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Zhao LH, Lin J, Ji SY, Zhou XE, Mao C, Shen DD, He X, Xiao P, Sun J, Melcher K, Zhang Y, Yu X, Xu HE. Structure insights into selective coupling of G protein subtypes by a class B G protein-coupled receptor. Nat Commun 2022; 13:6670. [PMID: 36335102 PMCID: PMC9637140 DOI: 10.1038/s41467-022-33851-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 10/05/2022] [Indexed: 11/07/2022] Open
Abstract
The ability to couple with multiple G protein subtypes, such as Gs, Gi/o, or Gq/11, by a given G protein-coupled receptor (GPCR) is critical for many physiological processes. Over the past few years, the cryo-EM structures for all 15 members of the medically important class B GPCRs, all in complex with Gs protein, have been determined. However, no structure of class B GPCRs with Gq/11 has been solved to date, limiting our understanding of the precise mechanisms of G protein coupling selectivity. Here we report the structures of corticotropin releasing factor receptor 2 (CRF2R) bound to Urocortin 1 (UCN1), coupled with different classes of heterotrimeric G proteins, G11 and Go. We compare these structures with the structure of CRF2R in complex with Gs to uncover the structural differences that determine the selective coupling of G protein subtypes by CRF2R. These results provide important insights into the structural basis for the ability of CRF2R to couple with multiple G protein subtypes.
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Affiliation(s)
- Li-Hua Zhao
- grid.9227.e0000000119573309The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jingyu Lin
- grid.27255.370000 0004 1761 1174Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, 250012 China
| | - Su-Yu Ji
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058 China
| | - X. Edward Zhou
- grid.251017.00000 0004 0406 2057Department of Structural Biology, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Chunyou Mao
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058 China
| | - Dan-Dan Shen
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058 China
| | - Xinheng He
- grid.9227.e0000000119573309The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Peng Xiao
- grid.27255.370000 0004 1761 1174Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, 250012 China
| | - Jinpeng Sun
- grid.27255.370000 0004 1761 1174Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, 250012 China
| | - Karsten Melcher
- grid.251017.00000 0004 0406 2057Department of Structural Biology, Van Andel Research Institute, Grand Rapids, MI 49503 USA
| | - Yan Zhang
- grid.13402.340000 0004 1759 700XDepartment of Biophysics and Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310058 China ,grid.13402.340000 0004 1759 700XLiangzhu Laboratory, Zhejiang University Medical Center, Hangzhou, 311121 China ,grid.13402.340000 0004 1759 700XMOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Medicine, Hangzhou, 310058 China ,Zhejiang Provincial Key Laboratory of Immunity and Inflammatory diseases, Hangzhou, 310058 China
| | - Xiao Yu
- grid.27255.370000 0004 1761 1174Department of Physiology, School of Basic Medical Sciences, Shandong University, Jinan, 250012 China
| | - H. Eric Xu
- grid.9227.e0000000119573309The CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203 China ,grid.410726.60000 0004 1797 8419University of Chinese Academy of Sciences, Beijing, 100049 China
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Lautherbach N, Gonçalves DAP, Silveira WA, Paula-Gomes S, Valentim RR, Zanon NM, Pereira MG, Miyabara EH, Navegantes LCC, Kettelhut IC. Urocortin 2 promotes hypertrophy and enhances skeletal muscle function through cAMP and insulin/IGF-1 signaling pathways. Mol Metab 2022; 60:101492. [PMID: 35390501 PMCID: PMC9035725 DOI: 10.1016/j.molmet.2022.101492] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 02/27/2022] [Accepted: 03/29/2022] [Indexed: 11/28/2022] Open
Abstract
Objective Although it is well established that urocortin 2 (Ucn2), a peptide member of the corticotrophin releasing factor (CRF) family, and its specific corticotrophin-releasing factor 2 receptor (CRF2R) are highly expressed in skeletal muscle, the role of this peptide in the regulation of skeletal muscle mass and protein metabolism remains elusive. Methods To elucidate the mechanisms how Ucn2 directly controls protein metabolism in skeletal muscles of normal mice, we carried out genetic tools, physiological and molecular analyses of muscles in vivo and in vitro. Results Here, we demonstrated that Ucn2 overexpression activated cAMP signaling and promoted an expressive muscle hypertrophy associated with higher rates of protein synthesis and activation of Akt/mTOR and ERK1/2 signaling pathways. Furthermore, Ucn2 induced a decrease in mRNA levels of atrogin-1 and in autophagic flux inferred by an increase in the protein content of LC3-I, LC3-II and p62. Accordingly, Ucn2 reduced both the transcriptional activity of FoxO in vivo and the overall protein degradation in vitro through an inhibition of lysosomal proteolytic activity. In addition, we demonstrated that Ucn2 induced a fast-to-slow fiber type shift and improved fatigue muscle resistance, an effect that was completely blocked in muscles co-transfected with mitogen-activated protein kinase phosphatase 1 (MKP-1), but not with dominant-negative Akt mutant (Aktmt). Conclusions These data suggest that Ucn2 triggers an anabolic and anti-catabolic response in skeletal muscle of normal mice probably through the activation of cAMP cascade and participation of Akt and ERK1/2 signaling. These findings open new perspectives in the development of therapeutic strategies to cope with the loss of muscle mass. Ucn2 overexpression promotes muscle growth due to an increase in protein synthesis. Ucn2 inhibits FoxO activity and autophagic-lysosomal system. Ucn2-induced skeletal muscle phenotype is dependent on Akt and ERK1/2. Ucn2 induces a fast-to-slow fiber type shift and improves fatigue resistance. The increase in muscle fatigue resistance is dependent on ERK1/2.
