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BMC Pharmacology & Toxicology May 2016Humans are exposed to nitrate predominantly through diet with peak plasma concentrations within an hour after ingestion, but additional exposure is obtained from the...
BACKGROUND
Humans are exposed to nitrate predominantly through diet with peak plasma concentrations within an hour after ingestion, but additional exposure is obtained from the environment, and minimally through de novo synthesis. Higher nitrate consumption has been associated with methemoglobinemia, spontaneous abortions, atherosclerosis, myocardial ischemia, septic and distressed lung, inflammatory bowel disease, amyotrophic lateral sclerosis, and neural tube defects. However, skeletal muscle development has not been examined.
METHODS
C2C12 skeletal muscle cell cultures were maintained, myoblasts were fused into myotubes, and then cultures were exposed to motor neuron derived agrin to enhance acetylcholine receptor (AChR) clustering. Untreated cultures were compared with cultures exposed to sodium nitrate at concentrations ranging from 10 ng/mL-100 μg/mL.
RESULTS
The results reported here demonstrate that 1 μg/mL sodium nitrate was sufficient to decrease the frequency of agrin-induced AChR clustering without affecting myotube formation. In addition, concentrations of sodium nitrate of 1 μg/mL or 100 μg/mL decreased gene expression of the myogenic transcription factor myogenin and AChR in correlation with the agrin-induced AChR clustering data.
CONCLUSIONS
These results reveal that sodium nitrate decreases the frequency of agrin-induced AChR clustering by a mechanism that includes myogenin and AChR gene expression. As a consequence sodium nitrate may pose a risk for skeletal muscle development and subsequent neuromuscular synapse formation in humans.
Topics: Agrin; Animals; Cells, Cultured; Cluster Analysis; Dose-Response Relationship, Drug; Mice; Muscle Fibers, Skeletal; Myoblasts, Skeletal; Nitrates; Receptors, Cholinergic
PubMed: 27132129
DOI: 10.1186/s40360-016-0062-0 -
Indian Journal of Pathology &... Jul 2023Pseudomyogenic hemangioendothelioma (PHE) is an uncommon mesenchymal neoplasm of intermediate malignant potential showing endothelial differentiation. Around 20 cases of...
Pseudomyogenic hemangioendothelioma (PHE) is an uncommon mesenchymal neoplasm of intermediate malignant potential showing endothelial differentiation. Around 20 cases of primary osseous PHE have been reported to date. A 16-year-old boy presented with complaints of pain in his right leg. Imaging revealed multifocal intramedullary and cortical-based lytic lesions involving long and small bones. Microscopic examination revealed plump, spindled cells arranged in fascicles and admixed "epithelioid" and "rhabdoid" cells sans vasoformative areas. By immunohistochemistry, the lesional cells were reactive for AE1/AE3, CD31, Erg, Fli1, and SMA, while immunonegative for CD34, myogenin, and S100. Nuclear expression of the INI1/SMARCB1 protein was retained. PHE is a rare entity, more so as a primary osseous lesion; therefore, awareness of the presence of this entity in the bone is the key to making a diagnosis. We discuss its clinicopathological features, differential diagnosis, and an attempt a short review of the literature.
PubMed: 38391317
DOI: 10.4103/ijpm.ijpm_995_22 -
Nature Communications Oct 2018Each skeletal muscle acquires its unique size before birth, when terminally differentiating myocytes fuse to form a defined number of multinucleated myofibres. Although...
