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An C, Xue F, Sun L, Han H, Zhang Y, Hu Y. The impact of erythroblast enucleation efficiency on the severity of anemia in patients with myelodysplastic syndrome. Cell Commun Signal 2023; 21:332. [PMID: 37986081 PMCID: PMC10658927 DOI: 10.1186/s12964-023-01353-4] [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: 08/01/2023] [Accepted: 10/11/2023] [Indexed: 11/22/2023] Open
Abstract
Anemia is the most common manifestation in myelodysplastic syndrome (MDS) patients, but the cause of ineffective hematopoiesis is not fully understood. Enucleation is an important event in the maturation process of erythroblasts. According to a series of morphological phenotypes of the pathological development of MDS erythroblasts, we speculate that there may be enucleation disorders. To verify this hypothesis, we cultured MDS bone marrow CD34+ cells in vitro and induced erythroblast development. The results showed that erythroblast enucleation in MDS was significantly lower than that in the normal group, and the rate of enucleation was positively correlated with hemoglobin concentration. Risk stratification of MDS was performed to further analyze the differences in enucleation among the normal group, low-middle risk group and high-risk group. The results showed that the enucleation rate of the high risk group was higher than that of the low-middle risk group but still lower than that of the normal group. Moreover, the expression of pERK and pAKT in MDS erythroblasts in the high risk group was higher than that in the normal group, while the expression of pERK and pAKT in the low-middle risk group was lower than that in the normal group. Furthermore, the enucleation of MDS was positively correlated with the phosphorylation degree of ERK and AKT. In conclusion, this study reveals that the enucleation of erythroblasts is one of the possible causes of anemia in MDS. Video Abstract.
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Affiliation(s)
- Chao An
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450014, Henan, China.
| | - Fumin Xue
- Henan Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou, 450000, Henan, China
| | - Ling Sun
- Department of Hematology, First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Haiyan Han
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450014, Henan, China
| | - Yali Zhang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450014, Henan, China
| | - Yibo Hu
- Department of Clinical Laboratory, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, 450014, Henan, China.
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2
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Ginzburg Y, An X, Rivella S, Goldfarb A. Normal and dysregulated crosstalk between iron metabolism and erythropoiesis. eLife 2023; 12:e90189. [PMID: 37578340 PMCID: PMC10425177 DOI: 10.7554/elife.90189] [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: 06/16/2023] [Accepted: 08/06/2023] [Indexed: 08/15/2023] Open
Abstract
Erythroblasts possess unique characteristics as they undergo differentiation from hematopoietic stem cells. During terminal erythropoiesis, these cells incorporate large amounts of iron in order to generate hemoglobin and ultimately undergo enucleation to become mature red blood cells, ultimately delivering oxygen in the circulation. Thus, erythropoiesis is a finely tuned, multifaceted process requiring numerous properly timed physiological events to maintain efficient production of 2 million red blood cells per second in steady state. Iron is required for normal functioning in all human cells, the erythropoietic compartment consuming the majority in light of the high iron requirements for hemoglobin synthesis. Recent evidence regarding the crosstalk between erythropoiesis and iron metabolism sheds light on the regulation of iron availability by erythroblasts and the consequences of insufficient as well as excess iron on erythroid lineage proliferation and differentiation. In addition, significant progress has been made in our understanding of dysregulated iron metabolism in various congenital and acquired malignant and non-malignant diseases. Finally, we report several actual as well as theoretical opportunities for translating the recently acquired robust mechanistic understanding of iron metabolism regulation to improve management of patients with disordered erythropoiesis, such as anemia of chronic inflammation, β-thalassemia, polycythemia vera, and myelodysplastic syndromes.
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Affiliation(s)
- Yelena Ginzburg
- Division of Hematology and Medical Oncology, The Tisch Cancer Institute, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Xiuli An
- LFKRI, New York Blood CenterNew YorkUnited States
| | - Stefano Rivella
- Department of Pediatrics, Division of Hematology, The Children’s Hospital of PhiladelphiaPhiladelphiaUnited States
- Cell and Molecular Biology affinity group (CAMB), University of PennsylvaniaPhiladelphiaUnited States
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics at the Children’s Hospital of PhiladelphiaPhiladelphiaUnited States
- Penn Center for Musculoskeletal Disorders at the Children’s Hospital of PhiladelphiaPhiladelphiaUnited States
- Perelman School of Medicine, University of PennsylvaniaPhiladelphiaUnited States
- Institute for Regenerative Medicine at University of PennsylvaniaPhiladelphiaUnited States
- RNA Institute at University of PennsylvaniaPhiladelphiaUnited States
| | - Adam Goldfarb
- Department of Pathology, University of VirginiaCharlottesvilleUnited States
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3
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Tátrai P, Gergely F. Centrosome function is critical during terminal erythroid differentiation. EMBO J 2022; 41:e108739. [PMID: 35678476 PMCID: PMC9289712 DOI: 10.15252/embj.2021108739] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 05/03/2022] [Accepted: 05/25/2022] [Indexed: 11/26/2022] Open
Abstract
Red blood cells are produced by terminal erythroid differentiation, which involves the dramatic morphological transformation of erythroblasts into enucleated reticulocytes. Microtubules are important for enucleation, but it is not known if the centrosome, a key microtubule-organizing center, is required as well. Mice lacking the conserved centrosome component, CDK5RAP2, are likely to have defective erythroid differentiation because they develop macrocytic anemia. Here, we show that fetal liver-derived, CDK5RAP2-deficient erythroid progenitors generate fewer and larger reticulocytes, hence recapitulating features of macrocytic anemia. In erythroblasts, but not in embryonic fibroblasts, loss of CDK5RAP2 or pharmacological depletion of centrosomes leads to highly aberrant spindle morphologies. Consistent with such cells exiting mitosis without chromosome segregation, tetraploidy is frequent in late-stage erythroblasts, thereby giving rise to fewer but larger reticulocytes than normal. Our results define a critical role for CDK5RAP2 and centrosomes in spindle formation specifically during blood production. We propose that disruption of centrosome and spindle function could contribute to the emergence of macrocytic anemias, for instance, due to nutritional deficiency or exposure to chemotherapy.
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Affiliation(s)
- Péter Tátrai
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
- Present address:
Solvo BiotechnologyBudapestHungary
| | - Fanni Gergely
- Cancer Research UK Cambridge InstituteLi Ka Shing CentreUniversity of CambridgeCambridgeUK
- Department of BiochemistryUniversity of OxfordOxfordUK
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4
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Soboleva S, Miharada K. Induction of enucleation in primary and immortalized erythroid cells. Int J Hematol 2022; 116:192-198. [PMID: 35610497 DOI: 10.1007/s12185-022-03386-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/02/2022] [Accepted: 05/06/2022] [Indexed: 10/18/2022]
Abstract
Enucleation is a crucial event during the erythropoiesis, implicating drastic morphologic and transcriptomic/proteomic changes. While many genes deletion lead to failed or impaired enucleation have been identified, directly triggering the erythroid maturation, particularly enucleation, is still challenging. Inducing enucleation at the desired timing is necessary to develop efficient methods to generate mature, fully functional red blood cells in vitro for future transfusion therapies. However, there are considerable differences between primary erythroid cells and cultured cell sources, particularly pluripotent stem cell-derived erythroid cells and immortalized erythroid cell lines. For instance, the difference in the proliferative status between those cell types could be a critical factor, as cell cycle exit is closely connected to the terminal maturation of primary. In this review, we will discuss previous findings on the enucleation machinery and current challengings to trigger the enucleation of infinite erythroid cell sources.
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Affiliation(s)
- Svetlana Soboleva
- Division of Molecular Medicine and Gene Therapy, Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Kenichi Miharada
- Division of Molecular Medicine and Gene Therapy, Lund Stem Cell Center, Lund University, Lund, Sweden. .,International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan.
