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Wacka E, Nicikowski J, Jarmuzek P, Zembron-Lacny A. Anemia and Its Connections to Inflammation in Older Adults: A Review. J Clin Med 2024; 13:2049. [PMID: 38610814 PMCID: PMC11012269 DOI: 10.3390/jcm13072049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 03/29/2024] [Accepted: 03/31/2024] [Indexed: 04/14/2024] Open
Abstract
Anemia is a common hematological disorder that affects 12% of the community-dwelling population, 40% of hospitalized patients, and 47% of nursing home residents. Our understanding of the impact of inflammation on iron metabolism and erythropoiesis is still lacking. In older adults, anemia can be divided into nutritional deficiency anemia, bleeding anemia, and unexplained anemia. The last type of anemia might be caused by reduced erythropoietin (EPO) activity, progressive EPO resistance of bone marrow erythroid progenitors, and the chronic subclinical pro-inflammatory state. Overall, one-third of older patients with anemia demonstrate a nutritional deficiency, one-third have a chronic subclinical pro-inflammatory state and chronic kidney disease, and one-third suffer from anemia of unknown etiology. Understanding anemia's pathophysiology in people aged 65 and over is crucial because it contributes to frailty, falls, cognitive decline, decreased functional ability, and higher mortality risk. Inflammation produces adverse effects on the cells of the hematological system. These effects include iron deficiency (hypoferremia), reduced EPO production, and the elevated phagocytosis of erythrocytes by hepatic and splenic macrophages. Additionally, inflammation causes enhanced eryptosis due to oxidative stress in the circulation. Identifying mechanisms behind age-related inflammation is essential for a better understanding and preventing anemia in older adults.
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Affiliation(s)
- Eryk Wacka
- Department of Applied and Clinical Physiology, Collegium Medicum University of Zielona Gora, 65-417 Zielona Gora, Poland; (J.N.); (A.Z.-L.)
| | - Jan Nicikowski
- Department of Applied and Clinical Physiology, Collegium Medicum University of Zielona Gora, 65-417 Zielona Gora, Poland; (J.N.); (A.Z.-L.)
| | - Pawel Jarmuzek
- Department of Neurosurgery and Neurology, Collegium Medicum University of Zielona Gora, 65-417 Zielona Gora, Poland;
| | - Agnieszka Zembron-Lacny
- Department of Applied and Clinical Physiology, Collegium Medicum University of Zielona Gora, 65-417 Zielona Gora, Poland; (J.N.); (A.Z.-L.)
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Guo Q, Luo Q, Song G. Control of muscle satellite cell function by specific exercise-induced cytokines and their applications in muscle maintenance. J Cachexia Sarcopenia Muscle 2024; 15:466-476. [PMID: 38375571 PMCID: PMC10995279 DOI: 10.1002/jcsm.13440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 01/05/2024] [Accepted: 01/14/2024] [Indexed: 02/21/2024] Open
Abstract
Exercise is recognized to play an observable role in improving human health, especially in promoting muscle hypertrophy and intervening in muscle mass loss-related diseases, including sarcopenia. Recent rapid advances have demonstrated that exercise induces the release of abundant cytokines from several tissues (e.g., liver, muscle, and adipose tissue), and multiple cytokines improve the functions or expand the numbers of adult stem cells, providing candidate cytokines for alleviating a wide range of diseases. Muscle satellite cells (SCs) are a population of muscle stem cells that are mitotically quiescent but exit from the dormancy state to become activated in response to physical stimuli, after which SCs undergo asymmetric divisions to generate new SCs (stem cell pool maintenance) and commit to later differentiation into myocytes (skeletal muscle replenishment). SCs are essential for the postnatal growth, maintenance, and regeneration of skeletal muscle. Emerging evidence reveals that exercise regulates muscle function largely via the exercise-induced cytokines that govern SC potential, but this phenomenon is complicated and confusing. This review provides a comprehensive integrative overview of the identified exercise-induced cytokines and the roles of these cytokines in SC function, providing a more complete picture regarding the mechanism of SC homeostasis and rejuvenation therapies for skeletal muscle.
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Affiliation(s)
- Qian Guo
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of BioengineeringChongqing UniversityChongqingChina
| | - Qing Luo
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of BioengineeringChongqing UniversityChongqingChina
| | - Guanbin Song
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of BioengineeringChongqing UniversityChongqingChina
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Endo Y, Zhu C, Giunta E, Guo C, Koh DJ, Sinha I. The Role of Hypoxia and Hypoxia Signaling in Skeletal Muscle Physiology. Adv Biol (Weinh) 2024; 8:e2200300. [PMID: 37817370 DOI: 10.1002/adbi.202200300] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 04/06/2023] [Indexed: 10/12/2023]
Abstract
Hypoxia and hypoxia signaling play an integral role in regulating skeletal muscle physiology. Environmental hypoxia and tissue hypoxia in muscles cue for their appropriate physiological response and adaptation, and cause an array of cellular and metabolic changes. In addition, muscle stem cells (satellite cells), exist in a hypoxic state, and this intrinsic hypoxic state correlates with their quiescence and stemness. The mechanisms of hypoxia-mediated regulation of satellite cells and myogenesis are yet to be characterized, and their seemingly contradicting effects reported leave their exact roles somewhat perplexing. This review summarizes the recent findings on the effect of hypoxia and hypoxia signaling on the key aspects of muscle physiology, namely, stem cell maintenance and myogenesis with a particular attention given to distinguish the intrinsic versus local hypoxia in an attempt to better understand their respective regulatory roles and how their relationship affects the overall response. This review further describes their mechanistic links and their possible implications on the relevant pathologies and therapeutics.
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Affiliation(s)
- Yori Endo
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
| | - Christina Zhu
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
- Texas Tech University Health Sciences Center School of Medicine, Lubbock, TX, 79430, USA
| | - Elena Giunta
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
- Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, 80539, München, Germany
| | - Cynthia Guo
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
- Warren Alpert Medical School, Brown University, Providence, RI, 02903, USA
| | - Daniel J Koh
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
| | - Indranil Sinha
- Division of Plastic and Reconstructive Surgery, Department of Surgery, Brigham and Women's Hospital, Harvard University, Boston, MA, 02115, USA
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Caimi G, Carlisi M, Presti RL. Red Blood Cell Distribution Width, Erythrocyte Indices, and Elongation Index at Baseline in a Group of Trained Subjects. J Clin Med 2023; 13:151. [PMID: 38202157 PMCID: PMC10780127 DOI: 10.3390/jcm13010151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Regular exercise elicits adaptive changes in several organs and physiological processes, including erythrocyte properties. METHODS In a group of 79 subjects (62 men and 17 women; mean age 31.37 ± 10.19 years) who trained several times a week as they practiced amateur sports, we evaluated the elongation index, markers of erythrocyte deformability, red blood cell distribution width (RDW), indicators of erythrocyte anisocytosis, hematocrit, hemoglobin, and the main erythrocyte indices (MCV, MCH, MCHC) in basal conditions. RESULTS In comparison with a group of healthy, but not training, volunteers, the values of the elongation index, and not the RDW, are increased, and this datum is accompanied by an increase in MCV and MCHC, likely related to an increased presence of circulating young erythrocytes in training subjects. We also divided the same group according to the median of the VO2max, observing that the subgroup above the median shows both an increase in the elongation index values and a decrease in MCH and MCHC. CONCLUSIONS In trained subjects, there is no correlation between the values of the elongation index and the RDW, while the interrelations among the elongation index, RDW, and main erythrocyte indices appear to be of particular interest and of a certain complexity.
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Affiliation(s)
- Gregorio Caimi
- Department of Health Promotion and Child Care, Internal Medicine and Medical Specialties, University of Palermo, 90127 Palermo, Italy;
| | - Melania Carlisi
- Department of Health Promotion and Child Care, Internal Medicine and Medical Specialties, University of Palermo, 90127 Palermo, Italy;
| | - Rosalia Lo Presti
- Department of Psychology, Educational Science and Human Movement, University of Palermo, 90127 Palermo, Italy;
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Liu Q, You J, Zhong M, Wu Z, Geng Y, Huang C. Hemoglobin level is negatively associated with sarcopenia and its components in Chinese aged 60 and above. Front Public Health 2023; 11:1081843. [PMID: 36992883 PMCID: PMC10040688 DOI: 10.3389/fpubh.2023.1081843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Introduction Sarcopenia and low hemoglobin level are common in older adults. Few studies have evaluated the association between hemoglobin level and sarcopenia and with inconsistent findings. The multifaceted effects of sarcopenia on the human body and the high prevalence of anemia in the Chinese population make it necessary to explore the association between the two. Methods Using the China Health and Retirement Longitudinal Study (CHARLS), we explored the association between hemoglobin with sarcopenia and its components in the Chinese population aged 60 and above. Multivariate logistic and Cox proportional hazards models were constructed to examine the association of hemoglobin level with sarcopenia and sarcopenia components in individuals aged 60 years or above. The subgroup analysis covered residence, body mass index level, drinking status, and smoking status were conducted. The possible difference of associations between sexes was also explored. Results With a total of 3,055 people, the hemoglobin concentration in people without sarcopenia, possible sarcopenia, and sarcopenia are 14.34 ± 2.22, 14.64 ± 2.27, and 13.58 ± 2.02 g/dl, respectively. Cross-sectional analysis showed strong evidence that hemoglobin was negatively associated with sarcopenia [Odds Ratio (OR) = 0.95, 95% Confidence Interval (CI): 0.90-0.99] and low height-adjusted appendicular skeletal muscle mass (OR = 0.91, 95% CI: 0.86-0.97). On average, a per 1 g/dl higher hemoglobin level was associated with 5% lower odds of sarcopenia (OR = 0.95, 95% CI: 0.90-0.98). The cohort study of 1,022 people demonstrated a statistically significant negative association of hemoglobin level with low physical performance [Hazard Ratio (HR) = 0.92, 95% CI: 0.85-0.99], merely with sarcopenia (HR = 0.92, 95% CI: 0.84-1.00) and skeletal muscle mass (HR = 0.95, 95% CI: 0.80-1.00). Sex-specific analysis suggested hemoglobin's association with sarcopenia, muscle mass, and physical performance in all sexes, with weaker magnitudes in females. Hemoglobin in urban residents and people with high body mass index (BMI) has a larger magnitude of the negative association with sarcopenia. Discussion Hemoglobin level associates with sarcopenia, muscle mass, and physical performance in the Chinese population aged 60 and above, with sex-specific, residence-specific, and BMI-specific effects.
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Affiliation(s)
- Qiaoling Liu
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, United Kingdom
| | - Jiuhong You
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Min Zhong
- Department of Geriatric Neurology, Affiliated Brain Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zhigang Wu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yunjie Geng
- Research Institute of Statistical Sciences, National Bureau of Statistics, Beijing, China
| | - Cheng Huang
- Department of Rehabilitation Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Lee HY, Suh SW, Hwang JH, Shin J. Responsiveness to an erythropoiesis-stimulating agent is correlated with body composition in patients undergoing chronic hemodialysis. Front Nutr 2022; 9:1044895. [PMID: 36532527 PMCID: PMC9755720 DOI: 10.3389/fnut.2022.1044895] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/18/2022] [Indexed: 11/14/2023] Open
Abstract
BACKGROUND Resistance to erythropoiesis-stimulating agents (ESA) is associated with adverse outcomes in patients undergoing chronic hemodialysis. However, the impact of body composition on ESA response remains uncertain. This study retrospectively investigated whether there is an association between the ESA resistance index (ERI) and body composition in patients undergoing chronic hemodialysis. METHODS Multifrequency bioelectrical impedance analysis was used to measure body composition every six months. The ERI was calculated by dividing the weekly body weight-adjusted erythropoietin dose by the hemoglobin concentration. The ERI values were recorded every three months. RESULTS A total of 123 patients were followed up for 24 (interquartile range 5, 75) months. The ERI was negatively correlated with body mass index, arm circumference, arm muscle circumference, body fat percentage, and visceral fat area (P = 0.057, 0.001, 0.017, 0.063, and 0.041, respectively). Patients with a higher mean ERI during the study period had an increased risk of all-cause mortality, cardiovascular events, and infection requiring hospitalization than those with a lower mean ERI (P = 0.027, 0.021, and 0.037, respectively). We also evaluated the association between the slope of body composition parameters and the ERI trend over time and found that the ERI increased over time in patients who had an increased ratio of extracellular water to total body water (P = 0.002) as well as decreased arm circumference, arm muscle circumference, visceral fat area, and phase angle (P = 0.001, P < 0.001, P = 0.036, and 0.002). CONCLUSION ESA responsiveness appears to be associated with body composition in patients undergoing chronic hemodialysis. Therefore, measures improving body composition, such as nutrition and exercise, may have a favorable effect on the response to ESA.
