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Wong KS, Cheung HW, Choi YC, To NS, Wan TSM, Ho ENM. Screening and confirmation of recombinant human follistatin in equine plasma for doping control purposes. Drug Test Anal 2024; 16:259-267. [PMID: 37401514 DOI: 10.1002/dta.3540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 04/19/2023] [Accepted: 06/15/2023] [Indexed: 07/05/2023]
Abstract
Recombinant human follistatin (rhFST) is a potential performance-enhancing agent owing to its stimulating effect on muscle growth. Administration of rhFST to athletes is prohibited in human sports by the World Anti-Doping Agency (WADA) and in horseracing according to Article 6 of the International Agreement on Breeding, Racing and Wagering published by the International Federation of Horseracing Authorities (IFHA). For effective control of the potential misuse of rhFST in flat racing, methods for screening and confirmatory analysis are required. This paper describes the development and validation of a complete solution for detecting rhFST and confirming its presence in plasma samples collected from racehorses. A high-throughput analysis of rhFST with a commercially available enzyme-linked immunosorbent assay (ELISA) was evaluated for the screening of equine plasma samples. Any suspicious finding would then be subjected to a confirmatory analysis using immunocapture, followed by nano-liquid chromatography/high-resolution tandem mass spectrometry (nanoLC-MS/HRMS). The confirmation of rhFST by nanoLC-MS/HRMS was achieved by comparing the retention times and relative abundances of three characteristic product-ions with those from the reference standard in accordance with the industry criteria published by the Association of Official Racing Chemists. The two methods achieved comparable limit of detection (~2.5-5 ng/mL) and limit of confirmation (2.5 ng/mL or below), as well as adequate specificity, precision and reproducibility. To our knowledge, this is the first report of the screening and confirmation methods for rhFST in equine samples.
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Affiliation(s)
- Kin-Sing Wong
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Hiu Wing Cheung
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Yung-Ching Choi
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Ning-Sum To
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Terence S M Wan
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
| | - Emmie N M Ho
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N. T., Hong Kong, China
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2
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Sosa J, Oyelakin A, Sinha S. The Reign of Follistatin in Tumors and Their Microenvironment: Implications for Drug Resistance. BIOLOGY 2024; 13:130. [PMID: 38392348 PMCID: PMC10887188 DOI: 10.3390/biology13020130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 02/10/2024] [Accepted: 02/16/2024] [Indexed: 02/24/2024]
Abstract
Follistatin (FST) is a potent neutralizer of the transforming growth factor-β superfamily and is associated with normal cellular programs and various hallmarks of cancer, such as proliferation, migration, angiogenesis, and immune evasion. The aberrant expression of FST by solid tumors is a well-documented observation, yet how FST influences tumor progression and therapy response remains unclear. The recent surge in omics data has revealed new insights into the molecular foundation underpinning tumor heterogeneity and its microenvironment, offering novel precision medicine-based opportunities to combat cancer. In this review, we discuss these recent FST-centric studies, thereby offering an updated perspective on the protean role of FST isoforms in shaping the complex cellular ecosystem of tumors and in mediating drug resistance.
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Affiliation(s)
- Jennifer Sosa
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Akinsola Oyelakin
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle Children's Hospital, Seattle, WA 98101, USA
- Ben Towne Center for Childhood Cancer Research, Seattle Children's Research Institute, Seattle Children's Hospital, Seattle, WA 98101, USA
| | - Satrajit Sinha
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
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3
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Bielka W, Przezak A, Pawlik A. Follistatin and follistatin-like 3 in metabolic disorders. Prostaglandins Other Lipid Mediat 2023; 169:106785. [PMID: 37739334 DOI: 10.1016/j.prostaglandins.2023.106785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 09/02/2023] [Accepted: 09/16/2023] [Indexed: 09/24/2023]
Abstract
Follistatin (FST) is a glycoprotein which main role is antagonizing activity of transforming growth factor β superfamily members. Folistatin-related proteins such as follistatin-like 3 (FSTL3) also reveal these properties. The exact function of them has still not been established, but it can be bound to the pathogenesis of metabolic disorders. So far, there were performed a few studies about their role in type 2 diabetes, obesity or gestational diabetes and even less in type 1 diabetes. The outcomes are contradictory and do not allow to draw exact conclusions. In this article we summarize the available information about connections between follistatin, as well as follistatin-like 3, and metabolic disorders. We also emphasize the strong need of performing further research to explain their exact role, especially in the pathogenesis of diabetes and obesity.
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Affiliation(s)
- Weronika Bielka
- Department of Rheumatology and Internal Medicine, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Agnieszka Przezak
- Department of Rheumatology and Internal Medicine, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Andrzej Pawlik
- Department of Physiology, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland.
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4
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Hatamzade Esfahani N, Day AS. The Role of TGF-β, Activin and Follistatin in Inflammatory Bowel Disease. GASTROINTESTINAL DISORDERS 2023; 5:167-186. [DOI: 10.3390/gidisord5020015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/10/2023] Open
Abstract
Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition predominantly affecting the gastrointestinal (GI) tract. An increasing prevalence of IBD has been observed globally. The pathogenesis of IBD includes a complex interplay between the intestinal microbiome, diet, genetic factors and immune responses. The consequent imbalance of inflammatory mediators ultimately leads to intestinal mucosal damage and defective repair. Growth factors, given their specific roles in maintaining the homeostasis and integrity of the intestinal epithelium, are of particular interest in the setting of IBD. Furthermore, direct targeting of growth factor signalling pathways involved in the regeneration of the damaged epithelium and the regulation of inflammation could be considered as therapeutic options for individuals with IBD. Several members of the transforming growth factor (TGF)-β superfamily, particularly TGF-β, activin and follistatin, are key candidates as they exhibit various roles in inflammatory processes and contribute to maintenance and homeostasis in the GI tract. This article aimed firstly to review the events involved in the pathogenesis of IBD with particular emphasis on TGF-β, activin and follistatin and secondly to outline the potential role of therapeutic manipulation of these pathways.
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Affiliation(s)
| | - Andrew S. Day
- Paediatric Department, University of Otago Christchurch, Christchurch 8140, New Zealand
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Kappes EC, Kattamuri C, Czepnik M, Yarawsky AE, Brûlé E, Wang Y, Ongaro L, Herr AB, Walton KL, Bernard DJ, Thompson TB. Follistatin Forms a Stable Complex With Inhibin A That Does Not Interfere With Activin A Antagonism. Endocrinology 2023; 164:7010688. [PMID: 36718082 DOI: 10.1210/endocr/bqad017] [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: 11/04/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 02/01/2023]
Abstract
Inhibins are transforming growth factor-β family heterodimers that suppress follicle-stimulating hormone (FSH) secretion by antagonizing activin class ligands. Inhibins share a common β chain with activin ligands. Follistatin is another activin antagonist, known to bind the common β chain of both activins and inhibins. In this study, we characterized the antagonist-antagonist complex of inhibin A and follistatin to determine if their interaction impacted activin A antagonism. We isolated the inhibin A:follistatin 288 complex, showing that it forms in a 1:1 stoichiometric ratio, different from previously reported homodimeric ligand:follistatin complexes, which bind in a 1:2 ratio. Small angle X-ray scattering coupled with modeling provided a low-resolution structure of inhibin A in complex with follistatin 288. Inhibin binds follistatin via the shared activin β chain, leaving the α chain free and flexible. The inhibin A:follistatin 288 complex was also shown to bind heparin with lower affinity than follistatin 288 alone or in complex with activin A. Characterizing the inhibin A:follistatin 288 complex in an activin-responsive luciferase assay and by surface plasmon resonance indicated that the inhibitor complex readily dissociated upon binding type II receptor activin receptor type IIb, allowing both antagonists to inhibit activin signaling. Additionally, injection of the complex in ovariectomized female mice did not alter inhibin A suppression of FSH. Taken together, this study shows that while follistatin binds to inhibin A with a substochiometric ratio relative to the activin homodimer, the complex can dissociate readily, allowing both proteins to effectively antagonize activin signaling.
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Affiliation(s)
- Emily C Kappes
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, USA
| | - Chandramohan Kattamuri
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, USA
| | - Magdalena Czepnik
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, USA
| | | | - Emilie Brûlé
- Departments of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Ying Wang
- Departments of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Luisina Ongaro
- Departments of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Andrew B Herr
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kelly L Walton
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
- Department of Physiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Daniel J Bernard
- Departments of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Departments of Pharmacology and Therapeutics, McGill University, Montreal, QC, Canada
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, USA
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Lodberg A. Principles of the activin receptor signaling pathway and its inhibition. Cytokine Growth Factor Rev 2021; 60:1-17. [PMID: 33933900 DOI: 10.1016/j.cytogfr.2021.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 01/19/2023]
Abstract
This review captures the anabolic and stimulatory effects observed with inhibition of the transforming growth factor β superfamily in muscle, blood, and bone. New medicinal substances that rectify activin, myostatin, and growth differentiation factor 11 signaling give hope to the many whose lives are affected by deterioration of these tissues. The review first covers the origin, structure, and common pathway of activins, myostatin, and growth differentiation factor 11 along with the pharmacodynamics of the new class of molecules designed to oppose the activin receptor signaling pathway. Current terminology surrounding this new class of molecules is inconsistent and does not infer functionality. Adopting inhibitors of the activin receptor signaling pathway (IASPs) as a generic term is proposed because it encapsulates the molecular mechanisms along the pathway trajectory. To conclude, a pragmatic classification of IASPs is presented that integrates functionality and side effects based on the data available from animals and humans. This provides researchers and clinicians with a tool to tailor IASPs therapy according to the need of projects or patients and with respect to side effects.
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Affiliation(s)
- Andreas Lodberg
- Department of Biomedicine, Aarhus University, Department of Respiratory Diseases and Allergy, Aarhus University Hospital, Wilhelm Meyers Allé, DK-8000, Aarhus, Denmark.
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7
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Walker RG, Kattamuri C, Goebel EJ, Zhang F, Hammel M, Tainer JA, Linhardt RJ, Thompson TB. Heparin-mediated dimerization of follistatin. Exp Biol Med (Maywood) 2021; 246:467-482. [PMID: 33197333 PMCID: PMC7885052 DOI: 10.1177/1535370220966296] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 09/22/2020] [Indexed: 11/16/2022] Open
Abstract
Heparin and heparan sulfate (HS) are highly sulfated polysaccharides covalently bound to cell surface proteins, which directly interact with many extracellular proteins, including the transforming growth factor-β (TGFβ) family ligand antagonist, follistatin 288 (FS288). Follistatin neutralizes the TGFβ ligands, myostatin and activin A, by forming a nearly irreversible non-signaling complex by surrounding the ligand and preventing interaction with TGFβ receptors. The FS288-ligand complex has higher affinity than unbound FS288 for heparin/HS, which accelerates ligand internalization and lysosomal degradation; however, limited information is available for how FS288 interactions with heparin affect ligand binding. Using surface plasmon resonance (SPR) we show that preincubation of FS288 with heparin/HS significantly decreased the association kinetics for both myostatin and activin A with seemingly no effect on the dissociation rate. This observation is dependent on the heparin/HS chain length where small chain lengths less than degree of polymerization 10 (dp10) did not alter association rates but chain lengths >dp10 decreased association rates. In an attempt to understand the mechanism for this observation, we uncovered that heparin induced dimerization of follistatin. Consistent with our SPR results, we found that dimerization only occurs with heparin molecules >dp10. Small-angle X-ray scattering of the FS288 heparin complex supports that FS288 adopts a dimeric configuration that is similar to the FS288 dimer in the ligand-bound state. These results indicate that heparin mediates dimerization of FS288 in a chain-length-dependent manner that reduces the ligand association rate, but not the dissociation rate or antagonistic activity of FS288.
