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Sample records for heart muscle cells

  1. 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

  2. Concise Review: Skeletal Muscle Stem Cells and Cardiac Lineage: Potential for Heart Repair

    PubMed Central

    Hassan, Narmeen; Tchao, Jason

    2014-01-01

    Valuable and ample resources have been spent over the last two decades in pursuit of interventional strategies to treat the unmet demand of heart failure patients to restore myocardial structure and function. At present, it is clear that full restoration of myocardial structure and function is outside our reach from both clinical and basic research studies, but it may be achievable with a combination of ongoing research, creativity, and perseverance. Since the 1990s, skeletal myoblasts have been extensively investigated for cardiac cell therapy of congestive heart failure. Whereas the Myoblast Autologous Grafting in Ischemic Cardiomyopathy (MAGIC) trial revealed that transplanted skeletal myoblasts did not integrate into the host myocardium and also did not transdifferentiate into cardiomyocytes despite some beneficial effects on recipient myocardial function, recent studies suggest that skeletal muscle-derived stem cells have the ability to adopt a cardiomyocyte phenotype in vitro and in vivo. This brief review endeavors to summarize the importance of skeletal muscle stem cells and how they can play a key role to surpass current results in the future and enhance the efficacious implementation of regenerative cell therapy for heart failure. PMID:24371329

  3. Relationship between deoxyribonucleic acid content and nucleoli in human heart muscle cells and estimation of cell number during cardiac growth and hyperfunction.

    PubMed

    Adler, C P

    1975-01-01

    In the myocardium of 30 human hearts of all age groups quantitative deoxyribonucleic acid (DNA) measurements were performed and the results of the measurements were correlated with the pure myocardium weight. By means of the diphenylamine reaction the total amount of DNA (DNA concentration and DNA amount) in the myocardium was estimated. By means of Feulgen cytophotometry the DNA amount exclusively in the heart muscle cell nuclei was measured. With the use of myocardial tissue spread on slides, the nuclear areas of the heart muscle nuclei were planimetrically measured. After preparation with DNase and staining with gallocyanine chromalumn the nucleoli in heart muscle nuclei were specifically presented and their number per nucleus as well as their area values were demonstrated. From the biochemical and cytophotometric results of the myocardial DNA content it was possible to estimate the absolute cell number of the hearts, keeping the pure myocardium weight in consideration. The investigations led to the following results. In growing childrens' hearts the DNA concentration decreases to a constant level of 0.3-0.4 mg/g. The amount of DNA rises with increasing heart weight. During the growth of the heart of a child between the ages of 8 and 12 the DNA amount doubles in the heart muscle nuclei, and most of the muscle nuclei of an adult have a tetraploid DNA content. In pathological heart hypertrophy a further polyploidization of the heart muscle nuclei occurs. The areas of the nuclei increases with growing polyploidization. The nuclear areas form the same grouping as the ploidy classes. With growing nuclear areas, the total areas of the nucleoli and their number per nucleus also increase. Right after birth an increase in the number of connective tissue and heart muscle cells follows. A normal heart contains about 2 x 10(9) muscle cells. In hypertrophic hearts the number of muscle cells can double. PMID:129834

  4. Fetal heart extract facilitates the differentiation of human umbilical cord blood-derived mesenchymal stem cells into heart muscle precursor cells.

    PubMed

    Pham, Truc Le-Buu; Nguyen, Tam Thanh; Van Bui, Anh; Nguyen, My Thu; Van Pham, Phuc

    2016-08-01

    Human umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) are a promising stem cell source with the potential to modulate the immune system as well as the capacity to differentiate into osteoblasts, chondrocytes, and adipocytes. In previous publications, UCB-MSCs have been successfully differentiated into cardiomyocytes. This study aimed to improve the efficacy of differentiation of UCB-MSCs into cardiomyocytes by combining 5-azacytidine (Aza) with mouse fetal heart extract (HE) in the induction medium. UCB-MSCs were isolated from umbilical cord blood according to a published protocol. Murine fetal hearts were used to produce fetal HE using a rapid freeze-thaw procedure. MSCs at the 3rd to 5th passage were differentiated into cardiomyocytes in two kinds of induction medium: complete culture medium plus Aza (Aza group) and complete culture medium plus Aza and fetal HE (Aza + HE group). The results showed that the cells in both kinds of induction medium exhibited the phenotype of cardiomyocytes. At the transcriptional level, the cells expressed a number of cardiac muscle-specific genes such as Nkx2.5, Gata 4, Mef2c, HCN2, hBNP, α-Ca, cTnT, Desmin, and β-MHC on day 27 in the Aza group and on day 18 in the Aza + HE group. At the translational level, sarcomic α-actin was expressed on day 27 in the Aza group and day 18 in the Aza + HE group. Although they expressed specific genes and proteins of cardiac muscle cells, the induced cells in both groups did not contract and beat spontaneously. These properties are similar to properties of heart muscle precursor cells in vivo. These results demonstrated that the fetal HE facilitates the differentiation process of human UCB-MSCs into heart muscle precursor cells. PMID:25377264

  5. New muscle for old hearts: engineering tissue from pluripotent stem cells.

    PubMed

    Martin, Ulrich

    2015-05-01

    Stem cell-based therapies are considered to be promising and innovative therapeutic strategies for heart repair. Patient-derived induced pluripotent stem cells (iPSCs) are now available, which combine the advantages of autologous adult stem cells with the unlimited potential of embryonic stem cells for proliferation and differentiation. Intense research has driven dramatic progress in various areas of iPSC technology relevant for clinically applicable iPSC-based cellular therapies. At this point, it is already possible to generate transgene-free autologous iPSCs from small blood samples or hair, to scale up the expansion and differentiation of iPSCs to clinically required dimensions, and to obtain highly enriched cardiomyocyte preparations. On the other hand, critical hurdles such as the targeted specification of distinct cardiomyocyte subpopulations, survival and proper functional integration of cellular transplants after myocardial infarction, and in vitro engineering of prevascularized muscle patches have yet to be overcome. Nevertheless, concepts of cellular cardiomyoplasty seem to have come of age and the first clinical applications of iPSC-based heart repair can be expected within the coming years. PMID:25915101

  6. Isoproterenol directs hair follicle-associated pluripotent (HAP) stem cells to differentiate in vitro to cardiac muscle cells which can be induced to form beating heart-muscle tissue sheets.

    PubMed

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

    2016-03-01

    Nestin-expressing hair-follicle-associated pluripotent (HAP) stem cells are located in the bulge area of the follicle. Previous studies have shown that HAP stem cells can differentiate to neurons, glia, keratinocytes, smooth muscle cells, and melanocytes in vitro. HAP stem cells effected nerve and spinal cord regeneration in mouse models. Recently, we demonstrated that HAP stem cells differentiated to beating cardiac muscle cells. The differentiation potential to cardiac muscle cells was greatest in the upper part of the follicle. The beat rate of the cardiac muscle cells was stimulated by isoproterenol. In the present study, we observed that isoproterenol directs HAP stem cells to differentiate to cardiac muscle cells in large numbers in culture compared to HAP stem cells not supplemented with isoproterenol. The addition of activin A, bone morphogenetic protein 4, and basic fibroblast growth factor, along with isoproternal, induced the cardiac muscle cells to form tissue sheets of beating heart muscle cells. These results demonstrate that HAP stem cells have great potential to form beating cardiac muscle cells in tissue sheets. PMID:27104748

  7. 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

  8. 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.

  9. 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

  10. Comparison of two expression systems using COS7 cells and yeast cells for expression of heart/muscle-type carnitine palmitoyltransferase 1.

    PubMed

    Hada, Takuya; Kato, Yumiko; Obana, Eriko; Yamamoto, Atsushi; Yamazaki, Naoshi; Hashimoto, Mitsuru; Yamamoto, Takenori; Shinohara, Yasuo

    2012-03-01

    Carnitine palmitoyltransferase 1 (CPT1), catalyzing the transfer of the acyl group from acyl-CoA to carnitine to form acylcarnitine, is located at the outer mitochondrial membrane. Because it is easily inactivated by solubilization, expression systems using living cells are essential for its functional characterization. COS7 cells or yeast cells are often utilized for this purpose; however, the advantages/disadvantages of the use of these cells or the question as to how the CPT1 enzyme expressed by these cells differs are still uncertain. In this study, we characterized the heart/muscle-type isozyme of rat CPT1 (CPT1b) expressed by these two cellular expression systems. The mitochondrial fraction prepared from yeast cells expressing CPT1b showed 25% higher CPT1 activity than that obtained from COS7 cells. However, the expression level of CPT1b in the former was 3.8 times lower than that in the latter; and thus, under the present experimental conditions, the specific activity of CPT1b expressed in yeast cells was estimated to be approximately five times higher than that expressed in COS7 cells. Possible reasons for this difference are discussed. PMID:22266133

  11. 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

  12. Propagated repolarization in heart muscle.

    PubMed

    CRANEFIELD, P F; HOFFMAN, B F

    1958-03-20

    The effect of current flow on the transmembrane action potential of single fibers of ventricular muscle has been examined. Pulses of repolarizing current applied during the plateau of the action potential displace membrane potential much more than do pulses of depolarizing current. The application of sufficiently strong pulses of repolarizing current initiates sustained repolarization which persists after the end of the pulse. This sustained repolarization appears to propagate throughout the length of the fiber. Demonstration of propagated repolarization is made difficult by appearance of break excitation at the end of the repolarizing pulse. The thresholds for sustained repolarization and break excitation are separated by reducing the concentration of Ca(++) in the environment of the fiber. In fibers in such an environment it is easier to demonstrate apparently propagated repolarization and also, by further increase of the strength of the repolarizing current, to demonstrate graded break excitation. PMID:13514000

  13. 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...

  14. Cardiac muscle cell cytoskeletal protein 4.1: analysis of transcripts and subcellular location--relevance to membrane integrity, microstructure, and possible role in heart failure.

    PubMed

    Taylor-Harris, Pamela M; Keating, Lisa A; Maggs, Alison M; Phillips, Gareth W; Birks, Emma J; Franklin, Rodney C G; Yacoub, Magdi H; Baines, Anthony J; Pinder, Jennifer C

    2005-03-01

    The spectrin-based cytoskeleton assembly has emerged as a major player in heart functioning; however, cardiac protein 4.1, a key constituent, is uncharacterized. Protein 4.1 evolved to protect cell membranes against mechanical stresses and to organize membrane microstructure. 4.1 Proteins are multifunctional and, among other activities, link integral/signaling proteins on the plasma and internal membranes with the spectrin-based cytoskeleton. Four genes, EPB41, EPB41L1, EPB41L2, and EPB41L3 encode proteins 4.1R, 4.1N, 4.1G, and 4.1B, respectively. All are extensively spliced. Different isoforms are expressed according to tissue and developmental state, individual function being controlled through inclusion/exclusion of interactive domains. We have defined mouse and human cardiac 4.1 transcripts; other than 4. 1B in humans, all genes show activity. Cardiac transcripts constitutively include conserved FERM and C-terminal domains; both interact with membrane-bound signaling/transport/cell adhesion molecules. Variable splicing within and adjacent to the central spectrin/actin-binding domain enables regulation of cytoskeleton-binding activity. A novel heart-specific exon occurs in human 4.1G, but not in mouse. Immunofluorescence reveals 4.1 staining within mouse cardiomyocytes; thus, both at the plasma membrane and, interdigitated with sarcomeric myosin, across myofibrils in regions close to the sarcoplasmic reticulum. These are all regions to which spectrin locates. 4.1R in human heart shows similar distribution; however, there is limited plasma membrane staining. We conclude that cardiac 4.1s are highly regulated in their ability to crosslink plasma/integral cell membranes with the spectrin-actin cytoskeleton. We speculate that over the repetitive cycles of heart muscle contraction and relaxation, 4.1s are likely to locate, support, and coordinate functioning of key membrane-bound macromolecular assemblies. PMID:15834631

  15. Heart and Skeletal Muscle Are Targets of Dengue Virus Infection

    PubMed Central

    Salgado, Doris Martha; Eltit, José Miguel; Mansfield, Keith; Panqueba, César; Castro, Dolly; Vega, Martha Rocio; Xhaja, Kris; Schmidt, Diane; Martin, Katherine J.; Allen, Paul D.; Rodriguez, Jairo Antonio; Dinsmore, Jonathan H.; López, José Rafael; Bosch, Irene

    2010-01-01

    Background Dengue fever is one of the most significant re-emerging tropical diseases, despite our expanding knowledge of the disease, viral tropism is still not known to target heart tissues or muscle. Methods A prospective pediatric clinical cohort of 102 dengue hemorrhagic fever patients from Colombia, South America, was followed for 1 year. Clinical diagnosis of myocarditis was routinely performed. Electrocardiograph and echocardiograph analysis were performed to confirm those cases. Immunohistochemistry for detection of dengue virus and inflammatory markers was performed on autopsied heart tissue. In vitro studies of human striated skeletal fibers (myotubes) infected with dengue virus were used as a model for myocyte infection. Measurements of intracellular Ca2+ concentration as well as immunodetection of dengue virus and inflammation markers in infected myotubes were performed. Results Eleven children with dengue hemorrhagic fever presented with symptoms of myocarditis. Widespread viral infection of the heart, myocardial endothelium, and cardiomyocytes, accompanied by inflammation was observed in 1 fatal case. Immunofluorescence confocal microscopy showed that myotubes were infected by dengue virus and had increased expression of the inflammatory genes and protein IP-10. The infected myotubes also had increases in intracellular Ca2+ concentration. Conclusions Vigorous infection of heart tissues in vivo and striated skeletal cells in vitro are demonstrated. Derangements of Ca2+ storage in the infected cells may directly contribute to the presentation of myocarditis in pediatric patients. PMID:20032806

  16. 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

  17. 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

  18. Heart failure induces changes in acid-sensing ion channels in sensory neurons innervating skeletal muscle.

    PubMed

    Gibbons, David D; Kutschke, William J; Weiss, Robert M; Benson, Christopher J

    2015-10-15

    Heart failure is associated with diminished exercise capacity, which is driven, in part, by alterations in exercise-induced autonomic reflexes triggered by skeletal muscle sensory neurons (afferents). These overactive reflexes may also contribute to the chronic state of sympathetic excitation, which is a major contributor to the morbidity and mortality of heart failure. Acid-sensing ion channels (ASICs) are highly expressed in muscle afferents where they sense metabolic changes associated with ischaemia and exercise, and contribute to the metabolic component of these reflexes. Therefore, we tested if ASICs within muscle afferents are altered in heart failure. We used whole-cell patch clamp to study the electrophysiological properties of acid-evoked currents in isolated, labelled muscle afferent neurons from control and heart failure (induced by myocardial infarction) mice. We found that the percentage of muscle afferents that displayed ASIC-like currents, the current amplitudes, and the pH dose-response relationships were not altered in mice with heart failure. On the other hand, the biophysical properties of ASIC-like currents were significantly different in a subpopulation of cells (40%) from heart failure mice. This population displayed diminished pH sensitivity, altered desensitization kinetics, and very fast recovery from desensitization. These unique properties define these channels within this subpopulation of muscle afferents as being heteromeric channels composed of ASIC2a and -3 subunits. Heart failure induced a shift in the subunit composition of ASICs within muscle afferents, which significantly altered their pH sensing characteristics. These results might, in part, contribute to the changes in exercise-mediated reflexes that are associated with heart failure. PMID:26314284

  19. Activities of potassium and sodium ions in rabbit heart muscle.

    PubMed

    Lee, C O; Fozzard, H A

    1975-06-01

    Activities (a) of intracellular K and Na in rabbit ventricular papillary muslces were determined with cation-selectivve glass microelectrodes and concentrations (C) were estimated with flame photometry. The CK and aK of the muscles were 134.9 +/- 3.1 mM (mean value +/- SE) and 82.6 mM, respectively, at 25 degrees C. The corresponding CNa and aNa were 32.7 +/- 2.7 and 5.7, respectively. The apparent intracellular activity coefficients for K (gammaK) and Na (gammaNa) were 0.612 and 0.175, respectively. Similar results were obtained at 35 +/- 1 degree C. gammaK was substantially lower than the activity coefficient (0.745) of extracellular fluid (Tyrode's solution), which might be expected on the basis of a different intracellular ionic strength. gammaNa was much lower than that of extracellular fluid, and suggest that much of the Na was compartmentalized or sequestered. For external K concentrations greater than 5 mM, the resting membrane potentials agreed well with the potential differences calculated from the K activity gradients across the cell membrane as a potassium electrode. These results emphasize that potassium equilibrium potentials in heart muscle should be calculated by activities rather than concentrations. PMID:1194884

  20. Activities of potassium and sodium ions in rabbit heart muscle

    PubMed Central

    1975-01-01

    Activities (a) of intracellular K and Na in rabbit ventricular papillary muslces were determined with cation-selectivve glass microelectrodes and concentrations (C) were estimated with flame photometry. The CK and aK of the muscles were 134.9 +/- 3.1 mM (mean value +/- SE) and 82.6 mM, respectively, at 25 degrees C. The corresponding CNa and aNa were 32.7 +/- 2.7 and 5.7, respectively. The apparent intracellular activity coefficients for K (gammaK) and Na (gammaNa) were 0.612 and 0.175, respectively. Similar results were obtained at 35 +/- 1 degree C. gammaK was substantially lower than the activity coefficient (0.745) of extracellular fluid (Tyrode's solution), which might be expected on the basis of a different intracellular ionic strength. gammaNa was much lower than that of extracellular fluid, and suggest that much of the Na was compartmentalized or sequestered. For external K concentrations greater than 5 mM, the resting membrane potentials agreed well with the potential differences calculated from the K activity gradients across the cell membrane as a potassium electrode. These results emphasize that potassium equilibrium potentials in heart muscle should be calculated by activities rather than concentrations. PMID:1194884

  1. 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

  2. Physiological roles of taurine in heart and muscle.

    PubMed

    Schaffer, Stephen W; Jong, Chian Ju; Ramila, K C; Azuma, Junichi

    2010-01-01

    Taurine (aminoethane sulfonic acid) is an ubiquitous compound, found in very high concentrations in heart and muscle. Although taurine is classified as an amino acid, it does not participate in peptide bond formation. Nonetheless, the amino group of taurine is involved in a number of important conjugation reactions as well as in the scavenging of hypochlorous acid. Because taurine is a fairly inert compound, it is an ideal modulator of basic processes, such as osmotic pressure, cation homeostasis, enzyme activity, receptor regulation, cell development and cell signalling. The present review discusses several physiological functions of taurine. First, the observation that taurine depletion leads to the development of a cardiomyopathy indicates a role for taurine in the maintenance of normal contractile function. Evidence is provided that this function of taurine is mediated by changes in the activity of key Ca2+ transporters and the modulation Ca2+ sensitivity of the myofibrils. Second, in some species, taurine is an established osmoregulator, however, in mammalian heart the osmoregulatory function of taurine has recently been questioned. Third, taurine functions as an indirect regulator of oxidative stress. Although this action of taurine has been widely discussed, its mechanism of action is unclear. A potential mechanism for the antioxidant activity of taurine is discussed. Fourth, taurine stabilizes membranes through direct interactions with phospholipids. However, its inhibition of the enzyme, phospholipid N-methyltransferase, alters the phosphatidylcholine and phosphatidylethanolamine content of membranes, which in turn affects the function of key proteins within the membrane. Finally, taurine serves as a modulator of protein kinases and phosphatases within the cardiomyocyte. The mechanism of this action has not been studied. Taurine is a chemically simple compound, but it has profound effects on cells. This has led to the suggestion that taurine is an

  3. 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...

  4. 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

  5. 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.

  6. The use of confocal microscopy in the investigation of cell structure and function in the heart, vascular endothelium and smooth muscle cells.

    PubMed

    Bkaily, G; Pothier, P; D'Orléans-Juste, P; Simaan, M; Jacques, D; Jaalouk, D; Belzile, F; Hassan, G; Boutin, C; Haddad, G; Neugebauer, W

    1997-07-01

    In recent years, fluorescence microscopy imaging has become an important tool for studying cell structure and function. This non invasive technique permits characterization, localisation and qualitative quantification of free ions, messengers, pH, voltage and a pleiad of other molecules constituting living cells. In this paper, we present results using various commercially available fluorescent probes as well as some developed in our laboratory and discuss the advantages and limitations of these probes in confocal microscopy studies of the cardiovascular system. PMID:9278244

  7. Faster and stronger manifestation of mitochondrial diseases in skeletal muscle than in heart related to cytosolic inorganic phosphate (Pi) accumulation.

