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De Paola E, Forcina L, Pelosi L, Pisu S, La Rosa P, Cesari E, Nicoletti C, Madaro L, Mercatelli N, Biamonte F, Nobili A, D'Amelio M, De Bardi M, Volpe E, Caporossi D, Sette C, Musarò A, Paronetto MP. Sam68 splicing regulation contributes to motor unit establishment in the postnatal skeletal muscle. Life Sci Alliance 2020; 3:3/10/e201900637. [PMID: 32753528 PMCID: PMC7409371 DOI: 10.26508/lsa.201900637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 01/08/2023] Open
Abstract
Sam68 ensures the establishment of neuromuscular junctions (NMJs) and motor unit integrity by orchestrating a neuronal splicing program. RNA-binding proteins orchestrate the composite life of RNA molecules and impact most physiological processes, thus underlying complex phenotypes. The RNA-binding protein Sam68 regulates differentiation processes by modulating splicing, polyadenylation, and stability of select transcripts. Herein, we found that Sam68−/− mice display altered regulation of alternative splicing in the spinal cord of key target genes involved in synaptic functions. Analysis of the motor units revealed that Sam68 ablation impairs the establishment of neuromuscular junctions and causes progressive loss of motor neurons in the spinal cord. Importantly, alterations of neuromuscular junction morphology and properties in Sam68−/− mice correlate with defects in muscle and motor unit integrity. Sam68−/− muscles display defects in postnatal development, with manifest signs of atrophy. Furthermore, fast-twitch muscles in Sam68−/− mice show structural features typical of slow-twitch muscles, suggesting alterations in the metabolic and functional properties of myofibers. Collectively, our data identify a key role for Sam68 in muscle development and suggest that proper establishment of motor units requires timely expression of synaptic splice variants.
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Affiliation(s)
- Elisa De Paola
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy.,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Laura Forcina
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Laura Pelosi
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Simona Pisu
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Piergiorgio La Rosa
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Eleonora Cesari
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Carmine Nicoletti
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Luca Madaro
- Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Neri Mercatelli
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy.,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Filippo Biamonte
- Institute of Biochemistry and Clinical Biochemistry, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Annalisa Nobili
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Marcello D'Amelio
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Marco De Bardi
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Elisabetta Volpe
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Daniela Caporossi
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy
| | - Claudio Sette
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy .,Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Antonio Musarò
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy .,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
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2
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Watanabe D, Hatakeyama K, Ikegami R, Eshima H, Yagishita K, Poole DC, Kano Y. Sex differences in mitochondrial Ca 2+ handling in mouse fast-twitch skeletal muscle in vivo. J Appl Physiol (1985) 2020; 128:241-251. [PMID: 31917626 DOI: 10.1152/japplphysiol.00230.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We investigated sex differences in mitochondrial Ca2+ handling properties in mouse fast-twitch skeletal muscle. Changes in cytoplasmic Ca2+ concentration ([Ca2+]cyto) were measured in vivo using tibialis anterior muscles from male and female mice. The muscles were exposed to increasing concentrations of cyclopiazonic acid [CPA; sarcoplasmic reticulum (SR) Ca2+-ATPase inhibitor] (from 10 to 30 to 50 μM at 10 min intervals). Thirty minutes after treatment, [Ca2+]cyto was increased by 31.6 ± 2.0% and 13.5 ± 4.5% of initial [Ca2+]cyto in male and female muscles, respectively, and there was a significant difference between sexes. However, muscle preincubation for 5 min with 10 μM carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (an inhibitor of mitochondria Ca2+ uptake) eradicated this difference between sexes with respect to the CPA-induced [Ca2+]cyto increase. Both intermyofibrillar mitochondrial number and volume, assessed in longitudinal fiber sections, were higher in females compared with males (mitochondria number: 13.1 ± 1.0 in males vs. 19.9 ± 2.3 in females; mitochondrial volume: 0.034 ± 0.004 μm3/μm3 fiber volume in males vs. 0.066 ± 0.008 μm3/μm3 fiber volume in females, both P < 0.05). There were no sex differences in the content of SR Ca2+-ATPase, mitochondrial Ca2+ uniporter, mitofusin (Mfn) 1, or Mfn2. These results suggest that 1) mitochondrial Ca2+ uptake ability is greater in female than male myocytes, and 2) this superior Ca2+ uptake ability of female myocytes is due, partly, to the higher intermyofibrillar mitochondrial content but not to the expression of mitochondrial proteins related to mitochondrial Ca2+ uptake.NEW & NOTEWORTHY This investigation presents evidence that female versus male fast-twitch muscle exhibits a greater mitochondrial calcium ion uptake capability that is partly conferred by the higher intermyofibrillar mitochondrial volume density.
