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Erythropoietin-Mediated Regulation of Central Respiratory Command. VITAMINS AND HORMONES 2017. [PMID: 28629514 DOI: 10.1016/bs.vh.2017.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Erythropoietin (Epo) is a cytokine expressed throughout the body, including in the central nervous system where it can act as a breathing modulator in the central respiratory network. In vitro, Epo allows maintaining the activity of respiratory neurons during acute hypoxia, resulting in inhibition of the hypoxia-induced rhythm depression. In vivo, Epo action on the central respiratory command results in enhancement of the acute hypoxic ventilatory response, allowing a better oxygenation of the body by improvement of gases exchanges in the lungs. Importantly, this effect of Epo is age-dependent, being observed at adulthood and at both early and late postnatal ages, but not at middle postnatal ages, when an important setup of the central respiratory command occurs. Epo regulation of the central respiratory command involves at least two intracellular signaling pathways, PI3K-Akt and MEK-ERK pathways. However, the exact mechanism underlying the action of Epo on the central respiratory control remains to be deciphered, as well as the exact cell types and nuclei involved in this control. Epo-mediated effect on the central respiratory command is regulated by several factors, including hypoxia, sex hormones, and an endogen antagonist. Although more knowledge is needed before reaching the clinical trial step, Epo seems to be a promising therapeutic treatment, notably against newborn breathing disorders.
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Pathipati P, Ferriero DM. The Differential Effects of Erythropoietin Exposure to Oxidative Stress on Microglia and Astrocytes in vitro. Dev Neurosci 2017; 39:310-322. [PMID: 28511187 DOI: 10.1159/000467391] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 02/28/2017] [Indexed: 12/15/2022] Open
Abstract
The neonatal brain is especially susceptible to oxidative stress owing to its reduced antioxidant capacity. Following hypoxic-ischemic (HI) injury, for example, there is a prolonged elevation in levels of hydrogen peroxide (H2O2) in the immature brain compared to the adult brain, resulting in lasting injury that can lead to life-long disability or morbidity. Erythropoietin (Epo) is one of few multifaceted treatment options that have been promising enough to trial in the clinic for both term and preterm brain injury. Despite this, there is a lack of clear understanding of how Epo modulates glial cell activity following oxidative injury, specifically, whether it affects microglia (Mg) and astrocytes (Ast) differently. Using an in vitro approach using primary murine Mg and Ast subjected to H2O2 injury, we studied the oxidative and inflammatory responses of Mg and Ast to recombinant murine (rm)Epo treatment. We found that Epo protects Ast from H2O2 injury (p < 0.05) and increases secreted nitric oxide levels in these cells (p < 0.05) while suppressing intracellular reactive oxygen species (p < 0.05) and superoxide ion (p < 0.05) levels only in Mg. Using a multiplex analysis, we noted that although H2O2 induced the levels of several chemokines, rmEpo did not have any significant specific effects on their levels, either with or without the presence of conditioned medium from injured neurons (NCM). Ultimately, it appears that rmEpo has pleiotropic effects based on the cell type; it has a protective effect on Ast but an antioxidative effect only on Mg without any significant modulation of chemokine and cytokine levels in either cell type. These findings highlight the importance of considering all cell types when assessing the benefits and pitfalls of Epo use.
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Affiliation(s)
- Praneeti Pathipati
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
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Zhang Y, Rogers HM, Zhang X, Noguchi CT. Sex difference in mouse metabolic response to erythropoietin. FASEB J 2017; 31:2661-2673. [PMID: 28283542 DOI: 10.1096/fj.201601223rrr] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 02/21/2017] [Indexed: 11/11/2022]
Abstract
Erythropoietin (EPO) is the cytokine that regulates red blood cell production. Less understood is the nonerythroid action of EPO, including metabolic regulation of fat accumulation and glucose homeostasis. Although EPO treatment increased hematocrit and improved glucose tolerance in male and female mice, we observed a gender difference in EPO effects in weight control. EPO treatment reduced diet-induced weight gain from 9.6 ± 1.5 to 4.2 ± 1.4 g in male mice (P < 0.001), while the weight gain in female mice was similar (4.7 ± 2.0 g with PBS treatment and 3.3 ± 2.1 g with EPO treatment). EPO treatment also reduced weight gain in ovariectomized female mice, while the effect was abrogated with estradiol supplementation, suggesting that the sex-differential response to EPO was associated with estrogen. Furthermore, mice with targeted deletion of EPO receptor in white adipose tissue exhibited sex-differential phenotype in weight control and glucose sensitivity, and EPO receptor gene expression was reduced in wild-type female mice, suggesting that white adipose tissue plays an integral role in mediating the metabolic effects of EPO. Our data provide evidence for a sex-differential response to EPO in weight control in mice and underscore the potential for gender specific EPO action beyond erythropoiesis.-Zhang, Y., Rogers, H. M., Zhang, X., Noguchi, C. T. Sex difference in mouse metabolic response to erythropoietin.
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Affiliation(s)
- Yuanyuan Zhang
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Heather M Rogers
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Xiaojie Zhang
- Laboratory of Animal Sciences Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Constance Tom Noguchi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA;
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Wolfson GH, Vargas E, Browne VA, Moore LG, Julian CG. Erythropoietin and Soluble Erythropoietin Receptor: A Role for Maternal Vascular Adaptation to High-Altitude Pregnancy. J Clin Endocrinol Metab 2017; 102:242-250. [PMID: 27809650 PMCID: PMC5413104 DOI: 10.1210/jc.2016-1767] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 11/01/2016] [Indexed: 12/11/2022]
Abstract
CONTEXT An imbalance of proangiogenic and antiangiogenic factors is thought to induce the widespread vascular dysfunction characteristic of preeclampsia (PreE). Erythropoietin (Epo), a pleiotropic cytokine, has important angiogenic and vasoactive properties; however, its contribution to maternal vascular dysfunction in PreE is unknown. OBJECTIVES Because high altitude (HA) raises the incidence of PreE, we asked whether HA increased maternal Epo and soluble Epo receptor (sEpoR) levels and whether such effects differed between PreE and normotensive controls at HA. DESIGN, SETTING, AND PARTICIPANTS Longitudinal studies were conducted in pregnant Andean residents at HA (n = 28; 3600 m) or sea level (SL; n = 16; 300 m). Cross-sectional studies included 34 gestational age‒matched Andean PreE cases (n = 17) and controls (n = 17) in La Paz-El Alto, Bolivia (3600 to 4100 m). RESULTS HA augmented the pregnancy-associated rise in Epo relative to SL (P = 0.002), despite similar reductions in hemoglobin (Hb) across pregnancy at each altitude (7% to 9%, P < 0.001 for both). HA PreE cases had circulating Epo levels equivalent to those of controls but greater sEpoR (P < 0.05) and reduced Hb (P = 0.06, trend). CONCLUSION(S) Our findings suggest that an augmented pregnancy-associated rise in Epo may be important for successful vascular adaptation to pregnancy at HA. We further speculate that the elevated sEpoR observed in PreE vs controls at HA impedes the effect of Epo to maintain endothelial function and may, in turn, be of pathological relevance for PreE at HA.
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Affiliation(s)
| | - Enrique Vargas
- Bolivian Institute of High Altitude Biology, La Paz, Bolivia
| | | | - Lorna G. Moore
- Obstetrics and Gynecology, University of Colorado School of Medicine, Aurora, Colorado 80045; and
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Abstract
The anoxemia theory proposes that an imbalance between the demand for and supply of oxygen in the arterial wall is a key factor in the development of atherosclerosis. There is now substantial evidence that there are regions within the atherosclerotic plaque in which profound hypoxia exists; this may fundamentally change the function, metabolism, and responses of many of the cell types found within the developing plaque and whether the plaque will evolve into a stable or unstable phenotype. Hypoxia is characterized in molecular terms by the stabilization of hypoxia-inducible factor (HIF) 1α, a subunit of the heterodimeric nuclear transcriptional factor HIF-1 and a master regulator of oxygen homeostasis. The expression of HIF-1 is localized to perivascular tissues, inflammatory macrophages, and smooth muscle cells adjacent to the necrotic core of atherosclerotic lesions and regulates several genes that are important to vascular function including vascular endothelial growth factor, nitric oxide synthase, endothelin-1, and erythropoietin. This review summarizes the effects of hypoxia on the functions of cells involved in atherogenesis and the evidence for its potential importance from experimental models and clinical studies.
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Affiliation(s)
- Gordon A A Ferns
- 1 Department of Medical Education, Brighton & Sussex Medical School, Brighton, United Kingdom
| | - Lamia Heikal
- 1 Department of Medical Education, Brighton & Sussex Medical School, Brighton, United Kingdom
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Heikal L, Ghezzi P, Mengozzi M, Stelmaszczuk B, Feelisch M, Ferns GA. Erythropoietin and a nonerythropoietic peptide analog promote aortic endothelial cell repair under hypoxic conditions: role of nitric oxide. HYPOXIA 2016; 4:121-133. [PMID: 27800514 PMCID: PMC5085277 DOI: 10.2147/hp.s104377] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The cytoprotective effects of erythropoietin (EPO) and an EPO-related nonerythropoietic analog, pyroglutamate helix B surface peptide (pHBSP), were investigated in an in vitro model of bovine aortic endothelial cell injury under normoxic (21% O2) and hypoxic (1% O2) conditions. The potential molecular mechanisms of these effects were also explored. Using a model of endothelial injury (the scratch assay), we found that, under hypoxic conditions, EPO and pHBSP enhanced scratch closure by promoting cell migration and proliferation, but did not show any effect under normoxic conditions. Furthermore, EPO protected bovine aortic endothelial cells from staurosporine-induced apoptosis under hypoxic conditions. The priming effect of hypoxia was associated with stabilization of hypoxia inducible factor-1α, EPO receptor upregulation, and decreased Ser-1177 phosphorylation of endothelial nitric oxide synthase (NOS); the effect of hypoxia on the latter was rescued by EPO. Hypoxia was associated with a reduction in nitric oxide (NO) production as assessed by its oxidation products, nitrite and nitrate, consistent with the oxygen requirement for endogenous production of NO by endothelial NOS. However, while EPO did not affect NO formation in normoxia, it markedly increased NO production, in a manner sensitive to NOS inhibition, under hypoxic conditions. These data are consistent with the notion that the tissue-protective actions of EPO-related cytokines in pathophysiological settings associated with poor oxygenation are mediated by NO. These findings may be particularly relevant to atherogenesis and postangioplasty restenosis.
