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Sample records for airway smooth muscles

  1. Genetic differences in airway smooth muscle function.

    PubMed

    Martin, James G; Jo, Taisuke

    2008-01-01

    The genetic basis for airway smooth muscle properties is poorly explored. Contraction and relaxation are altered in asthmatic airway smooth muscle, but the basis for the alterations and the role that muscle-specific susceptibility genes may play is largely unexplored. Alterations in the beta-adrenergic receptor, signaling pathways affecting inositol phosphate metabolism, adenylyl and guanylyl cyclase activity, and contractile proteins such as the myosin heavy chain are all suggested by experimental model systems. Significant changes in proliferative and secretory capacities of asthmatic smooth muscle are also demonstrated, but their genetic basis also requires elucidation. Certain asthma-related genes such as ADAM33, although potentially important for smooth muscle function, have been incompletely explored. PMID:18094088

  2. Origins of increased airway smooth muscle mass in asthma.

    PubMed

    Berair, Rachid; Saunders, Ruth; Brightling, Christopher E

    2013-01-01

    Asthma is characterized by both chronic inflammation and airway remodeling. Remodeling--the structural changes seen in asthmatic airways--is pivotal in the pathogenesis of the disease. Although significant advances have been made recently in understanding the different aspects of airway remodeling, the exact biology governing these changes remains poorly understood. There is broad agreement that, in asthma, increased airway smooth muscle mass, in part due to smooth muscle hyperplasia, is a very significant component of airway remodeling. However, significant debate persists on the origins of these airway smooth muscle cells. In this review article we will explore the natural history of airway remodeling in asthma and we will discuss the possible contribution of progenitors, stem cells and epithelial cells in mesenchymal cell changes, namely airway smooth muscle hyperplasia seen in the asthmatic airways. PMID:23742314

  3. Cortex phellodendri Extract Relaxes Airway Smooth Muscle

    PubMed Central

    Jiang, Qiu-Ju; Chen, Weiwei; Dan, Hong; Tan, Li; Zhu, He; Yang, Guangzhong; Shen, Jinhua; Peng, Yong-Bo; Zhao, Ping; Xue, Lu; Yu, Meng-Fei; Ma, Liqun; Si, Xiao-Tang; Wang, Zhuo; Dai, Jiapei; Qin, Gangjian; Zou, Chunbin; Liu, Qing-Hua

    2016-01-01

    Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K+- and acetylcholine- (ACH-) induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K+ was also blocked by nifedipine, a selective blocker of L-type Ca2+ channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca2+ channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm. PMID:27239213

  4. Airway smooth muscle in the pathophysiology and treatment of asthma

    PubMed Central

    Solway, Julian

    2013-01-01

    Airway smooth muscle (ASM) plays an integral part in the pathophysiology of asthma. It is responsible for acute bronchoconstriction, which is potentiated by constrictor hyperresponsiveness, impaired relaxation and length adaptation. ASM also contributes to airway remodeling and inflammation in asthma. In light of this, ASM is an important target in the treatment of asthma. PMID:23305987

  5. Bronchospasm and its biophysical basis in airway smooth muscle

    PubMed Central

    Fredberg, Jeffrey J

    2004-01-01

    Airways hyperresponsiveness is a cardinal feature of asthma but remains unexplained. In asthma, the airway smooth muscle cell is the key end-effector of bronchospasm and acute airway narrowing, but in just the past five years our understanding of the relationship of responsiveness to muscle biophysics has dramatically changed. It has become well established, for example, that muscle length is equilibrated dynamically rather than statically, and that non-classical features of muscle biophysics come to the forefront, including unanticipated interactions between the muscle and its time-varying load, as well as the ability of the muscle cell to adapt rapidly to changes in its dynamic microenvironment. These newly discovered phenomena have been described empirically, but a mechanistic basis to explain them is only beginning to emerge. PMID:15084229

  6. Emergence of airway smooth muscle functions related to structural malleability

    PubMed Central

    Fredberg, Jeffrey J.

    2011-01-01

    The function of a complex system such as a smooth muscle cell is the result of the active interaction among molecules and molecular aggregates. Emergent macroscopic manifestations of these molecular interactions, such as the length-force relationship and its associated length adaptation, are well documented, but the molecular constituents and organization that give rise to these emergent muscle behaviors remain largely unknown. In this minireview, we describe emergent properties of airway smooth muscle that seem to have originated from inherent fragility of the cellular structures, which has been increasingly recognized as a unique and important smooth muscle attribute. We also describe molecular interactions (based on direct and indirect evidence) that may confer malleability on fragile structural elements that in turn may allow the muscle to adapt to large and frequent changes in cell dimensions. Understanding how smooth muscle works may hinge on how well we can relate molecular events to its emergent macroscopic functions. PMID:21127211

  7. Epithelial modulation of preterm airway smooth muscle contraction.

    PubMed

    Panitch, H B; Wolfson, M R; Shaffer, T H

    1993-03-01

    To determine if epithelium from immature airways can modulate the responsiveness of smooth muscle, we studied paired trachealis muscle strips from preterm sheep. The epithelium was removed from one strip and left undisturbed in the other. Concentration-effect (CE) curves to acetylcholine (ACh), KCl, and isoproterenol were obtained. To evaluate maturational effects, responses to ACh and isoproterenol were studied in trachealis strips from adult airways. Maximal stress (Po) to ACh increased after epithelium removal in preterm (P < 0.05) but not adult strips. Epithelium removal caused a leftward shift of the ACh CE curves in both preterm and adult strips (P < 0.001) and a decrease in the dose required to achieve a one-half maximal response (ED50) in both preterm (P < 0.005) and adult strips (P < 0.05). The magnitude of the change in Po as well as in the ED50 for ACh between preterms and adults was similar. Epithelium removal did not alter either the Po or the CE curves of preterm strips stimulated by KCl. Response to isoproterenol in precontracted strips was enhanced in the presence of an intact epithelium in both groups (P < 0.05). These data demonstrate that preterm airway epithelium is able to modulate the responsiveness of smooth muscle. Additionally, the magnitude of the effect is unchanged with maturation. We speculate that damage of airway epithelium from mechanical ventilation may contribute to the increased incidence of airway hyperreactivity observed in preterm infants. PMID:8482688

  8. Airway hyperresponsiveness; smooth muscle as the principal actor

    PubMed Central

    Lauzon, Anne-Marie; Martin, James G.

    2016-01-01

    Airway hyperresponsiveness (AHR) is a defining characteristic of asthma that refers to the capacity of the airways to undergo exaggerated narrowing in response to stimuli that do not result in comparable degrees of airway narrowing in healthy subjects. Airway smooth muscle (ASM) contraction mediates airway narrowing, but it remains uncertain as to whether the smooth muscle is intrinsically altered in asthmatic subjects or is responding abnormally as a result of the milieu in which it sits. ASM in the trachea or major bronchi does not differ in its contractile characteristics in asthmatics, but the more pertinent peripheral airways await complete exploration. The mass of ASM is increased in many but not all asthmatics and therefore cannot be a unifying hypothesis for AHR, although when increased in mass it may contribute to AHR. The inability of a deep breath to reverse or prevent bronchial narrowing in asthma may reflect an intrinsic difference in the mechanisms that lead to softening of contracted ASM when subjected to stretch. Cytokines such as interleukin-13 and tumor necrosis factor-α promote a more contractile ASM phenotype. The composition and increased stiffness of the matrix in which ASM is embedded promotes a more proliferative and pro-inflammatory ASM phenotype, but the expected dedifferentiation and loss of contractility have not been shown. Airway epithelium may drive ASM proliferation and/or molecular remodeling in ways that may lead to AHR. In conclusion, AHR is likely multifactorial in origin, reflecting the plasticity of ASM properties in the inflammatory environment of the asthmatic airway. PMID:26998246