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Affiliation(s)
- Hyang Yun Lee
- Division of Nephrology, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, South Korea
| | - Suk-Won Suh
- Department of Surgery, Chung-Ang University Hospital, Seoul, South Korea
| | - Jin Ho Hwang
- Division of Nephrology, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, South Korea
| | - Jungho Shin
- Division of Nephrology, Department of Internal Medicine, Chung-Ang University Hospital, Seoul, South Korea
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Dziembowska I, Wójcik M, Bukowski J, Żekanowska E. Physical Training Increases Erythroferrone Levels in Men. BIOLOGY 2021; 10:biology10111215. [PMID: 34827208 PMCID: PMC8614876 DOI: 10.3390/biology10111215] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 11/14/2021] [Accepted: 11/17/2021] [Indexed: 02/07/2023]
Abstract
Intense physical activity contributes to an increased demand for red blood cells, which transport oxygen to working muscles. The purpose of this study was to assess the concentration of erythroferrone (ERFE), the novel marker of erythroid activity in athletes, during the beginning of their training season. The study group consisted of 39 athletes aged 23.24 ± 3.77 years. The study was carried out during the athletes' preparatory period of the training cycle. The control group consisted of 34 healthy men aged 22.33 ± 2.77 years. The erythropoietic activity was evaluated by determining athletes' concentrations of erythropoietin (EPO) and erythroferrone (ERFE). The level of physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). In the athletes' group, we observed higher concentrations of EPO (Me = 12.65 mIU/mL) and ERFE (40.00 pg/mL) compared to the control group (EPO: Me = 5.74 mIU/ml, p = 0.001; ERFE: Me = 25.50 pg/mL, p = 0.0034). The average intensity of physical exercise significantly differentiated the participants as far as EPO and ERFE concentrations. These results suggest that intense physical activity, at least at the beginning of the training season, may stimulate EPO production, which increases ERFE release. This seems to be an adaptative mechanism that provides adequate iron for enhanced erythropoiesis.
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Affiliation(s)
- Inga Dziembowska
- Department of Pathophysiology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Curie-Skłodowskiej 9, 85-094 Bydgoszcz, Poland; (J.B.); (E.Ż.)
- Correspondence:
| | - Małgorzata Wójcik
- Institute of Health Sciences, Hipolit Cegielski State University of Applied Sciences in Gniezno, Ks. Kard. Stefana Wyszyńskiego 38, 62-200 Gniezno, Poland;
| | - Jakub Bukowski
- Department of Pathophysiology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Curie-Skłodowskiej 9, 85-094 Bydgoszcz, Poland; (J.B.); (E.Ż.)
| | - Ewa Żekanowska
- Department of Pathophysiology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, Curie-Skłodowskiej 9, 85-094 Bydgoszcz, Poland; (J.B.); (E.Ż.)
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Tsiftsoglou AS. Erythropoietin (EPO) as a Key Regulator of Erythropoiesis, Bone Remodeling and Endothelial Transdifferentiation of Multipotent Mesenchymal Stem Cells (MSCs): Implications in Regenerative Medicine. Cells 2021; 10:cells10082140. [PMID: 34440909 PMCID: PMC8391952 DOI: 10.3390/cells10082140] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/15/2021] [Accepted: 08/17/2021] [Indexed: 02/06/2023] Open
Abstract
Human erythropoietin (EPO) is an N-linked glycoprotein consisting of 166 aa that is produced in the kidney during the adult life and acts both as a peptide hormone and hematopoietic growth factor (HGF), stimulating bone marrow erythropoiesis. EPO production is activated by hypoxia and is regulated via an oxygen-sensitive feedback loop. EPO acts via its homodimeric erythropoietin receptor (EPO-R) that increases cell survival and drives the terminal erythroid maturation of progenitors BFU-Es and CFU-Es to billions of mature RBCs. This pathway involves the activation of multiple erythroid transcription factors, such as GATA1, FOG1, TAL-1, EKLF and BCL11A, and leads to the overexpression of genes encoding enzymes involved in heme biosynthesis and the production of hemoglobin. The detection of a heterodimeric complex of EPO-R (consisting of one EPO-R chain and the CSF2RB β-chain, CD131) in several tissues (brain, heart, skeletal muscle) explains the EPO pleotropic action as a protection factor for several cells, including the multipotent MSCs as well as cells modulating the innate and adaptive immunity arms. EPO induces the osteogenic and endothelial transdifferentiation of the multipotent MSCs via the activation of EPO-R signaling pathways, leading to bone remodeling, induction of angiogenesis and secretion of a large number of trophic factors (secretome). These diversely unique properties of EPO, taken together with its clinical use to treat anemias associated with chronic renal failure and other blood disorders, make it a valuable biologic agent in regenerative medicine for the treatment/cure of tissue de-regeneration disorders.
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Affiliation(s)
- Asterios S Tsiftsoglou
- Laboratory of Pharmacology, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Nijholt KT, Meems LMG, Ruifrok WPT, Maass AH, Yurista SR, Pavez-Giani MG, Mahmoud B, Wolters AHG, van Veldhuisen DJ, van Gilst WH, Silljé HHW, de Boer RA, Westenbrink BD. The erythropoietin receptor expressed in skeletal muscle is essential for mitochondrial biogenesis and physiological exercise. Pflugers Arch 2021; 473:1301-1313. [PMID: 34142210 PMCID: PMC8302562 DOI: 10.1007/s00424-021-02577-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/16/2021] [Accepted: 05/05/2021] [Indexed: 12/13/2022]
Abstract
Erythropoietin (EPO) is a haematopoietic hormone that regulates erythropoiesis, but the EPO-receptor (EpoR) is also expressed in non-haematopoietic tissues. Stimulation of the EpoR in cardiac and skeletal muscle provides protection from various forms of pathological stress, but its relevance for normal muscle physiology remains unclear. We aimed to determine the contribution of the tissue-specific EpoR to exercise-induced remodelling of cardiac and skeletal muscle. Baseline phenotyping was performed on left ventricle and m. gastrocnemius of mice that only express the EpoR in haematopoietic tissues (EpoR-tKO). Subsequently, mice were caged in the presence or absence of a running wheel for 4 weeks and exercise performance, cardiac function and histological and molecular markers for physiological adaptation were assessed. While gross morphology of both muscles was normal in EpoR-tKO mice, mitochondrial content in skeletal muscle was decreased by 50%, associated with similar reductions in mitochondrial biogenesis, while mitophagy was unaltered. When subjected to exercise, EpoR-tKO mice ran slower and covered less distance than wild-type (WT) mice (5.5 ± 0.6 vs. 8.0 ± 0.4 km/day, p < 0.01). The impaired exercise performance was paralleled by reductions in myocyte growth and angiogenesis in both muscle types. Our findings indicate that the endogenous EPO-EpoR system controls mitochondrial biogenesis in skeletal muscle. The reductions in mitochondrial content were associated with reduced exercise capacity in response to voluntary exercise, supporting a critical role for the extra-haematopoietic EpoR in exercise performance.
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Affiliation(s)
- Kirsten T Nijholt
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Laura M G Meems
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Willem P T Ruifrok
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Alexander H Maass
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Salva R Yurista
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Mario G Pavez-Giani
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Belend Mahmoud
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Anouk H G Wolters
- Department of Cell Biology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Dirk J van Veldhuisen
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Wiek H van Gilst
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Herman H W Silljé
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - Rudolf A de Boer
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands
| | - B Daan Westenbrink
- Department of Cardiology, University Medical Centre Groningen, University of Groningen, HPC AB31, 9700 RB, P.O. Box 30.001, Groningen, The Netherlands.
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Takata T, Mae Y, Yamada K, Taniguchi S, Hamada S, Yamamoto M, Iyama T, Isomoto H. Skeletal muscle mass is associated with erythropoietin response in hemodialysis patients. BMC Nephrol 2021; 22:134. [PMID: 33863297 PMCID: PMC8052822 DOI: 10.1186/s12882-021-02346-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 04/01/2021] [Indexed: 01/25/2023] Open
Abstract
Background Hyporesponsiveness to erythropoietin stimulating agent (ESA) is associated with poor outcomes in patients with chronic kidney disease. Although ESA hyporesponsiveness and sarcopenia have a common pathophysiological background, clinical evidence linking them is scarce. The purpose of the study was to investigate the relationship between ESA responsiveness and skeletal muscle mass in hemodialysis patients. Methods This cross-sectional study analyzed 70 patients on maintenance hemodialysis who were treated with ESA. ESA responsiveness was evaluated by erythropoietin resistance index (ERI), calculated as a weekly dose of ESA divided by body weight and hemoglobin (IU/kg/week/dL), and a weekly dose of ESA/hemoglobin (IU/week/dL). A dose of ESA is equivalated to epoetin β. Correlations between ESA responsiveness and clinical parameters including skeletal muscle mass were analyzed. Results Among the 70 patients, ERI was positively correlated to age (p < 0.002) and negatively correlated to height (p < 0.001), body weight (p < 0.001), BMI (p < 0.001), skeletal muscle mass (p < 0.001), transferrin saturation (TSAT) (p = 0.049), and zinc (p = 0.006). In the multiple linear regression analysis, TSAT, zinc, and skeletal muscle mass were associated with ERI and weekly ESA dose/hemoglobin. Conclusions Skeletal muscle mass was the independent predictor for ESA responsiveness as well as TSAT and zinc. Sarcopenia is another target for the management of anemia in patients with hemodialysis.
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Affiliation(s)
- Tomoaki Takata
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan.
| | - Yukari Mae
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
| | - Kentaro Yamada
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
| | | | - Shintaro Hamada
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
| | - Marie Yamamoto
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
| | - Takuji Iyama
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
| | - Hajime Isomoto
- Division of Gastroenterology and Nephrology, Faculty of Medicine, , Tottori University, 36-1 Nishimachi, Tottori , 683-8504, Yonago, Japan
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Hypoxia Pathway Proteins are Master Regulators of Erythropoiesis. Int J Mol Sci 2020; 21:ijms21218131. [PMID: 33143240 PMCID: PMC7662373 DOI: 10.3390/ijms21218131] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 10/21/2020] [Accepted: 10/28/2020] [Indexed: 02/06/2023] Open
Abstract
Erythropoiesis is a complex process driving the production of red blood cells. During homeostasis, adult erythropoiesis takes place in the bone marrow and is tightly controlled by erythropoietin (EPO), a central hormone mainly produced in renal EPO-producing cells. The expression of EPO is strictly regulated by local changes in oxygen partial pressure (pO2) as under-deprived oxygen (hypoxia); the transcription factor hypoxia-inducible factor-2 induces EPO. However, erythropoiesis regulation extends beyond the well-established hypoxia-inducible factor (HIF)-EPO axis and involves processes modulated by other hypoxia pathway proteins (HPPs), including proteins involved in iron metabolism. The importance of a number of these factors is evident as their altered expression has been associated with various anemia-related disorders, including chronic kidney disease. Eventually, our emerging understanding of HPPs and their regulatory feedback will be instrumental in developing specific therapies for anemic patients and beyond.