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Affiliation(s)
- Lamia Heikal
- Brighton and Sussex Medical School, Falmer, Brighton
| | - Pietro Ghezzi
- Brighton and Sussex Medical School, Falmer, Brighton
| | | | - Blanka Stelmaszczuk
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital and Institute for Life Sciences, Southampton, UK
| | - Martin Feelisch
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton General Hospital and Institute for Life Sciences, Southampton, UK
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Reddy MK, Vasir JK, Hegde GV, Joshi SS, Labhasetwar V. Erythropoietin Induces Excessive Neointima Formation: A Study in a Rat Carotid Artery Model of Vascular Injury. J Cardiovasc Pharmacol Ther 2016; 12:237-47. [PMID: 17875952 DOI: 10.1177/1074248406297326] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A therapeutic strategy that would mitigate the events leading to hyperplasia and facilitate re-endothelialization of an injured artery after balloon angioplasty could be effective for a long-term patency of the artery. It is hypothesized that erythropoietin (EPO), which has both anti-inflammatory and antiapoptotic properties, will prevent hyperplasia, and its ability to proliferate and mobilize endothelial progenitor cells will re-endothelialize the injured artery. To test this hypothesis, EPO (5000 IU/kg) in solution was injected intraperitoneally 6 hours before vascular injury and then on every alternate day for a week or as a single dose (5000 IU/kg) in a sustained release gel formulation 1 week before the vascular injury. Morphometric analysis revealed nearly continuous re-endothelialization of the injured artery in EPO solution-treated animals (90% vs less than 20% in saline control); however, the treatment also caused excessive neointima formation (intima/media ratio, 2.10 ± 0.09 vs 1.60 ± 0.02 saline control, n = 5, P < .001). The EPO gel also induced similar excessive neointima formation. Immunohistochemical analysis of the injured arteries from the animals treated with EPO solution demonstrated a significant angiogenic response in adventitia and media, thus explaining the formation of excessive neointima. Although the results are in contrast to expectation, they explain a greater degree of stenosis seen in hemodialysis access fistulas in patients who are on EPO therapy for anemic condition. The results also caution the use of EPO, particularly in patients who are at a risk of vascular injury or are suffering from an atherosclerotic condition.
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Affiliation(s)
- Maram K Reddy
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Bidirectional signalling between EphA2 and ephrinA1 increases tubular cell attachment, laminin secretion and modulates erythropoietin expression after renal hypoxic injury. Pflugers Arch 2016; 468:1433-48. [PMID: 27228995 DOI: 10.1007/s00424-016-1838-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/01/2016] [Accepted: 05/10/2016] [Indexed: 10/21/2022]
Abstract
Acute kidney injury (AKI) is common in hospitalized patients and has a poor prognosis, the severity of AKI being linked to progression to chronic kidney disease. This stresses the need to search for protective mechanisms during the acute phase. We investigated kidney repair after hypoxic injury using a rat model of renal artery branch ligation, which led to an oxygen gradient vertical to the corticomedullary axis. Three distinct zones were observed: tubular necrosis, infarction border zone and preserved normal tissue. EphA2 is a receptor tyrosine kinase with pivotal roles in cell architecture, migration and survival, upon juxtacrine contact with its membrane-bound ligand EphrinA1. Following hypoxia, EphA2 was up-regulated in cortical and medullary tubular cells, while EphrinA1 was up-regulated in interstitial cells adjacent to peritubular capillaries. Moreover, erythropoietin (EPO) messenger RNA (mRNA) was strongly expressed in the border zone of infarcted kidney within the first 6 h. To gain more insight into the biological impact of EphA2 and EphrinA1 up-regulation, we activated the signalling pathways in vitro using recombinant EphrinA1/Fc or EphA2/Fc proteins. Stimulation of EphA2 forward signalling in the proximal tubular cell line HK2 increased cell attachment and laminin secretion at the baso-lateral side. Conversely, activation of reverse signalling through EphrinA1 expressed by Hep3B cells promoted EPO production at both the transcriptional and protein level. Strikingly, in co-culture experiments, juxtacrine contact between EphA2 expressing MDCK and EphrinA1 expressing Hep3B was sufficient to induce a significant up-regulation of EPO mRNA production in the latter cells, even in the absence of hypoxic conditions. The synergistic effects of EphA2 and hypoxia led to a 15-20-fold increase of EPO expression. Collectively, our results suggest an important role of EphA2/EphrinA1 signalling in kidney repair after hypoxic injury through stimulation of (i) tubular cell attachment, (ii) secretion of basal membrane proteins and (iii) EPO production. These findings could thus pave the way to new therapeutic approaches.
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Kumarasinghe G, Gao L, Hicks M, Villanueva J, Doyle A, Rao P, Ru Qiu M, Jabbour A, Iyer A, Chew HC, Hayward CS, Macdonald P. Improved heart function from older donors using pharmacologic conditioning strategies. J Heart Lung Transplant 2016; 35:636-46. [DOI: 10.1016/j.healun.2015.12.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 10/22/2015] [Accepted: 12/21/2015] [Indexed: 10/22/2022] Open
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Su J, Li Z, Cui S, Ji L, Geng H, Chai K, Ma X, Bai Z, Yang Y, Wuren T, Ge RL, Rondina MT. The Local HIF-2α/EPO Pathway in the Bone Marrow is Associated with Excessive Erythrocytosis and the Increase in Bone Marrow Microvessel Density in Chronic Mountain Sickness. High Alt Med Biol 2015; 16:318-30. [PMID: 26625252 DOI: 10.1089/ham.2015.0015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
AIM Chronic mountain sickness (CMS) is characterized by excessive erythrocytosis, and angiogenesis may be involved in the pathogenesis of this disease. The bone marrow niche is the primary site of erythropoiesis and angiogenesis. This study was aimed at investigating the associations of the levels of hypoxia-inducible factors (HIFs), erythropoietin (EPO), and erythropoietin receptor (EPOR), as well as microvessel density (MVD) in the bone marrow with CMS. RESULTS A total of 34 patients with CMS and 30 control subjects residing in areas at altitudes of 3000-4500 m were recruited for this study. The mRNA and protein expression of HIF-2α and EPO in the bone marrow cells was significantly higher in the CMS patients than in the controls. Moreover, changes in HIF-2α expression in CMS patients were significantly correlated with EPO and hemoglobin levels. In contrast, the expression of mRNA and protein expression of HIF-1α and EPOR did not differ significantly between the CMS and control patients. Increased MVD was observed in the bone marrow of the patients with CMS and it was significantly correlated with hemoglobin. CONCLUSIONS Bone marrow cells of CMS patients may show enhanced activity of the HIF-2α/EPO pathway, and EPO may regulate the erythropoiesis and vasculogenesis through autocrine or/and paracrine mechanisms in the bone marrow niche. The increased MVD in the bone marrow of CMS patients appears to be involved in the pathogenesis of this disease.
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Affiliation(s)
- Juan Su
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Zhanquan Li
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Sen Cui
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Linhua Ji
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Hui Geng
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Kexia Chai
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Xiaojing Ma
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China .,2 Department of Hematology, Qinghai University Affiliated Hospital , Xining, China
| | - Zhenzhong Bai
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China
| | - Yingzhong Yang
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China
| | - Tana Wuren
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China
| | - Ri-Li Ge
- 1 Research Center for High Altitude Medicine, Qinghai University , Xining, China
| | - Matthew T Rondina
- 3 Division of General Internal Medicine and University Healthcare Thrombosis Service, Department of Internal Medicine, University of Utah Health Sciences Center , Salt Lake City, Utah
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Abstract
Vascular homeostasis is regulated by complex interactions between many vascular cell components, including endothelial cells, vascular smooth muscle cells (VSMCs), adventitial inflammatory cells, and autonomic nervous system. The balance between oxidant and antioxidant systems determines intracellular redox status, and their imbalance can cause oxidative stress. Excessive oxidative stress is one of the important stimuli that induce cellular damage and dysregulation of vascular cell components, leading to vascular diseases through multiple pathways. Cyclophilin A (CyPA) is one of the causative proteins that mediate oxidative stress-induced cardiovascular dysfunction. CyPA was initially discovered as the intracellular receptor of the immunosuppressive drug cyclosporine 30 years ago. However, recent studies have established that CyPA is secreted from vascular cell components, such as endothelial cells and VSMCs. Extracellular CyPA augments the development of cardiovascular diseases. CyPA secretion is regulated by Rho-kinase, which contributes to the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. We recently reported that plasma CyPA levels are significantly higher in patients with coronary artery disease, which is associated with increased numbers of stenotic coronary arteries and the need for coronary intervention in such patients. Furthermore, we showed that the vascular erythropoietin (Epo)/Epo receptor system plays an important role in production of nitric oxide and maintenance of vascular redox state and homeostasis, with a potential mechanistic link to the Rho-kinase-CyPA pathway. In this article, I review the data on the protective role of the vascular Epo/Epo receptor system and discuss the roles of the CyPA/Rho-kinase system in cardiovascular diseases.
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Affiliation(s)
- Kimio Satoh
- Department of Cardiovascular Medicine, Tohoku University Graduate School of Medicine
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Enhanced brain release of erythropoietin, cytokines and NO during carotid clamping. Neurol Sci 2015; 37:243-52. [PMID: 26494654 DOI: 10.1007/s10072-015-2398-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 10/08/2015] [Indexed: 01/29/2023]
Abstract
Although effective and safe, carotid endarterectomy (CEA) implies a reduced blood flow to the brain and likely an ischemia/reperfusion event. The high rate of uneventful outcomes associated with CEA suggests the activation of brain endogenous protection mechanisms aimed at limiting the possible ischemia/reperfusion damage. This study aims at assessing whether CEA triggers protective mechanisms such as brain release of erythropoietin and nitric oxide. CEA was performed in 12 patients; blood samples were withdrawn simultaneously from the surgically exposed ipsilateral jugular and leg veins before, during (2 and 40 min) and after clamp removal (2 min). Plasma antioxidant capacity, carbonylated proteins, erythropoietin, nitrates and nitrites (NOx) were determined. No changes in intraoperative EEG, peripheral and transcranial blood oxygen saturation were detectable, and no patients showed any neurologic sign after the intervention. Antioxidant capacity and protein carbonylation in plasma were unaffected. Differently, erythropoietin, VEGF, TNF-α and NOx increased during clamping in the jugular blood (2 and 40 min), while no changes were observed in the peripheral circulation. These results show that blood erythropoietin, VEGF, TNF-α, and NOx increased in the brain during uncomplicated CEA. This may represent an endogenous self-activated neuroprotective mechanism aimed at the prevention of ischemia/reperfusion damage.
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Wright DG, Wright EC, Narva AS, Noguchi CT, Eggers PW. Association of Erythropoietin Dose and Route of Administration with Clinical Outcomes for Patients on Hemodialysis in the United States. Clin J Am Soc Nephrol 2015; 10:1822-30. [PMID: 26358266 PMCID: PMC4594062 DOI: 10.2215/cjn.01590215] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 06/30/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Recombinant human erythropoietin (epoetin) is used routinely to increase blood hemoglobin levels in patients with ESRD and anemia. Although lower doses of epoetin are required to achieve equivalent hemoglobin responses when administered subcutaneously rather than intravenously, standard practice has been to administer epoetin to patients on hemodialysis intravenously. Randomized trials of alternative epoetin treatment regimens in patients with kidney failure have shown that risks of cardiovascular complications and death are related to the dose levels of epoetin used. Therefore, given the dose-sparing advantages of subcutaneous epoetin administration, the possibility that treatment of patients on hemodialysis with subcutaneous epoetin might be associated with more favorable outcomes compared with intravenous treatment was investigated. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A retrospective cohort study of 62,710 adult patients on hemodialysis treated with either intravenous or subcutaneous epoetin-α and enrolled in the Centers for Medicare and Medicaid Services ESRD Clinical Performance Measures Project from 1997 to 2005 was carried out. Risks of death and/or hospitalization for cardiovascular complications (adverse composite event outcomes) during 2 years of follow-up were determined in relationship to epoetin dose and route of administration (intravenous versus subcutaneous) by multivariate Cox proportional hazard modeling adjusted for demographics and clinical parameters. RESULTS Epoetin doses used to achieve equivalent hemoglobin responses in study patients were, on average, 25% higher when epoetin was administered intravenously rather than subcutaneously (as expected). Moreover, adverse composite event outcomes were found to be significantly more likely to occur during follow-up for patients on hemodialysis managed with intravenous rather than subcutaneous epoetin (adjusted hazard ratio for adverse events within 1 year [intravenous versus subcutaneous] was 1.11 [95% confidence interval, 1.04 to 1.18]). CONCLUSIONS This study finds that treatment of patients on hemodialysis with subcutaneous epoetin is associated with more favorable clinical outcomes than those associated with intravenous epoetin treatment.
