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Yassin MA, Al-Rasheed M, Al-Khaboori M, Marashi M, Osman H, Wali Y, Al Kindi S, Alsayegh F, Provan D. Thrombopoietin-receptor agonists for adult patients with immune thrombocytopenia: a narrative review and an approach for managing patients fasting intermittently. Front Cardiovasc Med 2023; 10:1260487. [PMID: 38162126 PMCID: PMC10755910 DOI: 10.3389/fcvm.2023.1260487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction Thrombopoietin-receptor agonist (TPO-RAs) currently represent the state of art for treating immune thrombocytopenia. Their different molecular structures contribute to the difference in their pharmacodynamics and pharmacokinetics. This narrative review aims to provide an overview of the current TPO-RAs approved for primary immune thrombocytopenia (romiplostim, eltrombopag, avatrombopag) and the effect of intermittent fasting in adult patients receiving TPO-RAs. Areas covered Literature was searched with no limits on date or language, using various combinations of keywords. Data on the pharmacokinetics, pharmacodynamics, efficacy, and safety of TPO-RAs and the effect of intermittent fasting were summarized. Expert opinion Switching between TPO-RAs is a useful strategy to tackle some associated limitations. Romiplostim and avatrombopag have an advantage over eltrombopag as they do not require any dietary restrictions. In cases where romiplostim and avatrombopag are unavailable, patients should be educated on the appropriate administration, possible interactions, and dietary restrictions before initiating eltrombopag.
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Affiliation(s)
- Mohamed A. Yassin
- National Center for Cancer Care and Research, Hematology Section, Hamad Medical Corporation, Doha, Qatar
| | - Mona Al-Rasheed
- Hematology Unit, Department of Medicine, Al-Adan Hospital, Hadiya, Kuwait
| | | | - Mahmoud Marashi
- Dubai Academic Health Corporation, Dubai, United Arab Emirates
| | - Hani Osman
- Hematology-Oncology Department, Tawam Hospital, Abu Dhabi, United Arab Emirates
| | - Yasser Wali
- Department of Child Health, Sultan Qaboos University, Muscat, Oman
| | - Salam Al Kindi
- Department of Hematology, Sultan Qaboos University, Muscat, Oman
| | - Faisal Alsayegh
- Faculty of Medicine, Department of Medicine, Health Sciences Center, Kuwait University, Kuwait City, Kuwait
| | - Drew Provan
- Academic Haematology Unit, Blizard Institute, Barts and The London School of Medicine and Dentistry, London, United Kingdom
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2
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Tsiakalos A, Routsias JG, Schinas G, Georgiadou S, Sipsas NV, Akinosoglou K. Investigating the Role of Anti-TPO Antibodies in HIV-Associated Thrombocytopenia before and after Initiation of HAART: A Case-Control Longitudinal Study. Viruses 2023; 15:2226. [PMID: 38005902 PMCID: PMC10675467 DOI: 10.3390/v15112226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 10/31/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023] Open
Abstract
This longitudinal, case-control study aimed to investigate the role of thrombopoietin (TPO) and anti-TPO antibodies in HIV-associated thrombocytopenia, focusing on the changes seen before and after the initiation of highly active antiretroviral therapy (HAART). Patients were assessed before and at least six months after the initiation of HAART. In total, 75 PLWHIV (age/sex-matched and randomized at 2:1, according to thrombocytopenia status) were included in this study. The baseline assessment revealed significantly higher TPO levels in thrombocytopenic patients (140.45 vs. 106.8 mg/mL, p = 0.008). Furthermore, anti-TPO-positive patients displayed lower platelet counts (109,000 vs. 139,000/L, p = 0.002) and TPO levels (114.7 vs. 142.7 mg/mL, p = 0.047). Longitudinally, HAART initiation reduced the frequency of thrombocytopenia from 75.47% to 33.96% (p < 0.001) and elevated the median platelet counts from 131,000 to 199,000 (p < 0.001). No significant difference in median platelet counts was found post-HAART among the anti-TPO subgroups (p = 0.338), a result contrasting with pre-HAART findings (p = 0.043). Changes in anti-TPO status corresponded with significant platelet count alterations (p = 0.036). Notably, patients who became anti-TPO negative showed a median increase of 95,000 platelets (IQR: 43,750-199,500). These marked differences between subgroups underscore the potential role of anti-TPO antibodies in modulating the hematological response to HAART. Further research is needed to elucidate the complex interplay between HIV infection, HAART, and thrombocytopenia.
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Affiliation(s)
| | - John G. Routsias
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | | | - Sarah Georgiadou
- Department of Medicine and Research Laboratory of Internal Medicine, General University Hospital of Larissa, 41110 Larissa, Greece;
| | - Nikolaos V. Sipsas
- Laiko General Hospital of Athens and Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece;
| | - Karolina Akinosoglou
- School of Medicine, University of Patras, 26504 Rio, Greece;
- Department of Internal Medicine and Infectious Diseases, University General Hospital of Patras, 26504 Rio, Greece
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3
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Pirabe A, Frühwirth S, Brunnthaler L, Hackl H, Schmuckenschlager A, Schrottmaier WC, Assinger A. Age-Dependent Surface Receptor Expression Patterns in Immature Versus Mature Platelets in Mouse Models of Regenerative Thrombocytopenia. Cells 2023; 12:2419. [PMID: 37830633 PMCID: PMC10571991 DOI: 10.3390/cells12192419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/14/2023] Open
Abstract
Aging is a multifaceted process that unfolds at both the individual and cellular levels, resulting in changes in platelet count and platelet reactivity. These alterations are influenced by shifts in platelet production, as well as by various environmental factors that affect circulating platelets. Aging also triggers functional changes in platelets, including a reduction in RNA content and protein production capacity. Older individuals and RNA-rich immature platelets often exhibit hyperactivity, contributing significantly to pathologic conditions such as cardiovascular diseases, sepsis, and thrombosis. However, the impact of aging on surface receptor expression of circulating platelets, particularly whether these effects vary between immature and mature platelets, remains largely unexplored. Thus, we investigated the expression of certain surface and activation receptors on platelets from young and old mice as well as on immature and mature platelets from mouse models of regenerative thrombocytopenia by flow cytometry. Our findings indicate that aged mice show an upregulated expression of the platelet endothelial cell adhesion molecule-1 (CD31), tetraspanin-29 (CD9), and Toll-like receptor 2 (TLR2) compared to their younger counterparts. Interestingly, when comparing immature and mature platelets in both young and old mice, no differences were observed in mature platelets. However, immature platelets from young mice displayed higher surface expression compared to immature platelets from old mice. Additionally, in mouse models of regenerative thrombocytopenia, the majority of receptors were upregulated in immature platelets. These results suggest that distinct surface receptor expressions are increased on platelets from old mice and immature platelets, which may partially explain their heightened activity and contribute to an increased thrombotic risk.
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Affiliation(s)
- Anita Pirabe
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Sabine Frühwirth
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Laura Brunnthaler
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Hubert Hackl
- Institute of Bioinformatics, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Anna Schmuckenschlager
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Waltraud C. Schrottmaier
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - Alice Assinger
- Institute of Vascular Biology and Thrombosis Research, Center of Physiology and Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
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4
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Review on the Biogenesis of Platelets in Lungs and Its Alterations in SARS-CoV-2 Infection Patients. J Renin Angiotensin Aldosterone Syst 2023; 2023:7550197. [PMID: 36891250 PMCID: PMC9988383 DOI: 10.1155/2023/7550197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 01/28/2023] [Accepted: 02/08/2023] [Indexed: 03/01/2023] Open
Abstract
Thrombocytes (platelets) are the type of blood cells that are involved in hemostasis, thrombosis, etc. For the conversion of megakaryocytes into thrombocytes, the thrombopoietin (TPO) protein is essential which is encoded by the TPO gene. TPO gene is present in the long arm of chromosome number 3 (3q26). This TPO protein interacts with the c-Mpl receptor, which is present on the outer surface of megakaryocytes. As a result, megakaryocyte breaks into the production of functional thrombocytes. Some of the evidence shows that the megakaryocytes, the precursor of thrombocytes, are seen in the lung's interstitium. This review focuses on the involvement of the lungs in the production of thrombocytes and their mechanism. A lot of findings show that viral diseases, which affect the lungs, cause thrombocytopenia in human beings. One of the notable viral diseases is COVID-19 or severe acute respiratory syndrome caused by SARS-associated coronavirus 2 (SARS-CoV-2). SARS-CoV-2 caused a worldwide alarm in 2019 and a lot of people suffered because of this disease. It mainly targets the lung cells for its replication. To enter the cells, these virus targets the angiotensin-converting enzyme-2 (ACE-2) receptors that are abundantly seen on the surface of the lung cells. Recent reports of COVID-19-affected patients reveal the important fact that these peoples develop thrombocytopenia as a post-COVID condition. This review elaborates on the biogenesis of platelets in the lungs and the alterations of thrombocytes during the COVID-19 infection.
