scholarly journals Expression of the Skeletal Calsequestrin Isoform in Normal and Regenerated Skeletal Muscles and in the Hearts of Rats With Altered Thyroid Status

2012 ◽  
pp. 575-586 ◽  
Author(s):  
T. SOUKUP ◽  
V. SULIMENKO ◽  
V. MARKOVÁ ◽  
K. KOPECKÁ ◽  
G. ZACHAŘOVÁ ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscles ◽  
Fiber Type ◽  
Mrna Levels ◽  
Left Heart ◽  
Thyroid Status ◽  
Type Composition ◽  
Slow Type ◽  
Old Rats

We have investigated expression of skeletal calsequestrin (CSQ1) and fiber type composition in normal and regenerated fast and slow skeletal muscles and in the left heart ventricles of euthyroid (EU), hypothyroid (HY) and hyperthyroid (TH) adult inbred Lewis strain rats. The CSQ1 level was determined by SDS-PAGE followed by Western blot analysis. CSQ1 gene expression was assessed using reverse transcription and subsequent real time polymerase chain reaction. Muscle regeneration was achieved by intramuscular grafting of either soleus or extensor digitorum longus (EDL) from 3- to 4-week-old rats to either EDL or soleus muscle of 2-month-old rats. The fiber type composition was assessed by a stereological method applied to stained muscle cross sections. We found that the protein and mRNA levels for CSQ1 were highest in the EDL muscle, the relative CSQ1 protein levels in the soleus muscle were two times lower and the transcript levels more than 5 times lower compared to the EDL. In the left heart ventricle, protein isoform and CSQ1 transcript were also present, although at protein level, CSQ1 was hardly detectable. TH status increased and HY status decreased the expression of CSQ1 in the EDL, but its relative levels in the soleus and in the heart did not change. The regenerated soleus transplanted into EDL, as well as EDL transplanted into soleus exhibited protein and mRNA levels of CSQ1 corresponding to the host muscle and not to the graft source. TH status increased the percentages of the fastest 2X/D and 2B fibers at the expense of slow type 1 and fast 2A fibers in the EDL and that of fast 2A fibers in the soleus at the expense of slow type 1 fibers. HY status led to converse fiber type changes. We suggest that the observed changes in CSQ1 levels in TH and HY compared to EU rats can be related to fiber type changes caused by alteration of the thyroid status rather than to the direct effect of thyroid hormones on CSQ1 gene expression.

scholarly journals Individual, age and sex differences in fiber type composition of slow and fast muscles of adult Lewis rats: comparison with other rat strains

2010 ◽  
pp. 783-801
Author(s):  
P Novák ◽  
G Zachařová ◽  
T Soukup
Keyword(s):  
Soleus Muscle ◽  
Fiber Type ◽  
Rat Strains ◽  
Lewis Rats ◽  
Fiber Type Composition ◽  
Type Composition ◽  
Significant Difference ◽  
Slow Type ◽  
Edl Muscle

We analyzed fiber type composition of soleus and extensor digitorum longus (EDL) muscles of 3- to 19-month-old male and female inbred Lewis rats using histochemical demonstration of mATPase activity. The rats were divided into four groups of the mean age of 3, 6, 9 and 14 months. We found that the soleus muscle of 3-month-old rats contained significantly more of fast 2A fibers and less of slow type 1 fibers compared to older rats, while no significant difference was found between female and male rats at any age group. In contrast, we found no significant difference in the EDL fiber type composition among the age groups, but we found that the EDL muscle of female rats contained significantly less 2A fibers and more 2B fibers than that of male animals. Our results thus revealed an age difference in the soleus muscle and a sex difference in the EDL muscle among postnatal Lewis rats. The number of slow type 1 fibers in the soleus muscle varied between 87 and 100 % and that of 2A fibers between 13 and 0 %. In the EDL the percentage of type 1 fibers varied between 2.6 and 8.7 %, that of 2A fibers between 12.6 and 25.8 % and that of 2B fibers between 70.4 and 81.6 %. Both muscles thus exhibited a considerable degree of variability among individual animals even in the same age group. Furthermore, a comparison of the Lewis rats with literature data of other rat strains showed that the number of fast 2A fibers in the soleus muscle of 4-month-old and older animals decreased in this order: SHR > Lister Hooded > Fisher 344 > SpragueDawley > Wistar > WBN/Kob > Lewis strain, being almost 20 % in the SHR and less than 2 % in the Lewis rats. In contrast, the “fastest” composition (judged according to the percentage of the fastest 2B fibers) of the EDL muscle was demonstrated by Lewis, Wistar and Fisher 344 rats (about 75 %), while Sprague-Dawley and WBN/Kob rats contained only about 50 % of 2B fibers. The percentage of slow type 1 fibers in the EDL was low in all strains (about 5 %). Our results thus show that the individual, age and sex as well as inter-strain differences in muscle fiber type composition should not be ignored when comparing results of different studies. We also demonstrated that the inbred Lewis strain appears to have more “specialized” muscle composition, as its soleus is the “slowest” and its EDL is the “fastest” among the routinely used rat strains.