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Affiliation(s)
- Ryan G Walker
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
| | - Chandramohan Kattamuri
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
| | - Erich J Goebel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
| | - Fuming Zhang
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - Michal Hammel
- Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - John A Tainer
- Molecular and Cellular Oncology and Cancer Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
| | - Robert J Linhardt
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267, USA
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8
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Gipson GR, Goebel EJ, Hart KN, Kappes EC, Kattamuri C, McCoy JC, Thompson TB. Structural perspective of BMP ligands and signaling. Bone 2020; 140:115549. [PMID: 32730927 PMCID: PMC7502536 DOI: 10.1016/j.bone.2020.115549] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 06/30/2020] [Accepted: 07/03/2020] [Indexed: 12/13/2022]
Abstract
The Bone Morphogenetic Proteins (BMPs) are the largest class signaling molecules within the greater Transforming Growth Factor Beta (TGFβ) family, and are responsible for a wide array of biological functions, including dorsal-ventral patterning, skeletal development and maintenance, as well as cell homeostasis. As such, dysregulation of BMPs results in a number of diseases, including fibrodysplasia ossificans progressiva (FOP) and pulmonary arterial hypertension (PAH). Therefore, understanding BMP signaling and regulation at the molecular level is essential for targeted therapeutic intervention. This review discusses the recent advances in the structural and biochemical characterization of BMPs, from canonical ligand-receptor interactions to co-receptors and antagonists. This work aims to highlight how BMPs differ from other members of the TGFβ family, and how that information can be used to further advance the field. Lastly, this review discusses several gaps in the current understanding of BMP structures, with the aim that discussion of these gaps will lead to advancements in the field.
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Affiliation(s)
- Gregory R Gipson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Erich J Goebel
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Kaitlin N Hart
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Emily C Kappes
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Chandramohan Kattamuri
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Jason C McCoy
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Medical Sciences Building, Cincinnati, OH 45267, USA.
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Walpurgis K, Weigand T, Knoop A, Thomas A, Reichel C, Dellanna F, Thevis M. Detection of follistatin-based inhibitors of the TGF-β signaling pathways in serum/plasma by means of LC-HRMS/MS and Western blotting. Drug Test Anal 2020; 12:1636-1648. [PMID: 32959984 DOI: 10.1002/dta.2925] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/08/2020] [Accepted: 08/30/2020] [Indexed: 01/06/2023]
Abstract
Cytokines of the transforming growth factor beta (TGF-β) superfamily such as myostatin and activin A are considered as key regulators of skeletal muscle mass. In vivo, their activity is controlled by different binding proteins such as follistatin (FST), whose interaction with the circulating growth factors prevents activation of the activin type II receptors. FST-based protein therapeutics are therefore not only promising drug candidates for the treatment of muscular diseases but also potential performance-enhancing agents in sports. Within this study, two complementary detection assays for FST-based inhibitors of the TGF-β signaling pathways in doping control serum and plasma samples were developed by using both monomeric FST and dimeric FST-Fc fusion proteins as model compounds. The initial testing procedure is based on immunoaffinity purification, tryptic digestion, and LC-HRMS/MS, offering high specificity by targeting tryptic signature peptides of FST. As the glycoprotein is also produced endogenously, the confirmation method employs immunoaffinity purification, sodium dodecyl sulfate polyacrylamide gel electrophoresis, and Western blotting in order to detect the intact proteins and differentiate synthetic FST-Fc constructs from naturally occurring FST isoforms. Both assays were found to be highly specific with an estimated detection limit of 10 ng/ml. Moreover, a commercial sandwich enzyme-linked immunosorbent assay was used to determine endogenous FST values. The detected FST serum levels of healthy volunteers were found below 5 ng/ml, which is in accordance with reference values from the literature and below the doping control detection methods' limit of detection (LOD). The presented assays expand the range of available tests for emerging doping agents, and the initial testing procedure can readily be modified to include further protein drugs.
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Affiliation(s)
- Katja Walpurgis
- Center for Preventive Doping Research/Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Tim Weigand
- Center for Preventive Doping Research/Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Andre Knoop
- Center for Preventive Doping Research/Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Andreas Thomas
- Center for Preventive Doping Research/Institute of Biochemistry, German Sport University Cologne, Cologne, Germany
| | - Christian Reichel
- Doping Control Laboratory, AIT Seibersdorf Laboratories, Seibersdorf, Austria
| | - Frank Dellanna
- Fresenius University of Applied Sciences, Cologne, Germany
| | - Mario Thevis
- Center for Preventive Doping Research/Institute of Biochemistry, German Sport University Cologne, Cologne, Germany.,European Monitoring Center for Emerging Doping Agents (EuMoCEDA), Cologne/Bonn, Germany
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10
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Suh J, Lee YS. Myostatin Inhibitors: Panacea or Predicament for Musculoskeletal Disorders? J Bone Metab 2020; 27:151-165. [PMID: 32911580 PMCID: PMC7571243 DOI: 10.11005/jbm.2020.27.3.151] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 06/23/2020] [Indexed: 01/19/2023] Open
Abstract
Myostatin, also known as growth differentiation factor 8 (GDF8), is a transforming growth factor-β (TGF-β) family member that functions to limit skeletal muscle growth. Accordingly, loss-of-function mutations in myostatin result in a dramatic increase in muscle mass in humans and various animals, while its overexpression leads to severe muscle atrophy. Myostatin also exerts a significant effect on bone metabolism, as demonstrated by enhanced bone mineral density and bone regeneration in myostatin null mice. The identification of myostatin as a negative regulator of muscle and bone mass has sparked an enormous interest in developing myostatin inhibitors as therapeutic agents for treating a variety of clinical conditions associated with musculoskeletal disorders. As a result, various myostatin-targeting strategies involving antibodies, myostatin propeptides, soluble receptors, and endogenous antagonists have been generated, and many of them have progressed to clinical trials. Importantly, most myostatin inhibitors also repress the activities of other closely related TGF-β family members including GDF11, activins, and bone morphogenetic proteins (BMPs), increasing the potential for unwanted side effects, such as vascular side effects through inhibition of BMP 9/10 and bone weakness induced by follistatin through antagonizing several TGF-β family members. Therefore, a careful distinction between targets that may enhance the efficacy of an agent and those that may cause adverse effects is required with the improvement of the target specificity. In this review, we discuss the current understanding of the endogenous function of myostatin, and provide an overview of clinical trial outcomes from different myostatin inhibitors.
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Affiliation(s)
- Joonho Suh
- Department of Molecular Genetics and Dental Pharmacology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Yun-Sil Lee
- Department of Molecular Genetics and Dental Pharmacology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
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11
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Woodruff TK. Lessons from bioengineering the ovarian follicle: a personal perspective. Reproduction 2020; 158:F113-F126. [PMID: 31846436 DOI: 10.1530/rep-19-0190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/15/2019] [Indexed: 12/14/2022]
Abstract
The ovarian follicle and its maturation captivated my imagination and inspired my scientific journey - what we know now about this remarkable structure is captured in this invited review. In the past decade, our knowledge of the ovarian follicle expanded dramatically as cross-disciplinary collaborations brought new perspectives to bear, ultimately leading to the development of extragonadal follicles as model systems with significant clinical implications. Follicle maturation in vitro in an 'artificial' ovary became possible by learning what the follicle is fundamentally and autonomously capable of - which turns out to be quite a lot. Progress in understanding and harnessing follicle biology has been aided by engineers and materials scientists who created hardware that enables tissue function for extended periods of time. The EVATAR system supports extracorporeal ovarian function in an engineered environment that mimics the endocrine environment of the reproductive tract. Finally, applying the tools of inorganic chemistry, we discovered that oocytes require zinc to mature over time - a truly new aspect of follicle biology with no antecedent other than the presence of zinc in sperm. Drawing on the tools and ideas from the fields of bioengineering, materials science and chemistry unlocked follicle biology in ways that we could not have known or even predicted. Similarly, how today's basic science discoveries regarding ovarian follicle maturation are translated to improve the experience of tomorrow's patients is yet to be determined.
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Affiliation(s)
- Teresa K Woodruff
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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12
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Sylow L, Vind BF, Kruse R, Møller PM, Wojtaszewski JFP, Richter EA, Højlund K. Circulating Follistatin and Activin A and Their Regulation by Insulin in Obesity and Type 2 Diabetes. J Clin Endocrinol Metab 2020; 105:5766434. [PMID: 32112102 DOI: 10.1210/clinem/dgaa090] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 02/25/2020] [Indexed: 01/04/2023]
Abstract
BACKGROUND Circulating follistatin (Fst) binds activin A and thereby regulates biological functions such as muscle growth and β-cell survival. However, Fst and activin A's implication in metabolic regulation is unclear. OBJECTIVE To investigate circulating Fst and activin A in obesity and type 2 diabetes (T2D) and determine their association with metabolic parameters. Further, to examine regulation of Fst and activin A by insulin and the influence of obesity and T2D hereon. METHODS Plasma Fst and activin A levels were analyzed in obese T2D patients (N = 10) closely matched to glucose-tolerant lean (N = 12) and obese (N = 10) individuals in the fasted state and following a 4-h hyperinsulinemic-euglycemic clamp (40 mU·m-2·min-1) combined with indirect calorimetry. RESULTS Circulating Fst was ~30% higher in patients with T2D compared with both lean and obese nondiabetic individuals (P < .001), while plasma activin A was unaltered. In the total cohort, fasting plasma Fst correlated positively with fasting plasma glucose, serum insulin and C-peptide levels, homeostasis model assessment of insulin resistance, and hepatic and adipose tissue insulin resistance after adjusting for age, gender and group (all r > 0.47; P < .05). However, in the individual groups these correlations only achieved significance in patients with T2D (not plasma glucose). Acute hyperinsulinemia at euglycemia reduced circulating Fst by ~30% (P < .001) and this response was intact in patients with T2D. Insulin inhibited FST expression in human hepatocytes after 2 h and even further after 48 h. CONCLUSIONS Elevated circulating Fst, but not activin A, is strongly associated with measures of insulin resistance in patients with T2D. However, the ability of insulin to suppress circulating Fst is preserved in T2D.
