Electrophoretic and functional identification of two troponin C isoforms in toad skeletal muscle fibers

2006 ◽  
Vol 290 (2) ◽  
pp. C515-C523 ◽  
Author(s):  
Brett O'Connell ◽  
Ronnie Blazev ◽  
Gabriela M. M. Stephenson
Keyword(s):  
Cardiac Muscle ◽  
Striated Muscle ◽  
Muscle Fibers ◽  
Troponin C ◽  
The Other ◽  
Differential Sensitivity ◽  
Fiber Types ◽  
Functional Identification ◽  
Cane Toad ◽  
Fast Twitch

The differential sensitivity of frog twitch and slow-tonic fibers to Ca2+ and Sr2+ suggests that these two fiber types express different troponin C (TnC) isoforms. To date, only one TnC isoform from anurans (resembling the mammalian fast-twitch isoform) has been isolated and characterized. In this study, we examined the possibility that anuran striated muscle contains more than one TnC isoform. Toward this end, we determined the TnC isoform composition of 198 single fibers from the rectus abdominis of the cane toad (a mixed slow-tonic and twitch muscle) and of toad cardiac muscle using a method that enables the identification of TnC isoforms on the basis of the effect of Ca2+ on their electrophoretic mobility. The fibers were typed according to their myosin heavy chain (MHC) isoform composition. The data indicate that striated muscle of the cane toad contains two TnC isoforms, one of which (TnC-t) is present in all fibers displaying only twitch MHC isoforms and the other of which (TnC-T/c) is present in fibers displaying the tonic MHC isoform and in cardiac muscle. For a subpopulation of 15 fibers, the TnC isoform composition was also compared with Ca2+ and Sr2+ activation characteristics. Fibers containing the TnC-T/c isoform were ∼3-fold more sensitive to Ca2+, ∼40-fold more sensitive to Sr2+, and responded to a ∼4.6-fold broader range of [Ca2+] than did fibers containing the TnC-t isoform. The Ca2+ activation properties of toad fibers containing the TnC-T/c isoform appear to be consistent with the previously reported physiological characteristics of amphibian slow-tonic muscle fibers.

scholarly journals lncRNA-Six1 Is a Target of miR-1611 that Functions as a ceRNA to Regulate Six1 Protein Expression and Fiber Type Switching in Chicken Myogenesis

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 243 ◽  
Author(s):  
Manting Ma ◽  
Bolin Cai ◽  
Liang Jiang ◽  
Bahareldin Ali Abdalla ◽  
Zhenhui Li ◽  
...  
Keyword(s):  
Fiber Type ◽  
Muscle Fibers ◽  
Muscle Fiber Types ◽  
Fiber Types ◽  
Proliferation And Differentiation ◽  
Slow Twitch Muscle ◽  
Fast Twitch Muscle ◽  
Slow Twitch ◽  
Slow Twitch Fibers ◽  
Fast Twitch

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.

Comparison of Na+ currents from type IIa and IIb human intercostal muscle fibers

1993 ◽  
Vol 265 (1) ◽  
pp. C171-C177 ◽  
Author(s):  
R. L. Ruff ◽  
D. Whittlesey
Keyword(s):  
Skeletal Muscle ◽  
Voltage Dependence ◽  
Muscle Fibers ◽  
Fiber Types ◽  
Slow Inactivation ◽  
Intercostal Muscle ◽  
Fast Inactivation ◽  
Na Currents ◽  
The Difference ◽  
Fast Twitch

The voltage dependence and amplitude of Na+ currents (INa) were studied with the loose-patch voltage-clamp technique on 19 fast-twitch human intercostal skeletal muscle fibers at the endplate border and > 200 microns from the endplate (extrajunctional). The fibers were histochemically classified as fast-twitch oxidative-glycolytic (type IIa, n = 9) or fast-twitch glycolytic (type IIb, n = 10). The voltage dependence of activation and fast and slow inactivation of INa were similar for membrane patches recorded on the endplate border and on extrajunctional membrane for both fiber types. INa was about fivefold larger on the endplate border compared with extrajunctional membrane for both fiber types. Type IIb fibers had larger values of INa and manifest fast inactivation of INa at more negative potentials than type IIa fibers. The difference between type IIa and IIb fibers may enable IIb fibers to operate at higher firing frequencies for brief periods.

