scholarly journals Proto-oncogene expression in proliferating and differentiating cardiac and skeletal muscle

1987 ◽  
Vol 247 (3) ◽  
pp. 701-706 ◽  
Author(s):  
W C Claycomb ◽  
N A Lanson
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Muscle Tissue ◽  
Cellular Proliferation ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Specific Cell ◽  
Adult Rats ◽  
Cardiac Muscle Cells ◽  
Oncogene Expression

We have examined the expression of 13 proto-oncogenes in proliferating and terminally differentiated cardiac and skeletal muscle. Total RNA was prepared from intact ventricular cardiac-muscle tissue and from purified ventricular cardiac-muscle cells of neonatal and adult rats and from cultured proliferating and terminally differentiated L6A1 rat skeletal-muscle cells. cDNA probes for histone H4, thymidine kinase, myosin heavy chain and M-creatine kinase were used to assess cellular proliferation and differentiation. Oncogenes c-myc, c-raf, c-erb-A, c-ras-H, c-ski, and c-sis were expressed in both proliferating and differentiated cardiac muscle tissue and cells, whereas c-myb expression was not observed in either. c-src was expressed only in neonatal cardiac muscle tissue and cells. c-fms, c-abl, and c-ras-K were expressed in tissue from both neonatal and adult animals but only in purified cells from neonatal animals. c-fes/fps was expressed only in neonatal cardiac muscles cells. c-fos expression was not observed in cardiac-muscle tissue from either neonatal or adult rats, but surprisingly was abundantly expressed in freshly isolated cardiac-muscle cells from animals of both ages. These results emphasize that biochemical analysis using intact cardiac-muscle tissue may not necessarily reflect muscle-specific cell processes. They also show that the expression of c-fos can be activated by the cell isolation procedure. c-myc, c-ski, c-ras-H, c-ras-K, c-abl, c-raf and c-erb-A were expressed in both proliferating and terminally differentiated skeletal-muscle cells, whereas c-myb, c-fos, c-src and c-fms transcripts were observed only in proliferating cells. c-fes/fps and c-sis were not expressed in dividing or fused skeletal-muscle cells. These results demonstrate unique tissue and cell-specific patterns of proto-oncogene expression and suggest that these genes may be involved with the regulation of cellular proliferation and terminal differentiation in striated muscle.

Effects of clofibric acid on amino acid metabolism in cultured rat skeletal muscle

1981 ◽  
Vol 240 (2) ◽  
pp. E203-E208
Author(s):  
W. M. Pardridge ◽  
L. Duducgian-Vartavarian ◽  
D. Casanello-Ertl ◽  
M. R. Jones ◽  
J. D. Kopple
Keyword(s):  
Skeletal Muscle ◽  
Amino Acid ◽  
Muscle Cells ◽  
Clofibric Acid ◽  
Skeletal Muscle Cells ◽  
Adult Rats ◽  
Carbohydrate Utilization ◽  
Branched Chain Amino Acid ◽  
Amino Acid Utilization ◽  
Branched Chain

Well-differentiated cultured skeletal muscle cells (myotubes) obtained from adult rats were incubated for up to 48 h in Dulbecco's modified Eagle's medium. Medium glucose decreased from 4.9 +/- 0.1 mM at 0 h to 13 +/- 1 microM by 24 h; approximately 60% of glucose was converted to lactate. Pyruvate, alanine, and citrate were continuously produced, even during the period of 24-48 h when no glucose or lactate utilization was observed. Branched-chain amino acid utilization increased more than fourfold during the incubation period of 24-48 h; during this time, intracellular ATP, pyruvate, alpha-ketoglutarate, malate, and citrate levels were constant despite the absence of glucose or lactate consumption. Incubation of muscle cells with 2 mM clofibric acid resulted in a 76% inhibition of leucine metabolism. Coincident with the drug-induced inhibition of a branched-chain amino acid utilization, alanine and citrate production was blocked, and cell levels of pyruvate, alpha-ketoglutarate, malate, and citrate were markedly reduced. These studies suggest branched-chain amino acids contribute significantly to anaplerotic pathways in cultured skeletal muscle cells and that these pathways lead to the net production of alanine and citrate during periods of minimal carbohydrate utilization.

scholarly journals Tissue-specific transcription of the cardiac myosin light-chain 2 gene is regulated by an upstream repressor element.

