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Lionikas A, Hernandez Cordero AI, Kilikevicius A, Carroll AM, Bewick GS, Bunger L, Ratkevicius A, Heisler LK, Harboe M, Oxvig C. Stanniocalcin-2 inhibits skeletal muscle growth and is upregulated in functional overload-induced hypertrophy. Physiol Rep 2023; 11:e15793. [PMID: 37568262 PMCID: PMC10510475 DOI: 10.14814/phy2.15793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/13/2023] Open
Abstract
AIMS Stanniocalcin-2 (STC2) has recently been implicated in human muscle mass variability by genetic analysis. Biochemically, STC2 inhibits the proteolytic activity of the metalloproteinase PAPP-A, which promotes muscle growth by upregulating the insulin-like growth factor (IGF) axis. The aim was to examine if STC2 affects skeletal muscle mass and to assess how the IGF axis mediates muscle hypertrophy induced by functional overload. METHODS We compared muscle mass and muscle fiber morphology between Stc2-/- (n = 21) and wild-type (n = 15) mice. We then quantified IGF1, IGF2, IGF binding proteins -4 and -5 (IGFBP-4, IGFBP-5), PAPP-A and STC2 in plantaris muscles of wild-type mice subjected to 4-week unilateral overload (n = 14). RESULTS Stc2-/- mice showed up to 10% larger muscle mass compared with wild-type mice. This increase was mediated by greater cross-sectional area of muscle fibers. Overload increased plantaris mass and components of the IGF axis, including quantities of IGF1 (by 2.41-fold, p = 0.0117), IGF2 (1.70-fold, p = 0.0461), IGFBP-4 (1.48-fold, p = 0.0268), PAPP-A (1.30-fold, p = 0.0154) and STC2 (1.28-fold, p = 0.019). CONCLUSION Here we provide evidence that STC2 is an inhibitor of muscle growth upregulated, along with other components of the IGF axis, during overload-induced muscle hypertrophy.
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Affiliation(s)
- Arimantas Lionikas
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Ana I. Hernandez Cordero
- Centre for Heart Lung InnovationUniversity of British Columbia, St. Paul's HospitalVancouverCanada
| | - Audrius Kilikevicius
- Department of Health Promotion and RehabilitationLithuanian Sports UniversityKaunasLithuania
| | - Andrew M. Carroll
- The New Zealand Institute for Plant & Food Research LimitedPalmerston NorthNew Zealand
| | - Guy S. Bewick
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Lutz Bunger
- Animal Genetics Company (AnGeCo)EdinburghScotland
| | - Aivaras Ratkevicius
- Department of Health Promotion and RehabilitationLithuanian Sports UniversityKaunasLithuania
| | - Lora K. Heisler
- School of Medicine, Medical Sciences and NutritionUniversity of AberdeenAberdeenUK
| | - Mette Harboe
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Claus Oxvig
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
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2
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Zou J, Gopalakrishnan S, Parker CC, Nicod J, Mott R, Cai N, Lionikas A, Davies RW, Palmer AA, Flint J. Analysis of independent cohorts of outbred CFW mice reveals novel loci for behavioral and physiological traits and identifies factors determining reproducibility. G3 (BETHESDA, MD.) 2022; 12:jkab394. [PMID: 34791208 PMCID: PMC8728023 DOI: 10.1093/g3journal/jkab394] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 10/17/2021] [Indexed: 12/12/2022]
Abstract
Combining samples for genetic association is standard practice in human genetic analysis of complex traits, but is rarely undertaken in rodent genetics. Here, using 23 phenotypes and genotypes from two independent laboratories, we obtained a sample size of 3076 commercially available outbred mice and identified 70 loci, more than double the number of loci identified in the component studies. Fine-mapping in the combined sample reduced the number of likely causal variants, with a median reduction in set size of 51%, and indicated novel gene associations, including Pnpo, Ttll6, and GM11545 with bone mineral density, and Psmb9 with weight. However, replication at a nominal threshold of 0.05 between the two component studies was low, with less than one-third of loci identified in one study replicated in the second. In addition to overestimates in the effect size in the discovery sample (Winner's Curse), we also found that heterogeneity between studies explained the poor replication, but the contribution of these two factors varied among traits. Leveraging these observations, we integrated information about replication rates, study-specific heterogeneity, and Winner's Curse corrected estimates of power to assign variants to one of four confidence levels. Our approach addresses concerns about reproducibility and demonstrates how to obtain robust results from mapping complex traits in any genome-wide association study.