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5
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Ulyanova T, Cherone JM, Sova P, Papayannopoulou T. α4-Integrin deficiency in human CD34+ cells engenders precocious erythroid differentiation but inhibits enucleation. Exp Hematol 2022; 108:16-25. [DOI: 10.1016/j.exphem.2022.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/21/2022] [Accepted: 01/25/2022] [Indexed: 11/26/2022]
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6
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Buks R, Dagher T, Rotordam MG, Monedero Alonso D, Cochet S, Gautier EF, Chafey P, Cassinat B, Kiladjian JJ, Becker N, Plo I, Egée S, El Nemer W. Altered Ca 2+ Homeostasis in Red Blood Cells of Polycythemia Vera Patients Following Disturbed Organelle Sorting during Terminal Erythropoiesis. Cells 2021; 11:49. [PMID: 35011611 PMCID: PMC8750512 DOI: 10.3390/cells11010049] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 02/07/2023] Open
Abstract
Over 95% of Polycythemia Vera (PV) patients carry the V617F mutation in the tyrosine kinase Janus kinase 2 (JAK2), resulting in uncontrolled erythroid proliferation and a high risk of thrombosis. Using mass spectrometry, we analyzed the RBC membrane proteome and showed elevated levels of multiple Ca2+ binding proteins as well as endoplasmic-reticulum-residing proteins in PV RBC membranes compared with RBC membranes from healthy individuals. In this study, we investigated the impact of JAK2V617F on (1) calcium homeostasis and RBC ion channel activity and (2) protein expression and sorting during terminal erythroid differentiation. Our data from automated patch-clamp show modified calcium homeostasis in PV RBCs and cell lines expressing JAK2V617F, with a functional impact on the activity of the Gárdos channel that could contribute to cellular dehydration. We show that JAK2V617F could play a role in organelle retention during the enucleation step of erythroid differentiation, resulting in modified whole cell proteome in reticulocytes and RBCs in PV patients. Given the central role that calcium plays in the regulation of signaling pathways, our study opens new perspectives to exploring the relationship between JAK2V617F, calcium homeostasis, and cellular abnormalities in myeloproliferative neoplasms, including cellular interactions in the bloodstream in relation to thrombotic events.
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Affiliation(s)
- Ralfs Buks
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
| | - Tracy Dagher
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- U1287, Inserm, Université Paris-Saclay, Gustave Roussy, F-94800 Villejuif, France
| | - Maria Giustina Rotordam
- Nanion Technologies GmbH, 80339 Munich, Germany; (M.G.R.); (N.B.)
- Theoretical Medicine and Biosciences, Medical Faculty, Saarland University, Kirrbergerstr. 100, DE-66424 Homburg, Germany
| | - David Monedero Alonso
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Sorbonne Université, CNRS, UMR LBI2M, Station Biologique de Roscoff SBR, F-29680 Roscoff, France
| | - Sylvie Cochet
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
| | - Emilie-Fleur Gautier
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Institut Imagine-INSERM U1163, Necker Hospital, Université de Paris, F-75015 Paris, France
- Proteomics Platform 3P5, Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104 Paris, France;
| | - Philippe Chafey
- Proteomics Platform 3P5, Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104 Paris, France;
| | - Bruno Cassinat
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- IRSL, U1131, INSERM, Université de Paris, F-75010 Paris, France
- Hôpital Saint-Louis, Laboratoire de Biologie Cellulaire, AP-HP, F-75010 Paris, France
| | - Jean-Jacques Kiladjian
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- IRSL, U1131, INSERM, Université de Paris, F-75010 Paris, France
- Centre d’Investigations Cliniques, Hôpital Saint-Louis, Université de Paris, F-75010 Paris, France
| | - Nadine Becker
- Nanion Technologies GmbH, 80339 Munich, Germany; (M.G.R.); (N.B.)
| | - Isabelle Plo
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- U1287, Inserm, Université Paris-Saclay, Gustave Roussy, F-94800 Villejuif, France
| | - Stéphane Egée
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Sorbonne Université, CNRS, UMR LBI2M, Station Biologique de Roscoff SBR, F-29680 Roscoff, France
| | - Wassim El Nemer
- BIGR, UMR_S1134, Inserm, Université de Paris, F-75015 Paris, France; (R.B.); (S.C.)
- Institut National de la Transfusion Sanguine, F-75015 Paris, France
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France; (T.D.); (D.M.A.); (E.-F.G.); (B.C.); (J.-J.K.); (I.P.); (S.E.)
- Etablissement Français du Sang PACA-Corse, F-13005Marseille, France
- Aix Marseille Univ, EFS, CNRS, ADES, “Biologie des Groupes Sanguins”, F-13005 Marseille, France
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7
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Vesicular formation regulated by ERK/MAPK pathway mediates human erythroblast enucleation. Blood Adv 2021; 5:4648-4661. [PMID: 34551066 PMCID: PMC8759143 DOI: 10.1182/bloodadvances.2021004859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 07/17/2021] [Indexed: 11/20/2022] Open
Abstract
ERK pathway plays a key role in enucleation of human orthochromatic erythroblasts. ERK regulates human erythroblast enucleation by affecting vesicular formation.
Enucleation is a key event in mammalian erythropoiesis responsible for the generation of enucleated reticulocytes. Although progress is being made in developing mechanistic understanding of enucleation, our understanding of mechanisms for enucleation is still incomplete. The MAPK pathway plays diverse roles in biological processes, but its role in erythropoiesis has yet to be fully defined. Analysis of RNA-sequencing data revealed that the MAPK pathway is significantly upregulated during human terminal erythroid differentiation. The MAPK pathway consists of 3 major signaling cassettes: MEK/ERK, p38, and JNK. In the present study, we show that among these 3 cassettes, only ERK was significantly upregulated in late-stage human erythroblasts. The increased expression of ERK along with its increased phosphorylation suggests a potential role for ERK activation in enucleation. To explore this hypothesis, we treated sorted populations of human orthochromatic erythroblasts with the MEK/ERK inhibitor U0126 and found that U0126 inhibited enucleation. In contrast, inhibitors of either p38 or JNK had no effect on enucleation. Mechanistically, U0126 selectively inhibited formation/accumulation of cytoplasmic vesicles and endocytosis of the transferrin receptor without affecting chromatin condensation, nuclear polarization, or enucleosome formation. Treatment with vacuolin-1 that induces vacuole formation partially rescued the blockage of enucleation by U0126. Moreover, phosphoproteomic analysis revealed that inactivation of the ERK pathway led to downregulation of the endocytic recycling pathway. Collectively, our findings uncovered a novel role of ERK activation in human erythroblast enucleation by modulating vesicle formation and have implications for understanding anemia associated with defective enucleation.
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Ito N, Tsukamoto K, Taniguchi K, Takahashi K, Okamoto A, Aoki H, Otera‐Takahashi Y, Kitagawa M, Ogata‐Kawata H, Morita H, Hata K, Nakabayashi K. Isolation and characterization of fetal nucleated red blood cells from maternal blood as a target for single cell sequencing-based non-invasive genetic testing. Reprod Med Biol 2021; 20:352-360. [PMID: 34262404 PMCID: PMC8254165 DOI: 10.1002/rmb2.12392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/12/2021] [Accepted: 05/20/2021] [Indexed: 01/04/2023] Open
Abstract
PURPOSE Although non-invasive prenatal testing (NIPT) based on cell-free DNA (cfDNA) in maternal plasma has been prevailing worldwide, low levels of fetal DNA fraction may lead to false-negative results. Since fetal cells in maternal blood provide a pure source of fetal genomic DNA, we aimed to establish a workflow to isolate and sequence fetal nucleated red blood cells (fNRBCs) individually as a target for NIPT. METHODS Using male-bearing pregnancy cases, we isolated fNRBCs individually from maternal blood by FACS, and obtained their genomic sequence data through PCR screening with a Y-chromosome marker and whole-genome amplification (WGA)-based whole-genome sequencing. RESULTS The PCR and WGA efficiencies of fNRBC candidates were consistently lower than those of control cells. Sequencing data analyses revealed that although the majority of the fNRBC candidates were confirmed to be of fetal origin, many of the WGA-based genomic libraries from fNRBCs were considered to have been amplified from a portion of genomic DNA. CONCLUSIONS We established a workflow to isolate and sequence fNRBCs individually. However, our results demonstrated that, to make cell-based NIPT targeting fNRBCs feasible, cell isolation procedures need to be further refined such that the nuclei of fNRBCs are kept intact.
