51
|
VDAC2 enables BAX to mediate apoptosis and limit tumor development. Nat Commun 2018; 9:4976. [PMID: 30478310 PMCID: PMC6255874 DOI: 10.1038/s41467-018-07309-4] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Intrinsic apoptosis is critical to prevent tumor formation and is engaged by many anti-cancer agents to eliminate tumor cells. BAX and BAK, the two essential mediators of apoptosis, are thought to be regulated through similar mechanisms and act redundantly to drive apoptotic cell death. From an unbiased genome-wide CRISPR/Cas9 screen, we identified VDAC2 (voltage-dependent anion channel 2) as important for BAX, but not BAK, to function. Genetic deletion of VDAC2 abrogated the association of BAX and BAK with mitochondrial complexes containing VDAC1, VDAC2, and VDAC3, but only inhibited BAX apoptotic function. Deleting VDAC2 phenocopied the loss of BAX in impairing both the killing of tumor cells by anti-cancer agents and the ability to suppress tumor formation. Together, our studies show that efficient BAX-mediated apoptosis depends on VDAC2, and reveal a striking difference in how BAX and BAK are functionally impacted by their interactions with VDAC2.
Collapse
|
52
|
Ya F, Tian J, Li Q, Chen L, Ren J, Zhao Y, Wan J, Ling W, Yang Y. Cyanidin-3-O-β-glucoside, a Natural Polyphenol, Exerts Proapoptotic Effects on Activated Platelets and Enhances Megakaryocytic Proplatelet Formation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:10712-10720. [PMID: 30226049 DOI: 10.1021/acs.jafc.8b03266] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This study investigated whether the anthocyanin cyanidin-3-O-β-glucoside (Cy-3-g) could affect platelet apoptosis and proplatelet formation in vitro. Thrombin-stimulated or resting human platelets and Meg-01 megakaryocytes were incubated with Cy-3-g (0, 0.5, 5, or 50 μM). We found that the percentage of the platelet mitochondrial membrane potential treated with 5 and 50 μM Cy-3-g was significantly higher than control (15.50% ± 3.24% and 29.77% ± 4.06% versus 2.76% ± 1.33%, respectively; P < 0.05). Treatment with 5 and 50 μM Cy-3-g significantly increased phosphatidylserine exposure compared with control (40.56% ± 10.53% and 76.62% ± 8.28% versus 15.43% ± 3.93%, respectively; P < 0.05). Moreover, Cy-3-g significantly increased the expression of Bax, Bak, and cytochrome c while markedly decreasing Bcl-xL and Bcl-2 expression as well as stimulating caspase-3, caspase-9, caspase-8, Bid, and gelsolin cleavage in thrombin-activated platelets in a dose-dependent manner ( P < 0.05). However, no significant differences were observed in the apoptosis of resting platelets when treated with Cy-3-g ( P > 0.05). Furthermore, Cy-3-g significantly ( P < 0.05) enhanced cell viability (50 μM versus control, 1.34 ± 0.01 versus 0.35 ± 0.02), the number of colony-forming unit-megakaryocytes (50 μM versus control, 38 ± 3 versus 8 ± 3), CD41 expression (50 μM versus control, 96.80% ± 2.55% versus 25.57% ± 2.86%), DNA ploidy (16N) (50 μM versus control, 19.73% ± 2.34% versus 4.42% ± 1.96%), and proplatelet formation (50 μM versus control, 27.5% ± 3.77% versus 7.67% ± 2.25%) in Meg-01 cells. In conclusion, Cy-3-g promotes activated platelet apoptosis and enhances megakaryocyte proliferation, differentiation, and proplatelet formation in vitro.
Collapse
Affiliation(s)
- Fuli Ya
- Department of Nutrition, School of Public Health , Sun Yat-sen University , Guangzhou , Guangdong Province 510080 , China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health , Guangzhou , Guangdong Province 510080 , China
- Guangdong Engineering Technology Research Center of Nutrition Translation , Guangzhou , Guangdong Province 510080 , China
| | - Jinju Tian
- Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences , Sun Yat-sen University , Guangzhou , Guangdong Province 510006 , China
| | - Qing Li
- Department of Nutrition, School of Public Health , Sun Yat-sen University , Guangzhou , Guangdong Province 510080 , China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health , Guangzhou , Guangdong Province 510080 , China
- Guangdong Engineering Technology Research Center of Nutrition Translation , Guangzhou , Guangdong Province 510080 , China
| | - Liyi Chen
- Department of Gynecology and Obstetrics, Bao'an Maternal and Child Health Hospital , Jinan University , Shenzhen 518101 , China
| | - Jing Ren
- Baoji Center For Disease Control and Prevention , Baoji , Shaanxi Province 721006 , China
| | - Yimin Zhao
- School of Public Health (Shenzhen) , Sun Yat-sen University , Guangzhou , Guangdong Province 510006 , China
| | - Jianbo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences , University of Macau , Taipa , Macao 999078 , China
| | - Wenhua Ling
- Department of Nutrition, School of Public Health , Sun Yat-sen University , Guangzhou , Guangdong Province 510080 , China
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health , Guangzhou , Guangdong Province 510080 , China
- Guangdong Engineering Technology Research Center of Nutrition Translation , Guangzhou , Guangdong Province 510080 , China
| | - Yan Yang
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health , Guangzhou , Guangdong Province 510080 , China
- Guangdong Engineering Technology Research Center of Nutrition Translation , Guangzhou , Guangdong Province 510080 , China
- School of Public Health (Shenzhen) , Sun Yat-sen University , Guangzhou , Guangdong Province 510006 , China
| |
Collapse
|
53
|
Luff SA, Kao CY, Papoutsakis ET. Role of p53 and transcription-independent p53-induced apoptosis in shear-stimulated megakaryocytic maturation, particle generation, and platelet biogenesis. PLoS One 2018; 13:e0203991. [PMID: 30231080 PMCID: PMC6145578 DOI: 10.1371/journal.pone.0203991] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/02/2018] [Indexed: 12/18/2022] Open
Abstract
Megakaryocytes (Mks) derive from hematopoietic stem and progenitor cells (HSPCs) in the bone marrow and develop into large, polyploid cells that eventually give rise to platelets. As Mks mature, they migrate from the bone marrow niche into the vasculature, where they are exposed to shear forces from blood flow, releasing Mk particles (platelet-like particles (PLPs), pro/preplatelets (PPTs), and Mk microparticles (MkMPs)) into circulation. We have previously shown that transcription factor p53 is important in Mk maturation, and that physiological levels of shear promote Mk particle generation and platelet biogenesis. Here we examine the role of p53 in the Mk shear-stress response. We show that p53 is acetylated in response to shear in both immature and mature Mks, and that decreased expression of deacetylase HDAC1, and increased expression of the acetyltransferases p300 and PCAF might be responsible for these changes. We also examined the hypothesis that p53 might be involved in the shear-induced Caspase 3 activation, phosphatidylserine (PS) externalization, and increased biogenesis of PLPs, PPTs, and MkMPs. We show that p53 is involved in all these shear-induced processes. We show that in response to shear, acetyl-p53 binds Bax, cytochrome c is released from mitochondria, and Caspase 9 is activated. We also show that shear-stimulated Caspase 9 activation and Mk particle biogenesis depend on transcription-independent p53-induced apoptosis (TIPA), but PS externalization is not. This is the first report to show that shear flow stimulates TIPA and that Caspase 9 activation and Mk-particle biogenesis are directly modulated by TIPA.
Collapse
Affiliation(s)
- Stephanie A. Luff
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
| | - Chen-Yuan Kao
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Eleftherios T. Papoutsakis
- Department of Biological Sciences, University of Delaware, Newark, Delaware, United States of America
- Delaware Biotechnology Institute, University of Delaware, Newark, Delaware, United States of America
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware, United States of America
| |
Collapse
|
54
|
Xie C, Zhao H, Bao X, Fu H, Lou L. Pharmacological characterization of hetrombopag, a novel orally active human thrombopoietin receptor agonist. J Cell Mol Med 2018; 22:5367-5377. [PMID: 30156363 PMCID: PMC6201220 DOI: 10.1111/jcmm.13809] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/29/2018] [Indexed: 01/07/2023] Open
Abstract
Nonpeptide thrombopoietin receptor (TPOR/MPL) agonists, such as eltrombopag, have been used to treat thrombocytopenia of various aetiologies. Here, we investigated the pharmacological properties of hetrombopag, a new orally active small‐molecule TPOR agonist, in preclinical models. Hetrombopag specifically stimulated proliferation and/or differentiation of human TPOR‐expressing cells, including 32D‐MPL and human hematopoietic stem cells, with low nanomolar EC50 values through stimulation of STAT, PI3K and ERK signalling pathways. Notably, hetrombopag effectively up‐regulated G1‐phase–related proteins, including p‐RB, Cyclin D1 and CDK4/6, normalized progression of the cell cycle, and prevented apoptosis by modulating BCL‐XL/BAK expression in 32D‐MPL cells. Moreover, hetrombopag and TPO acted additively in stimulating TPOR‐dependent signalling, promoting cell viability, and preventing apoptosis. Orally administered hetrombopag specifically promoted the viability and growth of 32D‐MPL cells in hollow fibres implanted into nude mice with much higher potency than that of the well‐known TPOR agonist, eltrombopag, in association with activation of TPOR‐dependent signal transduction in vivo. Taken together, our findings indicate that, given its favourable pharmacological characteristics, hetrombopag may represent a new, orally active, small‐molecule TPOR agonist for patients with thrombocytopenia.
Collapse
Affiliation(s)
- Chengying Xie
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Huajun Zhao
- College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Xubin Bao
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Haoyu Fu
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Liguang Lou
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| |
Collapse
|
55
|
Hypertonicity-imposed BCL-XL addiction primes colorectal cancer cells for death. Cancer Lett 2018; 435:23-31. [PMID: 30075205 DOI: 10.1016/j.canlet.2018.07.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 06/29/2018] [Accepted: 07/26/2018] [Indexed: 01/10/2023]
Abstract
Induction of mitochondria-controlled (intrinsic) apoptosis is a mainstay of current anti-neoplastic chemotherapies. Activation of this death pathway is counteracted by BCL-2-like proteins, which functionally set the threshold for apoptosis and determine whether malignant cells are sensitive or resistant to anti-cancer treatments. Hence, unlocking the intrinsic apoptotic cascade and promoting the cell's commitment to undergo apoptosis concordantly promotes efficacy of anti-cancer treatments. Here, we show that hyperosmotic stress enforces addiction of colorectal cancer cells to BCL-XL, thereby exhausting the protective capacity of BCL-2-like proteins and priming mitochondria for death. Our work identifies osmotic pressure as a cell extrinsic factor that modulates responsiveness of colorectal cancer cells to therapy.
Collapse
|
56
|
Intrinsic apoptosis circumvents the functional decline of circulating platelets but does not cause the storage lesion. Blood 2018; 132:197-209. [DOI: 10.1182/blood-2017-11-816355] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 05/07/2018] [Indexed: 01/21/2023] Open
Abstract
Key Points
BAK/BAX depletion in murine platelets reveals that intrinsic apoptosis is not required for the development of the platelet storage lesion. Restriction of platelet life span by intrinsic apoptosis is pivotal to maintain a functional, hemostatically reactive platelet population.
