WorldWideScience

Sample records for muscle cell function

  1. Smooth muscle cells largely develop independently of functional hemogenic endothelium

    Directory of Open Access Journals (Sweden)

    Monika Stefanska

    2014-01-01

    Full Text Available Vascular smooth muscle cells represent a major component of the cardiovascular system. In vitro studies have shown that FLK1+ cells derived from embryonic stem (ES cells can differentiate into both endothelial and smooth muscle cells. These FLK1+ cells also contain a mesodermal precursor, the hemangioblast, able to produce endothelial, blood and smooth muscle cells. The generation of blood precursors from the hemangioblast was recently shown to occur through a transient cell population of specialised endothelium, a hemogenic endothelium. To date, the lineage relationship between this cell population and smooth muscle cell progenitors has not been investigated. In this study, we generated a reporter ES cell line in which expression of the fluorescent protein H2B-VENUS is driven by the α-smooth muscle actin (α-SMA regulatory sequences. We demonstrated that this reporter cell line efficiently trace smooth muscle development during ES cell differentiation. Although some smooth muscle cells are associated with broad endothelial development, we established that smooth muscle cells are mostly generated independently from a specialised functional hemogenic endothelium. This study provides new and important insights into hematopoietic and vascular development, which may help in driving further progress towards the development of bioengineered vascular grafts for regenerative medicine.

  2. 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.

  3. Muscle glycogen and cell function - Location, location, location

    DEFF Research Database (Denmark)

    Ørtenblad, N; Nielsen, Joachim

    2015-01-01

    , and immobilization. Furthermore, these defined pools may serve specific functions in the cell. Specifically, reduced levels of these pools of glycogen are associated with reduced SR Ca(2+) release, muscle relaxation rate, and membrane excitability. Collectively, the available literature strongly demonstrates...... that the subcellular localization of glycogen has to be considered to fully understand the role of glycogen metabolism and signaling in skeletal muscle function. Here, we propose that the effect of low muscle glycogen on excitation-contraction coupling may serve as a built-in mechanism, which links the energetic state...

  4. Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Shin Fujimaki

    2016-01-01

    Full Text Available Skeletal muscle represents a plentiful and accessible source of adult stem cells. Skeletal-muscle-derived stem cells, termed satellite cells, play essential roles in postnatal growth, maintenance, repair, and regeneration of skeletal muscle. Although it is well known that the number of satellite cells increases following physical exercise, functional alterations in satellite cells such as proliferative capacity and differentiation efficiency following exercise and their molecular mechanisms remain unclear. Here, we found that functional overload, which is widely used to model resistance exercise, causes skeletal muscle hypertrophy and converts satellite cells from quiescent state to activated state. Our analysis showed that functional overload induces the expression of MyoD in satellite cells and enhances the proliferative capacity and differentiation potential of these cells. The changes in satellite cell properties coincided with the inactivation of Notch signaling and the activation of Wnt signaling and likely involve modulation by transcription factors of the Sox family. These results indicate the effects of resistance exercise on the regulation of satellite cells and provide insight into the molecular mechanism of satellite cell activation following physical exercise.

  5. 3D Cell Printing of Functional Skeletal Muscle Constructs Using Skeletal Muscle-Derived Bioink.

    Science.gov (United States)

    Choi, Yeong-Jin; Kim, Taek Gyoung; Jeong, Jonghyeon; Yi, Hee-Gyeong; Park, Ji Won; Hwang, Woonbong; Cho, Dong-Woo

    2016-10-01

    Engineered skeletal muscle tissues that mimic the structure and function of native muscle have been considered as an alternative strategy for the treatment of various muscular diseases and injuries. Here, it is demonstrated that 3D cell-printing of decellularized skeletal muscle extracellular matrix (mdECM)-based bioink facilitates the fabrication of functional skeletal muscle constructs. The cellular alignment and the shape of the tissue constructs are controlled by 3D cell-printing technology. mdECM bioink provides the 3D cell-printed muscle constructs with a myogenic environment that supports high viability and contractility as well as myotube formation, differentiation, and maturation. More interestingly, the preservation of agrin is confirmed in the mdECM, and significant increases in the formation of acetylcholine receptor clusters are exhibited in the 3D cell-printed muscle constructs. In conclusion, mdECM bioink and 3D cell-printing technology facilitate the mimicking of both the structural and functional properties of native muscle and hold great promise for producing clinically relevant engineered muscle for the treatment of muscular injuries.

  6. Transcriptional networks that regulate muscle stem cell function.

    Science.gov (United States)

    Punch, Vincent G; Jones, Andrew E; Rudnicki, Michael A

    2009-01-01

    Muscle stem cells comprise different populations of stem and progenitor cells found in embryonic and adult tissues. A number of signaling and transcriptional networks are responsible for specification and survival of these cell populations and regulation of their behavior during growth and regeneration. Muscle progenitor cells are mostly derived from the somites of developing embryos, while satellite cells are the progenitor cells responsible for the majority of postnatal growth and adult muscle regeneration. In resting muscle, these stem cells are quiescent, but reenter the cell cycle during their activation, whereby they undergo decisions to self-renew, proliferate, or differentiate and fuse into multinucleated myofibers to repair damaged muscle. Regulation of muscle stem cell activity is under the precise control of a number of extrinsic signaling pathways and active transcriptional networks that dictate their behavior, fate, and regenerative potential. Here, we review the networks responsible for these different aspects of muscle stem cell biology and discuss prevalent parallels between mechanisms regulating the activity of embryonic muscle progenitor cells and adult satellite cells.

  7. Defining an olfactory receptor function in airway smooth muscle cells

    Science.gov (United States)

    Aisenberg, William H.; Huang, Jessie; Zhu, Wanqu; Rajkumar, Premraj; Cruz, Randy; Santhanam, Lakshmi; Natarajan, Niranjana; Yong, Hwan Mee; De Santiago, Breann; Oh, Jung Jin; Yoon, A-Rum; Panettieri, Reynold A.; Homann, Oliver; Sullivan, John K.; Liggett, Stephen B.; Pluznick, Jennifer L.; An, Steven S.

    2016-01-01

    Pathways that control, or can be exploited to alter, the increase in airway smooth muscle (ASM) mass and cellular remodeling that occur in asthma are not well defined. Here we report the expression of odorant receptors (ORs) belonging to the superfamily of G-protein coupled receptors (GPCRs), as well as the canonical olfaction machinery (Golf and AC3) in the smooth muscle of human bronchi. In primary cultures of isolated human ASM, we identified mRNA expression for multiple ORs. Strikingly, OR51E2 was the most highly enriched OR transcript mapped to the human olfactome in lung-resident cells. In a heterologous expression system, OR51E2 trafficked readily to the cell surface and showed ligand selectivity and sensitivity to the short chain fatty acids (SCFAs) acetate and propionate. These endogenous metabolic byproducts of the gut microbiota slowed the rate of cytoskeletal remodeling, as well as the proliferation of human ASM cells. These cellular responses in vitro were found in ASM from non-asthmatics and asthmatics, and were absent in OR51E2-deleted primary human ASM. These results demonstrate a novel chemo-mechanical signaling network in the ASM and serve as a proof-of-concept that a specific receptor of the gut-lung axis can be targeted to treat airflow obstruction in asthma. PMID:27905542

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

    OpenAIRE

    Matthew Emerson Randolph; 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, such that certain genetic mutations specifically alter muscle function in only a subset of muscles. Additionally, defective muscle stem cells have been implicated in t...

  9. Impaired Arterial Smooth Muscle Cell Vasodilatory Function In Methamphetamine Users

    Directory of Open Access Journals (Sweden)

    Ghaemeh Nabaei

    2017-02-01

    Full Text Available Objectives: Methamphetamine use is a strong risk factor for stroke. This study was designed to evaluate arterial function and structure in methamphetamine users ultrasonographically. Methods: In a cross-sectional study, 20 methamphetamine users and 21 controls, aged between 20 and 40years, were enrolled. Common carotid artery intima-media thickness (CCA-IMT marker of early atherogenesis, flow-mediated dilatation (FMD determinants of endothelium-dependent vasodilation, and nitroglycerine-mediated dilatation (NMD independent marker of vasodilation were measured in two groups. Results: There were no significant differences between the two groups regarding demographic and metabolic characteristics. The mean (±SD CCA-IMT in methamphetamine users was 0.58±0.09mm, versus 0.59±0.07mm in the controls (p=0.84. Likewise, FMD% was not significantly different between the two groups [7.6±6.1% in methamphetamine users vs. 8.2±5.1% in the controls; p=0.72], nor were peak flow and shear rate after hyperemia. However, NMD% was considerably decreased in the methamphetamine users [8.5±7.8% in methamphetamine users vs. 13.4±6.2% in controls; p=0.03]. Conclusion: According to our results, NMD is reduced among otherwise healthy methamphetamine users, which represents smooth muscle dysfunction in this group. This may contribute to the high risk of stroke among methamphetamine users.

  10. Extraocular muscle function testing

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003397.htm Extraocular muscle function testing To use the sharing features on this page, please enable JavaScript. Extraocular muscle function testing examines the function of the eye ...

  11. Endogenous mesenchymal stromal cells in bone marrow are required to preserve muscle function in mdx mice.

    Science.gov (United States)

    Fujita, Ryo; Tamai, Katsuto; Aikawa, Eriko; Nimura, Keisuke; Ishino, Saki; Kikuchi, Yasushi; Kaneda, Yasufumi

    2015-03-01

    The physiological role of "endogenous" bone marrow (BM) mesenchymal stromal cells (MSCs) in tissue regeneration is poorly understood. Here, we show the significant contribution of unique endogenous BM-MSC populations to muscle regeneration in Duchenne muscular dystrophy (DMD) mice (mdx). Transplantation of BM cells (BMCs) from 10-week-old mdx into 3-4-week-old mdx mice increased inflammation and fibrosis and reduced muscle function compared with mdx mice that received BMCs from 10-week-old wild-type mice, suggesting that the alteration of BMC populations in mdx mice affects the progression of muscle pathology. Two distinct MSC populations in BM, that is, hematopoietic lineage (Lin)(-) /ckit(-) /CD106(+) /CD44(+) and Lin(-) /ckit(-) /CD106(+) /CD44(-) cells, were significantly reduced in 10-week-old mdx mice in disease progression. The results of a whole-transcriptome analysis indicated that these two MSC populations have distinct gene expression profiles, indicating that the Lin(-) /ckit(-) /CD106(+) /CD44(+) and Lin(-) /ckit(-) /CD106(+) /CD44(-) MSC populations are proliferative- and dormant-state populations in BM, respectively. BM-derived Lin(-) /CD106(+) /CD44(+) MSCs abundantly migrated to damaged muscles and highly expressed tumor necrosis factor-alpha-stimulated gene/protein-6 (TSG-6), an anti-inflammatory protein, in damaged muscles. We also demonstrated that TSG-6 stimulated myoblast proliferation. The injection of Lin(-) /ckit(-) /CD106(+) /CD44(+) MSCs into the muscle of mdx mice successfully ameliorated muscle dysfunction by decreasing inflammation and enhancing muscle regeneration through TSG-6-mediated activities. Thus, we propose a novel function of the unique endogenous BM-MSC population, which countered muscle pathology progression in a DMD model.

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

    Directory of Open Access Journals (Sweden)

    Matthew Emerson Randolph

    2015-10-01

    Full Text Available 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, 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 muscular dystrophies. The biology of muscle stem cells varies depending on their embryologic origins and 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.

  13. Smooth muscle architecture within cell-dense vascular tissues influences functional contractility.

    Science.gov (United States)

    Win, Zaw; Vrla, Geoffrey D; Steucke, Kerianne E; Sevcik, Emily N; Hald, Eric S; Alford, Patrick W

    2014-12-01

    The role of vascular smooth muscle architecture in the function of healthy and dysfunctional vessels is poorly understood. We aimed at determining the relationship between vascular smooth muscle architecture and contractile output using engineered vascular tissues. We utilized microcontact printing and a microfluidic cell seeding technique to provide three different initial seeding conditions, with the aim of influencing the cellular architecture within the tissue. Cells seeded in each condition formed confluent and aligned tissues but within the tissues, the cellular architecture varied. Tissues with a more elongated cellular architecture had significantly elevated basal stress and produced more contractile stress in response to endothelin-1 stimulation. We also found a correlation between the contractile phenotype marker expression and the cellular architecture, contrary to our previous findings in non-confluent tissues. Taken with previous results, these data suggest that within cell-dense vascular tissues, smooth muscle contractility is strongly influenced by cell and tissue architectures.

  14. Bimodal impact of skeletal muscle on pancreatic β-cell function in health and disease

    DEFF Research Database (Denmark)

    Plomgaard, P; Halban, P A; Bouzakri, K

    2012-01-01

    of diabetes. Far from being an inert tissue in terms of inter-organ communication, it is now recognized that skeletal muscle can secrete so-called myokines that can impact on the function of distant organs/tissues both favourably and unfavourably. We have proposed that communication between insulin......-resistant skeletal muscle and β-cells occurs in diabetes. This is a novel route of communication that we further suggest is modified by the prevailing degree of insulin resistance of skeletal muscle. This review focuses on the various myokines [interleukin-6 (IL-6), tumor necrosis factor-α, CXCL10, follistatin...... and IL-8] which have been identified either after different types of exercise or in the secretome from control and insulin-resistant human skeletal myotubes. We will also summarize studies on the impact of several myokines on pancreatic β-cell proliferation, survival and function....

  15. Effects of polydopamine functionalized titanium dioxide nanotubes on endothelial cell and smooth muscle cell.

    Science.gov (United States)

    Zhong, Si; Luo, Rifang; Wang, Xin; Tang, Linlin; Wu, Jian; Wang, Jin; Huang, Runbo; Sun, Hong; Huang, Nan

    2014-04-01

    Previous investigations have demonstrated that TiO2 nanotubes (NTs) with particular structure cues could control the behavior of different types of cells, including endothelial cells (ECs) and smooth muscle cells (SMCs). Besides, polydopamine (PDA) modified surfaces were reported to be beneficial to increase the proliferation and viability of ECs and meanwhile could inhibit the proliferation of SMCs. The TiO2 nanotubes (NTs) were functionalized with polydopamine (PDA) (PDA/NTs) to study the synergetic effect of both nanotopography (NTs) and chemical cues (PDA) of TiO2 nanotubes on the regulation of cellular behavior of ECs and SMCs. The PDA-modified TiO2 nanotubes were subjected to field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) analysis. In vitro cell culture tests confirmed that, comparing with flat titanium (Ti) and TiO2 nanotubes, PDA/NTs surface synergistically promoted ECs attachment, proliferation, migration and release of nitric oxide (NO). Meanwhile, the PDA/NTs performed well in reducing SMCs adhesion and proliferation. This novel approach might provide a new platform to investigate the synergistic effect of local chemistry and topography, as well as the applications for the development of titanium-based implants for enhanced endothelialization. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Reduced masticatory function is related to lower satellite cell numbers in masseter muscle.

    Science.gov (United States)

    Kuijpers, M A R; Grefte, S; Bronkhorst, E M; Carels, C E L; Kiliaridis, S; Von den Hoff, J W

    2014-06-01

    The physiology of masseter muscles is known to change in response to functional demands, but the effect on the satellite cell (SC) population is not known. In this study, the hypothesis is tested that a decreased functional demand of the masseter muscle causes a reduction of SCs. To this end, twelve 5-week-old male Sprague-Dawley rats were put on a soft diet (SD, n = 6) or a hard diet (HD, n = 6) and sacrificed after 14 days. Paraffin sections of the superficial masseter and the m. digastricus (control muscle) were stained with haematoxylin and eosin for tissue survey and with anti-myosin heavy chain (MHC) for slow and fast fibres. Frozen sections of both muscles were double-stained for collagen type IV and Pax7. Slow MHC fibres were equally distributed in the m. digastricus but only localized in a small area of the m. masseter. No differences between HD or SD for the m. digastricus were found. The m. masseter had more SCs per fibre in HD than in SD (0.093 ± 0.007 and 0.081 ± 0.008, respectively; P = 0.027). The m. masseter had more fibres per surface area than the m. digastricus in rats with an SD group (758.1 ± 101.6 and 568.4 ± 85.6, P = 0.047) and a HD group (737.7 ± 32.6 and 592.2 ± 82.2; P = 0.007). The m. digastricus had more SCs per fibre than the m. masseter in the SD group (0.094 ± 0.01 and 0.081 ± 0.008; P = 0.039). These results suggest that reduced masseter muscle function is related to a lower number of SCs. Reduced muscle function might decrease microdamage and hence the requirement of SCs in the muscle fibres.

  17. Decreased β-Cell Function Is Associated with Reduced Skeletal Muscle Mass in Japanese Subjects without Diabetes

    Science.gov (United States)

    Sakai, Satoshi; Tanimoto, Keiji; Imbe, Ayumi; Inaba, Yuiko; Shishikura, Kanako; Tanimoto, Yoshimi; Ushiroyama, Takahisa; Terasaki, Jungo; Hanafusa, Toshiaki

    2016-01-01

    Background Decreased insulin secretion has a great impact on the incidence of type 2 diabetes in Japanese subjects. It is not clear whether β-cell function is related to muscle mass in subjects without diabetes. We investigated the relationship between β-cell function and skeletal muscle mass in Japanese subjects without diabetes. Methods The study included 1098 subjects (538 men and 560 women) aged 40 to 79 years, without diabetes (fasting glucose lower than 126 mg/dL and glycosylated hemoglobin lower than 6.5%), who consulted Osaka Medical College Health Science Clinic for a medical examination. Appendicular muscle mass was measured by bioelectrical impedance analysis. Appendicular muscle mass index was calculated as appendicular muscle mass divided by height squared (kg/m2). The homeostatic model assessment of β-cell function was used to assess β-cell function. The homeostatic model assessment of insulin resistance was used as a measure of insulin resistance. The association between appendicular muscle mass index and clinical parameters of β-cell function and insulin resistance was examined. Results Log-transformed homeostatic model assessment of β-cell function and Log-transformed homeostatic model assessment of insulin resistance showed a normal distribution. In both men and women, there was a significant positive correlation between appendicular muscle mass index and clinical parameters of β-cell function and insulin resistance. Tertile analysis, following stratification according to appendicular muscle mass index, found that low appendicular muscle mass index was significantly associated with the Log homeostatic model assessment of β-cell function and Log-transformed homeostatic model assessment of insulin resistance. Conclusion This study shows that decreased β cell function is associated with reduced skeletal muscle mass in Japanese subjects without diabetes. PMID:27612202

  18. Distinct function of estrogen receptor α in smooth muscle and fibroblast cells in prostate development.

    Science.gov (United States)

    Vitkus, Spencer; Yeh, Chiuan-Ren; Lin, Hsiu-Hsia; Hsu, Iawen; Yu, Jiangzhou; Chen, Ming; Yeh, Shuyuan

    2013-01-01

    Estrogen signaling, through estrogen receptor (ER)α, has been shown to cause hypertrophy in the prostate. Our recent report has shown that epithelial ERα knockout (KO) will not affect the normal prostate development or homeostasis. However, it remains unclear whether ERα in different types of stromal cells has distinct roles in prostate development. This study proposed to elucidate how KO of ERα in the stromal smooth muscle or fibroblast cells may interrupt cross talk between prostate stromal and epithelial cells. Smooth muscle ERαKO (smERαKO) mice showed decreased glandular infolding with the proximal area exhibiting a significant decrease. Fibroblast ERαKO mouse prostates did not exhibit this phenotype but showed a decrease in the number of ductal tips. Additionally, the amount of collagen observed in the basement membrane was reduced in smERαKO prostates. Interestingly, these phenotypes were found to be mutually exclusive among smERαKO or fibroblast ERαKO mice. Compound KO of ERα in both fibroblast and smooth muscle showed combined phenotypes from each of the single KO. Further mechanistic studies showed that IGF-I and epidermal growth factor were down-regulated in prostate smooth muscle PS-1 cells lacking ERα. Together, our results indicate the distinct functions of fibroblast vs. smERα in prostate development.

  19. Short-term calorie restriction enhances skeletal muscle stem cell function

    National Research Council Canada - National Science Library

    Cerletti, Massimiliano; Jang, Young C; Finley, Lydia W S; Haigis, Marcia C; Wagers, Amy J

    2012-01-01

    ... metabolic and longevity regulators. Moreover, CR enhanced endogenous muscle repair and CR initiated in either donor or recipient animals improved the contribution of donor cells to regenerating muscle after transplant...

  20. [Primary culture and functional identification of distal pulmonary artery smooth muscle cells in mice].

    Science.gov (United States)

    Li, M C; Chen, Y Q; Zhang, C T; Jiang, Q; Lu, W J; Wang, J

    2017-02-12

    Objective: To establish a method of isolation and primary culture of mice distal pulmonary artery smooth muscle cells (PASMCs) and identify the functional properties. Methods: PASMCs were harvested from the distal pulmonary artery (PA) tissue of mice by enzymatic digestion of collagenaseⅠand papain; and the growth characteristics were observed under inverted microscope and identified by Immunofluorescence technique. Effects on the intracellular calcium ion concentration of distal PASMCs were detected by Fura-2-AM fluorescent probe tracer under a fluorescence microscope in Krebs solution containing clopiazonic acid (CPA) and nifedipin (Nif). Results: PASMCs density reached approximately to 80% in a typical valley-peak-like shape after 6 days. Cell α-smooth muscle actin (α-SMA) immunofluorescence identified that 95% of the cultured cells were PASMCs. More than 95% PASMCs responded well to calcium-potassium Krebs solution (potassium ion concentration of 60 mmol/L) and showed a rapid increase in basal [Ca(2+) ](i) after 1 minute's perfusion (Δ[Ca(2+) ](i)>50), which demonstrated that the voltage-dependent calcium channels (VDCC) of distal PASMCs were in good function; after the perfusion of calcium Krebs, calcium-free/calcium-Krebs containing CPA and Nif, distal PASMCs showed two typical peaks, indicated the full function of store-operated calcium channel (SOCC) in distal PASMCs. Conclusion: This experiment successfully established a stable and reliable mice distal PASMCs model and the study of pulmonary vascular diseases could benefit from its higher purity and better functional condition.

  1. Androgen action via testicular arteriole smooth muscle cells is important for Leydig cell function, vasomotion and testicular fluid dynamics.

    Directory of Open Access Journals (Sweden)

    Michelle Welsh

    Full Text Available Regulation of blood flow through the testicular microvasculature by vasomotion is thought to be important for normal testis function as it regulates interstitial fluid (IF dynamics which is an important intra-testicular transport medium. Androgens control vasomotion, but how they exert these effects remains unclear. One possibility is by signalling via androgen receptors (AR expressed in testicular arteriole smooth muscle cells. To investigate this and determine the overall importance of this mechanism in testis function, we generated a blood vessel smooth muscle cell-specific AR knockout mouse (SMARKO. Gross reproductive development was normal in SMARKO mice but testis weight was reduced in adulthood compared to control littermates; this reduction was not due to any changes in germ cell volume or to deficits in testosterone, LH or FSH concentrations and did not cause infertility. However, seminiferous tubule lumen volume was reduced in adult SMARKO males while interstitial volume was increased, perhaps indicating altered fluid dynamics; this was associated with compensated Leydig cell failure. Vasomotion was impaired in adult SMARKO males, though overall testis blood flow was normal and there was an increase in the overall blood vessel volume per testis in adult SMARKOs. In conclusion, these results indicate that ablating arteriole smooth muscle AR does not grossly alter spermatogenesis or affect male fertility but does subtly impair Leydig cell function and testicular fluid exchange, possibly by locally regulating microvascular blood flow within the testis.

  2. Experimental studies of mitochondrial function in CADASIL vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Viitanen, Matti [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Department of Geriatrics, Turku City Hospital and University of Turku, Turku (Finland); Sundström, Erik [Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Baumann, Marc [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Poyhonen, Minna [Department of Clinical Genetics, Helsinki University Hospital, HUSLAB, Helsinki (Finland); Tikka, Saara [Protein Chemistry Unit, Institute of Biomedicine/Anatomy, University of Helsinki, Helsinki (Finland); Behbahani, Homira, E-mail: homira.behbahani@ki.se [Division of Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden); Karolinska Institutet Alzheimer' s Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm (Sweden)

    2013-02-01

    Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a familiar fatal progressive degenerative disorder characterized by cognitive decline, and recurrent stroke in young adults. Pathological features include a dramatic reduction of brain vascular smooth muscle cells and severe arteriopathy with the presence of granular osmophilic material in the arterial walls. Here we have investigated the cellular and mitochondrial function in vascular smooth muscle cell lines (VSMCs) established from CADASIL mutation carriers (R133C) and healthy controls. We found significantly lower proliferation rates in CADASIL VSMC as compared to VSMC from controls. Cultured CADASIL VSMCs were not more vulnerable than control cells to a number of toxic substances. Morphological studies showed reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs. Transmission electron microscopy analysis demonstrated increased irregular and abnormal mitochondria in CADASIL VSMCs. Measurements of mitochondrial membrane potential (Δψ{sub m}) showed a lower percentage of fully functional mitochondria in CADASIL VSMCs. For a number of genes previously reported to be changed in CADASIL VSMCs, immunoblotting analysis demonstrated a significantly reduced SOD1 expression. These findings suggest that alteration of proliferation and mitochondrial function in CADASIL VSMCs might have an effect on vital cellular functions important for CADASIL pathology. -- Highlights: ► CADASIL is an inherited disease of cerebral vascular cells. ► Mitochondrial dysfunction has been implicated in the pathogenesis of CADASIL. ► Lower proliferation rates in CADASIL VSMC. ► Increased irregular and abnormal mitochondria and lower mitochondrial membrane potential in CADASIL VSMCs. ► Reduced mitochondrial connectivity and increased number of mitochondria in CADASIL VSMCs.

  3. Oxidative stress induces caveolin 1 degradation and impairs caveolae functions in skeletal muscle cells.

    Directory of Open Access Journals (Sweden)

    Alexis Mougeolle

    Full Text Available Increased level of oxidative stress, a major actor of cellular aging, impairs the regenerative capacity of skeletal muscle and leads to the reduction in the number and size of muscle fibers causing sarcopenia. Caveolin 1 is the major component of caveolae, small membrane invaginations involved in signaling and endocytic trafficking. Their role has recently expanded to mechanosensing and to the regulation of oxidative stress-induced pathways. Here, we increased the amount of reactive oxidative species in myoblasts by addition of hydrogen peroxide (H2O2 at non-toxic concentrations. The expression level of caveolin 1 was significantly decreased as early as 10 min after 500 μM H2O2 treatment. This reduction was not observed in the presence of a proteasome inhibitor, suggesting that caveolin 1 was rapidly degraded by the proteasome. In spite of caveolin 1 decrease, caveolae were still able to assemble at the plasma membrane. Their functions however were significantly perturbed by oxidative stress. Endocytosis of a ceramide analog monitored by flow cytometry was significantly diminished after H2O2 treatment, indicating that oxidative stress impaired its selective internalization via caveolae. The contribution of caveolae to the plasma membrane reservoir has been monitored after osmotic cell swelling. H2O2 treatment increased membrane fragility revealing that treated cells were more sensitive to an acute mechanical stress. Altogether, our results indicate that H2O2 decreased caveolin 1 expression and impaired caveolae functions. These data give new insights on age-related deficiencies in skeletal muscle.

  4. Common and Distinctive Functions of the Hippo Effectors Taz and Yap in Skeletal Muscle Stem Cell Function.

    Science.gov (United States)

    Sun, Congshan; De Mello, Vanessa; Mohamed, Abdalla; Ortuste Quiroga, Huascar P; Garcia-Munoz, Amaya; Al Bloshi, Abdullah; Tremblay, Annie M; von Kriegsheim, Alexander; Collie-Duguid, Elaina; Vargesson, Neil; Matallanas, David; Wackerhage, Henning; Zammit, Peter S

    2017-08-01

    Hippo pathway downstream effectors Yap and Taz play key roles in cell proliferation and regeneration, regulating gene expression especially via Tead transcription factors. To investigate their role in skeletal muscle stem cells, we analyzed Taz in vivo and ex vivo in comparison with Yap. Small interfering RNA knockdown or retroviral-mediated expression of wild-type human or constitutively active TAZ mutants in satellite cells showed that TAZ promoted proliferation, a function shared with YAP. However, at later stages of myogenesis, TAZ also enhanced myogenic differentiation of myoblasts, whereas YAP inhibits such differentiation. Functionally, while muscle growth was mildly affected in Taz (gene Wwtr1(-/-) ) knockout mice, there were no overt effects on regeneration. Conversely, conditional knockout of Yap in satellite cells of Pax7(Cre-ERT2/+) : Yap(fl) °(x/fl) °(x) :Rosa26(Lacz) mice produced a regeneration deficit. To identify potential mechanisms, microarray analysis showed many common TAZ/YAP target genes, but TAZ also regulates some genes independently of YAP, including myogenic genes such as Pax7, Myf5, and Myod1 (ArrayExpress-E-MTAB-5395). Proteomic analysis revealed many novel binding partners of TAZ/YAP in myogenic cells, but TAZ also interacts with proteins distinct from YAP that are often involved in myogenesis and aspects of cytoskeleton organization (ProteomeXchange-PXD005751). Neither TAZ nor YAP bind members of the Wnt destruction complex but both regulated expression of Wnt and Wnt-cross talking genes with known roles in myogenesis. Finally, TAZ operates through Tead4 to enhance myogenic differentiation. In summary, Taz and Yap have overlapping functions in promoting myoblast proliferation but Taz then switches to enhance myogenic differentiation. Stem Cells 2017;35:1958-1972. © 2017 The Authors. The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  5. Function-based discovery of significant transcriptional temporal patterns in insulin stimulated muscle cells.

    Science.gov (United States)

    Di Camillo, Barbara; Irving, Brian A; Schimke, Jill; Sanavia, Tiziana; Toffolo, Gianna; Cobelli, Claudio; Nair, K Sreekumaran

    2012-01-01

    Insulin action on protein synthesis (translation of transcripts) and post-translational modifications, especially of those involving the reversible modifications such as phosphorylation of various signaling proteins, are extensively studied but insulin effect on transcription of genes, especially of transcriptional temporal patterns remains to be fully defined. To identify significant transcriptional temporal patterns we utilized primary differentiated rat skeletal muscle myotubes which were treated with insulin and samples were collected every 20 min for 8 hours. Pooled samples at every hour were analyzed by gene array approach to measure transcript levels. The patterns of transcript levels were analyzed based on a novel method that integrates selection, clustering, and functional annotation to find the main temporal patterns associated to functional groups of differentially expressed genes. 326 genes were found to be differentially expressed in response to in vitro insulin administration in skeletal muscle myotubes. Approximately 20% of the genes that were differentially expressed were identified as belonging to the insulin signaling pathway. Characteristic transcriptional temporal patterns include: (a) a slow and gradual decrease in gene expression, (b) a gradual increase in gene expression reaching a peak at about 5 hours and then reaching a plateau or an initial decrease and other different variable pattern of increase in gene expression over time. The new method allows identifying characteristic dynamic responses to insulin stimulus, common to a number of genes and associated to the same functional group. The results demonstrate that insulin treatment elicited different clusters of gene transcript profile supporting a temporal regulation of gene expression by insulin in skeletal muscle cells.

  6. Function-based discovery of significant transcriptional temporal patterns in insulin stimulated muscle cells.

    Directory of Open Access Journals (Sweden)

    Barbara Di Camillo

    Full Text Available BACKGROUND: Insulin action on protein synthesis (translation of transcripts and post-translational modifications, especially of those involving the reversible modifications such as phosphorylation of various signaling proteins, are extensively studied but insulin effect on transcription of genes, especially of transcriptional temporal patterns remains to be fully defined. METHODOLOGY/PRINCIPAL FINDINGS: To identify significant transcriptional temporal patterns we utilized primary differentiated rat skeletal muscle myotubes which were treated with insulin and samples were collected every 20 min for 8 hours. Pooled samples at every hour were analyzed by gene array approach to measure transcript levels. The patterns of transcript levels were analyzed based on a novel method that integrates selection, clustering, and functional annotation to find the main temporal patterns associated to functional groups of differentially expressed genes. 326 genes were found to be differentially expressed in response to in vitro insulin administration in skeletal muscle myotubes. Approximately 20% of the genes that were differentially expressed were identified as belonging to the insulin signaling pathway. Characteristic transcriptional temporal patterns include: (a a slow and gradual decrease in gene expression, (b a gradual increase in gene expression reaching a peak at about 5 hours and then reaching a plateau or an initial decrease and other different variable pattern of increase in gene expression over time. CONCLUSION/SIGNIFICANCE: The new method allows identifying characteristic dynamic responses to insulin stimulus, common to a number of genes and associated to the same functional group. The results demonstrate that insulin treatment elicited different clusters of gene transcript profile supporting a temporal regulation of gene expression by insulin in skeletal muscle cells.

  7. Tropomyosin variants describe distinct functional subcellular domains in differentiated vascular smooth muscle cells.

    Science.gov (United States)

    Gallant, Cynthia; Appel, Sarah; Graceffa, Philip; Leavis, Paul; Lin, Jim Jung-Ching; Gunning, Peter W; Schevzov, Galina; Chaponnier, Christine; DeGnore, Jon; Lehman, William; Morgan, Kathleen G

    2011-06-01

    Tropomyosin (Tm) is known to be an important gatekeeper of actin function. Tm isoforms are encoded by four genes, and each gene produces several variants by alternative splicing, which have been proposed to play roles in motility, proliferation, and apoptosis. Smooth muscle studies have focused on gizzard smooth muscle, where a heterodimer of Tm from the α-gene (Tmsm-α) and from the β-gene (Tmsm-β) is associated with contractile filaments. In this study we examined Tm in differentiated mammalian vascular smooth muscle (dVSM). Liquid chromatography-tandem mass spectrometry (LC MS/MS) analysis and Western blot screening with variant-specific antibodies revealed that at least five different Tm proteins are expressed in this tissue: Tm6 (Tmsm-α) and Tm2 from the α-gene, Tm1 (Tmsm-β) from the β-gene, Tm5NM1 from the γ-gene, and Tm4 from the δ-gene. Tm6 is by far most abundant in dVSM followed by Tm1, Tm2, Tm5NM1, and Tm4. Coimmunoprecipitation and coimmunofluorescence studies demonstrate that Tm1 and Tm6 coassociate with different actin isoforms and display different intracellular localizations. Using an antibody specific for cytoplasmic γ-actin, we report here the presence of a γ-actin cortical cytoskeleton in dVSM cells. Tm1 colocalizes with cortical cytoplasmic γ-actin and coprecipitates with γ-actin. Tm6, on the other hand, is located on contractile bundles. These data indicate that Tm1 and Tm6 do not form a classical heterodimer in dVSM but rather describe different functional cellular compartments.

  8. Bitter taste receptor agonists alter mitochondrial function and induce autophagy in airway smooth muscle cells.

    Science.gov (United States)

    Pan, Shi; Sharma, Pawan; Shah, Sushrut D; Deshpande, Deepak A

    2017-07-01

    Airway remodeling, including increased airway smooth muscle (ASM) mass, is a hallmark feature of asthma and COPD. We previously identified the expression of bitter taste receptors (TAS2Rs) on human ASM cells and demonstrated that known TAS2R agonists could promote ASM relaxation and bronchodilation and inhibit mitogen-induced ASM growth. In this study, we explored cellular mechanisms mediating the antimitogenic effect of TAS2R agonists on human ASM cells. Pretreatment of ASM cells with TAS2R agonists chloroquine and quinine resulted in inhibition of cell survival, which was largely reversed by bafilomycin A1, an autophagy inhibitor. Transmission electron microscope studies demonstrated the presence of double-membrane autophagosomes and deformed mitochondria. In ASM cells, TAS2R agonists decreased mitochondrial membrane potential and increased mitochondrial ROS and mitochondrial fragmentation. Inhibiting dynamin-like protein 1 (DLP1) reversed TAS2R agonist-induced mitochondrial membrane potential change and attenuated mitochondrial fragmentation and cell death. Furthermore, the expression of mitochondrial protein BCL2/adenovirus E1B 19-kDa protein-interacting protein 3 (Bnip3) and mitochondrial localization of DLP1 were significantly upregulated by TAS2R agonists. More importantly, inhibiting Bnip3 mitochondrial localization by dominant-negative Bnip3 significantly attenuated cell death induced by TAS2R agonist. Collectively the TAS2R agonists chloroquine and quinine modulate mitochondrial structure and function, resulting in ASM cell death. Furthermore, Bnip3 plays a central role in TAS2R agonist-induced ASM functional changes via a mitochondrial pathway. These findings further establish the cellular mechanisms of antimitogenic effects of TAS2R agonists and identify a novel class of receptors and pathways that can be targeted to mitigate airway remodeling as well as bronchoconstriction in obstructive airway diseases. Copyright © 2017 the American Physiological

  9. Surface-mediated functional gene delivery: an effective strategy for enhancing competitiveness of endothelial cells over smooth muscle cells.

    Science.gov (United States)

    Chang, Hao; Ren, Ke-feng; Wang, Jin-Lei; Zhang, He; Wang, Bai-liang; Zheng, Shan-mei; Zhou, Yuan-yuan; Ji, Jian

    2013-04-01

    The non-biorecognition of general biomaterials and inherent biospecificity of biological systems pose key challenges to the optimal functions of medical devices. In this study, we constructed the surface-mediated functional gene delivery through layer-by-layer self-assembly of protamine sulfate (PrS) and plasmid DNA encoding hepatocyte growth factor (HGF), aiming at specific enhancing endothelial cells (EC) compeititiveness over smooth muscle cells (SMC). Characterizations of the (PrS/HGF-pDNA) multilayered films present the linear buildup with homogeneous and flat topographical feature. The amount of DNA can be easily controlled. By using these multilayered films, both human umbilical vein endothelial cells (HUVEC) and human umbilical artery smooth muscle cells (HUASMC) can be directly transfected when they contact with the multilayered films. On transfection, increasing secretion of HGF has been detected in both HUVEC and HUASMC culture, which leads to selective promotion of HUVEC proliferation. In the co-culture experiment, we also exhibit the promoted and hindered growth of HUVEC and HUASMC, respectively, which could be attributed to the inverse influence of HUVEC on HUASMC. These results collectively demonstrate that our system can be served as a powerful tool for enhancing competitiveness of EC over SMC, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy.

  10. Airway smooth muscle cell tone amplifies contractile function in the presence of chronic cyclic strain.

    Science.gov (United States)

    Fairbank, Nigel J; Connolly, Sarah C; Mackinnon, James D; Wehry, Kathrin; Deng, Linhong; Maksym, Geoffrey N

    2008-09-01

    Chronic contractile activation, or tone, in asthma coupled with continuous stretching due to breathing may be involved in altering the contractile function of airway smooth muscle (ASM). Previously, we (11) showed that cytoskeletal remodeling and stiffening responses to acute (2 h) localized stresses were modulated by the level of contractile activation of ASM. Here, we investigated if altered contractility in response to chronic mechanical strain was dependent on repeated modulation of contractile tone. Cultured human ASM cells received 5% cyclic (0.3 Hz), predominantly uniaxial strain for 5 days, with once-daily dosing of either sham, forskolin, carbachol, or histamine to alter tone. Stiffness, contractility (KCl), and "relaxability" (forskolin) were then measured as was cell alignment, myosin light-chain phosphorylation (pMLC), and myosin light-chain kinase (MLCK) content. Cells became aligned and baseline stiffness increased with strain, but repeated lowering of tone inhibited both effects (P negative tone-modulation dependence of MLCK, observed in static conditions in agreement with previous reports, with strain and tone together increasing both MLCK and pMLC. Furthermore, contractility increased 176% (SE 59) with repeated tone elevation. These findings indicate that with strain, and not without, repeated tone elevation promoted contractile function through changes in cytoskeletal organization and increased contractile protein. The ability of repeated contractile activation to increase contractility, but only with mechanical stretching, suggests a novel mechanism for increased ASM contractility in asthma and for the role of continuous bronchodilator and corticosteroid therapy in reversing airway hyperresponsiveness.

  11. Matrix stiffness-modulated proliferation and secretory function of the airway smooth muscle cells.

    Science.gov (United States)

    Shkumatov, Artem; Thompson, Michael; Choi, Kyoung M; Sicard, Delphine; Baek, Kwanghyun; Kim, Dong Hyun; Tschumperlin, Daniel J; Prakash, Y S; Kong, Hyunjoon

    2015-06-01

    Multiple pulmonary conditions are characterized by an abnormal misbalance between various tissue components, for example, an increase in the fibrous connective tissue and loss/increase in extracellular matrix proteins (ECM). Such tissue remodeling may adversely impact physiological function of airway smooth muscle cells (ASMCs) responsible for contraction of airways and release of a variety of bioactive molecules. However, few efforts have been made to understand the potentially significant impact of tissue remodeling on ASMCs. Therefore, this study reports how ASMCs respond to a change in mechanical stiffness of a matrix, to which ASMCs adhere because mechanical stiffness of the remodeled airways is often different from the physiological stiffness. Accordingly, using atomic force microscopy (AFM) measurements, we found that the elastic modulus of the mouse bronchus has an arithmetic mean of 23.1 ± 14 kPa (SD) (median 18.6 kPa). By culturing ASMCs on collagen-conjugated polyacrylamide hydrogels with controlled elastic moduli, we found that gels designed to be softer than average airway tissue significantly increased cellular secretion of vascular endothelial growth factor (VEGF). Conversely, gels stiffer than average airways stimulated cell proliferation, while reducing VEGF secretion and agonist-induced calcium responses of ASMCs. These dependencies of cellular activities on elastic modulus of the gel were correlated with changes in the expression of integrin-β1 and integrin-linked kinase (ILK). Overall, the results of this study demonstrate that changes in matrix mechanics alter cell proliferation, calcium signaling, and proangiogenic functions in ASMCs.

  12. Effect of Delayed Peripheral Nerve Repair on Nerve Regeneration, Schwann Cell Function and Target Muscle Recovery

    Science.gov (United States)

    Jonsson, Samuel; Wiberg, Rebecca; McGrath, Aleksandra M.; Novikov, Lev N.; Wiberg, Mikael; Novikova, Liudmila N.; Kingham, Paul J.

    2013-01-01

    Despite advances in surgical techniques for peripheral nerve repair, functional restitution remains incomplete. The timing of surgery is one factor influencing the extent of recovery but it is not yet clearly defined how long a delay may be tolerated before repair becomes futile. In this study, rats underwent sciatic nerve transection before immediate (0) or 1, 3, or 6 months delayed repair with a nerve graft. Regeneration of spinal motoneurons, 13 weeks after nerve repair, was assessed using retrograde labeling. Nerve tissue was also collected from the proximal and distal stumps and from the nerve graft, together with the medial gastrocnemius (MG) muscles. A dramatic decline in the number of regenerating motoneurons and myelinated axons in the distal nerve stump was observed in the 3- and 6-months delayed groups. After 3 months delay, the axonal number in the proximal stump increased 2–3 folds, accompanied by a smaller axonal area. RT-PCR of distal nerve segments revealed a decline in Schwann cells (SC) markers, most notably in the 3 and 6 month delayed repair samples. There was also a progressive increase in fibrosis and proteoglycan scar markers in the distal nerve with increased delayed repair time. The yield of SC isolated from the distal nerve segments progressively fell with increased delay in repair time but cultured SC from all groups proliferated at similar rates. MG muscle at 3- and 6-months delay repair showed a significant decline in weight (61% and 27% compared with contra-lateral side). Muscle fiber atrophy and changes to neuromuscular junctions were observed with increased delayed repair time suggestive of progressively impaired reinnervation. This study demonstrates that one of the main limiting factors for nerve regeneration after delayed repair is the distal stump. The critical time point after which the outcome of regeneration becomes too poor appears to be 3-months. PMID:23409189

  13. Free fatty acid palmitate impairs the vitality and function of cultured human bladder smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Andreas Oberbach

    Full Text Available BACKGROUND: Incidence of urinary tract infections is elevated in patients with diabetes mellitus. Those patients show increased levels of the saturated free fatty acid palmitate. As recently shown metabolic alterations induced by palmitate include production and secretion of the pro-inflammatory cytokine interleukine-6 (IL-6 in cultured human bladder smooth muscle cells (hBSMC. Here we studied the influence of palmitate on vital cell properties, for example, regulation of cell proliferation, mitochondrial enzyme activity and antioxidant capacity in hBSMC, and analyzed the involvement of major cytokine signaling pathways. METHODOLOGY/PRINCIPAL FINDINGS: HBSMC cultures were set up from bladder tissue of patients undergoing cystectomy and stimulated with palmitate. We analyzed cell proliferation, mitochondrial enzyme activity, and antioxidant capacity by ELISA and confocal immunofluorescence. In signal transduction inhibition experiments we evaluated the involvement of NF-κB, JAK/STAT, MEK1, PI3K, and JNK in major cytokine signaling pathway regulation. We found: (i palmitate decreased cell proliferation, increased mitochondrial enzyme activity and antioxidant capacity; (ii direct inhibition of cytokine receptor by AG490 even more strongly suppressed cell proliferation in palmitate-stimulated cells, while counteracting palmitate-induced increase of antioxidant capacity; (iii in contrast knockdown of the STAT3 inhibitor SOCS3 increased cell proliferation and antioxidant capacity; (iv further downstream JAK/STAT3 signaling cascade the inhibition of PI3K or JNK enhanced palmitate induced suppression of cell proliferation; (v increase of mitochondrial enzyme activity by palmitate was enhanced by inhibition of PI3K but counteracted by inhibition of MEK1. CONCLUSIONS/SIGNIFICANCE: Saturated free fatty acids (e.g., palmitate cause massive alterations in vital cell functions of cultured hBSMC involving distinct major cytokine signaling pathways. Thereby

  14. Effects of platelet-derived growth factor on the function of smooth muscle cells from different orders of pulmonary artery

    Institute of Scientific and Technical Information of China (English)

    国桓

    2014-01-01

    Objective To explore the functional responses of normal rat pulmonary artery smooth muscle cells(PASMCs)from different orders of pulmonary artery to the platelet-derived growth factor(PDGF).Methods The pulmonary artery branches were gently isolated from Sprague-Dawley rats(250-350 g)and eventually cut into three groups according to the vascular grading:the

  15. Autologous skeletal muscle derived cells expressing a novel functional dystrophin provide a potential therapy for Duchenne Muscular Dystrophy.

    Science.gov (United States)

    Meng, Jinhong; Counsell, John R; Reza, Mojgan; Laval, Steven H; Danos, Olivier; Thrasher, Adrian; Lochmüller, Hanns; Muntoni, Francesco; Morgan, Jennifer E

    2016-01-27

    Autologous stem cells that have been genetically modified to express dystrophin are a possible means of treating Duchenne Muscular Dystrophy (DMD). To maximize the therapeutic effect, dystrophin construct needs to contain as many functional motifs as possible, within the packaging capacity of the viral vector. Existing dystrophin constructs used for transduction of muscle stem cells do not contain the nNOS binding site, an important functional motif within the dystrophin gene. In this proof-of-concept study, using stem cells derived from skeletal muscle of a DMD patient (mdcs) transplanted into an immunodeficient mouse model of DMD, we report that two novel dystrophin constructs, C1 (ΔR3-R13) and C2 (ΔH2-R23), can be lentivirally transduced into mdcs and produce dystrophin. These dystrophin proteins were functional in vivo, as members of the dystrophin glycoprotein complex were restored in muscle fibres containing donor-derived dystrophin. In muscle fibres derived from cells that had been transduced with construct C1, the largest dystrophin construct packaged into a lentiviral system, nNOS was restored. The combination of autologous stem cells and a lentivirus expressing a novel dystrophin construct which optimally restores proteins of the dystrophin glycoprotein complex may have therapeutic application for all DMD patients, regardless of their dystrophin mutation.

  16. Localization and function of KLF4 in cytoplasm of vascular smooth muscle cell

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Department of Biochemistry and Molecular Biology, The Key Laboratory of Neurobiology and Vascular Biology (China); The Third Hospital of Hebei Medical University, Shijazhuang (China); Zheng, Bin; Zhang, Xin-hua; Nie, Chan-juan; Li, Yong-hui [Department of Biochemistry and Molecular Biology, The Key Laboratory of Neurobiology and Vascular Biology (China); Wen, Jin-kun, E-mail: wjk@hebmu.edu.cn [Department of Biochemistry and Molecular Biology, The Key Laboratory of Neurobiology and Vascular Biology (China)

    2013-06-28

    Highlights: •PDGF-BB prompts the translocation of KLF4 to the cytoplasm. •PDGF-BB promotes interaction between KLF4 and actin in the cytoplasm. •Phosphorylation and SUMOylation of KLF4 participates in regulation of cytoskeletal organization. •KLF4 regulates cytoskeleton by promoting the expression of contraction-associated genes. -- Abstract: The Krüppel-like factor 4 is a DNA-binding transcriptional regulator that regulates a diverse array of cellular processes, including development, differentiation, proliferation, and apoptosis. The previous studies about KLF4 functions mainly focused on its role as a transcription factor, its functions in the cytoplasm are still unknown. In this study, we found that PDGF-BB could prompt the translocation of KLF4 to the cytoplasm through CRM1-mediated nuclear export pathway in vascular smooth muscle cells (VSMCs) and increased the interaction of KLF4 with actin in the cytoplasm. Further study showed that both KLF4 phosphorylation and SUMOylation induced by PDGF-BB participates in regulation of cytoskeletal organization by stabilizing the actin cytoskeleton in VSMCs. In conclusion, these results identify that KLF4 participates in the cytoskeletal organization by stabilizing cytoskeleton in the cytoplasm of VSMCs.

  17. Phosphotyrosine phosphatase inhibitor bisperoxovanadium endows myogenic cells with enhanced muscle stem cell functions via epigenetic modulation of Sca-1 and Pw1 promoters.

    Science.gov (United States)

    Smeriglio, Piera; Alonso-Martin, Sonia; Masciarelli, Silvia; Madaro, Luca; Iosue, Ilaria; Marrocco, Valeria; Relaix, Frédéric; Fazi, Francesco; Marazzi, Giovanna; Sassoon, David A; Bouché, Marina

    2016-04-01

    Understanding the regulation of the stem cell fate is fundamental for designing novel regenerative medicine strategies. Previous studies have suggested that pharmacological treatments with small molecules provide a robust and reversible regulation of the stem cell program. Previously, we showed that treatment with a vanadium compound influences muscle cell fatein vitro In this study, we demonstrate that treatment with the phosphotyrosine phosphatase inhibitor bisperoxovanadium (BpV) drives primary muscle cells to a poised stem cell stage, with enhanced function in muscle regenerationin vivofollowing transplantation into injured muscles. Importantly, BpV-treated cells displayed increased self-renewal potentialin vivoand replenished the niche in both satellite and interstitial cell compartments. Moreover, we found that BpV treatment induces specific activating chromatin modifications at the promoter regions of genes associated with stem cell fate, includingSca-1andPw1 Thus, our findings indicate that BpV resets the cell fate program by specific epigenetic regulations, such that the committed myogenic cell fate is redirected to an earlier progenitor cell fate stage, which leads to an enhanced regenerative stem cell potential.-Smeriglio, P., Alonso-Martin, S., Masciarelli, S., Madaro, L., Iosue, I., Marrocco, V., Relaix, F., Fazi, F., Marazzi, G., Sassoon, D. A., Bouché, M. Phosphotyrosine phosphatase inhibitor bisperoxovanadium endows myogenic cells with enhanced muscle stem cell functionsviaepigenetic modulation of Sca-1 and Pw1 promoters.

  18. Controlled delivery of SDF-1α and IGF-1: CXCR4(+) cell recruitment and functional skeletal muscle recovery.

    Science.gov (United States)

    Rybalko, Viktoriya Y; Pham, Chantal B; Hsieh, Pei-Ling; Hammers, David W; Merscham-Banda, Melissa; Suggs, Laura J; Farrar, Roger P

    2015-11-01

    Therapeutic delivery of regeneration-promoting biological factors directly to the site of injury has demonstrated its efficacy in various injury models. Several reports describe improved tissue regeneration following local injection of tissue specific growth factors, cytokines and chemokines. Evidence exists that combined cytokine/growth factor treatment is superior for optimizing tissue repair by targeting different aspects of the regeneration response. The purpose of this study was to evaluate the therapeutic potential of the controlled delivery of stromal cell-derived factor-1alpha (SDF-1α) alone or in combination with insulin-like growth factor-I (SDF-1α/IGF-I) for the treatment of tourniquet-induced ischemia/reperfusion injury (TK-I/R) of skeletal muscle. We hypothesized that SDF-1α will promote sustained stem cell recruitment to the site of muscle injury, while IGF-I will induce progenitor cell differentiation to effectively restore muscle contractile function after TK-I/R injury while concurrently reducing apoptosis. Utilizing a novel poly-ethylene glycol PEGylated fibrin gel matrix (PEG-Fib), we incorporated SDF-1α alone (PEG-Fib/SDF-1α) or in combination with IGF-I (PEG-Fib/SDF-1α/IGF-I) for controlled release at the site of acute muscle injury. Despite enhanced cell recruitment and revascularization of the regenerating muscle after SDF-1α treatment, functional analysis showed no benefit from PEG-Fib/SDF-1α therapy, while dual delivery of PEG-Fib/SDF-1α/IGF-I resulted in IGF-I-mediated improvement of maximal force recovery and SDF-1α-driven in vivo neovasculogenesis. Histological data supported functional data, as well as highlighted the important differences in the regeneration process among treatment groups. This study provides evidence that while revascularization may be necessary for maximizing muscle force recovery, without modulation of other effects of inflammation it is insufficient.

  19. Role of Cell-Cell bond for the viability and the function of vascular smooth muscle cells

    Directory of Open Access Journals (Sweden)

    M. Mura

    2010-01-01

    Full Text Available Vascular smooth muscle cell (VSMC viability and homeostasis is regulated by cell-matrix and cell-cell contact: disruption of these interactions are responsible of a switch from a mature to a high proliferative phenotype. VSMCs migration, rate of growth and apoptosis, and the extent of their extracellular matrix (ECM deposition can be also modulated by proatherogenic peptides. Among them, ATII induces the transactivation of IGF I R, which, together with the binding protein IGFBP3, represents a determinant of cell survival, growth and proliferation. Aim of our in vitro study was to verify the role of elective cell-cell bond in moulating the response to ATII. Thus, we evaluated viability, proliferation, IGFIR, IGFBP3 expression and the long term survival and production of ECM in a provisional tissue. A7r5 cell-line was used in adherent cultures or incubated in agarose-coated culture plates to inhibit cell-matrix interactions. Cells, treated or not with ATII 100 nM, were evaluated for apoptosis rate, cell cycle, IGFIR and IGFBP3 protei expression. Fibrin provisional tissue was developed polymerizing a fibrin solution. cantaining A7r5 cells with thrombin. Histological stainings for ECM components were performed on sections of prvisional tissue. An exclusive cell-cell contact resulted to monolayer cell cultures. ATII did not affect the cell survival in both culture conditions, but promoted a 10% decrease in "S" phase and an increases IGFIR expression only in adherent cells. while suspended cell aggregates were resistant to ATII administration; IGFBP3 was reduced both in ATII treated adherent cells and in floating clustered cells, irrespective of the treatmentn. VSMC conditioning in agarose-coated plates before seeding in fibrin provisional matrix reduced, but not abolished, the cell ability to colonize the clot and to produce ECM. This study demonstrates that the elective cell-cell contact induces a quiescent status in cells lacking of cell

  20. 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.

  1. Bivalirudin inhibits periprocedural platelet function and tissue factor expression of human smooth muscle cells.

    Science.gov (United States)

    Pepke, Wojciech; Eisenreich, Andreas; Jaster, Markus; Ayral, Yunus; Bobbert, Peter; Mayer, Alexander; Schultheiss, Heinz-Peter; Rauch, Ursula

    2013-04-01

    A major concern of stent implantation after percutaneous coronary intervention (PCI) is acute stent thrombosis. Effective inhibition of periprocedural platelet function in patients with coronary artery disease (CAD) leads to an improved outcome. In this study, we examined the periprocedural platelet reactivity after administrating bivalirudin during PCI compared to unfractionated heparin (UFH) administration. Further, the effect of bivalirudin on induced tissue factor (TF) expression in smooth muscle cells (SMC) was determined. Patients with CAD (n = 58) and double antithrombotic medication were treated intraprocedural with UFH (n = 30) or bivalirudin (n = 28). Platelet activation markers were flow cytometrically measured before and after stenting. The expression of TF in SMC was determined by real-time PCR and Western blotting. The thrombogenicity of platelet-derived microparticles and SMC was assessed via a TF activity assay. Bivalirudin significantly diminished the agonist-induced platelet reactivity post-PCI. Compared to UFH treatment, the adenosine diphosphate (ADP) and thrombin receptor-activating peptide (TRAP)-induced thrombospondin expression post-PCI was reduced when bivalirudin was administrated during intervention. In contrast to UFH, bivalirudin reduced the P-selectin expression of unstimulated and ADP-induced platelets post-PCI. Moreover, bivalirudin inhibited the thrombin-, but not FVIIa- or FVIIa/FX-induced TF expression and pro-coagulant TF activity of SMC. Moreover, bivalirudin reduced the TF activity of platelet-derived microparticles postinduction with TRAP or ADP. Bivalirudin is better than UFH in reducing periprocedural platelet activation. Moreover, thrombin-induced TF expression is inhibited by bivalirudin. Thus, bivalirudin seems to be a better anticoagulant during PCI than UFH. © 2011 Blackwell Publishing Ltd.

  2. Treatment of human muscle cells with popular dietary supplements increase mitochondrial function and metabolic rate

    Directory of Open Access Journals (Sweden)

    Vaughan Roger A

    2012-11-01

    Full Text Available Abstract Background Obesity is a common pathology with increasing incidence, and is associated with increased mortality and healthcare costs. Several treatment options for obesity are currently available ranging from behavioral modifications to pharmaceutical agents. Many popular dietary supplements claim to enhance weight loss by acting as metabolic stimulators, however direct tests of their effect on metabolism have not been performed. Purpose This work identified the effects popular dietary supplements on metabolic rate and mitochondrial biosynthesis in human skeletal muscle cells. Methods Human rhabdomyosarcoma cells were treated with popular dietary supplements at varied doses for 24 hours. Peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α, an important stimulator of mitochondrial biosynthesis, was quantified using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR. Mitochondrial content was measured using flow cytometry confirmed with confocal microscopy. Glycolytic metabolism was quantified by measuring extracellular acidification rate (ECAR and oxidative metabolism was quantified by measuring oxygen consumption rate (OCR. Total relative metabolism was quantified using WST-1 end point assay. Results Treatment of human rhabdomyosarcoma cells with dietary supplements OxyElite Pro (OEP or Cellucore HD (CHD induced PGC-1α leading to significantly increased mitochondrial content. Glycolytic and oxidative capacities were also significantly increased following treatment with OEP or CHD. Conclusion This is the first work to identify metabolic adaptations in muscle cells following treatment with popular dietary supplements including enhanced mitochondrial biosynthesis, and glycolytic, oxidative and total metabolism.

  3. Synergistic effects of matrix nanotopography and stiffness on vascular smooth muscle cell function.

    Science.gov (United States)

    Chaterji, Somali; Kim, Peter; Choe, Seung H; Tsui, Jonathan H; Lam, Christoffer H; Ho, Derek S; Baker, Aaron B; Kim, Deok-Ho

    2014-08-01

    Vascular smooth muscle cells (vSMCs) retain the ability to undergo modulation in their phenotypic continuum, ranging from a mature contractile state to a proliferative, secretory state. vSMC differentiation is modulated by a complex array of microenvironmental cues, which include the biochemical milieu of the cells and the architecture and stiffness of the extracellular matrix. In this study, we demonstrate that by using UV-assisted capillary force lithography (CFL) to engineer a polyurethane substratum of defined nanotopography and stiffness, we can facilitate the differentiation of cultured vSMCs, reduce their inflammatory signature, and potentially promote the optimal functioning of the vSMC contractile and cytoskeletal machinery. Specifically, we found that the combination of medial tissue-like stiffness (11 MPa) and anisotropic nanotopography (ridge width_groove width_ridge height of 800_800_600 nm) resulted in significant upregulation of calponin, desmin, and smoothelin, in addition to the downregulation of intercellular adhesion molecule-1, tissue factor, interleukin-6, and monocyte chemoattractant protein-1. Further, our results allude to the mechanistic role of the RhoA/ROCK pathway and caveolin-1 in altered cellular mechanotransduction pathways via differential matrix nanotopography and stiffness. Notably, the nanopatterning of the stiffer substrata (1.1 GPa) resulted in the significant upregulation of RhoA, ROCK1, and ROCK2. This indicates that nanopatterning an 800_800_600 nm pattern on a stiff substratum may trigger the mechanical plasticity of vSMCs resulting in a hypercontractile vSMC phenotype, as observed in diabetes or hypertension. Given that matrix stiffness is an independent risk factor for cardiovascular disease and that CFL can create different matrix nanotopographic patterns with high pattern fidelity, we are poised to create a combinatorial library of arterial test beds, whether they are healthy, diseased, injured, or aged. Such

  4. Functional expression of smooth muscle-specific ion channels in TGF-β1-treated human adipose-derived mesenchymal stem cells

    OpenAIRE

    Park, Won Sun; Heo, Soon Chul; Jeon, Eun Su; Hong, Da Hye; Son, Youn Kyoung; Ko, Jae-Hong; Kim, Hyoung Kyu; Lee, Sun Young; Kim, Jae Ho; Han, Jin

    2013-01-01

    Human adipose tissue-derived mesenchymal stem cells (hASCs) have the power to differentiate into various cell types including chondrocytes, osteocytes, adipocytes, neurons, cardiomyocytes, and smooth muscle cells. We characterized the functional expression of ion channels after transforming growth factor-β1 (TGF-β1)-induced differentiation of hASCs, providing insights into the differentiation of vascular smooth muscle cells. The treatment of hASCs with TGF-β1 dramatically increased the contra...

