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Medicine and Science in Sports and... Oct 2019Instrument-assisted soft tissue mobilization (IASTM) has been reported to improve joint range of motion (flexibility). However, it is not clear whether this change in... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Instrument-assisted soft tissue mobilization (IASTM) has been reported to improve joint range of motion (flexibility). However, it is not clear whether this change in the joint range of motion is accompanied by any alterations in the mechanical and/or neural properties. This study aimed to investigate the effects of IASTM in plantarflexors and Achilles tendon on the mechanical and neural properties of them.
METHODS
This randomized, controlled, crossover study included 14 healthy volunteers (11 men and 3 women, 21-32 yr). IASTM was performed on the skin over the posterior part of the lower leg for 5 min and targeted the soft tissues (gastrocnemii, soleus, and tibialis posterior muscles; overlying deep fascia; and Achilles tendon). As a control condition, the same participants rested for 5 min between pre- and postmeasurements without IASTM on a separate day. The maximal ankle joint dorsiflexion angle (dorsiflexion range of motion), the peak passive torque (stretch tolerance), and the ankle joint stiffness (slope of the relationship between passive torque and ankle joint angle) during the measurement of the dorsiflexion range of motion and muscle stiffness of the triceps surae (using shear wave elastography) were measured before and immediately after the interventions.
RESULTS
After IASTM, the dorsiflexion range of motion significantly increased by 10.7% ± 10.8% and ankle joint stiffness significantly decreased by -6.2% ± 10.1%. However, peak passive torque and muscle stiffness did not change. All variables remained unchanged in the repeated measurements of controls.
CONCLUSION
IASTM can improve joint range of motion, without affecting the mechanical and neural properties of the treated muscles.
Topics: Achilles Tendon; Adult; Ankle Joint; Biomechanical Phenomena; Cross-Over Studies; Elasticity Imaging Techniques; Electromyography; Female; Humans; Male; Muscle, Skeletal; Range of Motion, Articular; Therapy, Soft Tissue; Young Adult
PubMed: 31083046
DOI: 10.1249/MSS.0000000000002035 -
International Journal of Molecular... Feb 2023The "motor unit" or the "muscle" has long been considered the quantal element in the control of movement. However, in recent years new research has proved the strong... (Review)
Review
The "motor unit" or the "muscle" has long been considered the quantal element in the control of movement. However, in recent years new research has proved the strong interaction between muscle fibers and intramuscular connective tissue, and between muscles and fasciae, suggesting that the muscles can no longer be considered the only elements that organize movement. In addition, innervation and vascularization of muscle is strongly connected with intramuscular connective tissue. This awareness induced Luigi Stecco, in 2002, to create a new term, the "myofascial unit", to describe the bilateral dependent relationship, both anatomical and functional, that occurs between fascia, muscle and accessory elements. The aim of this narrative review is to understand the scientific support for this new term, and whether it is actually correct to consider the myofascial unit the physiological basic element for peripheral motor control.
Topics: Muscle, Skeletal; Fascia; Connective Tissue; Muscle Fibers, Skeletal; Muscle Contraction
PubMed: 36901958
DOI: 10.3390/ijms24054527 -
Nutrients Jan 2021Exercise-induced muscle damage (EIMD) is characterized by histopathological muscle tissue changes that originate skeletal muscle damage [...].
Exercise-induced muscle damage (EIMD) is characterized by histopathological muscle tissue changes that originate skeletal muscle damage [...].
Topics: Athletes; Athletic Performance; Diet; Dietary Supplements; Exercise; Humans; Muscle, Skeletal
PubMed: 33498579
DOI: 10.3390/nu13020294 -
American Journal of Physiology. Cell... Mar 2020Rat L6, mouse C2C12, and primary human skeletal muscle cells (HSMCs) are commonly used to study biological processes in skeletal muscle, and experimental data on these... (Comparative Study)
Comparative Study
Rat L6, mouse C2C12, and primary human skeletal muscle cells (HSMCs) are commonly used to study biological processes in skeletal muscle, and experimental data on these models are abundant. However, consistently matched experimental data are scarce, and comparisons between the different cell types and adult tissue are problematic. We hypothesized that metabolic differences between these cellular models may be reflected at the mRNA level. Publicly available data sets were used to profile mRNA levels in myotubes and skeletal muscle tissues. L6, C2C12, and HSMC myotubes were assessed for proliferation, glucose uptake, glycogen synthesis, mitochondrial activity, and substrate oxidation, as well as the response to in vitro contraction. Transcriptomic profiling revealed that mRNA of genes coding for actin and myosin was enriched in C2C12, whereas L6 myotubes had the highest levels of genes encoding glucose transporters and the five complexes of the mitochondrial electron transport chain. Consistently, insulin-stimulated glucose uptake and oxidative capacity were greatest in L6 myotubes. Insulin-induced glycogen synthesis was highest in HSMCs, but C2C12 myotubes had higher baseline glucose oxidation. All models responded to electrical pulse stimulation-induced glucose uptake and gene expression but in a slightly different manner. Our analysis reveals a great degree of heterogeneity in the transcriptomic and metabolic profiles of L6, C2C12, or primary human myotubes. Based on these distinct signatures, we provide recommendations for the appropriate use of these models depending on scientific hypotheses and biological relevance.