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12
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Suresh S, Rajvanshi PK, Noguchi CT. The Many Facets of Erythropoietin Physiologic and Metabolic Response. Front Physiol 2020; 10:1534. [PMID: 32038269 PMCID: PMC6984352 DOI: 10.3389/fphys.2019.01534] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 12/05/2019] [Indexed: 12/30/2022] Open
Abstract
In mammals, erythropoietin (EPO), produced in the kidney, is essential for bone marrow erythropoiesis, and hypoxia induction of EPO production provides for the important erythropoietic response to ischemic stress, such as during blood loss and at high altitude. Erythropoietin acts by binding to its cell surface receptor which is expressed at the highest level on erythroid progenitor cells to promote cell survival, proliferation, and differentiation in production of mature red blood cells. In addition to bone marrow erythropoiesis, EPO causes multi-tissue responses associated with erythropoietin receptor (EPOR) expression in non-erythroid cells such neural cells, endothelial cells, and skeletal muscle myoblasts. Animal and cell models of ischemic stress have been useful in elucidating the potential benefit of EPO affecting maintenance and repair of several non-hematopoietic organs including brain, heart and skeletal muscle. Metabolic and glucose homeostasis are affected by endogenous EPO and erythropoietin administration affect, in part via EPOR expression in white adipose tissue. In diet-induced obese mice, EPO is protective for white adipose tissue inflammation and gives rise to a gender specific response in weight control associated with white fat mass accumulation. Erythropoietin regulation of fat mass is masked in female mice due to estrogen production. EPOR is also expressed in bone marrow stromal cells (BMSC) and EPO administration in mice results in reduced bone independent of the increase in hematocrit. Concomitant reduction in bone marrow adipocytes and bone morphogenic protein suggests that high EPO inhibits adipogenesis and osteogenesis. These multi-tissue responses underscore the pleiotropic potential of the EPO response and may contribute to various physiological manifestations accompanying anemia or ischemic response and pharmacological uses of EPO.
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Affiliation(s)
- Sukanya Suresh
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Praveen Kumar Rajvanshi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Constance T Noguchi
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
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13
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Wu SH, Lu IC, Tai MH, Chai CY, Kwan AL, Huang SH. Erythropoietin Alleviates Burn-induced Muscle Wasting. Int J Med Sci 2020; 17:33-44. [PMID: 31929736 PMCID: PMC6945565 DOI: 10.7150/ijms.38590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 11/05/2019] [Indexed: 12/20/2022] Open
Abstract
Background: Burn injury induces long-term skeletal muscle pathology. We hypothesized EPO could attenuate burn-induced muscle fiber atrophy. Methods: Rats were allocated into four groups: a sham burn group, an untreated burn group subjected to third degree hind paw burn, and two burn groups treated with weekly or daily EPO for four weeks. Gastrocnemius muscle was analyzed at four weeks post-burn. Results: EPO attenuated the reduction of mean myofiber cross-sectional area post-burn and the level of the protective effect was no significant difference between two EPO-treated groups (p=0.784). Furthermore, EPO decreased the expression of atrophy-related ubiquitin ligase, atrogin-1, which was up-regulated in response to burn. Compared to untreated burn rats, those receiving weekly or daily EPO groups had less cell apoptosis by TUNEL assay. EPO decreased the expression of cleaved caspase 3 (key factor in the caspase-dependent pathway) and apoptosis-inducing factor (implicated in the caspase-independent pathway) after burn. Furthermore, EPO alleviated connective tissue overproduction following burn via transforming growth factor beta 1-Smad2/3 pathway. Daily EPO group caused significant erythrocytosis compared with untreated burn group but not weekly EPO group. Conclusion: EPO therapy attenuated skeletal muscle apoptosis and fibrosis at four weeks post-burn. Weekly EPO may be a safe and effective option in muscle wasting post-burn.
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Affiliation(s)
- Sheng-Hua Wu
- Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Anesthesiology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Anesthesiology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Anesthesiology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan
| | - I-Cheng Lu
- Department of Anesthesiology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Anesthesiology, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Anesthesiology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ming-Hong Tai
- Center for Neuroscience, National Sun Yat-Sen University, Kaohsiung, Taiwan.,Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan
| | - Chee-Yin Chai
- Departments of Pathology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Aij-Lie Kwan
- Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shu-Hung Huang
- Department of Surgery, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.,Division of Plastic Surgery, Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.,Regeneration Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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14
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Sasaki KI, Ishizaki Y, Sasaki M, Nakayoshi T, Ohtsuka M, Matsuse H, Shiba N, Ueno T, Fukumoto Y. Hybrid training system-induced myokine secretion in healthy men. Cytokine 2018; 111:178-181. [PMID: 30172114 DOI: 10.1016/j.cyto.2018.08.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/07/2018] [Accepted: 08/22/2018] [Indexed: 10/28/2022]
Abstract
The hybrid training system (HTS) is a special and compact system for effective skeletal muscle training by a combined application of volitional and electrical muscle contraction. Lower limbs' muscle training using HTS has been reported to increase not only muscle strength but also plasma interleukin-6 levels; however, little is known in other cytokines. In this study, we measured 52 cytokines and creatine phosphokinase-MM in the serum of 16 healthy men before and after lower limbs' muscle training by the knee flexion and extension using HTS. Skeletal muscle volume-corrected serum concentrations of cutaneous T-cell-attracting chemokine, erythropoietin, and tumor necrosis factor-related apoptosis-inducing ligand increased immediately after the training. These increased cytokines have been reported to play important roles in wound healing, neuroprotection, and cardiovascular protection.
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Affiliation(s)
- Ken-Ichiro Sasaki
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan.
| | - Yuta Ishizaki
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Motoki Sasaki
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Takaharu Nakayoshi
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Masanori Ohtsuka
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Hiroo Matsuse
- Department of Rehabilitation, Kurume University Hospital, Kurume, Japan
| | - Naoto Shiba
- Department of Rehabilitation, Kurume University Hospital, Kurume, Japan
| | - Takafumi Ueno
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Yoshihiro Fukumoto
- Division of Cardiovascular Medicine, Department of Internal Medicine, Kurume University School of Medicine, Kurume, Japan
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15
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Pan Y, Yang XH, Guo LL, Gu YH, Qiao QY, Jin HM. Erythropoietin Reduces Insulin Resistance via Regulation of Its Receptor-Mediated Signaling Pathways in db/db Mice Skeletal Muscle. Int J Biol Sci 2017; 13:1329-1340. [PMID: 29104499 PMCID: PMC5666531 DOI: 10.7150/ijbs.19752] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 08/08/2017] [Indexed: 01/09/2023] Open
Abstract
Erythropoietin (EPO) can reduce insulin resistance (IR) in adipocytes; however, it is unknown whether EPO can decrease IR in skeletal muscle. Here we investigated whether EPO could reduce IR in type 2 diabetic mouse skeletal muscle and its possible signaling mechanisms of action. Twelve-week-old db/db diabetic mice were employed in this study. Systemic use of EPO improved glucose profiles in type 2 diabetic mice after 4 and 8 weeks treatment. EPO up-regulated EPOR protein expression in skeletal muscle, and subsequently activated downstream signaling molecules such as JAK2, IRS-1, PI3K, AKT, and eNOS. We next constructed lentivirally-delivered shRNAs against EPOR and transfected skeletal muscle cells to knockdown EPOR. EPOR knockdown inhibited EPO induced JAK2, IRS-1, PI3K, AKT, eNOS signaling transduction, autophagy and Glut 4 translocation, as well as promoted apoptosis in skeletal muscle. Thus, EPO reduces skeletal muscle IR in type 2 diabetic mice via its specific receptor, EPOR. Possible mechanisms involved in its action may include increased autophagy and reduced apoptosis in type 2 diabetic skeletal muscles, which provides a new strategy for the treatment of IR.
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Affiliation(s)
- Yu Pan
- Division of Nephrology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiu Hong Yang
- Division of Nephrology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Li Li Guo
- Hemodialysis Center, Baoshan Branch of Shanghai No.1 People's Hospital, Shanghai, China
| | - Yan Hong Gu
- Division of Nephrology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Qing Yan Qiao
- Division of Nephrology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
| | - Hui Min Jin
- Division of Nephrology, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, Shanghai, China
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16
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Lundby C, Montero D, Joyner M. Biology of VO 2 max: looking under the physiology lamp. Acta Physiol (Oxf) 2017; 220:218-228. [PMID: 27888580 DOI: 10.1111/apha.12827] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 08/26/2016] [Accepted: 10/28/2016] [Indexed: 12/20/2022]
Abstract
In this review, we argue that several key features of maximal oxygen uptake (VO2 max) should underpin discussions about the biological and reductionist determinants of its interindividual variability: (i) training-induced increases in VO2 max are largely facilitated by expansion of red blood cell volume and an associated improvement in stroke volume, which also adapts independent of changes in red blood cell volume. These general concepts are also informed by cross-sectional studies in athletes that have very high values for VO2 max. Therefore, (ii) variations in VO2 max improvements with exercise training are also likely related to variations in these physiological determinants. (iii) All previously untrained individuals will respond to endurance exercise training in terms of improvements in VO2 max provided the stimulus exceeds a certain volume and/or intensity. Thus, genetic analysis and/or reductionist studies performed to understand or predict such variations might focus specifically on DNA variants or other molecular phenomena of relevance to these physiological pathways.
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Affiliation(s)
- C. Lundby
- Zürich Center for Integrative Human Physiology; Institute of Physiology; University of Zürich; Zürich Switzerland
| | - D. Montero
- Department of Cardiology; University Hospital Zürich; Zürich Switzerland
| | - M. Joyner
- Department of Anesthesiology; Mayo Clinic; Rochester MN USA
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17
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Montero D, Breenfeldt-Andersen A, Oberholzer L, Haider T, Goetze JP, Meinild-Lundby AK, Lundby C. Erythropoiesis with endurance training: dynamics and mechanisms. Am J Physiol Regul Integr Comp Physiol 2017; 312:R894-R902. [DOI: 10.1152/ajpregu.00012.2017] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 03/06/2017] [Accepted: 03/31/2017] [Indexed: 11/22/2022]
Abstract
The purpose of the present study was to characterize the progression of red blood cell volume (RBCV) expansion and potential volumetric and endocrine regulators of erythropoiesis during endurance training (ET). Nine healthy, untrained volunteers (age = 27 ± 4 yr) underwent supervised ET consisting of 3–4 × 60 min cycle ergometry sessions per week for 8 wk. Plasma volume (PV), RBCV, and overnight fasting hematological markers were determined before and at weeks 2, 4, and 8 of ET. In addition, plasma erythropoietin (EPO), cortisol, copeptin, and proatrial natriuretic peptide concentrations were measured during a 3-h morning period at baseline and postexercise at weeks 1 and 8. PV increased from baseline (2,405 ± 335 ml) at weeks 2, 4, and 8 (+374 ± 194, +505 ± 156, and +341 ± 160 ml, respectively, P < 0.001). Increases in RBCV from baseline (1,737 ± 442 ml) were manifested at week 4 (+109 ± 114 ml, P = 0.030) and week 8 (+205 ± 109 ml, P = 0.001). Overnight fasting plasma EPO concentration increased from baseline (11.3 ± 4.8 mIU/ml) at week 2 (+2.5 ± 2.8 mIU·ml−1, P = 0.027) and returned to baseline concentration at weeks 4 and 8. Higher 3-h-postexercise EPO concentration was observed at week 1 (11.6 mIU/ml) compared with week 8 (8.4 ± 3.9 mIU/ml, P = 0.009) and baseline (9.0 ± 4.2 mIU/ml, P = 0.019). Linear relationships between EPO concentration and hematocrit (β = −56.2, P < 0.001) and cortisol (β = 0.037, P < 0.001) were detected throughout the ET intervention. In conclusion, ET leads to mild, transient increases in circulating EPO concentration, concurring with early PV expansion and lowered hematocrit, preceding gradual RBCV enhancement.