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Affiliation(s)
- Daiki Watanabe
- Bioscience and Technology Program, Department of Engineering Sciences, University of Electro-Communications, Tokyo, Japan.,Graduate School of Integrated Arts and Sciences, Hiroshima University, Hiroshima, Japan
| | - Koji Hatakeyama
- Bioscience and Technology Program, Department of Engineering Sciences, University of Electro-Communications, Tokyo, Japan
| | - Ryo Ikegami
- Bioscience and Technology Program, Department of Engineering Sciences, University of Electro-Communications, Tokyo, Japan
| | - Hiroaki Eshima
- Diabetes & Metabolism Research Center, University of Utah, Salt Lake City, Utah
| | - Kazuyoshi Yagishita
- Clinical Center for Sports Medicine and Sports Dentistry, Hyperbaric Medical Center/Sports Medicine Clinical Center, Medical Hospital of Tokyo Medical and Dental University, Tokyo, Japan
| | - David C Poole
- Departments of Anatomy & Physiology and of Kinesiology, Kansas State University, Manhattan, Kansas
| | - Yutaka Kano
- Bioscience and Technology Program, Department of Engineering Sciences, University of Electro-Communications, Tokyo, Japan.,Center for Neuroscience and Biomedical Engineering, University of Electro-Communications, Chofu, Tokyo, Japan
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Rasool S, Geetha T, Broderick TL, Babu JR. High Fat With High Sucrose Diet Leads to Obesity and Induces Myodegeneration. Front Physiol 2018; 9:1054. [PMID: 30258366 PMCID: PMC6143817 DOI: 10.3389/fphys.2018.01054] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 07/16/2018] [Indexed: 12/21/2022] Open
Abstract
Skeletal muscle utilizes both free fatty acids (FFAs) and glucose that circulate in the blood stream. When blood glucose levels acutely increase, insulin stimulates muscle glucose uptake, oxidation, and glycogen synthesis. Under these conditions, skeletal muscle preferentially oxidizes glucose while the oxidation of fatty acids (FAs) oxidation is reciprocally decreased. In metabolic disorders associated with insulin resistance, such as diabetes and obesity, both glucose uptake, and utilization muscle are significantly reduced causing FA oxidation to provide the majority of ATP for metabolic processes and contraction. Although the causes of this metabolic inflexibility or disrupted "glucose-fatty acid cycle" are largely unknown, a diet high in fat and sugar (HFS) may be a contributing factor. This metabolic inflexibility observed in models of obesity or with HFS feeding is detrimental because high rates of FA oxidation in skeletal muscle can lead to the buildup of toxic metabolites of fat metabolism and the accumulation of pro-inflammatory cytokines, which further exacerbate the insulin resistance. Further, HFS leads to skeletal muscle atrophy with a decrease in myofibrillar proteins and phenotypically characterized by loss of muscle mass and strength. Overactivation of ubiquitin proteasome pathway, oxidative stress, myonuclear apoptosis, and mitochondrial dysfunction are some of the mechanisms involved in muscle atrophy induced by obesity or in mice fed with HFS. In this review, we will discuss how HFS diet negatively impacts the various physiological and metabolic mechanisms in skeletal muscle.
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Affiliation(s)
- Suhail Rasool
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
| | - Thangiah Geetha
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
| | - Tom L Broderick
- Laboratory of Diabetes and Exercise Metabolism, Department of Physiology, Midwestern University, Glendale, AZ, United States
| | - Jeganathan R Babu
- Department of Nutrition, Dietetics, and Hospitality Management, Auburn University, Auburn, AL, United States
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Hering T, Braubach P, Landwehrmeyer GB, Lindenberg KS, Melzer W. Fast-to-Slow Transition of Skeletal Muscle Contractile Function and Corresponding Changes in Myosin Heavy and Light Chain Formation in the R6/2 Mouse Model of Huntington's Disease. PLoS One 2016; 11:e0166106. [PMID: 27820862 PMCID: PMC5098792 DOI: 10.1371/journal.pone.0166106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/24/2016] [Indexed: 11/18/2022] Open
Abstract
Huntington´s disease (HD) is a hereditary neurodegenerative disease resulting from an expanded polyglutamine sequence (poly-Q) in the protein huntingtin (HTT). Various studies report atrophy and metabolic pathology of skeletal muscle in HD and suggest as part of the process a fast-to-slow fiber type transition that may be caused by the pathological changes in central motor control or/and by mutant HTT in the muscle tissue itself. To investigate muscle pathology in HD, we used R6/2 mice, a common animal model for a rapidly progressing variant of the disease expressing exon 1 of the mutant human gene. We investigated alterations in the extensor digitorum longus (EDL), a typical fast-twitch muscle, and the soleus (SOL), a slow-twitch muscle. We focussed on mechanographic measurements of excised muscles using single and repetitive electrical stimulation and on the expression of the various myosin isoforms (heavy and light chains) using dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole muscle and single fiber preparations. In EDL of R6/2, the functional tests showed a left shift of the force-frequency relation and decrease in specific force. Moreover, the estimated relative contribution of the fastest myosin isoform MyHC IIb decreased, whereas the contribution of the slower MyHC IIx isoform increased. An additional change occurred in the alkali MyLC forms showing a decrease in 3f and an increase in 1f level. In SOL, a shift from fast MyHC IIa to the slow isoform I was detectable in male R6/2 mice only, and there was no evidence of isoform interconversion in the MyLC pattern. These alterations point to a partial remodeling of the contractile apparatus of R6/2 mice towards a slower contractile phenotype, predominantly in fast glycolytic fibers.
