scholarly journals Multinucleation of Skeletal Muscle in vitro

1960 ◽  
Vol 7 (3) ◽  
pp. 559-565 ◽  
Author(s):  
Charles R. Capers
Keyword(s):  
Muscle Development ◽  
Horse Serum ◽  
Muscle Fibers ◽  
Time Lapse ◽  
Nuclear Migration ◽  
Myoblast Fusion ◽  
Mitochondrial Activity ◽  
Sequence Of Events ◽  
Membrane Wrinkling

Healthy, mature, spontaneously contracting muscle was cultivated from explants of 13-day chick embryos for periods up to 4 months in the multipurpose chamber (Rose, 1954) using cellophane-strip technique (Rose et al., 1958) with silicone gaskets, Eagle's medium including 10 per cent horse serum reinforced with 300 mg-per cent of glucose, and the teased type of explant. This method provided optically ideal conditions for the study of muscle fibers with oil immersion, phase contrast time-lapse cinematography at 1 frame per minute without apparent damage for periods as long as 10 days. In no case was mitosis, amitosis, or nuclear "budding" observed in the course of muscle development. Multinuclear muscle fibers have been shown with cine technique to result from both myoblast fusion and polar extension of preformed (explanted) muscle tissue. Myoblast fusion was the only demonstrable way of giving rise to multinucleation. Nuclear membrane "wrinkling" was shown to be merely a temporary distortion that occurred during nuclear migration and rotation. It is suggested that this phenomenon may be responsible for numerous reports of amitosis in the genesis of muscle fibers. The histological development of new straps resulted from an orderly sequence of events. Included in these were polar extension, nuclear migration, rotation, and fixation. Following these events there was increased mitochondrial activity, myofibril formation, and cross-banding. Spontaneous contractions were seen throughout the entire course of differentiation in vitro but became more regular and stronger in the later stages.

scholarly journals Role of fibronectin in primary mesenchyme cell migration in the sea urchin.

1985 ◽  
Vol 101 (4) ◽  
pp. 1487-1491 ◽  
Author(s):  
H Katow ◽  
M Hayashi
Keyword(s):  
Cell Migration ◽  
Sea Urchin ◽  
Culture Media ◽  
Horse Serum ◽  
Time Lapse ◽  
Mesenchyme Cell ◽  
Mesenchyme Cells ◽  
Primary Mesenchyme Cells

We studied the effect of fibronectin (FN) on the behavior of primary mesenchyme cells isolated from sea urchin mesenchyme blastulae in vitro using a time-lapse technique. The migration of isolated primary mesenchyme cells reconstituted in seawater and horse serum is dependent on the presence or absence of exogenous FN in the culture media. The cells in FN, 4 and 40 micrograms/ml, show a high percentage of migration and migrate long distances, whereas a higher concentration of FN at 400 micrograms/ml tends to inhibit migration.

scholarly journals In vitro effects on cellular shaping, contratility, cytoskeletal organization and mitochondrial activity in HL1 cells after different sounds stimulation. A qualitative pilot study and a theoretical physical model

2020 ◽  
Author(s):  
Carlo Dal Lin ◽  
Claudia Maria Radu ◽  
Giuseppe Vitiello ◽  
Paola Romano ◽  
Albino Polcari ◽  
...  
Keyword(s):  
Physical Model ◽  
Spatial Organization ◽  
Time Lapse ◽  
Cell Types ◽  
Convincing Evidence ◽  
Cytoskeletal Proteins ◽  
Mitochondrial Activity ◽  
Sound Waves ◽  
Alpha Tubulin

AbstractConvincing evidence has documented that mechanical vibrations profoundly affect the behaviour of different cell types and even the functions of different organs. Pressure waves such as those of sound could affect cytoskeletal molecules with coherent changes in their spatial organization and are conveyed to cellular nucleus via mechanotransduction. HL1 cells were grown and exposed to different sounds. Subsequently, cells were stained for phalloidin, beta-actin, alpha-tubulin, alpha-actinin-1 and MitoTracker® mitochondrial probe. The cells were analyzed with time-lapse and immunofluorescence/confocal microscopy. In this paper, we describe that different sound stimuli seem to influence the growth or death of HL1 cells, resulting in a different mitochondrial localization and expression of cytoskeletal proteins. Since the cellular behaviour seems to correlate with the meaning of the sound used, we speculate that it can be “understood” by the cells by virtue of the different sound waves geometric properties that we have photographed and filmed. A theoretical physical model is proposed to explain our preliminary results.