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Affiliation(s)
- Noriko Ito
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
- Department of Pharmacotherapeutics, Course of Medical and Dental SciencesNagasaki University Graduate School of Biomedical SciencesNagasakiJapan
| | - Kazuhiro Tsukamoto
- Department of Pharmacotherapeutics, Course of Medical and Dental SciencesNagasaki University Graduate School of Biomedical SciencesNagasakiJapan
| | - Kosuke Taniguchi
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Ken Takahashi
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
- Department of Obstetrics and GynecologyThe Jikei University School of MedicineTokyoJapan
| | - Aikou Okamoto
- Department of Obstetrics and GynecologyThe Jikei University School of MedicineTokyoJapan
| | | | | | | | - Hiroko Ogata‐Kawata
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Hideaki Morita
- Department of Allergy and Clinical ImmunologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Kenichiro Hata
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
| | - Kazuhiko Nakabayashi
- Department of Maternal‐Fetal BiologyNational Center for Child Health and DevelopmentTokyoJapan
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Mei Y, Liu Y, Ji P. Understanding terminal erythropoiesis: An update on chromatin condensation, enucleation, and reticulocyte maturation. Blood Rev 2021; 46:100740. [PMID: 32798012 DOI: 10.1016/j.blre.2020.100740] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/02/2020] [Accepted: 08/05/2020] [Indexed: 12/19/2022]
Abstract
A characteristic feature of terminal erythropoiesis in mammals is extrusion of the highly condensed nucleus out of the cytoplasm. Other vertebrates, including fish, reptiles, amphibians, and birds, undergo nuclear condensation but do not enucleate. Enucleation provides mammals evolutionary advantages by gaining extra space for hemoglobin and being more flexible to migrate through capillaries. Nascent reticulocytes further mature into red blood cells through membrane and proteome remodeling and organelle clearance. Over the past decade, novel molecular mechanisms and signaling pathways have been uncovered that play important roles in chromatin condensation, enucleation, and reticulocyte maturation. These advances not only increase understanding of the physiology of erythropoiesis, but also facilitate efforts in generating in vitro red blood cells for various translational application. In the present review, recent studies in epigenetic modification and release of histones during chromatin condensation are highlighted. New insights in enucleation, including protein sorting, vesicle trafficking, transcriptional regulation, noncoding RNA, cytoskeleton remodeling, erythroblastic islands, and cytokinesis, are summarized. Moreover, organelle clearance and proteolysis mediated by ubiquitin-proteasome degradation during reticulocytes maturation is also examined. Perspectives for future directions in this rapidly evolving research area are also provided.
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Affiliation(s)
- Yang Mei
- Department of Pathology, Northwestern University, Chicago, IL, USA.
| | - Yijie Liu
- Department of Pathology, Northwestern University, Chicago, IL, USA.
| | - Peng Ji
- Department of Pathology, Northwestern University, Chicago, IL, USA.
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10
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Abstract
Generation of mature red blood cells, consisting mainly of hemoglobin, is a remarkable example of coordinated action of various signaling networks. Chromatin condensation is an essential step for terminal erythroid differentiation and subsequent nuclear expulsion in mammals. Here, we profiled 3D genome organization in the blood cells from ten species belonging to different vertebrate classes. Our analysis of contact maps revealed a striking absence of such 3D interaction patterns as loops or TADs in blood cells of all analyzed representatives. We also detect large-scale chromatin rearrangements in blood cells from mammals, birds, reptiles and amphibians: their contact maps display strong second diagonal pattern, representing an increased frequency of long-range contacts, unrelated to TADs or compartments. This pattern is completely atypical for interphase chromosome structure. We confirm that these principles of genome organization are conservative in vertebrate erythroid cells.
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11
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Moras M, Hattab C, Gonzalez-Menendez P, Fader CM, Dussiot M, Larghero J, Le Van Kim C, Kinet S, Taylor N, Lefevre SD, Ostuni MA. Human erythroid differentiation requires VDAC1-mediated mitochondrial clearance. Haematologica 2021; 107:167-177. [PMID: 33406813 PMCID: PMC8719069 DOI: 10.3324/haematol.2020.257121] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Indexed: 11/10/2022] Open
Abstract
Erythroblast maturation in mammals is dependent on organelle clearance throughout terminal erythropoiesis. We studied the role of the outer mitochondrial membrane protein voltage-dependent anion channel-1 (VDAC1) in human terminal erythropoiesis. We show that short hairpin (shRNA)-mediated downregulation of VDAC1 accelerates erythroblast maturation. Thereafter, erythroblasts are blocked at the orthochromatic stage, exhibiting a significant decreased level of enucleation, concomitant with an increased cell death. We demonstrate that mitochondria clearance starts at the transition from basophilic to polychromatic erythroblast, and that VDAC1 downregulation induces the mitochondrial retention. In damaged mitochondria from non-erythroid cells, VDAC1 was identified as a target for Parkin-mediated ubiquitination to recruit the phagophore. Here, we showed that VDAC1 is involved in phagophore’s membrane recruitment regulating selective mitophagy of still functional mitochondria from human erythroblasts. These findings demonstrate for the first time a crucial role for VDAC1 in human erythroblast terminal differentiation, regulating mitochondria clearance.
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Affiliation(s)
- Martina Moras
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de Transfusion Sanguine, F-75015 Paris, France; Laboratoire d'Excellence GR-Ex, F-75015, Paris
| | - Claude Hattab
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de Transfusion Sanguine, F-75015 Paris, France; Laboratoire d'Excellence GR-Ex, F-75015, Paris
| | - Pedro Gonzalez-Menendez
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France; Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier
| | - Claudio M Fader
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM), Universidad Nacional de Cuyo, CONICET, Mendoza, Argentina; Facultad de Odontología, Universidad Nacional de Cuyo, Mendoza
| | - Michael Dussiot
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France; Université de Paris, UMR_S1163, Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutical Implication, Inserm, F-75014 Paris
| | - Jerome Larghero
- AP-HP, Hôpital Saint-Louis, Unité de Thérapie cellulaire, Paris
| | - Caroline Le Van Kim
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de Transfusion Sanguine, F-75015 Paris, France; Laboratoire d'Excellence GR-Ex, F-75015, Paris
| | - Sandrina Kinet
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France; Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier
| | - Naomi Taylor
- Laboratoire d'Excellence GR-Ex, F-75015, Paris, France; Institut de Génétique Moléculaire de Montpellier, Univ Montpellier, CNRS, Montpellier, France; Pediatric Oncology Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, Maryland
| | - Sophie D Lefevre
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de Transfusion Sanguine, F-75015 Paris, France; Laboratoire d'Excellence GR-Ex, F-75015, Paris.
| | - Mariano A Ostuni
- Université de Paris, UMR_S1134, BIGR, Inserm, F-75015 Paris, France; Institut National de Transfusion Sanguine, F-75015 Paris, France; Laboratoire d'Excellence GR-Ex, F-75015, Paris.
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12
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Ubukawa K, Goto T, Asanuma K, Sasaki Y, Guo YM, Kobayashi I, Sawada K, Wakui H, Takahashi N. Cdc42 regulates cell polarization and contractile actomyosin rings during terminal differentiation of human erythroblasts. Sci Rep 2020; 10:11806. [PMID: 32678227 PMCID: PMC7366696 DOI: 10.1038/s41598-020-68799-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/02/2020] [Indexed: 11/24/2022] Open
Abstract
The molecular mechanisms involved in the terminal differentiation of erythroblasts have been elucidated by comparing enucleation and cell division. Although various similarities and differences between erythroblast enucleation and cytokinesis have been reported, the mechanisms that control enucleation remain unclear. We previously reported that dynein and microtubule-organizing centers mediated the polarization of nuclei in human erythroblasts. Moreover, the accumulation of F-actin was noted during the enucleation of erythroblasts. Therefore, during enucleation, upstream effectors in the signal transduction pathway regulating dynein or actin, such as cell division control protein 42 homolog (Cdc42), may be crucial. We herein investigated the effects of the Cdc42 inhibitor, CASIN, on cytokinesis and enucleation in colony-forming units-erythroid (CFU-Es) and mature erythroblasts (day 10). CASIN blocked the proliferation of CFU-Es and their enucleation in a dose-dependent manner. Dynein adopted an island-like distribution in the cytoplasm of non-treated CFU-Es, but was concentrated near the nucleus as a dot and co-localized with γ-tubulin in CASIN-treated cells. CASIN blocked the accumulation of F-actin in CFU-Es and day 10 cells. These results demonstrated that Cdc42 plays an important role in cytokinesis, nuclear polarization and nuclear extrusion through a relationship with dynein and actin filament organization during the terminal differentiation of erythroblasts.