1991 ◽  
Vol 11 (3) ◽  
pp. 1676-1685 ◽  
Author(s):  
R A Shen ◽  
S K Goswami ◽  
E Mascareno ◽  
A Kumar ◽  
M A Siddiqui
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Tissue Specific ◽  
Myosin Light Chain 2 ◽  
Functional Components

Physiological expression of the cardiac muscle myosin light-chain 2 (MLC-2) gene in chickens is restricted to cardiac muscle tissue only, at least during the late embryonic to adult stages of development. The mechanism by which cardiac MLC-2 gene expression is repressed in differentiated noncardiac muscle tissues is unknown. Using sequential 5'-deletion mutants of the cardiac MLC-2 promoter introduced into primary skeletal muscle cells in culture, we have demonstrated that a 89-bp region, designated the cardiac-specific sequence (CSS), is essential for repression of cardiac MLC-2 expression in skeletal muscle. Removal of the CSS sequence alone allows transcription in skeletal muscle cells without affecting the transcriptional activity of the promoter in cardiac muscle cells. DNase I footprinting and gel shift assays indicate that protein binding to sequences in the CSS domain occurs readily in nuclear extracts obtained from skeletal muscle but not in extracts isolated under identical conditions from cardiac muscle. Thus, it appears that a negative regulatory mechanism accounts for the lack of expression of the cardiac MLC-2 gene in skeletal muscle and that the CSS element and its binding proteins are important functional components of the regulatory apparatus which ensures the developmental program for cardiac tissue-specific gene expression.

scholarly journals Preproenkephalin mRNA expression in developing rat heart and in cultured ventricular cardiac muscle cells

1989 ◽  
Vol 258 (1) ◽  
pp. 73-78 ◽  
Author(s):  
J P Springhorn ◽  
W C Claycomb
Keyword(s):  
Cardiac Muscle ◽  
Cell Cultures ◽  
Translational Regulation ◽  
Muscle Cells ◽  
Heart Cell ◽  
Developmentally Regulated ◽  
Adult Rats ◽  
Cardiac Muscle Cells ◽  
Adult Rat ◽  
Developing Rat

Heart muscle tissue has previously been reported to have the highest content of preproenkephalin (ppEnk) mRNA of any tissue in the adult rat. We have determined that it is present in the ventricular cardiac muscle cells of the heart and is developmentally regulated. The expression of ppEnk mRNA was observed to be low throughout the first 2 weeks of postnatal development and decreases substantially during week 3. Expression was again low by week 4, but by adulthood (approx. 3 months), it reached a maximum. ppEnk mRNA was actively expressed in primary cardiac muscle cell cultures prepared from both neonatal and adult rats. Its steady-state content in cell cultures was observed to be increased by cyclic AMP and 3-isobutyl-1-methylxanthine. The phorbol ester phorbol 12-myristate 13-acetate elicited a transient effect (i.e. an increase was observed at 4 h and a return to control values by 24 h). We speculate that enkephalin may play a multi-functional role in the differentiation of neonatal cardiac muscle cells and in the terminally differentiated adult heart cell. We demonstrate that the primary culture systems employed in this study will be useful models with which to explore both transcriptional and translational regulation of ppEnk mRNA in the heart.

The effect of rocuronium, sugammadex, and their combination on cardiac muscle and diaphragmatic skeletal muscle cells

2012 ◽  
Vol 26 (6) ◽  
pp. 870-877 ◽  
Author(s):  
Yildiray Kalkan ◽  
Habib Bostan ◽  
Levent Tumkaya ◽  
Yakup Tomak ◽  
Mehmet Bostan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Muscle Cells ◽  
Skeletal Muscle Cells

scholarly journals Controllable assembly of skeletal muscle-like bundles through 3D bioprinting

2021 ◽  
Author(s):  
Tingting Fan ◽  
Shuo Wang ◽  
Zongmin Jiang ◽  
Shen Ji ◽  
Wenhua Cao ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
3D Printing ◽  
Muscle Tissue ◽  
Muscle Cells ◽  
Skeletal Muscle Tissue ◽  
Skeletal Muscle Cells ◽  
Muscle Fibres ◽  
Physical Factors

