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.

Regulation of 4F2 heavy-chain gene expression during normal human T-cell activation can be mediated by multiple distinct molecular mechanisms

1988 ◽  
Vol 8 (9) ◽  
pp. 3820-3826
Author(s):  
T Lindsten ◽  
C H June ◽  
C B Thompson ◽  
J M Leiden
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Steady State ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Transcription Elongation ◽  
Fold Increase ◽  
Mrna Levels ◽  
Myristate Acetate

The 4F2 molecule belongs to the set of cell surface antigens which is induced following lectin- or antigen-mediated T-cell activation. The increase in 4F2 cell surface expression following lectin-mediated stimulation has been shown to be accompanied by a parallel increase in the steady-state levels of 4F2 heavy-chain (4F2HC) mRNA. The studies described in this report were designed to further elucidate the molecular mechanisms responsible for induction of 4F2HC gene expression following activation of normal resting human peripheral blood T cells. The low levels of mature 4F2HC mRNA in resting T cells were shown to be the result of a block to transcription elongation within the exon 1-intron 1 region of the 4F2HC gene rather than promoter inactivity. Phorbol myristate acetate stimulation of resting T cells resulted in a 20-fold increase in steady-state 4F2HC mRNA levels which was mediated by removal of this block to transcription elongation. The phorbol myristate acetate-induced increase in 4F2HC gene expression is distinct from previously described AP-1-mediated, phorbol ester-induced gene expression in that it requires new protein synthesis. Treatment of resting T cells with ionomycin plus PMA resulted in a 60-fold increase in 4F2HC mRNA levels. This induction was mediated by both an increase in promoter utilization and removal of the block to transcription elongation. Finally, by increasing the half-life of 4F2HC mRNA, cycloheximide treatment of resting T cells induced an approximately five fold increase in the levels of 4F2HC gene expression, although the physiologic significance of this mechanism remains unclear. These results demonstrate that the level of 4F2HC gene expression in normal peripheral blood T cells can be regulated by at least three distinct molecular pathways: (i) changes in promoter utilization, (ii) modulation of a block to transcription elongation, and (iii) alteration in mRNA stability.

Effects of streptozotocin-induced diabetes and physical training on gene expression of titin-based stretch-sensing complexes in mouse striated muscle

2007 ◽  
Vol 292 (2) ◽  
pp. E533-E542 ◽  
Author(s):  
T. Maarit Lehti ◽  
Mika Silvennoinen ◽  
Riikka Kivelä ◽  
Heikki Kainulainen ◽  
Jyrki Komulainen
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Cardiac Muscle ◽  
Physical Training ◽  
Striated Muscle ◽  
Fiber Type ◽  
Training Session ◽  
Mrna Levels ◽  
Strain Sensing ◽  
Induced Changes

In striated muscle, a sarcomeric noncontractile protein, titin, is proposed to form the backbone of the stress- and strain-sensing structures. We investigated the effects of diabetes, physical training, and their combination on the gene expression of proteins of putative titin stretch-sensing complexes in skeletal and cardiac muscle. Mice were divided into control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups performed for 1, 3, or 5 wk of endurance training on a motor-driven treadmill. Muscle samples from T and DT groups together with respective controls were collected 24 h after the last training session. Gene expression of calf muscles (soleus, gastrocnemius, and plantaris) and cardiac muscle were analyzed using microarray and quantitative PCR. Diabetes induced changes in mRNA expression of the proteins of titin stretch-sensing complexes in Z-disc (MLP, myostatin), I-band (CARP, Ankrd2), and M-line (titin kinase signaling). Training alleviated diabetes-induced changes in most affected mRNA levels in skeletal muscle but only one change in cardiac muscle. In conclusion, we showed diabetes-induced changes in mRNA levels of several fiber-type-biased proteins (MLP, myostatin, Ankrd2) in skeletal muscle. These results are consistent with previous observations of diabetes-induced atrophy leading to slower fiber type composition. The ability of exercise to alleviate diabetes-induced changes may indicate slower transition of fiber type.

scholarly journals Regulation of 4F2 heavy-chain gene expression during normal human T-cell activation can be mediated by multiple distinct molecular mechanisms.

