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Huang R, Kibschull M, Briollais L, Pausova Z, Murphy K, Kingdom J, Lye S, Luo ZC. Cord blood myostatin concentrations by gestational diabetes mellitus and fetal sex. Front Endocrinol (Lausanne) 2023; 14:1018779. [PMID: 36875483 PMCID: PMC9975152 DOI: 10.3389/fendo.2023.1018779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 01/25/2023] [Indexed: 02/17/2023] Open
Abstract
INTRODUCTION Myostatin is a member of the transforming growth factor β superfamily, and is mainly secreted from skeletal muscle. Animal studies have demonstrated that deficiency in myostatin promotes muscle growth and protects against insulin resistance. In humans, gestational diabetes mellitus (GDM) affects fetal insulin sensitivity. Females are more insulin resistant and weigh less than males at birth. We sought to assess whether cord blood myostatin concentrations vary by GDM and fetal sex, and the associations with fetal growth factors. METHODS In a study of 44 GDM and 66 euglycemic mother-newborn dyads, myostatin, insulin, proinsulin, insulin-like growth factor (IGF)-1, IGF-2 and testosterone were measured in cord blood samples. RESULTS Cord blood myostatin concentrations were similar in GDM vs. euglycemic pregnancies (mean ± SD: 5.5 ± 1.4 vs. 5.8 ± 1.4 ng/mL, P=0.28), and were higher in males vs. females (6.1 ± 1.6 vs. 5.3 ± 1.0 ng/mL, P=0.006). Adjusting for gestational age, myostatin was negatively correlated with IGF-2 (r=-0.23, P=0.02), but not correlated with IGF-1 (P=0.60) or birth weight (P=0.23). Myostatin was strongly correlated with testosterone in males (r=0.56, P<0.001), but not in females (r=-0.08, P=0.58) (test for difference in r, P<0.001). Testosterone concentrations were higher in males vs. females (9.5 ± 6.4 vs. 7.1 ± 4.0 nmol/L, P=0.017), and could explain 30.0% (P=0.039) of sex differences in myostatin concentrations. DISCUSSION The study is the first to demonstrate that GDM does not impact cord blood myostatin concentration, but fetal sex does. The higher myostatin concentrations in males appear to be partly mediated by higher testosterone concentrations. These findings shed novel insight on developmental sex differences in insulin sensitivity regulation relevant molecules.
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Affiliation(s)
- Rong Huang
- Lunenfeld-Tanenbaum Research Institute, Prosserman Centre for Population Health Research, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Mark Kibschull
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
| | - Laurent Briollais
- Lunenfeld-Tanenbaum Research Institute, Prosserman Centre for Population Health Research, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
- Institute of Health Policy, Management and Evaluation, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Zdenka Pausova
- The Hospital for Sick Children, Toronto, ON, Canada
- Departments of Physiology and Nutritional Sciences, University of Toronto, Toronto, ON, Canada
| | - Kellie Murphy
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
| | - John Kingdom
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
| | - Stephen Lye
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, University of Toronto, Toronto, ON, Canada
| | - Zhong-Cheng Luo
- Lunenfeld-Tanenbaum Research Institute, Prosserman Centre for Population Health Research, Mount Sinai Hospital, and Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
- Department of Obstetrics and Gynecology, Mount Sinai Hospital, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- *Correspondence: Zhong-Cheng Luo,
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Sirtuin 6 inhibition protects against glucocorticoid-induced skeletal muscle atrophy by regulating IGF/PI3K/AKT signaling. Nat Commun 2022; 13:5415. [PMID: 36109503 PMCID: PMC9478160 DOI: 10.1038/s41467-022-32905-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/24/2022] [Indexed: 01/05/2023] Open
Abstract
Chronic activation of stress hormones such as glucocorticoids leads to skeletal muscle wasting in mammals. However, the molecular events that mediate glucocorticoid-induced muscle wasting are not well understood. Here, we show that SIRT6, a chromatin-associated deacetylase indirectly regulates glucocorticoid-induced muscle wasting by modulating IGF/PI3K/AKT signaling. Our results show that SIRT6 levels are increased during glucocorticoid-induced reduction of myotube size and during skeletal muscle atrophy in mice. Notably, overexpression of SIRT6 spontaneously decreases the size of primary myotubes in a cell-autonomous manner. On the other hand, SIRT6 depletion increases the diameter of myotubes and protects them against glucocorticoid-induced reduction in myotube size, which is associated with enhanced protein synthesis and repression of atrogenes. In line with this, we find that muscle-specific SIRT6 deficient mice are resistant to glucocorticoid-induced muscle wasting. Mechanistically, we find that SIRT6 deficiency hyperactivates IGF/PI3K/AKT signaling through c-Jun transcription factor-mediated increase in IGF2 expression. The increased activation, in turn, leads to nuclear exclusion and transcriptional repression of the FoxO transcription factor, a key activator of muscle atrophy. Further, we find that pharmacological inhibition of SIRT6 protects against glucocorticoid-induced muscle wasting in mice by regulating IGF/PI3K/AKT signaling implicating the role of SIRT6 in glucocorticoid-induced muscle atrophy.
