Science.gov

Sample records for heart muscle cells

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

    PubMed

    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.

  2. Cat heart muscle in vitro. I. Cell volumes and intracellular concentrations in papillary muscle.

    PubMed

    PAGE, E; SOLOMON, A K

    1960-11-01

    Methods have been developed for the simultaneous determination of total water, inulin space, and K and Na content in muscles of 0.5 to 10 mg. wet weight. These methods have been used to define steady state conditions with respect to intracellular K concentration in papillary muscles from cat hearts perfused and contracting isometrically at 27-28 degrees C. and at 37-38 degrees C. Cell volumes and intracellular ionic concentrations have been followed as a function of the external K concentration and compared with values predicted on the basis of electroneutrality and osmotic equilibrium.

  3. Loss of Notch3 Signaling in Vascular Smooth Muscle Cells Promotes Severe Heart Failure Upon Hypertension.

    PubMed

    Ragot, Hélène; Monfort, Astrid; Baudet, Mathilde; Azibani, Fériel; Fazal, Loubina; Merval, Régine; Polidano, Evelyne; Cohen-Solal, Alain; Delcayre, Claude; Vodovar, Nicolas; Chatziantoniou, Christos; Samuel, Jane-Lise

    2016-08-01

    Hypertension, which is a risk factor of heart failure, provokes adaptive changes at the vasculature and cardiac levels. Notch3 signaling plays an important role in resistance arteries by controlling the maturation of vascular smooth muscle cells. Notch3 deletion is protective in pulmonary hypertension while deleterious in arterial hypertension. Although this latter phenotype was attributed to renal and cardiac alterations, the underlying mechanisms remained unknown. To investigate the role of Notch3 signaling in the cardiac adaptation to hypertension, we used mice with either constitutive Notch3 or smooth muscle cell-specific conditional RBPJκ knockout. At baseline, both genotypes exhibited a cardiac arteriolar rarefaction associated with oxidative stress. In response to angiotensin II-induced hypertension, the heart of Notch3 knockout and SM-RBPJκ knockout mice did not adapt to pressure overload and developed heart failure, which could lead to an early and fatal acute decompensation of heart failure. This cardiac maladaptation was characterized by an absence of media hypertrophy of the media arteries, the transition of smooth muscle cells toward a synthetic phenotype, and an alteration of angiogenic pathways. A subset of mice exhibited an early fatal acute decompensated heart failure, in which the same alterations were observed, although in a more rapid timeframe. Altogether, these observations indicate that Notch3 plays a major role in coronary adaptation to pressure overload. These data also show that the hypertrophy of coronary arterial media on pressure overload is mandatory to initially maintain a normal cardiac function and is regulated by the Notch3/RBPJκ pathway. PMID:27296994

  4. Cat Heart Muscle in Vitro

    PubMed Central

    Page, Ernest; Solomon, A. K.

    1960-01-01

    Methods have been developed for the simultaneous determination of total water, inulin space, and K and Na content in muscles of 0.5 to 10 mg. wet weight. These methods have been used to define steady state conditions with respect to intracellular K concentration in papillary muscles from cat hearts perfused and contracting isometrically at 27–28°C. and at 37–38°C. Cell volumes and intracellular ionic concentrations have been followed as a function of the external K concentration and compared with values predicted on the basis of electroneutrality and osmotic equilibrium. PMID:13732016

  5. miRNA-146a induces vascular smooth muscle cell apoptosis in a rat model of coronary heart disease via NF-κB pathway.

    PubMed

    Wu, Z W; Liu, Y F; Wang, S; Li, B

    2015-12-29

    The aim of this study was to investigate the role of miRNA-146a in modulating the function of vascular smooth muscle cells in a rat model of coronary heart disease. Vascular smooth muscle cells were isolated and cultured from the rat coronary heart disease model and normal rats (controls). miRNA-146a levels were measured in vascular smooth muscle cells obtained from rats with coronary heart disease and control rats. The proliferation, growth, apoptosis, and activation of the NF-κB pathway in the vascular smooth muscle cells were detected using the MTT assay and flow cytometry, respectively. The role of the NF-κB pathway in modulating the apoptosis of vascular smooth muscle cells was investigated by measuring the reactivity of the cells to an NF-κB pathway inhibitor (TPCA-1). Vascular smooth muscle cells from the disease model exhibited higher levels of miRNA-146a than that by the normal controls (P = 0.0024). The vascular smooth muscle cells obtained from rats with coronary heart disease showed decreased proliferation and growth and increased apoptosis. miRNA-146a overexpression elevated the rate of cell apoptosis. The NF-κB pathway was activated in vascular smooth muscle cells obtained from rats with coronary heart disease. Inhibition of the NF- κB pathway significantly decreased the rate of vascular smooth muscle cell apoptosis in coronary heart disease rats (P = 0.0038). In conclusion, miRNA- 146a was found to induce vascular smooth muscle cell apoptosis in rats with coronary heart disease via the activation of the NF-κB signal pathway.

  6. Expression of nuclear factor of activated T cells (NFAT) and downstream muscle-specific proteins in ground squirrel skeletal and heart muscle during hibernation.

    PubMed

    Zhang, Yichi; Storey, Kenneth B

    2016-01-01

    The thirteen-lined ground squirrel (Ictidomys tridecemlineatus) undergoes remarkable adaptive changes during hibernation. Interestingly, skeletal muscle remodelling occurs during the torpor-arousal cycle of hibernation to prevent net muscle loss despite inactivity. Reversible cardiomyocyte hypertrophy occurs in cardiac muscle, allowing the heart to preserve cardiac output during hibernation, while avoiding chronic maladaptive hypertrophy post-hibernation. We propose that calcium signalling proteins [calcineurin (Cn), calmodulin (CaM), and calpain], the nuclear factor of activated T cell (NFAT) family of transcription factors, and the NFAT targets myoferlin and myomaker contribute significantly to adaptations taking place in skeletal and cardiac muscle during hibernation. Protein-level analyses were performed over several conditions: euthermic room temperature (ER), euthermic cold room (EC), entrance into (EN), early (ET), and late torpor (LT) time points, in addition to early (EA), interbout (IA), and late arousal (LA) time points using immunoblotting and DNA-protein interaction (DPI) enzyme-linked immunosorbent assay (ELISAs). In skeletal and cardiac muscle, NFATc2 protein levels were elevated during torpor. NFATc4 increased throughout the torpor-arousal cycle in both tissues, and NFATc1 showed this trend in cardiac muscle only. NFATc3 showed an elevation in DNA-binding activity but not expression during torpor. Myoferlin protein levels dramatically increased during torpor in both skeletal and cardiac muscle. Myomaker levels also increased significantly in cardiac muscle during torpor. Cardiac Cn levels remained stable, whereas CaM and calpain decreased throughout the torpor-arousal cycle. Activation and/or upregulation of NFATc2, c3, myoferlin, and myomaker at torpor could be part of a stress-response mechanism to preserve skeletal muscle mass, whereas CaM and calpain appear to initiate the rapid reversal of cardiac hypertrophy during arousal through

  7. From hair to heart: nestin-expressing hair-follicle-associated pluripotent (HAP) stem cells differentiate to beating cardiac muscle cells.

    PubMed

    Yashiro, Masateru; Mii, Sumiyuki; Aki, Ryoichi; Hamada, Yuko; Arakawa, Nobuko; Kawahara, Katsumasa; Hoffman, Robert M; Amoh, Yasuyuki

    2015-01-01

    We have previously demonstrated that the neural stem-cell marker nestin is expressed in hair follicle stem cells located in the bulge area which are termed hair-follicle-associated pluripotent (HAP) stem cells. HAP stem cells from mouse and human could form spheres in culture, termed hair spheres, which are keratin 15-negative and CD34-positive and could differentiate to neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. Subsequently, we demonstrated that nestin-expressing stem cells could effect nerve and spinal cord regeneration in mouse models. In the present study, we demonstrated that HAP stem cells differentiated to beating cardiac muscle cells. We separated the mouse vibrissa hair follicle into 3 parts (upper, middle, and lower), and suspended each part separately in DMEM containing 10% FBS. All three parts of hair follicle differentiated to beating cardiac muscle cells as well as neurons, glial cells, keratinocytes and smooth muscle cells. The differentiation potential to cardiac muscle is greatest in the upper part of the follicle. The beat rate of the cardiac muscle cells was stimulated by isoproterenol and inhibited by propanolol. HAP stem cells have potential for regenerative medicine for heart disease as well as nerve and spinal cord repair.

  8. Myosin binding protein-C activates thin filaments and inhibits thick filaments in heart muscle cells.

    PubMed

    Kampourakis, Thomas; Yan, Ziqian; Gautel, Mathias; Sun, Yin-Biao; Irving, Malcolm

    2014-12-30

    Myosin binding protein-C (MyBP-C) is a key regulatory protein in heart muscle, and mutations in the MYBPC3 gene are frequently associated with cardiomyopathy. However, the mechanism of action of MyBP-C remains poorly understood, and both activating and inhibitory effects of MyBP-C on contractility have been reported. To clarify the function of the regulatory N-terminal domains of MyBP-C, we determined their effects on the structure of thick (myosin-containing) and thin (actin-containing) filaments in intact sarcomeres of heart muscle. We used fluorescent probes on troponin C in the thin filaments and on myosin regulatory light chain in the thick filaments to monitor structural changes associated with activation of demembranated trabeculae from rat ventricle by the C1mC2 region of rat MyBP-C. C1mC2 induced larger structural changes in thin filaments than calcium activation, and these were still present when active force was blocked with blebbistatin, showing that C1mC2 directly activates the thin filaments. In contrast, structural changes in thick filaments induced by C1mC2 were smaller than those associated with calcium activation and were abolished or reversed by blebbistatin. Low concentrations of C1mC2 did not affect resting force but increased calcium sensitivity and reduced cooperativity of force and structural changes in both thin and thick filaments. These results show that the N-terminal region of MyBP-C stabilizes the ON state of thin filaments and the OFF state of thick filaments and lead to a novel hypothesis for the physiological role of MyBP-C in the regulation of cardiac contractility.

  9. Voltage-Independent Calcium Release in Heart Muscle

    NASA Astrophysics Data System (ADS)

    Niggli, Ernst; Lederer, W. Jonathan

    1990-10-01

    The Ca2+ that activates contraction in heart muscle is regulated as in skeletal muscle by processes that depend on voltage and intracellular Ca2+ and involve a positive feedback system. How the initial electrical signal is amplified in heart muscle has remained controversial, however. Analogous protein structures from skeletal muscle and heart muscle have been identified physiologically and sequenced; these include the Ca2+ channel of the sarcolemma and the Ca2+ release channel of the sarcoplasmic reticulum. Although the parallels found in cardiac and skeletal muscles have provoked valuable experiments in both tissues, separation of the effects of voltage and intracellular Ca2+ on sarcoplasmic reticulum Ca2+ release in heart muscle has been imperfect. With the use of caged Ca2+ and flash photolysis in voltage-clamped heart myocytes, effects of membrane potential in heart muscle cells on Ca2+ release from intracellular stores have been studied. Unlike the response in skeletal muscle, voltage across the sarcolemma of heart muscle does not affect the release of Ca2+ from the sarcoplasmic reticulum, suggesting that other regulatory processes are needed to control Ca2+-induced Ca2+ release.

  10. Effects of carbon monoxide on isolated heart muscle cells. Research report, March 1989-February 1992

    SciTech Connect

    Wittenberg, B.A.; Wittenberg, J.B.

    1993-01-01

    By sequestering intracellular myoglobin of cardiac muscle cells in the nonfunctioning carboxymyoglobin form, carbon monoxide blocks myoglobin-facilitated diffusion of oxygen, as well as myoglobin-mediated oxidative phosphorylation. The authors explored the hypothesis that the carbon monoxide blockade of myoglobin function may be responsible at the cellular level for a component of the cardiotoxicity of carbon monoxide observed during exercise. At physiological oxygen pressures no greater than 5 torr, after sequestration of approximately 50% of the myoglobin, steady-state oxygen uptake decreased significantly less than the respiration of cell groups for which the fraction of carboxymyoglobin was 0% to 40%. When respiration is diminished, the rate of oxidative phosphorylation also decreases. Thus, they concluded that sequestering intracellular myoglobin as carboxymyoglobin significantly decreased the rate of oxidative phosphorylation of isolated cardiac myocytes. They estimate that intracellular myoglobin-dependent oxidative phosphorylation will be inhibited when approximately 20% to 40% of the arterial hemoglobin in the whole animal is carboxyhemoglobin.

  11. Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model

    PubMed Central

    Liu, Xiaojuan; Yan, Daliang; Li, Yangcheng; Sha, Xilin; Wu, Kunpeng; Zhao, Jianhua; Yang, Chen; Zhang, Chao

    2016-01-01

    Background Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation. Methods Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1l) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53. Results Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53. Conclusions Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment.

  12. Erythroblast transformation-specific 2 correlates with vascular smooth muscle cell apoptosis in rat heterotopic heart transplantation model

    PubMed Central

    Liu, Xiaojuan; Yan, Daliang; Li, Yangcheng; Sha, Xilin; Wu, Kunpeng; Zhao, Jianhua; Yang, Chen; Zhang, Chao

    2016-01-01

    Background Cardiac allograft vasculopathy (CAV) decreases the long-term survival of heart transplantation recipients. Vascular smooth muscle cell (VSMC) apoptosis is an important pathological feature of CAV. Erythroblast transformation-specific 2 (Ets-2), as a transcription factor, participates in cell apoptosis and plays an important role in organ transplantation. Methods Hearts from Wistar-Furth (WF:RT1u) rats were heterotopically transplanted into Lewis (Lew:RT1l) rats without immunosuppression. Additional syngeneic heterotopic cardiac transplantations were performed in Lewis rats. HE staining was used to identify CAV. Ets-2 expression was examined by western blot. Ets-2 tissue location was examined by immunohistochemical assay and double immunostaining. Cleaved caspase 3 expression was detected by western blot. Co-localization of Ets-2 and cleaved caspase 3 was detected by double immunostaining. Ets-2, p53, cleaved caspase 3 and Bcl-xl expression in rat VSMC line A7R5 was examined after Ets-2 siRNA transfection. TUNEL assay was applied to detect A7R5 apoptosis with or without ETS-2 siRNA transfection. Immunoprecipitation was performed to explore the interaction between Ets-2 and p53. Results Ets-2 expression decreased in the allograft group but had no obvious change in the isograft group. Meanwhile, the phenomenon of CAV was observed in the allograft group and there is neointima formation in the isograft group which is not obvious compared with allograft group. Additionally, Ets-2 expression was opposite to VSMC apoptosis in the allograft group. In vitro, Ets-2 siRNA transfection in A7R5cells resulted in enhanced cell apoptosis. Finally, Ets-2 interacted with p53. Conclusions Ets-2 might inhibit VSMC apoptosis via p53 pathway. The results further elucidate the molecular mechanism of VSMC apoptosis after heart transplantation during CAV and provide theoretical basis for seeking new specific drug targets for CAV prevention and treatment. PMID:27621856

  13. Skeletal Muscle Abnormalities in Heart Failure.

    PubMed

    Kinugawa, Shintaro; Takada, Shingo; Matsushima, Shouji; Okita, Koichi; Tsutsui, Hiroyuki

    2015-01-01

    Exercise capacity is lowered in patients with heart failure, which limits their daily activities and also reduces their quality of life. Furthermore, lowered exercise capacity has been well demonstrated to be closely related to the severity and prognosis of heart failure. Skeletal muscle abnormalities including abnormal energy metabolism, transition of myofibers from type I to type II, mitochondrial dysfunction, reduction in muscular strength, and muscle atrophy have been shown to play a central role in lowered exercise capacity. The skeletal muscle abnormalities can be classified into the following main types: 1) low endurance due to mitochondrial dysfunction; and 2) low muscle mass and muscle strength due to imbalance of protein synthesis and degradation. The molecular mechanisms of these skeletal muscle abnormalities have been studied mainly using animal models. The current review including our recent study will focus upon the skeletal muscle abnormalities in heart failure. PMID:26346520

  14. Clonal analysis reveals a common origin between nonsomite-derived neck muscles and heart myocardium.

    PubMed

    Lescroart, Fabienne; Hamou, Wissam; Francou, Alexandre; Théveniau-Ruissy, Magali; Kelly, Robert G; Buckingham, Margaret

    2015-02-01

    Neck muscles constitute a transition zone between somite-derived skeletal muscles of the trunk and limbs, and muscles of the head, which derive from cranial mesoderm. The trapezius and sternocleidomastoid neck muscles are formed from progenitor cells that have expressed markers of cranial pharyngeal mesoderm, whereas other muscles in the neck arise from Pax3-expressing cells in the somites. Mef2c-AHF-Cre genetic tracing experiments and Tbx1 mutant analysis show that nonsomitic neck muscles share a gene regulatory network with cardiac progenitor cells in pharyngeal mesoderm of the second heart field (SHF) and branchial arch-derived head muscles. Retrospective clonal analysis shows that this group of neck muscles includes laryngeal muscles and a component of the splenius muscle, of mixed somitic and nonsomitic origin. We demonstrate that the trapezius muscle group is clonally related to myocardium at the venous pole of the heart, which derives from the posterior SHF. The left clonal sublineage includes myocardium of the pulmonary trunk at the arterial pole of the heart. Although muscles derived from the first and second branchial arches also share a clonal relationship with different SHF-derived parts of the heart, neck muscles are clonally distinct from these muscles and define a third clonal population of common skeletal and cardiac muscle progenitor cells within cardiopharyngeal mesoderm. By linking neck muscle and heart development, our findings highlight the importance of cardiopharyngeal mesoderm in the evolution of the vertebrate heart and neck and in the pathophysiology of human congenital disease.

  15. Clonal analysis reveals a common origin between nonsomite-derived neck muscles and heart myocardium.

    PubMed

    Lescroart, Fabienne; Hamou, Wissam; Francou, Alexandre; Théveniau-Ruissy, Magali; Kelly, Robert G; Buckingham, Margaret

    2015-02-01

    Neck muscles constitute a transition zone between somite-derived skeletal muscles of the trunk and limbs, and muscles of the head, which derive from cranial mesoderm. The trapezius and sternocleidomastoid neck muscles are formed from progenitor cells that have expressed markers of cranial pharyngeal mesoderm, whereas other muscles in the neck arise from Pax3-expressing cells in the somites. Mef2c-AHF-Cre genetic tracing experiments and Tbx1 mutant analysis show that nonsomitic neck muscles share a gene regulatory network with cardiac progenitor cells in pharyngeal mesoderm of the second heart field (SHF) and branchial arch-derived head muscles. Retrospective clonal analysis shows that this group of neck muscles includes laryngeal muscles and a component of the splenius muscle, of mixed somitic and nonsomitic origin. We demonstrate that the trapezius muscle group is clonally related to myocardium at the venous pole of the heart, which derives from the posterior SHF. The left clonal sublineage includes myocardium of the pulmonary trunk at the arterial pole of the heart. Although muscles derived from the first and second branchial arches also share a clonal relationship with different SHF-derived parts of the heart, neck muscles are clonally distinct from these muscles and define a third clonal population of common skeletal and cardiac muscle progenitor cells within cardiopharyngeal mesoderm. By linking neck muscle and heart development, our findings highlight the importance of cardiopharyngeal mesoderm in the evolution of the vertebrate heart and neck and in the pathophysiology of human congenital disease. PMID:25605943

  16. Calcium homeostasis of isolated heart muscle cells exposed to pulsed high-frequency electromagnetic fields

    SciTech Connect

    Wolke, S.; Gollnick, F.; Meyer, R.; Neibig, U.; Elsner, R.

    1996-05-01

    The intracellular calcium concentration ([Ca{sup 2+}]{sub i}) of isolated ventricular cardiac myocytes of the guinea pig was measured during the application of pulsed high-frequency electromagnetic fields. The high-frequency fields were applied in a transverse electromagnetic cell designed to allow microscopic observation of the myocytes during the presence of the high-frequency fields. The [Ca{sup 2+}]{sub i} was measured as fura-2 fluorescence by means of digital image analysis. Both the carrier frequency and the square-wave pulse-modulation pattern were varied during the experiments (carrier frequencies: 900, 1,300, and 1,800 MHz pulse modulated at 217 Hz with 14% duty cycle; pulsation pattern at 900 MHz; continuous wave, 16 Hz,and 50 Hz modulation with 50% duty cycle and 30 kHz modulation with 80% duty cycle). The mean specific absorption rate (SAR) values in the solution were within one order of magnitude of 1 mW/kg. They varied depending on the applied carrier frequency and pulse pattern. The experiments were designed in three phases: 500 s of sham exposure, followed by 500 s of field exposure, then chemical stimulation without field. The chemical stimulation (K{sup +}-depolarization) indicated the viability of the cells. The K{sup +} depolarization yielded a significant increase in [Ca{sup 2+}]{sub i}. Significant differences between sham exposure and high-frequency field exposure were not found except when a very small but statistically significant difference was detected in the case of 900 MHz/50 Hz. However, this small difference was not regarded as a relevant effect of the exposure.

  17. Subminiature transducers for measuring forces and deformation of heart muscle

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Osher, J. V.; Lewis, G. W.; Silver, R. H.; Duran, E. N.

    1975-01-01

    Two subminiature transducers, one measuring muscle forces and one measuring muscle displacement, can be inserted into heart muscle without interfering with it. Probe, approximately 1 mm (0.04 in), causes no damage to heart muscle. Probe can be rotated to different positions to measure muscle forces from various directions.

  18. Bioengineering Heart Muscle: A Paradigm for Regenerative Medicine

    PubMed Central

    Lui, Kathy O.; Tandon, Nina

    2012-01-01

    The idea of extending the lifetime of our organs is as old as humankind, fueled by major advances in organ transplantation, novel drugs, and medical devices. However, true regeneration of human tissue has becoming increasingly plausible only in recent years. The human heart has always been a focus of such efforts, given its notorious inability to repair itself following injury or disease. We discuss here the emerging bioengineering approaches to regeneration of heart muscle as a paradigm for regenerative medicine. Our focus is on biologically inspired strategies for heart regeneration, knowledge gained thus far about how to make a “perfect” heart graft, and the challenges that remain to be addressed for tissue-engineered heart regeneration to become a clinical reality. We emphasize the need for interdisciplinary research and training, as recent progress in the field is largely being made at the interfaces between cardiology, stem cell science, and bioengineering. PMID:21568715

  19. Micromachined muscle cell analysis chip

    NASA Astrophysics Data System (ADS)

    Wang, Weijie; Li, Paul C. H.; Parameswaran, M.

    2000-10-01

    We report the fabrication of a microfluidic biochip integrated with an acoustic wave sensor that can be used to characterize the contraction of single cardiac (heart) muscle cells. The work will lead to rapid analysis of single muscle cells in response to various drugs by determining changes in mass and viscoelastic properties during cell contraction and relaxation. The microfabricated device is a combination of a top cover plate which is a glass substrate containing etched channels and a bottom plate which is an AT-cut quartz crystal with excitation electrodes. The glass plate is micromachined with a network of channels and chambers, which is intended for delivery of fluids, selection and retention of single muscle cells. The bottom plate (quartz crystal) comprises all the patterned electrodes for acoustic wave launching and detection. The quartz plate is operated in the thickness-shear acoustic wave mode.

  20. SMOOTH MUSCLE STEM CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vascular smooth muscle cells (SMCs) originate from multiple types of progenitor cells. In the embryo, the most well-studied SMC progenitor is the cardiac neural crest stem cell. Smooth muscle differentiation in the neural crest lineage is controlled by a combination of cell intrinsic factors, includ...

  1. [Heart tissue from embryonic stem cells].

    PubMed

    Zimmermann, W-H

    2008-09-01

    Embryonic stem cells can give rise to all somatic cells, making them an attractive cell source for tissue engineering applications. The propensity of cells to form tissue-like structures in a culture dish has been well documented. We and others made use of this intrinsic property to generate bioartificial heart muscle. First proof-of-concept studies involved immature heart cells mainly from fetal chicken, neonatal rats and mice. They eventually provided evidence that force-generating heart muscle can be engineered in vitro. Recently, the focus shifted to the application of stem cells to eventually enable the generation of human heart muscle and reach following long-term goals: (1) development of a simplified in vitro model of heart muscle development; (2) generation of a human test-bed for drug screening and development; (3) allocation of surrogate heart tissue to myocardial repair applications. This overview will provide the background for cell-based myocardial repair, introduce the main myocardial tissue engineering concepts, discuss the use of embryonic and non-embryonic stem cells, and lays out the potential direct and indirect therapeutic use of human tissue engineered myocardium.

  2. Evaluation of iron-chelating agents in cultured heart muscle cells. Identification of a potential drug for chelation therapy.

    PubMed

    Sciortino, C V; Byers, B R; Cox, P

    1980-12-01

    Primary cultures of neonatal rat cardiac muscle cells incorporated radioiron from both [55Fe]transferrin and 59FeCl3 (added simultaneously). To evaluate the effect of iron chelators on such uptake, deferri chelators were added 6 hr after addition of the radioiron sources. The microbial chelator agrobactin was significantly more effective than the drug defoxamine in reduction of 55Fe uptake from [55Fe]transferrin; both chelators halted 59Fe3+ uptake. Agrobactin may have potential in chelation therpay for iron-overload disease. Certain other microbial chelators lowered radioiron uptake from either [55Fe]transferrin of 59FeCl3. These chelators should be useful inhibitors for studies of animal cell iron uptake and intracellular iron flow.

  3. A kinetic study of the oxidation by molecular oxygen of the cytochrome chain of intact yeast cells, Acetobacter suboxydans cells, and of particulate suspensions of heart muscle.

    PubMed

    Ludwig, G D; Kuby, S A; Edelman, G M; Chance, B

    1983-01-01

    The pre-steady state kinetics of the cytochrome c oxidase reaction with oxygen were studied by a variation in the reaction time between approximately 6 and 25 ms at oxygen concentrations less than 6 mumol/l. For baker's yeast, a pseudo-first-order velocity constant of approximately 150 s-1 at 1.3 mumol/l O2 was obtained corresponding to a second-order reaction between O2 and a3 at a forward velocity constant (k+1) of approximately 3 X 10(7) liter equiv.-1s-1. Thus, the membrane-bound oxidase in the intact cell exhibits one of the most rapid enzyme-substrate reactions to be reported. The value is identical with that of Greenwood and Gibson on an isolated, solubilized cytochrome c oxidase. Similar values of k+1 are calculated from the turnover numbers [k+2 (a+2)] divided by the Km values (formula; see text) measured for these yeast preparations, which points to an almost negligible reverse reaction (k-1) compared to k+2(a+2). Similar calculations for the membrane-bound cytochrome c oxidase of heart muscle give a value of k+1 approximately equal to 10(7) liter equiv.-1s-1. The concordance of the different values of k+1 supports the view that the yeast cell wall does not impart a significant diffusion barrier to the transport of molecular oxygen. In contrast, Acetobacter suboxydans exhibits a much larger value for Km, and has a terminal oxidase of different kinetic parameters.

  4. Spirals in the Heart Muscle- From Ventricular Tachycardia to Fibrillation

    NASA Astrophysics Data System (ADS)

    Karma, Alain

    1997-03-01

    Ventricular fibrillation (VF) is an often fatal cardiac arrhythmia. It is associated with the sudden onset of a spatiotemporally disorganised electrical wave activity that destroys the main pumping function of the ventricular muscle. In a healthy heart, VF is preceded by a brief period of ventricular tachycardia (VT), a rapid contraction of the heart muscle which decays into VF in a few seconds. Over the last few years, experiments and theoretical models have converged on the idea that the propagation of a single spiral wave of electrical activity (analogous to spirals found in other excitable media such as the Belousov-Zhabotinsky reaction) is responsible for VT, and that several spirals moving across the heart surface are responsible for VF. Yet, there is still no clear picture of how VT degenerates into VF after being initiated by a premature stimulus. Results of numerical simulations of wave propagation in two and three-dimensional cardiac tissue that identify two important factors in the transition from VT to VF will be presented. The first is the action potential restitution property of cardiac cells that leads to spiral wave instabilities. The second is the twist of the fiber axis that leads to the breakup of scroll wave filaments (i.e. the three-dimensional analog of spiral waves) above a critical muscle thickness.

  5. Manganese depresses rat heart muscle respiration.

    PubMed

    Miller, Kevin B; Caton, Joel S; Finley, John W

    2006-01-01

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and substitute for Mg during the condition of Mg-deficiency. The objective of the current study was to determine whether high Mn alters heart muscle respiration and Mg-enzyme activity as well as whole body Mn retention under marginal Mg. An additional objective was to determine whether high Mn results in increased oxidative stress. In experiment 1: forty-eight rats were fed a 2 x 3 factorial arrangement of Mn (10, 100, or 1000 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 250 mg/kg) and Mg (200 or 500 mg/kg). In experiment 3: thirty-two rats were fed one of four diets in a 2 x 2 factorial arrangement of Mn (10 or 650 mg/kg) and Mg (200 or 500 mg/kg). In experiment 2, high Mn and marginal Mg reduced (P<0.05) oxygen consumption of left ventricle muscle. Marginal Mg, but not Mn, reduced (P<0.05) activity of sarcoplasmic reticulum calcium-ATPase enzyme. Dietary Mg had no affect on (54)Mn kinetics, but high dietary Mn decreased (P<0.01) absorption, retention, and rate of excretion of (54)Mn. Neither cellular stress, measured by Comet assay, nor antioxidant activities were increased by high Mn. A strong interaction (P<0.001) between increasing Mn and adequate Mg on hematology was observed. These results confirm previous research in swine that high Mn alters myocardial integrity as well as function, but not as a result of altered calcium transport or oxidative stress.

  6. Enzyme activities and adenine nucleotide content in aorta, heart muscle and skeletal muscle from uraemic rats.

    PubMed Central

    Krog, M.; Ejerblad, S.; Agren, A.

    1986-01-01

    A prominent feature of arterial and myocardial lesions in uraemia is necrosis of the smooth muscle cells. In this study the possibility of detecting metabolic disturbances before necroses appear was investigated. The investigation was made on rats with moderate uraemia (mean serum creatinine 165 mumol/l) of 12 weeks duration. Enzyme activities and concentrations of adenine nucleotides were measured in aorta, heart and skeletal muscles. Histological examination disclosed no changes in these organs. Hexokinase, an important glycolytic enzyme, showed decreased activity in the skeletal muscle and aorta, whereas the hexosemonophosphate shunt enzyme glucose-6-phosphate dehydrogenase remained unchanged. The aspartate aminotransferase was increased in the skeletal muscle. Fat metabolism was not disturbed as reflected by unchanged activity of hydroxyacyl-CoA-dehydrogenase. Adenylatekinase which is important for the energy supply showed markedly increased activities in all tissues examined from the uraemic rats. Decreased ATP levels were found in the heart muscle and the aorta of the uraemic animals, whereas the total pool of adenosine phosphates remained unchanged in all tissues. The animal model described offers a useful means of detecting early changes in uraemia and should be useful for studying the effects of different treatments of uraemic complications. PMID:3718844

  7. Skeletal muscle satellite cells

    NASA Technical Reports Server (NTRS)

    Schultz, E.; McCormick, K. M.

    1994-01-01

    Evidence now suggests that satellite cells constitute a class of myogenic cells that differ distinctly from other embryonic myoblasts. Satellite cells arise from somites and first appear as a distinct myoblast type well before birth. Satellite cells from different muscles cannot be functionally distinguished from one another and are able to provide nuclei to all fibers without regard to phenotype. Thus, it is difficult to ascribe any significant function to establishing or stabilizing fiber type, even during regeneration. Within a muscle, satellite cells exhibit marked heterogeneity with respect to their proliferative behavior. The satellite cell population on a fiber can be partitioned into those that function as stem cells and those which are readily available for fusion. Recent studies have shown that the cells are not simply spindle shaped, but are very diverse in their morphology and have multiple branches emanating from the poles of the cells. This finding is consistent with other studies indicating that the cells have the capacity for extensive migration within, and perhaps between, muscles. Complexity of cell shape usually reflects increased cytoplasmic volume and organelles including a well developed Golgi, and is usually associated with growing postnatal muscle or muscles undergoing some form of induced adaptive change or repair. The appearance of activated satellite cells suggests some function of the cells in the adaptive process through elaboration and secretion of a product. Significant advances have been made in determining the potential secretion products that satellite cells make. The manner in which satellite cell proliferative and fusion behavior is controlled has also been studied. There seems to be little doubt that cellcell coupling is not how satellite cells and myofibers communicate. Rather satellite cell regulation is through a number of potential growth factors that arise from a number of sources. Critical to the understanding of this form

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

    PubMed Central

    Randolph, Matthew E.; Pavlath, Grace K.

    2015-01-01

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

  9. Studies on proteolytic activities in heart muscle of diabetic rats.

    PubMed

    Dahlmann, B; Metzinger, H; Reinauer, H

    1982-06-01

    Induction of diabetes mellitus in rats following injection of streptozotocin caused reduction in rate of gain of heart weight, of protein and of DNA content in the first two weeks. During the same time interval the overall activity of acid proteinases (cathepsin D), of alkaline proteinases and of proteinase inhibitors was measured in heart muscle homogenates. No statistically significant differences were detected compared with the proteinase activities in control rats. In contrast, total aminopeptidase activity in diabetic hearts was consistently lower than in control hearts. Earlier studies on rat skeletal muscles have shown that induction of diabetes mellitus is followed by a substantial increase of alkaline proteinase as well as aminopeptidase activities. These findings are contrasted by present data obtained with heart muscle of diabetic rats, suggesting that this tissue responds differently to insulin deficiency.

  10. Programming and reprogramming a human heart cell.

    PubMed

    Sahara, Makoto; Santoro, Federica; Chien, Kenneth R

    2015-03-12

    The latest discoveries and advanced knowledge in the fields of stem cell biology and developmental cardiology hold great promise for cardiac regenerative medicine, enabling researchers to design novel therapeutic tools and approaches to regenerate cardiac muscle for diseased hearts. However, progress in this arena has been hampered by a lack of reproducible and convincing evidence, which at best has yielded modest outcomes and is still far from clinical practice. To address current controversies and move cardiac regenerative therapeutics forward, it is crucial to gain a deeper understanding of the key cellular and molecular programs involved in human cardiogenesis and cardiac regeneration. In this review, we consider the fundamental principles that govern the "programming" and "reprogramming" of a human heart cell and discuss updated therapeutic strategies to regenerate a damaged heart.

  11. Manganese depresses rat heart muscle respiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has previously been reported that moderately high dietary manganese (Mn) in combination with marginal magnesium (Mg) resulted in ultrastructural damage to heart mitochondria. Manganese may replace Mg in biological functions, including the role of enzyme cofactor. Manganese may accumulate and subs...

  12. Dietary Nitrate and Skeletal Muscle Contractile Function in Heart Failure.

    PubMed

    Coggan, Andrew R; Peterson, Linda R

    2016-08-01

    Heart failure (HF) patients suffer from exercise intolerance that diminishes their ability to perform normal activities of daily living and hence compromises their quality of life. This is due largely to detrimental changes in skeletal muscle mass, structure, metabolism, and function. This includes an impairment of muscle contractile performance, i.e., a decline in the maximal force, speed, and power of muscle shortening. Although numerous mechanisms underlie this reduction in contractility, one contributing factor may be a decrease in nitric oxide (NO) bioavailability. Consistent with this, recent data demonstrate that acute ingestion of NO3 (-)-rich beetroot juice, a source of NO via the NO synthase-independent enterosalivary pathway, markedly increases maximal muscle speed and power in HF patients. This review discusses the role of muscle contractile dysfunction in the exercise intolerance characteristic of HF, and the evidence that dietary NO3 (-) supplementation may represent a novel and simple therapy for this currently underappreciated problem. PMID:27271563

  13. Isolation, culture, and transplantation of muscle satellite cells.

    PubMed

    Motohashi, Norio; Asakura, Yoko; Asakura, Atsushi

    2014-01-01

    Muscle satellite cells are a stem cell population required for postnatal skeletal muscle development and regeneration, accounting for 2-5% of sublaminal nuclei in muscle fibers. In adult muscle, satellite cells are normally mitotically quiescent. Following injury, however, satellite cells initiate cellular proliferation to produce myoblasts, their progenies, to mediate the regeneration of muscle. Transplantation of satellite cell-derived myoblasts has been widely studied as a possible therapy for several regenerative diseases including muscular dystrophy, heart failure, and urological dysfunction. Myoblast transplantation into dystrophic skeletal muscle, infarcted heart, and dysfunctioning urinary ducts has shown that engrafted myoblasts can differentiate into muscle fibers in the host tissues and display partial functional improvement in these diseases. Therefore, the development of efficient purification methods of quiescent satellite cells from skeletal muscle, as well as the establishment of satellite cell-derived myoblast cultures and transplantation methods for myoblasts, are essential for understanding the molecular mechanisms behind satellite cell self-renewal, activation, and differentiation. Additionally, the development of cell-based therapies for muscular dystrophy and other regenerative diseases are also dependent upon these factors. However, current prospective purification methods of quiescent satellite cells require the use of expensive fluorescence-activated cell sorting (FACS) machines. Here, we present a new method for the rapid, economical, and reliable purification of quiescent satellite cells from adult mouse skeletal muscle by enzymatic dissociation followed by magnetic-activated cell sorting (MACS). Following isolation of pure quiescent satellite cells, these cells can be cultured to obtain large numbers of myoblasts after several passages. These freshly isolated quiescent satellite cells or ex vivo expanded myoblasts can be transplanted

  14. Heart-on-a-chip based on stem cell biology.

    PubMed

    Jastrzebska, Elzbieta; Tomecka, Ewelina; Jesion, Iwona

    2016-01-15

    Heart diseases are one of the main causes of death around the world. The great challenge for scientists is to develop new therapeutic methods for these types of ailments. Stem cells (SCs) therapy could be one of a promising technique used for renewal of cardiac cells and treatment of heart diseases. Conventional in vitro techniques utilized for investigation of heart regeneration do not mimic natural cardiac physiology. Lab-on-a-chip systems may be the solution which could allow the creation of a heart muscle model, enabling the growth of cardiac cells in conditions similar to in vivo conditions. Microsystems can be also used for differentiation of stem cells into heart cells, successfully. It will help better understand of proliferation and regeneration ability of these cells. In this review, we present Heart-on-a-chip systems based on cardiac cell culture and stem cell biology. This review begins with the description of the physiological environment and the functions of the heart. Next, we shortly described conventional techniques of stem cells differentiation into the cardiac cells. This review is mostly focused on describing Lab-on-a-chip systems for cardiac tissue engineering. Therefore, in the next part of this article, the microsystems for both cardiac cell culture and SCs differentiation into cardiac cells are described. The section about SCs differentiation into the heart cells is divided in sections describing biochemical, physical and mechanical stimulations. Finally, we outline present challenges and future research concerning Heart-on-a-chip based on stem cell biology.

  15. Cardiac autoimmunity in HIV related heart muscle disease

    PubMed Central

    Currie, P; Goldman, J; Caforio, A; Jacob, A; Baig, M; Brettle, R; Haven, A; Boon, N; McKenna, W

    1998-01-01

    Objective—To assess the frequency of circulating cardiac specific autoantibodies in HIV positive patients with and without echocardiographic evidence of left ventricular dysfunction.
Subjects—74 HIV positive patients including 28 with echocardiographic evidence of heart muscle disease, 52 HIV negative people at low risk of HIV infection, and 14 HIV negative drug users who had all undergone non-invasive cardiac assessment were studied along with a group of 200 healthy blood donors.
Results—Cardiac autoantibodies detected by indirect immunofluorescence (serum dilution 1/10) were more common in the HIV positive patients (15%), particularly the HIV heart muscle disease group (21%), than in HIV negative controls (3.5%) (both p < 0.001). By ELISA (dilution 1/320), abnormal anti-α myosin autoantibody concentrations were found more often in HIV patients with heart muscle disease (43%) than in HIV positive patients with normal hearts (19%) or in HIV negative controls (3%) (p < 0.05 and p < 0.001, respectively). Anti-α myosin autoantibody concentrations were greater in HIV positive patients than in HIV negative controls, regardless of cardiac status ((mean SD) 0.253 (0.155) v 0.170 (0.076); p = 0.003). In particular the mean antibody concentration was higher in the HIV heart muscle disease patients (0.291 (0.160) v 0.170 (0.076); p = 0.001) than in HIV negative controls. On follow up, six subjects with normal echocardiograms but raised autoantibody concentrations had died after a median of 298 days, three with left ventricular abnormalities at necropsy. This compared with a median survival of 536 days for 21 HIV positive patients with normal cardiological and immunological results.
Conclusions—There is an increased frequency of circulating cardiac specific autoantibodies in HIV positive individuals, particularly those with heart muscle disease. The data support a role for cardiac autoimmunity in the pathogenesis of HIV related heart

  16. Dissemination of Walker 256 carcinoma cells to rat skeletal muscle

    SciTech Connect

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

    1986-03-05

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

  17. Respiratory muscle function and exercise intolerance in heart failure.

    PubMed

    Ribeiro, Jorge P; Chiappa, Gaspar R; Neder, J Alberto; Frankenstein, Lutz

    2009-06-01

    Inspiratory muscle weakness (IMW) is prevalent in patients with chronic heart failure (CHF) caused by left ventricular systolic dysfunction, which contributes to reduced exercise capacity and the presence of dyspnea during daily activities. Inspiratory muscle strength (estimated by maximal inspiratory pressure) has independent prognostic value in CHF. Overall, the results of trials with inspiratory muscle training (IMT) indicate that this intervention improves exercise capacity and quality of life, particularly in patients with CHF and IMW. Some benefit from IMT may be accounted for by the attenuation of the inspiratory muscle metaboreflex. Moreover, IMT results in improved cardiovascular responses to exercise and to those obtained with standard aerobic training. These findings suggest that routine screening for IMW is advisable in patients with CHF, and specific IMT and/or aerobic training are of practical value in the management of these patients. PMID:19486593

  18. Respiratory muscle function and exercise intolerance in heart failure.

    PubMed

    Ribeiro, Jorge P; Chiappa, Gaspar R; Neder, J Alberto; Frankenstein, Lutz

    2009-06-01

    Inspiratory muscle weakness (IMW) is prevalent in patients with chronic heart failure (CHF) caused by left ventricular systolic dysfunction, which contributes to reduced exercise capacity and the presence of dyspnea during daily activities. Inspiratory muscle strength (estimated by maximal inspiratory pressure) has independent prognostic value in CHF. Overall, the results of trials with inspiratory muscle training (IMT) indicate that this intervention improves exercise capacity and quality of life, particularly in patients with CHF and IMW. Some benefit from IMT may be accounted for by the attenuation of the inspiratory muscle metaboreflex. Moreover, IMT results in improved cardiovascular responses to exercise and to those obtained with standard aerobic training. These findings suggest that routine screening for IMW is advisable in patients with CHF, and specific IMT and/or aerobic training are of practical value in the management of these patients.

  19. Muscle size explains low passive skeletal muscle force in heart failure patients

    PubMed Central

    Maiorana, Andrew J.; Naylor, Louise H.; Dembo, Lawrence G.; Lloyd, David G.; Green, Daniel J.; Rubenson, Jonas

    2016-01-01

    Background Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL), both in CHF patients and age- and physical activity-matched control participants. Methods Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging) with a musculoskeletal model. Results We found reduced passive SOL forces (∼30%) (at the same relative levels of muscle stretch) in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized) and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. Discussion These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening. PMID:27672504

  20. Muscle size explains low passive skeletal muscle force in heart failure patients

    PubMed Central

    Maiorana, Andrew J.; Naylor, Louise H.; Dembo, Lawrence G.; Lloyd, David G.; Green, Daniel J.; Rubenson, Jonas

    2016-01-01

    Background Alterations in skeletal muscle function and architecture have been linked to the compromised exercise capacity characterizing chronic heart failure (CHF). However, how passive skeletal muscle force is affected in CHF is not clear. Understanding passive force characteristics in CHF can help further elucidate the extent to which altered contractile properties and/or architecture might affect muscle and locomotor function. Therefore, the aim of this study was to investigate passive force in a single muscle for which non-invasive measures of muscle size and estimates of fiber force are possible, the soleus (SOL), both in CHF patients and age- and physical activity-matched control participants. Methods Passive SOL muscle force and size were obtained by means of a novel approach combining experimental data (dynamometry, electromyography, ultrasound imaging) with a musculoskeletal model. Results We found reduced passive SOL forces (∼30%) (at the same relative levels of muscle stretch) in CHF vs. healthy individuals. This difference was eliminated when force was normalized by physiological cross sectional area, indicating that reduced force output may be most strongly associated with muscle size. Nevertheless, passive force was significantly higher in CHF at a given absolute muscle length (non length-normalized) and likely explained by the shorter muscle slack lengths and optimal muscle lengths measured in CHF compared to the control participants. This later factor may lead to altered performance of the SOL in functional tasks such gait. Discussion These findings suggest introducing exercise rehabilitation targeting muscle hypertrophy and, specifically for the calf muscles, exercise that promotes muscle lengthening.

  1. Nemaline rod and degeneration of Z band of muscle cell in weightlessness at spaceflight

    NASA Astrophysics Data System (ADS)

    Imuta, Miharu; Higuchi, Itsuro

    1999-06-01

    There are some studies demonstrating the skeletal muscle degeneration associated with the degeneration of Z band and appearance of nemaline rods in experimental animals of the simulation model for spaceflight but not in human heart tissues. In the present study, therefore, we investigated the pathological changes or degeneration in left auricular heart muscles obtained during operations of mitral valves replacement using both electron and light microscopies. The degeneration of Z band even in the myofibrils of comparatively little damaged cell was found. Furthermore, nemaline rods were detected in most of the heart muscle cells. These results suggest that the existence of nemaline rods is involved in the cell injury in the heart muscle of patients with heart disease without nemaline myopathy. Further study is necessary to know whether the similar pathological findings are observed not only in the skeletal muscle but also in the cardiac muscle in experimental animals of the simulation model for spaceflight or in a prolonged spaceflight.

  2. Cyclooxygenase products sensitize muscle mechanoreceptors in humans with heart failure.

    PubMed

    Middlekauff, Holly R; Chiu, Josephine; Hamilton, Michele A; Fonarow, Gregg C; Maclellan, W Robb; Hage, Antoine; Moriguchi, Jaime; Patel, Jignesh

    2008-04-01

    Prior work in animals and humans suggests that muscle mechanoreceptor control of sympathetic activation [muscle sympathetic nerve activity (MSNA)] during exercise in heart failure (HF) patients is heightened compared with that of healthy humans and that muscle mechanoreceptors are sensitized by metabolic by-products. We sought to determine whether cyclooxygenase products and/or endogenous adenosine, two metabolites of ischemic exercise, sensitize muscle mechanoreceptors during rhythmic handgrip (RHG) exercise in HF patients. Indomethacin, which inhibits the production of prostaglandins, and saline control were infused in 12 HF patients. In a different protocol, aminophylline, which inhibits adenosine receptors, and saline control were infused in 12 different HF patients. MSNA was recorded (microneurography). During exercise following saline, MSNA increased in the first minute of exercise, consistent with baseline heightened mechanoreceptor sensitivity. MSNA continued to increase during 3 min of RHG, indicative that muscle mechanoreceptors are sensitized by ischemia metabolites. Indomethacin, but not aminophylline, markedly attenuated the increase in MSNA during the entire 3 min of low-level rhythmic exercise, consistent with the sensitization of muscle mechanoreceptors by cyclooxygenase products. Interestingly, even the early increase in MSNA was abolished by indomethacin infusion, indicative of the very early generation of cyclooxygenase products after the onset of exercise in HF patients. In conclusion, muscle mechanoreceptors mediate the increase in MSNA during low-level RHG exercise in HF. Cyclooxygenase products, but not endogenous adenosine, play a central role in muscle mechanoreceptor sensitization. Finally, muscle mechanoreceptors in patients with HF have heightened basal sensitivity to mechanical stimuli, which also appears to be mediated by the early generation of cyclooxygenase products, resulting in exaggerated early increases in MSNA.

  3. Mechanical stimulation in the engineering of heart muscle.

    PubMed

    Liaw, Norman Yu; Zimmermann, Wolfram-Hubertus

    2016-01-15

    Recreating the beating heart in the laboratory continues to be a formidable bioengineering challenge. The fundamental feature of the heart is its pumping action, requiring considerable mechanical forces to compress a blood filled chamber with a defined in- and outlet. Ventricular output crucially depends on venous loading of the ventricles (preload) and on the force generated by the preloaded ventricles to overcome arterial blood pressure (afterload). The rate of contraction is controlled by the spontaneously active sinus node and transmission of its electrical impulses into the ventricles. The underlying principles for these physiological processes are described by the Frank-Starling mechanism and Bowditch phenomenon. It is essential to consider these principles in the design and evaluation of tissue engineered myocardium. This review focuses on current strategies to evoke mechanical loading in hydrogel-based heart muscle engineering.

  4. Soleus Muscle as a Surrogate for Health Status in Human Heart Failure.

    PubMed

    Green, Daniel J; Panizzolo, Fausto A; Lloyd, David G; Rubenson, Jonas; Maiorana, Andrew J

    2016-01-01

    We propose the hypothesis that soleus muscle function may provide a surrogate measure of functional capacity in patients with heart failure. We summarize literature pertaining to skeletal muscle as a locus of fatigue and present our recent findings, using in vivo imaging in combination with biomechanical experimentation and modeling, to reveal novel structure-function relationships in chronic heart failure skeletal muscle and gait.

  5. Effects of cadmium on contractility and calcium concentration in isolated heart muscle

    SciTech Connect

    Pilati, C.F.; Ewing, K.L.; Paradise, N.F.

    1982-04-01

    The isometrically arranged kitten heart papillary muscle was used to study the depressant actions of cadmium ion (Cd/sup 2 +/) on heart muscle function. Although the Cd/sup 2 +/- induced decreases in papillary muscle tension development were dose dependent, peak tension was restored to pretreatment control only after the termination of 1 ..mu..M, but not 10 or 100 ..mu..M Cd/sup 2 +/ exposure. The Schild plot suggested that Cd/sup 2 +/ and Ca/sup 2 +/ are competitive antagonists but two additional observations indicated that noncompetitive mechanisms are also involved: (a) the contour of the tension twitch from the Cd/sup 2 +/ -depressed muscle could not be restored to pre-cadmium control by increasing extracellular Ca/sup 2 +/ concentration, and (b) the contraction pattern after a reduction in external Ca/sup 2 +/ concentration from 2.0 to 0.5 mM differed from that after exposure to 25 ..mu..M Cd/sup 2 +/, even though both treatments depressed peak tension development by 80%. When the coronary-perfused rabbit heart was employed, left ventricular Ca concentration was not affected by perfusion with 100 ..mu..M Cd/sup 2 +/ even though mechanical function was obliterated by this dose. In conclusion the mechanisms of action of Cd/sup 2 +/ are complex and do not appear to involve the displacement of Ca from the cardiac cell.

  6. Kinetics and thermodynamics of lactate dehydrogenases from beef heart, beef muscle, and flounder muscle.

    PubMed

    Borgmann, U; Laidler, K J; Moon, T W

    1975-11-01

    The eight rate constants for a four-step ordered ternary-complex mechanism have been compared for lactate dehydrogenases (EC1.1.1.27) from three sources, beef heart, beef muscle, and flounder muscle. The rate constants were determined at temperatures ranging from 5 degrees C to 50 degrees C, and the corresponding activation parameters deltaG not equal to, deltaH not equal to, and deltaS not equal to were calculated. Significant differences are noted for the values for the three types of enzyme. The relative heights of the activation barriers are much the same in all three cases, differences in kinetic behavior resulting mainly from differences in the stable binary and ternary enzyme-substrate complexes. These complexes are, in general, at lower free-energy and enthalpy levels of the beef-heart and beef-muscle enzymes than for the flounder-muscle enzyme. A high degree of compensation is found between the enthalpies and entropies of activation, resulting in relatively small differences between the free energies (and rates) for homologous steps with different enzymes. Analysis of the results, on the assumption that the compensation effect is due to weak-bonding effects, suggests that there are fewer weak bonds in the stable complexes of the muscle enzymes.

  7. Muscle stem cells at a glance

    PubMed Central

    Wang, Yu Xin; Dumont, Nicolas A.; Rudnicki, Michael A.

    2014-01-01

    ABSTRACT Muscle stem cells facilitate the long-term regenerative capacity of skeletal muscle. This self-renewing population of satellite cells has only recently been defined through genetic and transplantation experiments. Although muscle stem cells remain in a dormant quiescent state in uninjured muscle, they are poised to activate and produce committed progeny. Unlike committed myogenic progenitor cells, the self-renewal capacity gives muscle stem cells the ability to engraft as satellite cells and capitulate long-term regeneration. Similar to other adult stem cells, understanding the molecular regulation of muscle stem cells has significant implications towards the development of pharmacological or cell-based therapies for muscle disorders. This Cell Science at a Glance article and accompanying poster will review satellite cell characteristics and therapeutic potential, and provide an overview of the muscle stem cell hallmarks: quiescence, self-renewal and commitment. PMID:25300792

  8. Physiologic force-frequency in engineered heart muscle by electromechanical stimulation

    PubMed Central

    Godier-Furnémont, Amandine F. G.; Tiburcy, Malte; Wagner, Eva; Dewenter, Matthias; Lämmle, Simon; El-Armouche, Ali; Lehnart, Stephan E.; Vunjak-Novakovic, Gordana; Zimmermann, Wolfram-Hubertus

    2016-01-01

    A hallmark of mature mammalian ventricular myocardium is a positive force-frequency relationship (FFR). Despite evidence of organotypic structural and molecular maturation, a positive FFR has not been observed in mammalian tissue engineered heart muscle. We hypothesized that concurrent mechanical and electrical stimulation at frequencies matching physiological heart rate will result in functional maturation. To this end, we investigated the role of such biomimetic mechanical and electrical stimulation in functional maturation in engineered heart muscle (EHM) comprising collagen type I and neonatal rat heart cells. Following tissue consolidation (8 days), EHM were subjected to electrical field stimulation at 0, 2, 4, or 6 Hz for 5 days, while strained on flexible poles to facilitate auxotonic contractions. EHM stimulated at 2 and 4 Hz displayed a similarly enhanced inotropic reserve, but a clearly diverging FFR. The positive FFR in 4 Hz stimulated EHM was associated with reduced calcium sensitivity, frequency-dependent acceleration of relaxation, and enhanced post-rest potentiation. This was paralleled on the cellular level with improved calcium storage and release capacity of the sarcoplasmic reticulum, increased amounts of SERCA2a and RyR2 protein, and enhanced T-tubulation. We demonstrate that electromechanical stimulation at a frequency matching closely the physiological heart rate supports functional maturation in mammalian EHM. The observed positive FFR in EHM has important implications for the applicability of EHM in cardiovascular research and drug testing. PMID:25985155

  9. Alcohol differentially alters extracellular matrix and adhesion molecule expression in skeletal muscle and heart

    PubMed Central

    Steiner, Jennifer L.; Pruznak, Anne M.; Navaratnarajah, Maithili; Lang, Charles H.

    2015-01-01

    Background The production of fibrosis in response to chronic alcohol abuse is well recognized in liver but has not been fully characterized in striated muscle and may contribute to functional impairment. Therefore, the purpose of this study was to use an unbiased discovery-based approach to determine the effect of chronic alcohol consumption on the expression profile of genes important for cell-cell and cell-extracellular matrix (ECM) interactions in both skeletal and cardiac muscle. Methods Adult male rats were pair-fed an alcohol-containing liquid diet or control diet for 24 wks, and skeletal muscle (gastrocnemius) and heart collected in the freely fed state. A pathway-focused gene expression PCR array was performed on these tissues to assess mRNA content for 84 ECM proteins, and selected proteins were confirmed by Western analysis. Results In gastrocnemius, alcohol feeding up-regulated expression of 11 genes and down-regulated expression of 1 gene. Alcohol increased fibrosis as indicated by increased mRNA and/or protein for collagen α1(I), α2(I), α1(III) and α2(IV) as well as hydroxyproline. Alcohol also increased α-smooth muscle actin protein, an index of myofibroblast activation, but no concomitant change in TGF-β was detected. The mRNA and protein content for other ECM components, such as integrin α-5, L-selectin, PECAM, Sparc and Adamts2 was also increased by alcohol. Only laminin α-3 mRNA was decreased in gastrocnemius from alcohol-fed rats, while 66 ECM- or cell adhesion-related mRNAs were unchanged by alcohol. For heart, expression of 16 genes was up-regulated, expression of 3 genes was down-regulated, and 65 mRNAs were unchanged by alcohol; there were no common alcohol-induced gene expression changes between heart and skeletal muscle. Finally, alcohol increased TNFα and IL-12 mRNA in both skeletal and cardiac muscle, but IL-6 mRNA was increased and IL-10 mRNA decreased only in skeletal muscle. Conclusions These data demonstrate a fibrotic

  10. cap alpha. -skeletal and. cap alpha. -cardiac actin genes are coexpressed in adult human skeletal muscle and heart

    SciTech Connect

    Gunning, P.; Ponte, P.; Blau, H.; Kedes, L.

    1983-11-01

    The authors determined the actin isotypes encoded by 30 actin cDNA clones previously isolated from an adult human muscle cDNA library. Using 3' untranslated region probes, derived from ..cap alpha.. skeletal, ..beta..- and ..gamma..-actin cDNAs and from an ..cap alpha..-cardiac actin genomic clone, they showed that 28 of the cDNAs correspond to ..cap alpha..-skeletal actin transcripts. Unexpectedly, however, the remaining two cDNA clones proved to derive from ..cap alpha..-cardiac actin mRNA. Sequence analysis confirmed that the two skeletal muscle ..cap alpha..-cardiac actin cDNAs are derived from transcripts of the cloned ..cap alpha..-cardiac actin gene. Comparison of total actin mRNA levels in adult skeletal muscle and adult heart revealed that the steady-state levels in skeletal muscle are about twofold greater, per microgram of total cellular RNA, than those in heart. Thus, in skeletal muscle and in heart, both of the sarcomeric actin mRNA isotypes are quite abundant transcripts. They conclude that ..cap alpha..-skeletal and ..cap alpha..-cardiac actin genes are coexpressed as an actin pair in human adult striated muscles. Since the smooth-muscle actins (aortic and stomach) and the cytoplasmic actins (..beta.. and ..gamma..) are known to be coexpressed in smooth muscle and nonmuscle cells, respectively, they postulate that coexpression of actin pairs may be a common feature of mammalian actin gene expression in all tissues.

  11. Muscle reflex in heart failure: the role of exercise training

    PubMed Central

    Wang, Han-Jun; Zucker, Irving H.; Wang, Wei

    2012-01-01

    Exercise evokes sympathetic activation and increases blood pressure and heart rate (HR). Two neural mechanisms that cause the exercise-induced increase in sympathetic discharge are central command and the exercise pressor reflex (EPR). The former suggests that a volitional signal emanating from central motor areas leads to increased sympathetic activation during exercise. The latter is a reflex originating in skeletal muscle which contributes significantly to the regulation of the cardiovascular and respiratory systems during exercise. The afferent arm of this reflex is composed of metabolically sensitive (predominantly group IV, C-fibers) and mechanically sensitive (predominately group III, A-delta fibers) afferent fibers. Activation of these receptors and their associated afferent fibers reflexively adjusts sympathetic and parasympathetic nerve activity during exercise. In heart failure, the sympathetic activation during exercise is exaggerated, which potentially increases cardiovascular risk and contributes to exercise intolerance during physical activity in chronic heart failure (CHF) patients. A therapeutic strategy for preventing or slowing the progression of the exaggerated EPR may be of benefit in CHF patients. Long-term exercise training (ExT), as a non-pharmacological treatment for CHF increases exercise capacity, reduces sympatho-excitation and improves cardiovascular function in CHF animals and patients. In this review, we will discuss the effects of ExT and the mechanisms that contribute to the exaggerated EPR in the CHF state. PMID:23060821

  12. Research Sees Potential to Make Bone, Muscle from Human Stem Cells

    MedlinePlus

    ... 159885.html Research Sees Potential to Make Bone, Muscle From Human Stem Cells Could be a major advance for regenerative medicine, ... and chemical signals needed to make bone, heart muscle and 10 other cells types from human stem cells within a matter of days. The researchers ...

  13. Skeletal muscle electrical stimulation improves baroreflex sensitivity and heart rate variability in heart failure rats.

    PubMed

    Lazzarotto Rucatti, Ananda; Jaenisch, Rodrigo Boemo; Rossato, Douglas Dalcin; Bonetto, Jéssica Hellen Poletto; Ferreira, Janaína; Xavier, Leder Leal; Sonza, Anelise; Dal Lago, Pedro

    2015-12-01

    The goal of the current study was to evaluate the effects of electrical stimulation (ES) on the arterial baroreflex sensitivity (BRS) and cardiovascular autonomic control in rats with chronic heart failure (CHF). Male Wistar rats were designated to one of four groups: placebo sham (P-Sham, n=9), ES sham (ES-Sham, n=9), placebo CHF (P-CHF, n=9) or ES CHF (ES-CHF, n=9). The ES was adjusted at a low frequency (30 Hz), duration of 250 μs, with hold and rest time of 8s (4 weeks, 30 min/day, 5 times/week). It was applied on the gastrocnemius muscle with intensity to produce a visible muscle contraction. The rats assigned to the placebo groups performed the same procedures with the equipment turned off. The two-way ANOVA and the post hoc Student-Newman-Keuls tests (P<0.05) were used to data comparison. The BRS was higher in ES-Sham group compared to the P-Sham group and the ES-CHF group compared to the P-CHF group. ES was able to decrease heart rate sympatho-vagal modulation and peripheral sympathetic modulation in ES-CHF compared to P-CHF group. Interestingly, heart rate sympatho-vagal modulation was similar between ES-CHF and P-Sham groups. Thus, ES enhances heart rate parasympathetic modulation on heart failure (ES-CHF) compared to placebo (P-CHF), with consequent decrease of sympatho-vagal balance in the ES-CHF group compared to the P-CHF. The results show that a 4 week ES protocol in CHF rats enhances arterial BRS and cardiovascular autonomic control.

  14. Satellite cells in human skeletal muscle plasticity.

    PubMed

    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.

  15. Cell migration during heart regeneration in zebrafish.

    PubMed

    Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

    2016-07-01

    Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. PMID:27085002

  16. Endothelial cells are progenitors of cardiac pericytes and vascular smooth muscle cells

    PubMed Central

    Chen, Qi; Zhang, Hui; Liu, Yang; Adams, Susanne; Eilken, Hanna; Stehling, Martin; Corada, Monica; Dejana, Elisabetta; Zhou, Bin; Adams, Ralf H.

    2016-01-01

    Mural cells of the vessel wall, namely pericytes and vascular smooth muscle cells, are essential for vascular integrity. The developmental sources of these cells and molecular mechanisms controlling their progenitors in the heart are only partially understood. Here we show that endocardial endothelial cells are progenitors of pericytes and vascular smooth muscle cells in the murine embryonic heart. Endocardial cells undergo endothelial–mesenchymal transition and convert into primitive mesenchymal progenitors expressing the platelet-derived growth factor receptors, PDGFRα and PDGFRβ. These progenitors migrate into the myocardium, differentiate and assemble the wall of coronary vessels, which requires canonical Wnt signalling involving Frizzled4, β-catenin and endothelial cell-derived Wnt ligands. Our findings identify a novel and unexpected population of progenitors for coronary mural cells with potential relevance for heart function and disease conditions. PMID:27516371

  17. Mesp1 Marked Cardiac Progenitor Cells Repair Infarcted Mouse Hearts

    PubMed Central

    Liu, Yu; Chen, Li; Diaz, Andrea Diaz; Benham, Ashley; Xu, Xueping; Wijaya, Cori S.; Fa’ak, Faisal; Luo, Weijia; Soibam, Benjamin; Azares, Alon; Yu, Wei; Lyu, Qiongying; Stewart, M. David; Gunaratne, Preethi; Cooney, Austin; McConnell, Bradley K.; Schwartz, Robert J.