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Affiliation(s)
| | | | - Andrew S Narva
- Division of Kidney, Urologic, and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | | | - Paul W Eggers
- Division of Kidney, Urologic, and Hematologic Diseases, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
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Lykov AP, Nikonorova YV, Bondarenko NA, Poveshchenko OV, Kim II, Poveshchenko AF, Konenkov VI. Proliferation, Migration, and Production of Nitric Oxide by Bone Marrow Multipotent Mesenchymal Stromal Cells from Wistar Rats in Hypoxia and Hyperglycemia. Bull Exp Biol Med 2015; 159:443-5. [PMID: 26388580 DOI: 10.1007/s10517-015-2986-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Indexed: 01/09/2023]
Abstract
We studied proliferation, migration, and secretion of NO by bone marrow multipotent mesenchymal stromal cells from Wistar rats during conditioning under hypoxic and hyperglycemic conditions and the effect of erythropoietin on these parameters. A stimulating effect of erythropoietin on cell proliferation under normal conditions and activation of cell proliferation under conditions of hypoxia and hyperglycemia were demonstrated. Erythropoietin abolishes suppression of cell proliferation in culture with normal glucose level under conditions of H2O2-induced hypoxia, while under conditions of hyperglycemia, inhibition of cell proliferation becomes more pronounced. Hypoxia promotes activation of cell migration along the growth factor concentration gradient and addition of erythropoietin to the nutrient medium leads to a decrease in cell migration activity. Erythropoietin stimulates NO production by cells cultured under the conditions of hypoxia and hyperglycemia.
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Affiliation(s)
- A P Lykov
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia.
| | - Yu V Nikonorova
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
| | - N A Bondarenko
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
| | - O V Poveshchenko
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
| | - I I Kim
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
| | - A F Poveshchenko
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
| | - V I Konenkov
- Research Institute of Clinical and Experimental Lymphology, Novosibirsk, Russia
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Heikal L, Ghezzi P, Mengozzi M, Ferns G. Low Oxygen Tension Primes Aortic Endothelial Cells to the Reparative Effect of Tissue-Protective Cytokines. Mol Med 2015; 21:709-716. [PMID: 26349058 DOI: 10.2119/molmed.2015.00162] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/01/2015] [Indexed: 12/11/2022] Open
Abstract
Erythropoietin (EPO) has both erythropoietic and tissue-protective properties. The EPO analogues carbamylated EPO (CEPO) and pyroglutamate helix B surface peptide (pHBSP) lack the erythropoietic activity of EPO but retain the tissue-protective properties that are mediated by a heterocomplex of EPO receptor (EPOR) and the β common receptor (βCR). We studied the action of EPO and its analogues in a model of wound healing where a bovine aortic endothelial cells (BAECs) monolayer was scratched and the scratch closure was assessed over 24 h under different oxygen concentrations. We related the effects of EPO and its analogues on repair to their effect on BAECs proliferation and migration (evaluated using a micro-Boyden chamber). EPO, CEPO and pHBSP enhanced scratch closure only at lower oxygen (5%), while their effect at atmospheric oxygen (21%) was not significant. The mRNA expression of EPOR was doubled in 5% compared with 21% oxygen, and this was associated with increased EPOR assessed by immunofluorescence and Western blot. By contrast, βCR mRNA levels were similar in 5% and 21% oxygen. EPO and its analogues increased both BAECs proliferation and migration, suggesting that both may be involved in the reparative process. The priming effect of low oxygen tension on the action of tissue-protective cytokines may be of relevance to vascular disease, including atherogenesis and restenosis.
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Affiliation(s)
- Lamia Heikal
- Brighton and Sussex Medical School, Brighton, United Kingdom
| | - Pietro Ghezzi
- Brighton and Sussex Medical School, Brighton, United Kingdom
| | | | - Gordon Ferns
- Brighton and Sussex Medical School, Brighton, United Kingdom
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Adams T, Wan E, Wei Y, Wahab R, Castagna F, Wang G, Emin M, Russo C, Homma S, Le Jemtel TH, Jelic S. Secondhand Smoking Is Associated With Vascular Inflammation. Chest 2015; 148:112-119. [PMID: 25742439 PMCID: PMC4493867 DOI: 10.1378/chest.14-2045] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND The relative risk for cardiovascular diseases in passive smokers is similar to that of active smokers despite almost a 100-fold lower dose of inhaled cigarette smoke. However, the mechanisms underlying the surprising susceptibility of the vascular tissue to the toxins in secondhand smoke (SHS) have not been directly investigated. The aim of this study was to investigate directly vascular endothelial cell function in passive smokers. METHODS Using a minimally invasive method of endothelial biopsy, we investigated directly the vascular endothelium in 23 healthy passive smokers, 25 healthy active smokers, and 23 healthy control subjects who had never smoked and had no regular exposure to SHS. Endothelial nitric oxide synthase (eNOS) function (expression of basal eNOS and activated eNOS [phosphorylated eNOS at serine1177 (P-eNOS)]) and expression of markers of inflammation (nuclear factor-κB [NF-κB]) and oxidative stress (nitrotyrosine) were assessed in freshly harvested venous endothelial cells by quantitative immunofluorescence. RESULTS Expression of eNOS and P-eNOS was similarly reduced and expression of NF-κB was similarly increased in passive and active smokers compared with control subjects. Expression of nitrotyrosine was greater in active smokers than control subjects and similar in passive and active smokers. Brachial artery flow-mediated dilation was similarly reduced in passive and active smokers compared with control subjects, consistent with reduced endothelial NO bioavailability. CONCLUSIONS Secondhand smoking increases vascular endothelial inflammation and reduces active eNOS to a similar extent as active cigarette smoking, indicating direct toxic effects of SHS on the vasculature.
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Affiliation(s)
- Tessa Adams
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Elaine Wan
- Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY
| | - Ying Wei
- Division of Biostatistics, Columbia University College of Physicians and Surgeons, New York, NY
| | - Romina Wahab
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Francesco Castagna
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Gang Wang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Memet Emin
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
| | - Cesare Russo
- Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY
| | - Shunichi Homma
- Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY
| | - Thierry H Le Jemtel
- Section of Cardiology, Tulane University School of Medicine, New Orleans, LA
| | - Sanja Jelic
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, NY
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Mishra A, Mohammad G, Norboo T, Newman JH, Pasha MAQ. Lungs at high-altitude: genomic insights into hypoxic responses. J Appl Physiol (1985) 2015; 119:1-15. [DOI: 10.1152/japplphysiol.00513.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 04/20/2015] [Indexed: 11/22/2022] Open
Abstract
Hypobaric hypoxia at high altitude (HA) results in reduced blood arterial oxygen saturation, perfusion of organs with hypoxemic blood, and direct hypoxia of lung tissues. The pulmonary complications in the cells of the pulmonary arterioles due to hypobaric hypoxia are the basis of the pathophysiological mechanisms of high-altitude pulmonary edema (HAPE). Some populations that have dwelled at HA for thousands of years have evolutionarily adapted to this environmental stress; unadapted populations may react with excessive physiological responses that impair health. Individual variations in response to hypoxia and the mechanisms of HA adaptation provide insight into physiological responses. Adaptive and maladaptive responses include alterations in pathways such as oxygen sensing, hypoxia signaling, K+- and Ca2+-gated channels, redox balance, and the renin-angiotensin-aldosterone system. Physiological imbalances are linked with genetic susceptibilities, and nonhomeostatic responses in gene regulation that occur by small RNAs, histone modification, and DNA methylation predispose susceptible humans to these HA illnesses. Elucidation of the interaction of these factors will lead to a more comprehensive understanding of HA adaptations and maladaptations and will lead to new therapeutics for HA disorders related to hypoxic lungs.
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Affiliation(s)
- Aastha Mishra
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
- Department of Biotechnology, University of Pune, Pune, India
| | - Ghulam Mohammad
- Department of Medicine, SNM Hospital, Leh, Ladakh, J&K, India
| | - Tsering Norboo
- Ladakh Institute of Prevention, Leh, Ladakh, J&K, India; and
| | - John H. Newman
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - M. A. Qadar Pasha
- Department of Genomics and Molecular Medicine, Genomics and Molecular Medicine, CSIR-Institute of Genomics and Integrative Biology, Delhi, India
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69
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Chen YH, Chou CY, Sun CY. Impairment of the Cellular Distribution and Stability of the Erythropoietin Receptor Through the Direct Targeting of Aristolochic Acid. Toxicol Sci 2015; 147:246-54. [PMID: 26136230 DOI: 10.1093/toxsci/kfv125] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Aristolochic acid (AA) nephropathy is complicated with early onset and severe anemia. The molecular pathological mechanism of AA-induced anemia remains unclear. The aim of this study was to evaluate the putative pathological roles of the erythropoietin receptor (EPOR) in AA-induced anemia in both AA nephropathy zebrafish and cultured human renal tubular cells (HK2). Immunofluorescence staining experiments revealed that AA colocalizes with the EPOR in zebrafish embryos as well as in the cytoplasm of HK2 cells. After exogenous EPO stimulation, the EPOR was detected in the plasma membrane of HK cells. However, cotreatment with AA and EPO inhibited EPOR signaling and its membrane localization upon EPO stimulation. The results of studies with a protein synthesis inhibitor and a lysosome inhibitor revealed that AA accelerates the lysosomal degradation of EPOR. The molecular docking results suggest that AA may interact with the N-terminus of EPOR. Together with the results of light absorption and in vitro competition assays, we concluded that AA treatment impairs EPOR membrane localization, accelerates its lysosomal degradation, and consequently downregulates EPOR signaling by direct targeting. The results of this study may further detail the pathological mechanism of severe anemia complicated with AA nephropathy.
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Affiliation(s)
- Yau-Hung Chen
- *Department of Chemistry, Tamkang University, Tamsui, New Taipei City 251, Taiwan;
| | - Chi-Yuan Chou
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan
| | - Chiao-Yin Sun
- Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan; and Kidney Research Center, Chang Gung Memorial Hospital, Chang Gung University, School of Medicine, Taoyuan, Taiwan
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Rajapakse NW, Nanayakkara S, Kaye DM. Pathogenesis and treatment of the cardiorenal syndrome: Implications of L-arginine-nitric oxide pathway impairment. Pharmacol Ther 2015; 154:1-12. [PMID: 25989232 DOI: 10.1016/j.pharmthera.2015.05.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 01/11/2023]
Abstract
A highly complex interplay exists between the heart and kidney in the setting of both normal and abnormal physiology. In the context of heart failure, a pathophysiological condition termed the cardiorenal syndrome (CRS) exists whereby dysfunction in the heart or kidney can accelerate pathology in the other organ. The mechanisms that underpin CRS are complex, and include neuro-hormonal activation, oxidative stress and endothelial dysfunction. The endothelium plays a central role in the regulation of both cardiac and renal function, and as such impairments in endothelial function can lead to dysfunction of both these organs. In particular, reduced bioavailability of nitric oxide (NO) is a key pathophysiologic component of endothelial dysfunction. The synthesis of NO by the endothelium is critically dependent on the plasmalemmal transport of its substrate, L-arginine, via the cationic amino acid transporter-1 (CAT1). Impaired L-arginine-NO pathway activity has been demonstrated individually in heart and renal failure. Recent findings suggest abnormalities of the L-arginine-NO pathway also play a role in the pathogenesis of CRS and thus this pathway may represent a potential new target for the treatment of heart and renal failure.
