1
|
Ronca F, Raggi A. Role of the interaction between troponin T and AMP deaminase by zinc bridge in modulating muscle contraction and ammonia production. Mol Cell Biochem 2024; 479:793-809. [PMID: 37184757 PMCID: PMC11016001 DOI: 10.1007/s11010-023-04763-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 05/06/2023] [Indexed: 05/16/2023]
Abstract
The N-terminal region of troponin T (TnT) does not bind any protein of the contractile machinery and the role of its hypervariability remains uncertain. In this review we report the evidence of the interaction between TnT and AMP deaminase (AMPD), a regulated zinc enzyme localized on the myofibril. In periods of intense muscular activity, a decrease in the ATP/ADP ratio, together with a decrease in the tissue pH, is the stimulus for the activation of the enzyme that deaminating AMP to IMP and NH3 displaces the myokinase reaction towards the formation of ATP. In skeletal muscle subjected to strong tetanic contractions, a calpain-like proteolytic activity produces the removal in vivo of a 97-residue N-terminal fragment from the enzyme that becomes desensitized towards the inhibition by ATP, leading to an unrestrained production of NH3. When a 95-residue N-terminal fragment is removed from AMPD by trypsin, simulating in vitro the calpain action, rabbit fast TnT or its phosphorylated 50-residue N-terminal peptide binds AMPD restoring the inhibition by ATP. Taking in consideration that the N-terminus of TnT expressed in human as well as rabbit white muscle contains a zinc-binding motif, we suggest that TnT might mimic the regulatory action of the inhibitory N-terminal domain of AMPD due to the presence of a zinc ion connecting the N-terminal and C-terminal regions of the enzyme, indicating that the two proteins might physiologically associate to modulate muscle contraction and ammonia production in fast-twitching muscle under strenuous conditions.
Collapse
Affiliation(s)
- Francesca Ronca
- Laboratory of Biochemistry, Department of Pathology, University of Pisa, Via Roma 55, 56126, Pisa, Italy.
| | - Antonio Raggi
- Laboratory of Biochemistry, Department of Pathology, University of Pisa, Via Roma 55, 56126, Pisa, Italy
| |
Collapse
|
2
|
Li Z, Yi C, Chen C, Liu C, Zhang S, Li S, Gao D, Cheng L, Zhang X, Sun J, He Y, Xu P. Predicting individual muscle fatigue tolerance by resting-state EEG brain network. J Neural Eng 2022; 19. [PMID: 35901723 DOI: 10.1088/1741-2552/ac8502] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 07/28/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Exercise-induced muscle fatigue is a complex physiological phenomenon involving the central and peripheral nervous systems, and fatigue tolerance varies across individuals. Various studies have emphasized the close relationships between muscle fatigue and the brain. However, the relationships between the resting-state electroencephalogram (rsEEG) brain network and individual muscle fatigue tolerance remain unexplored. APPROACH Eighteen elite water polo athletes took part in our experiment. Five-minute before- and after-fatigue-exercise rsEEG and fatiguing task (i.e., elbow flexion and extension) electromyography (EMG) data were recorded. Based on the graph theory, we constructed the before- and after-task rsEEG coherence network and compared the network differences between them. Then, the correlation between the before-fatigue rsEEG network properties and the EMG fatigue indexes when a subject cannot keep on exercising anymore was profiled. Finally, a prediction model based on the before-fatigue rsEEG network properties was established to predict fatigue tolerance. MAIN RESULTS Results of this study revealed the significant differences between the before- and after-exercise rsEEG brain network and found significant high correlations between before-exercise rsEEG network properties in the beta band and individual muscle fatigue tolerance. Finally, an efficient support vector regression (SVR) model based on the before-exercise rsEEG network properties in the beta band was constructed and achieved the accurate prediction of individual fatigue tolerance. Similar results were also revealed on another thirty-subject swimmer data set further demonstrating the reliability of predicting fatigue tolerance based on the rsEEG network. SIGNIFICANCE Our study investigates the relationship between the rsEEG brain network and individual muscle fatigue tolerance and provides a potential objective physiological biomarker for tolerance prediction and the regulation of muscle fatigue.
Collapse
Affiliation(s)
- Zhiwei Li
- Chengdu Sport University, No.2, Tiyuan Road, Wuhou District, Chengdu, 610041, CHINA
| | - Chanlin Yi
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| | - Chunli Chen
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| | - Chen Liu
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| | - Shu Zhang
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| | - Shunchang Li
- Chengdu Sport University, No.2, Tiyuan Road, Wuhou District, Chengdu, 610041, CHINA
| | - Dongrui Gao
- Chengdu University of Information Technology, No.24 Block 1, Xuefu Road, Chengdu, Sichuan, 610225, CHINA
| | - Liang Cheng
- Chengdu Sport University, No.2, Tiyuan Road, Wuhou District, Chengdu, 610041, CHINA
| | - Xiabing Zhang
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| | - Junzhi Sun
- Chengdu Sport University, No.2, Tiyuan Road, Wuhou District, Chengdu, 610041, CHINA
| | - Ying He
- Small Ball Department of Physical Education and Sport Sciences, Chengdu Sport University, No.2, Tiyuan Road, Wuhou District, Chengdu, 610041, CHINA
| | - Peng Xu
- University of Electronic Science and Technology of China, No.2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu, 611731, CHINA
| |
Collapse
|
3
|
Dang Y, Dong Q, Wu B, Yang S, Sun J, Cui G, Xu W, Zhao M, Zhang Y, Li P, Li L. Global Landscape of m6A Methylation of Differently Expressed Genes in Muscle Tissue of Liaoyu White Cattle and Simmental Cattle. Front Cell Dev Biol 2022; 10:840513. [PMID: 35359442 PMCID: PMC8960853 DOI: 10.3389/fcell.2022.840513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/22/2022] [Indexed: 12/13/2022] Open
Abstract
Liaoyu white cattle (LYWC) is a local breed in Liaoning Province, China. It has the advantages of grow quickly, high slaughter ratew, high meat quality and strong anti-stress ability. N6 methyladenosine (m6A) is a methylation modification of N6 position of RNA adenine, which is an important modification mechanism affecting physiological phenomena. In this study, we used the longissimus dorsi muscle of LYWC and SIMC for m6A-seq and RNA-seq high-throughput sequencing, and identified the key genes involved in muscle growth and m6A modification development by bioinformatics analysis. There were 31532 m6A peaks in the whole genome of LYWC and 47217 m6A peaks in the whole genome of SIMC. Compared with Simmental cattle group, LYWC group had 17,351 differentially expressed genes: 10,697 genes were up-regulated, 6,654 genes were down regulated, 620 differentially expressed genes were significant, while 16,731 differentially expressed genes were not significant. Among the 620 significantly differentially expressed genes, 295 genes were up-regulated and 325 genes were down regulated. In order to explore the relationship between m6A and mRNA expression in the muscles of LYWC and SIMC, the combined analysis of MeRIP-seq and RNA-seq revealed that 316 genes were m6A modified with mRNA expression. To identify differentially methylated genes related to muscle growth, four related genes were selected for quantitative verification in LYWC and SIMC. GO enrichment and KEGG analysis showed that the differentially expressed genes modified by m6A are mainly involved in skeletal muscle contraction, steroid biosynthesis process, redox process, PPAR pathway and fatty acid metabolism, and galactose metabolism. These results provide a theoretical basis for further research on the role of m6A in muscle growth and development.