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Affiliation(s)
- Natalia Lautherbach
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biochemistry/Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Dawit A P Gonçalves
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Physical Education, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
| | - Wilian A Silveira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biochemistry, Pharmacology and Physiology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil.
| | - Sílvia Paula-Gomes
- Department of Biochemistry/Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biological Sciences, Institute of Exact and Biological Sciences, Federal University of Ouro Preto, Ouro Preto, MG, Brazil.
| | - Rafael Rossi Valentim
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Neuza M Zanon
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Marcelo G Pereira
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Elen H Miyabara
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
| | - Luiz C C Navegantes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
| | - Isis C Kettelhut
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil; Department of Biochemistry/Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
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3
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Borg ML, Massart J, De Castro Barbosa T, Archilla-Ortega A, Smith JAB, Lanner JT, Alsina-Fernandez J, Yaden B, Culver AE, Karlsson HKR, Brozinick JT, Zierath JR. Modified UCN2 peptide treatment improves skeletal muscle mass and function in mouse models of obesity-induced insulin resistance. J Cachexia Sarcopenia Muscle 2021; 12:1232-1248. [PMID: 34342159 PMCID: PMC8517345 DOI: 10.1002/jcsm.12746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/25/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Type 2 diabetes and obesity are often seen concurrently with skeletal muscle wasting, leading to further derangements in function and metabolism. Muscle wasting remains an unmet need for metabolic disease, and new approaches are warranted. The neuropeptide urocortin 2 (UCN2) and its receptor corticotropin releasing factor receptor 2 (CRHR2) are highly expressed in skeletal muscle and play a role in regulating energy balance, glucose metabolism, and muscle mass. The aim of this study was to investigate the effects of modified UCN2 peptides as a pharmaceutical therapy to counteract the loss of skeletal muscle mass associated with obesity and casting immobilization. METHODS High-fat-fed mice (C57Bl/6J; 26 weeks old) and ob/ob mice (11 weeks old) were injected daily with a PEGylated (Compound A) and non-PEGylated (Compound B) modified human UCN2 at 0.3 mg/kg subcutaneously for 14 days. A separate group of chow-fed C57Bl/6J mice (12 weeks old) was subjected to hindlimb cast immobilization and, after 1 week, received daily injections with Compound A. In vivo functional tests were performed to measure protein synthesis rates and skeletal muscle function. Ex vivo functional and molecular tests were performed to measure contractile force and signal transduction of catabolic and anabolic pathways in skeletal muscle. RESULTS Skeletal muscles (extensor digitorum longus, soleus, and tibialis anterior) from high-fat-fed mice treated with Compound A were ~14% heavier than muscles from vehicle-treated mice. Chronic treatment with modified UCN2 peptides altered the expression of structural genes and transcription factors in skeletal muscle in high-fat diet-induced obesity including down-regulation of Trim63 and up-regulation of Nr4a2 and Igf1 (P < 0.05 vs. vehicle). Signal transduction via both catabolic and anabolic pathways was increased in tibialis anterior muscle, with increased phosphorylation of ribosomal protein S6 at Ser235/236 , FOXO1 at Ser256 , and ULK1 at Ser317 , suggesting that UCN2 treatment modulates protein synthesis and degradation pathways (P < 0.05 vs. vehicle). Acutely, a single injection of Compound A in drug-naïve mice had no effect on the rate of protein synthesis in skeletal muscle, as measured via the surface sensing of translation method, while the expression of Nr4a3 and Ppargc1a4 was increased (P < 0.05 vs. vehicle). Compound A treatment prevented the loss of force production from disuse due to casting. Compound B treatment increased time to fatigue during ex vivo contractions of fast-twitch extensor digitorum longus muscle. Compound A and B treatment increased lean mass and rates of skeletal muscle protein synthesis in ob/ob mice. CONCLUSIONS Modified human UCN2 is a pharmacological candidate for the prevention of the loss of skeletal muscle mass associated with obesity and immobilization.
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Affiliation(s)
- Melissa L Borg
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Julie Massart
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Thais De Castro Barbosa
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Adrià Archilla-Ortega
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Jonathon A B Smith
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Section for Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | | | - Benjamin Yaden
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Alexander E Culver
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Håkan K R Karlsson
- Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Joseph T Brozinick
- Lilly Research Laboratories, Division of Eli Lilly and Company, Indianapolis, IN, USA
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
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Berdeaux R, Hutchins C. Anabolic and Pro-metabolic Functions of CREB-CRTC in Skeletal Muscle: Advantages and Obstacles for Type 2 Diabetes and Cancer Cachexia. Front Endocrinol (Lausanne) 2019; 10:535. [PMID: 31428057 PMCID: PMC6688074 DOI: 10.3389/fendo.2019.00535] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/18/2019] [Indexed: 12/31/2022] Open
Abstract
cAMP is one of the earliest described mediators of hormone action in response to physiologic stress that allows acute stress responses and adaptation in every tissue. The classic role of cAMP signaling in metabolic tissues is to regulate nutrient partitioning. In response to acute stress, such as epinephrine released during strenuous exercise or fasting, intramuscular cAMP liberates glucose from glycogen and fatty acids from triglycerides. In the long-term, activation of Gs-coupled GPCRs stimulates muscle growth (hypertrophy) and metabolic adaptation through multiple pathways that culminate in a net increase of protein synthesis, mitochondrial biogenesis, and improved metabolic efficiency. This review focuses on regulation, function, and transcriptional targets of CREB (cAMP response element binding protein) and CRTCs (CREB regulated transcriptional coactivators) in skeletal muscle and the potential for targeting this pathway to sustain muscle mass and metabolic function in type 2 diabetes and cancer. Although the muscle-autonomous roles of these proteins might render them excellent targets for both conditions, pharmacologic targeting must be approached with caution. Gain of CREB-CRTC function is associated with excess liver glucose output in type 2 diabetes, and growing evidence implicates CREB-CRTC activation in proliferation and invasion of different types of cancer cells. We conclude that deeper investigation to identify skeletal muscle specific regulatory mechanisms that govern CREB-CRTC transcriptional activity is needed to safely take advantage of their potent effects to invigorate skeletal muscle to potentially improve health in people with type 2 diabetes and cancer.