  9. Airway hyperresponsiveness; smooth muscle as the principal actor.

    PubMed

    Lauzon, Anne-Marie; Martin, James G

    2016-01-01

    Airway hyperresponsiveness (AHR) is a defining characteristic of asthma that refers to the capacity of the airways to undergo exaggerated narrowing in response to stimuli that do not result in comparable degrees of airway narrowing in healthy subjects. Airway smooth muscle (ASM) contraction mediates airway narrowing, but it remains uncertain as to whether the smooth muscle is intrinsically altered in asthmatic subjects or is responding abnormally as a result of the milieu in which it sits. ASM in the trachea or major bronchi does not differ in its contractile characteristics in asthmatics, but the more pertinent peripheral airways await complete exploration. The mass of ASM is increased in many but not all asthmatics and therefore cannot be a unifying hypothesis for AHR, although when increased in mass it may contribute to AHR. The inability of a deep breath to reverse or prevent bronchial narrowing in asthma may reflect an intrinsic difference in the mechanisms that lead to softening of contracted ASM when subjected to stretch. Cytokines such as interleukin-13 and tumor necrosis factor-α promote a more contractile ASM phenotype. The composition and increased stiffness of the matrix in which ASM is embedded promotes a more proliferative and pro-inflammatory ASM phenotype, but the expected dedifferentiation and loss of contractility have not been shown. Airway epithelium may drive ASM proliferation and/or molecular remodeling in ways that may lead to AHR. In conclusion, AHR is likely multifactorial in origin, reflecting the plasticity of ASM properties in the inflammatory environment of the asthmatic airway. PMID:26998246

  10. Angiogenesis is induced by airway smooth muscle strain.

    PubMed

    Hasaneen, Nadia A; Zucker, Stanley; Lin, Richard Z; Vaday, Gayle G; Panettieri, Reynold A; Foda, Hussein D

    2007-10-01

    Angiogenesis is an important feature of airway remodeling in both chronic asthma and chronic obstructive pulmonary disease (COPD). Airways in those conditions are exposed to excessive mechanical strain during periods of acute exacerbations. We recently reported that mechanical strain of human airway smooth muscle (HASM) led to an increase in their proliferation and migration. Sustained growth in airway smooth muscle in vivo requires an increase in the nutritional supply to these muscles, hence angiogenesis. In this study, we examined the hypothesis that cyclic mechanical strain of HASM produces factors promoting angiogenic events in the surrounding vascular endothelial cells. Our results show: 1) a significant increase in human lung microvascular endothelial cell (HMVEC-L) proliferation, migration, and tube formation following incubation in conditioned media (CM) from HASM cells exposed to mechanical strain; 2) mechanical strain of HASM cells induced VEGF expression and release; 3) VEGF neutralizing antibodies inhibited the proliferation, migration, and tube formations of HMVEC-L induced by the strained airway smooth muscle CM; 4) mechanical strain of HASM induced a significant increase in hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA and protein, a transcription factor required for VEGF gene transcription; and 5) mechanical strain of HASM induced HIF-1alpha/VEGF through dual phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and ERK pathways. In conclusion, exposing HASM cells to mechanical strain induces signal transduction pathway through PI3K/Akt/mTOR and ERK pathways that lead to an increase in HIF-1alpha, a transcription factor required for VEGF expression. VEGF release by mechanical strain of HASM may contribute to the angiogenesis seen with repeated exacerbation of asthma and COPD. PMID:17693481

  11. MicroRNA regulation of airway smooth muscle function.

    PubMed

    Sun, Maoyun; Lu, Quan

    2016-06-01

    Airway smooth muscle (ASM) controls airway narrowing and plays a pivotal role in the pathogenesis of asthma. MicroRNAs are small yet powerful gene tuners that regulate diverse cellular processes. Recent studies have demonstrated the versatile role of microRNAs in regulating multiple ASM phenotypes that are critically involved in asthma pathogenesis. These ASM phenotypes include proliferation, cell size, chemokine secretion, and contractility. Here we review microRNA-mediated regulation of ASM functions and discuss the potential of microRNAs as a novel class of therapeutic targets to improve ASM function for asthma therapy. PMID:26812790

  12. The Pivotal Role of Airway Smooth Muscle in Asthma Pathophysiology

    PubMed Central

    Ozier, Annaïg; Allard, Benoit; Bara, Imane; Girodet, Pierre-Olivier; Trian, Thomas; Marthan, Roger; Berger, Patrick

    2011-01-01

    Asthma is characterized by the association of airway hyperresponsiveness (AHR), inflammation, and remodelling. The aim of the present article is to review the pivotal role of airway smooth muscle (ASM) in the pathophysiology of asthma. ASM is the main effector of AHR. The mechanisms of AHR in asthma may involve a larger release of contractile mediators and/or a lower release of relaxant mediators, an improved ASM cell excitation/contraction coupling, and/or an alteration in the contraction/load coupling. Beyond its contractile function, ASM is also involved in bronchial inflammation and remodelling. Whereas ASM is a target of the inflammatory process, it can also display proinflammatory and immunomodulatory functions, through its synthetic properties and the expression of a wide range of cell surface molecules. ASM remodelling represents a key feature of asthmatic bronchial remodelling. ASM also plays a role in promoting complementary airway structural alterations, in particular by its synthetic function. PMID:22220184

  13. Airway smooth muscle dynamics: a common pathway of airway obstruction in asthma

    PubMed Central

    An, S.S.; Bai, T.R.; Bates, J.H.T.; Black, J.L.; Brown, R.H.; Brusasco, V.; Chitano, P.; Deng, L.; Dowell, M.; Eidelman, D.H.; Fabry, B.; Fairbank, N.J.; Ford, L.E.; Fredberg, J.J.; Gerthoffer, W.T.; Gilbert, S.H.; Gosens, R.; Gunst, S.J.; Halayko, A.J.; Ingram, R.H.; Irvin, C.G.; James, A.L.; Janssen, L.J.; King, G.G.; Knight, D.A.; Lauzon, A.M.; Lakser, O.J.; Ludwig, M.S.; Lutchen, K.R.; Maksym, G.N.; Martin, J.G.; Mauad, T.; McParland, B.E.; Mijailovich, S.M.; Mitchell, H.W.; Mitchell, R.W.; Mitzner, W.; Murphy, T.M.; Paré, P.D.; Pellegrino, R.; Sanderson, M.J.; Schellenberg, R.R.; Seow, C.Y.; Silveira, P.S.P.; Smith, P.G.; Solway, J.; Stephens, N.L.; Sterk, P.J.; Stewart, A.G.; Tang, D.D.; Tepper, R.S.; Tran, T.; Wang, L.

    2008-01-01

    Excessive airway obstruction is the cause of symptoms and abnormal lung function in asthma. As airway smooth muscle (ASM) is the effecter controlling airway calibre, it is suspected that dysfunction of ASM contributes to the pathophysiology of asthma. However, the precise role of ASM in the series of events leading to asthmatic symptoms is not clear. It is not certain whether, in asthma, there is a change in the intrinsic properties of ASM, a change in the structure and mechanical properties of the noncontractile components of the airway wall, or a change in the interdependence of the airway wall with the surrounding lung parenchyma. All these potential changes could result from acute or chronic airway inflammation and associated tissue repair and remodelling. Anti-inflammatory therapy, however, does not “cure” asthma, and airway hyperresponsiveness can persist in asthmatics, even in the absence of airway inflammation. This is perhaps because the therapy does not directly address a fundamental abnormality of asthma, that of exaggerated airway narrowing due to excessive shortening of ASM. In the present study, a central role for airway smooth muscle in the pathogenesis of airway hyperresponsiveness in asthma is explored. PMID:17470619

  14. Airway smooth muscle growth from the perspective of animal models.

    PubMed

    Martin, James G; Ramos-Barbón, David

    2003-09-16

    Airway smooth muscle maintains airway tone and may assist in adjusting ventilation distribution within the normal lung. Alterations in the properties or the quantity of ASM are likely responsible for some instances of airways hyperresponsiveness to bronchoconstrictive stimuli that is a characteristic of diseases such as asthma. Morphometric studies have shown an increase in the mass of ASM in human asthmatic airways. Animal models have been developed that confirm that ASM can be induced to grow by allergic sensitization and challenge. Growth is in large part by hyperplasia as measured by incorporation of bromodeoxyuridine as a marker of the S-phase of the cell cycle. T cells, in particular CD4+ cells, may participate in the stimulation of growth of ASM by allergen challenge. The growth factors responsible for the increase in ASM are as yet unidentified but two mediators associated with allergic airway responses, cysteinyl leukotrienes and endothelin, have been implicated using specific receptor antagonists. The links between T cells and the biochemical mediators of growth have not been established. PMID:14516730

  15. Airway smooth muscle responsiveness from dogs with airway hyperresponsiveness after O/sub 3/ inhalation

    SciTech Connect

    Jones, G.L.; O'Byrne, P.M.; Pashley, M.; Serio, R.; Jury, J.; Lane, C.G.; Daniel, E.E.