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Affiliation(s)
- Tanja Hering
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Department of Neurology, Ulm University, Ulm, Germany
| | - Peter Braubach
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | | | | | - Werner Melzer
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- * E-mail:
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5
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Hyatt JPK, Nguyen L, Hall AE, Huber AM, Kocan JC, Mattison JA, de Cabo R, LaRocque JR, Talmadge RJ. Muscle-Specific Myosin Heavy Chain Shifts in Response to a Long-Term High Fat/High Sugar Diet and Resveratrol Treatment in Nonhuman Primates. Front Physiol 2016; 7:77. [PMID: 26973542 PMCID: PMC4773583 DOI: 10.3389/fphys.2016.00077] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/15/2016] [Indexed: 01/14/2023] Open
Abstract
Shifts in myosin heavy chain (MHC) expression within skeletal muscle can be induced by a host of stimuli including, but not limited to, physical activity, alterations in neural activity, aging, and diet or obesity. Here, we hypothesized that both age and a long-term (2 year) high fat/high sugar diet (HFS) would induce a slow to fast MHC shift within the plantaris, soleus, and extensor digitorum longus (EDL) muscles from rhesus monkeys. Furthermore, we tested whether supplementation with resveratrol, a naturally occurring compound that has been attributed with augmenting aerobic potential through mitochondrial proliferation, would counteract any diet-induced MHC changes by promoting a fast to slow isoform switch. In general, we found that MHC isoforms were not altered by aging during mid-life. The HFS diet had the largest impact within the soleus muscle where the greatest slow to fast isoform shifts were observed in both mRNA and protein indicators. As expected, long-term resveratrol treatment counteracted, or blunted, these diet-induced shifts within the soleus muscle. The plantaris muscle also demonstrated a fast-to-slow phenotypic response to resveratrol treatment. In conclusion, diet or resveratrol treatment impacts skeletal muscle phenotype in a muscle-specific manner and resveratrol supplementation may be one approach for promoting the fatigue-resistant MHC (type I) isoform especially if its expression is blunted as a result of a long-term high fat/sugar diet.
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Affiliation(s)
| | - Lisa Nguyen
- Department of Biological Sciences, California State Polytechnic University Pomona, CA, USA
| | - Allison E Hall
- Department of Human Science, Georgetown University Washington, DC, USA
| | - Ashley M Huber
- Department of Human Science, Georgetown University Washington, DC, USA
| | - Jessica C Kocan
- Department of Human Science, Georgetown University Washington, DC, USA
| | - Julie A Mattison
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health Baltimore, MD, USA
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health Baltimore, MD, USA
| | | | - Robert J Talmadge
- Department of Biological Sciences, California State Polytechnic University Pomona, CA, USA
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Gorski JP, Huffman NT, Vallejo J, Brotto L, Chittur SV, Breggia A, Stern A, Huang J, Mo C, Seidah NG, Bonewald L, Brotto M. Deletion of Mbtps1 (Pcsk8, S1p, Ski-1) Gene in Osteocytes Stimulates Soleus Muscle Regeneration and Increased Size and Contractile Force with Age. J Biol Chem 2015; 291:4308-22. [PMID: 26719336 DOI: 10.1074/jbc.m115.686626] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Indexed: 12/28/2022] Open
Abstract
Conditional deletion of Mbtps1 (cKO) protease in bone osteocytes leads to an age-related increase in mass (12%) and in contractile force (30%) in adult slow twitch soleus muscles (SOL) with no effect on fast twitch extensor digitorum longus muscles. Surprisingly, bone from 10-12-month-old cKO animals was indistinguishable from controls in size, density, and morphology except for a 25% increase in stiffness. cKO SOL exhibited increased expression of Pax7, Myog, Myod1, Notch, and Myh3 and 6-fold more centralized nuclei, characteristics of postnatal regenerating muscle, but only in type I myosin heavy chain-expressing cells. Increased expression of gene pathways mediating EGF receptor signaling, circadian exercise, striated muscle contraction, and lipid and carbohydrate oxidative metabolism were also observed in cKO SOL. This muscle phenotype was not observed in 3-month-old mice. Although Mbtps1 mRNA and protein expression was reduced in cKO bone osteocytes, no differences in Mbtps1 or cre recombinase expression were observed in cKO SOL, explaining this age-related phenotype. Understanding bone-muscle cross-talk may provide a fresh and novel approach to prevention and treatment of age-related muscle loss.