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Affiliation(s)
- David Montero
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Department of Cardiology, University Hospital Zurich, Zurich, Switzerland
| | - Andreas Breenfeldt-Andersen
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
- Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark; and
| | - Laura Oberholzer
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Thomas Haider
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Jens P. Goetze
- Department of Clinical Biochemistry, Copenhagen, and Aarhus University, Aarhus, Denmark
| | - Anne-Kristine Meinild-Lundby
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
| | - Carsten Lundby
- Zurich Center for Integrative Human Physiology, Institute of Physiology, University of Zurich, Zurich, Switzerland
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18
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Oh KJ, Lee DS, Kim WK, Han BS, Lee SC, Bae KH. Metabolic Adaptation in Obesity and Type II Diabetes: Myokines, Adipokines and Hepatokines. Int J Mol Sci 2016; 18:ijms18010008. [PMID: 28025491 PMCID: PMC5297643 DOI: 10.3390/ijms18010008] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/24/2016] [Accepted: 12/12/2016] [Indexed: 12/21/2022] Open
Abstract
Obesity and type II diabetes are characterized by insulin resistance in peripheral tissues. A high caloric intake combined with a sedentary lifestyle is the leading cause of these conditions. Whole-body insulin resistance and its improvement are the result of the combined actions of each insulin-sensitive organ. Among the fundamental molecular mechanisms by which each organ is able to communicate and engage in cross-talk are cytokines or peptides which stem from secretory organs. Recently, it was reported that several cytokines or peptides are secreted from muscle (myokines), adipose tissue (adipokines) and liver (hepatokines) in response to certain nutrition and/or physical activity conditions. Cytokines exert autocrine, paracrine or endocrine effects for the maintenance of energy homeostasis. The present review is focused on the relationship and cross-talk amongst muscle, adipose tissue and the liver as secretory organs in metabolic diseases.
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Affiliation(s)
- Kyoung-Jin Oh
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon 34141, Korea.
| | - Da Som Lee
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
| | - Won Kon Kim
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon 34141, Korea.
| | - Baek Soo Han
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon 34141, Korea.
| | - Sang Chul Lee
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon 34141, Korea.
| | - Kwang-Hee Bae
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea.
- Department of Functional Genomics, University of Science and Technology (UST), Daejeon 34141, Korea.
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19
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Melin M, Montelius A, Rydén L, Gonon A, Hagerman I, Rullman E. Effects of enhanced external counterpulsation on skeletal muscle gene expression in patients with severe heart failure. Clin Physiol Funct Imaging 2016; 38:118-127. [PMID: 27782354 DOI: 10.1111/cpf.12392] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Accepted: 08/15/2016] [Indexed: 12/11/2022]
Abstract
Enhanced external counterpulsation (EECP) is a non-invasive treatment in which leg cuff compressions increase diastolic aortic pressure and coronary perfusion. EECP is offered to patients with refractory angina pectoris and increases physical capacity. Benefits in heart failure patients have been noted, but EECP is still considered to be experimental and its effects must be confirmed. The mechanism of action is still unclear. The aim of this study was to evaluate the effect of EECP on skeletal muscle gene expression and physical performance in patients with severe heart failure. Patients (n = 9) in NYHA III-IV despite pharmacological therapy were subjected to 35 h of EECP during 7 weeks. Before and after, lateral vastus muscle biopsies were obtained, and functional capacity was evaluated with a 6-min walk test. Skeletal muscle gene expression was evaluated using Affymetrix Hugene 1.0 arrays. Maximum walking distance increased by 15%, which is in parity to that achieved after aerobic exercise training in similar patients. Skeletal muscle gene expression analysis using Ingenuity Pathway Analysis showed an increased expression of two networks of genes with FGF-2 and IGF-1 as central regulators. The increase in gene expression was quantitatively small and no overlap with gene expression profiles after exercise training could be detected despite adequate statistical power. EECP treatment leads to a robust improvement in walking distance in patients with severe heart failure and does induce a skeletal muscle transcriptional response, but this response is small and with no significant overlap with the transcriptional signature seen after exercise training.
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Affiliation(s)
- Michael Melin
- Department of Cardiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Montelius
- Department Laboratory Medicine, Division of Clinical Physiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Lars Rydén
- Department of Cardiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Adrian Gonon
- Department Laboratory Medicine, Division of Clinical Physiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Inger Hagerman
- Department of Cardiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Eric Rullman
- Department of Cardiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.,Department Laboratory Medicine, Division of Clinical Physiology, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
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20
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BAKER JEFFM, PARISE GIANNI. Skeletal Muscle Erythropoietin Expression Is Responsive to Hypoxia and Exercise. Med Sci Sports Exerc 2016; 48:1294-301. [DOI: 10.1249/mss.0000000000000899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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21
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Pichon A, Jeton F, El Hasnaoui-Saadani R, Hagström L, Launay T, Beaudry M, Marchant D, Quidu P, Macarlupu JL, Favret F, Richalet JP, Voituron N. Erythropoietin and the use of a transgenic model of erythropoietin-deficient mice. HYPOXIA 2016; 4:29-39. [PMID: 27800506 PMCID: PMC5085313 DOI: 10.2147/hp.s83540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Despite its well-known role in red blood cell production, it is now accepted that erythropoietin (Epo) has other physiological functions. Epo and its receptors are expressed in many tissues, such as the brain and heart. The presence of Epo/Epo receptors in these organs suggests other roles than those usually assigned to this protein. Thus, the aim of this review is to describe the effects of Epo deficiency on adaptation to normoxic and hypoxic environments and to suggest a key role of Epo on main physiological adaptive functions. Our original model of Epo-deficient (Epo-TAgh) mice allowed us to improve our knowledge of the possible role of Epo in O2 homeostasis. The use of anemic transgenic mice revealed Epo as a crucial component of adaptation to hypoxia. Epo-TAgh mice survive well in hypoxic conditions despite low hematocrit. Furthermore, Epo plays a key role in neural control of ventilatory acclimatization and response to hypoxia, in deformability of red blood cells, in cerebral and cardiac angiogenesis, and in neuro- and cardioprotection.
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Affiliation(s)
- Aurélien Pichon
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris; Laboratory MOVE EA 6314, FSS, Poitiers University, Poitiers, France
| | - Florine Jeton
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
| | | | - Luciana Hagström
- Laboratório Interdisciplinar de Biociências, Universidade de Brasília, Brasília, Brazil
| | - Thierry Launay
- Unité de Biologie Intégrative des Adaptations à l'Exercice, University Paris Saclay and Genopole , University Sorbonne-Paris-Cité, Paris, France
| | - Michèle Beaudry
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Dominique Marchant
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Patricia Quidu
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex
| | - Jose-Luis Macarlupu
- High Altitude Unit, Laboratories for Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Fabrice Favret
- Laboratory "Mitochondrie, Stress Oxydant et Protection Musculaire" EA 3072, University of Strasbourg, Strasbourg, France
| | - Jean-Paul Richalet
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
| | - Nicolas Voituron
- Laboratory "Hypoxia and Lung" EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex; Laboratory of Excellence GR-Ex, Paris
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22
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Annaheim S, Jacob M, Krafft A, Breymann C, Rehm M, Boutellier U. RhEPO improves time to exhaustion by non-hematopoietic factors in humans. Eur J Appl Physiol 2016; 116:623-33. [PMID: 26729211 DOI: 10.1007/s00421-015-3322-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 12/17/2015] [Indexed: 02/07/2023]
Abstract
PURPOSE Erythropoietin (EPO) controls red cell volume (RCV) and plasma volume (PV). Therefore, injecting recombinant human EPO (rhEPO) increases RCV and most likely reduces PV. RhEPO-induced endurance improvements are explained by an increase in blood oxygen (O2) transport capacity, which increases maximum O2 uptake ([Formula: see text]O2max). However, it is debatable whether increased RCV or [Formula: see text]O2max are the main reasons for the prolongation of the time to exhaustion (t lim) at submaximal intensity. We hypothesized that high rhEPO doses in particular contracts PV such that the improvement in t lim is not as strong as at lower doses while [Formula: see text]O2max increases in a dose-dependent manner. METHODS We investigated the effects of different doses of rhEPO given during 4 weeks [placebo (P), low (L), medium (M), and high (H) dosage] on RCV, PV, [Formula: see text]O2max and t lim in 40 subjects. RESULTS While RCV increased in a dose-dependent manner, PV decreased independent of the rhEPO dose. The improvements in t lim (P +21.4 ± 23.8%; L +16.7 ± 29.8%; M +44.8 ± 62.7%; H +69.7 ± 73.4%) depended on the applied doses (R (2) = 0.89) and clearly exceeded the dose-independent [Formula: see text]O2max increases (P -1.7 ± 3.2%; L +2.6 ± 6.8%; M +5.7 ± 5.1 %; H +5.6 ± 4.3 %) after 4 weeks of rhEPO administration. Furthermore, the absolute t lim was not related (R (2) ≈ 0) to RCV or to [Formula: see text]O2max. CONCLUSIONS We conclude that a contraction in PV does not negatively affect t lim and that rhEPO improves t lim by additional, non-hematopoietic factors.
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Affiliation(s)
- Simon Annaheim
- Exercise Physiology, Institute of Human Movement Sciences, ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Laboratory for Protection and Physiology, EMPA, Swiss Federal Laboratories for Materials Science and Technology, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.,Exercise Physiology, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthias Jacob
- Department of Anaesthesiology, University Hospital, Nussbaumstrasse 20, 80336, Munich, Germany
| | - Alexander Krafft
- Division of Obstetrics, Department of Obstetrics and Gynaecology, University Hospital, 8000, Zurich, Switzerland
| | - Christian Breymann
- Division of Obstetrics, Department of Obstetrics and Gynaecology, University Hospital, 8000, Zurich, Switzerland
| | - Markus Rehm
- Department of Anaesthesiology, University Hospital, Nussbaumstrasse 20, 80336, Munich, Germany
| | - Urs Boutellier
- Exercise Physiology, Institute of Human Movement Sciences, ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Exercise Physiology, Institute of Physiology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Exercise Physiology, ETH Zurich, Rychenbergstr. 49a, 8400, Winterthur, Switzerland.