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Hernández-Cano L, Fernández-Infante C, Herranz Ó, Berrocal P, Lozano FS, Sánchez-Martín MA, Porras A, Guerrero C. New functions of C3G in platelet biology: Contribution to ischemia-induced angiogenesis, tumor metastasis and TPO clearance. Front Cell Dev Biol 2022; 10:1026287. [DOI: 10.3389/fcell.2022.1026287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 10/06/2022] [Indexed: 11/13/2022] Open
Abstract
C3G is a Rap1 guanine nucleotide exchange factor that controls platelet activation, aggregation, and the release of α-granule content. Transgenic expression of C3G in platelets produces a net proangiogenic secretome through the retention of thrombospondin-1. In a physiological context, C3G also promotes megakaryocyte maturation and proplatelet formation, but without affecting mature platelet production. The aim of this work is to investigate whether C3G is involved in pathological megakaryopoiesis, as well as its specific role in platelet mediated angiogenesis and tumor metastasis. Using megakaryocyte-specific C3G knockout and transgenic mouse models, we found that both C3G overexpression and deletion promoted platelet-mediated angiogenesis, induced by tumor cell implantation or hindlimb ischemia, through differential release of proangiogenic and antiangiogenic factors. However, only C3G deletion resulted in a higher recruitment of hemangiocytes from the bone marrow. In addition, C3G null expression enhanced thrombopoietin (TPO)-induced platelet production, associated with reduced TPO plasma levels. Moreover, after 5-fluorouracil-induced platelet depletion and rebound, C3G knockout mice showed a defective return to homeostatic platelet levels, indicating impaired platelet turnover. Mechanistically, C3G promotes c-Mpl ubiquitination by inducing Src-mediated c-Cbl phosphorylation and participates in c-Mpl degradation via the proteasome and lysosome systems, affecting TPO internalization. We also unveiled a positive role of platelet C3G in tumor cell-induced platelet aggregation, which facilitated metastatic cell homing and adhesion. Overall, these findings revealed that C3G plays a crucial role in platelet-mediated angiogenesis and metastasis, as well as in platelet level modulation in response to pathogenic stimuli.
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6
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Prospective validation of a biomarker-driven response prediction model to romiplostim in lower-risk myelodysplastic neoplasms - results of the EUROPE trial by EMSCO. Leukemia 2022; 36:2519-2527. [PMID: 36071100 PMCID: PMC9522582 DOI: 10.1038/s41375-022-01669-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/18/2022] [Accepted: 07/25/2022] [Indexed: 11/10/2022]
Abstract
The EUROPE phase 2 trial investigated the predictive value of biomarkers on the clinical efficacy of single agent romiplostim (ROM) treatment in patients with lower-risk myelodysplastic neoplasms (LR-MDS) and thrombocytopenia within the ‘European Myelodysplastic Neoplasms Cooperative Group‘ (EMSCO) network. A total of 77 patients with LR-MDS and a median platelet count of 25/nl were included, all patients received ROM at a starting dose of 750 μg by SC injection weekly. Thirty-two patients (42%) achieved a hematologic improvement of platelets (HI-P) with a median duration of 340 days. Neutrophil (HI-N) and erythroid (HI-E) responses were observed in three (4%) and seven (9%) patients, respectively. We could not confirm previous reports that HI-P correlated with baseline endogenous thrombopoietin levels and platelet transfusion history, but SRSF2 mutation status and hemoglobin levels at baseline were significantly linked to HI-P. Sequential analysis of variant allelic frequency of mutations like SRSF2 did not reveal an impact of ROM on clonal evolution in both responders and non-responders. In summary, our study confirms the safety and efficacy of ROM in LR-MDS patients and may allow to better define subgroups of patients with a high likelihood of response.
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Abstract
Classically, platelets have been described as the cellular blood component that mediates hemostasis and thrombosis. This important platelet function has received significant research attention for >150 years. The immune cell functions of platelets are much less appreciated. Platelets interact with and activate cells of all branches of immunity in response to pathogen exposures and infection, as well as in response to sterile tissue injury. In this review, we focus on innate immune mechanisms of platelet activation, platelet interactions with innate immune cells, as well as the intersection of platelets and adaptive immunity. The immune potential of platelets is dependent in part on their megakaryocyte precursor providing them with the molecular composition to be first responders and immune sentinels in initiating and orchestrating coordinated pathogen immune responses. There is emerging evidence that extramedullary megakaryocytes may be immune differentiated compared with bone marrow megakaryocytes, but the physiological relevance of immunophenotypic differences are just beginning to be explored. These concepts are also discussed in this review. The immune functions of the megakaryocyte/platelet lineage have likely evolved to coordinate the need to repair a vascular breach with the simultaneous need to induce an immune response that may limit pathogen invasion once the blood is exposed to an external environment.
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Affiliation(s)
- Milka Koupenova
- Department of Medicine, Division of Cardiovascular Medicine, University of Massachusetts Chan Medical School, 368 Plantation Street, Worcester, MA 01605
| | - Alison Livada
- Aab Cardiovascular Research Institute, University of Rochester Medical Center, Rochester, NY 14642
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642
| | - Craig N. Morrell
- Aab Cardiovascular Research Institute, University of Rochester Medical Center, Rochester, NY 14642
- Department of Medicine, University of Rochester Medical Center, Rochester, NY 14642
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY 14642
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642
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8
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Erythropoietin receptor contributes to thrombopoietin receptor (Mpl)-independent thrombocytopoiesis in zebrafish. Leukemia 2022; 36:1193-1197. [PMID: 35039636 DOI: 10.1038/s41375-021-01495-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/01/2021] [Accepted: 12/08/2021] [Indexed: 11/08/2022]
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9
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Huang W, Gu H, Zhan Z, Wang R, Song L, Zhang Y, Zhang Y, Li S, Li J, Zang Y, Li Y, Qian B. The plant hormone abscisic acid stimulates megakaryocyte differentiation from human iPSCs in vitro. Platelets 2021; 33:462-470. [PMID: 34223794 DOI: 10.1080/09537104.2021.1944616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In the clinic, the supply of platelets is frequently insufficient to meet transfusion needs. To address this issue, many scientists have established the derivation of functional platelets from CD34+ cells or human pluripotent stem cells (PSCs). However, the yield of platelets is still far below what is required. Here we found that the plant hormone abscisic acid (ABA) could increase the generation of megakaryocytes (MKs) and platelets from human induced PSCs (hiPSCs). During platelet derivation, ABA treatment promoted the generation of CD34+/CD45+ HPCs and CD41+ MKs on day 14 and then increased CD41+/CD42b+ MKs and platelets on day 19. Moreover, we found ABA-mediated activation of Akt and ERK1/2 signal pathway through receptors LANCL2 and GRP78 in a PKA-dependent manner on CD34+/CD45+ cells. In conclusion, our data suggest that ABA treatment can promote CD34+/CD45+ HPC proliferation and CD41+ MK differentiation.
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Affiliation(s)
- Weihua Huang
- Department of Transfusion Medicine, The First Affiliated Hospital of Naval Medical University, Shanghai China.,Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Haihui Gu
- Department of Transfusion Medicine, The First Affiliated Hospital of Naval Medical University, Shanghai China
| | - Zhiyan Zhan
- Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Ruoru Wang
- Department of Neurology, The First Affiliated Hospital of Naval Medical University, Shanghai China
| | - Lili Song
- Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Yan Zhang
- Department of Hematology, The First Affiliated Hospital of Naval Medical University, Shanghai China
| | - Yingwen Zhang
- Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Shanshan Li
- Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Jinqi Li
- Department of Transfusion Medicine, The First Affiliated Hospital of Naval Medical University, Shanghai China
| | - Yan Zang
- Department of Transfusion Medicine, The First Affiliated Hospital of Naval Medical University, Shanghai China
| | - Yanxin Li
- Department of Hematology & Oncology, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, National Health Committee Key Laboratory of Pediatric Hematology & Oncology, Shanghai, China
| | - Baohua Qian
- Department of Transfusion Medicine, The First Affiliated Hospital of Naval Medical University, Shanghai China
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10
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Gómez-Almaguer D. Commentary on: First-in-patient study of hetrombopag in patients with chronic idiopathic thrombocytopenic purpura. J Thromb Haemost 2020; 18:2826-2827. [PMID: 33463016 DOI: 10.1111/jth.15077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 08/18/2020] [Indexed: 11/30/2022]
Affiliation(s)
- David Gómez-Almaguer
- Hematology Service, Facultad de Medicina y Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, Monterrey, México
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11
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Märklin M, Tandler C, Kopp HG, Hoehn KL, Quintanilla-Martinez L, Borst O, Müller MR, Saur SJ. C-Cbl regulates c-MPL receptor trafficking and its internalization. J Cell Mol Med 2020; 24:12491-12503. [PMID: 32954656 PMCID: PMC7687000 DOI: 10.1111/jcmm.15785] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 01/11/2023] Open
Abstract
Thrombocyte formation from megakaryocyte and their progenitor cells is tightly regulated by thrombopoietin (TPO) and its receptor c‐MPL, thereby maintaining physiological functionality and numbers of circulating platelets. In patients, dysfunction of this regulation could cause thrombocytopenia or myeloproliferative syndromes. Since regulation of this pathway is still not completely understood, we investigated the role of the ubiquitin ligase c‐Cbl which was previously shown to negatively regulated c‐MPL signalling. We developed a new conditional mouse model using c‐Cblfl/flPf4Cre mice and demonstrated that platelet‐specific knockout of c‐Cbl led to severe microthrombocytosis and impaired uptake of TPO and c‐MPL receptor internalization. Furthermore, we characterized a constitutive STAT5 activation c‐Cbl KO platelets. This study identified c‐Cbl as a potential player in causing megakaryocytic and thrombocytic disorders.
