] [Indexed: 03/18/2024]
Abstract
Thrombopoietin (Tpo), which binds to its specific receptor, the Mpl protein, is the major cytokine regulator of megakaryopoiesis and circulating platelet number. Tpo binding to Mpl triggers activation of Janus kinase 2 (Jak2) and phosphorylation of the receptor, as well as activation of several intracellular signalling cascades that mediate cellular responses. Three tyrosine (Y) residues in the C-terminal region of the Mpl intracellular domain have been implicated as sites of phosphorylation required for regulation of major Tpo-stimulated signalling pathways: Mpl-Y565, Mpl-Y599 and Mpl-Y604. Here, we have introduced mutations in the mouse germline and report a consistent physiological requirement for Mpl-Y599, mutation of which resulted in thrombocytopenia, deficient megakaryopoiesis, low hematopoietic stem cell (HSC) number and function, and attenuated responses to myelosuppression. We further show that in models of myeloproliferative neoplasms (MPN), where Mpl is required for pathogenesis, thrombocytosis was dependent on intact Mpl-Y599. In contrast, Mpl-Y565 was required for negative regulation of Tpo responses; mutation of this residue resulted in excess megakaryopoiesis at steady-state and in response to myelosuppression, and exacerbated thrombocytosis associated with MPN.
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Affiliation(s)
- Kira Behrens
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Maria Kauppi
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Elizabeth M Viney
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Andrew J Kueh
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
- School of Cancer Medicine, La Trobe University, Heidelberg, VIC, 3084, Australia
| | - Craig D Hyland
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Tracy A Willson
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Liam Salleh
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
| | - Carolyn A de Graaf
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jeffrey J Babon
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Marco J Herold
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC, Australia
- School of Cancer Medicine, La Trobe University, Heidelberg, VIC, 3084, Australia
| | - Nicos A Nicola
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Warren S Alexander
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
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3
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Grenier JMP, El Nemer W, De Grandis M. Red Blood Cell Contribution to Thrombosis in Polycythemia Vera and Essential Thrombocythemia. Int J Mol Sci 2024; 25:1417. [PMID: 38338695 PMCID: PMC10855956 DOI: 10.3390/ijms25031417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/12/2024] Open
Abstract
Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) characterized by clonal erythrocytosis and thrombocytosis, respectively. The main goal of therapy in PV and ET is to prevent thrombohemorrhagic complications. Despite a debated notion that red blood cells (RBCs) play a passive and minor role in thrombosis, there has been increasing evidence over the past decades that RBCs may play a biological and clinical role in PV and ET pathophysiology. This review summarizes the main mechanisms that suggest the involvement of PV and ET RBCs in thrombosis, including quantitative and qualitative RBC abnormalities reported in these pathologies. Among these abnormalities, we discuss increased RBC counts and hematocrit, that modulate blood rheology by increasing viscosity, as well as qualitative changes, such as deformability, aggregation, expression of adhesion proteins and phosphatidylserine and release of extracellular microvesicles. While the direct relationship between a high red cell count and thrombosis is well-known, the intrinsic defects of RBCs from PV and ET patients are new contributors that need to be investigated in depth in order to elucidate their role and pave the way for new therapeutical strategies.
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Affiliation(s)
- Julien M. P. Grenier
- Etablissement Français du Sang PACA-Corse, Aix Marseille University, CNRS, ADES UMR 7268, 13005 Marseille, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
| | - Wassim El Nemer
- Etablissement Français du Sang PACA-Corse, Aix Marseille University, CNRS, ADES UMR 7268, 13005 Marseille, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
| | - Maria De Grandis
- Etablissement Français du Sang PACA-Corse, Aix Marseille University, CNRS, ADES UMR 7268, 13005 Marseille, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
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4
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Mahjoor M, Mahmoudvand G, Farokhi S, Shadab A, Kashfi M, Afkhami H. Double-edged sword of JAK/STAT signaling pathway in viral infections: novel insights into virotherapy. Cell Commun Signal 2023; 21:272. [PMID: 37784164 PMCID: PMC10544547 DOI: 10.1186/s12964-023-01240-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 07/19/2023] [Indexed: 10/04/2023] Open
Abstract
The Janus kinase/signal transducer and activator of transcription (JAK/STAT) is an intricate signaling cascade composed of various cytokines, interferons (IFN, growth factors, and other molecules. This pathway provides a delicate mechanism through which extracellular factors adjust gene expression, thereby acting as a substantial basis for environmental signals to influence cell growth and differentiation. The interactions between the JAK/STAT cascade and antiviral IFNs are critical to the host's immune response against viral microorganisms. Recently, with the emergence of therapeutic classes that target JAKs, the significance of this cascade has been recognized in an unprecedented way. Despite the functions of the JAK/STAT pathway in adjusting immune responses against viral pathogens, a vast body of evidence proposes the role of this cascade in the replication and pathogenesis of viral pathogens. In this article, we review the structure of the JAK/STAT signaling cascade and its role in immuno-inflammatory responses. We also highlight the paradoxical effects of this pathway in the pathogenesis of viral infections. Video Abstract.
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Affiliation(s)
- Mohamad Mahjoor
- Cellular and Molecular Research Center, Qom University of Medical Sciences, Qom, Iran
- Department of Immunology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Golnaz Mahmoudvand
- Student Research Committee, USERN Office, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Simin Farokhi
- Student Research Committee, USERN Office, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Alireza Shadab
- Department of Immunology, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
- Iran University of Medical Sciences, Deputy of Health, Tehran, Iran
| | - Mojtaba Kashfi
- Cellular and Molecular Research Center, Qom University of Medical Sciences, Qom, Iran.
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran.
- Department of Medical Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Hamed Afkhami
- Cellular and Molecular Research Center, Qom University of Medical Sciences, Qom, Iran.
- Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran.
- Department of Medical Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran.
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5
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Chhabra Y, Seiffert P, Gormal RS, Vullings M, Lee CMM, Wallis TP, Dehkhoda F, Indrakumar S, Jacobsen NL, Lindorff-Larsen K, Durisic N, Waters MJ, Meunier FA, Kragelund BB, Brooks AJ. Tyrosine kinases compete for growth hormone receptor binding and regulate receptor mobility and degradation. Cell Rep 2023; 42:112490. [PMID: 37163374 DOI: 10.1016/j.celrep.2023.112490] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 03/07/2023] [Accepted: 04/24/2023] [Indexed: 05/12/2023] Open
Abstract
Growth hormone (GH) acts via JAK2 and LYN to regulate growth, metabolism, and neural function. However, the relationship between these tyrosine kinases remains enigmatic. Through an interdisciplinary approach combining cell biology, structural biology, computation, and single-particle tracking on live cells, we find overlapping LYN and JAK2 Box1-Box2-binding regions in GH receptor (GHR). Our data implicate direct competition between JAK2 and LYN for GHR binding and imply divergent signaling profiles. We show that GHR exhibits distinct mobility states within the cell membrane and that activation of LYN by GH mediates GHR immobilization, thereby initiating its nanoclustering in the membrane. Importantly, we observe that LYN mediates cytokine receptor degradation, thereby controlling receptor turnover and activity, and this applies to related cytokine receptors. Our study offers insight into the molecular interactions of LYN with GHR and highlights important functions for LYN in regulating GHR nanoclustering, signaling, and degradation, traits broadly relevant to many cytokine receptors.
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Affiliation(s)
- Yash Chhabra
- Frazer Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; The University of Queensland, Institute for Molecular Bioscience, St. Lucia, QLD 4072, Australia; Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21204, USA.
| | - Pernille Seiffert
- Structural Biology and NMR Laboratory (SBiNLab) and REPIN, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Rachel S Gormal
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Manon Vullings
- The University of Queensland, Institute for Molecular Bioscience, St. Lucia, QLD 4072, Australia
| | | | - Tristan P Wallis
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Farhad Dehkhoda
- Frazer Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia
| | - Sowmya Indrakumar
- Structural Biology and NMR Laboratory (SBiNLab) and REPIN, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark; Structural Biology and NMR Laboratory & Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Nina L Jacobsen
- Structural Biology and NMR Laboratory (SBiNLab) and REPIN, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory & Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Nela Durisic
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Michael J Waters
- The University of Queensland, Institute for Molecular Bioscience, St. Lucia, QLD 4072, Australia
| | - Frédéric A Meunier
- The Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory (SBiNLab) and REPIN, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark.
| | - Andrew J Brooks
- Frazer Institute, The University of Queensland, Woolloongabba, QLD 4102, Australia; The University of Queensland, Institute for Molecular Bioscience, St. Lucia, QLD 4072, Australia.
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6
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McFarlane A, Pohler E, Moraga I. Molecular and cellular factors determining the functional pleiotropy of cytokines. FEBS J 2023; 290:2525-2552. [PMID: 35246947 PMCID: PMC10952290 DOI: 10.1111/febs.16420] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/26/2022] [Accepted: 03/03/2022] [Indexed: 11/30/2022]
Abstract
Cytokines are soluble factors vital for mammalian physiology. Cytokines elicit highly pleiotropic activities, characterized by their ability to induce a wide spectrum of functional responses in a diverse range of cell subsets, which makes their study very challenging. Cytokines activate signalling via receptor dimerization/oligomerization, triggering activation of the JAK (Janus kinase)/STAT (signal transducer and activator of transcription) signalling pathway. Given the strong crosstalk and shared usage of key components of cytokine signalling pathways, a long-standing question in the field pertains to how functional diversity is achieved by cytokines. Here, we discuss how biophysical - for example, ligand-receptor binding affinity and topology - and cellular - for example, receptor, JAK and STAT protein levels, endosomal compartment - parameters contribute to the modulation and diversification of cytokine responses. We review how these parameters ultimately converge into a common mechanism to fine-tune cytokine signalling that involves the control of the number of Tyr residues phosphorylated in the receptor intracellular domain upon cytokine stimulation. This results in different kinetics of STAT activation, and induction of specific gene expression programs, ensuring the generation of functional diversity by cytokines using a limited set of signalling intermediaries. We describe how these first principles of cytokine signalling have been exploited using protein engineering to design cytokine variants with more specific and less toxic responses for immunotherapy.
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Affiliation(s)
- Alison McFarlane
- Division of Cell Signalling and ImmunologySchool of Life SciencesUniversity of DundeeUK
| | - Elizabeth Pohler
- Division of Cell Signalling and ImmunologySchool of Life SciencesUniversity of DundeeUK
| | - Ignacio Moraga
- Division of Cell Signalling and ImmunologySchool of Life SciencesUniversity of DundeeUK
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7
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Desikan H, Kaur A, Pogozheva ID, Raghavan M. Effects of calreticulin mutations on cell transformation and immunity. J Cell Mol Med 2023; 27:1032-1044. [PMID: 36916035 PMCID: PMC10098294 DOI: 10.1111/jcmm.17713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Myeloproliferative neoplasms (MPNs) are cancers involving dysregulated production and function of myeloid lineage hematopoietic cells. Among MPNs, Essential thrombocythemia (ET), Polycythemia Vera (PV) and Myelofibrosis (MF), are driven by mutations that activate the JAK-STAT signalling pathway. Somatic mutations of calreticulin (CRT), an endoplasmic reticulum (ER)-localized lectin chaperone, are driver mutations in approximately 25% of ET and 35% of MF patients. The MPN-linked mutant CRT proteins have novel frameshifted carboxy-domain sequences and lack an ER retention motif, resulting in their secretion. Wild type CRT is a regulator of ER calcium homeostasis and plays a key role in the assembly of major histocompatibility complex (MHC) class I molecules, which are the ligands for antigen receptors of CD8+ T cells. Mutant CRT-linked oncogenesis results from the dysregulation of calcium signalling in cells and the formation of stable complexes of mutant CRT with myeloproliferative leukemia (MPL) protein, followed by downstream activation of the JAK-STAT signalling pathway. The intricate participation of CRT in ER protein folding, calcium homeostasis and immunity suggests the involvement of multiple mechanisms of mutant CRT-linked oncogenesis. In this review, we highlight recent findings related to the role of MPN-linked CRT mutations in the dysregulation of calcium homeostasis, MPL activation and immunity.