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Affiliation(s)
- Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, Center for Metabolic and Degenerative Diseases, The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, United States
- Graduate Program in Biochemistry and Cell Biology, The MD Anderson-UTHealth Graduate School of Biomedical Sciences, Houston, TX, United States
- *Correspondence: Rebecca Berdeaux
| | - Chase Hutchins
- Department of Integrative Biology and Pharmacology, Center for Metabolic and Degenerative Diseases, The Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, United States
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Burns DP, Canavan L, Rowland J, O'Flaherty R, Brannock M, Drummond SE, O'Malley D, Edge D, O'Halloran KD. Recovery of respiratory function in mdx mice co-treated with neutralizing interleukin-6 receptor antibodies and urocortin-2. J Physiol 2018; 596:5175-5197. [PMID: 30160301 PMCID: PMC6209753 DOI: 10.1113/jp276954] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 08/22/2018] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Impaired ventilatory capacity and diaphragm muscle weakness are prominent features of Duchenne muscular dystrophy, with strong evidence of attendant systemic and muscle inflammation. We performed a 2-week intervention in young wild-type and mdx mice, consisting of either injection of saline or co-administration of a neutralizing interleukin-6 receptor antibody (xIL-6R) and urocortin-2 (Ucn2), a corticotrophin releasing factor receptor 2 agonist. We examined breathing and diaphragm muscle form and function. Breathing and diaphragm muscle functional deficits are improved following xIL-6R and Ucn2 co-treatment in mdx mice. The functional improvements were associated with a preservation of mdx diaphragm muscle myosin heavy chain IIx fibre complement. The concentration of the pro-inflammatory cytokine interleukin-1β was reduced and the concentration of the anti-inflammatory cytokine interleukin-10 was increased in mdx diaphragm following drug co-treatment. Our novel findings may have implications for the development of pharmacotherapies for the dystrophinopathies with relevance for respiratory muscle performance and breathing. ABSTRACT The mdx mouse model of Duchenne muscular dystrophy shows evidence of hypoventilation and pronounced diaphragm dysfunction. Six-week-old male mdx (n = 32) and wild-type (WT; n = 32) mice received either saline (0.9% w/v) or a co-administration of neutralizing interleukin-6 receptor antibodies (xIL-6R; 0.2 mg kg-1 ) and corticotrophin-releasing factor receptor 2 agonist (urocortin-2; 30 μg kg-1 ) subcutaneously over 2 weeks. Breathing and diaphragm muscle contractile function (ex vivo) were examined. Diaphragm structure was assessed using histology and immunofluorescence. Muscle cytokine concentration was determined using a multiplex assay. Minute ventilation and diaphragm muscle peak force at 100 Hz were significantly depressed in mdx compared with WT. Drug treatment completely restored ventilation in mdx mice during normoxia and significantly increased mdx diaphragm force- and power-generating capacity. The number of centrally nucleated muscle fibres and the areal density of infiltrates and collagen content were significantly increased in mdx diaphragm; all indices were unaffected by drug co-treatment. The abundance of myosin heavy chain (MyHC) type IIx fibres was significantly decreased in mdx diaphragm; drug co-treatment preserved MyHC type IIx complement in mdx muscle. Drug co-treatment increased the cross-sectional area of MyHC type I and IIx fibres in mdx diaphragm. The cytokines IL-1β, IL-6, KC/GRO and TNF-α were significantly increased in mdx diaphragm compared with WT. Drug co-treatment significantly decreased IL-1β and increased IL-10 in mdx diaphragm. Drug co-treatment had no significant effect on WT diaphragm muscle structure, cytokine concentrations or function. Recovery of breathing and diaphragm force in mdx mice was impressive in our studies, with implication for human dystrophinopathies.
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Affiliation(s)
- David P. Burns
- Department of PhysiologySchool of MedicineCollege of Medicine and HealthUniversity College CorkCorkIreland
| | - Leonie Canavan
- Department of PhysiologySchool of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of DublinDublinIreland
| | - Jane Rowland
- Department of PhysiologySchool of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of DublinDublinIreland
| | - Robin O'Flaherty
- Department of PhysiologySchool of MedicineCollege of Medicine and HealthUniversity College CorkCorkIreland
| | - Molly Brannock
- Department of PhysiologySchool of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of DublinDublinIreland
| | - Sarah E. Drummond
- Department of PhysiologySchool of MedicineCollege of Medicine and HealthUniversity College CorkCorkIreland
| | - Dervla O'Malley
- Department of PhysiologySchool of MedicineCollege of Medicine and HealthUniversity College CorkCorkIreland
| | - Deirdre Edge
- Department of PhysiologySchool of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, the University of DublinDublinIreland
| | - Ken D. O'Halloran
- Department of PhysiologySchool of MedicineCollege of Medicine and HealthUniversity College CorkCorkIreland
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TAVARES-SILVA M, FERREIRA D, CARDOSO S, RAIMUNDO AR, BARBOSA-BREDA J, LEITE-MOREIRA A, ROCHA-SOUSA A. Modulation of Iris Sphincter and Ciliary Muscles by Urocortin 2. Physiol Res 2018. [DOI: 10.33549/physiolres.933646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Urocortin 2 (UCN2) is a peptide related to corticotropin-releasing factor, capable of activating CRF-R2. Among its multisystemic effects, it has actions in all 3 muscle subtypes. This study’s aim was to determine its potential role in two of the intrinsic eye muscle kinetics. Strips of iris sphincter (rabbit) and ciliary (bovine) muscles were dissected and mounted in isometric force-transducer systems filled with aerated-solutions. Contraction was elicited using carbachol (10-6 M for iris sphincter, 10-5 M for ciliary muscle), prior adding to all testing substances. UCN2 induced relaxation in iris sphincter muscle, being the effect maximal at 10-7 M concentrations (-12.2 % variation vs. control). This effect was abolished with incubation of indomethacin, antisauvagine-30, chelerytrine and SQ22536, but preserved with L-nitro-L-arginine. In carbachol pre-stimulated ciliary muscle, UCN2 (10-5 M) enhanced contraction (maximal effect of 18.2 % increase vs. control). UCN2 is a new modulator of iris sphincter relaxation, dependent of CRF-R2 activation, synthesis of prostaglandins (COX pathway) and both adenylate cyclase and PKC signaling pathways, but independent of nitric oxide production. Regarding ciliary muscle, UCN2 enhances carbachol-induced contraction, in higher doses.
