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Ema R, Wakahara T, Miyamoto N, Kanehisa H, Kawakami Y. Inhomogeneous architectural changes of the quadriceps femoris induced by resistance training. Eur J Appl Physiol 2013; 113:2691-703. [PMID: 23949789 DOI: 10.1007/s00421-013-2700-1] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/23/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Ryoichi Ema
- Graduate School of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan
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202
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Trajcevski KE, O’Neill HM, Wang DC, Thomas MM, Al-Sajee D, Steinberg GR, Ceddia RB, Hawke TJ. Enhanced lipid oxidation and maintenance of muscle insulin sensitivity despite glucose intolerance in a diet-induced obesity mouse model. PLoS One 2013; 8:e71747. [PMID: 23951235 PMCID: PMC3741110 DOI: 10.1371/journal.pone.0071747] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/03/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Diet-induced obesity is a rising health concern which can lead to the development of glucose intolerance and muscle insulin resistance and, ultimately, type II diabetes mellitus. This research investigates the associations between glucose intolerance or muscle insulin resistance and tissue specific changes during the progression of diet-induced obesity. METHODOLOGY C57BL/6J mice were fed a normal or high-fat diet (HFD; 60% kcal fat) for 3 or 8 weeks. Disease progression was monitored by measurements of body/tissue mass changes, glucose and insulin tolerance tests, and ex vivo glucose uptake in intact muscles. Lipid metabolism was analyzed using metabolic chambers and ex vivo palmitate assays in intact muscles. Skeletal muscle, liver and adipose tissues were analyzed for changes in inflammatory gene expression. Plasma was analyzed for insulin levels and inflammatory proteins. Histological techniques were used on muscle and liver cryosections to assess metabolic and morphological changes. PRINCIPAL FINDINGS/CONCLUSIONS A rapid shift in whole body metabolism towards lipids was observed with HFD. Following 3 weeks of HFD, elevated total lipid oxidation and an oxidative fiber type shift had occurred in the skeletal muscle, which we propose was responsible for delaying intramyocellular lipid accumulation and maintaining muscle's insulin sensitivity. Glucose intolerance was present after three weeks of HFD and was associated with an enlarged adipose tissue depot, adipose tissue inflammation and excess hepatic lipids, but not hepatic inflammation. Furthermore, HFD did not significantly increase systemic or muscle inflammation after 3 or 8 weeks of HFD suggesting that early diet-induced obesity does not cause inflammation throughout the whole body. Overall these findings indicate skeletal muscle did not contribute to the development of HFD-induced impairments in whole-body glucose tolerance following 3 weeks of HFD.
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Affiliation(s)
- Karin E. Trajcevski
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Hayley M. O’Neill
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - David C. Wang
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Melissa M. Thomas
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Dhuha Al-Sajee
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | | | - Rolando B. Ceddia
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Thomas J. Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada
- * E-mail:
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203
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Krause MP, Al-Sajee D, D’Souza DM, Rebalka IA, Moradi J, Riddell MC, Hawke TJ. Impaired macrophage and satellite cell infiltration occurs in a muscle-specific fashion following injury in diabetic skeletal muscle. PLoS One 2013; 8:e70971. [PMID: 23951058 PMCID: PMC3741394 DOI: 10.1371/journal.pone.0070971] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 06/26/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Systemic elevations in PAI-1 suppress the fibrinolytic pathway leading to poor collagen remodelling and delayed regeneration of tibialis anterior (TA) muscles in type-1 diabetic Akita mice. However, how impaired collagen remodelling was specifically attenuating regeneration in Akita mice remained unknown. Furthermore, given intrinsic differences between muscle groups, it was unclear if the reparative responses between muscle groups were different. PRINCIPAL FINDINGS Here we reveal that diabetic Akita muscles display differential regenerative responses with the TA and gastrocnemius muscles exhibiting reduced regenerating myofiber area compared to wild-type mice, while soleus muscles displayed no difference between animal groups following injury. Collagen levels in TA and gastrocnemius, but not soleus, were significantly increased post-injury versus controls. At 5 days post-injury, when degenerating/necrotic regions were present in both animal groups, Akita TA and gastrocnemius muscles displayed reduced macrophage and satellite cell infiltration and poor myofiber formation. By 10 days post-injury, necrotic regions were absent in wild-type TA but persisted in Akita TA. In contrast, Akita soleus exhibited no impairment in any of these measures compared to wild-type soleus. In an effort to define how impaired collagen turnover was attenuating regeneration in Akita TA, a PAI-1 inhibitor (PAI-039) was orally administered to Akita mice following cardiotoxin injury. PAI-039 administration promoted macrophage and satellite cell infiltration into necrotic areas of the TA and gastrocnemius. Importantly, soleus muscles exhibit the highest inducible expression of MMP-9 following injury, providing a mechanism for normative collagen degradation and injury recovery in this muscle despite systemically elevated PAI-1. CONCLUSIONS Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed regeneration is an impairment in macrophage infiltration and satellite cell recruitment to degenerating areas; a phenomena that occurs differentially between muscle groups.
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Affiliation(s)
- Matthew P. Krause
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Dhuha Al-Sajee
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Donna M. D’Souza
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Irena A. Rebalka
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jasmin Moradi
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael C. Riddell
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada
| | - Thomas J. Hawke
- Department of Pathology & Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
- Muscle Health Research Centre, York University, Toronto, Ontario, Canada
- * E-mail:
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204
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Larkin LM, Hanes MC, Kayupov E, Claflin DR, Faulkner JA, Brooks SV. Weakness of whole muscles in mice deficient in Cu, Zn superoxide dismutase is not explained by defects at the level of the contractile apparatus. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1173-1181. [PMID: 22696118 PMCID: PMC3705120 DOI: 10.1007/s11357-012-9441-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 05/21/2012] [Indexed: 06/01/2023]
Abstract
Mice deficient in Cu,Zn superoxide dismutase (Sod1 (-/-) mice) demonstrate elevated oxidative stress associated with rapid age-related declines in muscle mass and force. The decline in mass for muscles of Sod1 (-/-) mice is explained by a loss of muscle fibers, but the mechanism underlying the weakness is not clear. We hypothesized that the reduced maximum isometric force (F o) normalized by cross-sectional area (specific F o) for whole muscles of Sod1 (-/-) compared with wild-type (WT) mice is due to decreased specific F o of individual fibers. Force generation was measured for permeabilized fibers from muscles of Sod1 (-/-) and WT mice at 8 and 20 months of age. WT mice were also studied at 28 months to determine whether any deficits observed for fibers from Sod1 (-/-) mice were similar to those observed in old WT mice. No effects of genotype were observed for F o or specific F o at either 8 or 20 months, and no age-associated decrease in specific F o was observed for fibers from Sod1 (-/-) mice, whereas specific F o for fibers of WT mice decreased by 20 % by 28 months. Oxidative stress has also been associated with decreased maximum velocity of shortening (V max), and we found a 10 % lower V max for fibers from Sod1 (-/-) compared with WT mice at 20 months. We conclude that the low specific F o of muscles of Sod1 (-/-) mice is not explained by damage to contractile proteins. Moreover, the properties of fibers of Sod1 (-/-) mice do not recapitulate those observed with aging in WT animals.
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Affiliation(s)
- Lisa M. Larkin
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Michael C. Hanes
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
| | - Erdan Kayupov
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Dennis R. Claflin
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
- />Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI 48109 USA
| | - John A. Faulkner
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
| | - Susan V. Brooks
- />Departments of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-2200 USA
- />Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109 USA
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205
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Yeo SH, Monroy JA, Lappin AK, Nishikawa KC, Pai DK. Phenomenological models of the dynamics of muscle during isotonic shortening. J Biomech 2013; 46:2419-25. [PMID: 23938056 DOI: 10.1016/j.jbiomech.2013.07.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 06/11/2013] [Accepted: 07/14/2013] [Indexed: 11/19/2022]
Abstract
We investigated the effectiveness of simple, Hill-type, phenomenological models of the force-length-velocity relationship for simulating measured length trajectories during muscle shortening, and, if so, what forms of the model are most useful. Using isotonic shortening data from mouse soleus and toad depressor mandibulae muscles, we showed that Hill-type models can indeed simulate the shortening trajectories with sufficiently good accuracy. However, we found that the standard form of the Hill-type muscle model, called the force-scaling model, is not a satisfactory choice. Instead, the results support the use of less frequently used models, the f-max scaling model and force-scaling with parallel spring, to simulate the shortening dynamics of muscle.
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Affiliation(s)
- Sang Hoon Yeo
- Department of Computer Science, University of British Columbia, 201-2366 Main Mall, Vancouver, British Columbia, Canada V6T 1Z4
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206
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Stamenkovic A, Munro BJ, Peoples GE. Physiological cross-sectional area of the oblique head of the adductor pollicis is greater than its transverse counterpart: implications for functional testing. Muscle Nerve 2013; 49:405-12. [PMID: 23836250 DOI: 10.1002/mus.23933] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2013] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Despite structural distinction between the transverse and oblique heads of the adductor pollicis, in vivo testing continues to consider the adductor pollicis as functionally simplistic. As a muscle's architecture is a strong indicator of function, in this study we aimed to determine whether the physiological cross-sectional areas (PCSAs) of both heads were uniform. METHODS Classical, microdissection, and chemical dissection procedures were conducted on 10 cadaveric left hands to determine structural origin and insertions. Architectural measures of muscle length (Lm ), muscle weight (Wm ), fascicle length (Lf ), sarcomere length (Ls ), and pennation angle (θ) were used to calculate PCSA and fascicle length:muscle length ratio (Lf :Lm ). RESULTS The oblique head had greater variation in attachments, significantly greater PCSA (P = 0.008), and smaller Lf :Lm (P = 0.001) than its transverse counterpart. CONCLUSIONS Muscle architecture suggests the oblique head has greater potential for force generation, and the transverse has greater potential for joint excursion.