Collapse
|
57
|
Agotegaray MA, Campelo AE, Zysler RD, Gumilar F, Bras C, Gandini A, Minetti A, Massheimer VL, Lassalle VL. Magnetic nanoparticles for drug targeting: from design to insights into systemic toxicity. Preclinical evaluation of hematological, vascular and neurobehavioral toxicology. Biomater Sci 2018; 5:772-783. [PMID: 28256646 DOI: 10.1039/c6bm00954a] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A simple two-step drug encapsulation method was developed to obtain biocompatible magnetic nanocarriers for the potential targeted treatment of diverse diseases. The nanodevice consists of a magnetite core coated with chitosan (Chit@MNPs) as a platform for diclofenac (Dic) loading as a model drug (Dic-Chit@MNPs). Mechanistic and experimental conditions related to drug incorporation and quantification are further addressed. This multi-disciplinary study aims to elucidate the toxicological impact of the MNPs at hematological, vascular, neurological and behavioral levels. Blood compatibility assays revealed that MNPs did not affect either erythrosedimentation rates or erythrocyte integrity at the evaluated doses (1, 10 and 100 μg mL-1). A microscopic evaluation of blood smears indicated that MNPs did not induce morphological changes in blood cells. Platelet aggregation was not affected by MNPs either and just a slight diminution was observed with Dic-Chit@MNPs, an effect possibly due to diclofenac. The examined formulations did not exert cytotoxicity on rat aortic endothelial cells and no changes in cell viability or their capacity to synthesize NO were observed. Behavioral and functional nervous system parameters in a functional observational battery were assessed after a subacute treatment of mice with Chit@MNPs. The urine pools of the exposed group were decreased. Nephritis and an increased number of megakaryocytes in the spleen were observed in the histopathological studies. Sub-acute exposure to Chit@MNPs did not produce significant changes in the parameters used to evaluate neurobehavioral toxicity. The aspects focused on within this manuscript are relevant at the pre-clinical level providing new and novel knowledge concerning the biocompatibility of magnetic nanodevices for biomedical applications.
Collapse
Affiliation(s)
- Mariela A Agotegaray
- INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina.
| | - Adrián E Campelo
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Roberto D Zysler
- CONICET - Centro Atómico Bariloche, Instituto Balseiro, S.C. de Bariloche, Argentina
| | - Fernanda Gumilar
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Cristina Bras
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Ariel Gandini
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Alejandra Minetti
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Virginia L Massheimer
- Instituto de Investigaciones Biológicas y Biomédicas del Sur (INBIOSUR-CONICET)-UNS Dpto. de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina
| | - Verónica L Lassalle
- INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Argentina.
| |
Collapse
|
58
|
McArthur K, Kile BT. Apoptotic Caspases: Multiple or Mistaken Identities? Trends Cell Biol 2018; 28:475-493. [PMID: 29551258 DOI: 10.1016/j.tcb.2018.02.003] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 01/31/2018] [Accepted: 02/07/2018] [Indexed: 12/22/2022]
Abstract
The mitochondrial caspase cascade was originally thought to be required for apoptotic death driven by Bak/Bax-mediated intrinsic apoptosis. It has also been ascribed several 'non-apoptotic' functions, including differentiation, proliferation, and cellular reprogramming. Recent work has demonstrated that, during apoptosis, the caspase cascade suppresses damage-associated molecular pattern (DAMP)-initiated production of cytokines such as type I interferon by the dying cell. The caspase cascade is not required for death to occur; instead, it shapes the immunogenic properties of the apoptotic cell. This raises questions about the role of apoptotic caspases in regulating DAMP signaling more generally, puts a new perspective on their non-apoptotic functions, and suggests that pharmacological caspase inhibitors might find new applications as antiviral or anticancer agents.
Collapse
Affiliation(s)
- Kate McArthur
- Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Benjamin T Kile
- Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia.
| |
Collapse
|
59
|
Mechanisms of platelet clearance and translation to improve platelet storage. Blood 2018; 131:1512-1521. [PMID: 29475962 DOI: 10.1182/blood-2017-08-743229] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 01/28/2018] [Indexed: 02/01/2023] Open
Abstract
Hundreds of billions of platelets are cleared daily from circulation via efficient and highly regulated mechanisms. These mechanisms may be stimulated by exogenous reagents or environmental changes to accelerate platelet clearance, leading to thrombocytopenia. The interplay between antiapoptotic Bcl-xL and proapoptotic molecules Bax and Bak sets an internal clock for the platelet lifespan, and BH3-only proteins, mitochondrial permeabilization, and phosphatidylserine (PS) exposure may also contribute to apoptosis-induced platelet clearance. Binding of plasma von Willebrand factor or antibodies to the ligand-binding domain of glycoprotein Ibα (GPIbα) on platelets can activate GPIb-IX in a shear-dependent manner by inducing unfolding of the mechanosensory domain therein, and trigger downstream signaling in the platelet including desialylation and PS exposure. Deglycosylated platelets are recognized by the Ashwell-Morell receptor and potentially other scavenger receptors, and are rapidly cleared by hepatocytes and/or macrophages. Inhibitors of platelet clearance pathways, including inhibitors of GPIbα shedding, neuraminidases, and platelet signaling, are efficacious at preserving the viability of platelets during storage and improving their recovery and survival in vivo. Overall, common mechanisms of platelet clearance have begun to emerge, suggesting potential strategies to extend the shelf-life of platelets stored at room temperature or to enable refrigerated storage.
Collapse
|
60
|
CK2β regulates thrombopoiesis and Ca2+-triggered platelet activation in arterial thrombosis. Blood 2017; 130:2774-2785. [DOI: 10.1182/blood-2017-05-784413] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/12/2017] [Indexed: 02/06/2023] Open
Abstract
Key Points
CK2β is critically required for thrombopoiesis by regulating tubulin polymerization, MK fragmentation, and proplatelet formation. CK2β facilitates inositol triphosphate–mediated increase of cytosolic Ca2+ and is essential for platelet activation in arterial thrombosis in vivo.
Collapse
|
61
|
Mahfoudhi E, Lordier L, Marty C, Pan J, Roy A, Roy L, Rameau P, Abbes S, Debili N, Raslova H, Chang Y, Debussche L, Vainchenker W, Plo I. P53 activation inhibits all types of hematopoietic progenitors and all stages of megakaryopoiesis. Oncotarget 2017; 7:31980-92. [PMID: 26959882 PMCID: PMC5077990 DOI: 10.18632/oncotarget.7881] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/23/2016] [Indexed: 02/07/2023] Open
Abstract
TP53 also known as p53 is a tumor suppressor gene mutated in a variety of cancers. P53 is involved in cell cycle, apoptosis and DNA repair mechanisms and is thus tightly controlled by many regulators. Recently, strategies to treat cancer have focused on the development of MDM2 antagonists to induce p53 stabilization and restore cell death in p53 non-mutated cancers. However, some of these molecules display adverse effects in patients including induction of thrombocytopenia. In the present study, we have explored the effect of SAR405838 not only on human megakaryopoiesis but also more generally on hematopoiesis. We compared its effect to MI-219 and Nutlin, which are less potent MDM2 antagonists than SAR405838. We found that all these compounds induce a deleterious effect on all types of hematopoietic progenitors, as well as on erythroid and megakaryocytic differentiation. Moreover, they inhibit both early and late stages of megakaryopoiesis including ploidization and proplatelet formation. In conclusion, MDM2 antagonists induced a major hematopoietic defect in vitro as well as an inhibition of all stages of megakaryopoiesis that may account for in vivo thrombocytopenia observed in treated patients.
Collapse
Affiliation(s)
- Emna Mahfoudhi
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratory of Excellence GR-Ex, Villejuif, France.,Laboratoire d'Hématologie Moléculaire et Cellulaire, Institut Pasteur de Tunis, Université de Tunis El Manar, Belvédère, Tunisie
| | - Larissa Lordier
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Caroline Marty
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Jiajia Pan
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Anita Roy
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Lydia Roy
- Départment of Clinical Hematology, Hôpital Henri-Mondor, Créteil, France
| | | | - Salem Abbes
- Laboratoire d'Hématologie Moléculaire et Cellulaire, Institut Pasteur de Tunis, Université de Tunis El Manar, Belvédère, Tunisie
| | - Najet Debili
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Hana Raslova
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | - Yunhua Chang
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France
| | | | - William Vainchenker
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratory of Excellence GR-Ex, Villejuif, France
| | - Isabelle Plo
- INSERM, UMR 1170, Laboratory of Excellence GR-Ex, Villejuif, France.,UMR 1170, Université Paris-Saclay, Gustave Roussy, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratory of Excellence GR-Ex, Villejuif, France
| |
Collapse
|
62
|
Apoptosis in megakaryocytes and platelets: the life and death of a lineage. Blood 2017; 131:605-610. [PMID: 29259001 DOI: 10.1182/blood-2017-11-742684] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/03/2017] [Indexed: 12/17/2022] Open
Abstract
Despite their profoundly different cellular composition, size, and function, megakaryocytes and platelets both depend on restraint of the intrinsic (or "mitochondrial") apoptosis pathway by BCL-2 family prosurvival proteins for their development and viability. Activation of the pathway contributes to the clearance of megakaryocytes following platelet shedding and constrains platelet lifespan in the circulation. Important questions remain as to how apoptosis is initiated in these cells at steady state and in response to pathophysiological insults.
Collapse
|
63
|
Fulda S. Therapeutic opportunities based on caspase modulation. Semin Cell Dev Biol 2017; 82:150-157. [PMID: 29247787 DOI: 10.1016/j.semcdb.2017.12.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/05/2017] [Accepted: 12/11/2017] [Indexed: 02/07/2023]
Abstract
Caspases are a family of proteolytic enzymes that play a critical role in the regulation of programmed cell death via apoptosis. Activation of caspases is frequently impaired in human cancers, contributing to cancer formation, progression and therapy resistance. A better understanding of the molecular mechanisms regulating caspase activation in cancer cells is therefore highly important. Thus, targeted modulation of caspase activation and apoptosis represents a promising approach for the development of new therapeutic options to elucidate cancer cell death.
Collapse
Affiliation(s)
- Simone Fulda
- Institute for Experimental Cancer Research in Pediatrics, Goethe-University Frankfurt, Komturstrasse 3a, 60528, Frankfurt, Germany; German Cancer Consortium (DKTK), Partner Site Frankfurt, Germany; German Cancer Research Center (DKFZ), Heidelberg, Germany.
| |
Collapse
|
64
|
Lorenz V, Ramsey H, Liu ZJ, Italiano J, Hoffmeister K, Bihorel S, Mager D, Hu Z, Slayton WB, Kile BT, Sola-Visner M, Ferrer-Marin F. Developmental Stage-Specific Manifestations of Absent TPO/c-MPL Signalling in Newborn Mice. Thromb Haemost 2017; 117:2322-2333. [PMID: 29212120 DOI: 10.1160/th17-06-0433] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Congenital amegakaryocytic thrombocytopaenia (CAMT) is a disorder caused by c-MPL mutations that impair thrombopoietin (TPO) signalling, resulting in a near absence of megakaryocytes (MKs). While this phenotype is consistent in adults, neonates with CAMT can present with severe thrombocytopaenia despite normal MK numbers. To investigate this, we characterized MKs and platelets in newborn c-MPL –/– mice. Liver MKs in c-MPL –/– neonates were reduced in number and size compared with wild-type (WT) age-matched MKs, and exhibited ultrastructural abnormalities not found in adult c-MPL –/– MKs. Platelet counts were lower in c-MPL –/– compared with WT mice at birth and did not increase over the first 2 weeks of life. In vivo biotinylation revealed a significant reduction in the platelet half-life of c-MPL –/– newborn mice (P2) compared with age-matched WT pups, which was not associated with ultrastructural abnormalities. Genetic deletion of the pro-apoptotic Bak did not rescue the severely reduced platelet half-life of c-MPL –/– newborn mice, suggesting that it was due to factors other than platelets entering apoptosis early. Indeed, adult GFP+ (green fluorescent protein transgenic) platelets transfused into thrombocytopenic c-MPL –/– P2 pups also had a shortened lifespan, indicating the importance of cell-extrinsic factors. In addition, neonatal platelets from WT and c-MPL –/– mice exhibited reduced P-selectin surface expression following stimulation compared with adult platelets of either genotype, and platelets from c-MPL –/– neonates exhibited reduced glycoprotein IIb/IIIa (GPIIb/IIIa) activation in response to thrombin compared with age-matched WT platelets. Taken together, our findings indicate that c-MPL deficiency is associated with abnormal maturation of neonatal MKs and developmental stage-specific defects in platelet function.
