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Liu W, Varier KM, Sample KM, Zacksenhaus E, Gajendran B, Ben-David Y. Erythropoietin Signaling in the Microenvironment of Tumors and Healthy Tissues. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1223:17-30. [PMID: 32030683 DOI: 10.1007/978-3-030-35582-1_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Erythropoietin (EPO), the primary cytokine of erythropoiesis, stimulates both proliferation and differentiation of erythroid progenitors and their maturation to red blood cells. Basal EPO levels maintain the optimum levels of circulating red blood cells. However, during hypoxia, EPO secretion and its expression is elevated drastically in renal interstitial fibroblasts, thereby increasing the number of erythroid progenitors and accelerating their differentiation to mature erythrocytes. A tight regulation of this pathway is therefore of paramount importance. The biological response to EPO is commenced through the involvement of its cognate receptor, EPOR. The receptor-ligand complex results in homodimerization and conformational changes, which trigger downstream signaling events and cause activation or inactivation of critical transcription factors that promote erythroid expansion. In recent years, recombinant human EPO (rEPO) has been widely used as a therapeutic tool to treat a number of anemias induced by infection, and chemotherapy for various cancers. However, several studies have uncovered a tumor promoting ability of EPO in man, which likely occurs through EPOR or alternative receptor(s). On the other hand, some studies have demonstrated a strong anticancer activity of EPO, although the mechanism still remains unclear. A thorough investigation of EPOR signaling could yield enhanced understanding of the pathobiology for a variety of disorders, as well as the potential novel therapeutic strategies. In this chapter, in addition to the clinical relevance of EPO/EPOR signaling, we review its anticancer efficacy within various tumor microenvironments.
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Affiliation(s)
- Wuling Liu
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, Guizhou, China.,The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, China
| | - Krishnapriya M Varier
- Department of Medical Biochemistry, Dr. A.L.M. Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, India
| | - Klarke M Sample
- Central Laboratory, Guizhou Provincial People's Hospital, The Affiliated Hospital of Guizhou University, Guiyang, Guizhou, China
| | - Eldad Zacksenhaus
- Department of Medicine, University of Toronto, Toronto, ON, Canada.,Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, ON, Canada
| | - Babu Gajendran
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, Guizhou, China. .,The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, China.
| | - Yaacov Ben-David
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, Guizhou, China. .,The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, China.
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Significance of Erythropoietin Receptor Antagonist EMP9 in Cancers. VITAMINS AND HORMONES 2017. [PMID: 28629523 DOI: 10.1016/bs.vh.2017.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
We have clarified that cancer cells express their own erythropoietin (Epo) and its receptor (EpoR) mRNA levels, and the respective proteins, which are under the control of Epo-EpoR signaling. Then we explored to inhibit the Epo-EpoR signaling with an EpoR antagonist Epo mimetic peptide 9 (EMP9) that is a derivative of an Epo-mimicking peptide EMP1. In the study of the cancer cell lines in vitro, rhEpo accelerated the cancer cell growth, whereas the EMP9 inhibited the cell growth along with the inhibition of STAT5 tyrosine phosphorylation. Moreover, in vitro study of surgically resected histoculture of lung cancers revealed that EMP9 diminishes the expression of myoglobin in the cancer cells and destroys the feeding vessels. Additionally, in the xenografts of lung cancer histoculture, the EMP9 destroyed the xenografts by inducing apoptosis and suppressing proliferation of cancer cells in concomitant with macrophage accumulation. Furthermore, two types of perforations were detected in their cytoplasm: the one is mediated by nNOS in the cancer cells and the other one is by iNOS in the innate immune cells. These findings suggest that the inhibition of the Epo-EpoR signaling by EMP9 induces the cancer cell death that is mediated by the apoptosis and calcification of the cancer cells as well as the oxygen deficiency through the feeding vessels. Taken together, EMP9-based therapy may be a promising strategy to treat cancer patients.
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Yasuda Y, Fujita M, Koike E, Obata K, Shiota M, Kotani Y, Musha T, Tsuji-Kawahara S, Satou T, Masuda S, Okano J, Yamasaki H, Okumoto K, Uesugi T, Nakao S, Hoshiai H, Mandai M. Erythropoietin Receptor Antagonist Suppressed Ectopic Hemoglobin Synthesis in Xenografts of HeLa Cells to Promote Their Destruction. PLoS One 2015; 10:e0122458. [PMID: 25874769 PMCID: PMC4398449 DOI: 10.1371/journal.pone.0122458] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/11/2015] [Indexed: 02/02/2023] Open
Abstract
The aim of this study is to explore a cause-oriented therapy for patients with uterine cervical cancer that expresses erythropoietin (Epo) and its receptor (EpoR). Epo, by binding to EpoR, stimulates the proliferation and differentiation of erythroid progenitor cells into hemoglobin-containing red blood cells. In this study, we report that the HeLa cells in the xenografts expressed ε, γ, and α globins as well as myoglobin (Mb) to produce tetrameric α2ε2 and α2γ2 and monomeric Mb, most of which were significantly suppressed with an EpoR antagonist EMP9. Western blotting revealed that the EMP9 treatment inhibited the AKT-pAKT, MAPKs-pMAPKs, and STAT5-pSTAT5 signaling pathways. Moreover, the treatment induced apoptosis and suppression of the growth and inhibited the survival through disruption of the harmonized hemoprotein syntheses in the tumor cells concomitant with destruction of vascular nets in the xenografts. Furthermore, macrophages and natural killer (NK) cells with intense HIF-1α expression recruited significantly more in the degenerating foci of the xenografts. These findings were associated with the enhanced expressions of nNOS in the tumor cells and iNOS in macrophages and NK cells in the tumor sites. The treated tumor cells exhibited a substantial number of perforations on the cell surface, which indicates that the tumors were damaged by both the nNOS-induced nitric oxide (NO) production in the tumor cells as well as the iNOS-induced NO production in the innate immune cells. Taken together, these data suggest that HeLa cells constitutively acquire ε, γ and Mb synthetic capacity for their survival. Therefore, EMP9 treatment might be a cause-oriented and effective therapy for patients with squamous cell carcinoma of the uterine cervix.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Blotting, Western
- Cell Proliferation/drug effects
- Erythropoietin/chemistry
- Erythropoietin/pharmacology
- Gene Expression/drug effects
- HeLa Cells
- Hemoglobins/biosynthesis
- Hemoglobins/genetics
- Heterografts/drug effects
- Heterografts/metabolism
- Humans
- Male
- Mice, Inbred BALB C
- Mice, Nude
- Mitogen-Activated Protein Kinases/metabolism
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Neoplasms, Experimental/pathology
- Peptides/chemical synthesis
- Peptides/pharmacology
- Proto-Oncogene Proteins c-akt/metabolism
- Receptors, Erythropoietin/antagonists & inhibitors
- Receptors, Erythropoietin/genetics
- Receptors, Erythropoietin/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- STAT5 Transcription Factor/metabolism
- Signal Transduction/drug effects
- Transplantation, Heterologous
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Affiliation(s)
- Yoshiko Yasuda
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Mitsugu Fujita
- Departments of Microbiology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Eiji Koike
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Koshiro Obata
- Department of Obstetrics and Gynecology, Nara Hospital Kinki University Faculty of Medicine, Ikoma, Nara, Japan
| | - Mitsuru Shiota
- Department of Gynecological Oncology, Kawasaki Medical University, Kurashiki, Okayama, Japan
| | - Yasushi Kotani
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Terunaga Musha
- Department of Gynecology, Medicalcourt Hachinohe West Hospital, Hachinohe, Aomori, Japan
| | - Sachiyo Tsuji-Kawahara
- Departments of Immunology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Takao Satou
- Departments of Pathology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Seiji Masuda