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Affiliation(s)
- Harini Desikan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Amanpreet Kaur
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Irina D. Pogozheva
- Department of Medicinal ChemistryCollege of Pharmacy, University of MichiganAnn ArborMichiganUSA
| | - Malini Raghavan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
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8
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Takeda K, Tago K, Funakoshi-Tago M. The indispensable role of the RNA helicase DDX5 in tumorigenesis induced by the myeloproliferative neoplasm-associated JAK2V617F mutant. Cell Signal 2023; 102:110537. [PMID: 36442590 DOI: 10.1016/j.cellsig.2022.110537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/03/2022] [Accepted: 11/22/2022] [Indexed: 11/27/2022]
Abstract
A point mutation (V617F) in the Janus kinase 2 (JAK2) gene results in the production of disorderly activated tyrosine kinase, which causes myeloproliferative neoplasms (MPN). We herein demonstrated that the RNA helicase DDX5 was highly expressed at the mRNA and protein levels through the activation of signal transducer and activator of transcription 5 (STAT5) in Ba/F3 cells expressing a JAK2V617F mutant and erythropoietin receptor (V617F/EpoR cells) and MPN patient-derived HEL cells. A treatment with the JAK1/2 inhibitor, ruxolitinib and STAT5 inhibitor, pimozide significantly inhibited DDX5 mRNA expression and enhanced the degradation of DDX5 in these cells, suggesting that the JAK2V617F mutant positively regulates DDX5 mRNA expression and DDX5 protein stability by activating STAT5. The knockdown of DDX5 specifically inhibited the activation of mechanistic target of rapamycin (mTOR) in V617F/EpoR cells and HEL cells and significantly suppressed the proliferation of these cells. Furthermore, the knockdown of DDX5 markedly suppressed tumorigenesis, splenomegaly, and liver hypertrophy caused by an inoculation of V617F/EpoR cells in nude mice. Collectively, these results revealed that JAK2V617F exhibits transforming activity by inducing the expression of DDX5 in a STAT5-dependent manner, indicating the potential of the JAK2V617F/STAT5/DDX5 axis as a therapeutic target in the treatment of MPN.
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Affiliation(s)
- Kengo Takeda
- Division of Hygienic Chemistry, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan
| | - Kenji Tago
- Division of Structural Biochemistry, Department of Biochemistry, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi-ken 329-0498, Japan.
| | - Megumi Funakoshi-Tago
- Division of Hygienic Chemistry, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo 105-8512, Japan.
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9
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Takeshita S, Kakita H, Asai S, Asai T, Mori M, Ueda H, Aoki H, Aoyama M, Yamada Y. Thrombocytopenia and insufficient thrombopoietin production in human small-for-gestational-age infants. Pediatr Res 2023; 93:619-624. [PMID: 35568734 PMCID: PMC9988681 DOI: 10.1038/s41390-022-02107-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 04/26/2022] [Accepted: 05/02/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Small-for-gestational-age (SGA) infants are at increased risk for transient thrombocytopenia. The aim of this study was to determine whether thrombocytopenia in human SGA infants is due to insufficient thrombopoietin (TPO) production. METHODS A prospective study of 202 infants with gestational age less than 37 weeks was conducted; 30 of them were SGA infants, and 172 were non-SGA infants. Thrombocytopenia was seen in 17 of 30 SGA infants and 40 of 172 non-SGA infants. RESULTS Platelet counts were significantly lower in the SGA group than in the non-SGA group at the time of the lowest platelet count within 72 h of birth. The platelet count and immature platelet fraction (IPF) were negatively correlated in non-SGA infants, but not in SGA infants. In addition, the platelet count and TPO were negatively correlated in non-SGA infants. IPF and TPO were significantly lower in SGA than in non-SGA infants with thrombocytopenia. CONCLUSION IPF increased with thrombocytopenia to promote platelet production in non-SGA infants due to increasing TPO, but not in SGA infants. This study found an association between insufficient TPO production and thrombocytopenia in SGA infants. In addition, this study is important for understanding the etiology of thrombocytopenia in SGA infants. IMPACT The immature platelet fraction was low, and serum thrombopoietin was not increased in small-for-gestational-age (SGA) infants with thrombocytopenia. Thrombocytopenia in SGA infants is due to insufficient thrombopoietin production. This study is important for understanding the etiology of thrombocytopenia in SGA infants.
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Affiliation(s)
- Satoru Takeshita
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan.,Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, 3-1 Tanabedori, Mizuho-ku, Nagoya, Aichi, 467-8603, Japan
| | - Hiroki Kakita
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan. .,Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, 3-1 Tanabedori, Mizuho-ku, Nagoya, Aichi, 467-8603, Japan.
| | - Shimpei Asai
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Takafumi Asai
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Mari Mori
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Hiroko Ueda
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
| | - Hiromasa Aoki
- Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, 3-1 Tanabedori, Mizuho-ku, Nagoya, Aichi, 467-8603, Japan
| | - Mineyoshi Aoyama
- Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, 3-1 Tanabedori, Mizuho-ku, Nagoya, Aichi, 467-8603, Japan
| | - Yasumasa Yamada
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan
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10
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Germline-somatic JAK2 interactions are associated with clonal expansion in myelofibrosis. Nat Commun 2022; 13:5284. [PMID: 36075929 PMCID: PMC9458655 DOI: 10.1038/s41467-022-32986-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 08/25/2022] [Indexed: 12/13/2022] Open
Abstract
Myelofibrosis is a rare myeloproliferative neoplasm (MPN) with high risk for progression to acute myeloid leukemia. Our integrated genomic analysis of up to 933 myelofibrosis cases identifies 6 germline susceptibility loci, 4 of which overlap with previously identified MPN loci. Virtual karyotyping identifies high frequencies of mosaic chromosomal alterations (mCAs), with enrichment at myelofibrosis GWAS susceptibility loci and recurrently somatically mutated MPN genes (e.g., JAK2). We replicate prior MPN associations showing germline variation at the 9p24.1 risk haplotype confers elevated risk of acquiring JAK2V617F mutations, demonstrating with long-read sequencing that this relationship occurs in cis. We also describe recurrent 9p24.1 large mCAs that selectively retained JAK2V617F mutations. Germline variation associated with longer telomeres is associated with increased myelofibrosis risk. Myelofibrosis cases with high-frequency JAK2 mCAs have marked reductions in measured telomere length – suggesting a relationship between telomere biology and myelofibrosis clonal expansion. Our results advance understanding of the germline-somatic interaction at JAK2 and implicate mCAs involving JAK2 as strong promoters of clonal expansion of those mutated clones. Myelofibrosis is a risk factor for the development of Acute Myeloid Leukaemia. Here, the authors carry out an integrated genomic investigation of 933 myelofibrosis patients, and identified interactions between germline and somatic variation in patients who required haematopoietic cell transplantation.
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11
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Eaton N, Boyd EK, Biswas R, Lee-Sundlov MM, Dlugi TA, Ramsey HE, Zheng S, Burns RT, Sola-Visner MC, Hoffmeister KM, Falet H. Endocytosis of the thrombopoietin receptor Mpl regulates megakaryocyte and erythroid maturation in mice. Front Oncol 2022; 12:959806. [PMID: 36110936 PMCID: PMC9468709 DOI: 10.3389/fonc.2022.959806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 07/29/2022] [Indexed: 12/13/2022] Open
Abstract
Dnm2fl/fl Pf4-Cre (Dnm2Plt-/- ) mice lacking the endocytic GTPase dynamin 2 (DNM2) in platelets and megakaryocytes (MKs) develop hallmarks of myelofibrosis. At the cellular level, the tyrosine kinase JAK2 is constitutively active but decreased in expression in Dnm2Plt-/- platelets. Additionally, Dnm2Plt-/- platelets cannot endocytose the thrombopoietin (TPO) receptor Mpl, leading to elevated circulating TPO levels. Here, we assessed whether the hyperproliferative phenotype of Dnm2Plt-/- mice was due to JAK2 constitutive activation or to elevated circulating TPO levels. In unstimulated Dnm2Plt-/- platelets, STAT3 and, to a lower extent, STAT5 were phosphorylated, but their phosphorylation was slowed and diminished upon TPO stimulation. We further crossed Dnm2Plt-/- mice in the Mpl-/- background to generate Mpl-/-Dnm2Plt-/- mice lacking Mpl ubiquitously and DNM2 in platelets and MKs. Mpl-/- Dnm2Plt-/- platelets had severely reduced JAK2 and STAT3 but normal STAT5 expression. Mpl-/- Dnm2Plt-/- mice had severely reduced bone marrow MK and hematopoietic stem and progenitor cell numbers. Additionally, Mpl-/- Dnm2Plt-/- mice had severe erythroblast (EB) maturation defects, decreased expression of hemoglobin and heme homeostasis genes and increased expression of ribosome biogenesis and protein translation genes in spleen EBs, and developed anemia with grossly elevated plasma erythropoietin (EPO) levels, leading to early fatality by postnatal day 25. Mpl-/- Dnm2Plt+/+ mice had impaired EB development at three weeks of age, which normalized with adulthood. Together, the data shows that DNM2-dependent Mpl-mediated endocytosis in platelets and MKs is required for steady-state hematopoiesis and provides novel insights into a developmentally controlled role for Mpl in normal erythropoiesis, regulating hemoglobin and heme production.
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Affiliation(s)
- Nathan Eaton
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Emily K. Boyd
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Ratnashree Biswas
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
| | - Melissa M. Lee-Sundlov
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
| | - Theresa A. Dlugi
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
| | - Haley E. Ramsey
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA, United States
- Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Shikan Zheng
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
| | - Robert T. Burns
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
| | - Martha C. Sola-Visner
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA, United States
- Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Karin M. Hoffmeister
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
- Departments of Medicine and Biochemistry, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Hervé Falet
- Translational Glycomics Center, Versiti Blood Research Institute, Milwaukee, WI, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, United States
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12
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Downes CEJ, McClure BJ, McDougal DP, Heatley SL, Bruning JB, Thomas D, Yeung DT, White DL. JAK2 Alterations in Acute Lymphoblastic Leukemia: Molecular Insights for Superior Precision Medicine Strategies. Front Cell Dev Biol 2022; 10:942053. [PMID: 35903543 PMCID: PMC9315936 DOI: 10.3389/fcell.2022.942053] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, arising from immature lymphocytes that show uncontrolled proliferation and arrested differentiation. Genomic alterations affecting Janus kinase 2 (JAK2) correlate with some of the poorest outcomes within the Philadelphia-like subtype of ALL. Given the success of kinase inhibitors in the treatment of chronic myeloid leukemia, the discovery of activating JAK2 point mutations and JAK2 fusion genes in ALL, was a breakthrough for potential targeted therapies. However, the molecular mechanisms by which these alterations activate JAK2 and promote downstream signaling is poorly understood. Furthermore, as clinical data regarding the limitations of approved JAK inhibitors in myeloproliferative disorders matures, there is a growing awareness of the need for alternative precision medicine approaches for specific JAK2 lesions. This review focuses on the molecular mechanisms behind ALL-associated JAK2 mutations and JAK2 fusion genes, known and potential causes of JAK-inhibitor resistance, and how JAK2 alterations could be targeted using alternative and novel rationally designed therapies to guide precision medicine approaches for these high-risk subtypes of ALL.
