scholarly journals Silencing of Mustn1 inhibits myogenic fusion and differentiation

2010 ◽  
Vol 298 (5) ◽  
pp. C1100-C1108 ◽  
Author(s):  
Cheng Liu ◽  
Robert P. Gersch ◽  
Thomas J. Hawke ◽  
Michael Hadjiargyrou
Keyword(s):  
Skeletal Muscles ◽  
Callus Tissue ◽  
Myogenic Differentiation ◽  
Myoblast Differentiation ◽  
Pcr Analysis ◽  
Fracture Callus ◽  
And Function ◽  
Multinucleated Myotubes ◽  
Myhc Expression

Mustn1 (Mustang, musculoskeletal temporally activated novel gene) was originally identified in fracture callus tissue, but its greatest expression is detected in skeletal muscle. Thus, we conducted experiments to investigate the expression and function of Mustn1 during myogenesis. Temporally, quantitative real-time PCR analysis of muscle samples from embryonic day 17 to 12 mo of age reveals that Mustn1 mRNA expression is greatest at 3 mo of age and beyond, consistent with the expression pattern of Myod. In situ hybridization shows abundant Mustn1 expression in somites and developing skeletal muscles, while in adult muscle, Mustn1 is localized to some peripherally located nuclei. Using RNA interference (RNAi), we investigated the function of Mustn1 in C2C12 myoblasts. Though silencing Mustn1 mRNA had no effect on myoblast proliferation, it did significantly impair myoblast differentiation, preventing myofusion. Specifically, when placed in low-serum medium for up to 6 days, Mustn1-silenced myoblasts elongated poorly and were mononucleated. In contrast, control RNAi-treated and parental myoblasts presented as large, multinucleated myotubes. Further supporting the morphological observations, immunocytochemistry of Mustn1-silenced cells demonstrated significant reductions in myogenin (Myog) and myosin heavy chain (Myhc) expression at 4 and 6 days of differentiation as compared with control and parental cells. The decreases in Myog and Myhc protein expression in Mustn1-silenced cells were associated with robust (∼3-fold or greater) decreases in the expression of Myod and desmin ( Des), as well as the myofusion markers calpain 1 ( Capn1), caveolin 3 ( Cav3), and cadherin 15 (M-cadherin; Cadh15). Overall, we demonstrate that Mustn1 is an essential regulator of myogenic differentiation and myofusion, and our findings implicate Myod and Myog as its downstream targets.

scholarly journals Chlorella vulgaris Improves the Regenerative Capacity of Young and Senescent Myoblasts and Promotes Muscle Regeneration

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Nurhazirah Zainul Azlan ◽  
Yasmin Anum Mohd Yusof ◽  
Ekram Alias ◽  
Suzana Makpol
Keyword(s):  
Chlorella Vulgaris ◽  
Muscle Regeneration ◽  
Myogenic Differentiation ◽  
Myoblast Differentiation ◽  
Regenerative Capacity ◽  
Maturation Index ◽  
Myoblast Cells ◽  
And Function ◽  
Pharmaceutical Uses

Sarcopenia is characterized by the loss of muscle mass, strength, and function with ageing. With increasing life expectancy, greater attention has been given to counteracting the effects of sarcopenia on the growing elderly population. Chlorella vulgaris, a microscopic, unicellular, green alga with the potential for various pharmaceutical uses, has been widely studied in this context. This study is aimed at determining the effects of C. vulgaris on promoting muscle regeneration by evaluating myoblast regenerative capacity in vitro. Human skeletal myoblast cells were cultured and underwent serial passaging into young and senescent phases and were then treated with C. vulgaris, followed by the induction of differentiation. The ability of C. vulgaris to promote myoblast differentiation was analysed through cellular morphology, real-time monitoring, cell proliferation, senescence-associated β-galactosidase (SA-β-gal) expression, myogenic differentiation, myogenin expression, and cell cycle profiling. The results obtained showed that senescent myoblasts exhibited an enlarged and flattened morphology, with increased SA-β-gal expression, reduced myogenic differentiation, decreased expression of myogenin, and an increased percentage of cells in the G0/G1 phase. Treatment with C. vulgaris resulted in decreased SA-β-gal expression and promotion of myogenic differentiation, as observed via an increased fusion index, maturation index, myotube size, and surface area and an increased percentage of cells that stained positive for myogenin. In conclusion, C. vulgaris improves the regenerative capacity of young and senescent myoblasts and promotes myoblast differentiation, indicating its potential to promote muscle regeneration.