Each skeletal muscle acquires its unique size before birth, when terminally differentiating myocytes fuse to form a defined number of multinucleated myofibres. Although mice in which the transcription factor Myogenin is mutated lack most myogenesis and die perinatally, a specific cell biological role for Myogenin has remained elusive. Here we report that loss of function of zebrafish myog prevents formation of almost all multinucleated muscle fibres. A second, Myogenin-independent, fusion pathway in the deep myotome requires Hedgehog signalling. Lack of Myogenin does not prevent terminal differentiation; the smaller myotome has a normal number of myocytes forming more mononuclear, thin, albeit functional, fast muscle fibres. Mechanistically, Myogenin binds to the myomaker promoter and is required for expression of myomaker and other genes essential for myocyte fusion. Adult myog mutants display reduced muscle mass, decreased fibre size and nucleation. Adult-derived myog mutant myocytes show persistent defective fusion ex vivo. Myogenin is therefore essential for muscle homeostasis, regulating myocyte fusion to determine both muscle fibre number and size.
Topics: Animals; Cells, Cultured; Chromatin Immunoprecipitation; Embryo, Nonmammalian; Female; Male; Muscle Cells; Myogenin; NADH Tetrazolium Reductase; RNA, Messenger; Reverse Transcriptase Polymerase Chain Reaction; Zebrafish
PubMed: 30315160
DOI: 10.1038/s41467-018-06583-6 -
Mechanical ventilation regulated the differentiation and proliferation of diaphragm satellite cells.Frontiers in Bioscience (Landmark... Nov 2021: This study aimed to determine the effect of mechanical ventilation (MV) on the differentiation and proliferation of diaphragm satellite cells. : Diaphragm satellite...
: This study aimed to determine the effect of mechanical ventilation (MV) on the differentiation and proliferation of diaphragm satellite cells. : Diaphragm satellite cells were isolated from C57 mice receiving 6 h of MV with optimized magnetic-activated cell sorting (MACS) approach. The cells were stained with BrdU or antibody for differentiation marker MYH3. The expression of MyoD and myogenin was detected by real-time PCR. : Diaphragm satellite cells were successfully isolated from mice by using MACS with a set of optimized parameters. About 1.5 × 10 cells could be harvested from a diaphragm. Upon MV, the proliferation rate of diaphragm satellite cells was decreased from 88.74% to 81.92%, while the differentiation rate was increased from 17.94% to 27.58%, compared to controls. Moreover, the expression of MyoD and myogenin were significantly upregulated upon MV. : We established a practical method to purify diaphragm satellite cells, and demonstrated that MV regulated the differentiation and proliferation of diaphragm satellite cells.
Topics: Animals; Cell Differentiation; Cell Proliferation; Diaphragm; Mice; MyoD Protein; Respiration, Artificial; Satellite Cells, Skeletal Muscle
PubMed: 34856749
DOI: 10.52586/5005 -
Skeletal Muscle Feb 2018Tyrosine kinase inhibitors (TKIs) are effective therapies with demonstrated antineoplastic activity. Nilotinib is a second-generation FDA-approved TKI designed to...
BACKGROUND
Tyrosine kinase inhibitors (TKIs) are effective therapies with demonstrated antineoplastic activity. Nilotinib is a second-generation FDA-approved TKI designed to overcome Imatinib resistance and intolerance in patients with chronic myelogenous leukemia (CML). Interestingly, TKIs have also been shown to be an efficient treatment for several non-malignant disorders such fibrotic diseases, including those affecting skeletal muscles.
METHODS
We investigated the role of Nilotinib on skeletal myogenesis using the well-established C2C12 myoblast cell line. We evaluated the impact of Nilotinib during the time course of skeletal myogenesis. We compared the effect of Nilotinib with the well-known p38 MAPK inhibitor SB203580. MEK1/2 UO126 and PI3K/AKT LY294002 inhibitors were used to identify the signaling pathways involved in Nilotinib-related effects on myoblast. Adult primary myoblasts were also used to corroborate the inhibition of myoblasts fusion and myotube-nuclei positioning by Nilotinib.