Collapse
Affiliation(s)
- Yunlong Dang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Qiao Dong
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Bowei Wu
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Shuhua Yang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Jiaming Sun
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Gengyuan Cui
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Weixiang Xu
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Meiling Zhao
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Yunxuan Zhang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Peng Li
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
- *Correspondence: Peng Li, ; Lin Li,
| | - Lin Li
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
- Key Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Beijing, China
- *Correspondence: Peng Li, ; Lin Li,
| |
Collapse
|
4
|
Clayton JS, McNamara EL, Goullee H, Conijn S, Muthsam K, Musk GC, Coote D, Kijas J, Testa AC, Taylor RL, O’Hara AJ, Groth D, Ottenheijm C, Ravenscroft G, Laing NG, Nowak KJ. Ovine congenital progressive muscular dystrophy (OCPMD) is a model of TNNT1 congenital myopathy. Acta Neuropathol Commun 2020; 8:142. [PMID: 32819427 PMCID: PMC7441672 DOI: 10.1186/s40478-020-01017-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Ovine congenital progressive muscular dystrophy (OCPMD) was first described in Merino sheep flocks in Queensland and Western Australia in the 1960s and 1970s. The most prominent feature of the disease is a distinctive gait with stiffness of the hind limbs that can be seen as early as 3 weeks after birth. The disease is progressive. Histopathological examination had revealed dystrophic changes specifically in type I (slow) myofibres, while electron microscopy had demonstrated abundant nemaline bodies. Therefore, it was never certain whether the disease was a dystrophy or a congenital myopathy with dystrophic features. In this study, we performed whole genome sequencing of OCPMD sheep and identified a single base deletion at the splice donor site (+ 1) of intron 13 in the type I myofibre-specific TNNT1 gene (KT218690 c.614 + 1delG). All affected sheep were homozygous for this variant. Examination of TNNT1 splicing by RT-PCR showed intron retention and premature termination, which disrupts the highly conserved 14 amino acid C-terminus. The variant did not reduce TNNT1 protein levels or affect its localization but impaired its ability to modulate muscle contraction in response to Ca2+ levels. Identification of the causative variant in TNNT1 finally clarifies that the OCPMD sheep is in fact a large animal model of TNNT1 congenital myopathy. This model could now be used for testing molecular or gene therapies.
Collapse
Affiliation(s)
- Joshua S. Clayton
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Elyshia L. McNamara
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Hayley Goullee
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Stefan Conijn
- Department of Physiology, Amsterdam University Medical Center (Location VUmc), Amsterdam, Netherlands
| | - Keren Muthsam
- Animal Care Services, University of Western Australia, Nedlands, 6009 WA Australia
| | - Gabrielle C. Musk
- Animal Care Services, University of Western Australia, Nedlands, 6009 WA Australia
| | - David Coote
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - James Kijas
- Commonwealth Scientific and Industrial Research Organisation Agriculture and Food, Queensland Bioscience Precinct, Brisbane, 4067 QLD Australia
| | - Alison C. Testa
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Rhonda L. Taylor
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
- Faculty of Health and Medical Sciences, School of Biomedical Sciences, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Amanda J. O’Hara
- School of Veterinary Medicine, Murdoch University, Murdoch, 6150 WA Australia
| | - David Groth
- School of Pharmacy and Biomedical Sciences, CHIRI Biosciences Research Precinct, Curtin University, Bentley, 6102 WA Australia
| | - Coen Ottenheijm
- Department of Physiology, Amsterdam University Medical Center (Location VUmc), Amsterdam, Netherlands
| | - Gianina Ravenscroft
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Nigel G. Laing
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
| | - Kristen J. Nowak
- Harry Perkins Institute of Medical Research, Queen Elizabeth II Medical Centre, Nedlands, 6009 WA Australia
- Centre for Medical Research, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
- Faculty of Health and Medical Sciences, School of Biomedical Sciences, Queen Elizabeth II Medical Centre, University of Western Australia, Nedlands, 6009 WA Australia
- Office of Population Health Genomics, Public and Aboriginal Health Division, Western Australian Department of Health, East Perth, 6004 WA Australia
| |
Collapse
|
5
|
Oki K, Wei B, Feng HZ, Jin JP. The loss of slow skeletal muscle isoform of troponin T in spindle intrafusal fibres explains the pathophysiology of Amish nemaline myopathy. J Physiol 2019; 597:3999-4012. [PMID: 31148174 PMCID: PMC6675633 DOI: 10.1113/jp278119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/29/2019] [Indexed: 01/17/2023] Open
Abstract
KEY POINTS The pathogenic mechanism and the neuromuscular reflex-related phenotype (e.g. tremors accompanied by clonus) of Amish nemaline myopathy, as well as of other recessively inherited TNNT1 myopathies, remain to be clarified. The truncated slow skeletal muscle isoform of troponin T (ssTnT) encoded by the mutant TNNT1 gene is unable to incorporate into myofilaments and is degraded in muscle cells. By contrast to extrafusal muscle fibres, spindle intrafusal fibres of normal mice contain a significant level of cardiac TnT and a low molecular weight splice form of ssTnT. Intrafusal fibres of ssTnT-knockout mice have significantly increased cardiac TnT. Rotarod and balance beam tests have revealed abnormal neuromuscular co-ordination in ssTnT-knockout mice and a blunted response to a spindle sensitizer, succinylcholine. The loss of ssTnT and a compensatory increase of cardiac TnT in intrafusal nuclear bag fibres may increase myofilament Ca2+ -sensitivity and tension, impairing spindle function, thus identifying a novel mechanism for the development of targeted treatment. ABSTRACT A nonsense mutation at codon Glu180 of TNNT1 gene causes Amish nemaline myopathy (ANM), a recessively inherited disease with infantile lethality. TNNT1 encodes the slow skeletal muscle isoform of troponin T (ssTnT). The truncated ssTnT is unable to incorporate into myofilament and is degraded in muscle cells. The symptoms of ANM include muscle weakness, atrophy, contracture and tremors accompanied by clonus. An ssTnT-knockout (KO) mouse model recapitulates key features of ANM such as atrophy of extrafusal slow muscle fibres and increased fatigability. However, the neuromuscular reflex-related symptoms of ANM have not been explained. By isolating muscle spindles from ssTnT-KO and control mice aiming to examine the composition of myofilament proteins, we found that, in contrast to extrafusal fibres, intrafusal fibres contain a significant level of cardiac TnT and the low molecular weight splice form of ssTnT. Intrafusal fibres from ssTnT-KO mice have significantly increased cardiac TnT. Rotarod and balance beam tests revealed impaired neuromuscular co-ordination in ssTnT-KO mice, indicating abnormality in spindle functions. Unlike the wild-type control, the beam running ability of ssTnT-KO mice had a blunted response to a spindle sensitizer, succinylcholine. Immunohistochemistry detected ssTnT and cardiac TnT in nuclear bag fibres, whereas fast skeletal muscle TnT was detected in nuclear chain fibres, and cardiac α-myosin was present in one of the two nuclear bag fibres. The loss of ssTnT and a compensatory increase of cardiac TnT in nuclear bag fibres would increase myofilament Ca2+ -sensitivity and tension, thus affecting spindle activities. This mechanism provides an explanation for the pathophysiology of ANM, as well as a novel target for treatment.