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Affiliation(s)
- Alexander Stamenkovic
- Neural Control of Movement Laboratory, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia; Biomechanics Research Laboratory, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales, Australia; Human Anatomy Laboratory, Faculty of Science, Medicine and Health, University of Wollongong, Northfields Avenue, Wollongong, New South Wales, 2522, Australia
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207
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Randhawa A, Wakeling JM. Associations between muscle structure and contractile performance in seniors. Clin Biomech (Bristol, Avon) 2013; 28:705-11. [PMID: 23787033 DOI: 10.1016/j.clinbiomech.2013.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/27/2013] [Accepted: 04/29/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Changes in muscle structure due to aging occur in a process known as sarcopenia. These changes can alter muscle mechanics during contraction that may limit mobility in seniors. The purpose of this study was to investigate the effect of sarcopenia on muscle fascicle length, pennation and belly thickness in a contracting muscle during isokinetic movements. Fascicles within a pennate muscle shorten at a slower velocity than that of the muscle belly, in a process called belly gearing. Belly gearing may be affected by atrophy and so was also tested in these seniors. METHODS The gastrocnemii were tested using ultrasound from 10 young adults (20-40 years) and 9 seniors (70-85 years). The muscle structure was imaged during standing and maximal plantarflexion at four constant velocities on a dynamometer and torque, position and time were recorded during contractions. FINDINGS The muscle belly thickness and pennation in seniors were significantly lower than young adults during standing. Belly thickness, changes in pennation, the belly gearing, ankle torque and power output were all significantly lower in seniors during plantarflexion contractions of the medial gastrocnemius (MG) and lateral gastrocnemius (LG). INTERPRETATION The higher pennation observed in young adults is commonly associated with increased fascicle rotations during contraction causing an increased belly gearing. The decreased fascicle rotations in seniors resulted in reduced belly gearing but the size of this effect did not match the loss in strength or power from the muscles.
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Affiliation(s)
- Avleen Randhawa
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
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208
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Lieber RL, Ward SR. Cellular mechanisms of tissue fibrosis. 4. Structural and functional consequences of skeletal muscle fibrosis. Am J Physiol Cell Physiol 2013; 305:C241-52. [PMID: 23761627 DOI: 10.1152/ajpcell.00173.2013] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Skeletal muscle fibrosis can be a devastating clinical problem that arises from many causes, including primary skeletal muscle tissue diseases, as seen in the muscular dystrophies, or it can be secondary to events that include trauma to muscle or brain injury. The cellular source of activated fibroblasts (myofibroblasts) may include resident fibroblasts, adult muscle stem cells, or inflammatory or perivascular cells, depending on the model studied. Even though it is likely that there is no single source for all myofibroblasts, a common mechanism for the production of fibrosis is via the transforming growth factor-β/phosphorylated Smad3 pathway. This pathway and its downstream targets thus provide loci for antifibrotic therapies, as do methods for blocking the transdifferentiation of progenitors into activated fibroblasts. A structural model for the extracellular collagen network of skeletal muscle is needed so that measurements of collagen content, morphology, and gene expression can be related to mechanical properties. Approaches used to study fibrosis in tissues, such as lung, kidney, and liver, need to be applied to studies of skeletal muscle to identify ways to prevent or even cure the devastating maladies of skeletal muscle.
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Affiliation(s)
- Richard L Lieber
- Department of Orthopaedic Surgery, University of California San Diego, San Diego, California 92093-0863, USA.
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209
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Ottenheijm CAC, Buck D, de Winter JM, Ferrara C, Piroddi N, Tesi C, Jasper JR, Malik FI, Meng H, Stienen GJM, Beggs AH, Labeit S, Poggesi C, Lawlor MW, Granzier H. Deleting exon 55 from the nebulin gene induces severe muscle weakness in a mouse model for nemaline myopathy. ACTA ACUST UNITED AC 2013; 136:1718-31. [PMID: 23715096 DOI: 10.1093/brain/awt113] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nebulin--a giant sarcomeric protein--plays a pivotal role in skeletal muscle contractility by specifying thin filament length and function. Although mutations in the gene encoding nebulin (NEB) are a frequent cause of nemaline myopathy, the most common non-dystrophic congenital myopathy, the mechanisms by which mutations in NEB cause muscle weakness remain largely unknown. To better understand these mechanisms, we have generated a mouse model in which Neb exon 55 is deleted (Neb(ΔExon55)) to replicate a founder mutation seen frequently in patients with nemaline myopathy with Ashkenazi Jewish heritage. Neb(ΔExon55) mice are born close to Mendelian ratios, but show growth retardation after birth. Electron microscopy studies show nemaline bodies--a hallmark feature of nemaline myopathy--in muscle fibres from Neb(ΔExon55) mice. Western blotting studies with nebulin-specific antibodies reveal reduced nebulin levels in muscle from Neb(ΔExon55) mice, and immunofluorescence confocal microscopy studies with tropomodulin antibodies and phalloidin reveal that thin filament length is significantly reduced. In line with reduced thin filament length, the maximal force generating capacity of permeabilized muscle fibres and single myofibrils is reduced in Neb(ΔExon55) mice with a more pronounced reduction at longer sarcomere lengths. Finally, in Neb(ΔExon55) mice the regulation of contraction is impaired, as evidenced by marked changes in crossbridge cycling kinetics and by a reduction of the calcium sensitivity of force generation. A novel drug that facilitates calcium binding to the thin filament significantly augmented the calcium sensitivity of submaximal force to levels that exceed those observed in untreated control muscle. In conclusion, we have characterized the first nebulin-based nemaline myopathy model, which recapitulates important features of the phenotype observed in patients harbouring this particular mutation, and which has severe muscle weakness caused by thin filament dysfunction.
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Affiliation(s)
- Coen A C Ottenheijm
- Department of Physiology, VU University Medical Centre, Amsterdam, The Netherlands
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210
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Rahnert JA, Burkholder TJ. High-frequency electrical stimulation reveals a p38-mTOR signaling module correlated with force-time integral. ACTA ACUST UNITED AC 2013; 216:2619-31. [PMID: 23531822 DOI: 10.1242/jeb.080705] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
High-frequency electrical stimulation (HFES) leads to muscle hypertrophy, and attention has been drawn to the high forces involved. However, both mechanical and metabolic stresses occur simultaneously, and both stimuli influence signaling cascades related to protein synthesis. This study aimed to identify the immediate signaling correlates of contraction-induced force and metabolic stresses under the hypothesis that HFES induces growth-related signaling through mechanical stimulation. Force-time integral (FTI) signaling in mouse tibialis anterior muscle was examined by separately manipulating the time of contraction to emphasize the metabolic aspect or the force of contraction to emphasize the mechanical aspect. When FTI was manipulated by changing the total time of activation, phosphorylation of p54 JNK, ERK and p70S6k(T421/S424) was independent of FTI, while phosphorylation of acetyl-CoA carboxylase and p38 correlated with FTI. When FTI was manipulated by changing the force of contraction, p54 JNK, ERK and p70S6k(T421/S424) were again independent of FTI, while phosphorylation of p38 and FAK correlated with FTI. Factor analysis identified a p38-mTOR signaling module that correlated with FTI in both experiments. The consistent link among p38, mTOR and FTI suggests that they form a connected signaling module sensitive to the mechanical aspects of FTI, separate from markers of metabolic load.
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Affiliation(s)
- Jill A Rahnert
- School of Applied Physiology, Georgia Institute of Technology, 555 14th Street NW, Atlanta, GA 30332-0356, USA
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211
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Ema R, Wakahara T, Mogi Y, Miyamoto N, Komatsu T, Kanehisa H, Kawakami Y. In vivomeasurement of human rectus femoris architecture by ultrasonography: validity and applicability. Clin Physiol Funct Imaging 2013; 33:267-73. [DOI: 10.1111/cpf.12023] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/20/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Ryoichi Ema
- Graduate School of Sport Sciences; Waseda University; Saitama; Japan
| | - Taku Wakahara
- Faculty of Sport Sciences; Waseda University; Saitama; Japan
| | - Yasuyoshi Mogi
- Graduate School of Sport Sciences; Waseda University; Saitama; Japan
| | | | - Toshihiko Komatsu
- Center for Education in Liberal Arts and Sciences, Osaka University; Osaka; Japan
| | - Hiroaki Kanehisa
- National Institute of Fitness and Sports in Kanoya; Kagoshima; Japan
| | - Yasuo Kawakami
- Faculty of Sport Sciences; Waseda University; Saitama; Japan
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212
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Shi Y, Pulliam DA, Liu Y, Hamilton RT, Jernigan AL, Bhattacharya A, Sloane LB, Qi W, Chaudhuri A, Buffenstein R, Ungvari Z, Austad SN, Van Remmen H. Reduced mitochondrial ROS, enhanced antioxidant defense, and distinct age-related changes in oxidative damage in muscles of long-lived Peromyscus leucopus. Am J Physiol Regul Integr Comp Physiol 2013; 304:R343-55. [PMID: 23325454 DOI: 10.1152/ajpregu.00139.2012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Comparing biological processes in closely related species with divergent life spans is a powerful approach to study mechanisms of aging. The oxidative stress hypothesis of aging predicts that longer-lived species would have lower reactive oxygen species (ROS) generation and/or an increased antioxidant capacity, resulting in reduced oxidative damage with age than in shorter-lived species. In this study, we measured ROS generation in the young adult animals of the long-lived white-footed mouse, Peromyscus leucopus (maximal life span potential, MLSP = 8 yr) and the common laboratory mouse, Mus musculus (C57BL/6J strain; MLSP = 3.5 yr). Consistent with the hypothesis, our results show that skeletal muscle mitochondria from adult P. leucopus produce less ROS (superoxide and hydrogen peroxide) compared with M. musculus. Additionally, P. leucopus has an increase in the activity of antioxidant enzymes superoxide dismutase 1, catalase, and glutathione peroxidase 1 at young age. P. leucopus compared with M. musculus display low levels of lipid peroxidation (isoprostanes) throughout life; however, P. leucopus although having elevated protein carbonyls at a young age, the accrual of protein oxidation with age is minimal in contrast to the linear increase in M. musculus. Altogether, the results from young animals are in agreement with the predictions of the oxidative stress hypothesis of aging with the exception of protein carbonyls. Nonetheless, the age-dependent increase in protein carbonyls is more pronounced in short-lived M. musculus, which supports enhanced protein homeostasis in long-lived P. leucopus.