    PubMed

    Korzeniewski, Bernard

    2016-08-01

    A model of the cell bioenergetic system was used to compare the effect of oxidative phosphorylation (OXPHOS) deficiencies in a broad range of moderate ATP demand in skeletal muscle and heart. Computer simulations revealed that kinetic properties of the system are similar in both cases despite the much higher mitochondria content and "basic" OXPHOS activity in heart than in skeletal muscle, because of a much higher each-step activation (ESA) of OXPHOS in skeletal muscle than in heart. Large OXPHOS deficiencies lead in both tissues to a significant decrease in oxygen consumption (V̇o2) and phosphocreatine (PCr) and increase in cytosolic ADP, Pi, and H(+) The main difference between skeletal muscle and heart is a much higher cytosolic Pi concentration in healthy tissue and much higher cytosolic Pi accumulation (level) at low OXPHOS activities in the former, caused by a higher PCr level in healthy tissue (and higher total phosphate pool) and smaller Pi redistribution between cytosol and mitochondria at OXPHOS deficiency. This difference does not depend on ATP demand in a broad range. A much greater Pi increase and PCr decrease during rest-to-moderate work transition in skeletal muscle at OXPHOS deficiencies than at normal OXPHOS activity significantly slows down the V̇o2 on-kinetics. Because high cytosolic Pi concentrations cause fatigue in skeletal muscle and can compromise force generation in skeletal muscle and heart, this system property can contribute to the faster and stronger manifestation of mitochondrial diseases in skeletal muscle than in heart. Shortly, skeletal muscle with large OXPHOS deficiencies becomes fatigued already during low/moderate exercise. PMID:27283913

  8. Muscle stem cells at a glance.

    PubMed

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

    2014-11-01

    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

  9. Organophosphate inhibition of human heart muscle cholinesterase isoenzymes.

    PubMed

    Chemnitius, J M; Sadowski, R; Winkel, H; Zech, R

    1999-05-14

    The rate of acetylcholine hydrolysis of mammalian heart muscle influences cardiac responses to vagal innervation. We characterized cholinesterases of human left ventricular heart muscle with respect to both substrate specificity and irreversible inhibition kinetics with the organophosphorus inhibitor N,N'-di-isopropylphosphorodiamidic fluoride (mipafox). Specimens were obtained postmortem from three men and four women (61 +/- 5 years) with no history of cardiovascular disease. Myocardial choline ester hydrolyzing activity was determined with acetylthiocholine (ASCh; 1.25 mM), acetyl-beta-methylthiocholine (AbetaMSCh; 2.0 mM), and butyrylthiocholine (BSCh; 30 mM). After irreversible and covalent inhibition (60 min; 25 degrees C) with a wide range of mipafox concentrations (50 nM-5 mM), residual choline ester hydrolyzing activities were fitted to a sum of up to five exponentials using weighted least-squares non-linear curve fitting. In each ease, quality of curve fitting reached its optimum on the basis of a four component model. Final classification of heart muscle cholinesterases was achieved according to substrate hydrolysis patterns (nmol/min per g wet weight) and to second-order organophosphate inhibition rate constants k2 (1/mol per min); one choline ester hydrolyzing enzyme was identified as acetylcholinesterase (AChE; k2/mipafox = 6.1 (+/- 0.8) x 10(2)), and one as butyrylcholinesterase (BChE; k2/mipafox = 5.3 (+/- 1.1) x 10(3)). An enzyme exhibiting both ChE-like substrate specificity and relative resistance to mipafox inhibition (k2/mipafox = 5.2 (+/- 1.0) x 10(-1)) was classified as atypical cholinesterase. PMID:10421452

  10. 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

  11. 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

  12. 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.

  13. Adult stem cells: the therapeutic potential of skeletal muscle.

    PubMed

    Saini, Amarjit; Stewart, Claire E H

    2006-05-01

    Embryonic stem cells have revolutionised our understanding of normal and deregulated growth and development. The potential to produce cells and tissues as needed offers enormous therapeutic potential. The use of these cells, however, is accompanied by ongoing ethical, religious and biomedical issues. The expansion potential and plasticity of adult stem cells have therefore received much interest. Adult skeletal muscle is highly adaptable, responding to both the hypertrophic and degenerative stresses placed upon it. This extreme plasticity is in part regulated by resident stem cells. In addition to regenerating muscle, if exposed to osteogenic or adipogenic inducers, these cells spontaneously form osteoblasts or adipocytes. The potential for and heterogeneity of muscle stem cells is underscored by the observation that CD45+ muscle side population cells are capable of reconstituting bone marrow in lethally irradiated mice and of contributing to neo-vascularisation of regenerating muscle. Finally, first attempts to replace infarcted myocardium relied on injection of skeletal myoblasts into the heart. Cells successfully engrafted and cardiac function was improved. Harnessing their differentiation/trans-differentiation capacity provides enormous potential for adult stem cells. In this review, current understanding of the different stem cells within muscle will be discussed as will their potential utility for regenerative medicine. PMID:18220864

  14. 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

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

    PubMed

    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

  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. 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

  18. Self-oscillating gels beating like a heart muscle

    PubMed Central

    Yoshida, Ryo

    2012-01-01

    So far stimuli-responsive polymer gels and their application to smart materials have been widely studied. On the other hand, as a novel biomimetic gel, we developed gels with an autonomous self-oscillating function like a heart muscle, which was firstly reported in 1996. We designed the self-oscillating polymers and gels by utilizing the oscillating reaction, called the Belousov-Zhabotinsky (BZ) reaction. The self-oscillating polymer is composed of a poly(N-isopropylacrylamide) network in which the catalyst for the BZ reaction is covalently immobilized. In the presence of the reactants, the polymer gel undergoes spontaneous cyclic swelling–deswelling changes without any on–off switching of external stimuli. Potential applications of the self-oscillating polymers and gels include several kinds of functional material systems, such as bio-mimetic actuators and mass transport surface. In this review, recent progress on the polymer gels is introduced.

  19. 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

  20. 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

  1. Coaxing stem cells for skeletal muscle repair

    PubMed Central

    McCullagh, Karl J.A.; Perlingeiro, Rita C. R.

    2014-01-01

    Skeletal muscle has a tremendous ability to regenerate, attributed to a well-defined population of muscle stem cells called satellite cells. However, this ability to regenerate diminishes with age and can also be dramatically affected by multiple types of muscle diseases, or injury. Extrinsic and/or intrinsic defects in the regulation of satellite cells are considered to be major determinants for the diminished regenerative capacity. Maintenance and replenishment of the satellite cell pool is one focus for muscle regenerative medicine, which will be discussed. There are other sources of progenitor cells with myogenic capacity, which may also support skeletal muscle repair. However, all of these myogenic cell populations have inherent difficulties and challenges in maintaining or coaxing their derivation for therapeutic purpose. This review will highlight recent reported attributes of these cells and new bioengineering approaches to creating a supply of myogenic stem cells or implants applicable for acute and/or chronic muscle disorders. PMID:25049085

  2. Variable optimization for the formation of three-dimensional self-organized heart muscle.

    PubMed

    Khait, Luda; Hodonsky, Chani J; Birla, Ravi K

    2009-12-01

    Cardiac tissue-engineering research is focused on the development of functional three-dimensional (3D) heart muscle in vitro. These models allow the detailed study of critical events in organogenesis, such as the establishment of cell-cell communication and construction and modification of the extracellular matrix. We have previously described a model for 3D heart muscle, termed cardioids, formed by the spontaneous delamination of a cohesive monolayer of primary cells in the absence of any synthetic scaffolding material. In an earlier publication, we have shown that, upon electrical stimulation, cardioids generate a twitch force in the range of 200-300 microN, generate a specific force (twitch force normalized to total cross-sectional area) of 2-4 kN/m(2), and can be electrically paced at frequencies of up to 10 Hz without any notable fatigue. We have two objectives for the current study: model development and model optimization. Our model development efforts are focused on providing additional characterization of the cardioid model. In this study, we show for the first time that cardioids show a pattern of gene expression comparable to that of cells cultured in two dimensions on tissue culture plastic and normal mammalian heart muscle. Compared with primary cardiac cells cultured on tissue culture plastic, the expression of alpha-myosin heavy chain (MHC), beta-MHC, SERCA2, and phospholamban was significantly higher in cardioids. Our second objective, model optimization, is focused on evaluating the effect of several cell culture variables on cardioid formation and function. Specifically, we looked at the effect of plating density (1.0-4.0 x 10(6) cells per cardioid), concentration of two adhesion proteins (laminin at 0.2-2.0 microg/cm(2) and fibronectin at 1-10 microg/cm(2)), myocyte purity (using preplating times of 15 and 60 min), and ascorbic acid stimulation (1-100 microl/ml). For our optimization studies, we utilized twitch force in response to electrical

  3. Epigenetic regulation of smooth muscle cell plasticity.

    PubMed

    Liu, Renjing; Leslie, Kristen L; Martin, Kathleen A

    2015-04-01

    Smooth muscle cells (SMC) are the major cell type in blood vessels. Their principal function in the body is to regulate blood flow and pressure through vessel wall contraction and relaxation. Unlike many other mature cell types in the adult body, SMC do not terminally differentiate but retain a remarkable plasticity. They have the unique ability to toggle between a differentiated and quiescent "contractile" state and a highly proliferative and migratory "synthetic" phenotype in response to environmental stresses. While there have been major advances in our understanding of SMC plasticity through the identification of growth factors and signals that can influence the SMC phenotype, how these regulate SMC plasticity remains unknown. To date, several key transcription factors and regulatory cis elements have been identified that play a role in modulating SMC state. The frontier in understanding the molecular mechanisms underlying SMC plasticity has now advanced to the level of epigenetics. This review will summarize the epigenetic regulation of SMC, highlighting the role of histone modification, DNA methylation, and our most recent identification of a DNA demethylation pathway in SMC that is pivotal in the regulation of the SMC phenotypic state. Many disorders are associated with smooth muscle dysfunction, including atherosclerosis, the major underlying cause of stroke and coronary heart disease, as well as transplant vasculopathy, aneurysm, asthma, hypertension, and cancer. An increased understanding of the major regulators of SMC plasticity will lead to the identification of novel target molecules that may, in turn, lead to novel drug discoveries for the treatment of these diseases. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity. PMID:24937434

  4. Skeletal muscle beta-receptors and isoproterenol-stimulated vasodilation in canine heart failure

    SciTech Connect

    Frey, M.J.; Lanoce, V.; Molinoff, P.B.; Wilson, J.R. )

    1989-11-01

    To investigate whether heart failure alters beta-adrenergic receptors on skeletal muscle and its associated vasculature, the density of beta-adrenergic receptors, isoproterenol-stimulated adenylate cyclase activity, and coupling of the guanine nucleotide-binding regulatory protein were compared in 18 control dogs and 16 dogs with heart failure induced by 5-8 wk of ventricular pacing at 260 beats/min. Hindlimb vascular responses to isoproterenol were compared in eight controls and eight of the dogs with heart failure. In dogs with heart failure, the density of beta-receptors on skeletal muscle was reduced in both gastrocnemius (control: 50 +/- 5; heart failure: 33 +/- 8 fmol/mg of protein) and semitendinosus muscle (control: 43 +/- 9; heart failure: 27 +/- 9 fmol/mg of protein, both P less than 0.05). Receptor coupling to the ternary complex, as determined by isoproterenol competition curves with and without guanosine 5'-triphosphate (GTP), was unchanged. Isoproterenol-stimulated adenylate cyclase activity was significantly decreased in semitendinosus muscle (control: 52.4 +/- 4.6; heart failure: 36.5 +/- 9.5 pmol.mg-1.min-1; P less than 0.05) and tended to be decreased in gastrocnemius muscle (control: 40.1 +/- 8.5; heart failure: 33.5 +/- 4.5 pmol.mg-1.min-1; P = NS). Isoproterenol-induced hindlimb vasodilation was not significantly different in controls and in dogs with heart failure. These findings suggest that heart failure causes downregulation of skeletal muscle beta-adrenergic receptors, probably due to receptor exposure to elevated catecholamine levels, but does not reduce beta-receptor-mediated vasodilation in muscle.

  5. Syndecan-4-expressing muscle progenitor cells in the SP engraft as satellite cells during muscle regeneration.

    PubMed

    Tanaka, Kathleen Kelly; Hall, John K; Troy, Andrew A; Cornelison, D D W; Majka, Susan M; Olwin, Bradley B

    2009-03-01

    Skeletal muscle satellite cells, located between the basal lamina and plasma membrane of myofibers, are required for skeletal muscle regeneration. The capacity of satellite cells as well as other cell lineages including mesoangioblasts, mesenchymal stem cells, and side population (SP) cells to contribute to muscle regeneration has complicated the identification of a satellite stem cell. We have characterized a rare subset of the muscle SP that efficiently engrafts into the host satellite cell niche when transplanted into regenerating muscle, providing 75% of the satellite cell population and 30% of the myonuclear population, respectively. These cells are found in the satellite cell position, adhere to isolated myofibers, and spontaneously undergo myogenesis in culture. We propose that this subset of SP cells (satellite-SP cells), characterized by ABCG2, Syndecan-4, and Pax7 expression, constitutes a self-renewing muscle stem cell capable of generating both satellite cells and their myonuclear progeny in vivo. PMID:19265661

  6. 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

  7. 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

  8. Cell death regulates muscle fiber number.

    PubMed

    Sarkissian, Tatevik; Arya, Richa; Gyonjyan, Seda; Taylor, Barbara; White, Kristin

    2016-07-01

    Cell death can have both cell autonomous and non-autonomous roles in normal development. Previous studies have shown that the central cell death regulators grim and reaper are required for the developmentally important elimination of stem cells and neurons in the developing central nervous system (CNS). Here we show that cell death in the nervous system is also required for normal muscle development. In the absence of grim and reaper, there is an increase in the number of fibers in the ventral abdominal muscles in the Drosophila adult. This phenotype can be partially recapitulated by inhibition of cell death specifically in the CNS, indicating a non-autonomous role for neuronal death in limiting muscle fiber number. We also show that FGFs produced in the cell death defective nervous system are required for the increase in muscle fiber number. Cell death in the muscle lineage during pupal stages also plays a role in specifying fiber number. Our work suggests that FGFs from the CNS act as a survival signal for muscle founder cells. Thus, proper muscle fiber specification requires cell death in both the nervous system and in the developing muscle itself. PMID:27131625

  9. 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

  10. Epigenetic regulation of smooth muscle cell plasticity

    PubMed Central

    Liu, Renjing; Leslie, Kristen L.; Martin, Kathleen A.

    2014-01-01

    Smooth muscle cells (SMC) are the major cell type in blood vessels. Their principle function in the body is to regulate blood flow and pressure through vessel wall contraction and relaxation. Unlike many other mature cell types in the adult body, SMC do not terminally differentiate but retain a remarkable plasticity. They have the unique ability to toggle between a differentiated and quiescent “contractile” state and a highly proliferative and migratory “synthetic” phenotype in response to environmental stresses. While there have been major advances in our understanding of SMC plasticity through the identification of growth factors and signals that can influence the SMC phenotype, how these regulate SMC plasticity remains unknown. To date, several key transcription factors and regulatory cis elements have been identified that play a role in modulating SMC state. The frontier in understanding the molecular mechanisms underlying SMC plasticity has now advanced to the level of epigenetics. This review will summarize the epigenetic regulation of SMC, highlighting the role of histone modification, DNA methylation, and our most recent identification of a DNA demethylation pathway in SMC that is pivotal in the regulation of the SMC phenotypic state. Many disorders are associated with smooth muscle dysfunction, including atherosclerosis, the major underlying cause of stroke and coronary heart disease, as well as transplant vasculopathy, aneurysm, asthma, hypertension, and cancer. An increased understanding of the major regulators of SMC plasticity will lead to the identification of novel target molecules that may, in turn, lead to novel drug discoveries for the treatment of these diseases. PMID:24937434

  11. 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

  12. Stem cells for heart valve regeneration.

    PubMed

    Weber, Benedikt; Emmert, Maximilian Y; Hoerstrup, Simon P

    2012-01-01

    Heart valve tissue engineering holds the potential to overcome limitations of currently used heart valve prostheses. It involves the isolation and expansion of autologous patient cells, the subsequent seeding of these cells onto an appropriate scaffold material, the in vitro incubation and the in vivo implantation of the derived tissue-engineered construct into the patient from whom the cells were taken. While vascular-derived cells require harvest of intact donor tissue and show limited expansion capacities, the use of stem or progenitor cells may overcome these limitations and expand the versatility of the concept of heart valve tissue engineering. Possible sources include cells isolated from blood, bone marrow, adipose tissue, amniotic fluid, chorionic villi, umbilical cord and induced pluripotent stem cells. Here we review different stem cell sources with particular regard to cellular phenotypes and their suitability for application in heart valve tissue engineering. PMID:22802212

  13. Glycogen metabolism in rat heart muscle cultures after hypoxia.

    PubMed

    Vigoda, Ayelet; Mamedova, Liaman K; Shneyvays, Vladimir; Katz, Abram; Shainberg, Asher

    2003-12-01

    Elevated glycogen levels in heart have been shown to have cardioprotective effects against ischemic injury. We have therefore established a model for elevating glycogen content in primary rat cardiac cells grown in culture and examined potential mechanisms for the elevation (glycogen supercompensation). Glycogen was depleted by exposing the cells to hypoxia for 2 h in the absence of glucose in the medium. This was followed by incubating the cells with 28 mM glucose in normoxia for up to 120 h. Hypoxia decreased glycogen content to about 15% of control, oxygenated cells. This was followed by a continuous increase in glycogen in the hypoxia treated cells during the 120 h recovery period in normoxia. By 48 h after termination of hypoxia, the glycogen content had returned to baseline levels and by 120 h glycogen was about 150% of control. The increase in glycogen at 120 h was associated with comparable relative increases in glucose uptake (approximately 180% of control) and the protein level of the glut-1 transporter (approximately 170% of control), whereas the protein level of the glut-4 transporter was decreased to < 10% of control. By 120 h, the hypoxia-treated cells also exhibited marked increases in the total (approximately 170% of control) and fractional activity of glycogen synthase (control, approximately 15%; hypoxia-treated, approximately 30%). Concomitantly, the hypoxia-treated cells also exhibited marked decreases in the total (approximately 50% of control) and fractional activity of glycogen phosphorylase (control, approximately 50%; hypoxia-treated, approximately 25%). Thus, we have established a model of glycogen supercompensation in cultures of cardiac cells that is explained by concerted increases in glucose uptake and glycogen synthase activity and decreases in phosphorylase activity. This model should prove useful in studying the cardioprotective effects of glycogen. PMID:14674711

  14. Stem cell niches in the adult mouse heart

    PubMed Central

    Urbanek, Konrad; Cesselli, Daniela; Rota, Marcello; Nascimbene, Angelo; De Angelis, Antonella; Hosoda, Toru; Bearzi, Claudia; Boni, Alessandro; Bolli, Roberto; Kajstura, Jan; Anversa, Piero; Leri, Annarosa

    2006-01-01

    Cardiac stem cells (CSCs) have been identified in the adult heart, but the microenvironment that protects the slow-cycling, undifferentiated, and self-renewing CSCs remains to be determined. We report that the myocardium possesses interstitial structures with the architectural organization of stem cell niches that harbor long-term BrdU-retaining cells. The recognition of long-term label-retaining cells provides functional evidence of resident CSCs in the myocardium, indicating that the heart is an organ regulated by a stem cell compartment. Cardiac niches contain CSCs and lineage-committed cells, which are connected to supporting cells represented by myocytes and fibroblasts. Connexins and cadherins form gap and adherens junctions at the interface of CSCs–lineage-committed cells and supporting cells. The undifferentiated state of CSCs is coupled with the expression of α4-integrin, which colocalizes with the α2-chain of laminin and fibronectin. CSCs divide symmetrically and asymmetrically, but asymmetric division predominates, and the replicating CSC gives rise to one daughter CSC and one daughter committed cell. By this mechanism of growth kinetics, the pool of primitive CSCs is preserved, and a myocyte progeny is generated together with endothelial and smooth muscle cells. Thus, CSCs regulate myocyte turnover that is heterogeneous across the heart, faster at the apex and atria, and slower at the base–midregion of the ventricle. PMID:16754876

  15. Types of muscle tissue (image)

    MedlinePlus

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

  16. Cardiac Cell Lineages that Form the Heart

    PubMed Central

    Meilhac, Sigolène M.; Lescroart, Fabienne; Blanpain, Cédric; Buckingham, Margaret E.

    2014-01-01

    Myocardial cells ensure the contractility of the heart, which also depends on other mesodermal cell types for its function. Embryological experiments had identified the sources of cardiac precursor cells. With the advent of genetic engineering, novel tools have been used to reconstruct the lineage tree of cardiac cells that contribute to different parts of the heart, map the development of cardiac regions, and characterize their genetic signature. Such knowledge is of fundamental importance for our understanding of cardiogenesis and also for the diagnosis and treatment of heart malformations. PMID:25183852

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

    PubMed

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

    2016-04-01

    Conclusion Induced pluripotent stem (iPS) cells may be a new potential cell source for laryngeal muscle regeneration in the treatment of vocal fold atrophy after recurrent laryngeal nerve paralysis. Objectives Unilateral vocal fold paralysis can lead to degeneration, atrophy, and loss of force of the thyroarytenoid muscle. At present, there are some treatments such as thyroplasty, arytenoid adduction, and vocal fold injection. However, such treatments cannot restore reduced mass of the thyroarytenoid muscle. iPS cells have been recognized as supplying a potential resource for cell transplantation. The aim of this study was to assess the effectiveness of the use of iPS cells for the regeneration of laryngeal muscle through the evaluation of both in vitro and in vivo experiments. Methods Skeletal muscle cells were generated from tdTomato-labeled iPS cells using embryoid body formation. Differentiation into skeletal muscle cells was analyzed by gene expression and immunocytochemistry. The tdTomato-labeled iPS cell-derived skeletal muscle cells were transplanted into the left atrophied thyroarytenoid muscle. To evaluate the engraftment of these cells after transplantation, immunohistochemistry was performed. Results The tdTomato-labeled iPS cells were successfully differentiated into skeletal muscle cells through an in vitro experiment. These cells survived in the atrophied thyroarytenoid muscle after transplantation. PMID:26824385

  18. 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

  19. 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

  20. 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. PMID:25572546

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

    PubMed Central

    Vermillion, Katie L.; Anderson, Kyle J.; Hampton, Marshall

    2015-01-01

    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. PMID:25572546

  2. Heart Health

    MedlinePlus

    ... Connected Home » Heart Health Heath and Aging Heart Health Your Heart Changes to Your Heart With ... are both taking steps toward heart health. Your Heart Your heart is a strong muscle about the ...

