Intermediate filaments in smooth muscle from pregnant and non-pregnant human uterus.

OpenAIRE

Leoni, P; Carli, F; Halliday, D

1990-01-01

The intermediate filament proteins desmin and vimentin from pregnant and non-pregnant uterine muscle and smooth-muscle cells in culture were analysed using SDS/PAGE. The desmin content in uterine muscle increases dramatically during pregnancy, whereas vimentin remains unchanged or changes very little. When muscle cells are kept in culture, a considerable increase in vimentin content is observed as compared with vimentin in freshly isolated non-pregnant uterine tissue. Our results strengthen t...

Functional heterogeneity of side population cells in skeletal muscle

International Nuclear Information System (INIS)

Uezumi, Akiyoshi; Ojima, Koichi; Fukada, So-ichiro; Ikemoto, Madoka; Masuda, Satoru; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi

2006-01-01

Skeletal muscle regeneration has been exclusively attributed to myogenic precursors, satellite cells. A stem cell-rich fraction referred to as side population (SP) cells also resides in skeletal muscle, but its roles in muscle regeneration remain unclear. We found that muscle SP cells could be subdivided into three sub-fractions using CD31 and CD45 markers. The majority of SP cells in normal non-regenerating muscle expressed CD31 and had endothelial characteristics. However, CD31 - CD45 - SP cells, which are a minor subpopulation in normal muscle, actively proliferated upon muscle injury and expressed not only several regulatory genes for muscle regeneration but also some mesenchymal lineage markers. CD31 - CD45 - SP cells showed the greatest myogenic potential among three SP sub-fractions, but indeed revealed mesenchymal potentials in vitro. These SP cells preferentially differentiated into myofibers after intramuscular transplantation in vivo. Our results revealed the heterogeneity of muscle SP cells and suggest that CD31 - CD45 - SP cells participate in muscle regeneration

Application of cell co-culture system to study fat and muscle cells.

Science.gov (United States)

Pandurangan, Muthuraman; Hwang, Inho

2014-09-01

Animal cell culture is a highly complex process, in which cells are grown under specific conditions. The growth and development of these cells is a highly unnatural process in vitro condition. Cells are removed from animal tissues and artificially cultured in various culture vessels. Vitamins, minerals, and serum growth factors are supplied to maintain cell viability. Obtaining result homogeneity of in vitro and in vivo experiments is rare, because their structure and function are different. Living tissues have highly ordered complex architecture and are three-dimensional (3D) in structure. The interaction between adjacent cell types is quite distinct from the in vitro cell culture, which is usually two-dimensional (2D). Co-culture systems are studied to analyze the interactions between the two different cell types. The muscle and fat co-culture system is useful in addressing several questions related to muscle modeling, muscle degeneration, apoptosis, and muscle regeneration. Co-culture of C2C12 and 3T3-L1 cells could be a useful diagnostic tool to understand the muscle and fat formation in animals. Even though, co-culture systems have certain limitations, they provide a more realistic 3D view and information than the individual cell culture system. It is suggested that co-culture systems are useful in evaluating the intercellular communication and composition of two different cell types.

A muscle stem cell for every muscle: variability of satellite cell biology among different muscle groups

Science.gov (United States)

Randolph, Matthew E.; Pavlath, Grace K.

2015-01-01

The human body contains approximately 640 individual skeletal muscles. Despite the fact that all of these muscles are composed of striated muscle tissue, the biology of these muscles and their associated muscle stem cell populations are quite diverse. Skeletal muscles are affected differentially by various muscular dystrophies (MDs), such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in the pathology of some MDs. The biology of muscle stem cells varies depending on the muscles with which they are associated. Here we review the biology of skeletal muscle stem cell populations of eight different muscle groups. Understanding the biological variation of skeletal muscles and their resident stem cells could provide valuable insight into mechanisms underlying the susceptibility of certain muscles to myopathic disease. PMID:26500547

Novel Therapeutic Effects of Non-thermal atmospheric pressure plasma for Muscle Regeneration and Differentiation

Science.gov (United States)

Choi, Jae Won; Kang, Sung Un; Kim, Yang Eun; Park, Ju Kyeong; Yang, Sang Sik; Kim, Yeon Soo; Lee, Yun Sang; Lee, Yuijina; Kim, Chul-Ho

2016-01-01

Skeletal muscle can repair muscle tissue damage, but significant loss of muscle tissue or its long-lasting chronic degeneration makes injured skeletal muscle tissue difficult to restore. It has been demonstrated that non-thermal atmospheric pressure plasma (NTP) can be used in many biological areas including regenerative medicine. Therefore, we determined whether NTP, as a non-contact biological external stimulator that generates biological catalyzers, can induce regeneration of injured muscle without biomaterials. Treatment with NTP in the defected muscle of a Sprague Dawley (SD) rat increased the number of proliferating muscle cells 7 days after plasma treatment (dapt) and rapidly induced formation of muscle tissue and muscle cell differentiation at 14 dapt. In addition, in vitro experiments also showed that NTP could induce muscle cell proliferation and differentiation of human muscle cells. Taken together, our results demonstrated that NTP promotes restoration of muscle defects through control of cell proliferation and differentiation without biological or structural supporters, suggesting that NTP has the potential for use in muscle tissue engineering and regenerative therapies. PMID:27349181

Expression of interleukin-15 in human skeletal muscle effect of exercise and muscle fibre type composition

DEFF Research Database (Denmark)

Nielsen, Anders Rinnov; Mounier, Remi; Plomgaard, Peter

2007-01-01

The cytokine interleukin-15 (IL-15) has been demonstrated to have anabolic effects in cell culture systems. We tested the hypothesis that IL-15 is predominantly expressed by type 2 skeletal muscle fibres, and that resistance exercise regulates IL-15 expression in muscle. Triceps brachii, vastus...... lateralis quadriceps and soleus muscle biopsies were obtained from normally physically active, healthy, young male volunteers (n = 14), because these muscles are characterized by having different fibre-type compositions. In addition, healthy, normally physically active male subjects (n = 8) not involved...

Study of muscle cell dedifferentiation after skeletal muscle injury of mice with a Cre-Lox system.

Science.gov (United States)

Mu, Xiaodong; Peng, Hairong; Pan, Haiying; Huard, Johnny; Li, Yong

2011-02-03

Dedifferentiation of muscle cells in the tissue of mammals has yet to be observed. One of the challenges facing the study of skeletal muscle cell dedifferentiation is the availability of a reliable model that can confidentially distinguish differentiated cell populations of myotubes and non-fused mononuclear cells, including stem cells that can coexist within the population of cells being studied. In the current study, we created a Cre/Lox-β-galactosidase system, which can specifically tag differentiated multinuclear myotubes and myotube-generated mononuclear cells based on the activation of the marker gene, β-galactosidase. By using this system in an adult mouse model, we found that β-galactosidase positive mononuclear cells were generated from β-galactosidase positive multinuclear myofibers upon muscle injury. We also demonstrated that these mononuclear cells can develop into a variety of different muscle cell lineages, i.e., myoblasts, satellite cells, and muscle derived stem cells. These novel findings demonstrated, for the first time, that cellular dedifferentiation of skeletal muscle cells actually occurs in mammalian skeletal muscle following traumatic injury in vivo.

Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration

Science.gov (United States)

Dezawa, Mari; Ishikawa, Hiroto; Itokazu, Yutaka; Yoshihara, Tomoyuki; Hoshino, Mikio; Takeda, Shin-ichi; Ide, Chizuka; Nabeshima, Yo-ichi

2005-07-01

Bone marrow stromal cells (MSCs) have great potential as therapeutic agents. We report a method for inducing skeletal muscle lineage cells from human and rat general adherent MSCs with an efficiency of 89%. Induced cells differentiated into muscle fibers upon transplantation into degenerated muscles of rats and mdx-nude mice. The induced population contained Pax7-positive cells that contributed to subsequent regeneration of muscle upon repetitive damage without additional transplantation of cells. These MSCs represent a more ready supply of myogenic cells than do the rare myogenic stem cells normally found in muscle and bone marrow.

Influence of exercise contraction mode and protein supplementation on human skeletal muscle satellite cell content and muscle fiber growth

DEFF Research Database (Denmark)

Farup, Jean; Rahbek, Stine Klejs; Riis, Simon

2014-01-01

-specific association between emergence of satellite cells (SCs), muscle growth, and remodeling in response to 12 wk unilateral resistance training performed as eccentric (Ecc) or concentric (Conc) resistance training ± whey protein (Whey, 19.5 g protein + 19.5 g glucose) or placebo (Placebo, 39 g glucose......Skeletal muscle satellite cells (SCs) are involved in remodeling and hypertrophy processes of skeletal muscle. However, little knowledge exists on extrinsic factors that influence the content of SCs in skeletal muscle. In a comparative human study, we investigated the muscle fiber type......) supplementation. Muscle biopsies (vastus lateralis) were analyzed for fiber type-specific SCs, myonuclei, and fiber cross-sectional area (CSA). Following training, SCs increased with Conc in both type I and type II fibers (P

Voluntary wheel running increases satellite cell abundance and improves recovery from disuse in gastrocnemius muscles from mice.

Science.gov (United States)

Brooks, Matthew J; Hajira, Ameena; Mohamed, Junaith S; Alway, Stephen E

2018-02-22

Reloading of atrophied muscles after hindlimb suspension unloading (HSU) can induce injury and prolong recovery. Low-impact exercise, such as voluntary wheel running, has been identified as a non-damaging rehabilitation therapy in rodents, but its effects on muscle function, morphology, and satellite cell activity after HSU are unclear. This study tested the hypothesis that low impact wheel running would increase satellite cell proliferation and improve recovery of muscle structure and function after HSU in mice. Young adult male and female C57BL/6 mice (n=6/group) were randomly placed into 5 groups. These included HSU without recovery (HSU), normal ambulatory recovery for 14 days after HSU (HSU+NoWR), and voluntary wheel running recovery for 14 days after HSU (HSU+WR). Two control groups were used: non-suspended mice-cage controls (Control) and voluntary wheel running controls (ControlWR). Satellite cell activation, was evaluated by providing mice 5-bromo-2'-deoxyuridine (BrdU) in their drinking water. As expected, HSU significantly reduced in vivo maximal force and decreased the in vivo fatigability and decreased type I and IIa myosin heavy chain (MHC) abundance in plantarflexor muscles. HSU+WR mice significantly improved plantarflexor fatigue resistance, increased type type I and IIa MHC abundance, increased fiber cross sectional area (CSA), and an increased the percentage of type I and IIA muscle fibers in the gastrocnemius muscle. HSU+WR mice also had a significantly greater percentage of BrdU-positive and Pax 7 positive nuclei inside muscle fibers and a greater MyoD to Pax 7 protein ratio when compared to HSU+NoWR mice. The mechanotransduction protein Yes-associated protein (YAP) was elevated with reloading after HSU, but HSU+WR had lower levels of the inactive phosphorylated YAP serine127 which may have contributed to increased satellite cell activation creased with reloading after HSU. These results indicate that voluntary wheel running increased YAP

The role of Six1 in muscle progenitor cells and the establishment of fast-twitch muscle fibres

OpenAIRE

Nord, Hanna

2014-01-01

Myogenesis is the process of skeletal muscle tissue formation where committed muscle progenitor cells differentiate into skeletal muscle fibres. Depending on the instructive cues the muscle progenitor cells receive they will differentiate into specific fibre types with different properties. The skeletal muscle fibres can be broadly classified as fast-twitch fibres or slow-twitch fibres, based on their contractile speed. However, subgroups of fast- and slow-twitch fibres with different metabol...

Intramuscular diffuse-type giant cell tumor within the hamstring muscle

International Nuclear Information System (INIS)

Yoshida, Tatsuya; Sakamoto, Akio; Tanaka, Kazuhiro; Iwamoto, Yukihide; Oda, Yoshinao; Izumi, Teiyu; Tsuneyoshi, Masazumi

2007-01-01

Diffuse-type giant cell tumor (D-TGCT) is known as a synonym for pigmented villonodular synovitis (PVS), a condition usually found in the large joints. We report an extremely rare case of D-TGCT which was located within the hamstring muscle. The lesion was an incidental finding in a 62-year-old man who underwent positron emission tomography (PET) as part of a staging evaluation for gastric cancer. The lesion was resected. There has been neither metastasis nor recurrence during the 6-month period since resection. This case demonstrates that PVS/D-TGCT may have a high SUV on PET imaging, and for this reason PET may be useful for detecting both the tumor and any recurrence. (orig.)

Cellular location of rat muscle ferritins and their preferential loss during cell isolation.

Science.gov (United States)

Linder, M C; Roboz, M; McKown, M J; Pardridge, W M; Zak, R

1984-04-10

Heart and other muscles of the rat contain two forms of ferritin separable in polyacrylamide gel electrophoresis. The cellular location of the fast- and slow-migrating ferritins was investigated using primary cultures of hindlimb skeletal muscle, and isolated myocardial cell populations. Muscle and non-muscle cells were isolated in good yield from hearts of adult rats pretreated with large doses of iron to increase their ferritin content. In virtually all cases, the isolated muscle cells contained traces only of the fast-migrating species and the non-muscle cells contained small amounts of the slow-migrating ferritin. During cell isolation, 90-100% of both ferritins was lost and could be recovered in the perfusates and solutions employed, while one third of the total tissue protein, and a larger percentage of creatine phosphokinase, was recovered in the isolated cells. Primary cultures of thigh muscle from adult rats which had differentiated into multi-nucleated myotubes, were incubated for 1-3 days with chelated iron. These cells contained substantial amounts of the electrophoretically fast migrating ferritin, with its characteristic larger Stokes' radius (determined by quantitative polyacrylamide gel electrophoresis). None of the slow-migrating ferritin species was detected, although hindlimb muscle from iron-treated rats contained both forms. It is concluded that the fast-migrating ferritin of muscle, which is much larger and more asymmetric than other ferritins, is confined to the muscle cell population, while the other form is predominantly or exclusively in the non-muscle cells. Both ferritins are lost preferentially over other proteins during procedures which injure muscle tissue.

Primary skeletal muscle cells cultured on gelatin bead microcarriers develop structural and biochemical features characteristic of adult skeletal muscle.

Science.gov (United States)

Kubis, Hans-Peter; Scheibe, Renate J; Decker, Brigitte; Hufendiek, Karsten; Hanke, Nina; Gros, Gerolf; Meissner, Joachim D

2016-04-01

A primary skeletal muscle cell culture, in which myoblasts derived from newborn rabbit hindlimb muscles grow on gelatin bead microcarriers in suspension and differentiate into myotubes, has been established previously. In the course of differentiation and beginning spontaneous contractions, these multinucleated myotubes do not detach from their support. Here, we describe the development of the primary myotubes with respect to their ultrastructural differentiation. Scanning electron microscopy reveals that myotubes not only grow around the surface of one carrier bead but also attach themselves to neighboring carriers, forming bridges between carriers. Transmission electron microscopy demonstrates highly ordered myofibrils, T-tubules, and sarcoplasmic reticulum. The functionality of the contractile apparatus is evidenced by contractile activity that occurs spontaneously or can be elicited by electrostimulation. Creatine kinase activity increases steadily until day 20 of culture. Regarding the expression of isoforms of myosin heavy chains (MHC), we could demonstrate that from day 16 on, no non-adult MHC isoform mRNAs are present. Instead, on day 28 the myotubes express predominantly adult fast MHCIId/x mRNA and protein. This MHC pattern resembles that of fast muscles of adult rabbits. In contrast, primary myotubes grown on matrigel-covered culture dishes express substantial amounts of non-adult MHC protein even on day 21. To conclude, primary myotubes grown on microcarriers in their later stages exhibit many features of adult skeletal muscle and characteristics of fast type II fibers. Thus, the culture represents an excellent model of adult fast skeletal muscle, for example, when investigating molecular mechanisms of fast-to-slow fiber-type transformation. © 2015 International Federation for Cell Biology.

Transient receptor potential ankyrin 1 channel localized to non-neuronal airway cells promotes non-neurogenic inflammation

DEFF Research Database (Denmark)

Nassini, Romina; Pedretti, Pamela; Moretto, Nadia

2012-01-01

The transient receptor potential ankyrin 1 (TRPA1) channel, localized to airway sensory nerves, has been proposed to mediate airway inflammation evoked by allergen and cigarette smoke (CS) in rodents, via a neurogenic mechanism. However the limited clinical evidence for the role of neurogenic...... inflammation in asthma or chronic obstructive pulmonary disease raises an alternative possibility that airway inflammation is promoted by non-neuronal TRPA1.By using Real-Time PCR and calcium imaging, we found that cultured human airway cells, including fibroblasts, epithelial and smooth muscle cells express...... functional TRPA1 channels. By using immunohistochemistry, TRPA1 staining was observed in airway epithelial and smooth muscle cells in sections taken from human airways and lung, and from airways and lung of wild-type, but not TRPA1-deficient mice. In cultured human airway epithelial and smooth muscle cells...

Changes in myonuclear domain size do not precede muscle hypertrophy during prolonged resistance-type exercise training.

Science.gov (United States)

Snijders, T; Smeets, J S J; van Kranenburg, J; Kies, A K; van Loon, L J C; Verdijk, L B

2016-02-01

Muscle fibre hypertrophy is accompanied by an increase in myonuclear number, an increase in myonuclear domain size or both. It has been suggested that increases in myonuclear domain size precede myonuclear accretion and subsequent muscle fibre hypertrophy during prolonged exercise training. In this study, we assessed the changes in muscle fibre size, myonuclear and satellite cell content throughout 12 weeks of resistance-type exercise training in young men. Twenty-two young men (23 ± 1 year) were assigned to a progressive, 12-weeks resistance-type exercise training programme (3 sessions per week). Muscle biopsies from the vastus lateralis muscle were taken before and after 2, 4, 8 and 12 weeks of exercise training. Muscle fibre size, myonuclear content, myonuclear domain size and satellite cell content were assessed by immunohistochemistry. Type I and type II muscle fibre size increased gradually throughout the 12 weeks of training (type I: 18 ± 5%, type II: 41 ± 6%, P muscle fibres. No changes in type I and type II myonuclear domain size were observed at any time point throughout the intervention. Satellite cell content increased significantly over time in both type I and type II muscle fibres (P muscle fibre hypertrophy during prolonged resistance-type exercise training in vivo in humans. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

R-spondin1 Controls Muscle Cell Fusion through Dual Regulation of Antagonistic Wnt Signaling Pathways

Directory of Open Access Journals (Sweden)

Floriane Lacour

2017-03-01

Full Text Available Wnt-mediated signals are involved in many important steps in mammalian regeneration. In multiple cell types, the R-spondin (Rspo family of secreted proteins potently activates the canonical Wnt/β-catenin pathway. Here, we identify Rspo1 as a mediator of skeletal muscle tissue repair. First, we show that deletion of Rspo1 results in global alteration of muscle regeneration kinetics following acute injury. We find that muscle progenitor cells lacking Rspo1 show delayed differentiation due to reduced activation of Wnt/β-catenin target genes. Furthermore, muscle cells lacking Rspo1 have a fusion phenotype leading to larger myotubes containing supernumerary nuclei both in vitro and in vivo. The increase in muscle fusion was dependent on downregulation of Wnt/β-catenin and upregulation of non-canonical Wnt7a/Fzd7/Rac1 signaling. We conclude that reciprocal control of antagonistic Wnt signaling pathways by Rspo1 in muscle stem cell progeny is a key step ensuring normal tissue architecture restoration following acute damage.

Effect of neurturin on multipotent cells isolated from the adult skeletal muscle

International Nuclear Information System (INIS)

Vourc'h, Patrick; Lacar, Benjamin; Mignon, Laurence; Lucas, Paul A.; Young, Henry E.; Chesselet, Marie-Francoise

2005-01-01

Ligands of the glial cell line-derived neurotrophic factors (GDNF)-family are trophic factors for the development and survival of multiple cell types, however their effects on non-neuronal stem cells are unknown. We examined the action of neurturin on a candidate stem cell population isolated from adult skeletal muscles. When grown as spheres, these cells expressed mRNAs for GDNF, persephin, GFR-α2, GFR-α4 (neurturin receptor), and Ret. Exposure of these cells to neurturin significantly augmented cell numbers via increased cell proliferation. After addition of retinoic acid, the cells exited the cell cycle, developed thin processes, and became immunoreactive for βIII-tubulin, while Ret mRNA expression decreased, without changes in the level of GFR-α2 mRNA. Neurturin induced an outgrowth of processes on these βIII-tubulin positive cells. Neurturin may therefore be beneficial in the use of these multipotent cells isolated from adult muscles for autologous transplants in neurological applications

Potential of laryngeal muscle regeneration using induced pluripotent stem cell-derived skeletal muscle cells.

Science.gov (United States)

Dirja, Bayu Tirta; Yoshie, Susumu; Ikeda, Masakazu; Imaizumi, Mitsuyoshi; Nakamura, Ryosuke; Otsuki, Koshi; Nomoto, Yukio; Wada, Ikuo; Hazama, Akihiro; Omori, Koichi

2016-01-01

Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation.

The extraocular muscle stem cell niche is resistant to ageing and disease

Directory of Open Access Journals (Sweden)

Luigi eFormicola

2014-12-01

Full Text Available Specific muscles are spared in many degenerative myopathies. Most notably, the extraocular muscles (EOMs do not show clinical signs of late stage myopathies including the accumulation of fibrosis and fat. It has been proposed that an altered stem cell niche underlies the resistance of EOMs in these pathologies, however, to date, no reports have provided a detailed characterization of the EOM stem cell niche. PW1/Peg3 is expressed in progenitor cells in all adult tissues including satellite cells and a subset of interstitial non-satellite cell progenitors in muscle. These PW1-positive interstitial cells (PICs include a fibroadipogenic progenitor population (FAPs that give rise to fat and fibrosis in late stage myopathies. PICs/FAPs are mobilized following injury and FAPs exert a promyogenic role upon myoblasts in vitro but require the presence of a minimal population of satellite cells in vivo. We and others recently described that FAPs express promyogenic factors while satellite cells express antimyogenic factors suggesting that PICs/FAPs act as support niche cells in skeletal muscle through paracrine interactions. We analyzed the EOM stem cell niche in young adult and aged wild-type mice and found that the balance between PICs and satellite cells within the EOM stem cell niche is maintained throughout life. Moreover, in the adult mdx mouse model for Duchenne muscular dystrophy, the EOM stem cell niche is unperturbed compared to normal mice, in contrast to Tibialis Anterior (TA muscle, which displays signs of ongoing degeneration/regeneration. Regenerating mdx TA shows increased levels of both PICs and satellite cells, comparable to normal unaffected EOMs. We propose that the increase in PICs that we observe in normal EOMs contributes to preserving the integrity of the myofibers and satellite cells. Our data suggest that molecular cues regulating muscle regeneration are intrinsic properties of EOMs.

Composition of Muscle Fiber Types in Rat Rotator Cuff Muscles.

Science.gov (United States)

Rui, Yongjun; Pan, Feng; Mi, Jingyi

2016-10-01

The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow-twitch fibers, the majority of fast-twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles-related diseases. Anat Rec, 299:1397-1401, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Stretching human mesenchymal stromal cells on stiffness-customized collagen type I generates a smooth muscle marker profile without growth factor addition

Science.gov (United States)

Rothdiener, Miriam; Hegemann, Miriam; Uynuk-Ool, Tatiana; Walters, Brandan; Papugy, Piruntha; Nguyen, Phong; Claus, Valentin; Seeger, Tanja; Stoeckle, Ulrich; Boehme, Karen A.; Aicher, Wilhelm K.; Stegemann, Jan P.; Hart, Melanie L.; Kurz, Bodo; Klein, Gerd; Rolauffs, Bernd

2016-10-01

Using matrix elasticity and cyclic stretch have been investigated for inducing mesenchymal stromal cell (MSC) differentiation towards the smooth muscle cell (SMC) lineage but not in combination. We hypothesized that combining lineage-specific stiffness with cyclic stretch would result in a significantly increased expression of SMC markers, compared to non-stretched controls. First, we generated dense collagen type I sheets by mechanically compressing collagen hydrogels. Atomic force microscopy revealed a nanoscale stiffness range known to support myogenic differentiation. Further characterization revealed viscoelasticity and stable biomechanical properties under cyclic stretch with >99% viable adherent human MSC. MSCs on collagen sheets demonstrated a significantly increased mRNA but not protein expression of SMC markers, compared to on culture flasks. However, cyclic stretch of MSCs on collagen sheets significantly increased both mRNA and protein expression of α-smooth muscle actin, transgelin, and calponin versus plastic and non-stretched sheets. Thus, lineage-specific stiffness and cyclic stretch can be applied together for inducing MSC differentiation towards SMCs without the addition of recombinant growth factors or other soluble factors. This represents a novel stimulation method for modulating the phenotype of MSCs towards SMCs that could easily be incorporated into currently available methodologies to obtain a more targeted control of MSC phenotype.

Smooth muscle antibodies and type 1 autoimmune hepatitis.

Science.gov (United States)

Muratori, Paolo; Muratori, Luigi; Agostinelli, Daniela; Pappas, Georgios; Veronesi, Lorenza; Granito, Alessandro; Cassani, Fabio; Terlizzi, Paolo; Lenzi, Marco; Bianchi, Francesco B

2002-12-01

Smooth muscle antibodies (SMA) characterize type 1 autoimmune hepatitis. Our aim was to evaluate sensitivity and specificity of different immunofluorescence substrates for the detection of SMA. Sera from 55 patients with type 1 AIH 20 with primary biliary cirrhosis, 20 with HCV-related chronic hepatitis and 25 blood donors were studied for SMA and anti-microfilaments reactivity by immunofluorescence on rat tissue sections, cultured fibroblasts and commercially available HEp-2 cells (collectively revealing the so called anti-actin pattern), and for the XR1 system by counterimmunoelectrophoresis. SMA was classified on the basis of its immunofluorescence pattern (V--vessels, G--glomerular, T--tubular). As further control group, we studied 26 patients with a diagnosis other than AIH, selected on the basis of a SMA-non-T/XR1 positivity. In patients with AIH the SMA-T pattern on rodent tissue, and anti-MF on fibroblasts and on HEp-2 cells were present in 80, 82 and 80%, respectively. Five out of 11 SMA-non T positive AIH patients were anti-MF positive. None of the pathological and healthy controls was positive for SMA-T or anti-MF reactivity. XR1 system was present in 84% of AIH patients and in 5% of pathological controls (p = 0.01). Two out of 26 SMA-non-T/XR1 positive sera were positive for anti-MF by fibroblasts and HEp-2 cells. A significant correlation was found between SMA-T pattern and anti-MF reactivity; no correlation was found between XR1 system and SMA-T pattern or anti-MF reactivity. SMA-T pattern is highly sensitive and specific first diagnostic test for type 1 AIH; anti-MF can be used as additional tool for the diagnosis, particularly when, despite the absence of the SMA-T pattern, AIH is strongly suspected.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Somik [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yin, Hongshan [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Cardiovascular Medicine, Third Affiliated Hospital, Hebei Medical University, Shijiazhuang 050051, Hebei (China); Nam, Deokhwa [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Li, Yong [Department of Pediatric Surgery, Center for Stem Cell Research and Regenerative Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030 (United States); Ma, Ke, E-mail: kma@houstonmethodist.org [Center for Diabetes Research, Department of Medicine, Houston Methodist Research Institute, Houston, TX 77030 (United States)

2015-02-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1{sup −/−} mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation.

Brain and muscle Arnt-like 1 promotes skeletal muscle regeneration through satellite cell expansion

International Nuclear Information System (INIS)

Chatterjee, Somik; Yin, Hongshan; Nam, Deokhwa; Li, Yong; Ma, Ke

2015-01-01

Circadian clock is an evolutionarily conserved timing mechanism governing diverse biological processes and the skeletal muscle possesses intrinsic functional clocks. Interestingly, although the essential clock transcription activator, Brain and muscle Arnt-like 1 (Bmal1), participates in maintenance of muscle mass, little is known regarding its role in muscle growth and repair. In this report, we investigate the in vivo function of Bmal1 in skeletal muscle regeneration using two muscle injury models. Bmal1 is highly up-regulated by cardiotoxin injury, and its genetic ablation significantly impairs regeneration with markedly suppressed new myofiber formation and attenuated myogenic induction. A similarly defective regenerative response is observed in Bmal1-null mice as compared to wild-type controls upon freeze injury. Lack of satellite cell expansion accounts for the regeneration defect, as Bmal1 −/− mice display significantly lower satellite cell number with nearly abolished induction of the satellite cell marker, Pax7. Furthermore, satellite cell-derived primary myoblasts devoid of Bmal1 display reduced growth and proliferation ex vivo. Collectively, our results demonstrate, for the first time, that Bmal1 is an integral component of the pro-myogenic response that is required for muscle repair. This mechanism may underlie its role in preserving adult muscle mass and could be targeted therapeutically to prevent muscle-wasting diseases. - Highlights: • Bmal1 is highly inducible by muscle injury and myogenic stimuli. • Genetic ablation of Bmal1 significantly impairs muscle regeneration. • Bmal1 promotes satellite cell expansion during muscle regeneration. • Bmal1-deficient primary myoblasts display attenuated growth and proliferation

Bone marrow mesenchymal cells improve muscle function in a skeletal muscle re-injury model.

Directory of Open Access Journals (Sweden)

Bruno M Andrade

Full Text Available Skeletal muscle injury is the most common problem in orthopedic and sports medicine, and severe injury leads to fibrosis and muscle dysfunction. Conventional treatment for successive muscle injury is currently controversial, although new therapies, like cell therapy, seem to be promise. We developed a model of successive injuries in rat to evaluate the therapeutic potential of bone marrow mesenchymal cells (BMMC injected directly into the injured muscle. Functional and histological assays were performed 14 and 28 days after the injury protocol by isometric tension recording and picrosirius/Hematoxilin & Eosin staining, respectively. We also evaluated the presence and the fate of BMMC on treated muscles; and muscle fiber regeneration. BMMC treatment increased maximal skeletal muscle contraction 14 and 28 days after muscle injury compared to non-treated group (4.5 ± 1.7 vs 2.5 ± 0.98 N/cm2, p<0.05 and 8.4 ± 2.3 vs. 5.7 ± 1.3 N/cm2, p<0.05 respectively. Furthermore, BMMC treatment increased muscle fiber cross-sectional area and the presence of mature muscle fiber 28 days after muscle injury. However, there was no difference in collagen deposition between groups. Immunoassays for cytoskeleton markers of skeletal and smooth muscle cells revealed an apparent integration of the BMMC within the muscle. These data suggest that BMMC transplantation accelerates and improves muscle function recovery in our extensive muscle re-injury model.

Spot light on skeletal muscles: optogenetic stimulation to understand and restore skeletal muscle function.

Science.gov (United States)

van Bremen, Tobias; Send, Thorsten; Sasse, Philipp; Bruegmann, Tobias

2017-08-01

Damage of peripheral nerves results in paralysis of skeletal muscle. Currently, the only treatment option to restore proper function is electrical stimulation of the innervating nerve or of the skeletal muscles directly. However this approach has low spatial and temporal precision leading to co-activation of antagonistic muscles and lacks cell-type selectivity resulting in pain or discomfort by stimulation of sensible nerves. In contrast to electrical stimulation, optogenetic methods enable spatially confined and cell-type selective stimulation of cells expressing the light sensitive channel Channelrhodopsin-2 with precise temporal control over the membrane potential. Herein we summarize the current knowledge about the use of this technology to control skeletal muscle function with the focus on the direct, non-neuronal stimulation of muscle fibers. The high temporal flexibility of using light pulses allows new stimulation patterns to investigate skeletal muscle physiology. Furthermore, the high spatial precision of focused illumination was shown to be beneficial for selective stimulation of distinct nearby muscle groups. Finally, the cell-type specific expression of the light-sensitive effector proteins in muscle fibers will allow pain-free stimulation and open new options for clinical treatments. Therefore, we believe that direct optogenetic stimulation of skeletal muscles is a very potent method for basic scientists that also harbors several distinct advantages over electrical stimulation to be considered for clinical use in the future.

Impaired macrophage and satellite cell infiltration occurs in a muscle-specific fashion following injury in diabetic skeletal muscle.

Directory of Open Access Journals (Sweden)

Matthew P Krause

Full Text Available Systemic elevations in PAI-1 suppress the fibrinolytic pathway leading to poor collagen remodelling and delayed regeneration of tibialis anterior (TA muscles in type-1 diabetic Akita mice. However, how impaired collagen remodelling was specifically attenuating regeneration in Akita mice remained unknown. Furthermore, given intrinsic differences between muscle groups, it was unclear if the reparative responses between muscle groups were different.Here we reveal that diabetic Akita muscles display differential regenerative responses with the TA and gastrocnemius muscles exhibiting reduced regenerating myofiber area compared to wild-type mice, while soleus muscles displayed no difference between animal groups following injury. Collagen levels in TA and gastrocnemius, but not soleus, were significantly increased post-injury versus controls. At 5 days post-injury, when degenerating/necrotic regions were present in both animal groups, Akita TA and gastrocnemius muscles displayed reduced macrophage and satellite cell infiltration and poor myofiber formation. By 10 days post-injury, necrotic regions were absent in wild-type TA but persisted in Akita TA. In contrast, Akita soleus exhibited no impairment in any of these measures compared to wild-type soleus. In an effort to define how impaired collagen turnover was attenuating regeneration in Akita TA, a PAI-1 inhibitor (PAI-039 was orally administered to Akita mice following cardiotoxin injury. PAI-039 administration promoted macrophage and satellite cell infiltration into necrotic areas of the TA and gastrocnemius. Importantly, soleus muscles exhibit the highest inducible expression of MMP-9 following injury, providing a mechanism for normative collagen degradation and injury recovery in this muscle despite systemically elevated PAI-1.Our findings suggest the mechanism underlying how impaired collagen remodelling in type-1 diabetes results in delayed regeneration is an impairment in macrophage

An α-smooth muscle actin (acta2/αsma zebrafish transgenic line marking vascular mural cells and visceral smooth muscle cells.

Directory of Open Access Journals (Sweden)

Thomas R Whitesell

Full Text Available Mural cells of the vascular system include vascular smooth muscle cells (SMCs and pericytes whose role is to stabilize and/or provide contractility to blood vessels. One of the earliest markers of mural cell development in vertebrates is α smooth muscle actin (acta2; αsma, which is expressed by pericytes and SMCs. In vivo models of vascular mural cell development in zebrafish are currently lacking, therefore we developed two transgenic zebrafish lines driving expression of GFP or mCherry in acta2-expressing cells. These transgenic fish were used to trace the live development of mural cells in embryonic and larval transgenic zebrafish. acta2:EGFP transgenic animals show expression that largely mirrors native acta2 expression, with early pan-muscle expression starting at 24 hpf in the heart muscle, followed by skeletal and visceral muscle. At 3.5 dpf, expression in the bulbus arteriosus and ventral aorta marks the first expression in vascular smooth muscle. Over the next 10 days of development, the number of acta2:EGFP positive cells and the number of types of blood vessels associated with mural cells increases. Interestingly, the mural cells are not motile and remain in the same position once they express the acta2:EGFP transgene. Taken together, our data suggests that zebrafish mural cells develop relatively late, and have little mobility once they associate with vessels.

Structural Changes of Lumbar Muscles in Non-specific Low Back Pain: A Systematic Review.

Science.gov (United States)

Goubert, Dorien; Oosterwijck, Jessica Van; Meeus, Mira; Danneels, Lieven

2016-01-01

Lumbar muscle dysfunction due to pain might be related to altered lumbar muscle structure. Macroscopically, muscle degeneration in low back pain (LBP) is characterized by a decrease in cross-sectional area and an increase in fat infiltration in the lumbar paraspinal muscles. In addition microscopic changes, such as changes in fiber distribution, might occur. Inconsistencies in results from different studies make it difficult to draw firm conclusions on which structural changes are present in the different types of non-specific LBP. Insights regarding structural muscle alterations in LBP are, however, important for prevention and treatment of non-specific LBP. The goal of this article is to review which macro- and/or microscopic structural alterations of the lumbar muscles occur in case of non-specific chronic low back pain (CLBP), recurrent low back pain (RLBP), and acute low back pain (ALBP). Systematic review. All selected studies were case-control studies. A systematic literature search was conducted in the databases PubMed and Web of Science. Only full texts of original studies regarding structural alterations (atrophy, fat infiltration, and fiber type distribution) in lumbar muscles of patients with non-specific LBP compared to healthy controls were included. All included articles were scored on methodological quality. Fifteen studies were found eligible after screening title, abstract, and full text for inclusion and exclusion criteria. In CLBP, moderate evidence of atrophy was found in the multifidus; whereas, results in the paraspinal and the erector spinae muscle remain inconclusive. Also moderate evidence occurred in RLBP and ALBP, where no atrophy was shown in any lumbar muscle. Conflicting results were seen in undefined LBP groups. Results concerning fat infiltration were inconsistent in CLBP. On the other hand, there is moderate evidence in RLBP that fat infiltration does not occur, although a larger muscle fat index was found in the erector spinae

Expression of smooth muscle and non-muscle myosin heavy chain isoforms in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Rovner, A.S.; Murphy, R.A.; Owens, G.K.

1986-01-01

Immunocytochemical studies of cultured smooth muscle cells (SMCs) have disagreed on the nature of myosin expression. This investigation was undertaken to test for the presence of heterogeneous myosin heavy chain (MHC) isoforms in cell culture as a possible explanation for these results. Previously, Rovner et al. detected two MHCs in intact smooth muscles which differed in molecular weight by ca. 4000 daltons (SM1 and SM2) using a 3-4% acrylamide gradient SDS gel system. When sub-confluent primary cultures of rat aorta SMCs were assayed by this system, SM1 and SM2 were seen, along with large amounts of a third, unique MHC, NM, which closely resembled the MHC from human platelet in size and antigenicity. Data from 35 S-methionine autoradiograms showed that the log growth phase SMC cultures were producing almost exclusively NM, but the growth arrest, post-confluent cultures synthesized increased relative amounts of the SM MHC forms and contained comparable amounts of SM1, SM2, and NM. The same patterns of MHC synthesis were seen in sub-passaged SMCs. The expression of the SM-specific forms of myosin in quiescent, post-confluent cultures parallels that of smooth muscle actin suggesting that density induced growth arrest promotes cytodifferentiation in cultured vascular SMCs

Neuromuscular electrical stimulation as a method to maximize the beneficial effects of muscle stem cells transplanted into dystrophic skeletal muscle.

Directory of Open Access Journals (Sweden)

Giovanna Distefano

Full Text Available Cellular therapy is a potential approach to improve the regenerative capacity of damaged or diseased skeletal muscle. However, its clinical use has often been limited by impaired donor cell survival, proliferation and differentiation following transplantation. Additionally, functional improvements after transplantation are all-too-often negligible. Because the host microenvironment plays an important role in the fate of transplanted cells, methods to modulate the microenvironment and guide donor cell behavior are warranted. The purpose of this study was to investigate whether the use of neuromuscular electrical stimulation (NMES for 1 or 4 weeks following muscle-derived stem cell (MDSC transplantation into dystrophic skeletal muscle can modulate the fate of donor cells and enhance their contribution to muscle regeneration and functional improvements. Animals submitted to 4 weeks of NMES after transplantation demonstrated a 2-fold increase in the number of dystrophin+ myofibers as compared to control transplanted muscles. These findings were concomitant with an increased vascularity in the MDSC+NMES group when compared to non-stimulated counterparts. Additionally, animals subjected to NMES (with or without MDSC transplantation presented an increased maximal specific tetanic force when compared to controls. Although cell transplantation and/or the use of NMES resulted in no changes in fatigue resistance, the combination of both MDSC transplantation and NMES resulted in a faster recovery from fatigue, when compared to non-injected and non-stimulated counterparts. We conclude that NMES is a viable method to improve MDSC engraftment, enhance dystrophic muscle strength, and, in combination with MDSC transplantation, improve recovery from fatigue. These findings suggest that NMES may be a clinically-relevant adjunct approach for cell transplantation into skeletal muscle.

CD133+ cells derived from skeletal muscles of Duchenne muscular dystrophy patients have a compromised myogenic and muscle regenerative capability.

Science.gov (United States)

Meng, Jinhong; Muntoni, Francesco; Morgan, Jennifer

2018-05-12

Cell-mediated gene therapy is a possible means to treat muscular dystrophies like Duchenne muscular dystrophy. Autologous patient stem cells can be genetically-corrected and transplanted back into the patient, without causing immunorejection problems. Regenerated muscle fibres derived from these cells will express the missing dystrophin protein, thus improving muscle function. CD133+ cells derived from normal human skeletal muscle contribute to regenerated muscle fibres and form muscle stem cells after their intra-muscular transplantation into an immunodeficient mouse model. But it is not known whether CD133+ cells derived from DMD patient muscles have compromised muscle regenerative function. To test this, we compared CD133+ cells derived from DMD and normal human muscles. DMD CD133+ cells had a reduced capacity to undergo myogenic differentiation in vitro compared with CD133+ cells derived from normal muscle. In contrast to CD133+ cells derived from normal human muscle, those derived from DMD muscle formed no satellite cells and gave rise to significantly fewer muscle fibres of donor origin, after their intra-muscular transplantation into an immunodeficient, non-dystrophic, mouse muscle. DMD CD133+ cells gave rise to more clones of smaller size and more clones that were less myogenic than did CD133+ cells derived from normal muscle. The heterogeneity of the progeny of CD133+ cells, combined with the reduced proliferation and myogenicity of DMD compared to normal CD133+ cells, may explain the reduced regenerative capacity of DMD CD133+ cells. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Regulation of collagen biosynthesis in cultured bovine aortic smooth muscle cells

International Nuclear Information System (INIS)

Stepp, M.A.

1986-01-01

Aortic smooth muscles cells have been implicated in the etiology of lesions which occur in atherosclerosis and hypertension. Both diseases involve proliferation of smooth muscle cells and accumulation of excessive amounts of extracellular matrix proteins, including collagen type I and type III produced by the smooth muscle cells. To better understand the sites of regulation of collagen biosynthesis and to correlate these with the growth rate of the cells, cultured bovine aortic smooth muscle cells were studied as a function of the number of days (3 to 14) in second passage. Cells grew rapidly up to day 6 when confluence was reached. The total incorporation of [ 3 H]-proline into proteins was highest at day 3 and decreased to a constant level after the cultures reached confluence. In contrast, collagen protein production was lowest before confluence and continued to increase over the entire time course of the experiments. cDNA clones for the α1 and α2 chains of type I and the α1 chain of type III collagen were used to quantitate the steady state level of collagen mRNAs. RNA was tested in a cell-free translation system. Changes in the translational activity of collagen mRNAs parallelled the observed increases in collagen protein production. Thus, at later time points, collagen mRNAs are more active in directing synthesis of preprocollagens, even though less collagen mRNA is present. The conclusion is that the site of regulation of the expression of collagen genes is a function of the growth rate of cultured smooth muscle cells

Diabetic Myopathy: Impact of Diabetes Mellitus on Skeletal Muscle Progenitor Cells

Directory of Open Access Journals (Sweden)

Donna M D'Souza

2013-12-01

Full Text Available Diabetes mellitus is defined as a group of metabolic diseases that are associated with the presence of a hyperglycemic state due to impairments in insulin function. While the development of each form of diabetes (Type 1 or Type 2 drastically differs, resultant pathologies often overlap. In each diabetic condition a failure to maintain healthy muscle is often observed, and is termed diabetic myopathy. This significant, but often overlooked, complication is believed to contribute to the progression of additional diabetic pathologies due to the vital importance of skeletal muscle for our physical and metabolic well-being. While studies have investigated the link between changes to skeletal muscle metabolic health following diabetes mellitus onset (particularly Type 2 diabetes mellitus, few have examined the negative impact of diabetes mellitus on the growth and reparative capacities of skeletal muscle that often coincides with disease development. Importantly, evidence is accumulating that the muscle progenitor cell population (particularly the muscle satellite cell population is also negatively affected by the diabetic environment, and as such, likely contributes to the declining skeletal muscle health observed in diabetes mellitus. In this review, we summarize the current knowledge surrounding the influence of diabetes mellitus on skeletal muscle growth and repair, with a particular emphasis on the impact of diabetes mellitus on the progenitor cell population of skeletal muscle.