    1988-07-01

    Airway hyperresponsiveness occurs after inhalation of O3 in dogs. The purpose of this study was to examine the responsiveness of trachealis smooth muscle in vitro to electrical field stimulation, exogenous acetylcholine, and potassium chloride from dogs with airway hyperresponsiveness after inhaled O3 in vivo and to compare this with the responsiveness of trachealis muscle from control dogs. In addition, excitatory junction potentials were measured with the use of single and double sucrose gap techniques in both groups of dogs to determine whether inhaled O3 affects the release of acetylcholine from parasympathetic nerves in trachealis muscle. Airway hyperresponsiveness developed in all dogs after inhaled O3 (3 ppm for 30 min). The acetylcholine provocative concentration decreased from 4.11 mg/ml before O3 inhalation to 0.66 mg/ml after O3 (P less than 0.0001). The acetylcholine provocative concentration increased slightly after control inhalation of dry room air. Airway smooth muscle showed increased responses to both electrical field stimulation and exogenous acetylcholine but not to potassium chloride in preparations from dogs with airway hyperresponsiveness in vivo. The increased response to electrical field stimulation was not associated with a change in excitatory junctional potentials. These results suggest that a postjunctional alteration in trachealis muscle function occurs after inhaled O3 in dogs, which may account for airway hyperresponsiveness after O3 in vivo.

  16. Mechanisms of BDNF regulation in asthmatic airway smooth muscle.

    PubMed

    Aravamudan, Bharathi; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S

    2016-08-01

    Brain-derived neurotrophic factor (BDNF), a neurotrophin produced by airway smooth muscle (ASM), enhances inflammation effects on airway contractility, supporting the idea that locally produced growth factors influence airway diseases such as asthma. We endeavored to dissect intrinsic mechanisms regulating endogenous, as well as inflammation (TNF-α)-induced BDNF secretion in ASM of nonasthmatic vs. asthmatic humans. We focused on specific Ca(2+) regulation- and inflammation-related signaling cascades and quantified BDNF secretion. We find that TNF-α enhances BDNF release by ASM cells, via several mechanisms relevant to asthma, including transient receptor potential channels TRPC3 and TRPC6 (but not TRPC1), ERK 1/2, PI3K, PLC, and PKC cascades, Rho kinase, and transcription factors cAMP response element binding protein and nuclear factor of activated T cells. Basal BDNF expression and secretion are elevated in asthmatic ASM and increase further with TNF-α exposure, involving many of these regulatory mechanisms. We conclude that airway BDNF secretion is regulated at multiple levels, providing a basis for autocrine effects of BDNF under conditions of inflammation and disease, with potential downstream influences on contractility and remodeling. PMID:27317689

  17. Critical role of actin-associated proteins in smooth muscle contraction, cell proliferation, airway hyperresponsiveness and airway remodeling.

    PubMed

    Tang, Dale D

    2015-01-01

    Asthma is characterized by airway hyperresponsiveness and airway remodeling, which are largely attributed to increased airway smooth muscle contractility and cell proliferation. It is known that both chemical and mechanical stimulation regulates smooth muscle contraction. Recent studies suggest that contractile activation and mechanical stretch induce actin cytoskeletal remodeling in smooth muscle. However, the mechanisms that control actin cytoskeletal reorganization are not completely elucidated. This review summarizes our current understanding regarding how actin-associated proteins may regulate remodeling of the actin cytoskeleton in airway smooth muscle. In particular, there is accumulating evidence to suggest that Abelson tyrosine kinase (Abl) plays a critical role in regulating airway smooth muscle contraction and cell proliferation in vitro, and airway hyperresponsiveness and remodeling in vivo. These studies indicate that Abl may be a novel target for the development of new therapy to treat asthma. PMID:26517982

  18. Airway smooth muscle and bronchospasm: fluctuating, fluidizing, freezing

    PubMed Central

    Krishnan, Ramaswamy; Trepat, Xavier; Nguyen, Trang T. B.; Lenormand, Guillaume; Oliver, Madavi; Fredberg, Jeffrey J.

    2008-01-01

    We review here four recent findings that have altered in a fundamental way our understanding of airways smooth muscle (ASM), its dynamic responses to physiological loading, and their dominant mechanical role in bronchospasm. These findings highlight ASM remodeling processes that are innately out-of-equilibrium and dynamic, and bring to the forefront a striking intersection between topics in condensed matter physics and ASM cytoskeletal biology. By doing so, they place in a new light the role of enhanced ASM mass in airway hyper-responsiveness as well as in the failure of a deep inspiration to relax the asthmatic airway. These findings have established that (i) ASM length is equilibrated dynamically, not statically; (ii) ASM dynamics closely resemble physical features exhibited by so-called soft glassy materials; (iii) static force-length relationships fail to describe dynamically contracted ASM states; (iv) stretch fluidizes the ASM cytoskeleton. Taken together, these observations suggest that at the origin of the bronchodilatory effect of a deep inspiration, and its failure in asthma, may lie glassy dynamics of the ASM cell. PMID:18514592

  19. Airway smooth muscle in airway reactivity and remodeling: what have we learned?

    PubMed Central

    2013-01-01

    It is now established that airway smooth muscle (ASM) has roles in determining airway structure and function, well beyond that as the major contractile element. Indeed, changes in ASM function are central to the manifestation of allergic, inflammatory, and fibrotic airway diseases in both children and adults, as well as to airway responses to local and environmental exposures. Emerging evidence points to novel signaling mechanisms within ASM cells of different species that serve to control diverse features, including 1) [Ca2+]i contractility and relaxation, 2) cell proliferation and apoptosis, 3) production and modulation of extracellular components, and 4) release of pro- vs. anti-inflammatory mediators and factors that regulate immunity as well as the function of other airway cell types, such as epithelium, fibroblasts, and nerves. These diverse effects of ASM “activity” result in modulation of bronchoconstriction vs. bronchodilation relevant to airway hyperresponsiveness, airway thickening, and fibrosis that influence compliance. This perspective highlights recent discoveries that reveal the central role of ASM in this regard and helps set the stage for future research toward understanding the pathways regulating ASM and, in turn, the influence of ASM on airway structure and function. Such exploration is key to development of novel therapeutic strategies that influence the pathophysiology of diseases such as asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. PMID:24142517

  20. Functional effects of KCNQ K+ channels in airway smooth muscle

    PubMed Central

    Evseev, Alexey I.; Semenov, Iurii; Archer, Crystal R.; Medina, Jorge L.; Dube, Peter H.; Shapiro, Mark S.; Brenner, Robert

