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Sartori R, Hagg A, Zampieri S, Armani A, Winbanks CE, Viana LR, Haidar M, Watt KI, Qian H, Pezzini C, Zanganeh P, Turner BJ, Larsson A, Zanchettin G, Pierobon ES, Moletta L, Valmasoni M, Ponzoni A, Attar S, Da Dalt G, Sperti C, Kustermann M, Thomson RE, Larsson L, Loveland KL, Costelli P, Megighian A, Merigliano S, Penna F, Gregorevic P, Sandri M. Perturbed BMP signaling and denervation promote muscle wasting in cancer cachexia. Sci Transl Med 2021; 13:eaay9592. [PMID: 34349036 DOI: 10.1126/scitranslmed.aay9592] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 03/18/2021] [Indexed: 02/05/2023]
Abstract
Most patients with advanced solid cancers exhibit features of cachexia, a debilitating syndrome characterized by progressive loss of skeletal muscle mass and strength. Because the underlying mechanisms of this multifactorial syndrome are incompletely defined, effective therapeutics have yet to be developed. Here, we show that diminished bone morphogenetic protein (BMP) signaling is observed early in the onset of skeletal muscle wasting associated with cancer cachexia in mouse models and in patients with cancer. Cancer-mediated factors including Activin A and IL-6 trigger the expression of the BMP inhibitor Noggin in muscle, which blocks the actions of BMPs on muscle fibers and motor nerves, subsequently causing disruption of the neuromuscular junction (NMJ), denervation, and muscle wasting. Increasing BMP signaling in the muscles of tumor-bearing mice by gene delivery or pharmacological means can prevent muscle wasting and preserve measures of NMJ function. The data identify perturbed BMP signaling and denervation of muscle fibers as important pathogenic mechanisms of muscle wasting associated with tumor growth. Collectively, these findings present interventions that promote BMP-mediated signaling as an attractive strategy to counteract the loss of functional musculature in patients with cancer.
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Affiliation(s)
- Roberta Sartori
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Adam Hagg
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | - Sandra Zampieri
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
- Myology Center, University of Padova, 35122 Padua, Italy
| | - Andrea Armani
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | | | - Laís R Viana
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Structural and Functional Biology, Biology Institute, University of Campinas, Campinas, São Paulo 13083-97, Brazil
| | - Mouna Haidar
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Kevin I Watt
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Hongwei Qian
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Camilla Pezzini
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Pardis Zanganeh
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Bradley J Turner
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Anna Larsson
- Theme Cancer, Karolinska University Hospital, Solna 171 76, Sweden
| | - Gianpietro Zanchettin
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Elisa S Pierobon
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Lucia Moletta
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Michele Valmasoni
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Alberto Ponzoni
- Department of Radiology, Padova General Hospital, 35121 Padova, Italy
| | - Shady Attar
- Department of Medicine, University Hospital of Padova, 35121 Padova, Italy
| | - Gianfranco Da Dalt
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Cosimo Sperti
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Monika Kustermann
- Center for Anatomy and Cell Biology, Medical University of Vienna, 1090 Vienna, Austria
| | - Rachel E Thomson
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
- Department of Biobehavioral Health, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kate L Loveland
- Centre for Reproductive Health. Hudson Institute of Medical Research, Clayton, VIC 3168, Australia
- Department of Molecular and Translational Sciences, and Anatomy and Developmental Biology, Monash University, VIC 3800, Australia
| | - Paola Costelli
- Department of Clinical and Biological Sciences, University of Turin, 10125 Turin, Italy
| | - Aram Megighian
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Stefano Merigliano
- Department of Surgery, Oncology and Gastroenterology, 3rd Surgical Clinic, University of Padova, 35128 Padua, Italy
| | - Fabio Penna
- Department of Clinical and Biological Sciences, University of Turin, 10125 Turin, Italy
| | - Paul Gregorevic
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia.
- Centre for Muscle Research, Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC 3010, Australia
- Department of Biochemistry and Molecular Biology, Monash University, VIC 3800, Australia
- Department of Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Marco Sandri
- Veneto Institute of Molecular Medicine, 35129 Padova, Italy.
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
- Myology Center, University of Padova, 35122 Padua, Italy
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
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Horlock D, Kaye DM, Winbanks CE, Gao XM, Kiriazis H, Donner DG, Gregorevic P, McMullen JR, Bernardo BC. Old Drug, New Trick: Tilorone, a Broad-Spectrum Antiviral Drug as a Potential Anti-Fibrotic Therapeutic for the Diseased Heart. Pharmaceuticals (Basel) 2021; 14:ph14030263. [PMID: 33804032 PMCID: PMC7998193 DOI: 10.3390/ph14030263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 11/16/2022] Open
Abstract
Cardiac fibrosis is associated with most forms of cardiovascular disease. No reliable therapies targeting cardiac fibrosis are available, thus identifying novel drugs that can resolve or prevent fibrosis is needed. Tilorone, an antiviral agent, can prevent fibrosis in a mouse model of lung disease. We investigated the anti-fibrotic effects of tilorone in human cardiac fibroblasts in vitro by performing a radioisotopic assay for [3H]-proline incorporation as a proxy for collagen synthesis. Exploratory studies in human cardiac fibroblasts treated with tilorone (10 µM) showed a significant reduction in transforming growth factor-β induced collagen synthesis compared to untreated fibroblasts. To determine if this finding could be recapitulated in vivo, mice with established pathological remodelling due to four weeks of transverse aortic constriction (TAC) were administered tilorone (50 mg/kg, i.p) or saline every third day for eight weeks. Treatment with tilorone was associated with attenuation of fibrosis (assessed by Masson's trichrome stain), a favourable cardiac gene expression profile and no further deterioration of cardiac systolic function determined by echocardiography compared to saline treated TAC mice. These data demonstrate that tilorone has anti-fibrotic actions in human cardiac fibroblasts and the adult mouse heart, and represents a potential novel therapy to treat fibrosis associated with heart failure.