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Affiliation(s)
- Jennifer Zou
- Department of Computer Science, University of California, Los Angeles, CA 90024, USA
| | - Shyam Gopalakrishnan
- Faculty of Health and Medical Sciences, GLOBE Institute, University of Copenhagen, Copenhagen DK-1353, Denmark
| | - Clarissa C Parker
- Department of Psychology and Program in Neuroscience, Middlebury College, Middlebury, VT 05753, USA
| | | | - Richard Mott
- UCL Department of Genetics, Evolution & Environment, UCL Genetics Institute, London WC1E 6BT, UK
| | - Na Cai
- Helmholtz Zentrum Muenchen, Helmoltz Pioneer Campus, Neuherberg 85764, Germany
| | - Arimantas Lionikas
- School of Medicine, Medical Sciences and Nutrition, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen AB24 3FX, UK
| | - Robert W Davies
- Department of Statistics, University of Oxford, Oxford OX1 2JD, UK
| | - Abraham A Palmer
- Department of Psychiatry, University of California San Diego, La Jolla, CA 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA 92093, USA
| | - Jonathan Flint
- Department of Biobehavioral Sciences, University of California, Los Angeles, CA 90024, USA
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3
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Lapinskas E, Krusnauskas R, Cekanauskaite A, Ratkevicius A. Effect of fasting on body composition and proteolysis gene expression in skeletal muscles and liver of BEH+/+ and BEL mice. Growth Factors 2020; 38:259-268. [PMID: 34355624 DOI: 10.1080/08977194.2021.1960831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Fasting improves health, but can cause muscle weakness. We assessed body composition in 21-week old males of Berlin high (BEH+/+) and Berlin low (BEL) strains after two bouts of 48-h or 40-h of fasting with 5-day refeeding in between, respectively. BEH+/+ mice tended to loose less weight than BEL in bout 1 and 2 (16.0 ± 2.7 versus 23.5 ± 2.9%, p < 0.001 and 17.1 ± 3.4 versus 20.4 ± 3.4%, p = 0.17, respectively). In spite of greater serum IGF-1 and body fat levels, BEH+/+ mice showed more severe muscle atrophy, but less marked liver wasting and fat depletion than BEL mice. BEH+/+ mice also showed smaller increases in expression of p62, Atrogin-1, and Mstn genes in skeletal muscles. In summary, BEL mice show resistance to fasting-induced muscle wasting in spite of low serum IGF-1 levels and high expression of genes associated with muscle atrophy.
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Affiliation(s)
- Edgaras Lapinskas
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania
| | - Raulas Krusnauskas
- Institute of Sports Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Agne Cekanauskaite
- Institute of Sports Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Aivaras Ratkevicius
- Department of Health Promotion and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania
- Institute of Sports Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
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4
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Hendrickse PW, Krusnauskas R, Hodson-Tole E, Venckunas T, Degens H. Endurance exercise plus overload induces fatigue resistance and similar hypertrophy in mice irrespective of muscle mass. Exp Physiol 2020; 105:2110-2122. [PMID: 33140456 DOI: 10.1113/ep089096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 10/28/2020] [Indexed: 12/29/2022]
Abstract
NEW FINDINGS What is the central question of this study? Does combining endurance and hypertrophic stimuli blunt the adaptations to both modalities and is this effect greater in muscles with larger baseline fibre cross sectional area? What is the main finding and its importance? Endurance exercise and hypertrophic stimuli can be combined to increase fatigue resistance and fibre size without blunting either adaptation regardless of baseline fibre size. ABSTRACT Previous studies have demonstrated that fibre cross-sectional area (FCSA) is inversely related to oxidative capacity, which is thought to be determined by diffusion limitations of oxygen, ADP and ATP. Consequently, it is hypothesised that (1) when endurance training is combined with a hypertrophic stimulus the response to each will be blunted, and (2) muscles with a smaller FCSA will show a larger hypertrophic response than those with a large FCSA. To investigate this, we combined overload with endurance exercise in 12-month-old male mice from three different strains with different FCSA: Berlin High (BEH) (large fibres), C57BL/6J (C57) (normal-sized fibres) and Berlin Low (BEL) (small fibres). The right plantaris muscle was subjected to overload through denervation of synergists with the left muscle acting as an internal control. Half the animals trained 30 min per day for 6 weeks. The overload-induced hypertrophy was not blunted by endurance exercise, and the exercise-induced increase in fatigue resistance was not impaired by overload. All strains demonstrated similar absolute increases in FCSA, although the BEH mice with more fibres than the C57 mice demonstrated the largest increase in muscle mass and BEL mice with fewer fibres the smallest increase in muscle mass. This study suggests that endurance exercise and hypertrophic stimuli can be combined without attenuating adaptations to either modality, and that increases in FCSA are independent of baseline fibre size.