  5. Age-related functional changes and susceptibility to eccentric contraction-induced damage in skeletal muscle cell

    Directory of Open Access Journals (Sweden)

    Seung-Jun Choi

    2016-09-01

    Full Text Available Depending upon external loading conditions, skeletal muscles can either shorten, lengthen, or remain at a fixed length as they produce force. Fixed-end or isometric contractions stabilize joints and allow muscles to act as active struts during locomotion. Active muscles dissipate energy when they are lengthened by an external force that exceeds their current force producing capacity. These unaccustomed eccentric activities often lead to muscle weakness, soreness, and inflammation. During aging, the ability to produce force under these conditions is reduced and appears to be due to not only reductions in muscle mass but also to alterations in the basic mechanisms of contraction. These alterations include impairments in the excitation–contraction process, and the action of the cross-bridges. Also, it is well known that age-related skeletal muscle atrophy is characterized by a preferential atrophy of fast fibers, and increased susceptibility to fast muscle fiber when aged muscles are exposed to eccentric contraction followed by the impaired recovery process has been reported. Taken together, the selective loss of fast muscle fiber in aged muscle could be affected by eccentric-induced muscle damage, which has significant implication to identify the etiology of the age-related functional changes. Therefore, in this review the alteration of age-related muscle function and its impact to/of eccentric induced muscle damage and recovery will be addressed in detail.

  6. Montelukast prevents microparticle-induced inflammatory and functional alterations in human bronchial smooth muscle cells.

    Science.gov (United States)

    Fogli, Stefano; Stefanelli, Fabio; Neri, Tommaso; Bardelli, Claudio; Amoruso, Angela; Brunelleschi, Sandra; Celi, Alessandro; Breschi, Maria Cristina

    2013-10-01

    Microparticles (MPs) are membrane fragments that may play a role in the pathogenesis of chronic respiratory diseases. We aimed to investigate whether human monocytes/macrophage-derived MPs could induce a pro-inflammatory phenotype in human bronchial smooth muscle cells (BSMC) and the effect of montelukast in this setting. Experimental methods included isolation of human monocytes/macrophages and generation of monocyte-derived MPs, RT-PCR analysis of gene expression, immunoenzymatic determination of pro-inflammatory factor release, bioluminescent assay of intracellular cAMP levels and electromobility shift assay analysis of NF-κB nuclear translocation. Stimulation of human BSMC with monocyte-derived MPs induced a pro-inflammatory switch in human BSMC by inducing gene expression (COX-2 and IL-8), protein release in the supernatant (PGE2 and IL-8), and heterologous β2-adrenoceptor desensitization. The latter effect was most likely related to autocrine PGE2 since pre-treatment with COX inhibitors restored the ability of salbutamol to induce cAMP synthesis in desensitized cells. Challenge with MPs induced nuclear translocation of NF-κB and selective NF-κB inhibition decreased MP-induced cytokine release in the supernatant. Montelukast treatment prevented IL-8 release and heterologous β2-adrenoceptor desensitization in human BSMC exposed to monocyte-derived MPs by blocking NF-κB nuclear translocation. These findings provide evidence on the role of human monocyte-derived MPs in the airway smooth muscle phenotype switch as a novel potential mechanism in the progression of chronic respiratory diseases and on the protective effects by montelukast in this setting.

  7. Expression pattern and function of tyrosine receptor kinase B isoforms in rat mesenteric arterial smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Otani, Kosuke; Okada, Muneyoshi; Yamawaki, Hideyuki, E-mail: yamawaki@vmas.kitasato-u.ac.jp

    2015-11-27

    Tyrosine receptor kinaseB (TrkB) is a high affinity receptor for brain-derived neurotrophic factor (BDNF). TrkB isoforms involve full length TrkB (TrkB FL) and truncated TrkB type1 (TrkB T1) and type 2 (TrkB T2) in rats. The aim of present study was to explore their expression pattern and function in mesenteric arterial smooth muscle cells (MASMCs). The expression of TrkB isoform protein and mRNA was examined by Western blotting, immunofluorescence and quantitative RT-PCR analyses. Cell proliferation was measured by a bromodeoxyuridine (BrdU) incorporation assay. Cell migration was measured by a Boyden chamber assay. Cell morphology was observed with a phase-contrast microscope. Protein and mRNA expression of BDNF and TrkB isoforms was confirmed in MASMCs. Expression level of TrkB FL was less, while that of TrkB T1 was the highest in MASMCs. Although BDNF increased phosphorylation of ERK, it had no influence on migration and proliferation of MASMCs. TrkB T1 gene knockdown by a RNA interference induced morphological changes and reduced expression level of α-smooth muscle actin (α-SMA) in MASMCs. Similar morphological changes and reduced α-SMA expression were induced in MASMCs by a Rho kinase inhibitor, Y-27632. In conclusion, we for the first time demonstrate that TrkB T1 expressed highly in MASMCs contributes to maintain normal cell morphology possibly via regulation of Rho activity. This study firstly defined expression level of TrkB isoforms and partly revealed their functions in peripheral vascular cells. - Highlights: • BDNF-TrkB axis mediates neurogenesis, growth, differentiation and survival. • Expression pattern and function of TrkB in vascular smooth muscle remain unclear. • Expression of TrkB FL is low, while that of TrkB T1 is the highest. • TrkB T1 contributes to maintain normal morphology possibly via activating Rho.

  8. Transcriptional and functional differences in stem cell populations isolated from Extraocular and Limb muscles

    DEFF Research Database (Denmark)

    Pacheco-Pinedo, Eugenia Cristina; Budak, Murat T; Zeiger, Ulrike

    2008-01-01

    The extraocular muscles (EOMs) are a distinct muscle group that displays an array of unique contractile, structural and regenerative properties. They also have differential sensitivity to certain diseases and are enigmatically spared in Duchenne muscular dystrophy (DMD). The EOMs are so distinct ...

  9. The functional expression of extracellular calcium-sensing receptor in rat pulmonary artery smooth muscle cells

    Directory of Open Access Journals (Sweden)

    Zhang Wei-hua

    2011-02-01

    Full Text Available Abstract Background The extracellular calcium-sensing receptor (CaSR belongs to family C of the G protein coupled receptors. Whether the CaSR is expressed in the pulmonary artery (PA is unknown. Methods The expression and distribution of CaSR were detected by RT-PCR, Western blotting and immunofluorescence. PA tension was detected by the pulmonary arterial ring technique, and the intracellular calcium concentration ([Ca2+]i was detected by a laser-scanning confocal microscope. Results The expressions of CaSR mRNA and protein were found in both rat pulmonary artery smooth muscle cells (PASMCs and PAs. Increased levels of [Ca2+]o (extracellular calcium concentration or Gd3+ (an agonist of CaSR induced an increase of [Ca2+]i and PAs constriction in a concentration-dependent manner. In addition, the above-mentioned effects of Ca2+ and Gd3+ were inhibited by U73122 (specific inhibitor of PLC, 2-APB (specific antagonist of IP3 receptor, and thapsigargin (blocker of sarcoplasmic reticulum calcium ATPase. Conclusions CaSR is expressed in rat PASMCs, and is involved in regulation of PA tension by increasing [Ca2+]i through G-PLC-IP3 pathway.

  10. Muscle Interstitial Cells: A Brief Field Guide to Non-satellite Cell Populations in Skeletal Muscle.

    Science.gov (United States)

    Tedesco, Francesco Saverio; Moyle, Louise A; Perdiguero, Eusebio

    2017-01-01

    Skeletal muscle regeneration is mainly enabled by a population of adult stem cells known as satellite cells. Satellite cells have been shown to be indispensable for adult skeletal muscle repair and regeneration. In the last two decades, other stem/progenitor cell populations resident in the skeletal muscle interstitium have been identified as "collaborators" of satellite cells during regeneration. They also appear to have a key role in replacing skeletal muscle with adipose, fibrous, or bone tissue in pathological conditions. Here, we review the role and known functions of these different interstitial skeletal muscle cell types and discuss their role in skeletal muscle tissue homeostasis, regeneration, and disease, including their therapeutic potential for cell transplantation protocols.

  11. Interaction of human smooth muscle cells with nanofibrous scaffolds: Effect of fiber orientation on cell adhesion, proliferation, and functional gene expression.

    Science.gov (United States)

    Kuppan, Purushothaman; Sethuraman, Swaminathan; Krishnan, Uma Maheswari

    2015-07-01

    Poly(ɛ-caprolactone) (PCL) and PCL-gelatin random and aligned nanofibers with diameters in the range of 200-400 nm were developed through electrospinning. Mechanical properties of aligned PCL and PCL-gelatin nanofibers were compared, and it was found that aligned PCL nanofibers showed significantly higher tensile strength and Young's modulus than the PCL-gelatin nanofiber system (p muscle cells were cultured on the random and aligned PCL-gelatin nanofibers and evaluated for adhesion, orientation, morphology, viability, proliferation and gene expression. Our results demonstrate that PCL-gelatin promotes higher cell adhesion and proliferation than the PCL nanofibers after 3, 7, and 10 days of culture. Aligned topography favored orientation of the cells along their directions and cell stretching was better in aligned nanofibers than the random nanofibers. The upregulation of α-actin, myosin heavy chain, collagen type I, and elastin genes demonstrate good cell-matrix interactions in both random and aligned scaffolds. Therefore, the present study concludes that aligned PCL-gelatin nanofibers could serve as potential scaffolding for culture of smooth muscle cells and may promote functional regeneration of tubular organs. © 2014 Wiley Periodicals, Inc.

  12. Biomimetic control of vascular smooth muscle cell morphology and phenotype for functional tissue-engineered small-diameter blood vessels.

    Science.gov (United States)

    Chan-Park, Mary B; Shen, Jin Ye; Cao, Ye; Xiong, Yun; Liu, Yunxiao; Rayatpisheh, Shahrzad; Kang, Gavin Chun-Wei; Greisler, Howard P

    2009-03-15

    Small-diameter blood vessel substitutes are urgently needed for patients requiring replacements of their coronary and below-the-knee vessels and for better arteriovenous dialysis shunts. Circulatory diseases, especially those arising from atherosclerosis, are the predominant cause of mortality and morbidity in the developed world. Current therapies include the use of autologous vessels or synthetic materials as vessel replacements. The limited availability of healthy vessels for use as bypass grafts and the failure of purely synthetic materials in small-diameter sites necessitate the development of a biological substitute. Tissue engineering is such an approach and has achieved promising results, but reconstruction of a functional vascular tunica media, with circumferentially oriented contractile smooth muscle cells (SMCs) and extracellular matrix, appropriate mechanical properties, and vasoactivity has yet to be demonstrated. This review focuses on strategies to effect the switch of SMC phenotype from synthetic to contractile, which is regarded as crucial for the engineering of a functional vascular media. The synthetic SMC phenotype is desired initially for cell proliferation and tissue remodeling, but the contractile phenotype is then necessary for sufficient vasoactivity and inhibition of neointima formation. The factors governing the switch to a more contractile phenotype with in vitro culture are reviewed.

  13. Proteasomal Inhibition Restores Biological Function of Mis-sense Mutated Dysferlin in Patient-derived Muscle Cells*

    Science.gov (United States)

    Azakir, Bilal A.; Di Fulvio, Sabrina; Kinter, Jochen; Sinnreich, Michael

    2012-01-01

    Dysferlin is a transmembrane protein implicated in surface membrane repair of muscle cells. Mutations in dysferlin cause the progressive muscular dystrophies Miyoshi myopathy, limb girdle muscular dystrophy 2B, and distal anterior compartment myopathy. Dysferlinopathies are inherited in an autosomal recessive manner, and many patients with this disease harbor mis-sense mutations in at least one of their two pathogenic DYSF alleles. These patients have significantly reduced or absent dysferlin levels in skeletal muscle, suggesting that dysferlin encoded by mis-sense alleles is rapidly degraded by the cellular quality control system. We reasoned that mis-sense mutated dysferlin, if salvaged from degradation, might be biologically functional. We used a dysferlin-deficient human myoblast culture harboring the common R555W mis-sense allele and a DYSF-null allele, as well as control human myoblast cultures harboring either two wild-type or two null alleles. We measured dysferlin protein and mRNA levels, resealing kinetics of laser-induced plasmalemmal wounds, myotube formation, and cellular viability after treatment of the human myoblast cultures with the proteasome inhibitors lactacystin or bortezomib (Velcade). We show that endogenous R555W mis-sense mutated dysferlin is degraded by the proteasomal system. Inhibition of the proteasome by lactacystin or Velcade increases the levels of R555W mis-sense mutated dysferlin. This salvaged protein is functional as it restores plasma membrane resealing in patient-derived myoblasts and reverses their deficit in myotube formation. Bortezomib and lactacystin did not cause cellular toxicity at the regimen used. Our results raise the possibility that inhibition of the degradation pathway of mis-sense mutated dysferlin could be used as a therapeutic strategy for patients harboring certain dysferlin mis-sense mutations. PMID:22318734

  14. Proteasomal inhibition restores biological function of mis-sense mutated dysferlin in patient-derived muscle cells.

    Science.gov (United States)

    Azakir, Bilal A; Di Fulvio, Sabrina; Kinter, Jochen; Sinnreich, Michael

    2012-03-23

    Dysferlin is a transmembrane protein implicated in surface membrane repair of muscle cells. Mutations in dysferlin cause the progressive muscular dystrophies Miyoshi myopathy, limb girdle muscular dystrophy 2B, and distal anterior compartment myopathy. Dysferlinopathies are inherited in an autosomal recessive manner, and many patients with this disease harbor mis-sense mutations in at least one of their two pathogenic DYSF alleles. These patients have significantly reduced or absent dysferlin levels in skeletal muscle, suggesting that dysferlin encoded by mis-sense alleles is rapidly degraded by the cellular quality control system. We reasoned that mis-sense mutated dysferlin, if salvaged from degradation, might be biologically functional. We used a dysferlin-deficient human myoblast culture harboring the common R555W mis-sense allele and a DYSF-null allele, as well as control human myoblast cultures harboring either two wild-type or two null alleles. We measured dysferlin protein and mRNA levels, resealing kinetics of laser-induced plasmalemmal wounds, myotube formation, and cellular viability after treatment of the human myoblast cultures with the proteasome inhibitors lactacystin or bortezomib (Velcade). We show that endogenous R555W mis-sense mutated dysferlin is degraded by the proteasomal system. Inhibition of the proteasome by lactacystin or Velcade increases the levels of R555W mis-sense mutated dysferlin. This salvaged protein is functional as it restores plasma membrane resealing in patient-derived myoblasts and reverses their deficit in myotube formation. Bortezomib and lactacystin did not cause cellular toxicity at the regimen used. Our results raise the possibility that inhibition of the degradation pathway of mis-sense mutated dysferlin could be used as a therapeutic strategy for patients harboring certain dysferlin mis-sense mutations.

  15. Different modes of endothelial-smooth muscle cell interaction elicit differential β-catenin phosphorylations and endothelial functions.

    Science.gov (United States)

    Chang, Shun-Fu; Chen, Li-Jing; Lee, Pei-Ling; Lee, Ding-Yu; Chien, Shu; Chiu, Jeng-Jiann

    2014-02-04

    β-Catenin phosphorylation plays important roles in modulating its functions, but the effects of different phosphorylated forms of β-catenin in response to heterocellular interaction are unclear. Here we investigated whether distinct modes of phosphorylation on β-catenin could be triggered through heterocellular interactions between endothelial cells (ECs) and smooth muscle cells (SMCs), and the consequent modulation of EC functions. ECs were cocultured with SMCs to initiate direct contact and paracrine interaction. EC-SMC coculture induced EC β-catenin phosphorylations simultaneously at tyrosine 142 (Tyr142) and serine 45/threonine 41 (Ser45/Thr41) at the cytoplasm/nuclei and the membrane, respectively. Treating ECs with SMC-conditional medium induced β-catenin phosphorylation only at Ser45/Thr41. These findings indicate that different phosphorylation effects of EC-SMC coculture were induced through heterocellular direct contact and paracrine effects, respectively. Using specific blocking peptides, antagonists, and siRNAs, we found that the β-catenin Tyr142-phosphorylation was mediated by connexin 43/Fer and that the β-catenin Ser45/Thr41-phosphorylation was mediated by SMC-released bone morphogenetic proteins through VE-cadherin and bone morphogenetic protein receptor-II/Smad5. Transfecting ECs with β-catenin-Tyr142 or -Ser45 mutants showed that these two phosphorylated forms of β-catenin modulate differential EC function: The Tyr142-phosphorylated β-catenin stimulates vascular cell-adhesion molecule-1 expression to increase EC-monocytic adhesion, but the Ser45/Thr41-phosphorylated β-catenin attenuates VE-cadherin-dependent junction structures to increase EC permeability. Our findings provide new insights into the understanding of regulatory complexities of distinct modes of β-catenin phosphorylations under EC-SMC interactions and suggest that different phosphorylated forms of β-catenin play important roles in modulating vascular pathophysiology

  16. Evaluation of muscle function of the extensor digitorum longus muscle ex vivo and tibialis anterior muscle in situ in mice.

    Science.gov (United States)

    Hakim, Chady H; Wasala, Nalinda B; Duan, Dongsheng

    2013-02-09

    Body movements are mainly provided by mechanical function of skeletal muscle. Skeletal muscle is composed of numerous bundles of myofibers that are sheathed by intramuscular connective tissues. Each myofiber contains many myofibrils that run longitudinally along the length of the myofiber. Myofibrils are the contractile apparatus of muscle and they are composed of repeated contractile units known as sarcomeres. A sarcomere unit contains actin and myosin filaments that are spaced by the Z discs and titin protein. Mechanical function of skeletal muscle is defined by the contractile and passive properties of muscle. The contractile properties are used to characterize the amount of force generated during muscle contraction, time of force generation and time of muscle relaxation. Any factor that affects muscle contraction (such as interaction between actin and myosin filaments, homeostasis of calcium, ATP/ADP ratio, etc.) influences the contractile properties. The passive properties refer to the elastic and viscous properties (stiffness and viscosity) of the muscle in the absence of contraction. These properties are determined by the extracellular and the intracellular structural components (such as titin) and connective tissues (mainly collagen) (1-2). The contractile and passive properties are two inseparable aspects of muscle function. For example, elbow flexion is accomplished by contraction of muscles in the anterior compartment of the upper arm and passive stretch of muscles in the posterior compartment of the upper arm. To truly understand muscle function, both contractile and passive properties should be studied. The contractile and/or passive mechanical properties of muscle are often compromised in muscle diseases. A good example is Duchenne muscular dystrophy (DMD), a severe muscle wasting disease caused by dystrophin deficiency (3). Dystrophin is a cytoskeletal protein that stabilizes the muscle cell membrane (sarcolemma) during muscle contraction (4). In the

  17. 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

  18. Satellite cells: the architects of skeletal muscle.

    Science.gov (United States)

    Chang, Natasha C; Rudnicki, Michael A

    2014-01-01

    The outstanding regenerative capacity of skeletal muscle is attributed to the resident muscle stem cell termed satellite cell. Satellite cells are essential for skeletal muscle regeneration as they ultimately provide the myogenic precursors that rebuild damaged muscle tissue. Satellite cells characteristically are a heterogeneous population of stem cells and committed progenitor cells. Delineation of cellular hierarchy and understanding how lineage fate choices are determined within the satellite cell population will be invaluable for the advancement of muscle regenerative therapies.

  19. Analysis of SM22alpha-deficient mice reveals unanticipated insights into smooth muscle cell differentiation and function.

    Science.gov (United States)

    Zhang, J C; Kim, S; Helmke, B P; Yu, W W; Du, K L; Lu, M M; Strobeck, M; Yu, Q; Parmacek, M S

    2001-02-01

    SM22alpha is a 22-kDa smooth muscle cell (SMC) lineage-restricted protein that physically associates with cytoskeletal actin filament bundles in contractile SMCs. To examine the function of SM22alpha, gene targeting was used to generate SM22alpha-deficient (SM22(-/-LacZ)) mice. The gene targeting strategy employed resulted in insertion of the bacterial lacZ reporter gene at the SM22alpha initiation codon, permitting precise analysis of the temporal and spatial pattern of SM22alpha transcriptional activation in the developing mouse. Northern and Western blot analyses confirmed that the gene targeting strategy resulted in a null mutation. Histological analysis of SM22(+/-LacZ) embryos revealed detectable beta-galactosidase activity in the unturned embryonic day 8.0 embryo in the layer of cells surrounding the paired dorsal aortae concomitant with its expression in the primitive heart tube, cephalic mesenchyme, and yolk sac vasculature. Subsequently, during postnatal development, beta-galactosidase activity was observed exclusively in arterial, venous, and visceral SMCs. SM22alpha-deficient mice are viable and fertile. Their blood pressure and heart rate do not differ significantly from their control SM22alpha(+/-) and SM22alpha(+/+) littermates. The vasculature and SMC-containing tissues of SM22alpha-deficient mice develop normally and appear to be histologically and ultrastructurally similar to those of their control littermates. Taken together, these data demonstrate that SM22alpha is not required for basal homeostatic functions mediated by vascular and visceral SMCs in the developing mouse. These data also suggest that signaling pathways that regulate SMC specification and differentiation from local mesenchyme are activated earlier in the angiogenic program than previously recognized.

  20. Structure and function of the skeletal muscle extracellular matrix.

    Science.gov (United States)

    Gillies, Allison R; Lieber, Richard L

    2011-09-01

    The skeletal muscle extracellular matrix (ECM) plays an important role in muscle fiber force transmission, maintenance, and repair. In both injured and diseased states, ECM adapts dramatically, a property that has clinical manifestations and alters muscle function. Here we review the structure, composition, and mechanical properties of skeletal muscle ECM; describe the cells that contribute to the maintenance of the ECM; and, finally, overview changes that occur with pathology. New scanning electron micrographs of ECM structure are also presented with hypotheses about ECM structure–function relationships. Detailed structure–function relationships of the ECM have yet to be defined and, as a result, we propose areas for future study.

  1. New perspectives of studying gastrointestinal muscle function

    Institute of Scientific and Technical Information of China (English)

    Hans Gregersen; Donghua Liao

    2006-01-01

    The motor function of the gastrointestinal tract has primarily been studied using manometry and radiography,though more indirect tests have also been applied. Manometry and radiography do not provide detailed information about the muscle properties as can be assessed from studies of muscle properties in muscle strips in vitro. In recent years a technique based on impedance planimetric mEasurement of pressure-cross-sectional area relations in a distending bag has proven to provide more detailed information about the muscle function in vivo. This review shows examples of new muscle function analysis such as length-tension diagrams, forcevelocity curves and preload-afterload diagrams.

  2. Functional expression of smooth muscle-specific ion channels in TGF-β(1)-treated human adipose-derived mesenchymal stem cells.

    Science.gov (United States)

    Park, Won Sun; Heo, Soon Chul; Jeon, Eun Su; Hong, Da Hye; Son, Youn Kyoung; Ko, Jae-Hong; Kim, Hyoung Kyu; Lee, Sun Young; Kim, Jae Ho; Han, Jin

    2013-08-15

    Human adipose tissue-derived mesenchymal stem cells (hASCs) have the power to differentiate into various cell types including chondrocytes, osteocytes, adipocytes, neurons, cardiomyocytes, and smooth muscle cells. We characterized the functional expression of ion channels after transforming growth factor-β1 (TGF-β1)-induced differentiation of hASCs, providing insights into the differentiation of vascular smooth muscle cells. The treatment of hASCs with TGF-β1 dramatically increased the contraction of a collagen-gel lattice and the expression levels of specific genes for smooth muscle including α-smooth muscle actin, calponin, smooth mucle-myosin heavy chain, smoothelin-B, myocardin, and h-caldesmon. We observed Ca(2+), big-conductance Ca(2+)-activated K(+) (BKCa), and voltage-dependent K(+) (Kv) currents in TGF-β1-induced, differentiated hASCs and not in undifferentiated hASCs. The currents share the characteristics of vascular smooth muscle cells (SMCs). RT-PCR and Western blotting revealed that the L-type (Cav1.2) and T-type (Cav3.1, 3.2, and 3.3), known to be expressed in vascular SMCs, dramatically increased along with the Cavβ1 and Cavβ3 subtypes in TGF-β1-induced, differentiated hASCs. Although the expression-level changes of the β-subtype BKCa channels varied, the major α-subtype BKCa channel (KCa1.1) clearly increased in the TGF-β1-induced, differentiated hASCs. Most of the Kv subtypes, also known to be expressed in vascular SMCs, dramatically increased in the TGF-β1-induced, differentiated hASCs. Our results suggest that TGF-β1 induces the increased expression of vascular SMC-like ion channels and the differentiation of hASCs into contractile vascular SMCs.

  3. Functional expression of smooth muscle-specific ion channels in TGF-β1-treated human adipose-derived mesenchymal stem cells

    Science.gov (United States)

    Park, Won Sun; Heo, Soon Chul; Jeon, Eun Su; Hong, Da Hye; Son, Youn Kyoung; Ko, Jae-Hong; Kim, Hyoung Kyu; Lee, Sun Young; Kim, Jae Ho

    2013-01-01

    Human adipose tissue-derived mesenchymal stem cells (hASCs) have the power to differentiate into various cell types including chondrocytes, osteocytes, adipocytes, neurons, cardiomyocytes, and smooth muscle cells. We characterized the functional expression of ion channels after transforming growth factor-β1 (TGF-β1)-induced differentiation of hASCs, providing insights into the differentiation of vascular smooth muscle cells. The treatment of hASCs with TGF-β1 dramatically increased the contraction of a collagen-gel lattice and the expression levels of specific genes for smooth muscle including α-smooth muscle actin, calponin, smooth mucle-myosin heavy chain, smoothelin-B, myocardin, and h-caldesmon. We observed Ca2+, big-conductance Ca2+-activated K+ (BKCa), and voltage-dependent K+ (Kv) currents in TGF-β1-induced, differentiated hASCs and not in undifferentiated hASCs. The currents share the characteristics of vascular smooth muscle cells (SMCs). RT-PCR and Western blotting revealed that the L-type (Cav1.2) and T-type (Cav3.1, 3.2, and 3.3), known to be expressed in vascular SMCs, dramatically increased along with the Cavβ1 and Cavβ3 subtypes in TGF-β1-induced, differentiated hASCs. Although the expression-level changes of the β-subtype BKCa channels varied, the major α-subtype BKCa channel (KCa1.1) clearly increased in the TGF-β1-induced, differentiated hASCs. Most of the Kv subtypes, also known to be expressed in vascular SMCs, dramatically increased in the TGF-β1-induced, differentiated hASCs. Our results suggest that TGF-β1 induces the increased expression of vascular SMC-like ion channels and the differentiation of hASCs into contractile vascular SMCs. PMID:23761629

  4. Satellite cells from dystrophic muscle retain regenerative capacity

    Directory of Open Access Journals (Sweden)

    Luisa Boldrin

    2015-01-01

    Full Text Available Duchenne muscular dystrophy is an inherited disorder that is characterized by progressive skeletal muscle weakness and wasting, with a failure of muscle maintenance/repair mediated by satellite cells (muscle stem cells. The function of skeletal muscle stem cells resident in dystrophic muscle may be perturbed by being in an increasing pathogenic environment, coupled with constant demands for repairing muscle. To investigate the contribution of satellite cell exhaustion to this process, we tested the functionality of satellite cells isolated from the mdx mouse model of Duchenne muscular dystrophy. We found that satellite cells derived from young mdx mice contributed efficiently to muscle regeneration within our in vivo mouse model. To then test the effects of long-term residence in a dystrophic environment, satellite cells were isolated from aged mdx muscle. Surprisingly, they were as functional as those derived from young or aged wild type donors. Removing satellite cells from a dystrophic milieu reveals that their regenerative capacity remains both intact and similar to satellite cells derived from healthy muscle, indicating that the host environment is critical for controlling satellite cell function.

  5. 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

    2017-09-16

    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.

  6. Physical Rehabilitation Improves Muscle Function Following Volumetric Muscle Loss Injury

    Science.gov (United States)

    2014-12-19

    Seene T, Kaasik P: Role of exercise therapy in prevention of decline in aging muscle function : glucocorticoid myopathy and unloading. J Aging Res...Combination of exercise training and diet restriction normalizes limited exercise capacity and impaired skeletal muscle function in diet-induced diabetic mice... exercise . Int J Sports Med 2014, 35(1):19–27. 25. Hourdé C, Joanne P, Medja F, Mougenot N, Jacquet A, Mouisel E, Pannerec A, Hatem S, Butler-Browne G

  7. [Reconstruction of quadriceps femoris muscle function with muscle transfer].

    Science.gov (United States)

    Fansa, H; Meric, C

    2010-08-01

    Femoral nerve palsy, mostly of iatrogen cause, leads to paresis of quadriceps muscle with complete loss of knee extension. Therapeutical options include neurolysis, nerve reconstruction or functional muscle transplantations. Another concept is the transfer of hamstring muscles as described in post polio surgery. We describe our experience of biceps femoris and semitendinosus muscle transfer for reconstruction of knee extension. From 2003 to 2007 seven patients (mean age 43) with complete loss of knee extension after femoral nerve lesion were treated. Nerve palsy was caused by direct lesion, traction, hematoma after collapse, lesion of lumbosacral plexus and an unclear muscle dystrophy. Indication for muscle transfer was due to long standing muscle paresis. All patients received a transfer of biceps femoris and semitendinosus muscle/tendon into the quadriceps tendon. Patients were immobilised in a cast for 6 weeks in extended knee position. Weight bearing started after 8 weeks. Operations went uneventfully. All patients were able to extend the knee postoperatively against gravity and were able to climb stairs without help. 4 Patients had complete knee extension, 2 had a lack of 20 degrees , one of 30 degrees. Daily routine was possible in all cases. No instability of knee joints occurred postoperatively. In a nerve lesion close to the muscle a nerve reconstruction should be aimed. If not performed or with unsuccessful outcome, muscle transfer is a good option to restore function. All recent studies describe good to excellent results with stable knees, allowing the patient to manage daily routine without assistance and to climb stairs up and down. Long term complications such as dislocation of patella or genu recurvatum were not observed in our patients. The latter results as typical complication in polio from weakening knee flexion through biceps femoris transfer, if the gastrocnemius muscle is not forceful enough. However in an isolated femoral nerve lesion this

  8. Differentiation of control and ALS mutant human iPSCs into functional skeletal muscle cells, a tool for the study of neuromuscolar diseases

    Directory of Open Access Journals (Sweden)

    Jessica Lenzi

    2016-07-01

    Full Text Available Amyotrophic Lateral Sclerosis (ALS is a severe and fatal neurodegenerative disease characterized by progressive loss of motoneurons, muscle atrophy and paralysis. Recent evidence suggests that ALS should be considered as a multi-systemic disease, in which several cell types contribute to motoneuron degeneration. In this view, mutations in ALS linked genes in other neural and non-neural cell types may exert non-cell autonomous effects on motoneuron survival and function. Induced Pluripotent Stem Cells (iPSCs have been recently derived from several patients with ALS mutations and it has been shown that they can generate motoneurons in vitro, providing a valuable tool to study ALS. However, the potential of iPSCs could be further valorized by generating other cell types that may be relevant to the pathology. In this paper, by taking advantage of a novel inducible system for MyoD expression, we show that both control iPSCs and iPSCs carrying mutations in ALS genes can generate skeletal muscle cells. We provide evidence that both control and mutant iPSC-derived myotubes are functionally active. This in vitro system will be instrumental to dissect the molecular and cellular pathways impairing the complex motoneuron microenvironment in ALS.

  9. A Long-Gap Peripheral Nerve Injury Therapy Using Human Skeletal Muscle-Derived Stem Cells (Sk-SCs): An Achievement of Significant Morphological, Numerical and Functional Recovery.

    Science.gov (United States)

    Tamaki, Tetsuro; Hirata, Maki; Nakajima, Nobuyuki; Saito, Kosuke; Hashimoto, Hiroyuki; Soeda, Shuichi; Uchiyama, Yoshiyasu; Watanabe, Masahiko

    2016-01-01

    Losses in vital functions of the somatic motor and sensory nervous system are induced by severe long-gap peripheral nerve transection injury. In such cases, autologous nerve grafts are the gold standard treatment, despite the unavoidable sacrifice of other healthy functions, whereas the prognosis is not always favorable. Here, we use human skeletal muscle-derived stem cells (Sk-SCs) to reconstitute the function after long nerve-gap injury. Muscles samples were obtained from the amputated legs from 9 patients following unforeseen accidents. The Sk-SCs were isolated using conditioned collagenase solution, and sorted as CD34+/45- (Sk-34) and CD34-/45-/29+ (Sk-DN/29+) cells. Cells were separately cultured/expanded under optimal conditions for 2 weeks, then injected into the athymic nude mice sciatic nerve long-gap model (7-mm) bridging an acellular conduit. After 8-12 weeks, active cell engraftment was observed only in the Sk-34 cell transplanted group, showing preferential differentiation into Schwann cells and perineurial/endoneurial cells, as well as formation of the myelin sheath and perineurium/endoneurium surrounding regenerated axons, resulted in 87% of numerical recovery. Differentiation into vascular cell lineage (pericyte and endothelial cells) were also observed. A significant tetanic tension recovery (over 90%) of downstream muscles following electrical stimulation of the sciatic nerve (at upper portion of the gap) was also achieved. In contrast, Sk-DN/29+ cells were completely eliminated during the first 4 weeks, but relatively higher numerical (83% vs. 41% in axon) and functional (80% vs. 60% in tetanus) recovery than control were observed. Noteworthy, significant increase in the formation of vascular networks in the conduit during the early stage (first 2 weeks) of recovery was observed in both groups with the expression of key factors (mRNA and protein levels), suggesting the paracrine effects to angiogenesis. These results suggested that the human Sk

  10. Functional morphology of the thoracolumbar transversospinal muscles.

    Science.gov (United States)

    Cornwall, Jon; Stringer, Mark D; Duxson, Marilyn

    2011-07-15

    STUDY DESIGN. A qualitative and semiquantitative study of the morphology of the human thoracolumbar transversospinal (TSP) muscles. OBJECTIVE. To further define the functional morphology of the thoracolumbar TSP muscles. SUMMARY OF BACKGROUND DATA. The TSP muscle group plays an important role in vertebral function but few studies have rigorously investigated their morphology throughout the thoracolumbar region and details on the location of motor endplates (MEPs) and fiber types are sparse. METHODS. Thoracolumbar TSP muscles were examined by microdissection in five cadavers (seven sides). MEPs were identified using acetylcholinesterase histochemistry in muscles between T5 and S4 unilaterally in two cadavers. The relative proportions of type I and type II skeletal muscle fibers were determined using immunohistochemistry on whole cross sections of every TSP muscle from one side of one cadaver (T5-S4). RESULTS.TSP morphology was homogeneous and consistent throughout the thoracolumbar region. Notable differences to standard descriptions included: (1) consistent attachments between muscles; (2) no discrete cleavage planes between muscles; and (3) attachment sites over the sacrum and to lumbar zygapophysial joints. Previously undescribed small muscles were found attaching to the medial sacrum. All TSP muscles were multipennate, with fibers arranged in parallel having one MEP per muscle fiber. Muscles were highly aerobic (mean proportion of type I fibers 89%), with the proportion of type I fibers decreasing caudally. A significantly greater proportion of type I fibers were found in the midthoracic compared to the low lumbar regions. CONCLUSION. The complex morphology of the TSP muscles indicates that they would be better classified as spinotransverse muscles. They are multipennate, highly aerobic, with fibers organized in parallel, an arrangement lending itself to "fine-tuning" of vertebral movements. Understanding their morphology has implications for investigation

  11. Autophagic regulation of smooth muscle cell biology

    Science.gov (United States)

    Salabei, Joshua K.; Hill, Bradford G.

    2014-01-01

    Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (patho)physiology. PMID:25544597

  12. Autophagic regulation of smooth muscle cell biology

    Directory of Open Access Journals (Sweden)

    Joshua K. Salabei

    2015-04-01

    Full Text Available Autophagy regulates the metabolism, survival, and function of numerous cell types, including those comprising the cardiovascular system. In the vasculature, changes in autophagy have been documented in atherosclerotic and restenotic lesions and in hypertensive vessels. The biology of vascular smooth muscle cells appears particularly sensitive to changes in the autophagic program. Recent evidence indicates that stimuli or stressors evoked during the course of vascular disease can regulate autophagic activity, resulting in modulation of VSMC phenotype and viability. In particular, certain growth factors and cytokines, oxygen tension, and pharmacological drugs have been shown to trigger autophagy in smooth muscle cells. Importantly, each of these stimuli has a redox component, typically associated with changes in the abundance of reactive oxygen, nitrogen, or lipid species. Collective findings support the hypothesis that autophagy plays a critical role in vascular remodeling by regulating smooth muscle cell phenotype transitions and by influencing the cellular response to stress. In this graphical review, we summarize current knowledge on the role of autophagy in the biology of the smooth muscle cell in (pathophysiology.

  13. Satellite Cell Heterogeneity in Skeletal Muscle Homeostasis.

    Science.gov (United States)

    Tierney, Matthew T; Sacco, Alessandra

    2016-06-01

    The cellular turnover required for skeletal muscle maintenance and repair is mediated by resident stem cells, also termed satellite cells. Satellite cells normally reside in a quiescent state, intermittently entering the cell cycle to fuse with neighboring myofibers and replenish the stem cell pool. However, the mechanisms by which satellite cells maintain the precise balance between self-renewal and differentiation necessary for long-term homeostasis remain unclear. Recent work has supported a previously unappreciated heterogeneity in the satellite cell compartment that may underlie the observed variability in cell fate and function. In this review, we examine the work supporting this notion as well as the potential governing principles, developmental origins, and principal determinants of satellite cell heterogeneity.

  14. Gallic acid tailoring surface functionalities of plasma-polymerized allylamine-coated 316L SS to selectively direct vascular endothelial and smooth muscle cell fate for enhanced endothelialization.

    Science.gov (United States)

    Yang, Zhilu; Xiong, Kaiqin; Qi, Pengkai; Yang, Ying; Tu, Qiufen; Wang, Jin; Huang, Nan

    2014-02-26

    The creation of a platform for enhanced vascular endothelia cell (VEC) growth while suppressing vascular smooth muscle cell (VSMC) proliferation offers possibility for advanced coatings of vascular stents. Gallic acid (GA), a chemically unique phenolic acid with important biological functions, presents benefits to the cardiovascular disease therapy because of its superior antioxidant effect and a selectivity to support the growth of ECs more than SMCs. In this study, GA was explored to tailor such a multifunctional stent surface combined with plasma polymerization technique. On the basis of the chemical coupling reaction, GA was bound to an amine-group-rich plasma-polymerized allylamine (PPAam) coating. The GA-functionalized PPAam (GA-PPAam) surface created a favorable microenvironment to obtain high ECs and SMCs selectivity. The GA-PPAam coating showed remarkable enhancement in the adhesion, viability, proliferation, migration, and release of nitric oxide (NO) of human umbilical vein endothelial cells (HUVECs). The GA-PPAam coating also resulted in remarkable inhibition effect on human umbilical artery smooth muscle cell (HUASMC) adhesion and proliferation. These striking findings may provide a guide for designing the new generation of multifunctional vascular devices.

  15. Impact of weightlessness on muscle function

    Science.gov (United States)

    Tischler, M. E.; Slentz, M.

    1995-01-01

    The most studied skeletal muscles which depend on gravity, "antigravity" muscles, are located in the posterior portion of the legs. Antigravity muscles are characterized generally by a different fiber type composition than those which are considered nonpostural. The gravity-dependent function of the antigravity muscles makes them particularly sensitive to weightlessness (unweighting) resulting in a substantial loss of muscle protein, with a relatively greater loss of myofibrillar (structural) proteins. Accordingly alpha-actin mRNA decreases in muscle of rats exposed to microgravity. In the legs, the soleus seems particularly responsive to the lack of weight-bearing associated with space flight. The loss of muscle protein leads to a decreased cross-sectional area of muscle fibers, particularly of the slow-twitch, oxidative (SO) ones compared to fast-twitch glycolytic (FG) or oxidative-glycolytic (FOG) fibers. In some muscles, a shift in fiber composition from SO to FOG has been reported in the adaptation to spaceflight. Changes in muscle composition with spaceflight have been associated with decreased maximal isometric tension (Po) and increased maximal shortening velocity. In terms of fuel metabolism, results varied depending on the pathway considered. Glucose uptake, in the presence of insulin, and activities of glycolytic enzymes are increased by space flight. In contrast, oxidation of fatty acids may be diminished. Oxidation of pyruvate, activity of the citric acid cycle, and ketone metabolism in muscle seem to be unaffected by microgravity.

  16. Impact of weightlessness on muscle function

    Science.gov (United States)

    Tischler, M. E.; Slentz, M.

    1995-01-01

    The most studied skeletal muscles which depend on gravity, "antigravity" muscles, are located in the posterior portion of the legs. Antigravity muscles are characterized generally by a different fiber type composition than those which are considered nonpostural. The gravity-dependent function of the antigravity muscles makes them particularly sensitive to weightlessness (unweighting) resulting in a substantial loss of muscle protein, with a relatively greater loss of myofibrillar (structural) proteins. Accordingly alpha-actin mRNA decreases in muscle of rats exposed to microgravity. In the legs, the soleus seems particularly responsive to the lack of weight-bearing associated with space flight. The loss of muscle protein leads to a decreased cross-sectional area of muscle fibers, particularly of the slow-twitch, oxidative (SO) ones compared to fast-twitch glycolytic (FG) or oxidative-glycolytic (FOG) fibers. In some muscles, a shift in fiber composition from SO to FOG has been reported in the adaptation to spaceflight. Changes in muscle composition with spaceflight have been associated with decreased maximal isometric tension (Po) and increased maximal shortening velocity. In terms of fuel metabolism, results varied depending on the pathway considered. Glucose uptake, in the presence of insulin, and activities of glycolytic enzymes are increased by space flight. In contrast, oxidation of fatty acids may be diminished. Oxidation of pyruvate, activity of the citric acid cycle, and ketone metabolism in muscle seem to be unaffected by microgravity.

  17. Function and role of voltage-gated sodium channel NaV1.7 expressed in aortic smooth muscle cells.

    Science.gov (United States)

    Meguro, Kentaro; Iida, Haruko; Takano, Haruhito; Morita, Toshihiro; Sata, Masataka; Nagai, Ryozo; Nakajima, Toshiaki

    2009-01-01

    Voltage-gated Na(+) channel currents (I(Na)) are expressed in several types of smooth muscle cells. The purpose of this study was to evaluate the expression of I(Na), its functional role, pathophysiology in cultured human (hASMCs) and rabbit aortic smooth muscle cells (rASMCs), and its association with vascular intimal hyperplasia. In whole cell voltage clamp, I(Na) was observed at potential positive to -40 mV, was blocked by tetrodotoxin (TTX), and replacing extracellular Na(+) with N-methyl-d-glucamine in cultured hASMCs. In contrast to native aorta, cultured hASMCs strongly expressed SCN9A encoding Na(V)1.7, as determined by quantitative RT-PCR. I(Na) was abolished by the treatment with SCN9A small-interfering (si)RNA (P SCN9A siRNA significantly inhibited cell migration (P SCN9A in cultured rASMCs and aorta 48 h after balloon injury but not in native aorta. In conclusion, these studies show that I(Na) is expressed in cultured and diseased conditions but not in normal aorta. The Na(V)1.7 plays an important role in cell migration, endocytosis, and secretion. Na(V)1.7 is also expressed in aorta after balloon injury, suggesting a potential role for Na(V)1.7 in the progression of intimal hyperplasia.

  18. Interactions between muscle stem cells, mesenchymal-derived cells and immune cells in muscle homeostasis, regeneration and disease.

    Science.gov (United States)

    Farup, J; Madaro, L; Puri, P L; Mikkelsen, U R

    2015-07-23

    Recent evidence has revealed the importance of reciprocal functional interactions between different types of mononuclear cells in coordinating the repair of injured muscles. In particular, signals released from the inflammatory infiltrate and from mesenchymal interstitial cells (also known as fibro-adipogenic progenitors (FAPs)) appear to instruct muscle stem cells (satellite cells) to break quiescence, proliferate and differentiate. Interestingly, conditions that compromise the functional integrity of this network can bias muscle repair toward pathological outcomes that are typically observed in chronic muscular disorders, that is, fibrotic and fatty muscle degeneration as well as myofiber atrophy. In this review, we will summarize the current knowledge on the regulation of this network in physiological and pathological conditions, and anticipate the potential contribution of its cellular components to relatively unexplored conditions, such as aging and physical exercise.

  19. The cardiac sodium current Na(v)1.5 is functionally expressed in rabbit bronchial smooth muscle cells.

    Science.gov (United States)

    Bradley, E; Webb, T I; Hollywood, M A; Sergeant, G P; McHale, N G; Thornbury, K D

    2013-08-15

    A collagenase-proteinase mixture was used to isolate airway smooth muscle cells (ASMC) from rabbit bronchi, and membrane currents were recorded using the whole cell patch-clamp technique. Stepping from -100 mV to a test potential of -40 mV evoked a fast voltage-dependent Na(+) current, sometimes with an amplitude of several nanoamperes. The current disappeared within 15 min of exposure to papain + DTT (n = 6). Comparison of the current in ASMC with current mediated by NaV1.5 α-subunits expressed in human embryonic kidney cells revealed similar voltage dependences of activation (V1/2 = -42 mV for NaV1.5) and sensitivities to TTX (IC50 = 1.1 and 1.2 μM for ASMC and NaV1.5, respectively). The current in ASMC was also blocked by lidocaine (IC50 = 160 μM). Although veratridine, an agonist of voltage-gated Na(+) channels, reduced the peak current by 33%, it slowed inactivation, resulting in a fourfold increase in sustained current (measured at 25 ms after onset). In current-clamp mode, veratridine prolonged evoked action potentials from 37 ± 9 to 1,053 ± 410 ms (n = 8). Primers for NaV1.2-1.9 were used to amplify mRNA from groups of ∼20 isolated ASMC and from whole bronchial tissue by RT-PCR. Transcripts for NaV1.2, NaV1.3, and NaV1.5-1.9 were detected in whole tissue, but only NaV1.2 and NaV1.5 were detected in single cells. We conclude that freshly dispersed rabbit ASMC express a fast voltage-gated Na(+) current that is mediated mainly by the NaV1.5 subtype.

  20. Vitamin D and muscle function.

    Science.gov (United States)

    Dawson-Hughes, Bess

    2017-10-01

    Muscle weakness is a hallmark of severe vitamin D deficiency, but the effect of milder vitamin D deficiency or insufficiency on muscle mass and performance and risk of falling is uncertain. In this presentation, I review the evidence that vitamin D influences muscle mass and performance, balance, and risk of falling in older adults. Special consideration is given to the impact of both the starting 25-hydroxyvitamin D [25(OH)D] level and the dose administered on the clinical response to supplemental vitamin D in older men and women. Based on available evidence, older adults with serum 25(OH)D levels D dose range of 800-1000 IU per day has been effective in many studies; lower doses have generally been ineffective and several doses above this range have increased the risk of falls. In conclusion, older adults with serum 25(OH)D levels D. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Muscle function and swimming in sharks.

    Science.gov (United States)

    Shadwick, R E; Goldbogen, J A

    2012-04-01

    The locomotor system in sharks has been investigated for many decades, starting with the earliest kinematic studies by Sir James Gray in the 1930s. Early work on axial muscle anatomy also included sharks, and the first demonstration of the functional significance of red and white muscle fibre types was made on spinal preparations in sharks. Nevertheless, studies on teleosts dominate the literature on fish swimming. The purpose of this article is to review the current knowledge of muscle function and swimming in sharks, by considering their morphological features related to swimming, the anatomy and physiology of the axial musculature, kinematics and muscle dynamics, and special features of warm-bodied lamnids. In addition, new data are presented on muscle activation in fast-starts. Finally, recent developments in tracking technology that provide insights into shark swimming performance in their natural environment are highlighted.

  2. 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.

  3. Independent and Combined Association of Muscle Strength and Cardiorespiratory Fitness in Youth With Insulin Resistance and β-Cell Function in Young Adulthood

    DEFF Research Database (Denmark)

    Grøntved, Anders; Ried-Larsen, Mathias; Ekelund, Ulf

    2013-01-01

    OBJECTIVETo examine the independent and combined association of isometric muscle strength of the abdomen and back and cardiorespiratory fitness (CRF) in youth with indices of glucose metabolism in young adulthood among boys and girls from the European Youth Heart Study.RESEARCH DESIGN AND METHODSWe.......RESULTSFor each 1-SD difference in isometric muscle strength (0.16 N/kg) in youth, fasting insulin, HOMA-IR, and HOMA-B in young adulthood changed with -11.3% (95% CI, -17.0 to -5.2), -12.2% (-18.2 to -5.7), and -8.9% (-14.4 to -3.0), respectively, in young adulthood after adjustment for CRF and personal...... ergometer test. Insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR]) and β-cell function (homeostasis model assessment of β-cell function [HOMA-B]) were estimated from fasting serum insulin and glucose that were obtained in youth and at follow-up in young adulthood...

  4. Noninvasive analysis of human neck muscle function

    Science.gov (United States)

    Conley, M. S.; Meyer, R. A.; Bloomberg, J. J.; Feeback, D. L.; Dudley, G. A.

    1995-01-01

    STUDY DESIGN. Muscle use evoked by exercise was determined by quantifying shifts in signal relaxation times of T2-weighted magnetic resonance images. Images were collected at rest and after exercise at each of two intensities (moderate and intense) for each of four head movements: 1) extension, 2) flexion, 3) rotation, and 4) lateral flexion. OBJECTIVE. This study examined the intensity and pattern of neck muscle use evoked by various movements of the head. The results will help elucidate the pathophysiology, and thus methods for treating disorders of the cervical musculoskeletal system. SUMMARY OF BACKGROUND DATA. Exercise-induced contrast shifts in T2 has been shown to indicate muscle use during the activity. The noninvasive nature of magnetic resonance imaging appears to make it an ideal approach for studying the function of the complex neuromuscular system of the neck. METHODS. The extent of T2 increase was examined to gauge how intensely nine different neck muscles or muscle pairs were used in seven subjects. The absolute and relative cross-sectional area of muscle showing a shift in signal relaxation was assessed to infer the pattern of use among and within individual neck muscles or muscle pairs. RESULTS. Signal relaxation increased with exercise intensity for each head movement. The absolute and relative cross-sectional area of muscle showing a shift in signal relaxation also increased with exercise load. Neck muscles or muscle pairs extensively used to perform each head movement were: extension--semispinalis capitis and cervicis and splenius capitis; flexion--sternocleidomastoid and longus capitis and colli; rotation--splenius capitis, levator scapulae, scalenus, semispinalis capitis ipsilateral to the rotation, and sternocleidomastoid contralateral; and lateral flexion--sternocleidomastoid CONCLUSION. The results of this study, in part, agree with the purported functions of neck muscles derived from anatomic location. This also was true for the few

  5. Collagen VI deficiency reduces muscle pathology, but does not improve muscle function, in the γ-sarcoglycan-null mouse.

    Science.gov (United States)

    de Greef, Jessica C; Hamlyn, Rebecca; Jensen, Braden S; O'Campo Landa, Raul; Levy, Jennifer R; Kobuke, Kazuhiro; Campbell, Kevin P

    2016-04-01

    Muscular dystrophy is characterized by progressive skeletal muscle weakness and dystrophic muscle exhibits degeneration and regeneration of muscle cells, inflammation and fibrosis. Skeletal muscle fibrosis is an excessive deposition of components of the extracellular matrix including an accumulation of Collagen VI. We hypothesized that a reduction of Collagen VI in a muscular dystrophy model that presents with fibrosis would result in reduced muscle pathology and improved muscle function. To test this hypothesis, we crossed γ-sarcoglycan-null mice, a model of limb-girdle muscular dystrophy type 2C, with a Col6a2-deficient mouse model. We found that the resulting γ-sarcoglycan-null/Col6a2Δex5 mice indeed exhibit reduced muscle pathology compared with γ-sarcoglycan-null mice. Specifically, fewer muscle fibers are degenerating, fiber size varies less, Evans blue dye uptake is reduced and serum creatine kinase levels are lower. Surprisingly, in spite of this reduction in muscle pathology, muscle function is not significantly improved. In fact, grip strength and maximum isometric tetanic force are even lower in γ-sarcoglycan-null/Col6a2Δex5 mice than in γ-sarcoglycan-null mice. In conclusion, our results reveal that Collagen VI-mediated fibrosis contributes to skeletal muscle pathology in γ-sarcoglycan-null mice. Importantly, however, our data also demonstrate that a reduction in skeletal muscle pathology does not necessarily lead to an improvement of skeletal muscle function, and this should be considered in future translational studies.

  6. Notch Signaling in Vascular Smooth Muscle Cells.

    Science.gov (United States)

    Baeten, J T; Lilly, B

    2017-01-01

    The Notch signaling pathway is a highly conserved pathway involved in cell fate determination in embryonic development and also functions in the regulation of physiological processes in several systems. It plays an especially important role in vascular development and physiology by influencing angiogenesis, vessel patterning, arterial/venous specification, and vascular smooth muscle biology. Aberrant or dysregulated Notch signaling is the cause of or a contributing factor to many vascular disorders, including inherited vascular diseases, such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, associated with degeneration of the smooth muscle layer in cerebral arteries. Like most signaling pathways, the Notch signaling axis is influenced by complex interactions with mediators of other signaling pathways. This complexity is also compounded by different members of the Notch family having both overlapping and unique functions. Thus, it is vital to fully understand the roles and interactions of each Notch family member in order to effectively and specifically target their exact contributions to vascular disease. In this chapter, we will review the Notch signaling pathway in vascular smooth muscle cells as it relates to vascular development and human disease.

  7. Smooth muscle actin and myosin expression in cultured airway smooth muscle cells.

    Science.gov (United States)

    Wong, J Z; Woodcock-Mitchell, J; Mitchell, J; Rippetoe, P; White, S; Absher, M; Baldor, L; Evans, J; McHugh, K M; Low, R B

    1998-05-01

    In this study, the expression of smooth muscle actin and myosin was examined in cultures of rat tracheal smooth muscle cells. Protein and mRNA analyses demonstrated that these cells express alpha- and gamma-smooth muscle actin and smooth muscle myosin and nonmuscle myosin-B heavy chains. The expression of the smooth muscle specific actin and myosin isoforms was regulated in the same direction when growth conditions were changed. Thus, at confluency in 1 or 10% serum-containing medium as well as for low-density cells (50-60% confluent) deprived of serum, the expression of the smooth muscle forms of actin and myosin was relatively high. Conversely, in rapidly proliferating cultures at low density in 10% serum, smooth muscle contractile protein expression was low. The expression of nonmuscle myosin-B mRNA and protein was more stable and was upregulated only to a small degree in growing cells. Our results provide new insight into the molecular basis of differentiation and contractile function in airway smooth muscle cells.

  8. 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

    2011-09-01

    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, Ca(2+) 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.

  9. 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

  10. EVALUATION OF THE FUNCTIONAL PROPERTIES OF HUMAN ENDOTHELIAL AND SMOOTH MUSCLE CELLS AFTER SEEDING ON THE SURFACE OF NATURAL AND SYNTHETIC MATERIALS

    Directory of Open Access Journals (Sweden)

    Sh. B. Saaya

    2016-01-01

    Full Text Available At present, vascular surgery using small diameter synthetic grafts is associated with a higher incidence of complications (thrombosis, restenosis, intimal hyperplasia than in operations using autologous vessels. However, the occurrence of concomitant pathology, reoperations and multifocal vascular disease limit the use of autologous vein and arteries. The important factor providing a long-term patency is the presence of vascular cells, which produce biologically active substance and provide mechanical properties. Aim. Selection of the optimal scaffold for creating cell-seeded tissue-engineering vessels. Materials and methods. Endothelial (EC and smooth muscle cells (SMC derived from human myocardium were seeded on different surfaces: decellularized homoarteriа, хenopericardium, polytetrafl uoroethylene (PTFE, polyethylene terephthalate (PET, polycaprolactone (PCL and polylactide-co-glycolide (PLGA. Results. Synthetic biodegradable materials polycaprolactone and polylactide-co-glycolide provide cell adhesion. The cells cultured on the polycaprolactone and polylactide-coglycolide scaffolds retain their functional properties: viability and proliferative properties, maintain specifi c endothelial antigens and synthesis of extracellular matrix. Conclusion. Synthetic biodegradable polycaprolactone and polylactide-co-glycolide electrospun scaffolds can be used for creation of cell-fi lled vascular prostheses. 

  11. 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.

  12. Craniomandibular disorders and masticatory muscle function.

    Science.gov (United States)

    Bakke, M; Möller, E

    1992-02-01

    The heading craniomandibular disorders covers a wide range of abnormal and pathologic conditions accompanied by orofacial pain and impaired mandibular function, the masticatory muscles and the temporomandibular joints being the structures most frequently involved. Prevalences of severe craniomandibular disorders accompanied by headache and facial pain urgently in need of treatment are 1-2% in children, about 5% in adolescents, and 5-15% in adults, with higher values in women than in men. With respect to physiology and ergonomics, masticatory muscles are comparable to other human skeletal muscles, e.g. of shoulder, neck and lower back. Therefore these muscles share pathogenesis, symptoms and signs of muscular disorders caused by prolonged, low-level static contractions or intermittent isometric contractions at higher levels. Since the same elements of performance in the masticatory muscles are influenced by occlusal factors, they link the development of muscular fatigue, discomfort and pain to the dental occlusion. Furthermore, changes of the occlusal surfaces, e.g. due to dental treatment, may influence the performance of the masticatory muscles, and consequently interfere with local muscular function.

  13. 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.

  14. Isolation, characterization, and molecular regulation of muscle stem cells

    Directory of Open Access Journals (Sweden)

    So-ichiro eFukada

    2013-11-01

    Full Text Available keletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal muscle biology. Many studies have demonstrated proteins expressed by satellite cells, including Pax7, M-cadherin, Cxcr4, syndecan3/4, and c-met. To further characterize satellite cells, we established a method to directly isolate satellite cells using a monoclonal antibody, SM/C-2.6. Using SM/C-2.6 and microarrays, we measured the genes expressed in quiescent satellite cells and demonstrated that Hesr3 may complement Hesr1 in generating quiescent satellite cells. Although Hesr1- or Hesr3-single knockout mice show a normal skeletal muscle phenotype, including satellite cells, Hesr1/Hesr3-double knockout mice show a gradual decrease in the number of satellite cells and increase in regenerative defects dependent on satellite cell numbers. We also observed that a mouse’s genetic background affects the regenerative capacity of its skeletal muscle and have established a line of DBA/2-background mdx mice that has a much more severe phenotype than the frequently used C57BL/10-mdx mice. The phenotype of DBA/2-mdx mice also seems to depend on the function of satellite cells. In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results. The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized. In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

  15. Virgin birth: engineered heart muscle from parthenogenetic stem cells.

    Science.gov (United States)

    McSweeney, Sara J; Schneider, Michael D

    2013-03-01

    Cardiac muscle restitution, or true regeneration, is an unmet need in the treatment of myocardial infarction (MI), prompting a decade of study with stem cells of many kinds. Among key obstacles to effective cardiac cell grafting are the cost of autologous stem cell-derived cardiomyocytes, the ethical implications of using embryonic stem cell (ESC) products, immunological barriers to allogeneic cells, functional maturation beyond just the correct lineage decision, and the lack of durable engraftment. In this issue of the JCI, Didié and colleagues show that cardiomyocytes made from parthenogenetic stem cells (PSCs) and deployed as engineered heart muscle (EHM) may overcome all of these formidable barriers.

  16. Pharmacological evidence that potentiation of plasmalemmal Ca(2+)-extrusion is functionally coupled to inhibition of SR Ca(2+)-ATPases in vascular smooth muscle cells.

    Science.gov (United States)

    Zhang, Wen-Bo; Kwan, Chiu-Yin

    2016-04-01

    Cyclopiazonic acid (CPA), a specific inhibitor of sarcoplasmic reticulum (SR) Ca(2+)-ATPases, causes slowly developing and subsequently diminishing characteristic contractions in vascular smooth muscle, and the second application of CPA has incompletely repeatable effects, depending on the vessel type. The objective of the present study was to examine the mechanisms underlying the significant decrease of CPA-induced contractions upon the second application. A pharmacological intervention of Ca(2+) extrusion process as a strategy was performed to modulate vasoconstrictor effects of CPA in rat aortic ring preparations. CPA-induced contractions, expressed as percentages of the contractions induced by KCl (80 mM), were significantly decreased from 44.1 ± 5.7 to 7.6 ± 1.8 % (P Ca(2+) exchangers, but not of KBR7943, an inhibitor of the reverse mode of Na(+)/Ca(2+) exchangers. Our findings indicate that CPA by inducing a transient rise in cytosolic Ca(2+) level causes a long-lasting upregulation of plasma membrane (PM) Ca(2+) extruders and thus leads to a diminished contraction upon its second application in blood vessels. This suggests that there is a functional coupling between PM Ca(2+) extruders and SR Ca(2+)-ATPases in rat aortic smooth muscle cells.

  17. Neuromuscular electrical stimulation for skeletal muscle function.

    Science.gov (United States)

    Doucet, Barbara M; Lam, Amy; Griffin, Lisa

    2012-06-01

    Lack of neural innervation due to neurological damage renders muscle unable to produce force. Use of electrical stimulation is a medium in which investigators have tried to find a way to restore movement and the ability to perform activities of daily living. Different methods of applying electrical current to modify neuromuscular activity are electrical stimulation (ES), neuromuscular electrical stimulation (NMES), transcutaneous electrical nerve stimulation (TENS), and functional electrical stimulation (FES). This review covers the aspects of electrical stimulation used for rehabilitation and functional purposes. Discussed are the various parameters of electrical stimulation, including frequency, pulse width/duration, duty cycle, intensity/amplitude, ramp time, pulse pattern, program duration, program frequency, and muscle group activated, and how they affect fatigue in the stimulated muscle.