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Affiliation(s)
| | | | | | | | | | | | - A. ROCHA-SOUSA
- Department of Surgery and Physiology, Faculty of Medicine, University of Porto, Portugal
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7
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Burns DP, Rowland J, Canavan L, Murphy KH, Brannock M, O'Malley D, O'Halloran KD, Edge D. Restoration of pharyngeal dilator muscle force in dystrophin-deficient (mdx) mice following co-treatment with neutralizing interleukin-6 receptor antibodies and urocortin 2. Exp Physiol 2017; 102:1177-1193. [PMID: 28665499 DOI: 10.1113/ep086232] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 06/19/2017] [Indexed: 12/26/2022]
Abstract
NEW FINDINGS What is the central question of this study? We previously reported impaired upper airway dilator muscle function in the mdx mouse model of Duchenne muscular dystrophy (DMD). Our aim was to assess the effect of blocking interleukin-6 receptor signalling and stimulating corticotrophin-releasing factor receptor 2 signalling on mdx sternohyoid muscle structure and function. What is the main finding and its importance? The interventional treatment had a positive inotropic effect on sternohyoid muscle force, restoring mechanical work and power to wild-type values, reduced myofibre central nucleation and preserved the myosin heavy chain type IIb fibre complement of mdx sternohyoid muscle. These data might have implications for development of pharmacotherapies for DMD with relevance to respiratory muscle performance. The mdx mouse model of Duchenne muscular dystrophy shows evidence of impaired pharyngeal dilator muscle function. We hypothesized that inflammatory and stress-related factors are implicated in airway dilator muscle dysfunction. Six-week-old mdx (n = 26) and wild-type (WT; n = 26) mice received either saline (0.9% w/v) or a co-administration of neutralizing interleukin-6 receptor antibodies (0.2 mg kg-1 ) and corticotrophin-releasing factor receptor 2 agonist (urocortin 2; 30 μg kg-1 ) over 2 weeks. Sternohyoid muscle isometric and isotonic contractile function was examined ex vivo. Muscle fibre centronucleation and muscle cellular infiltration, collagen content, fibre-type distribution and fibre cross-sectional area were determined by histology and immunofluorescence. Muscle chemokine content was examined by use of a multiplex assay. Sternohyoid peak specific force at 100 Hz was significantly reduced in mdx compared with WT. Drug treatment completely restored force in mdx sternohyoid to WT levels. The percentage of centrally nucleated muscle fibres was significantly increased in mdx, and this was partly ameliorated after drug treatment. The areal density of infiltrates and collagen content were significantly increased in mdx sternohyoid; both indices were unaffected by drug treatment. The abundance of myosin heavy chain type IIb fibres was significantly decreased in mdx sternohyoid; drug treatment preserved myosin heavy chain type IIb complement in mdx muscle. The chemokines macrophage inflammatory protein 2, interferon-γ-induced protein 10 and macrophage inflammatory protein 3α were significantly increased in mdx sternohyoid compared with WT. Drug treatment significantly increased chemokine expression in mdx but not WT sternohyoid. Recovery of contractile function was impressive in our study, with implications for Duchenne muscular dystrophy. The precise molecular mechanisms by which the drug treatment exerts an inotropic effect on mdx sternohyoid muscle remain to be elucidated.
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Affiliation(s)
- David P Burns
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Jane Rowland
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Leonie Canavan
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Kevin H Murphy
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Molly Brannock
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Dervla O'Malley
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, University College Cork, Cork, Ireland
| | - Deirdre Edge
- Department of Physiology, Trinity Biomedical Sciences Institute, Trinity College Dublin, The University of Dublin, Dublin, Ireland
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8
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Manning J, Buckley MM, O'Halloran KD, O'Malley D. Combined XIL-6R and urocortin-2 treatment restores MDX diaphragm muscle force. Muscle Nerve 2017; 56:E134-E140. [PMID: 28294390 DOI: 10.1002/mus.25644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/23/2017] [Accepted: 03/07/2017] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Duchenne muscular dystrophy (DMD) is characterized by progressive muscle degeneration leading to immobility, respiratory failure, and premature death. As chronic inflammation and stress are implicated in DMD pathology, the efficacy of an anti-inflammatory and anti-stress intervention strategy in ameliorating diaphragm dysfunction was investigated. METHODS Diaphragm muscle contractile function was compared in wild-type and dystrophin-deficient mdx mice treated with saline, anti-interleukin-6 receptor antibodies (xIL-6R), the corticotrophin-releasing factor receptor 2 (CRFR2) agonist, urocortin 2, or both xIL-6R and urocortin 2. RESULTS Combined treatment with xIL-6R and urocortin 2 rescued impaired force in mdx diaphragms. Mechanical work production and muscle shortening was also improved by combined drug treatment. DISCUSSION Treatment which neutralizes peripheral IL-6 signaling and stimulates CRFR2 recovers force-generating capacity and the ability to perform mechanical work in mdx diaphragm muscle. These findings may be important in the search for therapeutic targets in DMD. Muscle Nerve 56: E134-E140, 2017.