Collapse
Affiliation(s)
- Viola Lorenz
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Haley Ramsey
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Zhi-Jian Liu
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Joseph Italiano
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Karin Hoffmeister
- Division of Hematology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States.,Blood Center of Wisconsin, Blood Research Institute, Milwaukee, Wisconsin, United States
| | - Sihem Bihorel
- Department of Pharmaceutical Sciences, University of Buffalo, State University of New York, Buffalo, New York, United States.,College of Pharmacy, Center for Pharmacometrics and Systems Pharmacology, Orlando, Florida, United States
| | - Donald Mager
- Department of Pharmaceutical Sciences, University of Buffalo, State University of New York, Buffalo, New York, United States
| | - Zhongbo Hu
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States
| | - William B Slayton
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States
| | - Benjamin T Kile
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Martha Sola-Visner
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Francisca Ferrer-Marin
- Division of Newborn Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States.,Unidad de Hematología y Oncología Médica, Hospital Morales-Meseguer, Centro de Hemodonacion, IMIB-Murcia, CIBERER (CB15/00055), UCAM, Spain
| |
Collapse
|
65
|
Chen S, Hu M, Shen M, Xu Y, Wang C, Wang X, Li F, Zeng D, Chen F, Zhao G, Chen M, Wang F, Cheng T, Su Y, Zhao J, Wang S, Wang J. Dopamine induces platelet production from megakaryocytes via oxidative stress-mediated signaling pathways. Platelets 2017; 29:702-708. [PMID: 29119850 DOI: 10.1080/09537104.2017.1356451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Dopamine (DA), a catecholamine neurotransmitter, is known to for its diverse roles on hematopoiesis, yet its function in thrombopoiesis remains poorly understood. This study shows that DA stimulation can directly induce platelet production from megakaryocytes (MKs) in the final stages of thrombopoiesis via a reactive oxygen species (ROS)-dependent pathway. The mechanism was suggested by the results that DA treatment could significantly elevate the ROS levels in MKs, and time-dependently activate oxidative stress-mediated signaling, including p38 mitogen-activated protein kinase, c-Jun NH2-terminal kinase, and caspase-3 signaling pathways, while the antioxidants N-acetylcysteine and L-glutathione could effectively inhibit the activation of these signaling pathways, as well as the ROS increase and platelet production triggered by DA. Therefore, our data revealed that the direct role and mechanism of DA in thrombopoiesis, which provides new insights into the function recognition of DA in hematopoiesis.
Collapse
Affiliation(s)
- Shilei Chen
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Mengjia Hu
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Mingqiang Shen
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Yang Xu
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Cheng Wang
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Xinmiao Wang
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Fengju Li
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Dongfeng Zeng
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China.,c Department of Hematology, Daping Hospital , Third Military Medical University , Chongqing , China
| | - Fang Chen
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Gaomei Zhao
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Mo Chen
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Fengchao Wang
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Tianmin Cheng
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Yongping Su
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Jinghong Zhao
- b Department of Nephrology, Xinqiao Hospital , Third Military Medical University , Chongqing , China
| | - Song Wang
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| | - Junping Wang
- a State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury, Chongqing Engineering Research Center for Nanomedicine, College of Preventive Medicine , Third Military Medical University , Chongqing , China
| |
Collapse
|
66
|
Anti-apoptotic BCL-2 family members in development. Cell Death Differ 2017; 25:37-45. [PMID: 29099482 PMCID: PMC5729530 DOI: 10.1038/cdd.2017.170] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 01/17/2023] Open
Abstract
Almost 30 years ago it was first appreciated that anti-apoptotic B-cell lymphoma-2 (BCL-2) prevents the induction of apoptosis not only in malignant cells, but also in normal cellular lineages. This critical observation has rapidly evolved from merely identifying new BCL-2 family members to understanding how their biochemical interactions trigger the cell death process, and, more recently, to pharmacological inhibition of anti-apoptotic BCL-2 function in disease. Indeed, the proper regulation of apoptosis is important in many aspects of life including development, homeostasis, and disease biology. To better understand these processes, scientists have used many tools to assess the contribution of individual anti-apoptotic BCL-2 family members. This review will focus on the prominent roles for BCL-2 and other pro-survival family members in promoting the development of mammals during early embryogenesis, neurogenesis, and hematopoiesis.
Collapse
|
67
|
Yang JG, Wang LL, Ma DC. Effects of vascular endothelial growth factors and their receptors on megakaryocytes and platelets and related diseases. Br J Haematol 2017; 180:321-334. [PMID: 29076133 DOI: 10.1111/bjh.15000] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
It is well known that vascular endothelial growth factors (VEGFs) and their receptors (vascular endothelial growth factor receptors, VEGFRs) are expressed in different tissues, and VEGF-VEGFR loops regulate a wide range of responses, including metabolic homeostasis, cell proliferation, migration and tubuleogenesis. As ligands, VEGFs act on three structurally related VEGFRs (VEGFR1, VEGFR2 and VEGFR3 [also termed FLT1, KDR and FLT4, respectively]) that deliver downstream signals. Haematopoietic stem cells (HSCs), megakaryocytic cell lines, cultured megakaryocytes (MKs), primary MKs and abnormal MKs express and secrete VEGFs. During the development from HSCs to MKs, VEGFR1, VEGFR2 and VEGFR3 are expressed at different developmental stages, respectively, and re-expressed, e.g., VEGFR2, and play different roles in commitment, differentiation, proliferation, survival and polyplodization of HSCs/MKs via autocrine, paracrine and/or even intracrine loops. Moreover, VEGFs and their receptors are abnormally expressed in MK-related diseases, including myeloproliferative neoplasms, myelodysplastic syndromes and acute megakaryocytic leukaemia (a rare subtype of acute myeloid leukaemia), and they lead to the disordered proliferation/differentiation of bone marrow cells and angiogenesis, indicating that they are closely related to these diseases. Thus, targeting VEGF-VEGFR loops may be of potential therapeutic value.
Collapse
Affiliation(s)
- Jin-Gang Yang
- Department of Experimental Medicine, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China
| | - Li-Li Wang
- Department of Experimental Medicine, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China
| | - Dong-Chu Ma
- Department of Experimental Medicine, General Hospital of Shenyang Military Region, Shenyang, Liaoning, China
| |
Collapse
|
68
|
Yuan Y, Alwis I, Wu MCL, Kaplan Z, Ashworth K, Bark D, Pham A, Mcfadyen J, Schoenwaelder SM, Josefsson EC, Kile BT, Jackson SP. Neutrophil macroaggregates promote widespread pulmonary thrombosis after gut ischemia. Sci Transl Med 2017; 9:eaam5861. [PMID: 28954929 DOI: 10.1126/scitranslmed.aam5861] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/02/2017] [Accepted: 08/21/2017] [Indexed: 11/02/2022]
Abstract
Gut ischemia is common in critically ill patients, promoting thrombosis and inflammation in distant organs. The mechanisms linking hemodynamic changes in the gut to remote organ thrombosis remain ill-defined. We demonstrate that gut ischemia in the mouse induces a distinct pulmonary thrombotic disorder triggered by neutrophil macroaggregates. These neutrophil aggregates lead to widespread occlusion of pulmonary arteries, veins, and the microvasculature. A similar pulmonary neutrophil-rich thrombotic response occurred in humans with the acute respiratory distress syndrome. Intravital microscopy during gut ischemia-reperfusion injury revealed that rolling neutrophils extract large membrane fragments from remnant dying platelets in multiple organs. These platelet fragments bridge adjacent neutrophils to facilitate macroaggregation. Platelet-specific deletion of cyclophilin D, a mitochondrial regulator of cell necrosis, prevented neutrophil macroaggregation and pulmonary thrombosis. Our studies demonstrate the existence of a distinct pulmonary thrombotic disorder triggered by dying platelets and neutrophil macroaggregates. Therapeutic targeting of platelet death pathways may reduce pulmonary thrombosis in critically ill patients.
Collapse
Affiliation(s)
- Yuping Yuan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Imala Alwis
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Mike C L Wu
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Zane Kaplan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Katrina Ashworth
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - David Bark
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Alan Pham
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria 3181, Australia
| | - James Mcfadyen
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
| | - Emma C Josefsson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Benjamin T Kile
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
| | - Shaun P Jackson
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia.
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| |
Collapse
|
69
|
Platelet populations and priming in hematological diseases. Blood Rev 2017; 31:389-399. [PMID: 28756877 DOI: 10.1016/j.blre.2017.07.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/26/2017] [Accepted: 07/18/2017] [Indexed: 01/01/2023]
Abstract
In healthy subjects and patients with hematological diseases, platelet populations can be distinguished with different response spectra in hemostatic and vascular processes. These populations partly overlap, and are less distinct than those of leukocytes. The platelet heterogeneity is linked to structural properties, and is enforced by inequalities in the environment. Contributing factors are variability between megakaryocytes, platelet ageing, and positive or negative priming of platelets during their time in circulation. Within a hemostatic plug or thrombus, platelet heterogeneity is enhanced by unequal exposure to agonists, with populations of contracted platelets in the thrombus core, discoid platelets at the thrombus surface, patches of ballooned and procoagulant platelets forming thrombin, and coated platelets binding fibrin. Several pathophysiological hematological conditions can positively or negatively prime the responsiveness of platelet populations. As a consequence, in vivo and in vitro markers of platelet activation can differ in thrombotic and hematological disorders.
Collapse
|
70
|
Draper JE, Sroczynska P, Leong HS, Fadlullah MZH, Miller C, Kouskoff V, Lacaud G. Mouse RUNX1C regulates premegakaryocytic/erythroid output and maintains survival of megakaryocyte progenitors. Blood 2017; 130:271-284. [PMID: 28490570 PMCID: PMC5833261 DOI: 10.1182/blood-2016-06-723635] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 04/21/2017] [Indexed: 12/13/2022] Open
Abstract
RUNX1 is crucial for the regulation of megakaryocyte specification, maturation, and thrombopoiesis. Runx1 possesses 2 promoters: the distal P1 and proximal P2 promoters. The major protein isoforms generated by P1 and P2 are RUNX1C and RUNX1B, respectively, which differ solely in their N-terminal amino acid sequences. RUNX1C is the most abundantly expressed isoform in adult hematopoiesis, present in all RUNX1-expressing populations, including the cKit+ hematopoietic stem and progenitor cells. RUNX1B expression is more restricted, being highly expressed in the megakaryocyte lineage but downregulated during erythropoiesis. We generated a Runx1 P1 knock-in of RUNX1B, termed P1-MRIPV This mouse line lacks RUNX1C expression but has normal total RUNX1 levels, solely comprising RUNX1B. Using this mouse line, we establish a specific requirement for the P1-RUNX1C isoform in megakaryopoiesis, which cannot be entirely compensated for by RUNX1B overexpression. P1 knock-in megakaryocyte progenitors have reduced proliferative capacity and undergo increased cell death, resulting in thrombocytopenia. P1 knock-in premegakaryocyte/erythroid progenitors demonstrate an erythroid-specification bias, evident from increased erythroid colony-forming ability and decreased megakaryocyte output. At a transcriptional level, multiple erythroid-specific genes are upregulated and megakaryocyte-specific transcripts are downregulated. In addition, proapoptotic pathways are activated in P1 knock-in premegakaryocyte/erythroid progenitors, presumably accounting for the increased cell death in the megakaryocyte progenitor compartment. Unlike in the conditional adult Runx1 null models, megakaryocytic maturation is not affected in the P1 knock-in mice, suggesting that RUNX1B can regulate endomitosis and thrombopoiesis. Therefore, despite the high degree of structural similarity, RUNX1B and RUNX1C isoforms have distinct and specific roles in adult megakaryopoiesis.