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Ren Q, Li H, Xu F, Zhu Y, Zhang X, Fan T, Wei Z, Yuan F, Han F, Cong R. Effect of high-concentrate diets on mRNA expression of genes related to muscle fiber type and metabolism of psoas major muscle in goats. Anim Sci J 2022; 93:e13725. [PMID: 35508764 DOI: 10.1111/asj.13725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 03/14/2022] [Accepted: 04/01/2022] [Indexed: 11/27/2022]
Abstract
In the process of modern breeding, high-concentrate diets are widely used to meet the high energy nutritional requirements of animals but change the form of access to energy and nutrients and the way the organism metabolizes them. Goat psoas major (PM) muscle is a hybrid skeletal muscle whose characteristics are important for the motility and meat quality of goats. However, there are few studies on the effects of high-concentrate diets on the muscle type and metabolic characteristics of PM in goats. In this study, two treatment groups were set up: high concentrate group (HC) and control group (C). The expression of genes related to muscle type and metabolism of the PM was examined by quantitative PCR. The results showed that high concentrate promoted the conversion of PM fibers from intermediate to slow type at the mRNA level, improved the absorption, transport, and oxidation of fat by PM, and upregulated the expression of calpain system. These changes may be regulated by the involvement of differential expression of MSTN, Myf-5, and IGF-2. These results suggest that high concentrate may exert a positive effect on skeletal muscle function, metabolism, and meat quality in goats by affecting the expression of muscle type and metabolism-related genes.
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Affiliation(s)
- Qijun Ren
- Northwest A&F University, Xianyang, China
| | - Hanmei Li
- Northwest A&F University, Xianyang, China
| | | | - Yihan Zhu
- Northwest A&F University, Xianyang, China
| | | | | | | | | | - Fei Han
- Yangling Vocational & Technical College, Xianyang, China
| | - Rihua Cong
- Northwest A&F University, Xianyang, China
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4
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Song R, Wang Y, Zheng Q, Yao J, Cao C, Wang Y, Zhao J. One-step base editing in multiple genes by direct embryo injection for pig trait improvement. SCIENCE CHINA. LIFE SCIENCES 2022; 65:739-752. [PMID: 35060075 DOI: 10.1007/s11427-021-2013-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/17/2021] [Indexed: 10/19/2022]
Abstract
The precise and simultaneous acquisition of multiple beneficial alleles in the genome is in great demand for the development of elite pig breeders. Cytidine base editors (CBEs) that convert C:G to T:A have emerged as powerful tools for single-nucleotide replacement. Whether CBEs can effectively mediate C-to-T substitution at multiple sites/loci for trait improvement by direct zygote injection has not been verified in large animals. Here, we determined the editing efficiency of four CBE variants in porcine embryonic fibroblast cells and embryos. The findings showed that hA3A-BE3-Y130F and hA3A-eBE-Y130F consistently resulted in increased base-editing efficiency and low toxic effects in embryonic development. Further, we verified that using a one-step approach, direct zygote microinjection of the CBE system can generate pigs harboring multiple point mutations. Our process resulted in a stop codon in CD163 and myostatin (MSTN) and introduced a beneficial allele in insulin-like growth factor-2 (IGF2). The pigs showed disrupted expression of CD163 and MSTN and increased expression of IGF2, which significantly improved growth performance and infectious disease resistance. Our approach allows immediate introduction of multiple mutations in transgene-free animals to comprehensively improve economic traits through direct embryo microinjection, providing a potential new route to produce elite pig breeders.
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Affiliation(s)
- Ruigao Song
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,The Third Hospital of Shanxi Medical University, Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Taiyuan, 030032, China
| | - Yu Wang
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Qiantao Zheng
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jing Yao
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
| | - Chunwei Cao
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yanfang Wang
- State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Jianguo Zhao
- State Key Laboratory of Stem cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China. .,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China.