    2013-01-01

    KCNQ (Kv7) channels underlie a voltage-gated K+ current best known for control of neuronal excitability, and its inhibition by Gq/11-coupled, muscarinic signaling. Studies have indicated expression of KCNQ channels in airway smooth muscle (ASM), a tissue that is predominantly regulated by muscarinic receptor signaling. Therefore, we investigated the function of KCNQ channels in rodent ASM and their interplay with Gq/11-coupled M3 muscarinic receptors. Perforated-patch clamp of dissociated ASM cells detected a K+ current inhibited by the KCNQ antagonist, XE991, and augmented by the specific agonist, flupirtine. KCNQ channels begin to activate at voltages near resting potentials for ASM cells, and indeed XE991 depolarized resting membrane potentials. Muscarinic receptor activation inhibited KCNQ current weakly (~20%) at concentrations half-maximal for contractions. Thus, we were surprised to see that KCNQ had no affect on membrane voltage or muscle contractility following muscarinic activation. Further, M3 receptor-specific antagonist J104129 fumarate alone did not reveal KCNQ effects on muscarinic evoked depolarization or contractility. However, a role for KCNQ channels was revealed when BK-K+ channel activities are reduced. While KCNQ channels do control resting potentials, they appear to play a redundant role with BK calcium-activated K+ channels during ASM muscarinic signaling. In contrast to effect of antagonist, we observe that KCNQ agonist flupirtine caused a significant hyperpolarization and reduced contraction in vitro irrespective of muscarinic activation. Using non-invasive whole animal plethysmography, the clinically approved KCNQ agonist retigabine caused a transient reduction in indexes of airway resistance in both wild type and BK β1 knockout (KO) mice treated with the muscarinic agonist. These findings indicate that KCNQ channels can be recruited via agonists to oppose muscarinic evoked contractions and may be of therapeutic value as bronchodilators

  1. Functional effects of KCNQ K(+) channels in airway smooth muscle.

    PubMed

    Evseev, Alexey I; Semenov, Iurii; Archer, Crystal R; Medina, Jorge L; Dube, Peter H; Shapiro, Mark S; Brenner, Robert

    2013-01-01

    KCNQ (Kv7) channels underlie a voltage-gated K(+) current best known for control of neuronal excitability, and its inhibition by Gq/11-coupled, muscarinic signaling. Studies have indicated expression of KCNQ channels in airway smooth muscle (ASM), a tissue that is predominantly regulated by muscarinic receptor signaling. Therefore, we investigated the function of KCNQ channels in rodent ASM and their interplay with Gq/11-coupled M3 muscarinic receptors. Perforated-patch clamp of dissociated ASM cells detected a K(+) current inhibited by the KCNQ antagonist, XE991, and augmented by the specific agonist, flupirtine. KCNQ channels begin to activate at voltages near resting potentials for ASM cells, and indeed XE991 depolarized resting membrane potentials. Muscarinic receptor activation inhibited KCNQ current weakly (~20%) at concentrations half-maximal for contractions. Thus, we were surprised to see that KCNQ had no affect on membrane voltage or muscle contractility following muscarinic activation. Further, M3 receptor-specific antagonist J104129 fumarate alone did not reveal KCNQ effects on muscarinic evoked depolarization or contractility. However, a role for KCNQ channels was revealed when BK-K(+) channel activities are reduced. While KCNQ channels do control resting potentials, they appear to play a redundant role with BK calcium-activated K(+) channels during ASM muscarinic signaling. In contrast to effect of antagonist, we observe that KCNQ agonist flupirtine caused a significant hyperpolarization and reduced contraction in vitro irrespective of muscarinic activation. Using non-invasive whole animal plethysmography, the clinically approved KCNQ agonist retigabine caused a transient reduction in indexes of airway resistance in both wild type and BK β1 knockout (KO) mice treated with the muscarinic agonist. These findings indicate that KCNQ channels can be recruited via agonists to oppose muscarinic evoked contractions and may be of therapeutic value as

  2. The Three A's in Asthma - Airway Smooth Muscle, Airway Remodeling & Angiogenesis.

    PubMed

    Keglowich, L F; Borger, P

    2015-01-01

    Asthma affects more than 300 million people worldwide and its prevalence is still rising. Acute asthma attacks are characterized by severe symptoms such as breathlessness, wheezing, tightness of the chest, and coughing, which may lead to hospitalization or death. Besides the acute symptoms, asthma is characterized by persistent airway inflammation and airway wall remodeling. The term airway wall remodeling summarizes the structural changes in the airway wall: epithelial cell shedding, goblet cell hyperplasia, hyperplasia and hypertrophy of the airway smooth muscle (ASM) bundles, basement membrane thickening and increased vascular density. Airway wall remodeling starts early in the pathogenesis of asthma and today it is suggested that remodeling is a prerequisite for other asthma pathologies. The beneficial effect of bronchial thermoplasty in reducing asthma symptoms, together with the increased potential of ASM cells of asthmatics to produce inflammatory and angiogenic factors, indicate that the ASM cell is a major effector cell in the pathology of asthma. In the present review we discuss the ASM cell and its role in airway wall remodeling and angiogenesis. PMID:26106455

  3. The Three A’s in Asthma – Airway Smooth Muscle, Airway Remodeling & Angiogenesis

    PubMed Central

    Keglowich, L.F; Borger, P

    2015-01-01

    Asthma affects more than 300 million people worldwide and its prevalence is still rising. Acute asthma attacks are characterized by severe symptoms such as breathlessness, wheezing, tightness of the chest, and coughing, which may lead to hospitalization or death. Besides the acute symptoms, asthma is characterized by persistent airway inflammation and airway wall remodeling. The term airway wall remodeling summarizes the structural changes in the airway wall: epithelial cell shedding, goblet cell hyperplasia, hyperplasia and hypertrophy of the airway smooth muscle (ASM) bundles, basement membrane thickening and increased vascular density. Airway wall remodeling starts early in the pathogenesis of asthma and today it is suggested that remodeling is a prerequisite for other asthma pathologies. The beneficial effect of bronchial thermoplasty in reducing asthma symptoms, together with the increased potential of ASM cells of asthmatics to produce inflammatory and angiogenic factors, indicate that the ASM cell is a major effector cell in the pathology of asthma. In the present review we discuss the ASM cell and its role in airway wall remodeling and angiogenesis. PMID:26106455

  4. CD38 and Airway hyperresponsiveness: Studies on human airway smooth muscle cells and mouse models

    PubMed Central

    Guedes, Alonso GP; Deshpande, Deepak A; Dileepan, Mythili; Walseth, Timothy F; Panettieri, Reynold A; Subramanian, Subbaya; Kannan, Mathur S

    2015-01-01

    Asthma is an inflammatory disease in which altered calcium regulation, contractility and airway smooth muscle (ASM) proliferation contribute to airway hyperresponsiveness and airway wall remodeling. The enzymatic activity of CD38, a cell-surface protein expressed in human ASM cells, generates calcium mobilizing second messenger molecules such as cyclic ADP-ribose. CD38 expression in human ASM cells is augmented by cytokines (e.g. TNF-α) that requires activation of MAP kinases and the transcription factors, NF-ƙB and AP-1 and post-transcriptionally regulated by miR-140-3p and miR-708 by binding to 3’ Untranslated Region of CD38 as well as by modulating the activation of signaling mechanisms involved in its regulation. Mice deficient in CD38 exhibit reduced airway responsiveness to inhaled methacholine relative to response in wild-type mice. Intranasal challenge of CD38 deficient mice with TNF-α or IL-13, or the environmental fungus Alternaria alternata, causes significantly attenuated methacholine responsiveness compared to wild-type mice, with comparable airway inflammation. Reciprocal bone marrow transfer studies revealed partial restoration of airway hyperresponsiveness to inhaled methacholine in the Cd38 deficient mice. These studies provide evidence for CD38 involvement in the development of airway hyperresponsiveness, a hallmark feature of asthma. Future studies aimed at drug discovery and delivery targeting CD38 expression and/or activity are warranted. PMID:25594684

  5. Increase in passive stiffness at reduced airway smooth muscle length: potential impact on airway responsiveness.

    PubMed

    Bossé, Ynuk; Solomon, Dennis; Chin, Leslie Y M; Lian, Kevin; Paré, Peter D; Seow, Chun Y