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Affiliation(s)
- Niwanthi W Rajapakse
- Heart Failure Research Group, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; Department of Physiology, Monash University, Melbourne, Australia.
| | | | - David M Kaye
- Heart Failure Research Group, Baker IDI Heart and Diabetes Institute, Melbourne, Australia; Department of Medicine, Monash University, Melbourne Australia; Department of Cardiovascular Medicine, Alfred Hospital, Melbourne, Australia
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Doleschel D, Rix A, Arns S, Palmowski K, Gremse F, Merkle R, Salopiata F, Klingmüller U, Jarsch M, Kiessling F, Lederle W. Erythropoietin improves the accumulation and therapeutic effects of carboplatin by enhancing tumor vascularization and perfusion. Am J Cancer Res 2015; 5:905-18. [PMID: 26000061 PMCID: PMC4440446 DOI: 10.7150/thno.11304] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/27/2015] [Indexed: 11/05/2022] Open
Abstract
Recombinant human erythropoietin (rhuEpo) is currently under debate for the treatment of chemotherapy-induced anemia due to clinical trials showing adverse effects in Epo-treated patients and the discovery of the erythropoietin-receptor (EpoR) in tumor and endothelial cells. Here, using Epo-Cy5.5 as theranostic near-infrared fluorescent probe we analyzed the effects of rhuEpo as co-medication to carboplatin in non-small-cell-lung-cancer (NSCLC)-xenografts with different tumor cell EpoR-expression (H838 ~8-fold higher than A549). Nude mice bearing subcutaneous A549 and H838 NSCLC-xenografts received either only carboplatin or carboplatin and co-medication of rhuEpo in two different doses. Tumor sizes and relative blood volumes (rBV) were longitudinally measured by 3D-contrast-enhanced ultrasound (3D-US). Tumoral EpoR-levels were determined by combined fluorescence molecular tomography (FMT)/ micro computed tomography (µCT) hybrid imaging. We found that rhuEpo predominantly acted on the tumor endothelium. In both xenografts, rhuEpo co-medication significantly increased vessel densities, diameters and the amount of perfused vessels. Accordingly, rhuEpo induced EpoR-phoshorylation and stimulated proliferation of endothelial cells. However, compared with solely carboplatin-treated tumors, tumor growth was significantly slower in the groups co-medicated with rhuEpo. This is explained by the Epo-mediated vascular remodeling leading to improved drug delivery as obvious by a more than 2-fold higher carboplatin accumulation and significantly enhanced tumor apoptosis. In addition, co-medication of rhuEpo reduced tumor hypoxia and diminished intratumoral EpoR-levels which continuously increased during carboplatin (Cp) -treatment. These findings suggest that co-medication of rhuEpo in well balanced doses can be used to improve the accumulation of anticancer drugs. Doses and indications may be personalized and refined using theranostic EpoR-probes.
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Alnaeeli M, Noguchi CT. Erythropoietin and obesity-induced white adipose tissue inflammation: redefining the boundaries of the immunometabolism territory. Adipocyte 2015; 4:153-7. [PMID: 26167420 DOI: 10.4161/21623945.2014.978654] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/29/2014] [Accepted: 10/15/2014] [Indexed: 12/16/2022] Open
Abstract
The adipose tissue represents a critical and predominant site for the interaction between metabolic and inflammatory responses during health and disease. In the white adipose tissue microenvironment, macrophages/adipocytes cross-talk have been shown to influence the metabolic and inflammatory states of both cell types, and contribute to the development of systemic insulin resistance during obesity. Indeed, the existence of paracrine loops between mature adipocytes and macrophages, especially during obesity-induced stress, involving the release of, and response to, an array of cytokines and regulatory factors, have been extensively studied using several in vitro and in vivo model systems. Published evidence together with recent observations, brought to light the unexpected role of erythropoietin and its receptor in the regulation of white adipose tissue mass, energy homeostasis, and inflammation as demonstrated by erythropoietin effects on adipocyte development and metabolic profile, and macrophage infiltration, cytokine responses, and activation state during diet-induced obesity. In this commentary, we discuss the newly added elements and perspectives to our understanding of the erythropoietin/erythropoietin-receptor axis as a regulator of obesity-induced white adipose tissue inflammation, providing insight into its effects on cytokine responses of macrophages and adipocytes, and possible links to glucose metabolism and insulin resistance.
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Hu S, Lin ZL, Zhao ZK, Liu R, Ma L, Luo HM, Zhou FQ, Bai XD. Pyruvate Is Superior to Citrate in Oral Rehydration Solution in the Protection of Intestine via Hypoxia-Inducible Factor-1 Activation in Rats With Burn Injury. JPEN J Parenter Enteral Nutr 2015; 40:924-33. [PMID: 25802304 DOI: 10.1177/0148607115577817] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 02/02/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Recent studies have suggested that pyruvate-enriched oral rehydration solution (Pyr-ORS) may be superior to the standard bicarbonate-based ORS in the protection of intestine from ischemic injury. The aim of this study was to compare the effects of Pyr-ORS with citrate-enriched ORS (Cit-ORS) on the intestinal hypoxia-inducible factor-1 (HIF-1)-erythropoietin (EPO) signaling pathway for enteral rehydration in a rat model of burn injury. METHODS Rats were randomly assigned to 4 groups (N = 20, 2 subgroups each: n = 10): scald sham (group SS), scald with no fluid resuscitation (group SN), scald and resuscitation with enteral Cit-ORS (group SC), and scald and resuscitation with enteral Pyr-ORS (group SP). At 2.5 and 4.5 hours after a 35% total body surface area (TBSA) scald, intestinal mucosal blood flow (IMBF), contents of HIF-1, EPO, endothelial nitric oxide synthase (eNOS), nitric oxide (NO), barrier protein (ZO-1), levels of serum diamine oxidase (DAO), and intestinal mucosal histology injury score were determined. RESULTS Serum DAO activities in the scalded groups were significantly elevated, but less raised in group SP than in group SC, at 2.5 hours and at 4.5 hours after the scald. Further, group SP more profoundly preserved intestinal HIF-1 expression compared with group SC at the 2 time points. Compared with group SC, group SP had markedly elevated intestinal EPO, eNOS, and NO levels at the same time points, respectively (P < .05). Similarly, IMBF and ZO-1 levels were significantly higher in group SP than in group SC. Intestinal mucosal histopathological scores were statistically higher at 2.5 hours and 4.5 hours after scalding but were more attenuated in group SP than in group SC (P < .05). Immunofluorescence expression of intestinal mucosal ZO-1 was consistent with the above changes. The above parameters were also significantly different between groups SC and SN (all P < .05). CONCLUSION Pyr-ORS provides a superior option to Cit-ORS for the preservation of intestinal blood flow and barrier function and the attenuation of histopathological alterations in enteral resuscitation of rats with burn injury. Its underlying mechanism may be closely related to the pyruvate in activation of intestinal HIF-1-EPO signaling cascades.
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Affiliation(s)
- Sen Hu
- Key Research Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury and Repair Regeneration, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | - Zhi-Long Lin
- Key Research Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury and Repair Regeneration, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | | | - Rui Liu
- Department of Burns and Plastic Surgery, The Fifth Hospital of Harbin, Harbin, Heilongjiang Province, China
| | - Li Ma
- Department of Burns and Plastic Surgery, the Armed Police General Hospital of People's Liberation Army, Beijing, China
| | - Hong-Min Luo
- Key Research Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury and Repair Regeneration, First Hospital Affiliated to the Chinese PLA General Hospital, Beijing, China
| | - Fang-Qiang Zhou
- Fresenius Dialysis Centers at Chicago, Rolling Meadows, IL, USA Shanghai Sandai Pharmaceutical R&D Company, Pudong, Shanghai, China
| | - Xiao-Dong Bai
- Department of Burns and Plastic Surgery, the Armed Police General Hospital of People's Liberation Army, Beijing, China
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dʼUscio LV, Santhanam AVR, Katusic ZS. Erythropoietin prevents endothelial dysfunction in GTP-cyclohydrolase I-deficient hph1 mice. J Cardiovasc Pharmacol 2014; 64:514-21. [PMID: 25490417 PMCID: PMC4261745 DOI: 10.1097/fjc.0000000000000145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
: In this study, we used the mutant hph1 mouse model, which has deficiency in GTP-cyclohydrolase I (GTPCH I) activity, to test the hypothesis that erythropoietin (EPO) protects aortic wall from oxidative stress induced by uncoupling of endothelial nitric oxide synthase (eNOS). Both GTPCH I activity and tetrahydrobiopterin (BH4) levels were reduced in hph1 mice, whereas 7,8-dihydrobiopterin (7,8-BH2) levels were significantly increased. Furthermore, BH4 deficiency caused increased production of superoxide anion and hydrogen peroxide in the aorta thus resulting in impairment of endothelium-dependent relaxations to acetylcholine. Treatment of hph1 mice with recombinant human EPO (1000 U/kg, subcutaneously for 3 days) significantly decreased superoxide anion production by eNOS and improved BH4 to 7,8-BH2 ratio in aortas. EPO also significantly decreased production of hydrogen peroxide and improved endothelium-dependent relaxations in aortas of hph1 mice. In addition, EPO treatment increased protein expressions of copper-/zinc-superoxide dismutase, manganese-superoxide dismutase, and catalase in the aorta of hph1 mice. Our findings demonstrate that treatment with EPO prevented oxidative stress and endothelial dysfunction caused by eNOS uncoupling. Increased vascular expressions of antioxidants seem to be an important molecular mechanism underlying vascular protection by EPO during chronic BH4 deficiency.
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Affiliation(s)
- Livius V dʼUscio
- Departments of *Anesthesiology; and †Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN
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Wang L, Di L, Noguchi CT. Erythropoietin, a novel versatile player regulating energy metabolism beyond the erythroid system. Int J Biol Sci 2014; 10:921-39. [PMID: 25170305 PMCID: PMC4147225 DOI: 10.7150/ijbs.9518] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Accepted: 06/04/2014] [Indexed: 12/12/2022] Open
Abstract
Erythropoietin (EPO), the required cytokine for promoting the proliferation and differentiation of erythroid cells to stimulate erythropoiesis, has been reported to act as a pleiotropic cytokine beyond hematopoietic system. The various activities of EPO are determined by the widespread distribution of its cell surface EPO receptor (EpoR) in multiple tissues including endothelial, neural, myoblasts, adipocytes and other cell types. EPO activity has been linked to angiogenesis, neuroprotection, cardioprotection, stress protection, anti-inflammation and especially the energy metabolism regulation that is recently revealed. The investigations of EPO activity in animals and the expression analysis of EpoR provide more insights on the potential of EPO in regulating energy metabolism and homeostasis. The findings of crosstalk between EPO and some important energy sensors and the regulation of EPO in the cellular respiration and mitochondrial function further provide molecular mechanisms for EPO activity in metabolic activity regulation. In this review, we will summarize the roles of EPO in energy metabolism regulation and the activity of EPO in tissues that are tightly associated with energy metabolism. We will also discuss the effects of EPO in regulating oxidative metabolism and mitochondrial function, the interactions between EPO and important energy regulation factors, and the protective role of EPO from stresses that are related to metabolism, providing a brief overview of previously less appreciated EPO biological function in energy metabolism and homeostasis.