scholarly journals Weaning affects lipoprotein lipase activity and gene expression in adipose tissues and in masseter but not in other muscles of the calf

2001 ◽  
Vol 86 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Jean-François Hocquette ◽  
Benoît Graulet ◽  
Michel Vermorel ◽  
Dominique Bauchart
Keyword(s):  
Gene Expression ◽  
Lipoprotein Lipase ◽  
Skeletal Muscles ◽  
Contractile Activity ◽  
Net Energy ◽  
Mrna Levels ◽  
Mammal Species ◽  
Adipose Tissues ◽  
Net Energy Intake ◽  
Rate Limiting

The nutritional and physiological modifications that occur during the weaning period induce adaptations of tissue metabolism in all mammal species. Among the adaptations due to weaning in ruminants, the regulation of lipoprotein lipase (LPL) activity, one of the rate-limiting steps of fatty acid utilization by tissues, was still unknown. The present study aimed at comparing LPL activity and gene expression in the heart, seven skeletal muscles and three adipose tissue sites between two groups of seven preruminant (PR) or ruminant (R) calves having a similar age (170 d), similar empty body weight (194 kg) at slaughter, and similar net energy intake from birth onwards. Triacylglycerol content of adipose tissues was 16 % lower in R than in PR calves, (P<0·01). This could be partly the result from a lower LPL activity (-57 %, P<0·01). LPL mRNA levels were also lower in R calves (-48 % to -68 %, P<0·01) suggesting a pretranslational regulation of LPL activity. Activity and mRNA levels of LPL did not differ significantly in the heart and skeletal muscles except in the masseter in which LPL activity and mRNA levels were higher (+50 % and +120 % respectively, P<0·01) in the R calves. Regulation of LPL in masseter could be explained by the high contractile activity of this muscle after weaning due to solid food chewing. In conclusion, weaning in the calf affects LPL activity and expression in adipose tissues, but not in skeletal muscles except the masseter.

A calcineurin- and NFAT-dependent pathway regulates Myf5 gene expression in skeletal muscle reserve cells

2001 ◽  
Vol 114 (2) ◽  
pp. 303-310 ◽  
Author(s):  
B.B. Friday ◽  
G.K. Pavlath
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Satellite Cell ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Fiber Type ◽  
Calcium Ionophore ◽  
Cell Populations ◽  
Mrna Levels ◽  
Dependent Pathway

Myf5 is a member of the muscle regulatory factor family of transcription factors and plays an important role in the determination, development, and differentiation of skeletal muscle. However, factors that regulate the expression and activity of Myf5 itself are not well understood. Recently, a role for the calcium-dependent phosphatase calcineurin was suggested in three distinct pathways in skeletal muscle: differentiation, hypertrophy, and fiber-type determination. We propose that one downstream target of calcineurin and the calcineurin substrate NFAT in skeletal muscle is regulation of Myf5 gene expression. For these studies, we used myotube cultures that contain both multinucleated myotubes and quiescent, mononucleated cells termed ‘reserve’ cells, which share many characteristics with satellite cells. Treatment of such myotube cultures with the calcium ionophore ionomycin results in an approximately 4-fold increase in Myf5 mRNA levels, but similar effects are not observed in proliferating myoblast cultures indicating that Myf5 is regulated by different pathways in different cell populations. The increase in Myf5 mRNA levels in myotube cultures requires the activity of calcineurin and NFAT, and can be specifically enhanced by overexpressing the NFATc isoform. We used immunohistochemical analyses and fractionation of the cell populations to demonstrate that the calcium regulated expression of Myf5 occurs in the mononucleated reserve cells. We conclude that Myf5 gene expression is regulated by a calcineurin- and NFAT-dependent pathway in the reserve cell population of myotube cultures. These results may provide important insights into the molecular mechanisms responsible for satellite cell activation and/or the renewal of the satellite cell pool following activation and proliferation.