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Affiliation(s)
- Yun Shi
- Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX 78245, USA
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213
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Ching JK, Spears LD, Armon JL, Renth AL, Andrisse S, Collins RL, Fisher JS. Impaired insulin-stimulated glucose transport in ATM-deficient mouse skeletal muscle. Appl Physiol Nutr Metab 2012; 38:589-96. [PMID: 23724874 DOI: 10.1139/apnm-2012-0175] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There are reports that ataxia telangiectasia mutated (ATM) plays a role in insulin-stimulated Akt phosphorylation, although this is not the case in some cell types. Because Akt plays a key role in insulin signaling, which leads to glucose transport in skeletal muscle, the predominant tissue in insulin-stimulated glucose disposal, we examined whether insulin-stimulated Akt phosphorylation and (or) glucose transport would be decreased in skeletal muscle of mice lacking functional ATM, compared with muscle from wild-type mice. We found that in vitro insulin-stimulated Akt phosphorylation was normal in soleus muscle from mice with 1 nonfunctional allele of ATM (ATM+/-) and from mice with 2 nonfunctional alleles (ATM-/-). However, insulin did not stimulate glucose transport or the phosphorylation of AS160 in ATM-/- soleus. ATM protein level was markedly higher in wild-type extensor digitorum longus (EDL) than in wild-type soleus. In EDL from ATM-/- mice, insulin did not stimulate glucose transport. However, in contrast to findings for soleus, insulin-stimulated Akt phosphorylation was blunted in ATM-/- EDL, concomitant with a tendency for insulin-stimulated phosphatidylinositol 3-kinase activity to be decreased. Together, the findings suggest that ATM plays a role in insulin-stimulated glucose transport at the level of AS160 in muscle comprised of slow and fast oxidative-glycolytic fibers (soleus) and at the level of Akt in muscle containing fast glycolytic fibers (EDL).
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Affiliation(s)
- James Kain Ching
- Department of Biology, Saint Louis University, 3507 Laclede Ave., St. Louis, MO 63103, USA
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214
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Radzyukevich TL, Neumann JC, Rindler TN, Oshiro N, Goldhamer DJ, Lingrel JB, Heiny JA. Tissue-specific role of the Na,K-ATPase α2 isozyme in skeletal muscle. J Biol Chem 2012. [PMID: 23192345 DOI: 10.1074/jbc.m112.424663] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Na,K-ATPase α2 isozyme is the major Na,K-ATPase of mammalian skeletal muscle. This distribution is unique compared with most other cells, which express mainly the Na,K-ATPase α1 isoform, but its functional significance is not known. We developed a gene-targeted mouse (skα2(-/-)) in which the α2 gene (Atp1a2) is knocked out in the skeletal muscles, and examined the consequences for exercise performance, membrane potentials, contractility, and muscle fatigue. Targeted knockout was confirmed by genotyping, Western blot, and immunohistochemistry. Skeletal muscle cells of skα2(-/-) mice completely lack α2 protein and have no α2 in the transverse tubules, where its expression is normally enhanced. The α1 isoform, which is normally enhanced on the outer sarcolemma, is up-regulated 2.5-fold without change in subcellular targeting. skα2(-/-) mice are apparently normal under basal conditions but show significantly reduced exercise capacity when challenged to run. Their skeletal muscles produce less force, are unable to increase force to match demand, and show significantly increased susceptibility to fatigue. The impairments affect both fast and slow muscle types. The subcellular targeting of α2 to the transverse tubules is important for this role. Increasing Na,K-ATPase α1 content cannot fully compensate for the loss of α2. The increased fatigability of skα2(-/-) muscles is reproduced in control extensor digitorum longus muscles by selectively inhibiting α2 enzyme activity with ouabain. These results demonstrate that the Na,K-ATPase α2 isoform performs an acute, isoform-specific role in skeletal muscle. Its activity is regulated by muscle use and enables working muscles to maintain contraction and resist fatigue.
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Affiliation(s)
- Tatiana L Radzyukevich
- Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0576 USA
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215
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Pinniger GJ, Lavin T, Bakker AJ. Skeletal muscle weakness caused by carrageenan-induced inflammation. Muscle Nerve 2012; 46:413-20. [PMID: 22907233 DOI: 10.1002/mus.23318] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION The skeletal muscle weakness associated with many chronic diseases has been attributed to the catabolic effect of pro-inflammatory cytokines. We aimed to determine if local muscle inflammation has direct affects on contractile function and contributes to muscle weakness independent of muscle atrophy or mechanical injury. METHODS Local muscle inflammation was induced by injecting an algal-derived polysaccharide, carrageenan (10 mg/kg), into the right tibialis anterior muscle in healthy ARC mice. The contralateral muscle was injected with sterile isotonic saline, and the muscles were removed after 24 h for measurement of contractile function and cytokine concentration. RESULTS Carrageenan significantly reduced maximum specific force, decreased the maximum rate of force development, altered the force-frequency relationship, and increased intramuscular levels of pro-inflammatory cytokines and chemokines. CONCLUSIONS These results indicate that carrageenan directly affects contractile function and causes skeletal muscle weakness. Local muscle inflammation may contribute to the weakness observed in inflammatory related disorders.
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Affiliation(s)
- Gavin J Pinniger
- School of Biomedical, Biomolecular and Chemical Sciences, The University of Western Australia, Crawley, Western Australia, 6009 Australia.
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216
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Mathewson MA, Chapman MA, Hentzen ER, Fridén J, Lieber RL. Anatomical, architectural, and biochemical diversity of the murine forelimb muscles. J Anat 2012; 221:443-51. [PMID: 22938020 DOI: 10.1111/j.1469-7580.2012.01559.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2012] [Indexed: 11/29/2022] Open
Abstract
We characterized the architecture, fiber type, titin isoform distribution, and collagen content of 27 portions of 22 muscles in the murine forelimb. The mouse forelimb was different from the human arm in that it had the extensor digitorum lateralis muscle and no brachioradialis muscle. Architecturally, the mouse forelimb differed from humans with regard to load bearing, having a much larger contribution from extensors than flexors. In mice, the extensor : flexor PCSA ratio is 2.7, whereas in humans it is only 1.4. When the architectural difference index was calculated, similarities became especially apparent between flexors and extensors of the distal forelimb, as well as pronators. Discriminant analysis revealed that biochemical measures of collagen, titin, and myosin heavy chain were all strong between-species discriminators. In terms of composition, when compared with similar muscles in humans, mice had, on average, faster muscles with higher collagen content and larger titin isoforms. This report establishes the anatomical and biochemical properties of mouse forelimb muscles. Given the prevalence of this species in biological studies, these data will be invaluable for studying the biological basis of mouse muscle structure and function.
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Affiliation(s)
- Margie A Mathewson
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA
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217
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Relationship between muscle architecture and joint performance during concentric contractions in humans. J Appl Biomech 2012; 29:405-12. [PMID: 22927507 DOI: 10.1123/jab.29.4.405] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to examine the relationship between muscle architecture of the triceps brachii (TB) and joint performance during concentric elbow extensions. Twenty-two men performed maximal isometric and concentric elbow extensions against various loads. Joint torque and angular velocity during concentric contractions were measured, and joint power was calculated. Muscle length, cross-sectional areas, and volume of TB were measured from magnetic resonance images. Pennation angle (PA) of TB at rest was determined by ultrasonography. The PA was significantly correlated with the maximal isometric torque (r = .471), but not to the torque normalized by muscle volume (r = .312). A significant correlation was found between PA and the angular velocity at 0 kg load (r = .563), even when the angular velocity was normalized by the muscle length (r = .536). The PA was significantly correlated with the maximal joint power (r = .519), but not with the power normalized by muscle volume (r = .393). These results suggest that PA has a positive influence on the muscle shortening velocity during an unloaded movement, but does not have a significant influence on the maximum power generation in untrained men.
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218
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Oishi M, Ogihara N, Endo H, Une Y, Ichihara N, Asari M, Amasaki H. Muscle dimensions of the foot in the orangutan and the chimpanzee. J Anat 2012; 221:311-7. [PMID: 22803586 DOI: 10.1111/j.1469-7580.2012.01545.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2012] [Indexed: 11/28/2022] Open
Abstract
The hindlimbs of two orangutans and four chimpanzees were dissected, and muscle parameters (mass, fascicle length, and physiological cross-sectional area: PCSA) were determined to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire foot muscles for normalization. The results indicate that the pedal interosseous and the intrinsic pedal digital extensor muscles in the orangutans probably have higher capacity for force production due to their relatively larger PCSAs than in chimpanzees. Moreover, the medial components of the intrinsic muscles exhibited relatively larger mass and PCSA ratios in orangutans. The mass and PCSA ratios of the hallucal muscles were larger in chimpanzees. These differences in foot muscle dimensions of the two species suggest that the orangutan is more specialized for hook-like digital gripping without involvement of the rudimentary hallux, while the chimpanzee is adapted to hallux-assisted power gripping in arboreal locomotion.
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Affiliation(s)
- Motoharu Oishi
- Department of Veterinary Anatomy, School of Veterinary Medicine, Nippon Veterinary and Life Science University, Tokyo, Japan.