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Affiliation(s)
- Duncan Horlock
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
| | - David M. Kaye
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Department of Cardiology, Alfred Hospital, Melbourne, VIC 3004, Australia
- Department of Medicine, Monash University, Clayton, VIC 3800, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - Catherine E. Winbanks
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
| | - Xiao-Ming Gao
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Disease in Central Asia, Clinical Medical Research Institute of Xinjiang Medical University, Urumqi 830054, China
| | - Helen Kiriazis
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - Daniel G. Donner
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
| | - Paul Gregorevic
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Centre for Muscle Research, Department of Physiology, University of Melbourne, Parkville, VIC 3010, Australia
| | - Julie R. McMullen
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Department of Medicine, Monash University, Clayton, VIC 3800, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Parkville, VIC 3010, Australia
- Department of Diabetes, Central Clinical School, Monash University, Clayton, VIC 3800, Australia
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC 3086, Australia
| | - Bianca C. Bernardo
- Baker Heart and Diabetes Institute, Melbourne, VIC 3004, Australia; (D.H.); (D.M.K.); (C.E.W.); (X.-M.G.); (H.K.); (D.G.D.); (P.G.); (J.R.M.)
- Department of Diabetes, Central Clinical School, Monash University, Clayton, VIC 3800, Australia
- Department of Paediatrics, University of Melbourne, VIC 3010, Australia
- Correspondence: ; Tel.: +61-(0)3-8532-1167; Fax: +61-(0)3-8532-1100
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Winbanks CE, Murphy KT, Bernardo BC, Qian H, Liu Y, Sepulveda PV, Beyer C, Hagg A, Thomson RE, Chen JL, Walton KL, Loveland KL, McMullen JR, Rodgers BD, Harrison CA, Lynch GS, Gregorevic P. Smad7 gene delivery prevents muscle wasting associated with cancer cachexia in mice. Sci Transl Med 2017; 8:348ra98. [PMID: 27440729 DOI: 10.1126/scitranslmed.aac4976] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/22/2016] [Indexed: 12/12/2022]
Abstract
Patients with advanced cancer often succumb to complications arising from striated muscle wasting associated with cachexia. Excessive activation of the type IIB activin receptor (ActRIIB) is considered an important mechanism underlying this wasting, where circulating procachectic factors bind ActRIIB and ultimately lead to the phosphorylation of SMAD2/3. Therapeutics that antagonize the binding of ActRIIB ligands are in clinical development, but concerns exist about achieving efficacy without off-target effects. To protect striated muscle from harmful ActRIIB signaling, and to reduce the risk of off-target effects, we developed an intervention using recombinant adeno-associated viral vectors (rAAV vectors) that increase expression of Smad7 in skeletal and cardiac muscles. SMAD7 acts as an intracellular negative regulator that prevents SMAD2/3 activation and promotes degradation of ActRIIB complexes. In mouse models of cachexia, rAAV:Smad7 prevented wasting of skeletal muscles and the heart independent of tumor burden and serum levels of procachectic ligands. Mechanistically, rAAV:Smad7 administration abolished SMAD2/3 signaling downstream of ActRIIB and inhibited expression of the atrophy-related ubiquitin ligases MuRF1 and MAFbx. These findings identify muscle-directed Smad7 gene delivery as a potential approach for preventing muscle wasting under conditions where excessive ActRIIB signaling occurs, such as cancer cachexia.
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Affiliation(s)
| | - Kate T Murphy
- Department of Physiology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Bianca C Bernardo
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Hongwei Qian
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Yingying Liu
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | | | - Claudia Beyer
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Adam Hagg
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Rachel E Thomson
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - Justin L Chen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia. Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia
| | - Kelly L Walton
- Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia
| | - Kate L Loveland
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Julie R McMullen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia. Department of Medicine, Monash University, Clayton, Victoria 3800, Australia. Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Buel D Rodgers
- Department of Animal Sciences, Washington State University, Pullman, WA 99164, USA
| | - Craig A Harrison
- Hudson Institute of Medical Research, Clayton, Victoria 3168, Australia. Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia. Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Gordon S Lynch
- Department of Physiology, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Paul Gregorevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia. Department of Physiology, The University of Melbourne, Melbourne, Victoria 3010, Australia. Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia. Department of Neurology, The University of Washington School of Medicine, Seattle, WA 98195, USA.