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Affiliation(s)
- Kumi Ubukawa
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan.
| | - Tatsufumi Goto
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan
| | - Ken Asanuma
- Division of Radio Isotope, Bioscience Education and Research Support Center, Akita University, Akita, Japan
| | - Yumi Sasaki
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan
| | - Yong-Mei Guo
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | - Isuzu Kobayashi
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | | | - Hideki Wakui
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan
| | - Naoto Takahashi
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
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13
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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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14
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Yeo JH, Lam YW, Fraser ST. Cellular dynamics of mammalian red blood cell production in the erythroblastic island niche. Biophys Rev 2019; 11:873-894. [PMID: 31418139 PMCID: PMC6874942 DOI: 10.1007/s12551-019-00579-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/08/2019] [Indexed: 12/12/2022] Open
Abstract
Red blood cells, or erythrocytes, make up approximately a quarter of all cells in the human body with over 2 billion new erythrocytes made each day in a healthy adult human. This massive cellular production system is coupled with a set of cell biological processes unique to mammals, in particular, the elimination of all organelles, and the expulsion and destruction of the condensed erythroid nucleus. Erythrocytes from birds, reptiles, amphibians and fish possess nuclei, mitochondria and other organelles: erythrocytes from mammals lack all of these intracellular components. This review will focus on the dynamic changes that take place in developing erythroid cells that are interacting with specialized macrophages in multicellular clusters termed erythroblastic islands. Proerythroblasts enter the erythroblastic niche as large cells with active nuclei, mitochondria producing heme and energy, and attach to the central macrophage via a range of adhesion molecules. Proerythroblasts then mature into erythroblasts and, following enucleation, in reticulocytes. When reticulocytes exit the erythroblastic island, they are smaller cells, without nuclei and with few mitochondria, possess some polyribosomes and have a profoundly different surface molecule phenotype. Here, we will review, step-by-step, the biophysical mechanisms that regulate the remarkable process of erythropoiesis with a particular focus on the events taking place in the erythroblastic island niche. This is presented from the biological perspective to offer insight into the elements of red blood cell development in the erythroblastic island niche which could be further explored with biophysical modelling systems.
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Affiliation(s)
- Jia Hao Yeo
- Discipline of Anatomy and Histology, School of Medical Sciences, University of Sydney, Sydney, Australia.
- School of Chemistry, University of Sydney, Sydney, Australia.
- Discipline of Physiology, School of Medical Sciences, University of Sydney, Sydney, Australia.
| | - Yun Wah Lam
- Department of Chemistry, City University of Hong Kong, Kowloon Tong, Hong Kong
| | - Stuart T Fraser
- Discipline of Anatomy and Histology, School of Medical Sciences, University of Sydney, Sydney, Australia.
- Discipline of Physiology, School of Medical Sciences, University of Sydney, Sydney, Australia.
- Bosch Institute, School of Medical Sciences, University of Sydney, Sydney, Australia.
- University of Sydney Nano Institute, Sydney, Australia.
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15
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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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16
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Goto T, Ubukawa K, Kobayashi I, Sugawara K, Asanuma K, Sasaki Y, Guo YM, Takahashi N, Sawada K, Wakui H, Nunomura W. ATP produced by anaerobic glycolysis is essential for enucleation of human erythroblasts. Exp Hematol 2019; 72:14-26.e1. [PMID: 30797950 DOI: 10.1016/j.exphem.2019.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 02/13/2019] [Accepted: 02/18/2019] [Indexed: 11/16/2022]
Abstract
More than 2million human erythroblasts extrude their nuclei every second in bone marrow under hypoxic conditions (<7% O2). Enucleation requires specific signal transduction pathways and the local assembly of contractile actomyosin rings. However, the energy source driving these events has not yet been identified. We examined whether different O2 environments (hypoxic [5% O2] and normoxic [21% O2] conditions) affected human CD34+ cell erythroblast differentiation. We also investigated the regulatory mechanisms underlying energy production in erythroblasts during terminal differentiation under 5% or 21% O2 conditions. The results obtained revealed that the enucleation ratio and intracellular levels of adenosine triphosphate (ATP), lactate dehydrogenase (LDH) M3H, and hypoxia-inducible factor 1α in erythroblasts during terminal differentiation were higher under the 5% O2 condition than under the 21% O2 condition. We also found that the enzymatic inhibition of glyceraldehyde 3-phosphate dehydrogenase and LDH, key enzymes in anaerobic glycolysis, blocked the proliferation of colony-forming units-erythroid and enucleation of erythroblasts, and also reduced ATP levels in erythroblasts under both hypoxic and normoxic conditions. Under both conditions, phosphorylation of the Ser232, Ser293, and Ser300 residues in pyruvate dehydrogenase (inactive state of the enzyme) in erythroblasts was involved in regulating the pathway governing energy metabolism during erythroid terminal differentiation. This reaction may be mediated by pyruvate dehydrogenase kinase (PDK) 4, the major PDK isozyme expressed in erythroblasts undergoing enucleation. Collectively, these results suggest that ATP produced by anaerobic glycolysis is the main source of energy for human erythroblast enucleation in the hypoxic bone marrow environment.
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Affiliation(s)
- Tatsufumi Goto
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan
| | - Kumi Ubukawa
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | - Isuzu Kobayashi
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | - Kotomi Sugawara
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | - Ken Asanuma
- Division of Radio Isotope, Bioscience Education and Research Support Center, Akita University, Akita, Japan
| | - Yumi Sasaki
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan
| | - Yong-Mei Guo
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | - Naoto Takahashi
- Department of Hematology, Nephrology, and Rheumatology, Graduate School of Medicine, Akita University, Akita, Japan
| | | | - Hideki Wakui
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan.
| | - Wataru Nunomura
- Department of Life Science, Graduate School of Engineering Science, Akita University, Akita, Japan; Research Center for Engineering Science, Graduate School of Engineering Science, Akita University, Akita, Japan
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17
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Aoto M, Iwashita A, Mita K, Ohkubo N, Tsujimoto Y, Mitsuda N. Transferrin receptor 1 is required for enucleation of mouse erythroblasts during terminal differentiation. FEBS Open Bio 2019; 9:291-303. [PMID: 30761254 PMCID: PMC6356176 DOI: 10.1002/2211-5463.12573] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 12/04/2018] [Accepted: 12/04/2018] [Indexed: 12/25/2022] Open
Abstract
Enucleation is the process whereby the nucleus is extruded from the erythroblast during late stage mammalian erythropoiesis. However, the specific signaling pathways involved in this process remain unclear. To better understand the mechanisms underlying erythroblast enucleation, we investigated erythroblast enucleation using both the spleens of adult mice with phenylhydrazine‐induced anemia and mouse fetal livers. Our results indicated that both iron‐bound transferrin (holo‐Tf) and the small‐molecule iron transporter hinokitiol with iron ions (hinokitiol plus iron) promote hemoglobin synthesis and the enucleation of mouse spleen‐derived erythroblasts. Although an antitransferrin receptor 1 (TfR1) monoclonal antibody inhibited both enucleation and hemoglobin synthesis promoted by holo‐Tf, it inhibited only enucleation, but not hemoglobin synthesis, promoted by hinokitiol plus iron. Furthermore, siRNA against mouse TfR1 were found to suppress the enucleation of mouse fetal liver‐derived erythroblasts, and the endocytosis inhibitor MitMAB inhibited enucleation, hemoglobin synthesis, and the internalization of TfR1 promoted by both types of stimuli. Collectively, our results suggest that TfR1, iron ions, and endocytosis play important roles in mouse erythroblast enucleation.
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Affiliation(s)
- Mamoru Aoto
- Department of Circulatory Physiology Graduate School of Medicine Ehime University Japan
| | - Akiho Iwashita
- Department of Circulatory Physiology Graduate School of Medicine Ehime University Japan
| | - Kanako Mita
- Department of Circulatory Physiology Graduate School of Medicine Ehime University Japan
| | - Nobutaka Ohkubo
- Department of Circulatory Physiology Graduate School of Medicine Ehime University Japan
| | - Yoshihide Tsujimoto
- Department of Molecular and Cellular Biology Research Center Osaka International Cancer Institute Japan
| | - Noriaki Mitsuda
- Department of Circulatory Physiology Graduate School of Medicine Ehime University Japan
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18
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Ovchynnikova E, Aglialoro F, von Lindern M, van den Akker E. The Shape Shifting Story of Reticulocyte Maturation. Front Physiol 2018; 9:829. [PMID: 30050448 PMCID: PMC6050374 DOI: 10.3389/fphys.2018.00829] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/12/2018] [Indexed: 12/11/2022] Open
Abstract
The final steps of erythropoiesis involve unique cellular processes including enucleation and reorganization of membrane proteins and the cytoskeleton to produce biconcave erythrocytes. Surprisingly this process is still poorly understood. In vitro erythropoiesis protocols currently produce reticulocytes rather than biconcave erythrocytes. In addition, immortalized lines and iPSC-derived erythroid cell suffer from low enucleation and suboptimal final maturation potential. In light of the increasing prospect to use in vitro produced erythrocytes as (personalized) transfusion products or as therapeutic delivery agents, the mechanisms driving this last step of erythropoiesis are in dire need of resolving. Here we review the elusive last steps of reticulocyte maturation with an emphasis on protein sorting during the defining steps of reticulocyte formation during enucleation and maturation.