  3. Combination stem cell therapy for heart failure

    PubMed Central

    2010-01-01

    Patients with congestive heart failure (CHF) that are not eligible for transplantation have limited therapeutic options. Stem cell therapy such as autologous bone marrow, mobilized peripheral blood, or purified cells thereof has been used clinically since 2001. To date over 1000 patients have received cellular therapy as part of randomized trials, with the general consensus being that a moderate but statistically significant benefit occurs. Therefore, one of the important next steps in the field is optimization. In this paper we discuss three ways to approach this issue: a) increasing stem cell migration to the heart; b) augmenting stem cell activity; and c) combining existing stem cell therapies to recapitulate a "therapeutic niche". We conclude by describing a case report of a heart failure patient treated with a combination stem cell protocol in an attempt to augment beneficial aspects of cord blood CD34 cells and mesenchymal-like stem cells. PMID:20398245

  4. Cardiac progenitor cells for heart repair

    PubMed Central

    Le, TYL; Chong, JJH

    2016-01-01

    Stem cell therapy is being investigated as an innovative and promising strategy to restore cardiac function in patients with heart failure. Several stem cell populations, including adult (multipotent) stem cells from developed organs and tissues, have been tested for cardiac repair with encouraging clinical and pre-clinical results. The heart has been traditionally considered a post-mitotic organ, however, this view has recently changed with the identification of stem/progenitor cells residing within the adult heart. Given their cardiac developmental origins, these endogenous cardiac progenitor cells (CPCs) may represent better candidates for cardiac cell therapy compared with stem cells from other organs such as the bone marrow and adipose tissue. This brief review will outline current research into CPC populations and their cardiac repair/regenerative potential. PMID:27551540

  5. Heterogeneity in the muscle satellite cell population

    PubMed Central

    Biressi, Stefano; Rando, Thomas A.

    2010-01-01

    Satellite cells, the adult stem cells responsible for skeletal muscle regeneration, are defined by their location between the basal lamina and the fiber sarcolemma. Increasing evidence suggests that satellite cells represent a heterogeneous population of cells with distinct embryological origin and multiple levels of biochemical and functional diversity. This review focuses on the rich diversity of the satellite cell population based on studies across species. Ultimately, a more complete characterization of the heterogeneity of satellite cells will be essential to understand the functional significance in terms of muscle growth, homeostasis, tissue repair, and aging. PMID:20849971

  6. Bioenergetics of the aging heart and skeletal muscles: Modern concepts and controversies.

    PubMed

    Tepp, Kersti; Timohhina, Natalja; Puurand, Marju; Klepinin, Aleksandr; Chekulayev, Vladimir; Shevchuk, Igor; Kaambre, Tuuli

    2016-07-01

    Age-related alterations in the bioenergetics of the heart and oxidative skeletal muscle tissues are of crucial influence on their performance. Until now the prevailing concept of aging was the mitochondrial theory, the increased production of reactive oxygen species, mediated by deficiency in the activity of respiratory chain complexes. However, studies with mitochondria in situ have presented results which, to some extent, disagree with previous ones, indicating that the mitochondrial theory of aging may be overestimated. The studies reporting age-related decline in mitochondrial function were performed using mainly isolated mitochondria. Measurements on this level are not able to take into account the system level properties. The relevant information can be obtained only from appropriate studies using cells or tissue fibers. The functional interactions between the components of Intracellular Energetic Unit (ICEU) regulate the energy production and consumption in oxidative muscle cells. The alterations of these interactions in ICEU should be studied in order to find a more effective protocol to decelerate the age-related changes taking place in the energy metabolism. In this article, an overview is given of the present theories and controversies of causes of age-related alterations in bioenergetics. Also, branches of study, which need more emphasis, are indicated. PMID:27063513

  7. Forever young: rejuvenating muscle satellite cells

    PubMed Central

    Madaro, Luca; Latella, Lucia

    2015-01-01

    A hallmark of aging is alteration of organismal homeostasis and progressive decline of tissue functions. Alterations of both cell intrinsic functions and regenerative environmental cues contribute to the compromised stem cell activity and reduced regenerative capability occurring in aged muscles. In this perspective, we discuss the new evidence supporting the hypothesis that skeletal muscle stem cells (MuSCs) are intrinsically defective in elderly muscles. In particular, we review three recent papers leading to identify fibroblast growth factor receptor-1, p38 mitogen-activated protein kinase, and p16INK4a as altered signaling in satellite cells from aged mice. These pathways contribute to age-related loss of MuSCs asymmetric polarization, compromised self-renewal capacity, and acquisition of pre-senescent state. The pharmacological manipulation of those networks can open novel strategies to rejuvenate MuSCs and counteract the functional decline of skeletal muscle during aging. PMID:25954192

  8. 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

  9. Immunohistochemical detection of piscine reovirus (PRV) in hearts of Atlantic salmon coincide with the course of heart and skeletal muscle inflammation (HSMI)

    PubMed Central

    2012-01-01

    Aquaculture is the fastest growing food production sector in the world. However, the increased production has been accompanied by the emergence of infectious diseases. Heart and skeletal muscle inflammation (HSMI) is one example of an emerging disease in farmed Atlantic salmon (Salmo salar L). Since the first recognition as a disease entity in 1999 it has become a widespread and economically important disease in Norway. The disease was recently found to be associated with infection with a novel reovirus, piscine reovirus (PRV). The load of PRV, examined by RT-qPCR, correlated with severity of HSMI in naturally and experimentally infected salmon. The disease is characterized by epi-, endo- and myocarditis, myocardial necrosis, myositis and necrosis of the red skeletal muscle. The aim of this study was to investigate the presence of PRV antigens in heart tissue of Atlantic salmon and monitor the virus distribution in the heart during the disease development. This included target cell specificity, viral load and tissue location during an HSMI outbreak. Rabbit polyclonal antisera were raised against putative PRV capsid proteins μ1C and σ1 and used in immunohistochemical analysis of archived salmon heart tissue from an experimental infection. The results are consistent with the histopathological changes of HSMI and showed a sequential staining pattern with PRV antigens initially present in leukocyte-like cells and subsequently in cardiomyocytes in the heart ventricle. Our results confirm the association between PRV and HSMI, and strengthen the hypothesis of PRV being the causative agent of HSMI. Immunohistochemical detection of PRV antigens will be beneficial for the understanding of the pathogenesis of HSMI as well as for diagnostic purposes. PMID:22486941

  10. Stem Cell Treatment of the Heart

    PubMed Central

    Angelini, Paolo; Markwald, Roger R.

    2005-01-01

    Stem cells are multipotent, undifferentiated cells capable of multiplication and differentiation. Preliminary experimental evidence suggests that stem cells derived from embryonic or adult tissues (especially bone marrow) may develop into myocardial cells. Some experts believe that this phenomenon occurs naturally in human beings, specifically during recovery from a myocardial infarction. Recently, stem cells have been used with the therapeutic intention of regenerating damaged tissues. Cardiac experiments, mainly with adult homologous stem cells, have proved that this therapy is safe and may improve myocardial vascularization and pump function. We review current fundamental concepts regarding the normal development of embryonic stem cells into myocardial tissue and the heart as a whole. We describe the multiple conditions that naturally enable a stem cell to become a myocardial cell and a group of stem cells to become a heart. We also discuss the challenge of translating basic cellular and molecular mechanisms into effective, clinically relevant treatment options. PMID:16429891

  11. Detyrosinated microtubules modulate mechanotransduction in heart and skeletal muscle

    PubMed Central

    Kerr, Jaclyn P.; Robison, Patrick; Shi, Guoli; Bogush, Alexey I.; Kempema, Aaron M.; Hexum, Joseph K.; Becerra, Natalia; Harki, Daniel A.; Martin, Stuart S.; Raiteri, Roberto; Prosser, Benjamin L.; Ward, Christopher W.

    2015-01-01

    In striated muscle, X-ROS is the mechanotransduction pathway by which mechanical stress transduced by the microtubule network elicits reactive oxygen species. X-ROS tunes Ca2+ signalling in healthy muscle, but in diseases such as Duchenne muscular dystrophy (DMD), microtubule alterations drive elevated X-ROS, disrupting Ca2+ homeostasis and impairing function. Here we show that detyrosination, a post-translational modification of α-tubulin, influences X-ROS signalling, contraction speed and cytoskeletal mechanics. In the mdx mouse model of DMD, the pharmacological reduction of detyrosination in vitro ablates aberrant X-ROS and Ca2+ signalling, and in vivo it protects against hallmarks of DMD, including workload-induced arrhythmias and contraction-induced injury in skeletal muscle. We conclude that detyrosinated microtubules increase cytoskeletal stiffness and mechanotransduction in striated muscle and that targeting this post-translational modification may have broad therapeutic potential in muscular dystrophies. PMID:26446751

  12. Detection of skeletal muscle fatigue in patients with heart failure using electromyography.

    PubMed

    Wilson, J R; Mancini, D M; Simson, M

    1992-08-15

    Patients with heart failure frequently report that leg fatigue limits maximal exercise capacity. However, objective documentation of muscle fatigue has not been obtained in such patients. In normal subjects, muscle fatigue during constant work load exercise is associated with an increase in electrical activity generated per contraction due to use of additional muscle fibers to compensate for fiber fatigue. The present study was performed to determine if this approach can be used to document muscle fatigue in patients with heart failure. Vastus lateralis surface electromyograms were monitored in 8 ambulatory patients with nonedematous heart failure and 6 normal subjects during maximal bicycle exercise (20 W increments every 2 minutes). The electromyogram was stored on tape and subsequently analyzed for integrated root-mean-square voltage/contraction (iRMSV). At each work load, the iRMSV of the first and last 30 seconds of the work load were compared. The maximal work load achieved by patients with heart failure was significantly lower (73 +/- 22 W) than that by normal subjects (150 +/- 15 W; p less than 0.01). Both groups had no significant difference between the initial and final iRMSV at submaximal work loads. However, during the 2 highest work loads, both groups reported leg fatigue and had significant increases in iRMSV, consistent with muscle fiber fatigue (maximal work load: 259 +/- 59 to 279 +/- 58 mv.ms [normals] vs 258 +/- 94 to 283 +/- 93 mv.ms [heart failure]; p less than 0.03). The data indicate that the surface electromyogram can be used to detect skeletal muscle fatigue in patients with heart failure.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1642187

  13. Control of cell volume in skeletal muscle.

    PubMed

    Usher-Smith, Juliet A; Huang, Christopher L-H; Fraser, James A

    2009-02-01

    Regulation of cell volume is a fundamental property of all animal cells and is of particular importance in skeletal muscle where exercise is associated with a wide range of cellular changes that would be expected to influence cell volume. These complex electrical, metabolic and osmotic changes, however, make rigorous study of the consequences of individual factors on muscle volume difficult despite their likely importance during exercise. Recent charge-difference modelling of cell volume distinguishes three major aspects to processes underlying cell volume control: (i) determination by intracellular impermeant solute; (ii) maintenance by metabolically dependent processes directly balancing passive solute and water fluxes that would otherwise cause cell swelling under the influence of intracellular membrane-impermeant solutes; and (iii) volume regulation often involving reversible short-term transmembrane solute transport processes correcting cell volumes towards their normal baselines in response to imposed discrete perturbations. This review covers, in turn, the main predictions from such quantitative analysis and the experimental consequences of comparable alterations in extracellular pH, lactate concentration, membrane potential and extracellular tonicity. The effects of such alterations in the extracellular environment in resting amphibian muscles are then used to reproduce the intracellular changes that occur in each case in exercising muscle. The relative contributions of these various factors to the control of cell volume in resting and exercising skeletal muscle are thus described. PMID:19133959

  14. Replication of Muscle Cell Using Bioimprint

    NASA Astrophysics Data System (ADS)

    Samsuri, Fahmi; Mitchell, John S.; Alkaisi, Maan M.; Evans, John J.

    2009-07-01

    In our earlier study a heat-curable PDMS or a UV curable elastomer, was used as the replicating material to introduce Bioimprint methodology to facilitate cell imaging [1-2] But, replicating conditions for thermal polymerization is known to cause cell dehydration during curing. In this study, a new type of polymer was developed for use in living cell replica formation, and it was tested on human muscle cells. The cells were incubated and cultured according to standard biological culturing procedures, and they were grown for about 10 days. The replicas were then separated from the muscle cells and taken for analysis under an Atomic Force Microscope (AFM). The new polymer was designed to be biocompatible with higher resolution and fast curing process compared to other types of silicon-based organic polymers such as polydimethylsiloxane (PDMS). Muscle cell imprints were achieved and higher resolution images were able to show the micro structures of the muscle cells, including the cellular fibers and cell membranes. The AFM is able to image features at nanoscale resolution. This capacity enables a number of characteristics of biological cells to be visualized in a unique manner. Polymer and muscle cells preparations were developed at Hamilton, in collaboration between Plant and Food Research and the Department of Electrical and Computer Engineering, University of Canterbury. Tapping mode was used for the AFM image analysis as it has low tip-sample forces and non-destructive imaging capability. We will be presenting the bioimprinting processes of muscle cells, their AFM imaging and characterization of the newly developed polymer.

  15. Isolated muscle cells as a physiological model.

    PubMed

    Lieberman, M; Hauschka, S D; Hall, Z W; Eisenberg, B R; Horn, R; Walsh, J V; Tsien, R W; Jones, A W; Walker, J L; Poenie, M

    1987-09-01

    Summary of a symposium presented by the American Physiological Society (Cell and General Physiology Section and Muscle Group) at the 70th Annual Meeting of the Federation of American Societies for Experimental Biology, St. Louis, Missouri, April 15, 1986, chaired by M. Lieberman and F. Fay. This symposium reflects a growing interest in seeking new technologies to study the basic physiological and biophysical properties of cardiac, smooth, and skeletal muscle cells. Recognizing that technical and analytical problems associated with multicellular preparations limit the physiological significance of many experiments, investigators have increasingly focused on efforts to isolate single, functional embryonic, and adult muscle cells. Progress in obtaining physiologically relevant preparations has been both rapid and significant even though problems regarding cell purification and viability are not fully resolved. The symposium draws attention to a broad, though incomplete, range of studies using isolated or cultured muscle cells. Based on the following reports, investigators should be convinced that a variety of experiments can be designed with preparations of isolated cells and those in tissue culture to resolve questions about fundamental physiological properties of muscle cells. PMID:2443014

  16. 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

  17. 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. PMID:27521089

  18. Three-dimensional segmentation of the heart muscle using image statistics

    NASA Astrophysics Data System (ADS)

    Nillesen, Maartje M.; Lopata, Richard G. P.; Gerrits, Inge H.; Kapusta, Livia; Huisman, Henkjan H.; Thijssen, Johan M.; de Korte, Chris L.

    2006-03-01

    Segmentation of the heart muscle in 3D echocardiographic images provides a tool for visualization of cardiac anatomy and assessment of heart function, and serves as an important pre-processing step for cardiac strain imaging. By incorporating spatial and temporal information of 3D ultrasound image sequences (4D), a fully automated method using image statistics was developed to perform 3D segmentation of the heart muscle. 3D rf-data were acquired with a Philips SONOS 7500 live 3D ultrasound system, and an X4 matrix array transducer (2-4 MHz). Left ventricular images of five healthy children were taken in transthoracial short/long axis view. As a first step, image statistics of blood and heart muscle were investigated. Next, based on these statistics, an adaptive mean squares filter was selected and applied to the images. Window size was related to speckle size (5x2 speckles). The degree of adaptive filtering was automatically steered by the local homogeneity of tissue. As a result, discrimination of heart muscle and blood was optimized, while sharpness of edges was preserved. After this pre-processing stage, homomorphic filtering and automatic thresholding were performed to obtain the inner borders of the heart muscle. Finally, a deformable contour algorithm was used to yield a closed contour of the left ventricular cavity in each elevational plane. Each contour was optimized using contours of the surrounding planes (spatial and temporal) as limiting condition to ensure spatial and temporal continuity. Better segmentation of the ventricle was obtained using 4D information than using information of each plane separately.

  19. Skeletal muscle metabolism during exercise in patients with chronic heart failure.

    PubMed Central

    Schaufelberger, M.; Eriksson, B. O.; Held, P.; Swedberg, K.

    1996-01-01

    OBJECTIVE: To investigate the metabolic response of skeletal muscle to exercise in patients with chronic heart failure and determine its relation to central haemodynamic variables. SETTING: University hospital in Sweden. PARTICIPANTS: 16 patients in New York Heart Association class II-III and 10 healthy controls. MAIN OUTCOME MEASURES: Skeletal muscle biopsies were obtained from the quadriceps muscle at rest and at submaximal and maximal exercise. Right sided heart catheterisation was performed in eight patients. RESULTS: The patients had lower maximal oxygen consumption than the control group (13.2 (2.9) v 26.8 (4.4) ml/kg/min, P < 0.001). They had reduced activities of citrate synthetase (P < 0.05) and 3-hydroxyacyl-CoA dehydrogenase (P < 0.05) compared with the controls. At maximal exercise adenosine triphosphate (P < 0.05), creatine phosphate (P < 0.01), and glycogen (P < 0.01) were higher whereas glucose (P < 0.001) and lactate (P < 0.06) were lower in the patients than in the controls. Citrate synthetase correlated inversely with skeletal muscle lactate at submaximal exercise (r = -0.90, P < 0.003). No correlations between haemodynamic variables and skeletal muscle glycogen, glycolytic intermediates, and adenosine nucleotides during exercise were found. CONCLUSION: Neither skeletal muscle energy compounds nor lactate accumulation were limiting factors for exercise capacity in patients with chronic heart failure. The decreased activity of oxidative enzymes may have contributed to the earlier onset of anaerobic metabolism, but haemodynamic variables seemed to be of lesser importance for skeletal muscle metabolism during exercise. PMID:8774324

  20. Hypertrophy and hyperplasia of smooth muscle cells of small intramyocardial arteries in spontaneously hypertensive rats.

    PubMed

    Amann, K; Gharehbaghi, H; Stephen, S; Mall, G

    1995-01-01

    Hearts of stroke-prone spontaneously hypertensive rats (SHR) were investigated by means of stereology and were compared with those of normotensive. Wistar-Kyoto controls. At the age of 9 months, hypertensive rats showed cardiac hypertrophy, marked myocardial fibrosis, activation of nonvascular interstitium, focal myocytial degeneration, reduction of capillarization, and microarteriopathy of small intramyocardial arteries. Stereologically, a significant increase in the total left ventricular arterial wall volume (+180% versus controls) was found in SHR hearts. By using new stereological techniques, the orientator and the nucleator, we investigated whether this significant increase in total left ventricular arterial wall volume was due to hyperplasia of smooth muscle cells in addition to the process of vascular smooth muscle cell hypertrophy that is common in SHR. Additionally, the nuclear size and ratio of cell volume to nuclear volume were determined using another new stereological technique, the selector. The stereological data indicate a significant increase in mean cell and nuclear volumes as well as in the total number of left ventricular arterial smooth muscle cells of SHR. Additionally, the total length of intramyocardial arteries was also significantly increased in hypertensive rats. The volume and number of arterial smooth muscle cells per arterial length were significantly (P < .001 and P < .05, respectively) higher in SHR than in normotensive controls. Thus, we conclude that hypertrophy and hyperplasia of smooth muscle cells are involved in intramyocardial arterial growth processes in hypertensive heart remodeling.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7843743

  1. Stimulating Cardiac Muscle by Light: Cardiac Optogenetics by Cell Delivery

    PubMed Central

    Jia, Zhiheng; Valiunas, Virginijus; Lu, Zongju; Bien, Harold; Liu, Huilin; Wang, Hong-Zhang; Rosati, Barbara; Brink, Peter R.; Cohen, Ira S.; Entcheva, Emilia

    2011-01-01

    Background After the recent cloning of light-sensitive ion channels and their expression in mammalian cells, a new field, optogenetics, emerged in neuroscience, allowing for precise perturbations of neural circuits by light. However, functionality of optogenetic tools has not been fully explored outside neuroscience; and a non-viral, non-embryogenesis based strategy for optogenetics has not been shown before. Methods and Results We demonstrate the utility of optogenetics to cardiac muscle by a tandem cell unit (TCU) strategy, where non-excitable cells carry exogenous light-sensitive ion channels, and when electrically coupled to cardiomyocytes, produce optically-excitable heart tissue. A stable channelrhodopsin2 (ChR2) expressing cell line was developed, characterized and used as a cell delivery system. The TCU strategy was validated in vitro in cell pairs with adult canine myocytes (for a wide range of coupling strengths) and in cardiac syncytium with neonatal rat cardiomyocytes. For the first time, we combined optical excitation and optical imaging to capture light-triggered muscle contractions and high-resolution propagation maps of light-triggered electrical waves, found to be quantitatively indistinguishable from electrically-triggered waves. Conclusions Our results demonstrate feasibility to control excitation and contraction in cardiac muscle by light using the TCU approach. Optical pacing in this case uses less energy, offers superior spatiotemporal control, remote access and can serve not only as an elegant tool in arrhythmia research, but may form the basis for a new generation of light-driven cardiac pacemakers and muscle actuators. The TCU strategy is extendable to (non-viral) stem cell therapy and is directly relevant to in vivo applications. PMID:21828312

  2. Muscle oxygen transport and utilization in heart failure: implications for exercise (in)tolerance

    PubMed Central

    Hirai, Daniel M.; Copp, Steven W.; Musch, Timothy I.