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Affiliation(s)
- Charlotte EJ. Downes
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Barbara J. McClure
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Daniel P. McDougal
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Susan L. Heatley
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
| | - John B. Bruning
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Daniel Thomas
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - David T. Yeung
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Haematology, Royal Adelaide Hospital and SA Pathology, Adelaide, SA, Australia
| | - Deborah L. White
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
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13
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Levy G, Guglielmelli P, Langmuir P, Constantinescu S. JAK inhibitors and COVID-19. J Immunother Cancer 2022; 10:jitc-2021-002838. [PMID: 35459733 PMCID: PMC9035837 DOI: 10.1136/jitc-2021-002838] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2022] [Indexed: 12/11/2022] Open
Abstract
During SARS-CoV-2 infection, the innate immune response can be inhibited or delayed, and the subsequent persistent viral replication can induce emergency signals that may culminate in a cytokine storm contributing to the severe evolution of COVID-19. Cytokines are key regulators of the immune response and virus clearance, and, as such, are linked to the—possibly altered—response to the SARS-CoV-2. They act via a family of more than 40 transmembrane receptors that are coupled to one or several of the 4 Janus kinases (JAKs) coded by the human genome, namely JAK1, JAK2, JAK3, and TYK2. Once activated, JAKs act on pathways for either survival, proliferation, differentiation, immune regulation or, in the case of type I interferons, antiviral and antiproliferative effects. Studies of graft-versus-host and systemic rheumatic diseases indicated that JAK inhibitors (JAKi) exert immunosuppressive effects that are non-redundant with those of corticotherapy. Therefore, they hold the potential to cut-off pathological reactions in COVID-19. Significant clinical experience already exists with several JAKi in COVID-19, such as baricitinib, ruxolitinib, tofacitinib, and nezulcitinib, which were suggested by a meta-analysis (Patoulias et al.) to exert a benefit in terms of risk reduction concerning major outcomes when added to standard of care in patients with COVID-19. Yet, only baricitinib is recommended in first line for severe COVID-19 treatment by the WHO, as it is the only JAKi that has proven efficient to reduce mortality in individual randomized clinical trials (RCT), especially the Adaptive COVID-19 Treatment Trial (ACTT-2) and COV-BARRIER phase 3 trials. As for secondary effects of JAKi treatment, the main caution with baricitinib consists in the induced immunosuppression as long-term side effects should not be an issue in patients treated for COVID-19. We discuss whether a class effect of JAKi may be emerging in COVID-19 treatment, although at the moment the convincing data are for baricitinib only. Given the key role of JAK1 in both type I IFN action and signaling by cytokines involved in pathogenic effects, establishing the precise timing of treatment will be very important in future trials, along with the control of viral replication by associating antiviral molecules.
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Affiliation(s)
- Gabriel Levy
- Signal Transduction and Molecular Hematology, Ludwig Institute for Cancer Research, Brussels, Belgium.,Signal Transduction on Molecular Hematology, de Duve Institute, Université Catholique de Louvain, Bruxelles, Belgium.,WELBIO, Walloon Excellence in Life Sciences and Biotechnology, Brussels, Belgium
| | - Paola Guglielmelli
- Department of Clinical and Experimental Medicine, University of Florence, Firenze, Italy.,Center of Research and Innovation for Myeloproliferative Neoplasms (CRIMM), Azienda Ospedaliero Universitaria Careggi, Firenze, Italy
| | - Peter Langmuir
- Oncology Targeted Therapeutics, Incyte Corp, Wilmington, Delaware, USA
| | - Stefan Constantinescu
- Signal Transduction and Molecular Hematology, Ludwig Institute for Cancer Research, Brussels, Belgium .,Signal Transduction on Molecular Hematology, de Duve Institute, Université Catholique de Louvain, Bruxelles, Belgium.,WELBIO, Walloon Excellence in Life Sciences and Biotechnology, Brussels, Belgium.,Nuffield Department of Medicine, Oxford University, Ludwig Institute for Cancer Research, Oxford, UK
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14
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KAHRAMAN S, DEMİRKAN F. Assessment of relation between JAK2 gene and thrombosis in myeloproliferative neoplasms. TURKISH JOURNAL OF INTERNAL MEDICINE 2022. [DOI: 10.46310/tjim.1055305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Background Thrombotic complications are the most considerable etiology causing morbidity and mortality in patients with philadelphia (Ph) negative myeloproliferative neoplasms (MPN). There are many studies evaluating the association of JAK2 mutation and risk of thrombosis in MPN with inconclusive results. We also investigated the relation between JAK2 mutation in all Ph negative MPN and thrombosis.
Material and Methods Thrombotic events and demographic features of 177 patients with Ph negative MPN were evaluated retrospectively.
Results JAK2 V617 F mutation was detected in 57% of patients with essential thrombocythemia (ET), %90.3 of pateints with polycythemia vera (PV), 100% of pateints with primary myelofibrosis (PMF). Thrombotic complications occured more frequently with JAK2 mutation in all MPN patients than without (p=0.014). In JAK 2 mutation positive groups, the median age, thrombosis risk scores and leucocyte values are higher, splenomegaly and arterial and/or venous thrombosis are detected more frequently (p
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15
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Guglielmelli P, Calabresi L. The MPL mutation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 365:163-178. [PMID: 34756243 DOI: 10.1016/bs.ircmb.2021.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Myeloproliferative neoplasms (MPN) patients share driver mutations in JAK2, MPL or CALR genes leading to the activation of the thrombopoietin receptor (TPOR) and downstream signaling pathways. JAK2 mutation drives all the three major entities of MPN (Polycythemia Vera, Essential Thrombocythemia and Primary Myelofibrosis) through the constitutive activation of TPOR, erythropoietin (EPOR) and colony stimulating factor 3 receptor (CSF3R) signaling. MPL is a proto-oncogene encoding for TPOR, the hematopoietic growth factor receptor of myeloid stem cells. MPL mutants induce the stable dimerization of TPOR that in turn activate JAK2 and the thrombopoietin pathway. The thrombopoietin pathway plays an important role in the development of megakaryocytes and platelets as well as the self-renewal of hematopoietic stem cells. Little wonder therefore that mutations of MPL result in thrombocytosis, leading to an abnormal MPL trafficking or receptor activation. Finally, some extremely rare germline genetic variants in MPL can induce MPN-like hereditary disease. Against this molecular background, TPOR is a key actor in the MPN development and MPL mutations are of major relevance to fully elucidate the molecular mechanisms underlying the clinical manifestations of MPN and to arrange novel therapeutic strategies aiming to disrupt the dysegulated signaling cascade. This chapter will focus on the role MPL in the pathogenesis of MPN and in familial thrombocytosis and will review these different subtypes of somatic and germline genetic variants by dissecting how they impact clinical phenotype.
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Affiliation(s)
- Paola Guglielmelli
- Department of Experimental and Clinical Medicine, Center for Research and Innovation of Myeloproliferative Neoplasms (CRIMM), AOU Careggi, University of Florence, Florence, Italy.
| | - Laura Calabresi
- Department of Experimental and Clinical Medicine, Center for Research and Innovation of Myeloproliferative Neoplasms (CRIMM), AOU Careggi, University of Florence, Florence, Italy
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16
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Roy A, Shrivastva S, Naseer S. In and out: Traffic and dynamics of thrombopoietin receptor. J Cell Mol Med 2021; 25:9073-9083. [PMID: 34448528 PMCID: PMC8500957 DOI: 10.1111/jcmm.16878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/27/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022] Open
Abstract
Thrombopoiesis had long been a challenging area of study due to the rarity of megakaryocyte precursors in the bone marrow and the incomplete understanding of its regulatory cytokines. A breakthrough was achieved in the early 1990s with the discovery of the thrombopoietin receptor (TpoR) and its ligand thrombopoietin (TPO). This accelerated research in thrombopoiesis, including the uncovering of the molecular basis of myeloproliferative neoplasms (MPN) and the advent of drugs to treat thrombocytopenic purpura. TpoR mutations affecting its membrane dynamics or transport were increasingly associated with pathologies such as MPN and thrombocytosis. It also became apparent that TpoR affected hematopoietic stem cell (HSC) quiescence while priming hematopoietic stem cells (HSCs) towards the megakaryocyte lineage. Thorough knowledge of TpoR surface localization, dimerization, dynamics and stability is therefore crucial to understanding thrombopoiesis and related pathologies. In this review, we will discuss the mechanisms of TpoR traffic. We will focus on the recent progress in TpoR membrane dynamics and highlight the areas that remain unexplored.
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Affiliation(s)
- Anita Roy
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saurabh Shrivastva
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saadia Naseer
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
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17
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Bleeding diathesis in mice lacking JAK2 in platelets. Blood Adv 2021; 5:2969-2981. [PMID: 34342643 DOI: 10.1182/bloodadvances.2020003032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 04/14/2021] [Indexed: 12/18/2022] Open
Abstract
The tyrosine kinase JAK2 is a critical component of intracellular JAK/STAT cytokine signaling cascades that is prevalent in hematopoietic cells, such as hematopoietic stem cells and megakaryocytes (MKs). Individuals expressing the somatic JAK2 V617F mutation commonly develop myeloproliferative neoplasms (MPNs) associated with venous and arterial thrombosis, a leading cause of mortality. The role of JAK2 in hemostasis remains unclear. We investigated the role of JAK2 in platelet hemostatic function using Jak2fl/fl Pf4-Cre (Jak2Plt-/-) mice lacking JAK2 in platelets and MKs. Jak2Plt-/- mice developed MK hyperplasia and splenomegaly associated with severe thrombocytosis and bleeding. This notion was supported by failure to occlude in a ferric chloride carotid artery injury model and by a cremaster muscle laser-induced injury assay, in which Jak2Plt-/- platelets failed to form stable thrombi. Jak2Plt-/- platelets formed thrombi poorly after adhesion to type 1 collagen under arterial shear rates. Jak2Plt-/- platelets spread poorly on collagen under static conditions or on fibrinogen in response to the collagen receptor GPVI-specific agonist, collagen-related peptide (CRP). After activation with collagen, CRP, or the CLEC-2 agonist rhodocytin, Jak2Plt-/- platelets displayed decreased α-granule secretion and integrin αIIbβ3 activation or aggregation, but showed normal responses to thrombin. Jak2Plt-/- platelets had impaired intracellular signaling when activated via GPVI, as assessed by tyrosine phosphorylation. Together, the results show that JAK2 deletion impairs platelet immunoreceptor tyrosine-based activation motif signaling and hemostatic function in mice and suggest that aberrant JAK2 signaling in patients with MPNs affects GPVI signaling, leading to hemostatic platelet function.