    2010-03-01

    The amplitude of strain in airway smooth muscle (ASM) produced by oscillatory perturbations such as tidal breathing or deep inspiration (DI) influences the force loss in the muscle and is therefore a key determinant of the bronchoprotective and bronchodilatory effects of these breathing maneuvers. The stiffness of unstimulated ASM (passive stiffness) directly influences the amplitude of strain. The nature of the passive stiffness is, however, not clear. In this study, we measured the passive stiffness of ovine ASM at different muscle lengths (relative to in situ length, which was used as a reference length, L(ref)) and states of adaptation to gain insights into the origin of this muscle property. The results showed that the passive stiffness was relatively independent of muscle length, possessing a constant plateau value over a length range from 0.62 to 1.25 L(ref). Following a halving of ASM length, passive stiffness decreased substantially (by 71%) but redeveloped over time ( approximately 30 min) at the shorter length to reach 65% of the stiffness value at L(ref), provided that the muscle was stimulated to contract at least once over a approximately 30-min period. The redevelopment and maintenance of passive stiffness were dependent on the presence of Ca(2+) but unaffected by latrunculin B, an inhibitor of actin filament polymerization. The maintenance of passive stiffness was also not affected by blocking myosin cross-bridge cycling using a myosin light chain kinase inhibitor or by blocking the Rho-Rho kinase (RhoK) pathway using a RhoK inhibitor. Our results suggest that the passive stiffness of ASM is labile and capable of redevelopment following length reduction. Redevelopment and maintenance of passive stiffness following muscle shortening could contribute to airway hyperresponsiveness by attenuating the airway wall strain induced by tidal breathing and DI. PMID:20008114

  6. Does the length dependency of airway smooth muscle force contribute to airway hyperresponsiveness?

    PubMed

    Lee-Gosselin, Audrey; Pascoe, Chris D; Couture, Christian; Paré, Peter D; Bossé, Ynuk

    2013-11-01

    Airway wall remodeling and lung hyperinflation are two typical features of asthma that may alter the contractility of airway smooth muscle (ASM) by affecting its operating length. The aims of this study were as follows: 1) to describe in detail the "length dependency of ASM force" in response to different spasmogens; and 2) to predict, based on morphological data and a computational model, the consequence of this length dependency of ASM force on airway responsiveness in asthmatic subjects who have both remodeled airway walls and hyperinflated lungs. Ovine tracheal ASM strips and human bronchial rings were isolated and stimulated to contract in response to increasing concentrations of spasmogens at three different lengths. Ovine tracheal strips were more sensitive and generated greater force at longer lengths in response to acetylcholine (ACh) and K(+). Equipotent concentrations of ACh were approximately a log less for ASM stretched by 30% and approximately a log more for ASM shortened by 30%. Similar results were observed in human bronchi in response to methacholine. Morphometric and computational analyses predicted that the ASM of asthmatic subjects may be elongated by 6.6-10.4% (depending on airway generation) due to remodeling and/or hyperinflation, which could increase ACh-induced force by 1.8-117.8% (depending on ASM length and ACh concentration) and enhance the increased resistance to airflow by 0.4-4,432.8%. In conclusion, elongation of ASM imposed by airway wall remodeling and/or hyperinflation may allow ASM to operate at a longer length and to consequently generate more force and respond to lower concentration of spasmogens. This phenomenon could contribute to airway hyperresponsiveness. PMID:23970527

  7. Large conducting potassium channel reconstituted from airway smooth muscle.

    PubMed

    Savaria, D; Lanoue, C; Cadieux, A; Rousseau, E

    1992-03-01

    Microsomal fractions were prepared from canine and bovine airway smooth muscle (ASM) by differential and gradient centrifugations. Surface membrane vesicles were characterized by binding assays and incorporated into planar lipid bilayers. Single-channel activities were recorded in symmetric or asymmetric K+ buffer systems and studied under voltage and Ca2+ clamp conditions. A large-conductance K(+)-selective channel (greater than 220 pS in 150 mM K+) displaying a high Ca2+, low Ba2+, and charybdotoxin (CTX) sensitivity was identified. Time analysis of single-channel recordings revealed a complex kinetic behavior compatible with the previous schemes proposed for Ca(2+)-activated K+ channels in a variety of biological surface membranes. We now report that the open probability of the channel at low Ca2+ concentration is enhanced on in vitro phosphorylation, which is mediated via an adenosine 3',5'-cyclic monophosphate-dependent protein kinase. In addition to this characterization at the molecular level, a second series of pharmacological experiments were designed to assess the putative role of this channel in ASM strips. Our results show that 50 nM CTX, a specific inhibitor of the large conducting Ca(2+)-dependent K+ channel, prevents norepinephrine transient relaxation on carbamylcholine-precontracted ASM strips. It was also shown that CTX reversed the steady-state relaxation induced by vasoactive intestinal peptide and partially antagonized further relaxation induced by cumulative doses of this potent bronchodilatator. Thus it is proposed that the Ca(2+)-activated K+ channels have a physiological role because they are indirectly activated on stimulation of various membrane receptors via intracellular mechanisms. PMID:1372487

  8. Bitter tasting compounds dilate airways by inhibiting airway smooth muscle calcium oscillations and calcium sensitivity

    PubMed Central

    Tan, Xiahui; Sanderson, Michael J

    2014-01-01

    Background and Purpose While selective, bitter tasting, TAS2R agonists can relax agonist-contracted airway smooth muscle (ASM), their mechanism of action is unclear. However, ASM contraction is regulated by Ca2+ signalling and Ca2+ sensitivity. We have therefore investigated how the TAS2R10 agonists chloroquine, quinine and denotonium regulate contractile agonist-induced Ca2+ signalling and sensitivity. Experimental Approach Airways in mouse lung slices were contracted with either methacholine (MCh) or 5HT and bronchodilation assessed using phase-contrast microscopy. Ca2+ signalling was measured with 2-photon fluorescence microscopy of ASM cells loaded with Oregon Green, a Ca2+-sensitive indicator (with or without caged-IP3). Effects on Ca2+ sensitivity were assessed on lung slices treated with caffeine and ryanodine to permeabilize ASM cells to Ca2+. Key Results The TAS2R10 agonists dilated airways constricted by either MCh or 5HT, accompanied by inhibition of agonist-induced Ca2+ oscillations. However, in non-contracted airways, TAS2R10 agonists, at concentrations that maximally dilated constricted airways, did not evoke Ca2+ signals in ASM cells. Ca2+ increases mediated by the photolysis of caged-IP3 were also attenuated by chloroquine, quinine and denotonium. In Ca2+-permeabilized ASM cells, the TAS2R10 agonists dilated MCh- and 5HT-constricted airways. Conclusions and Implications TAS2R10 agonists reversed bronchoconstriction by inhibiting agonist-induced Ca2+ oscillations while simultaneously reducing the Ca2+ sensitivity of ASM cells. Reduction of Ca2+ oscillations may be due to inhibition of Ca2+ release through IP3 receptors. Further characterization of bronchodilatory TAS2R agonists may lead to the development of novel therapies for the treatment of bronchoconstrictive conditions. PMID:24117140

  9. [Influence of nanosize particles of cobalt ferrite on contractile responses of smooth muscle segment of airways].

