scholarly journals Skeletal muscle fiber size and fiber type distribution in human cancer: Effects of weight loss and relationship to physical function

2016 ◽  
Vol 35 (6) ◽  
pp. 1359-1365 ◽  
Author(s):  
Michael J. Toth ◽  
Damien M. Callahan ◽  
Mark S. Miller ◽  
Timothy W. Tourville ◽  
Sarah B. Hackett ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Weight Loss ◽  
Physical Function ◽  
Muscle Fiber ◽  
Human Cancer ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Type Distribution ◽  
Fiber Size ◽  
Fiber Type Distribution

scholarly journals High-Throughput Muscle Fiber Typing From RNA Sequencing Data

2021 ◽  
Author(s):  
Nikolay Oskolkov ◽  
Malgorzata Santel ◽  
Ola Ekström ◽  
Gray J. Camp ◽  
Eri Miyamoto-Mikami ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Rna Sequencing ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Fiber Types ◽  
Sequencing Data ◽  
Gene Markers ◽  
Type Distribution ◽  
Fiber Type Distribution

Abstract BACKGROUND: Skeletal muscle fiber type distribution has implications for human health, muscle function and performance. This knowledge has been gathered using labor-intensive and costly methodology that limited these studies. Here we present a method based on muscle tissue RNA sequencing data (totRNAseq) to estimate the distribution of skeletal muscle fiber types from frozen human samples, allowing for a larger number of individuals to be tested.METHODS: By using single-nuclei RNA sequencing (snRNAseq) data as a reference, cluster expression signatures were produced by averaging gene expression of cluster gene markers and then applying these to totRNAseq data and inferring muscle fiber nuclei type via linear matrix decomposition. This estimate was then compared with fiber type distribution measured by ATPase staining or myosin heavy chain protein isoform distribution of 62 muscle samples in two independent cohorts (n = 39 and 22).RESULTS: The correlation between the sequencing-based method and the other two were rATPas = 0.65 [0.46 – 0.84], [95% CI] and rmyosin = 0.80 [0.71 – 0.89], with p = 7.96 x 10-6 and 8.06 x 10-6 respectively. The deconvolution inference of fiber type composition was accurate even for very low totRNAseq sequencing depths, i.e., down to an average of ~5.000 paired-end reads.CONCLUSIONS: This new method (https://github.com/OlaHanssonLab/PredictFiberType) consequently allows for measurement of fiber type distribution of a larger number of samples using totRNAseq in a cost and labor-efficient way. For the first time, it is now feasible to study the association between fiber type distribution and e.g. health outcomes in large well-powered studies.

scholarly journals Prolonged C2 spinal hemisection-induced inactivity reduces diaphragm muscle specific force with modest, selective atrophy of type IIx and/or IIb fibers

2013 ◽  
Vol 114 (3) ◽  
pp. 380-386 ◽  
Author(s):  
Carlos B. Mantilla ◽  
Sarah M. Greising ◽  
Wen-Zhi Zhan ◽  
Yasin B. Seven ◽  
Gary C. Sieck
Keyword(s):  
Spinal Cord ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Diaphragm Muscle ◽  
Emg Activity ◽  
Type I ◽  
Specific Force ◽  
Type Distribution ◽  
Fiber Size ◽  
Fiber Type Distribution

The diaphragm muscle (DIAm) is critically responsible for sustaining ventilation. Previously we showed in a commonly used model of spinal cord injury, unilateral spinal cord hemisection at C2 (SH), that there are minimal changes to muscle fiber cross-sectional area (CSA) and fiber type distribution following 14 days of SH-induced ipsilateral DIAm inactivity. In the present study, effects of long-term SH-induced inactivity on DIAm fiber size and force were examined. We hypothesized that prolonged inactivity would not result in substantial DIAm atrophy or force loss. Adult rats were randomized to control or SH groups ( n = 34 total). Chronic bilateral DIAm electromyographic (EMG) activity was monitored during resting breathing. Minimal levels of spontaneous recovery of ipsilateral DIAm EMG activity were evident in 42% of SH rats (<25% of preinjury root mean square amplitude). Following 42 days of SH, DIAm specific force was reduced 39%. There was no difference in CSA for type I or IIa DIAm fibers in SH rats compared with age, weight-matched controls (classification based on myosin heavy chain isoform expression). Type IIx and/or IIb DIAm fibers displayed a modest 20% reduction in CSA ( P < 0.05). Overall, there were no differences in the distribution of fiber types or the contribution of each fiber type to the total DIAm CSA. These data indicate that reduced specific force following prolonged inactivity of the DIAm is associated with modest, fiber type selective adaptations in muscle fiber size and fiber type distribution.

Genetic effects in human skeletal muscle fiber type distribution and enzyme activities

1986 ◽  
Vol 64 (9) ◽  
pp. 1245-1251 ◽  
Author(s):  
C. Bouchard ◽  
J. A. Simoneau ◽  
G. Lortie ◽  
M. R. Boulay ◽  
M. Marcotte ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Enzyme Activities ◽  
Fiber Type ◽  
Genetic Effect ◽  
Genetic Effects ◽  
Type I ◽  
Type Distribution ◽  
Fiber Type Distribution ◽  
Mz Twins

