Developmental regulation of calmodulin gene expression in rat brain and skeletal muscle.

Three different calmodulin genes that encode the identical protein have been identified in the rat (Nojima, 1989); however, calmodulin gene expression at the various stages of tissue differentiation and maturation has not been previously determined. We have quantitated the content of mRNAs encoding calmodulin in the developing brain and skeletal muscle using RNA blot analysis with three specific cDNA probes. Our results show that five species of calmodulin mRNAs: 4.0 and 1.7 kb for CaM I, 1.4 kb for CaM II, and 2.3 and 0.8 kb for CaM III are detectable at all ages in the brain as well as in skeletal muscle but exhibit a tissue-specific developmental pattern of expression. The comparison of the temporal pattern of calmodulin gene expression with both mitotic activity, as demonstrated by cyclin A mRNA levels, and differentiation and maturation of specific brain or muscle regions is consistent with calmodulin involvement in development.

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Gene expression analysis of the pro-oestrous-stage rat uterus reveals neuroligin 2 as a novel steroid-regulated gene

Reproduction Fertility and Development ◽

10.1071/rd04040 ◽

2004 ◽

Vol 16 (8) ◽

pp. 763 ◽

Cited By ~ 8

Author(s):

Han-Seung Kang ◽

Chae-Kwan Lee ◽

Ju-Ran Kim ◽

Seong-Jin Yu ◽

Sung-Goo Kang ◽

...

Keyword(s):

Gene Expression ◽

Northern Blot ◽

Blot Analysis ◽

Northern Blot Analysis ◽

Expression Profiles ◽

Expression Patterns ◽

Oestrous Cycle ◽

Mrna Levels ◽

Rat Uterus ◽

Ovx Rats

In the present study, differential gene expression in the uteri of ovariectomised (OVX) and pro-oestrous rats (OVX v. pro-oestrus pair) was investigated using cDNA expression array analysis. Differential uterine gene expression in OVX rats and progesterone (P4)-injected OVX rats (OVX v. OVX + P4 pair) was also examined. The uterine gene expression profiles of these two sets of animals were also compared for the effects of P4 treatment. RNA samples were extracted from uterine tissues and reverse transcribed in the presence of [α32P]-dATP. Membrane sets of rat arrays were hybridised with cDNA probe sets. Northern blot analysis was used to validate the relative gene expression patterns obtained from the cDNA array. Of the 1176 cDNAs examined, 23 genes showed significant (>two-fold) changes in expression in the OVX v. pro-oestrus pair. Twenty of these genes were upregulated during pro-oestrus compared with their expression in the OVX rat uterus. In the OVX v. OVX + P4 pair, 22 genes showed significant (>two-fold) changes in gene expression. Twenty of these genes were upregulated in the OVX + P4 animals. The genes for nuclear factor I–XI, afadin, neuroligin 2, semaphorin Z, calpain 4, cyclase-associated protein homologue, thymosin β-4X and p8 were significantly upregulated in the uteri of the pro-oestrus and OVX + P4 rats of both experimental pairs compared with the OVX rat uteri. These genes appear to be under the control of P4. One of the most interesting findings of the present study is the unexpected and marked expression of the neuroligin 2 gene in the rat uterus. This gene is expressed at high levels in the central nervous system and acts as a nerve cell adhesion factor. According to Northern blot analysis, neuroligin 2 gene expression was higher during the pro-oestrus and metoestrus stages than during the oestrus and dioestrus stages of the oestrous cycle. In addition, neuroligin 2 mRNA levels were increased by both 17β-oestradiol (E2) and P4, although P4 administration upregulated gene expression to a greater extent than injection of E2. These results indicate that neuroligin 2 gene expression in the rat uterus is under the control of both E2 and P4, which are secreted periodically during the oestrous cycle.

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

Journal of Cell Science ◽

10.1242/jcs.114.2.303 ◽

2001 ◽

Vol 114 (2) ◽

pp. 303-310 ◽

Cited By ~ 2

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.

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Changes in Gene Expression of the MCU Complex Are Induced by Electrical Stimulation in Adult Skeletal Muscle

Frontiers in Physiology ◽

10.3389/fphys.2020.601313 ◽

2021 ◽

Vol 11 ◽

Author(s):