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Affiliation(s)
- Li Wang
- 1. Faculty of Health Sciences, University of Macau, SAR of People's Republic of China
| | - Lijun Di
- 1. Faculty of Health Sciences, University of Macau, SAR of People's Republic of China
| | - Constance Tom Noguchi
- 2. Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, U.S.A
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Zhang Y, Wang L, Dey S, Alnaeeli M, Suresh S, Rogers H, Teng R, Noguchi CT. Erythropoietin action in stress response, tissue maintenance and metabolism. Int J Mol Sci 2014; 15:10296-333. [PMID: 24918289 PMCID: PMC4100153 DOI: 10.3390/ijms150610296] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/23/2014] [Accepted: 05/28/2014] [Indexed: 12/20/2022] Open
Abstract
Erythropoietin (EPO) regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vascular endothelial response to increase nitric oxide production, which facilitates oxygen delivery to brain, heart and other non-hematopoietic tissues. This review discusses these and other reports of EPO action beyond red blood cell production, including EPO response affecting metabolism and obesity in animal models. Observations of EPO activity in cell and animal model systems, including mice with tissue specific deletion of EPO receptor (EpoR), suggest the potential for EPO response in metabolism and disease.
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Affiliation(s)
- Yuanyuan Zhang
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Li Wang
- Faculty of Health Sciences, University of Macau, Macau SAR, China.
| | - Soumyadeep Dey
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Mawadda Alnaeeli
- Department of Biological Sciences, Ohio University, Zanesville, OH 43701, USA.
| | - Sukanya Suresh
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Heather Rogers
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Ruifeng Teng
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Constance Tom Noguchi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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Kertmen H, Gürer B, Yilmaz ER, Arikok AT, Kanat MA, Ergüder BI, Sekerci Z. The comparative effects of recombinant human erythropoietin and darbepoetin-alpha on cerebral vasospasm following experimental subarachnoid hemorrhage in the rabbit. Acta Neurochir (Wien) 2014; 156:951-62. [PMID: 24497025 DOI: 10.1007/s00701-014-2008-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/18/2014] [Indexed: 01/24/2023]
Abstract
BACKGROUND Darbepoetin alpha is a hypersialylated analogue of erythropoietin effective for activating erythropoietin-receptors. This study investigated the vasodilator and neuroprotective effects of darbepoetin alpha on an experimental subarachnoid hemorrhage model and compared it with erythropoietin. METHODS Forty adult male New Zealand white rabbits were randomly divided into four groups of ten rabbits each: group 1 (control), group 2 (subarachnoid hemorrhage), group 3 (erythropoietin), and group 4 (darbepoetin alpha). Recombinant human erythropoietin was administered at a dose of 1,000 U/kg intraperitoneally after the induction of subarachnoid hemorrhage and continued every 8 h up to 72 h. Darbepoetin alpha was administered at a single intraperitoneal dose of 30 μg/kg. Animals were killed 72 h after subarachnoid hemorrhage. Basilar artery cross-sectional areas, arterial wall thicknesses, hippocampal degeneration scores and biochemical analyses were measured in all groups. RESULTS Both erythropoietin and darbepoetin alpha treatments were found to attenuate cerebral vasospasm and provide neuroprotection after subarachnoid hemorrhage in rabbits. Darbepoetin alpha revealed better morphometric and histopathological results than erythropoietin among experimental subarachnoid hemorrhage-induced vasospasm. CONCLUSIONS Our findings, for the first time, showed that darbepoetin alpha can prevent vasospasm and provides neuroprotection following experimental subarachnoid hemorrhage. Moreover, darbepoetin alpha showed better results when compared with erythropoietin.
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Affiliation(s)
- Hayri Kertmen
- Neurosurgery Clinic, Ministry of Health, Diskapi Yildirim Beyazit Education and Research Hospital, Ankara, Turkey
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Kuriyama S, Morio Y, Toba M, Nagaoka T, Takahashi F, Iwakami SI, Seyama K, Takahashi K. Genistein attenuates hypoxic pulmonary hypertension via enhanced nitric oxide signaling and the erythropoietin system. Am J Physiol Lung Cell Mol Physiol 2014; 306:L996-L1005. [PMID: 24705719 DOI: 10.1152/ajplung.00276.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Upregulation of the erythropoietin (EPO)/EPO receptor (EPOR) system plays a protective role against chronic hypoxia-induced pulmonary hypertension (hypoxic PH) through enhancement of endothelial nitric oxide (NO)-mediated signaling. Genistein (Gen), a phytoestrogen, is considered to ameliorate NO-mediated signaling. We hypothesized that Gen attenuates and prevents hypoxic PH. In vivo, Sprague-Dawley rats raised in a hypobaric chamber were treated with Gen (60 mkg/kg) for 21 days. Pulmonary hemodynamics and vascular remodeling were ameliorated in Gen-treated hypoxic PH rats. Gen also restored cGMP levels and phosphorylated endothelial NO synthase (p-eNOS) at Ser(1177) and p-Akt at Ser(473) expression in the lungs. Additionally, Gen potentiated plasma EPO concentration and EPOR-positive endothelial cell counts. In experiments with hypoxic PH rats' isolated perfused lungs, Gen caused NO- and phosphatidylinositol 3-kinase (PI3K)/Akt-dependent vasodilation that reversed abnormal vasoconstriction. In vitro, a combination of EPO and Gen increased the p-eNOS and the EPOR expression in human umbilical vein endothelial cells under a hypoxic environment. Moreover, Gen potentiated the hypoxic increase in EPO production from human hepatoma cells. We conclude that Gen may be effective for the prevention of hypoxic PH through the improvement of PI3K/Akt-dependent, NO-mediated signaling in association with enhancement of the EPO/EPOR system.
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Affiliation(s)
- Sachiko Kuriyama
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yoshiteru Morio
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Michie Toba
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tetsutaro Nagaoka
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Fumiyuki Takahashi
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Shin-Ichiro Iwakami
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kuniaki Seyama
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Kazuhisa Takahashi
- Department of Respiratory Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
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Cokic BBB, Cokic VP, Suresh S, Wirt S, Noguchi CT. Nitric oxide and hypoxia stimulate erythropoietin receptor via MAPK kinase in endothelial cells. Microvasc Res 2014; 92:34-40. [PMID: 24518819 DOI: 10.1016/j.mvr.2014.01.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 12/28/2022]
Abstract
Erythropoietin receptor (EPOR) expression level determines the extent of erythropoietin (EPO) response. Previously we showed that EPOR expression in endothelial cells is increased at low oxygen tension and that EPO stimulation of endothelial cells during hypoxia can increase endothelial nitric oxide (NO) synthase (eNOS) expression and activation as well as NO production. We now observe that while EPO can stimulate NO production, NO in turn can regulate EPOR expression. Human umbilical vein endothelial cells (HUVEC) treated with 10-50 μM of NO donor diethylenetriamine NONOate (DETANO) for 24h showed significant induction of EPOR gene expression at 5% and 2% of oxygen. Also human bone marrow microvascular endothelial cell line (TrHBMEC) cultured at 21 and 2% oxygen with 50 μM DETANO demonstrated a time and oxygen dependent induction of EPOR mRNA expression after 24 and 48 h, particularly at low oxygen tension. EPOR protein was also induced by DETANO at 2% oxygen in TrHBMEC and HUVEC. The activation of signaling pathways by NO donor stimulation appeared to be distinct from EPO stimulation. In reporter gene assays, DETANO treatment of HeLa cells at 2% oxygen increased EPOR promoter activity indicated by a 48% increase in luciferase activity with a 2 kb EPOR promoter fragment and a 71% increase in activity with a minimal EPOR promoter fragment containing 0.2 kb 5'. We found that DETANO activated MAPK kinase in TrHBMEC both in normoxia and hypoxia, while MAPK kinase inhibition showed significant reduction of EPOR mRNA gene expression at low oxygen tension, suggesting MAPK involvement in NO mediated induction of EPOR. Furthermore, DETANO stimulated Akt anti-apoptotic activity after 30 min in normoxia, whereas it inhibited Akt phosphorylation in hypoxia. In contrast, EPO did not significantly increase MAPK activity while EPO stimulated Akt phosphorylation in TrHBMEC in normoxia and hypoxia. These observations provide a new effect of NO on EPOR expression to enhance EPO response in endothelial cells, particularly at low oxygen tensions.
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Affiliation(s)
- Bojana B Beleslin Cokic
- Clinic for Endocrinology, Diabetes and Metabolic Diseases, Genetic Laboratory, Clinical Center of Serbia, Belgrade, Serbia.
| | - Vladan P Cokic
- Laboratory of Experimental Hematology, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Sukanya Suresh
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Stacey Wirt
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Constance Tom Noguchi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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80
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Cavallaro G, Filippi L, Bagnoli P, La Marca G, Cristofori G, Raffaeli G, Padrini L, Araimo G, Fumagalli M, Groppo M, Dal Monte M, Osnaghi S, Fiorini P, Mosca F. The pathophysiology of retinopathy of prematurity: an update of previous and recent knowledge. Acta Ophthalmol 2014; 92:2-20. [PMID: 23617889 DOI: 10.1111/aos.12049] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Retinopathy of prematurity (ROP) is a disease that can cause blindness in very low birthweight infants. The incidence of ROP is closely correlated with the weight and the gestational age at birth. Despite current therapies, ROP continues to be a highly debilitating disease. Our advancing knowledge of the pathogenesis of ROP has encouraged investigations into new antivasculogenic therapies. The purpose of this article is to review the findings on the pathophysiological mechanisms that contribute to the transition between the first and second phases of ROP and to investigate new potential therapies. Oxygen has been well characterized for the key role that it plays in retinal neoangiogenesis. Low or high levels of pO2 regulate the normal or abnormal production of hypoxia-inducible factor 1 and vascular endothelial growth factors (VEGF), which are the predominant regulators of retinal angiogenesis. Although low oxygen saturation appears to reduce the risk of severe ROP when carefully controlled within the first few weeks of life, the optimal level of saturation still remains uncertain. IGF-1 and Epo are fundamentally required during both phases of ROP, as alterations in their protein levels can modulate disease progression. Therefore, rhIGF-1 and rhEpo were tested for their abilities to prevent the loss of vasculature during the first phase of ROP, whereas anti-VEGF drugs were tested during the second phase. At present, previous hypotheses concerning ROP should be amended with new pathogenetic theories. Studies on the role of genetic components, nitric oxide, adenosine, apelin and β-adrenergic receptor have revealed new possibilities for the treatment of ROP. The genetic hypothesis that single-nucleotide polymorphisms within the β-ARs play an active role in the pathogenesis of ROP suggests the concept of disease prevention using β-blockers. In conclusion, all factors that can mediate the progression from the avascular to the proliferative phase might have significant implications for the further understanding and treatment of ROP.