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Winbanks CE, Ooi JY, Nguyen SS, McMullen JR, Bernardo BC. MicroRNAs differentially regulated in cardiac and skeletal muscle in health and disease: potential drug targets? Clin Exp Pharmacol Physiol 2015; 41:727-37. [PMID: 25115402 DOI: 10.1111/1440-1681.12281] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/10/2014] [Accepted: 06/20/2014] [Indexed: 11/29/2022]
Abstract
The identification of non-coding RNA species, previously thought of as 'junk' DNA, adds a new dimension of complexity to the regulation of DNA, RNA and protein. MicroRNAs are short non-coding RNA species that control gene expression, are dysregulated in settings of cardiac and skeletal muscle disease and have emerged as promising therapeutic targets. MicroRNAs specifically enriched in cardiac and skeletal muscle are called myomiRs and play an important role in cardiac pathology and skeletal muscle biology. Moreover, microRNA profiles are altered in response to exercise and disease; thus, their potential as therapeutic drug targets is being widely explored. In the cardiovascular field, therapeutic inhibition of microRNAs has been shown to be effective in improving cardiac outcome in preclinical cardiac disease models. MicroRNAs that promote skeletal muscle regeneration are attractive therapeutic targets in muscle wasting conditions where regenerative capacity is compromised.
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Affiliation(s)
- Catherine E Winbanks
- Baker IDI Heart and Diabetes Institute, Monash University, Melbourne, Vic., Australia
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Bernardo BC, Nguyen SS, Winbanks CE, Gao XM, Boey EJH, Tham YK, Kiriazis H, Ooi JYY, Porrello ER, Igoor S, Thomas CJ, Gregorevic P, Lin RCY, Du XJ, McMullen JR. Therapeutic silencing of miR-652 restores heart function and attenuates adverse remodeling in a setting of established pathological hypertrophy. FASEB J 2014; 28:5097-110. [PMID: 25145628 DOI: 10.1096/fj.14-253856] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Expression of microRNA-652 (miR-652) increases in the diseased heart, decreases in a setting of cardioprotection, and is inversely correlated with heart function. The aim of this study was to assess the therapeutic potential of inhibiting miR-652 in a mouse model with established pathological hypertrophy and cardiac dysfunction due to pressure overload. Mice were subjected to a sham operation or transverse aortic constriction (TAC) for 4 wk to induce hypertrophy and cardiac dysfunction, followed by administration of a locked nucleic acid (LNA)-antimiR-652 (miR-652 inhibitor) or LNA control. Cardiac function was assessed before and 8 wk post-treatment. Expression of miR-652 increased in hearts subjected to TAC compared to sham surgery (2.9-fold), and this was suppressed by ∼95% in LNA-antimiR-652-treated TAC mice. Inhibition of miR-652 improved cardiac function in TAC mice (fractional shortening:29±1% at 4 wk post-TAC compared to 35±1% post-treatment) and attenuated cardiac hypertrophy. Improvement in heart function was associated with reduced cardiac fibrosis, less apoptosis and B-type natriuretic peptide gene expression, and preserved angiogenesis. Mechanistically, we identified Jagged1 (a Notch1 ligand) as a novel direct target of miR-652. In summary, these studies provide the first evidence that silencing of miR-652 protects the heart against pathological remodeling and improves heart function.
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Affiliation(s)
- Bianca C Bernardo
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia;
| | - Sally S Nguyen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia; Department of Human Biosciences, La Trobe University, Bundoora, Victoria, Australia
| | | | - Xiao-Ming Gao
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Esther J H Boey
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Yow Keat Tham
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Helen Kiriazis
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Jenny Y Y Ooi
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Enzo R Porrello
- School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, Australia; and
| | - Sindhu Igoor
- School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, Australia; and
| | - Colleen J Thomas
- Department of Human Biosciences, La Trobe University, Bundoora, Victoria, Australia
| | - Paul Gregorevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Ruby C Y Lin
- Ramaciotti Centre for Genomics and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Julie R McMullen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia;
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Bernardo BC, Nguyen SS, Winbanks CE, Gao XM, Boey EJ, Tham YK, Kiriazis H, Thomas CJ, Lin RC, Du XJ, McMullen JR. Abstract 50: Therapeutic Silencing of miRNA-652 Restores Cardiac Function and Attenuates Pathological Remodeling in a Mouse Model of Pressure Overload. Circ Res 2014. [DOI: 10.1161/res.115.suppl_1.50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Targeting microRNAs differentially regulated in settings of stress and protection could represent a new approach for the treatment of heart failure. miR-652 expression increased in hearts of a cardiac stress mouse model and was downregulated in a model of cardiac protection.
Aim:
To assess the therapeutic potential of silencing miR-652 in a mouse model with established pathological hypertrophy and cardiac dysfunction due to pressure overload.