scholarly journals Recapitulating early development of mouse musculoskeletal precursors of the paraxial mesoderm in vitro

2017 ◽  
Author(s):  
Jérome Chal ◽  
Ziad Al Tanoury ◽  
Masayuki Oginuma ◽  
Philippe Moncuquet ◽  
Bénédicte Gobert ◽  
...  
Keyword(s):  
Neural Tube ◽  
Es Cells ◽  
Horse Serum ◽  
Muscle Fibers ◽  
Embryonic Stem ◽  
Paraxial Mesoderm ◽  
Mouse Muscle ◽  
Efficient System

AbstractIn vertebrates, body skeletal muscles and axial skeleton derive from the paraxial mesoderm which flanks the neural tube and notochord. The paraxial mesoderm forms in the posterior region of the embryo as presomitic mesoderm (PSM), which generates the embryonic segments called somites. Here, we characterized gene signatures identified using microarray series from the mouse PSM and compared the PSM transcriptome dynamics to that of the developing neural tube. In contrast to the PSM where an abrupt transcriptome reorganisation occurs at the level of the determination front, we show that transcriptome changes are progressive during parallel stages of neural tube differentiation. We show that these early differentiation stages of the paraxial mesoderm can be efficiently recapitulated in monolayer culture in vitro using murine Embryonic Stem (ES) cells. We describe a serum-containing protocol which parallels in vivo tissue maturation allowing differentiation of ES cells towards a paraxial mesoderm fate. We show that R-spondin treatment or Wnt activation alone can induce posterior PSM markers in both mouse and human ES/iPS cells but acquisition of a committed posterior PSM fate requires BMP inhibition to prevent induced cells to drift to a lateral plate mesoderm identity. We show that posterior PSM-like cells induced from mouse ES cells can be further differentiated in vitro to acquire an anterior PSM Pax3-positive identity. When grafted into injured adult muscle, these induced PSM-like precursors generated large numbers of immature muscle fibers. We further show that exposing ES-derived PSM-like cells to a brief FGF inhibition step followed by culture in horse serum-containing medium allows efficient recapitulation of the myogenic program. Differentiating ES cells first produce mononucleated embryonic myocytes and subsequently multinucleated myotubes, as well as Pax7-positive cells. The protocol described here results in improved differentiation and maturation of mouse muscle fibers differentiated in vitro over serum-free protocols. It provides an efficient system for the study of myogenic processes otherwise difficult to study in vivo such as fusion or satellite cell differentiation.

Cytochemical localization of calcium in myoblasts of the chick embryo myotome

1995 ◽  
Vol 53 ◽  
pp. 1062-1063
Author(s):  
R. González Santander ◽  
M.V. Toledo Lobo ◽  
F.J. Martínez Alonso ◽  
G. Martínez Cuadrado ◽  
M. Gánzalez-Santander Martinez ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Muscle Development ◽  
Myoblast Fusion ◽  
Cytochemical Localization ◽  
Intracellular Ca ◽  
First Time ◽  
And Storage ◽  
Multinucleated Myotubes

Muscle fibers are derived from multinucleated myotubes which are themselves formed during embryonic development by the fusion of mononucleated myoblasts. Myoblast fusion results from a sequence of different and highly orchestrated stages demonstrated previously in vitro: recognitionalignment, adhesion and membrane fusion. Like many other fusion systems, myoblast fusion is Ca2+ - dependent. The role of Ca2+ is multiple since it is needed for muscle cell differentiation, for the alignment stage and it has also been demonstrated that Ca2+ influx precedes fusion increasing free intracellular Ca2+. It has been proposed that this increase in free intracellular Ca2+ may activate an enzimatic cascade which leads to membrane fusion.The present study, using the K-pyroantimonate method, describes Ca2+ localization and storage in myoblasts before fusion for the first time, since this method had not been applied to skeletal muscle development studies before. Chick embryos from 51 to 108 h. of incubation (Hamburger and Hamilton stages 16 to 25) were used.

scholarly journals Mannose receptor regulates myoblast motility and muscle growth