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Affiliation(s)
- Jeff P Gorski
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry,
| | - Nichole T Huffman
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry
| | - Julian Vallejo
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Leticia Brotto
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Sridar V Chittur
- Center for Functional Genomics, University at Albany, Rensselaer, New York 12144
| | | | - Amber Stern
- School of Computing and Engineering, University of Missouri-Kansas City, Kansas City, Missouri 64108, Engineering Systems, Inc., Charlotte, North Carolina 28277, and
| | - Jian Huang
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Chenglin Mo
- Muscle Biology Research Group, School of Nursing and Health Studies, and
| | - Nabil G Seidah
- Institut de Recherches Cliniques Montreal, Montreal, Quebec H2W IR7, Canada
| | - Lynda Bonewald
- From the Department of Oral and Craniofacial Sciences, University of Missouri-Kansas City Center of Excellence in the Study of Dental and Musculoskeletal Tissues, School of Dentistry
| | - Marco Brotto
- Muscle Biology Research Group, School of Nursing and Health Studies, and
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7
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Rizzuto E, Pisu S, Musarò A, Del Prete Z. Measuring Neuromuscular Junction Functionality in the SOD1(G93A) Animal Model of Amyotrophic Lateral Sclerosis. Ann Biomed Eng 2015; 43:2196-206. [PMID: 25631208 PMCID: PMC4516896 DOI: 10.1007/s10439-015-1259-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 01/17/2015] [Indexed: 12/12/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that leads to motor neuron degeneration, alteration in neuromuscular junctions (NMJs), muscle atrophy, and paralysis. To investigate the NMJ functionality in ALS we tested, in vitro, two innervated muscle types excised from SOD1G93A transgenic mice at the end-stage of the disease: the Soleus, a postural muscle almost completely paralyzed at that stage, and the diaphragm, which, on the contrary, is functional until death. To this aim we employed an experimental protocol that combined two types of electrical stimulation: the direct stimulation and the stimulation through the nerve. The technique we applied allowed us to determine the relevance of NMJ functionality separately from muscle contractile properties in SOD1G93A animal model. Functional measurements revealed that the muscle contractility of transgenic diaphragms is almost unaltered in comparison to control muscles, while transgenic Soleus muscles were severely compromised. In contrast, when stimulated via the nerve, both transgenic muscle types showed a strong decrease of the contraction force, a slowing down of the kinetic parameters, as well as alterations in the neurotransmission failure parameter. All together, these results confirm a severely impaired functionality in the SOD1G93A neuromuscular junctions.
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Affiliation(s)
- Emanuele Rizzuto
- Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, 00184, Rome, Italy,
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8
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Soukup T. Effects of long-term thyroid hormone level alterations, n-3 polyunsaturated fatty acid supplementation and statin administration in rats. Physiol Res 2014; 63:S119-31. [PMID: 24564652 DOI: 10.33549/physiolres.932623] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Thyroid hormones (THs) play multiple roles in the organism and alterations of their levels can result in many pathological changes. Currently, we use hyperthyroid and hypothyroid rats as "models of a diseased organism" and analyze whether n-3 polyunsaturated fatty acids (n-3 PUFA) administration can ameliorate TH-induced pathophysiological changes. We investigate myosin heavy chain composition, calsequestrin levels, changes in cardiac tissue remodeling and cell-to-cell communication, expression of protein kinases, mitochondrial functions, oxidative stress markers and cell death, changes in serum lipid levels, activities of key enzymes of thyroid hormone metabolism, activity of acetylcholine esterase and membrane anisotropy, as well as mobile behavior and thermal sensitivity. Additionally we also mention our pilot experiments dealing with the effect of statin administration on skeletal muscles and sensory functions. As THs and n-3 PUFA possess multiple sites of potential action, we hope that our complex research will contribute to a better understanding of their actions, which can be useful in the treatment of different pathophysiological events including cardiac insufficiency in humans.