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Affiliation(s)
- Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte F Vind
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
| | - Rikke Kruse
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
| | - Pauline M Møller
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kurt Højlund
- Steno Diabetes Center Odense, Odense University Hospital, Odense, Denmark
- Department of Clinical Research, University of Southern Denmark, Odense C, Denmark
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13
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Analysis of the inhibiting activity of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) on matrix metalloproteinases. Sci Rep 2020; 10:6317. [PMID: 32286475 PMCID: PMC7156630 DOI: 10.1038/s41598-020-63338-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/30/2020] [Indexed: 12/26/2022] Open
Abstract
Matrix metalloproteinases (MMPs) occur in 23 human paralogues with key functions in physiology, and their activity is controlled by protein inhibitors. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), which is essential for embryogenesis and tumour suppression, has been reported to inhibit MMPs. Here, we developed eukaryotic and bacterial expression systems for different RECK variants and analysed their inhibitory capacity against representative MMPs in vitro. We could not detect any significant inhibition. Instead, we found that partially purified RECK from the conditioned medium of transfected Expi293F cells but not that of ExpiCHO-S or Drosophila Schneider cells contained a contaminant with proteolytic activity. The contaminant was removed through treatment with a small-molecule serine peptidase inhibitor and additional chromatographic purification. A tantamount contaminant was further detected in an equivalent expression system of the N-terminal fragment of the proteoglycan testican 3, but not in those of two other proteins. These results indicate that previous reports of inhibitory activity of recombinant RECK on MMPs, which were performed with partially purified samples, were probably masked by a coeluting contaminant present in the supernatant of HEK293-derived cells. Thus, RECK is probably not a direct inhibitor of MMP catalytic activity but may still regulate MMPs through other mechanisms.
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14
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Yu M, Xiao L, Chen Y, Wang H, Gao Y, Wang A. Identification of a potential target for treatment of squamous cell carcinoma of the tongue: follistatin. Br J Oral Maxillofac Surg 2020; 58:437-442. [PMID: 32115303 DOI: 10.1016/j.bjoms.2020.01.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 01/29/2020] [Indexed: 11/24/2022]
Abstract
Squamous cell carcinoma (SCC) of the tongue is the most common oral cancer and is prone to develop regional lymph nodes and distant metastases. Reliable and stable therapeutic targets can improve the curative effect and reduce toxic side effects caused by traditional treatments such as surgery, radiotherapy, and chemotherapy. We have analysed three sets of series of functional gene expression of SCC of the tongue from gene expression omnibus (GEO) datasets, and 154 common differentially expressed genes (DEG) between SCC of the tongue and the corresponding normal tissues were screened. Further bioinformatics research that was based on the data from the Cancer genome atlas, Gene ontology, and the Kyoto encyclopaedia of genes and genomes indicated that the increased expression of follistatin might be correlated with a poor prognosis in these patients. By assay of colony formation, reverse transcription polymerase chain reaction (RT-PCR), western blotting, immunohistochemical staining, and lentivirus transfection, we confirmed that downregulation of follistatin inhibited the proliferation of SCC cells in the tongue.
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Affiliation(s)
- M Yu
- Department of Oral and Maxillofacial Surgery, Guangzhou Women and Children's Medical Center, Guangzhou, China.
| | - L Xiao
- Department of Periodontology, Haizhu Square Hospital, Stomatological Hospital of Southern Medical University
| | - Y Chen
- Department of Oral and Maxillofacial Surgery, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - H Wang
- Department of Oral and Maxillofacial Surgery, Guangzhou Women and Children's Medical Center, Guangzhou, China
| | - Y Gao
- Department of Stomatology, Longgang Central Hospital of Shenzhen, Shenzhen, China
| | - A Wang
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
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15
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Goebel EJ, Hart KN, McCoy JC, Thompson TB. Structural biology of the TGFβ family. Exp Biol Med (Maywood) 2019; 244:1530-1546. [PMID: 31594405 DOI: 10.1177/1535370219880894] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The transforming growth factor beta (TGFβ) signaling pathway orchestrates a wide breadth of biological processes, ranging from bone development to reproduction. Given this, there has been a surge of interest from the drug development industry to modulate the pathway – at several points. This review discusses and provides additional context for several layers of the TGFβ signaling pathway from a structural biology viewpoint. The combination of structural techniques coupled with biophysical studies has provided a foundational knowledge of the molecular mechanisms governing this high impact, ubiquitous pathway, underlying many of the current therapeutic pursuits. This work seeks to consolidate TGFβ-related structural knowledge and educate other researchers of the apparent gaps that still prove elusive. We aim to highlight the importance of these structures and provide the contextual information to understand the contribution to the field, with the hope of advancing the discussion and exploration of the TGFβ signaling pathway. Impact statement The transforming growth factor beta (TGFβ) signaling pathway is a multifacetted and highly regulated pathway, forming the underpinnings of a large range of biological processes. Here, we review and consolidate the key steps in TGFβ signaling using literature rooted in structural and biophysical techniques, with a focus on molecular mechanisms and gaps in knowledge. From extracellular regulation to ligand–receptor interactions and intracellular activation cascades, we hope to provide an introductory base for understanding the TGFβ pathway as a whole.
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Affiliation(s)
- Erich J Goebel
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Kaitlin N Hart
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jason C McCoy
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45267, USA
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16
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Wijayarathna R, Hedger MP. Activins, follistatin and immunoregulation in the epididymis. Andrology 2019; 7:703-711. [DOI: 10.1111/andr.12682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/18/2019] [Accepted: 06/25/2019] [Indexed: 12/21/2022]
Affiliation(s)
- R. Wijayarathna
- Centre for Reproductive Health Hudson Institute of Medical Research Clayton Vic. Australia
- Department of Molecular and Translational Sciences School of Clinical Sciences Monash University Clayton Vic. Australia
| | - M. P. Hedger
- Centre for Reproductive Health Hudson Institute of Medical Research Clayton Vic. Australia
- Department of Molecular and Translational Sciences School of Clinical Sciences Monash University Clayton Vic. Australia
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17
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Castonguay R, Lachey J, Wallner S, Strand J, Liharska K, Watanabe AE, Cannell M, Davies MV, Sako D, Troy ME, Krishnan L, Mulivor AW, Li H, Keates S, Alexander MJ, Pearsall RS, Kumar R. Follistatin-288-Fc Fusion Protein Promotes Localized Growth of Skeletal Muscle. J Pharmacol Exp Ther 2018; 368:435-445. [PMID: 30563942 DOI: 10.1124/jpet.118.252304] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 12/06/2018] [Indexed: 12/19/2022] Open
Abstract
Follistatin is an endogenous glycoprotein that promotes growth and repair of skeletal muscle by sequestering inhibitory ligands of the transforming growth factor-β superfamily and may therefore have therapeutic potential for neuromuscular diseases. Here, we sought to determine the suitability of a newly engineered follistatin fusion protein (FST288-Fc) to promote localized, rather than systemic, growth of skeletal muscle by capitalizing on the intrinsic heparin-binding ability of the follistatin-288 isoform. As determined by surface plasmon resonance and cell-based assays, FST288-Fc binds to activin A, activin B, myostatin (growth differentiation factor GDF8), and GDF11 with high affinity and neutralizes their activity in vitro. Intramuscular administration of FST288-Fc in mice induced robust, dose-dependent growth of the targeted muscle but not of surrounding or contralateral muscles, in contrast to the systemic effects of a locally administered fusion protein incorporating activin receptor type IIB (ActRIIB-Fc). Furthermore, systemic administration of FST288-Fc in mice did not alter muscle mass or body composition as determined by NMR, which again contrasts with the pronounced systemic activity of ActRIIB-Fc when administered by the same route. Subsequent analysis revealed that FST288-Fc in the circulation undergoes rapid proteolysis, thereby restricting its activity to individual muscles targeted by intramuscular administration. These results indicate that FST288-Fc can produce localized growth of skeletal muscle in a targeted manner with reduced potential for undesirable systemic effects. Thus, FST288-Fc and similar agents may be beneficial in the treatment of disorders with muscle atrophy that is focal, asymmetric, or otherwise heterogeneous.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Huiming Li
- Acceleron Pharma, Cambridge, Massachusetts
| | | | | | | | - Ravi Kumar
- Acceleron Pharma, Cambridge, Massachusetts
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18
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Iskenderian A, Liu N, Deng Q, Huang Y, Shen C, Palmieri K, Crooker R, Lundberg D, Kastrapeli N, Pescatore B, Romashko A, Dumas J, Comeau R, Norton A, Pan J, Rong H, Derakhchan K, Ehmann DE. Myostatin and activin blockade by engineered follistatin results in hypertrophy and improves dystrophic pathology in mdx mouse more than myostatin blockade alone. Skelet Muscle 2018; 8:34. [PMID: 30368252 PMCID: PMC6204036 DOI: 10.1186/s13395-018-0180-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 10/14/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Myostatin antagonists are being developed as therapies for Duchenne muscular dystrophy due to their strong hypertrophic effects on skeletal muscle. Engineered follistatin has the potential to combine the hypertrophy of myostatin antagonism with the anti-inflammatory and anti-fibrotic effects of activin A antagonism. METHODS Engineered follistatin was administered to C57BL/6 mice for 4 weeks, and muscle mass and myofiber size was measured. In the mdx model, engineered follistatin was dosed for 12 weeks in two studies comparing to an Fc fusion of the activin IIB receptor or an anti-myostatin antibody. Functional measurements of grip strength and tetanic force were combined with tissue analysis for markers of necrosis, inflammation, and fibrosis to evaluate improvement in dystrophic pathology. RESULTS In wild-type and mdx mice, dose-dependent increases in muscle mass and quadriceps myofiber size were observed for engineered follistatin. In mdx, increases in grip strength and tetanic force were combined with improvements in muscle markers for necrosis, inflammation, and fibrosis. Improvements in dystrophic pathology were greater for engineered follistatin than the anti-myostatin antibody. CONCLUSIONS Engineered follistatin generated hypertrophy and anti-fibrotic effects in the mdx model.
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Affiliation(s)
- Andrea Iskenderian
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Nan Liu
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Qingwei Deng
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Yan Huang
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Chuan Shen
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Kathleen Palmieri
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Robert Crooker
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Dianna Lundberg
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Niksa Kastrapeli
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Brian Pescatore
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Alla Romashko
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - John Dumas
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Robert Comeau
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Angela Norton
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Jing Pan
- Discovery Therapeutics, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Haojing Rong
- Nonclinical Development, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - Katayoun Derakhchan
- Nonclinical Development, Shire Pharmaceuticals, Lexington, MA, USA.,Drug Discovery, Shire, Cambridge, MA, USA
| | - David E Ehmann
- Research, Shire Pharmaceuticals, Lexington, MA, 02421, USA. .,Drug Discovery, Shire, Cambridge, MA, USA.
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19
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Schumann C, Nguyen DX, Norgard M, Bortnyak Y, Korzun T, Chan S, Lorenz AS, Moses AS, Albarqi HA, Wong L, Michaelis K, Zhu X, Alani AWG, Taratula OR, Krasnow S, Marks DL, Taratula O. Increasing lean muscle mass in mice via nanoparticle-mediated hepatic delivery of follistatin mRNA. Am J Cancer Res 2018; 8:5276-5288. [PMID: 30555546 PMCID: PMC6276093 DOI: 10.7150/thno.27847] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 10/02/2018] [Indexed: 12/12/2022] Open
Abstract
Muscle atrophy occurs during chronic diseases, resulting in diminished quality of life and compromised treatment outcomes. There is a high demand for therapeutics that increase muscle mass while abrogating the need for special dietary and exercise requirements. Therefore, we developed an efficient nanomedicine approach capable of increasing muscle mass. Methods: The therapy is based on nanoparticle-mediated delivery of follistatin messenger RNA (mRNA) to the liver after subcutaneous administration. The delivered mRNA directs hepatic cellular machinery to produce follistatin, a glycoprotein that increases lean mass through inhibition of negative regulators of muscle mass (myostatin and activin A). These factors are elevated in numerous disease states, thereby providing a target for therapeutic intervention. Results: Animal studies validated that mRNA-loaded nanoparticles enter systemic circulation following subcutaneous injection, accumulate and internalize in the liver, where the mRNA is translated into follistatin. Follistatin serum levels were elevated for 72 h post injection and efficiently reduced activin A and myostatin serum concentrations. After eight weeks of repeated injections, the lean mass of mice in the treatment group was ~10% higher when compared to that of the controls. Conclusion: Based on the obtained results demonstrating an increased muscle mass as well as restricted fat accumulation, this nanoplatform might be a milestone in the development of mRNA technologies and the treatment of muscle wasting disorders.