- Laboratory of Molecular Biology of Bioresponse, Graduate School of Biostudies, Kyoto University, Kyoto, 606–8502, Japan
| | - Junko Okano
- Division of Anatomy and Cell Biology, Shiga University of Medical Science, Otsu, Shiga, Japan
| | - Harufumi Yamasaki
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Katsumi Okumoto
- Lifescience Institute, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Tadao Uesugi
- Departments of Pathology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Shinichi Nakao
- Departments of Anesthesiology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Hiroshi Hoshiai
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
| | - Masaki Mandai
- Departments of Obstetrics and Gynecology, Kinki University Faculty of Medicine, Osakasayama, Osaka, Japan
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Shiota M, Yasuda Y, Shimaoka M, Tsuritani M, Koike E, Oiki M, Matsubara J, Taketani S, Murakami H, Yamasaki H, Okumoto K, Hoshiai H. Erythropoietin is involved in hemoprotein syntheses in developing human decidua. Congenit Anom (Kyoto) 2013; 53:18-26. [PMID: 23480354 DOI: 10.1111/j.1741-4520.2012.00382.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 08/04/2012] [Indexed: 10/28/2022]
Abstract
Before establishment of feto-placental circulation, decidua can synthesize hemoproteins to maintain oxygen homeostasis in situ. Using the human decidua of induced abortions ranging from 5 to 8 weeks of gestation, we determined the expression levels of erythropoietin, erythropoietin receptor, cytoglobin, myoglobin, embryonic-, fetal- and adult hemoglobin mRNA by quantitative RT-PCR analysis and identified their proteins by Western blot and immunohistochemical analyses. Erythropoietin signaling was demonstrated in phosphatidylinositol-3-kinase/protein kinase B pathway by Western blot, and the transcriptional factors for erythroid and non-erythroid heme synthesis were examined by RT-PCR analysis. In decidua, erythropoietin and its receptor mRNAs, erythropoietin receptor protein and phosphatidylinositol-3-kinase, were expressed with a peak at 6 weeks of gestation. Moreover, the decidua during 5 to 8 weeks of gestation expressed embryonic, fetal and adult hemoglobins additionally cytoglobin and myoglobin at transcriptional and protein levels. The heme portion of these hemoproteins is considered to be synthesized by non-erythroid δ-aminolevulinate synthase. These hemoproteins were discernible especially in decidual cells concomitant with cytotrophoblast cells and macrophage in these developing decidua. Considering the different capacity for oxygen binding and dissociation among hemoglobins with the oxygen storage capacity for cytoglobin and myoglobin, these hemoproteins appear to play a role in oxygen demand in decidua in situ before development of feto-placental circulation under the control of erythropoietin signaling.
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Affiliation(s)
- Mitsuru Shiota
- Department of Obstetrics and Gynecology, Kinki University School of Medicine, Osaka, Japan
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Erythropoietin promotes survival and regeneration of insect neurons in vivo and in vitro. Neuroscience 2011; 188:95-108. [DOI: 10.1016/j.neuroscience.2011.05.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 05/06/2011] [Accepted: 05/07/2011] [Indexed: 12/11/2022]
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Erythropoietin-responsive sites in normal and malignant human lung tissues. Anat Sci Int 2010; 85:204-13. [PMID: 20397063 DOI: 10.1007/s12565-010-0081-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Accepted: 03/22/2010] [Indexed: 10/19/2022]
Abstract
Preliminary findings of various types of globin expressed in the respiratory bronchiolar and alveolar epithelium prompted us to compare the expression of erythropoietin (Epo) and its receptor (EpoR) in normal (healthy) human lung tissues with that in malignant lung tissues. The expression of Epo and EpoR was examined at the transcriptional and protein levels in normal and malignant lung tissues by reverse transcription-PCR, western blot, and immunohistochemical analyses. EpoR mRNA, but not Epo mRNA, was detected in all samples. In normal tissues, EpoR was detected in the mesothelium, chondrocytes, alveolar cells, vascular endothelial cells, smooth muscle fibers, macrophages, and neutrophils, while in malignant foci, the cancer cells of five malignant types showed various intensities of EpoR immunoreactivity. The pattern of staining of EpoR protein was generally stronger in the malignant tissues than in the normal samples. Phosphorylation of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK-ERK1/2) was frequently seen in malignant cells, but not in the normal tissues, with the exception of macrophages. Based on the expression of Epo and EpoR mRNA with the EpoR in almost all cell components in normal tissues, we suggest that the normal lung may produce various types of globin through the autocrine and/or paracrine role of Epo. When the Epo signal is upregulated by hypoxic stress, the normal cells appear to transform into malignant cells and proliferate through activated MAPK signaling.
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Developmental profile of erythropoietin and its receptor in guinea-pig retina. Cell Tissue Res 2009; 336:21-9. [DOI: 10.1007/s00441-009-0754-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 01/02/2009] [Indexed: 10/21/2022]
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Yasuda Y, Sasaki T, Takagawa M, Maeda M, Yasuda M, Atsumi T, Fujita Y, Fujita H. Erythropoietin contributes to implantation: ectopic hemoglobin synthesis in decidual cells of mice. Congenit Anom (Kyoto) 2007; 47:22-33. [PMID: 17300687 DOI: 10.1111/j.1741-4520.2006.00137.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Erythropoietin, by binding to its receptor, stimulates definitive erythroblasts to accumulate hemoglobin (Hb) by up-regulating erythroid-specific genes and causes differentiation of erythroblasts into erythrocytes. In mouse decidua we have found the expression of transcripts for the erythropoietin receptor, the function of which has not yet been elucidated. Erythropoietin signaling was inhibited by the injection of a soluble form of the erythropoietin receptor capable of binding with erythropoietin into the mouse uterine cavity on day 4 of gestation, and pale and defective decidual bodies appeared three days later. These pale decidual bodies contained defective embryos without extension to the ectoplacental region, while normal reddish decidual bodies contained normal developing embryos and expressed embryonic and adult Hb with characteristic location of the respective hemoglobins in which an epsilon- or beta-globin signal was confirmed. Furthermore, blocking of erythropoietin signaling destroyed Hb-containing cells and resulted in apoptosis that caused embryonic death. Thus, erythropoietin-mediated Hb synthesis is essential for the survival of decidual cells. In addition, although no transcripts for GATA-1 and erythroid heme enzymes could be detected, genes for beta-globin, as well as non-specific delta-aminolevulinate synthase, were expressed and regulated in an erythropoietin-dependent manner. This is the first evidence that ectopic Hb synthesis exists and that erythropoietin coregulates erythroid (globin) and nonerythroid (delta-aminolevulinate synthase) genes.
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Affiliation(s)
- Yoshiko Yasuda
- Department of Anatomy Division 1, Kinki University School of Medicine, Osakasayama, Osaka, Japan.
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9
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Lippi G, Franchini M, Salvagno GL, Guidi GC. Biochemistry, physiology, and complications of blood doping: facts and speculation. Crit Rev Clin Lab Sci 2006; 43:349-91. [PMID: 16769597 DOI: 10.1080/10408360600755313] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Competition is a natural part of human nature. Techniques and substances employed to enhance athletic performance and to achieve unfair success in sport have a long history, and there has been little knowledge or acceptance of potential harmful effects. Among doping practices, blood doping has become an integral part of endurance sport disciplines over the past decade. The definition of blood doping includes methods or substances administered for non-medical reasons to healthy athletes for improving aerobic performance. It includes all means aimed at producing an increased or more efficient mechanism of oxygen transport and delivery to peripheral tissues and muscles. The aim of this review is to discuss the biochemistry, physiology, and complications of blood doping and to provide an update on current antidoping policies.