    2016-01-01

    Mesp1 directs multipotential cardiovascular cell fates, even though it’s transiently induced prior to the appearance of the cardiac progenitor program. Tracing Mesp1-expressing cells and their progeny allows isolation and characterization of the earliest cardiovascular progenitor cells. Studying the biology of Mesp1-CPCs in cell culture and ischemic disease models is an important initial step toward using them for heart disease treatment. Because of Mesp1’s transitory nature, Mesp1-CPC lineages were traced by following EYFP expression in murine Mesp1Cre/+; Rosa26EYFP/+ ES cells. We captured EYFP+ cells that strongly expressed cardiac mesoderm markers and cardiac transcription factors, but not pluripotent or nascent mesoderm markers. BMP2/4 treatment led to the expansion of EYFP+ cells, while Wnt3a and Activin were marginally effective. BMP2/4 exposure readily led EYFP+ cells to endothelial and smooth muscle cells, but inhibition of the canonical Wnt signaling was required to enter the cardiomyocyte fate. Injected mouse pre-contractile Mesp1-EYFP+ CPCs improved the survivability of injured mice and restored the functional performance of infarcted hearts for at least 3 months. Mesp1-EYFP+ cells are bona fide CPCs and they integrated well in infarcted hearts and emerged de novo into terminally differentiated cardiac myocytes, smooth muscle and vascular endothelial cells. PMID:27538477

  18. Mesp1 Marked Cardiac Progenitor Cells Repair Infarcted Mouse Hearts.

    PubMed

    Liu, Yu; Chen, Li; Diaz, Andrea Diaz; Benham, Ashley; Xu, Xueping; Wijaya, Cori S; Fa'ak, Faisal; Luo, Weijia; Soibam, Benjamin; Azares, Alon; Yu, Wei; Lyu, Qiongying; Stewart, M David; Gunaratne, Preethi; Cooney, Austin; McConnell, Bradley K; Schwartz, Robert J

    2016-01-01

    Mesp1 directs multipotential cardiovascular cell fates, even though it's transiently induced prior to the appearance of the cardiac progenitor program. Tracing Mesp1-expressing cells and their progeny allows isolation and characterization of the earliest cardiovascular progenitor cells. Studying the biology of Mesp1-CPCs in cell culture and ischemic disease models is an important initial step toward using them for heart disease treatment. Because of Mesp1's transitory nature, Mesp1-CPC lineages were traced by following EYFP expression in murine Mesp1(Cre/+); Rosa26(EYFP/+) ES cells. We captured EYFP+ cells that strongly expressed cardiac mesoderm markers and cardiac transcription factors, but not pluripotent or nascent mesoderm markers. BMP2/4 treatment led to the expansion of EYFP+ cells, while Wnt3a and Activin were marginally effective. BMP2/4 exposure readily led EYFP+ cells to endothelial and smooth muscle cells, but inhibition of the canonical Wnt signaling was required to enter the cardiomyocyte fate. Injected mouse pre-contractile Mesp1-EYFP+ CPCs improved the survivability of injured mice and restored the functional performance of infarcted hearts for at least 3 months. Mesp1-EYFP+ cells are bona fide CPCs and they integrated well in infarcted hearts and emerged de novo into terminally differentiated cardiac myocytes, smooth muscle and vascular endothelial cells. PMID:27538477

  19. Effects of ethanol on rat heart and skeletal muscles

    SciTech Connect

    Pagala, M.; Ravindran, K.; Namba, T.; Grob, D. State Univ. of New York, Brooklyn )

    1991-03-11

    Chronic alcoholism causes myopathy of both cardiac and skeletal muscles. In order to evaluate acute effects, the authors infused ethanol intravenously in anesthetized rats, and, 10 min later, monitored the electrocardiogram, and the compound action potential and isometric tension of the anterior tibialis evoked by sciatic nerve stimulation. Ethanol at 0.1, 0.2 and 0.5 g/kg decreased the heart rate by 12%, 22% and 69%, increased the P-R interval by 5%, 25%, and 116%, and reduced the QRS amplitude by 1% , 2% and 10%, respectively. Within 5 min after infusing 0.5 g/kg ethanol, breathing was stopped. Ethanol increased the amplitude of the compound action potential and tension of the anterior tibialis by 25% at 0.1 and 0.2 g/kg, while it decreased the compound action potential by 5% and tension by 35% at 0.5 g/kg. At this dose, ethanol caused 70% decrement in amplitude of the compound action potentials and 50% fade of tetanic tensions evoked by a train of nerve stimulations at 100 Hz for 0.5 sec. When ethanol was injected intraperitoneally, about 10 times greater doses were required to produce effects equivalent to intravenous administration. These results indicate that ethanol reduces cardiac output dose-dependently, and potentiates skeletal muscle function at subintoxication doses and reduces it at higher doses.

  20. Do inflammatory cells influence skeletal muscle hypertrophy?

    PubMed

    Koh, Timothy J; Pizza, Francis X

    2009-06-01

    Most research on muscle hypertrophy has focused on the responses of muscle cells to mechanical loading; however, a number of studies also suggest that inflammatory cells may influence muscle hypertrophy. Neutrophils and macrophages accumulate in skeletal muscle following increased mechanical loading, and we have demonstrated that macrophages are essential for hypertrophy following synergist ablation. Whether neutrophils are required remains to be determined. Non-steroidal anti-inflammatory drugs impair adaptive responses of skeletal muscle in both human and animal experiments suggesting that the routine use of such drugs could impair muscle performance. Much remains to be learned about the role of inflammatory cells in muscle hypertrophy, including the molecular signals involved in calling neutrophils and macrophages to skeletal muscle as well as those that regulate their function in muscle. In addition, although we have demonstrated that macrophages produce growth promoting factors during muscle hypertrophy, the full range of functional activities involved in muscle hypertrophy remains to be determined. Further investigation should provide insight into the intriguing hypothesis that inflammatory cells play integral roles in regulating muscle hypertrophy.

  1. Bone Marrow Stromal Cells Generate Muscle Cells and Repair Muscle Degeneration

    NASA Astrophysics Data System (ADS)

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

    2005-07-01

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

  2. Carbon nanotube biocompatibility with cardiac muscle cells

    NASA Astrophysics Data System (ADS)

    Garibaldi, Silvano; Brunelli, Claudio; Bavastrello, Valter; Ghigliotti, Giorgio; Nicolini, Claudio

    2006-01-01

    Purified carbon nanotubes are new carbon allotropes, sharing similarities with graphite, that have recently been proposed for their potential use with biological systems as probes for in vitro research and for diagnostic and clinical purposes. However the biocompatibility of carbon nanotubes with cells represents an important problem that, so far, remains largely uninvestigated. The objective of this in vitro study is to explore the cytocompatibility properties of purified carbon nanofibres with cardiomyocytes. Cardiac muscle cells from a rat heart cell line H9c2 (2-1) have been used. Highly purified single-walled nanotubes (SWNTs) were suspended at the concentration of 0.2 mg ml-1 by ultrasound in complete Dulbecco's modified Eagle's medium, and administered to cells to evaluate cell proliferation and shape changes by light microscopy, cell viability by trypan blue exclusion, and apoptosis, determined flow cytometrically by annexin/PI staining. Microscopic observation evidenced that carbon nanotubes bind to the cell membrane, causing a slight modification in cell shape and in cell count only after three days of treatment. Cell viability was not affected by carbon nanotubes in the first three days of culture, while after this time, cell death was slightly higher in nanotube-treated cells (p = ns). Accordingly, nanotube treatment induced little and non-significant change in the apoptotic cell number at day 1 and 3. The effect of nanotubes bound to cells was tested by reseeding treated cardiomyocytes. Cells from a trypsinized nanotube-treated sample showed a limited ability to proliferate, and a definite difference in shape, with a high degree of cell death: compared to reseeded untreated ones, in SWNT-treated samples the annexin-positive/PI-negative cells increased from 2.9% to 9.3% in SWNT (p<0.05, where p<0.05 defines a statistically significant difference with a probability above 95%), and the annexin-positive/PI-positive cells increased from 5.2% to 18.7% (p<0

  3. Programming and reprogramming a human heart cell

    PubMed Central

    Sahara, Makoto; Santoro, Federica; Chien, Kenneth R

    2015-01-01

    The latest discoveries and advanced knowledge in the fields of stem cell biology and developmental cardiology hold great promise for cardiac regenerative medicine, enabling researchers to design novel therapeutic tools and approaches to regenerate cardiac muscle for diseased hearts. However, progress in this arena has been hampered by a lack of reproducible and convincing evidence, which at best has yielded modest outcomes and is still far from clinical practice. To address current controversies and move cardiac regenerative therapeutics forward, it is crucial to gain a deeper understanding of the key cellular and molecular programs involved in human cardiogenesis and cardiac regeneration. In this review, we consider the fundamental principles that govern the “programming” and “reprogramming” of a human heart cell and discuss updated therapeutic strategies to regenerate a damaged heart. PMID:25712211

  4. Relation of systemic and local muscle exercise capacity to skeletal muscle characteristics in men with congestive heart failure

    NASA Technical Reports Server (NTRS)

    Massie, B. M.; Simonini, A.; Sahgal, P.; Wells, L.; Dudley, G. A.

    1996-01-01

    OBJECTIVES. The present study was undertaken to further characterize changes in skeletal muscle morphology and histochemistry in congestive heart failure and to determine the relation of these changes to abnormalities of systemic and local muscle exercise capacity. BACKGROUND. Abnormalities of skeletal muscle appear to play a role in the limitation of exercise capacity in congestive heart failure, but information on the changes in muscle morphology and biochemistry and their relation to alterations in muscle function is limited. METHODS. Eighteen men with predominantly mild to moderate congestive heart failure (mean +/- SEM New York Heart Association functional class 2.6 +/- 0.2, ejection fraction 24 +/- 2%) and eight age- and gender-matched sedentary control subjects underwent measurements of peak systemic oxygen consumption (VO2) during cycle ergometry, resistance to fatigue of the quadriceps femoris muscle group and biopsy of the vastus lateralis muscle. RESULTS. Peak VO2 and resistance to fatigue were lower in the patients with heart failure than in control subjects (15.7 +/- 1.2 vs. 25.1 +/- 1.5 ml/min-kg and 63 +/- 2% vs. 85 +/- 3%, respectively, both p < 0.001). Patients had a lower proportion of slow twitch, type I fibers than did control subjects (36 +/- 3% vs. 46 +/- 5%, p = 0.048) and a higher proportion of fast twitch, type IIab fibers (18 +/- 3% vs. 7 +/- 2%, p = 0.004). Fiber cross-sectional area was smaller, and single-fiber succinate dehydrogenase activity, a mitochondrial oxidative marker, was lower in patients (both p < or = 0.034). Likewise, the ratio of average fast twitch to slow twitch fiber cross-sectional area was lower in patients (0.780 +/- 0.06 vs. 1.05 +/- 0.08, p = 0.019). Peak VO2 was strongly related to integrated succinate dehydrogenase activity in patients (r = 0.896, p = 0.001). Peak VO2, resistance to fatigue and strength also correlated significantly with several measures of fiber size, especially of fast twitch fibers, in

  5. Interstitial Cells: Regulators of Smooth Muscle Function

    PubMed Central

    Sanders, Kenton M.; Ward, Sean M.; Koh, Sang Don

    2014-01-01

    Smooth muscles are complex tissues containing a variety of cells in addition to muscle cells. Interstitial cells of mesenchymal origin interact with and form electrical connectivity with smooth muscle cells in many organs, and these cells provide important regulatory functions. For example, in the gastrointestinal tract, interstitial cells of Cajal (ICC) and PDGFRα+ cells have been described, in detail, and represent distinct classes of cells with unique ultrastructure, molecular phenotypes, and functions. Smooth muscle cells are electrically coupled to ICC and PDGFRα+ cells, forming an integrated unit called the SIP syncytium. SIP cells express a variety of receptors and ion channels, and conductance changes in any type of SIP cell affect the excitability and responses of the syncytium. SIP cells are known to provide pacemaker activity, propagation pathways for slow waves, transduction of inputs from motor neurons, and mechanosensitivity. Loss of interstitial cells has been associated with motor disorders of the gut. Interstitial cells are also found in a variety of other smooth muscles; however, in most cases, the physiological and pathophysiological roles for these cells have not been clearly defined. This review describes structural, functional, and molecular features of interstitial cells and discusses their contributions in determining the behaviors of smooth muscle tissues. PMID:24987007

  6. Exercise training in chronic heart failure: improving skeletal muscle O2 transport and utilization.

    PubMed

    Hirai, Daniel M; Musch, Timothy I; Poole, David C

    2015-11-01

    Chronic heart failure (CHF) impairs critical structural and functional components of the O2 transport pathway resulting in exercise intolerance and, consequently, reduced quality of life. In contrast, exercise training is capable of combating many of the CHF-induced impairments and enhancing the matching between skeletal muscle O2 delivery and utilization (Q̇mO2 and V̇mO2 , respectively). The Q̇mO2 /V̇mO2 ratio determines the microvascular O2 partial pressure (PmvO2 ), which represents the ultimate force driving blood-myocyte O2 flux (see Fig. 1). Improvements in perfusive and diffusive O2 conductances are essential to support faster rates of oxidative phosphorylation (reflected as faster V̇mO2 kinetics during transitions in metabolic demand) and reduce the reliance on anaerobic glycolysis and utilization of finite energy sources (thus lowering the magnitude of the O2 deficit) in trained CHF muscle. These adaptations contribute to attenuated muscle metabolic perturbations (e.g., changes in [PCr], [Cr], [ADP], and pH) and improved physical capacity (i.e., elevated critical power and maximal V̇mO2 ). Preservation of such plasticity in response to exercise training is crucial considering the dominant role of skeletal muscle dysfunction in the pathophysiology and increased morbidity/mortality of the CHF patient. This brief review focuses on the mechanistic bases for improved Q̇mO2 /V̇mO2 matching (and enhanced PmvO2 ) with exercise training in CHF with both preserved and reduced ejection fraction (HFpEF and HFrEF, respectively). Specifically, O2 convection within the skeletal muscle microcirculation, O2 diffusion from the red blood cell to the mitochondria, and muscle metabolic control are particularly susceptive to exercise training adaptations in CHF. Alternatives to traditional whole body endurance exercise training programs such as small muscle mass and inspiratory muscle training, pharmacological treatment (e.g., sildenafil and pentoxifylline), and dietary

  7. Oxygen consumption of human heart cells in monolayer culture.

    PubMed

    Sekine, Kaori; Kagawa, Yuki; Maeyama, Erina; Ota, Hiroki; Haraguchi, Yuji; Matsuura, Katsuhisa; Shimizu, Tatsuya

    2014-09-26

    Tissue engineering in cardiovascular regenerative therapy requires the development of an efficient oxygen supply system for cell cultures. However, there are few studies which have examined human cardiomyocytes in terms of oxygen consumption and metabolism in culture. We developed an oxygen measurement system equipped with an oxygen microelectrode sensor and estimated the oxygen consumption rates (OCRs) by using the oxygen concentration profiles in culture medium. The heart is largely made up of cardiomyocytes, cardiac fibroblasts, and cardiac endothelial cells. Therefore, we measured the oxygen consumption of human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs), cardiac fibroblasts, human cardiac microvascular endothelial cell and aortic smooth muscle cells. Then we made correlations with their metabolisms. In hiPSC-CMs, the value of the OCR was 0.71±0.38pmol/h/cell, whereas the glucose consumption rate and lactate production rate were 0.77±0.32pmol/h/cell and 1.61±0.70pmol/h/cell, respectively. These values differed significantly from those of the other cells in human heart. The metabolism of the cells that constitute human heart showed the molar ratio of lactate production to glucose consumption (L/G ratio) that ranged between 1.97 and 2.2. Although the energy metabolism in adult heart in vivo is reported to be aerobic, our data demonstrated a dominance of anaerobic glycolysis in an in vitro environment. With our measuring system, we clearly showed the differences in the metabolism of cells between in vivo and in vitro monolayer culture. Our results regarding cell OCRs and metabolism may be useful for future tissue engineering of human heart.

  8. Satellite Cells and Skeletal Muscle Regeneration.

    PubMed

    Dumont, Nicolas A; Bentzinger, C Florian; Sincennes, Marie-Claude; Rudnicki, Michael A

    2015-07-01

    Skeletal muscles are essential for vital functions such as movement, postural support, breathing, and thermogenesis. Muscle tissue is largely composed of long, postmitotic multinucleated fibers. The life-long maintenance of muscle tissue is mediated by satellite cells, lying in close proximity to the muscle fibers. Muscle satellite cells are a heterogeneous population with a small subset of muscle stem cells, termed satellite stem cells. Under homeostatic conditions all satellite cells are poised for activation by stimuli such as physical trauma or growth signals. After activation, satellite stem cells undergo symmetric divisions to expand their number or asymmetric divisions to give rise to cohorts of committed satellite cells and thus progenitors. Myogenic progenitors proliferate, and eventually differentiate through fusion with each other or to damaged fibers to reconstitute fiber integrity and function. In the recent years, research has begun to unravel the intrinsic and extrinsic mechanisms controlling satellite cell behavior. Nonetheless, an understanding of the complex cellular and molecular interactions of satellite cells with their dynamic microenvironment remains a major challenge, especially in pathological conditions. The goal of this review is to comprehensively summarize the current knowledge on satellite cell characteristics, functions, and behavior in muscle regeneration and in pathological conditions.

  9. Types of muscle tissue (image)

    MedlinePlus

    The 3 types of muscle tissue are cardiac, smooth, and skeletal. Cardiac muscle cells are located in ... heart, appear striated, and are under involuntary control. Smooth muscle fibers are located in walls of hollow ...

  10. Satellite cells in human skeletal muscle plasticity

    PubMed Central

    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. PMID:26557092

  11. Human Engineered Heart Muscles Engraft and Survive Long-Term in a Rodent Myocardial Infarction Model

    PubMed Central

    Riegler, Johannes; Tiburcy, Malte; Ebert, Antje; Tzatzalos, Evangeline; Raaz, Uwe; Abilez, Oscar J.; Shen, Qi; Kooreman, Nigel G.; Neofytou, Evgenios; Chen, Vincent C.; Wang, Mouer; Meyer, Tim; Tsao, Philip S.; Connolly, Andrew J.; Couture, Larry A.; Gold, Joseph D.; Zimmermann, Wolfram H.; Wu, Joseph C.

    2015-01-01

    Rational Tissue engineering approaches may improve survival and functional benefits from human embryonic stem cell-derived cardiomyocte (ESC-CM) transplantation, thereby potentially preventing dilative remodelling and progression to heart failure. Objective Assessment of transport stability, long term survival, structural organisation, functional benefits, and teratoma risk of engineered heart muscle (EHM) in a chronic myocardial infarction (MI) model. Methods and Results We constructed EHMs from ESC-CMs and released them for transatlantic shipping following predefined quality control criteria. Two days of shipment did not lead to adverse effects on cell viability or contractile performance of EHMs (n=3, P=0.83, P=0.87). After ischemia/reperfusion (I/R) injury, EHMs were implanted onto immunocompromised rat hearts at 1 month to simulate chronic ischemia. Bioluminescence imaging (BLI) showed stable engraftment with no significant cell loss between week 2 and 12 (n=6, P=0.67), preserving up to 25% of the transplanted cells. Despite high engraftment rates and attenuated disease progression (change in ejection fraction for EHMs −6.7±1.4% vs control −10.9±1.5%, n>12, P=0.05), we observed no difference between EHMs containing viable or non-viable human cardiomyocytes in this chronic xenotransplantation model (n>12, P=0.41). Grafted cardiomyocytes showed enhanced sarcomere alignment and increased connexin 43 expression at 220 days after transplantation. No teratomas or tumors were found in any of the animals (n=14) used for long-term monitoring. Conclusions EHM transplantation led to high engraftment rates, long term survival, and progressive maturation of human cardiomyocytes. However, cell engraftment was not correlated with functional improvements in this chronic MI model. Most importantly, the safety of this approach was demonstrated by the lack of tumor or teratoma formation. PMID:26291556

  12. Toad heart utilizes exclusively slow skeletal muscle troponin T: an evolutionary adaptation with potential functional benefits.

    PubMed

    Feng, Han-Zhong; Chen, Xuequn; Hossain, M Moazzem; Jin, Jian-Ping

    2012-08-24

    The three isoforms of vertebrate troponin T (TnT) are normally expressed in a muscle type-specific manner. Here we report an exception that the cardiac muscle of toad (Bufo) expresses exclusively slow skeletal muscle TnT (ssTnT) together with cardiac forms of troponin I and myosin as determined using immunoblotting, cDNA cloning, and/or LC-MS/MS. Using RT-PCR and 3'- and 5'-rapid amplification of cDNA ends on toad cardiac mRNA, we cloned full-length cDNAs encoding two alternatively spliced variants of ssTnT. Expression of the cloned cDNAs in Escherichia coli confirmed that the toad cardiac muscle expresses solely ssTnT, predominantly the low molecular weight variant with the exon 5-encoded NH(2)-terminal segment spliced out. Functional studies were performed in ex vivo working toad hearts and compared with the frog (Rana) hearts. The results showed that toad hearts had higher contractile and relaxation velocities and were able to work against a significantly higher afterload than that of frog hearts. Therefore, the unique evolutionary adaptation of utilizing exclusively ssTnT in toad cardiac muscle corresponded to a fitness value from improving systolic function of the heart. The data demonstrated a physiological importance of the functional diversity of TnT isoforms. The structure-function relationship of TnT may be explored for the development of new treatment of heart failure.

  13. Toad heart utilizes exclusively slow skeletal muscle troponin T: an evolutionary adaptation with potential functional benefits.

    PubMed

    Feng, Han-Zhong; Chen, Xuequn; Hossain, M Moazzem; Jin, Jian-Ping

    2012-08-24

    The three isoforms of vertebrate troponin T (TnT) are normally expressed in a muscle type-specific manner. Here we report an exception that the cardiac muscle of toad (Bufo) expresses exclusively slow skeletal muscle TnT (ssTnT) together with cardiac forms of troponin I and myosin as determined using immunoblotting, cDNA cloning, and/or LC-MS/MS. Using RT-PCR and 3'- and 5'-rapid amplification of cDNA ends on toad cardiac mRNA, we cloned full-length cDNAs encoding two alternatively spliced variants of ssTnT. Expression of the cloned cDNAs in Escherichia coli confirmed that the toad cardiac muscle expresses solely ssTnT, predominantly the low molecular weight variant with the exon 5-encoded NH(2)-terminal segment spliced out. Functional studies were performed in ex vivo working toad hearts and compared with the frog (Rana) hearts. The results showed that toad hearts had higher contractile and relaxation velocities and were able to work against a significantly higher afterload than that of frog hearts. Therefore, the unique evolutionary adaptation of utilizing exclusively ssTnT in toad cardiac muscle corresponded to a fitness value from improving systolic function of the heart. The data demonstrated a physiological importance of the functional diversity of TnT isoforms. The structure-function relationship of TnT may be explored for the development of new treatment of heart failure. PMID:22778265

  14. The expression of lactate transporters (MCT1 and MCT4) in heart and muscle.

    PubMed

    Bonen, A

    2001-11-01

    It is now known that lactate traverses the plasma membrane of many tissues, including heart and muscle, via a stereo-specific, pH-dependent monocarboxylate transport (MCT) system. In the past few years a family of MCTs (MCT1-MCT7) has been cloned. Transcripts of MCT1 and MCT4 are detectable in rat and human skeletal muscle and in the heart. However, only skeletal muscle expresses both the MCT1 and MCT4 proteins, whereas rat heart expresses the MCTI, but not the MCT4 protein. The kinetic activities of MCT1(Km=3.5 mM) and MCT4 (Km= 17-34 mM) are quite different. Among rat muscles, MCT1 expression is highly correlated with the oxidative fiber composition of the muscle, and other indices of oxidative metabolism. Lactate uptake from the circulation is also highly correlated with the MCT1 content of muscles. MCT4 is confined to fast-twitch (fast glycolytic and fast oxidative glycolytic) muscle fibers, in which MCT4 content is correlated with indices of anaerobic metabolism. Collectively, these data suggest that MCT1 and MCT4 are primarily responsible for lactate uptake from the circulation and lactate extrusion out of muscle, respectively. Exercise training can increase the expression of both MCT1 and MCT4 in human muscle, although the extent of this up-regulation may be related to the intensity of training. In the rat heart, MCT1 expression is induced more easily by exercise training than in rat skeletai muscle. It appears that MCT1 and MCT4 expression are regulated in a tissue-specific and isoform-specific manner. Therefore, skeletal muscle lactate concentrations are not only regulated by the rate of glycolysis, but also by the efficiency of trans-sarcolemmal lactate transport, a process that is regulated by the quantity of available MCT proteins.

  15. Activated Muscle Satellite Cells Chase Ghosts.

    PubMed

    Mourikis, Philippos; Relaix, Frédéric

    2016-02-01

    The in vivo behaviors of skeletal muscle stem cells, i.e., satellite cells, during homeostasis and after injury are poorly understood. In this issue of Cell Stem Cell, Webster et al. (2016) now perform a tour de force intravital microscopic analysis of this population, showing that "ghost fiber" remnants act as scaffolds to guide satellite cell divisions after injury. PMID:26849298

  16. FA composition of heart and skeletal muscle during embryonic development of the king penguin.

    PubMed

    Decrock, Frederic; Groscolas, Rene; Speake, Brian K

    2002-04-01

    Since the yolk lipids of the king penguin (Aptenodytes patagonicus) naturally contain the highest concentrations of DHA and EPA yet reported for the eggs of any avian species, the effects of this (n-3)-rich yolk on the FA profiles of the embryonic heart and skeletal muscle were investigated. The concentrations (mg/g wet tissue) of phospholipid (PL) in the developing heart and leg muscle of the penguin doubled between days 27 and 55 from the beginning of egg incubation (i.e., from the halfway stage of embryonic development to 2 d posthatch), whereas no net increase occurred in pectoral muscle. During this period, the concentration of TAG in heart decreased by half but increased two- and sixfold in leg and pectoral muscle, respectively. The most notable change in cholesteryl ester concentration occurred in pectoral muscle, increasing ninefold between days 27 and 55. Arachidonic acid (ARA) was the major polyunsaturate in PL of the penguin's heart, where it formed about 20% (w/w) of FA at day 55. At the equivalent developmental stage, the heart PL of the chicken contained a 1.3-fold greater proportion of ARA, contained a fifth less DHA, and was almost devoid of EPA, whereas the latter FA was a significant component (7% of FA) of penguin heart PL. Similarly, in PL of leg and pectoral muscle, the chicken displayed about 1.4-fold more ARA, up to 50% less DHA, and far less EPA in comparison with the penguin. Thus, although ARA-rich PL profiles are achieved in the heart and muscle of the penguin embryo, these profiles are significantly affected by the high n-3 content of the yolk. PMID:12030322

  17. Gene expression changes controlling distinct adaptations in the heart and skeletal muscle of a hibernating mammal.

    PubMed

    Vermillion, Katie L; Anderson, Kyle J; Hampton, Marshall; Andrews, Matthew T

    2015-03-01

    Throughout the hibernation season, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) experiences extreme fluctuations in heart rate, metabolism, oxygen consumption, and body temperature, along with prolonged fasting and immobility. These conditions necessitate different functional requirements for the heart, which maintains contractile function throughout hibernation, and the skeletal muscle, which remains largely inactive. The adaptations used to maintain these contractile organs under such variable conditions serves as a natural model to study a variety of medically relevant conditions including heart failure and disuse atrophy. To better understand how two different muscle tissues maintain function throughout the extreme fluctuations of hibernation we performed Illumina HiSeq 2000 sequencing of cDNAs to compare the transcriptome of heart and skeletal muscle across the circannual cycle. This analysis resulted in the identification of 1,076 and 1,466 differentially expressed genes in heart and skeletal muscle, respectively. In both heart and skeletal muscle we identified a distinct cold-tolerant mechanism utilizing peroxisomal metabolism to make use of elevated levels of unsaturated depot fats. The skeletal muscle transcriptome also shows an early increase in oxidative capacity necessary for the altered fuel utilization and increased oxygen demand of shivering. Expression of the fetal gene expression profile is used to maintain cardiac tissue, either through increasing myocyte size or proliferation of resident cardiomyocytes, while skeletal muscle function and mass are protected through transcriptional regulation of pathways involved in protein turnover. This study provides insight into how two functionally distinct muscles maintain function under the extreme conditions of mammalian hibernation.

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

    PubMed

    Li, Bo-Jiang; Li, Ping-Hua; Huang, Rui-Hua; Sun, Wen-Xing; Wang, Han; Li, Qi-Fa; Chen, Jie; Wu, Wang-Jun; Liu, Hong-Lin

    2015-08-01

    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.

  19. Cell therapy for ischaemic heart disease: focus on the role of resident cardiac stem cells.

    PubMed

    Chamuleau, S A J; Vrijsen, K R; Rokosh, D G; Tang, X L; Piek, J J; Bolli, R

    2009-05-01

    Myocardial infarction results in loss of cardiomyocytes, scar formation, ventricular remodelling, and eventually heart failure. In recent years, cell therapy has emerged as a potential new strategy for patients with ischaemic heart disease. This includes embryonic and bone marrow derived stem cells. Recent clinical studies showed ostensibly conflicting results of intracoronary infusion of autologous bone marrow derived stem cells in patients with acute or chronic myocardial infarction. Anyway, these results have stimulated additional clinical and pre-clinical studies to further enhance the beneficial effects of stem cell therapy. Recently, the existence of cardiac stem cells that reside in the heart itself was demonstrated. Their discovery has sparked intense hope for myocardial regeneration with cells that are obtained from the heart itself and are thereby inherently programmed to reconstitute cardiac tissue. These cells can be detected by several surface markers (e.g. c-kit, Sca-1, MDR1, Isl-1). Both in vitro and in vivo differentiation into cardiomyocytes, endothelial cells and vascular smooth muscle cells has been demonstrated, and animal studies showed promising results on improvement of left ventricular function. This review will discuss current views regarding the feasibility of cardiac repair, and focus on the potential role of the resident cardiac stem and progenitor cells. (Neth Heart J 2009;17:199-207.).

  20. Stem cells in the diabetic infarcted heart

    PubMed Central

    Glass, Carley E.; Singal, Pawan K.

    2010-01-01

    Diabetes mellitus is one of the leading causes of death, and the majority of these deaths are associated with cardiovascular diseases. Development and progression of myocardial infarction leading to heart failure is much more complex and multifactorial in diabetics compared with non-diabetics. Despite significant advances in pharmacological interventions and surgical techniques, the disease progression leading to diabetic end-stage heart failure remains very high. Recently, cell therapy has gained much attention as an alternative approach to treat various heart diseases. However, transplanted stem cell studies in diabetic animal models are very limited. In this review, we discuss the pathogenesis of the diabetic infarcted heart and the potential of stem cell therapy to repair and regenerate. PMID:20559720

  1. Effect of ethanol on function of the rat heart and skeletal muscles.

    PubMed

    Pagala, M; Ravindran, K; Amaladevi, B; Namba, T; Grob, D

    1995-06-01

    The present study was undertaken to evaluate the acute effects of ethanol on responses of the rat heart and skeletal muscles both in vivo and in vitro. In the anesthetized rat, intravenous infusion of ethanol at 0.1-0.5 g/kg body weight (33-167 mM) decreased the breathing rate by 8-83%, heart rate by 4-52%, and QRS amplitude by 5-27%, and increased the P-R interval by 1-49%. In the anterior tibialis muscle subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, ethanol at 0.1 g/kg increased the amplitude of the muscle action potential (AP) by 7%, whereas at 0.5 g/kg it decreased the muscle AP by 32%. The nerve-evoked tetanic tension was reduced by 7-34% at 0.1-0.5 g/kg ethanol. In the isolated rat heart, perfusion of ethanol at 0.1-3.0% (22-651 mM) decreased the heart rate by 8-48% and QRS amplitude by 10-39%, and increased the P-R interval by 5-61%. Left ventricular pressure was increased by 10% at 0.1% ethanol, and decreased by 80% at 3.0% ethanol. In the isolated rat phrenic nerve-diaphragm muscle preparation subjected to repetitive nerve stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the nerve AP by 5-89%, nerve-evoked muscle AP by 2-96%, and peak tetanic tension by 1-87%. On repetitive direct muscle stimulation at 100 Hz for 0.5 sec, 0.1-3.0% ethanol decreased the amplitude of the muscle-evoked muscle AP by 8-65%, and muscle-evoked tetanic tension by 2-65%. These studies indicate that ethanol causes smaller reduction in responses of the heart and skeletal muscles at clinical concentrations, but marked reduction in these responses at higher concentrations due to direct action on excitability of these tissues. At higher concentrations, ethanol causes greater reduction in excitability of the skeletal muscle than of the heart. PMID:7573793

  2. Muscle Cells Provide Instructions for Planarian Regeneration

    PubMed Central

    Witchley, Jessica N.; Mayer, Mirjam; Wagner, Daniel E.; Owen, Jared H.; Reddien, Peter W.

    2014-01-01

    Regeneration requires both potential and instructions for tissue replacement. In planarians, pluripotent stem cells have the potential to produce all new tissue. The identities of the cells that provide regeneration instructions are unknown. Here, we report that position control genes (PCGs) that control regeneration and tissue turnover are expressed in a subepidermal layer of nonneoblast cells. These subepidermal cells coexpress many PCGs. We propose that these subepidermal cells provide a system of body coordinates and positional information for regeneration, and identify them to be muscle cells of the planarian body wall. Almost all planarian muscle cells express PCGs, suggesting a dual function: contraction and control of patterning. PCG expression is dynamic in muscle cells after injury, even in the absence of neoblasts, suggesting that muscle is instructive for regeneration. We conclude that planarian regeneration involves two highly flexible systems: pluripotent neoblasts that can generate any new cell type and muscle cells that provide positional instructions for the regeneration of any body region. PMID:23954785

  3. Transmembrane chloride flux in tissue-cultured chick heart cells

    SciTech Connect

    Piwnica-Worms, D.; Jacob, R.; Horres, C.R.; Lieberman, M.

    1983-05-01

    To evaluate the transmembrane movement of chloride in a preparation of cardiac muscle lacking the extracellular diffusion limitations of natural specimens, intracellular chloride concentration ( (Cl) i) and transmembrane /sup 36/Cl efflux have been determined in growth-oriented embryonic chick heart cells in tissue culture. Using the method of isotopic equilibrium, (Cl)i was 25.1 +/- 7.3 mmol x (liter cell water)-1, comparable to the value of 24.9 +/- 5.4 mmol x (liter cell water)-1 determined by coulometric titration. Two cellular /sup 36/Cl compartments were found; one exchanged with a rate constant of 0.67 +/- 0.12 min-1 and was associated with the cardiac muscle cells; the other, attributed to the fibroblasts, exchanged with a rate constant of 0.18 +/- 0.05 min-1. At 37 degrees C, transmembrane Cl flux of cardiac muscle under steady-state conditions was 30 pmol x cm-2 x s-1. In K-free, normal, or high-Ko solutions, the responses of the membrane potential to changes in external Cl concentration suggested that chloride conductance was low. These results indicate that Cl transport across the myocardial cell membrane is more rapid than K transport and is largely electrically silent.

  4. Disability in COPD and Chronic Heart Failure Is the Skeletal Muscle the Final Common Pathway?

    PubMed Central

    DUMITRU, Luminita; ILIESCU, Alina; DINU, Horatiu; BADEA, Ruxandra; SAVULESCU, Simona; HUIDU, Simona; BERTEANU, Mihai

    2013-01-01

    ABSTRACT Chronic Obstructive Pulmonary Disease (COPD) and Chronic Heart Failure (CHF), two major causes of worldwide morbidity and mortality have important systemic components, affecting additional tissues, other than the lung or the heart, such as the skeletal muscle. Muscle function (or dysfunction) may not only influence the symptoms that limit exercise, but may contribute directly to the poor exercise performance, health status and increased healthcare utilization. The present review tries to summarize the muscular abnormalities in COPD and CHF and the mechanisms underlying these alterations, which are strikingly similar, despite the obvious differences concerning the primary impairment in these two chronic diseases. The muscles therefore represent a potential site to improve patients' functioning level and quality of life of COPD and CHF. Only one practical therapeutic intervention currently exists that can reverse some of the muscle abnormalities observed in COPD and CHF, namely exercise training, which becomes nowadays the "cornerstone" of the whole rehabilitation. PMID:24371487

  5. Muscle cell attachment in Caenorhabditis elegans

    PubMed Central

    1991-01-01

    In the nematode Caenorhabditis elegans, the body wall muscles exert their force on the cuticle to generate locomotion. Interposed between the muscle cells and the cuticle are a basement membrane and a thin hypodermal cell. The latter contains bundles of filaments attached to dense plaques in the hypodermal cell membranes, which together we have called a fibrous organelle. In an effort to define the chain of molecules that anchor the muscle cells to the cuticle we have isolated five mAbs using preparations enriched in these components. Two antibodies define a 200-kD muscle antigen likely to be part of the basement membrane at the muscle/hypodermal interface. Three other antibodies probably identify elements of the fibrous organelles in the adjacent hypodermis. The mAb IFA, which reacts with mammalian intermediate filaments, also recognizes these structures. We suggest that the components recognized by these antibodies are likely to be involved in the transmission of tension from the muscle cell to the cuticle. PMID:1860880

  6. Cell therapy in congestive heart failure*

    PubMed Central

    Tao, Ze-wei; Li, Long-gui

    2007-01-01

    Congestive heart failure (CHF) has emerged as a major worldwide epidemic and its main causes seem to be the aging of the population and the survival of patients with post-myocardial infarction. Cardiomyocyte dropout (necrosis and apoptosis) plays a critical role in the progress of CHF; thus treatment of CHF by exogenous cell implantation will be a promising medical approach. In the acute phase of cardiac damage cardiac stem cells (CSCs) within the heart divide symmetrically and/or asymmetrically in response to the change of heart homeostasis, and at the same time homing of bone marrow stem cells (BMCs) to injured area is thought to occur, which not only reconstitutes CSC population to normal levels but also repairs the heart by differentiation into cardiac tissue. So far, basic studies by using potential sources such as BMCs and CSCs to treat animal CHF have shown improved ventricular remodelling and heart function. Recently, however, a few of randomized, double-blind, placebo-controlled clinical trials demonstrated mixed results in heart failure with BMC therapy during acute myocardial infarction. PMID:17726746

  7. Arterial wall mechanics as a function of heart rate: role of vascular smooth muscle

    NASA Astrophysics Data System (ADS)

    Salvucci, Fernando Pablo; Schiavone, Jonathan; Craiem, Damian; Barra, Juan Gabriel

    2007-11-01

    Vascular wall viscoelasticity can be evaluated using a first-order lumped model. This model consists of a spring with elastic constant E and a dashpot with viscous constant η. More importantly, this viscoelastic model can be fitted in-vivo measuring arterial pressure and diameter. The aim of this work is to analyze the influence of heart rate over E and η. In two anesthetized sheep, diameter in thoracic aorta and intravascular pressure has been registered. The right atrium was connected to a programmable stimulator through a pair of pace-maker wires to produce changes in stimulation heart rate (HR) from 80 to 160 bpm. Additionally, local activation of vascular smooth muscle was induced with phenylephrine. After converting pressure and diameter signals into stress and strain respectively, E y η were calculated in control state and during muscle activation. The elastic modulus E did not present significant changes with heart rate. The viscous modulus η decreased 49% with a two-fold acceleration in heart rate from 80 to 160 bpm. However, the product η HR remained stable. The viscous modulus η increased 39% with smooth muscle activation. No significant pressure changes were registered during the experiment. The contractile action of vascular smooth muscle could contribute to increasing arterial wall viscosity. The decrease of η when HR increased might be related to smooth muscle relaxation mediated by endothelium activity, which was stimulated by flow increase. We conclude that HR can modulate arterial wall viscoelasticity through endothelium-dependent mechanisms.

  8. Strength improvement of knee extensor muscles in patients with chronic heart failure by neuromuscular electrical stimulation.

    PubMed

    Quittan, M; Sochor, A; Wiesinger, G F; Kollmitzer, J; Sturm, B; Pacher, R; Mayr, W

    1999-05-01

    Patients with severe chronic heart failure (CHF) suffer from marked weakness of skeletal muscles. Neuromuscular electrical stimulation (NMES) proved to be an alternative to active strength training. The objective of this study was to test the feasibility and effectiveness of NMES in patients with chronic heart failure. Seven patients (56.0 +/- 5.0 years, CHF for 20 +/- 4 months, left ventricular ejection fraction 20.1 +/- 10.0%) finished an 8 week course of NMES of the knee extensor muscles. The stimulator delivered biphasic, symmetric, constant voltage impulses of 0.7 ms pulse width with a frequency of 50 Hz, 2 s on and 6 s off. No adverse effects occurred. After the stimulation period, the isokinetic peak torque of the knee extensor muscles increased by 13% from 101.0 +/- 8.7 Nm to 113.5 +/- 7.2 Nm (p = 0.004). The maximal isometric strength increased by 20% from 294.3 +/- 19.6 N to 354.14 +/- 15.7 N (p = 0.04). This increased muscle strength could be maintained in a 20 min fatigue test indicating decreased muscle fatigue. These results demonstrate that NMES of skeletal muscles in patients with severe chronic heart failure is a promising method for strength training in this group of patients.

  9. Effect of streptomycin on the active force of bioengineered heart muscle in response to controlled stretch.

    PubMed

    Birla, R K; Huang, Y C; Dennis, R G

    2008-01-01

    In this study, we describe a bioreactor system to deliver controlled stretch protocols to bioengineered heart muscle (BEHMs) and test the system when streptomycin (an aminoglycoside antibiotic, which blocks stretch-activated channels) is either added to or excluded from the culture medium. Streptomycin is a very commonly used component of cell culture antibiotic-antimycotic media additives, so its effects on muscle development and functional response to mechanical signals in vitro is worthy of investigation. Our hypothesis is that BEHMs will not adapt to the applied mechanical stretch protocol when streptomycin is present in the culture medium, but will do so when streptomycin is excluded. Bioengineered heart muscles were formed by culturing primary neonatal cardiac myocytes in a fibrin gel using a method previously developed in our laboratory. A custom bioreactor system was designed using SolidWorks and structural components manufactured using fusion deposition modeling. We utilized a stretch protocol of 1 Hz, 10% strain for 7 d. BEHMs were stretched in the presence and absence of streptomycin. As controls, BEHMs were maintained in a cell culture incubator with and without streptomycin. The contractile properties of all BEHMs were evaluated to determine the active force. We were able to demonstrate compatibility of the bioreactor system with BEHMs and were able to stretch 58 constructs with zero incidence of failure. When the BEHMs were stretched in the absence of streptomycin, the active force increased from a mean value of 51.7 +/- 5.6 (N = 10) to 102.4 +/- 16.3 microN (N = 10), with p < 0.05. However, BEHMs that were stretched in the presence of streptomycin did not show any significant increase in active force generation. The average active force of BEHMs increased from a mean value of 57.6 +/- 10.2 (N = 10) to 91.4 +/- 19.8 microN (N = 10) when stretched in the presence of streptomycin. In this study, we demonstrate compatibility of the a bioreactor system

  10. AN EXPERIMENTAL INVESTIGATION OF THE TREATMENT OF WOUNDS OF THE HEART BY MEANS OF SUTURE OF THE HEART MUSCLE

    PubMed Central

    Elsberg, Charles A.

    1899-01-01

    It would, of course, be incorrect to attempt to draw conclusions as to the dangers and the chances of success of suture of cardiac wounds in man from the results obtained by animal experimentation. Animals are placed in very unfavorable conditions after the operation. They are very restless and cannot be kept quiet. Ideal cleanliness is impossible and the animals may infect their wound by rubbing the external wound against the dirt on the floor of their cage. From the animal mortality in these investigations no rigid inferences applicable to human beings can therefore be made. Some conclusions of importance can, however, be drawn. Above all, my experiments seem to show that the mammalian heart will bear a much greater amount of manipulation than has hitherto been suspected. Very large wounds of the heart can heal and the healing process occurs in a manner entirely analogous to that in other muscular tissues. Even an extensive suture of the heart-wall of rabbits and dogs, although we know that thereby a large number of muscle fibres are destroyed and replaced by connective tissue, does not interfere with the function of the cardiac muscle as a whole. Can some of the results in the above recorded experiments be, with some restrictions of course, applied to the human heart? I think that this question must be answered in the affirmative. If we compare the knowledge we possess of wounds of the heart in man, with that obtained from animal experiments, and find that they agree in all essential particulars, then we are justified in reasoning by analogy that suture of wounds of the heart in man will give results similar to those obtained in the animal. In the last few decades, the advances made in all the branches of medicine—especially in pathology, bacteriology and surgery—have been due to a great extent to the generalization of the results of animal experimentation. To the careful and critical investigator, the results obtained in the animal experiment have always

  11. Migration of Airway Smooth Muscle Cells

    PubMed Central

    Gerthoffer, William T.

    2008-01-01

    Migration of smooth muscle cells is a process fundamental to development of hollow organs, including blood vessels and the airways. Migration is also thought to be part of the response to tissue injury. It has also been suggested to contribute to airways remodeling triggered by chronic inflammation. In both nonmuscle and smooth muscle cells numerous external signaling molecules and internal signal transduction pathways contribute to cell migration. The review includes evidence for the functional significance of airway smooth muscle migration, a summary of promigratory and antimigratory agents, and summaries of important signaling pathways mediating migration. Important signaling pathways and effector proteins described include small G proteins, phosphatidylinositol 3-kinases (PI3-K), Rho activated protein kinase (ROCK), p21-activated protein kinases (PAK), Src family tyrosine kinases, and mitogen-activated protein kinases (MAPK). These signaling modules control multiple critical effector proteins including actin nucleating, capping and severing proteins, myosin motors, and proteins that remodel microtubules. Actin filament remodeling, focal contact remodeling and propulsive force of molecular motors are all coordinated to move cells along gradients of chemical cues, matrix adhesiveness, or matrix stiffness. Airway smooth muscle cell migration can be modulated in vitro by drugs commonly used in pulmonary medicine including β-adrenergic agonists and corticosteroids. Future studies of airway smooth muscle cell migration may uncover novel targets for drugs aimed at modifying airway remodeling. PMID:18094091

  12. Spectrum of Ventricular Arrhythmias Arising from Papillary Muscle in the Structurally Normal Heart.

    PubMed

    Naksuk, Niyada; Kapa, Suraj; Asirvatham, Samuel J

    2016-09-01

    Papillary muscle is an endocavitary structure that can give rise to ventricular arrhythmias in a structurally normal heart. Its manifestation is generally benign. The papillary muscle's complex anatomy and the presence of intermixed Purkinje fibers can create a substrate for idiopathic ventricular fibrillation. Although differentiating ventricular arrhythmias originating from the papillary muscle and the fascicles is challenging and not always possible, the distinction may be helpful for planning ablation. The propensity for difficulty with ablation of papillary arrhythmias results in a variable success rate. Improvement in techniques to stabilize the catheter, use of imaging, and methods of energy delivery are required to improve ablation outcomes.

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

    PubMed

    Whitesell, Thomas R; Kennedy, Regan M; Carter, Alyson D; Rollins, Evvi-Lynn; Georgijevic, Sonja; Santoro, Massimo M; Childs, Sarah J

    2014-01-01

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

  14. Gene and cell therapy for heart failure.

    PubMed

    de Muinck, Ebo D

    2009-08-01

    Cardiac gene and cell therapy have both entered clinical trials aimed at ameliorating ventricular dysfunction in patients with chronic congestive heart failure. The transduction of myocardial cells with viral constructs encoding a specific cardiomyocyte Ca(2+) pump in the sarcoplasmic reticulum (SR), SRCa(2+)-ATPase has been shown to correct deficient Ca(2+) handling in cardiomyocytes and improvements in contractility in preclinical studies, thus leading to the first clinical trial of gene therapy for heart failure. In cell therapy, it is not clear whether beneficial effects are cell-type specific and how improvements in contractility are brought about. Despite these uncertainties, a number of clinical trials are under way, supported by safety and efficacy data from trials of cell therapy in the setting of myocardial infarction. Safety concerns for gene therapy center on inflammatory and immune responses triggered by viral constructs, and for cell therapy with myoblast cells, the major concern is increased incidence of ventricular arrhythmia after cell transplantation. Principles and mechanisms of action of gene and cell therapy for heart failure are discussed, together with the potential influence of reactive oxygen species on the efficacy of these treatments and the status of myocardial-delivery techniques for viral constructs and cells.

  15. Neuroblastoma cell lines showing smooth muscle cell phenotypes.

    PubMed

    Sugimoto, T; Mine, H; Horii, Y; Takahashi, K; Nagai, R; Morishita, R; Komada, M; Asada, Y; Sawada, T

    2000-12-01

    Neuroblastoma is a tumor that is derived from the neural crest. Recent studies demonstrated that several human neuroblastoma cell lines exhibit at least three morphologic types: neuroblastic (N)-type, substrate-adhesive (S)-type and intermediate (I)-type cells. However, the origin of the S-type cells has not been clearly identified. In this study, the expressions of smooth muscle-specific proteins (desmin, alpha-smooth muscle actin, basic calponin and the smooth muscle myosin heavy-chain isoforms of SM1 and SM2) in three parent and four cloned neuroblastoma cell lines, composed of S-type cells, were examined by indirect immunofluorescence, Western blot and/or by reverse transcription-polymerase chain reaction (RT-PCR). Desmin was found in two of the seven cell lines, and alpha-smooth muscle actin and basic calponin were detected in all of seven of the cell lines. In three parent cell lines and one cloned cell line composed of N-type cells, none of three smooth muscle-specific proteins were detected. In smooth muscle myosin heavy-chain isoforms, SM1 was detected in two parent cell lines composed of S-type cells (MP-N-MS and KP-N-YS) by immunofluorescence, Western blot and/or by RT-PCR, whereas the SM2 isoform was detected in one parent cell line (MP-N-MS) by RT-PCR. These findings indicate that S-type cells have either the immature or mature smooth muscle cell phenotype, and neural crest cells very likely have the ability of to differentiate into smooth muscle cells in the human system.

  16. Satellite Cells and the Muscle Stem Cell Niche

    PubMed Central

    Yin, Hang; Price, Feodor

    2013-01-01

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

  17. Different alterations in the insulin-stimulated glucose uptake in the athlete's heart and skeletal muscle.

    PubMed Central

    Nuutila, P; Knuuti, M J; Heinonen, O J; Ruotsalainen, U; Teräs, M; Bergman, J; Solin, O; Yki-Järvinen, H; Voipio-Pulkki, L M; Wegelius, U

    1994-01-01

    Physical training increases skeletal muscle insulin sensitivity. Since training also causes functional and structural changes in the myocardium, we compared glucose uptake rates in the heart and skeletal muscles of trained and untrained individuals. Seven male endurance athletes (VO2max 72 +/- 2 ml/kg/min) and seven sedentary subjects matched for characteristics other than VO2max (43 +/- 2 ml/kg/min) were studied. Whole body glucose uptake was determined with a 2-h euglycemic hyperinsulinemic clamp, and regional glucose uptake in femoral and arm muscles, and myocardium using 18F-fluoro-2-deoxy-D-glucose and positron emission tomography. Glucose uptake in the athletes was increased by 68% in whole body (P < 0.0001), by 99% in the femoral muscles (P < 0.01), and by 62% in arm muscles (P = 0.06), but it was decreased by 33% in the heart muscle (P < 0.05) as compared with the sedentary subjects. The total glucose uptake rate in the heart was similar in the athletes and control subjects. Left ventricular mass in the athletes was 79% greater (P < 0.001) and the meridional wall stress smaller (P < 0.001) as estimated by echocardiography. VO2max correlated directly with left ventricular mass (r = 0.87, P < 0.001) and inversely with left ventricular wall stress (r = -0.86, P < 0.001). Myocardial glucose uptake correlated directly with the rate-pressure product (r = 0.75, P < 0.02) and inversely with left ventricular mass (r = -0.60, P < 0.05) or with the whole body glucose disposal (r = -0.68, P < 0.01). Thus, in athletes, (a) insulin-stimulated glucose uptake is enhanced in the whole body and skeletal muscles, (b) whereas myocardial glucose uptake per muscle mass is reduced possibly due to decreased wall stress and energy requirements or the use of alternative fuels, or both. Images PMID:8182160

  18. Skeletal muscle mass and exercise performance in stable ambulatory patients with heart failure.

    PubMed

    Lang, C C; Chomsky, D B; Rayos, G; Yeoh, T K; Wilson, J R

    1997-01-01

    The purpose of this study was to determine whether skeletal muscle atrophy limits the maximal exercise capacity of stable ambulatory patients with heart failure. Body composition and maximal exercise capacity were measured in 100 stable ambulatory patients with heart failure. Body composition was assessed by using dual-energy X-ray absorption. Peak exercise oxygen consumption (VO2peak) and the anaerobic threshold were measured by using a Naughton treadmill protocol and a Medical Graphics CardioO2 System. VO2peak averaged 13.4 +/- 3.3 ml.min-1.kg-1 or 43 +/- 12% of normal. Lean body mass averaged 52.9 +/- 10.5 kg and leg lean mass 16.5 +/- 3.6 kg. Leg lean mass correlated linearly with VO2peak (r = 0.68, P < 0.01), suggesting that exercise performance is influences by skeletal muscle mass. However, lean body mass was comparable to levels noted in 1,584 normal control subjects, suggesting no decrease in muscle mass. Leg muscle mass was comparable to levels noted in 34 normal control subjects, further supporting this conclusion. These findings suggest that exercise intolerance in stable ambulatory patients with heart failure is not due to skeletal muscle atrophy.

  19. Extracellular matrix components direct porcine muscle stem cell behavior

    SciTech Connect

    Wilschut, Karlijn J.; Haagsman, Henk P.; Roelen, Bernard A.J.

    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.

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

    PubMed Central

    Nogueira, Julia Meireles; Hawrot, Katarzyna; Sharpe, Colin; Noble, Anna; Wood, William M.; Jorge, Erika C.; Goldhamer, David J.; Kardon, Gabrielle; Dietrich, Susanne

    2015-01-01

    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 toward 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. PMID:26042028

  1. Subclinical cardiac dysfunction in acromegaly: evidence for a specific disease of heart muscle.

    PubMed

    Rodrigues, E A; Caruana, M P; Lahiri, A; Nabarro, J D; Jacobs, H S; Raftery, E B

    1989-09-01

    Acromegaly is associated with an increased cardiac morbidity and mortality, but it is not clear whether this is the result of increased incidence of hypertension and coronary heart disease or of a specific disease of heart muscle. Thirty four acromegalic patients were studied by non-invasive techniques. Seven of these patients had raised plasma concentrations of growth hormone at the time of study; three were newly diagnosed and had not received any treatment. Hypertension was present in nine (26%) but only three (9%) had electrocardiographic left ventricular hypertrophy. Echocardiography showed ventricular hypertrophy in 12 (48%) and increased left ventricular mass in 17 (68%) patients. Holter monitoring detected important ventricular arrhythmias in 14 patients. Thallium-201 scanning showed evidence for coronary heart disease in eight patients. Systolic time intervals were normal except when there was coexistent ischaemic heart disease. A comparison between 19 acromegalic patients with no other detectable cause of heart disease and 22 age matched controls showed appreciably abnormal left ventricular diastolic function in the group with acromegaly. The abnormalities shown did not correlate with left ventricular mass or wall thickness. There was no difference in diastolic function between patients with active acromegaly and those with treated acromegaly. Hypertensive acromegalic patients had worse diastolic function than hypertensive controls, suggesting that hypertension may further impair the left ventricular diastolic abnormality in acromegaly. This is the first study to find evidence of subclinical cardiac diastolic dysfunction in acromegaly and it supports the suggestion that there is a specific disease of heart muscle in acromegaly.

  2. Heart cell contractions measured using a micromachined polysilicon force transducer

    NASA Astrophysics Data System (ADS)

    Lin, Gisela; Pister, Kristofer S. J.; Roos, Kenneth P.

    1995-09-01

    A microelectromechanical systems (MEMS) force transducer, with a volume less than one cubic millimeter, is being developed to measure forces generated by living, isolated cardiac muscle cells in order to resolve the complex mechanisms of muscle contraction. The force transducer consists of two movable clamps facing each other. Each clamp contains two vertical, parallel hinged polysilicon plates attached to a moveable shuttle, and the entire structure is suspended 2 micrometers above the substrate via support beams attached to the substrate at one end. Each end of a living rat heart cell is glued between a pair of vertical plates. Calcium is then introduced into the cell's nutrient bath and stimulates the cell to contract. Upon contraction the support beams bend, and the amount of deflection is translated to force via the known spring constant in the beams. Typcially the 70 micrometers long central portion of a 120 micrometers long cell will contract approximately 6-7 micrometers in full activating solution, resulting in forces up to 16 (mu) N. The average value obtained for Fmax per cross-sectional area was 21.8mN/mm2 which is comparable to the value found in other laboratories using standard transducer technology.

  3. Heart Failure Impairs Muscle Blood Flow and Endurance Exercise Tolerance in COPD.

    PubMed

    Oliveira, Mayron F; Arbex, Flavio F; Alencar, Maria Clara; Souza, Aline; Sperandio, Priscila A; Medeiros, Wladimir M; Mazzuco, Adriana; Borghi-Silva, Audrey; Medina, Luiz A; Santos, Rita; Hirai, Daniel M; Mancuso, Frederico; Almeida, Dirceu; O'Donnell, Denis E; Neder, J Alberto

    2016-08-01

    Heart failure, a prevalent and disabling co-morbidity of COPD, may impair cardiac output and muscle blood flow thereby contributing to exercise intolerance. To investigate the role of impaired central and peripheral hemodynamics in limiting exercise tolerance in COPD-heart failure overlap, cycle ergometer exercise tests at 20% and 80% peak work rate were performed by overlap (FEV1 = 56.9 ± 15.9% predicted, ejection fraction = 32.5 ± 6.9%; N = 16), FEV1-matched COPD (N = 16), ejection fraction-matched heart failure patients (N = 15) and controls (N = 12). Differences (Δ) in cardiac output (impedance cardiography) and vastus lateralis blood flow (indocyanine green) and deoxygenation (near-infrared spectroscopy) between work rates were expressed relative to concurrent changes in muscle metabolic demands (ΔO2 uptake). Overlap patients had approximately 30% lower endurance exercise tolerance than COPD and heart failure (p < 0.05). ΔBlood flow was closely proportional to Δcardiac output in all groups (r = 0.89-0.98; p < 0.01). Overlap showed the largest impairments in Δcardiac output/ΔO2 uptake and Δblood flow/ΔO2 uptake (p < 0.05). Systemic arterial oxygenation, however, was preserved in overlap compared to COPD. Blunted limb perfusion was related to greater muscle deoxygenation and lactate concentration in overlap (r = 0.78 and r = 0.73, respectively; p < 0.05). ΔBlood flow/ΔO2 uptake was related to time to exercise intolerance only in overlap and heart failure (p < 0.01). In conclusion, COPD and heart failure add to decrease exercising cardiac output and skeletal muscle perfusion to a greater extent than that expected by heart failure alone. Treatment strategies that increase muscle O2 delivery and/or decrease O2 demand may be particularly helpful to improve exercise tolerance in COPD patients presenting heart failure as co-morbidity. PMID:26790095

  4. Autophagic regulation of smooth muscle cell biology

    PubMed Central

    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

  5. Skeletal muscle stem cells from animals I. Basic cell biology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  6. Telocytes and putative stem cells in ageing human heart.

    PubMed

    Popescu, Laurentiu M; Curici, Antoanela; Wang, Enshi; Zhang, Hao; Hu, Shengshou; Gherghiceanu, Mihaela

    2015-01-01

    Tradition considers that mammalian heart consists of about 70% non-myocytes (interstitial cells) and 30% cardiomyocytes (CMs). Anyway, the presence of telocytes (TCs) has been overlooked, since they were described in 2010 (visit www.telocytes.com). Also, the number of cardiac stem cells (CSCs) has not accurately estimated in humans during ageing. We used electron microscopy to identify and estimate the number of cells in human atrial myocardium (appendages). Three age-related groups were studied: newborns (17 days-1 year), children (6-17 years) and adults (34-60 years). Morphometry was performed on low-magnification electron microscope images using computer-assisted technology. We found that interstitial area gradually increases with age from 31.3 ± 4.9% in newborns to 41 ± 5.2% in adults. Also, the number of blood capillaries (per mm(2) ) increased with several hundreds in children and adults versus newborns. CMs are the most numerous cells, representing 76% in newborns, 88% in children and 86% in adults. Images of CMs mitoses were seen in the 17-day newborns. Interestingly, no lipofuscin granules were found in CMs of human newborns and children. The percentage of cells that occupy interstitium were (depending on age): endothelial cells 52-62%; vascular smooth muscle cells and pericytes 22-28%, Schwann cells with nerve endings 6-7%, fibroblasts 3-10%, macrophages 1-8%, TCs about 1% and stem cells less than 1%. We cannot confirm the popular belief that cardiac fibroblasts are the most prevalent cell type in the heart and account for about 20% of myocardial volume. Numerically, TCs represent a small fraction of human cardiac interstitial cells, but because of their extensive telopodes, they achieve a 3D network that, for instance, supports CSCs. The myocardial (very) low capability to regenerate may be explained by the number of CSCs, which decreases fivefold by age (from 0.5% to 0.1% in newborns versus adults).

  7. Calcium versus strontium handling by the heart muscle.

    PubMed

    Hendrych, Michal; Olejnickova, Veronika; Novakova, Marie

    2016-01-01

    Calcium plays a crucial role in numerous processes in living systems, from both intracellular and intercellular signalling to blood clotting. Calcium can be replaced by strontium in various intracellular processes due to high level of their similarity and strontium thus may serve as a valuable tool for different experimental studies. On the other hand, strontium is also used in clinical medicine and is commonly taken to the human body with food and water. The negative cardiac side effects of strontium therapy of osteoporosis and bone metastases are well known, but still not fully explained. This fact explains enhanced interest in this element and its impact on human body. This article reviews effects of calcium and strontium on several biochemical and physiological processes, with special emphasis on cardiac muscle.

  8. Calcium versus strontium handling by the heart muscle.

    PubMed

    Hendrych, Michal; Olejnickova, Veronika; Novakova, Marie

    2016-01-01

    Calcium plays a crucial role in numerous processes in living systems, from both intracellular and intercellular signalling to blood clotting. Calcium can be replaced by strontium in various intracellular processes due to high level of their similarity and strontium thus may serve as a valuable tool for different experimental studies. On the other hand, strontium is also used in clinical medicine and is commonly taken to the human body with food and water. The negative cardiac side effects of strontium therapy of osteoporosis and bone metastases are well known, but still not fully explained. This fact explains enhanced interest in this element and its impact on human body. This article reviews effects of calcium and strontium on several biochemical and physiological processes, with special emphasis on cardiac muscle. PMID:26612918

  9. Isolation and Culture of Muscle Stem Cells.

    PubMed

    Mozzetta, Chiara

    2016-01-01

    Polycomb group (PcG) proteins are key epigenetic factors responsible for the proper spatiotemporal repression of defined transcriptional programs along the process of cell differentiation, including myogenesis. The discovery of the pivotal role played by PcG factors during myogenic differentiation relied on the possibility to culture myogenic cells in vitro. We describe here the methods currently used to isolate muscle stem cells (MuSCs) both from single myofibers and from bulk muscles by fluorescence-activated cell sorting (FACS), highlighting experimental details and critical steps. Through these techniques MuSCs can be efficiently isolated and cultured in vitro to recapitulate the different phases of myogenesis: activation, expansion, differentiation, and self-renewal. PMID:27659996

  10. Direct and indirect assessment of skeletal muscle blood flow in chronic congestive heart failure

    SciTech Connect

    LeJemtel, T.H.; Scortichini, D.; Katz, S.

    1988-09-09

    In patients with chronic congestive heart failure (CHF), skeletal muscle blood flow can be measured directly by the continuous thermodilution technique and by the xenon-133 clearance method. The continuous thermodilution technique requires retrograde catheterization of the femoral vein and, thus, cannot be repeated conveniently in patients during evaluation of pharmacologic interventions. The xenon-133 clearance, which requires only an intramuscular injection, allows repeated determination of skeletal muscle blood flow. In patients with severe CHF, a fixed capacity of the skeletal muscle vasculature to dilate appears to limit maximal exercise performance. Moreover, the changes in peak skeletal muscle blood flow noted during long-term administration of captopril, an angiotensin-converting enzyme inhibitor, appears to correlate with the changes in aerobic capacity. In patients with CHF, resting supine deep femoral vein oxygen content can be used as an indirect measurement of resting skeletal muscle blood flow. The absence of a steady state complicates the determination of peak skeletal muscle blood flow reached during graded bicycle or treadmill exercise in patients with chronic CHF. Indirect assessments of skeletal muscle blood flow and metabolism during exercise performed at submaximal work loads are currently developed in patients with chronic CHF.