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20
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Nicolas N, Muir JA, Hayward S, Chen JL, Stanton PG, Gregorevic P, de Kretser DM, Loveland KL, Bhushan S, Meinhardt A, Fijak M, Hedger MP. Induction of experimental autoimmune orchitis in mice: responses to elevated circulating levels of the activin-binding protein, follistatin. Reproduction 2017; 154:293-305. [PMID: 28667125 DOI: 10.1530/rep-17-0010] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 06/22/2017] [Accepted: 06/30/2017] [Indexed: 12/20/2022]
Abstract
Experimental autoimmune orchitis (EAO) is a rodent model of chronic testicular inflammation that mimics the pathology observed in some types of human infertility. In a previous study, testicular expression of the inflammatory/immunoregulatory cytokine, activin A, was elevated in adult mice during the onset of EAO, indicating a potential role in the regulation of the disease. Consequently, we examined the development of EAO in mice with elevated levels of follistatin, an endogenous activin antagonist, as a potential therapeutic approach to testicular inflammation. Prior to EAO induction, mice received a single intramuscular injection of a non-replicative recombinant adeno-associated viral vector carrying a gene cassette of the circulating form of follistatin, FST315 (FST group). Serum follistatin levels were increased 5-fold in the FST group compared with the control empty vector (EV) group at 30 and 50 days of EAO, but intra-testicular levels of follistatin or activin A were not significantly altered. Induction of EAO was reduced, but not prevented, with mild-to-severe damage in 75% of the EV group and 40% of the FST group, at 50 days following immunisation with testicular homogenate. However, the EAO damage score (based on disruption of the blood-testis barrier, apoptosis, testicular damage and fibrosis) and extent of intratesticular inflammation (expression of inflammatory mediators) were directly proportional to the levels of activin A measured in the testis at 50 days. These data implicate activin A in the progression of EAO, thereby providing a potential therapeutic target; however, elevating circulating follistatin levels were not sufficient to prevent EAO development.
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Affiliation(s)
- Nour Nicolas
- Department of Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany.,Hudson Institute of Medical Research, Clayton, Australia
| | - Julie A Muir
- Hudson Institute of Medical Research, Clayton, Australia
| | - Susan Hayward
- Hudson Institute of Medical Research, Clayton, Australia
| | - Justin L Chen
- Hudson Institute of Medical Research, Clayton, Australia.,Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | | | - Paul Gregorevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - David M de Kretser
- Hudson Institute of Medical Research, Clayton, Australia.,Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Kate L Loveland
- Hudson Institute of Medical Research, Clayton, Australia.,School of Clinical Sciences, Monash University, Melbourne, Australia
| | - Sudhanshu Bhushan
- Department of Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany
| | - Andreas Meinhardt
- Department of Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany.,Hudson Institute of Medical Research, Clayton, Australia
| | - Monika Fijak
- Department of Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany
| | - Mark P Hedger
- Hudson Institute of Medical Research, Clayton, Australia.,Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
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21
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Forrester HB, de Kretser DM, Leong T, Hagekyriakou J, Sprung CN. Follistatin attenuates radiation-induced fibrosis in a murine model. PLoS One 2017; 12:e0173788. [PMID: 28301516 PMCID: PMC5354399 DOI: 10.1371/journal.pone.0173788] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 02/27/2017] [Indexed: 02/06/2023] Open
Abstract
Purpose Fibrosis can be a disabling, severe side effect of radiotherapy that can occur in patients, and for which there is currently no effective treatment. The activins, proteins which are members of the TGFβ superfamily, have a major role in stimulating the inflammatory response and subsequent fibrosis. Follistatin is an endogenous protein that binds the activins virtually irreversibly and inhibits their actions. These studies test if follistatin can attenuate the fibrotic response using a murine model of radiation-induced fibrosis. Experimental design C57BL/6 mice were subcutaneously injected with follistatin 24 hours prior to irradiation. Mice were irradiated in a 10 x 10 mm square area of the right hind leg with 35 Gy and were given follistatin 24 hours before radiation and three times a week for six months following. Leg extension was measured, and tissue was collected for histological and molecular analysis to evaluate the progression of the radiation-induced fibrosis. Results Leg extension was improved in follistatin treated mice compared to vehicle treated mice at six months after irradiation. Also, epidermal thickness and cell nucleus area of keratinocytes were decreased by the follistatin treatment compared to the cells in irradiated skin of control mice. Finally, the gene expression of transforming growth factor β1 (Tgfb1), and smooth muscle actin (Acta2) were decreased in the irradiated skin and Acta2 and inhibin βA subunit (Inhba) were decreased in the irradiated muscle of the follistatin treated mice. Conclusions Follistatin attenuated the radiation-induced fibrotic response in irradiated mice. These studies provide the data to support further investigation of the use of follistatin to reduce radiation-induced fibrosis in patients undergoing radiotherapy for cancer.
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Affiliation(s)
- Helen B. Forrester
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
| | - David M. de Kretser
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia
| | - Trevor Leong
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Jim Hagekyriakou
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Carl N. Sprung
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Science, Monash University, Clayton, Victoria, Australia
- * E-mail:
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22
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Walker RG, Czepnik M, Goebel EJ, McCoy JC, Vujic A, Cho M, Oh J, Aykul S, Walton KL, Schang G, Bernard DJ, Hinck AP, Harrison CA, Martinez-Hackert E, Wagers AJ, Lee RT, Thompson TB. Structural basis for potency differences between GDF8 and GDF11. BMC Biol 2017; 15:19. [PMID: 28257634 PMCID: PMC5336696 DOI: 10.1186/s12915-017-0350-1] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/18/2017] [Indexed: 01/11/2023] Open
Abstract
Background Growth/differentiation factor 8 (GDF8) and GDF11 are two highly similar members of the transforming growth factor β (TGFβ) family. While GDF8 has been recognized as a negative regulator of muscle growth and differentiation, there are conflicting studies on the function of GDF11 and whether GDF11 has beneficial effects on age-related dysfunction. To address whether GDF8 and GDF11 are functionally identical, we compared their signaling and structural properties. Results Here we show that, despite their high similarity, GDF11 is a more potent activator of SMAD2/3 and signals more effectively through the type I activin-like receptor kinase receptors ALK4/5/7 than GDF8. Resolution of the GDF11:FS288 complex, apo-GDF8, and apo-GDF11 crystal structures reveals unique properties of both ligands, specifically in the type I receptor binding site. Lastly, substitution of GDF11 residues into GDF8 confers enhanced activity to GDF8. Conclusions These studies identify distinctive structural features of GDF11 that enhance its potency, relative to GDF8; however, the biological consequences of these differences remain to be determined. Electronic supplementary material The online version of this article (doi:10.1186/s12915-017-0350-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ryan G Walker
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Magdalena Czepnik
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Erich J Goebel
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Jason C McCoy
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Ana Vujic
- Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Miook Cho
- Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA.,Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02115, USA
| | - Juhyun Oh
- Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA.,Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02115, USA
| | - Senem Aykul
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Kelly L Walton
- Hudson Institute of Medical Research, Clayton, Australia.,Department of Physiology, Monash University, Clayton, Australia
| | - Gauthier Schang
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Daniel J Bernard
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Andrew P Hinck
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, USA
| | - Craig A Harrison
- Hudson Institute of Medical Research, Clayton, Australia.,Department of Physiology, Monash University, Clayton, Australia
| | - Erik Martinez-Hackert
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Amy J Wagers
- Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA.,Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA, 02115, USA
| | - Richard T Lee
- Harvard Stem Cell Institute and Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Thomas B Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH, 45267, USA. .,University of Cincinnati, 231 Albert Sabin Way ML 0524, Cincinnati, OH, 45267, USA.
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23
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Testicular activin and follistatin levels are elevated during the course of experimental autoimmune epididymo-orchitis in mice. Sci Rep 2017; 7:42391. [PMID: 28205525 PMCID: PMC5304336 DOI: 10.1038/srep42391] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 01/10/2017] [Indexed: 12/26/2022] Open
Abstract
Experimental autoimmune epididymo-orchitis (EAEO) is a model of chronic inflammation, induced by immunisation with testicular antigens, which reproduces the pathology of some types of human infertility. Activins A and B regulate spermatogenesis and steroidogenesis, but are also pro-inflammatory, pro-fibrotic cytokines. Expression of the activins and their endogenous antagonists, inhibin and follistatin, was examined in murine EAEO. Adult untreated and adjuvant-treated control mice showed no pathology. All mice immunised with testis antigens developed EAEO by 50 days, characterised by loss of germ cells, immune cell infiltration and fibrosis in the testis, similar to biopsies from human inflamed testis. An increase of total CD45+ leukocytes, comprising CD3+ T cells, CD4 + CD8− and CD4 + CD25+ T cells, and a novel population of CD4 + CD8+ double positive T cells was also detected in EAEO testes. This was accompanied by increased expression of TNF, MCP-1 and IL-10. Activin A and B and follistatin protein levels were elevated in EAEO testes, with peak activin expression during the active phase of the disease, whereas mRNA expression of the inhibin B subunits (Inha and Inhbb) and activin receptor subunits (Acvr1b and Acvr2b) were downregulated. These data suggest that activin–follistatin regulation may play a role during the development of EAEO.
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24
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Shi L, Resaul J, Owen S, Ye L, Jiang WG. Clinical and Therapeutic Implications of Follistatin in Solid Tumours. Cancer Genomics Proteomics 2017; 13:425-435. [PMID: 27807065 DOI: 10.21873/cgp.20005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 10/05/2016] [Indexed: 12/20/2022] Open
Abstract
Follistatin (FST), as a single-chain glycosylated protein, has two major isoforms, FST288 and FST315. The FST315 isoform is the predominant form whilst the FST288 variant accounts for less than 5% of the encoded mRNA. FST is differentially expressed in human tissues and aberrant expression has been observed in a variety of solid tumours, including gonadal, gastric and lung cancer, hepatocellular carcinoma, basal cell carcinoma and melanoma. Based on the current evidence, FST is an antagonist of transforming growth factor beta family members, such as activin and bone morphogenetic proteins (BMPs). FST plays a role in tumourigenesis, metastasis and angiogenesis of solid tumours through its interaction with activin and BMPs, thus resulting in pathophysiological function. In terms of diagnosis, prognosis and therapy, FST has shown strong promise. Through a better understanding of its biological functions, potential clinical applications may yet emerge.
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Affiliation(s)
- Lei Shi
- Urology Department, Yantai Yu Huang Ding Hospital, Yantai, Shandong Province, P.R. China.,Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, U.K
| | - Jeyna Resaul
- Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, U.K
| | - Sioned Owen
- Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, U.K
| | - Lin Ye
- Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, U.K
| | - Wen G Jiang
- Cardiff China Medical Research Collaborative, Division of Cancer and Genetics, Cardiff University School of Medicine, Cardiff, U.K.