Human lung mast cells modulate the functions of airway smooth muscle cells in asthma.

Science.gov (United States)

Alkhouri, H; Hollins, F; Moir, L M; Brightling, C E; Armour, C L; Hughes, J M

2011-09-01

Activated mast cell densities are increased on the airway smooth muscle in asthma where they may modulate muscle functions and thus contribute to airway inflammation, remodelling and airflow obstruction. To determine the effects of human lung mast cells on the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Freshly isolated human lung mast cells were stimulated with IgE/anti-IgE. Culture supernatants were collected after 2 and 24 h and the mast cells lysed. The supernatants/lysates were added to serum-deprived, subconfluent airway smooth muscle cells for up to 48 h. Released chemokines and extracellular matrix were measured by ELISA, proliferation was quantified by [(3) H]-thymidine incorporation and cell counting, and intracellular signalling by phospho-arrays. Mast cell 2-h supernatants reduced CCL11 and increased CXCL8 and fibronectin production from both asthmatic and nonasthmatic muscle cells. Leupeptin reversed these effects. Mast cell 24-h supernatants and lysates reduced CCL11 release from both muscle cell types but increased CXCL8 release by nonasthmatic cells. The 24-h supernatants also reduced asthmatic, but not nonasthmatic, muscle cell DNA synthesis and asthmatic cell numbers over 5 days through inhibiting extracellular signal-regulated kinase (ERK) and phosphatidylinositol (PI3)-kinase pathways. However, prostaglandins, thromboxanes, IL-4 and IL-13 were not involved in reducing the proliferation. Mast cell proteases and newly synthesized products differentially modulated the secretory and proliferative functions of airway smooth muscle cells from donors with and without asthma. Thus, mast cells may modulate their own recruitment and airway smooth muscle functions locally in asthma. © 2011 John Wiley & Sons A/S.

Multipotent embryonic isl1+ progenitor cells lead to cardiac, smooth muscle, and endothelial cell diversification.

Science.gov (United States)

Moretti, Alessandra; Caron, Leslie; Nakano, Atsushi; Lam, Jason T; Bernshausen, Alexandra; Chen, Yinhong; Qyang, Yibing; Bu, Lei; Sasaki, Mika; Martin-Puig, Silvia; Sun, Yunfu; Evans, Sylvia M; Laugwitz, Karl-Ludwig; Chien, Kenneth R

2006-12-15

Cardiogenesis requires the generation of endothelial, cardiac, and smooth muscle cells, thought to arise from distinct embryonic precursors. We use genetic fate-mapping studies to document that isl1(+) precursors from the second heart field can generate each of these diverse cardiovascular cell types in vivo. Utilizing embryonic stem (ES) cells, we clonally amplified a cellular hierarchy of isl1(+) cardiovascular progenitors, which resemble the developmental precursors in the embryonic heart. The transcriptional signature of isl1(+)/Nkx2.5(+)/flk1(+) defines a multipotent cardiovascular progenitor, which can give rise to cells of all three lineages. These studies document a developmental paradigm for cardiogenesis, where muscle and endothelial lineage diversification arises from a single cell-level decision of a multipotent isl1(+) cardiovascular progenitor cell (MICP). The discovery of ES cell-derived MICPs suggests a strategy for cardiovascular tissue regeneration via their isolation, renewal, and directed differentiation into specific mature cardiac, pacemaker, smooth muscle, and endothelial cell types.

Voltage-dependent inward currents in smooth muscle cells of skeletal muscle arterioles

Science.gov (United States)

Shirokov, Roman E.

2018-01-01

Voltage-dependent inward currents responsible for the depolarizing phase of action potentials were characterized in smooth muscle cells of 4th order arterioles in mouse skeletal muscle. Currents through L-type Ca2+ channels were expected to be dominant; however, action potentials were not eliminated in nominally Ca2+-free bathing solution or by addition of L-type Ca2+ channel blocker nifedipine (10 μM). Instead, Na+ channel blocker tetrodotoxin (TTX, 1 μM) reduced the maximal velocity of the upstroke at low, but not at normal (2 mM), Ca2+ in the bath. The magnitude of TTX-sensitive currents recorded with 140 mM Na+ was about 20 pA/pF. TTX-sensitive currents decreased five-fold when Ca2+ increased from 2 to 10 mM. The currents reduced three-fold in the presence of 10 mM caffeine, but remained unaltered by 1 mM of isobutylmethylxanthine (IBMX). In addition to L-type Ca2+ currents (15 pA/pF in 20 mM Ca2+), we also found Ca2+ currents that are resistant to 10 μM nifedipine (5 pA/pF in 20 mM Ca2+). Based on their biophysical properties, these Ca2+ currents are likely to be through voltage-gated T-type Ca2+ channels. Our results suggest that Na+ and at least two types (T- and L-) of Ca2+ voltage-gated channels contribute to depolarization of smooth muscle cells in skeletal muscle arterioles. Voltage-gated Na+ channels appear to be under a tight control by Ca2+ signaling. PMID:29694371

Satellite Cells and the Muscle Stem Cell Niche

Science.gov (United States)

Yin, Hang; Price, Feodor

2013-01-01

Adult skeletal muscle in mammals is a stable tissue under normal circumstances but has remarkable ability to repair after injury. Skeletal muscle regeneration is a highly orchestrated process involving the activation of various cellular and molecular responses. As skeletal muscle stem cells, satellite cells play an indispensible role in this process. The self-renewing proliferation of satellite cells not only maintains the stem cell population but also provides numerous myogenic cells, which proliferate, differentiate, fuse, and lead to new myofiber formation and reconstitution of a functional contractile apparatus. The complex behavior of satellite cells during skeletal muscle regeneration is tightly regulated through the dynamic interplay between intrinsic factors within satellite cells and extrinsic factors constituting the muscle stem cell niche/microenvironment. For the last half century, the advance of molecular biology, cell biology, and genetics has greatly improved our understanding of skeletal muscle biology. Here, we review some recent advances, with focuses on functions of satellite cells and their niche during the process of skeletal muscle regeneration. PMID:23303905

Muscle satellite cells are activated after exercise to exhaustion in Thoroughbred horses.

Science.gov (United States)

Kawai, M; Aida, H; Hiraga, A; Miyata, H

2013-07-01

Although satellite cells are well known as muscle stem cells capable of adding myonuclei during muscle repair and hypertrophy, the response of satellite cells in horse muscles to a run to exhaustion is still unknown. To investigate the time course of satellite cell activation in Thoroughbred horse muscle after running to exhaustion. We hypothesised that this type of intense exercise would induce satellite cell activation in skeletal muscle similar to a resistance exercise. Nine de-trained Thoroughbred horses (6 geldings and 3 mares) aged 3-6 years were studied. Biopsy samples were taken from the gluteus medius muscle of the horses before and 1 min, 3 h, 1 day, 3 days, 1 week and 2 weeks after a treadmill run to exhaustion. The numbers of satellite cells for each fibre type were determined by using immunofluorescence staining. Total RNA was extracted from these samples, and the expressions of interleukin (IL)-6, paired box transcriptional factor (Pax) 7, myogenic differentiation 1 (MyoD), myogenin, proliferating cell nuclear antigen (PCNA), insulin-like growth factor (IGF)-I and hepatocyte growth factor (HGF) mRNA were analysed using real-time reverse transcription-PCR. The numbers of satellite cells were significantly increased in type I and IIa fibres at 1 week and in type IIa/x fibre at 2 weeks post exercise. The expression of IL-6 mRNA increased significantly by 3 h post exercise. The expression of PCNA mRNA also increased by 1 day after running, indicating that running can initiate satellite cell proliferation. The expression of Pax7, MyoD, myogenin, IGF-I and HGF mRNA peaked at 1 week post exercise. Satellite cell activation and proliferation could be enhanced after a run to exhaustion without detectable injury as assessed by the histochemical analysis. Understanding the response of satellite cell activation to running exercise provides fundamental information about the skeletal muscle adaptation in Thoroughbred horses. © 2012 EVJ Ltd.

Consequences of Late-Stage Non-Small-Cell Lung Cancer Cachexia on Muscle Metabolic Processes.

Science.gov (United States)

Murton, Andrew J; Maddocks, Matthew; Stephens, Francis B; Marimuthu, Kanagaraj; England, Ruth; Wilcock, Andrew

2017-01-01

The loss of muscle is common in patients with advanced non-small-cell lung cancer (NSCLC) and contributes to the high morbidity and mortality of this group. The exact mechanisms behind the muscle loss are unclear. To investigate this, 4 patients with stage IV NSCLC who met the clinical definitions for sarcopenia and cachexia were recruited, along with 4 age-matched healthy volunteers. After an overnight fast, biopsy specimens were obtained from the vastus lateralis, and the key components associated with inflammation and the control of muscle protein, carbohydrate, and fat metabolism were assessed. Compared with the healthy volunteers, significant increases in mRNA levels for interleukin-6 and NF-κB signaling and lower intramyocellular lipid content in slow-twitch fibers were observed in NSCLC patients. Although a significant decrease in phosphorylation of the mechanistic target of rapamycin (mTOR) signaling protein 4E-BP1 (Ser 65 ) was observed, along with a trend toward reduced p70 S6K (Thr 389 ) phosphorylation (P = .06), no difference was found between groups for the mRNA levels of MAFbx (muscle atrophy F box) and MuRF1 (muscle ring finger protein 1), chymotrypsin-like activity of the proteasome, or protein levels of multiple proteasome subunits. Moreover, despite decreases in intramyocellular lipid content, no robust changes in mRNA levels for key proteins involved in insulin signaling, glycolysis, oxidative metabolism, or fat metabolism were observed. These findings suggest that examining the contribution of suppressed mTOR signaling in the loss of muscle mass in late-stage NSCLC patients is warranted and reinforces our need to understand the potential contribution of impaired fat metabolism and muscle protein synthesis in the etiology of cancer cachexia. Copyright © 2016 Elsevier Inc. All rights reserved.

Identification of telocytes in skeletal muscle interstitium: implication for muscle regeneration.

Science.gov (United States)

Popescu, L M; Manole, Emilia; Serboiu, Crenguţa S; Manole, C G; Suciu, Laura C; Gherghiceanu, Mihaela; Popescu, B O

2011-06-01

Skeletal muscle interstitium is crucial for regulation of blood flow, passage of substances from capillaries to myocytes and muscle regeneration. We show here, probably, for the first time, the presence of telocytes (TCs), a peculiar type of interstitial (stromal) cells, in rat, mouse and human skeletal muscle. TC features include (as already described in other tissues) a small cell body and very long and thin cell prolongations-telopodes (Tps) with moniliform appearance, dichotomous branching and 3D-network distribution. Transmission electron microscopy (TEM) revealed close vicinity of Tps with nerve endings, capillaries, satellite cells and myocytes, suggesting a TC role in intercellular signalling (via shed vesicles or exosomes). In situ immunolabelling showed that skeletal muscle TCs express c-kit, caveolin-1 and secrete VEGF. The same phenotypic profile was demonstrated in cell cultures. These markers and TEM data differentiate TCs from both satellite cells (e.g. TCs are Pax7 negative) and fibroblasts (which are c-kit negative). We also described non-satellite (resident) progenitor cell niche. In culture, TCs (but not satellite cells) emerge from muscle explants and form networks suggesting a key role in muscle regeneration and repair, at least after trauma. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.

Protein Supplementation Augments Muscle Fiber Hypertrophy but Does Not Modulate Satellite Cell Content During Prolonged Resistance-Type Exercise Training in Frail Elderly.

Science.gov (United States)

Dirks, Marlou L; Tieland, Michael; Verdijk, Lex B; Losen, Mario; Nilwik, Rachel; Mensink, Marco; de Groot, Lisette C P G M; van Loon, Luc J C

2017-07-01

Protein supplementation increases gains in lean body mass following prolonged resistance-type exercise training in frail older adults. We assessed whether the greater increase in lean body mass can be attributed to muscle fiber type specific hypertrophy with concomitant changes in satellite cell (SC) content. A total of 34 frail elderly individuals (77 ± 1 years, n = 12 male adults) participated in this randomized, double-blind, placebo-controlled trial with 2 arms in parallel. Participants performed 24 weeks of progressive resistance-type exercise training (2 sessions per week) during which they were supplemented twice-daily with milk protein (2 × 15 g) or a placebo. Muscle biopsies were taken at baseline, and after 12 and 24 weeks of intervention, to determine type I and type II muscle fiber specific cross-sectional area (CSA), SC content, and myocellular characteristics. In the placebo group, a trend for a 20% ± 11% increase in muscle fiber CSA was observed in type II fibers only (P = .051), with no increase in type I muscle fiber CSA. In the protein group, type I and II muscle fiber CSA increased by 23% ± 7% and 34% ± 10% following 6 months of training, respectively (P  .05). No changes in myonuclear content and SC contents were observed over time in either group (both P > .05). Regression analysis showed that changes in myonuclear content and domain size are predictive of muscle fiber hypertrophy. Protein supplementation augments muscle fiber hypertrophy following prolonged resistance-type exercise training in frail older people, without changes in myonuclear and SC content. Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Glass promotes the differentiation of neuronal and non-neuronal cell types in the Drosophila eye

Science.gov (United States)

Morrison, Carolyn A.; Chen, Hao; Cook, Tiffany; Brown, Stuart

2018-01-01

Transcriptional regulators can specify different cell types from a pool of equivalent progenitors by activating distinct developmental programs. The Glass transcription factor is expressed in all progenitors in the developing Drosophila eye, and is maintained in both neuronal and non-neuronal cell types. Glass is required for neuronal progenitors to differentiate as photoreceptors, but its role in non-neuronal cone and pigment cells is unknown. To determine whether Glass activity is limited to neuronal lineages, we compared the effects of misexpressing it in neuroblasts of the larval brain and in epithelial cells of the wing disc. Glass activated overlapping but distinct sets of genes in these neuronal and non-neuronal contexts, including markers of photoreceptors, cone cells and pigment cells. Coexpression of other transcription factors such as Pax2, Eyes absent, Lozenge and Escargot enabled Glass to induce additional genes characteristic of the non-neuronal cell types. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. These results indicate that Glass is a determinant of organ identity that acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye. PMID:29324767

Nonparenchymal cells cultivated from explants of fibrotic liver resemble endothelial and smooth muscle cells from blood vessel walls

International Nuclear Information System (INIS)

Voss, B.; Rauterberg, J.; Pott, G.; Brehmer, U.; Allam, S.; Lehmann, R.; von Bassewitz, D.B.

1982-01-01

Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the endothelial cells, factor VIII-associated protein was demonstrated by indirect immunofluorescence. Synthesis of collagen types I and III, basement membrane collagen types IV and V, and fibronectin by both cell types was observed by immunofluorescence microscopy. Homogeneous cultures of smooth muscle cells were observed in subcultures. After incubation with [ 14 C]glycine, collagen was isolated and characterized by CM cellulose chromatography, and consisted mainly of types I and III. These data suggest involvement of mesenchymal cells in hepatic fibrosis; they presumably originate from blood vessel or sinusoidal walls

Vinpocetine Attenuates the Osteoblastic Differentiation of Vascular Smooth Muscle Cells.

Directory of Open Access Journals (Sweden)

Yun-Yun Ma

Full Text Available Vascular calcification is an active process of osteoblastic differentiation of vascular smooth muscle cells; however, its definite mechanism remains unknown. Vinpocetine, a derivative of the alkaloid vincamine, has been demonstrated to inhibit the high glucose-induced proliferation of vascular smooth muscle cells; however, it remains unknown whether vinpocetine can affect the osteoblastic differentiation of vascular smooth muscle cells. We hereby investigated the effect of vinpocetine on vascular calcification using a beta-glycerophosphate-induced cell model. Our results showed that vinpocetine significantly reduced the osteoblast-like phenotypes of vascular smooth muscle cells including ALP activity, osteocalcin, collagen type I, Runx2 and BMP-2 expression as well as the formation of mineralized nodule. Vinpocetine, binding to translocation protein, induced phosphorylation of extracellular signal-related kinase and Akt and thus inhibited the translocation of nuclear factor-kappa B into the nucleus. Silencing of translocator protein significantly attenuated the inhibitory effect of vinpocetine on osteoblastic differentiation of vascular smooth muscle cells. Taken together, vinpocetine may be a promising candidate for the clinical therapy of vascular calcification.

Muscle Satellite Cell Protein Teneurin‐4 Regulates Differentiation During Muscle Regeneration

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So‐ichiro; Okano, Hideyuki; Takeda, Shin'ichi

2015-01-01

Abstract Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin‐4 (Ten‐4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten‐4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten‐4‐deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten‐4‐deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten‐4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten‐4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. Stem Cells 2015;33:3017–3027 PMID:26013034

Muscle satellite cell heterogeneity and self-renewal

Science.gov (United States)

Motohashi, Norio; Asakura, Atsushi

2014-01-01

Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD) patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD. PMID:25364710

Muscle Satellite Cell Heterogeneity and Self-Renewal

Directory of Open Access Journals (Sweden)

Norio eMotohashi

2014-01-01

Full Text Available Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD.

Gene regulation mediating fiber-type transformation in skeletal muscle cells is partly glucose- and ChREBP-dependent.

Science.gov (United States)

Hanke, Nina; Scheibe, Renate J; Manukjan, Georgi; Ewers, David; Umeda, Patrick K; Chang, Kin-Chow; Kubis, Hans-Peter; Gros, Gerolf; Meissner, Joachim D

2011-03-01

Adaptations in the oxidative capacity of skeletal muscle cells can occur under several physiological or pathological conditions. We investigated the effect of increasing extracellular glucose concentration on the expression of markers of energy metabolism in primary skeletal muscle cells and the C2C12 muscle cell line. Growth of myotubes in 25mM glucose (high glucose, HG) compared with 5.55mM led to increases in the expression and activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a marker of glycolytic energy metabolism, while oxidative markers peroxisome proliferator-activated receptor γ coactivator 1α and citrate synthase decreased. HG induced metabolic adaptations as are seen during a slow-to-fast fiber transformation. Furthermore, HG increased fast myosin heavy chain (MHC) IId/x but did not change slow MHCI/β expression. Protein phosphatase 2A (PP2A) was shown to mediate the effects of HG on GAPDH and MHCIId/x. Carbohydrate response element-binding protein (ChREBP), a glucose-dependent transcription factor downstream of PP2A, partially mediated the effects of glucose on metabolic markers. The glucose-induced increase in PP2A activity was associated with an increase in p38 mitogen-activated protein kinase activity, which presumably mediates the increase in MHCIId/x promoter activity. Liver X receptor, another possible mediator of glucose effects, induced only an incomplete metabolic shift, mainly increasing the expression of the glycolytic marker. Taken together, HG induces a partial slow-to-fast transformation comprising metabolic enzymes together with an increased expression of MHCIId/x. This work demonstrates a functional role for ChREBP in determining the metabolic type of muscle fibers and highlights the importance of glucose as a signaling molecule in muscle. Copyright © 2011 Elsevier B.V. All rights reserved.

The role of tumor necrosis factor-α-related apoptosis-inducing ligand (TRAIL) in mediating autophagy in myositis skeletal muscle: A potential non-immune mechanism of muscle damage

Science.gov (United States)

Alger, Heather M.; Raben, Nina; Pistilli, Emidio; Francia, Dwight; Rawat, Rashmi; Getnet, Derese; Ghimbovschi, Svetlana; Chen, Yi-Wen; Lundberg, Ingrid E.; Nagaraju, Kanneboyina

2011-01-01

Objective Multinucleated cells are relatively resistant to classical apoptosis, and the factors initiating cell-death and damage in myositis are not well defined. We hypothesized that non-immune autophagic cell death may play a role in muscle fiber damage. Recent literature indicates that tumor necrosis factor-alpha-related apoptosis inducing ligand (TRAIL) may induce both NFκB (nuclear factor kappa-light chain enhancer of activated B cells) activation and autophagic cell death in other systems. Here, we have investigated its role in cell death and pathogenesis in vitro and in vivo using myositis (human and mouse) muscle tissues. Methods Gene expression profiling indicated that expression of TRAIL and several autophagy markers was specifically upregulated in myositis muscle tissue; these results were confirmed by immunohistochemistry and immunoblotting. We also analyzed TRAIL-induced cell death (apoptosis and autophagy) and NFκB activation in vitro in cultured cells. Results TRAIL was expressed predominantly in muscle fibers of myositis, but not in biopsies from normal or other dystrophic-diseased muscle. Autophagy markers were upregulated in human and mouse models of myositis. TRAIL expression was restricted to regenerating/atrophic areas of muscle fascicles, blood vessels, and infiltrating lymphocytes. TRAIL induced NFκB activation and IκB degradation in cultured cells that are resistant to TRAIL-induced apoptosis but undergo autophagic cell death. Conclusion Our data demonstrate that TRAIL is expressed in myositis muscle and may mediate both activation of NFκB and autophagic cell death in myositis. Thus, this non-immune pathway may be an attractive target for therapeutic intervention in myositis. PMID:21769834

Noninvasive pulsed focused ultrasound allows spatiotemporal control of targeted homing for multiple stem cell types in murine skeletal muscle and the magnitude of cell homing can be increased through repeated applications.

Science.gov (United States)

Burks, Scott R; Ziadloo, Ali; Kim, Saejeong J; Nguyen, Ben A; Frank, Joseph A

2013-11-01

Stem cells are promising therapeutics for cardiovascular diseases, and i.v. injection is the most desirable route of administration clinically. Subsequent homing of exogenous stem cells to pathological loci is frequently required for therapeutic efficacy and is mediated by chemoattractants (cell adhesion molecules, cytokines, and growth factors). Homing processes are inefficient and depend on short-lived pathological inflammation that limits the window of opportunity for cell injections. Noninvasive pulsed focused ultrasound (pFUS), which emphasizes mechanical ultrasound-tissue interactions, can be precisely targeted in the body and is a promising approach to target and maximize stem cell delivery by stimulating chemoattractant expression in pFUS-treated tissue prior to cell infusions. We demonstrate that pFUS is nondestructive to murine skeletal muscle tissue (no necrosis, hemorrhage, or muscle stem cell activation) and initiates a largely M2-type macrophage response. We also demonstrate that local upregulation of chemoattractants in pFUS-treated skeletal muscle leads to enhance homing, permeability, and retention of human mesenchymal stem cells (MSC) and human endothelial precursor cells (EPC). Furthermore, the magnitude of MSC or EPC homing was increased when pFUS treatments and cell infusions were repeated daily. This study demonstrates that pFUS defines transient "molecular zip codes" of elevated chemoattractants in targeted muscle tissue, which effectively provides spatiotemporal control and tunability of the homing process for multiple stem cell types. pFUS is a clinically translatable modality that may ultimately improve homing efficiency and flexibility of cell therapies for cardiovascular diseases. © AlphaMed Press.

Aging, metabolism and stem cells: Spotlight on muscle stem cells.

Science.gov (United States)

García-Prat, Laura; Muñoz-Cánoves, Pura

2017-04-15

All tissues and organs undergo a progressive regenerative decline as they age. This decline has been mainly attributed to loss of stem cell number and/or function, and both stem cell-intrinsic changes and alterations in local niches and/or systemic environment over time are known to contribute to the stem cell aging phenotype. Advancing in the molecular understanding of the deterioration of stem cell cells with aging is key for targeting the specific causes of tissue regenerative dysfunction at advanced stages of life. Here, we revise exciting recent findings on why stem cells age and the consequences on tissue regeneration, with a special focus on regeneration of skeletal muscle. We also highlight newly identified common molecular pathways affecting diverse types of aging stem cells, such as altered proteostasis, metabolism, or senescence entry, and discuss the questions raised by these findings. Finally, we comment on emerging stem cell rejuvenation strategies, principally emanating from studies on muscle stem cells, which will surely burst tissue regeneration research for future benefit of the increasing human aging population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Human induced pluripotent stem cell-derived vascular smooth muscle cells

DEFF Research Database (Denmark)

Ayoubi, Sohrab; Sheikh, Søren P; Eskildsen, Tilde V

2017-01-01

. To this end, human induced pluripotent stem cells (hiPSCs) have generated great enthusiasm, and have been a driving force for development of novel strategies in drug discovery and regenerative cell-therapy for the last decade. Hence, investigating the mechanisms underlying the differentiation of hi......PSCs into specialized cell types such as cardiomyocytes, endothelial cells, and vascular smooth muscle cells (VSMCs) may lead to a better understanding of developmental cardiovascular processes and potentiate progress of safe autologous regenerative therapies in pathological conditions. In this review, we summarize...

Muscle Satellite Cell Protein Teneurin-4 Regulates Differentiation During Muscle Regeneration.

Science.gov (United States)

Ishii, Kana; Suzuki, Nobuharu; Mabuchi, Yo; Ito, Naoki; Kikura, Naomi; Fukada, So-Ichiro; Okano, Hideyuki; Takeda, Shin'ichi; Akazawa, Chihiro

2015-10-01

Satellite cells are maintained in an undifferentiated quiescent state, but during muscle regeneration they acquire an activated stage, and initiate to proliferate and differentiate as myoblasts. The transmembrane protein teneurin-4 (Ten-4) is specifically expressed in the quiescent satellite cells; however, its cellular and molecular functions remain unknown. We therefore aimed to elucidate the function of Ten-4 in muscle satellite cells. In the tibialis anterior (TA) muscle of Ten-4-deficient mice, the number and the size of myofibers, as well as the population of satellite cells, were reduced with/without induction of muscle regeneration. Furthermore, we found an accelerated activation of satellite cells in the regenerated Ten-4-deficient TA muscle. The cell culture analysis using primary satellite cells showed that Ten-4 suppressed the progression of myogenic differentiation. Together, our findings revealed that Ten-4 functions as a crucial player in maintaining the quiescence of muscle satellite cells. © 2015 The Authors STEM CELLS published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

Differential expression of peroxisome proliferator activated receptor gamma and cyclin D1 does not affect proliferation of asthma- and non-asthma-derived airway smooth muscle cells

NARCIS (Netherlands)

Lau, Justine Y; Oliver, Brian G; Moir, Lyn M; Black, Judith L; Burgess, Janette K

UNLABELLED: PPARgamma levels in asthma- and non-asthma-derived airway smooth muscle cells and PPARgamma activation-induced cell proliferation were investigated. In the presence of FBS, PPARgamma levels were higher in subconfluent asthma-derived cells but lower in confluent cells compared with

Phenotype and Functional Features of Human Telomerase Reverse Transcriptase Immortalized Human Airway Smooth Muscle Cells from Asthmatic and Non-Asthmatic Donors

NARCIS (Netherlands)

Burgess, J. K.; Ketheson, A.; Faiz, A.; Rempel, K. A. Limbert; Oliver, B. G.; Ward, J. P. T.; Halayko, A. J.

2018-01-01

Asthma is an obstructive respiratory disease characterised by chronic inflammation with airway hyperresponsiveness. In asthmatic airways, there is an increase in airway smooth muscle (ASM) cell bulk, which differs from non-asthmatic ASM in characteristics. This study aimed to assess the usefulness

The Skeletal Muscle Satellite Cell

Science.gov (United States)

2011-01-01

The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

Plasticity of the Muscle Stem Cell Microenvironment.

Science.gov (United States)

Dinulovic, Ivana; Furrer, Regula; Handschin, Christoph

2017-01-01

Satellite cells (SCs) are adult muscle stem cells capable of repairing damaged and creating new muscle tissue throughout life. Their functionality is tightly controlled by a microenvironment composed of a wide variety of factors, such as numerous secreted molecules and different cell types, including blood vessels, oxygen, hormones, motor neurons, immune cells, cytokines, fibroblasts, growth factors, myofibers, myofiber metabolism, the extracellular matrix and tissue stiffness. This complex niche controls SC biology-quiescence, activation, proliferation, differentiation or renewal and return to quiescence. In this review, we attempt to give a brief overview of the most important players in the niche and their mutual interaction with SCs. We address the importance of the niche to SC behavior under physiological and pathological conditions, and finally survey the significance of an artificial niche both for basic and translational research purposes.

Skeletal Muscle Satellite Cells Are Committed to Myogenesis and Do Not Spontaneously Adopt Nonmyogenic Fates

Science.gov (United States)

Starkey, Jessica D.; Yamamoto, Masakazu; Yamamoto, Shoko; Goldhamer, David J.

2011-01-01

The developmental potential of skeletal muscle stem cells (satellite cells) remains controversial. The authors investigated satellite cell developmental potential in single fiber and clonal cultures derived from MyoDiCre/+;R26REYFP/+ muscle, in which essentially all satellite cells are permanently labeled. Approximately 60% of the clones derived from cells that co-purified with muscle fibers spontaneously underwent adipogenic differentiation. These adipocytes stained with Oil-Red-O and expressed the terminal differentiation markers, adipsin and fatty acid binding protein 4, but did not express EYFP and were therefore not of satellite cell origin. Satellite cells mutant for either MyoD or Myf-5 also maintained myogenic programming in culture and did not adopt an adipogenic fate. Incorporation of additional wash steps prior to muscle fiber plating virtually eliminated the non-myogenic cells but did not reduce the number of adherent Pax7+ satellite cells. More than half of the adipocytes observed in cultures from Tie2-Cre mice were recombined, further demonstrating a non-satellite cell origin. Under adipogenesis-inducing conditions, satellite cells accumulated cytoplasmic lipid but maintained myogenic protein expression and did not fully execute the adipogenic differentiation program, distinguishing them from adipocytes observed in muscle fiber cultures. The authors conclude that skeletal muscle satellite cells are committed to myogenesis and do not spontaneously adopt an adipogenic fate. PMID:21339173

Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models

Science.gov (United States)

Marquette, Michele L.; Sognier, Marguerite A.

2013-01-01

An improved method for culturing immature muscle cells (myoblasts) into a mature skeletal muscle overcomes some of the notable limitations of prior culture methods. The development of the method is a major advance in tissue engineering in that, for the first time, a cell-based model spontaneously fuses and differentiates into masses of highly aligned, contracting myotubes. This method enables (1) the construction of improved two-dimensional (monolayer) skeletal muscle test beds; (2) development of contracting three-dimensional tissue models; and (3) improved transplantable tissues for biomedical and regenerative medicine applications. With adaptation, this method also offers potential application for production of other tissue types (i.e., bone and cardiac) from corresponding precursor cells.

Smooth Muscle-Like Cells Generated from Human Mesenchymal Stromal Cells Display Marker Gene Expression and Electrophysiological Competence Comparable to Bladder Smooth Muscle Cells.

Science.gov (United States)

Brun, Juliane; Lutz, Katrin A; Neumayer, Katharina M H; Klein, Gerd; Seeger, Tanja; Uynuk-Ool, Tatiana; Wörgötter, Katharina; Schmid, Sandra; Kraushaar, Udo; Guenther, Elke; Rolauffs, Bernd; Aicher, Wilhelm K; Hart, Melanie L

2015-01-01

The use of mesenchymal stromal cells (MSCs) differentiated toward a smooth muscle cell (SMC) phenotype may provide an alternative for investigators interested in regenerating urinary tract organs such as the bladder where autologous smooth muscle cells cannot be used or are unavailable. In this study we measured the effects of good manufacturing practice (GMP)-compliant expansion followed by myogenic differentiation of human MSCs on the expression of a range of contractile (from early to late) myogenic markers in relation to the electrophysiological parameters to assess the functional role of the differentiated MSCs and found that differentiation of MSCs associated with electrophysiological competence comparable to bladder SMCs. Within 1-2 weeks of myogenic differentiation, differentiating MSCs significantly expressed alpha smooth muscle actin (αSMA; ACTA2), transgelin (TAGLN), calponin (CNN1), and smooth muscle myosin heavy chain (SM-MHC; MYH11) according to qRT-PCR and/or immunofluorescence and Western blot. Voltage-gated Na+ current levels also increased within the same time period following myogenic differentiation. In contrast to undifferentiated MSCs, differentiated MSCs and bladder SMCs exhibited elevated cytosolic Ca2+ transients in response to K+-induced depolarization and contracted in response to K+ indicating functional maturation of differentiated MSCs. Depolarization was suppressed by Cd2+, an inhibitor of voltage-gated Ca2+-channels. The expression of Na+-channels was pharmacologically identified as the Nav1.4 subtype, while the K+ and Ca2+ ion channels were identified by gene expression of KCNMA1, CACNA1C and CACNA1H which encode for the large conductance Ca2+-activated K+ channel BKCa channels, Cav1.2 L-type Ca2+ channels and Cav3.2 T-type Ca2+ channels, respectively. This protocol may be used to differentiate adult MSCs into smooth muscle-like cells with an intermediate-to-late SMC contractile phenotype exhibiting voltage-gated ion channel

Smooth Muscle-Like Cells Generated from Human Mesenchymal Stromal Cells Display Marker Gene Expression and Electrophysiological Competence Comparable to Bladder Smooth Muscle Cells.

Directory of Open Access Journals (Sweden)

Juliane Brun

Full Text Available The use of mesenchymal stromal cells (MSCs differentiated toward a smooth muscle cell (SMC phenotype may provide an alternative for investigators interested in regenerating urinary tract organs such as the bladder where autologous smooth muscle cells cannot be used or are unavailable. In this study we measured the effects of good manufacturing practice (GMP-compliant expansion followed by myogenic differentiation of human MSCs on the expression of a range of contractile (from early to late myogenic markers in relation to the electrophysiological parameters to assess the functional role of the differentiated MSCs and found that differentiation of MSCs associated with electrophysiological competence comparable to bladder SMCs. Within 1-2 weeks of myogenic differentiation, differentiating MSCs significantly expressed alpha smooth muscle actin (αSMA; ACTA2, transgelin (TAGLN, calponin (CNN1, and smooth muscle myosin heavy chain (SM-MHC; MYH11 according to qRT-PCR and/or immunofluorescence and Western blot. Voltage-gated Na+ current levels also increased within the same time period following myogenic differentiation. In contrast to undifferentiated MSCs, differentiated MSCs and bladder SMCs exhibited elevated cytosolic Ca2+ transients in response to K+-induced depolarization and contracted in response to K+ indicating functional maturation of differentiated MSCs. Depolarization was suppressed by Cd2+, an inhibitor of voltage-gated Ca2+-channels. The expression of Na+-channels was pharmacologically identified as the Nav1.4 subtype, while the K+ and Ca2+ ion channels were identified by gene expression of KCNMA1, CACNA1C and CACNA1H which encode for the large conductance Ca2+-activated K+ channel BKCa channels, Cav1.2 L-type Ca2+ channels and Cav3.2 T-type Ca2+ channels, respectively. This protocol may be used to differentiate adult MSCs into smooth muscle-like cells with an intermediate-to-late SMC contractile phenotype exhibiting voltage-gated ion

Comparative Statistical Mechanics of Muscle and Non-Muscle Contractile Systems: Stationary States of Near-Equilibrium Systems in A Linear Regime

Directory of Open Access Journals (Sweden)

Yves Lecarpentier

2017-10-01

Full Text Available A. Huxley’s equations were used to determine the mechanical properties of muscle myosin II (MII at the molecular level, as well as the probability of the occurrence of the different stages in the actin–myosin cycle. It was then possible to use the formalism of statistical mechanics with the grand canonical ensemble to calculate numerous thermodynamic parameters such as entropy, internal energy, affinity, thermodynamic flow, thermodynamic force, and entropy production rate. This allows us to compare the thermodynamic parameters of a non-muscle contractile system, such as the normal human placenta, with those of different striated skeletal muscles (soleus and extensor digitalis longus as well as the heart muscle and smooth muscles (trachea and uterus in the rat. In the human placental tissues, it was observed that the kinetics of the actin–myosin crossbridges were considerably slow compared with those of smooth and striated muscular systems. The entropy production rate was also particularly low in the human placental tissues, as compared with that observed in smooth and striated muscular systems. This is partly due to the low thermodynamic flow found in the human placental tissues. However, the unitary force of non-muscle myosin (NMII generated by each crossbridge cycle in the myofibroblasts of the human placental tissues was similar in magnitude to that of MII in the myocytes of both smooth and striated muscle cells. Statistical mechanics represents a powerful tool for studying the thermodynamics of all contractile muscle and non-muscle systems.

Human skeletal muscle-derived stem cells retain stem cell properties after expansion in myosphere culture

International Nuclear Information System (INIS)

Wei, Yan; Li, Yuan; Chen, Chao; Stoelzel, Katharina; Kaufmann, Andreas M.; Albers, Andreas E.

2011-01-01

Human skeletal muscle contains an accessible adult stem-cell compartment in which differentiated myofibers are maintained and replaced by a self-renewing stem cell pool. Previously, studies using mouse models have established a critical role for resident stem cells in skeletal muscle, but little is known about this paradigm in human muscle. Here, we report the reproducible isolation of a population of cells from human skeletal muscle that is able to proliferate for extended periods of time as floating clusters of rounded cells, termed 'myospheres' or myosphere-derived progenitor cells (MDPCs). The phenotypic characteristics and functional properties of these cells were determined using reverse transcription-polymerase chain reaction (RT-PCR), flow cytometry and immunocytochemistry. Our results showed that these cells are clonogenic, express skeletal progenitor cell markers Pax7, ALDH1, Myod, and Desmin and the stem cell markers Nanog, Sox2, and Oct3/4 significantly elevated over controls. They could be maintained proliferatively active in vitro for more than 20 weeks and passaged at least 18 times, despite an average donor-age of 63 years. Individual clones (4.2%) derived from single cells were successfully expanded showing clonogenic potential and sustained proliferation of a subpopulation in the myospheres. Myosphere-derived cells were capable of spontaneous differentiation into myotubes in differentiation media and into other mesodermal cell lineages in induction media. We demonstrate here that direct culture and expansion of stem cells from human skeletal muscle is straightforward and reproducible with the appropriate technique. These cells may provide a viable resource of adult stem cells for future therapies of disease affecting skeletal muscle or mesenchymal lineage derived cell types.

A Dominant-Negative PPARγ Mutant Promotes Cell Cycle Progression and Cell Growth in Vascular Smooth Muscle Cells

Directory of Open Access Journals (Sweden)

Joey Z. Liu

2009-01-01

Full Text Available PPARγ ligands have been shown to have antiproliferative effects on many cell types. We herein report that a synthetic dominant-negative (DN PPARγ mutant functions like a growth factor to promote cell cycle progression and cell proliferation in human coronary artery smooth muscle cells (CASMCs. In quiescent CASMCs, adenovirus-expressed DN-PPARγ promoted G1→S cell cycle progression, enhanced BrdU incorporation, and increased cell proliferation. DN-PPARγ expression also markedly enhanced positive regulators of the cell cycle, increasing Rb and CDC2 phosphorylation and the expression of cyclin A, B1, D1, and MCM7. Conversely, overexpression of wild-type (WT or constitutively-active (CA PPARγ inhibited cell cycle progression and the activity and expression of positive regulators of the cell cycle. DN-PPARγ expression, however, did not up-regulate positive cell cycle regulators in PPARγ-deficient cells, strongly suggesting that DN-PPARγ effects on cell cycle result from blocking the function of endogenous wild-type PPARγ. DN-PPARγ expression enhanced phosphorylation of ERK MAPKs. Furthermore, the ERK specific-inhibitor PD98059 blocked DN-PPARγ-induced phosphorylation of Rb and expression of cyclin A and MCM7. Our data thus suggest that DN-PPARγ promotes cell cycle progression and cell growth in CASMCs by modulating fundamental cell cycle regulatory proteins and MAPK mitogenic signaling pathways in vascular smooth muscle cells (VSMCs.

Satellite cells in human skeletal muscle plasticity

Directory of Open Access Journals (Sweden)

Tim eSnijders

2015-10-01

Full Text Available Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodelling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodelling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodelling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

Satellite cells in human skeletal muscle plasticity.

Science.gov (United States)

Snijders, Tim; Nederveen, Joshua P; McKay, Bryon R; Joanisse, Sophie; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

2015-01-01

Skeletal muscle satellite cells are considered to play a crucial role in muscle fiber maintenance, repair and remodeling. Our knowledge of the role of satellite cells in muscle fiber adaptation has traditionally relied on in vitro cell and in vivo animal models. Over the past decade, a genuine effort has been made to translate these results to humans under physiological conditions. Findings from in vivo human studies suggest that satellite cells play a key role in skeletal muscle fiber repair/remodeling in response to exercise. Mounting evidence indicates that aging has a profound impact on the regulation of satellite cells in human skeletal muscle. Yet, the precise role of satellite cells in the development of muscle fiber atrophy with age remains unresolved. This review seeks to integrate recent results from in vivo human studies on satellite cell function in muscle fiber repair/remodeling in the wider context of satellite cell biology whose literature is largely based on animal and cell models.

Regulatory T cells and skeletal muscle regeneration.

Science.gov (United States)

Schiaffino, Stefano; Pereira, Marcelo G; Ciciliot, Stefano; Rovere-Querini, Patrizia

2017-02-01

Skeletal muscle regeneration results from the activation and differentiation of myogenic stem cells, called satellite cells, located beneath the basal lamina of the muscle fibers. Inflammatory and immune cells have a crucial role in the regeneration process. Acute muscle injury causes an immediate transient wave of neutrophils followed by a more persistent infiltration of M1 (proinflammatory) and M2 (anti-inflammatory/proregenerative) macrophages. New studies show that injured muscle is also infiltrated by a specialized population of regulatory T (Treg) cells, which control both the inflammatory response, by promoting the M1-to-M2 switch, and the activation of satellite cells. Treg cells accumulate in injured muscle in response to specific cytokines, such as IL-33, and promote muscle growth by releasing growth factors, such as amphiregulin. Muscle repair during aging is impaired due to reduced number of Treg cells and can be enhanced by IL-33 supplementation. Migration of Treg cells could also contribute to explain the effect of heterochronic parabiosis, whereby muscle regeneration of aged mice can be improved by a parabiotically linked young partners. In mdx dystrophin-deficient mice, a model of human Duchenne muscular dystrophy, muscle injury, and inflammation is mitigated by expansion of the Treg-cell population but exacerbated by Treg-cell depletion. These findings support the notion that immunological mechanisms are not only essential in the response to pathogenic microbes and tumor cells but also have a wider homeostatic role in tissue repair, and open new perspectives for boosting muscle growth in chronic muscle disease and during aging. © 2016 Federation of European Biochemical Societies.

Diseased muscles that lack dystrophin or laminin-α2 have altered compositions and proliferation of mononuclear cell populations

Directory of Open Access Journals (Sweden)

Miller Jeffrey

2005-04-01

Full Text Available Abstract Background Multiple types of mononucleate cells reside among the multinucleate myofibers in skeletal muscles and these mononucleate cells function in muscle maintenance and repair. How neuromuscular disease might affect different types of muscle mononucleate cells had not been determined. In this study, therefore, we examined how two neuromuscular diseases, dystrophin-deficiency and laminin-α2-deficiency, altered the proliferation and composition of different subsets of muscle-derived mononucleate cells. Methods We used fluorescence-activated cell sorting combined with bromodeoxyuridine labeling to examine proliferation rates and compositions of mononuclear cells in diseased and healthy mouse skeletal muscle. We prepared mononucleate cells from muscles of mdx (dystrophin-deficient or Lama2-/- (laminin-α2-deficient mice and compared them to cells from healthy control muscles. We enumerated subsets of resident muscle cells based on Sca-1 and CD45 expression patterns and determined the proliferation of each cell subset in vivo by BrdU incorporation. Results We found that the proliferation and composition of the mononucleate cells in dystrophin-deficient and laminin-α2-deficient diseased muscles are different than in healthy muscle. The mdx and Lama2-/- muscles showed similar significant increases in CD45+ cells compared to healthy muscle. Changes in proliferation, however, differed between the two diseases with proliferation increased in mdx and decreased in Lama2-/- muscles compared to healthy muscles. In particular, the most abundant Sca-1-/CD45- subset, which contains muscle precursor cells, had increased proliferation in mdx muscle but decreased proliferation in Lama2-/- muscles. Conclusion The similar increases in CD45+ cells, but opposite changes in proliferation of muscle precursor cells, may underlie aspects of the distinct pathologies in the two diseases.

