Dexamethasone effects on creatine kinase activity and insulin‐like growth factor receptors in cultured muscle cells

Whitson, Peggy A.; Stuart, Charles Alexander; Huls, M. Helen; Sams, Clarence F.; Cintron, Nitza M.

doi:10.1002/jcp.1041400103

Cited by 25 publications

(18 citation statements)

References 62 publications

(34 reference statements)

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“…The LDH and citrate synthase activity increase at differentiation in the latter cell line. CK activity measured on serumderived C2C1~ myotubes was higher than found in a previous study (Whitson et al, 1989). They reported a twofold higher CK activity when C2C12 cells were cultured for 8 d on 2% horse serum with at least 3 ~rM dexamethasone.…”

Section: Resultscontrasting

confidence: 59%

“…A large proportion of the myoblasts did not fuse. These cells may reflect the quiescent satellite-like reserve cells as described for CzC12 mouse myoblast cells (Yoshida et al, 1998). When subcloned, these reserve cells retain their capacity to generate cells that fuse into myotubes.…”

Section: Resultsmentioning

confidence: 97%

“…Experiments on cultured muscle cell lines are also applied in the study of differentiation-dependent protein expression (Inestrosa et al, 1983;Evans et al, 1987;Whitson et al, 1989;Thinakaran et al, 1993;Passaquin et al, 1994) and sugar transport (Klip and Marette, 1992). Commonly used myogenic cell lines are mouse C2C12 and rat L~,, cells which grow in media supplemented with fetal calf serum.…”

Section: Introductionmentioning

confidence: 98%

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Differentiation markers of mouse C2C12 and rat L6 myogenic cell lines and the effect of the differentiation medium

Portier

Benders

Oosterhof

et al. 1999

In Vitro Cell.Dev.Biol.-Animal

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The differentiation grade of cells in culture is dependent on the composition of the culture medium. Two commonly used myogenic cell lines, mouse C2C12 and rat L6, usually differentiate at a low concentration of horse serum. In this study we compared the effect of horse serum with a medium containing a low percentage of Ultroser G and rat brain extract. The maturation grade was evaluated on the basis of various biochemical, (immuno)histochemical and cell-physiological parameters. Substitution of horse serum by Ultroser G and rat brain extract during the differentiation phase resulted in a higher maturation grade of the myotubes of both cell lines, on the basis of creatine kinase activity and the diameter of the myotubes. In addition, the C2C12 myotubes display cross-striation, contain a higher percentage of creatine kinase muscle-specific isoenzyme MM, show a ninefold increase in acetylcholine receptor (AChR) clusters, form a continuous basement membrane, and have a lower resting cytosolic Ca2+ concentration. L6 myotubes show a fivefold increase in AChR clusters and a twofold increase in the expression of the mRNA of the epsilon-subunit of AChR.C2C12 cells show spontaneous contraction and response of cytosolic Ca2+ to various stimulants in contrast to L6 cells which do not. These studies established that the Ultroser G/brain extract medium leads to a higher differentiation grade of both cell lines, but parameters appropriate for use as differentiation markers appear to differ between both cell lines.

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Section: Resultscontrasting

confidence: 59%

Section: Resultsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 98%

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Differentiation markers of mouse C2C12 and rat L6 myogenic cell lines and the effect of the differentiation medium

Portier

Benders

Oosterhof

et al. 1999

In Vitro Cell.Dev.Biol.-Animal

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“…For AIB uptake, this was associated with an increase in type I IGF receptor number. In addition, dexamethasone has recently been shown to potentiate the effect of IGF-I on creatine ki- nase activity in myogenic cells (Whitson et al, 1989). In contrast, we found no effect of dexamethasone on either basal or IGF-I stimulated AIB uptake in chicken myotubes (Fig.…”

Section: Discussioncontrasting

confidence: 61%

Regulation of amino acid transport and protein metabolism in myotubes derived from chicken muscle satellite cells by insulin‐like growth factor‐I