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219
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Manzano R, Toivonen JM, Calvo AC, Oliván S, Zaragoza P, Rodellar C, Montarras D, Osta R. Altered in vitro proliferation of mouse SOD1-G93A skeletal muscle satellite cells. NEURODEGENER DIS 2012; 11:153-64. [PMID: 22797053 DOI: 10.1159/000338061] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 03/11/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS) is the most common adult-onset neurodegenerative disease characterized by ascending muscle weakness, atrophy and paralysis. Early muscle abnormalities that precede motor neuron loss in ALS may destabilize neuromuscular junctions, and we have previously demonstrated alterations in myogenic regulatory factor (MRF) expression in vivo and in the activation of myofiber-associated skeletal muscle satellite cells (SMSCs) in the mouse model of ALS (SOD1-G93A). METHODS To elucidate niche dependence versus cell-autonomous mutant SOD1 (mSOD1) toxicity in this model, we measured in vitro proliferation potential and MRF and cyclin gene expression in SMSC cultures derived from fast-twitch extensor digitorum longus and slow-twitch soleus muscles of SOD1-G93A mice. RESULTS SMSCs from early presymptomatic (p40) to terminal, semi-paralytic (p120) SOD1-G93A mice demonstrated generally lower proliferation potential compared with age-matched controls. However, induced proliferation was observed in surgically denervated wild-type animals and SOD1-G93A animals at p90, when critical denervation arises. SMSCs from fast and slow muscles were similarly affected by mSOD1 expression. Lowered proliferation rate was generally corroborated with decreased relative MRF expression levels, although this was most prominent in early age and was modulated by muscle type origin. Cyclins controlling cell proliferation did not show modifications in their mRNA levels; however, the expression of cyclin-dependent kinase inhibitor 1A (Cdkn1a), which is known to promote myoblast differentiation, was decreased in SOD1-G93A cultures. CONCLUSIONS Our data suggest that the function of SMSCs is impaired in SOD1-G93A satellite cells from the earliest stages of the disease when no critical motor neuron loss has been described.
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Affiliation(s)
- Raquel Manzano
- LAGENBIO-I3A, Aragon's Institute of Health Sciences, University of Zaragoza, Zaragoza, Spain
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220
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Carrasco DI, Bichler EK, Rich MM, Wang X, Seburn KL, Pinter MJ. Motor terminal degeneration unaffected by activity changes in SOD1(G93A) mice; a possible role for glycolysis. Neurobiol Dis 2012; 48:132-40. [PMID: 22750521 DOI: 10.1016/j.nbd.2012.06.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/06/2012] [Accepted: 06/22/2012] [Indexed: 12/13/2022] Open
Abstract
This study examined whether activity is a contributing factor to motor terminal degeneration in mice that overexpress the G93A mutation of the SOD1 enzyme found in humans with inherited motor neuron disease. Previously, we showed that overload of muscles accomplished by synergist denervation accelerated motor terminal degeneration in dogs with hereditary canine spinal muscular atrophy (HCSMA). In the present study, we found that SOD1 plantaris muscles overloaded for 2months showed no differences of neuromuscular junction innervation status when compared with normally loaded, contralateral plantaris muscles. Complete elimination of motor terminal activity using blockade of sciatic nerve conduction with tetrodotoxin cuffs for 1month also produced no change of plantaris innervation status. To assess possible effects of activity on motor terminal function, we examined the synaptic properties of SOD1 soleus neuromuscular junctions at a time when significant denervation of close synergists had occurred as a result of natural disease progression. When examined in glucose media, SOD1 soleus synaptic properties were similar to wildtype. When glycolysis was inhibited and ATP production limited to mitochondria, however, blocking of evoked synaptic transmission occurred and a large increase in the frequency of spontaneous mEPCs was observed. Similar effects were observed at neuromuscular junctions in muscle from dogs with inherited motor neuron disease (HCSMA), although significant defects of synaptic transmission exist at these neuromuscular junctions when examined in glucose media, as reported previously. These results suggest that glycolysis compensates for mitochondrial dysfunction at motor terminals of SOD1 mice and HCSMA dogs. This compensatory mechanism may help to support resting and activity-related metabolism in the presence of dysfunctional mitochondria and prolong the survival of SOD1 motor terminals.
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Affiliation(s)
- Dario I Carrasco
- Department of Physiology, Emory University, Atlanta, GA 30322, USA
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221
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Manzano R, Toivonen JM, Calvo AC, Oliván S, Zaragoza P, Muñoz MJ, Montarras D, Osta R. Quantity and activation of myofiber-associated satellite cells in a mouse model of amyotrophic lateral sclerosis. Stem Cell Rev Rep 2012; 8:279-87. [PMID: 21537993 DOI: 10.1007/s12015-011-9268-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Raquel Manzano
- LAGENBIO-I3A, Instituto Aragonés de Ciencias de la Salud (IACS), Universidad de Zaragoza, Miguel Servet 177, 50013, Zaragoza, Spain
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222
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Weber H, Rauch A, Adamski S, Chakravarthy K, Kulkarni A, Dogdas B, Bendtsen C, Kath G, Alves SE, Wilkinson HA, Chiu CS. Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models. J Appl Physiol (1985) 2012; 112:2087-98. [PMID: 22461442 DOI: 10.1152/japplphysiol.00871.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia.
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Affiliation(s)
- H. Weber
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - A. Rauch
- Bioelectronics, Merck Research Laboratories, West Point, Pennsylvania
| | - S. Adamski
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - K. Chakravarthy
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - A. Kulkarni
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - B. Dogdas
- Informatics IT, Merck Research Laboratories, West Point, Pennsylvania
| | - C. Bendtsen
- Merck Research Laboratories, IRBM, Rome, Italy; and
| | - G. Kath
- Bioelectronics, Merck Research Laboratories, Rahway, New Jersey
| | - S. E. Alves
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - H. A. Wilkinson
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
| | - C-S. Chiu
- Musculo-Skeletal Biology Program Team, Merck Research Laboratories, West Point, Pennsylvania
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223
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Murphy KT, Ham DJ, Church JE, Naim T, Trieu J, Williams DA, Lynch GS. Parvalbumin gene transfer impairs skeletal muscle contractility in old mice. Hum Gene Ther 2012; 23:824-36. [PMID: 22455364 DOI: 10.1089/hum.2011.210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Sarcopenia is the progressive age-related loss of skeletal muscle mass associated with functional impairments that reduce mobility and quality of life. Overt muscle wasting with sarcopenia is usually preceded by a slowing of the rate of relaxation and a reduction in maximum force production. Parvalbumin (PV) is a cytosolic Ca(2+) buffer thought to facilitate relaxation in muscle. We tested the hypothesis that restoration of PV levels in muscles of old mice would increase the magnitude and hasten relaxation of submaximal and maximal force responses. The tibialis anterior (TA) muscles of young (6 month), adult (13 month), and old (26 month) C57BL/6 mice received electroporation-assisted gene transfer of plasmid encoding PV or empty plasmid (pcDNA3.1). Contractile properties of TA muscles were assessed in situ 14 days after transfer. In old mice, muscles with increased PV expression had a 40% slower rate of tetanic force development (p<0.01), and maximum twitch and tetanic force were 22% and 16% lower than control values, respectively (p<0.05). Muscles with increased PV expression from old mice had an 18% lower maximum specific (normalized) force than controls, and absolute force was `26% lower at higher stimulation frequencies (150-300 Hz, p<0.05). In contrast, there was no effect of increased PV expression on TA muscle contractile properties in young and adult mice. The impairments in skeletal muscle function in old mice argue against PV overexpression as a therapeutic strategy for ameliorating aspects of contractile dysfunction with sarcopenia and help clarify directions for therapeutic interventions for age-related changes in skeletal muscle structure and function.
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Affiliation(s)
- Kate T Murphy
- Basic and Clinical Myology Laboratory, The University of Melbourne, Melbourne, VIC 3010, Australia
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224
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Pratt SJ, Lawlor MW, Shah SB, Lovering RM. An in vivo rodent model of contraction-induced injury in the quadriceps muscle. Injury 2012; 43:788-93. [PMID: 22001505 PMCID: PMC3310278 DOI: 10.1016/j.injury.2011.09.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/08/2011] [Accepted: 09/12/2011] [Indexed: 02/02/2023]
Abstract
Most animal studies of muscle contractile function utilise the anterior or posterior crural muscle (dorsiflexors and plantarflexors, respectively). An advantage to using these muscles is that the common fibular and tibial nerves are readily accessible, while the small size of the crural muscles is a disadvantage. Working with small muscles not only makes some in vivo imaging and the muscle testing techniques more challenging, but also provides limited amounts of tissue to study. The purpose of this study was to describe a new animal muscle injury model in the quadriceps that results in a significant and reproducible loss of force. The thigh of Sprague Dawley rats (N=5) and C57BL/10 mice (N=5) was immobilised and the ankle was attached to a custom-made lever arm. The femoral nerve was stimulated using subcutaneous electrodes and injury was induced using 50 lengthening ("eccentric") contractions through a 70° arc of knee motion. This protocol produces a significant and reproducible injury, with comparable susceptibility to injury in the rats and mice. This novel model shows that the quadriceps muscle provides a means to study whole muscle contractility, injury, and recovery in vivo. In addition to the usual benefits of an in vivo model, the larger size of the quadriceps facilitates in vivo imaging and provides a significant increase in the amount of tissue available for histology and biochemistry studies. A controlled muscle injury in the quadriceps also allows one to study a muscle, with mixed fibre types, which is extremely relevant to gait in humans and quadruped models.