scholarly journals Comparative analysis of the transcriptomes of EDL, psoas, and soleus muscles from mice

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Pabodha Hettige ◽  
Uzma Tahir ◽  
Kiisa C. Nishikawa ◽  
Matthew J. Gage
Keyword(s):  
Skeletal Muscles ◽  
Striated Muscle ◽  
Fiber Type ◽  
Expression Patterns ◽  
Fiber Types ◽  
Muscle Adaptation ◽  
Myosin Heavy Chain Isoform ◽  
Genes Encoding ◽  
Slow Twitch ◽  
Fast Twitch

Abstract Background Individual skeletal muscles have evolved to perform specific tasks based on their molecular composition. In general, muscle fibers are characterized as either fast-twitch or slow-twitch based on their myosin heavy chain isoform profiles. This approach made sense in the early days of muscle studies when SDS-PAGE was the primary tool for mapping fiber type. However, Next Generation Sequencing tools permit analysis of the entire muscle transcriptome in a single sample, which allows for more precise characterization of differences among fiber types, including distinguishing between different isoforms of specific proteins. We demonstrate the power of this approach by comparing the differential gene expression patterns of extensor digitorum longus (EDL), psoas, and soleus from mice using high throughput RNA sequencing. Results EDL and psoas are typically classified as fast-twitch muscles based on their myosin expression pattern, while soleus is considered a slow-twitch muscle. The majority of the transcriptomic variability aligns with the fast-twitch and slow-twitch characterization. However, psoas and EDL exhibit unique expression patterns associated with the genes coding for extracellular matrix, myofibril, transcription, translation, striated muscle adaptation, mitochondrion distribution, and metabolism. Furthermore, significant expression differences between psoas and EDL were observed in genes coding for myosin light chain, troponin, tropomyosin isoforms, and several genes encoding the constituents of the Z-disk. Conclusions The observations highlight the intricate molecular nature of skeletal muscles and demonstrate the importance of utilizing transcriptomic information as a tool for skeletal muscle characterization.

Control of glycogen synthesis is shared between glucose transport and glycogen synthase in skeletal muscle fibers

2000 ◽  
Vol 278 (2) ◽  
pp. E234-E243 ◽  
Author(s):  
Iñaki Azpiazu ◽  
Jill Manchester ◽  
Alexander V. Skurat ◽  
Peter J. Roach ◽  
John C. Lawrence
Keyword(s):  
Skeletal Muscle ◽  
Glucose Transport ◽  
Glycogen Synthase ◽  
Glycogen Synthesis ◽  
Muscle Fibers ◽  
Fiber Types ◽  
Oxidative Potential ◽  
Glycogen Accumulation ◽  
Tibialis Muscle ◽  
Fast Twitch

The effects of transgenic overexpression of glycogen synthase in different types of fast-twitch muscle fibers were investigated in individual fibers from the anterior tibialis muscle. Glycogen synthase was severalfold higher in all transgenic fibers, although the extent of overexpression was twofold greater in type IIB fibers. Effects of the transgene on increasing glycogen and phosphorylase and on decreasing UDP-glucose were also more pronounced in type IIB fibers. However, in any grouping of fibers having equivalent malate dehydrogenase activity (an index of oxidative potential), glycogen was higher in the transgenic fibers. Thus increasing synthase is sufficient to enhance glycogen accumulation in all types of fast-twitch fibers. Effects on glucose transport and glycogen synthesis were investigated in experiments in which diaphragm, extensor digitorum longus (EDL), and soleus muscles were incubated in vitro. Transport was not increased by the transgene in any of the muscles. The transgene increased basal [14C]glucose into glycogen by 2.5-fold in the EDL, which is composed primarily of IIB fibers. The transgene also enhanced insulin-stimulated glycogen synthesis in the diaphragm and soleus muscles, which are composed of oxidative fiber types. We conclude that increasing glycogen synthase activity increases the rate of glycogen synthesis in both oxidative and glycolytic fibers, implying that the control of glycogen accumulation by insulin in skeletal muscle is distributed between the glucose transport and glycogen synthase steps.