2006 ◽  
Vol 174 (3) ◽  
pp. 403-413 ◽  
Author(s):  
Katie M. Jansen ◽  
Grace K. Pavlath
Keyword(s):  
Skeletal Muscle ◽  
Transmembrane Protein ◽  
Muscle Growth ◽  
Mannose Receptor ◽  
Time Lapse ◽  
Myoblast Fusion ◽  
Type I ◽  
Matrix Remodeling

Myoblast fusion is critical for the formation, growth, and maintenance of skeletal muscle. The initial formation of nascent myotubes requires myoblast–myoblast fusion, but further growth involves myoblast–myotube fusion. We demonstrate that the mannose receptor (MR), a type I transmembrane protein, is required for myoblast–myotube fusion. Mannose receptor (MR)–null myotubes were small in size and contained a decreased myonuclear number both in vitro and in vivo. We hypothesized that this defect may arise from a possible role of MR in cell migration. Time-lapse microscopy revealed that MR-null myoblasts migrated with decreased velocity during myotube growth and were unable to migrate in a directed manner up a chemoattractant gradient. Furthermore, collagen uptake was impaired in MR-null myoblasts, suggesting a role in extracellular matrix remodeling during cell motility. These data identify a novel function for MR during skeletal muscle growth and suggest that myoblast motility may be a key aspect of regulating myotube growth.

scholarly journals WNT/β-Catenin Signaling Regulates Multiple Steps of Myogenesis by Regulating Step-Specific Targets

2015 ◽  
Vol 35 (10) ◽  
pp. 1763-1776 ◽  
Author(s):  
Akiko Suzuki ◽  
Richard C. Pelikan ◽  
Junichi Iwata
Keyword(s):  
Muscle Development ◽  
Myoblast Fusion ◽  
C2c12 Cells ◽  
Biological Processes ◽  
Proliferating Cells ◽  
Spatiotemporal Expression ◽  
Primary Mouse ◽  
Proliferation Activity ◽  
Well Differentiated

Molecules involved in WNT/β-catenin signaling show specific spatiotemporal expression and play vital roles in myogenesis; however, it is still largely unknown how WNT/β-catenin signaling regulates each step of myogenesis. Here, we show that WNT/β-catenin signaling can control diverse biological processes of myogenesis by regulating step-specific molecules. In order to identify the temporally specific roles of WNT/β-catenin signaling molecules in muscle development and homeostasis, we usedin vitroculture systems for both primary mouse myoblasts and C2C12 cells, which can differentiate into myofibers. We found that a blockade of WNT/β-catenin signaling in the proliferating cells decreases proliferation activity, but does not induce cell death, through the regulation of genes cyclin A2 (Ccna2) and cell division cycle 25C (Cdc25c). During muscle differentiation, the inhibition of WNT/β-catenin signaling blocks myoblast fusion through the inhibition of the Fermitin family homolog 2 (Fermt2) gene. Blocking WNT/β-catenin signaling in the well-differentiated myofibers results in the failure of maintenance of their structure by disruption of cadherin/β-catenin/actin complex formation, which plays a crucial role in connecting a myofiber's cytoskeleton to the surrounding extracellular matrix. Thus, our results indicate that WNT/β-catenin signaling can regulate multiple steps of myogenesis, including cell proliferation, myoblast fusion, and homeostasis, by targeting step-specific molecules.

scholarly journals NOTCH inhibition promotes myoblast fusion by releasing HEYL repression on TMEM8C regulatory regions in foetal skeletal muscles

2020 ◽  
Author(s):  
Joana Esteves de Lima ◽  
Cédrine Blavet ◽  
Marie-Ange Bonnin ◽  
Estelle Hirsinger ◽  
Emmanuelle Havis ◽  
...  
Keyword(s):  
Muscle Development ◽  
Close Association ◽  
Myoblast Fusion ◽  
Promoting Effect ◽  
Notch Signalling Pathway ◽  
Regulatory Regions ◽  
Central Regions ◽  
Notch Inhibition