    2012-01-01

    The defining characteristic of chronic heart failure (CHF) is an exercise intolerance that is inextricably linked to structural and functional aberrations in the O2 transport pathway. CHF reduces muscle O2 supply while simultaneously increasing O2 demands. CHF severity varies from moderate to severe and is assessed commonly in terms of the maximum O2 uptake, which relates closely to patient morbidity and mortality in CHF and forms the basis for Weber and colleagues' (167) classifications of heart failure, speed of the O2 uptake kinetics following exercise onset and during recovery, and the capacity to perform submaximal exercise. As the heart fails, cardiovascular regulation shifts from controlling cardiac output as a means for supplying the oxidative energetic needs of exercising skeletal muscle and other organs to preventing catastrophic swings in blood pressure. This shift is mediated by a complex array of events that include altered reflex and humoral control of the circulation, required to prevent the skeletal muscle “sleeping giant” from outstripping the pathologically limited cardiac output and secondarily impacts lung (and respiratory muscle), vascular, and locomotory muscle function. Recently, interest has also focused on the dysregulation of inflammatory mediators including tumor necrosis factor-α and interleukin-1β as well as reactive oxygen species as mediators of systemic and muscle dysfunction. This brief review focuses on skeletal muscle to address the mechanistic bases for the reduced maximum O2 uptake, slowed O2 uptake kinetics, and exercise intolerance in CHF. Experimental evidence in humans and animal models of CHF unveils the microvascular cause(s) and consequences of the O2 supply (decreased)/O2 demand (increased) imbalance emblematic of CHF. Therapeutic strategies to improve muscle microvascular and oxidative function (e.g., exercise training and anti-inflammatory, antioxidant strategies, in particular) and hence patient exercise

  3. 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

  4. 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

  5. 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

  6. 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.

  7. TRPC channels in smooth muscle cells.

    PubMed

    Gonzalez-Cobos, Jose C; Trebak, Mohamed

    2010-01-01

    Transient receptor potential canonical (TRPC) proteins constitute a family of seven (TRPC1-7) nonselective cation channels within the wider TRP superfamily. TRPC1, TRPC3, TRPC4, TRPC5 and TRPC6 channels are expressed in vascular smooth muscle cells from human vessels of all calibers and in smooth muscle from organs such as the uterus and the gastrointestinal tract. TRPC channels have recently emerged as important players in the control of smooth muscle function. This review will focus on the retrospective analysis of studies proposing contributions of TRPC channels to native calcium entry pathways in smooth muscle and to physiological and pathophysiological responses with emphasis on the vascular system. PMID:20515740

  8. Penetration of teicoplanin into heart valves and subcutaneous and muscle tissues of patients undergoing open-heart surgery.

    PubMed

    Frank, U K; Schmidt-Eisenlohr, E; Mlangeni, D; Schindler, M; Hoh, A; Beyersdorf, F; Daschner, F D

    1997-11-01

    Penetration of teicoplanin into serum, heart valves, and subcutaneous and muscle tissues was determined in 22 patients undergoing open-heart surgery. Each patient received 12 mg of teicoplanin per kg of body weight as a 30-min intravenous infusion preoperatively. Within 10 h, serum concentrations of teicoplanin declined from 43.1 to 2.8 microg/ml. Teicoplanin concentrations in subcutaneous tissues reached their peak of 9.2 microg/g after 2 to 3 h and decreased slowly to 2.3 microg/g after 9 to 10 h. Concentrations in muscle decreased from 8.7 microg/g to nondetectable levels. Teicoplanin concentrations in cardiac valvular tissue reached their peak of 6.1 microg/g and decreased thereafter to 1.7 microg/g. Teicoplanin concentrations in heart valves were high enough to inhibit methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci, which are known to cause postoperative wound infections and infective endocarditis. PMID:9371368

  9. Penetration of teicoplanin into heart valves and subcutaneous and muscle tissues of patients undergoing open-heart surgery.

    PubMed Central

    Frank, U K; Schmidt-Eisenlohr, E; Mlangeni, D; Schindler, M; Hoh, A; Beyersdorf, F; Daschner, F D

    1997-01-01

    Penetration of teicoplanin into serum, heart valves, and subcutaneous and muscle tissues was determined in 22 patients undergoing open-heart surgery. Each patient received 12 mg of teicoplanin per kg of body weight as a 30-min intravenous infusion preoperatively. Within 10 h, serum concentrations of teicoplanin declined from 43.1 to 2.8 microg/ml. Teicoplanin concentrations in subcutaneous tissues reached their peak of 9.2 microg/g after 2 to 3 h and decreased slowly to 2.3 microg/g after 9 to 10 h. Concentrations in muscle decreased from 8.7 microg/g to nondetectable levels. Teicoplanin concentrations in cardiac valvular tissue reached their peak of 6.1 microg/g and decreased thereafter to 1.7 microg/g. Teicoplanin concentrations in heart valves were high enough to inhibit methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci, which are known to cause postoperative wound infections and infective endocarditis. PMID:9371368

  10. Trichloroethylene interactions with muscle cells.

    PubMed

    Kössler, F

    1991-06-01

    The toxic effect of trichlorethylene (TCE) was investigated on isolated muscles prepared from frog and rats. Twitch and tetanic contractions as well as caffeine-induced contractures, were recorded. Trichloroethylene at a concentration of 0.25-4.0 mM depressed the force development of both twitch and tetanic tension in a dose-dependent manner. This effect was not influenced by the type of muscle. As TCE shortened the time to peak of twitch contractions, it may alter the Ca2+ binding kinetics. Subthreshold caffeine concentrations applied after pre-exposure to TCE (1 or 2mM) induced contractures. The same TCE exposure enhanced regular caffeine contractures through increasing the speed of tension development and the absolute force. Exposure to 5 or 10 mM TCE did not affect the first caffeine-induced contracture but enhanced the potency of the second caffeine dose given 15 min after the first. The results suggest that the interaction of TCE with membrane sites is responsible for Ca2+ release for contractile processes. PMID:1918792

  11. 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

  12. 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...

  13. Skeletal muscle myofibrillar protein oxidation in heart failure and the protective effect of Carvedilol.

    PubMed

    Dalla Libera, Luciano; Ravara, Barbara; Gobbo, Valerio; Danieli Betto, Daniela; Germinario, Elena; Angelini, Annalisa; Vescovo, Giorgio

    2005-05-01

    Heart failure is characterized by limited exercise tolerance and by a skeletal muscle myopathy with atrophy and shift toward fast fibres. An inflammatory status with elevated pro-inflammatory cytokines and exaggerated free radicals production, can worsen muscle damage. In a well established model of heart failure, the monocrotaline treated rat, we show that CHF is accompanied by oxidation of the skeletal muscle actin, tropomyosin and myosin, which further depresses muscle function and exercise capacity. We have also tested the efficacy of Carvedilol, a non-selective beta(1)-beta(2)-blocker, which has been widely used in clinical trials to improve exercise tolerance and reduce mortality in moderate and severe CHF, in preventing contractile protein oxidation in CHF rats. As comparison we used Bisoprolol a beta(1) selective agent, without known anti-oxidative properties. Carvedilol at the dose of 2 mg/kg per day was able to prevent the myofibrillar protein oxidation, while Bisoprolol (0.1 mg/kg) did it only partially, as demonstrated by the oxyblot analysis. While Carvedilol improved force production on isolated muscles, Bisoprolol did not. After the COMET trial, the anti-oxidative capacity of Carvedilol has been invoked as one of the mechanism that makes this drug superior to other selective beta-blockers in the treatment of CHF. One of the reason of Carvedilol superiority could be the effect on skeletal muscle with reduction of contractile protein peroxidation, amelioration of muscle function and improvement of exercise tolerance. Inhibition of reactive oxygen species (ROS) production, and of pro-inflammatory cytokines may also lead to a decreased muscle wastage, another factor contributing to worsening of exercise tolerance. PMID:15850574

  14. Stem Cell Therapy Shows Promise Against Heart Failure

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_158122.html Stem Cell Therapy Shows Promise Against Heart Failure A second ... 4, 2016 MONDAY, April 4, 2016 (HealthDay News) -- Stem cell therapy shows promise for people battling heart failure, ...

  15. Cardiac regenerative potential of cardiosphere-derived cells from adult dog hearts

    PubMed Central

    Hensley, Michael Taylor; de Andrade, James; Keene, Bruce; Meurs, Kathryn; Tang, Junnan; Wang, Zegen; Caranasos, Thomas G; Piedrahita, Jorge; Li, Tao-Sheng; Cheng, Ke

    2015-01-01

    The regenerative potential of cardiosphere-derived cells (CDCs) for ischaemic heart disease has been demonstrated in mice, rats, pigs and a recently completed clinical trial. The regenerative potential of CDCs from dog hearts has yet to be tested. Here, we show that canine CDCs can be produced from adult dog hearts. These cells display similar phenotypes in comparison to previously studied CDCs derived from rodents and human beings. Canine CDCs can differentiate into cardiomyocytes, smooth muscle cells and endothelial cells in vitro. In addition, conditioned media from canine CDCs promote angiogenesis but inhibit cardiomyocyte death. In a doxorubicin-induced mouse model of dilated cardiomyopathy (DCM), intravenous infusion of canine CDCs improves cardiac function and decreases cardiac fibrosis. Histology revealed that injected canine CDCs engraft in the mouse heart and increase capillary density. Out study demonstrates the regenerative potential of canine CDCs in a mouse model of DCM. PMID:25854418

  16. The control of calcium release in heart muscle.

    PubMed

    Cannell, M B; Cheng, H; Lederer, W J

    1995-05-19

    The control of calcium release from intracellular stores (the sarcoplasmic reticulum) in cardiac muscle was examined with the use of a confocal microscope and voltage clamp techniques. Depolarization evoked graded calcium release by altering the extent of spatial and temporal summation of elementary calcium release events called "calcium sparks." These evoked sparks were triggered by local L-type calcium channel currents in a stochastic manner, were similar at different potentials, and resembled spontaneous calcium sparks. Once triggered, the calcium release from the sarcoplasmic reticulum during a calcium spark was independent of the duration of the triggering calcium influx. These results were used to develop a unifying model for cardiac excitation-contraction coupling that explains the large (but paradoxically stable) amplification of the trigger calcium influx by a combination of digital and analog behavior. PMID:7754384

  17. 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

  18. 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.

  19. Inspiratory Muscle Training in Patients with Heart Failure: A Systematic Review

    PubMed Central

    Lin, Suh-Jen; McElfresh, Jessica; Hall, Benjamin; Bloom, Rachel; Farrell, Kellie

    2012-01-01

    Purpose The purpose of this review was to assess the quality of evidence on inspiratory muscle training (IMT) in patients with heart failure and to provide an overview on subject selection, training protocols, and outcome achieved with IMT. Methods Literature search was first performed via the PubMed database, and additional references were identified from the Scopus citation index. Articles of the review type and of clinical trials published in English were included. Quality of the articles was assessed using Sackett's levels of evidence and rigor of methodology was assessed using PEDro (Physiotherapy Evidence Database) criteria for randomized controlled trials and the Downs & Black tool for cohort studies. Results Twelve articles of clinical trials were included. Typical training protocols involved daily training with intensity greater than 30% of maximal inspiratory pressure (PImax), duration of 20 to 30 minutes (continuous or incremental) and using a pressure threshold muscle trainer. The effect sizes of PImax, walk test distance, and dyspnea were moderate to large across these studies. Effects on quality of life scores were inconsistent. Conclusion Inspiratory muscle training is beneficial for improving respiratory muscle strength, functional capacity, and dyspnea in patients with stable heart failure and respiratory muscle weakness. PMID:22993500

  20. 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.

  1. 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

  2. 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. PMID:26948993

  3. 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

  4. The influence of "hylase" on the ultrastructure of ischaemic heart muscle changes.

    PubMed

    David, H; Lindenau, K F; Behrisch, D

    1980-01-01

    A two-hour acute ischaemia of the myocardium was induced in dogs by ligature of the coronary arteries and the effect produced on the qualitative and quantitative ultrastructure of heart muscle cells by infusing "hylase", a hyaluronidase preparation, was examined. The changes in both the central and peripheral ischaemic zones following hylase infusion are more severe than after ischaemia alone. Particularly the mitochondria showed an increased dissolution of the outer membrane. In the case of ischaemia the percentage of mitochondria in the peripheral zone is 29.6%, in the central zone 27.6%; after hylase infusion it is 25.9% in the peripheral zone and 32.3% in the central zone. After hylase infusion, the percentage of sarcoplasm in the central zone rises to 120.7% and to 186.8% in the peripheral zone. In view of the fact that macroscopic, histological and histochemical findings also show negative effects, the infusion of hyaluronidase is not recommended. PMID:7398839

  5. Resident c-kit(+) cells in the heart are not cardiac stem cells.

    PubMed

    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

  6. 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

  7. Muscle satellite cell heterogeneity and self-renewal

    PubMed Central

    Motohashi, Norio; Asakura, Atsushi

    2014-01-01

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

  8. 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

  9. A sauvagine/corticotropin-releasing factor receptor expressed in heart and skeletal muscle.

    PubMed Central

    Kishimoto, T; Pearse, R V; Lin, C R; Rosenfeld, M G

    1995-01-01

    Corticotropin-releasing factor (CRF) mediates many critical aspects of the physiological response to stress. These effects are elicited by binding to specific high-affinity receptors, which are coupled to guanine nucleotide stimulatory factor (Gs)-response pathways. Recently, a gene encoding a receptor for CRF, expressed in pituitary and the central nervous system (PC-CRF receptor), was isolated and characterized. Here we report the identification and characterization of a second, distinct CRF receptor that is expressed primarily in heart and skeletal muscle and exhibits a specific ligand preference and antagonist sensitivity compared with the PC-CRF receptor. We refer to this second receptor as the heart/muscle (HM)-CRF receptor. Images Fig. 1 Fig. 4 PMID:7755719

  10. 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.

  11. 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. PMID:26013034

  12. 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.

  13. The Popeye domain containing 2 (popdc2) gene in zebrafish is required for heart and skeletal muscle development

    PubMed Central

    Kirchmaier, Bettina C.; Poon, Kar Lai; Schwerte, Thorsten; Huisken, Jan; Winkler, Christoph; Jungblut, Benno; Stainier, Didier Y.; Brand, Thomas

    2013-01-01

    The Popeye domain containing (Popdc) genes encode a family of transmembrane proteins with an evolutionary conserved Popeye domain. These genes are abundantly expressed in striated muscle tissue, however their function is not well understood. In this study we have investigated the role of the popdc2 gene in zebrafish. Popdc2 transcripts were detected in the embryonic myocardium and transiently in the craniofacial and tail musculature. Morpholino oligonucleotide-mediated knockdown of popdc2 resulted in aberrant development of skeletal muscle and heart. Muscle segments in the trunk were irregularly shaped and craniofacial muscles were severely reduced or even missing. In the heart, pericardial edema was prevalent in the morphants and heart chambers were elongated and looping was abnormal. These pathologies in muscle and heart were alleviated after reducing the morpholino concentration. However the heart still was abnormal displaying cardiac arrhythmia at later stages of development. Optical recordings of cardiac contractility revealed irregular ventricular contractions with a 2:1, or 3:1 atrial/ventricular conduction ratio, which caused a significant reduction in heart frequency. Recordings of calcium transients with high spatiotemporal resolution using a transgenic calcium indicator line (Tg(cmlc2:gCaMP)s878) and SPIM microscopy confirmed the presence of a severe arrhythmia phenotype. Our results identify popdc2 as a gene important for striated muscle differentiation and cardiac morphogenesis. In addition it is required for the development of the cardiac conduction system. PMID:22290329

  14. [Changes of heart function after different cell type stem cell transplantation in chronic heart failure].

    PubMed

    Fan, Zhongcai; Chen, Mao; Deng, Juelin; Liu, Xiaojing; Zhang, Li; Rao, Li; Yang, Qing; Huang, Dejia

    2006-12-01

    To investigate the feasibility of introcoronary cell infusion into nonischemic heart failure (HF) heart and whether different types of stem cell transplantation would affect heart function to a similar degree. Japanese white ears rabbits were used as HF models by intravenous injection adriamycin. Autologous bone marrow mononuclear cells(BMCs), bone marrow stromal cells (MSCs), skeletal myoblasts (SMs) or culture medium were infused into coronary arteries respectively by occluding the root of ascending aorta. The mortality during and 4 weeks after the procedure the mortality was 7.1% and 16.7% respectively. After 4 weeks, the ejection fraction (EF) in BMCs group had significant improvement (P < 0.05, n=8). No significant difference was seen in MSCs (n =8), SMs (n=6) and sham groups (n=8) compared with pretransplantation (P > 0.05). In sham group,the left ventricular endostolic diameter (LVED) had significant enlargement (P < 0.05), No significant difference was seen in MBCs, MSCs and SMs groups compared with pretransplantation (P > 0.05). Immunofluorescence revealed de novo expression of cardiac troponin I in BMCs and MSCs groups, cardiac troponin I was not detected in SMs group. In conclusions, intracoronary cell transplantation could provide effective cell delivery into dilated cardiomyopathy hearts and could be a useful strategy for treating CHF, BMCs cell transplantation may be the first choice in all the above cell types. PMID:17228727

  15. On endocytosis of foreign ferritin and occurrence of phagolysosomes in fish heart endothelial cells.

    PubMed

    Leknes, Ingvar Leiv

    2016-04-01

    In the present study the ultrastructure and function of the endothelial cells enveloping the muscle trabeculae in heart in two teleosts, platyfish and firemouth cichlid, are described and discussed. These cells displayed a structure making them able to take up large amounts of foreign ferritin particles from the blood stream. The ferritin particles were assembled into huge phagolysosomes. Large amounts of Prussian blue were precipitated throughout these lysosomes when treated with acid ferrohexacyanide solution. The occurrence of Prussian blue precipitations in the control heart endothelial cells after Schmorl's solution, suggests that these cells normally contain undigestible material, a finding which strengthens the view that this tissue is involved in blood clearance in the present species. In conclusion, these heart endothelial cells seem able to perform a very efficient blood clearance of scavenger and foreign macromolecules and particles in the present species. PMID:26852295

  16. 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. PMID:27055812

  17. Regulation of insulin-like growth factor-I in skeletal muscle and muscle cells.

    PubMed

    Frost, R A; Lang, C H

    2003-03-01

    Growth hormone (GH) and insulin-like growth factor-I (IGF-I) are potent regulators of muscle mass. Transgenic mice that over-express these proteins exhibit dramatically enlarged skeletal muscles. In contrast, malnutrition, critical illness, sepsis, and aging are all associated with a dramatic reduction in muscle mass and function. The circulating concentration of IGF-I and the expression of IGF-I in skeletal muscle are also reduced during catabolic states. Consequently, GH has been used clinically to increase lean body mass in patients with muscle wasting. Likewise, delivery of IGF-I specifically into muscle has been proposed as a genetic therapy for muscle disorders. A better understanding of the regulation of IGF-I expression in skeletal muscle and muscle cells is therefore of importance. Yet, our knowledge in this area has been limited by a lack of GH responsive muscle cells. In addition the IGF-I gene spans over 90 kb of genomic DNA and it exhibits a very complex regulatory pattern. This review will summarize our knowledge of the control of muscle mass by GH, IGF-I, anabolic steroids, exercise and other growth enhancing hormones. We will also highlight recent advances in the regulation of IGF-I and signal transducers and activators of transcription (Stats) by GH. A special emphasis will be placed on the interaction of IGF-I and proinflammatory cytokines in skeletal muscle and muscle cells. PMID:12621363

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

    PubMed Central

    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

    2015-01-01

    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. PMID:26104526

  19. Isoforms of protein 4.1 are differentially distributed in heart muscle cells: relation of 4.1R and 4.1G to components of the Ca2+ homeostasis system.