    PubMed

    Kapilevich, L V; Zaĭtseva, T N; Nosarev, A V; D'iakova, E Iu; Petlina, Z R; Ogorodova, L M; Ageev, B G; Magaeva, A A; Itin, V I; Terekhova, O G; Medvedev, M A

    2012-02-01

    Contractile responses of airways segments of porpoises inhaling nanopowder CoFe2O4 were stidued by means of a mechanographic method. Inhalation of the nanosize particles of CoFe2O4 in vivo and in vitro testing the nanomaterial on isolated smooth muscles led to potentiation histaminergic, cholinergic contractile activity in airways of porpoises and to strengthening of adrenergic relaxing answers. Nanosize particles vary amplitude of hyperpotassium reductions in smooth muscle segments of airways similarly to the effect of depolymerizing drug colchicine. PMID:22650066

  10. Pulmonary surfactant in the airway physiology: a direct relaxing effect on the smooth muscle.

    PubMed

    Calkovska, A; Uhliarova, B; Joskova, M; Franova, S; Kolomaznik, M; Calkovsky, V; Smolarova, S

    2015-04-01

    Beside alveoli, surface active material plays an important role in the airway physiology. In the upper airways it primarily serves in local defense. Lower airway surfactant stabilizes peripheral airways, provides the transport and defense, has barrier and anti-edematous functions, and possesses direct relaxant effect on the smooth muscle. We tested in vitro the effect of two surfactant preparations Curosurf® and Alveofact® on the precontracted smooth muscle of intra- and extra-pulmonary airways. Relaxation was more pronounced for lung tissue strip containing bronchial smooth muscle as the primary site of surfactant effect. The study does not confirm the participation of ATP-dependent potassium channels and cAMP-regulated epithelial chloride channels known as CFTR chloride channels, or nitric oxide involvement in contractile response of smooth muscle to surfactant.By controlling wall thickness and airway diameter, pulmonary surfactant is an important component of airway physiology. Thus, surfactant dysfunction may be included in pathophysiology of asthma, COPD, or other diseases with bronchial obstruction. PMID:25583659

  11. IL-6 trans-signaling increases expression of airways disease genes in airway smooth muscle.

    PubMed

    Robinson, Mac B; Deshpande, Deepak A; Chou, Jeffery; Cui, Wei; Smith, Shelly; Langefeld, Carl; Hastie, Annette T; Bleecker, Eugene R; Hawkins, Gregory A

    2015-07-15

    Genetic data suggest that IL-6 trans-signaling may have a pathogenic role in the lung; however, the effects of IL-6 trans-signaling on lung effector cells have not been investigated. In this study, human airway smooth muscle (HASM) cells were treated with IL-6 (classical) or IL-6+sIL6R (trans-signaling) for 24 h and gene expression was measured by RNAseq. Intracellular signaling and transcription factor activation were assessed by Western blotting and luciferase assay, respectively. The functional effect of IL-6 trans-signaling was determined by proliferation assay. IL-6 trans-signaling had no effect on phosphoinositide-3 kinase and Erk MAP kinase pathways in HASM cells. Both classical and IL-6 trans-signaling in HASM involves activation of Stat3. However, the kinetics of Stat3 phosphorylation by IL-6 trans-signaling was different than classical IL-6 signaling. This was further reflected in the differential gene expression profile by IL-6 trans-signaling in HASM cells. Under IL-6 trans-signaling conditions 36 genes were upregulated, including PLA2G2A, IL13RA1, MUC1, and SOD2. Four genes, including CCL11, were downregulated at least twofold. The expression of 112 genes was divergent between IL-6 classical and trans-signaling, including the genes HILPDA, NNMT, DAB2, MUC1, WWC1, and VEGFA. Pathway analysis revealed that IL-6 trans-signaling induced expression of genes involved in regulation of airway remodeling, immune response, hypoxia, and glucose metabolism. Treatment of HASM cells with IL-6+sIL6R induced proliferation in a dose-dependent fashion, suggesting a role for IL-6 trans-signaling in asthma pathogenesis. These novel findings demonstrate differential effect of IL-6 trans-signaling on airway cells and identify IL-6 trans-signaling as a potential modifier of airway inflammation and remodeling. PMID:26001777

  12. Airway compliance and dynamics explain the apparent discrepancy in length adaptation between intact airways and smooth muscle strips.

    PubMed

    Dowie, Jackson; Ansell, Thomas K; Noble, Peter B; Donovan, Graham M

    2016-01-01

    Length adaptation is a phenomenon observed in airway smooth muscle (ASM) wherein over time there is a shift in the length-tension curve. There is potential for length adaptation to play an important role in airway constriction and airway hyper-responsiveness in asthma. Recent results by Ansell et al., 2015 (JAP 2014 10.1152/japplphysiol.00724.2014) have cast doubt on this role by testing for length adaptation using an intact airway preparation, rather than strips of ASM. Using this technique they found no evidence for length adaptation in intact airways. Here we attempt to resolve this apparent discrepancy by constructing a minimal mathematical model of the intact airway, including ASM which follows the classic length-tension curve and undergoes length adaptation. This allows us to show that (1) no evidence of length adaptation should be expected in large, cartilaginous, intact airways; (2) even in highly compliant peripheral airways, or at more compliant regions of the pressure-volume curve of large airways, the effect of length adaptation would be modest and at best marginally detectable in intact airways; (3) the key parameters which control the appearance of length adaptation in intact airways are airway compliance and the relaxation timescale. The results of this mathematical simulation suggest that length adaptation observed at the level of the isolated ASM may not clearly manifest in the normal intact airway. PMID:26376002

  13. Perturbed equilibrium of myosin binding in airway smooth muscle and its implications in bronchospasm.

    PubMed

    Fredberg, J J; Inouye, D S; Mijailovich, S M; Butler, J P

    1999-03-01

    In asthma, the mechanisms relating airway obstruction, hyperresponsiveness, and inflammation remain rather mysterious. We show here that regulation of airway smooth muscle length corresponds to a dynamically equilibrated steady state, not the static mechanical equilibrium that had been previously assumed. This dynamic steady state requires as an essential feature a continuous supply of external mechanical energy (derived from tidal lung inflations) that acts to perturb the interactions of myosin with actin, drive the molecular state of the system far away from thermodynamic equilibrium, and bias the muscle toward lengthening. This mechanism leads naturally to the suggestion that excessive airway narrowing in asthma may be associated with the destabilization of that dynamic process and its resulting collapse back to static equilibrium. With this collapse the muscle undergoes a phase transition and virtually freezes at its static equilibrium length. This mechanism may help to elucidate several unexplained phenomena including the multifactorial origins of airway hyperresponsiveness, how allergen sensitization leads to airway hyperresponsiveness, how hyperresponsiveness can persist long after airway inflammation is resolved, and the inability in asthma of deep inspirations to relax airway smooth muscle. PMID:10051279

  14. Airway smooth muscle changes in the nitrofen-induced congenital diaphragmatic hernia rat model.

    PubMed

    Belik, Jaques; Davidge, Sandra T; Zhang, Wei; Pan, Jingyi; Greer, John J

    2003-05-01

    In the fetal rat, nitrofen induces congenital diaphragmatic hernia (CDH) and pulmonary vascular remodeling similar to what is observed in the human condition. Airway hyperactivity is common in infants with CDH and attributed to the ventilator-induced airway damage. The purpose of this study was to test the hypothesis that airway smooth muscle mechanical properties are altered in the nitrofen-induced CDH rat model. Lungs from nitrofen-exposed fetuses with hernias (CDH) or intact diaphragm (nitrofen) and untreated fetuses (control) were studied on gestation d 21. The left intrapulmonary artery and bronchi were removed and mounted on a wire myograph, and lung expression, content, and immunolocalization of cyclooxygenases COX-1 and COX-2 were evaluated. Pulmonary artery muscle in the CDH group had significantly (p < 0.01) lower force generation compared with control and nitrofen groups. In contrast, the same generation bronchial smooth muscle of the CDH and nitrofen groups developed higher force compared with control. Whereas no differences were found in endothelium-dependent pulmonary vascular muscle tone, the epithelium-dependent airway muscle relaxation was significantly decreased (p < 0.01) in the CDH and nitrofen groups. The lung mRNA levels of COX-1 and COX-2 were increased in the CDH and nitrofen groups. COX-1 vascular and airway immunostaining, as well as COX-1 and COX-2 lung protein content, were increased in the CDH group. This is the first report of airway smooth muscle abnormalities in the nitrofen-induced fetal rat model of CDH. We speculate that congenital airway muscle changes may be present in the human form of this disease. PMID:12612200