  18. Rejuvenation of the muscle stem cell population restores strength to injured aged muscles.

    Science.gov (United States)

    Cosgrove, Benjamin D; Gilbert, Penney M; Porpiglia, Ermelinda; Mourkioti, Foteini; Lee, Steven P; Corbel, Stephane Y; Llewellyn, Michael E; Delp, Scott L; Blau, Helen M

    2014-03-01

    The elderly often suffer from progressive muscle weakness and regenerative failure. We demonstrate that muscle regeneration is impaired with aging owing in part to a cell-autonomous functional decline in skeletal muscle stem cells (MuSCs). Two-thirds of MuSCs from aged mice are intrinsically defective relative to MuSCs from young mice, with reduced capacity to repair myofibers and repopulate the stem cell reservoir in vivo following transplantation. This deficiency is correlated with a higher incidence of cells that express senescence markers and is due to elevated activity of the p38α and p38β mitogen-activated kinase pathway. We show that these limitations cannot be overcome by transplantation into the microenvironment of young recipient muscles. In contrast, subjecting the MuSC population from aged mice to transient inhibition of p38α and p38β in conjunction with culture on soft hydrogel substrates rapidly expands the residual functional MuSC population from aged mice, rejuvenating its potential for regeneration and serial transplantation as well as strengthening of damaged muscles of aged mice. These findings reveal a synergy between biophysical and biochemical cues that provides a paradigm for a localized autologous muscle stem cell therapy for the elderly.

  19. 38 CFR 4.78 - Muscle function.

    Science.gov (United States)

    2010-07-01

    ... must chart the areas of diplopia and include the plotted chart with the examination report. (b) Evaluation of muscle function. (1) An evaluation for diplopia will be assigned to only one eye. When a claimant has both diplopia and decreased visual acuity or visual field defect, assign a level of...

  20. Abdominal muscle function and incisional hernia

    DEFF Research Database (Denmark)

    Jensen, K K; Kjaer, M; Jorgensen, L N

    2014-01-01

    of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair. METHODS: The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion. RESULTS: A total of seven...

  1. Agonistic Anti-PDGF Receptor Autoantibodies from Patients with Systemic Sclerosis Impact Human Pulmonary Artery Smooth Muscle Cells Function In Vitro

    Science.gov (United States)

    Svegliati, Silvia; Amico, Donatella; Spadoni, Tatiana; Fischetti, Colomba; Finke, Doreen; Moroncini, Gianluca; Paolini, Chiara; Tonnini, Cecilia; Grieco, Antonella; Rovinelli, Marina; Gabrielli, Armando

    2017-01-01

    One of the earliest events in the pathogenesis of systemic sclerosis (SSc) is microvasculature damage with intimal hyperplasia and accumulation of cells expressing PDGF receptor. Stimulatory autoantibodies targeting PDGF receptor have been detected in SSc patients and demonstrated to induce fibrosis in vivo and convert in vitro normal fibroblasts into SSc-like cells. Since there is no evidence of the role of anti-PDGF receptor autoantibodies in the pathogenesis of SSc vascular lesions, we investigated the biologic effect of agonistic anti-PDGF receptor autoantibodies from SSc patients on human pulmonary artery smooth muscle cells and the signaling pathways involved. The synthetic (proliferation, migration, and type I collagen gene α1 chain expression) and contractile (smooth muscle-myosin heavy chain and smooth muscle-calponin expression) profiles of human pulmonary artery smooth muscle cells were assessed in vitro after incubation with SSc anti-PDGF receptors stimulatory autoantibodies. The role of reactive oxygen species, NOX isoforms, and mammalian target of rapamycin (mTOR) was investigated. Human pulmonary artery smooth muscle cells acquired a synthetic phenotype characterized by higher growth rate, migratory activity, gene expression of type I collagen α1 chain, and less expression of markers characteristic of the contractile phenotype such as smooth muscle-myosin heavy chain and smooth muscle-calponin when stimulated with PDGF and autoantibodies against PDGF receptor, but not with normal IgG. This phenotypic profile is mediated by increased generation of reactive oxygen species and expression of NOX4 and mTORC1. Our data indicate that agonistic anti-PDGF receptor autoantibodies may contribute to the pathogenesis of SSc intimal hyperplasia. PMID:28228756

  2. Selenoprotein N in skeletal muscle: from diseases to function.

    Science.gov (United States)

    Castets, Perrine; Lescure, Alain; Guicheney, Pascale; Allamand, Valérie

    2012-10-01

    Selenoprotein N (SelN) deficiency causes several inherited neuromuscular disorders collectively termed SEPN1-related myopathies, characterized by early onset, generalized muscle atrophy, and muscle weakness affecting especially axial muscles and leading to spine rigidity, severe scoliosis, and respiratory insufficiency. SelN is ubiquitously expressed and is located in the membrane of the endoplasmic reticulum; however, its function remains elusive. The predominant expression of SelN in human fetal tissues and the embryonic muscle phenotype reported in mutant zebrafish suggest that it is involved in myogenesis. In mice, SelN is also mostly expressed during embryogenesis and especially in the myotome, but no defect was detected in muscle development and growth in the Sepn1 knock-out mouse model. By contrast, we recently demonstrated that SelN is essential for muscle regeneration and satellite cell maintenance in mice and humans, hence opening new avenues regarding the pathomechanism(s) leading to SEPN1-related myopathies. At the cellular level, recent data suggested that SelN participates in oxidative and calcium homeostasis, with a potential role in the regulation of the ryanodine receptor activity. Despite the recent and exciting progress regarding the physiological function(s) of SelN in muscle tissue, the pathogenesis leading to SEPN1-related myopathies remains largely unknown, with several unsolved questions, and no treatment available. In this review, we introduce SelN, its properties and expression pattern in zebrafish, mice, and humans, and we discuss its potential roles in muscle tissue and the ensuing clues for the development of therapeutic options.

  3. 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.

  4. Globular adiponectin induces differentiation and fusion of skeletal muscle cells

    Institute of Scientific and Technical Information of China (English)

    Tania Fiaschi; Domenico Cirelli; Giuseppina Comito; Stefania Gelmini; Giampietro Ramponi; Maria Serio; Paola Chiarugi

    2009-01-01

    The growing interest in skeletal muscle regeneration is associated with the opening of new therapeutic strategies for muscle injury after trauma, as well as several muscular degenerative pathologies, including dystrophies, muscu-lar atrophy, and cachexia. Studies focused on the ability of extracellular factors to promote myogenesis are therefore highly promising. We now report that an adipocyte-derived factor, globular adiponectin (gAd), is able to induce mus-cle gene expression and cell differentiation, gAd, besides its well-known ability to regulate several metabolic func-tions in muscle, including glucose uptake and consumption and fatty acid catabolism, is able to block cell cycle entry of myoblasts, to induce the expression of specific skeletal muscle markers such as myosin heavy chain or eaveolin-3, as well as to provoke cell fusion into multinucleated syneytia and, finally, muscle fibre formation, gAd exerts its pro-differentiative activity through redox-dependent activation of p38, Akt and 5'-AMP-activated protein kinase path-ways. Interestingly, differentiating myoblasts are autocrine for adiponectiu, and the mimicking of pro-inflammatory settings or exposure to oxidative stress strongly increases the production of the hormone from differentiating cells. These data suggest a novel function of adiponectin, directly coordinating the myogenic differentiation program and serving an autocrine function during skeletal myogenesis.

  5. Cell-Surface Protein Profiling Identifies Distinctive Markers of Progenitor Cells in Human Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Akiyoshi Uezumi

    2016-08-01

    Full Text Available Skeletal muscle contains two distinct stem/progenitor populations. One is the satellite cell, which acts as a muscle stem cell, and the other is the mesenchymal progenitor, which contributes to muscle pathogeneses such as fat infiltration and fibrosis. Detailed and accurate characterization of these progenitors in humans remains elusive. Here, we performed comprehensive cell-surface protein profiling of the two progenitor populations residing in human skeletal muscle and identified three previously unrecognized markers: CD82 and CD318 for satellite cells and CD201 for mesenchymal progenitors. These markers distinguish myogenic and mesenchymal progenitors, and enable efficient isolation of the two types of progenitors. Functional study revealed that CD82 ensures expansion and preservation of myogenic progenitors by suppressing excessive differentiation, and CD201 signaling favors adipogenesis of mesenchymal progenitors. Thus, cell-surface proteins identified here are not only useful markers but also functionally important molecules, and provide valuable insight into human muscle biology and diseases.

  6. Green tea extract attenuates muscle loss and improves muscle function during disuse, but fails to improve muscle recovery following unloading in aged rats

    Science.gov (United States)

    Bennett, Brian T.; Wilson, Joseph C.; Sperringer, Justin; Mohamed, Junaith S.; Edens, Neile K.; Pereira, Suzette L.

    2014-01-01

    In this study we tested the hypothesis that green tea extract (GTE) would improve muscle recovery after reloading following disuse. Aged (32 mo) Fischer 344 Brown Norway rats were randomly assigned to receive either 14 days of hindlimb suspension (HLS) or 14 days of HLS followed by normal ambulatory function for 14 days (recovery). Additional animals served as cage controls. The rats were given GTE (50 mg/kg body wt) or water (vehicle) by gavage 7 days before and throughout the experimental periods. Compared with vehicle treatment, GTE significantly attenuated the loss of hindlimb plantaris muscle mass (−24.8% vs. −10.7%, P muscle function or mass compared with vehicle treatment, animals given green tea via gavage maintained the lower losses of muscle mass that were found during HLS (−25.2% vs. −16.0%, P muscle fiber cross-sectional area loss in both plantaris (−39.9% vs. −23.9%, P muscles after HLS. This green tea-induced difference was not transient but was maintained over the reloading period for plantaris (−45.6% vs. −21.5%, P muscle fiber cross-sectional area (−38.7% vs. −10.9%, P muscles during recovery from HLS compared with vehicle-treated muscles and decreased oxidative stress and abundance of the Bcl-2-associated X protein (Bax), yet this did not further improve muscle recovery in reloaded muscles. These data suggest that muscle recovery following disuse in aging is complex. Although satellite cell proliferation and differentiation are critical for muscle repair to occur, green tea-induced changes in satellite cell number is by itself insufficient to improve muscle recovery following a period of atrophy in old rats. PMID:25414242

  7. Development of a nitric oxide-releasing analogue of the muscle relaxant guaifenesin for skeletal muscle satellite cell myogenesis.

    Science.gov (United States)

    Wang, Guqi; Burczynski, Frank J; Hasinoff, Brian B; Zhang, Kaidong; Lu, Qilong; Anderson, Judy E

    2009-01-01

    Nitric oxide (NO) mediates activation of satellite precursor cells to enter the cell cycle. This provides new precursor cells for skeletal muscle growth and muscle repair from injury or disease. Targeting a new drug that specifically delivers NO to muscle has the potential to promote normal function and treat neuromuscular disease, and would also help to avoid side effects of NO from other treatment modalities. In this research, we examined the effectiveness of the NO donor, iosorbide dinitrate (ISDN), and a muscle relaxant, methocarbamol, in promoting satellite cell activation assayed by muscle cell DNA synthesis in normal adult mice. The work led to the development of guaifenesin dinitrate (GDN) as a new NO donor for delivering nitric oxide to muscle. The results revealed that there was a strong increase in muscle satellite cell activation and proliferation, demonstrated by a significant 38% rise in DNA synthesis after a single transdermal treatment with the new compound for 24 h. Western blot and immunohistochemistry analyses showed that the markers of satellite cell myogenesis, expression of myf5, myogenin, and follistatin, were increased after 24 h oral administration of the compound in adult mice. This research extends our understanding of the outcomes of NO-based treatments aimed at promoting muscle regeneration in normal tissue. The potential use of such treatment for conditions such as muscle atrophy in disuse and aging, and for the promotion of muscle tissue repair as required after injury or in neuromuscular diseases such as muscular dystrophy, is highlighted.

  8. In vivo gene editing in dystrophic mouse muscle and muscle stem cells.

    Science.gov (United States)

    Tabebordbar, Mohammadsharif; Zhu, Kexian; Cheng, Jason K W; Chew, Wei Leong; Widrick, Jeffrey J; Yan, Winston X; Maesner, Claire; Wu, Elizabeth Y; Xiao, Ru; Ran, F Ann; Cong, Le; Zhang, Feng; Vandenberghe, Luk H; Church, George M; Wagers, Amy J

    2016-01-22

    Frame-disrupting mutations in the DMD gene, encoding dystrophin, compromise myofiber integrity and drive muscle deterioration in Duchenne muscular dystrophy (DMD). Removing one or more exons from the mutated transcript can produce an in-frame mRNA and a truncated, but still functional, protein. In this study, we developed and tested a direct gene-editing approach to induce exon deletion and recover dystrophin expression in the mdx mouse model of DMD. Delivery by adeno-associated virus (AAV) of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 endonucleases coupled with paired guide RNAs flanking the mutated Dmd exon23 resulted in excision of intervening DNA and restored the Dmd reading frame in myofibers, cardiomyocytes, and muscle stem cells after local or systemic delivery. AAV-Dmd CRISPR treatment partially recovered muscle functional deficiencies and generated a pool of endogenously corrected myogenic precursors in mdx mouse muscle.

  9. Assessment of isokinetic muscle function in Korea male volleyball athletes

    OpenAIRE

    Kim, Chang-Gyun; Jeoung, Bog Ja

    2016-01-01

    Volleyball players performed numerous repetitions of spike actions, which uses and requires strong and explosive force, and control of the muscles of the shoulder, lower back, and legs. Muscle imbalance is one of the main causes of sport injuries. The purpose of this study was to assess isokinetic muscle functions in male volleyball players. We thus aim to accurately evaluate their muscle functions, and identify the best training strategy to achieve optimal muscle strength balance in future t...

  10. Muscle quality in aging: a multi-dimensional approach to muscle functioning with applications for treatment.

    Science.gov (United States)

    Fragala, Maren S; Kenny, Anne M; Kuchel, George A

    2015-05-01

    Aging is often accompanied by declines in physical functioning which impedes older adults' quality of life, sense of independence, and ability to perform daily tasks. Age-related decreases in skeletal muscle quantity, termed sarcopenia, have traditionally been blamed for these physical decrements. However, recent evidence suggests that the quality of muscle tissue may be more functionally relevant than its quantity. 'Muscle quality' has been emerging as a means to elucidate and describe the intricate intramuscular changes associated with muscle performance in the context of aging and sarcopenia. While muscle quality has most commonly been defined in terms of muscle composition or relative strength, at the core, muscle quality really describes muscle's ability to function. Skeletal muscle displays a strong structure-function relationship by which several architectural characteristics factor into its functional capacity. This review describes the structural, physiological, and functional determinants of muscle quality at the tissue and cellular level, while also introducing other novel parameters such as sarcomere spacing and integrity, circulating biomarkers, and the muscle quality index. Muscle qualitative features are described from the perspective of how physical exercise may improve muscle quality in older adults. This broad, multidimensional perspective of muscle quality in the context of aging and sarcopenia offers comprehensive insights for consideration and integration in developing improved prognostic tools for research and clinical care, while also promoting translational approaches to the design of novel targeted intervention strategies designed to maintain function and mobility into late life.

  11. Muscle Progenitor Cell Regenerative Capacity in the Torn Rotator Cuff

    Science.gov (United States)

    Meyer, Gretchen A.; Farris, Ashley L.; Sato, Eugene; Gibbons, Michael; Lane, John G.; Ward, Samuel R.; Engler, Adam J.

    2014-01-01

    Chronic rotator cuff (RC) tears affect a large portion of the population and result in substantial upper extremity impairment, shoulder weakness, pain and limited range of motion. Regardless of surgical or conservative treatment, persistent atrophic muscle changes limit functional restoration and may contribute to surgical failure. We hypothesized that deficits in the skeletal muscle progenitor (SMP) cell pool could contribute to poor muscle recovery following tendon repair. Biopsies were obtained from patients undergoing arthroscopic RC surgery. The SMP population was quantified, isolated and assayed in culture for its ability to proliferate and fuse in-vitro and in-vivo. The SMP population was larger in muscles from cuffs with partial tears compared with no tears or full thickness tears. However, SMPs from muscles in the partial tear group also exhibited reduced proliferative ability. Cells from all cuff states were able to fuse robustly in culture and engraft when injected into injured mouse muscle, suggesting that when given the correct signals, SMPs are capable of contributing to muscle hypertrophy and regeneration regardless of tear severity. The fact that this does not appear to happen in-vivo helps focus future therapeutic targets for promoting muscle recovery following rotator cuff repairs and may help improve clinical outcomes. PMID:25410765

  12. Muscle progenitor cell regenerative capacity in the torn rotator cuff.

    Science.gov (United States)

    Meyer, Gretchen A; Farris, Ashley L; Sato, Eugene; Gibbons, Michael; Lane, John G; Ward, Samuel R; Engler, Adam J

    2015-03-01

    Chronic rotator cuff (RC) tears affect a large portion of the population and result in substantial upper extremity impairment, shoulder weakness, pain, and limited range of motion. Regardless of surgical or conservative treatment, persistent atrophic muscle changes limit functional restoration and may contribute to surgical failure. We hypothesized that deficits in the skeletal muscle progenitor (SMP) cell pool could contribute to poor muscle recovery following tendon repair. Biopsies were obtained from patients undergoing arthroscopic RC surgery. The SMP population was quantified, isolated, and assayed in culture for its ability to proliferate and fuse in vitro and in vivo. The SMP population was larger in muscles from cuffs with partial tears compared with no tears or full thickness tears. However, SMPs from muscles in the partial tear group also exhibited reduced proliferative ability. Cells from all cuff states were able to fuse robustly in culture and engraft when injected into injured mouse muscle, suggesting that when given the correct signals, SMPs are capable of contributing to muscle hypertrophy and regeneration regardless of tear severity. The fact that this does not appear to happen in vivo helps focus future therapeutic targets for promoting muscle recovery following rotator cuff repairs and may help improve clinical outcomes.

  13. A small molecule PAI-1 functional inhibitor attenuates neointimal hyperplasia and vascular smooth muscle cell survival by promoting PAI-1 cleavage.

    Science.gov (United States)

    Simone, Tessa M; Higgins, Stephen P; Archambeault, Jaclyn; Higgins, Craig E; Ginnan, Roman G; Singer, Harold; Higgins, Paul J

    2015-05-01

    Plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of urokinase-and tissue-type plasminogen activators (uPA and tPA), is an injury-response gene implicated in the development of tissue fibrosis and cardiovascular disease. PAI-1 mRNA and protein levels were elevated in the balloon catheter-injured carotid and in the vascular smooth muscle cell (VSMC)-enriched neointima of ligated arteries. PAI-1/uPA complex formation and PAI-1 antiproteolytic activity can be inhibited, via proteolytic cleavage, by the small molecule antagonist tiplaxtinin which effectively increased the VSMC apoptotic index in vitro and attenuated carotid artery neointimal formation in vivo. In contrast to the active full-length serine protease inhibitor (SERPIN), elastase-cleaved PAI-1 (similar to tiplaxtinin) also promoted VSMC apoptosis in vitro and similarly reduced neointimal formation in vivo. The mechanism through which cleaved PAI-1 (CL-PAI-1) stimulates apoptosis appears to involve the TNF-α family member TWEAK (TNF-α weak inducer of apoptosis) and it's cognate receptor, fibroblast growth factor (FGF)-inducible 14 (FN14). CL-PAI-1 sensitizes cells to TWEAK-stimulated apoptosis while full-length PAI-1 did not, presumably due to its ability to down-regulate FN14 in a low density lipoprotein receptor-related protein 1 (LRP1)-dependent mechanism. It appears that prolonged exposure of VSMCs to CL-PAI-1 induces apoptosis by augmenting TWEAK/FN14 pro-apoptotic signaling. This work identifies a critical, anti-stenotic, role for a functionally-inactive (at least with regard to its protease inhibitory function) cleaved SERPIN. Therapies that promote the conversion of full-length to cleaved PAI-1 may have translational implications.

  14. Muscle repair and regeneration: stem cells, scaffolds, and the contributions of skeletal muscle to amphibian limb regeneration.

    Science.gov (United States)

    Milner, Derek J; Cameron, Jo Ann

    2013-01-01

    Skeletal muscle possesses a robust innate capability for repair of tissue damage. Natural repair of muscle damage is a stepwise process that requires the coordinated activity of a number of cell types, including infiltrating macrophages, resident myogenic and non-myogenic stem cells, and connective tissue fibroblasts. Despite the proficiency of this intrinsic repair capability, severe injuries that result in significant loss of muscle tissue overwhelm the innate repair process and require intervention if muscle function is to be restored. Recent advances in stem cell biology, regenerative medicine, and materials science have led to attempts at developing tissue engineering-based methods for repairing severe muscle defects. Muscle tissue also plays a role in the ability of tailed amphibians to regenerate amputated limbs through epimorphic regeneration. Muscle contributes adult stem cells to the amphibian regeneration blastema, but it can also contribute blastemal cells through the dedifferentiation of multinucleate myofibers into mononuclear precursors. This fascinating plasticity and its contributions to limb regeneration have prompted researchers to investigate the potential for mammalian muscle to undergo dedifferentiation. Several works have shown that mammalian myotubes can be fragmented into mononuclear cells and induced to re-enter the cell cycle, but mature myofibers are resistant to fragmentation. However, recent works suggest that there may be a path to inducing fragmentation of mature myofibers into proliferative multipotent cells with the potential for use in muscle tissue engineering and regenerative therapies.

  15. Resistance training induces qualitative changes in muscle morphology, muscle architecture, and muscle function in elderly postoperative patients

    DEFF Research Database (Denmark)

    Suetta, Charlotte; Andersen, Jesper L; Dalgas, Ulrik;

    2008-01-01

    beneficial qualitative changes in muscle fiber morphology and muscle architecture in elderly postoperative patients. In contrast, rehabilitation regimes based on functional exercises and neuromuscular electrical stimulation had no effect. The present data emphasize the importance of resistance training...

  16. ARSENIC INDUCES SUSTAINED IMPAIRMENT OF SKELETAL MUSCLE AND MUSCLE PROGENITOR CELL ULTRASTRUCTURE AND BIOENERGETICS

    Science.gov (United States)

    Fabrisia, Ambrosio; Elke, Brown; Donna, Stolz; Ricardo, Ferrari; Bret, Goodpaster; Bridget, Deasy; Giovanna, Distefano; Alexandra, Roperti; Amin, Cheikhi; Yesica, Garciafigueroa; Aaron, Barchowsky

    2014-01-01

    Over 4 million individuals in the US, and over 140 million individuals worldwide, are exposed daily to arsenic-contaminated drinking water. Human exposures can range from below the current limit of 10 µg/L to over 1 mg/L, with 100 µg/L promoting disease in a large portion of those exposed. Although increased attention has recently been paid to myopathy following arsenic exposure, the pathogenic mechanisms underlying clinical symptoms remain poorly understood. This study tested the hypothesis that arsenic induces lasting muscle mitochondrial dysfunction and impairs metabolism. When compared to non-exposed controls, mice exposed to drinking water containing 100µg/L arsenite for 5 weeks demonstrated impaired muscle function, mitochondrial myopathy, and altered oxygen consumption that were concomitant with increased mitochondrial fusion gene transcription. There was no difference in levels of inorganic arsenic or its mononomethyl- and dimethyl- metabolites between controls and exposed muscles, confirming that arsenic does not accumulate in muscle. Nevertheless, muscle progenitor cells isolated from exposed mice recapitulated the aberrant myofiber phenotype and were more resistant to oxidative stress, generated more reactive oxygen species, and displayed autophagic mitochondrial morphology, as compared to cells isolated from non-exposed mice. These pathological changes from a possible maladaptive oxidative stress response provide insight into declines in muscle functioning caused by exposure to this common environmental contaminant. PMID:24960579

  17. Interactions between neutrophils and macrophages promote macrophage killing of rat muscle cells in vitro

    Science.gov (United States)

    Nguyen, Hal X.; Tidball, James G.

    2003-01-01

    Current evidence indicates that the physiological functions of inflammatory cells are highly sensitive to their microenvironment, which is partially determined by the inflammatory cells and their potential targets. In the present investigation, interactions between neutrophils, macrophages and muscle cells that may influence muscle cell death are examined. Findings show that in the absence of macrophages, neutrophils kill muscle cells in vitro by superoxide-dependent mechanisms, and that low concentrations of nitric oxide (NO) protect against neutrophil-mediated killing. In the absence of neutrophils, macrophages kill muscle cells through a NO-dependent mechanism, and the presence of target muscle cells causes a three-fold increase in NO production by macrophages, with no change in the concentration of inducible nitric oxide synthase. Muscle cells that are co-cultured with both neutrophils and macrophages in proportions that are observed in injured muscle show cytotoxicity through a NO-dependent, superoxide-independent mechanism. Furthermore, the concentration of myeloid cells that is necessary for muscle killing is greatly reduced in assays that use mixed myeloid cell populations, rather than uniform populations of neutrophils or macrophages. These findings collectively show that the magnitude and mechanism of muscle cell killing by myeloid cells are modified by interactions between muscle cells and neutrophils, between muscle cells and macrophages and between macrophages and neutrophils.

  18. [Molecular mechanism maintaining muscle satellite cells and the roles in sarcopenia.

    Science.gov (United States)

    Takemoto, Yusei; Fukada, So-Ichiro

    2017-01-01

    Skeletal muscle has its stem cell named satellite cell. The absence of satellite cells does not allow muscle regeneration, it is unquestionable that satellite cell is indispensable for muscle regeneration processes. A certain number of satellite cells appear to be necessary for the successful muscle regeneration, meaning the maintenance of the satellite cells is essential for the functional homeostasis of skeletal muscle. Recent studies have revealed the molecular mechanism underlying satellite cell maintenance in a steady state. A loss of those molecules responsible for the maintenance often results in decreased satellite cell pool and reduced regeneration ability. On the other hand, the contribution of satellite cells to muscle hypertrophy or aged-related atrophy(sarcopenia)is controversial. In this review, we will introduce the molecules that regulate satellite cells homeostasis in the dormant state and then further discuss the recent results on the roles of satellite cell in sarcopenia.

  19. Embryonic stem cells improve skeletal muscle recovery after extreme atrophy in mice.

    Science.gov (United States)

    Artioli, Guilherme Giannini; De Oliveira Silvestre, João Guilherme; Guilherme, João Paulo Limongi França; Baptista, Igor Luchini; Ramos, Gracielle Vieira; Da Silva, Willian José; Miyabara, Elen Haruka; Moriscot, Anselmo Sigari

    2015-03-01

    We injected embryonic stem cells into mouse tibialis anterior muscles subjected to botulinum toxin injections as a model for reversible neurogenic atrophy. Muscles were exposed to botulinum toxin for 4 weeks and allowed to recover for up to 6 weeks. At the onset of recovery, a single muscle injection of embryonic stem cells was administered. The myofiber cross-sectional area, single twitch force, peak tetanic force, time-to-peak force, and half-relaxation time were determined. Although the stem cell injection did not affect the myofiber cross-sectional area gain in recovering muscles, most functional parameters improved significantly compared with those of recovering muscles that did not receive the stem cell injection. Muscle function recovery was accelerated by embryonic stem cell delivery in this durable neurogenic atrophy model. We conclude that stem cells should be considered a potential therapeutic tool for recovery after extreme skeletal muscle atrophy. © 2014 Wiley Periodicals, Inc.

  20. Isolation of Endothelial Cells and Vascular Smooth Muscle Cells from Internal Mammary Artery Tissue

    Science.gov (United States)

    Moss, Stephanie C.; Bates, Michael; Parrino, Patrick E.; Woods, T. Cooper

    2007-01-01

    Analyses of vascular smooth muscle cell and endothelial cell function through tissue culture techniques are often employed to investigate the underlying mechanisms regulating cardiovascular disease. As diseases such as diabetes mellitus and chronic kidney disease increase a patient's risk of cardiovascular disease, the development of methods for examining the effects of these diseases on vascular smooth muscle cells and endothelial cells is needed. Commercial sources of endothelial cells and vascular smooth muscle cells generally provide minimal donor information and are in limited supply. This study was designed to determine if vascular smooth muscle cells and endothelial cells could be isolated from human internal mammary arteries obtained from donors undergoing coronary artery bypass graft surgery. As coronary artery bypass graft surgery is a commonly performed procedure, this method would provide a new source for these cells that when combined with the donor's medical history will greatly enhance our studies of the effects of complicating diseases on vascular biology. Internal mammary artery tissue was obtained from patients undergoing coronary artery bypass graft surgery. Through a simple method employing two separate tissue digestions, vascular smooth muscle cells and endothelial cells were isolated and characterized. The isolated vascular smooth muscle cells and endothelial cells exhibited the expected morphology and were able to be passaged for further analysis. The vascular smooth muscle cells exhibited positive staining for α-smooth muscle actin and the endothelial cells exhibited positive staining for CD31. The overall purity of the isolations was > 95%. This method allows for the isolation of endothelial cells and vascular smooth muscle cells from internal mammary arteries, providing a new tool for investigations into the interplay of vascular diseases and complicating diseases such as diabetes and kidney disease. PMID:21603530

  1. Skeletal Muscle Cell Induction from Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Yusaku Kodaka

    2017-01-01

    Full Text Available Embryonic stem cells (ESCs and induced pluripotent stem cells (iPSCs have the potential to differentiate into various types of cells including skeletal muscle cells. The approach of converting ESCs/iPSCs into skeletal muscle cells offers hope for patients afflicted with the skeletal muscle diseases such as the Duchenne muscular dystrophy (DMD. Patient-derived iPSCs are an especially ideal cell source to obtain an unlimited number of myogenic cells that escape immune rejection after engraftment. Currently, there are several approaches to induce differentiation of ESCs and iPSCs to skeletal muscle. A key to the generation of skeletal muscle cells from ESCs/iPSCs is the mimicking of embryonic mesodermal induction followed by myogenic induction. Thus, current approaches of skeletal muscle cell induction of ESCs/iPSCs utilize techniques including overexpression of myogenic transcription factors such as MyoD or Pax3, using small molecules to induce mesodermal cells followed by myogenic progenitor cells, and utilizing epigenetic myogenic memory existing in muscle cell-derived iPSCs. This review summarizes the current methods used in myogenic differentiation and highlights areas of recent improvement.

  2. Intrinsic hand muscle function, part 1: creating a functional grasp.

    Science.gov (United States)

    Arnet, Ursina; Muzykewicz, David A; Fridén, Jan; Lieber, Richard L

    2013-11-01

    Regaining hand function has been identified as the highest priority for persons with tetraplegia. In many patients, finger flexion can be restored with a tendon transfer of extensor carpi radialis longus to flexor digitorum profundus (FDP). In the absence of intrinsic function, this results in a roll-up finger movement, which tends to push large objects out of grasp. To enable patients to grasp objects of varying sizes, a functional grasp is required that has a larger excursion of fingertip-to-palm distance than can be supplied without intrinsic function. The aim of this study was to quantify the role of intrinsic muscle force in creating a functional grasp. Finger kinematics during grasp were measured on 5 cadaveric hands. To simulate finger flexion, the FDP was activated by a motor and intrinsic muscles were loaded at various levels (0, 125, 250, 375, or 500 g). Finger movement was characterized by the order of metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joint flexion and by the maximal fingertip-to-palm distance during finger closure. Without any intrinsic muscle contribution (0-g load), FDP activation resulted in flexion of all 3 joints, whereby flexion began at the proximal interphalangeal joint, followed by the distal interphalangeal joint, and then the metacarpophalangeal joint. With increasing intrinsic muscle load, finger flexion was initiated at the metacarpophalangeal joint, followed by the proximal interphalangeal and distal interphalangeal joints. This altered joint flexion order resulted in a larger maximal fingertip-to-palm distance during finger flexion. The difference between the 2 extreme conditions (0 g vs 500 g of intrinsic muscle load) was 19 mm. These findings demonstrate that simultaneous activation of the FDP and the intrinsic muscles results in an apparently more functional hand closing compared with FDP activation alone because of altered kinematics and larger fingertip-to-palm distances. These findings

  3. Molecular basis of the myogenic profile of aged human skeletal muscle satellite cells during differentiation

    OpenAIRE

    Pietrangelo, Tiziana; Puglielli, Cristina; Mancinelli, Rosa; Beccafico, Sara; Fanò, Giorgio; Fulle, Stefania

    2009-01-01

    Abstract Sarcopenia is the age-related loss of muscle mass, strength and function. Human muscle proteins are synthesized at a slower rate in the elderly than in young adults, leading to atrophy and muscle mass loss with a decline in the functional capability. Additionally, aging is accompanied by a decrease in the ability of muscle tissue to regenerate following injury or overuse due to the impairment of intervening satellite cells, in which we previously reported oxidative damage ...

  4. 6A3-5/Osa2 is an Early Activated Gene Implicated in the Control of Vascular Smooth Muscle Cell Functions

    Directory of Open Access Journals (Sweden)

    Gwenaele Garin

    2006-01-01

    Full Text Available Vascular smooth muscle cells (VSMC growth plays a key role in the pathophysiology of vascular diseases. However, the molecular mechanisms controlling gene transcription in VSMC remain poorly understood. We previously identified, by differential display, a new gene (6A3-5 overexpressed in proliferating rat VSMC. In this study, we have cloned the full-length cDNA by screening a rat foetal brain cDNA library and investigated its functions. The 6A3-5 protein shows 4 putative conserved functional motifs: a DNA binding domain called ARID (AT-rich interaction domain, two recently described motifs (Osa Homology Domain, and a nuclear localization signal. The deduced protein sequence was observed to be 85% identical to the recently described human Osa2 gene. Immunolabelling, using an anti-6A3-5/Osa2 monoclonal antibody, showed a nuclear localization of the 6A3-5/Osa2 protein. In addition, PDGF upregulated 6A3-5/Osa2 expression at both the transcript and protein levels in a dose and time-dependent fashion. The pattern of upregulation by PDGF was reminiscent of the early responsive gene c-fos. The PDGF-induced upregulation of 6A3-5/Osa2 and proliferation of VSMC were significantly inhibited in a dose and sequence-dependent fashion by an antisense, but not by sense, scrambled or mismatched oligonucleotides directed against 6A3-5/Osa2. In VSMC of aortas derived from hypertensive (LH rats, 6A3-5/Osa2 is overexpressed as compared to that in normotensive (LL rats. The 6A3-5/Osa2-gene expression is downregulated by an ACE inhibitor and upregulated by exogenous AngiotensinII in LH rats. In summary, these results indicate that 6A3-5/Osa2 is an early activated gene that belongs to a new family of proteins involved in the control of VSMC growth.

  5. Regulation of satellite cell function in sarcopenia

    Directory of Open Access Journals (Sweden)

    Stephen E Alway

    2014-09-01

    Full Text Available The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell function that is impacted by the environment (niche of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia, and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration. While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function.

  6. Transiently Active Wnt/β-Catenin Signaling Is Not Required but Must Be Silenced for Stem Cell Function during Muscle Regeneration

    Directory of Open Access Journals (Sweden)

    Malea M. Murphy

    2014-09-01

    Full Text Available Adult muscle’s exceptional capacity for regeneration is mediated by muscle stem cells, termed satellite cells. As with many stem cells, Wnt/β-catenin signaling has been proposed to be critical in satellite cells during regeneration. Using new genetic reagents, we explicitly test in vivo whether Wnt/β-catenin signaling is necessary and sufficient within satellite cells and their derivatives for regeneration. We find that signaling is transiently active in transit-amplifying myoblasts, but is not required for regeneration or satellite cell self-renewal. Instead, downregulation of transiently activated β-catenin is important to limit the regenerative response, as continuous regeneration is deleterious. Wnt/β-catenin activation in adult satellite cells may simply be a vestige of their developmental lineage, in which β-catenin signaling is critical for fetal myogenesis. In the adult, surprisingly, we show that it is not activation but rather silencing of Wnt/β-catenin signaling that is important for muscle regeneration.

  7. Effect of Real and Simulated Microgravity on Muscle Function

    Science.gov (United States)

    1997-01-01

    In this session, Session JA3, the discussion focuses on the following topics: Changes in Calf Muscle Performance, Energy Metabolism, and Muscle Volume Caused by Long Term Stay on Space Station MIR; Vibrografic Signs of Autonomous Muscle Tone Studied in Long Term Space Missions; Reduction of Muscle Strength After Long Duration Space Flights is Associated Primarily with Changes in Neuromuscular Function; The Effects of a 115-Day Spaceflight on Neuromuscular Function in Crewman; Effects of 17-Day Spaceflight on Human Triceps Surae Electrically-Evoked Contractions; Effects of Muscle Unloading on EMG Spectral Parameters; and Myofiber Wound-Mediated FGF Release and Muscle Atrophy During Bedrest.

  8. Functional recovery of completely denervated muscle: implications for innervation of tissue-engineered muscle.

    Science.gov (United States)

    Kang, Sung-Bum; Olson, Jennifer L; Atala, Anthony; Yoo, James J

    2012-09-01

    Tissue-engineered muscle has been proposed as a solution to repair volumetric muscle defects and to restore muscle function. To achieve functional recovery, engineered muscle tissue requires integration of the host nerve. In this study, we investigated whether denervated muscle, which is analogous to tissue-engineered muscle tissue, can be reinnervated and can recover muscle function using an in vivo model of denervation followed by neurotization. The outcomes of this investigation may provide insights on the ability of tissue-engineered muscle to integrate with the host nerve and acquire normal muscle function. Eighty Lewis rats were classified into three groups: a normal control group (n=16); a denervated group in which sciatic innervations to the gastrocnemius muscle were disrupted (n=32); and a transplantation group in which the denervated gastrocnemius was repaired with a common peroneal nerve graft into the muscle (n=32). Neurofunctional behavior, including extensor postural thrust (EPT), withdrawal reflex latency (WRL), and compound muscle action potential (CMAP), as well as histological evaluations using alpha-bungarotoxin and anti-NF-200 were performed at 2, 4, 8, and 12 weeks (n=8) after surgery. We found that EPT was improved by transplantation of the nerve grafts, but the EPT values in the transplanted animals at 12 weeks postsurgery were still significantly lower than those measured for the normal control group at 4 weeks (EPT, 155.0±38.9 vs. 26.3±13.8 g, ptissue is able to regenerate neuromuscular junctions within denervated muscle, and thus the muscle can recover partial function. However, the function of the denervated muscle remains in the subnormal range even at 12 weeks after direct nerve transplantation. These results suggest that tissue-engineered muscle, which is similarly denervated, could be innervated and become functional in vivo if it is properly integrated with the host nerve.

  9. Lower limb asymmetry in mechanical muscle function

    DEFF Research Database (Denmark)

    Jordan, M J; Aagaard, Per; Herzog, W

    2015-01-01

    Due to a high incidence of anterior cruciate ligament (ACL) re-injury in alpine ski racers, this study aims to assess functional asymmetry in the countermovement jump (CMJ), squat jump (SJ), and leg muscle mass in elite ski racers with and without anterior cruciate ligament reconstruction (ACL......-R). Elite alpine skiers with ACL-R (n = 9; 26.2 ± 11.8 months post-op) and uninjured skiers (n = 9) participated in neuromuscular screening. Vertical ground reaction force during the CMJ and SJ was assessed using dual force plate methodology to obtain phase-specific bilateral asymmetry indices (AIs...

  10. Discovery of Novel Small Molecules that Activate Satellite Cell Proliferation and Enhance Repair of Damaged Muscle.

    Science.gov (United States)

    Billin, Andrew N; Bantscheff, Marcus; Drewes, Gerard; Ghidelli-Disse, Sonja; Holt, Jason A; Kramer, Henning F; McDougal, Alan J; Smalley, Terry L; Wells, Carrow I; Zuercher, William J; Henke, Brad R

    2016-02-19

    Skeletal muscle progenitor stem cells (referred to as satellite cells) represent the primary pool of stem cells in adult skeletal muscle responsible for the generation of new skeletal muscle in response to injury. Satellite cells derived from aged muscle display a significant reduction in regenerative capacity to form functional muscle. This decrease in functional recovery has been attributed to a decrease in proliferative capacity of satellite cells. Hence, agents that enhance the proliferative abilities of satellite cells may hold promise as therapies for a variety of pathological settings, including repair of injured muscle and age- or disease-associated muscle wasting. Through phenotypic screening of isolated murine satellite cells, we identified a series of 2,4-diaminopyrimidines (e.g., 2) that increased satellite cell proliferation. Importantly, compound 2 was effective in accelerating repair of damaged skeletal muscle in an in vivo mouse model of skeletal muscle injury. While these compounds were originally prepared as c-Jun N-terminal kinase 1 (JNK-1) inhibitors, structure-activity analyses indicated JNK-1 inhibition does not correlate with satellite cell activity. Screening against a broad panel of kinases did not result in identification of an obvious molecular target, so we conducted cell-based proteomics experiments in an attempt to identify the molecular target(s) responsible for the potentiation of the satellite cell proliferation. These data provide the foundation for future efforts to design improved small molecules as potential therapeutics for muscle repair and regeneration.

  11. Fast activation of Ca2+-ATPases in plasma membranes from cardiac muscle and from ascites carcinoma cells: a possible function of endogenous calmodulin.

    Science.gov (United States)

    Wetzker, R; Klinger, R; Haase, H; Vetter, R; Böhmer, F D

    1987-01-01

    Content of endogenous calmodulin, binding of calmodulin to, and Ca2+-ATPase activity in plasma membranes of cardiac muscle. Ehrlich ascites carcinoma (EAC) cells and erythrocytes were examined. The content of endogenous calmodulin in cardiac and EAC cells was shown to be considerably higher than in erythrocyte membranes. Ca2+-independent binding of calmodulin to cardiac and EAC cell membranes was found to be realized by some low molecular weight proteins. Ca2+-ATPases in cardiac and EAC cell membranes differ from those in erythrocytes with respect to their activation by Ca2+ and calmodulin. The erythrocyte enzyme is strongly stimulated by exogenous calmodulin and reaches its maximum activity about 2 min after Ca2+-addition. In contrast, the Ca2+-ATPases in cardiac and EAC cell plasma membranes cannot be considerably stimulated by exogenous calmodulin and are instantaneously activated by Ca2+.

  12. Extracellular matrix components direct porcine muscle stem cell behavior

    Energy Technology Data Exchange (ETDEWEB)

    Wilschut, Karlijn J. [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands); Haagsman, Henk P. [Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht (Netherlands); Roelen, Bernard A.J., E-mail: b.a.j.roelen@uu.nl [Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 104, 3584 CM, Utrecht (Netherlands)

    2010-02-01

    In muscle tissue, extracellular matrix proteins, together with the vasculature system, muscle-residence cells and muscle fibers, create the niche for muscle stem cells. The niche is important in controlling proliferation and directing differentiation of muscle stem cells to sustain muscle tissue. Mimicking the extracellular muscle environment improves tools exploring the behavior of primary muscle cells. Optimizing cell culture conditions to maintain muscle commitment is important in stem cell-based studies concerning toxicology screening, ex vivo skeletal muscle tissue engineering and in the enhancement of clinical efficiency. We used the muscle extracellular matrix proteins collagen type I, fibronectin, laminin, and also gelatin and Matrigel as surface coatings of tissue culture plastic to resemble the muscle extracellular matrix. Several important factors that determine myogenic commitment of the primary muscle cells were characterized by quantitative real-time RT-PCR and immunofluorescence. Adhesion of high PAX7 expressing satellite cells was improved if the cells were cultured on fibronectin or laminin coatings. Cells cultured on Matrigel and laminin coatings showed dominant integrin expression levels and exhibited an activated Wnt pathway. Under these conditions both stem cell proliferation and myogenic differentiation capacity were superior if compared to cells cultured on collagen type I, fibronectin and gelatin. In conclusion, Matrigel and laminin are the preferred coatings to sustain the proliferation and myogenic differentiation capacity of the primary porcine muscle stem cells, when cells are removed from their natural environment for in vitro culture.

  13. 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.

  14. Pluripotent Stem Cells for Gene Therapy of Degenerative Muscle Diseases.

    Science.gov (United States)

    Loperfido, Mariana; Steele-Stallard, Heather B; Tedesco, Francesco Saverio; VandenDriessche, Thierry

    2015-01-01

    Human pluripotent stem cells represent a unique source for cell-based therapies and regenerative medicine. The intrinsic features of these cells such as their easy accessibility and their capacity to be expanded indefinitely overcome some limitations of conventional adult stem cells. Furthermore, the possibility to derive patient-specific induced pluripotent stem (iPS) cells in combination with the current development of gene modification methods could be used for autologous cell therapies of some genetic diseases. In particular, muscular dystrophies are considered to be a good candidate due to the lack of efficacious therapeutic treatments for patients to date, and in view of the encouraging results arising from recent preclinical studies. Some hurdles, including possible genetic instability and their efficient differentiation into muscle progenitors through vector/transgene-free methods have still to be overcome or need further optimization. Additionally, engraftment and functional contribution to muscle regeneration in pre-clinical models need to be carefully assessed before clinical translation. This review offers a summary of the advanced methods recently developed to derive muscle progenitors from pluripotent stem cells, as well as gene therapy by gene addition and gene editing methods using ZFNs, TALENs or CRISPR/Cas9. We have also discussed the main issues that need to be addressed for successful clinical translation of genetically corrected patient-specific pluripotent stem cells in autologous transplantation trials for skeletal muscle disorders.

  15. The emergence of Pax7-expressing muscle stem cells during vertebrate head muscle development

    Directory of Open Access Journals (Sweden)

    Julia eMeireles Nogueira

    2015-05-01

    Full Text Available Pax7 expressing muscle stem cells accompany all skeletal muscles in the body and in healthy individuals, efficiently repair muscle after injury. Currently, the in vitro manipulation and culture of these cells is still in its infancy, yet muscle stem cells may be the most promising route towards the therapy of muscle diseases such as muscular dystrophies.It is often overlooked that muscular dystrophies affect head and body skeletal muscle differently. Moreover, these muscles develop differently. Specifically, head muscle and its stem cells develop from the non-somitic head mesoderm which also has cardiac competence. To which extent head muscle stem cells retain properties of the early head mesoderm and might even be able to switch between a skeletal muscle and cardiac fate is not known. This is due to the fact that the timing and mechanisms underlying head muscle stem cell development are still obscure. Consequently, it is not clear at which time point one should compare the properties of head mesodermal cells and head muscle stem cells.To shed light on this, we traced the emergence of head muscle stem cells in the key vertebrate models for myogenesis, chicken, mouse, frog and zebrafish, using Pax7 as key marker. Our study reveals a common theme of head muscle stem cell development that is quite different from the trunk. Unlike trunk muscle stem cells, head muscle stem cells do not have a previous history of Pax7 expression, instead Pax7 expression emerges de-novo. The cells develop late, and well after the head mesoderm has committed to myogenesis. We propose that this unique mechanism of muscle stem cell development is a legacy of the evolutionary history of the chordate head mesoderm.

  16. Structure and function of masticatory muscles in a case of muscular dystrophy

    DEFF Research Database (Denmark)

    Bakke, M; Kirkeby, S; Jensen, B L

    1990-01-01

    Histologic examination of muscle biopsies and functional examination comprising electromyography and force measurements in a 19-yr-old boy with muscular dystrophy showed different wasting patterns of mandibular elevator and depressor muscles. Pronounced histopathologic changes were present...... in the masseter muscle, whereas pathologic findings in the anterior digastric muscle were limited to increased number of cells in slightly enlarged interfiber connective tissue. The masticatory pattern was distorted, and strength of mandibular elevator muscles was less than one third of the norm, whereas...... depressor strength corresponded more to reference values. This difference of muscular wasting might be caused by protective enzymes in the digastric muscle and/or functionally induced damage of the masseter. As affection from muscular dystrophy may vary greatly between the masticatory muscles, structural...

  17. Calcium ion in skeletal muscle: its crucial role for muscle function, plasticity, and disease

    DEFF Research Database (Denmark)

    Berchtold, M W; Brinkmeier, H; Müntener, M

    2000-01-01

    Mammalian skeletal muscle shows an enormous variability in its functional features such as rate of force production, resistance to fatigue, and energy metabolism, with a wide spectrum from slow aerobic to fast anaerobic physiology. In addition, skeletal muscle exhibits high plasticity that is based...... on the potential of the muscle fibers to undergo changes of their cytoarchitecture and composition of specific muscle protein isoforms. Adaptive changes of the muscle fibers occur in response to a variety of stimuli such as, e.g., growth and differentition factors, hormones, nerve signals, or exercise....... Additionally, the muscle fibers are arranged in compartments that often function as largely independent muscular subunits. All muscle fibers use Ca(2+) as their main regulatory and signaling molecule. Therefore, contractile properties of muscle fibers are dependent on the variable expression of proteins...

  18. 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.

  19. Cardiac function in muscular dystrophy associates with abdominal muscle pathology

    Science.gov (United States)

    Gardner, Brandon B.; Swaggart, Kayleigh A.; Kim, Gene; Watson, Sydeaka; McNally, Elizabeth M.

    2015-01-01

    Background The muscular dystrophies target muscle groups differentially. In mouse models of muscular dystrophy, notably the mdx model of Duchenne Muscular Dystrophy, the diaphragm muscle shows marked fibrosis and at an earlier age than other muscle groups, more reflective of the histopathology seen in human muscular dystrophy. Methods Using a mouse model of limb girdle muscular dystrophy, the Sgcg mouse, we compared muscle pathology across different muscle groups and heart. A cohort of nearly 200 Sgcg mice were studied using multiple measures of pathology including echocardiography, Evans blue dye uptake and hydroxyproline content in multiple muscle groups. Spearman rank correlations were determined among echocardiographic and pathological parameters. Findings The abdominal muscles were found to have more fibrosis than other muscle groups, including the diaphragm muscle. The abdominal muscles also had more Evans blue dye uptake than other muscle groups. The amount of diaphragm fibrosis was found to correlate positively with fibrosis in the left ventricle, and abdominal muscle fibrosis correlated with impaired left ventricular function. Fibrosis in the abdominal muscles negatively correlated with fibrosis in the diaphragm and right ventricles. Together these data reflect the recruitment of abdominal muscles as respiratory muscles in muscular dystrophy, a finding consistent with data from human patients. PMID:26029630

  20. Esophageal muscle cell interaction with biopolymers.

    Science.gov (United States)

    Korkmaz, Mevlit; Yakut, Tahsin; Narci, Adnan; Güvenç, B Haluk; Güilten, Tuna; Yağmurca, Murat; Yiğit, Barbaros; Bilir, Ayhan

    2007-02-01

    The in vitro interactions of esophageal smooth muscle cells (SMCs) with synthetic absorbable polymers were tested and artificial muscle tissues harvested from subcutaneous implantation were examined. Esophageal tissue samples from adult and fetal (25-day gestational age) rabbits were cut into small pieces and cultured in Dulbecco's Modified Eagle Medium supplemented with 10% fetal bovine serum. Growing cells were identified as SMCs by immunostaining for anti-actin and anti-myosin antibodies. Equal volumes of agar gel and medium were mixed and used for 3-D culture. 5x10(5) cells and 1 mg polyglycolic acid (PGA) and poly-lactide-co-glycolide acid (PLGA) fibers were seeded in six-well tissue culture plates. On days 2 and 7 growing cells were counted by a hemocytometer and cell-polymer interactions were evaluated with light microscopy. Adult and fetal SMCs were seeded onto the PGA and PLGA scaffolds, cultivated for two weeks, and implanted subcutaneously on the backs of the rabbits. Cell-polymer implants were retrieved after four weeks and muscle formation was evaluated histologically and immunohistochemically. Growing cells stained positive for actin and myosin proteins. Cell-polymer interactions were poor after 24 hours, whereas intensive attachment to the fibers was detected 48 hours following cultivation. Both fiber materials supported cell proliferation. PLGA scaffolds improved muscle formation more efficiently than PGA, and fetal and adult SMCs showed similar mass quality. Scaffolds are important as cell-carrying vehicles, and material-cell interactions should be tested before application. A 3-D culture prepared with agar gel and medium is practical for testing material toxicity.

  1. 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.

  2. 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...

  3. Neural compensation, muscle load distribution and muscle function in control of biped models

    Science.gov (United States)

    Bavarian, B.

    Three aspects of the neuromuscular control of muscle actuators in biped movements were studied: neural compensation, muscle load distribution, and muscle function. A block diagram of a neural control circuit model of the control nervous system is presented. Based on this block diagram a circuit comprised of a dynamic compensator, an inverse plant, and pre-programmed reference trajectory generators is proposed for control of a general n-link biped model. This circuit is used to study the postural stability and point-to-point voluntary movement of a two-link planar biped with two pairs of muscle models. The muscle load distribution, relevant to functional electrical stimulation of paraplegic patients for restoration of limited motor function, is considered. A quantitative analysis of the local controllability of a two-link planar biped model incorporating six major muscles of the lower extremities is presented. A model of the muscle for the lower extremities is presented.

  4. Cripto regulates skeletal muscle regeneration and modulates satellite cell determination by antagonizing myostatin.

    Science.gov (United States)

    Guardiola, Ombretta; Lafuste, Peggy; Brunelli, Silvia; Iaconis, Salvatore; Touvier, Thierry; Mourikis, Philippos; De Bock, Katrien; Lonardo, Enza; Andolfi, Gennaro; Bouché, Ann; Liguori, Giovanna L; Shen, Michael M; Tajbakhsh, Shahragim; Cossu, Giulio; Carmeliet, Peter; Minchiotti, Gabriella

    2012-11-20

    Skeletal muscle regeneration mainly depends on satellite cells, a population of resident muscle stem cells. However, our understanding of the molecular mechanisms underlying satellite cell activation is still largely undefined. Here, we show that Cripto, a regulator of early embryogenesis, is a novel regulator of muscle regeneration and satellite cell progression toward the myogenic lineage. Conditional inactivation of cripto in adult satellite cells compromises skeletal muscle regeneration, whereas gain of function of Cripto accelerates regeneration, leading to muscle hypertrophy. Moreover, we provide evidence that Cripto modulates myogenic cell determination and promotes proliferation by antagonizing the TGF-β ligand myostatin. Our data provide unique insights into the molecular and cellular basis of Cripto activity in skeletal muscle regeneration and raise previously undescribed implications for stem cell biology and regenerative medicine.

  5. Bioengineered constructs combined with exercise enhance stem cell-mediated treatment of volumetric muscle loss

    Science.gov (United States)

    Quarta, Marco; Cromie, Melinda; Chacon, Robert; Blonigan, Justin; Garcia, Victor; Akimenko, Igor; Hamer, Mark; Paine, Patrick; Stok, Merel; Shrager, Joseph B.; Rando, Thomas A.

    2017-01-01

    Volumetric muscle loss (VML) is associated with loss of skeletal muscle function, and current treatments show limited efficacy. Here we show that bioconstructs suffused with genetically-labelled muscle stem cells (MuSCs) and other muscle resident cells (MRCs) are effective to treat VML injuries in mice. Imaging of bioconstructs implanted in damaged muscles indicates MuSCs survival and growth, and ex vivo analyses show force restoration of treated muscles. Histological analysis highlights myofibre formation, neovascularisation, but insufficient innervation. Both innervation and in vivo force production are enhanced when implantation of bioconstructs is followed by an exercise regimen. Significant improvements are also observed when bioconstructs are used to treat chronic VML injury models. Finally, we demonstrate that bioconstructs made with human MuSCs and MRCs can generate functional muscle tissue in our VML model. These data suggest that stem cell-based therapies aimed to engineer tissue in vivo may be effective to treat acute and chronic VML. PMID:28631758

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

    Directory of Open Access Journals (Sweden)

    Amy Y Hsiao

    Full Text Available 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.

  7. 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.

  8. Calcium ion in skeletal muscle: its crucial role for muscle function, plasticity, and disease

    DEFF Research Database (Denmark)

    Berchtold, M W; Brinkmeier, H; Müntener, M

    2000-01-01

    . Additionally, the muscle fibers are arranged in compartments that often function as largely independent muscular subunits. All muscle fibers use Ca(2+) as their main regulatory and signaling molecule. Therefore, contractile properties of muscle fibers are dependent on the variable expression of proteins......+)-triggered muscle contraction under certain conditions or modulate other muscle activities such as protein metabolism, differentiation, and growth. Recently, several Ca(2+) signaling and handling molecules have been shown to be altered in muscle diseases. Functional alterations of Ca(2+) handling seem...... to be responsible for the pathophysiological conditions seen in dystrophinopathies, Brody's disease, and malignant hyperthermia. These also underline the importance of the affected molecules for correct muscle performance....

  9. Satellite-like cells contribute to pax7-dependent skeletal muscle repair in adult zebrafish.

    Science.gov (United States)

    Berberoglu, Michael A; Gallagher, Thomas L; Morrow, Zachary T; Talbot, Jared C; Hromowyk, Kimberly J; Tenente, Inês M; Langenau, David M; Amacher, Sharon L

    2017-04-15

    Satellite cells, also known as muscle stem cells, are responsible for skeletal muscle growth and repair in mammals. Pax7 and Pax3 transcription factors are established satellite cell markers required for muscle development and regeneration, and there is great interest in identifying additional factors that regulate satellite cell proliferation, differentiation, and/or skeletal muscle regeneration. Due to the powerful regenerative capacity of many zebrafish tissues, even in adults, we are exploring the regenerative potential of adult zebrafish skeletal muscle. Here, we show that adult zebrafish skeletal muscle contains cells similar to mammalian satellite cells. Adult zebrafish satellite-like cells have dense heterochromatin, express Pax7 and Pax3, proliferate in response to injury, and show peak myogenic responses 4-5 days post-injury (dpi). Furthermore, using a pax7a-driven GFP reporter, we present evidence implicating satellite-like cells as a possible source of new muscle. In lieu of central nucleation, which distinguishes regenerating myofibers in mammals, we describe several characteristics that robustly identify newly-forming myofibers from surrounding fibers in injured adult zebrafish muscle. These characteristics include partially overlapping expression in satellite-like cells and regenerating myofibers of two RNA-binding proteins Rbfox2 and Rbfoxl1, known to regulate embryonic muscle development and function. Finally, by analyzing pax7a; pax7b double mutant zebrafish, we show that Pax7 is required for adult skeletal muscle repair, as it is in the mouse.

  10. 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.

  11. Dissociation of skeletal muscle for flow cytometric characterization of immune cells in macaques.

    Science.gov (United States)

    Liang, Frank; Ploquin, Aurélie; Hernández, José DelaO; Fausther-Bovendo, Hugues; Lindgren, Gustaf; Stanley, Daphne; Martinez, Aiala Salvador; Brenchley, Jason M; Koup, Richard A; Loré, Karin; Sullivan, Nancy J

    2015-10-01

    The majority of vaccines and several treatments are administered by intramuscular injection. The aim is to engage and activate immune cells, although they are rare in normal skeletal muscle. The phenotype and function of resident as well as infiltrating immune cells in the muscle after injection are largely unknown. While methods for obtaining and characterizing murine muscle cell suspensions have been reported, protocols for nonhuman primates (NHPs) have not been well defined. NHPs comprise important in vivo models for studies of immune cell function due to their high degree of resemblance with humans. In this study, we developed and systematically compared methods to collect vaccine-injected muscle tissue to be processed into single cell suspensions for flow cytometric characterization of immune cells. We found that muscle tissue processed by mechanical disruption alone resulted in significantly lower immune cell yields compared to enzymatic digestion using Liberase. Dendritic cell subsets, monocytes, macrophages, neutrophils, B cells, T cells and NK cells were readily detected in the muscle by the classic human markers. The methods for obtaining skeletal muscle cell suspension established here offer opportunities to increase the understanding of immune responses in the muscle, and provide a basis for defining immediate post-injection vaccine responses in primates.

  12. 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.

  13. Robust conversion of marrow cells to skeletal muscle with formation of marrow-derived muscle cell colonies: A multifactorial process

    Energy Technology Data Exchange (ETDEWEB)

    Abedi, Mehrdad; Greer, Deborah A.; Colvin, Gerald A.; Demers, Delia A.; Dooner, Mark S.; Harpel, Jasha A.; Weier, Heinz-Ulrich G.; Lambert, Jean-Francois; Quesenberry, Peter J.

    2004-01-10

    Murine marrow cells are capable of repopulating skeletal muscle fibers. A point of concern has been the robustness of such conversions. We have investigated the impact of type of cell delivery, muscle injury, nature of delivered cell, and stem cell mobilizations on marrow to muscle conversion. We transplanted GFP transgenic marrow into irradiated C57BL/6 mice and then injured anterior tibialis muscle by cardiotoxin. One month after injury, sections were analyzed by standard and deconvolutional microscopy for expression of muscle and hematopietic markers. Irradiation was essential to conversion although whether by injury or induction of chimerism is not clear. Cardiotoxin and to a lesser extent PBS injected muscles showed significant number of GFP+ muscle fibers while uninjected muscles showed only rare GFP+ cells. Marrow conversion to muscle was increased by two cycles of G-CSF mobilization and to a lesser extent with G-CSF and steel or GM-CSF. Transplantation of female GFP to male C57 BL/6 and GFP to Rosa26 mice showed fusion of donor cells to recipient muscle. High numbers of donor derived muscle colonies and up to12 percent GFP positive muscle cells were seen after mobilization or direct injection. These levels of donor muscle chimerism approach levels which could be clinically significant in developing strategies for the treatment of muscular dystrophies. In summary, the conversion of marrow to skeletal muscle cells is based on cell fusion and is critically dependent on injury. This conversion is also numerically significant and increases with mobilization.

  14. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, Steen; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain...... loss from the mitochondria. The results from this study demonstrate that normal mitochondrial functionality is not maintained in cryopreserved human skeletal muscle samples....... functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...