Topics: Adult; Animals; Cell Line; Cell Proliferation; Cells, Cultured; Energy Metabolism; Gene Expression Profiling; Humans; Male; Mice; Middle Aged; Muscle Cells; Muscle Fibers, Skeletal; Muscle, Skeletal; Rats; Species Specificity; Transcriptome
PubMed: 31825657
DOI: 10.1152/ajpcell.00540.2019 -
The FEBS Journal Nov 2022The characterization of fibro/adipogenic progenitor cells (FAPs) in the skeletal muscle has contributed to modify the monocentric view of muscle regeneration beyond... (Review)
Review
The characterization of fibro/adipogenic progenitor cells (FAPs) in the skeletal muscle has contributed to modify the monocentric view of muscle regeneration beyond muscle satellite cells (MuSCs). Now, we are aware that each population of the muscle niche plays a critical role in modulating homeostasis and regeneration. In the healthy muscle, FAPs contribute to maintain tissue homeostasis and assist MuSCs to cope with limited insults. Here, FAPs sense and integrate niche signals that keep in check their differentiation potential. The disruption of these niche cues leads to FAP differentiation into adipocytes and fibroblasts, both detrimental hallmarks of a large variety of muscle wasting diseases. FAP biology is still in its infancy, and current efforts are focused on the understanding of the molecular circuits governing their double-edged behavior. The present review offers a detailed overview of the pathways and metabolic routes that can be modulated to halt and redirect their fibro/adipogenic potential while favoring their supportive role in muscle regeneration. Finally, we discuss on how single-cell technologies have contributed to resolve FAP transitional states with distinctive roles in muscle regeneration and myopathies.
Topics: Adipogenesis; Adipocytes; Cell Differentiation; Signal Transduction; Muscle, Skeletal; Regeneration
PubMed: 34143565
DOI: 10.1111/febs.16080 -
Scientific Reports Jan 2020Skeletal muscle is a heterogeneous tissue comprised of muscle fiber and mononuclear cell types that, in addition to movement, influences immunity, metabolism and...
Skeletal muscle is a heterogeneous tissue comprised of muscle fiber and mononuclear cell types that, in addition to movement, influences immunity, metabolism and cognition. We investigated the gene expression patterns of skeletal muscle cells using RNA-seq of subtype-pooled single human muscle fibers and single cell RNA-seq of mononuclear cells from human vastus lateralis, mouse quadriceps, and mouse diaphragm. We identified 11 human skeletal muscle mononuclear cell types, including two fibro-adipogenic progenitor (FAP) cell subtypes. The human FBN1+ FAP cell subtype is novel and a corresponding FBN1+ FAP cell type was also found in single cell RNA-seq analysis in mouse. Transcriptome exercise studies using bulk tissue analysis do not resolve changes in individual cell-type proportion or gene expression. The cell-type gene signatures provide the means to use computational methods to identify cell-type level changes in bulk studies. As an example, we analyzed public transcriptome data from an exercise training study and revealed significant changes in specific mononuclear cell-type proportions related to age, sex, acute exercise and training. Our single-cell expression map of skeletal muscle cell types will further the understanding of the diverse effects of exercise and the pathophysiology of muscle disease.
Topics: Adipogenesis; Animals; Biomarkers; Diaphragm; Female; Humans; Male; Mice; Muscle, Skeletal; Quadriceps Muscle; Single-Cell Analysis; Transcriptome
PubMed: 31937892
DOI: 10.1038/s41598-019-57110-6 -
Biochimica Et Biophysica Acta.... Sep 2020Skeletal muscle is a dynamic tissue with two unique abilities; one is its excellent regenerative ability, due to the activity of skeletal muscle-resident stem cells... (Review)
Review
Skeletal muscle is a dynamic tissue with two unique abilities; one is its excellent regenerative ability, due to the activity of skeletal muscle-resident stem cells named muscle satellite cells (MuSCs); and the other is the adaptation of myofiber size in response to external stimulation, intrinsic factors, or physical activity, which is known as plasticity. Low physical activity and some disease conditions lead to the reduction of myofiber size, called atrophy, whereas hypertrophy refers to the increase in myofiber size induced by high physical activity or anabolic hormones/drugs. MuSCs are essential for generating new myofibers during regeneration and the increase in new myonuclei during hypertrophy; however, there has been little investigation of the molecular mechanisms underlying MuSC activation, proliferation, and differentiation during hypertrophy compared to those of regeneration. One reason is that 'degenerative damage' to myofibers during muscle injury or upon hypertrophy (especially overloaded muscle) is believed to trigger similar activation/proliferation of MuSCs. However, evidence suggests that degenerative damage of myofibers is not necessary for MuSC activation/proliferation during hypertrophy. When considering MuSC-based therapy for atrophy, including sarcopenia, it will be indispensable to elucidate MuSC behaviors in muscles that exhibit non-degenerative damage, because degenerated myofibers are not present in the atrophied muscles. In this review, we summarize recent findings concerning the relationship between MuSCs and hypertrophy, and discuss what remains to be discovered to inform the development and application of relevant treatments for muscle atrophy.
