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Cilek N, Ugurel E, Goksel E, Yalcin O. Signaling mechanisms in red blood cells: A view through the protein phosphorylation and deformability. J Cell Physiol 2024; 239:e30958. [PMID: 36748950 DOI: 10.1002/jcp.30958] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/07/2023] [Accepted: 01/19/2023] [Indexed: 02/08/2023]
Abstract
Intracellular signaling mechanisms in red blood cells (RBCs) involve various protein kinases and phosphatases and enable rapid adaptive responses to hypoxia, metabolic requirements, oxidative stress, or shear stress by regulating the physiological properties of the cell. Protein phosphorylation is a ubiquitous mechanism for intracellular signal transduction, volume regulation, and cytoskeletal organization in RBCs. Spectrin-based cytoskeleton connects integral membrane proteins, band 3 and glycophorin C to junctional proteins, ankyrin and Protein 4.1. Phosphorylation leads to a conformational change in the protein structure, weakening the interactions between proteins in the cytoskeletal network that confers a more flexible nature for the RBC membrane. The structural organization of the membrane and the cytoskeleton determines RBC deformability that allows cells to change their ability to deform under shear stress to pass through narrow capillaries. The shear stress sensing mechanisms and oxygenation-deoxygenation transitions regulate cell volume and mechanical properties of the membrane through the activation of ion transporters and specific phosphorylation events mediated by signal transduction. In this review, we summarize the roles of Protein kinase C, cAMP-Protein kinase A, cGMP-nitric oxide, RhoGTPase, and MAP/ERK pathways in the modulation of RBC deformability in both healthy and disease states. We emphasize that targeting signaling elements may be a therapeutic strategy for the treatment of hemoglobinopathies or channelopathies. We expect the present review will provide additional insights into RBC responses to shear stress and hypoxia via signaling mechanisms and shed light on the current and novel treatment options for pathophysiological conditions.
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Affiliation(s)
- Neslihan Cilek
- Research Center for Translational Medicine (KUTTAM), Koc University, Istanbul, Turkey
- School of Medicine, Koc University, Istanbul, Turkey
- Graduate School of Health Sciences, Koc University, Istanbul, Turkey
| | - Elif Ugurel
- Research Center for Translational Medicine (KUTTAM), Koc University, Istanbul, Turkey
- School of Medicine, Koc University, Istanbul, Turkey
| | - Evrim Goksel
- Research Center for Translational Medicine (KUTTAM), Koc University, Istanbul, Turkey
- School of Medicine, Koc University, Istanbul, Turkey
- Graduate School of Health Sciences, Koc University, Istanbul, Turkey
| | - Ozlem Yalcin
- Research Center for Translational Medicine (KUTTAM), Koc University, Istanbul, Turkey
- School of Medicine, Koc University, Istanbul, Turkey
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2
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Santos JC, Profitós-Pelejà N, Sánchez-Vinces S, Roué G. RHOA Therapeutic Targeting in Hematological Cancers. Cells 2023; 12:cells12030433. [PMID: 36766776 PMCID: PMC9914237 DOI: 10.3390/cells12030433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/19/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Primarily identified as an important regulator of cytoskeletal dynamics, the small GTPase Ras homolog gene family member A (RHOA) has been implicated in the transduction of signals regulating a broad range of cellular functions such as cell survival, migration, adhesion and proliferation. Deregulated activity of RHOA has been linked to the growth, progression and metastasis of various cancer types. Recent cancer genome-wide sequencing studies have unveiled both RHOA gain and loss-of-function mutations in primary leukemia/lymphoma, suggesting that this GTPase may exert tumor-promoting or tumor-suppressive functions depending on the cellular context. Based on these observations, RHOA signaling represents an attractive therapeutic target for the development of selective anticancer strategies. In this review, we will summarize the molecular mechanisms underlying RHOA GTPase functions in immune regulation and in the development of hematological neoplasms and will discuss the current strategies aimed at modulating RHOA functions in these diseases.