Abstract 3D printing is an effective technology for recreating skeletal muscle tissue in vitro. To achieve clinical skeletal muscle injury repair, relatively large volumes of highly aligned skeletal muscle cells are required; obtaining these is still a challenge. It is currently unclear how individual skeletal muscle cells and their neighbouring components co-ordinate to establish anisotropic architectures in highly homogeneous orientations. Here, we demonstrated a 3D printing strategy followed by sequential culture processes to engineer skeletal muscle tissue. The effects of confined printing on the skeletal muscle during maturation, which impacted the myotube alignment, myogenic gene expression, and mechanical forces, were observed. Our findings demonstrate the dynamic changes of skeletal muscle tissue during in vitro 3D construction and reveal the role of physical factors in the orientation and maturity of muscle fibres.

Arginine metabolism and urea synthesis in cultured rat skeletal muscle cells

1982 ◽  
Vol 242 (2) ◽  
pp. E87-E92 ◽  
Author(s):  
W. M. Pardridge ◽  
L. Duducgian-Vartavarian ◽  
D. Casanello-Ertl ◽  
M. R. Jones ◽  
J. D. Kopple
Keyword(s):  
Skeletal Muscle ◽  
Calf Serum ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Urea Synthesis ◽  
Adult Rats ◽  
Peripheral Tissues ◽  
Hindlimb Muscle ◽  
Amino Acid Concentrations ◽  
Exact Origin

Skeletal muscle is known to contain arginase, but, because this enzyme is also present in erythrocytes, the exact origin of arginine-derived ornithine in peripheral tissues is uncertain. In the present studies, skeletal muscle cells obtained from regenerating hindlimb muscle of adult rats were grown in primary tissue culture for approximately 3 wk and then studied in regard to changes in medium amino acid concentrations over a 48-h period. The consumption of arginine and serine was observed in parallel with the production of ornithine, proline, citrulline, glycine, and urea. Medium threonine and methionine concentrations were relatively constant over 48 h. Incubation of muscle cells with [U-14C]arginine resulted in the formation of [14C]ornithine and [14C]proline at rates at least 10-fold greater than could be accounted for by enzyme constituents of fetal calf serum. In addition, [guanido-14C]arginine was converted to [14C]urea and [U-14C]serine was converted to [14C]glycine. These studies indicate that cultured skeletal muscle cells contain a high arginase capacity and actively synthesize ornithine and urea from arginine.

scholarly journals The potassium channels TASK2 and TREK1 regulate functional differentiation of murine skeletal muscle cells

2016 ◽  
Vol 311 (4) ◽  
pp. C583-C595 ◽  
Author(s):  
Ali M. Afzali ◽  
Tobias Ruck ◽  
Alexander M. Herrmann ◽  
Janette Iking ◽  
Claudia Sommer ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Tissue ◽  
Outward Current ◽  
Muscle Cells ◽  
Human Muscle ◽  
C2c12 Cells ◽  
Skeletal Muscle Cells ◽  
Mouse Muscle ◽  
Organ Systems ◽  
Primary Mouse

Two-pore domain potassium (K2P) channels influence basic cellular parameters such as resting membrane potential, cellular excitability, or intracellular Ca2+-concentration [Ca2+]i. While the physiological importance of K2P channels in different organ systems (e.g., heart, central nervous system, or immune system) has become increasingly clear over the last decade, their expression profile and functional role in skeletal muscle cells (SkMC) remain largely unknown. The mouse SkMC cell line C2C12, wild-type mouse muscle tissue, and primary mouse muscle cells (PMMs) were analyzed using quantitative PCR, Western blotting, and immunohistochemical stainings as well as functional analysis including patch-clamp measurements and Ca2+ imaging. Mouse SkMC express TWIK-related acid-sensitive K+ channel (TASK) 2, TWIK-related K+ channel (TREK) 1, TREK2, and TWIK-related arachidonic acid stimulated K+ channel (TRAAK). Except TASK2 all mentioned channels were upregulated in vitro during differentiation from myoblasts to myotubes. TASK2 and TREK1 were also functionally expressed and upregulated in PMMs isolated from mouse muscle tissue. Inhibition of TASK2 and TREK1 during differentiation revealed a morphological impairment of myoblast fusion accompanied by a downregulation of maturation markers. TASK2 and TREK1 blockade led to a decreased K+ outward current and a decrease of ACh-dependent Ca2+ influx in C2C12 cells as potential underlying mechanisms. K2P-channel expression was also detected in human muscle tissue by immunohistochemistry pointing towards possible relevance for human muscle cell maturation and function. In conclusion, our findings for the first time demonstrate the functional expression of TASK2 and TREK1 in muscle cells with implications for differentiation processes warranting further investigations in physiologic and pathophysiologic scenarios.