Goat activin receptor type IIB knockdown by muscle specific promoter driven artificial microRNAs.

Science.gov (United States)

Patel, Amrutlal K; Shah, Ravi K; Patel, Utsav A; Tripathi, Ajai K; Joshi, Chaitanya G

2014-10-10

Activin receptor type IIB (ACVR2B) is a transmembrane receptor which mediates signaling of TGF beta superfamily ligands known to function in regulation of muscle mass, embryonic development and reproduction. ACVR2B antagonism has shown to enhance the muscle growth in several disease and transgenic models. Here, we show ACVR2B knockdown by RNA interference using muscle creatine kinase (MCK) promoter driven artificial microRNAs (amiRNAs). Among the various promoter elements tested, the ∼1.26 kb MCK promoter region showed maximum transcriptional activity in goat myoblasts cells. We observed up to 20% silencing in non-myogenic 293T cells and up to 32% silencing in myogenic goat myoblasts by MCK directed amiRNAs by transient transfection. Goat myoblasts stably integrated with MCK directed amiRNAs showed merely 8% silencing in proliferating myoblasts which was increased to 34% upon induction of differentiation at transcript level whereas up to 57% silencing at protein level. Knockdown of ACVR2B by 5'-UTR derived amiRNAs resulted in decreased SMAD2/3 signaling, increased expression of myogenic regulatory factors (MRFs) and enhanced proliferation and differentiation of myoblasts. Unexpectedly, knockdown of ACVR2B by 3'-UTR derived amiRNAs resulted in increased SMAD2/3 signaling, reduced expression of MRFs and suppression of myogenesis. Our study offers muscle specific knockdown of ACVR2B as a potential strategy to enhance muscle mass in the farm animal species. Copyright © 2014 Elsevier B.V. All rights reserved.

Glucose intolerance in the West African Diaspora: a skeletal muscle fibre type distribution hypothesis.

Science.gov (United States)

Nielsen, J; Christensen, D L

2011-08-01

In the United States, Black Americans are largely descendants of West African slaves; they have a higher relative proportion of obesity and experience a higher prevalence of diabetes than White Americans. However, obesity rates alone cannot explain the higher prevalence of type 2 diabetes. Type 2 diabetes is characterized by insulin resistance and beta-cell dysfunction. We hypothesize that the higher prevalence of type 2 diabetes in African Americans (as compared to White Americans) is facilitated by an inherited higher percentage of skeletal muscle fibre type II and a lower percentage of skeletal muscle fibre type I. Skeletal muscle fibre type II is less oxidative and more glycolytic than skeletal muscle fibre type I. Lower oxidative capacity is associated with lower fat oxidation and a higher disposal of lipids, which are stored as muscular adipose tissue in higher amounts in Black compared to White Americans. In physically active individuals, the influence of muscle fibre composition will not be as detrimental as in physically inactive individuals. This discrepancy is caused by the plasticity in the skeletal muscle fibre characteristics towards a higher activity of oxidative enzymes as a consequence of physical activity. We suggest that a higher percentage of skeletal muscle fibre type II combined with physical inactivity has an impact on insulin sensitivity and high prevalence of type 2 diabetes in Blacks of West African ancestry. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.

Oral Gingival Cell Cigarette Smoke Exposure Induces Muscle Cell Metabolic Disruption

Directory of Open Access Journals (Sweden)

Andrea C. Baeder

2016-01-01

Full Text Available Cigarette smoke exposure compromises health through damaging multiple physiological systems, including disrupting metabolic function. The purpose of this study was to determine the role of oral gingiva in mediating the deleterious metabolic effects of cigarette smoke exposure on skeletal muscle metabolic function. Using an in vitro conditioned medium cell model, skeletal muscle cells were incubated with medium from gingival cells treated with normal medium or medium containing suspended cigarette smoke extract (CSE. Following incubation of muscle cells with gingival cell conditioned medium, muscle cell mitochondrial respiration and insulin signaling and action were determined as an indication of overall muscle metabolic health. Skeletal muscle cells incubated with conditioned medium of CSE-treated gingival cells had a profound reduction in mitochondrial respiration and respiratory control. Furthermore, skeletal muscle cells had a greatly reduced response in insulin-stimulated Akt phosphorylation and glycogen synthesis. Altogether, these results provide a novel perspective on the mechanism whereby cigarette smoke affects systemic metabolic function. In conclusion, we found that oral gingival cells treated with CSE create an altered milieu that is sufficient to both disrupted skeletal muscle cell mitochondrial function and insulin sensitivity.

Different β-adrenergic receptor density in different rat skeletal muscle fibre types

International Nuclear Information System (INIS)

Jensen, J.; Dahl, H.A.; Broers, O.

1995-01-01

The effects of adrenaline on skeletal muscle differ between fibre types. The aim of the present study was to investigate the β-adrenoceptor density, affinity and subtype in rat skeletal muscles with different fibre type composition. β-Adrenoceptors were determined in cryostat sections to avoid methodological problems with variable recovery, using the non-selective βadrenoceptor ligand [ 3 H]CGP-12177 and β 1 - and β 2 -selective cold ligands CGP 20712A and ICI 118,551. In the presence of protease inhibitors [ 3 H]CGP-12177 binding was stable, saturable, reversible, and displaceable. Scatchard analysis of binding saturation data was compatible with a single class of specific binding sites. Binding site density (B max ) was higher (P -1 ) than in adult extensor digitorum longus (4.74±0.39 fmol x mg protein -1 ), whereas the dissociation constants (K d ), 0.37±0.05 and 0.31±0.04 nM for soleus and extensor digitorum longus, respectively, were not significantly different. For young rats (5-6 weeks), B max was 11.21±0.33 and 5.45±0.11 fmol x mg protein -1 (P d was 0.27±0.02 and 0.24±0.04 nM for soleus and epitrochlearis, respectively. These results correspond to a receptor density of 2 and 1 pmol x g w.wt. -1 in muscles containing mainly type I and type II fibres, respectively. Displacement studies with CGP 20712A and ICI 118,551 were compatible with mainly β 2 -adrenoceptors, but 7-10% β 1 -adrenoceptors were present in both types of muscle. In conclusion, the receptor density is twice as high in muscles containing mainly type I muscle fibres compared to muscles containing mainly type II fibres, and this may explain some of the different effects of adrenaline between the two muscle fibre types. (au)

The role of satellite cells in muscle hypertrophy.

Science.gov (United States)

Blaauw, Bert; Reggiani, Carlo

2014-02-01

The role of satellite cells in muscle hypertrophy has long been a debated issue. In the late 1980s it was shown that proteins remain close to the myonucleus responsible for its synthesis, giving rise to the idea of a nuclear domain. This, together with the observation that during various models of muscle hypertrophy there is an activation of the muscle stem cells, i.e. satellite cells, lead to the idea that satellite cell activation is required for muscle hypertrophy. Thus, satellite cells are not only responsible for muscle repair and regeneration, but also for hypertrophic growth. Further support for this line of thinking was obtained after studies showing that irradiation of skeletal muscle, and therefore elimination of all satellite cells, completely prevented overload-induced hypertrophy. Recently however, using different transgenic approaches, it has become clear that muscle hypertrophy can occur without a contribution of satellite cells, even though in most situations of muscle hypertrophy satellite cells are activated. In this review we will discuss the contribution of satellite cells, and other muscle-resident stem cells, to muscle hypertrophy both in mice as well as in humans.

Inducible satellite cell depletion attenuates skeletal muscle regrowth following a scald-burn injury.

Science.gov (United States)

Finnerty, Celeste C; McKenna, Colleen F; Cambias, Lauren A; Brightwell, Camille R; Prasai, Anesh; Wang, Ye; El Ayadi, Amina; Herndon, David N; Suman, Oscar E; Fry, Christopher S

2017-11-01

Severe burns result in significant skeletal muscle cachexia that impedes recovery. Activity of satellite cells, skeletal muscle stem cells, is altered following a burn injury and likely hinders regrowth of muscle. Severe burn injury induces satellite cell proliferation and fusion into myofibres with greater activity in muscles proximal to the injury site. Conditional depletion of satellite cells attenuates recovery of myofibre area and volume following a scald burn injury in mice. Skeletal muscle regrowth following a burn injury requires satellite cell activity, underscoring the therapeutic potential of satellite cells in the prevention of prolonged frailty in burn survivors. Severe burns result in profound skeletal muscle atrophy; persistent muscle atrophy and weakness are major complications that hamper recovery from burn injury. Many factors contribute to the erosion of muscle mass following burn trauma, and we have previously shown concurrent activation and apoptosis of muscle satellite cells following a burn injury in paediatric patients. To determine the necessity of satellite cells during muscle recovery following a burn injury, we utilized a genetically modified mouse model (Pax7 CreER -DTA) that allows for the conditional depletion of satellite cells in skeletal muscle. Additionally, mice were provided 5-ethynyl-2'-deoxyuridine to determine satellite cell proliferation, activation and fusion. Juvenile satellite cell-wild-type (SC-WT) and satellite cell-depleted (SC-Dep) mice (8 weeks of age) were randomized to sham or burn injury consisting of a dorsal scald burn injury covering 30% of total body surface area. Both hindlimb and dorsal muscles were studied at 7, 14 and 21 days post-burn. SC-Dep mice had >93% depletion of satellite cells compared to SC-WT (P satellite cell proliferation and fusion. Depletion of satellite cells impaired post-burn recovery of both muscle fibre cross-sectional area and volume (P satellite cells in the aetiology of lean

Muscle Fiber Characteristics, Satellite Cells and Soccer Performance in Young Athletes

Directory of Open Access Journals (Sweden)

Thomas I. Metaxas, Athanasios Mandroukas, Efstratios Vamvakoudis, Kostas Kotoglou, Björn Ekblom, Konstantinos Mandroukas

2014-09-01

Full Text Available This study is aimed to examine the muscle fiber type, composition and satellite cells in young male soccer players and to correlate them to cardiorespiratory indices and muscle strength. The participants formed three Groups: Group A (n = 13, 11.2 ± 0.4yrs, Group B (n=10, 13.1 ± 0.5yrs and Group C (n = 9, 15.2 ± 0.6yrs. Muscle biopsies were obtained from the vastus lateralis. Peak torque values of the quadriceps and hamstrings were recorded and VO2max was measured on the treadmill. Group C had lower type I percentage distribution compared to A by 21.3% (p < 0.01, while the type IIA relative percentage was higher by 18.1% and 18.4% than in Groups A and B (p < 0.05. Groups B and C had higher cross-sectional area (CSA values in all fiber types than in Group A (0.05 < p < 0.001. The number of satellite cells did not differ between the groups. Groups B and C had higher peak torque at all angular velocities and absolute VO2max in terms of ml·min-1 than Group A (0.05 < p < 0.001. It is concluded that the increased percentage of type IIA muscle fibers noticed in Group C in comparison to the Groups A and B should be mainly attributed to the different workload exercise and training programs. The alteration of myosin heavy chain (MHC isoforms composition even in children is an important mechanism for skeletal muscle characteristics. Finally, CSA, isokinetic muscle strength and VO2max values seems to be expressed according to age.

High-frequency irreversible electroporation (H-FIRE for non-thermal ablation without muscle contraction

Directory of Open Access Journals (Sweden)

Arena Christopher B

2011-11-01

Full Text Available Abstract Background Therapeutic irreversible electroporation (IRE is an emerging technology for the non-thermal ablation of tumors. The technique involves delivering a series of unipolar electric pulses to permanently destabilize the plasma membrane of cancer cells through an increase in transmembrane potential, which leads to the development of a tissue lesion. Clinically, IRE requires the administration of paralytic agents to prevent muscle contractions during treatment that are associated with the delivery of electric pulses. This study shows that by applying high-frequency, bipolar bursts, muscle contractions can be eliminated during IRE without compromising the non-thermal mechanism of cell death. Methods A combination of analytical, numerical, and experimental techniques were performed to investigate high-frequency irreversible electroporation (H-FIRE. A theoretical model for determining transmembrane potential in response to arbitrary electric fields was used to identify optimal burst frequencies and amplitudes for in vivo treatments. A finite element model for predicting thermal damage based on the electric field distribution was used to design non-thermal protocols for in vivo experiments. H-FIRE was applied to the brain of rats, and muscle contractions were quantified via accelerometers placed at the cervicothoracic junction. MRI and histological evaluation was performed post-operatively to assess ablation. Results No visual or tactile evidence of muscle contraction was seen during H-FIRE at 250 kHz or 500 kHz, while all IRE protocols resulted in detectable muscle contractions at the cervicothoracic junction. H-FIRE produced ablative lesions in brain tissue that were characteristic in cellular morphology of non-thermal IRE treatments. Specifically, there was complete uniformity of tissue death within targeted areas, and a sharp transition zone was present between lesioned and normal brain. Conclusions H-FIRE is a feasible technique for

Low density lipoprotein uptake by an endothelial-smooth muscle cell bilayer

International Nuclear Information System (INIS)

Alexander, J.J.; Miguel, R.; Graham, D.

1991-01-01

To study the interaction of endothelial and smooth muscle cells, and the means by which such interaction may affect lipid permeability of the arterial wall, cell bilayers were established by use of a transwell culture system. After confluent growth of both cell types had been achieved, iodine 125 bound to low-density lipoprotein (10 ng protein/ml) was added to the media of the upper well. After a 3-hour incubation period, the iodine 125-bound low-density lipoprotein content of the upper and lower media demonstrated an impedance to lipoprotein movement across the endothelial cell monolayer as compared to the bare porous polycarbonate filter of the transwell (p less than 10(-6)). The presence of smooth muscle cells in the bottom well significantly enhanced the permeability of the endothelial cell layer (p less than 10(-60)). This effect remained unchanged over a 9-day time course. Membrane binding and cellular uptake of low-density lipoprotein by endothelial cells was not altered by smooth muscle cells, indicating that this change in permeability could not be easily attributed to changes in receptor-mediated transport or transcytosis. Membrane binding (p less than 0.02) and cellular uptake (p less than 10(-6)) of low-density lipoprotein by smooth muscle cells in the bilayer, when adjusted for counts available in the smooth muscle cell media, were both reduced in the early incubation period as compared to isolated smooth muscle cells. The disproportionate reduction in uptake as compared to binding would suggest that this was not entirely a receptor-dependent process

Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

Science.gov (United States)

Cornelison, Ddw; Perdiguero, Eusebio

2017-01-01

Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

Skeletal myogenic differentiation of human urine-derived cells as a potential source for skeletal muscle regeneration.

Science.gov (United States)

Chen, Wei; Xie, Minkai; Yang, Bin; Bharadwaj, Shantaram; Song, Lujie; Liu, Guihua; Yi, Shanhong; Ye, Gang; Atala, Anthony; Zhang, Yuanyuan

2017-02-01

Stem cells are regarded as possible cell therapy candidates for skeletal muscle regeneration. However, invasive harvesting of those cells can cause potential harvest-site morbidity. The goal of this study was to assess whether human urine-derived stem cells (USCs), obtained through non-invasive procedures, can differentiate into skeletal muscle linage cells (Sk-MCs) and potentially be used for skeletal muscle regeneration. In this study, USCs were harvested from six healthy individuals aged 25-55. Expression profiles of cell-surface markers were assessed by flow cytometry. To optimize the myogenic differentiation medium, we selected two from four different types of myogenic differentiation media to induce the USCs. Differentiated USCs were identified with myogenic markers by gene and protein expression. USCs were implanted into the tibialis anterior muscles of nude mice for 1 month. The results showed that USCs displayed surface markers with positive staining for CD24, CD29, CD44, CD73, CD90, CD105, CD117, CD133, CD146, SSEA-4 and STRO-1, and negative staining for CD14, CD31, CD34 and CD45. After myogenic differentiation, a change in morphology was observed from 'rice-grain'-like cells to spindle-shaped cells. The USCs expressed specific Sk-MC transcripts and protein markers (myf5, myoD, myosin, and desmin) after being induced with different myogenic culture media. Implanted cells expressed Sk-MC markers stably in vivo. Our findings suggest that USCs are able to differentiate into the Sk-MC lineage in vitro and after being implanted in vivo. Thus, they might be a potential source for cell injection therapy in the use of skeletal muscle regeneration. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Skeletal Muscle Regeneration, Repair and Remodelling in Aging: The Importance of Muscle Stem Cells and Vascularization.

Science.gov (United States)

Joanisse, Sophie; Nederveen, Joshua P; Snijders, Tim; McKay, Bryon R; Parise, Gianni

2017-01-01

Sarcopenia is the age-related loss of skeletal muscle mass and strength. Ultimately, sarcopenia results in the loss of independence, which imposes a large financial burden on healthcare systems worldwide. A critical facet of sarcopenia is the diminished ability for aged muscle to regenerate, repair and remodel. Over the years, research has focused on elucidating underlying mechanisms of sarcopenia and the impaired ability of muscle to respond to stimuli with aging. Muscle-specific stem cells, termed satellite cells (SC), play an important role in maintaining muscle health throughout the lifespan. It is well established that SC are essential in skeletal muscle regeneration, and it has been hypothesized that a reduction and/or dysregulation of the SC pool, may contribute to accelerated loss of skeletal muscle mass that is observed with advancing age. The preservation of skeletal muscle tissue and its ability to respond to stimuli may be impacted by reduced SC content and impaired function observed with aging. Aging is also associated with a reduction in capillarization of skeletal muscle. We have recently demonstrated that the distance between type II fibre-associated SC and capillaries is greater in older compared to younger adults. The greater distance between SC and capillaries in older adults may contribute to the dysregulation in SC activation ultimately impairing muscle's ability to remodel and, in extreme circumstances, regenerate. This viewpoint will highlight the importance of optimal SC activation in addition to skeletal muscle capillarization to maximize the regenerative potential of skeletal muscle in older adults. © 2016 S. Karger AG, Basel.

Immortalized human myotonic dystrophy muscle cell lines to assess therapeutic compounds

Science.gov (United States)

Arandel, Ludovic; Polay Espinoza, Micaela; Matloka, Magdalena; Bazinet, Audrey; De Dea Diniz, Damily; Naouar, Naïra; Rau, Frédérique; Jollet, Arnaud; Edom-Vovard, Frédérique; Mamchaoui, Kamel; Tarnopolsky, Mark; Puymirat, Jack; Battail, Christophe; Boland, Anne; Deleuze, Jean-Francois; Mouly, Vincent; Klein, Arnaud F.

2017-01-01

ABSTRACT Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are autosomal dominant neuromuscular diseases caused by microsatellite expansions and belong to the family of RNA-dominant disorders. Availability of cellular models in which the DM mutation is expressed within its natural context is essential to facilitate efforts to identify new therapeutic compounds. Here, we generated immortalized DM1 and DM2 human muscle cell lines that display nuclear RNA aggregates of expanded repeats, a hallmark of myotonic dystrophy. Selected clones of DM1 and DM2 immortalized myoblasts behave as parental primary myoblasts with a reduced fusion capacity of immortalized DM1 myoblasts when compared with control and DM2 cells. Alternative splicing defects were observed in differentiated DM1 muscle cell lines, but not in DM2 lines. Splicing alterations did not result from differentiation delay because similar changes were found in immortalized DM1 transdifferentiated fibroblasts in which myogenic differentiation has been forced by overexpression of MYOD1. As a proof-of-concept, we show that antisense approaches alleviate disease-associated defects, and an RNA-seq analysis confirmed that the vast majority of mis-spliced events in immortalized DM1 muscle cells were affected by antisense treatment, with half of them significantly rescued in treated DM1 cells. Immortalized DM1 muscle cell lines displaying characteristic disease-associated molecular features such as nuclear RNA aggregates and splicing defects can be used as robust readouts for the screening of therapeutic compounds. Therefore, immortalized DM1 and DM2 muscle cell lines represent new models and tools to investigate molecular pathophysiological mechanisms and evaluate the in vitro effects of compounds on RNA toxicity associated with myotonic dystrophy mutations. PMID:28188264

Immortalized human myotonic dystrophy muscle cell lines to assess therapeutic compounds

Directory of Open Access Journals (Sweden)

Ludovic Arandel

2017-04-01

Full Text Available Myotonic dystrophy type 1 (DM1 and type 2 (DM2 are autosomal dominant neuromuscular diseases caused by microsatellite expansions and belong to the family of RNA-dominant disorders. Availability of cellular models in which the DM mutation is expressed within its natural context is essential to facilitate efforts to identify new therapeutic compounds. Here, we generated immortalized DM1 and DM2 human muscle cell lines that display nuclear RNA aggregates of expanded repeats, a hallmark of myotonic dystrophy. Selected clones of DM1 and DM2 immortalized myoblasts behave as parental primary myoblasts with a reduced fusion capacity of immortalized DM1 myoblasts when compared with control and DM2 cells. Alternative splicing defects were observed in differentiated DM1 muscle cell lines, but not in DM2 lines. Splicing alterations did not result from differentiation delay because similar changes were found in immortalized DM1 transdifferentiated fibroblasts in which myogenic differentiation has been forced by overexpression of MYOD1. As a proof-of-concept, we show that antisense approaches alleviate disease-associated defects, and an RNA-seq analysis confirmed that the vast majority of mis-spliced events in immortalized DM1 muscle cells were affected by antisense treatment, with half of them significantly rescued in treated DM1 cells. Immortalized DM1 muscle cell lines displaying characteristic disease-associated molecular features such as nuclear RNA aggregates and splicing defects can be used as robust readouts for the screening of therapeutic compounds. Therefore, immortalized DM1 and DM2 muscle cell lines represent new models and tools to investigate molecular pathophysiological mechanisms and evaluate the in vitro effects of compounds on RNA toxicity associated with myotonic dystrophy mutations.

Immortalized human myotonic dystrophy muscle cell lines to assess therapeutic compounds.

Science.gov (United States)

Arandel, Ludovic; Polay Espinoza, Micaela; Matloka, Magdalena; Bazinet, Audrey; De Dea Diniz, Damily; Naouar, Naïra; Rau, Frédérique; Jollet, Arnaud; Edom-Vovard, Frédérique; Mamchaoui, Kamel; Tarnopolsky, Mark; Puymirat, Jack; Battail, Christophe; Boland, Anne; Deleuze, Jean-Francois; Mouly, Vincent; Klein, Arnaud F; Furling, Denis

2017-04-01

Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are autosomal dominant neuromuscular diseases caused by microsatellite expansions and belong to the family of RNA-dominant disorders. Availability of cellular models in which the DM mutation is expressed within its natural context is essential to facilitate efforts to identify new therapeutic compounds. Here, we generated immortalized DM1 and DM2 human muscle cell lines that display nuclear RNA aggregates of expanded repeats, a hallmark of myotonic dystrophy. Selected clones of DM1 and DM2 immortalized myoblasts behave as parental primary myoblasts with a reduced fusion capacity of immortalized DM1 myoblasts when compared with control and DM2 cells. Alternative splicing defects were observed in differentiated DM1 muscle cell lines, but not in DM2 lines. Splicing alterations did not result from differentiation delay because similar changes were found in immortalized DM1 transdifferentiated fibroblasts in which myogenic differentiation has been forced by overexpression of MYOD1. As a proof-of-concept, we show that antisense approaches alleviate disease-associated defects, and an RNA-seq analysis confirmed that the vast majority of mis-spliced events in immortalized DM1 muscle cells were affected by antisense treatment, with half of them significantly rescued in treated DM1 cells. Immortalized DM1 muscle cell lines displaying characteristic disease-associated molecular features such as nuclear RNA aggregates and splicing defects can be used as robust readouts for the screening of therapeutic compounds. Therefore, immortalized DM1 and DM2 muscle cell lines represent new models and tools to investigate molecular pathophysiological mechanisms and evaluate the in vitro effects of compounds on RNA toxicity associated with myotonic dystrophy mutations. © 2017. Published by The Company of Biologists Ltd.

Catechins activate muscle stem cells by Myf5 induction and stimulate muscle regeneration.

Science.gov (United States)

Kim, A Rum; Kim, Kyung Min; Byun, Mi Ran; Hwang, Jun-Ha; Park, Jung Il; Oh, Ho Taek; Kim, Hyo Kyeong; Jeong, Mi Gyeong; Hwang, Eun Sook; Hong, Jeong-Ho

2017-07-22

Muscle weakness is one of the most common symptoms in aged individuals and increases risk of mortality. Thus, maintenance of muscle mass is important for inhibiting aging. In this study, we investigated the effect of catechins, polyphenol compounds in green tea, on muscle regeneration. We found that (-)-epicatechin gallate (ECG) and (-)-epigallocatechin-3-gallate (EGCG) activate satellite cells by induction of Myf5 transcription factors. For satellite cell activation, Akt kinase was significantly induced after ECG treatment and ECG-induced satellite cell activation was blocked in the presence of Akt inhibitor. ECG also promotes myogenic differentiation through the induction of myogenic markers, including Myogenin and Muscle creatine kinase (MCK), in satellite and C2C12 myoblast cells. Finally, EGCG administration to mice significantly increased muscle fiber size for regeneration. Taken together, the results suggest that catechins stimulate muscle stem cell activation and differentiation for muscle regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

A Review of Non-Invasive Techniques to Detect and Predict Localised Muscle Fatigue

Directory of Open Access Journals (Sweden)

Mohamed R. Al-Mulla

2011-03-01

Full Text Available Muscle fatigue is an established area of research and various types of muscle fatigue have been investigated in order to fully understand the condition. This paper gives an overview of the various non-invasive techniques available for use in automated fatigue detection, such as mechanomyography, electromyography, near-infrared spectroscopy and ultrasound for both isometric and non-isometric contractions. Various signal analysis methods are compared by illustrating their applicability in real-time settings. This paper will be of interest to researchers who wish to select the most appropriate methodology for research on muscle fatigue detection or prediction, or for the development of devices that can be used in, e.g., sports scenarios to improve performance or prevent injury. To date, research on localised muscle fatigue focuses mainly on the clinical side. There is very little research carried out on the implementation of detecting/predicting fatigue using an autonomous system, although recent research on automating the process of localised muscle fatigue detection/prediction shows promising results.

A Review of Non-Invasive Techniques to Detect and Predict Localised Muscle Fatigue

Science.gov (United States)

Al-Mulla, Mohamed R.; Sepulveda, Francisco; Colley, Martin

2011-01-01

Muscle fatigue is an established area of research and various types of muscle fatigue have been investigated in order to fully understand the condition. This paper gives an overview of the various non-invasive techniques available for use in automated fatigue detection, such as mechanomyography, electromyography, near-infrared spectroscopy and ultrasound for both isometric and non-isometric contractions. Various signal analysis methods are compared by illustrating their applicability in real-time settings. This paper will be of interest to researchers who wish to select the most appropriate methodology for research on muscle fatigue detection or prediction, or for the development of devices that can be used in, e.g., sports scenarios to improve performance or prevent injury. To date, research on localised muscle fatigue focuses mainly on the clinical side. There is very little research carried out on the implementation of detecting/predicting fatigue using an autonomous system, although recent research on automating the process of localised muscle fatigue detection/prediction shows promising results. PMID:22163810

Loss of MyoD and Myf5 in Skeletal Muscle Stem Cells Results in Altered Myogenic Programming and Failed Regeneration

Directory of Open Access Journals (Sweden)

Masakazu Yamamoto

2018-03-01

Full Text Available Summary: MyoD and Myf5 are fundamental regulators of skeletal muscle lineage determination in the embryo, and their expression is induced in satellite cells following muscle injury. MyoD and Myf5 are also expressed by satellite cell precursors developmentally, although the relative contribution of historical and injury-induced expression to satellite cell function is unknown. We show that satellite cells lacking both MyoD and Myf5 (double knockout [dKO] are maintained with aging in uninjured muscle. However, injured muscle fails to regenerate and dKO satellite cell progeny accumulate in damaged muscle but do not undergo muscle differentiation. dKO satellite cell progeny continue to express markers of myoblast identity, although their myogenic programming is labile, as demonstrated by dramatic morphological changes and increased propensity for non-myogenic differentiation. These data demonstrate an absolute requirement for either MyoD or Myf5 in muscle regeneration and indicate that their expression after injury stabilizes myogenic identity and confers the capacity for muscle differentiation. : In this article, Goldhamer and colleagues show that loss of both MyoD and Myf5 in skeletal muscle satellite cells results in regenerative failure following injury. Satellite cell progeny accumulate in injured muscle and continue to express markers of myoblast identity, but do not undergo muscle differentiation, and exhibit a propensity for non-myogenic differentiation. Keywords: skeletal muscle regeneration, muscle stem cell programming, muscle differentiation, satellite cell, MyoD, Myf5, adipogenesis, fibrosis, conditional knockout, Cre/loxP

Phenotype and Functional Features of Human Telomerase Reverse Transcriptase Immortalized Human Airway Smooth Muscle Cells from Asthmatic and Non-Asthmatic Donors.

Science.gov (United States)

Burgess, J K; Ketheson, A; Faiz, A; Limbert Rempel, K A; Oliver, B G; Ward, J P T; Halayko, A J

2018-01-16

Asthma is an obstructive respiratory disease characterised by chronic inflammation with airway hyperresponsiveness. In asthmatic airways, there is an increase in airway smooth muscle (ASM) cell bulk, which differs from non-asthmatic ASM in characteristics. This study aimed to assess the usefulness of hTERT immortalisation of human ASM cells as a research tool. Specifically we compared proliferative capacity, inflammatory mediator release and extracellular matrix (ECM) production in hTERT immortalised and parent primary ASM cells from asthmatic and non-asthmatic donors. Our studies revealed no significant differences in proliferation, IL-6 and eotaxin-1 production, or CTGF synthesis between donor-matched parent and hTERT immortalised ASM cell lines. However, deposition of ECM proteins fibronectin and fibulin-1 was significantly lower in immortalised ASM cells compared to corresponding primary cells. Notably, previously reported differences in proliferation and inflammatory mediator release between asthmatic and non-asthmatic ASM cells were retained, but excessive ECM protein deposition in asthmatic ASM cells was lost in hTERT ASM cells. This study shows that hTERT immortalised ASM cells mirror primary ASM cells in proliferation and inflammatory profile characteristics. Moreover, we demonstrate both strengths and weaknesses of this immortalised cell model as a representation of primary ASM cells for future asthma pathophysiological research.

Detecting and Predicting Muscle Fatigue during Typing By SEMG Signal Processing and Artificial Neural Networks

Directory of Open Access Journals (Sweden)

Elham Ghoochani

2011-03-01

Full Text Available Introduction: Repetitive strain injuries are one of the most prevalent problems in occupational diseases. Repetition, vibration and bad postures of the extremities are physical risk factors related to work that can cause chronic musculoskeletal disorders. Repetitive work on a computer with low level contraction requires the posture to be maintained for a long time, which can cause muscle fatigue. Muscle fatigue in shoulders and neck is one of the most prevalent problems reported with computer users especially during typing. Surface electromyography (SEMG signals are used for detecting muscle fatigue as a non-invasive method. Material and Methods: Nine healthy females volunteered for signal recoding during typing. EMG signals were recorded from the trapezius muscle, which is subjected to muscle fatigue during typing.  After signal analysis and feature extraction, detecting and predicting muscle fatigue was performed by using the MLP artificial neural network. Results: Recorded signals were analyzed in time and frequency domains for feature extraction. Results of classification showed that the MLP neural network can detect and predict muscle fatigue during typing with 80.79 % ± 1.04% accuracy. Conclusion: Intelligent classification and prediction of muscle fatigue can have many applications in human factors engineering (ergonomics, rehabilitation engineering and biofeedback equipment for mitigating the injuries of repetitive works.

Pluripotent Conversion of Muscle Stem Cells Without Reprogramming Factors or Small Molecules.

Science.gov (United States)

Bose, Bipasha; Shenoy P, Sudheer

2016-02-01

Muscle derived stem cells (MDSCs) are multipotent stem cells that can differentiate into several lineages including skeletal muscle precursor cells. Here, we show that MDSCs from myostatin null mice (Mstn (-/-) ) can be readily induced into pluripotent stem cells without using reprogramming factors. Microarray studies revealed a strong upregulation of markers like Leukemia Inhibitory factor (LIF) and Leukemia Inhibitory factor receptor (LIFR) in Mstn (-/-) MDSCs as compared to wild type MDSCs (WT-MDSCs). Furthermore when cultured in mouse embryonic stem cell media with LIF for 95 days, Mstn (-/-) MDSCs formed embryonic stem cell (ES) like colonies. We termed such ES like cells as the culture-induced pluripotent stem cells (CiPSC). CiPSCs from Mstn (-/-) MDSCs were phenotypically similar to ESCs, expressed high levels of Oct4, Nanog, Sox2 and SSEA-1, maintained a normal karyotype. Furthermore, CiPSCs formed embryoid bodies and teratomas when injected into immunocompromised mice. In addition, CiPSCs differentiated into somatic cells of all three lineages. We further show that culturing in ES cell media, resulted in hypermethylation and downregulation of BMP2 in Mstn(-/-) MDSCs. Western blot further confirmed a down regulation of BMP2 signaling in Mstn (-/-) MDSCs in supportive of pluripotent reprogramming. Given that down regulation of BMP2 has been shown to induce pluripotency in cells, we propose that lack of myostatin epigenetically reprograms the MDSCs to become pluripotent stem cells. Thus, here we report the successful establishment of ES-like cells from adult stem cells of the non-germline origin under culture-induced conditions without introducing reprogramming genes.

Muscle Contraction.

Science.gov (United States)

Sweeney, H Lee; Hammers, David W

2018-02-01

SUMMARYMuscle cells are designed to generate force and movement. There are three types of mammalian muscles-skeletal, cardiac, and smooth. Skeletal muscles are attached to bones and move them relative to each other. Cardiac muscle comprises the heart, which pumps blood through the vasculature. Skeletal and cardiac muscles are known as striated muscles, because the filaments of actin and myosin that power their contraction are organized into repeating arrays, called sarcomeres, that have a striated microscopic appearance. Smooth muscle does not contain sarcomeres but uses the contraction of filaments of actin and myosin to constrict blood vessels and move the contents of hollow organs in the body. Here, we review the principal molecular organization of the three types of muscle and their contractile regulation through signaling mechanisms and discuss their major structural and functional similarities that hint at the possible evolutionary relationships between the cell types. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Fetal muscle-type nicotinic acetylcholine receptor activation in TE-671 cells and inhibition of fetal movement in a day 40 pregnant goat model by optical isomers of the piperidine alkaloid coniine.

Science.gov (United States)

Green, Benedict T; Lee, Stephen T; Welch, Kevin D; Pfister, James A; Panter, Kip E

2013-01-01

Coniine is an optically active toxic piperidine alkaloid and nicotinic acetylcholine receptor (nAChR) agonist found in poison hemlock (Conium maculatum L.). Coniine teratogenicity is hypothesized to be attributable to the binding, activation, and prolonged desensitization of fetal muscle-type nAChR, which results in the complete inhibition of fetal movement. However, pharmacological evidence of coniine actions at fetal muscle-type nAChR is lacking. The present study compared (-)-coniine, (+)-coniine, and nicotine for the ability to inhibit fetal movement in a day 40 pregnant goat model and in TE-671 cells that express fetal muscle-type nAChR. Furthermore, α-conotoxins (CTx) EI and GI were used to antagonize the actions of (+)- and (-)-coniine in TE-671 cells. (-)-Coniine was more effective at eliciting electrical changes in TE-671 cells and inhibiting fetal movement than was (+)-coniine, suggesting stereoselectivity by the receptor. The pyridine alkaloid nicotine did not inhibit fetal movement in a day 40 pregnant goat model, suggesting agonist specificity for the inhibition of fetal movement. Low concentrations of both CTxs potentiated the TE-671 cell response and higher concentrations of CTx EI, and GI antagonized the actions of both coniine enantiomers demonstrating concentration-dependent coagonism and selective antagonism. These results provide pharmacological evidence that the piperidine alkaloid coniine is acting at fetal muscle-type nAChR in a concentration-dependent manner.

"Known Unknowns": Current Questions in Muscle Satellite Cell Biology.

Science.gov (United States)

Cornelison, Ddw

2018-01-01

Our understanding of satellite cells, now known to be the obligate stem cells of skeletal muscle, has increased dramatically in recent years due to the introduction of new molecular, genetic, and technical resources. In addition to their role in acute repair of damaged muscle, satellite cells are of interest in the fields of aging, exercise, neuromuscular disease, and stem cell therapy, and all of these applications have driven a dramatic increase in our understanding of the activity and potential of satellite cells. However, many fundamental questions of satellite cell biology remain to be answered, including their emergence as a specific lineage, the degree and significance of heterogeneity within the satellite cell population, the roles of their interactions with other resident and infiltrating cell types during homeostasis and regeneration, and the relative roles of intrinsic vs extrinsic factors that may contribute to satellite cell dysfunction in the context of aging or disease. This review will address the current state of these open questions in satellite cell biology. © 2018 Elsevier Inc. All rights reserved.

Fibronectin promotes differentiation of neural crest progenitors endowed with smooth muscle cell potential

International Nuclear Information System (INIS)

Costa-Silva, Bruno; Coelho da Costa, Meline; Melo, Fernanda Rosene; Neves, Cynara Mendes; Alvarez-Silva, Marcio; Calloni, Giordano Wosgrau; Trentin, Andrea Goncalves

2009-01-01

The neural crest (NC) is a model system used to investigate multipotency during vertebrate development. Environmental factors control NC cell fate decisions. Despite the well-known influence of extracellular matrix molecules in NC cell migration, the issue of whether they also influence NC cell differentiation has not been addressed at the single cell level. By analyzing mass and clonal cultures of mouse cephalic and quail trunk NC cells, we show for the first time that fibronectin (FN) promotes differentiation into the smooth muscle cell phenotype without affecting differentiation into glia, neurons, and melanocytes. Time course analysis indicated that the FN-induced effect was not related to massive cell death or proliferation of smooth muscle cells. Finally, by comparing clonal cultures of quail trunk NC cells grown on FN and collagen type IV (CLIV), we found that FN strongly increased both NC cell survival and the proportion of unipotent and oligopotent NC progenitors endowed with smooth muscle potential. In contrast, melanocytic progenitors were prominent in clonogenic NC cells grown on CLIV. Taken together, these results show that FN promotes NC cell differentiation along the smooth muscle lineage, and therefore plays an important role in fate decisions of NC progenitor cells

Heterogeneity among muscle precursor cells in adult skeletal muscles with differing regenerative capacities.

Science.gov (United States)

Pavlath, G K; Thaloor, D; Rando, T A; Cheong, M; English, A W; Zheng, B

1998-08-01

Skeletal muscle has a remarkable capacity to regenerate after injury, although studies of muscle regeneration have heretofore been limited almost exclusively to limb musculature. Muscle precursor cells in skeletal muscle are responsible for the repair of damaged muscle. Heterogeneity exists in the growth and differentiation properties of muscle precursor cell (myoblast) populations throughout limb development but whether the muscle precursor cells differ among adult skeletal muscles is unknown. Such heterogeneity among myoblasts in the adult may give rise to skeletal muscles with different regenerative capacities. Here we compare the regenerative response of a masticatory muscle, the masseter, to that of limb muscles. After exogenous trauma (freeze or crush injuries), masseter muscle regenerated much less effectively than limb muscle. In limb muscle, normal architecture was restored 12 days after injury, whereas in masseter muscle, minimal regeneration occurred during the same time period. Indeed, at late time points, masseter muscles exhibited increased fibrous connective tissue in the region of damage, evidence of ineffective muscle regeneration. Similarly, in response to endogenous muscle injury due to a muscular dystrophy, widespread evidence of impaired regeneration was present in masseter muscle but not in limb muscle. To explore the cellular basis of these different regenerative capacities, we analyzed the myoblast populations of limb and masseter muscles both in vivo and in vitro. From in vivo analyses, the number of myoblasts in regenerating muscle was less in masseter compared with limb muscle. Assessment of population growth in vitro indicated that masseter myoblasts grow more slowly than limb myoblasts under identical conditions. We conclude that the impaired regeneration in masseter muscles is due to differences in the intrinsic myoblast populations compared to limb muscles.

Pervasive satellite cell contribution to uninjured adult muscle fibers.

Science.gov (United States)

Pawlikowski, Bradley; Pulliam, Crystal; Betta, Nicole Dalla; Kardon, Gabrielle; Olwin, Bradley B

2015-01-01

Adult skeletal muscle adapts to functional needs, maintaining consistent numbers of myonuclei and stem cells. Although resident muscle stem cells or satellite cells are required for muscle growth and repair, in uninjured muscle, these cells appear quiescent and metabolically inactive. To investigate the satellite cell contribution to myofibers in adult uninjured skeletal muscle, we labeled satellite cells by inducing a recombination of LSL-tdTomato in Pax7(CreER) mice and scoring tdTomato+ myofibers as an indicator of satellite cell fusion. Satellite cell fusion into myofibers plateaus postnatally between 8 and 12 weeks of age, reaching a steady state in hindlimb muscles, but in extra ocular or diaphragm muscles, satellite cell fusion is maintained at postnatal levels irrespective of the age assayed. Upon recombination and following a 2-week chase in 6-month-old mice, tdTomato-labeled satellite cells fused into myofibers as 20, 50, and 80 % of hindlimb, extra ocular, and diaphragm myofibers, respectively, were tdTomato+. Satellite cells contribute to uninjured myofibers either following a cell division or directly without an intervening cell division. The frequency of satellite cell fusion into the skeletal muscle fibers is greater than previously estimated, suggesting an important functional role for satellite cell fusion into adult myofibers and a requirement for active maintenance of satellite cell numbers in uninjured skeletal muscle.

Sodium leak channel, non-selective contributes to the leak current in human myometrial smooth muscle cells from pregnant women.

Science.gov (United States)

Reinl, Erin L; Cabeza, Rafael; Gregory, Ismail A; Cahill, Alison G; England, Sarah K

2015-10-01

Uterine contractions are tightly regulated by the electrical activity of myometrial smooth muscle cells (MSMCs). These cells require a depolarizing current to initiate Ca(2+) influx and induce contraction. Cationic leak channels, which permit a steady flow of cations into a cell, are known to cause membrane depolarization in many tissue types. Previously, a Gd(3+)-sensitive, Na(+)-dependent leak current was identified in the rat myometrium, but the presence of such a current in human MSMCs and the specific ion channel conducting this current was unknown. Here, we report the presence of a Na(+)-dependent leak current in human myometrium and demonstrate that the Na(+)-leak channel, NALCN, contributes to this current. We performed whole-cell voltage-clamp on fresh and cultured MSMCs from uterine biopsies of term, non-laboring women and isolated the leak currents by using Ca(2+) and K(+) channel blockers in the bath solution. Ohmic leak currents were identified in freshly isolated and cultured MSMCs with normalized conductances of 14.6 pS/pF and 10.0 pS/pF, respectively. The myometrial leak current was significantly reduced (P < 0.01) by treating cells with 10 μM Gd(3+) or by superfusing the cells with a Na(+)-free extracellular solution. Reverse transcriptase PCR and immunoblot analysis of uterine biopsies from term, non-laboring women revealed NALCN messenger RNA and protein expression in the myometrium. Notably, ∼90% knockdown of NALCN protein expression with lentivirus-delivered shRNA reduced the Gd(3+)-sensitive leak current density by 42% (P < 0.05). Our results reveal that NALCN, in part, generates the leak current in MSMCs and provide the basis for future research assessing NALCN as a potential molecular target for modulating uterine excitability. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hydroxyapatite and Calcified Elastin Induce Osteoblast-like Differentiation in Rat Aortic Smooth Muscle Cells

Science.gov (United States)

Lei, Yang; Sinha, Aditi; Nosoudi, Nasim; Grover, Ankit; Vyavahare, Naren

2014-01-01

Vascular calcification can be categorized into two different types. Intimal calcification related to atherosclerosis and elastin-specific medial arterial calcification (MAC). Osteoblast-like differentiation of vascular smooth muscle cells (VSMCs) has been shown in both types; however, how this relates to initiation of vascular calcification is unclear. We hypothesize that the initial deposition of hydroxyapatite-like mineral in MAC occurs on degraded elastin first and that causes osteogenic transformation of VSMCs. To test this, rat aortic smooth muscle cells (RASMCs) were cultured on hydroxyapatite crystals and calcified aortic elastin. Using RT-PCR and specific protein assays, we demonstrate that RASMCs lose their smooth muscle lineage markers like alpha smooth muscle actin (SMA) and myosin heavy chain (MHC) and undergo chondrogenic/osteogenic transformation. This is indicated by an increase in the expression of typical chondrogenic proteins such as aggrecan, collagen type II alpha 1(Col2a1) and bone proteins such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP) and osteocalcin (OCN). Furthermore, when calcified conditions are removed, cells return to their original phenotype. Our data supports the hypothesis that elastin degradation and calcification precedes VSMCs' osteoblast-like differentiation. PMID:24447384

Tissue-specific stem cells: Lessons from the skeletal muscle satellite cell

Science.gov (United States)

Brack, Andrew S.; Rando, Thomas A.