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Affiliation(s)
- Paul W Hendrickse
- Department of Life Sciences, Research Centre for Musculoskeletal Science & Sports Medicine, Manchester Metropolitan University, Manchester, UK.,Lithuanian Sports University, Kaunas, Lithuania
| | | | - Emma Hodson-Tole
- Department of Life Sciences, Research Centre for Musculoskeletal Science & Sports Medicine, Manchester Metropolitan University, Manchester, UK
| | | | - Hans Degens
- Department of Life Sciences, Research Centre for Musculoskeletal Science & Sports Medicine, Manchester Metropolitan University, Manchester, UK.,Lithuanian Sports University, Kaunas, Lithuania
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5
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Myostatin dysfunction is associated with lower physical activity and reduced improvements in glucose tolerance in response to caloric restriction in Berlin high mice. Exp Gerontol 2019; 128:110751. [DOI: 10.1016/j.exger.2019.110751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 10/06/2019] [Accepted: 10/13/2019] [Indexed: 12/16/2022]
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6
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Fokin A, Minderis P, Venckunas T, Lionikas A, Kvedaras M, Ratkevicius A. Myostatin dysfunction does not protect from fasting-induced loss of muscle mass in mice. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2019; 19:342-353. [PMID: 31475942 PMCID: PMC6737554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The aim of the study was to investigate if myostatin dysfunction can ameliorate fasting-induced muscle wasting. METHODS 18-week old males from Berlin high (BEH) strain with myostatin dysfunction and wild type myostatin (BEH+/+) strain were subjected to 48-h food deprivation (FD). Changes in body composition as well as contractile properties of soleus (SOL) and extensor digitorum longus (EDL) muscles were studied. RESULTS BEH mice were heavier than BEH+/+ mice (56.0±2.5 vs. 49.9±2.8 g, P<0.001, respectively). FD induced similar loss of body mass in BEH and BEH+/+ mice (16.6±2.4 vs. 17.4±2.2%, P>0.05), but only BEH mice experienced wasting of the gastrocnemius, tibialis anterior and plantaris muscles. FD induced a marked decrease in specific muscle force of SOL. EDL of BEH mice tended to be protected from this decline. CONCLUSION Myostatin dysfunction does not protect from loss of muscle mass during fasting.
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Affiliation(s)
- Andrej Fokin
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Petras Minderis
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Tomas Venckunas
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania,Department of Applied Biology and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania
| | - Arimantas Lionikas
- School of Medicine, Medical Sciences and Nutrition, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, Scotland, UK
| | - Mindaugas Kvedaras
- Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania
| | - Aivaras Ratkevicius
- Department of Applied Biology and Rehabilitation, Lithuanian Sports University, Kaunas, Lithuania,Corresponding author: Dr. Aivaras Ratkevicius, Department of Applied Biology and Rehabilitation, Lithuanian Sports University, Sporto g. 6, LT-44221 Kaunas, Lithuania E-mail:
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7
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Satkunskiene D, Ratkevicius A, Kamandulis S, Venckunas T. Effects of myostatin on the mechanical properties of muscles during repeated active lengthening in the mouse. Appl Physiol Nutr Metab 2018; 44:381-388. [PMID: 30222937 DOI: 10.1139/apnm-2018-0369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of the present study was to investigate how myostatin dysfunction affects fast and slow muscle stiffness and viscosity during severe repeated loading. Isolated extensor digitorum longus (EDL) and soleus muscles of young adult female mice of the BEH (dysfunctional myostatin) and BEH+/+ (functional myostatin) strains were subjected to 100 contraction-stretching loading cycles during which contractile and mechanical properties were assessed. BEH mice exhibited greater exercise-induced muscle damage, although the effect was muscle- and age-dependent and limited to the early phases of simulated exercise. The relative reduction of the EDL muscle isometric force recorded during the initial 10-30 loading cycles was greater in BEH mice than in BEH+/+ mice and exceeded that of the soleus muscle of either strain. The induced damage was associated with lower muscle stiffness. The effects of myostatin on the mechanical properties of muscles depend on muscle type and maturity.