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18
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CALR mutant protein rescues the response of MPL p.R464G variant associated with CAMT to eltrombopag. Blood 2021; 138:480-485. [PMID: 34010413 DOI: 10.1182/blood.2020010567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/20/2021] [Indexed: 11/20/2022] Open
Abstract
Congenital amegakaryocytic thrombocytopenia (CAMT) is a severe inherited thrombocytopenia due to loss-of-function mutations affecting the thrombopoietin (TPO) receptor, MPL. Here, we report a new homozygous MPL variant responsible for CAMT in one consanguineous family. The propositus and her sister presented with severe thrombocytopenia associated with mild anemia. NGS revealed the presence of a homozygous MPLR464G mutation resulting in a weak cell surface expression of the receptor in platelets. In cell lines, we observed a defect in MPLR464G maturation associated to its retention in the endoplasmic reticulum. The low cell surface expression of MPLR464G induced very limited signaling with TPO stimulation, leading to survival and reduced proliferation of cells. Overexpression of a myeloproliferative neoplasm-associated calreticulin mutant did not rescue trafficking of MPLR464G to the cell surface and did not induce constitutive signaling. However, it unexpectedly restored a normal response to eltrombopag (ELT), but not to TPO. This effect was only partially mimicked by the purified recombinant calreticulin mutant protein. Finally, the endogenous calreticulin mutant was able to restore the megakaryocyte differentiation of patient CD34+ cells carrying MPLR464G in response to ELT.
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Spivak JL, Moliterno AR. The Thrombopoietin Receptor, MPL, Is a Therapeutic Target of Opportunity in the MPN. Front Oncol 2021; 11:641613. [PMID: 33777803 PMCID: PMC7987816 DOI: 10.3389/fonc.2021.641613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/28/2021] [Indexed: 12/12/2022] Open
Abstract
The myeloproliferative neoplasms, polycythemia vera, essential thrombocytosis and primary myelofibrosis share driver mutations that either activate the thrombopoietin receptor, MPL, or indirectly activate it through mutations in the gene for JAK2, its cognate tyrosine kinase. Paradoxically, although the myeloproliferative neoplasms are classified as neoplasms because they are clonal hematopoietic stem cell disorders, the mutations affecting MPL or JAK2 are gain-of-function, resulting in increased production of normal erythrocytes, myeloid cells and platelets. Constitutive JAK2 activation provides the basis for the shared clinical features of the myeloproliferative neoplasms. A second molecular abnormality, impaired posttranslational processing of MPL is also shared by these disorders but has not received the recognition it deserves. This abnormality is important because MPL is the only hematopoietic growth factor receptor expressed in hematopoietic stem cells; because MPL is a proto-oncogene; because impaired MPL processing results in chronic elevation of plasma thrombopoietin, and since these diseases involve normal hematopoietic stem cells, they have proven resistant to therapies used in other myeloid neoplasms. We hypothesize that MPL offers a selective therapeutic target in the myeloproliferative neoplasms since impaired MPL processing is unique to the involved stem cells, while MPL is required for hematopoietic stem cell survival and quiescent in their bone marrow niches. In this review, we will discuss myeloproliferative neoplasm hematopoietic stem cell pathophysiology in the context of the behavior of MPL and its ligand thrombopoietin and the ability of thrombopoietin gene deletion to abrogate the disease phenotype in vivo in a JAK2 V617 transgenic mouse model of PV.
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Affiliation(s)
- Jerry L Spivak
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, Baltimore, MD, United States
| | - Alison R Moliterno
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine Baltimore, Baltimore, MD, United States
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20
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Abstract
Megakaryocytes give rise to platelets, which have a wide variety of functions in coagulation, immune response, inflammation, and tissue repair. Dysregulation of megakaryocytes is a key feature of in the myeloproliferative neoplasms, especially myelofibrosis. Megakaryocytes are among the main drivers of myelofibrosis by promoting myeloproliferation and bone marrow fibrosis. In vivo targeting of megakaryocytes by genetic and pharmacologic approaches ameliorates the disease, underscoring the important role of megakaryocytes in myeloproliferative neoplasms. Here we review the current knowledge of the function of megakaryocytes in the JAK2, CALR, and MPL-mutant myeloproliferative neoplasms.
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21
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Cui L, Moraga I, Lerbs T, Van Neste C, Wilmes S, Tsutsumi N, Trotman-Grant AC, Gakovic M, Andrews S, Gotlib J, Darmanis S, Enge M, Quake S, Hitchcock IS, Piehler J, Garcia KC, Wernig G. Tuning MPL signaling to influence hematopoietic stem cell differentiation and inhibit essential thrombocythemia progenitors. Proc Natl Acad Sci U S A 2021; 118:e2017849118. [PMID: 33384332 PMCID: PMC7812794 DOI: 10.1073/pnas.2017849118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Thrombopoietin (TPO) and the TPO-receptor (TPO-R, or c-MPL) are essential for hematopoietic stem cell (HSC) maintenance and megakaryocyte differentiation. Agents that can modulate TPO-R signaling are highly desirable for both basic research and clinical utility. We developed a series of surrogate protein ligands for TPO-R, in the form of diabodies (DBs), that homodimerize TPO-R on the cell surface in geometries that are dictated by the DB receptor binding epitope, in effect "tuning" downstream signaling responses. These surrogate ligands exhibit diverse pharmacological properties, inducing graded signaling outputs, from full to partial TPO agonism, thus decoupling the dual functions of TPO/TPO-R. Using single-cell RNA sequencing and HSC self-renewal assays we find that partial agonistic diabodies preserved the stem-like properties of cultured HSCs, but also blocked oncogenic colony formation in essential thrombocythemia (ET) through inverse agonism. Our data suggest that dampening downstream TPO signaling is a powerful approach not only for HSC preservation in culture, but also for inhibiting oncogenic signaling through the TPO-R.
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Affiliation(s)
- Lu Cui
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Ignacio Moraga
- HHMI, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
- School of Life Sciences, University of Dundee, Dundee DD15EH, United Kingdom
| | - Tristan Lerbs
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Camille Van Neste
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Stephan Wilmes
- School of Life Sciences, University of Dundee, Dundee DD15EH, United Kingdom
| | - Naotaka Tsutsumi
- HHMI, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Aaron Claudius Trotman-Grant
- HHMI, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Milica Gakovic
- HHMI, Stanford University School of Medicine, Stanford, CA 94305
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
- School of Life Sciences, University of Dundee, Dundee DD15EH, United Kingdom
| | - Sarah Andrews
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, YO10 5DD York, United Kingdom
| | - Jason Gotlib
- Department of Medicine, Division of Hematology, Stanford University School of Medicine, Stanford, CA 94305
| | - Spyros Darmanis
- Department of Bioengineering, School of Bioengineering and Medicine, Stanford University, Stanford, CA 94305
- Microchemistry, Proteomics, Lipidomics and NGS Department Genentech Inc., South San Francisco, CA, 94080
| | - Martin Enge
- Department of Bioengineering, School of Bioengineering and Medicine, Stanford University, Stanford, CA 94305
- Department of Oncology-Pathology Karolinska Institutet, 171 64 Stockholm, Sweden
| | - Stephen Quake
- Department of Bioengineering, School of Bioengineering and Medicine, Stanford University, Stanford, CA 94305
| | - Ian S Hitchcock
- York Biomedical Research Institute, Department of Biology, University of York, Heslington, YO10 5DD York, United Kingdom
| | - Jacob Piehler
- Department of Biology and Center for Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany
| | - K Christopher Garcia
- HHMI, Stanford University School of Medicine, Stanford, CA 94305;
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - Gerlinde Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305;
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305
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22
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Märklin M, Tandler C, Kopp HG, Hoehn KL, Quintanilla-Martinez L, Borst O, Müller MR, Saur SJ. C-Cbl regulates c-MPL receptor trafficking and its internalization. J Cell Mol Med 2020; 24:12491-12503. [PMID: 32954656 PMCID: PMC7687000 DOI: 10.1111/jcmm.15785] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 01/11/2023] Open
Abstract
Thrombocyte formation from megakaryocyte and their progenitor cells is tightly regulated by thrombopoietin (TPO) and its receptor c‐MPL, thereby maintaining physiological functionality and numbers of circulating platelets. In patients, dysfunction of this regulation could cause thrombocytopenia or myeloproliferative syndromes. Since regulation of this pathway is still not completely understood, we investigated the role of the ubiquitin ligase c‐Cbl which was previously shown to negatively regulated c‐MPL signalling. We developed a new conditional mouse model using c‐Cblfl/flPf4Cre mice and demonstrated that platelet‐specific knockout of c‐Cbl led to severe microthrombocytosis and impaired uptake of TPO and c‐MPL receptor internalization. Furthermore, we characterized a constitutive STAT5 activation c‐Cbl KO platelets. This study identified c‐Cbl as a potential player in causing megakaryocytic and thrombocytic disorders.
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Affiliation(s)
- Melanie Märklin
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), German Cancer Research Centre (DKFZ), University Hospital Tübingen, Tübingen, Germany
| | - Claudia Tandler
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), German Cancer Research Centre (DKFZ), University Hospital Tübingen, Tübingen, Germany
| | - Hans-Georg Kopp
- Department of Molecular Oncology and Thoracic Oncology, Robert-Bosch-Hospital Stuttgart, Stuttgart, Germany
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | | | - Oliver Borst
- Department of Kardiology and Angiology, University Hospital Tübingen, Tübingen, Germany
| | - Martin R Müller
- Department of Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany.,Department of Hematology, Oncology and Immunology, Klinikum Region Hannover, KRH Klinikum Siloah, Hannover, Germany
| | - Sebastian J Saur
- Department of Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
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23
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Spivak JL, Merchant A, Williams DM, Rogers O, Zhao W, Duffield A, Resar LS, Moliterno AR, Zhao ZJ. Thrombopoietin is required for full phenotype expression in a JAK2V617F transgenic mouse model of polycythemia vera. PLoS One 2020; 15:e0232801. [PMID: 32479500 PMCID: PMC7263591 DOI: 10.1371/journal.pone.0232801] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/21/2020] [Indexed: 12/30/2022] Open
Abstract
The myeloproliferative neoplasms, polycythemia vera, essential thrombocytosis and primary myelofibrosis are hematopoietic stem cell disorders and share driver mutations that either directly activate the thrombopoietin receptor, MPL, or activate it indirectly through gain-of-function mutations in the gene for JAK2, its cognate tyrosine kinase. Paradoxically, MPL surface expression in hematopoietic stem cells is also reduced in the myeloproliferative neoplasms due to abnormal post-translational glycosylation and premature destruction of JAK2, suggesting that the myeloproliferative neoplasms are disorders of MPL processing since MPL is the only hematopoietic growth factor receptor in hematopoietic stem cells. To examine this possibility, we genetically manipulated MPL expression and maturation in a JAK2V617F transgenic mouse model of polycythemia vera. Elimination of MPL expression completely abrogated the polycythemia vera phenotype in this JAK2V617F transgenic mouse model, which could only be partially restored by expression of one MPL allele. Most importantly, elimination of thrombopoietin gene expression abrogated the polycythemia vera phenotype in this JAK2V617F transgenic mouse model, which could be completely restored by expression of a single thrombopoietin allele. These data indicate that polycythemia vera is in part a thrombopoietin-dependent disorder and that targeting the MPL-thrombopoietin axis could be an effective, nonmyelotoxic therapeutic strategy in this disorder.