Na+-K+-ATPase properties in rat heart and skeletal muscle 3 mo after coronary artery ligation

2005 ◽  
Vol 99 (2) ◽  
pp. 656-664 ◽  
Author(s):  
D. J. Barr ◽  
H. J. Green ◽  
D. S. Lounsbury ◽  
J. W. E. Rush ◽  
J. Ouyang
Keyword(s):  
Coronary Artery ◽  
Skeletal Muscles ◽  
Left Main Coronary Artery ◽  
Fiber Type ◽  
Coronary Artery Ligation ◽  
Ouabain Binding ◽  
Artery Ligation ◽  
Adult Rats ◽  
Type Composition ◽  
Phosphatase Assay

This study was designed to determine whether chronic heart failure (CHF) results in changes in Na+-K+-ATPase properties in heart and skeletal muscles of different fiber-type composition. Adult rats were randomly assigned to a control (Con; n = 8) or CHF ( n = 8) group. CHF was induced by ligation of the left main coronary artery. Examination of Na+-K+-ATPase activity (means ± SE) 12 wk after the ligation measured, using the 3- O-methylfluorescein phosphatase assay (3- O-MFPase), indicated higher ( P < 0.05) levels in soleus (Sol) (250 ± 13 vs. 179 ± 18 nmol·mg protein−1·h−1) and lower ( P < 0.05) levels in diaphragm (Dia) (200 ± 12 vs. 272 ± 27 nmol·mg protein−1·h−1) and left ventricle (LV) (760 ± 62 vs. 992 ± 16 nmol·mg protein−1·h−1) in CHF compared with Con, respectively. Na+-K+-ATPase protein content, measured by the [3H]ouabain binding technique, was higher ( P < 0.05) in white gastrocnemius (WG) (166 ± 12 vs. 135 ± 7.6 pmol/g wet wt) and lower ( P < 0.05) in Sol (193 ± 20 vs. 260 ± 8.6 pmol/g wet wt) and LV (159 ± 10 vs. 221 ± 10 pmol/g wet wt) in CHF compared with Con, respectively. Isoform content in CHF, measured by Western blot techniques, showed both increases (WG; P < 0.05) and decreases (Sol; P < 0.05) in α1. For α2, only increases [red gastrocnemius (RG), Sol, and Dia; P < 0.05] occurred. The β2-isoform was decreased (LV, Sol, RG, and WG; P < 0.05) in CHF, whereas the β1 was both increased (WG and Dia; P < 0.05) and decreased (Sol and LV; P < 0.05). For β3, decreases ( P < 0.05) in RG were observed in CHF, whereas no differences were found in Sol and WG between CHF and Con. It is concluded that CHF results in alterations in Na+-K+-ATPase that are muscle specific and property specific. Although decreases in Na+-K+-ATPase content would appear to explain the lower 3- O-MFPase in the LV, such does not appear to be the case in skeletal muscles where a dissociation between these properties was observed.

scholarly journals Obesity-induced discrepancy between contractile and metabolic phenotypes in slow- and fast-twitch skeletal muscles of female obese Zucker rats

2017 ◽  
Vol 123 (1) ◽  
pp. 249-259 ◽  
Author(s):  
Luz M. Acevedo ◽  
Ana I. Raya ◽  
Rafael Ríos ◽  
Escolástico Aguilera-Tejero ◽  
José-Luis L. Rivero
Keyword(s):  
Muscle Mass ◽  
Skeletal Muscles ◽  
Fiber Type ◽  
Succinic Dehydrogenase ◽  
Zucker Rats ◽  
Fiber Types ◽  
Type Composition ◽  
Obese Zucker Rats ◽  
And Function ◽  
Fast Twitch

