Muscle regeneration

AIM OF THE STUDY: Blepharoptosis is a drooping of the upper eyelid, usually due to dysfunction of the levator palpebrae superioris (LPS). Recently, skeletal muscle satellite cells (SSCs) have been reported to promote the repair of damaged skeletal muscle. This study aims to investigate the potential contribution of exogenous SSCs to the regeneration of mechanically damaged LPS. MATERIALS AND METHODS: Thirty-two rats were randomly divided into four groups, including control group, SSCs-treated group, SSCs-treated injury group and non-treated injury group...

To investigate satellite cells (SCs) and myonuclei characteristics in patients with rheumatoid arthritis (RA). Resting biopsies from m. vastus lateralis were obtained from thirteen RA patients and thirteen matched healthy controls (CON). Muscle biopsies were immunohistochemically stained and analyzed for fiber type specific content of SCs (Pax7+ ), proliferating SCs (Pax7+ /MyoD+ ) and differentiating SCs (myogenin+ ). Furthermore, we quantified fiber type specific content of myonuclei and myofiber cross-sectional area (CSA)...

Decellularized tissues have been increasingly popular for constructing scaffolds for tissue engineering applications due to their beneficial biological compositions and mechanical properties. It is therefore natural to consider decellularized trachea for construction of tissue-engineered trachea as well as other tubular organs. A neo-urinary conduit (NUC) is such a tubular organ that works as a passage for urine removal in bladder cancer patients who need a urinary diversion after their diseased bladder is removed...

Small-diameter (<6 mm) vascular grafts are increasingly needed in peripheral vascular surgery but have few successes because of acute thrombosis, incomplete endothelialization and intimal hyperplasia after implantation. This study used electrospun poly(ε-caprolactone) as the matrix material. Heparin and selenium-containing catalyst-organoselenium modified polyethyleneimine were introduced through layer-by-layer assembly in order to build a vascular graft with in situ nitric oxide (NO) generation. The aim of this study was to explore the application of the graft with improved histocompatibility and biological function for vascular implantation in rats...

Regulation of gene expression requires selective incorporation of histone H3 variant H3.3 into chromatin. Histone H3.3 has several subsidiary variants but their functions are unclear. Here we characterize the function of histone H3.3 sub-variant, H3mm7, which is expressed in skeletal muscle satellite cells. H3mm7 knockout mice demonstrate an essential role of H3mm7 in skeletal muscle regeneration. Chromatin analysis reveals that H3mm7 facilitates transcription by forming an open chromatin structure around promoter regions including those of myogenic genes...

Fibrosis following injury leads to aberrant regeneration and incomplete functional recovery of skeletal muscle, but the lack of detailed knowledge about the cellular and molecular mechanisms involved hampers the design of effective treatments. Using state-of-the-art technologies, Murray et al. (2017) found that perivascular PDGFRβ-expressing cells generate fibrotic cells in the skeletal muscle. Strikingly, genetic deletion of αv integrins from perivascular PDGFRβ-expressing cells significantly inhibited skeletal muscle fibrosis without affecting muscle vascularization or regeneration...

Collagen XIII occurs as both a transmembrane-bound and a shed extracellular protein, and is able to regulate the formation and function of neuromuscular synapses. Its absence results in myasthenia, i.e. pre-and postsynaptic defects at the neuromuscular junction (NMJ), leading to destabilization of the motor nerves, muscle regeneration and atrophy. Mutations in COL13A1 have recently been found to cause congenital myasthenic syndrome (CMS), characterized by fatigue and chronic muscle weakness, which may be lethal...

Frankincense can promote blood circulation. Acetyl-11-keto-β-boswellic acid (AKBA) is a small molecule with anti-inflammatory properties that is derived from Boswellia serrata. Here, we hypothesized that it may promote regeneration of injured sciatic nerve. To address this hypothesis, we established a rat model of sciatic nerve injury using a nerve clamping method. Rats were administered AKBA once every 2 days at doses of 1.5, 3, and 6 mg/kg by intraperitoneal injection for 30 days from the 1st day after injury...

Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture- and moxibustion-based mechanisms underlying nerve repair are still unclear. Here, in vivo and in vitro experiments uncovered one mechanism through which electroacupuncture and moxibustion affect regeneration after peripheral nerve injury. We first established rat models of sciatic nerve injury using neurotomy. Rats were treated with electroacupuncture or moxibustion at acupoints Huantiao (GB30) and Zusanli (ST36)...

Immune-mediated necrotizing myopathies (IMNMs) are a group of acquired autoimmune muscle disorders that have been recently defined. They are characterized by proximal muscle weakness, high levels of creatinine kinase, and myopathic findings on electromyogram (EMG). Muscle biopsy in IMNM differentiates it from the other subgroups of idiopathic inflammatory myositis (IIM) by the presence of myofibre necrosis and prominent regeneration without substantial lymphocytic inflammatory infiltrates. Anti-signal recognition particle (SRP) and anti-3hydroxy-3 methylglutaryl-coenzyme A reductase (HMGCR) autoantibodies were found in two thirds of IMNM patients...