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Affiliation(s)
- Melanie Märklin
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), German Cancer Research Centre (DKFZ), University Hospital Tübingen, Tübingen, Germany
| | - Claudia Tandler
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), German Cancer Research Centre (DKFZ), University Hospital Tübingen, Tübingen, Germany
| | - Hans-Georg Kopp
- Department of Molecular Oncology and Thoracic Oncology, Robert-Bosch-Hospital Stuttgart, Stuttgart, Germany
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | | | - Oliver Borst
- Department of Kardiology and Angiology, University Hospital Tübingen, Tübingen, Germany
| | - Martin R Müller
- Department of Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany.,Department of Hematology, Oncology and Immunology, Klinikum Region Hannover, KRH Klinikum Siloah, Hannover, Germany
| | - Sebastian J Saur
- Department of Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany
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Zhou CL, Su HL, Dai HW. Thrombopoietin is associated with a prognosis of gastric adenocarcinoma. ACTA ACUST UNITED AC 2020; 66:590-595. [PMID: 32638965 DOI: 10.1590/1806-9282.66.5.590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/10/2019] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Thrombopoietin (THPO) is well-known as a megakaryocyte growth and development factor (MGDF) involved in megakaryocyte proliferation and maturation. To explore the biological effects of THPO in gastric adenocarcinoma, we conducted this study. Methods: By accessing the TCGA database, the expression level of THPO was determined in tumor tissues. The association between THPO expression and clinical features, or prognostic significance was described by Cox regression analysis and Kaplan-Meier. The SiRNA method was used to decline the THPO expression; then cell viability, invasion, and migration were detected to verify the effects of the knockdown of THPO. qPCR and western blotting were implemented to examine the expression level of THPO. Results: The expression of THPO was increased in tumor tissue and cells, its high-regulation was associated with a poor prognosis in patients with gastric adenocarcinoma. Cell viability, invasion, and migration were suppressed in AGS with the down-regulation of THPO. Furthermore, on the basis of si-THPO transfection, E-cadherin was promoted while N-cadherin and Vimentin were attenuated. CONCLUSION Our results revealed that THPO may be a potent marker of gastric adenocarcinoma, providing a novel potential screening method for gastric adenocarcinoma.
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Affiliation(s)
| | - Hai-Long Su
- Department of General Surgery, Yantai Yuhuangding Hospital, Qingdao University, Yantai, Shandong, China
| | - Hong-Wei Dai
- Department of Blood Transfusion, Suizhou Central Hospital, Hubei University of Medicine, Suizhou, Hubei, China
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13
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Bussel J, Kulasekararaj A, Cooper N, Verma A, Steidl U, Semple JW, Will B. Mechanisms and therapeutic prospects of thrombopoietin receptor agonists. Semin Hematol 2019; 56:262-278. [PMID: 31836033 DOI: 10.1053/j.seminhematol.2019.09.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 07/30/2019] [Accepted: 09/30/2019] [Indexed: 12/13/2022]
Abstract
The second-generation thrombopoietin (TPO) receptor agonists eltrombopag and romiplostim are potent activators of megakaryopoiesis and represent a growing treatment option for patients with thrombocytopenic hematological disorders. Both TPO receptor agonists have been approved worldwide for the treatment of children and adults with chronic immune thrombocytopenia. In the EU and USA, eltrombopag is approved for the treatment of patients with severe aplastic anemia who have had an insufficient response to immunosuppressive therapy and in the USA for the first-line treatment of severe aplastic anemia in combination with immunosuppressive therapy. Eltrombopag has also shown efficacy in several other disease settings, for example, chemotherapy-induced thrombocytopenia, selected inherited thrombocytopenias, and myelodysplastic syndromes. While both TPO receptor agonists stimulate TPO receptor signaling and enhance megakaryopoiesis, their vastly different biochemical structures bestow upon them markedly different molecular and functional properties. Here, we review and discuss results from preclinical and clinical studies on the functional and molecular mechanisms of action of this new class of drug.
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Affiliation(s)
- James Bussel
- Pediatric Hematology/Oncology, Weill Cornell Medicine, New York, NY.
| | | | | | - Amit Verma
- Albert Einstein College of Medicine, New York, NY
| | | | - John W Semple
- Division of Hematology and Transfusion Medicine, Lund University, Lund, Sweden
| | - Britta Will
- Albert Einstein College of Medicine, New York, NY.
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14
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Kim J, Jin G, Lee J, Lee K, Bae YS, Kim J. 2-(trimethylammonium)ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate enhances thrombopoietin–induced megakaryocytic differentiation and plateletogenesis. BMB Rep 2019. [PMID: 30670147 PMCID: PMC6675245 DOI: 10.5483/bmbrep.2019.52.7.200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
We have previously reported the effects of 2-(trimethylammonium) ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a synthetic phospholipid, on megakaryocytic differentiation of myeloid leukemia cells. Here, we demonstrate that (R)-TEMOSPho enhances megakaryopoiesis and plateletogenesis from primary hematopoietic stem cells (HSCs) induced by thrombopoietin (TPO). Specifically, we demonstrate at sub-saturation levels of TPO, the addition of (R)-TEMOSPho enhances differentiation and maturation of megakaryocytes (MKs) from murine HSCs derived from fetal liver. Furthermore, we show that production of platelets with (R)-TEMOSPho in combination with TPO is also more efficient than TPO alone and that platelets generated in vitro with these two agents are as functional as those from TPO alone. TPO can thus be partly replaced by or supplemented with (R)-TEMOSPho, and this in turn implies that (R)-TEMOSPho can be useful in efficient platelet production in vitro and potentially be a valuable option in designing cell-based therapy.
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Affiliation(s)
- Jusong Kim
- Department of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Guanghai Jin
- College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | - Jisu Lee
- College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | - Kyeong Lee
- College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | - Yun Soo Bae
- Department of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Jaesang Kim
- Department of Life Science, Ewha Womans University, Seoul 03760, Korea
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15
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Li C, Li X, Huang F, Yang J, Wu A, Wang L, Qin D, Zou W, Wu J. Efficacy and Safety of Avatrombopag in Patients With Thrombocytopenia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Front Pharmacol 2019; 10:829. [PMID: 31402863 PMCID: PMC6677019 DOI: 10.3389/fphar.2019.00829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/27/2019] [Indexed: 01/04/2023] Open
Abstract
Background: Avatrombopag is a novel oral, nonpeptide thrombopoietin receptor agonist (TPO-RA). A few studies have shown that avatrombopag is effective against thrombocytopenia. However, no systematic review has been conducted on the efficacy and safety of avatrombopag. Therefore, the aim of this study was to comprehensively assess the efficacy and safety of avatrombopag patients with thrombocytopenia. Methods: Databases including Medline, PubMed, Embase, the Cochrane Library and ClinicalTrials.gov were searched for randomized controlled trials that compared avatrombopag with placebo in patients with thrombocytopenia. The deadline was March 2019. Results: In total, 743 patients were analyzed in five clinical trials. Patients treated with avatrombopag achieved higher platelet response (OR: 17.71, 95% CI [11.01 to 28.48], p < 0.00001) than with placebo. Avatrombopag produced an absolute increment in platelet count (WMD: 31.13%, 95% CI [22.27 to 39.99], p < 0.00001) unlike the placebo. In addition, the incidence of serious adverse events (RR: 1.18, 95% CI [0.72 to 1.93], p = 0.51) and deaths (RR: 0.93, 95% CI [0.19 to 4.45], p = 0.93) in patients treated with avatrombopag was not significantly different from that in patients treated with placebo. The incidence of adverse events in patients treated with avatrombopag was slightly higher than that in patients treated with placebo (RR: 1.25, 95% CI [1.05 to 1.49], p = 0. 01) after one trial with high heterogeneity was removed. Conclusions: This meta-analysis showed that avatrombopag was an effective treatment for thrombocytopenia, but there is sufficient evidence to indicate that adverse events may occur.