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Affiliation(s)
- Danguole Satkunskiene
- Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania.,Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| | - Aivaras Ratkevicius
- Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania.,Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| | - Sigitas Kamandulis
- Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania.,Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
| | - Tomas Venckunas
- Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania.,Institute of Sports Science and Innovation, Lithuanian Sports University, Kaunas, Lithuania
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8
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Kilikevicius A, Bunger L, Lionikas A. Baseline Muscle Mass Is a Poor Predictor of Functional Overload-Induced Gain in the Mouse Model. Front Physiol 2016; 7:534. [PMID: 27895593 PMCID: PMC5108802 DOI: 10.3389/fphys.2016.00534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic background contributes substantially to individual variability in muscle mass. Muscle hypertrophy in response to resistance training can also vary extensively. However, it is less clear if muscle mass at baseline is predictive of the hypertrophic response. The aim of this study was to examine the effect of genetic background on variability in muscle mass at baseline and in the adaptive response of the mouse fast- and slow-twitch muscles to overload. Males of eight laboratory mouse strains: C57BL/6J (B6, n = 17), BALB/cByJ (n = 7), DBA/2J (D2, n = 12), B6.A-(rs3676616-D10Utsw1)/Kjn (B6.A, n = 9), C57BL/6J-Chr10A/J/NaJ (B6.A10, n = 8), BEH+/+ (n = 11), BEH (n = 12), and DUHi (n = 12), were studied. Compensatory growth of soleus and plantaris muscles was triggered by a 4-week overload induced by synergist unilateral ablation. Muscle weight in the control leg (baseline) varied from 5.2 ± 07 mg soleus and 11.4 ± 1.3 mg plantaris in D2 mice to 18.0 ± 1.7 mg soleus in DUHi and 43.7 ± 2.6 mg plantaris in BEH (p < 0.001 for both muscles). In addition, soleus in the B6.A10 strain was ~40% larger (p < 0.001) compared to the B6. Functional overload increased muscle weight, however, the extent of gain was strain-dependent for both soleus (p < 0.01) and plantaris (p < 0.02) even after accounting for the baseline differences. For the soleus muscle, the BEH strain emerged as the least responsive, with a 1.3-fold increase, compared to a 1.7-fold gain in the most responsive D2 strain, and there was no difference in the gain between the B6.A10 and B6 strains. The BEH strain appeared the least responsive in the gain of plantaris as well, 1.3-fold, compared to ~1.5-fold gain in the remaining strains. We conclude that variation in muscle mass at baseline is not a reliable predictor of that in the overload-induced gain. This suggests that a different set of genes influence variability in muscle mass acquired in the process of normal development, growth, and maintenance, and in the process of adaptive growth of the muscle challenged by overload.