A clear picture of skeletal muscle adaptations to obesity and related comorbidities remains elusive. This study describes fiber-type characteristics (size, proportions, and oxidative enzyme activity) in two typical hindlimb muscles with opposite structure and function in an animal model of genetic obesity. Lesser fiber diameter, fiber-type composition, and histochemical succinic dehydrogenase activity (an oxidative marker) of muscle fiber types were assessed in slow (soleus)- and fast (tibialis cranialis)-twitch muscles of obese Zucker rats and compared with age (16 wk)- and sex (females)-matched lean Zucker rats ( n = 16/group). Muscle mass and lesser fiber diameter were lower in both muscle types of obese compared with lean animals even though body weights were increased in the obese cohort. A faster fiber-type phenotype also occurred in slow- and fast-twitch muscles of obese rats compared with lean rats. These adaptations were accompanied by a significant increment in histochemical succinic dehydrogenase activity of slow-twitch fibers in the soleus muscle and fast-twitch fiber types in the tibialis cranialis muscle. Obesity significantly increased plasma levels of proinflammatory cytokines but did not significantly affect protein levels of peroxisome proliferator-activated receptors PPARγ or PGC1α in either muscle. These data demonstrate that, in female Zucker rats, obesity induces a reduction of muscle mass in which skeletal muscles show a diminished fiber size and a faster and more oxidative phenotype. It was noteworthy that this discrepancy in muscle's contractile and metabolic features was of comparable nature and extent in muscles with different fiber-type composition and antagonist functions. NEW & NOTEWORTHY This study demonstrates a discrepancy between morphological (reduced muscle mass), contractile (shift toward a faster phenotype), and metabolic (increased mitochondrial oxidative enzyme activity) characteristics in skeletal muscles of female Zucker fatty rats. It is noteworthy that this inconsistency was comparable (in nature and extent) in muscles with different structure and function.

Downhill Running Excessive Training Inhibits Hypertrophy in Mice Skeletal Muscles with Different Fiber Type Composition

2015 ◽  
Vol 231 (5) ◽  
pp. 1045-1056 ◽  
Author(s):  
Alisson L. da Rocha ◽  
Bruno C. Pereira ◽  
José R. Pauli ◽  
Claudio T. de Souza ◽  
Giovana R. Teixeira ◽  
...  
Keyword(s):  
Skeletal Muscles ◽  
Fiber Type ◽  
Fiber Type Composition ◽  
Downhill Running ◽  
Type Composition

Parvalbumin content in striated muscles of the common shrew (Sorex araneus)

1998 ◽  
Vol 76 (12) ◽  
pp. 2194-2199 ◽  
Author(s):  
J Savolainen ◽  
M Vornanen
Keyword(s):  
Relaxation Time ◽  
Skeletal Muscles ◽  
Gastrocnemius Muscle ◽  
Fiber Type ◽  
Common Shrew ◽  
Isometric Contractions ◽  
Striated Muscles ◽  
Type Composition ◽  
The Common ◽  
Isometric Twitch

The parvalbumin content of mammalian muscles correlates positively with isometric relaxation rate and fiber type IIB frequency of the muscles but negatively with animal size. Since shrews are small-bodied animals with a relatively low number of type IIB fibers, it is of some interest to know how the parvalbumin content of shrew muscle correlates with the above factors. Parvalbumin content in heart, diaphragm, and gastrocnemius muscle of the common shrew, mouse, and rat was determined electrophoretically. Parvalbumin was not found in heart muscle of any species. Shrew diaphragm (0.29 ± 0.04 g/kg) had significantly less parvalbumin than mouse (0.63 ± 0.11 g/kg) or rat (0.54 ± 0.09 g/kg) diaphragm. Similarly, the parvalbumin content of shrew gastrocnemius muscle (0.28 ± 0.04 g/kg) was significantly lower than in that of mouse (2.88 ± 0.38 g/kg) or rat (0.96 ± 0.25 g/kg) gastrocnemius muscle. The isometric twitch of the gastrocnemius muscle was somewhat faster than the twitch of the diaphragm in all three species. The isometric contractions of shrew and mouse skeletal muscles were generally very similar in duration, with the exception of the relaxation time of the gastrocnemius muscle, which was shorter in the mouse. Diaphragm and gastrocnemius muscle of the rat were clearly slower than the respective muscles in the mouse or shrew with regard to both the contraction and relaxation phases. The half-relaxation time of isometric contractions correlated relatively weakly with parvalbumin content of the muscles (r = 0.40) but more strongly with their fiber IIB content (r = 0.81). The unexpectedly low parvalbumin content and relatively slow rate of contraction in shrew skeletal muscles are attributed to the exceptional fiber type composition, i.e., a high proportion of type IID fibers.

scholarly journals Ractopamine-induced fiber type-specific gene expression in porcine skeletal muscles is independent of growth

2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Andrea M Gunawan ◽  
Con-Ning Yen ◽  
Brian T Richert ◽  
Allan P Schinckel ◽  
Alan L Grant ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscles ◽  
Muscle Hypertrophy ◽  
Citrate Synthase ◽  
Fiber Type ◽  
Muscle Growth ◽  
Specific Gene ◽  
Type I ◽  
Fiber Types ◽  
Adequate Diet

