<div>High-speed jaw-opening exercise in training suprahyoid fast-twitch muscle fibers</div>

Emerging studies indicate important roles for non-coding RNAs (ncRNAs) as essential regulators in myogenesis, but relatively less is known about their function. In our previous study, we found that lncRNA-Six1 can regulate Six1 in cis to participate in myogenesis. Here, we studied a microRNA (miRNA) that is specifically expressed in chickens (miR-1611). Interestingly, miR-1611 was found to contain potential binding sites for both lncRNA-Six1 and Six1, and it can interact with lncRNA-Six1 to regulate Six1 expression. Overexpression of miR-1611 represses the proliferation and differentiation of myoblasts. Moreover, miR-1611 is highly expressed in slow-twitch fibers, and it drives the transformation of fast-twitch muscle fibers to slow-twitch muscle fibers. Together, these data demonstrate that miR-1611 can mediate the regulation of Six1 by lncRNA-Six1, thereby affecting proliferation and differentiation of myoblasts and transformation of muscle fiber types.

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Ultrastructural Characteristics of Slow and fast twitch Muscle Fibers of Rats after a Forced Swimming Cycle against a Background of Introduction of Green Tea Extract and Ammonium Salts

Cell and Tissue Biology ◽

10.1134/s1990519x20010022 ◽

2020 ◽

Vol 14 (1) ◽

pp. 65-73

Author(s):

E. V. Baidyuk ◽

V. E. Sobolev ◽

E. A. Korf ◽

I. V. Mindukshev ◽

A. I. Krivchenko ◽

...

Keyword(s):

Green Tea ◽

Muscle Fibers ◽

Green Tea Extract ◽

Forced Swimming ◽

Ammonium Salts ◽

Fast Twitch Muscle ◽

Ultrastructural Characteristics ◽

Tea Extract ◽

Fast Twitch

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A two-faced cysteine residue modulates skeletal muscle contraction. Focus on “S-nitrosylation and S-glutathionylation of Cys134 on troponin I have opposing competitive actions on Ca2+ sensitivity in rat fast-twitch muscle fibers

AJP Cell Physiology ◽

10.1152/ajpcell.00009.2017 ◽

2017 ◽

Vol 312 (3) ◽

pp. C314-C315 ◽

Cited By ~ 5

Author(s):

Josine M. de Winter ◽

Coen A. C. Ottenheijm

Keyword(s):

Skeletal Muscle ◽

Muscle Contraction ◽

Troponin I ◽

Muscle Fibers ◽

Cysteine Residue ◽

Skeletal Muscle Contraction ◽

Fast Twitch Muscle ◽

Competitive Actions ◽

Fast Twitch

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Ca2+ activation of troponin C-extracted vertebrate striated fast-twitch muscle fibers

FEBS Letters ◽

10.1016/0014-5793(86)81428-4 ◽

1986 ◽

Vol 203 (1) ◽

pp. 20-24 ◽

Cited By ~ 12

Author(s):

Aravind Babu ◽

Suzanne Pemrick ◽

Jagdish Gulati

Keyword(s):

Muscle Fibers ◽

Troponin C ◽

Fast Twitch Muscle ◽

Fast Twitch

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Size and Proportions of Slow-Twitch and Fast-Twitch Muscle Fibers in Human Costal Diaphragm

BioMed Research International ◽

10.1155/2016/5946520 ◽

2016 ◽

Vol 2016 ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

Marija Meznaric ◽

Erika Cvetko

Keyword(s):

Vastus Lateralis ◽

Muscle Fibers ◽

Hybrid Fibers ◽

Cross Sectional ◽

Myosin Heavy Chain Isoform ◽

Diaphragmatic Muscle ◽

Fast Twitch Muscle ◽

The Mean ◽

Slow Twitch ◽

Fast Twitch

Smaller diaphragmatic motor unit potentials (MUPs) compared to MUPs of limb muscles lead to the hypothesis that diaphragmatic muscle fibers, being the generators of MUPs, might be also smaller. We compared autopsy samples of costal diaphragm and vastus lateralis of healthy men with respect to fibers’ size and expression of slow myosin heavy chain isoform (MyHC-1) and fast 2A isoform (MyHC-2A). Diaphragmatic fibers were smaller than fibers in vastus lateralis with regard to the mean minimal fiber diameter of slow-twitch (46.8 versus 72.2 μm,p<0.001), fast-twitch (45.1 versus 62.4 μm,p<0.001), and hybrid fibers (47.3 versus 65.0 μm,p<0.01) as well as to the mean fiber cross-sectional areas of slow-twitch (2376.0 versus 5455.9 μm2,p<0.001), fast-twitch (2258.7 versus 4189.7 μm2,p<0.001), and hybrid fibers (2404.4 versus 4776.3 μm2,p<0.01). The numerical proportion of slow-twitch fibers was higher (50.2 versus 36.3%,p<0.01) in costal diaphragm and the numerical proportion of fast-twitch fibers (47.2 versus 58.7%,p<0.01) was lower. The numerical proportion of hybrid fibers did not differ. Muscle fibers of costal diaphragm have specific characteristics which support increased resistance of diaphragm to fatigue.

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Prolonged contraction-relaxation cycle of fast-twitch muscles in parvalbumin knockout mice

AJP Cell Physiology ◽

10.1152/ajpcell.1999.276.2.c395 ◽

1999 ◽

Vol 276 (2) ◽

pp. C395-C403 ◽

Cited By ~ 145

Author(s):

B. Schwaller ◽

J. Dick ◽

G. Dhoot ◽

S. Carroll ◽

G. Vrbova ◽

...

Keyword(s):

Knockout Mice ◽

Calcium Binding ◽

Muscle Fibers ◽

Relaxation Cycle ◽

Single Twitch ◽

Intracellular Ca ◽

Fast Twitch Muscle ◽

High Concentrations ◽

Time Required ◽

Fast Twitch

The calcium-binding protein parvalbumin (PV) occurs at high concentrations in fast-contracting vertebrate muscle fibers. Its putative role in facilitating the rapid relaxation of mammalian fast-twitch muscle fibers by acting as a temporary buffer for Ca2+ is still controversial. We generated knockout mice for PV (PV −/−) and compared the Ca2+ transients and the dynamics of contraction of their muscles with those from heterozygous (PV +/−) and wild-type (WT) mice. In the muscles of PV-deficient mice, the decay of intracellular Ca2+ concentration ([Ca2+]i) after 20-ms stimulation was slower compared with WT mice and led to a prolongation of the time required to attain peak twitch tension and to an extension of the half-relaxation time. The integral [Ca2+]iin muscle fibers of PV −/− mice was higher and consequently the force generated during a single twitch was ∼40% greater than in PV +/− and WT animals. Acceleration of the contraction-relaxation cycle of fast-twitch muscle fibers by PV may confer an advantage in the performance of rapid, phasic movements.

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