Collapse
Affiliation(s)
- Julia E Draper
- Cancer Research UK Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| | - Patrycja Sroczynska
- Cancer Research UK Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
- Biotech Research and Innovation Center and
- Center for Epigenetics, University of Copenhagen, Copenhagen, Denmark; and
| | - Hui Sun Leong
- Cancer Research UK Applied Computational Biology and Bioinformatics Group, Cancer Research UK Manchester Institute and
| | - Muhammad Z H Fadlullah
- Cancer Research UK Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| | - Crispin Miller
- Cancer Research UK Applied Computational Biology and Bioinformatics Group, Cancer Research UK Manchester Institute and
| | - Valerie Kouskoff
- Division of Developmental Biology & Medicine, The University of Manchester, Manchester, United Kingdom
| | - Georges Lacaud
- Cancer Research UK Stem Cell Biology Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, United Kingdom
| |
Collapse
|
71
|
Identifying and enriching platelet-producing human stem cell-derived megakaryocytes using factor V uptake. Blood 2017; 130:192-204. [PMID: 28455282 DOI: 10.1182/blood-2017-01-761049] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 04/14/2017] [Indexed: 12/21/2022] Open
Abstract
Stem cell-derived platelets have the potential to replace donor platelets for transfusion. Defining the platelet-producing megakaryocytes (MKs) within the heterogeneous MK culture may help to optimize the in vitro generation of platelets. Using 2 human stem cell models of megakaryopoiesis, we identified novel MK populations corresponding to distinct maturation stages. An immature, low granular (LG) MK pool (defined by side scatter on flow cytometry) gives rise to a mature high granular (HG) pool, which then becomes damaged by apoptosis and glycoprotein Ib α chain (CD42b) shedding. We define an undamaged HG/CD42b+ MK subpopulation, which endocytoses fluorescently labeled coagulation factor V (FV) from the media into α-granules and releases functional FV+CD42b+ human platelet-like particles in vitro and when infused into immunodeficient mice. Importantly, these FV+ particles have the same size distribution as infused human donor platelets and are preferentially incorporated into clots after laser injury. Using drugs to protect HG MKs from apoptosis and CD42b shedding, we also demonstrate that apoptosis precedes CD42b shedding and that apoptosis inhibition enriches the FV+ HG/CD42b+ MKs, leading to increased platelet yield in vivo, but not in vitro. These studies identify a transition between distinct MK populations in vitro, including one that is primed for platelet release. Technologies to optimize and select these platelet-ready MKs may be important to efficiently generate functional platelets from in vitro-grown MKs.
Collapse
|
72
|
Smith CW, Thomas SG, Raslan Z, Patel P, Byrne M, Lordkipanidzé M, Bem D, Meyaard L, Senis YA, Watson SP, Mazharian A. Mice Lacking the Inhibitory Collagen Receptor LAIR-1 Exhibit a Mild Thrombocytosis and Hyperactive Platelets. Arterioscler Thromb Vasc Biol 2017; 37:823-835. [PMID: 28336561 DOI: 10.1161/atvbaha.117.309253] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 03/08/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is a collagen receptor that belongs to the inhibitory immunoreceptor tyrosine-based inhibition motif-containing receptor family. It is an inhibitor of signaling via the immunoreceptor tyrosine-based activation motif-containing collagen receptor complex, glycoprotein VI-FcRγ-chain. It is expressed on hematopoietic cells, including immature megakaryocytes, but is not detectable on platelets. Although the inhibitory function of LAIR-1 has been described in leukocytes, its physiological role in megakaryocytes and in particular in platelet formation has not been explored. In this study, we investigate the role of LAIR-1 in megakaryocyte development and platelet production by generating LAIR-1-deficient mice. APPROACH AND RESULTS Mice lacking LAIR-1 exhibit a significant increase in platelet counts, a prolonged platelet half-life in vivo, and increased proplatelet formation in vitro. Interestingly, platelets from LAIR-1-deficient mice exhibit an enhanced reactivity to collagen and the glycoprotein VI-specific agonist collagen-related peptide despite not expressing LAIR-1, and mice showed enhanced thrombus formation in the carotid artery after ferric chloride injury. Targeted deletion of LAIR-1 in mice results in an increase in signaling downstream of the glycoprotein VI-FcRγ-chain and integrin αIIbβ3 in megakaryocytes because of enhanced Src family kinase activity. CONCLUSIONS Findings from this study demonstrate that ablation of LAIR-1 in megakaryocytes leads to increased Src family kinase activity and downstream signaling in response to collagen that is transmitted to platelets, rendering them hyper-reactive specifically to agonists that signal through Syk tyrosine kinases, but not to G-protein-coupled receptors.
Collapse
Affiliation(s)
- Christopher W Smith
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Steven G Thomas
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Zaher Raslan
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Pushpa Patel
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Maxwell Byrne
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Marie Lordkipanidzé
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Danai Bem
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Linde Meyaard
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Yotis A Senis
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Steve P Watson
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.)
| | - Alexandra Mazharian
- From the Institute of Cardiovascular Sciences, College of Medical and Dental Sciences (C.W.S., S.G.T., Z.R., P.P., M.B., M.L., Y.A.S., S.P.W., A.M.), and Institute of Applied Health Research, College of Medical and Dental Sciences (D.B.), University of Birmingham, United Kingdom; and Laboratory of Translational Immunology, Department of Immunology, University Medical Center Utrecht, the Netherlands (L.M.).
| |
Collapse
|
73
|
Solier S, Fontenay M, Vainchenker W, Droin N, Solary E. Non-apoptotic functions of caspases in myeloid cell differentiation. Cell Death Differ 2017; 24:1337-1347. [PMID: 28211870 DOI: 10.1038/cdd.2017.19] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/06/2017] [Accepted: 01/16/2017] [Indexed: 12/26/2022] Open
Abstract
Subtle caspase activation is associated with the differentiation of several myeloid lineages. A tightly orchestrated dance between caspase-3 activation and the chaperone HSP70 that migrates to the nucleus to protect the master regulator GATA-1 from cleavage transiently occurs in basophilic erythroblasts and may prepare nucleus and organelle expel that occurs at the terminal phase of erythroid differentiation. A spatially restricted activation of caspase-3 occurs in maturing megakaryocytes to promote proplatelet maturation and platelet shedding in the bloodstream. In a situation of acute platelet need, caspase-3 could be activated in response to IL-1α and promote megakaryocyte rupture. In peripheral blood monocytes, colony-stimulating factor-1 provokes the formation of a molecular platform in which caspase-8 is activated, which downregulates nuclear factor-kappa B (NF-κB) activity and activates downstream caspases whose target fragments such as those generated by nucleophosmin (NPM1) cleavage contribute to the generation of resting macrophages. Human monocytes secrete mature IL-1β in response to lipopolysaccharide through an alternative inflammasome activation that involves caspase-8, a pathway that does not lead to cell death. Finally, active caspase-3 is part of the proteases contained in secretory granules of mast cells. Many questions remain on how these proteases are activated in myeloid cell lineages, which target proteins are cleaved, whereas other are protected from proteolysis, the precise role of cleaved proteins in cell differentiation and functions, and the link between these non-apoptotic functions of caspases and the death of these diverse cell types. Better understanding of these functions may generate therapeutic strategies to control cytopenias or modulate myeloid cell functions in various pathological situations.
Collapse
Affiliation(s)
- Stéphanie Solier
- Inserm U1170, Université Paris-Sud, Faculté de Médecine Paris-Sud, Gustave Roussy, Villejuif, France
| | - Michaela Fontenay
- INSERM U1016, Institut Cochin, Paris, France.,Assistance Publique-Hôpitaux de Paris, Service d'Hématologie Biologique, Hôpitaux Universitaires Paris Centre, Paris, France
| | - William Vainchenker
- Inserm U1170, Université Paris-Sud, Faculté de Médecine Paris-Sud, Gustave Roussy, Villejuif, France
| | - Nathalie Droin
- Inserm U1170, Université Paris-Sud, Faculté de Médecine Paris-Sud, Gustave Roussy, Villejuif, France
| | - Eric Solary
- Inserm U1170, Université Paris-Sud, Faculté de Médecine Paris-Sud, Gustave Roussy, Villejuif, France.,Department of Hematology, Gustave Roussy, Villejuif, France
| |
Collapse
|
74
|
Deng G, Yu S, Li Q, He Y, Liang W, Yu L, Xu D, Sun T, Zhang R, Li Q. Investigation of platelet apoptosis in adult patients with chronic immune thrombocytopenia. ACTA ACUST UNITED AC 2016; 22:155-161. [PMID: 27734765 DOI: 10.1080/10245332.2016.1237004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
OBJECTIVES Immune thrombocytopenia (ITP) is an acquired and heterogeneous autoimmune-mediated hematological disease typically characterized by a low platelet count. Emerging evidence over the past several years suggests that platelet biogenesis and ageing are regulated, at least in part, by apoptotic mechanisms. However, the association between decreased platelets and apoptosis in ITP patients is poorly understood. To better understand the role of platelet apoptosis in ITP pathophysiology, we investigated apoptotic markers in platelets acquired from 40 chronic ITP patients. Furthermore, the results of ITP patients were compared to those from 40 healthy individuals. METHODS Markers of apoptosis, including phosphatidylserine (PS) exposure and mitochondrial inner membrane potentials (ΔΨm), were examined using flow cytometry. The expression of pro-apoptotic molecules such as Bak and Bax and anti-apoptotic molecules such as Bcl-xL were determined using quantitative real-time PCR (qRT-PCR) and Western blotting. RESULTS Our study demonstrated that the platelet mitochondrial membrane depolarization in chronic ITP patients tended to be higher than in healthy controls. Additionally, the proportion of platelets with surface-exposed PS in chronic ITP was significantly higher than that of controls. The results showed that the expression levels of Bak and Bax were significantly higher in chronic ITP patients than in healthy controls; Bcl-xL expression levels were significantly decreased in the platelets of chronic ITP patients compared to healthy controls. DISCUSSION AND CONCLUSION study indicates that the enhancement of platelet apoptosis observed in patients with chronic ITP may be one of the pathogenic mechanisms of chronic ITP.