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Abstract
We review the evolution and structure of members of the transforming growth factor β (TGF-β) family, antagonistic or agonistic modulators, and receptors that regulate TGF-β signaling in extracellular environments. The growth factor (GF) domain common to all family members and many of their antagonists evolved from a common cystine knot growth factor (CKGF) domain. The CKGF superfamily comprises six distinct families in primitive metazoans, including the TGF-β and Dan families. Compared with Wnt/Frizzled and Notch/Delta families that also specify body axes, cell fate, tissues, and other families that contain CKGF domains that evolved in parallel, the TGF-β family was the most fruitful in evolution. Complexes between the prodomains and GFs of the TGF-β family suggest a new paradigm for regulating GF release by conversion from closed- to open-arm procomplex conformations. Ternary complexes of the final step in extracellular signaling show how TGF-β GF dimers bind type I and type II receptors on the cell surface, and enable understanding of much of the specificity and promiscuity in extracellular signaling. However, structures suggest that when GFs bind repulsive guidance molecule (RGM) family coreceptors, type I receptors do not bind until reaching an intracellular, membrane-enveloped compartment, blurring the line between extra- and intracellular signaling. Modulator protein structures show how structurally diverse antagonists including follistatins, noggin, and members of the chordin family bind GFs to regulate signaling; complexes with the Dan family remain elusive. Much work is needed to understand how these molecular components assemble to form signaling hubs in extracellular environments in vivo.
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Affiliation(s)
- Andrew P Hinck
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Thomas D Mueller
- Department of Plant Physiology and Biophysics, Julius-von-Sachs Institute of the University Wuerzburg, D-97082 Wuerzburg, Germany
| | - Timothy A Springer
- Program in Cellular and Molecular Medicine and Division of Hematology, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts 02115
- Department of Biological Chemistry and Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
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Hansen JS, Plomgaard P. Circulating follistatin in relation to energy metabolism. Mol Cell Endocrinol 2016; 433:87-93. [PMID: 27264073 DOI: 10.1016/j.mce.2016.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 05/25/2016] [Accepted: 06/01/2016] [Indexed: 12/18/2022]
Abstract
Recently, substantial evidence has emerged that the liver contributes significantly to the circulating levels of follistatin and that circulating follistatin is tightly regulated by the glucagon-to-insulin ratio. Both observations are based on investigations of healthy subjects. These novel findings challenge the present view of circulating follistatin in human physiology, being that circulating follistatin is a result of spill-over from para/autocrine actions in various tissues and cells. Follistatin as a liver-derived protein under the regulation of glucagon-to-insulin ratio suggests a relation to energy metabolism. In this narrative review, we attempt to reconcile the existing findings on circulating follistatin with the novel concept that circulating follistatin is a liver-derived molecule regulated by the glucagon-to-insulin ratio. The picture emerging is that conditions associated with elevated levels of circulating follistatin have a metabolic denominator with decreased insulin sensitivity and/or hyperglucagoneimia.
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Affiliation(s)
- Jakob Schiøler Hansen
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark; The Centre of Inflammation and Metabolism, Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Denmark
| | - Peter Plomgaard
- Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark; The Centre of Inflammation and Metabolism, Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Denmark.
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Wang X, Fischer G, Hyvönen M. Structure and activation of pro-activin A. Nat Commun 2016; 7:12052. [PMID: 27373274 PMCID: PMC4932183 DOI: 10.1038/ncomms12052] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 05/24/2016] [Indexed: 12/19/2022] Open
Abstract
Activins are growth factors with multiple roles in the development and homeostasis. Like all TGF-β family of growth factors, activins are synthesized as large precursors from which mature dimeric growth factors are released proteolytically. Here we have studied the activation of activin A and determined crystal structures of the unprocessed precursor and of the cleaved pro-mature complex. Replacing the natural furin cleavage site with a HRV 3C protease site, we show how the protein gains its bioactivity after proteolysis and is as active as the isolated mature domain. The complex remains associated in conditions used for biochemical analysis with a dissociation constant of 5 nM, but the pro-domain can be actively displaced from the complex by follistatin. Our high-resolution structures of pro-activin A share features seen in the pro-TGF-β1 and pro-BMP-9 structures, but reveal a new oligomeric arrangement, with a domain-swapped, cross-armed conformation for the protomers in the dimeric protein. Activins are members of the TGF-β family of growth factors that are processed from precursors into the mature proteins. Here, the authors use structural biology and biochemistry to examine the protein domain organisation and gain insights into the activation of pro-activin A.
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Affiliation(s)
- Xuelu Wang
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Gerhard Fischer
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
| | - Marko Hyvönen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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28
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Structure of Gremlin-1 and analysis of its interaction with BMP-2. Biochem J 2016; 473:1593-604. [PMID: 27036124 PMCID: PMC4888461 DOI: 10.1042/bcj20160254] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/01/2016] [Indexed: 11/17/2022]
Abstract
We have determined the crystal structure of Gremlin-1 and analysed its interaction with BMP-2. Our results suggest that Gremlin-1 does not inhibit BMP-2 by direct 1:1 binding, but possibly has a novel mechanism of sequestering BMP-2 into a larger oligomeric complex. Bone morphogenetic protein 2 (BMP-2) is a member of the transforming growth factor-β (TGF-β) signalling family and has a very broad biological role in development. Its signalling is regulated by many effectors: transmembrane proteins, membrane-attached proteins and soluble secreted antagonists such as Gremlin-1. Very little is known about the molecular mechanism by which Gremlin-1 and other DAN (differential screening-selected gene aberrative in neuroblastoma) family proteins inhibit BMP signalling. We analysed the interaction of Gremlin-1 with BMP-2 using a range of biophysical techniques, and used mutagenesis to map the binding site on BMP-2. We have also determined the crystal structure of Gremlin-1, revealing a similar conserved dimeric structure to that seen in other DAN family inhibitors. Measurements using biolayer interferometry (BLI) indicate that Gremlin-1 and BMP-2 can form larger complexes, beyond the expected 1:1 stoichiometry of dimers, forming oligomers that assemble in alternating fashion. These results suggest that inhibition of BMP-2 by Gremlin-1 occurs by a mechanism that is distinct from other known inhibitors such as Noggin and Chordin and we propose a novel model of BMP-2–Gremlin-1 interaction yet not seen among any BMP antagonists, and cannot rule out that several different oligomeric states could be found, depending on the concentration of the two proteins.
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Wijayarathna R, de Kretser DM. Activins in reproductive biology and beyond. Hum Reprod Update 2016; 22:342-57. [PMID: 26884470 DOI: 10.1093/humupd/dmv058] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/20/2015] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Activins are members of the pleiotrophic family of the transforming growth factor-beta (TGF-β) superfamily of cytokines, initially isolated for their capacity to induce the release of FSH from pituitary extracts. Subsequent research has demonstrated that activins are involved in multiple biological functions including the control of inflammation, fibrosis, developmental biology and tumourigenesis. This review summarizes the current knowledge on the roles of activin in reproductive and developmental biology. It also discusses interesting advances in the field of modulating the bioactivity of activins as a therapeutic target, which would undoubtedly be beneficial for patients with reproductive pathology. METHODS A comprehensive literature search was carried out using PUBMED and Google Scholar databases to identify studies in the English language which have contributed to the advancement of the field of activin biology, since its initial isolation in 1987 until July 2015. 'Activin', 'testis', 'ovary', 'embryonic development' and 'therapeutic targets' were used as the keywords in combination with other search phrases relevant to the topic of activin biology. RESULTS Activins, which are dimers of inhibin β subunits, act via a classical TGF-β signalling pathway. The bioactivity of activin is regulated by two endogenous inhibitors, inhibin and follistatin. Activin is a major regulator of testicular and ovarian development. In the ovary, activin A promotes oocyte maturation and regulates granulosa cell steroidogenesis. It is also essential in endometrial repair following menstruation, decidualization and maintaining pregnancy. Dysregulation of the activin-follistatin-inhibin system leads to disorders of female reproduction and pregnancy, including polycystic ovary syndrome, ectopic pregnancy, miscarriage, fetal growth restriction, gestational diabetes, pre-eclampsia and pre-term birth. Moreover, a rise in serum activin A, accompanied by elevated FSH, is characteristic of female reproductive aging. In the male, activin A is an autocrine and paracrine modulator of germ cell development and Sertoli cell proliferation. Disruption of normal activin signalling is characteristic of many tumours affecting reproductive organs, including endometrial carcinoma, cervical cancer, testicular and ovarian cancer as well as prostate cancer. While activin A and B aid the progression of many tumours of the reproductive organs, activin C acts as a tumour suppressor. Activins are important in embryonic induction, morphogenesis of branched glandular organs, development of limbs and nervous system, craniofacial and dental development and morphogenesis of the Wolffian duct. CONCLUSIONS The field of activin biology has advanced considerably since its initial discovery as an FSH stimulating agent. Now, activin is well known as a growth factor and cytokine that regulates many aspects of reproductive biology, developmental biology and also inflammation and immunological mechanisms. Current research provides evidence for novel roles of activins in maintaining the structure and function of reproductive and other organ systems. The fact that activin A is elevated both locally as well as systemically in major disorders of the reproductive system makes it an important biomarker. Given the established role of activin A as a pro-inflammatory and pro-fibrotic agent, studies of its involvement in disorders of reproduction resulting from these processes should be examined. Follistatin, as a key regulator of the biological actions of activin, should be evaluated as a therapeutic agent in conditions where activin A overexpression is established as a contributing factor.
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Affiliation(s)
- R Wijayarathna
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia Centre for Reproductive Health, Hudson Institute of Medical Research, 27-31, Wright Street, Clayton, VIC 3168, Australia
| | - D M de Kretser
- Department of Anatomy and Developmental Biology, Monash University, Wellington Road, Clayton, VIC 3800, Australia Centre for Reproductive Health, Hudson Institute of Medical Research, 27-31, Wright Street, Clayton, VIC 3168, Australia
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Johnson KE, Makanji Y, Temple-Smith P, Kelly EK, Barton PA, Al-Musawi SL, Mueller TD, Walton KL, Harrison CA. Biological activity and in vivo half-life of pro-activin A in male rats. Mol Cell Endocrinol 2016; 422:84-92. [PMID: 26687063 DOI: 10.1016/j.mce.2015.12.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/07/2015] [Accepted: 12/07/2015] [Indexed: 01/01/2023]
Abstract
Mature TGF-β proteins are used in vivo to promote bone growth, combat obesity, reverse fibrosis and pulmonary arterial hypertension, and as potential rejuvenation factors. However, the serum half-life of this family of growth factors is short (∼5 min), limiting their therapeutic potential. Because TGF-β proteins are normally secreted from cells with their prodomains attached, we considered whether these molecules could extend the in vivo half-life and activity of their respective growth factors. Using activin A as a model ligand, we initially modified the cleavage site between the pro- and mature domains to ensure complete processing of the activin A precursor. Co-immunoprecipitation studies confirmed mature activin A is secreted from cells in a non-covalent complex with its prodomain, however, the affinity of this interaction is not sufficient to suppress activin A in vitro biological activity. The plasma clearance profiles of purified pro- and mature activin A were determined over a 4 h period in adult male rats. Both activin forms demonstrated a two-phase decay, with the half-life of pro-activin A (t1/2 fast = 12.5 min, slow = 31.0 min) being greater than that of mature activin A (t1/2 fast = 5.5 min, slow = 20.3 min). Both pro- and mature activin A induced significant increases in serum follicle stimulating hormone levels after 4 h, but no differences were observed in the relative in vivo bioactivities of the two activin isoforms. Increased serum half-life of activin A in the presence of its prodomain identifies a new means to increase the therapeutic effectiveness of TGF-β proteins.