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Affiliation(s)
- Chunlu Li
- Department of Chinese Materia Medica, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China.,Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China
| | - Xiaoxuan Li
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Department of Pharmacy, The Second People's Hospital of Yibin, Yibin, China
| | - Feihong Huang
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China
| | - Jing Yang
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China
| | - Anguo Wu
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China
| | - Long Wang
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China
| | - Dalian Qin
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China
| | - Wenjun Zou
- Department of Chinese Materia Medica, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Jianming Wu
- Laboratory of Chinese Materia Medica, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, China.,Institute of Cardiovascular Research, The Key Laboratory of Medical Electrophysiology, Ministry of Education of China, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease of Sichuan Province, Medical Key Laboratory for Drug Discovery and Druggability Evaluation of Sichuan Province, Luzhou Key Laboratory of Activity Screening and Druggability Evaluation for Chinese Materia Medica, Luzhou, China.,Department of Pharmacy, Affiliated Hospital of Southwest Medical University, Luzhou, China
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16
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Derakhshani M, Abbaszadeh H, Movassaghpour AA, Mehdizadeh A, Ebrahimi-Warkiani M, Yousefi M. Strategies for elevating hematopoietic stem cells expansion and engraftment capacity. Life Sci 2019; 232:116598. [PMID: 31247209 DOI: 10.1016/j.lfs.2019.116598] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 06/22/2019] [Accepted: 06/23/2019] [Indexed: 02/07/2023]
Abstract
Hematopoietic stem cells (HSCs) are a rare cell population in adult bone marrow, mobilized peripheral blood, and umbilical cord blood possessing self-renewal and differentiation capability into a full spectrum of blood cells. Bone marrow HSC transplantation has been considered as an ideal option for certain disorders treatment including hematologic diseases, leukemia, immunodeficiency, bone marrow failure syndrome, genetic defects such as thalassemia, sickle cell anemia, autoimmune disease, and certain solid cancers. Ex vivo proliferation of these cells prior to transplantation has been proposed as a potential solution against limited number of stem cells. In such culture process, MSCs have also been shown to exhibit high capacity for secretion of soluble mediators contributing to the principle biological and therapeutic activities of HSCs. In addition, endothelial cells have been introduced to bridge the blood and sub tissues in the bone marrow, as well as, HSCs regeneration induction and survival. Cell culture in the laboratory environment requires cell growth strict control to protect against contamination, symmetrical cell division and optimal conditions for maximum yield. In this regard, microfluidic systems provide culture and analysis capabilities in micro volume scales. Moreover, two-dimensional cultures cannot fully demonstrate extracellular matrix found in different tissues and organs as an abstract representation of three dimensional cell structure. Microfluidic systems can also strongly describe the effects of physical factors such as temperature and pressure on cell behavior.
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Affiliation(s)
- Mehdi Derakhshani
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Abbaszadeh
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Ali Akbar Movassaghpour
- Hematology and Oncology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Mehdizadeh
- Endocrine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Majid Ebrahimi-Warkiani
- School of Biomedical Engineering, University Technology of Sydney, Sydney, New South Wales, 2007, Australia
| | - Mehdi Yousefi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Aging Research Institute, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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17
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18
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Wilcox DA. Gene Therapy for Platelet Disorders. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00067-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Dhenge A, Kuhikar R, Kale V, Limaye L. Regulation of differentiation of MEG01 to megakaryocytes and platelet-like particles by Valproic acid through Notch3 mediated actin polymerization. Platelets 2018; 30:780-795. [PMID: 30332548 DOI: 10.1080/09537104.2018.1528344] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Valproic acid (VPA) is one of the HDAC inhibitors used for the treatment of neurological disorders and hematological malignancies. Its role in self-renewal and proliferation of hematopoietic stem cells (HSCs) is well studied, but little is known about its involvement in regulating megakaryopoiesis and thrombopoiesis. In this study, we evaluated the role of VPA in megakaryopoiesis by using MEG-01, a megakaryoblast cell line. Our results show that VPA treatment differentiates MEG-01 cells to megakaryocytes (MK) and platelet-like particles. It was confirmed by augmented expression of MK and PLT-specific markers, higher ploidy, and PLT functionality. We assessed the molecular events underlying megakaryopoiesis. In the present study, we found an upregulation of Notch3 and its downstream target PDGFR-β upon VPA treatment. The direct role of Notch3 in megakaryopoiesis has not yet been studied. PDGFR-β is known to control actin organization during vascular smooth muscle cell differentiation. The actin cytoskeleton plays important role during proplatelet and PLT formation. We found an upregulation of Rac/Cdc42 GTPase and its downstream effectors that are the key players during actin polymerization events. We speculate that VPA induces PLT formation through Notch-3 signaling that in turn modulates actin polymerization that is one of the crucial steps necessary for thrombopoiesis. These studies were also confirmed with knockdown of Notch3 in MEG01 by using ShRNA approach as well as with apheresis-derived CD34+ cells. Altogether, these findings provide an evidence for a novel role of Notch3 in regulating platelet formation.
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Affiliation(s)
- Ankita Dhenge
- a National Centre for Cell Science, NCCS Complex , Savitribai Phule Pune University Campus , Pune , India
| | - Rutuja Kuhikar
- a National Centre for Cell Science, NCCS Complex , Savitribai Phule Pune University Campus , Pune , India
| | - Vaijayanti Kale
- a National Centre for Cell Science, NCCS Complex , Savitribai Phule Pune University Campus , Pune , India
| | - Lalita Limaye
- a National Centre for Cell Science, NCCS Complex , Savitribai Phule Pune University Campus , Pune , India
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20
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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: 21] [Impact Index Per Article: 3.5] [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.
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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
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21
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Spina P, Impera S, Todaro AM, Salerno M, Floridia PM, Castagna F, Consoli U. “On-demand” treatment with Thrombopoietin mimetics as “bridge to recovery” from chemotherapy in chronic immune thrombocytopenia patients with cancer. A single centre experience in nine patients. Br J Haematol 2018; 181:400-403. [DOI: 10.1111/bjh.14605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paolo Spina
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Stefana Impera
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Anna Maria Todaro
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Marilena Salerno
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Pietro Michele Floridia
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Fabrizio Castagna
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
| | - Ugo Consoli
- UOC di Ematologia; Azienda Ospedaliera di Rilievo Nazionale e di Alta Specializzazione Garibaldi; Catania Italy
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22
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Yoshida H, Yamada H, Nogami W, Dohi K, Kurino-Yamada T, Sugiyama K, Takahashi K, Gahara Y, Kitaura M, Hasegawa M, Oshima I, Kuwabara K. Development of a new knock-in mouse model and evaluation of pharmacological activities of lusutrombopag, a novel, nonpeptidyl small-molecule agonist of the human thrombopoietin receptor c-Mpl. Exp Hematol 2017; 59:30-39.e2. [PMID: 29274361 DOI: 10.1016/j.exphem.2017.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/15/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
Lusutrombopag (S-888711), an oral small-molecule thrombopoietin receptor (TPOR) agonist, has gained first approval as a drug to treat thrombocytopenia of chronic liver disease in patients undergoing elective invasive procedures in Japan. Preclinical studies were performed to evaluate its efficacy against megakaryopoiesis and thrombopoiesis. To investigate the proliferative activity and efficacy of megakaryocytic colony formation via human TPOR, lusutrombopag was applied to cultured human c-Mpl-expressing Ba/F3 (Ba/F3-hMpl) cells and human bone marrow-derived CD34-positive cells, respectively. Lusutrombopag caused a robust increase in Ba/F3-hMpl cells by activating pathways in a manner similar to that of thrombopoietin and induced colony-forming units-megakaryocyte and polyploid megakaryocytes in human CD34-positive cells. Because lusutrombopag has high species specificity for human TPOR, there was no suitable experimental animal model for drug evaluation, except for immunodeficient mouse-based xenograft models. Therefore, a novel genetically modified knock-in mouse, TPOR-Ki/Shi, was developed by replacing mouse Mpl with human-mouse chimera Mpl. In TPOR-Ki/Shi mice, lusutrombopag significantly increased circulating platelets in a dose-dependent manner during 21-day repeated oral administration. Histopathological study of the TPOR-Ki/Shi mice on day 22 also revealed a significant increase in megakaryocytes in the bone marrow. These results indicate that lusutrombopag acts on human TPOR to upregulate differentiation and proliferation of megakaryocytic cells, leading to platelet production.
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Affiliation(s)
- Hiroshi Yoshida
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Hajime Yamada
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Wataru Nogami
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Keiji Dohi
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | | | - Koji Sugiyama
- Human Resources & Administration Department, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Koji Takahashi
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Yoshinari Gahara
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Motoji Kitaura
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Minoru Hasegawa
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Itsuki Oshima
- Pharmaceutical Research Division, Human Resources & Administration Department, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan
| | - Kenji Kuwabara
- Drug Discovery & Disease Research Laboratory, Shionogi & Co., Ltd., Toyonaka City, Osaka, Japan.
