Expression of sialic acids in human adult skeletal muscle tissue

AbstractAdult tissue repair and regeneration require the activation of resident stem/progenitor cells that can self-renew and generate differentiated progeny. The regenerative capacity of skeletal muscle relies on muscle satellite cells (MuSCs) and their interplay with different cell types within the niche. Yet, our understanding of the cells that compose the skeletal muscle tissue is limited and molecular definitions of the principal cell types are lacking. Using a combined approach of single-cell RNA-sequencing and mass cytometry, we precisely mapped the different cell types in adult skeletal muscle tissue and highlighted previously overlooked populations. We identified known functional populations, characterized their gene signatures, and determined key markers. Among the ten main cell populations present in skeletal muscle, we found an unexpected complexity in the interstitial compartment and identified two new cell populations. One express the transcription factor Scleraxis and generate tenocyte-like cells. The second express smooth muscle and mesenchymal cell markers (SMMCs). While distinct from MuSCs, SMMCs are endowed with myogenic potential and promote MuSC engraftment following transplantation. Our high-dimensional single-cell atlas uncovers principles of an adult tissue composition and can be exploited to reveal unknown cellular sub-fractions that contribute to tissue regeneration.

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Rbfox splicing factors maintain skeletal muscle mass by regulating calpain3 and proteostasis

10.1101/257261 ◽

2018 ◽

Author(s):

Ravi K. Singh ◽

Arseniy M. Kolonin ◽

Marta L. Fiorotto ◽

Thomas A. Cooper

Keyword(s):

Skeletal Muscle ◽

Protein Synthesis ◽

Alternative Splicing ◽

Muscle Mass ◽

Muscle Tissue ◽

Active Form ◽

Skeletal Muscle Tissue ◽

List Type ◽

Autophagy Flux ◽

Adult Skeletal Muscle

ABSTRACTAlternative splicing promotes proteomic diversity important for cellular differentiation and cell fate determination. Here, we show that deletion of the highly conserved Rbfox1 and Rbfox2 alternative splicing regulators in adult mouse skeletal muscle causes rapid, severe loss of muscle mass. Homeostasis of skeletal muscle tissue requires a dynamic balance between protein synthesis and degradation (proteostasis) but the mechanisms that regulate this balance are not well understood. Rbfox deletion did not cause reduced global protein synthesis, but resulted in reduced autophagy flux and altered splicing of hundreds of transcripts including Capn3, which produced an active form of calpain3 protease. The results indicate Rbfox proteins regulate proteostasis in skeletal muscle tissue by control of calpain and autophagy-lysosome pathways.HighlightsProteostasis in adult skeletal muscle is post-transcriptionally regulated, in part by alternative splicing via Rbfox1/2Rbfox1/2 regulate hundreds of targets in skeletal muscle, including Calpn3, to maintain muscle mass in adult miceAutophagy flux is markedly decreased in muscle lacking Rbfox1/2As for neurons, altered proteostasis is detrimental to adult muscle

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Muscle stem cell intramuscular delivery within hyaluronan methylcellulose improves engraftment efficiency and dispersion

10.1101/245258 ◽

2018 ◽

Author(s):

Sadegh Davoudi ◽

Chih-Ying Chin ◽

Michael C. Cooke ◽

Roger Y. Tam ◽

Molly S. Shoichet ◽

...

Keyword(s):