  15. Airway smooth muscle NOX4 is upregulated and modulates ROS generation in COPD.

    PubMed

    Hollins, Fay; Sutcliffe, Amanda; Gomez, Edith; Berair, Rachid; Russell, Richard; Szyndralewiez, Cédric; Saunders, Ruth; Brightling, Christopher

    2016-01-01

    The burden of oxidative stress is increased in chronic obstructive pulmonary disease (COPD). However, whether the intra-cellular mechanisms controlling the oxidant/anti-oxidant balance in structural airway cells such as airway smooth muscle in COPD is altered is unclear. We sought to determine whether the expression of the NADPH oxidase (NOX)-4 is increased in airway smooth muscle in COPD both in vivo and primary cells in vitro and its role in hydrogen peroxide-induced reactive oxygen species generation. We found that in vivo NOX4 expression was up-regulated in the airway smooth muscle bundle in COPD (n = 9) and healthy controls with >20 pack year history (n = 4) compared to control subjects without a significant smoking history (n = 6). In vitro NOX4 expression was increased in airway smooth muscle cells from subjects with COPD (n = 5) compared to asthma (n = 7) and upregulated following TNF-α stimulation. Hydrogen peroxide-induced reactive oxygen species generation by airway smooth muscle cells in COPD (n = 5) was comparable to healthy controls (n = 9) but lower than asthma (n = 5); and was markedly attenuated by NOX4 inhibition. Our findings demonstrate that NOX4 expression is increased in vivo and in vitro in COPD and although we did not observe an intrinsic increase in oxidant-induced reactive oxygen species generation in COPD, it was reduced markedly by NOX4 inhibition supporting a potential therapeutic role for NOX4 in COPD. PMID:27435477

  16. A novel bronchial ring bioassay for the evaluation of small airway smooth muscle function in mice.

    PubMed

    Liu, John Q; Yang, Dennis; Folz, Rodney J

    2006-08-01

    Advances in our understanding of murine airway physiology have been hindered by the lack of suitable, ex vivo, small airway bioassay systems. In this study, we introduce a novel small murine airway bioassay system that permits the physiological and pharmacological study of intrapulmonary bronchial smooth muscle via a bronchial ring (BR) preparation utilizing BR segments as small as 200 microm in diameter. Using this ex vivo BR bioassay, we characterized small airway smooth muscle contraction and relaxation in the presence and absence of bronchial epithelium. In control BRs, the application of mechanical stretch is followed by spontaneous bronchial smooth muscle relaxation. BRs pretreated with methacholine (MCh) partially attenuate this stretch-induced relaxation by as much as 42% compared with control. MCh elicited a dose-dependent bronchial constriction with a maximal tension (E(max)) of 8.7 +/- 0.2 mN at an EC(50) of 0.33 +/- 0.02 microM. In the presence of nifedipine, ryanodine, 2-aminoethoxydiphenyl borate, and SKF-96365, E(max) to MCh was significantly reduced. In epithelium-denuded BRs, MCh-induced contraction was significantly enhanced to 11.4 +/- 1.0 mN with an EC(50) of 0.16 +/- 0.04 microM (P < 0.01). Substance P relaxed MCh-precontracted BR by 62.1%; however, this bronchial relaxation effect was completely lost in epithelium-denuded BRs. Papaverine virtually abolished MCh-induced constriction in both epithelium-intact and epithelium-denuded bronchial smooth muscle. In conclusion, this study introduces a novel murine small airway BR bioassay that allows for the physiological study of smooth muscle airway contractile responses that may aid in our understanding of the pathophysiology of asthma. PMID:16648239

  17. The impact of vitamin D on asthmatic human airway smooth muscle.

    PubMed

    Hall, Sannette C; Fischer, Kimberly D; Agrawal, Devendra K

    2016-02-01

    Asthma is a chronic heterogeneous disorder, which involves airway inflammation, airway hyperresponsiveness (AHR) and airway remodeling. The airway smooth muscle (ASM) bundle regulates the broncho-motor tone and plays a critical role in AHR as well as orchestrating inflammation. Vitamin D deficiency has been linked to increased severity and exacerbations of symptoms in asthmatic patients. It has been shown to modulate both immune and structural cells, including ASM cells, in inflammatory diseases. Given that current asthma therapies have not been successful in reversing airway remodeling, vitamin D supplementation as a potential therapeutic option has gained a great deal of attention. Here, we highlight the potential immunomodulatory properties of vitamin D in regulating ASM function and airway inflammation in bronchial asthma. PMID:26634624

  18. Epithelium-generated neuropeptide Y induces smooth muscle contraction to promote airway hyperresponsiveness.

    PubMed

    Li, Shanru; Koziol-White, Cynthia; Jude, Joseph; Jiang, Meiqi; Zhao, Hengjiang; Cao, Gaoyuan; Yoo, Edwin; Jester, William; Morley, Michael P; Zhou, Su; Wang, Yi; Lu, Min Min; Panettieri, Reynold A; Morrisey, Edward E

    2016-05-01

    Asthma is one of the most common chronic diseases globally and can be divided into presenting with or without an immune response. Current therapies have little effect on nonimmune disease, and the mechanisms that drive this type of asthma are poorly understood. Here, we have shown that loss of the transcription factors forkhead box P1 (Foxp1) and Foxp4, which are critical for lung epithelial development, in the adult airway epithelium evokes a non-Th2 asthma phenotype that is characterized by airway hyperresponsiveness (AHR) without eosinophilic inflammation. Transcriptome analysis revealed that loss of Foxp1 and Foxp4 expression induces ectopic expression of neuropeptide Y (Npy), which has been reported to be present in the airways of asthma patients, but whose importance in disease pathogenesis remains unclear. Treatment of human lung airway explants with recombinant NPY increased airway contractility. Conversely, loss of Npy in Foxp1- and Foxp4-mutant airway epithelium rescued the AHR phenotype. We determined that NPY promotes AHR through the induction of Rho kinase activity and phosphorylation of myosin light chain, which induces airway smooth muscle contraction. Together, these studies highlight the importance of paracrine signals from the airway epithelium to the underlying smooth muscle to induce AHR and suggest that therapies targeting epithelial induction of this phenotype may prove useful in treatment of noneosinophilic asthma. PMID:27088802

  19. Orai channel-mediated Ca2+ signals in vascular and airway smooth muscle.

    PubMed

    Spinelli, Amy M; Trebak, Mohamed

    2016-03-15

    Orai (Orai1, Orai2, and Orai3) proteins form a family of highly Ca(2+)-selective plasma membrane channels that are regulated by stromal-interacting molecules (STIM1 and STIM2); STIM proteins are Ca(2+) sensors located in the membrane of the endoplasmic reticulum. STIM and Orai proteins are expressed in vascular and airway smooth muscle and constitute the molecular components of the ubiquitous store-operated Ca(2+) entry pathway that mediate the Ca(2+) release-activated Ca(2+) current. STIM/Orai proteins also encode store-independent Ca(2+) entry pathways in smooth muscle. Altered expression and function of STIM/Orai proteins have been linked to vascular and airway pathologies, including restenosis, hypertension, and atopic asthma. In this review we discuss our current understanding of Orai proteins and the store-dependent and -independent signaling pathways mediated by these proteins in vascular and airway smooth muscle. We also discuss the current studies linking altered expression and function of Orai proteins with smooth muscle-related pathologies. PMID:26718630

  20. Cigarette smoke enhances proliferation and extracellular matrix deposition by human fetal airway smooth muscle

    PubMed Central

    Vogel, Elizabeth R.; VanOosten, Sarah K.; Holman, Michelle A.; Hohbein, Danielle D.; Thompson, Michael A.; Vassallo, Robert; Pandya, Hitesh C.; Prakash, Y. S.