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Affiliation(s)
- Giacomo Cavallaro
- NICU, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico - Università degli Studi di Milano, Milan, ItalyNICU, Medical and Surgical Feto-Neonatal Department, "A. Meyer" University Children's Hospital, Florence, ItalyDepartment of Biology, Unit of General Physiology, University of Pisa, Pisa, ItalyNeurometabolic Unit, Department of Pediatric Neurosciences, "A. Meyer" University Children's Hospital, Florence, ItalyDepartment of Ophthalmology, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milan, Italy
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81
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Erythropoietin has a restorative effect on the contractility of arteries following experimental hypoxia. J Cardiovasc Dis Res 2014; 4:164-9. [PMID: 24396255 DOI: 10.1016/j.jcdr.2013.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 08/12/2013] [Indexed: 11/21/2022] Open
Abstract
INTRODUCTION The aim of this study was to investigate the effect of erythropoietin on vascular contractility using an in vitro model of hypoxia replicating the hypoxic environment of blood vessels and surrounding adipose tissue in obesity. METHODS AND RESULTS Pharmacological in vitro studies were carried out on small mesenteric arterial segments from male Wistar rats with and without perivascular fat and endothelium. Contractile responses were investigated by wire myography under normoxia, experimental hypoxia ± erythropoietin and l-NNA. Perivascular fat exerted an anticontractile effect which was lost following the induction of experimental hypoxia. Erythropoietin prevented the loss of the anticontractile capacity when vessels were incubated for one hour before the induction of hypoxia or throughout the period of hypoxia; this was found to be independent of the function of perivascular fat, as fat denuded arteries had a similar reduction in contractility (artery no fat + hypoxia vs. artery no fat + hypoxia + erythropoietin). The mechanism by which erythropoietin was exerting its effect was found to be partially endothelium dependent and associated with an increase of nitric oxide bioavailability as nitric oxide synthase inhibition prevented the effect. CONCLUSIONS Whilst erythropoietin is working downstream from perivascular fat, it is possible that it may be therapeutically useful in obesity when hypoxia and inflammation reduce the normal activity of perivascular fat.
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Key Words
- ACh, acetylcholine
- BMI, body mass index
- CKD, chronic kidney disease
- EPO, erythropoietin
- KPSS, high potassium physiological salt solution
- LDL, low density lipoproteins
- Microcirculation
- Myograph
- NA, noradrenaline
- NO, nitric oxide
- Obesity
- PSS, physiological salt solution
- SEM, standard error of the mean
- eNOS, endothelial nitric oxide synthase
- l-NNA, Nω-nitro-l-arginine
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82
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McLoughlin P, Keane MP. Physiological and pathological angiogenesis in the adult pulmonary circulation. Compr Physiol 2013; 1:1473-508. [PMID: 23733650 DOI: 10.1002/cphy.c100034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Angiogenesis occurs during growth and physiological adaptation in many systemic organs, for example, exercise-induced skeletal and cardiac muscle hypertrophy, ovulation, and tissue repair. Disordered angiogenesis contributes to chronic inflammatory disease processes and to tumor growth and metastasis. Although it was previously thought that the adult pulmonary circulation was incapable of supporting new vessel growth, over that past 10 years new data have shown that angiogenesis within this circulation occurs both during physiological adaptive processes and as part of the pathogenic mechanisms of lung diseases. Here we review the expression of vascular growth factors in the adult lung, their essential role in pulmonary vascular homeostasis and the changes in their expression that occur in response to physiological challenges and in disease. We consider the evidence for adaptive neovascularization in the pulmonary circulation in response to alveolar hypoxia and during lung growth following pneumonectomy in the adult lung. In addition, we review the role of disordered angiogenesis in specific lung diseases including idiopathic pulmonary fibrosis, acute adult distress syndrome and both primary and metastatic tumors of the lung. Finally, we examine recent experimental data showing that therapeutic enhancement of pulmonary angiogenesis has the potential to treat lung diseases characterized by vessel loss.
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Affiliation(s)
- Paul McLoughlin
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, and St. Vincent's University Hospital, Dublin, Ireland.
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83
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Wang L, Teng R, Di L, Rogers H, Wu H, Kopp JB, Noguchi CT. PPARα and Sirt1 mediate erythropoietin action in increasing metabolic activity and browning of white adipocytes to protect against obesity and metabolic disorders. Diabetes 2013; 62:4122-31. [PMID: 23990359 PMCID: PMC3837041 DOI: 10.2337/db13-0518] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Erythropoietin (EPO) has shown beneficial effects in the regulation of obesity and metabolic syndrome; however, the detailed mechanism is still largely unknown. Here, we created mice with adipocyte-specific deletion of EPO receptor. These mice exhibited obesity and decreased glucose tolerance and insulin sensitivity, especially when fed a high-fat diet. Moreover, EPO increased oxidative metabolism, fatty acid oxidation, and key metabolic genes in adipocytes and in white adipose tissue from diet-induced obese wild-type mice. Increased metabolic activity by EPO is associated with induction of brown fat-like features in white adipocytes, as demonstrated by increases in brown fat gene expression, mitochondrial content, and uncoupled respiration. Peroxisome proliferator-activated receptor (PPAR)α was found to mediate EPO activity because a PPARα antagonist impaired EPO-mediated induction of brown fat-like gene expression and uncoupled respiration. PPARα also cooperates with Sirt1 activated by EPO through modulating the NAD+ level to regulate metabolic activity. PPARα targets, including PPARγ coactivator 1α, uncoupling protein 1, and carnitine palmitoyltransferase 1α, were increased by EPO but impaired by Sirt1 knockdown. Sirt1 knockdown also attenuated adipose response to EPO. Collectively, EPO, as a novel regulator of adipose energy homeostasis via these metabolism coregulators, provides a potential therapeutic strategy to protect against obesity and metabolic disorders.
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Affiliation(s)
- Li Wang
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Ruifeng Teng
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
- Mouse Metabolism Core Laboratory, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Lijun Di
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Heather Rogers
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Hong Wu
- Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California
| | - Jeffrey B. Kopp
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Constance Tom Noguchi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
- Corresponding author: Constance Tom Noguchi,
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84
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Luo B, Jiang M, Yang X, Zhang Z, Xiong J, Schluesener HJ, Zhang Z, Wu Y. Erythropoietin is a hypoxia inducible factor-induced protective molecule in experimental autoimmune neuritis. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1260-70. [DOI: 10.1016/j.bbadis.2013.04.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Revised: 04/07/2013] [Accepted: 04/10/2013] [Indexed: 12/30/2022]
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85
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Andrews DA, Boren BM, Turk JR, Boyce RW, He YD, Hamadeh HK, Mytych DT, Barger TE, Salimi-Moosavi H, Sloey B, Elliott S, McElroy P, Sinclair AM, Shimamoto G, Pyrah ITG, Lightfoot-Dunn RM. Dose-related Differences in the Pharmacodynamic and Toxicologic Response to a Novel Hyperglycosylated Analog of Recombinant Human Erythropoietin in Sprague-Dawley Rats with Similarly High Hematocrit. Toxicol Pathol 2013; 42:524-39. [DOI: 10.1177/0192623313486319] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We recently reported results that erythropoiesis-stimulating agent (ESA)–related thrombotic toxicities in preclinical species were not solely dependent on a high hematocrit (HCT) but also associated with increased ESA dose level, dose frequency, and dosing duration. In this article, we conclude that sequelae of an increased magnitude of ESA-stimulated erythropoiesis potentially contributed to thrombosis in the highest ESA dose groups. The results were obtained from two investigative studies we conducted in Sprague-Dawley rats administered a low (no thrombotic toxicities) or high (with thrombotic toxicities) dose level of a hyperglycosylated analog of recombinant human erythropoietin (AMG 114), 3 times weekly for up to 9 days or for 1 month. Despite similarly increased HCT at both dose levels, animals in the high-dose group had an increased magnitude of erythropoiesis measured by spleen weights, splenic erythropoiesis, and circulating reticulocytes. Resulting prothrombotic risk factors identified predominantly or uniquely in the high-dose group were higher numbers of immature reticulocytes and nucleated red blood cells in circulation, severe functional iron deficiency, and increased intravascular destruction of iron-deficient reticulocyte/red blood cells. No thrombotic events were detected in rats dosed up to 9 days suggesting a sustained high HCT is a requisite cofactor for development of ESA-related thrombotic toxicities.
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Affiliation(s)
- Dina A. Andrews
- Comparative Biology Safety Sciences, Pathology, Amgen Inc., Thousand Oaks, California, USA
| | - Babette M. Boren
- Comparative Biology Safety Sciences, Toxicology Sciences, Amgen Inc., Thousand Oaks, California, USA
| | - James R. Turk
- Comparative Biology Safety Sciences, Pathology, Amgen Inc., Thousand Oaks, California, USA
| | - Rogely W. Boyce
- Comparative Biology Safety Sciences, Pathology, Amgen Inc., Thousand Oaks, California, USA
| | - Yudong D. He
- Comparative Biology and Safety Sciences, Discovery Toxicology, Amgen Inc., Seattle, Washington, USA
| | - Hisham K. Hamadeh
- Comparative Biology and Safety Sciences, Discovery Toxicology, Amgen Inc., Thousand Oaks, California, USA
| | - Daniel T. Mytych
- Medical Sciences, Clinical Immunology, Amgen Inc., Thousand Oaks, California, USA
| | - Troy E. Barger
- Medical Sciences, Clinical Immunology, Amgen Inc., Thousand Oaks, California, USA
| | | | - Bethlyn Sloey
- Pharmacokinetics and Drug Metabolism, Amgen Inc., Thousand Oaks, California, USA
| | - Steve Elliott
- Discovery Research, Oncology Research, Amgen Inc., Thousand Oaks, California, USA
| | - Patricia McElroy
- Discovery Research, Oncology Research, Amgen Inc., Thousand Oaks, California, USA
| | - Angus M. Sinclair
- Discovery Research, Oncology Research, Amgen Inc., Thousand Oaks, California, USA
| | - Grant Shimamoto
- Therapeutic Discovery, Biologic Optimization, Amgen Inc., Thousand Oaks, California, USA
| | - Ian T. G. Pyrah
- Comparative Biology Safety Sciences, Executive and Operations, Amgen, Inc., Thousand Oaks, California, USA
| | - Ruth M. Lightfoot-Dunn
- Comparative Biology Safety Sciences, Executive and Operations, Amgen, Inc., Thousand Oaks, California, USA
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Briet M, Barhoumi T, Mian MOR, Sierra C, Boutouyrie P, Davidman M, Bercovitch D, Nessim SJ, Frisch G, Paradis P, Lipman ML, Schiffrin EL. Effects of recombinant human erythropoietin on resistance artery endothelial function in stage 4 chronic kidney disease. J Am Heart Assoc 2013; 2:e000128. [PMID: 23584809 PMCID: PMC3647261 DOI: 10.1161/jaha.113.000128] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Background Recent studies have raised concern about the safety of erythropoiesis‐stimulating agents because of evidence of increased risk of hypertension and cardiovascular morbidity and mortality in chronic kidney disease (CKD) patients. In the present study, we investigated the effects of recombinant human erythropoietin (EPO) on endothelial function of gluteal subcutaneous resistance arteries isolated from 17 stage 4 patients (estimated glomerular filtration rate 21.9±7.4 mL/min per 1.73 m2) aged 63±13 years. Methods and Results Arteries were mounted on a pressurized myograph. EPO impaired endothelium‐dependent relaxation in a concentration‐dependent manner. The maximal response to acetylcholine with EPO at 1, 10, and 20 IU/mL was reduced by 12%, 34%, and 43%, respectively, compared with the absence of EPO (P<0.001). EPO‐induced endothelial dysfunction was significantly associated with carotid stiffness and history of cardiovascular events. EPO had no effect on norepinephrine‐induced vasoconstriction or sodium nitroprusside–induced relaxation. ABT‐627, an endothelin type A receptor antagonist, and tempol, a superoxide dismutase mimetic, partially reversed the altered endothelial function in the presence of EPO (P<0.01). Increased expression of endothelin‐1 was found in the vessel wall after incubation with EPO. Conclusions EPO alters endothelial function of resistance arteries in CKD patients via a mechanism involving in part oxidative stress and signaling through an endothelin type A receptor. EPO‐induced endothelial dysfunction could contribute to deleterious effects of EPO described in large interventional trials.