    PubMed

    Pinder, Jennifer C; Taylor-Harris, Pamela M; Bennett, Pauline M; Carter, Edward; Hayes, Nandini V L; King, Mikayala D A; Holt, Mark R; Maggs, Alison M; Gascard, Philippe; Baines, Anthony J

    2012-08-01

    The 4.1 proteins are cytoskeletal adaptor proteins that are linked to the control of mechanical stability of certain membranes and to the cellular accumulation and cell surface display of diverse transmembrane proteins. One of the four mammalian 4.1 proteins, 4.1R (80 kDa/120 kDa isoforms), has recently been shown to be required for the normal operation of several ion transporters in the heart (Stagg MA et al. Circ Res, 2008; 103: 855-863). The other three (4.1G, 4.1N and 4.1B) are largely uncharacterised in the heart. Here, we use specific antibodies to characterise their expression, distribution and novel activities in the left ventricle. We detected 4.1R, 4.1G and 4.1N by immunofluorescence and immunoblotting, but not 4.1B. Only one splice variant of 4.1N and 4.1G was seen whereas there are several forms of 4.1R. 4.1N, like 4.1R, was present in intercalated discs, but unlike 4.1R, it was not localised at the lateral plasma membrane. Both 4.1R and 4.1N were in internal structures that, at the level of resolution of the light microscope, were close to the Z-disc (possibly T-tubules). 4.1G was also in intracellular structures, some of which were coincident with sarcoplasmic reticulum. 4.1G existed in an immunoprecipitable complex with spectrin and SERCA2. 80 kDa 4.1R was present in subcellular fractions enriched in intercalated discs, in a complex resistant to solubilization under non-denaturing conditions. At the intercalated disc 4.1R does not colocalise with the adherens junction protein, β-catenin, but does overlap with the other plasma membrane signalling proteins, the Na/K-ATPase and the Na/Ca exchanger NCX1. We conclude that isoforms of 4.1 proteins are differentially compartmentalised in the heart, and that they form specific complexes with proteins central to cardiomyocyte Ca(2+) metabolism. PMID:22429617

  20. Osteogenic potential of alpha smooth muscle actin expressing muscle resident progenitor cells.

    PubMed

    Matthews, Brya G; Torreggiani, Elena; Roeder, Emilie; Matic, Igor; Grcevic, Danka; Kalajzic, Ivo

    2016-03-01

    Heterotopic ossification (HO) is a pathological process where bone forms in connective tissues such as skeletal muscle. Previous studies have suggested that muscle-resident non-myogenic mesenchymal progenitors are the likely source of osteoblasts and chondrocytes in HO. However, the previously identified markers of muscle-resident osteoprogenitors label up to half the osteoblasts within heterotopic lesions, suggesting other cell populations are involved. We have identified alpha smooth muscle actin (αSMA) as a marker of osteoprogenitor cells in bone and periodontium, and of osteo-chondro progenitors in the periosteum during fracture healing. We therefore utilized a lineage tracing approach to evaluate whether αSMACreERT2 identifies osteoprogenitors in the muscle. We show that in the muscle, αSMACreERT2 labels both perivascular cells, and satellite cells. αSMACre-labeled cells undergo osteogenic differentiation in vitro and form osteoblasts and chondrocytes in BMP2-induced HO in vivo. In contrast, Pax7CreERT2-labeled muscle satellite cells were restricted to myogenic differentiation in vitro, and rarely contributed to HO in vivo. Our data indicate that αSMACreERT2 labels a large proportion of osteoprogenitors in skeletal muscle, and therefore represents another marker of muscle-resident cells with osteogenic potential under HO-inducing stimulus. In contrast, muscle satellite cells make minimal contribution to bone formation in vivo. PMID:26721734

  1. The Potential of Stem Cells in the Treatment of Skeletal Muscle Injury and Disease

    PubMed Central

    MacLean, S.; Khan, W. S.; Malik, A. A.; Anand, S.; Snow, M.

    2012-01-01

    Tissue engineering is a pioneering field with huge advances in recent times. These advances are not only in the understanding of how cells can be manipulated but also in potential clinical applications. Thus, tissue engineering, when applied to skeletal muscle cells, is an area of huge prospective benefit to patients with muscle disease/damage. This could include damage to muscle from trauma and include genetic abnormalities, for example, muscular dystrophies. Much of this research thus far has been focused on satellite cells, however, mesenchymal stem cells have more recently come to the fore. In particular, results of trials and further research into their use in heart failure, stress incontinence, and muscular dystrophies are eagerly awaited. Although no doubt, stem cells will have much to offer in the future, the results of further research still limit their use. PMID:22220178

  2. Collagen formation by transformed smooth muscle cells after arterial injury.

    PubMed

    Chidi, C C; DePalma, R G

    1981-01-01

    Twenty-five normocholesterolemic rabbits were sacrificed at intervals up to 60 days after the thoracic aortas were de-endothelialized. Ultrastructural studies of both the re-endothelialized and nonendothelialized intima were done. The smooth muscle cells in the re-endothelialized intima showed segmental structural changes typically associated with transformation to a secretory cell type; abundant accumulations of collagen were in juxtaposition with these cells. The nonendothelialized intima did not demonstrate similar smooth muscle cell changes and collagen accumulation. These observations suggest that regenerating endothelial cells and intimal smooth muscle cells interact to cause smooth muscle cell transformation and collagen accumulation during arterial repair. PMID:7455897

  3. 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.

  4. Fat cell invasion in long-term denervated skeletal muscle.

    PubMed

    de Castro Rodrigues, Antonio; Andreo, Jesus Carlos; Rosa, Geraldo Marco; dos Santos, Nícolas Bertolaccini; Moraes, Luis Henrique Rapucci; Lauris, José Roberto P

    2007-01-01

    There are several differences between red and white muscles submitted to different experimental conditions, especially following denervation: a) denervation atrophy is more pronounced in red than white muscles; b) the size of the fibers in the red muscles does not vary between different parts of the muscle before and after denervation, when compared to white muscles; c) the regional difference in the white muscles initially more pronounced after denervation than red muscle; d) red muscle fibers and fibers of the deep white muscle present degenerative changes such as disordered myofibrils and sarcolemmal folds after long-term denervation; e) myotube-like fibers with central nuclei occur in the red muscle more rapidly than white after denervation. Denervation of skeletal muscles causes, in addition to fibers atrophy, loss of fibers with subsequent regeneration, but the extent of fat cell percentage invasion is currently unknown. The present article describes a quantitative study on fat cell invasion percentage in red m. soleus and white m. extensor digitorum longus (EDL) rat muscles at 7 weeks for up to 32 weeks postdenervation. The results indicate that the percentage of fat cells increase after denervation and it is steeper than the age-related fat invasion in normal muscles. The fat percentage invasion is more pronounced in red compared with white muscle. All experimental groups present a statistically significant difference as regard fat cell percentage invasion. PMID:17941108

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

    PubMed

    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. PMID:11744638

  6. 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.

  7. Analysis of Skeletal Muscle Torque Capacity and Circulating Ceramides in Patients with Advanced Heart Failure

    PubMed Central

    Brunjes, Danielle L.; Dunlop, Mark; Wu, Christina; Jones, Meaghan; Kato, Tomoko S.; Kennel, Peter J.; Armstrong, Hilary F.; Choo, Tse-Hwei; Bartels, Matthew N.; Forman, Daniel E.; Mancini, Donna M.; Schulze, P. Christian

    2016-01-01

    Background Heart failure (HF)-related exercise intolerance is thought to be perpetuated by peripheral skeletal muscle functional, structural, and metabolic abnormalities. We analyzed specific dynamics of muscle contraction in patients with HF compared with healthy, sedentary controls. Methods Isometric and isokinetic muscle parameters were measured in the dominant upper and lower limbs of 45 HF patients and 15 healthy age-matched controls. Measurements included peak torque normalized to body weight, work normalized to body weight, power, time to peak torque, and acceleration and deceleration to maximum strength times. Body morphometry (dual energy X-ray absorptiometry scan) and circulating fatty acids and ceramides (lipodomics) were analyzed in a subset of subjects (18 HF and 9 controls). Results Extension and flexion time-to-peak torque was longer in the lower limbs of HF patients. Furthermore, acceleration and deceleration times in the lower limbs were also prolonged in HF subjects. HF subjects had increased adiposity and decreased lean muscle mass compared with controls. Decreased circulating unsaturated fatty acids and increased ceramides were found in subjects with HF. Conclusions Delayed torque development suggests skeletal muscle impairments that may reflect abnormal neuromuscular functional coupling. These impairments may be further compounded by increased adiposity and inflammation associated with increased ceramides. PMID:26879888

  8. Reaction of human smooth muscle antibody with thyroid cells

    PubMed Central

    Biberfeld, Gunnel; Fagraeus, Astrid; Lenkei, Rodica

    1974-01-01

    Sera from cases of active chronic hepatitis or acute hepatitis containing smooth muscle antibodies reacted by immunofluorescence with the membrane region of sectioned thyroid cells from thyrotoxic glands. With non-toxic glands the reaction was negative or weak. The prerequisite for a positive reaction was that the complement of the sera had been heat-inactivated. Absorption with smooth muscle antigen abolished the reaction of smooth muscle antibody positive sera with thyroid cells. Some smooth muscle antibody negative sera from cases with disorders other than liver disease were found to give a similar immunofluorescence staining of the membrane region of sectioned thyroid cells, but these antibodies were not absorbed with smooth muscle antigen. Culture of thyroid cells was found to increase the number of cells reacting with smooth muscle antibody. In contrast, the thyroid cell antigen reacting with smooth muscle antibody negative sera was lost during culture. PMID:4619977

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

    PubMed Central

    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

  10. 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

  11. Stem Cell Therapy for Ischemic Heart Disease

    PubMed Central

    Jameel, Mohammad Nurulqadr

    2010-01-01

    Abstract Stem cell transplantation has emerged as a novel treatment option for ischemic heart disease. Different cell types have been utilized and the recent development of induced pluripotent stem cells has generated tremendous excitement in the regenerative field. Bone marrow-derived multipotent progenitor cell transplantation in preclinical large animal models of postinfarction left ventricular remodeling has demonstrated long-term functional and bioenergetic improvement. These beneficial effects are observed despite no significant engraftment of bone marrow cells in the myocardium and even lower differentiation of these cells into cardiomyocytes. It is thought to be related to the paracrine effect of these stem cells, which secrete factors that lead to long-term gene expression changes in the host myocardium, thereby promoting neovascularization, inhibiting apoptosis, and stimulating resident cardiac progenitor cells. Future studies are warranted to examine the changes in the recipient myocardium after stem cell transplantation and to investigate the signaling pathways involved in these effects. Antioxid. Redox Signal. 13, 1879–1897. PMID:20687781

  12. 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. PMID:26597703

  13. Human ES-cell-derived cardiomyocytes electrically couple and suppress arrhythmias in injured hearts.

    PubMed

    Shiba, Yuji; Fernandes, Sarah; Zhu, Wei-Zhong; Filice, Dominic; Muskheli, Veronica; Kim, Jonathan; Palpant, Nathan J; Gantz, Jay; Moyes, Kara White; Reinecke, Hans; Van Biber, Benjamin; Dardas, Todd; Mignone, John L; Izawa, Atsushi; Hanna, Ramy; Viswanathan, Mohan; Gold, Joseph D; Kotlikoff, Michael I; Sarvazyan, Narine; Kay, Matthew W; Murry, Charles E; Laflamme, Michael A

    2012-09-13

    Transplantation studies in mice and rats have shown that human embryonic-stem-cell-derived cardiomyocytes (hESC-CMs) can improve the function of infarcted hearts, but two critical issues related to their electrophysiological behaviour in vivo remain unresolved. First, the risk of arrhythmias following hESC-CM transplantation in injured hearts has not been determined. Second, the electromechanical integration of hESC-CMs in injured hearts has not been demonstrated, so it is unclear whether these cells improve contractile function directly through addition of new force-generating units. Here we use a guinea-pig model to show that hESC-CM grafts in injured hearts protect against arrhythmias and can contract synchronously with host muscle. Injured hearts with hESC-CM grafts show improved mechanical function and a significantly reduced incidence of both spontaneous and induced ventricular tachycardia. To assess the activity of hESC-CM grafts in vivo, we transplanted hESC-CMs expressing the genetically encoded calcium sensor, GCaMP3 (refs 4, 5). By correlating the GCaMP3 fluorescent signal with the host ECG, we found that grafts in uninjured hearts have consistent 1:1 host–graft coupling. Grafts in injured hearts are more heterogeneous and typically include both coupled and uncoupled regions. Thus, human myocardial grafts meet physiological criteria for true heart regeneration, providing support for the continued development of hESC-based cardiac therapies for both mechanical and electrical repair. PMID:22864415

  14. Lkb1 Deletion Promotes Ectopic Lipid Accumulation in Muscle Progenitor Cells and Mature Muscles

    PubMed Central

    SHAN, TIZHONG; ZHANG, PENGPENG; BI, PENGPENG; KUANG, SHIHUAN

    2015-01-01

    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 MyodCre and Lkb1flox/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. PMID:25251157

  15. Muscle stem cells contribute to myofibers in sedentary adult mice

    PubMed Central

    Keefe, Alexandra C.; Lawson, Jennifer A.; Flygare, Steven D.; Fox, Zachary D.; Colasanto, Mary P.; Mathew, Sam J.; Yandell, Mark; Kardon, Gabrielle

    2015-01-01

    Skeletal muscle is essential for mobility, stability, and whole body metabolism, and muscle loss, for instance during sarcopenia, has profound consequences. Satellite cells (muscle stem cells) have been hypothesized, but not yet demonstrated, to contribute to muscle homeostasis and a decline in their contribution to myofiber homeostasis to play a part in sarcopenia. To test their role in muscle maintenance, we genetically labeled and ablated satellite cells in adult sedentary mice. We demonstrate via genetic lineage experiments that even in the absence of injury, satellite cells contribute to myofibers in all adult muscles, although the extent and timing differs. However, genetic ablation experiments showed that satellite cells are not globally required to maintain myofiber cross-sectional area of uninjured adult muscle. PMID:25971691

  16. 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.

  17. 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.

  18. 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.

  19. Exclusive skeletal muscle correction does not modulate dystrophic heart disease in the aged mdx model of Duchenne cardiomyopathy

    PubMed Central

    Wasala, Nalinda B.; Bostick, Brian; Yue, Yongping; Duan, Dongsheng

    2013-01-01

    Duchenne muscular dystrophy (DMD) is characterized by severe degeneration and necrosis of both skeletal and cardiac muscle. While many experimental therapies have shown great promise in treating skeletal muscle disease, an effective therapy for Duchenne cardiomyopathy remains a challenge in large animal models and human patients. The current views on cardiac consequences of skeletal muscle-centered therapy are controversial. Studies performed in young adult mdx mice (a mild DMD mouse model) have yielded opposing results. Since mdx mice do not develop dystrophic cardiomyopathy until ≥21 months of age, we reasoned that old mdx mice may represent a better model to assess the impact of skeletal muscle rescue on dystrophic heart disease. Here, we aged skeletal muscle-specific micro-dystrophin transgenic mdx mice to 23 months and examined the cardiac phenotype. As expected, transgenic mdx mice had minimal skeletal muscle disease and they also outperformed original mdx mice on treadmill running. On cardiac examination, the dystrophin-null heart of transgenic mdx mice displayed severe cardiomyopathy matching that of non-transgenic mdx mice. Specifically, both the strains showed similar heart fibrosis and cardiac function deterioration in systole and diastole. Cardiac output and ejection fraction were also equally compromised. Our results suggest that skeletal muscle rescue neither aggravates nor alleviates cardiomyopathy in aged mdx mice. These findings underscore the importance of treating both skeletal and cardiac muscles in DMD therapy. PMID:23459935

  20. Thermoregulatory uncoupling in heart muscle mitochondria: involvement of the ATP/ADP antiporter and uncoupling protein.

    PubMed

    Simonyan, R A; Skulachev, V P

    1998-09-25

    Possible involvement of the ATP/ADP antiporter and uncoupling protein (UCP) in thermoregulatory uncoupling of oxidative phosphorylation in heart muscle has been studied. To this end, effects of carboxyatractylate (cAtr) and GDP, specific inhibitors of the antiporter and UCP, on the membrane potential of the oligomycin-treated mitochondria from cold-exposed (6 degrees C, 48 h) and control rats have been measured. It is found that cAtr increases the membrane potential level in both cold-exposed and non-exposed groups, the effect being strongly enhanced by cooling. As for GDP, it is effective only in mitochondria from the cold-exposed rats. In these mitochondria, the coupling effect of GDP is smaller than that of cAtr. CDP, which does not interact with UCP, is without any influence on membrane potential. The cold exposure is found to increase the uncoupling efficiency of added natural (palmitate) or artificial (SF6847) uncouplers, the increase being cAtr- and GDP-sensitive in the case of palmitate. The fatty acid-free bovine serum albumin enhances delta psi in both cold-exposed and control groups, the effect being much larger in the former case. It is concluded that in heart muscle mitochondria the ATP/ADP antiporter is responsible for the 'mild uncoupling' under normal conditions and for major portion of the thermoregulatory uncoupling in the cold whereas the rest of thermoregulatory uncoupling is served by UCP (presumably by UCP2 since the UCP2 mRNA level is shown to strongly increase in rat heart muscle under the cold exposure conditions used). PMID:9771898

  1. Effect of endurance training and/or fish oil supplemented diet on cytoplasmic fatty acid binding protein in rat skeletal muscles and heart.

    PubMed

    Clavel, Stéphan; Farout, L; Briand, M; Briand, Y; Jouanel, P

    2002-07-01

    Endurance training and/or a fish oil supplemented diet affect cytoplasmic fatty acid binding protein (FABP(c)) content in rat skeletal muscles and heart. After 8 weeks of swimming, trained rats exhibited higher FABP(c) content in the extensor digitorum longus (EDL) and in the gastrocnemius than did control rats (30%). The FABP(c) increase was associated with an increase of citrate synthase activity (85% and 93%, respectively, in the two muscles), whereas lactate dehydrogenase activity decreased significantly. In contrast, in the soleus and in the heart we did not observe any effect of exercise either on FABP(c) or on the metabolic profile. Therefore, increasing oxidative capacities of muscle by exercise resulted in a concomitant increase of the FABP(c) content. Giving a polyunsaturated fatty acid (omega-3) supplemented diet for eight weeks induced a large rise of the FABP(c) in EDL (300%), gastrocnemius (250%), soleus (50%) and heart (15%) without a concurrent accumulation of intramuscular triglycerides or modification of the citrate synthase activity, suggesting that polyunsaturated fatty acids may increase FABP(c) content by up-regulating fatty acid metabolism genes via peroxisome proliferator-activated receptor alpha activation. Endurance trained rats fed with an omega-3 diet had similar FABP(c) content in the gastrocnemius muscle when compared to sedentary omega-3 fed rats, whereas an additive effect of exercise and diet was observed in the EDL. The FABP(c) in the soleus and in the heart of rats fed with omega-3 supplements remained constant whether rats performed exercise or not. As a result, both exercise and omega-3-enriched diet influenced FABP(c) content in muscle. These two physiological treatments presumably acted on FABP(c) content by increasing fatty acid flux within the cell. PMID:12111278

  2. 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

  3. Lack of β2-adrenoceptors aggravates heart failure-induced skeletal muscle myopathy in mice

    PubMed Central

    Voltarelli, Vanessa A; Bechara, Luiz RG; Bacurau, Aline VN; Mattos, Katt C; Dourado, Paulo MM; Bueno, Carlos R; Casarini, Dulce E; Negrao, Carlos E; Brum, Patricia C

    2014-01-01

    Skeletal myopathy is a hallmark of heart failure (HF) and has been associated with a poor prognosis. HF and other chronic degenerative diseases share a common feature of a stressed system: sympathetic hyperactivity. Although beneficial acutely, chronic sympathetic hyperactivity is one of the main triggers of skeletal myopathy in HF. Considering that β2-adrenoceptors mediate the activity of sympathetic nervous system in skeletal muscle, we presently evaluated the contribution of β2-adrenoceptors for the morphofunctional alterations in skeletal muscle and also for exercise intolerance induced by HF. Male WT and β2-adrenoceptor knockout mice on a FVB genetic background (β2KO) were submitted to myocardial infarction (MI) or SHAM surgery. Ninety days after MI both WT and β2KO mice presented to cardiac dysfunction and remodelling accompanied by significantly increased norepinephrine and epinephrine plasma levels, exercise intolerance, changes towards more glycolytic fibres and vascular rarefaction in plantaris muscle. However, β2KO MI mice displayed more pronounced exercise intolerance and skeletal myopathy when compared to WT MI mice. Skeletal muscle atrophy of infarcted β2KO mice was paralleled by reduced levels of phosphorylated Akt at Ser 473 while increased levels of proteins related with the ubiquitin-–proteasome system, and increased 26S proteasome activity. Taken together, our results suggest that lack of β2-adrenoceptors worsen and/or anticipate the skeletal myopathy observed in HF. PMID:24629015

  4. 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

  5. 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

  6. 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

  7. 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. PMID:25460248

  8. 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.

  9. 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

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

    PubMed

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

    2016-01-01

    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

  11. 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

  12. Cardiac repair and regeneration: the Rubik's cube of cell therapy for heart disease.

    PubMed

    Boudoulas, Konstantinos D; Hatzopoulos, Antonis K

    2009-01-01

    Acute ischemic injury and chronic cardiomyopathies damage healthy heart tissue. Dead cells are gradually replaced by a fibrotic scar, which disrupts the normal electromechanical continuum of the ventricular muscle and compromises its pumping capacity. Recent studies in animal models of ischemic cardiomyopathy suggest that transplantation of various stem cell preparations can improve heart recovery after injury. The first clinical trials in patients produced some encouraging results, showing modest benefits. Most of the positive effects are probably because of a favorable paracrine influence of stem cells on the disease microenvironment. Stem cell therapy attenuates inflammation, reduces apoptosis of surrounding cells, induces angiogenesis, and lessens the extent of fibrosis. However, little new heart tissue is formed. The current challenge is to find ways to improve the engraftment, long-term survival and appropriate differentiation of transplanted stem cells within the cardiovascular tissue. Hence, there has been a surge of interest in pluripotent stem cells with robust cardiogenic potential, as well as in the inherent repair and regenerative mechanisms of the heart. Recent discoveries on the biology of adult stem cells could have relevance for cardiac regeneration. Here, we discuss current developments in the field of cardiac repair and regeneration, and present our ideas about the future of stem cell therapy. PMID:19553696

  13. 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.