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Hoedt A, Christensen B, Nellemann B, Mikkelsen UR, Hansen M, Schjerling P, Farup J. Satellite cell response to erythropoietin treatment and endurance training in healthy young men. J Physiol 2015; 594:727-43. [PMID: 26607845 DOI: 10.1113/jp271333] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/18/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINT Erythropoietin (Epo) treatment may induce myogenic differentiation factor (MyoD) expression and prevent apoptosis in satellite cells (SCs) in murine and in vitro models. Endurance training stimulates SC proliferation in vivo in murine and human skeletal muscle. In the present study, we show, in human skeletal muscle, that treatment with an Epo-stimulating agent (darbepoetin-α) in vivo increases the content of MyoD(+) SCs in healthy young men. Moreover, we report that Epo receptor mRNA is expressed in adult human SCs, suggesting that Epo may directly target SCs through ligand-receptor interaction. Moreover, endurance training, but not Epo treatment, increases the SC content in type II myofibres, as well as the content of MyoD(+) SCs. Collectively, our results suggest that Epo treatment can regulate human SCs in vivo, supported by Epo receptor mRNA expression in human SCs. In effect, long-term Epo treatment during disease conditions involving anaemia may impact SCs and warrants further investigation. Satellite cell (SC) proliferation is observed following erythropoitin treatment in vitro in murine myoblasts and endurance training in vivo in human skeletal muscle. The present study aimed to investigate the effects of prolonged erythropoiesis-stimulating agent (ESA; darbepoetin-α) treatment and endurance training, separately and combined, on SC quantity and commitment in human skeletal muscle. Thirty-five healthy, untrained men were randomized into four groups: sedentary-placebo (SP, n = 9), sedentary-ESA (SE, n = 9), training-placebo (TP, n = 9) or training-ESA (TE, n = 8). ESA/placebo was injected once weekly and training consisted of ergometer cycling three times a week for 10 weeks. Prior to and following the intervention period, blood samples and muscle biopsies were obtained and maximal oxygen uptake (V̇O2, max) was measured. Immunohistochemical analyses were used to quantify fibre type specific SCs (Pax7(+)), myonuclei and active SCs (Pax7(+)/MyoD(+)). ESA treatment led to elevated haematocrit, whereas endurance training increased V̇O2, max. Endurance training led to an increase in SCs associated with type II fibres (P < 0.05), whereas type I fibres showed no changes. Both ESA treatment and endurance training increased Pax7(+)/MyoD(+) cells, whereas only ESA treatment increased the total content of MyoD(+) cells. Epo-R mRNA presence in adult SC was tested with real-time RT-PCR using fluorescence-activated cell sorting (CD56(+)/CD45(-)/CD31(-)) to isolate cells from a human rectus abdominis muscle and was found to be considerably higher than in whole muscle. In conclusion, endurance training and ESA treatment may separately stimulate SC commitment to the myogenic program. Furthermore, ESA-treatment may alter SC activity by direct interaction with the Epo-R expressed on SCs.
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Affiliation(s)
- Andrea Hoedt
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.,Medical Research Laboratories, Institute for Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ulla Ramer Mikkelsen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark.,Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mette Hansen
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg Hospital and Centre for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jean Farup
- Section for Sports Science, Department of Public Health, Aarhus University, Aarhus, Denmark
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24
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25
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Caillaud C, Mechta M, Ainge H, Madsen AN, Ruell P, Mas E, Bisbal C, Mercier J, Twigg S, Mori TA, Simar D, Barrès R. Chronic erythropoietin treatment improves diet-induced glucose intolerance in rats. J Endocrinol 2015; 225:77-88. [PMID: 25767056 DOI: 10.1530/joe-15-0010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/12/2015] [Indexed: 12/21/2022]
Abstract
Erythropoietin (EPO) ameliorates glucose metabolism through mechanisms not fully understood. In this study, we investigated the effect of EPO on glucose metabolism and insulin signaling in skeletal muscle. A 2-week EPO treatment of rats fed with a high-fat diet (HFD) improved fasting glucose levels and glucose tolerance, without altering total body weight or retroperitoneal fat mass. Concomitantly, EPO partially rescued insulin-stimulated AKT activation, reduced markers of oxidative stress, and restored heat-shock protein 72 expression in soleus muscles from HFD-fed rats. Incubation of skeletal muscle cell cultures with EPO failed to induce AKT phosphorylation and had no effect on glucose uptake or glycogen synthesis. We found that the EPO receptor gene was expressed in myotubes, but was undetectable in soleus. Together, our results indicate that EPO treatment improves glucose tolerance but does not directly activate the phosphorylation of AKT in muscle cells. We propose that the reduced systemic inflammation or oxidative stress that we observed after treatment with EPO could contribute to the improvement of whole-body glucose metabolism.
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Affiliation(s)
- Corinne Caillaud
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Mie Mechta
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Heidi Ainge
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Andreas N Madsen
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, N
| | - Patricia Ruell
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Emilie Mas
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Catherine Bisbal
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Jacques Mercier
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, N
| | - Stephen Twigg
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Trevor A Mori
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - David Simar
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Romain Barrès
- Exercise Health and Performance Faculty of Health Sciences, and Charles Perkins Centre, The University of Sydney, Sydney, New South Wales, Australia Faculty of Health and Medical Sciences The Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark Department of Neuroscience and Pharmacology Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark School of Medicine and Pharmacology Royal Perth Hospital, The University of Western Australia, Perth, Western Australia, Australia UMR CNRS 9214 U1046 INSERM Physiologie et Médecine Expérimentale du Cœur et des Muscles, Université de Montpellier, Montpellier, France Physiology Department CHU Arnaud de Villeneuve, Montpellier, France Department of Endocrinology Sydney Medical School, Royal Prince Alfred Hospital, University of Sydney, Camperdown, New South Wales, Australia Inflammation and Infection Research School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
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Christensen B, Nellemann B, Thorsen K, Nielsen MM, Pedersen SB, Ornstrup MJ, JØrgensen JOL, Jessen N. Prolonged erythropoietin treatment does not impact gene expression in human skeletal muscle. Muscle Nerve 2015; 51:554-61. [PMID: 25088500 DOI: 10.1002/mus.24355] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2014] [Indexed: 01/12/2023]
Abstract
INTRODUCTION We tested for the presence of erythropoietin receptor (Epo-R) in human skeletal muscle and alterations in gene expression after prolonged use of an erythropoiesis-stimulating agent (ESA). METHODS Nine healthy men were treated with ESA for 10 weeks (darbepoietin alfa). Muscle biopsies were collected before and after treatment. Alterations in gene expression were evaluated by gene array. Western blot and PCR analysis were used to test for Epo-R presence in human skeletal muscle. RESULTS Very low Epo-R mRNA levels were found, but a new and sensitive antibody did not identify Epo-R protein in human skeletal muscle. The between-subject variation in skeletal muscle gene expression was greater than that observed in response to prolonged ESA treatment. CONCLUSIONS Erythropoietin is unlikely to exert direct effects in human skeletal muscle due to a lack of Epo-R protein. Furthermore, prolonged ESA treatment does not seem to exert either direct or indirect effects on skeletal muscle gene expression.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark; Medical Research Laboratories, Aarhus University, Aarhus, Denmark; Section of Sports Sciences, Institute of Public Health, Aarhus University, Aarhus, Denmark
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Caillaud C, Connes P, Ben Saad H, Mercier J. Erythropoietin enhances whole body lipid oxidation during prolonged exercise in humans. J Physiol Biochem 2015; 71:9-16. [DOI: 10.1007/s13105-014-0374-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 12/16/2014] [Indexed: 01/29/2023]
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Guadalupe-Grau A, Plenge U, Helbo S, Kristensen M, Andersen PR, Fago A, Belhage B, Dela F, Helge JW. Effects of an 8-weeks erythropoietin treatment on mitochondrial and whole body fat oxidation capacity during exercise in healthy males. J Sports Sci 2014; 33:570-8. [DOI: 10.1080/02640414.2014.951872] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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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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Larsen MS, Vissing K, Thams L, Sieljacks P, Dalgas U, Nellemann B, Christensen B. Erythropoietin administration alone or in combination with endurance training affects neither skeletal muscle morphology nor angiogenesis in healthy young men. Exp Physiol 2014; 99:1409-20. [PMID: 25128327 DOI: 10.1113/expphysiol.2014.080606] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The aim was to investigate the ability of an erythropoiesis-stimulating agent (ESA), alone or in combination with endurance training, to induce changes in human skeletal muscle fibre and vascular morphology. In a comparative study, 36 healthy untrained men were randomly dispersed into the following four groups: sedentary-placebo (SP, n = 9); sedentary-ESA (SE, n = 9); training-placebo (TP, n = 10); or training-ESA (TE, n = 8). The ESA or placebo was injected once weekly. Training consisted of progressive bicycling three times per week for 10 weeks. Before and after the intervention period, muscle biopsies and magnetic resonance images were collected from the thigh muscles, blood was collected, body composition measured and endurance exercise performance evaluated. The ESA treatment (SE and TE) led to elevated haematocrit, and both ESA treatment and training (SE, TP and TE) increased maximal O2 uptake. With regard to skeletal muscle morphology, TP alone exhibited increases in whole-muscle cross-sectional area and fibre diameter of all fibre types. Also exclusively for TP was an increase in type IIa fibres and a corresponding decrease in type IIx fibres. Furthermore, an overall training effect (TP and TE) was statistically demonstrated in whole-muscle cross-sectional area, muscle fibre diameter and type IIa and type IIx fibre distribution. With regard to muscle vascular morphology, TP and TE both promoted a rise in capillary to muscle fibre ratio, with no differences between the two groups. There were no effects of ESA treatment on any of the muscle morphological parameters. Despite the haematopoietic effects of ESA, we provide novel evidence that endurance training rather than ESA treatment induces adaptational changes in angiogenesis and muscle morphology.
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Affiliation(s)
- Mads S Larsen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Kristian Vissing
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Line Thams
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Peter Sieljacks
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Ulrik Dalgas
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark
| | - Birgitte Nellemann
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Britt Christensen
- Section of Sports Science, Institute of Public Health, Aarhus University, Aarhus, Denmark Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
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Lamon S, Zacharewicz E, Stephens AN, Russell AP. EPO-receptor is present in mouse C2C12 and human primary skeletal muscle cells but EPO does not influence myogenesis. Physiol Rep 2014; 2:e00256. [PMID: 24760510 PMCID: PMC4002236 DOI: 10.1002/phy2.256] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The role and regulation of the pleiotropic cytokine erythropoietin (EPO) in skeletal muscle are controversial. EPO exerts its effects by binding its specific receptor (EPO‐R), which activates intracellular signaling and gene transcription in response to internal and external stress signals. EPO is suggested to play a direct role in myogenesis via the EPO‐R, but several studies have questioned the effect of EPO treatment in muscle in vitro and in vivo. The lack of certainty surrounding the use of nonspecific EPO‐R antibodies contributes to the ambiguity of the field. Our study demonstrates that the EPO‐R gene and protein are expressed at each stage of mouse C2C12 and human skeletal muscle cell proliferation and differentiation and validates a specific antibody for the detection of the EPO‐R protein. However, in our experimental conditions, EPO treatment had no effect on mouse C2C12 and human muscle cell proliferation, differentiation, protein synthesis or EPO‐R expression. While an increase in Akt and MAPK phosphorylation was observed, we demonstrate that this effect resulted from the stress caused by changing medium and not from EPO treatment. We therefore suggest that skeletal muscle EPO‐R might be present in a nonfunctional form, or too lowly expressed to play a role in muscle cell function. The EPO‐R is expressed at the gene and protein level in mouse and human myoblasts and myotubes. However, EPO treatment does not seem to activate the EPO‐R and its downstream signaling pathways in skeletal muscle cells, questioning its functionality.