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Affiliation(s)
- Jennifer Manning
- Department of Physiology, Western Gateway Building, University College Cork, Cork, Ireland
| | - Maria M Buckley
- Department of Physiology, Western Gateway Building, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, Western Gateway Building, University College Cork, Cork, Ireland
| | - Dervla O'Malley
- Department of Physiology, Western Gateway Building, University College Cork, Cork, Ireland
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Joshi R, Kadeer N, Sheriff S, Friend LA, James JH, Balasubramaniam A. Phosphodiesterase (PDE) inhibitor torbafylline (HWA 448) attenuates burn-induced rat skeletal muscle proteolysis through the PDE4/cAMP/EPAC/PI3K/Akt pathway. Mol Cell Endocrinol 2014; 393:152-63. [PMID: 24973766 DOI: 10.1016/j.mce.2014.06.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 06/02/2014] [Accepted: 06/16/2014] [Indexed: 10/25/2022]
Abstract
Treatment of rats after burn-injury with the cyclic AMP phosphodiesterase (PDE) inhibitor, torbafylline (also known as HWA 448) significantly reversed changes in rat skeletal muscle proteolysis, PDE4 activity, cAMP concentrations and mRNA expression of TNFα, IL-6, ubiquitin and E3 ligases. Torbafylline also attenuated muscle proteolysis during in vitro incubation, and this effect was blocked by the inhibitor Rp-cAMPS. Moreover, torbafylline significantly increased phospho-Akt levels, and normalized downregulated phospho-FOXO1 and phospho-4E-BP1 in muscle of burn rats. Similarly, torbafylline also normalized phosphorylation levels of Akt and its downstream elements in TNFα+IFNγ treated C2C12 myotubes. Torbafylline enhanced protein levels of exchange protein directly activated by cAMP (Epac) both in skeletal muscle of burn rats and in TNFα+IFNγ treated C2C12 myotubes. Pretreatment with a specific antagonist of PI3K or Epac significantly reversed the inhibitory effects of torbafylline on TNFα+IFNγ-induced MAFbx mRNA expression and protein breakdown in C2C12 myotubes. Torbafylline inhibits burn-induced muscle proteolysis by activating multiple pathways through PDE4/cAMP/Epac/PI3K/Akt.
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Affiliation(s)
- Rashika Joshi
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Nijiati Kadeer
- Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Sulaiman Sheriff
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA
| | - Lou Ann Friend
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - J Howard James
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA
| | - Ambikaipakan Balasubramaniam
- Department of Surgery, University of Cincinnati College of Medicine, 231 Albert Sabin Way, Cincinnati, OH 45267, USA; Shriners Hospital for Children, 3229 Burnet Avenue, Cincinnati, OH 45229, USA; Cincinnati Veterans Affairs Medical Center, 3200 Vine Street, Cincinnati, OH 45220, USA.
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Thalacker-Mercer A, Stec M, Cui X, Cross J, Windham S, Bamman M. Cluster analysis reveals differential transcript profiles associated with resistance training-induced human skeletal muscle hypertrophy. Physiol Genomics 2013; 45:499-507. [PMID: 23632419 DOI: 10.1152/physiolgenomics.00167.2012] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Using genomic microarray analysis, we sought to identify and annotate differences in the pretraining skeletal muscle transcriptomes among human subjects clustered as nonresponders (Non), modest responders (Mod), and extreme responders (Xtr) based on differential magnitudes of myofiber hypertrophy in response to progressive resistance training (RT) (Non-6 μm², Mod 1,111 μm², or Xtr 2,475 μm²). In prior work, we noted differences among clusters in the prevalence of myogenic stem cells prior to and during RT (35), and in the translational signaling responses to the first bout of resistance exercise (30). Here we identified remarkable differences in the pretraining transcript profiles among clusters (8,026 gene transcripts differentially expressed between Xtr and Non, 2,463 between Xtr and Mod, and 1,294 between Mod and Non). Annotated functions and networks of differentially expressed genes suggest Xtr were "primed" to respond to RT through transcriptional regulation, along with a uniquely expressed network of genes involved in skeletal muscle development, while the failed response in Non may have been driven by excessive proinflammatory signaling. Protein follow-up analysis revealed higher basal levels of acetylated histone H3 (K36) in the two responder clusters (Mod, Xtr) compared with Non, and only the responders experienced alterations in the muscle content of select proteins (e.g., α-tubulin, p27(kip)) in response to the first resistance exercise stimulus. Overall, the widely disparate transcriptomes identified prior to RT among the three clusters support the notion that at least some of the interindividual heterogeneity in propensity for RT-induced myofiber hypertrophy is likely predetermined.
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Affiliation(s)
- Anna Thalacker-Mercer
- UAB Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
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Berdeaux R, Stewart R. cAMP signaling in skeletal muscle adaptation: hypertrophy, metabolism, and regeneration. Am J Physiol Endocrinol Metab 2012; 303:E1-17. [PMID: 22354781 PMCID: PMC3404564 DOI: 10.1152/ajpendo.00555.2011] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 02/09/2012] [Indexed: 12/11/2022]
Abstract
Among organ systems, skeletal muscle is perhaps the most structurally specialized. The remarkable subcellular architecture of this tissue allows it to empower movement with instructions from motor neurons. Despite this high degree of specialization, skeletal muscle also has intrinsic signaling mechanisms that allow adaptation to long-term changes in demand and regeneration after acute damage. The second messenger adenosine 3',5'-monophosphate (cAMP) not only elicits acute changes within myofibers during exercise but also contributes to myofiber size and metabolic phenotype in the long term. Strikingly, sustained activation of cAMP signaling leads to pronounced hypertrophic responses in skeletal myofibers through largely elusive molecular mechanisms. These pathways can promote hypertrophy and combat atrophy in animal models of disorders including muscular dystrophy, age-related atrophy, denervation injury, disuse atrophy, cancer cachexia, and sepsis. cAMP also participates in muscle development and regeneration mediated by muscle precursor cells; thus, downstream signaling pathways may potentially be harnessed to promote muscle regeneration in patients with acute damage or muscular dystrophy. In this review, we summarize studies implicating cAMP signaling in skeletal muscle adaptation. We also highlight ligands that induce cAMP signaling and downstream effectors that are promising pharmacological targets.
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Affiliation(s)
- Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, USA.