  15. Cryopreservation of human skeletal muscle impairs mitochondrial function

    DEFF Research Database (Denmark)

    Larsen, S; Wright-Paradis, C; Gnaiger, E

    2012-01-01

    Previous studies have investigated if cryopreservation is a viable approach for functional mitochondrial analysis. Different tissues have been studied, and conflicting results have been published. The aim of the present study was to investigate if mitochondria in human skeletal muscle maintain...... functionality after long term cryopreservation (1 year). Skeletal muscle samples were preserved in dimethyl sulfoxide (DMSO) for later analysis. Human skeletal muscle fibres were thawed and permeabilised with saponin, and mitochondrial respiration was measured by high-resolution respirometry. The capacity...... loss from the mitochondria. The results from this study demonstrate that normal mitochondrial functionality is not maintained in cryopreserved human skeletal muscle samples....

  16. Vascular and Skeletal Muscle Function in Gulf War Veterans Illness

    Science.gov (United States)

    2016-07-01

    Page 1 of 14 AWARD NUMBER: W81XWH-15-1-0216 TITLE: Vascular and Skeletal Muscle Function in Gulf War Veterans Illness PRINCIPAL INVESTIGATOR...30 Jun 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Vascular and Skeletal Muscle Function in Gulf War Veterans Illness 5b. GRANT NUMBER 5c...cholinesterases and acetylcholine, which could affect activity at the neuromuscular junction of skeletal muscle, muscarinic receptors affecting vascular smooth

  17. E2F function in muscle growth is necessary and sufficient for viability in Drosophila.

    Science.gov (United States)

    Zappia, Maria Paula; Frolov, Maxim V

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells.

  18. E2F function in muscle growth is necessary and sufficient for viability in Drosophila

    Science.gov (United States)

    Zappia, Maria Paula; Frolov, Maxim V.

    2016-01-01

    The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

  19. The adaptative response of jaw muscles to varying functional demands

    NARCIS (Netherlands)

    Grünheid, T.; Langenbach, G.E.J.; Korfage, J.A.M.; Zentner, A.; van Eijden, T.M.G.J.

    2009-01-01

    Jaw muscles are versatile entities that are able to adapt their anatomical characteristics, such as size, cross-sectional area, and fibre properties, to altered functional demands. The dynamic nature of muscle fibres allows them to change their phenotype to optimize the required contractile function

  20. Functional and structural adaptations of skeletal muscle to microgravity

    Science.gov (United States)

    Fitts, R. H.; Riley, D. R.; Widrick, J. J.

    2001-01-01

    Our purpose is to summarize the major effects of space travel on skeletal muscle with particular emphasis on factors that alter function. The primary deleterious changes are muscle atrophy and the associated decline in peak force and power. Studies on both rats and humans demonstrate a rapid loss of cell mass with microgravity. In rats, a reduction in muscle mass of up to 37% was observed within 1 week. For both species, the antigravity soleus muscle showed greater atrophy than the fast-twitch gastrocnemius. However, in the rat, the slow type I fibers atrophied more than the fast type II fibers, while in humans, the fast type II fibers were at least as susceptible to space-induced atrophy as the slow fiber type. Space flight also resulted in a significant decline in peak force. For example, the maximal voluntary contraction of the human plantar flexor muscles declined by 20-48% following 6 months in space, while a 21% decline in the peak force of the soleus type I fibers was observed after a 17-day shuttle flight. The reduced force can be attributed both to muscle atrophy and to a selective loss of contractile protein. The former was the primary cause because, when force was expressed per cross-sectional area (kNm(-2)), the human fast type II and slow type I fibers of the soleus showed no change and a 4% decrease in force, respectively. Microgravity has been shown to increase the shortening velocity of the plantar flexors. This increase can be attributed both to an elevated maximal shortening velocity (V(0)) of the individual slow and fast fibers and to an increased expression of fibers containing fast myosin. Although the cause of the former is unknown, it might result from the selective loss of the thin filament actin and an associated decline in the internal drag during cross-bridge cycling. Despite the increase in fiber V(0), peak power of the slow type I fiber was reduced following space flight. The decreased power was a direct result of the reduced force

  1. Assessment of isokinetic muscle function in Korea male volleyball athletes

    Science.gov (United States)

    Kim, Chang-Gyun; Jeoung, Bog Ja

    2016-01-01

    Volleyball players performed numerous repetitions of spike actions, which uses and requires strong and explosive force, and control of the muscles of the shoulder, lower back, and legs. Muscle imbalance is one of the main causes of sport injuries. The purpose of this study was to assess isokinetic muscle functions in male volleyball players. We thus aim to accurately evaluate their muscle functions, and identify the best training strategy to achieve optimal muscle strength balance in future training programs. The participants in this study consisted of 14 male volleyball players. Muscle strength was measured using the isokinetic dynamometer. Muscle strength was evaluated in terms of peak torque and average power, calculated from five repeated measurements at an angular speed of 60°/sec. Three players who were left attackers showed shoulder imbalance, four players showed trunk joint imbalance, nine players had knee joint of extension/flexion imbalance and four players showed left/right imbalance. The results showed that the number of volleyball players with differences between the strength of the bilateral knee muscles, and between the strength of the hamstrings and quadriceps muscles was higher than the number of players with differences between the strength of the shoulder internal and external rotation muscles, and higher than the number of players with differences between the strength of the lower back extension and flexion muscles. PMID:27807521

  2. In situ regeneration of skeletal muscle tissue through host cell recruitment.

    Science.gov (United States)

    Ju, Young Min; Atala, Anthony; Yoo, James J; Lee, Sang Jin

    2014-10-01

    Standard reconstructive procedures for restoring normal function after skeletal muscle defects involve the use of existing host tissues such as muscular flaps. In many instances, this approach is not feasible and delays the rehabilitation process and restoration of tissue function. Currently, cell-based tissue engineering strategies have been used for reconstruction; however, donor tissue biopsy and ex vivo cell manipulation are required prior to implantation. The present study aimed to overcome these limitations by demonstrating mobilization of muscle cells into a target-specific site for in situ muscle regeneration. First, we investigated whether host muscle cells could be mobilized into an implanted scaffold. Poly(l-lactic acid) (PLLA) scaffolds were implanted in the tibialis anterior (TA) muscle of rats, and the retrieved scaffolds were characterized by examining host cell infiltration in the scaffolds. The host cell infiltrates, including Pax7+ cells, gradually increased with time. Second, we demonstrated that host muscle cells could be enriched by a myogenic factor released from the scaffolds. Gelatin-based scaffolds containing a myogenic factor were implanted in the TA muscle of rats, and the Pax7+ cell infiltration and newly formed muscle fibers were examined. By the second week after implantation, the Pax7+ cell infiltrates and muscle formation were significantly accelerated within the scaffolds containing insulin-like growth factor 1 (IGF-1). Our data suggest an ability of host stem cells to be recruited into the scaffolds with the capability of differentiating to muscle cells. In addition, the myogenic factor effectively promoted host cell recruitment, which resulted in accelerating muscle regeneration in situ.

  3. Effect of pelvic floor muscle exercises on pulmonary function

    Science.gov (United States)

    Han, DongWook; Ha, Misook

    2015-01-01

    [Purpose] This study aimed to determine the correlation between pelvic floor muscle strength and pulmonary function. In particular, we examined whether pelvic floor muscle exercises can improve pulmonary function. [Subjects] Thirty female college students aged 19–21 with no history of nervous or musculoskeletal system injury were randomly divided into experimental and control groups. [Methods] For the pulmonary function test, spirometry items included forced vital capacity and maximal voluntary ventilation. Pelvic floor muscle exercises consisted of Kegel exercises performed three times daily for 4 weeks. [Results] Kegel exercises performed in the experimental group significantly improved forced vital capacity, forced expiratory volume in 1 second, PER, FEF 25–75%, IC, and maximum voluntary ventilation compared to no improvement in the control group. [Conclusion] Kegel exercises significantly improved pulmonary function. When abdominal pressure increased, pelvic floor muscles performed contraction at the same time. Therefore, we recommend that the use of pelvic floor muscle exercises be considered for improving pulmonary function. PMID:26644681

  4. Functional muscle ischemia in Duchenne and Becker muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Gail D Thomas

    2013-12-01

    Full Text Available Duchenne and Becker muscular dystrophy (DMD/BMD comprise a spectrum of devastating X-linked muscle wasting disease for which there is no treatment. DMD/BMD is caused by mutations in the gene encoding dystrophin, a cytoskeletal protein that stabilizes the muscle membrane and also targets other proteins to the sarcolemma. Among these is the muscle-specific isoform of neuronal nitric oxide synthase (nNOSµ which binds spectrin-like repeats within dystrophin’s rod domain and the adaptor protein α-syntrophin. Dystrophin deficiency causes loss of sarcolemmal nNOSµ and reduces paracrine signaling of muscle-derived nitric oxide (NO to the microvasculature, which renders the diseased muscle fibers susceptible to functional muscle ischemia during exercise. Repeated bouts of functional ischemia superimposed on muscle fibers already weakened by dystrophin deficiency result in use-dependent focal muscle injury. Genetic and pharmacologic strategies to boost nNOSµ-NO signaling in dystrophic muscle alleviate functional muscle ischemia and show promise as novel therapeutic interventions for the treatment of DMD/BMD.

  5. Skeletal Muscle Function Deficits in the Elderly: Current Perspectives on Resistance Training

    Science.gov (United States)

    Papa, Evan V.; Dong, Xiaoyang; Hassan, Mahdi

    2017-01-01

    A variety of changes in skeletal muscle occur with aging. Sarcopenia is the age-associated loss of muscle mass and is one of the main contributors to musculoskeletal impairments in the elderly. Traditional definitions of sarcopenia focused on the size of human skeletal muscle. However, increasing evidence in older adults suggests that low muscle mass is associated with weakness, and weakness is strongly associated with function and disability. In recent years a global trend has shifted toward more encompassing definitions for the loss of muscle mass which include decreases in physical function. This review focuses on skeletal muscle function deficits in the elderly and how these age-associated deficits can be ameliorated by resistance training. We set forth evidence that skeletal muscle deficits arise from changes within the muscle, including reduced fiber size, decreased satellite cell and fiber numbers, and decreased expression of myosin heavy chain (MHC) isoform IIa. Finally, we provide recommendations for clinical geriatric practice regarding how resistance training can attenuate the increase in age-associated skeletal muscle function deficits. Practitioners should consider encouraging patients who are reluctant to exercise to move along a continuum of activity between “no acticity” on one end and “recommended daily amounts” on the other. PMID:28191501

  6. Muscle side population cells from dystrophic or injured muscle adopt a fibro-adipogenic fate.

    Directory of Open Access Journals (Sweden)

    Christopher M Penton

    Full Text Available Muscle side population (SP cells are rare multipotent stem cells that can participate in myogenesis and muscle regeneration upon transplantation. While they have been primarily studied for the development of cell-based therapies for Duchenne muscular dystrophy, little is known regarding their non-muscle lineage choices or whether the dystrophic muscle environment affects their ability to repair muscle. Unfortunately, the study of muscle SP cells has been challenged by their low abundance and the absence of specific SP cell markers. To address these issues, we developed culture conditions for the propagation and spontaneous multi-lineage differentiation of muscle SP cells. Using this approach, we show that SP cells from wild type muscle robustly differentiate into satellite cells and form myotubes without requiring co-culture with myogenic cells. Furthermore, this myogenic activity is associated with SP cells negative for immune (CD45 and vascular (CD31 markers but positive for Pax7, Sca1, and the mesenchymal progenitor marker PDGFRα. Additionally, our studies revealed that SP cells isolated from dystrophic or cardiotoxin-injured muscle fail to undergo myogenesis. Instead, these SP cells rapidly expand giving rise to fibroblast and adipocyte progenitors (FAPs and to their differentiated progeny, fibroblasts and adipocytes. Our findings indicate that muscle damage affects the lineage choices of muscle SP cells, promoting their differentiation along fibro-adipogenic lineages while inhibiting myogenesis. These results have implications for a possible role of muscle SP cells in fibrosis and fat deposition in muscular dystrophy. In addition, our studies provide a useful in vitro system to analyze SP cell biology in both normal and pathological conditions.

  7. Evaluating Swallowing Muscles Essential for Hyolaryngeal Elevation by Using Muscle Functional Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, William G., E-mail: bp1@bu.edu [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States); Hindson, David F. [Department of Radiology, Boston Medical Center, Boston, Massachusetts (United States); Langmore, Susan E. [Department of Otolaryngology, Boston Medical Center, Boston, Massachusetts (United States); Speech and Hearing Sciences, Boston University, Boston, Massachusetts (United States); Zumwalt, Ann C. [Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts (United States)

    2013-03-01

    Purpose: Reduced hyolaryngeal elevation, a critical event in swallowing, is associated with radiation therapy. Two muscle groups that suspend the hyoid, larynx, and pharynx have been proposed to elevate the hyolaryngeal complex: the suprahyoid and longitudinal pharyngeal muscles. Thought to assist both groups is the thyrohyoid, a muscle intrinsic to the hyolaryngeal complex. Intensity modulated radiation therapy guidelines designed to preserve structures important to swallowing currently exclude the suprahyoid and thyrohyoid muscles. This study used muscle functional magnetic resonance imaging (mfMRI) in normal healthy adults to determine whether both muscle groups are active in swallowing and to test therapeutic exercises thought to be specific to hyolaryngeal elevation. Methods and Materials: mfMRI data were acquired from 11 healthy subjects before and after normal swallowing and after swallowing exercise regimens (the Mendelsohn maneuver and effortful pitch glide). Whole-muscle transverse relaxation time (T2 signal, measured in milliseconds) profiles of 7 test muscles were used to evaluate the physiologic response of each muscle to each condition. Changes in effect size (using the Cohen d measure) of whole-muscle T2 profiles were used to determine which muscles underlie swallowing and swallowing exercises. Results: Post-swallowing effect size changes (where a d value of >0.20 indicates significant activity during swallowing) for the T2 signal profile of the thyrohyoid was a d value of 0.09; a d value of 0.40 for the mylohyoid, 0.80 for the geniohyoid, 0.04 for the anterior digastric, and 0.25 for the posterior digastric-stylohyoid in the suprahyoid muscle group; and d values of 0.47 for the palatopharyngeus and 0.28 for the stylopharyngeus muscles in the longitudinal pharyngeal muscle group. The Mendelsohn maneuver and effortful pitch glide swallowing exercises showed significant effect size changes for all muscles tested, except for the thyrohyoid. Conclusions

  8. Isolation, Culture and Identification of Porcine Skeletal Muscle Satellite Cells

    Directory of Open Access Journals (Sweden)

    Bo-jiang Li

    2015-08-01

    Full Text Available The objective of this study was to establish the optimum protocol for the isolation and culture of porcine muscle satellite cells. Mononuclear muscle satellite cells are a kind of adult stem cell, which is located between the basal lamina and sarcolemma of muscle fibers and is the primary source of myogenic precursor cells in postnatal muscle. Muscle satellite cells are a useful model to investigate the mechanisms of muscle growth and development. Although the isolation and culture protocols of muscle satellite cells in some species (e.g. mouse have been established successfully, the culture system for porcine muscle satellite cells is very limited. In this study, we optimized the isolation procedure of porcine muscle satellite cells and elaborated the isolation and culture process in detail. Furthermore, we characterized the porcine muscle satellite cells using the immunofluorecence. Our study provides a reference for the isolation of porcine muscle satellite cells and will be useful for studying the molecular mechanisms in these cells.

  9. Postural and ventilatory functions of intercostal muscles.

    Science.gov (United States)

    Duron, B

    1973-01-01

    During spontaneous breathing, the interchondral muscles present a pattern of activity similar to that of the diaphragm. The external intercostals and most of the internal intercostals generally show electrical discharges not related to ventilatory rhythm. Studies of the electrical responses of these muscles in experimental variations of their length show that the external and internal intercostals are readily activated by this category of reflexes while the diaphragm and the interchondrals are not. Bilateral multisegmental sections of spinal dorsal roots do not affect the respiratory activity of the diaphragm and of the interchondral muscles; on the contrary, all types of activity - spontaneous or reflex - disappear from the intercostals. Electrical stimulation of appropriate points in the bulbar pyramids in decerebrate cats can activate at the same time different intercostals and leg muscles without modifying the rhythmic inspiratory activity of the diaphragm and the interchondrals. In preparations with chronically implanted electrodes, the intercostals muscles are chiefly involved in posture. These results fit very well with our histological findings which disclose a much greater density of muscle spindles in external intercostals than in the diaphragm or in the interchondral muscles.

  10. 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 Wnt/beta-ca

  11. The interosseous muscles: the foundation of hand function.

    Science.gov (United States)

    Liss, Frederic E

    2012-02-01

    The interosseous muscles of the hand can be thought of as the cornerstone of hand function, as they provide a "foundation" for all intrinsic and extrinsic hand movements. Innervated by the ulnar nerve and organized in dorsal and palmar layers, these pivotal muscles have small excursion yet great impact on finger balance, grip, and pinch function, particularly when impaired by denervation and/or contracture. This article gives an overview of the functional anatomy and pathologic dysfunction of the interosseous muscles within the context of this Hand Clinics issue on the intrinsic muscular function of the hand. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Skeletal muscle microvascular function in girls with Turner syndrome

    OpenAIRE

    West, Sarah L.; Clodagh S. O'Gorman; Alyaa H. Elzibak; Jessica Caterini; Noseworthy, Michael D; Tammy Rayner; Jill Hamilton; Wells, Greg D.

    2014-01-01

    Background: Exercise intolerance is prevalent in individuals with Turner Syndrome (TS). We recently demonstrated that girls with TS have normal aerobic but altered skeletal muscle anaerobic metabolism compared to healthy controls (HC). The purpose of this study was to compare peripheral skeletal muscle microvascular function in girls with TS to HC after exercise. We hypothesized that girls with TS would have similar muscle blood-oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) s...

  13. Muscle mass and function after total hip arthroplasty

    OpenAIRE

    Rasch, Anton

    2009-01-01

    Osteoarthritis (OA) of the hip is a common disease among elderly causing pain, joint stiffness and reduced mobility. Outcome studies have shown total hip arthroplasy (THA) to be a successful surgical procedure. Studies of muscle strength and function after THA are more scarce and results vary. It has been suggested that unloading of the OA limb due to pain, results in hip and thigh muscle weakness and atrophy causing an abnormal gait and impaired postural control. Muscle atr...

  14. Functional Compartmentalization of the Human Superficial Masseter Muscle

    OpenAIRE

    Guzmán-Venegas, Rodrigo A.; Biotti Picand, Jorge L.; Francisco J Berral de la Rosa

    2015-01-01

    Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM) muscle's motor units using high-density surface e...

  15. Deficient leukemia inhibitory factor signaling in muscle precursor cells from patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Broholm, Christa; Brandt, Claus; Schultz, Ninna S

    2012-01-01

    The cytokine leukemia-inhibitory factor (LIF) is expressed by skeletal muscle and induces proliferation of muscle precursor cells, an important feature of skeletal muscle maintenance and repair. We hypothesized that muscle precursor cells from patients with type 2 diabetes had a deficient response......-stimulated cell proliferation and a decreased LIF-stimulated induction of the proliferation-promoting factors cyclin D1, JunB, and c-myc. SOCS3 protein was upregulated in diabetic myoblasts, and knockdown of SOCS3 rescued LIF-induced gene expression in diabetic myoblasts, whereas neither STAT1 or STAT3 signaling...... nor proliferation rate was affected. In conclusion, although LIF and LIFR proteins were increased in muscle tissue and myoblasts from diabetic patients, LIF signaling and LIF-stimulated cell proliferation were impaired in diabetic myoblasts, suggesting a novel mechanism by which muscle function...

  16. The adaptive response of jaw muscles to varying functional demands.

    Science.gov (United States)

    Grünheid, Thorsten; Langenbach, Geerling E J; Korfage, Joannes A M; Zentner, Andrej; van Eijden, Theo M G J

    2009-12-01

    Jaw muscles are versatile entities that are able to adapt their anatomical characteristics, such as size, cross-sectional area, and fibre properties, to altered functional demands. The dynamic nature of muscle fibres allows them to change their phenotype to optimize the required contractile function while minimizing energy use. Changes in these anatomical parameters are associated with changes in neuromuscular activity as the pattern of muscle activation by the central nervous system plays an important role in the modulation of muscle properties. This review summarizes the adaptive response of jaw muscles to various stimuli or perturbations in the orofacial system and addresses general changes in muscles as they adapt, specific adaptive changes in jaw muscles under various physiologic and pathologic conditions, and their adaptive response to non-surgical and surgical therapeutic interventions. Although the jaw muscles are used concertedly in the masticatory system, their adaptive changes are not always uniform and vary with the nature, intensity, and duration of the stimulus. In general, stretch, increases neuromuscular activity, and resistance training result in hypertrophy, elicits increases in mitochondrial content and cross-sectional area of the fibres, and may change the fibre-type composition of the muscle towards a larger percentage of slow-type fibres. In contrast, changes in the opposite direction occur when neuromuscular activity is reduced, the muscle is immobilized in a shortened position, or paralysed. The broad range of stimuli that affect the properties of jaw muscles might help explain the large variability in the anatomical and physiological characteristics found among individuals, muscles, and muscle portions.

  17. Receptor Expression in Rat Skeletal Muscle Cell Cultures

    Science.gov (United States)

    Young, Ronald B.

    1996-01-01

    One on the most persistent problems with long-term space flight is atrophy of skeletal muscles. Skeletal muscle is unique as a tissue in the body in that its ability to undergo atrophy or hypertrophy is controlled exclusively by cues from the extracellular environment. The mechanism of communication between muscle cells and their environment is through a group of membrane-bound and soluble receptors, each of which carries out unique, but often interrelated, functions. The primary receptors include acetyl choline receptors, beta-adrenergic receptors, glucocorticoid receptors, insulin receptors, growth hormone (i.e., somatotropin) receptors, insulin-like growth factor receptors, and steroid receptors. This project has been initiated to develop an integrated approach toward muscle atrophy and hypertrophy that takes into account information on the populations of the entire group of receptors (and their respective hormone concentrations), and it is hypothesized that this information can form the basis for a predictive computer model for muscle atrophy and hypertrophy. The conceptual basis for this project is illustrated in the figure below. The individual receptors are shown as membrane-bound, with the exception of the glucocorticoid receptor which is a soluble intracellular receptor. Each of these receptors has an extracellular signalling component (e.g., innervation, glucocorticoids, epinephrine, etc.), and following the interaction of the extracellular component with the receptor itself, an intracellular signal is generated. Each of these intracellular signals is unique in its own way; however, they are often interrelated.

  18. Electric pulse stimulation of cultured murine muscle cells reproduces gene expression changes of trained mouse muscle.

    Directory of Open Access Journals (Sweden)

    Nathalie Burch

    Full Text Available Adequate levels of physical activity are at the center of a healthy lifestyle. However, the molecular mechanisms that mediate the beneficial effects of exercise remain enigmatic. This gap in knowledge is caused by the lack of an amenable experimental model system. Therefore, we optimized electric pulse stimulation of muscle cells to closely recapitulate the plastic changes in gene expression observed in a trained skeletal muscle. The exact experimental conditions were established using the peroxisome proliferator-activated receptor gamma coactivator 1alpha (PGC-1alpha as a marker for an endurance-trained muscle fiber. We subsequently compared the changes in the relative expression of metabolic and myofibrillar genes in the muscle cell system with those observed in mouse muscle in vivo following either an acute or repeated bouts of treadmill exercise. Importantly, in electrically stimulated C2C12 mouse muscle cells, the qualitative transcriptional adaptations were almost identical to those in trained muscle, but differ from the acute effects of exercise on muscle gene expression. In addition, significant alterations in the expression of myofibrillar proteins indicate that this stimulation could be used to modulate the fiber-type of muscle cells in culture. Our data thus describe an experimental cell culture model for the study of at least some of the transcriptional aspects of skeletal muscle adaptation to physical activity. This system will be useful for the study of the molecular mechanisms that regulate exercise adaptation in muscle.

  19. Botox produces functional weakness in non-injected muscles adjacent to the target muscle.

    Science.gov (United States)

    Yaraskavitch, M; Leonard, T; Herzog, Walter

    2008-01-01

    Botulinum type-A (BTX-A) neurotoxin exerts a paralytic effect on muscles and is used increasingly to treat a variety of muscle spasticity disorders. While its pathogenesis for muscle-induced weakness has been well elucidated, the functional effects of BTX-A administration are incomplete. Specifically, weakness as a function of muscle length and stimulation frequency has only been investigated qualitatively in a few muscles and the possible effect of the toxin on non-target muscles, although considered possible based on laboratory experiments, has not been studied widely and the functional implications remain unknown. Therefore, the purpose of this study was to measure the functional implications of BTX-A on force production and possible weakness of a target muscle and a non-injected neighbouring muscle. The cat soleus was chosen as the target muscle and was injected with 3.2-3.5U of BTX-A/kg in one hind limb, while the soleus of the other hind limb served as a non-injected control. Force-length properties within and exceeding the functional range of motion were determined at frequencies of stimulation of 10, 30 and 50Hz. Force-length properties of the adjacent non-injected plantaris were also determined in the experimental and contralateral hind limb. Four weeks following BTX-A injections, peak soleus forces were decreased by 30% (50Hz), 29% (30Hz) and 29% (10Hz) and peak plantaris forces were decreased by 11% (50Hz), 16% (30Hz) and 16% (10Hz), in the experimental compared to the contralateral hind limb. Absolute BTX-associated force loss was significantly different at all frequencies of stimulation and all lengths for the soleus, while in the plantaris there was a significant force loss across long (> or = -4mm) but not short muscle lengths. Decreases in peak force were independent of the stimulation frequency. We concluded from the results of this study that BTX-A injection in the target muscle caused a measurable effect on force production and that force

  20. Effects of delayed-onset muscle soreness on masticatory function

    NARCIS (Netherlands)

    Yoshida, E.; Lobbezoo, F.; Fueki, K.; Naeije, M.

    2012-01-01

    The aim was to clarify the effects of experimentally provoked delayed-onset muscle soreness (DOMS) in the jaw-closing muscles on subjective and objective measures of masticatory function. Twenty-one dentate female subjects, without pain-related signs and symptoms of temporomandibular disorders, part

  1. Muscle function and origin of pain in fibromyalgia

    DEFF Research Database (Denmark)

    Bennett, R M; Jacobsen, Søren

    1994-01-01

    It may be concluded that both peripheral and central mechanisms may operate in the pathophysiology of both impaired muscle function and pain in FM. These mechanisms may in part be attributable to physical deconditioning and disuse of muscle secondary to the characteristic pain and fatigue so ofte...

  2. Pelvic floor muscle function in women with pelvic floor dysfunction

    DEFF Research Database (Denmark)

    Tibaek, Sigrid; Dehlendorff, Christian

    2014-01-01

    The objectives of this study were to investigate the level of pelvic floor muscle (PFM) function in women with pelvic floor dysfunction (PFD) referred by gynaecologists and urologists for in-hospital pelvic floor muscle training (PFMT), and to identity associated factors for a low level of PFM fu...

  3. 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.

  4. 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.

  5. AMPKγ3 is dispensable for skeletal muscle hypertrophy induced by functional overload.

    Science.gov (United States)

    Riedl, Isabelle; Osler, Megan E; Björnholm, Marie; Egan, Brendan; Nader, Gustavo A; Chibalin, Alexander V; Zierath, Juleen R

    2016-03-15

    Mechanisms regulating skeletal muscle growth involve a balance between the activity of serine/threonine protein kinases, including the mammalian target of rapamycin (mTOR) and 5'-AMP-activated protein kinase (AMPK). The contribution of different AMPK subunits to the regulation of cell growth size remains inadequately characterized. Using AMPKγ3 mutant-overexpressing transgenic Tg-Prkag3(225Q) and AMPKγ3-knockout (Prkag3(-/-)) mice, we investigated the requirement for the AMPKγ3 isoform in functional overload-induced muscle hypertrophy. Although the genetic disruption of the γ3 isoform did not impair muscle growth, control sham-operated AMPKγ3-transgenic mice displayed heavier plantaris muscles in response to overload hypertrophy and underwent smaller mass gain and lower Igf1 expression compared with wild-type littermates. The mTOR signaling pathway was upregulated with functional overload but unchanged between genetically modified animals and wild-type littermates. Differences in AMPK-related signaling pathways between transgenic, knockout, and wild-type mice did not impact muscle hypertrophy. Glycogen content was increased following overload in wild-type mice. In conclusion, our functional, transcriptional, and signaling data provide evidence against the involvement of the AMPKγ3 isoform in the regulation of skeletal muscle hypertrophy. Thus, the AMPKγ3 isoform is dispensable for functional overload-induced muscle growth. Mechanical loading can override signaling pathways that act as negative effectors of mTOR signaling and consequently promote skeletal muscle hypertrophy. Copyright © 2016 the American Physiological Society.

  6. Functional sparing of intrafusal muscle fibers in muscular dystrophies.

    Science.gov (United States)

    Aimonetti, Jean-Marc; Ribot-Ciscar, Edith; Rossi-Durand, Christiane; Attarian, Shahram; Pouget, Jean; Roll, Jean-Pierre

    2005-07-01

    In a previous study, we showed that patients with muscular dystrophies (MDs) perceive passive movements, experience sensations of illusory movement induced by muscle tendon vibration, and have proprioceptive-regulated sways in response to vibratory stimulation applied to the neck and ankle muscle tendons. These findings argue for preserved proprioceptive functions of muscle spindles. However, it is unclear whether the function of intrafusal muscle fibers is spared, i.e., whether they retain their ability to contract when submitted to a fusimotor drive. To answer this question, we analyzed the effects of reinforcement maneuvers (mental computation and the Jendrassik maneuver) that are known to increase muscle spindle sensitivity via fusimotor drive in healthy subjects. Nine patients with different MDs participated in the study. Reinforcement maneuvers increased both the mean amplitude of the Achilles tendon reflex (187 +/- 52.9% of the mean control amplitude) and the sensitivity of muscle spindle afferents to imposed movements of the ankle. The same reinforcement maneuvers failed to alter the amplitude of the Hoffmann reflex in the triceps surae muscle. These results suggest that the intrafusal muscle fibers preserve their contractile abilities in slowly progressive MDs. The reasons for a differential impairment of intrafusal and extrafusal muscle fibers and the clinical implications of the present results are discussed.

  7. The transcription factor TEAD1 represses smooth muscle-specific gene expression by abolishing myocardin function.

    Science.gov (United States)

    Liu, Fang; Wang, Xiaobo; Hu, Guoqing; Wang, Yong; Zhou, Jiliang

    2014-02-07

    The TEAD (transcriptional enhancer activator domain) proteins share an evolutionarily conserved DNA-binding TEA domain, which binds to the MCAT cis-acting regulatory element. Previous studies have shown that TEAD proteins are involved in regulating the expression of smooth muscle α-actin. However, it remains undetermined whether TEAD proteins play a broader role in regulating expression of other genes in vascular smooth muscle cells. In this study, we show that the expression of TEAD1 is significantly induced during smooth muscle cell phenotypic modulation and negatively correlates with smooth muscle-specific gene expression. We further demonstrate that TEAD1 plays a novel role in suppressing expression of smooth muscle-specific genes, including smooth muscle α-actin, by abolishing the promyogenic function of myocardin, a key mediator of smooth muscle differentiation. Mechanistically, we found that TEAD1 competes with myocardin for binding to serum response factor (SRF), resulting in disruption of myocardin and SRF interactions and thereby attenuating expression of smooth muscle-specific genes. This study provides the first evidence demonstrating that TEAD1 is a novel general repressor of smooth muscle-specific gene expression through interfering with myocardin binding to SRF.

  8. 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.

  9. Signaling pathways in failing human heart muscle cells.

    Science.gov (United States)

    Drexler, H; Hasenfuss, G; Holubarsch, C

    1997-07-01

    Experimental studies have delineated important signaling pathways in cardiomyocytes and their alterations in heart failure; however, there is now evidence that these observations are not necessarily applicable to human cardiac muscle cells. For example, angiotensin II (A II) does not exert positive inotropic effects in human ventricular muscle cells, in contrast to observation in rats. Thus, it is important to elucidate cardiac signaling pathways in humans in order to appreciate the functional role of neurohumoral or mechanical stimulation in human myocardium in health and disease. In the present article, we review signal pathways in the failing human heart based on studies in human cardiac tissues and in vivo physiological studies related to A II, nitric oxide, and β-adrenergic stimulation. (Trends Cardiovasc Med 1997; 7:151-160). © 1997, Elsevier Science Inc.

  10. Muscle fibers in the central nervous system of nemerteans: spatial organization and functional role.

    Science.gov (United States)

    Petrov, A A; Zaitseva, O V

    2012-08-01

    The system of muscle fibers associated with the brain and lateral nerve cords is present in all major groups of enoplan nemerteans. Unfortunately, very little is known about the functional role and spatial arrangement of these muscles of the central nervous system. This article examines the architecture of the musculature of the central nervous system in two species of monostiliferous nemerteans (Emplectonema gracile and Tetrastemma cf. candidum) using phalloidin staining and confocal microscopy. The article also briefly discusses the body-wall musculature and the muscles of the cephalic region. In both species, the lateral nerve cords possess two pairs of cardinal muscles that run the length of the nerve cords and pass through the ventral cerebral ganglia. A system of peripheral muscles forms a meshwork around the lateral nerve cords in E. gracile. The actin-rich processes that ramify within the nerve cords in E. gracile (transverse fibers) might represent a separate population of glia-like cells or sarcoplasmic projections of the peripheral muscles of the central nervous system. The lateral nerve cords in T. cf. candidum lack peripheral muscles but have muscles similar in their position and orientation to the transverse fibers. The musculature of the central nervous system is hypothesized to function as a support system for the lateral nerve cords and brain, preventing rupturing and herniation of the nervous tissue during locomotion. The occurrence of muscles of the central nervous system in nemerteans and other groups and their possible relevance in taxonomy are discussed.

  11. Muscle cells and motoneurons differentially remove mutant SOD1 causing familial amyotrophic lateral sclerosis.

    Science.gov (United States)

    Onesto, Elisa; Rusmini, Paola; Crippa, Valeria; Ferri, Nicola; Zito, Arianna; Galbiati, Mariarita; Poletti, Angelo

    2011-07-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motoneuronal disease which occurs in sporadic or familial forms, clinically indistinguishable. About 15% of familial ALS cases are linked to mutations of the superoxide dismutase 1 (SOD1) gene that may induce misfolding in the coded protein, exerting neurotoxicity to motoneurons. However, other cell types might be target of SOD1 toxicity, because muscle-restricted expression of mutant SOD1 correlates with muscle atrophy and motoneurons death. We analysed the molecular behaviour of mutant SOD1 in motoneuronal NSC34 and muscle C2C12 cells. We found that misfolded mutant SOD1 clearance is much more efficient in muscle C2C12 than in motoneuronal NSC34 cells. Mutant SOD1 forms aggregates and impairs the proteasome only in motoneuronal NSC34 cells. Interestingly, NSC34 cells expressing mutant SOD1 are more sensitive to a superoxide-induced oxidative stress. Moreover, in muscle C2C12 cells mutant SOD1 remains soluble even when proteasome is inhibited with MG132. The higher mutant SOD1 clearance in muscle cells correlates with a more efficient proteasome activity, combined with a robust autophagy activation. Therefore, muscle cells seem to better manage misfolded SOD1 species, not because of an intrinsic property of the mutant protein, but in function of the cell environment, indicating also that the SOD1 toxicity at muscle level may not directly depend on its aggregation rate. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

  12. Rules of tissue packing involving different cell types: human muscle organization.

    Science.gov (United States)

    Sánchez-Gutiérrez, Daniel; Sáez, Aurora; Gómez-Gálvez, Pedro; Paradas, Carmen; Escudero, Luis M

    2017-01-10

    Natural packed tissues are assembled as tessellations of polygonal cells. These include skeletal muscles and epithelial sheets. Skeletal muscles appear as a mosaic composed of two different types of cells: the "slow" and "fast" fibres. Their relative distribution is important for the muscle function but little is known about how the fibre arrangement is established and maintained. In this work we capture the organizational pattern in two different healthy muscles: biceps brachii and quadriceps. Here we show that the biceps brachii muscle presents a particular arrangement, based on the different sizes of slow and fast fibres. By contrast, in the quadriceps muscle an unbiased distribution exists. Our results indicate that the relative size of each cellular type imposes an intrinsic organization into natural tessellations. These findings establish a new framework for the analysis of any packed tissue where two or more cell types exist.

  13. [The effect of prostatilen on the contractile activity of the smooth-muscle cells of the blood vessels and bladder in cats].

    Science.gov (United States)

    al-Shchukri, S Kh; Barabanov, S V; Barabanova, V V; Bobkov, Iu A; Gorbachev, A G; Parastaeva, M M

    1996-07-01

    Prostatilene enhanced the functional activity of the bladder and blood vessels' smooth muscle cells. A possibility of activation of the smooth muscle cells contractility with prostatilene by a pharmaco-mechanical association, is discussed.

  14. Smooth Muscle Precursor Cells Derived from Human Pluripotent Stem Cells for Treatment of Stress Urinary Incontinence

    Science.gov (United States)

    Wang, Zhe; Li, Yan Hui; Wei, Yi; Green, Morgaine; Wani, Prachi; Zhang, Pengbo; Pera, Renee Reijo; Chen, Bertha

    2016-01-01

    There is great interest in using stem cells (SC) to regenerate a deficient urethral sphincter in patients with urinary incontinence. The smooth muscle component of the sphincter is a significant contributor to sphincter function. However, current translational efforts for sphincter muscle restoration focus only on skeletal muscle regeneration because they rely on adult mesenchymal SC as cell source. These adult SC do not yield sufficient smooth muscle cells (SMCs) for transplantation. We may be able to overcome this limitation by using pluripotent stem cell (PSC) to derive SMCs. Hence, we sought to investigate whether smooth muscle precursor cells (pSMCs) derived from human PSCs can restore urethral function in an animal model generated by surgical urethrolysis and ovariectomy. Rats were divided into four groups: control (no intervention), sham saline (surgery + saline injection), bladder SMC (surgery + human bladder SMC injection), and treatment (surgery + pSMC injection, which includes human embryonic stem cell (hESC) H9-derived pSMC, episomal reprogrammed induced pluripotent stem cells (iPSCs)-derived pSMC, or viral reprogrammed iPSC-derived pSMC). pSMCs (2 × 106 cells/rat) were injected periurethrally 3 weeks postsurgery. Leak point pressure (LPP) and baseline external urethral sphincter electromyography were measured 5 weeks postinjection. Both iPSC-derived pSMC treatment groups showed significantly higher LPP compared to the sham saline group, consistent with restoration of urethral sphincter function. While the difference between the H9-derived pSMC treatment and sham saline group was not significant, it did show a trend toward restoration of the LPP to the level of intact controls. Our data indicate that pSMCs derived from human PSCs (hESC and iPSC) can restore sphincter function. PMID:26785911

  15. Transplantation of Embryonic Spinal Cord Derived Cells Helps to Prevent Muscle Atrophy after Peripheral Nerve Injury.

    Science.gov (United States)

    Ruven, Carolin; Li, Wen; Li, Heng; Wong, Wai-Man; Wu, Wutian

    2017-02-27

    Injuries to peripheral nerves are frequent in serious traumas and spinal cord injuries. In addition to surgical approaches, other interventions, such as cell transplantation, should be considered to keep the muscles in good condition until the axons regenerate. In this study, E14.5 rat embryonic spinal cord fetal cells and cultured neural progenitor cells from different spinal cord segments were injected into transected musculocutaneous nerve of 200-300 g female Sprague Dawley (SD) rats, and atrophy in biceps brachii was assessed. Both kinds of cells were able to survive, extend their axons towards the muscle and form neuromuscular junctions that were functional in electromyographic studies. As a result, muscle endplates were preserved and atrophy was reduced. Furthermore, we observed that the fetal cells had a better effect in reducing the muscle atrophy compared to the pure neural progenitor cells, whereas lumbar cells were more beneficial compared to thoracic and cervical cells. In addition, fetal lumbar cells were used to supplement six weeks delayed surgical repair after the nerve transection. Cell transplantation helped to preserve the muscle endplates, which in turn lead to earlier functional recovery seen in behavioral test and electromyography. In conclusion, we were able to show that embryonic spinal cord derived cells, especially the lumbar fetal cells, are beneficial in the treatment of peripheral nerve injuries due to their ability to prevent the muscle atrophy.

  16. Transplantation of Embryonic Spinal Cord Derived Cells Helps to Prevent Muscle Atrophy after Peripheral Nerve Injury

    Directory of Open Access Journals (Sweden)

    Carolin Ruven

    2017-02-01

    Full Text Available Injuries to peripheral nerves are frequent in serious traumas and spinal cord injuries. In addition to surgical approaches, other interventions, such as cell transplantation, should be considered to keep the muscles in good condition until the axons regenerate. In this study, E14.5 rat embryonic spinal cord fetal cells and cultured neural progenitor cells from different spinal cord segments were injected into transected musculocutaneous nerve of 200–300 g female Sprague Dawley (SD rats, and atrophy in biceps brachii was assessed. Both kinds of cells were able to survive, extend their axons towards the muscle and form neuromuscular junctions that were functional in electromyographic studies. As a result, muscle endplates were preserved and atrophy was reduced. Furthermore, we observed that the fetal cells had a better effect in reducing the muscle atrophy compared to the pure neural progenitor cells, whereas lumbar cells were more beneficial compared to thoracic and cervical cells. In addition, fetal lumbar cells were used to supplement six weeks delayed surgical repair after the nerve transection. Cell transplantation helped to preserve the muscle endplates, which in turn lead to earlier functional recovery seen in behavioral test and electromyography. In conclusion, we were able to show that embryonic spinal cord derived cells, especially the lumbar fetal cells, are beneficial in the treatment of peripheral nerve injuries due to their ability to prevent the muscle atrophy.

  17. Eosinophils induce airway smooth muscle cell proliferation.

    Science.gov (United States)

    Halwani, Rabih; Vazquez-Tello, Alejandro; Sumi, Yuki; Pureza, Mary Angeline; Bahammam, Ahmed; Al-Jahdali, Hamdan; Soussi-Gounni, Abdelillah; Mahboub, Bassam; Al-Muhsen, Saleh; Hamid, Qutayba

    2013-04-01

    Asthma is characterized by eosinophilic airway inflammation and remodeling of the airway wall. Features of airway remodeling include increased airway smooth muscle (ASM) mass. However, little is known about the interaction between inflammatory eosinophils and ASM cells. In this study, we investigated the effect of eosinophils on ASM cell proliferation. Eosinophils were isolated from peripheral blood of mild asthmatics and non-asthmatic subjects and co-cultured with human primary ASM cells. ASM proliferation was estimated using Ki-67 expression assay. The expression of extracellular matrix (ECM) mRNA in ASM cells was measured using quantitative real-time PCR. The role of eosinophil derived Cysteinyl Leukotrienes (CysLTs) in enhancing ASM proliferation was estimated by measuring the release of leukotrienes from eosinophils upon their direct contact with ASM cells using ELISA. This role was confirmed either by blocking eosinophil-ASM contact or co-culturing them in the presence of leukotrienes antagonist. ASM cells co-cultured with eosinophils, isolated from asthmatics, but not non-asthmatics, had a significantly higher rate of proliferation compared to controls. This increase in ASM proliferation was independent of their release of ECM proteins but dependent upon eosinophils release of CysLTs. Eosinophil-ASM cell to cell contact was required for CysLTs release. Preventing eosinophil contact with ASM cells using anti-adhesion molecules antibodies, or blocking the activity of eosinophil derived CysLTs using montelukast inhibited ASM proliferation. Our results indicated that eosinophils contribute to airway remodeling during asthma by enhancing ASM cell proliferation and hence increasing ASM mass. Direct contact of eosinophils with ASM cells triggers their release of CysLTs which enhance ASM proliferation. Eosinophils, and their binding to ASM cells, constitute a potential therapeutic target to interfere with the series of biological events leading to airway remodeling

  18. Functional Echomyography of the human denervated muscle: first results

    Directory of Open Access Journals (Sweden)

    Riccardo Zanato

    2011-03-01

    . The very high energy needed to stimulate the denervated muscles according to the Vienna home-based Functional Electrical Stimulation (h-b FES strategy demonstrates that the explored muscles are denervated. This pilot study confirms the usefulness of Functional EchoMyography in the follow-up and the positive effects of h-b FES of denervated/reinnervating muscles.

  19. Sarcolemmal ATP-sensitive potassium channels modulate skeletal muscle function under low-intensity workloads.

    Science.gov (United States)

    Zhu, Zhiyong; Sierra, Ana; Burnett, Colin M-L; Chen, Biyi; Subbotina, Ekaterina; Koganti, Siva Rama Krishna; Gao, Zhan; Wu, Yuejin; Anderson, Mark E; Song, Long-Sheng; Goldhamer, David J; Coetzee, William A; Hodgson-Zingman, Denice M; Zingman, Leonid V

    2014-01-01

    ATP-sensitive potassium (KATP) channels have the unique ability to adjust membrane excitability and functions in accordance with the metabolic status of the cell. Skeletal muscles are primary sites of activity-related energy consumption and have KATP channels expressed in very high density. Previously, we demonstrated that transgenic mice with skeletal muscle-specific disruption of KATP channel function consume more energy than wild-type littermates. However, how KATP channel activation modulates skeletal muscle resting and action potentials under physiological conditions, particularly low-intensity workloads, and how this can be translated to muscle energy expenditure are yet to be determined. Here, we developed a technique that allows evaluation of skeletal muscle excitability in situ, with minimal disruption of the physiological environment. Isometric twitching of the tibialis anterior muscle at 1 Hz was used as a model of low-intensity physical activity in mice with normal and genetically disrupted KATP channel function. This workload was sufficient to induce KATP channel opening, resulting in membrane hyperpolarization as well as reduction in action potential overshoot and duration. Loss of KATP channel function resulted in increased calcium release and aggravated activity-induced heat production. Thus, this study identifies low-intensity workload as a trigger for opening skeletal muscle KATP channels and establishes that this coupling is important for regulation of myocyte function and thermogenesis. These mechanisms may provide a foundation for novel strategies to combat metabolic derangements when energy conservation or dissipation is required.

  20. Effects of Massage on Delayed-Onset Muscle Soreness, Swelling, and Recovery of Muscle Function

    Science.gov (United States)

    Zainuddin, Zainal; Newton, Mike; Sacco, Paul; Nosaka, Kazunori

    2005-01-01

    Context: Delayed-onset muscle soreness (DOMS) describes muscle pain and tenderness that typically develop several hours postexercise and consist of predominantly eccentric muscle actions, especially if the exercise is unfamiliar. Although DOMS is likely a symptom of eccentric-exercise–induced muscle damage, it does not necessarily reflect muscle damage. Some prophylactic or therapeutic modalities may be effective only for alleviating DOMS, whereas others may enhance recovery of muscle function without affecting DOMS. Objective: To test the hypothesis that massage applied after eccentric exercise would effectively alleviate DOMS without affecting muscle function. Design: We used an arm-to-arm comparison model with 2 independent variables (control and massage) and 6 dependent variables (maximal isometric and isokinetic voluntary strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness). A 2-way repeated-measures analysis of variance and paired t tests were used to examine differences in changes of the dependent variable over time (before, immediately and 30 minutes after exercise, and 1, 2, 3, 4, 7, 10, and 14 days postexercise) between control and massage conditions. Setting: University laboratory. Patients or Other Participants: Ten healthy subjects (5 men and 5 women) with no history of upper arm injury and no experience in resistance training. Intervention(s): Subjects performed 10 sets of 6 maximal isokinetic (90°·s−1) eccentric actions of the elbow flexors with each arm on a dynamometer, separated by 2 weeks. One arm received 10 minutes of massage 3 hours after eccentric exercise; the contralateral arm received no treatment. Main Outcome Measure(s): Maximal voluntary isometric and isokinetic elbow flexor strength, range of motion, upper arm circumference, plasma creatine kinase activity, and muscle soreness. Results: Delayed-onset muscle soreness was significantly less for the massage condition for peak

  1. Calpains, skeletal muscle function and exercise.

    Science.gov (United States)

    Murphy, Robyn M

    2010-03-01

    1. Skeletal muscle fibres contain ubiquitous (mu-calpain and m-calpain) and muscle-specific (calpain-3) Ca(2+)-dependent proteases. The physiological roles of the calpains are not well understood, although ubiquitous calpains have been associated with apoptosis and myogenesis and calpain-3 is likely involved in sarcomeric remodelling. A defect in the expression of calpain-3 results in limb-girdle muscular dystrophy Type 2A. 2. At resting [Ca(2+)](i), calpains are present predominantly in their full-length, unautolysed/unactivated forms. Once activated, mu-calpain and calpain-3 appear in their autolysed forms and this measurement can be used to determine when in vivo activation occurs. Endogenously expressed mu-calpain and calpain-3 are activated within a physiological [Ca(2+)] range in a Ca(2+)- and time-dependent manner. 3. In skeletal muscle, mu-calpain is a freely diffusible protein that binds rapidly when [Ca(2+)](i) is increased. Calpain-3 is tightly bound in skeletal muscle fibres at the N2A line of the large elastic protein titin. 4. Overall, neither mu-calpain nor calpain-3 are activated immediately following sprint, endurance or eccentric exercise, despite the frequent episodes of high cytoplasmic [Ca(2+)] that would occur during these types of muscle contractions. Importantly, however, a substantial proportion of calpain-3, but not mu-calpain, is activated 24 h after a single bout of eccentric exercise. 5. In vitro studies have shown that calpain-3 becomes activated if exposed for a prolonged period of time (> 1 h) to resting cytoplasmic [Ca(2+)] that are approximately two- to fourfold higher than normal. This suggests that the small but sustained increase in [Ca(2+)](i) that likely occurs after eccentric contractions is both high and long enough to result in calpain-3 activation and supports the role for calpain-3 in sarcomeric remodelling.

  2. Effect of VEGF on the Regenerative Capacity of Muscle Stem Cells in Dystrophic Skeletal Muscle

    Science.gov (United States)

    Deasy, Bridget M; Feduska, Joseph M; Payne, Thomas R; Li, Yong; Ambrosio, Fabrisia; Huard, Johnny

    2009-01-01

    We have isolated a population of muscle-derived stem cells (MDSCs) that, when compared with myoblasts, display an improved regeneration capacity, exhibit better cell survival, and improve myogenesis and angiogenesis. In addition, we and others have observed that the origin of the MDSCs may reside within the blood vessel walls (endothelial cells and pericytes). Here, we investigated the role of vascular endothelial growth factor (VEGF)–mediated angiogenesis in MDSC transplantation–based skeletal muscle regeneration in mdx mice (an animal model of muscular dystrophy). We studied MDSC and MDSC transduced to overexpress VEGF; no differences were observed in vitro in terms of phenotype or myogenic differentiation. However, after in vivo transplantation, we observe an increase in angiogenesis and endogenous muscle regeneration as well as a reduction in muscle fibrosis in muscles transplanted with VEGF-expressing cells when compared to control cells. In contrast, we observe a significant decrease in vascularization and an increase in fibrosis in the muscles transplanted with MDSCs expressing soluble forms-like tyrosine kinase 1 (sFlt1) (VEGF-specific antagonist) when compared to control MDSCs. Our results indicate that VEGF-expressing cells do not increase the number of dystrophin-positive fibers in the injected mdx muscle, when compared to the control MDSCs. Together the results suggest that the transplantation of VEGF-expressing MDSCs improved skeletal muscle repair through modulation of angiogenesis, regeneration and fibrosis in the injected mdx skeletal muscle. PMID:19603004

  3. Hsp72 preserves muscle function and slows progression of severe muscular dystrophy.

    Science.gov (United States)

    Gehrig, Stefan M; van der Poel, Chris; Sayer, Timothy A; Schertzer, Jonathan D; Henstridge, Darren C; Church, Jarrod E; Lamon, Severine; Russell, Aaron P; Davies, Kay E; Febbraio, Mark A; Lynch, Gordon S

    2012-04-04

    Duchenne muscular dystrophy (DMD) is a severe and progressive muscle wasting disorder caused by mutations in the dystrophin gene that result in the absence of the membrane-stabilizing protein dystrophin. Dystrophin-deficient muscle fibres are fragile and susceptible to an influx of Ca(2+), which activates inflammatory and muscle degenerative pathways. At present there is no cure for DMD, and existing therapies are ineffective. Here we show that increasing the expression of intramuscular heat shock protein 72 (Hsp72) preserves muscle strength and ameliorates the dystrophic pathology in two mouse models of muscular dystrophy. Treatment with BGP-15 (a pharmacological inducer of Hsp72 currently in clinical trials for diabetes) improved muscle architecture, strength and contractile function in severely affected diaphragm muscles in mdx dystrophic mice. In dko mice, a phenocopy of DMD that results in severe spinal curvature (kyphosis), muscle weakness and premature death, BGP-15 decreased kyphosis, improved the dystrophic pathophysiology in limb and diaphragm muscles and extended lifespan. We found that the sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA, the main protein responsible for the removal of intracellular Ca(2+)) is dysfunctional in severely affected muscles of mdx and dko mice, and that Hsp72 interacts with SERCA to preserve its function under conditions of stress, ultimately contributing to the decreased muscle degeneration seen with Hsp72 upregulation. Treatment with BGP-15 similarly increased SERCA activity in dystrophic skeletal muscles. Our results provide evidence that increasing the expression of Hsp72 in muscle (through the administration of BGP-15) has significant therapeutic potential for DMD and related conditions, either as a self-contained therapy or as an adjuvant with other potential treatments, including gene, cell and pharmacological therapies.

  4. SKELETAL MUSCLE CAPILLARY FUNCTION: CONTEMPORARY OBSERVATIONS AND NOVEL HYPOTHESES

    Science.gov (United States)

    Poole, David C.; Copp, Steven W.; Ferguson, Scott K.; Musch, Timothy I.

    2014-01-01

    The capillary bed constitutes a vast surface facilitating exchange of O2, substrates and metabolites between blood and organs. In contracting skeletal muscle capillary blood flow and O2 diffusing capacity as well as O2 flux may increase two orders of magnitude above resting. Chronic diseases such as heart failure, diabetes and also sepsis impair these processes leading to compromised energetic, metabolic and ultimately contractile function. Among researchers seeking to understand blood-myocyte exchange in health and the bases for dysfunction in disease there is a fundamental disconnect between microcirculation specialists and many physiologists and physiologist clinicians. Whereas the former observe capillaries and capillary function directly (muscle intravital microscopy) the latter generally use indirect methodologies (e.g., post-mortem tissue analysis, 1-methyl xanthine, contrast enhanced ultrasound, permeability surface area product) and interpret their findings based upon August Krogh’s observations made nearly a century ago. “Kroghian” theory holds that only a small fraction of capillaries support red blood cell (RBC) flux in resting muscle leaving the vast majority to be “recruited” (i.e., initiate RBC flux) during contractions which would constitute the basis for increasing capillary exchange surface area and reducing capillary-mitochondrial diffusion distances. Experimental techniques each have their strengths and weaknesses and often the correct or complete answer to a problem emerges from integration across multiple technologies. Today Krogh’s entrenched “capillary recruitment” hypothesis is challenged by direct observations of capillaries in contracting muscle; something that he and his colleagues could not do. Moreover, in the peer-reviewed scientific literature, application of a range of contemporary physiological technologies including intravital microscopy of contracting muscle, magnetic resonance and near infrared spectroscopy and

  5. Inspiratory Muscle Training and Functional Capacity in Patients Undergoing Cardiac Surgery

    OpenAIRE

    André Luiz Lisboa Cordeiro; Thiago Araújo de Melo; Daniela Neves; Julianne Luna; Mateus Souza Esquivel; André Raimundo França Guimarães; Daniel Lago Borges; Jefferson Petto

    2016-01-01

    Abstract Introduction: Cardiac surgery is a highly complex procedure which generates worsening of lung function and decreased inspiratory muscle strength. The inspiratory muscle training becomes effective for muscle strengthening and can improve functional capacity. Objective: To investigate the effect of inspiratory muscle training on functional capacity submaximal and inspiratory muscle strength in patients undergoing cardiac surgery. Methods: This is a clinical randomized controlled tri...

  6. Transient impairments in single muscle fibre contractile function after prolonged cycling in elite endurance athletes

    DEFF Research Database (Denmark)

    Hvid, L G; Gejl, Kasper Degn; Bech, R D

    2013-01-01

    Prolonged muscle activity impairs whole-muscle performance and function. However, little is known about the effects of prolonged muscle activity on the contractile function of human single muscle fibres. The purpose of this study was to investigate the effects of prolonged exercise and subsequent...... recovery on the contractile function of single muscle fibres obtained from elite athletes....

  7. Myosatellite cells in muscle of growing carp (Cyprinus carpio L.).

    NARCIS (Netherlands)

    Koumans, J.T.M.

    1992-01-01

    Myosatellite cells are small spindle shaped myogenic cells situated between the sarcolemma and the basal lamina that surrounds every muscle fibre. Based on information from mammals and birds, myosatellite cells are considered to play an important role in postlarval muscle growth in fish. Myosatellit

  8. Isolation and Culture of Satellite Cells from Mouse Skeletal Muscle.

    Science.gov (United States)

    Musarò, Antonio; Carosio, Silvia

    2017-01-01

    Skeletal muscle tissue is characterized by a population of quiescent mononucleated myoblasts, localized between the basal lamina and sarcolemma of myofibers, known as satellite cells. Satellite cells play a pivotal role in muscle homeostasis and are the major source of myogenic precursors in mammalian muscle regeneration.This chapter describes protocols for isolation and culturing satellite cells isolated from mouse skeletal muscles. The classical procedure, which will be discussed extensively in this chapter, involves the enzymatic dissociation of skeletal muscles, while the alternative method involves isolation of satellite cells from isolated myofibers in which the satellite cells remain in their in situ position underneath the myofiber basal lamina.In particular, we discuss the technical aspect of satellite cell isolation, the methods necessary to enrich the satellite cell fraction and the culture conditions that optimize proliferation and myotube formation of mouse satellite cells.

  9. Erythropoietin improves functional and histological recovery of traumatized skeletal muscle tissue.

    Science.gov (United States)

    Rotter, Robert; Menshykova, Marija; Winkler, Tobias; Matziolis, Georg; Stratos, Ioannis; Schoen, Matthias; Bittorf, Thomas; Mittlmeier, Thomas; Vollmar, Brigitte

    2008-12-01

    Apart from its hematopoietic effect, erythropoietin (EPO) is known as pleiotropic cytokine with anti-inflammatory and anti-apoptotic properties. Here, we evaluated for the first time the EPO-dependent regeneration capacity in an in vivo rat model of skeletal muscle trauma. A myoblast cell line was used to study the effect of EPO on serum deprivation-induced cell apoptosis in vitro. A crush injury was performed to the left soleus muscle in 80 rats treated with either EPO or saline. Muscle recovery was assessed by analysis of contraction capacities. Intravital microscopy, BrdU/laminin double immunohistochemistry and cleaved caspase-3 immunohistochemistry of muscle tissue on days 1, 7, 14, and 42 posttrauma served for assessment of local microcirculation, tissue integrity, and cell proliferation. Serum deprivation-induced myoblast apoptosis of 23.9 +/- 1.5% was reduced by EPO to 17.2 +/- 0.8%. Contraction force analysis in the EPO-treated animals revealed significantly improved muscle strength with 10-20% higher values of twitch and tetanic forces over the 42-day observation period. EPO-treated muscle tissue displayed improved functional capillary density as well as reduced leukocytic response and consecutively macromolecular leakage over day 14. Concomitantly, muscle histology showed significantly increased numbers of BrdU-positive satellite cells and interstitial cells as well as slightly lower counts of cleaved caspase-3-positive interstitial cells. EPO results in faster and better regeneration of skeletal muscle tissue after severe trauma and goes along with improved microcirculation. Thus, EPO, a compound established as clinically safe, may represent a promising therapeutic option to optimize the posttraumatic course of muscle tissue healing.

  10. Resistance Exercise Reduces Skeletal Muscle Cachexia and Improves Muscle Function in Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Salaheddin Sharif

    2011-01-01

    Full Text Available Rheumatoid arthritis (RA is a chronic, systemic, autoimmune, inflammatory disease associated with cachexia (reduced muscle and increased fat. Although strength-training exercise has been used in persons with RA, it is not clear if it is effective for reducing cachexia. A 46-year-old woman was studied to determine: (i if resistance exercise could reverse cachexia by improving muscle mass, fiber cross-sectional area, and muscle function; and (2 if elevated apoptotic signaling was involved in cachexia with RA and could be reduced by resistance training. A needle biopsy was obtained from the vastus lateralis muscle of the RA subject before and after 16 weeks of resistance training. Knee extensor strength increased by 13.6% and fatigue decreased by 2.8% Muscle mass increased by 2.1%. Average muscle fiber cross-sectional area increased by 49.7%, and muscle nuclei increased slightly after strength training from 0.08 to 0.12 nuclei/μm2. In addition, there was a slight decrease (1.6% in the number of apoptotic muscle nuclei after resistance training. This case study suggests that resistance training may be a good tool for increasing the number of nuclei per fiber area, decreasing apoptotic nuclei, and inducing fiber hypertrophy in persons with RA, thereby slowing or reversing rheumatoid cachexia.