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Affiliation(s)
- Jerry L. Spivak
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
| | - Akil Merchant
- Samuel Oschin Comprehensive Cancer Institute, Blood and Marrow Transplant Program, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - Donna M. Williams
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ophelia Rogers
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Wanke Zhao
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Amy Duffield
- Department of Pathology, Hematologic Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Linda S. Resar
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Alison R. Moliterno
- Hematology Division, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Zhizhuang J. Zhao
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
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24
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Wilmes S, Hafer M, Vuorio J, Tucker JA, Winkelmann H, Löchte S, Stanly TA, Pulgar Prieto KD, Poojari C, Sharma V, Richter CP, Kurre R, Hubbard SR, Garcia KC, Moraga I, Vattulainen I, Hitchcock IS, Piehler J. Mechanism of homodimeric cytokine receptor activation and dysregulation by oncogenic mutations. Science 2020; 367:643-652. [PMID: 32029621 PMCID: PMC8117407 DOI: 10.1126/science.aaw3242] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 10/08/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022]
Abstract
Homodimeric class I cytokine receptors are assumed to exist as preformed dimers that are activated by ligand-induced conformational changes. We quantified the dimerization of three prototypic class I cytokine receptors in the plasma membrane of living cells by single-molecule fluorescence microscopy. Spatial and spatiotemporal correlation of individual receptor subunits showed ligand-induced dimerization and revealed that the associated Janus kinase 2 (JAK2) dimerizes through its pseudokinase domain. Oncogenic receptor and hyperactive JAK2 mutants promoted ligand-independent dimerization, highlighting the formation of receptor dimers as the switch responsible for signal activation. Atomistic modeling and molecular dynamics simulations based on a detailed energetic analysis of the interactions involved in dimerization yielded a mechanistic blueprint for homodimeric class I cytokine receptor activation and its dysregulation by individual mutations.
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Affiliation(s)
- Stephan Wilmes
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Maximillian Hafer
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Joni Vuorio
- Department of Physics, University of Helsinki, Helsinki, Finland
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Julie A Tucker
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Hauke Winkelmann
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Sara Löchte
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Tess A Stanly
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Katiuska D Pulgar Prieto
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Chetan Poojari
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Christian P Richter
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Rainer Kurre
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Stevan R Hubbard
- Skirball Institute and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - K Christopher Garcia
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ignacio Moraga
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland.
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Ian S Hitchcock
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK.
| | - Jacob Piehler
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany.
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25
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Labuhn M, Perkins K, Matzk S, Varghese L, Garnett C, Papaemmanuil E, Metzner M, Kennedy A, Amstislavskiy V, Risch T, Bhayadia R, Samulowski D, Hernandez DC, Stoilova B, Iotchkova V, Oppermann U, Scheer C, Yoshida K, Schwarzer A, Taub JW, Crispino JD, Weiss MJ, Hayashi Y, Taga T, Ito E, Ogawa S, Reinhardt D, Yaspo ML, Campbell PJ, Roberts I, Constantinescu SN, Vyas P, Heckl D, Klusmann JH. Mechanisms of Progression of Myeloid Preleukemia to Transformed Myeloid Leukemia in Children with Down Syndrome. Cancer Cell 2019; 36:123-138.e10. [PMID: 31303423 PMCID: PMC6863161 DOI: 10.1016/j.ccell.2019.06.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/07/2019] [Accepted: 06/11/2019] [Indexed: 12/22/2022]
Abstract
Myeloid leukemia in Down syndrome (ML-DS) clonally evolves from transient abnormal myelopoiesis (TAM), a preleukemic condition in DS newborns. To define mechanisms of leukemic transformation, we combined exome and targeted resequencing of 111 TAM and 141 ML-DS samples with functional analyses. TAM requires trisomy 21 and truncating mutations in GATA1; additional TAM variants are usually not pathogenic. By contrast, in ML-DS, clonal and subclonal variants are functionally required. We identified a recurrent and oncogenic hotspot gain-of-function mutation in myeloid cytokine receptor CSF2RB. By a multiplex CRISPR/Cas9 screen in an in vivo murine TAM model, we tested loss-of-function of 22 recurrently mutated ML-DS genes. Loss of 18 different genes produced leukemias that phenotypically, genetically, and transcriptionally mirrored ML-DS.
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MESH Headings
- Animals
- Biomarkers, Tumor/genetics
- Cell Transformation, Neoplastic/genetics
- Chromosomes, Human, Pair 21
- Cytokine Receptor Common beta Subunit/genetics
- Disease Models, Animal
- Disease Progression
- Down Syndrome/diagnosis
- Down Syndrome/genetics
- GATA1 Transcription Factor/genetics
- GATA1 Transcription Factor/metabolism
- Gene Expression Regulation, Leukemic
- Genetic Predisposition to Disease
- HEK293 Cells
- Humans
- Leukemia, Myeloid/diagnosis
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/pathology
- Leukemoid Reaction/diagnosis
- Leukemoid Reaction/genetics
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Transgenic
- Mutation
- Phenotype
- Transcription, Genetic
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Affiliation(s)
- Maurice Labuhn
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Kelly Perkins
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Sören Matzk
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany; Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Leila Varghese
- Ludwig Institute for Cancer Research Brussels Branch, 1200 Brussels, Belgium
| | - Catherine Garnett
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Elli Papaemmanuil
- Departments of Epidemiology and Biostatistics and Cancer Biology, MSKCC, New York, NY 10065, USA
| | - Marlen Metzner
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Alison Kennedy
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | | | - Thomas Risch
- Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Raj Bhayadia
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany
| | - David Samulowski
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany
| | - David Cruz Hernandez
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Bilyana Stoilova
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Valentina Iotchkova
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Udo Oppermann
- Botnar Research Centre, NDORMS, Oxford NIHR BRC and Structural Genomics Consortium, UK University of Oxford, Oxford OX3 7LD, UK
| | - Carina Scheer
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Kenichi Yoshida
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8315 Japan
| | - Adrian Schwarzer
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Jeffrey W Taub
- Division of Pediatric Hematology/Oncology, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - John D Crispino
- Division of Hematology/Oncology, Northwestern University, Chicago, IL 60611, USA
| | - Mitchell J Weiss
- Hematology Department, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yasuhide Hayashi
- Institute of Physiology and Medicine, Jobu University, Takasaki-shi, Gunma 370-0033, Japan
| | - Takashi Taga
- Department of Pediatrics, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Etsuro Ito
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8315 Japan; Center for Hematology and Regenerative Medicine, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Dirk Reinhardt
- Pediatric Hematology and Oncology, Pediatrics III, University Hospital Essen, 45122 Essen, Germany
| | | | - Peter J Campbell
- Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
| | - Irene Roberts
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK; Department of Paediatrics, University of Oxford, Oxford OX3 9DS, UK
| | | | - Paresh Vyas
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK; Department of Haematology, Oxford University Hospitals NHS Trust, Oxford OX3 7LE, UK.
| | - Dirk Heckl
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
| | - Jan-Henning Klusmann
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
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27
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Vainchenker W, Plo I, Marty C, Varghese LN, Constantinescu SN. The role of the thrombopoietin receptor MPL in myeloproliferative neoplasms: recent findings and potential therapeutic applications. Expert Rev Hematol 2019; 12:437-448. [PMID: 31092065 DOI: 10.1080/17474086.2019.1617129] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Classical Myeloproliferative Neoplasms (MPNs) include three disorders: Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). MPNs are associated with constitutive activation of JAK2 leading to persistent cell signaling downstream of the dimeric myeloid cytokine receptors due to mutations in three genes encoding JAK2, calreticulin (CALR) and the thrombopoietin (TPO) receptor (MPL or TPOR). CALR and MPL mutants induce JAK2 activation that depends on MPL expression, thus explaining why they induce megakaryocyte pathologies including ET and PMF, but not PV. In contrast, JAK2 V617F drives all three diseases as it induces persistent signaling via EPOR, G-CSFR (CSF3R) and MPL. Areas Covered: Here, we review how different pathogenic mutations of MPL are translated into active receptors by inducing stable dimerization. We focus on the unique role of MPL on the hematopoietic stem cell (HSC), explaining why MPL is indispensable for the development of all MPNs. Last but not least, we describe how CALR mutants are pathogenic via binding and activation of MPL. Expert Opinion: Altogether, we believe that MPL is an important, but challenging, therapeutic target in MPNs that requires novel strategies to interrupt the specific conformational changes induced by each mutation or pathologic interaction without compromising the key functions of wild type MPL.
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Affiliation(s)
- William Vainchenker
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Isabelle Plo
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Caroline Marty
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Leila N Varghese
- c Ludwig Institute for Cancer Research Brussels , Brussels , Belgium.,d de Duve Institute, Université catholique de Louvain , Brussels , Belgium
| | - Stefan N Constantinescu
- c Ludwig Institute for Cancer Research Brussels , Brussels , Belgium.,d de Duve Institute, Université catholique de Louvain , Brussels , Belgium.,e WELBIO (Walloon Excellence in Life Sciences and Biotechnology) , Brussels , Belgium
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28
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Floss DM, Scheller J. Naturally occurring and synthetic constitutive-active cytokine receptors in disease and therapy. Cytokine Growth Factor Rev 2019; 47:1-20. [PMID: 31147158 DOI: 10.1016/j.cytogfr.2019.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/15/2019] [Indexed: 02/07/2023]
Abstract
Cytokines control immune related events and are critically involved in a plethora of patho-physiological processes including autoimmunity and cancer development. Mutations which cause ligand-independent, constitutive activation of cytokine receptors are quite frequently found in diseases. Many constitutive-active cytokine receptor variants have been directly connected to disease development and mechanistically analyzed. Nature's solutions to generate constitutive cytokine receptors has been recently adopted by synthetic cytokine receptor biology, with the goal to optimize immune therapeutics. Here, CAR T cell immmunotherapy represents the first example to combine synthetic biology with genetic engineering during therapy. Hence, constitutive-active cytokine receptors are therapeutic targets, but also emerging tools to improve or modulate immunotherapeutic strategies. This review gives a comprehensive insight into the field of naturally occurring and synthetic constitutive-active cytokine receptors.
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Affiliation(s)
- Doreen M Floss
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Jürgen Scheller
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
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29
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Bousoik E, Montazeri Aliabadi H. "Do We Know Jack" About JAK? A Closer Look at JAK/STAT Signaling Pathway. Front Oncol 2018; 8:287. [PMID: 30109213 PMCID: PMC6079274 DOI: 10.3389/fonc.2018.00287] [Citation(s) in RCA: 237] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 07/09/2018] [Indexed: 12/14/2022] Open
Abstract
Janus tyrosine kinase (JAK) family of proteins have been identified as crucial proteins in signal transduction initiated by a wide range of membrane receptors. Among the proteins in this family JAK2 has been associated with important downstream proteins, including signal transducers and activators of transcription (STATs), which in turn regulate the expression of a variety of proteins involved in induction or prevention of apoptosis. Therefore, the JAK/STAT signaling axis plays a major role in the proliferation and survival of different cancer cells, and may even be involved in resistance mechanisms against molecularly targeted drugs. Despite extensive research focused on the protein structure and mechanisms of activation of JAKs, and signal transduction through these proteins, their importance in cancer initiation and progression seem to be underestimated. This manuscript is an attempt to highlight the role of JAK proteins in cancer biology, the most recent developments in targeting JAKs, and the central role they play in intracellular cross-talks with other signaling cascades.