Collapse
Affiliation(s)
| | | | - Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - J.-P. Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| |
Collapse
|
6
|
Sewry CA, Laitila JM, Wallgren-Pettersson C. Nemaline myopathies: a current view. J Muscle Res Cell Motil 2019; 40:111-126. [PMID: 31228046 PMCID: PMC6726674 DOI: 10.1007/s10974-019-09519-9] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
Abstract
Nemaline myopathies are a heterogenous group of congenital myopathies caused by de novo, dominantly or recessively inherited mutations in at least twelve genes. The genes encoding skeletal α-actin (ACTA1) and nebulin (NEB) are the commonest genetic cause. Most patients have congenital onset characterized by muscle weakness and hypotonia, but the spectrum of clinical phenotypes is broad, ranging from severe neonatal presentations to onset of a milder disorder in childhood. Most patients with adult onset have an autoimmune-related myopathy with a progressive course. The wide application of massively parallel sequencing methods is increasing the number of known causative genes and broadening the range of clinical phenotypes. Nemaline myopathies are identified by the presence of structures that are rod-like or ovoid in shape with electron microscopy, and with light microscopy stain red with the modified Gömöri trichrome technique. These rods or nemaline bodies are derived from Z lines (also known as Z discs or Z disks) and have a similar lattice structure and protein content. Their shape in patients with mutations in KLHL40 and LMOD3 is distinctive and can be useful for diagnosis. The number and distribution of nemaline bodies varies between fibres and different muscles but does not correlate with severity or prognosis. Additional pathological features such as caps, cores and fibre type disproportion are associated with the same genes as those known to cause the presence of rods. Animal models are advancing the understanding of the effects of various mutations in different genes and paving the way for the development of therapies, which at present only manage symptoms and are aimed at maintaining muscle strength, joint mobility, ambulation, respiration and independence in the activities of daily living.
Collapse
Affiliation(s)
- Caroline A Sewry
- Dubowitz Neuromuscular Centre, UCL Institute of Child Health and Great Ormond Street Hospital, 30 Guilford Street, London, WC1N 1EH, UK. .,Wolfson Centre of Inherited Neuromuscular Disorders, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK.
| | - Jenni M Laitila
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Carina Wallgren-Pettersson
- Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| |
Collapse
|
7
|
Feng HZ, Jin JP. Carbonic Anhydrase III Is Expressed in Mouse Skeletal Muscles Independent of Fiber Type-Specific Myofilament Protein Isoforms and Plays a Role in Fatigue Resistance. Front Physiol 2016; 7:597. [PMID: 28018233 PMCID: PMC5156832 DOI: 10.3389/fphys.2016.00597] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/16/2016] [Indexed: 01/04/2023] Open
Abstract
Carbonic anhydrase III (CAIII) is a metabolic enzyme and a regulator for intracellular pH. CAIII has been reported with high level expression in slow twitch skeletal muscles. Here we demonstrate that CAIII is expressed in multiple slow and fast twitch muscles of adult mouse independent of the expression of myosin isoforms. Expressing similar fast type of myofilament proteins, CAIII-positive tibial anterior (TA) muscle exhibits higher tolerance to fatigue than that of CAIII-negative fast twitch extensor digitorum longus (EDL) muscle in in situ contractility studies. We further studied the muscles of CAIII knockout (Car3-KO) mice. The loss of CAIII in soleus and TA muscles in Car3-KO mice did not change muscle mass, sarcomere protein isoform contents, and the baseline twitch and tetanic contractility as compared with age-matched wild type (WT) controls. On the other hand, Car3-KO TA muscle showed faster force reduction at the beginning but higher resistance at the end during a fatigue test, followed by slower post fatigue recovery than that of WT TA muscle. Superfused Car3-KO soleus muscle also had faster total force reduction during fatigue test than that of WT soleus. However, it showed a less elevation of resting tension followed by a better post fatigue recovery under acidotic stress. CAIII was detected in neonatal TA and EDL muscle, downregulated during development, and then re-expressed in adult TA but not EDL muscles. The expression of CAIII in Tnnt1-KO myopathy mouse soleus muscle that has diminished slow fiber contents due to the loss of slow troponin T remained high. Car3-KO EDL, TA, and soleus muscles showed no change in the expression of mitochondria biomarker proteins. The data suggest a fiber type independent expression of CAIII with a role in the regulation of intracellular pH in skeletal muscle and may be explored as a target for improving fatigue resistance and for the treatment of TNNT1 myopathies.
Collapse
Affiliation(s)
- Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| |
Collapse
|
8
|
Mondal A, Jin JP. Protein Structure-Function Relationship at Work: Learning from Myopathy Mutations of the Slow Skeletal Muscle Isoform of Troponin T. Front Physiol 2016; 7:449. [PMID: 27790152 PMCID: PMC5062619 DOI: 10.3389/fphys.2016.00449] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 09/20/2016] [Indexed: 12/03/2022] Open
Abstract
Troponin T (TnT) is the sarcomeric thin filament anchoring subunit of the troponin complex in striated muscles. A nonsense mutation in exon 11 of the slow skeletal muscle isoform of TnT (ssTnT) gene (TNNT1) was found in the Amish populations in Pennsylvania and Ohio. This single nucleotide substitution causes a truncation of the ssTnT protein at Glu180 and the loss of the C-terminal tropomyosin (Tm)-binding site 2. As a consequence, it abolishes the myofilament integration of ssTnT and the loss of function causes an autosomal recessive nemaline myopathy (NM). More TNNT1 mutations have recently been reported in non-Amish ethnic groups with similar recessive NM phenotypes. A nonsense mutation in exon 9 truncates ssTnT at Ser108, deleting Tm-binding site 2 and a part of the middle region Tm-binding site 1. Two splicing site mutations result in truncation of ssTnT at Leu203 or deletion of the exon 14-encoded C-terminal end segment. Another splicing mutation causes an internal deletion of the 39 amino acids encoded by exon 8, partially damaging Tm-binding site 1. The three splicing mutations of TNNT1 all preserve the high affinity Tm-binding site 2 but still present recessive NM phenotypes. The molecular mechanisms for these mutations to cause myopathy provide interesting models to study and understand the structure-function relationship of TnT. This focused review summarizes the current knowledge of TnT isoform regulation, structure-function relationship of TnT and how various ssTnT mutations cause recessive NM, in order to promote in depth studies for further understanding the pathogenesis and pathophysiology of TNNT1 myopathies toward the development of effective treatments.