RESULTS
We found that Nilotinib inhibited myogenic differentiation, reducing the number of myogenin-positive myoblasts and decreasing myogenin and MyoD expression. Furthermore, Nilotinib-mediated anti-myogenic effects impair myotube formation, myosin heavy chain expression, and compromise myotube-nuclei positioning. In addition, we found that p38 MAPK is a new off-target protein of Nilotinib, which causes inhibition of p38 phosphorylation in a similar manner as the well-characterized p38 inhibitor SB203580. Nilotinib induces the activation of ERK1/2 and AKT on myoblasts but not in myotubes. We also found that Nilotinib stimulates myoblast proliferation, a process dependent on ERK1/2 and AKT activation.
CONCLUSIONS
Our findings suggest that Nilotinib may have important negative effects on muscle homeostasis, inhibiting myogenic differentiation but stimulating myoblasts proliferation. Additionally, we found that Nilotinib stimulates the activation of ERK1/2 and AKT. On the other hand, we suggest that p38 MAPK is a new off-target of Nilotinib. Thus, there is a necessity for future studies to investigate the long-term effects of TKIs on skeletal muscle homeostasis, along with potential detrimental effects in cell differentiation and proliferation in patients receiving TKI therapies.
Topics: Animals; Apoptosis; Cell Differentiation; Cell Proliferation; Cells, Cultured; Gene Expression Regulation; MAP Kinase Signaling System; Mice, Inbred C57BL; Muscle Development; Muscle Fibers, Skeletal; Myoblasts, Skeletal; Myogenin; Phosphorylation; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proteostasis; Proto-Oncogene Proteins c-akt; Pyrimidines; RNA, Messenger; p38 Mitogen-Activated Protein Kinases
PubMed: 29463296
DOI: 10.1186/s13395-018-0150-5 -
Scientific Reports Apr 2017Muscle wasting or sarcopenia contributes to morbidity and mortality in patients with cancer, renal failure, or heart failure, and in elderly individuals. Na-K-2Cl...
Muscle wasting or sarcopenia contributes to morbidity and mortality in patients with cancer, renal failure, or heart failure, and in elderly individuals. Na-K-2Cl cotransporter 1 (NKCC1) is highly expressed in mammalian skeletal muscle, where it contributes to the generation of membrane ion currents and potential. However, the physiologic function of NKCC1 in myogenesis is unclear. We investigated this issue using the NKCC1 inhibitors bumetanide and furosemide, which are commonly used loop diuretics. NKCC1 protein levels increased during C2C12 murine skeletal myoblast differentiation, similarly to those of the myogenic markers myogenin and myosin heavy chain (MHC). NKCC1 inhibitors markedly suppressed myoblast fusion into myotubes and the expression of myogenin and MHC. Furthermore, phosphorylated and total NKCC1 levels were elevated in mouse skeletal muscles after 6 weeks' voluntary wheel running. Immunofluorescence analyses of myofiber cross-sections revealed more large myofibers after exercise, but this was impaired by daily intraperitoneal bumetanide injections (0.2 or 10 mg/kg/day). NKCC1 plays an essential role in myogenesis and exercise-induced skeletal muscle hypertrophy, and sarcopenia in patients with renal or heart failure may be attributable to treatment with loop diuretics.
Topics: Animals; Bumetanide; Cell Differentiation; Cell Line; Disease Models, Animal; Diuretics; Furosemide; Injections, Intraperitoneal; Mice; Myoblasts; Phosphorylation; Running; Sarcopenia; Solute Carrier Family 12, Member 2; Up-Regulation
PubMed: 28417963
DOI: 10.1038/srep46369 -
BioRxiv : the Preprint Server For... Aug 2023Bioelectricity is an understudied phenomenon to guide tissue homeostasis and regeneration. Conductive biomaterials may capture native or exogenous bioelectric signaling,...