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Affiliation(s)
- Audrius Kilikevicius
- Institute of Sport Science and Innovations, Lithuanian Sports University Kaunas, Lithuania
| | - Lutz Bunger
- Animal & Veterinary Sciences, Scotland's Rural College, Roslin Institute Building Midlothian, UK
| | - Arimantas Lionikas
- School of Medicine, Medical Sciences and Nutrition, College of Life Sciences and Medicine, University of Aberdeen Aberdeen, UK
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9
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Sharma AK, Morrison JP, Rao DB, Pardo ID, Garman RH, Bolon B. Toxicologic Pathology Analysis for Translational Neuroscience. Int J Toxicol 2016; 35:410-9. [DOI: 10.1177/1091581816636372] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A half-day American College of Toxicology continuing education course presented key issues often confronted by translational neuroscientists when predicting human risk from animal-derived toxicologic pathology data. Two talks correlated discrete structures with major functions in brains of rodents and nonrodents. The third lecture provided practical advice to obtain highly homologous rodent brain sections for quantitative morphometry in developmental neurotoxicity testing. The last presentation discussed demographic influences (eg, species, strain, sex, age), physiological attributes (eg, body composition, brain vascularity, pharmacokinetic/pharmacodynamic patterns, etc), and husbandry parameters (eg, group housing) recognized to impact the actions of neuroactive chemicals. Speakers described common cases of real-world challenges to animal data interpretation encountered when designing studies or extrapolating biological responses across species. The efficiency of translational neuroscience efforts will likely be enhanced as new methods (eg, high-resolution non-invasive imaging) improve our capability to cross-connect subtle anatomic and/or biochemical lesions with functional changes over time.
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Affiliation(s)
| | | | - Deepa B. Rao
- Center for Drug Evaluation and Research (CDER), US Food and Drug Administration, Silver Spring, MD, USA
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10
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Minderis P, Kilikevicius A, Baltusnikas J, Alhindi Y, Venckunas T, Bunger L, Lionikas A, Ratkevicius A. Myostatin dysfunction is associated with reduction in overload induced hypertrophy of soleus muscle in mice. Scand J Med Sci Sports 2015; 26:894-901. [DOI: 10.1111/sms.12532] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2015] [Indexed: 12/16/2022]
Affiliation(s)
- P. Minderis
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
| | - A. Kilikevicius
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
| | - J. Baltusnikas
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
| | - Y. Alhindi
- School of Medical Sciences; College of Life Sciences and Medicine; University of Aberdeen; Aberdeen Scotland UK
| | - T. Venckunas
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
| | - L. Bunger
- Animal Breeding and Genetics, Animal and Veterinary Sciences group; Scotland's Rural College (SRUC); Edinburgh UK
| | - A. Lionikas
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
- School of Medical Sciences; College of Life Sciences and Medicine; University of Aberdeen; Aberdeen Scotland UK
| | - A. Ratkevicius
- Institute of Sport Science and Innovations; Lithuanian Sports University; Kaunas Lithuania
- School of Medical Sciences; College of Life Sciences and Medicine; University of Aberdeen; Aberdeen Scotland UK
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11
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Baltusnikas J, Kilikevicius A, Venckunas T, Fokin A, Bünger L, Lionikas A, Ratkevicius A. Myostatin dysfunction impairs force generation in extensor digitorum longus muscle and increases exercise-induced protein efflux from extensor digitorum longus and soleus muscles. Appl Physiol Nutr Metab 2015. [DOI: 10.1139/apnm-2014-0513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Myostatin dysfunction promotes muscle hypertrophy, which can complicate assessment of muscle properties. We examined force generating capacity and creatine kinase (CK) efflux from skeletal muscles of young mice before they reach adult body and muscle size. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of Berlin high (BEH) mice with dysfunctional myostatin, i.e., homozygous for inactivating myostatin mutation, and with a wild-type myostatin (BEH+/+) were studied. The muscles of BEH mice showed faster (P < 0.01) twitch and tetanus contraction times compared with BEH+/+ mice, but only EDL displayed lower (P < 0.05) specific force. SOL and EDL of age-matched but not younger BEH mice showed greater exercise-induced CK efflux compared with BEH+/+ mice. In summary, myostatin dysfunction leads to impairment in muscle force generating capacity in EDL and increases susceptibility of SOL and EDL to protein loss after exercise.