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Affiliation(s)
- Juliana Carvalho Santos
- Lymphoma Translational Group, Josep Carreras Leukaemia Research Institute (IJC), 08916 Badalona, Spain
| | - Núria Profitós-Pelejà
- Lymphoma Translational Group, Josep Carreras Leukaemia Research Institute (IJC), 08916 Badalona, Spain
| | - Salvador Sánchez-Vinces
- Laboratory of Immunopharmacology and Molecular Biology, Sao Francisco University Medical School, Braganca Paulista 01246-100, São Paulo, Brazil
| | - Gaël Roué
- Lymphoma Translational Group, Josep Carreras Leukaemia Research Institute (IJC), 08916 Badalona, Spain
- Correspondence: ; Tel.: +34-935572835
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3
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Tu Z, Fan C, Davis AK, Hu M, Wang C, Dandamudi A, Seu KG, Kalfa TA, Lu QR, Zheng Y. Autism-associated chromatin remodeler CHD8 regulates erythroblast cytokinesis and fine-tunes the balance of Rho GTPase signaling. Cell Rep 2022; 40:111072. [PMID: 35830790 PMCID: PMC9302451 DOI: 10.1016/j.celrep.2022.111072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 05/09/2022] [Accepted: 06/16/2022] [Indexed: 11/15/2022] Open
Abstract
CHD8 is an ATP-dependent chromatin-remodeling factor whose monoallelic mutation defines a subtype of autism spectrum disorders (ASDs). Previous work found that CHD8 is required for the maintenance of hematopoiesis by integrating ATM-P53-mediated survival of hematopoietic stem/progenitor cells (HSPCs). Here, by using Chd8F/FMx1-Cre combined with a Trp53F/F mouse model that suppresses apoptosis of Chd8−/− HSPCs, we identify CHD8 as an essential regulator of erythroid differentiation. Chd8−/−P53−/− mice exhibited severe anemia conforming to congenital dyserythropoietic anemia (CDA) phenotypes. Loss of CHD8 leads to drastically decreased numbers of orthochromatic erythroblasts and increased binucleated and multinucleated basophilic erythroblasts with a cytokinesis failure in erythroblasts. CHD8 binds directly to the gene bodies of multiple Rho GTPase signaling genes in erythroblasts, and loss of CHD8 results in their dysregulated expression, leading to decreased RhoA and increased Rac1 and Cdc42 activities. Our study shows that autism-associated CHD8 is essential for erythroblast cytokinesis. Tu et al. report that CHD8, an autism-related chromatin remodeler, is essential for erythroid differentiation. Loss of CHD8 leads to unbalanced Rho GTPase signaling and defective erythroblast cytokinesis, mimicking that of congenital dyserythropoietic anemia.
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Affiliation(s)
- Zhaowei Tu
- Department of Obstetrics and Gynecology, Guangdong Provincial Key Laboratory for Major Obstetric Diseases, Guangdong Engineering and Technology Research Center of Maternal-Fetal Medicine, Guangdong-Hong Kong-Macao Greater Bay Area Higher Education Joint Laboratory of Maternal-Fetal Medicine, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, China; Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Cuiqing Fan
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Ashely K Davis
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Mengwen Hu
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, USA
| | - Chen Wang
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Akhila Dandamudi
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Katie G Seu
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Theodosia A Kalfa
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Q Richard Lu
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Yi Zheng
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229, USA.
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4
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Ramos DFV, Mancuso RI, Contieri B, Duarte A, Paiva L, de Melo Carrilho J, Saad STO, Lazarini M. Rac GTPases in acute myeloid leukemia cells: Expression profile and biological effects of pharmacological inhibition. Toxicol Appl Pharmacol 2022; 442:115990. [PMID: 35331739 DOI: 10.1016/j.taap.2022.115990] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 03/10/2022] [Accepted: 03/17/2022] [Indexed: 12/17/2022]
Abstract
Acute myeloid leukemia (AML) is a highly heterogeneous hematological neoplasm with low survival rates. Thus, the investigation of new therapeutic targets is essential. The Rac subfamily of GTPase proteins has been shown to participate in the physiopathology of hematological malignancies. However, their expression and function in AML remain unclear. In this study, we evaluated Rac1, Rac2 and Rac3 gene expressions in AML and their impact on clinical outcomes. We further investigated the effects of the in vitro treatment with a Rac inhibitor (EHT-1864) on AML cell lines. Rac3 expression was increased in AML derived from myelodysplastic syndromes compared to healthy donors. Rac2 expression did not differ between AML patients and healthy donors, but de novo AML patients with higher Rac2 presented lower overall survival. Oncogenic pathway gene-sets related to AKT/mTOR were identified as associated with Rac1, Rac2 and Rac3 expressions. EHT-1864 treatment reduced the viability of OCI-AML3, KG1 and Kasumi-1 cells in a time and dose-dependent manner. In OCI-AML3 cells, treatment with EHT-1864 induced apoptosis, autophagy, and led to the accumulation of cells in the G1 phase of the cell cycle. These changes were concomitant with alterations in p53 and cyclins. Dowregulation of the PI3K/AKT/mTOR pathway was also observed. Interestingly, the combined treatment of EHT-1864 and low doses of daunorubicin enhanced OCI-AML3 cell apoptosis. In conclusion, Rac2 expression is a prognostic factor in AML and our preclinical results suggest that Rac inhibition may be an attractive mechanism to compose the antineoplastic strategy for this disease.
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Affiliation(s)
| | - Rubia Isler Mancuso
- Hematology and Bloood Transfusion Center, University of Campinas, Campinas, São Paulo, Brazil
| | - Bruna Contieri
- Department of Pharmaceutical Sciences, Federal University of São Paulo, Diadema, São Paulo, Brazil
| | - Adriana Duarte
- Hematology and Bloood Transfusion Center, University of Campinas, Campinas, São Paulo, Brazil
| | - Luciana Paiva
- Hematology and Bloood Transfusion Center, University of Campinas, Campinas, São Paulo, Brazil
| | | | | | - Mariana Lazarini
- Department of Pharmaceutical Sciences, Federal University of São Paulo, Diadema, São Paulo, Brazil; Hematology and Bloood Transfusion Center, University of Campinas, Campinas, São Paulo, Brazil.