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Affiliation(s)
- Katharine E Johnson
- Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | | | - Peter Temple-Smith
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC 3800, Australia
| | - Emily K Kelly
- Hudson Institute of Medical Research, Clayton, VIC 3168, Australia
| | - Peter A Barton
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
| | - Sara L Al-Musawi
- Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3800, Australia
| | - Thomas D Mueller
- Department of Plant Physiology and Biophysics, Julius-von-Sachs Institute of the University Wuerzburg, Julius-von Sachs Platz 2, Wuerzburg, Germany
| | - Kelly L Walton
- Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3800, Australia
| | - Craig A Harrison
- Hudson Institute of Medical Research, Clayton, VIC 3168, Australia; Department of Molecular and Translational Science, Monash University, Clayton, VIC 3800, Australia.
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31
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de Kretser DM, Bensley JG, Phillips DJ, Levvey BJ, Snell GI, Lin E, Hedger MP, O’Hehir RE. Substantial Increases Occur in Serum Activins and Follistatin during Lung Transplantation. PLoS One 2016; 11:e0140948. [PMID: 26820896 PMCID: PMC4731072 DOI: 10.1371/journal.pone.0140948] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/03/2015] [Indexed: 01/08/2023] Open
Abstract
Background Lung transplantation exposes the donated lung to a period of anoxia. Re-establishing the circulation after ischemia stimulates inflammation causing organ damage. Since our published data established that activin A is a key pro-inflammatory cytokine, we assessed the roles of activin A and B, and their binding protein, follistatin, in patients undergoing lung transplantation. Methods Sera from 46 patients participating in a published study of remote ischemia conditioning in lung transplantation were used. Serum activin A and B, follistatin and 11 other cytokines were measured in samples taken immediately after anaesthesia induction, after remote ischemia conditioning or sham treatment undertaken just prior to allograft reperfusion and during the subsequent 24 hours. Results Substantial increases in serum activin A, B and follistatin occurred after the baseline sample, taken before anaesthesia induction and peaked immediately after the remote ischemia conditioning/sham treatment. The levels remained elevated 15 minutes after lung transplantation declining thereafter reaching baseline 2 hours post-transplant. Activin B and follistatin concentrations were lower in patients receiving remote ischemia conditioning compared to sham treated patients but the magnitude of the decrease did not correlate with early transplant outcomes. Conclusions We propose that the increases in the serum activin A, B and follistatin result from a combination of factors; the acute phase response, the reperfusion response and the use of heparin-based anti-coagulants.
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Affiliation(s)
- David M. de Kretser
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
- Hudson Institute of Medical Research, Clayton, Victoria, Australia
- * E-mail:
| | - Jonathan G. Bensley
- Department of Anatomy and Developmental Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
| | | | - Bronwyn J. Levvey
- Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia
- Lung Transplant Service, Alfred Hospital, Melbourne, Victoria, Australia
| | - Greg I. Snell
- Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia
- Lung Transplant Service, Alfred Hospital, Melbourne, Victoria, Australia
- Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Enjarn Lin
- Department of Anaesthesia and Perioperative Medicine, Alfred Hospital, Melbourne, Victoria, Australia
| | - Mark P. Hedger
- Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Robyn E. O’Hehir
- Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia
- Lung Transplant Service, Alfred Hospital, Melbourne, Victoria, Australia
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Sharkey DJ, Schjenken JE, Mottershead DG, Robertson SA. Seminal fluid factors regulate activin A and follistatin synthesis in female cervical epithelial cells. Mol Cell Endocrinol 2015; 417:178-90. [PMID: 26415587 DOI: 10.1016/j.mce.2015.09.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/28/2015] [Accepted: 09/22/2015] [Indexed: 12/16/2022]
Abstract
Seminal fluid induces pro-inflammatory cytokines and elicits an inflammation-like response in the cervix. Here, Affymetrix microarray and qPCR was utilised to identify activin A (INHBA) and its inhibitor follistatin (FST) amongst the cytokines induced by seminal plasma in Ect1 ectocervical epithelial cells, and a similar response was confirmed in primary ectocervical epithelial cells. TGFB is abundant in seminal plasma and all three TGFB isoforms induced INHBA in Ect1 and primary cells, and neutralisation of TGFB in seminal plasma suppressed the INHBA response. Bacterial lipopolysaccharide in seminal plasma also elicited INHBA, but potently suppressed FST production. There was moderate reciprocal inhibition between FST and INHBA, and cross-attenuating effects were seen. These data identify TGFB and potentially LPS as factors mediating seminal plasma-induced INHBA synthesis in cervical cells. INHBA and FST induced by seminal fluid in cervical tissues may thus contribute to regulation of the post-coital response in women.
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Affiliation(s)
- David J Sharkey
- Robinson Research Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
| | - John E Schjenken
- Robinson Research Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
| | - David G Mottershead
- Robinson Research Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Sarah A Robertson
- Robinson Research Institute and School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia.
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Zhu J, Mishra RK, Schiltz GE, Makanji Y, Scheidt KA, Mazar AP, Woodruff TK. Virtual High-Throughput Screening To Identify Novel Activin Antagonists. J Med Chem 2015; 58:5637-48. [PMID: 26098096 DOI: 10.1021/acs.jmedchem.5b00753] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Activin belongs to the TGFβ superfamily, which is associated with several disease conditions, including cancer-related cachexia, preterm labor with delivery, and osteoporosis. Targeting activin and its related signaling pathways holds promise as a therapeutic approach to these diseases. A small-molecule ligand-binding groove was identified in the interface between the two activin βA subunits and was used for a virtual high-throughput in silico screening of the ZINC database to identify hits. Thirty-nine compounds without significant toxicity were tested in two well-established activin assays: FSHβ transcription and HepG2 cell apoptosis. This screening workflow resulted in two lead compounds: NUCC-474 and NUCC-555. These potential activin antagonists were then shown to inhibit activin A-mediated cell proliferation in ex vivo ovary cultures. In vivo testing showed that our most potent compound (NUCC-555) caused a dose-dependent decrease in FSH levels in ovariectomized mice. The Blitz competition binding assay confirmed target binding of NUCC-555 to the activin A:ActRII that disrupts the activin A:ActRII complex's binding with ALK4-ECD-Fc in a dose-dependent manner. The NUCC-555 also specifically binds to activin A compared with other TGFβ superfamily member myostatin (GDF8). These data demonstrate a new in silico-based strategy for identifying small-molecule activin antagonists. Our approach is the first to identify a first-in-class small-molecule antagonist of activin binding to ALK4, which opens a completely new approach to inhibiting the activity of TGFβ receptor superfamily members. in addition, the lead compound can serve as a starting point for lead optimization toward the goal of a compound that may be effective in activin-mediated diseases.
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Affiliation(s)
- Jie Zhu
- †Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, 303 East Superior Street, Lurie 10-250, Chicago, Illinois 60611, United States.,‡Center for Reproductive Science, Northwestern University, Evanston, Illinois 60208, United States
| | - Rama K Mishra
- §Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Gary E Schiltz
- §Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Yogeshwar Makanji
- †Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, 303 East Superior Street, Lurie 10-250, Chicago, Illinois 60611, United States
| | - Karl A Scheidt
- §Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States.,⊥Department of Chemistry, Northwestern University, Evanston, 60208, Illinois, United States.,∥Department of Pharmacology, Northwestern University, Chicago, Illinois 60611, United States
| | - Andrew P Mazar
- ∥Department of Pharmacology, Northwestern University, Chicago, Illinois 60611, United States.,□Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, Illinois 60208, United States
| | - Teresa K Woodruff
- †Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, 303 East Superior Street, Lurie 10-250, Chicago, Illinois 60611, United States.,‡Center for Reproductive Science, Northwestern University, Evanston, Illinois 60208, United States.,□Chemistry of Life Processes Institute, Northwestern University, 2170 Campus Drive, Evanston, Illinois 60208, United States
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Engineering TGF-β superfamily ligands for clinical applications. Trends Pharmacol Sci 2014; 35:648-57. [PMID: 25458539 DOI: 10.1016/j.tips.2014.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/14/2014] [Accepted: 10/14/2014] [Indexed: 12/11/2022]
Abstract
TGF-β superfamily ligands govern normal tissue development and homeostasis, and their dysfunction is a hallmark of many diseases. These ligands are also well defined both structurally and functionally. This review focuses on TGF-β superfamily ligand engineering for therapeutic purposes, in particular for regenerative medicine and musculoskeletal disorders. We describe the key discovery that structure-guided mutation of receptor-binding epitopes, especially swapping of these epitopes between ligands, results in new ligands with unique functional properties that can be harnessed clinically. Given the promising results with prototypical engineered TGF-β superfamily ligands, and the vast number of such molecules that remain to be produced and tested, this strategy is likely to hold great promise for the development of new biologics.
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Makanji Y, Zhu J, Mishra R, Holmquist C, Wong WPS, Schwartz NB, Mayo KE, Woodruff TK. Inhibin at 90: from discovery to clinical application, a historical review. Endocr Rev 2014; 35:747-94. [PMID: 25051334 PMCID: PMC4167436 DOI: 10.1210/er.2014-1003] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
When it was initially discovered in 1923, inhibin was characterized as a hypophysiotropic hormone that acts on pituitary cells to regulate pituitary hormone secretion. Ninety years later, what we know about inhibin stretches far beyond its well-established capacity to inhibit activin signaling and suppress pituitary FSH production. Inhibin is one of the major reproductive hormones involved in the regulation of folliculogenesis and steroidogenesis. Although the physiological role of inhibin as an activin antagonist in other organ systems is not as well defined as it is in the pituitary-gonadal axis, inhibin also modulates biological processes in other organs through paracrine, autocrine, and/or endocrine mechanisms. Inhibin and components of its signaling pathway are expressed in many organs. Diagnostically, inhibin is used for prenatal screening of Down syndrome as part of the quadruple test and as a biochemical marker in the assessment of ovarian reserve. In this review, we provide a comprehensive summary of our current understanding of the biological role of inhibin, its relationship with activin, its signaling mechanisms, and its potential value as a diagnostic marker for reproductive function and pregnancy-associated conditions.
