scholarly journals From Slow to Fast: Hypogravity-Induced Remodeling of Muscle Fiber Myosin Phenotype

Acta Naturae ◽  
2016 ◽  
Vol 8 (4) ◽  
pp. 47-59 ◽  
Author(s):  
B. S. Shenkman
Keyword(s):  
Gene Expression ◽  
Muscle Fiber ◽  
Molecular Mechanisms ◽  
Fiber Types ◽  
Contraction Force ◽  
Gravitational Unloading ◽  
Fast Myosin ◽  
Slow Type ◽  
Fast Myosin Heavy Chain ◽  
High Level

Skeletal muscle consists of different fiber types arranged in a mosaic pattern. These fiber types are characterized by specific functional properties. Slow-type fibers demonstrate a high level of fatigue resistance and prolonged contraction duration, but decreased maximum contraction force and velocity. Fast-type fibers demonstrate a high contraction force and velocity, but profound fatigability. During the last decades, it has been discovered that all these properties are determined by the predominance of slow or fast myosin-heavy-chain (MyHC) isoforms. It was observed that gravitational unloading during space missions and simulated microgravity in ground-based experiments leads to the transformation of some slow-twitch muscle fibers into fast-twitch ones due to changes in the patterns of MyHC gene expression in the postural soleus muscle. The present review covers the facts and mechanistic speculations regarding myosin phenotype remodeling under conditions of gravitational unloading. The review considers the neuronal mechanisms of muscle fiber control and molecular mechanisms of regulation of myosin gene expression, such as inhibition of the calcineurin/NFATc1 signaling pathway, epigenomic changes, and the behavior of specific microRNAs. In the final portion of the review, we discuss the adaptive role of myosin phenotype transformations.

scholarly journals Properties of skeletal muscle in the teleost Sternopygus macrurus are unaffected by short-term electrical inactivity

2016 ◽  
Vol 48 (9) ◽  
pp. 699-710 ◽  
Author(s):  
Robert Güth ◽  
Alexander Chaidez ◽  
Manoj P. Samanta ◽  
Graciela A. Unguez
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Electrical Activity ◽  
Muscle Fiber ◽  
Model Systems ◽  
Control Fish ◽  
Type I ◽  
Fiber Types ◽  
Spinal Transection ◽  
Fiber Size

Skeletal muscle is distinguished from other tissues on the basis of its shape, biochemistry, and physiological function. Based on mammalian studies, fiber size, fiber types, and gene expression profiles are regulated, in part, by the electrical activity exerted by the nervous system. To address whether similar adaptations to changes in electrical activity in skeletal muscle occur in teleosts, we studied these phenotypic properties of ventral muscle in the electric fish Sternopygus macrurus following 2 and 5 days of electrical inactivation by spinal transection. Our data show that morphological and biochemical properties of skeletal muscle remained largely unchanged after these treatments. Specifically, the distribution of type I and type II muscle fibers and the cross-sectional areas of these fiber types observed in control fish remained unaltered after each spinal transection survival period. This response to electrical inactivation was generally reflected at the transcript level in real-time PCR and RNA-seq data by showing little effect on the transcript levels of genes associated with muscle fiber type differentiation and plasticity, the sarcomere complex, and pathways implicated in the regulation of muscle fiber size. Data from this first study characterizing the acute influence of neural activity on muscle mass and sarcomere gene expression in a teleost are discussed in the context of comparative studies in mammalian model systems and vertebrate species from different lineages.

scholarly journals Dietary Regulation of Fat Oxidative Gene Expression in Different Skeletal Muscle Fiber Types

2003 ◽  
Vol 11 (12) ◽  
pp. 1471-1479 ◽  
Author(s):  
Andrew J. McAinch ◽  
Jong-Sam Lee ◽  
Clinton R. Bruce ◽  
Rebecca J. Tunstall ◽  
John A. Hawley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Skeletal Muscle Fiber ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Dietary Regulation

PSVI-24 Effects of early-life exposure to topsoil on the muscle fiber characteristics and gene expression of weaned piglets

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 386-386
Author(s):  
Yongjie Wang ◽  
Tsung-Cheng Cheng Tsai ◽  
Shilei Zhang ◽  
Jiangchao Zhao ◽  
Yan Huang
Keyword(s):  
Gene Expression ◽  
Protein Expression ◽  
Muscle Fiber ◽  
Fat Metabolism ◽  
Intramuscular Fat ◽  
Fiber Types ◽  
Early Exposure ◽  
Soil Group ◽  
Normal Soil ◽  
Soil Groups