  11. Accumulation of amino acids in muscle of perfused rat heart. Effect of insulin

    PubMed Central

    Scharff, R.; Wool, I. G.

    1965-01-01

    1. Rat heart perfused with Krebs–Henseleit bicarbonate buffer released material containing ninhydrin-positive nitrogen, but the amount was less than that reported to be released by diaphragm; glucose, but not insulin, decreased the release of ninhydrin-positive nitrogen and increased the concentration of the same material in the intracellular water of heart. 2. When heart was perfused with a mixture of amino acids and glucose, there was actually a net uptake, and an increase in intracellular concentration, of ninhydrin-positive nitrogen. Changes in the concentration of ninhydrin-positive nitrogen did not accurately reflect changes in concentration of amino acids. 3. The effect of insulin on the actual concentration of individual amino acids in heart muscle was examined by perfusing the heart with a mixture of amino acids and other ninhydrin-positive substances in the same concentration as they are found in plasma. 4. The effect of insulin on the concentrations of amino acids in the medium and in the intracellular water of the heart was determined after perfusion for different periods of time. No clear or meaningful effect of insulin was observed, despite the fact that insulin significantly increased the accumulation, in each of the same hearts, of radioactivity from amino[14C]isobutyric acid. PMID:16749112

  12. Resident c-kit+ cells in the heart are not cardiac stem cells

    PubMed Central

    Sultana, Nishat; Zhang, Lu; Yan, Jianyun; Chen, Jiqiu; Cai, Weibin; Razzaque, Shegufta; Jeong, Dongtak; Sheng, Wei; Bu, Lei; Xu, Mingjiang; Huang, Guo-Ying; Hajjar, Roger J.; Zhou, Bin; Moon, Anne; Cai, Chen-Leng

    2015-01-01

    Identifying a bona fide population of cardiac stem cells (CSCs) is a critical step for developing cell-based therapies for heart failure patients. Previously, cardiac c-kit+ cells were reported to be CSCs with a potential to become myocardial, endothelial and smooth muscle cells in vitro and after cardiac injury. Here we provide further insights into the nature of cardiac c-kit+ cells. By targeting the c-kit locus with multiple reporter genes in mice, we find that c-kit expression rarely co-localizes with the expression of the cardiac progenitor and myogenic marker Nkx2.5, or that of the myocardial marker, cardiac troponin T (cTnT). Instead, c-kit predominantly labels a cardiac endothelial cell population in developing and adult hearts. After acute cardiac injury, c-kit+ cells retain their endothelial identity and do not become myogenic progenitors or cardiomyocytes. Thus, our work strongly suggests that c-kit+ cells in the murine heart are endothelial cells and not CSCs. PMID:26515110

  13. Satellite Cell Heterogeneity in Skeletal Muscle Homeostasis.

    PubMed

    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. Ionic contrast terahertz time resolved imaging of frog auricular heart muscle electrical activity

    NASA Astrophysics Data System (ADS)

    Masson, Jean-Baptiste; Sauviat, Martin-Pierre; Gallot, Guilhem

    2006-10-01

    The authors demonstrate the direct, noninvasive and time resolved imaging of functional frog auricular fibers by ionic contrast terahertz (ICT) near field microscopy. This technique provides quantitative, time-dependent measurement of ionic flow during auricular muscle electrical activity, and opens the way of direct noninvasive imaging of cardiac activity under stimulation. ICT microscopy technique was associated with full three-dimensional simulation enabling to measure precisely the fiber sizes. This technique coupled to waveguide technology should provide the grounds to development of advanced in vivo ion flux measurement in mammalian hearts, allowing the prediction of heart attack from change in K+ fluxes.

  15. Myogenic capacity of muscle progenitor cells from head and limb muscles.

    PubMed

    Grefte, Sander; Kuijpers, Mette A R; Kuijpers-Jagtman, Anne M; Torensma, Ruurd; Von den Hoff, Johannes W

    2012-02-01

    The restoration of muscles in the soft palate of patients with cleft lip and/or palate is accompanied by fibrosis, which leads to speech and feeding problems. Treatment strategies that improve muscle regeneration have only been tested in limb muscles. Therefore, in the present study the myogenic potential of muscle progenitor cells (MPCs) isolated from head muscles was compared with that of limb muscles. Muscle progenitor cells were isolated from the head muscles and limb muscles of rats and cultured. The proliferation of MPCs was analysed by DNA quantification. The differentiation capacity was analysed by quantifying the numbers of fused cells, and by measuring the mRNA levels of differentiation markers. Muscle progenitor cells were stained to quantify the expression of paired box protein Pax 7 (Pax-7), myoblast determination protein 1 (MyoD), and myogenin. Proliferation was similar in the head MPCs and the limb MPCs. Differentiating head and limb MPCs showed a comparable number of fused cells and mRNA expression levels of myosin-1 (Myh1), myosin-3 (Myh3), and myosin-4 (Myh4). During proliferation and differentiation, the number of Pax-7(+), MyoD(+), and myogenin(+) cells in head and limb MPCs was equal. It was concluded that head and limb MPCs show similar myogenic capacities in vitro. Therefore, in vivo myogenic differences between those muscles might rely on the local microenvironment. Thus, regenerative strategies for limb muscles might also be used for head muscles.

  16. Bone Marrow Mesenchymal Cells Improve Muscle Function in a Skeletal Muscle Re-Injury Model

    PubMed Central

    Ribeiro, Karla C.; Porto, Anderson; Peçanha, Ramon; Fortes, Fabio S. A.; Zapata-Sudo, Gisele; Campos-de-Carvalho, Antonio C.; Goldenberg, Regina C. S.; Werneck-de-Castro, João Pedro

    2015-01-01

    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. PMID:26039243

  17. Virus-like particles associated with heart and skeletal muscle inflammation (HSMI).

    PubMed

    Watanabe, K; Karlsen, M; Devold, M; Isdal, E; Litlabø, A; Nylund, A

    2006-06-23

    The first cases of heart and skeletal muscle inflammation (HSMI), in Atlantic salmon Salmo salar were registered in 1999 in the Hitra/Frøya area of Norway. The disease has since spread south to Rogaland, i.e. the southernmost county with salmon farming in Norway. The disease outbreaks usually start 5 to 9 mo after release into seawater but may occur as early as 2 wk after sea release. The present study focuses on possible pathogens associated with HSMI. It was not possible to find any parasites or bacteria that could explain HSMI, and none of the well-known viruses (infectious salmon anaemia virus, Norwegian salmonid alphavirus, infectious pancreatic necrosis virus, Atlantic salmonid paramyxovirus) were consistently present. Use of transmission electron microscopy showed the presence of epitheliocystis agent in 3 of 4 farms included in this study, and several virus-like particles. Type I and Type II virus particles, previously described for salmon suffering from haemorrhagic smolt syndrome (HSS), and erythrocytic inclusion body syndrome (EIBS) virus were consistently present in salmon suffering from HSMI in all 4 farms included in this study. The 2 HSS viruses (Type I and Type II) were also cultured in Atlantic salmon kidney (ASK) cells from salmon suffering from HSMI. However, a causal relationship between the observed virus particles and HSMI remains to be demonstrated. PMID:16903229

  18. Induction of PDK4 in the heart muscle of JVS mice, an animal model of systemic carnitine deficiency, does not appear to reduce glucose utilization by the heart.

    PubMed

    Ushikai, Miharu; Horiuchi, Masahisa; Kobayashi, Keiko; Matuda, Sadayuki; Inui, Akio; Takeuchi, Toru; Saheki, Takeyori

    2011-03-01

    Pyruvate dehydrogenase kinase 4 (PDK4) mRNA has been reported as an up-regulated gene in the heart and skeletal muscle of carnitine-deficient juvenile visceral steatosis (JVS) mice under fed conditions. PDK4 plays an important role in the inhibition of glucose oxidation via the phosphorylation of pyruvate dehydrogenase complex (PDC). This study evaluated the meaning of increased PDK4 mRNA in glucose metabolism by investigating PDK4 protein levels, PDC activity and glucose uptake by the heart and skeletal muscle of JVS mice. PDK4 protein levels in the heart and skeletal muscle of fed JVS mice were increased in accordance with mRNA levels, and protein was enriched in the mitochondria. PDK4 protein was co-fractionated with PDC in sucrose density gradient centrifugation, like PDK2 protein; however, the activities of the pyruvate dehydrogenase complex (PDC) active form in the heart and skeletal muscle of fed JVS mice were similar to those in fed control mice. Fed JVS mice showed significantly higher glucose uptake in the heart and similar uptake in the skeletal muscle compared with fed control mice. Thus, in carnitine deficiency under fed conditions, glucose was preferentially utilized in the heart as an energy source despite increased PDK4 protein levels in the mitochondria. The preferred glucose utilization may be involved in developing cardiac hypertrophy from carnitine deficiency in fatty acid oxidation abnormality. PMID:21190881

  19. Morphogenesis of T-tubules in heart cells: the role of junctophilin-2.

    PubMed

    Han, Jing; Wu, Haodi; Wang, Qiwei; Wang, Shiqiang

    2013-07-01

    The T-tubule (TT) system forms the structural basis for excitation-contraction coupling in heart and muscle cells. The morphogenesis of the TT system is a key step in the maturation of heart cells because it does not exist in neonatal cardiomyocytes. In the present study, we quantified the morphological changes in TTs during heart cell maturation and investigated the role of junctophilin-2 (JP2), a protein known to anchor the sarcoplasmic reticulum (SR) to TT, in changes to TT morphological parameters. Analysis of confocal images showed that the transverse elements of TTs increased, while longitudinal elements decreased during the maturation of TTs. Fourier transform analysis showed that the power of ∼2 μm spatial components increased with cardiomyocytes maturation. These changes were preceded by increased expression of JP2, and were reversed by JP2 knockdown. These findings indicate that JP2 is required for the morphogenesis of TTs during heart development. PMID:23749380

  20. Muscle satellite cell heterogeneity and self-renewal.

    PubMed

    Motohashi, Norio; Asakura, Atsushi

    2014-01-01

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

  1. Regenerative function of immune system: Modulation of muscle stem cells.

    PubMed

    Saini, Jasdeep; McPhee, Jamie S; Al-Dabbagh, Sarah; Stewart, Claire E; Al-Shanti, Nasser

    2016-05-01

    Ageing is characterised by progressive deterioration of physiological systems and the loss of skeletal muscle mass is one of the most recognisable, leading to muscle weakness and mobility impairments. This review highlights interactions between the immune system and skeletal muscle stem cells (widely termed satellite cells or myoblasts) to influence satellite cell behaviour during muscle regeneration after injury, and outlines deficits associated with ageing. Resident neutrophils and macrophages in skeletal muscle become activated when muscle fibres are damaged via stimuli (e.g. contusions, strains, avulsions, hyperextensions, ruptures) and release high concentrations of cytokines, chemokines and growth factors into the microenvironment. These localised responses serve to attract additional immune cells which can reach in excess of 1×10(5) immune cell/mm(3) of skeletal muscle in order to orchestrate the repair process. T-cells have a delayed response, reaching peak activation roughly 4 days after the initial damage. The cytokines and growth factors released by activated T-cells play a key role in muscle satellite cell proliferation and migration, although the precise mechanisms of these interactions remain unclear. T-cells in older people display limited ability to activate satellite cell proliferation and migration which is likely to contribute to insufficient muscle repair and, consequently, muscle wasting and weakness. If the factors released by T-cells to activate satellite cells can be identified, it may be possible to develop therapeutic agents to enhance muscle regeneration and reduce the impact of muscle wasting during ageing and disease. PMID:27039885

  2. Regenerative function of immune system: Modulation of muscle stem cells.

    PubMed

    Saini, Jasdeep; McPhee, Jamie S; Al-Dabbagh, Sarah; Stewart, Claire E; Al-Shanti, Nasser

    2016-05-01

    Ageing is characterised by progressive deterioration of physiological systems and the loss of skeletal muscle mass is one of the most recognisable, leading to muscle weakness and mobility impairments. This review highlights interactions between the immune system and skeletal muscle stem cells (widely termed satellite cells or myoblasts) to influence satellite cell behaviour during muscle regeneration after injury, and outlines deficits associated with ageing. Resident neutrophils and macrophages in skeletal muscle become activated when muscle fibres are damaged via stimuli (e.g. contusions, strains, avulsions, hyperextensions, ruptures) and release high concentrations of cytokines, chemokines and growth factors into the microenvironment. These localised responses serve to attract additional immune cells which can reach in excess of 1×10(5) immune cell/mm(3) of skeletal muscle in order to orchestrate the repair process. T-cells have a delayed response, reaching peak activation roughly 4 days after the initial damage. The cytokines and growth factors released by activated T-cells play a key role in muscle satellite cell proliferation and migration, although the precise mechanisms of these interactions remain unclear. T-cells in older people display limited ability to activate satellite cell proliferation and migration which is likely to contribute to insufficient muscle repair and, consequently, muscle wasting and weakness. If the factors released by T-cells to activate satellite cells can be identified, it may be possible to develop therapeutic agents to enhance muscle regeneration and reduce the impact of muscle wasting during ageing and disease.

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

    SciTech Connect

    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.

  4. [Evaluation of heart impact in the 100 m extreme intensity sport using near-infrared non-invasive muscle oxygen detecting device and sports heart rate detection technology].

    PubMed

    Wang, Pei-Yong; Long, Fei-Xiao; Fu, Lan-Ying; Li, Yue; Ding, Hai-Shu; Qu, An-Lian; Zhou, Xiao-Ping

    2010-02-01

    Using continuous two wavelength near-infrared technology to detect the variation in the consistency of oxygen hemoglobin in the muscle and the sports heart rate wireless real time collection technology, we devised the real time muscle tissue oxygenation and instantaneous heart rate experiment scheme and implemented it for the process of the 100 m run with two parameters given simultaneously. The experiment shows that the concentration of the oxygen hemoglobin in the muscle tissue continues decreasing after the end of the 100 m run, and the time interval between the moment when the concentration of the oxygen hemoglobin attains the minimum value and the moment when the athletes finish the 100 m run is (6.65 +/- 1.10) sec; while the heart rate continues increasing after the end of the 100 m run, and the time interval between the moment when the heart rate attains the maximum value and the moment when the athletes finish the 100 m run is (8.00 +/- 1.57) sec. The results show that the two wavelength near-infrared tissue oxygenation detection technology and the sports heart rate real time collection equipment can accurately measure the sports tissue oxygenation and the heart rate in the extreme intensity sport, and reveal the process of muscle oxygen transportation and consumption and its dynamic character with the heart rate in the extreme intensity sport.

  5. Drosophila small heat shock protein CryAB ensures structural integrity of developing muscles, and proper muscle and heart performance.

    PubMed

    Wójtowicz, Inga; Jabłońska, Jadwiga; Zmojdzian, Monika; Taghli-Lamallem, Ouarda; Renaud, Yoan; Junion, Guillaume; Daczewska, Malgorzata; Huelsmann, Sven; Jagla, Krzysztof; Jagla, Teresa

    2015-03-01

    Molecular chaperones, such as the small heat shock proteins (sHsps), maintain normal cellular function by controlling protein homeostasis in stress conditions. However, sHsps are not only activated in response to environmental insults, but also exert developmental and tissue-specific functions that are much less known. Here, we show that during normal development the Drosophila sHsp CryAB [L(2)efl] is specifically expressed in larval body wall muscles and accumulates at the level of Z-bands and around myonuclei. CryAB features a conserved actin-binding domain and, when attenuated, leads to clustering of myonuclei and an altered pattern of sarcomeric actin and the Z-band-associated actin crosslinker Cheerio (filamin). Our data suggest that CryAB and Cheerio form a complex essential for muscle integrity: CryAB colocalizes with Cheerio and, as revealed by mass spectrometry and co-immunoprecipitation experiments, binds to Cheerio, and the muscle-specific attenuation of cheerio leads to CryAB-like sarcomeric phenotypes. Furthermore, muscle-targeted expression of CryAB(R120G), which carries a mutation associated with desmin-related myopathy (DRM), results in an altered sarcomeric actin pattern, in affected myofibrillar integrity and in Z-band breaks, leading to reduced muscle performance and to marked cardiac arrhythmia. Taken together, we demonstrate that CryAB ensures myofibrillar integrity in Drosophila muscles during development and propose that it does so by interacting with the actin crosslinker Cheerio. The evidence that a DRM-causing mutation affects CryAB muscle function and leads to DRM-like phenotypes in the fly reveals a conserved stress-independent role of CryAB in maintaining muscle cell cytoarchitecture.

  6. Drosophila small heat shock protein CryAB ensures structural integrity of developing muscles, and proper muscle and heart performance.

    PubMed

    Wójtowicz, Inga; Jabłońska, Jadwiga; Zmojdzian, Monika; Taghli-Lamallem, Ouarda; Renaud, Yoan; Junion, Guillaume; Daczewska, Malgorzata; Huelsmann, Sven; Jagla, Krzysztof; Jagla, Teresa

    2015-03-01

    Molecular chaperones, such as the small heat shock proteins (sHsps), maintain normal cellular function by controlling protein homeostasis in stress conditions. However, sHsps are not only activated in response to environmental insults, but also exert developmental and tissue-specific functions that are much less known. Here, we show that during normal development the Drosophila sHsp CryAB [L(2)efl] is specifically expressed in larval body wall muscles and accumulates at the level of Z-bands and around myonuclei. CryAB features a conserved actin-binding domain and, when attenuated, leads to clustering of myonuclei and an altered pattern of sarcomeric actin and the Z-band-associated actin crosslinker Cheerio (filamin). Our data suggest that CryAB and Cheerio form a complex essential for muscle integrity: CryAB colocalizes with Cheerio and, as revealed by mass spectrometry and co-immunoprecipitation experiments, binds to Cheerio, and the muscle-specific attenuation of cheerio leads to CryAB-like sarcomeric phenotypes. Furthermore, muscle-targeted expression of CryAB(R120G), which carries a mutation associated with desmin-related myopathy (DRM), results in an altered sarcomeric actin pattern, in affected myofibrillar integrity and in Z-band breaks, leading to reduced muscle performance and to marked cardiac arrhythmia. Taken together, we demonstrate that CryAB ensures myofibrillar integrity in Drosophila muscles during development and propose that it does so by interacting with the actin crosslinker Cheerio. The evidence that a DRM-causing mutation affects CryAB muscle function and leads to DRM-like phenotypes in the fly reveals a conserved stress-independent role of CryAB in maintaining muscle cell cytoarchitecture. PMID:25715399

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

    PubMed

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

    2015-10-01

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

  8. Satellite cell proliferation in adult skeletal muscle

    NASA Technical Reports Server (NTRS)

    Booth, Frank W. (Inventor); Thomason, Donald B. (Inventor); Morrison, Paul R. (Inventor); Stancel, George M. (Inventor)

    1995-01-01

    Novel methods of retroviral-mediated gene transfer for the in vivo corporation and stable expression of eukaryotic or prokaryotic foreign genes in tissues of living animals is described. More specifically, methods of incorporating foreign genes into mitotically active cells are disclosed. The constitutive and stable expression of E. coli .beta.-galactosidase gene under the promoter control of the Moloney murine leukemia virus long terminal repeat is employed as a particularly preferred embodiment, by way of example, establishes the model upon which the incorporation of a foreign gene into a mitotically-active living eukaryotic tissue is based. Use of the described methods in therapeutic treatments for genetic diseases, such as those muscular degenerative diseases, is also presented. In muscle tissue, the described processes result in genetically-altered satellite cells which proliferate daughter myoblasts which preferentially fuse to form a single undamaged muscle fiber replacing damaged muscle tissue in a treated animal. The retroviral vector, by way of example, includes a dystrophin gene construct for use in treating muscular dystrophy. The present invention also comprises an experimental model utilizable in the study of the physiological regulation of skeletal muscle gene expression in intact animals.

  9. Expression of the primary coxsackie and adenovirus receptor is downregulated during skeletal muscle maturation and limits the efficacy of adenovirus-mediated gene delivery to muscle cells.

    PubMed

    Nalbantoglu, J; Pari, G; Karpati, G; Holland, P C

    1999-04-10

    Skeletal muscle fibers are infected efficiently by adenoviral vectors only in neonatal animals. This lack of tropism for mature skeletal muscle may be partly due to inefficient binding of adenoviral particles to the cell surface. We evaluated in developing mouse muscle the expression levels of two high-affinity receptors for adenovirus, MHC class I and the coxsackie and adenovirus receptor (CAR). The moderate levels of MHC class I transcripts that were detected in quadriceps, gastrocnemius, and heart muscle did not vary between postnatal day 3 and day 60 adult tissue. A low level of CAR expression was detected on postnatal day 3 in quadriceps and gastrocnemius muscles, but CAR expression was barely detectable in adult skeletal muscle even by reverse transcriptase-polymerase chain reaction. In contrast, CAR transcripts were moderately abundant at all stages of heart muscle development. Ectopic expression of CAR in C2C12 mouse myoblast cells increased their transducibility by adenovirus at all multiplicities of infection (MOIs) tested as measured by lacZ reporter gene activity following AVCMVlacZ infection, with an 80-fold difference between CAR-expressing cells and control C2C12 cells at an MOI of 50. Primary myoblasts ectopically expressing CAR were injected into muscles of syngeneic hosts; following incorporation of the exogenous myoblasts into host myofibers, an increased transducibility of adult muscle fibers by AVCMVlacZ was observed in the host. Expression of the lacZ reporter gene in host myofibers coincided with CAR immunoreactivity. Furthermore, sarcolemmal CAR expression was markedly increased in regenerating muscle fibers of the dystrophic mdx mouse, fibers that are susceptible to adenovirus transduction. These analyses show that CAR expression by skeletal muscle correlates with its susceptibility to adenovirus transduction, and that forced CAR expression in mature myofibers dramatically increases their susceptibility to adenovirus transduction.

  10. Assessment of skeletal muscle fatigue of road maintenance workers based on heart rate monitoring and myotonometry

    PubMed Central

    Roja, Zenija; Kalkis, Valdis; Vain, Arved; Kalkis, Henrijs; Eglite, Maija

    2006-01-01

    Objective This research work is dedicated to occupational health problems caused by ergonomic risks. The research object was road building industry, where workers have to work very intensively, have long work hours, are working in forced/constrained work postures and overstrain during the work specific parts of their bodies. The aim of this study was to evaluate the work heaviness degree and to estimate the muscle fatigue of workers after one week work cycle. The study group consisted of 10 road construction and maintenance workers and 10 pavers aged between 20 and 60 years. Methods Physical load were analyzed by measuring heart rate (HR), work postures (OWAS) and perceived exertion (RPE). Assessments of the muscles strain and functional state (tone) were carried out using myotonometric (MYO) measurements. The reliability of the statistical processing of heart rate monitoring and myotonometry data was determined using correlating analysis. Results This study showed that that road construction and repairing works should be considered as a hard work according to average metabolic energy consumption 8.1 ± 1.5 kcal/min; paving, in its turn, was a moderately hard work according to 7.2 ± 1.1 kcal/min. Several muscle tone levels were identified allowing subdivision of workers into three conditional categories basing on muscle tone and fatigue: I – absolute muscle relaxation and ability to relax; II – a state of equilibrium, when muscles are able to adapt to the work load and are partly able to relax; and III – muscle fatigue and increased tone. It was also found out that the increase of muscle tone and fatigue mainly depend on workers physical preparedness and length of service, and less – on their age. Conclusion We have concluded that a complex ergonomic analysis consisting of heart rate monitoring, assessment of compulsive working postures and myotonometry is appropriate to assess the work heaviness degree and can provide prognosis of occupational pathology

  11. [Electrostimulation of skeletal muscles in combined rehabilitation of patients with chronic pulmonary heart].

    PubMed

    Sumin, A N; Snitskaia, N A; Arkhipov, O G

    2008-01-01

    101 patients with chronic respiratory pathology and emerging pulmonary heart (middle age 59 +/- 1 years), who received a medical rehabilitation, were examined with the purpose to study safety and efficiency of skeletal muscles electrostimulation. In the beginning and in the end of therapy the patients took examinations: bicycle ergometry, test with 6-minutes walking, estimation of muscular strength and tolerance with the multifunctional trainer, spirometry and echocardiography. In the main group (n=54) patients received a course of passive training with skeletal muscles electrostimulation additionally to usual rehabilitation program. In the control group (n=47) patients received only traditional program of therapy. A course of skeletal muscles electrostimulation leaded to increase of muscular strength (by 10-24%) and tolerance (by 47-67%). In the control group muscular stage did not change. Passive training also leaded to significantly greater increase of tolerance to physical exercise at bicycle ergometry (by 55%, p = 0.000001) and at the test with 6-minutes walking (by 13.9%, p = 0.000002), then in control group. Increase of vital lungs capacity at spirometry (by 4.9%, p = 0.019) and tendency to decrease of pressure in pulmonary artery according to Doppler echocardiography (p = 0.08) were registered in the main group. In the control group significant changes of respiratory function and indices of intracardicac hemodynamics were not noticed. Therefore, skeletal muscles electrostimulation deserve to be used in rehabilitation of patients with chronic pulmonary heart.

  12. Position Paper of the European Society of Cardiology Working Group Cellular Biology of the Heart: cell-based therapies for myocardial repair and regeneration in ischemic heart disease and heart failure.

    PubMed

    Madonna, Rosalinda; Van Laake, Linda W; Davidson, Sean M; Engel, Felix B; Hausenloy, Derek J; Lecour, Sandrine; Leor, Jonathan; Perrino, Cinzia; Schulz, Rainer; Ytrehus, Kirsti; Landmesser, Ulf; Mummery, Christine L; Janssens, Stefan; Willerson, James; Eschenhagen, Thomas; Ferdinandy, Péter; Sluijter, Joost P G

    2016-06-14

    Despite improvements in modern cardiovascular therapy, the morbidity and mortality of ischaemic heart disease (IHD) and heart failure (HF) remain significant in Europe and worldwide. Patients with IHD may benefit from therapies that would accelerate natural processes of postnatal collateral vessel formation and/or muscle regeneration. Here, we discuss the use of cells in the context of heart repair, and the most relevant results and current limitations from clinical trials using cell-based therapies to treat IHD and HF. We identify and discuss promising potential new therapeutic strategies that include ex vivo cell-mediated gene therapy, the use of biomaterials and cell-free therapies aimed at increasing the success rates of therapy for IHD and HF. The overall aim of this Position Paper of the ESC Working Group Cellular Biology of the Heart is to provide recommendations on how to improve the therapeutic application of cell-based therapies for cardiac regeneration and repair.

  13. Mimicking the niche: cytokines expand muscle stem cells.

    PubMed

    Quarta, Marco; Rando, Thomas A

    2015-07-01

    Muscle stem cells (MuSCs) have long been considered to be potential therapeutic vehicles for diseases of muscle such as muscular dystrophies. A recent study published in Cell Research by Fu et al. reveals that recapitulating in vitro the in vivo microenvironment of MuSCs that occurs during muscle regeneration might be a major step towards translation.

  14. Examination of mitral regurgitation with a goat heart model for the development of intelligent artificial papillary muscle.

    PubMed

    Shiraishi, Y; Yambe, T; Yoshizawa, M; Hashimoto, H; Yamada, A; Miura, H; Hashem, M; Kitano, T; Shiga, T; Homma, D

    2012-01-01

    Annuloplasty for functional mitral or tricuspid regurgitation has been made for surgical restoration of valvular diseases. However, these major techniques may sometimes be ineffective because of chamber dilation and valve tethering. We have been developing a sophisticated intelligent artificial papillary muscle (PM) by using an anisotropic shape memory alloy fiber for an alternative surgical reconstruction of the continuity of the mitral structural apparatus and the left ventricular myocardium. This study exhibited the mitral regurgitation with regard to the reduction in the PM tension quantitatively with an originally developed ventricular simulator using isolated goat hearts for the sophisticated artificial PM. Aortic and mitral valves with left ventricular free wall portions of isolated goat hearts (n=9) were secured on the elastic plastic membrane and statically pressurized, which led to valvular leaflet-papillary muscle positional change and central mitral regurgitation. PMs were connected to the load cell, and the relationship between the tension of regurgitation and PM tension were measured. Then we connected the left ventricular specimen model to our hydraulic ventricular simulator and achieved hemodynamic simulation with the controlled tension of PMs. PMID:23367454

  15. APC is required for muscle stem cell proliferation and skeletal muscle tissue repair

    PubMed Central

    Parisi, Alice; Lacour, Floriane; Giordani, Lorenzo; Colnot, Sabine; Maire, Pascal

    2015-01-01

    The tumor suppressor adenomatous polyposis coli (APC) is a crucial regulator of many stem cell types. In constantly cycling stem cells of fast turnover tissues, APC loss results in the constitutive activation of a Wnt target gene program that massively increases proliferation and leads to malignant transformation. However, APC function in skeletal muscle, a tissue with a low turnover rate, has never been investigated. Here we show that conditional genetic disruption of APC in adult muscle stem cells results in the abrogation of adult muscle regenerative potential. We demonstrate that APC removal in adult muscle stem cells abolishes cell cycle entry and leads to cell death. By using double knockout strategies, we further prove that this phenotype is attributable to overactivation of β-catenin signaling. Our results demonstrate that in muscle stem cells, APC dampens canonical Wnt signaling to allow cell cycle progression and radically diverge from previous observations concerning stem cells in actively self-renewing tissues. PMID:26304725

  16. APC is required for muscle stem cell proliferation and skeletal muscle tissue repair.

    PubMed

    Parisi, Alice; Lacour, Floriane; Giordani, Lorenzo; Colnot, Sabine; Maire, Pascal; Le Grand, Fabien

    2015-08-31

    The tumor suppressor adenomatous polyposis coli (APC) is a crucial regulator of many stem cell types. In constantly cycling stem cells of fast turnover tissues, APC loss results in the constitutive activation of a Wnt target gene program that massively increases proliferation and leads to malignant transformation. However, APC function in skeletal muscle, a tissue with a low turnover rate, has never been investigated. Here we show that conditional genetic disruption of APC in adult muscle stem cells results in the abrogation of adult muscle regenerative potential. We demonstrate that APC removal in adult muscle stem cells abolishes cell cycle entry and leads to cell death. By using double knockout strategies, we further prove that this phenotype is attributable to overactivation of β-catenin signaling. Our results demonstrate that in muscle stem cells, APC dampens canonical Wnt signaling to allow cell cycle progression and radically diverge from previous observations concerning stem cells in actively self-renewing tissues. PMID:26304725

  17. Effects of microgravity on interstitial muscle receptors affecting heart rate and blood pressure during static exercise.

    PubMed

    Essfeld, D; Baum, K; Hoffmann, U; Stegemann, J

    1993-09-01

    Afferent nerve fibers from receptors situated in the interstitium of skeletal muscles can induce cardiovascular reflexes. It has been shown that these interstitial muscle receptors are also sensitive to the local state of hydration: increased heart rates and blood pressure values were seen during dynamic and static exercise after local dehydration on earth. Since weightlessness leads to a persisting fluid loss in the lower part of the body, we hypothesized that leg exercise in space would augment heart rate and blood pressure responses to a similar extent as during local, interstitial dehydration on earth. Initial measurements during weightlessness were obtained in one subject after 6 days of space flight. Heart rate and blood pressure responses to light static foot plantar flexion (18% of maximal voluntary contraction) were recorded in two sessions. To eliminate the influence of muscle perfusion, exercise was performed during a period of arterial occlusion obtained by means of pneumatic cuffs at mid-thigh level. Identical protocols were used in the pre- and postflight controls, which were performed both in the sitting posture and in a -90 degrees tilted sitting posture assumed 30-40 min before arterial occlusion. During weightlessness the exercise responses of heart rate and systolic and diastolic blood pressure closely followed the tracings obtained with the tilted sitting posture on ground. The response amplitudes in these states of reduced lower limb volumes (about 20/min and 20 mmHg, respectively) exceeded the responses in the supine position by a factor of at least 2.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

    NASA Astrophysics Data System (ADS)

    Baum, K.; Essfeld, D.; Stegemann, J.

    To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

  19. Modulation of muscle contraction by a cell-permeable peptide

    PubMed Central

    Tünnemann, Gisela; Karczewski, Peter; Haase, Hannelore

    2007-01-01

    In contrast to immortal cell lines, primary cells are hardly susceptible to intracellular delivery methods such as transfection. In this study, we evaluated the direct delivery of several cell-permeable peptides under noninvasive conditions into living primary adult rat cardiomyocytes. We specifically monitored the functional effects of a cell-permeable peptide containing the 15 amino acid N-terminal peptide from human ventricular light chain-1 (VLC-1) on contraction and intracellular Ca2+ signals after electrical stimulation in primary adult cardiomyocytes. The transducible VLC-1 variant was taken up by cardiomyocytes within 5 min with more than 95% efficiency and localized to sarcomeric structures. Analysis of the functional effects of the cell-permeable VLC-1 revealed an enhancement of the intrinsic contractility of cardiomyocytes without affecting the intracellular Ca2+. Therefore, peptide transduction mediated by cell-penetrating peptides represents not only a unique strategy to enhance heart muscle function with no secondary effect on intracellular Ca2+ but also an invaluable tool for the modulation and manipulation of protein interactions in general and in primary cells. PMID:17717642

  20. Cell lineages, growth and repair of the mouse heart.

    PubMed

    Lescroart, Fabienne; Meilhac, Sigolène M

    2012-01-01

    The formation of the heart involves diversification of lineages which differentiate into distinct cardiac cell types or contribute to different regions such as the four cardiac chambers. The heart is the first organ to form in the embryo. However, in parallel with the growth of the organism, before or after birth, the heart has to adapt its size to maintain pumping efficiency. The adult heart has only a mild regeneration potential; thus, strategies to repair the heart after injury are based on the mobilisation of resident cardiac stem cells or the transplantation of external sources of stem cells. We discuss current knowledge on these aspects and raise questions for future research.

  1. Effects of moderate heart failure and functional overload on rat plantaris muscle

    NASA Technical Reports Server (NTRS)

    Spangenburg, Espen E.; Lees, Simon J.; Otis, Jeff S.; Musch, Timothy I.; Talmadge, Robert J.; Williams, Jay H.

    2002-01-01

    It is thought that changes in sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) of skeletal muscle contribute to alterations in skeletal muscle function during congestive heart failure (CHF). It is well established that exercise training can improve muscle function. However, it is unclear whether similar adaptations will result from exercise training in a CHF patient. Therefore, the purpose of this study was to determine whether skeletal muscle during moderate CHF adapts to increased activity, utilizing the functional overload (FO) model. Significant increases in plantaris mass of the CHF-FO and sham-FO groups compared with the CHF and control (sham) groups were observed. Ca(2+) uptake rates were significantly elevated in the CHF group compared with all other groups. No differences were detected in Ca(2+) uptake rates between the CHF-FO, sham, and sham-FO groups. Increases in Ca(2+) uptake rates in moderate-CHF rats were not due to changes in SERCA isoform proportions; however, FO may have attenuated the CHF-induced increases through alterations in SERCA isoform expression. Therefore, changes in skeletal muscle Ca(2+) handling during moderate CHF may be due to alterations in regulatory mechanisms, which exercise may override, by possibly altering SERCA isoform expression.

  2. Exhaustive exercise--a near death experience for skeletal muscle cells?

    PubMed

    Behringer, Michael; Montag, Johannes; Franz, Alexander; McCourt, Molly L; Mester, Joachim; Nosaka, Kazunori Ken

    2014-12-01

    In sports medicine, muscle enzymes in the blood are frequently used as an indicator of muscle damage. It is commonly assumed that mechanical stress disrupts plasma membrane to an extent that allows large molecules, such as enzymes, to leak into the extracellular space. However, this does not appear to fully explain changes in muscle enzyme activity in the blood after exercise. Apart from this mechanically induced membrane damage, we hypothesize that, under critical metabolic conditions, ATP consuming enzymes like creatine kinase (CK) are "volitionally" expulsed by muscle cells in order to prevent cell death. This would put themselves into a situation comparable to that of CK deficient muscle fibers, which have been shown in animal experiments to be virtually infatigable at the expense of muscle strength. Additionally we expand on this hypothesis with the idea that membrane blebbing is a way for the muscle fibers to store CK in fringe areas of the muscle fiber or to expulse CK from the cytosol by detaching the blebs from the plasma membrane. The blebbing has been shown to occur in heart muscle cells under ischaemic conditions and has been speculated to be an alternative pathway for the expulsion of troponin. The blebbing has also been seen skeletal muscle cells when intracellular calcium concentration increases. Cytoskeletal damage, induced by reactive oxygen species (ROS) or by calcium activated proteases in concert with increasing intracellular pressure, seems to provoke this type of membrane reaction. If these hypotheses are confirmed by future investigations, our current understanding of CK as a blood muscle damage marker will be fundamentally affected.

  3. Identification of Targets of CUG-BP, Elav-Like Family Member 1 (CELF1) Regulation in Embryonic Heart Muscle.

    PubMed

    Blech-Hermoni, Yotam; Dasgupta, Twishasri; Coram, Ryan J; Ladd, Andrea N

    2016-01-01

    CUG-BP, Elav-like family member 1 (CELF1) is a highly conserved RNA binding protein that regulates pre-mRNA alternative splicing, polyadenylation, mRNA stability, and translation. In the heart, CELF1 is expressed in the myocardium, where its levels are tightly regulated during development. CELF1 levels peak in the heart during embryogenesis, and aberrant up-regulation of CELF1 in the adult heart has been implicated in cardiac pathogenesis in myotonic dystrophy type 1, as well as in diabetic cardiomyopathy. Either inhibition of CELF activity or over-expression of CELF1 in heart muscle causes cardiomyopathy in transgenic mice. Nonetheless, many of the cardiac targets of CELF1 regulation remain unknown. In this study, to identify cardiac targets of CELF1 we performed cross-linking immunoprecipitation (CLIP) for CELF1 from embryonic day 8 chicken hearts. We identified a previously unannotated exon in MYH7B as a novel target of CELF1-mediated regulation. We demonstrated that knockdown of CELF1 in primary chicken embryonic cardiomyocytes leads to increased inclusion of this exon and decreased MYH7B levels. We also investigated global changes in the transcriptome of primary embryonic cardiomyocytes following CELF1 knockdown in a published RNA-seq dataset. Pathway and network analyses identified strong associations between CELF1 and regulation of cell cycle and translation. Important regulatory proteins, including both RNA binding proteins and a cardiac transcription factor, were affected by loss of CELF1. Together, these data suggest that CELF1 is a key regulator of cardiomyocyte gene expression.

  4. Identification of Targets of CUG-BP, Elav-Like Family Member 1 (CELF1) Regulation in Embryonic Heart Muscle.

    PubMed

    Blech-Hermoni, Yotam; Dasgupta, Twishasri; Coram, Ryan J; Ladd, Andrea N

    2016-01-01

    CUG-BP, Elav-like family member 1 (CELF1) is a highly conserved RNA binding protein that regulates pre-mRNA alternative splicing, polyadenylation, mRNA stability, and translation. In the heart, CELF1 is expressed in the myocardium, where its levels are tightly regulated during development. CELF1 levels peak in the heart during embryogenesis, and aberrant up-regulation of CELF1 in the adult heart has been implicated in cardiac pathogenesis in myotonic dystrophy type 1, as well as in diabetic cardiomyopathy. Either inhibition of CELF activity or over-expression of CELF1 in heart muscle causes cardiomyopathy in transgenic mice. Nonetheless, many of the cardiac targets of CELF1 regulation remain unknown. In this study, to identify cardiac targets of CELF1 we performed cross-linking immunoprecipitation (CLIP) for CELF1 from embryonic day 8 chicken hearts. We identified a previously unannotated exon in MYH7B as a novel target of CELF1-mediated regulation. We demonstrated that knockdown of CELF1 in primary chicken embryonic cardiomyocytes leads to increased inclusion of this exon and decreased MYH7B levels. We also investigated global changes in the transcriptome of primary embryonic cardiomyocytes following CELF1 knockdown in a published RNA-seq dataset. Pathway and network analyses identified strong associations between CELF1 and regulation of cell cycle and translation. Important regulatory proteins, including both RNA binding proteins and a cardiac transcription factor, were affected by loss of CELF1. Together, these data suggest that CELF1 is a key regulator of cardiomyocyte gene expression. PMID:26866591

  5. Heart regeneration.

    PubMed

    Breckwoldt, Kaja; Weinberger, Florian; Eschenhagen, Thomas

    2016-07-01

    Regenerating an injured heart holds great promise for millions of patients suffering from heart diseases. Since the human heart has very limited regenerative capacity, this is a challenging task. Numerous strategies aiming to improve heart function have been developed. In this review we focus on approaches intending to replace damaged heart muscle by new cardiomyocytes. Different strategies for the production of cardiomyocytes from human embryonic stem cells or human induced pluripotent stem cells, by direct reprogramming and induction of cardiomyocyte proliferation are discussed regarding their therapeutic potential and respective advantages and disadvantages. Furthermore, different methods for the transplantation of pluripotent stem cell-derived cardiomyocytes are described and their clinical perspectives are discussed. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  6. Immortalization of primary human smooth muscle cells.

    PubMed Central

    Perez-Reyes, N; Halbert, C L; Smith, P P; Benditt, E P; McDougall, J K

    1992-01-01

    Primary human aortic and myometrial smooth muscle cells (SMCs) were immortalized using an amphotropic recombinant retroviral construct containing the E6 and E7 open reading frames (ORFs) of human papillomavirus type 16. The SMCs expressing the E6/E7 ORFs have considerably elevated growth rates when compared with nonimmortalized control cells and show no signs of senescence with long-term passage. The first SMC line derived in this study has been maintained in continuous tissue culture for greater than 1 year (greater than 180 population doublings). The immortalized SMCs have decreased cell size and decreased content of muscle-specific alpha-actin filaments as determined by indirect immunofluorescence. Southern blot analysis has demonstrated the stable integration of the E6/E7 ORFs in the retrovirally infected cells, and radioimmunoprecipitation has confirmed the continued expression of the E6 and E7 genes. Cytogenetic studies of the SMC lines have revealed essentially diploid populations except for the myometrial clonal line, which became aneuploid at late passage (greater than 125 doublings). These cell lines were not tumorigenic in nude mice. Images PMID:1311088

  7. Sympathetic hyperactivity differentially affects skeletal muscle mass in developing heart failure: role of exercise training.

    PubMed

    Bacurau, Aline V N; Jardim, Maíra A; Ferreira, Julio C B; Bechara, Luiz R G; Bueno, Carlos R; Alba-Loureiro, Tatiana C; Negrao, Carlos E; Casarini, Dulce E; Curi, Rui; Ramires, Paulo R; Moriscot, Anselmo S; Brum, Patricia C

    2009-05-01

    Sympathetic hyperactivity (SH) is a hallmark of heart failure (HF), and several lines of evidence suggest that SH contributes to HF-induced skeletal myopathy. However, little is known about the influence of SH on skeletal muscle morphology and metabolism in a setting of developing HF, taking into consideration muscles with different fiber compositions. The contribution of SH on exercise tolerance and skeletal muscle morphology and biochemistry was investigated in 3- and 7-mo-old mice lacking both alpha(2A)- and alpha(2C)-adrenergic receptor subtypes (alpha(2A)/alpha(2C)ARKO mice) that present SH with evidence of HF by 7 mo. To verify whether exercise training (ET) would prevent skeletal muscle myopathy in advanced-stage HF, alpha(2A)/alpha(2C)ARKO mice were exercised from 5 to 7 mo of age. At 3 mo, alpha(2A)/alpha(2C)ARKO mice showed no signs of HF and preserved exercise tolerance and muscular norepinephrine with no changes in soleus morphology. In contrast, plantaris muscle of alpha(2A)/alpha(2C)ARKO mice displayed hypertrophy and fiber type shift (IIA --> IIX) paralleled by capillary rarefaction, increased hexokinase activity, and oxidative stress. At 7 mo, alpha(2A)/alpha(2C)ARKO mice displayed exercise intolerance and increased muscular norepinephrine, muscular atrophy, capillary rarefaction, and increased oxidative stress. ET reestablished alpha(2A)/alpha(2C)ARKO mouse exercise tolerance to 7-mo-old wild-type levels and prevented muscular atrophy and capillary rarefaction associated with reduced oxidative stress. Collectively, these data provide direct evidence that SH is a major factor contributing to skeletal muscle morphological changes in a setting of developing HF. ET prevented skeletal muscle myopathy in alpha(2A)/alpha(2C)ARKO mice, which highlights its importance as a therapeutic tool for HF.

  8. Lkb1 deletion promotes ectopic lipid accumulation in muscle progenitor cells and mature muscles.

    PubMed

    Shan, Tizhong; Zhang, Pengpeng; Bi, Pengpeng; Kuang, Shihuan

    2015-05-01

    Excessive intramyocellular triglycerides (muscle lipids) are associated with reduced contractile function, insulin resistance, and Type 2 diabetes, but what governs lipid accumulation in muscle is unclear. Here we report a role of Lkb1 in regulating lipid metabolism in muscle stem cells and their descendent mature muscles. We used Myod(Cre) and Lkb1(flox/flox) mice to specifically delete Lkb1 in myogenic cells including stem and differentiated cells, and examined the lipid accumulation and gene expression of myoblasts cultured from muscle stem cells (satellite cells). Genetic deletion of Lkb1 in myogenic progenitors led to elevated expression of lipogenic genes and ectopic lipid accumulation in proliferating myoblasts. Interestingly, the Lkb1-deficient myoblasts differentiated into adipocyte-like cells upon adipogenic induction. However, these adipocyte-like cells maintained myogenic gene expression with reduced ability to form myotubes efficiently. Activation of AMPK by AICAR prevented ectopic lipid formation in the Lkb1-null myoblasts. Notably, Lkb1-deficient muscles accumulated excessive lipids in vivo in response to high-fat diet feeding. These results demonstrate that Lkb1 acts through AMPK to limit lipid deposition in muscle stem cells and their derivative mature muscles, and point to the possibility of controlling muscle lipid content using AMPK activating drugs.

  9. Assessment of DNA synthesis in Islet-1{sup +} cells in the adult murine heart

    SciTech Connect

    Weinberger, Florian Mehrkens, Dennis Starbatty, Jutta Nicol, Philipp Eschenhagen, Thomas

    2015-01-02

    Highlights: • Islet-1 was expressed in the adult heart. • Islet-1-positive cells did not proliferate in the adult heart. • Sinoatrial node cells did not proliferate in the adult heart. - Abstract: Rationale: Islet-1 positive (Islet-1{sup +}) cardiac progenitor cells give rise to the right ventricle, atria and outflow tract during murine cardiac development. In the adult heart Islet-1 expression is limited to parasympathetic neurons, few cardiomyocytes, smooth muscle cells, within the proximal aorta and pulmonary artery and sinoatrial node cells. Its role in these cells is unknown. Here we tested the hypothesis that Islet-1{sup +} cells retain proliferative activity and may therefore play a role in regenerating specialized regions in the heart. Methods and results: DNA synthesis was analyzed by the incorporation of tritiated thymidine ({sup 3}H-thymidine) in Isl-1-nLacZ mice, a transgenic model with an insertion of a nuclear beta-galactosidase in the Islet-1 locus. Mice received daily injections of {sup 3}H-thymidine for 5 days. DNA synthesis was visualized throughout the heart by dipping autoradiography of cryosections. Colocalization of an nLacZ-signal and silver grains would indicate DNA synthesis in Islet-1{sup +} cells. Whereas Islet{sup −} non-myocyte nuclei were regularly marked by accumulation of silver grains, colocalization with nLacZ-signals was not detected in >25,000 cells analyzed. Conclusions: Islet-1{sup +} cells are quiescent in the adult heart, suggesting that, under normal conditions, even pacemaking cells do not proliferate at higher rates than normal cardiac myocytes.

  10. Functional heterogeneity of side population cells in skeletal muscle

    SciTech Connect

    Uezumi, Akiyoshi; Ojima, Koichi; Fukada, So-ichiro; Ikemoto, Madoka; Masuda, Satoru; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi . E-mail: takeda@ncnp.go.jp

    2006-03-17

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

  11. Single epicardial cell transcriptome sequencing identifies Caveolin 1 as an essential factor in zebrafish heart regeneration.

    PubMed

    Cao, Jingli; Navis, Adam; Cox, Ben D; Dickson, Amy L; Gemberling, Matthew; Karra, Ravi; Bagnat, Michel; Poss, Kenneth D

    2016-01-15

    In contrast to mammals, adult zebrafish have a high capacity to regenerate damaged or lost myocardium through proliferation of cardiomyocytes spared from damage. The epicardial sheet covering the heart is activated by injury and aids muscle regeneration through paracrine effects and as a multipotent cell source, and has received recent attention as a target in cardiac repair strategies. Although it is recognized that epicardium is required for muscle regeneration and itself has high regenerative potential, the extent of cellular heterogeneity within epicardial tissue is largely unexplored. Here, we performed transcriptome analysis on dozens of epicardial lineage cells purified from zebrafish harboring a transgenic reporter for the pan-epicardial gene tcf21. Hierarchical clustering analysis suggested the presence of at least three epicardial cell subsets defined by expression signatures. We validated many new pan-epicardial and epicardial markers by alternative expression assays. Additionally, we explored the function of the scaffolding protein and main component of caveolae, caveolin 1 (cav1), which was present in each epicardial subset. In BAC transgenic zebrafish, cav1 regulatory sequences drove strong expression in ostensibly all epicardial cells and in coronary vascular endothelial cells. Moreover, cav1 mutant zebrafish generated by genome editing showed grossly normal heart development and adult cardiac anatomy, but displayed profound defects in injury-induced cardiomyocyte proliferation and heart regeneration. Our study defines a new platform for the discovery of epicardial lineage markers, genetic tools, and mechanisms of heart regeneration.

  12. Alternans Arrhythmias: From Cell to Heart

    PubMed Central

    Weiss, James N.; Nivala, Michael; Garfinkel, Alan; Qu, Zhilin

    2010-01-01

    The goal of systems biology is to relate events at the molecular level to more integrated scales from organelle to cell, tissue and living organism. Here we review how normal and abnormal excitation-contraction (EC) coupling properties emerge from the protein scale, where behaviors are dominated by randomness, to the cell and tissue scales, where heart has to beat with reliable regularity for a life-time. Beginning with the fundamental unit of EC coupling, the couplon where L-type Ca channels in the sarcolemmal membrane adjoin ryanodine receptors in the sarcoplasmic reticulum membrane, we show how a network of couplons with three basic properties (random activation, refractoriness, and recruitment) produces the classical physiological properties of excitation-contraction (EC) coupling and, under pathophysiological conditions, leads to Ca alternans and Ca waves. Moving to the tissue scale, we discuss how cellular Ca alternans and Ca waves promote both reentrant and focal arrhythmias in the heart. Throughout, we emphasize the qualitatively novel properties which emerge at each new scale of integration. PMID:21212392

  13. Comparison of transcriptomic responses to pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) in heart of Atlantic salmon (Salmo salar L).

    PubMed

    Johansen, Lill-Heidi; Thim, Hanna L; Jørgensen, Sven Martin; Afanasyev, Sergey; Strandskog, Guro; Taksdal, Torunn; Fremmerlid, Kjersti; McLoughlin, Marion; Jørgensen, Jorunn B; Krasnov, Aleksei

    2015-10-01

    Pancreas disease (PD) and heart and skeletal muscle inflammation (HSMI) are viral diseases associated with SAV (salmonid alphavirus) and PRV (piscine reovirus), which induce systemic infections and pathologies in cardiac and skeletal muscle tissue of farmed Atlantic salmon (Salmo salar L), resulting in severe morbidity and mortality. While general features of the clinical symptoms and pathogenesis of salmonid viral diseases are relatively well studied, much less is known about molecular mechanisms associated with immunity and disease-specific changes. In this study, transcriptomic analyses of heart tissue from PD and HSMI challenged Atlantic salmon were done, focusing on the mature phases of both diseases at respectively 28-35 and 42-77 days post infection. A large number of immune genes was activated in both trials with prevalence of genes associated with early innate antiviral responses, their expression levels being slightly higher in PD challenged fish. Activation of the IFN axis was in parallel with inflammatory changes that involved diverse humoral and cellular factors. Adaptive immune response genes were more pronounced in fish with HSMI, as suggested by increased expression of a large number of genes associated with differentiation and maturation of B lymphocytes and cytotoxic T cells. A similar down-regulation of non-immune genes such as myofiber and mitochondrial proteins between diseases was most likely reflecting myocardial pathology. A suite of genes important for cardiac function including B-type natriuretic peptide and four neuropeptides displayed differential expression between PD and HSMI. Comparison of results revealed common and distinct features and added to the understanding of both diseases at their mature phases with typical clinical pictures. A number of genes that showed disease-specific changes can be of interest for diagnostics.

  14. Fetal muscle-derived cells can repair dystrophic muscles in mdx mice

    SciTech Connect

    Auda-Boucher, Gwenola; Rouaud, Thierry; Lafoux, Aude; Levitsky, Dmitri; Huchet-Cadiou, Corinne; Feron, Marie; Guevel, Laetitia; Talon, Sophie; Fontaine-Perus, Josiane; Gardahaut, Marie-France . E-mail: Marie-France.Gardahaut@univ-nantes.fr

    2007-03-10

    We have previously reported that CD34{sup +} cells purified from mouse fetal muscles can differentiate into skeletal muscle in vitro and in vivo when injected into muscle tissue of dystrophic mdx mice. In this study, we investigate the ability of such donor cells to restore dystrophin expression, and to improve the functional muscle capacity of the extensor digitorum longus muscle (EDL) of mdx mice. For this purpose green fluorescent-positive fetal GFP{sup +}/CD34{sup +} cells or desmin{sup +}/{sup -}LacZ/CD34{sup +} cells were transplanted into irradiated or non-irradiated mdx EDL muscle. Donor fetal muscle-derived cells predominantly fused with existing fibers. Indeed more than 50% of the myofibers of the host EDL contained donor nuclei delivering dystrophin along 80-90% of the length of their sarcolemma. The presence of significant amounts of dystrophin (about 60-70% of that found in a control wild-type mouse muscle) was confirmed by Western blot analyses. Dystrophin expression also outcompeted that of utrophin, as revealed by a spatial shift in the distribution of utrophin. At 1 month post-transplant, the recipient muscle appeared to have greater resistance to fatigue than control mdx EDL muscle during repeated maximal contractions.

  15. Telocytes and putative stem cells in ageing human heart

    PubMed Central

    Popescu, Laurentiu M; Curici, Antoanela; Wang, Enshi; Zhang, Hao; Hu, Shengshou; Gherghiceanu, Mihaela

    2015-01-01

    Tradition considers that mammalian heart consists of about 70% non-myocytes (interstitial cells) and 30% cardiomyocytes (CMs). Anyway, the presence of telocytes (TCs) has been overlooked, since they were described in 2010 (visit http://www.telocytes.com). Also, the number of cardiac stem cells (CSCs) has not accurately estimated in humans during ageing. We used electron microscopy to identify and estimate the number of cells in human atrial myocardium (appendages). Three age-related groups were studied: newborns (17 days–1 year), children (6–17 years) and adults (34–60 years). Morphometry was performed on low-magnification electron microscope images using computer-assisted technology. We found that interstitial area gradually increases with age from 31.3 ± 4.9% in newborns to 41 ± 5.2% in adults. Also, the number of blood capillaries (per mm2) increased with several hundreds in children and adults versus newborns. CMs are the most numerous cells, representing 76% in newborns, 88% in children and 86% in adults. Images of CMs mitoses were seen in the 17-day newborns. Interestingly, no lipofuscin granules were found in CMs of human newborns and children. The percentage of cells that occupy interstitium were (depending on age): endothelial cells 52–62%; vascular smooth muscle cells and pericytes 22–28%, Schwann cells with nerve endings 6–7%, fibroblasts 3–10%, macrophages 1–8%, TCs about 1% and stem cells less than 1%. We cannot confirm the popular belief that cardiac fibroblasts are the most prevalent cell type in the heart and account for about 20% of myocardial volume. Numerically, TCs represent a small fraction of human cardiac interstitial cells, but because of their extensive telopodes, they achieve a 3D network that, for instance, supports CSCs. The myocardial (very) low capability to regenerate may be explained by the number of CSCs, which decreases fivefold by age (from 0.5% to 0.1% in newborns versus adults). PMID:25545142

  16. Cdc42 and formin activity control non-muscle myosin dynamics during Drosophila heart morphogenesis

    PubMed Central

    Vogler, Georg; Liu, Jiandong; Iafe, Timothy W.; Migh, Ede; Mihály, József

    2014-01-01

    During heart formation, a network of transcription factors and signaling pathways guide cardiac cell fate and differentiation, but the genetic mechanisms orchestrating heart assembly and lumen formation remain unclear. Here, we show that the small GTPase Cdc42 is essential for Drosophila melanogaster heart morphogenesis and lumen formation. Cdc42 genetically interacts with the cardiogenic transcription factor tinman; with dDAAM which belongs to the family of actin organizing formins; and with zipper, which encodes nonmuscle myosin II. Zipper is required for heart lumen formation, and its spatiotemporal activity at the prospective luminal surface is controlled by Cdc42. Heart-specific expression of activated Cdc42, or the regulatory formins dDAAM and Diaphanous caused mislocalization of Zipper and induced ectopic heart lumina, as characterized by luminal markers such as the extracellular matrix protein Slit. Placement of Slit at the lumen surface depends on Cdc42 and formin function. Thus, Cdc42 and formins play pivotal roles in heart lumen formation through the spatiotemporal regulation of the actomyosin network. PMID:25267295

  17. Intracellular energetic units in red muscle cells.

    PubMed Central

    Saks, V A; Kaambre, T; Sikk, P; Eimre, M; Orlova, E; Paju, K; Piirsoo, A; Appaix, F; Kay, L; Regitz-Zagrosek, V; Fleck, E; Seppet, E

    2001-01-01

    The kinetics of regulation of mitochondrial respiration by endogenous and exogenous ADP in muscle cells in situ was studied in skinned cardiac and skeletal muscle fibres. Endogenous ADP production was initiated by addition of MgATP; under these conditions the respiration rate and ADP concentration in the medium were dependent on the calcium concentration, and 70-80% of maximal rate of respiration was achieved at ADP concentration below 20 microM in the medium. In contrast, when exogenous ADP was added, maximal respiration rate was observed only at millimolar concentrations. An exogenous ADP-consuming system consisting of pyruvate kinase (PK; 20-40 units/ml) and phosphoenolpyruvate (PEP; 5 mM), totally suppressed respiration activated by exogenous ADP, but the respiration maintained by endogenous ADP was not suppressed by more than 20-40%. Creatine (20 mM) further activated respiration in the presence of ATP and PK+PEP. Short treatment with trypsin (50-500 nM for 5 min) decreased the apparent K(m) for exogenous ADP from 300-350 microM to 50-60 microM, increased inhibition of respiration by PK+PEP system up to 70-80%, with no changes in MgATPase activity and maximal respiration rates. Electron-microscopic observations showed detachment of mitochondria and disordering of the regular structure of the sarcomere after trypsin treatment. Two-dimensional electrophoresis revealed a group of at least seven low-molecular-mass proteins in cardiac skinned fibres which were very sensitive to trypsin and not present in glycolytic fibres, which have low apparent K(m) for exogenous ADP. It is concluded that, in oxidative muscle cells, mitochondria are incorporated into functional complexes ('intracellular energetic units') with adjacent ADP-producing systems in myofibrils and in sarcoplasmic reticulum, probably due to specific interaction with cytoskeletal elements responsible for mitochondrial distribution in the cell. It is suggested that these complexes represent the basic

  18. ASIC3 Contributes to the Blunted Muscle Metaboreflex in Heart Failure

    PubMed Central

    Xing, Jihong; Lu, Jian; Li, Jianhua

    2014-01-01

    Introduction During exercise, the sympathetic nervous system is activated and blood pressure and heart rate increase. In heart failure (HF), the muscle metaboreceptor contribution to sympathetic outflow is attenuated and the mechanoreceptor contribution is accentuated. Previous studies suggest that lactic acid stimulates acid sensing channel subtype 3 (ASIC3), inducing a neurally mediated pressor response. Thus, we hypothesized that the pressor response to ASIC3 stimulation is smaller in HF rats due to attenuation in expression and function of ASIC3 in sensory nerves. Methods Lactic acid was injected into the arterial blood supply of the hindlimb to stimulate ASIC3 in muscle afferent nerves and evoke the muscle metaboreceptor response in control rats and HF rats. Also, western blot analysis was employed to examine expression of ASIC3 in dorsal root ganglion (DRG) and patch clamp to examine current response with ASIC3 activation. Results Lactic acid (4 µmol/kg) increased mean arterial pressure by 28±5 mmHg in controls (n=6) but only by 16±3 mmHg (P<0.05 vs. control) in HF (n=8). In addition, HF decreased the protein levels of ASIC3 in DRG (optical density: 1.03±0.02 in control vs. 0.79±0.03 in HF, P<0.05; n=6 in each group). The peak current amplitude of dorsal DRG neuron in response to ASIC3 stimulation is smaller in HF rats than that in control rats. Conclusions Compared with controls, cardiovascular responses to lactic acid administered into the hindlimb muscles are blunted in HF rats owing to attenuated ASIC3. This suggests that ASIC3 plays a role in engagement in the attenuated metaboreceptor component of the exercise pressor reflex in HF. PMID:24983337

  19. Satellite cells from dystrophic muscle retain regenerative capacity.

    PubMed

    Boldrin, Luisa; Zammit, Peter S; Morgan, Jennifer E

    2015-01-01

    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.

  20. Traction in smooth muscle cells varies with cell spreading

    NASA Technical Reports Server (NTRS)

    Tolic-Norrelykke, Iva Marija; Wang, Ning

    2005-01-01

    Changes in cell shape regulate cell growth, differentiation, and apoptosis. It has been suggested that the regulation of cell function by the cell shape is a result of the tension in the cytoskeleton and the distortion of the cell. Here we explore the association between cell-generated mechanical forces and the cell morphology. We hypothesized that the cell contractile force is associated with the degree of cell spreading, in particular with the cell length. We measured traction fields of single human airway smooth muscle cells plated on a polyacrylamide gel, in which fluorescent microbeads were embedded to serve as markers of gel deformation. The traction exerted by the cells at the cell-substrate interface was determined from the measured deformation of the gel. The traction was measured before and after treatment with the contractile agonist histamine, or the relaxing agonist isoproterenol. The relative increase in traction induced by histamine was negatively correlated with the baseline traction. On the contrary, the relative decrease in traction due to isoproterenol was independent of the baseline traction, but it was associated with cell shape: traction decreased more in elongated than in round cells. Maximum cell width, mean cell width, and projected area of the cell were the parameters most tightly coupled to both baseline and histamine-induced traction in this study. Wide and well-spread cells exerted larger traction than slim cells. These results suggest that cell contractility is controlled by cell spreading.

  1. The muscle satellite cell at 50: the formative years

    PubMed Central

    2011-01-01

    In February 1961, Alexander Mauro described a cell 'wedged' between the plasma membrane of the muscle fibre and the surrounding basement membrane. He postulated that it could be a dormant myoblast, poised to repair muscle when needed. In the same month, Bernard Katz also reported a cell in a similar location on muscle spindles, suggesting that it was associated with development and growth of intrafusal muscle fibres. Both Mauro and Katz used the term 'satellite cell' in relation to their discoveries. Today, the muscle satellite cell is widely accepted as the resident stem cell of skeletal muscle, supplying myoblasts for growth, homeostasis and repair. Since 2011 marks both the 50th anniversary of the discovery of the satellite cell, and the launch of Skeletal Muscle, it seems an opportune moment to summarise the seminal events in the history of research into muscle regeneration. We start with the 19th-century pioneers who showed that muscle had a regenerative capacity, through to the descriptions from the mid-20th century of the underlying cellular mechanisms. The journey of the satellite cell from electron microscope curio, to its gradual acceptance as a bona fide myoblast precursor, is then charted: work that provided the foundations for our understanding of the role of the satellite cell. Finally, the rapid progress in the age of molecular biology is briefly discussed, and some ongoing debates on satellite cell function highlighted. PMID:21849021

  2. Dietary nitrate supplementation: impact on skeletal muscle vascular control in exercising rats with chronic heart failure.