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Affiliation(s)
- Stephen J.P. Pratt
- University of Maryland School of Medicine, Department of Orthopaedics, Baltimore, Maryland
| | - Michael W. Lawlor
- Division of Genetics and Program in Genomics, The Manton Center for Orphan Disease Research, Children’s Hospital Boston, Harvard Medical School, Boston, Massachusetts
| | - Sameer B. Shah
- University of Maryland, Fischell Department of Bioengineering, College Park, Maryland
| | - Richard M. Lovering
- University of Maryland School of Medicine, Department of Orthopaedics, Baltimore, Maryland
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225
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Graziotti GH, Chamizo VE, Ríos C, Acevedo LM, Rodríguez-Menéndez JM, Victorica C, Rivero JLL. Adaptive functional specialisation of architectural design and fibre type characteristics in agonist shoulder flexor muscles of the llama, Lama glama. J Anat 2012; 221:151-63. [PMID: 22625659 DOI: 10.1111/j.1469-7580.2012.01520.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Like other camelids, llamas (Lama glama) have the natural ability to pace (moving ipsilateral limbs in near synchronicity). But unlike the Old World camelids (bactrian and dromedary camels), they are well adapted for pacing at slower or moderate speeds in high-altitude habitats, having been described as good climbers and used as pack animals for centuries. In order to gain insight into skeletal muscle design and to ascertain its relationship with the llama's characteristic locomotor behaviour, this study examined the correspondence between architecture and fibre types in two agonist muscles involved in shoulder flexion (M. teres major - TM and M. deltoideus, pars scapularis - DS and pars acromialis - DA). Architectural properties were found to be correlated with fibre-type characteristics both in DS (long fibres, low pinnation angle, fast-glycolytic fibre phenotype with abundant IIB fibres, small fibre size, reduced number of capillaries per fibre and low oxidative capacity) and in DA (short fibres, high pinnation angle, slow-oxidative fibre phenotype with numerous type I fibres, very sparse IIB fibres, and larger fibre size, abundant capillaries and high oxidative capacity). This correlation suggests a clear division of labour within the M. deltoideus of the llama, DS being involved in rapid flexion of the shoulder joint during the swing phase of the gait, and DA in joint stabilisation during the stance phase. However, the architectural design of the TM muscle (longer fibres and lower fibre pinnation angle) was not strictly matched with its fibre-type characteristics (very similar to those of the postural DA muscle). This unusual design suggests a dual function of the TM muscle both in active flexion of the shoulder and in passive support of the limb during the stance phase, pulling the forelimb to the trunk. This functional specialisation seems to be well suited to a quadruped species that needs to increase ipsilateral stability of the limb during the support phase of the pacing gait. Compared with other species, llama skeletal muscles are well suited for greater force generation combined with higher fatigue resistance during exercise. These characteristics are interpreted as being of high adaptive value, given the llama's habitat and its use as a pack animal.
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Affiliation(s)
- Guillermo H Graziotti
- Departament of Veterinary Anatomy, Faculty of Veterinary Sciences, University of Buenos Aires, Buenos Aires, Argentina
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226
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Lin KF, Sun HH, Macewan MR, Mackinnon SE, Johnson PJ. GDNF overexpression fails to provoke muscle recovery from botulinum toxin poisoning: a preliminary study. Microsurgery 2012; 32:370-6. [PMID: 22473739 DOI: 10.1002/micr.21967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 11/11/2022]
Abstract
Glial cell line-derived neurotrophic factor (GDNF) has potent axonal growth and survival effects on motoneurons. This study used transgenic Myo-GDNF mice to assess the effects of targeted GDNF overexpression on functional recovery after botulinum toxin type A (BTxA) chemodenervation. BTxA (0.1 U) was injected into the tibialis anterior (TA) muscle of wild-type CF1 and transgenic Myo-GDNF mice. On days 1, 7, 14, and 21 after injection, evoked muscle force production and muscle mass were measured (n = 6, for each group at each time point). Greater maximal tetanic force and calculated specific force were evoked in Myo-GDNF animals when compared with control CF1 animals at days 1, 7, and 21. However, the differences were not statistically significant. Similarly, modest reductions in muscle atrophy in the Myo-GDNF group at all time points were not statistically significant. Targeted overexpression of GDNF in the muscles of Myo-GDNF mice did not improve motor recovery in the first 21 days after BTxA chemodenervation.
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Affiliation(s)
- Kenny F Lin
- Division of Plastic and Reconstructive Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA
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227
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Meyer GA, Lieber RL. Skeletal muscle fibrosis develops in response to desmin deletion. Am J Physiol Cell Physiol 2012; 302:C1609-20. [PMID: 22442138 DOI: 10.1152/ajpcell.00441.2011] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Skeletal muscle is a dynamic composite of proteins that responds to both internal and external cues to facilitate muscle adaptation. In cases of disease or altered use, these messages can be distorted resulting in myopathic conditions such as fibrosis. In this work, we describe a mild and progressive fibrotic adaptation in skeletal muscle lacking the cytoskeletal intermediate filament protein desmin. Muscles lacking desmin become progressively stiffer, accumulate increased collagen, and increase expression of genes involved in extracellular matrix turnover. Additionally, in the absence of desmin, skeletal muscle is in an increased state of inflammation and regeneration as indicated by increased centrally nucleated fibers, elevated inflammation and regeneration related gene expression, and increased numbers of inflammatory cells. These data suggest a potential link between increased cellular damage and the development of fibrosis in muscles lacking the cytoskeletal support of the desmin filament network.
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Affiliation(s)
- Gretchen A Meyer
- Department of Bioengineering, University of California, San Diego, USA
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228
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Nishikawa S, Hosokawa M, Miyashita K. Fucoxanthin promotes translocation and induction of glucose transporter 4 in skeletal muscles of diabetic/obese KK-A(y) mice. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2012; 19:389-94. [PMID: 22305278 DOI: 10.1016/j.phymed.2011.11.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 10/05/2011] [Accepted: 11/02/2011] [Indexed: 05/31/2023]
Abstract
Fucoxanthin (Fx) isolated from Undaria pinnatifida suppresses the development of hyperglycemia and hyperinsulinemia of diabetic/obese KK-A(y) mice after 2 weeks of feeding 0.2% Fx-containing diet. In the soleus muscle of KK-A(y) mice that were fed Fx, glucose transporter 4 (GLUT4) translocation to plasma membranes from cytosol was promoted. On the other hand, Fx increased GLUT4 expression levels in the extensor digitorum longus (EDL) muscle, although GLUT4 translocation tended to increase. The expression levels of insulin receptor (IR) mRNA and phosphorylation of Akt, which are in upstream of the insulin signaling pathway regulating GLUT4 translocation, were also enhanced in the soleus and EDL muscles of the mice fed Fx. Furthermore, Fx induced peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α), which has been reported to increase GLUT4 expression, in both soleus and EDL muscles. These results suggest that in diabetic/obese KK-A(y) mice, Fx improves hyperglycemia by activating the insulin signaling pathway, including GLUT4 translocation, and inducing GLUT4 expression in the soleus and EDL muscles, respectively, of diabetic/obese KK-A(y) mice.
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Affiliation(s)
- Sho Nishikawa
- Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato Hakodate, Hokkaido 041-8611, Japan
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229
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Ottenheijm CAC, Granzier H, Labeit S. The sarcomeric protein nebulin: another multifunctional giant in charge of muscle strength optimization. Front Physiol 2012; 3:37. [PMID: 22375125 PMCID: PMC3286824 DOI: 10.3389/fphys.2012.00037] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 02/09/2012] [Indexed: 12/01/2022] Open
Abstract
The sliding filament model of the sarcomere was developed more than half a century ago. This model, consisting only of thin and thick filaments, has been successful in explaining many, but not all, features of skeletal muscle. Work during the 1980s revealed the existence of two additional filaments: the giant filamentous proteins titin and nebulin. Whereas the role of titin rapidly progressed, nebulin’s role in muscle structure and function remained long nebulous. An important feature of muscle structure and function that has remained relatively obscure concerns the mechanisms that are involved in regulating thin filament length. Filament length is an important aspect of muscle function as force production is proportional to the amount of overlap between thick and thin filaments. Recent advances, due in part to the generation of nebulin KO models, reveal that nebulin plays an important role in the regulation of thin filament length, most likely by stabilizing F-actin assemblies. Another structural feature of skeletal muscle that has been incompletely understood concerns the mechanisms involved in maintaining Z-disk structure and the regular lateral alignment of adjacent sarcomeres during contraction. Recent studies indicate that nebulin is part of a protein complex that mechanically links adjacent myofibrils. In addition to these structural roles in support of myofibrillar force generation, nebulin has been also shown to regulate directly muscle contraction at the level of individual crossbridges: cycling kinetics and the calcium sensitivity of force producing crossbridges is enhanced in the presence of nebulin. Thus, these recent data all point to nebulin being important for muscle force optimization. Consequently, muscle weakness as the lead symptom develops in the case of patients with nemaline myopathy that have mutations in the nebulin gene. Here, we discuss these important novel insights into the role of nebulin in skeletal muscle function.