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Reutenauer-Patte J, Boittin FX, Patthey-Vuadens O, Ruegg UT, Dorchies OM. Urocortins improve dystrophic skeletal muscle structure and function through both PKA- and Epac-dependent pathways. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 180:749-62. [PMID: 22192627 DOI: 10.1016/j.ajpath.2011.10.038] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 10/14/2011] [Accepted: 10/23/2011] [Indexed: 02/03/2023]
Abstract
In Duchenne muscular dystrophy, the absence of dystrophin causes progressive muscle wasting and premature death. Excessive calcium influx is thought to initiate the pathogenic cascade, resulting in muscle cell death. Urocortins (Ucns) have protected muscle in several experimental paradigms. Herein, we demonstrate that daily s.c. injections of either Ucn 1 or Ucn 2 to 3-week-old dystrophic mdx(5Cv) mice for 2 weeks increased skeletal muscle mass and normalized plasma creatine kinase activity. Histological examination showed that Ucns remarkably reduced necrosis in the diaphragm and slow- and fast-twitch muscles. Ucns improved muscle resistance to mechanical stress provoked by repetitive tetanizations. Ucn 2 treatment resulted in faster kinetics of contraction and relaxation and a rightward shift of the force-frequency curve, suggesting improved calcium homeostasis. Ucn 2 decreased calcium influx into freshly isolated dystrophic muscles. Pharmacological manipulation demonstrated that the mechanism involved the corticotropin-releasing factor type 2 receptor, cAMP elevation, and activation of both protein kinase A and the cAMP-binding protein Epac. Moreover, both STIM1, the calcium sensor that initiates the assembly of store-operated channels, and the calcium-independent phospholipase A(2) that activates these channels were reduced in dystrophic muscle by Ucn 2. Altogether, our results demonstrate the high potency of Ucns for improving dystrophic muscle structure and function, suggesting that these peptides may be considered for treatment of Duchenne muscular dystrophy.
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Affiliation(s)
- Julie Reutenauer-Patte
- Laboratory of Pharmacology, Geneva-Lausanne School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, Geneva, Switzerland
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13
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Jamieson PM, Cleasby ME, Kuperman Y, Morton NM, Kelly PAT, Brownstein DG, Mustard KJ, Vaughan JM, Carter RN, Hahn CN, Hardie DG, Seckl JR, Chen A, Vale WW. Urocortin 3 transgenic mice exhibit a metabolically favourable phenotype resisting obesity and hyperglycaemia on a high-fat diet. Diabetologia 2011; 54:2392-403. [PMID: 21667214 PMCID: PMC3149678 DOI: 10.1007/s00125-011-2205-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 04/26/2011] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS Urocortins are the endogenous ligands for the corticotropin-releasing factor receptor type 2 (CRFR2), which is implicated in regulating energy balance and/or glucose metabolism. We determined the effects of chronic CRFR2 activation on metabolism in vivo, by generating and phenotyping transgenic mice overproducing the specific CRFR2 ligand urocortin 3. METHODS Body composition, glucose metabolism, insulin sensitivity, energy efficiency and expression of key metabolic genes were assessed in adult male urocortin 3 transgenic mice (Ucn3(+)) under control conditions and following an obesogenic high-fat diet (HFD) challenge. RESULTS Ucn3(+) mice had increased skeletal muscle mass with myocyte hypertrophy. Accelerated peripheral glucose disposal, increased respiratory exchange ratio and hypoglycaemia on fasting demonstrated increased carbohydrate metabolism. Insulin tolerance and indices of insulin-stimulated signalling were unchanged, indicating these effects were not mediated by increased insulin sensitivity. Expression of the transgene in Crfr2 (also known as Crhr2)-null mice negated key aspects of the Ucn3(+) phenotype. Ucn3(+) mice were protected from the HFD-induced hyperglycaemia and increased adiposity seen in control mice despite consuming more energy. Expression of uncoupling proteins 2 and 3 was higher in Ucn3(+) muscle, suggesting increased catabolic processes. IGF-1 abundance was upregulated in Ucn3(+) muscle, providing a potential paracrine mechanism in which urocortin 3 acts upon CRFR2 to link the altered metabolism and muscular hypertrophy observed. CONCLUSIONS/INTERPRETATION Urocortin 3 acting on CRFR2 in skeletal muscle of Ucn3(+) mice results in a novel metabolically favourable phenotype, with lean body composition and protection against diet-induced obesity and hyperglycaemia. Urocortins and CRFR2 may be of interest as potential therapeutic targets for obesity.
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MESH Headings
- Animals
- Body Composition/drug effects
- Body Composition/physiology
- Dietary Fats/adverse effects
- Dietary Fats/pharmacology
- Disease Models, Animal
- Energy Metabolism/drug effects
- Energy Metabolism/physiology
- Glucose/metabolism
- Hyperglycemia/metabolism
- Hyperglycemia/prevention & control
- Insulin/blood
- Insulin-Like Growth Factor I/metabolism
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Obesity/metabolism
- Obesity/prevention & control
- Phenotype
- Receptors, Corticotropin-Releasing Hormone/deficiency
- Receptors, Corticotropin-Releasing Hormone/genetics
- Receptors, Corticotropin-Releasing Hormone/metabolism
- Urocortins/genetics
- Urocortins/metabolism
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Affiliation(s)
- P M Jamieson
- Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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14
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Hinkle RT, Lefever FR, Dolan ET, Reichart DL, Zwolshen JM, Oneill TP, Maloney KG, Mattson JP, Ferreira LF, Musch TI, Poole DC, Isfort RJ. Treatment with a corticotrophin releasing factor 2 receptor agonist modulates skeletal muscle mass and force production in aged and chronically ill animals. BMC Musculoskelet Disord 2011; 12:15. [PMID: 21235761 PMCID: PMC3025927 DOI: 10.1186/1471-2474-12-15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 01/14/2011] [Indexed: 11/17/2022] Open
Abstract
Background Muscle weakness is associated with a variety of chronic disorders such as emphysema (EMP) and congestive heart failure (CHF) as well as aging. Therapies to treat muscle weakness associated with chronic disease or aging are lacking. Corticotrophin releasing factor 2 receptor (CRF2R) agonists have been shown to maintain skeletal muscle mass and force production in a variety of acute conditions that lead to skeletal muscle wasting. Hypothesis We hypothesize that treating animals with a CRF2R agonist will maintain skeletal muscle mass and force production in animals with chronic disease and in aged animals. Methods We utilized animal models of aging, CHF and EMP to evaluate the potential of CRF2R agonist treatment to maintain skeletal muscle mass and force production in aged animals and animals with CHF and EMP. Results In aged rats, we demonstrate that treatment with a CRF2R agonist for up to 3 months results in greater extensor digitorum longus (EDL) force production, EDL mass, soleus mass and soleus force production compared to age matched untreated animals. In the hamster EMP model, we demonstrate that treatment with a CRF2R agonist for up to 5 months results in greater EDL force production in EMP hamsters when compared to vehicle treated EMP hamsters and greater EDL mass and force in normal hamsters when compared to vehicle treated normal hamsters. In the rat CHF model, we demonstrate that treatment with a CRF2R agonist for up to 3 months results in greater EDL and soleus muscle mass and force production in CHF rats and normal rats when compared to the corresponding vehicle treated animals. Conclusions These data demonstrate that the underlying physiological conditions associated with chronic diseases such as CHF and emphysema in addition to aging do not reduce the potential of CRF2R agonists to maintain skeletal muscle mass and force production.
