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Mammalian Genome : Official Journal of... Dec 2016This review assesses the importance of proteostasis in skeletal muscle maintenance with a specific emphasis on autophagy. Skeletal muscle appears to be particularly... (Review)
Review
This review assesses the importance of proteostasis in skeletal muscle maintenance with a specific emphasis on autophagy. Skeletal muscle appears to be particularly vulnerable to genetic defects in basal and induced autophagy, indicating that autophagy is co-substantial to skeletal muscle maintenance and adaptation. We discuss emerging evidence that tension-induced protein unfolding may act as a direct link between mechanical stress and autophagic pathways. Mechanistic links between protein damage, autophagy and muscle hypertrophy, which is also induced by mechanical stress, are still poorly understood. However, some mouse models of muscle disease show ameliorated symptoms upon effective targeting of basal autophagy. These findings highlight the importance of autophagy as therapeutic target and suggest that elucidating connections between protein unfolding and mTOR-dependent or mTOR-independent hypertrophic responses is likely to reveal specific therapeutic windows for the treatment of muscle wasting disorders.
Topics: Adaptation, Physiological; Animals; Autophagy; Humans; Hypertrophy; Mice; Muscle, Skeletal; Muscular Diseases; Protein Unfolding; Proteostasis; Signal Transduction; Stress, Mechanical; TOR Serine-Threonine Kinases
PubMed: 27484057
DOI: 10.1007/s00335-016-9659-2 -
European Review For Medical and... 2016The association of bilateral hypertrophy of temporalis and masseteric muscles is a rare clinical entity. The origin of the condition is unclear, causing cosmetic... (Review)
Review
OBJECTIVE
The association of bilateral hypertrophy of temporalis and masseteric muscles is a rare clinical entity. The origin of the condition is unclear, causing cosmetic problems, pain, and functional impairment.
PATIENTS AND METHODS
In this paper we analyzed 15 patients treated at the Department of Maxillo-Facial Surgery of the University of Naples Federico II, from 2000 to 2013, for temporalis and/or masseteric muscle hypertrophy, and in particular, a rare case of a patient with a marked bilateral swelling of the temporalis and masseteric region, in conjunction with a review of the literature.
RESULTS
Fourteen patients have not any kind of postoperatively problems. The last patient had been aware of the swelling for many years and complained of recurrent headaches. We adopted a new protocol fort this patients and the patient was very pleased with the treatment results, and reported a reduction in headaches and a continuation of his well-being, in addition to greater self-confidence. The last follow-up was performed three years after the first treatment, and the patient showed a complete resolution of his symptoms, and just a small increase of the swelling.
CONCLUSIONS
The treatment of temporalis and masseteric hypertrophy with Botulin toxin could be an effective option compared to conservative treatment or surgical intervention, although the review of the literature shows that this is only a temporary treatment. In fact, surgery still remains the best option. The treatment must be repeated every 4/6 months for 2-3 consecutive years before having stable benefits. To overcome this problem, an association with a bite treatment allowed us to achieve more lasting and more stable results over time without a recurrence of symptoms between the treatments. Furthermore, this association has enabled us to obtain a more rapid reduction of the hypertrophy.
Topics: Adult; Aged; Botulinum Toxins, Type A; Female; Humans; Hypertrophy; Injections, Intramuscular; Male; Masseter Muscle; Middle Aged; Neuromuscular Agents; Temporal Muscle; Treatment Outcome
PubMed: 26813447
DOI: No ID Found -
Journal of Cachexia, Sarcopenia and... Feb 2019Perilipin2 (Plin2) belongs to a family of five highly conserved proteins, known for their role in lipid storage. Recent data indicate that Plin2 has an important...
BACKGROUND
Perilipin2 (Plin2) belongs to a family of five highly conserved proteins, known for their role in lipid storage. Recent data indicate that Plin2 has an important function in cell metabolism and is involved in several human pathologies, including liver steatosis and Type II diabetes. An association between Plin2 and lower muscle mass and strength has been found in elderly and inactive people, but its function in skeletal muscle is still unclear. Here, we addressed the role of Plin2 in adult muscle by gain and loss of function experiments.