Bioelectricity is an understudied phenomenon to guide tissue homeostasis and regeneration. Conductive biomaterials may capture native or exogenous bioelectric signaling, but incorporation of conductive moieties is limited by cytotoxicity, poor injectability, or insufficient stimulation. Microgel annealed scaffolds are promising as hydrogel-based materials due to their inherent void space that facilitates cell migration and proliferation better than nanoporous bulk hydrogels. We generated conductive microgels from poly(ethylene) glycol and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) to explore the interplay of void volume and conductivity on myogenic differentiation. PEDOT:PSS increased microgel conductivity over 2-fold while maintaining stiffness, annealing strength, and viability of associated myoblastic cells. C2C12 myoblasts exhibited increases in the late-stage differentiation marker myosin heavy chain as a function of both porosity and conductivity. Myogenin, an earlier marker, was influenced only by porosity. Human skeletal muscle derived cells exhibited increased , IGF-1, and IGFBP-2 at earlier timepoints on conductive microgel scaffolds compared to non-conductive scaffolds. They also secreted higher levels of VEGF at early timepoints and expressed factors that led to macrophage polarization patterns observed during muscle repair. These data indicate that conductivity aids myogenic differentiation of myogenic cell lines and primary cells, motivating the need for future translational studies to promote muscle repair.
PubMed: 37577583
DOI: 10.1101/2023.08.01.551533 -
Data in Brief Apr 2021The present work benefits the use of sodium tetraborate to prevent and treat hypertrophic cardiac. The data obtained from the work could serve as a reference point to...
The present work benefits the use of sodium tetraborate to prevent and treat hypertrophic cardiac. The data obtained from the work could serve as a reference point to compare with data obtained in vivo studies with cardiac damage. This research will be an advantage for future researches to stimulate the ones focused on developing food supplements to prevent heart diseases such as cardiac hypertrophic. This article also indicates the data on the optimal concentration of isoproterenol as an inducer of hypertrophy in cardiomyocytes. Also, data of the cytotoxic effect of sodium tetraborate on normal cardiomyocytes is revealed. Finally, data of viability, cell size, proliferation nuclear antigen (PCNA) and apoptosis is shown. The expression of transcription factors linked to hypertrophy such as GATA-4, MEF2c, NFAT, CDk9, and myogenin was also quantified by immunofluorescence. The mRNA expression of adrenergic receptors (alpha and beta), AKT1 and Erk1 / 2 and genes of early response to hypertrophy () are also shown as Cts of RT-qPCR. GAPDH and 18 s were used as housekeeping genes.
PubMed: 33850976
DOI: 10.1016/j.dib.2021.106889 -
American Journal of Physiology.... Dec 2019The aim of this study was to examine the activation of skeletal muscle signaling pathways related to protein synthesis and the gene expression of...
The aim of this study was to examine the activation of skeletal muscle signaling pathways related to protein synthesis and the gene expression of regeneration/degradation markers following repeated bouts of eccentric cycling. Nine untrained men (25.4 ± 1.9 yr) performed two 30-min eccentric cycling bouts (ECC1, ECC2) at 85% of maximal concentric workload, separated by 2 wk. Muscle biopsies were taken from the vastus lateralis before and 2 h after each bout. Indirect markers of muscle damage were assessed before and 24-48 h after exercise. Changes in the Akt/mammalian target of rapamycin (mTOR)/rbosomal protein S6 kinase 1 (S6K1)/ribosomal protein S6 (rpS6) and MAPK signaling pathways were measured by Western blot and changes in mRNA expression of IL-6 and IL-1β, and myogenic regulatory factors (MRFs) were measured by real-time PCR. ECC1 induced greater increases in indirect markers of muscle damage compared with ECC2. Phosphorylation of S6K1 and rpS6 increased after both exercise bouts ( < 0.05), whereas phosphorylation of mTOR increased after ECC2 only ( = 0.03). Atrogin-1 mRNA expression decreased after ECC1 and ECC2 ( < 0.05) without changes in muscle RING-finger protein-1 mRNA. Basal mRNA levels of myoblast determination protein-1 (MyoD), MRF4, and myogenin were higher 2 wk after ECC1 ( < 0.05). MRF4 mRNA increased after ECC1 and ECC2 ( < 0.05), whereas MyoD mRNA expression increased only after ECC1 ( = 0.03). Phosphorylation of JNK and p38 MAPK increased after both exercise bouts ( < 0.05), similar to IL-6 and IL-1β mRNA expression. All together, these results suggest that differential regulation of the mTOR pathway and MRF expression could mediate the repeated bout effect observed between an initial and secondary bout of eccentric exercise.