Abstract The objective of this experiment was to investigate the influence of early exposure to topsoil on the muscle fiber characteristics and transcription-related myogenesis, intramuscular fat metabolism, muscle fiber types, and mTOR signaling pathway of weaned pigs. A Total of 180 piglets were separately assigned to the No soil, Antibacterial soil, and Normal soil group (each group, n = 60), and were fed ad libitum with common antibiotic-free corn-soybean meal diets until day-31. Ten pigs from each group with similar body weight were selected to be slaughtered, and the Longissimus dorsi (LD) muscle samples were collected for histological analysis and measurements of genes and protein expression levels. In the present study, the muscle fiber diameter and the area of the Normal soil and Antibacterial soil group were significantly higher than the No soil group (P < 0.05). The Normal soil significantly upregulated the gene expression of MyoG compared to No soil and Antibacterial soil groups (P < 0.05). The gene expression of CD36 and CPT-1 of the Normal soil group was significantly lower than the No soil group (P < 0.05), while HSL expression of the Normal soil group was significantly higher than the Antibacterial and No soil groups (P < 0.05). The MyHC I of the Normal soil group was significantly higher than the No soil group (P < 0.05), but the expression MyHC IIa was lower than the No soil group (P < 0.05). The protein expression expressed a similar result with gene expression. In addition, the Normal soil significantly increased the AMPK and mTOR phosphorylation compared to No soil and Antibacterial soil groups (P < 0.05). These data suggest that early exposure to topsoil regulates muscle fiber growth, modulates the expression pattern related to myogenesis, muscle fiber type, intramuscular fat metabolism, and increases the phosphorylation of mTOR and AMPK pathways.

Enhancement of hybrid-fiber types in rat soleus muscle after clenbuterol administration during hindlimb unloading

2004 ◽  
Vol 82 (5) ◽  
pp. 311-318 ◽  
Author(s):  
F Picquet ◽  
L De-Doncker ◽  
M Falempin
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Fiber Type ◽  
Myosin Heavy Chain Isoforms ◽  
Hindlimb Unloading ◽  
Fiber Types ◽  
Myosin Isoforms ◽  
Fast Myosin ◽  
Contractile Parameters ◽  
Fast Myosin Heavy Chain

Our objective was to determine the effects of a clenbuterol (CB) treatment orally administered (2 mg per kg) to rats submitted to 14 days of hindlimb unloading (HU). The morphological and the contractile properties as well as the myosin heavy chain isoforms contained in each fiber type were determined in whole soleus muscles. As classically described after HU, a decrease in muscle wet weight and in body mass associated with a loss of muscular force, an evolution of the contractile parameters towards those of a fast muscle type, and the emergence of fast myosin heavy chain isoforms were observed. The CB treatment in the HU rats helped reduce the decrease in 1) muscle and body weights, 2) force and 3) the proportion of slow fibers, without preventing the emergence of fast myosin isoforms. Clenbuterol induced a complex remodelling of the muscle typing promoting the combination of both slow and fast myosin isoforms within one fiber. To conclude, our data demonstrate that CB administration partially counteracts the effects produced by HU, and they allow us to anticipate advances in the treatment of muscular atrophy.Key words: β2 agonist, clenbuterol, soleus, contractile parameters, myosin, immunohistochemistry, simulated microgravity, countermeasure.

scholarly journals Effects of Early-Life Exposure to Topsoil on the Muscle Fiber Characteristics and Gene Expression of Weaned Piglets

2021 ◽  
Author(s):  
Yongjie Wang ◽  
Tsung Cheng Tsai ◽  
Palika Morse ◽  
Shilei Zhang ◽  
Charles Maxwell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Muscle Fiber ◽  
Fat Metabolism ◽  
Intramuscular Fat ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Early Exposure ◽  
Soil Group ◽  
Normal Soil ◽  
Soil Groups

Abstract Background: The objective of this experiment was to investigate the influence of early exposure to topsoil on the muscle fiber characteristics and transcription related myogenesis, intramuscular fat metabolism, muscle fiber types, and mTOR signaling pathway of weaned pigs.Methods: A Total of 180 piglets were separately assigned to No soil, Antibacterial soil, and Normal soil group (each group, n=60), and were fed ad libitum with common antibiotic-free corn-soybean meal diets until day-31. Ten pigs from each group with similar body weight were selected to be slaughtered, and the longissimus dorsi (LD) muscle samples were collected for histological analysis and measurements of genes and proteins expression levels.Result: In the present study, the muscle fiber diameter and the area of Normal soil and Antibacterial soil group were significantly higher than No soil group (P < 0.05). The Normal soil significantly upregulated the gene expression of MyoG compared to No soil and Antibacterial soil groups (P < 0.05). The gene expression of CD36 and CPT-1 of Normal soil group was significantly lower than No soil group (P < 0.05), while HSL expression of Normal soil group was significantly higher than Antibacterial and No soil groups (P < 0.05). The MyHC I of Normal soil group was significantly higher than No soil group (P < 0.05), but the expression MyHC IIa was lower than No soil group (P < 0.05). The protein expression expressed the similar result with gene expression. In addition, the Normal soil significantly increased the AMPK and mTOR phosphorylation compared to No soil and Antibacterial soil groups (P < 0.05).Conclusion: These data suggest that early exposure to topsoil regulates the muscle fiber growth, modulates the expression pattern related to myogenesis, muscle fiber type, intramuscular fat metabolism, and increases the phosphorylation of mTOR and AMPK pathways.

scholarly journals Development of muscle fiber specialization in the rat hindlimb.