Esteban R. Quezada ◽

Alexis Díaz-Vegas ◽

Enrique Jaimovich ◽

Mariana Casas

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Electrical Stimulation ◽

Muscle Fibers ◽

Low Frequency ◽

Extracellular Atp ◽

Mrna Levels ◽

Dependent Manner ◽

Adult Skeletal Muscle ◽

Muscle Plasticity

The slow calcium transient triggered by low-frequency electrical stimulation (ES) in adult muscle fibers and regulated by the extracellular ATP/IP3/IP3R pathway has been related to muscle plasticity. A regulation of muscular tropism associated with the MCU has also been described. However, the role of transient cytosolic calcium signals and signaling pathways related to muscle plasticity over the regulation of gene expression of the MCU complex (MCU, MICU1, MICU2, and EMRE) in adult skeletal muscle is completely unknown. In the present work, we show that 270 0.3-ms-long pulses at 20-Hz ES (and not at 90 Hz) transiently decreased the mRNA levels of the MCU complex in mice flexor digitorum brevis isolated muscle fibers. Importantly, when ATP released after 20-Hz ES is hydrolyzed by the enzyme apyrase, the repressor effect of 20 Hz on mRNA levels of the MCU complex is lost. Accordingly, the exposure of muscle fibers to 30 μM exogenous ATP produces the same effect as 20-Hz ES. Moreover, the use of apyrase in resting conditions (without ES) increased mRNA levels of MCU, pointing out the importance of extracellular ATP concentration over MCU mRNA levels. The use of xestospongin B (inhibitor of IP3 receptors) also prevented the decrease of mRNA levels of MCU, MICU1, MICU2, and EMRE mediated by a low-frequency ES. Our results show that the MCU complex can be regulated by electrical stimuli in a frequency-dependent manner. The changes observed in mRNA levels may be related to changes in the mitochondria, associated with the phenotypic transition from a fast- to a slow-type muscle, according to the described effect of this stimulation frequency on muscle phenotype. The decrease in mRNA levels of the MCU complex by exogenous ATP and the increase in MCU levels when basal ATP is reduced with the enzyme apyrase indicate that extracellular ATP may be a regulator of the MCU complex. Moreover, our results suggest that this regulation is part of the axes linking low-frequency stimulation with ATP/IP3/IP3R.

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The influence of direct and indirect fibroblast cell contact on human myogenic cell behavior and gene expression in vitro

Journal of Applied Physiology ◽

10.1152/japplphysiol.00215.2019 ◽

2019 ◽

Vol 127 (2) ◽

pp. 342-355 ◽

Cited By ~ 1

Author(s):

Cecilie J. L. Bechshøft ◽

Peter Schjerling ◽

Michael Kjaer ◽

Abigail L. Mackey

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Cell Proliferation ◽

Myogenic Cell ◽

Mrna Levels ◽

Indirect Contact ◽

Permeable Membrane ◽

Primary Myoblasts ◽

Cell Proliferation And Differentiation ◽

Proliferation And Differentiation

Underpinning skeletal muscle plasticity is the interplay between many cell types, of which fibroblasts are emerging as potent players, both negatively in the development of fibrosis but also positively in stimulating muscle repair through enhancing myogenesis. The mechanisms behind this interaction however remain unknown. To investigate this, waste hamstring muscle tissue was obtained from eight healthy young men undergoing reconstructive anterior cruciate ligament surgery and primary myoblasts and fibroblasts were isolated. Myoblasts were cultured alone or with fibroblasts, either in direct or indirect contact (separated by an insert with a permeable membrane). The myogenesis parameters proliferation, differentiation, and fusion were determined from immunostained cells, while, in replicate samples, gene expression levels of GAPDH, Ki67, Pax7, MyoD, myogenin, myomaker, MHC-Iβ, TCF7L2, COL1A1, and p16 were determined by RT-PCR. We found only trends for an influence of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. While greater mRNA levels of GAPDH, Pax7, MyoD, myogenin, and MHC-Iβ were observed in myogenic cells in indirect contact with fibroblasts (insert) when compared with cells cultured alone, a similar effect of an empty insert was also observed. In conclusion we find very little influence of skeletal muscle fibroblasts on myoblasts derived from the same tissue, although it cannot be excluded that a different outcome would be seen under less optimal myogenic growth conditions. NEW & NOTEWORTHY Using passage one primary myoblasts and fibroblasts isolated from human skeletal muscle, we found only a trend for an effect of skeletal muscle fibroblasts on myogenic cell proliferation and differentiation. This is contrary to previous reports and raises the possibility that fibroblasts of different tissue origins exert distinct roles.

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Sex Differences in the Metabolic Effects of Testosterone in Sheep

Endocrinology ◽

10.1210/en.2011-1634 ◽

2012 ◽

Vol 153 (1) ◽

pp. 123-131 ◽

Cited By ~ 19

Author(s):

Scott D. Clarke ◽

Iain J. Clarke ◽

Alexandra Rao ◽

Michael A. Cowley ◽

Belinda A. Henry

Keyword(s):

Skeletal Muscle ◽

Protein Kinase ◽

Uncoupling Protein ◽

Specific Effect ◽

Metabolic Effects ◽

Mrna Levels ◽

Nonesterified Fatty Acids ◽

Glucose Levels ◽

Amp Activated Protein Kinase ◽

The Brain

Adiposity is regulated in a sexually divergent manner. This is partly due to sex steroids, but the differential effects of androgens in males and females are unclear. We investigated effects of testosterone on energy balance in castrated male (n = 6) and female sheep (n = 4), which received 3 × 200 mg testosterone implants for 2 wk or blank implants (controls). Temperature probes were implanted into retroperitoneal fat and skeletal muscle. Blood samples were taken to measure metabolites and insulin. In males, muscle and fat biopsies were collected to measure uncoupling protein (UCP) mRNA and phosphorylation of AMP-activated protein kinase and Akt. Testosterone did not change food intake in either sex. Temperature in muscle was higher in males than females, and testosterone reduced heat production in males only. In fat, however, temperature was higher in the castrate males compared with females, and there was no effect of testosterone treatment in either sex. Preprandial glucose levels were lower, but nonesterified fatty acids were higher in females compared with males, irrespective of testosterone. In males, the onset of feeding increased UCP1 and UCP3 mRNA levels in skeletal muscle, without an effect of testosterone. During feeding, testosterone reduced glucose levels in males only but did not alter the phosphorylation of AMP-activated protein kinase or Akt in muscle. Thus, testosterone maintains lower muscle and fat temperatures in males but not females. The mechanism underlying this sex-specific effect of testosterone is unknown but may be due to sexual differentiation of the brain centers controlling energy expenditure.