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Affiliation(s)
- Emira Bousoik
- Department of Biomedical and Pharmaceutical Sciences, Center for Targeted Drug Delivery, School of Pharmacy, Chapman University, Irvine, CA, United States.,School of Pharmacy, Omar Al-Mukhtar University, Dèrna, Libya
| | - Hamidreza Montazeri Aliabadi
- Department of Biomedical and Pharmaceutical Sciences, Center for Targeted Drug Delivery, School of Pharmacy, Chapman University, Irvine, CA, United States
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30
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Singh K, Sazawal S, Chhikara S, Mahapatra M, Saxena R. Association of JAK2V617F mutation with thrombosis in Indian patients with Philadelphia negative chronic myeloproliferative neoplasms. INDIAN J PATHOL MICR 2018; 61:371-374. [PMID: 30004057 DOI: 10.4103/ijpm.ijpm_781_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background : It is still a matter of debate regarding the association of JAK2V617F mutation with thrombosis in BCR-ABL negative CMPN patients. The role of JAK2V617F mutation in increasing the thrombotic risk in CMPNs is yet unequivocal. Aims : To clarify the contribution of JAK2V617F mutation in thrombosis in CMPN patients. Settings and Design This retrospective study was done to evaluate role of JAK2V617F mutation in thrombosis in CMPNs. Materials and Methods 65 CMPN patients (PV, ET and PMF) were analyzed for JAK2V617F mutation using ARMS-PCR and detailed history of thrombosis was recorded in these patients. Statistical Analysis P values were 2 tailed, and statistical significance was set at P < 0.05. Results : 46/65 were males and 19/65 were females [M: F: 2.4:1] with median age 46 years [range, 14-80 years]. Patients had median Hb 15.6 g/dl [range, 5.1-20.3], median TLC 10.7 × 109/l [range 2.4-216] and platelet count 360 × 109/l [range, 20-1859]. 32 were JAK2V617F positive and 33 were negative for this mutation. On comparing the prevalence of thrombosis in JAK2V617F positive patients with JAK2V617F negative patients, we observed that 20/32 (62.5%) JAK2V617F positive patients had thrombosis as compared to 16/33 (48%) in JAK2V617F negative patients (P = 0.04). We observed significant association of JAK2V617F mutation with thrombosis, however no association of this mutation with thrombosis was observed among the JAK2V617F negative patients. Conclusion Our study suggests that JAK2V617F mutation may increase the risk of thrombosis in CMPNs. This finding could lead to risk stratification, setting up the treatment strategy in CMPNs.
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Affiliation(s)
- Kanwaljeet Singh
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
| | - Sudha Sazawal
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
| | - Sunita Chhikara
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
| | - Manoranjan Mahapatra
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
| | - Renu Saxena
- Department of Hematology, All India Institute of Medical Sciences, New Delhi, India
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31
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Vainchenker W, Leroy E, Gilles L, Marty C, Plo I, Constantinescu SN. JAK inhibitors for the treatment of myeloproliferative neoplasms and other disorders. F1000Res 2018; 7:82. [PMID: 29399328 PMCID: PMC5773931 DOI: 10.12688/f1000research.13167.1] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/11/2018] [Indexed: 01/04/2023] Open
Abstract
JAK inhibitors have been developed following the discovery of the
JAK2V617F in 2005 as the driver mutation of the majority of non-
BCR-ABL1 myeloproliferative neoplasms (MPNs). Subsequently, the search for JAK2 inhibitors continued with the discovery that the other driver mutations (
CALR and
MPL) also exhibited persistent JAK2 activation. Several type I ATP-competitive JAK inhibitors with different specificities were assessed in clinical trials and exhibited minimal hematologic toxicity. Interestingly, these JAK inhibitors display potent anti-inflammatory activity. Thus, JAK inhibitors targeting preferentially JAK1 and JAK3 have been developed to treat inflammation, autoimmune diseases, and graft-versus-host disease. Ten years after the beginning of clinical trials, only two drugs have been approved by the US Food and Drug Administration: one JAK2/JAK1 inhibitor (ruxolitinib) in intermediate-2 and high-risk myelofibrosis and hydroxyurea-resistant or -intolerant polycythemia vera and one JAK1/JAK3 inhibitor (tofacitinib) in methotrexate-resistant rheumatoid arthritis. The non-approved compounds exhibited many off-target effects leading to neurological and gastrointestinal toxicities, as seen in clinical trials for MPNs. Ruxolitinib is a well-tolerated drug with mostly anti-inflammatory properties. Despite a weak effect on the cause of the disease itself in MPNs, it improves the clinical state of patients and increases survival in myelofibrosis. This limited effect is related to the fact that ruxolitinib, like the other type I JAK2 inhibitors, inhibits equally mutated and wild-type JAK2 (JAK2WT) and also the JAK2 oncogenic activation. Thus, other approaches need to be developed and could be based on either (1) the development of new inhibitors specifically targeting
JAK2V617F or (2) the combination of the actual JAK2 inhibitors with other therapies, in particular with molecules targeting pathways downstream of JAK2 activation or the stability of JAK2 molecule. In contrast, the strong anti-inflammatory effects of the JAK inhibitors appear as a very promising therapeutic approach for many inflammatory and auto-immune diseases.
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Affiliation(s)
- William Vainchenker
- INSERM UMR 1170, Gustave Roussy, Villejuif, France.,Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France.,UMR 1170, Gustave Roussy, Villejuif, France
| | - Emilie Leroy
- Signal Transduction & Molecular Hematology Unit, Ludwig Institute for Cancer Research, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Laure Gilles
- Institut National de la Transfusion Sanguine, Paris, France
| | - Caroline Marty
- INSERM UMR 1170, Gustave Roussy, Villejuif, France.,Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France.,UMR 1170, Gustave Roussy, Villejuif, France
| | - Isabelle Plo
- INSERM UMR 1170, Gustave Roussy, Villejuif, France.,Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France.,UMR 1170, Gustave Roussy, Villejuif, France
| | - Stefan N Constantinescu
- Signal Transduction & Molecular Hematology Unit, Ludwig Institute for Cancer Research, Brussels, Belgium.,de Duve Institute, Université catholique de Louvain, Brussels, Belgium
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Rethinking JAK2 inhibition: towards novel strategies of more specific and versatile janus kinase inhibition. Leukemia 2017; 31:1023-1038. [DOI: 10.1038/leu.2017.43] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/16/2016] [Accepted: 01/10/2017] [Indexed: 12/19/2022]
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Varghese LN, Defour JP, Pecquet C, Constantinescu SN. The Thrombopoietin Receptor: Structural Basis of Traffic and Activation by Ligand, Mutations, Agonists, and Mutated Calreticulin. Front Endocrinol (Lausanne) 2017; 8:59. [PMID: 28408900 PMCID: PMC5374145 DOI: 10.3389/fendo.2017.00059] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/17/2017] [Indexed: 12/13/2022] Open
Abstract
A well-functioning hematopoietic system requires a certain robustness and flexibility to maintain appropriate quantities of functional mature blood cells, such as red blood cells and platelets. This review focuses on the cytokine receptor that plays a significant role in thrombopoiesis: the receptor for thrombopoietin (TPO-R; also known as MPL). Here, we survey the work to date to understand how this receptor functions at a molecular level throughout its lifecycle, from traffic to the cell surface, dimerization and binding cognate cytokine via its extracellular domain, through to its subsequent activation of associated Janus kinases and initiation of downstream signaling pathways, as well as the regulation of these processes. Atomic level resolution structures of TPO-R have remained elusive. The identification of disease-causing mutations in the receptor has, however, offered some insight into structure and function relationships, as has artificial means of receptor activation, through TPO mimetics, transmembrane-targeting receptor agonists, and engineering in dimerization domains. More recently, a novel activation mechanism was identified whereby mutated forms of calreticulin form complexes with TPO-R via its extracellular N-glycosylated domain. Such complexes traffic pathologically in the cell and persistently activate JAK2, downstream signal transducers and activators of transcription (STATs), and other pathways. This pathologic TPO-R activation is associated with a large fraction of human myeloproliferative neoplasms.
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Affiliation(s)
- Leila N. Varghese
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Philippe Defour
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- Department of Clinical Biology, Cliniques universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Christian Pecquet
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Stefan N. Constantinescu
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- *Correspondence: Stefan N. Constantinescu,
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Plo I, Bellanné-Chantelot C, Mosca M, Mazzi S, Marty C, Vainchenker W. Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis. Front Endocrinol (Lausanne) 2017; 8:234. [PMID: 28955303 PMCID: PMC5600916 DOI: 10.3389/fendo.2017.00234] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/28/2017] [Indexed: 12/31/2022] Open
Abstract
Megakaryopoiesis is an original and complex cell process which leads to the formation of platelets. The homeostatic production of platelets is mainly regulated and controlled by thrombopoietin (TPO) and the TPO receptor (MPL)/JAK2 axis. Therefore, any hereditary or acquired abnormality affecting this signaling axis can result in thrombocytosis or thrombocytopenia. Thrombocytosis can be due to genetic alterations that affect either the intrinsic MPL signaling through gain-of-function (GOF) activity (MPL, JAK2, CALR) and loss-of-function (LOF) activity of negative regulators (CBL, LNK) or the extrinsic MPL signaling by THPO GOF mutations leading to increased TPO synthesis. Alternatively, thrombocytosis may paradoxically result from mutations of MPL leading to an abnormal MPL trafficking, inducing increased TPO levels by alteration of its clearance. In contrast, thrombocytopenia can also result from LOF THPO or MPL mutations, which cause a complete defect in MPL trafficking to the cell membrane, impaired MPL signaling or stability, defects in the TPO/MPL interaction, or an absence of TPO production.
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Affiliation(s)
- Isabelle Plo
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Christine Bellanné-Chantelot
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Department of Genetics, AP-HP Hôpitaux Universitaires Pitié Salpêtrière - Charles Foix, UPMC Univ Paris 06, Paris, France
| | - Matthieu Mosca
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Stefania Mazzi
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Diderot, Paris, France
| | - Caroline Marty
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - William Vainchenker
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
- *Correspondence: William Vainchenker,
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An incomplete trafficking defect to the cell-surface leads to paradoxical thrombocytosis for human and murine MPL P106L. Blood 2016; 128:3146-3158. [PMID: 28034873 DOI: 10.1182/blood-2016-06-722058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 11/03/2016] [Indexed: 12/30/2022] Open
Abstract
The mechanisms behind the hereditary thrombocytosis induced by the thrombopoietin (THPO) receptor MPL P106L mutant remain unknown. A complete trafficking defect to the cell surface has been reported, suggesting either weak constitutive activity or nonconventional THPO-dependent mechanisms. Here, we report that the thrombocytosis phenotype induced by MPL P106L belongs to the paradoxical group, where low MPL levels on platelets and mature megakaryocytes (MKs) lead to high serum THPO levels, whereas weak but not absent MPL cell-surface localization in earlier MK progenitors allows response to THPO by signaling and amplification of the platelet lineage. MK progenitors from patients showed no spontaneous growth and responded to THPO, and MKs expressed MPL on their cell surface at low levels, whereas their platelets did not respond to THPO. Transduction of MPL P106L in CD34+ cells showed that this receptor was more efficiently localized at the cell surface on immature than on mature MKs, explaining a proliferative response to THPO of immature cells and a defect in THPO clearance in mature cells. In a retroviral mouse model performed in Mpl-/- mice, MPL P106L could induce a thrombocytosis phenotype with high circulating THPO levels. Furthermore, we could select THPO-dependent cell lines with more cell-surface MPL P106L localization that was detected by flow cytometry and [125I]-THPO binding. Altogether, these results demonstrate that MPL P106L is a receptor with an incomplete defect in trafficking, which induces a low but not absent localization of the receptor on cell surface and a response to THPO in immature MK cells.