1981 ◽  
Vol 90 (1) ◽  
pp. 128-144 ◽  
Author(s):  
N A Rubinstein ◽  
A M Kelly
Keyword(s):  
Muscle Fiber ◽  
Muscle Development ◽  
Fiber Type ◽  
Muscle Cells ◽  
Postnatal Period ◽  
Type I ◽  
Fiber Types ◽  
Type Ii ◽  
Slow Myosin ◽  
Fast Myosin

The appearance of fast and slow fiber types in the distal hindlimb of the rat was investigated using affinity-purified antibodies specific to adult fast and slow myosins, two-dimensional electrophoresis of myosin light chains, and electron microscope examination of developing muscle cells. As others have noted, muscle histogenesis is not synchronous; rather, a series of muscle fiber generations occurs, each generation forming along the walls of the previous generation. At the onset of myotube formation on the 15th d of gestation, the antimyosin antibodies do not distinguish among fibers. All fibers react strongly with antibody to fast myosin but not with antibody to slow myosin. The initiation of fiber type differentiation can be detected in the 17-d fetus by a gradual increase in the binding of antibody to slow myosin in the primary, but not the secondary, generation myotubes. Moreover, neuromuscular contacts at this crucial time are infrequent, primitive, and restricted predominantly, but not exclusively, to the primary generation cells, the same cells which begin to bind large amounts of antislow myosin at this time. With maturation, the primary generation cells decrease their binding of antifast myosin and become type I fibers. Secondary generation cells are initially all primitive type II fibers. In future fast muscles the secondary generation cells remain type II, while in future slow muscles most of the secondary generation cells eventually change to type I over a prolonged postnatal period. We conclude that the temporal sequence of muscle development is fundamentally important in determining the genetic expression of individual muscle cells.

Characterization of Waldenström Macroglobulinemia Subtypes using Global Gene Expression Profiling.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 786-786
Author(s):  
Tae-Hoon Chung ◽  
Seungchan Kim ◽  
Angela S. Baker ◽  
Tammy Price-Troska ◽  
Ruifang Xu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Global Gene Expression ◽  
Suppressor Gene ◽  
Regulatory Control ◽  
Genomic Aberration ◽  
Global Gene Expression Profiling ◽  
High Level

Abstract Waldenström macroglobulinemia (WM) is a lymphoid neoplasm associated with accumulation of lymphoplasmacytic cells in the bone marrow and an elevated monoclonal IgM in the serum. Although the genetic and molecular mechanisms behind the pathogenesis of WM are not well understood, losses of the long arm of chromosome 6 have been found as the only recurrent genomic aberration. These deletions, mostly starting at 6q21, are observed in upwards of 50% of patients and involve the majority of the clonal cells. To better characterize pathologic gene expression signatures in different types of WM at the molecular level (6q deleted versus not), we examined gene expression level changes of more than 20000 human gene probes in bone marrow tissues of clinically proven WM patients. We used Affymetrix HG-U133A v2 chips (n = 24). Clonal cells were purified using a combination of anti-CD138 and anti-CD19 Miltenyi™ magnetic microbeads. Based on cIgM-FISH results, we classified samples into two groups - 6q normal (ND) group and 6q deletion (D) group. We then proceeded to identify genes that showed differential expression between the two groups. We selected 165 differentially expressed genes (DEG) using SAM, and underwent further investigation of biological annotations of them using Gene Ontology™ (GO) terms. Among165 DEG, only 32 showed high level of expression in ND group compared to D group while 133 showed high level of expression in D group. As expected, all genes that reside in 6q region showed under-expression in D group, constituting 53% (17 genes) of genes under-expressed in D group (32 genes). According to GO analysis, the 6q-deletion-induced under-expression affects many biological processes, and is associated with a transcriptional upregulation of downstream genetic cascades. This likely indicates release of regulatory control by a tumor suppressor gene. Genes involved in cell growth and maintenance, cell communication and morphogenesis are also over-expressed in D group. Interestingly, a gene that is involved in innate immune response and inflammatory response shows under-expression in D group but is not accounted for by other mechanisms. In similar vein, a gene that is involved in negative regulation of cytokine biosynthesis showed over-expression in D group. We think these transcriptional characteristics can provide basic framework for differentiating subtypes of WM and search for genes associated with WM pathogenesis

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