    PubMed

    Ferguson, Scott K; Holdsworth, Clark T; Colburn, Trenton D; Wright, Jennifer L; Craig, Jesse C; Fees, Alex; Jones, Andrew M; Allen, Jason D; Musch, Timothy I; Poole, David C

    2016-09-01

    Chronic heart failure (CHF) results in central and peripheral derangements that ultimately reduce skeletal muscle O2 delivery and impair exercise tolerance. Dietary nitrate (NO3 (-)) supplementation improves skeletal muscle vascular function and tolerance to exercise. We tested the hypothesis that NO3 (-) supplementation would elevate exercising skeletal muscle blood flow (BF) and vascular conductance (VC) in CHF rats. Myocardial infarction (MI) was induced (coronary artery ligation) in young adult male rats. After 21 days of recovery, rats randomly received 5 days of NO3 (-)-rich beetroot juice (CHF + BR, n = 10) or a placebo (CHF, n = 10). Mean arterial pressure (carotid artery catheter) and skeletal muscle BF (radiolabeled microspheres) were measured during treadmill exercise (20 m/min, 5% grade). CHF-induced dysfunction, as determined by myocardial infarction size (29 ± 3% and 33 ± 4% in CHF and CHF + BR, respectively) and left ventricular end-diastolic pressure (18 ± 2 and 18 ± 2 mmHg in CHF and CHF + BR, respectively), and exercising mean arterial pressure (131 ± 3 and 128 ± 4 mmHg in CHF and CHF + BR, respectively) were not different (P > 0.05) between groups. Total exercising hindlimb skeletal muscle BF (95 ± 5 and 116 ± 9 ml·min(-1)·100 g(-1) in CHF and CHF + BR, respectively) and VC (0.75 ± 0.05 and 0.90 ± 0.05 ml·min(-1)·100 g(-1)·mmHg(-1) in CHF and CHF + BR, respectively) were 22% and 20% greater in BR-supplemented rats, respectively (P < 0.05). During exercise, BF in 9 and VC in 10 hindlimb muscles and muscle portions were significantly greater in the CHF + BR group. These results provide strong evidence that dietary NO3 (-) supplementation improves skeletal muscle vascular function during exercise in rats with CHF and, thus, support the use of BR as a novel therapeutic modality for the treatment of CHF.

  3. Training differentially regulates elastin level and proteolysis in skeletal and heart muscles and aorta in healthy rats

    PubMed Central

    Gilbert, Anna; Wyczalkowska-Tomasik, Aleksandra; Zendzian-Piotrowska, Malgorzata; Czarkowska-Paczek, Bozena

    2016-01-01

    ABSTRACT Exercise induces changes in muscle fibers and the extracellular matrix that may depend on elastin content and the activity of proteolytic enzymes. We investigated the influence of endurance training on the gene expression and protein content and/or activity of elastin, elastase, cathepsin K, and plasmin in skeletal and heart muscles and in the aorta. Healthy rats were randomly divided into untrained (n=10) and trained (n=10; 6 weeks of endurance training with increasing load) groups. Gene expression was evaluated via qRT-PCR. Elastin content was measured via enzyme-linked immunosorbent assay and enzyme activity was measured fluorometrically. Elastin content was significantly higher in skeletal (P=0.0014) and heart muscle (P=0.000022) from trained rats versus untrained rats, but not in the aorta. Although mRNA levels in skeletal muscle did not differ between groups, the activities of elastase (P=0.0434), cathepsin K (P=0.0343) and plasmin (P=0.000046) were higher in trained rats. The levels of cathepsin K (P=0.0288) and plasminogen (P=0.0005) mRNA were higher in heart muscle from trained rats, but enzyme activity was not. Enzyme activity in the aorta did not differ between groups. Increased elastin content in muscles may result in better adaption to exercise, as may remodeling of the extracellular matrix in skeletal muscle. PMID:27069251

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

    PubMed

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

    2015-01-01

    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. PMID:26203859

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

    PubMed Central

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

    2015-01-01

    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. PMID:26203859

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

    PubMed

    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.

  7. Muscle stem cells in developmental and regenerative myogenesis

    PubMed Central

    Kang, Jong-Sun; Krauss, Robert S.

    2010-01-01

    Purpose of review Skeletal muscle development serves as a paradigm for cell lineage specification and cell differentiation. Adult skeletal muscle has high regenerative capacity, with satellite cells the primary source of this capability. This review describes recent findings on developmental and adult myogenesis with emphasis on emerging distinctions between various muscle groups and stages of myogenesis. Recent findings Muscle progenitors of the body are derived from multipotent cells of the dermomyotome and express the transcription factors Pax3 and Pax7. These cells self-renew or induce expression of muscle regulatory factors (MRFs) and differentiate. The roles of Pax3+, Pax7+ and specific MRF+ progenitor populations in trunk and limb myogenesis have been identified through cell ablation in the mouse. Various head muscles and associated satellite cells have differing developmental origins, and rely on distinct combinations of transcriptional regulators, than trunk and limb muscles. Several genetic and sorting protocols demonstrate that satellite cells are heterogeneous with some possessing stem cell properties; the relative roles of lineage and niche in these properties are being explored. While cellular mechanisms of developmental, post-natal and adult regenerative myogenesis are thought to be similar, recent studies reveal distinct genetic requirements for embryonic, fetal, post-natal and adult regenerative myogenesis. Summary Genetic determinants of formation or repair of various muscles during different stages myogenesis are unexpectedly diverse. Future studies should illuminate these differences, as well as mechanisms that underlie stem cell properties of satellite cells. PMID:20098319

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

    SciTech Connect

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

    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.

  9. Visualizing the Functional Heterogeneity of Muscle Stem Cells.

    PubMed

    Kitajima, Yasuo; Ogawa, Shizuka; Ono, Yusuke

    2016-01-01

    Skeletal muscle stem cells are satellite cells that play crucial roles in tissue repair and regeneration after muscle injury. Accumulating evidence indicates that satellite cells are genetically and functionally heterogeneous, even within the same muscle. A small population of satellite cells possesses "stemness" and exhibits the remarkable ability to regenerate through robust self-renewal when transplanted into a regenerating muscle niche. In contrast, not all satellite cells self-renew. For example, some cells are committed myogenic progenitors that immediately undergo myogenic differentiation with minimal cell division after activation. Recent studies illuminate the cellular and molecular characteristics of the functional heterogeneity among satellite cells. To evaluate heterogeneity and stem cell dynamics, here we describe methods to conduct a clonal analysis of satellite cells and to visualize a slowly dividing cell population. PMID:27052612

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

    PubMed

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

    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(-/-) 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.

  11. Mapping the Pairwise Choices Leading from Pluripotency to Human Bone, Heart, and Other Mesoderm Cell Types.

    PubMed

    Loh, Kyle M; Chen, Angela; Koh, Pang Wei; Deng, Tianda Z; Sinha, Rahul; Tsai, Jonathan M; Barkal, Amira A; Shen, Kimberle Y; Jain, Rajan; Morganti, Rachel M; Shyh-Chang, Ng; Fernhoff, Nathaniel B; George, Benson M; Wernig, Gerlinde; Salomon, Rachel E A; Chen, Zhenghao; Vogel, Hannes; Epstein, Jonathan A; Kundaje, Anshul; Talbot, William S; Beachy, Philip A; Ang, Lay Teng; Weissman, Irving L

    2016-07-14

    Stem-cell differentiation to desired lineages requires navigating alternating developmental paths that often lead to unwanted cell types. Hence, comprehensive developmental roadmaps are crucial to channel stem-cell differentiation toward desired fates. To this end, here, we map bifurcating lineage choices leading from pluripotency to 12 human mesodermal lineages, including bone, muscle, and heart. We defined the extrinsic signals controlling each binary lineage decision, enabling us to logically block differentiation toward unwanted fates and rapidly steer pluripotent stem cells toward 80%-99% pure human mesodermal lineages at most branchpoints. This strategy enabled the generation of human bone and heart progenitors that could engraft in respective in vivo models. Mapping stepwise chromatin and single-cell gene expression changes in mesoderm development uncovered somite segmentation, a previously unobservable human embryonic event transiently marked by HOPX expression. Collectively, this roadmap enables navigation of mesodermal development to produce transplantable human tissue progenitors and uncover developmental processes. VIDEO ABSTRACT. PMID:27419872

  12. Notch signal reception is required in vascular smooth muscle cells for ductus arteriosus closure.

    PubMed

    Krebs, Luke T; Norton, Christine R; Gridley, Thomas

    2016-02-01

    The ductus arteriosus is an arterial vessel that shunts blood flow away from the lungs during fetal life, but normally occludes after birth to establish the adult circulation pattern. Failure of the ductus arteriosus to close after birth is termed patent ductus arteriosus, and is one of the most common congenital heart defects. Our previous work demonstrated that vascular smooth muscle cell expression of the Jag1 gene, which encodes a ligand for Notch family receptors, is essential for postnatal closure of the ductus arteriosus in mice. However, it was not known what cell population was responsible for receiving the Jag1-mediated signal. Here we show, using smooth muscle cell-specific deletion of the Rbpj gene, which encodes a transcription factor that mediates all canonical Notch signaling, that Notch signal reception in the vascular smooth muscle cell compartment is required for ductus arteriosus closure. These data indicate that homotypic vascular smooth muscle cell interactions are required for proper contractile smooth muscle cell differentiation and postnatal closure of the ductus arteriosus in mice.

  13. Vascular Smooth Muscle Cells in Atherosclerosis.

    PubMed

    Bennett, Martin R; Sinha, Sanjay; Owens, Gary K

    2016-02-19

    The historical view of vascular smooth muscle cells (VSMCs) in atherosclerosis is that aberrant proliferation of VSMCs promotes plaque formation, but that VSMCs in advanced plaques are entirely beneficial, for example preventing rupture of the fibrous cap. However, this view has been based on ideas that there is a homogenous population of VSMCs within the plaque, that can be identified separate from other plaque cells (particularly macrophages) using standard VSMC and macrophage immunohistochemical markers. More recent genetic lineage tracing studies have shown that VSMC phenotypic switching results in less-differentiated forms that lack VSMC markers including macrophage-like cells, and this switching directly promotes atherosclerosis. In addition, VSMC proliferation may be beneficial throughout atherogenesis, and not just in advanced lesions, whereas VSMC apoptosis, cell senescence, and VSMC-derived macrophage-like cells may promote inflammation. We review the effect of embryological origin on VSMC behavior in atherosclerosis, the role, regulation and consequences of phenotypic switching, the evidence for different origins of VSMCs, and the role of individual processes that VSMCs undergo in atherosclerosis in regard to plaque formation and the structure of advanced lesions. We think there is now compelling evidence that a full understanding of VSMC behavior in atherosclerosis is critical to identify therapeutic targets to both prevent and treat atherosclerosis.

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

    PubMed Central

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

    2015-01-01

    In response injury, intrinsic repair mechanisms are activated in skeletal muscle to replace the damaged muscle fibers with new muscle fibers. The regeneration process starts with the proliferation of satellite cells to give rise to myoblasts, which subsequently differentiate terminally into myofibers. Here, we investigated the promotion effect of pigment epithelial-derived factor (PEDF) on muscle regeneration. We report that PEDF and a synthetic PEDF-derived short peptide (PSP; residues Ser93-Leu112) induce satellite cell proliferation in vitro and promote muscle regeneration in vivo. Extensively, soleus muscle necrosis was induced in rats by bupivacaine, and an injectable alginate gel was used to release the PSP in the injured muscle. PSP delivery was found to stimulate satellite cell proliferation in damaged muscle and enhance the growth of regenerating myofibers, with complete regeneration of normal muscle mass by 2 wk. In cell culture, PEDF/PSP stimulated C2C12 myoblast proliferation, together with a rise in cyclin D1 expression. PEDF induced the phosphorylation of ERK1/2, Akt, and STAT3 in C2C12 myoblasts. Blocking the activity of ERK, Akt, or STAT3 with pharmacological inhibitors attenuated the effects of PEDF/PSP on the induction of C2C12 cell proliferation and cyclin D1 expression. Moreover, 5-bromo-2′-deoxyuridine pulse-labeling demonstrated that PEDF/PSP stimulated primary rat satellite cell proliferation in myofibers in vitro. In summary, we report for the first time that PSP is capable of promoting the regeneration of skeletal muscle. The signaling mechanism involves the ERK, AKT, and STAT3 pathways. These results show the potential utility of this PEDF peptide for muscle regeneration. PMID:26040897

  15. Advancements in stem cells treatment of skeletal muscle wasting

    PubMed Central

    Meregalli, Mirella; Farini, Andrea; Sitzia, Clementina; Torrente, Yvan

    2014-01-01

    Muscular dystrophies (MDs) are a heterogeneous group of inherited disorders, in which progressive muscle wasting and weakness is often associated with exhaustion of muscle regeneration potential. Although physiological properties of skeletal muscle tissue are now well known, no treatments are effective for these diseases. Muscle regeneration was attempted by means transplantation of myogenic cells (from myoblast to embryonic stem cells) and also by interfering with the malignant processes that originate in pathological tissues, such as uncontrolled fibrosis and inflammation. Taking into account the advances in the isolation of new subpopulation of stem cells and in the creation of artificial stem cell niches, we discuss how these emerging technologies offer great promises for therapeutic approaches to muscle diseases and muscle wasting associated with aging. PMID:24575052

  16. Action of Obestatin in Skeletal Muscle Repair: Stem Cell Expansion, Muscle Growth, and Microenvironment Remodeling

    PubMed Central

    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

    2015-01-01

    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. PMID:25762009

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

    PubMed

    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.

  18. Mechanotransduction in colonic smooth muscle cells.

    PubMed

    Young, S H; Ennes, H S; Mayer, E A

    1997-11-15

    We evaluated mechanisms which mediate alterations in intracellular biochemical events in response to transient mechanical stimulation of colonic smooth muscle cells. Cultured myocytes from the circular muscle layer of the rabbit distal colon responded to brief focal mechanical deformation of the plasma membrane with a transient increase in intracellular calcium concentration ([Ca2+]i) with peak of 422.7 +/- 43.8 nm above an average resting [Ca2+]i of 104.8 +/- 10.9 nM (n = 57) followed by both rapid and prolonged recovery phases. The peak [Ca2+]i increase was reduced by 50% in the absence of extracellular Ca2+, while the prolonged [Ca2+]i recovery was either abolished or reduced to less than or = 15% of control values. In contrast, no significant effect of gadolinium chloride (100 microM) or lanthanum chloride (25 microM) on either peak transient or prolonged [Ca2+]i recovery was observed. Pretreatment of cells with thapsigargin (1 microM) resulted in a 25% reduction of the mechanically induced peak [Ca2+]i response, while the phospholipase C inhibitor U-73122 had no effect on the [Ca2+]i transient peak. [Ca2+]i transients were abolished when cells previously treated with thapsigargin were mechanically stimulated in Ca2+-free solution, or when Ca2+ stores were depleted by thapsigargin in Ca2+-free solution. Pretreatment with the microfilament disrupting drug cytochalasin D (10 microM) or microinjection of myocytes with an intracellular saline resulted in complete inhibition of the transient. The effect of cytochalasin D was reversible and did not prevent the [Ca2+]i increases in response to thapsigargin. These results suggest a communication, which may be mediated by direct mechanical link via actin filaments, between the plasma membrane and an internal Ca2+ store.

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

    PubMed

    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.

  20. Muscle sympathetic activity in resting and exercising humans with and without heart failure.

    PubMed

    Notarius, Catherine F; Millar, Philip J; Floras, John S

    2015-11-01

    The sympathetic nervous system is critical for coordinating the cardiovascular response to various types of physical exercise. In a number of disease states, including human heart failure with reduced ejection fraction (HFrEF), this regulation can be disturbed and adversely affect outcome. The purpose of this review is to describe sympathetic activity at rest and during exercise in both healthy humans and those with HFrEF and outline factors, which influence these responses. We focus predominately on studies that report direct measurements of efferent sympathetic nerve traffic to skeletal muscle (muscle sympathetic nerve activity; MSNA) using intraneural microneurographic recordings. Differences in MSNA discharge between subjects with and without HFrEF both at rest and during exercise and the influence of exercise training on the sympathetic response to exercise will be discussed. In contrast to healthy controls, MSNA increases during mild to moderate dynamic exercise in the presence of HFrEF. This increase may contribute to the exercise intolerance characteristic of HFrEF by limiting muscle blood flow and may be attenuated by exercise training. Future investigations are needed to clarify the neural afferent mechanisms that contribute to efferent sympathetic activation at rest and during exercise in HFrEF.

  1. Increase of Labeled Calcium Uptake in Heart Muscle during Potassium Lack Contracture

    PubMed Central

    Thomas, Lyell J.

    1960-01-01

    Analyses of ashed muscle tissue show that the uptake of Ca45 by isolated frog heart ventricles from normal Ringer's solution containing 1 mM Ca reaches a maximum value in about 30 minutes of perfusion which is not exceeded after 3 hours of perfusion. The average amount of this labeled Ca taken up from normal Ringer's is 0.7 mM/kg. wet weight of muscle. In contrast to this, the amount of labeled Ca taken up by ventricles perfused with K-free Ringer's increases at a linear rate over a 60 minute period to twice the normal value coinciding with the gradual development of contracture and coinciding with a cellular K loss and Na gain of about 30 mM/kg. How much of the extra labeled Ca taken up from K-free Ringer's represents a net gain in cellular Ca content is not known. However, evidence has been obtained that some of this labeled Ca enters an intracellular compartment. EDTA in K-free Ringer's solution causes relaxation of ventricles in contracture and also renders the muscle fibers indiscriminately permeable. This indicates that a combination of Ca with sensitive intracellular sites is probably the cause of the K lack contracture. PMID:13838003

  2. Muscle sympathetic activity in resting and exercising humans with and without heart failure.

    PubMed

    Notarius, Catherine F; Millar, Philip J; Floras, John S

    2015-11-01

    The sympathetic nervous system is critical for coordinating the cardiovascular response to various types of physical exercise. In a number of disease states, including human heart failure with reduced ejection fraction (HFrEF), this regulation can be disturbed and adversely affect outcome. The purpose of this review is to describe sympathetic activity at rest and during exercise in both healthy humans and those with HFrEF and outline factors, which influence these responses. We focus predominately on studies that report direct measurements of efferent sympathetic nerve traffic to skeletal muscle (muscle sympathetic nerve activity; MSNA) using intraneural microneurographic recordings. Differences in MSNA discharge between subjects with and without HFrEF both at rest and during exercise and the influence of exercise training on the sympathetic response to exercise will be discussed. In contrast to healthy controls, MSNA increases during mild to moderate dynamic exercise in the presence of HFrEF. This increase may contribute to the exercise intolerance characteristic of HFrEF by limiting muscle blood flow and may be attenuated by exercise training. Future investigations are needed to clarify the neural afferent mechanisms that contribute to efferent sympathetic activation at rest and during exercise in HFrEF. PMID:26481289

  3. Use of 5-Bromodeoxyuridine and irradiation for the estimation of the myoblast and myocyte content of primary rat heart cell cultures

    SciTech Connect

    Masse, M.J.O.; Harary, I.

    1980-11-01

    A method for killing dividing cells was adapted for the elimination of dividing heart muscle cells (myoblasts) in cultures. We have used this method to demonstrate their presence and to estimate their number as well as the number of nondividing heart muscle cells (myocytes) in the neo-natal rat heart. Cells were cultivated in BUdR (5-bromodeoxyuridine) 10/sup -4/ M for 3 days and then irradiated with long uv light. The selective elimination of dividing cells led to a loss of myosin Ca/sup 2 +/-activated ATPase in the cultures. The percent of ATPase left after irradiation was 32% of the control in cultures derived from 1-day postnatal rats and 48% in cultures from 4-day postnatal rats. This reflects an in vivo shift of myoblasts to myocytes in the muscle cell population as the rat ages.

  4. Determination of individual long-chain fatty acyl-CoA esters in heart and skeletal muscle.

    PubMed

    Molaparast-Saless, F; Shrago, E; Spennetta, T L; Donatello, S; Kneeland, L M; Nellis, S H; Liedtke, A J

    1988-05-01

    A method has been developed for determination of individual long-chain fatty acyl-CoA esters from heart and skeletal muscle using high performance liquid chromatography (HPLC). The esters were extracted from freeze-clamped tissue of pig and rat hearts and rat skeletal muscle for analysis on a radially compressed C18 5mu reverse-phase column. Nine peaks in the extract with carbon chain lengths from C12 to C20 that subsequently disappeared on alkaline hydrolysis were identified. The major acyl-CoA peaks were 14:1, 18:2, 16:0 and 18:1 and additionally in rat heart 18:0. Total long-chain acyl-CoA esters obtained by summation of the individual molecular species was 11.34 +/- 1.48 nmol/g wet wt. pig heart; 14.51 +/- 2.11 nmol/g wet wt. in rat heart, and 4.35 +/- 0.71 nmol/g wet wt. in rat skeletal muscle. These values were approximately 132% of those obtained using a separate procedure that measured total CoA by HPLC after alkaline hydrolysis of the esters. The described method demonstrates the quantitation of individual acyl-CoA species in muscle tissue. Therefore, it has a number of advantages in that it permits information to be obtained on the individual molecular species under various nutritional and metabolic conditions.

  5. Still Heart Encodes a Structural HMT, SMYD1b, with Chaperone-Like Function during Fast Muscle Sarcomere Assembly.

    PubMed

    Prill, Kendal; Windsor Reid, Pamela; Wohlgemuth, Serene L; Pilgrim, David B

    2015-01-01

    The vertebrate sarcomere is a complex and highly organized contractile structure whose assembly and function requires the coordination of hundreds of proteins. Proteins require proper folding and incorporation into the sarcomere by assembly factors, and they must also be maintained and replaced due to the constant physical stress of muscle contraction. Zebrafish mutants affecting muscle assembly and maintenance have proven to be an ideal tool for identification and analysis of factors necessary for these processes. The still heart mutant was identified due to motility defects and a nonfunctional heart. The cognate gene for the mutant was shown to be smyd1b and the still heart mutation results in an early nonsense codon. SMYD1 mutants show a lack of heart looping and chamber definition due to a lack of expression of heart morphogenesis factors gata4, gata5 and hand2. On a cellular level, fast muscle fibers in homozygous mutants do not form mature sarcomeres due to the lack of fast muscle myosin incorporation by SMYD1b when sarcomeres are first being assembled (19hpf), supporting SMYD1b as an assembly protein during sarcomere formation. PMID:26544721

  6. A fetal human heart cardiac-inducing RNA (CIR) promotes the differentiation of stem cells into cardiomyocytes.

    PubMed

    Kochegarov, Andrei; Moses-Arms, Ashley; Lemanski, Larry F

    2015-08-01

    A specific human fetal heart RNA has been discovered, which has the ability to induce myocardial cell formation from mouse embryonic and human-induced pluripotent stem cells in culture. In this study, commercially obtained RNA from human fetal heart was cloned, sequenced, and synthesized using standard laboratory approaches. Molecular analyses of the specific fetal cardiac-inducing RNA (CIR), revealed that it is a fragment of N-sulfoglucosaminesulfohydrolase and the caspase recruitment domain family member 14 precursor. Stem cells transfected with CIRs often form into spindle-shaped cells characteristic of cardiomyocytes,and express the cardiac-specific contractile protein marker, troponin-T, in addition to tropomyosin and α-actinin as detected by immunohistochemical staining. Expression of these contractile proteins showed organization into sarcomeric myofibrils characteristic of striated cardiac muscle cells. Computer analyses of the RNA secondary structures of the active CIR show significant similarities to a RNA from salamander or myofibril-inducing RNA (MIR), which also promotes non-muscle cells to differentiate into cardiac muscle. Thus, these two RNAs, salamander MIR and the newly discovered human-cloned CIR reported here, appear to have evolutionarily conserved secondary structures suggesting that both play major roles in vertebrate heart development and, particularly, in the differentiation of cardiomyocytes from non-muscle cells during development.

  7. A fetal human heart cardiac-inducing RNA (CIR) promotes the differentiation of stem cells into cardiomyocytes.

    PubMed

    Kochegarov, Andrei; Moses-Arms, Ashley; Lemanski, Larry F

    2015-08-01

    A specific human fetal heart RNA has been discovered, which has the ability to induce myocardial cell formation from mouse embryonic and human-induced pluripotent stem cells in culture. In this study, commercially obtained RNA from human fetal heart was cloned, sequenced, and synthesized using standard laboratory approaches. Molecular analyses of the specific fetal cardiac-inducing RNA (CIR), revealed that it is a fragment of N-sulfoglucosaminesulfohydrolase and the caspase recruitment domain family member 14 precursor. Stem cells transfected with CIRs often form into spindle-shaped cells characteristic of cardiomyocytes,and express the cardiac-specific contractile protein marker, troponin-T, in addition to tropomyosin and α-actinin as detected by immunohistochemical staining. Expression of these contractile proteins showed organization into sarcomeric myofibrils characteristic of striated cardiac muscle cells. Computer analyses of the RNA secondary structures of the active CIR show significant similarities to a RNA from salamander or myofibril-inducing RNA (MIR), which also promotes non-muscle cells to differentiate into cardiac muscle. Thus, these two RNAs, salamander MIR and the newly discovered human-cloned CIR reported here, appear to have evolutionarily conserved secondary structures suggesting that both play major roles in vertebrate heart development and, particularly, in the differentiation of cardiomyocytes from non-muscle cells during development. PMID:25761723

  8. Turning terminally differentiated skeletal muscle cells into regenerative progenitors.

    PubMed

    Wang, Heng; Lööf, Sara; Borg, Paula; Nader, Gustavo A; Blau, Helen M; Simon, András

    2015-01-01

    The ability to repeatedly regenerate limbs during the entire lifespan of an animal is restricted to certain salamander species among vertebrates. This ability involves dedifferentiation of post-mitotic cells into progenitors that in turn form new structures. A long-term enigma has been how injury leads to dedifferentiation. Here we show that skeletal muscle dedifferentiation during newt limb regeneration depends on a programmed cell death response by myofibres. We find that programmed cell death-induced muscle fragmentation produces a population of 'undead' intermediate cells, which have the capacity to resume proliferation and contribute to muscle regeneration. We demonstrate the derivation of proliferating progeny from differentiated, multinucleated muscle cells by first inducing and subsequently intercepting a programmed cell death response. We conclude that cell survival may be manifested by the production of a dedifferentiated cell with broader potential and that the diversion of a programmed cell death response is an instrument to achieve dedifferentiation. PMID:26243583

  9. Turning terminally differentiated skeletal muscle cells into regenerative progenitors.

    PubMed

    Wang, Heng; Lööf, Sara; Borg, Paula; Nader, Gustavo A; Blau, Helen M; Simon, András

    2015-01-01

    The ability to repeatedly regenerate limbs during the entire lifespan of an animal is restricted to certain salamander species among vertebrates. This ability involves dedifferentiation of post-mitotic cells into progenitors that in turn form new structures. A long-term enigma has been how injury leads to dedifferentiation. Here we show that skeletal muscle dedifferentiation during newt limb regeneration depends on a programmed cell death response by myofibres. We find that programmed cell death-induced muscle fragmentation produces a population of 'undead' intermediate cells, which have the capacity to resume proliferation and contribute to muscle regeneration. We demonstrate the derivation of proliferating progeny from differentiated, multinucleated muscle cells by first inducing and subsequently intercepting a programmed cell death response. We conclude that cell survival may be manifested by the production of a dedifferentiated cell with broader potential and that the diversion of a programmed cell death response is an instrument to achieve dedifferentiation.

  10. Clonogenic multipotent stem cells in human adipose tissue differentiate into functional smooth muscle cells

    PubMed Central

    Rodríguez, Larissa V.; Alfonso, Zeni; Zhang, Rong; Leung, Joanne; Wu, Benjamin; Ignarro, Louis J.

    2006-01-01

    Smooth muscle is a major component of human tissues and is essential for the normal function of a multitude of organs including the intestine, urinary tract and the vascular system. The use of stem cells for cell-based tissue engineering and regeneration strategies represents a promising alternative for smooth muscle repair. For such strategies to succeed, a reliable source of smooth muscle precursor cells must be identified. Adipose tissue provides an abundant source of multipotent cells. In this study, the capacity of processed lipoaspirate (PLA) and adipose-derived stem cells to differentiate into phenotypic and functional smooth muscle cells was evaluated. To induce differentiation, PLA cells were cultured in smooth muscle differentiation medium. Smooth muscle differentiation of PLA cells induced genetic expression of all smooth muscle markers and further confirmed by increased protein expression of smooth muscle cell-specific α actin (ASMA), calponin, caldesmon, SM22, myosin heavy chain (MHC), and smoothelin. Clonal studies of adipose derived multipotent cells demonstrated differentiation of these cells into smooth muscle cells in addition to trilineage differentiation capacity. Importantly, smooth muscle-differentiated cells, but not their precursors, exhibit the functional ability to contract and relax in direct response to pharmacologic agents. In conclusion, adipose-derived cells have the potential to differentiate into functional smooth muscle cells and, thus, adipose tissue can be a useful source of cells for treatment of injured tissues where smooth muscle plays an important role. PMID:16880387

  11. Age-associated decrease in muscle precursor cell differentiation.

    PubMed

    Lees, Simon J; Rathbone, Christopher R; Booth, Frank W

    2006-02-01

    Muscle precursor cells (MPCs) are required for the regrowth, regeneration, and/or hypertrophy of skeletal muscle, which are deficient in sarcopenia. In the present investigation, we have addressed the issue of age-associated changes in MPC differentiation. MPCs, including satellite cells, were isolated from both young and old rat skeletal muscle with a high degree of myogenic purity (>90% MyoD and desmin positive). MPCs isolated from skeletal muscle of 32-mo-old rats exhibited decreased differentiation into myotubes and demonstrated decreased myosin heavy chain (MHC) and muscle creatine kinase (CK-M) expression compared with MPCs isolated from 3-mo-old rats. p27(Kip1) is a cyclin-dependent kinase inhibitor that has been shown to enhance muscle differentiation in culture. Herein we describe our finding that p27(Kip1) protein was lower in differentiating MPCs from skeletal muscle of 32-mo-old rats than in 3-mo-old rat skeletal muscle. Although MHC and CK-M expression were approximately 50% lower in differentiating MPCs isolated from 32-mo-old rats, MyoD protein content was not different and myogenin protein concentration was twofold higher. These data suggest that there are inherent differences in cell signaling during the transition from cell cycle arrest to the formation of myotubes in MPCs isolated from sarcopenic muscle. Furthermore, there is an age-associated decrease in muscle-specific protein expression in differentiating MPCs despite normal MyoD and elevated myogenin levels. PMID:16192302

  12. Muscle cell fate choice requires the T-box transcription factor midline in Drosophila.

    PubMed

    Kumar, Ram P; Dobi, Krista C; Baylies, Mary K; Abmayr, Susan M

    2015-03-01

    Drosophila Midline (Mid) is an ortholog of vertebrate Tbx20, which plays roles in the developing heart, migrating cranial motor neurons, and endothelial cells. Mid functions in cell-fate specification and differentiation of tissues that include the ectoderm, cardioblasts, neuroblasts, and egg chambers; however, a role in the somatic musculature has not been described. We identified mid in genetic and molecular screens for factors contributing to somatic muscle morphogenesis. Mid is expressed in founder cells (FCs) for several muscle fibers, and functions cooperatively with the T-box protein H15 in lateral oblique muscle 1 and the segment border muscle. Mid is particularly important for the specification and development of the lateral transverse (LT) muscles LT3 and LT4, which arise by asymmetric division of a single muscle progenitor. Mid is expressed in this progenitor and its two sibling FCs, but is maintained only in the LT4 FC. Both muscles were frequently missing in mid mutant embryos, and LT4-associated expression of the transcription factor Krüppel (Kr) was lost. When present, LT4 adopted an LT3-like morphology. Coordinately, mid misexpression caused LT3 to adopt an LT4-like morphology and was associated with ectopic Kr expression. From these data, we concluded that mid functions first in the progenitor to direct development of LT3 and LT4, and later in the FCs to influence whichever of these differentiation profiles is selected. Mid is the first T-box factor shown to influence LT3 and LT4 muscle identity and, along with the T-box protein Optomotor-blind-related-gene 1 (Org-1), is representative of a new class of transcription factors in muscle specification.

  13. Genetic mapping of human heart-skeletal muscle adenine nucleotide translocator and its relationship to the facioscapulohumeral muscular dystrophy locus

    SciTech Connect

    Haraguchi, Y.; Chung, A.B.; Torroni, A.; Stepien, G.; Shoffner, J.M.; Costigan, D.A.; Polak, M.; Wasmuth, J.J.; Altherr, M.R.; Winokur, S.T.

    1993-05-01

    The mitochondrial heart-skeletal muscle adenine nucleotide translocator (ANT1) was regionally mapped to 4q35-qter using somatic cell hybrids containing deleted chromosome 4. The regional location was further refined through family studies using ANT1 intron and promoter nucleotide polymorphisms recognized by the restriction endonucleases MboII, NdeI, and HaeIII. Two alleles were found, each at a frequency of 0.5. The ANT1 locus was found to be closely linked to D4S139, D4S171, and the dominant skeletal muscle disease locus facioscapulohumeral muscular dystrophy (FSHD). A crossover that separated D4S171 and ANT1 from D4S139 was found. Since previous studies have established the chromosome 4 map order as centromere-D4S171-D4S139-FSHD, it was concluded that ANT1 is located on the side of D4S139, that is opposite from FSHD. This conclusion was confirmed by sequencing the exons and analyzing the transcripts of ANT1 from several FSHD patients and finding no evidence of aberration. 35 refs., 5 figs., 1 tab.

  14. Resveratrol causes cell cycle arrest, decreased collagen synthesis, and apoptosis in rat intestinal smooth muscle cells.

    PubMed

    Garcia, Patricia; Schmiedlin-Ren, Phyllissa; Mathias, Jason S; Tang, Huaijing; Christman, Gregory M; Zimmermann, Ellen M

    2012-02-01

    One of the most difficult and treatment-resistant complications of Crohn's disease is the development of fibrotic intestinal strictures due to mesenchymal cell hyperplasia and collagen deposition. Resveratrol, a phytoalexin found in berries, peanuts, grapes, and red wine, has been shown to inhibit fibrosis in vasculature, heart, lung, kidney, liver, and esophagus in animal models. Resveratrol has also been shown to inhibit oxidation, inflammation, and cell proliferation and to decrease collagen synthesis in several cell types or animal models. The aim of this study was to determine whether resveratrol has antifibrotic effects on intestinal smooth muscle cells. Responses to resveratrol by cultured smooth muscle cells isolated from colons of untreated Lewis rats were examined; this rat strain is used in a model of Crohn's disease with prominent intestinal fibrosis. A relative decrease in cell numbers following treatment with 50 and 100 μM resveratrol was evident at 24 h (P ≤ 0.005). This effect was largely due to cell cycle arrest, with an increase in the percent of cells in S phase from 8 to 25-35% (P < 0.05). Cell viability was unchanged until 2-3 days of treatment when there was a 1.2- to 5.0-fold increase in the percent of apoptotic cells, depending on the assay (P < 0.05). Expression of collagen type I protein was decreased following treatment with resveratrol for 24 h (to 44 and 25% of control levels with 50 and 100 μM resveratrol, respectively; P < 0.05). Expression of procollagen types I and III mRNA was also decreased with resveratrol treatment. Resveratrol (50 μM) diminished the proliferative response to TGF-β₁ (P = 0.02) as well as IGF-I-stimulated collagen production (P = 0.02). Thus resveratrol decreases intestinal smooth muscle cell numbers through its effects on cell cycle arrest and apoptosis and also decreases collagen synthesis by the cells. These effects could be useful in preventing the smooth muscle cell hyperplasia and collagen

  15. Miniaturized iPS-Cell-Derived Cardiac Muscles for Physiologically Relevant Drug Response Analyses

    PubMed Central

    Huebsch, Nathaniel; Loskill, Peter; Deveshwar, Nikhil; Spencer, C. Ian; Judge, Luke M.; Mandegar, Mohammad A.; B. Fox, Cade; Mohamed, Tamer M.A.; Ma, Zhen; Mathur, Anurag; Sheehan, Alice M.; Truong, Annie; Saxton, Mike; Yoo, Jennie; Srivastava, Deepak; Desai, Tejal A.; So, Po-Lin; Healy, Kevin E.; Conklin, Bruce R.

    2016-01-01

    Tissue engineering approaches have the potential to increase the physiologic relevance of human iPS-derived cells, such as cardiomyocytes (iPS-CM). However, forming Engineered Heart Muscle (EHM) typically requires >1 million cells per tissue. Existing miniaturization strategies involve complex approaches not amenable to mass production, limiting the ability to use EHM for iPS-based disease modeling and drug screening. Micro-scale cardiospheres are easily produced, but do not facilitate assembly of elongated muscle or direct force measurements. Here we describe an approach that combines features of EHM and cardiospheres: Micro-Heart Muscle (μHM) arrays, in which elongated muscle fibers are formed in an easily fabricated template, with as few as 2,000 iPS-CM per individual tissue. Within μHM, iPS-CM exhibit uniaxial contractility and alignment, robust sarcomere assembly, and reduced variability and hypersensitivity in drug responsiveness, compared to monolayers with the same cellular composition. μHM mounted onto standard force measurement apparatus exhibited a robust Frank-Starling response to external stretch, and a dose-dependent inotropic response to the β-adrenergic agonist isoproterenol. Based on the ease of fabrication, the potential for mass production and the small number of cells required to form μHM, this system provides a potentially powerful tool to study cardiomyocyte maturation, disease and cardiotoxicology in vitro. PMID:27095412

  16. Transplantated Mesenchymal Stem Cells Derived from Embryonic Stem Cells Promote Muscle Regeneration and Accelerate Functional Recovery of Injured Skeletal Muscle

    PubMed Central

    Ninagawa, Nana Takenaka; Isobe, Eri; Hirayama, Yuri; Murakami, Rumi; Komatsu, Kazumi; Nagai, Masataka; Kobayashi, Mami; Kawabata, Yuka

    2013-01-01

    Abstract We previously established that mesenchymal stem cells originating from mouse embryonic stem (ES) cells (E-MSCs) showed markedly higher potential for differentiation into skeletal muscles in vitro than common mesenchymal stem cells (MSCs). Further, the E-MSCs exhibited a low risk for teratoma formation. Here we evaluate the potential of E-MSCs for differentiation into skeletal muscles in vivo and reveal the regeneration and functional recovery of injured muscle by transplantation. E-MSCs were transplanted into the tibialis anterior (TA) muscle 24 h following direct clamping. After transplantation, the myogenic differentiation of E-MSCs, TA muscle regeneration, and re-innervation were morphologically analyzed. In addition, footprints and gaits of each leg under spontaneous walking were measured by CatWalk XT, and motor functions of injured TA muscles were precisely analyzed. Results indicate that >60% of transplanted E-MSCs differentiated into skeletal muscles. The cross-sectional area of the injured TA muscles of E-MSC–transplanted animals increased earlier than that of control animals. E-MSCs also promotes re-innervation of the peripheral nerves of injured muscles. Concerning function of the TA muscles, we reveal that transplantation of E-MSCs promotes the recovery of muscles. This is the first report to demonstrate by analysis of spontaneous walking that transplanted cells can accelerate the functional recovery of injured muscles. Taken together, the results show that E-MSCs have a high potential for differentiation into skeletal muscles in vivo as well as in vitro. The transplantation of E-MSCs facilitated the functional recovery of injured muscles. Therefore, E-MSCs are an efficient cell source in transplantation. PMID:23914336

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

    PubMed

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

    2011-02-01

    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.

  18. Stem Cell Antigen-1 in Skeletal Muscle Function

    PubMed Central

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

    2013-01-01

    Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1 in normal, post-natal muscle has not been thoroughly investigated. We systematically compared Sca-1-/- (KO) and Sca-1+/+ (WT) mice and hindlimb muscles to elucidate the tissue, contractile, and functional effects of Sca-1 in young and aging animals. Comparison of muscle volume, fibrosis, myofiber cross-sectional area, and Pax7+ myoblast number showed little differences between ages or genotypes. Exercise protocols, however, demonstrated decreased stamina in KO versus WT mice, with young KO mice achieving results similar to aging WT animals. In addition, KO mice did not improve with practice, while WT animals demonstrated conditioning over time. Surprisingly, myomechanical analysis of isolated muscles showed that KO young muscle generated more force and experienced less fatigue. However, KO muscle also demonstrated incomplete relaxation with fatigue. These findings suggest that Sca-1 is necessary for muscle conditioning with exercise, and that deficient conditioning in Sca-1 KO animals becomes more pronounced with age. PMID:24042315

  19. Myogenic Progenitors from Mouse Pluripotent Stem Cells for Muscle Regeneration.

    PubMed

    Magli, Alessandro; Incitti, Tania; Perlingeiro, Rita C R

    2016-01-01

    Muscle homeostasis is maintained by resident stem cells which, in both pathologic and non-pathologic conditions, are able to repair or generate new muscle fibers. Although muscle stem cells have tremendous regenerative potential, their application in cell therapy protocols is prevented by several restrictions, including the limited ability to grow ex vivo. Since pluripotent stem cells have the unique potential to both self-renew and expand almost indefinitely, they have become an attractive source of progenitors for regenerative medicine studies. Our lab has demonstrated that embryonic stem cell (ES)-derived myogenic progenitors retain the ability to repair existing muscle fibers and contribute to the pool of resident stem cells. Because of their relevance in both cell therapy and disease modeling, in this chapter we describe the protocol to derive myogenic progenitors from murine ES cells followed by their intramuscular delivery in a murine muscular dystrophy model. PMID:27492174

  20. Skeletal muscle microvascular oxygenation dynamics in heart failure: exercise training and nitric oxide-mediated function.

    PubMed

    Hirai, Daniel M; Copp, Steven W; Holdsworth, Clark T; Ferguson, Scott K; McCullough, Danielle J; Behnke, Bradley J; Musch, Timothy I; Poole, David C

    2014-03-01

    Chronic heart failure (CHF) impairs nitric oxide (NO)-mediated regulation of skeletal muscle O2 delivery-utilization matching such that microvascular oxygenation falls faster (i.e., speeds PO2mv kinetics) during increases in metabolic demand. Conversely, exercise training improves (slows) muscle PO2mv kinetics following contractions onset in healthy young individuals via NO-dependent mechanisms. We tested the hypothesis that exercise training would improve contracting muscle microvascular oxygenation in CHF rats partly via improved NO-mediated function. CHF rats (left ventricular end-diastolic pressure = 17 ± 2 mmHg) were assigned to sedentary (n = 11) or progressive treadmill exercise training (n = 11; 5 days/wk, 6-8 wk, final workload of 60 min/day at 35 m/min; -14% grade downhill running) groups. PO2mv was measured via phosphorescence quenching in the spinotrapezius muscle at rest and during 1-Hz twitch contractions under control (Krebs-Henseleit solution), sodium nitroprusside (SNP; NO donor; 300 μM), and N(G)-nitro-l-arginine methyl ester (L-NAME, nonspecific NO synthase blockade; 1.5 mM) superfusion conditions. Exercise-trained CHF rats had greater peak oxygen uptake and spinotrapezius muscle citrate synthase activity than their sedentary counterparts (p < 0.05 for both). The overall speed of the PO2mv fall during contractions (mean response time; MRT) was slowed markedly in trained compared with sedentary CHF rats (sedentary: 20.8 ± 1.4, trained: 32.3 ± 3.0 s; p < 0.05), and the effect was not abolished by L-NAME (sedentary: 16.8 ± 1.5, trained: 31.0 ± 3.4 s; p > 0.05). Relative to control, SNP increased MRT in both groups such that trained CHF rats had slower kinetics (sedentary: 43.0 ± 6.8, trained: 55.5 ± 7.8 s; p < 0.05). Improved NO-mediated function is not obligatory for training-induced improvements in skeletal muscle microvascular oxygenation (slowed PO2mv kinetics) following contractions onset in rats with CHF.

  1. The measurement and dynamic implications of thin filament lengths in heart muscle.

    PubMed Central

    Robinson, T F; Winegrad, S

    1979-01-01

    1. The lengths of the thin filaments in amphibian and mammalian cardiac muscle have been determined from electron micrographs of serial transverse sections. Thin filament lengths in frog atrial trabeculae range from 0.8 to greater than 1.3 micrometers, with a maximum possible error of 0.14--0.15 micrometer. In rat atrial tissue the span is from 0.6 to more than 1.1 micrometer, whereas in rat papillary muscle the breadth of the distribution is much narrower, from 0.9 to greater than 1.1 micrometer. Double overlap of thin filaments should, therefore, exist over a wide range of sarcomere lenghts. Thin filaments from opposite halves of a sarcomere accommodate each other by flexing up to an angle of about 2 degrees and moving from the trigonal position among the thick filaments to the centre of the region between two thick filaments. Such rearrangement probably contributes to the internal resistance to shortening in the muscle. 2. Except for the variation in thin filament lengths, the over-all morphology of the cardiac sarcomere is generally similar to that found in skeletal muscle. Thick filaments in heart muscle are uniform in length, and their profiles change along their lengths. They are generally round in the M band, triangular adjacent to the M band, round again in the overlap region, and either round or triangular near the tapered tips. The M bridges in rat cardiac tissue link neighbouring thick filaments to form a symmetric hexagonal array, whereas in the frog atrium, the M bridge connexions are incomplete and often form isolated triangular clusters. 3. Computed sarcomere length-developed tension curves were calculated using the thin filament length distributions and the assumptions basic to the sliding filament theory of muscle contraction. The curves for atrial tissue have plateau regions approximately as wide as the one-half micron variation in thin filament length. 4. Work done against the internal loads during systole may be stored as potential energy and

  2. Influence of plating density on individual cell growth, cell division and differentiation of neonatal rat heart primary cultures.

    PubMed

    Millart, H; Seraydarian, M W

    1986-01-01

    The influence of plating cell density of an originally enriched myocardial cell population has been studied in neonatal rat heart cells in culture. Low density (LDM) is defined as a density (24 h after plating) of 209 +/- 44 cells/mm2 (mean +/- SEM) and is compared with high density (HDM), 419 +/- 67 cells/mm2. Cell growth is evaluated by the total cell number, the percentage of myocardial cells (M) in culture (PAS method) and the protein content per cell. Some differentiation parameters such as beating rates, glycogen concentration, enzymatic activities (cytochrome C oxidase and glycogen phosphorylase) are studied with time in culture (48, 96 and 192 hr). High density was designed to yield a complete confluency of the cells within 24 hr after plating and to minimize cell division of the non-muscle cells (F). At high density, cell division of F cells is effectively limited, thus leading to a more stable model regarding the cell density per plate and the percentage of M cells: 85.7 +/- 4% and 33.4 +/- 6% in LDM cultures compared with 86.5 +/- 4.7% and 51.7 +/- 9.8% in HDM cultures at 24 and 192 hr (mean +/- SEM). Heart cells increase similarly in size with age in culture in both groups. In HDM cultures the spontaneous contractions begin sooner (24 hr) than in LDM cultures and are more rapidly synchronized. The beating rate is higher in HDM cultures between 48 and 96 hr; however, after this time it falls in HDM and does not fall in LDM. Thus the overgrowth of muscle cells by non-muscle cells is not responsible for loss of beating with time in culture but more likely high density could be a limiting factor for isotonic contraction. There is more glycogen per myocyte in LDM than in HDM cultures. The cell density influences the enzymatic activities of cytochrome C oxidase and glycogen phosphorylase. The cytochrome oxidase activity is higher in HDM cultures than in LDM cultures at 96 hr whereas glycogen phosphorylase activity is higher in LDM cultures at time 96 and 192

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

    PubMed

    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.

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

    PubMed

    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.

  5. About Heart Attacks

    MedlinePlus

    ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ... survive. A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or ...

  6. Effect of static magnetic field and/or cadmium in the antioxidant enzymes activity in rat heart and skeletal muscle.

    PubMed

    Amara, Salem; Garrel, Catherine; Favier, Alain; Ben Rhouma, Khémais; Sakly, Mohsen; Abdelmelek, Hafedh

    2009-12-01

    Currently, environmental and industrial pollution along with increase and causes multiple stress conditions, the combined exposure to magnetic field and other toxic agents is recognised as an important research area, with a view to better protecting human health against their probable unfavourable effects. In the present study, we investigated the effect of co-exposure to static magnetic field (SMF) and cadmium (Cd) on the antioxidant enzymes activity and the malondialdehyde (MDA) concentration in rat skeletal and cardiac muscles. The exposure of rats to SMF (128 mT, 1 h/day during 30 consecutive days) decreased the activities of glutathione peroxidase (GPx) and the superoxide dismutase (CuZn-SOD) in heart muscle. Sub-chronic exposure to SMF increased the MDA concentration in rat cardiac muscle. Cd treatment (CdCl2, 40 mg/l, per os) during 4 weeks decreased the activities of catalase (CAT) in skeletal muscle and the CuZn-SOD in the heart. Moreover, Cd administration increased MDA concentration in the both structures. The combined effect of SMF (128 mT, 1 h/day during 30 consecutive days) and Cd (40 mg/l, per os) disrupt the antioxidant enzymes activity in rat skeletal and cardiac muscles. Moreover, we noted a huge increase in MDA concentration in the heart and skeletal muscle compared to control group. Thus it is possible that the SMF- and/or Cd-induced depletion of antioxidant enzymes activity in muscle tissues might, like the enhanced lipid peroxidation, importantly contribute to oxidative damage. The combined effect of SMF and Cd altered significantly the antioxidant enzymatic capacity and induced lipid peroxidation in both skeletal and cardiac muscle.

  7. Robust derivation of epicardium and its differentiated smooth muscle cell progeny from human pluripotent stem cells.

    PubMed

    Iyer, Dharini; Gambardella, Laure; Bernard, William G; Serrano, Felipe; Mascetti, Victoria L; Pedersen, Roger A; Talasila, Amarnath; Sinha, Sanjay

    2015-04-15

    The epicardium has emerged as a multipotent cardiovascular progenitor source with therapeutic potential for coronary smooth muscle cell, cardiac fibroblast (CF) and cardiomyocyte regeneration, owing to its fundamental role in heart development and its potential ability to initiate myocardial repair in injured adult tissues. Here, we describe a chemically defined method for generating epicardium and epicardium-derived smooth muscle cells (EPI-SMCs) and CFs from human pluripotent stem cells (HPSCs) through an intermediate lateral plate mesoderm (LM) stage. HPSCs were initially differentiated to LM in the presence of FGF2 and high levels of BMP4. The LM was robustly differentiated to an epicardial lineage by activation of WNT, BMP and retinoic acid signalling pathways. HPSC-derived epicardium displayed enhanced expression of epithelial- and epicardium-specific markers, exhibited morphological features comparable with human foetal epicardial explants and engrafted in the subepicardial space in vivo. The in vitro-derived epicardial cells underwent an epithelial-to-mesenchymal transition when treated with PDGF-BB and TGFβ1, resulting in vascular SMCs that displayed contractile ability in response to vasoconstrictors. Furthermore, the EPI-SMCs displayed low density lipoprotein uptake and effective lowering of lipoprotein levels upon treatment with statins, similar to primary human coronary artery SMCs. Cumulatively, these findings suggest that HPSC-derived epicardium and EPI-SMCs could serve as important tools for studying human cardiogenesis, and as a platform for vascular disease modelling and drug screening.

  8. Skeletal muscle satellite cells cultured in simulated microgravity

    NASA Technical Reports Server (NTRS)

    Molnar, Greg; Hartzell, Charles R.; Schroedl, Nancy A.; Gonda, Steve R.

    1993-01-01

    Satellite cells are postnatal myoblasts responsible for providing additional nuclei to growing or regenerating muscle cells. Satellite cells retain the capacity to proliferate and differentiate in vitro and therefore provide a useful model to study postnatal muscle development. Most culture systems used to study postnatal muscle development are limited by the two-dimensional (2-D) confines of the culture dish. Limiting proliferation and differentiation of satellite cells in 2-D could potentially limit cell-cell contacts important for developing the level of organization in skeletal muscle obtained in vivo. Culturing satellite cells on microcarrier beads suspended in the High-Aspect-Ratio-Vessel (HARV) designed by NASA provides a low shear, three-dimensional (3-D) environment to study muscle development. Primary cultures established from anterior tibialis muscles of growing rats (approximately 200 gm) were used for all studies and were composed of greater than 75 % satellite cells. Different inoculation densities did not affect the proliferative potential of satellite cells in the HARV. Plating efficiency, proliferation, and glucose utilization were compared between 2-D flat culture and 3-D HARV culture. Plating efficiency (cells attached - cells plated x 100) was similar between the two culture systems. Proliferation was reduced in HARV cultures and this reduction was apparent for both satellite cells and non-satellite cells. Furthermore, reduction in proliferation within the HARV could not be attributed to reduced substrate availability since glucose levels in media from HARV and 2-D cell culture were similar. Morphologically, microcarrier beads within the HARVS were joined together by cells into three-dimensional aggregates composed of greater than 10 beads/aggregate. Aggregation of beads did not occur in the absence of cells. Myotubes were often seen on individual beads or spanning the surface of two beads. In summary, proliferation and differentiation of

  9. Effect of combining traction and vibration on back muscles, heart rate and blood pressure.

    PubMed

    Wang, Lizhen; Zhao, Meiya; Ma, Jian; Tian, Shan; Xiang, Pin; Yao, Wei; Fan, Yubo

    2014-11-01

    Eighty-five percent of the population has experienced low back pain (LBP), which may result in decreasing muscle strength and endurance, functional capacity of the spine, and so on. Traction and vibration are commonly used to relieve the low back pain. The effect of the combing traction and vibration on back muscles, heart rate (HR) and blood pressure (BP) was investigated in this study. Thirty healthy subjects participated in 12 trials lying supine on the spine-combing bed with different tilt angle (0°, 10°, 20° and 30°) and vibration modes (along with the sagittal and coronal axis with 0 Hz, 2 Hz and 12 Hz separately). EMG was recorded during each trial. Power spectral frequency analysis was applied to evaluate muscle fatigue by the shift of median power frequency (MPF). Pulse pressure (PP) was calculated from BP. HR and PP were used to estimate the effect of the combination of traction and vibration on the cardio-vascular system. It was shown that vibration could increase HR and decrease PP. The combination of traction and vibration (2 Hz vibration along Z-axis and 12 Hz vibration along Y-axis) had no significant effect on the cardio-vascular system. The MPF of lumbar erector spinae (LES) and upper trapezius (UT) decreased significantly when the angle reached 20° under the condition of 2 Hz vibration along Z-axis compared with it of 0°. Furthermore, the MPF also decreased significantly compared with it of static mode at 20° for LES and at 30° for UT. However at 12 Hz vibration along Y-axis, the MPF had significant increase when the angle reached 20° in LES and 30° in UT compared to 0°. For LES, the MPF also had significant difference when the angle was increased from 10° to 20°. Therefore, combining 2 Hz vibration along Z-axis and traction (tilt angles that less than 20°) may to reduce muscle fatigue both for LES and UT compared with either vibration or traction alone. The combination of 12 Hz vibration along Y-axis and traction (tilt angles

  10. Phosphatidylinositol 4,5-bisphosphate formation in rabbit skeletal and heart muscle membranes.

    PubMed

    Varsányi, M; Messer, M; Brandt, N R; Heilmeyer, L M

    1986-08-14

    Incubation of rabbit skeletal muscle microsomes or isolated triads with gamma 32P-ATP/Mg2+ in the absence and in the presence of added phosphatidylinositol resulted in the formation of phosphatidylinositol 4-phosphate catalyzed by phosphatidylinositol kinase. When phosphatidylinositol 4-phosphate was added as exogenous substrate, phosphatidylinositol 4,5-bisphosphate was also formed demonstrating the presence of a membrane bound phosphatidylinositol 4-phosphate kinase. Triads were broken mechanically in a French press and separated on a continuous sucrose gradient. Incubation of these fractions with gamma 32P-ATP/Mg2+ resulted in a rapid labeling of phospholipid in a membrane fraction banding between transverse tubules and the terminal cisternae. Partial triad breakage and triad reformation experiments indicated that this phosphatidylinositol kinase was associated with T-tubules. When exogenous phosphatidylinositol 4-phosphate was employed as substrate phosphatidylinositol 4,5-bisphosphate and phosphatidic acid were formed, indicating the presence of all the enzymes of the polyphosphoinositide signaling system in this special membrane fraction. In contrast, heart muscle microsomes or plasma membranes can catalyze this reaction sequence from endogenous formed phosphatidylinositol 4-phosphate.

  11. Progressive improvement in hemodynamic response to muscle metaboreflex in heart transplant recipients.

    PubMed

    Crisafulli, Antonio; Tocco, Filippo; Milia, Raffaele; Angius, Luca; Pinna, Marco; Olla, Sergio; Roberto, Silvana; Marongiu, Elisabetta; Porcu, Maurizio; Concu, Alberto

    2013-02-01

    Exercise capacity remains lower in heart transplant recipients (HTRs) following transplant compared with normal subjects, despite improved cardiac function. Moreover, metaboreceptor activity in the muscle has been reported to increase. The aim of the present investigation was to assess exercise capacity together with metaboreflex activity in HTR patients for 1 yr following heart transplant, to test the hypothesis that recovery in exercise capacity was paralleled by improvements in response to metaboreflex. A cardiopulmonary test for exercise capacity and Vo(2max) and hemodynamic response to metaboreflex activation obtained by postexercise ischemia were gathered in six HTRs and nine healthy controls (CTL) four times: at the beginning of the study (T0, 42 ± 6 days after transplant), at the 3rd, 6th, and 12th month after TO (T1, T2, and T3). The main results were: 1) exercise capacity and Vo(2max) were seen to progressively increase in HTRs; 2) at T0 and T1, HTRs achieved a higher blood pressure response in response to metaboreflex compared with CTL, and this difference disappeared at T2 and T3; and 3) this exaggerated blood pressure response was the result of a systemic vascular resistance increment. This study demonstrates that exercise capacity progressively improves in HTRs after transplant and that this phenomenon is accompanied by a progressive reduction of the metaboreflex-induced increase in blood pressure and systemic vascular resistance. These facts indicate that, despite improved cardiac function, resetting of cardiovascular regulation in HTRs requires months. PMID:23195627

  12. DECREASED EXPRESSION LEVEL OF APOPTOSIS-RELATED GENES AND/OR PROTEINS IN SKELETAL MUSCLES, BUT NOT IN HEARTS, OF GROWTH HORMONE RECEPTOR KNOCKOUT MICE

    PubMed Central

    Gesing, Adam; Masternak, Michal M.; Wang, Feiya; Lewinski, Andrzej; Karbownik-Lewinska, Malgorzata; Bartke, Andrzej

    2013-01-01

    The long-lived growth hormone (GH) receptor knockout (GHRKO; KO) mice are GH resistant due to targeted disruption of the GH receptor (Ghr) gene. Apoptosis is a physiological process in which cells play an active role in their own death and is a normal component of the development and health of multicellular organisms. Aging is associated with the progressive loss of strength of skeletal and heart muscles. Calorie restriction (CR) is a well known experimental model to delay aging and increase lifespan. The aim of the study was to examine the expression of the following apoptosis-related genes: caspase-3, caspase-9, caspase-8, bax, bcl-2, Smac/DIABLO, p53 and cytochrome c1 (cyc1) in the skeletal muscles and hearts of female normal and GHRKO mice, fed ad libitum or subjected to 40% CR for 6 months, starting at 2 months of age. Moreover, skeletal muscle caspase-3, caspase-9, caspase-8, bax, bcl-2, Smac/DIABLO, Apaf-1, bad, phospho-bad (pbad), phospho-p53 (pp53) and cytochrome c (cyc) protein expression levels were assessed. Results Expression of caspase-3, caspase-9, bax and Smac/DIABLO genes and proteins was decreased in GHRKO’s skeletal muscles. The Apaf-1 protein expression also was diminished in this tissue. In contrast, bcl-2 and pbad protein levels were increased in skeletal muscles in knockouts. No changes were demonstrated for the examined genes expression in GHRKO’s hearts except for the increased level of cyc1 mRNA. CR did not alter the expression of the examined genes and proteins in skeletal muscles of knockouts vs. normal (N) mice. In heart homogenates, CR increased caspase-3 mRNA level as compared to ad libitum (AL) mice. Conclusion decreased expression of certain pro-apoptotic genes and/or proteins may constitute the potential mechanism of prolonged longevity in GHRKO mice, protecting these animals from aging; this potential beneficial mechanism is not affected by calorie restriction. PMID:21321312

  13. Sphingosylphosphorylcholine inhibits macrophage adhesion to vascular smooth muscle cells.

    PubMed

    Wirrig, Christiane; McKean, Jenny S; Wilson, Heather M; Nixon, Graeme F

    2016-09-01

    Inflammation in de-endothelialised arteries contributes to the development of cardiovascular diseases. The process that initiates this inflammatory response is the adhesion of monocytes/macrophages to exposed vascular smooth muscle cells, typically stimulated by cytokines such as tumour necrosis factor-α (TNF). The aim of this study was to determine the effect of the sphingolipid sphingosylphosphorylcholine (SPC) on the interaction of monocytes/macrophages with vascular smooth muscle cells. Rat aortic smooth muscle cells and rat bone marrow-derived macrophages were co-cultured using an in vitro assay following incubation with sphingolipids to assess inter-cellular adhesion. We reveal that SPC inhibits the TNF-induced adhesion of macrophages to smooth muscle cells. This anti-adhesive effect was the result of SPC-induced changes to the smooth muscle cells (but not the macrophages) and was mediated, at least partly, via the sphingosine 1-phosphate receptor subtype 2. Lipid raft domains were also required. Although SPC did not alter expression or membrane distribution of the adhesion proteins intercellular adhesion molecule-1 and vascular cellular adhesion protein-1 in smooth muscle cells, SPC preincubation inhibited the TNF-induced increase in inducible nitric oxide synthase (NOS2) resulting in a subsequent decrease in nitric oxide production. Inhibiting NOS2 activation in smooth muscle cells led to a decrease in the adhesion of macrophages to smooth muscle cells. This study has therefore delineated a novel pathway which can inhibit the interaction between macrophages and vascular smooth muscle cells via SPC-induced repression of NOS2 expression. This mechanism could represent a potential drug target in vascular disease.

  14. Sphingosylphosphorylcholine inhibits macrophage adhesion to vascular smooth muscle cells.

    PubMed

    Wirrig, Christiane; McKean, Jenny S; Wilson, Heather M; Nixon, Graeme F

    2016-09-01

    Inflammation in de-endothelialised arteries contributes to the development of cardiovascular diseases. The process that initiates this inflammatory response is the adhesion of monocytes/macrophages to exposed vascular smooth muscle cells, typically stimulated by cytokines such as tumour necrosis factor-α (TNF). The aim of this study was to determine the effect of the sphingolipid sphingosylphosphorylcholine (SPC) on the interaction of monocytes/macrophages with vascular smooth muscle cells. Rat aortic smooth muscle cells and rat bone marrow-derived macrophages were co-cultured using an in vitro assay following incubation with sphingolipids to assess inter-cellular adhesion. We reveal that SPC inhibits the TNF-induced adhesion of macrophages to smooth muscle cells. This anti-adhesive effect was the result of SPC-induced changes to the smooth muscle cells (but not the macrophages) and was mediated, at least partly, via the sphingosine 1-phosphate receptor subtype 2. Lipid raft domains were also required. Although SPC did not alter expression or membrane distribution of the adhesion proteins intercellular adhesion molecule-1 and vascular cellular adhesion protein-1 in smooth muscle cells, SPC preincubation inhibited the TNF-induced increase in inducible nitric oxide synthase (NOS2) resulting in a subsequent decrease in nitric oxide production. Inhibiting NOS2 activation in smooth muscle cells led to a decrease in the adhesion of macrophages to smooth muscle cells. This study has therefore delineated a novel pathway which can inhibit the interaction between macrophages and vascular smooth muscle cells via SPC-induced repression of NOS2 expression. This mechanism could represent a potential drug target in vascular disease. PMID:27402344

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

    PubMed

    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.