  11. Alfacalcidol improves muscle power, muscle function and balance in elderly patients with reduced bone mass.

    Science.gov (United States)

    Schacht, E; Ringe, Johann D

    2012-01-01

    We investigated the effect of daily therapy with 1 mcg alfacalcidol (Doss(®)-TEVA/AWD-pharma) on muscle power, muscle function, balance performance and fear of falls in an open, multi-centered, uncontrolled, prospective study on a cohort of patients with reduced bone mass. Among the 2,097 participants, 87.1% were post-menopausal women and 12.9% were men. Mean age was 74.8 years and mean body mass index (BMI) 26.3 kg/m². A total of 75.3% of the study population had osteoporosis, 81% a diagnosis of "increased risk of falls" and 70.1% had a creatinine clearance (CrCl) of muscle function and muscle power tests at onset and after 3 and 6 months: the timed up and go test (TUG) and the chair rising test (CRT). At baseline and after 6 months, participants performed the tandem gait test (TGT) and filled out a questionnaire evaluating fear of falling. Successful performance in the muscle tests is associated with a significantly lower risk of falls and non-vertebral fractures in elderly patients (successful test performance: TUG ≤ 10 s (sec), CRT ≤ 10 s, TGT ≥ 8 steps). A significant improvement in the performance of the two muscle tests was proved already after 3 months of treatment with alfacalcidol and further increased by the end of the therapeutic intervention. There were significant increases in the number of participants able to successfully perform the tests: 24.6% at baseline and 46.3% at the end of trial for the TUG (P muscle power, muscle function and balance and reduces fear of falls. The significant improvement in the three muscle and balance tests and fear of falls may have a preventative effect on falls and fractures. We suggest that the quantitative risk tests used in this study could be reliable surrogate parameters for the risk of falls and fractures in elderly patients.

  12. 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.

  13. Potential gene regulatory role for cyclin D3 in muscle cells

    Indian Academy of Sciences (India)

    Fathima Athar; Veena K Parnaik

    2015-09-01

    Cyclin D3 is important for muscle development and regeneration, and is involved in post-mitotic arrest of muscle cells. Cyclin D3 also has cell-cycle-independent functions such as regulation of specific genes in other tissues. Ectopic expression of cyclin D3 in myoblasts, where it is normally undetectable, promotes muscle gene expression and faster differentiation kinetics upon serum depletion. In the present study, we investigated the mechanistic role of cyclin D3 in muscle gene regulation. We initially showed by mutational analysis that a stable and functional cyclin D3 was required for promoting muscle differentiation. Using chromatin immunoprecipitation assays, we demonstrated that expression of cyclin D3 in undifferentiated myoblasts altered histone epigenetic marks at promoters of muscle-specific genes like MyoD, Pax7, myogenin and muscle creatine kinase but not non-muscle genes. Cyclin D3 expression also reduced the mRNA levels of certain epigenetic modifier genes. Our data suggest that epigenetic modulation of muscle-specific genes in cyclin-D3-expressing myoblasts may be responsible for faster differentiation kinetics upon serum depletion. Our results have implications for a regulatory role for cyclin D3 in muscle-specific gene activation.

  14. Muscle function in avian flight: achieving power and control

    Science.gov (United States)

    Biewener, Andrew A.

    2011-01-01

    Flapping flight places strenuous requirements on the physiological performance of an animal. Bird flight muscles, particularly at smaller body sizes, generally contract at high frequencies and do substantial work in order to produce the aerodynamic power needed to support the animal's weight in the air and to overcome drag. This is in contrast to terrestrial locomotion, which offers mechanisms for minimizing energy losses associated with body movement combined with elastic energy savings to reduce the skeletal muscles' work requirements. Muscles also produce substantial power during swimming, but this is mainly to overcome body drag rather than to support the animal's weight. Here, I review the function and architecture of key flight muscles related to how these muscles contribute to producing the power required for flapping flight, how the muscles are recruited to control wing motion and how they are used in manoeuvring. An emergent property of the primary flight muscles, consistent with their need to produce considerable work by moving the wings through large excursions during each wing stroke, is that the pectoralis and supracoracoideus muscles shorten over a large fraction of their resting fibre length (33–42%). Both muscles are activated while being lengthened or undergoing nearly isometric force development, enhancing the work they perform during subsequent shortening. Two smaller muscles, the triceps and biceps, operate over a smaller range of contractile strains (12–23%), reflecting their role in controlling wing shape through elbow flexion and extension. Remarkably, pigeons adjust their wing stroke plane mainly via changes in whole-body pitch during take-off and landing, relative to level flight, allowing their wing muscles to operate with little change in activation timing, strain magnitude and pattern. PMID:21502121

  15. The myonuclear domain is not maintained in skeletal muscle during either atrophy or programmed cell death.

    Science.gov (United States)

    Schwartz, Lawrence M; Brown, Christine; McLaughlin, Kevin; Smith, Wendy; Bigelow, Carol

    2016-10-01

    Skeletal muscle mass can increase during hypertrophy or decline dramatically in response to normal or pathological signals that trigger atrophy. Many reports have documented that the number of nuclei within these cells is also plastic. It has been proposed that a yet-to-be-defined regulatory mechanism functions to maintain a relatively stable relationship between the cytoplasmic volume and nuclear number within the cell, a phenomenon known as the "myonuclear domain" hypothesis. While it is accepted that hypertrophy is typically associated with the addition of new nuclei to the muscle fiber from stem cells such as satellite cells, the loss of myonuclei during atrophy has been controversial. The intersegmental muscles from the tobacco hawkmoth Manduca sexta are composed of giant syncytial cells that undergo sequential developmental programs of atrophy and programmed cell death at the end of metamorphosis. Since the intersegmental muscles lack satellite cells or regenerative capacity, the tissue is not "contaminated" by these nonmuscle nuclei. Consequently, we monitored muscle mass, cross-sectional area, nuclear number, and cellular DNA content during atrophy and the early phases of cell death. Despite a ∼75-80% decline in muscle mass and cross-sectional area during the period under investigation, there were no reductions in nuclear number or DNA content, and the myonuclear domain was reduced by ∼85%. These data suggest that the myonuclear domain is not an intrinsic property of skeletal muscle and that nuclei persist through atrophy and programmed cell death. Copyright © 2016 the American Physiological Society.

  16. Is functional hypertrophy and specific force coupled with the addition of myonuclei at the single muscle fiber level?

    Science.gov (United States)

    Qaisar, Rizwan; Renaud, Guillaume; Morine, Kevin; Barton, Elisabeth R; Sweeney, H Lee; Larsson, Lars

    2012-03-01

    Muscle force is typically proportional to muscle size, resulting in constant force normalized to muscle fiber cross-sectional area (specific force). Mice overexpressing insulin-like growth factor-1 (IGF-1) exhibit a proportional gain in muscle force and size, but not the myostatin-deficient mice. In an attempt to explore the role of the cytoplasmic volume supported by individual myonuclei [myonuclear domain (MND) size] on functional capacity of skeletal muscle, we have investigated specific force in relation to MND and the content of the molecular motor protein, myosin, at the single muscle fiber level from myostatin-knockout (Mstn(-/-)) and IGF-1-overexpressing (mIgf1(+/+)) mice. We hypothesize that the addition of extra myonuclei is a prerequisite for maintenance of specific force during muscle hypertrophy. A novel algorithm was used to measure individual MNDs in 3 dimensions along the length of single muscle fibers from the fast-twitch extensor digitorum longus and the slow-twitch soleus muscle. A significant effect of the size of individual MNDs in hypertrophic muscle fibers on both specific force and myosin content was observed. This effect was muscle cell type specific and suggested there is a critical volume individual myonuclei can support efficiently. The large MNDs found in fast muscles of Mstn(-/-) mice were correlated with the decrement in specific force and myosin content in Mstn(-/-) muscles. Thus, myostatin inhibition may not be able to maintain the appropriate MND for optimal function.

  17. PAT1 (SLC36A1) shows nuclear localization and affect growth of smooth muscle cells from rats

    DEFF Research Database (Denmark)

    Jensen, Anne; Figueiredo-Larsen, Evan Manuel; Holm, René

    2014-01-01

    the localization and function of PAT1 in smooth muscle cells (SMCs). The PAT1 protein was found in smooth muscles from rat intestine and in the embryonic rat aorta cell line A7r5. Immunolocalization and cellular fractionation studies revealed that the majority of the PAT1 protein located within the cell nucleus...

  18. Impaired PGC-1alpha function in muscle in Huntington's disease.

    Science.gov (United States)

    Chaturvedi, Rajnish K; Adhihetty, Peter; Shukla, Shubha; Hennessy, Thomas; Calingasan, Noel; Yang, Lichuan; Starkov, Anatoly; Kiaei, Mahmoud; Cannella, Milena; Sassone, Jenny; Ciammola, Andrea; Squitieri, Fernando; Beal, M Flint

    2009-08-15

    We investigated the role of PPAR gamma coactivator 1alpha (PGC-1alpha) in muscle dysfunction in Huntington's disease (HD). We observed reduced PGC-1alpha and target genes expression in muscle of HD transgenic mice. We produced chronic energy deprivation in HD mice by administering the catabolic stressor beta-guanidinopropionic acid (GPA), a creatine analogue that reduces ATP levels, activates AMP-activated protein kinase (AMPK), which in turn activates PGC-1alpha. Treatment with GPA resulted in increased expression of AMPK, PGC-1alpha target genes, genes for oxidative phosphorylation, electron transport chain and mitochondrial biogenesis, increased oxidative muscle fibers, numbers of mitochondria and motor performance in wild-type, but not in HD mice. In muscle biopsies from HD patients, there was decreased PGC-1alpha, PGC-1beta and oxidative fibers. Oxygen consumption, PGC-1alpha, NRF1 and response to GPA were significantly reduced in myoblasts from HD patients. Knockdown of mutant huntingtin resulted in increased PGC-1alpha expression in HD myoblast. Lastly, adenoviral-mediated delivery of PGC-1alpha resulted increased expression of PGC-1alpha and markers for oxidative muscle fibers and reversal of blunted response for GPA in HD mice. These findings show that impaired function of PGC-1alpha plays a critical role in muscle dysfunction in HD, and that treatment with agents to enhance PGC-1alpha function could exert therapeutic benefits. Furthermore, muscle may provide a readily accessible tissue in which to monitor therapeutic interventions.

  19. Capsular attachment of the brachialis muscle (Portal's muscle): an anatomical and functional study.

    Science.gov (United States)

    Tubbs, R Shane; Yablick, Michael W; Loukas, Marios; Shoja, Mohammadali M; Ardalan, Mohammad; Oakes, W Jerry

    2008-05-01

    There is a paucity of information regarding the detailed anatomy of the capsular part of the brachialis muscle in the extant literature. Our current study seeks to further elucidate the presence, morphology, and potential function of this muscle. Thirty-six cadaveric upper extremities underwent dissection of their anterior elbow joint capsule with special attention to any fibers attaching onto it from the brachialis muscle. We found that the majority of fibers of the brachialis simply passed superficial to the anterior elbow joint capsule. The highest concentration of fibers was noted to be onto the anteromedial joint capsule via connective tissue and not direct muscle attachment. No specimen was found to have a distinct muscle belly associated with these connections to the joint capsule. On all sides, such fibers were simply deeper attachments of the brachialis muscle. Following tension on these deeper fibers, retraction of the joint capsule was not noted. We would speculate, based on our study, that these fibers of the brachialis do not represent a separate muscle per se and do not retract the anterior elbow joint capsule with flexion of the forearm as has been theorized. These data may be of use to surgeons who operate this region so that attention to preservation of such fibers may be of less importance.

  20. Action of obestatin in skeletal muscle repair: stem cell expansion, muscle growth, and microenvironment remodeling.

    Science.gov (United States)

    Gurriarán-Rodríguez, Uxía; Santos-Zas, Icía; González-Sánchez, Jessica; Beiroa, Daniel; Moresi, Viviana; Mosteiro, Carlos S; Lin, Wei; Viñuela, Juan E; Señarís, José; García-Caballero, Tomás; Casanueva, Felipe F; Nogueiras, Rubén; Gallego, Rosalía; Renaud, Jean-Marc; Adamo, Sergio; Pazos, Yolanda; Camiña, Jesús P

    2015-06-01

    The development of therapeutic strategies for skeletal muscle diseases, such as physical injuries and myopathies, depends on the knowledge of regulatory signals that control the myogenic process. The obestatin/GPR39 system operates as an autocrine signal in the regulation of skeletal myogenesis. Using a mouse model of skeletal muscle regeneration after injury and several cellular strategies, we explored the potential use of obestatin as a therapeutic agent for the treatment of trauma-induced muscle injuries. Our results evidenced that the overexpression of the preproghrelin, and thus obestatin, and GPR39 in skeletal muscle increased regeneration after muscle injury. More importantly, the intramuscular injection of obestatin significantly enhanced muscle regeneration by simulating satellite stem cell expansion as well as myofiber hypertrophy through a kinase hierarchy. Added to the myogenic action, the obestatin administration resulted in an increased expression of vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor 2 (VEGFR2) and the consequent microvascularization, with no effect on collagen deposition in skeletal muscle. Furthermore, the potential inhibition of myostatin during obestatin treatment might contribute to its myogenic action improving muscle growth and regeneration. Overall, our data demonstrate successful improvement of muscle regeneration, indicating obestatin is a potential therapeutic agent for skeletal muscle injury and would benefit other myopathies related to muscle regeneration.

  1. Biomechanical considerations in the modeling of muscle function.

    Science.gov (United States)

    Andrews, J G; Hay, J G

    1983-09-01

    The instantaneous functional role of a voluntary muscle in the neighborhood of a joint is often described in clinical terms (e.g. flexor; abductor; external rotator; agonist; contracting concentrically and isokinetically) that seen sufficiently explicit and clear in certain simple situations, but have not yet been carefully defined in precise biomechanical terminology for the general case. In order to describe the functional role of a voluntary muscle as its acts to change and/or maintain the configuration of a joint, it is necessary to make certain modeling assumptions. These include modeling the joint, modeling the muscle force line of action in the joint neighborhood, and establishing the location and orientation of the three joint axes for all possible joint configurations. Modeling the joint as a point leads to simple and sensible definitions which are consistent with clinical practice. The straight line model is most conveniently used to establish the muscle force line of action. A RHO coordinate system embedded in the distal joint segment with origin at the joint center point, and with intersecting axes coincident with the F/E, A/A and I/XR axes when the joint is in the anatomical position, is the joint coordinate system of choice to describe the turning effects of the muscle about the joint. Sensible and simple biomechanical definitions for clinical terms describing muscular contractions (i.e. concentric; eccentric; isometric; isokinetic; isotonic) were presented and appear to be relatively uncontroversial. Alternative biomechanical definitions for agonistic and antagonistic muscular activity were also presented, as were arguments for choosing a simple definition based on using the joint resultant moment as the criterion measure relative to which the individual muscle's moment about J should be compared. Biomechanical definitions for determining when a muscle functions as a joint flexor or extensor, abductor or adductor, and internal or external rotator

  2. Identification and Characterization of the Dermal Panniculus Carnosus Muscle Stem Cells

    Directory of Open Access Journals (Sweden)

    Neia Naldaiz-Gastesi

    2016-09-01

    Full Text Available The dermal Panniculus carnosus (PC muscle is important for wound contraction in lower mammals and represents an interesting model of muscle regeneration due to its high cell turnover. The resident satellite cells (the bona fide muscle stem cells remain poorly characterized. Here we analyzed PC satellite cells with regard to developmental origin and purported function. Lineage tracing shows that they originate in Myf5+, Pax3/Pax7+ cell populations. Skin and muscle wounding increased PC myofiber turnover, with the satellite cell progeny being involved in muscle regeneration but with no detectable contribution to the wound-bed myofibroblasts. Since hematopoietic stem cells fuse to PC myofibers in the absence of injury, we also studied the contribution of bone marrow-derived cells to the PC satellite cell compartment, demonstrating that cells of donor origin are capable of repopulating the PC muscle stem cell niche after irradiation and bone marrow transplantation but may not fully acquire the relevant myogenic commitment.

  3. Treating asthma means treating airway smooth muscle cells

    NARCIS (Netherlands)

    Zuyderduyn, S; Sukkar, M B; Fust, A; Dhaliwal, S; Burgess, J K

    2008-01-01

    Asthma is characterised by airway hyperresponsiveness, airway inflammation and airway remodelling. Airway smooth muscle cells are known to be the main effector cells of airway narrowing. In the present paper, studies will be discussed that have led to a novel view of the role of airway smooth muscle

  4. Ageing induced vascular smooth muscle cell senescence in atherosclerosis.

    Science.gov (United States)

    Uryga, Anna K; Bennett, Martin R

    2016-04-15

    Atherosclerosis is a disease of ageing in that its incidence and prevalence increase with age. However, atherosclerosis is also associated with biological ageing, manifest by a number of typical hallmarks of ageing in the atherosclerotic plaque. Thus, accelerated biological ageing may be superimposed on the effects of chronological ageing in atherosclerosis. Tissue ageing is seen in all cells that comprise the plaque, but particularly in vascular smooth muscle cells (VSMCs). Hallmarks of ageing include evidence of cell senescence, DNA damage (including telomere attrition), mitochondrial dysfunction, a pro-inflammatory secretory phenotype, defects in proteostasis, epigenetic changes, deregulated nutrient sensing, and exhaustion of progenitor cells. In this model, initial damage to DNA (genomic, telomeric, mitochondrial and epigenetic changes) results in a number of cellular responses (cellular senescence, deregulated nutrient sensing and defects in proteostasis). Ultimately, ongoing damage and attempts at repair by continued proliferation overwhelm reparative capacity, causing loss of specialised cell functions, cell death and inflammation. This review summarises the evidence for accelerated biological ageing in atherosclerosis, the functional consequences of cell ageing on cells comprising the plaque, and the causal role that VSMC senescence plays in atherogenesis. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  5. Vascular smooth muscle progenitor cells: building and repairing blood vessels.

    Science.gov (United States)

    Majesky, Mark W; Dong, Xiu Rong; Regan, Jenna N; Hoglund, Virginia J

    2011-02-04

    Molecular pathways that control the specification, migration, and number of available smooth muscle progenitor cells play key roles in determining blood vessel size and structure, capacity for tissue repair, and progression of age-related disorders. Defects in these pathways produce malformations of developing blood vessels, depletion of smooth muscle progenitor cell pools for vessel wall maintenance and repair, and aberrant activation of alternative differentiation pathways in vascular disease. A better understanding of the molecular mechanisms that uniquely specify and maintain vascular smooth muscle cell precursors is essential if we are to use advances in stem and progenitor cell biology and somatic cell reprogramming for applications directed to the vessel wall.

  6. Intercellular adhesion molecule-1 expression by skeletal muscle cells augments myogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Qingnian; Dearth, Christopher L.; Corbett, Jacob T. [Department of Kinesiology, The University of Toledo, Toledo, OH (United States); Pierre, Philippe [Centre d’Immunologie de Marseille-Luminy U2M, Aix-Marseille Université, Marseille (France); INSERM U631, Institut National de la Santé et Recherche Médicale, Marseille (France); CNRS UMR6102, Centre National de la Recherche Scientifique, Marseille (France); Chadee, Deborah N. [Department of Biological Sciences, The University of Toledo, Toledo, OH (United States); Pizza, Francis X., E-mail: Francis.Pizza@utoledo.edu [Department of Kinesiology, The University of Toledo, Toledo, OH (United States)

    2015-02-15

    We previously demonstrated that the expression of intercellular adhesion molecule-1 (ICAM-1) by skeletal muscle cells after muscle overload contributes to ensuing regenerative and hypertrophic processes in skeletal muscle. The objective of the present study is to reveal mechanisms through which skeletal muscle cell expression of ICAM-1 augments regenerative and hypertrophic processes of myogenesis. This was accomplished by genetically engineering C2C12 myoblasts to stably express ICAM-1, and by inhibiting the adhesive and signaling functions of ICAM-1 through the use of a neutralizing antibody or cell penetrating peptide, respectively. Expression of ICAM-1 by cultured skeletal muscle cells augmented myoblast–myoblast adhesion, myotube formation, myonuclear number, myotube alignment, myotube–myotube fusion, and myotube size without influencing the ability of myoblasts to proliferate or differentiate. ICAM-1 augmented myotube formation, myonuclear accretion, and myotube alignment through a mechanism involving adhesion-induced activation of ICAM-1 signaling, as these dependent measures were reduced via antibody and peptide inhibition of ICAM-1. The adhesive and signaling functions of ICAM-1 also facilitated myotube hypertrophy through a mechanism involving myotube–myotube fusion, protein synthesis, and Akt/p70s6k signaling. Our findings demonstrate that ICAM-1 expression by skeletal muscle cells augments myogenesis, and establish a novel mechanism through which the inflammatory response facilitates growth processes in skeletal muscle. - Highlights: • We examined mechanisms through which skeletal muscle cell expression of ICAM-1 facilitates events of in vitro myogenesis. • Expression of ICAM-1 by cultured myoblasts did not influence their ability to proliferate or differentiate. • Skeletal muscle cell expression of ICAM-1 augmented myoblast fusion, myotube alignment, myotube–myotube fusion, and myotube size. • ICAM-1 augmented myogenic processes through

  7. Vitamin D and muscle function in older people

    NARCIS (Netherlands)

    Janssen, H.C.J.P.

    2014-01-01

    Vitamin D deficiency is a worldwide problem particularly among older people, who are more susceptible due to diminished vitamin D synthesis in the skin and low dietary intake of vitamin D. Vitamin D has been associated with various (patho)physiological functions including muscle function. It is impo

  8. Vitamin D and muscle function in older people

    NARCIS (Netherlands)

    Janssen, H.C.J.P.

    2014-01-01

    Vitamin D deficiency is a worldwide problem particularly among older people, who are more susceptible due to diminished vitamin D synthesis in the skin and low dietary intake of vitamin D. Vitamin D has been associated with various (patho)physiological functions including muscle function. It is impo

  9. Functional and architectural complexity within and between muscles: regional variation and intermuscular force transmission

    OpenAIRE

    Higham, Timothy E.; Biewener, Andrew A.

    2011-01-01

    Over the past 30 years, studies of single muscles have revealed complex patterns of regional variation in muscle architecture, activation, strain and force. In addition, muscles are often functionally integrated with other muscles in parallel or in series. Understanding the extent of this complexity and the interactions between muscles will profoundly influence how we think of muscles in relation to organismal function, and will allow us to address questions regarding the functional benefits ...

  10. 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

    2014-04-01

    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.

  11. Smooth Muscle Progenitor Cells Derived From Human Pluripotent Stem Cells Induce Histologic Changes in Injured Urethral Sphincter.

    Science.gov (United States)

    Li, Yanhui; Wen, Yan; Wang, Zhe; Wei, Yi; Wani, Prachi; Green, Morgaine; Swaminathan, Ganesh; Ramamurthi, Anand; Pera, Renee Reijo; Chen, Bertha

    2016-12-01

    : Data suggest that myoblasts from various sources, including bone marrow, skeletal muscle, and adipose tissue, can restore muscle function in patients with urinary incontinence. Animal data have indicated that these progenitor cells exert mostly a paracrine effect on the native tissues rather than cell regeneration. Limited knowledge is available on the in vivo effect of human stem cells or muscle progenitors on injured muscles. We examined in vivo integration of smooth muscle progenitor cells (pSMCs) derived from human pluripotent stem cells (hPSCs). pSMCs were derived from a human embryonic stem cell line (H9-ESCs) and two induced pluripotent stem cell (iPSC) lines. pSMCs were injected periurethrally into urethral injury rat models (2 × 10(6) cells per rat) or intramuscularly into severe combined immunodeficiency mice. Histologic and quantitative image analysis revealed that the urethras in pSMC-treated rats contained abundant elastic fibers and thicker muscle layers compared with the control rats. Western blot confirmed increased elastin/collagen III content in the urethra and bladder of the H9-pSMC-treated rats compared with controls. iPSC-pSMC treatment also showed similar trends in elastin and collagen III. Human elastin gene expression was not detectable in rodent tissues, suggesting that the extracellular matrix synthesis resulted from the native rodent tissues rather than from the implanted human cells. Immunofluorescence staining and in vivo bioluminescence imaging confirmed long-term engraftment of pSMCs into the host urethra and the persistence of the smooth muscle phenotype. Taken together, the data suggest that hPSC-derived pSMCs facilitate restoration of urethral sphincter function by direct smooth muscle cell regeneration and by inducing native tissue elastin/collagen III remodeling. The present study provides evidence that a pure population of human smooth muscle progenitor cells (pSMCs) derived from human pluripotent stem cells (hPSCs) (human

  12. No beneficial effects of vitamin D supplementation on muscle function or quality of life in primary hyperparathyroidism

    DEFF Research Database (Denmark)

    Rolighed, Lars; Rejnmark, Lars; Sikjaer, Tanja

    2014-01-01

    Context: Impairments of muscle function and strength in patients with primary hyperparathyroidism (PHPT) are rarely addressed although decreased muscle function may contribute to increased fracture risk. Objective: We aimed to assess changes in muscle strength, muscle function, postural stability...

  13. Mycobacterium ulcerans infections cause progressive muscle atrophy and dysfunction, and mycolactone impairs satellite cell proliferation.

    Science.gov (United States)

    Houngbédji, Germain Mabèrou; Bouchard, Patrice; Frenette, Jérôme

    2011-03-01

    Clinical observations from Buruli ulcer (BU) patients in West Africa suggest that severe Mycobacterium ulcerans infections can cause skeletal muscle contracture and atrophy leading to significant impairment in function. In the present study, male mice C57BL/6 were subcutaneously injected with M. ulcerans in proximity to the right biceps muscle, avoiding direct physical contact between the infectious agent and the skeletal muscle. The histological, morphological, and functional properties of the muscles were assessed at different times after the injection. On day 42 postinjection, the isometric tetanic force and the cross-sectional area of the myofibers were reduced by 31% and 29%, respectively, in the proximate-infected muscles relative to the control muscles. The necrotic areas of the proximate-infected muscles had spread to 7% of the total area by day 42 postinjection. However, the number of central nucleated fibers and myogenic regulatory factors (MyoD and myogenin) remained stable and low. Furthermore, Pax-7 expression did not increase significantly in mycolactone-injected muscles, indicating that the satellite cell proliferation is abrogated by the toxin. In addition, the fibrotic area increased progressively during the infection. Lastly, muscle-specific RING finger protein 1 (MuRF-1) and atrogin-1/muscle atrophy F-box protein (atrogin-1/MAFbx), two muscle-specific E3 ubiquitin ligases, were upregulated in the presence of M. ulcerans. These findings confirmed that skeletal muscle is affected in our model of subcutaneous infection with M. ulcerans and that a better understanding of muscle contractures and weakness is essential to develop a therapy to minimize loss of function and promote the autonomy of BU patients.

  14. Mammalian Skeletal Muscle Fibres Promote Non-Muscle Stem Cells and Non-Stem Cells to Adopt Myogenic Characteristics

    Directory of Open Access Journals (Sweden)

    Taryn Morash

    2017-01-01

    Full Text Available Skeletal muscle fibres are unique cells in large animals, often composed of thousands of post-mitotic nuclei. Following skeletal muscle damage, resident stem cells, called satellite cells, commit to myogenic differentiation and migrate to carry out repair. Satellite stem cells migrate on muscle fibres through amoeboid movement, which relies on dynamic cell membrane extension and retraction (blebbing. It is not known whether blebbing is due to the intrinsic properties of satellite cells, or induced by features of the myofibre surface. Here, we determined the influence of the muscle fibre matrix on two important features of muscle regeneration: the ability to migrate and to differentiate down a myogenic lineage. We show that the muscle fibre is able to induce amoeboid movement in non-muscle stem cells and non-stem cells. Secondly, we show that prolonged co-culture on myofibres caused amniotic fluid stem cells and breast cancer cells to express MyoD, a key myogenic determinant. Finally, we show that amniotic fluid stem cells co-cultured on myofibres are able to fuse and make myotubes that express Myosin Heavy Chain.

  15. The accommodative ciliary muscle function is preserved in older humans

    Science.gov (United States)

    Tabernero, Juan; Chirre, Emmanuel; Hervella, Lucia; Prieto, Pedro; Artal, Pablo

    2016-05-01

    Presbyopia, the loss of the eye’s accommodation capability, affects all humans aged above 45–50 years old. The two main reasons for this to happen are a hardening of the crystalline lens and a reduction of the ciliary muscle functionality with age. While there seems to be at least some partial accommodating functionality of the ciliary muscle at early presbyopic ages, it is not yet clear whether the muscle is still active at more advanced ages. Previous techniques used to visualize the accommodation mechanism of the ciliary muscle are complicated to apply in the older subjects, as they typically require fixation stability during long measurement times and/or to have an ultrasound probe directly in contact with the eye. Instead, we used our own developed method based on high-speed recording of lens wobbling to study the ciliary muscle activity in a small group of pseudophakic subjects (around 80 years old). There was a significant activity of the muscle, clearly able to contract under binocular stimulation of accommodation. This supports a purely lenticular-based theory of presbyopia and it might stimulate the search for new solutions to presbyopia by making use of the remaining contraction force still presented in the aging eye.

  16. Anatomical and functional segments of the deltoid muscle.

    Science.gov (United States)

    Sakoma, Yoshimasa; Sano, Hirotaka; Shinozaki, Nobuhisa; Itoigawa, Yoshiaki; Yamamoto, Nobuyuki; Ozaki, Toshifumi; Itoi, Eiji

    2011-02-01

    Previous studies showed that the insertion of the intramuscular tendons of the deltoid muscle formed three discrete lines. The purpose of the present study was to establish a new dividing method of the deltoid muscle into various anatomical segments based on the distribution of the intramuscular tendons with their insertions (anatomical study). We further hoped to clarify the relationship between the anatomical segments and their activity pattern assessed by positron emission tomography with [¹⁸F]-2-fluoro-deoxyglucose (FDG-PET; PET study). Sixty cadaveric shoulders were investigated in the anatomical study. Three tendinous insertions of the deltoid muscle to the humerus were identified. Then, the intramuscular tendons were traced from their humeral insertions to the proximal muscular origins. The extent of each anatomical segment of the muscle including its origin and insertion was determined through careful dissection. Six healthy volunteers were examined using FDG-PET for the PET study. PET images were obtained after exercise of elevation in the scapular plane. On the PET images, margins of each anatomical segment of the deltoid muscle were determined using magnetic resonance images. Then, the standardized uptake value in each segment was calculated to quantify its activity. The anatomical study demonstrated that the deltoid muscle was divided into seven segments based on the distribution of its intramuscular tendons. The PET study revealed that the intake of FDG was not uniform in the deltoid muscle. The area with high FDG intake corresponded well to the individual muscular segments separated by the intramuscular tendons. We conclude that the deltoid muscle has seven anatomical segments, which seem to represent the functional units of this muscle.

  17. Myogenic skeletal muscle satellite cells communicate by tunnelling nanotubes.

    Science.gov (United States)

    Tavi, Pasi; Korhonen, Topi; Hänninen, Sandra L; Bruton, Joseph D; Lööf, Sara; Simon, Andras; Westerblad, Håkan

    2010-05-01

    Quiescent satellite cells sit on the surface of the muscle fibres under the basal lamina and are activated by a variety of stimuli to disengage, divide and differentiate into myoblasts that can regenerate or repair muscle fibres. Satellite cells adopt their parent's fibre type and must have some means of communication with the parent fibre. The mechanisms behind this communication are not known. We show here that satellite cells form dynamic connections with muscle fibres and other satellite cells by F-actin based tunnelling nanotubes (TNTs). Our results show that TNTs readily develop between satellite cells and muscle fibres. Once developed, TNTs permit transport of intracellular material, and even cellular organelles such as mitochondria between the muscle fibre and satellite cells. The onset of satellite cell differentiation markers Pax-7 and MyoD expression was slower in satellite cells cultured in the absence than in the presence of muscle cells. Furthermore physical contact between myofibre and satellite cell progeny is required to maintain subtype identity. Our data establish that TNTs constitute an integral part of myogenic cell communication and that physical cellular interaction control myogenic cell fate determination.

  18. Muscle functional MRI analysis of trunk muscle recruitment during extension exercises in asymptomatic individuals.

    Science.gov (United States)

    De Ridder, E M D; Van Oosterwijck, J O; Vleeming, A; Vanderstraeten, G G; Danneels, L A

    2015-04-01

    The present study examined the activity levels of the thoracic and lumbar extensor muscles during different extension exercise modalities in healthy individuals. Therefore, 14 subjects performed four different types of extension exercises in prone position: dynamic trunk extension, dynamic-static trunk extension, dynamic leg extension, and dynamic-static leg extension. Pre- and post-exercise muscle functional magnetic resonance imaging scans from the latissimus dorsi, the thoracic and lumbar parts of the longissimus, iliocostalis, and multifidus were performed. Differences in water relaxation values (T2-relaxation) before and after exercise were calculated (T2-shift) as a measure of muscle activity and compared between extension modalities. Linear mixed-model analysis revealed higher lumbar extensor activity during trunk extension compared with leg extension (T2-shift of 5.01 ms and 3.55 ms, respectively) and during the dynamic-static exercise performance compared with the dynamic exercise performance (T2-shift of 4.77 ms and 3.55 ms, respectively). No significant differences in the thoracic extensor activity between the exercises could be demonstrated. During all extension exercises, the latissimus dorsi was the least activated compared with the paraspinal muscles. While all extension exercises are equivalent effective to train the thoracic muscles, trunk extension exercises performed in a dynamic-static way are the most appropriate to enhance lumbar muscle strength.

  19. Myogenic differentiation of mesenchymal stem cells for muscle regeneration in urinary tract

    Institute of Scientific and Technical Information of China (English)

    YANG Bin; ZHENG Jun-hua; ZHANG Yuan-yuan

    2013-01-01

    Objective This article was to review the current status of adult mesenchymal stem cells transplantation for muscle regeneration in urinary tract and propose the future prospect in this field.Data sources The data used in this review were mainly obtained from articles listed in Medline and PubMed (2000-2013).The search terms were "mesenchymal stem cells","bladder","stress urinary incontinence" and "tissue engineering".Study selection Articles regarding the adult mesenchymal stem cells for tissue engineering of bladder and stress urinary incontinence were selected and reviewed.Results Adult mesenchymal stem cells had been identified and well characterized in human bone marrow,adipose tissue,skeletal muscle and urine,and demonstrated the capability of differentiating into smooth muscle cells and skeletal muscle cells under myogenic differentiation conditions in vitro.Multiple preclinical and clinical studies indicated that adult mesenchymal stem cells could restore and maintain the structure and function of urinary muscle tissues after transplanted,and potentially improve the quality of life in patients.Conclusions Smooth or skeletal myogenic differentiation of mesenchymal stem cells with regenerative medicine technology may provide a novel approach for muscle regeneration and tissue repair in urinary tract.The long-term effect and safety of mesenchymal stem cell transplantation should be further evaluated before this approach becomes widely used in patients.

  20. Aquaporins in skeletal muscle: reassessment of the functional role of aquaporin-4.

    Science.gov (United States)

    Frigeri, Antonio; Nicchia, Grazia Paola; Balena, Rosalba; Nico, Beatrice; Svelto, Maria

    2004-05-01

    Aquaporin-4 (AQP4) is the major water channel of the neuromuscular system, but its physiological function in both perivascular astrocytes and skeletal muscle sarcolemma is unclear. The purpose of this study was to assess the following in skeletal muscle: a) the expression of all cloned water cannels; b) the functional role of AQP4 using sarcolemma vesicles purified by means of several fractionation methods, and c) the functional effect of AQP4 reduction in mdx mice, the animal model of Duchenne muscular dystrophy (DMD). Immunofluorescence and immunoblot experiments performed with affinity purified antibodies revealed that only AQP1 and AQP4 are expressed in mouse skeletal muscle: AQP1 in endothelial cells of continuous capillaries and AQP4 on the plasma membrane of muscle fiber. Plasma membrane vesicle purification was performed with a procedure extensively used to purify and characterize dystrophin-associated proteins (DAPs) from rabbit skeletal muscle. Western blot analysis showed strong co-enrichment of the analyzed DAPs and AQP4, indicating that the membrane vesicle preparation was highly enriched in sarcolemma. Stopped-flow light-scattering measurements showed high osmotic water permeability of sarcolemma vesicles (approximately 150 microm/s) compatible with the AQP-mediated pathway for water movement. Sarcolemma vesicles prepared from mdx mice revealed, in parallel with AQP4 disappearance from the plasma membrane, a strong reduction in water permeability compared with wild-type mice. Altogether, these results demonstrate high AQP4-mediated water permeability of the skeletal muscle sarcolemma. Expression of sarcolemmal AQP4 together with that of vascular AQP1 may be responsible for the fast water transfer from the blood into the muscle during intense activity. These data imply an important role for aquaporins in skeletal muscle physiology as well as an involvement of AQP4 in the molecular alterations that occur in the muscle of DMD patients.

  1. Asymmetric division of clonal muscle stem cells coordinates muscle regeneration in vivo.

    Science.gov (United States)

    Gurevich, David B; Nguyen, Phong Dang; Siegel, Ashley L; Ehrlich, Ophelia V; Sonntag, Carmen; Phan, Jennifer M N; Berger, Silke; Ratnayake, Dhanushika; Hersey, Lucy; Berger, Joachim; Verkade, Heather; Hall, Thomas E; Currie, Peter D

    2016-07-01

    Skeletal muscle is an example of a tissue that deploys a self-renewing stem cell, the satellite cell, to effect regeneration. Recent in vitro studies have highlighted a role for asymmetric divisions in renewing rare "immortal" stem cells and generating a clonal population of differentiation-competent myoblasts. However, this model currently lacks in vivo validation. We define a zebrafish muscle stem cell population analogous to the mammalian satellite cell and image the entire process of muscle regeneration from injury to fiber replacement in vivo. This analysis reveals complex interactions between satellite cells and both injured and uninjured fibers and provides in vivo evidence for the asymmetric division of satellite cells driving both self-renewal and regeneration via a clonally restricted progenitor pool.

  2. Comparative analysis of mesenchymal stem cells from adult mouse adipose, muscle, and fetal muscle.

    Science.gov (United States)

    Lei, Hulong; Yu, Bing; Huang, Zhiqing; Yang, Xuerong; Liu, Zehui; Mao, Xiangbing; Tian, Gang; He, Jun; Han, Guoquan; Chen, Hong; Mao, Qian; Chen, Daiwen

    2013-02-01

    Recently, increasing evidence supports that adult stem cells are the part of a natural system for tissue growth and repair. This study focused on the differences of mesenchymal stem cells from adult adipose (ADSCs), skeletal muscle (MDSCs) and fetal muscle (FMSCs) in biological characteristics, which is the key to cell therapy success. Stem cell antigen 1 (Sca-1) expression of MDSCs and FMSCs at passage 3 was two times more than that at passage 1 (P cells (P fetal muscle expressed higher OCN and OPN than ADSCs after 28 days osteogenic induction (P cell source and developmental stage had great impacts on biological properties of mesenchymal stem cells, and proper consideration of all the issues is necessary.

  3. Why adductor magnus muscle is large: the function based on muscle morphology in cadavers.

    Science.gov (United States)

    Takizawa, M; Suzuki, D; Ito, H; Fujimiya, M; Uchiyama, E

    2014-02-01

    The aim of this study was to examine anatomical properties of the adductor magnus through a detailed classification, and to hypothesize its function and size to gather enough information about morphology. Ten cadaveric specimens of the adductor magnus were used. The muscle was separated into four portios (AM1-AM4) based on the courses of the corresponding perforating arteries, and its volume, muscle length, muscle fiber length and physiological cross-sectional area were assessed. The architectural characteristics of these four portions of the adductor magnus were then classified with the aid of principal component analysis. The results led us into demarcating the most proximal part of the adductor magnus (AM1) from the remaining parts (AM2, AM3, and AM4). Classification of the adductor magnus in terms of architectural characteristics differed from the more traditional anatomical distinction. The AM2, AM3, and AM4, having longer muscle fiber lengths than the AM1, appear to be designed as displacers for moving the thigh through a large range of motion. The AM1 appears instead to be oriented principally toward stabilizing the hip joint. The large mass of the adductor magnus should thus be regarded as a complex of functionally differentiable muscle portions.

  4. Polylysine modification of adenoviral fiber protein enhances muscle cell transduction.

    Science.gov (United States)

    Bouri, K; Feero, W G; Myerburg, M M; Wickham, T J; Kovesdi, I; Hoffman, E P; Clemens, P R

    1999-07-01

    Adenoviral vectors (ADVs) are used widely for gene delivery to different tissues including muscle. One particularly promising use for ADVs is in the transfer of the dystrophin gene to the muscle of patients with Duchenne muscular dystrophy (DMD). However, studies in different animal models of DMD suggest that ADVs inefficiently transduce mature skeletal muscle. In this article we test whether AdZ.F(pK7), a genetically modified ADV that expresses a polylysine moiety on the end of the fiber protein, could enhance transduction of muscle cells and circumvent the maturation-dependent loss of muscle infectivity by ADVs. The efficiency of transduction was tested at different levels of muscle maturation. In vitro, AdZ.F(pK7) showed a higher level of transduction at all stages of differentiation including myoblasts, myotubes, and single muscle fibers. In vivo, mature skeletal muscle was transduced fourfold better by AdZ.F(pK7) than by the unmodifled vector (AdZ.F). Together, these observations demonstrate improved ADV transduction of skeletal muscle by modifying ADV tropism, and provide a proof-of-principle that modification of ADVs to target muscle-specific molecules could result in tissue-specific transfer of skeletal muscle tissue as well.

  5. Vascular function in health, hypertension, and diabetes: effect of physical activity on skeletal muscle microcirculation.

    Science.gov (United States)

    Nyberg, M; Gliemann, L; Hellsten, Y

    2015-12-01

    Regulation of skeletal muscle blood flow is a complex process, which involves an integration of multiple mechanisms and a number of vasoactive compounds. Overall, muscle blood flow is regulated through a balance between vasoconstrictor and vasodilator signals. In a healthy cardiovascular system, the increase in muscle blood flow required for oxygen supply during exercise is achieved through a substantial increase in vasodilators locally formed in the active muscle tissue that overcome the vasoconstrictor signals. Most of the vasodilator signals are mediated via endothelial cells, which lead to the formation of vasodilators such as nitric oxide (NO) and prostacyclin. In essential hypertension and type II diabetes, the endothelial function and regulation of vascular tone is impaired with consequent increases in peripheral vascular resistance and inadequate regulation of oxygen supply to the skeletal muscle, which can affect muscle function. Central aspects in the vascular impairments are alterations in the formation of prostacyclin, the bioavailability of NO and an increased formation of vasoconstrictors and reactive oxygen species (ROS). Regular physical activity effectively improves vascular function by enhancing vasodilator formation and reducing the levels of vasoconstrictors and ROS. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Functional anatomy of the human lateral pterygoid muscle.

    Science.gov (United States)

    El Haddioui, A; Laison, F; Zouaoui, A; Bravetti, P; Gaudy, J F

    2005-11-01

    The authors studied the lateral pterygoid muscle of 179 fresh cadavers by both anatomical dissection and magnetic resonance imaging. The aim was to define the general morphology and the architectural organisation of the lateral pterygoid muscle. Dissection plane by plane, anatomical sections in different planes of space and dissections via multiple approaches on harvested blocks allowed the demonstration that the lateral pterygoid shows an architectural arrangement different from that which is usually described but similar to that, from its typically penniform structure of the masseter and the medial pterygoid. The anatomical situation of this muscle gives rise to numerous differences in opinion much to its morphology as to its functional examination. This study has shown that one part of the muscle has a typical penniform structure made up of alternating musculo-aponeurotic layers and by the absence of individual muscle bellies. In addition the particular shape of this muscle makes it useless to insert intramuscular electrodes in its only accessible portion, which makes the results of electromyographic studies debatable.

  7. 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.

  8. Regulation and functions of the lms homeobox gene during development of embryonic lateral transverse muscles and direct flight muscles in Drosophila.

    Directory of Open Access Journals (Sweden)

    Dominik Müller

    Full Text Available BACKGROUND: Patterning and differentiation of developing musculatures require elaborate networks of transcriptional regulation. In Drosophila, significant progress has been made into identifying the regulators of muscle development and defining their interactive networks. One major family of transcription factors involved in these processes consists of homeodomain proteins. In flies, several members of this family serve as muscle identity genes to specify the fates of individual muscles, or groups thereof, during embryonic and/or adult muscle development. Herein, we report on the expression and function of a new Drosophila homeobox gene during both embryonic and adult muscle development. METHODOLOGY/PRINCIPAL FINDINGS: The newly described homeobox gene, termed lateral muscles scarcer (lms, which has yet uncharacterized orthologs in other invertebrates and primitive chordates but not in vertebrates, is expressed exclusively in subsets of developing muscle tissues. In embryos, lms is expressed specifically in the four lateral transverse (LT muscles and their founder cells in each hemisegment, whereas in larval wing imaginal discs, it is expressed in myoblasts that develop into direct flight muscles (DFMs, which are important for proper wing positioning. We have analyzed the regulatory inputs of various other muscle identity genes with overlapping or complementary expression patterns towards the cell type specific regulation of lms expression. Further we demonstrate that lms null mutants exhibit reduced numbers of embryonic LT muscles, and null mutant adults feature held-out-wing phenotypes. We provide a detailed description of the pattern and morphology of the direct flight muscles in the wild type and lms mutant flies by using the recently-developed ultramicroscopy and show that, in the mutants, all DFMs are present and present normal morphologies. CONCLUSIONS/SIGNIFICANCE: We have identified the homeobox gene lms as a new muscle identity gene

  9. Cited3 activates Mef2c to control muscle cell differentiation and survival.

    Science.gov (United States)

    Devakanmalai, Gnanapackiam Sheela; Zumrut, Hasan E; Ozbudak, Ertuğrul M

    2013-05-15

    Vertebrate muscle development occurs through sequential differentiation of cells residing in somitic mesoderm - a process that is largely governed by transcriptional regulators. Our recent spatiotemporal microarray study in zebrafish has identified functionally uncharacterized transcriptional regulators that are expressed at the initial stages of myogenesis. cited3 is one such novel gene encoding a transcriptional coactivator, which is expressed in the precursors of oxidative slow-twitch myofibers. Our experiments placed cited3 into a gene regulatory network, where it acts downstream of Hedgehog signaling and myoD/myf5 but upstream of mef2c. Knockdown of expression of cited3 by antisense morpholino oligonucleotides impaired muscle cell differentiation and growth, caused muscle cell death and eventually led to total immotility. Transplantation experiments demonstrated that Cited3 cell-autonomously activates the expression of mef2c in slow myofibers, while it non-cell-autonomously regulates expression of structural genes in fast myofibers. Restoring expression of cited3 or mef2c rescued all the cited3 loss-of-function phenotypes. Protein truncation experiments revealed the functional necessity of C-terminally conserved domain of Cited3, which is known to mediate interactions of Cited-family proteins with histone acetylases. Our findings demonstrate that Cited3 is a critical transcriptional coactivator functioning during muscle differentiation and its absence leads to defects in terminal differentiation and survival of muscle cells.

  10. Eccentric exercise facilitates mesenchymal stem cell appearance in skeletal muscle.

    Directory of Open Access Journals (Sweden)

    M Carmen Valero

    Full Text Available Eccentric, or lengthening, contractions result in injury and subsequently stimulate the activation and proliferation of satellite stem cells which are important for skeletal muscle regeneration. The discovery of alternative myogenic progenitors in skeletal muscle raises the question as to whether stem cells other than satellite cells accumulate in muscle in response to exercise and contribute to post-exercise repair and/or growth. In this study, stem cell antigen-1 (Sca-1 positive, non-hematopoetic (CD45⁻ cells were evaluated in wild type (WT and α7 integrin transgenic (α7Tg mouse muscle, which is resistant to injury yet liable to strain, 24 hr following a single bout of eccentric exercise. Sca-1⁺CD45⁻ stem cells were increased 2-fold in WT muscle post-exercise. The α7 integrin regulated the presence of Sca-1⁺ cells, with expansion occurring in α7Tg muscle and minimal cells present in muscle lacking the α7 integrin. Sca-1⁺CD45⁻ cells isolated from α7Tg muscle following exercise were characterized as mesenchymal-like stem cells (mMSCs, predominantly pericytes. In vitro multiaxial strain upregulated mMSC stem cells markers in the presence of laminin, but not gelatin, identifying a potential mechanistic basis for the accumulation of these cells in muscle following exercise. Transplantation of DiI-labeled mMSCs into WT muscle increased Pax7⁺ cells and facilitated formation of eMHC⁺DiI⁻ fibers. This study provides the first demonstration that mMSCs rapidly appear in skeletal muscle in an α7 integrin dependent manner post-exercise, revealing an early event that may be necessary for effective repair and/or growth following exercise. The results from this study also support a role for the α7 integrin and/or mMSCs in molecular- and cellular-based therapeutic strategies that can effectively combat disuse muscle atrophy.

  11. Establishment of bipotent progenitor cell clone from rat skeletal muscle.

    Science.gov (United States)

    Murakami, Yousuke; Yada, Erica; Nakano, Shin-ichi; Miyagoe-Suzuki, Yuko; Hosoyama, Tohru; Matsuwaki, Takashi; Yamanouchi, Keitaro; Nishihara, Masugi

    2011-12-01

    The present study describes the isolation, cloning and characterization of adipogenic progenitor cells from rat skeletal muscle. Among the obtained 10 clones, the most highly adipogenic progenitor, 2G11 cells, were further characterized. In addition to their adipogenicity, 2G11 cells retain myogenic potential as revealed by formation of multinucleated myotubes when co-cultured with myoblasts. 2G11 cells were resistant to an inhibitory effect of basic fibroblast growth factor on adipogenesis, while adipogenesis of widely used preadipogenic cell line, 3T3-L1 cells, was suppressed almost completely by the same treatment. In vivo transplantation experiments revealed that 2G11 cells are able to possess both adipogenicity and myogenicity in vivo. These results indicate the presence of bipotent progenitor cells in rat skeletal muscle, and suggest that such cells may contribute to ectopic fat formation in skeletal muscle.

  12. Live imaging of muscles in Drosophila metamorphosis: Towards high-throughput gene identification and function analysis.

    Science.gov (United States)

    Puah, Wee Choo; Wasser, Martin

    2016-03-01

    Time-lapse microscopy in developmental biology is an emerging tool for functional genomics. Phenotypic effects of gene perturbations can be studied non-invasively at multiple time points in chronological order. During metamorphosis of Drosophila melanogaster, time-lapse microscopy using fluorescent reporters allows visualization of alternative fates of larval muscles, which are a model for the study of genes related to muscle wasting. While doomed muscles enter hormone-induced programmed cell death, a smaller population of persistent muscles survives to adulthood and undergoes morphological remodeling that involves atrophy in early, and hypertrophy in late pupation. We developed a method that combines in vivo imaging, targeted gene perturbation and image analysis to identify and characterize genes involved in muscle development. Macrozoom microscopy helps to screen for interesting muscle phenotypes, while confocal microscopy in multiple locations over 4-5 days produces time-lapse images that are used to quantify changes in cell morphology. Performing a similar investigation using fixed pupal tissues would be too time-consuming and therefore impractical. We describe three applications of our pipeline. First, we show how quantitative microscopy can track and measure morphological changes of muscle throughout metamorphosis and analyze genes involved in atrophy. Second, our assay can help to identify genes that either promote or prevent histolysis of abdominal muscles. Third, we apply our approach to test new fluorescent proteins as live markers for muscle development. We describe mKO2 tagged Cysteine proteinase 1 (Cp1) and Troponin-I (TnI) as examples of proteins showing developmental changes in subcellular localization. Finally, we discuss strategies to improve throughput of our pipeline to permit genome-wide screens in the future.

  13. Skeletal Muscle Function during Exercise—Fine-Tuning of Diverse Subsystems by Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Wilhelm Bloch

    2013-03-01

    Full Text Available Skeletal muscle is responsible for altered acute and chronic workload as induced by exercise. Skeletal muscle adaptations range from immediate change of contractility to structural adaptation to adjust the demanded performance capacities. These processes are regulated by mechanically and metabolically induced signaling pathways, which are more or less involved in all of these regulations. Nitric oxide is one of the central signaling molecules involved in functional and structural adaption in different cell types. It is mainly produced by nitric oxide synthases (NOS and by non-enzymatic pathways also in skeletal muscle. The relevance of a NOS-dependent NO signaling in skeletal muscle is underlined by the differential subcellular expression of NOS1, NOS2, and NOS3, and the alteration of NO production provoked by changes of workload. In skeletal muscle, a variety of highly relevant tasks to maintain skeletal muscle integrity and proper signaling mechanisms during adaptation processes towards mechanical and metabolic stimulations are taken over by NO signaling. The NO signaling can be mediated by cGMP-dependent and -independent signaling, such as S-nitrosylation-dependent modulation of effector molecules involved in contractile and metabolic adaptation to exercise. In this review, we describe the most recent findings of NO signaling in skeletal muscle with a special emphasis on exercise conditions. However, to gain a more detailed understanding of the complex role of NO signaling for functional adaptation of skeletal muscle (during exercise, additional sophisticated studies are needed to provide deeper insights into NO-mediated signaling and the role of non-enzymatic-derived NO in skeletal muscle physiology.

  14. Airway smooth muscle cell proliferation is increased in asthma

    NARCIS (Netherlands)

    Johnson, P R; Roth, Michael; Tamm, M; Hughes, J Margaret; Ge, Q; King, G; Burgess, J K; Black, J L

    2001-01-01

    UNLABELLED: Increased airway smooth muscle (ASM) within the bronchial wall of asthmatic patients has been well documented and is likely to be the result of increased muscle proliferation. We have for the first time been able to culture ASM cells from asthmatic patients and to compare their prolifera

  15. Molecular aging and rejuvenation of human muscle stem cells

    DEFF Research Database (Denmark)

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

    2009-01-01

    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....... 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...

  16. NOV/CCN3 impairs muscle cell commitment and differentiation.

    Science.gov (United States)

    Calhabeu, Frederico; Lafont, Jérome; Le Dreau, Gwenvael; Laurent, Maryvonne; Kazazian, Chantal; Schaeffer, Laurent; Martinerie, Cécile; Dubois, Catherine

    2006-06-10

    NOV (nephroblastoma overexpressed) is a member of a family of proteins which encodes secreted matrix-associated proteins. NOV is expressed during development in dermomyotome and limb buds, but its functions are still poorly defined. In order to understand the role of NOV in myogenic differentiation, C2C12 cells overexpressing NOV (C2-NOV) were generated. These cells failed to engage into myogenic differentiation, whereas they retained the ability to differentiate into osteoblasts. In differentiating conditions, C2-NOV cells remained proliferative, failed to express differentiation markers and lost their ability to form myotubes. Inhibition of differentiation by NOV was also observed with human primary muscle cells. Further examination of C2-NOV cells revealed a strong downregulation of the myogenic determination genes MyoD and Myf5 and of IGF-II expression. MyoD forced expression in C2-NOV was sufficient to restore differentiation and IGF-II induction whereas 10(-6) M insulin treatment had no effects. NOV therefore acts upstream of MyoD and does not affect IGF-II induction and signaling. HES1, a target of Notch, previously proposed to mediate NOV action, was not implicated in the inhibition of differentiation. We propose that NOV is a specific cell fate regulator in the myogenic lineage, acting negatively on key myogenic genes thus controlling the transition from progenitor cells to myoblasts.

  17. Molecular Mechanisms for Exercise Training-Induced Changes in Vascular Structure and Function: Skeletal Muscle, Cardiac Muscle, and the Brain.

    Science.gov (United States)

    Olver, T Dylan; Ferguson, Brian S; Laughlin, M Harold

    2015-01-01

    Compared with resting conditions, during incremental exercise, cardiac output in humans is elevated from ~5 to 25 L min(-1). In conjunction with this increase, the proportion of cardiac output directed toward skeletal muscle increases from ~20% to 85%, while blood flow to cardiac muscle increases 500% and blood flow to specific brain structures increases nearly 200%. Based on existing evidence, researchers believe that blood flow in these tissues is matched to the increases in metabolic rate during exercise. This phenomenon, the matching of blood flow to metabolic requirement, is often referred to as functional hyperemia. This chapter summarizes mechanical and metabolic factors that regulate functional hyperemia as well as other exercise-induced signals, which are also potent stimuli for chronic adaptations in vascular biology. Repeated exposure to exercise-induced increases in shear stress and the induction of angiogenic factors alter vascular cell gene expression and mediate changes in vascular volume and blood flow control. The magnitude and regulation of this coordinated response appear to be tissue specific and coupled to other factors such as hypertrophy and hyperplasia. The cumulative effects of these adaptations contribute to increased exercise capacity, reduced relative challenge of a given submaximal exercise bout and ameliorated vascular outcomes in patient populations with pathological conditions. In the subsequent discussion, this chapter explores exercise as a regulator of vascular biology and summarizes the molecular mechanisms responsible for exercise training-induced changes in vascular structure and function in skeletal and cardiac muscle as well as the brain.

  18. Skeletal Muscle Satellite Cell Activation Following Cutaneous Burn in Rats

    Science.gov (United States)

    2013-12-01

    Satellite cell isolation and culture Satellite cells were isolated similar as described by Allen et al. [30]. Following euthanasia , muscles were...satellite cell cultures. Methods Cell Biol 1997;52:155–76. [31] Tatsumi R, Liu X, Pulido A, Morales M, Sakata T, Dial S, Hattori A, Ikeuchi Y, Allen RE

  19. Lower limb examinations for muscular tension estimation methods for each muscle group based on functionally different effective muscle theory.

    Science.gov (United States)

    Nishii, Taiki; Komada, Satoshi; Yashiro, Daisuke; Hirai, Junji

    2013-01-01

    Conventional estimation methods distribute tension to muscles by solving optimization problems, because the system is redundant. The theory of functionally different effective muscle, based on 3 antagonistic pairs of muscle groups in limbs, has enabled to calculate the maximum joint torque of each pair, i.e. functionally different effective muscle force. Based on this theory, a method to estimate muscular tension has been proposed, where joint torque of each muscle group is derived by multiplying functionally different effective muscle force, the muscular activity of muscular activity pattern for direction of tip force, and ratio of tip force to maximum output force. The estimation of this method is as good as Crowninshield's method, moreover this method also reduce the computation time if the estimation concerns a selected muscle group.

  20. Organization of organelles and VAMP-associated vesicular transport systems in differentiating skeletal muscle cells.

    Science.gov (United States)

    Tajika, Yuki; Takahashi, Maiko; Ueno, Hitoshi; Murakami, Tohru; Yorifuji, Hiroshi

    2015-01-01

    Vesicular transport plays an important role in the regulation of cellular function and differentiation of the cell, and intracellular vesicles play a role in the delivery of membrane components and in sorting membrane proteins to appropriate domains in organelles and the plasma membrane. Research on vesicular transport in differentiating cells has mostly focused on neurons and epithelial cells, and few such studies have been carried out on skeletal muscle cells. Skeletal muscle cells have specialized organelles and plasma membrane domains, including T-tubules, sarcoplasmic reticulum, neuromuscular junctions, and myotendinous junctions. The differentiation of skeletal muscle cells is achieved by multiple steps, i.e., proliferation of myoblasts, formation of myotubes by cell-cell fusion, and maturation of myotubes into myofibers. Systematic vesicular transport is expected to play a role in the maintenance and development of skeletal muscle cells. Here, we review a map of the vesicular transport system during the differentiation of skeletal muscle cells. The characteristics of organelle arrangement in myotubes are described according to morphological studies. Vesicular transport in myotubes is explained by the expression profiles of soluble N-ethylmaleimide-sensitive factor attachment protein receptor proteins.

  1. Dynamic reconstruction of eye closure by muscle transposition or functional muscle transplantation in facial palsy.

    Science.gov (United States)

    Frey, Manfred; Giovanoli, Pietro; Tzou, Chieh-Han John; Kropf, Nina; Friedl, Susanne

    2004-09-15

    For patients with facial palsy, lagophthalmus is often a more serious problem than the inability to smile. Dynamic reconstruction of eye closure by muscle transposition or by free functional muscle transplantation offers a good solution for regaining near-normal eye protection without the need for implants. This is the first quantitative study of three-dimensional preoperative and postoperative lid movements in patients treated for facial paralysis. Between February of 1998 and April of 2002, 44 patients were treated for facial palsy, including reconstruction of eye closure. Temporalis muscle transposition to the eye was used in 34 cases, and a regionally differentiated part of a free gracilis muscle transplant after double cross-face nerve grafting was used in 10 cases. Patients' facial movements were documented by a three-dimensional video analysis system preoperatively and 6, 12, 18, and 24 months postoperatively. For this comparative study, only the data of patients with preoperative and 12-month postoperative measurements were included. In the 27 patients with a final result after temporalis muscle transposition for eye closure, the distance between the upper and lower eyelid points during eye closing (as for sleep) was reduced from 10.33 +/- 2.43 mm (mean +/- SD) preoperatively to 5.84 +/- 4.34 mm postoperatively on the paralyzed side, compared with 0.0 +/- 0.0 mm preoperatively and postoperatively on the contralateral healthy side. In the resting position, preoperative values for the paralyzed side changed from 15.11 +/- 1.92 mm preoperatively to 13.46 +/- 1.94 mm postoperatively, compared with 12.17 +/- 2.02 mm preoperatively and 12.05 +/- 1.95 mm postoperatively on the healthy side. In the nine patients with a final result after surgery using a part of the free gracilis muscle transplant reinnervated by a zygomatic branch of the contralateral healthy side through a cross-face nerve graft, eyelid closure changed from 10.21 +/- 2.72 mm to 1.68 +/- 1.35 mm

  2. Postoperative Recovery of Mechanical Muscle Function in Hip Replacement Patients

    DEFF Research Database (Denmark)

    Jensen, Carsten; Aagaard, Per; Overgaard, Søren

    2011-01-01

    INTRODUCTION Muscle function in patients with hip osteoarthritis (OA) is not well-studied. We established a new setup of tests in order to monitor patients before and after surgery. Our novel setup was used to evaluate single- and multi-joint strength (torque) and power in a group of 40 – 65 year...... weeks post surgery for both the affected (AF) as well as the non-affected (NA) side. Protocol: All contractions were performed ad libitum and for each muscle group 3 trails of 4s duration were performed. The trail with highest peak torque was used for further analysis. Statistics: Paired students t...