  14. Sympathetic nerve responses to muscle contraction and stretch in ischemic heart failure.

    PubMed

    Koba, Satoshi; Xing, Jihong; Sinoway, Lawrence I; Li, Jianhua

    2008-01-01

    Congestive heart failure (CHF) induces abnormal regulation of peripheral blood flow during exercise. Previous studies have suggested that a reflex from contracting muscle is disordered in this disease. However, there has been very little investigation of the muscle reflex regulating sympathetic outflows in CHF. Myocardial infarction (MI) was induced by the coronary artery ligation in rats. Echocardiography was performed to determine fractional shortening (FS), an index of the left ventricular function. We examined renal and lumbar sympathetic nerve activities (RSNA and LSNA, respectively) during 1-min repetitive (1- to 4-s stimulation to relaxation) contraction or stretch of the triceps surae muscles. During these interventions, the RSNA and LSNA responded synchronously as tension was developed. The RSNA and LSNA responses to contraction were significantly greater in MI rats (n = 13) with FS <30% than in control animals (n = 13) with FS >40% (RSNA: +49 +/- 7 vs. +19 +/- 4 a.u., P < 0.01; LSNA: +28 +/- 7 vs. +8 +/- 2 a.u., P < 0.01) at the same tension development. Stretch also increased the RSNA and LSNA to a larger degree in MI (n = 13) than in control animals (n = 13) (RSNA: +36 +/- 6 vs. +19 +/- 3 a.u., P < 0.05; LSNA: +24 +/- 3 vs. +9 +/- 2 a.u., P < 0.01). The data demonstrate that CHF exaggerates sympathetic nerve responses to muscle contraction as well as stretch. We suggest that muscle afferent-mediated sympathetic outflows contribute to the abnormal regulation of peripheral blood flow seen during exercise in CHF. PMID:17965282

  15. 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

  16. 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

  17. 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

  18. Cholinesterases of heart muscle. Characterization of multiple enzymes using kinetics of irreversible organophosphorus inhibition.

    PubMed

    Chemnitius, J M; Chemnitius, G C; Haselmeyer, K H; Kreuzer, H; Zech, R

    1992-02-18

    Cholinesterases of porcine left ventricular heart muscle were characterized with respect to substrate specificity and inhibition kinetics with organophosphorus inhibitors N,N'-di-isopropyl-phosphorodiamidic fluoride (Mipafox), di-isopropylphosphorofluoridate (DFP), and diethyl p-nitro-phenyl phosphate (Paraoxon). Total myocardial choline ester hydrolysing activity (234 nmol/min/g wet wt with 1.5 mM acetylthiocholine, ASCh; 216 nmol/min/g with 30 mM butyrylthiocholine, BSCh) was irreversibly and covalently inhibited by a wide range of inhibitor concentrations and, using weighted least-squares non-linear curve fitting, residual activities as determined with four different substrates in each case were fitted to a sum of up to four exponential functions. Quality of curve fitting as assessed by the sum of squares reached its optimum on the basis of a three component model, thus, indicating the presence of three different enzymes taking part in choline ester hydrolysis. Final classification of heart muscle cholinesterases was obtained according to both substrate hydrolysis patterns with ASCh, BSCh, acetyl-beta-methylthiocholine and propionylthiocholine, and second-order rate constants for the reaction with organophosphorus inhibitors Mipafox, DFP, and Paraoxon. One choline ester-hydrolysing enzyme was identified as acetylcholinesterase (EC 3.1.1.7), and one as butyrylcholinesterase (EC 3.1.1.8). The third enzyme with relative resistance to organophosphorus inhibition was classified as atypical cholinesterase. PMID:1540236

  19. 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. PMID:26742650

  20. 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

  1. 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

  2. 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. PMID:26892967

  3. 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

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

    PubMed Central

    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

  5. 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

  6. 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.

  7. 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

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

    PubMed

    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

  9. 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

  10. Laser-patterned stem-cell bridges in a cardiac muscle model for on-chip electrical conductivity analyses

    PubMed Central

    Ma, Zhen; Liu, Qiuying; Liu, Honghai; Yang, Huaxiao; Yun, Julie X.; Eisenberg, Carol; Borg, Thomas K.; Xu, Meifeng; Gao, Bruce Z.

    2012-01-01

    Following myocardial infarction there is an irreversible loss of cardiomyocytes that results in the alteration of electrical propagation in the heart. Restoration of functional electrical properties of the damaged heart muscle is essential to recover from the infarction. While there are a few reports that demonstrate that fibroblasts can form junctions that transmit electrical signals, a potential alternative using the injection of stem cells has emerged as a promising cellular therapy; however, stem-cell electrical conductivity within the cardiac muscle fiber is unknown. In this study, an in vitro cardiac muscle model was established on an MEA-based biochip with multiple cardiomyocytes that mimic cardiac tissue structure. Using a laser beam, stem cells were inserted adjacent to each muscle fiber (cell bridge model) and allowed to form cell-cell contact as determined by the formation of gap junctions. The electrical conductivity of stem cells was assessed and compared with the electrical conductivities of cardiomyocytes and fibroblasts. Results showed that stem cell-myocyte contacts exhibited higher and more stable conduction velocities than myocyte-fibroblast contacts, which indicated that stem cells have higher electrical compatibility with native cardiac muscle fibers than cardiac fibroblasts. PMID:22170399

  11. Acute phase lipocalin Ex-FABP is involved in heart development and cell survival.

    PubMed

    Gentili, C; Tutolo, G; Zerega, B; Di Marco, E; Cancedda, R; Cancedda, F Descalzi

    2005-03-01

    Ex-FABP is an extracellular fatty acid binding protein, expressed during chicken embryo development in cartilage, muscle fibers, and blood granulocytes. Transfection of chondrocytes and myoblasts with anti-sense Ex-FABP cDNA results in inhibition of cell proliferation and apoptosis induction. Ex-FABP expression is dramatically enhanced by inflammatory stimuli and in pathological conditions. In this paper, by in situ whole mount and immunohistochemistry analysis we show that, at early developmental stage, Ex-FABP is diffuse in all tissues of chick embryos. Particularly high level of transcript and protein are expressed in the heart. During acute phase response (APR) induced by endotoxin LPS injection, a marked increase of Ex-FABP mRNA was observed in embryos, highest Ex-FABP expression being in heart and liver. To investigate in vivo the biological role of Ex-FABP, we have directly microinjected chicken embryos with antibody against Ex-FABP. Almost 70% of chicken embryos died and the target tissue was the heart. We detected in heart of the treated embryos a significant increase of apoptotic cells and high level of fatty acids. We propose that the accumulation of fatty acid, specific ligand of Ex-FABP, in the cell microenvironment is responsible of heart cell death, and we suggest that Ex-FABP may act as a survival protein by playing a role as scavenger for fatty acids. PMID:15455366

  12. Shared signaling systems in myeloid cell-mediated muscle regeneration

    PubMed Central

    Tidball, James G.; Dorshkind, Kenneth; Wehling-Henricks, Michelle

    2014-01-01

    Much of the focus in muscle regeneration has been placed on the identification and delivery of stem cells to promote regenerative capacity. As those efforts have advanced, we have learned that complex features of the microenvironment in which regeneration occurs can determine success or failure. The immune system is an important contributor to that complexity and can determine the extent to which muscle regeneration succeeds. Immune cells of the myeloid lineage play major regulatory roles in tissue regeneration through two general, inductive mechanisms: instructive mechanisms that act directly on muscle cells; and permissive mechanisms that act indirectly to influence regeneration by modulating angiogenesis and fibrosis. In this article, recent discoveries that identify inductive actions of specific populations of myeloid cells on muscle regeneration are presented, with an emphasis on how processes in muscle and myeloid cells are co-regulated. PMID:24595286

  13. 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

  14. Current Status and Perspectives in Stem Cell Therapy for Heart

    PubMed Central

    Lin, Fen-Chiung; Chen, Wen-Pin; Chu, Pao-Hsien; Shyu, Kou-Gi; Wen, Ming-Shien

    2014-01-01

    For most patients, the prognosis of heart failure remains poor despite therapeutic advancement in recent decades. The option of cardiac transplantation is high risk and limited by a shortage of donors. Traditionally, the heart had been considered a terminally differentiated organ incapable of regeneration. However, numerous preclinical and clinical studies have been performed since the first report of cell therapy in heart failure using skeletal myoblasts in 2001. These investigations looked at the promising potential and use of several kinds of stem cells, which could some day dramatically alter the understanding of the regenerative capacity of the heart. To date, although there is no existing cardiac cell therapy that has been conclusively reported to be effective, stem cell-related cardiomyocyte regeneration strategies have become significant areas of research in modern cardiovascular medicine. In this review, we outline a variety of common cell sources, surface biomarkers of stem cells, and provide information related to cardiac cell therapy clinical trials. PMID:27122815

  15. ASIC proteins regulate smooth muscle cell migration.

    PubMed

    Grifoni, Samira C; Jernigan, Nikki L; Hamilton, Gina; Drummond, Heather A

    2008-03-01

    The purpose of the present study was to investigate Acid Sensing Ion Channel (ASIC) protein expression and importance in cellular migration. We recently demonstrated that Epithelial Na(+)Channel (ENaC) proteins are required for vascular smooth muscle cell (VSMC) migration; however, the role of the closely related ASIC proteins has not been addressed. We used RT-PCR and immunolabeling to determine expression of ASIC1, ASIC2, ASIC3 and ASIC4 in A10 cells. We used small interference RNA to silence individual ASIC expression and determine the importance of ASIC proteins in wound healing and chemotaxis (PDGF-bb)-initiated migration. We found ASIC1, ASIC2, and ASIC3, but not ASIC4, expression in A10 cells. ASIC1, ASIC2, and ASIC3 siRNA molecules significantly suppressed expression of their respective proteins compared to non-targeting siRNA (RISC) transfected controls by 63%, 44%, and 55%, respectively. Wound healing was inhibited by 10, 20, and 26% compared to RISC controls following suppression of ASIC1, ASIC2, and ASIC3, respectively. Chemotactic migration was inhibited by 30% and 45%, respectively, following suppression of ASIC1 and ASIC3. ASIC2 suppression produced a small, but significant, increase in chemotactic migration (4%). Our data indicate that ASIC expression is required for normal migration and may suggest a novel role for ASIC proteins in cellular migration. PMID:17936312

  16. Smooth muscle cell calcium activation mechanisms

    PubMed Central

    Berridge, Michael J

    2008-01-01

    Smooth muscle cell (SMC) contraction is controlled by the Ca2+ and Rho kinase signalling pathways. While the SMC Rho kinase system seems to be reasonably constant, there is enormous variation with regard to the mechanisms responsible for generating Ca2+ signals. One way of dealing with this diversity is to consider how this system has been adapted to control different SMC functions. Phasic SMCs (vas deferens, uterus and bladder) rely on membrane depolarization to drive Ca2+ influx across the plasma membrane. This depolarization can be induced by neurotransmitters or through the operation of a membrane oscillator. Many tonic SMCs (vascular, airway and corpus cavernosum) are driven by a cytosolic Ca2+ oscillator that generates periodic pulses of Ca2+. A similar oscillator is present in pacemaker cells such as the interstitial cells of Cajal (ICCs) and atypical SMCs that control other tonic SMCs (gastrointestinal, urethra, ureter). The changes in membrane potential induced by these cytosolic oscillators does not drive contraction directly but it functions to couple together individual oscillators to provide the synchronization that is a characteristic feature of many tonic SMCs. PMID:18787034

  17. Effects of dichloroacetate on the metabolism of glucose, pyruvate, acetate, 3-hydroxybutyrate and palmitate in rat diaphragm and heart muscle in vitro and on extraction of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo.

    PubMed

    McAllister, A; Allison, S P; Randle, P J

    1973-08-01

    1. The extractions of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo were calculated from measurements of their arterial and coronary sinus blood concentration. Elevation of plasma free fatty acid concentrations by infusion of intralipid and heparin resulted in increased extraction of free fatty acids and diminished extractions of glucose, lactate and pyruvate by the heart. It is suggested that metabolism of free fatty acids by the heart in vivo, as in vitro, may impair utilization of these substrates. These effects of elevated plasma free fatty acid concentrations on extractions by the heart in vivo were reversed by injection of dichloroacetate, which also improved extraction of lactate and pyruvate by the heart in vivo in alloxan diabetes. 2. Sodium dichloroacetate increased glucose oxidation and pyruvate oxidation in hearts from fed normal or alloxan-diabetic rats perfused with glucose and insulin. Dichloroacetate inhibited oxidation of acetate and 3-hydroxybutyrate and partially reversed inhibitory effects of these substrates on the oxidation of glucose. In rat diaphragm muscle dichloroacetate inhibited oxidation of acetate, 3-hydroxybutyrate and palmitate and increased glucose oxidation and pyruvate oxidation in diaphragms from alloxan-diabetic rats. Dichloroacetate increased the rate of glycolysis in hearts perfused with glucose, insulin and acetate and evidence is given that this results from a lowering of the citrate concentration within the cell, with a consequent activation of phosphofructokinase. 3. In hearts from normal rats perfused with glucose and insulin, dichloroacetate increased cell concentrations of acetyl-CoA, acetylcarnitine and glutamate and lowered those of aspartate and malate. In perfusions with glucose, insulin and acetate, dichloroacetate lowered the cell citrate concentration without lowering the acetyl-CoA or acetylcarnitine concentrations. Measurements of specific radioactivities of acetyl-CoA, acetylcarnitine

  18. VAMP2 is expressed in muscle satellite cells and up-regulated during muscle regeneration.

    PubMed

    Tajika, Yuki; Sato, Mahito; Murakami, Tohru; Takata, Kuniaki; Yorifuji, Hiroshi

    2007-06-01

    Membrane trafficking is one of the most important mechanisms involved in the establishment and maintenance of the forms and functions of the cell. However, it is poorly understood in skeletal muscle cells. In this study, we have focused on vesicle-associated membrane proteins (VAMPs), which are components of the vesicle docking and fusion complex, and have performed immunostaining to investigate the expression of VAMPs in rat skeletal muscle tissue. We have found that VAMP2, but not VAMP1 or VAMP3, is expressed in satellite cells. VAMP2 is also expressed in myofibers in the soleus muscle and nerve endings. This is consistent with previous studies in which VAMP2 has been shown to regulate GLUT4 trafficking in slow-twitch myofibers in soleus muscle and neurotransmitter release in nerve endings. As satellite cells are quiescent myogenic cells, the expression of VAMP2 has further been examined in regenerating muscles after injury by the snake venom, cardiotoxin; we have observed enhanced expression of VAMP2 in immature myotubes with a peak at 3 days after injury. Our findings suggest that VAMP2 plays roles in quiescent satellite cells and is involved in muscle regeneration. The nature of the material transported in the VAMP2-bearing vesicles in satellite cells and myotubes is still under investigation. PMID:17468895

  19. Uncoupling effect of fatty acids on heart muscle mitochondria and submitochondrial particles.

    PubMed

    Dedukhova, V I; Mokhova, E N; Skulachev, V P; Starkov, A A; Arrigoni-Martelli, E; Bobyleva, V A

    1991-12-16

    The effect of ATP/ADP-antiporter inhibitors on palmitate-induced uncoupling was studied in heart muscle mitochondria and inside-out submitochondrial particles. In both systems palmitate is found to decrease the respiration-generated membrane potential. In mitochondria, this effect is specifically abolished by carboxyatractylate (CAtr) a non-penetrating inhibitor of antiporter. In submitochondrial particles, CAtr does not abolish the palmitate-induced potential decrease. At the same time, bongkrekic acid, a penetrating inhibitor of the antiporter, suppresses the palmitate effect on the potential both in mitochondria and particles. Palmitoyl-CoA which is known to inhibit the antiporter in mitochondria as well as in particles decreases the palmitate uncoupling efficiency in both these systems. These data are in agreement with the hypothesis that the ATP/ADP-antiporter is involved in the action of free fatty acids as natural uncouplers of oxidative phosphorylation. PMID:1765167

  20. 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 ...

  1. What Causes Heart Block?

    MedlinePlus

    ... or inflammation of the heart muscle. Heart failure . Rheumatic (roo-MAT-ik) fever. Cardiomyopathy (KAR-de-o-mi-OP-a-the), or heart muscle diseases. Other diseases may increase the risk of heart ...

  2. 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. PMID:27198673

  3. Caveolar nanospaces in smooth muscle cells

    PubMed Central

    Gherghiceanu, Mihaela; Popescu, L M

    2006-01-01

    Caveolae, specialized membrane nanodomains, have a key role in signaling processes, including calcium handling in smooth muscle cells (SMC). We explored the three-dimensional (3D) architecture of peripheral cytoplasmic space at the nanoscale level and the close spatial relationships between caveolae, sarcoplasmic reticulum (SR), and mitochondria, as ultrastructural basis for an excitation-contraction coupling system and, eventually, for excitation - transcription coupling. About 150 electron micrographs of SMC showed that superficial SR and peripheral mitochondria are rigorously located along the caveolar domains of plasma membrane, alternating with plasmalemmal dense plaques. Electron micrographs made on serial ultrathin sections were digitized, then computer-assisted organellar profiles were traced on images, and automatic 3D reconstruction was obtained using the ‘Reconstruct’ software. The reconstruction was made for 1 μm3 in rat stomach (muscularis mucosae) and 10 μm3 in rat urinary bladder (detrusor smooth muscle). The close appositions (about 15 nm distance) of caveolae, peripheral SR, and mitochondria create coherent cytoplasmic nanoscale subdomains. Apparently, 80% of caveolae establish close contacts with SR and about 10% establish close contacts with mitochondria in both types of SMC. Thus, our results show that caveolae and peripheral SR build Ca2+release units in which mitochondria often could play a part. The caveolae-SR couplings occupy 4.19% of the cellular volume in stomach and 3.10% in rat urinary bladder, while caveolae-mitochondria couplings occupy 3.66% and 3.17%, respectively. We conclude that there are strategic caveolae-SR or caveolae-mitochondria contacts at the nanoscale level in the cortical cytoplasm of SMC, presumably responsible for a vectorial control of free Ca2+ cytoplasmic concentrations in definite nanospaces. This may account for slective activation of specific Ca2+ signaling pathways. PMID:16796817

  4. 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

  5. Immunopathology of experimental Chagas' disease: binding of T cells to Trypanosoma cruzi-infected heart tissue.

    PubMed Central

    Mortatti, R C; Maia, L C; de Oliveira, A V; Munk, M E

    1990-01-01

    The immunopathology of Chagas' disease was studied in the experimental model of chronic infection in C57BL/10JT or mice. Sublethal infection with Trypanosoma cruzi, Y strain, induced specific antibodies and a delayed hypersensitivity response to parasite antigens. Mice developed chronic chagasic myocarditis but not skeletal muscle myositis. Binding of T cells to infected heart tissue was investigated during short-term cocultivation of lymphocytes with heart cryostat sections. T cells from infected mice and from normal controls bound equally to myocardium and liver sections from both infected and normal mice. A search in depth was attempted with cells heavily tagged with 99mTc. Labeled T cells from chagasic mice bound to both normal and infected myocardium slices. 99mTc-labeled T cells from controls gave the same binding values. Glass-adherent spleen cells behaved identically to T cells. Prior treatment of the tissue with serum from chronically infected mice did not increase the number of binding cells. Peritoneal macrophages tagged with 99mTc-sulfur colloid also bound to infected myocardium slices. The binding of macrophages was not changed by pretreatment of infected tissue with anti-T, cruzi antibodies. In short, this work did not detect any population of T cells or macrophages which could bind specifically to infected heart tissue to initiate an autoreactive process. Images PMID:2228230

  6. 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

  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. PMID:25813541

  8. Fetal stem cells and skeletal muscle regeneration: a therapeutic approach.

    PubMed

    Pozzobon, Michela; Franzin, Chiara; Piccoli, Martina; De Coppi, Paolo

    2014-01-01

    More than 40% of the body mass is represented by muscle tissue, which possesses the innate ability to regenerate after damage through the activation of muscle-specific stem cells, namely satellite cells. Muscle diseases, in particular chronic degenerative states of skeletal muscle such as dystrophies, lead to a perturbation of the regenerative process, which causes the premature exhaustion of satellite cell reservoir due to continuous cycles of degeneration/regeneration. Nowadays, the research is focused on different therapeutic approaches, ranging from gene and cell to pharmacological therapy, but still there is no definitive cure in particular for genetic muscle disease. Keeping this in mind, in this article, we will give special consideration to muscle diseases and the use of fetal derived stem cells as a new approach for therapy. Cells of fetal origin, from cord blood to placenta and amniotic fluid, can be easily obtained without ethical concern, expanded and differentiated in culture, and possess immune-modulatory properties. The in vivo approach in animal models can be helpful to study the mechanism underneath the operating principle of the stem cell reservoir, namely the niche, which holds great potential to understand the onset of muscle pathologies. PMID:25221507

  9. Neurotrophin and Neurotrophin Receptors in Vascular Smooth Muscle Cells

    PubMed Central

    Donovan, Michael J.; Miranda, Rajesh C.; Kraemer, Rosemary; McCaffrey, Timothy A.; Tessarollo, Lino; Mahadeo, Debbie; Sharif, Setareh; Kaplan, David R.; Tsoulfas, Pantelis; Parada, Luis; Toran-Allerand, C. Dominique; Hajjar, David P.; Hempstead, Barbara L.