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Affiliation(s)
- Yogeshwar Makanji
- Department of Obstetrics and Gynecology (Y.M., J.Z., C.H., W.P.S.W., T.K.W.), Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60610; Center for Molecular Innovation and Drug Discovery (R.M., C.H.), Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208; and Department of Molecular Biosciences (N.B.S., K.E.M., T.K.W.), Center for Reproductive Science, Northwestern University, Evanston, Illinois 60208
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Hedger MP, de Kretser DM. The activins and their binding protein, follistatin-Diagnostic and therapeutic targets in inflammatory disease and fibrosis. Cytokine Growth Factor Rev 2013; 24:285-95. [PMID: 23541927 DOI: 10.1016/j.cytogfr.2013.03.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 03/05/2013] [Indexed: 02/05/2023]
Abstract
The activins, as members of the transforming growth factor-β superfamily, are pleiotrophic regulators of cell development and function, including cells of the myeloid and lymphoid lineages. Clinical and animal studies have shown that activin levels increase in both acute and chronic inflammation, and are frequently indicators of disease severity. Moreover, inhibition of activin action can reduce inflammation, damage, fibrosis and morbidity/mortality in various disease models. Consequently, activin A and, more recently, activin B are emerging as important diagnostic tools and therapeutic targets in inflammatory and fibrotic diseases. Activin antagonists such as follistatin, an endogenous activin-binding protein, offer considerable promise as therapies in conditions as diverse as sepsis, liver fibrosis, acute lung injury, asthma, wound healing and ischaemia-reperfusion injury.
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Affiliation(s)
- M P Hedger
- Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
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Sepporta MV, Tumminello FM, Flandina C, Crescimanno M, Giammanco M, La Guardia M, di Majo D, Leto G. Follistatin as potential therapeutic target in prostate cancer. Target Oncol 2013; 8:215-23. [PMID: 23456439 DOI: 10.1007/s11523-013-0268-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 02/05/2013] [Indexed: 01/04/2023]
Abstract
Follistatin is a single-chain glycosylated protein whose primary function consists in binding and neutralizing some members of the transforming growth factor-β superfamily such as activin and bone morphogenic proteins. Emerging evidence indicates that this molecule may also play a role in the malignant progression of several human tumors including prostate cancer. In particular, recent findings suggest that, in this tumor, follistatin may also contribute to the formation of bone metastasis through multiple mechanisms, some of which are not related to its specific activin or bone morphogenic proteins' inhibitory activity. This review provides insight into the most recent advances in understanding the role of follistatin in the prostate cancer progression and discusses the clinical and therapeutic implications related to these findings.
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Affiliation(s)
- Maria Vittoria Sepporta
- Operative Unit of Physiology and Pharmacology, University of Palermo, via Augusto Elia, 3, 90127, Palermo, Italy
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Activin, neutrophils, and inflammation: just coincidence? Semin Immunopathol 2013; 35:481-99. [PMID: 23385857 PMCID: PMC7101603 DOI: 10.1007/s00281-013-0365-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 01/17/2013] [Indexed: 01/18/2023]
Abstract
During the 26 years that have elapsed since its discovery, activin-A, a member of the transforming growth factor β super-family originally discovered from its capacity to stimulate follicle-stimulating hormone production by cultured pituitary gonadotropes, has been established as a key regulator of various fundamental biological processes, such as development, homeostasis, inflammation, and tissue remodeling. Deregulated expression of activin-A has been observed in several human diseases characterized by an immuno-inflammatory and/or tissue remodeling component in their pathophysiology. Various cell types have been recognized as sources of activin-A, and plentiful, occasionally contradicting, functions have been described mainly by in vitro studies. Not surprisingly, both harmful and protective roles have been postulated for activin-A in the context of several disorders. Recent findings have further expanded the functional repertoire of this molecule demonstrating that its ectopic overexpression in mouse airways can cause pathology that simulates faithfully human acute respiratory distress syndrome, a disorder characterized by strong involvement of neutrophils. This finding when considered together with the recent discovery that neutrophils constitute an important source of activin-A in vivo and earlier observations of upregulated activin-A expression in diseases characterized by strong activation of neutrophils may collectively imply a more intimate link between activin-A expression and neutrophil reactivity. In this review, we provide an outline of the functional repertoire of activin-A and suggest that this growth factor functions as a guardian of homeostasis, a modulator of immunity and an orchestrator of tissue repair activities. In this context, a relationship between activin-A and neutrophils may be anything but coincidental.
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de Kretser DM, O'Hehir RE, Hardy CL, Hedger MP. The roles of activin A and its binding protein, follistatin, in inflammation and tissue repair. Mol Cell Endocrinol 2012; 359:101-6. [PMID: 22037168 DOI: 10.1016/j.mce.2011.10.009] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 10/06/2011] [Accepted: 10/13/2011] [Indexed: 01/15/2023]
Abstract
Activin A, a member of the transforming growth factor-β superfamily of cytokines, is a critical controller of inflammation, immunity and fibrosis. It is rapidly released into the blood following a lipopolysaccharide challenge in experimental animals, through activation of the Toll-like receptor 4 signalling pathway. Blocking activin action by pre-treatment with its binding protein, follistatin, modifies the inflammatory cytokine cascade, and reduces the severity of the subsequent inflammatory response and mortality. Likewise, high serum levels of activin A are predictive of death in patients with septicaemia. However, activin A has complex immunomodulatory actions. It is produced by inflammatory macrophages, but can regulate either pro- or anti-inflammatory responses in these cells, depending on their prior activation status. Activin A is also produced by Th2 cells, and stimulates antibody production by B cells and the development of regulatory T cells. Production of activin A during inflammatory responses stimulates fibrosis and tissue remodelling, and follistatin inhibits these actions of activin A. The modulation of activin by follistatin may represent an important therapeutic target for the modulation and amelioration of inflammatory and fibrotic disorders.
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Affiliation(s)
- David M de Kretser
- Monash Institute of Medical Research and the Department of Immunology and Pathology, Monash University, Clayton Victoria 3800, Australia.
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Zhang F, Beaudet JM, Luedeke DM, Walker RG, Thompson TB, Linhardt RJ. Analysis of the interaction between heparin and follistatin and heparin and follistatin-ligand complexes using surface plasmon resonance. Biochemistry 2012; 51:6797-803. [PMID: 22809401 DOI: 10.1021/bi300804g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heparin and related heparan sulfate interact with a number of cytokines and growth factors, thereby playing an essential role in many physiological and pathophysiological processes by involving both signal transduction and the regulation of the tissue distribution of cytokines/growth factors. Follistatin (FS) is an autocrine protein with a heparin-binding motif that serves to regulate the cell proliferative activity of the paracrine hormone, and member of the TGF-β family, activin A (ActA). Follistatin is currently under investigation as an antagonist of another TGF-β family member, myostatin (Mstn), for the promotion of muscle growth in diseases associated with muscle atrophy. In this study, we employ surface plasmon resonance (SPR) spectroscopy to dissect the binding interactions between the heparin polysaccharide and both free follistatin (FS288) and its complexes (FS288-ActA and FS288-Mstn). FS288 complexes show much higher heparin binding affinity than FS288 alone. SPR solution competition studies using heparin oligosaccharides showed that the binding of FS288 and its complex to heparin is dependent on chain length. Full chain heparin or large oligosaccharides, having 18-20 sugar residues, show the highest binding activity for FS288 and the FS288-ActA complex, whereas smaller heparin molecules could interact with the FS288-Mstn complex. These interactions were also analyzed in normal physiological buffers and at different salt concentrations and pH values. Unbound follistatin was much more sensitive to all salt concentrations of >150 mM. The binding of heparin to the FS288-ActA complex was disrupted at 500 mM salt, whereas it was actually strengthened for the FS288-Mstn complex. At acidic pH values, binding of heparin to FS288 and the FS288-ActA complex was enhanced. While slightly acidic pH values (pH 6.2 and 5.2) enhanced the binding of the FS288-Mstn complex to heparin, at pH 4 heparin binding was inhibited. Overall, these studies demonstrate that binding of a specific ligand to FS288 differentially regulates its affinity and behavior for heparin molecules.
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Affiliation(s)
- Fuming Zhang
- Department of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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Cash JN, Angerman EB, Keutmann HT, Thompson TB. Characterization of follistatin-type domains and their contribution to myostatin and activin A antagonism. Mol Endocrinol 2012; 26:1167-78. [PMID: 22593183 DOI: 10.1210/me.2012-1061] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Follistatin (FST)-type proteins are important antagonists of some members of the large TGF-β family of cytokines. These include myostatin, an important negative regulator of muscle growth, and the closely related activin A, which is involved in many physiological functions, including maintenance of a normal reproductive axis. FST-type proteins, including FST and FST-like 3 (FSTL3), differentially inhibit various TGF-β family ligands by binding each ligand with two FST-type molecules. In this study, we sought to examine features that are important for ligand antagonism by FST-type proteins. Previous work has shown that a modified construct consisting of the FST N-terminal domain (ND) followed by two repeating follistatin domains (FSD), herein called FST ND-FSD1-FSD1, exhibits strong specificity for myostatin over activin A. Using cell-based assays, we show that FST ND-FSD1-FSD1 is unique in its specificity for myostatin as compared with similar constructs containing domains from FSTL3 and that the ND is critical to its activity. Furthermore, we demonstrate that FSD3 of FST provides affinity to ligand inhibition and confers resistance to perturbations in the ND and FSD2, likely through the interaction of FSD3 of one FST molecule with the ND of the other FST molecule. Additionally, our data suggest that this contact provides cooperativity to ligand antagonism. Cross-linking studies show that this interaction also potentiates formation of 1:2 ligand-FST complexes, whereas lack of FSD3 allows formation of 1:1 complexes. Altogether, these studies support that domain differences generate FST-type molecules that are each uniquely suited ligand antagonists.
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Affiliation(s)
- Jennifer N Cash
- Department of Molecular Genetics, University of Cincinnati Medical Sciences Building, 231 Albert Sabin Way, Cincinnati, Ohio 45267, USA
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Kattamuri C, Luedeke DM, Thompson TB. Expression and purification of recombinant protein related to DAN and cerberus (PRDC). Protein Expr Purif 2012; 82:389-95. [PMID: 22381466 DOI: 10.1016/j.pep.2012.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/10/2012] [Accepted: 02/11/2012] [Indexed: 10/28/2022]
Abstract
Bone morphogenetic proteins (BMPs) are secreted protein ligands that control numerous biological processes, such as cell differentiation and cell proliferation. Ligands are regulated by a large number of structurally diverse extracellular antagonists. PRDC or protein related to DAN and cerberus is a BMP antagonist of the DAN family, which is defined by a conserved pattern of cysteine residues that form a ring structure. Here we present the expression and purification of recombinant mouse PRDC (mPRDC) from bacterial (Escherichia coli) inclusion bodies through oxidative refolding. Functional mPRDC was isolated from a nonfunctional component through reverse phase chromatography and shown to inhibit BMP2 and BMP4 in a cell-based luciferase reporter assay. Recombinant mPRDC also bound directly to BMP2, BMP4 and BMP7, but not activin A. Furthermore, circular dichroism indicated that mPRDC is folded and contains a higher than anticipated helical content for a DAN family member protein.