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Affiliation(s)
- Giuseppe Lippi
- Dipartimento di Scienze Morfologico-Biomediche, Istituto di Chimica e Microscopia Clinica, Università Degli Studi di Verona, Verona, Italy
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Abstract
The biologic effects of erythropoietin in the central and peripheral nervous system involve the activation of its specific cell surface receptor and corresponding signal transduction pathways. This article reviews the neuroprotective effects of erythropoietin in brain, emphasizing the progress made using in vitro and in vivo research models.
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Affiliation(s)
- Sandra Juul
- Division of Neonatology, Department of Pediatrics, University of Washington, PO Box 356320, Seattle, WA 98195, USA.
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Yasuda Y, Matsuo T, Nagao M. Blockade of erythropoietin signal at the early postimplantation period inhibits the development of decidua and embryo in mice. Congenit Anom (Kyoto) 2004; 44:9-17. [PMID: 15008895 DOI: 10.1111/j.1741-4520.2003.00003.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We have previously shown that erythropoietin and erythropoietin receptor mRNAs are expressed in mouse embryos and in decidua at the early postimplantation stage, and that erythropoietin receptor mRNA is expressed in advance of erythropoietin mRNA. We subsequently studied the role of exogenous erythropoietin in early development until the embryo proper can express erythropoietin by itself. In the present study, to block the erythropoietin signal in the decidual body where the early postimplantation embryo develops with decidua, we injected an antierythropoietin antibody or soluble erythropoietin receptor into decidual bodies through the uterine wall at day 6 of gestation. For controls, we injected saline or denatured soluble erythropoietin receptor. After 3 or 4 days, we examined the experimental and control decidual bodies. Macroscopic examinations revealed that experimental groups showed anemic small decidua in 50-60% of the decidual bodies of which 18-25% contained developmental-arrested embryos with brain anomalies. Immunohistochemical examination revealed that positive erythropoietin receptor immunoreactivity was detected in the sinusoidal linings of the decidua capsularis and the neuroepithelial cells of the embryos in the controls, while in the experimental groups, these erythropoietin receptor-positive cells were destroyed leading to few erythrocytes in the decidua, and lacy neuroepithelium of the embryos due to apoptosis. In conclusion, erythropoietin from maternal blood appears to be required for sinusoids to retain maternal blood, and for neurogenesis in embryos during a short period of mouse development.
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Affiliation(s)
- Yoshiko Yasuda
- Department of Anatomy, Division 1, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan.
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Al-Huniti NH, Widness JA, Schmidt RL, Veng-Pedersen P. Pharmacokinetic/Pharmacodynamic Analysis of Paradoxal Regulation of Erythropoietin Production in Acute Anemia. J Pharmacol Exp Ther 2004; 310:202-8. [PMID: 14988424 DOI: 10.1124/jpet.104.066027] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The regulatory mechanism responsible for a paradoxal, rapid drop in the erythropoietin (EPO) plasma level seen 2 to 4 days after acute, phlebotomy-induced anemia was investigated in seven adult sheep. To introduce acute anemia, each sheep underwent two phlebotomies where the hemoglobin (Hb) was reduced to 3 or 4 g/dl over 4 to 5 h. The phlebotomies were spaced 4 to 6 weeks apart in three animals, and 8 days apart in four other animals. EPO plasma levels, reticulocyte count, Hb, and p50 for oxygen-Hb dissociation were determined from frequent blood samplings throughout the study period. EPO's disposition pharmacokinetic (PK) and plasma clearance were determined from i.v. bolus injections of tracer amounts of a recombinant human EPO tracer. The controlled drop in Hb resulted in a rapid increase in plasma EPO to 836 +/- 52 mU/ml (mean +/- coefficient of variation percentage) that was followed by a paradoxical rapid drop 2 to 4 days after the phlebotomy while the animals were still very anemic (Hb = 4.3 +/- 15 g/dl). The rapid drop in plasma EPO level could not be explained by the up-regulated clearance (clearance increased by a factor of less than 2.5) or by physiological adaptation (no change in p50, p > 0.05, second phlebotomy to Hb = 3g/dl inadequately stimulated the EPO production). The PK/pharmacodynamic (PD) analysis supports the hypothesis of a limited sustained high EPO production rate in acute anemia, which indicates an apparent deficiency in the regulation of EPO production in acute anemia. The hypothesis was supported by a PK/PD feedback inhibition model that showed good agreement with the data (r = 0.973 +/- 1.57).
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Affiliation(s)
- N H Al-Huniti
- Division of Pharmaceutics, The College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA
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Al-Huniti NH, Widness JA, Schmidt RL, Veng-Pedersen P. Erythropoietin production rate in phlebotomy-induced acute anemia. Biopharm Drug Dispos 2004; 25:389-97. [PMID: 15529399 DOI: 10.1002/bdd.424] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVE To estimate the rate of erythropoietin (EPO) production under physiological, conditions and to examine the regulatory mechanism of EPO production in response to acute phlebotomy-induced anemia. METHODS Six sheep each underwent two phlebotomies in which the hemoglobin (Hb) was reduced to 3-4 g/dl over 4-5 h. The EPO plasma level, reticulocytes, Hb and EPO clearance were followed by frequent blood sampling. The EPO production rate was determined by a semi-parametric method based on a disposition decomposition analysis that accounts for the nonlinear disposition kinetics of EPO and corrects for time-dependent changes in the clearance. RESULTS The controlled drop in hemoglobin resulted in an abrupt increase in the plasma EPO concentration (peak level 812+/-40 mU/ml, mean+/-CV%) that was followed by a rapid drop 2-4 days after the phlebotomy at a time when the sheep were still anemic (Hb=4.3+/-16 g/dl). The EPO production rate at baseline was 43+/-52 U/day/kg and the amounts of EPO produced over an 8 day period resulting from the first and second phlebotomy were 2927+/-40 U/kg and 3012+/-31 U/kg, respectively. CONCLUSIONS The rapid reduction in the EPO plasma level observed 2-4 days following the phlebotomy cannot be explained solely by the increase in EPO clearance but also by a reduction in EPO production.
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Affiliation(s)
- N H Al-Huniti
- College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA
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Abstract
Many cancer patients suffer from anemia, which has a major detrimental effect on their quality of life. Recombinant human erythropoietin (rHuEPO) is now widely used in cancer patients, as it improves hematocrit, lowers blood transfusion requirements, and improves quality of life. Recent research indicates that EPO has pleiotropic effects on the body well beyond the maintenance of red cell mass, but the mechanisms involved in relieving fatigue and improving quality of life in cancer patients are poorly understood. EPO receptors (EPO-Rs) have been detected in many different cells and tissues, providing evidence for autocrine, paracrine, and endocrine functions of EPO. Apart from its endocrine function, EPO may have a generalized role as an antiapoptotic agent that is associated with enhancement of muscle tone, mucosal status, and gonadal and cognitive function. The recent discovery of EPO-Rs in breast tumor vasculature, while raising important questions about the possible effects of pharmacological doses of rHuEPO on tumor cells, also suggests that the receptors could provide a useful target for drugs attached to EPO.
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Affiliation(s)
- Terence R Lappin
- Haematology, Cancer Research Centre, Belfast City Hospital, Queen's University, Belfast, Northern Ireland.