  3. Whole-cell recordings of calcium and potassium currents in acutely isolated smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    Qing Cai; Zhong-Liang Zhu; Xiao-Li Fan

    2006-01-01

    AIM: To record calcium and potassium currents in acutely isolated smooth muscle cells of mesenteric arterial branches in rats.METHODS: Smooth muscle cells were freshly isolated by collagenase digest and mechanical trituration with polished pipettes. Patch clamp technique in whole-cell mode was employed to record calcium and potassium currents.RESULTS: The procedure dissociated smooth muscle cells without impairing the electrophysiological characteristics of the cells. The voltage-gated Ca2+ and potassium currents were successfully recorded using whole-cell patch clamp configuration.CONCLUSION: The method dissociates smooth muscle cells from rat mesenteric arterial branches. Voltage-gated channel currents can be recorded in this preparation.

  4. [Iliopsoas muscle syndrome. Functional disorders: shortening, spasm and weakness of a structurally unchanged muscle].

    Science.gov (United States)

    Grgić, Vjekoslav

    2009-01-01

    Functional (non-organic) disorders of the iliopsoas muscle (IPM), i.e. the shortening, spasm and weakness of the structurally unchanged IPM, can be manifested as abdominal and/or pelvic pain, pain in areas of the thoracolumbar (ThL) and lumbosacral (LS) spine, sacroiliac (SI) joint, hip, groin and anterior thigh on the side of the affected muscle as well as gait disturbances (iliopsoas muscle syndrome). By clinical examination of the IPM, including the transabdominal palpation, stretch and strength tests, pathological masses, shortening, painful spasm, weakness and tendon tenderness of that muscle can be diagnosed. The IPM is, like other postural muscles, inclined to shortening. The weakness of the IPM can be a consequence of the lesion of the lumbar plexus or femoral nerve that innervate the IPM, as well as a consequence of certain organic diseases of the IPM. Painful stimuli coming from somatic and visceral structures that are innervated from Th12-L4 nerve roots, from which the IPM segmental innervation also originates, can cause a reflex spasm of the IPM. A painful spasm of the IPM caused by disorders of the ThL and LS spine, SI and hip joint, can mimic diseases of the abdominal and pelvic organs. In the differential diagnosis of the IPM painful spasm, organic diseases of that muscle should be considered foremost (abscess, hematoma, tumor, metastase), as they can result in spasm, and the diseases of the abdominal and pelvic organs that can cause an IPM reflex spasm. The IPM functional disorders, which are not rare, are often overlooked during a clinical examination of a patient. Reasons for overlooking these disorders are: 1) a nonspecific and variable clinical picture presenting the IPM functional disorders, 2) the IPM functional disorders are a neglected source of pain, 3) the inaccessibility of the IPM for inspection, 4) the lack of knowledge of the IPM examination techniques and 5) the IPM functional disorders cannot be discovered by radiological

  5. Desmin: molecular interactions and putative functions of the muscle intermediate filament protein

    Directory of Open Access Journals (Sweden)

    M.L. Costa

    2004-12-01

    Full Text Available Desmin is the intermediate filament (IF protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin, and vimentin, besides the ubiquitous lamins, but they are not unique to muscle. Desmin was purified in 1977, the desmin gene was characterized in 1989, and knock-out animals were generated in 1996. Several isoforms have been described. Desmin IFs are present throughout smooth, cardiac and skeletal muscle cells, but can be more concentrated in some particular structures, such as dense bodies, around the nuclei, around the Z-line or in costameres. Desmin is up-regulated in muscle-derived cellular adaptations, including conductive fibers in the heart, electric organs, some myopathies, and experimental treatments with drugs that induce muscle degeneration, like phorbol esters. Many molecules have been reported to associate with desmin, such as other IF proteins (including members of the membrane dystroglycan complex, nebulin, the actin and tubulin binding protein plectin, the molecular motor dynein, the gene regulatory protein MyoD, DNA, the chaperone alphaB-crystallin, and proteases such as calpain and caspase. Desmin has an important medical role, since it is used as a marker of tumors' origin. More recently, several myopathies have been described, with accumulation of desmin deposits. Yet, after almost 30 years since its identification, the function of desmin is still unclear. Suggested functions include myofibrillogenesis, mechanical support for the muscle, mitochondrial localization, gene expression regulation, and intracellular signaling. This review focuses on the biochemical interactions of desmin, with a discussion of its putative functions.

  6. 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.

  7. Human Satellite Cell Transplantation and Regeneration from Diverse Skeletal Muscles

    Directory of Open Access Journals (Sweden)

    Xiaoti Xu

    2015-09-01

    Full Text Available Identification of human satellite cells that fulfill muscle stem cell criteria is an unmet need in regenerative medicine. This hurdle limits understanding how closely muscle stem cell properties are conserved among mice and humans and hampers translational efforts in muscle regeneration. Here, we report that PAX7 satellite cells exist at a consistent frequency of 2–4 cells/mm of fiber in muscles of the human trunk, limbs, and head. Xenotransplantation into mice of 50–70 fiber-associated, or 1,000–5,000 FACS-enriched CD56+/CD29+ human satellite cells led to stable engraftment and formation of human-derived myofibers. Human cells with characteristic PAX7, CD56, and CD29 expression patterns populated the satellite cell niche beneath the basal lamina on the periphery of regenerated fibers. After additional injury, transplanted satellite cells robustly regenerated to form hundreds of human-derived fibers. Together, these findings conclusively delineate a source of bona-fide endogenous human muscle stem cells that will aid development of clinical applications.

  8. Recovery in skeletal muscle contractile function after prolonged hindlimb immobilization

    Science.gov (United States)

    Fitts, R. H.; Brimmer, C. J.

    1985-01-01

    The effect of three-month hindlimb immobilization (IM) in rats on contractile properties of slow-twitch soleus (SOL), fast-twitch extensor digitorum longus, and fast-twitch superficial region of the vastus lateralis were measured after 0, 14, 28, 60, and 90 days of recovery on excized, horizontally suspended muscles stimulated electrically to maximal twitch tension. IM caused decreases in muscle-to-body weight ratios for all muscles, with no complete recovery even after 90 days. The contractile properties of the fast-twitch muscles were less affected by IM than those of the slow-twitch SOL. The SOL isometric twitch duration was shortened, due to reduced contraction and half-relaxation time, both of which returned to control levels after 14 days of recovery. The peak tetanic tension, P(O), g/sq cm,, decreased with IM by 46 percent in the SOL, but recovered by the 28th day. The maximum shortening velocity was not altered by IM in any of the muscles. Thus, normal contractile function could recover after prolonged limb IM.

  9. Genetically enhancing mitochondrial antioxidant activity improves muscle function in aging.

    Science.gov (United States)

    Umanskaya, Alisa; Santulli, Gaetano; Xie, Wenjun; Andersson, Daniel C; Reiken, Steven R; Marks, Andrew R

    2014-10-21

    Age-related skeletal muscle dysfunction is a leading cause of morbidity that affects up to half the population aged 80 or greater. Here we tested the effects of increased mitochondrial antioxidant activity on age-dependent skeletal muscle dysfunction using transgenic mice with targeted overexpression of the human catalase gene to mitochondria (MCat mice). Aged MCat mice exhibited improved voluntary exercise, increased skeletal muscle specific force and tetanic Ca(2+) transients, decreased intracellular Ca(2+) leak and increased sarcoplasmic reticulum (SR) Ca(2+) load compared with age-matched wild type (WT) littermates. Furthermore, ryanodine receptor 1 (the sarcoplasmic reticulum Ca(2+) release channel required for skeletal muscle contraction; RyR1) from aged MCat mice was less oxidized, depleted of the channel stabilizing subunit, calstabin1, and displayed increased single channel open probability (Po). Overall, these data indicate a direct role for mitochondrial free radicals in promoting the pathological intracellular Ca(2+) leak that underlies age-dependent loss of skeletal muscle function. This study harbors implications for the development of novel therapeutic strategies, including mitochondria-targeted antioxidants for treatment of mitochondrial myopathies and other healthspan-limiting disorders.

  10. Skeletal muscle microvascular function in girls with Turner syndrome

    Science.gov (United States)

    West, Sarah L.; O'Gorman, Clodagh S.; Elzibak, Alyaa H.; Caterini, Jessica; Noseworthy, Michael D.; Rayner, Tammy; Hamilton, Jill; Wells, Greg D.

    2014-01-01

    Background Exercise intolerance is prevalent in individuals with Turner Syndrome (TS). We recently demonstrated that girls with TS have normal aerobic but altered skeletal muscle anaerobic metabolism compared to healthy controls (HC). The purpose of this study was to compare peripheral skeletal muscle microvascular function in girls with TS to HC after exercise. We hypothesized that girls with TS would have similar muscle blood-oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) signal responses during recovery from exercise compared to HC. Methods Thirteen TS participants and 8 HC completed testing. BOLD MRI was used to measure skeletal muscle microvascular response during 60 second recovery, following 60 s of exercise at 65% of maximal workload. Exercise and recovery were repeated four times, and the BOLD signal time course was fit to a four-parameter sigmoid function. Results Participants were 13.7 ± 3.1 years old and weighed 47.9 ± 14.6 kg. The mean change in BOLD signal intensity following exercise at the end of recovery, the mean response time of the function/the washout of deoxyhemoglobin, and the mean half-time of recovery were similar between the TS and HC groups. Conclusions Our results demonstrate that compared to HC, peripheral skeletal muscle microvascular function following exercise in girls with TS is not impaired. General significance This study supports the idea that the aerobic energy pathway is not impaired in children with TS in response to submaximal exercise. Other mechanisms are likely responsible for exercise intolerance in TS; this needs to be further investigated. PMID:26676172

  11. THE IMPROVEMENT OF INFARCTED MYOCARDIAL CONTRACTILE FORCE AFTER AUTOLOGOUS SKELETAL MUSCLE SATELLITE CELL IMPLANTATION

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 张臻

    2002-01-01

    Objective To study the improvement of infarcted myocardial contractile force after autologous skeletal muscle satellite cell implantation via intracoronary arterial perfusion. Methods Skeletal muscle cells were harvested from gluteus max of adult mongrel dogs and the cells were cultured and expanded before being labeled with DAPI (4, 6-diamidino-2-phenylindone). The labeled cells were then implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) coronary artery. Specimens were taken at 2nd, 4th, 8th week after myoblast implantation for histologic and contractile force evaluation, respectively. Results The satellite cells with fluorescence had been observed in the infarct site and also in papi-llary muscle with consistent oriented direction of host myocardium. A portion of the implanted cells had differen-tiated into muscle fibers. Two weeks after implantation, the myocardial contractile force showed no significant difference between the cell implant group and control group. At 4 and 8 week, the contractile force in the cell implant group was better than that in control group. Conclusion The skeletal muscle satellite cells, implanted into infarct myocardium by intracoronary arterial perfusion, could disseminate through the entire infarcted zone with myocardial regeneration and improve the contractile function of the infarcted myocardium.

  12. Localized muscle vibration reverses quadriceps muscle hypotrophy and improves physical function: a clinical and electrophysiological study.

    Science.gov (United States)

    Benedetti, Maria Grazia; Boccia, Gennaro; Cavazzuti, Lorenzo; Magnani, Elena; Mariani, Elisabetta; Rainoldi, Alberto; Casale, Roberto

    2017-07-18

    Quadriceps weakness has been associated with knee osteoarthritis (OA). High-frequency localized muscle vibration (LMV) has been proposed recently for quadriceps strengthening in patients with knee OA. The purpose of this study was (a) to investigate the clinical effectiveness of high-frequency LMV on quadriceps muscle in patients with knee OA and (b) to disentangle, by means of surface electromyography (sEMG), the underlying mechanism. Thirty patients, aged between 40 and 65 years, and clinically diagnosed with knee OA were included in this randomized, controlled, single-blinded pilot study. Participants were randomly assigned to two groups: a study group treated with LMV, specifically set for muscle strengthening (150 Hz), by means of a commercial device VIBRA, and a control group treated with neuromuscular electrical stimulation. Clinical outcome was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, Visual Analogue Scale, knee range of motion, Timed Up and Go test, and Stair climbing test. To assess changes in muscle activation and fatigue a subgroup of 20 patients was studied with the use of sEMG during a sustained isometric contraction. The LMV group showed a significant change in Western Ontario and McMaster Universities Osteoarthritis Index score, Visual Analogue Scale score, Timed Up and Go test, Stair Climbing Test, and knee flexion. These improvements were not significant in patients treated with neuromuscular electrical stimulation. sEMG analysis suggested an increased involvement of type II muscle fibers in the group treated with LMV. In conclusion, the present study supports the effectiveness of local vibration in muscle function and clinical improvement of patients with knee OA.

  13. Tobacco constituents are mitogenic for arterial smooth-muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.G.; Hajjar, D.P.; Hefton, J.M.

    1985-07-01

    Tobacco glycoprotein (TGP) purified from flue-cured tobacco leaves, tar-derived material (TAR), the water soluble, nondialyzable, delipidized extract of cigarette smoke condensate, rutin-bovine serum albumin conjugates, quercetin, and chlorogenic acid are mitogenic for bovine aortic smooth-muscle cells, but not adventitial fibroblasts. The mitogenicity appears to depend on polyphenol epitopes on carrier molecules. Ellagic acid, another plant polyphenol, inhibited arterial smooth-muscle proliferation. These results suggest that a number of ubiquitous, plant-derived substances may influence smooth-muscle cell proliferation in the arterial wall.

  14. Exosomes from differentiating human skeletal muscle cells trigger myogenesis of stem cells and provide biochemical cues for skeletal muscle regeneration.

    Science.gov (United States)

    Choi, Ji Suk; Yoon, Hwa In; Lee, Kyoung Soo; Choi, Young Chan; Yang, Seong Hyun; Kim, In-San; Cho, Yong Woo

    2016-01-28

    Exosomes released from skeletal muscle cells play important roles in myogenesis and muscle development via the transfer of specific signal molecules. In this study, we investigated whether exosomes secreted during myotube differentiation from human skeletal myoblasts (HSkM) could induce a cellular response from human adipose-derived stem cells (HASCs) and enhance muscle regeneration in a muscle laceration mouse model. The exosomes contained various signal molecules including myogenic growth factors related to muscle development, such as insulin-like growth factors (IGFs), hepatocyte growth factor (HGF), fibroblast growth factor-2 (FGF2), and platelet-derived growth factor-AA (PDGF-AA). Interestingly, exosome-treated HASCs fused with neighboring cells at early time points and exhibited a myotube-like phenotype with increased expression of myogenic proteins (myosin heavy chain and desmin). On day 21, mRNAs of terminal myogenic genes were also up-regulated in exosome-treated HASCs. Moreover, in vivo studies demonstrated that exosomes from differentiating HSkM reduced the fibrotic area and increased the number of regenerated myofibers in the injury site, resulting in significant improvement of skeletal muscle regeneration. Our findings suggest that exosomes act as a biochemical cue directing stem cell differentiation and provide a cell-free therapeutic approach for muscle regeneration.

  15. Decline of cell viability and mitochondrial activity in mouse skeletal muscle cell in a hypomagnetic field.

    Science.gov (United States)

    Fu, Jing-Peng; Mo, Wei-Chuan; Liu, Ying; He, Rong-Qiao

    2016-05-01

    Hypomagnetic field (HMF), one of the key environmental risk factors for astronauts traveling in outer space, has previously been shown to repress locomotion of mammalians. However, underlying mechanisms of how HMF affects the motor system remains poorly understood. In this study, we created an HMF (<3 μT) by eliminating geomagnetic field (GMF, ∼50 μT) and exposed primary mouse skeletal muscle cells to this low magnetic field condition for a period of three days. HMF-exposed cells showed a decline in cell viability relative to GMF control, even though cells appeared normal in terms of morphology and survival rate. After a 3-day HMF-exposure, glucose consumption of skeletal muscle cells was significantly lower than GMF control, accompanied by less adenosine triphosphate (ATP) and adenosine diphosphate (ADP) content and higher ADP/ATP ratio. In agreement with these findings, mitochondrial membrane potential of HMF-exposed cells was also lower, whereas levels of cellular Reactive Oxygen Species were higher. Moreover, viability and membrane potential of isolated mitochondria were reduced after 1 h HMF-exposure in vitro. Our results indicate that mitochondria can directly respond to HMF at functional level, and suggest that HMF-induced decline in cell functionality results from a reduction in energy production and mitochondrial activity.

  16. Independent specialisation of myosin II paralogues in muscle vs. non-muscle functions during early animal evolution: a ctenophore perspective

    Directory of Open Access Journals (Sweden)

    Dayraud Cyrielle

    2012-07-01

    Full Text Available Abstract Background Myosin II (or Myosin Heavy Chain II, MHCII is a family of molecular motors involved in the contractile activity of animal muscle cells but also in various other cellular processes in non-muscle cells. Previous phylogenetic analyses of bilaterian MHCII genes identified two main clades associated respectively with smooth/non-muscle cells (MHCIIa and striated muscle cells (MHCIIb. Muscle cells are generally thought to have originated only once in ancient animal history, and decisive insights about their early evolution are expected to come from expression studies of Myosin II genes in the two non-bilaterian phyla that possess muscles, the Cnidaria and Ctenophora. Results We have uncovered three MHCII paralogues in the ctenophore species Pleurobrachia pileus. Phylogenetic analyses indicate that the MHCIIa / MHCIIb duplication is more ancient than the divergence between extant metazoan lineages. The ctenophore MHCIIa gene (PpiMHCIIa has an expression pattern akin to that of "stem cell markers" (Piwi, Vasa… and is expressed in proliferating cells. We identified two MHCIIb genes that originated from a ctenophore-specific duplication. PpiMHCIIb1 represents the exclusively muscular form of myosin II in ctenophore, while PpiMHCIIb2 is expressed in non-muscle cells of various types. In parallel, our phalloidin staining and TEM observations highlight the structural complexity of ctenophore musculature and emphasize the experimental interest of the ctenophore tentacle root, in which myogenesis is spatially ordered and strikingly similar to striated muscle formation in vertebrates. Conclusion MHCIIa expression in putative stem cells/proliferating cells probably represents an ancestral trait, while specific involvement of some MHCIIa genes in smooth muscle fibres is a uniquely derived feature of the vertebrates. That one ctenophore MHCIIb paralogue (PpiMHCIIb2 has retained MHCIIa-like expression features furthermore suggests that muscular

  17. Abdominal muscle function and incisional hernia: a systematic review.

    Science.gov (United States)

    Jensen, K K; Kjaer, M; Jorgensen, L N

    2014-08-01

    Although ventral incisional hernia (VIH) repair in patients is often evaluated in terms of hernia recurrence rate and health-related quality of life, there is no clear consensus regarding optimal operative treatment based on these parameters. It was proposed that health-related quality of life depends largely on abdominal muscle function (AMF), and the present review thus evaluates to what extent AMF is influenced by VIH and surgical repair. The PubMed and EMBASE databases were searched for articles following a systematic strategy for inclusion. A total of seven studies described AMF in relation to VIH. Five studies examined AMF using objective isokinetic dynamometers to determine muscle strength, and two studies examined AMF by clinical examination-based muscle tests. Both equipment-related and functional muscle tests exist for use in patients with VIH, but very few studies have evaluated AMF in VIH. There are no randomized controlled studies to describe the impact of VIH repair on AMF, and no optimal surgical treatment in relation to AMF after VIH repair can be advocated for at this time.

  18. Ultrastructure of interstitial cells of Cajal in circular muscle of human small intestine

    DEFF Research Database (Denmark)

    Rumessen, J J; Mikkelsen, H B; Qvortrup, Klaus;

    1993-01-01

    Interstitial cells of Cajal (ICC) may be important regulatory cells in gut muscle layers. This study examined ICC within the circular muscle of human small intestine.......Interstitial cells of Cajal (ICC) may be important regulatory cells in gut muscle layers. This study examined ICC within the circular muscle of human small intestine....

  19. Adhesion and Fusion of Muscle Cells Are Promoted by Filopodia.

    Science.gov (United States)

    Segal, Dagan; Dhanyasi, Nagaraju; Schejter, Eyal D; Shilo, Ben-Zion

    2016-08-01

    Indirect flight muscles (IFMs) in Drosophila are generated during pupariation by fusion of hundreds of myoblasts with larval muscle templates (myotubes). Live observation of these muscles during the fusion process revealed multiple long actin-based protrusions that emanate from the myotube surface and require Enabled and IRSp53 for their generation and maintenance. Fusion is blocked when formation of these filopodia is compromised. While filopodia are not required for the signaling process underlying critical myoblast cell-fate changes prior to fusion, myotube-myoblast adhesion appears to be filopodia dependent. Without filopodia, close apposition between the cell membranes is not achieved, the cell-adhesion molecule Duf is not recruited to the myotube surface, and adhesion-dependent actin foci do not form. We therefore propose that the filopodia are necessary to prime the heterotypic adhesion process between the two cell types, possibly by recruiting the cell-adhesion molecule Sns to discrete patches on the myoblast cell surface.

  20. Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

    DEFF Research Database (Denmark)

    Hvid, Lars; Aagaard, Per; Justesen, Lene;

    2010-01-01

    Very little attention has been given to the combined effects of aging and disuse as separate factors causing deterioration in muscle mechanical function. Thus the purpose of this study was to investigate the effects of 2 wk of immobilization followed by 4 wk of retraining on knee extensor muscle...... to the deleterious effects of short-term muscle disuse on muscle fiber size and rapid force capacity than YM. Furthermore, OM seems to require longer time to recover and regain rapid muscle force capacity, which may lead to a larger risk of falling in aged individuals after periods of short-term disuse....

  1. Extracellular proteolysis and the migrating vascular smooth muscle cell

    NARCIS (Netherlands)

    Leeuwen, R.T.J. van

    1996-01-01

    Smooth muscle cells (SMC) form the major cell type in the arterial blood vessels. In the undamaged vessel wall they remain in a contractile state characterized by the absence of cell division, a low metabolic activity and a high actin-myosin content. As a reaction to injury of the vessel wall they c

  2. Kinesiophobia, Pain, Muscle Functions, and Functional Performances among Older Persons with Low Back Pain

    Directory of Open Access Journals (Sweden)

    Nor Azizah Ishak

    2017-01-01

    Full Text Available Objectives. This study aims (1 to determine the association between kinesiophobia and pain, muscle functions, and functional performances and (2 to determine whether kinesiophobia predicts pain, muscle functions, and functional performance among older persons with low back pain (LBP. Methods. This is a correlational study, involving 63 institutionalized older persons (age = 70.98±7.90 years diagnosed with LBP. Anthropometric characteristics (BMI and functional performances (lower limb function, balance and mobility, and hand grip strength were measured. Muscle strength (abdominal and back muscle strength was assessed using the Baseline® Mechanical Push/Pull Dynamometer, while muscle control (transverse abdominus and multifidus was measured by using the Pressure Biofeedback Unit. The pain intensity and the level of kinesiophobia were measured using Numerical Rating Scale and Tampa Scale of Kinesiophobia, respectively. Data were analyzed using Pearson’s correlation coefficients and multivariate linear regressions. Results. No significant correlations were found between kinesiophobia and pain and muscle functions (all p>0.05. Kinesiophobia was significantly correlated with mobility and balance (p=0.038, r=0.263. Regressions analysis showed that kinesiophobia was a significant predictor of mobility and balance (p=0.038. Conclusion. We can conclude that kinesiophobia predicted mobility and balance in older persons with LBP. Kinesiophobia should be continuously assessed in clinical settings to recognize the obstacles that may affect patient’s compliance towards a rehabilitation program in older persons with LBP.

  3. Epigenetic stress responses induce muscle stem-cell ageing by Hoxa9 developmental signals.

    Science.gov (United States)

    Schwörer, Simon; Becker, Friedrich; Feller, Christian; Baig, Ali H; Köber, Ute; Henze, Henriette; Kraus, Johann M; Xin, Beibei; Lechel, André; Lipka, Daniel B; Varghese, Christy S; Schmidt, Manuel; Rohs, Remo; Aebersold, Ruedi; Medina, Kay L; Kestler, Hans A; Neri, Francesco; von Maltzahn, Julia; Tümpel, Stefan; Rudolph, K Lenhard

    2016-12-15

    The functionality of stem cells declines during ageing, and this decline contributes to ageing-associated impairments in tissue regeneration and function. Alterations in developmental pathways have been associated with declines in stem-cell function during ageing, but the nature of this process remains poorly understood. Hox genes are key regulators of stem cells and tissue patterning during embryogenesis with an unknown role in ageing. Here we show that the epigenetic stress response in muscle stem cells (also known as satellite cells) differs between aged and young mice. The alteration includes aberrant global and site-specific induction of active chromatin marks in activated satellite cells from aged mice, resulting in the specific induction of Hoxa9 but not other Hox genes. Hoxa9 in turn activates several developmental pathways and represents a decisive factor that separates satellite cell gene expression in aged mice from that in young mice. The activated pathways include most of the currently known inhibitors of satellite cell function in ageing muscle, including Wnt, TGFβ, JAK/STAT and senescence signalling. Inhibition of aberrant chromatin activation or deletion of Hoxa9 improves satellite cell function and muscle regeneration in aged mice, whereas overexpression of Hoxa9 mimics ageing-associated defects in satellite cells from young mice, which can be rescued by the inhibition of Hoxa9-targeted developmental pathways. Together, these data delineate an altered epigenetic stress response in activated satellite cells from aged mice, which limits satellite cell function and muscle regeneration by Hoxa9-dependent activation of developmental pathways.

  4. Epigenetic Control of Smooth Muscle Cell Identity and Lineage Memory.

    Science.gov (United States)

    Gomez, Delphine; Swiatlowska, Pamela; Owens, Gary K

    2015-12-01

    Vascular smooth muscle cells (SMCs), like all cells, acquire a cell-specific epigenetic signature during development that includes acquisition of a unique repertoire of histone and DNA modifications. These changes are postulated to induce an open chromatin state (referred to as euchromatin) on the repertoire of genes that are expressed in differentiated SMC, including SMC-selective marker genes like Acta2 and Myh11, as well as housekeeping genes expressed by most cell types. In contrast, genes that are silenced in differentiated SMC acquire modifications associated with a closed chromatin state (ie, heterochromatin) and transcriptional silencing. Herein, we review mechanisms that regulate epigenetic control of the differentiated state of SMC. In addition, we identify some of the major limitations in the field and future challenges, including development of innovative new tools and approaches, for performing single-cell epigenetic assays and locus-selective editing of the epigenome that will allow direct studies of the functional role of specific epigenetic controls during development, injury repair, and disease, including major cardiovascular diseases, such as atherosclerosis, hypertension, and microvascular disease, associated with diabetes mellitus.

  5. Electrical Stimulation of Embryonic Neurons for 1 Hour Improves Axon Regeneration and the Number of Reinnervated Muscles that Function

    Science.gov (United States)

    Liu, Yang; Grumbles, Robert M.; Thomas, Christine K.

    2013-01-01

    Motoneuron death following spinal cord injury or disease results in muscle denervation, atrophy, and paralysis. We have previously transplanted embryonic ventral spinal cord cells into peripheral nerve to reinnervate denervated muscles and to reduce muscle atrophy, but reinnervation was incomplete. Here, our aim was to determine whether brief electrical stimulation of embryonic neurons in peripheral nerve changes motoneuron survival, axon regeneration, and muscle reinnervation and function because neural depolarization is crucial for embryonic neuron survival and may promote activity-dependent axon growth. At 1 week after denervation by sciatic nerve section, embryonic day 14-15 cells were purified for motoneurons, injected into the tibial nerve of adult Fischer rats, and stimulated immediately for up to 1 hour. More myelinated axons were present in tibial nerves when transplants had been stimulated at 1 Hz for 1 hour at 10 weeks following transplantation. More muscles were reinnervated if the stimulation treatment lasted for 1 hour. Reinnervation reduced muscle atrophy, with or without the stimulation treatment. These data suggest that brief stimulation of embryonic neurons promotes axon growth, which has a long-term impact on muscle reinnervation and function. Muscle reinnervation is important because it may enable the use of functional electrical stimulation to restore limb movements. PMID:23771218

  6. Bridging long gap peripheral nerve injury using skeletal muscle-derived multipotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Tetsuro Tamaki

    2014-01-01

    Long gap peripheral nerve injuries usually reulting in life-changing problems for patients. Skeletal muscle derived-multipotent stem cells (Sk-MSCs) can differentiate into Schwann and perineurial/endoneurial cells, vascular relating pericytes, and endothelial and smooth muscle cells in the damaged peripheral nerve niche. Application of the Sk-MSCs in the bridging conduit for repairing long nerve gap injury resulted favorable axonal regeneration, which showing supe-rior effects than gold standard therapy--healthy nerve autograft. This means that it does not need to sacriifce of healthy nerves or loss of related functions for repairing peripheral nerve injury.

  7. A function for filamentous alpha-smooth muscle actin: Retardation of motility in human breast fibroblasts

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Petersen, Ole William

    1996-01-01

    Actins are known to comprise six mammalian isoforms of which beta- and gamma-nonmuscle actins are present in all cells, whereas alpha-smooth muscle (alpha-sm) actin is normally restricted to cells of the smooth muscle lineages. alpha-Sm actin has been found also to be expressed transiently...... reactions. Here, we show that the presence of alpha-sm actin is a signal for retardation of migratory behavior in fibroblasts. Comparison in a migration assay of fibroblast cell strains with and without alpha-sm actin revealed migratory restraint in alpha-sm actin-positive fibroblasts. Electroporation...... in certain nonmuscle cells, in particular fibroblasts, which are referred to as myofibroblasts. The functional significance of alpha-sm actin in fibroblasts is unknown. However, myofibroblasts appear to play a prominent role in stromal reaction in breast cancer, at the site of wound repair, and in fibrotic...

  8. Skeletal muscle cells express ICAM-1 after muscle overload and ICAM-1 contributes to the ensuing hypertrophic response.

    Directory of Open Access Journals (Sweden)

    Christopher L Dearth

    Full Text Available We previously reported that leukocyte specific β2 integrins contribute to hypertrophy after muscle overload in mice. Because intercellular adhesion molecule-1 (ICAM-1 is an important ligand for β2 integrins, we examined ICAM-1 expression by murine skeletal muscle cells after muscle overload and its contribution to the ensuing hypertrophic response. Myofibers in control muscles of wild type mice and cultures of skeletal muscle cells (primary and C2C12 did not express ICAM-1. Overload of wild type plantaris muscles caused myofibers and satellite cells/myoblasts to express ICAM-1. Increased expression of ICAM-1 after muscle overload occurred via a β2 integrin independent mechanism as indicated by similar gene and protein expression of ICAM-1 between wild type and β2 integrin deficient (CD18-/- mice. ICAM-1 contributed to muscle hypertrophy as demonstrated by greater (p<0.05 overload-induced elevations in muscle protein synthesis, mass, total protein, and myofiber size in wild type compared to ICAM-1-/- mice. Furthermore, expression of ICAM-1 altered (p<0.05 the temporal pattern of Pax7 expression, a marker of satellite cells/myoblasts, and regenerating myofiber formation in overloaded muscles. In conclusion, ICAM-1 expression by myofibers and satellite cells/myoblasts after muscle overload could serve as a mechanism by which ICAM-1 promotes hypertrophy by providing a means for cell-to-cell communication with β2 integrin expressing myeloid cells.

  9. Peripheral Nerve Function and Lower Extremity Muscle Power in Older Men

    DEFF Research Database (Denmark)

    Ward, Rachel E; Caserotti, Paolo; Faulkner, Kimberly

    2014-01-01

    To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men.......To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men....

  10. Skeletal Muscle Mitochondrial Function in Polycystic Ovarian Syndrome

    DEFF Research Database (Denmark)

    Rabøl, Rasmus; Svendsen, Pernille Maj; Skovbro, Mette

    2011-01-01

    Objective Polycystic ovarian syndrome (PCOS) is associated with skeletal muscle insulin resistance, which has been linked to decreased mitochondrial function. We measured mitochondrial respiration in lean and obese women with and without PCOS using high-resolution respirometry. Methods...... Hyperinsulinemic euglycemic clamps (40 mU/min/m2) and muscle biopsies were performed on 23 women with PCOS (9 lean (body mass index (BMI) 25 kg/m2)) and 17 age- and weight-matched controls (6 lean and 11 obese). Western blotting and high-resolution respirometry was used to determine mitochondrial function. Results...... Insulin sensitivity decreased with PCOS and increasing body weight. Mitochondrial respiration with substrates for complex I and complex I+II were similar in all groups, and PCOS was not associated with a decrease in mitochondrial content as measured by mtDNA/genomicDNA. We found no correlation between...

  11. Smooth-muscle-like cells derived from human embryonic stem cells support and augment cord-like structures in vitro.

    Science.gov (United States)

    Vo, Elaine; Hanjaya-Putra, Donny; Zha, Yuanting; Kusuma, Sravanti; Gerecht, Sharon

    2010-06-01

    Engineering vascularized tissue is crucial for its successful implantation, survival, and integration with the host tissue. Vascular smooth muscle cells (v-SMCs) provide physical support to the vasculature and aid in maintaining endothelial viability. In this study, we show an efficient derivation of v-SMCs from human embryonic stem cells (hESCs), and demonstrate their functionality and ability to support the vasculature in vitro. Human ESCs were differentiated in monolayers and supplemented with platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta 1 (TGF-beta1). Human ESC-derived smooth-muscle-like cells (SMLCs) were found to highly express specific smooth muscle cell (SMC) markers--including alpha-smooth muscle actin, calponin, SM22, and smooth muscle myosin heavy chain--to produce and secrete fibronectin and collagen, and to contract in response to carbachol. In vitro tubulogenesis assays revealed that these hESC-derived SMLCs interacted with human endothelial progenitor cell (EPCs) to form longer and thicker cord-like structures in vitro. We have demonstrated a simple protocol for the efficient derivation of highly purified SMLCs from hESCs. These in vitro functional SMLCs interacted with EPCs to support and augment capillary-like structures (CLSs), demonstrating the potential of hESCs as a cell source for therapeutic vascular tissue engineering.

  12. Metabolic and transcriptional changes in cultured muscle stem cells from low birth weight subjects

    DEFF Research Database (Denmark)

    Hansen, Ninna S; Hjort, Line; Broholm, Christa

    2016-01-01

    CONTEXT/OBJECTIVE: Developmental programming of human muscle stem cells could in part explain why individuals born with low birth weight (LBW) have an increased risk of developing type 2 diabetes (T2D) later in life. We hypothesized that immature muscle stem cell functions including abnormal...... differentiation potential and metabolic function could link LBW with risk of developing T2D. Design/settings/participants: We recruited 23 young men with LBW and 16 age-matched control subjects with normal birth weight (NBW). Biopsies were obtained from vastus lateralis and muscle stem cells were isolated...... as well as decreased levels of glucose transporter-1 and -4 mRNA and of the Akt substrate of 160 kDa mRNA and protein in myotubes from LBW individuals compared with NBW individuals. The myogenic differentiation markers, myogenin and myosin heavy chain 1 and 2, were decreased during late differentiation...

  13. Physical function and muscle strength in sporadic inclusion body myositis

    DEFF Research Database (Denmark)

    Jørgensen, Anders N; Aagaard, Per; Nielsen, Jakob L

    2017-01-01

    chair stand performance were evaluated. In addition, patients were tested for knee extensor muscle strength (isokinetic dynamometer) and leg extension power (Nottingham power rig). RESULTS: TUG performance was the strongest predictor of self-reported physical function (r(2) = 0.56, P ... extension strength and between-limb strength asymmetry were the strongest multi-regression indicators of TUG performance (r(2) = 0.51, P 2) = 0.49, P

  14. Quantification of Na+,K+ pumps and their transport rate in skeletal muscle: functional significance.

    Science.gov (United States)

    Clausen, Torben

    2013-10-01

    During excitation, muscle cells gain Na(+) and lose K(+), leading to a rise in extracellular K(+) ([K(+)]o), depolarization, and loss of excitability. Recent studies support the idea that these events are important causes of muscle fatigue and that full use of the Na(+),K(+)-ATPase (also known as the Na(+),K(+) pump) is often essential for adequate clearance of extracellular K(+). As a result of their electrogenic action, Na(+),K(+) pumps also help reverse depolarization arising during excitation, hyperkalemia, and anoxia, or from cell damage resulting from exercise, rhabdomyolysis, or muscle diseases. The ability to evaluate Na(+),K(+)-pump function and the capacity of the Na(+),K(+) pumps to fill these needs require quantification of the total content of Na(+),K(+) pumps in skeletal muscle. Inhibition of Na(+),K(+)-pump activity, or a decrease in their content, reduces muscle contractility. Conversely, stimulation of the Na(+),K(+)-pump transport rate or increasing the content of Na(+),K(+) pumps enhances muscle excitability and contractility. Measurements of [(3)H]ouabain binding to skeletal muscle in vivo or in vitro have enabled the reproducible quantification of the total content of Na(+),K(+) pumps in molar units in various animal species, and in both healthy people and individuals with various diseases. In contrast, measurements of 3-O-methylfluorescein phosphatase activity associated with the Na(+),K(+)-ATPase may show inconsistent results. Measurements of Na(+) and K(+) fluxes in intact isolated muscles show that, after Na(+) loading or intense excitation, all the Na(+),K(+) pumps are functional, allowing calculation of the maximum Na(+),K(+)-pumping capacity, expressed in molar units/g muscle/min. The activity and content of Na(+),K(+) pumps are regulated by exercise, inactivity, K(+) deficiency, fasting, age, and several hormones and pharmaceuticals. Studies on the α-subunit isoforms of the Na(+),K(+)-ATPase have detected a relative increase in their

  15. Exercise-Induced Skeletal Muscle Adaptations Alter the Activity of Adipose Progenitor Cells.

    Directory of Open Access Journals (Sweden)

    Daniel Zeve

    Full Text Available Exercise decreases adiposity and improves metabolic health; however, the physiological and molecular underpinnings of these phenomena remain unknown. Here, we investigate the effect of endurance training on adipose progenitor lineage commitment. Using mice with genetically labeled adipose progenitors, we show that these cells react to exercise by decreasing their proliferation and differentiation potential. Analyses of mouse models that mimic the skeletal muscle adaptation to exercise indicate that muscle, in a non-autonomous manner, regulates adipose progenitor homeostasis, highlighting a role for muscle-derived secreted factors. These findings support a humoral link between skeletal muscle and adipose progenitors and indicate that manipulation of adipose stem cell function may help address obesity and diabetes.

  16. Nicotinamide riboside kinases display redundancy in mediating nicotinamide mononucleotide and nicotinamide riboside metabolism in skeletal muscle cells

    Directory of Open Access Journals (Sweden)

    Rachel S. Fletcher

    2017-08-01

    Conclusions: These results identify skeletal muscle cells as requiring NAMPT to maintain NAD+ availability and reveal that NRK1 and 2 display overlapping function in salvage of exogenous NR and NMN to augment intracellular NAD+ availability.

  17. [The effect of prostatic peptides on the contractile activity of smooth-muscle cells from the bladder].

    Science.gov (United States)

    Barabanova, V V; Gorbachev, A G; Parastaeva, M M; Khavinson, V Kh

    1993-02-01

    Prostatilene (PST) enhanced the functional activity of the bladder smooth-muscle cells (SMC). The possibility of activation of the SMC contractility by the PST through pharmacomechanical associations, is discussed.

  18. Rosuvastatin inhibits the smooth muscle cell proliferation by targeting TNFα mediated Rho kinase pathway

    Institute of Scientific and Technical Information of China (English)

    Xiao Sun; Hao Tong; Man Zhang; Xiao-Hang Wang

    2012-01-01

    Objective To investigate whether Tumor Necrosis Factor-alpha (TNFα) is capable of activating Rho kinase pathway which leads to smooth muscle cell proliferation and the intervention function of Rosuvastatin, and clarify the mechanism and intervention manner of anti-atherosclerosis by Rosuvastatin. Methods Wistar neonate rat smooth muscle cells were cultured, and the activity of cell proliferation was determined by methyl thiazolyl tetrazolium (MTT). The expression of Rho kinase genes after the stimulation of TNFα was evaluated by RT-PCR. Western blot method was used to measure the protein expression of proliferating cell nuclear antigen (PCNA) after TNFα stimulation and Rosuvastatin intervention in smooth muscle cell. Results The TNFα stimulation significantly enhanced the expression of Rho kinase and increased the expression of PCNA protein in smooth muscle cells (P < 0.05). These effects were positively correlated with prolonged treatment whereas additional Rosuvastatin administration inhibited the above-mentioned effects (P < 0.05). Conclusions The activation of TNFα mediated Rho kinase signaling pathway can significantly promote smooth muscle cell proliferation, and Rosuvastatin can not only inhibit this pathway but also the induced proliferation.

  19. MicroRNAs dynamically remodel gastrointestinal smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Chanjae Park

    Full Text Available Smooth muscle cells (SMCs express a unique set of microRNAs (miRNAs which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF, and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract.

  20. Effects of Kinesio Tape application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke.

    Science.gov (United States)

    Ekiz, Timur; Aslan, Meryem Doğan; Özgirgin, Neşe

    2015-01-01

    The aim of this study was to evaluate the effects of Kinesio Tape (KT) application to quadriceps muscles on isokinetic muscle strength, gait, and functional parameters in patients with stroke. Twenty-four patients were allocated into KT and control groups. All patients participated in the same conventional rehabilitation program 5 times/wk for 4 wk. In addition, KT was applied to quadriceps muscles bilaterally to the patients in the KT group. Compared with baseline, peak torque levels increased significantly in both groups (all p 0.05). KT application to quadriceps muscles in addition to conventional exercises for 4 wk is effective on isokinetic but not functional parameters.

  1. Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats

    Science.gov (United States)

    Vieira, Fabricio Furtado; Olivoto, Robson Ruiz; da Silva, Priscyla Oliveira; Francisco, Julio Cesar; Fogaça, Rosalvo Tadeu Hochmuller

    2016-01-01

    Background Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX) in the cardiac muscle. Objectives To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. Methods We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt) and relaxation (-df/dt), contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP), and contraction force induced by caffeine. Results In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05), increased +df/dt and -df/dt (p < 0.001), low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001), reduction of the maximum force in caffeine-induced contraction (p < 0.003), and decreased total contraction time (p < 0.001). The maximal contraction force did not differ significantly between groups (p = 0.973). Conclusion We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.

  2. Functional Effects of Hyperthyroidism on Cardiac Papillary Muscle in Rats

    Directory of Open Access Journals (Sweden)

    Fabricio Furtado Vieira

    Full Text Available Abstract Background: Hyperthyroidism is currently recognized to affect the cardiovascular system, leading to a series of molecular and functional changes. However, little is known about the functional influence of hyperthyroidism in the regulation of cytoplasmic calcium and on the sodium/calcium exchanger (NCX in the cardiac muscle. Objectives: To evaluate the functional changes in papillary muscles isolated from animals with induced hyperthyroidism. Methods: We divided 36 Wistar rats into a group of controls and another of animals with hyperthyroidism induced by intraperitoneal T3 injection. We measured in the animals' papillary muscles the maximum contraction force, speed of contraction (+df/dt and relaxation (-df/dt, contraction and relaxation time, contraction force at different concentrations of extracellular sodium, post-rest potentiation (PRP, and contraction force induced by caffeine. Results: In hyperthyroid animals, we observed decreased PRP at all rest times (p < 0.05, increased +df/dt and -df/dt (p < 0.001, low positive inotropic response to decreased concentration of extracellular sodium (p < 0.001, reduction of the maximum force in caffeine-induced contraction (p < 0.003, and decreased total contraction time (p < 0.001. The maximal contraction force did not differ significantly between groups (p = 0.973. Conclusion: We hypothesize that the changes observed are likely due to a decrease in calcium content in the sarcoplasmic reticulum, caused by calcium leakage, decreased expression of NCX, and increased expression of a-MHC and SERCA2.

  3. 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.

  4. 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.

  5. Structural, biochemical, cellular, and functional changes in skeletal muscle extracellular matrix with aging

    DEFF Research Database (Denmark)

    Kragstrup, Tue Wenzel; Kjaer, M; Mackey, A L

    2011-01-01

    The extracellular matrix (ECM) of skeletal muscle is critical for force transmission and for the passive elastic response of skeletal muscle. Structural, biochemical, cellular, and functional changes in skeletal muscle ECM contribute to the deterioration in muscle mechanical properties with aging...

  6. Skeletal muscle power: a critical determinant of physical functioning in older adults

    Science.gov (United States)

    Muscle power declines earlier and more precipitously with advancing age compared to muscle strength. Peak muscle power has also emerged as an important predictor of functional limitations in older adults. Our current working hypothesis is focused on examining lower extremity muscle power as a more d...

  7. Immunological studies on the structure and function of the nicotinic acetylcholine receptor in mammalian muscle

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Y.

    1989-01-01

    The specificity of the antibodies in the serum of a patient with myasthenia gravis for a the {alpha}-bungarotoxin binding sites of the acetylcholine receptor (AChR) was examined using AChRs in the C2 mouse muscle cell line as a model. The antibodies were shown to be specific for one of the two toxin-binding sites. The effect of the antibodies in this myasthenic serum on the functional response of the receptor to cholinergic agonists was also examined using carbamylcholine-induced {sup 22}Na uptake into C2 myotubes as a measured of the receptor function. Antibodies specific for the {gamma}, {delta}, and {epsilon} subunit, respectively, of mammalian muscle AChRs were developed using subunit-specific synthetic peptides as antigens. Using these antibodies and monoclonal antibodies for other subunits as probes, I have identified four ({alpha}, {beta}, {gamma}, and {delta}) subunits of mammalian muscle AChRs on immunoblots. When AChRs from embryonic, neonatal, normal and denervated adult muscles were compared on immunoblots, the {alpha}, {beta}, and {delta} subunits were identical in all four receptor preparations, with or without endoglycosidase digestion. The spatial and temporal distribution of the {gamma}- and {epsilon}- AChRs in developing and in denervated muscles corresponds to the distribution of AChRs with slow and fast channels, respectively, and that the development changes in the channel properties of the receptor arise from a change in the subunit composition of the receptor, in which the {gamma} is replaced by {epsilon}.

  8. Injectable skeletal muscle matrix hydrogel promotes neovascularization and muscle cell infiltration in a hindlimb ischemia model

    Directory of Open Access Journals (Sweden)

    JA DeQuach

    2012-06-01

    Full Text Available Peripheral artery disease (PAD currently affects approximately 27 million patients in Europe and North America, and if untreated, may progress to the stage of critical limb ischemia (CLI, which has implications for amputation and potential mortality. Unfortunately, few therapies exist for treating the ischemic skeletal muscle in these conditions. Biomaterials have been used to increase cell transplant survival as well as deliver growth factors to treat limb ischemia; however, existing materials do not mimic the native skeletal muscle microenvironment they are intended to treat. Furthermore, no therapies involving biomaterials alone have been examined. The goal of this study was to develop a clinically relevant injectable hydrogel derived from decellularized skeletal muscle extracellular matrix and examine its potential for treating PAD as a stand-alone therapy by studying the material in a rat hindlimb ischemia model. We tested the mitogenic activity of the scaffold’s degradation products using an in vitro assay and measured increased proliferation rates of smooth muscle cells and skeletal myoblasts compared to collagen. In a rat hindlimb ischemia model, the femoral artery was ligated and resected, followed by injection of 150 µL of skeletal muscle matrix or collagen 1 week post-injury. We demonstrate that the skeletal muscle matrix increased arteriole and capillary density, as well as recruited more desmin-positive and MyoD-positive cells compared to collagen. Our results indicate that this tissue-specific injectable hydrogel may be a potential therapy for treating ischemia related to PAD, as well as have potential beneficial effects on restoring muscle mass that is typically lost in CLI.

  9. Therapies for sarcopenia and regeneration of old skeletal muscles: more a case of old tissue architecture than old stem cells.

    Science.gov (United States)

    Grounds, Miranda D

    2014-01-01

    Age related loss of skeletal muscle mass and function (sarcopenia) reduces independence and the quality of life for individuals, and leads to falls and fractures with escalating health costs for the rapidly aging human population. Thus there is much interest in developing interventions to reduce sarcopenia. One area that has attracted recent attention is the proposed use of myogenic stem cells to improve regeneration of old muscles. This mini-review challenges the fundamental need for myogenic stem cell therapy for sarcopenia. It presents evidence that demonstrates the excellent capacity of myogenic stem cells from very old rodent and human muscles to form new muscles after experimental myofiber necrosis. The many factors required for successful muscle regeneration are considered with a strong focus on integration of components of old muscle bioarchitecture. The fundamental role of satellite cells in homeostasis of normal aging muscles and the incidence of endogenous regeneration in old muscles is questioned. These issues, combined with problems for clinical myogenic stem cell therapies for severe muscle diseases, raise fundamental concerns about the justification for myogenic stem cell therapy for sarcopenia.

  10. MicroRNA-128 regulates the proliferation and differentiation of bovine skeletal muscle satellite cells by repressing Sp1.

    Science.gov (United States)

    Dai, Yang; Zhang, Wei Ran; Wang, Yi Min; Liu, Xin Feng; Li, Xin; Ding, Xiang Bin; Guo, Hong

    2016-03-01

    MicroRNAs (miRNAs) play essential roles in muscle cell proliferation and differentiation. The muscle-specific miRNAs miR-1 and miR-206 have been shown to regulate muscle development and promote myogenic differentiation; however, it is likely that a number of other miRNAs play important roles in regulating myogenesis as well. microRNA-128 (miR-128) has been reported to be highly expressed in brain and skeletal muscle, and we found that miR-128 is also up-regulated during bovine skeletal muscle satellite cell differentiation using microarray analysis and qRT-PCR. However, little is known about the functions of miR-128 in bovine skeletal muscle satellite cell development. In this study, we investigated the biological functions of miR-128 in bovine skeletal muscle cell development. Using a dual-luciferase reporter assay, we confirmed that miR-128 regulates the Sp1 gene. Over-expression of miR-128 reduced Sp1 protein levels and inhibited muscle satellite cell proliferation and differentiation. Inhibition of miR-128 increased Sp1 protein levels and promoted muscle satellite cell differentiation but also suppressed proliferation. Changes in miR-128 and Sp1 expression levels also affected the protein levels of MyoD and CDKN1A. Sp1, an activator of MyoD and a suppressor of CDKN1A, plays an important role in bovine muscle cell proliferation and differentiation. The results of our study reveal a mechanism by which miR-128 regulates bovine skeletal muscle satellite cell proliferation and myogenic differentiation via Sp1.

  11. Ureter smooth muscle cell orientation in rat is predominantly longitudinal.

    Directory of Open Access Journals (Sweden)

    Bart Spronck

    Full Text Available In ureter peristalsis, the orientation of the contracting smooth muscle cells is essential, yet current descriptions of orientation and composition of the smooth muscle layer in human as well as in rat ureter are inconsistent. The present study aims to improve quantification of smooth muscle orientation in rat ureters as a basis for mechanistic understanding of peristalsis. A crucial step in our approach is to use two-photon laser scanning microscopy and image analysis providing objective, quantitative data on smooth muscle cell orientation in intact ureters, avoiding the usual sectioning artifacts. In 36 rat ureter segments, originating from a proximal, middle or distal site and from a left or right ureter, we found close to the adventitia a well-defined longitudinal smooth muscle orientation. Towards the lamina propria, the orientation gradually became slightly more disperse, yet the main orientation remained longitudinal. We conclude that smooth muscle cell orientation in rat ureter is predominantly longitudinal, though the orientation gradually becomes more disperse towards the proprial side. These findings do not support identification of separate layers. The observed longitudinal orientation suggests that smooth muscle contraction would rather cause local shortening of the ureter, than cause luminal constriction. However, the net-like connective tissue of the ureter wall may translate local longitudinal shortening into co-local luminal constriction, facilitating peristalsis. Our quantitative, minimally invasive approach is a crucial step towards more mechanistic insight into ureter peristalsis, and may also be used to study smooth muscle cell orientation in other tube-like structures like gut and blood vessels.

  12. Menthol inhibiting parasympathetic function of tracheal smooth muscle

    Science.gov (United States)

    Wang, Hsing-Won; Liu, Shao-Cheng; Chao, Pin-Zhir; Lee, Fei-Peng

    2016-01-01

    Menthol is used as a constituent of food and drink, tobacco and cosmetics nowadays. This cold receptor agonist has been used as a nasal inhalation solution in the daily life. The effect of menthol on nasal mucosa in vivo is well known; however, the effect of the drug on tracheal smooth muscle has been rarely explored. Therefore, during administration of the drug for nasal symptoms, it might also affect the trachea via oral intake or inhalation. We used our preparation to test the effectiveness of menthol on isolated rat tracheal smooth muscle. A 5 mm long portion of rat trachea was submersed in 30 ml Krebs solution in a muscle bath at 37ºC. Changes in tracheal contractility in response to the application of a parasympathetic mimetic agent were measured using a transducer connected to a Pentium III computer equipped with polygraph software. The following assessments of menthol were performed: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10-6 M methacholine as a parasympathetic mimetic; (3) effect of the drug on electrically induced tracheal smooth muscle contractions. Results indicated that addition of a parasympathetic mimetic to the incubation medium caused the trachea to contract in a dose-dependent manner. Addition of menthol at doses of 10-5 M or above elicited a relaxation response to 10-6 M methacholine-induced contraction. Menthol could also inhibit electrical field stimulation (EFS) induced spike contraction. However, it alone had a minimal effect on the basal tension of trachea as the concentration increased. We concluded that the degree of drug-induced tracheal contraction or relaxation was dose-dependent. In addition, this study indicated that high concentrations of menthol might actually inhibit parasympathetic function of the trachea. PMID:27994497

  13. Functional changes of human quadriceps muscle injured by eccentric exercise

    Directory of Open Access Journals (Sweden)

    F.V. Serrão

    2003-06-01

    Full Text Available The present study evaluated functional changes of quadriceps muscle after injury induced by eccentric exercise. Maximal isometric torque of quadriceps and the surface electromyography (root mean square, RMS, and median frequency, MDF of the vastus medialis oblique (VMO and vastus lateralis (VL muscles were examined before, immediately after and during the first 7 days after injury. Serum creatine kinase (CK levels and magnetic resonance imaging (MRI were used to identify muscle injury. The subject was used as her own control and percent refers to pre-injury data. Experiments were carried out with a sedentary 23-year-old female. Injury was induced by 4 bouts of 15 maximal isokinetic eccentric contractions (angular velocity of 5º/s; range of motion from 40º to 110º of knee flexion. The isometric torque of the quadriceps (knee at 90º flexion decreased 52% immediately after eccentric exercise and recovered on the 5th day. The highest reduction of RMS occurred on the 2nd day after injury in both VL (63% and VMO (66% and only VL recovered to the pre-injury level on the 7th day. Immediately after injury, the MDF decreased by 5 and 3% (VMO and VL, respectively and recovered one day later. Serum CK levels increased by 109% on the 2nd day and were still increased by 32% on the 7th day. MRI showed large areas of injury especially in the deep region of quadriceps. In conclusion, eccentric exercise decreased the isometric torque and electromyographic signals of quadriceps muscle, which were recovered in one week, despite the muscle regeneration signals.

  14. Leucocytes, cytokines and satellite cells: what role do they play in muscle damage and regeneration following eccentric exercise?

    Science.gov (United States)

    Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls; Peake, Jonathan M

    2012-01-01

    Exercise-induced muscle damage is an important topic in exercise physiology. However several aspects of our understanding of how muscles respond to highly stressful exercise remain unclear In the first section of this review we address the evidence that exercise can cause muscle damage and inflammation in otherwise healthy human skeletal muscles. We approach this concept by comparing changes in muscle function (i.e., the force-generating capacity) with the degree of leucocyte accumulation in muscle following exercise. In the second section, we explore the cytokine response to 'muscle-damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role of the cyclooxygenase enzymes (COX1 and 2). In summary, we propose that muscle damage as evaluated by changes in muscle function is related to leucocyte accumulation in the exercised muscles. 'Extreme' exercise protocols, encompassing unaccustomed maximal eccentric exercise across a large range of motion, generally inflict severe muscle damage, inflammation and prolonged recovery (> 1 week). By contrast, exercise resembling regular athletic training (resistance exercise and downhill running) typically causes mild muscle damage (myofibrillar disruptions) and full recovery normally occurs within a few days. Large variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to

  15. Exercise-induced stem cell activation and its implication for cardiovascular and skeletal muscle regeneration.

    Science.gov (United States)

    Wahl, Patrick; Brixius, Klara; Bloch, Wilhelm

    2008-01-01

    A number of publications have provided evidence that exercise and physical activity are linked to the activation, mobilization, and differentiation of various types of stem cells. Exercise may improve organ regeneration and function. This review summarizes mechanisms by which exercise contributes to stem cell-induced regeneration in the cardiovascular and the skeletal muscle system. In addition, it discusses whether exercise may improve and support stem cell transplantation in situations of cardiovascular disease or muscular dystrophy.

  16. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, M.; Goodpaster, B.H.; Kritchevsky, S.B.; Newman, A.B.; Nevitt, M.C.; Rubin, S.M.; Simonsick, E.M.; Harris, T.B.

    2005-01-01

    .05). Among men and women, associations were similar for blacks and whites. CONCLUSION: Lower muscle mass (smaller cross-sectional thigh muscle area), greater fat infiltration into the muscle, and lower knee extensor muscle strength are associated with increased risk of mobility loss in older men

  17. Muscle mass, muscle strength, and muscle fat infiltration as predictors of incident mobility limitations in well-functioning older persons

    NARCIS (Netherlands)

    Visser, M.; Goodpaster, B.H.; Kritchevsky, S.B.; Newman, A.B.; Nevitt, M.C.; Rubin, S.M.; Simonsick, E.M.; Harris, T.B.

    2005-01-01

    .05). Among men and women, associations were similar for blacks and whites. CONCLUSION: Lower muscle mass (smaller cross-sectional thigh muscle area), greater fat infiltration into the muscle, and lower knee extensor muscle strength are associated with increased risk of mobility loss in older men an

  18. Discrepancies between Skinned Single Muscle Fibres and Whole Thigh Muscle Function Characteristics in Young and Elderly Human Subjects

    Directory of Open Access Journals (Sweden)

    Hyunseok Jee

    2016-01-01

    Full Text Available We aimed to analyse the mechanical properties of skinned single muscle fibres derived from the vastus lateralis (VL muscle in relation to those of the whole intact thigh muscle and to compare any difference between young and older adults. Sixteen young men (29.25±4.65 years, 11 older men (71.45±2.94 years, 11 young women (29.64±4.88 years, and 7 older women (67.29±1.70 years were recruited. In vivo analyses were performed for mechanical properties such as isokinetic performance, isometric torque, and power. Specific force and maximum shortening velocity (Vo were measured with single muscle fibres. Sex difference showed greater impact on the functional properties of both the whole muscle (p<0.01 and single muscle fibres than aging (p<0.05. Sex difference, rather than aging, yielded more remarkable differences in gross mechanical properties in the single muscle fibre study in which significant differences between young men and young women were found only in the cross-sectional area and Vo (p<0.05. Age and sex differences reflect the mechanical properties of both single muscle fibres and whole thigh muscle, with the whole muscle yielding more prominent functional properties.

  19. EXPERIMENTAL STUDY ON INFLUENCE OF MUSCLE TENSION TOWARDS THE FUNCTION OF THE SKELETAL MUSCLE FOLLOWING ITS REINNERVATION

    Institute of Scientific and Technical Information of China (English)

    Pramod DEVKOTA; ZENG Bing-fang(曾炳芳); FAN Cun-yi(范存义); TANG Jian-fei(唐剑飞); SHUI Shu-ping(眭述平); JIANG Pei-zhu(姜佩珠)

    2004-01-01

    Objective To investigate the influence of tension on the function of the denervated skeletal muscle after its reinnervation. Methods Fifty-four Sprague-Dawley (SD) rats were randomly divided into 3 groups. The left gastrocnemius muscles of the rats were dissected with only the neurovascular pedicles intact; the tibial nerves were cut and immediately repaired by epineurial suture. Then the Achilles tendons were isolated and treated accordingly; the Achilles tendon was lengthened by 0. 5cra in lengthened group, shortened by 0. 5cra in shortened group and left alone in normal (control) group. In the 2nd, 4th and 8th week after operation, the isometric twitch contractile force of both the right and the left gastrocnemius muscles were measured; specimens were taken from gastrocnemius muscle for histological study by light microscope. Results In comparison between the groups, the gastrocnemius muscles in the shortened group showed less severe muscle atrophy and connective tissue proliferation,bigger diameter and cross section dimension of the muscle fiber and greater isometric twitch contractile strength of the bilateral gastrocnemius muscles than those in the normal and lengthened groups in all the postoperative periods.Conclusion A proper high tension of the muscle may improve the function of the denervated skeletal muscle after its reinnervation.

  20. Papillary muscle approximation to septum for functional tricuspid regurgitation.

    Science.gov (United States)

    Lohchab, Shamsher Singh; Chahal, Ashok Kumar; Agrawal, Nilesh

    2015-07-01

    Current techniques for repair of functional tricuspid regurgitation are associated with a significant degree of residual or recurrent regurgitation. We describe a technique of anterior papillary muscle attachment to the septum to correct residual tricuspid regurgitation persisting after annuloplasty. In our early experience in 15 patients (6 men and 9 women) with a mean age of 32 ± 11 years, who underwent annuloplasty for severe functional tricuspid regurgitation secondary to rheumatic mitral valve disease, this technique effectively eliminated residual tricuspid regurgitation.

  1. Functional and cellular adaptations of rodent skeletal muscle to weightlessness

    Science.gov (United States)

    Caiozzo, Vincent J.; Haddad, Fadia; Baker, Michael J.; Baldwin, Kenneth M.

    1995-01-01

    This paper describes the affects of microgravity upon three key cellular levels (functional, protein, and mRNA) that are linked to one another. It is clear that at each of these levels, microgravity produces rapid and substantial alterations. One of the key challenges facing the life science community is the development of effective countermeasures that prevent the loss of muscle function as described in this paper. The development of optimal countermeasures, however, awaits a clearer understanding of events occurring at the levels of transcription, translation, and degradation.