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McNally R, Toms AV, Eck MJ. Crystal Structure of the FERM-SH2 Module of Human Jak2. PLoS One 2016; 11:e0156218. [PMID: 27227461 PMCID: PMC4881981 DOI: 10.1371/journal.pone.0156218] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 04/13/2016] [Indexed: 01/18/2023] Open
Abstract
Jak-family tyrosine kinases mediate signaling from diverse cytokine receptors. Binding of Jaks to their cognate receptors is mediated by their N-terminal region, which contains FERM and SH2 domains. Here we describe the crystal structure of the FERM-SH2 region of Jak2 at 3.0Å resolution. The structure reveals that these domains and their flanking linker segments interact intimately to form an integrated structural module. The Jak2 FERM-SH2 structure closely resembles that recently described for Tyk2, another member of the Jak family. While the overall architecture and interdomain orientations are preserved between Jak2 and Tyk2, we identify residues in the putative receptor-binding groove that differ between the two and may contribute to the specificity of receptor recognition. Analysis of Jak mutations that are reported to disrupt receptor binding reveals that they lie in the hydrophobic core of the FERM domain, and are thus expected to compromise the structural integrity of the FERM-SH2 unit. Similarly, analysis of mutations in Jak3 that are associated with severe combined immunodeficiency suggests that they compromise Jak3 function by destabilizing the FERM-SH2 structure.
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Affiliation(s)
- Randall McNally
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Angela V. Toms
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael J. Eck
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Ferrao R, Wallweber HJA, Ho H, Tam C, Franke Y, Quinn J, Lupardus PJ. The Structural Basis for Class II Cytokine Receptor Recognition by JAK1. Structure 2016; 24:897-905. [PMID: 27133025 DOI: 10.1016/j.str.2016.03.023] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 03/14/2016] [Accepted: 03/19/2016] [Indexed: 01/06/2023]
Abstract
JAK1 is a member of the Janus kinase (JAK) family of non-receptor tyrosine kinases that are activated in response to cytokines and interferons. Here, we present two crystal structures of the human JAK1 FERM and SH2 domains bound to peptides derived from the class II cytokine receptors IFN-λ receptor 1 and IL-10 receptor 1 (IFNLR1 and IL10RA). These structures reveal an interaction site in the JAK1 FERM that accommodates the so-called "box1" membrane-proximal receptor peptide motif. Biophysical analysis of the JAK1-IFNLR1 interaction indicates that the receptor box1 is the primary driver of the JAK1 interaction, and identifies residues conserved among class II receptors as important for binding. In addition, we demonstrate that a second "box2" receptor motif further stabilizes the JAK1-IFNLR1 complex. Together, these data identify a conserved JAK binding site for receptor peptides and elucidate the mechanism by which class II cytokine receptors interact with JAK1.
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Affiliation(s)
- Ryan Ferrao
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Heidi J A Wallweber
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Hoangdung Ho
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Christine Tam
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Yvonne Franke
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - John Quinn
- Department of Biochemical and Cellular Pharmacology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
| | - Patrick J Lupardus
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
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Thrombopoietin receptor activation by myeloproliferative neoplasm associated calreticulin mutants. Blood 2016; 127:1325-35. [DOI: 10.1182/blood-2015-11-681932] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 12/07/2015] [Indexed: 02/03/2023] Open
Abstract
Key Points
Calreticulin mutants responsible for myeloproliferative neoplasms specifically activate the thrombopoietin receptor and in turn JAK2. Activation of the thrombopoietin receptor requires the glycan binding site and a novel C-terminal tail of the mutant calreticulin.
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40
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Nespital T, van der Velden LM, Mensinga A, van der Vaart ED, Strous GJ. Fos-Zippered GH Receptor Cytosolic Tails Act as Jak2 Substrates and Signal Transducers. Mol Endocrinol 2016; 30:290-301. [PMID: 26859362 DOI: 10.1210/me.2015-1315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Members of the Janus kinase (Jak) family initiate the majority of downstream signaling events of the cytokine receptor family. The prevailing principle is that the receptors act in dimers: 2 Jak2 molecules bind to the cytosolic tails of a cytokine receptor family member and initiate Jak-signal transducer and activator of transcription signaling upon a conformational change in the receptor complex, induced by the cognate cytokine. Due to the complexity of signaling complexes, there is a strong need for in vitro model systems. To investigate the molecular details of the Jak2 interaction with the GH receptor (GHR), we used cytosolic tails provided with leucine zippers derived from c-Fos to mimic the dimerized state of GHR. Expressed together with Jak2, fos-zippered tails, but not unzippered tails, were stabilized. In addition, the Jak-signal transducer and activator of transcription signaling pathway was activated by the fos-zippered tails. The stabilization depended also on α-helix rotation of the zippers. Fos-zippered GHR tails and Jak2, both purified from baculovirus-infected insect cells, interacted via box1 with a binding affinity of approximately 40nM. As expected, the Jak kinase inhibitor Ruxolitinib inhibited the stabilization but did not affect the c-Fos-zippered GHR tail-Jak2 interaction. Analysis by blue-native gel electrophoresis revealed high molecular-weight complexes containing both Jak2 and nonphosphorylated GHR tails, whereas Jak2-dissociated tails were highly phosphorylated and monomeric, implying that Jak2 detaches from its substrate upon phosphorylation.
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Affiliation(s)
- Tobias Nespital
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Lieke M van der Velden
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Anneloes Mensinga
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Elisabeth D van der Vaart
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Ger J Strous
- Department of Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
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Alshemmari SH, Rajan R, Emadi A. Molecular Pathogenesis and Clinical Significance of Driver Mutations in Primary Myelofibrosis: A Review. Med Princ Pract 2016; 25:501-509. [PMID: 27756071 PMCID: PMC5588514 DOI: 10.1159/000450956] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 09/21/2016] [Indexed: 12/12/2022] Open
Abstract
Primary myelofibrosis (PMF) is a rare chronic BCR-ABL1-negative myeloproliferative neoplasm characterized by progressive bone marrow fibrosis, inefficient hematopoiesis, and shortened survival. The clinical manifestations of PMF include splenomegaly, consequent to extramedullary hematopoiesis, pancytopenias, and an array of potentially debilitating constitutional symptoms. The diagnosis is based on bone marrow morphology and clinical criteria. Mutations in the JAK2 (V617F), MPL (W515), and CALR (exon 9 indel) genes are found in approximately 90% of patients whereas the remaining 10% are so-called triple negatives. Activation of the JAK/STAT pathway results in overproduction of abnormal megakaryocytes leading to bone marrow fibrosis. These mutations might be accompanied by other mutations, such as ASXL1. The commonly used prognostication scoring for PMF is based on the International Prognostic Scoring System. The subsequently developed Dynamic International Prognostic Scoring System-plus employs clinical as well as cytogenetic variables. In PMF, CALR mutation is associated with superior survival and ASXL1 with inferior outcome. Patients with triple-negative PMF have a higher incidence of leukemic transformation and lower overall survival compared with CALR- or JAK2-mutant patients. The impact of genetic lesions on survival is independent of current prognostic scoring systems. These observations indicate that driver and passenger mutations define distinct disease entities within PMF. Accounting for them is not only relevant to clinical decision-making, but should also be considered in designing clinical trials.
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Affiliation(s)
- Salem H. Alshemmari
- Department of Medicine, Faculty of Medicine, Kuwait University, Md., USA
- *Salem H. Alshemmari, MD, Department of Medicine, Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110 (Kuwait), E-Mail
| | - Reshmi Rajan
- Stem Cell and Bone Marrow Transplant Laboratory, Kuwait Cancer Center, Safat, Kuwait
| | - Ashkan Emadi
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Md., USA
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Leroy E, Defour JP, Sato T, Dass S, Gryshkova V, Shwe MM, Staerk J, Constantinescu SN, Smith SO. His499 Regulates Dimerization and Prevents Oncogenic Activation by Asparagine Mutations of the Human Thrombopoietin Receptor. J Biol Chem 2015; 291:2974-87. [PMID: 26627830 DOI: 10.1074/jbc.m115.696534] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Indexed: 01/18/2023] Open
Abstract
Ligand binding to the extracellular domain of the thrombopoietin receptor (TpoR) imparts a specific orientation on the transmembrane (TM) and intracellular domains of the receptors that is required for physiologic activation via receptor dimerization. To map the inactive and active dimeric orientations of the TM helices, we performed asparagine (Asn)-scanning mutagenesis of the TM domains of the murine and human TpoR. Substitution of Asn at only one position (S505N) activated the human receptor, whereas Asn substitutions at several positions activated the murine receptor. Second site mutational studies indicate that His(499) near the N terminus of the TM domain is responsible for protecting the human receptor from activation by Asn mutations. Structural studies reveal that the sequence preceding His(499) is helical in the murine receptor but non-helical in peptides corresponding to the TM domain of the inactive human receptor. The activating S505N mutation and the small molecule agonist eltrombopag both induce helix in this region of the TM domain and are associated with dimerization and activation of the human receptor. Thus, His(499) regulates the activation of human TpoR and provides additional protection against activating mutations, such as oncogenic Asn mutations in the TM domain.
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Affiliation(s)
- Emilie Leroy
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Jean-Philippe Defour
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Takeshi Sato
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Sharmila Dass
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215, and
| | - Vitalina Gryshkova
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Myat M Shwe
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Judith Staerk
- Stem Cell Group, Nordic European Molecular Biology Laboratory Partnership and Center for Molecular Medicine, 0318 Oslo, Norway
| | - Stefan N Constantinescu
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium,
| | - Steven O Smith
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215, and
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Springuel L, Renauld JC, Knoops L. JAK kinase targeting in hematologic malignancies: a sinuous pathway from identification of genetic alterations towards clinical indications. Haematologica 2015; 100:1240-53. [PMID: 26432382 PMCID: PMC4591756 DOI: 10.3324/haematol.2015.132142] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/17/2015] [Indexed: 12/16/2022] Open
Abstract
Constitutive JAK-STAT pathway activation occurs in most myeloproliferative neoplasms as well as in a significant proportion of other hematologic malignancies, and is frequently a marker of poor prognosis. The underlying molecular alterations are heterogeneous as they include activating mutations in distinct components (cytokine receptor, JAK, STAT), overexpression (cytokine receptor, JAK) or rare JAK2 fusion proteins. In some cases, concomitant loss of negative regulators contributes to pathogenesis by further boosting the activation of the cascade. Exploiting the signaling bottleneck provided by the limited number of JAK kinases is an attractive therapeutic strategy for hematologic neoplasms driven by constitutive JAK-STAT pathway activation. However, given the conserved nature of the kinase domain among family members and the interrelated roles of JAK kinases in many physiological processes, including hematopoiesis and immunity, broad usage of JAK inhibitors in hematology is challenged by their narrow therapeutic window. Novel therapies are, therefore, needed. The development of more selective inhibitors is a questionable strategy as such inhibitors might abrogate the beneficial contribution of alleviating the cancer-related pro-inflammatory microenvironment and raise selective pressure to a threshold that allows the emergence of malignant subclones harboring drug-resistant mutations. In contrast, synergistic combinations of JAK inhibitors with drugs targeting cascades that work in concert with JAK-STAT pathway appear to be promising therapeutic alternatives to JAK inhibitors as monotherapies.