  16. High Prevalence of Respiratory Muscle Weakness in Hospitalized Acute Heart Failure Elderly Patients

    PubMed Central

    Verissimo, Pedro; Timenetsky, Karina T.; Casalaspo, Thaisa Juliana André; Gonçalves, Louise Helena Rodrigues; Yang, Angela Shu Yun; Eid, Raquel Caserta

    2015-01-01

    Introduction Respiratory Muscle Weakness (RMW) has been defined when the maximum inspiratory pressure (MIP) is lower than 70% of the predictive value. The prevalence of RMW in chronic heart failure patients is 30 to 50%. So far there are no studies on the prevalence of RMW in acute heart failure (AHF) patients. Objectives Evaluate the prevalence of RMW in patients admitted because of AHF and the condition of respiratory muscle strength on discharge from the hospital. Methods Sixty-three patients had their MIP measured on two occasions: at the beginning of the hospital stay, after they had reached respiratory, hemodynamic and clinical stability and before discharge from the hospital. The apparatus and technique to measure MIP were adapted because of age-related limitations of the patients. Data on cardiac ejection fraction, ECG, brain natriuretic peptide (BNP) levels and on the use of noninvasive ventilation (NIV) were collected. Results The mean age of the 63 patients under study was 75 years. On admission the mean ejection fraction was 33% (95% CI: 31–35) and the BNP hormone median value was 726.5 pg/ml (range: 217 to 2283 pg/ml); 65% of the patients used NIV. The median value of MIP measured after clinical stabilization was -52.7 cmH2O (range: -20 to -120 cmH2O); 76% of the patients had MIP values below 70% of the predictive value. On discharge, after a median hospital stay of 11 days, the median MIP was -53.5 cmH2O (range:-20 to -150 cmH2O); 71% of the patients maintained their MIP values below 70% of the predictive value. The differences found were not statistically significant. Conclusion Elderly patients admitted with AHF may present a high prevalence of RMW on admission; this condition may be maintained at similar levels on discharge in a large percentage of these patients, even after clinical stabilization of the heart condition. PMID:25671566

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

    PubMed

    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.

  18. Repressed mRNAs of muscle cells

    SciTech Connect

    Bag, J.; Pramanik, S.

    1986-05-01

    In rat L-6 muscle cells cytoplasmic mRNAs have been found in two compartments polysome bound and free (or non polysomal). The mRNAs were differentially distributed in these two compartments. The mRNA for a polypeptide of molecular weight 60,000 daltons was present predominantly in the free or non polysomal fraction. We have prepared a cDNA library from the non polysomal mRNAs of L-6 myoblasts. This library was screened by using /sup 32/P labeled cDNA prepared from both polysomal and non polysomal mRNAs. We were able to isolate ten colonies which produced strong signals only when /sup 32/P cDNA from non polysomal mRNAs were used. The DNA from two of these colonies hybridized to two different mRNAs. These two clones were used to quantitate the mRNAs in polysomal and non polysomal fractions. It was found that one clone (D-12) hybridized to a mRNA 60% of which was present in the non polysomal fraction. On the other hand a second clone (P-5) hybridized to a mRNA 80% of which was repressed (non polysomal). Further studies are in progress to examine the mechanism of translational block of these two mRNAs.

  19. Apoptosis in capillary endothelial cells in ageing skeletal muscle

    PubMed Central

    Wang, Huijuan; Listrat, Anne; Meunier, Bruno; Gueugneau, Marine; Coudy-Gandilhon, Cécile; Combaret, Lydie; Taillandier, Daniel; Polge, Cécile; Attaix, Didier; Lethias, Claire; Lee, Kijoon; Goh, Kheng Lim; Béchet, Daniel

    2014-01-01

    The age-related loss of skeletal muscle mass and function (sarcopenia) is a consistent hallmark of ageing. Apoptosis plays an important role in muscle atrophy, and the intent of this study was to specify whether apoptosis is restricted to myofibre nuclei (myonuclei) or occurs in satellite cells or stromal cells of extracellular matrix (ECM). Sarcopenia in mouse gastrocnemius muscle was characterized by myofibre atrophy, oxidative type grouping, delocalization of myonuclei and ECM fibrosis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelling (TUNEL) indicated a sharp rise in apoptosis during ageing. TUNEL coupled with immunostaining for dystrophin, paired box protein-7 (Pax7) or laminin-2α, respectively, was used to identify apoptosis in myonuclei, satellite cells and stromal cells. In adult muscle, apoptosis was not detected in myofibres, but was restricted to stromal cells. Moreover, the age-related rise in apoptotic nuclei was essentially due to stromal cells. Myofibre-associated apoptosis nevertheless occurred in old muscle, but represented < 20% of the total muscle apoptosis. Specifically, apoptosis in old muscle affected a small proportion (0.8%) of the myonuclei, but a large part (46%) of the Pax7+ satellite cells. TUNEL coupled with CD31 immunostaining further attributed stromal apoptosis to capillary endothelial cells. Age-dependent rise in apoptotic capillary endothelial cells was concomitant with altered levels of key angiogenic regulators, perlecan and a perlecan domain V (endorepellin) proteolytic product. Collectively, our results indicate that sarcopenia is associated with apoptosis of satellite cells and impairment of capillary functions, which is likely to contribute to the decline in muscle mass and functionality during ageing. PMID:24245531

  20. Matrix metalloproteinase inhibition negatively affects muscle stem cell behavior.

    PubMed

    Bellayr, Ian; Holden, Kyle; Mu, Xiaodong; Pan, Haiying; Li, Yong

    2013-01-01

    Skeletal muscle is a large and complex system that is crucial for structural support, movement and function. When injured, the repair of skeletal muscle undergoes three phases: inflammation and degeneration, regeneration and fibrosis formation in severe injuries. During fibrosis formation, muscle healing is impaired because of the accumulation of excess collagen. A group of zinc-dependent endopeptidases that have been found to aid in the repair of skeletal muscle are matrix metalloproteinases (MMPs). MMPs are able to assist in tissue remodeling through the regulation of extracellular matrix (ECM) components, as well as contributing to cell migration, proliferation, differentiation and angiogenesis. In the present study, the effect of GM6001, a broad-spectrum MMP inhibitor, on muscle-derived stem cells (MDSCs) is investigated. We find that MMP inhibition negatively impacts skeletal muscle healing by impairing MDSCs in migratory and multiple differentiation abilities. These results indicate that MMP signaling plays an essential role in the wound healing of muscle tissue because their inhibition is detrimental to stem cells residing in skeletal muscle. PMID:23329998

  1. Myocardial regeneration by activation of multipotent cardiac stem cells in ischemic heart failure

    NASA Astrophysics Data System (ADS)

    Urbanek, Konrad; Torella, Daniele; Sheikh, Farooq; de Angelis, Antonella; Nurzynska, Daria; Silvestri, Furio; Beltrami, C. Alberto; Bussani, Rossana; Beltrami, Antonio P.; Quaini, Federico; Bolli, Roberto; Leri, Annarosa; Kajstura, Jan; Anversa, Piero

    2005-06-01

    In this study, we tested whether the human heart possesses a cardiac stem cell (CSC) pool that promotes regeneration after infarction. For this purpose, CSC growth and senescence were measured in 20 hearts with acute infarcts, 20 hearts with end-stage postinfarction cardiomyopathy, and 12 control hearts. CSC number increased markedly in acute and, to a lesser extent, in chronic infarcts. CSC growth correlated with the increase in telomerase-competent dividing CSCs from 1.5% in controls to 28% in acute infarcts and 14% in chronic infarcts. The CSC mitotic index increased 29-fold in acute and 14-fold in chronic infarcts. CSCs committed to the myocyte, smooth muscle, and endothelial cell lineages increased 85-fold in acute infarcts and 25-fold in chronic infarcts. However, p16INK4a-p53-positive senescent CSCs also increased and were 10%, 18%, and 40% in controls, acute infarcts, and chronic infarcts, respectively. Old CSCs had short telomeres and apoptosis involved 0.3%, 3.8%, and 9.6% of CSCs in controls, acute infarcts, and chronic infarcts, respectively. These variables reduced the number of functionally competent CSCs from 26,000/cm3 of viable myocardium in acute to 7,000/cm3 in chronic infarcts, respectively. In seven acute infarcts, foci of spontaneous myocardial regeneration that did not involve cell fusion were identified. In conclusion, the human heart possesses a CSC compartment, and CSC activation occurs in response to ischemic injury. The loss of functionally competent CSCs in chronic ischemic cardiomyopathy may underlie the progressive functional deterioration and the onset of terminal failure. cardiac progenitor cells | human heart | myocardial infarction

  2. Supplemental Protein during Heavy Cycling Training and Recovery Impacts Skeletal Muscle and Heart Rate Responses but Not Performance.

    PubMed

    D'Lugos, Andrew C; Luden, Nicholas D; Faller, Justin M; Akers, Jeremy D; McKenzie, Alec I; Saunders, Michael J

    2016-01-01

    The effects of protein supplementation on cycling performance, skeletal muscle function, and heart rate responses to exercise were examined following intensified (ICT) and reduced-volume training (RVT). Seven cyclists performed consecutive periods of normal training (NT), ICT (10 days; average training duration 220% of NT), and RVT (10 days; training duration 66% of NT). In a crossover design, subjects consumed supplemental carbohydrate (CHO) or an equal amount of carbohydrate with added protein (CP) during and following each exercise session (CP = +0.94 g/kg/day protein during ICT; +0.39 g/kg/day during RVT). A 30-kilometer time trial performance (following 120 min at 50% Wmax) was modestly impaired following ICT (+2.4 ± 6.4% versus NT) and returned to baseline levels following RVT (-0.7 ± 4.5% versus NT), with similar responses between CHO and CP. Skeletal muscle torque at 120 deg/s benefited from CP, compared to CHO, following ICT. However, this effect was no longer present at RVT. Following ICT, muscle fiber cross-sectional area was increased with CP, while there were no clear changes with CHO. Reductions in constant-load heart rates (at 50% Wmax) following RVT were likely greater with CP than CHO (-9 ± 9 bpm). Overall it appears that CP supplementation impacted skeletal muscle and heart rate responses during a period of heavy training and recovery, but this did not result in meaningful changes in time trial performance. PMID:27618091

  3. Supplemental Protein during Heavy Cycling Training and Recovery Impacts Skeletal Muscle and Heart Rate Responses but Not Performance

    PubMed Central

    D’Lugos, Andrew C.; Luden, Nicholas D.; Faller, Justin M.; Akers, Jeremy D.; McKenzie, Alec I.; Saunders, Michael J.

    2016-01-01

    The effects of protein supplementation on cycling performance, skeletal muscle function, and heart rate responses to exercise were examined following intensified (ICT) and reduced-volume training (RVT). Seven cyclists performed consecutive periods of normal training (NT), ICT (10 days; average training duration 220% of NT), and RVT (10 days; training duration 66% of NT). In a crossover design, subjects consumed supplemental carbohydrate (CHO) or an equal amount of carbohydrate with added protein (CP) during and following each exercise session (CP = +0.94 g/kg/day protein during ICT; +0.39 g/kg/day during RVT). A 30-kilometer time trial performance (following 120 min at 50% Wmax) was modestly impaired following ICT (+2.4 ± 6.4% versus NT) and returned to baseline levels following RVT (−0.7 ± 4.5% versus NT), with similar responses between CHO and CP. Skeletal muscle torque at 120 deg/s benefited from CP, compared to CHO, following ICT. However, this effect was no longer present at RVT. Following ICT, muscle fiber cross-sectional area was increased with CP, while there were no clear changes with CHO. Reductions in constant-load heart rates (at 50% Wmax) following RVT were likely greater with CP than CHO (−9 ± 9 bpm). Overall it appears that CP supplementation impacted skeletal muscle and heart rate responses during a period of heavy training and recovery, but this did not result in meaningful changes in time trial performance. PMID:27618091

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

    PubMed

    Xu, Xiaoti; Wilschut, Karlijn J; Kouklis, Gayle; Tian, Hua; Hesse, Robert; Garland, Catharine; Sbitany, Hani; Hansen, Scott; Seth, Rahul; Knott, P Daniel; Hoffman, William Y; Pomerantz, Jason H

    2015-09-01

    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.

  5. Laminin regulates PDGFRβ+ cell stemness and muscle development

    PubMed Central

    Yao, Yao; Norris, Erin H.; E. Mason, Christopher; Strickland, Sidney

    2016-01-01

    Muscle-resident PDGFRβ+ cells, which include pericytes and PW1+ interstitial cells (PICs), play a dual role in muscular dystrophy. They can either undergo myogenesis to promote muscle regeneration or differentiate into adipocytes and other cells to compromise regeneration. How the differentiation and fate determination of PDGFRβ+ cells are regulated, however, remains unclear. Here, by utilizing a conditional knockout mouse line, we report that PDGFRβ+ cell-derived laminin inhibits their proliferation and adipogenesis, but is indispensable for their myogenesis. In addition, we show that laminin alone is able to partially reverse the muscle dystrophic phenotype in these mice at the molecular, structural and functional levels. Further RNAseq analysis reveals that laminin regulates PDGFRβ+ cell differentiation/fate determination via gpihbp1. These data support a critical role of laminin in the regulation of PDGFRβ+ cell stemness, identify an innovative target for future drug development and may provide an effective treatment for muscular dystrophy. PMID:27138650

  6. Resveratrol protects ROS-induced cell death by activating AMPK in H9c2 cardiac muscle cells

    PubMed Central

    Hwang, Jin-Taek; Kwon, Dae Young; Park, Ock Jin

    2007-01-01

    Resveratrol, one of polyphenols derived from red wine, has been shown to protect against cell death, possibly through the association with several signaling pathways. Currently numerous studies indicate that cardiovascular diseases are linked to the release of intracellular reactive oxygen species (ROS) often generated in states such as ischemia/reperfusion injury. In the present study, we investigated whether resveratrol has the capability to control intracellular survival signaling cascades involving AMP-activated kinase (AMPK) in the inhibitory process of cardiac injury. We hypothesized that resveratrol may exert a protective effect on damage to heart muscle through modulating of the AMPK signaling pathway. We mimicked ischemic conditions by inducing cell death with H2O2 in H9c2 muscle cells. In this experiment, resveratrol induced strong activation of AMPK and inhibited the occurrence of cell death caused by treatment with H2O2. Under the same conditions, inhibition of AMPK using dominant negative AMPK constructs dramatically abolished the effect of resveratrol on cell survival in H2O2-treated cardiac muscle cells. These results indicate that resveratrol-induced cell survival is mediated by AMPK in H9c2 cells and may exert a novel therapeutic effect on oxidative stress induced in cardiac disorders. PMID:18850225

  7. Embryonic stem cell therapy of heart failure in genetic cardiomyopathy.

    PubMed

    Yamada, Satsuki; Nelson, Timothy J; Crespo-Diaz, Ruben J; Perez-Terzic, Carmen; Liu, Xiao-Ke; Miki, Takashi; Seino, Susumu; Behfar, Atta; Terzic, Andre

    2008-10-01

    Pathogenic causes underlying nonischemic cardiomyopathies are increasingly being resolved, yet repair therapies for these commonly heritable forms of heart failure are lacking. A case in point is human dilated cardiomyopathy 10 (CMD10; Online Mendelian Inheritance in Man #608569), a progressive organ dysfunction syndrome refractory to conventional therapies and linked to mutations in cardiac ATP-sensitive K(+) (K(ATP)) channel subunits. Embryonic stem cell therapy demonstrates benefit in ischemic heart disease, but the reparative capacity of this allogeneic regenerative cell source has not been tested in inherited cardiomyopathy. Here, in a Kir6.2-knockout model lacking functional K(ATP) channels, we recapitulated under the imposed stress of pressure overload the gene-environment substrate of CMD10. Salient features of the human malignant heart failure phenotype were reproduced, including compromised contractility, ventricular dilatation, and poor survival. Embryonic stem cells were delivered through the epicardial route into the left ventricular wall of cardiomyopathic stressed Kir6.2-null mutants. At 1 month of therapy, transplantation of 200,000 cells per heart achieved teratoma-free reversal of systolic dysfunction and electrical synchronization and halted maladaptive remodeling, thereby preventing end-stage organ failure. Tracked using the lacZ reporter transgene, stem cells engrafted into host heart. Beyond formation of cardiac tissue positive for Kir6.2, transplantation induced cell cycle activation and halved fibrotic zones, normalizing sarcomeric and gap junction organization within remuscularized hearts. Improved systemic function induced by stem cell therapy translated into increased stamina, absence of anasarca, and benefit to overall survivorship. Embryonic stem cells thus achieve functional repair in nonischemic genetic cardiomyopathy, expanding indications to the therapy of heritable heart failure. Disclosure of potential conflicts of interest is

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

    SciTech Connect

    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.

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

    PubMed

    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.

  10. Use of fluorescent antimyosin and DNA labeling for the estimation of the myoblast and myocyte population of primary rat heart cell cultures

    SciTech Connect

    Masse, M.J.O.; Harary, I.

    1981-01-01

    Cell division in heart muscle cells progressively ceases during the development of the rat heart, leading to an adult stage with muscle cells incapable of cell division. We have quantitatively determined the number of dividing and nondividing heart muscle cells in cultures derived from different stages of the developing rat heart with the use of /sup 3/HTdR continuous labeling and fluorescent antimyosin staining. The cultures were derived from 14 and 17 day postcoital (dPC) rat embryos and from 1 and 4 day postnatal (dPN) rats. The percent nondividing cells increased with development and the age of the postnatal rat. The percent nondividing cells in 14 dPC equalled 21%, 17 dPC equalled 25%, 1 dPN equalled 44%, and 4 dPN equalled 60%. This method for the quantitative determination of dividing and nondividing cells in the developing rat heart provides a model that is useful for the study of the mechanism of the loss of cell division capacity.

  11. Stimulation of aortic smooth muscle cell mitogenesis by serotonin

    SciTech Connect

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

    1986-02-01

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

  12. [Effect of isoproterenol on contractility of the heart papillary muscles of a ground squirrel].

    PubMed

    Averin, A S; Zakharova, N M; Ignat'ev, D A; Tarlachkov, S V; Nakipova, O V

    2010-01-01

    The effect of isoproterenol (1 microM) on the force of isometric contractions (0.1-1.0 Hz, 30 +/- 1 degree C, 1.8 mM Ca2+) of papillary muscles of the right ventricle of the heart of the ground squirrel during summer activity (n = 5) and hibernation (activity between hibernation bouts, n = 4; torpor, n = 4; and arousal, n = 5) has been studied. It was shown that isoproterenol increases the force of contraction (positive inotropic effect) in active summer ground squirrels by 20 +/- 3 and 61 +/- 7% at stimulation frequencies of 0.4 and 1.0 Hz, respectively. The isoproterenol-induced increase in the force of contraction in animals during hibernation is brief (within 3 min after the onset of treatment) and this parameter decreases by 30-50% of the control level (negative inotropic effect) at stimulation frequencies from 0.3 and 0.8 Hz. The positive inotropic effect of isoproterenol in active summer ground squirrels is associated with a decrease in the relative value of the potentiating effect of the pause (qualitative indicator of calcium content in the sarcoplasmic reticulum), and the negative inotropic effect, with its increase. It was found that the inotropic effect of isoproterenol in all groups of animals examined (irrespective of its direction) is accompanied by an acceleration of the velocity of the contraction-relaxation cycle. The dependence of the effect of isoproterenol in the heart of hibernating animals on seasonal changes in the calcium homeostasis and the activity of the sympathetic nervous system is discussed.

  13. An improved isolated working rabbit heart preparation using red cell enhanced perfusate.

    PubMed Central

    Chen, V.; Chen, Y. H.; Downing, S. E.

    1987-01-01

    The performance of isolated working rabbit hearts perfused with Krebs-Henseleit (KH) buffer was compared with those in which the buffer was supplemented with washed human red blood cells (KH + RBC) at a hematocrit of 15 percent. When perfused with KH alone at 70 cm H2O afterload and paced at 240 beats/minute, coronary flow was more than double, whereas aortic flow was 40-60 percent of that in hearts perfused with KH + RBC, regardless of left atrial filling pressures (LAFP). Peak systolic pressure reached a plateau at 120 mm Hg in KH + RBC, but at 95 mm Hg in the KH group. Stroke work, however, was similar in the two groups. Despite the high coronary flow, oxygen uptake by hearts perfused with KH was substantially less and did not respond to increases in LAFP as in those perfused with KH + RBC. There was a 20 percent drop in ATP and glycogen content after 90 minutes' perfusion. In contrast, isolated hearts perfused with RBC-enriched buffer remained stable for at least 150 minutes. Irrespective of the perfusate, triacylglycerol content of the muscle remained at similar levels throughout the course of study. Increasing RBC in the perfusate from 15 percent to 25 percent had no additional effect on cardiac performance or oxygen consumption. Our findings demonstrate that in the isolated working rabbit heart inclusion of RBC in the perfusate improves mechanical and metabolic stability by providing an adequate oxygen supply. PMID:3604287

  14. Somite subdomains, muscle cell origins, and the four muscle regulatory factor proteins

    PubMed Central

    1994-01-01

    We show by immunohistology that distinct expression patterns of the four muscle regulatory factor (MRF) proteins identify subdomains of mouse somites. Myf-5 and MyoD are, at specific stages, each expressed in both myotome and dermatome cells. Myf-5 expression is initially restricted to dorsal cells in all somites, as is MyoD expression in neck somites. In trunk somites, however, MyoD is initially expressed in ventral cells. Myogenin and MRF4 are restricted to myotome cells, though the MRF4-expressing cells are initially less widely distributed than the myogenin-expressing cells, which are at all stages found throughout the myotome. All somitic myocytes express one or more MRFs. The transiently distinct expression patterns of the four MRF proteins identify dorsal and ventral subdomains of somites, and suggest that skeletal muscle cells in somites originate at multiple sites and via multiple molecular pathways. PMID:7929574

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

    PubMed

    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.

  16. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887

    NASA Technical Reports Server (NTRS)

    Mednieks, Maija I.; Popova, Irina A.; Grindeland, Richard E.

    1991-01-01

    The cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 is determined. Photoaffinity labeling of soluble and particular cell fractions with a (32P)-8-azido analog of cyclic AMP is followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. It is shown that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins exhibited some variability in tissues of individual animals, but showed no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. It is inferred that the cardiac cell integrity or its protein content is not compromised under flight conditions.

  17. MicroRNA-133a engineered mesenchymal stem cells augment cardiac function and cell survival in the infarct heart

    PubMed Central

    Dakhlallah, Duaa; Zhang, Jianying; Yu, Lianbo; Marsh, Clay B.; Angelos, Mark G.; Khan, Mahmood

    2015-01-01

    Cardiovascular disease is the number one cause of morbidity and mortality in the United States. The most common manifestation of cardiovascular disease is myocardial infarction (MI), which can ultimately lead to congestive heart failure (CHF). Cell therap (cardiomyoplasty) is a new potential therapeutic treatment alternative for the damaged heart. Recent preclinical and clinical studies have shown that mesenchymal stem cells (MSCs) are a promising cell type for cardiomyoplasty applications. However, a major limitation is the poor survival rate of transplanted stem cells in the infarcted heart. miR-133a is an abundantly expressed microRNA in the cardiac muscle and is down-regulated in patients with MI. We hypothesized that reprogramming MSCs using microRNA-mimics (double-stranded oligonucleotides) will improve survival of stem cells in the damaged heart. MSCs were transfected with miR-133a mimic and antagomirs and the levels of miR-133a were measured by qRT-PCR. Rat hearts were subjected to MI and MSCs transfected with miR-133a mimic or antagomir were implanted in the ischemic heart. Four weeks after MI, cardiac function, cardiac fibrosis, miR-133a levels and apoptosis related genes (Apaf-1, Capase-9 and Caspase-3) were measured in the heart. We found that transfecting MSCs with miR-133a mimic improves survival of MSCs as determined by the MTT assay. Similarly, transplantation of miR-133a mimic transfected MSCs in rat hearts subjected to MI led to a significant increase in cell engraftment, cardiac function and decreased fibrosis when compared with MSCs only or MI groups. At the molecular level, qRT-PCR data demonstrated a significant decrease in expression of the pro-apoptotic genes; Apaf-1, caspase-9 and caspase-3 in the miR-133a mimic transplanted group. Further, luciferase reporter assay confirmed that miR- 133a is a direct target for Apaf-1. Overall, bioengineering of stem cells through miRNAs manipulation could potentially improve the therapeutic outcome of

  18. Minimally invasive cell-seeded biomaterial systems for injectable/epicardial implantation in ischemic heart disease

    PubMed Central

    Ravichandran, Rajeswari; Venugopal, Jayarama Reddy; Sundarrajan, Subramanian; Mukherjee, Shayanti; Ramakrishna, Seeram

    2012-01-01

    Myocardial infarction (MI) is characterized by heart-wall thinning, myocyte slippage, and ventricular dilation. The injury to the heart-wall muscle after MI is permanent, as after an abundant cell loss the myocardial tissue lacks the intrinsic capability to regenerate. New therapeutics are required for functional improvement and regeneration of the infarcted myocardium, to overcome harmful diagnosis of patients with heart failure, and to overcome the shortage of heart donors. In the past few years, myocardial tissue engineering has emerged as a new and ambitious approach for treating MI. Several left ventricular assist devices and epicardial patches have been developed for MI. These devices and acellular/cellular cardiac patches are employed surgically and sutured to the epicardial surface of the heart, limiting the region of therapeutic benefit. An injectable system offers the potential benefit of minimally invasive release into the myocardium either to restore the injured extracellular matrix or to act as a scaffold for cell delivery. Furthermore, intramyocardial injection of biomaterials and cells has opened new opportunities to explore and also to augment the potentials of this technique to ease morbidity and mortality rates owing to heart failure. This review summarizes the growing body of literature in the field of myocardial tissue engineering, where biomaterial injection, with or without simultaneous cellular delivery, has been pursued to enhance functional and structural outcomes following MI. Additionally, this review also provides a complete outlook on the tissue-engineering therapies presently being used for myocardial regeneration, as well as some perceptivity into the possible issues that may hinder its progress in the future. PMID:23271906

  19. An adjunctive preventive treatment for heart disease and a set of diagnostic tests to detect it: insulin-like growth factor-1 deficiency and cell membrane pathology are an inevitable cause of heart disease.

    PubMed

    Eli, Robert; Fasciano, James A

    2006-01-01

    Coronary heart disease (CHD) is a preventable disease with high morbidity and mortality. Largely omitted from the efforts at detection and treatment are the contributions of the lungs, the skeletal muscles and the arteries to heart disease pathology. Also omitted are the effects of the age-related decline in insulin-like growth factor-1 (IGF-1) and the age-related increase in cell membrane pathology. The hypothesis on which this model is based postulates that growing older, over time, necessarily results in pathological changes in the heart, the lungs, the skeletal muscles and the arteries. Additionally, the age-related decline in (IGF-1) that occurs in the otherwise healthy aged population also causes similar pathological changes. The drug portion of the proposed treatment includes the use of the drug acetyl-l-carnitine (ALC) to increase the age-related decreased IGF-1 levels. The drug centrophenoxine (CPH) is used to reverse the age-related pathological changes that inevitably occur in the heart, the lungs, the skeletal muscles and the arteries. A testing procedure is included to improve the detection of heart disease and to monitor the results. It consists of five tests: the monitoring of plasma IGF-1 levels; the monitoring of blood pressure, and in particular elevated systolic blood pressure; the monitoring of blood pressure variability over time; a heart rate recovery time test and a heart rate reserve test. Heart rate reserve is defined as the difference between maximal heart rate and resting heart rate, after treadmill exercise. The changes in test results noted during treatment are an indicator of progress or deterioration in the prevention of heart disease, whatever the case may be.

  20. Novel cell lines promote the discovery of genes involved in early heart development.

    PubMed

    Brunskill, E W; Witte, D P; Yutzey, K E; Potter, S S

    2001-07-15

    Clonal cell lines representing early cardiomyocytes would provide valuable reagents for the dissection of the genetic program of early cardiogenesis. Here we describe the establishment and characterization of cell lines from the hearts of transgenic mice and embryos with SV40 large T antigen expressed in the heart-forming region. Ultrastructure analysis by transmission electron microscopy showed the primitive, precontractile nature of the resulting cells, with the absence of myofilaments, Z lines, and intercalated disks. Immunohistochemistry, RT-PCR, Northern blots, and oligonucleotide microarrays were used to determine the expression levels of thousands of genes in the 1H and ECL-2 cell lines. The resulting gene-expression profiles showed the transcription of early cardiomyocyte genes such as Nkx2.5, GATA4, Tbx5, dHAND, cardiac troponin C, and SM22-alpha. Furthermore, many genes not previously implicated in early cardiac development were expressed. Two of these genes, Hic-5, a possible negative regulator of muscle differentiation, and the transcription enhancing factor TEF-5 were selected and shown by in situ hybridizations to be expressed in the early developing heart. The results show that the 1H and ECL-2 cell lines can be used to discover novel genes expressed in the early cardiomyocyte. PMID:11437454

  1. Functional and Electrical Integration of Induced Pluripotent Stem Cell-Derived Cardiomyocytes in a Myocardial Infarction Rat Heart.

    PubMed

    Higuchi, Takahiro; Miyagawa, Shigeru; Pearson, James T; Fukushima, Satsuki; Saito, Atsuhiro; Tsuchimochi, Hirotsugu; Sonobe, Takashi; Fujii, Yutaka; Yagi, Naoto; Astolfo, Alberto; Shirai, Mikiyasu; Sawa, Yoshiki

    2015-01-01

    In vitro expanded beating cardiac myocytes derived from induced pluripotent stem cells (iPSC-CMs) are a promising source of therapy for cardiac regeneration. Meanwhile, the cell sheet method has been shown to potentially maximize survival, functionality, and integration of the transplanted cells into the heart. It is thus hypothesized that transplanted iPSC-CMs in a cell sheet manner may contribute to functional recovery via direct mechanical effects on the myocardial infarction (MI) heart. F344/NJcl-rnu/rnu rats were left coronary artery ligated (n = 30), followed by transplantation of Dsred-labeled iPSC-CM cell sheets of murine origin over the infarct heart surface. Effects of the treatment were assessed, including in vivo molecular/cellular evaluations using a synchrotron radiation scattering technique. Ejection fraction and activation recovery interval were significantly greater from day 3 onward after iPSC-CM transplantation compared to those after sham operation. A number of transplanted iPSC-CMs were present on the heart surface expressing cardiac myosin or connexin 43 over 2 weeks, assessed by immunoconfocal microscopy, while mitochondria in the transplanted iPSC-CMs gradually showed mature structure as assessed by electron microscopy. Of note, X-ray diffraction identified 1,0 and 1,1 equatorial reflections attributable to myosin and actin-myosin lattice planes typical of organized cardiac muscle fibers within the transplanted cell sheets at 4 weeks, suggesting cyclic systolic myosin mass transfer to actin filaments in the transplanted iPSC-CMs. Transplantation of iPSC-CM cell sheets into the heart yielded functional and electrical recovery with cyclic contraction of transplanted cells in the rat MI heart, indicating that this strategy may be a promising cardiac muscle replacement therapy.

  2. 3D timelapse analysis of muscle satellite cell motility.

    PubMed

    Siegel, Ashley L; Atchison, Kevin; Fisher, Kevin E; Davis, George E; Cornelison, D D W

    2009-10-01

    Skeletal muscle repair and regeneration requires the activity of satellite cells, a population of myogenic stem cells scattered throughout the tissue and activated to proliferate and differentiate in response to myotrauma or disease. While it seems likely that satellite cells would need to navigate local muscle tissue to reach damaged areas, relatively little data on such motility exist, and most studies have been with immortalized cell lines. We find that primary satellite cells are significantly more motile than myoblast cell lines, and that adhesion to laminin promotes primary cell motility more than fourfold over other substrates. Using timelapse videomicroscopy to assess satellite cell motility on single living myofibers, we have identified a requirement for the laminin-binding integrin alpha 7 beta 1 in satellite cell motility, as well as a role for hepatocyte growth factor in promoting directional persistence. The extensive migratory behavior of satellite cells resident on muscle fibers suggests caution when determining, based on fixed specimens, whether adjacent cells are daughters from the same mother cell. We also observed more persistent long-term contact between individual satellite cells than has been previously supposed, potential cell-cell attractive and repulsive interactions, and migration between host myofibers. Based on such activity, we assayed for expression of "pathfinding" cues, and found that satellite cells express multiple guidance ligands and receptors. Together, these data suggest that satellite cell migration in vivo may be more extensive than currently thought, and could be regulated by combinations of signals, including adhesive haptotaxis, soluble factors, and guidance cues.

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

    PubMed

    Dearth, Christopher L; Goh, Qingnian; Marino, Joseph S; Cicinelli, Peter A; Torres-Palsa, Maria J; Pierre, Philippe; Worth, Randall G; Pizza, Francis X

    2013-01-01

    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.

  4. Alterations to the electrical activity of atrial muscle isolated from the rat heart, produced by exposure in vitro to amiodarone.

    PubMed

    Northover, B J

    1984-05-01

    Glass microelectrodes were used to record transmembrane electrical activity from cells located just beneath the endocardial surface of the left atrial free wall of rat hearts during superfusion and electrical stimulation in vitro at 37 degrees C. Availability of the fast sodium channel for current flow was inferred from the maximum rate of rise of membrane potential during phase O of the action potential (Vmax). Muscle exposed to polysorbate 80 (10 to 80 micrograms ml-1) showed a concentration-dependent lengthening of action potential duration (APD) but no detectable change in Vmax. Amiodarone (1 to 20 micrograms ml-1) was dissolved in physiological salt solution with the aid of polysorbate 80 (50 micrograms ml-1) and caused a concentration-dependent prolongation of APD and a decrease in Vmax, both of which were slow to develop and extremely slow to wash-out. The speed of onset of action of amiodarone varied with drug concentration and ranged from a few minutes with high concentrations to many hours with low concentrations.

  5. Cytokine Mediated Control of Muscle Stem Cell Function.

    PubMed

    Joanisse, Sophie; Parise, Gianni

    2016-01-01

    Skeletal muscle stem cells, known as satellite cells (SC), are an absolute requirement for muscle regeneration and contribute significantly to post-natal muscle growth. This stem cell population is governed by a network of transcription factors collectively referred to as the myogenic regulatory factors. These factors are responsible for the progression of a SC from the quiescent state through activation, proliferation and terminal differentiation in a process referred to as the myogenic programme. At each stage in this process, cytokines and growth factors have been shown to play a role in directing the myogenic response. The myogenic programme is complex and requires input from a host of factors that provide both stimulatory and inhibitory signals that regulate SC. Despite years of work in this field, there remains a paucity of information on the precise factors that drive the myogenic programme. In recent years, factors, such as IL-6, have been shown to be critical factors in promoting SC proliferation. In fact, a complete absence of IL-6 in skeletal muscle substantially impairs muscle SC proliferation. These observations highlight the potential importance of the inflammatory response and the cross-talk between inflammatory cells and SC in promoting muscle repair and growth. This chapter will focus on recent advances in cytokine (and some growth factors) regulation of SC. Work from cell, animal and human models will be discussed. PMID:27003395

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

    PubMed Central

    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

  7. Regulatory Networks that Direct the Development of Specialized Cell Types in the Drosophila Heart

    PubMed Central

    Lovato, TyAnna L.; Cripps, Richard M.

    2016-01-01

    The Drosophila cardiac tube was once thought to be a simple linear structure, however research over the past 15 years has revealed significant cellular and molecular complexity to this organ. Prior reviews have focused upon the gene regulatory networks responsible for the specification of the cardiac field and the activation of cardiac muscle structural genes. Here we focus upon highlighting the existence, function, and development of unique cell types within the dorsal vessel, and discuss their correspondence to analogous structures in the vertebrate heart. PMID:27695700

  8. The roles of mesenchymal stem cells (MSCs) therapy in ischemic heart diseases

    SciTech Connect

    Wang, Xiao-Jun; Li, Qing-Ping . E-mail: doc_wxj@yahoo.com.cn

    2007-07-27

    Growing cell-based myocardial therapies which could lead to successful myocardial repair attracts medical interest. Even more intriguing is the observation that MSCs appears to be a more potent material among kinds of stem cells for the transplantation, the mechanism for this benefit remains unclear. However, the therapeutic contribution of MSCs to myocardial repair can be caused by multiple factors including: direct differentiation into cardiac tissue including cardiomyocytes, smooth muscle cell, and vascular endothelial cells; secreting a variety of cytokines and growth factors that have paracrine activities; spontaneous cell fusion; and stimulating endogenous repair. In addition, MSCs possess local immunosuppressive properties, and MSCs mobilization is widely used clinically for transplantation. We will discusses the potential mechanisms of MSCs repair for ischemic heart diseases.

  9. Variation in fatty acid composition in muscle and heart tissues among species and populations of tropical fish in Lakes Victoria and Kyoga.

    PubMed

    Kwetegyeka, Justus; Mpango, George; Grahl-Nielsen, Otto

    2008-11-01

    The composition of the fatty acids in muscle and heart tissue of seven fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), marbled lungfish (Protopterus aethiopicus), African catfish (Clarias gariepinus), Lake Victoria squeaker (Synodontis victoriae), Bagrus docmas, and Tilapia zilli, from two locations in Lake Kyoga and one location in Lake Victoria was chemometrically determined. The muscle tissue was very lean, with an average of 3.4 mg total fatty acids per g tissue. The lipid level in the heart tissue was approximately five times higher than in the muscle tissue, with an average of 15.5 mg total fatty acids per g tissue. The n-3/n-6 level in the muscles was 1.7 +/- 0.7 and in the heart tissue 1.0 +/- 0.4. The muscle tissue contained an average of 46 mg cholesterol per 100 g, and the heart tissue contained about five times as much. Plasmalogens were detected in 7-8% of the amounts of total fatty acids in both muscle and heart tissue. The seven species had large differences (P < 0.05) in the fatty acid composition for both muscle and heart tissue. Within the species there were differences between fish from the populations in the three locations, although the population differences were smaller than the species differences. These differences appear to be controlled more closely by genetics/transcriptomics than by the diet. PMID:18712426

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

    PubMed

    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.

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

    PubMed Central

    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.

    2016-01-01

    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 develop and test 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 Dystrophin reading frame in myofibers, cardiomyocytes and muscle stem cells following 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. PMID:26721686

  12. Endogenous cardiac stem cells for the treatment of heart failure

    PubMed Central

    Fuentes, Tania; Kearns-Jonker, Mary

    2013-01-01

    Stem cell-based therapies hold promise for regenerating the myocardium after injury. Recent data obtained from phase I clinical trials using endogenous cardiovascular progenitors isolated directly from the heart suggest that cell-based treatment for heart patients using stem cells that reside in the heart provides significant functional benefit and an improvement in patient outcome. Methods to achieve improved engraftment and regeneration may extend this therapeutic benefit. Endogenous cardiovascular progenitors have been tested extensively in small animals to identify cells that improve cardiac function after myocardial infarction. However, the relative lack of large animal models impedes translation into clinical practice. This review will exclusively focus on the latest research pertaining to humans and large animals, including both endogenous and induced sources of cardiovascular progenitors. PMID:24426784

  13. Novel role for thioredoxin reductase-2 in mitochondrial redox adaptations to obesogenic diet and exercise in heart and skeletal muscle

    PubMed Central

    Fisher-Wellman, Kelsey H; Mattox, Taylor A; Thayne, Kathleen; Katunga, Lalage A; La Favor, Justin D; Neufer, P Darrell; Hickner, Robert C; Wingard, Christopher J; Anderson, Ethan J

    2013-01-01

    Increased fatty acid availability and oxidative stress are physiological consequences of exercise (Ex) and a high-fat, high-sugar (HFHS) diet. Despite these similarities, the global effects of Ex are beneficial, whereas HFHS diets are largely deleterious to the cardiovascular system. The reasons for this disparity are multifactorial and incompletely understood. We hypothesized that differences in redox adaptations following HFHS diet in comparison to exercise may underlie this disparity, particularly in mitochondria. Our objective in this study was to determine mechanisms by which heart and skeletal muscle (red gastrocnemius, RG) mitochondria experience differential redox adaptations to 12 weeks of HFHS diet and/or exercise training (Ex) in rats. Surprisingly, both HFHS feeding and Ex led to contrasting effects in heart and RG, in that mitochondrial H2O2 decreased in heart but increased in RG following both HFHS diet and Ex, in comparison to sedentary animals fed a control diet. These differences were determined to be due largely to increased antioxidant/anti-inflammatory enzymes in the heart following the HFHS diet, which did not occur in RG. Specifically, upregulation of mitochondrial thioredoxin reductase-2 occurred with both HFHS and Ex in the heart, but only with Ex in RG, and systematic evaluation of this enzyme revealed that it is critical for suppressing mitochondrial H2O2 during fatty acid oxidation. These findings are novel and important in that they illustrate the unique ability of the heart to adapt to oxidative stress imposed by HFHS diet, in part through upregulation of thioredoxin reductase-2. Furthermore, upregulation of thioredoxin reductase-2 plays a critical role in preserving the mitochondrial redox status in the heart and skeletal muscle with exercise. PMID:23613536

  14. Functional Overload Enhances Satellite Cell Properties in Skeletal Muscle.

    PubMed

    Fujimaki, Shin; Machida, Masanao; Wakabayashi, Tamami; Asashima, Makoto; Takemasa, Tohru; Kuwabara, Tomoko

    2016-01-01

    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.

  15. Piperine Congeners as Inhibitors of Vascular Smooth Muscle Cell Proliferation.

    PubMed

    Mair, Christina E; Liu, Rongxia; Atanasov, Atanas G; Wimmer, Laurin; Nemetz-Fiedler, Daniel; Sider, Nadine; Heiss, Elke H; Mihovilovic, Marko D; Dirsch, Verena M; Rollinger, Judith M

    2015-08-01

    Successful vascular healing after percutaneous coronary interventions is related to the inhibition of abnormal vascular smooth muscle cell proliferation and efficient re-endothelialization. In the search for vascular smooth muscle cell anti-proliferative agents from natural sources we identified piperine (1), the main pungent constituent of the fruits from Piper nigrum (black pepper). Piperine inhibited vascular smooth muscle cell proliferation with an IC50 of 21.6 µM, as quantified by a resazurin conversion assay. Investigations of ten piperamides isolated from black pepper fruits and 15 synthesized piperine derivatives resulted in the identification of three potent vascular smooth muscle cell proliferation inhibitors: the natural alkaloid pipertipine (4), and the two synthetic derivatives (2E,4E)-N,N-dibutyl-5-(3,5-dimethoxyphenyl)penta-2,4-dienamide (14) and (E)-N,N-dibutyl-3-(naphtho[2,3-d][1,3]dioxol-5-yl)acrylamide (20). They showed IC50 values of 3.38, 6.00, and 7.85 µM, respectively. Furthermore, the synthetic compound (2E,4E)-5-(4-fluorophenyl)-1-(piperidin-1-yl)penta-2,4-dien-1-one (12) was found to be cell type selective, by inhibiting vascular smooth muscle cell proliferation with an IC50 of 11.8 µM without influencing the growth of human endothelial cells. PMID:26132851

  16. Cell Death and Heart Failure in Obesity: Role of Uncoupling Proteins

    PubMed Central

    Ruiz-Ramírez, Angélica; López-Acosta, Ocarol; Barrios-Maya, Miguel Angel

    2016-01-01

    Metabolic diseases such as obesity, metabolic syndrome, and type II diabetes are often characterized by increased reactive oxygen species (ROS) generation in mitochondrial respiratory complexes, associated with fat accumulation in cardiomyocytes, skeletal muscle, and hepatocytes. Several rodents studies showed that lipid accumulation in cardiac myocytes produces lipotoxicity that causes apoptosis and leads to heart failure, a dynamic pathological process. Meanwhile, several tissues including cardiac tissue develop an adaptive mechanism against oxidative stress and lipotoxicity by overexpressing uncoupling proteins (UCPs), specific mitochondrial membrane proteins. In heart from rodent and human with obesity, UCP2 and UCP3 may protect cardiomyocytes from death and from a state progressing to heart failure by downregulating programmed cell death. UCP activation may affect cytochrome c and proapoptotic protein release from mitochondria by reducing ROS generation and apoptotic cell death. Therefore the aim of this review is to discuss recent findings regarding the role that UCPs play in cardiomyocyte survival by protecting against ROS generation and maintaining bioenergetic metabolism homeostasis to promote heart protection.

  17. Cell Death and Heart Failure in Obesity: Role of Uncoupling Proteins.

    PubMed

    Ruiz-Ramírez, Angélica; López-Acosta, Ocarol; Barrios-Maya, Miguel Angel; El-Hafidi, Mohammed

    2016-01-01

    Metabolic diseases such as obesity, metabolic syndrome, and type II diabetes are often characterized by increased reactive oxygen species (ROS) generation in mitochondrial respiratory complexes, associated with fat accumulation in cardiomyocytes, skeletal muscle, and hepatocytes. Several rodents studies showed that lipid accumulation in cardiac myocytes produces lipotoxicity that causes apoptosis and leads to heart failure, a dynamic pathological process. Meanwhile, several tissues including cardiac tissue develop an adaptive mechanism against oxidative stress and lipotoxicity by overexpressing uncoupling proteins (UCPs), specific mitochondrial membrane proteins. In heart from rodent and human with obesity, UCP2 and UCP3 may protect cardiomyocytes from death and from a state progressing to heart failure by downregulating programmed cell death. UCP activation may affect cytochrome c and proapoptotic protein release from mitochondria by reducing ROS generation and apoptotic cell death. Therefore the aim of this review is to discuss recent findings regarding the role that UCPs play in cardiomyocyte survival by protecting against ROS generation and maintaining bioenergetic metabolism homeostasis to promote heart protection. PMID:27642497

  18. Cell Death and Heart Failure in Obesity: Role of Uncoupling Proteins

    PubMed Central

    Ruiz-Ramírez, Angélica; López-Acosta, Ocarol; Barrios-Maya, Miguel Angel

    2016-01-01

    Metabolic diseases such as obesity, metabolic syndrome, and type II diabetes are often characterized by increased reactive oxygen species (ROS) generation in mitochondrial respiratory complexes, associated with fat accumulation in cardiomyocytes, skeletal muscle, and hepatocytes. Several rodents studies showed that lipid accumulation in cardiac myocytes produces lipotoxicity that causes apoptosis and leads to heart failure, a dynamic pathological process. Meanwhile, several tissues including cardiac tissue develop an adaptive mechanism against oxidative stress and lipotoxicity by overexpressing uncoupling proteins (UCPs), specific mitochondrial membrane proteins. In heart from rodent and human with obesity, UCP2 and UCP3 may protect cardiomyocytes from death and from a state progressing to heart failure by downregulating programmed cell death. UCP activation may affect cytochrome c and proapoptotic protein release from mitochondria by reducing ROS generation and apoptotic cell death. Therefore the aim of this review is to discuss recent findings regarding the role that UCPs play in cardiomyocyte survival by protecting against ROS generation and maintaining bioenergetic metabolism homeostasis to promote heart protection. PMID:27642497

  19. Cell Death and Heart Failure in Obesity: Role of Uncoupling Proteins.

    PubMed

    Ruiz-Ramírez, Angélica; López-Acosta, Ocarol; Barrios-Maya, Miguel Angel; El-Hafidi, Mohammed

    2016-01-01

    Metabolic diseases such as obesity, metabolic syndrome, and type II diabetes are often characterized by increased reactive oxygen species (ROS) generation in mitochondrial respiratory complexes, associated with fat accumulation in cardiomyocytes, skeletal muscle, and hepatocytes. Several rodents studies showed that lipid accumulation in cardiac myocytes produces lipotoxicity that causes apoptosis and leads to heart failure, a dynamic pathological process. Meanwhile, several tissues including cardiac tissue develop an adaptive mechanism against oxidative stress and lipotoxicity by overexpressing uncoupling proteins (UCPs), specific mitochondrial membrane proteins. In heart from rodent and human with obesity, UCP2 and UCP3 may protect cardiomyocytes from death and from a state progressing to heart failure by downregulating programmed cell death. UCP activation may affect cytochrome c and proapoptotic protein release from mitochondria by reducing ROS generation and apoptotic cell death. Therefore the aim of this review is to discuss recent findings regarding the role that UCPs play in cardiomyocyte survival by protecting against ROS generation and maintaining bioenergetic metabolism homeostasis to promote heart protection.

  20. Effects of carbon monoxide on cardiac muscle cells in culture

    SciTech Connect

    Nag, A.C.; Chen, K.C.; Cheng, Mei General Motors Research Laboratories, Warren, MI )

    1988-09-01

    Embryonic rat cardiac muscle cells grown in the presence of various tensions of CO (5-95%) without the presence of O{sub 2} survived and exhibited reduced cell growth, which was concentration dependent. When cardiac muscle cells were grown in the presence of a mixture of CO (10-20%) and O{sub 2} (10-20%), the growth rate of these cells was comparable to that of the control cells. Cardiac myocytes continued to beat when exposed to varying tensions of CO, except in the case of 95% CO. The cells exposed to different concentrations of CO contained fewer myofibrils of different stages of differentiation compared with the control and the culture exposed to a mixture of 20% O{sub 2} and 20% CO, with cells that contained abundant, highly differentiated myofibrils. There was no significant difference in the structural organization of mitochondria between the control and the surviving experimental cells. It is evident from the present studies that O{sub 2} is required for the optimum in vitro cellular growth of cardiac muscle. Furthermore, CO in combination with O{sub 2} at a concentration of 10 or 20% can produce optimal growth of cardiac muscle cells in culture. To determine maximum labeling index during the labeling period, cells were continuously labeled with ({sup 3}H)thymidine for 24 h before the termination of cultures.

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

    PubMed

    Ørtenblad, N; Nielsen, J

    2015-12-01

    The importance of glycogen, as a fuel during exercise, is a fundamental concept in exercise physiology. The use of electron microscopy has revealed that glycogen is not evenly distributed in skeletal muscle fibers, but rather localized in distinct pools. In this review, we present the available evidence regarding the subcellular localization of glycogen in skeletal muscle and discuss this from the perspective of skeletal muscle fiber function. The distribution of glycogen in the defined pools within the skeletal muscle varies depending on exercise intensity, fiber phenotype, training status, 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 of the muscle fiber to energy utilization.

  2. Muscle-derived stem cells isolated as non-adherent population give rise to cardiac, skeletal muscle and neural lineages

    SciTech Connect

    Arsic, Nikola; Mamaeva, Daria; Lamb, Ned J.; Fernandez, Anne

    2008-04-01

    Stem cells with the ability to differentiate in specialized cell types can be extracted from a wide array of adult tissues including skeletal muscle. Here we have analyzed a population of cells isolated from skeletal muscle on the basis of their poor adherence on uncoated or collagen-coated dishes that show multi-lineage differentiation in vitro. When analysed under proliferative conditions, these cells express stem cell surface markers Sca-1 (65%) and Bcrp-1 (80%) but also MyoD (15%), Neuronal {beta} III-tubulin (25%), GFAP (30%) or Nkx2.5 (1%). Although capable of growing as non-attached spheres for months, when given an appropriate matrix, these cells adhere giving rise to skeletal muscle, neuronal and cardiac muscle cell lineages. A similar cell population could not be isolated from either bone marrow or cardiac tissue suggesting their specificity to skeletal muscle. When injected into damaged muscle, these non-adherent muscle-derived cells are retrieved expressing Pax7, in a sublaminar position characterizing satellite cells and participate in forming new myofibers. These data show that a non-adherent stem cell population can be specifically isolated and expanded from skeletal muscle and upon attachment to a matrix spontaneously differentiate into muscle, cardiac and neuronal lineages in vitro. Although competing with resident satellite cells, these cells are shown to significantly contribute to repair of injured muscle in vivo supporting that a similar muscle-derived non-adherent cell population from human muscle may be useful in treatment of neuromuscular disorders.

  3. Spatial arrangement of the heart muscle fascicles and intramyocardial connective tissue in the Spanish fighting bull (Bos taurus).

    PubMed Central

    Sánchez-Quintana, D; Climent, V; Garcia-Martinez, V; Rojo, M; Hurlé, J M

    1994-01-01

    The spatial arrangement of the muscle fascicles and intramyocardial connective tissue was examined in the ventricles of the heart of the Spanish fighting bull (Bos taurus). In both ventricles, the muscle fascicles of the myocardium are arranged in 3 main directions, forming 3 muscle layers within the ventricular wall. The preferentially vertical arrangement of the muscle fascicles in the superficial and deep layers at the level of the fibrous aortic rings and the base of the semilunar valve leaflets suggests that these fascicles are actively involved in valvular dynamics. After controlled digestion of myocytes and elastic fibres with NaOH, a 3-dimensional arrangement of the scaffolding of connective tissue that supports the muscle fascicles and myocytes was observed. The arrangement and structure of this scaffolding may influence the order of contraction of muscle fascicles in different layers of the ventricle. In addition, differences were observed between the connective tissue scaffolding surrounding the myocytes of the 2 ventricles; these variations were correlated with the different biomechanical properties. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 8 Fig. 9 Fig. 10 PMID:8014119

  4. [The injured and the immobilized muscle cell: ultrastructural observations].

    PubMed

    Lüthi, J M; Gerber, C; Claassen, H; Hoppeler, H

    1989-06-01

    Muscle soreness is a common feature among athletes and untrained individuals who engage in unusual, especially intense eccentric exercise. Various biochemical markers as for example elevated CK demonstrate a damage of muscle cells. The most prominent structural finding is a varying degree of disruption of the contractile material up to cell degeneration. These morphological findings reach their maximum 2 or 3 days after exercise. Signs of regeneration, however, are seen even weeks after exercise. In a prospective study we investigated the structures of the quadriceps muscle in 41 patients with chronic symptomatic instability of the anterior cruciate ligament before, 9 and 26 weeks after operation using the needle biopsy technique. The immobilized muscle showed a rapid and large atrophy which markedly reduced aerobic capacity as well as maximal strength. Preoperative values weren't attained 26 weeks postoperative despite intense physiotherapeutic exercise. The control leg showed an atrophy as well, but only aerobic capacity was reduced, maximal strength remained about the same.

  5. Vinpocetine Attenuates the Osteoblastic Differentiation of Vascular Smooth Muscle Cells.

    PubMed

    Ma, Yun-Yun; Sun, Lin; Chen, Xiu-Juan; Wang, Na; Yi, Peng-Fei; Song, Min; Zhang, Bo; Wang, Yu-Zhong; Liang, Qiu-Hua

    2016-01-01

    Vascular calcification is an active process of osteoblastic differentiation of vascular smooth muscle cells; however, its definite mechanism remains unknown. Vinpocetine, a derivative of the alkaloid vincamine, has been demonstrated to inhibit the high glucose-induced proliferation of vascular smooth muscle cells; however, it remains unknown whether vinpocetine can affect the osteoblastic differentiation of vascular smooth muscle cells. We hereby investigated the effect of vinpocetine on vascular calcification using a beta-glycerophosphate-induced cell model. Our results showed that vinpocetine significantly reduced the osteoblast-like phenotypes of vascular smooth muscle cells including ALP activity, osteocalcin, collagen type I, Runx2 and BMP-2 expression as well as the formation of mineralized nodule. Vinpocetine, binding to translocation protein, induced phosphorylation of extracellular signal-related kinase and Akt and thus inhibited the translocation of nuclear factor-kappa B into the nucleus. Silencing of translocator protein significantly attenuated the inhibitory effect of vinpocetine on osteoblastic differentiation of vascular smooth muscle cells. Taken together, vinpocetine may be a promising candidate for the clinical therapy of vascular calcification. PMID:27589055

  6. Vinpocetine Attenuates the Osteoblastic Differentiation of Vascular Smooth Muscle Cells

    PubMed Central

    Chen, Xiu-Juan; Wang, Na; Yi, Peng-Fei; Song, Min; Zhang, Bo; Wang, Yu-Zhong; Liang, Qiu-Hua

    2016-01-01

    Vascular calcification is an active process of osteoblastic differentiation of vascular smooth muscle cells; however, its definite mechanism remains unknown. Vinpocetine, a derivative of the alkaloid vincamine, has been demonstrated to inhibit the high glucose-induced proliferation of vascular smooth muscle cells; however, it remains unknown whether vinpocetine can affect the osteoblastic differentiation of vascular smooth muscle cells. We hereby investigated the effect of vinpocetine on vascular calcification using a beta-glycerophosphate-induced cell model. Our results showed that vinpocetine significantly reduced the osteoblast-like phenotypes of vascular smooth muscle cells including ALP activity, osteocalcin, collagen type I, Runx2 and BMP-2 expression as well as the formation of mineralized nodule. Vinpocetine, binding to translocation protein, induced phosphorylation of extracellular signal-related kinase and Akt and thus inhibited the translocation of nuclear factor-kappa B into the nucleus. Silencing of translocator protein significantly attenuated the inhibitory effect of vinpocetine on osteoblastic differentiation of vascular smooth muscle cells. Taken together, vinpocetine may be a promising candidate for the clinical therapy of vascular calcification. PMID:27589055

  7. Stem cells: An eventual treatment option for heart diseases.

    PubMed

    Bilgimol, Joseph C; Ragupathi, Subbareddy; Vengadassalapathy, Lakshmanan; Senthil, Nathan S; Selvakumar, Kalimuthu; Ganesan, M; Manjunath, Sadananda Rao

    2015-09-26

    Stem cells are of global excitement for various diseases including heart diseases. It is worth to understand the mechanism or role of stem cells in the treatment of heart failure. Bone marrow derived stem cells are commonly practiced with an aim to improve the function of the heart. The majority of studies have been conducted with acute myocardial infarction and a few has been investigated with the use of stem cells for treating chronic or dilated cardiomyopathy. Heterogeneity in the treated group using stem cells has greatly emerged. Ever increasing demand for any alternative made is of at most priority for cardiomyopathy. Stem cells are of top priority with the current impact that has generated among physicians. However, meticulous selection of proper source is required since redundancy is clearly evident with the present survey. This review focuses on the methods adopted using stem cells for heart diseases and outcomes that are generated so far with an idea to determine the best therapeutic possibility in order to fulfill the present demand.

  8. Osteogenic cell fractions isolated from mouse tongue muscle

    PubMed Central

    HARADA, KOJI; HARADA, TOYOKO; FERDOUS, TARANNUM; TAKENAWA, TAKANORI; UEYAMA, YOSHIYA

    2015-01-01

    The use of stem cells represents a promising approach for the treatment of bone defects. However, successful treatments rely upon the availability of cells that are easily obtained and that appropriately differentiate into osteoblasts. The tongue potentially represents a source of autologous cells for such purposes. In the present study, the ability of stem cell antigen-1 (Sca-1) positive cells derived from tongue muscle to differentiate into osteoblasts was investigated. The tongue muscles were excised from Jcl-ICR mice and tongue muscle-derived Sca-1-positive cells (TDSCs) were isolated from the tongue muscle using a magnetic cell separation system with microbeads. TDSCs were cultured in plastic dishes or gelatin sponges of β-tricalcium phosphate (β-TCP) with bone differentiation-inducing medium. The expression of osteogenic markers (Runx2, osterix, alkaline phosphatase, fibronectin, osteocalcin, osteonectin and osteopontin) was investigated in cultured TDSCs by western blot analysis. The formation of mineralized matrices was examined using alizarin red S and Von Kossa staining. Bone formation was investigated in cultured TDSCs by hematoxylin-eosin staining and immunohistochemstry. In the present study, the expression of Sca-1 in mouse tongue muscle was demonstrated and TDSCs were isolated at high purity. TDSCs differentiated into cells of osteoblast lineage, as demonstrated by the upregulation of osteoblastic marker expression. The formation of mineralized matrices was confirmed by alizarin red S or Von Kossa staining in vitro. Bone formation was observed in the gelatin sponges of β-TCP, which were subsequently implanted under the skin of the backs of nude mice. These results suggested that TDSCs retain their osteogenic differentiation potential and therefore the tongue muscle may be used as a source of stem cells for bone regeneration. PMID:25684092

  9. VEGF improves survival of mesenchymal stem cells in infarcted hearts

    SciTech Connect

    Pons, Jennifer; Huang Yu; Arakawa-Hoyt, Janice; Washko, Daniel; Takagawa, Junya; Ye, Jianqin; Grossman, William; Su Hua

    2008-11-14

    Bone marrow-derived mesenchymal stem cells (MSC) are a promising source for cell-based treatment of myocardial infarction (MI), but existing strategies are restricted by low cell survival and engraftment. We examined whether vascular endothelial growth factor (VEGF) improve MSC viability in infracted hearts. We found long-term culture increased MSC-cellular stress: expressing more cell cycle inhibitors, p16{sup INK}, p21 and p19{sup ARF}. VEGF treatment reduced cellular stress, increased pro-survival factors, phosphorylated-Akt and Bcl-xL expression and cell proliferation. Co-injection of MSCs with VEGF to MI hearts increased cell engraftment and resulted in better improvement of cardiac function than that injected with MSCs or VEGF alone. In conclusion, VEGF protects MSCs from culture-induce cellular stress and improves their viability in ischemic myocardium, which results in improvements of their therapeutic effect for the treatment of MI.

  10. Satellite cell depletion prevents fiber hypertrophy in skeletal muscle.

    PubMed

    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. PMID:27531949

  11. Interaction of Vascular Smooth Muscle Cells Under Low Shear Stress

    NASA Technical Reports Server (NTRS)

    Seidel, Charles L.

    1998-01-01

    The blood vessel wall consists of three cellular layers, an outer adventitial, a middle medial and an inner intimal layer. When the blood vessel forms in the embryo it begins as a tube composed of a single cell type called endothelial cells. Over time, other cells are recruited from the surrounding tissue to form additional layers on the outer surface of the endothelial tube. The cells that are recruited are called mesenchymal cells. Mesenchymal cells are responsible for the production of connective tissue that holds the blood vessel together and for developing into vascular smooth muscle cells that are responsible for regulating the diameter of the vessel (1) and therefore, blood flow. In a fully developed blood vessel, the endothelial cells make- up the majority of cells in the intimal layer while the mesenchymal cells make-up the majority of cells in the medial and adventitial layers. Within the medial layer of a mature vessel, cells are organized into multiple circular layers of alternating bands of connective tissue and cells. The cell layer is composed of a mixture of mesenchymal cells that have not developed into smooth muscle cells and fully developed smooth muscle cells (2). The assembly and organization of complex tissues is directed in part by a signaling system composed of proteins on the cell surface called adhesion molecules. Adhesion molecules enable cells to recognize each other as well as the composition of the connective tissue in which they reside (3). It was hypothesized that the different cell types that compose the vascular wall possess different adhesion molecules that enable them to recognize each other and through this recognition system, form the complex layered organization of the vascular wall. In other words, the layered organization is an intrinsic property of the cells. If this hypothesis is correct then the different cells that make up the vessel wall, when mixed together, should organize themselves into a layered structure

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

    PubMed

    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.

  13. Human Mesenchymal Stem Cells Reendothelialize Porcine Heart Valve Scaffolds: Novel Perspectives in Heart Valve Tissue Engineering.

    PubMed

    Lanuti, Paola; Serafini, Francesco; Pierdomenico, Laura; Simeone, Pasquale; Bologna, Giuseppina; Ercolino, Eva; Di Silvestre, Sara; Guarnieri, Simone; Canosa, Carlo; Impicciatore, Gianna Gabriella; Chiarini, Stella; Magnacca, Francesco; Mariggiò, Maria Addolorata; Pandolfi, Assunta; Marchisio, Marco; Di Giammarco, Gabriele; Miscia, Sebastiano

    2015-01-01

    Heart valve diseases are usually treated by surgical intervention addressed for the replacement of the damaged valve with a biosynthetic or mechanical prosthesis. Although this approach guarantees a good quality of life for patients, it is not free from drawbacks (structural deterioration, nonstructural dysfunction, and reintervention). To overcome these limitations, the heart valve tissue engineering (HVTE) is developing new strategies to synthesize novel types of valve substitutes, by identifying efficient sources of both ideal scaffolds and cells. In particular, a natural matrix, able to interact with cellular components, appears to be a suitable solution. On the other hand, the well-known Wharton's jelly mesenchymal stem cells (WJ-MSCs) plasticity, regenerative abilities, and their immunomodulatory capacities make them highly promising for HVTE applications. In the present study, we investigated the possibility to use porcine valve matrix to regenerate in vitro the valve endothelium by WJ-MSCs differentiated along the endothelial lineage, paralleled with human umbilical vein endothelial cells (HUVECs), used as positive control. Here, we were able to successfully decellularize porcine heart valves, which were then recellularized with both differentiated-WJ-MSCs and HUVECs. Data demonstrated that both cell types were able to reconstitute a cellular monolayer. Cells were able to positively interact with the natural matrix and demonstrated the surface expression of typical endothelial markers. Altogether, these data suggest that the interaction between a biological scaffold and WJ-MSCs allows the regeneration of a morphologically well-structured endothelium, opening new perspectives in the field of HVTE.