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Affiliation(s)
- T Soukup
- Department of Functional Morphology, Institute of Physiology Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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9
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Effect of altered innervation and thyroid hormones on myosin heavy chain expression and fiber type transitions: a mini-review. Histochem Cell Biol 2014; 143:123-30. [DOI: 10.1007/s00418-014-1276-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2014] [Indexed: 01/19/2023]
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10
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ŽURMANOVÁ J, SOUKUP T. Comparison of Myosin Heavy Chain mRNAs, Protein Isoforms and Fiber Type Proportions in the Rat Slow and Fast Muscles. Physiol Res 2013; 62:445-53. [DOI: 10.33549/physiolres.932418] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We studied the expression of myosin heavy chain isoforms at mRNA and protein levels as well as fiber type composition in the fast extensor digitorum longus (EDL) and slow soleus (SOL) twitch muscles of adult inbred Lewis strain rats. Comparison of the results from Real Time RT-PCR, SDS-PAGE and fiber type analysis showed corresponding proportions of MyHC transcripts (MyHC-1, -2a, -2x/d, -2b), protein isoforms (MyHC-1, -2a, -2x/d, -2b) and fiber types (type 1, 2A, 2X/D, 2B) in both muscles. Furthermore, we found that slow MyHC-1 mRNA expression in the SOL was up to three orders higher than that of fast MyHC transcripts. This finding can explain the predominance of MyHC-1 isoform and fiber type 1 and the absence of pure 2X/D and 2B fibers in the SOL muscle. Based on our data presenting quantitative evidence of corresponding proportions between mRNA level, protein content and fiber type composition, we suggest that the Real Time RT-PCR technique can be used as a routine method for analysis of muscle composition changes and could be advantageous for the analysis of scant biological samples such as muscle biopsies in humans.
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Affiliation(s)
| | - T. SOUKUP
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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11
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Mitogen-activated protein kinase-activated protein kinases 2 and 3 regulate SERCA2a expression and fiber type composition to modulate skeletal muscle and cardiomyocyte function. Mol Cell Biol 2013; 33:2586-602. [PMID: 23608535 DOI: 10.1128/mcb.01692-12] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The mitogen-activated protein kinase (MAPK)-activated protein kinases 2 and 3 (MK2/3) represent protein kinases downstream of the p38 MAPK. Using MK2/3 double-knockout (MK2/3(-/-)) mice, we analyzed the role of MK2/3 in cross-striated muscle by transcriptome and proteome analyses and by histology. We demonstrated enhanced expression of the slow oxidative skeletal muscle myofiber gene program, including the peroxisome proliferator-activated receptor gamma (PPARγ) coactivator 1α (PGC-1α). Using reporter gene and electrophoretic gel mobility shift assays, we demonstrated that MK2 catalytic activity directly regulated the promoters of the fast fiber-specific myosin heavy-chain IId/x and the slow fiber-specific sarco/endoplasmic reticulum Ca(2+)-ATPase 2 (SERCA2) gene. Elevated SERCA2a gene expression caused by a decreased ratio of transcription factor Egr-1 to Sp1 was associated with accelerated relaxation and enhanced contractility in MK2/3(-/-) cardiomyocytes, concomitant with improved force parameters in MK2/3(-/-) soleus muscle. These results link MK2/3 to the regulation of calcium dynamics and identify enzymatic activity of MK2/3 as a critical factor for modulating cross-striated muscle function by generating a unique muscle phenotype exhibiting both reduced fatigability and enhanced force in MK2/3(-/-) mice. Hence, the p38-MK2/3 axis may represent a novel target for the design of therapeutic strategies for diseases related to fiber type changes or impaired SERCA2 function.
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12
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Ribarič S, Čebašek V. Simultaneous visualization of myosin heavy chain isoforms in single muscle sections. Cells Tissues Organs 2013; 197:312-21. [PMID: 23306777 DOI: 10.1159/000345424] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/25/2012] [Indexed: 11/19/2022] Open
Abstract
We developed a staining protocol that enables simultaneous visualization of myosin heavy chain (MHC) pure and hybrid muscle fiber types in rat skeletal muscle. Up to eight different muscle fiber types can be visualized in a single section of the rat extensor digitorum longus muscle, which contains all four adult MHC isoforms and shows plasticity during the denervation-reinnervation process. Triple immunofluorescent staining of MHC-1, MHC-2a and MHC-2b with primary antibodies BA-D5 (isotype IgG2b), SC-71 (isotype IgG1) and BF-F3 (isotype IgM) and with three fluorophore-labeled isotype-specific secondary antibodies displays different muscle fiber types in a merged image of red, green and blue channels, each in its own color. Immunoperoxidase staining with primary antibody 6H1 directed against MHC-2x can be additionally applied on the same tissue section to facilitate the identification of muscle fibers containing MHC-2x. Triple staining can also be used in combination with other staining procedures to derive more information about the number of capillaries or the oxidative potential of muscle fiber types. Simultaneous visualization of multiple fiber types in a single merged image enables economical use of muscle samples and provides simple and rapid identification of all fiber types that are present in rat limb muscles.
