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Annual Review of Physiology Feb 2023Myostatin (GDF-8) was discovered 25 years ago as a new transforming growth factor-β family member that acts as a master regulator of skeletal muscle mass. Myostatin is... (Review)
Review
Myostatin (GDF-8) was discovered 25 years ago as a new transforming growth factor-β family member that acts as a master regulator of skeletal muscle mass. Myostatin is made by skeletal myofibers, circulates in the blood, and acts back on myofibers to limit growth. Myostatin appears to have all of the salient properties of a chalone, which is a term proposed over a half century ago to describe hypothetical circulating, tissue-specific growth inhibitors that control tissue size. The elucidation of the molecular, cellular, and physiological mechanisms underlying myostatin activity suggests that myostatin functions as a negative feedback regulator of muscle mass and raises the question as to whether this type of chalone mechanism is unique to skeletal muscle or whether it also operates in other tissues.
Topics: Humans; Myostatin; Chalones; Muscle, Skeletal; Transforming Growth Factor beta
PubMed: 36266260
DOI: 10.1146/annurev-physiol-012422-112116 -
The Journal of Histochemistry and... Nov 2020Small leucine rich proteoglycans (SLRPs), including Biglycan, have key roles in many organ and tissue systems. The goal of this article is to review the function of... (Review)
Review
Small leucine rich proteoglycans (SLRPs), including Biglycan, have key roles in many organ and tissue systems. The goal of this article is to review the function of Biglycan and other related SLRPs in mineralizing tissues of the skeleton. The review is divided into sections that include Biglycan's role in structural biology, signaling, craniofacial and long bone homeostasis, remodeled skeletal tissues, and in human genetics. While many cell types in the skeleton are now known to be affected by Biglycan, there are still unanswered questions about its mechanism of action(s).
Topics: Animals; Biglycan; Humans; Muscle, Skeletal
PubMed: 32623936
DOI: 10.1369/0022155420937371 -
International Journal of Molecular... Sep 2021Primary cilia are non-motile, cell cycle-associated organelles that can be found on most vertebrate cell types. Comprised of microtubule bundles organised into an... (Review)
Review
Primary cilia are non-motile, cell cycle-associated organelles that can be found on most vertebrate cell types. Comprised of microtubule bundles organised into an axoneme and anchored by a mature centriole or basal body, primary cilia are dynamic signalling platforms that are intimately involved in cellular responses to their extracellular milieu. Defects in ciliogenesis or dysfunction in cilia signalling underlie a host of developmental disorders collectively referred to as ciliopathies, reinforcing important roles for cilia in human health. Whilst primary cilia have long been recognised to be present in striated muscle, their role in muscle is not well understood. However, recent studies indicate important contributions, particularly in skeletal muscle, that have to date remained underappreciated. Here, we explore recent revelations that the sensory and signalling functions of cilia on muscle progenitors regulate cell cycle progression, trigger differentiation and maintain a commitment to myogenesis. Cilia disassembly is initiated during myoblast fusion. However, the remnants of primary cilia persist in multi-nucleated myotubes, and we discuss their potential role in late-stage differentiation and myofiber formation. Reciprocal interactions between cilia and the extracellular matrix (ECM) microenvironment described for other tissues may also inform on parallel interactions in skeletal muscle. We also discuss emerging evidence that cilia on fibroblasts/fibro-adipogenic progenitors and myofibroblasts may influence cell fate in both a cell autonomous and non-autonomous manner with critical consequences for skeletal muscle ageing and repair in response to injury and disease. This review addresses the enigmatic but emerging role of primary cilia in satellite cells in myoblasts and myofibers during myogenesis, as well as the wider tissue microenvironment required for skeletal muscle formation and homeostasis.