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5
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Lu Z, Huang L, Li Y, Xu Y, Zhang R, Zhou Q, Sun Q, Lu Y, Chen J, Shen Y, Li J, Zhao B. Fine-Tuning of Cholesterol Homeostasis Controls Erythroid Differentiation. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2102669. [PMID: 34739188 PMCID: PMC8805577 DOI: 10.1002/advs.202102669] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/01/2021] [Indexed: 05/12/2023]
Abstract
Lipid metabolism is essential for stemness maintenance, self-renewal, and differentiation of stem cells, however, the regulatory function of cholesterol metabolism in erythroid differentiation is poorly studied. In the present study, a critical role for cholesterol homeostasis in terminal erythropoiesis is uncovered. The master transcriptional factor GATA1 binds to Sterol-regulatory element binding protein 2 (SREBP2) to downregulate cholesterol biosynthesis, leading to a gradual reduction in intracellular cholesterol levels. It is further shown that reduced cholesterol functions to block erythroid proliferation via the cholesterol/mTORC1/ribosome biogenesis axis, which coordinates cell cycle exit in the late stages of erythroid differentiation. The interaction of GATA1 and SREBP2 also provides a feedback loop for regulating globin expression through the transcriptional control of NFE2 by SREBP2. Importantly, it is shown that disrupting intracellular cholesterol hemostasis resulted in defect of terminal erythroid differentiation in vivo. These findings demonstrate that fine-tuning of cholesterol homeostasis emerges as a key mechanism for regulating erythropoiesis.
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Affiliation(s)
- Zhiyuan Lu
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Lixia Huang
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Yanxia Li
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Yan Xu
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Ruihao Zhang
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Qian Zhou
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Qi Sun
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Yi Lu
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Junjie Chen
- Analysis and Measurement CenterSchool of Pharmaceutical SciencesXiamen UniversityXiamenFujian361001China
| | - Yuemao Shen
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Jian Li
- Department of Biochemistry and Molecular BiologySchool of Basic Medical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
| | - Baobing Zhao
- Key Laboratory of Chemical Biology (Ministry of Education)School of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
- Department of PharmacologySchool of Pharmaceutical SciencesCheeloo College of MedicineShandong UniversityJinanShandong250012China
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6
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A new role of glutathione peroxidase 4 during human erythroblast enucleation. Blood Adv 2021; 4:5666-5680. [PMID: 33211827 DOI: 10.1182/bloodadvances.2020003100] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
The selenoprotein glutathione peroxidase 4 (GPX4), the only member of the glutathione peroxidase family able to directly reduce cell membrane-oxidized fatty acids and cholesterol, was recently identified as the central regulator of ferroptosis. GPX4 knockdown in mouse hematopoietic cells leads to hemolytic anemia and to increased spleen erythroid progenitor death. The role of GPX4 during human erythropoiesis is unknown. Using in vitro erythroid differentiation, we show here that GPX4-irreversible inhibition by 1S,3R-RSL3 (RSL3) and its short hairpin RNA-mediated knockdown strongly impaired enucleation in a ferroptosis-independent manner not restored by tocopherol or iron chelators. During enucleation, GPX4 localized with lipid rafts at the cleavage furrows between reticulocytes and pyrenocytes. Its inhibition impacted enucleation after nuclear condensation and polarization and was associated with a defect in lipid raft clustering (cholera toxin staining) and myosin-regulatory light-chain phosphorylation. Because selenoprotein translation and cholesterol synthesis share a common precursor, we investigated whether the enucleation defect could represent a compensatory mechanism favoring GPX4 synthesis at the expense of cholesterol, known to be abundant in lipid rafts. Lipidomics and filipin staining failed to show any quantitative difference in cholesterol content after RSL3 exposure. However, addition of cholesterol increased cholera toxin staining and myosin-regulatory light-chain phosphorylation, and improved enucleation despite GPX4 knockdown. In summary, we identified GPX4 as a new actor of human erythroid enucleation, independent of its function in ferroptosis control. We described its involvement in lipid raft organization required for contractile ring assembly and cytokinesis, leading in fine to nucleus extrusion.
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7
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Gene Expression Analysis of Mevalonate Kinase Deficiency Affected Children Identifies Molecular Signatures Related to Hematopoiesis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18031170. [PMID: 33525735 PMCID: PMC7908123 DOI: 10.3390/ijerph18031170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/21/2021] [Accepted: 01/23/2021] [Indexed: 12/12/2022]
Abstract
Mevalonate kinase deficiency (MKD) is a rare autoinflammatory genetic disorder characterized by recurrent fever attacks and systemic inflammation with potentially severe complications. Although it is recognized that the lack of protein prenylation consequent to mevalonate pathway blockade drives IL1β hypersecretion, and hence autoinflammation, MKD pathogenesis and the molecular mechanisms underlaying most of its clinical manifestations are still largely unknown. In this study, we performed a comprehensive bioinformatic analysis of a microarray dataset of MKD patients, using gene ontology and Ingenuity Pathway Analysis (IPA) tools, in order to identify the most significant differentially expressed genes and infer their predicted relationships into biological processes, pathways, and networks. We found that hematopoiesis linked biological functions and pathways are predominant in the gene ontology of differentially expressed genes in MKD, in line with the observed clinical feature of anemia. We also provided novel information about the molecular mechanisms at the basis of the hematological abnormalities observed, that are linked to the chronic inflammation and to defective prenylation. Considering the broad and unspecific spectrum of MKD clinical manifestations and the difficulty in its diagnosis, a better understanding of MKD molecular bases could be translated to the clinical level to facilitate diagnosis, and improve management and therapy.