Collapse
Affiliation(s)
- Gang Deng
- a The Ningbo Central Blood Station , Ningbo , China.,b The First Affiliated Hospital of Soochow University , Soochow , China
| | - Shifang Yu
- c The Department of Transfusion Medicine , The Second Affiliated Hospital of Zhejiang University School of Medicine , Hangzhou , China
| | - Qiming Li
- d The Department of Cardiology , The Fourth Affiliated Hospital of Zhejiang University School of Medicine , Yiwu , China
| | - Yunlei He
- a The Ningbo Central Blood Station , Ningbo , China
| | - Wei Liang
- a The Ningbo Central Blood Station , Ningbo , China
| | - Lu Yu
- a The Ningbo Central Blood Station , Ningbo , China
| | - Deyi Xu
- a The Ningbo Central Blood Station , Ningbo , China
| | - Tao Sun
- c The Department of Transfusion Medicine , The Second Affiliated Hospital of Zhejiang University School of Medicine , Hangzhou , China
| | - Ri Zhang
- b The First Affiliated Hospital of Soochow University , Soochow , China
| | - Qiang Li
- e The Department of Laboratory Medicine , The First Affiliated Hospital of Zhejiang Chinese Medical University , Hangzhou , China
| |
Collapse
|
75
|
Lebois M, Dowling MR, Gangatirkar P, Hodgkin PD, Kile BT, Alexander WS, Josefsson EC. Regulation of platelet lifespan in the presence and absence of thrombopoietin signaling. J Thromb Haemost 2016; 14:1882-7. [PMID: 27344013 DOI: 10.1111/jth.13397] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Indexed: 01/09/2023]
Abstract
UNLABELLED Essentials We examined platelet survival in models of absent or enhanced thrombopoietin (TPO) signaling. Platelet lifespan is normal in transgenic mice with chronically enhanced TPO signaling. Mpl deficiency does not negatively affect platelet lifespan in the absence of thrombocytopenia. We conclude that TPO and its receptor Mpl are dispensable for platelet survival in adult mice. SUMMARY Background It is well established that thrombopoietin (TPO), acting via its receptor Mpl, is the major cytokine regulator of platelet biogenesis. The primary mechanism by which TPO signaling stimulates thrombopoiesis is via stimulation of Mpl-expressing hematopoietic progenitors; Mpl on megakaryocytes and platelets acts to control the amount of TPO available. TPO could potentially reduce platelet and/or megakaryocyte apoptosis, and therefore increase the platelet count. However, the effect of TPO receptor signaling on platelet survival is unresolved. Methods and results Here, we investigated platelet survival in mouse models of absent or enhanced TPO signaling. In the absence of thrombocytopenia, Mpl deficiency did not negatively influence platelet lifespan, and nor was platelet survival affected in transgenic mice with chronically increased TPO signaling. Conclusions We conclude that TPO and its receptor Mpl are dispensable for platelet survival in adult mice.
Collapse
Affiliation(s)
- M Lebois
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - M R Dowling
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - P Gangatirkar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - P D Hodgkin
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - B T Kile
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - W S Alexander
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - E C Josefsson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia.
| |
Collapse
|
76
|
Au AE, Josefsson EC. Regulation of platelet membrane protein shedding in health and disease. Platelets 2016; 28:342-353. [PMID: 27494300 DOI: 10.1080/09537104.2016.1203401] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Extracellular proteolysis of platelet plasma membrane proteins is an event that ensues platelet activation. Shedding of surface receptors such as glycoprotein (GP) Ibα, GPV and GPVI as well as externalized proteins P-selectin and CD40L releases soluble ectodomain fragments that are subsequently detectable in plasma. This results in the irreversible functional downregulation of platelet receptor-mediated adhesive interactions and the generation of biologically active fragments. In this review, we describe molecular insights into the regulation of platelet receptor and ligand shedding in health and disease. The scope of this review is specially focused on GPIbα, GPV, GPVI, P-selectin and CD40L where we: (1) describe the basic physiological regulation of expression and shedding of these proteins in hemostasis illustrate alterations in receptor expression during (2) apoptosis and (3) ex vivo storage relevant for blood banking purposes; (4) discuss considerations to be made when analyzing and interpreting shedding of platelet membrane proteins and finally; (5) collate clinical evidence that quantify these platelet proteins during disease.
Collapse
Affiliation(s)
- Amanda E Au
- a The Walter and Eliza Hall Institute of Medical Research, Cancer & Haematology Division , 1G Royal Parade, Melbourne , Australia.,b Department of Medical Biology , The University of Melbourne , Melbourne , Australia
| | - Emma C Josefsson
- a The Walter and Eliza Hall Institute of Medical Research, Cancer & Haematology Division , 1G Royal Parade, Melbourne , Australia.,b Department of Medical Biology , The University of Melbourne , Melbourne , Australia
| |
Collapse
|
77
|
Mitochondria, cholesterol and cancer cell metabolism. Clin Transl Med 2016; 5:22. [PMID: 27455839 PMCID: PMC4960093 DOI: 10.1186/s40169-016-0106-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/26/2016] [Indexed: 12/15/2022] Open
Abstract
Given the role of mitochondria in oxygen consumption, metabolism and cell death regulation, alterations in mitochondrial function or dysregulation of cell death pathways contribute to the genesis and progression of cancer. Cancer cells exhibit an array of metabolic transformations induced by mutations leading to gain-of-function of oncogenes and loss-of-function of tumor suppressor genes that include increased glucose consumption, reduced mitochondrial respiration, increased reactive oxygen species generation and cell death resistance, all of which ensure cancer progression. Cholesterol metabolism is disturbed in cancer cells and supports uncontrolled cell growth. In particular, the accumulation of cholesterol in mitochondria emerges as a molecular component that orchestrates some of these metabolic alterations in cancer cells by impairing mitochondrial function. As a consequence, mitochondrial cholesterol loading in cancer cells may contribute, in part, to the Warburg effect stimulating aerobic glycolysis to meet the energetic demand of proliferating cells, while protecting cancer cells against mitochondrial apoptosis due to changes in mitochondrial membrane dynamics. Further understanding the complexity in the metabolic alterations of cancer cells, mediated largely through alterations in mitochondrial function, may pave the way to identify more efficient strategies for cancer treatment involving the use of small molecules targeting mitochondria, cholesterol homeostasis/trafficking and specific metabolic pathways.
Collapse
|
78
|
Qiu J, Liu X, Li X, Zhang X, Han P, Zhou H, Shao L, Hou Y, Min Y, Kong Z, Wang Y, Wei Y, Liu X, Ni H, Peng J, Hou M. CD8(+) T cells induce platelet clearance in the liver via platelet desialylation in immune thrombocytopenia. Sci Rep 2016; 6:27445. [PMID: 27321376 PMCID: PMC4913243 DOI: 10.1038/srep27445] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/18/2016] [Indexed: 11/09/2022] Open
Abstract
In addition to antiplatelet autoantibodies, CD8+ cytotoxic T lymphocytes (CTLs) play an important role in the increased platelet destruction in immune thrombocytopenia (ITP). Recent studies have highlighted that platelet desialylation leads to platelet clearance via hepatocyte asialoglycoprotein receptors (ASGPRs). Whether CD8+ T cells induce platelet desialylation in ITP remains unclear. Here, we investigated the cytotoxicity of CD8+ T cells towards platelets and platelet desialylation in ITP. We found that the desialylation of fresh platelets was significantly higher in ITP patients with positive cytotoxicity of CD8+ T cells than those without cytotoxicity and controls. In vitro, CD8+ T cells from ITP patients with positive cytotoxicity induced significant platelet desialylation, neuraminidase-1 expression on the platelet surface, and platelet phagocytosis by hepatocytes. To study platelet survival and clearance in vivo, CD61 knockout mice were immunized and their CD8+ splenocytes were used. Platelets co-cultured with these CD8+ splenocytes demonstrated decreased survival in the circulation and increased phagocytosis in the liver. Both neuraminidase inhibitor and ASGPRs competitor significantly improved platelet survival and abrogated platelet clearance caused by CD8+ splenocytes. These findings suggest that CD8+ T cells induce platelet desialylation and platelet clearance in the liver in ITP, which may be a novel mechanism of ITP.
Collapse
Affiliation(s)
- Jihua Qiu
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Xuena Liu
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Xiaoqing Li
- School of Medicine, Zhejiang University, Hangzhou, China
| | - Xu Zhang
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Panpan Han
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Hai Zhou
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Linlin Shao
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Yu Hou
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Yanan Min
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Zhangyuan Kong
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Yawen Wang
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Yu Wei
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Xinguang Liu
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China
| | - Heyu Ni
- Canadian Blood Services and the Department of Laboratory Medicine and Pathobiology, Keenan Research Centre in the Li Ka Shing Knowledge Institute of St. Michael's Hospital, University of Toronto, Toronto, Canada
| | - Jun Peng
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China.,Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, Shandong University, Jinan, China
| | - Ming Hou
- Department of Hematology, Qilu Hospital, Shandong University, Jinan, China.,Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, Shandong University, Jinan, China.,Shandong Provincial Key Laboratory of Immunohematology, Qilu Hospital, Shandong University, Jinan, China
| |
Collapse
|
79
|
Morishima N, Nakanishi K. Proplatelet formation in megakaryocytes is associated with endoplasmic reticulum stress. Genes Cells 2016; 21:798-806. [PMID: 27296088 DOI: 10.1111/gtc.12384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 05/08/2016] [Indexed: 01/02/2023]
Abstract
Although previous studies suggest that proplatelet formation in megakaryocytes involves caspase-3, the mechanism underlying the activation of caspase-3 is unknown. Here, we analyzed caspase activation in a human megakaryoblastic cell line, MEG-01, which forms proplatelets spontaneously. Specific activation of caspase-3 and caspase-4 was found in proplatelets. Consistent with previous observations of caspase-4 autoactivation in response to endoplasmic reticulum (ER) stress, several ER stress marker proteins were expressed during proplatelet formation. A pharmacological ER stressor enhanced platelet production via proplatelet formation, whereas inhibition of caspase-4 caused suppression. These results suggest that ER stress is a mechanism underlying the maturation of megakaryocytes.
Collapse
Affiliation(s)
- Nobuhiro Morishima
- Lipid Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Keiko Nakanishi
- Lipid Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| |
Collapse
|
80
|
Delbridge ARD, Chappaz S, Ritchie ME, Kile BT, Strasser A, Grabow S. Loss of PUMA (BBC3) does not prevent thrombocytopenia caused by the loss of BCL-XL (BCL2L1). Br J Haematol 2016; 174:962-9. [PMID: 27221652 DOI: 10.1111/bjh.14155] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/24/2016] [Indexed: 11/29/2022]
Abstract
Apoptosis is required to maintain tissue homeostasis in multicellular organisms. Platelets, the anucleate cells that are essential for blood clotting, are a prime example. Their brief life span in the circulation is regulated by the intrinsic apoptosis pathway. Pro-survival BCL-XL (also termed BCL2L1) is essential for platelet viability. It functions to restrain the pro-apoptotic BCL-2 family members BAK (also termed BAK1) and BAX, the essential mediators of intrinsic apoptosis. Genetic deletion or pharmacological inhibition of BCL-XL results in thrombocytopenia. Conversely, deletion of BAK in platelets doubles their circulating life span. However, what triggers platelet apoptosis in vivo remains unclear. The pro-apoptotic BH3-only proteins are essential for initiating apoptosis in nucleated cells, and there is some evidence to suggest they also play a role in platelet biology. We investigated whether PUMA (also termed BBC3), a potent BH3-only protein that can inhibit all pro-survival BCL-2 family members as well as directly activate BAX, regulates the death of platelets. Surprisingly, loss of PUMA had no impact on the loss of platelets caused by loss of BCL-XL. It therefore remains to be established whether other BH3-only proteins play a critical role in induction of apoptosis in platelets or whether their death is controlled solely by the interactions between BCL-XL with BAK and BAX.