Topics: Animals; Axoneme; Cell Cycle; Cell Differentiation; Centrosome; Cilia; Cytoskeleton; Extracellular Matrix; Humans; Muscle Development; Muscle Fibers, Skeletal; Muscle, Skeletal; Myoblasts; Organelles; Signal Transduction
PubMed: 34502512
DOI: 10.3390/ijms22179605 -
Tissue Engineering and Regenerative... Apr 2022Skeletal muscle has an innate regenerative capacity to restore their structure and function following acute damages and injuries. However, in congenital muscular... (Review)
Review
Skeletal muscle has an innate regenerative capacity to restore their structure and function following acute damages and injuries. However, in congenital muscular dystrophies, large volumetric muscle loss, cachexia, or aging, the declined regenerative capacity of skeletal muscle results in muscle wasting and functional impairment. Recent studies indicate that muscle mass and function are closely correlated with morbidity and mortality due to the large volume and location of skeletal muscle. However, the options for treating neuromuscular disorders are limited. Biomedical engineering strategies such as nanotechnologies have been implemented to address this issue.In this review, we focus on recent studies leveraging nano-sized materials for regeneration of skeletal muscle. We look at skeletal muscle pathologies and describe various proof-of-concept and pre-clinical studies that have used nanomaterials, with a focus on how nano-sized materials can be used for skeletal muscle regeneration depending on material dimensionality.Depending on the dimensionality of nano-sized materials, their application have been changed because of their different physical and biochemical properties.Nanomaterials have been spotlighted as a great candidate for addressing the unmet needs of regenerative medicine. Nanomaterials could be applied to several types of tissues and diseases along with the unique characteristics of nanomaterials. However, when confined to muscle tissue, the targets of nanomaterial applications are limited and can be extended in future research.
Topics: Muscle, Skeletal; Nanostructures; Regeneration; Regenerative Medicine; Wound Healing
PubMed: 35334091
DOI: 10.1007/s13770-022-00446-4 -
The FEBS Journal Nov 2022Skeletal muscle is a structurally and functionally remarkable tissue composed of multinucleated post-mitotic muscle fibres. These fibres are filled with an exquisite,...
Skeletal muscle is a structurally and functionally remarkable tissue composed of multinucleated post-mitotic muscle fibres. These fibres are filled with an exquisite, near crystalline array of assembled contractile proteins, capable of coupling ATP utilization to mechanical muscle contraction. Fully differentiated muscle has an incredible ability to protect and repair itself from significant muscle injuries. In fact, through activation of a resident population of stem cells known as satellite cells, muscle fibres can be completely regenerated, and normal function can be restored in a matter of a few weeks after a major myocellular necrotic injury. The loss of key mechanisms to protect muscle from injuries or loss of the capacity to repair muscle after injury is thought to underlie several forms of muscular dystrophy and also the age-related decline of muscle function. In this Subject Collection, The FEBS Journal highlights articles that review or investigate key mechanisms of muscle repair and regeneration in response to injuries, and the contributions of these pathways to health and disease of skeletal muscle.
Topics: Humans; Satellite Cells, Skeletal Muscle; Muscle, Skeletal; Regeneration; Muscle Fibers, Skeletal; Muscular Diseases
PubMed: 35929418
DOI: 10.1111/febs.16577 -
Cells Nov 2021Efferocytosis, i.e., engulfment of dead cells by macrophages, is a crucial step during tissue repair after an injury. Efferocytosis delineates the transition from the... (Review)
Review
Efferocytosis, i.e., engulfment of dead cells by macrophages, is a crucial step during tissue repair after an injury. Efferocytosis delineates the transition from the pro-inflammatory phase of the inflammatory response to the recovery phase that ensures tissue reconstruction. We present here the role of efferocytosis during skeletal muscle regeneration, which is a paradigm of sterile tissue injury followed by a complete regeneration. We present the molecular mechanisms that have been described to control this process, and particularly the metabolic control of efferocytosis during skeletal muscle regeneration.
Topics: Apoptosis; Humans; Inflammation; Macrophages; Muscle, Skeletal; Phagocytosis; Regeneration; Wound Healing
PubMed: 34943775
DOI: 10.3390/cells10123267 -
Annual Review of Physiology Feb 2021Sestrins are a family of proteins that respond to a variety of environmental stresses, including genotoxic, oxidative, and nutritional stresses. Sestrins affect multiple... (Review)
Review
Sestrins are a family of proteins that respond to a variety of environmental stresses, including genotoxic, oxidative, and nutritional stresses. Sestrins affect multiple signaling pathways: AMP-activated protein kinase, mammalian target of rapamycin complexes, insulin-AKT, and redox signaling pathways. By regulating these pathways, Sestrins are thought to help adapt to stressful environments and subsequently restore cell and tissue homeostasis. In this review, we describe how Sestrins mediate physiological stress responses in the context of nutritional and chemical stresses (liver), physical movement and exercise (skeletal muscle), and chemical, physical, and inflammatory injuries (heart). These findings also support the idea that Sestrins are a molecular mediator of hormesis, a paradoxical beneficial effect of low- or moderate-level stresses in living organisms.