1988 ◽  
Vol 8 (9) ◽  
pp. 3820-3826 ◽  
Author(s):  
T Lindsten ◽  
C H June ◽  
C B Thompson ◽  
J M Leiden
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Steady State ◽  
T Cell Activation ◽  
Cell Activation ◽  
Molecular Mechanisms ◽  
Transcription Elongation ◽  
Fold Increase ◽  
Mrna Levels ◽  
Myristate Acetate

The 4F2 molecule belongs to the set of cell surface antigens which is induced following lectin- or antigen-mediated T-cell activation. The increase in 4F2 cell surface expression following lectin-mediated stimulation has been shown to be accompanied by a parallel increase in the steady-state levels of 4F2 heavy-chain (4F2HC) mRNA. The studies described in this report were designed to further elucidate the molecular mechanisms responsible for induction of 4F2HC gene expression following activation of normal resting human peripheral blood T cells. The low levels of mature 4F2HC mRNA in resting T cells were shown to be the result of a block to transcription elongation within the exon 1-intron 1 region of the 4F2HC gene rather than promoter inactivity. Phorbol myristate acetate stimulation of resting T cells resulted in a 20-fold increase in steady-state 4F2HC mRNA levels which was mediated by removal of this block to transcription elongation. The phorbol myristate acetate-induced increase in 4F2HC gene expression is distinct from previously described AP-1-mediated, phorbol ester-induced gene expression in that it requires new protein synthesis. Treatment of resting T cells with ionomycin plus PMA resulted in a 60-fold increase in 4F2HC mRNA levels. This induction was mediated by both an increase in promoter utilization and removal of the block to transcription elongation. Finally, by increasing the half-life of 4F2HC mRNA, cycloheximide treatment of resting T cells induced an approximately five fold increase in the levels of 4F2HC gene expression, although the physiologic significance of this mechanism remains unclear. These results demonstrate that the level of 4F2HC gene expression in normal peripheral blood T cells can be regulated by at least three distinct molecular pathways: (i) changes in promoter utilization, (ii) modulation of a block to transcription elongation, and (iii) alteration in mRNA stability.

A role for calcium-calmodulin in regulating nitric oxide production during skeletal muscle satellite cell activation

2009 ◽  
Vol 296 (4) ◽  
pp. C922-C929 ◽  
Author(s):  
Ryuichi Tatsumi ◽  
Adam L. Wuollet ◽  
Kuniko Tabata ◽  
Shotaro Nishimura ◽  
Shoji Tabata ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Skeletal Muscle ◽  
Methyl Ester ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Cell Activation ◽  
Calcium Ionophore ◽  
Ester Hydrochloride ◽  
Methyl Ester Hydrochloride ◽  
Satellite Cell Activation

When skeletal muscle is stretched or injured, myogenic satellite cells are activated to enter the cell cycle. This process depends on nitric oxide (NO) production by NO synthase (NOS), matrix metalloproteinase activation, release of hepatocyte growth factor (HGF) from the extracellular matrix, and presentation of HGF to the c-met receptor as demonstrated by a primary culture and in vivo assays. We now add evidence that calcium-calmodulin is involved in the satellite cell activation cascade in vitro. Conditioned medium from cultures that were treated with a calcium ionophore (A23187, ionomycin) for 2 h activated cultured satellite cells and contained active HGF, similar to the effect of mechanical stretch or NO donor treatments. The response was abolished by addition of calmodulin inhibitors (calmidazolium, W-13, W-12) or a NOS inhibitor NG-nitro-l-arginine methyl ester hydrochloride but not by its less inactive enantiomer NG-nitro-d-arginine methyl ester hydrochloride. Satellite cells were also shown to express functional calmodulin protein having a calcium-binding activity at 12 h postplating, which is the time at which the calcium ionophore was added in this study and the stretch treatment was applied in our previous experiments. Therefore, results from these experiments provide an additional insight that calcium-calmodulin mediates HGF release from the matrix and that this step in the activation pathway is upstream from NO synthesis.

Transcriptional regulation of gene expression in human skeletal muscle during recovery from exercise

2000 ◽  
Vol 279 (4) ◽  
pp. E806-E814 ◽  
Author(s):  
Henriette Pilegaard ◽  
George A. Ordway ◽  
Bengt Saltin ◽  
P. Darrell Neufer
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Human Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Uncoupling Protein ◽  
Pyruvate Dehydrogenase Kinase ◽  
Heme Oxygenase 1 ◽  
Metabolic Efficiency ◽  
Vastus Lateralis Muscle ◽  
Mrna Levels