Morphological Studies of Fiber Types of Striated Muscle Fibers of the Cremaster in the Guinea Pig

1981 ◽  
Vol 111 (3) ◽  
pp. 240-246 ◽  
Author(s):  
Jesús G. Ninomiya ◽  
Olga M. Echeverría ◽  
Gerardo H. Vázquez-Nin
Keyword(s):  
Guinea Pig ◽  
Striated Muscle ◽  
Muscle Fibers ◽  
Fiber Types ◽  
Morphological Studies ◽  
Striated Muscle Fibers

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

FEBS Letters ◽  
1986 ◽  
Vol 203 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Aravind Babu ◽  
Suzanne Pemrick ◽  
Jagdish Gulati
Keyword(s):  
Muscle Fibers ◽  
Troponin C ◽  
Fast Twitch Muscle ◽  
Fast Twitch

scholarly journals Myosin types and fiber types in cardiac muscle. I. Ventricular myocardium.

1981 ◽  
Vol 88 (1) ◽  
pp. 226-233 ◽  
Author(s):  
S Sartore ◽  
L Gorza ◽  
S Pierobon Bormioli ◽  
L Dalla Libera ◽  
S Schiaffino
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cardiac Muscle ◽  
Muscle Fibers ◽  
Ventricular Myocardium ◽  
Rabbit Heart ◽  
Fiber Types ◽  
Ventricular Muscle ◽  
The Right ◽  
Atrial Myosin

Antisera against bovine atrial myosin were raised in rabbits, purified by affinity chromatography, and absorbed with insolubilized ventricular myosin. Specific anti-bovine atrial myosin (anti-bAm) antibodies reacted selectively with atrial myosin heavy chains, as determined by enzyme immunoassay combined with SDS-gel electrophoresis. In direct and indirect immunofluorescence assay, anti-bAm was found to stain all atrial muscle fibers and a minor proportion of ventricular muscle fibers in the right ventricle of the bovine heart. In contrast, almost all muscle fibers in the left ventricle were unreactive. Purkinje fibers showed variable reactivity. In the rabbit heart, all atrial muscle fibers were stained by anti-bAm, whereas ventricular fibers showed a variable response in both the right and left ventricle, with a tendency for reactive fibers to be more numerous in the right ventricle and in subepicardial regions. Diversification of fiber types with respect to anti-bAm reactivity was found to occur during late stages of postnatal development in the rabbit heart and to be influenced by thyroid hormone. All ventricular muscle fibers became strongly reactive after thyroxine treatment, whereas they became unreactive or poorly reactive after propylthiouracil treatment. These findings are consistent with the existence of different ventricular isomyosins whose relative proportions can vary according to the thyroid state. Variations in ventricular isomyosin composition can account for the changes in myosin Ca2+-activated ATPase activity previously observed in cardiac muscle from hyper- and hypothyroid animals and may be responsible for the changes in the velocity of contraction of ventricular myocardium that occur under these conditions. The differential distribution of ventricular isomyosins in the normal heart suggests that fiber types with different contractile properties may coexist in the ventricular myocardium.

scholarly journals The effect of altered temperature on Ca2(+)-sensitive force in permeabilized myocardium and skeletal muscle. Evidence for force dependence of thin filament activation.

1990 ◽  
Vol 96 (6) ◽  
pp. 1221-1245 ◽  
Author(s):  
N K Sweitzer ◽  
R L Moss
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Thin Filament ◽  
Calcium Sensitivity ◽  
Differential Sensitivity ◽  
Fiber Types ◽  
Tension Development ◽  
Maximum Tension ◽  
Filament Activation ◽  
Muscle Types