2012-01-01

In 1961, the satellite cell was first identified when electron microscopic examination of skeletal muscle demonstrated a cell wedged between the plasma membrane of the muscle fiber and the basement membrane. In recent years it has been conclusively demonstrated that the satellite cell is the primary cellular source for muscle regeneration and is equipped with the potential to self renew, thus functioning as a bone fide skeletal muscle stem cell (MuSC). As we move past the 50th anniversary of the satellite cell, we take this opportunity to discuss the current state of the art and dissect the unknowns in the MuSC field. PMID:22560074

Regenerative capacity of old muscle stem cells declines without significant accumulation of DNA damage.

Directory of Open Access Journals (Sweden)

Wendy Cousin

Full Text Available The performance of adult stem cells is crucial for tissue homeostasis but their regenerative capacity declines with age, leading to failure of multiple organs. In skeletal muscle this failure is manifested by the loss of functional tissue, the accumulation of fibrosis, and reduced satellite cell-mediated myogenesis in response to injury. While recent studies have shown that changes in the composition of the satellite cell niche are at least in part responsible for the impaired function observed with aging, little is known about the effects of aging on the intrinsic properties of satellite cells. For instance, their ability to repair DNA damage and the effects of a potential accumulation of DNA double strand breaks (DSBs on their regenerative performance remain unclear. This work demonstrates that old muscle stem cells display no significant accumulation of DNA DSBs when compared to those of young, as assayed after cell isolation and in tissue sections, either in uninjured muscle or at multiple time points after injury. Additionally, there is no significant difference in the expression of DNA DSB repair proteins or globally assayed DNA damage response genes, suggesting that not only DNA DSBs, but also other types of DNA damage, do not significantly mark aged muscle stem cells. Satellite cells from DNA DSB-repair-deficient SCID mice do have an unsurprisingly higher level of innate DNA DSBs and a weakened recovery from gamma-radiation-induced DNA damage. Interestingly, they are as myogenic in vitro and in vivo as satellite cells from young wild type mice, suggesting that the inefficiency in DNA DSB repair does not directly correlate with the ability to regenerate muscle after injury. Overall, our findings suggest that a DNA DSB-repair deficiency is unlikely to be a key factor in the decline in muscle regeneration observed upon aging.

Quercetin inhibits adipogenesis of muscle progenitor cells in vitro

Directory of Open Access Journals (Sweden)

Tomoko Funakoshi

2018-03-01

Full Text Available Muscle satellite cells are committed myogenic progenitors capable of contributing to myogenesis to maintain adult muscle mass and function. Several experiments have demonstrated that muscle satellite cells can differentiate into adipocytes in vitro, supporting the mesenchymal differentiation potential of these cells. Moreover, muscle satellite cells may be a source of ectopic muscle adipocytes, explaining the lipid accumulation often observed in aged skeletal muscle (sarcopenia and in muscles of patients` with diabetes. Quercetin, a polyphenol, is one of the most abundant flavonoids distributed in edible plants, such as onions and apples, and possesses antioxidant, anticancer, and anti-inflammatory properties. In this study, we examined whether quercetin inhibited the adipogenesis of muscle satellite cells in vitro with primary cells from rat limbs by culture in the presence of quercetin under adipogenic conditions. Morphological observations, Oil Red-O staining results, triglyceride content analysis, and quantitative reverse transcription polymerase chain reaction revealed that quercetin was capable of inhibiting the adipogenic induction of muscle satellite cells into adipocytes in a dose-dependent manner by suppressing the transcript levels of adipogenic markers, such as peroxisome proliferator-activated receptor-γ and fatty acid binding protein 4. Our results suggested that quercetin inhibited the adipogenesis of muscle satellite cells in vitro by suppressing the transcription of adipogenic markers. Keywords: Quercetin, Muscle satellite cell, Differentiation, Intramuscular lipid

Postnatal changes in electromyographic signals during piglet growth, and in relation to muscle fibre types

DEFF Research Database (Denmark)

Andersen, Ninette Kieme; Ravn, L.S.; Guy, J.H.

2008-01-01

This study uses non-invasive evoked surface electromyography (SEMG) to investigate postnatal muscle development in pigs, and to assess any correlation between recorded signal parameters and muscle fibre types in two different skeletal muscles. Four litters (n=43) of Large White x Landrace pigs were...... used. Evoked SEMG mesurements were taken on days 2, 5, 14, 26, 60 and 151 post partum from m. Longissimus dorsi (LD) and on days 14, 26, 60 and 151 post partum from m. Biceps femoris (BF). A third of each litter was slaughtered at days 27, 61 and 153 post partum. Biopsy samples for LD and BF were taken...... to categorize day 5 post partum, whilst for BF significant increases occurred from days 14 to 26 post partum. Fibre type development in both muscles showed a significant decrease in type IIA fibre number (Ptype IIB fibre number (P

Effects of non-fatiguing respiratory muscle loading induced by expiratory flow limitation during strenuous incremental cycle exercise on metabolic stress and circulating natural killer cells.

Science.gov (United States)

Rolland-Debord, Camille; Morelot-Panzini, Capucine; Similowski, Thomas; Duranti, Roberto; Laveneziana, Pierantonio

2017-12-01

Exercise induces release of cytokines and increase of circulating natural killers (NK) lymphocyte during strong activation of respiratory muscles. We hypothesised that non-fatiguing respiratory muscle loading during exercise causes an increase in NK cells and in metabolic stress indices. Heart rate (HR), ventilation (VE), oesophageal pressure (Pes), oxygen consumption (VO 2 ), dyspnoea and leg effort were measured in eight healthy humans (five men and three women, average age of 31 ± 4 years and body weight of 68 ± 10 kg), performing an incremental exercise testing on a cycle ergometer under control condition and expiratory flow limitation (FL) achieved by putting a Starling resistor. Blood samples were obtained at baseline, at peak of exercise and at iso-workload corresponding to that reached at the peak of FL exercise during control exercise. Diaphragmatic fatigue was evaluated by measuring the tension time index of the diaphragm. Respiratory muscle overloading caused an earlier interruption of exercise. Diaphragmatic fatigue did not occur in the two conditions. At peak of flow-limited exercise compared to iso-workload, HR, peak inspiratory and expiratory Pes, NK cells and norepinephrine were significantly higher. The number of NK cells was significantly related to ΔPes (i.e. difference between the most and the less negative Pes) and plasmatic catecholamines. Loading of respiratory muscles is able to cause an increase of NK cells provided that activation of respiratory muscles is intense enough to induce a significant metabolic stress.

miR-378 attenuates muscle regeneration by delaying satellite cell activation and differentiation in mice.

Science.gov (United States)

Zeng, Ping; Han, Wanhong; Li, Changyin; Li, Hu; Zhu, Dahai; Zhang, Yong; Liu, Xiaohong

2016-09-01

Skeletal muscle mass and homeostasis during postnatal muscle development and regeneration largely depend on adult muscle stem cells (satellite cells). We recently showed that global overexpression of miR-378 significantly reduced skeletal muscle mass in mice. In the current study, we used miR-378 transgenic (Tg) mice to assess the in vivo functional effects of miR-378 on skeletal muscle growth and regeneration. Cross-sectional analysis of skeletal muscle tissues showed that the number and size of myofibers were significantly lower in miR-378 Tg mice than in wild-type mice. Attenuated cardiotoxin-induced muscle regeneration in miR-378 Tg mice was found to be associated with delayed satellite cell activation and differentiation. Mechanistically, miR-378 was found to directly target Igf1r in muscle cells both in vitro and in vivo These miR-378 Tg mice may provide a model for investigating the physiological and pathological roles of skeletal muscle in muscle-associated diseases in humans, particularly in sarcopenia. © The Author 2016. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Muscle trigger point therapy in tension-type headache.

Science.gov (United States)

Alonso-Blanco, Cristina; de-la-Llave-Rincón, Ana Isabel; Fernández-de-las-Peñas, César

2012-03-01

Recent evidence suggests that active trigger points (TrPs) in neck and shoulder muscles contribute to tension-type headache. Active TrPs within the suboccipital, upper trapezius, sternocleidomastoid, temporalis, superior oblique and lateral rectus muscles have been associated with chronic and episodic tension-type headache forms. It seems that the pain profile of this headache may be provoked by referred pain from active TrPs in the posterior cervical, head and shoulder muscles. In fact, the presence of active TrPs has been related to a higher degree of sensitization in tension-type headache. Different therapeutic approaches are proposed for proper TrP management. Preliminary evidence indicates that inactivation of TrPs may be effective for the management of tension-type headache, particularly in a subgroup of patients who may respond positively to this approach. Different treatment approaches targeted to TrP inactivation are discussed in the current paper, focusing on tension-type headache. New studies are needed to further delineate the relationship between muscle TrP inactivation and tension-type headache.

Contracture Coupling of Slow Striated Muscle in Non-Ionic Solutions and Replacement of Calcium, Sodium, and Potassium

Science.gov (United States)

Irwin, Richard L.; Hein, Manfred M.

1964-01-01

The development of contracture related to changes of ionic environment (ionic contracture coupling) has been studied in the slowly responding fibers of frog skeletal muscle. When deprived of external ions for 30 minutes by use of solutions of sucrose, mannitol, or glucose, the slow skeletal muscle fibers, but not the fast, develop pronounced and easily reversible contractures. Partial replacement of the non-ionic substance with calcium or sodium reduces the development of the contractures but replacement by potassium does not. The concentration of calcium necessary to prevent contracture induced by a non-ionic solution is greater than that needed to maintain relaxation in ionic solutions. To suppress the non-ionic-induced contractures to the same extent as does calcium requires several fold higher concentrations of sodium. Two types of ionic contracture coupling occur in slow type striated muscle fibers: (a) a calcium deprivation type which develops maximally at full physiological concentration of external sodium, shows a flow rate dependency for the calcium-depriving fluid, and is lessened when the sodium concentration is decreased by replacement with sucrose; (b) a sodium deprivation type which occurs maximally without external sodium, is lessened by increasing the sodium concentration, and has no flow rate dependency for ion deprivation. Both types of contracture are largely prevented by the presence of sufficient calcium. There thus seem to be calcium- and sodium-linked processes at work in the ionic contracture coupling of slow striated muscle. PMID:14127603

Engineered matrices for skeletal muscle satellite cell engraftment and function.

Science.gov (United States)

Han, Woojin M; Jang, Young C; García, Andrés J

2017-07-01

Regeneration of traumatically injured skeletal muscles is severely limited. Moreover, the regenerative capacity of skeletal muscle declines with aging, further exacerbating the problem. Recent evidence supports that delivery of muscle satellite cells to the injured muscles enhances muscle regeneration and reverses features of aging, including reduction in muscle mass and regenerative capacity. However, direct delivery of satellite cells presents a challenge at a translational level due to inflammation and donor cell death, motivating the need to develop engineered matrices for muscle satellite cell delivery. This review will highlight important aspects of satellite cell and their niche biology in the context of muscle regeneration, and examine recent progresses in the development of engineered cell delivery matrices designed for skeletal muscle regeneration. Understanding the interactions of muscle satellite cells and their niche in both native and engineered systems is crucial to developing muscle pathology-specific cell- and biomaterial-based therapies. Copyright © 2016 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Adenovirus-assisted lipofection: efficient in vitro gene transfer of luciferase and cytosine deaminase to human smooth muscle cells.

Science.gov (United States)

Kreuzer, J; Denger, S; Reifers, F; Beisel, C; Haack, K; Gebert, J; Kübler, W

1996-07-01

Smooth muscle cells (SMC) are a central cell type involved in multiple processes of coronary artery diseases including restenosis and therefore are major target cells for different aspects of gene transfer. Previous attempts to transfect primary arterial cells using different techniques like liposomes, CaPO4 and electroporation resulted in only low transfection efficiency. The development of recombinant adenoviruses dramatically improved the delivery of foreign genes into different cell types including SMC. However, cloning and identification of recombinants remain difficult and time-consuming techniques. The present study demonstrates that a complex consisting of reporter plasmid encoding firefly luciferase (pLUC), polycationic liposomes and replication-deficient adenovirus was able to yield very high in vitro transfection of primary human smooth muscle cells under optimized conditions. The technique of adenovirus-assisted lipofection (AAL) increases transfer and expression of plasmid DNA in human smooth muscle cells in vitro up to 1000-fold compared to lipofection. To verify the applicability of AAL for gene transfer into human smooth muscle cells we studied a gene therapy approach to suppress proliferation of SMC in vitro, using the prokaryotic cytosine deaminase gene (CD) which enables transfected mammalian cells to deaminate 5-fluorocytosine (5-FC) to the highly toxic 5-fluorouracil (5-FU). The effect of a transient CD expression on RNA synthesis was investigated by means of a cotransfection with a RSV-CD expression plasmid and the luciferase reporter plasmid. Western blot analysis demonstrated high expression of CD protein in transfected SMC. Cotransfected SMC demonstrated two-fold less luciferase activity in the presence of 5-FC (5 mmol/l) after 48 h compared to cells transfected with a non-CD coding plasmid. The data demonstrate that a transient expression of CD could be sufficient to reduce the capacity of protein synthesis in human SMC. This simple and

Adenosine formation in contracting primary rat skeletal muscle cells and endothelial cells in culture

DEFF Research Database (Denmark)

Hellsten, Ylva; Frandsen, Ulrik

1997-01-01

1. The present study examined the capacity for adenosine formation, uptake and metabolism in contracting primary rat muscle cells and in microvascular endothelial cells in culture. 2. Strong and moderate electrical simulation of skeletal muscle cells led to a significantly greater increase....... 3. Addition of microvascular endothelial cells to the cultured skeletal muscle cells enhanced the contraction-induced accumulation of extracellular adenosine (P Skeletal muscle cells were...... in the extracellular adenosine concentration (421 +/- 91 and 235 +/- 30 nmol (g protein)-1, respectively; P muscle cells (161 +/- 20 nmol (g protein)-1). The ATP concentration was lower (18%; P contracted, but not in the moderately contracted muscle cells...

Myogenic Progenitor Cells Control Extracellular Matrix Production by Fibroblasts during Skeletal Muscle Hypertrophy.

Science.gov (United States)

Fry, Christopher S; Kirby, Tyler J; Kosmac, Kate; McCarthy, John J; Peterson, Charlotte A

2017-01-05

Satellite cells, the predominant stem cell population in adult skeletal muscle, are activated in response to hypertrophic stimuli and give rise to myogenic progenitor cells (MPCs) within the extracellular matrix (ECM) that surrounds myofibers. This ECM is composed largely of collagens secreted by interstitial fibrogenic cells, which influence satellite cell activity and muscle repair during hypertrophy and aging. Here we show that MPCs interact with interstitial fibrogenic cells to ensure proper ECM deposition and optimal muscle remodeling in response to hypertrophic stimuli. MPC-dependent ECM remodeling during the first week of a growth stimulus is sufficient to ensure long-term myofiber hypertrophy. MPCs secrete exosomes containing miR-206, which represses Rrbp1, a master regulator of collagen biosynthesis, in fibrogenic cells to prevent excessive ECM deposition. These findings provide insights into how skeletal stem and progenitor cells interact with other cell types to actively regulate their extracellular environments for tissue maintenance and adaptation. Copyright © 2017 Elsevier Inc. All rights reserved.

Single Stem Cell Imaging and Analysis Reveals Telomere Length Differences in Diseased Human and Mouse Skeletal Muscles

Directory of Open Access Journals (Sweden)

Elisia D. Tichy

2017-10-01

Full Text Available Muscle stem cells (MuSCs contribute to muscle regeneration following injury. In many muscle disorders, the repeated cycles of damage and repair lead to stem cell dysfunction. While telomere attrition may contribute to aberrant stem cell functions, methods to accurately measure telomere length in stem cells from skeletal muscles have not been demonstrated. Here, we have optimized and validated such a method, named MuQ-FISH, for analyzing telomere length in MuSCs from either mice or humans. Our analysis showed no differences in telomere length between young and aged MuSCs from uninjured wild-type mice, but MuSCs isolated from young dystrophic mice exhibited significantly shortened telomeres. In corroboration, we demonstrated that telomere attrition is present in human dystrophic MuSCs, which underscores its importance in diseased regenerative failure. The robust technique described herein provides analysis at a single-cell resolution and may be utilized for other cell types, especially rare populations of cells.

Assessment of satellite cell number and activity status in human skeletal muscle biopsies

DEFF Research Database (Denmark)

Mackey, Abigail; Kjaer, Michael; Charifi, Nadia

2009-01-01

The primary aim of our study was to validate the assessment of myonuclear and satellite cell number in biopsies from human skeletal muscle. We found that 25 type I and 25 type II fibers are sufficient to estimate the mean number of myonuclei per fiber. In contrast, the assessment of satellite cells...

Effect of ionizing radiation on human skeletal muscle precursor cells

International Nuclear Information System (INIS)

Jurdana, Mihaela; Cemazar, Maja; Pegan, Katarina; Mars, Tomaz

2013-01-01

Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures. Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin – 6 (IL-6) release and stress response detected by the heat shock protein (HSP) level, while long term effects were followed by proliferation capacity and cell death. Compared with non-irradiated control and cells treated with inhibitor of cell proliferation Ara C, myoblast proliferation decreased 72 h post-irradiation, this effect was more pronounced with increasing doses. Post-irradiation myoblast survival determined by measurement of released LDH enzyme activity revealed increased activity after exposure to irradiation. The acute response of myoblasts to lower doses of irradiation (4 and 6 Gy) was decreased secretion of constitutive IL-6. Higher doses of irradiation triggered a stress response in myoblasts, determined by increased levels of stress markers (HSPs 27 and 70). Our results show that myoblasts are sensitive to irradiation in terms of their proliferation capacity and capacity to secret IL-6. Since myoblast proliferation and differentiation are a key stage in muscle regeneration, this effect of irradiation needs to be taken in account, particularly in certain clinical conditions

Defining the role of mesenchymal stromal cells on the regulation of matrix metalloproteinases in skeletal muscle cells

International Nuclear Information System (INIS)

Sassoli, Chiara; Nosi, Daniele; Tani, Alessia; Chellini, Flaminia; Mazzanti, Benedetta; Quercioli, Franco; Zecchi-Orlandini, Sandra; Formigli, Lucia

2014-01-01

Recent studies indicate that mesenchymal stromal cell (MSC) transplantation improves healing of injured and diseased skeletal muscle, although the mechanisms of benefit are poorly understood. In the present study, we investigated whether MSCs and/or their trophic factors were able to regulate matrix metalloproteinase (MMP) expression and activity in different cells of the muscle tissue. MSCs in co-culture with C2C12 cells or their conditioned medium (MSC-CM) up-regulated MMP-2 and MMP-9 expression and function in the myoblastic cells; these effects were concomitant with the down-regulation of the tissue inhibitor of metalloproteinases (TIMP)-1 and -2 and with increased cell motility. In the single muscle fiber experiments, MSC-CM administration increased MMP-2/9 expression in Pax-7 + satellite cells and stimulated their mobilization, differentiation and fusion. The anti-fibrotic properties of MSC-CM involved also the regulation of MMPs by skeletal fibroblasts and the inhibition of their differentiation into myofibroblasts. The treatment with SB-3CT, a potent MMP inhibitor, prevented in these cells, the decrease of α-smooth actin and type-I collagen expression induced by MSC-CM, suggesting that MSC-CM could attenuate the fibrogenic response through mechanisms mediated by MMPs. Our results indicate that growth factors and cytokines released by these cells may modulate the fibrotic response and improve the endogenous mechanisms of muscle repair/regeneration. - Highlights: • MSC-CM contains paracrine factors that up-regulate MMP expression and function in different skeletal muscle cells. • MSC-CM promotes myoblast and satellite cell migration, proliferation and differentiation. • MSC-CM negatively interferes with fibroblast-myoblast transition in primary skeletal fibroblasts. • Paracrine factors from MSCs modulate the fibrotic response and improve the endogenous mechanisms of muscle regeneration

Defining the role of mesenchymal stromal cells on the regulation of matrix metalloproteinases in skeletal muscle cells

Energy Technology Data Exchange (ETDEWEB)

Sassoli, Chiara; Nosi, Daniele; Tani, Alessia; Chellini, Flaminia [Dept. of Experimental and Clinical Medicine—Section of Anatomy and Histology, University of Florence, Largo Brambilla, 3, 50134, Florence (Italy); Mazzanti, Benedetta [Dept. of Experimental and Clinical Medicine—Section of Haematology, University of Florence, Largo Brambilla, 3, 50134, Florence (Italy); Quercioli, Franco [CNR-National Institute of Optics (INO), Largo Enrico Fermi 6, 50125 Arcetri-Florence (Italy); Zecchi-Orlandini, Sandra [Dept. of Experimental and Clinical Medicine—Section of Anatomy and Histology, University of Florence, Largo Brambilla, 3, 50134, Florence (Italy); Formigli, Lucia, E-mail: formigli@unifi.it [Dept. of Experimental and Clinical Medicine—Section of Anatomy and Histology, University of Florence, Largo Brambilla, 3, 50134, Florence (Italy)

2014-05-01

Recent studies indicate that mesenchymal stromal cell (MSC) transplantation improves healing of injured and diseased skeletal muscle, although the mechanisms of benefit are poorly understood. In the present study, we investigated whether MSCs and/or their trophic factors were able to regulate matrix metalloproteinase (MMP) expression and activity in different cells of the muscle tissue. MSCs in co-culture with C2C12 cells or their conditioned medium (MSC-CM) up-regulated MMP-2 and MMP-9 expression and function in the myoblastic cells; these effects were concomitant with the down-regulation of the tissue inhibitor of metalloproteinases (TIMP)-1 and -2 and with increased cell motility. In the single muscle fiber experiments, MSC-CM administration increased MMP-2/9 expression in Pax-7{sup +} satellite cells and stimulated their mobilization, differentiation and fusion. The anti-fibrotic properties of MSC-CM involved also the regulation of MMPs by skeletal fibroblasts and the inhibition of their differentiation into myofibroblasts. The treatment with SB-3CT, a potent MMP inhibitor, prevented in these cells, the decrease of α-smooth actin and type-I collagen expression induced by MSC-CM, suggesting that MSC-CM could attenuate the fibrogenic response through mechanisms mediated by MMPs. Our results indicate that growth factors and cytokines released by these cells may modulate the fibrotic response and improve the endogenous mechanisms of muscle repair/regeneration. - Highlights: • MSC-CM contains paracrine factors that up-regulate MMP expression and function in different skeletal muscle cells. • MSC-CM promotes myoblast and satellite cell migration, proliferation and differentiation. • MSC-CM negatively interferes with fibroblast-myoblast transition in primary skeletal fibroblasts. • Paracrine factors from MSCs modulate the fibrotic response and improve the endogenous mechanisms of muscle regeneration.

Effective fiber hypertrophy in satellite cell-depleted skeletal muscle

Science.gov (United States)

McCarthy, John J.; Mula, Jyothi; Miyazaki, Mitsunori; Erfani, Rod; Garrison, Kelcye; Farooqui, Amreen B.; Srikuea, Ratchakrit; Lawson, Benjamin A.; Grimes, Barry; Keller, Charles; Van Zant, Gary; Campbell, Kenneth S.; Esser, Karyn A.; Dupont-Versteegden, Esther E.; Peterson, Charlotte A.

2011-01-01

An important unresolved question in skeletal muscle plasticity is whether satellite cells are necessary for muscle fiber hypertrophy. To address this issue, a novel mouse strain (Pax7-DTA) was created which enabled the conditional ablation of >90% of satellite cells in mature skeletal muscle following tamoxifen administration. To test the hypothesis that satellite cells are necessary for skeletal muscle hypertrophy, the plantaris muscle of adult Pax7-DTA mice was subjected to mechanical overload by surgical removal of the synergist muscle. Following two weeks of overload, satellite cell-depleted muscle showed the same increases in muscle mass (approximately twofold) and fiber cross-sectional area with hypertrophy as observed in the vehicle-treated group. The typical increase in myonuclei with hypertrophy was absent in satellite cell-depleted fibers, resulting in expansion of the myonuclear domain. Consistent with lack of nuclear addition to enlarged fibers, long-term BrdU labeling showed a significant reduction in the number of BrdU-positive myonuclei in satellite cell-depleted muscle compared with vehicle-treated muscle. Single fiber functional analyses showed no difference in specific force, Ca2+ sensitivity, rate of cross-bridge cycling and cooperativity between hypertrophied fibers from vehicle and tamoxifen-treated groups. Although a small component of the hypertrophic response, both fiber hyperplasia and regeneration were significantly blunted following satellite cell depletion, indicating a distinct requirement for satellite cells during these processes. These results provide convincing evidence that skeletal muscle fibers are capable of mounting a robust hypertrophic response to mechanical overload that is not dependent on satellite cells. PMID:21828094

Preferential type II muscle fiber damage from plyometric exercise.

Science.gov (United States)

Macaluso, Filippo; Isaacs, Ashwin W; Myburgh, Kathryn H

2012-01-01

Plyometric training has been successfully used in different sporting contexts. Studies that investigated the effect of plyometric training on muscle morphology are limited, and results are controversial with regard to which muscle fiber type is mainly affected. To analyze the skeletal muscle structural and ultrastructural change induced by an acute bout of plyometric exercise to determine which type of muscle fibers is predominantly damaged. Descriptive laboratory study. Research laboratory. Eight healthy, untrained individuals (age = 22 ± 1 years, height = 179.2 ± 6.4 cm, weight = 78.9 ± 5.9 kg). Participants completed an acute bout of plyometric exercise (10 sets of 10 squat-jumps with a 1-minute rest between sets). Blood samples were collected 9 days and immediately before and 6 hours and 1, 2, and 3 days after the acute intervention. Muscle samples were collected 9 days before and 3 days after the exercise intervention. Blood samples were analyzed for creatine kinase activity. Muscle biopsies were analyzed for damage using fluorescent and electron transmission microscopy. Creatine kinase activity peaked 1 day after the exercise bout (529.0 ± 317.8 U/L). Immunofluorescence revealed sarcolemmal damage in 155 of 1616 fibers analyzed. Mainly fast-twitch fibers were damaged. Within subgroups, 7.6% of type I fibers, 10.3% of type IIa fibers, and 14.3% of type IIx fibers were damaged as assessed by losses in dystrophin staining. Similar damage was prevalent in IIx and IIa fibers. Electron microscopy revealed clearly distinguishable moderate and severe sarcomere damage, with damage quantifiably predominant in type II muscle fibers of both the glycolytic and oxidative subtypes (86% and 84%, respectively, versus only 27% of slow-twitch fibers). We provide direct evidence that a single bout of plyometric exercise affected mainly type II muscle fibers.

Painful unilateral temporalis muscle enlargement: reactive masticatory muscle hypertrophy.

Science.gov (United States)

Katsetos, Christos D; Bianchi, Michael A; Jaffery, Fizza; Koutzaki, Sirma; Zarella, Mark; Slater, Robert

2014-06-01

An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.

Altered fibre types in gastrocnemius muscle of high wheel-running selected mice with mini-muscle phenotypes.

Science.gov (United States)

Guderley, Helga; Joanisse, Denis R; Mokas, Sophie; Bilodeau, Geneviève M; Garland, Theodore

2008-03-01

Selective breeding of mice for high voluntary wheel running has favoured characteristics that facilitate sustained, aerobically supported activity, including a "mini-muscle" phenotype with markedly reduced hind limb muscle mass, increased mass-specific activities of oxidative enzymes, decreased % myosin heavy chain IIb, and, in the medial gastrocnemius, reduced twitch speed, reduced mass-specific isotonic power, and increased fatigue resistance. To evaluate whether selection has altered fibre type expression in mice with either "mini" or normal muscle phenotypes, we examined fibre types of red and white gastrocnemius. In both the medial and lateral gastrocnemius, the mini-phenotype increased activities of oxidative enzymes and decreased activities of glycolytic enzymes. In red muscle samples, the mini-phenotype markedly changed fibre types, with the % type I and type IIA fibres and the surface area of type IIA fibres increasing; in addition, mice from selected lines in general had an increased % type IIA fibres and larger type I fibres as compared with mice from control lines. White muscle samples from mini-mice showed dramatic structural alterations, with an atypical distribution of extremely small, unidentifiable fibres surrounded by larger, more oxidative fibres than normally present in white muscle. The increased proportion of oxidative fibres and these atypical small fibres together may explain the reduced mass and increased mitochondrial enzyme activities in mini-muscles. These and previous results demonstrate that extension of selective breeding beyond the time when the response of the selected trait (i.e. distance run) has levelled off can still modify the mechanistic underpinnings of this behaviour.

Healthy and diseased striated muscle studied by analytical scanning electron microscopy with special reference to fibre type

International Nuclear Information System (INIS)

Wroblewski, R.

1982-01-01

X-ray microanalytical investigations of striated muscles in the scanning electron microscope are reviewed. The main part of the studies was performed on cryosections cut with a conventional cryostat operating at -20 degrees C to -40 degrees C. The preparation procedure including different types of attachment of the sections to the specimen holder is described in detail. The elemental changes in muscle are related to the muscle fibre type as demonstrated by histochemical methods or to histochemically demonstrated inclusions in diseased muscles. This is of great importance, because muscle disorders are often characterised by selective involvement of different muscle fibre types. The preparation methods of muscle for analytical scanning electron microscopy and the obtained results are compared with studies performed on thin cryo and epoxy sections, analysed in the transmission and scanning-transmission electron microscope. It is evident that X-ray microanalysis performed on thick cryosections provide a quick survey of the elemental composition of whole cells, and should be followed in interesting cases by close examination on the organelle level studied in thin cryosections in the transmission and scanning-transmission electron microscope

Aortic smooth muscle cell proteoglycan synthesis in relation to atherosclerosis

International Nuclear Information System (INIS)

Edwards, I.J.

1989-01-01

Proteoglycans (PG) are implicated in atherogenesis by their effects on tissue permeability and cell proliferation and their interaction with plasma low density lipoproteins. Using the pigeon model in which an atherosclerosis-susceptible (WC) and -resistant (SR) breed can be compared, PG synthesis by cultured aortic smooth muscle cells was examined by the use of [ 35 S]-sodium sulfate and [ 3 H]-serine or [ 3 H]-glucosamine as labeling precursors. In both SR and WC cells, the majority of newly synthesized PG were secreted into the media. Chondroitin sulfate (CS) PG and dermatan sulfate (DS) PG were the major PG produced. Total PG production was consistently lower in WC compared to SR cultures due in part to reduce PG synthesis but also to degradation of newly synthesized PG. Since increased DS-PG accompanines atherosclerosis progression, experiments were designed to test the hypothesis that macrophages modulate smooth muscle cell metabolism to cause increase DS-PG production. Cultured WC aortic smooth muscle cells were exposed to the media of cholesteryl ester-loaded pigeon peritoneal macrophages or a macrophage cell line P388D1 and the production of PG examined. Increasing concentration of conditioned media from both types of macrophages caused increased incorporation of 35 S-sulfate into secreted PG, but no change in cell-associated PG. Lipopolysaccharide activation of P388D1 cells enhanced the effect

Non-myogenic Contribution to Muscle Development and Homeostasis: The Role of Connective Tissues.

Science.gov (United States)

Nassari, Sonya; Duprez, Delphine; Fournier-Thibault, Claire

2017-01-01

Skeletal muscles belong to the musculoskeletal system, which is composed of bone, tendon, ligament and irregular connective tissue, and closely associated with motor nerves and blood vessels. The intrinsic molecular signals regulating myogenesis have been extensively investigated. However, muscle development, homeostasis and regeneration require interactions with surrounding tissues and the cellular and molecular aspects of this dialogue have not been completely elucidated. During development and adult life, myogenic cells are closely associated with the different types of connective tissue. Connective tissues are defined as specialized (bone and cartilage), dense regular (tendon and ligament) and dense irregular connective tissue. The role of connective tissue in muscle morphogenesis has been investigated, thanks to the identification of transcription factors that characterize the different types of connective tissues. Here, we review the development of the various connective tissues in the context of the musculoskeletal system and highlight their important role in delivering information necessary for correct muscle morphogenesis, from the early step of myoblast differentiation to the late stage of muscle maturation. Interactions between muscle and connective tissue are also critical in the adult during muscle regeneration, as impairment of the regenerative potential after injury or in neuromuscular diseases results in the progressive replacement of the muscle mass by fibrotic tissue. We conclude that bi-directional communication between muscle and connective tissue is critical for a correct assembly of the musculoskeletal system during development as well as to maintain its homeostasis in the adult.

Bimodal effect on pancreatic β-cells of secretory products from normal or insulin-resistant human skeletal muscle

DEFF Research Database (Denmark)

Bouzakri, Karim; Plomgaard, Peter; Berney, Thierry

2011-01-01

Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells.......Type 2 diabetes is characterized by insulin resistance with a relative deficiency in insulin secretion. This study explored the potential communication between insulin-resistant human skeletal muscle and primary (human and rat) β-cells....

Primary non-Hodgkin lymphoma of skeletal muscle: imaging findings

International Nuclear Information System (INIS)

Zhou Liangping; Peng Weijun; Tang Feng; Mao Jian; Yang Wentao

2006-01-01

Objective: To analyze the imaging manifestations of primary non-Hodgkin lymphoma of skeletal muscle and improve the recognition of this rare disease. Methods: Five cases of primary non- Hodgkin lymphoma of skeletal muscle proved pathologically underwent imaging exam, including MRI and CT in 3 cases, only MRI in 1 case, only CT in 1 case, X-ray in 2 cases and bone scintigraphy in 2 cases. Results: Diffuse enlargements of involved muscle with presentation of overall configuration were observed in all five cases. All 4 cases manifested as homogeneous soft masses, which is isoattenuating to normal muscle on unenhanced CT images. After intravenous injection of contrast media, the masses enhanced homogeneously and slightly (2 cases) or moderately (1 case) on CT images. The lesions were homogenous and had isointense or slightly low signal intensity compared with that of uninvolved muscle on T 1 -weighted images and high signal intensity on T 2 -weighted images. After intravenous injection of contrast media, all 2 cases enhanced homogeneously and moderately with the enhanced signal intensity of involved muscle greatly higher than that of uninvolved muscle on MR images. Two cases of X-ray plain showed no destruction of bone and 2 cases of bone scintigraphy exams showed increased radiotracer uptake of involved muscle with no infiltration of bone marrow. Conclusion: There are several characteristics on the imaging of primary non-Hodgkin lymphoma of skeletal muscle. MRI is the optimal imaging method for the diagnosis of this disease. (authors)

Morphometric analysis of somatotropic cells of the adenohypophysis and muscle fibers of the psoas muscle in the process of aging in humans.

Science.gov (United States)

Antić, Vladimir M; Stefanović, Natalija; Jovanović, Ivan; Antić, Milorad; Milić, Miroslav; Krstić, Miljan; Kundalić, Braca; Milošević, Verica

2015-07-01

The aim of this research was to quantify changes of the adenohypophyseal somatotropes and types 1 and 2 muscle fibers with aging, as well as to establish mutual interactions and correlations with age. Material was samples of hypophysis and psoas major muscle of 27 cadavers of both genders, aged from 30 to 90 years. Adenohypophyseal and psoas major tissue sections were immunohistochemically processed and stained by anti-human growth hormone and anti-fast myosin antibodies, respectively. Morphometric analysis was performed by ImageJ. Results of morphometric analysis showed a significant increase in the somatotrope area, and significant decrease in somatotrope volume density and nucleocytoplasmic ratio with age. Cross-sectional areas of types 1 and 2, and volume density of type 2 muscle fibers decreased significantly with age. One Way ANOVA showed that the latter cited changes in the somatotropes and types 1 and 2 muscle fibers mostly become significant after the age of 70. Significant positive correlation was observed between the area of the somatotropes and volume density of type 2 muscle fibers. A significant negative correlation was detected between the nucleocytoplasmic ratio of the somatotropes and cross-sectional areas of types 1 and 2 muscle fibers. So, it can be concluded that after the age of 70, there is significant loss of the anterior pituitary's somatotropes associated with hypertrophy and possible functional decline of the remained cells. Age-related changes in the somatotropes are correlated with the simultaneous atrophy of type 1, as well as with the atrophy and loss of type 2 muscle fibers. Copyright © 2015 Elsevier GmbH. All rights reserved.

Non-muscle-invasive bladder cancer

DEFF Research Database (Denmark)

Malmström, Per-Uno; Agrawal, Sachin; Bläckberg, Mats

2017-01-01

The management of non-muscle-invasive bladder cancer (NMIBC) has evolved from the first reports on bladder endoscopy and transurethral resection to the introduction of adjuvant intravesical treatment. However, disease recurrence and progression remain an ongoing risk, placing a heavy burden...

Effects of extracts of denervated muscles on the morphology of cultured muscle cells

NARCIS (Netherlands)

Hooisma, J.; Krijger, J.de; Groot, D.M.G. de

1981-01-01

Previously tropic effects of extracts from whole chick embryos and from innervated muscles on cultured muscle cells were described. The present study demonstrated similar effects of extracts from 10-days denervated chick muscles. Extracts from innervated as well as from denervated muscles

Stem Cells for Skeletal Muscle Tissue Engineering.

Science.gov (United States)

Pantelic, Molly N; Larkin, Lisa M

2018-04-19

Volumetric muscle loss (VML) is a debilitating condition wherein muscle loss overwhelms the body's normal physiological repair mechanism. VML is particularly common among military service members who have sustained war injuries. Because of the high social and medical cost associated with VML and suboptimal current surgical treatments, there is great interest in developing better VML therapies. Skeletal muscle tissue engineering (SMTE) is a promising alternative to traditional VML surgical treatments that use autogenic tissue grafts, and rather uses isolated stem cells with myogenic potential to generate de novo skeletal muscle tissues to treat VML. Satellite cells are the native precursors to skeletal muscle tissue, and are thus the most commonly studied starting source for SMTE. However, satellite cells are difficult to isolate and purify, and it is presently unknown whether they would be a practical source in clinical SMTE applications. Alternative myogenic stem cells, including adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, perivascular stem cells, umbilical cord mesenchymal stem cells, induced pluripotent stem cells, and embryonic stem cells, each have myogenic potential and have been identified as possible starting sources for SMTE, although they have yet to be studied in detail for this purpose. These alternative stem cell varieties offer unique advantages and disadvantages that are worth exploring further to advance the SMTE field toward highly functional, safe, and practical VML treatments. The following review summarizes the current state of satellite cell-based SMTE, details the properties and practical advantages of alternative myogenic stem cells, and offers guidance to tissue engineers on how alternative myogenic stem cells can be incorporated into SMTE research.

Acute compartment syndrome after muscle rupture in a non-athlete.

OpenAIRE

Thennavan, A S; Funk, L; Volans, A P

1999-01-01

Acute compartment syndrome after muscle rupture, although rare, is a limb threatening condition, which warrants emergency treatment. The case of acute compartment syndrome secondary to a gastrocnemius muscle tear of the right lower leg, in a non-athlete is reported. To our knowledge, this is the only description of acute compartment syndrome due to muscle rupture in a non-athlete.

Myositis in Griscelli syndrome type 2 treated with hematopoietic cell transplantation

DEFF Research Database (Denmark)

Born, Alfred Peter; Müller, Klaus; Marquart, Hanne Vibeke

2010-01-01

Griscelli syndrome is an autosomal recessive disorder characterized by pigmentary dilution and is occasionally associated with a hemophagocytic syndrome (type 2). We present a 13-year-old girl with Griscelli syndrome type 2, who developed a hemophagocytic syndrome along with marked muscle weakness...... and elevated plasma creatine kinase. Muscle biopsy showed massive inflammatory changes in some fascicles, while other fascicles were relatively spared. Clinical symptoms and biopsy changes resolved after immunosuppression and allogeneic hematopoietic cell transplantation. Our results suggest that muscle...

The muscle stem cell niche : regulation of satellite cells during regeneration

NARCIS (Netherlands)

Boonen, K.J.M.; Post, M.J.

2008-01-01

Satellite cells are considered to be adult skeletal muscle stem cells. Their ability to regenerate large muscle defects is highly dependent on their specific niche. When these cells are cultured in vitro, the loss of this niche leads to a loss of proliferative capacity and defective regeneration

Sensitivity of different types of fibres in rabbit skeletal muscle to pneumatic compression by tourniquet and to ischaemia.

Science.gov (United States)

Fridén, J; Pedowitz, R A; Thornell, L E

1994-06-01

Morphometric properties (distribution of types of fibre and fibre areas) in the non-necrotic regions of four different rabbit muscles (superficial portions of semimembranosus, biceps femoris, tibialis anterior, and soleus muscles) were measured 48 hours after a tourniquet had been applied around the thigh for two hours at either 125 or 350 mmHg. There was an considerable increase of the relative numbers of both large and small fibres as well as changes in the proportions of the types of fibre. The most dramatic percentage change in type of fibre was in the semimembranosus when compressed at 350 mmHg, which showed an increase of the relative frequency of fibres with type 2AB staining characteristics from 10.2% to 18.0% (p < 0.001). Extreme changes in fibre area were found exclusively in semimembranosus and biceps femoris. Most fibres of abnormal size were of type 2, type 2B fibre areas being the most affected. This study shows that morphometry is a valuable tool in the assessment of the more subtle indications of injury. Compression and ischaemia together have a more dramatic effect on muscle morphology and morphometric properties in the non-necrotic regions than ischaemia alone. These data also show that muscles are differentially sensitive to compression and ischaemia. This information may be useful into the understanding of more complex functional deficits observed after the use of tourniquet.

Physical activity counteracts tumor cell growth in colon carcinoma C26-injected muscles: an interim report

Directory of Open Access Journals (Sweden)

Charlotte Hiroux

2016-06-01

Full Text Available Skeletal muscle tissue is a rare site of tumor metastasis but is the main target of the degenerative processes occurring in cancer-associated cachexia syndrome. Beneficial effects of physical activity in counteracting cancer-related muscle wasting have been described in the last decades. Recently it has been shown that, in tumor xeno-transplanted mouse models, physical activity is able to directly affect tumor growth by modulating inflammatory responses in the tumor mass microenvironment. Here, we investigated the effect of physical activity on tumor cell growth in colon carcinoma C26 cells injected tibialis anterior muscles of BALB/c mice. Histological analyses revealed that 4 days of voluntary wheel running significantly counteracts tumor cell growth in C26-injected muscles compared to the non-injected sedentary controls. Since striated skeletal muscle tissue is the site of voluntary contraction, our results confirm that physical activity can also directly counteract tumor cell growth in a metabolically active tissue that is usually not a target for metastasis.