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Affiliation(s)
- Coen A C Ottenheijm
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center Amsterdam, Netherlands
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230
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Froeling M, Nederveen AJ, Heijtel DF, Lataster A, Bos C, Nicolay K, Maas M, Drost MR, Strijkers GJ. Diffusion-tensor MRI reveals the complex muscle architecture of the human forearm. J Magn Reson Imaging 2012; 36:237-48. [DOI: 10.1002/jmri.23608] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 01/11/2012] [Indexed: 11/06/2022] Open
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Alvarez GI, Díaz AO, Longo MV, Becerra F, Vassallo AI. Histochemical and Morphometric Analyses of the Musculature of the Forelimb of the Subterranean Rodent Ctenomys talarum (Octodontoidea). Anat Histol Embryol 2012; 41:317-25. [DOI: 10.1111/j.1439-0264.2012.01137.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 01/01/2012] [Indexed: 11/26/2022]
Affiliation(s)
- G. I. Alvarez
- Departamento de Biología; Instituto de Investigaciones Marinas y Costeras, FCEyN, CONICET; Universidad Nacional de Mar del Plata; Provincia de Buenos Aires; Argentina
| | - A. O. Díaz
- Departamento de Biología; Instituto de Investigaciones Marinas y Costeras, FCEyN, CONICET; Universidad Nacional de Mar del Plata; Provincia de Buenos Aires; Argentina
| | - M. V. Longo
- Departamento de Biología; Instituto de Investigaciones Marinas y Costeras, FCEyN, CONICET; Universidad Nacional de Mar del Plata; Provincia de Buenos Aires; Argentina
| | - F. Becerra
- Departamento de Biología; Instituto de Investigaciones Marinas y Costeras, FCEyN, CONICET; Universidad Nacional de Mar del Plata; Provincia de Buenos Aires; Argentina
| | - A. I. Vassallo
- Departamento de Biología; Instituto de Investigaciones Marinas y Costeras, FCEyN, CONICET; Universidad Nacional de Mar del Plata; Provincia de Buenos Aires; Argentina
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232
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Abstract
Skeletal muscle is a highly adaptive tissue that modifies its size in response to a variety of external stimuli. In adult mammals, skeletal muscle hypertrophy occurs primarily as a response to increases in external loading. Here, we describe the methods that should be used for a comprehensive assessment of muscle hypertrophy in animal models. The methods include the measurement of muscle mass, fiber cross-sectional area, contractile function, and protein concentration.
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233
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Matsumura CY, Taniguti APT, Pertille A, Neto HS, Marques MJ. Stretch-activated calcium channel protein TRPC1 is correlated with the different degrees of the dystrophic phenotype in mdx mice. Am J Physiol Cell Physiol 2011; 301:C1344-50. [DOI: 10.1152/ajpcell.00056.2011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In Duchenne muscular dystrophy (DMD) and in the mdx mouse model of DMD, the lack of dystrophin is related to enhanced calcium influx and muscle degeneration. Stretch-activated channels (SACs) might be directly involved in the pathology of DMD, and transient receptor potential cation channels have been proposed as likely candidates of SACs. We investigated the levels of transient receptor potential canonical channel 1 (TRPC1) and the effects of streptomycin, a SAC blocker, in muscles showing different degrees of the dystrophic phenotype. Mdx mice (18 days old, n = 16) received daily intraperitoneal injections of streptomycin (182 mg/kg body wt) for 18 days, followed by removal of the diaphragm, sternomastoid (STN), biceps brachii, and tibialis anterior muscles. Control mdx mice ( n = 37) were injected with saline. Western blot analysis showed higher levels of TRPC1 in diaphragm muscle compared with STN and limb muscles. Streptomycin reduced creatine kinase and prevented exercise-induced increases of total calcium and Evans blue dye uptake in diaphragm and in STN muscles. It is suggested that different levels of the stretch-activated calcium channel protein TRPC1 may contribute to the different degrees of the dystrophic phenotype seen in mdx mice. Early treatment designed to regulate the activity of these channels may ameliorate the progression of dystrophy in the most affected muscle, the diaphragm.
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Affiliation(s)
- Cíntia Yuri Matsumura
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Ana Paula Tiemi Taniguti
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Adriana Pertille
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Humberto Santo Neto
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Maria Julia Marques
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
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234
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Larkin LM, Davis CS, Sims-Robinson C, Kostrominova TY, Van Remmen H, Richardson A, Feldman EL, Brooks SV. Skeletal muscle weakness due to deficiency of CuZn-superoxide dismutase is associated with loss of functional innervation. Am J Physiol Regul Integr Comp Physiol 2011; 301:R1400-7. [PMID: 21900648 DOI: 10.1152/ajpregu.00093.2011] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An association between oxidative stress and muscle atrophy and weakness in vivo is supported by elevated oxidative damage and accelerated loss of muscle mass and force with aging in CuZn-superoxide dismutase-deficient (Sod1(-/-)) mice. The purpose was to determine the basis for low specific force (N/cm(2)) of gastrocnemius muscles in Sod1(-/-) mice and establish the extent to which structural and functional changes in muscles of Sod1(-/-) mice resemble those associated with normal aging. We tested the hypothesis that muscle weakness in Sod1(-/-) mice is due to functionally denervated fibers by comparing forces during nerve and direct muscle stimulation. No differences were observed for wild-type mice at any age in the forces generated in response to nerve and muscle stimulation. Nerve- and muscle-stimulated forces were also not different for 4-wk-old Sod1(-/-) mice, whereas, for 8- and 20-mo-old mice, forces during muscle stimulation were 16 and 30% greater, respectively, than those obtained using nerve stimulation. In addition to functional evidence of denervation with aging, fiber number was not different for Sod1(-/-) and wild-type mice at 4 wk, but 50% lower for Sod1(-/-) mice by 20 mo, and denervated motor end plates were prevalent in Sod1(-/-) mice at both 8 and 20 mo and in WT mice by 28 mo. The data suggest ongoing denervation in muscles of Sod1(-/-) mice that results in fiber loss and muscle atrophy. Moreover, the findings support using Sod1(-/-) mice to explore mechanistic links between oxidative stress and the progression of deficits in muscle structure and function.
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Affiliation(s)
- Lisa M Larkin
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2200, USA
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235
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Ota S, Uehara K, Nozaki M, Kobayashi T, Terada S, Tobita K, Fu FH, Huard J. Intramuscular transplantation of muscle-derived stem cells accelerates skeletal muscle healing after contusion injury via enhancement of angiogenesis. Am J Sports Med 2011; 39:1912-22. [PMID: 21828363 DOI: 10.1177/0363546511415239] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Muscle contusions are common muscle injuries. Although these injuries are capable of healing, incomplete functional recovery often occurs. Muscle-derived stem cells (MDSCs) are likely derived from blood vessel cells and have a multilineage differentiation potential. PURPOSE The aims of this study are (1) to find optimal timing of MDSC transplantation to enhance muscle healing by stimulating muscle regeneration and preventing scar tissue (fibrosis) formation after skeletal muscle contusion injury, and (2) to investigate the role of angiogenesis in the muscle-healing process after MDSC transplantation. STUDY DESIGN Controlled laboratory study. METHODS Muscle-derived stem cells were injected directly into injured tibialis anterior muscles of mice at various time points (1, 4, and 7 days) after the muscle contusion injury. Muscle regeneration, angiogenesis, and fibrosis formation were evaluated by histology and real-time polymerase chain reaction analysis, and functional recovery was measured by physiologic testing. RESULTS Transplantation of MDSCs at 4 days after injury significantly promoted angiogenesis, which was induced by high levels of vascular endothelial growth factor expression at week 1, and significantly increased muscle regeneration and muscle strength by week 2, when compared with the other groups. A decrease in fibrosis formation was observed at week 4, when compared with the other groups, after the transplantation of MDSCs at 4 and 7 days after injury. CONCLUSION Intramuscular injection of MDSCs at 4 days after injury improved and accelerated skeletal muscle healing by increasing angiogenesis and decreasing scar tissue formation. CLINICAL RELEVANCE These findings could contribute to the development of biologic treatments to aid in muscle healing after muscle injury.
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Affiliation(s)
- Shusuke Ota
- Stem Cell Research Center, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
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236
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Lieber RL, Ward SR. Skeletal muscle design to meet functional demands. Philos Trans R Soc Lond B Biol Sci 2011; 366:1466-76. [PMID: 21502118 DOI: 10.1098/rstb.2010.0316] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Skeletal muscles are length- and velocity-sensitive force producers, constructed of a vast array of sarcomeres. Muscles come in a variety of sizes and shapes to accomplish a wide variety of tasks. How does muscle design match task performance? In this review, we outline muscle's basic properties and strategies that are used to produce movement. Several examples are provided, primarily for human muscles, in which skeletal muscle architecture and moment arms are tailored to a particular performance requirement. In addition, the concept that muscles may have a preferred sarcomere length operating range is also introduced. Taken together, the case is made that muscles can be fine-tuned to perform specific tasks that require actuators with a wide range of properties.
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Affiliation(s)
- Richard L Lieber
- Department of Orthopaedic Surgery, University of California San Diego, San Diego, CA 92121, USA.
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237
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Hanna JB, Schmitt D. Comparative triceps surae morphology in primates: a review. ANATOMY RESEARCH INTERNATIONAL 2011; 2011:191509. [PMID: 22567288 PMCID: PMC3335445 DOI: 10.1155/2011/191509] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Accepted: 04/28/2011] [Indexed: 11/18/2022]
Abstract
Primate locomotor evolution, particularly the evolution of bipedalism, is often examined through morphological studies. Many of these studies have examined the uniqueness of the primate forelimb, and others have examined the primate hip and thigh. Few data exist, however, regarding the myology and function of the leg muscles, even though the ankle plantar flexors are highly important during human bipedalism. In this paper, we draw together data on the fiber type and muscle mass variation in the ankle plantar flexors of primates and make comparisons to other mammals. The data suggest that great apes, atelines, and lorisines exhibit similarity in the mass distribution of the triceps surae. We conclude that variation in triceps surae may be related to the shared locomotor mode exhibited by these groups and that triceps surae morphology, which approaches that of humans, may be related to frequent use of semiplantigrade locomotion and vertical climbing.