The effect of changes in temperature on the calcium sensitivity of tension development was examined in permeabilized cellular preparations of rat ventricle and rabbit psoas muscle. Maximum force and Ca2+ sensitivity of force development increased with temperature in both muscle types. Cardiac muscle was more sensitive to changes in temperature than skeletal muscle in the range 10-15 degrees C. It was postulated that the level of thin filament activation may be decreased by cooling. To investigate this possibility, troponin C (TnC) was partially extracted from both muscle types, thus decreasing the level of thin filament activation independent of temperature and, at least in skeletal muscle fibers, decreasing cooperative activation of the thin filament as well. TnC extraction from cardiac muscle reduced the calcium sensitivity of tension less than did extraction of TnC from skeletal muscle. In skeletal muscle the midpoint shift of the tension-pCa curve with altered temperature was greater after TnC extraction than in control fibers. Calcium sensitivity of tension development was proportional to the maximum tension generated in cardiac or skeletal muscle under all conditions studied. Based on these results, we conclude that (a) maximum tension-generating capability and calcium sensitivity of tension development are related, perhaps causally, in fast skeletal and cardiac muscles, and (b) thin filament activation is less cooperative in cardiac muscle than in skeletal muscle, which explains the differential sensitivity of the two fiber types to temperature and TnC extraction. Reducing thin filament cooperativity in skeletal muscle by TnC extraction results in a response to temperature similar to that of control cardiac cells. This study provides evidence that force levels in striated muscle influence the calcium binding affinity of TnC.

Expression of the Na+/Ca2+exchanger in skeletal muscle

2001 ◽  
Vol 280 (1) ◽  
pp. C146-C154 ◽  
Author(s):  
Bodvaël Fraysse ◽  
Thierry Rouaud ◽  
Marie Millour ◽  
Josiane Fontaine-Pérus ◽  
Marie-France Gardahaut ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fibers ◽  
Cellular Level ◽  
Postnatal Life ◽  
Fiber Types ◽  
Developmentally Regulated ◽  
Protein Levels ◽  
Isoform Expression ◽  
Fast Twitch

The expression of the Na+/Ca2+ exchanger was studied in differentiating muscle fibers in rats. NCX1 and NCX3 isoform (Na+/Ca2+ exchanger isoform) expression was found to be developmentally regulated. NCX1 mRNA and protein levels peaked shortly after birth. Conversely, NCX3 isoform expression was very low in muscles of newborn rats but increased dramatically during the first 2 wk of postnatal life. Immunocytochemical analysis showed that NCX1 was uniformly distributed along the sarcolemmal membrane of undifferentiated rat muscle fibers but formed clusters in T-tubular membranes and sarcolemma of adult muscle. NCX3 appeared to be more uniformly distributed along the sarcolemma and inside myoplasm. In the adult, NCX1 was predominantly expressed in oxidative (type 1 and 2A) fibers of both slow- and fast-twitch muscles, whereas NCX3 was highly expressed in fast glycolytic (2B) fibers. NCX2 was expressed in rat brain but not in skeletal muscle. Developmental changes in NCX1 and NCX3 as well as the distribution of these isoforms at the cellular level and in different fiber types suggest that they may have different physiological roles.

Absence of regional differences in the size and oxidative capacity of diaphragm muscle fibers

1987 ◽  
Vol 63 (3) ◽  
pp. 1076-1082 ◽  
Author(s):  
G. C. Sieck ◽  
R. D. Sacks ◽  
C. E. Blanco
Keyword(s):  
Muscle Fibers ◽  
Continuous Distribution ◽  
Oxidative Capacity ◽  
Cross Sectional Area ◽  
Diaphragm Muscle ◽  
Type I ◽  
Fiber Types ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fast Twitch

The oxidative capacity and cross-sectional area of muscle fibers were compared between the costal and crural regions of the cat diaphragm and across the abdominal-thoracic extent of the muscle. Succinate dehydrogenase (SDH) activity of individual fibers was quantified using a microphotometric procedure implemented on an image-processing system. In both costal and crural regions, population distributions of SDH activities were unimodal for both type I and II fibers. The continuous distribution of SDH activities for type II fibers indicated that no clear threshold exists for the subclassification of fibers based on differences in oxidative capacity (e.g., the classification of fast-twitch glycolytic and fast-twitch oxidative glycolytic fiber types). No differences in either SDH activity or cross-sectional area were noted between fiber populations of the costal and crural regions. Differences in SDH activity and cross-sectional area were noted, however, between fiber populations located on the abdominal and thoracic sides of the costal region. Both type I and II fibers on the abdominal side of the costal diaphragm were larger and more oxidative than comparable fibers on the thoracic side.

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