Collapse
Affiliation(s)
- Anupom Mondal
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| |
Collapse
|
9
|
TNNT1, TNNT2, and TNNT3: Isoform genes, regulation, and structure-function relationships. Gene 2016; 582:1-13. [PMID: 26774798 DOI: 10.1016/j.gene.2016.01.006] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 12/31/2015] [Accepted: 01/05/2016] [Indexed: 12/18/2022]
Abstract
Troponin T (TnT) is a central player in the calcium regulation of actin thin filament function and is essential for the contraction of striated muscles. Three homologous genes have evolved in vertebrates to encode three muscle type-specific TnT isoforms: TNNT1 for slow skeletal muscle TnT, TNNT2 for cardiac muscle TnT, and TNNT3 for fast skeletal muscle TnT. Alternative splicing and posttranslational modifications confer additional structural and functional variations of TnT during development and muscle adaptation to various physiological and pathological conditions. This review focuses on the TnT isoform genes and their molecular evolution, alternative splicing, developmental regulation, structure-function relationships of TnT proteins, posttranslational modifications, and myopathic mutations and abnormal splicing. The goal is to provide a concise summary of the current knowledge and some perspectives for future research and translational applications.
Collapse
|
10
|
Jin JP. Evolution, Regulation, and Function of N-terminal Variable Region of Troponin T: Modulation of Muscle Contractility and Beyond. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 321:1-28. [DOI: 10.1016/bs.ircmb.2015.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
11
|
Wei B, Wei H, Jin JP. Dysferlin deficiency blunts β-adrenergic-dependent lusitropic function of mouse heart. J Physiol 2015; 593:5127-44. [PMID: 26415898 DOI: 10.1113/jp271225] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/22/2015] [Indexed: 11/08/2022] Open
Abstract
Dysferlin is a cell membrane bound protein with a role in the repair of skeletal and cardiac muscle cells. Deficiency of dysferlin leads to limb-girdle muscular dystrophy 2B (LGMD2B) and Miyoshi myopathy. In cardiac muscle, dysferlin is located at the intercalated disc and transverse tubule membranes. Loss of dysferlin causes death of cardiomyocytes, notably in ageing hearts, leading to dilated cardiomyopathy and heart failure in LGM2B patients. To understand the primary pathogenesis and pathophysiology of dysferlin cardiomyopathy, we studied cardiac phenotypes of young adult dysferlin knockout mice and found early myocardial hypertrophy with largely compensated baseline cardiac function. Cardiomyocytes isolated from dysferlin-deficient mice showed normal shortening and re-lengthening velocities in the absence of external load with normal peak systolic Ca(2+) but slower Ca(2+) re-sequestration than wild-type controls. The effects of isoproterenol on relaxation velocity, left ventricular systolic pressure and stroke volume were blunted in dysferlin-deficient mouse hearts compared with that in wild-type hearts. Young dysferlin-deficient mouse hearts expressed normal isoforms of myofilament proteins whereas the phosphorylation of ventricular myosin light chain 2 was significantly increased, implying a molecular response to the impaired lusitropic function. These early phenotypes of diastolic cardiac dysfunction and blunted lusitropic response of cardiac muscle to β-adrenergic stimulation indicate a novel pathogenic mechanism of dysferlin cardiomyopathy.
Collapse
Affiliation(s)
- Bin Wei
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Hongguang Wei
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| |
Collapse
|
12
|
Feng HZ, Chen X, Malek MH, Jin JP. Slow recovery of the impaired fatigue resistance in postunloading mouse soleus muscle corresponding to decreased mitochondrial function and a compensatory increase in type I slow fibers. Am J Physiol Cell Physiol 2015; 310:C27-40. [PMID: 26447205 DOI: 10.1152/ajpcell.00173.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/05/2015] [Indexed: 02/08/2023]
Abstract
Unloading or disuse rapidly results in skeletal muscle atrophy, switching to fast-type fibers, and decreased resistance to fatigue. The recovery process is of major importance in rehabilitation for various clinical conditions. Here we studied mouse soleus muscle during 60 days of reloading after 4 wk of hindlimb suspension. Unloading produced significant atrophy of soleus muscle with decreased contractile force and fatigue resistance, accompanied by switches of myosin isoforms from IIa to IIx and IIb and fast troponin T to more low-molecular-weight splice forms. The total mass, fiber size, and contractile force of soleus muscle recovered to control levels after 15 days of reloading. However, the fatigue resistance showed a trend of worsening during this period with significant infiltration of inflammatory cells at days 3 and 7, indicating reloading injuries that were accompanied by active regeneration with upregulations of filamin-C, αB-crystallin, and desmin. The fatigue resistance partially recovered after 30-60 days of reloading. The expression of peroxisome proliferator-activated receptor γ coactivator 1α and mitofusin-2 showed changes parallel to that of fatigue resistance after unloading and during reloading, suggesting a causal role of decreased mitochondrial function. Slow fiber contents in the soleus muscle were increased after 30-60 days of reloading to become significantly higher than the normal level, indicating a secondary adaption to compensate for the slow recovery of fatigue resistance.