PEDF-derived peptide promotes skeletal muscle regeneration through its mitogenic effect on muscle progenitor cells.

Science.gov (United States)

Ho, Tsung-Chuan; Chiang, Yi-Pin; Chuang, Chih-Kuang; Chen, Show-Li; Hsieh, Jui-Wen; Lan, Yu-Wen; Tsao, Yeou-Ping

2015-08-01

In response injury, intrinsic repair mechanisms are activated in skeletal muscle to replace the damaged muscle fibers with new muscle fibers. The regeneration process starts with the proliferation of satellite cells to give rise to myoblasts, which subsequently differentiate terminally into myofibers. Here, we investigated the promotion effect of pigment epithelial-derived factor (PEDF) on muscle regeneration. We report that PEDF and a synthetic PEDF-derived short peptide (PSP; residues Ser(93)-Leu(112)) induce satellite cell proliferation in vitro and promote muscle regeneration in vivo. Extensively, soleus muscle necrosis was induced in rats by bupivacaine, and an injectable alginate gel was used to release the PSP in the injured muscle. PSP delivery was found to stimulate satellite cell proliferation in damaged muscle and enhance the growth of regenerating myofibers, with complete regeneration of normal muscle mass by 2 wk. In cell culture, PEDF/PSP stimulated C2C12 myoblast proliferation, together with a rise in cyclin D1 expression. PEDF induced the phosphorylation of ERK1/2, Akt, and STAT3 in C2C12 myoblasts. Blocking the activity of ERK, Akt, or STAT3 with pharmacological inhibitors attenuated the effects of PEDF/PSP on the induction of C2C12 cell proliferation and cyclin D1 expression. Moreover, 5-bromo-2'-deoxyuridine pulse-labeling demonstrated that PEDF/PSP stimulated primary rat satellite cell proliferation in myofibers in vitro. In summary, we report for the first time that PSP is capable of promoting the regeneration of skeletal muscle. The signaling mechanism involves the ERK, AKT, and STAT3 pathways. These results show the potential utility of this PEDF peptide for muscle regeneration. Copyright © 2015 the American Physiological Society.

Measuring phospholipase D activity in insulin-secreting pancreatic beta-cells and insulin-responsive muscle cells and adipocytes.

Science.gov (United States)

Cazzolli, Rosanna; Huang, Ping; Teng, Shuzhi; Hughes, William E

2009-01-01

Phospholipase D (PLD) is an enzyme producing phosphatidic acid and choline through hydrolysis of phosphatidylcholine. The enzyme has been identified as a member of a variety of signal transduction cascades and as a key regulator of numerous intracellular vesicle trafficking processes. A role for PLD in regulating glucose homeostasis is emerging as the enzyme has recently been identified in events regulating exocytosis of insulin from pancreatic beta-cells and also in insulin-stimulated glucose uptake through controlling GLUT4 vesicle exocytosis in muscle and adipose tissue. We present methodologies for assessing cellular PLD activity in secretagogue-stimulated insulin-secreting pancreatic beta-cells and also insulin-stimulated adipocyte and muscle cells, two of the principal insulin-responsive cell types controlling blood glucose levels.

Quantitative analysis of immune cell subset infiltration of supraspinatus muscle after severe rotator cuff injury.

Science.gov (United States)

Krieger, J R; Tellier, L E; Ollukaren, M T; Temenoff, J S; Botchwey, E A

2017-06-01

Rotator cuff tears cause muscle degeneration that is characterized by myofiber atrophy, fatty infiltration, and fibrosis and is minimally responsive to current treatment options. The underlying pathogenesis of rotator cuff muscle degeneration remains to be elucidated, and increasing evidence implicates immune cell infiltration as a significant factor. Because immune cells are comprised of highly heterogeneous subpopulations that exert divergent effects on injured tissue, understanding trafficking and accumulation of immune subpopulations may hold the key to more effective therapies. The present study quantifies subpopulations of immune cells infiltrating the murine supraspinatus muscle after severe rotator cuff injury that includes tenotomy and denervation. Rotator cuff injury stimulates dramatic infiltration of mononuclear phagocytes, enriches mononuclear phagocytes in non-classical subpopulations, and enriches T lymphocytes in T H and T reg subpopulations. The combination of tenotomy plus denervation significantly increases mononuclear phagocyte infiltration, enriches macrophages in the non-classical subpopulation, and decreases T lymphocyte enrichment in T H cells compared to tenotomy alone. Depletion of circulating monocytes via liposomal clodronate accelerates supraspinatus atrophy after tenotomy and denervation. The study may aid rational design of immunologically smart therapies that harness immune cells to enhance outcomes after rotator cuff tears.

Type 2 diabetes impairs venous, but not arterial smooth muscle cell function: Possible role of differential RhoA activity

Energy Technology Data Exchange (ETDEWEB)

Riches, Kirsten [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Warburton, Philip [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); O’Regan, David J. [Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Department of Cardiac Surgery, The Yorkshire Heart Centre, Leeds General Infirmary, Leeds (United Kingdom); Turner, Neil A. [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom); Porter, Karen E., E-mail: medkep@leeds.ac.uk [Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics (LIGHT), University of Leeds, Leeds (United Kingdom); Multidisciplinary Cardiovascular Research Centre (MCRC), University of Leeds, Leeds (United Kingdom)

2014-04-15

Background/purpose: Coronary heart disease is the leading cause of morbidity in patients with type 2 diabetes mellitus (T2DM), frequently resulting in a requirement for coronary revascularization using the internal mammary artery (IMA) or saphenous vein (SV). Patency rates of SV grafts are inferior to IMA and further impaired by T2DM whilst IMA patencies appear similar in both populations. Smooth muscle cells (SMC) play a pivotal role in graft integration; we therefore examined the phenotype and proliferative function of IMA- and SV-SMC isolated from non-diabetic (ND) patients or those diagnosed with T2DM. Methods/materials: SMC were cultured from fragments of SV or IMA. Morphology was analyzed under light microscopy (spread cell area measurements) and confocal microscopy (F-actin staining). Proliferation was analyzed by cell counting. Levels of RhoA mRNA, protein and activity were measured by real-time RT-PCR, western blotting and G-LISA respectively. Results: IMA-SMC from T2DM and ND patients were indistinguishable in both morphology and function. By comparison, SV-SMC from T2DM patients exhibited significantly larger spread cell areas (1.5-fold increase, P < 0.05), truncated F-actin fibers and reduced proliferation (33% reduction, P < 0.05). Furthermore, lower expression and activity of RhoA were observed in SV-SMC of T2DM patients (37% reduction in expression, P < 0.05 and 43% reduction in activity, P < 0.01). Conclusions: IMA-SMC appear impervious to phenotypic modulation by T2DM. In contrast, SV-SMC from T2DM patients exhibit phenotypic and functional changes accompanied by reduced RhoA activity. These aberrancies may be epigenetic in nature, compromising SMC plasticity and SV graft adaptation in T2DM patients. Summary: The internal mammary artery (IMA) is the conduit of choice for bypass grafting and is generally successful in all patients, including those with type 2 diabetes (T2DM). By contrast, saphenous vein (SV) is inferior to IMA and furthermore

Advancements in stem cells treatment of skeletal muscle wasting

Directory of Open Access Journals (Sweden)

mirella emeregalli

2014-02-01

Full Text Available Muscular dystrophies (MDs are a heterogeneous group of inherited disorders, in which progressive muscle wasting and weakness is often associated with exhaustion of muscle regeneration potential. Although physiological properties of skeletal muscle tissue are now well known, no treatments are effective for these diseases. Muscle regeneration was attempted by means transplantation of myogenic cells (from myoblast to embryonic stem cells and also by interfering with the malignant processes that originate in pathological tissues, such as uncontrolled fibrosis and inflammation. Taking into account the advances in the isolation of new subpopulation of stem cells and in the creation of artificial stem cell niches, we discuss how these emerging technologies offer great promises for therapeutic approaches to muscle diseases and muscle wasting associated with aging.

Isolation and individual electrical stimulation of single smooth-muscle cells from the urinary bladder of the pig

NARCIS (Netherlands)

J.J. Glerum (Jacobus); R. van Mastrigt (Ron); J.C. Romijn (Johannes); D.J. Griffiths (Derek)

1987-01-01

textabstractIn contrast to striated muscle, measurements on strips of smooth muscle cannot be uniquely interpreted in terms of an array of contractile units. Therefore scaling down to the single-cell level is necessary to gain detailed understanding of the contractile process in this type of muscle.

Regulatory T cells suppress muscle inflammation and injury in muscular dystrophy

Science.gov (United States)

Villalta, S. Armando; Rosenthal, Wendy; Martinez, Leonel; Kaur, Amanjot; Sparwasser, Tim; Tidball, James G.; Margeta, Marta; Spencer, Melissa J.; Bluestone, Jeffrey A.

2016-01-01

We examined the hypothesis that regulatory T cells (Tregs) modulate muscle injury and inflammation in the mdx mouse model of Duchenne muscular dystrophy (DMD). Although Tregs were largely absent in the muscle of wildtype mice and normal human muscle, they were present in necrotic lesions, displayed an activated phenotype and showed increased expression of interleukin (IL)-10 in dystrophic muscle from mdx mice. Depletion of Tregs exacerbated muscle injury and the severity of muscle inflammation, which was characterized by an enhanced interferon-gamma (IFNγ) response and activation of M1 macrophages. To test the therapeutic value of targeting Tregs in muscular dystrophy, we treated mdx mice with IL-2/anti-IL-2 complexes (IL-2c), and found that Tregs and IL-10 concentrations were increased in muscle, resulting in reduced expression of cyclooygenase-2 and decreased myofiber injury. These findings suggest that Tregs modulate the progression of muscular dystrophy by suppressing type 1 inflammation in muscle associated with muscle fiber injury, and highlight the potential of Treg-modulating agents as therapeutics for DMD. PMID:25320234

S1P receptor signalling and RGS proteins; expression and function in vascular smooth muscle cells and transfected CHO cells

NARCIS (Netherlands)

Hendriks-Balk, Mariëlle C.; van Loenen, Pieter B.; Hajji, Najat; Michel, Martin C.; Peters, Stephan L. M.; Alewijnse, Astrid E.

2009-01-01

Sphingosine-1-phosphate (S1P) signalling via G protein-coupled receptors is important for the regulation of cell function and differentiation. Specific Regulators of G protein Signalling (RGS) proteins modulate the function of these receptors in many cell types including vascular smooth muscle cells

Electrical stimulation as a biomimicry tool for regulating muscle cell behavior.

Science.gov (United States)

Ahadian, Samad; Ostrovidov, Serge; Hosseini, Vahid; Kaji, Hirokazu; Ramalingam, Murugan; Bae, Hojae; Khademhosseini, Ali

2013-01-01

There is a growing need to understand muscle cell behaviors and to engineer muscle tissues to replace defective tissues in the body. Despite a long history of the clinical use of electric fields for muscle tissues in vivo, electrical stimulation (ES) has recently gained significant attention as a powerful tool for regulating muscle cell behaviors in vitro. ES aims to mimic the electrical environment of electroactive muscle cells (e.g., cardiac or skeletal muscle cells) by helping to regulate cell-cell and cell-extracellular matrix (ECM) interactions. As a result, it can be used to enhance the alignment and differentiation of skeletal or cardiac muscle cells and to aid in engineering of functional muscle tissues. Additionally, ES can be used to control and monitor force generation and electrophysiological activity of muscle tissues for bio-actuation and drug-screening applications in a simple, high-throughput, and reproducible manner. In this review paper, we briefly describe the importance of ES in regulating muscle cell behaviors in vitro, as well as the major challenges and prospective potential associated with ES in the context of muscle tissue engineering.

Hydrogen improves glycemic control in type1 diabetic animal model by promoting glucose uptake into skeletal muscle.

Directory of Open Access Journals (Sweden)

Haruka Amitani

Full Text Available Hydrogen (H(2 acts as a therapeutic antioxidant. However, there are few reports on H(2 function in other capacities in diabetes mellitus (DM. Therefore, in this study, we investigated the role of H(2 in glucose transport by studying cultured mouse C2C12 cells and human hepatoma Hep-G2 cells in vitro, in addition to three types of diabetic mice [Streptozotocin (STZ-induced type 1 diabetic mice, high-fat diet-induced type 2 diabetic mice, and genetically diabetic db/db mice] in vivo. The results show that H(2 promoted 2-[(14C]-deoxy-d-glucose (2-DG uptake into C2C12 cells via the translocation of glucose transporter Glut4 through activation of phosphatidylinositol-3-OH kinase (PI3K, protein kinase C (PKC, and AMP-activated protein kinase (AMPK, although it did not stimulate the translocation of Glut2 in Hep G2 cells. H(2 significantly increased skeletal muscle membrane Glut4 expression and markedly improved glycemic control in STZ-induced type 1 diabetic mice after chronic intraperitoneal (i.p. and oral (p.o. administration. However, long-term p.o. administration of H(2 had least effect on the obese and non-insulin-dependent type 2 diabetes mouse models. Our study demonstrates that H(2 exerts metabolic effects similar to those of insulin and may be a novel therapeutic alternative to insulin in type 1 diabetes mellitus that can be administered orally.

Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

Energy Technology Data Exchange (ETDEWEB)

Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K., E-mail: mcloo001@tc.umn.edu

2011-04-01

The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin{sup -/-} (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a

Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

International Nuclear Information System (INIS)

Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.; Daniel, Mark L.; Cu, Sharon R.; McLoon, Linda K.

2011-01-01

The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry, EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin -/- (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a subpopulation of

α-smooth muscle actin is not a marker of fibrogenic cell activity in skeletal muscle fibrosis.

Directory of Open Access Journals (Sweden)

Wanming Zhao

Full Text Available α-Smooth muscle actin (α-SMA is used as a marker for a subset of activated fibrogenic cells, myofibroblasts, which are regarded as important effector cells of tissue fibrogenesis. We address whether α-SMA-expressing myofibroblasts are detectable in fibrotic muscles of mdx5cv mice, a mouse model for Duchenne muscular dystrophy (DMD, and whether the α-SMA expression correlates with the fibrogenic function of intramuscular fibrogenic cells. α-SMA immunostaining signal was not detected in collagen I (GFP-expressing cells in fibrotic muscles of ColI-GFP/mdx5cv mice, but it was readily detected in smooth muscle cells lining intramuscular blood vessel walls. α-SMA expression was detected by quantitative RT-PCR and Western blot in fibrogenic cells sorted from diaphragm and quadriceps muscles of the ColI-GFP/mdx5cv mice. Consistent with the more severe fibrosis in the ColI-GFP/mdx5cv diaphragm, the fibrogenic cells in the diaphragm exerted a stronger fibrogenic function than the fibrogenic cells in the quadriceps as gauged by their extracellular matrix gene expression. However, both gene and protein expression of α-SMA was lower in the diaphragm fibrogenic cells than in the quadriceps fibrogenic cells in the ColI-GFP/mdx5cv mice. We conclude that myofibroblasts are present in fibrotic skeletal muscles, but their expression of α-SMA is not detectable by immunostaining. The level of α-SMA expression by intramuscular fibrogenic cells does not correlate positively with the level of collagen gene expression or the severity of skeletal muscle fibrosis in the mdx5cv mice. α-SMA is not a functional marker of fibrogenic cells in skeletal muscle fibrosis associated with muscular dystrophy.

Direct evidence for a chronic CD8+-T-cell-mediated immune reaction to tax within the muscle of a human T-cell leukemia/lymphoma virus type 1-infected patient with sporadic inclusion body myositis.

Science.gov (United States)

Ozden, Simona; Cochet, Madeleine; Mikol, Jacqueline; Teixeira, Antonio; Gessain, Antoine; Pique, Claudine

2004-10-01

Human T-cell leukemia/lymphoma virus type 1 (HTLV-1) infection can lead to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), concomitantly with or without other inflammatory disorders such as myositis. These pathologies are considered immune-mediated diseases, and it is assumed that migration within tissues of both HTLV-1-infected CD4(+) T cells and anti-HTLV-1 cytotoxic T cells represents a pivotal event. However, although HTLV-1-infected T cells were found in inflamed lesions, the antigenic specificity of coinfiltrated CD8(+) T cells remains to be determined. In this study, we performed both ex vivo and in situ analyses using muscle biopsies obtained from an HTLV-1-infected patient with HAM/TSP and sporadic inclusion body myositis. We found that both HTLV-1-infected CD4(+) T cells and CD8(+) T cells directed to the dominant Tax antigen can be amplified from muscle cell cultures. Moreover, we were able to detect in two successive muscle biopsies both tax mRNA-positive mononuclear cells and T cells recognized by the Tax11-19/HLA-A*02 tetramer and positive for perforin. These findings provide the first direct demonstration that anti-Tax cytotoxic T cells are chronically recruited within inflamed tissues of an HTLV-1 infected patient, which validates the cytotoxic immune reaction model for the pathogenesis of HTLV-1-associated inflammatory disease.

Failure in activation of the canonical NF-κB pathway by human T-cell leukemia virus type 1 Tax in non-hematopoietic cell lines

Energy Technology Data Exchange (ETDEWEB)

Mizukoshi, Terumi; Komori, Hideyuki; Mizuguchi, Mariko [Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Abdelaziz, Hussein [Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Department of Medical Biochemistry, Faculty of Medicine, Mansoura University, Mansoura (Egypt); Hara, Toshifumi [Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Higuchi, Masaya [Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan); Tanaka, Yuetsu [Department of Immunology, Graduate School and Faculty of Medicine, Ryukyu University, Okinawa (Japan); Ohara, Yoshiro [Department of Microbiology, Kanazawa Medical University, Ishikawa (Japan); Funato, Noriko [Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan); Fujii, Masahiro [Division of Virology, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan); Nakamura, Masataka, E-mail: naka.gene@tmd.ac.jp [Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510 (Japan)

2013-09-01

Human T-cell leukemia virus type 1 (HTLV-1) Tax (Tax1) plays crucial roles in leukemogenesis in part through activation of NF-κB. In this study, we demonstrated that Tax1 activated an NF-κB binding (gpκB) site of the gp34/OX40 ligand gene in a cell type-dependent manner. Our examination showed that the gpκΒ site and authentic NF-κB (IgκB) site were activated by Tax1 in hematopoietic cell lines. Non-hematopoietic cell lines including hepatoma and fibroblast cell lines were not permissive to Tax1-mediated activation of the gpκB site, while the IgκB site was activated in those cells in association with binding of RelB. However RelA binding was not observed in the gpκB and IgκB sites. Our results suggest that HTLV-1 Tax1 fails to activate the canonical pathway of NF-κB in non-hematopoietic cell lines. Cell type-dependent activation of NF-κB by Tax1 could be associated with pathogenesis by HTLV-1 infection. - Highlights: • HTLV-1 Tax1 does not activate RelA of NF-κB in non-hematopoietic cell lines. • Tax1 activates the NF-κB non-canonical pathway in non-hematopoietic cell lines. • Tax1 does not induce RelA nuclear translocation in those cell lines, unlike TNFα. • The OX40L promoter κB site is activated by ectopic, but not endogenous, RelA.

Characterisation of L-Type Amino Acid Transporter 1 (LAT1 Expression in Human Skeletal Muscle by Immunofluorescent Microscopy

Directory of Open Access Journals (Sweden)

Nathan Hodson

2017-12-01

Full Text Available The branch chain amino acid leucine is a potent stimulator of protein synthesis in skeletal muscle. Leucine rapidly enters the cell via the L-Type Amino Acid Transporter 1 (LAT1; however, little is known regarding the localisation and distribution of this transporter in human skeletal muscle. Therefore, we applied immunofluorescence staining approaches to visualise LAT1 in wild type (WT and LAT1 muscle-specific knockout (mKO mice, in addition to basal human skeletal muscle samples. LAT1 positive staining was visually greater in WT muscles compared to mKO muscle. In human skeletal muscle, positive LAT1 staining was noted close to the sarcolemmal membrane (dystrophin positive staining, with a greater staining intensity for LAT1 observed in the sarcoplasmic regions of type II fibres (those not stained positively for myosin heavy-chain 1, Type II—25.07 ± 5.93, Type I—13.71 ± 1.98, p < 0.01, suggesting a greater abundance of this protein in these fibres. Finally, we observed association with LAT1 and endothelial nitric oxide synthase (eNOS, suggesting LAT1 association close to the microvasculature. This is the first study to visualise the distribution and localisation of LAT1 in human skeletal muscle. As such, this approach provides a validated experimental platform to study the role and regulation of LAT1 in human skeletal muscle in response to various physiological and pathophysiological models.

The cell nuclei of skeletal muscle cells are transcriptionally active in hibernating edible dormice

Directory of Open Access Journals (Sweden)

Muller Sylviane

2009-03-01

Full Text Available Abstract Background Skeletal muscle is able to react in a rapid, dynamic way to metabolic and mechanical stimuli. In particular, exposure to either prolonged starvation or disuse results in muscle atrophy. At variance, in hibernating animals muscle atrophy may be scarce or absent after bouts of hibernation i.e., periods of prolonged (months inactivity and food deprivation, and muscle function is fully preserved at arousal. In this study, myocytes from the quadriceps muscle of euthermic and hibernating edible dormice were investigated by a combination of morphological, morphometrical and immunocytochemical analyses at the light and electron microscopy level. The focus was on cell nuclei and mitochondria, which are highly sensitive markers of changing metabolic rate. Results Findings presented herein demonstrate that: 1 the general histology of the muscle, inclusive of muscle fibre shape and size, and the ratio of fast and slow fibre types are not affected by hibernation; 2 the fine structure of cytoplasmic and nuclear constituents is similar in euthermia and hibernation but for lipid droplets, which accumulate during lethargy; 3 during hibernation, mitochondria are larger in size with longer cristae, and 4 myonuclei maintain the same amount and distribution of transcripts and transcription factors as in euthermia. Conclusion In this study we demonstrate that skeletal muscle cells of the hibernating edible dormouse maintain their structural and functional integrity in full, even after months in the nest. A twofold explanation for that is envisaged: 1 the maintenance, during hibernation, of low-rate nuclear and mitochondrial activity counterbalancing myofibre wasting, 2 the intensive muscle stimulation (shivering during periodic arousals in the nest, which would mimic physical exercise. These two factors would prevent muscle atrophy usually occurring in mammals after prolonged starvation and/or inactivity as a consequence of prevailing catabolism

Formation of Nano scale Bio imprints of Muscle Cells Using UV-Cured Spin-Coated Polymers

International Nuclear Information System (INIS)

Samsuri, F.; Alkaisi, M.M.; Mitchell, J.S.; Evans, J.J.

2009-01-01

We report a nano scale replication method suitable for biological specimens that has potential in single cell studies and in formation of 3D biocompatible scaffolds. Earlier studies using a heat-curable polydimethylsiloxane (PDMS) or a UV-curable elastomer introduced Bio imprint replication to facilitate cell imaging. However, the replicating conditions for thermal polymerization are known to cause cell dehydration during curing. In this study, a UV-cured methacrylate copolymer was developed for use in creating replicas of living cells and was tested on rat muscle cells. Bio imprints of muscle cells were formed by spin coating under UV irradiation. The polymer replicas were then separated from the muscle cells and were analyzed under an Atomic Force Microscope (AFM), in tapping mode, because it has low tip-sample forces and thus will not destroy the fine structures of the imprint. The new polymer is biocompatible with higher replication resolution and has a faster curing process than other types of silicon-based organic polymers such as PDMS. High resolution images of the muscle cell imprints showed the micro-and nano structures of the muscle cells, including cellular fibers and structures within the cell membranes. The AFM is able to image features at nano scale resolution with the potential for recognizing abnormalities on cell membranes at early stages of disease progression.

Human muscle fiber type-specific insulin signaling: Impact of obesity and type 2 diabetes

DEFF Research Database (Denmark)

Albers, Peter Hjorth; Pedersen, Andreas J T; Birk, Jesper Bratz

2015-01-01

Skeletal muscle is a heterogeneous tissue composed of different fiber types. Studies suggest that insulin-mediated glucose metabolism is different between muscle fiber types. We hypothesized that differences are due to fiber-type specific expression/regulation of insulin signaling elements and....../or metabolic enzymes. Pools of type I and II fibers were prepared from biopsies of the vastus lateralis muscles from lean, obese and type 2 diabetic subjects before and after a hyperinsulinemic-euglycemic clamp. Type I fibers compared to type II fibers have higher protein levels of the insulin receptor, GLUT4......, hexokinase II, glycogen synthase (GS), pyruvate dehydrogenase (PDH-E1α) and a lower protein content of Akt2, TBC1D4 and TBC1D1. In type I fibers compared to type II fibers, the phosphorylation-response to insulin was similar (TBC1D4, TBC1D1 and GS) or decreased (Akt and PDH-E1α). Phosphorylation...

Functional vascular smooth muscle cells derived from human induced pluripotent stem cells via mesenchymal stem cell intermediates

Science.gov (United States)

Bajpai, Vivek K.; Mistriotis, Panagiotis; Loh, Yuin-Han; Daley, George Q.; Andreadis, Stelios T.

2012-01-01

Aims Smooth muscle cells (SMC) play an important role in vascular homeostasis and disease. Although adult mesenchymal stem cells (MSC) have been used as a source of contractile SMC, they suffer from limited proliferation potential and culture senescence, particularly when originating from older donors. By comparison, human induced pluripotent stem cells (hiPSC) can provide an unlimited source of functional SMC for autologous cell-based therapies and for creating models of vascular disease. Our goal was to develop an efficient strategy to derive functional, contractile SMC from hiPSC. Methods and results We developed a robust, stage-wise, feeder-free strategy for hiPSC differentiation into functional SMC through an intermediate stage of multipotent MSC, which could be coaxed to differentiate into fat, bone, cartilage, and muscle. At this stage, the cells were highly proliferative and displayed higher clonogenic potential and reduced senescence when compared with parental hair follicle mesenchymal stem cells. In addition, when exposed to differentiation medium, the myogenic proteins such as α-smooth muscle actin, calponin, and myosin heavy chain were significantly upregulated and displayed robust fibrillar organization, suggesting the development of a contractile phenotype. Indeed, tissue constructs prepared from these cells exhibited high levels of contractility in response to receptor- and non-receptor-mediated agonists. Conclusion We developed an efficient stage-wise strategy that enabled hiPSC differentiation into contractile SMC through an intermediate population of clonogenic and multipotent MSC. The high yield of MSC and SMC derivation suggests that our strategy may facilitate an acquisition of the large numbers of cells required for regenerative medicine or for studying vascular disease pathophysiology. PMID:22941255

Stem Cell Antigen-1 in Skeletal Muscle Function

OpenAIRE

Bernstein, Harold S.; Samad, Tahmina; Cholsiripunlert, Sompob; Khalifian, Saami; Gong, Wenhui; Ritner, Carissa; Aurigui, Julian; Ling, Vivian; Wilschut, Karlijn J.; Bennett, Stephen; Hoffman, Julien; Oishi, Peter

2013-01-01

Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1...

SIRT1 deacetylates RFX5 and antagonizes repression of collagen type I (COL1A2) transcription in smooth muscle cells

Energy Technology Data Exchange (ETDEWEB)

Xia, Jun [Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University (China); Department of Respiratory Medicine, Jiangsu Provincial Hospital of Chinese Traditional Medicine (China); Wu, Xiaoyan; Yang, Yuyu; Zhao, Yuhao [Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University (China); Fang, Mingming [Jiangsu Jiankang Vocational Institute (China); Xie, Weiping, E-mail: wpxienjmu@gmail.com [Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University (China); Wang, Hong, E-mail: hwangnjmu@gmail.com [Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University (China); Xu, Yong [Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University (China)

2012-11-16

Highlights: Black-Right-Pointing-Pointer SIRT1 interacts with and deacetylates RFX5. Black-Right-Pointing-Pointer SIRT1 activation attenuates whereas SIRT1 inhibition enhances collagen repression by RFX5 in vascular smooth muscle cells. Black-Right-Pointing-Pointer SIRT1 promotes cytoplasmic localization and proteasomal degradation of RFX5 and cripples promoter recruitment of RFX5. Black-Right-Pointing-Pointer IFN-{gamma} represses SIRT1 expression in vascular smooth muscle cells. Black-Right-Pointing-Pointer SIRT1 agonist alleviates collagen repression by IFN-{gamma} in vascular smooth muscle cells. -- Abstract: Decreased expression of collagen by vascular smooth muscle cells (SMCs) within the atherosclerotic plaque contributes to the thinning of the fibrous cap and poses a great threat to plaque rupture. Elucidation of the mechanism underlying repressed collagen type I (COL1A2) gene would potentially provide novel solutions that can prevent rupture-induced complications. We have previously shown that regulatory factor for X-box (RFX5) binds to the COL1A2 transcription start site and represses its transcription. Here we report that SIRT1, an NAD-dependent, class III deacetylase, forms a complex with RFX5. Over-expression of SIRT1 or NAMPT, which synthesizes NAD+ to activate SIRT1, or treatment with the SIRT1 agonist resveratrol decreases RFX5 acetylation and disrupts repression of the COL1A2 promoter activity by RFX5. On the contrary, knockdown of SIRT1 or treatment with SIRT1 inhibitors induces RFX5 acetylation and enhances the repression of collagen transcription. SIRT1 antagonizes RFX5 activity by promoting its nuclear expulsion and proteasomal degradation hence dampening its binding to the COL1A2 promoter. The pro-inflammatory cytokine IFN-{gamma} represses COL1A2 transcription by down-regulating SIRT1 expression in SMCs. Therefore, our data have identified as novel pathway whereby SIRT1 maintains collagen synthesis in SMCs by modulating RFX5 activity.

ATP-sensitive K(+-channels in muscle cells: features and physiological role

Directory of Open Access Journals (Sweden)

O. B. Vadzyuk

2014-08-01

Full Text Available ATP-sensitive K+-channels of plasma membranes belong to the inward rectifier potassium channels type. They are involved in coupling of electrical activity of muscle cell with its metabolic­ state. These channels are heterooctameric and consist of two types of subunits: four poreforming (Kir 6.х and four regulatory (SUR, sulfonylurea receptor. The Kir subunits contain highly selective K+ filter and provide for high-velocity K+ currents. The SUR subunits contain binding sites for activators and blockers and have metabolic sensor, which enables channel activation under conditions of metabolic stress. ATP blocks K+ currents through the ATP-sensitive K+-channels in the most types of muscle cells. However, functional activity of these channels does not depend on absolute concentration of ATP but on the АТР/ADP ratio and presence of Mg2+. Physiologically active substances, such as phosphatidylinositol bisphosphate and fatty acid esters can regulate the activity of these structures in muscle cells. Activation of these channels under ischemic conditions underlies their cytoprotective action, which results in prevention of Ca2+ overload in cytosol. In contrast to ATP-sensitive K+-channels of plasma membranes, the data regarding the structure and function of ATP-sensitive K+-channels of mitochondrial membrane are contradictory. Pore-forming subunits of this channel have not been firmly identified yet. ATP-sensitive K+ transport through the mitochondrial­ membrane is easily tested by different methods, which are briefly reviewed in this paper. Interaction of mitoKATP with physiological and pharmacological ligands is discussed as well.

Plasma and Muscle Myostatin in Relation to Type 2 Diabetes

Science.gov (United States)

Brandt, Claus; Nielsen, Anders R.; Fischer, Christian P.; Hansen, Jakob; Pedersen, Bente K.; Plomgaard, Peter

2012-01-01

Objective Myostatin is a secreted growth factor expressed in skeletal muscle tissue, which negatively regulates skeletal muscle mass. Recent animal studies suggest a role for myostatin in insulin resistance. We evaluated the possible metabolic role of myostatin in patients with type 2 diabetes and healthy controls. Design 76 patients with type 2 diabetes and 92 control subjects were included in the study. They were matched for age, gender and BMI. Plasma samples and biopsies from the vastus lateralis muscle were obtained to assess plasma myostatin and expression of myostatin in skeletal muscle. Results Patients with type 2 diabetes had higher fasting glucose (8.9 versus 5.1 mmol/L, Pmyostatin mRNA content than the control subjects. Plasma myostatin concentrations did not differ between patients with type 2 diabetes and controls. In healthy controls, muscle myostatin mRNA correlated with HOMA2-IR (r = 0.30, Pmyostatin may have a negative effect on metabolism. However, the metabolic effect of myostatin appears to be overruled by other factors in patients with type 2 diabetes. PMID:22615949

Relationships between Cargo, Cell Penetrating Peptides and Cell Type for Uptake of Non-Covalent Complexes into Live Cells

Directory of Open Access Journals (Sweden)

Andrea-Anneliese Keller

2013-02-01

Full Text Available Modulating signaling pathways for research and therapy requires either suppression or expression of selected genes or internalization of proteins such as enzymes, antibodies, nucleotide binding proteins or substrates including nucleoside phosphates and enzyme inhibitors. Peptides, proteins and nucleotides are transported by fusing or conjugating them to cell penetrating peptides or by formation of non-covalent complexes. The latter is often preferred because of easy handling, uptake efficiency and auto-release of cargo into the live cell. In our studies complexes are formed with labeled or readily detectable cargoes for qualitative and quantitative estimation of their internalization. Properties and behavior of adhesion and suspension vertebrate cells as well as the protozoa Leishmania tarentolae are investigated with respect to proteolytic activity, uptake efficiency, intracellular localization and cytotoxicity. Our results show that peptide stability to membrane-bound, secreted or intracellular proteases varies between different CPPs and that the suitability of individual CPPs for a particular cargo in complex formation by non-covalent interactions requires detailed studies. Cells vary in their sensitivity to increasing concentrations of CPPs. Thus, most cells can be efficiently transduced with peptides, proteins and nucleotides with intracellular concentrations in the low micromole range. For each cargo, cell type and CPP the optimal conditions must be determined separately.

Injectable biomimetic liquid crystalline scaffolds enhance muscle stem cell transplantation

Science.gov (United States)

Sleep, Eduard; McClendon, Mark T.; Preslar, Adam T.; Chen, Charlotte H.; Sangji, M. Hussain; Pérez, Charles M. Rubert; Haynes, Russell D.; Meade, Thomas J.; Blau, Helen M.; Stupp, Samuel I.

2017-01-01

Muscle stem cells are a potent cell population dedicated to efficacious skeletal muscle regeneration, but their therapeutic utility is currently limited by mode of delivery. We developed a cell delivery strategy based on a supramolecular liquid crystal formed by peptide amphiphiles (PAs) that encapsulates cells and growth factors within a muscle-like unidirectionally ordered environment of nanofibers. The stiffness of the PA scaffolds, dependent on amino acid sequence, was found to determine the macroscopic degree of cell alignment templated by the nanofibers in vitro. Furthermore, these PA scaffolds support myogenic progenitor cell survival and proliferation and they can be optimized to induce cell differentiation and maturation. We engineered an in vivo delivery system to assemble scaffolds by injection of a PA solution that enabled coalignment of scaffold nanofibers with endogenous myofibers. These scaffolds locally retained growth factors, displayed degradation rates matching the time course of muscle tissue regeneration, and markedly enhanced the engraftment of muscle stem cells in injured and noninjured muscles in mice. PMID:28874575

Adding muscle where you need it: non-uniform hypertrophy patterns in elite sprinters.

Science.gov (United States)

Handsfield, G G; Knaus, K R; Fiorentino, N M; Meyer, C H; Hart, J M; Blemker, S S

2017-10-01

Sprint runners achieve much higher gait velocities and accelerations than average humans, due in part to large forces generated by their lower limb muscles. Various factors have been explored in the past to understand sprint biomechanics, but the distribution of muscle volumes in the lower limb has not been investigated in elite sprinters. In this study, we used non-Cartesian MRI to determine muscle sizes in vivo in a group of 15 NCAA Division I sprinters. Normalizing muscle sizes by body size, we compared sprinter muscles to non-sprinter muscles, calculated Z-scores to determine non-uniformly large muscles in sprinters, assessed bilateral symmetry, and assessed gender differences in sprinters' muscles. While limb musculature per height-mass was 22% greater in sprinters than in non-sprinters, individual muscles were not all uniformly larger. Hip- and knee-crossing muscles were significantly larger among sprinters (mean difference: 30%, range: 19-54%) but only one ankle-crossing muscle was significantly larger (tibialis posterior, 28%). Population-wide asymmetry was not significant in the sprint population but individual muscle asymmetries exceeded 15%. Gender differences in normalized muscle sizes were not significant. The results of this study suggest that non-uniform hypertrophy patterns, particularly large hip and knee flexors and extensors, are advantageous for fast sprinting. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Nuclear fusion-independent smooth muscle differentiation of human adipose-derived stem cells induced by a smooth muscle environment.

Science.gov (United States)

Zhang, Rong; Jack, Gregory S; Rao, Nagesh; Zuk, Patricia; Ignarro, Louis J; Wu, Benjamin; Rodríguez, Larissa V

2012-03-01

Human adipose-derived stem cells hASC have been isolated and were shown to have multilineage differentiation capacity. Although both plasticity and cell fusion have been suggested as mechanisms for cell differentiation in vivo, the effect of the local in vivo environment on the differentiation of adipose-derived stem cells has not been evaluated. We previously reported the in vitro capacity of smooth muscle differentiation of these cells. In this study, we evaluate the effect of an in vivo smooth muscle environment in the differentiation of hASC. We studied this by two experimental designs: (a) in vivo evaluation of smooth muscle differentiation of hASC injected into a smooth muscle environment and (b) in vitro evaluation of smooth muscle differentiation capacity of hASC exposed to bladder smooth muscle cells. Our results indicate a time-dependent differentiation of hASC into mature smooth muscle cells when these cells are injected into the smooth musculature of the urinary bladder. Similar findings were seen when the cells were cocultured in vitro with primary bladder smooth muscle cells. Chromosomal analysis demonstrated that microenvironment cues rather than nuclear fusion are responsible for this differentiation. We conclude that cell plasticity is present in hASCs, and their differentiation is accomplished in the absence of nuclear fusion. Copyright © 2011 AlphaMed Press.

Single Nisoldipine-Sensitive Calcium Channels in Smooth Muscle Cells Isolated from Rabbit Mesenteric Artery

Science.gov (United States)

Worley, Jennings F.; Deitmer, Joachim W.; Nelson, Mark T.

1986-08-01

Single smooth muscle cells were enzymatically isolated from the rabbit mesenteric artery. At physiological levels of external Ca, these cells were relaxed and contracted on exposure to norepinephrine, caffeine, or high levels of potassium. The patch-clamp technique was used to measure unitary currents through single channels in the isolated cells. Single channels were selective for divalent cations and exhibited two conductance levels, 8 pS and 15 pS. Both types of channels were voltage-dependent, and channel activity occurred at potentials positive to -40 mV. The activity of both channel types was almost completely inhibited by 50 nM nisoldipine. These channels appear to be the pathways for voltage-dependent Ca influx in vascular smooth muscle and may be the targets of the clinically used dihydropyridines.

Muscle fiber type specific induction of slow myosin heavy chain 2 gene expression by electrical stimulation

International Nuclear Information System (INIS)

Crew, Jennifer R.; Falzari, Kanakeshwari; DiMario, Joseph X.

2010-01-01

Vertebrate skeletal muscle fiber types are defined by a broad array of differentially expressed contractile and metabolic protein genes. The mechanisms that establish and maintain these different fiber types vary throughout development and with changing functional demand. Chicken skeletal muscle fibers can be generally categorized as fast and fast/slow based on expression of the slow myosin heavy chain 2 (MyHC2) gene in fast/slow muscle fibers. To investigate the cellular and molecular mechanisms that control fiber type formation in secondary or fetal muscle fibers, myoblasts from the fast pectoralis major (PM) and fast/slow medial adductor (MA) muscles were isolated, allowed to differentiate in vitro, and electrically stimulated. MA muscle fibers were induced to express the slow MyHC2 gene by electrical stimulation, whereas PM muscle fibers did not express the slow MyHC2 gene under identical stimulation conditions. However, PM muscle fibers did express the slow MyHC2 gene when electrical stimulation was combined with inhibition of inositol triphosphate receptor (IP3R) activity. Electrical stimulation was sufficient to increase nuclear localization of expressed nuclear-factor-of-activated-T-cells (NFAT), NFAT-mediated transcription, and slow MyHC2 promoter activity in MA muscle fibers. In contrast, both electrical stimulation and inhibitors of IP3R activity were required for these effects in PM muscle fibers. Electrical stimulation also increased levels of peroxisome-proliferator-activated receptor-γ co-activator-1 (PGC-1α) protein in PM and MA muscle fibers. These results indicate that MA muscle fibers can be induced by electrical stimulation to express the slow MyHC2 gene and that fast PM muscle fibers are refractory to stimulation-induced slow MyHC2 gene expression due to fast PM muscle fiber specific cellular mechanisms involving IP3R activity.

New Insights into Muscle Fibre Types in Casertana Pig

Directory of Open Access Journals (Sweden)

Salvatore Velotto

2010-01-01

Full Text Available Little is known about the Casertana pig. The aim of this study was to evaluate the effect of sex on histochemical and morphometrical characteristics of muscle fibres (myocytes in this pure breed and to verify the presence of giant fibres as well as vascularity of the muscle. Finally, maximum shortening velocity and isometric tension were measured in single muscle fibres. Sixteen Casertana pigs (8 males, 8 females from a farm in Campania (Italy were slaughtered at one year of age. Muscle tissues were obtained from psoas minor, rhomboideus and longissimus dorsi. Myofibres were stained for myosin adenosine triphosphatase, succinic dehydrogenase, and α-amylase-periodic acid schiff. For all fibre types, the area and perimeter were measured. Slowtwitch oxidative fibres, fast-twitch glycolytic fibres and fast-twitch oxidative-glycolytic fibres were histochemically differentiated; an image-analyzing system was used. The results showed significant differences between the sexes in the size of all three fibre types. The psoas minor muscle had a high percentage of slow-twitch oxidative fibres and contained more capillaries per fibre and per mm2 than rhomboideus and longissimus dorsi, in which fast-twitch glycolytic fibres dominated. The cross-sectional area of all fibre types was larger in longissimus dorsi than in rhomboideus and psoas minor muscles; the giant fibres were present in the longissimus dorsi muscle only. Besides, isometric tension values were higher in fast-twitch glycolytic fibres than in the other ones. Variations in fibre type composition may contribute to meat quality.

Dissemination of Walker 256 carcinoma cells to rat skeletal muscle

International Nuclear Information System (INIS)

Ueoka, H.; Hayashi, K.; Namba, T.; Grob, D.

1986-01-01

After injection of 10 6 Walker 256 carcinoma cells labelled with 125 I-5-iodo-2'-deoxyuridine into the tail vein, peak concentration in skeletal muscle was 46 cells/g at 60 minutes, which was lower than 169202, 1665, 555, 198 and 133 cells/g, respectively, at 30 or 60 minutes in lung, liver, spleen, kidney and heart. Because skeletal muscle constitutes 37.4% of body weight, the total number of tumor cells was 2323 cells, which was much greater than in spleen, kidney and heart with 238, 271, and 85 cells, respectively, and only less than in lung and liver, at 222857 and 11700 cells, respectively. The total number in skeletal muscle became greater than in liver at 4 hours and than in lung at 24 hours. Ten minutes after injection of 7.5 x 10 6 Walker 256 carcinoma cells into the abdominal aorta of rats, a mean of 31 colony-forming cells were recovered from the gastrocnemius, while 106 cells were recovered from the lung after injection into the tail vein. These results indicate that a large number of viable tumor cells can be arrested in skeletal muscle through circulation. The rare remote metastasis of malignancies into skeletal muscle despite constantly circulating tumor cells does not appear to be due to poor dissemination of tumor cells into muscle but due to unhospitable environment of skeletal muscle

Robust generation and expansion of skeletal muscle progenitors and myocytes from human pluripotent stem cells.