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Juul S. Erythropoietin in the central nervous system, and its use to prevent hypoxic-ischemic brain damage. ACTA PAEDIATRICA (OSLO, NORWAY : 1992). SUPPLEMENT 2003; 91:36-42. [PMID: 12477263 DOI: 10.1111/j.1651-2227.2002.tb02904.x] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
UNLABELLED A new field of clinical and scientific interest has recently developed based on the discovery that the hematopoietic cytokine erythropoietin (Epo) has important non-hematopoietic functions in the brain and other organs, particularly during development. The biological effects of Epo in the central nervous system (CNS) involve activation of its specific receptor and corresponding signal transduction pathways. Epo receptor expression is abundant in the developing mammalian brain, and decreases as term approaches. Epo has been identified as a neurotrophic and neuroprotective agent in a wide variety of experimental paradigms, from neuronal cell culture to in vivo models of brain injury. Several mechanisms by which Epo produces neuroprotection are recognized. Epo (i) decreases glutamate toxicity, (ii) induces the generation of neuronal anti-apoptotic factors, (iii) reduces inflammation, (iv) decreases nitric oxide-mediated injury, and (v) has direct antioxidant effects. CONCLUSION Collectively, the evidence suggests that Epo may provide a new approach to the treatment of a variety of CNS disorders in adults and children, especially as a possible therapy for perinatal asphyxia. This review summarizes the current knowledge on the neurotrophic and neuroprotective functions of Epo in the developing and injured brain.
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Affiliation(s)
- S Juul
- Department of Pediatrics, Division of Neonatology, University of Washington, Seattle, Washington 98195, USA.
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Niimi G, Usuda N, Shinzato M, Nagamura Y. A light and electron microscopic study of the mouse visceral yolk sac endodermal cells in the middle and late embryonic periods, showing the possibility of definitive erythropoiesis. Ann Anat 2002; 184:425-9. [PMID: 12392322 DOI: 10.1016/s0940-9602(02)80073-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hematological studies have revealed the importance of the visceral yolk sac (VYS) in the primitive erythropoiesis of mouse embryos at an early stage before day 12. We examined the possibility of the occurrence of extra-embryonic erythropoiesis at a stage later than embryonic day 12 by light and electron microscopic analyses. Surprisingly, a novel structure in the form of erythrocyte-like globules was observed in the VYS endodermal cells. They were consistently present in the VYS endodermal cells from embryonic day 12 until day 18 (birth is day 19), by immunocytochemical and enzyme histochemical analyses. They were immuno-positive for mouse erythrocyte antibody and also positive for the benzidine reaction showing the presence of hemoglobin. The erythrocyte-like globules were shown to be the erythrocytes present in the cytoplasm. These results indicated that erythropoiesis in the VYS endodermal cells continues from the early embryonic stage, as primitive erythropoiesis, until the late stage.
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Affiliation(s)
- Gen Niimi
- Institute for Comprehensive Medical Science, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan.
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Abstract
Human milk contains substantial concentrations of erythropoietin, a hormone best known for its role in the regulation of erythropoiesis. Recent studies show that erythropoietin receptors are widely distributed in human tissues, including the gastrointestinal tract, endothelial cells, spinal cord, and brain, suggesting that erythropoietin plays a wider role in infant development. Mammary epithelial cells contribute to the production of erythropoietin in human milk, and erythropoietin concentrations appear to rise slowly in human milk during the first few months of lactation. Current data suggest that erythropoietin in human milk may play a pleiomorphic role in erythropoiesis, neurodevelopment, maturation of the gut, apoptosis, and immunity in the infant.
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Yasuda Y, Okano M, Nagao M, Masuda S, Fujita Y, Sasaki R. Erythropoietin and erythropoietin-receptor producing cells demonstrated by in situ hybridization in mouse visceral yolk sacs. Anat Sci Int 2002; 77:58-63. [PMID: 12418085 DOI: 10.1046/j.0022-7722.2002.00007.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have previously demonstrated that mRNAs for erythropoietin and the erythropoietin receptor temporarily express on the visceral yolk sacs on days 9-11 of gestation in mice. In order to investigate the sites of expression, we performed in situ hybridization on visceral yolk sacs. Visceral yolk sacs from 10-day-old mice embryos were frozen in liquid nitrogen, and processed for cryosections. Sections were hybridized with a 35S-labeled RNA probe complementary to mRNA coding for erythropoietin or erythropoietin receptor. Erythropoietin mRNA was detectable in 57.6% of the endodermal epithelial cells, while erythropoietin-receptor mRNA was discerned in 90.8% of the endodermal cells and mesodermal cells, including hemocyteblasts. Moreover, erythropoietin protein was detectable in 52.8% of the endodermal epithelial cells, and on the surface of hemocyteblasts and mesothelial cells. Erythropoietin-receptor protein was discernible in 87.2% of the endodermal cells and in the corresponding mesodermal cells to those where erythropoietin protein was expressed by immunohistochemical examinations. The results indicate that erythropoietin-synthesizing cells are located in half of the endodermal epithelial cells, while the majority of cells in the visceral yolk sac are erythropoietin-receptor-producing cells, indicating that almost all cell population in the visceral yolk sac is erythropoietin-responding cells via both autocrine and paracrine routes.
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Affiliation(s)
- Yoshiko Yasuda
- Department of Anatomy, Division 1, Kinki University School of Medicine, Osaka-Sayama, Osaka 589-8511, Japan.
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19
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David RB, Lim GB, Moritz KM, Koukoulas I, Wintour EM. Quantitation of the mRNA levels of Epo and EpoR in various tissues in the ovine fetus. Mol Cell Endocrinol 2002; 188:207-18. [PMID: 11911958 DOI: 10.1016/s0303-7207(01)00718-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A partial cDNA of the sheep erythropoietin receptor (EpoR) was obtained and used in real-time PCR to quantitate mRNA levels in placenta, liver and kidney throughout development (term=150 days). This was compared with Epo mRNA levels in the same tissues. Both Epo and EpoR mRNA were present in the placenta throughout gestation at low levels from 66 days onwards and these did not vary throughout gestation. Compared with the expression levels in the placenta, the levels of EpoR gene expression in the liver at 66, 99 and 140 days were, median (range)-288 (120-343), 278 (63-541) and 7 (3-15), respectively, reflecting the disappearance of erythropoiesis after 130 days. Low levels of EpoR gene expression were seen in the kidney at 3 (2-5), 5 (2-7), and 7 (2-10) times that in the placenta at 66, 99, and 140 days, respectively. By hybridization histochemistry the EpoR mRNA was located in the proximal tubular cells of the mesonephros and metanephros at 42 days. Epo mRNA levels in the kidney were 215 (116-867), 528 (113-765) and 46 (15-204) times those in the placenta at 69, 99, and 140 days, respectively. In the liver at the same ages the concentrations of mRNA were lower than in the kidney, the liver/placenta ratios being 50 (11-90), 17 (3-39), 9 (5-14). At 130 days Epo/EpoR levels in the hippocampus were 6+/-3 and 8+/-3 times that in the term placenta, respectively. These studies demonstrate that the ovine placenta expresses the Epo gene from at least 66 days of gestation. However, gene expression levels are very low compared with those in the liver and kidney, and even the hippocampus.