  14. Action Potential-Evoked Calcium Release Is Impaired in Single Skeletal Muscle Fibers from Heart Failure Patients

    PubMed Central

    DiFranco, Marino; Quiñonez, Marbella; Shieh, Perry; Fonarow, Gregg C.; Cruz, Daniel; Deng, Mario C.; Vergara, Julio L.; Middlekauff, Holly R.

    2014-01-01

    Background Exercise intolerance in chronic heart failure (HF) has been attributed to abnormalities of the skeletal muscles. Muscle function depends on intact excitation-contraction coupling (ECC), but ECC studies in HF models have been inconclusive, due to deficiencies in the animal models and tools used to measure calcium (Ca2+) release, mandating investigations in skeletal muscle from HF patients. The purpose of this study was to test the hypothesis that Ca2+ release is significantly impaired in the skeletal muscle of HF patients in whom exercise capacity is severely diminished compared to age-matched healthy volunteers. Methods and Findings Using state-of-the-art electrophysiological and optical techniques in single muscle fibers from biopsies of the locomotive vastus lateralis muscle, we measured the action potential (AP)-evoked Ca2+ release in 4 HF patients and 4 age-matched healthy controls. The mean peak Ca2+ release flux in fibers obtained from HF patients (10±1.2 µM/ms) was markedly (2.6-fold) and significantly (p<0.05) smaller than in fibers from healthy volunteers (28±3.3 µM/ms). This impairment in AP-evoked Ca2+ release was ubiquitous and was not explained by differences in the excitability mechanisms since single APs were indistinguishable between HF patients and healthy volunteers. Conclusions These findings prove the feasibility of performing electrophysiological experiments in single fibers from human skeletal muscle, and offer a new approach for investigations of myopathies due to HF and other diseases. Importantly, we have demonstrated that one step in the ECC process, AP-evoked Ca2+ release, is impaired in single muscle fibers in HF patients. PMID:25310188

  15. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887.

    PubMed

    Mednieks, M I; Popova, I A; Grindeland, R E

    1991-10-01

    A frequent cellular response to organismal stress is the increase in ligand binding by beta-adrenergic receptors. The extracellular signal is amplified by intracellular increases in cyclic AMP and the ensuing activation of cyclic AMP-dependent protein kinase (cAPK). The molecular mechanisms involve the binding of cyclic AMP to regulatory (R) subunits of cAPK, thus freeing the catalytic subunit for protein phosphorylation. This study was carried out to determine the cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 mission. Photoaffinity labeling of soluble and particulate cell fractions with an [32P]-8-azido analog of cyclic AMP was followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. The results showed that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins showed some variability in tissues of individual animals, but exhibited no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. These findings indicate that the cardiac cell integrity or its protein content is not compromised under flight conditions. There is, however, what appears to be an adaptive molecular response which can be detected using microanalytical methods, indicating that a major hormone regulated mechanism may be affected during some phase of travel in space.

  16. Cyclic AMP-receptor proteins in heart muscle of rats flown on Cosmos 1887.

    PubMed

    Mednieks, M I; Popova, I A; Grindeland, R E

    1991-10-01

    A frequent cellular response to organismal stress is the increase in ligand binding by beta-adrenergic receptors. The extracellular signal is amplified by intracellular increases in cyclic AMP and the ensuing activation of cyclic AMP-dependent protein kinase (cAPK). The molecular mechanisms involve the binding of cyclic AMP to regulatory (R) subunits of cAPK, thus freeing the catalytic subunit for protein phosphorylation. This study was carried out to determine the cellular compartmentalization of the cyclic AMP-receptor proteins in heart ventricular tissue obtained from rats flown on the Cosmos 1887 mission. Photoaffinity labeling of soluble and particulate cell fractions with an [32P]-8-azido analog of cyclic AMP was followed by electrophoretic separation of the proteins and by autoradiographic identification of the labeled isoforms of cAPK R subunits. The results showed that RII in the particulate subcellular fraction was significantly decreased in heart cells from rats in the flight group when compared to controls. Protein banding patterns in both the cytoplasmic fraction and in a fraction enriched in chromatin-bound proteins showed some variability in tissues of individual animals, but exhibited no changes that could be directly attributed to flight conditions. No significant change was apparent in the distribution of RI or RII cyclic AMP binding in the soluble fractions. These findings indicate that the cardiac cell integrity or its protein content is not compromised under flight conditions. There is, however, what appears to be an adaptive molecular response which can be detected using microanalytical methods, indicating that a major hormone regulated mechanism may be affected during some phase of travel in space. PMID:1662483

  17. Respiratory muscle strength effect on linear and nonlinear heart rate variability parameters in COPD patients

    PubMed Central

    Goulart, Cássia Da Luz; Simon, Julio Cristiano; Schneiders, Paloma De Borba; San Martin, Elisabete Antunes; Cabiddu, Ramona; Borghi-Silva, Audrey; Trimer, Renata; da Silva, Andréa Lúcia Gonçalves

    2016-01-01

    Introduction Chronic obstructive pulmonary disease (COPD) is recognized as a multisystemic inflammatory disease associated with extrapulmonary comorbidities, including respiratory muscle weakness and cardiovascular and cardiac autonomic regulation disorders. We investigated whether alterations in respiratory muscle strength (RMS) would affect cardiac autonomic modulation in COPD patients. Methods This study was a cross-sectional study done in ten COPD patients affected by moderate to very severe disease. The heart rate variability (HRV) signal was recorded using a Polar cardiofrequencimeter at rest in the sitting position (10 minutes) and during a respiratory sinus arrhythmia maneuver (RSA-M; 4 minutes). Linear analysis in the time and frequency domains and nonlinear analysis were performed on the recorded signals. RMS was assessed using a digital manometer, which provided the maximum inspiratory pressure (PImax) and the maximum expiratory pressure (PEmax). Results During the RSA-M, patients presented an HRV power increase in the low-frequency band (LFnu) (46.9±23.7 vs 75.8±27.2; P=0.01) and a decrease in the high-frequency band (HFnu) (52.8±23.5 vs 24.0±27.0; P=0.01) when compared to the resting condition. Significant associations were found between RMS and HRV spectral indices: PImax and LFnu (r=−0.74; P=0.01); PImax and HFnu (r=0.74; P=0.01); PEmax and LFnu (r=−0.66; P=0.01); PEmax and HFnu (r=0.66; P=0.03); between PEmax and sample entropy (r=0.83; P<0.01) and between PEmax and approximate entropy (r=0.74; P=0.01). Using a linear regression model, we found that PImax explained 44% of LFnu behavior during the RSA-M. Conclusion COPD patients with impaired RMS presented altered cardiac autonomic control, characterized by marked sympathetic modulation and a reduced parasympathetic response; reduced HRV complexity was observed during the RSA-M. PMID:27555757

  18. Role of miRNAs in muscle stem cell biology: proliferation, differentiation and death.

    PubMed

    Crippa, Stefania; Cassano, Marco; Sampaolesi, Maurilio

    2012-01-01

    miRNAs are small non-coding RNAs that regulate post-transcriptionally gene expression by degradation or translational repression of specific target mRNAs. In the 90s, lin-4 and let-7 were firstly identified as small regulatory RNAs able to control C. elegans larval development, by specifically targeting the 3'UTR of lin-14 and lin-28, respectively. These findings have introduced a novel and wide layer of complexity in the regulation of mRNA and protein expression. Lin-4 and let-7 are now considered the founding members of an abundant class of small fine-tuned RNAs, called microRNAs (miRNAs), in viruses, green algae, plants, flies, worms, and in mammals. In humans, the estimated number of genes encoding for miRNAs is as high as 1000 and around 30% of the protein-coding genes are post-transcriptionally controlled by miRNAs. This article reviews the role of miRNAs in regulating several biological responses in muscle cells, ranging from proliferation, differentiation and adaptation to stress cues. Cardiac and skeletal muscles are powerful examples to summarize the activity of miRNAs in cell fate specification, lineage differentiation and metabolic pathways. Indeed, specific miRNAs control the number of proliferating muscle progenitors to guarantee the proper formation of the heart and muscle fibers and to assure the self-renewal of muscle progenitors during adult tissue regeneration. On the other side, several other miRNAs promote the differentiation of muscle progenitors into skeletal myofibers or into cardiomyocytes, where metabolic activity, survival and remodeling process in response to stress, injury and chronic diseases are also fine-tuned by miRNAs. PMID:22352753

  19. Oral Gingival Cell Cigarette Smoke Exposure Induces Muscle Cell Metabolic Disruption

    PubMed Central

    Baeder, Andrea C.; Napa, Kiran; Richardson, Sarah T.; Taylor, Oliver J.; Andersen, Samantha G.; Wilcox, Shalene H.; Winden, Duane R.; Reynolds, Paul R.

    2016-01-01

    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. PMID:27034671

  20. The second heart field.

    PubMed

    Kelly, Robert G

    2012-01-01

    Ten years ago, a population of cardiac progenitor cells was identified in pharyngeal mesoderm that gives rise to a major part of the amniote heart. These multipotent progenitor cells, termed the second heart field (SHF), contribute progressively to the poles of the elongating heart tube during looping morphogenesis, giving rise to myocardium, smooth muscle, and endothelial cells. Research into the mechanisms of SHF development has contributed significantly to our understanding of the properties of cardiac progenitor cells and the origins of congenital heart defects. Here recent data concerning the regulation, clinically relevant subpopulations, evolution and lineage relationships of the SHF are reviewed. Proliferation and differentiation of SHF cells are controlled by multiple intercellular signaling pathways and a transcriptional regulatory network that is beginning to be elucidated. Perturbation of SHF development results in common forms of congenital heart defects and particular progenitor cell subpopulations are highly relevant clinically, including cells giving rise to myocardium at the base of the pulmonary trunk and the interatrial septum. A SHF has recently been identified in amphibian, fish, and agnathan embryos, highlighting the important contribution of these cells to the evolution of the vertebrate heart. Finally, SHF-derived parts of the heart share a lineage relationship with craniofacial skeletal muscles revealing that these progenitor cells belong to a broad cardiocraniofacial field of pharyngeal mesoderm. Investigation of the mechanisms underlying the dynamic process of SHF deployment is likely to yield further insights into cardiac development and pathology.

  1. New insights in endothelial and smooth muscle cell communication.

    PubMed

    Conejo, Víctor Arana; De Haro, Roberto; Sosa-Melgarejo, Jorge; Méndez, José D

    2007-01-01

    Based on immunohistochemical techniques against connexins and the intercellular flux of staining molecules, it has previously been shown that electrotonic communication occurs among endothelial and vascular smooth muscle cells, this due to the presence of myoendothelial gap junctions. The aim of this study was to evaluate the density of myoendothelial contacts in the left coronary and internal mammary arteries as well as in the left saphenous vein by means of electron microscopy, the distance between both cells participating in an myoendothelial contact with a semi-automatic image analysis system and the presence of homocellular and heterocellular gap junctions between endothelial and smooth muscle cells by using the immunohistochemical technique and confocal microscopy in thoracic aorta were also analyzed. The results are that all blood vessels studied present myoendothelial contacts, while density studies show that they are more abundant in the saphenous vein. The myoendothelial contact distance is constant and in no case the cytoplasmic processes reach the plasma membrane of the partner cell toward which they are advanced. Homocellular gap junctions were found between smooth muscle cells and between endothelial cells. Heterocellular gap junctions were absent, evidencing the possibility that signaling molecules between endothelial and smooth muscle cells may be transferred through plasma membranes as was once thought and not necessarily by electrotonic communication. PMID:17383847

  2. Hemodynamic responses to small muscle mass exercise in heart failure patients with reduced ejection fraction

    PubMed Central

    Barrett-O'Keefe, Zachary; Lee, Joshua F.; Berbert, Amanda; Witman, Melissa A. H.; Nativi-Nicolau, Jose; Stehlik, Josef; Richardson, Russell S.

    2014-01-01

    To better understand the mechanisms responsible for exercise intolerance in heart failure with reduced ejection fraction (HFrEF), the present study sought to evaluate the hemodynamic responses to small muscle mass exercise in this cohort. In 25 HFrEF patients (64 ± 2 yr) and 17 healthy, age-matched control subjects (64 ± 2 yr), mean arterial pressure (MAP), cardiac output (CO), and limb blood flow were examined during graded static-intermittent handgrip (HG) and dynamic single-leg knee-extensor (KE) exercise. During HG exercise, MAP increased similarly between groups. CO increased significantly (+1.3 ± 0.3 l/min) in the control group, but it remained unchanged across workloads in HFrEF patients. At 15% maximum voluntary contraction (MVC), forearm blood flow was similar between groups, while HFrEF patients exhibited an attenuated increase at the two highest intensities compared with controls, with the greatest difference at the highest workload (352 ± 22 vs. 492 ± 48 ml/min, HFrEF vs. control, 45% MVC). During KE exercise, MAP and CO increased similarly across work rates between groups. However, HFrEF patients exhibited a diminished leg hyperemic response across all work rates, with the most substantial decrement at the highest intensity (1,842 ± 64 vs. 2,675 ± 81 ml/min; HFrEF vs. control, 15 W). Together, these findings indicate a marked attenuation in exercising limb perfusion attributable to impairments in peripheral vasodilatory capacity during both arm and leg exercise in patients with HFrEF, which likely plays a role in limiting exercise capacity in this patient population. PMID:25260608

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

    PubMed

    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.

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

    PubMed Central

    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 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. PMID:17360543

  5. Dynamics of Cell Generation and Turnover in the Human Heart.

    PubMed

    Bergmann, Olaf; Zdunek, Sofia; Felker, Anastasia; Salehpour, Mehran; Alkass, Kanar; Bernard, Samuel; Sjostrom, Staffan L; Szewczykowska, Mirosława; Jackowska, Teresa; Dos Remedios, Cris; Malm, Torsten; Andrä, Michaela; Jashari, Ramadan; Nyengaard, Jens R; Possnert, Göran; Jovinge, Stefan; Druid, Henrik; Frisén, Jonas

    2015-06-18

    The contribution of cell generation to physiological heart growth and maintenance in humans has been difficult to establish and has remained controversial. We report that the full complement of cardiomyocytes is established perinataly and remains stable over the human lifespan, whereas the numbers of both endothelial and mesenchymal cells increase substantially from birth to early adulthood. Analysis of the integration of nuclear bomb test-derived (14)C revealed a high turnover rate of endothelial cells throughout life (>15% per year) and more limited renewal of mesenchymal cells (<4% per year in adulthood). Cardiomyocyte exchange is highest in early childhood and decreases gradually throughout life to <1% per year in adulthood, with similar turnover rates in the major subdivisions of the myocardium. We provide an integrated model of cell generation and turnover in the human heart.

  6. Improved Cell Culture Method for Growing Contracting Skeletal Muscle Models

    NASA Technical Reports Server (NTRS)

    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.

  7. Overexpression of Striated Muscle Activator of Rho Signaling (STARS) Increases C2C12 Skeletal Muscle Cell Differentiation

    PubMed Central

    Wallace, Marita A.; Della Gatta, Paul A.; Ahmad Mir, Bilal; Kowalski, Greg M.; Kloehn, Joachim; McConville, Malcom J.; Russell, Aaron P.; Lamon, Séverine

    2016-01-01

    Background: Skeletal muscle growth and regeneration depend on the activation of satellite cells, which leads to myocyte proliferation, differentiation and fusion with existing muscle fibers. Skeletal muscle cell proliferation and differentiation are tightly coordinated by a continuum of molecular signaling pathways. The striated muscle activator of Rho signaling (STARS) is an actin binding protein that regulates the transcription of genes involved in muscle cell growth, structure and function via the stimulation of actin polymerization and activation of serum-response factor (SRF) signaling. STARS mediates cell proliferation in smooth and cardiac muscle models; however, whether STARS overexpression enhances cell proliferation and differentiation has not been investigated in skeletal muscle cells. Results: We demonstrate for the first time that STARS overexpression enhances differentiation but not proliferation in C2C12 mouse skeletal muscle cells. Increased differentiation was associated with an increase in the gene levels of the myogenic differentiation markers Ckm, Ckmt2 and Myh4, the differentiation factor Igf2 and the myogenic regulatory factors (MRFs) Myf5 and Myf6. Exposing C2C12 cells to CCG-1423, a pharmacological inhibitor of SRF preventing the nuclear translocation of its co-factor MRTF-A, had no effect on myotube differentiation rate, suggesting that STARS regulates differentiation via a MRTF-A independent mechanism. Conclusion: These findings position STARS as an important regulator of skeletal muscle growth and regeneration. PMID:26903873

  8. A critical role of nicotinamide phosphoribosyltransferase in human telomerase reverse transcriptase induction by resveratrol in aortic smooth muscle cells.

    PubMed

    Huang, Peixin; Riordan, Sean M; Heruth, Daniel P; Grigoryev, Dmitry N; Zhang, Li Qin; Ye, Shui Qing

    2015-05-10

    Aging is the predominant risk factor for cardiovascular diseases and contributes to a considerably more severe outcome in patients with acute myocardial infarction. Resveratrol, a polyphenol found in red wine, is a caloric restriction mimetic with potential anti-aging properties which has emerged as a beneficial nutraceutical for patients with cardiovascular disease. Although resveratrol is widely consumed as a nutritional supplement, its mechanism of action remains to be elucidated fully. Here, we report that resveratrol activates human nicotinamide phosphoribosyltransferase (NAMPT), SIRT4 and telomerase reverse transcriptase (hTERT) in human aortic smooth muscle cells. Similar observations were obtained in resveratrol treated C57BL/6J mouse heart and liver tissues. Resverotrol can also augment telomerase activity in both human pulmonary microvascular endothelial cells and A549 cells. Blocking NAMPT and SIRT4 expression prevents induction of hTERT in human aortic smooth muscle cells while overexpression of NAMPT elevates the telomerase activity induced by resveratrol in A549 cells. Together, these results identify a NAMPT-SIRT4-hTERT axis as a novel mechanism by which resveratrol may affect the anti-aging process in human aortic smooth muscle cells, mouse hearts and other cells. These findings enrich our understanding of the positive effects of resveratrol in human cardiovascular diseases.

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

    PubMed Central

    Almeida, Camila F.; Fernandes, Stephanie A.; Ribeiro Junior, Antonio F.; 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. PMID:27042182

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

    PubMed

    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.

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

    PubMed

    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.

  12. Potential benefits of cell therapy in coronary heart disease.

    PubMed

    Grimaldi, Vincenzo; Mancini, Francesco Paolo; Casamassimi, Amelia; Al-Omran, Mohammed; Zullo, Alberto; Infante, Teresa; Napoli, Claudio

    2013-11-01

    Cardiovascular disease is the leading cause of morbidity and mortality in the world. In recent years, there has been an increasing interest both in basic and clinical research regarding the field of cell therapy for coronary heart disease (CHD). Several preclinical models of CHD have suggested that regenerative properties of stem and progenitor cells might help restoring myocardial functions in the event of cardiac diseases. Here, we summarize different types of stem/progenitor cells that have been tested in experimental and clinical settings of cardiac regeneration, from embryonic stem cells to induced pluripotent stem cells. Then, we provide a comprehensive description of the most common cell delivery strategies with their major pros and cons and underline the potential of tissue engineering and injectable matrices to address the crucial issue of restoring the three-dimensional structure of the injured myocardial region. Due to the encouraging results from preclinical models, the number of clinical trials with cell therapy is continuously increasing and includes patients with CHD and congestive heart failure. Most of the already published trials have demonstrated safety and feasibility of cell therapies in these clinical conditions. Several studies have also suggested that cell therapy results in improved clinical outcomes. Numerous ongoing clinical trials utilizing this therapy for CHD will address fundamental issues concerning cell source and population utilized, as well as the use of imaging techniques to assess cell homing and survival, all factors that affect the efficacy of different cell therapy strategies.

  13. Mesenchymal Stem Cells Improve Heart Rate Variability and Baroreflex Sensitivity in Rats with Chronic Heart Failure

    PubMed Central

    de Morais, Sharon Del Bem Velloso; da Silva, Luiz Eduardo Virgilio; Lataro, Renata Maria; Silva, Carlos Alberto Aguiar; de Oliveira, Luciano Fonseca Lemos; de Carvalho, Eduardo Elias Vieira; Simões, Marcus Vinicius; da Silva Meirelles, Lindolfo; Fazan, Rubens

    2015-01-01

    Heart failure induced by myocardial infarct (MI) attenuates the heart rate variability (HRV) and baroreflex sensitivity, which are important risk factors for life-threatening cardiovascular events. Therapies with mesenchymal stem cells (MSCs) have shown promising results after MI. However, the effects of MSCs on hemodynamic (heart rate and arterial pressure) variability and baroreflex sensitivity in chronic heart failure (CHF) following MI have not been evaluated thus far. Male Wistar rats received MSCs or saline solution intravenously 1 week after ligation of the left coronary artery. Control (noninfarcted) rats were also evaluated. MI size was assessed using single-photon emission computed tomography (SPECT). The left ventricular ejection fraction (LVEF) was evaluated using radionuclide ventriculography. Four weeks after MSC injection, the animals were anesthetized and instrumented for chronic ECG recording and catheters were implanted in the femoral artery to record arterial pressure. Arterial pressure and HRVs were determined in time and frequency domain (spectral analysis) while HRV was also examined using nonlinear methods: DFA (detrended fluctuation analysis) and sample entropy. The initial MI size was the same among all infarcted rats but was reduced by MSCs. CHF rats exhibited increased myocardial interstitial collagen and sample entropy combined with the attenuation of the following cardiocirculatory parameters: DFA indices, LVEF, baroreflex sensitivity, and HRV. Nevertheless, MSCs hampered all these alterations, except the LVEF reduction. Therefore, 4 weeks after MSC therapy was applied to CHF rats, MI size and myocardial interstitial fibrosis decreased, while baroreflex sensitivity and HRV improved. PMID:26059001

  14. Megaconial muscular dystrophy caused by mitochondrial membrane homeostasis defect, new insights from skeletal and heart muscle analyses.

    PubMed

    Vanlander, Arnaud V; Muiño Mosquera, Laura; Panzer, Joseph; Deconinck, Tine; Smet, Joél; Seneca, Sara; Van Dorpe, Jo; Ferdinande, Liesbeth; Ceuterick-de Groote, Chantal; De Jonghe, Peter; Van Coster, Rudy; Baets, Jonathan

    2016-03-01

    Megaconial congenital muscular dystrophy is a disease caused by pathogenic mutations in the gene encoding choline kinase beta (CHKB). Microscopically, the disease is hallmarked by the presence of enlarged mitochondria at the periphery of skeletal muscle fibres leaving the centre devoid of mitochondria. Clinical characteristics are delayed motor development, intellectual disability and dilated cardiomyopathy in half of reported cases. This study describes a patient presenting with the cardinal clinical features, in whom a homozygous nonsense mutation (c.248_249insT; p.Arg84Profs*209) was identified in CHKB and who was treated by heart transplantation. Microscopic evaluation of skeletal and heart muscles typically showed enlarged mitochondria. Spectrophotometric evaluation in both tissues revealed a mild decrease of all OXPHOS complexes. Using BN-PAGE analysis followed by activity staining subcomplexes of complex V were detected in both tissues, indicating incomplete complex V assembly. Mitochondrial DNA content was not depleted in analysed tissues. This is the first report describing the microscopic and biochemical abnormalities in the heart from an affected patient. A likely hypothesis is that the biochemical findings are caused by an abnormal lipid profile in the inner mitochondrial membrane resulting from a defective choline kinase B activity. PMID:26855408

  15. Megaconial muscular dystrophy caused by mitochondrial membrane homeostasis defect, new insights from skeletal and heart muscle analyses.

    PubMed

    Vanlander, Arnaud V; Muiño Mosquera, Laura; Panzer, Joseph; Deconinck, Tine; Smet, Joél; Seneca, Sara; Van Dorpe, Jo; Ferdinande, Liesbeth; Ceuterick-de Groote, Chantal; De Jonghe, Peter; Van Coster, Rudy; Baets, Jonathan

    2016-03-01

    Megaconial congenital muscular dystrophy is a disease caused by pathogenic mutations in the gene encoding choline kinase beta (CHKB). Microscopically, the disease is hallmarked by the presence of enlarged mitochondria at the periphery of skeletal muscle fibres leaving the centre devoid of mitochondria. Clinical characteristics are delayed motor development, intellectual disability and dilated cardiomyopathy in half of reported cases. This study describes a patient presenting with the cardinal clinical features, in whom a homozygous nonsense mutation (c.248_249insT; p.Arg84Profs*209) was identified in CHKB and who was treated by heart transplantation. Microscopic evaluation of skeletal and heart muscles typically showed enlarged mitochondria. Spectrophotometric evaluation in both tissues revealed a mild decrease of all OXPHOS complexes. Using BN-PAGE analysis followed by activity staining subcomplexes of complex V were detected in both tissues, indicating incomplete complex V assembly. Mitochondrial DNA content was not depleted in analysed tissues. This is the first report describing the microscopic and biochemical abnormalities in the heart from an affected patient. A likely hypothesis is that the biochemical findings are caused by an abnormal lipid profile in the inner mitochondrial membrane resulting from a defective choline kinase B activity.

  16. Heart failure from heart muscle disease in childhood: a 5–10 year follow‐up study in the UK and Ireland

    PubMed Central

    Fenton, Matthew J.; Dominguez, Troy; Burch, Michael

    2016-01-01

    Abstract Aims Our original study, the first national prospective study of new‐onset heart failure from heart muscle disease in children, showed overall 1‐year survival of 82%, and event (death or transplantation)‐free survival of 66%. This study aimed to evaluate 5 + year outcomes of this important cohort. Methods and results All centres in the UK and Ireland with 1‐year event‐free survivors participated (n = 14). Anonymised data based on last hospital attendance and echocardiograms were reviewed. The investigator was blinded to outcome at the time of echo review. Of sixty‐nine 1‐year event‐free survivors, data were obtained on 64, with three lost to follow‐up and two moved abroad. There were three deaths at 2.2, 3.3 and 9.0 years after presentation and one transplant, at 5.2 years. Overall/event‐free survival was 77%/62% at 5 years and 73%/59% at 10 years, respectively. Overall and event‐free survival conditional on 1‐year survival was 94% at 5 years, and 89% at 10 years. For the 60 event‐free survivors, median (range) follow‐up duration was 9.04 (5.0–10.33) years for those still under review (n = 45), or time to discharge 5.25 (0.67–10.0) years (n = 15). Fifty‐eight were in New York Heart Association (NYHA) Class 1, and two in Class 2. Forty‐one out of sixty had normal echocardiograms at last follow‐up. Predictors of better longer‐term outcome were the same as for the original 1‐year follow‐up study, namely, younger age and higher fractional shortening measurement at presentation. Conclusions Children who survive the first year following their first presentation with significant heart failure from heart muscle disease have a good longer‐term outcome although there remains a small attrition rate. PMID:27812385

  17. Smooth Muscle Enriched Long Noncoding RNA (SMILR) Regulates Cell Proliferation

    PubMed Central

    Ballantyne, Margaret D.; Pinel, Karine; Dakin, Rachel; Vesey, Alex T.; Diver, Louise; Mackenzie, Ruth; Garcia, Raquel; Welsh, Paul; Sattar, Naveed; Hamilton, Graham; Joshi, Nikhil; Dweck, Marc R.; Miano, Joseph M.; McBride, Martin W.; Newby, David E.; McDonald, Robert A.

    2016-01-01

    Background— Phenotypic switching of vascular smooth muscle cells from a contractile to a synthetic state is implicated in diverse vascular pathologies, including atherogenesis, plaque stabilization, and neointimal hyperplasia. However, very little is known about the role of long noncoding RNA (lncRNA) during this process. Here, we investigated a role for lncRNAs in vascular smooth muscle cell biology and pathology. Methods and Results— Using RNA sequencing, we identified >300 lncRNAs whose expression was altered in human saphenous vein vascular smooth muscle cells following stimulation with interleukin-1α and platelet-derived growth factor. We focused on a novel lncRNA (Ensembl: RP11-94A24.1), which we termed smooth muscle–induced lncRNA enhances replication (SMILR). Following stimulation, SMILR expression was increased in both the nucleus and cytoplasm, and was detected in conditioned media. Furthermore, knockdown of SMILR markedly reduced cell proliferation. Mechanistically, we noted that expression of genes proximal to SMILR was also altered by interleukin-1α/platelet-derived growth factor treatment, and HAS2 expression was reduced by SMILR knockdown. In human samples, we observed increased expression of SMILR in unstable atherosclerotic plaques and detected increased levels in plasma from patients with high plasma C-reactive protein. Conclusions— These results identify SMILR as a driver of vascular smooth muscle cell proliferation and suggest that modulation of SMILR may be a novel therapeutic strategy to reduce vascular pathologies. PMID:27052414

  18. Characterization of epicardial-derived cardiac interstitial cells: differentiation and mobilization of heart fibroblast progenitors.

    PubMed

    Ruiz-Villalba, Adrián; Ziogas, Algirdas; Ehrbar, Martin; Pérez-Pomares, José M

    2013-01-01

    The non-muscular cells that populate the space found between cardiomyocyte fibers are known as 'cardiac interstitial cells' (CICs). CICs are heterogeneous in nature and include different cardiac progenitor/stem cells, cardiac fibroblasts and other cell types. Upon heart damage CICs soon respond by initiating a reparative response that transforms with time into extensive fibrosis and heart failure. Despite the biomedical relevance of CICs, controversy remains on the ontogenetic relationship existing between the different cell kinds homing at the cardiac interstitium, as well as on the molecular signals that regulate their differentiation, maturation, mutual interaction and role in adult cardiac homeostasis and disease. Our work focuses on the analysis of epicardial-derived cells, the first cell type that colonizes the cardiac interstitium. We present here a characterization and an experimental analysis of the differentiation potential and mobilization properties of a new cell line derived from mouse embryonic epicardium (EPIC). Our results indicate that these cells express some markers associated with cardiovascular stemness and retain part of the multipotent properties of embryonic epicardial derivatives, spontaneously differentiating into smooth muscle, and fibroblast/myofibroblast-like cells. Epicardium-derived cells are also shown to initiate a characteristic response to different growth factors, to display a characteristic proteolytic expression profile and to degrade biological matrices in 3D in vitro assays. Taken together, these data indicate that EPICs are relevant to the analysis of epicardial-derived CICs, and are a god model for the research on cardiac fibroblasts and the role these cells play in ventricular remodeling in both ischemic or non/ischemic myocardial disease. PMID:23349729

  19. Stem cell death and survival in heart regeneration and repair.

    PubMed

    Abdelwahid, Eltyeb; Kalvelyte, Audrone; Stulpinas, Aurimas; de Carvalho, Katherine Athayde Teixeira; Guarita-Souza, Luiz Cesar; Foldes, Gabor

    2016-03-01

    Cardiovascular diseases are major causes of mortality and morbidity. Cardiomyocyte apoptosis disrupts cardiac function and leads to cardiac decompensation and terminal heart failure. Delineating the regulatory signaling pathways that orchestrate cell survival in the heart has significant therapeutic implications. Cardiac tissue has limited capacity to regenerate and repair. Stem cell therapy is a successful approach for repairing and regenerating ischemic cardiac tissue; however, transplanted cells display very high death percentage, a problem that affects success of tissue regeneration. Stem cells display multipotency or pluripotency and undergo self-renewal, however these events are negatively influenced by upregulation of cell death machinery that induces the significant decrease in survival and differentiation signals upon cardiovascular injury. While efforts to identify cell types and molecular pathways that promote cardiac tissue regeneration have been productive, studies that focus on blocking the extensive cell death after transplantation are limited. The control of cell death includes multiple networks rather than one crucial pathway, which underlies the challenge of identifying the interaction between various cellular and biochemical components. This review is aimed at exploiting the molecular mechanisms by which stem cells resist death signals to develop into mature and healthy cardiac cells. Specifically, we focus on a number of factors that control death and survival of stem cells upon transplantation and ultimately affect cardiac regeneration. We also discuss potential survival enhancing strategies and how they could be meaningful in the design of targeted therapies that improve cardiac function.

  20. Aortic smooth muscle cell proteoglycan synthesis in relation to atherosclerosis

    SciTech Connect

    Edwards, I.J.

    1989-01-01

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

  1. Biomechanical Origins of Muscle Stem Cell Signal Transduction.

    PubMed

    Morrissey, James B; Cheng, Richard Y; Davoudi, Sadegh; Gilbert, Penney M

    2016-04-10

    Skeletal muscle, the most abundant and widespread tissue in the human body, contracts upon receiving electrochemical signals from the nervous system to support essential functions such as thermoregulation, limb movement, blinking, swallowing and breathing. Reconstruction of adult muscle tissue relies on a pool of mononucleate, resident muscle stem cells, known as "satellite cells", expressing the paired-box transcription factor Pax7 necessary for their specification during embryonic development and long-term maintenance during adult life. Satellite cells are located around the myofibres in a niche at the interface of the basal lamina and the host fibre plasma membrane (i.e., sarcolemma), at a very low frequency. Upon damage to the myofibres, quiescent satellite cells are activated and give rise to a population of transient amplifying myogenic progenitor cells, which eventually exit the cell cycle permanently and fuse to form new myofibres and regenerate the tissue. A subpopulation of satellite cells self-renew and repopulate the niche, poised to respond to future demands. Harnessing the potential of satellite cells relies on a complete understanding of the molecular mechanisms guiding their regulation in vivo. Over the past several decades, studies revealed many signal transduction pathways responsible for satellite cell fate decisions, but the niche cues driving the activation and silencing of these pathways are less clear. Here we explore the scintillating possibility that considering the dynamic changes in the biophysical properties of the skeletal muscle, namely stiffness, and the stretch and shear forces to which a myofibre can be subjected to may provide missing information necessary to gain a full understanding of satellite cell niche regulation. PMID:26004541

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

    PubMed

    Uezumi, Akiyoshi; Nakatani, Masashi; Ikemoto-Uezumi, Madoka; Yamamoto, Naoki; Morita, Mitsuhiro; Yamaguchi, Asami; Yamada, Harumoto; Kasai, Takehiro; Masuda, Satoru; Narita, Asako; Miyagoe-Suzuki, Yuko; Takeda, Shin'ichi; Fukada, So-Ichiro; Nishino, Ichizo; Tsuchida, Kunihiro

    2016-08-01

    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. PMID:27509136

  3. Outward sodium current in beating heart cells.

    PubMed

    Wellis, D P; DeFelice, L J; Mazzanti, M

    1990-01-01

    This article is a study of the fast Na current during action potentials. We have investigated the outward Na current (Mazzanti, M., and L.J. DeFelice. 1987. Biophys. J. 52:95-100) in more detail, and we have asked whether it goes through the same channels associated with the rapid depolarization phase of action potentials. We address the question by patch clamping single, spontaneously beating, embryonic chick ventricle cells, using two electrodes to record the action potential and the patch current simultaneously. The chief limitation is the capacitive current, and in this article we describe a new method to subtract it. Varying the potential and the Na concentration in the patch pipette, and fitting the corrected currents to a standard model (Ebihara, L., and E.A. Johnson. 1980. Biophys. J. 32:779-790), provides evidence that the outward current is carried by the same channels that conduct the inward current. We compare the currents in beating cells to currents in nonbeating cells using whole-cell and cell-attached patch clamp recordings. The latter tend to show more positive Na reversal potentials, with the implication that internal Na is higher in beating cells. We propose that the plateau of the action potential, which is partly due to an inward Ca current, exceeds Na action current reversal potentials, and that this driving force gives rise to an outward movement of Na ions. The existence of such a current would imply that the fast repolarization phase after the upstroke of cardiac action potentials is partly due to the Na action current.

  4. Beta-Adrenergic Receptor Expression in Muscle Cells

    NASA Technical Reports Server (NTRS)

    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.

  5. Invited review: Stem cells and muscle diseases: advances in cell therapy strategies.

    PubMed

    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.

  6. Molecular mechanisms responsible for alcohol-induced myopathy in skeletal muscle and heart.

    PubMed

    Lang, Charles H; Frost, Robert A; Summer, Andrew D; Vary, Thomas C

    2005-10-01

    Chronic alcohol abuse has the potential to modulate striated muscle physiology and function. The skeletal muscle alcoholic myopathy is characterized by muscle weakness and difficulties in gait and locomotion, while chronic alcohol consumption ultimately leads to a decrease in cardiac contractility and output. In both tissues a loss of protein mass results in part from a decreased protein synthesis that initially manifests as a defect in translational efficiency. This review focuses on recent developments in understanding the cellular and molecular mechanisms by which alcohol impairs mRNA translation in skeletal and cardiac muscle, including identification of the signaling pathways and biochemical sites negatively impacted. Defective signaling potentially results from resistance to the normal stimulating effects of anabolic hormones (insulin and insulin-like growth factor-I) and nutrients (leucine) as well as increased production of several negative regulators of muscle mass. Overall, the biochemical mechanisms contributing to the pathogenesis of loss of skeletal and cardiac muscle are reviewed.

  7. Alterations in mitochondria and sarcoplasmic reticulum from heart and skeletal muscle of horizontally casted primates

    NASA Technical Reports Server (NTRS)

    Sordahl, L. A.; Stone, H. L.

    1982-01-01

    Horizontally body-casted rhesus monkeys are used as an animal model in order to study the physiological changes known as cardiovascular deconditioning which occur during weightless conditions. No difference was found between the experimental and control animals in heart mitochondrial oxidative phosphorylation which indicates that no apparent changes occurred in the primary energy-producing system of the heart. A marked increase in cytochrome oxidase activity was observed in the casted primate heart mitochondria compared to controls, while a 25% decrease in respiratory substrate-supported calcium uptake was found in casted primate heart mitochondria compared to controls. Sacroplasmic reticulum isolated from the primate hearts revealed marked changes in calcium transport activities. It is concluded that the marked depression in cardiac sarcoplasmic reticulum functions indicates altered calcium homeostasis in the casted-primate heart which could be a factor in cardiovascular deconditioning.

  8. Mercury and selenium concentrations in skeletal muscle, liver, and regions of the heart and kidney in bearded seals from Alaska, USA.

    PubMed

    Correa, Lucero; Castellini, J Margaret; Quakenbush, Lori T; O'Hara, Todd M

    2015-10-01

    Mean concentrations of total mercury ([THg]) and selenium ([TSe]) (mass and molar-based) were determined for 5 regions of the heart and 2 regions of the kidney of bearded seals (Erignathus barbatus) harvested in Alaska, USA, in 2010 and 2011. Mean [THg] and [TSe] of bearded seal liver and skeletal muscle tissues were used for intertissular comparison. The Se:Hg molar ratios were used to investigate elemental associations and potential antioxidant protection against Hg toxicosis. Age was an important factor in [THg] and Se:Hg molar ratios in heart and kidney. Small but statistically significant differences in mean [THg] occurred among some of the 5 heart regions (p < 0.05). Mean [THg] was highest in liver, 3.057 µg/g, and lowest in heart left ventricle, 0.017 µg/g. Mean [THg] ranked: liver > kidney cortex > kidney medulla > skeletal muscle > heart left ventricle (p < 0.001). Mean [TSe] was highest in liver, 3.848 µg/g, and lowest in heart left ventricle, 0.632 µg/g. Mean [TSe] ranked: liver > kidney cortex > kidney medulla > skeletal muscle > heart left ventricle (p < 0.001). The Se:Hg molar ratios were significantly greater than 1.0 in all tissues (p < 0.001) and represented baselines for normal [TSe] under relatively low [THg]. Mean Se:Hg molar ratios ranked: heart left ventricle > kidney medulla > kidney cortex (p < 0.001).

  9. Chronic skeletal muscle ischemia preserves coronary flow in the ischemic rat heart.

    PubMed

    Varnavas, Varnavas C; Kontaras, Konstantinos; Glava, Chryssoula; Maniotis, Christos D; Koutouzis, Michael; Baltogiannis, Giannis G; Papalois, Apostolos; Kolettis, Theofilos M; Kyriakides, Zenon S

    2011-10-01

    Chronic skeletal muscle ischemia confers cytoprotection to the ventricular myocardium during infarction, but the underlying mechanisms remain unclear. Although neovascularization in the left ventricular myocardium has been proposed as a possible mechanism, the functional capacity of such vessels has not been studied. We examined the effects of chronic limb ischemia on infarct size, coronary blood flow, and left ventricular function after ischemia-reperfusion. Hindlimb ischemia was induced in 65 Wistar rats by excision of the left femoral artery, whereas 65 rats were sham operated. After 4 wk, myocardial infarction was generated by permanent coronary artery ligation. Infarct size was measured 24 h postligation. Left ventricular function was evaluated in isolated hearts after ischemia-reperfusion, 4 wk after limb ischemia. Neovascularization was assessed by immunohistochemistry, and coronary flow was measured under maximum vasodilatation at different perfusion pressures before and after coronary ligation. Infarct size was smaller after limb ischemia compared with controls (24.4 ± 8.1% vs. 46.2 ± 9.5% of the ventricle and 47.6 ± 8.7% vs. 80.1 ± 9.3% of the ischemic area, respectively). Indexes of left ventricular function at the end of reperfusion (divided by baseline values) were improved after limb ischemia (developed pressure: 0.68 ± 0.06 vs. 0.59 ± 0.05, P = 0.008; maximum +dP/dt: 0.70 ± 0.08 vs. 0.59 ± 0.04, P = 0.004; and maximum -dP/dt: 0.86 ± 0.14 vs. 0.72 ± 0.10, P = 0.041). Coronary vessel density was markedly higher (P = 0.00021) in limb ischemic rats. In contrast to controls (F = 5.65, P = 0.00182), where coronary flow decreased, it remained unchanged (F = 1.36, P = 0.28) after ligation in limb ischemic rats. In conclusion, chronic hindlimb ischemia decreases infarct size and attenuates left ventricular dysfunction by increasing coronary collateral vessel density and blood flow.

  10. The effects of dietary fish oil on exercising skeletal muscle vascular and metabolic control in chronic heart failure rats.

    PubMed

    Holdsworth, Clark T; Copp, Steven W; Hirai, Daniel M; Ferguson, Scott K; Sims, Gabrielle E; Hageman, Karen S; Stebbins, Charles L; Poole, David C; Musch, Timothy I

    2014-03-01

    Impaired vasomotor control in chronic heart failure (CHF) is due partly to decrements in nitric oxide synthase (NOS) mediated vasodilation. Exercising muscle blood flow (BF) is augmented with polyunsaturated fatty acid (PUFA) supplementation via fish oil (FO) in healthy rats. We hypothesized that FO would augment exercising muscle BF in CHF rats via increased NO-bioavailability. Myocardial infarction (coronary artery ligation) induced CHF in Sprague-Dawley rats which were subsequently randomized to dietary FO (20% docosahexaenoic acid, 30% eicosapentaenoic acid, n = 15) or safflower oil (SO, 5%, n = 10) for 6-8 weeks. Mean arterial pressure (MAP), blood [lactate], and hindlimb muscles BF (radiolabeled microspheres) were determined at rest, during treadmill exercise (20 m·min(-1), 5% incline) and exercise + N(G)-nitro-l-arginine-methyl-ester (l-NAME) (a nonspecific NOS inhibitor). FO did not change left ventricular end-diastolic pressure (SO: 14 ± 2; FO: 11 ± 1 mm Hg, p > 0.05). During exercise, MAP (SO: 128 ± 3; FO: 132 ± 3 mm Hg) and blood [lactate] (SO: 3.8 ± 0.4; FO: 4.6 ± 0.5 mmol·L(-1)) were not different (p > 0.05). Exercising hindlimb muscle BF was lower in FO than SO (SO: 120 ± 11; FO: 93 ± 4 mL·min(-1)·100 g(-1), p < 0.05) but was not differentially affected by l-NAME. Specifically, 17 of 28 individual muscle BF's were lower (p < 0.05) in FO demonstrating that PUFA supplementation with FO in CHF rats does not augment muscle BF during exercise but may lower metabolic cost.

  11. Noninvasive Tracking of Quiescent and Activated Muscle Stem Cell (MuSC) Engraftment Dynamics In Vivo.

    PubMed

    Ho, Andrew T V; Blau, Helen M

    2016-01-01

    Muscle stem cells play a central role in muscle regeneration. Most studies in the field of muscle regeneration focus on the unraveling of muscle stem cell biology to devise strategies for treating failing muscles as seen in aging and muscle-related diseases. However, the common method used in assessing stem cell function in vivo is laborious, as it involves time-consuming immunohistological analyses by microscopy on serial cryo-sections of the muscle post stem cell transplantation. Here we describe an alternative method, which adapts the bioluminescence imaging (BLI) technique to allow noninvasive tracking of engrafted stem-cell function in vivo in real-time. This assay system enables longitudinal studies in the same mice over time and reveals parameters, not feasible by traditional analysis, such as the magnitude and dynamics of engrafted muscle stem cell expansion in vivo in response to a particular drug treatment or muscle injury. PMID:27492173

  12. Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists.

    PubMed

    van der Zwaard, Stephan; de Ruiter, Jo C; Noordhof, Dionne A; Sterrenburg, Renske; Bloemers, Frank W; de Koning, Jos J; Jaspers, Richard T; van der Laarse, Willem J

    2016-09-01

    V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondria's ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria. PMID:27445298

  13. Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction.

    PubMed

    Ranjbar, Kamal; Rahmani-Nia, Farhad; Shahabpour, Elham

    2016-09-01

    Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats.

  14. Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists.

    PubMed

    van der Zwaard, Stephan; de Ruiter, C Jo; Noordhof, Dionne A; Sterrenburg, Renske; Bloemers, Frank W; de Koning, Jos J; Jaspers, Richard T; van der Laarse, Willem J

    2016-09-01

    V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondria's ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria.

  15. Seasonal variation in pectoralis muscle and heart myostatin and tolloid-like proteinases in small birds: a regulatory role for seasonal phenotypic flexibility?

    PubMed

    Swanson, David L; King, Marisa O; Harmon, Erin

    2014-02-01

    Seasonally variable environments produce seasonal phenotypes in small birds such that winter birds have higher thermogenic capacities and pectoralis and heart masses. One potential regulator of these seasonal phenotypes is myostatin, a muscle growth inhibitor, which may be downregulated under conditions promoting increased energy demand. We examined summer-to-winter variation in skeletal muscle and heart masses and used qPCR and Western blots to measure levels of myostatin and its metalloproteinase activators TLL-1 and TLL-2 for two small temperate-zone resident birds, American goldfinches (Spinus tristis) and black-capped chickadees (Poecile atricapillus). Winter pectoralis and heart masses were significantly greater than in summer for American goldfinches. Neither myostatin expression nor protein levels differed significantly between seasons for goldfinch pectoralis. However, myostatin levels in goldfinch heart were significantly greater in summer than in winter, although heart myostatin expression was seasonally stable. In addition, expression of both metalloproteinase activators was greater in summer than in winter goldfinches for both pectoralis and heart, significantly so except for heart TLL-2 (P = 0.083). Black-capped chickadees showed no significant seasonal variation in muscle or heart masses. Seasonal patterns of pectoralis and heart expression and/or protein levels for myostatin and its metalloproteinase activators in chickadees showed no consistent seasonal trends, which may help explain the absence of significant seasonal variation in muscle or heart masses for chickadees in this study. These data are partially consistent with a regulatory role for myostatin, and especially myostatin processing capacity, in mediating seasonal metabolic phenotypes of small birds. PMID:24395519

  16. Intracellular Renin Disrupts Chemical Communication between Heart Cells. Pathophysiological Implications

    PubMed Central

    De Mello, Walmor C.

    2015-01-01

    Highlights Intracellular renin disrupts chemical communication in the heartAngiotensinogen enhances the effect of reninIntracellular enalaprilat reduces significantly the effect of reninIntracellular renin increases the inward calcium currentHarmful versus beneficial effect during myocardial infarction The influence of intracellular renin on the process of chemical communication between cardiac cells was investigated in cell pairs isolated from the left ventricle of adult Wistar Kyoto rats. The enzyme together with Lucifer yellow CH was dialyzed into one cell of the pair using the whole cell clamp technique. The diffusion of the dye in the dialyzed and in non-dialyzed cell was followed by measuring the intensity of fluorescence in both cells as a function of time. The results indicated that; (1) under normal conditions, Lucifer Yellow flows from cell to cell through gap junctions; (2) the intracellular dialysis of renin (100 nM) disrupts chemical communication – an effect enhanced by simultaneous administration of angiotensinogen (100 nM); (3) enalaprilat (10−9 M) administered to the cytosol together with renin reduced drastically the uncoupling action of the enzyme; (4) aliskiren (10−8 M) inhibited the effect of renin on chemical communication; (5) the possible role of intracellular renin independently of angiotensin II (Ang II) was evaluated including the increase of the inward calcium current elicited by the enzyme and the possible role of oxidative stress on the disruption of cell communication; (6) the possible harmful versus the beneficial effect of intracellular renin during myocardial infarction was discussed; (7) the present results indicate that intracellular renin due to internalization or in situ synthesis causes a severe impairment of chemical communication in the heart resulting in derangement of metabolic cooperation with serious consequences for heart function. PMID:25657639

  17. Resident cardiac progenitor cells: at the heart of regeneration.

    PubMed

    Bollini, Sveva; Smart, Nicola; Riley, Paul R

    2011-02-01

    Stem cell therapy has recently emerged as an innovative strategy over conventional cardiovascular treatments to restore cardiac function in patients affected by ischemic heart disease. Various stem cell populations have been tested and their potential for cardiac repair has been analyzed. Embryonic stem cells retain the greatest differentiation potential, but concerns persist with regard to their immunogenic and teratogenic effects. Although adult somatic stem cells are not tumourigenic and easier to use in an autologous setting, they exist in small numbers and possess reduced differentiation potential. Traditionally the heart was considered to be a post-mitotic organ; however, this dogma has recently been challenged with the identification of a reservoir of resident stem cells, defined as cardiac progenitor cells (CPCs). These endogenous progenitors may represent the best candidates for cardiovascular cell therapy, as they are tissue-specific, often pre-committed to a cardiac fate, and display a greater propensity to differentiate towards cardiovascular lineages. This review will focus on current research into the biology of CPCs and their regenerative potential. This article is part of a special issue entitled, "Cardiovascular Stem Cells Revisited".

  18. Intracerebral transplants of primary muscle cells: a potential 'platform' for transgene expression in the brain

    NASA Technical Reports Server (NTRS)

    Jiao, S.; Schultz, E.; Wolff, J. A.

    1992-01-01

    After the transplantation of rat primary muscle cells into the caudate or cortex of recipient rats, the muscle cells were able to persist for at least 6 months. Muscle cells transfected with expression plasmids prior to transplantation were able to express reporter genes in the brains for at least 2 months. These results suggest that muscle cells might be a useful 'platform' for transgene expression in the brain.

  19. Motilin receptors on isolated gastric smooth muscle cells.

    PubMed

    Louie, D S; Owyang, C

    1988-02-01

    Motilin has a stimulating effect on gastrointestinal motility. The mechanism of its action is not known. Direct and neuronal effects have been postulated. To determine if receptors are present on smooth muscle cells we investigated the effect of synthetic porcine motilin and its interaction with acetylcholine on isolated guinea pig gastric smooth muscle cells. Motilin elicited a dose-dependent contraction of gastric smooth muscle cells. Minimal (8.3 +/- 1.3%) and maximal (33.9 +/- 2.4%) responses were observed at 10(-12) and 10(-6) M, respectively. The ED50 of motilin was 10(-9) M. Acetylcholine also elicited a dose-response muscle contraction with a maximal response observed at 10(-7) M. Atropine (10(-7) M) completely inhibited the maximal response to acetylcholine but did not have any effect on the contractile response to motilin. In addition, dibutyryl guanosine 3',5'-cyclic monophosphate (10(-3) M) and substance P antagonist, spantide (10(-4) M), also did not inhibit the action of motilin. Acetylcholine (10(-11) M) shifted the dose-response curve of motilin to the left by 1.5 log units. The maximal response to the combination of motilin (10(-6) M) and acetylcholine (10(-11) M) was 32 +/- 3.2%, which was similar to the maximal response to motilin alone. It is concluded that distinct motilin and muscarinic receptors are present on guinea pig gastric smooth muscle cells. The interaction between motilin and acetylcholine is additive and not potentiative.

  20. Receptor Expression in Rat Skeletal Muscle Cell Cultures

    NASA Technical Reports Server (NTRS)

    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.

  1. The establishment of regular beating in populations of pacemaker heart cells. A study with tissue-cultured rat heart cells.

    PubMed

    Jongsma, H J; Tsjernina, L; de Bruijne, J

    1983-02-01

    Single isolated neonatal rat heart cells beat slowly (mean beating interval duration in the range of seconds) and irregularly (coefficient of variation greater than 40%). It is shown that slowness and irregularity of beating are intrinsic properties of the cells and are not caused by dissociation damage or lack of conditioning factors in the culture medium. When cell contacts are established either by letting the cultures grow for given amounts of time or by plating cells at increasing densities both interval duration and irregularity decrease. The beating regularity of small groups of interconnected cells (3 to 35 cells) and larger groups (200 to 15000 cells) is comparable. There is no clear cut proportionality between number of interconnected cells and beating regularity. Confluent monolayers beat fast (mean interval duration ranging between 200 and 400 ms and regular (coefficient of variation less than 5%). The hypothesis is discussed that this clock-like behavior of monolayers of heart cells is caused by the interaction of several pacemaker centers which are by themselves less regular and beat more slowly. PMID:6854658

  2. Characterization of an Injury Induced Population of Muscle-Derived Stem Cell-Like Cells

    PubMed Central

    Vojnits, Kinga; Pan, HaiYing; Mu, Xiaodong; Li, Yong

    2015-01-01

    We recently discovered a novel population of stem cells from the injured murine skeletal muscle. These injury induced muscle-derived stem cell-like cells (iMuSCs) are partially reprogrammed from differentiated myogenic cells and display a pluripotent-like state. The iMuSCs exhibit stem cell properties including the ability to differentiate into multiple lineages, such as neurogenic and myogenic differentiations; they also display a superior migration capacity that demonstrating a strong ability of muscle engraftment in vivo. IMuSCs express several pluripotent and myogenic stem cell markers; have the capability to form embryoid bodies and teratomas, and can differentiate into all three germ layers. Moreover, blastocyst microinjection showed that the iMuSCs contributed to chimeric embryos but could not complete germline transmission. Our results indicate that the iMuSCs are in a partially reprogrammed state of pluripotency, which are generated by the microenvironment of injured skeletal muscle. PMID:26611864

  3. Isolating Primary Melanocyte-like Cells from the Mouse Heart

    PubMed Central

    Hwang, Hayoung; Liu, Fang; Levin, Mark D.; Patel, Vickas V.

    2014-01-01

    We identified a novel population of melanocyte-like cells (also known as cardiac melanocytes) in the hearts of mice and humans that contribute to atrial arrhythmia triggers in mice. To investigate the electrical and biological properties of cardiac melanocytes we developed a procedure to isolate them from mouse hearts that we derived from those designed to isolate neonatal murine cardiomyocytes. In order to obtain healthier cardiac melanocytes suitable for more extensive patch clamp or biochemical studies, we developed a refined procedure for isolating and plating cardiac melanocytes based on those originally designed to isolate cutaneous melanocytes. The refined procedure is demonstrated in this review and produces larger numbers of healthy melanocyte-like cells that can be plated as a pure population or with cardiomyocytes. PMID:25285608

  4. Isolating primary melanocyte-like cells from the mouse heart.

    PubMed

    Hwang, Hayoung; Liu, Fang; Levin, Mark D; Patel, Vickas V

    2014-09-29

    We identified a novel population of melanocyte-like cells (also known as cardiac melanocytes) in the hearts of mice and humans that contribute to atrial arrhythmia triggers in mice. To investigate the electrical and biological properties of cardiac melanocytes we developed a procedure to isolate them from mouse hearts that we derived from those designed to isolate neonatal murine cardiomyocytes. In order to obtain healthier cardiac melanocytes suitable for more extensive patch clamp or biochemical studies, we developed a refined procedure for isolating and plating cardiac melanocytes based on those originally designed to isolate cutaneous melanocytes. The refined procedure is demonstrated in this review and produces larger numbers of healthy melanocyte-like cells that can be plated as a pure population or with cardiomyocytes.

  5. Vascular calcification: Mechanisms of vascular smooth muscle cell calcification.

    PubMed

    Leopold, Jane A

    2015-05-01

    Vascular calcification is highly prevalent and, when present, is associated with major adverse cardiovascular events. Vascular smooth muscle cells play an integral role in mediating vessel calcification by undergoing differentiation to osteoblast-like cells and generating matrix vesicles that serve as a nidus for calcium-phosphate deposition in the vessel wall. Once believed to be a passive process, it is now recognized that vascular calcification is a complex and highly regulated process that involves activation of cellular signaling pathways, circulating inhibitors of calcification, genetic factors, and hormones. This review will examine several of the key mechanisms linking vascular smooth muscle cells to vessel calcification that may be targeted to reduce vessel wall mineralization and, thereby, reduce cardiovascular risk.

  6. Gene transfer by adenovirus in smooth muscle cells.

    PubMed

    Yu, M F; Ewaskiewicz, J I; Adda, S; Bailey, K; Harris, V; Sosnoski, D; Tomasic, M; Wilson, J; Kotlikoff, M I

    1996-08-01

    We report adenovirus-mediated gene transfer into airway smooth muscle cells in cultured cells and organ-cultured tracheal segments. Incubation of cultured rat tracheal myocytes with virus (5 x 10(8) pfu/ml) for 6 h resulted in beta-galactosidase expression in 94.8 +/- 2.5% of cells (n = 4). Following incubation of thin (less than 200 microns diameter) equine trachealis muscle segments with virus in organ culture (5 x 10(8)-5 x 10(10) pfu/ml) the average expression of the Lac Z gene was approximately 19 +/- 10% (n = 9). Expression was markedly improved, however, in segments from neonatal rats (13-21 days). In two experiments in which the mucosa and serosa were removed, nearly all cells expressed beta-galactosidase, whereas in a third experiment in which the tissue was not dissected, about 40% of cells were stained. Viral infection had no effect on tension development of strips following organ culture. In vitro gene transfer may provide a useful method to alter protein expression and examine the effect of this alteration on excitation/contraction coupling in smooth muscle.

  7. Superparamagnetic iron oxide nanoparticles regulate smooth muscle cell phenotype

    PubMed Central

    Angelopoulos, Ioannis; Southern, Paul; Pankhurst, Quentin A.

    2016-01-01

    Abstract Superparamagnetic iron oxide nanoparticles (SPION) are used for an increasing range of biomedical applications, from imaging to mechanical actuation of cells and tissue. The aim of this study was to investigate the loading of smooth muscle cells (SMC) with SPION and to explore what effect this has on the phenotype of the cells. Adherent human SMC were loaded with ∼17 pg of unconjugated, negatively charged, 50 nm SPION. Clusters of the internalized SPION particles were held in discrete cytoplasmic vesicles. Internalized SPION did not cause any change in cell morphology, proliferation, metabolic activity, or staining pattern of actin and calponin, two of the muscle contractile proteins involved in force generation. However, internalized SPION inhibited the increased gene expression of actin and calponin normally observed when cells are incubated under differentiation conditions. The observed change in the control of gene expression of muscle contractile apparatus by SPION has not previously been described. This finding could offer novel approaches for regulating the phenotype of SMC and warrants further investigation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2412–2419, 2016. PMID:27176658

  8. Transdifferentiation of human endothelial progenitors into smooth muscle cells.

    PubMed

    Ji, HaYeun; Atchison, Leigh; Chen, Zaozao; Chakraborty, Syandan; Jung, Youngmee; Truskey, George A; Christoforou, Nicolas; Leong, Kam W

    2016-04-01

    Access to smooth muscle cells (SMC) would create opportunities for tissue engineering, drug testing, and disease modeling. Herein we report the direct conversion of human endothelial progenitor cells (EPC) to induced smooth muscle cells (iSMC) by induced expression of MYOCD. The EPC undergo a cytoskeletal rearrangement resembling that of mesenchymal cells within 3 days post initiation of MYOCD expression. By day 7, the reprogrammed cells show upregulation of smooth muscle markers ACTA2, MYH11, and TAGLN by qRT-PCR and ACTA2 and MYH11 expression by immunofluorescence. By two weeks, they resemble umbilical artery SMC in microarray gene expression analysis. The iSMC, in contrast to EPC control, show calcium transients in response to phenylephrine stimulation and a contractility an order of magnitude higher than that of EPC as determined by traction force microscopy. Tissue-engineered blood vessels constructed using iSMC show functionality with respect to flow- and drug-mediated vasodilation and vasoconstriction. PMID:26874281

  9. Phenotypic flexibility of skeletal muscle and heart masses and expression of myostatin and tolloid-like proteinases in migrating passerine birds.

    PubMed

    King, Marisa O; Zhang, Yufeng; Carter, Travis; Johnson, Jake; Harmon, Erin; Swanson, David L

    2015-04-01

    Migrant birds require large flight muscles and hearts to enhance aerobic capacity and support sustained flight. A potential mechanism for increasing muscle and heart masses during migration in birds is the muscle growth inhibitor myostatin and its metalloproteinase activators, tolloid-like proteinases (TLL-1 and TLL-2). We hypothesized that myostatin, TLL-1 and TLL-2 are downregulated during migration in pectoralis and hearts of migratory passerines to promote hypertrophy. We measured seasonal variation of tissue masses, mRNA expression of myostatin, TLL-1, and TLL-2, and myostatin protein levels in pectoralis muscle and heart for yellow warblers (Setophaga petechia), warbling vireos (Vireo gilvus), and yellow-rumped warblers (Setophaga coronata). Pectoralis mass was greatest in spring for warbling vireos and yellow warblers, but was stable between spring and fall for yellow-rumped warblers. Heart mass was higher in spring than in fall for yellow-rumped warblers, lowest in fall for warbling vireos, and seasonally stable for yellow warblers. Pectoralis and heart mRNA expression of myostatin and the TLLs did not differ significantly for any of the three species, offering little support for our hypothesis for a prominent role for myostatin in regulating migration-induced variation in pectoralis and heart masses. In contrast, pectoralis myostatin protein levels were lowest in spring for all three species, consistent with our hypothesis. Myostatin protein levels in heart, however, were seasonally stable for warbling vireos and yellow warblers, and increased in spring relative to fall for yellow-rumped warblers. These data offer mixed support for our hypothesis for the pectoralis, but suggest that myostatin is not a prominent regulator of migration-induced heart hypertrophy. Moreover, the different seasonal patterns for pectoralis mRNA and protein expression suggest that post-transcriptional modification of myostatin may contribute to pectoralis mass regulation during

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Silver nanoparticles administered to chicken affect VEGFA and FGF2 gene expression in breast muscle and heart

    NASA Astrophysics Data System (ADS)

    Hotowy, Anna; Sawosz, Ewa; Pineda, Lane; Sawosz, Filip; Grodzik, Marta; Chwalibog, André

    2012-07-01

    Nanoparticles of colloidal silver (AgNano) can influence gene expression. Concerning trials of AgNano application in poultry nutrition, it is useful to reveal whether they affect the expression of genes crucial for bird development. AgNano were administered to broiler chickens as a water solution in two concentrations (10 and 20 ppm). After dissection of the birds, breast muscles and hearts were collected. Gene expression of FGF2 and VEGFA on the mRNA and protein levels were evaluated using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay methods. The results for gene expression in the breast muscle revealed changes on the mRNA level ( FGF2 was up-regulated, P < 0.05) but not on the protein level. In the heart, 20 ppm of silver nanoparticles in drinking water increased the expression of VEGFA ( P < 0.05), at the same time decreasing FGF2 expression both on the transcriptional and translational levels. Changes in the expression of these genes may lead to histological changes, but this needs to be proven using histological and immunohistochemical examination of tissues. In general, we showed that AgNano application in poultry feeding influences the expression of FGF2 and VEGFA genes on the mRNA and protein levels in growing chicken.