Collapse
Affiliation(s)
- Alex R D Delbridge
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Stephane Chappaz
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Matthew E Ritchie
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Benjamin T Kile
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Stephanie Grabow
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| |
Collapse
|
81
|
Lee EF, Grabow S, Chappaz S, Dewson G, Hockings C, Kluck RM, Debrincat MA, Gray DH, Witkowski MT, Evangelista M, Pettikiriarachchi A, Bouillet P, Lane RM, Czabotar PE, Colman PM, Smith BJ, Kile BT, Fairlie WD. Physiological restraint of Bak by Bcl-xL is essential for cell survival. Genes Dev 2016; 30:1240-50. [PMID: 27198225 PMCID: PMC4888843 DOI: 10.1101/gad.279414.116] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 04/18/2016] [Indexed: 12/21/2022]
Abstract
Lee et al. describe a mutation in mouse and human Bak that specifically disrupts its interaction with the prosurvival protein Bcl-xL. In vivo, loss of Bcl-xL binding to Bak led to significant defects in T-cell and blood platelet survival. Due to the myriad interactions between prosurvival and proapoptotic members of the Bcl-2 family of proteins, establishing the mechanisms that regulate the intrinsic apoptotic pathway has proven challenging. Mechanistic insights have primarily been gleaned from in vitro studies because genetic approaches in mammals that produce unambiguous data are difficult to design. Here we describe a mutation in mouse and human Bak that specifically disrupts its interaction with the prosurvival protein Bcl-xL. Substitution of Glu75 in mBak (hBAK Q77) for leucine does not affect the three-dimensional structure of Bak or killing activity but reduces its affinity for Bcl-xL via loss of a single hydrogen bond. Using this mutant, we investigated the requirement for physical restraint of Bak by Bcl-xL in apoptotic regulation. In vitro, BakQ75L cells were significantly more sensitive to various apoptotic stimuli. In vivo, loss of Bcl-xL binding to Bak led to significant defects in T-cell and blood platelet survival. Thus, we provide the first definitive in vivo evidence that prosurvival proteins maintain cellular viability by interacting with and inhibiting Bak.
Collapse
Affiliation(s)
- Erinna F Lee
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia; Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia; Olivia Newton-John Cancer Research Institute, Heidelberg, Victoria 3084, Australia; School of Cancer Medicine, La Trobe University, Melbourne, Victoria 3084, Australia
| | - Stephanie Grabow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Stephane Chappaz
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Colin Hockings
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Ruth M Kluck
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marlyse A Debrincat
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Daniel H Gray
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Matthew T Witkowski
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marco Evangelista
- Olivia Newton-John Cancer Research Institute, Heidelberg, Victoria 3084, Australia; School of Cancer Medicine, La Trobe University, Melbourne, Victoria 3084, Australia
| | - Anne Pettikiriarachchi
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Philippe Bouillet
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Rachael M Lane
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Peter M Colman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Brian J Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Benjamin T Kile
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - W Douglas Fairlie
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia; Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia; Olivia Newton-John Cancer Research Institute, Heidelberg, Victoria 3084, Australia; School of Cancer Medicine, La Trobe University, Melbourne, Victoria 3084, Australia
| |
Collapse
|
82
|
Abstract
PURPOSE OF REVIEW The human body produces and removes 10 platelets daily to maintain a normal steady-state platelet count. Platelet production must be tightly regulated to avoid spontaneous bleeding or arterial occlusion and organ damage. Multifaceted and complex mechanisms control platelet removal and production in physiological and pathological conditions. This review will focus on different mechanisms of platelet clearance, with focus on the biological significance of platelet glycans. RECENT FINDINGS The Ashwell-Morrell receptor (AMR) recognizes senescent, desialylated platelets under steady state conditions. Desialylated platelets and the AMR are the physiological ligand-receptor pair regulating hepatic thrombopoietin (TPO) mRNA production, resolving the longstanding mystery of steady state TPO regulation. The AMR-mediated removal of desialylated platelets regulates TPO synthesis in the liver by recruiting JAK2 and STAT3 to increase thrombopoiesis. SUMMARY Inhibition of TPO production downstream of the hepatic AMR-JAK2 signaling cascade could additionally contribute to the thrombocytopenia associated with JAK1/2 treatment, which is clinically used in myeloproliferative neoplasms.
Collapse
|
83
|
You T, Wang Q, Zhu L. Role of autophagy in megakaryocyte differentiation and platelet formation. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2016; 8:28-34. [PMID: 27186320 PMCID: PMC4859876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/08/2016] [Indexed: 06/05/2023]
Abstract
Autophagy is a conserved biological process for digestion and recycling of cytoplasmic constituents in eukaryotic cells. Autophagy may trigger cell death or promote cell survival following various forms of stress. The emerging roles of autophagy in megakaryopoiesis, thrombopoiesis, and platelet function have been uncovered using not only in vitro and in vivo genetic models, but also in clinical observations of autophagic structure in patients with thrombocytopenic disorders. Inhibition of autophagy in early stage of megakaryocyte differentiation appears to impede megakaryocyte maturation, reduce platelet formation, and affect platelet function, whereas autophagic deficiency in mature megakaryocytes gives rise to abnormal platelet activation and function without changing platelet size and number. On the other hand, induction of autophagy by rapamycin in megakaryocytes exhibited substantial therapeutic benefits in patients with immune thrombocytopenic purpura (ITP). This mini-review is to highlight recent progresses in understanding the regulation of autophagy in megakaryopoiesis, thrombopoiesis and platelet function to bridge the gap between autophagy and megakaryocyte/platelet pathophysiology.
Collapse
Affiliation(s)
- Tao You
- Cyrus Tang Hematology Center, Soochow UniversitySuzhou, Jiangsu, P.R. China
- MOH Key Lab of Thrombosis and Hemostasis, Soochow UniversitySuzhou, Jiangsu, P.R. China
- Jiangsu Institute of Hematology of The First Affiliated Hospital, Soochow UniversitySuzhou, Jiangsu, P.R. China
| | - Qi Wang
- Cyrus Tang Hematology Center, Soochow UniversitySuzhou, Jiangsu, P.R. China
- Collaborative Innovation Center of Hematology, Soochow UniversitySuzhou, Jiangsu, P.R. China
| | - Li Zhu
- Cyrus Tang Hematology Center, Soochow UniversitySuzhou, Jiangsu, P.R. China
- Collaborative Innovation Center of Hematology, Soochow UniversitySuzhou, Jiangsu, P.R. China
- MOH Key Lab of Thrombosis and Hemostasis, Soochow UniversitySuzhou, Jiangsu, P.R. China
| |
Collapse
|
84
|
Abstract
The lifespan of platelets in circulation is brief, close to 10 days in humans and 5 days in mice. Bone marrow residing megakaryocytes produce around 100 billion platelets per day. In a healthy individual, the majority of platelets are not consumed by hemostatic processes, but rather their lifespan is controlled by programmed cell death, a canonical intrinsic apoptosis program. In the last decade, insights from genetically manipulated mouse models and pharmacological developments have helped to define the components of the intrinsic, or mitochondrial, apoptosis pathway that controls platelet lifespan. This review focuses on the molecular regulation of apoptosis in platelet survival, reviews thrombocytopenic conditions linked to enhanced platelet death, examines implications of chemotherapy-induced thrombocytopenia through apoptosis-inducing drugs in cancer therapy as well as discusses ex vivo aging of platelets.
Collapse
Affiliation(s)
- Marion Lebois
- a The Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia
| | - Emma C Josefsson
- a The Walter and Eliza Hall Institute of Medical Research , Melbourne , Australia.,b Department of Medical Biology , The University of Melbourne , Melbourne , Australia
| |
Collapse
|
85
|
Malherbe JAJ, Fuller KA, Mirzai B, Kavanagh S, So CC, Ip HW, Guo BB, Forsyth C, Howman R, Erber WN. Dysregulation of the intrinsic apoptotic pathway mediates megakaryocytic hyperplasia in myeloproliferative neoplasms. J Clin Pathol 2016; 69:jclinpath-2016-203625. [PMID: 27060176 PMCID: PMC5136711 DOI: 10.1136/jclinpath-2016-203625] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/08/2016] [Accepted: 03/10/2016] [Indexed: 12/24/2022]
Abstract
AIMS Megakaryocyte expansion in myeloproliferative neoplasms (MPNs) is due to uncontrolled proliferation accompanied by dysregulation of proapoptotic and antiapoptotic mechanisms. Here we have investigated the intrinsic and extrinsic apoptotic pathways of megakaryocytes in human MPNs to further define the mechanisms involved. METHODS The megakaryocytic expression of proapoptotic caspase-8, caspase-9, Diablo, p53 and antiapoptotic survivin proteins was investigated in bone marrow specimens of the MPNs (n=145) and controls (n=15) using immunohistochemistry. The megakaryocyte percentage positivity was assessed by light microscopy and correlated with the MPN entity, JAK2V617F/CALR mutation status and platelet count. RESULTS The proportion of megakaryocytes in the MPNs expressing caspase-8, caspase-9, Diablo, survivin and p53 was significantly greater than controls. A greater proportion of myeloproliferative megakaryocytes expressed survivin relative to its reciprocal inhibitor, Diablo. Differences were seen between myelofibrosis, polycythaemia vera and essential thrombocythaemia for caspase-9 and p53. CALR-mutated cases had greater megakaryocyte p53 positivity compared to those with the JAK2V617F mutation. Proapoptotic caspase-9 expression showed a positive correlation with platelet count, which was most marked in myelofibrosis and CALR-mutated cases. CONCLUSIONS Disruptions targeting the intrinsic apoptotic cascade promote megakaryocyte hyperplasia and thrombocytosis in the MPNs. There is progressive dysfunction of apoptosis as evidenced by the marked reduction in proapoptotic caspase-9 and accumulation of p53 in myelofibrosis. The dysfunction of caspase-9, which is necessary for proplatelet formation, may be the mechanism for the excess thrombocytosis associated with CALR mutations. Survivin seems to be the key protein mediating the megakaryocyte survival signature in the MPNs and is a potential therapeutic target.
Collapse
Affiliation(s)
- Jacques A J Malherbe
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Kathryn A Fuller
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
- PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| | - Bob Mirzai
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
- PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| | - Simon Kavanagh
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
- PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| | - Chi-Chiu So
- Department of Pathology, Faculty of Medicine, University of Hong Kong, Hong Kong, Hong Kong
| | - Ho-Wan Ip
- Department of Pathology & Clinical Biochemistry, Queen Mary Hospital, Hong Kong, Hong Kong
| | - Belinda B Guo
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Cecily Forsyth
- Jarrett Street Specialist Centre, North Gosford, New South Wales, Australia
| | - Rebecca Howman
- PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| | - Wendy N Erber
- Schoolof Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
- PathWest Laboratory Medicine, Nedlands, Western Australia, Australia
| |
Collapse
|
86
|
Johnson B, Fletcher SJ, Morgan NV. Inherited thrombocytopenia: novel insights into megakaryocyte maturation, proplatelet formation and platelet lifespan. Platelets 2016; 27:519-25. [PMID: 27025194 PMCID: PMC5000870 DOI: 10.3109/09537104.2016.1148806] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The study of patients with inherited bleeding problems is a powerful approach in determining the function and regulation of important proteins in human platelets and their precursor, the megakaryocyte. The normal range of platelet counts in the bloodstream ranges from 150 000 to 400 000 platelets per microliter and is normally maintained within a narrow range for each individual. This requires a constant balance between thrombopoiesis, which is primarily controlled by the cytokine thrombopoietin (TPO), and platelet senescence and consumption. Thrombocytopenia can be defined as a platelet count of less than 150 000 per microliter and can be acquired or inherited. Heritable forms of thrombocytopenia are caused by mutations in genes involved in megakaryocyte differentiation, platelet production and platelet removal. In this review, we will discuss the main causative genes known for inherited thrombocytopenia and highlight their diverse functions and whether these give clues on the processes of platelet production, platelet function and platelet lifespan. Additionally, we will highlight the recent advances in novel genes identified for inherited thrombocytopenia and their suggested function.