Topics: Animals; Biomarkers; Cell Proliferation; Humans; Hypertrophy; Muscle, Skeletal; Regeneration; Satellite Cells, Skeletal Muscle
PubMed: 32417255
DOI: 10.1016/j.bbamcr.2020.118742 -
International Journal of Molecular... Dec 2020There has been an escalation in reports over the last decade examining the efficacy of bone marrow derived mesenchymal stem/stromal cells (BMSC) in bone tissue... (Review)
Review
There has been an escalation in reports over the last decade examining the efficacy of bone marrow derived mesenchymal stem/stromal cells (BMSC) in bone tissue engineering and regenerative medicine-based applications. The multipotent differentiation potential, myelosupportive capacity, anti-inflammatory and immune-modulatory properties of BMSC underpins their versatile nature as therapeutic agents. This review addresses the current limitations and challenges of exogenous autologous and allogeneic BMSC based regenerative skeletal therapies in combination with bioactive molecules, cellular derivatives, genetic manipulation, biocompatible hydrogels, solid and composite scaffolds. The review highlights the current approaches and recent developments in utilizing endogenous BMSC activation or exogenous BMSC for the repair of long bone and vertebrae fractures due to osteoporosis or trauma. Current advances employing BMSC based therapies for bone regeneration of craniofacial defects is also discussed. Moreover, this review discusses the latest developments utilizing BMSC therapies in the preclinical and clinical settings, including the treatment of bone related diseases such as Osteogenesis Imperfecta.
Topics: Animals; Humans; Mesenchymal Stem Cells; Muscle, Skeletal; Regeneration; Tissue Engineering
PubMed: 33371306
DOI: 10.3390/ijms21249759 -
International Journal of Molecular... May 2022In vitro organoids derived from human pluripotent stem cells (hPSCs) have been developed as essential tools to study the underlying mechanisms of human development and...
In vitro organoids derived from human pluripotent stem cells (hPSCs) have been developed as essential tools to study the underlying mechanisms of human development and diseases owing to their structural and physiological similarity to corresponding organs. Despite recent advances, there are a few methodologies for three-dimensional (3D) skeletal muscle differentiation, which focus on the terminal differentiation into myofibers and investigate the potential of modeling neuromuscular disorders and muscular dystrophies. However, these methodologies cannot recapitulate the developmental processes and lack regenerative capacity. In this study, we developed a new method to differentiate hPSCs into a 3D human skeletal muscle organoid (hSkMO). This organoid model could recapitulate the myogenesis process and possesses regenerative capacities of sustainable satellite cells (SCs), which are adult muscle stem/progenitor cells capable of self-renewal and myogenic differentiation. Our 3D model demonstrated myogenesis through the sequential occurrence of multiple myogenic cell types from SCs to myocytes. Notably, we detected quiescent, non-dividing SCs throughout the hSkMO differentiation in long-term culture. They were activated and differentiated to reconstitute muscle tissue upon damage. Thus, hSkMOs can recapitulate human skeletal muscle development and regeneration and may provide a new model for studying human skeletal muscles and related diseases.
Topics: Cell Differentiation; Humans; Muscle Development; Muscle, Skeletal; Organoids; Pluripotent Stem Cells
PubMed: 35563499
DOI: 10.3390/ijms23095108 -
Cell Stem Cell Dec 2019Many adult tissues contain resident stem cells, such as the Pax7 satellite cells within skeletal muscle, that regenerate parenchymal elements following damage....
Many adult tissues contain resident stem cells, such as the Pax7 satellite cells within skeletal muscle, that regenerate parenchymal elements following damage. Tissue-resident mesenchymal progenitors (MPs) also participate in regeneration, although their function and fate in this process are unclear. Here, we identify Hypermethylated in cancer 1 (Hic1) as a marker of MPs in skeletal muscle and further show that Hic1 deletion leads to MP hyperplasia. Single-cell RNA-seq and ATAC-seq analysis of Hic1 MPs in skeletal muscle shows multiple subpopulations, which we further show have distinct functions and lineage potential. Hic1 MPs orchestrate multiple aspects of skeletal muscle regeneration by providing stage-specific immunomodulation and trophic and mechanical support. During muscle regeneration, Hic1 derivatives directly contribute to several mesenchymal compartments including Col22a1-expressing cells within the myotendinous junction. Collectively, these findings demonstrate that HIC1 regulates MP quiescence and identifies MP subpopulations with transient and enduring roles in muscle regeneration.
Topics: Animals; Cell Cycle; Cell Differentiation; Cell Proliferation; Cells, Cultured; Female; Fluorescent Antibody Technique; Kruppel-Like Transcription Factors; Male; Mice; Muscle, Skeletal; Regeneration; Satellite Cells, Skeletal Muscle; Wound Healing
PubMed: 31809738
DOI: 10.1016/j.stem.2019.11.004