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Affiliation(s)
- Séverine Lamon
- Centre for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria, Australia
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Chen F, Liu Q, Zhang ZD, Zhu XH. Co-delivery of G-CSF and EPO released from fibrin gel for therapeutic neovascularization in rat hindlimb ischemia model. Microcirculation 2014; 20:416-24. [PMID: 23294128 DOI: 10.1111/micc.12037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 01/03/2013] [Indexed: 01/10/2023]
Abstract
OBJECTIVE G-CSF and EPO have shown a notable capability in neovascularization. However, their use is limited because of untoward leucocytosis, erythrogenesis, and short half-life in the plasma. Herein, we examined whether G-CSF and EPO released from fibrin gel injected into ischemic tissues would synergistically promote neovascularization with limited systematic effects in a rat hindlimb ischemic model. METHODS AND RESULTS In vivo study, group Gel received an intramuscular injection of fibrin gel; group Gel+G-CSF received fibrin gel containing human G-CSF; group Gel+EPO received fibrin gel containing human EPO; group Gel+G-CSF&EPO received fibrin gel containing G-CSF and EPO; group G-CSF&EPO received G-CSF and EPO. Through promoting the expression of SDF-1, local high concentration of EPO could traffic CXCR4+ cells mobilized by G-CSF to enhance neovascularization in ischemic muscle. The treatment with Gel+G-CSF&EPO was superior to the other treatments on blood flow reperfusion, capillary density, and α smooth muscle actin-positive vessel density. And this treatment induced a modest WBC count increase in peripheral blood. CONCLUSIONS G-CSF and EPO released from fibrin gel had a combined effect on postischemia neovascularization. This treatment may be a novel therapeutic modality for ischemic peripheral artery disease.
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Affiliation(s)
- Feng Chen
- Department of Vascular Surgery, the second affiliated Hospital, Nanchang University, Nanchang, China.
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Abstract
Skeletal muscle is the largest organ in the body. Skeletal muscles are primarily characterized by their mechanical activity required for posture, movement, and breathing, which depends on muscle fiber contractions. However, skeletal muscle is not just a component in our locomotor system. Recent evidence has identified skeletal muscle as a secretory organ. We have suggested that cytokines and other peptides that are produced, expressed, and released by muscle fibers and exert either autocrine, paracrine, or endocrine effects should be classified as "myokines." The muscle secretome consists of several hundred secreted peptides. This finding provides a conceptual basis and a whole new paradigm for understanding how muscles communicate with other organs such as adipose tissue, liver, pancreas, bones, and brain. In addition, several myokines exert their effects within the muscle itself. Many proteins produced by skeletal muscle are dependent upon contraction. Therefore, it is likely that myokines may contribute in the mediation of the health benefits of exercise.
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Affiliation(s)
- Bente K Pedersen
- The Centre of Inflammation and Metabolism at Department of Infectious Diseases, University of Copenhagen, Copenhagen, Denmark.
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Christensen B, Nellemann B, Larsen MS, Thams L, Sieljacks P, Vestergaard PF, Bibby BM, Vissing K, Stødkilde-Jørgensen H, Pedersen SB, Møller N, Nielsen S, Jessen N, Jørgensen JOL. Whole body metabolic effects of prolonged endurance training in combination with erythropoietin treatment in humans: a randomized placebo controlled trial. Am J Physiol Endocrinol Metab 2013; 305:E879-89. [PMID: 23921143 DOI: 10.1152/ajpendo.00269.2013] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
UNLABELLED Erythropoietin (Epo) administration improves aerobic exercise capacity and insulin sensitivity in renal patients and also increases resting energy expenditure (REE). Similar effects are observed in response to endurance training. The aim was to compare the effects of endurance training with erythropoiesis-stimulating agent (ESA) treatment in healthy humans. Thirty-six healthy untrained men were randomized to 10 wk of either: 1) placebo (n = 9), 2) ESA (n = 9), 3) endurance training (n = 10), or 4) ESA and endurance training (n = 8). In a single-blinded design, ESA/placebo was injected one time weekly. Training consisted of biking for 1 h at 65% of wattmax three times per week. Measurements performed before and after the intervention were as follows: body composition, maximal oxygen uptake, insulin sensitivity, REE, and palmitate turnover. Uncoupling protein 2 (UCP2) mRNA levels were assessed in skeletal muscle. Fat mass decreased after training (P = 0.003), whereas ESA induced a small but significant increase in intrahepatic fat (P = 0.025). Serum free fatty acid (FFA) levels and palmitate turnover decreased significantly in response to training, whereas the opposite pattern was found after ESA. REE corrected for lean body mass increased in response to ESA and training, and muscle UCP2 mRNA levels increased after ESA (P = 0.035). Insulin sensitivity increased only after training (P = 0.011). IN CONCLUSION 1) insulin sensitivity is not improved after ESA treatment despite improved exercise capacity, 2) the calorigenic effects of ESA may be related to increased UCP2 gene expression in skeletal muscle, and 3) training and ESA exert opposite effects on lipolysis under basal conditions, increased FFA levels and liver fat fraction was observed after ESA treatment.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark
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Joshi D, Abraham D, Shiwen X, Baker D, Tsui J. Potential role of erythropoietin receptors and ligands in attenuating apoptosis and inflammation in critical limb ischemia. J Vasc Surg 2013; 60:191-201, 201.e1-2. [PMID: 24055514 DOI: 10.1016/j.jvs.2013.06.054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 05/23/2013] [Accepted: 06/03/2013] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Managing critical limb ischemia (CLI) is challenging. Furthermore, ischemic myopathy prevents good functional outcome after revascularization. Hence, we have focused on limiting the tissue damage rather than angiogenesis, which has traditionally been the motivation to develop nonsurgical treatments for CLI. Erythropoietin (EPO) protects ischemic tissue, and this property may also benefit CLI. The objective of this study was to examine the expression of the tissue-protective EPO receptor complex (EPOR-CD131 [β-chain of interleukin (IL)-3/IL-5/granulocyte macrophage colony-stimulating factor receptor]) in skeletal muscle obtained from humans with CLI. Because native EPO is thrombogenic, the antiapoptotic and anti-inflammatory effects of a nonhematopoietic helix-B peptide of EPO (ARA 290) were investigated on ischemic myotubes in vitro. METHODS Tissue was obtained from gastrocnemius muscle of 12 patients undergoing amputation for CLI and from 12 patients without limb ischemia. The expression of EPOR and CD131 was demonstrated by immunohistochemistry and Western blot. A validated in vitro model of myotube ischemia was used in which mature C2C12 myotubes were cultured 6 to 12 hours in a depleted media and gas mixture (20% CO2 and 80% N2). The myotubes were pretreated with EPO or ARA 290 before exposure to simulated ischemia. Apoptosis and cell death were determined by cleaved caspase-3 assay and lactate dehydrogenase release assay. Enzyme-linked immunosorbent assay measured the inflammatory cytokines. RESULTS EPOR and CD131 were expressed and significantly upregulated in CLI (average optical density [OD] in Western blot [control vs CLI] EPOR, 0.05 U vs 0.1 U; CD131, 0.10 U vs 0.22 U; P < .01). There was colocalization of EPOR and CD131 in the sarcolemma (cell membrane) of the skeletal myofiber. There was no difference in the distribution of colocalization between the CLI and the normal muscle. The ischemic myotubes treated by ARA 290 in vitro had a significantly decreased number of apoptotic cells (ischemia vs ischemia plus ARA 290: 71.1% vs 55.1%; P < .01), cleaved caspase-3 (OD of ischemia vs ischemia plus ARA 290: 0.15 U vs 0.02 U; P < .01), lactate dehydrogenase release (ischemia vs ischemia plus ARA 290: 32.5 U/L vs 21.3 U/L; P < .01), and IL-6 release (OD at 450 nm, ischemia vs ischemia plus ARA 290: 0.18 vs 0.13; P < .01). CONCLUSIONS This study demonstrates the expression and the upregulation of EPOR and CD131 in CLI and also shows that EPOR and CDI are colocalized in the cell membrane of both ischemic and control muscle fiber. The in vitro experiments demonstrate that ARA 290 decreases inflammation and apoptosis of ischemic myotubes. ARA 290 may potentially be used as adjunctive treatment for CLI.
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Affiliation(s)
- Dhiraj Joshi
- Royal Free Vascular Unit, Division of Surgery & Interventional Science, University College London, London, United Kingdom
| | - David Abraham
- Centre for Rheumatology and Connective Tissue Disease, University College London, London, United Kingdom
| | - Xu Shiwen
- Centre for Rheumatology and Connective Tissue Disease, University College London, London, United Kingdom
| | - Daryl Baker
- Royal Free Vascular Unit, Division of Surgery & Interventional Science, University College London, London, United Kingdom
| | - Janice Tsui
- Royal Free Vascular Unit, Division of Surgery & Interventional Science, University College London, London, United Kingdom.
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Lamon S, Russell AP. The role and regulation of erythropoietin (EPO) and its receptor in skeletal muscle: how much do we really know? Front Physiol 2013; 4:176. [PMID: 23874302 PMCID: PMC3710958 DOI: 10.3389/fphys.2013.00176] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 06/22/2013] [Indexed: 12/22/2022] Open
Abstract
Erythropoietin (EPO) primarily activates erythroid cell proliferation and growth and is active in several types of non-hematopoietic cells via its interaction with the EPO-receptor (EPO-R). This review focuses on the role of EPO in skeletal muscle. The EPO-R is expressed in skeletal muscle cells and EPO may promote myoblast differentiation and survival via the activation of the same signaling cascades as in hematopoietic cells, such as STAT5, MAPK and Akt. Inconsistent results exist with respect to the detection of the EPO-R mRNA and protein in muscle cells, tissue and across species and the use of non-specific EPO-R antibodies contributes to this problem. Additionally, the inability to reproducibly detect an activation of the known EPO-induced signaling pathways in skeletal muscle questions the functionality of the EPO-R in muscle in vivo. These equivocal findings make it difficult to distinguish between a direct effect of EPO on skeletal muscle, via the activation of its receptor, and an indirect effect resulting from a better oxygen supply to the muscle. Consequently, the precise role of EPO in skeletal muscle and its regulatory mechanism/s remain to be elucidated. Further studies are required to comprehensively establish the importance of EPO and its function in skeletal muscle health.
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Affiliation(s)
- Séverine Lamon
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University Burwood, VIC, Australia
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Rundqvist H, Augsten M, Strömberg A, Rullman E, Mijwel S, Kharaziha P, Panaretakis T, Gustafsson T, Östman A. Effect of acute exercise on prostate cancer cell growth. PLoS One 2013; 8:e67579. [PMID: 23861774 PMCID: PMC3702495 DOI: 10.1371/journal.pone.0067579] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 05/23/2013] [Indexed: 11/18/2022] Open
Abstract
Physical activity is associated with reduced risk of several cancers, including aggressive prostate cancer. The mechanisms mediating the effects are not yet understood; among the candidates are modifications of endogenous hormone levels. Long-term exercise is known to reduce serum levels of growth stimulating hormones. In contrast, the endocrine effects of acute endurance exercise include increased levels of mitogenic factors such as GH and IGF-1. It can be speculated that the elevation of serum growth factors may be detrimental to prostate cancer progression into malignancy. The incentive of the current study is to evaluate the effect of acute exercise serum on prostate cancer cell growth. We designed an exercise intervention where 10 male individuals performed 60 minutes of bicycle exercise at increasing intensity. Serum samples were obtained before (rest serum) and after completed exercise (exercise serum). The established prostate cancer cell line LNCaP was exposed to exercise or rest serum. Exercise serum from 9 out of 10 individuals had a growth inhibitory effect on LNCaP cells. Incubation with pooled exercise serum resulted in a 31% inhibition of LNCaP growth and pre-incubation before subcutaneous injection into SCID mice caused a delay in tumor formation. Serum analyses indicated two possible candidates for the effect; increased levels of IGFBP-1 and reduced levels of EGF. In conclusion, despite the fear of possible detrimental effects of acute exercise serum on tumor cell growth, we show that even the short-term effects seem to add to the overall beneficial influence of exercise on neoplasia.
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Affiliation(s)
- Helene Rundqvist
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden.