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Affiliation(s)
- Elina Ovchynnikova
- Department of Hematopoiesis, Sanquin Research, Amsterdam, Netherlands.,Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Francesca Aglialoro
- Department of Hematopoiesis, Sanquin Research, Amsterdam, Netherlands.,Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Marieke von Lindern
- Department of Hematopoiesis, Sanquin Research, Amsterdam, Netherlands.,Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Emile van den Akker
- Department of Hematopoiesis, Sanquin Research, Amsterdam, Netherlands.,Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
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19
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Moras M, Lefevre SD, Ostuni MA. From Erythroblasts to Mature Red Blood Cells: Organelle Clearance in Mammals. Front Physiol 2017; 8:1076. [PMID: 29311991 PMCID: PMC5742207 DOI: 10.3389/fphys.2017.01076] [Citation(s) in RCA: 175] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022] Open
Abstract
Erythropoiesis occurs mostly in bone marrow and ends in blood stream. Mature red blood cells are generated from multipotent hematopoietic stem cells, through a complex maturation process involving several morphological changes to produce a highly functional specialized cells. In mammals, terminal steps involved expulsion of the nucleus from erythroblasts that leads to the formation of reticulocytes. In order to produce mature biconcave red blood cells, organelles and ribosomes are selectively eliminated from reticulocytes as well as the plasma membrane undergoes remodeling. The mechanisms involved in these last maturation steps are still under investigation. Enucleation involves dramatic chromatin condensation and establishment of the nuclear polarity, which is driven by a rearrangement of actin cytoskeleton and the clathrin-dependent generation of vacuoles at the nuclear-cytoplasmic junction. This process is favored by interaction between the erythroblasts and macrophages at the erythroblastic island. Mitochondria are eliminated by mitophagy. This is a macroautophagy pathway consisting in the engulfment of mitochondria into a double-membrane structure called autophagosome before degradation. Several mice knock-out models were developed to identify mitophagy-involved proteins during erythropoiesis, but whole mechanisms are not completely determined. Less is known concerning the clearance of other organelles, such as smooth and rough ER, Golgi apparatus and ribosomes. Understanding the modulators of organelles clearance in erythropoiesis may elucidate the pathogenesis of different dyserythropoietic diseases such as myelodysplastic syndrome, leukemia and anemia.
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Affiliation(s)
| | | | - Mariano A. Ostuni
- UMR-S1134 Integrated Biology of Red Blood Cell, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, Paris, France
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20
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Javan GT, Salhotra A, Finley SJ, Soni S. Erythroblast macrophage protein (Emp): Past, present, and future. Eur J Haematol 2017; 100:3-9. [DOI: 10.1111/ejh.12983] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Gulnaz T. Javan
- Physical Sciences Department Forensic Science Program Alabama State University Montgomery AL USA
| | | | - Sheree J. Finley
- Physical Sciences Department Alabama State University Montgomery AL USA
| | - Shivani Soni
- Department of Biological Sciences California State University Fullerton CA USA
- Department of Biological Science Schmid College of Science and Technology Chapman University Irvine CA USA
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21
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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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22
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Wölwer CB, Gödde N, Pase LB, Elsum IA, Lim KYB, Sacirbegovic F, Walkley CR, Ellis S, Ohno S, Matsuzaki F, Russell SM, Humbert PO. The Asymmetric Cell Division Regulators Par3, Scribble and Pins/Gpsm2 Are Not Essential for Erythroid Development or Enucleation. PLoS One 2017; 12:e0170295. [PMID: 28095473 PMCID: PMC5240992 DOI: 10.1371/journal.pone.0170295] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/03/2017] [Indexed: 12/30/2022] Open
Abstract
Erythroid enucleation is the process by which the future red blood cell disposes of its nucleus prior to entering the blood stream. This key event during red blood cell development has been likened to an asymmetric cell division (ACD), by which the enucleating erythroblast divides into two very different daughter cells of alternate molecular composition, a nucleated cell that will be removed by associated macrophages, and the reticulocyte that will mature to the definitive erythrocyte. Here we investigated gene expression of members of the Par, Scribble and Pins/Gpsm2 asymmetric cell division complexes in erythroid cells, and functionally tested their role in erythroid enucleation in vivo and ex vivo. Despite their roles in regulating ACD in other contexts, we found that these polarity regulators are not essential for erythroid enucleation, nor for erythroid development in vivo. Together our results put into question a role for cell polarity and asymmetric cell division in erythroid enucleation.
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Affiliation(s)
- Christina B. Wölwer
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, East Melbourne, Australia
- La Trobe Institute for Molecular Science, Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia
| | - Nathan Gödde
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, East Melbourne, Australia
- La Trobe Institute for Molecular Science, Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia
| | - Luke B. Pase
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Imogen A. Elsum
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, East Melbourne, Australia
| | - Krystle Y. B. Lim
- La Trobe Institute for Molecular Science, Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia
| | - Faruk Sacirbegovic
- Immune Signaling Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Australia
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
| | - Carl R. Walkley
- St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia
- Department of Medicine, St. Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria
| | - Sarah Ellis
- Immune Signaling Laboratory, Peter MacCallum Cancer Centre, East Melbourne, Australia
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
| | - Shigeo Ohno
- Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Japan
| | - Fumio Matsuzaki
- Laboratory for Cell Asymmetry, RIKEN Center for Developmental Biology, Kobe, Japan
| | - Sarah M. Russell
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
- Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Australia
| | - Patrick O. Humbert
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, East Melbourne, Australia
- La Trobe Institute for Molecular Science, Department of Biochemistry and Genetics, La Trobe University, Melbourne, Australia
- Department of Pathology, University of Melbourne, Parkville, Victoria, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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23
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EKLF/KLF1-regulated cell cycle exit is essential for erythroblast enucleation. Blood 2016; 128:1631-41. [PMID: 27480112 DOI: 10.1182/blood-2016-03-706671] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 07/22/2016] [Indexed: 12/18/2022] Open
Abstract
The mechanisms regulating the sequential steps of terminal erythroid differentiation remain largely undefined, yet are relevant to human anemias that are characterized by ineffective red cell production. Erythroid Krüppel-like Factor (EKLF/KLF1) is a master transcriptional regulator of erythropoiesis that is mutated in a subset of these anemias. Although EKLF's function during early erythropoiesis is well studied, its role during terminal differentiation has been difficult to functionally investigate due to the impaired expression of relevant cell surface markers in Eklf(-/-) erythroid cells. We have circumvented this problem by an innovative use of imaging flow cytometry to investigate the role of EKLF in vivo and have performed functional studies using an ex vivo culture system that enriches for terminally differentiating cells. We precisely define a previously undescribed block during late terminal differentiation at the orthochromatic erythroblast stage for Eklf(-/-) cells that proceed beyond the initial stall at the progenitor stage. These cells efficiently decrease cell size, condense their nucleus, and undergo nuclear polarization; however, they display a near absence of enucleation. These late-stage Eklf(-/-) cells continue to cycle due to low-level expression of p18 and p27, a new direct target of EKLF. Surprisingly, both cell cycle and enucleation deficits are rescued by epistatic reintroduction of either of these 2 EKLF target cell cycle inhibitors. We conclude that the cell cycle as regulated by EKLF during late stages of differentiation is inherently critical for enucleation of erythroid precursors, thereby demonstrating a direct functional relationship between cell cycle exit and nuclear expulsion.
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Erythroblast enucleation is a dynein-dependent process. Exp Hematol 2015; 44:247-56.e12. [PMID: 26724640 DOI: 10.1016/j.exphem.2015.12.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/14/2015] [Accepted: 12/17/2015] [Indexed: 01/01/2023]
Abstract
Mammalian erythroblasts undergo enucleation through a process thought to be similar to cytokinesis. Microtubule-organizing centers (MTOCs) mediate organization of the mitotic spindle apparatus that separates the chromosomes during mitosis and are known to be crucial for proper cytokinesis. However, the role of MTOCs in erythroblast enucleation remains unknown. We therefore investigated the effect of various MTOC inhibitors on cytokinesis and enucleation using human colony-forming units-erythroid (CFU-Es) and mature erythroblasts generated from purified CD34(+) cells. We found that erythro-9-[3-(2-hydroxynonyl)]adenine (EHNA), a dynein inhibitor, and monastrol, a kinesin Eg5 inhibitor, as well as various inhibitors of MTOC regulators, including ON-01910 (Plk-1), MLN8237 (aurora A), hesperadin (aurora B), and LY294002 (PI3K), all inhibited CFU-E cytokinesis. Among these inhibitors, however, only EHNA blocked enucleation. Moreover, terminally differentiated erythroblasts expressed only dynein; little or none of the other tested proteins was detected. Over the course of the terminal differentiation of human erythroblasts, the fraction of cells with nuclei at the cell center declined, whereas the fraction of polarized cells, with nuclei shifted to a position near the plasma membrane, increased. Dynein inhibition impaired nuclear polarization, thereby blocking enucleation. These data indicate that dynein plays an essential role not only in cytokinesis but also in enucleation. We therefore conclude that human erythroblast enucleation is a process largely independent of MTOCs, but dependent on dynein.