Collapse
Affiliation(s)
- Ben Johnson
- a Institute of Cardiovascular Sciences, College of Medical and Dental Sciences , University of Birmingham , UK
| | - Sarah J Fletcher
- a Institute of Cardiovascular Sciences, College of Medical and Dental Sciences , University of Birmingham , UK
| | - Neil V Morgan
- a Institute of Cardiovascular Sciences, College of Medical and Dental Sciences , University of Birmingham , UK
| |
Collapse
|
87
|
Kollek M, Müller A, Egle A, Erlacher M. Bcl-2 proteins in development, health, and disease of the hematopoietic system. FEBS J 2016; 283:2779-810. [DOI: 10.1111/febs.13683] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 01/29/2016] [Accepted: 02/12/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Matthias Kollek
- Division of Pediatric Hematology and Oncology; Department of Pediatrics and Adolescent Medicine; University Medical Center of Freiburg; Germany
- Faculty of Biology; University of Freiburg; Germany
| | - Alexandra Müller
- Division of Pediatric Hematology and Oncology; Department of Pediatrics and Adolescent Medicine; University Medical Center of Freiburg; Germany
| | - Alexander Egle
- Laboratory for Immunological and Molecular Cancer Research; 3rd Medical Department for Hematology; Paracelsus Private Medical University Hospital; Salzburg Austria
| | - Miriam Erlacher
- Division of Pediatric Hematology and Oncology; Department of Pediatrics and Adolescent Medicine; University Medical Center of Freiburg; Germany
| |
Collapse
|
88
|
Linkage between the mechanisms of thrombocytopenia and thrombopoiesis. Blood 2016; 127:1234-41. [PMID: 26787737 DOI: 10.1182/blood-2015-07-607903] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 08/19/2015] [Indexed: 12/30/2022] Open
Abstract
Thrombocytopenia is defined as a status in which platelet numbers are reduced. Imbalance between the homeostatic regulation of platelet generation and destruction is 1 potential cause of thrombocytopenia. In adults, platelet generation is a 2-stage process entailing the differentiation of hematopoietic stem cells into mature megakaryocytes (MKs; known as megakaryopoiesis) and release of platelets from MKs (known as thrombopoiesis or platelet biogenesis). Until recently, information about the genetic defects responsible for congenital thrombocytopenia was only available for a few forms of the disease. However, investigations over the past 15 years have identified mutations in genes encoding >20 different proteins that are responsible for these disorders, which has advanced our understanding of megakaryopoiesis and thrombopoiesis. The underlying pathogenic mechanisms can be categorized as (1) defects in MK lineage commitment and differentiation, (2) defects in MK maturation, and (3) defect in platelet release. Using these developmental stage categories, we here update recently described mechanisms underlying megakaryopoiesis and thrombopoiesis and discuss the association between platelet generation systems and thrombocytopenia.
Collapse
|
89
|
Understanding platelet generation from megakaryocytes: implications for in vitro-derived platelets. Blood 2016; 127:1227-33. [PMID: 26787738 DOI: 10.1182/blood-2015-08-607929] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/30/2015] [Indexed: 12/12/2022] Open
Abstract
Platelets are anucleate cytoplasmic discs derived from megakaryocytes that circulate in the blood and have major roles in hemostasis, thrombosis, inflammation, and vascular biology. Platelet transfusions are required to prevent the potentially life-threatening complications of severe thrombocytopenia seen in a variety of medical settings including cancer therapy, trauma, and sepsis. Platelets used in the clinic are currently donor-derived which is associated with concerns over sufficient availability, quality, and complications due to immunologic and/or infectious issues. To overcome our dependence on donor-derived platelets for transfusion, efforts have been made to generate in vitro-based platelets. Work in this area has advanced our understanding of the complex processes that megakaryocytes must undergo to generate platelets both in vivo and in vitro. This knowledge has also defined the challenges that must be overcome to bring in vitro-based platelet manufacturing to a clinical reality. This review will focus on our understanding of committed megakaryocytes and platelet release in vivo and in vitro, and how this knowledge can guide the development of in vitro-derived platelets for clinical application.
Collapse
|
90
|
CCL5 derived from platelets increases megakaryocyte proplatelet formation. Blood 2015; 127:921-6. [PMID: 26647394 DOI: 10.1182/blood-2015-05-644583] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 11/25/2015] [Indexed: 02/07/2023] Open
Abstract
In times of physiological stress, platelet count can transiently rise. What initiates this reactive thrombocytosis is poorly understood. Intriguingly, we found that treating megakaryocytes (MKs) with the releasate from activated platelets increased proplatelet production by 47%. Platelets store inflammatory cytokines, including the chemokine ligand 5 (CCL5, RANTES); after TRAP activation, platelets release over 25 ng/mL CCL5. We hypothesized that CCL5 could regulate platelet production by binding to its receptor, CCR5, on MKs. Maraviroc (CCR5 antagonist) or CCL5 immunodepletion diminished 95% and 70% of the effect of platelet releasate, respectively, suggesting CCL5 derived from platelets is sufficient to drive increased platelet production through MK CCR5. MKs cultured with recombinant CCL5 increased proplatelet production by 50% and had significantly higher ploidy. Pretreating the MK cultures with maraviroc prior to exposure to CCL5 reversed the augmented proplatelet formation and ploidy, suggesting that CCL5 increases MK ploidy and proplatelet formation in a CCR5-dependent manner. Interrogation of the Akt signaling pathway suggested that CCL5/CCR5 may influence proplatelet production by suppressing apoptosis. In an in vivo murine acute colitis model, platelet count significantly correlated with inflammation whereas maraviroc treatment abolished this correlation. We propose that CCL5 signaling through CCR5 may increase platelet counts during physiological stress.
Collapse
|
91
|
Regulating billions of blood platelets: glycans and beyond. Blood 2015; 126:1877-84. [PMID: 26330242 DOI: 10.1182/blood-2015-01-569129] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 08/25/2015] [Indexed: 01/01/2023] Open
Abstract
The human body produces and removes 10(11) platelets daily to maintain a normal steady state platelet count. Platelet production must be regulated to avoid spontaneous bleeding or arterial occlusion and organ damage. Multifaceted and complex mechanisms control platelet production and removal in physiological and pathological conditions. This review will focus on different mechanisms of platelet senescence and clearance with specific emphasis on the role of posttranslational modifications. It will also briefly address platelet transfusion and the role of glycans in the clearance of stored platelets.
Collapse
|
92
|
Malherbe JAJ, Fuller KA, Arshad A, Nangalia J, Romeo G, Hall SL, Meehan KS, Guo B, Howman R, Erber WN. Megakaryocytic hyperplasia in myeloproliferative neoplasms is driven by disordered proliferative, apoptotic and epigenetic mechanisms. J Clin Pathol 2015; 69:155-63. [PMID: 26290261 DOI: 10.1136/jclinpath-2015-203177] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 07/22/2015] [Indexed: 12/31/2022]
Abstract
AIMS Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal proliferative bone marrow diseases characterised by extensive megakaryocytic hyperplasia and morphological atypia. Despite knowledge of genomic defects, the pathobiological processes driving these megakaryocytic abnormalities in MPN remain poorly explained. We have explored the proliferative, apoptotic and epigenetic profiles of megakaryocytes in human MPN. METHODS Immunohistochemical staining was performed on bone marrow trephine biopsies of 81 MPN (with and without JAK2(V617F) and CALR mutations) and 15 normal controls to assess the megakaryocytic expression of biomarkers associated with proliferation (Ki67), apoptosis (Bcl-XL, BNIP-3) and epigenetic regulation (EZH2, SUZ12). RESULTS Myeloproliferative megakaryocytes showed significantly greater expression of proliferative Ki67 and anti-apoptotic Bcl-XL, reduced pro-apoptotic BNIP-3 and increased SUZ12 compared with controls. In essential thrombocythaemia, large-giant megakaryocytes with hyperlobated nuclei showed a trend towards a proliferative signature. In contrast, myelofibrotic megakaryocytes with condensed nuclear chromatin, and cases with CALR mutations, had significant reductions in pro-apoptotic BNIP-3. CONCLUSIONS Uncontrolled megakaryocytic expansion in MPN results from a combination of increased proliferation, attenuated apoptosis and defective epigenetic regulation with CALR mutations favouring apoptotic failure. The higher platelet counts reported to be seen in MPN with CALR mutations may be due to greater dysregulation of megakaryocyte apoptosis.
Collapse
Affiliation(s)
- Jacques A J Malherbe
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Kathryn A Fuller
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Ayesha Arshad
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Jyoti Nangalia
- Cambridge Institute for Medical Research and Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Giuliana Romeo
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia PathWest Laboratory Medicine, Western Australia, Australia
| | - Sara L Hall
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia PathWest Laboratory Medicine, Western Australia, Australia
| | - Katie S Meehan
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Belinda Guo
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Rebecca Howman
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia PathWest Laboratory Medicine, Western Australia, Australia
| | - Wendy N Erber
- School of Pathology and Laboratory Medicine, University of Western Australia, Crawley, Western Australia, Australia PathWest Laboratory Medicine, Western Australia, Australia
| |
Collapse
|
93
|
Josephs TM, Hibbs ME, Ong L, Morison IM, Ledgerwood EC. Interspecies Variation in the Functional Consequences of Mutation of Cytochrome c. PLoS One 2015; 10:e0130292. [PMID: 26086723 PMCID: PMC4472513 DOI: 10.1371/journal.pone.0130292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 05/19/2015] [Indexed: 01/08/2023] Open
Abstract
The naturally occurring human cytochrome c variant (G41S) is associated with a mild autosomal dominant thrombocytopenia (Thrombocytopenia Cargeeg) caused by dysregulation of platelet production. The molecular basis of the platelet production defect is unknown. Despite high conservation of cytochrome c between human and mouse (91.4% identity), introducing the G41S mutation into mouse cytochrome c in a knockin mouse (CycsG41S/G41S) did not recapitulate the low platelet phenotype of Thrombocytopenia Cargeeg. While investigating the cause of this disparity we found a lack of conservation of the functional impact of cytochrome c mutations on caspase activation across species. Mutation of cytochrome c at residue 41 has distinct effects on the ability of cytochrome c to activate caspases depending on the species of both the cytochrome c and its binding partner Apaf-1. In contrast to our previous results showing the G41S mutation increases the ability of human cytochrome c to activate caspases, here we find this activity is decreased in mouse G41S cytochrome c. Additionally unlike wildtype human cytochrome c, G41S cytochrome c is unable to activate caspases in Xenopus embryo extracts. Taken together these results demonstrate a previously unreported species-specific component to the interaction of cytochrome c with Apaf-1. This suggests that the electrostatic interaction between cytochrome c and Apaf-1 is not the sole determinant of binding, with additional factors controlling binding specificity and affinity. These results have important implications for studies of the effects of cytochrome c mutations on the intrinsic apoptosis pathway.