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15
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Tezval M, Tezval H, Dresing K, Stuermer EK, Blaschke M, Stuermer KM, Siggelkow H. Differentiation dependent expression of urocortin's mRNA and peptide in human osteoprogenitor cells: influence of BMP-2, TGF-beta-1 and dexamethasone. J Mol Histol 2009; 40:331-41. [PMID: 19949969 PMCID: PMC2834774 DOI: 10.1007/s10735-009-9244-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 11/19/2009] [Indexed: 11/30/2022]
Abstract
Urocortin-1 (UCN) a corticotropin releasing-factor (CRF) related peptide, has been found to be expressed in many different tissues like the central nervous system, the cardiovascular system, adipose tissue, and skeletal muscle. The effects of UCN are mediated via stimulation of CRF-receptors 1 and 2 (CRFR1 and 2, CRFR’s) with a high affinity for CRFR2. It has been shown that the CRF-related peptides and CRFR’s are involved in the regulation of stress-related endocrine, autonomic and behavioural responses. Using immunocytochemistry, immunohistochemistry and RT–PCR, we now can show the differentiation dependent expression of UCN mRNA and peptide in human mesenchymal progenitor cells (MSCs) directed to the osteoblastic phenotype for the first time. UCN expression was down regulated by TGF-beta and BMP-2 in the early proliferation phase of osteoblast development, whereas dexamethasone (dex) minimally induced UCN gene expression during matrix maturation after 24 h stimulation. Stimulation of MSCs for 28 days with ascorbate/beta-glycerophosphate (asc/bGp) induced UCN gene expression at day 14. This effect was prevented when using 1,25-vitamin D3 or dex in addition. There was no obvious correlation to osteocalcin (OCN) gene expression in these experiments. In MSCs from patients with metabolic bone disease (n = 9) UCN gene expression was significantly higher compared to MSCs from normal controls (n = 6). Human MSCs did not express any of the CRFR’s during differentiation to osteoblasts. Our results indicate that UCN is produced during the development of MSCs to osteoblasts and differentially regulated during culture as well as by differentiation factors. The expression is maximal between proliferation and matrix maturation phase. However, UCN does not seem to act on the osteoblast itself as shown by the missing CRFR’s. Our results suggest new perspectives on the role of urocortin in human skeletal tissue in health and disease.
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Affiliation(s)
- Mohammad Tezval
- Department of Trauma, Plastic and Reconstructive Surgery, Goettingen University Hospital, University Medicine Goetingen, Robert Koch Str. 40, 37075 Goettingen, Germany.
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16
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Hall JE, Kaczor JJ, Hettinga BP, Isfort RJ, Tarnopolsky MA. Effects of a CRF2R agonist and exercise on mdx and wildtype skeletal muscle. Muscle Nerve 2007; 36:336-41. [PMID: 17503504 DOI: 10.1002/mus.20820] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Corticotrophin-releasing factor 2 receptor (CRF2R) agonists prevent muscle atrophy due to immobilization, denervation, and corticosteroid-induced muscle atrophy in wildtype mice. We hypothesized that a CRF2R agonist will increase skeletal muscle mass in mdx mice. Mdx (C57BL/10ScSn-Dmd(mdx)) and wildtype (C57BL/6) mice were divided into four groups: sedentary placebo, sedentary CRF2R agonist, exercised placebo, and exercised CRF2R agonist. Mice exercised on a treadmill twice weekly for 30 min (8-12 m/min, 8 weeks). Muscle and heart weights, serum creatine kinase, and gamma-glutamyltransferase activities were measured. The CRF2R agonist increased extensor digitorum longus and soleus muscle weights (P < 0.05) in wildtype and mdx mice. Sedentary mdx CRF2R and exercised mdx placebo mice had lower serum creatine kinase activity than sedentary mdx placebo mice. CRF2R-treated mice had decreased heart weights compared to placebo-treated mice. We conclude that CRF2R agonists should be further evaluated as a potential therapy for dystrophinopathies.