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8
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Paone S, D'Alessandro S, Parapini S, Celani F, Tirelli V, Pourshaban M, Olivieri A. Characterization of the erythrocyte GTPase Rac1 in relation to Plasmodium falciparum invasion. Sci Rep 2020; 10:22054. [PMID: 33328606 PMCID: PMC7744522 DOI: 10.1038/s41598-020-79052-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 11/30/2020] [Indexed: 12/01/2022] Open
Abstract
Malaria is still a devastating disease with 228 million cases globally and 405,000 lethal outcomes in 2018, mainly in children under five years of age. The threat of emerging malaria strains resistant to currently available drugs has made the search for novel drug targets compelling. The process by which Plasmodium falciparum parasites invade the host cell has been widely studied, but only a few erythrocyte proteins involved in this process have been identified so far. The erythrocyte protein Rac1 is a GTPase that plays an important role in host cell invasion by many intracellular pathogens. Here we show that Rac1 is recruited in proximity to the site of parasite entry during P. falciparum invasion process and that subsequently localizes to the parasitophorous vacuole membrane. We also suggest that this GTPase may be involved in erythrocyte invasion by P. falciparum, by testing the effect of specific Rac1 inhibitory compounds. Finally, we suggest a secondary role of the erythrocyte GTPase also in parasite intracellular development. We here characterize a new erythrocyte protein potentially involved in P. falciparum invasion of the host cell and propose the human GTPase Rac1 as a novel and promising antimalarial drug target.
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Affiliation(s)
- Silvio Paone
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy.,Dipartimento di Sanità Pubblica e Malattie Infettive, Sapienza University of Rome, Rome, Italy
| | - Sarah D'Alessandro
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, University of Milan, Milan, Italy
| | - Silvia Parapini
- Dipartimento di Scienze Biomediche Per La Salute, University of Milan, Milan, Italy
| | - Francesco Celani
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Valentina Tirelli
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | | | - Anna Olivieri
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy.
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9
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Han SY, Lee EM, Kim S, Kwon AM, Baek EJ. Role of Plasma Gelsolin Protein in the Final Stage of Erythropoiesis and in Correction of Erythroid Dysplasia In Vitro. Int J Mol Sci 2020; 21:ijms21197132. [PMID: 32992584 PMCID: PMC7583768 DOI: 10.3390/ijms21197132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 11/16/2022] Open
Abstract
Gelsolin, an actin-remodeling protein, is involved in cell motility, cytoskeletal remodeling, and cytokinesis and is abnormally expressed in many cancers. Recently, human recombinant plasma gelsolin protein (pGSN) was reported to have important roles in cell cycle and maturation of primary erythroblasts. However, the role of human plasma gelsolin in late stage erythroblasts prior to enucleation and putative clinical relevance in patients with myelodysplastic syndrome (MDS) and hemato-oncologic diseases have not been reported. Polychromatic and orthochromatic erythroblasts differentiated from human cord blood CD34+ cells, and human bone marrow (BM) cells derived from patients with MDS, were cultured in serum-free medium containing pGSN. Effects of pGSN on mitochondria, erythroid dysplasia, and enucleation were assessed in cellular and transcriptional levels. With pGSN treatment, terminal maturation at the stage of poly- and ortho-chromatic erythroblasts was enhanced, with higher numbers of orthochromatic erythroblasts and enucleated red blood cells (RBCs). pGSN also significantly decreased dysplastic features of cell morphology. Moreover, we found that patients with MDS with multi-lineage dysplasia or with excess blasts-1 showed significantly decreased expression of gelsolin mRNA (GSN) in their peripheral blood. When BM erythroblasts of MDS patients were cultured with pGSN, levels of mRNA transcripts related to terminal erythropoiesis and enucleation were markedly increased, with significantly decreased erythroid dysplasia. Moreover, pGSN treatment enhanced mitochondrial transmembrane potential that is unregulated in MDS and cultured cells. Our findings demonstrate a key role for plasma gelsolin in erythropoiesis and in gelsolin-depleted MDS patients, and raises the possibility that pGSN administration may promote erythropoiesis in erythroid dysplasia.
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Affiliation(s)
- So Yeon Han
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul 04763, Korea; (S.Y.H.); (S.K.)
- Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea;
| | - Eun Mi Lee
- Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea;
| | - Suyeon Kim
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul 04763, Korea; (S.Y.H.); (S.K.)
| | - Amy M. Kwon
- Biostatistical Consulting and Research Laboratory, Medical Research Collaborating Center, Industry-University Cooperation Foundation, Hanyang University, Seoul 04763, Korea;
| | - Eun Jung Baek
- Department of Laboratory Medicine, College of Medicine, Hanyang University, Seoul 04763, Korea; (S.Y.H.); (S.K.)
- Department of Translational Medicine, Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea;
- Correspondence: ; Tel.: +82-31-560-2485; Fax: +82-31-560-2489
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10
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Nguyen H, Ung A, Ward WS. The role of ORC4 in enucleation of Murine Erythroleukemia (MEL) cells is similar to that in oocyte polar body extrusion. Syst Biol Reprod Med 2020; 66:378-386. [PMID: 32972244 DOI: 10.1080/19396368.2020.1822458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The Origin Replication Complex subunit 4 (ORC4) is one in six subunits of the Origin Replication Complexes (ORCs) which is essential for initiating licensing at DNA replication origins and recruiting adaptor molecules necessary for various cellular processes. Previously, we reported that ORC4 also plays a vital role in polar body extrusion (PBE) during oogenesis in which half the chromosomes are extruded from the oocyte. We hypothesized that ORC4 might play a broader role in chromatin elimination. We tested its role in enucleation during the development of erythrocytes. Murine erythroleukemia (MEL) cells can be propagated in culture indefinitely and can be induced to enucleate their DNA by treatment with Vacuolin-1, thereby mimicking normal erythrocyte enucleation. We found that ORC4 appeared around the nuclei of the MEL cells with Vacuolin-1 treatment, gradually increasing in thickness before enucleation. We then tested whether ORC4 was required for MEL enucleation by down regulating ORC4 with siRNA-ORC4 during Vacuolin-1 treatment and found that this prevented MEL enucleation. These data are consistent with the model that ORC4 is required for erythroblast enucleation just as it is for oocyte PBE. They suggest a new model in which ORC4 expression is a marker for the initiation to the enucleation pathway.
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Affiliation(s)
- Hieu Nguyen
- Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 1960 East-West Rd., University of Hawaii , Honolulu, HI, USA 96822
| | - Anna Ung
- Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 1960 East-West Rd., University of Hawaii , Honolulu, HI, USA 96822
| | - W Steven Ward
- Department of Anatomy, Biochemistry, and Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 1960 East-West Rd., University of Hawaii , Honolulu, HI, USA 96822
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11
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Endothelial Cell-Selective Adhesion Molecule Contributes to the Development of Definitive Hematopoiesis in the Fetal Liver. Stem Cell Reports 2020; 13:992-1005. [PMID: 31813828 PMCID: PMC6915804 DOI: 10.1016/j.stemcr.2019.11.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 11/04/2019] [Accepted: 11/06/2019] [Indexed: 02/06/2023] Open
Abstract
Endothelial cell-selective adhesion molecule (ESAM) is a lifelong marker of hematopoietic stem cells (HSCs). Although we previously elucidated the functional importance of ESAM in HSCs in stress-induced hematopoiesis in adults, it is unclear how ESAM affects hematopoietic development during fetal life. To address this issue, we analyzed fetuses from conventional or conditional ESAM-knockout mice. Approximately half of ESAM-null fetuses died after mid-gestation due to anemia. RNA sequencing analyses revealed downregulation of adult-type globins and Alas2, a heme biosynthesis enzyme, in ESAM-null fetal livers. These abnormalities were attributed to malfunction of ESAM-null HSCs, which was demonstrated in culture and transplantation experiments. Although crosslinking ESAM directly influenced gene transcription in HSCs, observations in conditional ESAM-knockout fetuses revealed the critical involvement of ESAM expressed in endothelial cells in fetal lethality. Thus, we showed that ESAM had important roles in developing definitive hematopoiesis. Furthermore, we unveiled the importance of endothelial ESAM in this process.
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12
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Nigra AD, Casale CH, Santander VS. Human erythrocytes: cytoskeleton and its origin. Cell Mol Life Sci 2020; 77:1681-1694. [PMID: 31654099 PMCID: PMC11105037 DOI: 10.1007/s00018-019-03346-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 09/27/2019] [Accepted: 10/16/2019] [Indexed: 01/02/2023]
Abstract
In the last few years, erythrocytes have emerged as the main determinant of blood rheology. In mammals, these cells are devoid of nuclei and are, therefore, unable to divide. Consequently, all circulating erythrocytes come from erythropoiesis, a process in the bone marrow in which several modifications are induced in the expression of membrane and cytoskeletal proteins, and different vertical and horizontal interactions are established between them. Cytoskeleton components play an important role in this process, which explains why they and the interaction between them have been the focus of much recent research. Moreover, in mature erythrocytes, the cytoskeleton integrity is also essential, because the cytoskeleton confers remarkable deformability and stability on the erythrocytes, thus enabling them to undergo deformation in microcirculation. Defects in the cytoskeleton produce changes in erythrocyte deformability and stability, affecting cell viability and rheological properties. Such abnormalities are seen in different pathologies of special interest, such as different types of anemia, hypertension, and diabetes, among others. This review highlights the main findings in mammalian erythrocytes and their progenitors regarding the presence, conformation and function of the three main components of the cytoskeleton: actin, intermediate filaments, and tubulin.