Methods:
Mice were subjected to a sham operation (n=10) or transverse aortic constriction (TAC, n=14) for 4 weeks to induce hypertrophy and cardiac dysfunction. Mice were subcutaneously administered a locked nucleic acid (LNA)-antimiR-652 or LNA-control. Cardiac function was assessed by echocardiography before and 8 weeks post treatment, followed by molecular and histological analyses.
Results:
Expression of miR-652 increased in hearts subjected to pressure overload compared to sham operated mice (2.9 fold, n=3-5, P<0.05), but was silenced in hearts of mice administered LNA-antimiR-652 (95% decrease, n=3-7, P<0.05). In mice subjected to pressure overload, inhibition of miR-652 improved cardiac function (29±1% at 4 weeks post TAC compared to 35±1% post treatment, n=7, P<0.001) and attenuated cardiac hypertrophy. Functional and morphologic improvements in hearts of treated mice were associated with reduced cardiac fibrosis, apoptosis, cardiomyocyte size; decreased B-type natriuretic peptide gene expression; and preserved angiogenesis (all P<0.05, n=4-7/group). Mechanistically, we identified Jagged1, a Notch1 ligand, as a direct target of miR-652 by luciferase assay. Jagged1 and Notch1 mRNA were upregulated in hearts of TAC treated mice (1.2-1.7 fold, n=7, P<0.05). Importantly, chronic knockdown of miR-652 was not associated with any notable toxicity in other tissues.
Conclusion:
Therapeutic silencing of miR-652 protects the heart against pathological cardiac remodeling and improves heart function via mechanisms that are associated with preserved angiogenesis, decreased fibrosis and upregulation of a miR-652 target, Jagged1. These studies provide the first evidence that targeted inhibition of miR-652 could represent an attractive approach for the treatment of heart failure.
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Affiliation(s)
| | - Sally S Nguyen
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | | | - Xiao-Ming Gao
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | - Esther J Boey
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | - Yow Keat Tham
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | - Helen Kiriazis
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | | | - Ruby C Lin
- Univ of New South Wales, Sydney, Australia
| | - Xiao-Jun Du
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
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Bernardo BC, Gao XM, Tham YK, Kiriazis H, Winbanks CE, Ooi JYY, Boey EJH, Obad S, Kauppinen S, Gregorevic P, Du XJ, Lin RCY, McMullen JR. Silencing of miR-34a attenuates cardiac dysfunction in a setting of moderate, but not severe, hypertrophic cardiomyopathy. PLoS One 2014; 9:e90337. [PMID: 24587330 PMCID: PMC3937392 DOI: 10.1371/journal.pone.0090337] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Accepted: 01/29/2014] [Indexed: 01/13/2023] Open
Abstract
Therapeutic inhibition of the miR-34 family (miR-34a,-b,-c), or miR-34a alone, have emerged as promising strategies for the treatment of cardiac pathology. However, before advancing these approaches further for potential entry into the clinic, a more comprehensive assessment of the therapeutic potential of inhibiting miR-34a is required for two key reasons. First, miR-34a has ∼40% fewer predicted targets than the miR-34 family. Hence, in cardiac stress settings in which inhibition of miR-34a provides adequate protection, this approach is likely to result in less potential off-target effects. Secondly, silencing of miR-34a alone may be insufficient in settings of established cardiac pathology. We recently demonstrated that inhibition of the miR-34 family, but not miR-34a alone, provided benefit in a chronic model of myocardial infarction. Inhibition of miR-34 also attenuated cardiac remodeling and improved heart function following pressure overload, however, silencing of miR-34a alone was not examined. The aim of this study was to assess whether inhibition of miR-34a could attenuate cardiac remodeling in a mouse model with pre-existing pathological hypertrophy. Mice were subjected to pressure overload via constriction of the transverse aorta for four weeks and echocardiography was performed to confirm left ventricular hypertrophy and systolic dysfunction. After four weeks of pressure overload (before treatment), two distinct groups of animals became apparent: (1) mice with moderate pathology (fractional shortening decreased ∼20%) and (2) mice with severe pathology (fractional shortening decreased ∼37%). Mice were administered locked nucleic acid (LNA)-antimiR-34a or LNA-control with an eight week follow-up. Inhibition of miR-34a in mice with moderate cardiac pathology attenuated atrial enlargement and maintained cardiac function, but had no significant effect on fetal gene expression or cardiac fibrosis. Inhibition of miR-34a in mice with severe pathology provided no therapeutic benefit. Thus, therapies that inhibit miR-34a alone may have limited potential in settings of established cardiac pathology.