    1995-01-01

    The neurotrophins, a family of related polypeptide growth factors including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3 and NT-4/5 promote the survival and differentiation of distinctive sets of embryonic neurons. Here we define a new functional role for neurotrophins, as autocrine or local paracrine mediators of vascular smooth muscle cell migration. We have identified neurotrophins, and their cognate receptors, the trk tyrosine kinases, in human and rat vascular smooth muscle cells in vivo. In vitro, cultured human smooth muscle cells express BDNF; NT-3; and trk A, B, and C Similarly, rat smooth muscle cells expressed all three trk receptors as well as all four neurotrophins. Moreover, NGF induces cultured human smooth muscle cell migration at subnanomolar concentrations. In the rat aortic balloon deendothelialization model of vascular injury, the expression of NGF, BDNF, and their receptors trk A and trk B increased dramatically in the area of injury within 3 days and persisted during the formation of the neointima. In human coronary atherosclerotic lesions, BDNF, NT-3, and NT-4/5, and the trk B and trk C receptors could be demonstrated in smooth muscle cells. These findings suggest that neurotrophins play an important role in regulating the response of vascular smooth muscle cells to injury. ImagesFigure 1Figure 2Figure 3Figure 5Figure 6Figure 7Figure 8 PMID:7639328

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

    PubMed Central

    Fukada, So-ichiro; Ma, Yuran; Ohtani, Takuji; Watanabe, Yoko; Murakami, Satoshi; Yamaguchi, Masahiko

    2013-01-01

    Skeletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal muscle biology. Many studies have demonstrated proteins expressed by satellite cells, including Pax7, M-cadherin, Cxcr4, syndecan3/4, and c-met. To further characterize satellite cells, we established a method to directly isolate satellite cells using a monoclonal antibody, SM/C-2.6. Using SM/C-2.6 and microarrays, we measured the genes expressed in quiescent satellite cells and demonstrated that Hesr3 may complement Hesr1 in generating quiescent satellite cells. Although Hesr1- or Hesr3-single knockout mice show a normal skeletal muscle phenotype, including satellite cells, Hesr1/Hesr3-double knockout mice show a gradual decrease in the number of satellite cells and increase in regenerative defects dependent on satellite cell numbers. We also observed that a mouse's genetic background affects the regenerative capacity of its skeletal muscle and have established a line of DBA/2-background mdx mice that has a much more severe phenotype than the frequently used C57BL/10-mdx mice. The phenotype of DBA/2-mdx mice also seems to depend on the function of satellite cells. In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results. The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized. In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders. PMID:24273513

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

    PubMed

    Valero, M Carmen; Huntsman, Heather D; Liu, Jianming; Zou, Kai; Boppart, Marni D

    2012-01-01

    Eccentric, or lengthening, contractions result in injury and subsequently stimulate the activation and proliferation of satellite stem cells which are important for skeletal muscle regeneration. The discovery of alternative myogenic progenitors in skeletal muscle raises the question as to whether stem cells other than satellite cells accumulate in muscle in response to exercise and contribute to post-exercise repair and/or growth. In this study, stem cell antigen-1 (Sca-1) positive, non-hematopoetic (CD45⁻) cells were evaluated in wild type (WT) and α7 integrin transgenic (α7Tg) mouse muscle, which is resistant to injury yet liable to strain, 24 hr following a single bout of eccentric exercise. Sca-1⁺CD45⁻ stem cells were increased 2-fold in WT muscle post-exercise. The α7 integrin regulated the presence of Sca-1⁺ cells, with expansion occurring in α7Tg muscle and minimal cells present in muscle lacking the α7 integrin. Sca-1⁺CD45⁻ cells isolated from α7Tg muscle following exercise were characterized as mesenchymal-like stem cells (mMSCs), predominantly pericytes. In vitro multiaxial strain upregulated mMSC stem cells markers in the presence of laminin, but not gelatin, identifying a potential mechanistic basis for the accumulation of these cells in muscle following exercise. Transplantation of DiI-labeled mMSCs into WT muscle increased Pax7⁺ cells and facilitated formation of eMHC⁺DiI⁻ fibers. This study provides the first demonstration that mMSCs rapidly appear in skeletal muscle in an α7 integrin dependent manner post-exercise, revealing an early event that may be necessary for effective repair and/or growth following exercise. The results from this study also support a role for the α7 integrin and/or mMSCs in molecular- and cellular-based therapeutic strategies that can effectively combat disuse muscle atrophy. PMID:22253772

  12. 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

  13. 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

  14. Adult Bone Marrow-Derived Stem Cells in Muscle Connective Tissue and Satellite Cell Niches

    PubMed Central

    Dreyfus, Patrick A.; Chretien, Fabrice; Chazaud, Bénédicte; Kirova, Youlia; Caramelle, Philippe; Garcia, Luis; Butler-Browne, Gillian; Gherardi, Romain K.

    2004-01-01

    Skeletal muscle includes satellite cells, which reside beneath the muscle fiber basal lamina and mainly represent committed myogenic precursor cells, and multipotent stem cells of unknown origin that are present in muscle connective tissue, express the stem cell markers Sca-1 and CD34, and can differentiate into different cell types. We tracked bone marrow (BM)-derived stem cells in both muscle connective tissue and satellite cell niches of irradiated mice transplanted with green fluorescent protein (GFP)-expressing BM cells. An increasing number of GFP+ mononucleated cells, located both inside and outside of the muscle fiber basal lamina, were observed 1, 3, and 6 months after transplantation. Sublaminal cells expressed unambiguous satellite cell markers (M-cadherin, Pax7, NCAM) and fused into scattered GFP+ muscle fibers. In muscle connective tissue there were GFP+ cells located close to blood vessels that expressed the ScaI or CD34 stem-cell antigens. The rate of settlement of extra- and intralaminal compartments by BM-derived cells was compatible with the view that extralaminal cells constitute a reservoir of satellite cells. We conclude that both muscle satellite cells and stem cell marker-expressing cells located in muscle connective tissue can derive from BM in adulthood. PMID:14982831

  15. Progenitors of skeletal muscle satellite cells express the muscle determination gene, MyoD

    PubMed Central

    Kanisicak, Onur; Mendez, Julio J.; Yamamoto, Shoko; Yamamoto, Masakazu; Goldhamer, David J.

    2009-01-01

    Satellite cells are tissue-specific stem cells responsible for skeletal muscle growth and regeneration. Although satellite cells were identified almost 50 years ago, the identity of progenitor populations from which they derive remains controversial. We developed MyoDiCre knockin mice, and used Cre/lox lineage analysis to determine whether satellite cell progenitors express MyoD, a marker of myogenic commitment. Recombination status of satellite cells was determined by confocal microscopy of isolated muscle fibers and by electron microscopic observation of muscle tissue fixed immediately following isolation, using R26R-EYFP and R26R (β-gal) reporter mice, respectively. We show that essentially all adult satellite cells associated with limb and body wall musculature, as well as the diaphragm and extraocular muscles, originate from MyoD+ progenitors. Neonatal satellite cells were Cre-recombined, but only a small minority exhibited ongoing Cre expression, indicating that most satellite cells had expressed MyoD prenatally. We also show that satellite cell development in MyoD-null mice is not due to functional compensation by MyoD non-expressing lineages. The results suggest that satellite cells are derived from committed myogenic progenitors, irrespective of the anatomical location, embryological origin, or physiological properties of associated musculature. PMID:19464281

  16. TRIM32 regulates skeletal muscle stem cell differentiation and is necessary for normal adult muscle regeneration.

    PubMed

    Nicklas, Sarah; Otto, Anthony; Wu, Xiaoli; Miller, Pamela; Stelzer, Sandra; Wen, Yefei; Kuang, Shihuan; Wrogemann, Klaus; Patel, Ketan; Ding, Hao; Schwamborn, Jens C

    2012-01-01

    Limb girdle muscular dystrophy type 2H (LGMD2H) is an inherited autosomal recessive disease of skeletal muscle caused by a mutation in the TRIM32 gene. Currently its pathogenesis is entirely unclear. Typically the regeneration process of adult skeletal muscle during growth or following injury is controlled by a tissue specific stem cell population termed satellite cells. Given that TRIM32 regulates the fate of mammalian neural progenitor cells through controlling their differentiation, we asked whether TRIM32 could also be essential for the regulation of myogenic stem cells. Here we demonstrate for the first time that TRIM32 is expressed in the skeletal muscle stem cell lineage of adult mice, and that in the absence of TRIM32, myogenic differentiation is disrupted. Moreover, we show that the ubiquitin ligase TRIM32 controls this process through the regulation of c-Myc, a similar mechanism to that previously observed in neural progenitors. Importantly we show that loss of TRIM32 function induces a LGMD2H-like phenotype and strongly affects muscle regeneration in vivo. Our studies implicate that the loss of TRIM32 results in dysfunctional muscle stem cells which could contribute to the development of LGMD2H. PMID:22299041

  17. 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

  18. Bone marrow-derived cell regulation of skeletal muscle regeneration.

    PubMed

    Sun, Dongxu; Martinez, Carlo O; Ochoa, Oscar; Ruiz-Willhite, Lourdes; Bonilla, Jose R; Centonze, Victoria E; Waite, Lindsay L; Michalek, Joel E; McManus, Linda M; Shireman, Paula K

    2009-02-01

    Limb regeneration requires the coordination of multiple stem cell populations to recapitulate the process of tissue formation. Therefore, bone marrow (BM) -derived cell regulation of skeletal muscle regeneration was examined in mice lacking the CC chemokine receptor 2 (CCR2). Myofiber size, numbers of myogenic progenitor cells (MPCs), and recruitment of BM-derived cells and macrophages were assessed after cardiotoxin-induced injury of chimeric mice produced by transplanting BM from wild-type (WT) or CCR2(-/-) mice into irradiated WT or CCR2(-/-) host mice. Regardless of the host genotype, muscle regeneration and recruitment of BM-derived cells and macrophages were similar in mice replenished with WT BM, whereas BM-derived cells and macrophage accumulation were decreased and muscle regeneration was impaired in all animals receiving CCR2(-/-) BM. Furthermore, numbers of MPCs (CD34(+)/Sca-1(-)/CD45(-) cells) were significantly increased in mice receiving CCR2(-/-) BM despite the decreased size of regenerated myofibers. Thus, the expression of CCR2 on BM-derived cells regulated macrophage recruitment into injured muscle, numbers of MPC, and the extent of regenerated myofiber size, all of which were independent of CCR2 expression on host-derived cells. Future studies in regenerative medicine must include consideration of the role of BM-derived cells, possibly macrophages, in CCR2-dependent events that regulate effective skeletal muscle regeneration. PMID:18827026

  19. 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

  20. Laminin regulates PDGFRβ(+) cell stemness and muscle development.

    PubMed

    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

  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. Estrogens maintain skeletal muscle and satellite cell functions.

    PubMed

    Kitajima, Yuriko; Ono, Yusuke

    2016-06-01

    Estrogens have crucial roles in an extensive range of physiological functions regulating cellular proliferation and differentiation, development, homeostasis, and metabolism. Therefore, prolonged estrogen insufficiency influences various types of tissues expressing estrogen receptors (ERs). Although ERs are expressed in skeletal muscle and its stem cells, called satellite cells, how prolonged estrogen insufficiency affects their function remains unclear. In this study, we investigated the effect of estrogen reduction on muscle in young ovariectomized (OVX) female mice. We found that reduced estrogens resulted in muscle atrophy in a time-dependent manner. Muscle force generation was reduced in OVX mice. Interestingly, prolonged estrogen insufficiency shifted fiber types toward faster myosin heavy chain isoforms. The number of satellite cells per isolated myofiber was unchanged, while satellite cell expansion, differentiation, and self-renewal were all markedly impaired in OVX mice. Indeed, muscle regeneration was significantly compromised in OVX mice. Taken together, our results demonstrate that estrogens are essential for comprehensively maintaining muscle function with its insufficiency affecting muscle strength and regeneration in young female mice. PMID:27048232

  3. 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.

  4. The 4977 bp deletion of mitochondrial DNA in human skeletal muscle, heart and different areas of the brain: a useful biomarker or more?

    PubMed

    Meissner, Christoph; Bruse, Petra; Mohamed, Salaheldien Ali; Schulz, Anja; Warnk, Hanne; Storm, Thilo; Oehmichen, Manfred

    2008-07-01

    It has been suggested that deletions of mitochondrial DNA (mtDNA) are important players with regard to the ageing process. Since the early 1990s, the 4977 bp deletion has been studied in various tissues, especially in postmitotic tissues with high energy demand. Unfortunately, some of these studies included less than 10 subjects, so the aim of our study was to quantify reliably the deletion amount in nine different regions of human brain, heart and skeletal muscle in a cohort of 92 individuals. The basal ganglia contain the highest deletion amounts with values up to 2.93% and differences in deletion levels between early adolescence and older ages were up to three orders of magnitude. Values in frontal lobe were on average an order of magnitude lower, but lowest in cerebellar tissue where the amount was on average only 5 x 10(-3) of the basal ganglia. The deletion started to accumulate in iliopsoas muscle early in the fourth decade of life with values between 0.00019% and 0.0035% and was highest in a 102-year-old woman with 0.14%. In comparison to skeletal muscle, the overall abundance in heart muscle of the left ventricle was only one-third. The best linear logarithmic correlation between amount of the deletion and age was found in substantia nigra with r=0.87 (p<0.0005) followed by anterior wall of the left ventricle (r=0.82; p<0.0005). With regard to mitochondrial DNA damage, we propose to use the 4977 bp deletion as an ideal biomarker to discriminate between physiological ageing and accelerated ageing. The biological meaning of mitochondrial deletions in the process of ageing is under discussion, but there is experimental evidence that large-scale deletions impair the oxidative phosphorylation in single cells and sensitize these cells to undergo apoptosis. PMID:18439778

  5. 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.

  6. Human Muscle Satellite Cells as Targets of Chikungunya Virus Infection

    PubMed Central

    Ozden, Simona; Huerre, Michel; Riviere, Jean-Pierre; Coffey, Lark L.; Afonso, Philippe V.; Mouly, Vincent; de Monredon, Jean; Roger, Jean-Christophe; El Amrani, Mohamed; Yvin, Jean-Luc; Jaffar, Marie-Christine; Frenkiel, Marie-Pascale; Sourisseau, Marion; Schwartz, Olivier; Butler-Browne, Gillian; Desprès, Philippe; Gessain, Antoine; Ceccaldi, Pierre-Emmanuel

    2007-01-01

    Background Chikungunya (CHIK) virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. Since 2005, the emergence of CHIK virus was associated with an unprecedented magnitude outbreak of CHIK disease in the Indian Ocean. Clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. Since the cellular targets of CHIK virus in humans are unknown, we studied the pathogenic events and targets of CHIK infection in skeletal muscle. Methodology/Principal Findings Immunohistology on muscle biopsies from two CHIK virus-infected patients with myositic syndrome showed that viral antigens were found exclusively inside skeletal muscle progenitor cells (designed as satelllite cells), and not in muscle fibers. To evaluate the ability of CHIK virus to replicate in human satellite cells, we assessed virus infection on primary human muscle cells; viral growth was observed in CHIK virus-infected satellite cells with a cytopathic effect, whereas myotubes were essentially refractory to infection. Conclusions/Significance This report provides new insights into CHIK virus pathogenesis, since it is the first to identify a cellular target of CHIK virus in humans and to report a selective infection of muscle satellite cells by a viral agent in humans. PMID:17565380

  7. Congenital Heart Defects Are Rarely Caused by Mutations in Cardiac and Smooth Muscle Actin Genes

    PubMed Central

    Khodyuchenko, Tatiana; Zlotina, Anna; Pervunina, Tatiana; Zverev, Dmitry; Malashicheva, Anna; Kostareva, Anna

    2015-01-01

    Background. Congenital heart defects (CHDs) often have genetic background due to missense mutations in cardiomyocyte-specific genes. For example, cardiac actin was shown to be involved in pathogenesis of cardiac septum defects and smooth muscle actin in pathogenesis of aortic aneurysm in combination with patent ductus arteriosus (PDA). In the present study, we further searched for mutations in human α-cardiac actin (ACTC1) and smooth muscle α-actin (ACTA2) genes as a possible cause of atrial septum defect type II (ASDII) and PDA. Findings. Total genomic DNA was extracted from peripheral blood of 86 individuals with ASDs and 100 individuals with PDA. Coding exons and flanking intron regions of ACTC1 (NM_005159.4) and ACTA2 (NM_001613) were amplified by PCR with specific primers designed according to the corresponding gene reference sequences. PCR fragments were directly sequenced and analyzed. Sequence analysis of ACTC1 and ACTA2 did not identify any nucleotide changes that altered the coding sense of the genes. In ACTC1 gene, we were able to detect one previously described nucleotide polymorphism (rs2307493) resulting in a synonymous substitution. The frequency of this SNP was similar in the study and control group, thus excluding it from the possible disease-associated variants. Conclusions. Our results confirmed that the mutations in ACTC1 gene are rare (at least <1%) cause of ASDII. Mutations in ACTA2 gene were not detected in patients with PDA, thus being excluded from the list of frequent PDA-associated genetic defects. PMID:25861618

  8. Electrophysiological effects of newly synthesized 1,4-pyridothiazepines on various guinea pig heart muscle preparations.

    PubMed

    Schade, B

    1999-01-01

    Slow channel blockers play a major role in the treatment of cardiovascular disease. The intention of this study was to investigate the electrophysiological properties of MM 4 (1-[N-[2-(3,4-dimethoxy-phenyl)ethyl]-N-methylaminoacetyl]-1,2,3,4 -tetrahydropyrido[2,3-b][1,4]thiazepine fumarate) and MM 6 (1-[N-[2-(3,4-dimethoxy-phenyl)ethyl]-N-methylaminopropionyl]-1,2, 3,4-tetrahydropyrido[2,3-b][1,4]thiazepine fumarate), two newly synthesized compounds structurally related to KT-362 (5-[3-[[2-(3,4-dimethoxy-phenyl)ethyl]-amino]-1-oxopropyl]-2,3,4,5-tetra -hydro-1,5-benzothiazepine fumarate), by means of the conventional intracellular microelectrode technique. In various guinea pig heart muscle preparations, MM 4 and MM 6 exerted very similar effects though the action of MM 6 was more pronounced. In a concentration range from 3 to 100 micromol/l the compounds did not produce any significant change in transmembrane action potential parameters of papillary muscle and left atria, whereas the action potential duration at 20% and 50% time to repolarization in spontaneously beating Purkinje fibers was significantly shortened. In sinoatrial nodes action potential amplitude, Vmax, rate of activity and slope of slow diastolic depolarization were decreased, whereas the time to 50% and 90% repolarization was significantly prolonged. A decrease in the slow calcium inward current may account for the observed effects. In contrast to KT-362, MM 4 and MM 6 do not seem to affect the fast sodium inward current. It was concluded that replacement of the 1,5-benzothiazepine nucleus by a 1,4-pyridothiazepine structure and/or methylation of the side chain may weaken or even eliminate sodium channel blocking ability while calcium antagonistic characteristics are preserved. Shortening of the side chain might result in a general loss of activity. PMID:9989658

  9. Hyperbaric oxygenation enhances transplanted cell graft and functional recovery in the infarct heart

    PubMed Central

    Khan, Mahmood; Meduru, Sarath; Mohan, Iyyapu K.; Kuppusamy, M. Lakshmi; Wisel, Sheik; Kulkarni, Aditi; Rivera, Brian K.; Hamlin, Robert L.; Kuppusamy, Periannan

    2009-01-01

    A major limitation to the application of stem-cell therapy to repair ischemic heart damage is the low survival of transplanted cells in the heart, possibly due to poor oxygenation. We hypothesized that hyperbaric oxygenation (HBO) can be used as an adjuvant treatment to augment stem-cell therapy. Therefore, the goal of this study was to evaluate the effect of HBO on the engraftment of rat bone-marrow-derived mesenchymal stem cells (MSCs) transplanted in infarct rat hearts. Myocardial infarction (MI) was induced in Fisher-344 rats by permanently ligating the left-anterior-descending coronary artery. MSCs, labeled with fluorescent superparamagnetic iron oxide (SPIO) particles, were transplanted in the infarct and peri-infarct regions of the MI hearts. HBO (100% oxygen at 2 ATA for 90 min) was administered daily for 2 weeks. Four MI groups were used: untreated (MI); HBO; MSC; MSC+HBO. Echocardiography, electro-vectorcardiography, and magnetic resonance imaging were used for functional evaluations. The engraftment of transplanted MSCs in the heart was confirmed by SPIO fluorescence and Prussian-blue staining. Immunohistochemical staining was used to identify key cellular and molecular markers including CD29, troponin-T, connexin-43, VEGF, α-smooth-muscle actin, and von-Willebrand factor in the tissue. Compared to MI and MSC groups, the MSC+HBO group showed a significantly increased recovery of cardiac function including left-ventricular (LV) ejection fraction, fraction-shortening, LV wall-thickness, and QRS vector. Further, HBO treatment significantly increased the engraftment of CD29-positive cells, expression of connexin-43, troponin-T and VEGF, and angiogenesis in the infarct tissue. Thus, HBO appears to be a potential and clinically-viable adjuvant treatment for myocardial stem-cell therapy. PMID:19376124

  10. Cell death, clearance and immunity in the skeletal muscle.

    PubMed

    Sciorati, C; Rigamonti, E; Manfredi, A A; Rovere-Querini, P

    2016-06-01

    The skeletal muscle is an immunologically unique tissue. Leukocytes, virtually absent in physiological conditions, are quickly recruited into the tissue upon injury and persist during regeneration. Apoptosis, necrosis and autophagy coexist in the injured/regenerating muscles, including those of patients with neuromuscular disorders, such as inflammatory myopathies, dystrophies, metabolic and mitochondrial myopathies and drug-induced myopathies. Macrophages are able to alter their function in response to microenvironment conditions and as a consequence coordinate changes within the tissue from the early injury throughout regeneration and eventual healing, and regulate the activation and the function of stem cells. Early after injury, classically activated macrophages ('M1') dominate the picture. Alternatively activated M2 macrophages predominate during resolution phases and regulate the termination of the inflammatory responses. The dynamic M1/M2 transition is increasingly felt to be the key to the homeostasis of the muscle. Recognition and clearance of debris originating from damaged myofibers and from dying stem/progenitor cells, stromal cells and leukocytes are fundamental actions of macrophages. Clearance of apoptotic cells and M1/M2 transition are causally connected and represent limiting steps for muscle healing. The accumulation of apoptotic cells, which reflects their defective clearance, has been demonstrated in various tissues to prompt autoimmunity against intracellular autoantigens. In the muscle, in the presence of type I interferon, apoptotic myoblasts indeed cause the production of autoantibodies, lymphocyte infiltration and continuous cycles of muscle injury and regeneration, mimicking human inflammatory myopathies. The clearance of apoptotic cells thus modulates the homeostatic response of the skeletal muscle to injury. Conversely, defects in the process may have deleterious local effects, guiding maladaptive tissue remodeling with collagen and fat

  11. Endothelial Cells Direct Mesenchymal Stem Cells Toward a Smooth Muscle Cell Fate

    PubMed Central

    Lin, Cho-Hao

    2014-01-01

    Under defined conditions, mesenchymal stem cells can differentiate into unique cell types, making them attractive candidates for cell-based disease therapies. Ischemic diseases would greatly benefit from treatments that include the formation of new blood vessels from mesenchymal stem cells. However, blood vessels are complex structures composed of endothelial cells and smooth muscle cells, and their assembly and function in a diseased environment is reliant upon joining with the pre-existing vasculature. Although endothelial cell/smooth muscle cell interactions are well known, how endothelial cells may influence mesenchymal stem cells and facilitate their differentiation has not been defined. Therefore, we sought to explore how endothelial cells might drive mesenchymal stem cells toward a smooth muscle fate. Our data show that cocultured endothelial cells induce smooth muscle cell differentiation in mesenchymal stem cells. Endothelial cells can promote a contractile phenotype, reduce proliferation, and enhance collagen synthesis and secretion. Our data show that Notch signaling is essential for endothelial cell-dependent differentiation, and this differentiation pathway is largely independent of growth factor signaling mechanisms. PMID:24914692

  12. 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.