  2. Muscle Atrophy Reversed by Growth Factor Activation of Satellite Cells in a Mouse Muscle Atrophy Model

    DEFF Research Database (Denmark)

    Hauerslev, Simon; Vissing, John; Krag, Thomas O

    2014-01-01

    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...

  3. Stromal vascular stem cell treatment decreases muscle fibrosis following chronic rotator cuff tear.

    Science.gov (United States)

    Gumucio, Jonathan P; Flood, Michael D; Roche, Stuart M; Sugg, Kristoffer B; Momoh, Adeyiza O; Kosnik, Paul E; Bedi, Asheesh; Mendias, Christopher L

    2016-04-01

    Rotator cuff injuries are associated with atrophy and fat infiltration into the muscle, commonly referred to as "fatty degeneration." As the poor function of chronically torn muscles may limit recovery after surgical repair, there is considerable interest in finding therapies to enhance muscle regeneration. Stromal vascular fraction stem cells (SVFCs) can improve muscle regeneration in other chronic injury states, and our objective was to evaluate the ability of SVFCs to reduce fibrosis and fat accumulation, and enhance muscle fibre specific force production after chronic rotator cuff tear. Chronic supraspinatus tears were induced in adult immunodeficient rats, and repaired one month following tear. Rats received vehicle control, or injections of 3 × 10(5) or 3 × 10(6) human SVFCs into supraspinatus muscles. Two weeks following repair, we detected donor human DNA and protein in SVFC treated muscles. There was a 40 % reduction in fibrosis in the treated groups compared to controls (p = 0.03 for 3 × 10(5), p = 0.04 for 3 × 10(6)), and no differences between groups for lipid content or force production were observed. As there has been much interest in the use of stem cell-based therapies in musculoskeletal regenerative medicine, the reduction in fibrosis and trend towards an improvement in single fiber contractility suggest that SVFCs may be beneficial to enhance the treatment and recovery of patients with chronic rotator cuff tears.

  4. Muscle function in rheumatic disease patients treated with corticosteroids.

    Science.gov (United States)

    Rothstein, J M; Delitto, A; Sinacore, D R; Rose, S J

    1983-02-01

    Clinical and experimental data indicate that long-term corticosteroid use leads to atrophy of the type 2 muscle fibers. The purpose of this study was to characterize and quantify the nature of muscle function in rheumatic disease patients who have been on long-term corticosteroid therapy. Quadriceps function (i.e., peak torque and power) in 19 patients (11 with rheumatoid arthritis, five with systemic lupus erythematosis, and 3 other) and 11 age- and activity-matched normal controls was measured with an isokinetic dynamometer (Cybex II), during four constant velocity movements. Power was significantly lower for the patients at all speeds. At the higher speeds the patients' deficit in power production increased as indicated by a difference in the slopes of power-velocity regression lines. Measures of peak torque could not be consistently used to differentiate the groups. Patients with rheumatic diseases receiving corticosteroids have a decreased ability to generate muscle power. The method described allows for quantification of these deficits in a clinical setting.

  5. 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(S): Cond......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......(S): Conditioned media (CM) were collected from human skeletal muscle (HSkM) cells treated with or without electrical pulse stimulation (EPS). Antecubital and femoral venous blood serum were collected before and after an exercise bout. CM and sera with or without IL-6 neutralization were used to incubate insulin...... and exercise increased circulating IL-6 levels in antecubital and femoral serum. IL-6 neutralization demonstrated that muscle-derived IL-6 prevents INS-1 and islet apoptosis in the absence of IL-1β+IFN-γ, but augments apoptosis under proinflammatory conditions, and that muscle-derived IL-6 supports islet...

  6. Dystrophin expression in muscle stem cells regulates their polarity and asymmetric division.

    Science.gov (United States)

    Dumont, Nicolas A; Wang, Yu Xin; von Maltzahn, Julia; Pasut, Alessandra; Bentzinger, C Florian; Brun, Caroline E; Rudnicki, Michael A

    2015-12-01

    Dystrophin is expressed in differentiated myofibers, in which it is required for sarcolemmal integrity, and loss-of-function mutations in the gene that encodes it result in Duchenne muscular dystrophy (DMD), a disease characterized by progressive and severe skeletal muscle degeneration. Here we found that dystrophin is also highly expressed in activated muscle stem cells (also known as satellite cells), in which it associates with the serine-threonine kinase Mark2 (also known as Par1b), an important regulator of cell polarity. In the absence of dystrophin, expression of Mark2 protein is downregulated, resulting in the inability to localize the cell polarity regulator Pard3 to the opposite side of the cell. Consequently, the number of asymmetric divisions is strikingly reduced in dystrophin-deficient satellite cells, which also display a loss of polarity, abnormal division patterns (including centrosome amplification), impaired mitotic spindle orientation and prolonged cell divisions. Altogether, these intrinsic defects strongly reduce the generation of myogenic progenitors that are needed for proper muscle regeneration. Therefore, we conclude that dystrophin has an essential role in the regulation of satellite cell polarity and asymmetric division. Our findings indicate that muscle wasting in DMD not only is caused by myofiber fragility, but also is exacerbated by impaired regeneration owing to intrinsic satellite cell dysfunction.

  7. Resistance training, insulin sensitivity and muscle function in the elderly

    DEFF Research Database (Denmark)

    Dela, Flemming; Kjaer, Michael

    2006-01-01

    are associated with an age-related decrease in the physical activity level and can be counteracted by increased physical activity of a resistive nature. Strength training has been shown to improve insulin-stimulated glucose uptake in both healthy elderly individuals and patients with manifest diabetes......, and likewise to improve muscle strength in both elderly healthy individuals and in elderly individuals with chronic disease. The increased strength is coupled to improved function and a decreased risk for fall injuries and fractures. Elderly individuals have preserved the capacity to improve muscle strength...... and mass with training, but seem to display a reduced sensitivity towards stimulating protein synthesis from nutritional intake, rather than by any reduced response in protein turnover to exercise....

  8. Transoesophageal ultrasound and computer tomographic assessment of the equine cricoarytenoid dorsalis muscle: Relationship between muscle geometry and exercising laryngeal function.

    Science.gov (United States)

    Kenny, M; Cercone, M; Rawlinson, J J; Ducharme, N G; Bookbinder, L; Thompson, M; Cheetham, J

    2017-05-01

    Early detection of recurrent laryngeal neuropathy (RLN) is of considerable interest to the equine industry. To describe two imaging modalities, transoesophageal ultrasound (TEU) and computed tomography (CT) with multiplanar reconstruction to assess laryngeal muscle geometry, and determine the relationship between cricoarytenoid dorsalis (CAD) geometry and function. Two-phase study evaluating CAD geometry in experimental horses and horses with naturally occurring RLN. Equine CAD muscle volume was determined from CT scan sets using volumetric reconstruction with LiveWire. The midbody and caudal dorsal-ventral thickness of the CAD muscle was determined using a TEU in the same horses; and in horses with a range of severity of RLN (n = 112). Transoesophageal ultrasound was able to readily image the CAD muscles and lower left:right CAD thickness ratios were observed with increasing disease severity. Computed tomography based muscle volume correlated very closely with ex vivo muscle volume (R(2) = 0.77). Computed tomography reconstruction can accurately determine intrinsic laryngeal muscle geometry. A relationship between TEU measurements of CAD geometry and laryngeal function was established. These imaging techniques could be used to track the response of the CAD muscle to restorative surgical treatments such as nerve muscle pedicle graft, nerve anastomosis and functional electrical stimulation. © 2016 EVJ Ltd.

  9. Contractile proteins of endothelial cells, platelets and smooth muscle.

    Science.gov (United States)

    Becker, C G; Nachman, R L

    1973-04-01

    In experiments described herein it was observed, by direct and indirect immunofluorescence technics, that rabbit antisera to human platelet actomyosin (thrombosthenin) stained mature megakaryocytes, blood platelets, endothelial cells and smooth muscle cells of arteries and veins, endothelial cells of liver sinusoids and certain capillaries, uterine smooth muscle cells, myoepithelial cells, perineurial cells of peripheral nerves and "fibroblastic" cells of granulation tissue. The specificity of immunohistologic staining was confirmed by appropriate absorption and blocking studies and immunodiffusional analysis in agarose gel. It was also observed by immunodiffusional analysis in agarose gel, electrophoresis of actomyosin fragments in polyacrylamide gels, immune inhibition of actomyosin ATPase activity and immune aggregation of platelets that uterine and platelet actomyosin are partially, but not completely, identical.

  10. RBP-J (Rbpsuh) is essential to maintain muscle progenitor cells and to generate satellite cells.

    Science.gov (United States)

    Vasyutina, Elena; Lenhard, Diana C; Wende, Hagen; Erdmann, Bettina; Epstein, Jonathan A; Birchmeier, Carmen

    2007-03-13

    In the developing muscle, a pool of myogenic progenitor cells is formed and maintained. These resident progenitors provide a source of cells for muscle growth in development and generate satellite cells in the perinatal period. By the use of conditional mutagenesis in mice, we demonstrate here that the major mediator of Notch signaling, the transcription factor RBP-J, is essential to maintain this pool of progenitor cells in an undifferentiated state. In the absence of RBP-J, these cells undergo uncontrolled myogenic differentiation, leading to a depletion of the progenitor pool. This results in a lack of muscle growth in development and severe muscle hypotrophy. In addition, satellite cells are not formed late in fetal development in conditional RBP-J mutant mice. We conclude that RBP-J is required in the developing muscle to set aside proliferating progenitors and satellite cells.

  11. Channels Active in the Excitability of Nerves and Skeletal Muscles across the Neuromuscular Junction: Basic Function and Pathophysiology

    Science.gov (United States)

    Goodman, Barbara E.

    2008-01-01

    Ion channels are essential for the basic physiological function of excitable cells such as nerve, skeletal, cardiac, and smooth muscle cells. Mutations in genes that encode ion channels have been identified to cause various diseases and disorders known as channelopathies. An understanding of how individual ion channels are involved in the…

  12. Channels Active in the Excitability of Nerves and Skeletal Muscles across the Neuromuscular Junction: Basic Function and Pathophysiology

    Science.gov (United States)

    Goodman, Barbara E.

    2008-01-01

    Ion channels are essential for the basic physiological function of excitable cells such as nerve, skeletal, cardiac, and smooth muscle cells. Mutations in genes that encode ion channels have been identified to cause various diseases and disorders known as channelopathies. An understanding of how individual ion channels are involved in the…

  13. Tear function and ocular surface after Muller muscle-conjunctival resection.

    Science.gov (United States)

    Uğurbaş, Suat Hayri; Alpay, Atilla; Bahadır, Burak; Uğurbaş, Sılay Cantürk

    2014-05-01

    Muller muscle-conjunctival resection (MCR) is a surgical technique to correct mild and moderate ptosis. In this study, tear function tests and ocular surface are evaluated in patients who underwent unilateral surgery. Sixteen patients with normal preoperative tear function who underwent unilateral MCR were evaluated prospectively. The fellow eyes of the patients were taken as the control group. A dry eye assessment questionnaire, Schirmer testing, tear film break-up time, fluorescein stain, Rose-Bengal stain, and conjunctival impression cytology were used to assess the tear film functions and ocular surface changes in the operated and non-operated eyes. There was no statistically significant difference in the tear function tests and goblet cell densities between the operated and non-operated eyes. The results indicate that an MCR procedure has no apparent effect on tear function tests and goblet cell density in patients with normal preoperative tear function.

  14. Repositioning forelimb superficialis muscles: tendon attachment and muscle activity enable active relocation of functional myofibers.

    Science.gov (United States)

    Huang, Alice H; Riordan, Timothy J; Wang, Lingyan; Eyal, Shai; Zelzer, Elazar; Brigande, John V; Schweitzer, Ronen

    2013-09-16

    The muscles that govern hand motion are composed of extrinsic muscles that reside within the forearm and intrinsic muscles that reside within the hand. We find that the extrinsic muscles of the flexor digitorum superficialis (FDS) first differentiate as intrinsic muscles within the hand and then relocate as myofibers to their final position in the arm. This remarkable translocation of differentiated myofibers across a joint is dependent on muscle contraction and muscle-tendon attachment. Interestingly, the intrinsic flexor digitorum brevis (FDB) muscles of the foot are identical to the FDS in tendon pattern and delayed developmental timing but undergo limited muscle translocation, providing strong support for evolutionary homology between the FDS and FDB muscles. We propose that the intrinsic FDB pattern represents the original tetrapod limb and that translocation of the muscles to form the FDS is a mammalian evolutionary addition.

  15. Smooth muscle α actin (Acta2 and myofibroblast function during hepatic wound healing.

    Directory of Open Access Journals (Sweden)

    Don C Rockey

    Full Text Available Smooth muscle α actin (Acta2 expression is largely restricted to smooth muscle cells, pericytes and specialized fibroblasts, known as myofibroblasts. Liver injury, associated with cirrhosis, induces transformation of resident hepatic stellate cells into liver specific myofibroblasts, also known as activated cells. Here, we have used in vitro and in vivo wound healing models to explore the functional role of Acta2 in this transformation. Acta2 was abundant in activated cells isolated from injured livers but was undetectable in quiescent cells isolated from normal livers. Both cellular motility and contraction were dramatically increased in injured liver cells, paralleled by an increase in Acta2 expression, when compared with quiescent cells. Inhibition of Acta2 using several different techniques had no effect on cytoplasmic actin isoform expression, but led to reduced cellular motility and contraction. Additionally, Acta2 knockdown was associated with a significant reduction in Erk1/2 phosphorylation compared to control cells. The data indicate that Acta2 is important specifically in myofibroblast cell motility and contraction and raise the possibility that the Acta2 cytoskeleton, beyond its structural importance in the cell, could be important in regulating signaling processes during wound healing in vivo.

  16. Effects of Dexamethasone on Satellite Cells and Tissue Engineered Skeletal Muscle Units.

    Science.gov (United States)

    Syverud, Brian C; VanDusen, Keith W; Larkin, Lisa M

    2016-03-01

    Tissue engineered skeletal muscle has potential for application as a graft source for repairing soft tissue injuries, a model for testing pharmaceuticals, and a biomechanical actuator system for soft robots. However, engineered muscle to date has not produced forces comparable to native muscle, limiting its potential for repair and for use as an in vitro model for pharmaceutical testing. In this study, we examined the trophic effects of dexamethasone (DEX), a glucocorticoid that stimulates myoblast differentiation and fusion into myotubes, on our tissue engineered three-dimensional skeletal muscle units (SMUs). Using our established SMU fabrication protocol, muscle isolates were cultured with three experimental DEX concentrations (5, 10, and 25 nM) and compared to untreated controls. Following seeding onto a laminin-coated Sylgard substrate, the administration of DEX was initiated on day 0 or day 6 in growth medium or on day 9 after the switch to differentiation medium and was sustained until the completion of SMU fabrication. During this process, total cell proliferation was measured with a BrdU assay, and myogenesis and structural advancement of muscle cells were observed through immunostaining for MyoD, myogenin, desmin, and α-actinin. After SMU formation, isometric tetanic force production was measured to quantify function. The histological and functional assessment of the SMU showed that the administration of 10 nM DEX beginning on either day 0 or day 6 yielded optimal SMUs. These optimized SMUs exhibited formation of advanced sarcomeric structure and significant increases in myotube diameter and myotube fusion index, compared with untreated controls. Additionally, the optimized SMUs matured functionally, as indicated by a fivefold rise in force production. In conclusion, we have demonstrated that the addition of DEX to our process of engineering skeletal muscle tissue improves myogenesis, advances muscle structure, and increases force production in the

  17. 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.

  18. Dystrophic tendon functionality is recovered by muscle-specific expression of insulin-like growth factor in mdx mice.

    Science.gov (United States)

    Rizzuto, E; Catizone, A; Musarò, A; Del Prete, Z

    2013-02-01

    Duchenne muscular dystrophy (DMD) is a severe genetic disorder of skeletal muscle, characterized by a steady muscle weakness. By using the animal model for DMD, the mdx mice, we have previously demonstrated that biomechanical properties of tendinous tissue are also significantly affected in this muscle pathology. Muscle specific over-expression of insulin like growth factor-1 (mIgf-1) is known to induce a partial recovery in muscle functionality, in particular increasing the muscle absolute force, but not the specific force. To test whether Igf-1 muscle specific over-expression helps the recovery also in tendinous tissue, mechanical and cellular evaluation of mdx and mdx:MLC/mIgf-1 mice tendons has been performed. Mechanical properties were investigated by measuring the viscoelastic response of the tissue, while cell viability was evaluated by molecular assays. An absolute recovery in the mechanical properties of EDL and TA tendons was observed through the measurement of tissue viscoelasticity for several different frequencies of interest. Moreover, when compared with tendons from dystrophic mdx animals, mdx:MLC/mIgf-1 specimens showed an almost complete recovery in the number of viable cells for both extensor digitorum longus (EDL) and tibialis anterior (TA) tendons. Of note, the partial recovery in muscle functionality and the full recovery in tendons response, suggests that mIgf-1 muscle specific over-expression exerts its effect on tendons either indirectly, improving the tendon viability and its functional properties as a consequence of the reduction of the hostile muscle dystrophic environment, or acting directly on the tendon tissue, as a paracrine trophic factor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Strenuous resistance exercise effects on magnetic resonance diffusion parameters and muscle-tendon function in human skeletal muscle.

    Science.gov (United States)

    Yanagisawa, Osamu; Kurihara, Toshiyuki; Kobayashi, Naoyuki; Fukubayashi, Toru

    2011-10-01

    To assess the effects of strenuous exercise on magnetic resonance diffusion parameters and muscle-tendon complex function in skeletal muscle. Six men performed ankle plantar flexion exercises with eccentric contraction. The fractional anisotropy (FA), λ(1) , λ(2) , λ(3) , mean diffusivity (MD), and T(2) values in the triceps surae muscles were measured by magnetic resonance diffusion tensor and spin-echo imaging. Passive torque of plantar flexors, maximal voluntary isometric plantar flexion torques (MVIP), and Achilles tendon stiffness during MVIP were measured by combined ultrasonography and dynamometry. Plasma creatine kinase and muscle soreness were also assessed. These parameters were measured before and 1-8 days postexercise. The medial gastrocnemius exhibited significantly decreased FA 2-5 days after, increased λ(2) 3 days after, and increased λ(3) 2 and 3 days after exercise. This muscle also showed significantly increased MD and T(2) values 3 days postexercise. MVIP significantly decreased 2 and 3 days postexercise, while passive torque significantly increased 2 days postexercise. Creatine kinase and muscle soreness increased 3-5 days and 1-5 days postexercise, respectively. Exercise-induced muscle damage manifested as significant changes in muscle diffusion parameters with muscle-tendon complex dysfunction and delayed-onset muscle soreness. Copyright © 2011 Wiley-Liss, Inc.

  1. The effects of TSH on human vascular endothelial cells and smooth muscle cells

    Institute of Scientific and Technical Information of China (English)

    田利民

    2014-01-01

    Objective To study the effect of thyroid-stimulating hormone(TSH)on human vascular endothelial cells and smooth muscle cells and to explore the roles of TSH in the development of atherosclerosis.Methods Human vascular endothelial cells and smooth muscle cells were cultured in vitro.MTT method was used to assay the effect of TSH on cell viability.Real-time PCR was used

  2. RBP-J (Rbpsuh) is essential to maintain muscle progenitor cells and to generate satellite cells

    OpenAIRE

    Vasyutina, Elena; Lenhard, Diana C.; Wende, Hagen; Erdmann, Bettina; Epstein, Jonathan A.; Birchmeier, Carmen

    2007-01-01

    In the developing muscle, a pool of myogenic progenitor cells is formed and maintained. These resident progenitors provide a source of cells for muscle growth in development and generate satellite cells in the perinatal period. By the use of conditional mutagenesis in mice, we demonstrate here that the major mediator of Notch signaling, the transcription factor RBP-J, is essential to maintain this pool of progenitor cells in an undifferentiated state. In the absence of RBP-J, these cells unde...

  3. The Role of Vitamin D in Skeletal and Cardiac Muscle Function

    Directory of Open Access Journals (Sweden)

    Patsie ePolly

    2014-04-01

    Full Text Available Myopathy is a feature of many inflammatory syndromes. Chronic inflammation has been linked to pathophysiological mechanisms which implicate 1,25 dihydroxyvitamin D3 (1,25-(OH2D3-mediated signaling pathways with emerging evidence supporting a role for the vitamin D receptor (VDR in contractile and metabolic function of both skeletal and cardiac muscle. Altered VDR expression in skeletal and cardiac muscle has been reported to result in significant effects on metabolism, calcium signaling and fibrosis in these tissues. Elevated levels of serum inflammatory cytokines, such as IL-6, TNF- and IFN, have been shown to impact myogenic and nuclear receptor signaling pathways in cancer-induced cachexia. The dysregulation of nuclear receptors, such as VDR and RXR in muscle cells, has also been postulated to result in myopathy via their effects on muscle structural integrity and metabolism. Future research directions include generating transcriptome-wide information incorporating VDR and its gene targets and using systems biology approaches to identify altered molecular networks in human tissues such as muscle. These approaches will aid in the development of novel therapeutic targeting strategies for inflammation-induced myopathies.

  4. Does phototherapy enhance skeletal muscle contractile function and postexercise recovery? A systematic review.

    Science.gov (United States)

    Borsa, Paul A; Larkin, Kelly A; True, Jerry M

    2013-01-01

    Recently, researchers have shown that phototherapy administered to skeletal muscle immediately before resistance exercise can enhance contractile function, prevent exercise-induced cell damage, and improve postexercise recovery of strength and function. To critically evaluate original research addressing the ability of phototherapeutic devices, such as lasers and light-emitting diodes (LEDs), to enhance skeletal muscle contractile function, reduce exercise-induced muscle fatigue, and facilitate postexercise recovery. We searched the electronic databases PubMed, SPORTDiscus, Web of Science, Scopus, and Rehabilitation & Physical Medicine without date limitations for the following key words: laser therapy, phototherapy, fatigue, exercise, circulation, microcirculation, and photobiomodulation. Eligible studies had to be original research published in English as full papers, involve human participants, and receive a minimum score of 7 out of 10 on the Physiotherapy Evidence Database (PEDro) scale. Data of interest included elapsed time to fatigue, total number of repetitions to fatigue, total work performed, maximal voluntary isometric contraction (strength), electromyographic activity, and postexercise biomarker levels. We recorded the PEDro scores, beam characteristics, and treatment variables and calculated the therapeutic outcomes and effect sizes for the data sets. In total, 12 randomized controlled trials met the inclusion criteria. However, we excluded data from 2 studies, leaving 32 data sets from 10 studies. Twenty-four of the 32 data sets contained differences between active phototherapy and sham (placebo-control) treatment conditions for the various outcome measures. Exposing skeletal muscle to single-diode and multidiode laser or multidiode LED therapy was shown to positively affect physical performance by delaying the onset of fatigue, reducing the fatigue response, improving postexercise recovery, and protecting cells from exercise-induced damage

  5. Post-mitotic role of nucleostemin as a promoter of skeletal muscle cell differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, Hiroyuki; Romanova, Liudmila; Kellner, Steven; Verma, Mayank; Rayner, Samuel [Stem Cell Institute, University of Minnesota, Room 2-216, MTRF, 2001 6th St. SE, Minneapolis, MN 55455 (United States); Asakura, Atsushi, E-mail: asakura@umn.edu [Stem Cell Institute, University of Minnesota, Room 2-216, MTRF, 2001 6th St. SE, Minneapolis, MN 55455 (United States); Kikyo, Nobuaki, E-mail: kikyo001@umn.edu [Stem Cell Institute, University of Minnesota, Room 2-216, MTRF, 2001 6th St. SE, Minneapolis, MN 55455 (United States)

    2010-01-01

    Nucleostemin (NS) is a nucleolar protein abundantly expressed in a variety of proliferating cells and undifferentiated cells. Its known functions include cell cycle regulation and the control of pre-rRNA processing. It also has been proposed that NS has an additional role in undifferentiated cells due to its downregulation during stem cell differentiation and its upregulation during tissue regeneration. Here, however, we demonstrate that skeletal muscle cell differentiation has a unique expression profile of NS in that it is continuously expressed during differentiation. NS was expressed at similar levels in non-proliferating muscle stem cells (satellite cells), rapidly proliferating precursor cells (myoblasts) and post-mitotic terminally differentiated cells (myotubes and myofibers). The sustained expression of NS during terminal differentiation is necessary to support increased protein synthesis during this process. Downregulation of NS inhibited differentiation of myoblasts to myotubes, accompanied by striking downregulation of key myogenic transcription factors, such as myogenin and MyoD. In contrast, upregulation of NS inhibited proliferation and promoted muscle differentiation in a p53-dependent manner. Our findings provide evidence that NS has an unexpected role in post-mitotic terminal differentiation. Importantly, these findings also indicate that, contrary to suggestions in the literature, the expression of NS cannot always be used as a reliable indicator for undifferentiated cells or proliferating cells.

  6. Muscle Satellite Cells: Exploring the Basic Biology to Rule Them.

    Science.gov (United States)

    Almeida, Camila F; Fernandes, Stephanie A; Ribeiro Junior, Antonio F; Keith Okamoto, Oswaldo; Vainzof, Mariz

    2016-01-01

    Adult skeletal muscle is a postmitotic tissue with an enormous capacity to regenerate upon injury. This is accomplished by resident stem cells, named satellite cells, which were identified more than 50 years ago. Since their discovery, many researchers have been concentrating efforts to answer questions about their origin and role in muscle development, the way they contribute to muscle regeneration, and their potential to cell-based therapies. Satellite cells are maintained in a quiescent state and upon requirement are activated, proliferating, and fusing with other cells to form or repair myofibers. In addition, they are able to self-renew and replenish the stem pool. Every phase of satellite cell activity is highly regulated and orchestrated by many molecules and signaling pathways; the elucidation of players and mechanisms involved in satellite cell biology is of extreme importance, being the first step to expose the crucial points that could be modulated to extract the optimal response from these cells in therapeutic strategies. Here, we review the basic aspects about satellite cells biology and briefly discuss recent findings about therapeutic attempts, trying to raise questions about how basic biology could provide a solid scaffold to more successful use of these cells in clinics.

  7. 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

  8. 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

  9. EMG study for perioral facial muscles function during mastication.

    Science.gov (United States)

    Hanawa, S; Tsuboi, A; Watanabe, M; Sasaki, K

    2008-03-01

    This study aimed to clarify the temporal and quantitative modulation in the orbicularis oris (OO) and buccinator (BUC) muscle activities during mastication. Ten healthy males (26.9 +/- 1.0 years) participated. Electromyograms (EMGs) of the facial muscles were recorded with fine wire electrodes when chewing the chewing gum (one to four sticks) and peanuts (one to five pieces). Surface EMGs of the masseter (MAS) and digastric muscles were recorded simultaneously. EMGs of the OO and BUC showed rhythmic single-peaked bursts corresponding to the jaw-opening phase of chewing cycles. The total cycle lengths were constant regardless of the food amount. Integrated EMGs of the OO changed significantly when the amount of both foods changed (anova: P < 0.05). Those of the BUC changed significantly with the amount of gum changed (P < 0.05), but did not change with the amount of peanuts changed. The burst duration of OO changed significantly when the amount of gum changed during ipsilateral chewing (P < 0.05). When the amount of peanuts changed during ipsilateral chewing, the onset of OO and the peak of BUC based on the onset of MAS activity changed significantly (P < 0.05). However, the onset, peak and offset of the OO and BUC based on the offset of MAS did not change regardless of the amounts chewed. The changes of the OO and BUC activities may derive from chewing-generated sensory inputs in accordance with the physical property of food in part, which would relate to the function of these muscles during mastication.

  10. 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.

  11. IFN-γ promotes muscle damage in the mdx mouse model of Duchenne muscular dystrophy by suppressing M2 macrophage activation and inhibiting muscle cell proliferation.

    Science.gov (United States)

    Villalta, S Armando; Deng, Bo; Rinaldi, Chiara; Wehling-Henricks, Michelle; Tidball, James G

    2011-11-15

    Duchenne muscular dystrophy is a degenerative disorder that leads to death by the third decade of life. Previous investigations have shown that macrophages that invade dystrophic muscle are a heterogeneous population consisting of M1 and M2 macrophages that promote injury and repair, respectively. In the present investigation, we tested whether IFN-γ worsens the severity of mdx dystrophy by activating macrophages to a cytolytic M1 phenotype and by suppressing the activation of proregenerative macrophages to an M2 phenotype. IFN-γ is a strong inducer of the M1 phenotype and is elevated in mdx dystrophy. Contrary to our expectations, null mutation of IFN-γ caused no reduction of cytotoxicity of macrophages isolated from mdx muscle and did not reduce muscle fiber damage in vivo or improve gross motor function of mdx mice at the early, acute peak of pathology. In contrast, ablation of IFN-γ reduced muscle damage in vivo during the regenerative stage of the disease and increased activation of the M2 phenotype and improved motor function of mdx mice at that later stage of the disease. IFN-γ also inhibited muscle cell proliferation and differentiation in vitro, and IFN-γ mutation increased MyoD expression in mdx muscle in vivo, showing that IFN-γ can have direct effects on muscle cells that could impair repair. Taken together, the findings show that suppression of IFN-γ signaling in muscular dystrophy reduces muscle damage and improves motor performance by promoting the M2 macrophage phenotype and by direct actions on muscle cells.

  12. Does adiposity affect muscle function during walking in children?

    Science.gov (United States)

    Lerner, Zachary F; Shultz, Sarah P; Board, Wayne J; Kung, Stacey; Browning, Raymond C

    2014-09-22

    The biomechanical mechanisms responsible for the altered gait in obese children are not well understood, particularly as they relate to increases in adipose tissue. The purpose of this study was to test the hypotheses that as body-fat percentage (BF%) increased: (1) knee flexion during stance would decrease while pelvic obliquity would increase; (2) peak muscle forces normalized to lean-weight would increase for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti; and (3) the individual muscle contributions to center of mass (COM) acceleration in the direction of their primary function(s) would not change for gluteus medius, gastrocnemius, and soleus, but decrease for the vasti. We scaled a musculoskeletal model to the anthropometrics of each participant (n=14, 8-12 years old, BF%: 16-41%) and estimated individual muscle forces and their contributions to COM acceleration. BF% was correlated with average knee flexion angle during stance (r=-0.54, p=0.024) and pelvic obliquity range of motion (r=0.78, p<0.001), as well as with relative vasti (r=-0.60, p=0.023), gluteus medius (r=0.65, p=0.012) and soleus (r=0.59, p=0.026) force production. Contributions to COM acceleration from the vasti were negatively correlated to BF% (vertical-- r=-0.75, p=0.002, posterior-- r=-0.68, p=0.008), but there were no correlation between BF% and COM accelerations produced by the gastrocnemius, soleus and gluteus medius. Therefore, we accept our first, partially accept our second, and accept our third hypotheses. The functional demands and relative force requirements of the hip abductors during walking in pediatric obesity may contribute to altered gait kinematics. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

    Science.gov (United States)

    Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

    2011-01-01

    Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

  14. Implantation of muscle satellite cells overexpressing myogenin improves denervated muscle atrophy in rats

    Directory of Open Access Journals (Sweden)

    H. Shen

    2016-01-01

    Full Text Available This study evaluated the effect of muscle satellite cells (MSCs overexpressing myogenin (MyoG on denervated muscle atrophy. Rat MSCs were isolated and transfected with the MyoG-EGFP plasmid vector GV143. MyoG-transfected MSCs (MTMs were transplanted into rat gastrocnemius muscles at 1 week after surgical denervation. Controls included injections of untransfected MSCs or the vehicle only. Muscles were harvested and analyzed at 2, 4, and 24 weeks post-transplantation. Immunofluorescence confirmed MyoG overexpression in MTMs. The muscle wet weight ratio was significantly reduced at 2 weeks after MTM injection (67.17±6.79 compared with muscles injected with MSCs (58.83±5.31 or the vehicle (53.00±7.67; t=2.37, P=0.04 and t=3.39, P=0.007, respectively. The muscle fiber cross-sectional area was also larger at 2 weeks after MTM injection (2.63×103±0.39×103 compared with MSC injection (1.99×103±0.58×103 or the vehicle only (1.57×103±0.47×103; t=2.24, P=0.049 and t=4.22, P=0.002, respectively. At 4 and 24 weeks post-injection, the muscle mass and fiber cross-sectional area were similar across all three experimental groups. Immunohistochemistry showed that the MTM group had larger MyoG-positive fibers. The MTM group (3.18±1.13 also had higher expression of MyoG mRNA than other groups (1.41±0.65 and 1.03±0.19 at 2 weeks after injection (t=2.72, P=0.04. Transplanted MTMs delayed short-term atrophy of denervated muscles. This approach can be optimized as a novel stand-alone therapy or as a bridge to surgical re-innervation of damaged muscles.

  15. Implantation of muscle satellite cells overexpressing myogenin improves denervated muscle atrophy in rats.

    Science.gov (United States)

    Shen, H; Lv, Y; Shen, X Q; Xu, J H; Lu, H; Fu, L C; Duan, T

    2016-02-01

    This study evaluated the effect of muscle satellite cells (MSCs) overexpressing myogenin (MyoG) on denervated muscle atrophy. Rat MSCs were isolated and transfected with the MyoG-EGFP plasmid vector GV143. MyoG-transfected MSCs (MTMs) were transplanted into rat gastrocnemius muscles at 1 week after surgical denervation. Controls included injections of untransfected MSCs or the vehicle only. Muscles were harvested and analyzed at 2, 4, and 24 weeks post-transplantation. Immunofluorescence confirmed MyoG overexpression in MTMs. The muscle wet weight ratio was significantly reduced at 2 weeks after MTM injection (67.17±6.79) compared with muscles injected with MSCs (58.83±5.31) or the vehicle (53.00±7.67; t=2.37, P=0.04 and t=3.39, P=0.007, respectively). The muscle fiber cross-sectional area was also larger at 2 weeks after MTM injection (2.63×10³±0.39×10³) compared with MSC injection (1.99×10³±0.58×10³) or the vehicle only (1.57×10³±0.47×10³; t=2.24, P=0.049 and t=4.22, P=0.002, respectively). At 4 and 24 weeks post-injection, the muscle mass and fiber cross-sectional area were similar across all three experimental groups. Immunohistochemistry showed that the MTM group had larger MyoG-positive fibers. The MTM group (3.18±1.13) also had higher expression of MyoG mRNA than other groups (1.41±0.65 and 1.03±0.19) at 2 weeks after injection (t=2.72, P=0.04). Transplanted MTMs delayed short-term atrophy of denervated muscles. This approach can be optimized as a novel stand-alone therapy or as a bridge to surgical re-innervation of damaged muscles.

  16. The effect of temperature on proliferation and differentiation of chicken skeletal muscle satellite cells isolated from different muscle types.

    Science.gov (United States)

    Harding, Rachel L; Halevy, Orna; Yahav, Shlomo; Velleman, Sandra G

    2016-04-01

    Skeletal muscle satellite cells are a muscle stem cell population that mediate posthatch muscle growth and repair. Satellite cells respond differentially to environmental stimuli based upon their fiber-type of origin. The objective of this study was to determine how temperatures below and above the in vitro control of 38°C affected the proliferation and differentiation of satellite cells isolated from the chicken anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b.femoris) muscles. The satellite cells isolated from the p. major muscle were more sensitive to both cold and hot temperatures compared to the b.femoris satellite cells during both proliferation and differentiation. The expressions of myogenic regulatory transcription factors were also different between satellite cells from different fiber types. MyoD expression, which partially regulates proliferation, was generally expressed at higher levels in p. major satellite cells compared to the b.femoris satellite cells from 33 to 43°C during proliferation and differentiation. Similarly, myogenin expression, which is required for differentiation, was also expressed at higher levels in p. major satellite cells in response to both cold and hot temperatures during proliferation and differentiation than b. femoris satellite cells. These data demonstrate that satellite cells from the anaerobic p. major muscle are more sensitive than satellite cells from the aerobic b. femoris muscle to both hot and cold thermal stress during myogenic proliferation and differentiation.

  17. Effect of Nateglinide and Glibenclamide on Endothelial Cells and Smooth Muscle Cells from Human Coronary Arteries

    Directory of Open Access Journals (Sweden)

    Seeger H

    2004-01-01

    Full Text Available In the present work the effect of nateglinide and glibenclamide, two different substances used for therapy of diabetes mellitus type 2, were investigated on the synthesis of markers of endothelial function and on the proliferation of smooth muscle cells in vitro. As cell models endothelial and smooth muscle cells from human coronary arteries were used. Both substances were tested at concentrations of 0.1, 1 and 10 mmol/l. As markers of endothelial function prostacyclin, endothelin and plasminogen-activator-inhibitor-1 (PAI-1 were tested. Nateglinide and glibenclamide were similarly able to inhibit endothelial endothelin and PAI-1 synthesis, but only at the highest concentration tested. Endothelial prostacyclin synthesis and proliferation of smooth muscle cells were not significantly changed by both substances. These results indicate that both nateglinide and glibenclamide may have potential in reducing negative long-term effects of diabetes such as atherogenesis. Kurzfassung: Effekt von Nateglinid und Glibenclamid auf Endothel- und Muskelzellen humaner Koronararterien. In der vorliegenden Arbeit wurde die Wirkung von Nateglinid und Glibenclamid, zweier unterschiedlicher Substanzen zur Behandlung des Diabetes mellitus Typ 2, auf die Synthese von Markern der Endothelfunktion und auf die Proliferation glatter Muskelzellen untersucht. Als Zellmodell dienten Endothelzellen und glatte Muskelzellen menschlicher Koronararterien. Beide Substanzen wurden in den Konzentrationen 0,1, 1 und 10 mmol/l getestet. Als Marker der Endothelfunktion dienten Prostazyklin, Endothelin und Plasminogen-Aktivator-Inhibitor-1 (PAI-1. Sowohl Nateglinid als auch Glibenclamid konnten die endotheliale Endothelin- und PAI-1-Produktion in ähnlichem Ausmaß senken, allerdings nur in der höchsten Konzentration. Die Prostazyklinsynthese und die Muskelzellproliferation wurden nicht signifikant beeinflußt. Diese Ergebnisse deuten daraufhin, daß sowohl Nateglinid als auch

  18. Muscle biopsy and cell cultures: potential diagnostic tools in hereditary skeletal muscle channelopathies

    Directory of Open Access Journals (Sweden)

    G Meola

    2009-06-01

    Full Text Available Hereditary muscle channelopathies are caused by dominant mutations in the genes encoding for subunits of muscle voltage- gated ion channels. Point mutations on the human skeletal muscle Na+ channel (Nav1.4 give rise to hyperkalemic periodic paralysis, potassium aggravated myotonia, paramyotonia congenita and hypokalemic periodic paralysis type 2. Point mutations on the human skeletal muscle Ca2+ channel give rise to hypokalemic periodic paralysis and malignant hyperthermia. Point mutations in the human skeletal chloride channel ClC-1 give rise to myotonia congenita. Point mutations in the inwardly rectifying K+ channel Kir2.1 give rise to a syndrome characterized by periodic paralysis, severe cardiac arrhythmias and skeletal alterations (Andersen’s syndrome. Involvement of the same ion channel can thus give rise to different phenotypes. In addition, the same mutation can lead to different phenotypes or similar phenotypes can be caused by different mutations on the same or on different channel subtypes. Bearing in mind, the complexity of this field, the growing number of potential channelopathies (such as the myotonic dystrophies, and the time and cost of the genetic procedures, before a biomolecular approach is addressed, it is mandatory to apply strict diagnostic protocols to screen the patients. In this study we propose a protocol to be applied in the diagnosis of the hereditary muscle channelopathies and we demonstrate that muscle biopsy studies and muscle cell cultures may significantly contribute towards the correct diagnosis of the channel involved. DNAbased diagnosis is now a reality for many of the channelopathies. This has obvious genetic counselling, prognostic and therapeutic implications.

  19. Vascular smooth muscle cells express the alpha(1A) subunit of a P-/Q-type voltage-dependent Ca(2+)Channel, and It is functionally important in renal afferent arterioles

    DEFF Research Database (Denmark)

    Hansen, Pernille B. Lærkegaard; Jensen, Boye L.; Andreasen, D

    2000-01-01

    in rat aorta, brain, aortic smooth muscle cells (A7r5), VSMCs, and mesangial cells. Immunolabeling with an anti-alpha(1A) antibody was positive in acid-macerated, microdissected preglomerular vessels and in A7r5 cells. Patch-clamp experiments on aortic A7r5 cells showed 22+/-4% (n=6) inhibition of inward...... Ca(2+) current by omega-Agatoxin IVA (10(-8) mol/L), which in this concentration is a specific inhibitor of P-type VDCCs. Measurements of intracellular Ca(2+) in afferent arterioles with fluorescence-imaging microscopy showed 32+/-9% (n=10) inhibition of the K(+)-induced rise in Ca(2...... preglomerular resistance vessels and aorta, as well as mesangial cells, and that P-type VDCCs contribute to Ca(2+) influx in aortic and renal VSMCs and are involved in depolarization-mediated contraction in renal afferent arterioles....

  20. Alterations in intrinsic mitochondrial function with aging are fiber type-specific and do not explain differential atrophy between muscles.

    Science.gov (United States)

    Picard, Martin; Ritchie, Darmyn; Thomas, Melissa M; Wright, Kathryn J; Hepple, Russell T

    2011-12-01

    To determine whether mitochondrial dysfunction is causally related to muscle atrophy with aging, we examined respiratory capacity, H(2) O(2) emission, and function of the mitochondrial permeability transition pore (mPTP) in permeabilized myofibers prepared from four rat muscles that span a range of fiber type and degree of age-related atrophy. Muscle atrophy with aging was greatest in fast-twitch gastrocnemius (Gas) muscle (-38%), intermediate in both the fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (Sol) muscles (-21%), and non-existent in adductor longus (AL) muscle (+47%). In contrast, indices of mitochondrial dysfunction did not correspond to this differential degree of atrophy. Specifically, despite higher protein expression for oxidative phosphorylation (oxphos) system in fast Gas and EDL, state III respiratory capacity per myofiber wet weight was unchanged with aging, whereas the slow Sol showed proportional decreases in oxphos protein, citrate synthase activity, and state III respiration. Free radical leak (H(2) O(2) emission per O(2) flux) under state III respiration was higher with aging in the fast Gas, whereas state II free radical leak was higher in the slow AL. Only the fast muscles had impaired mPTP function with aging, with lower mitochondrial calcium retention capacity in EDL and shorter time to mPTP opening in Gas and EDL. Collectively, our results underscore that the age-related changes in muscle mitochondrial function depend largely upon fiber type and are unrelated to the severity of muscle atrophy, suggesting that intrinsic changes in mitochondrial function are unlikely to be causally involved in aging muscle atrophy. © 2011 The Authors. Aging Cell © 2011 Blackwell Publishing Ltd/Anatomical Society of Great Britain and Ireland.

  1. Effects of protein supplements on muscle damage, soreness and recovery of muscle function and physical performance: a systematic review.

    Science.gov (United States)

    Pasiakos, Stefan M; Lieberman, Harris R; McLellan, Tom M

    2014-05-01

    Protein supplements are frequently consumed by athletes and recreationally-active individuals, although the decision to purchase and consume protein supplements is often based on marketing claims rather than evidence-based research. To provide a systematic and comprehensive analysis of literature examining the hypothesis that protein supplements enhance recovery of muscle function and physical performance by attenuating muscle damage and soreness following a previous bout of exercise. English language articles were searched with PubMed and Google Scholar using protein and supplements together with performance, exercise, competition and muscle, alone or in combination as keywords. Inclusion criteria required studies to recruit healthy adults less than 50 years of age and to evaluate the effects of protein supplements alone or in combination with carbohydrate on performance metrics including time-to-exhaustion, time-trial or isometric or isokinetic muscle strength and markers of muscle damage and soreness. Twenty-seven articles were identified of which 18 dealt exclusively with ingestion of protein supplements to reduce muscle damage and soreness and improve recovery of muscle function following exercise, whereas the remaining 9 articles assessed muscle damage as well as performance metrics during single or repeat bouts of exercise. Papers were evaluated based on experimental design and examined for confounders that explain discrepancies between studies such as dietary control, training state of participants, sample size, direct or surrogate measures of muscle damage, and sensitivity of the performance metric. High quality and consistent data demonstrated there is no apparent relationship between recovery of muscle function and ratings of muscle soreness and surrogate markers of muscle damage when protein supplements are consumed prior to, during or after a bout of endurance or resistance exercise. There also appears to be insufficient experimental data

  2. Muscle activity during functional coordination training: implications for strength gain and rehabilitation

    DEFF Research Database (Denmark)

    Jørgensen, Marie Birk; Andersen, Lars Louis; Kirk, Niels

    2010-01-01

    The purpose of this study was to evaluate if different types, body positions, and levels of progression of functional coordination exercises can provide sufficiently high levels of muscle activity to improve strength of the neck, shoulder, and trunk muscles. Nine untrained women were familiarized...... training can be performed with a muscle activity sufficient for strength gain. Functional coordination training may therefore be a good choice for prevention or rehabilitation of musculoskeletal pain or injury in the neck, shoulder, or trunk muscles....

  3. Scaling functional patterns of skeletal and cardiac muscles: New non-linear elasticity approach

    CERN Document Server

    Kokshenev, Valery B

    2009-01-01

    Responding mechanically to environmental requests, muscles show a surprisingly large variety of functions. The studies of in vivo cycling muscles qualified skeletal muscles into four principal locomotor patterns: motor, brake, strut, and spring. While much effort of has been done in searching for muscle design patterns, no fundamental concepts underlying empirically established patterns were revealed. In this interdisciplinary study, continuum mechanics is applied to the problem of muscle structure in relation to function. The ability of a powering muscle, treated as a homogenous solid organ, tuned to efficient locomotion via the natural frequency is illuminated through the non-linear elastic muscle moduli controlled by contraction velocity. The exploration of the elastic force patterns known in solid state physics incorporated in activated skeletal and cardiac muscles via the mechanical similarity principle yields analytical rationalization for locomotor muscle patterns. Besides the explanation of the origin...

  4. Tetranectin is a novel marker for myogenesis during embryonic development, muscle regeneration, and muscle cell differentiation in vitro

    DEFF Research Database (Denmark)

    Wewer, U M; Iba, K; Durkin, M E

    1998-01-01

    cells in dystrophic mdx mice. Murine C2C12 myogenic cells and pluripotent embryonic stem cells can undergo muscle cell differentiation in vitro. Tetranectin is not expressed in the undifferentiated myogenic cells, but during the progression of muscle differentiation, tetranectin mRNA is induced......Tetranectin, a plasminogen-binding protein with a C-type lectin domain, is found in both serum and the extracellular matrix. In the present study we report that tetranectin is closely associated with myogenesis during embryonic development, skeletal muscle regeneration, and muscle cell...... differentiation in vitro. We find that tetranectin expression coincides with muscle differentiation and maturation in the second half of gestation and further that tetranectin is enriched at the myotendinous and myofascial junctions. The tetranectin immunostaining declines after birth and no immunostaining...

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

    Science.gov (United States)

    Farup, Jean; Rahbek, Stine Klejs; Riis, Simon; Vendelbo, Mikkel Holm; Paoli, Frank de; Vissing, Kristian

    2014-10-15

    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-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) 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 hypertrophy correlated with whole muscle hypertrophy exclusively following Conc training (P eccentric resistance training while type II fiber hypertrophy was accentuated when combining concentric resistance training with whey protein supplementation.

  6. Invited review: Stem cells and muscle diseases: advances in cell therapy strategies.

    Science.gov (United States)

    Negroni, Elisa; Gidaro, Teresa; Bigot, Anne; Butler-Browne, Gillian S; Mouly, Vincent; Trollet, Capucine

    2015-04-01

    Despite considerable progress to increase our understanding of muscle genetics, pathophysiology, molecular and cellular partners involved in muscular dystrophies and muscle ageing, there is still a crucial need for effective treatments to counteract muscle degeneration and muscle wasting in such conditions. This review focuses on cell-based therapy for muscle diseases. We give an overview of the different parameters that have to be taken into account in such a therapeutic strategy, including the influence of muscle ageing, cell proliferation and migration capacities, as well as the translation of preclinical results in rodent into human clinical approaches. We describe recent advances in different types of human myogenic stem cells, with a particular emphasis on myoblasts but also on other candidate cells described so far [CD133+ cells, aldehyde dehydrogenase-positive cells (ALDH+), muscle-derived stem cells (MuStem), embryonic stem cells (ES) and induced pluripotent stem cells (iPS)]. Finally, we provide an update of ongoing clinical trials using cell therapy strategies.

  7. Regulation of collagen biosynthesis in cultured bovine aortic smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    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 (/sup 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 ..cap alpha..1 and ..cap alpha..2 chains of type I and the ..cap alpha..1 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.

  8. 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.

  9. Functional compartmentalization of the human superficial masseter muscle.

    Directory of Open Access Journals (Sweden)

    Rodrigo A Guzmán-Venegas

    Full Text Available Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM muscle's motor units using high-density surface electromyography (EMGs at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF were randomly requested. Using a two-dimensional grid (four columns, six electrodes located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001.The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001. The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001. The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF.

  10. Functional compartmentalization of the human superficial masseter muscle.

    Science.gov (United States)

    Guzmán-Venegas, Rodrigo A; Biotti Picand, Jorge L; de la Rosa, Francisco J Berral

    2015-01-01

    Some muscles have demonstrated a differential recruitment of their motor units in relation to their location and the nature of the motor task performed; this involves functional compartmentalization. There is little evidence that demonstrates the presence of a compartmentalization of the superficial masseter muscle during biting. The aim of this study was to describe the topographic distribution of the activity of the superficial masseter (SM) muscle's motor units using high-density surface electromyography (EMGs) at different bite force levels. Twenty healthy natural dentate participants (men: 4; women: 16; age 20±2 years; mass: 60±12 kg, height: 163±7 cm) were selected from 316 volunteers and included in this study. Using a gnathodynamometer, bites from 20 to 100% maximum voluntary bite force (MVBF) were randomly requested. Using a two-dimensional grid (four columns, six electrodes) located on the dominant SM, EMGs in the anterior, middle-anterior, middle-posterior and posterior portions were simultaneously recorded. In bite ranges from 20 to 60% MVBF, the EMG activity was higher in the anterior than in the posterior portion (p-value = 0.001).The center of mass of the EMG activity was displaced towards the posterior part when bite force increased (p-value = 0.001). The topographic distribution of EMGs was more homogeneous at high levels of MVBF (p-value = 0.001). The results of this study show that the superficial masseter is organized into three functional compartments: an anterior, a middle and a posterior compartment. However, this compartmentalization is only seen at low levels of bite force (20-60% MVBF).

  11. Interrelations of muscle functional MRI, diffusion-weighted MRI and (31) P-MRS in exercised lower back muscles.

    Science.gov (United States)

    Hiepe, Patrick; Gussew, Alexander; Rzanny, Reinhard; Anders, Christoph; Walther, Mario; Scholle, Hans-Christoph; Reichenbach, Jürgen R

    2014-08-01

    Exercise-induced changes of transverse proton relaxation time (T2 ), tissue perfusion and metabolic turnover were investigated in the lower back muscles of volunteers by applying muscle functional MRI (mfMRI) and diffusion-weighted imaging (DWI) before and after as well as dynamic (31) P-MRS during the exercise. Inner (M. multifidus, MF) and outer lower back muscles (M. erector spinae, ES) were examined in 14 healthy young men performing a sustained isometric trunk-extension. Significant phosphocreatine (PCr) depletions ranging from 30% (ES) to 34% (MF) and Pi accumulations between 95% (left ES) and 120%-140% (MF muscles and right ES) were observed during the exercise, which were accompanied by significantly decreased pH values in all muscles (∆pH ≈ -0.05). Baseline T2 values were similar across all investigated muscles (approximately 27 ms at 3 T), but revealed right-left asymmetric increases (T2 ,inc ) after the exercise (right ES/MF: T2 ,inc  = 11.8/9.7%; left ES/MF: T2 ,inc  = 4.6/8.9%). Analyzed muscles also showed load-induced increases in molecular diffusion D (p = .007) and perfusion fraction f (p = .002). The latter parameter was significantly higher in the MF than in the ES muscles both at rest and post exercise. Changes in PCr (p = .03), diffusion (p muscles.

  12. Function of longitudinal vs circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

    Institute of Scientific and Technical Information of China (English)

    James G Brasseur; Mark A Nicosia; Anupam Pal; Larr S Miller

    2007-01-01

    We summarize from previous works the functions of circular vs. longitudinal muscle in esophageal peristaltic bolus transport using a mix of experimental data, the conservation laws of mechanics and mathematical modeling. Whereas circular muscle tone generates radial closure pressure to create a local peristaltic closure wave, longitudinal muscle tone has two functions, one physiological with mechanical implications, and one purely mechanical. Each of these functions independently reduces the tension of individual circular muscle fibers to maintain closure as a consequence of shortening of longitudinal muscle locally coordinated with increasing circular muscle tone. The physiological function is deduced by combining basic laws of mechanics with concurrent measurements of intraluminal pressure from manometry, and changes in cross sectional muscle area from endoluminal ultrasound from which local longitudinal shortening (LLS) can be accurately obtained. The purely mechanical function of LLS was discovered from mathematical modeling of peristaltic esophageal transport with the axial wall motion generated by LLS. Physiologically, LLS concentrates circular muscle fibers where closure pressure is highest.However, the mechanical function of LLS is to reduce the level of pressure required to maintain closure. The combined physiological and mechanical consequences of LLS are to reduce circular muscle fiber tension and power by as much as 1/10 what would be required for peristalsis without the longitudinal muscle layer, a tremendous benefit that may explain the existence of longitudinal muscle fiber in the gut. We also review what is understood of the role of longitudinal muscle in esophageal emptying, reflux and pathology.

  13. Triptolide inhibits TGF-β1-induced cell proliferation in rat airway smooth muscle cells by suppressing Smad signaling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ming; Lv, Zhiqiang; Huang, Linjie [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China); Zhang, Wei [Department of Geratology, the Second People' s Hospital of Shenzhen, Shenzhen 518000 (China); Lin, Xiaoling; Shi, Jianting; Zhang, Wei; Liang, Ruiyun [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China); Jiang, Shanping, E-mail: shanpingjiang@126.com [Department of Respiratory Medicine, Sun Yat-Sen Memorial Hospital, Institute for Respiratory disease of Sun Yat-sen University, Sun Yat-sen University, Guangzhou, Guangdong Province 510120 (China)

    2015-02-15

    Background: We have reported that triptolide can inhibit airway remodeling in a murine model of asthma via TGF-β1/Smad signaling. In the present study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation and the possible mechanism. Methods: Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentration of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle and apoptosis. Signal proteins (Smad2, Smad3 and Smad7) were detected by western blotting analysis. Results: Triptolide significantly inhibited TGF-β1-induced ASMC proliferation (P<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. No pro-apoptotic effects were detected under the concentration of triptolide we used. Western blotting analysis showed TGF-β1 induced Smad2 and Smad3 phosphorylation was inhibited by triptolide pretreatment, and the level of Smad7 was increased by triptolide pretreatment. Conclusions: Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation via negative regulation of Smad signaling pathway. - Highlights: • In this study, rat airway smooth muscle cells were cultured and made synchronized. • Triptolide inhibited TGF-β1-induced airway smooth muscle cells proliferation. • Triptolide inhibited ASMCs proliferation via negative regulation of Smad signaling pathway.

  14. Beta-Adrenergic Receptor Expression in Muscle Cells

    Science.gov (United States)

    Young, Ronald B.; Bridge, K.; Vaughn, J. R.

    1999-01-01

    beta-adrenergic receptor (bAR) agonists presumably exert their physiological action on skeletal muscle cells through the bAR. Since the signal generated by the bAR is cyclic AMP (cAMP), experiments were initiated in primary chicken muscle cell cultures to determine if artificial elevation of intracellular cAMP by treatment with forskolin would alter the population of bAR expressed on the surface of muscle cells. Chicken skeletal muscle cells after 7 days in culture were employed for the experiments because muscle cells have attained a steady state with respect to muscle protein metabolism at this stage. Cells were treated with 0-10 uM forskolin for a total of three days. At the end of the 1, 2, and 3 day treatment intervals, the concentration of cAMP and the bAR population were measured. Receptor population was measured in intact muscle cell cultures as the difference between total binding of [H-3]CGP-12177 and non-specific binding of [H-3]CGP-12177 in the presence of 1 uM propranolol. Intracellular cAMP concentration was measured by radioimmunoassay. The concentration of cAMP in forskolin-treated cells increased up to 10-fold in a dose dependent manner. Increasing concentrations of forskolin also led to an increase in (beta)AR population, with a maximum increase of approximately 50% at 10 uM. This increase in (beta)AR population was apparent after only 1 day of treatment, and the pattern of increase was maintained for all 3 days of the treatment period. Thus, increasing the intracellular concentration of cAMP leads to up-regulation of (beta)AR population. Clenbuterol and isoproterenol gave similar effects on bAR population. The effect of forskolin on the quantity and apparent synthesis rate of the heavy chain of myosin (mhc) were also investigated. A maximum increase of 50% in the quantity of mhc was observed at 0.2 UM forskolin, but higher concentrations of forskolin reduced the quantity of mhc back to control levels.

  15. Tetraspanin CD9 regulates cell contraction and actin arrangement via RhoA in human vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Michael J Herr

    Full Text Available The most prevalent cardiovascular diseases arise from alterations in vascular smooth muscle cell (VSMC morphology and function. Tetraspanin CD9 has been previously implicated in regulating vascular pathologies; however, insight into how CD9 may regulate adverse VSMC phenotypes has not been provided. We utilized a human model of aortic smooth muscle cells to understand the consequences of CD9 deficiency on VSMC phenotypes. Upon knocking down CD9, the cells developed an abnormally small and rounded morphology. We determined that this morphological change was due to a lack of typical parallel actin arrangement. We also found similar total RhoA but decreased GTP-bound (active RhoA levels in CD9 deficient cells. As a result, cells lacking a full complement of CD9 were less contractile than their control treated counterparts. Upon restoration of RhoA activity in the CD9 deficient cells, the phenotype was reversed and cell contraction was restored. Conversely, inhibition of RhoA activity in the control cells mimicked the CD9-deficient cell phenotype. Thus, alteration in CD9 expression was sufficient to profoundly disrupt cellular actin arrangement and endogenous cell contraction by interfering with RhoA signaling. This study provides insight into how CD9 may regulate previously described vascular smooth muscle cell pathophysiology.

  16. Muscle-specific function of the centronuclear myopathy and Charcot-Marie-Tooth neuropathy-associated dynamin 2 is required for proper lipid metabolism, mitochondria, muscle fibers, neuromuscular junctions and peripheral nerves.

    Science.gov (United States)

    Tinelli, Elisa; Pereira, Jorge A; Suter, Ueli

    2013-11-01

    The ubiquitously expressed large GTPase Dynamin 2 (DNM2) plays a critical role in the regulation of intracellular membrane trafficking through its crucial function in membrane fission, particularly in endocytosis. Autosomal-dominant mutations in DNM2 cause tissue-specific human disorders. Different sets of DNM2 mutations are linked to dominant intermediate Charcot-Marie-Tooth neuropathy type B, a motor and sensory neuropathy affecting primarily peripheral nerves, or autosomal-dominant centronuclear myopathy (CNM) presenting with primary damage in skeletal muscles. To understand the underlying disease mechanisms, it is imperative to determine to which degree the primary affected cell types require DNM2. Thus, we used cell type-specific gene ablation to examine the consequences of DNM2 loss in skeletal muscle cells, the major relevant cell type involved in CNM. We found that DNM2 function in skeletal muscle is required for proper mouse development. Skeletal muscle-specific loss of DNM2 causes a reduction in muscle mass and in the numbers of muscle fibers, altered muscle fiber size distributions, irregular neuromuscular junctions (NMJs) and isolated degenerating intramuscular peripheral nerve fibers. Intriguingly, a lack of muscle-expressed DNM2 triggers an increase of lipid droplets (LDs) and mitochondrial defects. We conclude that loss of DNM2 function in skeletal muscles initiates a chain of harmful parallel and serial events, involving dysregulation of LDs and mitochondrial defects within altered muscle fibers, defective NMJs and peripheral nerve degeneration. These findings provide the essential basis for further studies on DNM2 function and malfunction in skeletal muscles in health and disease, potentially including metabolic diseases such as diabetes.

  17. The anatomy and function of the gluteus minimus muscle.

    Science.gov (United States)

    Beck, M; Sledge, J B; Gautier, E; Dora, C F; Ganz, R

    2000-04-01

    In order to investigate the functional anatomy of gluteus minimus we dissected 16 hips in fresh cadavers. The muscle originates from the external aspect of the ilium, between the anterior and inferior gluteal lines, and also at the sciatic notch from the inside of the pelvis where it protects the superior gluteal nerve and artery. It inserts anterosuperiorly into the capsule of the hip and continues to its main insertion on the greater trochanter. Based on these anatomical findings, a model was developed using plastic bones. A study of its mechanics showed that gluteus minimus acts as a flexor, an abductor and an internal or external rotator, depending on the position of the femur and which part of the muscle is active. It follows that one of its functions is to stabilise the head of the femur in the acetabulum by tightening the capsule and applying pressure on the head. Careful preservation or reattachment of the tendon of gluteus minimus during surgery on the hip is strongly recommended.