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Affiliation(s)
- Lorraine Springuel
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium
| | - Jean-Christophe Renauld
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium
| | - Laurent Knoops
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium Hematology Unit, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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44
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Lipocalin produced by myelofibrosis cells affects the fate of both hematopoietic and marrow microenvironmental cells. Blood 2015; 126:972-82. [PMID: 26022238 DOI: 10.1182/blood-2014-12-618595] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/18/2015] [Indexed: 12/20/2022] Open
Abstract
Myelofibrosis (MF) is characterized by cytopenias, constitutional symptoms, splenomegaly, and marrow histopathological abnormalities (fibrosis, increased microvessel density, and osteosclerosis). The microenvironmental abnormalities are likely a consequence of the elaboration of a variety of inflammatory cytokines generated by malignant megakaryocytes and monocytes. We observed that levels of a specific inflammatory cytokine, lipocalin-2 (LCN2), were elevated in the plasmas of patients with myeloproliferative neoplasms (MF > polycythemia vera or essential thrombocythemia) and that LCN2 was elaborated by MF myeloid cells. LCN2 generates increased reactive oxygen species, leading to increased DNA strand breaks and apoptosis of normal, but not MF, CD34(+) cells. Furthermore, incubation of marrow adherent cells or mesenchymal stem cells with LCN2 increased the generation of osteoblasts and fibroblasts, but not adipocytes. LCN2 priming of mesenchymal stem cells resulted in the upregulation of RUNX2 gene as well as other genes that are capable of further affecting osteoblastogenesis, angiogenesis, and the deposition of matrix proteins. These data indicate that LCN2 is an additional MF inflammatory cytokine that likely contributes to the creation of a cascade of events that results in not only a predominance of the MF clone but also a dysfunctional microenvironment.
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Abstract
Dynamins are highly conserved large GTPases (enzymes that hydrolyze guanosine triphosphate) involved in endocytosis and vesicle transport, and mutations in the ubiquitous and housekeeping dynamin 2 (DNM2) have been associated with thrombocytopenia in humans. To determine the role of DNM2 in thrombopoiesis, we generated Dnm2(fl/fl) Pf4-Cre mice specifically lacking DNM2 in the megakaryocyte (MK) lineage. Dnm2(fl/fl) Pf4-Cre mice had severe macrothrombocytopenia with moderately accelerated platelet clearance. Dnm2-null bone marrow MKs had altered demarcation membrane system formation in vivo due to defective endocytic pathway, and fetal liver-derived Dnm2-null MKs formed proplatelets poorly in vitro, showing that DNM2-dependent endocytosis plays a major role in MK membrane formation and thrombopoiesis. Endocytosis of the thrombopoietin receptor Mpl was impaired in Dnm2-null platelets, causing constitutive phosphorylation of the tyrosine kinase JAK2 and elevated circulating thrombopoietin levels. MK-specific DNM2 deletion severely disrupted bone marrow homeostasis, as reflected by marked expansion of hematopoietic stem and progenitor cells, MK hyperplasia, myelofibrosis, and consequent extramedullary hematopoiesis and splenomegaly. Taken together, our data demonstrate that unrestrained MK growth and proliferation results in rapid myelofibrosis and establishes a previously unrecognized role for DNM2-dependent endocytosis in megakaryopoiesis, thrombopoiesis, and bone marrow homeostasis.
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46
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Carbone CJ, Fuchs SY. Eliminative signaling by Janus kinases: role in the downregulation of associated receptors. J Cell Biochem 2014; 115:8-16. [PMID: 23959845 DOI: 10.1002/jcb.24647] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 07/31/2013] [Indexed: 12/11/2022]
Abstract
Activation of cytokine receptor-associated Janus kinases (JAKs) mediates most, if not all, of the cellular responses to peptide hormones and cytokines. Consequently, JAKs play a paramount role in homeostasis and immunity. Members of this family of tyrosine kinases control the cytokine/hormone-induced alterations in cell gene expression program. This function is largely mediated through an ability to signal toward activation of the signal transducer and activator of transcription proteins (STAT), as well as toward some other pathways. Importantly, JAKs are also instrumental in tightly controlling the expression of associated cytokine and hormone receptors, and, accordingly, in regulating the cell sensitivity to these cytokines and hormones. This review highlights the enzymatic and non-enzymatic mechanisms of this regulation and discusses the importance of the ambidextrous nature of JAK as a key signaling node that integrates the combining functions of forward signaling and eliminative signaling. Attention to the latter aspect of JAK function may contribute to emancipating our approaches to the pharmacological modulation of JAKs.
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Affiliation(s)
- Christopher J Carbone
- Department of Animal Biology and Mari Lowe Center for Comparative Oncology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
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Cleyrat C, Darehshouri A, Steinkamp MP, Vilaine M, Boassa D, Ellisman MH, Hermouet S, Wilson BS. Mpl traffics to the cell surface through conventional and unconventional routes. Traffic 2014; 15:961-82. [PMID: 24931576 PMCID: PMC4141020 DOI: 10.1111/tra.12185] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 12/20/2022]
Abstract
Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin (CALR) mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: human erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the endoplasmic reticulum (ER). Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially colocalize with ER-tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling.
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Affiliation(s)
- Cédric Cleyrat
- Department of Pathology & Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131 USA
- INSERM UMR892/CNRS UMR6299, Centre de Recherche en Cancérologie Nantes-Angers (CRCNA), Institut de Recherche Thérapeutique-Université de Nantes, Nantes, France
| | - Anza Darehshouri
- Department of Pathology & Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131 USA
| | - Mara P. Steinkamp
- Department of Pathology & Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131 USA
| | - Mathias Vilaine
- INSERM UMR892/CNRS UMR6299, Centre de Recherche en Cancérologie Nantes-Angers (CRCNA), Institut de Recherche Thérapeutique-Université de Nantes, Nantes, France
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, University of California at San Diego, San Diego CA 92093 USA
| | - Mark H. Ellisman
- National Center for Microscopy and Imaging Research, University of California at San Diego, San Diego CA 92093 USA
| | - Sylvie Hermouet
- INSERM UMR892/CNRS UMR6299, Centre de Recherche en Cancérologie Nantes-Angers (CRCNA), Institut de Recherche Thérapeutique-Université de Nantes, Nantes, France
| | - Bridget S. Wilson
- Department of Pathology & Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, NM, 87131 USA
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JAK2 and MPL protein levels determine TPO-induced megakaryocyte proliferation vs differentiation. Blood 2014; 124:2104-15. [PMID: 25143485 DOI: 10.1182/blood-2014-03-559815] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Megakaryopoiesis is a 2-step differentiation process, regulated by thrombopoietin (TPO), on binding to its cognate receptor myeloproliferative leukemia (MPL). This receptor associates with intracytoplasmic tyrosine kinases, essentially janus kinase 2 (JAK2), which regulates MPL stability and cell-surface expression, and mediates TPO-induced signal transduction. We demonstrate that JAK2 and MPL mediate TPO-induced proliferation arrest and megakaryocytic differentiation of the human megakaryoblastic leukemia cell line UT7-MPL. A decrease in JAK2 or MPL protein expression, and JAK2 chemical inhibition, suppress this antiproliferative action of TPO. The expression of JAK2 and MPL, which progressively increases along normal human megakaryopoiesis, is decreased in platelets of patients diagnosed with JAK2- or MPL-mutated essential thrombocytemia and primary myelofibrosis, 2 myeloproliferative neoplasms in which megakaryocytes (MKs) proliferate excessively. Finally, low doses of JAK2 chemical inhibitors are shown to induce a paradoxical increase in MK production, both in vitro and in vivo. We propose that JAK2 and MPL expression levels regulate megakaryocytic proliferation vs differentiation in both normal and pathological conditions, and that JAK2 chemical inhibitors could promote a paradoxical thrombocytosis when used at suboptimal doses.
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Wallweber HJA, Tam C, Franke Y, Starovasnik MA, Lupardus PJ. Structural basis of recognition of interferon-α receptor by tyrosine kinase 2. Nat Struct Mol Biol 2014; 21:443-8. [PMID: 24704786 PMCID: PMC4161281 DOI: 10.1038/nsmb.2807] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 03/03/2014] [Indexed: 12/25/2022]
Abstract
Tyrosine kinase 2 (TYK2) is a member of the Janus kinase (JAK) family of non-receptor tyrosine kinases, which are essential for proper signaling in immune responses and development. Here we present a 2.0 angstrom resolution crystal structure of a receptor-binding fragment of human TYK2 encompassing the FERM and SH2 domains in complex with a so-called “box2” containing intracellular peptide motif from the IFNα receptor (IFNAR1). The TYK2–IFNAR1 interface reveals an unexpected receptor-binding mode that mimics a SH2 domain–phosphopeptide interaction, with a glutamate replacing the canonical phosphotyrosine residue. This structure provides the first view to our knowledge of a JAK in complex with its cognate receptor and defines the molecular logic through which JAKs evolved to interact with divergent receptor sequences.
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Affiliation(s)
- Heidi J A Wallweber
- Department of Structural Biology, Genentech, South San Francisco, California, USA
| | - Christine Tam
- Department of Structural Biology, Genentech, South San Francisco, California, USA
| | - Yvonne Franke
- Department of Structural Biology, Genentech, South San Francisco, California, USA
| | | | - Patrick J Lupardus
- Department of Structural Biology, Genentech, South San Francisco, California, USA
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Rinis N, Küster A, Schmitz-Van de Leur H, Mohr A, Müller-Newen G. Intracellular signaling prevents effective blockade of oncogenic gp130 mutants by neutralizing antibodies. Cell Commun Signal 2014; 12:14. [PMID: 24612692 PMCID: PMC4007646 DOI: 10.1186/1478-811x-12-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 02/24/2014] [Indexed: 12/26/2022] Open
Abstract
Background Short in-frame deletions in the second extracellular domain of the cytokine receptor gp130 are the leading cause of inflammatory hepatocellular adenomas (IHCAs). The deletions render gp130 constitutively active. In this study we investigate the intracellular signaling potential of one of the most potent constitutively active gp130 mutants (CAgp130) found in IHCAs. Results Trafficking and signaling of CAgp130 were studied in stably transfected cell lines that allowed the inducible expression of CAgp130 fused to fluorescent proteins such as YFP and mCherry. In contrast to the predominantly highly glycosylated gp130 wild type (WTgp130), CAgp130 is preferentially found in the less glycosylated high-mannose form. Accordingly, the mutated receptor is retained intracellularly and therefore less prominently expressed at the cell surface. CAgp130 persistently activates Stat3 despite the presence of the feedback inhibitor SOCS3 but fails to activate Erk1/2. De novo synthesized CAgp130 signals already from the ER-Golgi compartment before having reached the plasma membrane. Cell surface expressed and endocytosed CAgp130 do not significantly contribute to signaling. As a consequence, Stat3 activation through CAgp130 cannot be inhibited by neutralizing gp130 antibodies but through overexpression of a dominant-negative Stat3 mutant. Conclusion CAgp130 and WTgp130 differ significantly with respect to glycosylation, trafficking and signaling. As a consequence of intracellular signaling pharmacological inhibition of CAgp130 will not be achieved by targeting the receptor extracellularly but by compounds that act from within the cell.
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Affiliation(s)
| | | | | | | | - Gerhard Müller-Newen
- Institute of Biochemistry and Molecular Biology, RWTH Aachen University, Pauwelsstraße 30, Aachen 52074, Germany.
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