  12. Identification and characterization of a non-satellite cell muscle resident progenitor during postnatal development.

    PubMed

    Mitchell, Kathryn J; Pannérec, Alice; Cadot, Bruno; Parlakian, Ara; Besson, Vanessa; Gomes, Edgar R; Marazzi, Giovanna; Sassoon, David A

    2010-03-01

    Satellite cells are resident myogenic progenitors in postnatal skeletal muscle involved in muscle postnatal growth and adult regenerative capacity. Here, we identify and describe a population of muscle-resident stem cells, which are located in the interstitium, that express the cell stress mediator PW1 but do not express other markers of muscle stem cells such as Pax7. PW1(+)/Pax7(-) interstitial cells (PICs) are myogenic in vitro and efficiently contribute to skeletal muscle regeneration in vivo as well as generating satellite cells and PICs. Whereas Pax7 mutant satellite cells show robust myogenic potential, Pax7 mutant PICs are unable to participate in myogenesis and accumulate during postnatal growth. Furthermore, we found that PICs are not derived from a satellite cell lineage. Taken together, our findings uncover a new and anatomically identifiable population of muscle progenitors and define a key role for Pax7 in a non-satellite cell population during postnatal muscle growth. PMID:20118923

  13. Cell–cell junction remodeling in the heart: Possible role in cardiac conduction system function and arrhythmias?

    PubMed Central

    Mezzano, Valeria; Sheikh, Farah

    2012-01-01

    Anchoring Cell–cell junctions (desmosomes, fascia adherens) play crucial roles in maintaining mechanical integrity of cardiac muscle cells and tissue. Genetic mutations and/or loss of critical components in these macromolecular structures are increasingly being associated with arrhythmogenic cardiomyopathies; however, their specific roles have been primarily attributed to effects within the working (ventricular) cardiac muscle. Growing evidence also points to a key role for anchoring Cell–cell junction components in cardiac muscle cells of the cardiac conduction system. This is not only evidenced by the molecular and ultra-structural presence of anchoring cell junctions in specific compartments/structures of the cardiac conduction system (sinoatrial node, atrioventricular node, His-Purkinje system), but also because conduction system-related arrhythmias can be found in humans and mouse models of cardiomyopathies harboring defects and/or mutations in key anchoring Cell–cell junction proteins. These studies emphasize the clinical need to understand the molecular and cellular role(s) for anchoring Cell–cell junctions in cardiac conduction system function and arrhythmias. This review will focus on (i) experimental findings that underline an important role for anchoring Cell–cell junctions in the cardiac conduction system, (ii) insights regarding involvement of these structures in age-related cardiac remodeling of the conduction system, (iii) summarizing available genetic mouse models that can target cardiac conduction system structures and (iv) implications of these findings on future therapies for arrhythmogenic heart diseases. PMID:22227473

  14. Dynamic Heterogeneity of the Heart Valve Interstitial Cell Population in Mitral Valve Health and Disease

    PubMed Central

    Sauls, Kimberly; Koenig, Sara N.; Anstine, Lindsey J.; Garg, Vidu; Norris, Russell A.; Lincoln, Joy

    2015-01-01

    The heart valve interstitial cell (VIC) population is dynamic and thought to mediate lay down and maintenance of the tri-laminar extracellular matrix (ECM) structure within the developing and mature valve throughout life. Disturbances in the contribution and distribution of valve ECM components are detrimental to biomechanical function and associated with disease. This pathological process is associated with activation of resident VICs that in the absence of disease reside as quiescent cells. While these paradigms have been long standing, characterization of this abundant and ever-changing valve cell population is incomplete. Here we examine the expression pattern of Smooth muscle α-actin, Periostin, Twist1 and Vimentin in cultured VICs, heart valves from healthy embryonic, postnatal and adult mice, as well as mature valves from human patients and established mouse models of disease. We show that the VIC population is highly heterogeneous and phenotypes are dependent on age, species, location, and disease state. Furthermore, we identify phenotypic diversity across common models of mitral valve disease. These studies significantly contribute to characterizing the VIC population in health and disease and provide insights into the cellular dynamics that maintain valve structure in healthy adults and mediate pathologic remodeling in disease states. PMID:26527432

  15. Excitation—contraction coupling in amphioxus muscle cells

    PubMed Central

    Hagiwara, S.; Henkart, Maryanna P.; Kidokoro, Y.

    1971-01-01

    1. Excitation-contraction coupling was studied in myotomal muscles of amphioxus, Branchiostoma californiense. 2. The action potential of a muscle cell produces a twitch with a rise time of 30-40 msec at 11° C and its Q10 is about 2·2. 3. The twitch increases in amplitude with increasing external Ca concentration and is abolished in Ca-free saline (1 mM-EGTA and 55·7 mM-MgCl2); the twitch amplitude is suppressed by Co or La ions. 4. Caffeine at concentrations above 1 mM in the external saline causes a prolongation of the action potential and a contracture which lasts several minutes. 5. After exposure to caffeine the responsiveness of the muscle to subsequent applications of caffeine recovers in normal saline in 20-30 minutes but not in Ca-free saline. 6. The amplitude of the caffeine contracture is independent of the external Ca concentration and is unaltered after the twitch is eliminated in Ca-free saline. 7. After exposure to caffeine a full-sized twitch can be obtained before the responsiveness to caffeine shows any significant recovery. 8. It is concluded that the twitch is produced by the Ca influx resulting from the increased permeability of the muscle cell membrane to Ca during the action potential and that the Ca mobilized by caffeine is not necessary to the initiation of the twitch. 9. Electronmicroscopy shows the existence of sarcoplasmic reticulum. Imagesabc and dabcd PMID:5158596

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

    PubMed

    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. PMID:25734774

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

    PubMed

    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.

  18. Smooth Muscle-Like Tissue Constructs with Circumferentially Oriented Cells Formed by the Cell Fiber Technology

    PubMed Central

    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. PMID:25734774

  19. Skeletal muscle satellite cells: mediators of muscle growth during development and implications for developmental disorders.

    PubMed

    Dayanidhi, Sudarshan; Lieber, Richard L

    2014-11-01

    Satellite cells (SCs) are the muscle stem cells responsible for longitudinal and cross-sectional postnatal growth and repair after injury and which provide new myonuclei when needed. We review their morphology and contribution to development and their role in sarcomere and myonuclear addition. SCs, similar to other tissue stem cells, cycle through different states, such as quiescence, activation, and self-renewal, and thus we consider the signaling mechanisms involved in maintenance of these states. The role of the SC niche and their interactions with other cells, such as fibroblasts and the extracellular matrix, are all emerging as major factors that affect aging and disease. Interestingly, children with cerebral palsy appear to have a reduced SC number, which could play a role in their reduced muscular development and even in muscular contracture formation. Finally, we review the current information on SC dysfunction in children with muscular dystrophy and emerging therapies that target promotion of myogenesis and reduction of fibrosis.

  20. Changes in skeletal muscle biochemistry and histology relative to fiber type in rats with heart failure

    NASA Technical Reports Server (NTRS)

    Delp, M. D.; Duan, C.; Mattson, J. P.; Musch, T. I.

    1997-01-01

    One of the primary consequences of left ventricular dysfunction (LVD) after myocardial infarction is a decrement in exercise capacity. Several factors have been hypothesized to account for this decrement, including alterations in skeletal muscle metabolism and aerobic capacity. The purpose of this study was to determine whether LVD-induced alterations in skeletal muscle enzyme activities, fiber composition, and fiber size are 1) generalized in muscles or specific to muscles composed primarily of a given fiber type and 2) related to the severity of the LVD. Female Wistar rats were divided into three groups: sham-operated controls (n = 13) and rats with moderate (n = 10) and severe (n = 7) LVD. LVD was surgically induced by ligating the left main coronary artery and resulted in elevations (P < 0.05) in left ventricular end-diastolic pressure (sham, 5 +/- 1 mmHg; moderate LVD, 11 +/- 1 mmHg; severe LVD, 25 +/- 1 mmHg). Moderate LVD decreased the activities of phosphofructokinase (PFK) and citrate synthase in one muscle composed of type IIB fibers but did not modify fiber composition or size of any muscle studied. However, severe LVD diminished the activity of enzymes involved in terminal and beta-oxidation in muscles composed primarily of type I fibers, type IIA fibers, and type IIB fibers. In addition, severe LVD induced a reduction in the activity of PFK in type IIB muscle, a 10% reduction in the percentage of type IID/X fibers, and a corresponding increase in the portion of type IIB fibers. Atrophy of type I fibers, type IIA fibers, and/or type IIB fibers occurred in soleus and plantaris muscles of rats with severe LVD. These data indicate that rats with severe LVD after myocardial infarction exhibit 1) decrements in mitochondrial enzyme activities independent of muscle fiber composition, 2) a reduction in PFK activity in type IIB muscle, 3) transformation of type IID/X to type IIB fibers, and 4) atrophy of type I, IIA, and IIB fibers.

  1. The peculiar apoptotic behavior of skeletal muscle cells.

    PubMed

    Salucci, Sara; Burattini, Sabrina; Baldassarri, Valentina; Battistelli, Michela; Canonico, Barbara; Valmori, Aurelio; Papa, Stefano; Falcieri, Elisabetta

    2013-08-01

    Apoptosis plays an active role in maintaining skeletal muscle homeostasis. Its deregulation is involved in several skeletal muscle disorders such as dystrophies, myopathies, disuse and sarcopenia. The aim of this work was to study in vitro the apoptotic behavior induced by etoposide, staurosporine and hydrogen peroxide in the C2C12 skeletal muscle cell line, comparing myoblast vs myotube sensitivity, investigated by means of morphological and cytofluorimetric analyses. Myotubes appeared more resistant than myoblasts to apoptotic induction. In myoblasts treated with etoposide, nuclei with chromatin condensation were observed, in the presence of a diffuse DNA fragmentation, as shown by confocal microscopy. The latter also appeared in myotubes, where apoptotic and normal nuclei coexisted inside the same syncytium. After staurosporine treatment, myobalsts evidenced late apoptotic features and a high number of TUNEL-positive nuclei. Secondary necrosis appeared in myotubes, where myonuclei with cleaved DNA again coexisted with normal myonuclei. After H₂O₂ exposure, myotubes, differently from myoblasts, showed a poor sensitivity to cell death. Intriguingly, autophagic granules appeared abundantly in myotubes after each treatment. In myotubes, mitochondria were better preserved than in myoblasts since those which were damaged were probably degraded through autophagic processes. These findings demonstrate a scarce sensitivity of myotubes to apoptotic stimuli due to acquisition of an apoptosis-resistant phenotype during differentiation. The presence of nuclear-dependent "territorial" death domains in the syncytium could explain a slower death of myotubes compared to mononucleated cells. In addition, autophagy could preserve and protect muscle cell integrity against chemical stimuli, making C2C12 cells, in particular myotubes, more resistant to apoptosis induction. PMID:23400589

  2. Lysyl oxidase propeptide inhibits smooth muscle cell signaling and proliferation

    SciTech Connect

    Hurtado, Paola A.; Vora, Siddharth; Sume, Siddika Selva; Yang, Dan; Hilaire, Cynthia St.; Guo Ying; Palamakumbura, Amitha H.; Schreiber, Barbara M.; Ravid, Katya; Trackman, Philip C.

    2008-02-01

    Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression. In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-{alpha}-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology.

  3. Mitochondrial dynamics and cell death in heart failure.

    PubMed

    Marín-García, José; Akhmedov, Alexander T

    2016-03-01

    The highly regulated processes of mitochondrial fusion (joining), fission (division) and trafficking, collectively called mitochondrial dynamics, determine cell-type specific morphology, intracellular distribution and activity of these critical organelles. Mitochondria are critical for cardiac function, while their structural and functional abnormalities contribute to several common cardiovascular diseases, including heart failure (HF). The tightly balanced mitochondrial fusion and fission determine number, morphology and activity of these multifunctional organelles. Although the intracellular architecture of mature cardiomyocytes greatly restricts mitochondrial dynamics, this process occurs in the adult human heart. Fusion and fission modulate multiple mitochondrial functions, ranging from energy and reactive oxygen species production to Ca(2+) homeostasis and cell death, allowing the heart to respond properly to body demands. Tightly controlled balance between fusion and fission is of utmost importance in the high energy-demanding cardiomyocytes. A shift toward fission leads to mitochondrial fragmentation, while a shift toward fusion results in the formation of enlarged mitochondria and in the fusion of damaged mitochondria with healthy organelles. Mfn1, Mfn2 and OPA1 constitute the core machinery promoting mitochondrial fusion, whereas Drp1, Fis1, Mff and MiD49/51 are the core components of fission machinery. Growing evidence suggests that fusion/fission factors in adult cardiomyocytes play essential noncanonical roles in cardiac development, Ca(2+) signaling, mitochondrial quality control and cell death. Impairment of this complex circuit causes cardiomyocyte dysfunction and death contributing to heart injury culminating in HF. Pharmacological targeting of components of this intricate network may be a novel therapeutic modality for HF treatment. PMID:26872674

  4. Replication of prions in differentiated muscle cells.

    PubMed

    Herbst, Allen; Aiken, Judd M; McKenzie, Debbie

    2014-01-01

    We have demonstrated that prions accumulate to high levels in non-proliferative C2C12 myotubes. C2C12 cells replicate as myoblasts but can be differentiated into myotubes. Earlier studies indicated that C2C12 myoblasts are not competent for prion replication. (1) We confirmed that observation and demonstrated, for the first time, that while replicative myoblasts do not accumulate PrP(Sc), differentiated post-mitotic myotube cultures replicate prions robustly. Here we extend our observations and describe the implication and utility of this system for replicating prions.

  5. Semicarbazide-sensitive amine oxidase and extracellular matrix deposition by smooth-muscle cells

    NASA Technical Reports Server (NTRS)

    Langford, Shannon D.; Trent, Margaret B.; Boor, Paul J.

    2002-01-01

    We have recently reported in vivo disruption of collagen and elastin architecture within blood vessel walls resulting from the selective inhibition of the enzyme semicarbazide-sensitive amine oxidase (SSAO). This study further investigates the effects of SSAO inhibition on extracellular matrix deposition by smooth-muscle cells (SMCs) cultured from neonatal rat hearts. SMCs were characterized, SSAO activity was measured, and soluble and insoluble collagen and elastin in the extracellular matrix (ECM) were quantified. Cultured neonatal rat heart SMC exhibited a monotypic synthetic phenotype that likely represents a myofibroblast. Detectable levels of SSAO activity present throughout 30-d culture peaked at 7-14 d, coinciding with the production of ECM. The addition of enzyme inhibitors and alternate SSAO substrates (benzylamine) produced varied and, in some cases, marked changes in SSAO activity as well as in the composition of mature and soluble matrix components. Similar to our previous in vivo findings, in vitro SSAO inhibition produced aberrations in collagen and elastin deposition by heart SMC. Because changes in SSAO activity are associated with cardiovascular pathologic states, this enzyme may play a protective or modulating role by regulating ECM production during pathologic insult.

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

    PubMed

    Naldaiz-Gastesi, Neia; Goicoechea, María; Alonso-Martín, Sonia; Aiastui, Ana; López-Mayorga, Macarena; García-Belda, Paula; Lacalle, Jaione; San José, Carlos; Araúzo-Bravo, Marcos J; Trouilh, Lidwine; Anton-Leberre, Véronique; Herrero, Diego; Matheu, Ander; Bernad, Antonio; García-Verdugo, José Manuel; Carvajal, Jaime J; Relaix, Frédéric; Lopez de Munain, Adolfo; García-Parra, Patricia; Izeta, Ander

    2016-09-13

    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.

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

    SciTech Connect

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

    2011-04-15

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

  8. Gene and cell therapy for chronic ischaemic heart disease.

    PubMed

    Poh, Kian-Keong

    2007-01-01

    Viable treatment options are becoming available for the 'no-option' patient with chronic ischaemic heart disease. Instead of revascularising the highly diseased epicardial coronary arteries, scientists and clinicians have been looking at augmenting mother nature's way of providing biological bypass in an attempt to provide symptomatic relief in these patients. The novel use of gene and cell therapies for myocardial neovascularisation has exploded into a flurry of early clinical trials. This translational research has been motivated by an improved understanding of the biological mechanisms involved in tissue repair after ischaemic injury. While safety concerns will be top in priority in these trials, different types or combination of therapies, dose and route of delivery are being tested before further optimisation and establishment. With cautious optimism, a new era in the treatment of ischaemic heart disease is being entered. This article reviews the present state in gene and cell therapies for ischaemic heart disease, the modalities of their delivery, novel imaging techniques and future perspectives.

  9. Lysophosphatidic acid mediates pleiotropic responses in skeletal muscle cells

    SciTech Connect

    Jean-Baptiste, Gael; Yang Zhao; Khoury, Chamel; Greenwood, Michael T.; E-mail: michael.greenwood@mcgill.ca

    2005-10-07

    Lysophosphatidic acid (LPA) is a potent modulator of growth, cell survival, and apoptosis. Although all four LPA receptors are expressed in skeletal muscle, very little is known regarding the role they play in this tissue. We used RT-PCR to demonstrate that cultured skeletal muscle C2C12 cells endogenously express multiple LPA receptor subtypes. The demonstration that LPA mediates the activation of ERK1/2 MAP kinase and Akt/PKB in C2C12 cells is consistent with the widely observed mitogenic properties of LPA. In spite of these observations, LPA did not induce proliferation in C2C12 cells. Paradoxically, we found that prolonged treatment of C2C12 cells with LPA led to caspase 3 and PARP cleavage as well as the activation of stress-associated MAP kinases JNK and p38. In spite of these typically pro-apoptotic responses, LPA did not induce cell death. Blocking ERK1/2 and Akt/PKB activation with specific pharmacological inhibitors, nevertheless, stimulated LPA-mediated apoptosis. Taken together, these results suggest that both mitogenic and apoptotic responses serve to counterbalance the effects of LPA in cultured C2C12 cells.

  10. Microwave radiation effects on cardiac muscle cells in vitro

    SciTech Connect

    Galvin, M.J.; Hall, C.A.; McRee, D.I.

    1981-05-01

    Isolated cardiac muscle cells were exposed to microwave radiation in a temperature-controlled waveguide apparatus. Microwave radiation for 90 min at specific absorption rates (SAR) as low as 10 mW/g increases the permeability of cardiac cells to trypan blue. At 100 mW/g the inability of the cells to exclude trypan blue is concurrent with the release of lactic dehydrogenase into the suspending medium. However, when the SAR is decreased to 50 mW/g, trypan blue uptake is still elevated without the concomitant release of lactic dehydrogenase. Transmission electron micrographs of the exposed cells showed cellular damage only at the 100 mW/g exposure level. The microwave-reduced change in membrane permeability was unrelated to a macroscopic heating effect of microwave radiation on the cells, but appeared to be due to some other specific action of microwave radiation on isolated cardiac cells.

  11. A Novel Selectable Islet 1 Positive Progenitor Cell Reprogrammed to Expandable and Functional Smooth Muscle Cells.

    PubMed

    Turner, Elizabeth C; Huang, Chien-Ling; Sawhney, Neha; Govindarajan, Kalaimathi; Clover, Anthony J P; Martin, Kenneth; Browne, Tara C; Whelan, Derek; Kumar, Arun H S; Mackrill, John J; Wang, Shaohua; Schmeckpeper, Jeffrey; Stocca, Alessia; Pierce, William G; Leblond, Anne-Laure; Cai, Liquan; O'Sullivan, Donnchadh M; Buneker, Chirlei K; Choi, Janet; MacSharry, John; Ikeda, Yasuhiro; Russell, Stephen J; Caplice, Noel M

    2016-05-01

    Disorders affecting smooth muscle structure/function may require technologies that can generate large scale, differentiated and contractile smooth muscle cells (SMC) suitable for cell therapy. To date no clonal precursor population that provides large numbers of differentiated SMC in culture has been identified in a rodent. Identification of such cells may also enhance insight into progenitor cell fate decisions and the relationship between smooth muscle precursors and disease states that implicate differentiated SMC.  In this study, we used classic clonal expansion techniques to identify novel self-renewing Islet 1 (Isl-1) positive primitive progenitor cells (PPC) within rat bone marrow that exhibited canonical stem cell markers and preferential differentiation towards a smooth muscle-like fate. We subsequently used molecular tagging to select Isl-1 positive clonal populations from expanded and de novo marrow cell populations. We refer to these previously undescribed cells as the PPC given its stem cell marker profile, and robust self-renewal capacity. PPC could be directly converted into induced smooth muscle cells (iSMC) using single transcription factor (Kruppel-like factor 4) knockdown or transactivator (myocardin) overexpression in contrast to three control cells (HEK 293, endothelial cells and mesenchymal stem cells) where such induction was not possible. iSMC exhibited immuno- and cytoskeletal-phenotype, calcium signaling profile and contractile responses similar to bona fide SMC. Passaged iSMC could be expanded to a scale sufficient for large scale tissue replacement.  PPC and reprogramed iSMC so derived may offer future opportunities to investigate molecular, structure/function and cell-based replacement therapy approaches to diverse cardiovascular, respiratory, gastrointestinal, and genitourinary diseases that have as their basis smooth muscle cell functional aberrancy or numerical loss. Stem Cells 2016;34:1354-1368.

  12. Differential gene expression in skeletal muscle cells after membrane depolarization.

    PubMed

    Juretić, Nevenka; Urzúa, Ulises; Munroe, David J; Jaimovich, Enrique; Riveros, Nora

    2007-03-01

    Skeletal muscle is a highly plastic tissue with a remarkable capacity to adapt itself to challenges imposed by contractile activity. Adaptive response, that include hypertrophy and activation of oxidative mechanisms have been associated with transient changes in transcriptional activity of specific genes. To define the set of genes regulated by a depolarizing stimulus, we used 22 K mouse oligonucleotide microarrays. Total RNA from C2C12 myotubes was obtained at 2, 4, 18, and 24 h after high K+ stimulation. cDNA from control and depolarized samples was labeled with cyanine 3 or 5 dyes prior to microarray hybridization. Loess normalization followed by statistical analysis resulted in 423 differentially expressed genes using an unadjusted P-value < or = 0.01 as cut off. Depolarization affects transcriptional activity of a limited number of genes, mainly associated with metabolism, cell communication and response to stress. A number of genes related to Ca2+ signaling pathways are induced at 4 h, reinforcing the potential role of Ca2+ in early steps of signal transduction that leads to gene expression. Significant changes in the expression of molecules involved in muscle cell structure were observed; K+-depolarization increased Tnni1 and Acta1 mRNA levels in both differentiated C2C12 and rat skeletal muscle cells in primary culture. Of these two, depolarization induced slow Ca2+ transients appear to have a role only in the regulation of Tnni1 transcriptional activity. We suggest that depolarization induced expression of a small set of genes may underlie Ca2+ dependent plasticity of skeletal muscle cells. PMID:17146758

  13. Effects of calcium phosphate bioceramics on skeletal muscle cells.

    PubMed

    Sun, J S; Tsuang, Y H; Yao, C H; Liu, H C; Lin, F H; Hang, Y S

    1997-02-01

    With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes. The effects of implants on bony tissue have been investigated. The effects upon adjacent skeletal muscles have not been determined. The focus of this work is to elucidate the biological effects of various calcium phosphate bioceramics on skeletal muscles. Four different kinds of powder of calcium phosphate biomaterials including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP) and sintered beta-dicalcium pyrophosphate (SDCP), were tested by myoblast cell cultures. The results were analyzed by cell count, cell morphology and concentration of transforming growth factor beta 1 (TGF-beta 1) in culture medium. The cell population and TGF-beta 1 concentration of the control sample increased persistently as the time of culture increased. The changes in cell population and TGF-beta 1 concentration in culture medium of the beta-TCP and HA were quite low in the first 3 days of culture, then increased gradually toward the seventh day. The changes in cell population and TGF-beta 1 concentration in culture medium of the silica, beta-DCP, and SDCP were quite similar. They were lower during the first day of culture but increased and reached that of the control medium after 7 days' culture. Most cells on B-TCP and HA diminished in size with radially spread, long pseudopods. We conclude that HA and beta-TCP are thought to have an inhibitory effect on growth of the myoblasts. The HA and beta-TCP may interfere with the repair and regeneration of injured skeletal muscle after orthopedic surgery.

  14. Fluid dynamics of heart development.

    PubMed

    Santhanakrishnan, Arvind; Miller, Laura A

    2011-09-01

    The morphology, muscle mechanics, fluid dynamics, conduction properties, and molecular biology of the developing embryonic heart have received much attention in recent years due to the importance of both fluid and elastic forces in shaping the heart as well as the striking relationship between the heart's evolution and development. Although few studies have directly addressed the connection between fluid dynamics and heart development, a number of studies suggest that fluids may play a key role in morphogenic signaling. For example, fluid shear stress may trigger biochemical cascades within the endothelial cells of the developing heart that regulate chamber and valve morphogenesis. Myocardial activity generates forces on the intracardiac blood, creating pressure gradients across the cardiac wall. These pressures may also serve as epigenetic signals. In this article, the fluid dynamics of the early stages of heart development is reviewed. The relevant work in cardiac morphology, muscle mechanics, regulatory networks, and electrophysiology is also reviewed in the context of intracardial fluid dynamics. PMID:21327946

  15. Skeletal muscle grafts applied to the heart. A word of caution.

    PubMed

    Anderson, W A; Andersen, J S; Acker, M A; Hammond, R L; Chin, A J; Douglas, P S; Khalafalla, A S; Salmons, S; Stephenson, L W

    1988-11-01

    Latissimus dorsi pedicle grafts (LDPGs) were wrapped around the heart in eight dogs. In four dogs, the LDPGs were stimulated chronically; the remaining four dogs served as unstimulated controls. Right-sided cardiac filling pressures were normal in all dogs when measured 4 months after graft application. Mean tension generated by the viable LDPGs was 153 +/- 49.9 g. LDPGs contracting in synchrony with the heart did not increase cardiac output. In one dog, the aortic pressure changed from 140/100 to 155/85 mm Hg during synchronous contraction of the LDPG. Three dogs were placed on cardiopulmonary bypass, and their hearts were placed in fibrillation. The LDPGs were then stimulated at a burst frequency of 85 Hz and contracted vigorously. Under these conditions, the left ventricular pressure increased by an average of 15 mm Hg with each LDPG contraction; however, the mean aortic pressure was virtually unchanged. Left ventricular and aortic pressures of 125/20 and 125/65 mm Hg, respectively, could be obtained with manual compression of the fibrillating heart. This study indicates that although LDPGs can be made to contract chronically and in synchrony with the heart, they do not necessarily augment left ventricular performance. PMID:3180397

  16. Skeletal muscle stem cells adopt a dormant cell state post mortem and retain regenerative capacity.

    PubMed

    Latil, Mathilde; Rocheteau, Pierre; Châtre, Laurent; Sanulli, Serena; Mémet, Sylvie; Ricchetti, Miria; Tajbakhsh, Shahragim; Chrétien, Fabrice

    2012-01-01

    The accessibility to stem cells from healthy or diseased individuals, and the maintenance of their potency are challenging issues for stem cell biology. Here we report the isolation of viable and functional skeletal myogenic cells from humans up to 17 days, and mice up to 14 days post mortem, much longer beyond previous reports. Muscle stem cells are enriched in post mortem tissue, suggesting a selective survival advantage compared with other cell types. Transplantation of mouse muscle and haematopoietic stem cells regenerates tissues robustly. Cellular quiescence contributes to this cell viability where cells adopt a reversible dormant state characterized by reduced metabolic activity, a prolonged lag phase before the first cell division, elevated levels of reactive oxygen species and a transcriptional status less primed for commitment. Finally, severe hypoxia, or anoxia is critical for maintaining stem cell viability and regenerative capacity. Thus, these cells provide a useful resource for studying stem cell biology.

  17. Remote muscle salvage by regional substrate enhancement during on-bypass beating-heart treatment of cardiogenic shock.

    PubMed

    Pocar, Marco; Passolunghi, Davide; Moneta, Andrea; Donatelli, Francesco

    2011-01-01

    Surgical revascularization for postinfarction cardiogenic shock carries 20-50% mortality. Beating-heart techniques have been favoured, but their impact on the avoidance of additional myocardial injury is unknown. Ten consecutive patients with postinfarction cardiogenic shock, unsuitable anatomy for percutaneous coronary intervention (Syntax score 34.0±7.5; triple-vessel disease, 10/10; left main stenosis, 5/10), and no associated cardiac procedure, were selected for salvage/emergent on-pump beating-heart coronary bypass surgery. Remote muscle was sequentially substrate-enhanced reperfused through the grafts after construction of distal anastomoses. Early/late mortality, preoperative/peak postoperative enzyme release, and baseline/pre-discharge ventricular function were analysed. One early death occurred. Patients received 2.9±0.6 grafts, always employing the left internal mammary artery. Cardiopulmonary bypass duration was 140±62 min. Left ventricular ejection fraction (29.4±5.8 vs. 37.5±8.3%), wall motion score index (2.10±0.29 vs. 1.86±0.28), and end-systolic volume index (42.1±11.5 vs. 33.1±14.0 ml/m(2)) acutely improved (P≤0.001), whereas functional mitral regurgitation decreased from 1.4±0.8 to 0.8±0.4 (P=0.051). Total creatine kinase levels significantly increased (P=0.017), but myocardial band isoenzyme did not (P=0.18). After 3.1±1.4 years, eight patients are alive and seven are free of recurrent heart failure. Satisfactory functional outcome can be achieved with beating-heart on-pump revascularization for postinfarction cardiogenic shock. Perioperative enzyme releases and ventricular functional variables may suggest reduced perioperative myocardial injury.

  18. A home away from home: challenges and opportunities in engineering in vitro muscle satellite cell niches.

    PubMed

    Cosgrove, Benjamin D; Sacco, Alessandra; Gilbert, Penney M; Blau, Helen M

    2009-01-01

    Satellite cells are skeletal muscle stem cells with a principal role in postnatal skeletal muscle regeneration. Satellite cells, like many tissue-specific adult stem cells, reside in a quiescent state in an instructive, anatomically defined niche. The satellite cell niche constitutes a distinct membrane-enclosed compartment within the muscle fiber, containing a diversity of biochemical and biophysical signals that influence satellite cell function. A major limitation to the study and clinical utility of satellite cells is that upon removal from the muscle fiber and plating in traditional plastic tissue culture platforms, their muscle stem cell properties are rapidly lost. Clearly, the maintenance of stem cell function is critically dependent on in vivo niche signals, highlighting the need to create novel in vitro microenvironments that allow for the maintenance and propagation of satellite cells while retaining their potential to function as muscle stem cells. Here, we discuss how emerging biomaterials technologies offer great promise for engineering in vitro microenvironments to meet these challenges. In engineered biomaterials, signaling molecules can be presented in a manner that more closely mimics cell-cell and cell-matrix interactions, and matrices can be fabricated with diverse rigidities that approximate in vivo tissues. The development of in vitro microenvironments in which niche features can be systematically modulated will be instrumental not only to future insights into muscle stem cell biology and therapeutic approaches to muscle diseases and muscle wasting with aging, but also will provide a paradigm for the analysis of numerous adult tissue-specific stem cells.

  19. Fibronectin type III domain containing 5 expression in skeletal muscle in chronic heart failure—relevance of inflammatory cytokines

    PubMed Central

    Matsuo, Yae; Gleitsmann, Konstanze; Mangner, Norman; Werner, Sarah; Fischer, Tina; Bowen, T Scott; Kricke, Angela; Matsumoto, Yasuharu; Kurabayashi, Masahiko; Schuler, Gerhard; Linke, Axel; Adams, Volker

    2015-01-01

    Background Chronic heart failure (CHF) is commonly associated with muscle atrophy and increased inflammation. Irisin, a myokine proteolytically processed by the fibronectin type III domain containing 5 (FNDC5) gene and suggested to be Peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α activated, modulates the browning of adipocytes and is related to muscle mass. Therefore, we investigated whether skeletal muscle FNDC5 expression in CHF was reduced and if this was mediated by inflammatory cytokines and/or angiotensin II (Ang-II). Methods Skeletal muscle FNDC5 mRNA/protein and PGC-1α mRNA expression (arbitrary units) were analysed in: (i) rats with ischemic cardiomyopathy; (ii) mice injected with tumour necrosis factor-α (TNF-α) (24 h); (iii) mice infused with Ang-II (4 weeks); and (iv) C2C12 myotubes exposed to recombinant cytokines or Ang-II. Circulating TNF-α, Ang-II, and irisin was measured by ELISA. Results Ischemic cardiomyopathy reduced significantly FNDC5 protein (1.3 ± 0.2 vs. 0.5 ± 0.1) and PGC-1α mRNA expression (8.2 ± 1.5 vs. 4.7 ± 0.7). In vivo TNF-α and Ang-II reduced FNDC5 protein expression by 28% and 45%, respectively. Incubation of myotubes with TNF-α, interleukin-1ß, or TNF-α/interleukin-1ß reduced FNDC5 protein expression by 47%, 37%, or 57%, respectively, whereas Ang-II had no effect. PGC-1α was linearly correlated to FNDC5 in all conditions. In CHF, animals circulating TNF-α and Ang-II were significantly increased, whereas irisin was significantly reduced. A negative correlation between circulating TNF-α and irisin was evident. Conclusion A reduced expression of skeletal muscle FNDC5 in ischemic cardiomyopathy is likely modulated by inflammatory cytokines and/or Ang-II via the down-regulation of PGC-1α. This may act as a protective mechanism either by slowing the browning of adipocytes and preserving energy homeostasis or by regulating muscle atrophy. PMID:26136413

  20. Skeletal muscle perfusion and stem cell delivery in muscle disorders using intra-femoral artery canulation in mice.

    PubMed

    Matthias, Nadine; Hunt, Samuel D; Wu, Jianbo; Darabi, Radbod

    2015-11-15

    Muscular dystrophies are among major inherited muscle disorders characterized by progressive muscle damage and fibrosis with no definitive cure. Recently, gene or cell based therapies have been developed to restore the missing gene expression or replace the damaged tissues. In order to test the efficiency of these therapies in mice models of muscular dystrophies, the arterial route of delivery is very advantageous as it provides uniform muscle exposure to the therapeutic agents or cells. Although there are few reports of arterial delivery of the therapeutic agents or cells in mice, there is no in-depth description and evaluation of its efficacy in perfusion of downstream muscles. This study is aimed to develop a practical method for intra-femoral artery perfusion in mice and to evaluate perfusion efficiency using near-infrared-fluorescence (NIRF) imaging as well as histology following stem cell delivery. Our results provide a practical guide to perform this delicate method in mice. By using a sensitive fluorescent dye, different muscle groups of the hindlimb have been evaluated for proper perfusion. As the final step, we have validated the efficiency of arterial cell delivery into muscles using human iPS-derived myogenic cells in an immunodeficient mouse model for Duchenne muscular dystrophy (NSG-mdx(4cv)).

  1. Aerobic training and l-arginine supplementation promotes rat heart and hindleg muscles arteriogenesis after myocardial infarction.

    PubMed

    Ranjbar, Kamal; Rahmani-Nia, Farhad; Shahabpour, Elham

    2016-09-01

    Arteriogenesis is a main defense mechanism to prevent heart and local tissues dysfunction in occlusive artery disease. TGF-β and angiostatin have a pivotal role in arteriogenesis. We tested the hypothesis that aerobic training and l-arginine supplementation promotes cardiac and skeletal muscles arteriogenesis after myocardial infarction (MI) parallel to upregulation of TGF-β and downregulation of angiostatin. For this purpose, 4 weeks after LAD occlusion, 50 male Wistar rats were randomly distributed into five groups: (1) sham surgery without MI (sham, n = 10), (2) control-MI (Con-MI, n = 10), (3) l-arginine-MI (La-MI, n = 10), (4) exercise training-MI (Ex-MI, n = 10), and (5) exercise and l-arginine-MI (Ex + La-MI). Exercise training groups running on a treadmill for 10 weeks with moderate intensity. Rats in the l-arginine-treated groups drank water containing 4 % l-arginine. Arteriolar density with different diameters (11-25, 26-50, 51-75, and 76-150 μm), TGF-β, and angiostatin gene expression were measured in cardiac (area at risk) and skeletal (soleus and gastrocnemius) muscles. Smaller arterioles decreased in cardiac after MI. Aerobic training and l-arginine increased the number of cardiac arterioles with 11-25 and 26-50 μm diameters parallel to TGF-β overexpression. In gastrocnemius muscle, the number of arterioles/mm(2) was only increased in the 11 to 25 μm in response to training with and without l-arginine parallel to angiostatin downregulation. Soleus arteriolar density with different size was not different between experimental groups. Results showed that 10 weeks aerobic exercise training and l-arginine supplementation promotes arteriogenesis of heart and gastrocnemius muscles parallel to overexpression of TGF-β and downregulation of angiostatin in MI rats. PMID:27121159

  2. The Scaffold Protein Muscle A-Kinase Anchoring Protein β Orchestrates Cardiac Myocyte Hypertrophic Signaling Required for the Development of Heart Failure

    PubMed Central

    Kritzer, Michael D.; Li, Jinliang; Passariello, Catherine L.; Gayanilo, Marjorie; Thakur, Hrishikesh; Dayan, Joseph; Dodge-Kafka, Kimberly; Kapiloff, Michael S.

    2014-01-01

    Background Cardiac myocyte hypertrophy is regulated by an extensive intracellular signal transduction network. In vitro evidence suggests that the scaffold protein muscle A-kinase anchoring protein β (mAKAPβ) serves as a nodal organizer of hypertrophic signaling. However, the relevance of mAKAPβ signalosomes to pathological remodeling and heart failure in vivo remains unknown. Methods and Results Using conditional, cardiac myocyte–specific gene deletion, we now demonstrate that mAKAPβ expression in mice is important for the cardiac hypertrophy induced by pressure overload and catecholamine toxicity. mAKAPβ targeting prevented the development of heart failure associated with long-term transverse aortic constriction, conferring a survival benefit. In contrast to 29% of control mice (n=24), only 6% of mAKAPβ knockout mice (n=31) died in the 16 weeks of pressure overload (P=0.02). Accordingly, mAKAPβ knockout inhibited myocardial apoptosis and the development of interstitial fibrosis, left atrial hypertrophy, and pulmonary edema. This improvement in cardiac status correlated with the attenuated activation of signaling pathways coordinated by the mAKAPβ scaffold, including the decreased phosphorylation of protein kinase D1 and histone deacetylase 4 that we reveal to participate in a new mAKAP signaling module. Furthermore, mAKAPβ knockout inhibited pathological gene expression directed by myocyte-enhancer factor-2 and nuclear factor of activated T-cell transcription factors that associate with the scaffold. Conclusions mAKAPβ orchestrates signaling that regulates pathological cardiac remodeling in mice. Targeting of the underlying physical architecture of signaling networks, including mAKAPβ signalosome formation, may constitute an effective therapeutic strategy for the prevention and treatment of pathological remodeling and heart failure. PMID:24812305

  3. Cross-bridge elasticity in single smooth muscle cells

    PubMed Central

    1983-01-01

    In smooth muscle, a cross-bridge mechanism is believed to be responsible for active force generation and fiber shortening. In the present studies, the viscoelastic and kinetic properties of the cross- bridge were probed by eliciting tension transients in response to small, rapid, step length changes (delta L = 0.3-1.0% Lcell in 2 ms). Tension transients were obtained in a single smooth muscle cell isolated from the toad (Bufo marinus) stomach muscularis, which was tied between a force transducer and a displacement device. To record the transients, which were of extremely small magnitude (0.1 microN), a high-frequency (400 Hz), ultrasensitive force transducer (18 mV/microN) was designed and built. The transients obtained during maximal force generation (Fmax = 2.26 microN) were characterized by a linear elastic response (Emax = 1.26 X 10(4) mN/mm2) coincident with the length step, which was followed by a biphasic tension recovery made up of two exponentials (tau fast = 5-20 ms, tau slow = 50-300 ms). During the development of force upon activation, transients were elicited. The relationship between stiffness and force was linear, which suggests that the transients originate within the cross-bridge and reflect the cross-bridge's viscoelastic and kinetic properties. The observed fiber elasticity suggests that the smooth muscle cross-bridge is considerably more compliant than in fast striated muscle. A thermodynamic model is presented that allows for an analysis of the factors contributing to the increased compliance of the smooth muscle cross-bridge. PMID:6413640

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

    PubMed Central

    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. PMID:23823664

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

    PubMed

    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. PMID:23823664

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

    PubMed

    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.

  7. Isolation of human umbilical arterial smooth muscle cells (HUASMC).

    PubMed

    Ribeiro, Maximiano P; Relvas, Ricardo; Chiquita, Samuel; Correia, Ilídio J

    2010-07-03

    The human umbilical cord (UC) is a biological sample that can be easily obtained just after birth. This biological sample is, most of the time, discarded and their collection does not imply any added risk to the newborn or mother s health. Moreover no ethical concerns are raised. The UC is composed by one vein and two arteries from which both endothelial cells (ECs) and smooth muscle cells (SMCs), two of the main cellular components of blood vessels, can be isolated. In this project the SMCs were obtained after enzymatic treatment of the UC arteries accordingly the experimental procedure previously described by Jaffe et al. After cell isolation they were kept in t-flash with DMEM-F12 supplemented with 5% of fetal bovine serum and were cultured for several passages. Cells maintained their morphological and other phenotypic characteristics in the different generations. The aim of this study was to isolate smooth muscle cells in order to use them as models for future assays with constrictor drugs, isolate and structurally characterize L-type calcium channels, to study cellular and molecular aspects of the vascular function and to use them in tissue engineering.

  8. Maximal enzyme activities, and myoglobin and glutathione concentrations in heart, liver and skeletal muscle of the Northern Short-tailed shrew (Blarina brevicauda; Insectivora: Soricidae).

    PubMed

    Stewart, J M; Woods, A K; Blakely, J A

    2005-07-01

    We measured the enzymes of glycolysis, Krebs Cycle, beta-oxidation and electron transport in the heart, liver and skeletal muscle of the Northern Short-tailed Shrew, Blarina brevicauda. Additionally, we measured the amount of myoglobin in skeletal and heart muscle as well as the concentration of glutathione in heart. The picture that emerges is of an aerobically well-endowed animal with constrained anaerobic capacity as indicated by small activities of glycolytic enzymes and creatine kinase. Lipid metabolism and amino acid transamination, as well as gluconeogenesis, are predominant in processing carbon resources and probably reflect the large contribution lipid and protein make to the diet of this carnivore. The citrate synthase activity is the largest of any reported value for vertebrate heart (250 U/g). The additional, very active cytochrome c oxidase activity (220 U/g) and large myoglobin concentrations (8 mg/g) in heart are clearly the underpinnings of the rapid metabolic rates reported for small insectivores. The potential for generation of reactive oxygen species must be great since the total glutathione concentration (165 mumol/g) is 300-fold greater in shrew hearts than in hearts of rats. PMID:15914053

  9. Expression profiles of muscle disease-associated genes and their isoforms during differentiation of cultured human skeletal muscle cells

    PubMed Central

    2012-01-01

    Background The formation of contractile myofibrils requires the stepwise onset of expression of muscle specific proteins. It is likely that elucidation of the expression patterns of muscle-specific sarcomeric proteins is important to understand muscle disorders originating from defects in contractile sarcomeric proteins. Methods We investigated the expression profile of a panel of sarcomeric components with a focus on proteins associated with a group of congenital disorders. The analyses were performed in cultured human skeletal muscle cells during myoblast proliferation and myotube development. Results Our culture technique resulted in the development of striated myotubes and the expression of adult isoforms of the sarcomeric proteins, such as fast TnI, fast TnT, adult fast and slow MyHC isoforms and predominantly skeletal muscle rather than cardiac actin. Many proteins involved in muscle diseases, such as beta tropomyosin, slow TnI, slow MyBPC and cardiac TnI were readily detected in the initial stages of muscle cell differentiation, suggesting the possibility of an early role for these proteins as constituent of the developing contractile apparatus during myofibrillogenesis. This suggests that in disease conditions the mechanisms of pathogenesis for each of the mutated sarcomeric proteins might be reflected by altered expression patterns, and disturbed assembly of cytoskeletal, myofibrillar structures and muscle development. Conclusions In conclusion, we here confirm that cell cultures of human skeletal muscle are an appropriate tool to study developmental stages of myofibrillogenesis. The expression of several disease-associated proteins indicates that they might be a useful model system for studying the pathogenesis of muscle diseases caused by defects in specific sarcomeric constituents. PMID:23273262

  10. Serotonin induces pulmonary artery smooth muscle cell migration

    PubMed Central

    Day, Regina M.; Agyeman, Abena S.; Segel, Michael J.; Chévere, Rubén D.; Angelosanto, Jill M.; Suzuki, Yuichiro J.; Fanburg, Barry L.

    2007-01-01

    The chronic phase of pulmonary arterial hypertension (PAH) is associated with vascular remodeling, especially thickening of the smooth muscle layer of large pulmonary arteries and muscularization of small pulmonary vessels, which normally have no associated smooth muscle. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to induce proliferation and hypertrophy of pulmonary artery smooth muscle cells (PASMC), and may be important for in vivo pulmonary vascular remodeling. Here, we show that 5-HT stimulates migration of pulmonary artery PASMC. Treatment with 5-HT for 16 h increased migration of PASMC up to four-fold as monitored in a modified Boyden chamber assay. Increased migratory responses were associated with cellular morphological changes and reorganization of the actin cytoskeleton. 5-HT-induced alterations in morphology were previously shown in our laboratory to require cAMP [Lee SL, Fanburg BL. Serotonin produces a configurational change of cultured smooth muscle cells that is associated with elevation of intracellular cAMP. J Cell Phys 1992;150(2):396–405], and the 5-HT4 receptor was pharmacologically determined to be the primary activator of cAMP in bovine PASMC [Becker BN, Gettys TW, Middleton JP, Olsen CL, Albers FJ, Lee SL, et al. 8-Hydroxy-2-(di-n-propylamino)tetralin-responsive 5-hydroxytryptamine4-like receptor expressed in bovine pulmonary artery smooth muscle cells. Mol Pharmacol 1992;42(5):817–25]. We examined the role of the 5-HT4 receptor and cAMP in 5-HT-induced bovine PASMC migration. PASMC express 5-HT4 receptor mRNA, and a 5-HT4 receptor antagonist and a cAMP antagonist completely blocked 5-HT-induced cellular migration. Consistent with our previous report that a cAMP-dependent Cl− channel is required for 5-HT-induced morphological changes in PASMC, phenylanthranilic acid, a Cl− channel blocker, inhibited actin cytoskeletal reorganization and migration produced by 5-HT. We conclude that 5-HT stimulates PASMC migration and

  11. Morphometric, quantitative, and three-dimensional analysis of the heart muscle fibers of old rats: transmission electron microscopy and high-resolution scanning electron microscopy methods.

    PubMed

    Cury, Diego Pulzatto; Dias, Fernando José; Sosthenes, Marcia Consentino Kronka; Dos Santos Haemmerle, Carlos Alexandre; Ogawa, Koichi; Da Silva, Marcelo Cavenaghi Pereira; Mardegan Issa, João Paulo; Iyomasa, Mamie Mizusaki; Watanabe, Ii-Sei

    2013-02-01

    This research investigated the morphological, morphometric, and ultrastructural cardiomyocyte characteristics of male Wistar rats at 18 months of age. The animals were euthanized using an overdose of anesthesia (ketamine and xylazine, 150/10 mg/kg) and perfused transcardially, after which samples were collected for light microscopy, transmission electron microscopy, and high-resolution scanning electron microscopy. The results showed that cardiomyocyte arrangement was disposed parallel between the mitochondria and the A-, I-, and H-bands and their M- and Z-lines from the sarcomere. The sarcomere junction areas had intercalated disks, a specific structure of heart muscle. The ultrastructural analysis revealed several mitochondria of various sizes and shapes intermingled between the blood capillaries and their endothelial cells; some red cells inside vessels are noted. The muscle cell sarcolemma could be observed associated with the described structures. The cardiomyocytes of old rats presented an average sarcomere length of 2.071 ± 0.09 μm, a mitochondrial volume density (Vv) of 0.3383, a mitochondrial average area of 0.537 ± 0.278 μm(2), a mitochondrial average length of 1.024 ± 0.352 μm, an average mitochondrial cristae thickness of 0.038 ± 0.09 μm and a ratio of mitochondrial greater length/lesser length of 1.929 ± 0.965. Of the observed mitochondrial shapes, 23.4% were rounded, 45.3% were elongated, and 31.1% had irregular profiles. In this study, we analyzed the morphology and morphometry of cardiomyocytes in old rats, focusing on mitochondria. These data are important for researchers who focus the changes in cardiac tissue, especially changes owing to pathologies and drug administration that may or may not be correlated with aging.

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

    PubMed

    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.

  13. Cyclooxygenase-2 in Endothelial and Vascular Smooth Muscle Cells Restrains Atherogenesis in Hyperlipidemic Mice

    PubMed Central

    Tang, Soon Yew; Monslow, James; Todd, Leslie; Lawson, John; Puré, Ellen; FitzGerald, Garret A.

    2014-01-01

    Background Placebo controlled trials of nonsteroidal antinflammatory drugs (NSAIDs) selective for inhibition of COX-2 reveal an emergent cardiovascular hazard in patients selected for low risk of heart disease. Postnatal global deletion of COX-2 accelerates atherogenesis in hyperlipidemic mice, a process delayed by selective enzyme deletion in macrophages. Methods and Results Here, selective depletion of COX-2 in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) depressed biosynthesis of prostaglandin (PG)I2 and PGE2, elevated blood pressure and accelerated atherogenesis in Ldlr knockout (KO) mice. Deletion of COX-2 in VSMCs and ECs coincided with an increase in COX-2 expression in lesional macrophages and increased biosynthesis of thromboxane. Increased accumulation of less organized intimal collagen, laminin, α-smooth muscle actin and matrix-rich fibrosis was also apparent in lesions of the mutants. Conclusions Although atherogenesis is accelerated in global COX-2 KOs, consistent with evidence of risk transformation during chronic NSAID administration, this masks the contrasting effects of enzyme depletion in macrophages versus VSMCs and ECs. Targeting delivery of COX-2 inhibitors to macrophages may conserve their efficacy while limiting cardiovascular risk. PMID:24519928

  14. Differential Response of Heat Shock Proteins to Uphill and Downhill Exercise in Heart, Skeletal Muscle, Lung and Kidney Tissues

    PubMed Central

    Lollo, Pablo C. B.; Moura, Carolina S.; Morato, Priscila N.; Amaya-Farfan, Jaime

    2013-01-01

    Running on a horizontal plane is known to increase the concentration of the stress biomarker heat-shock protein (HSP), but no comparison of the expression of HSP70 has yet been established between the uphill (predominantly concentric) and downhill (predominantly eccentric) muscle contractions exercise. The objective of the study was to investigate the relationships between eccentric and concentric contractions on the HSP70 response of the lung, kidney, gastrocnemius, soleus and heart. Twenty-four male Wistar weanling rats were divided into four groups: non-exercised and three different grades of treadmill exercise groups: horizontal, uphill (+7%) and downhill (-7% of inclination). At the optimal time-point of six hours after the exercise, serum uric acid, creatine kinase (CK) and lactate dehydrogenase (LDH) were determined by standard methods and HSP70 by the Western blot analysis. HSP70 responds differently to different types of running. For kidney, heart, soleus and gastrocnemius, the HSP70 expression increased, 230, 180, 150 and 120% respectively of the reference (horizontal). When the contraction was concentric (uphill) and compared to downhill the increase in response of HSP70 was greater in 80% for kidney, 75% for gastrocnemius, 60% for soleus and 280% for the heart. Uric acid was about 50% higher (0.64 ± 0.03 mg·dL−1) in the uphill group as compared to the horizontal or downhill groups. Similarly, the activities of serum CK and LDH were both 100% greater for both the uphill and downhill groups as compared to the horizontal group (2383 ± 253 and 647.00 ± 73 U/L, respectively). The responsiveness of HSP70 appeared to be quite different depending on the type of tissue, suggesting that the impact of exercise was not restricted to the muscles, but extended to the kidney tissue. The uphill exercise increases HSP70 beyond the eccentric type and the horizontal running was a lower HSP70 responsive stimulus. Key Points Exercise can induce increases in HSP70 in

  15. Skeletal Muscle Satellite Cells: Background and Methods for Isolation and Analysis in a Primary Culture System

    PubMed Central

    Danoviz, Maria Elena; Yablonka-Reuveni, Zipora

    2012-01-01

    Summary Repair of adult skeletal muscle depends on satellite cells, myogenic stem cells located between the basal lamina and the plasmalemma of the myofiber. Standardized protocols for the isolation and culture of satellite cells are key tools for understanding cell autonomous and extrinsic factors that regulate their performance. Knowledge gained from such studies can contribute important insights to developing strategies for the improvement of muscle repair following trauma and in muscle wasting disorders. This chapter provides an introduction to satellite cell biology and further describes the basic protocol used in our laboratory to isolate and culture satellite cells from adult skeletal muscle. The cell culture conditions detailed herein support proliferation and differentiation of satellite cell progeny and the development of reserve cells, which are thought to reflect the in vivo self-renewal ability of satellite cells. Additionally, this chapter describes our standard immunostaining protocol that allows the characterization of satellite cell progeny by the temporal expression of characteristic transcription factors and structural proteins associated with different stages of myogenic progression. While emphasis is given here to the isolation and characterization of satellite cells from mouse hindlimb muscles, the protocols are suitable for other muscle types (such as diaphragm and extraocular muscles) and for muscles from other species, including chicken and rat. Altogether, the basic protocols described are straightforward and facilitate the study of diverse aspects of skeletal muscle stem cells. PMID:22130829

  16. Pharyngeal Satellite Cells Undergo Myogenesis Under Basal Conditions and Are Required for Pharyngeal Muscle Maintenance.

    PubMed

    Randolph, Matthew E; Phillips, Brittany L; Choo, Hyo-Jung; Vest, Katherine E; Vera, Yandery; Pavlath, Grace K

    2015-12-01

    The pharyngeal muscles of the nasal, oral, and laryngeal pharynxes are required for swallowing. Pharyngeal muscles are preferentially affected in some muscular dystrophies yet spared in others. Muscle stem cells, called satellite cells, may be critical factors in the development of pharyngeal muscle disorders; however, very little is known about pharyngeal satellite cells (PSC) and their role in pharyngeal muscles. We show that PSC are distinct from the commonly studied hindlimb satellite cells both transcriptionally and biologically. Under basal conditions PSC proliferate, progress through myogenesis, and fuse with pharyngeal myofibers. Furthermore, PSC exhibit biologic differences dependent on anatomic location in the pharynx. Importantly, PSC are required to maintain myofiber size and myonuclear number in pharyngeal myofibers. Together, these results demonstrate that PSC are critical for pharyngeal muscle maintenance and suggest that satellite cell impairment could contribute to pharyngeal muscle pathology associated with various muscular dystrophies and aging.

  17. Breakthroughs in Cell Therapy for Heart Disease: Focus on Cardiosphere-Derived Cells

    PubMed Central

    Marbán, Eduardo

    2014-01-01

    The clinical reality of cell therapy for heart disease dates back to the 1990s, when autologous skeletal myoblasts were first transplanted into failing hearts during open-chest surgery. Since then, the focus has shifted to bone marrow-derived cells and, more recently, cells extracted from the heart itself. While progress has been nonlinear and often disheartening, the field has nevertheless made remarkable progress. Six major breakthroughs are notable: 1) The establishment of safety with intracoronary delivery; 2) The demonstration that therapeutic regeneration is possible; 3) The rise of allogeneic cell therapy; 4) The impact of increasing mechanistic insights; 5) Glimmers of clinical efficacy; and 6) The progression to phase 2&3 studies. Here I review these landmark developments individually in some detail. Collectively, I conclude that the field has reached a new phase of maturity where the prospect of clinical impact is increasingly imminent. PMID:24943699

  18. Aldehyde dehydrogenase activity promotes survival of human muscle precursor cells

    PubMed Central

    Jean, Elise; Laoudj-Chenivesse, Dalila; Notarnicola, Cécile; Rouger, Karl; Serratrice, Nicolas; Bonnieu, Anne; Gay, Stéphanie; Bacou, Francis; Duret, Cédric; Carnac, Gilles

    2011-01-01

    Abstract Aldehyde dehydrogenases (ALDH) are a family of enzymes that efficiently detoxify aldehydic products generated by reactive oxygen species and might therefore participate in cell survival. Because ALDH activity has been used to identify normal and malignant cells with stem cell properties, we asked whether human myogenic precursor cells (myoblasts) could be identified and isolated based on their levels of ALDH activity. Human muscle explant-derived cells were incubated with ALDEFLUOR, a fluorescent substrate for ALDH, and we determined by flow cytometry the level of enzyme activity. We found that ALDH activity positively correlated with the myoblast-CD56+ fraction in those cells, but, we also observed heterogeneity of ALDH activity levels within CD56-purified myoblasts. Using lentiviral mediated expression of shRNA we demonstrated that ALDH activity was associated with expression of Aldh1a1 protein. Surprisingly, ALDH activity and Aldh1a1 expression levels were very low in mouse, rat, rabbit and non-human primate myoblasts. Using different approaches, from pharmacological inhibition of ALDH activity by diethylaminobenzaldehyde, an inhibitor of class I ALDH, to cell fractionation by flow cytometry using the ALDEFLUOR assay, we characterized human myoblasts expressing low or high levels of ALDH. We correlated high ALDH activity ex vivo to resistance to hydrogen peroxide (H2O2)-induced cytotoxic effect and in vivo to improved cell viability when human myoblasts were transplanted into host muscle of immune deficient scid mice. Therefore detection of ALDH activity, as a purification strategy, could allow non-toxic and efficient isolation of a fraction of human myoblasts resistant to cytotoxic damage. PMID:19840193

  19. Cell-Cell Interactions Mediate the Response of Vascular Smooth Muscle Cells to Substrate Stiffness

    PubMed Central

    Sazonova, Olga V.; Lee, Kristen L.; Isenberg, Brett C.; Rich, Celeste B.; Nugent, Matthew A.; Wong, Joyce Y.

    2011-01-01

    The vessel wall experiences progressive stiffening with age and the development of cardiovascular disease, which alters the micromechanical environment experienced by resident vascular smooth muscle cells (VSMCs). In vitro studies have shown that VSMCs are sensitive to substrate stiffness, but the exact molecular mechanisms of their response to stiffness remains unknown. Studies have also shown that cell-cell interactions can affect mechanotransduction at the cell-substrate interface. Using flexible substrates, we show that the expression of proteins associated with cell-matrix adhesion and cytoskeletal tension is regulated by substrate stiffness, and that an increase in cell density selectively attenuates some of these effects. We also show that cell-cell interactions exert a strong effect on cell morphology in a substrate-stiffness dependent manner. Collectively, the data suggest that as VSMCs form cell-cell contacts, substrate stiffness becomes a less potent regulator of focal adhesion signaling. This study provides insight into the mechanisms by which VSMCs respond to the mechanical environment of the blood vessel wall, and point to cell-cell interactions as critical mediators of VSMC response to vascular injury. PMID:21806930

  20. Cell Labeling and Injection in Developing Embryonic Mouse Hearts

    PubMed Central

    Dirschinger, Ralf J.; Evans, Sylvia M.; Puceat, Michel

    2014-01-01

    Testing the fate of embryonic or pluripotent stem cell-derivatives in in vitro protocols has led to controversial outcomes that do not necessarily reflect their in vivo potential. Preferably, these cells should be placed in a proper embryonic environment in order to acquire their definite phenotype. Furthermore, cell lineage tracing studies in the mouse after labeling cells with dyes or retroviral vectors has remained mostly limited to early stage mouse embryos with still poorly developed organs. To overcome these limitations, we designed standard and ultrasound-mediated microinjection protocols to inject various agents in targeted regions of the heart in mouse embryos at E9.5 and later stages of development.  Embryonic explant or embryos are then cultured or left to further develop in utero. These agents include fluorescent dyes, virus, shRNAs, or stem cell-derived progenitor cells. Our approaches allow for preservation of the function of the organ while monitoring migration and fate of labeled and/or injected cells. These technologies can be extended to other organs and will be very helpful to address key biological questions in biology of development. PMID:24797676

  1. Multipotent (adult) and pluripotent stem cells for heart regeneration: what are the pros and cons?

    PubMed

    Liao, Song-Yan; Tse, Hung-Fat

    2013-12-24

    Heart failure after myocardial infarction is the leading cause of mortality and morbidity worldwide. Existing medical and interventional therapies can only reduce the loss of cardiomyocytes during myocardial infarction but are unable to replenish the permanent loss of cardiomyocytes after the insult, which contributes to progressive pathological left ventricular remodeling and progressive heart failure. As a result, cell-based therapies using multipotent (adult) stem cells and pluripotent stem cells (embryonic stem cells or induced pluripotent stem cells) have been explored as potential therapeutic approaches to restore cardiac function in heart failure. Nevertheless, the optimal cell type with the best therapeutic efficacy and safety for heart regeneration is still unknown. In this review, the potential pros and cons of different types of multipotent (adult) stem cells and pluripotent stem cells that have been investigated in preclinical and clinical studies are reviewed, and the future perspective of stem cell-based therapy for heart regeneration is discussed.

  2. Muscle cell membranes from early degeneration muscle cell fibers in Solenopsis are leaky to lanthanum: electron microscopy and X-ray analysis

    SciTech Connect

    Jones, R.G.; Davis, W.L.

    1985-06-01

    Lanthanum infusion techniques, transmission electron microscopy, and X-ray microanalysis were utilized to compare the permeability of muscle cell membranes from normal and degenerating muscle fibers of Solenopsis spp. In normal fibers, the electron-dense tracer was limited to components of the sarcotubular system. However, the insemination-induced degeneration of muscle fibers was characterized by the presence of an electron-dense precipitate within the myofibrils and mitochondria as well as in the extramyofibrillar spaces. The electron-dense material was subsequently identified by elemental analysis to be lanthanum. Such data indicate that one of the earliest stages of muscle degeneration involves an alteration in cell membrane permeability.

  3. THE DISTRIBUTION OF THE ACTION CURRENTS PRODUCED BY HEART MUSCLE AND OTHER EXCITABLE TISSUES IMMERSED IN EXTENSIVE CONDUCTING MEDIA.

    PubMed

    Wilson, F N; Macleod, A G; Barker, P S

    1933-01-20

    The action currents produced by heart muscle and other tissues immersed in or in contact with a large body of conducting material are distributed in accordance with the laws that govern the flow of electric currents in volume conductors. The curve obtained when one electrode (the exploring electrode) is placed very close to and the other (the indifferent electrode) very far from the active tissue may be regarded as representing the potential variations of the exploring electrode alone; the. potential of the indifferent electrode is by comparison nearly constant. Curves obtained by this method of leading from the surface of the mammalian auricle indicate that the electrical effects produced by the passage of the excitation wave along a single muscle fiber are nearly the same as those that would occur if the crest of this wave were immediately preceded by a source and followed by a sink. A study of the electric field of a polarized membrane immersed in a volume conductor shows that this conclusion may be derived on theoretical grounds from the membrane theory of Bernstein.

  4. Inotropic effects of ethanol and dihydropyridines on the guinea pig heart atrial muscle

    SciTech Connect

    Salvatici, R.P. ); Gallardo-Carpentier, A.; Carpentier, R.G. ); Isaacson, R.L. )

    1990-01-01

    The effects of ethanol and/or dihydropyridines (DHPs) on force of contraction of atrial muscle were studied. Guinea pig atrial strips superfused with Tyrode's solution were driven while recording muscle tension. Bay K 8644 (BAYK) increased, while nimodipine or ethanol reduced, the peak tension developed and the maximum velocity of development of tension. The effects of ethanol were readily reversible, but those of the DHPs were not. The combined actions of ethanol and DHPs were the result of the synergism or antagonism of the drugs tested. The shorter duration of the action of ethanol resulted in the effect of DHPs being still evident well after the exposure to the drugs ended. In summary, ethanol and nimodipine exerted depressant actions on atrial contractile force, while BAYK had opposite effects. The different mechanisms of action may explain the different duration of the effects of ethanol and DHPs.