Abstract Feeding ractopamine (RAC), a β-adrenergic agonist (BAA), to pigs increases type IIB muscle fiber type-specific protein and mRNA expression. However, increases in the abundance of these fast-twitch fiber types occur with other forms of muscle hypertrophy and thus BAA-induced changes in myosin heavy chain (MyHC) composition may simply be associated with increased muscle growth known to occur in response to BAA feeding. The objective of this study was to determine whether RAC feeding could change the MyHC gene expression in the absence of maximal muscle growth. Pigs were fed either an adequate diet that supported maximal muscle hypertrophy or a low nutrient diet that limited muscle growth. RAC was included in diets at 0 or 20 mg/kg for 1, 2, or 4 wk. Backfat depth was less (P &lt; 0.05) in pigs fed the low nutrient diet compared with the adequate diet but was not affected by RAC. Loin eye area was greater (P &lt; 0.05) in pigs fed an adequate diet plus RAC at 1 wk but did not differ among remaining pigs. At 2 and 4 wk, however, pigs fed the adequate diet had greater loin eye areas (P &lt; 0.05) than pigs fed the low nutrient diet regardless of RAC feeding. Gene expression of the MyHC isoforms, I, IIA, IIX, and IIB, as well as glycogen synthase, citrate synthase, β 1-adrenergic receptor (AR), and β 2-AR were determined in longissimus dorsi (LD) and red (RST) and white (WST) portions of the semitendinosus muscles. MyHC type I gene expression was not altered by RAC or diet. Feeding RAC decreased (P &lt; 0.01) MyHC type IIA gene expression in all muscles, but to a greater extent in WST and LD. MyHC type IIX gene expression was lower (P &lt; 0.05) in WST and LD muscles in response to RAC but was not altered in RST muscles. RAC increased (P &lt; 0.05) MyHC type IIB gene expression in all muscles, but to a greater extent in RST. β 1-AR gene expression was unaffected by RAC or diet, whereas the expression of the β 2-AR gene was decreased (P &lt; 0.001) by RAC. No significant RAC * diet interactions were observed in gene expression in this study, indicating that RAC altered MyHC and β 2-AR gene expression in porcine skeletal muscles independent of growth.

scholarly journals The long noncoding RNA MyHC IIA/X-AS contributes to skeletal muscle myogenesis and maintains the fast fiber phenotype

2020 ◽  
Vol 295 (15) ◽  
pp. 4937-4949 ◽  
Author(s):  
Mingle Dou ◽  
Ying Yao ◽  
Lu Ma ◽  
Xiaoyu Wang ◽  
Xin'e Shi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Fiber ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Skeletal Muscles ◽  
Fiber Type ◽  
Muscle Fiber Type ◽  
Fast Fiber ◽  
Slow Type ◽  
Myhc Expression

Mammalian skeletal muscles comprise different types of muscle fibers, and this muscle fiber heterogeneity is generally characterized by the expression of myosin heavy chain (MyHC) isoforms. A switch in MyHC expression leads to muscle fiber–type transition under various physiological and pathological conditions, but the underlying regulator coordinating the switch of MyHC expression remains largely unknown. Experiments reported in this study revealed the presence of a skeletal muscle–specific antisense transcript generated from the intergenic region between porcine MyHC IIa and IIx and is referred to here as MyHC IIA/X-AS. We found that MyHC IIA/X-AS is identified as a long noncoding RNA (lncRNA) that is strictly expressed in skeletal muscles and is predominantly distributed in the cytoplasm. Genetic analysis disclosed that MyHC IIA/X-AS stimulates cell cycle exit of skeletal satellite cells and their fusion into myotubes. Moreover, we observed that MyHC IIA/X-AS is more enriched in fast-twitch muscle and represses slow-type gene expression and thereby maintains the fast phenotype. Furthermore, we found that MyHC IIA/X-AS acts as a competing endogenous RNA that sponges microRNA-130b (miR-130b) and thereby maintains MyHC IIx expression and the fast fiber type. We also noted that miR-130b was proved to down-regulate MyHC IIx by directly targeting its 3′-UTR. Together, the results of our study uncovered a novel pathway, which revealed that lncRNA derived from the skeletal MyHC cluster could modulate local MyHC expression in trans, highlighting the role of lncRNAs in muscle fiber–type switching.

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