scholarly journals Cellular trafficking determines the exon skipping activity of Pip6a-PMO in mdx skeletal and cardiac muscle cells

2013 ◽  
Vol 42 (5) ◽  
pp. 3207-3217 ◽  
Author(s):  
Taavi Lehto ◽  
Alejandra Castillo Alvarez ◽  
Sarah Gauck ◽  
Michael J. Gait ◽  
Thibault Coursindel ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Biological Activity ◽  
Exon Skipping ◽  
Muscle Cells ◽  
Mechanistic Explanation ◽  
Endosomal Escape ◽  
Skeletal Muscle Cells ◽  
Great Promise ◽  
Cellular Trafficking ◽  
Cardiac Muscle Cells

Abstract Cell-penetrating peptide-mediated delivery of phosphorodiamidate morpholino oligomers (PMOs) has shown great promise for exon-skipping therapy of Duchenne Muscular Dystrophy (DMD). Pip6a-PMO, a recently developed conjugate, is particularly efficient in a murine DMD model, although mechanisms responsible for its increased biological activity have not been studied. Here, we evaluate the cellular trafficking and the biological activity of Pip6a-PMO in skeletal muscle cells and primary cardiomyocytes. Our results indicate that Pip6a-PMO is taken up in the skeletal muscle cells by an energy- and caveolae-mediated endocytosis. Interestingly, its cellular distribution is different in undifferentiated and differentiated skeletal muscle cells (vesicular versus nuclear). Likewise, Pip6a-PMO mainly accumulates in cytoplasmic vesicles in primary cardiomyocytes, in which clathrin-mediated endocytosis seems to be the pre-dominant uptake pathway. These differences in cellular trafficking correspond well with the exon-skipping data, with higher activity in myotubes than in myoblasts or cardiomyocytes. These differences in cellular trafficking thus provide a possible mechanistic explanation for the variations in exon-skipping activity and restoration of dystrophin protein in heart muscle compared with skeletal muscle tissues in DMD models. Overall, Pip6a-PMO appears as the most efficient conjugate to date (low nanomolar EC50), even if limitations remain from endosomal escape.

Tissue-specific transcription of the cardiac myosin light-chain 2 gene is regulated by an upstream repressor element

1991 ◽  
Vol 11 (3) ◽  
pp. 1676-1685
Author(s):  
R A Shen ◽  
S K Goswami ◽  
E Mascareno ◽  
A Kumar ◽  
M A Siddiqui
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Light Chain ◽  
Myosin Light Chain ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Tissue Specific ◽  
Myosin Light Chain 2 ◽  
Functional Components

Physiological expression of the cardiac muscle myosin light-chain 2 (MLC-2) gene in chickens is restricted to cardiac muscle tissue only, at least during the late embryonic to adult stages of development. The mechanism by which cardiac MLC-2 gene expression is repressed in differentiated noncardiac muscle tissues is unknown. Using sequential 5'-deletion mutants of the cardiac MLC-2 promoter introduced into primary skeletal muscle cells in culture, we have demonstrated that a 89-bp region, designated the cardiac-specific sequence (CSS), is essential for repression of cardiac MLC-2 expression in skeletal muscle. Removal of the CSS sequence alone allows transcription in skeletal muscle cells without affecting the transcriptional activity of the promoter in cardiac muscle cells. DNase I footprinting and gel shift assays indicate that protein binding to sequences in the CSS domain occurs readily in nuclear extracts obtained from skeletal muscle but not in extracts isolated under identical conditions from cardiac muscle. Thus, it appears that a negative regulatory mechanism accounts for the lack of expression of the cardiac MLC-2 gene in skeletal muscle and that the CSS element and its binding proteins are important functional components of the regulatory apparatus which ensures the developmental program for cardiac tissue-specific gene expression.

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