Exercise training elicits a number of adaptive changes in skeletal muscle that result in an improved metabolic efficiency. The molecular mechanisms mediating the cellular adaptations to exercise training in human skeletal muscle are unknown. To test the hypothesis that recovery from exercise is associated with transcriptional activation of specific genes, six untrained male subjects completed 60–90 min of exhaustive one-legged knee extensor exercise for five consecutive days. On day 5, nuclei were isolated from biopsies of the vastus lateralis muscle of the untrained and the trained leg before exercise and from the trained leg immediately after exercise and after 15 min, 1 h, 2 h, and 4 h of recovery. Transcriptional activity of the uncoupling protein 3 (UCP3), pyruvate dehydrogenase kinase 4 (PDK4), and heme oxygenase-1 (HO-1) genes (relative to β-actin) increased by three- to sevenfold in response to exercise, peaking after 1–2 h of recovery. Increases in mRNA levels followed changes in transcription, peaking between 2 and 4 h after exercise. Lipoprotein lipase and carnitine pamitoyltransferase I gene transcription and mRNA levels showed similar but less dramatic induction patterns, with increases ranging from two- to threefold. In a separate study, a single 4-h bout of cycling exercise ( n = 4) elicited from 5 to >20-fold increases in UCP3, PDK4, and HO-1 transcription, suggesting that activation of these genes may be related to the duration or intensity of exercise. These data demonstrate that exercise induces transient increases in transcription of metabolic genes in human skeletal muscle. Moreover, the findings suggest that the cumulative effects of transient increases in transcription during recovery from consecutive bouts of exercise may represent the underlying kinetic basis for the cellular adaptations associated with exercise training.

scholarly journals Fast skeletal muscle-specific expression of a quail troponin I gene in transgenic mice.

1988 ◽  
Vol 8 (12) ◽  
pp. 5072-5079 ◽  
Author(s):  
P L Hallauer ◽  
K E Hastings ◽  
A C Peterson
Keyword(s):  
Skeletal Muscle ◽  
Transgenic Mice ◽  
Troponin I ◽  
Fiber Type ◽  
Regulatory Elements ◽  
Evolutionary Divergence ◽  
Mrna Levels ◽  
Fast Skeletal Muscle ◽  
Specific Expression ◽  
Exon 2

We have produced seven lines of transgenic mice carrying the quail gene encoding the fast skeletal muscle-specific isoform of troponin I (TnIf). The quail DNA included the entire TnIf gene, 530 base pairs of 5'-flanking DNA, and 1.5 kilobase pairs of 3'-flanking DNA. In all seven transgenic lines, normally initiated and processed quail TnIf mRNA was expressed in skeletal muscle, where it accumulated to levels comparable to that in quail muscle. Moreover, in the three lines tested, quail TnIf mRNA levels were manyfold higher in a fast skeletal muscle (gastrocnemius) than in a slow skeletal muscle (soleus). We conclude that the cellular mechanisms directing muscle fiber type-specific TnIf gene expression are mediated by cis-regulatory elements present on the introduced quail DNA fragment and that they control TnIf expression by affecting the accumulation of TnIf mRNA. These elements have been functionally conserved since the evolutionary divergence of birds and mammals, despite the major physiological and morphological differences existing between avian (tonic) and mammalian (twitch) slow muscles. In lines of transgenic mice carrying multiple tandemly repeated copies of the transgene, an aberrant quail TnIf transcript (differing from normal TnIf mRNA upstream of exon 2) also accumulated in certain tissues, particularly lung, brain, spleen, and heart tissues. However, this aberrant transcript was not detected in a transgenic line which carries only a single copy of the quail gene.

scholarly journals Characterization and Regulation of Type A Endothelin Receptor Gene Expression in Bovine Luteal Cell Types

Endocrinology ◽  
1999 ◽  
Vol 140 (5) ◽  
pp. 2110-2116 ◽  
Author(s):  
Roni Mamluk ◽  
Nitzan Levy ◽  
Bo Rueda ◽  
John S. Davis ◽  
Rina Meidan
Keyword(s):  
Gene Expression ◽  
Receptor Gene ◽  
Cell Types ◽  
Cell Populations ◽  
Mrna Levels ◽  
Factor I ◽  
Receptor Mrna ◽  
Progesterone Production ◽  
Eta Receptor ◽  
Receptor Gene Expression

Abstract Our previous studies demonstrated that endothelin-1 (ET-1), a 21-amino acid vasoconstrictor peptide, has a paracrine regulatory role in bovine corpus luteum (CL). The peptide is produced within the gland where it inhibits progesterone production by acting via the selective type A endothelin (ETA) receptors. The present study was designed to characterize ETA receptor gene expression in different ovarian cell types and its hormonal regulation. ETA receptor messenger RNA (mRNA) levels were high in follicular cells as well as in CL during luteal regression. At this latter stage, high ETA receptor expression concurred with low prostaglandin F2α receptor mRNA. The ETA receptor gene was expressed by all three major cell populations of the bovine CL; i.e. small and large luteal cells, as well as in luteal endothelial cells. Among these various cell populations, the highest ETA receptor mRNA levels were found in endothelial cells. cAMP elevating agents, forskolin and LH, suppressed ETA receptor mRNA expression in luteinized theca cells (LTC). This inhibition was dose dependent and was evident already after 24 h of incubation. In luteinized granulosa cells (LGC), 10 and 100 ng/ml of insulin-like growth factor I and insulin (only at a concentration of 2000 ng/ml) markedly decreased ETA receptor mRNA levels. In both LGC and LTC there was an inverse relationship between ETA receptor gene expression and progesterone production; insulin (in LGC) and forskolin (in LTC) enhanced progesterone production while inhibiting ETA receptor mRNA levels. Our findings may therefore suggest that, during early stages of luteinization when peak levels of both LH and insulin-like growth factor I exist, the expression of ETA receptors in the gland are suppressed. This study demonstrates physiologically relevant regulatory mechanisms controlling ETA receptor gene expression and further supports the inhibitory role of ET-1 in CL function.