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Affiliation(s)
- Samo Ribarič
- Institute of Pathophysiology, Medical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia
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13
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Baylor SM, Hollingworth S. Intracellular calcium movements during excitation-contraction coupling in mammalian slow-twitch and fast-twitch muscle fibers. ACTA ACUST UNITED AC 2012; 139:261-72. [PMID: 22450485 PMCID: PMC3315149 DOI: 10.1085/jgp.201210773] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In skeletal muscle fibers, action potentials elicit contractions by releasing calcium ions (Ca2+) from the sarcoplasmic reticulum. Experiments on individual mouse muscle fibers micro-injected with a rapidly responding fluorescent Ca2+ indicator dye reveal that the amount of Ca2+ released is three- to fourfold larger in fast-twitch fibers than in slow-twitch fibers, and the proportion of the released Ca2+ that binds to troponin to activate contraction is substantially smaller.
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Affiliation(s)
- Stephen M Baylor
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA
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Meissner JD, Freund R, Krone D, Umeda PK, Chang KC, Gros G, Scheibe RJ. Extracellular signal-regulated kinase 1/2-mediated phosphorylation of p300 enhances myosin heavy chain I/beta gene expression via acetylation of nuclear factor of activated T cells c1. Nucleic Acids Res 2011; 39:5907-25. [PMID: 21498542 PMCID: PMC3152325 DOI: 10.1093/nar/gkr162] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The nuclear factor of activated T-cells (NFAT) c1 has been shown to be essential for Ca2+-dependent upregulation of myosin heavy chain (MyHC) I/β expression during skeletal muscle fiber type transformation. Here, we report activation of extracellular signal-regulated kinase (ERK) 1/2 in Ca2+-ionophore-treated C2C12 myotubes and electrostimulated soleus muscle. Activated ERK1/2 enhanced NFATc1-dependent upregulation of a −2.4 kb MyHCI/β promoter construct without affecting subcellular localization of endogenous NFATc1. Instead, ERK1/2-augmented phosphorylation of transcriptional coactivator p300, promoted its recruitment to NFATc1 and increased NFATc1–DNA binding to a NFAT site of the MyHCI/β promoter. In line, inhibition of ERK1/2 signaling abolished the effects of p300. Comparison between wild-type p300 and an acetyltransferase-deficient mutant (p300DY) indicated increased NFATc1–DNA binding as a consequence of p300-mediated acetylation of NFATc1. Activation of the MyHCI/β promoter by p300 depends on two conserved acetylation sites in NFATc1, which affect DNA binding and transcriptional stimulation. NFATc1 acetylation occurred in Ca2+-ionophore treated C2C12 myotubes or electrostimulated soleus. Finally, endogenous MyHCI/β gene expression in C2C12 myotubes was strongly inhibited by p300DY and a mutant deficient in ERK phosphorylation sites. In conclusion, ERK1/2-mediated phosphorylation of p300 is crucial for enhancing NFATc1 transactivation function by acetylation, which is essential for Ca2+-induced MyHCI/β expression.
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Affiliation(s)
- Joachim D Meissner
- Department of Vegetative Physiology, Institute of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
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Goncalves MD, Pistilli EE, Balduzzi A, Birnbaum MJ, Lachey J, Khurana TS, Ahima RS. Akt deficiency attenuates muscle size and function but not the response to ActRIIB inhibition. PLoS One 2010; 5:e12707. [PMID: 20856813 PMCID: PMC2939888 DOI: 10.1371/journal.pone.0012707] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 08/23/2010] [Indexed: 11/19/2022] Open
Abstract
Background Akt is a critical mediator of developmental skeletal muscle growth. Treatment with a soluble ActRIIB fusion protein (ActRIIB-mFc) increases skeletal muscle mass and strength by inhibiting myostatin and related peptides. Recent in vitro studies have suggested that Akt signaling is necessary for the ability of ActRIIB inhibition to induce muscle hypertrophy. Thus, we hypothesized that mice deficient in either Akt1 or Akt2 would not respond to in vivo inhibition of ActRIIB with ActRIIB-mFc treatment. Methodology and Principal Findings We analyzed body composition and muscle parameters in wild-type C57BL/6J and Akt1 and Akt2 knockout mice, and compared the responses to blockade of ActRIIB signaling via ActRIIB-mFc treatment. Mice lacking Akt1 or Akt2 had reduced muscle mass, grip strength and contractile force. However, deficiency of Akt1 or Akt2 did not prevent the ability of ActRIIB-mFc treatment to induce muscle hypertrophy, or increase grip strength and contractile force. Akt1 and Akt2 deficient mice responded similarly as wild type mice to ActRIIB-mFc treatment by increasing fiber size. Conclusions and Significance Akt1 and Akt2 are important for the regulation of skeletal muscle mass and function. However, these Akt isoforms are not essential for the ability of ActRIIB inhibition to regulate muscle size, fiber type, strength or contractile force.