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Affiliation(s)
- R Bruce David
- Norwegian School of Veterinary Science, Oslo, Norway
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20
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Yu X, Shacka JJ, Eells JB, Suarez-Quian C, Przygodzki RM, Beleslin-Cokic B, Lin CS, Nikodem VM, Hempstead B, Flanders KC, Costantini F, Noguchi CT. Erythropoietin receptor signalling is required for normal brain development. Development 2002; 129:505-16. [PMID: 11807041 DOI: 10.1242/dev.129.2.505] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Erythropoietin, known for its role in erythroid differentiation, has been shown to be neuroprotective during brain ischaemia in adult animal models. Although high levels of erythropoietin receptor are produced in embryonic brain, the role of erythropoietin during brain development is uncertain. We now provide evidence that erythropoietin acts to stimulate neural progenitor cells and to prevent apoptosis in the embryonic brain. Mice lacking the erythropoietin receptor exhibit severe anaemia and defective cardiac development, and die at embryonic day 13.5 (E13.5). By E12.5, in addition to apoptosis in foetal liver, endocardium and myocardium, the erythropoietin receptor null mouse shows extensive apoptosis in foetal brain. Lack of erythropoietin receptor affects brain development as early as E10.5, resulting in a reduction in the number of neural progenitor cells and increased apoptosis. Corresponding in vitro cultures of cortical cells from Epor–/– mice also exhibited decreases in neuron generation compared with normal controls and increased sensitivity to low oxygen tension with no surviving neurons in Epor–/– cortical cultures after 24 hour exposure to hypoxia. The viability of primary Epor+/+ rodent embryonic cortical neurons was further increased by erythropoietin stimulation. Exposure of these cultures to hypoxia induced erythropoietin expression and a tenfold increase in erythropoietin receptor expression, increased cell survival and decreased apoptosis. Cultures of neuronal progenitor cells also exhibited a proliferative response to erythropoietin stimulation. These data demonstrate that the neuroprotective activity of erythropoietin is observed as early as E10.5 in the developing brain, and that induction of erythropoietin and its receptor by hypoxia may contribute to selective cell survival in the brain.
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Affiliation(s)
- Xiaobing Yu
- Laboratory of Chemical Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
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21
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Juul SE, Ledbetter DJ, Joyce AE, Dame C, Christensen RD, Zhao Y, DeMarco V. Erythropoietin acts as a trophic factor in neonatal rat intestine. Gut 2001; 49:182-9. [PMID: 11454792 PMCID: PMC1728399 DOI: 10.1136/gut.49.2.182] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Erythropoietin (Epo) receptors are present on enterocytes of fetal and neonatal small bowel but the role of Epo in the bowel is not known. AIMS We tested the following hypotheses: (1) enterally dosed Epo is absorbed from the intestines of neonatal rats, (2) Epo acts as a trophic factor in developing small bowel, and (3) the trophic effects of Epo are dependent on the route of administration. METHODS The dose dependent effects of enterally dosed recombinant human erythropoietin (rEpo 0--1000 U/kg/day) were studied in artificially raised rat pups and compared with dam raised controls and dam raised pups given rEpo in rat milk. After one week, reticulocyte counts, haematocrits, and plasma Epo concentrations were measured, and calibrated morphometric measurements of villi were performed. The effects of route of rEpo administration (enteral v parenteral) on erythropoiesis, bowel growth, and disaccharidase activity were studied in nursing pups treated for one and two weeks. RESULTS Serum Epo concentrations ranged from undetectable (<0.6 mU/ml) to 8.4 mU/ml in control and enterally dosed pups (median 1.8 mU/ml), and from 4.9 to 82.3 mU/ml (median 20.4 mU/ml) in parenterally dosed animals. No increase in haematocrit or reticulocyte count was noted in enterally treated pups compared with controls after up to two weeks of treatment. Small bowel length was greater in rEpo treated pups, and a dose dependent increase in villus surface area which was independent of the route of dosing and associated with increased BrdU uptake was found. CONCLUSIONS rEpo is not enterally absorbed in an intact and functional form from the intestines of neonatal rat pups. Thus enterally dosed rEpo has no erythropoietic effects. However, rEpo acts as a trophic factor in developing rat small bowel whether given enterally or parenterally.
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Affiliation(s)
- S E Juul
- Department of Pediatrics, University of Florida College of Medicine, Florida, USA
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22
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Dame C, Bartmann P, Wolber E, Fahnenstich H, Hofmann D, Fandrey J. Erythropoietin gene expression in different areas of the developing human central nervous system. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2000; 125:69-74. [PMID: 11154762 DOI: 10.1016/s0165-3806(00)00118-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
UNLABELLED Evidence from cell culture and animal experiments suggests a neuroprotective and neurotrophic function of erythropoietin (EPO). We have quantitated the distribution of EPO mRNA expression in the developing human central nervous system (CNS). PATIENTS AND METHODS Up to seven biopsies from different areas of the CNS of four preterm fetuses (gestational age 23-37 weeks) were obtained at routine postmortem examinations. EPO mRNA was quantitated by competitive PCR in samples from the CNS, the kidneys, and the liver where the EPO gene is predominantly expressed at this gestational age. RESULTS EPO mRNA was most abundant in one sample from the cerebellum (0.29 amol/microg total RNA [amol=10(-18)mol]) and two from the pituitary gland (0.23 amol/microg total RNA), but levels varied considerably. EPO mRNA in the cortex cerebri (median 0.12 amol/microg total RNA; n=4) dominated over the expression in the corpora amygdala (median 0.05 amol/microg total RNA; n=4), the hippocampus (median 0.03 amol/microg total RNA; n=4), or the basal ganglia (median 0.01 amol/microg total RNA; n=3). Only little EPO mRNA (<0.01 and 0.06 amol/microg total RNA) was found in the spinal cord. EPO mRNA levels in the cerebellum, pituitary gland, or the cerebral cortex were within the same range as in the liver (0.03-1.67 amol/microg total RNA; n=4), or the kidneys (0.06-0.79 amol/microg total RNA; n=4). CONCLUSION We found the EPO gene expressed throughout the fetal human CNS. Our data provide the basis to discuss a function for EPO in the brain of humans as well.
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Affiliation(s)
- C Dame
- Department of Neonatology, University Children's Hospital, Bonn, Germany
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Chin K, Yu X, Beleslin-Cokic B, Liu C, Shen K, Mohrenweiser HW, Noguchi CT. Production and processing of erythropoietin receptor transcripts in brain. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 81:29-42. [PMID: 11000476 DOI: 10.1016/s0169-328x(00)00157-1] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The expression of erythropoietin receptor (EpoR) in brain and neuronal cells, and hypoxia-responsive production of erythropoietin (Epo) in the brain suggests that the function of Epo as a survival or viability factor may extend beyond hematopoietic tissue and erythroid progenitor cells. Epo, produced by astrocytes and neurons, can be induced by hypoxia by severalfold, and in animal models Epo administration is neuroprotective to ischemic challenge. We characterized the human EpoR transcript in brain and neuronal cells to determine its contribution in regulating the Epo response in brain. Screening of a human brain cDNA library and quantitative analysis of EpoR transcripts indicate that the EpoR gene locus is transcriptionally active in brain. In addition to the proximal promoter that is active in hematopoietic cells, a significant proportion of transcripts originates far upstream from the EpoR coding region. Unlike erythroid cells with efficient splicing of EpoR transcripts to its mature form, brain EpoR transcripts are inefficiently or alternately processed with a bias towards the 3' coding region. In human EpoR transgenic mice, anemic stress induces expression of the transgene and endogenous EpoR gene in hematopoietic tissue and brain. In culture of neuronal cells, hypoxia induces EpoR expression and increases sensitivity to Epo. Induction of EpoR expression appears to be a consequence of increased transcription from the upstream region and proximal promoter, and a shift towards increased processing efficiency. These data suggest that in contrast to erythropoiesis where erythroid progenitor cells express high levels of EpoR and are directly responsive to Epo stimulation, the neuroprotective effect of Epo and its receptor may require two molecular events: the induction of Epo production by hypoxia and an increase in EpoR expression in neuronal cells resulting in increased sensitivity to Epo.