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Strobel JS, Hack NL, Label KT, Cordova KL, Bersin TV, Journey ML, Beckman BR, Lema SC. Effects of food deprivation on plasma insulin-like growth factor-1 (Igf1) and Igf binding protein (Igfbp) gene transcription in juvenile cabezon (Scorpaenichthys marmoratus). Gen Comp Endocrinol 2020; 286:113319. [PMID: 31715138 DOI: 10.1016/j.ygcen.2019.113319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/25/2019] [Accepted: 11/08/2019] [Indexed: 12/25/2022]
Abstract
The growth hormone (GH)/insulin-like growth factor (Igf) endocrine axis regulates somatic growth in the face of changing environmental conditions. In actinopterygian fishes, food availability is a key modulator of the somatotropic axis, with lower food intake generally depressing liver Igf1 release to diminish growth. Igf1 signaling, however, also involves several distinct IGF binding proteins (Igfbps), and the functional roles of many of these Igfbps in affecting growth during shifting food availability remain uncertain. Here, we tested how complete food deprivation (fasting) affected gene transcription for paralogs of all six types of Igfbps in the liver and fast-twitch skeletal muscle of cabezon (Scorpaenichthys marmoratus), a nearshore marine fish important for recreational fisheries in the eastern North Pacific Ocean. Juvenile cabezon were maintained as either fed (6% mass food⋅g fish wet mass-1⋅d-1) or fasted for 14 d. Fasted fish exhibited a lower body condition (K), a depressed mass-specific growth rate (SGR), and reduced plasma concentrations of Igf1. In the liver, fasting reduced the relative abundance of gene transcripts encoding Igfbps igfbp2a and igfbp2b, while significantly elevating mRNA levels for igfbp1a, igfbp1b, igfbp3b, and igfbp4. Fasting also reduced hepatic mRNA levels of GH receptor-1 (ghr1) - but not GH receptor-2 (ghr2) - supporting the idea that changes in liver sensitivity to GH may underlie the decline in plasma Igf1 during food deprivation. In skeletal muscle, fasting downregulated gene transcripts encoding igf1, igfbp2b, igfbp5b, and igfbp6b, while also upregulating mRNAs for igf2 and ghr2. These data demonstrate isoform-specific regulation of Igfbps in liver and skeletal muscle in cabezon experiencing food deprivation and reinforce the idea that the repertoire of duplicated Igfbp genes that evolved in actinopterygian fishes supports a diverse scope of endocrine and paracrine functions.
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Affiliation(s)
- Jackson S Strobel
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Nicole L Hack
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Kevin T Label
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Kasey L Cordova
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Theresa V Bersin
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - Meredith L Journey
- Lynker Technology, 202 Church St SE #536, Leesburg, VA 20175, Under Contract to Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle Washington 98112, USA
| | - Brian R Beckman
- Environmental and Fisheries Sciences Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington 98112, USA
| | - Sean C Lema
- Biological Sciences Department, Center for Coastal Marine Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
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Analysis of Anasplatyrhynchos genome resequencing data reveals genetic signatures of artificial selection. PLoS One 2019; 14:e0211908. [PMID: 30735526 PMCID: PMC6368380 DOI: 10.1371/journal.pone.0211908] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/22/2019] [Indexed: 02/05/2023] Open
Abstract
Three artificially selected duck populations (AS), higher lean meat ratios (LTPD), higher fat ratios (FTPD) and higher quality meat (CMD), have been developed in China, providing excellent populations for investigation of artificial selection effects. However, the genetic signatures of artificial selection are unclear. In this study, we sequenced the genome sequences of these three artificially selected populations and their ancestral population (mallard, M). We then compared the genome sequences between AS and M and between LTPD and FTPD using integrated strategies such as anchoring scaffolds to pseudo-chromosomes, mutation detection, selective screening, GO analysis, qRT-PCR, and protein multiple sequences alignment to uncover genetic signatures of selection. We anchored duck scaffolds to pseudo-chromosomes and obtained 28 pseudo-chromosomes, accounting for 84% of duck genome in length. Totally 78 and 99 genes were found to be under selection between AS and M and between LTPD and FTPD. Genes under selection between AS and M mainly involved in pigmentation and heart rates, while genes under selection between LTPD and FTPD involved in muscle development and fat deposition. A heart rate regulator (HCN1), the strongest selected gene between AS and M, harbored a GC deletion in AS and displayed higher mRNA expression level in M than in AS. IGF2R, a regulator of skeletal muscle mass, was found to be under selection between FTPD and LTPD. We also found two nonsynonymous substitutions in IGF2R, which might lead to higher IGF2R mRNA expression level in FTPD than LTPD, indicating the two nonsynonymous substitutions might play a key role for the regulation of duck skeletal muscle mass. Taken together, these results of this study provide valuable insight for the genetic basis of duck artificial selection.