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Affiliation(s)
| | - Xiao-Ming Gao
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Yow Keat Tham
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Helen Kiriazis
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | - Jenny Y. Y. Ooi
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Esther J. H. Boey
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | | | - Sakari Kauppinen
- Department of Haematology, Aalborg University Hospital, Copenhagen, Denmark
| | - Paul Gregorevic
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
| | - Ruby C. Y. Lin
- Ramaciotti Centre for Genomics, School of Biotechnology & Biomolecular Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Julie R. McMullen
- Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- Departments of Medicine Monash University, Clayton, Victoria, Australia
- Departments of Physiology, Monash University, Clayton, Victoria, Australia
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Chen JL, Walton KL, Winbanks CE, Murphy KT, Thomson RE, Makanji Y, Qian H, Lynch GS, Harrison CA, Gregorevic P. Elevated expression of activins promotes muscle wasting and cachexia. FASEB J 2013; 28:1711-23. [PMID: 24378873 DOI: 10.1096/fj.13-245894] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In models of cancer cachexia, inhibiting type IIB activin receptors (ActRIIBs) reverse muscle wasting and prolongs survival, even with continued tumor growth. ActRIIB mediates signaling of numerous TGF-β proteins; of these, we demonstrate that activins are the most potent negative regulators of muscle mass. To determine whether activin signaling in the absence of tumor-derived factors induces cachexia, we used recombinant serotype 6 adeno-associated virus (rAAV6) vectors to increase circulating activin A levels in C57BL/6 mice. While mice injected with control vector gained ~10% of their starting body mass (3.8±0.4 g) over 10 wk, mice injected with increasing doses of rAAV6:activin A exhibited weight loss in a dose-dependent manner, to a maximum of -12.4% (-4.2±1.1 g). These reductions in body mass in rAAV6:activin-injected mice correlated inversely with elevated serum activin A levels (7- to 24-fold). Mechanistically, we show that activin A reduces muscle mass and function by stimulating the ActRIIB pathway, leading to deleterious consequences, including increased transcription of atrophy-related ubiquitin ligases, decreased Akt/mTOR-mediated protein synthesis, and a profibrotic response. Critically, we demonstrate that the muscle wasting and fibrosis that ensues in response to excessive activin levels is fully reversible. These findings highlight the therapeutic potential of targeting activins in cachexia.
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Affiliation(s)
- Justin L Chen
- 2Baker IDI Heart and Diabetes Institute, P.O. Box 6492, St. Kilda Rd. Central, Melbourne 8008, Australia.
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Winbanks CE, Chen JL, Qian H, Liu Y, Bernardo BC, Beyer C, Watt KI, Thomson RE, Connor T, Turner BJ, McMullen JR, Larsson L, Harrison CA, Gregorevic P. The bone morphogenetic protein axis is a positive regulator of skeletal muscle mass. J Exp Med 2013. [DOI: 10.1084/jem.21012oia54] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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10
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Winbanks CE, Chen JL, Qian H, Liu Y, Bernardo BC, Beyer C, Watt KI, Thomson RE, Connor T, Turner BJ, McMullen JR, Larsson L, McGee SL, Harrison CA, Gregorevic P. The bone morphogenetic protein axis is a positive regulator of skeletal muscle mass. ACTA ACUST UNITED AC 2013; 203:345-57. [PMID: 24145169 PMCID: PMC3812980 DOI: 10.1083/jcb.201211134] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The BMP signaling pathway promotes muscle growth and inhibits muscle wasting via SMAD1/5-dependent signaling. Although the canonical transforming growth factor β signaling pathway represses skeletal muscle growth and promotes muscle wasting, a role in muscle for the parallel bone morphogenetic protein (BMP) signaling pathway has not been defined. We report, for the first time, that the BMP pathway is a positive regulator of muscle mass. Increasing the expression of BMP7 or the activity of BMP receptors in muscles induced hypertrophy that was dependent on Smad1/5-mediated activation of mTOR signaling. In agreement, we observed that BMP signaling is augmented in models of muscle growth. Importantly, stimulation of BMP signaling is essential for conservation of muscle mass after disruption of the neuromuscular junction. Inhibiting the phosphorylation of Smad1/5 exacerbated denervation-induced muscle atrophy via an HDAC4-myogenin–dependent process, whereas increased BMP–Smad1/5 activity protected muscles from denervation-induced wasting. Our studies highlight a novel role for the BMP signaling pathway in promoting muscle growth and inhibiting muscle wasting, which may have significant implications for the development of therapeutics for neuromuscular disorders.