  13. Arsenic induces sustained impairment of skeletal muscle and muscle progenitor cell ultrastructure and bioenergetics.

    PubMed

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

    2014-09-01

    Over 4 million individuals in the United States, 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 1mg/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. Compared to nonexposed controls, mice exposed to drinking water containing 100 μg/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 were no differences in the levels of inorganic arsenic or its monomethyl 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, compared to cells isolated from nonexposed 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

  14. 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

  15. Effects of novel synthesized pyridothiazines on various guinea pig heart muscle preparations.

    PubMed

    Schade, Bettina; Erker, Thomas; Weber, Manuela; Studenik, Christian

    2004-09-01

    Calcium channel blockers have become important tools in the treatment of cardiovascular disorders and other diseases. Hybridization of well established calcium antagonist subclasses was an attempt to optimize their pharmacological profile. The intension of this study was to investigate the electrophysiological properties of MM 10 and MM 11 two newly synthesized compounds structurally closely related to KT-362 (5-[3-[[2-(3,4-dimethoxyphenyl)ethyl]amino]-1-oxopropyl]-2,3,4,5-tetrahydro-1,5-benzothiazepine fumarate) in various isolated guinea pig heart muscle preparations by means of the conventional intracellular microelectrode tech-nique. MM 10 (2,3-dihydro-1-[N-[2-(3,4-dimethoxyphenyl)ethyl]-N-methylaminoacetyl]-1H-pyrido[2,3-b][1,4]thiazine fumarate) and MM 11 (2,3-dihydro-1-[N-[2-(3,4-dimethoxyphenyl)ethyl]-N-methylaminopropionyl]-1H-pyrido[2,3-b][1,4]thiazine fumarate) exerted very similar effects though the action of MM 11 was more pronounced. Whereas action potential amplitude and maximum upstroke velocity (V(max)) in papillary muscle, left atria and spontaneously beating Purkinje fibers was not affected by the compounds in a concentration range from 3 to 30 micromol/l, action potential duration at 90% time to repolarization was significantly prolonged in a concentration-dependent manner. Action potential duration at 20% time to repolarization was decreased in spontaneously beating Purkinje fibers and remained unchanged in papillary muscles and left atria. In sinoatrial nodes both compounds reduced rate of activity, action potential amplitude, maximum upstroke velocity and slope of slow diastolic depolarization while time to repolarization was prolonged. In 3 out of 6 experiments with spontaneously beating Purkinje fibers, MM 11 (30 micromol/l) led to the occurrence of early afterdepolarizations with a take off potential between -50 and -60 mV. All observed effects were completely reversible during washout with drug-free physiological salt solution. From these

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

    PubMed Central

    Northover, B. J.

    1984-01-01

    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. PMID:6329388

  17. 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. PMID:16412584

  18. 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

  19. 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. PMID:26721686

  20. Serotonin augments smooth muscle differentiation of bone marrow stromal cells.

    PubMed

    Hirota, Nobuaki; McCuaig, Sarah; O'Sullivan, Michael J; Martin, James G

    2014-05-01

    Bone marrow stromal cells (BMSCs) contain a subset of multipotent stem cells. Here, we demonstrate that serotonin, a biogenic amine released by platelets and mast cells, can induce the smooth muscle differentiation of BMSCs. Brown Norway rat BMSCs stimulated with serotonin had increased expression of the smooth muscle markers smooth muscle myosin heavy chain (MHC) and α actin (α-SMA) by qPCR and Western blot, indicating smooth muscle differentiation. This was accompanied by a concomitant down-regulation of the microRNA miR-25-5p, which was found to negatively regulate smooth muscle differentiation. Serotonin upregulated serum response factor (SRF) and myocardin, transcription factors known to induce contractile protein expression in smooth muscle cells, while it down-regulated Elk1 and Kruppel-like factor 4 (KLF4), known to induce proliferation. Serotonin increased SRF binding to promoter regions of the MHC and α-SMA genes, assessed by chromatin immunoprecipitation assay. Induction of smooth muscle differentiation by serotonin was blocked by the knock-down of SRF and myocardin. Transforming growth factor (TGF)-β1 was constitutively expressed by BMSCs and serotonin triggered its release. Inhibition of miR-25-5p augmented TGF-β1 expression, however the differentiation of BMSCs was not mediated by TGF-β1. These findings demonstrate that serotonin promotes a smooth muscle-like phenotype in BMSCs by altering the balance of SRF, myocardin, Elk1 and KLF4 and miR-25-5p is involved in modulating this balance. Therefore, serotonin potentially contributes to the pathogenesis of diseases characterized by tissue remodeling with increased smooth muscle mass. PMID:24595007

  1. 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

  2. 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

  3. 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

  4. Gene Expression Analyses during Spontaneous Reversal of Cardiomyopathy in Mice with Repressed Nuclear CUG-BP, Elav-Like Family (CELF) Activity in Heart Muscle

    PubMed Central

    Dasgupta, Twishasri; Coram, Ryan J.; Stillwagon, Samantha J.; Ladd, Andrea N.

    2015-01-01

    CUG-BP, Elav-like family (CELF) proteins regulate cell type- and developmental stage-specific alternative splicing in the heart. Repression of CELF-mediated splicing activity via expression of a nuclear dominant negative CELF protein in heart muscle was previously shown to induce dysregulation of alternative splicing, cardiac dysfunction, cardiac hypertrophy, and dilated cardiomyopathy in MHC-CELFΔ transgenic mice. A “mild” line of MHC-CELFΔ mice that expresses a lower level of the dominant negative protein exhibits cardiac dysfunction and myopathy at a young age, but spontaneously recovers normal cardiac function and heart size with age despite the persistence of splicing defects. To the best of our knowledge, this was the first example of a genetically induced cardiomyopathy that spontaneously recovers without intervention. In this study, we explored the basis for this recovery. We examined whether a transcriptional program regulated by serum response factor (SRF) that is dysregulated in juvenile MHC-CELFΔ mice is restored in the mild line with age, and evaluated global changes in gene expression by microarray analyses. We found that differences in gene expression between the mild line and wild type hearts are greatly reduced in older animals, including a partial recovery of SRF target gene expression. We did not find evidence of a new compensatory pathway being activated in the mild line with age, and propose that recovery may occur due to developmental stage-specific compatibility of CELF-dependent splice variants with the cellular environment of the cardiomyocyte. PMID:25894229

  5. 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

  6. 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. PMID:26779264

  7. The deacetylase enzyme SIRT1 is not associated with oxidative capacity in rat heart and skeletal muscle and its overexpression reduces mitochondrial biogenesis

    PubMed Central

    Gurd, Brendon J; Yoshida, Yuko; Lally, James; Holloway, Graham P; Bonen, Arend

    2009-01-01

    Deacetylation of PGC-1α by SIRT1 is thought to be an important step in increasing PGC-1α transcriptional activity, since in muscle cell lines SIRT1 induces PGC-1α protein expression and mitochondrial biogenesis. We examined the relationship between SIRT1 protein and activity, PGC-1α and markers of mitochondrial density, (a) across a range of metabolically heterogeneous skeletal muscles and the heart, and when mitochondrial biogenesis was stimulated by (b) chronic muscle stimulation (7 days) and (c) AICAR administration (5 days), and finally, (d) we also examined the effects of SIRT1 overexpression on mitochondrial biogenesis and PGC-1α. SIRT1 protein and activity were correlated (r= 0.97). There were negative correlations between SIRT1 protein and PGC-1α (r=−0.95), COX IV (r=−0.94) and citrate synthase (r=−0.97). Chronic muscle stimulation and AICAR upregulated PGC-1α protein (22–159%) and oxidative capacity (COX IV, 20–69%); in each instance SIRT1 protein was downregulated by 20–40%, while SIRT1 intrinsic activity was increased. SIRT1 overexpression in rodent muscle increased SIRT1 protein (+240%) and doubled SIRT1 activity, but PGC-1α (−25%), mtTFA (−14%) and COX IV (−10%) proteins were downregulated. Taken altogether these experiments are not consistent with the notion that SIRT1 protein plays an obligatory regulatory role in the process of PGC-1α-mediated mitochondrial biogenesis in mammalian muscle. PMID:19237425

  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. Stripping of proteins from submitochondrial particles of rat skeletal muscle or bovine heart by chemical uncouplers.

    PubMed

    Yamada, E W; Huzel, N J

    1983-09-01

    Proteins of similar molecular weights were stripped from submitochondrial particles (A particles) of rat skeletal muscle or bovine heart by treatment with classical chemical uncouplers at 0 degrees C as with Ca2+. Proteins released included two of high molecular weight (about 43 000 and 30 000), an ATPase inhibitor protein (IF1) as well as the Ca2+-binding lipoprotein that has previously been shown to protect the mitochondrial ATPase complex against inhibition by N,N'-dicyclohexylcarbodiimide (DCCD). The latter two proteins were purified to a high degree. The crude fraction obtained by stripping with chemical uncouplers also contained traces of an additional protein (relative mass (Mr) approximately 13 000) which was also found upon aging of the crude fraction stripped by Ca2+. It was not found in aged preparations of either purified IF1 or the lipoprotein, but appeared when IF1 and the lipoprotein were mixed and aged together. Pretreatment of the mixture with 2-mercaptoethanol prior to electrophoresis did not remove the hybrid. More phospholipid was stripped from A particles by chemical uncouplers than by Ca2+ but less protein was stripped. Phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, and cardiolipin were identified in the phospholipid fractions. PMID:6226347

  10. 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

  11. A novel transgenic marker for migrating limb muscle precursors and for vascular smooth muscle cells.

    PubMed

    Tidhar, A; Reichenstein, M; Cohen, D; Faerman, A; Copeland, N G; Gilbert, D J; Jenkins, N A; Shani, M

    2001-01-01

    A unique pattern of LacZ expression was found in a transgenic mouse line, likely due to regulatory elements at the site of integration. Two new genes flanking the transgene were identified. At early stages of development, the transgene is transiently expressed in ventro-lateral demomyotomal cells migrating from the somites into the limb buds. At late developmental stages and in the adult, lacZ staining marks vascular smooth muscle cells throughout the vascular bed, with the exception of the major elastic arteries, and in pericytes. No expression was detected in skeletal and smooth muscles. Different patterns of expression in vascular smooth muscles was observed at distinct levels of the vascular tree, in arteries as well as in veins. Vessel injury, resulting in stimulation of smooth muscle cells proliferation and migration, is associated with transgene down-regulation. After the formation of neointima thickening, it is reactivated. This transgenic insertion may therefore be used as a useful marker to identify novel physiological cues or genetic elements involved in the regulation of the vascular smooth muscle phenotype(s). It may also provide an experimental tool for studying vasculature and the involvement of pericytes in regulating microvascular homeostasis. PMID:11146508

  12. Effects of methyl isocyanate on rat muscle cells in culture.

    PubMed

    Anderson, D; Goyle, S; Phillips, B J; Tee, A; Beech, L; Butler, W H

    1988-04-01

    Since the Bhopal disaster, in which the causal agent was methyl isocyanate (MIC), exposed people have complained of various disorders including neuromuscular dysfunction. In an attempt to gain some information about the response of muscle tissue to MIC its effects were investigated in cells in culture isolated from muscle of 2 day old rats. After treatment with a range of MIC concentrations (0.025-0.5 microliter/5 ml culture) the total number of nuclei of the two main cell types (fibroblasts and myoblasts) and the number of nuclei in muscle fibres (myotubes) were recorded. At lower doses which had little effect on the total number of nuclei, the formation of muscle fibres--that is, fusion of muscle cells--was prevented as the proportion of nuclei in myotubes was decreased. At higher doses both cell types were killed. This would suggest either an effect on muscle differentiation or a selective toxicity towards myoblasts. The observations were supported by light and electron microscopy. PMID:3378004

  13. 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. PMID:26589115

  14. 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

  15. Functional Overloading of Dystrophic Mice Enhances Muscle-Derived Stem Cell Contribution to Muscle Contractile Capacity

    PubMed Central

    Ambrosio, Fabrisia; Ferrari, Ricardo J.; Fitzgerald, G. Kelley; Carvell, George; Boninger, Michael L.; Huard, Johnny

    2016-01-01

    Objectives To evaluate the effect of functional overloading on the transplantation of muscle derived stem cells (MDSCs) into dystrophic muscle and the ability of transplanted cells to increase dystrophic muscle’s ability to resist overloading-induced weakness. Design Cross-sectional. Setting Laboratory. Animals Male mice (N=10) with a dystrophin gene mutation. Interventions MDSCs were intramuscularly transplanted into the extensor digitorum longus muscle (EDL). Functional overloading of the EDL was performed by surgical ablation of the EDL’s synergist. Main Outcome Measures The total number of dystrophin-positive fibers/cross-section (as a measure of stem cell engraftment), the average number of CD31+ cells (as a measure of capillarity), and in vitro EDL contractile strength. Independent t tests were used to investigate the effect of overloading on engraftment, capillarity, and strength. Paired t tests were used to investigate the effect of MDSC engraftment on strength and capillarity. Results MDSC transplantation protects dystrophic muscles against overloading-induced weakness (specific twitch force: control 4.5N/cm2±2.3; MDSC treated 7.9N/cm2±1.4) (P=.02). This improved force production following overloading is concomitant with an increased regeneration by transplanted MDSCs (MDSC: 26.6±20.2 dystrophin-positive fibers/cross-section; overloading + MDSC: 170.6±130.9 dystrophin-positive fibers/cross-section [P=.03]). Overloading-induced increases in skeletal muscle capillarity is significantly correlated with increased MDSC engraftment (R2=.80, P=.01). Conclusions These findings suggest that the functional contribution of transplanted MDSCs may rely on activity-dependent mechanisms, possibly mediated by skeletal muscle vascularity. Rehabilitation modalities may play an important role in the development of stem cell transplantation strategies for the treatment of muscular dystrophy. PMID:19154831

  16. 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.

  17. 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

  18. 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

  19. Role of mitochondria on muscle cell death and meat tenderization.

    PubMed

    Sierra, Verónica; Oliván, Mamen

    2013-05-01

    The possibility that mitochondria are involved in cellular dysfunction is particularly high in situations associated with increases in free radical activity, like hypoxia or ischemia; therefore its potential role in the muscle post-mortem metabolism is reviewed. In the dying muscle, different routes of cell death catabolism (apoptosis, autophagy) may occur having great influence on the process of conversion of muscle into meat. Mitochondria are the first and also one of the main organelles affected by post-mortem changes; therefore they are decisive in the subsequent cellular responses influencing the pathway to cell demise and thus, the final meat quality. Depending on the cell death programme followed by muscle cells after exsanguination, diverse proteases would be activated to a different extent, which is also reviewed in order to understand how they affect meat tenderization. This review also summarizes recent patents relating cell death processes and meat tenderness. Further research is encouraged as there is still a need of knowledge on cell death post-mortem processes to increase our understanding of the conversion of muscle into meat. PMID:23432120

  20. 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

  1. Kinetics of a single cross-bridge in familial hypertrophic cardiomyopathy heart muscle measured by reverse Kretschmann fluorescence

    NASA Astrophysics Data System (ADS)

    Mettikolla, Prasad; Calander, Nils; Luchowski, Rafal; Gryczynski, Ignacy; Gryczynski, Zygmunt; Borejdo, Julian

    2010-01-01

    Familial hypertrophic cardiomyopathy (FHC) is a serious heart disease that often leads to a sudden cardiac death of young athletes. It is believed that the alteration of the kinetics of interaction between actin and myosin causes FHC by making the heart to pump blood inefficiently. We set out to check this hypothesis ex vivo. During contraction of heart muscle, a myosin cross-bridge imparts periodic force impulses to actin. The impulses are analyzed by fluorescence correlation spectroscopy (FCS) of fluorescently labeled actin. To minimize observation volume and background fluorescence, we carry out FCS measurements in surface plasmon coupled emission mode in a reverse Kretschmann configuration. Fluorescence is a result of near-field coupling of fluorophores excited in the vicinity of the metal-coated surface of a coverslip with the surface plasmons propagating in the metal. Surface plasmons decouple on opposite sides of the metal film and emit in a directional manner as far-field p-polarized radiation. We show that the rate of changes of orientation is significantly faster in contracting cardiac myofibrils of transgenic mice than wild type. These results are consistent with the fact that mutated heart muscle myosin translates actin faster in in vitro motility assays.

  2. Diet-induced Lethality Due to Deletion of the Hdac3 Gene in Heart and Skeletal Muscle*♦

    PubMed Central

    Sun, Zheng; Singh, Nikhil; Mullican, Shannon E.; Everett, Logan J.; Li, Li; Yuan, Lijun; Liu, Xi; Epstein, Jonathan A.; Lazar, Mitchell A.

    2011-01-01

    Many human diseases result from the influence of the nutritional environment on gene expression. The environment interacts with the genome by altering the epigenome, including covalent modification of nucleosomal histones. Here, we report a novel and dramatic influence of diet on the phenotype and survival of mice in which histone deacetylase 3 (Hdac3) is deleted postnatally in heart and skeletal muscle. Although embryonic deletion of myocardial Hdac3 causes major cardiomyopathy that reduces survival, we found that excision of Hdac3 in heart and muscle later in development leads to a much milder phenotype and does not reduce survival when mice are fed normal chow. Remarkably, upon switching to a high fat diet, the mice begin to die within weeks and display signs of severe hypertrophic cardiomyopathy and heart failure. Down-regulation of myocardial mitochondrial bioenergetic genes, specifically those involved in lipid metabolism, precedes the full development of cardiomyopathy, suggesting that HDAC3 is important in maintaining proper mitochondrial function. These data suggest that loss of the epigenomic modifier HDAC3 causes dietary lethality by compromising the ability of cardiac mitochondria to respond to changes of nutritional environment. In addition, this study provides a mouse model for diet-inducible heart failure. PMID:21808063

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. Trichinella spiralis: nurse cell formation with emphasis on analogy to muscle cell repair

    PubMed Central

    Wu, Zhiliang; Sofronic-Milosavljevic, Lj; Nagano, Isao; Takahashi, Yuzo

    2008-01-01

    Trichinella infection results in formation of a capsule in infected muscles. The capsule is a residence of the parasite which is composed of the nurse cell and fibrous wall. The process of nurse cell formation is complex and includes infected muscle cell response (de-differentiation, cell cycle re-entry and arrest) and satellite cell responses (activation, proliferation and differentiation). Some events that occur during the nurse cell formation are analogous to those occurring during muscle cell regeneration/repair. This article reviews capsule formation with emphasis on this analogy. PMID:18710582

  10. 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