Marine pearl production is directly influenced by the growth speed of Pinctada fucata martensii. However, the slow growth rate of this organism remains the main challenge in aquaculture production. Epidermal growth factor receptor (EGFR), an important receptor of tyrosine kinases in animals, plays versatile functions in development, growth and tissue regeneration. In this study, we described the characteristic and function of an EGFR gene identified from P. f. martensii (PmEGFR). PmEGFR possesses a typical EGFR structure and is expressed in all studied tissues, with the highest expression level in adductor muscle...

Sarcopenia is an age-related generalized loss of muscle mass and muscle strength resulting in low physical performance, which can be observed in up to 50% of >80-year-old individuals. The consequences are manifold and sarcopenia is closely linked to frailty. Important risk factors are genetics/epigenetics, immobilization, malnutrition and anorexia, hormone deficiencies, chronic inflammation and raised levels of inhibitory factors of tissue regeneration. Thus, functional assessment of muscle strength and physical performance are central components of diagnosing sarcopenia, beyond the mere quantification of muscle mass...

Myogenesis is a complex process required for skeletal muscle formation during embryonic development and for regeneration and growth of myofibers in adults. Accumulating evidence suggests that long non-coding RNAs (lncRNAs) play key roles in regulating cell fate decision and function in various tissues. However, the role of lncRNAs in the regulation of myogenesis remains poorly understood. In this study, we identified a novel muscle-enriched lncRNA called "Myolinc (AK142388)", which we functionally characterized in the C2C12 myoblast cell line...

Muscle satellite cells (SC) are resident stem-like cells that play an integral role in skeletal muscle growth and repair. Understanding how SC maintain their identities and dynamic properties is critical to animal growth. However, the genetic and environmental factors governing SC behaviors and the underpinning mechanisms remain unknown. To explore whether genetic selection influences SC behaviors, we used 2 lines of chickens selected for over 50 generations with over a 10-fold difference in body weight at 56 d of age-the Virginia high weight selection (HWS) and low weight selection (LWS) lines...

Skeletal muscle function is highly dependent on the ability to regenerate, however, during ageing or disease, the proliferative capacity is reduced, leading to loss of muscle function. We have previously demonstrated the presence of vitamin K2 in bovine skeletal muscles, but whether vitamin K has a role in muscle regulation and function is unknown. In this study, we used primary bovine skeletal muscle cells, cultured in monolayers in vitro, to assess a potential effect of vitamin K2 (MK-4) during myogenesis of muscle cells...

The use of synthetic materials for biomedical applications still presents issues owing to the potential for unfavourable safety characteristics. Currently, there is increasing interest in using natural, marine-derived raw materials for bone tissue engineering. In our study, the endoskeleton of the mollusc Sepia, i.e. cuttlebone (CB), was used with regenerated cellulose (RC) to prepare three-dimensional composite bone grafts. CB microparticles were mechanically immobilised within a cellulose gel, resulting in a macroporous structure upon lyophilisation...

The extracellular guanosine 5'-triphosphate, GTP, has been demonstrated to be an enhancer of myogenic cell differentiation in a murine cell line, not yet in human muscle cells. Our hypothesis was that GTP could influence also human skeletal muscle regeneration, specifically in the first phases. We tested GTP stimulus on human muscle precursor cells established in culture by human satellite cells derived from Vastus Lateralis of three young male. Our data show that extracellular GTP (a) up-regulated miRNA (specifically miR133a and miR133b) and myogenic regulator factor and (b) induces human myogenic precursor cells to release exosomes stuffed with guanosine based molecules (mainly guanosine) in the extracellular milieu...

BACKGROUND: Skeletal muscle plays an important role in the body's physiology but there are still no effective treatments for volumetric muscle loss (VML) resulting from severe traumatic injury or tumor excision. Recent studies show that a tissue engineering strategy using a compound containing mesenchymal stem cells (MSCs) and decellularized extracellular matrix (ECM) scaffold generates significant regenerative effects on VML injury, but the underlying mechanisms are not fully understood...

BACKGROUND: Mesenchymal stem cell (MSC) transplantation shows promise for treating transplant arteriosclerosis, at least partly via promoting endothelial regeneration. However, the efficacy and safety are still under investigation especially regarding recent findings that neointimal smooth muscle cells are derived from MSC-like cells. The high mobility group box 1 (HMGB1)/receptor for advanced glycation end-product (RAGE) axis is involved in regulating proliferation, migration, and differentiation of MSCs, and therefore it can be presumably applied to improve the outcome of cell therapy...

Objective: To investigate the risk factors for multiparous pelvic floor muscles injury during 6-8 weeks after delivery. Method: From June 2015 to April 2017, 1917 women (1 523 primigravidas and 294 multiparas) were accepted postpartum pelvic floor function screening during 6-8 weeks after delivery in Beijing Hospital.Pelvic examination and pelvic floor muscle strength testing were carried out in these women.All the data were analyzed with multivariate logistic regression method to explore the related factors for postpartum pelvic floor muscle injury...