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Affiliation(s)
- Catherine E Winbanks
- Division of Cell Signaling and Metabolism, Baker IDI Heart and Diabetes Institute, Melbourne 3004, Australia
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11
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Winbanks CE, Beyer C, Hagg A, Qian H, Sepulveda PV, Gregorevic P. miR-206 represses hypertrophy of myogenic cells but not muscle fibers via inhibition of HDAC4. PLoS One 2013; 8:e73589. [PMID: 24023888 PMCID: PMC3759420 DOI: 10.1371/journal.pone.0073589] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 07/26/2013] [Indexed: 12/21/2022] Open
Abstract
microRNAs regulate the development of myogenic progenitors, and the formation of skeletal muscle fibers. However, the role miRNAs play in controlling the growth and adaptation of post-mitotic musculature is less clear. Here, we show that inhibition of the established pro-myogenic regulator miR-206 can promote hypertrophy and increased protein synthesis in post-mitotic cells of the myogenic lineage. We have previously demonstrated that histone deacetylase 4 (HDAC4) is a target of miR-206 in the regulation of myogenic differentiation. We confirmed that inhibition of miR-206 de-repressed HDAC4 accumulation in cultured myotubes. Importantly, inhibition of HDAC4 activity by valproic acid or sodium butyrate prevented hypertrophy of myogenic cells otherwise induced by inhibition of miR-206. To test the significance of miRNA-206 as a regulator of skeletal muscle mass in vivo, we designed recombinant adeno-associated viral vectors (rAAV6 vectors) expressing miR-206, or a miR-206 “sponge,” featuring repeats of a validated miR-206 target sequence. We observed that over-expression or inhibition of miR-206 in the muscles of mice decreased or increased endogenous HDAC4 levels respectively, but did not alter muscle mass or myofiber size. We subsequently manipulated miR-206 levels in muscles undergoing follistatin-induced hypertrophy or denervation-induced atrophy (models of muscle adaptation where endogenous miR-206 expression is altered). Vector-mediated manipulation of miR-206 activity in these models of cell growth and wasting did not alter gain or loss of muscle mass respectively. Our data demonstrate that although the miR-206/HDAC4 axis operates in skeletal muscle, the post-natal expression of miR-206 is not a key regulator of basal skeletal muscle mass or specific modes of muscle growth and wasting. These studies support a context-dependent role of miR-206 in regulating hypertrophy that may be dispensable for maintaining or modifying the adult skeletal muscle phenotype – an important consideration in relation to the development of therapeutics designed to manipulate microRNA activity in musculature.
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Affiliation(s)
- Catherine E. Winbanks
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- * E-mail: (PG); (CW)
| | - Claudia Beyer
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Adam Hagg
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- Department of Physiology, the University of Melbourne, Parkville, Australia
| | - Hongwei Qian
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Patricio V. Sepulveda
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Paul Gregorevic
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- Department of Neurology, The University of Washington School of Medicine, Seattle, Washington, United States of America
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Australia
- Department of Physiology, the University of Melbourne, Parkville, Australia
- * E-mail: (PG); (CW)
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Winbanks CE, Weeks KL, Thomson RE, Sepulveda PV, Beyer C, Qian H, Chen JL, Allen JM, Lancaster GI, Febbraio MA, Harrison CA, McMullen JR, Chamberlain JS, Gregorevic P. Follistatin-mediated skeletal muscle hypertrophy is regulated by Smad3 and mTOR independently of myostatin. ACTA ACUST UNITED AC 2012; 197:997-1008. [PMID: 22711699 PMCID: PMC3384410 DOI: 10.1083/jcb.201109091] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Follistatin is essential for skeletal muscle development and growth, but the intracellular signaling networks that regulate follistatin-mediated effects are not well defined. We show here that the administration of an adeno-associated viral vector expressing follistatin-288aa (rAAV6:Fst-288) markedly increased muscle mass and force-producing capacity concomitant with increased protein synthesis and mammalian target of rapamycin (mTOR) activation. These effects were attenuated by inhibition of mTOR or deletion of S6K1/2. Furthermore, we identify Smad3 as the critical intracellular link that mediates the effects of follistatin on mTOR signaling. Expression of constitutively active Smad3 not only markedly prevented skeletal muscle growth induced by follistatin but also potently suppressed follistatin-induced Akt/mTOR/S6K signaling. Importantly, the regulation of Smad3- and mTOR-dependent events by follistatin occurred independently of overexpression or knockout of myostatin, a key repressor of muscle development that can regulate Smad3 and mTOR signaling and that is itself inhibited by follistatin. These findings identify a critical role of Smad3/Akt/mTOR/S6K/S6RP signaling in follistatin-mediated muscle growth that operates independently of myostatin-driven mechanisms.
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Affiliation(s)
- Catherine E Winbanks
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Victoria 3004, Australia
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Wang B, Komers R, Carew R, Winbanks CE, Xu B, Herman-Edelstein M, Koh P, Thomas M, Jandeleit-Dahm K, Gregorevic P, Cooper ME, Kantharidis P. Suppression of microRNA-29 expression by TGF-β1 promotes collagen expression and renal fibrosis. J Am Soc Nephrol 2011; 23:252-65. [PMID: 22095944 DOI: 10.1681/asn.2011010055] [Citation(s) in RCA: 404] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Synthesis and deposition of extracellular matrix (ECM) within the glomerulus and interstitium characterizes renal fibrosis, but the mechanisms underlying this process are incompletely understood. The profibrotic cytokine TGF-β1 modulates the expression of certain microRNAs (miRNAs), suggesting that miRNAs may have a role in the pathogenesis of renal fibrosis. Here, we exposed proximal tubular cells, primary mesangial cells, and podocytes to TGF-β1 to examine its effect on miRNAs and subsequent collagen synthesis. TGF-β1 reduced expression of the miR-29a/b/c/family, which targets collagen gene expression, and increased expression of ECM proteins. In both resting and TGF-β1-treated cells, ectopic expression of miR-29 repressed the expression of collagens I and IV at both the mRNA and protein levels by targeting the 3'untranslated region of these genes. Furthermore, we observed low levels of miR-29 in three models of renal fibrosis representing early and advanced stages of disease. Administration of the Rho-associated kinase inhibitor fasudil prevented renal fibrosis and restored expression of miR-29. Taken together, these data suggest that TGF-β1 inhibits expression of the miR-29 family, thereby promoting expression of ECM components. Pharmacologic modulation of these miRNAs may have therapeutic potential for progressive renal fibrosis.