Science.gov (United States)

Shelton, Michael; Kocharyan, Avetik; Liu, Jun; Skerjanc, Ilona S; Stanford, William L

2016-05-15

Human pluripotent stem cells provide a developmental model to study early embryonic and tissue development, tease apart human disease processes, perform drug screens to identify potential molecular effectors of in situ regeneration, and provide a source for cell and tissue based transplantation. Highly efficient differentiation protocols have been established for many cell types and tissues; however, until very recently robust differentiation into skeletal muscle cells had not been possible unless driven by transgenic expression of master regulators of myogenesis. Nevertheless, several breakthrough protocols have been published in the past two years that efficiently generate cells of the skeletal muscle lineage from pluripotent stem cells. Here, we present an updated version of our recently described 50-day protocol in detail, whereby chemically defined media are used to drive and support muscle lineage development from initial CHIR99021-induced mesoderm through to PAX7-expressing skeletal muscle progenitors and mature skeletal myocytes. Furthermore, we report an optional method to passage and expand differentiating skeletal muscle progenitors approximately 3-fold every 2weeks using Collagenase IV and continued FGF2 supplementation. Both protocols have been optimized using a variety of human pluripotent stem cell lines including patient-derived induced pluripotent stem cells. Taken together, our differentiation and expansion protocols provide sufficient quantities of skeletal muscle progenitors and myocytes that could be used for a variety of studies. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Muscle fibre types of fishes : structural and functional specialization

NARCIS (Netherlands)

Akster, H.A.

1984-01-01

Muscles of fishes are active in a variety of movements that differ in velocity, duration and excursion length. To investigate how muscles meet the, often conflicting, demands imposed upon them by these movements, the fibre type composition of several muscles was determined. The ultrastructural and

A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury

DEFF Research Database (Denmark)

Husted, Rasmus S; Bencke, Jesper; Andersen, Lars Louis

2016-01-01

phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. METHODS: Sixty-two adolescent female elite......BACKGROUND: Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular...... football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored...

The influence of capillarization on satellite cell pool expansion and activation following exercise-induced muscle damage in healthy young men.

Science.gov (United States)

Nederveen, Joshua P; Joanisse, Sophie; Snijders, Tim; Thomas, Aaron C Q; Kumbhare, Dinesh; Parise, Gianni

2018-03-15

Skeletal muscle stem cells (satellite cells) play a crucial role in repair and remodelling of muscle in response to exercise. Satellite cells are in close spatial proximity to muscle capillaries and therefore may be influenced by them. In this study, we describe the activation and expansion of the satellite cell pool in response to eccentric contraction-induced muscle damage in individuals with significantly different levels of muscle capillarization. Individuals with greater capillarization and capacity for muscle perfusion demonstrated enhanced activation and/or expansion of the satellite cell pool allowing for an accelerated recovery of muscle function. These results provide insight into the critical relationship between muscle capillarization and satellite cells during skeletal muscle repair. Factors that determine the skeletal muscle satellite cell (SC) response remain incompletely understood. It is known, however, that SC activation status is closely related to the anatomical relationship between SCs and muscle capillaries. We investigated the impact of muscle fibre capillarization on the expansion and activation status of SCs following a muscle-damaging exercise protocol in healthy young men. Twenty-nine young men (21 ± 0.5 years) performed 300 unilateral eccentric contractions (180 deg s -1 ) of the knee extensors. Percutaneous muscle biopsies from the vastus lateralis and blood samples from the antecubital vein were taken prior to (Pre) exercise and at 6, 24, 72 and 96 h of post-exercise recovery. A comparison was made between subjects who had a relative low mixed muscle capillary-to-fibre perimeter exchange index (CFPE; Low group) and high mixed muscle CFPE index (High group) at baseline. Type I and type II muscle fibre size, myonuclear content, capillarization, and SC response were determined via immunohistochemistry. Overall, there was a significant correlation (r = 0.39; P < 0.05) between the expansion of SC content (change in total Pax7

Generation of skeletal muscle from transplanted embryonic stem cells in dystrophic mice

International Nuclear Information System (INIS)

Bhagavati, Satyakam; Xu Weimin

2005-01-01

Embryonic stem (ES) cells have great therapeutic potential because of their capacity to proliferate extensively and to form any fully differentiated cell of the body, including skeletal muscle cells. Successful generation of skeletal muscle in vivo, however, requires selective induction of the skeletal muscle lineage in cultures of ES cells and following transplantation, integration of appropriately differentiated skeletal muscle cells with recipient muscle. Duchenne muscular dystrophy (DMD), a severe progressive muscle wasting disease due to a mutation in the dystrophin gene and the mdx mouse, an animal model for DMD, are characterized by the absence of the muscle membrane associated protein, dystrophin. Here, we show that co-culturing mouse ES cells with a preparation from mouse muscle enriched for myogenic stem and precursor cells, followed by injection into mdx mice, results occasionally in the formation of normal, vascularized skeletal muscle derived from the transplanted ES cells. Study of this phenomenon should provide valuable insights into skeletal muscle development in vivo from transplanted ES cells

BMP signaling regulates satellite cell-dependent postnatal muscle growth.

Science.gov (United States)

Stantzou, Amalia; Schirwis, Elija; Swist, Sandra; Alonso-Martin, Sonia; Polydorou, Ioanna; Zarrouki, Faouzi; Mouisel, Etienne; Beley, Cyriaque; Julien, Anaïs; Le Grand, Fabien; Garcia, Luis; Colnot, Céline; Birchmeier, Carmen; Braun, Thomas; Schuelke, Markus; Relaix, Frédéric; Amthor, Helge

2017-08-01

Postnatal growth of skeletal muscle largely depends on the expansion and differentiation of resident stem cells, the so-called satellite cells. Here, we demonstrate that postnatal satellite cells express components of the bone morphogenetic protein (BMP) signaling machinery. Overexpression of noggin in postnatal mice (to antagonize BMP ligands), satellite cell-specific knockout of Alk3 (the gene encoding the BMP transmembrane receptor) or overexpression of inhibitory SMAD6 decreased satellite cell proliferation and accretion during myofiber growth, and ultimately retarded muscle growth. Moreover, reduced BMP signaling diminished the adult satellite cell pool. Abrogation of BMP signaling in satellite cell-derived primary myoblasts strongly diminished cell proliferation and upregulated the expression of cell cycle inhibitors p21 and p57 In conclusion, these results show that BMP signaling defines postnatal muscle development by regulating satellite cell-dependent myofiber growth and the generation of the adult muscle stem cell pool. © 2017. Published by The Company of Biologists Ltd.

Protein Turnover and Cellular Stress in Mildly and Severely Affected Muscles from Patients with Limb Girdle Muscular Dystrophy Type 2I

DEFF Research Database (Denmark)

Hauerslev, Simon; Sveen, Marie-Louise; Vissing, John

2013-01-01

Patients with Limb girdle muscular dystrophy type 2I (LGMD2I) are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal...... by using the developmental markers embryonic myosin heavy chain (eMHC) and neural cell adhesion molecule (NCAM) and also assessing satellite cell activation status by myogenin positivity. Severe muscle histopathology was occasionally observed in the proximal muscles of patients with LGMD2I whereas distal...... highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy....

mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration

Energy Technology Data Exchange (ETDEWEB)

Zhang, Pengpeng [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Liang, Xinrong; Shan, Tizhong [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Jiang, Qinyang [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); College of Animal Science and Technology, Guangxi University, Nanning 530004 (China); Deng, Changyan [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Zheng, Rong, E-mail: zhengrong@mail.hzau.edu.cn [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Kuang, Shihuan, E-mail: skuang@purdue.edu [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States)

2015-07-17

The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7{sup CreER} and Mtor{sup flox/flox} mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes. - Highlights: • Pax7{sup CreER} was used to delete Mtor gene in satellite cells. • Satellite cell specific deletion of Mtor impairs muscle regeneration. • mTOR is necessary for satellite cell proliferation and differentiation. • Deletion of Mtor leads to reduced expression of key myogenic genes.

mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration

International Nuclear Information System (INIS)

Zhang, Pengpeng; Liang, Xinrong; Shan, Tizhong; Jiang, Qinyang; Deng, Changyan; Zheng, Rong; Kuang, Shihuan

2015-01-01

The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7 CreER and Mtor flox/flox mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes. - Highlights: • Pax7 CreER was used to delete Mtor gene in satellite cells. • Satellite cell specific deletion of Mtor impairs muscle regeneration. • mTOR is necessary for satellite cell proliferation and differentiation. • Deletion of Mtor leads to reduced expression of key myogenic genes

Muscle phenotype in patients with myotonic dystrophy type 1

DEFF Research Database (Denmark)

Andersen, Anne Grete Kielgast; Orngreen, Mette C; Preisler, Nicolai Rasmus

2012-01-01

Introduction: The pathogenesis of muscle involvement in patients with myotonic dystrophy type 1 (DM1) is not well understood. In this study, we characterized the muscle phenotype in patients with confirmed DM1. Methods: In 38 patients, muscle strength was tested by hand-held dynamometry. Myotonia...... was evaluated by a handgrip test and by analyzing the decrement of the compound muscle action potential. Muscle biopsies were assessed for morphological changes and Na(+) -K(+) pump content. Results: Muscle strength correlated with a decline in Na(+) -K(+) pump content (r = 0.60, P

Muscle Stem Cell Fate Is Controlled by the Cell-Polarity Protein Scrib

Directory of Open Access Journals (Sweden)

Yusuke Ono

2015-02-01

Full Text Available Satellite cells are resident skeletal muscle stem cells that supply myonuclei for homeostasis, hypertrophy, and repair in adult muscle. Scrib is one of the major cell-polarity proteins, acting as a potent tumor suppressor in epithelial cells. Here, we show that Scrib also controls satellite-cell-fate decisions in adult mice. Scrib is undetectable in quiescent cells but becomes expressed during activation. Scrib is asymmetrically distributed in dividing daughter cells, with robust accumulation in cells committed to myogenic differentiation. Low Scrib expression is associated with the proliferative state and preventing self-renewal, whereas high Scrib levels reduce satellite cell proliferation. Satellite-cell-specific knockout of Scrib in mice causes a drastic and insurmountable defect in muscle regeneration. Thus, Scrib is a regulator of tissue stem cells, controlling population expansion and self-renewal with Scrib expression dynamics directing satellite cell fate.

Stimulation of aortic smooth muscle cell mitogenesis by serotonin

International Nuclear Information System (INIS)

Nemecek, G.M.; Coughlin, S.R.; Handley, D.A.; Moskowitz, M.A.

1986-01-01

Bovine aortic smooth muscle cells in vitro responded to 1 nM to 10 μM serotonin with increased incorporation of [ 3 H]thymidine into DNA. The mitogenic effect of serotonin was half-maximal at 80 nM and maximal above 1 μM. At a concentration of 1 μM, serotonin stimulated smooth muscle cell mitogenesis to the same extent as human platelet-derived growth factor (PDGF) at 12 ng/ml. Tryptamine was ≅ 1/10th as potent as serotonin as a mitogen for smooth muscle cells. Other indoles that are structurally related to serotonin (D- and L-tryptophan, 5-hydroxy-L-tryptophan, N-acetyl-5-hydroxytryptamine, melatonin, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophol) and quipazine were inactive. The stimulatory effect of serotonin on smooth muscle cell DNA synthesis required prolonged (20-24 hr) exposure to the agonist and was attenuated in the presence of serotonin D receptor antagonists. When smooth muscle cells were incubated with submaximal concentrations of serotonin and PDGF, synergistic rather than additive mitogenic responses were observed. These data indicate that serotonin has a significant mitogenic effect on smooth muscle cells in vitro, which appears to be mediated by specific plasma membrane receptors

Intramuscular fatty acid metabolism in contracting and non-contracting human skeletal muscle

DEFF Research Database (Denmark)

Sacchetti, M; Saltin, B; Osada, T

2002-01-01

The present study was undertaken to investigate the fate of blood-borne non-esterified fatty acids (NEFA) entering contracting and non-contracting knee extensor muscles of healthy young individuals. [U-(13)C]-palmitate was infused into a forearm vein during 5 h of one-legged knee extensor exercis...... and degraded and that the metabolic fate of plasma NEFA entering the muscle is influenced by muscle contraction, so that a higher proportion is directed towards oxidation at the expense of storage in mTAG.......The present study was undertaken to investigate the fate of blood-borne non-esterified fatty acids (NEFA) entering contracting and non-contracting knee extensor muscles of healthy young individuals. [U-(13)C]-palmitate was infused into a forearm vein during 5 h of one-legged knee extensor exercise.......05) in the contracting muscle, whereas it was unchanged in the non-contracting muscle. The uptake of plasma NEFA, as well as the proportion directed towards oxidation, was higher in the exercising compared to the non-exercising leg, whereas the rate of palmitate incorporation into mTAG was fourfold lower (0.70 +/- 0...

Skeletal muscle microRNA and messenger RNA profiling in cofilin-2 deficient mice reveals cell cycle dysregulation hindering muscle regeneration.

Directory of Open Access Journals (Sweden)

Sarah U Morton

Full Text Available Congenital myopathies are rare skeletal muscle diseases presenting in early age with hypotonia and weakness often linked to a genetic defect. Mutations in the gene for cofilin-2 (CFL2 have been identified in several families as a cause of congenital myopathy with nemaline bodies and cores. Here we explore the global messenger and microRNA expression patterns in quadriceps muscle samples from cofillin-2-null mice and compare them with sibling-matched wild-type mice to determine the molecular pathways and mechanisms involved. Cell cycle processes are markedly dysregulated, with altered expression of genes involved in mitotic spindle formation, and evidence of loss of cell cycle checkpoint regulation. Importantly, alterations in cell cycle, apoptosis and proliferation pathways are present in both mRNA and miRNA expression patterns. Specifically, p21 transcript levels were increased, and the expression of p21 targets, such as cyclin D and cyclin E, was decreased. We therefore hypothesize that deficiency of cofilin-2 is associated with interruption of the cell cycle at several checkpoints, hindering muscle regeneration. Identification of these pathways is an important step towards developing appropriate therapies against various congenital myopathies.

Different types of bursting calcium oscillations in non-excitable cells

International Nuclear Information System (INIS)

Perc, Matjaz; Marhl, Marko

2003-01-01

In the paper different types of bursting Ca 2+ oscillations are presented. We analyse bursting behaviour in four recent mathematical models for Ca 2+ oscillations in non-excitable cells. Separately, regular, quasi-periodic, and chaotic bursting Ca 2+ oscillations are classified into several subtypes. The classification is based on the dynamics of separated fast and slow subsystems, the so-called fast-slow burster analysis. For regular bursting Ca 2+ oscillations two types of bursting are specified: Point-Point and Point-Cycle bursting. In particular, the slow passage effect, important for the Hopf-Hopf and SubHopf-SubHopf bursting subtypes, is explained by local divergence calculated for the fast subsystem. Quasi-periodic bursting Ca 2+ oscillations can be found in only one of the four studied mathematical models and appear via a homoclinic bifurcation with a homoclinic torus structure. For chaotic bursting Ca 2+ oscillations, we found that bursting patterns resulting from the period doubling root to chaos considerably differ from those appearing via intermittency and have to be treated separately. The analysis and classification of different types of bursting Ca 2+ oscillations provides better insight into mechanisms of complex intra- and intercellular Ca 2+ signalling. This improves our understanding of several important biological phenomena in cellular signalling like complex frequency-amplitude signal encoding and synchronisation of intercellular signal transduction between coupled cells in tissue

Life without double-headed non-muscle myosin II motor proteins

Science.gov (United States)

Betapudi, Venkaiah

2014-07-01

Non-muscle myosin II motor proteins (myosin IIA, myosin IIB, and myosin IIC) belong to a class of molecular motor proteins that are known to transduce cellular free-energy into biological work more efficiently than man-made combustion engines. Nature has given a single myosin II motor protein for lower eukaryotes and multiple for mammals but none for plants in order to provide impetus for their life. These specialized nanomachines drive cellular activities necessary for embryogenesis, organogenesis, and immunity. However, these multifunctional myosin II motor proteins are believed to go awry due to unknown reasons and contribute for the onset and progression of many autosomal-dominant disorders, cataract, deafness, infertility, cancer, kidney, neuronal, and inflammatory diseases. Many pathogens like HIV, Dengue, hepatitis C, and Lymphoma viruses as well as Salmonella and Mycobacteria are now known to take hostage of these dedicated myosin II motor proteins for their efficient pathogenesis. Even after four decades since their discovery, we still have a limited knowledge of how these motor proteins drive cell migration and cytokinesis. We need to enrich our current knowledge on these fundamental cellular processes and develop novel therapeutic strategies to fix mutated myosin II motor proteins in pathological conditions. This is the time to think how to relieve the hijacked myosins from pathogens in order to provide a renewed impetus for patients’ life. Understanding how to steer these molecular motors in proliferating and differentiating stem cells will improve stem cell based-therapeutics development. Given the plethora of cellular activities non-muscle myosin motor proteins are involved in, their importance is apparent for human life.

Life without double-headed non-muscle myosin II motor proteins

Directory of Open Access Journals (Sweden)

Venkaiah eBetapudi

2014-07-01

Full Text Available Non-muscle myosin II motor proteins (myosin IIA, myosin IIB, and myosin IIC belong to a class of molecular motor proteins that are known to transduce cellular free-energy into biological work more efficiently than man-made combustion engines. Nature has given a single myosin II motor protein for lower eukaryotes and multiple for mammals but none for plants in order to provide impetus for their life. These specialized nanomachines drive cellular activities necessary for embryogenesis, organogenesis, and immunity. However, these multifunctional myosin II motor proteins are believed to go awry due to unknown reasons and contribute for the onset and progression of many autosomal-dominant disorders, cataract, deafness, infertility, cancer, kidney, neuronal, and inflammatory diseases. Many pathogens like HIV, Dengue, hepatitis C, and Lymphoma viruses as well as Salmonella and Mycobacteria are now known to take hostage of these dedicated myosin II motor proteins for their efficient pathogenesis. Even after four decades since their discovery, we still have a limited knowledge of how these motor proteins drive cell migration and cytokinesis. We need to enrich our current knowledge on these fundamental cellular processes and develop novel therapeutic strategies to fix mutated myosin II motor proteins in pathological conditions. This is the time to think how to relieve the hijacked myosins from pathogens in order to provide a renewed impetus for patients’ life. Understanding how to steer these molecular motors in proliferating and differentiating stem cells will improve stem cell based-therapeutics development. Given the plethora of cellular activities non-muscle myosin motor proteins are involved in, their importance is apparent for human life.

Fetal stem cells and skeletal muscle regeneration: a therapeutic approach

Directory of Open Access Journals (Sweden)

Michela ePozzobon

2014-08-01

Full Text Available More than 40% of the body mass is represented by muscle tissue, which possesses the innate ability to regenerate after damage through the activation of muscle specific stem cell, namely satellite cells. Muscle diseases, in particular chronic degenerative state of skeletal muscle such as dystrophies, lead to a perturbation of the regenerative process, which causes the premature exhaustion of satellite cell reservoir due to continue cycles of degeneration/regeneration. Nowadays, the research is focused on different therapeutic approaches, ranging from gene and cell to pharmacological therapy, but still there is not a definitive cure in particular for genetic muscle disease. Taking this in mind, in this article we will give special consideration to muscle diseases and the use of fetal derived stem cells as new approach for therapy. Cells of fetal origin, from cord blood to placenta and amniotic fluid, can be easily obtained without ethical concern, expanded and differentiated in culture, and possess immunemodulatory properties. The in vivo approach in animal models can be helpful to study the mechanism underneath the operating principle of the stem cell reservoir, namely the niche, which holds great potential to understand the onset of muscle pathologies.

Effects of cyclic stretch on proliferation of mesenchymal stem cells and their differentiation to smooth muscle cells

International Nuclear Information System (INIS)

Ghazanfari, Samane; Tafazzoli-Shadpour, Mohammad; Shokrgozar, Mohammad Ali

2009-01-01

Bone marrow mesenchymal stem cells (MSCs) are capable of differentiating into a variety of cell types such as vascular smooth muscle cells (SMCs). In this study, we investigated influence of cyclic stretch on proliferation of hMSCs for different loading conditions, alignment of actin filaments, and consequent differentiation to SMCs. Isolated cells from bone marrow were exposed to cyclic stretch utilizing a customized device. Cell proliferation was examined by MTT assay, alignment of actin fibers by a designed image processing code, and cell differentiation by fluorescence staining. Results indicated promoted proliferation of hMSCs by cyclic strain, enhanced by elevated strain amplitude and number of cycles. Such loading regulated smooth muscle α-actin, and reoriented actin fibers. Cyclic stretch led to differentiation of hMSCs to SMCs without addition of growth factor. It was concluded that applying appropriate loading treatment on hMSCs could enhance proliferation capability, and produce functional SMCs for engineered tissues.

Stochastic cellular automata model of cell migration, proliferation and differentiation: validation with in vitro cultures of muscle satellite cells.

Science.gov (United States)

Garijo, N; Manzano, R; Osta, R; Perez, M A

2012-12-07

Cell migration and proliferation has been modelled in the literature as a process similar to diffusion. However, using diffusion models to simulate the proliferation and migration of cells tends to create a homogeneous distribution in the cell density that does not correlate to empirical observations. In fact, the mechanism of cell dispersal is not diffusion. Cells disperse by crawling or proliferation, or are transported in a moving fluid. The use of cellular automata, particle models or cell-based models can overcome this limitation. This paper presents a stochastic cellular automata model to simulate the proliferation, migration and differentiation of cells. These processes are considered as completely stochastic as well as discrete. The model developed was applied to predict the behaviour of in vitro cell cultures performed with adult muscle satellite cells. Moreover, non homogeneous distribution of cells has been observed inside the culture well and, using the above mentioned stochastic cellular automata model, we have been able to predict this heterogeneous cell distribution and compute accurate quantitative results. Differentiation was also incorporated into the computational simulation. The results predicted the myotube formation that typically occurs with adult muscle satellite cells. In conclusion, we have shown how a stochastic cellular automata model can be implemented and is capable of reproducing the in vitro behaviour of adult muscle satellite cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Inflammation induced by mast cell deficiency rather than the loss of interstitial cells of Cajal causes smooth muscle dysfunction in W/Wv mice

Science.gov (United States)

Winston, John H.; Chen, Jinghong; Shi, Xuan-Zheng; Sarna, Sushil K.

2014-01-01

The initial hypothesis suggested that the interstitial cells of Cajal (ICC) played an essential role in mediating enteric neuronal input to smooth muscle cells. Much information for this hypothesis came from studies in W/Wv mice lacking ICC. However, mast cells, which play critical roles in regulating inflammation in their microenvironment, are also absent in W/Wv mice. We tested the hypothesis that the depletion of mast cells in W/Wv mice generates inflammation in fundus muscularis externa (ME) that impairs smooth muscle reactivity to Ach, independent of the depletion of ICC. We performed experiments on the fundus ME from wild type (WT) and W/Wv mice before and after reconstitution of mast cells by bone marrow transplant. We found that mast cell deficiency in W/Wv mice significantly increased COX-2 and iNOS expression and decreased smooth muscle reactivity to Ach. Mast cell reconstitution or concurrent blockade of COX-2 and iNOS restored smooth muscle contractility without affecting the suppression of c-kit in W/Wv mice. The expression of nNOS and ChAT were suppressed in W/Wv mice; mast cell reconstitution did not restore them. We conclude that innate inflammation induced by mast cell deficiency in W/Wv mice impairs smooth muscle contractility independent of ICC deficiency. The impairment of smooth muscle contractility and the suppression of the enzymes regulating the synthesis of Ach and NO in W/Wv mice need to be considered in evaluating the role of ICC in regulating smooth muscle and enteric neuronal function in W/Wv mice. PMID:24550836

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells

KAUST Repository

Castagnetti, Francesco

2017-06-13

Increasing evidence points to autophagy as a crucial regulatory process to preserve tissue homeostasis. It is known that autophagy is involved in skeletal muscle development and regeneration, and the autophagic process has been described in several muscular pathologies and agerelated muscle disorders. A recently described block of the autophagic process that correlates with the functional exhaustion of satellite cells during muscle repair supports the notion that active autophagy is coupled with productive muscle regeneration. These data uncover the crucial role of autophagy in satellite cell activation during muscle regeneration in both normal and pathological conditions, such as muscular dystrophies. Here, we provide a protocol to monitor the autophagic process in the adult Muscle Stem Cell (MuSC) compartment during muscle regenerative conditions. This protocol describes the setup methodology to perform in situ immunofluorescence imaging of LC3, an autophagy marker, and MyoD, a myogenic lineage marker, in muscle tissue sections from control and injured mice. The methodology reported allows for monitoring the autophagic process in one specific cell compartment, the MuSC compartment, which plays a central role in orchestrating muscle regeneration.

A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction.

Directory of Open Access Journals (Sweden)

Prabhat Tiwari

Full Text Available Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV and BM-40 from hemocytes and fat cells.

Overexpression of SMPX in adult skeletal muscle does not change skeletal muscle fiber type or size.

Directory of Open Access Journals (Sweden)

Einar Eftestøl

Full Text Available Mechanical factors such as stretch are thought to be important in the regulation of muscle phenotype. Small muscle protein X-linked (SMPX is upregulated by stretch in skeletal muscle and has been suggested to serve both as a transcription factor and a mechanosensor, possibly giving rise to changes in both fiber size and fiber type. We have used in vivo confocal imaging to study the subcellular localization of SMPX in skeletal muscle fibers of adult rats using a SMPX-EGFP fusion protein. The fusion protein was localized predominantly in repetitive double stripes flanking the Z-disc, and was excluded from all nuclei. This localization would be consistent with SMPX being a mechanoreceptor, but not with SMPX playing a role as a transcription factor. In vivo overexpression of ectopic SMPX in skeletal muscle of adult mice gave no significant changes in fiber type distribution or cross sectional area, thus a role of SMPX in regulating muscle phenotype remains unclear.

Muscle-specific integrins in masseter muscle fibers of chimpanzees: an immunohistochemical study.

Directory of Open Access Journals (Sweden)

Gianluigi Vaccarino

2010-05-01

differentiation, and cell-extracellular matrix interactions. Our results demonstrated a different quantitative composition of integrins, in alpha male in respect to human and non-alpha male, hypothesizing that the MYH16 gene could modify the expression of integrins, influencing, in turn, the phenotype of muscle. In this way, alpha 7A-and beta 1A-integrin could determine the presence of type II fibers and then they could play a key role in the determination of contraction force. Then, MYH16 gene could be a common interactor of signalling between sarcoglycans and integrins in chimpanzee muscles.

Reconstruction of radical prostatectomy-induced urethral damage using skeletal muscle-derived multipotent stem cells.

Science.gov (United States)

Hoshi, Akio; Tamaki, Tetsuro; Tono, Kayoko; Okada, Yoshinori; Akatsuka, Akira; Usui, Yukio; Terachi, Toshiro

2008-06-15

Postoperative damage of the urethral rhabdosphincter (URS) and neurovascular bundle (NVB) is a major operative complication of radical prostatectomy. It is generally recognized to be caused by unavoidable surgical damage to the muscle-nerve-blood vessel units around the urethra. We attempted to treat this damage using skeletal muscle-derived stem cells, which are able to reconstitute muscle-nerve-blood vessel units. Cells were enzymatically extracted and sorted by flow cytometry as CD34/45 (Sk-34) and CD34/45 (Sk-DN) cells from green fluorescent protein transgenic mice and rats. URS-NVB damage was induced by manually removing one-third of the total URS and unilateral invasion of NVB in wild-type Sprague-Dawley and node rats. Freshly isolated Sk-34, Sk-34+Sk-DN cells, and cultured Sk-DN cells were directly transplanted into the damaged portion. At 4 and 12 weeks after transplantation, urethral pressure profile by electrical stimulation through the sacral surface (L6-S1) was evaluated as functional recovery. The recovery ratio in the control and transplanted groups was 37.6% and 72.9%, at 4 weeks, and 41.6% and 78.4% at 12 weeks, respectively (Pcells differentiated into numerous skeletal muscle fibers having neuromuscular junctions (innervation) and nerve bundle-related Schwann cells and perineurium, and blood vessel-related endothelial cells and pericyte around the urethra. Thus, we conclude that transplantation of skeletal muscle-derived multipotent Sk-34 and Sk-DN cells is potentially useful for the reconstitution of postoperative damage of URS and NVB after radical prostatectomy.

Role of ERK/MAPK in endothelin receptor signaling in human aortic smooth muscle cells

DEFF Research Database (Denmark)

Chen, Qing-wen; Edvinsson, Lars; Xu, Cang-Bao

2009-01-01

muscle cells (VSMCs) through activation of endothelin type A (ETA) and type B (ETB) receptors. The extracellular signal-regulated kinase 1 and 2 (ERK1/2) mitogen-activated protein kinases (MAPK) are involved in ET-1-induced VSMC contraction and proliferation. This study was designed to investigat...

Muscle dysmorphia in Hungarian non-competitive male bodybuilders.

Science.gov (United States)

Babusa, B; Túry, F

2012-03-01

Muscle dysmorphia (MD) has been described as a male body image disorder, characterized by a pathological preoccupation with muscle size. The aim of the study was to examine the MD features, eating disorder characteristics and body attitudes in non-competitive male bodybuilders in a Hungarian sample. Sixty male bodybuilders and 60 undergraduate university students completed the self-report questionnaires of the Muscle Appearance Satisfaction Scale, the Body Attitude Test and the Eating Disorders Inventory. MD was associated with current bodybuilding activity, higher ideal body weight and eating disorder characteristics. Moreover, current selfreported steroid users displayed higher tendency for MD symptoms than self-reported steroid non-users. Results emphasize the relationship between MD symptoms, eating disorder characteristics and steroid use. MD and body image related concerns among men could be a wide-spread phenomena also in the Central-Eastern European region.

Impact of Perturbed Pancreatic β-Cell Cholesterol Homeostasis on Adipose Tissue and Skeletal Muscle Metabolism

Science.gov (United States)

Cochran, Blake J.; Hou, Liming; Manavalan, Anil Paul Chirackal; Moore, Benjamin M.; Tabet, Fatiha; Sultana, Afroza; Cuesta Torres, Luisa; Tang, Shudi; Shrestha, Sudichhya; Senanayake, Praween; Patel, Mili; Ryder, William J.; Bongers, Andre; Maraninchi, Marie; Wasinger, Valerie C.; Westerterp, Marit; Tall, Alan R.; Barter, Philip J.

2016-01-01

Elevated pancreatic β-cell cholesterol levels impair insulin secretion and reduce plasma insulin levels. This study establishes that low plasma insulin levels have a detrimental effect on two major insulin target tissues: adipose tissue and skeletal muscle. Mice with increased β-cell cholesterol levels were generated by conditional deletion of the ATP-binding cassette transporters, ABCA1 and ABCG1, in β-cells (β-DKO mice). Insulin secretion was impaired in these mice under basal and high-glucose conditions, and glucose disposal was shifted from skeletal muscle to adipose tissue. The β-DKO mice also had increased body fat and adipose tissue macrophage content, elevated plasma interleukin-6 and MCP-1 levels, and decreased skeletal muscle mass. They were not, however, insulin resistant. The adipose tissue expansion and reduced skeletal muscle mass, but not the systemic inflammation or increased adipose tissue macrophage content, were reversed when plasma insulin levels were normalized by insulin supplementation. These studies identify a mechanism by which perturbation of β-cell cholesterol homeostasis and impaired insulin secretion increase adiposity, reduce skeletal muscle mass, and cause systemic inflammation. They further identify β-cell dysfunction as a potential therapeutic target in people at increased risk of developing type 2 diabetes. PMID:27702832

Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration.

Science.gov (United States)

Fazal, Fabeha; Bijli, Kaiser M; Murrill, Matthew; Leonard, Antony; Minhajuddin, Mohammad; Anwar, Khandaker N; Finkelstein, Jacob N; Watterson, D Martin; Rahman, Arshad

2013-01-01

The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation.

Molecular and cell-based therapies for muscle degenerations: a road under construction.

Science.gov (United States)

Berardi, Emanuele; Annibali, Daniela; Cassano, Marco; Crippa, Stefania; Sampaolesi, Maurilio

2014-01-01

Despite the advances achieved in understanding the molecular biology of muscle cells in the past decades, there is still need for effective treatments of muscular degeneration caused by muscular dystrophies and for counteracting the muscle wasting caused by cachexia or sarcopenia. The corticosteroid medications currently in use for dystrophic patients merely help to control the inflammatory state and only slightly delay the progression of the disease. Unfortunately, walkers and wheel chairs are the only options for such patients to maintain independence and walking capabilities until the respiratory muscles become weak and the mechanical ventilation is needed. On the other hand, myostatin inhibition, IL-6 antagonism and synthetic ghrelin administration are examples of promising treatments in cachexia animal models. In both dystrophies and cachectic syndrome the muscular degeneration is extremely relevant and the translational therapeutic attempts to find a possible cure are well defined. In particular, molecular-based therapies are common options to be explored in order to exploit beneficial treatments for cachexia, while gene/cell therapies are mostly used in the attempt to induce a substantial improvement of the dystrophic muscular phenotype. This review focuses on the description of the use of molecular administrations and gene/stem cell therapy to treat muscular degenerations. It reviews previous trials using cell delivery protocols in mice and patients starting with the use of donor myoblasts, outlining the likely causes for their poor results and briefly focusing on satellite cell studies that raise new hope. Then it proceeds to describe recently identified stem/progenitor cells, including pluripotent stem cells and in relationship to their ability to home within a dystrophic muscle and to differentiate into skeletal muscle cells. Different known features of various stem cells are compared in this perspective, and the few available examples of their use in

Muscle fibre capillarization is a critical factor in muscle fibre hypertrophy during resistance exercise training in older men.

Science.gov (United States)

Snijders, Tim; Nederveen, Joshua P; Joanisse, Sophie; Leenders, Marika; Verdijk, Lex B; van Loon, Luc J C; Parise, Gianni

2017-04-01

Adequate muscle fibre perfusion is critical for the maintenance of muscle mass; it is essential in the rapid delivery of oxygen, nutrients and growth factors to the muscle, stimulating muscle fibre growth. Muscle fibre capillarization is known to decrease substantially with advancing age. However, whether (relative) low muscle fibre capillarization negatively impacts the muscle hypertrophic response following resistance exercise training in older adults is unknown. Twenty-two healthy older men (71 ± 1 years) performed 24 weeks of progressive resistance type exercise training. To assess the change in muscle fibre characteristics, percutaneous biopsies from the vastus lateralis muscle were taken before and following 12 and 24 weeks of the intervention programme. A comparison was made between participants who had a relatively low type II muscle fibre capillary-to-fibre perimeter exchange index (CFPE; LOW group) and high type II muscle fibre CFPE (HIGH group) at baseline. Type I and type II muscle fibre size, satellite cell, capillary content and distance between satellite cells to the nearest capillary were determined by immunohistochemistry. Overall, type II muscle fibre size (from 5150 ± 234 to 6719 ± 446 µm 2 , P muscle fibre, P muscle fibre capillarization, whereas muscle fibre size (from 5170 ± 390 to 7133 ± 314 µm 2 , P muscle fibre, P muscle fibre capillarization were observed in response to 12 and 24 weeks of resistance exercise training in both the LOW and HIGH group. Type II muscle fibre capillarization at baseline may be a critical factor for allowing muscle fibre hypertrophy to occur during prolonged resistance exercise training in older men. © 2016 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

Requirement of myomaker-mediated stem cell fusion for skeletal muscle hypertrophy.

Science.gov (United States)

Goh, Qingnian; Millay, Douglas P

2017-02-10

Fusion of skeletal muscle stem/progenitor cells is required for proper development and regeneration, however the significance of this process during adult muscle hypertrophy has not been explored. In response to muscle overload after synergist ablation in mice, we show that myomaker, a muscle specific membrane protein essential for myoblast fusion, is activated mainly in muscle progenitors and not myofibers. We rendered muscle progenitors fusion-incompetent through genetic deletion of myomaker in muscle stem cells and observed a complete reduction of overload-induced hypertrophy. This blunted hypertrophic response was associated with a reduction in Akt and p70s6k signaling and protein synthesis, suggesting a link between myonuclear accretion and activation of pro-hypertrophic pathways. Furthermore, fusion-incompetent muscle exhibited increased fibrosis after muscle overload, indicating a protective role for normal stem cell activity in reducing myofiber strain associated with hypertrophy. These findings reveal an essential contribution of myomaker-mediated stem cell fusion during physiological adult muscle hypertrophy.

Contractile properties and sarcoplasmic reticulum calcium content in type I and type II skeletal muscle fibres in active aged humans.

Science.gov (United States)

Lamboley, C R; Wyckelsma, V L; Dutka, T L; McKenna, M J; Murphy, R M; Lamb, G D

2015-06-01

Muscle weakness in old age is due in large part to an overall loss of skeletal muscle tissue, but it remains uncertain how much also stems from alterations in the properties of the individual muscle fibres. This study examined the contractile properties and amount of stored intracellular calcium in single muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) adults. The maximum level of force production (per unit cross-sectional area) in fast twitch fibres in Old subjects was lower than in Young subjects, and the fibres were also less sensitive to activation by calcium. The amount of calcium stored inside muscle fibres and available to trigger contraction was also lower in both fast- and slow-twitch muscle fibres in the Old subjects. These findings indicate that muscle weakness in old age stems in part from an impaired capacity for force production in the individual muscle fibres. This study examined the contractile properties and sarcoplasmic reticulum (SR) Ca(2+) content in mechanically skinned vastus lateralis muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) humans to investigate whether changes in muscle fibre properties contribute to muscle weakness in old age. In type II fibres of Old subjects, specific force was reduced by ∼17% and Ca(2+) sensitivity was also reduced (pCa50 decreased ∼0.05 pCa units) relative to that in Young. S-Glutathionylation of fast troponin I (TnIf ) markedly increased Ca(2+) sensitivity in type II fibres, but the increase was significantly smaller in Old versus Young (+0.136 and +0.164 pCa unit increases, respectively). Endogenous and maximal SR Ca(2+) content were significantly smaller in both type I and type II fibres in Old subjects. In fibres of Young, the SR could be nearly fully depleted of Ca(2+) by a combined caffeine and low Mg(2+) stimulus, whereas in fibres of Old the amount of non-releasable Ca(2+) was significantly increased (by > 12% of endogenous Ca(2+) content). Western

Type grouping in skeletal muscles after experimental reinnervation: another explanation

NARCIS (Netherlands)

Vleggeert-lankamp, C.L.A.M.; de Ruiter, G.C.W.; Wolfs, J.F.C.; Pêgo, A.P.; Feirabend, H.K.P.; Lakke, E.A.J.F.; Malessy, M.J.A.

2005-01-01

Type grouping signifies clustering of muscle fibres of the same metabolic type, and is a frequent finding in reinnervated muscles. To elucidate the mechanism behind it, the rat sciatic nerve was either autografted or grafted with hollow synthetic nerve grafts. Twelve weeks later the number and fibre

Histochemical and functional fibre typing of the rabbit masseter muscle

NARCIS (Netherlands)

Bredman, J. J.; Weijs, W. A.; Moorman, A. F.; Brugman, P.

1990-01-01

The fibre-type distribution of the masseter muscle of the rabbit was studied by means of the myosin-ATPase and succinate dehydrogenase reactions. Six different fibre types were found and these were unequally distributed between and within the anatomical compartments of the muscle. Most of the

Non-Coding RNAs in Muscle Dystrophies

Directory of Open Access Journals (Sweden)

Alessandra Ferlini

2013-09-01

Full Text Available ncRNAs are the most recently identified class of regulatory RNAs with vital functions in gene expression regulation and cell development. Among the variety of roles they play, their involvement in human diseases has opened new avenues of research towards the discovery and development of novel therapeutic approaches. Important data come from the field of hereditary muscle dystrophies, like Duchenne muscle dystrophy and Myotonic dystrophies, rare diseases affecting 1 in 7000–15,000 newborns and is characterized by severe to mild muscle weakness associated with cardiac involvement. Novel therapeutic approaches are now ongoing for these diseases, also based on splicing modulation. In this review we provide an overview about ncRNAs and their behavior in muscular dystrophy and explore their links with diagnosis, prognosis and treatments, highlighting the role of regulatory RNAs in these pathologies.

Long Non-Coding RNA MEG3 Downregulation Triggers Human Pulmonary Artery Smooth Muscle Cell Proliferation and Migration via the p53 Signaling Pathway

Directory of Open Access Journals (Sweden)

Zengxian Sun

2017-08-01

Full Text Available Background/Aims: Increasing evidence has demonstrated a significant role of long non-coding RNAs (lncRNAs in diverse biological processes, and many of which are likely to have functional roles in vascular remodeling. However, their functions in pulmonary arterial hypertension (PAH remain largely unknown. Pulmonary vascular remodeling is an important pathological feature of PAH, leading to increased vascular resistance and reduced compliance. Pulmonary artery smooth muscle cells (PASMCs dysfunction is involved in vascular remodeling. Long noncoding RNAs are potential regulators of PASMCs function. Herein, we determined whether long noncoding RNA–maternally expressed gene 3 (MEG3 was involved in PAH-related vascular remodeling. Methods: The arterial wall thickness was examined by hematoxylin and eosin (H&E staining in distal pulmonary arteries (PAs isolated from lungs of healthy volunteers and PAH patients. The expression level of MEG3 was analyzed by qPCR. The effects of MEG3 on human PASMCs were assessed by cell counting Kit-8 assay, BrdU incorporation assay, flow cytometry, scratch-wound assay, immunofluorescence, and western blotting in human PASMCs. Results: We revealed that the expression of MEG3 was significantly downregulated in lung and PAs of patients with PAH. MEG3 knockdown affected PASMCs proliferation and migration in vitro. Moreover, inhibition of MEG3 regulated the cell cycle progression and made more smooth muscle cells from the G0/G1 phase to the G2/M+S phase and the process could stimulate the expression of PCNA, Cyclin A and Cyclin E. In addition, we found that the p53 pathway was involved in MEG3–induced smooth muscle cell proliferation. Conclusions: This study identified MEG3 as a critical regulator in PAH and demonstrated the potential of gene therapy and drug development for treating PAH.

Aging is associated with diminished muscle re-growth and myogenic precursor cell expansion in the early recovery phase after immobility-induced atrophy in human skeletal muscle

DEFF Research Database (Denmark)

Suetta, Charlotte Arneboe; Frandsen, Ulrik; Mackey, Abigail L

2013-01-01

Recovery of skeletal muscle mass from immobilisation-induced atrophy is faster in young than older individuals, yet the cellular mechanisms remain unknown. We examined the cellular and molecular regulation of muscle recovery in young and old human subjects subsequent to 2 weeks of immobility...... expression analysis of key growth and transcription factors associated with local skeletal muscle milieu were performed after 2 weeks immobility (Imm) and following 3 days (+3d) and 4 weeks (+4wks) of re-training. OM demonstrated no detectable gains in MFA (VL muscle) and no increases in number of Pax7......-induced muscle atrophy. Re-training consisted of 4 weeks of supervised resistive exercise in 9 older (OM: 67.3yrs, range 61-74) and 11 young (YM: 24.4yrs, range 21-30) males. Measures of myofiber area (MFA), Pax7-positive satellite cells (SC) associated with type I and type II muscle fibres, as well as gene...

Cytokine-induced differentiation of multipotent adult progenitor cells into functional smooth muscle cells.