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Affiliation(s)
- Ayelén D Nigra
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800, Río Cuarto, Córdoba, Argentina
- Departamento de Química Biológica, Facultad de Ciencias Químicas, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), UNC-CONICET, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina
| | - Cesar H Casale
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800, Río Cuarto, Córdoba, Argentina
| | - Verónica S Santander
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, 5800, Río Cuarto, Córdoba, Argentina.
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Xie S, Yan B, Feng J, Wu Y, He N, Sun L, Zhou J, Li D, Liu M. Altering microtubule stability affects microtubule clearance and nuclear extrusion during erythropoiesis. J Cell Physiol 2019; 234:19833-19841. [PMID: 31344990 DOI: 10.1002/jcp.28582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 03/06/2019] [Accepted: 03/14/2019] [Indexed: 12/11/2022]
Abstract
Mammalian erythrocytes are highly specialized cells that have adapted to lose their nuclei and cellular components during maturation to ensure oxygen delivery. Nuclear extrusion, the most critical event during erythropoiesis, represents an extreme case of asymmetric partitioning that requires a dramatic reorganization of the cytoskeleton. However, the precise role of the microtubule cytoskeleton in the enucleation process remains controversial. In this study, we show that microtubule reorganization is critical for microtubule clearance and nuclear extrusion during erythropoiesis. Using a rodent anemia model, we found that microtubules were present in erythroblasts and reticulocytes but were undetectable in erythrocytes. Further analysis demonstrated that microtubules became disordered in reticulocytes and revealed that microtubule stabilization was critical for tubulin degradation. Disruption of microtubule dynamics using the microtubule-stabilizing agent paclitaxel or the microtubule-destabilizing agent nocodazole did not affect the efficiency of erythroblast enucleation. However, paclitaxel treatment resulted in the retention of tubulin in mature erythrocytes, and nocodazole treatment led to a defect in pyrenocyte morphology. Taken together, our data reveals a critical role for microtubules in erythrocyte development. Our findings also implicate the disruption of microtubule dynamics in the pathogenesis of anemia-associated diseases, providing new insight into the pathogenesis of the microtubule-targeted agent-associated anemia frequently observed during cancer chemotherapy.
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Affiliation(s)
- Songbo Xie
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Bing Yan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Jie Feng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Yuhan Wu
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Na He
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
| | - Lei Sun
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Jun Zhou
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China.,State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Dengwen Li
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China
| | - Min Liu
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong, China
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Zivot A, Lipton JM, Narla A, Blanc L. Erythropoiesis: insights into pathophysiology and treatments in 2017. Mol Med 2018; 24:11. [PMID: 30134792 PMCID: PMC6016880 DOI: 10.1186/s10020-018-0011-z] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 03/02/2018] [Indexed: 12/20/2022] Open
Abstract
Erythropoiesis is a tightly-regulated and complex process originating in the bone marrow from a multipotent stem cell and terminating in a mature, enucleated erythrocyte.Altered red cell production can result from the direct impairment of medullary erythropoiesis, as seen in the thalassemia syndromes, inherited bone marrow failure as well as in the anemia of chronic disease. Alternatively, in disorders such as sickle cell disease (SCD) as well as enzymopathies and membrane defects, medullary erythropoiesis is not, or only minimally, directly impaired. Despite these differences in pathophysiology, therapies have traditionally been non-specific, limited to symptomatic control of anemia via packed red blood cell (pRBC) transfusion, resulting in iron overload and the eventual need for iron chelation or splenectomy to reduce defective red cell destruction. Likewise, in polycythemia vera overproduction of red cells has historically been dealt with by non-specific myelosuppression or phlebotomy. With a deeper understanding of the molecular mechanisms underlying disease pathophysiology, new therapeutic targets have been identified including induction of fetal hemoglobin, interference with aberrant signaling pathways and gene therapy for definitive cure. This review, utilizing some representative disorders of erythropoiesis, will highlight novel therapeutic modalities currently in development for treatment of red cell disorders.
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Affiliation(s)
- Andrea Zivot
- Laboratory of Developmental Erythropoiesis, Center for Autoimmune, Musculoskeletal, and Hematopoietic Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
- Division of Pediatrics Hematology/Oncology and Stem Cell Transplantation, Cohen Children's Medical Center, New Hyde Park, NY, 11040, USA
| | - Jeffrey M Lipton
- Laboratory of Developmental Erythropoiesis, Center for Autoimmune, Musculoskeletal, and Hematopoietic Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA
- Division of Pediatrics Hematology/Oncology and Stem Cell Transplantation, Cohen Children's Medical Center, New Hyde Park, NY, 11040, USA
- Stanford University School of Medicine, Stanford, CA, USA
| | - Anupama Narla
- Department of Molecular Medicine and Pediatrics, Donald and Barbara Zucker School of Medicine at Hofstra Northwell, Hempstead, NY, 11549, USA
| | - Lionel Blanc
- Laboratory of Developmental Erythropoiesis, Center for Autoimmune, Musculoskeletal, and Hematopoietic Diseases, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY, 11030, USA.