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23
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Zheng L, Liang MZ, Zeng XL, Li CZ, Zhang YF, Chen XY, Zhu X, Xiang AB. Safety, Pharmacokinetics and Pharmacodynamics of Hetrombopag Olamine, a Novel TPO-R Agonist, in Healthy Individuals. Basic Clin Pharmacol Toxicol 2017; 121:414-422. [PMID: 28544774 DOI: 10.1111/bcpt.12815] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/04/2017] [Indexed: 02/05/2023]
Abstract
Hetrombopag olamine (hetrombopag) is a novel small-molecule, orally bioavailable, non-peptide thrombopoietin (TPO) receptor agonist that is being developed as the treatment for thrombocytopenia. Two randomized, placebo-controlled phase I studies were conducted in 72 healthy individuals to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of hetrombopag. Hetrombopag was orally administered with a single dose in five dose cohorts (5 mg, 10 mg, 20 mg, 30 mg or 40 mg) in the first study, and given once daily for 10 days in three dose cohorts (2.5 mg, 5.0 mg or 7.5 mg) in the second study, respectively. Hetrombopag was well tolerated, and the majority of adverse events associated with medicine were platelet elevations significantly above the normal range in healthy individuals. The single dose-escalation study revealed a Tmax of approximate 8 hr, and a t1/2 of 11.9 hr to 40.1 hr in a dose-prolonged manner. A dose-proportional increase in maximum concentration (Cmax ) of hetrombopag was observed, with area under the curve (AUC) increasing in a greater than dose-proportional manner. The plasma concentration of hetrombopag reached the steady-state after 7 days. The steady-state AUC0-24 hr and Cmax were dose-proportionally elevated from the 5.0 mg to 7.5 mg dose level. The potent pharmacological effect of the hetrombopag-induced platelet elevation was observed in a time- and dose-dependent manner. Furthermore, the thrombopoietic response was significantly (p < 0.0001) correlated to the plasma exposure level of hetrombopag in single and multiple administration studies. Taken together, results of this study support further clinical development of hetrombopag in patients with thrombocytopenia.
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Affiliation(s)
- Li Zheng
- Institute of Clinical Pharmacology, West China Hospital of Sichuan University, Chengdu, China
| | - Mao-Zhi Liang
- Institute of Clinical Pharmacology, West China Hospital of Sichuan University, Chengdu, China
| | - Xiao-Ling Zeng
- Department of Clinical Research, Jiangsu Hengrui Medicine Co., LTD., Shanghai, China
| | - Cai-Zheng Li
- Institute of Clinical Pharmacology, West China Hospital of Sichuan University, Chengdu, China
| | - Yi-Fan Zhang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xiao-Yan Chen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Xi Zhu
- Department of Clinical Research, Jiangsu Hengrui Medicine Co., LTD., Shanghai, China
| | - An-Bo Xiang
- Department of Clinical Research, Jiangsu Hengrui Medicine Co., LTD., Shanghai, China
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24
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Establishment of a congenital amegakaryocytic thrombocytopenia model and a thrombocyte–specific reporter line in zebrafish. Leukemia 2016; 31:1206-1216. [DOI: 10.1038/leu.2016.320] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/06/2016] [Accepted: 10/10/2016] [Indexed: 11/08/2022]
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25
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Han SH, Kim J, Her Y, Seong I, Park S, Bhattarai D, Jin G, Lee K, Chung G, Hwang S, Bae YS, Kim J. Phytosphingosine promotes megakaryocytic differentiation of myeloid leukemia cells. BMB Rep 2016; 48:691-5. [PMID: 26077028 PMCID: PMC4791325 DOI: 10.5483/bmbrep.2015.48.12.100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 12/25/2022] Open
Abstract
We report that phytosphingosine, a sphingolipid found in many organisms and implicated in cellular signaling, promotes megakaryocytic differentiation of myeloid leukemia cells. Specifically, phytosphingosine induced several hallmark changes associated with megakaryopoiesis from K562 and HEL cells including cell cycle arrest, cell size increase and polyploidization. We also confirmed that cell type specific markers of megakaryocytes, CD41a and CD42b are induced by phytosphingosine. Phospholipids with highly similar structures were unable to induce similar changes, indicating that the activity of phytosphingosine is highly specific. Although phytosphingosine is known to activate p38 mitogen-activated protein kinase (MAPK)-mediated apoptosis, the signaling mechanisms involved in megakaryopoiesis appear to be distinct. In sum, we present another model for dissecting molecular details of megakaryocytic differentiation which in large part remains obscure. [BMB Reports 2015; 48(12): 691-695]
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Affiliation(s)
- Sang Hee Han
- Departments of 1Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Jusong Kim
- Departments of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Yerim Her
- Departments of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Ikjoo Seong
- Departments of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Sera Park
- Bio-informatics Science, Ewha Womans University, Seoul 03760, Korea
| | - Deepak Bhattarai
- BK21 Plus R-FIND Team, College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | - Guanghai Jin
- BK21 Plus R-FIND Team, College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | - Kyeong Lee
- BK21 Plus R-FIND Team, College of Pharmacy, Dongguk University, Goyang 10326, Korea
| | | | | | - Yun Soo Bae
- Departments of Life Science, Ewha Womans University, Seoul 03760, Korea
| | - Jaesang Kim
- Departments of Life Science, Ewha Womans University, Seoul 03760, Korea
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26
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Abstract
OBJECTIVES Classically, immune thrombocytopenia (ITP) was thought to be caused by the destruction and insufficient production of platelets, as mediated by autoantibodies. More recently other immune mechanisms that contribute to the disease have been discovered. This review attempts to address the main unresolved questions in ITP. METHODS We review the most current knowledge of the pathophysiology of ITP. Immunological effects of available therapies are also described. DISCUSSION The trigger may be a loss of tolerance due to molecular mimicry with cross-reaction of antibodies arising from infectious agents or drugs, genetic factors, and/or platelet Toll receptors. This loss of tolerance activates autoreactive effector B and T lymphocytes, which in turn initiates platelet destruction, mediated by cytotoxic T lymphocytes and the release of pro-inflammatory cytokines (IL-2/IL-17) by T helper (Th) cells (Th1/Th17). Th2 (anti-inflammatory) and regulatory B (Breg) and Treg cells are also inhibited (with decrease in IL-10/TGF-β), which leads to the disease becoming chronic. Some isotypes of autoantibodies may increase the bleeding risk. Corticosteroids, rituximab, and thrombopoietin receptor agonists (A-TPOs) all increase levels of Tregs and TGF-β. The A-TPOs also increase Breg levels, which could explain why complete remission has been seen in some cases. CONCLUSION A better understanding of the immunomodulatory effects of each ITP therapy is needed to best manage the disease.
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Affiliation(s)
- María Perera
- a Haematology Service , University Hospital Doctor Negrín , Las Palmas de Gran Canaria, Spain
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27
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Megakaryocyte- and megakaryocyte precursor-related gene therapies. Blood 2016; 127:1260-8. [PMID: 26787735 DOI: 10.1182/blood-2015-07-607937] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/30/2015] [Indexed: 01/27/2023] Open
Abstract
Hematopoietic stem cells (HSCs) can be safely collected from the body, genetically modified, and re-infused into a patient with the goal to express the transgene product for an individual's lifetime. Hematologic defects that can be corrected with an allogeneic bone marrow transplant can theoretically also be treated with gene replacement therapy. Because some genetic disorders affect distinct cell lineages, researchers are utilizing HSC gene transfer techniques using lineage-specific endogenous gene promoters to confine transgene expression to individual cell types (eg, ITGA2B for inherited platelet defects). HSCs appear to be an ideal target for platelet gene therapy because they can differentiate into megakaryocytes which are capable of forming several thousand anucleate platelets that circulate within blood vessels to establish hemostasis by repairing vascular injury. Platelets play an essential role in other biological processes (immune response, angiogenesis) as well as diseased states (atherosclerosis, cancer, thrombosis). Thus, recent advances in genetic manipulation of megakaryocytes could lead to new and improved therapies for treating a variety of disorders. In summary, genetic manipulation of megakaryocytes has progressed to the point where clinically relevant strategies are being developed for human trials for genetic disorders affecting platelets. Nevertheless, challenges still need to be overcome to perfect this field; therefore, strategies to increase the safety and benefit of megakaryocyte gene therapy will be discussed.
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28
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Kurokawa T, Murata S, Zheng YW, Iwasaki K, Kohno K, Fukunaga K, Ohkohchi N. The Eltrombopag antitumor effect on hepatocellular carcinoma. Int J Oncol 2015; 47:1696-702. [PMID: 26397763 PMCID: PMC4599203 DOI: 10.3892/ijo.2015.3180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/21/2015] [Indexed: 12/13/2022] Open
Abstract
Currently, sorafenib is the only available chemotherapeutic agent for advanced hepatocellular carcinoma (HCC), but it cannot be used in patients with liver cirrhosis (LC) or thrombocytopenia. In these cases, sorafenib is likely effective if given in combination with treatments that increase the number of platelets, such as thrombopoietin (TPO) receptor agonists. Increasing the platelet count via TPO treatment resulted in reduction of LC. Eltrombopag (EP), a TPO receptor agonist, has been reported to have antitumor effects against certain cancers, despite their lack of TPO receptor expression. We hypothesized that EP may possess antitumor activity against HCC in addition to its ability to suppress hepatic fibrosis by increasing the platelet count. In the present study, the antitumor activity of EP was examined by assessing the inhibition of cell proliferation and then ascertaining the ability of iron supplementation to reverse these effects in HepG2, Hep3B and Huh7 cells. In addition, a cell cycle assay was performed using flow cytometry, and signal transduction was evaluated by analyzing cell cycle-related protein expression. The results of EP were compared with those of the most common iron chelator, deferoxamine (DFO). The combined effect of EP and sorafenib was also assessed. The results revealed that EP exerts antitumor activity in HCC that is mediated by the modulation of intracellular iron content. EP suppressed the expression of the cell cycle-related protein cyclin D1 and elicited cell cycle arrest in the G0/G1 phase. The activity of EP was comparable to that of DFO in HCC, and EP did not compete with sorafenib at low concentrations. In conclusion, our findings suggest that EP is a good candidate chemotherapeutic agent for the treatment of HCC in patients with LC and thrombocytopenia.