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The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection. Kidney Int 2013; 84:468-81. [PMID: 23636173 PMCID: PMC3758776 DOI: 10.1038/ki.2013.149] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 02/11/2013] [Accepted: 02/14/2013] [Indexed: 12/22/2022]
Abstract
Although the role of the erythropoietin (EPO) receptor (EpoR) in erythropoiesis has been known for decades, its role in nonhematopoietic tissues is still not well defined. Klotho has been shown and EPo has been suggested to protect against acute ischemia-reperfusion injury in the kidney. Here we found in rat kidney and in a rat renal tubular epithelial cell line (NRK cells) EpoR transcript and antigen, and EpoR activity signified as EPo-induced phosphorylation of Jak2, ErK, Akt, and Stat5 indicating the presence of functional EpoR. Transgenic overexpression of Klotho or addition of exogenous recombinant Klotho increased kidney EpoR protein and transcript. In NRK cells, Klotho increased EpoR protein, enhanced EPo-triggered phosphorylation of Jak2 and Stat5, the nuclear translocation of phospho-Stat5, and protected NRK cells from hydrogen peroxide cytotoxicity. Knockdown of endogenous EpoR rendered NRK cells more vulnerable, and overexpression of EpoR more resistant to peroxide-induced cytotoxicity, indicating that EpoR mitigates oxidative damage. Knockdown of EpoR by siRNA abolished Epo-induced Jak2, and Stat5 phosphorylation, and blunted the protective effect of Klotho against peroxide-induced cytotoxicity. Thus in the kidney, EpoR and its activity are downstream effectors of Klotho enabling it to function as a cytoprotective protein against oxidative injury.
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Pan Y, Shu JL, Gu HF, Zhou DC, Liu XL, Qiao QY, Fu SK, Gao FH, Jin HM. Erythropoietin improves insulin resistance via the regulation of its receptor-mediated signaling pathways in 3T3L1 adipocytes. Mol Cell Endocrinol 2013; 367:116-23. [PMID: 23313788 DOI: 10.1016/j.mce.2012.12.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 11/26/2012] [Accepted: 12/21/2012] [Indexed: 12/24/2022]
Abstract
Recombinant human erythropoietin (rHuEPO) reduces serum insulin levels, increases insulin sensitivity, and reduces insulin resistance (IR). However, the mechanisms behind these effects are unclear. This study aimed to investigate the mechanism by which rHuEPO effects IR in 3T3L1 adipocytes. After treatment with different concentrations of rHuEPO, glucose consumption, and tumor necrosis factor (TNF-α), adiponectin, and leptin levels were assayed with a commercial enzyme-linked immunosorbent assays. Endogenous erythropoietin receptor (EPOR) expression was inhibited using small interfering RNA (siRNA). EPOR protein and mRNA expression was detected via immunofluorescence and real-time PCR analyses, respectively. The expression of pAKT/AKT and p-STAT5/STAT5 was determined via Western blot analysis. rHuEPO treatment improved glucose uptake, increased adiponectin levels, and reduced TNF-α and leptin levels in 3T3L1 adipocytes with dexamethasone-induced IR. Whereas EPOR protein and gene expression was absent in preadipocytes, it was observed in mature 3T3L1 adipocytes. However, the expression of EPOR in insulin resistant 3T3L1 adipocytes was significantly decreased (p<0.05). rHuEPO increased the expression of EPOR, and upregulated the expression of pAKT/AKT and pSTAT5/STAT5 in 3T3L1 adipocytes (p<0.05), which was blocked by siEPOR, the phosphatidylinositol-3-kinase (PI3K) inhibitor, LY294002, and a STAT5 inhibitor, respectively. In summary, rHuEPO reduced IR in adipocytes by increasing glucose uptake and improving the adipokine profile. rHuEPO-induced EPOR protein expression and subsequent induction of pAKT and pSTAT5 suggest that the EPO-EPOR system may play a role in glucose metabolism within adipocytes.
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Affiliation(s)
- Yu Pan
- Division of Nephrology, No. 3 People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Cardiac molecular-acclimation mechanisms in response to swimming-induced exercise in Atlantic salmon. PLoS One 2013; 8:e55056. [PMID: 23372811 PMCID: PMC3555865 DOI: 10.1371/journal.pone.0055056] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 12/19/2012] [Indexed: 12/05/2022] Open
Abstract
Cardiac muscle is a principal target organ for exercise-induced acclimation mechanisms in fish and mammals, given that sustained aerobic exercise training improves cardiac output. Yet, the molecular mechanisms underlying such cardiac acclimation have been scarcely investigated in teleosts. Consequently, we studied mechanisms related to cardiac growth, contractility, vascularization, energy metabolism and myokine production in Atlantic salmon pre-smolts resulting from 10 weeks exercise-training at three different swimming intensities: 0.32 (control), 0.65 (medium intensity) and 1.31 (high intensity) body lengths s−1. Cardiac responses were characterized using growth, immunofluorescence and qPCR analysis of a large number of target genes encoding proteins with significant and well-characterized function. The overall stimulatory effect of exercise on cardiac muscle was dependent on training intensity, with changes elicited by high intensity training being of greater magnitude than either medium intensity or control. Higher protein levels of PCNA were indicative of cardiac growth being driven by cardiomyocyte hyperplasia, while elevated cardiac mRNA levels of MEF2C, GATA4 and ACTA1 suggested cardiomyocyte hypertrophy. In addition, up-regulation of EC coupling-related genes suggested that exercised hearts may have improved contractile function, while higher mRNA levels of EPO and VEGF were suggestive of a more efficient oxygen supply network. Furthermore, higher mRNA levels of PPARα, PGC1α and CPT1 all suggested a higher capacity for lipid oxidation, which along with a significant enlargement of mitochondrial size in cardiac myocytes of the compact layer of fish exercised at high intensity, suggested an enhanced energetic support system. Training also elevated transcription of a set of myokines and other gene products related to the inflammatory process, such as TNFα, NFκB, COX2, IL1RA and TNF decoy receptor. This study provides the first characterization of the underlying molecular acclimation mechanisms in the heart of exercise-trained fish, which resemble those reported for mammalian physiological cardiac growth.
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Abstract
Peripheral arterial disease (PAD) is a common vascular disease that reduces blood flow capacity to the legs of patients. PAD leads to exercise intolerance that can progress in severity to greatly limit mobility, and in advanced cases leads to frank ischemia with pain at rest. It is estimated that 12 to 15 million people in the United States are diagnosed with PAD, with a much larger population that is undiagnosed. The presence of PAD predicts a 50% to 1500% increase in morbidity and mortality, depending on severity. Treatment of patients with PAD is limited to modification of cardiovascular disease risk factors, pharmacological intervention, surgery, and exercise therapy. Extended exercise programs that involve walking approximately five times per week, at a significant intensity that requires frequent rest periods, are most significant. Preclinical studies and virtually all clinical trials demonstrate the benefits of exercise therapy, including improved walking tolerance, modified inflammatory/hemostatic markers, enhanced vasoresponsiveness, adaptations within the limb (angiogenesis, arteriogenesis, and mitochondrial synthesis) that enhance oxygen delivery and metabolic responses, potentially delayed progression of the disease, enhanced quality of life indices, and extended longevity. A synthesis is provided as to how these adaptations can develop in the context of our current state of knowledge and events known to be orchestrated by exercise. The benefits are so compelling that exercise prescription should be an essential option presented to patients with PAD in the absence of contraindications. Obviously, selecting for a lifestyle pattern that includes enhanced physical activity prior to the advance of PAD limitations is the most desirable and beneficial.
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Affiliation(s)
- Tara L Haas
- Angiogenesis Research Group, Muscle Health Research Centre, Faculty of Health, York University, Toronto, Ontario, Canada
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Mille-Hamard L, Billat VL, Henry E, Bonnamy B, Joly F, Benech P, Barrey E. Skeletal muscle alterations and exercise performance decrease in erythropoietin-deficient mice: a comparative study. BMC Med Genomics 2012; 5:29. [PMID: 22748015 PMCID: PMC3473259 DOI: 10.1186/1755-8794-5-29] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 06/21/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Erythropoietin (EPO) is known to improve exercise performance by increasing oxygen blood transport and thus inducing a higher maximum oxygen uptake (VO2max). Furthermore, treatment with (or overexpression of) EPO induces protective effects in several tissues, including the myocardium. However, it is not known whether EPO exerts this protective effect when present at physiological levels. Given that EPO receptors have been identified in skeletal muscle, we hypothesized that EPO may have a direct, protective effect on this tissue. Thus, the objectives of the present study were to confirm a decrease in exercise performance and highlight muscle transcriptome alterations in a murine EPO functional knock-out model (the EPO-d mouse). METHODS We determined VO2max peak velocity and critical speed in exhaustive runs in 17 mice (9 EPO-d animals and 8 inbred controls), using treadmill enclosed in a metabolic chamber. Mice were sacrificed 24h after a last exhaustive treadmill exercise at critical speed. The tibialis anterior and soleus muscles were removed and total RNA was extracted for microarray gene expression analysis. RESULTS The EPO-d mice's hematocrit was about 50% lower than that of controls (p<0.05) and their performance level was about 25% lower (p<0.001). A total of 1583 genes exhibited significant changes in their expression levels. However, 68 genes were strongly up-regulated (normalized ratio>1.4) and 115 were strongly down-regulated (normalized ratio<0.80). The transcriptome data mining analysis showed that the exercise in the EPO-d mice induced muscle hypoxia, oxidative stress and proteolysis associated with energy pathway disruptions in glycolysis and mitochondrial oxidative phosphorylation. CONCLUSIONS Our results showed that the lack of functional EPO induced a decrease in the aerobic exercise capacity. This decrease was correlated with the hematocrit and reflecting poor oxygen supply to the muscles. The observed alterations in the muscle transcriptome suggest that physiological concentrations of EPO exert both direct and indirect muscle-protecting effects during exercise. However, the signaling pathway involved in these protective effects remains to be described in detail.
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Affiliation(s)
- Laurence Mille-Hamard
- Unité de Biologie Intégrative des Adaptations à l'Exercice - INSERM 902, Genopole, F-91058, Evry, France.
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Three weeks of erythropoietin treatment hampers skeletal muscle mitochondrial biogenesis in rats. J Physiol Biochem 2012; 68:593-601. [PMID: 22627788 DOI: 10.1007/s13105-012-0178-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Accepted: 05/10/2012] [Indexed: 12/23/2022]
Abstract
The blood O(2)-carrying capacity is maintained by the O(2)-regulated production of erythropoietin (Epo), which stimulates the proliferation and survival of red blood cell progenitors. Epo has been thought to act exclusively on erythroid progenitor cells. However, recent studies have identified the erythropoietin receptor (EpoR) in other cells, such as neurons, astrocytes, microglia, heart, cancer cell lines, and skeletal muscle provides evidence for a potential role of Epo in other tissues. In this study we aimed to determine the effect of recombinant human erythropoietin (rHuEpo) on skeletal muscle adaptations such as mitochondrial biogenesis, myogenesis, and angiogenesis in different muscle fibre types. Fourteen male Wistar rats were randomly divided into two experimental groups, and saline or rHuEpo (300 IU) was administered subcutaneously three times a week for 3 weeks. We evaluated the protein expression of intermediates involved in the mitochondrial biogenesis cascade, the myogenic cascade, and in angiogenesis in the oxidative soleus muscle and in the glycolytic gastrocnemius muscle. Contrary to our expectations, rHuEpo significantly hampered the mitochondrial biogenesis pathway in gastrocnemius muscle (PGC-1α, mTFA and cytochrome c). We did not find any effect of the treatment on cellular signals of myogenesis (MyoD and Myf5) or angiogenesis (VEGF) in either soleus or gastrocnemius muscles. Finally, we found no significant effect on the maximal aerobic velocity at the end of the experiment in the rHuEpo-treated animals. Our findings suggest that 3 weeks of rHuEpo treatment, which generates an increase of oxygen carrying capacity, can affect mitochondrial biogenesis in a muscle fibre-specific dependent manner.