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7
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Voluntary locomotor activity promotes myogenic growth potential in domestic pigs. Sci Rep 2018; 8:2533. [PMID: 29416067 PMCID: PMC5803246 DOI: 10.1038/s41598-018-20652-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 01/23/2018] [Indexed: 01/25/2023] Open
Abstract
Self-determined physical activity is an essential behavioural need and can vary considerably between individuals of a given species. Although locomotion is suggested as a prerequisite for adequate function of skeletal muscle, domestic pigs are usually reared under limited space allowance. The aim of our study was to investigate if a different voluntary locomotor activity leads to altered properties in the muscle structure, biochemistry and mRNA expression of selected genes involved in myogenesis and skeletal muscle metabolism. Based on a video tracking method, we assigned pigs to three categories according to their total distances walked over five observed time points: long distance, medium distance, and short distance. The microstructure and biochemistry parameters of the M. semitendinosus were unaffected by the distance categories. However, we found distance-dependent differences in the mRNA expression of the genes encoding growth (IGF2, EGF, MSTN) and transcription factors (MRF4, MYOD). In particular, the IGF2/MSTN ratio appears to be a sensitive indicator, at the molecular level, for the locomotor activity of individuals. Our results indicate that the myogenic growth potential of pigs under standard rearing conditions is triggered by their displayed voluntary locomotor activity, but the covered distances are insufficient to induce adaptive changes at the tissue level.
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Hennebry A, Oldham J, Shavlakadze T, Grounds MD, Sheard P, Fiorotto ML, Falconer S, Smith HK, Berry C, Jeanplong F, Bracegirdle J, Matthews K, Nicholas G, Senna-Salerno M, Watson T, McMahon CD. IGF1 stimulates greater muscle hypertrophy in the absence of myostatin in male mice. J Endocrinol 2017; 234:187-200. [PMID: 28533420 DOI: 10.1530/joe-17-0032] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Accepted: 05/22/2017] [Indexed: 01/02/2023]
Abstract
Insulin-like growth factors (IGFs) and myostatin have opposing roles in regulating the growth and size of skeletal muscle, with IGF1 stimulating, and myostatin inhibiting, growth. However, it remains unclear whether these proteins have mutually dependent, or independent, roles. To clarify this issue, we crossed myostatin null (Mstn-/-) mice with mice overexpressing Igf1 in skeletal muscle (Igf1+) to generate six genotypes of male mice; wild type (Mstn+/+ ), Mstn+/-, Mstn-/-, Mstn+/+:Igf1+, Mstn+/-:Igf1+ and Mstn-/-:Igf1+ Overexpression of Igf1 increased the mass of mixed fibre type muscles (e.g. Quadriceps femoris) by 19% over Mstn+/+ , 33% over Mstn+/- and 49% over Mstn-/- (P < 0.001). By contrast, the mass of the gonadal fat pad was correspondingly reduced with the removal of Mstn and addition of Igf1 Myostatin regulated the number, while IGF1 regulated the size of myofibres, and the deletion of Mstn and Igf1+ independently increased the proportion of fast type IIB myosin heavy chain isoforms in T. anterior (up to 10% each, P < 0.001). The abundance of AKT and rpS6 was increased in muscles of Mstn-/-mice, while phosphorylation of AKTS473 was increased in Igf1+mice (Mstn+/+:Igf1+, Mstn+/-:Igf1+ and Mstn-/-:Igf1+). Our results demonstrate that a greater than additive effect is observed on the growth of skeletal muscle and in the reduction of body fat when myostatin is absent and IGF1 is in excess. Finally, we show that myostatin and IGF1 regulate skeletal muscle size, myofibre type and gonadal fat through distinct mechanisms that involve increasing the total abundance and phosphorylation status of AKT and rpS6.