scholarly journals MyoD induced enhancer RNA interacts with hnRNPL to activate target gene transcription during myogenic differentiation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yu Zhao ◽  
Jiajian Zhou ◽  
Liangqiang He ◽  
Yuying Li ◽  
Jie Yuan ◽  
...  
Keyword(s):  
Target Gene ◽  
Myogenic Differentiation ◽  
Myoblast Differentiation ◽  
Enhancer Rna ◽  
Super Enhancer ◽  
And Function ◽  
Nuclear Ribonucleoprotein ◽  
Multiple Cells

AbstractEmerging evidence supports roles of enhancer RNAs (eRNAs) in regulating target gene. Here, we study eRNA regulation and function during skeletal myoblast differentiation. We provide a panoramic view of enhancer transcription and categorization of eRNAs. Master transcription factor MyoD is crucial in activating eRNA production. Super enhancer (se) generated seRNA-1 and -2 promote myogenic differentiation in vitro and in vivo. seRNA-1 regulates expression levels of two nearby genes, myoglobin (Mb) and apolipoprotein L6 (Apol6), by binding to heterogeneous nuclear ribonucleoprotein L (hnRNPL). A CAAA tract on seRNA-1 is essential in mediating seRNA-1/hnRNPL binding and function. Disruption of seRNA-1-hnRNPL interaction attenuates Pol II and H3K36me3 deposition at the Mb locus, in coincidence with the reduction of its transcription. Furthermore, analyses of hnRNPL binding transcriptome-wide reveal its association with eRNAs is a general phenomenon in multiple cells. Collectively, we propose that eRNA-hnRNPL interaction represents a mechanism contributing to target mRNA activation.

scholarly journals Aronia Upregulates Myogenic Differentiation and Augments Muscle Mass and Function Through Muscle Metabolism

2021 ◽  
Vol 8 ◽  
Author(s):  
Chae-Eun Yun ◽  
Hyun-Kyung So ◽  
Tuan Anh Vuong ◽  
Myung Woo Na ◽  
Subin Anh ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Myogenic Differentiation ◽  
Muscle Metabolism ◽  
Akt Activation ◽  
Inflammatory Conditions ◽  
Aronia Melanocarpa ◽  
Metabolic Functions ◽  
Black Chokeberry ◽  
And Function ◽  
Multinucleated Myotubes

Black chokeberry or aronia (the fruit of Aronia melanocarpa) has been reported to having pharmacological activities against metabolic syndrome, such as hypertension, obesity, diabetes, and pro-inflammatory conditions. However, the effects of aronia on myogenic differentiation and muscle homoeostasis are uncharacterized. In this study, we investigated the effects of aronia (black chokeberry) on myogenic differentiation and muscle metabolic functions in young mice. Aronia extract (AR) promotes myogenic differentiation and elevates the formation of multinucleated myotubes through Akt activation. AR protects dexamethasone (DEX)-induced myotube atrophy through inhibition of muscle-specific ubiquitin ligases mediated by Akt activation. The treatment with AR increases muscle mass and strength in mice without cardiac hypertrophy. AR treatment enhances both oxidative and glycolytic myofibers and muscle metabolism with elevated mitochondrial genes and glucose metabolism-related genes. Furthermore, AR-fed muscle fibers display increased levels of total OxPHOS and myoglobin proteins. Taken together, AR enhances myogenic differentiation and improves muscle mass and function, suggesting that AR has a promising potential as a nutraceutical remedy to intervene in muscle weakness and atrophy.

Identification of the crucial molecular events during the large-scale myoblast fusion in sheep

2014 ◽  
Vol 46 (12) ◽  
pp. 429-440 ◽  
Author(s):  
Caihong Wei ◽  
Li Li ◽  
Hongwei Su ◽  
Lingyang Xu ◽  
Jian Lu ◽  
...  
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Muscle Development ◽  
Target Genes ◽  
Myogenic Differentiation ◽  
Myoblast Fusion ◽  
Myoblast Differentiation ◽  
Pcr Analysis ◽  
Fetal Sheep ◽  
Fetal Muscle

It is well known that in sheep most myofibers are formed before birth; however, the crucial myogenic stage and the cellular and molecular mechanisms underpinning phenotypic variation of fetal muscle development remain to be ascertained. We used histological, microarray, and quantitative real-time PCR (qPCR) methods to examine the developmental characteristics of fetal muscle at 70, 85, 100, 120, and 135 days of gestation in sheep. We show that day 100 is an important checkpoint for change in muscle transcriptome and histomorphology in fetal sheep and that the period of 85–100 days is the vital developmental stage for large-scale myoblast fusion. Furthermore, we identified the cis-regulatory motifs for E2F1 or MEF2A in a list of decreasingly or increasingly expressed genes between 85 and 100 days, respectively. Further analysis demonstrated that the mRNA and phosphorylated protein levels of E2F1 and MEF2A significantly declined with myogenic progression in vivo and in vitro. qRT-PCR analysis indicated that PI3K and FST, as targets of E2F1, may be involved in myoblast differentiation and fusion and that downregulation of MEF2A contributes to transition of myofiber types by differential regulation of the target genes involved at the stage of 85–100 days. We clarify for the first time the timing of myofiber proliferation and development during gestation in sheep, which would be beneficial to meat sheep production. Our findings present a repertoire of gene expression in muscle during large-scale myoblast fusion at transcriptome-wide level, which contributes to elucidate the regulatory network of myogenic differentiation.