Collapse
Affiliation(s)
- Han-Zhong Feng
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Xuequn Chen
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Moh H Malek
- Department of Health Care Sciences, Wayne State University, Detroit, Michigan
| | - J-P Jin
- Department of Physiology, Wayne State University, Detroit, Michigan;
| |
Collapse
|
13
|
Abdulhaq UN, Daana M, Dor T, Fellig Y, Eylon S, Schuelke M, Shaag A, Elpeleg O, Edvardson S. Nemaline body myopathy caused by a novel mutation in troponin T1 (TNNT1
). Muscle Nerve 2015; 53:564-9. [DOI: 10.1002/mus.24885] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 08/16/2015] [Accepted: 08/20/2015] [Indexed: 11/12/2022]
Affiliation(s)
- Ulla Najwa Abdulhaq
- Department of Pediatrics; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Mohannad Daana
- Department of Pediatrics; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Talia Dor
- Department of Pediatrics; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Yakov Fellig
- Department of Pathology Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Sharon Eylon
- Alyn Hospital Pediatric and Adolescent Rehabilitation Center; Jerusalem Israel
| | - Markus Schuelke
- Klinik für Pädiatrie Neurologie and NeuroCure Clinical Research Center, Charité-Universitätsmedizin; Berlin Germany
| | - Avraham Shaag
- Monique and Jacques Roboh Department of Genetic Research; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Orly Elpeleg
- Monique and Jacques Roboh Department of Genetic Research; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Simon Edvardson
- Department of Pediatrics; Hadassah-Hebrew University Medical Center; Jerusalem Israel
- Monique and Jacques Roboh Department of Genetic Research; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| |
Collapse
|
14
|
Wu T, Chen J, Zhu J, Yu Z. Association between the transcriptional levels of Htr-1a and tryptophan hydroxylase-1 in the hippocampus and the antifatigue effects of leucine on rats with postoperative fatigue. Exp Ther Med 2014; 8:1633-1637. [PMID: 25289072 PMCID: PMC4186329 DOI: 10.3892/etm.2014.1973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 07/16/2014] [Indexed: 11/05/2022] Open
Abstract
Leucine (Leu), a branched-chain amino acid (BCAA), is widely used in clinical practice following severe burns, gastrointestinal surgery, trauma and sepsis. In the present study, the antifatigue effects of BCAAs on a postoperative fatigue (POF) rat model, induced by 70% intestinal resection, were investigated. Leu (16.5 g/l) was administered intraperitoneally at a dose of 18 ml/kg/day. The fatigue level and antifatigue effects of Leu were evaluated by open-field testing on day 1, 3, 5 and 7 after surgery. In addition, mRNA specimens were extracted and measured using a quantitative polymerase chain reaction method. The open-field test results indicated that Leu exhibited a significant antifatigue effect. The total distance travelled and the number of times the rats passed from the outermost grids of an open-top case were greatly improved in the Leu treatment group when compared with the POF model group. With the exception of the normal group, the mRNA expression levels of Htr-1a exhibited a similar trend in all other groups, reaching a climax on day 3 and 5, while being restored to a normal level on day 7. With regard to the Leu intervention group, the mRNA expression level of Htr-1a decreased significantly on day 3 and 5 following surgery. The mRNA expression levels of tryptophan hydroxylase-1 were unchanged in this short time period; however, the levels were increased gradually in the Leu treatment group. Therefore, Leu exhibited an apparent antifatigue effect on various 5-hydroxytryptamine-associated genes.
Collapse
Affiliation(s)
- Tiantian Wu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China
| | - Jing Chen
- Department of Rheumatology, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China
| | - Jiang Zhu
- Department of Gastrointestinal Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325035, P.R. China
| | - Zhen Yu
- Department of General Surgery, Shanghai Tenth People's Hospital Affiliated to Tongji University, Shanghai 200072, P.R. China
| |
Collapse
|
15
|
Sheng JJ, Jin JP. Gene regulation, alternative splicing, and posttranslational modification of troponin subunits in cardiac development and adaptation: a focused review. Front Physiol 2014; 5:165. [PMID: 24817852 PMCID: PMC4012202 DOI: 10.3389/fphys.2014.00165] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 04/10/2014] [Indexed: 12/19/2022] Open
Abstract
Troponin plays a central role in regulating the contraction and relaxation of vertebrate striated muscles. This review focuses on the isoform gene regulation, alternative RNA splicing, and posttranslational modifications of troponin subunits in cardiac development and adaptation. Transcriptional and posttranscriptional regulations such as phosphorylation and proteolysis modifications, and structure-function relationships of troponin subunit proteins are summarized. The physiological and pathophysiological significances are discussed for impacts on cardiac muscle contractility, heart function, and adaptations in health and diseases.
Collapse
Affiliation(s)
- Juan-Juan Sheng
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| | - Jian-Ping Jin
- Department of Physiology, Wayne State University School of Medicine Detroit, MI, USA
| |
Collapse
|
16
|
Liu R, Feng HZ, Jin JP. Physiological contractility of cardiomyocytes in the wall of mouse and rat azygos vein. Am J Physiol Cell Physiol 2014; 306:C697-704. [PMID: 24477237 PMCID: PMC3962596 DOI: 10.1152/ajpcell.00004.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 01/25/2014] [Indexed: 01/19/2023]
Abstract
We recently demonstrated the abundant presence of cardiomyocytes in the wall of thoracic veins of adult mouse and rat. The highly differentiated morphology and myofilament protein contents of the venous cardiomyocytes suggested contractile functions. Here we further investigated the contractility of mouse and rat azygos venous rings compared with that of atrial strips and ventricular papillary muscle. 5-Bromo-4-chloro-indolyl-galactopyranoside (X-gal) staining of transgenic mouse vessels expressing lacZ under a cloned cardiac troponin T promoter demonstrated that the venous cardiomyocytes are discontinuous from atrial myocardium and aligned in the wall of thoracic veins perpendicular to the vessel axis. Histological sections displayed sarcomeric striations in the venous cardiomyocytes, which indicate an encirclement orientation of myofibrils in the vessel wall. Mechanical studies found that the rings of mouse and rat azygos vein produce strong cardiac type twitch contractions when stimulated with electrical pacing in contrast to the weak and slow smooth muscle contractions induced using 90 mM KCl. The twitch contraction and relaxation of mouse azygos veins further exhibited a cardiac type of β-adrenergic responses. Quantitative comparison showed that the contractions of venous cardiomyocytes are slightly slower than those of atrium muscle but significantly faster than those of ventricular papillary muscle. These novel findings indicate that the cardiomyocytes abundant in the wall of rodent thoracic veins possess fully differentiated cardiac muscle phenotype despite their anatomical and functional segregations from the heart.
Collapse
Affiliation(s)
- Rong Liu
- Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan
| | | | | |
Collapse
|
17
|
Chen JC, Hsiang CY, Lin YC, Ho TY. Deer Antler Extract Improves Fatigue Effect through Altering the Expression of Genes Related to Muscle Strength in Skeletal Muscle of Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2014; 2014:540580. [PMID: 24701242 PMCID: PMC3950920 DOI: 10.1155/2014/540580] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 12/28/2013] [Accepted: 01/03/2014] [Indexed: 11/17/2022]
Abstract
Deer antler is a well-known traditional Chinese medicine used in Asian countries for the tonic and the improvement of aging symptoms. The present study was designed to investigate the antifatigue effect and mechanism of Formosan sambar deer tip antler extract (FSDTAE). The swimming times to exhaustion of mice administered FSDTAE (8.2 mg/day) for 28 days were apparently longer than those of the vehicle-treated mice in forced swim test. However, the indicators of fatigue, such as the reduction in glucose level and the increases in blood urea nitrogen and lactic acid levels, were not significantly inhibited by FSDTAE. Therefore, microarray analysis was further used to examine the anti-fatigue mechanism of FSDTAE. We selected genes with fold changes >2 or <-2 in skeletal muscle for pathway analysis. FSDTAE-affected genes were involved in 9 different signaling pathways, such as GnRH signaling pathway and insulin signaling pathway. All of the significantly expressed genes were classified into 8 different categories by their functions. The most enriched category was muscular system, and 6 upregulated genes, such as troponin I, troponin T1, cysteine and glycine-rich protein 2, myosin heavy polypeptide 7, tropomyosin 2, and myomesin family member 3, were responsible for the development and contraction of muscle. Real-time PCR analysis indicated that FSDTAE increased troponins mRNA expression in skeletal muscle. In conclusion, our findings suggested that FSDTAE might increase the muscle strength through the upregulation of genes responsible for muscle contraction and consequently exhibited the anti-fatigue effect in mice.
