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Gremminger VL, Harrelson EN, Crawford TK, Ohler A, Schulz LC, Rector RS, Phillips CL. Skeletal muscle specific mitochondrial dysfunction and altered energy metabolism in a murine model (oim/oim) of severe osteogenesis imperfecta. Mol Genet Metab 2021; 132:244-253. [PMID: 33674196 PMCID: PMC8135105 DOI: 10.1016/j.ymgme.2021.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 02/05/2021] [Accepted: 02/13/2021] [Indexed: 12/24/2022]
Abstract
Osteogenesis imperfecta (OI) is a heritable connective tissue disorder with patients exhibiting bone fragility and muscle weakness. The synergistic biochemical and biomechanical relationship between bone and muscle is a critical potential therapeutic target, such that muscle weakness should not be ignored. Previous studies demonstrated mitochondrial dysfunction in the skeletal muscle of oim/oim mice, which model a severe human type III OI. Here, we further characterize this mitochondrial dysfunction and evaluate several parameters of whole body and skeletal muscle metabolism. We demonstrate reduced mitochondrial respiration in female gastrocnemius muscle, but not in liver or heart mitochondria, suggesting that mitochondrial dysfunction is not global in the oim/oim mouse. Myosin heavy chain fiber type distributions were altered in the oim/oim soleus muscle with a decrease (-33 to 50%) in type I myofibers and an increase (+31%) in type IIa myofibers relative to their wildtype (WT) littermates. Additionally, altered body composition and increased energy expenditure were observed oim/oim mice relative to WT littermates. These results suggest that skeletal muscle mitochondrial dysfunction is linked to whole body metabolic alterations and to skeletal muscle weakness in the oim/oim mouse.
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Affiliation(s)
- Victoria L Gremminger
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, United States of America
| | - Emily N Harrelson
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, United States of America
| | - Tara K Crawford
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, United States of America
| | - Adrienne Ohler
- Department of Child Health, University of Missouri, Columbia, MO 65211, United States of America
| | - Laura C Schulz
- Department of Obstetrics, Gynecology, and Women's Health, University of Missouri, Columbia, MO 65211, United States of America
| | - R Scott Rector
- Departments of Nutrition and Exercise Physiology and Medicine-GI, University of Missouri, Harry S Truman Memorial VA Hospital, Columbia, MO 65211, United States of America
| | - Charlotte L Phillips
- Department of Biochemistry, University of Missouri, Columbia, MO 65211, United States of America; Department of Child Health, University of Missouri, Columbia, MO 65211, United States of America.
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Omosule CL, Gremminger VL, Aguillard AM, Jeong Y, Harrelson EN, Miloscio L, Mastaitis J, Rafique A, Kleiner S, Pfeiffer FM, Zhang A, Schulz LC, Phillips CL. Impact of Genetic and Pharmacologic Inhibition of Myostatin in a Murine Model of Osteogenesis Imperfecta. J Bone Miner Res 2021; 36:739-756. [PMID: 33249643 PMCID: PMC8111798 DOI: 10.1002/jbmr.4223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 01/05/2023]
Abstract
Osteogenesis imperfecta (OI) is a genetic connective tissue disorder characterized by compromised skeletal integrity, altered microarchitecture, and bone fragility. Current OI treatment strategies focus on bone antiresorptives and surgical intervention with limited effectiveness, and thus identifying alternative therapeutic options remains critical. Muscle is an important stimulus for bone formation. Myostatin, a TGF-β superfamily myokine, acts through ActRIIB to negatively regulate muscle growth. Recent studies demonstrated the potential benefit of myostatin inhibition with the soluble ActRIIB fusion protein on skeletal properties, although various OI mouse models exhibited variable skeletal responses. The genetic and clinical heterogeneity associated with OI, the lack of specificity of the ActRIIB decoy molecule for myostatin alone, and adverse events in human clinical trials further the need to clarify myostatin's therapeutic potential and role in skeletal integrity. In this study, we determined musculoskeletal outcomes of genetic myostatin deficiency and postnatal pharmacological myostatin inhibition by a monoclonal anti-myostatin antibody (Regn647) in the G610C mouse, a model of mild-moderate type I/IV human OI. In the postnatal study, 5-week-old wild-type and +/G610C male and female littermates were treated with Regn647 or a control antibody for 11 weeks or for 7 weeks followed by a 4-week treatment holiday. Inhibition of myostatin, whether genetically or pharmacologically, increased muscle mass regardless of OI genotype, although to varying degrees. Genetic myostatin deficiency increased hindlimb muscle weights by 6.9% to 34.4%, whereas pharmacological inhibition increased them by 13.5% to 29.6%. Female +/mstn +/G610C (Dbl.Het) mice tended to have similar trabecular and cortical bone parameters as Wt showing reversal of +/G610C characteristics but with minimal effect of +/mstn occurring in male mice. Pharmacologic myostatin inhibition failed to improve skeletal bone properties of male or female +/G610C mice, although skeletal microarchitectural and biomechanical improvements were observed in male wild-type mice. Four-week treatment holiday did not alter skeletal outcomes. © 2020 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
| | | | | | - Youngjae Jeong
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
| | - Emily N Harrelson
- Department of Biochemistry, University of Missouri, Columbia, MO, USA
| | | | | | | | | | - Ferris M Pfeiffer
- Department of Biomedical, Biological, and Chemical Engineering, University of Missouri, Columbia, MO, USA
| | - Anqing Zhang
- Department of Biostatistics and Research Design, University of Missouri, Columbia, MO, USA
| | - Laura C Schulz
- Department of Obstetrics, Gynecology, and Women's Health, University of Missouri, Columbia, MO, USA
| | - Charlotte L Phillips
- Department of Biochemistry, University of Missouri, Columbia, MO, USA.,Department of Child Health, University of Missouri, Columbia, MO, USA
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