The purpose of the study was to estimate the genetic effect for skeletal muscle characteristics using pairs of nontwin brothers (n = 32), dizygotic (DZ) twins (n = 26), and monozygotic (MZ) twins (n = 35). They were submitted to a needle biopsy of the vastus lateralis for the determination of fiber type distribution (I, IIa, IIb) and the following enzymes were assayed for maximal activity: creatine kinase, hexokinase, phosphofructokinase (PFK), lactate dehydrogenase, malate dehydrogenase, 3-hydroxyacyl CoA dehydrogenase, and oxoglutarate dehydrogenase (OGDH). For the percentage of type I fibers, intraclass correlations were 0.33 (p < 0.05), 0.52 (p < 0.01), and 0.55 (p < 0.01) in brothers and DZ and MZ twins, respectively. MZ twins exhibited significant within-pair resemblance for all enzyme activities (0.30 ≤ r ≤ 0.68). In spite of these correlations, genetic analyses performed with the twin data alone indicated that there was no significant genetic effect for muscle fiber type I, IIa, and IIb distribution and fiber areas. Although there were significant correlations in MZ twins for all muscle enzyme activities, the often nonsignificant intraclass coefficients found in brothers and DZ twins suggest that variations in enzyme activities are highly related to common environmental conditions and nongenetic factors. However, genetic factors appear to be involved in the variation of regulatory enzymes of the glycolytic (PFK) and citric acid cycle (OGDH) pathways and in the variation of the oxidative to glycolytic activity ratio (PFK/OGDH ratio). Data show that these genetic effects reach only about 25–50% of the total phenotypic variation when data are adjusted for age and sex differences.

The menopausal transition does not influence skeletal muscle capillary growth in response to cycle training in women

2021 ◽  
Author(s):  
Jorge Perez-Gomez ◽  
Nicolai Rytter ◽  
Camilla M. Mandrup ◽  
Jon Egelund ◽  
Bente Stallknecht ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Type Distribution ◽  
Capillary Growth ◽  
Menopausal Women ◽  
Fiber Type Distribution ◽  
Cycle Training ◽  
Post Menopausal

The influence of the menopausal transition, with a consequent loss of oestrogen, on capillary growth in response to exercise training remains unknown. In the present study, we evaluated the effect of a period of intense endurance training on skeletal muscle angiogenesis in late pre-menopausal and recently post-menopausal women with an age difference of <4 years. Skeletal muscle biopsies were obtained from the thigh muscle prior to and after 12 weeks of intense aerobic cycle training, and analyzed for capillarization, fiber type distribution and content of vascular endothelial growth factor (VEGF). At baseline, there was no difference in capillary per fiber ratio (C:F; 1.41 ± 0.22 vs 1.40 ± 0.30), capillary density (CD; 305±61 vs 336±52 mm2), muscle fiber area (MFA) or percentage distribution of muscle fiber type I (47.3±10.1 vs 49.3±15.1 %) and type II (52.7±10.1 vs 50.7±15.1%) between the pre- and post-menopausal women. The training period resulted in a similar increase in C:F in pre- and post-menopausal women (by 9.2 vs 12.1 %, respectively) and CD (by 6.9 vs 8.9 %, respectively), whereas MFA and fiber type distribution remained unaltered. Skeletal muscle VEGF protein content was similar between groups at baseline and increased to a similar extent with training (by 21.1 vs 27.2 %, respectively) in the pre- and post-menopausal women. In conclusion, the loss of oestrogen per se at menopause does not influence the capillary growth response to intense aerobic exercise training.

scholarly journals MyoSight—semi-automated image analysis of skeletal muscle cross sections

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lyle W. Babcock ◽  
Amy D. Hanna ◽  
Nadia H. Agha ◽  
Susan L. Hamilton
Keyword(s):  
Skeletal Muscle ◽  
Image Analysis ◽  
Cross Sections ◽  
Fiber Type ◽  
Sectional Area ◽  
Cross Sectional ◽  
Type Distribution ◽  
Central Nuclei ◽  
Fiber Size ◽  
Fiber Type Distribution

Abstract Background Manual analysis of cross-sectional area, fiber-type distribution, and total and centralized nuclei in skeletal muscle cross sections is tedious and time consuming, necessitating an accurate, automated method of analysis. While several excellent programs are available, our analyses of skeletal muscle disease models suggest the need for additional features and flexibility to adequately describe disease pathology. We introduce a new semi-automated analysis program, MyoSight, which is designed to facilitate image analysis of skeletal muscle cross sections and provide additional flexibility in the analyses. Results We describe staining and imaging methods that generate high-quality images of immunofluorescent-labelled cross sections from mouse skeletal muscle. Using these methods, we can analyze up to 5 different fluorophores in a single image, allowing simultaneous analyses of perinuclei, central nuclei, fiber size, and fiber-type distribution. MyoSight displays high reproducibility among users, and the data generated are in close agreement with data obtained from manual analyses of cross-sectional area (CSA), fiber number, fiber-type distribution, and number and localization of myonuclei. Furthermore, MyoSight clearly delineates changes in these parameters in muscle sections from a mouse model of Duchenne muscular dystrophy (mdx). Conclusions MyoSight is a new program based on an algorithm that can be optimized by the user to obtain highly accurate fiber size, fiber-type identification, and perinuclei and central nuclei per fiber measurements. MyoSight combines features available separately in other programs, is user friendly, and provides visual outputs that allow the user to confirm the accuracy of the analyses and correct any inaccuracies. We present MyoSight as a new program to facilitate the analyses of fiber type and CSA changes arising from injury, disease, exercise, and therapeutic interventions.

Skeletal Muscle Fiber Type, Fiber Size, and Capillary Supply in Elite Soccer Players

1990 ◽  
Vol 11 (02) ◽  
pp. 99-102 ◽  
Author(s):  
W. Kuzon ◽  
J. Rosenblatt ◽  
S. Huebel ◽  
P. Leatt ◽  
M. Plyley ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Fiber Type ◽  
Skeletal Muscle Fiber ◽  
Muscle Fiber Type ◽  
Soccer Players ◽  
Capillary Supply ◽  
Fiber Size ◽  
Type Fiber
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