scholarly journals Requirement for PINCH in Skeletal Myoblast Differentiation

2021 ◽  
Author(s):  
Siyi Xie ◽  
Chushan Fang ◽  
Yujie Gao ◽  
Jie Yan ◽  
Lina Luo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Skeletal Muscles ◽  
Molecular Mechanisms ◽  
Myogenic Differentiation ◽  
Critical Role ◽  
The Body ◽  
Myoblast Differentiation ◽  
Skeletal Myogenesis ◽  
Congenital Myopathies

Abstract Background: Skeletal muscle is composed of bundles of myofibers ensheathed by extracellular matrix networks. Malformation of skeletal muscle during embryonic development results in congenital myopathies. Disease mechanisms of congenital myopathies remain unclear. PINCH, an adaptor of focal adhesion complex, plays essential roles in multiple cellular processes and organogenesis. Elucidation of the molecular mechanisms underlying skeletal myogenesis will offer new insights into pathogenesis of myopathies.Methods: We generated muscle-specific PINCH knock-out mice to study the functional role of PINCH in skeletal myogenesis. Histologic and Transmission Electron Microscopy analysis demonstrated that Impaired myogenic differentiation and maturation in mice with PINCH1 being ablated in skeletal muscle progenitors, and Ablation of PINCH1 and PINCH2 resulted in reduced size of muscle fibers and impaired multinucleation; Cell culture and immunostaining showed that defects in myoblast fusion and cytoskeleton assembly in PINCH double mutant mice; Western blotting showed that defects in expression of cytoskeleton proteins and proteins involved in myogenesis in DMUT skeletal muscles.Results: Double ablation of PINCH1 and PINCH2 resulted in early postnatal lethality with reduced size of skeletal muscles and detachment of diaphragm muscles from the body wall. Myofibers of PINCH mutant myofibers failed to undergo multinucleation and exhibited disrupted sarcomere structures. The mutant myoblasts in culture were able to adhere to newly formed myotubes, but impeded in cell fusion and subsequent sarcomere genesis and cytoskeleton organization. Consistent with this, expression of integrin β1 and some cytoskeleton proteins, and phosphorylation of ERK and AKT were significantly reduced in PINCH mutants. Expression of MRF4, the most highly expressed myogenic factor at late stages of myogenesis, was abolished in PINCH mutants, that could contribute to observed phenotypes. In addition, mice with PINCH1 being ablated in myogenic progenitors exhibited only mild centronuclear myopathic changes, suggesting a compensatory role of PINCH2 in myogenic differentiation, indicating a critical role of PINCH proteins in myogenic differentiation.Conclusion: Our results demonstrated an essential role of PINCH in skeletal myogenic differentiation.

Correlation Between Nanoindentation Modulus and Mineral Density in Fracture Callus Tissues

2008 ◽  
Author(s):  
Pui Leng Leong ◽  
Elise F. Morgan
Keyword(s):  
Mechanical Properties ◽  
Callus Tissue ◽  
Mechanical Stability ◽  
Mineral Density ◽  
Fracture Callus ◽  
Non Invasive ◽  
Healing Fracture ◽  
Healing Bone ◽  
Callus Tissues ◽  
And Function

The stiffness and strength of a healing bone fracture depend on the geometry of the fracture callus as well as the mechanical properties of the callus tissues. In the clinical setting, the mechanical stability of a healing fracture is often estimated qualitatively based on the radioopacity of the callus tissue. However, a quantitative association between tissue mineralization and mechanical properties has yet to be established for these tissues. Quantifying callus tissue material properties and mineral content may therefore enable improved non-invasive assessments of bone healing. In addition, elucidating relationships between callus tissue composition and function will provide a means of understanding the mechanism by which the injured bone recovers its mechanical integrity.

scholarly journals Rbm24 Displays Dynamic Functions Required for Myogenic Differentiation During Muscle Regeneration

2020 ◽  
Author(s):  
Raphaëlle Grifone ◽  
Audrey Saquet ◽  
Manon Desgres ◽  
Claudia Sangiorgi ◽  
Caterina Gargano ◽  
...  
Keyword(s):  
Muscle Regeneration ◽  
Muscle Development ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Myogenic Differentiation ◽  
Regulation Of Gene Expression ◽  
Repair Process ◽  
Myoblast Differentiation ◽  
Adult Mice ◽  
And Function