Screening of cervical cancer-related hub genes based on comprehensive bioinformatics analysis

2021 ◽  
pp. 1-13
Author(s):  
Simei Tu ◽  
Hao Zhang ◽  
Xiaocheng Yang ◽  
Wen Wen ◽  
Kangjing Song ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cervical Cancer ◽  
Molecular Mechanisms ◽  
Disease Free Survival ◽  
The Cancer Genome Atlas ◽  
Mrna Levels ◽  
Hub Genes ◽  
Normal Tissues ◽  
Significant Difference ◽  
Core Genes

BACKGROUND: Since the molecular mechanisms of cervical cancer (CC) have not been completely discovered, it is of great significance to identify the hub genes and pathways of this disease to reveal the molecular mechanisms of cervical cancer. OBJECTIVE: The study aimed to identify the biological functions and prognostic value of hub genes in cervical cancer. METHODS: The gene expression data of CC patients were downloaded from the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA) database. The core genes were screened out by differential gene expression analysis and weighted gene co-expression network analysis (WGCNA). R software, the STRING online tool and Cytoscape software were used to screen out the hub genes. The GEPIA public database was used to further verify the expression levels of the hub genes in normal tissues and tumour tissues and determine the disease-free survival (DFS) rates of the hub genes. The protein expression of the survival-related hub genes was identified with the Human Protein Atlas (HPA) database. RESULTS: A total of 64 core genes were screened, and 10 genes, including RFC5, POLE3, RAD51, RMI1, PALB2, HDAC1, MCM4, ESR1, FOS and E2F1, were identified as hub genes. Compared with that in normal tissues, RFC5, POLE3, RAD51,RMI1, PALB2, MCM4 and E2F1 were all significantly upregulated in cervical cancer, ESR1 was significantly downregulated in cervical cancer, and high RFC5 expression in CC patients was significantly related to OS. In the DFS analysis, no significant difference was observed in the expression level of RFC5 in cervical cancer patients. Finally, RFC5 protein levels verified by the HPA database were consistently upregulated with mRNA levels in CC samples. CONCLUSIONS: RFC5 may play important roles in the occurrence and prognosis of CC. It could be further explored and validated as a potential predictor and therapeutic target for CC.

Insights into the seasonal adaptive mechanisms of Chinese alligators (Alligator sinensis) from transcriptomic analyses

2018 ◽  
Vol 66 (2) ◽  
pp. 93 ◽  
Author(s):  
Hongji Sun ◽  
Xianbo Zuo ◽  
Long Sun ◽  
Peng Yan ◽  
Fang Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Molecular Mechanisms ◽  
Differentially Expressed ◽  
Model Organisms ◽  
Seasonal Adaptation ◽  
Cold Temperatures ◽  
Chinese Alligator ◽  
Adaptive Mechanisms ◽  
Alligator Sinensis

The Chinese alligator (Alligator sinensis) is an endemic and rare species in China, and is considered to be one of the most endangered vertebrates in the world. It is known to hibernate, an energy-saving strategy against cold temperatures and food deprivation. Changes in gene expression during hibernation remain largely unknown. To understand these complex seasonal adaptive mechanisms, we performed a comprehensive survey of differential gene expression in heart, skeletal muscle, and kidney of hibernating and active Chinese alligators using RNA-Sequencing. In total, we identified 4780 genes differentially expressed between the active and hibernating periods. GO and KEGG pathway analysis indicated the likely role of these differentially expressed genes (DEGs). The upregulated DEGs in the active Chinese alligator, CSRP3, MYG and PCKGC, may maintain heart and skeletal muscle contraction, transport and storage of oxygen, and enhance the body’s metabolism, respectively. The upregulated DEGs in the dormant Chinese alligator, ADIPO, CIRBP and TMM27, may improve insulin sensitivity and glucose/lipid metabolism, protect cells against harmful effects of cold temperature and hypoxia, regulate amino acid transport and uptake, and stimulate the proliferation of islet cells and the secretion of insulin. These results provide a foundation for understanding the molecular mechanisms of the seasonal adaptation required for hibernation in Chinese alligators, as well as effective information for other non-model organisms research.

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