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Wölwer CB, Pase LB, Pearson HB, Gödde NJ, Lackovic K, Huang DCS, Russell SM, Humbert PO. A Chemical Screening Approach to Identify Novel Key Mediators of Erythroid Enucleation. PLoS One 2015; 10:e0142655. [PMID: 26569102 PMCID: PMC4646491 DOI: 10.1371/journal.pone.0142655] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/26/2015] [Indexed: 01/06/2023] Open
Abstract
Erythroid enucleation is critical for terminal differentiation of red blood cells, and involves extrusion of the nucleus by orthochromatic erythroblasts to produce reticulocytes. Due to the difficulty of synchronizing erythroblasts, the molecular mechanisms underlying the enucleation process remain poorly understood. To elucidate the cellular program governing enucleation, we utilized a novel chemical screening approach whereby orthochromatic cells primed for enucleation were enriched ex vivo and subjected to a functional drug screen using a 324 compound library consisting of structurally diverse, medicinally active and cell permeable drugs. Using this approach, we have confirmed the role of HDACs, proteasomal regulators and MAPK in erythroid enucleation and introduce a new role for Cyclin-dependent kinases, in particular CDK9, in this process. Importantly, we demonstrate that when coupled with imaging analysis, this approach provides a powerful means to identify and characterize rate limiting steps involved in the erythroid enucleation process.
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Affiliation(s)
- Christina B. Wölwer
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Luke B. Pase
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Helen B. Pearson
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Nathan J. Gödde
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
| | - Kurt Lackovic
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - David C. S. Huang
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Sarah M. Russell
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
- Immune Signaling Laboratory, Peter MacCallum Cancer Centre, Melbourne, Australia
- Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, Hawthorn, Australia
| | - Patrick O. Humbert
- Cell Cycle and Cancer Genetics, Peter MacCallum Cancer Centre, Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Australia
- Department of Pathology, University of Melbourne, Melbourne, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
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A Systems Approach Identifies Essential FOXO3 Functions at Key Steps of Terminal Erythropoiesis. PLoS Genet 2015; 11:e1005526. [PMID: 26452208 PMCID: PMC4599908 DOI: 10.1371/journal.pgen.1005526] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/24/2015] [Indexed: 12/26/2022] Open
Abstract
Circulating red blood cells (RBCs) are essential for tissue oxygenation and homeostasis. Defective terminal erythropoiesis contributes to decreased generation of RBCs in many disorders. Specifically, ineffective nuclear expulsion (enucleation) during terminal maturation is an obstacle to therapeutic RBC production in vitro. To obtain mechanistic insights into terminal erythropoiesis we focused on FOXO3, a transcription factor implicated in erythroid disorders. Using an integrated computational and experimental systems biology approach, we show that FOXO3 is essential for the correct temporal gene expression during terminal erythropoiesis. We demonstrate that the FOXO3-dependent genetic network has critical physiological functions at key steps of terminal erythropoiesis including enucleation and mitochondrial clearance processes. FOXO3 loss deregulated transcription of genes implicated in cell polarity, nucleosome assembly and DNA packaging-related processes and compromised erythroid enucleation. Using high-resolution confocal microscopy and imaging flow cytometry we show that cell polarization is impaired leading to multilobulated Foxo3-/- erythroblasts defective in nuclear expulsion. Ectopic FOXO3 expression rescued Foxo3-/- erythroblast enucleation-related gene transcription, enucleation defects and terminal maturation. Remarkably, FOXO3 ectopic expression increased wild type erythroblast maturation and enucleation suggesting that enhancing FOXO3 activity may improve RBCs production. Altogether these studies uncover FOXO3 as a novel regulator of erythroblast enucleation and terminal maturation suggesting FOXO3 modulation might be therapeutic in disorders with defective erythroid maturation. Red blood cells (RBCs) are highly specialized cells that transport oxygen throughout the body and are essential for survival. However, RBCs have a limited lifespan and need to be replenished continuously by stem cells in the bone marrow. Mammalian RBCs are unique in that in order to fully mature they exclude their nucleus and other organelles. Mechanisms involved in these processes are not well understood at the molecular level. Defects in any of the these processes may lead to red blood cell defects, a decreased capacity to transport oxygen and/or a block in red blood cell production in vitro. Therefore, understanding how these processes are regulated at the molecular level can lead to promising new therapies for red blood cell defects and improved methods of generating red blood cells in a dish. Here, using an integrated computational and experimental biology approach, we found that the nuclear factor FOXO3 is a crucial regulator of red blood cell production by coordinating the expression of many of the genes specific for terminal maturation of red blood cells. Furthermore we found that FOXO3 can even increase the production of normal red blood cells in culture raising the possibility that enhancing FOXO3 may have a therapeutic use. Our studies identify FOXO3 as a novel regulator of RBC enucleation and terminal erythropoiesis.
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Toda S, Nishi C, Yanagihashi Y, Segawa K, Nagata S. Clearance of Apoptotic Cells and Pyrenocytes. Curr Top Dev Biol 2015; 114:267-95. [PMID: 26431571 DOI: 10.1016/bs.ctdb.2015.07.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Apoptotic cells are engulfed and digested by macrophages to maintain homeostasis in animals. If dead cells are not engulfed swiftly, they undergo secondary necrosis and release intracellular components that activate the immune system. Apoptotic cells are efficiently cleared due to phosphatidylserine (PtdSer) exposed on the cell surface that acts as an "eat me" signal. PtdSer is exposed through the activation of phospholipid scramblase and the inactivation of phospholipid flippase, which are both caspase-mediated events. Macrophages express a variety of molecules to recognize PtdSer, and use a sophisticated mechanism to engulf apoptotic cells. In red blood cells, the nucleus is lost when it is extruded as a pyrenocyte during definitive erythropoiesis. These pyrenocytes (nuclei surrounded by plasma membrane) also expose PtdSer on their surface and are efficiently engulfed by macrophages in a PtdSer-dependent manner. Macrophages transfer the engulfed apoptotic cell or pyrenocyte into lysosomes, where the components of the dead cell or pyrenocyte are degraded. If lysosomes cannot digest the DNA from apoptotic cells or pyrenocytes, the undigested DNA accumulates in the lysosome and activates macrophages to produce type I interferon (IFN) via a STING-dependent pathway; in embryos, this causes severe anemia. Here, we discuss how macrophages clear apoptotic cells and pyrenocytes.
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Affiliation(s)
- Satoshi Toda
- Laboratory of Biochemistry and Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Chihiro Nishi
- Laboratory of Biochemistry and Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Yuichi Yanagihashi
- Laboratory of Biochemistry and Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Katsumori Segawa
- Laboratory of Biochemistry and Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shigekazu Nagata
- Laboratory of Biochemistry and Immunology, Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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Simamura E, Arikawa T, Ikeda T, Shimada H, Shoji H, Masuta H, Nakajima Y, Otani H, Yonekura H, Hatta T. Melanocortins contribute to sequential differentiation and enucleation of human erythroblasts via melanocortin receptors 1, 2 and 5. PLoS One 2015; 10:e0123232. [PMID: 25860801 PMCID: PMC4393082 DOI: 10.1371/journal.pone.0123232] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/17/2015] [Indexed: 11/30/2022] Open
Abstract
In this study, we showed that adrenocorticotropic hormone (ACTH) promoted erythroblast differentiation and increased the enucleation ratio of erythroblasts. Because ACTH was contained in hematopoietic medium as contamination, the ratio decreased by the addition of anti-ACTH antibody (Ab). Addition of neutralizing Abs (nAbs) for melanocortin receptors (MCRs) caused erythroblast accumulation at specific stages, i.e., the addition of anti-MC2R nAb led to erythroblast accumulation at the basophilic stage (baso-E), the addition of anti-MC1R nAb caused accumulation at the polychromatic stage (poly-E), and the addition of anti-MC5R nAb caused accumulation at the orthochromatic stage (ortho-E). During erythroblast differentiation, ERK, STAT5, and AKT were consecutively phosphorylated by erythropoietin (EPO). ERK, STAT5, and AKT phosphorylation was inhibited by blocking MC2R, MC1R, and MC5R, respectively. Finally, the phosphorylation of myosin light chain 2, which is essential for the formation of contractile actomyosin rings, was inhibited by anti-MC5R nAb. Taken together, our study suggests that MC2R and MC1R signals are consecutively required for the regulation of EPO signal transduction in erythroblast differentiation, and that MC5R signal transduction is required to induce enucleation. Thus, melanocortin induces proliferation and differentiation at baso-E, and polarization and formation of an actomyosin contractile ring at ortho-E are required for enucleation.