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Affiliation(s)
- Marie Briet
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, McGill University, Montreal, Quebec, Canada
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87
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Fu W, Liao X, Ruan J, Li X, Chen L, Wang B, Wang K, Zhou J. Recombinant human erythropoietin preconditioning attenuates liver ischemia reperfusion injury through the phosphatidylinositol-3 kinase/AKT/endothelial nitric oxide synthase pathway. J Surg Res 2013; 183:876-84. [PMID: 23490139 DOI: 10.1016/j.jss.2013.01.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 11/13/2012] [Accepted: 01/22/2013] [Indexed: 12/16/2022]
Abstract
BACKGROUND The exact mechanism by which erythropoietin protects the liver from ischemia reperfusion (I/R) injury is not yet known. In the present study, we examined the role of protein kinase B (PKB/AKT) and endothelial nitric oxide synthase (eNOS) in the protective effect of recombinant human erythropoietin (rHuEPO) on I/R injury of the liver. MATERIALS AND METHODS We used a liver in situ I/R model. One hundred twenty adult male Sprague-Dawley rats were divided randomly into six groups. rHuEPO and (or) LY294002 were injected in the tail vein before the operation, and its effect was assessed by measuring the serum levels of aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, nitric oxide (NO), and endothelin-1 (ET-1) and by histologic analysis. The expression of erythropoietin receptor (EPOR) and eNOS was measured by real-time polymerase chain reaction. Total AKT and eNOS and phosphorylated AKT and eNOS were examined by western blot. RESULTS rHuEPO dramatically attenuated the functional and morphologic injuries. The serum levels of alanine aminotransferase and lactate dehydrogenase were significantly decreased, but the amount of NO in the serum was increased in the I/R + rHuEPO group. Accordingly, rHuEPO administration significantly ameliorated the histologic damages at 6 h after reperfusion. rHuEPO significantly stimulated the phosphorylation of AKT and eNOS in the rats after liver I/R. CONCLUSIONS The protective effect of rHuEPO in I/R injury is mediated via the activation of the phosphatidylinositol-3 kinase/AKT/eNOS signaling pathway, at least in part, by increasing p-AKT and p-eNOS and leads to the maintenance of an elevated level of NO.
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Affiliation(s)
- Wenguang Fu
- Department of Hepatobiliary Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
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88
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Abstract
Abstract
Increased microvessel density contributes to abnormal BM and spleen microenvironment in myelofibrosis (MF). Taking advantage of the JAK2V617F mutation as a marker of malignancy, in the present study, we investigated whether splenic endothelial cells (ECs) obtained from capillaries by laser microdissection or from fresh spleen tissue by cell culture or cell sorting harbored such mutation in patients bearing the mutation in their granulocytes and undergoing splenectomy for therapeutical reasons. To extend the analysis to the ECs of large vessels, endothelial tissue from the splenic vein was also studied. We found JAK2V617F+ ECs in 12 of 18 patients also bearing the mutation in their granulocytes. In 3 patients, the mutation was found in at least 2 different EC samples obtained by laser microdissection, cell culture, or cell sorting. The mutation was detected in the splenic vein ECs of 1 of 6 patients investigated. In conclusion, we provide evidence that some ECs from the spleen and splenic veins of patients with MF bear the JAK2V617F mutation. We suggest that splenic ECs are involved in the process of malignant transformation in MF.
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89
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Du G, Zhu H, Yu P, Wang H, He J, Ye L, Fu F, Zhang J, Tian J. SMND-309 promotes angiogenesis in human umbilical vein endothelial cells through activating erythropoietin receptor/STAT3/VEGF pathways. Eur J Pharmacol 2013; 700:173-80. [DOI: 10.1016/j.ejphar.2012.12.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 12/18/2012] [Accepted: 12/19/2012] [Indexed: 11/16/2022]
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90
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EPO reverses defective wound repair in hypercholesterolaemic mice by increasing functional angiogenesis. J Plast Reconstr Aesthet Surg 2012; 65:1559-68. [DOI: 10.1016/j.bjps.2012.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 04/17/2012] [Accepted: 05/06/2012] [Indexed: 11/24/2022]
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91
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Prognostic significance of left ventricular hypertrophy observed at dialysis initiation depends on the pre-dialysis use of erythropoiesis-stimulating agents. Clin Exp Nephrol 2012; 17:294-303. [PMID: 23100176 DOI: 10.1007/s10157-012-0705-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 09/28/2012] [Indexed: 01/20/2023]
Abstract
BACKGROUND Recent experimental studies suggest that erythropoietin promotes beneficial myocardial remodeling during left ventricular hypertrophy (LVH); however, such compensatory capacity may be limited due to insufficient erythropoietin production in chronic kidney disease patients. Thus, this study aimed to explore the effect of pre-dialysis erythropoiesis-stimulating agent (ESA) use on the prognostic significance of LVH in dialyzed patients. METHODS This retrospective study included 404 consecutive patients who started dialysis between 2001 and 2009. The interaction of ESA with the association between left ventricular mass index (LVMI) observed at dialysis initiation and all-cause and cardiovascular mortality was analyzed at the end of 2010 using the Cox model. RESULTS During a median follow-up of 36.5 months, 164 patients died, 31 of them from heart failure. The frequency of pre-dialysis ESA use was 58.7 % and median LVMI was 160.3 g/m(2). Of interest, patients with the lowest tertile of LVMI had worse survival compared with those with each subsequent tertile. LVMI was inversely associated with all-cause mortality [hazard ratio (HR) 0.991, 95 % confidence interval (CI) 0.988-0.995, P = 0.000] after extensive adjustment including ejection fraction, whereas the prognostic value of LVMI for cardiovascular mortality was dependent on pre-dialysis ESA use [adjusted HR 1.010, 95 % CI 0.999-1.020, P = 0.065 for pre-dialysis ESA(+) and 0.978, 95 % CI 0.967-0.989, P = 0.000 for pre-dialysis ESA(-), respectively]. CONCLUSIONS Our results suggest that reverse epidemiology may exist between LVH and mortality and that pre-dialysis ESA use may modify the prognostic significance of LVH observed at dialysis initiation for cardiovascular mortality in dialyzed patients.
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92
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Ahmet I, Lakatta EG, Talan MI. Acute hemodynamic effects of erythropoietin do not mediate its cardioprotective properties. Biol Open 2012; 1:1049-53. [PMID: 23213383 PMCID: PMC3507179 DOI: 10.1242/bio.20122378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 07/31/2012] [Indexed: 11/26/2022] Open
Abstract
Activation of nitric oxide (NO) signaling is considered, at list partially, a mechanistic basis for EPO-induced cardioprotection. Surprisingly, hemodynamic response subsequent to NO activation after EPO administration has never been reported. The objectives of this study were to evaluate the acute hemodynamic and cardiovascular responses to EPO administration, to confirm their NO genesis, and to test the hypothesis that EPO-induced cardioprotection is mediated through cardiovascular changes related to NO activation. In Experiment 1, after 3000 U/kg of rhEPO was administered intravenously to Wistar rats, arterial blood pressure, monitored via indwelling catheter, progressively declined almost immediately until it leveled off 90 minutes after injection at 20% below control level. In Experiment 2 the 25% reduction of mean blood pressure, compared to control group, was observed 2 hours after intravenous injection of either 3000 or 150 U/kg of rhEPO. Detailed pressure–volume loop analyses of cardiac performance (Experiment 3) 2 hours after intravenous injection of human or rat recombinant EPO (3000 U/kg) revealed a significant reduction of systolic function (PRSW was 33% less than control). Reduction of arterial blood pressure and systolic cardiac function in response to rhEPO were blocked in rats pretreated with a non-selective inhibitor of nitric oxide synthase (L-NAME). In Experiment 4, 24 hours after a permanent ligation of a coronary artery, myocardial infarction (MI) measured 26±3.5% of left ventricle in untreated rats. MI in rats treated with 3000 U/kg of rhEPO immediately after coronary ligation was 56% smaller. Pretreatment with L-NAME did not attenuate the beneficial effect of rhEPO on MI size, while MI size in rats treated with L-NAME alone did not differ from control. Therefore, a single injection of rhEPO resulted in a significant, NO-mediated reduction of systemic blood pressure and corresponding reduction of cardiac systolic function. However, EPO-induced protection of myocardium from ischemic damage is not associated with NO activation or NO-mediated hemodynamic responses.
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Affiliation(s)
- Ismayil Ahmet
- Laboratory of Cardiovascular Sciences, National Institute on Aging, Gerontology Research Center, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Edward G. Lakatta
- Laboratory of Cardiovascular Sciences, National Institute on Aging, Gerontology Research Center, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Mark I. Talan
- Laboratory of Cardiovascular Sciences, National Institute on Aging, Gerontology Research Center, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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93
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Inbar D, Cohen-Armon M, Neumann D. Erythropoietin-driven signalling and cell migration mediated by polyADP-ribosylation. Br J Cancer 2012; 107:1317-26. [PMID: 22955851 PMCID: PMC3494439 DOI: 10.1038/bjc.2012.395] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background: Recombinant human erythropoietin (EPO) is the leading biotechnology engineered hormone for treatment of anaemia associated with chronic conditions including kidney failure and cancer. The finding of EPO receptors on cancer cells has raised the concern that in addition to its action in erythropoiesis, EPO may promote tumour cell growth. We questioned whether EPO-induced signalling and consequent malignant cell manifestation is mediated by polyADP-ribosylation. Methods: Erythropoietin-mediated PARP (polyADP-ribose polymerase-1) activation, gene expression and core histone H4 acetylation were examined in UT7 cells, using western blot analysis, RT–PCR and immunofluorescence. Erythropoietin-driven migration of the human breast epithelial cell line MDA-MB-435 was determined by the scratch assay and in migration chambers. Results: We have found that EPO treatment induced PARP activation. Moreover, EPO-driven c-fos and Egr-1 gene expression as well as histone H4 acetylation were mediated via polyADP-ribosylation. Erythropoietin-induced cell migration was blocked by the PARP inhibitor, ABT-888, indicating an essential role for polyADP-ribosylation in this process. Conclusions: We have identified a novel pathway by which EPO-induced gene expression and breast cancer cell migration are regulated by polyADP-ribosylation. This study introduces new possibilities regarding EPO treatment for cancer-associated anaemia where combining systemic EPO treatment with targeted administration of PARP inhibitors to the tumour may allow safe treatment with EPO, minimising its possible undesirable proliferative effects on the tumour.