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Affiliation(s)
| | | | - Tea Shavlakadze
- School of AnatomyPhysiology & Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Miranda D Grounds
- School of AnatomyPhysiology & Human Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Philip Sheard
- Department of PhysiologyUniversity of Otago, Dunedin, New Zealand
| | - Marta L Fiorotto
- USDA/ARS Children's Nutrition Research CenterBaylor College of Medicine, Houston, Texas, USA
| | | | - Heather K Smith
- Department of Exercise SciencesUniversity of Auckland, Auckland, New Zealand
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Rader EP, Naimo MA, Ensey J, Baker BA. Agonist muscle adaptation accompanied by antagonist muscle atrophy in the hindlimb of mice following stretch-shortening contraction training. BMC Musculoskelet Disord 2017; 18:60. [PMID: 28148306 PMCID: PMC5288976 DOI: 10.1186/s12891-017-1397-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 01/11/2017] [Indexed: 02/26/2023] Open
Abstract
Background The vast majority of dynamometer-based animal models for investigation of the response to chronic muscle contraction exposure has been limited to analysis of isometric, lengthening, or shortening contractions in isolation. An exception to this has been the utilization of a rat model to study stretch-shortening contractions (SSCs), a sequence of consecutive isometric, lengthening, and shortening contractions common during daily activity and resistance-type exercise. However, the availability of diverse genetic strains of rats is limited. Therefore, the purpose of the present study was to develop a dynamometer-based SSC training protocol to induce increased muscle mass and performance in plantarflexor muscles of mice. Methods Young (3 months old) C57BL/6 mice were subjected to 1 month of plantarflexion SSC training. Hindlimb muscles were analyzed for muscle mass, quantitative morphology, myogenesis/myopathy relevant gene expression, and fiber type distribution. Results The main aim of the research was achieved when training induced a 2-fold increase in plantarflexion peak torque output and a 19% increase in muscle mass for the agonist plantaris (PLT) muscle. In establishing this model, several outcomes emerged which raised the value of the model past that of being a mere recapitulation of the rat model. An increase in the number of muscle fibers per transverse muscle section accounted for the PLT muscle mass gain while the antagonist tibialis anterior (TA) muscle atrophied by 30% with preferential atrophy of type IIb and IIx fibers. These alterations were accompanied by distinct gene expression profiles. Conclusions The findings confirm the development of a stretch-shortening contraction training model for the PLT muscle of mice and demonstrate that increased cross-sectional fiber number can occur following high-intensity SSC training. Furthermore, the TA muscle atrophy provides direct evidence for the concept of muscle imbalance in phasic non-weight bearing muscles, a concept largely characterized based on clinical observation of patients. The susceptibility to this imbalance is demonstrated to be selective for the type IIb and IIx muscle fiber types. Overall, the study highlights the importance of considering muscle fiber number modulation and the effect of training on surrounding muscles in exercise comprised of SSCs. Electronic supplementary material The online version of this article (doi:10.1186/s12891-017-1397-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Erik P Rader
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, MS L3014, 1095 Willowdale Rd, Morgantown, West Virginia, 26505, USA.
| | - Marshall A Naimo
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, MS L3014, 1095 Willowdale Rd, Morgantown, West Virginia, 26505, USA.,West Virginia University School of Medicine, Division of Exercise Physiology, Morgantown, West Virginia, USA
| | - James Ensey
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, MS L3014, 1095 Willowdale Rd, Morgantown, West Virginia, 26505, USA
| | - Brent A Baker
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, MS L3014, 1095 Willowdale Rd, Morgantown, West Virginia, 26505, USA
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Martinet C, Monnier P, Louault Y, Benard M, Gabory A, Dandolo L. H19 controls reactivation of the imprinted gene network during muscle regeneration. Development 2016; 143:962-71. [DOI: 10.1242/dev.131771] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The H19 locus controls fetal growth by regulating expression of several genes from the imprinted gene network (IGN). H19 is fully repressed after birth, except in skeletal muscle. Using loss-of-function H19Δ3 mice, we investigated the function of H19 in adult muscle. Mutant muscles display hypertrophy and hyperplasia, with increased Igf2 and decreased myostatin (Mstn) expression. Many imprinted genes are expressed in muscle stem cells or satellite cells. Unexpectedly, the number of satellite cells was reduced by 50% in H19Δ3 muscle fibers. This reduction occurred after postnatal day 21, suggesting a link with their entry into quiescence. We investigated the biological function of these mutant satellite cells in vivo using a regeneration assay induced by multiple injections of cardiotoxin. Surprisingly, despite their reduced number, the self-renewal capacity of these cells is fully retained in the absence of H19. In addition, we observed a better regeneration potential of the mutant muscles, with enhanced expression of several IGN genes and genes from the IGF pathway.
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Affiliation(s)
- Clémence Martinet
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
| | - Paul Monnier
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
| | - Yann Louault
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
| | - Matthieu Benard
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
| | - Anne Gabory
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
| | - Luisa Dandolo
- Institut Cochin, INSERM U1016, CNRS UMR 8104, University Paris Descartes, Paris 75014, France
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