Collapse
Affiliation(s)
- Jaw-Chyun Chen
- Department of Medicinal Botany and Health Applications, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan
| | - Chien-Yun Hsiang
- Department of Microbiology, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| | - Yung-Chang Lin
- Department of Veterinary Medicine, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 40227, Taiwan
| | - Tin-Yun Ho
- Graduate Institute of Chinese Medicine, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan
| |
Collapse
|
18
|
Wei B, Lu Y, Jin JP. Deficiency of slow skeletal muscle troponin T causes atrophy of type I slow fibres and decreases tolerance to fatigue. J Physiol 2014; 592:1367-80. [PMID: 24445317 DOI: 10.1113/jphysiol.2013.268177] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The total loss of slow skeletal muscle troponin T (ssTnT encoded by TNNT1 gene) due to a nonsense mutation in codon Glu(180) causes a lethal form of recessively inherited nemaline myopathy (Amish nemaline myopathy, ANM). To investigate the pathogenesis and muscle pathophysiology of ANM, we studied the phenotypes of partial and total loss of ssTnT in Tnnt1 gene targeted mice. An insertion of neomycin resistance cassette in intron 10 of Tnnt1 gene caused an approximately 60% decrease in ssTnT protein expression whereas cre-loxP-mediated deletion of exons 11-13 resulted in total loss of ssTnT, as seen in ANM muscles. In diaphragm and soleus muscles of the knockdown and knockout mouse models, we demonstrated that ssTnT deficiency resulted in significantly decreased levels of other slow fibre-specific myofilament proteins whereas fast fibre-specific myofilament proteins were increased correspondingly. Immunohistochemical studies revealed that ssTnT deficiency produced significantly smaller type I slow fibres and compensatory growth of type II fast fibres. Along with the slow fibre atrophy and the changes in myofilament protein isoform contents, ssTnT deficiency significantly reduced the tolerance to fatigue in soleus muscle. ssTnT-deficient soleus muscle also contains significant numbers of small-sized central nuclei type I fibres, indicating active regeneration. The data provide strong support for the essential role of ssTnT in skeletal muscle function and the causal effect of its loss in the pathology of ANM. This observation further supports the hypothesis that the function of slow fibres can be restored in ANM patients if a therapeutic supplement of ssTnT is achieved.
Collapse
Affiliation(s)
- Bin Wei
- Department of Physiology, Wayne State University School of Medicine, Detroit MI 48201, USA.
| | | | | |
Collapse
|
19
|
van der Pol WL, Leijenaar JF, Spliet WGM, Lavrijsen SW, Jansen NJG, Braun KPJ, Mulder M, Timmers-Raaijmakers B, Ratsma K, Dooijes D, van Haelst MM. Nemaline myopathy caused byTNNT1 mutations in a Dutch pedigree. Mol Genet Genomic Med 2013; 2:134-7. [PMID: 24689076 PMCID: PMC3960055 DOI: 10.1002/mgg3.52] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 10/29/2013] [Accepted: 10/30/2013] [Indexed: 12/04/2022] Open
Abstract
Nemaline myopathy (NM) is genetically heterogeneous disorder characterized by early onset muscular weakness and sarcoplasmatic or intranuclear inclusions of rod-shaped Z-disk material in muscle fibers. Thus far, mutations in seven genes have been identified as cause of NM. Only one singleTNNT1 nonsense mutation has been previously described that causes autosomal recessive NM in the old order Amish with a very specific clinical phenotype including rapidly progressive contractures. Here, we report a patient who is compound heterozygous for a c.309+1G>A mutation and an exon 14 deletion in theTNNT1 gene. This report confirms the specific clinical phenotype ofTNNT1 NM and documents two newTNNT1 mutations outside the old order Amish.
Collapse
Affiliation(s)
- W Ludo van der Pol
- Rudolf Magnus Institute of Neuroscience, Department of Neurology and Neurosurgery, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Jolien F Leijenaar
- Department of Medical Genetics, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Wim G M Spliet
- Department of Pathology, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Selma W Lavrijsen
- Department of Pathology, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Nicolaas J G Jansen
- Department of Pathology, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Kees P J Braun
- Rudolf Magnus Institute of Neuroscience, Department of Neurology and Neurosurgery, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Marcel Mulder
- Department of Medical Genetics, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Brigitte Timmers-Raaijmakers
- Department of Pediatrics, Pediatric Intensive Care, Wilhelmina Children's Hospital, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Kimberly Ratsma
- Department of Medical Genetics, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Dennis Dooijes
- Department of Medical Genetics, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| | - Mieke M van Haelst
- Department of Medical Genetics, University Medical Center Utrecht 3584 EA, Utrecht, The Netherlands
| |
Collapse
|
20
|
Selsby JT, Acosta P, Sleeper MM, Barton ER, Sweeney HL. Long-term wheel running compromises diaphragm function but improves cardiac and plantarflexor function in the mdx mouse. J Appl Physiol (1985) 2013; 115:660-6. [PMID: 23823150 DOI: 10.1152/japplphysiol.00252.2013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Dystrophin-deficient muscles suffer from free radical injury, mitochondrial dysfunction, apoptosis, and inflammation, among other pathologies that contribute to muscle fiber injury and loss, leading to wheelchair confinement and death in the patient. For some time, it has been appreciated that endurance training has the potential to counter many of these contributing factors. Correspondingly, numerous investigations have shown improvements in limb muscle function following endurance training in mdx mice. However, the effect of long-term volitional wheel running on diaphragm and cardiac function is largely unknown. Our purpose was to determine the extent to which long-term endurance exercise affected dystrophic limb, diaphragm, and cardiac function. Diaphragm specific tension was reduced by 60% (P < 0.05) in mice that performed 1 yr of volitional wheel running compared with sedentary mdx mice. Dorsiflexor mass (extensor digitorum longus and tibialis anterior) and function (extensor digitorum longus) were not altered by endurance training. In mice that performed 1 yr of volitional wheel running, plantarflexor mass (soleus and gastrocnemius) was increased and soleus tetanic force was increased 36%, while specific tension was similar in wheel-running and sedentary groups. Cardiac mass was increased 15%, left ventricle chamber size was increased 20% (diastole) and 18% (systole), and stroke volume was increased twofold in wheel-running compared with sedentary mdx mice. These data suggest that the dystrophic heart may undergo positive exercise-induced remodeling and that limb muscle function is largely unaffected. Most importantly, however, as the diaphragm most closely recapitulates the human disease, these data raise the possibility of exercise-mediated injury in dystrophic skeletal muscle.