METHODS
By mean of in vivo Plin2 down-regulation (shPlin2) and overexpression (overPlin2) in murine tibialis anterior muscle, we analysed the effects of Plin2 genetic manipulations on myofiber size and lipid composition. An analysis of skeletal muscle lipid composition was also performed in vastus lateralis samples from young and old patients undergoing hip surgery.
RESULTS
We found that Plin2 down-regulation was sufficient to induce a 30% increase of myofiber cross-sectional area, independently of mTOR pathway. Alterations of lipid content and modulation of genes involved in lipid synthesis occurred in hypertrophic muscles. In particular, we showed a decrease of triglycerides, ceramides, and phosphatidylcoline:phosphatidylethanolamine ratio, a condition known to impact negatively on muscle function. Plin2 overexpression did not change fibre size; however, lipid composition was strongly affected in a way that is similar to that observed in human samples from old patients.
CONCLUSIONS
Altogether these data indicate that Plin2 is a critical mediator for the control of muscle mass, likely, but maybe not exclusively, through its critical role in the regulation of intracellular lipid content and composition.
Topics: Adult; Aged, 80 and over; Animals; Down-Regulation; Female; Humans; Hypertrophy; Lipid Metabolism; Male; Mice, Inbred C57BL; Muscle, Skeletal; Perilipin-2
PubMed: 30288961
DOI: 10.1002/jcsm.12355 -
Physiological Reports Sep 2020This study aimed to review the effects of ladder-based resistance training (LRT) on muscle hypertrophy and strength in rodents through a systematic review with... (Meta-Analysis)
Meta-Analysis
This study aimed to review the effects of ladder-based resistance training (LRT) on muscle hypertrophy and strength in rodents through a systematic review with meta-analysis. We systematically searched PubMed/Medline, SportDiscuss, Scopus, Google Scholar, Science Direct, and Scielo database on May 18, 2020. Thirty-four studies were included measuring total (mCSA) or mean muscle fibers cross-sectional area (fCSA) or maximum load-carrying capacity (MLCC) or muscle mass (MM). About the main results, LRT provides sufficient mechanical stimulation to increase mCSA and fCSA. Meta-analysis showed a significant overall effect on the fCSA (SMD 1.89, 95% CI [1.18, 2.61], p < .00001, I = 85%); however, subgroup analysis showed that some muscle types might not be hypertrophied through the LRT. Meta-analysis showed a significant training effect on the MM (SMD 0.92, 95% CI [0.52, 1.32], p < .00001, I = 72%). Sub-group analysis revealed that soleus (SMD 1.32, 95% CI [0.11, 2.54], p = .03, I = 86%) and FHL (SMD 1.92, 95% CI [1.00, 2.85], p < .0001, I = 71%) presented significant training effects, despite moderate heterogeneity levels (I = 72%). MLCC increases considerably after a period of LRT, regardless of its duration and the characteristics of the protocols (SMD 12.37, 95% CI [9.36, 15.37], p < .00001, I = 90%). Through these results, we reach the following conclusions: (a) LRT is efficient to induce muscle hypertrophy, although this effect varies between different types of skeletal muscles, and; (b) the ability of rodents to carry load increases regardless of the type and duration of the protocol used.
Topics: Animals; Hypertrophy; Mice; Muscle Strength; Muscle, Skeletal; Physical Conditioning, Animal; Rats
PubMed: 32889774
DOI: 10.14814/phy2.14502 -
STAR Protocols Mar 2022The skeletal muscle system is the major organ associated with movement of the body. Myogenesis and regeneration induced post-injury contribute to muscle formation and...
The skeletal muscle system is the major organ associated with movement of the body. Myogenesis and regeneration induced post-injury contribute to muscle formation and maintenance. Here, we provide detailed protocol for the accelerated repair of injured skeletal muscles and generation of hypertrophic muscle fibers. This protocol includes cardiotoxin induced muscle injury and also describes isolation of satellite cells from skeletal muscle tissues of mice. This protocol can be used to study the mechanisms associated with accelerated muscle repair and hypertrophy. For complete details on the use and execution of this protocol, please refer to Ray et al. (2021).