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Affiliation(s)
- Bo Wang
- JDRF Danielle Alberti Memorial Centre for Diabetes Complications, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
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Winbanks CE, Wang B, Beyer C, Koh P, White L, Kantharidis P, Gregorevic P. TGF-beta regulates miR-206 and miR-29 to control myogenic differentiation through regulation of HDAC4. J Biol Chem 2011; 286:13805-14. [PMID: 21324893 DOI: 10.1074/jbc.m110.192625] [Citation(s) in RCA: 218] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
MicroRNAs (miRs) are emerging as prominent players in the regulation of many biological processes, including myogenic commitment and skeletal muscle formation. Members of the TGF-β family can influence the proliferation and myogenic differentiation of cells, although it is presently not clear what role miRNAs play in the TGF-β-mediated control of myogenic differentiation. Here, we demonstrate in the myogenic C2C12 cell line, and in primary muscle cells, that miR-206 and miR-29-two miRs that act on transcriptional events implicated in muscle differentiation are down-regulated by TGF-β. We further demonstrate that TGF-β treatment of myogenic cells is associated with increased expression of histone deacetylase 4 (HDAC4), a key inhibitor of muscle differentiation that has been identified as a target for regulation by miR-206 and miR-29. We confirmed that increased expression of miR-206 and miR-29 resulted in the translational repression of HDAC4 in the presence or absence of TGF-β via interaction with the HDAC4 3'-untranslated region. Importantly, we found that miR-206 and miR-29 can attenuate the inhibitory actions of TGF-β on myogenic differentiation. Furthermore, we present evidence that the mechanism by which miR-206 and miR-29 can inhibit the TGF-β-mediated up-regulation of HDAC4 is via the inhibition of Smad3 expression, a transducer of TGF-β signaling. These findings identify a novel mechanism of interaction between TGF-β and miR-206 and -29 in the regulation of myogenic differentiation through HDAC4.
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Affiliation(s)
- Catherine E Winbanks
- Division of Metabolism and Obesity, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 8008, Australia
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15
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Buchert M, Athineos D, Abud HE, Burke ZD, Faux MC, Samuel MS, Jarnicki AG, Winbanks CE, Newton IP, Meniel VS, Suzuki H, Stacker SA, Näthke IS, Tosh D, Huelsken J, Clarke AR, Heath JK, Sansom OJ, Ernst M. Genetic dissection of differential signaling threshold requirements for the Wnt/beta-catenin pathway in vivo. PLoS Genet 2010; 6:e1000816. [PMID: 20084116 PMCID: PMC2800045 DOI: 10.1371/journal.pgen.1000816] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 12/15/2009] [Indexed: 12/29/2022] Open
Abstract
Contributions of null and hypomorphic alleles of Apc in mice produce both developmental and pathophysiological phenotypes. To ascribe the resulting genotype-to-phenotype relationship unambiguously to the Wnt/β-catenin pathway, we challenged the allele combinations by genetically restricting intracellular β-catenin expression in the corresponding compound mutant mice. Subsequent evaluation of the extent of resulting Tcf4-reporter activity in mouse embryo fibroblasts enabled genetic measurement of Wnt/β-catenin signaling in the form of an allelic series of mouse mutants. Different permissive Wnt signaling thresholds appear to be required for the embryonic development of head structures, adult intestinal polyposis, hepatocellular carcinomas, liver zonation, and the development of natural killer cells. Furthermore, we identify a homozygous Apc allele combination with Wnt/β-catenin signaling capacity similar to that in the germline of the Apcmin mice, where somatic Apc loss-of-heterozygosity triggers intestinal polyposis, to distinguish whether co-morbidities in Apcmin mice arise independently of intestinal tumorigenesis. Together, the present genotype–phenotype analysis suggests tissue-specific response levels for the Wnt/β-catenin pathway that regulate both physiological and pathophysiological conditions. Germline or somatic mutations in genes are the underlying cause of many human diseases, most notably cancer. Interestingly though, even in situations where every cell of every tissue of an organism carries the same mutation (as is the case for germline mutations), some tissues are more susceptible to the development of disease over time than others. For example, in familial adenomatous polyposis (FAP), affected persons carry different germline mutations in the APC gene and are prone to developing cancers of the colon and the rectum—and, less frequently, cancers in other tissues such as stomach, liver, and bones. Here we utilize a panel of mutant mice with truncating or hypomorphic mutations in the Apc gene, resulting in different levels of activation of the Wnt/β-catenin pathway. Our results reveal that different pathophysiological outcomes depend on different permissive signaling thresholds in embryonic, intestinal, and liver tissues. Importantly, we demonstrate that reducing Wnt pathway activation by 50% is enough to prevent the manifestation of embryonic abnormalities and disease in the adult mouse. This raises the possibility of developing therapeutic strategies that modulate the activation levels of this pathway rather than trying to “repair” the mutation in the gene itself.