Collapse
Affiliation(s)
- Joshua T Selsby
- Department of Animal Science, College of Agriculture and Life Sciences, Iowa State University, Ames, Iowa
| | | | | | | | | |
Collapse
|
21
|
Ikonomov OC, Sbrissa D, Delvecchio K, Feng HZ, Cartee GD, Jin JP, Shisheva A. Muscle-specific Pikfyve gene disruption causes glucose intolerance, insulin resistance, adiposity, and hyperinsulinemia but not muscle fiber-type switching. Am J Physiol Endocrinol Metab 2013; 305:E119-31. [PMID: 23673157 PMCID: PMC3725567 DOI: 10.1152/ajpendo.00030.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The evolutionarily conserved kinase PIKfyve that synthesizes PtdIns5P and PtdIns(3,5)P₂ has been implicated in insulin-regulated GLUT4 translocation/glucose entry in 3T3-L1 adipocytes. To decipher PIKfyve's role in muscle and systemic glucose metabolism, here we have developed a novel mouse model with Pikfyve gene disruption in striated muscle (MPIfKO). These mice exhibited systemic glucose intolerance and insulin resistance at an early age but had unaltered muscle mass or proportion of slow/fast-twitch muscle fibers. Insulin stimulation of in vivo or ex vivo glucose uptake and GLUT4 surface translocation was severely blunted in skeletal muscle. These changes were associated with premature attenuation of Akt phosphorylation in response to in vivo insulin, as tested in young mice. Starting at 10-11 wk of age, MPIfKO mice progressively accumulated greater body weight and fat mass. Despite increased adiposity, serum free fatty acid and triglyceride levels were normal until adulthood. Together with the undetectable lipid accumulation in liver, these data suggest that lipotoxicity and muscle fiber switching do not contribute to muscle insulin resistance in MPIfKO mice. Furthermore, the 80% increase in total fat mass resulted from increased fat cell size rather than altered fat cell number. The observed profound hyperinsulinemia combined with the documented increases in constitutive Akt activation, in vivo glucose uptake, and gene expression of key enzymes for fatty acid biosynthesis in MPIfKO fat tissue suggest that the latter is being sensitized for de novo lipid anabolism. Our data provide the first in vivo evidence that PIKfyve is essential for systemic glucose homeostasis and insulin-regulated glucose uptake/GLUT4 translocation in skeletal muscle.
Collapse
Affiliation(s)
- Ognian C Ikonomov
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | | | | | | | | | | | | |
Collapse
|
22
|
Wei B, Dui W, Liu D, Xing Y, Yuan Z, Ji G. MST1, a key player, in enhancing fast skeletal muscle atrophy. BMC Biol 2013; 11:12. [PMID: 23374633 PMCID: PMC3606410 DOI: 10.1186/1741-7007-11-12] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 02/01/2013] [Indexed: 02/06/2023] Open
Abstract
Background Skeletal muscle undergoes rapid atrophy upon denervation and the underlying mechanisms are complicated. FOXO3a has been implicated as a major mediator of muscle atrophy, but how its subcellular location and activity is controlled during the pathogenesis of muscle atrophy remains largely unknown. MST1 (Mammalian Sterile 20-like kinase 1) is identified as a central component of the Hippo signaling pathway. MST1 has been shown to mediate phosphorylation of FOXO3a at Ser207. Whether this MST1-FOXO signaling cascade exerts any functional consequence on cellular homeostasis remains to be investigated. Result We identified that MST1 kinase was expressed widely in skeletal muscles and was dramatically up-regulated in fast- but not slow-dominant skeletal muscles immediately following denervation. The results of our histological and biochemical studies demonstrated that deletion of MST1 significantly attenuated denervation-induced skeletal muscle wasting and decreased expression of Atrogin-1 and LC3 genes in fast-dominant skeletal muscles from three- to five-month-old adult mice. Further studies indicated that MST1, but not MST2, remarkably increased FOXO3a phosphorylation level at Ser207 and promoted its nuclear translocation in atrophic fast-dominant muscles. Conclusions We have established that MST1 kinase plays an important role in regulating denervation-induced skeletal muscle atrophy. During the early stage of muscle atrophy, the up-regulated MST1 kinase promoted progression of neurogenic atrophy in fast-dominant skeletal muscles through activation of FOXO3a transcription factors.
Collapse
Affiliation(s)
- Bin Wei
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Datun Road 15, Beijing 100101, China
| | | | | | | | | | | |
Collapse
|
23
|
Kracklauer MP, Feng HZ, Jiang W, Lin JLC, Lin JJC, Jin JP. Discontinuous thoracic venous cardiomyocytes and heart exhibit synchronized developmental switch of troponin isoforms. FEBS J 2013; 280:880-91. [PMID: 23176202 DOI: 10.1111/febs.12076] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 11/14/2012] [Accepted: 11/20/2012] [Indexed: 02/04/2023]
Abstract
Cardiomyocyte-like cells have been reported in thoracic veins of rodents and other mammals, but their differentiation state and relationship to the muscle mass in the heart remain to be characterized. Here we investigated the distribution, ultrastructure, expression and developmental regulation of myofilament proteins of mouse and rat pulmonary and azygos venous cardiomyocytes. Tracing cardiomyocytes in transgenic mouse tissues using a lacZ reporter gene driven by a cloned rat cardiac troponin T promoter demonstrated scattered distribution of cardiomyocytes discontinuous from the atrial sleeves. The longitudinal axis of venous cardiomyocytes is perpendicular to that of the vessel. These cells contain typical sarcomere structures and intercalated discs as shown in electron microscopic images, and express cardiac isoforms of troponin T, troponin I and myosin. The expression of troponin I isoform genes and the alternative splicing of cardiac troponin T in thoracic venous cardiomyocytes are regulated during postnatal development in precise synchrony with that in the heart. However, the patterns of cardiac troponin T splicing in adult rat thoracic venous cardiomyocytes are slightly but clearly distinct from those in the atrial and ventricular muscles. The data indicate that mouse and rat thoracic venous cardiomyocytes residing in extra-cardiac tissue possess a physiologically differentiated state and an intrinsically pre-set developmental clock, which are apparently independent of the very different hemodynamic environments and functional features of the vessels and heart.