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Affiliation(s)
- Marcus D. Goncalves
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Emidio E. Pistilli
- Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Anthony Balduzzi
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Morris J. Birnbaum
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Jennifer Lachey
- Acceleron Pharma, Cambridge, Massachusetts, United States of America
| | - Tejvir S. Khurana
- Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Rexford S. Ahima
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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16
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Measuring tendon properties in mdx mice: Cell viability and viscoelastic characteristics. J Biomech 2009; 42:2243-8. [DOI: 10.1016/j.jbiomech.2009.06.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 06/22/2009] [Accepted: 06/25/2009] [Indexed: 11/18/2022]
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17
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Viggiano D. The hyperactive syndrome: metanalysis of genetic alterations, pharmacological treatments and brain lesions which increase locomotor activity. Behav Brain Res 2008; 194:1-14. [PMID: 18656502 DOI: 10.1016/j.bbr.2008.06.033] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Revised: 06/26/2008] [Accepted: 06/29/2008] [Indexed: 01/01/2023]
Abstract
The large number of transgenic mice realized thus far with different purposes allows addressing new questions, such as which animals, over the entire set of transgenic animals, show a specific behavioural abnormality. In the present study, we have used a metanalytical approach to organize a database of genetic modifications, brain lesions and pharmacological interventions that increase locomotor activity in animal models. To further understand the resulting data set, we have organized a second database of the alterations (genetic, pharmacological or brain lesions) that reduce locomotor activity. Using this approach, we estimated that 1.56% of the genes in the genome yield to hyperactivity and 0.75% of genes produce hypoactivity when altered. These genes have been classified into genes for neurotransmitter systems, hormonal, metabolic systems, ion channels, structural proteins, transcription factors, second messengers and growth factors. Finally, two additional classes included animals with neurodegeneration and inner ear abnormalities. The analysis of the database revealed several unexpected findings. First, the genes that, when mutated, induce hyperactive behaviour do not pertain to a single neurotransmitter system. In fact, alterations in most neurotransmitter systems can give rise to a hyperactive phenotype. In contrast, fewer changes can decrease locomotor activity. Specifically, genetic and pharmacological alterations that enhance the dopamine, orexin, histamine, cannabinoids systems or that antagonize the cholinergic system induce an increase in locomotor activity. Similarly, imbalances in the two main neurotransmitters of the nervous system, GABA and glutamate usually result in hyperactive behaviour. It is remarkable that no genetic alterations pertaining to the GABA system have been reported to reduce locomotor behaviour. Other neurotransmitters, such as norepinephrine and serotonin, have a more complex influence. For instance, a decrease in norepinephrine synthesis usually results in hypoactive behaviour. However, a chronic increase in norepinephrine may result in hypoactivity too. Similarly, changes in both directions of serotonin levels may reduce locomotor activity, whereas alterations in specific serotonin receptors can induce hyperactivity. The lesion of at least 12 different brain regions can increase locomotor activity too. Comparatively, few focal lesions decrease locomotor activity. Finally, a large number of toxic events can increase locomotor activity, particularly if delivered during the prepuberal time window. These data show that there is a net imbalance in the number of altered genes/brain lesions/toxics that induce hyperactivity versus hypoactive behaviour. Although some of these data may be explained in terms of the activating role of subcortical systems (such as catecholamines), the larger number of alterations that induce hyperactivity suggests a different scenario. Specifically, we hypothesize (i) the existence of a control system that continuously inhibit a basally hyperactive locomotor tone and (ii) that this control system is highly vulnerable (intrinsic fragility) to any change in the genetic asset or to any toxic/drug delivered during prepuberal stages. Brain lesion studies suggest that the putative control system is located along an axis that connects the olfactory bulb and the enthorhinal cortex (enthorhinal-hippocampal-septal-prefrontal cortex-olfactory bulb axis). We suggest that the increased locomotor activity in many psychiatric diseases may derive from the interference with the development of this brain axis during a specific postnatal time window.
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Affiliation(s)
- Davide Viggiano
- Department of Health Sciences, Faculty of Scienze del Benessere, University of Molise, Via De Sanctis III Edificio Polifunzionale, 86100 Campobasso, Italy.