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Affiliation(s)
- D Inbar
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel-Aviv University, Israel
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94
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Bennis Y, Sarlon-Bartoli G, Guillet B, Lucas L, Pellegrini L, Velly L, Blot-Chabaud M, Dignat-Georges F, Sabatier F, Pisano P. Priming of late endothelial progenitor cells with erythropoietin before transplantation requires the CD131 receptor subunit and enhances their angiogenic potential. J Thromb Haemost 2012; 10:1914-28. [PMID: 22738133 DOI: 10.1111/j.1538-7836.2012.04835.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Endothelial colony-forming cells (ECFCs) are promising candidates for cell therapy of ischemic diseases. Erythropoietin (EPO) is a cytokine that promotes angiogenesis after ischemic injury. EPO receptors (EPORs) classically include two EPOR subunits, but may also associate with the β-common chain (CD131) in a newly identified receptor involved in EPO cytoprotective effects. OBJECTIVE The aim was to take advantage of the proangiogenic properties of EPO to enhance ECFC graft efficiency. We postulated that priming ECFCs by adding epoietin α in culture medium prior to experiments might increase their angiogenic properties. We also explored the role of the CD131 subunit in EPO priming of ECFCs. METHODS AND RESULTS By western blotting on cord blood ECFC lysates, we showed that EPOR and CD131 expression increased significantly after EPO priming. These proteins coimmunoprecipitated and colocalized, suggesting that they are covalently bound in ECFCs. EPO at 5 IU mL(-1) significantly stimulated proliferation, wound healing, migration and tube formation of ECFCs. EPO priming also increased ECFC resistance to H2 O2-induced apoptosis and survival in vivo. Similarly, in vivo studies showed that, as compared with non-primed ECFC injection, 5 IU mL(-1) EPO-primed ECFCs, injected intravenously 24 h after hindlimb ischemia in athymic nude mice, increased the ischemic/non-ischemic ratios of hindlimb blood flow and capillary density. These effects were all prevented by CD131 small interfering RNA transfection, and involved the phosphoinositide 3-kinase-Akt pathway. CONCLUSION These results highlight the potential role of EPO-primed ECFCs for cell-based therapy in hindlimb ischemia, and underline the critical role of CD131 as an EPO coreceptor.
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Affiliation(s)
- Y Bennis
- Aix-Marseille Université, UMR INSERM1076, Faculté de Pharmacie, Marseille, France.
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95
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Xie Z, Chen F, Wu X, Zhuang C, Zhu J, Wang J, Ji H, Wang Y, Hua X. Effects of supplemental erythropoietin on its receptor expression and signal transduction pathways in rat model of retinal detachment. Curr Eye Res 2012; 37:138-44. [PMID: 22251399 DOI: 10.3109/02713683.2011.647225] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The aim of this study was to investigate the effects of supplemental erythropoietin (EPO) on its receptor (EPOR) and signal transduction pathways in rat model of retinal detachment (RD). METHODS To investigate the effect of EPO on EPOR expression in RD rats 100, 200 or 400 ng EPO was injected into the vitreous cavity immediately after RD model was induced. Western blot and immunohistochemistry analyses were performed to measure EPOR expression. To investigate the effect of EPO on signal transduction pathways in RD rats single dose of 400 ng EPO was injected into the vitreous cavity immediately after RD model was induced. The total and phosphorylated levels of JAK2, Akt, ERK-1/2, STAT5 and NF-κB were assessed by western blot. RESULTS Western blot analysis showed that, compared with the normal control group, EPOR expression in the neurosensory retina was significantly increased in experimental RD groups (P < 0.05), but the differences were not significant between experimental RD groups (P > 0.05). Immunohistochemical examination indicated that EPOR staining on retinas became strongly positive 3 days after RD, with no significant difference in staining intensities between the treatment groups. Phosphorylated levels of JAK2, Akt, ERK-1/2, STAT5, and NF-κB were enhanced 3 days after RD, but only JAK2, Akt, and ERK-1/2 phosphorylation was further enhanced by 400 ng EPO treatment (P < 0.05). CONCLUSIONS Supplementary EPO cannot affect EPOR expression in detached retina, but EPO may activate both PI-3K/Akt and MAPK/ERK-1/2 signal transduction pathways in RD model.
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Affiliation(s)
- Zhenggao Xie
- Department of Ophthalmology, Clinical Medicine School, Yangzhou University, Subei People's Hospital of Jiangsu Province, Yangzhou, China.
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96
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Ikarashi N, Toba K, Kato K, Ozawa T, Oda M, Takayama T, Kobayashi H, Yanagawa T, Hanawa H, Suzuki T, Nakazawa M, Nomoto M, Asami F, Higuchi M, Saito H, Aizawa Y. Erythropoietin, but not asialoerythropoietin or carbamyl-erythropoietin, attenuates monocrotaline-induced pulmonary hypertension in rats. Clin Exp Hypertens 2012; 34:575-81. [PMID: 22559233 DOI: 10.3109/10641963.2012.681728] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Erythropoietin (EPO) has long been utilized for the treatment of renal anemia. The erythropoietin receptor (EPOR) is also expressed in the cardiovascular and central nervous systems in addition to an erythroid lineage, to provide an organoprotective role against several types of cellular stress. Pulmonary hypertension (PH) is a poor prognostic disease caused by primary and secondary pulmonary vascular injury. We observed the effects of EPO derivatives on monocrotaline-induced PH in rats on the supposition that EPO may protect small arteries from injury. Asialoerythropoietin (AEPO) lacks sialic acids in the termini of carbohydrate chains that results in rapid clearance from blood. Carbamyl-erythropoietin (CEPO) interacts with EPOR/βc heterodimers, but not with EPOR homodimers expressed in erythroid cells. Monocrotaline-injected rats were treated with continuous intravenous injection of 2500 ng/kg/day of EPO, AEPO, or CEPO for 21 days, and lung histology, cardiac function, and mRNA expression in the lungs were examined. Wall thickening of small arteries in the lungs and PH were improved by administration of EPO, but not by its non-hematopoietic derivatives, AEPO, or CEPO. Erythropoietin administration increased mRNA expression of the anti-apoptotic molecule, Bcl-xL, and maintained expression of the CD31 antigen. We conclude that lungs may express EPOR homoreceptors, but not heteroreceptors. Adequate serum erythropoietin levels may be essential for pulmonary protective effects.
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Affiliation(s)
- Noboru Ikarashi
- Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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97
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Emergence of the erythropoietin/erythropoietin receptor system as a novel cardiovascular therapeutic target. J Cardiovasc Pharmacol 2012; 58:570-4. [PMID: 21934628 DOI: 10.1097/fjc.0b013e318235e7bb] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Although hypoxia and ischemia are known to be involved in the pathogenesis of cardiovascular disease, specific therapeutic targets still remain elusive. To address this important issue, we have performed 2 series of experimental studies, aiming at erythropoietin (Epo)/Epo receptor (EpoR) based on the following backgrounds. Epo has long been regarded as a hematopoietic hormone that acts exclusively in the proliferation and differentiation of erythroid progenitors. Although recent studies have demonstrated that EpoR is expressed in the cardiovascular system, the potential protective role of the vascular Epo/EpoR system in vivo remains to be examined. We hypothesized that the vascular Epo/EpoR system plays an important protective role against the development of cardiovascular disease. Using vascular EpoR-deficient mouse, we demonstrated that the vascular Epo/EpoR system plays a crucial role for endothelial function and vascular homeostasis. The vascular Epo/EpoR system is important for the activation of the vascular endothelial growth factor/vascular endothelial growth factor receptor-2 system, inhibits hypoxia-induced pulmonary endothelial damage and promotes ischemia-induced angiogenesis in vivo. These results indicate that the vascular Epo/EpoR system plays an important protective role against hypoxia/ischemia, demonstrating that this system is a novel therapeutic target in cardiovascular medicine.
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98
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Hernández C, Simó R. Erythropoietin produced by the retina: its role in physiology and diabetic retinopathy. Endocrine 2012; 41:220-6. [PMID: 22167324 DOI: 10.1007/s12020-011-9579-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Accepted: 12/01/2011] [Indexed: 12/22/2022]
Abstract
Erythropoietin (Epo) is the principal regulator of erythropoiesis by inhibiting apoptosis and by stimulating the proliferation and differentiation of erythroid precursor cells. However, Epo also performs extra-erythropoietic actions of which the neuroprotective effects are among the most relevant. Apart from kidney and liver, Epo is also produced by the brain and the retina. In addition, Epo receptor (Epo-R) expression has also been found in the brain and in the retina, thus suggesting an autocrine/paracrine action which seems essential for the physiological homeostasis of both brain and retina. In this review, we will give an overview of the current concepts of the physiology of Epo and will focus on its role in the retina in both normal conditions and in the setting of diabetic retinopathy. Finally, the reasons as to why Epo could be contemplated as a potential new treatment for the early stages of diabetic retinopathy will be given.
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Affiliation(s)
- Cristina Hernández
- CIBERDEM, Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain
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Sorg H, Harder Y, Krueger C, Reimers K, Vogt PM. The nonhematopoietic effects of erythropoietin in skin regeneration and repair: from basic research to clinical use. Med Res Rev 2012; 33:637-64. [PMID: 22430919 DOI: 10.1002/med.21259] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Erythropoietin (EPO) is the main regulator of red blood cell production but there exists also a variety of nonhematopoietic properties. More recent data show that EPO is also associated with the protection of tissues suffering from ischemia and reperfusion injury as well as with improved regeneration in various organ systems, in particular the skin. This review highlights the mechanisms of EPO in the different stages of wound healing and the reparative processes in the skin emphasizing pathophysiological mechanisms and potential clinical applications. There is clear evidence that EPO effectively influences all wound-healing phases in a dose-dependent manner. This includes inflammation, tissue, and blood vessel formation as well as the remodeling of the wound. The molecular mechanism is predominantly based on an increased expression of the endothelial and inducible nitric oxide (NO) synthase with a consecutive rapid supply of NO as well as an increased content of vascular endothelial growth factor (VEGF) in the wound. The improved understanding of the functions and regulatory mechanisms of EPO in the context of wound-healing problems and ischemia/reperfusion injury, especially during flap surgery, may lead to new considerations of this growth hormone for its regular clinical application in patients.
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Affiliation(s)
- Heiko Sorg
- Department of Plastic, Hand- and Reconstructive Surgery, Hannover Medical School, 30625, Hannover, Germany.
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100
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Erythropoietin in brain development and beyond. ANATOMY RESEARCH INTERNATIONAL 2012; 2012:953264. [PMID: 22567318 PMCID: PMC3335485 DOI: 10.1155/2012/953264] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 10/27/2011] [Accepted: 11/11/2011] [Indexed: 01/17/2023]
Abstract
Erythropoietin is known as the requisite cytokine for red blood cell production. Its receptor, expressed at a high level on erythroid progenitor/precursor cells, is also found on endothelial, neural, and other cell types. Erythropoietin and erythropoietin receptor expression in the developing and adult brain suggest their possible involvement in neurodevelopment and neuroprotection. During ischemic stress, erythropoietin, which is hypoxia inducible, can contribute to brain homeostasis by increasing red blood cell production to increase the blood oxygen carrying capacity, stimulate nitric oxide production to modulate blood flow and contribute to the neurovascular response, or act directly on neural cells to provide neuroprotection as demonstrated in culture and animal models. Clinical studies of erythropoietin treatment in stroke and other diseases provide insight on safety and potential adverse effects and underscore the potential pleiotropic activity of erythropoietin. Herein, we summarize the roles of EPO and its receptor in the developing and adult brain during health and disease, providing first a brief overview of the well-established EPO biology and signaling, its hypoxic regulation, and role in erythropoiesis.
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