Collapse
Affiliation(s)
- Tracy M. Josephs
- Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Moira E. Hibbs
- Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Lily Ong
- Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
| | - Ian M. Morison
- Department of Pathology, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Elizabeth C. Ledgerwood
- Department of Biochemistry, Otago School of Medical Sciences, University of Otago, Dunedin, New Zealand
- * E-mail:
| |
Collapse
|
94
|
Abstract
Historically, platelet transfusion has proven a reliable way to treat patients suffering from thrombocytopenia or similar ailments. An undersupply of donors, however, has demanded alternative platelet sources. Scientists have therefore sought to recapitulate the biological events that convert hematopoietic stem cells into platelets in the laboratory. Such platelets have shown good function and potential for treatment. Yet the number manufactured ex vivo falls well short of clinical application. Part of the reason is the remarkable gaps in our understanding of the molecular mechanisms driving platelet formation. Using several stem cell sources, scientists have progressively clarified the chemical signaling and physical microenvironment that optimize ex vivo platelets and reconstituted them in synthetic environments. Key advances in cell reprogramming and the ability to propagate self-renewal have extended the lifetime of megakaryocytes to increase the pool of platelet progenitors.
Collapse
Affiliation(s)
- P Karagiannis
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto, Japan
| | - K Eto
- Department of Clinical Application, Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto, Japan
| |
Collapse
|
95
|
Trakala M, Rodríguez-Acebes S, Maroto M, Symonds CE, Santamaría D, Ortega S, Barbacid M, Méndez J, Malumbres M. Functional reprogramming of polyploidization in megakaryocytes. Dev Cell 2015; 32:155-67. [PMID: 25625205 DOI: 10.1016/j.devcel.2014.12.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 10/31/2014] [Accepted: 12/17/2014] [Indexed: 12/30/2022]
Abstract
Polyploidization is a natural process that frequently accompanies differentiation; its deregulation is linked to genomic instability and cancer. Despite its relevance, why cells select different polyploidization mechanisms is unknown. Here we report a systematic genetic analysis of endomitosis, a process in which megakaryocytes become polyploid by entering mitosis but aborting anaphase. Whereas ablation of the APC/C cofactor Cdc20 results in mitotic arrest and severe thrombocytopenia, lack of the kinases Aurora-B, Cdk1, or Cdk2 does not affect megakaryocyte polyploidization or platelet levels. Ablation of Cdk1 forces a switch to endocycles without mitosis, whereas polyploidization in the absence of Cdk1 and Cdk2 occurs in the presence of aberrant re-replication events. Importantly, ablation of these kinases rescues the defects in Cdc20 null megakaryocytes. These findings suggest that endomitosis can be functionally replaced by alternative polyploidization mechanisms in vivo and provide the cellular basis for therapeutic approaches aimed to discriminate mitotic and polyploid cells.
Collapse
Affiliation(s)
- Marianna Trakala
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain
| | | | - María Maroto
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain
| | | | | | | | | | - Juan Méndez
- DNA Replication Group, CNIO, 28029 Madrid, Spain
| | - Marcos Malumbres
- Cell Division and Cancer Group, Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain.
| |
Collapse
|
96
|
Debrincat MA, Pleines I, Lebois M, Lane RM, Holmes ML, Corbin J, Vandenberg CJ, Alexander WS, Ng AP, Strasser A, Bouillet P, Sola-Visner M, Kile BT, Josefsson EC. BCL-2 is dispensable for thrombopoiesis and platelet survival. Cell Death Dis 2015; 6:e1721. [PMID: 25880088 PMCID: PMC4650559 DOI: 10.1038/cddis.2015.97] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 02/25/2015] [Accepted: 03/03/2015] [Indexed: 01/28/2023]
Abstract
Navitoclax (ABT-263), an inhibitor of the pro-survival BCL-2 family proteins BCL-2, BCL-XL and BCL-W, has shown clinical efficacy in certain BCL-2-dependent haematological cancers, but causes dose-limiting thrombocytopaenia. The latter effect is caused by Navitoclax directly inducing the apoptotic death of platelets, which are dependent on BCL-XL for survival. Recently, ABT-199, a selective BCL-2 antagonist, was developed. It has shown promising anti-leukaemia activity in patients whilst sparing platelets, suggesting that the megakaryocyte lineage does not require BCL-2. In order to elucidate the role of BCL-2 in megakaryocyte and platelet survival, we generated mice with a lineage-specific deletion of Bcl2, alone or in combination with loss of Mcl1 or Bclx. Platelet production and platelet survival were analysed. Additionally, we made use of BH3 mimetics that selectively inhibit BCL-2 or BCL-XL. We show that the deletion of BCL-2, on its own or in concert with MCL-1, does not affect platelet production or platelet lifespan. Thrombocytopaenia in Bclx-deficient mice was not affected by additional genetic loss or pharmacological inhibition of BCL-2. Thus, BCL-2 is dispensable for thrombopoiesis and platelet survival in mice.
Collapse
Affiliation(s)
- M A Debrincat
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - I Pleines
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - M Lebois
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
| | - R M Lane
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
| | - M L Holmes
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
| | - J Corbin
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
| | - C J Vandenberg
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - W S Alexander
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - A P Ng
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - A Strasser
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - P Bouillet
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - M Sola-Visner
- Boston Children's Hospital, Division of Newborn Medicine, Boston, MA, USA
| | - B T Kile
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| | - E C Josefsson
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, 1G Royal Parade, Parkville, VIC, Australia
| |
Collapse
|
97
|
Avanzi MP, Izak M, Oluwadara OE, Mitchell WB. Actin inhibition increases megakaryocyte proplatelet formation through an apoptosis-dependent mechanism. PLoS One 2015; 10:e0125057. [PMID: 25875470 PMCID: PMC4397066 DOI: 10.1371/journal.pone.0125057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/14/2015] [Indexed: 12/25/2022] Open
Abstract
Background Megakaryocytes assemble and release platelets through the extension of proplatelet processes, which are cytoplasmic extensions that extrude from the megakaryocyte and form platelets at their tips. Proplatelet formation and platelet release are complex processes that require a combination of structural rearrangements. While the signals that trigger the initiation of proplatelet formation process are not completely understood, it has been shown that inhibition of cytoskeletal signaling in mature megakaryocytes induces proplatelet formation. Megakaryocyte apoptosis may also be involved in initiation of proplatelet extension, although this is controversial. This study inquires whether the proplatelet production induced by cytoskeletal signaling inhibition is dependent on activation of apoptosis. Methods Megakaryocytes derived from human umbilical cord blood CD34+ cells were treated with the actin polymerization inhibitor latrunculin and their ploidy and proplatelet formation were quantitated. Apoptosis activation was analyzed by flow cytometry and luminescence assays. Caspase activity was inhibited by two compounds, ZVAD and QVD. Expression levels of pro-survival and pro-apoptosis genes were measured by quantitative RT-PCR. Protein levels of Bcl-XL, Bax and Bak were measured by western blot. Cell ultrastructure was analyzed by electron microscopy. Results Actin inhibition resulted in increased ploidy and increased proplatelet formation in cultured umbilical cord blood-derived megakaryocytes. Actin inhibition activated apoptosis in the cultured cells. The effects of actin inhibition on proplatelet formation were blocked by caspase inhibition. Increased expression of both pro-apoptotic and pro-survival genes was observed. Pro-survival protein (Bcl-xL) levels were increased compared to levels of pro-apoptotic proteins Bak and Bax. Despite apoptosis being activated, the megakaryocytes underwent minimal ultrastructural changes during actin inhibition. Conclusions We report a correlation between increased proplatelet formation and activation of apoptosis, and that the increase in proplatelet formation in response to actin inhibition is caspase dependent. These findings support a role for apoptosis in proplatelet formation in this model.
Collapse
Affiliation(s)
- Mauro P. Avanzi
- Platelet Biology Laboratory, New York Blood Center, New York, New York, United States of America
| | - Marina Izak
- Platelet Biology Laboratory, New York Blood Center, New York, New York, United States of America
| | | | - William Beau Mitchell
- Platelet Biology Laboratory, New York Blood Center, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
98
|
Grozovsky R, Giannini S, Falet H, Hoffmeister K. Molecular mechanisms regulating platelet clearance and thrombopoietin production. ACTA ACUST UNITED AC 2015. [DOI: 10.1111/voxs.12144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Grozovsky
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
| | - S. Giannini
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
| | - H. Falet
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
| | - K.M. Hoffmeister
- Division of Hematology; Department of Medicine; Brigham and Women's Hospital and Harvard Medical School; Boston MA USA
| |
Collapse
|
99
|
Correia C, Lee SH, Meng XW, Vincelette ND, Knorr KLB, Ding H, Nowakowski GS, Dai H, Kaufmann SH. Emerging understanding of Bcl-2 biology: Implications for neoplastic progression and treatment. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1658-71. [PMID: 25827952 DOI: 10.1016/j.bbamcr.2015.03.012] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/20/2015] [Accepted: 03/22/2015] [Indexed: 02/07/2023]
Abstract
Bcl-2, the founding member of a family of apoptotic regulators, was initially identified as the protein product of a gene that is translocated and overexpressed in greater than 85% of follicular lymphomas (FLs). Thirty years later we now understand that anti-apoptotic Bcl-2 family members modulate the intrinsic apoptotic pathway by binding and neutralizing the mitochondrial permeabilizers Bax and Bak as well as a variety of pro-apoptotic proteins, including the cellular stress sensors Bim, Bid, Puma, Bad, Bmf and Noxa. Despite extensive investigation of all of these proteins, important questions remain. For example, how Bax and Bak breach the outer mitochondrial membrane remains poorly understood. Likewise, how the functions of anti-apoptotic Bcl-2 family members such as eponymous Bcl-2 are affected by phosphorylation or cancer-associated mutations has been incompletely defined. Finally, whether Bcl-2 family members can be successfully targeted for therapeutic advantage is only now being investigated in the clinic. Here we review recent advances in understanding Bcl-2 family biology and biochemistry that begin to address these questions.
Collapse
Affiliation(s)
- Cristina Correia
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Sun-Hee Lee
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - X Wei Meng
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Nicole D Vincelette
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Katherine L B Knorr
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Husheng Ding
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA
| | - Grzegorz S Nowakowski
- Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
| | - Haiming Dai
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA.
| | - Scott H Kaufmann
- Division of Oncology Research, Department of Oncology, Mayo Clinic, Rochester, MN 55905, USA; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905, USA; Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
| |
Collapse
|
100
|
Mitochondrial apoptosis: killing cancer using the enemy within. Br J Cancer 2015; 112:957-62. [PMID: 25742467 PMCID: PMC4366906 DOI: 10.1038/bjc.2015.85] [Citation(s) in RCA: 509] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 01/26/2015] [Accepted: 01/28/2015] [Indexed: 12/11/2022] Open
Abstract
Apoptotic cell death inhibits oncogenesis at multiple stages, ranging from transformation to metastasis. Consequently, in order for cancer to develop and progress, apoptosis must be inhibited. Cell death also plays major roles in cancer treatment, serving as the main effector function of many anti-cancer therapies. In this review, we discuss the role of apoptosis in the development and treatment of cancer. Specifically, we focus upon the mitochondrial pathway of apoptosis—the most commonly deregulated form of cell death in cancer. In this process, mitochondrial outer membrane permeabilisation or MOMP represents the defining event that irrevocably commits a cell to die. We provide an overview of how this pathway is regulated by BCL-2 family proteins and describe ways in which cancer cells can block it. Finally, we discuss exciting new approaches aimed at specifically inducing mitochondrial apoptosis in cancer cells, outlining their potential pitfalls, while highlighting their considerable therapeutic promise.
Collapse
|