Topics: Animals; Hypertrophy; Mice; Mice, Inbred C57BL; Muscle, Skeletal; Muscular Diseases; Regeneration
PubMed: 35118424
DOI: 10.1016/j.xpro.2021.101111 -
International Journal of Molecular... Apr 2022Long noncoding RNA (lncRNA) plays a crucial part in all kinds of life activities, especially in myogenesis. (SWI/SNF-related, matrix-associated, actin-dependent...
Long noncoding RNA (lncRNA) plays a crucial part in all kinds of life activities, especially in myogenesis. (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily d, member 3) is a member of the SWI/SNF protein complex and was reported to be required for cell proliferation and myoblast differentiation. In this study, we identified a new lncRNA named (), which strongly regulated the development of myogenesis by improving the expression of (). We overexpressed and knockdown the expression of and to investigate their function on myoblast proliferation and differentiation. Cell experiments proved that and promoted myoblast proliferation through the pathway and improved differentiation of differentiated myoblasts through the pathway. Moreover, they upregulated the fast-twitch fiber-related genes and downregulated the slow-twitch fiber-related genes, which indicated that they facilitated the slow-twitch fiber to transform into the fast-twitch fiber. The animals' experiments supported the results above, demonstrating that could induce muscle hypertrophy and fast-twitch fiber transformation. In conclusion, can improve the expression of , thus inducing muscle hypertrophy. In addition, can facilitate slow-twitch fibers to transform into fast-twitch fibers.
Topics: Animals; Cell Differentiation; Hypertrophy; Muscle Development; Muscles; Myoblasts; RNA, Long Noncoding
PubMed: 35562902
DOI: 10.3390/ijms23094510 -
Neurology Dec 2014
Topics: Adult; Biopsy; Electromyography; Humans; Hypertrophy; Male; Muscle, Skeletal
PubMed: 25452457
DOI: 10.1212/WNL.0000000000001048 -
Journal of Strength and Conditioning... Oct 2023Nakao, S, Ikezoe, T, Taniguchi, M, Motomura, Y, Hirono, T, Nojiri, S, Hayashi, R, Tanaka, H, and Ichihashi, N. Effects of low-intensity torque-matched isometric training... (Randomized Controlled Trial)
Randomized Controlled Trial
Effects of Low-Intensity Torque-Matched Isometric Training at Long and Short Muscle Lengths of the Hamstrings on Muscle Strength and Hypertrophy: A Randomized Controlled Study.
Nakao, S, Ikezoe, T, Taniguchi, M, Motomura, Y, Hirono, T, Nojiri, S, Hayashi, R, Tanaka, H, and Ichihashi, N. Effects of low-intensity torque-matched isometric training at long and short muscle lengths of the hamstrings on muscle strength and hypertrophy: A randomized controlled study. J Strength Cond Res 37(10): 1978-1984, 2023-This study investigated the effects of low-intensity torque-matched isometric training on muscle hypertrophy and strengthening at long (LL) and short muscle lengths (SL). Twenty-eight young subjects completed an 8-week hamstring isometric training program (30% of maximal voluntary contraction (MVC) × 5 s × 20 repetitions × 5 sets × 3 times/week) at 30° knee flexion (LL) or 90° knee flexion (SL). The cross-sectional area (CSA) of the hamstrings and MVC were measured before and after the intervention. The active torque because of muscle contraction was calculated by subtracting the passive torque at rest from the total torque (30% MVC). The active torque was significantly lower in the LL training group than in the SL training group (p < 0.01), whereas there was no between-group difference in total torque during training. For CSA and MVC at 30° knee flexion, the split-plot analysis of variance (ANOVA) showed no significant time × group interaction; however, it did show a significant main effect of time (p < 0.05), indicating a significant increase after training intervention. As for MVC at 90° knee flexion, there was a significant time × group interaction (p < 0.05) and a significant simple main effect of time in both the LL (p < 0.01; Cohen's d effect size [ES] = 0.36) and SL (p < 0.01; ES = 0.64) training groups. Therefore, low-intensity isometric training at LL can induce hypertrophy and strengthening, even in cases where the active torque production is lower than that at SL, whereas the training at SL may be more effective for muscle strengthening at SL.