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Jia Y, Suzuki N, Yamamoto M, Gassmann M, Noguchi CT. Endogenous erythropoietin signaling facilitates skeletal muscle repair and recovery following pharmacologically induced damage. FASEB J 2012; 26:2847-58. [PMID: 22490927 DOI: 10.1096/fj.11-196618] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Erythropoietin acts by binding to its cell surface receptor on erythroid progenitor cells to stimulate erythrocyte production. Erythropoietin receptor expression in nonhematopoietic tissue, including skeletal muscle progenitor cells, raises the possibility of a role for erythropoietin beyond erythropoiesis. Mice with erythropoietin receptor restricted to hematopoietic tissue were used to assess contributions of endogenous erythropoietin to promote skeletal myoblast proliferation and survival and wound healing in a mouse model of cardiotoxin induced muscle injury. Compared with wild-type controls, these mice had fewer skeletal muscle Pax-7(+) satellite cells and myoblasts that do not proliferate in culture, were more susceptible to skeletal muscle injury and reduced maximum load tolerated by isolated muscle. In contrast, mice with chronic elevated circulating erythropoietin had more Pax-7(+) satellite cells and myoblasts with increased proliferation and survival in culture, decreased muscle injury, and accelerated recovery of maximum load tolerated by isolated muscle. Skeletal muscle myoblasts also produced endogenous erythropoietin that increased at low O(2). Erythropoietin promoted proliferation, survival, and wound recovery in myoblasts via the phosphoinositide 3-kinase/AKT pathway. Therefore, endogenous and exogenous erythropoietin contribute to increasing satellite cell number following muscle injury, improve myoblast proliferation and survival, and promote repair and regeneration in this mouse induced muscle injury model independent of its effect on erythrocyte production.
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Affiliation(s)
- Yi Jia
- Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-1822, USA
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Plenge U, Belhage B, Guadalupe-Grau A, Andersen PR, Lundby C, Dela F, Stride N, Pott FC, Helge JW, Boushel R. Erythropoietin treatment enhances muscle mitochondrial capacity in humans. Front Physiol 2012; 3:50. [PMID: 22419911 PMCID: PMC3299978 DOI: 10.3389/fphys.2012.00050] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 02/23/2012] [Indexed: 11/13/2022] Open
Abstract
Erythropoietin (Epo) treatment has been shown to induce mitochondrial biogenesis in cardiac muscle along with enhanced mitochondrial capacity in mice. We hypothesized that recombinant human Epo (rhEpo) treatment enhances skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity in humans. In six healthy volunteers rhEpo was administered by sub-cutaneous injection over 8 weeks with oral iron (100 mg) supplementation taken daily. Mitochondrial OXPHOS was quantified by high-resolution respirometry in saponin-permeabilized muscle fibers obtained from biopsies of the vastus lateralis before and after rhEpo treatment. OXPHOS was determined with the mitochondrial complex I substrates malate, glutamate, pyruvate, and complex II substrate succinate in the presence of saturating ADP concentrations, while maximal electron transport capacity (ETS) was assessed by addition of an uncoupler. rhEpo treatment increased OXPHOS (from 92 ± 5 to 113 ± 7 pmol·s−1·mg−1) and ETS (107 ± 4 to 143 ± 14 pmol·s−1·mg−1, p < 0.05), demonstrating that Epo treatment induces an upregulation of OXPHOS and ETS in human skeletal muscle.
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Affiliation(s)
- Ulla Plenge
- Department of Anaesthesia, Bispebjerg Hospital Copenhagen, Denmark
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Christensen B, Lundby C, Jessen N, Nielsen TS, Vestergaard PF, Møller N, Pilegaard H, Pedersen SB, Kopchick JJ, Jørgensen JOL. Evaluation of functional erythropoietin receptor status in skeletal muscle in vivo: acute and prolonged studies in healthy human subjects. PLoS One 2012; 7:e31857. [PMID: 22384088 PMCID: PMC3285196 DOI: 10.1371/journal.pone.0031857] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 01/18/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Erythropoietin receptors have been identified in human skeletal muscle tissue, but downstream signal transduction has not been investigated. We therefore studied in vivo effects of systemic erythropoietin exposure in human skeletal muscle. METHODOLOGY/PRINCIPAL FINDINGS The protocols involved 1) acute effects of a single bolus injection of erythropoietin followed by consecutive muscle biopsies for 1-10 hours, and 2) a separate study with prolonged administration for 16 days with biopsies obtained before and after. The presence of erythropoietin receptors in muscle tissue as well as activation of Epo signalling pathways (STAT5, MAPK, Akt, IKK) were analysed by western blotting. Changes in muscle protein profiles after prolonged erythropoietin treatment were evaluated by 2D gel-electrophoresis and mass spectrometry. The presence of the erythropoietin receptor in skeletal muscle was confirmed, by the M20 but not the C20 antibody. However, no significant changes in phosphorylation of the Epo-R, STAT5, MAPK, Akt, Lyn, IKK, and p70S6K after erythropoietin administration were detected. The level of 8 protein spots were significantly altered after 16 days of rHuEpo treatment; one isoform of myosin light chain 3 and one of desmin/actin were decreased, while three isoforms of creatine kinase and two of glyceraldehyd-3-phosphate dehydrogenase were increased. CONCLUSIONS/SIGNIFICANCE Acute exposure to recombinant human erythropoietin is not associated by detectable activation of the Epo-R or downstream signalling targets in human skeletal muscle in the resting situation, whereas more prolonged exposure induces significant changes in the skeletal muscle proteome. The absence of functional Epo receptor activity in human skeletal muscle indicates that the long-term effects are indirect and probably related to an increased oxidative capacity in this tissue.
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Affiliation(s)
- Britt Christensen
- Department of Endocrinology and Internal Medicine, NBG/THG, Aarhus University Hospital, Aarhus, Denmark.
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Li R, Yuan L, Wang J, Wang J. Co-expression of erythropoietin receptor with human epidermal growth factor 2 may counteract trastuzumab inhibition in gastric cancer. Med Hypotheses 2011; 77:948-52. [PMID: 21944379 DOI: 10.1016/j.mehy.2011.07.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Accepted: 07/07/2011] [Indexed: 02/06/2023]
Abstract
Gastric cancer has high prevalence and high modality worldwide. For many years, few improvements in the efficacy of treatments were reported for advanced gastric cancer settings. Although a novel molecular target agent trastuzumab, in combination with chemotherapy, prolongs overall survival time in advanced gastric cancer, resistance to this drug still exists among human epidermal growth factor receptor-2 (HER2) positive patients. HER2 and erythropoietin receptor (EPOR) downstream signaling pathway have some common factors like Akt, Erk and STATs. Also there exist evidences that EPOR may express on some solid tumors and probably promote tumor progression. So it is reasonable for us to hypothesis that HER2 and EPOR may be co-expressed in the same gastric cancer cell and if so, EPOR signaling pathway may overlaps that with HER2 and promotes HER2 induced signal transduction to cell proliferation. In clinical settings, a stimulation of EPOR will play antagonistic effects on trastuzumab-induced anti-tumor activity to HER2-positive gastric cancer patients. Co-expression of EPOR and HER2 is a predictive factor for resistance of trastuzumab in gastric cancer.
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Affiliation(s)
- Rui Li
- Department of Medical Oncology, Changzheng Hospital, The Second Military Medical University, No 64, Hetian Road, Shanghai 200070, China.
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48
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Baker JM, De Lisio M, Parise G. Endurance exercise training promotes medullary hematopoiesis. FASEB J 2011; 25:4348-57. [PMID: 21868472 DOI: 10.1096/fj.11-189043] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Endurance exercise is a poorly defined yet powerful mediator of hematopoiesis. The purpose of this study was to directly investigate the effects of endurance exercise training on hematopoiesis and to identify potential mechanisms responsible for any observed changes. Four-week-old male C57Bl/6 mice were trained on a treadmill at progressive speeds over a 10-wk period. Tissues were harvested 2 d following the final training session. Flow cytometry, the cobblestone area-forming cell assay, and the methycellulose colony-forming unit assay were used to assess medullary and mobilized hematopoietic stem and progenitor cells. Quantitative real-time PCR and Western blots were used to measure hematopoietic cytokine production. Histochemistry was also used to assess adaptations to exercise in the bone marrow niche. Depending on the cell type, endurance training increased medullary and mobilized hematopoietic stem and progenitor cell content from 50 to 800%. Training also reduced marrow cavity fat by 78%. Skeletal muscle hematopoietic cytokine expression was also increased at least 60% by training. Sedentary mice served as controls for the above experiments. In conclusion, endurance exercise training greatly promotes hematopoiesis and does so through improvements in medullary niche architecture as well as increased skeletal muscle hematopoietic cytokine production.
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Affiliation(s)
- J M Baker
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
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49
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Nikolopoulos DD, Spiliopoulou C, Theocharis SE. Doping and musculoskeletal system: short-term and long-lasting effects of doping agents. Fundam Clin Pharmacol 2010; 25:535-63. [PMID: 21039821 DOI: 10.1111/j.1472-8206.2010.00881.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Doping is a problem that has plagued the world of competition and sports for ages. Even before the dawn of Olympic history in ancient Greece, competitors have looked for artificial means to improve athletic performance. Since ancient times, athletes have attempted to gain an unfair competitive advantage through the use of doping substances. A Prohibited List of doping substances and methods banned in sports is published yearly by the World Anti-Doping Agency. Among the substances included are steroidal and peptide hormones and their modulators, stimulants, glucocorticosteroids, β₂-agonists, diuretics and masking agents, narcotics, and cannabinoids. Blood doping, tampering, infusions, and gene doping are examples of prohibited methods indicated on the List. Apart from the unethical aspect of doping, as it abrogates fair-play's principle, it is extremely important to consider the hazards it presents to the health and well-being of athletes. The referred negative effects for the athlete's health have to do, on the one hand, by the high doses of the performance-enhancing agents and on the other hand, by the relentless, superhuman strict training that the elite or amateur athletes put their muscles, bones, and joints. The purpose of this article is to highlight the early and the long-lasting consequences of the doping abuse on bone and muscle metabolism.
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Affiliation(s)
- Dimitrios D Nikolopoulos
- Department of Forensic Medicine and Toxicology University of Athens, Medical School, Athens, Greece
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Abstract
This review describes some of the physiological effects of recombinant human erythropoietin (EPO) in healthy humans. At the blood level EPO increases the arterial O(2) content not only by increasing red blood cell volume, but also by an equally important decrease in plasma volume. Well before that, EPO causes a prompt decrease in plasma levels of renin and aldosterone. Renal clearance studies suggest that EPO decreases renal proximal tubular reabsorption rate leading to activation of the tubuloglomerular feedback mechanism and a fall in glomerular filtration rate. Thus, treatment with EPO may result in suppression of endogenous EPO production through a decrease in intrarenal oxygen consumption. EPO elevates the arterial blood pressure even in healthy subjects. The receptor for EPO is present in many tissues. However, the functional effects of EPO in the skeletal muscle seem limited, and although it has been speculated that non-erythropoietic effects of EPO (angiogenesis, shift in muscle fibre types, cognitive effects) may be responsible for the increase in exercise performance, this has not been confirmed. EPO-induced haemodynamic effects call for careful monitoring during the administration period. The metabolic, hormonal and renal effects of EPO do not seem to range beyond physiologically acceptable limits and are reversible. Taken together, EPO seems safe to use for experimental purposes in healthy volunteers.
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Affiliation(s)
- Carsten Lundby
- Center for Integrative Human Physiology, University of Zurich, Institute of Physiology, Room 23 H 6, Winterthurerstr. 190, 8057 Zürich, Switzerland.
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