- Division of Pediatrics Hematology/Oncology and Stem Cell Transplantation, Cohen Children's Medical Center, New Hyde Park, NY, 11040, USA.
- Stanford University School of Medicine, Stanford, CA, USA.
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15
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申 琪. The Distribution Patterns of Main Ecological Groups of Insects in the World and Its Ecological Significance—Biogeographical Regionalization Research XII. INTERNATIONAL JOURNAL OF ECOLOGY 2018. [DOI: 10.12677/ije.2018.73019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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申 效. The Macroscopic Characteristics of Distribution of Global Terrestrial Biota—Biogeographical Regionalization Research III. INTERNATIONAL JOURNAL OF ECOLOGY 2018. [DOI: 10.12677/ije.2018.72014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Abstract
PURPOSE OF REVIEW Transcriptional regulators provide the molecular and biochemical basis for the cell specific properties and characteristics that follow from their central role in establishing tissue-restricted expression. Precise and sequential control of terminal cell divisions, nuclear condensation, and enucleation are defining characteristics within erythropoietic differentiation. This review is focused on KLF1, a central global regulator of this process. RECENT FINDINGS Studies in the past year have brought a number of proteins that are targets of KLF1 regulation into focus with respect to their roles in terminal erythroid differentiation. Many of these are involved in fine control of the cell cycle at both early (E2F2, Cyclin A2) and later (p18, p27, p19) stages of differentiation, or are directly involved in enucleation (p18, p27). Dramatic biophysical changes controlled at the nuclear lamin by caspase 3 enable histone release and nuclear condensation, whereas dematin association with structural proteins alters the timing of enucleation. Conditional ablation of mDia2 has established its role in late stage cell cycle and enucleation. SUMMARY Transcription factors such as KLF1, along with epigenetic modifiers, play crucial roles in establishing the proper onset and progression of terminal differentiation events. Studies from the past year show a remarkable multifaceted convergence on cell cycle control, and establish that the orthochromatic erythroblast stage is a critical nodal point for many of the effects on enucleation. These studies are relevant to understanding the underlying causes of anemia and hematologic disease where defective enucleation predicts a poor clinical outcome.
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Rivkin N, Chapnik E, Birger Y, Yanowski E, Curato C, Mildner A, Porat Z, Amir G, Izraeli S, Jung S, Hornstein E. Rac1 functions downstream of miR-142 in regulation of erythropoiesis. Haematologica 2017; 102:e476-e480. [PMID: 28912177 DOI: 10.3324/haematol.2017.171736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Natalia Rivkin
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot
| | - Elik Chapnik
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot
| | - Yehudit Birger
- Functional Genomics and Leukemic Research, Cancer Research Center, Sheba Medical Center, Ramat Gan
| | - Eran Yanowski
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot
| | - Caterina Curato
- Department of Immunology Weizmann Institute of Science, Rehovot
| | | | - Ziv Porat
- Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot
| | - Gail Amir
- Department of Pathology, Hadassah Medical Center, Jerusalem
| | - Shai Izraeli
- Functional Genomics and Leukemic Research, Cancer Research Center, Sheba Medical Center, Ramat Gan.,Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Israel
| | - Steffen Jung
- Department of Immunology Weizmann Institute of Science, Rehovot
| | - Eran Hornstein
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot
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Nigra AD, Santander VS, Dircio-Maldonado R, Amaiden MR, Monesterolo NE, Flores-Guzmán P, Muhlberger T, Rivelli JF, Campetelli AN, Mayani H, Casale CH. Tubulin is retained throughout the human hematopoietic/erythroid cell differentiation process and plays a structural role in sedimentable fraction of mature erythrocytes. Int J Biochem Cell Biol 2017; 91:29-36. [PMID: 28855121 DOI: 10.1016/j.biocel.2017.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 07/14/2017] [Accepted: 08/23/2017] [Indexed: 12/24/2022]
Abstract
We investigated the properties of tubulin present in the sedimentable fraction ("Sed-tub") of human erythrocytes, and tracked the location and organization of tubulin in various types of cells during the process of hematopoietic/erythroid differentiation. Sed-tub was sensitive to taxol/nocodazole (drugs that modify microtubule assembly/disassembly), but was organized as part of a protein network rather than in typical microtubule form. This network had a non-uniform "connected-ring" structure, with tubulin localized in the connection areas and associated with other proteins. When tubulin was eliminated from Sed-tub fraction, this connected-ring structure disappeared. Spectrin, a major protein component in Sed-tub fraction, formed a complex with tubulin. During hematopoietic differentiation, tubulin shifts from typical microtubule structure (in pro-erythroblasts) to a disorganized structure (in later stages), and is retained in reticulocytes following enucleation. Thus, tubulin is not completely lost when erythrocytes mature; it continues to play a structural role in the Sed-tub fraction.