Topics: Humans; Torque; Muscle Strength; Hamstring Muscles; Hypertrophy; Muscles
PubMed: 37729512
DOI: 10.1519/JSC.0000000000004510 -
Physiological Research Aug 2023G protein-coupled receptor 81 (GPR81), a selective receptor for lactate, expresses in skeletal muscle cells, but the physiological role of GPR81 in skeletal muscle has...
G protein-coupled receptor 81 (GPR81), a selective receptor for lactate, expresses in skeletal muscle cells, but the physiological role of GPR81 in skeletal muscle has not been fully elucidated. As it has been reported that the lactate administration induces muscle hypertrophy, the stimulation of GPR81 has been suggested to mediate muscle hypertrophy. To clarify the contribution of GPR81 activation in skeletal muscle hypertrophy, in the present study, we investigated the effect of GPR81 agonist administration on skeletal muscle mass in mice. Male C57BL/6J mice were randomly divided into control group and GPR81 agonist-administered group that received oral administration of the specific GPR81 agonist 3-Chloro-5-hydroxybenzoic acid (CHBA). In both fast-twitch plantaris and slow-twitch soleus muscles of mice, the protein expression of GPR81 was observed. Oral administration of CHBA to mice significantly increased absolute muscle weight and muscle weight relative to body weight in the two muscles. Moreover, both absolute and relative muscle protein content in the two muscles were significantly increased by CHBA administration. CHBA administration also significantly upregulated the phosphorylation level of p42/44 extracellular signal-regulated kinase-1/2 (ERK1/2) and p90 ribosomal S6 kinase (p90RSK). These observations suggest that activation of GRP81 stimulates increased the mass of two types of skeletal muscle in mice in vivo. Lactate receptor GPR81 may positively affect skeletal muscle mass through activation of ERK pathway.
Topics: Mice; Male; Animals; Lactic Acid; Mice, Inbred C57BL; Muscle, Skeletal; Muscle Fibers, Skeletal; Receptors, G-Protein-Coupled; Hypertrophy
PubMed: 37795889
DOI: 10.33549/physiolres.935004 -
Plastic and Reconstructive Surgery Jan 2019Masseter muscle hypertrophy manifests itself as enlargement of the masseter muscle. It can be associated with a square-angled lower face, pain, dental attrition,... (Review)
Review
BACKGROUND
Masseter muscle hypertrophy manifests itself as enlargement of the masseter muscle. It can be associated with a square-angled lower face, pain, dental attrition, maxillary and mandibular bone resorption, and accelerated aging process of the lower face. The objective of this study was to assess the efficacy and safety of botulinum toxin type A in contouring the masseter and its impact on quality of life and the aging process of the lower face, and its role in full face rejuvenation.
METHODS
A PubMed search was conducted for articles on masseter treatment with botulinum toxin type A, masseter muscle hypertrophy, and the aging process of the lower face. Key studies are reviewed and findings are summarized.
RESULTS
Botulinum toxin type A can be injected into the lower posterior aspect of the masseter muscle. Treatment decreases muscle bulk and reshapes the lower face. Furthermore, patient quality-of-life measures, including pain and symptoms of grinding and clenching, are improved. Treatment can decrease shear stress on maxillary and mandibular bones and can possibly prevent tooth loss and progressive bone resorption of the lower face. Adverse effects are minimal and short lasting.
CONCLUSIONS
Botulinum toxin type A is a safe and effective treatment of masseter hypertrophy. The treatment results in improvement of functionality and cosmesis, and restoration of facial harmony.
Topics: Adult; Aged; Aging; Botulinum Toxins, Type A; Bruxism; Esthetics; Female; Humans; Hypertrophy; Injections, Intralesional; Male; Masseter Muscle; Middle Aged; Quality of Life; Risk Assessment; Treatment Outcome
PubMed: 30303926
DOI: 10.1097/PRS.0000000000005083