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Affiliation(s)
- Chandramohan Kattamuri
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati Medical Sciences Building, Cincinnati, OH 45267, United States
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Zhu J, Lin SJ, Zou C, Makanji Y, Jardetzky TS, Woodruff TK. Inhibin α-subunit N terminus interacts with activin type IB receptor to disrupt activin signaling. J Biol Chem 2012; 287:8060-70. [PMID: 22267736 DOI: 10.1074/jbc.m111.293381] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inhibin is a heterodimeric peptide hormone produced in the ovary that antagonizes activin signaling and FSH synthesis in the pituitary. The inhibin β-subunit interacts with the activin type II receptor (ActRII) to functionally antagonize activin. The inhibin α-subunit mature domain (N terminus) arose relatively early during the evolution of the hormone, and inhibin function is decreased by an antibody directed against the α-subunit N-terminal extension region or by deletion of the N-terminal region. We hypothesized that the α-subunit N-terminal extension region interacts with the activin type I receptor (ALK4) to antagonize activin signaling in the pituitary. Human or chicken free α-subunit inhibited activin signaling in a pituitary gonadotrope-derived cell line (LβT2) in a dose-dependent manner, whereas an N-terminal extension deletion mutant did not. An α-subunit N-terminal peptide, but not a control peptide, was able to inhibit activin A signaling and decrease activin-stimulated FSH synthesis. Biotinylated inhibin A, but not activin A, bound ALK4. Soluble ALK4-ECD bioneutralized human free α-subunit in LβT2 cells, but did not affect activin A function. Competitive binding ELISAs with N-terminal mutants and an N-terminal region peptide confirmed that this region is critical for direct interaction of the α-subunit with ALK4. These data expand our understanding of how endocrine inhibin achieves potent antagonism of local, constitutive activin action in the pituitary, through a combined mechanism of competitive binding of both ActRII and ALK4 by each subunit of the inhibin heterodimer, in conjunction with the co-receptor betaglycan, to block activin receptor-ligand binding, complex assembly, and downstream signaling.
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Affiliation(s)
- Jie Zhu
- Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Craythorn RG, Winnall WR, Lederman F, Gold EJ, O'Connor AE, de Kretser DM, Hedger MP, Rogers PAW, Girling JE. Progesterone stimulates expression of follistatin splice variants Fst288 and Fst315 in the mouse uterus. Reprod Biomed Online 2011; 24:364-74. [PMID: 22285243 DOI: 10.1016/j.rbmo.2011.12.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 12/07/2011] [Accepted: 12/13/2011] [Indexed: 12/20/2022]
Abstract
Follistatin, an inhibitor of activin A, has key regulatory roles in the female reproductive tract. Follistatin has two splice variants: FST288, largely associated with cell surfaces, and FST315, the predominant circulating form. The mechanism regulating uterine expression of these variants is unknown. Quantitative RT-PCR was used to measure expression of follistatin splice variants (Fst288, Fst315), the activin bA subunit (Inhba) and the inhibin a subunit (Inha) in uterine tissues during early pregnancy (days 1–4, preimplantation) and in response to exogenous 17b-oestradiol (single s.c. injection) and progesterone (three daily s.c. injections) in ovariectomized mice. Uterine Fst288, Fst315 and Inhba expression increased during early pregnancy, with greater increases in Fst315 relative to Fst288 suggesting differential regulation of these variants. Fst288, Fst315, Inhba and Inha all increased in response to progesterone treatment. Fst288, but not Fst315, mRNA decreased in response to 17b-oestradiol treatment, whereas Inhba increased. A comparison of the absolute concentrations of uterine follistatin mRNA using crossing thresholds indicated that both variants were more highly expressed in early pregnancy in contrast to the hormone treatment models. It is concluded that progesterone regulates uterine expression of both follistatin variants, as well as activin A, during early pregnancy in the mouse uterus
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Affiliation(s)
- R G Craythorn
- Centre for Women's Health Research, Monash University Department of Obstetrics and Gynaecology, Monash Institute of Medical Research, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria 3168, Australia
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Cash JN, Angerman EB, Kattamuri C, Nolan K, Zhao H, Sidis Y, Keutmann HT, Thompson TB. Structure of myostatin·follistatin-like 3: N-terminal domains of follistatin-type molecules exhibit alternate modes of binding. J Biol Chem 2011; 287:1043-53. [PMID: 22052913 DOI: 10.1074/jbc.m111.270801] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
TGF-β family ligands are involved in a variety of critical physiological processes. For instance, the TGF-β ligand myostatin is a staunch negative regulator of muscle growth and a therapeutic target for muscle-wasting disorders. Therefore, it is important to understand the molecular mechanisms of TGF-β family regulation. One form of regulation is through inhibition by extracellular antagonists such as the follistatin (Fst)-type proteins. Myostatin is tightly controlled by Fst-like 3 (Fstl3), which is the only Fst-type molecule that has been identified in the serum bound to myostatin. Here, we present the crystal structure of myostatin in complex with Fstl3. The structure reveals that the N-terminal domain (ND) of Fstl3 interacts uniquely with myostatin as compared with activin A, because it utilizes different surfaces on the ligand. This results in conformational differences in the ND of Fstl3 that alter its position in the type I receptor-binding site of the ligand. We also show that single point mutations in the ND of Fstl3 are detrimental to ligand binding, whereas corresponding mutations in Fst have little effect. Overall, we have shown that the NDs of Fst-type molecules exhibit distinctive modes of ligand binding, which may affect overall affinity of ligand·Fst-type protein complexes.
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Affiliation(s)
- Jennifer N Cash
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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Urshansky N, Mausner-Fainberg K, Auriel E, Regev K, Karni A. Low and dysregulated production of follistatin in immune cells of relapsing-remitting multiple sclerosis patients. J Neuroimmunol 2011; 238:96-103. [PMID: 21880375 DOI: 10.1016/j.jneuroim.2011.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/14/2011] [Accepted: 08/03/2011] [Indexed: 12/29/2022]
Abstract
One of the mechanisms known to play a key role in neuronal and oligodendroglial fate specification of neural stem cells (NSCs) is restriction of bone morphogenic proteins (BMP) signaling by BMP antagonists. Here, we demonstrate that follistatin mRNA and protein secreted levels in peripheral blood mononuclear cells (PBMCs) of relapsing-remitting multiple sclerosis (RR-MS) patients are significantly reduced compared to healthy controls (HC). We also observed a different profile of regulation mechanisms. Follistatin was similarly expressed and secreted by T lymphocytes and monocytes among the PBMCs of HC, and follistatin upregulation of HC was subjected to stimulation with both LPS and TNF-α. Among PBMCs of RR-MS patients, however, follistatin was found to be downregulated in their monocytes and unresponsive to stimulation with either LPS or TNF-α. Our results may shed some light on the mechanisms involved in remyelination failure in MS, which may be related to the inability of RR-MS patients' immune cells to provide a sufficient pro-neurogenic and oligodendrogenic niche, by expressing and secreting follistatin, in addition to the previously described noggin reduced expression. Our results indicate that the low expression of follistatin in immune cells of patients with RR-MS is a result of the altered immunoregulation of monocytes in these patients.
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Affiliation(s)
- Nataly Urshansky
- Neuroimmunology Laboratory, Department of Neurology, Tel Aviv Sourasky Medical Center, Tel Aviv University, Tel Aviv, Israel.
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Hedger MP, Winnall WR, Phillips DJ, de Kretser DM. The regulation and functions of activin and follistatin in inflammation and immunity. VITAMINS AND HORMONES 2011; 85:255-97. [PMID: 21353885 DOI: 10.1016/b978-0-12-385961-7.00013-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The activins are members of the transforming growth factor β superfamily with broad and complex effects on cell growth and differentiation. Activin A has long been known to be a critical regulator of inflammation and immunity, and similar roles are now emerging for activin B, with which it shares 65% sequence homology. These molecules and their binding protein, follistatin, are widely expressed, and their production is increased in many acute and chronic inflammatory conditions. Synthesis and release of the activins are stimulated by inflammatory cytokines, Toll-like receptor ligands, and oxidative stress. The activins interact with heterodimeric serine/threonine kinase receptor complexes to activate SMAD transcription factors and the MAP kinase signaling pathways, which mediate inflammation, stress, and immunity. Follistatin binds to the activins with high affinity, thereby obstructing the activin receptor binding site, and targets them to cell surface proteoglycans and lysosomal degradation. Studies on transgenic mice and those with gene knockouts, together with blocking studies using exogenous follistatin, have established that activin A plays critical roles in the onset of cachexia, acute and chronic inflammatory responses such as septicemia, colitis and asthma, and fibrosis. However, activin A also directs the development of monocyte/macrophages, myeloid dendritic cells, and T cell subsets to promote type 2 and regulatory immune responses. The ability of both endogenous and exogenous follistatin to block the proinflammatory and profibrotic actions of activin A has led to interest in this binding protein as a potential therapeutic for limiting the severity of disease and to improve subsequent damage associated with inflammation and fibrosis. However, the ability of activin A to sculpt the subsequent immune response as well means that the full range of effects that might arise from blocking activin bioactivity will need to be considered in any therapeutic applications.
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Affiliation(s)
- Mark P Hedger
- Monash Institute of Medical Research, Monash University, Monash Medical Centre, Clayton, Victoria, Australia
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Pattern of activin A and follistatin release in a sheep model of cardiopulmonary bypass. Cytokine 2011; 54:154-60. [DOI: 10.1016/j.cyto.2011.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 12/11/2010] [Accepted: 01/02/2011] [Indexed: 11/22/2022]
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Bone morphogenetic protein and growth differentiation factor cytokine families and their protein antagonists. Biochem J 2010; 429:1-12. [PMID: 20545624 DOI: 10.1042/bj20100305] [Citation(s) in RCA: 170] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The BMPs (bone morphogenetic proteins) and the GDFs (growth and differentiation factors) together form a single family of cystine-knot cytokines, sharing the characteristic fold of the TGFbeta (transforming growth factor-beta) superfamily. Besides the ability to induce bone formation, which gave the BMPs their name, the BMP/GDFs display morphogenetic activities in the development of a wide range of tissues. BMP/GDF homo- and hetero-dimers interact with combinations of type I and type II receptor dimers to produce multiple possible signalling complexes, leading to the activation of one of two competing sets of SMAD transcription factors. BMP/GDFs have highly specific and localized functions. These are regulated in a number of ways, including the developmental restriction of BMP/GDF expression and through the secretion of several specific BMP antagonist proteins that bind with high affinity to the cytokines. Curiously, a number of these antagonists are also members of the TGF-beta superfamily. Finally a number of both the BMP/GDFs and their antagonists interact with the heparan sulphate side chains of cell-surface and extracellular-matrix proteoglycans.
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The structure of myostatin:follistatin 288: insights into receptor utilization and heparin binding. EMBO J 2009; 28:2662-76. [PMID: 19644449 PMCID: PMC2738701 DOI: 10.1038/emboj.2009.205] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 06/22/2009] [Indexed: 01/07/2023] Open
Abstract
Myostatin is a member of the transforming growth factor-beta (TGF-beta) family and a strong negative regulator of muscle growth. Here, we present the crystal structure of myostatin in complex with the antagonist follistatin 288 (Fst288). We find that the prehelix region of myostatin very closely resembles that of TGF-beta class members and that this region alone can be swapped into activin A to confer signalling through the non-canonical type I receptor Alk5. Furthermore, the N-terminal domain of Fst288 undergoes conformational rearrangements to bind myostatin and likely acts as a site of specificity for the antagonist. In addition, a unique continuous electropositive surface is created when myostatin binds Fst288, which significantly increases the affinity for heparin. This translates into stronger interactions with the cell surface and enhanced myostatin degradation in the presence of either Fst288 or Fst315. Overall, we have identified several characteristics unique to myostatin that will be paramount to the rational design of myostatin inhibitors that could be used in the treatment of muscle-wasting disorders.
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