Science.gov (United States)

Ross, Jeffrey J; Hong, Zhigang; Willenbring, Ben; Zeng, Lepeng; Isenberg, Brett; Lee, Eu Han; Reyes, Morayma; Keirstead, Susan A; Weir, E Kenneth; Tranquillo, Robert T; Verfaillie, Catherine M

2006-12-01

Smooth muscle formation and function are critical in development and postnatal life. Hence, studies aimed at better understanding SMC differentiation are of great importance. Here, we report that multipotent adult progenitor cells (MAPCs) isolated from rat, murine, porcine, and human bone marrow demonstrate the potential to differentiate into cells with an SMC-like phenotype and function. TGF-beta1 alone or combined with PDGF-BB in serum-free medium induces a temporally correct expression of transcripts and proteins consistent with smooth muscle development. Furthermore, SMCs derived from MAPCs (MAPC-SMCs) demonstrated functional L-type calcium channels. MAPC-SMCs entrapped in fibrin vascular molds became circumferentially aligned and generated force in response to KCl, the L-type channel opener FPL64176, or the SMC agonists 5-HT and ET-1, and exhibited complete relaxation in response to the Rho-kinase inhibitor Y-27632. Cyclic distention (5% circumferential strain) for 3 weeks increased responses by 2- to 3-fold, consistent with what occurred in neonatal SMCs. These results provide evidence that MAPC-SMCs are phenotypically and functionally similar to neonatal SMCs and that the in vitro MAPC-SMC differentiation system may be an ideal model for the study of SMC development. Moreover, MAPC-SMCs may lend themselves to tissue engineering applications.

Skeletal muscle stem cells from animals I. Basic cell biology

Science.gov (United States)

Skeletal muscle stem cells from food-producing animals have been of interest to agricultural life scientists seeking to develop a better understanding of the molecular regulation of lean tissue (skeletal muscle protein hypertrophy) and intramuscular fat (marbling) development. Enhanced understanding...

Molecular aging and rejuvenation of human muscle stem cells

DEFF Research Database (Denmark)

Carlson, Morgan E; Suetta, Charlotte; Conboy, Michael J

2009-01-01

. Our findings establish key evolutionarily conserved mechanisms of human stem cell aging. We find that satellite cells are maintained in aged human skeletal muscle, but fail to activate in response to muscle attrition, due to diminished activation of Notch compounded by elevated transforming growth...... factor beta (TGF-beta)/phospho Smad3 (pSmad3). Furthermore, this work reveals that mitogen-activated protein kinase (MAPK)/phosphate extracellular signal-regulated kinase (pERK) signalling declines in human muscle with age, and is important for activating Notch in human muscle stem cells. This molecular......Very little remains known about the regulation of human organ stem cells (in general, and during the aging process), and most previous data were collected in short-lived rodents. We examined whether stem cell aging in rodents could be extrapolated to genetically and environmentally variable humans...

Skeletal muscle repair in a mouse model of nemaline myopathy.

Science.gov (United States)

Sanoudou, Despina; Corbett, Mark A; Han, Mei; Ghoddusi, Majid; Nguyen, Mai-Anh T; Vlahovich, Nicole; Hardeman, Edna C; Beggs, Alan H

2006-09-01

Nemaline myopathy (NM), the most common non-dystrophic congenital myopathy, is a variably severe neuromuscular disorder for which no effective treatment is available. Although a number of genes have been identified in which mutations can cause NM, the pathogenetic mechanisms leading to the phenotypes are poorly understood. To address this question, we examined gene expression patterns in an NM mouse model carrying the human Met9Arg mutation of alpha-tropomyosin slow (Tpm3). We assessed five different skeletal muscles from affected mice, which are representative of muscles with differing fiber-type compositions, different physiological specializations and variable degrees of pathology. Although these same muscles in non-affected mice showed marked variation in patterns of gene expression, with diaphragm being the most dissimilar, the presence of the mutant protein in nemaline muscles resulted in a more similar pattern of gene expression among the muscles. This result suggests a common process or mechanism operating in nemaline muscles independent of the variable degrees of pathology. Transcriptional and protein expression data indicate the presence of a repair process and possibly delayed maturation in nemaline muscles. Markers indicative of satellite cell number, activated satellite cells and immature fibers including M-Cadherin, MyoD, desmin, Pax7 and Myf6 were elevated by western-blot analysis or immunohistochemistry. Evidence suggesting elevated focal repair was observed in nemaline muscle in electron micrographs. This analysis reveals that NM is characterized by a novel repair feature operating in multiple different muscles.

Protein Availability and Satellite Cell Dynamics in Skeletal Muscle.

Science.gov (United States)

Shamim, Baubak; Hawley, John A; Camera, Donny M

2018-06-01

Human skeletal muscle satellite cells are activated in response to both resistance and endurance exercise. It was initially proposed that satellite cell proliferation and differentiation were only required to support resistance exercise-induced hypertrophy. However, satellite cells may also play a role in muscle fibre remodelling after endurance-based exercise and extracellular matrix regulation. Given the importance of dietary protein, particularly branched chain amino acids, in supporting myofibrillar and mitochondrial adaptations to both resistance and endurance-based training, a greater understanding of how protein intake impacts satellite cell activity would provide further insight into the mechanisms governing skeletal muscle remodelling with exercise. While many studies have investigated the capacity for protein ingestion to increase post-exercise rates of muscle protein synthesis, few investigations have examined the role for protein ingestion to modulate satellite cell activity. Here we review the molecular mechanisms controlling the activation of satellite cells in response to mechanical stress and protein intake in both in vitro and in vivo models. We provide a mechanistic framework that describes how protein ingestion may enhance satellite activity and promote exercise adaptations in human skeletal muscle.

Trichomonas vaginalis and Tritrichomonas foetus: interaction with fibroblasts and muscle cells - new insights into parasite-mediated host cell cytotoxicity

Directory of Open Access Journals (Sweden)

Ricardo Chaves Vilela

2012-09-01

Full Text Available Trichomonas vaginalis and Tritrichomonas foetus are parasitic, flagellated protists that inhabit the urogenital tract of humans and bovines, respectively. T. vaginalis causes the most prevalent non-viral sexually transmitted disease worldwide and has been associated with an increased risk for human immunodeficiency virus-1 infection in humans. Infections by T. foetus cause significant losses to the beef industry worldwide due to infertility and spontaneous abortion in cows. Several studies have shown a close association between trichomonads and the epithelium of the urogenital tract. However, little is known concerning the interaction of trichomonads with cells from deeper tissues, such as fibroblasts and muscle cells. Published parasite-host cell interaction studies have reported contradictory results regarding the ability of T. foetus and T. vaginalis to interact with and damage cells of different tissues. In this study, parasite-host cell interactions were examined by culturing primary human fibroblasts obtained from abdominal biopsies performed during plastic surgeries with trichomonads. In addition, mouse 3T3 fibroblasts, primary chick embryo myogenic cells and L6 muscle cells were also used as models of target cells. The parasite-host cell cultures were processed for scanning and transmission electron microscopy and were tested for cell viability and cell death. JC-1 staining, which measures mitochondrial membrane potential, was used to determine whether the parasites induced target cell damage. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling staining was used as an indicator of chromatin damage. The colorimetric crystal violet assay was performed to ana-lyse the cytotoxicity induced by the parasite. The results showed that T. foetus and T. vaginalis adhered to and were cytotoxic to both fibroblasts and muscle cells, indicating that trichomonas infection of the connective and muscle tissues is likely to occur; such

Muscle fiber type proportion and size is not altered in mcardle disease.

Science.gov (United States)

Henning, Franclo; Cunninghame, Carol Anne; Martín, Miguel Angel; Rubio, Juan Carlos; Arenas, Joaquín; Lucia, Alejandro; HernáNdez-Laín, Aurelio; Kohn, Tertius Abraham

2017-06-01

McArdle disease is a metabolic myopathy that presents with exercise intolerance and episodic rhabdomyolysis. Excessive muscle recruitment has also been shown to be present during strenuous exercise, suggesting decreased power output. These findings could potentially be explained by either impaired contractility, decreased fiber size, or altered fiber type proportion. However, there is a paucity of data on the morphological features seen on muscle histology. We examined muscle biopsies of patients with McArdle disease from a Spanish cohort and compared the findings with healthy controls. We found no significant difference in the fiber type proportion or mean fiber size between McArdle patients and controls in the biceps brachii or vastus lateralis muscles. No alterations in muscle fiber type proportion or size were found on muscle histology of patients with McArdle disease. Future research should focus on assessment of muscle fiber contractility to investigate the functional impairment. Muscle Nerve 55: 916-918, 2017. © 2016 Wiley Periodicals, Inc.

Karakteristik Protein dan Nitrogen Non Protein Daging Ikan Cucut Lanyam (Charcharhinus limbatus (Characteristics of Protein and Non Protein Nitrogen in Lanyam Shark Muscle

Directory of Open Access Journals (Sweden)

Yuspihana Fitrial

2017-02-01

Based on protein solubility of Lanyam muscle at pH 1.5 to 12 obtained two points which is minimum solubility at pH 4.5 and pH 9. Based on the classification Osborn, Lanyam muscle contained albumin (28.64%, globulin (13:44%, prolamin (03.29%, glutelin (33.70%. Observation of non-protein nitrogen levels indicated that the washing process was very effective to reduce non-protein nitrogen levels up to 62.34% and urea levels up to 58% . Differential Scanning Calorimetry Study of Lanyam mince showed two types of protein that has a different stability to heat and after added 2.5% NaCl formed a peak which is a fusion of both these proteins

The Complex Role of Store Operated Calcium Entry Pathways and Related Proteins in the Function of Cardiac, Skeletal and Vascular Smooth Muscle Cells

Directory of Open Access Journals (Sweden)

Javier Avila-Medina

2018-03-01

Full Text Available Cardiac, skeletal, and smooth muscle cells shared the common feature of contraction in response to different stimuli. Agonist-induced muscle's contraction is triggered by a cytosolic free Ca2+ concentration increase due to a rapid Ca2+ release from intracellular stores and a transmembrane Ca2+ influx, mainly through L-type Ca2+ channels. Compelling evidences have demonstrated that Ca2+ might also enter through other cationic channels such as Store-Operated Ca2+ Channels (SOCCs, involved in several physiological functions and pathological conditions. The opening of SOCCs is regulated by the filling state of the intracellular Ca2+ store, the sarcoplasmic reticulum, which communicates to the plasma membrane channels through the Stromal Interaction Molecule 1/2 (STIM1/2 protein. In muscle cells, SOCCs can be mainly non-selective cation channels formed by Orai1 and other members of the Transient Receptor Potential-Canonical (TRPC channels family, as well as highly selective Ca2+ Release-Activated Ca2+ (CRAC channels, formed exclusively by subunits of Orai proteins likely organized in macromolecular complexes. This review summarizes the current knowledge of the complex role of Store Operated Calcium Entry (SOCE pathways and related proteins in the function of cardiac, skeletal, and vascular smooth muscle cells.

Muscle structure and stiffness assessment after botulinum toxin type A injection. A systematic review.

Science.gov (United States)

Mathevon, L; Michel, F; Decavel, P; Fernandez, B; Parratte, B; Calmels, P

2015-12-01

Botulinum toxin type A manages spasticity disorders in neurological central diseases. Some studies have reported that it might induce muscle changes. We present a literature review abiding by the PRISMA statement guidelines. The purpose was to explore the structural and passive biomechanical muscle properties after botulinum toxin type A injections in healthy and spastic limb muscles, on animals and humans, as well as methods for evaluating these properties. We searched the PubMed and Cochrane Library databases using the following keywords: "Botulinum toxin" AND ("muscle structure" OR "muscle atrophy") and, "Botulinum toxin" AND "muscle elasticity". From the 228 initially identified articles, 21 articles were included. Histological analyses were performed, especially on animals. A neurogenic atrophy systematically occurred. In humans, one year after a single injection, the histological recovery remained incomplete. Furthermore, 2D ultrasound analyses showed a reduction of the gastrocnemius thickness and pennation angle. MRI volumetric analysis evidenced muscular atrophy six months or one year after a single injection. Passive muscle stiffness depends on these structural changes. On the short term, the biomechanical analysis showed an elastic modulus increase in animals whereas no change was recorded in humans. On the short term, ultrasound elastography imaging showed a decreased elastic modulus. To date, few data are available, but all show a structural and mechanical muscle impact post injections, specifically muscle atrophy which can linger over time. Further studies are necessary to validate this element, and the possibility of change must be taken into account particularly with repeated injections. Thus, in clinical practice, 2D ultrasound and ultrasound elastography are two non-invasive techniques that will help physicians to develop an efficient long term monitoring. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Regional organization of fibre types in normal and reinnervated hindlimb muscles

NARCIS (Netherlands)

Wang, Liangchun

2001-01-01

The present thesis concerns the spatial distribution of the "slow" type I fibres within muscles of the hindlimb. It is known since long ago that some muscles may have strikingly heterogeneous distributions of type I and II fibres, but this phenomenon of "fibre type regionalization" has still not

Characterization of distinct mesenchymal-like cell populations from human skeletal muscle in situ and in vitro

Energy Technology Data Exchange (ETDEWEB)

Lecourt, Severine, E-mail: severine.lecourt@sls.aphp.fr [UPMC/AIM UMR S 974, Groupe Hospitalier Pitie-Salpetriere, Paris (France); INSERM U974, Groupe Hospitalier Pitie-Salpetriere, Paris (France); CNRS UMR 7215, Groupe Hospitalier Pitie-Salpetriere, Paris (France); Laboratoire de Therapie Cellulaire, Hopital Saint Louis, Paris (France); Marolleau, Jean-Pierre, E-mail: Marolleau.Jean-Pierre@chu-amiens.fr [Laboratoire de Therapie Cellulaire, Hopital Saint Louis, Paris (France); CHU Amiens Hopital Sud, Service d' Hematologie Clinique, UPJV, Amiens (France); Fromigue, Olivia, E-mail: olivia.fromigue@larib.inserm.fr [INSERM U606, Universite Paris 07, Hopital Lariboisiere, Paris (France); Vauchez, Karine, E-mail: k.vauchez@institut-myologie.org [UPMC/AIM UMR S 974, Groupe Hospitalier Pitie-Salpetriere, Paris (France); INSERM U974, Groupe Hospitalier Pitie-Salpetriere, Paris (France); CNRS UMR 7215, Groupe Hospitalier Pitie-Salpetriere, Paris (France); Genzyme S.A.S., Saint-Germain en Laye (France); Andriamanalijaona, Rina, E-mail: rinandria@yahoo.fr [Laboratoire de Biochimie des Tissus Conjonctifs, Faculte de Medecine, Caen (France); Ternaux, Brigitte, E-mail: brigitte.ternaux@orange.fr [Laboratoire de Therapie Cellulaire, Hopital Saint Louis, Paris (France); Lacassagne, Marie-Noelle, E-mail: mnlacassagne@free.fr [Laboratoire de Therapie Cellulaire, Hopital Saint Louis, Paris (France); Robert, Isabelle, E-mail: isa-robert@hotmail.fr [Laboratoire de Therapie Cellulaire, Hopital Saint Louis, Paris (France); Boumediene, Karim, E-mail: karim.boumediene@unicaen.fr [Laboratoire de Biochimie des Tissus Conjonctifs, Faculte de Medecine, Caen (France); Chereau, Frederic, E-mail: fchereau@pervasistx.com [Myosix S.A., Saint-Germain en Laye (France); Marie, Pierre, E-mail: pierre.marie@larib.inserm.fr [INSERM U606, Universite Paris 07, Hopital Lariboisiere, Paris (France); and others

2010-09-10

Human skeletal muscle is an essential source of various cellular progenitors with potential therapeutic perspectives. We first used extracellular markers to identify in situ the main cell types located in a satellite position or in the endomysium of the skeletal muscle. Immunohistology revealed labeling of cells by markers of mesenchymal (CD13, CD29, CD44, CD47, CD49, CD62, CD73, CD90, CD105, CD146, and CD15 in this study), myogenic (CD56), angiogenic (CD31, CD34, CD106, CD146), hematopoietic (CD10, CD15, CD34) lineages. We then analysed cell phenotypes and fates in short- and long-term cultures of dissociated muscle biopsies in a proliferation medium favouring the expansion of myogenic cells. While CD56{sup +} cells grew rapidly, a population of CD15{sup +} cells emerged, partly from CD56{sup +} cells, and became individualized. Both populations expressed mesenchymal markers similar to that harboured by human bone marrow-derived mesenchymal stem cells. In differentiation media, both CD56{sup +} and CD15{sup +} cells shared osteogenic and chondrogenic abilities, while CD56{sup +} cells presented a myogenic capacity and CD15{sup +} cells presented an adipogenic capacity. An important proportion of cells expressed the CD34 antigen in situ and immediately after muscle dissociation. However, CD34 antigen did not persist in culture and this initial population gave rise to adipogenic cells. These results underline the diversity of human muscle cells, and the shared or restricted commitment abilities of the main lineages under defined conditions.

Ameliorative effects of polyunsaturated fatty acids against palmitic acid-induced insulin resistance in L6 skeletal muscle cells

Directory of Open Access Journals (Sweden)

Sawada Keisuke

2012-03-01

Full Text Available Abstract Background Fatty acid-induced insulin resistance and impaired glucose uptake activity in muscle cells are fundamental events in the development of type 2 diabetes and hyperglycemia. There is an increasing demand for compounds including drugs and functional foods that can prevent myocellular insulin resistance. Methods In this study, we established a high-throughput assay to screen for compounds that can improve myocellular insulin resistance, which was based on a previously reported non-radioisotope 2-deoxyglucose (2DG uptake assay. Insulin-resistant muscle cells were prepared by treating rat L6 skeletal muscle cells with 750 μM palmitic acid for 14 h. Using the established assay, the impacts of several fatty acids on myocellular insulin resistance were determined. Results In normal L6 cells, treatment with saturated palmitic or stearic acid alone decreased 2DG uptake, whereas unsaturated fatty acids did not. Moreover, co-treatment with oleic acid canceled the palmitic acid-induced decrease in 2DG uptake activity. Using the developed assay with palmitic acid-induced insulin-resistant L6 cells, we determined the effects of other unsaturated fatty acids. We found that arachidonic, eicosapentaenoic and docosahexaenoic acids improved palmitic acid-decreased 2DG uptake at lower concentrations than the other unsaturated fatty acids, including oleic acid, as 10 μM arachidonic acid showed similar effects to 750 μM oleic acid. Conclusions We have found that polyunsaturated fatty acids, in particular arachidonic and eicosapentaenoic acids prevent palmitic acid-induced myocellular insulin resistance.

Protein turnover and cellular stress in mildly and severely affected muscles from patients with limb girdle muscular dystrophy type 2I.

Directory of Open Access Journals (Sweden)

Simon Hauerslev

Full Text Available Patients with Limb girdle muscular dystrophy type 2I (LGMD2I are characterized by progressive muscle weakness and wasting primarily in the proximal muscles, while distal muscles often are spared. Our aim was to investigate if wasting could be caused by impaired regeneration in the proximal compared to distal muscles. Biopsies were simultaneously obtained from proximal and distal muscles of the same patients with LGMD2I (n = 4 and healthy subjects (n = 4. The level of past muscle regeneration was evaluated by counting internally nucleated fibers and determining actively regenerating fibers by using the developmental markers embryonic myosin heavy chain (eMHC and neural cell adhesion molecule (NCAM and also assessing satellite cell activation status by myogenin positivity. Severe muscle histopathology was occasionally observed in the proximal muscles of patients with LGMD2I whereas distal muscles were always relatively spared. No difference was found in the regeneration markers internally nucleated fibers, actively regenerating fibers or activation status of satellite cells between proximal and distal muscles. Protein turnover, both synthesis and breakdown, as well as cellular stress were highly increased in severely affected muscles compared to mildly affected muscles. Our results indicate that alterations in the protein turnover and myostatin levels could progressively impair the muscle mass maintenance and/or regeneration resulting in gradual muscular atrophy.

Primary Type3 (Non-ABC, Non-GCB Subtype of Extranodal Diffuse Large B-Cell Lymphoma of the Thyroid Bearing No MYD88 Mutation by Padlock Probe Hybridization

Directory of Open Access Journals (Sweden)

Yukiko Nishi

2017-06-01

Full Text Available Primary extranodal malignant lymphoma of the thyroid is a rare entity composed of mostly neoplastic transformation of germinal center-like B cells (GCB or memory B cells. Other B-cell-type malignancies arising primarily in the thyroid have rarely been described. Immunohistochemical examination of autopsied primary malignant lymphoma of the thyroid in an 83-year-old Japanese female revealed the presence of a non-GCB subtype of diffuse large B-cell lymphoma (DLBCL without the typical codon 206 or 265 missense mutation of MYD88. The lack of the highly oncogenic MYD88 gene mutation, frequently observed in DLBCL of the activated B-cell (ABC subtype, and the detection of an extremely aggressive yet local clinical phenotype demonstrated that the present case was an exceptional entity of the type3 (non-GCB and non-ABC subtype.

Expression of uncoupling protein 1 in bovine muscle cells.

Science.gov (United States)

Abd Eldaim, M A; Hashimoto, O; Ohtsuki, H; Yamada, T; Murakami, M; Onda, K; Sato, R; Kanamori, Y; Qiao, Y; Tomonaga, S; Matsui, T; Funaba, M

2016-12-01

Uncoupling protein 1 (Ucp1) is predominantly expressed in brown/beige adipocytes in mammals. Although myogenic cells have been suggested to commit to a brown adipocyte lineage through the induction of Prdm16 expression, Prdm16 is also expressed in skeletal muscle. Thus, we examined expression of Ucp1 in bovine myogenic cells. Considering that Ucp1 is a principle molecule that induces energy expenditure in brown/beige adipocytes, expression of Ucp1 is not preferable in beef cattle because of potential decrease in energy (fattening) efficiency. The RT-PCR analyses revealed the expression of Ucp1 in the skeletal muscle of cattle; expression levels were markedly lower than those in the brown fat of calves. Immunohistochemical analyses showed that Ucp1 surrounded muscle fibers, but not adipocytes residing in skeletal muscle. Myosatellite cells cultured in myogenic medium showed an increase in the expression levels of myogenic regulatory factors ( levels were greater in cells after myogenic culture for 12 d than in those after myogenic culture for 6 d ( bovine skeletal muscle, which suggests the necessity for further studies on Ucp1-mediated energy expenditure in bovine skeletal muscle.

Skeletal Muscle-derived Hematopoietic Stem Cells: Muscular Dystrophy Therapy by Bone Marrow Transplantation

OpenAIRE

Asakura, Atsushi

2012-01-01

For postnatal growth and regeneration of skeletal muscle, satellite cells, a self-renewing pool of muscle stem cells, give rise to daughter myogenic precursor cells that contribute to the formation of new muscle fibers. In addition to this key myogenic cell class, adult skeletal muscle also contains hematopoietic stem cell and progenitor cell populations which can be purified as a side population (SP) fraction or as a hematopoietic marker CD45-positive cell population. These muscle-derived he...

Stem cell antigen-1 in skeletal muscle function.

Science.gov (United States)

Bernstein, Harold S; Samad, Tahmina; Cholsiripunlert, Sompob; Khalifian, Saami; Gong, Wenhui; Ritner, Carissa; Aurigui, Julian; Ling, Vivian; Wilschut, Karlijn J; Bennett, Stephen; Hoffman, Julien; Oishi, Peter

2013-08-15

Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1 in normal, post-natal muscle has not been thoroughly investigated. We systematically compared Sca-1-/- (KO) and Sca-1+/+ (WT) mice and hindlimb muscles to elucidate the tissue, contractile, and functional effects of Sca-1 in young and aging animals. Comparison of muscle volume, fibrosis, myofiber cross-sectional area, and Pax7+ myoblast number showed little differences between ages or genotypes. Exercise protocols, however, demonstrated decreased stamina in KO versus WT mice, with young KO mice achieving results similar to aging WT animals. In addition, KO mice did not improve with practice, while WT animals demonstrated conditioning over time. Surprisingly, myomechanical analysis of isolated muscles showed that KO young muscle generated more force and experienced less fatigue. However, KO muscle also demonstrated incomplete relaxation with fatigue. These findings suggest that Sca-1 is necessary for muscle conditioning with exercise, and that deficient conditioning in Sca-1 KO animals becomes more pronounced with age.

Muscular effects of vitamin D in young athletes and non-athletes and in the elderly.

Science.gov (United States)

Koundourakis, Nikolaos E; Avgoustinaki, Pavlina D; Malliaraki, Niki; Margioris, Andrew N

2016-10-01

Muscles are major targets of vitamin D. Exposure of skeletal muscles to vitamin D induces the expression of multiple myogenic transcription factors enhancing muscle cell proliferation and differentiation. At the same time vitamin D suppresses the expression of myostatin, a negative regulator of muscle mass. Moreover, vitamin D increases the number of type II or fast twitch muscle cells and in particular that of type IIA cells, while its deficiency causes type IIA cell atrophy. Furthermore, vitamin D supplementation in young males with low vitamin D levels increases the percentage of type IIA fibers in muscles, causing an increase in muscular high power output. Vitamin D levels are strongly associated with exercise performance in athletes and physically active individuals. In the elderly and in adults below the age of 65, several studies have established a close association between vitamin D levels and neuromuscular coordination. The aim of this review is to appraise our current understanding of the significance of vitamin D on muscular performance in both older and frail individuals as well as in younger adults, athletes or non-athletes with regard to both ordinary everyday musculoskeletal tasks and peak athletic performance.

NF-kappaB signaling mediates vascular smooth muscle endothelin type B receptor expression in resistance arteries

DEFF Research Database (Denmark)

Zheng, Jian-Pu; Zhang, Yaping; Edvinsson, Lars

2010-01-01

Vascular smooth muscle cells (SMC) endothelin type B (ET(B)) receptor upregulation results in strong vasoconstriction and reduction of local blood flow. We hypothesizes that the underlying molecular mechanisms involve transcriptional factor nuclear factor-kappaB (NF-kappaB) pathway. ET(B) recepto...

Down-regulation of lipoprotein lipase increases glucose uptake in L6 muscle cells

Energy Technology Data Exchange (ETDEWEB)

Lopez, Veronica; Saraff, Kumuda [Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262 (United States); Medh, Jheem D., E-mail: jheem.medh@csun.edu [Department of Chemistry and Biochemistry, California State University Northridge, Northridge, CA 91330-8262 (United States)

2009-11-06

Thiazolidinediones (TZDs) are synthetic hypoglycemic agents used to treat type 2 diabetes. TZDs target the peroxisome proliferator activated receptor-gamma (PPAR-{gamma}) and improve systemic insulin sensitivity. The contributions of specific tissues to TZD action, or the downstream effects of PPAR-{gamma} activation, are not very clear. We have used a rat skeletal muscle cell line (L6 cells) to demonstrate that TZDs directly target PPAR-{gamma} in muscle cells. TZD treatment resulted in a significant repression of lipoprotein lipase (LPL) expression in L6 cells. This repression correlated with an increase in glucose uptake. Down-regulation of LPL message and protein levels using siRNA resulted in a similar increase in insulin-dependent glucose uptake. Thus, LPL down-regulation improved insulin sensitivity independent of TZDs. This finding provides a novel method for the management of insulin resistance.

Immortalized human myotonic dystrophy muscle cell lines to assess therapeutic compounds

OpenAIRE

Arandel, Ludovic; Polay Espinoza, Micaela; Matloka, Magdalena; Bazinet, Audrey; De Dea Diniz, Damily; Naouar, Na?ra; Rau, Fr?d?rique; Jollet, Arnaud; Edom-Vovard, Fr?d?rique; Mamchaoui, Kamel; Tarnopolsky, Mark; Puymirat, Jack; Battail, Christophe; Boland, Anne; Deleuze, Jean-Francois

2017-01-01

International audience; Myotonic dystrophy type 1 (DM1) and type 2 (DM2) are autosomal dominant neuromuscular diseases caused by microsatellite expansions and belong to the family of RNA-dominant disorders. Availability of cellular models in which the DM mutation is expressed within its natural context is essential to facilitate efforts to identify new therapeutic compounds. Here, we generated immortalized DM1 and DM2 human muscle cell lines that display nuclear RNA aggregates of expanded rep...

Phenotypic modulation of smooth muscle cells during formation of neointimal thickenings following vascular injury.

Science.gov (United States)

Thyberg, J

1998-07-01

Smooth muscle cells build up the media of mammalian arteries and constitute one of the principal cell types in atherosclerotic and restenotic lesions. Accordingly, they show a high degree of plasticity and are able to shift from a differentiated, contractile phenotype to a less differentiated, synthetic phenotype, and then back again. This modulation occurs as a response to vascular injury and includes a prominent structural reorganization with loss of myofilaments and formation of an extensive endoplasmic reticulum and a large Golgi complex. At the same time, the expression of cytoskeletal proteins and other gene products is altered. As a result, the cells lose their contractility and become able to migrate from the media to the intima, proliferate, and secrete extracellular matrix components, thereby contributing to the formation of intimal thickenings. The mechanisms behind this change in morphology and function of the smooth muscle cells are still incompletely understood. A crucial role has been ascribed to basement membrane proteins such as laminin and collagen type IV and adhesive proteins such as fibronectin. A significant role is also played by mitogenic proteins such as platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF). An improved knowledge of the regulation of smooth muscle differentiated properties represents an important part in the search for new methods of prevention and treatment of vascular disease.

Satellite cell depletion prevents fiber hypertrophy in skeletal muscle.

Science.gov (United States)

Egner, Ingrid M; Bruusgaard, Jo C; Gundersen, Kristian

2016-08-15

The largest mammalian cells are the muscle fibers, and they have multiple nuclei to support their large cytoplasmic volumes. During hypertrophic growth, new myonuclei are recruited from satellite stem cells into the fiber syncytia, but it was recently suggested that such recruitment is not obligatory: overload hypertrophy after synergist ablation of the plantaris muscle appeared normal in transgenic mice in which most of the satellite cells were abolished. When we essentially repeated these experiments analyzing the muscles by immunohistochemistry and in vivo and ex vivo imaging, we found that overload hypertrophy was prevented in the satellite cell-deficient mice, in both the plantaris and the extensor digitorum longus muscles. We attribute the previous findings to a reliance on muscle mass as a proxy for fiber hypertrophy, and to the inclusion of a significant number of regenerating fibers in the analysis. We discuss that there is currently no model in which functional, sustainable hypertrophy has been unequivocally demonstrated in the absence of satellite cells; an exception is re-growth, which can occur using previously recruited myonuclei without addition of new myonuclei. © 2016. Published by The Company of Biologists Ltd.

Muscle satellite cells are functionally impaired in myasthenia gravis: consequences on muscle regeneration.

Science.gov (United States)

Attia, Mohamed; Maurer, Marie; Robinet, Marieke; Le Grand, Fabien; Fadel, Elie; Le Panse, Rozen; Butler-Browne, Gillian; Berrih-Aknin, Sonia

2017-12-01

Myasthenia gravis (MG) is a neuromuscular disease caused in most cases by anti-acetyl-choline receptor (AChR) autoantibodies that impair neuromuscular signal transmission and affect skeletal muscle homeostasis. Myogenesis is carried out by muscle stem cells called satellite cells (SCs). However, myogenesis in MG had never been explored. The aim of this study was to characterise the functional properties of myasthenic SCs as well as their abilities in muscle regeneration. SCs were isolated from muscle biopsies of MG patients and age-matched controls. We first showed that the number of Pax7+ SCs was increased in muscle sections from MG and its experimental autoimmune myasthenia gravis (EAMG) mouse model. Myoblasts isolated from MG muscles proliferate and differentiate more actively than myoblasts from control muscles. MyoD and MyoG were expressed at a higher level in MG myoblasts as well as in MG muscle biopsies compared to controls. We found that treatment of control myoblasts with MG sera or monoclonal anti-AChR antibodies increased the differentiation and MyoG mRNA expression compared to control sera. To investigate the functional ability of SCs from MG muscle to regenerate, we induced muscle regeneration using acute cardiotoxin injury in the EAMG mouse model. We observed a delay in maturation evidenced by a decrease in fibre size and MyoG mRNA expression as well as an increase in fibre number and embryonic myosin heavy-chain mRNA expression. These findings demonstrate for the first time the altered function of SCs from MG compared to control muscles. These alterations could be due to the anti-AChR antibodies via the modulation of myogenic markers resulting in muscle regeneration impairment. In conclusion, the autoimmune attack in MG appears to have unsuspected pathogenic effects on SCs and muscle regeneration, with potential consequences on myogenic signalling pathways, and subsequently on clinical outcome, especially in the case of muscle stress.

Cell fate determination in zebrafish embryonic and adult muscle development

NARCIS (Netherlands)

Tee, J.M.

2010-01-01

We are interested in how the genetic basis of muscle precursor cells determines the outcome of the muscle cell fate, and thus leading to disruption in muscle formation and maintenance. We utilized the zebrafish carrying mutations in both Axin1 and Apc1, resulting in overactivation of the

Influence of muscle fiber type composition on early fat accumulation under high-fat diet challenge.

Science.gov (United States)

Hua, Ning; Takahashi, Hirokazu; Yee, Grace M; Kitajima, Yoichiro; Katagiri, Sayaka; Kojima, Motoyasu; Anzai, Keizo; Eguchi, Yuichiro; Hamilton, James A

2017-01-01

To investigate whether differences in muscle fiber types affect early-stage fat accumulation, under high fat diet challenge in mice. Twelve healthy male C57BL/6 mice experienced with short-term (6 weeks) diet treatment for the evaluation of early pattern changes in muscular fat. The mice were randomly divided into two groups: high fat diet (n = 8) and normal control diet (n = 4). Extra- and intra-myocellular lipid (EMCL and IMCL) in lumbar muscles (type I fiber predominant) and tibialis anterior (TA) muscle (type II fiber predominant) were determined using magnetic resonance spectroscopy (MRS). Correlation of EMCL, IMCL and their ratio between TA and lumbar muscles was evaluated. EMCL increased greatly in both muscle types after high fat diet. IMCL in TA and lumbar muscles increased to a much lower extent, with a slightly greater increase in TA muscles. EMCLs in the 2 muscles were positively correlated (r = 0.84, p = 0.01), but IMCLs showed a negative relationship (r = -0.84, p = 0.01). In lumbar muscles, high fat diet significantly decreased type I fiber while it increased type II fiber (all p≤0.001). In TA muscle, there was no significant fiber type shifting (p>0.05). Under short-time high fat diet challenge, lipid tends to initially accumulate extra-cellularly. In addition, compared to type II dominant muscle, Type I dominant muscle was less susceptible to IMCL accumulation but more to fiber type shifting. These phenomena might reflect compensative responses of skeletal muscle to dietary lipid overload in order to regulate metabolic homeostasis.

Andrographolide attenuates skeletal muscle dystrophy in mdx mice and increases efficiency of cell therapy by reducing fibrosis.

Science.gov (United States)

Cabrera, Daniel; Gutiérrez, Jaime; Cabello-Verrugio, Claudio; Morales, Maria Gabriela; Mezzano, Sergio; Fadic, Ricardo; Casar, Juan Carlos; Hancke, Juan L; Brandan, Enrique

2014-01-01

Duchenne muscular dystrophy (DMD) is characterized by the absence of the cytoskeletal protein dystrophin, muscle wasting, increased transforming growth factor type beta (TGF-β) signaling, and fibrosis. At the present time, the only clinically validated treatments for DMD are glucocorticoids. These drugs prolong muscle strength and ambulation of patients for a short term only and have severe adverse effects. Andrographolide, a bicyclic diterpenoid lactone, has traditionally been used for the treatment of colds, fever, laryngitis, and other infections with no or minimal side effects. We determined whether andrographolide treatment of mdx mice, an animal model for DMD, affects muscle damage, physiology, fibrosis, and efficiency of cell therapy. mdx mice were treated with andrographolide for three months and skeletal muscle histology, creatine kinase activity, and permeability of muscle fibers were evaluated. Fibrosis and TGF-β signaling were evaluated by indirect immunofluorescence and Western blot analyses. Muscle strength was determined in isolated skeletal muscles and by a running test. Efficiency of cell therapy was determined by grafting isolated skeletal muscle satellite cells onto the tibialis anterior of mdx mice. mdx mice treated with andrographolide exhibited less severe muscular dystrophy than untreated dystrophic mice. They performed better in an exercise endurance test and had improved muscle strength in isolated muscles, reduced skeletal muscle impairment, diminished fibrosis and a significant reduction in TGF-β signaling. Moreover, andrographolide treatment of mdx mice improved grafting efficiency upon intramuscular injection of dystrophin-positive satellite cells. These results suggest that andrographolide could be used to improve quality of life in individuals with DMD.

Skeletal muscle to pancreatic β-cell cross-talk

DEFF Research Database (Denmark)

Christensen, Camilla S; P. Christensen, Dan; Lundh, Morten

2015-01-01

CONTEXT: Mechanisms explaining exercise-induced β-cell health are unknown. OBJECTIVE: To define the role of muscle contraction and acute exercise-derived soluble humoral mediators on β-cell health. DESIGN: In vitro models. SETTING: University. PARTICIPANTS: Healthy subjects. INTERVENTION...... insulin secretion in the absence of IL-1β+IFN-γ. CONCLUSIONS: Unidentified circulating humoral mediators released during exercise prevent proinflammatory cytokine-induced β-cell apoptosis. Muscle-derived mediators released during exercise suppress β-cell insulin secretion. Furthermore, muscle-derived IL-6...

The quasi-parallel lives of satellite cells and atrophying muscle

Directory of Open Access Journals (Sweden)

Stefano eBiressi

2015-07-01

Full Text Available Skeletal muscle atrophy or wasting accompanies various chronic illnesses and the aging process, thereby reducing muscle function. One of the most important components contributing to effective muscle repair in postnatal organisms, the satellite cells, have recently become the focus of several studies examining factors participating in the atrophic process. We critically examine here the experimental evidence linking satellite cell function with muscle loss in connection with various diseases as well as aging, and in the subsequent recovery process. Several recent reports have investigated the changes in satellite cells in terms of their differentiation and proliferative capacity in response to various atrophic stimuli. In this regard, we review the molecular changes within satellite cells that contribute to their dysfunctional status in atrophy, with the intention of shedding light on novel potential pharmacological targets to counteract the loss of muscle mass.

Functional Modeling of the Shift in Cellular Calcium Dynamics at the Onset of Synchronization in Smooth Muscle Cells

DEFF Research Database (Denmark)

Postnov, D E; Brings Jacobsen, J C; von Holstein-Rathlou, Niels-Henrik

2011-01-01

In the present paper we address the nature of synchronization properties found in populations of mesenteric artery smooth muscle cells. We present a minimal model of the onset of synchronization in the individual smooth muscle cell that is manifested as a transition from calcium waves to whole......-cell calcium oscillations. We discuss how different types of ion currents may influence both amplitude and frequency in the regime of whole-cell oscillations. The model may also explain the occurrence of mixed-mode oscillations and chaotic oscillations frequently observed in the experimental system....

The skeletal muscle satellite cell response to a single bout of resistance-type exercise is delayed with aging in men

NARCIS (Netherlands)

Snijders, T.; Verdijk, L.B.; Smeets, J.S.J.; McKay, B.R.; Senden, J.M.G.; Hartgens, F.; Parise, G.; Greenhaff, P.; van Loon, L.J.C.

2014-01-01

Skeletal muscle satellite cells (SCs) have been shown to be instrumental in the muscle adaptive response to exercise. The present study determines age-related differences in SC content and activation status following a single bout of exercise. Ten young (22 +/- 1 years) and 10 elderly (73 +/- 1

Differential requirement for utrophin in the induced pluripotent stem cell correction of muscle versus fat in muscular dystrophy mice.

Directory of Open Access Journals (Sweden)

Amanda J Beck

Full Text Available Duchenne muscular dystrophy (DMD is an incurable degenerative muscle disorder. We injected WT mouse induced pluripotent stem cells (iPSCs into mdx and mdx∶utrophin mutant blastocysts, which are predisposed to develop DMD with an increasing degree of severity (mdx <<< mdx∶utrophin. In mdx chimeras, iPSC-dystrophin was supplied to the muscle sarcolemma to effect corrections at morphological and functional levels. Dystrobrevin was observed in dystrophin-positive and, at a lesser extent, utrophin-positive areas. In the mdx∶utrophin mutant chimeras, although iPSC-dystrophin was also supplied to the muscle sarcolemma, mice still displayed poor skeletal muscle histopathology, and negligible levels of dystrobrevin in dystrophin- and utrophin-negative areas. Not only dystrophin-expressing tissues are affected by iPSCs. Mdx and mdx∶utrophin mice have reduced fat/body weight ratio, but iPSC injection normalized this parameter in both mdx and mdx∶utrophin chimeras, despite the fact that utrophin was compromised in the mdx∶utrophin chimeric fat. The results suggest that the presence of utrophin is required for the iPSC-corrections in skeletal muscle. Furthermore, the results highlight a potential (utrophin-independent non-cell autonomous role for iPSC-dystrophin in the corrections of non-muscle tissue like fat, which is intimately related to the muscle.

A role of pancreatic stellate cells in islet fibrosis and β-cell dysfunction in type 2 diabetes mellitus

International Nuclear Information System (INIS)

Lee, Esder; Ryu, Gyeong Ryul; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

2017-01-01

Objectives: To investigate whether the activation of pancreatic stellate cells (PSCs) leads to pancreatic β-cell dysfunction in type 2 diabetes mellitus (T2DM). Methods: The pancreases of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of T2DM, and patient with T2DM were analyzed. And the in vitro and in vivo effects of pirfenidone, an antifibrotic agent, on PSC activation, islet fibrosis, and β-cells were studied. Results: The extent of islet fibrosis and the percentage of activated PSCs, positive for α-smooth muscle actin, in the islets were significantly greater in OLETF rats compared with non-diabetic rats. Also, the extent of islet fibrosis in patients with T2DM was slightly greater compared with age- and BMI-matched non-diabetic patients. In rat PSCs cultured with high glucose for 72 h, pirfenidone produced decreases in cell proliferation, release of collagen, and the expression of fibronectin and connective tissue growth factor. Treatment of OLETF rats with pirfenidone for 16 weeks decreased the activation of PSCs and the extent of islet fibrosis, but did not enhance glucose tolerance, pancreatic insulin content, or β-cell mass. Conclusions: Activated PSCs in islets might lead to islet fibrosis in T2DM. However, PSC activation itself might not contribute significantly to progressive β-cell failure in T2DM. - Highlights: • Islet fibrosis developed progressively in OLETF rats, a model of type 2 diabetes. • PSCs in the islets became activated in OLETF rats. • Islet fibrosis was increased in patients with type 2 diabetes. • Pirfenidone attenuated the activation of PSCs and islet fibrosis in OLETF rats. • Pirfenidonet had no effects on glucose tolerance or on β-cells in OLETF rats.

Chinese Herbal Medicine Treatment Improves the Overall Survival Rate of Individuals with Hypertension among Type 2 Diabetes Patients and Modulates In Vitro Smooth Muscle Cell Contractility

Science.gov (United States)

Yeh, Yi-Chun; Cheng, Chi-Fung; Shiao, Yi-Tzone; Wang, Chang-Bi; Chien, Wen-Kuei; Chen, Jin-Hua; Liu, Xiang; Tsang, Hsinyi; Lin, Ting-Hsu; Liao, Chiu-Chu; Huang, Shao-Mei; Li, Ju-Pi; Lin, Cheng-Wen; Pang, Hao-Yu; Lin, Jaung-Geng; Lan, Yu-Ching; Liu, Yu-Huei; Chen, Shih-Yin; Tsai, Fuu-Jen; Liang, Wen-Miin

2015-01-01

Type 2 diabetes (T2D) is a chronic, multifactorial, and metabolic disorder accounting for 90% diabetes cases worldwide. Among them, almost half of T2D have hypertension, which is responsible for cardiovascular disease, morbidity, and mortality in these patients. The Chinese herbal medicine (CHM) prescription patterns of hypertension individuals among T2D patients have yet to be characterized. This study, therefore, aimed to determine their prescription patterns and evaluate the CHM effect. A cohort of one million randomly sampled cases from the National Health Insurance Research Database (NHIRD) was used to investigate the overall survival rate of CHM users, and prescription patterns. After matching CHM and non-CHM users for age, gender and date of diagnosis of hypertension, 980 subjects for each group were selected. The CHM users were characterized with slightly longer duration time from diabetes to hypertension, and more cases for hyperlipidaemia. The cumulative survival probabilities were higher in CHM users than in non-CHM users. Among these top 12 herbs, Liu-Wei-Di-Huang-Wan, Jia-Wei-Xiao-Yao-San, Dan-Shen, and Ge-Gen were the most common herbs and inhibited in vitro smooth muscle cell contractility. Our study also provides a CHM comprehensive list that may be useful in future investigation of the safety and efficacy for individuals with hypertension among type 2 diabetes patients. PMID:26699542

Activation of Pax7-positive cells in a non-contractile tissue contributes to regeneration of myogenic tissues in the electric fish S. macrurus.