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Affiliation(s)
- Tomohiro Kurokawa
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Soichiro Murata
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Yun-Wen Zheng
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kenichi Iwasaki
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Keisuke Kohno
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Kiyoshi Fukunaga
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | - Nobuhiro Ohkohchi
- Department of Surgery, Division of Gastroenterological and Hepatobiliary Surgery, and Organ Transplantation, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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Merli P, Strocchio L, Vinti L, Palumbo G, Locatelli F. Eltrombopag for treatment of thrombocytopenia-associated disorders. Expert Opin Pharmacother 2015; 16:2243-56. [DOI: 10.1517/14656566.2015.1085512] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dorn DC, Dorn A. Stem cell autotomy and niche interaction in different systems. World J Stem Cells 2015; 7:922-944. [PMID: 26240680 PMCID: PMC4515436 DOI: 10.4252/wjsc.v7.i6.922] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 05/27/2015] [Indexed: 02/06/2023] Open
Abstract
The best known cases of cell autotomy are the formation of erythrocytes and thrombocytes (platelets) from progenitor cells that reside in special niches. Recently, autotomy of stem cells and its enigmatic interaction with the niche has been reported from male germline stem cells (GSCs) in several insect species. First described in lepidopterans, the silkmoth, followed by the gipsy moth and consecutively in hemipterans, foremost the milkweed bug. In both, moths and the milkweed bug, GSCs form finger-like projections toward the niche, the apical cells (homologs of the hub cells in Drosophila). Whereas in the milkweed bug the projection terminals remain at the surface of the niche cells, in the gipsy moth they protrude deeply into the singular niche cell. In both cases, the projections undergo serial retrograde fragmentation with progressing signs of autophagy. In the gipsy moth, the autotomized vesicles are phagocytized and digested by the niche cell. In the milkweed bug the autotomized vesicles accumulate at the niche surface and disintegrate. Autotomy and sprouting of new projections appears to occur continuously. The significance of the GSC-niche interactions, however, remains enigmatic. Our concept on the signaling relationship between stem cell-niche in general and GSC and niche (hub cells and cyst stem cells) in particular has been greatly shaped by Drosophila melanogaster. In comparing the interactions of GSCs with their niche in Drosophila with those in species exhibiting GSC autotomy it is obvious that additional or alternative modes of stem cell-niche communication exist. Thus, essential signaling pathways, including niche-stem cell adhesion (E-cadherin) and the direction of asymmetrical GSC division - as they were found in Drosophila - can hardly be translated into the systems where GSC autotomy was reported. It is shown here that the serial autotomy of GSC projections shows remarkable similarities with Wallerian axonal destruction, developmental axon pruning and dying-back degeneration in neurodegenerative diseases. Especially the hypothesis of an existing evolutionary conserved “autodestruction program” in axons that might also be active in GSC projections appears attractive. Investigations on the underlying signaling pathways have to be carried out. There are two other well known cases of programmed cell autotomy: the enucleation of erythroblasts in the process of erythrocyte maturation and the segregation of thousands of thrombocytes (platelets) from one megakaryocyte. Both progenitor cell types - erythroblasts and megakaryocytes - are associated with a niche in the bone marrow, erythroblasts with a macrophage, which they surround, and the megakaryocytes with the endothelial cells of sinusoids and their extracellular matrix. Although the regulatory mechanisms may be specific in each case, there is one aspect that connects all described processes of programmed cell autotomy and neuronal autodestruction: apoptotic pathways play always a prominent role. Studies on the role of male GSC autotomy in stem cell-niche interaction have just started but are expected to reveal hitherto unknown ways of signal exchange. Spermatogenesis in mammals advance our understanding of insect spermatogenesis. Mammal and insect spermatogenesis share some broad principles, but a comparison of the signaling pathways is difficult. We have intimate knowledge from Drosophila, but of almost no other insect, and we have only limited knowledge from mammals. The discovery of stem cell autotomy as part of the interaction with the niche promises new general insights into the complicated stem cell-niche interdependence.
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Li C, Zheng L. The pharmacology and clinical application of thrombopoietin receptor agonists. Int J Hematol 2014; 100:529-39. [DOI: 10.1007/s12185-014-1660-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 08/14/2014] [Accepted: 08/20/2014] [Indexed: 12/17/2022]
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Sangkhae V, Saur SJ, Kaushansky A, Kaushansky K, Hitchcock IS. Phosphorylated c-Mpl tyrosine 591 regulates thrombopoietin-induced signaling. Exp Hematol 2014; 42:477-86.e4. [PMID: 24607955 DOI: 10.1016/j.exphem.2014.02.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 02/05/2014] [Accepted: 02/21/2014] [Indexed: 01/17/2023]
Abstract
Thrombopoietin (TPO) is the primary regulator of platelet production, affecting cell survival, proliferation, and differentiation through binding to and stimulation of the cell surface receptor the cellular myeloproliferative leukemia virus oncogene (c-Mpl). Activating mutations in c-Mpl constitutively stimulate downstream signaling pathways, leading to aberrant hematopoiesis, and contribute to development of myeloproliferative neoplasms. Several studies have mapped the tyrosine residues within the cytoplasmic domain of c-Mpl that mediate these cellular signals; however, secondary signaling pathways are incompletely understood. In this study, we focused on c-Mpl tyrosine 591 (Y591). We found Y591 of wild-type c-Mpl to be phosphorylated in the presence of TPO. Additionally, eliminating Y591 phosphorylation by mutation to Phe resulted in decreased total receptor phosphorylation. Using a Src homology 2/phosphotyrosine-binding (SH2/PTB) domain binding microarray, we identified novel c-Mpl binding partners for phosphorylated Y591, including Src homology region 2 domain-containing phosphatase-1 (SHP-1), spleen tyrosine kinase (SYK) and Bruton's tyrosine kinase (BTK). The functional significance of binding partners was determined through small interfering RNA treatment of Ba/F3-Mpl cells, confirming that the increase in pERK1/2 resulting from removal of Y591 may be mediated by spleen tyrosine kinase. These findings identify a novel negative regulatory pathway that controls TPO-mediated signaling, advancing our understanding of the mechanisms required for successful maintenance of hematopoietic stem cells and megakaryocyte development.
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Affiliation(s)
- Veena Sangkhae
- Department of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Sebastian Jonas Saur
- Department of Hematology/Oncology, Eberhard Karls University Tübingen, Tübingen, Germany
| | | | | | - Ian Stuart Hitchcock
- Department of Hematology/Oncology, Eberhard Karls University Tübingen, Tübingen, Germany.
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Pathak S, Roth M, Verma A, Steidl U. Eltrombopag for the treatment of thrombocytopenia in patients with malignant and non-malignant hematologic disorders. Expert Opin Drug Metab Toxicol 2013; 9:1667-75. [DOI: 10.1517/17425255.2013.858119] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dietary α-linolenic acid increases the platelet count in ApoE-/- mice by reducing clearance. Blood 2013; 122:1026-33. [PMID: 23801636 DOI: 10.1182/blood-2013-02-484741] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Previously we reported that dietary intake of alpha-linolenic acid (ALA) reduces atherogenesis and inhibits arterial thrombosis. Here, we analyze the substantial increase in platelet count induced by ALA and the mechanisms of reduced platelet clearance. Eight-week-old male apolipoprotein E knockout (ApoE(-/-)) mice were fed a 0.21g% cholesterol diet complemented by either a high- (7.3g%) or low-ALA (0.03g%) content. Platelet counts doubled after 16 weeks of ALA feeding, whereas the bleeding time remained similar. Plasma glycocalicin and glycocalicin index were reduced, while reticulated platelets, thrombopoietin, and bone marrow megakaryocyte colony-forming units remained unchanged. Platelet contents of liver and spleen were substantially reduced, without affecting macrophage function and number. Glycoprotein Ib (GPIb) shedding, exposure of P-selectin, and activated integrin αIIbβ3 upon activation with thrombin were reduced. Dietary ALA increased the platelet count by reducing platelet clearance in the reticulo-endothelial system. The latter appears to be mediated by reduced cleavage of GPIb by tumor necrosis factor-α-converting enzyme and reduced platelet activation/expression of procoagulant signaling. Ex vivo, there was less adhesion of human platelets to von Willebrand factor under high shear conditions after ALA treatment. Thus, ALA may be a promising tool in transfusion medicine and in high turnover/high activation platelet disorders.