Collapse
Affiliation(s)
- Martin P Kracklauer
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | | | | | | | | | | |
Collapse
|
24
|
Feng HZ, Chen X, Hossain MM, Jin JP. Toad heart utilizes exclusively slow skeletal muscle troponin T: an evolutionary adaptation with potential functional benefits. J Biol Chem 2012; 287:29753-64. [PMID: 22778265 PMCID: PMC3436204 DOI: 10.1074/jbc.m112.373191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 07/02/2012] [Indexed: 11/06/2022] Open
Abstract
The three isoforms of vertebrate troponin T (TnT) are normally expressed in a muscle type-specific manner. Here we report an exception that the cardiac muscle of toad (Bufo) expresses exclusively slow skeletal muscle TnT (ssTnT) together with cardiac forms of troponin I and myosin as determined using immunoblotting, cDNA cloning, and/or LC-MS/MS. Using RT-PCR and 3'- and 5'-rapid amplification of cDNA ends on toad cardiac mRNA, we cloned full-length cDNAs encoding two alternatively spliced variants of ssTnT. Expression of the cloned cDNAs in Escherichia coli confirmed that the toad cardiac muscle expresses solely ssTnT, predominantly the low molecular weight variant with the exon 5-encoded NH(2)-terminal segment spliced out. Functional studies were performed in ex vivo working toad hearts and compared with the frog (Rana) hearts. The results showed that toad hearts had higher contractile and relaxation velocities and were able to work against a significantly higher afterload than that of frog hearts. Therefore, the unique evolutionary adaptation of utilizing exclusively ssTnT in toad cardiac muscle corresponded to a fitness value from improving systolic function of the heart. The data demonstrated a physiological importance of the functional diversity of TnT isoforms. The structure-function relationship of TnT may be explored for the development of new treatment of heart failure.
Collapse
Affiliation(s)
- Han-Zhong Feng
- From the Department of Physiology, Wayne State University School of
Medicine, Detroit, Michigan 48201
| | - Xuequn Chen
- From the Department of Physiology, Wayne State University School of
Medicine, Detroit, Michigan 48201
| | - M. Moazzem Hossain
- From the Department of Physiology, Wayne State University School of
Medicine, Detroit, Michigan 48201
| | - Jian-Ping Jin
- From the Department of Physiology, Wayne State University School of
Medicine, Detroit, Michigan 48201
| |
Collapse
|
25
|
Barolo S. Shadow enhancers: frequently asked questions about distributed cis-regulatory information and enhancer redundancy. Bioessays 2012; 34:135-41. [PMID: 22083793 PMCID: PMC3517143 DOI: 10.1002/bies.201100121] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This paper, in the form of a frequently asked questions page (FAQ), addresses outstanding questions about "shadow enhancers", quasi-redundant cis-regulatory elements, and their proposed roles in transcriptional control. Questions include: What exactly are shadow enhancers? How many genes have shadow/redundant/distributed enhancers? How redundant are these elements? What is the function of distributed enhancers? How modular are enhancers? Is it useful to study a single enhancer in isolation? In addition, a revised definition of "shadow enhancers" is proposed, and possible mechanisms of shadow enhancer function and evolution are discussed.
Collapse
Affiliation(s)
- Scott Barolo
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.
| |
Collapse
|
26
|
Abstract
Nemaline myopathy constitutes a continuous spectrum of primary skeletal muscle disorders named after the Greek word for thread, nema. The diagnosis is based on muscle weakness, combined with visualization of nemaline bodies on muscle biopsy. The patients' muscle weakness is usually generalized, but there may be a selective pattern of more pronounced weakness, and, most importantly, respiratory muscles may be especially weak. Histologically, additional features may coexist with the nemaline bodies. There are 7 known causative genes. The function of the most recently identified gene is unknown, but the other 6 encoded proteins are associated with the muscle thin filament. The 2 most common causes of nemaline myopathy are recessive mutations in nebulin and de novo dominant mutations in skeletal muscle α-actin. At least 1 further gene remains to be identified. Patient care is based on managing the clinical symptoms. Animal models are helping to gain insight into pathogenesis, and a variety of therapeutic approaches are being investigated.
Collapse
Affiliation(s)
- Carina Wallgren-Pettersson
- The Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland.
| | | | | | | |
Collapse
|
27
|
Feng HZ, Chen M, Weinstein LS, Jin JP. Improved fatigue resistance in Gsα-deficient and aging mouse skeletal muscles due to adaptive increases in slow fibers. J Appl Physiol (1985) 2011; 111:834-43. [PMID: 21680879 DOI: 10.1152/japplphysiol.00031.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genetically modified mice with deficiency of the G protein α-subunit (G(s)α) in skeletal muscle showed metabolic abnormality with reduced glucose tolerance, low muscle mass, and low contractile force, along with a fast-to-slow-fiber-type switch (Chen M, Feng HZ, Gupta D, Kelleher J, Dickerson KE, Wang J, Hunt D, Jou W, Gavrilova O, Jin JP, Weinstein LS. Am J Physiol Cell Physiol 296: C930-C940, 2009). Here we investigated a hypothesis that the switching to more slow fibers is an adaptive response with specific benefit. The results showed that, corresponding to the switch of myosin isoforms, the thin-filament regulatory proteins troponin T and troponin I both switched to their slow isoforms in the atrophic soleus muscle of 3-mo-old G(s)α-deficient mice. This fiber-type switch involving coordinated changes of both thick- and thin-myofilament proteins progressed in the G(s)α-deficient soleus muscles of 18- to 24-mo-old mice, as reflected by the expression of solely slow isoforms of myosin and troponin. Compared with age-matched controls, G(s)α-deficient soleus muscles with higher proportion of slow fibers exhibited slower contractile and relaxation kinetics and lower developed force, but significantly increased resistance to fatigue, followed by a better recovery. G(s)α-deficient soleus muscles of neonatal and 3-wk-old mice did not show the increase in slow fibers. Therefore, the fast-to-slow-fiber-type switch in G(s)α deficiency at older ages was likely an adaptive response. The benefit of higher fatigue resistance in adaption to metabolic deficiency and aging provides a mechanism to sustain skeletal muscle function in diabetic patients and elderly individuals.
Collapse
Affiliation(s)
- Han-Zhong Feng
- Dept. of Physiology, Wayne State Univ. School of Medicine, Detroit, Michigan 48201, USA
| | | | | | | |
Collapse
|
28
|
Troponin T isoforms and posttranscriptional modifications: Evolution, regulation and function. Arch Biochem Biophys 2010; 505:144-54. [PMID: 20965144 DOI: 10.1016/j.abb.2010.10.013] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Revised: 10/12/2010] [Accepted: 10/14/2010] [Indexed: 12/11/2022]
Abstract
Troponin-mediated Ca²(+)-regulation governs the actin-activated myosin motor function which powers striated (skeletal and cardiac) muscle contraction. This review focuses on the structure-function relationship of troponin T, one of the three protein subunits of the troponin complex. Molecular evolution, gene regulation, alternative RNA splicing, and posttranslational modifications of troponin T isoforms in skeletal and cardiac muscles are summarized with emphases on recent research progresses. The physiological and pathophysiological significances of the structural diversity and regulation of troponin T are discussed for impacts on striated muscle function and adaptation in health and diseases.
Collapse
|
29
|
Current world literature. Curr Opin Rheumatol 2010; 22:704-12. [PMID: 20881793 DOI: 10.1097/bor.0b013e3283404094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|