Directory of Open Access Journals (Sweden)

Christopher M Weber

Full Text Available The ability to regenerate tissues is shared across many metazoan taxa, yet the type and extent to which multiple cellular mechanisms come into play can differ across species. For example, urodele amphibians can completely regenerate all lost tissues, including skeletal muscles after limb amputation. This remarkable ability of urodeles to restore entire limbs has been largely linked to a dedifferentiation-dependent mechanism of regeneration. However, whether cell dedifferentiation is the fundamental factor that triggers a robust regeneration capacity, and whether the loss or inhibition of this process explains the limited regeneration potential in other vertebrates is not known. Here, we studied the cellular mechanisms underlying the repetitive regeneration of myogenic tissues in the electric fish S. macrurus. Our in vivo microinjection studies of high molecular weight cell lineage tracers into single identified adult myogenic cells (muscle or noncontractile muscle-derived electrocytes revealed no fragmentation or cellularization proximal to the amputation plane. In contrast, ultrastructural and immunolabeling studies verified the presence of myogenic stem cells that express the satellite cell marker Pax7 in mature muscle fibers and electrocytes of S. macrurus. These data provide the first example of Pax-7 positive muscle stem cells localized within a non-contractile electrogenic tissue. Moreover, upon amputation, Pax-7 positive cells underwent a robust replication and were detected exclusively in regions that give rise to myogenic cells and dorsal spinal cord components revealing a regeneration process in S. macrurus that is dependent on the activation of myogenic stem cells for the renewal of both skeletal muscle and the muscle-derived electric organ. These data are consistent with the emergent concept in vertebrate regeneration that different tissues provide a distinct progenitor cell population to the regeneration blastema, and these

Effects of acute exercise on gene expression in exercising and non-exercising human skeletal muscle

NARCIS (Netherlands)

Catoire, Milene; Mensink, Marco; Boekschoten, Mark; Hangelbroek, Roland; Muller, Michael; Schrauwen, Patricht; Kersten, Sander

2012-01-01

Background: Exercising is know to have an effect on exercising skeletal muscle, but unkown is the effect on non-exercising skeletal muscle. Gene expression changes in the non-exercising skeletal muscle would point to a signalling role of skeletal muscle

Genome-wide identification and characterization of long non-coding RNAs in developmental skeletal muscle of fetal goat.

Science.gov (United States)

Zhan, Siyuan; Dong, Yao; Zhao, Wei; Guo, Jiazhong; Zhong, Tao; Wang, Linjie; Li, Li; Zhang, Hongping

2016-08-22

Long non-coding RNAs (lncRNAs) have been studied extensively over the past few years. Large numbers of lncRNAs have been identified in mouse, rat, and human, and some of them have been shown to play important roles in muscle development and myogenesis. However, there are few reports on the characterization of lncRNAs covering all the development stages of skeletal muscle in livestock. RNA libraries constructed from developing longissimus dorsi muscle of fetal (45, 60, and 105 days of gestation) and postnatal (3 days after birth) goat (Capra hircus) were sequenced. A total of 1,034,049,894 clean reads were generated. Among them, 3981 lncRNA transcripts corresponding to 2739 lncRNA genes were identified, including 3515 intergenic lncRNAs and 466 anti-sense lncRNAs. Notably, in pairwise comparisons between the libraries of skeletal muscle at the different development stages, a total of 577 transcripts were differentially expressed (P development-related processes, indicating they may be in cis-regulatory relationships. Additionally, Pearson's correlation coefficients of co-expression levels suggested 1737 lncRNAs and 19,422 mRNAs were possibly in trans-regulatory relationships (r > 0.95 or r development-related biological processes such as muscle system processes, regulation of cell growth, muscle cell development, regulation of transcription, and embryonic morphogenesis. This study provides a catalog of goat muscle-related lncRNAs, and will contribute to a fuller understanding of the molecular mechanism underpinning muscle development in mammals.

Skeletal muscle aging: stem cell function and tissue homeostasis

OpenAIRE

Victor, Pedro Sousa

2012-01-01

Muscle aging, in particular, is characterized by the reduction of tissue mass and function, which are particularly prominent in geriatric individuals undergoing sarcopenia. The age-associated muscle wasting is also associated with a decline in regenerative ability and a reduction in resident muscle stem cell (satellite cell) number and function. Although sarcopenia is one of the major contributors to the general loss of physiological function, the mechanisms involved in age-related loss of mu...

Isolation, culture and biological characteristics of multipotent porcine skeletal muscle satellite cells.

Science.gov (United States)

Yang, Jinjuan; Liu, Hao; Wang, Kunfu; Li, Lu; Yuan, Hongyi; Liu, Xueting; Liu, Yingjie; Guan, Weijun

2017-12-01

Skeletal muscle has a huge regenerative potential for postnatal muscle growth and repair, which mainly depends on a kind of muscle progenitor cell population, called satellite cell. Nowadays, the majority of satellite cells were obtained from human, mouse, rat and other animals but rarely from pig. In this article, the porcine skeletal muscle satellite cells were isolated and cultured in vitro. The expression of surface markers of satellite cells was detected by immunofluorescence and RT-PCR assays. The differentiation capacity was assessed by inducing satellite cells into adipocytes, myoblasts and osteoblasts. The results showed that satellite cells isolated from porcine tibialis anterior were subcultured up to 12 passages and were positive for Pax7, Myod, c-Met, desmin, PCNA and NANOG but were negative for Myogenin. Satellite cells were also induced to differentiate into adipocytes, osteoblasts and myoblasts, respectively. These findings indicated that porcine satellite cells possess similar biological characteristics of stem cells, which may provide theoretical basis and experimental evidence for potential therapeutic application in the treatment of dystrophic muscle and other muscle injuries.

Response of turkey muscle satellite cells to thermal challenge. I. transcriptome effects in proliferating cells.

Science.gov (United States)

Reed, Kent M; Mendoza, Kristelle M; Abrahante, Juan E; Barnes, Natalie E; Velleman, Sandra G; Strasburg, Gale M

2017-05-06

Climate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure. Satellite cells isolated from the pectoralis major muscle of 7-weeks-old male turkeys from two breeding lines (16 weeks body weight-selected and it's randombred control) were proliferated in culture at 33 °C, 38 °C or 43 °C for 72 h. Total RNA was isolated and 12 libraries subjected to RNAseq analysis. Statistically significant differences in gene expression were observed among treatments and between turkey lines with a greater number of genes altered by cold treatment than by hot and fewer differences observed between lines than between temperatures. Pathway analysis found that cold treatment resulted in an overrepresentation of genes involved in cell signaling/signal transduction and cell communication/cell signaling as compared to control (38 °C). Heat-treated muscle satellite cells showed greater tendency towards expression of genes related to muscle system development and differentiation. This study demonstrates significant transcriptome effects on turkey skeletal muscle satellite cells exposed to thermal challenge. Additional effects on gene expression could be attributed to genetic selection for 16 weeks body weight (muscle mass). New targets are identified for further research on the differential control of satellite cell proliferation in poultry.

MASTR directs MyoD-dependent satellite cell differentiation during skeletal muscle regeneration

OpenAIRE

Mokalled, Mayssa H.; Johnson, Aaron N.; Creemers, Esther E.; Olson, Eric N.

2012-01-01

Muscle repair is regulated by satellite cells, adult skeletal muscle stem cells that control muscle regeneration by proliferating and fusing with injured myofibers. MyoD is required for muscle regeneration; however, the mechanisms regulating MyoD expression in satellite cells are unclear. In this study, Olson and colleagues have demonstrated that deletion of MASTR and MRTF-A, two members of the Myocardin family of transcription factors, leads to skeletal muscle regeneration defects and down-r...

Skeletal muscle regeneration is modulated by inflammation

Directory of Open Access Journals (Sweden)

Wenjun Yang

2018-04-01

Full Text Available Skeletal muscle regeneration is a complex process orchestrated by multiple steps. Recent findings indicate that inflammatory responses could play central roles in bridging initial muscle injury responses and timely muscle injury reparation. The various types of immune cells and cytokines have crucial roles in muscle regeneration process. In this review, we briefly summarise the functions of acute inflammation in muscle regeneration. The translational potential of this article: Immune system is closely relevant to the muscle regeneration. Understanding the mechanisms of inflammation in muscle regeneration is therefore critical for the development of effective regenerative, and therapeutic strategies in muscular disorders. This review provides information for muscle regeneration research regarding the effects of inflammation on muscle regeneration. Keywords: Chronic muscle disorders, Cytokines, Immune cells, Inflammation, Muscle regeneration, Muscle stem cells

Augmented vascular smooth muscle cell stiffness and adhesion when hypertension is superimposed on aging.

Science.gov (United States)

Sehgel, Nancy L; Sun, Zhe; Hong, Zhongkui; Hunter, William C; Hill, Michael A; Vatner, Dorothy E; Vatner, Stephen F; Meininger, Gerald A

2015-02-01

Hypertension and aging are both recognized to increase aortic stiffness, but their interactions are not completely understood. Most previous studies have attributed increased aortic stiffness to changes in extracellular matrix proteins that alter the mechanical properties of the vascular wall. Alternatively, we hypothesized that a significant component of increased vascular stiffness in hypertension is due to changes in the mechanical and adhesive properties of vascular smooth muscle cells, and that aging would augment the contribution from vascular smooth muscle cells when compared with the extracellular matrix. Accordingly, we studied aortic stiffness in young (16-week-old) and old (64-week-old) spontaneously hypertensive rats and Wistar-Kyoto wild-type controls. Systolic and pulse pressures were significantly increased in young spontaneously hypertensive rats when compared with young Wistar-Kyoto rats, and these continued to rise in old spontaneously hypertensive rats when compared with age-matched controls. Excised aortic ring segments exhibited significantly greater elastic moduli in both young and old spontaneously hypertensive rats versus Wistar-Kyoto rats. were isolated from the thoracic aorta, and stiffness and adhesion to fibronectin were measured by atomic force microscopy. Hypertension increased both vascular smooth muscle cell stiffness and vascular smooth muscle cell adhesion, and these increases were both augmented with aging. By contrast, hypertension did not affect histological measures of aortic collagen and elastin, which were predominantly changed by aging. These findings support the concept that stiffness and adhesive properties of vascular smooth muscle cells are novel mechanisms contributing to the increased aortic stiffness occurring with hypertension superimposed on aging. © 2014 American Heart Association, Inc.

Muscle Stem Cell Therapy for the Treatment of DMD Associated Cardiomyopathy

Science.gov (United States)

2013-10-01

SUBTITLE Muscle Stem Cell Therapy for the Treatment of DMD Associated Cardiomyopathy 5a. CONTRACT NUMBER Subproject 1: Muscle Stem Cell Therapy...various muscle diseases, including Duchenne muscular dystrophy (DMD), develop progressive cardiomyopathy. Cellular cardiomyoplasty, which involves the

Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy

Science.gov (United States)

Fry, Christopher S.; Lee, Jonah D.; Jackson, Janna R.; Kirby, Tyler J.; Stasko, Shawn A.; Liu, Honglu; Dupont-Versteegden, Esther E.; McCarthy, John J.; Peterson, Charlotte A.

2014-01-01

Our aim in the current study was to determine the necessity of satellite cells for long-term muscle growth and maintenance. We utilized a transgenic Pax7-DTA mouse model, allowing for the conditional depletion of > 90% of satellite cells with tamoxifen treatment. Synergist ablation surgery, where removal of synergist muscles places functional overload on the plantaris, was used to stimulate robust hypertrophy. Following 8 wk of overload, satellite cell-depleted muscle demonstrated an accumulation of extracellular matrix (ECM) and fibroblast expansion that resulted in reduced specific force of the plantaris. Although the early growth response was normal, an attenuation of hypertrophy measured by both muscle wet weight and fiber cross-sectional area occurred in satellite cell-depleted muscle. Isolated primary myogenic progenitor cells (MPCs) negatively regulated fibroblast ECM mRNA expression in vitro, suggesting a novel role for activated satellite cells/MPCs in muscle adaptation. These results provide evidence that satellite cells regulate the muscle environment during growth.—Fry, C. S., Lee, J. D., Jackson, J. R., Kirby, T. J., Stasko, S. A., Liu, H., Dupont-Versteegden, E. E., McCarthy, J. J., Peterson, C. A. Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy. PMID:24376025

Satellite Cells CD44 Positive Drive Muscle Regeneration in Osteoarthritis Patients

Science.gov (United States)

Scimeca, Manuel; Bonanno, Elena; Piccirilli, Eleonora; Baldi, Jacopo; Mauriello, Alessandro; Orlandi, Augusto; Tancredi, Virginia; Gasbarra, Elena; Tarantino, Umberto

2015-01-01

Age-related bone diseases, such as osteoarthritis and osteoporosis, are strongly associated with sarcopenia and muscle fiber atrophy. In this study, we analyzed muscle biopsies in order to demonstrate that, in osteoarthritis patients, both osteophytes formation and regenerative properties of muscle stem cells are related to the same factors. In particular, thanks to immunohistochemistry, transmission electron microscopy, and immunogold labeling we investigated the role of BMP-2 in muscle stem cells activity. In patients with osteoarthritis both immunohistochemistry and transmission electron microscopy allowed us to note a higher number of CD44 positive satellite muscle cells forming syncytium. Moreover, the perinuclear and cytoplasmic expression of BMP-2 assessed by in situ molecular characterization of satellite cells syncytia suggest a very strict correlation between BMP-2 expression and muscle regeneration capability. Summing up, the higher BMP-2 expression in osteoarthritic patients could explain the increased bone mineral density as well as decreased muscle atrophy in osteoarthrosic patients. In conclusion, our results suggest that the control of physiological BMP-2 balance between bone and muscle tissues may be considered as a potential pharmacological target in bone-muscle related pathology. PMID:26101529

Satellite Cells CD44 Positive Drive Muscle Regeneration in Osteoarthritis Patients

Directory of Open Access Journals (Sweden)

Manuel Scimeca

2015-01-01

Full Text Available Age-related bone diseases, such as osteoarthritis and osteoporosis, are strongly associated with sarcopenia and muscle fiber atrophy. In this study, we analyzed muscle biopsies in order to demonstrate that, in osteoarthritis patients, both osteophytes formation and regenerative properties of muscle stem cells are related to the same factors. In particular, thanks to immunohistochemistry, transmission electron microscopy, and immunogold labeling we investigated the role of BMP-2 in muscle stem cells activity. In patients with osteoarthritis both immunohistochemistry and transmission electron microscopy allowed us to note a higher number of CD44 positive satellite muscle cells forming syncytium. Moreover, the perinuclear and cytoplasmic expression of BMP-2 assessed by in situ molecular characterization of satellite cells syncytia suggest a very strict correlation between BMP-2 expression and muscle regeneration capability. Summing up, the higher BMP-2 expression in osteoarthritic patients could explain the increased bone mineral density as well as decreased muscle atrophy in osteoarthrosic patients. In conclusion, our results suggest that the control of physiological BMP-2 balance between bone and muscle tissues may be considered as a potential pharmacological target in bone-muscle related pathology.

Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

Science.gov (United States)

Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

2015-01-01

The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

Distribution of myogenic progenitor cells and myonuclei is altered in women with vs. those without chronically painful trapezius muscle

DEFF Research Database (Denmark)

Mackey, Abigail; Andersen, Lars L; Frandsen, Ulrik

2010-01-01

It is hypothesized that repeated recruitment of low-threshold motor units is an underlying cause of chronic pain in trapezius myalgia. This study investigated the distribution of satellite cells (SCs), myonuclei, and macrophages in muscle biopsies from the trapezius muscle of 42 women performing...... repetitive manual work, diagnosed with trapezius myalgia (MYA; 44 ± 8 yr; mean ± SD) and 20 matched healthy controls (CON; 45 ± 9 yr). Our hypothesis was that muscle of MYA, in particular type I fibers, would demonstrate higher numbers of SCs, myonuclei, and macrophages compared with CON. SCs were identified...... was not in line with our hypothesis and suggests that the elevated SC content of MYA was not due to heightened inflammatory cell contents, but rather to provide new myonuclei. The findings of greater numbers of SCs in type I fibers of muscle subjected to repeated low-intensity work support our hypothesis...

Muscle fibre type composition and body composition in hammer throwers.

Science.gov (United States)

Terzis, Gerasimos; Spengos, Konstantinos; Kavouras, Stavros; Manta, Panagiota; Georgiadis, Giorgos

2010-01-01

Aim of the present study was to describe the muscle fibre type composition and body composition of well-trained hammer throwers. Six experienced hammer throwers underwent the following measurements: one repetition maximum in squat, snatch, and clean, standing broad jump, backward overhead shot throw and the hammer throw. Dual x-ray absorptiometry was used for body composition analysis. Fibre type composition and cross sectional area was determined in muscle biopsy samples of the right vastus lateralis. Eight physical education students served as a control group. One repetition maximum in squat, snatch and clean for the hammer throwers was 245 ± 21, 132 ± 13 and 165 ± 12kg, respectively. Lean body mass was higher in hammer throwers (85.9 ± 3. 9kg vs. 62.7 ± 5.1kg (p hammer throwers and 51 ± 8% in the control group (p Hammer throwers had significantly larger type IIA fibres (7703 ± 1171 vs. 5676 ± 1270μm(2), p Hammer throwing performance correlated significantly with lean body mass (r = 0.81, p hammer throwers have larger lean body mass and larger muscular areas occupied by type II fibres, compared with relatively untrained subjects. Moreover, it seems that the enlarged muscle mass of the hammer throwers contributes significantly to the hammer throwing performance. Key pointsWell-trained hammer throwers had increased lean body mass, higher type IIA muscle fibres cross sectional areas, as well as higher bone mineral density, compared to controls.Increased lean body mass was closely related with hammer throwing performance.The relative high percentage of type IIX muscle fibres in vastus lateralis in hammer throwers warrants further investigation.

Muscles and their role in episodic tension-type headache: implications for treatment.

Science.gov (United States)

Bendtsen, L; Ashina, S; Moore, A; Steiner, T J

2016-02-01

Tension-type headache (TTH) imposes a heavy burden on the global population but remains incompletely understood and poorly managed. Here, we review current knowledge of peripheral factors involved in the mechanism of TTH and make recommendations for the treatment of episodic TTH based on these. Peripheral activation or sensitization of myofascial nociceptors is most probably involved in the development of muscle pain and the acute episode of TTH. Repetitive episodes of muscle pain may sensitize the central nervous system resulting in progression of TTH to the chronic form. Thus, muscular factors may be responsible not only for the acute headache episode but also for chronification of the disorder. Simple analgesics and non-steroidal anti-inflammatory drugs are the mainstays of management of individual headache episodes. Ibuprofen 400 mg and aspirin 1000 mg are recommended as drugs of first choice based on treatment effect, safety profile and costs. Non-pharmacological therapies include electromyographic biofeedback, physiotherapy and muscle relaxation therapy. Future studies should aim to identify the triggers of peripheral nociception and how to avoid peripheral and central sensitization. There is a need for more effective, faster acting drugs for acute TTH. Muscular factors play an important role in episodic TTH. Ibuprofen 400 mg and aspirin 1000 mg are recommended as drugs of first choice. © 2015 European Pain Federation - EFIC®

Energetic aspects of skeletal muscle contraction: implications of fiber types.

Science.gov (United States)

Rall, J A

1985-01-01

In this chapter fundamental energetic properties of skeletal muscles as elucidated from isolated muscle preparations are described. Implications of these intrinsic properties for the energetic characterization of different fiber types and for the understanding of locomotion have been considered. Emphasis was placed on the myriad of physical and chemical techniques that can be employed to understand muscle energetics and on the interrelationship of results from different techniques. The anaerobic initial processes which liberate energy during contraction and relaxation are discussed in detail. The high-energy phosphate (approximately P) utilized during contraction and relaxation can be distributed between actomyosin ATPase or cross-bridge cycling (70%) and the Ca2+ ATPase of the sacroplasmic reticulum (30%). Muscle shortening increases the rate of approximately P hydrolysis, and stretching a muscle during contraction suppresses the rate of approximately P hydrolysis. The economy of an isometric contraction is defined as the ratio of isometric mechanical response to energetic cost and is shown to be a fundamental intrinsic parameter describing muscle energetics. Economy of contraction varies across the animal kingdom by over three orders of magnitude and is different in different mammalian fiber types. In mammalian skeletal muscles differences in economy of contraction can be attributed mainly to differences in the specific actomyosin and Ca2+ ATPase of muscles. Furthermore, there is an inverse relationship between economy of contraction and maximum velocity of muscle shortening (Vmax) and maximum power output. This is a fundamental relationship. Muscles cannot be economical at developing and maintaining force and also exhibit rapid shortening. Interestingly, there appears to be a subtle system of unknown nature that modulates the Vmax and economy of contraction. Efficiency of a work-producing contraction is defined and contrasted to the economy of contraction

Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes

Science.gov (United States)

Schoneich, Christian; Dremina, Elena; Galeva, Nadezhda; Sharov, Victor

2014-01-01

Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cell but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad. PMID:24129924

Purified Human Skeletal Muscle-Derived Stem Cells Enhance the Repair and Regeneration in the Damaged Urethra.

Science.gov (United States)

Nakajima, Nobuyuki; Tamaki, Tetsuro; Hirata, Maki; Soeda, Shuichi; Nitta, Masahiro; Hoshi, Akio; Terachi, Toshiro

2017-10-01

Postoperative damage of the urethral rhabdosphincter and nerve-vascular networks is a major complication of radical prostatectomy and generally causes incontinence and/or erectile dysfunction. The human skeletal muscle-derived stem cells, which have a synchronized reconstitution capacity of muscle-nerve-blood vessel units, were applied to this damage. Cells were enzymatically extracted from the human skeletal muscle, sorted using flow cytometry as CD34/45 (Sk-34) and CD29/34/45 (Sk-DN/29) fractions, and separately cultured/expanded in appropriate conditions within 2 weeks. Urethral damage was induced by manually removing one third of the wall of the muscle layer in nude rats. A mixture of expanded Sk-34 and Sk-DN/29 cells was applied on the damaged portion for the cell transplantation (CT) group. The same amount of media was used for the non-CT (NT) group. Urethral pressure profile was evaluated via electrical stimulation to assess functional recovery. Cell engraftments and differentiations were detected using immunohistochemistry and immunoelectron microscopy. Expression of angiogenic cytokines was also analyzed using reverse transcriptase-polymerase chain reaction and protein array. At 6 weeks after transplantation, the CT group showed a significantly higher functional recovery than the NT group (70.2% and 39.1%, respectively; P cells differentiated into skeletal muscle fibers, nerve-related Schwann cells, perineuriums, and vascular pericytes. Active paracrine angiogenic cytokines in the mixed cells were also detected with enhanced vascular formation in vivo. The transplantation of Sk-34 and Sk-DN/29 cells is potentially useful for the reconstitution of postoperative damage of the urethral rhabdosphincter and nerve-vascular networks.

Eccentric exercise training as a countermeasure to non-weight-bearing soleus muscle atrophy

Science.gov (United States)

Kirby, Christopher R.; Ryan, Mirelle J.; Booth, Frank W.

1992-01-01

This investigation tested whether eccentric resistance training could prevent soleus muscle atrophy during non-weight bearing. Adult female rats were randomly assigned to either weight bearing +/- intramuscular electrodes or non-weight bearing +/- intramuscular electrodes groups. Electrically stimulated maximal eccentric contractions were performed on anesthetized animals at 48-h intervals during the 10-day experiment. Non-weight bearing significantly reduced soleus muscle wet weight (28-31 percent) and noncollagenous protein content (30-31 percent) compared with controls. Eccentric exercise training during non-weight bearing attenuated but did not prevent the loss of soleus muscle wet weight and noncollagenous protein by 77 and 44 percent, respectively. The potential of eccentric exercise training as an effective and highly efficient counter-measure to non-weight-bearing atrophy is demonstrated in the 44 percent attenuation of soleus muscle noncollagenous protein loss by eccentric exercise during only 0.035 percent of the total non-weight-bearing time period.

Enhanced contractile force generation by artificial skeletal muscle tissues using IGF-I gene-engineered myoblast cells.

Science.gov (United States)

Sato, Masanori; Ito, Akira; Kawabe, Yoshinori; Nagamori, Eiji; Kamihira, Masamichi

2011-09-01

The aim of this study was to investigate whether insulin-like growth factor (IGF)-I gene delivery to myoblast cells promotes the contractile force generated by hydrogel-based tissue-engineered skeletal muscles in vitro. Two retroviral vectors allowing doxycycline (Dox)-inducible expression of the IGF-I gene were transduced into mouse myoblast C2C12 cells to evaluate the effects of IGF-I gene expression on these cells. IGF-I gene expression stimulated the proliferation of C2C12 cells, and a significant increase in the growth rate was observed for IGF-I-transduced C2C12 cells with Dox addition, designated C2C12/IGF (Dox+) cells. Quantitative morphometric analyses showed that the myotubes induced from C2C12/IGF (Dox+) cells had a larger area and a greater width than control myotubes induced from normal C2C12 cells. Artificial skeletal muscle tissues were prepared from the respective cells using hydrogels composed of type I collagen and Matrigel. Western blot analyses revealed that the C2C12/IGF (Dox+) tissue constructs showed activation of a skeletal muscle hypertrophy marker (Akt) and enhanced expression of muscle-specific markers (myogenin, myosin heavy chain and tropomyosin). Moreover, the creatine kinase activity was increased in the C2C12/IGF (Dox+) tissue constructs. The C2C12/IGF (Dox+) tissue constructs contracted in response to electrical pulses, and generated a significantly higher physical force than the control C2C12 tissue constructs. These findings indicate that IGF-I gene transfer has the potential to yield functional skeletal muscle substitutes that are capable of in vivo restoration of the load-bearing function of injured muscle or acting as in vitro electrically-controlled bio-actuators. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Chiral Orientation of Skeletal Muscle Cells Requires Rigid Substrate

Directory of Open Access Journals (Sweden)

Ninghao Zhu

2017-06-01

Full Text Available Reconstitution of tissue morphology with inherent left–right (LR asymmetry is essential for tissue/organ functions. For skeletal muscle, the largest tissue in mammalian organisms, successful myogenesis requires the regulation of the LR asymmetry to form the appropriate muscle alignment. However, the key factor for reproducing the LR asymmetry of skeletal tissues in a controllable, engineering context remains largely unknown. Recent reports indicate that cell chirality may underlie the LR development in tissue morphogenesis. Here, we report that a rigid substrate is required for the chirality of skeletal muscle cells. By using alternating micropatterned cell-adherent and cell-repellent stripes on a rigid substrate, we found that C2C12 skeletal muscle myoblasts exhibited a unidirectional tilted orientation with respect to the stripe boundary. Importantly, such chiral orientation was reduced when soft substrates were used instead. In addition, we demonstrated the key role of actin stress fibers in the formation of the chiral orientation. This study reveals that a rigid substrate is required for the chiral pattern of myoblasts, paving the way for reconstructing damaged muscle tissue with inherent LR asymmetry in the future.

Muscle atrophy reversed by growth factor activation of satellite cells in a mouse muscle atrophy model.

Directory of Open Access Journals (Sweden)

Simon Hauerslev

Full Text Available Muscular dystrophies comprise a large group of inherited disorders that lead to progressive muscle wasting. We wanted to investigate if targeting satellite cells can enhance muscle regeneration and thus increase muscle mass. We treated mice with hepatocyte growth factor and leukemia inhibitory factor under three conditions: normoxia, hypoxia and during myostatin deficiency. We found that hepatocyte growth factor treatment led to activation of the Akt/mTOR/p70S6K protein synthesis pathway, up-regulation of the myognic transcription factors MyoD and myogenin, and subsequently the negative growth control factor, myostatin and atrophy markers MAFbx and MuRF1. Hypoxia-induced atrophy was partially restored by hepatocyte growth factor combined with leukemia inhibitory factor treatment. Dividing satellite cells were three-fold increased in the treatment group compared to control. Finally, we demonstrated that myostatin regulates satellite cell activation and myogenesis in vivo following treatment, consistent with previous findings in vitro. Our results suggest, not only a novel in vivo pharmacological treatment directed specifically at activating the satellite cells, but also a myostatin dependent mechanism that may contribute to the progressive muscle wasting seen in severely affected patients with muscular dystrophy and significant on-going regeneration. This treatment could potentially be applied to many conditions that feature muscle wasting to increase muscle bulk and strength.

Primary defects in lipolysis and insulin action in skeletal muscle cells from type 2 diabetic individuals

DEFF Research Database (Denmark)

Kase, E. T.; Feng, Y. Z.; Badin, P. M.

2015-01-01

A decrease in skeletal muscle lipolysis and hormone sensitive-lipase (HSL) expression has been linked to insulin resistance in obesity. The purpose of this study was to identify potential intrinsic defects in lipid turnover and lipolysis in myotubes established from obese and type 2 diabetic...

Effect of 5 weeks horizontal bed rest on human muscle thickness and architecture of weight bearing and non-weight bearing muscles.

Science.gov (United States)

de Boer, Maarten D; Seynnes, Olivier R; di Prampero, Pietro E; Pisot, Rado; Mekjavić, Igor B; Biolo, Gianni; Narici, Marco V

2008-09-01

The aim of the present study was to investigate the changes in thickness, fascicle length (L (f)) and pennation angle (theta) of the antigravity gastrocnemius medialis (GM) and vastus lateralis (VL) muscles, and the non-antigravity tibialis anterior (TA) and biceps brachii (BB) muscles measured by ultrasonography in ten healthy males (aged 22.3 +/- 2.2 years) in response to 5 weeks of horizontal bed rest (BR). After BR, muscle thickness decreased by 12.2 +/- 8.8% (P antigravity muscles of the lower limbs, the GM deteriorated to a greater extent than the VL is possibly related to the differences in relative load that this muscle normally experiences during daily loading. The dissimilar response in antigravity and non-antigravity muscles to unloading likely reflects differences in loading under normal conditions. The significant structural alterations of the GM and VL muscles highlight the rapid remodelling of muscle architecture occurring with disuse.

MRI manifestations of primary muscle non-Hodgkin lymphoma

International Nuclear Information System (INIS)

Zhou Jianjun; Wang Jianhua; Zeng Mengsu; Ya Fuhua; Zhou Kangrong; Ding Jianguo; Ji Yuan

2009-01-01

Objective: To explore and evaluate MRI in diagnosing primary muscle non-Hodgkin lymphoma. Methods: Six surgically confirmed primary muscle non-Hodgkin lymphoma underwent MR examination including T 1 WI, T 2 WI and T 1 WI enhanced studies. The acquired images date was reviewed and analysed retrospectively in comparison with surgical and pathological results. Results: The locations of 6 cases were cervical part (2), upper extremity (1), lower extremity (3), respectively. All cases involved of more than one anatomical compartment with poorly defined solid masses in 5 cases and well defined in 1 cases, 5 extended to subcutaneous fat and 3 extended along the neurovascular bundle. The mean tumor diameter was 13.9 cm, ranging from 7.3 to 22.5 cm. One was well demarcated and 5 were ill-defined. On T 1 WI, 2 were slightly high signal intensity and 4 were slightly low signal intensity. On T 2 WI, 2 were slightly high signal intensity, 3 were intermediate signal intensity and 1 was high signal intensity. Five were inhomogeneous and 1 was homogeneous. The intrinsic structure such as muscle fiber, tendo, spatium intramuscular were detected on 5 cases. Of the 5 dynamic contrast-enhanced cases, it showed moderate enhancement during arterial phase, 2 were homogeneous and 3 were inhomogeneous. And it showed progressive enhancement during interstitial phase, 3 were homogeneous and 2 were inhomogeneous. Conclusions: Primary muscle lymphoma always originated deep to the fascia showing subcutaneous extension and multiple compartment invasion. Typically from poorly defined solid masses with slightly high in signal intensity on MR T 2 WI and middle degree dynamic delayed contrasted-enhanced in which intrinsic anatomic structure such as muscle fiber, tendo, spatium intramuscular and so on can be discerned, almost all cases involve more than one muscle compartment and some of tumor extend along the neurovascular bundle. (authors)

Quality of life in patients with muscle invasive and non-muscle invasive bladder cancer.

Science.gov (United States)

Singer, S; Ziegler, C; Schwalenberg, T; Hinz, A; Götze, H; Schulte, T

2013-05-01

Compared to the literature on other malignancies, data on quality of life (QoL) in bladder cancer are sparse. This study sought answers to the following questions: In what QoL domains do patients with bladder cancer differ from the general population? Do patients with radical cystectomy differ in QoL compared to those who received conservative treatment? Do patients with neobladder generally have better QoL compared to patients with other diversion methods? At the beginning of inpatient rehabilitation, N = 823 patients with bladder cancer were assessed. Data of a representative community sample (N = 2037) were used for comparison. The questionnaire EORTC QLQ-C30 was used to measure QoL. Multivariate linear regression models were computed to investigate differences between groups. Patients with both non-muscle invasive and muscle invasive bladder cancer reported significantly more problems and worse functioning than the general population. Radiotherapy is associated with clinically relevant more pain, dyspnoea, constipation, appetite loss and decreased social functioning while chemotherapy is associated more with dyspnoea. Cystectomy patients reported more fatigue, appetite loss and decreased role functioning. Male patients ≥70 years with conduit experienced more sleep and emotional problems. These effects of urinary diversion were not observed in women and younger patients. Patients with bladder cancer experience various QoL concerns at the beginning of inpatient rehabilitation. These problems can partly be explained by the type of treatment the patients receive. Type of urinary diversion is relevant for QoL in subgroups of patients.

Increased Stiffness in Aged Skeletal Muscle Impairs Muscle Progenitor Cell Proliferative Activity.

Directory of Open Access Journals (Sweden)

Grégory Lacraz

Full Text Available Skeletal muscle aging is associated with a decreased regenerative potential due to the loss of function of endogenous stem cells or myogenic progenitor cells (MPCs. Aged skeletal muscle is characterized by the deposition of extracellular matrix (ECM, which in turn influences the biomechanical properties of myofibers by increasing their stiffness. Since the stiffness of the MPC microenvironment directly impacts MPC function, we hypothesized that the increase in muscle stiffness that occurs with aging impairs the behavior of MPCs, ultimately leading to a decrease in regenerative potential.We showed that freshly isolated individual myofibers from aged mouse muscles contain fewer MPCs overall than myofibers from adult muscles, with fewer quiescent MPCs and more proliferative and differentiating MPCs. We observed alterations in cultured MPC behavior in aged animals, where the proliferation and differentiation of MPCs were lower and higher, respectively. These alterations were not linked to the intrinsic properties of aged myofibers, as shown by the similar values for the cumulative population-doubling values and fusion indexes. However, atomic force microscopy (AFM indentation experiments revealed a nearly 4-fold increase in the stiffness of the MPC microenvironment. We further showed that the increase in stiffness is associated with alterations to muscle ECM, including the accumulation of collagen, which was correlated with higher hydroxyproline and advanced glycation end-product content. Lastly, we recapitulated the impaired MPC behavior observed in aging using a hydrogel substrate that mimics the stiffness of myofibers.These findings provide novel evidence that the low regenerative potential of aged skeletal muscle is independent of intrinsic MPC properties but is related to the increase in the stiffness of the MPC microenvironment.

Kir2.1 regulates rat smooth muscle cell proliferation, migration, and post-injury carotid neointimal formation

International Nuclear Information System (INIS)

Qiao, Yong; Tang, Chengchun; Wang, Qingjie; Wang, Dong; Yan, Gaoliang; Zhu, Boqian

2016-01-01

Phenotype switching of vascular smooth muscle cells (VSMC) from the contractile type to the synthetic type is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty. Inward rectifier K"+ channel 2.1 (Kir2.1) has been identified in VSMC. However, whether it plays a functional role in regulating cellular transformation remains obscure. In this study, we evaluated the role of Kir2.1 on VSMC proliferation, migration, phenotype switching, and post-injury carotid neointimal formation. Kir2.1 knockdown significantly suppressed platelet-derived growth factor BB-stimulated rat vascular smooth muscle cells (rat-VSMC) proliferation and migration. Deficiency in Kir2.1 contributed to the restoration of smooth muscle α-actin, smooth muscle 22α, and calponin and to a reduction in osteopontin expression in rat-VSMC. Moreover, the in vivo study showed that rat-VSMC switched to proliferative phenotypes and that knockdown of Kir2.1 significantly inhibited neointimal formation after rat carotid injury. Kir2.1 may be a potential therapeutic target in the treatment of cardiovascular diseases, such as atherosclerosis and restenosis following percutaneous coronary intervention.

Kir2.1 regulates rat smooth muscle cell proliferation, migration, and post-injury carotid neointimal formation

Energy Technology Data Exchange (ETDEWEB)

Qiao, Yong; Tang, Chengchun, E-mail: tangchengchun@medmail.com.cn; Wang, Qingjie; Wang, Dong; Yan, Gaoliang; Zhu, Boqian

2016-09-02

Phenotype switching of vascular smooth muscle cells (VSMC) from the contractile type to the synthetic type is a hallmark of vascular disorders such as atherosclerosis and restenosis after angioplasty. Inward rectifier K{sup +} channel 2.1 (Kir2.1) has been identified in VSMC. However, whether it plays a functional role in regulating cellular transformation remains obscure. In this study, we evaluated the role of Kir2.1 on VSMC proliferation, migration, phenotype switching, and post-injury carotid neointimal formation. Kir2.1 knockdown significantly suppressed platelet-derived growth factor BB-stimulated rat vascular smooth muscle cells (rat-VSMC) proliferation and migration. Deficiency in Kir2.1 contributed to the restoration of smooth muscle α-actin, smooth muscle 22α, and calponin and to a reduction in osteopontin expression in rat-VSMC. Moreover, the in vivo study showed that rat-VSMC switched to proliferative phenotypes and that knockdown of Kir2.1 significantly inhibited neointimal formation after rat carotid injury. Kir2.1 may be a potential therapeutic target in the treatment of cardiovascular diseases, such as atherosclerosis and restenosis following percutaneous coronary intervention.

Direct evidence of fiber type-dependent GLUT-4 expression in human skeletal muscle

DEFF Research Database (Denmark)

Gaster, M; Poulsen, P; Handberg, A

2000-01-01

GLUT-4 expression in individual fibers of human skeletal muscles in younger and older adults was studied. Furthermore, the dependency of insulin-stimulated glucose uptake on fiber type distribution was investigated. Fiber type distribution was determined in cryosections of muscle biopsies from 8...... of slow fibers in the young (r = -0.45, P > 0.25) or in the elderly (r = 0. 11, P > 0.75) subjects. In conclusion, in human skeletal muscle, GLUT-4 expression is fiber type dependent and decreases with age, particularly in fast muscle fibers....

Mechanical muscle function, morphology, and fiber type in lifelong trained elderly

DEFF Research Database (Denmark)

Aagaard, Per; Magnusson, Peter S; Larsson, Benny

2007-01-01

compared with U, and S also demonstrated greater type II fiber CSA than did U and E. The proportion of type I fibers was greater in E compared with U and S. CONCLUSIONS: Muscle fiber size and mechanical muscle performance, particularly RFD, were consistently elevated in aged individuals exposed to chronic...

File list: His.Emb.20.AllAg.Muscle_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Emb.20.AllAg.Muscle_cells dm3 Histone Embryo Muscle cells SRX110783,SRX110777,S...RX110779,SRX110778,SRX110776 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.20.AllAg.Muscle_cells.bed ...

File list: His.Emb.50.AllAg.Muscle_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Emb.50.AllAg.Muscle_cells dm3 Histone Embryo Muscle cells SRX110783,SRX110777,S...RX110778,SRX110776,SRX110779 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.50.AllAg.Muscle_cells.bed ...

File list: His.Emb.05.AllAg.Muscle_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Emb.05.AllAg.Muscle_cells dm3 Histone Embryo Muscle cells SRX110776,SRX110778,S...RX110777,SRX110779,SRX110783 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.05.AllAg.Muscle_cells.bed ...

File list: His.Emb.10.AllAg.Muscle_cells [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Emb.10.AllAg.Muscle_cells dm3 Histone Embryo Muscle cells SRX110776,SRX110777,S...RX110783,SRX110778,SRX110779 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Emb.10.AllAg.Muscle_cells.bed ...

Increased mitochondrial substrate sensitivity in skeletal muscle of patients with type 2 diabetes

DEFF Research Database (Denmark)

Larsen, S; Stride, N; Hey-Mogensen, Martin

2011-01-01

AIMS/HYPOTHESIS: Mitochondrial respiration has been linked to insulin resistance. We studied mitochondrial respiratory capacity and substrate sensitivity in patients with type 2 diabetes (patients), and obese and lean control participants. METHODS: Mitochondrial respiration was measured.......4). Substrate sensitivity for octanoyl-carnitine did not differ between groups. CONCLUSIONS/INTERPRETATION: Increased mitochondrial substrate sensitivity is seen in skeletal muscle from type 2 diabetic patients and is confined to non-lipid substrates. Respiratory capacity per mitochondrion is not decreased...... and maximal oxygen uptake (VO2) were also determined. Insulin sensitivity was determined with the isoglycaemic-hyperinsulinaemic clamp technique. RESULTS: Insulin sensitivity was different (p

The nanostructure of myoendothelial junctions contributes to signal rectification between endothelial and vascular smooth muscle cells

DEFF Research Database (Denmark)

Brasen, Jens Christian; Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik

2012-01-01

Micro-anatomical structures in tissues have potential physiological effects. In arteries and arterioles smooth muscle cells and endothelial cells are separated by the internal elastic lamina, but the two cell layers often make contact through micro protrusions called myoendothelial junctions. Cross...... types and the myoendothelial junction. The model is implemented as a 2D axi-symmetrical model and solved using the finite element method. We have simulated diffusion of Ca(2+) and IP(3) between the two cell types and we show that the micro-anatomical structure of the myoendothelial junction in itself...

Anti-tumor activity of high-dose EGFR tyrosine kinase inhibitor and sequential docetaxel in wild type EGFR non-small cell lung cancer cell nude mouse xenografts

OpenAIRE

Tang, Ning; Zhang, Qianqian; Fang, Shu; Han, Xiao; Wang, Zhehai

2016-01-01

Treatment of non-small-cell lung cancer (NSCLC) with wild-type epidermal growth factor receptor (EGFR) is still a challenge. This study explored antitumor activity of high-dose icotinib (an EGFR tyrosine kinase inhibitor) plus sequential docetaxel against wild-type EGFR NSCLC cells-generated nude mouse xenografts. Nude mice were subcutaneously injected with wild-type EGFR NSCLC A549 cells and divided into different groups for 3-week treatment. Tumor xenograft volumes were monitored and record...

Strength training increases the size of the satellite cell pool in type I and II fibres of chronically painful trapezius muscle in females

DEFF Research Database (Denmark)

Mackey, Abigail; Andersen, Lars L; Frandsen, Ulrik

2011-01-01

) and general fitness training (GFT, n = 16) to augment the satellite cell (SC) and macrophage pools in the trapezius muscles of women diagnosed with trapezius myalgia. A group receiving general health information (REF, n = 8) served as a control. Muscle biopsies were collected from the trapezius muscles...

File list: Pol.Emb.20.AllAg.Muscle_cells [Chip-atlas[Archive

Lifescience Database Archive (English)