  18. Involvement of M-cadherin in terminal differentiation of skeletal muscle cells.

    Science.gov (United States)

    Zeschnigk, M; Kozian, D; Kuch, C; Schmoll, M; Starzinski-Powitz, A

    1995-09-01

    Cadherins are a gene family encoding calcium-dependent cell adhesion proteins which are thought to act in the establishment and maintenance of tissue organization. M-cadherin, one member of the family, has been found in myogenic cells of somitic origin during embryogenesis and in the adult. These findings have suggested that M-cadherin is involved in the regulation of morphogenesis of skeletal muscle cells. Therefore, we investigated the function of M-cadherin in the fusion of myoblasts into myotubes (terminal differentiation) in cell culture. Furthermore, we tested whether M-cadherin might influence (a) the expression of troponin T, a typical marker of biochemical differentiation of skeletal muscle cells, and (b) withdrawal of myoblasts from the cell cycle (called terminal commitment). The studies were performed by using antagonistic peptides which correspond to sequences of the putative M-cadherin binding domain. Analogous peptides of N-cadherin have previously been shown to interfere functionally with the N-cadherin-mediated cell adhesion. In the presence of antagonistic M-cadherin peptides, the fusion of myoblasts into myotubes was inhibited. Analysis of troponin T revealed that it was downregulated at the protein level although its mRNA was still detectable. In addition, withdrawal from the cell cycle typical for terminal commitment of muscle cells was not complete in fusion-blocked myogenic cells. Finally, expression of M-cadherin antisense RNA reducing the expression of the endogenous M-cadherin protein interfered with the fusion process of myoblasts. Our data imply that M-cadherin-mediated myoblast interaction plays an important role in terminal differentiation of skeletal muscle cells.

  19. Satellite Cells Contribution to Exercise Mediated Muscle Hypertrophy and Repair

    Science.gov (United States)

    Bazgir, Behzad; Fathi, Rouhollah; Rezazadeh Valojerdi, Mojtaba; Mozdziak, Paul; Asgari, Alireza

    2017-01-01

    Satellite cells (SCs) are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation the former category being the focus of this article. Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise. PMID:28042532

  20. Satellite Cells Contribution to Exercise Mediated Muscle Hypertrophy and Repair

    Directory of Open Access Journals (Sweden)

    Behzad Bazgir

    2016-10-01

    Full Text Available Satellite cells (SCs are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation - the former category being the focus of this article. Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise.

  1. Plasticity of cerebrovascular smooth muscle cells after subarachnoid hemorrhage

    DEFF Research Database (Denmark)

    Edvinsson, Lars; Larsen, Stine Schmidt; Maddahi, Aida

    2014-01-01

    , inflammatory reactions, and microthrombosis. Additionally, a large body of evidence indicates that vascular plasticity plays an important role in SAH pathophysiology, and this review aims to summarize our current knowledge on the phenotypic changes of vascular smooth muscle cells of the cerebral vasculature...

  2. Proteomics research on muscle-invasive bladder transitional cell carcinoma

    Directory of Open Access Journals (Sweden)

    Cao Yan

    2011-06-01

    Full Text Available Abstract Background Aimed to facilitate candidate biomarkers selection and improve network-based multi-target therapy, we perform comparative proteomics research on muscle-invasive bladder transitional cell carcinoma. Laser capture microdissection was used to harvest purified muscle-invasive bladder cancer cells and normal urothelial cells from 4 paired samples. Two-dimensional liquid chromatography tandem mass spectrometry was used to identify the proteome expression profile. The differential proteins were further analyzed using bioinformatics tools and compared with the published literature. Results A total of 885/890 proteins commonly appeared in 4 paired samples. 295/337 of the 488/493 proteins that specific expressed in tumor/normal cells own gene ontology (GO cellular component annotation. Compared with the entire list of the international protein index (IPI, there are 42/45 GO terms exhibited as enriched and 9/5 exhibited as depleted, respectively. Several pathways exhibit significantly changes between cancer and normal cells, mainly including spliceosome, endocytosis, oxidative phosphorylation, etc. Finally, descriptive statistics show that the PI Distribution of candidate biomarkers have certain regularity. Conclusions The present study identified the proteome expression profile of muscle-invasive bladder cancer cells and normal urothelial cells, providing information for subcellular pattern research of cancer and offer candidate proteins for biomarker panel and network-based multi-target therapy.

  3. The Changes of Muscle Strength and Functional Activities During Aging in Male and Female Populations

    Directory of Open Access Journals (Sweden)

    Shih-Jung Cheng

    2014-12-01

    Conclusion: We noted that the muscle strength and functional activities were decreased earlier in female than male individuals. The decrease of functional activities during the aging process seems to be earlier than the decrease of muscle strength. It is important to implement functional activities training in addition to strengthening exercise to maintain functional levels of the geriatric population.

  4. Relationship between muscle strength and motor function in Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Milene F. Nunes

    2016-07-01

    Full Text Available ABSTRACT Measuring muscle strength and motor function is part of Duchenne muscular dystrophy (DMD assessment. However, the relationship between these variables is controversial. Objective To investigate the relationship between muscle strength and motor function and between these variables and age. Method Muscle strength was measured by Medical Research Council (MRC scale and motor function, by Motor Function Measure (MFM, in 40 non-ambulatory patients. Spearman tests investigated the relationships between muscle strength, motor function and age. Results Total MRC and MFM scores were strongly related to each other (r = 0.94; p 0.05. Strong and moderate relationships between partial muscle strength and motor function scores were found. Higher correlation coefficients were found between total scores and Dimensions 2 (axial/ proximal control and 3 (distal control of MFM. Conclusion Muscle strength and motor function are strongly correlated and seem to decrease proportionally in DMD.

  5. Muscle fatigue in frog semitendinosus: alterations in contractile function

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  6. Atrophy/hypertrophy cell signaling in muscles of young athletes trained with vibrational-proprioceptive stimulation.

    Science.gov (United States)

    Kern, Helmut; Pelosi, Laura; Coletto, Luisa; Musarò, Antonio; Sandri, Marco; Vogelauer, Michael; Trimmel, Lukas; Cvecka, Jan; Hamar, Dusan; Kovarik, Josef; Löfler, Stefan; Sarabon, Nejc; Protasi, Feliciano; Adami, Nicoletta; Biral, Donatella; Zampieri, Sandra; Carraro, Ugo

    2011-12-01

    To compare the effects of isokinetic (ISO-K) and vibrational-proprioceptive (VIB) trainings on muscle mass and strength. In 29 ISO-K- or VIB-trained young athletes we evaluated: force, muscle fiber morphometry, and gene expression of muscle atrophy/hypertrophy cell signaling. VIB training increased the maximal isometric unilateral leg extension force by 48·1%. ISO-K training improved the force by 24·8%. Both improvements were statistically significant (P⩿0·01). The more functional effectiveness of the VIB training in comparison with the ISO-K training was shown by the statistical significance changes only in VIB group in: rate of force development in time segment 0-50 ms (Pmuscle fibers (-3%, not significant). No neural cell adhesion molecule-positive (N-CAM(+)) and embryonic myosin heavy chain-positive (MHC-emb(+)) myofibers were detected. VIB induced a significant twofold increase (Pmuscle isoform insulin-like growth factor-1 (IGF-1) Ec mRNA. Atrogin-1 and muscle ring finger-1 (MuRF-1) did not change, but myostatin was strongly downregulated after VIB training (Pmuscle damage. Only VIB-trained group showed statistical significance increase of hypertrophy cell signaling pathways (IGF-1Ec and PGC-1α upregulation, and myostatin downregulation) leading to hypertrophy of fast twitch muscle fibers.

  7. Adult murine skeletal muscle contains cells that can differentiate into beating cardiomyocytes in vitro.

    Directory of Open Access Journals (Sweden)

    Steve O Winitsky

    2005-04-01

    Full Text Available It has long been held as scientific fact that soon after birth, cardiomyocytes cease dividing, thus explaining the limited restoration of cardiac function after a heart attack. Recent demonstrations of cardiac myocyte differentiation observed in vitro or after in vivo transplantation of adult stem cells from blood, fat, skeletal muscle, or heart have challenged this view. Analysis of these studies has been complicated by the large disparity in the magnitude of effects seen by different groups and obscured by the recently appreciated process of in vivo stem-cell fusion. We now show a novel population of nonsatellite cells in adult murine skeletal muscle that progress under standard primary cell-culture conditions to autonomously beating cardiomyocytes. Their differentiation into beating cardiomyocytes is characterized here by video microscopy, confocal-detected calcium transients, electron microscopy, immunofluorescent cardiac-specific markers, and single-cell patch recordings of cardiac action potentials. Within 2 d after tail-vein injection of these marked cells into a mouse model of acute infarction, the marked cells are visible in the heart. By 6 d they begin to differentiate without fusing to recipient cardiac cells. Three months later, the tagged cells are visible as striated heart muscle restricted to the region of the cardiac infarct.

  8. Does regulation of skeletal muscle function involve circulating microRNAs?

    Directory of Open Access Journals (Sweden)

    Wataru eAoi

    2014-02-01

    Full Text Available MicroRNAs (miRNAs are small non-coding RNAs involved in posttranscriptional gene regulation. Recently, growing evidence has shown that miRNAs are taken in by intracellular exosomes, secreted into circulation, and taken up by other cells. Circulating levels of several miRNAs are changed in diseases such as cancer, diabetes, and cardiovascular diseases; therefore, they are suggested to regulate functions of the recipient cells by modulating protein expression. Circulating miRNAs (c-miRNAs may also modulate skeletal muscle function in physiological and pathological conditions. It has been suggested that acute and chronic exercise transiently or adaptively changes the level of c-miRNAs, thus posttranscriptionally regulating proteins associated with energy metabolism, myogenesis, and angiogenesis. Circulating levels of several miRNAs that are enriched in muscle are altered in muscle disorders and may be involved in their development and progression. In addition, such c-miRNAs may be useful as biomarkers to determine various interactions between tissues and also to reflect athletic performance, physical fatigue, incidence risk, and development of diseases.

  9. Paradoxical effects of increased expression of PGC-1α on muscle mitochondrial function and insulin-stimulated muscle glucose metabolism

    Science.gov (United States)

    Choi, Cheol Soo; Befroy, Douglas E.; Codella, Roberto; Kim, Sheene; Reznick, Richard M.; Hwang, Yu-Jin; Liu, Zhen-Xiang; Lee, Hui-Young; Distefano, Alberto; Samuel, Varman T.; Zhang, Dongyan; Cline, Gary W.; Handschin, Christoph; Lin, Jiandie; Petersen, Kitt F.; Spiegelman, Bruce M.; Shulman, Gerald I.

    2008-01-01

    Peroxisome proliferator-activated receptor-γ coactivator (PGC)-1α has been shown to play critical roles in regulating mitochondria biogenesis, respiration, and muscle oxidative phenotype. Furthermore, reductions in the expression of PGC-1α in muscle have been implicated in the pathogenesis of type 2 diabetes. To determine the effect of increased muscle-specific PGC-1α expression on muscle mitochondrial function and glucose and lipid metabolism in vivo, we examined body composition, energy balance, and liver and muscle insulin sensitivity by hyperinsulinemic-euglycemic clamp studies and muscle energetics by using 31P magnetic resonance spectroscopy in transgenic mice. Increased expression of PGC-1α in muscle resulted in a 2.4-fold increase in mitochondrial density, which was associated with an ≈60% increase in the unidirectional rate of ATP synthesis. Surprisingly, there was no effect of increased muscle PGC-1α expression on whole-body energy expenditure, and PGC-1α transgenic mice were more prone to fat-induced insulin resistance because of decreased insulin-stimulated muscle glucose uptake. The reduced insulin-stimulated muscle glucose uptake could most likely be attributed to a relative increase in fatty acid delivery/triglyceride reesterfication, as reflected by increased expression of CD36, acyl-CoA:diacylglycerol acyltransferase1, and mitochondrial acyl-CoA:glycerol-sn-3-phosphate acyltransferase, that may have exceeded mitochondrial fatty acid oxidation, resulting in increased intracellular lipid accumulation and an increase in the membrane to cytosol diacylglycerol content. This, in turn, caused activation of PKCθ, decreased insulin signaling at the level of insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation, and skeletal muscle insulin resistance. PMID:19066218

  10. Muscling up damaged hearts through cell therapy

    Institute of Scientific and Technical Information of China (English)

    Chi Van Dang

    2006-01-01

    @@ Molecular and cellular processes gleaned from the most fundamental of biomedical studies are now harnessed for their potential healing properties. In the US and throughout the world, millions of patients suffer from myocardial infarction and many succumb to the morbidity and mortality of the ensuing cardiac failure, a protracted condition in need of healing. While pharmacological agents have been the mainstay intervention that ameliorates cardiac failure through increased contractility or reduction of cardiac workload, these agents do not inherently heal the wounds inflicted by poor perfusion of the affected cardiac tissue.Cell therapy, however, holds the promise of repleting the damage heart with new contractile cells that can be engineered to secrete concoctions that promote healing by recruiting new blood vessel development or angiogenesis.Such cell therapeutic promise has already been fulfilled for many decades for hematological diseases through transplantation of bone marrow stem cells, which are now more broadly implicated for their healing potential of other tissues.

  11. Adaptations in limb muscle function following pulmonary rehabilitation in patients with COPD - a review.

    Science.gov (United States)

    Nyberg, André; Carvalho, João; Bui, Kim-Ly; Saey, Didier; Maltais, François

    Even though chronic obstructive pulmonary disease (COPD) is primarily a disease of the respiratory system, limb muscle dysfunction characterized by muscle weakness, reduced muscle endurance and higher muscle fatigability, is a common secondary consequence and a major systemic manifestation of the disease. Muscle dysfunction is especially relevant in COPD because it is related to important clinical outcomes such as mortality, quality of life and exercise intolerance, independently of lung function impairment. Thus, improving muscle function is considered an important therapeutic goal in COPD management. Pulmonary rehabilitation (PR) is a multidisciplinary, evidence-based and comprehensive approach used to promote better self-management of the disease, minimize symptom burden, optimize functional status, and increase participation in activities of daily life. Exercise training, including cardiovascular and muscle exercises, is the cornerstone of PR and is considered the best available strategy to improve exercise tolerance and muscle function among patients with COPD. This paper addresses the various components of exercise training within PR used to improve limb muscle function in COPD, providing clinicians and health-care professionals with an overview and description of these various exercise modalities and of their effects on limb muscle function. Guidance and recommendations to help design optimal limb muscle training regimens for these patients are also presented. Copyright © 2016 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.

  12. 3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells.

    Directory of Open Access Journals (Sweden)

    Tong Luo

    Full Text Available The 3D geometry of individual vascular smooth muscle cells (VSMCs, which are essential for understanding the mechanical function of blood vessels, are currently not available. This paper introduces a new 3D segmentation algorithm to determine VSMC morphology and orientation.A total of 112 VSMCs from six porcine coronary arteries were used in the analysis. A 3D semi-automatic segmentation method was developed to reconstruct individual VSMCs from cell clumps as well as to extract the 3D geometry of VSMCs. A new edge blocking model was introduced to recognize cell boundary while an edge growing was developed for optimal interpolation and edge verification. The proposed methods were designed based on Region of Interest (ROI selected by user and interactive responses of limited key edges. Enhanced cell boundary features were used to construct the cell's initial boundary for further edge growing. A unified framework of morphological parameters (dimensions and orientations was proposed for the 3D volume data. Virtual phantom was designed to validate the tilt angle measurements, while other parameters extracted from 3D segmentations were compared with manual measurements to assess the accuracy of the algorithm. The length, width and thickness of VSMCs were 62.9±14.9 μm, 4.6±0.6 μm and 6.2±1.8 μm (mean±SD. In longitudinal-circumferential plane of blood vessel, VSMCs align off the circumferential direction with two mean angles of -19.4±9.3° and 10.9±4.7°, while an out-of-plane angle (i.e., radial tilt angle was found to be 8±7.6° with median as 5.7°.A 3D segmentation algorithm was developed to reconstruct individual VSMCs of blood vessel walls based on optical image stacks. The results were validated by a virtual phantom and manual measurement. The obtained 3D geometries can be utilized in mathematical models and leads a better understanding of vascular mechanical properties and function.

  13. Localization and function of ATP-sensitive potassium channels in human skeletal muscle

    DEFF Research Database (Denmark)

    Nielsen, Jens Jung; Kristensen, Michael; Hellsten, Ylva

    2003-01-01

    The present study investigated the localization of ATP-sensitive K+ (KATP) channels in human skeletal muscle and the functional importance of these channels for human muscle K+ distribution at rest and during muscle activity. Membrane fractionation based on the giant vesicle technique...

  14. Heparin inhibits human coronary artery smooth muscle cell migration.

    Science.gov (United States)

    Kohno, M; Yokokawa, K; Yasunari, K; Minami, M; Kano, H; Mandal, A K; Yoshikawa, J

    1998-09-01

    Heparin, an anticoagulant, has been shown to reduce neointimal proliferation and restenosis following vascular injury in experimental studies, but the clinical trials of heparin in coronary balloon angioplasty have been negative. The current study, therefore, examined the effect of heparin on basal or stimulated migration by serum and platelet-derived growth factor (PDGF)-BB in cultured human coronary artery smooth muscle cells (SMCs) by Boyden's chamber method. In addition, the reversibility of the heparin effect on human coronary artery SMC migration was examined. Fetal calf serum (FCS) and PDGF-BB stimulated SMC migration in a concentration-dependent manner. Heparin in moderate to high concentration (10 to 100 U/mL) exhibited concentration-related inhibition of FCS- and PDGF-BB-stimulated SMC migration; however, a low concentration (1 U/mL) of heparin had no inhibitory effects. Heparin also had weak inhibitory effects on nonstimulated SMC migration. The SMCs that were exposed to a high concentration (100 U/mL) of heparin for 6 hours were capable of migrating after a short lag period of removal of heparin from the culture medium. These SMCs also showed recovery of responses to FCS and PDGF-BB by migrating significantly greater than the nonstimulated level. Furthermore, heparin-containing medium did not contain detached cells. These results indicate that heparin inhibits human coronary artery SMC migration, especially when stimulated by FCS or PDGF-BB, and that this inhibitory effect of heparin is reversible and not simply a function of killing cells.

  15. Functional electrical stimulation to the abdominal wall muscles synchronized with the expiratory flow does not induce muscle fatigue.

    Science.gov (United States)

    Okuno, Yukako; Takahashi, Ryoichi; Sewa, Yoko; Ohse, Hirotaka; Imura, Shigeyuki; Tomita, Kazuhide

    2017-03-01

    [Purpose] Continuous electrical stimulation of abdominal wall muscles is known to induce mild muscle fatigue. However, it is not clear whether this is also true for functional electrical stimulation delivered only during the expiratory phase of breathing. This study aimed to examine whether or not intermittent electrical stimulation delivered to abdominal wall muscles induces muscle fatigue. [Subjects and Methods] The subjects were nine healthy adults. Abdominal electrical stimulation was applied for 1.5 seconds from the start of expiration and then turned off during inspiration. The electrodes were attached to both sides of the abdomen at the lower margin of the 12th rib. Abdominal electrical stimulation was delivered for 15 minutes with the subject in a seated position. Expiratory flow was measured during stimulus. Trunk flexor torque and electromyography activity were measured to evaluate abdominal muscle fatigue. [Results] The mean stimulation on/off ratio was 1:2.3. The declining rate of abdominal muscle torque was 61.1 ± 19.1% before stimulus and 56.5 ± 20.9% after stimulus, not significantly different. The declining rate of mean power frequency was 47.8 ± 11.7% before stimulus and 47.9 ± 10.2% after stimulus, not significantly different. [Conclusion] It was found that intermittent electrical stimulation to abdominal muscles synchronized with the expiratory would not induce muscle fatigue.

  16. Functional electrical stimulation to the abdominal wall muscles synchronized with the expiratory flow does not induce muscle fatigue

    Science.gov (United States)

    Okuno, Yukako; Takahashi, Ryoichi; Sewa, Yoko; Ohse, Hirotaka; Imura, Shigeyuki; Tomita, Kazuhide

    2017-01-01

    [Purpose] Continuous electrical stimulation of abdominal wall muscles is known to induce mild muscle fatigue. However, it is not clear whether this is also true for functional electrical stimulation delivered only during the expiratory phase of breathing. This study aimed to examine whether or not intermittent electrical stimulation delivered to abdominal wall muscles induces muscle fatigue. [Subjects and Methods] The subjects were nine healthy adults. Abdominal electrical stimulation was applied for 1.5 seconds from the start of expiration and then turned off during inspiration. The electrodes were attached to both sides of the abdomen at the lower margin of the 12th rib. Abdominal electrical stimulation was delivered for 15 minutes with the subject in a seated position. Expiratory flow was measured during stimulus. Trunk flexor torque and electromyography activity were measured to evaluate abdominal muscle fatigue. [Results] The mean stimulation on/off ratio was 1:2.3. The declining rate of abdominal muscle torque was 61.1 ± 19.1% before stimulus and 56.5 ± 20.9% after stimulus, not significantly different. The declining rate of mean power frequency was 47.8 ± 11.7% before stimulus and 47.9 ± 10.2% after stimulus, not significantly different. [Conclusion] It was found that intermittent electrical stimulation to abdominal muscles synchronized with the expiratory would not induce muscle fatigue. PMID:28356636

  17. Sarcomere length organization as a design for cooperative function amongst all lumbar spine muscles.

    Science.gov (United States)

    Zwambag, Derek P; Ricketts, T Alexander; Brown, Stephen H M

    2014-09-22

    The functional design of spine muscles in part dictates their role in moving, loading, and stabilizing the lumbar spine. There have been numerous studies that have examined the isolated properties of these individual muscles. Understanding how these muscles interact and work together, necessary for the prediction of muscle function, spine loading, and stability, is lacking. The objective of this study was to measure sarcomere lengths of lumbar muscles in a neutral cadaveric position and predict the sarcomere operating ranges of these muscles throughout full ranges of spine movements. Sarcomere lengths of seven lumbar muscles in each of seven cadaveric donors were measured using laser diffraction. Using published anatomical coordinate data, superior muscle attachment sites were rotated about each intervertebral joint and the total change in muscle length was used to predict sarcomere length operating ranges. The extensor muscles had short sarcomere lengths in a neutral spine posture and there were no statistically significant differences between extensor muscles. The quadratus lumborum was the only muscle with sarcomere lengths that were optimal for force production in a neutral spine position, and the psoas muscles had the longest lengths in this position. During modeled flexion the extensor, quadratus lumborum, and intertransversarii muscles lengthened so that all muscles operated in the approximate same location on the descending limb of the force-length relationship. The intrinsic properties of lumbar muscles are designed to complement each other. The extensor muscles are all designed to produce maximum force in a mid-flexed posture, and all muscles are designed to operate at similar locations of the force-length relationship at full spine flexion.

  18. Influence of different types of carbon nanotubes on muscle cell response

    Energy Technology Data Exchange (ETDEWEB)

    Fraczek-Szczypta, Aneta, E-mail: afraczek@agh.edu.pl [Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow (Poland); Menaszek, Elzbieta [Department of Cytobiology, Collegium Medicum, Jagiellonian University, Medyczna 9, 30-068 Krakow (Poland); Blazewicz, Stanislaw [Department of Biomaterials, Faculty of Materials Science and Ceramics, AGH-University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow (Poland); Adu, Jimi; Shevchenko, Ross [Pharmidex Pharmaceutical Services, 72 New Bond Street, Mayfair London, W1S 1RR (United Kingdom); Syeda, Tahmina Bahar; Misra, Anil; Alavijeh, Mohammad [School of Pharmacy and Biomolecular Sciences, Huxley Building, University of Brighton, Brighton, BN2 4GJ (United Kingdom)

    2015-01-01

    The aim of this study was to evaluate the impact of multi-walled carbon nanotubes (MWCNTs), before and after chemical surface functionalization on muscle cell response in vitro and in vivo conditions. Prior to biological tests the surface physicochemical properties of the carbon nanotubes (CNTs) deposited on a polymer membrane were investigated. To 'evaluate microstructure and structure of CNTs scanning electron microscopy (SEM) and Fourier transformation infrared spectroscopy (FTIR) were used. During in vitro study CNTs deposited on polymer membrane were contacted directly with myoblast cells, and after 7 days of culture cytotoxicity of samples was analyzed. Moreover, cell morphology in contact with CNTs was observed using SEM and fluorescence microscopy. The cytotoxicity of CNTs modified in a different way was comparable and significantly lower in comparison with pure polymer membrane. Microscopy analysis of cultured myoblasts confirms intense cell proliferation of all investigated samples with CNTs while for two kinds of CNTs myoblasts' differentiation into myotubes was observed. Histochemical reactions for the activity of enzymes such as acid phosphatase, cytochrome C oxidase, and non-specific esterase allowed the analysis of the extent of inflammation, degree of regeneration process of the muscle fibers resulting from the presence of the satellite cells and the neuromuscular junction on muscle fibers in contact with CNTs after implantation of CNTs into gluteal muscle of rat.

  19. [Non-invasive investigation of muscle function using 31P magnetic resonance spectroscopy and 1H MR imaging].

    Science.gov (United States)

    Bendahan, D; Mattei, J P; Guis, S; Kozak-Ribbens, G; Cozzone, P J

    2006-04-01

    31P MRS and 1H MRI of skeletal muscle have become major new tools allowing a complete non invasive investigation of muscle function both in the clinical setting and in basic research. The comparative analysis of normal and diseased muscle remains a major requirement to further define metabolic events surrounding muscle contraction and the metabolic anomalies underlying pathologies. Also, standardized rest-exercise-recovery protocols for the exploration of muscle metabolism by P-31 MRS in healthy volunteers as well as in patients with intolerance to exercise have been developed. The CRMBM protocol is based on a short-term intense exercise, which is very informative and well accepted by volunteers and patients. Invariant metabolic parameters have been defined to characterize the normal metabolic response to the protocol. Deviations from normality can be directly interpreted in terms of specific pathologies in some favorable cases. This protocol has been applied to more than 4,000 patients and healthy volunteers over a period of 15 years. On the other hand, MRI investigations provide anatomical and functional information from resting and exercising muscle. From a diagnostic point of view, dedicated pulse sequences can be used in order to detect and quantify muscle inflammation, fatty replacement, muscle hyper and hypotrophy. In most cases, MR techniques provide valuable information which has to be processed in conjunction with traditional invasive biochemical, electrophysiological and histoenzymological tests. P-31 MRS has proved particularly useful in the therapeutic follow-up of palliative therapies (coenzyme Q treatment of mitochondriopathies) and in family investigations. It is now an accepted diagnostic tool in the array of tests which are used to characterize muscle disorders in clinical routine. As a research tool, it will keep bringing new information on the physiopathology of muscle diseases in animal models and in humans and should play a role in the

  20. Homeotic gene function in the muscles of Drosophila larvae

    OpenAIRE

    Hooper, Joan E.

    1986-01-01

    The segmental musculature of Drosophila melanogaster larvae consists of 24-30 muscles per segment. Unique patterns of muscles are found in the three thoracic segments and the first and last abdominal segments; the remaining abdominal segments share the same pattern. Mutations in Ultrabithorax (Ubx) cause partial transformation of the muscle pattern of larval abdominal segments towards metathorax. The muscles of the thorax are not affected. In the first two abdominal segments the changes inclu...

  1. Physical and functional association of lactate dehydrogenase (LDH) with skeletal muscle mitochondria.

    Science.gov (United States)

    Elustondo, Pia A; White, Adrienne E; Hughes, Meghan E; Brebner, Karen; Pavlov, Evgeny; Kane, Daniel A

    2013-08-30

    The intracellular lactate shuttle hypothesis posits that lactate generated in the cytosol is oxidized by mitochondrial lactate dehydrogenase (LDH) of the same cell. To examine whether skeletal muscle mitochondria oxidize lactate, mitochondrial respiratory oxygen flux (JO2) was measured during the sequential addition of various substrates and cofactors onto permeabilized rat gastrocnemius muscle fibers, as well as isolated mitochondrial subpopulations. Addition of lactate did not alter JO2. However, subsequent addition of NAD(+) significantly increased JO2, and was abolished by the inhibitor of mitochondrial pyruvate transport, α-cyano-4-hydroxycinnamate. In experiments with isolated subsarcolemmal and intermyofibrillar mitochondrial subpopulations, only subsarcolemmal exhibited NAD(+)-dependent lactate oxidation. To further investigate the details of the physical association of LDH with mitochondria in muscle, immunofluorescence/confocal microscopy and immunoblotting approaches were used. LDH clearly colocalized with mitochondria in intact, as well as permeabilized fibers. LDH is likely localized inside the outer mitochondrial membrane, but not in the mitochondrial matrix. Collectively, these results suggest that extra-matrix LDH is strategically positioned within skeletal muscle fibers to functionally interact with mitochondria.

  2. Physical and Functional Association of Lactate Dehydrogenase (LDH) with Skeletal Muscle Mitochondria*

    Science.gov (United States)

    Elustondo, Pia A.; White, Adrienne E.; Hughes, Meghan E.; Brebner, Karen; Pavlov, Evgeny; Kane, Daniel A.

    2013-01-01

    The intracellular lactate shuttle hypothesis posits that lactate generated in the cytosol is oxidized by mitochondrial lactate dehydrogenase (LDH) of the same cell. To examine whether skeletal muscle mitochondria oxidize lactate, mitochondrial respiratory oxygen flux (JO2) was measured during the sequential addition of various substrates and cofactors onto permeabilized rat gastrocnemius muscle fibers, as well as isolated mitochondrial subpopulations. Addition of lactate did not alter JO2. However, subsequent addition of NAD+ significantly increased JO2, and was abolished by the inhibitor of mitochondrial pyruvate transport, α-cyano-4-hydroxycinnamate. In experiments with isolated subsarcolemmal and intermyofibrillar mitochondrial subpopulations, only subsarcolemmal exhibited NAD+-dependent lactate oxidation. To further investigate the details of the physical association of LDH with mitochondria in muscle, immunofluorescence/confocal microscopy and immunoblotting approaches were used. LDH clearly colocalized with mitochondria in intact, as well as permeabilized fibers. LDH is likely localized inside the outer mitochondrial membrane, but not in the mitochondrial matrix. Collectively, these results suggest that extra-matrix LDH is strategically positioned within skeletal muscle fibers to functionally interact with mitochondria. PMID:23873936

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

    Lifescience Database Archive (English)

    Full Text Available InP.Emb.05.AllAg.Muscle_cells dm3 Input control Embryo Muscle cells SRX110786,SRX11...0789,SRX110794,SRX110785,SRX110790 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.05.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available ALL.Emb.50.AllAg.Muscle_cells dm3 All antigens Embryo Muscle cells SRX110783,SRX110...X110785,SRX110779,SRX110790,SRX110794 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.50.AllAg.Muscle_cells.bed ...

  5. 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 ...

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

    Lifescience Database Archive (English)

    Full Text Available ALL.Emb.10.AllAg.Muscle_cells dm3 All antigens Embryo Muscle cells SRX110776,SRX110...X110790,SRX066244,SRX110778,SRX110779 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.10.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.20.AllAg.Muscle_cells dm3 RNA polymerase Embryo Muscle cells SRX110760,SRX1...X110758,SRX110765,SRX110766,SRX110769 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.20.AllAg.Muscle_cells.bed ...

  8. 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 ...

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

    Lifescience Database Archive (English)

    Full Text Available ALL.Emb.05.AllAg.Muscle_cells dm3 All antigens Embryo Muscle cells SRX110776,SRX110...X110768,SRX110763,SRX110790,SRX066244 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Emb.05.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available InP.Emb.50.AllAg.Muscle_cells dm3 Input control Embryo Muscle cells SRX110786,SRX11...0789,SRX110785,SRX110790,SRX110794 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.50.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available InP.Emb.10.AllAg.Muscle_cells dm3 Input control Embryo Muscle cells SRX110786,SRX11...0794,SRX110789,SRX110785,SRX110790 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.10.AllAg.Muscle_cells.bed ...

  12. 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 ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.10.AllAg.Muscle_cells dm3 RNA polymerase Embryo Muscle cells SRX110769,SRX1...X110763,SRX110771,SRX110768,SRX110770 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.10.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available InP.Emb.20.AllAg.Muscle_cells dm3 Input control Embryo Muscle cells SRX110789,SRX11...0794,SRX110786,SRX110790,SRX110785 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Emb.20.AllAg.Muscle_cells.bed ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.05.AllAg.Muscle_cells dm3 RNA polymerase Embryo Muscle cells SRX110762,SRX1...X110759,SRX110770,SRX110768,SRX110763 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.05.AllAg.Muscle_cells.bed ...

  16. 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 ...

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

    Lifescience Database Archive (English)

    Full Text Available Pol.Emb.50.AllAg.Muscle_cells dm3 RNA polymerase Embryo Muscle cells SRX110760,SRX1...X110765,SRX110769,SRX110766,SRX110758 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Pol.Emb.50.AllAg.Muscle_cells.bed ...

  18. Comparative Biomechanics of Thick Filaments and Thin Filaments with Functional Consequences for Muscle Contraction

    Directory of Open Access Journals (Sweden)

    Mark S. Miller

    2010-01-01

    Full Text Available The scaffold of striated muscle is predominantly comprised of myosin and actin polymers known as thick filaments and thin filaments, respectively. The roles these filaments play in muscle contraction are well known, but the extent to which variations in filament mechanical properties influence muscle function is not fully understood. Here we review information on the material properties of thick filaments, thin filaments, and their primary constituents; we also discuss ways in which mechanical properties of filaments impact muscle performance.

  19. Hydrogel-based engineered skeletal muscle grafts normalize heart function early after myocardial infarction.

    Science.gov (United States)

    Giraud, Marie-Noëlle; Ayuni, Erick; Cook, Stéphane; Siepe, Matthias; Carrel, Thierry P; Tevaearai, Hendrik T

    2008-09-01

    Tissue engineering represents an attractive approach for the treatment of congestive heart failure. The influence of the differentiation of myogenic graft for functional recovery is not defined. We engineered a biodegradable skeletal muscle graft (ESMG) tissue and investigated its functional effect after implantation on the epicardium of an infarcted heart segment. ESMGs were synthesized by mixing collagen (2 mg/mL), Matrigel (2 mg/mL), and rat skeletal muscle cells (10(6)). Qualitative and quantitative aspects of ESMGs were optimized. Two weeks following coronary ligation, the animals were randomized in three groups: ESMG glued to the epicardial surface with fibrin (ESMG, n = 7), fibrin alone (fibrin, n = 5), or sham operation (sham, n = 4). Echocardiography, histology, and immunostaining were performed 4 weeks later. A cohesive three-dimensional tissular structure formed in vitro within 1 week. Myoblasts differentiated into randomly oriented myotubes. Four weeks postimplantation, ESMGs were vascularized and invaded by granulation tissue. Mean fractional shortening (FS) was, however, significantly increased in the ESMG group as compared with preimplantation values (42 +/- 6 vs. 33 +/- 5%, P < 0.05) and reached the values of controlled noninfarcted animals (control, n = 5; 45 +/- 3%; not significant). Pre- and postimplantation FS did not change over these 4 weeks in the sham group and the fibrin-treated animals. This study showed that it is possible to improve systolic heart function following myocardial infarction through implantation of differentiated muscle fibers seeded on a gel-type scaffold despite a low rate of survival.

  20. 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

  1. High-density lipoprotein maintains skeletal muscle function by modulating cellular respiration in mice.

    Science.gov (United States)

    Lehti, Maarit; Donelan, Elizabeth; Abplanalp, William; Al-Massadi, Omar; Habegger, Kirk M; Weber, Jon; Ress, Chandler; Mansfeld, Johannes; Somvanshi, Sonal; Trivedi, Chitrang; Keuper, Michaela; Ograjsek, Teja; Striese, Cynthia; Cucuruz, Sebastian; Pfluger, Paul T; Krishna, Radhakrishna; Gordon, Scott M; Silva, R A Gangani D; Luquet, Serge; Castel, Julien; Martinez, Sarah; D'Alessio, David; Davidson, W Sean; Hofmann, Susanna M

    2013-11-26

    Abnormal glucose metabolism is a central feature of disorders with increased rates of cardiovascular disease. Low levels of high-density lipoprotein (HDL) are a key predictor for cardiovascular disease. We used genetic mouse models with increased HDL levels (apolipoprotein A-I transgenic [apoA-I tg]) and reduced HDL levels (apoA-I-deficient [apoA-I ko]) to investigate whether HDL modulates mitochondrial bioenergetics in skeletal muscle. ApoA-I ko mice exhibited fasting hyperglycemia and impaired glucose tolerance test compared with wild-type mice. Mitochondria isolated from gastrocnemius muscle of apoA-I ko mice displayed markedly blunted ATP synthesis. Endurance capacity during exercise exhaustion test was impaired in apoA-I ko mice. HDL directly enhanced glucose oxidation by increasing glycolysis and mitochondrial respiration rate in C2C12 muscle cells. ApoA-I tg mice exhibited lower fasting glucose levels, improved glucose tolerance test, increased lactate levels, reduced fat mass, associated with protection against age-induced decline of endurance capacity compared with wild-type mice. Circulating levels of fibroblast growth factor 21, a novel biomarker for mitochondrial respiratory chain deficiencies and inhibitor of white adipose lipolysis, were significantly reduced in apoA-I tg mice. Consistent with an increase in glucose utilization of skeletal muscle, genetically increased HDL and apoA-I levels in mice prevented high-fat diet-induced impairment of glucose homeostasis. In view of impaired mitochondrial function and decreased HDL levels in type 2 diabetes mellitus, our findings indicate that HDL-raising therapies may preserve muscle mitochondrial function and address key aspects of type 2 diabetes mellitus beyond cardiovascular disease.

  2. An ongoing role for structural sarcomeric components in maintaining Drosophila melanogaster muscle function and structure.

    Directory of Open Access Journals (Sweden)

    Alexander D Perkins

    Full Text Available Animal muscles must maintain their function while bearing substantial mechanical loads. How muscles withstand persistent mechanical strain is presently not well understood. The basic unit of muscle is the sarcomere, which is primarily composed of cytoskeletal proteins. We hypothesized that cytoskeletal protein turnover is required to maintain muscle function. Using the flight muscles of Drosophila melanogaster, we confirmed that the sarcomeric cytoskeleton undergoes turnover throughout adult life. To uncover which cytoskeletal components are required to maintain adult muscle function, we performed an RNAi-mediated knockdown screen targeting the entire fly cytoskeleton and associated proteins. Gene knockdown was restricted to adult flies and muscle function was analyzed with behavioural assays. Here we analyze the results of that screen and characterize the specific muscle maintenance role for several hits. The screen identified 46 genes required for muscle maintenance: 40 of which had no previously known role in this process. Bioinformatic analysis highlighted the structural sarcomeric proteins as a candidate group for further analysis. Detailed confocal and electron microscopic analysis showed that while muscle architecture was maintained after candidate gene knockdown, sarcomere length was disrupted. Specifically, we found that ongoing synthesis and turnover of the key sarcomere structural components Projectin, Myosin and Actin are required to maintain correct sarcomere length and thin filament length. Our results provide in vivo evidence of adult muscle protein turnover and uncover specific functional defects associated with reduced expression of a subset of cytoskeletal proteins in the adult animal.

  3. Effects of aging on muscle mechanical function and muscle fiber morphology during short-term immobilization and subsequent retraining

    DEFF Research Database (Denmark)

    Hvid, Lars; Aagaard, Per; Justesen, Lene

    2010-01-01

    (i.e., rate of force development, impulse) than YM (∼ 20-37 vs. ∼ 13-16%; P ... mechanical function (e.g., maximal strength and rapid force capacity) and muscle fiber morphology in 9 old (OM: 67.3 ± 1.3 yr) and 11 young healthy men (YM: 24.4 ± 0.5 yr) with comparable levels of physical activity. Following immobilization, OM demonstrated markedly larger decreases in rapid force capacity...... function and muscle fiber area in YM, whereas OM showed an attenuated recovery in muscle fiber area and rapid force capacity (tendency). Changes in maximal isometric and dynamic muscle strength were similar between OM and YM. In conclusion, the present data reveal that OM may be more susceptible...

  4. Functions of the subregions of the supraspinatus muscle.

    Science.gov (United States)

    Yuri, Takuma; Kuwahara, Yoshiki; Fujii, Hiromi; Kiyoshige, Yoshiro

    2017-04-01

    The aim of this study was to investigate the functions of the six subregions of the supraspinatus muscle (SSP) determined by Kim et al. in Clin Anat 2007;20:648-655, using real-time tissue elastography (RTE). Twelve young male volunteers participated. The muscular hardness of the SSP was measured at rest and with contraction of the MMT3 in internal, neutral and external rotations. The SSP was functionally divided into five groups on the basis of the RTE results. These functional areas were roughly classified into three property groups: the anterior-superficial, anterior-middle, and anterior-deep subregions, which produce contractile force for abduction; the posterior-deep subregion, which produces contractile force for external rotation; and the posterior-superficial and posterior-middle subregions, which maintain tension. RTE was appropriate for measuring the functions of these muscular subregions. Clin. Anat. 30:347-351, 2017. © 2017 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists. © 2017 The Authors Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

  5. MeCP2 Affects Skeletal Muscle Growth and Morphology through Non Cell-Autonomous Mechanisms.

    Directory of Open Access Journals (Sweden)

    Valentina Conti

    Full Text Available Rett syndrome (RTT is an autism spectrum disorder mainly caused by mutations in the X-linked MECP2 gene and affecting roughly 1 out of 10.000 born girls. Symptoms range in severity and include stereotypical movement, lack of spoken language, seizures, ataxia and severe intellectual disability. Notably, muscle tone is generally abnormal in RTT girls and women and the Mecp2-null mouse model constitutively reflects this disease feature. We hypothesized that MeCP2 in muscle might physiologically contribute to its development and/or homeostasis, and conversely its defects in RTT might alter the tissue integrity or function. We show here that a disorganized architecture, with hypotrophic fibres and tissue fibrosis, characterizes skeletal muscles retrieved from Mecp2-null mice. Alterations of the IGF-1/Akt/mTOR pathway accompany the muscle phenotype. A conditional mouse model selectively depleted of Mecp2 in skeletal muscles is characterized by healthy muscles that are morphologically and molecularly indistinguishable from those of wild-type mice raising the possibility that hypotonia in RTT is mainly, if not exclusively, mediated by non-cell autonomous effects. Our results suggest that defects in paracrine/endocrine signaling and, in particular, in the GH/IGF axis appear as the major cause of the observed muscular defects. Remarkably, this is the first study describing the selective deletion of Mecp2 outside the brain. Similar future studies will permit to unambiguously define the direct impact of MeCP2 on tissue dysfunctions.

  6. MeCP2 Affects Skeletal Muscle Growth and Morphology through Non Cell-Autonomous Mechanisms.

    Science.gov (United States)

    Conti, Valentina; Gandaglia, Anna; Galli, Francesco; Tirone, Mario; Bellini, Elisa; Campana, Lara; Kilstrup-Nielsen, Charlotte; Rovere-Querini, Patrizia; Brunelli, Silvia; Landsberger, Nicoletta

    2015-01-01

    Rett syndrome (RTT) is an autism spectrum disorder mainly caused by mutations in the X-linked MECP2 gene and affecting roughly 1 out of 10.000 born girls. Symptoms range in severity and include stereotypical movement, lack of spoken language, seizures, ataxia and severe intellectual disability. Notably, muscle tone is generally abnormal in RTT girls and women and the Mecp2-null mouse model constitutively reflects this disease feature. We hypothesized that MeCP2 in muscle might physiologically contribute to its development and/or homeostasis, and conversely its defects in RTT might alter the tissue integrity or function. We show here that a disorganized architecture, with hypotrophic fibres and tissue fibrosis, characterizes skeletal muscles retrieved from Mecp2-null mice. Alterations of the IGF-1/Akt/mTOR pathway accompany the muscle phenotype. A conditional mouse model selectively depleted of Mecp2 in skeletal muscles is characterized by healthy muscles that are morphologically and molecularly indistinguishable from those of wild-type mice raising the possibility that hypotonia in RTT is mainly, if not exclusively, mediated by non-cell autonomous effects. Our results suggest that defects in paracrine/endocrine signaling and, in particular, in the GH/IGF axis appear as the major cause of the observed muscular defects. Remarkably, this is the first study describing the selective deletion of Mecp2 outside the brain. Similar future studies will permit to unambiguously define the direct impact of MeCP2 on tissue dysfunctions.

  7. Functional and Genetic Analysis of Plectin in Skin and Muscle.

    Science.gov (United States)

    Rezniczek, Günther A; Winter, Lilli; Walko, Gernot; Wiche, Gerhard

    2016-01-01

    Plectin is a large cytoskeletal linker protein with a multitude of functions affecting various cellular processes. It is expressed as several different isoforms from a highly complex gene. Both, this transcript diversity (mainly caused by short 5'-sequences contained in alternative first exons) and the size (>500 kDa) of the resulting proteins, present considerable challenges to plectin researchers. In this chapter, we will consider these problems and offer advice on how to tackle them best. As plectin has been studied most extensively in skin and muscle, we will focus on these types of tissues and describe some selected methods in detail. Foremost, however, we aim to give the readers some good pointers to available tools and into the existing literature.

  8. Disruption of ATP-sensitive potassium channel function in skeletal muscles promotes production and secretion of musclin

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, Ana, E-mail: ana-sierra@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Subbotina, Ekaterina, E-mail: ekaterina-subbotina@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Zhu, Zhiyong, E-mail: zhiyong-zhu@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Gao, Zhan, E-mail: zhan-gao@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Koganti, Siva Rama Krishna, E-mail: sivaramakrishna.koganti@ttuhc.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Coetzee, William A., E-mail: william.coetzee@nyumc.org [Department of Pediatrics, NYU School of Medicine, New York, NY 10016 (United States); Goldhamer, David J., E-mail: david.goldhamer@uconn.edu [Center for Regenerative Biology, Department of Molecular and Cell Biology, Advanced Technology Laboratory, University of Connecticut, 1392 Storrs Road Unit 4243, Storrs, Connecticut 06269 (United States); Hodgson-Zingman, Denice M., E-mail: denice-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Zingman, Leonid V., E-mail: leonid-zingman@uiowa.edu [Department of Internal Medicine, University of Iowa, Carver College of Medicine, Iowa City, IA 52242 (United States); Fraternal Order of Eagles Diabetes Research Center, Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Veterans Affairs, Medical Center, Iowa City, IA 52242 (United States)

    2016-02-26

    Sarcolemmal ATP-sensitive potassium (K{sub ATP}) channels control skeletal muscle energy use through their ability to adjust membrane excitability and related cell functions in accordance with cellular metabolic status. Mice with disrupted skeletal muscle K{sub ATP} channels exhibit reduced adipocyte size and increased fatty acid release into the circulation. As yet, the molecular mechanisms underlying this link between skeletal muscle K{sub ATP} channel function and adipose mobilization have not been established. Here, we demonstrate that skeletal muscle-specific disruption of K{sub ATP} channel function in transgenic (TG) mice promotes production and secretion of musclin. Musclin is a myokine with high homology to atrial natriuretic peptide (ANP) that enhances ANP signaling by competing for elimination. Augmented musclin production in TG mice is driven by a molecular cascade resulting in enhanced acetylation and nuclear exclusion of the transcription factor forkhead box O1 (FOXO1) – an inhibitor of transcription of the musclin encoding gene. Musclin production/secretion in TG is paired with increased mobilization of fatty acids and a clear trend toward increased circulating ANP, an activator of lipolysis. These data establish K{sub ATP} channel-dependent musclin production as a potential mechanistic link coupling “local” skeletal muscle energy consumption with mobilization of bodily resources from fat. Understanding such mechanisms is an important step toward designing interventions to manage metabolic disorders including those related to excess body fat and associated co-morbidities. - Highlights: • ATP-sensitive K{sup +} channels regulate musclin production by skeletal muscles. • Lipolytic ANP signaling is promoted by augmented skeletal muscle musclin production. • Skeletal muscle musclin transcription is promoted by a CaMKII/HDAC/FOXO1 pathway. • Musclin links adipose mobilization to energy use in K{sub ATP} channel deficient skeletal muscle.

  9. Systemic Inflammation in Duchenne Muscular Dystrophy: Association with Muscle Function and Nutritional Status

    Directory of Open Access Journals (Sweden)

    Oriana del Rocío Cruz-Guzmán

    2015-01-01

    Full Text Available Inflammation described in patients with Duchenne muscular dystrophy (DMD may be related to loss of muscle function or to obesity. It is unknown if circulating proinflammatory cytokines (IL-6, IL-1, and TNF-α levels are associated with muscle function. The purpose was to evaluate whether an association exists between systemic inflammation with muscle function and nutritional status in DMD patients. In 66 DMD patients without corticosteroid treatment, the following were evaluated in serum: cytokines (IL-1, IL-6, and TNF-α, C-reactive protein (CRP, leptin, adiponectin, and creatine kinase (CK. Muscle function was evaluated using Vignos Scale. Patients with better muscle function had the highest concentration of CK, IL-1, and TNF-α compared with less muscle function. No differences in IL-6 and adiponectin concentration were identified among groups with different levels of muscle function. Also, no differences were observed in the concentration of cytokines among groups with different nutritional status levels (underweight, normal weight, and overweight/obese. However, CRP and leptin were increased in the obese group compared with normal and underweight subjects. Systemic inflammation is increased in patients with better muscle function and decreases in DMD patients with poorer muscle function; nevertheless, systemic inflammation is similar among different levels of nutritional status in DMD patients.

  10. Systemic Inflammation in Duchenne Muscular Dystrophy: Association with Muscle Function and Nutritional Status

    Science.gov (United States)

    Cruz-Guzmán, Oriana del Rocío; Rodríguez-Cruz, Maricela; Escobar Cedillo, Rosa Elena

    2015-01-01

    Inflammation described in patients with Duchenne muscular dystrophy (DMD) may be related to loss of muscle function or to obesity. It is unknown if circulating proinflammatory cytokines (IL-6, IL-1, and TNF-α) levels are associated with muscle function. The purpose was to evaluate whether an association exists between systemic inflammation with muscle function and nutritional status in DMD patients. In 66 DMD patients without corticosteroid treatment, the following were evaluated in serum: cytokines (IL-1, IL-6, and TNF-α), C-reactive protein (CRP), leptin, adiponectin, and creatine kinase (CK). Muscle function was evaluated using Vignos Scale. Patients with better muscle function had the highest concentration of CK, IL-1, and TNF-α compared with less muscle function. No differences in IL-6 and adiponectin concentration were identified among groups with different levels of muscle function. Also, no differences were observed in the concentration of cytokines among groups with different nutritional status levels (underweight, normal weight, and overweight/obese). However, CRP and leptin were increased in the obese group compared with normal and underweight subjects. Systemic inflammation is increased in patients with better muscle function and decreases in DMD patients with poorer muscle function; nevertheless, systemic inflammation is similar among different levels of nutritional status in DMD patients. PMID:26380303

  11. Effect of strength training on muscle function in elderly hospitalized patients

    DEFF Research Database (Denmark)

    Suetta, C; Magnusson, S P; Beyer, N

    2007-01-01

    to induce muscle hypertrophy and increase muscle strength and functional performance in frail elderly individuals. Furthermore, there is increasing evidence that strength training is an effective method to restore muscle function in post-operative patients and in patients with chronic diseases. Despite this......Immobilization due to hospitalization and major surgery leads to an increased risk of morbidity, disability and a decline in muscle function especially in frail elderly individuals. In fact, many elderly patients fail to regain their level of function and self-care before admission to hospital....... Given that reduced lower limb muscle strength and loss of skeletal muscle mass (i.e. sarcopenia) have been associated with functional impairments and disability with aging, attempts to counteract this process seem highly relevant. In recent years, strength training has emerged as an effective method...

  12. Light- and electron microscopical studies of interstitial cells of Cajal and muscle cells at the submucosal border of human colon

    DEFF Research Database (Denmark)

    Rumessen, J J; Peters, S; Thuneberg, L

    1993-01-01

    It has been suggested that interstitial cells of Cajal (ICC) at the submucosal border of the colonic circular muscle are pacemaker cells. We studied smooth muscle cells and ICC at the submucosal surface of the circular muscle layer of the normal human colon....

  13. Age-Associated Methylation Suppresses SPRY1, Leading to a Failure of Re-quiescence and Loss of the Reserve Stem Cell Pool in Elderly Muscle

    Directory of Open Access Journals (Sweden)

    Anne Bigot

    2015-11-01

    Full Text Available The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated methylation in humans inhibits the replenishment of the muscle stem cell pool, contributing to a decreased regenerative response in old age. We further show that aging does not affect muscle stem cell senescence in humans.

  14. Age-Associated Methylation Suppresses SPRY1, Leading to a Failure of Re-quiescence and Loss of the Reserve Stem Cell Pool in Elderly Muscle.

    Science.gov (United States)

    Bigot, Anne; Duddy, William J; Ouandaogo, Zamalou G; Negroni, Elisa; Mariot, Virginie; Ghimbovschi, Svetlana; Harmon, Brennan; Wielgosik, Aurore; Loiseau, Camille; Devaney, Joe; Dumonceaux, Julie; Butler-Browne, Gillian; Mouly, Vincent; Duguez, Stéphanie

    2015-11-10

    The molecular mechanisms by which aging affects stem cell number and function are poorly understood. Murine data have implicated cellular senescence in the loss of muscle stem cells with aging. Here, using human cells and by carrying out experiments within a strictly pre-senescent division count, we demonstrate an impaired capacity for stem cell self-renewal in elderly muscle. We link aging to an increased methylation of the SPRY1 gene, a known regulator of muscle stem cell quiescence. Replenishment of the reserve cell pool was modulated experimentally by demethylation or siRNA knockdown of SPRY1. We propose that suppression of SPRY1 by age-associated methylation in humans inhibits the replenishment of the muscle stem cell pool, contributing to a decreased regenerative response in old age. We further show that aging does not affect muscle stem cell senescence in humans.

  15. Systemic down-regulation of delta-9 desaturase promotes muscle oxidative metabolism and accelerates muscle function recovery following nerve injury.

    Directory of Open Access Journals (Sweden)

    Ghulam Hussain

    Full Text Available The progressive deterioration of the neuromuscular axis is typically observed in degenerative conditions of the lower motor neurons, such as amyotrophic lateral sclerosis (ALS. Neurodegeneration in this disease is associated with systemic metabolic perturbations, including hypermetabolism and dyslipidemia. Our previous gene profiling studies on ALS muscle revealed down-regulation of delta-9 desaturase, or SCD1, which is the rate-limiting enzyme in the synthesis of monounsaturated fatty acids. Interestingly, knocking out SCD1 gene is known to induce hypermetabolism and stimulate fatty acid beta-oxidation. Here we investigated whether SCD1 deficiency can affect muscle function and its restoration in response to injury. The genetic ablation of SCD1 was not detrimental per se to muscle function. On the contrary, muscles in SCD1 knockout mice shifted toward a more oxidative metabolism, and enhanced the expression of synaptic genes. Repressing SCD1 expression or reducing SCD-dependent enzymatic activity accelerated the recovery of muscle function after inducing sciatic nerve crush. Overall, these findings provide evidence for a new role of SCD1 in modulating the restorative potential of skeletal muscles.

  16. Metabolic Effects of Insulin and IGFs on Gilthead Sea Bream (Sparus aurata) Muscle Cells

    Science.gov (United States)

    Montserrat, Núria; Capilla, Encarnación; Navarro, Isabel; Gutiérrez, Joaquim

    2012-01-01

    Primary cultures of gilthead sea bream myocytes were performed in order to examine the relative metabolic function of insulin compared with IGF-I and IGF-II (insulin-like growth factors, IGFs) at different stages in the cell culture. In these cells, the in vitro effects of insulin and IGFs on 2-deoxyglucose (2-DG) and l-alanine uptake were studied in both myocytes (day 4) and small myotubes (day 9). 2-DG uptake in gilthead sea bream muscle cells was increased in the presence of insulin and IGFs in a time dependent manner and along with muscle cell differentiation. On the contrary, l-alanine uptake was also stimulated by insulin and IGFs but showed an inverse pattern, being the uptake higher in small myocytes than in large myotubes. The results of preincubation with inhibitors (PD-98059, wortmannin, and cytochalasin B) on 2-DG uptake indicated that insulin and IGFs stimulate glucose uptake through the same mechanisms, and evidenced that mitogenesis activator protein kinase (MAPK) and PI3K–Akt transduction pathways mediate the metabolic function of these peptides. In the same way, we observed that GLUT4 protein synthesis was stimulated in the presence of insulin and IGFs in gilthead sea bream muscle cells in a different manner at days 4 or 9 of the culture. In summary we describe here, for the first time, the effects of insulin and IGFs on 2-DG and l-alanine uptake in primary culture of gilthead sea bream muscle cells. We show that both MAPK and PI3K–Akt transduction pathways are needed in order to control insulin and IGFs actions in these cells. Moreover, changes in glucose uptake can be explained by the action of the GLUT4 transporter, which is stimulated in the presence of insulin and IGFs throughout the cell culture. PMID:22654873

  17. MicroRNAs in skeletal muscle: their role and regulation in development, disease and function.

    Science.gov (United States)

    Güller, Isabelle; Russell, Aaron P

    2010-11-01

    Maintaining skeletal muscle function throughout the lifespan is a prerequisite for good health and independent living. For skeletal muscle to consistently function at optimal levels, the efficient activation of processes that regulate muscle development, growth, regeneration and metabolism is required. Numerous conditions including neuromuscular disorders, physical inactivity, chronic disease and ageing are associated with perturbations in skeletal muscle function. A loss or reduction in skeletal muscle function often leads to increased morbidity and mortality either directly, or indirectly, via the development of secondary diseases such as diabetes, obesity, cardiovascular and respiratory disease. Identifying mechanisms which influence the processes regulating skeletal muscle function is a key priority. The discovery of microRNAs (miRNAs) provides a new avenue that will extend our knowledge of factors controlling skeletal muscle function. miRNAs may also improve our understanding and application of current therapeutic approaches as well as enable the identification of new therapeutic strategies and targets aimed at maintaining and/or improving skeletal muscle health. This review brings together the latest developments in skeletal muscle miRNA biology and focuses on their role and regulation under physiological and patho-physiological conditions with an emphasis on: myogenesis, hypertrophy, atrophy and regeneration; exercise and nutrition; muscle disease, ageing, diabetes and obesity.

  18. Differential regulation of the histone chaperone HIRA during muscle cell differentiation by a phosphorylation switch.

    Science.gov (United States)

    Yang, Jae-Hyun; Song, Tae-Yang; Jo, Chanhee; Park, Jinyoung; Lee, Han-Young; Song, Ilang; Hong, Suji; Jung, Kwan Young; Kim, Jaehoon; Han, Jeung-Whan; Youn, Hong-Duk; Cho, Eun-Jung

    2016-08-12

    Replication-independent incorporation of variant histone H3.3 has a profound impact on chromatin function and numerous cellular processes, including the differentiation of muscle cells. The histone chaperone HIRA and H3.3 have essential roles in MyoD regulation during myoblast differentiation. However, the precise mechanism that determines the onset of H3.3 deposition in response to differentiation signals is unclear. Here we show that HIRA is phosphorylated by Akt kinase, an important signaling modulator in muscle cells. By generating a phosphospecific antibody, we found that a significant amount of HIRA was phosphorylated in myoblasts. The phosphorylation level of HIRA and the occupancy of phosphorylated protein on muscle genes gradually decreased during cellular differentiation. Remarkably, the forced expression of the phosphomimic form of HIRA resulted in reduced H3.3 deposition and suppressed the activation of muscle genes in myotubes. Our data show that HIRA phosphorylation limits the expression of myogenic genes, while the dephosphorylation of HIRA is required for proficient H3.3 deposition and gene activation, demonstrating that the phosphorylation switch is exploited to modulate HIRA/H3.3-mediated muscle gene regulation during myogenesis.

  19. Impaired muscle force production and higher fatigability in a mouse model of sickle cell disease.

    Science.gov (United States)

    Chatel, Benjamin; Hourdé, Christophe; Gondin, Julien; Fouré, Alexandre; Le Fur, Yann; Vilmen, Christophe; Bernard, Monique; Messonnier, Laurent A; Bendahan, David

    2017-03-01

    Skeletal muscle function has been scarcely investigated in sickle cell disease (SCD) so that the corresponding impact of sickle hemoglobin is still a matter of debate. The purpose of this study was to investigate muscle force production and fatigability in SCD and to identify whether exercise intensity could have a modulatory effect. Ten homozygous sickle cell (HbSS), ten control (HbAA) and ten heterozygous (HbAS) mice were submitted to two stimulation protocols (moderate and intense) to assess force production and fatigability. We showed that specific maximal tetanic force was lower in HbSS mice as compared to other groups. At the onset of the stimulation period, peak force was reduced in HbSS and HbAS mice as compared to HbAA mice. Contrary to the moderate protocol, the intense stimulation protocol was associated with a larger decrease in peak force and rate of force development in HbSS mice as compared to HbAA and HbAS mice. These findings provide in vivo evidence of impaired muscle force production and resistance to fatigue in SCD. These changes are independent of muscle mass. Moreover, SCD is associated with muscle fatigability when exercise intensity is high.

  20. Celastrol Protects against Antimycin A-Induced Insulin Resistance in Human Skeletal Muscle Cells

    Directory of Open Access Journals (Sweden)

    Mohamad Hafizi Abu Bakar

    2015-05-01

    Full Text Available Mitochondrial dysfunction and inflammation are widely accepted as key hallmarks of obesity-induced skeletal muscle insulin resistance. The aim of the present study was to evaluate the functional roles of an anti-inflammatory compound, celastrol, in mitochondrial dysfunction and insulin resistance induced by antimycin A (AMA in human skeletal muscle cells. We found that celastrol treatment improved insulin-stimulated glucose uptake activity of AMA-treated cells, apparently via PI3K/Akt pathways, with significant enhancement of mitochondrial activities. Furthermore, celastrol prevented increased levels of cellular oxidative damage where the production of several pro-inflammatory cytokines in cultures cells was greatly reduced. Celastrol significantly increased protein phosphorylation of insulin signaling cascades with amplified expression of AMPK protein and attenuated NF-κB and PKC θ activation in human skeletal muscle treated with AMA. The improvement of insulin signaling pathways by celastrol was also accompanied by augmented GLUT4 protein expression. Taken together, these results suggest that celastrol may be advocated for use as a potential therapeutic molecule to protect against mitochondrial dysfunction-induced insulin resistance in human skeletal muscle cells.