Topics: Animals; Exercise; Homeostasis; Humans; Muscle, Skeletal; Sestrins; Signal Transduction; Stress, Physiological
PubMed: 33113341
DOI: 10.1146/annurev-physiol-031620-092317 -
Advanced Healthcare Materials Jan 2020Volumetric muscle loss (VML) is a devastating loss of muscle tissue that overwhelms the native regenerative properties of skeletal muscle and results in lifelong... (Review)
Review
Volumetric muscle loss (VML) is a devastating loss of muscle tissue that overwhelms the native regenerative properties of skeletal muscle and results in lifelong functional deficits. There are currently no treatments for VML that fully recover the lost muscle tissue and function. Tissue engineering presents a promising solution for VML treatment and significant research has been performed using tissue engineered muscle constructs in preclinical models of VML with a broad range of defect locations and sizes, tissue engineered construct characteristics, and outcome measures. Due to the complex vascular and neural anatomy within skeletal muscle, regeneration of functional vasculature and nerves is vital for muscle recovery following VML injuries. This review aims to summarize the current state of the field of skeletal muscle tissue engineering using 3D constructs for VML treatment with a focus on studies that have promoted vascular and neural regeneration within the muscle tissue post-VML.
Topics: Animals; Blood Vessels; Humans; Hydrogels; Muscle, Skeletal; Muscular Diseases; Regeneration; Stem Cells; Tissue Engineering; Tissue Scaffolds
PubMed: 31622051
DOI: 10.1002/adhm.201900626 -
Cells Aug 2019Circular RNA (circRNA) is a novel class of non-coding RNA generated by pre-mRNA back splicing, which is characterized by a closed-loop structure. Although circRNAs were... (Review)
Review
Circular RNA (circRNA) is a novel class of non-coding RNA generated by pre-mRNA back splicing, which is characterized by a closed-loop structure. Although circRNAs were firstly reported decades ago, their regulatory roles have not been discovered until recently. In this review, we discussed the putative biogenesis pathways and regulatory functions of circRNAs. Recent studies showed that circRNAs are abundant in skeletal muscle tissue, and their expression levels are regulated during muscle development and aging. We, thus, characterized the expression profile of circRNAs in skeletal muscle and discussed regulatory functions and mechanism-of-action of specific circRNAs in myogenesis. The future investigation into the roles of circRNAs in both physiological and pathological conditions may provide novel insights in skeletal muscle development and provide new therapeutic strategies for muscular diseases.
Topics: Animals; Gene Expression Regulation, Developmental; Humans; Muscle Development; Muscle, Skeletal; RNA, Circular
PubMed: 31412632
DOI: 10.3390/cells8080885 -
Advanced Materials (Deerfield Beach,... Mar 2022Skeletal muscles play important roles in critical body functions and their injury or disease can lead to limitation of mobility and loss of independence. Current... (Review)
Review
Skeletal muscles play important roles in critical body functions and their injury or disease can lead to limitation of mobility and loss of independence. Current treatments result in variable functional recovery, while reconstructive surgery, as the gold-standard approach, is limited due to donor shortage, donor-site morbidity, and limited functional recovery. Skeletal muscle tissue engineering (SMTE) has generated enthusiasm as an alternative solution for treatment of injured tissue and serves as a functional disease model. Recently, bioprinting has emerged as a promising tool for recapitulating the complex and highly organized architecture of skeletal muscles at clinically relevant sizes. Here, skeletal muscle physiology, muscle regeneration following injury, and current treatments following muscle loss are discussed, and then bioprinting strategies implemented for SMTE are critically reviewed. Subsequently, recent advancements that have led to improvement of bioprinting strategies to construct large muscle structures, boost myogenesis in vitro and in vivo, and enhance tissue integration are discussed. Bioinks for muscle bioprinting, as an essential part of any bioprinting strategy, are discussed, and their benefits, limitations, and areas to be improved are highlighted. Finally, the directions the field should expand to make bioprinting strategies more translational and overcome the clinical unmet needs are discussed.
Topics: Bioprinting; Muscle, Skeletal; Printing, Three-Dimensional; Tissue Engineering; Tissue Scaffolds
PubMed: 34773667
DOI: 10.1002/adma.202105883