Skeletal Muscle ◽

Delivery System ◽

Muscle Tissue ◽

Donor Cell ◽

Cell Loss ◽

Skeletal Muscle Tissue ◽

Adult Skeletal Muscle ◽

Cell Clearance ◽

Pass Through

AbstractAdult skeletal muscle tissue harbors the capacity for self-repair due to the presence of tissue resident muscle stem cells (MuSCs). Advances in the area of prospective MuSC isolation demonstrated the potential of cell transplantation therapy as a regenerative medicine strategy to restore strength and long-term regenerative capacity to aged, injured, or diseased skeletal muscle tissue. However, cell loss during ejection, limits to post-injection proliferation, and poor donor cell dispersion distal to the injection site are amongst hurdles to overcome to maximize MuSC transplant impact. Here, we assess a physical blend of hyaluronan and methylcellulose (HAMC) as a bioactive, shear thinning hydrogel cell delivery system to improve MuSC transplantation efficiency. Using in vivo transplantation studies, we found that the HAMC delivery system results in a >45% increase in the number of donor-derived fibers as compared to saline delivery. Furthermore, we observed a significant improvement in donor fiber dispersion when transplanted MuSCs were delivered in the HAMC hydrogel. Studies to assess primary myoblast and MuSC viability in HAMC culture revealed no differences compared to the media control even when the cells were first ejected through a syringe and needle or exposed to regenerating skeletal muscle extract to mimic the transplantation procedure. However, when we quantified absolute numbers, we found that more cells pass through the syringe and needle when delivered in HAMC. Culture in HAMC also increased the proportion of MuSCs in cell cycle, via a CD44-independent mechanism. An effect on myoblast proliferation was not observed, suggesting a hierarchical effect. Finally, a series of transplant studies indicated that HAMC delivery does not influence passive cell clearance or alter the host immune response, but instead may serve to support in vivo expansion by delaying differentiation following transplant. Therefore, we conclude that MuSC engraftment efficacy is improved by delivering the therapeutic cell population within HAMC.

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Bone marrow derived cells in adult skeletal muscle tissue in humans

Skeletal Muscle ◽

10.1186/2044-5040-3-12 ◽

2013 ◽

Vol 3 (1) ◽

pp. 12 ◽

Cited By ~ 12

Author(s):

Anna Strömberg ◽

Monika Jansson ◽

Helene Fischer ◽

Eric Rullman ◽

Hans Hägglund ◽

...

Keyword(s):

Skeletal Muscle ◽

Bone Marrow ◽

Muscle Tissue ◽

Skeletal Muscle Tissue ◽

Adult Skeletal Muscle ◽

Bone Marrow Derived Cells

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Recycled algae-based carbon materials as electroconductive 3D printed skeletal muscle tissue engineering scaffolds

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-021-06534-6 ◽

2021 ◽

Vol 32 (7) ◽

Author(s):

Selva Bilge ◽

Emre Ergene ◽

Ebru Talak ◽

Seyda Gokyer ◽

Yusuf Osman Donar ◽

...

Keyword(s):

Skeletal Muscle ◽

Tissue Engineering ◽

Electrical Stimulation ◽

Muscle Tissue ◽

Carbonaceous Material ◽

Hydrothermal Carbonization ◽

Skeletal Muscle Tissue ◽

Myotube Formation ◽

3D Printed

AbstractSkeletal muscle is an electrically and mechanically active tissue that contains highly oriented, densely packed myofibrils. The tissue has self-regeneration capacity upon injury, which is limited in the cases of volumetric muscle loss. Several regenerative therapies have been developed in order to enhance this capacity, as well as to structurally and mechanically support the defect site during regeneration. Among them, biomimetic approaches that recapitulate the native microenvironment of the tissue in terms of parallel-aligned structure and biophysical signals were shown to be effective. In this study, we have developed 3D printed aligned and electrically active scaffolds in which the electrical conductivity was provided by carbonaceous material (CM) derived from algae-based biomass. The synthesis of this conductive and functional CM consisted of eco-friendly synthesis procedure such as pre-carbonization and multi-walled carbon nanotube (MWCNT) catalysis. CM obtained from biomass via hydrothermal carbonization (CM-03) and its ash form (CM-03K) were doped within poly(ɛ-caprolactone) (PCL) matrix and 3D printed to form scaffolds with aligned fibers for structural biomimicry. Scaffolds were seeded with C2C12 mouse myoblasts and subjected to electrical stimulation during the in vitro culture. Enhanced myotube formation was observed in electroactive groups compared to their non-conductive counterparts and it was observed that myotube formation and myotube maturity were significantly increased for CM-03 group after electrical stimulation. The results have therefore showed that the CM obtained from macroalgae biomass is a promising novel source for the production of the electrically conductive scaffolds for skeletal muscle tissue engineering.

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