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18
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Measuring mechanical properties, including isotonic fatigue, of fast and slow MLC/mIgf-1 transgenic skeletal muscle. Ann Biomed Eng 2008; 36:1281-90. [PMID: 18415017 DOI: 10.1007/s10439-008-9496-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Accepted: 04/02/2008] [Indexed: 10/22/2022]
Abstract
Contractile properties of fast-twitch (EDL) and slow-twitch (soleus) skeletal muscles were measured in MLC/mIgf-1 transgenic and wild-type mice. MLC/mIgf-1 mice express the local factor mIgf-1 under the transcriptional control of MLC promoter, selectively activated in fast-twitch muscle fibers. Isolated muscles were studied in vitro in both isometric and isotonic conditions. We used a rapid "ad hoc" testing protocol that measured, in a single procedure, contraction time, tetanic force, Hill's (F-v) curve, power curve and isotonic muscle fatigue. Transgenic soleus muscles did not differ from wild-type with regard to any measured variable. In contrast, transgenic EDL muscles displayed a hypertrophic phenotype, with a mass increase of 29.2% compared to wild-type. Absolute tetanic force increased by 21.5% and absolute maximum power by 34.1%. However, when normalized to muscle cross-sectional area and mass, specific force and normalized power were the same in transgenic and wild-type EDL muscles, revealing that mIgf-1 expression induces a functional hypertrophy without altering fibrotic tissue accumulation. Isotonic fatigue behavior did not differ between transgenic and wild-type muscles, suggesting that the ability of mIgf-1 transgenic muscle to generate a considerable higher absolute power did not affect its resistance to fatigue.
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19
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Jin TE, Wernig A, Witzemann V. Changes in acetylcholine receptor function induce shifts in muscle fiber type composition. FEBS J 2008; 275:2042-54. [DOI: 10.1111/j.1742-4658.2008.06359.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Bedu E, Desplanches D, Pequignot J, Bordier B, Desvergne B. Double gene deletion reveals the lack of cooperation between PPARα and PPARβ in skeletal muscle. Biochem Biophys Res Commun 2007; 357:877-81. [PMID: 17466944 DOI: 10.1016/j.bbrc.2007.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 04/02/2007] [Indexed: 11/19/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of most of the pathways linked to lipid metabolism. PPARalpha and PPARbeta isotypes are known to regulate muscle fatty acid oxidation and a reciprocal compensation of their function has been proposed. Herein, we investigated muscle contractile and metabolic phenotypes in PPARalpha-/-, PPARbeta-/-, and double PPARalpha-/- beta-/- mice. Heart and soleus muscle analyses show that the deletion of PPARalpha induces a decrease of the HAD activity (beta-oxidation) while soleus contractile phenotype remains unchanged. A PPARbeta deletion alone has no effect. However, these mild phenotypes are not due to a reciprocal compensation of PPARbeta and PPARalpha functions since double gene deletion PPARalpha-PPARbeta mostly reproduces the null PPARalpha-mediated reduced beta-oxidation, in addition to a shift from fast to slow fibers. In conclusion, PPARbeta is not required for maintaining skeletal muscle metabolic activity and does not compensate the lack of PPARalpha in PPARalpha null mice.
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Affiliation(s)
- E Bedu
- Center of Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
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21
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Gelhaye M, Martrette JM, Legrand-Frossi C, Trabalon M. Myosin heavy chain expression and muscle adaptation to chronic oral breathing in rat. Respir Physiol Neurobiol 2006; 154:443-52. [PMID: 16466973 DOI: 10.1016/j.resp.2005.12.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Revised: 12/20/2005] [Accepted: 12/21/2005] [Indexed: 10/25/2022]
Abstract
The purpose of this study was to establish if early chronic oral breathing could induce an ultra-structural adaptation of the diaphragm and orofacial muscles related to oral or nasal breathing. Therefore, we performed a bilateral nasal obstruction at day 8 on rat pups and the myosin heavy chain (MHC) composition of the muscles was analyzed at day 21. Nasal obstruction and the related switch to chronic oral breathing were associated with impaired growth, atrophy of olfactory bulbs, hypertrophy of adrenal glands and reduced muscle growth for all muscles studied except the diaphragm. Furthermore, we detected a smaller decrease of MHC 2b compared to MHC 2a and 2x in levator nasolabialis, a muscle involved with nasal breathing. In masseter superficialis and anterior digastric involved with oral breathing, we observed a smaller decrease of MHC 2a compared to MHC 2b or 2x, respectively. No difference was detected in the diaphragm MHC expression of oral breathing animals. Since the relative expression of fatigue resistant MHC fiber types increased in muscles involved with oral breathing, orofacial muscles seem to present a profile in MHC adapted to the transition from nasal to oral breathing, facilitating respiration.
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Affiliation(s)
- M Gelhaye
- Physiologie du Comportement, Faculté des Sciences et Techniques, CEPE, UPR-CNRS 9010, BP 239, 54506 Vandoeuvre-lès-Nancy Cedex, France
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