Abstract Skeletal muscle has a remarkable capacity of regeneration after injury, but the cellular behavior and the regulatory network coordinating different steps of this repair process remain elusive. RNA-binding proteins play key roles in the post-transcriptional regulation of gene expression and are implicated in the maintenance of tissue homeostasis and plasticity. Rbm24 is required for myogenic differentiation during early development, but its function in adult muscle is open for investigation. Here we show that it exerts dynamic functions during muscle regeneration in mice. Consistent with its dynamic subcellular localization during embryonic muscle development, Rbm24 also displays cytoplasm to nucleus translocation during the differentiation of C2C12 myoblasts. In adult mice, Rbm24 mRNA is highly expressed in slow-twitch muscles, and Rbm24 protein is restricted to the myonucleus of myofibers. Upon injury, Rbm24 protein is upregulated in regenerating myofibers and rapidly accumulates in the myonucleus of nascent myofibers. By using satellite cell transplantation, we find that Rbm24 functions sequentially to regulate the differentiation of myofibers and the regeneration of damaged tissues. It is required for myogenin mRNA expression at early stages of muscle injury and for muscle-specific pre-mRNA alternative splicing at late stages of regeneration. These results identify Rbm24 as a multifaceted regulator of myoblast differentiation and function. They also provide insights into the molecular pathway orchestrating the expression of myogenic factors and muscle functional proteins during regeneration.

scholarly journals Network analysis of the left anterior descending coronary arteries in swim-trained rats by an in situ video microscopic technique

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Marianna Török ◽  
Petra Merkely ◽  
Anna Monori-Kiss ◽  
Eszter Mária Horváth ◽  
Réka Eszter Sziva ◽  
...  
Keyword(s):  
Sex Differences ◽  
Left Ventricular ◽  
Resistance Artery ◽  
Frequency Spectra ◽  
Stress Markers ◽  
Lv Mass ◽  
Network Properties ◽  
Exercise Induced ◽  
And Function

Abstract Background We aimed to identify sex differences in the network properties and to recognize the geometric alteration effects of long-term swim training in a rat model of exercise-induced left ventricular (LV) hypertrophy. Methods Thirty-eight Wistar rats were divided into four groups: male sedentary, female sedentary, male exercised and female exercised. After training sessions, LV morphology and function were checked by echocardiography. The geometry of the left coronary artery system was analysed on pressure-perfused, microsurgically prepared resistance artery networks using in situ video microscopy. All segments over > 80 μm in diameter were studied using divided 50-μm-long cylindrical ring units of the networks. Oxidative-nitrative (O-N) stress markers, adenosine A2A and estrogen receptor (ER) were investigated by immunohistochemistry. Results The LV mass index, ejection fraction and fractional shortening significantly increased in exercised animals. We found substantial sex differences in the coronary network in the control groups and in the swim-trained animals. Ring frequency spectra were significantly different between male and female animals in both the sedentary and trained groups. The thickness of the wall was higher in males as a result of training. There were elevations in the populations of 200- and 400-μm vessel units in males; the thinner ones developed farther and the thicker ones closer to the orifice. In females, a new population of 200- to 250-μm vessels appeared unusually close to the orifice. Conclusions Physical activity and LV hypertrophy were accompanied by a remodelling of coronary resistance artery network geometry that was different in both sexes.

scholarly journals Ultrafine metal-polymer catalysts based on polyconjugated systems for Fisher–Tropsch synthesis

2020 ◽  
Vol 92 (6) ◽  
pp. 977-984
Author(s):  
Mayya V. Kulikova ◽  
Albert B. Kulikov ◽  
Alexey E. Kuz’min ◽  
Anton L. Maximov
Keyword(s):  
Tropsch Synthesis ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
Force Microscopy ◽  
Composite Catalysts ◽  
Fe Catalyst ◽  
Atomic Force ◽  
And Function ◽  
Metal Polymer

AbstractFor previously studied Fischer–Tropsch nanosized Fe catalyst slurries, polymer compounds with or without polyconjugating structures are used as precursors to form the catalyst nanomatrix in situ, and several catalytic experiments and X-ray diffraction and atomic force microscopy measurements are performed. The important and different roles of the paraffin molecules in the slurry medium in the formation and function of composite catalysts with the two types of aforementioned polymer matrices are revealed. In the case of the polyconjugated polymers, the alkanes in the medium are “weakly” coordinated with the metal-polymer composites, which does not affect the effectiveness of the polyconjugated polymers. Otherwise, alkane molecules form a “tight” surface layer around the composite particles, which create transport complications for the reagents and products of Fischer-Tropsch synthesis and, in some cases, can change the course of the in situ catalyst formation.

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