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MESH Headings
- Adrenocorticotropic Hormone/antagonists & inhibitors
- Adrenocorticotropic Hormone/metabolism
- Antibodies, Neutralizing
- Cell Differentiation/physiology
- Cells, Cultured
- Erythroblasts/cytology
- Erythroblasts/metabolism
- Erythropoiesis/physiology
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Humans
- Melanocortins/metabolism
- Models, Biological
- Proto-Oncogene Proteins c-akt/metabolism
- Receptor, Melanocortin, Type 1/antagonists & inhibitors
- Receptor, Melanocortin, Type 1/genetics
- Receptor, Melanocortin, Type 1/metabolism
- Receptor, Melanocortin, Type 2/antagonists & inhibitors
- Receptor, Melanocortin, Type 2/genetics
- Receptor, Melanocortin, Type 2/metabolism
- Receptors, Melanocortin/antagonists & inhibitors
- Receptors, Melanocortin/genetics
- Receptors, Melanocortin/metabolism
- STAT5 Transcription Factor/metabolism
- Signal Transduction
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Affiliation(s)
- Eriko Simamura
- Department of Anatomy, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Tomohiro Arikawa
- Department of Biology, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Takayuki Ikeda
- Department of Biochemistry, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Hiroki Shimada
- Department of Anatomy, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Hiroki Shoji
- Department of Biology, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Hiroko Masuta
- Department of Anatomy, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Yuriko Nakajima
- Department of Anatomy, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Hiroki Otani
- Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo 693–8601, Japan
| | - Hideto Yonekura
- Department of Biochemistry, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
| | - Toshihisa Hatta
- Department of Anatomy, Kanazawa Medical University School of Medicine, Uchinada, Ishikawa 920–0293, Japan
- * E-mail:
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Satchwell TJ, Bell AJ, Toye AM. The sorting of blood group active proteins during enucleation. ISBT SCIENCE SERIES 2015; 10:163-168. [PMID: 26640516 PMCID: PMC4668593 DOI: 10.1111/voxs.12127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Enucleation represents the critical stage during red blood cell development when the nucleus is extruded from an orthochromatic erythroblast in order to generate a nascent immature reticulocyte. Extrusion of the nucleus results in loss of a proportion of the erythroblast plasma membrane, which surrounds the nucleus, the bulk of the endoplasmic reticulum and a small region of cytoplasm. For this reason enucleation provides an important point in erythroblast differentiation at which proteins not required for the function of the erythrocyte can be lost, whilst those that are important for the structure-function properties of the mature erythrocyte must be efficiently retained in the reticulocyte plasma membrane. Disturbances in protein distribution during enucleation are envisaged to occur during human diseases such as Hereditary Spherocytosis. This article will discuss the current knowledge of erythroblast enucleation in the context of retention and loss of proteins that display antigenic blood group sites and that exist within multiprotein complexes within the erythrocyte membrane.
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Affiliation(s)
- Timothy J. Satchwell
- School of Biochemistry, Medical Sciences Building, University Walk, Bristol BS8 1TD
- Bristol Institute of Transfusion Sciences, NHS Blood and Transplant, Filton, Bristol
| | - Amanda J. Bell
- School of Biochemistry, Medical Sciences Building, University Walk, Bristol BS8 1TD
| | - Ashley M. Toye
- School of Biochemistry, Medical Sciences Building, University Walk, Bristol BS8 1TD
- Bristol Institute of Transfusion Sciences, NHS Blood and Transplant, Filton, Bristol
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KLF1-null neonates display hydrops fetalis and a deranged erythroid transcriptome. Blood 2015; 125:2405-17. [PMID: 25724378 DOI: 10.1182/blood-2014-08-590968] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 02/21/2015] [Indexed: 12/14/2022] Open
Abstract
We describe a case of severe neonatal anemia with kernicterus caused by compound heterozygosity for null mutations in KLF1, each inherited from asymptomatic parents. One of the mutations is novel. This is the first described case of a KLF1-null human. The phenotype of severe nonspherocytic hemolytic anemia, jaundice, hepatosplenomegaly, and marked erythroblastosis is more severe than that present in congenital dyserythropoietic anemia type IV as a result of dominant mutations in the second zinc-finger of KLF1. There was a very high level of HbF expression into childhood (>70%), consistent with a key role for KLF1 in human hemoglobin switching. We performed RNA-seq on circulating erythroblasts and found that human KLF1 acts like mouse Klf1 to coordinate expression of many genes required to build a red cell including those encoding globins, cytoskeletal components, AHSP, heme synthesis enzymes, cell-cycle regulators, and blood group antigens. We identify novel KLF1 target genes including KIF23 and KIF11 which are required for proper cytokinesis. We also identify new roles for KLF1 in autophagy, global transcriptional control, and RNA splicing. We suggest loss of KLF1 should be considered in otherwise unexplained cases of severe neonatal NSHA or hydrops fetalis.
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Ji P. New Insights into the Mechanisms of Mammalian Erythroid Chromatin Condensation and Enucleation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 316:159-82. [DOI: 10.1016/bs.ircmb.2015.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Thom CS, Traxler EA, Khandros E, Nickas JM, Zhou OY, Lazarus JE, Silva APG, Prabhu D, Yao Y, Aribeana C, Fuchs SY, Mackay JP, Holzbaur ELF, Weiss MJ. Trim58 degrades Dynein and regulates terminal erythropoiesis. Dev Cell 2014; 30:688-700. [PMID: 25241935 DOI: 10.1016/j.devcel.2014.07.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 04/24/2014] [Accepted: 07/28/2014] [Indexed: 01/23/2023]
Abstract
TRIM58 is an E3 ubiquitin ligase superfamily member implicated by genome-wide association studies to regulate human erythrocyte traits. Here, we show that Trim58 expression is induced during late erythropoiesis and that its depletion by small hairpin RNAs (shRNAs) inhibits the maturation of late-stage nucleated erythroblasts to anucleate reticulocytes. Imaging flow cytometry studies demonstrate that Trim58 regulates polarization and/or extrusion of erythroblast nuclei. In vitro, Trim58 directly binds and ubiquitinates the intermediate chain of the microtubule motor dynein. In cells, Trim58 stimulates proteasome-dependent degradation of the dynein holoprotein complex. During erythropoiesis, Trim58 expression, dynein loss, and enucleation occur concomitantly, and all are inhibited by Trim58 shRNAs. Dynein regulates nuclear positioning and microtubule organization, both of which undergo dramatic changes during erythroblast enucleation. Thus, we propose that Trim58 promotes this process by eliminating dynein. Our findings identify an erythroid-specific regulator of enucleation and elucidate a previously unrecognized mechanism for controlling dynein activity.
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Affiliation(s)
- Christopher S Thom
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elizabeth A Traxler
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Eugene Khandros
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jenna M Nickas
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Olivia Y Zhou
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Jacob E Lazarus
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ana P G Silva
- School of Molecular Bioscience, The University of Sydney, Sydney NSW 2006, Australia
| | - Dolly Prabhu
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yu Yao
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chiaka Aribeana
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Serge Y Fuchs
- Department of Animal Biology and Mari Lowe Comparative Oncology Center, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joel P Mackay
- School of Molecular Bioscience, The University of Sydney, Sydney NSW 2006, Australia
| | - Erika L F Holzbaur
- Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell J Weiss
- Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
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Abstract
In this issue of Blood, Toda et al present a shift in the paradigm of erythroid enucleation and provide novel tools to further study and optimize terminal erythroid maturation in vitro.
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Cheng AW, Shi J, Wong P, Luo KL, Trepman P, Wang ET, Choi H, Burge CB, Lodish HF. Muscleblind-like 1 (Mbnl1) regulates pre-mRNA alternative splicing during terminal erythropoiesis. Blood 2014; 124:598-610. [PMID: 24869935 PMCID: PMC4110662 DOI: 10.1182/blood-2013-12-542209] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 05/16/2014] [Indexed: 12/18/2022] Open
Abstract
The scope and roles of regulated isoform gene expression during erythroid terminal development are poorly understood. We identified hundreds of differentiation-associated isoform changes during terminal erythropoiesis. Sequences surrounding cassette exons of skipped exon events are enriched for motifs bound by the Muscleblind-like (MBNL) family of splicing factors. Knockdown of Mbnl1 in cultured murine fetal liver erythroid progenitors resulted in a strong block in erythroid differentiation and disrupted the developmentally regulated exon skipping of Ndel1 mRNA, which is bound by MBNL1 and critical for erythroid terminal proliferation. These findings reveal an unanticipated scope of the alternative splicing program and the importance of Mbnl1 during erythroid terminal differentiation.