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Abstract
Eltrombopag is a 2nd generation thrombopoietin-receptor agonist. It binds with the thrombopoietin-receptors found on the surfaces of the megakaryocytes & increases platelet production. Many recent studies have suggested a potential role for this novel agent in the treatment of thrombocytopenia associated with hepatitis-C infection. Studies have shown that adjunct treatment with Eltrombopag can help avoid dose reductions/withdrawals of pegylated interferon secondary to thrombocytopenia. It may also have a role in priming up platelet levels to help initiate antiviral therapy. Similarly, chronic liver disease patients with thrombocytopenia who need to undergo an invasive procedure may be potential candidates for short two-week courses of eltrombopag in the periprocedural period to help reduce the risk of bleeding. Besides the price (deemed very expensive and probably not cost-effective), there are some legitimate concerns about the safety profile of this novel agent (most importantly, portal vein thrombosis, bone marrow fibrosis and hepatotoxicity). In this article, the potential role of eltrombopag in the context of hepatitis C virus (HCV)-related thrombocytopenia is reviewed. To write this article, a MEDLINE search was conducted (1990 to November 2012) using the search terms “eltrombopag,” “HCV,” and “thrombocytopenia.”
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Matthys G, Park JW, McGuire S, Wire MB, Bowen C, Williams D, Jenkins J, Peng B. Pharmacokinetics and Pharmacodynamics Clinical Pharmacokinetics, Platelet Response, and Safety of Eltrombopag at Supratherapeutic Doses of up to 200 mg Once Daily in Healthy Volunteers. J Clin Pharmacol 2013; 51:301-8. [DOI: 10.1177/0091270010368677] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wu MX, Ustyugova IV, Han L, Akilov OE. Immediate early response gene X-1, a potential prognostic biomarker in cancers. Expert Opin Ther Targets 2013; 17:593-606. [PMID: 23379921 DOI: 10.1517/14728222.2013.768234] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The immediate early response gene X-1 (IEX-1) plays a pivotal role in the regulation of cell apoptosis, proliferation, differentiation and metabolism. Deregulation of IEX-1 expression has been confirmed in multiple cancers in humans, in association with either poor or better prognosis depending on the type and progression stages of the cancer. AREAS COVERED This review summarizes clinical studies of altered IEX-1 expression in ovarian, pancreatic, blood, breast and colorectal cancers, lymphoma and myeloma. The authors also outline the current understandings of the complex functions of IEX-1 gained from studies with animal models and tumor cell lines so as to help us comprehend the significance of the clinical findings. EXPERT OPINION IEX-1 holds great promise to be a valuable biomarker, either alone or in combination with other genes, for monitoring progression of some cancers. IEX-1 expression is highly sensitive to environmental cues and distinct between normal and cancer cells. However, use of IEX-1 as a biomarker remains a significant challenge because too little is understood about the mechanism underlying the diverse activities of IEX-1 and a standardized clinical assay for IEX-1 detection and validation of clinical results across different studies are still critically lacking.
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Affiliation(s)
- Mei X Wu
- Massachusetts General Hospital and Harvard Medical School, Wellman Center for Photomedicine, Department of Dermatology , Edwards 222, 50 Blossom Street, Boston, MA 02114, USA.
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High doses of romiplostim induce proliferation and reduce proplatelet formation by human megakaryocytes. PLoS One 2013; 8:e54723. [PMID: 23359807 PMCID: PMC3554640 DOI: 10.1371/journal.pone.0054723] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 12/17/2012] [Indexed: 12/21/2022] Open
Abstract
Background Romiplostim (AMG531) is a Thrombopoietin (TPO) receptor agonist with no homology with the endogenous TPO that has been used to treat patients affected by immune thrombocytopenia (ITP). Despite the use of TPO mimetics in the clinical practice, the mechanisms underlying their impact on megakaryocyte function is still unknown. Methodology/Principal Findings In this project we took advantage of an in vitro human model, that we have established in our laboratory for long time to study megakaryocyte development from human cord blood-derived progenitor cells, and we demonstrated that increasing doses of AMG531 (100 to 2000 ng/mL) determine a progressive increase of megakaryocyte proliferation with a parallel decrease in megakaryocyte ploidy and capacity of extending proplatelets. Most importantly, these differences in megakaryocyte function seemed to be correlated to modulation of AKT phosphorylation. Conclusions/Significance Overall our results shed new light on the mechanisms and on the relevance of dosage related to AMG531 impact on megakaryocyte function.
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Wilcox DA. Gene Therapy for Platelet Disorders. Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00064-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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40
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Psaila B, Bussel JB. Immune Thrombocytopenia (ITP). Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00040-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Limb JK, Song D, Jeon M, Han SY, Han G, Jhon GJ, Bae YS, Kim J. 2-(trimethylammonium)ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate promotes megakaryocytic differentiation of myeloid leukaemia cells and primary human CD34⁺ haematopoietic stem cells. J Tissue Eng Regen Med 2012; 9:435-46. [PMID: 23166016 DOI: 10.1002/term.1628] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 07/12/2012] [Accepted: 08/30/2012] [Indexed: 12/27/2022]
Abstract
In this study we showed that 2-(trimethylammonium)ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a derivative of an organic chemical identified from a natural product library, promotes highly efficient differentiation of megakaryocytes. Specifically, (R)-TEMOSPho induces cell cycle arrest, cell size increase and polyploidization from K562 and HEL cells, which are used extensively to model megakaryocytic differentiation. In addition, megakaryocyte-specific cell surface markers showed a dramatic increase in expression in response to (R)-TEMOSPho treatment. Importantly, we demonstrated that such megakaryocytic differentiation can also be induced from primary human CD34(+) haematopoietic stem cells. Activation of the PI3K-AKT pathway and, to a lesser extent, the MEK-ERK pathway appears to be required for this process, as blocking with specific inhibitors interferes with the differentiation of K562 cells. A subset of (R)-TEMOSPho-treated K562 cells undergoes spontaneous apoptosis and produces platelets that are apparently functional, as they bind to fibrinogen, express P-selectin and aggregate in response to SFLLRN and AYPGFK, the activating peptides for the PAR1 and PAR4 receptors, respectively. Taken together, these results indicate that (R)-TEMOSPho will be useful for dissecting the molecular mechanisms of megakaryocytic differentiation, and that this class of compounds represents potential therapeutic reagents for thrombocytopenia.
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Affiliation(s)
- Jin-Kyung Limb
- Division of Life and Pharmaceutical Sciences and Centre for Cell Signalling and Drug Discovery Research, Ewha Womans University, Seoul, Republic of Korea; Department of Chemistry and Division of Nano Sciences, Ewha Womans University, Seoul, Republic of Korea
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Eliades A, Matsuura S, Ravid K. Oxidases and reactive oxygen species during hematopoiesis: a focus on megakaryocytes. J Cell Physiol 2012; 227:3355-62. [PMID: 22331622 DOI: 10.1002/jcp.24071] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Reactive oxygen species (ROS), generated as a result of various reactions, control an array of cellular processes. The role of ROS during megakaryocyte (MK) development has been a subject of interest and research. The bone marrow niche is a site of MK differentiation and maturation. In this environment, a gradient of oxygen tension, from normoxia to hypoxia results in different levels of ROS, impacting cellular physiology. This article provides an overview of major sources of ROS, their implication in different signaling pathways, and their effect on cellular physiology, with a focus on megakaryopoiesis. The importance of ROS-generating oxidases in MK biology and pathology, including myelofibrosis, is also described.
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Affiliation(s)
- Alexia Eliades
- Department of Biochemistry, Boston University School of Medicine, Boston, MA, USA
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Tamura S, Nagasawa A, Masuda Y, Tsunematsu T, Hayasaka K, Matsuno K, Shimizu C, Ozaki Y, Moriyama T. BDNF, produced by a TPO-stimulated megakaryocytic cell line, regulates autocrine proliferation. Biochem Biophys Res Commun 2012; 427:542-6. [PMID: 23022197 DOI: 10.1016/j.bbrc.2012.09.093] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/14/2012] [Indexed: 12/30/2022]
Abstract
While human platelets release endogenous brain-derived neurotrophic factor (BDNF) upon activation, a previous report on MEG-01, a megakaryocytic cell line, found no trace of BDNF production, and the pathophysiological function of platelet BDNF has remained elusive. In the present study, we demonstrate that MEG-01 produces BDNF in the presence of TPO and that this serves to potentiate cell proliferation. Our in vitro findings suggest that BDNF regulates MEG-01 proliferation in an autocrine manner, and we suggest that BDNF may be a physiological autocrine regulator of megakaryocyte progenitors.