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Affiliation(s)
- K Chin
- Laboratory of Chemical Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892-1822, USA
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24
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Abstract
Epo was once regarded as a cytokine with only hematopoietic effects. It is now clear that the distributions of Epo and Epo-R are more widespread in the developing human. Epo-R is widely distributed during early fetal development, leading to speculation that Epo acts in concert with other growth factors to optimize growth and development. Areas in which Epo has important recognized effects are on endothelial cells, and in the developing heart, gastrointestinal tract, and brain. It may also be important in the regulation of vascular growth during the menstrual cycle, and in the stimulation of testosterone production in men. Epo and Epo-R are prominent in the brain during fetal development, leading to speculation that they play an important role in neurodevelopment. There are also promising data regarding rEpo as a possible neuroprotective agent in such conditions as hypoxia, because it decreases programmed cell death induced during such adverse conditions. It is unlikely, however, that rEpo crosses the blood-brain barrier in normal premature infants, and it is not clear whether the CNS effects of rEpo, should it cross the blood-brain barrier, are harmful or beneficial in the setting of a developing brain.
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Affiliation(s)
- S E Juul
- Division of Neonatology, University of Florida College of Medicine, Gainesville, USA.
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25
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Affiliation(s)
- S E Juul
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, USA
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26
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Fairchild Benyo D, Conrad KP. Expression of the erythropoietin receptor by trophoblast cellsin the human placenta. Biol Reprod 1999; 60:861-70. [PMID: 10084959 DOI: 10.1095/biolreprod60.4.861] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Nonclassical sites of erythropoietin (EPO) and erythropoietin receptor (EPO-R) expression have been described that suggest new physiological roles for this hormone unrelated to erythropoiesis. The recent finding of EPO expression by trophoblast cells in the human placenta prompted us to consider whether these cells also express EPO-R. With use of immunocytochemistry, EPO-R was identified in villous and extravillous cytotrophoblast cells, as well as in the syncytiotrophoblast at all gestational ages. EPO-R was also expressed by cells within the villous core, including endothelial cells of fetoplacental blood vessels. Placental tissues and isolated and immunopurified trophoblast cells, as well as trophoblast-derived choriocarcinoma Jar cells, expressed immunoreactive EPO-R on Western blot. EPO-R mRNA was also detected in the same placental tissues and trophoblast cells by nested-primer reverse transcription-polymerase chain reaction. Finally, EPO-R was functional insofar as the receptor was phosphorylated on tyrosine residues in response to exogenous EPO treatment of cultured trophoblast or Jar cells. Thus, the present findings support the hypothesis that trophoblast cells of the human placenta express EPO-R. In view of these results, taken together with previous work demonstrating EPO expression by the same cells, an autocrine role for this hormone in the survival, proliferation, or differentiation of placental trophoblast cells is proposed.
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Affiliation(s)
- D Fairchild Benyo
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pennsylvania 15213, USA
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27
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Juul SE, Yachnis AT, Christensen RD. Tissue distribution of erythropoietin and erythropoietin receptor in the developing human fetus. Early Hum Dev 1998; 52:235-49. [PMID: 9808074 DOI: 10.1016/s0378-3782(98)00030-9] [Citation(s) in RCA: 241] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Erythropoietin receptors (Epo-R) have been demonstrated on several nonhematopoietic cell types in animal models and in cell culture. Our objective was to determine the tissue distribution and cellular specificity of erythropoietin (Epo) and its receptor in the developing human fetus. STUDY DESIGN The expression of Epo and Epo-R mRNA was ascertained by RT-PCR for organs ranging in maturity from 5 to 24 weeks postconception. The cellular location of protein immunoreactivity was then determined using specific antiEpo and antiEpo-R antibodies. Antibody specificity was established by Western analysis. RESULTS mRNA for Epo and Epo-R was found in all organs in the first two trimesters. Immunolocalization of Epo was limited to the liver parenchymal cells, kidney interstitial cells and proximal tubules, neural retina of the eye, and adrenal cortex. As development progressed, immunoreactivity in the kidney became more prominent. In contrast, immunoreactivity for Epo-R was widespread throughout the body, in cell types including endothelial cells, myocardiocytes, macrophages, retinal cells, cells of the adrenal cortex and medulla, as well as in small bowel, spleen, liver, kidney, and lung. CONCLUSIONS The distribution of Epo and its receptor is more widespread in the developing human than was initially postulated. Epo-R is expressed on many cell types during early fetal development, leading us to speculate that Epo acts in concert with somatic growth and development factors during this period. Further investigation is required to understand the nonhematopoietic role of Epo during human development.
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Affiliation(s)
- S E Juul
- Department of Pediatrics, University of Florida College of Medicine, JHMHC, Gainesville 32610-0296, USA
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Yasuda Y, Masuda S, Chikuma M, Inoue K, Nagao M, Sasaki R. Estrogen-dependent production of erythropoietin in uterus and its implication in uterine angiogenesis. J Biol Chem 1998; 273:25381-7. [PMID: 9738005 DOI: 10.1074/jbc.273.39.25381] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Although erythropoietin (Epo) has been shown to possess in vitro angiogenic activity, its physiological significance has not been demonstrated. Normally angiogenesis does not occur actively in adults but an exception is the female reproductive organ. In the uterine endometrium, angiogenesis takes place actively for supporting the endometrial growth that occurs during transition from the diestrus to estrous stage. This transition is under control of 17beta-estradiol (E2), an ovarian hormone, and can be mimicked by injection of E2 to ovariectomized (OVX) mouse. Thus, the uterus is a pertinent site to examine the Epo function in angiogenesis. We found that Epo protein and its mRNA were produced in an E2-dependent manner, when the uterus from OVX mouse was cultured in vitro. The de novo protein synthesis was not needed for E2 induction of Epo mRNA. Administration of E2 to OVX mouse induced a rapid and transient increase in Epo mRNA in the uterus. Injection of Epo into the OVX mouse uterine cavity promoted blood vessel formation in the endometrium. Furthermore, injection of the soluble Epo receptor capable of binding with Epo into the uterine cavity of non-OVX mouse in diestrus stage inhibited the endometrial transition to proestrus stage, whereas heat-inactivated soluble Epo receptor allowed the transition to occur. These results, combined with our finding that the endothelial cells in uterine endometrium express Epo receptor, strongly suggest that Epo is an important factor for the E2-dependent cyclical angiogenesis in uterus.
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Affiliation(s)
- Y Yasuda
- Department of Anatomy, Kinki University School of Medicine, Osaka 589-0014, Japan
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29
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Juul SE, Anderson DK, Li Y, Christensen RD. Erythropoietin and erythropoietin receptor in the developing human central nervous system. Pediatr Res 1998; 43:40-9. [PMID: 9432111 DOI: 10.1203/00006450-199801000-00007] [Citation(s) in RCA: 281] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have previously shown the presence of erythropoietin (Epo) within the spinal fluid of normal preterm and term infants, and the presence of Epo receptor (Epo-R) in the spinal cords of human fetuses. It is not known, however: 1) whether cells within the fetal central nervous system (CNS) express Epo; 2) if so, whether this expression changes with development; 3) which cells within the CNS express Epo-R; 4) whether Epo-R expression within the CNS changes with development; and 5) whether Epo-R within the fetal CNS are functional. Expression of mRNA for Epo and Epo-R was sought by reverse transcription-PCR in mixed primary cultures of fetal spinal cords as well as NT2 and hNT cells, human cell lines of neuronal precursors and mature neurons, respectively. Epo was measured by ELISA in spent media from primary cell culture, and immunohistochemistry was used to identify Epo-R on neurons and glia in cell culture, and in brain sections. Developmental changes in Epo and Epo-R expression were sought in spinal cords and brains from fetuses of 7-24 wk postconception by semiquantitative PCR. To assess Epo-R function, NT2 cells were exposed to conditions which stimulate programmed cell death, and rescue from apoptosis by the addition of recombinant Epo was evaluated by nuclear matrix protein ELISA, cell counts, and by Klenow labeling of DNA fragments. Epo and Epo-R mRNA were expressed in mixed primary cultures of neural tissues and NT2 and hNT cells. Epo was detected by ELISA in media removed from mixed cell cultures, and immunohistochemical staining confirmed the presence of Epo-R on neurons and their supporting cells. Semiquantitative PCR revealed no significant change in expression of either Epo or Epo-R in spinal cords between 7 and 16 wk of gestation, with increased expression of Epo and Epo-R in brains from 8 to 24 wk of gestation. Epo mRNA expression from neurons doubled under conditions of hypoxia. Recombinant Epo decreased apoptotic cell death of neurons under conditions of hypoxia. Protein and mRNA for Epo and its receptor are expressed by human neurons and glial cells in spinal cord and brain during fetal development. These receptors appear to have a neuroprotective effect in conditions of hypoxia.