Duclos¹,

Chevalier²,

Goddard

et al. 1993

Journal Cellular Physiology

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The effects of insulin and insulin-like growth factor-I (IGF-I) on amino acid transport and protein metabolism were compared in myotubes derived from chicken breast muscle satellite cells. Protein synthesis was assessed by continuous labelling with [3H]-tyrosine. Protein degradation was estimated by the release of trichloroacetic acid (TCA) soluble radioactivity by cells which had been previously labelled with [3H]-tyrosine for 3 days. Amino acid transport was measured in myotubes incubated in Dulbecco's modified Eagle's medium (DMEM) 0.5% bovine serum albumin (BSA) with or without insulin or IGF-I. Subsequent [3H]-aminoisobutyric acid (AIB) uptake was then measured in amino acid-free medium. IGF-I was more efficient than insulin at equimolar concentration (3.2 nmol/l) in stimulating protein synthesis (127 and 113% of basal, respectively) and inhibiting protein degradation (32% and 13% inhibition of protein degradation following 4 h incubation). Half maximal effective concentrations for stimulation of AIB uptake were 0.27 +/- 0.03 nmol/l and 34.8 +/- 3.1 nmol/l for IGF-I and insulin respectively, with maximal stimulation of about 340% of basal. Cycloheximide (3.6 mumol/l) diminished IGF-I-stimulated AIB uptake by 55%. Chicken growth hormone had no effect on basal AIB uptake in these cells and neither glucagon nor dexamethasone had an effect on basal or IGF-I-stimulated AIB uptake. This study demonstrates an anabolic effect for IGF-I in myotubes derived from primary chicken satellite cells which is mediated by the type I IGF receptor, since the cation-independent mannose 6-phosphate receptor does not bind IGF-II in chicken cells.

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“…Dexamethasone induces glutamine synthetase in L6 myoblasts, with a significant decrease of total protein synthesis (Max et al, 1987). Moreover, its interference with growth factor circuits has been documented in different normal myogenic models (Whitson et al, 1989;Southorn & Palmer, 1990;Poon et al, 1991).…”

Section: Resultsmentioning

confidence: 99%

Uncoupling of growth inhibition and differentiation in dexamethasone-treated human rhabdomyosarcoma cells

Giovanni

Lollini²,

Dolcetti³

et al. 1993

Br J Cancer

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Summary The effects of dexamethasone, a synthetic glucocorticoid, and of N,N-dimethylformamide on in vitro growth and differentiation and on proto-oncogene expression of human rhabdomyosarcoma cells were studied. RD/18 clone cells (derived from the embryonal rhabdomyosarcoma cell line RD) treated with 100 nM dexamethasone showed an almost complete block of differentiation: about 5% myosin-positive cells were observed after 2 weeks of culture in dexamethasone-supplemented differentiation medium, compared to 20% of untreated cultures. Dexamethasone also induced a 20-30% growth inhibition and a more flattened morphology. The treatment with N,N-dimethylformamide induced a significantly increased proportion of myosin-positive cells (reaching about 30%) and a 40% growth inhibition.Induction of differentiation inversely correlated with the levels of c-myc proto-oncogene expression: after a 2 week culture dexamethasone-treated cells showed the highest c-myc expression and N,N-dimethylformamidetreated cells the lowest. Culture conditions per se down-modulated c-erbBI and up-regulated c-jun expression, with no relationship to the differentiation pattern. Other proto-oncogenes were not expressed (c-sis, N-myc, c-mos, c-myb) or were not modulated (c-fos, c-raj).Therefore dexamethasone and N,N-dimethylformamide, both causing a decreased growth rate, showed opposing actions on myogenic differentiation and on c-myc proto-oncogene expression of human rhabdomyosarcoma cells.

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Dexamethasone effects on creatine kinase activity and insulin‐like growth factor receptors in cultured muscle cells

Cited by 25 publications

References 62 publications

Differentiation markers of mouse C2C12 and rat L6 myogenic cell lines and the effect of the differentiation medium

Differentiation markers of mouse C2C12 and rat L6 myogenic cell lines and the effect of the differentiation medium

Regulation of amino acid transport and protein metabolism in myotubes derived from chicken muscle satellite cells by insulin‐like growth factor‐I

Uncoupling of growth inhibition and differentiation in dexamethasone-treated human rhabdomyosarcoma cells

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