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Affiliation(s)
- Michael Buchert
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
| | - Dimitris Athineos
- The Beatson Institute Cancer Research, Garscube Estate, Glasgow, United Kingdom
| | - Helen E. Abud
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
- Department of Anatomy and Cell Biology, University of Melbourne, Melbourne, Australia
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia
| | - Zoe D. Burke
- Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Maree C. Faux
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
| | - Michael S. Samuel
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
- The Beatson Institute Cancer Research, Garscube Estate, Glasgow, United Kingdom
| | - Andrew G. Jarnicki
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
| | | | - Ian P. Newton
- Cell and Developmental Biology, University of Dundee, Dundee, United Kingdom
| | - Valerie S. Meniel
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Hiromu Suzuki
- First Department of Internal Medicine, Sapporo Medical University, Sapporo, Japan
| | - Steven A. Stacker
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
| | - Inke S. Näthke
- Cell and Developmental Biology, University of Dundee, Dundee, United Kingdom
| | - David Tosh
- Centre for Regenerative Medicine, Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Joerg Huelsken
- Ecole Polytechnique Fédérale de Lausanne, Swiss Institute for Experimental Cancer Research, Lausanne, Switzerland
| | - Alan R. Clarke
- School of Biosciences, University of Cardiff, Cardiff, United Kingdom
| | - Joan K. Heath
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
| | - Owen J. Sansom
- The Beatson Institute Cancer Research, Garscube Estate, Glasgow, United Kingdom
- * E-mail: (ME); (OS)
| | - Matthias Ernst
- Ludwig Institute for Cancer Research, Royal Melbourne Hospital, Parkville, Australia
- * E-mail: (ME); (OS)
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Abstract
Glycoconjugates are complex macromolecules present in all tissues throughout the body. Depending on the tissue region, glycoconjugates express different carbohydrate moieties, which can be used to both distinguish cell type and examine changes in cell phenotype.Although the periodic acid-schiff (PAS) method has long been used to study the distribution of glycoconjugates, the usefulness of the technique is severely limited by its lack of specificity. A more specific technique makes use of the affinity that plant-derived lectins have for different carbohydrate moieties in glycoconjugates. Binding of lectins is therefore a particularly useful adjunct to conventional histology when it is important to characterise cell type. These well-characterised binding patterns have proved particularly valuable in helping us understand the pathogenesis of kidney disease, changes in cell surface carbohydrates on normal and neoplastic cells in tumours, and blood group biology.When labeled with a reporter molecule such as biotin or gold, lectin binding can be easily identified using light and electron microscopy. In this chapter, we describe the appropriate experimental protocols for light and electron microscopic examination of lectin binding, emphasising their utility in characterising nephron segments in renal disease.
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Affiliation(s)
- Su Ee Wong
- Department of Nephrology, The Royal Melbourne Hospital, Melbourne, VIC, Australia
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Winbanks CE, Grimwood L, Gasser A, Darby IA, Hewitson TD, Becker GJ. Role of the phosphatidylinositol 3-kinase and mTOR pathways in the regulation of renal fibroblast function and differentiation. Int J Biochem Cell Biol 2007; 39:206-19. [PMID: 16973406 DOI: 10.1016/j.biocel.2006.08.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 07/31/2006] [Accepted: 08/08/2006] [Indexed: 11/19/2022]
Abstract
Tubulointerstitial fibrosis is largely mediated by (myo)fibroblasts present in the interstitium. In this study, we investigated the role of mTOR and phosphatidylinositol 3-kinase in the regulation of fibroblast kinetics, fibroblast differentiation, and collagen synthesis. Rat renal fibroblasts were propagated from kidneys 3 days post-ureteric obstruction and specific inhibitors of mTOR (RAD) and phosphatidylinositol 3-kinase (LY294002) were used to examine the regulation of fibrogenesis. LY294002 but not RAD completely inhibited phosphorylation of Akt, while both inhibitors decreased phosphorylation of the S6 ribosomal protein. RAD and LY decreased foetal calf serum stimulated proliferation and DNA synthesis. In addition to their individual effects, treatment with both RAD and LY294002 decreased serum-induced fibroblast proliferation and DNA synthesis significantly more than either drug alone. TUNEL positive cells (apoptosis) in RAD and LY294002 treated groups were not different from control groups. In addition to their effect on proliferation, both inhibitors also reduced total collagen synthesis. Differentiation studies indicated an increase in alpha-smooth muscle actin expression relative to beta-actin (western blotting), with cytochemistry confirming that all doses of RAD and LY294002 increased the proportion of alpha-smooth muscle actin positive cells, and hence myofibroblasts. Effects were independent of cell toxicity. These results highlight the potential significance of PI3K and mTOR, in the regulation of renal (myo)fibroblast activity. The synergistic effects of LY and RAD on proliferation suggest that mTOR signalling involves pathways other than phosphatidylinositol 3-kinase. These results provide a novel insight into the mechanisms of fibroblast regulation during fibrogenesis.
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Affiliation(s)
- Catherine E Winbanks
- Department of Nephrology, The Royal Melbourne Hospital, Parkville, Vic. 3050, Australia
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