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Affiliation(s)
- S E Juul
- Department of Pediatrics, University of Florida College of Medicine, Gainesville 32610-0296, USA
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30
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Liu C, Shen K, Liu Z, Noguchi CT. Regulated human erythropoietin receptor expression in mouse brain. J Biol Chem 1997; 272:32395-400. [PMID: 9405448 DOI: 10.1074/jbc.272.51.32395] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Erythropoietin (Epo) is known for its role in erythropoiesis and acts by binding to its receptor (EpoR) on the surface of erythroid progenitors. EpoR activity follows the site of hematopoiesis from the embryonic yolk sac to the fetal liver and then the adult spleen and bone marrow. Expression of EpoR has also been observed in selected cells of non-hematopoietic origin, such as the embryonic mouse brain during mid-gestation, at levels comparable to adult bone marrow. EpoR transcripts in brain decrease during development falling by birth to less than 1-3% of the level in hematopoietic tissue. We have now recapitulated this pattern of expression using a human EpoR transgene consisting of an 80-kb human EpoR genomic fragment. The highest level of expression was observed in the embryonic yolk sac and fetal liver, analogous to the endogenous gene, in addition to expression in adult spleen and bone marrow. Although activity of this transgene in brain is initially lower than the endogenous gene, it does exhibit the down-regulation observed for the endogenous gene in adult brain. The expression pattern of hybrid transgenes of an hEpoR promoter fused to beta-galactosidase in 9. 5-day embryos suggested that the hEpoR promoter region between -1778 and -150 bp 5' of the transcription start site is necessary to direct EpoR expression in the neural tube. EpoR expression in the neural tube may be the origin of the EpoR transcripts detected in brain during development. These data demonstrate that both the mouse and human EpoR genes contain regulatory elements to direct significant levels of expression in a developmentally controlled manner in brain and suggest that in addition to its function during erythropoiesis, EpoR may play a role in the development of selected non-hematopoietic tissue.
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Affiliation(s)
- C Liu
- Laboratory of Chemical Biology, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-1822, USA
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31
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Moritz KM, Lim GB, Wintour EM. Developmental regulation of erythropoietin and erythropoiesis. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:R1829-44. [PMID: 9435635 DOI: 10.1152/ajpregu.1997.273.6.r1829] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It is well established that erythropoiesis occurs first in the yolk sac, then in the liver, subsequently moving to the bone marrow and, in rodents, the spleen during development. The origin of the erythropoietic precursors and some factors suggested to be important for the changing location of erythropoiesis are discussed in this review. Until recently, the major site of erythropoietin (Epo) production in the fetus was thought to be the liver, but studies have shown now that the Epo gene is expressed strongly in the fetal kidney, even in the temporary mesonephros. The metanephric Epo mRNA is upregulated by anemia, downregulated by glucocorticoids, and contributes substantially to circulating hormone levels in hemorrhaged ovine fetuses. Other sites of Epo and Epo receptor production, likely to have important actions during development, are the placenta and the brain.
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Affiliation(s)
- K M Moritz
- Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia
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32
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Abstract
Erythropoietin (Epo) was measured by enzyme-linked immunosorbent assay in 80 cerebrospinal fluid (CSF) samples to determine whether Epo is present in the CSF of infants, CSF Epo concentrations correlate with age, and CSF Epo concentrations correlate with Epo therapy. Epo was present in the CSF of normal neonates. CSF Epo concentrations correlated negatively with increasing age. Recombinant Epo therapy did not affect CSF Epo concentrations, although values ranged somewhat higher in this group.
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Affiliation(s)
- S E Juul
- Department of Pediatrics, University of Florida College of Medicine, Gainesville 32610-0296, USA
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33
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Maxwell PH, Ferguson DJ, Nicholls LG, Iredale JP, Pugh CW, Johnson MH, Ratcliffe PJ. Sites of erythropoietin production. Kidney Int 1997; 51:393-401. [PMID: 9027712 DOI: 10.1038/ki.1997.52] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- P H Maxwell
- Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, United Kingdom.
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Morishita E, Masuda S, Nagao M, Yasuda Y, Sasaki R. Erythropoietin receptor is expressed in rat hippocampal and cerebral cortical neurons, and erythropoietin prevents in vitro glutamate-induced neuronal death. Neuroscience 1997; 76:105-16. [PMID: 8971763 DOI: 10.1016/s0306-4522(96)00306-5] [Citation(s) in RCA: 522] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recently, erythropoietin has been shown to be produced by astrocytes and its production is hypoxia-inducible. In the present study, we demonstrated, using a reverse transcription-polymerase chain reaction assay and immunostaining of the cells, that the erythropoietin receptor was expressed in cultured hippocampal and cerebral cortical neurons of day 19 rat embryo. Erythropoietin protected the cultured neurons from glutamate neurotoxicity. Neurons cultured for seven to 10 days were exposed to glutamate for 15 min and after culture for a further 24 h in the absence of glutamate the neuron survival was assayed. Significant protection was observed with erythropoietin from 3 pM (c. 100 pg/ml) in a dose-dependent manner. The protection was completely reversed by co-application of a soluble erythropoietin receptor, an extracellular domain capable of binding with erythropoietin. For exhibition of the neuroprotective effect, exposure of neurons to erythropoietin approximately 8 h prior to exposure to glutamate was required. Experiments with the inhibitors indicated that RNA and protein syntheses were necessary for the protection. However, exposure to erythropoietin for a short period (5 min or less) was sufficient to elicit the protective effect. The protective effect of erythropoietin was blocked by the simultaneous addition of EGTA. These findings and the previous finding that erythropoietin induces a rapid and transient increase in intracellular Ca2+ concentration in neuronal cells suggest that erythropoietin plays a neuroprotective role in brain injury caused by hypoxia or ischemia and that erythropoietin-induced Ca2+ influx from outside of the cells is a critical initial event yielding an enhanced resistance of the neurons to glutamate toxicity.
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Affiliation(s)
- E Morishita
- Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan
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35
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Abstract
The understanding of the endocrine regulation of red cell production has been extended greatly since the erythropoietin gene was cloned and recombinant human erythropoietin has become available for experimental and clinical applications. Human erythropoietin is a 30 kDa glycoprotein. It is composed of 165 amino acids and 4 carbohydrate side chains. Studies in rodents have shown that blood-borne erythropoietin originates from peritubular cells, possibly fibroblasts, in the renal cortex and from parenchymal cells in the liver. In addition, erythropoietin mRNA has been demonstrated in spleen, lung and brain. Tissue hypoxia is the main stimulus for erythropoietin synthesis. Erythropoietin gene expression is controlled by DNA-binding proteins, primarily by hypoxia-inducible factor 1. Erythropoietin maintains red cell production by inhibiting apoptosis of erythrocytic progenitors, and by stimulating their proliferation and differentiation into normoblasts. The functional human erythropoietin receptor, a 484-amino acid glycoprotein, is member of the class I cytokine receptor superfamily. Lack of erythropoietin results in anaemia. Recombinant human erythropoietin is efficient for treatment of the anaemia of chronic renal failure. In addition, the drug is increasingly administrated to persons suffering from anaemia of chronic diseases and to surgical patients, thus abolishing the need for homologous red cell transfusion.