AbstractDifferentiation and fusion are two intricate processes involved in skeletal muscle development. The close association of differentiation and fusion makes it difficult to address the process of fusion independently of differentiation. Using the fusion marker myomaker, named TMEM8C in chicken, we found that both TMEM8C transcripts and the differentiated and fusion-competent MYOG+ cells are preferentially regionalized in the central regions of limb foetal muscles in chicken embryos. Because the NOTCH signalling pathway is a potent inhibitor of muscle differentiation during developmental myogenesis, NOTCH function in myoblast fusion was not addressed so far. We analysed the consequences of NOTCH inhibition for myoblast fusion and TMEM8C expression during foetal myogenesis using in vitro and in vivo chicken systems. NOTCH inhibition following chicken embryo immobilisation or in myoblast cultures increased TMEM8C expression and myoblast fusion. Moreover, we showed that NOTCH inhibition induced the un-binding of the HEYL transcriptional repressor from the TMEM8C regulatory regions in limb muscles and myoblast cultures. These results identify a molecular mechanism underlying the fusion-promoting effect of NOTCH-inhibition during foetal myogenesis.

scholarly journals Dimerization partners determine the activity of the Twist bHLH protein during Drosophila mesoderm development

Development ◽  
2001 ◽  
Vol 128 (16) ◽  
pp. 3145-3159 ◽  
Author(s):  
Irinka Castanon ◽  
Stephen Von Stetina ◽  
Jason Kass ◽  
Mary K. Baylies
Keyword(s):  
Cell Fate ◽  
Muscle Development ◽  
Bhlh Protein ◽  
Mesoderm Induction ◽  
Loss Of Function ◽  
Somatic Muscle ◽  
Cell Fate Decisions ◽  
Sequence Of Events

The basic helix-loop-helix transcription factor Twist regulates a series of distinct cell fate decisions within the Drosophila mesodermal lineage. These twist functions are reflected in its dynamic pattern of expression, which is characterized by initial uniform expression during mesoderm induction, followed by modulated expression at high and low levels in each mesodermal segment, and finally restricted expression in adult muscle progenitors. We show two distinct partner-dependent functions for Twist that are crucial for cell fate choice. We find that Twist can form homodimers and heterodimers with the Drosophila E protein homologue, Daughterless,in vitro. Using tethered dimers to assess directly the function of these two particular dimers in vivo, we show that Twist homodimers specify mesoderm and the subsequent allocation of mesodermal cells to the somatic muscle fate. Misexpression of Twist-tethered homodimers in the ectoderm or mesoderm leads to ectopic somatic muscle formation overriding other developmental cell fates. In addition, expression of tethered Twist homodimers in embryos null fortwist can rescue mesoderm induction as well as somatic muscle development. Loss of function analyses, misexpression and dosage experiments, and biochemical studies indicate that heterodimers of Twist and Daughterless repress genes required for somatic myogenesis. We propose that these two opposing roles explain how modulated Twist levels promote the allocation of cells to the somatic muscle fate during the subdivision of the mesoderm. Moreover, this work provides a paradigm for understanding how the same protein controls a sequence of events within a single lineage.

scholarly journals Filopodia powered by class X myosin promote fusion of mammalian myoblasts

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
David W Hammers ◽  
Cora C Hart ◽  
Michael K Matheny ◽  
Ernest G Heimsath ◽  
Young il Lee ◽  
...  
Keyword(s):  
Fusion Proteins ◽  
Muscle Injury ◽  
Muscle Fibers ◽  
Myoblast Fusion ◽  
Mammalian Muscle ◽  
Muscle Formation ◽  
Resident Stem Cells

Skeletal muscle fibers are multinucleated cellular giants formed by the fusion of mononuclear myoblasts. Several molecules involved in myoblast fusion have been discovered, and finger-like projections coincident with myoblast fusion have also been implicated in the fusion process. The role of these cellular projections in muscle cell fusion was investigated herein. We demonstrate that these projections are filopodia generated by class X myosin (Myo10), an unconventional myosin motor protein specialized for filopodia. We further show that Myo10 is highly expressed by differentiating myoblasts, and Myo10 ablation inhibits both filopodia formation and myoblast fusion in vitro. In vivo, Myo10 labels regenerating muscle fibers associated with Duchenne muscular dystrophy and acute muscle injury. In mice, conditional loss of Myo10 from muscle-resident stem cells, known as satellite cells, severely impairs postnatal muscle regeneration. Furthermore, the muscle fusion proteins Myomaker and Myomixer are detected in myoblast filopodia. These data demonstrate that Myo10-driven filopodia facilitate multi-nucleated mammalian muscle formation.

Sign in / Sign up

Export Citation Format

Share Document