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Affiliation(s)
- Ayelén D Nigra
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Verónica S Santander
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Roberto Dircio-Maldonado
- Hematopoietic Stem Cells Laboratory, Oncology Research Unit, IMSS National Medical Center, Mexico City, Mexico
| | - Marina Rafaela Amaiden
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Noelia E Monesterolo
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Patricia Flores-Guzmán
- Hematopoietic Stem Cells Laboratory, Oncology Research Unit, IMSS National Medical Center, Mexico City, Mexico
| | - Tamara Muhlberger
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Juan F Rivelli
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Alexis N Campetelli
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina
| | - Héctor Mayani
- Hematopoietic Stem Cells Laboratory, Oncology Research Unit, IMSS National Medical Center, Mexico City, Mexico
| | - Cesar H Casale
- Departamento de Biología Molecular, Facultad de Ciencias Exactas Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba 5800, Argentina.
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Tropomodulin 1 controls erythroblast enucleation via regulation of F-actin in the enucleosome. Blood 2017; 130:1144-1155. [PMID: 28729432 DOI: 10.1182/blood-2017-05-787051] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/03/2017] [Indexed: 01/01/2023] Open
Abstract
Biogenesis of mammalian red blood cells requires nuclear expulsion by orthochromatic erythoblasts late in terminal differentiation (enucleation), but the mechanism is largely unexplained. Here, we employed high-resolution confocal microscopy to analyze nuclear morphology and F-actin rearrangements during the initiation, progression, and completion of mouse and human erythroblast enucleation in vivo. Mouse erythroblast nuclei acquire a dumbbell-shaped morphology during enucleation, whereas human bone marrow erythroblast nuclei unexpectedly retain their spherical morphology. These morphological differences are linked to differential expression of Lamin isoforms, with primary mouse erythroblasts expressing only Lamin B and primary human erythroblasts only Lamin A/C. We did not consistently identify a continuous F-actin ring at the cell surface constriction in mouse erythroblasts, nor at the membrane protein-sorting boundary in human erythroblasts, which do not have a constriction, arguing against a contractile ring-based nuclear expulsion mechanism. However, both mouse and human erythroblasts contain an F-actin structure at the rear of the translocating nucleus, enriched in tropomodulin 1 (Tmod1) and nonmuscle myosin IIB. We investigated Tmod1 function in mouse and human erythroblasts both in vivo and in vitro and found that absence of Tmod1 leads to enucleation defects in mouse fetal liver erythroblasts, and in CD34+ hematopoietic stem and progenitor cells, with increased F-actin in the structure at the rear of the nucleus. This novel structure, the "enucleosome," may mediate common cytoskeletal mechanisms underlying erythroblast enucleation, notwithstanding the morphological heterogeneity of enucleation across species.
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Abstract
Erythropoiesis is tightly regulated by the growth factor erythropoietin (Epo). Signal activation begins when Epo engages its cognate receptor, Epo-R, triggering receptor homodimerization, and recruitment of signaling intermediates including Jak2 that phosphorylates both the receptor cytoplasmic tail and downstream effectors including the transcription factor, STAT5. Transcription factors subsequently activate transcription of prosurvival and prodifferentiation genes responsible for red blood cell production. The fidelity of Epo-R signaling is dependent upon residence within detergent insoluble membrane lipid raft fractions. Lipid rafts are membrane microdomains that serve as signaling scaffolds composed of densely packed sphingolipids and cholesterol where receptors and intermediate signaling proteins are recruited and interact to execute stimuli. Disruption of lipid rafts is detrimental to Epo signaling, a phenomenon that may be utilized to design novel therapeutics for conditions in which Epo signaling is deficient. Here, we review the Epo signaling cascade, particularly, as it relates to localization and dependence on lipid rafts, and discuss considerations for novel therapeutic design.
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Affiliation(s)
- Kathy McGraw
- Division of Clinical Sciences, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, United States.
| | - Alan List
- Division of Clinical Sciences, H. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, United States
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Emerging EPO and EPO receptor regulators and signal transducers. Blood 2015; 125:3536-41. [PMID: 25887776 DOI: 10.1182/blood-2014-11-575357] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 04/13/2015] [Indexed: 12/13/2022] Open
Abstract
As essential mediators of red cell production, erythropoietin (EPO) and its cell surface receptor (EPO receptor [EPOR]) have been intensely studied. Early investigations defined basic mechanisms for hypoxia-inducible factor induction of EPO expression, and within erythroid progenitors EPOR engagement of canonical Janus kinase 2/signal transducer and activator of transcription 5 (JAK2/STAT5), rat sarcoma/mitogen-activated protein kinase/extracellular signal-regulated kinase (RAS/MEK/ERK), and phosphatidylinositol 3-kinase (PI3K) pathways. Contemporary genetic, bioinformatic, and proteomic approaches continue to uncover new clinically relevant modulators of EPO and EPOR expression, and EPO's biological effects. This Spotlight review highlights such factors and their emerging roles during erythropoiesis and anemia.
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