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Affiliation(s)
- Juozas Baltusnikas
- Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221, Kaunas, Lithuania
| | - Audrius Kilikevicius
- Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221, Kaunas, Lithuania
| | - Tomas Venckunas
- Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221, Kaunas, Lithuania
| | - Andrej Fokin
- Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221, Kaunas, Lithuania
| | - Lutz Bünger
- Scotland’s Rural College (SRUC), Edinburgh, UK
| | - Arimantas Lionikas
- School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, Scotland, UK
| | - Aivaras Ratkevicius
- Institute of Sports Sciences and Innovation, Lithuanian Sports University, Sporto 6, LT-44221, Kaunas, Lithuania
- School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, Scotland, UK
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12
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Morrison JP, Sharma AK, Rao D, Pardo ID, Garman RH, Kaufmann W, Bolon B. Fundamentals of translational neuroscience in toxicologic pathology: optimizing the value of animal data for human risk assessment. Toxicol Pathol 2014; 43:132-9. [PMID: 25398755 DOI: 10.1177/0192623314558306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A half-day Society of Toxicologic Pathology continuing education course on "Fundamentals of Translational Neuroscience in Toxicologic Pathology" presented some current major issues faced when extrapolating animal data regarding potential neurological consequences to assess potential human outcomes. Two talks reviewed functional-structural correlates in rodent and nonrodent mammalian brains needed to predict behavioral consequences of morphologic changes in discrete neural cell populations. The third lecture described practical steps for ensuring that specimens from rodent developmental neurotoxicity tests will be processed correctly to produce highly homologous sections. The fourth talk detailed demographic factors (e.g., species, strain, sex, and age); physiological traits (body composition, brain circulation, pharmacokinetic/pharmacodynamic patterns, etc.); and husbandry influences (e.g., group housing) known to alter the effects of neuroactive agents. The last presentation discussed the appearance, unknown functional effects, and potential relevance to humans of polyethylene glycol (PEG)-associated vacuoles within the choroid plexus epithelium of animals. Speakers provided real-world examples of challenges with data extrapolation among species or with study design considerations that may impact the interpretability of results. Translational neuroscience will be bolstered in the future as less invasive and/or more quantitative techniques are devised for linking overt functional deficits to subtle anatomic and chemical lesions.
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Affiliation(s)
| | | | - Deepa Rao
- National Toxicology Program, National Institute of Environmental Health Sciences and Integrated Laboratory Systems, Research Triangle Park, North Carolina, USA
| | | | - Robert H Garman
- Consultants in Veterinary Pathology, Inc., Murrysville, Pennsylvania, USA
| | | | - Brad Bolon
- The Ohio State University, College of Veterinary Medicine, Columbus, Ohio, USA
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13
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Carbonetto P, Cheng R, Gyekis JP, Parker CC, Blizard DA, Palmer AA, Lionikas A. Discovery and refinement of muscle weight QTLs in B6 × D2 advanced intercross mice. Physiol Genomics 2014; 46:571-82. [PMID: 24963006 DOI: 10.1152/physiolgenomics.00055.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The genes underlying variation in skeletal muscle mass are poorly understood. Although many quantitative trait loci (QTLs) have been mapped in crosses of mouse strains, the limited resolution inherent in these conventional studies has made it difficult to reliably pinpoint the causal genetic variants. The accumulated recombination events in an advanced intercross line (AIL), in which mice from two inbred strains are mated at random for several generations, can improve mapping resolution. We demonstrate these advancements in mapping QTLs for hindlimb muscle weights in an AIL (n = 832) of the C57BL/6J (B6) and DBA/2J (D2) strains, generations F8-F13. We mapped muscle weight QTLs using the high-density MegaMUGA SNP panel. The QTLs highlight the shared genetic architecture of four hindlimb muscles and suggest that the genetic contributions to muscle variation are substantially different in males and females, at least in the B6D2 lineage. Out of the 15 muscle weight QTLs identified in the AIL, nine overlapped the genomic regions discovered in an earlier B6D2 F2 intercross. Mapping resolution, however, was substantially improved in our study to a median QTL interval of 12.5 Mb. Subsequent sequence analysis of the QTL regions revealed 20 genes with nonsense or potentially damaging missense mutations. Further refinement of the muscle weight QTLs using additional functional information, such as gene expression differences between alleles, will be important for discerning the causal genes.
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Affiliation(s)
| | - R Cheng
- Australian National University, Canberra, Australia
| | - J P Gyekis
- Pennsylvania State University, State College, Pennsylvania; and
| | | | - D A Blizard
- Pennsylvania State University, State College, Pennsylvania; and
| | - A A Palmer
- University of Chicago, Chicago, Illinois
| | - A Lionikas
- University of Aberdeen, Aberdeen, United Kingdom;
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