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Affiliation(s)
- Jandy B. Hanna
- Department of Biomedical Sciences, West Virginia School of Osteopathic Medicine, Lewisburg, WV 24901, USA
| | - Daniel Schmitt
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA
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238
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Wood LK, Arruda EM, Brooks SV. Regional stiffening with aging in tibialis anterior tendons of mice occurs independent of changes in collagen fibril morphology. J Appl Physiol (1985) 2011; 111:999-1006. [PMID: 21737825 DOI: 10.1152/japplphysiol.00460.2011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The incidence of tendon degeneration and rupture increases with advancing age. The mechanisms underlying this increased risk remain unknown but may arise because of age-related changes in tendon mechanical properties and structure. Our purpose was to determine the effect of aging on tendon mechanical properties and collagen fibril morphology. Regional mechanical properties and collagen fibril characteristics were determined along the length of tibialis anterior (TA) tendons from adult (8- to 12-mo-old) and old (28- to 30-mo-old) mice. Tangent modulus of all regions along the tendons increased in old age, but the increase was substantially greater in the proximal region adjacent to the muscle than in the rest of the tendon. Overall end-to-end modulus increased with old age at maximum tendon strain (799 ± 157 vs. 1,419 ± 91 MPa) and at physiologically relevant strain (377 ± 137 vs. 798 ± 104 MPa). Despite the dramatic changes in tendon mechanical properties from adulthood to old age, collagen fibril morphology and packing fraction remained relatively constant in all tendon regions examined. Since tendon properties are influenced by their external loading environment, we also examined the effect of aging on TA muscle contractile properties. Maximum isometric force did not differ between the age groups. We conclude that TA tendons stiffen in a region-dependent manner throughout the life span, but the changes in mechanical properties are not accompanied by corresponding changes in collagen fibril morphology or force-generating capacity of the TA muscle.
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Affiliation(s)
- Lauren K Wood
- Department of Biomedical Engineering, Univ. of Michigan, Ann Arbor, MI 48109-2200, USA
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239
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Sakuma J, Kanehisa H, Yanai T, Fukunaga T, Kawakami Y. Fascicle-tendon behavior of the gastrocnemius and soleus muscles during ankle bending exercise at different movement frequencies. Eur J Appl Physiol 2011; 112:887-98. [PMID: 21687997 DOI: 10.1007/s00421-011-2032-y] [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: 11/08/2010] [Accepted: 05/28/2011] [Indexed: 11/26/2022]
Abstract
The present study investigated the effect of movement frequencies on the behavior of fascicles and tendons of synergistic muscles. Seven male subjects performed ankle bending (calf-raise) exercises at four movement frequencies (1.33, 1.67, 1.84, and 2.00 Hz), performed with an identical range of ankle joint motion. The fascicle and tendon behavior of medial gastrocnemius (MG) and soleus (SOL) was measured by ultrasonography while kinematic and kinetic parameters of the ankle were recorded. The torque of ankle joint was larger at higher exercise frequencies. The length change of muscle decreased and that of tendon increased at higher frequencies both for MG and for SOL, with no significant inter-muscle differences in the relative changes of muscle or tendon lengths to that of MTU. Changes of pennation angles and electromyographic activities as a function of movement frequency were also comparable for MG and SOL. These results suggest that under a stretch-shortening cycle action, the muscle-tendon interaction is altered by the movement frequency toward greater use of tendon elastic energy to provide greater MTU power at a higher frequency. Results also suggest that the movement frequency dependence of fascicle and tendon behavior is comparable between MG and SOL.
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Affiliation(s)
- Jun Sakuma
- Faculty of Sport Sciences, Waseda University, 2-579-15, Mikajima, Tokorozawa, Saitama 359-1192, Japan
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240
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Matta T, Simão R, de Salles BF, Spineti J, Oliveira LF. Strength Training's Chronic Effects on Muscle Architecture Parameters of Different Arm Sites. J Strength Cond Res 2011; 25:1711-7. [PMID: 21602648 DOI: 10.1519/jsc.0b013e3181dba162] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Thiago Matta
- Rio de Janeiro Federal University, Physical Education Post-Graduation Program, Rio de Janeiro, Brazil
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241
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Lustgarten MS, Jang YC, Liu Y, Qi W, Qin Y, Dahia PL, Shi Y, Bhattacharya A, Muller FL, Shimizu T, Shirasawa T, Richardson A, Van Remmen H. MnSOD deficiency results in elevated oxidative stress and decreased mitochondrial function but does not lead to muscle atrophy during aging. Aging Cell 2011; 10:493-505. [PMID: 21385310 DOI: 10.1111/j.1474-9726.2011.00695.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In a previous study, we reported that a deficiency in MnSOD activity (approximately 80% reduction) targeted to type IIB skeletal muscle fibers was sufficient to elevate oxidative stress and to reduce muscle function in young adult mice (TnIFastCreSod2(fl/fl) mice). In this study, we used TnIFastCreSod2(fl/fl) mice to examine the effect of elevated oxidative stress on mitochondrial function and to test the hypothesis that elevated oxidative stress and decreased mitochondrial function over the lifespan of the TnIFastCreSod2(fl/fl) mice would be sufficient to accelerate muscle atrophy associated with aging. We found that mitochondrial function is reduced in both young and old TnIFastCreSod2(fl/fl) mice, when compared with control mice. Complex II activity is reduced by 47% in young and by approximately 90% in old TnIFastCreSod2(fl/fl) mice, and was found to be associated with reduced levels of the catalytic subunits for complex II, SDHA and SDHB. Complex II-linked mitochondrial respiration is reduced by approximately 70% in young TnIFastCreSod2(fl/fl) mice. Complex II-linked mitochondrial Adenosine-Tri-Phosphate (ATP) production is reduced by 39% in young and was found to be almost completely absent in old TnIFastCreSod2(fl/fl) mice. Furthermore, in old TnIFastCreSod2(fl/fl) mice, aconitase activity is almost completely abolished; mitochondrial superoxide release remains > 2-fold elevated; and oxidative damage (measured as F(2) - isoprostanes) is increased by 30% relative to age-matched controls. These data show that despite elevated skeletal muscle-specific mitochondrial oxidative stress, oxidative damage, and complex II-linked mitochondrial dysfunction, age-related muscle atrophy was not accelerated in old TnIFastCreSod2(fl/fl) mice, suggesting mitochondrial oxidative stress may not be causal for age-related muscle atrophy.
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Affiliation(s)
- Michael S Lustgarten
- Department of Physiology, University of Texas Health Science Center at San Antonio, USA
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242
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Lovering RM, Roche JA, Goodall MH, Clark BB, McMillan A. An in vivo rodent model of contraction-induced injury and non-invasive monitoring of recovery. J Vis Exp 2011:2782. [PMID: 21610671 DOI: 10.3791/2782] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Muscle strains are one of the most common complaints treated by physicians. A muscle injury is typically diagnosed from the patient history and physical exam alone, however the clinical presentation can vary greatly depending on the extent of injury, the patient's pain tolerance, etc. In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies. Biological markers, such as serum creatine kinase levels, are typically elevated with muscle injury, but their levels do not always correlate with the loss of force production. This is even true of histological findings from animals, which provide a "direct measure" of damage, but do not account for all the loss of function. Some have argued that the most comprehensive measure of the overall health of the muscle in contractile force. Because muscle injury is a random event that occurs under a variety of biomechanical conditions, it is difficult to study. Here, we describe an in vivo animal model to measure torque and to produce a reliable muscle injury. We also describe our model for measurement of force from an isolated muscle in situ. Furthermore, we describe our small animal MRI procedure.
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Affiliation(s)
- Richard M Lovering
- Department of Physiology, University of Maryland School of Medicine, MD, USA.
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243
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Earp JE, Kraemer WJ, Cormie P, Volek JS, Maresh CM, Joseph M, Newton RU. Influence of muscle-tendon unit structure on rate of force development during the squat, countermovement, and drop jumps. J Strength Cond Res 2011; 25:340-7. [PMID: 21322836 DOI: 10.1519/jsc.0b013e3182052d78] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous research has highlighted the importance of muscle and tendon structure to stretch shortening cycle performance. However, the relationships between muscle and tendon structure to performance are highly dependent on the speed and intensity of the movement. The purpose of this study was to determine if muscle and tendon structure is associated with the rate of force development (RFD) throughout static squat jump (SJ), countermovement jump (CMJ), and drop jump (DJ; 30-cm height). Twenty-five strength- and power-trained men participated in the study. Using ultrasonography, vastus lateralis (VL) and gastrocnemius (GAS) pennation (PEN) and fascicle length (FL), and Achilles tendon (AT) thickness and length were measured. Subjects then performed SJ, CMJ, and DJ, during which RFD was calculated over time 5 distinct time intervals. During CMJs, early RFD could be predicted between 0 and 10 milliseconds by both GAS-FL (r² = 0.213, β = 0.461) and AT-length (r² = 0.191, β = 20.438). Between 10 and 30 milliseconds GAS-FL was a significant predictor of CMJ-RFD (r² = 0.218, β = 0.476). During DJ, initial RFD (0-10 milliseconds) could be significantly predicted by GAS-FL (r² = 0.185, β = 20.434), VL-PEN (r² = 0.189, β = 0.435), and GAS-PEN (r² = 0.188, β = 0.434). These findings suggest that longer ATs may have increased elasticity, which can decrease initial RFD during CMJ; thus, their use in talent identification is not recommended. The GAS fascicle length had an intensity-dependent relationship with RFD, serving to positively predict RFD during early CMJs and an inverse predictor during early DJs. During DDJs, subjects with greater PEN were better able to redirected initial impact forces. Although both strength and plyometric training have been shown to increase FL, only heavy strength training has been shown to increase PEN. Thus, when a high eccentric load or multiple jumps are required, heavy strength training might be used to elicit muscular adaptations that are suited to fast force production during jumping.
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Affiliation(s)
- Jacob E Earp
- School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.