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Activation of insulin-like growth factor gene expression during work-induced skeletal muscle growth

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1990.259.1.e89 ◽

1990 ◽

Vol 259 (1) ◽

pp. E89-E95 ◽

Cited By ~ 53

Author(s):

D. L. DeVol ◽

P. Rotwein ◽

J. L. Sadow ◽

J. Novakofski ◽

P. J. Bechtel

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Growth Factor ◽

Muscle Growth ◽

Experimental Period ◽

Mrna Levels ◽

Insulin Like Growth Factor ◽

Muscle Weight ◽

Skeletal Muscle Growth ◽

Igf I

We have investigated the hypothesis that there is local regulation of insulin-like growth factor (IGF) gene expression during skeletal muscle growth. Compensatory hypertrophy was induced in the soleus, a predominantly slow-twitch muscle, and plantaris, a fast-twitch muscle, in 11- to 12-wk-old female Wistar rats by unilateral cutting of the distal gastrocnemius tendon. Animals were killed 2, 4, or 8 days later, and muscles of the nonoperated leg served as controls. Muscle weight increased throughout the experimental period, reaching 127% (soleus) or 122% (plantaris) of control values by day 8. In both growing muscles, IGF-I mRNA, quantitated by a solution-hybridization nuclease-protection assay, rose by nearly threefold on day 2 and remained elevated throughout the experimental period. IGF-II mRNA levels also increased over controls. A more dramatic response was seen in hypophysectomized rats, where IGF-I mRNA levels rose by 8- to 13-fold, IGF-II values by 3- to 7-fold, and muscle mass increased on day 8 to 149% (soleus) or 133% (plantaris) of the control contralateral limb. These results indicate that signals propagated during muscle hypertrophy enhance the expression of both IGF genes, that modulation of IGF-I mRNA levels can occur in the absence of growth hormone, and that locally produced IGF-I and IGF-II may play a role in skeletal muscle growth.

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Multidirectional Changes in Parameters Related to Sulfur Metabolism in Frog Tissues Exposed to Heavy Metal-Related Stress

Biomolecules ◽

10.3390/biom10040574 ◽

2020 ◽

Vol 10 (4) ◽

pp. 574

Author(s):

Marta Kaczor-Kamińska ◽

Piotr Sura ◽

Maria Wróbel

Keyword(s):

Gene Expression ◽

Skeletal Muscle ◽

Heavy Metal ◽

Cadmium Toxicity ◽

Reactive Oxygen Species Generation ◽

Transcriptional Responses ◽

Sulfane Sulfur ◽

Related Stress ◽

The Brain

The investigations showed changes of the cystathionine γ-lyase (CTH), 3-mercaptopyruvate sulfurtransferase (MPST) and rhodanese (TST) activity and gene expression in the brain, heart, liver, kidney, skeletal muscles and testes in frogs Pelophylax ridibundus, Xenopus laevis and Xenopus tropicalis in response to Pb2+, Hg2+ and Cd2+ stress. The results were analyzed jointly with changes in the expression of selected antioxidant enzymes (cytoplasmic and mitochondrial superoxide dismutase, glutathione peroxidase, catalase and thioredoxin reducatase) and with the level of malondialdehyde (a product of lipid peroxidation). The obtained results allowed for confirming the role of sulfurtransferases in the antioxidant protection of tissues exposed to heavy metal ions. Our results revealed different transcriptional responses of the investigated tissues to each of the examined heavy metals. The CTH, MPST and TST genes might be regarded as heavy metal stress-responsive. The CTH gene expression up-regulation was confirmed in the liver (Pb2+, Hg2+, Cd2+) and skeletal muscle (Hg2+), MPST in the brain (Pb2+, Hg2+), kidney (Pb2+, Cd2+), skeletal muscle (Pb2+, Hg2+,Cd2+) and TST in the brain (Pb2+) and kidney (Pb2+, Hg2+, Cd2+). Lead, mercury and cadmium toxicity was demonstrated to affect the glutathione (GSH) and cysteine levels, the concentration ratio of reduced to oxidized glutathione ([GSH]/[GSSG]) and the level of sulfane sulfur-containing compounds, which in case of enhanced reactive oxygen species generation can reveal their antioxidative properties. The present report is the first to widely describe the role of the sulfane sulfur/H2S generating enzymes and the cysteine/glutathione system in Pb2+, Hg2+ and Cd2+ stress in various frog tissues, and to explore the mechanisms mediating heavy metal-related stress.

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