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Affiliation(s)
- Albert W Cheng
- Whitehead Institute for Biomedical Research, Cambridge, MA; Computational and Systems Biology Program, and
| | - Jiahai Shi
- Whitehead Institute for Biomedical Research, Cambridge, MA
| | - Piu Wong
- Whitehead Institute for Biomedical Research, Cambridge, MA
| | - Katherine L Luo
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and
| | - Paula Trepman
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and
| | - Eric T Wang
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA
| | - Heejo Choi
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and
| | - Christopher B Burge
- Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and
| | - Harvey F Lodish
- Whitehead Institute for Biomedical Research, Cambridge, MA; Departments of Biology and Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA; and
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35
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MerTK-mediated engulfment of pyrenocytes by central macrophages in erythroblastic islands. Blood 2014; 123:3963-71. [DOI: 10.1182/blood-2014-01-547976] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Key Points
An in vitro system for the engulfment of pyrenocytes was established using erythroblastic islands. MerTK, a receptor kinase, was essential for the engulfment of pyrenocytes by the central macrophages at erythroblastic islands.
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36
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Sui Z, Nowak RB, Bacconi A, Kim NE, Liu H, Li J, Wickrema A, An XL, Fowler VM. Tropomodulin3-null mice are embryonic lethal with anemia due to impaired erythroid terminal differentiation in the fetal liver. Blood 2014; 123:758-67. [PMID: 24159174 PMCID: PMC3907761 DOI: 10.1182/blood-2013-03-492710] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 10/11/2013] [Indexed: 11/20/2022] Open
Abstract
Tropomodulin (Tmod) is a protein that binds and caps the pointed ends of actin filaments in erythroid and nonerythoid cell types. Targeted deletion of mouse tropomodulin3 (Tmod3) leads to embryonic lethality at E14.5-E18.5, with anemia due to defects in definitive erythropoiesis in the fetal liver. Erythroid burst-forming unit and colony-forming unit numbers are greatly reduced, indicating defects in progenitor populations. Flow cytometry of fetal liver erythroblasts shows that late-stage populations are also decreased, including reduced percentages of enucleated cells. Annexin V staining indicates increased apoptosis of Tmod3(-/-) erythroblasts, and cell-cycle analysis reveals that there are more Ter119(hi) cells in S-phase in Tmod3(-/-) embryos. Notably, enucleating Tmod3(-/-) erythroblasts are still in the process of proliferation, suggesting impaired cell-cycle exit during terminal differentiation. Tmod3(-/-) late erythroblasts often exhibit multilobular nuclear morphologies and aberrant F-actin assembly during enucleation. Furthermore, native erythroblastic island formation was impaired in Tmod3(-/-) fetal livers, with Tmod3 required in both erythroblasts and macrophages. In conclusion, disruption of Tmod3 leads to impaired definitive erythropoiesis due to reduced progenitors, impaired erythroblastic island formation, and defective erythroblast cell-cycle progression and enucleation. Tmod3-mediated actin remodeling may be required for erythroblast-macrophage adhesion, coordination of cell cycle with differentiation, and F-actin assembly and remodeling during erythroblast enucleation.
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Affiliation(s)
- Zhenhua Sui
- The Scripps Research Institute, La Jolla, CA
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37
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Abstract
Red blood cells (RBCs), which constitute the most abundant cell type in the body, come in two distinct flavors- primitive and definitive. Definitive RBCs in mammals circulate as smaller, anucleate cells during fetal and postnatal life, while primitive RBCs circulate transiently in the early embryo as large, nucleated cells before ultimately enucleating. Both cell types are formed from lineage-committed progenitors that generate a series of morphologically identifiable precursors that enucleate to form mature RBCs. While definitive erythroid precursors mature extravascularly in the fetal liver and postnatal marrow in association with macrophage cells, primitive erythroid precursors mature as a semi-synchronous cohort in the embryonic bloodstream. While the cytoskeletal network is critical for the maintenance of cell shape and the deformability of definitive RBCs, little is known about the components and function of the cytoskeleton in primitive erythroblasts. Erythropoietin (EPO) is a critical regulator of late-stage definitive, but not primitive, erythroid progenitor survival. However, recent studies indicate that EPO regulates multiple aspects of terminal maturation of primitive murine and human erythroid precursors, including cell survival, proliferation, and the rate of terminal maturation. Primitive and definitive erythropoiesis share central transcriptional regulators, including Gata1 and Klf1, but are also characterized by the differential expression and function of other regulators, including myb, Sox6, and Bcl11A. Flow cytometry-based methodologies, developed to purify murine and human stage-specific erythroid precursors, have enabled comparative global gene expression studies and are providing new insights into the biology of erythroid maturation.
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Affiliation(s)
- James Palis
- Department of Pediatrics, Center for Pediatric Biomedical Research, University of Rochester Medical CenterRochester, NY, USA
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38
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Watanabe S, De Zan T, Ishizaki T, Yasuda S, Kamijo H, Yamada D, Aoki T, Kiyonari H, Kaneko H, Shimizu R, Yamamoto M, Goshima G, Narumiya S. Loss of a Rho-Regulated Actin Nucleator, mDia2, Impairs Cytokinesis during Mouse Fetal Erythropoiesis. Cell Rep 2013; 5:926-32. [DOI: 10.1016/j.celrep.2013.10.021] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 08/29/2013] [Accepted: 10/11/2013] [Indexed: 01/17/2023] Open
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39
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Abstract
Asymmetric cell division (ACD), a mechanism for cell-type diversification in both prokaryotes and eukaryotes, is accomplished through highly coordinated cell-fate segregation, genome partitioning, and cell division. Whereas important paradigms have arisen from the study of animal embryonic divisions, the strategies for choreographing the dynamic subprocesses are, in fact, highly varied. This review examines divergent mechanisms of ACD across different kingdoms. Examples discussed show that there is no obligatory hierarchy among the dynamic events and that asymmetry can emerge from each event, but cell polarization more often occurs as the initial instructive process for patterning ACD especially in the multicellular context.
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Affiliation(s)
- Rong Li
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
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40
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Bell AJ, Satchwell TJ, Heesom KJ, Hawley BR, Kupzig S, Hazell M, Mushens R, Herman A, Toye AM. Protein distribution during human erythroblast enucleation in vitro. PLoS One 2013; 8:e60300. [PMID: 23565219 PMCID: PMC3614867 DOI: 10.1371/journal.pone.0060300] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 02/25/2013] [Indexed: 11/24/2022] Open
Abstract
Enucleation is the step in erythroid terminal differentiation when the nucleus is expelled from developing erythroblasts creating reticulocytes and free nuclei surrounded by plasma membrane. We have studied protein sorting during human erythroblast enucleation using fluorescence activated cell sorting (FACS) to obtain pure populations of reticulocytes and nuclei produced by in vitro culture. Nano LC mass spectrometry was first used to determine the protein distribution profile obtained from the purified reticulocyte and extruded nuclei populations. In general cytoskeletal proteins and erythroid membrane proteins were preferentially restricted to the reticulocyte alongside key endocytic machinery and cytosolic proteins. The bulk of nuclear and ER proteins were lost with the nucleus. In contrast to the localization reported in mice, several key erythroid membrane proteins were detected in the membrane surrounding extruded nuclei, including band 3 and GPC. This distribution of key erythroid membrane and cytoskeletal proteins was confirmed using western blotting. Protein partitioning during enucleation was investigated by confocal microscopy with partitioning of cytoskeletal and membrane proteins to the reticulocyte observed to occur at a late stage of this process when the nucleus is under greatest constriction and almost completely extruded. Importantly, band 3 and CD44 were shown not to restrict specifically to the reticulocyte plasma membrane. This highlights enucleation as a stage at which excess erythroid membrane proteins are discarded in human erythroblast differentiation. Given the striking restriction of cytoskeleton proteins and the fact that membrane proteins located in macromolecular membrane complexes (e.g. GPA, Rh and RhAG) are segregated to the reticulocyte, we propose that the membrane proteins lost with the nucleus represent an excess mobile population of either individual proteins or protein complexes.
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Affiliation(s)
- Amanda J. Bell
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | | | - Kate J. Heesom
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Bethan R. Hawley
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Sabine Kupzig
- Bristol Institute of Transfusion Science, NHS Blood and Transplant, Bristol, United Kingdom
| | - Matthew Hazell
- Bristol Institute of Transfusion Science, NHS Blood and Transplant, Bristol, United Kingdom
| | - Rosey Mushens
- Bristol Institute of Transfusion Science, NHS Blood and Transplant, Bristol, United Kingdom
| | - Andrew Herman
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Ashley M. Toye
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
- Bristol Institute of Transfusion Science, NHS Blood and Transplant, Bristol, United Kingdom
- * E-mail:
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