Topics: Adult; Bicycling; Exercise; Gene Expression; Humans; Interleukin-1beta; Interleukin-6; MAP Kinase Kinase 4; MAP Kinase Signaling System; Male; Muscle Proteins; Muscle, Skeletal; MyoD Protein; Myogenic Regulatory Factors; Myogenin; Protein Biosynthesis; Proto-Oncogene Proteins c-akt; Quadriceps Muscle; Regeneration; Ribosomal Protein S6; Ribosomal Protein S6 Kinases, 90-kDa; SKP Cullin F-Box Protein Ligases; TOR Serine-Threonine Kinases; Tripartite Motif Proteins; Ubiquitin-Protein Ligases; Young Adult; p38 Mitogen-Activated Protein Kinases
PubMed: 31593504
DOI: 10.1152/ajpendo.00216.2019 -
Animal : An International Journal of... Jul 2016Poor maternal nutrition inhibits muscle development and postnatal muscle growth. Satellite cells are myogenic precursor cells that contribute to postnatal muscle growth,...
Poor maternal nutrition inhibits muscle development and postnatal muscle growth. Satellite cells are myogenic precursor cells that contribute to postnatal muscle growth, and their activity can be evaluated by the expression of several transcription factors. Paired-box (Pax)7 is expressed in quiescent and active satellite cells. MyoD is expressed in activated and proliferating satellite cells and myogenin is expressed in terminally differentiating cells. Disruption in the expression pattern or timing of expression of myogenic regulatory factors negatively affects muscle development and growth. We hypothesized that poor maternal nutrition during gestation would alter the in vitro temporal expression of MyoD and myogenin in satellite cells from offspring at birth and 3 months of age. Ewes were fed 100% or 60% of NRC requirements from day 31±1.3 of gestation. Lambs from control-fed (CON) or restricted-fed (RES) ewes were euthanized within 24 h of birth (birth; n=5) or were fed a control diet until 3 months of age (n=5). Satellite cells isolated from the semitendinosus muscle were used for gene expression analysis or cultured for 24, 48 or 72 h and immunostained for Pax7, MyoD or myogenin. Fusion index was calculated from a subset of cells allowed to differentiate. Compared with CON, temporal expression of MyoD and myogenin was altered in cultured satellite cells isolated from RES lambs at birth. The percent of cells expressing MyoD was greater in RES than CON (P=0.03) after 24 h in culture. After 48 h of culture, there was a greater percent of cells expressing myogenin in RES compared with CON (P0.05). In satellite cells from RES lambs at 3 months of age, the percent of cells expressing MyoD and myogenin were greater than CON after 72 h in culture (P<0.05). Fusion index was reduced in RES lambs at 3 months of age compared with CON (P<0.001). Restricted nutrition during gestation alters the temporal expression of myogenic regulatory factors in satellite cells of the offspring, which may reduce the pool of myoblasts, decrease myoblast fusion and contribute to the poor postnatal muscle growth previously observed in these animals.
Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Cell Differentiation; Diet; Female; Gene Expression Regulation; Maternal Nutritional Physiological Phenomena; Muscle Development; Myoblasts; Myogenic Regulatory Factors; Myogenin; Pregnancy; Prenatal Exposure Delayed Effects; Satellite Cells, Skeletal Muscle; Sheep
PubMed: 26856892
DOI: 10.1017/S1751731116000070