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Affiliation(s)
- Julie E Hall
- Department of Pediatrics, Rm. 2H18, McMaster University Medical Center, 1200 Main Street W., Hamilton, Ontario L8N 3Z5, Canada
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17
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Hinkle RT, Lefever FR, Dolan ET, Reichart DL, Dietrich JA, Gropp KE, Thacker RI, Demuth JP, Stevens PJ, Qu XA, Varbanov AR, Wang F, Isfort RJ. Corticortophin releasing factor 2 receptor agonist treatment significantly slows disease progression in mdx mice. BMC Med 2007; 5:18. [PMID: 17626629 PMCID: PMC1936998 DOI: 10.1186/1741-7015-5-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 07/12/2007] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy results from mutation of the dystrophin gene, causing skeletal and cardiac muscle loss of function. The mdx mouse model of Duchenne muscular dystrophy is widely utilized to evaluate the potential of therapeutic regimens to modulate the loss of skeletal muscle function associated with dystrophin mutation. Importantly, progressive loss of diaphragm function is the most consistent striated muscle effect observed in the mdx mouse model, which is the same as in patients suffering from Duchenne muscular dystrophy. METHODS Using the mdx mouse model, we have evaluated the effect that corticotrophin releasing factor 2 receptor (CRF2R) agonist treatment has on diaphragm function, morphology and gene expression. RESULTS We have observed that treatment with the potent CRF2R-selective agonist PG-873637 prevents the progressive loss of diaphragm specific force observed during aging of mdx mice. In addition, the combination of PG-873637 with glucocorticoids not only prevents the loss of diaphragm specific force over time, but also results in recovery of specific force. Pathological analysis of CRF2R agonist-treated diaphragm muscle demonstrates that treatment reduces fibrosis, immune cell infiltration, and muscle architectural disruption. Gene expression analysis of CRF2R-treated diaphragm muscle showed multiple gene expression changes including globally decreased immune cell-related gene expression, decreased extracellular matrix gene expression, increased metabolism-related gene expression, and, surprisingly, modulation of circadian rhythm gene expression. CONCLUSION Together, these data demonstrate that CRF2R activation can prevent the progressive degeneration of diaphragm muscle associated with dystrophin gene mutation.
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Affiliation(s)
- Richard T Hinkle
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Frank R Lefever
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | | | | | | | - Kathryn E Gropp
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Robert I Thacker
- Department of Pathobiology and Molecular Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Jeffrey P Demuth
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Paula J Stevens
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Xiaoyan A Qu
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Alex R Varbanov
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Feng Wang
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
| | - Robert J Isfort
- Research Division, Procter & Gamble Pharmaceuticals, Mason, OH, USA
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18
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Arai C, Ohnuki Y, Umeki D, Hirashita A, Saeki Y. Effects of Clenbuterol and Cyclosporin A on the Myosin Heavy Chain mRNA Level and the Muscle Mass in Rat Masseter. J Physiol Sci 2006; 56:205-9. [PMID: 16839454 DOI: 10.2170/physiolsci.rp002206] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 05/22/2006] [Indexed: 11/05/2022]
Abstract
To gain more insight into the molecular mechanism of muscle growth and fiber-type transformations, we analyzed the effects of beta(2)-adrenergic agonist clenbuterol (CB) and/or cyclosporin A (CsA), a potent inhibitor of calcineurin (CaN), on the muscle mass as well as on the mRNA levels of myosin heavy chains (MHC I, IIa, IId/x, IIb), using a real-time RT-PCR with specific primers in rat masseter. In comparison with control, the CB treatment significantly decreased the MHC I mRNA level (p < 0.01), but increased the MHC IId/x mRNA level (p < 0.01), and the CsA treatment significantly decreased the MHC I mRNA level (p < 0.05) in association with the significant decrease in MHC IIb mRNA level (p < 0.05). The CB+CsA treatment significantly decreased the levels of MHC I (p < 0.01) and IIa mRNAs (p < 0.05), but increased the MHC IId/x mRNA level (p < 0.001) in association with a significant decrease in MHC IIb mRNA level (p < 0.01), in comparison with control. The masseter muscle mass was significantly (p < 0.001) increased by either the CB or the CB + CsA treatment, but decreased with the CsA treatment (p < 0.01). These results suggest that in rat masseter muscle, CB has an anabolic action accompanying MHC mRNA I IIa IId/x sequence transition independently of CaN-signaling pathways, and CaN is involved in the type I fiber gene expression and the muscle mass maintenance of type IIb fiber.
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Affiliation(s)
- Chihiro Arai
- Department of Orthodontics, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan
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Arai C, Ohnuki Y, Umeki D, Saeki Y. Effects of Bite-Opening and Cyclosporin A on the mRNA Levels of Myosin Heavy Chain and the Muscle Mass in Rat Masseter. ACTA ACUST UNITED AC 2005; 55:173-9. [PMID: 16080800 DOI: 10.2170/jjphysiol.r2123] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Accepted: 08/04/2005] [Indexed: 11/05/2022]
Abstract
To gain more insight into the mechanism of muscle plasticity in response to mechanical overload, we analyzed the effects of bite -opening (BO, 3 mm increase in the vertical dimension for 2 weeks) and/or a calcineurin (CaN) inhibitor, cyclosporin A (CsA, 10 mg/kg body weight, once daily for 2 weeks, ip) treatment on the myosin heavy chain (MHC I, IIa, IId/x, IIb) mRNA levels, using real-time RT-PCR with specific primers and on the muscle mass in rat masseter. As compared with normal control (n = 6), the BO treatment (n = 6) significantly increased the MHC I (p < 0.05) and the IIa mRNA levels (p < 0.01), and the CsA treatment (n = 6) significantly decreased the MHC I mRNA level (p < 0.01) in association with the significant decrease in the MHC IIb mRNA level (p < 0.05). The BO + CsA treatment (n = 6) significantly increased the MHC IIa mRNA level (p < 0.01) in association with the significant decrease in the MHC IIb mRNA level (p < 0.01), as compared with control. The masseter muscle mass was significantly decreased by either the CsA (p < 0.05) or the BO + CsA treatment (p < 0.001), but slightly increased by the BO treatment. These results suggest that in rat masseter the BO treatment produces not only the up-regulation of MHC IIa mRNA independently of CaN-signaling pathways, but also the MHC mRNA transition from IIa to I and the muscle mass maintenance mainly of type IIb fiber through the CaN-signaling pathways.
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Affiliation(s)
- Chihiro Arai
- Department of Orthodontics, Tsurumi University School of Dental Medicine, Tsurumi-ku, Yokohama 230-8501, Japan
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