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244
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Csapo R, Alegre LM, Baron R. Time kinetics of acute changes in muscle architecture in response to resistance exercise. J Sci Med Sport 2011; 14:270-4. [DOI: 10.1016/j.jsams.2011.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 12/07/2010] [Accepted: 02/18/2011] [Indexed: 11/26/2022]
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245
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Raben N, Schreiner C, Baum R, Takikita S, Xu S, Xie T, Myerowitz R, Komatsu M, Van der Meulen JH, Nagaraju K, Ralston E, Plotz PH. Suppression of autophagy permits successful enzyme replacement therapy in a lysosomal storage disorder--murine Pompe disease. Autophagy 2011; 6:1078-89. [PMID: 20861693 DOI: 10.4161/auto.6.8.13378] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Autophagy, an intracellular system for delivering portions of cytoplasm and damaged organelles to lysosomes for degradation/recycling, plays a role in many physiological processes and is disturbed in many diseases. We recently provided evidence for the role of autophagy in Pompe disease, a lysosomal storage disorder in which acid alphaglucosidase, the enzyme involved in the breakdown of glycogen, is deficient or absent. Clinically the disease manifests as a cardiac and skeletal muscle myopathy. The current enzyme replacement therapy (ERT) clears lysosomal glycogen effectively from the heart but less so from skeletal muscle. In our Pompe model, the poor muscle response to therapy is associated with the presence of pools of autophagic debris. To clear the fibers of the autophagic debris, we have generated a Pompe model in which an autophagy gene, Atg7, is inactivated in muscle. Suppression of autophagy alone reduced the glycogen level by 50–60%. Following ERT, muscle glycogen was reduced to normal levels, an outcome not observed in Pompe mice with genetically intact autophagy. The suppression of autophagy, which has proven successful in the Pompe model, is a novel therapeutic approach that may be useful in other diseases with disturbed autophagy.
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Affiliation(s)
- Nina Raben
- Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, USA.
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246
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Russ DW, Grandy JS, Toma K, Ward CW. Ageing, but not yet senescent, rats exhibit reduced muscle quality and sarcoplasmic reticulum function. Acta Physiol (Oxf) 2011; 201:391-403. [PMID: 20874807 DOI: 10.1111/j.1748-1716.2010.02191.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM Reduced muscle force greater than expected from loss of muscle mass has been reported in ageing muscles. Impaired sarcoplasmic reticulum (SR) Ca(2+) release has been implicated as a possible mechanism, and attributed to several factors, including loss of ryanodine receptor (RYR) expression and protein binding. The aim of this study was to evaluate muscle quality and SR Ca(2+) release in ageing rats that were not so old that major atrophy had occurred. METHODS We collected in situ force data from the plantarflexor muscle group and muscle mass from the constituent muscles to determine muscle quality (force/mass) in adult (6-8 months) and ageing (24 months) rats (n=8/group). We evaluated SR Ca(2+) uptake and release, and determined expression of key proteins associated with Ca(2+) release [RYR and FK506 binding protein (FKBP)] and uptake (SERCA, parvalbumin, calsequestrin). RESULTS Plantarflexor force and muscle quality were reduced with ageing (approx. 28 and 34%, respectively), but atrophy was limited, and significant only in the medial gastrocnemius (approx. 15%). The fast phase of SR Ca(2+) release was reduced with ageing in both gastrocnemii, as was FKBP expression and FKBP-RYR binding, but RYR expression was not affected. Similar, but non-significant changes were present in the plantaris, but the soleus muscle generally showed no ageing-related changes. CONCLUSION These data suggest a possible role for impaired SR Ca(2+) release in ageing-related loss of muscle quality, although not through loss of RYR expression.
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Affiliation(s)
- D W Russ
- Laboratory for Integrative Muscle Biology, School of Physical Therapy, Ohio University, Athens, OH 45701, USA.
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247
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Manzano R, Toivonen JM, Oliván S, Calvo AC, Moreno-Igoa M, Muñoz MJ, Zaragoza P, García-Redondo A, Osta R. Altered Expression of Myogenic Regulatory Factors in the Mouse Model of Amyotrophic Lateral Sclerosis. NEURODEGENER DIS 2011; 8:386-96. [DOI: 10.1159/000324159] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 01/05/2011] [Indexed: 12/14/2022] Open
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248
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Chemello F, Bean C, Cancellara P, Laveder P, Reggiani C, Lanfranchi G. Microgenomic analysis in skeletal muscle: expression signatures of individual fast and slow myofibers. PLoS One 2011; 6:e16807. [PMID: 21364935 PMCID: PMC3043066 DOI: 10.1371/journal.pone.0016807] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/30/2010] [Indexed: 11/18/2022] Open
Abstract
Background Skeletal muscle is a complex, versatile tissue composed of a variety of functionally diverse fiber types. Although the biochemical, structural and functional properties of myofibers have been the subject of intense investigation for the last decades, understanding molecular processes regulating fiber type diversity is still complicated by the heterogeneity of cell types present in the whole muscle organ. Methodology/Principal Findings We have produced a first catalogue of genes expressed in mouse slow-oxidative (type 1) and fast-glycolytic (type 2B) fibers through transcriptome analysis at the single fiber level (microgenomics). Individual fibers were obtained from murine soleus and EDL muscles and initially classified by myosin heavy chain isoform content. Gene expression profiling on high density DNA oligonucleotide microarrays showed that both qualitative and quantitative improvements were achieved, compared to results with standard muscle homogenate. First, myofiber profiles were virtually free from non-muscle transcriptional activity. Second, thousands of muscle-specific genes were identified, leading to a better definition of gene signatures in the two fiber types as well as the detection of metabolic and signaling pathways that are differentially activated in specific fiber types. Several regulatory proteins showed preferential expression in slow myofibers. Discriminant analysis revealed novel genes that could be useful for fiber type functional classification. Conclusions/Significance As gene expression analyses at the single fiber level significantly increased the resolution power, this innovative approach would allow a better understanding of the adaptive transcriptomic transitions occurring in myofibers under physiological and pathological conditions.
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Affiliation(s)
- Francesco Chemello
- Department of Biology and CRIBI Biotechnology Center, University of Padova, Padova, Italy
| | - Camilla Bean
- Department of Biology and CRIBI Biotechnology Center, University of Padova, Padova, Italy
| | - Pasqua Cancellara
- Department of Anatomy and Physiology, University of Padova, Padova, Italy
| | - Paolo Laveder
- Department of Biology and CRIBI Biotechnology Center, University of Padova, Padova, Italy
| | - Carlo Reggiani
- Department of Anatomy and Physiology, University of Padova, Padova, Italy
| | - Gerolamo Lanfranchi
- Department of Biology and CRIBI Biotechnology Center, University of Padova, Padova, Italy
- * E-mail:
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Murphy KT, Cobani V, Ryall JG, Ibebunjo C, Lynch GS. Acute antibody-directed myostatin inhibition attenuates disuse muscle atrophy and weakness in mice. J Appl Physiol (1985) 2011; 110:1065-72. [PMID: 21270350 DOI: 10.1152/japplphysiol.01183.2010] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Counteracting the atrophy of skeletal muscle associated with disuse has significant implications for minimizing the wasting and weakness in plaster casting, joint immobilization, and other forms of limb unloading, with relevance to orthopedics, sports medicine, and plastic and reconstructive surgery. We tested the hypothesis that antibody-directed myostatin inhibition would attenuate the loss of muscle mass and functional capacity in mice during 14 or 21 days of unilateral hindlimb casting. Twelve-week-old C57BL/10 mice were subjected to unilateral hindlimb plaster casting or served as controls. Mice received subcutaneous injections of saline or a mouse chimera of anti-human myostatin antibody (PF-354, 10 mg/kg; n = 6-9) on days 0 and 7 and were tested for muscle function on day 14, or were treated on days 0, 7, and 14 and tested for muscle function on day 21. Hindlimb casting reduced muscle mass, fiber size, and function of isolated soleus and extensor digitorum longus (EDL) muscles (P < 0.05). PF-354 attenuated the loss of muscle mass, fiber size, and function with greater effects after 14 days than after 21 days of casting, when wasting and weakness had plateaued (P < 0.05). Antibody-directed myostatin inhibition therefore attenuated the atrophy and loss of functional capacity in muscles from mice subjected to unilateral hindlimb casting with reductions in muscle size and strength being most apparent during the first 14 days of disuse. These findings highlight the therapeutic potential of antibody-directed myostatin inhibition for disuse atrophy especially within the first 2 wk of disuse.
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Affiliation(s)
- Kate T Murphy
- Basic and Clinical Myology Laboratory, Dept. of Physiology, The Univ. of Melbourne, Victoria 3010, Australia.
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Ramaswamy KS, Palmer ML, van der Meulen JH, Renoux A, Kostrominova TY, Michele DE, Faulkner JA. Lateral transmission of force is impaired in skeletal muscles of dystrophic mice and very old rats. J Physiol 2011; 589:1195-208. [PMID: 21224224 DOI: 10.1113/jphysiol.2010.201921] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The dystrophin–glycoprotein complex (DGC) provides an essential link from the muscle fibre cytoskeleton to the extracellular matrix. In dystrophic humans and mdx mice, mutations in the dystrophin gene disrupt the structure of the DGC causing severe damage to muscle fibres. In frog muscles, transmission of force laterally from an activated fibre to the muscle surface occurs without attenuation, but lateral transmission of force has not been demonstrated in mammalian muscles. A unique ‘yoke' apparatus was developed that attached to the epimysium of muscles midway between the tendons and enabled the measurement of lateral force. We now report that in muscles of young wild-type (WT) mice and rats, compared over a wide range of longitudinal forces, forces transmitted laterally showed little or no decrement. In contrast, for muscles of mdx mice and very old rats, forces transmitted laterally were impaired severely. Muscles of both mdx mice and very old rats showed major reductions in the expression of dystrophin. We conclude that during contractions, forces developed by skeletal muscles of young WT mice and rats are transmitted laterally from fibre to fibre through the DGC without decrement. In contrast, in muscles of dystrophic or very old animals, disruptions in DGC structure and function impair lateral transmission of force causing instability and increased susceptibility of fibres to contraction-induced injury.
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Affiliation(s)
- Krishnan S Ramaswamy
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109-2200, USA
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