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Affiliation(s)
- Shogo Tamura
- Graduate School of Health Sciences, Hokkaido University, Sapporo, Japan
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Erickson-Miller CL, Pillarisetti K, Kirchner J, Figueroa DJ, Ottesen L, Martin AM, Liu Y, Kamel YM, Messam C. Low or undetectable TPO receptor expression in malignant tissue and cell lines derived from breast, lung, and ovarian tumors. BMC Cancer 2012; 12:405. [PMID: 22967017 PMCID: PMC3480928 DOI: 10.1186/1471-2407-12-405] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 08/09/2012] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Numerous efficacious chemotherapy regimens may cause thrombocytopenia. Thrombopoietin receptor (TPO-R) agonists, such as eltrombopag, represent a novel approach for the treatment of chemotherapy-induced thrombocytopenia. The TPO-R MPL is expressed on megakaryocytes and megakaryocyte precursors, although little is known about its expression on other tissues. METHODS Breast, lung, and ovarian tumor samples were analyzed for MPL expression by microarray and/or quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and for TPO-R protein expression by immunohistochemistry (IHC). Cell line proliferation assays were used to analyze the in vitro effect of eltrombopag on breast, lung, and ovarian tumor cell proliferation. The lung carcinoma cell lines were also analyzed for TPO-R protein expression by Western blot. RESULTS MPL mRNA was not detectable in 118 breast tumors and was detectable at only very low levels in 48% of 29 lung tumors studied by microarray analysis. By qRT-PCR, low but detectable levels of MPL mRNA were detectable in some normal (14-43%) and malignant (3-17%) breast, lung, and ovarian tissues. A comparison of MPL to EPOR, ERBB2, and IGF1R mRNA demonstrates that MPL mRNA levels were far lower than those of EPOR and ERBB2 mRNA in the same tissues. IHC analysis showed negligible TPO-R protein expression in tumor tissues, confirming mRNA analysis. Culture of breast, lung, and ovarian carcinoma cell lines showed no increase, and in fact, showed a decrease in proliferation following incubation with eltrombopag. Western blot analyses revealed no detectable TPO-R protein expression in the lung carcinoma cell lines. CONCLUSIONS Multiple analyses of breast, lung, and ovarian tumor samples and/or cell lines show no evidence of MPL mRNA or TPO-R protein expression. Eltrombopag does not stimulate growth of breast, lung, or ovarian tumor cell lines at doses likely to exert their actions on megakaryocytes and megakaryocyte precursors.
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Affiliation(s)
| | | | - Jennifer Kirchner
- GlaxoSmithKline, 1250 South Collegeville Rd, Collegeville, PA, 19426, USA
| | - David J Figueroa
- GlaxoSmithKline, 1250 South Collegeville Rd, Collegeville, PA, 19426, USA
| | - Lone Ottesen
- GlaxoSmithKline, Stockley Park, Uxbridge, Middlesex UB11 1BT, UK
| | - Anne-Marie Martin
- GlaxoSmithKline, 1250 South Collegeville Rd, Collegeville, PA, 19426, USA
| | - Yuan Liu
- GlaxoSmithKline, 1250 South Collegeville Rd, Collegeville, PA, 19426, USA
| | | | - Conrad Messam
- GlaxoSmithKline, 1250 South Collegeville Rd, Collegeville, PA, 19426, USA
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Noronha V, Philip SD, Joshi A, Prabhash K. Prolonged remission from eltrombopag in chronic refractory idiopathic thrombocytopenic purpura. Int J Hematol 2012; 96:380-2. [DOI: 10.1007/s12185-012-1154-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 11/28/2022]
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Shen J, Wan R, Hu G, Wang F, Shen J, Wang X. Involvement of thrombopoietin in acinar cell necrosis in L-arginine-induced acute pancreatitis in mice. Cytokine 2012; 60:294-301. [PMID: 22698803 DOI: 10.1016/j.cyto.2012.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/14/2012] [Accepted: 05/08/2012] [Indexed: 12/19/2022]
Abstract
Thrombopoietin (TPO) plays an important role in injuries of different tissues. However, the role of TPO in acute pancreatitis (AP) is not yet known. The aim of the study was to determine the involvement of TPO in AP. Serum TPO was assayed in necrotizing pancreatitis induced by L-arginine in mice. Recombinant TPO and anti-TPO antibody were given to mice with necrotizing pancreatitis. Amylase, lipase, lactate dehydrogenase, myeloperoxidase activity and pancreatic water content were assayed in serum and tissue samples. Pancreas and lung tissue samples were also collected for histological evaluation. Immunohistochemistry of amylase α and PCNA were applied for the study of acinar regeneration and TUNEL assay for the detection of apoptosis in the pancreas. Increased levels of serum TPO were found in necrotizing pancreatitis. After TPO administration, more severe acinar necrosis was found and blockade of TPO reduced the acinar necrosis in this AP model. Acinar regeneration and apoptosis in the pancreas were affected by TPO and antibody treatment in necrotizing pancreatitis. The severity of pancreatitis-associated lung injury was worsened after TPO treatment, but attenuated after Anti-TPO antibody treatment. In conclusion, serum TPO is up-regulated in the necrotizing pancreatitis induced by L-arginine in mice and may be a risk factor for the pancreatic acinar necrosis in AP. As a pro-necrotic factor, blockade of TPO can attenuate the acinar necrosis in AP and may be a possible therapeutic intervention for AP.
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Affiliation(s)
- Jiaqing Shen
- Department of Gastroenterology, The First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Vulcano F, Milazzo L, Ciccarelli C, Barca A, Agostini F, Altieri I, Macioce G, Di Virgilio A, Screnci M, De Felice L, Giampaolo A, Hassan HJ. Valproic acid affects the engraftment of TPO-expanded cord blood cells in NOD/SCID mice. Exp Cell Res 2012; 318:400-7. [DOI: 10.1016/j.yexcr.2011.11.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/07/2011] [Accepted: 11/24/2011] [Indexed: 10/14/2022]
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Ivanovic Z, Vlaski M. Ex Vivo Expansion of Stem and Progenitor Cells Using Thrombopoietin. STEM CELLS AND CANCER STEM CELLS, VOLUME 8 2012. [DOI: 10.1007/978-94-007-4798-2_33] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Knight E, Eichenbaum G, Hillsamer V, Greway T, Tonelli A, Han-Hsu H, Zakszewski C, Yurkow E, Shukla U, End D, Louden C. Nonclinical safety assessment of a synthetic peptide thrombopoietin agonist: effects on platelets, bone homeostasis, and immunogenicity and the implications for clinical safety monitoring of adverse bone effects. Int J Toxicol 2011; 30:385-404. [PMID: 21832269 DOI: 10.1177/1091581811404708] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
RWJ-800088 is a novel, potent polyethylene glycol (PEG)-conjugated thrombopoietin (TPO) mimetic that increases platelet levels and protects against thrombocytopenia. A nonclinical safety program was customized for this peptide that takes into account its protein-like structure, synthetic chemical nature, agonist pharmacologic activity, and mode of administration. In repeat-dose toxicity studies, the salient findings were dose-related increases in circulating platelet counts, mean platelet volume, and megakaryocytes in the bone marrow with no antibody formation. Reversible myelofibrosis and hyperostosis were observed in rats, but not dogs, when the circulating platelet levels exceeded 3× those of vehicle controls. The bone effects were due to the exaggerated pharmacologic effect and excessive stimulation and elevation of megakaryocytes by TPO, which results in intramedullary proliferation of fibroblasts and mesenchymal cells followed by osseous metaplasia. These findings support the use of platelet elevations of >3× as a stopping criterion to prevent potential adverse bone-related effects in humans.
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Affiliation(s)
- Elaine Knight
- Johnson and Johnson Pharmaceutical Research and Development, L.L.C., Raritan, NJ 08869, USA
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Eliades A, Papadantonakis N, Bhupatiraju A, Burridge KA, Johnston-Cox HA, Migliaccio AR, Crispino JD, Lucero HA, Trackman PC, Ravid K. Control of megakaryocyte expansion and bone marrow fibrosis by lysyl oxidase. J Biol Chem 2011; 286:27630-8. [PMID: 21665949 DOI: 10.1074/jbc.m111.243113] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Lysyl oxidase (LOX), a matrix cross-linking protein, is known to be selectively expressed and to enhance a fibrotic phenotype. A recent study of ours showed that LOX oxidizes the PDGF receptor-β (PDGFR-β), leading to amplified downstream signaling. Here, we examined the expression and functions of LOX in megakaryocytes (MKs), the platelet precursors. Cells committed to the MK lineage undergo mitotic proliferation to yield diploid cells, followed by endomitosis and acquisition of polyploidy. Intriguingly, LOX expression is detected in diploid-tetraploid MKs, but scarce in polyploid MKs. PDGFR-BB is an inducer of mitotic proliferation in MKs. LOX inhibition with β-aminopropionitrile reduces PDGFR-BB binding to cells and downstream signaling, as well as its proliferative effect on the MK lineage. Inhibition of LOX activity has no influence on MK polyploidy. We next rationalized that, in a system with an abundance of low ploidy MKs, LOX could be highly expressed and with functional significance. Thus, we resorted to GATA-1(low) mice, where there is an increase in low ploidy MKs, augmented levels of PDGF-BB, and an extensive matrix of fibers. MKs from these mice display high expression of LOX, compared with control mice. Importantly, treatment of GATA-1(low) mice with β-aminopropionitrile significantly improves the bone marrow fibrotic phenotype, and MK number in the spleen. Thus, our in vitro and in vivo data support a novel role for LOX in regulating MK expansion by PDGF-BB and suggest LOX as a new potential therapeutic target for myelofibrosis.
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Affiliation(s)
- Alexia Eliades
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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