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Affiliation(s)
- W Jelkmann
- Institut für Physiologie, Medizinische Universität zu Lübeck
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36
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Yasuda Y, Okano M, Nagao M, Masuda S, Konishi H, Ueda K, Matsuo T, Tsujiguchi K, Tajima S, Sasaki R, Tanimura T. Erythropoietin in mouse avascular yolk sacs is increased by retinoic acid. Dev Dyn 1996; 207:184-94. [PMID: 8906421 DOI: 10.1002/(sici)1097-0177(199610)207:2<184::aid-aja6>3.0.co;2-d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Erythropoiesis begins first in the visceral yolk sac (VYS) of the embryo; however, the involvement of erythropoietin (EPO) in yolk-sac erythropoiesis has not been studied adequately. This study reports the expression of EPO in normal and hypoxic VYSs and alterations in yolk sac components induced by retinoic acid (RA) in mice. Gravid mice (plug day = day 0 of gestation) were given one oral dose of 60 mg/kg of RA in olive oil on days 6, 6.5, 7, 7.5, or 8 of gestation and were sacrificed 2.5, 3, or 3.5 days later. Control mice received olive oil without RA. None of the dams developed anemia, but more than 80% of the embryos of the dams that received RA on day 6, 6.5, or 7 of gestation had avascular yolk sacs (AVYs) and anemia. In these AVYs, the adenosine triphosphate (ATP) level was as low as 18-59% of that in the control VYSs. Reverse transcription-polymerase chain reaction and Southern analysis of products demonstrated that mRNA for EPO receptor (EPR) was expressed in both VYSs and AVYs on days 9-11 of gestation, and EPO mRNA was present in VYSs and AVYs on days 9 and 10 of gestation and in vehicle-exposed VYSs on day 11 of gestation. Furthermore, enzyme immunoassay of EPO indicated that AVYs contained more EPO protein than control VYSs. Light microscopy revealed that, in AVYs, in addition to the defective hemopoietic cells, the endodermal layer was exclusively altered: The presence of focal proliferated regions and the separation from the mesenchyme led to a single layer from which some immature cells seemed to be migrating. Immunolocalization of EPO showed its presence in all components of VYSs with a characteristic distribution pattern: In the endodermal layer, cells with positive EPO staining decreased as gestation advanced, and erythroid precursor cells showed positive staining. In AVYs, the proliferated endodermal cells had EPO in abundance; in the separated regions, the distinction between positive and negative EPO staining became clearer than that in the control VYSs, and the immature cells in the lumens also had EPO. EPR was seen on the cell surface of the corresponding cells that reacted to EPO. These findings suggest that VYSs not only produce EPO temporarily but also respond to the oxygen content in situ. EPO and EPR appear to be synthesized in the endodermal cells of the VYSs that are likely to respond to the circumstances induced by RA.
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Affiliation(s)
- Y Yasuda
- Department of Anatomy (First Division), Kinki University School of Medicine, Osaka, Japan
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Li Y, Juul SE, Morris-Wiman JA, Calhoun DA, Christensen RD. Erythropoietin receptors are expressed in the central nervous system of mid-trimester human fetuses. Pediatr Res 1996; 40:376-80. [PMID: 8865271 DOI: 10.1203/00006450-199609000-00002] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Recombinant erythropoietin (rEpo) is an effective treatment for infants with the anemia of prematurity. rEpo was previously thought to act only on erythroid progenitor cells, but evidence now indicates that certain nonerythroid cells also express functional erythropoietin receptors (Epo-R). Such receptors have been observed on cells in the developing murine brain and spinal cord. The objective of this study was to determine whether Epo-R are expressed in the CNS of mid-trimester human fetuses. For this study, spinal cords were collected from five mid-trimester abortuses. RNA was extracted from the washed specimens, and the presence of Epo-R mRNA was sought by reverse transcription followed by polymerase chain reaction. Immunohistochemistry was then used to determine the anatomic location of the cells expressing Epo-R within the fetal spinal cord. The results showed that all fetal spinal cords tested contained Epo-R mRNA. The cells expressing Epo-R were radiating from the ependymal canal toward the anterior and posterior median sulci. We conclude that Epo-R are expressed on cells in the developing human CNS. Further studies are needed to determine whether they are clinically relevant in the premature infant.
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Affiliation(s)
- Y Li
- Department of Pediatrics, University of Florida College of Medicine, Gainesville 32610-0296, USA
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Marti HH, Wenger RH, Rivas LA, Straumann U, Digicaylioglu M, Henn V, Yonekawa Y, Bauer C, Gassmann M. Erythropoietin gene expression in human, monkey and murine brain. Eur J Neurosci 1996; 8:666-76. [PMID: 9081618 DOI: 10.1111/j.1460-9568.1996.tb01252.x] [Citation(s) in RCA: 425] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The haematopoietic growth factor erythropoietin is the primary regulator of mammalian erythropoiesis and is produced by the kidney and the liver in an oxygen-dependent manner. We and others have recently demonstrated erythropoietin gene expression in the rodent brain. In this work, we show that cerebral erythropoietin gene expression is not restricted to rodents but occurs also in the primate brain. Erythropoietin mRNA was detected in biopsies from the human hippocampus, amygdala and temporal cortex and in various brain areas of the monkey Macaca mulatta. Exposure to a low level of oxygen led to elevated erythropoietin mRNA levels in the monkey brain, as did anaemia in the mouse brain. In addition, erythropoietin receptor mRNA was detected in all brain biopsies tested from man, monkey and mouse. Analysis of primary cerebral cells isolated from newborn mice revealed that astrocytes, but not microglia cells, expressed erythropoietin. When incubated at 1% oxygen, astrocytes showed >100-fold time-dependent erythropoietin mRNA accumulation, as measured with the quantitative reverse transcription-polymerase chain reaction. The specificity of hypoxic gene induction in these cells was confirmed by quantitative Northern blot analysis showing hypoxic up-regulation of mRNA encoding the vascular endothelial growth factor, but not of other genes. These findings demonstrate that erythropoietin and its receptor are expressed in the brain of primates as they are in rodents, and that, at least in mice, primary astrocytes are a source of cerebral erythropoietin expression which can be up-regulated by reduced oxygenation.
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Affiliation(s)
- H H Marti
- Institute of Physiology, Zurich University Medical School, Zurich, Switzerland
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39
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Nagao M, Masuda S, Ueda M, Sasaki R. Erythropoietin processing in erythropoietic system and central nervous system. Cytotechnology 1995; 18:83-91. [DOI: 10.1007/bf00744323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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40
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Okano M, Masuda S, Narita H, Masushige S, Kato S, Imagawa S, Sasaki R. Retinoic acid up-regulates erythropoietin production in hepatoma cells and in vitamin A-depleted rats. FEBS Lett 1994; 349:229-33. [PMID: 8050571 DOI: 10.1016/0014-5793(94)00673-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Retinoic acid (RA) stimulated the production of erythropoietin (Epo) in a human hepatoma cell line, HepG2 cells. The stimulation was due to the accumulation of Epo mRNA. The Epo production in HepG2 cells was also dependent on O2 tension for cell culture but the enhancement of Epo production by RA was independent of O2 tension, indicating that RA exerts its effect through a pathway different from O2. Oral administration of RA to the vitamin A-depleted rats elevated the concentration of Epo in serum. These results suggest that RA up-regulates EPO production in vivo as well as in vitro.
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Affiliation(s)
- M Okano
- Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan
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41
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A novel site of erythropoietin production. Oxygen-dependent production in cultured rat astrocytes. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)32195-6] [Citation(s) in RCA: 350] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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