  5. Bispyridinium non-oximes: An evaluation of cardiac effects in isolated hearts and smooth muscle relaxing effects in jejunum.

    PubMed

    Neumaier, Katharina; Worek, Franz; Thiermann, Horst; Wille, Timo

    2016-09-01

    Bispyridinium non-oximes seem to be promising candidates for the generic treatment of nerve agent poisoning as they interact with nicotinic and muscarinic acetylcholine receptors. The lead compound MB327 showed therapeutic effectiveness in vitro and in vivo but was toxic at higher doses. In the present study, the effect of various bispyridinium non-oximes on isolated heart and small intestine function was investigated. Bispyridinium non-oximes and oximes were tested in at least seven different concentrations in rat jejunum preparations pre-treated with carbachol. All bispyridinium non-oximes showed classical dose response curves with MB327 being the most effective (EC50=6.6μM) and MB782 being slightly less effective (EC50=10.4μM). Neither the bispyridinium non-oximes nor the oximes showed cardiotoxic effects in the isolated Langendorff heart. The tested bispyridinum compounds showed no direct cardiac effect but had variable smooth muscle relaxing effects. Further in vivo studies are required to get more insight into potential toxic mechanisms of these promising nerve agent antidotes. PMID:27184650

  6. Increases in muscle sympathetic nerve activity, heart rate, respiration, and skin blood flow during passive viewing of exercise.

    PubMed

    Brown, Rachael; Kemp, Ursula; Macefield, Vaughan

    2013-01-01

    The cardiovascular and respiratory effects of exercise have been widely studied, as have the autonomic effects of imagined and observed exercise. However, the effects of observed exercise in the first person have not been documented, nor have direct recordings of muscle sympathetic nerve activity (MSNA) been obtained during observed or imagined exercise. The aim of the current study was to measure blood pressure, heart rate, respiration, skin blood flow, sweat release, and MSNA (via microelectrodes inserted into the common peroneal nerve), during observation of exercise from the first person point of view. It was hypothesized that the moving stimuli would produce robust compensatory increases in the above-mentioned parameters as effectively as those generated by mental imagery and-to a lesser extent-actual exercise. Nine subjects watched a first-person running video, allowing them to view the action from the perspective of the runner rather than viewing someone else perform the exercise. On average, statistically significant increases from baseline during the running phase were seen in heart rate, respiratory rate, skin blood flow, and burst amplitude of MSNA. These results suggest that observation of exercise in the first person is a strong enough stimulus to evoke "physiologically appropriate" autonomic responses that have a purely psychogenic origin.

  7. Myoid cell density in the thymus is reduced during mdx dystrophy and after muscle crush.

    PubMed

    Wong, A; Garrett, K L; Anderson, J E

    1999-01-01

    Thymic myoid cells share structural and behavioural features with cells of the skeletal muscle lineage: they express regulatory genes and contractile proteins, and they can form myofibers in culture. Historically, those features suggested that myoid cells could be precursors for muscle repair in addition to the satellite cells in muscle that are typically designated as the only muscle precursors. Muscles of the mutant mdx dystrophic mouse strain have a large demand for precursors, which is greatest at a young age. In the present study, immunostaining for troponin T was used to localize myoid cells. We tested the hypothesis that the myoid cell population changes when there is a demand for muscle precursors and that these changes would be anticipated if myoid cells have a role as myogenic precursors or stem cells in muscle. Chronic demands for muscle precursors in mdx dystrophic mice were accompanied by lower myoid cell density in comparison with density in two normal strains (C57BL10/ScSn and Swiss Webster). Acute demand for precursors was accompanied by a sharp decline in thymic myoid cell density within 2 days after a crush injury to one tibialis anterior muscle in normal but not dystrophic animals. To standardize the developmental age of the thymus, density was determined in all animals at 28 days of age. Given the current interest in nonmuscle sources of myogenic stem cells, these data suggest that changes in the density of thymic myoid cells may accompany acute and chronic demands for muscle precursors. Further experiments are required to determine whether thymic myoid cells are participants in distant muscle cell proliferation, new fiber formation, or the establishment of new stem cells in regenerated muscle.

  8. Inward rectifying potassium channels facilitate cell-to-cell communication in hamster retractor muscle feed arteries.

    PubMed

    Jantzi, Micaela C; Brett, Suzanne E; Jackson, William F; Corteling, Randolph; Vigmond, Edward J; Welsh, Donald G

    2006-09-01

    This study examined whether inward rectifying K+ (KIR) channels facilitate cell-to-cell communication along skeletal muscle resistance arteries. With the use of feed arteries from the hamster retractor muscle, experiments examined whether KIR channels were functionally expressed and whether channel blockade attenuated the conduction of acetylcholine-induced vasodilation, an index of cell-to-cell communication. Consistent with KIR channel expression, this study observed the following: 1) a sustained Ba2+-sensitive, K+-induced dilation in preconstricted arteries; 2) a Ba2+-sensitive inwardly rectifying K+ current in arterial smooth muscle cells; and 3) KIR2.1 and KIR2.2 expression in the smooth muscle layer of these arteries. It was subsequently shown that the discrete application of acetylcholine elicits a vasodilation that conducts with limited decay along the feed artery wall. In the presence of 100 microM Ba2+, the local and conducted response to acetylcholine was attenuated, a finding consistent with a role for KIR in facilitating cell-to-cell communication. A computational model of vascular communication accurately predicted these observations. Control experiments revealed that in contrast to Ba2+, ATP-sensitive- and large-conductance Ca2+ activated-K+ channel inhibitors had no effect on the local or conducted vasodilatory response to acetylcholine. We conclude that smooth muscle KIR channels play a key role in facilitating cell-to-cell communication along skeletal muscle resistance arteries. We attribute this facilitation to the intrinsic property of negative slope conductance, a biophysical feature common to KIR2.1- and 2.2-containing channels, which enables them to increase their activity as a cell hyperpolarizes. PMID:16617135

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

    SciTech Connect

    Bhagavati, Satyakam . E-mail: satyakamb@hotmail.com; Xu Weimin

    2005-07-29

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

  10. Myosin light chain phosphorylation enhances contraction of heart muscle via structural changes in both thick and thin filaments.

    PubMed

    Kampourakis, Thomas; Sun, Yin-Biao; Irving, Malcolm

    2016-05-24

    Contraction of heart muscle is triggered by calcium binding to the actin-containing thin filaments but modulated by structural changes in the myosin-containing thick filaments. We used phosphorylation of the myosin regulatory light chain (cRLC) by the cardiac isoform of its specific kinase to elucidate mechanisms of thick filament-mediated contractile regulation in demembranated trabeculae from the rat right ventricle. cRLC phosphorylation enhanced active force and its calcium sensitivity and altered thick filament structure as reported by bifunctional rhodamine probes on the cRLC: the myosin head domains became more perpendicular to the filament axis. The effects of cRLC phosphorylation on thick filament structure and its calcium sensitivity were mimicked by increasing sarcomere length or by deleting the N terminus of the cRLC. Changes in thick filament structure were highly cooperative with respect to either calcium concentration or extent of cRLC phosphorylation. Probes on unphosphorylated myosin heads reported similar structural changes when neighboring heads were phosphorylated, directly demonstrating signaling between myosin heads. Moreover probes on troponin showed that calcium sensitization by cRLC phosphorylation is mediated by the thin filament, revealing a signaling pathway between thick and thin filaments that is still present when active force is blocked by Blebbistatin. These results show that coordinated and cooperative structural changes in the thick and thin filaments are fundamental to the physiological regulation of contractility in the heart. This integrated dual-filament concept of contractile regulation may aid understanding of functional effects of mutations in the protein components of both filaments associated with heart disease.

  11. Myosin light chain phosphorylation enhances contraction of heart muscle via structural changes in both thick and thin filaments

    PubMed Central

    Kampourakis, Thomas; Sun, Yin-Biao; Irving, Malcolm

    2016-01-01

    Contraction of heart muscle is triggered by calcium binding to the actin-containing thin filaments but modulated by structural changes in the myosin-containing thick filaments. We used phosphorylation of the myosin regulatory light chain (cRLC) by the cardiac isoform of its specific kinase to elucidate mechanisms of thick filament-mediated contractile regulation in demembranated trabeculae from the rat right ventricle. cRLC phosphorylation enhanced active force and its calcium sensitivity and altered thick filament structure as reported by bifunctional rhodamine probes on the cRLC: the myosin head domains became more perpendicular to the filament axis. The effects of cRLC phosphorylation on thick filament structure and its calcium sensitivity were mimicked by increasing sarcomere length or by deleting the N terminus of the cRLC. Changes in thick filament structure were highly cooperative with respect to either calcium concentration or extent of cRLC phosphorylation. Probes on unphosphorylated myosin heads reported similar structural changes when neighboring heads were phosphorylated, directly demonstrating signaling between myosin heads. Moreover probes on troponin showed that calcium sensitization by cRLC phosphorylation is mediated by the thin filament, revealing a signaling pathway between thick and thin filaments that is still present when active force is blocked by Blebbistatin. These results show that coordinated and cooperative structural changes in the thick and thin filaments are fundamental to the physiological regulation of contractility in the heart. This integrated dual-filament concept of contractile regulation may aid understanding of functional effects of mutations in the protein components of both filaments associated with heart disease. PMID:27162358

  12. Self-organization of muscle cell structure and function.

    PubMed

    Grosberg, Anna; Kuo, Po-Ling; Guo, Chin-Lin; Geisse, Nicholas A; Bray, Mark-Anthony; Adams, William J; Sheehy, Sean P; Parker, Kevin Kit

    2011-02-01

    The organization of muscle is the product of functional adaptation over several length scales spanning from the sarcomere to the muscle bundle. One possible strategy for solving this multiscale coupling problem is to physically constrain the muscle cells in microenvironments that potentiate the organization of their intracellular space. We hypothesized that boundary conditions in the extracellular space potentiate the organization of cytoskeletal scaffolds for directed sarcomeregenesis. We developed a quantitative model of how the cytoskeleton of neonatal rat ventricular myocytes organizes with respect to geometric cues in the extracellular matrix. Numerical results and in vitro assays to control myocyte shape indicated that distinct cytoskeletal architectures arise from two temporally-ordered, organizational processes: the interaction between actin fibers, premyofibrils and focal adhesions, as well as cooperative alignment and parallel bundling of nascent myofibrils. Our results suggest that a hierarchy of mechanisms regulate the self-organization of the contractile cytoskeleton and that a positive feedback loop is responsible for initiating the break in symmetry, potentiated by extracellular boundary conditions, is required to polarize the contractile cytoskeleton.

  13. Endometrial regenerative cells for treatment of heart failure: a new stem cell enters the clinic.

    PubMed

    Bockeria, Leo; Bogin, Vladimir; Bockeria, Olga; Le, Tatyana; Alekyan, Bagrat; Woods, Erik J; Brown, Amalia A; Ichim, Thomas E; Patel, Amit N

    2013-01-01

    Heart failure is one of the key causes of morbidity and mortality world-wide. The recent findings that regeneration is possible in the heart have made stem cell therapeutics the Holy Grail of modern cardiovascular medicine. The success of cardiac regenerative therapies hinges on the combination of an effective allogeneic "off the shelf" cell product with a practical delivery system. In 2007 Medistem discovered the Endometrial Regenerative Cell (ERC), a new mesenchymal-like stem cell. Medistem and subsequently independent groups have demonstrated that ERC are superior to bone marrow mesenchymal stem cells (MSC), the most widely used stem cell source in development. ERC possess robust expansion capability (one donor can generate 20,000 patients doses), key growth factor production and high levels of angiogenic activity. ERC have been published in the peer reviewed literature to be significantly more effect at treating animal models of heart failure (Hida et al. Stem Cells 2008).Current methods of delivering stem cells into the heart suffer several limitations in addition to poor delivery efficiency. Surgical methods are highly invasive, and the classical catheter based techniques are limited by need for sophisticated cardiac mapping systems and risk of myocardial perforation. Medistem together with Dr. Amit Patel Director of Clinical Regenerative Medicine at University of Utah have developed a novel minimally invasive delivery method that has been demonstrated safe and effective for delivery of stem cells (Tuma et al. J Transl Med 2012). Medistem is evaluating the combination of ERC, together with our retrograde delivery procedure in a 60 heart failure patient, double blind, placebo controlled phase II trial. To date 17 patients have been dosed and preliminary analysis by the Data Safety Monitoring Board has allowed for trial continuation.The combined use of a novel "off the shelf" cell together with a minimally invasive 30 minute delivery method provides a

  14. Biophysical Induction of Vascular Smooth Muscle Cell Podosomes

    PubMed Central

    Kim, Na Young; Kohn, Julie C.; Huynh, John; Carey, Shawn P.; Mason, Brooke N.; Vouyouka, Ageliki G.; Reinhart-King, Cynthia A.

    2015-01-01

    Vascular smooth muscle cell (VSMC) migration and matrix degradation occurs with intimal hyperplasia associated with atherosclerosis, vascular injury, and restenosis. One proposed mechanism by which VSMCs degrade matrix is through the use of podosomes, transient actin-based structures that are thought to play a role in extracellular matrix degradation by creating localized sites of matrix metalloproteinase (MMP) secretion. To date, podosomes in VSMCs have largely been studied by stimulating cells with phorbol esters, such as phorbol 12,13-dibutyrate (PDBu), however little is known about the physiological cues that drive podosome formation. We present the first evidence that physiological, physical stimuli mimicking cues present within the microenvironment of diseased arteries can induce podosome formation in VSMCs. Both microtopographical cues and imposed pressure mimicking stage II hypertension induce podosome formation in A7R5 rat aortic smooth muscle cells. Moreover, wounding using a scratch assay induces podosomes at the leading edge of VSMCs. Notably the effect of each of these biophysical stimuli on podosome stimulation can be inhibited using a Src inhibitor. Together, these data indicate that physical cues can induce podosome formation in VSMCs. PMID:25785437

  15. Calpeptin Attenuated Apoptosis and Intracellular Inflammatory Changes in Muscle Cells

    PubMed Central

    Nozaki, Kenkichi; Das, Arabinda; Ray, Swapan K.; Banik, Naren L.

    2011-01-01

    In idiopathic inflammatory myopathies (IIMs), extracellular inflammatory stimulation is considered to induce secondary intracellular inflammatory changes including expression of major histocompatibility complex class-I (MHC-I) and to produce self-sustaining loop of inflammation. We hypothesize that activation of calpain, a Ca2+-sensitive protease, bridges between these extracellular inflammatory stress and intracellular secondary inflammatory changes in muscle cells. In this study, we demonstrated that treatment of rat L6 myoblast cells with interferon-gamma (IFN-γ) caused expression of MHC-I and inflammation related transcription factors (phosphorylated-extracellular signal-regulated kinase 1/2 and nuclear factor-kappa B). We also demonstrated that treatment with tumor necrosis factor-alpha (TNF-α) induced apoptotic changes and activation of calpain and cyclooxygenase-2. Further, we found that post-treatment with calpeptin attenuated the intracellular changes induced by IFN-γ or TNF-α. Our results indicate that calpain inhibition attenuates apoptosis and secondary inflammatory changes induced by extracellular inflammatory stimulation in the muscle cells. These results suggest calpain as a potential therapeutic target for treatment of IIMs. PMID:21290412

  16. Induced Pluripotent Stem Cell-derived Vascular Smooth Muscle Cells: Methods and Application

    PubMed Central

    Dash, Biraja C.; Jiang, Zhengxin; Suh, Carol; Qyang, Yibing

    2015-01-01

    Vascular smooth muscle cells (VSMCs) play a major role in the pathophysiology of cardiovascular diseases. The advent of induced pluripotent stem cell (iPSC) technology and their capability to differentiation into virtually every cell type in the human body make this field a ray of hope for vascular regenerative therapy and for understanding disease mechanism. In this review, we first discuss the recent iPSC technology and vascular smooth muscle development from embryo and then examine different methodology to derive VSMCs from iPSCs and their applications in regenerative therapy and disease modeling. PMID:25559088

  17. Heart attack

    MedlinePlus

    ... infarction; Non-ST - elevation myocardial infarction; NSTEMI; CAD - heart attack; Coronary artery disease - heart attack ... made up of cholesterol and other cells. A heart attack may occur when: A tear in the ...

  18. Endothelial cells regulate neural crest and second heart field morphogenesis

    PubMed Central

    Milgrom-Hoffman, Michal; Michailovici, Inbal; Ferrara, Napoleone; Zelzer, Elazar; Tzahor, Eldad

    2014-01-01

    ABSTRACT Cardiac and craniofacial developmental programs are intricately linked during early embryogenesis, which is also reflected by a high frequency of birth defects affecting both regions. The molecular nature of the crosstalk between mesoderm and neural crest progenitors and the involvement of endothelial cells within the cardio–craniofacial field are largely unclear. Here we show in the mouse that genetic ablation of vascular endothelial growth factor receptor 2 (Flk1) in the mesoderm results in early embryonic lethality, severe deformation of the cardio–craniofacial field, lack of endothelial cells and a poorly formed vascular system. We provide evidence that endothelial cells are required for migration and survival of cranial neural crest cells and consequently for the deployment of second heart field progenitors into the cardiac outflow tract. Insights into the molecular mechanisms reveal marked reduction in Transforming growth factor beta 1 (Tgfb1) along with changes in the extracellular matrix (ECM) composition. Our collective findings in both mouse and avian models suggest that endothelial cells coordinate cardio–craniofacial morphogenesis, in part via a conserved signaling circuit regulating ECM remodeling by Tgfb1. PMID:24996922

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

    PubMed

    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.

  20. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

    Nyamekye, Isaac; Renick, R.; Gilbert, C.; McEwan, Jean R.; Evan, G.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-03-01

    PDT kills smooth muscle cells (SMC) in vivo and thus prevents intimal hyperplasia after angioplasty. It causes little inflammation and structural integrity of the artery is not compromised. We have studied the process of the SMC death in vitro. Cultured rat SMC (cell line sv40 ATCC) were sensitized with aluminum disulphonated phthalocyanine (AlS2Pc), and then irradiated with 675 nm laser light (2.5 J/cm2). Controls were studied using only sensitizer or laser for treatment. The cells were incubated and the dying process observed with a time lapse video and microscope system. PDT caused a characteristic pattern of death. Cells lost contact with neighbors, shrank, and showed hyperactivity and membrane ruffling. The cells imploded into active and condensed membrane bound vesicles which were terminally reduced to residual bodies. These are the morphological changes of apoptosis. The control cells which were given AlS2Pc alone or laser alone showed no death. PDT induced cultured arterial SMC death by apoptosis rather than necrosis. An apoptotic mechanism of cell death in vivo would explain the relative lack of inflammation and local tissue destruction in the face of massive death.

  1. Mononuclear muscle cells in Drosophila ovaries revealed by GFP protein traps

    PubMed Central

    Hudson, Andrew M.; Petrella, Lisa N.; Tanaka, Akemi J.; Cooley, Lynn

    2008-01-01

    Genetic analysis of muscle specification, formation and function in model systems has provided valuable insight into human muscle physiology and disease. Studies in Drosophila have been particularly useful for discovering key genes involved in muscle specification, myoblast fusion, and sarcomere organization. The muscles of the Drosophila female reproductive system have received little attention despite extensive work on oogenesis. We have used newly available GFP protein trap lines to characterize of ovarian muscle morphology and sarcomere organization. The muscle cells surrounding the oviducts are multinuclear with highly organized sarcomeres typical of somatic muscles. In contrast, the two muscle layers of the ovary, which are derived from gonadal mesoderm, have a mesh-like morphology similar to gut visceral muscle. Protein traps in the Fasciclin 3 gene produced Fas3::GFP that localized in dots around the periphery of epithelial sheath cells, the muscle surrounding ovarioles. Surprisingly, the epithelial sheath cells each contain a single nucleus, indicating these cells do not undergo myoblast fusion during development. Consistent with this observation, we were able to use the Flp/FRT system to efficiently generate genetic mosaics in the epithelial sheath, suggesting these cells provide a new opportunity for clonal analysis of adult striated muscle. PMID:18199432

  2. T lymphocytes adhere to airway smooth muscle cells via integrins and CD44 and induce smooth muscle cell DNA synthesis

    PubMed Central

    1994-01-01

    Asthma is a disease of airway inflammation and hyperreactivity that is associated with a lymphocytic infiltrate in the bronchial submucosa. The interactions between infiltrating T lymphocytes with cellular and extracellular matrix components of the airway and the consequences of these interactions have not been defined. We demonstrate the constitutive expression of CD44 on human airway smooth muscle (ASM) cells in culture as well as in human bronchial tissue transplanted into severe combined immunodeficient mice. In contrast, basal levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) expression are minimal but are induced on ASM by inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha). Activated, but not resting T cells, adhere to cultured ASM; stimulation of the ASM with TNF-alpha enhanced this adhesion. Adhesion was partially blocked by monoclonal antibodies (mAb) specific for lymphocyte function-associated antigen 1 (LFA-1) and very late antigen 4 (VLA-4) on T cells and ICAM-1 and VCAM-1 on ASM cells. The observed integrin-independent adhesion was mediated by CD44/hyaluronate interactions as it was inhibited by anti-CD44 mAb 5F12 and by hyaluronidase. Furthermore, the adhesion of activated T lymphocytes induced DNA synthesis in growth-arrested ASM cells. Thus, the interaction between T cells and ASM may provide insight into the mechanisms that induce bronchial inflammation and possibly ASM cell hyperplasia seen in asthma. PMID:7520473

  3. In vitro differentiation of porcine aortic vascular precursor cells to endothelial and vascular smooth muscle cells.

    PubMed

    Zaniboni, Andrea; Bernardini, Chiara; Bertocchi, Martina; Zannoni, Augusta; Bianchi, Francesca; Avallone, Giancarlo; Mangano, Chiara; Sarli, Giuseppe; Calzà, Laura; Bacci, Maria Laura; Forni, Monica

    2015-09-01

    Recent findings suggest that progenitor and multipotent mesenchymal stromal cells (MSCs) are associated with vascular niches. Cells displaying mesenchymal properties and differentiating to whole components of a functional blood vessel, including endothelial and smooth muscle cells, can be defined as vascular stem cells (VSCs). Recently, we isolated a population of porcine aortic vascular precursor cells (pAVPCs), which have MSC- and pericyte-like properties. The aim of the present work was to investigate whether pAVPCs possess VSC-like properties and assess their differentiation potential toward endothelial and smooth muscle lineages. pAVPCs, maintained in a specific pericyte growth medium, were cultured in high-glucose DMEM + 10% FBS (long-term medium, LTM) or in human endothelial serum-free medium + 5% FBS and 50 ng/ml of hVEGF (endothelial differentiation medium, EDM). After 21 days of culture in LTM, pAVPCs showed an elongated fibroblast-like morphology, and they seem to organize in cord-like structures. qPCR analysis of smooth muscle markers [α-smooth muscle actin (α-SMA), calponin, and smooth muscle myosin (SMM) heavy chain] showed a significant increment of the transcripts, and immunofluorescence analysis confirmed the presence of α-SMA and SMM proteins. After 21 days of culture in EDM, pAVPCs displayed an endothelial cell-like morphology and revealed the upregulation of the expression of endothelial markers (CD31, vascular endothelial-cadherin, von Willebrand factor, and endothelial nitric oxide synthase) showing the CD31-typical pattern. In conclusion, pAVPCs could be defined as a VSC-like population considering that, if they are maintained in a specific pericyte medium, they express MSC markers, and they have, in addition to the classical mesenchymal trilineage differentiation potential, the capacity to differentiate in vitro toward the smooth muscle and the endothelial cell phenotypes.

  4. Myocardin Regulates Vascular Smooth Muscle Cell Inflammatory Activation and Disease

    PubMed Central

    Ackers-Johnson, Matthew; Talasila, Amarnath; Sage, Andrew P; Long, Xiaochun; Bot, Ilze; Morrell, Nicholas W; Bennett, Martin R; Miano, Joseph M.; Sinha, Sanjay

    2015-01-01

    Objective Atherosclerosis, the cause of 50% of deaths in westernised societies, is widely regarded as a chronic vascular inflammatory disease. Vascular smooth muscle cell (VSMC) inflammatory activation in response to local pro-inflammatory stimuli contributes to disease progression and is a pervasive feature in developing atherosclerotic plaques. Therefore, it is of considerable therapeutic importance to identify mechanisms that regulate the VSMC inflammatory response. Approach and Results We report that myocardin, a powerful myogenic transcriptional coactivator, negatively regulates VSMC inflammatory activation and vascular disease. Myocardin levels are reduced during atherosclerosis, in association with phenotypic switching of smooth muscle cells. Myocardin deficiency accelerates atherogenesis in hypercholesterolemic ApoE−/− mice. Conversely, increased myocardin expression potently abrogates the induction of an array of inflammatory cytokines, chemokines and adhesion molecules in VSMCs. Expression of myocardin in VSMCs reduces lipid uptake, macrophage interaction, chemotaxis and macrophage-endothelial tethering in vitro, and attenuates monocyte accumulation within developing lesions in vivo. These results demonstrate that endogenous levels of myocardin are a critical regulator of vessel inflammation. Conclusions We propose myocardin as a guardian of the contractile, non-inflammatory VSMC phenotype, with loss of myocardin representing a critical permissive step in the process of phenotypic transition and inflammatory activation, at the onset of vascular disease. PMID:25614278

  5. P38 MAPK signaling underlies a cell autonomous loss of stem cell self-renewal in aged skeletal muscle

    PubMed Central

    Bernet, Jennifer D.; Doles, Jason D.; Hall, John K.; Kelly-Tanaka, Kathleen; Carter, Thomas A.; Olwin, Bradley B.

    2014-01-01

    Skeletal muscle aging results in a gradual loss of skeletal muscle mass, skeletal muscle function and decreased regenerative capacity, which can lead to sarcopenia and increased mortality. While the mechanisms underlying sarcopenia remain unclear, the skeletal muscle stem cell, or satellite cell, is required for muscle regeneration. Therefore, identification of signaling pathways affecting satellite cell function during aging may provide insights into therapeutic targets for combating sarcopenia. Here, we show that a cell-autonomous loss in self-renewal occurs via alterations in FGF Receptor 1 and p38αβ MAPK signaling in aged satellite cells. We further demonstrate that pharmacological manipulation of these pathways can ameliorate age-associated self-renewal defects. Thus, our data highlight an age-associated deregulation of a satellite cell homeostatic network and reveal potential therapeutic opportunities for the treatment of progressive muscle wasting. PMID:24531379

  6. Contraction of gut smooth muscle cells assessed by fluorescence imaging.

    PubMed

    Tokita, Yohei; Akiho, Hirotada; Nakamura, Kazuhiko; Ihara, Eikichi; Yamamoto, Masahiro

    2015-03-01

    Here we discuss the development of a novel cell imaging system for the evaluation of smooth muscle cell (SMC) contraction. SMCs were isolated from the circular and longitudinal muscular layers of mouse small intestine by enzymatic digestion. SMCs were stimulated by test agents, thereafter fixed in acrolein. Actin in fixed SMCs was stained with phalloidin and cell length was determined by measuring diameter at the large end of phalloidin-stained strings within the cells. The contractile response was taken as the decrease in the average length of a population of stimulated-SMCs. Various mediators and chemically identified compounds of daikenchuto (DKT), pharmaceutical-grade traditional Japanese prokinetics, were examined. Verification of the integrity of SMC morphology by phalloidin and DAPI staining and semi-automatic measurement of cell length using an imaging analyzer was a reliable method by which to quantify the contractile response. Serotonin, substance P, prostaglandin E2 and histamine induced SMC contraction in concentration-dependent manner. Two components of DKT, hydroxy-α-sanshool and hydroxy-β-sanshool, induced contraction of SMCs. We established a novel cell imaging technique to evaluate SMC contractility. This method may facilitate investigation into SMC activity and its role in gastrointestinal motility, and may assist in the discovery of new prokinetic agents. PMID:25837933

  7. Normal myogenic cells from newborn mice restore normal histology to degenerating muscles of the mdx mouse

    SciTech Connect

    Morgan, J.E.; Hoffman, E.P.; Partridge, T.A. )

    1990-12-01

    Dystrophin deficiency in skeletal muscle of the x-linked dystrophic (mdx) mouse can be partially remedied by implantation of normal muscle precursor cells (mpc). However, it is difficult to determine whether this biochemical rescue results in any improvement in the structure or function of the treated muscle, because the vigorous regeneration of mdx muscle more than compensates for the degeneration. By using x-ray irradiation to prevent mpc proliferation, it is possible to study loss of mdx muscle fibers without the complicating effect of simultaneous fiber regeneration. Thus, improvements in fiber survival resulting from any potential therapy can be detected easily. Here, we have implanted normal mpc, obtained from newborn mice, into such preirradiated mdx muscles, finding that it is far more extensively permeated and replaced by implanted mpc than is nonirradiated mdx muscle; this is evident both from analysis of glucose-6-phosphate isomerase isoenzyme markers and from immunoblots and immunostaining of dystrophin in the treated muscles. Incorporation of normal mpc markedly reduces the loss of muscle fibers and the deterioration of muscle structure which otherwise occurs in irradiated mdx muscles. Surprisingly, the regenerated fibers are largely peripherally nucleated, whereas regenerated mouse skeletal muscle fibers are normally centrally nucleated. We attribute this regeneration of apparently normal muscle to the tendency of newborn mouse mpc to recapitulate their neonatal ontogeny, even when grafted into 3-wk-old degenerating muscle.

  8. How Is Heart Failure Diagnosed?

    MedlinePlus

    ... in a pocket, or hung around your neck. Nuclear Heart Scan A nuclear heart scan shows how well blood is flowing ... blood is reaching your heart muscle. During a nuclear heart scan, a safe, radioactive substance called a ...

  9. Bioengineering and Stem Cell Technology in the Treatment of Congenital Heart Disease

    PubMed Central

    Bosman, Alexis; Edel, Michael J.; Blue, Gillian; Dilley, Rodney J.; Harvey, Richard P.; Winlaw, David S.

    2015-01-01

    Congenital heart disease places a significant burden on the individual, family and community despite significant advances in our understanding of aetiology and treatment. Early research in ischaemic heart disease has paved the way for stem cell technology and bioengineering, which promises to improve both structural and functional aspects of disease. Stem cell therapy has demonstrated significant improvements in cardiac function in adults with ischaemic heart disease. This finding, together with promising case studies in the paediatric setting, demonstrates the potential for this treatment in congenital heart disease. Furthermore, induced pluripotent stems cell technology, provides a unique opportunity to address aetiological, as well as therapeutic, aspects of disease. PMID:26239354

  10. Circovirus inclusion bodies in intestinal muscle cells of a canary.

    PubMed

    Rampin, T; Manarolla, G; Pisoni, G; Recordati, C; Sironi, G

    2006-08-01

    Multiple cytoplasmic inclusion bodies were observed in the intestinal smooth muscle cells of an adult canary from an aviary with a history of high mortality (50%) both in adult and young birds. Grossly, a mild enteritis was the only lesion appreciable. Smears of the proventricular contents contained a few megabacteria (Macrorhabdus ornithogaster). The intestinal inclusions were found in very high numbers in all parts of the tract examined. They appeared round to oval, amphophilic and hyaline in sections stained with haematoxylin and eosin, and magenta with Feulgen stain. Inclusions of the same type were occasionally detectable in the wall of a few splenic and pancreatic arteries. No inclusions or lesions were seen in the other organs examined. Transmission electron microscopy of the intestinal wall revealed circovirus-like particles either in paracrystalline arrays or loose arrangements, mostly within the cytoplasm of the intestinal muscule cells. Polymerase chain reaction amplification and sequence analysis confirmed infection with canary circovirus.

  11. Simulated Hypergravity Alters Vascular Smooth Muscle Cell Proliferation and Motility

    NASA Technical Reports Server (NTRS)

    Hunt, Shameka; Bettis, Barika; Harris-Hooker, Sandra; Sanford, Gary L.

    1997-01-01

    The cellular effects of gravity are poorly understood due to its constancy and nonavailability of altered gravitational models. Such an understanding is crucial for prolonged space flights. In these studies, we assessed the influence of centrifugation at 6G (HGrav) on vascular smooth muscle (SMC) mobility and proliferation. Cells were: (a) plated at low density and subjected to HGrav for 24-72 hr for proliferation studies, or (b) grown to confluency, subjected to HGrav, mechanically denuded and monitored for cell movement into the denuded area. Controls were maintained under normogravity. SMC showed a 50% inhibition of growth under HGrav and 10% serum; HGrav and low serum resulted in greater growth inhibition. The rate of movement of SMC into the denuded area was 2-3-fold higher under HGrav in low serum compared to controls, but similar in 10% serum. These studies show that HGrav has significant effects on SMC growth and mobility, which are dependent on serum levels.

  12. Creatine kinase in non-muscle tissues and cells.

    PubMed

    Wallimann, T; Hemmer, W

    1994-01-01

    Over the past years, a concept for creatine kinase function, the 'PCr-circuit' model, has evolved. Based on this concept, multiple functions for the CK/PCr-system have been proposed, such as an energy buffering function, regulatory functions, as well as an energy transport function, mostly based on studies with muscle. While the temporal energy buffering and metabolic regulatory roles of CK are widely accepted, the spatial buffering or energy transport function, that is, the shuttling of PCr and Cr between sites of energy utilization and energy demand, is still being debated. There is, however, much circumstantial evidence, that supports the latter role of CK including the distinct, isoenzyme-specific subcellular localization of CK isoenzymes, the isolation and characterization of functionally coupled in vitro microcompartments of CK with a variety of cellular ATPases, and the observed functional coupling of mitochondrial oxidative phosphorylation with mitochondrial CK. New insight concerning the functions of the CK/PCr-system has been gained from recent M-CK null-mutant transgenic mice and by the investigation of CK localization and function in certain highly specialized non-muscle tissues and cells, such as electrocytes, retina photoreceptor cells, brain cells, kidney, salt glands, myometrium, placenta, pancreas, thymus, thyroid, intestinal brush-border epithelial cells, endothelial cells, cartilage and bone cells, macrophages, blood platelets, tumor and cancer cells. Studies with electric organ, including in vivo 31P-NMR, clearly reveal the buffer function of the CK/PCr-system in electrocytes and additionally corroborate a direct functional coupling of membrane-bound CK to the Na+/K(+)-ATPase. On the other hand, experiments with live sperm and recent in vivo 31P-NMR measurements on brain provide convincing evidence for the transport function of the CK/PCr-system. We report on new findings concerning the isoenzyme-specific cellular localization and subcellular

  13. Stem Cells and Progenitor Cells for Tissue-Engineered Solutions to Congenital Heart Defects

    PubMed Central

    Gao, Yang; Jacot, Jeffrey G

    2015-01-01

    Synthetic patches and fixed grafts currently used in the repair of congenital heart defects are nonliving, noncontractile, and not electrically responsive, leading to increased risk of complication, reoperation, and sudden cardiac death. Studies suggest that tissue-engineered patches made from living, functional cells could grow with the patient, facilitate healing, and help recover cardiac function. In this paper, we review the research into possible sources of cardiomyocytes and other cardiac cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, adipose-derived stem cells, umbilical cord blood cells, amniotic fluid-derived stem cells, and cardiac progenitor cells. Each cell source has advantages, but also has technical hurdles to overcome, including heterogeneity, functional maturity, immunogenicity, and pathogenicity. Additionally, biomaterials used as patch materials will need to attract and support desired cells and induce minimal immune responses. PMID:26379417

  14. Stem Cells and Progenitor Cells for Tissue-Engineered Solutions to Congenital Heart Defects.

    PubMed

    Gao, Yang; Jacot, Jeffrey G

    2015-01-01

    Synthetic patches and fixed grafts currently used in the repair of congenital heart defects are nonliving, noncontractile, and not electrically responsive, leading to increased risk of complication, reoperation, and sudden cardiac death. Studies suggest that tissue-engineered patches made from living, functional cells could grow with the patient, facilitate healing, and help recover cardiac function. In this paper, we review the research into possible sources of cardiomyocytes and other cardiac cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, adipose-derived stem cells, umbilical cord blood cells, amniotic fluid-derived stem cells, and cardiac progenitor cells. Each cell source has advantages, but also has technical hurdles to overcome, including heterogeneity, functional maturity, immunogenicity, and pathogenicity. Additionally, biomaterials used as patch materials will need to attract and support desired cells and induce minimal immune responses. PMID:26379417

  15. (Na) sub i modulates isoproterenol's effect on Ca permeability in cultured heart cells

    SciTech Connect

    Kim, D.; Smith, T.W. )

    1987-08-01

    Isoproterenol (ISO) augments the slow inward Ca current in cardiac muscle cells. The authors examined the role of intracellular Na (Na{sub i}) on ISO-mediated alterations in Ca uptake in cultured chick heart cells. In 140 mM Na medium, 1 {mu}M ISO did not measurably alter {sup 45}Ca uptake. When cells were first preincubated in Na-free medium for 5 min and then incubated in control medium with {sup 45}Ca, ISO increased {sup 45}Ca uptake by 30%. Nifedipine, verapamil, or dl-propranolol abolished the effect of ISO on {sup 45}Ca uptake. CGP 28392, a Ca channel agonist, increased Ca influx in a manner that was augmented by decreased Na{sub i}, similar to the ISO response. Neither ISO nor CGP 28392 altered {sup 45}Ca uptake when cells preincubated in Na-free medium were further incubated in Na-free medium containing {sup 45}Ca. Exposure of cells to Na-free medium or 25 mM K{sup +} medium caused depolarization of the resting membrane potential to approximately {minus}40 mV. In the absence of ISO, the {sup 45}Ca uptake in cells preincubated in Na-free or 25 mM extracellular K (K{sub o}) medium was significantly greater than in cells preincubated in control medium. This appeared to be due partly to increased {sup 45}Ca uptake via nifedipine-sensitive pathways. These findings support the hypothesis that reduction in Na{sub i} concentration ((Na){sub i}) enhances the ISO-induced augmentation of Ca uptake via nifedipine-sensitive pathways (presumably via slow Ca channels), probably by a direct effect on the channels.

  16. Smooth muscle progenitor cells from peripheral blood promote the neovascularization of endothelial colony-forming cells

    SciTech Connect

    Joo, Hyung Joon; Seo, Ha-Rim; Jeong, Hyo Eun; Choi, Seung-Cheol; Park, Jae Hyung; Yu, Cheol Woong; Hong, Soon Jun; Chung, Seok; Lim, Do-Sun

    2014-07-11

    Highlights: • Two distinct vascular progenitor cells are induced from adult peripheral blood. • ECFCs induce vascular structures in vitro and in vivo. • SMPCs augment the in vitro and in vivo angiogenic potential of ECFCs. • Both cell types have synergistic therapeutic potential in ischemic hindlimb model. - Abstract: Proangiogenic cell therapy using autologous progenitors is a promising strategy for treating ischemic disease. Considering that neovascularization is a harmonized cellular process that involves both endothelial cells and vascular smooth muscle cells, peripheral blood-originating endothelial colony-forming cells (ECFCs) and smooth muscle progenitor cells (SMPCs), which are similar to mature endothelial cells and vascular smooth muscle cells, could be attractive cellular candidates to achieve therapeutic neovascularization. We successfully induced populations of two different vascular progenitor cells (ECFCs and SMPCs) from adult peripheral blood. Both progenitor cell types expressed endothelial-specific or smooth muscle-specific genes and markers, respectively. In a protein array focused on angiogenic cytokines, SMPCs demonstrated significantly higher expression of bFGF, EGF, TIMP2, ENA78, and TIMP1 compared to ECFCs. Conditioned medium from SMPCs and co-culture with SMPCs revealed that SMPCs promoted cell proliferation, migration, and the in vitro angiogenesis of ECFCs. Finally, co-transplantation of ECFCs and SMPCs induced robust in vivo neovascularization, as well as improved blood perfusion and tissue repair, in a mouse ischemic hindlimb model. Taken together, we have provided the first evidence of a cell therapy strategy for therapeutic neovascularization using two different types of autologous progenitors (ECFCs and SMPCs) derived from adult peripheral blood.

  17. Vascular smooth muscle cell spreading onto fibrinogen is regulated by calpains and phospholipase C.

    PubMed

    Paulhe, F; Bogyo, A; Chap, H; Perret, B; Racaud-Sultan, C

    2001-11-01

    Fibrinogen deposition and smooth muscle cell migration are important causes of atherosclerosis and angiogenesis. Involvement of calpains in vascular smooth muscle cell adhesion onto fibrinogen was investigated. Using calpain inhibitors, we showed that activation of calpains was required for smooth muscle cell spreading. An increase of (32)P-labeled phosphatidic acid and phosphatidylinositol-3,4-bisphosphate, respective products of phospholipase C and phosphoinositide 3-kinase activities, was measured in adherent cells. Addition of the calpain inhibitor calpeptin strongly decreased phosphatidic acid and phosphatidylinositol-3,4-bisphosphate. However, smooth muscle cell spreading was prevented by the phospholipase C inhibitor U-73122, but poorly modified by phosphoinositide 3-kinase inhibitors wortmannin and LY-294002. Moreover, PLC was found to act upstream of the PI 3-kinase IA isoform. Thus, our data provide the first evidence that calpains are required for smooth muscle cell spreading. Further, phospholipase C activation is pointed as a key step of cell-spreading regulation by calpains.

  18. Mechanisms of Cardiotoxicity and the Development of Heart Failure.

    PubMed

    Lee, Christopher S

    2015-12-01

    Cardiotoxicity is a broad term that refers to the negative effects of toxic substances on the heart. Cancer drugs can cause cardiotoxicity by effects on heart cells, thromboembolic events, and/or hypertension that can lead to heart failure. Rheumatoid arthritis biologics may interfere with ischemic preconditioning and cause/worsen heart failure. Long-term and heavy alcohol use can result in oxidative stress, apoptosis, and decreased contractile protein function. Cocaine use results in sympathetic nervous system stimulation of heart and smooth muscle cells and leads to cardiotoxicity and evolution of heart failure. The definition of cardiotoxicity is likely to evolve along with knowledge about detecting subclinical myocardial injury. PMID:26567492

  19. Monolayer co-culture of rat heart cells and bovine adrenal chromaffin paraneurons.

    PubMed

    Trifaró, J M; Tang, R; Novas, M L

    1990-04-01

    This paper describes a method for the preparation of co-cultures of rat heart cells and bovine adrenal chromaffin paraneurons. The most suitable condition for heart cell isolation was when a combination of trypsin-DNAse I in Locke's solution was used for digestion. The best co-culture conditions were obtained when 10(6) heart cells were plated on 7- to 8-d-old adrenal chromaffin paraneuron cultures containing 0.5 x 10(6) cells per 35-mm diameter culture dishes. Measurements of DNA (heart cells and chromaffin paraneurons), monitoring of beating frequency (heart cells), and catecholamine (chromaffin paraneurons) levels and release indicated that both cell types remain viable and functional for several weeks. Heart cells started their characteristic contractile activity 24 h earlier when plated either on viable or lysed chromaffin paraneurons, an effect apparently due to faster surface adhesion of heart cells. The beating frequency of heart cells increased after treatment of co-cultures with either noradrenaline or nicotine, with the latter agent acting indirectly through the release of chromaffin paraneuron catecholamines. Propranolol produced a dose-related inhibition of the responses to either noradrenaline or nicotine, thus suggesting that the increase in myocyte's beating activity was mediated through beta-receptors. Anti-myosin and anti-dopamine-beta-hydroxylase immunostaining was used for cell type identification and for the demonstration of body-to-body and process-to-process contacts between adrenal chromaffin paraneurons and heart cells. This co-culture system will serve as a starting point of further studies directed to understand a) the influence of a cell type on the development and on the phenotypic characteristics of a second cell type and b) the interaction of cells derived from different organs and species.

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

    PubMed

    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.

  1. Transcriptional regulation of cytokine function in airway smooth muscle cells

    PubMed Central

    Clarke, Deborah; Damera, Gautam; Sukkar, Maria B.; Tliba, Omar

    2009-01-01

    The immuno-modulatory properties of airway smooth muscle have become of increasing importance in our understanding of the mechanisms underlying chronic inflammation and structural remodeling of the airway wall in asthma and chronic obstructive pulmonary disease (COPD). ASM cells respond to many cytokines, growth factors and lipid mediators to produce a wide array of immuno-modulatory molecules which may in turn orchestrate and perpetuate the disease process in asthma and COPD. Despite numerous studies of the cellular effects of cytokines on cultured ASM, few have identified intracellular signaling pathways by which cytokines modulate or induce these cellular responses. In this review we provide an overview of the transcriptional mechanisms as well as intracellular signaling pathways regulating cytokine functions in ASM cells. The recent discovery of toll-like receptors in ASM cells represents a significant development in our understanding of the immuno-modulatory capabilities of ASM cells. Thus, we also review emerging evidence of the inflammatory response to toll-like receptor activation in ASM cells. PMID:19393330

  2. Building A New Treatment For Heart Failure-Transplantation of Induced Pluripotent Stem Cell-derived Cells into the Heart

    PubMed Central

    Miyagawa, Shigeru; Fukushima, Satsuki; Imanishi, Yukiko; Kawamura, Takuji; Mochizuki-Oda, Noriko; Masuda, Shigeo; Sawa, Yoshiki

    2016-01-01

    Advanced cardiac failure is a progressive intractable disease and is the main cause of mortality and morbidity worldwide. Since this pathology is represented by a definite decrease in cardiomyocyte number, supplementation of functional cardiomyocytes into the heart would hypothetically be an ideal therapeutic option. Recently, unlimited in vitro production of human functional cardiomyocytes was established by using induced pluripotent stem cell (iPSC) technology, which avoids the use of human embryos. A number of basic studies including ours have shown that transplantation of iPSC-derived cardiomyocytes (iPSC-CMs) into the damaged heart leads to recovery of cardiac function, thereby establishing “proof-of-concept” of this iPSC-transplantation therapy. However, considering clinical application of this therapy, its feasibility, safety, and therapeutic efficacy need to be further investigated in the pre-clinical stage. This review summarizes up-to-date important topics related to safety and efficacy of iPSC-CMs transplantation therapy for cardiac disease and discusses the prospects for this treatment in clinical studies.

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

    PubMed Central

    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

  4. Carvacrol induces the apoptosis of pulmonary artery smooth muscle cells under hypoxia.

    PubMed

    Zhang, Qianlong; Fan, Kai; Wang, Peng; Yu, Juan; Liu, Ruxia; Qi, Hanping; Sun, Hongli; Cao, Yonggang

    2016-01-01

    The abnormal apoptosis of pulmonary artery smooth muscle cells (PASMCs) is an important pathophysiological process in pulmonary vascular remodeling and pulmonary arterial hypertension (PAH). Carvacrol, an essential oil compound from oregano and thyme, has displayed antimicrobial, antitumor, and antioxidant properties. Although carvacrol has pro-apoptosis properties in tumor cells, the underlying mechanisms of carvacrol in PASMC apoptosis remain unclear. Thus, in this study, we aim to investigate the role of carvacrol in pulmonary vascular remodeling and PASMC apoptosis in hypoxia. Right Ventricular Hypertrophy Measurements and pulmonary pathomorphology data show that the ratio of the heart weight/tibia length (HW/TL), the right ventricle/left ventricle plus septum (RV/LV+S) and the medial width of the pulmonary artery increased in chronic hypoxia and were reversed by carvacrol treatment under hypoxia. Additionally, carvacrol inhibited PASMC viability, attenuated oxidative stress, induced mitochondria membrane depolarization, increased the percentage of apoptotic cells, suppressed Bcl-2 expression, decreased procaspase-3 expression, promoted caspase-3 activation, and inhibited the ERK1/2 and PI3K/Akt pathway. Taken together, these findings suggest that carvacrol attenuates the pulmonary vascular remodeling and promotes PASMC apoptosis by acting on, at least in part, the intrinsic apoptotic pathway. This process might provide us new insight into the development of hypoxic pulmonary hypertension. PMID:26607464

  5. Regulation of troponin C synthesis in primary culture of chicken cardiac muscle cells.

    PubMed

    Malhotra, S B; Bag, J

    1987-01-01

    Cardiac myocyte cell culture from fourteen day old embryonic chicken heart was prepared. This cultured cell system was used to examine the regulation of troponin C (TnC) synthesis in cardiac muscle. To examine the regulation of TnC polypeptide synthesis, cardiac myocyte cells were pulse labelled with 35S-methionine at different days after plating. The synthesis of TnC was measured by determining the amount of radioactivity incorporated into the TnC polypeptide following separation by two dimensional gel electrophoresis. These measurements showed that TnC synthesis was maximum in 36 to 48 h old cultures and reached its lowest level in 4 day old cultures. This was in contrast to the synthesis of actin and tropomyosin. Synthesis of these polypeptides were lowest in 36 to 48 h old cultures and was maximum in 7 day old cultures. To examine whether the synthesis of TnC polypeptide paralleled the levels of TnC mRNA the sequences homologous to quail slow TnC cDNA clone were measured by hybridisation. The results showed that the decrease in the synthesis of troponin C polypeptide cannot be fully explained by the decrease in the steady state level of troponin C mRNA. The possibility of a role of translational control of troponin C mRNA in this process is discussed. PMID:2890096

  6. Fate of 3H-thymidine labelled myogenic cells in regeneration of muscle isografts.

    PubMed

    Gutmann, E; Mares, V; Stichová, J

    1976-03-01

    Intact and denervated extensor digitorum longus (EDL) muscles of 20-day-old inbred Lewis-Wistar rats were labelled with 3H-thymidine. Ninety minutes after the injection of the isotope 4.0% of the nuclei were labelled in the intact (i.e. innervated) and 9.6% in the muscles, denervated 3 days before administration of the isotope. The labelled EDL muscles were grafted into the bed of the previously removed EDL muscles of inbred animals and these isografts were studied 30 days later. In the EDL muscles, regenerated from innervated isografts only occasionally labelled endothelial cells were found whereas in the muscles regenerated from denervated isografts also parenchymal muscle nuclei were regularly labelled. The incidence of labelled nuclei in the regenerated EDL muscles was, however, about 20 times lower than in the donor EDL muscles. The presen experiments provide a direct proof of utilization of donor satelite cell nuclei for regeneration in grafted muscle tissue. With respect to the low incidence of labelled nuclei in regenerated EDL muscles, other sources of cells apparently also contribute to the regeneration process.

  7. Pericytes: multitasking cells in the regeneration of injured, diseased, and aged skeletal muscle.

    PubMed

    Birbrair, Alexander; Zhang, Tan; Wang, Zhong-Min; Messi, Maria L; Mintz, Akiva; Delbono, Osvaldo

    2014-01-01

    Pericytes are perivascular cells that envelop and make intimate connections with adjacent capillary endothelial cells. Recent studies show that they may have a profound impact in skeletal muscle regeneration, innervation, vessel formation, fibrosis, fat accumulation, and ectopic bone formation throughout life. In this review, we summarize and evaluate recent advances in our understanding of pericytes' influence on adult skeletal muscle pathophysiology. We also discuss how further elucidating their biology may offer new approaches to the treatment of conditions characterized by muscle wasting.

  8. Original Research: Combined model of bladder detrusor smooth muscle and interstitial cells.

    PubMed

    Rosenberg, Josef; Byrtus, Miroslav; Stengl, Milan

    2016-10-01

    Although patients with lower urinary tract symptoms constitute a large and still growing population, understanding of bladder detrusor muscle physiology remains limited. Understanding the interactions between the detrusor smooth muscle cells and other bladder cell types (e.g. interstitial cells, IC) that may significantly contribute to coordinating and modulating detrusor contractions represents a considerable challenge. Computer modeling could help to elucidate some properties that are difficult to address experimentally; therefore, we developed in silico models of detrusor smooth muscle cell and interstitial cells, coupled through gap junctions. The models include all of the major ion conductances and transporters described in smooth muscle cell and interstitial cells in the literature. The model of normal detrusor muscle (smooth muscle cell and interstitial cells coupled through gap junctions) completely reproduced the experimental results obtained with detrusor strips in the presence of several pharmacological interventions (ryanodine, caffeine, nimodipine), whereas the model of smooth muscle cell alone (without interstitial cells) failed to reproduce the experimental results. Next, a model of overactive bladder, a highly prevalent clinical condition in both men and women with increasing incidence at older ages, was produced by modifying several processes as reported previously: a reduction of Ca(2+)-release through ryanodine receptors and a reduction of Ca(2+)-dependent K(+)-conductance with augmented gap junctional coupling. This model was also able to reproduce the pharmacological modulation of overactive bladder. In conclusion, a model of bladder detrusor muscle was developed that reproduced experimental results obtained in both normal and overactive bladder preparations. The results indicate that the non-smooth muscle cells of the detrusor (interstitial cells) contribute significantly to the contractile behavior of bladder detrusor muscle and should not be

  9. Electrical stimulation of skeletal muscles. An alternative to aerobic exercise training in patients with chronic heart failure?

    PubMed

    Dobsák, Petr; Nováková, Marie; Fiser, Bohumil; Siegelová, Jarmila; Balcárková, Pavla; Spinarová, Lenka; Vítovec, Jirí; Minami, Naoyoshi; Nagasaka, Makoto; Kohzuki, Masahiro; Yambe, Tomoyuki; Imachi, Kou; Nitta, Shin-ichi; Eicher, Jean-Christophe; Wolf, Jean-Eric

    2006-05-01

    The aim of this study was to investigate whether electrical stimulation of skeletal muscles could represent a rehabilitation alternative for patients with chronic heart failure (CHF). Thirty patients with CHF and NYHA class II-III were randomly assigned to a rehabilitation program using either electrical stimulation of skeletal muscles or bicycle training. Patients in the first group (n = 15) had 8 weeks of home-based low-frequency electrical stimulation (LFES) applied simultaneously to the quadriceps and calf muscles of both legs (1 h/day for 7 days/week); patients in the second group (n = 15) underwent 8 weeks of 40 minute aerobic exercise (3 times a week). After the 8-week period significant increases in several functional parameters were observed in both groups: maximal VO2 uptake (LFES group: from 17.5 +/- 4.4 mL/kg/min to 18.3 +/- 4.2 mL/kg/min, P < 0.05; bicycle group: from 18.1 +/- 3.9 mL/kg/min to 19.3 +/- 4.1 mL/kg/min, P < 0.01), maximal workload (LFES group: from 84.3 +/- 15.2 W to 95.9 +/- 9.8 W, P < 0.05; bicycle group: from 91.2 +/- 13.4 W to 112.9 +/- 10.8 W, P < 0.01), distance walked in 6 minutes (LFES group: from 398 +/- 105 m to 435 +/- 112 m, P < 0.05; bicycle group: from 425 +/- 118 m to 483 +/- 120 m, P < 0.03), and exercise duration (LFES group: from 488 +/- 45 seconds to 568 +/- 120 seconds, P < 0.05; bicycle group: from 510 +/- 90 seconds to 611 +/- 112 seconds, P < 0.03). These results demonstrate that an improvement of exercise capacities can be achieved either by classical exercise training or by home-based electrical stimulation. LFES should be considered as a valuable alternative to classical exercise training in patients with CHF.

  10. Influence of menstrual cycle phase on muscle metaboreflex control of cardiac baroreflex sensitivity, heart rate and blood pressure in humans.

    PubMed

    Hartwich, Doreen; Aldred, Sarah; Fisher, James P

    2013-01-01

    We sought to determine whether menstrual cycle phase influences muscle metaboreflex control of spontaneous cardiac baroreflex sensitivity (cBRS), blood pressure (BP) and heart rate (HR). Twenty-three young women not taking oral contraceptives were studied during the early (EF; low oestrogen, low progesterone) and late follicular menstrual phases (LF; high oestrogen, low progesterone). Protocol 1 consisted of leg cycling at low (21 ± 2 W) and moderate workloads (71 ± 3 W) in free-flow conditions and with partial flow restriction (bilateral thigh-cuff inflation at 100 mmHg) to activate the muscle metaboreflex. Protocol 2 consisted of rhythmic hand-grip exercise with incremental upper arm-cuff inflation (0, 80, 100 and 120 mmHg) to elicit graded metaboreflex activation. Both protocols were followed by post-exercise ischaemia. Leg cycling decreased cBRS (EF, 20 ± 5, 6 ± 1 and 1 ± 0.1 ms mmHg(-1); and LF, 19 ± 3, 6 ± 0.4, 1 ± 0.1 ms mmHg(-1) during rest, low- and moderate-intensity leg cycling, respectively) and increased HR in an intensity-dependent manner, while BP remained unchanged. Partial flow restriction during leg cycling decreased cBRS, and increased HR and BP. During post-exercise ischaemia, HR and BP remained elevated, while cBRS remained suppressed (EF, 4.2 ± 0.6 ms mmHg(-1); and LF, 4.7 ± 0.5 ms mmHg(-1); P < 0.05 versus rest). Cardiac baroreflex sensitivity was unchanged during hand-grip with and without partial flow restriction and post-exercise ischaemia. No differences in cBRS, HR or BP responses were observed between EF and LF at any time during either protocol. These data indicate that endogenous fluctuations in oestrogen between the EF and LF phases of the menstrual cycle do not influence muscle metaboreflex control of cBRS, BP or HR in young women.

  11. The effects of heart rate on the action potential of guinea-pig and human ventricular muscle.

    PubMed

    Attwell, D; Cohen, I; Eisner, D A

    1981-01-01

    1. On increasing the stimulation frequency of isolated pieces of guinea-pig ventricular muscle, the resting potential depolarizes, and the action potential duration and amplitude are reduced. On termination of the high frequency train of action potentials, these changes are reversed. 2. The resting potential changes are roughly exponential, with a time constant of the order of 10 sec, and are attributable to K+ accumulation in the extracellular space. They are not explicable in terms of known gating variables. 3. The action potential duration and amplitude recover much more slowly than the resting potential, after a high frequency train (half-time approximately 5 min). The time course of these recoveries is not exponential, and is slower after trains which produce more shortening of the action potential. The slow time course suggests that K+ accumulation is not the main cause of the changes in action potential shape. Furthermore, when a certain depolarization of the resting potential is produced by a high frequency train, there is a greater reduction of the action potential duration than that which occurs when the bathing [K+] is raised to produce the same depolarization (Reiter & Stickel, 1968). This is so even when a gradient of extracellular [K+] is induced in the preparation, to mimic non-uniform K+ accumulation. 4. Similarly, the shortening of the action potential produced by toxic doses or cardiotonic steroids is probably not the result of K+ accumulation. 5. The slow changes of the action potential shape produced by a high frequency train are not attributable to the effects of gating variables, nor (solely) to a rise in the intracellular Na concentration stimulating the electrogenic Na/K pump. The dye 3,3'-diethylthiadicarbocyanine, which blocks the Ca2+-activated K conductance in the erythrocyte, has no significant effect on the shape changes. 6. After a sudden change in heart rate, the QT interval of the human electrocardiogram (e.c.g.) changes slowly to a

  12. Extracellular calcium sensing in rat aortic vascular smooth muscle cells

    SciTech Connect

    Smajilovic, Sanela; Hansen, Jakob Lerche; Christoffersen, Tue E.H.

    2006-10-06

    Extracellular calcium (Ca2+o) can act as a first messenger in many cell types through a G protein-coupled receptor, calcium-sensing receptor (CaR). It is still debated whether the CaR is expressed in vascular smooth muscle cells (VSMCs). Here, we report the expression of CaR mRNA and protein in rat aortic VSMCs and show that Ca2+o stimulates proliferation of the cells. The effects of Ca2+o were attenuated by pre-treatment with MAPK kinase 1 (MEK1) inhibitor, as well as an allosteric modulator, NPS 2390. Furthermore, stimulation of the VSMCs with Ca2+o-induced phosphorylation of ERK1/2, but surprisingly did not cause inositol phosphate accumulation. We were not able to conclusively state that the CaR mediates Ca2+o-induced cell proliferation. Rather, an additional calcium-sensing mechanism may exist. Our findings may be of importance with regard to atherosclerosis, an inflammatory disease characterized by abnormal proliferation of VSMCs and high local levels of calcium.

  13. Decorin binds myostatin and modulates its activity to muscle cells

    SciTech Connect

    Miura, Takayuki; Kishioka, Yasuhiro; Wakamatsu, Jun-ichi; Hattori, Akihito; Hennebry, Alex; Berry, Carole J.; Sharma, Mridula; Kambadur, Ravi; Nishimura, Takanori . E-mail: nishi@anim.agr.hokudai.ac.jp

    2006-02-10

    Myostatin, a member of TGF-{beta} superfamily of growth factors, acts as a negative regulator of skeletal muscle mass. The mechanism whereby myostatin controls the proliferation and differentiation of myogenic cells is mostly clarified. However, the regulation of myostatin activity to myogenic cells after its secretion in the extracellular matrix (ECM) is still unknown. Decorin, a small leucine-rich proteoglycan, binds TGF-{beta} and regulates its activity in the ECM. Thus, we hypothesized that decorin could also bind to myostatin and participate in modulation of its activity to myogenic cells. In order to test the hypothesis, we investigated the interaction between myostatin and decorin by surface plasmon assay. Decorin interacted with mature myostatin in the presence of concentrations of Zn{sup 2+} greater than 10 {mu}M, but not in the absence of Zn{sup 2+}. Kinetic analysis with a 1:1 binding model resulted in dissociation constants (K {sub D}) of 2.02 x 10{sup -8} M and 9.36 x 10{sup -9} M for decorin and the core protein of decorin, respectively. Removal of the glycosaminoglycan chain by chondroitinase ABC digestion did not affect binding, suggesting that decorin could bind to myostatin with its core protein. Furthermore, we demonstrated that immobilized decorin could rescue the inhibitory effect of myostatin on myoblast proliferation in vitro. These results suggest that decorin could trap myostatin and modulate its activity to myogenic cells in the ECM.

  14. Functional dysregulation of stem cells during aging: a focus on skeletal muscle stem cells.

    PubMed

    García-Prat, Laura; Sousa-Victor, Pedro; Muñoz-Cánoves, Pura

    2013-09-01

    Aging of an organism is associated with the functional decline of tissues and organs, as well as a sharp decline in the regenerative capacity of stem cells. A prevailing view holds that the aging rate of an individual depends on the ratio of tissue attrition to tissue regeneration. Therefore, manipulations that favor the balance towards regeneration may prevent or delay aging. Skeletal muscle is a specialized tissue composed of postmitotic myofibers that contract to generate force. Satellite cells are the adult stem cells responsible for skeletal muscle regeneration. Recent studies on the biology of skeletal muscle and satellite cells in aging have uncovered the critical impact of systemic and niche factors on stem cell functionality and demonstrated the capacity of aged satellite cells to rejuvenate and increase their regenerative potential when exposed to a youthful environment. Here we review the current literature on the coordinated relationship between cell extrinsic and intrinsic factors that regulate the function of satellite cells, and ultimately determine tissue homeostasis and repair during aging, and which encourage the search for new anti-aging strategies.

  15. Genetic complementation of human muscle cells via directed stem cell fusion.

    PubMed

    Gonçalves, Manuel A F V; Swildens, Jim; Holkers, Maarten; Narain, Anjali; van Nierop, Gijsbert P; van de Watering, Marloes J M; Knaän-Shanzer, Shoshan; de Vries, Antoine A F

    2008-04-01

    Duchenne muscular dystrophy (DMD) is caused by mutations in the X chromosome-linked DMD gene, which encodes the sarcolemma-stabilizing protein-dystrophin. Initial attempts at DMD therapy deployed muscle progenitor cells from healthy donors. The utilization of these cells is, however, hampered by their immunogenicity, while those from DMD patients are scarce and display limited ex vivo replication. Nonmuscle cells with myogenic capacity may offer valuable alternatives especially if, to allow autologous transplantation, they are amenable to genetic intervention. As a paradigm for therapeutic gene transfer by heterotypic cell fusion we are investigating whether human mesenchymal stem cells (hMSCs) can serve as donors of recombinant DMD genes for recipient human muscle cells. Here, we show that forced MyoD expression in hMSCs greatly increases their tendency to participate in human myotube formation turning them into improved DNA delivery vehicles. Efficient loading of hMSCs with recombinant DMD was achieved through a new tropism-modified high-capacity adenoviral (hcAd) vector directing striated muscle-specific synthesis of full-length dystrophin. This study introduces the principle of genetic complementation of gene-defective cells via directed cell fusion and provides an initial framework to test whether transient MyoD synthesis in autologous, gene-corrected hMSCs increases their potential for treating DMD and, possibly, other muscular dystrophies.