    2014-01-01

    Cigarette smoke is a common environmental insult associated with increased risk of developing airway diseases such as wheezing and asthma in neonates and children. In adults, asthma involves airway remodeling characterized by increased airway smooth muscle (ASM) cell proliferation and increased extracellular matrix (ECM) deposition, as well as airway hyperreactivity. The effects of cigarette smoke on remodeling and contractility in the developing airway are not well-elucidated. In this study, we used canalicular-stage (18–20 wk gestational age) human fetal airway smooth muscle (fASM) cells as an in vitro model of the immature airway. fASM cells were exposed to cigarette smoke extract (CSE; 0.5–1.5% for 24–72 h), and cell proliferation, ECM deposition, and intracellular calcium ([Ca2+]i) responses to agonist (histamine 10 μM) were used to evaluate effects on remodeling and hyperreactivity. CSE significantly increased cell proliferation and deposition of ECM molecules collagen I, collagen III, and fibronectin. In contrast, [Ca2+]i responses were not significantly affected by CSE. Analysis of key signaling pathways demonstrated significant increase in extracellular signal-related kinase (ERK) and p38 activation with CSE. Inhibition of ERK or p38 signaling prevented CSE-mediated changes in proliferation, whereas only ERK inhibition attenuated the CSE-mediated increase in ECM deposition. Overall, these results demonstrate that cigarette smoke may enhance remodeling in developing human ASM through hyperplasia and ECM production, thus contributing to development of neonatal and pediatric airway disease. PMID:25344066

  1. HB-EGF-Promoted Airway Smooth Muscle Cells and Their Progenitor Migration Contribute to Airway Smooth Muscle Remodeling in Asthmatic Mouse.

    PubMed

    Wang, Qing; Li, Hequan; Yao, Yinan; Lu, Guohua; Wang, Yuehong; Xia, Dajing; Zhou, Jianying

    2016-03-01

    The airway smooth muscle (ASM) cells' proliferation, migration, and their progenitor's migration are currently regarded as causative factors for ASM remodeling in asthma. Heparin-binding epidermal growth factor (HB-EGF), a potent mitogen and chemotactic factor, could promote ASM cell proliferation through MAPK pathways. In this study, we obtained primary ASM cells and their progenitors from C57BL/6 mice and went on to explore the role of HB-EGF in these cells migration and the underlying mechanisms. We found that recombinant HB-EGF (rHB-EGF) intratracheal instillation accelerated ASM layer thickening in an OVA-induced asthmatic mouse. Modified Boyden chamber assay revealed that rHB-EGF facilitate ASM cell migration in a dose-dependent manner and ASM cells from asthmatic mice had a greater migration ability than that from normal counterparts. rHB-EGF could stimulate the phosphorylation of ERK1/2 and p38 in ASM cells but further migration assay showed that only epidermal growth factor receptor inhibitor (AG1478) or p38 inhibitor (SB203580), but not ERK1/2 inhibitor (PD98059), could inhibit rHB-EGF-mediated ASM cells migration. Actin cytoskeleton experiments exhibited that rHB-EGF could cause actin stress fibers disassembly and focal adhesions formation of ASM cells through the activation of p38. Finally, airway instillation of rHB-EGF promoted the recruitment of bone marrow-derived smooth muscle progenitor cells, which were transferred via caudal vein, migrating into the airway from the circulation. These observations demonstrated that ASM remodeling in asthma might have resulted from HB-EGF-mediated ASM cells and their progenitor cells migration, via p38 MAPK-dependent actin cytoskeleton remodeling. PMID:26826248

  2. Steroids augment relengthening of contracted airway smooth muscle: potential additional mechanism of benefit in asthma.

    PubMed

    Lakser, O J; Dowell, M L; Hoyte, F L; Chen, B; Lavoie, T L; Ferreira, C; Pinto, L H; Dulin, N O; Kogut, P; Churchill, J; Mitchell, R W; Solway, J

    2008-11-01

    Breathing (especially deep breathing) antagonises development and persistence of airflow obstruction during bronchoconstrictor stimulation. Force fluctuations imposed on contracted airway smooth muscle (ASM) in vitro result in its relengthening, a phenomenon called force fluctuation-induced relengthening (FFIR). Because breathing imposes similar force fluctuations on contracted ASM within intact lungs, FFIR represents a likely mechanism by which breathing antagonises bronchoconstriction. While this bronchoprotective effect appears to be impaired in asthma, corticosteroid treatment can restore the ability of deep breaths to reverse artificially induced bronchoconstriction in asthmatic subjects. It has previously been demonstrated that FFIR is physiologically regulated through the p38 mitogen-activated protein kinase (MAPK) signalling pathway. While the beneficial effects of corticosteroids have been attributed to suppression of airway inflammation, the current authors hypothesised that alternatively they might exert their action directly on ASM by augmenting FFIR as a result of inhibiting p38 MAPK signalling. This possibility was tested in the present study by measuring relengthening in contracted canine tracheal smooth muscle (TSM) strips. The results indicate that dexamethasone treatment significantly augmented FFIR of contracted canine TSM. Canine tracheal ASM cells treated with dexamethasone demonstrated increased MAPK phosphatase-1 expression and decreased p38 MAPK activity, as reflected in reduced phosphorylation of the p38 MAPK downstream target, heat shock protein 27. These results suggest that corticosteroids may exert part of their therapeutic effect through direct action on airway smooth muscle, by decreasing p38 mitogen-activated protein kinase activity and thus increasing force fluctuation-induced relengthening. PMID:18768574

  3. Iptakalim inhibits PDGF-BB-induced human airway smooth muscle cells proliferation and migration

    SciTech Connect

    Liu, Wenrui; Kong, Hui; Zeng, Xiaoning; Wang, Jingjing; Wang, Zailiang; Yan, Xiaopei; Wang, Yanli; Xie, Weiping Wang, Hong

    2015-08-15

    Chronic airway diseases are characterized by airway remodeling which is attributed partly to the proliferation and migration of airway smooth muscle cells (ASMCs). ATP-sensitive potassium (K{sub ATP}) channels have been identified in ASMCs. Mount evidence has suggested that K{sub ATP} channel openers can reduce airway hyperresponsiveness and alleviate airway remodeling. Opening K{sup +} channels triggers K{sup +} efflux, which leading to membrane hyperpolarization, preventing Ca{sup 2+}entry through closing voltage-operated Ca{sup 2+} channels. Intracellular Ca{sup 2+} is the most important regulator of muscle contraction, cell proliferation and migration. K{sup +} efflux decreases Ca{sup 2+} influx, which consequently influences ASMCs proliferation and migration. As a K{sub ATP} channel opener, iptakalim (Ipt) has been reported to restrain the proliferation of pulmonary arterial smooth muscle cells (PASMCs) involved in vascular remodeling, while little is known about its impact on ASMCs. The present study was designed to investigate the effects of Ipt on human ASMCs and the mechanisms underlying. Results obtained from cell counting kit-8 (CCK-8), flow cytometry and 5-ethynyl-2′-deoxyuridine (EdU) incorporation showed that Ipt significantly inhibited platelet-derived growth factor (PDGF)-BB-induced ASMCs proliferation. ASMCs migration induced by PDGF-BB was also suppressed by Ipt in transwell migration and scratch assay. Besides, the phosphorylation of Ca{sup 2+}/calmodulin-dependent kinase II (CaMKII), extracellular regulated protein kinases 1/2 (ERK1/2), protein kinase B (Akt), and cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) were as well alleviated by Ipt administration. Furthermore, we found that the inhibition of Ipt on the PDGF-BB-induced proliferation and migration in human ASMCs was blocked by glibenclamide (Gli), a selective K{sub ATP} channel antagonist. These findings provide a strong evidence to support that Ipt

  4. Peripheral Airway Smooth Muscle, but Not the Trachealis, Is Hypercontractile in an Equine Model of Asthma.

    PubMed

    Matusovsky, Oleg S; Kachmar, Linda; Ijpma, Gijs; Bates, Genevieve; Zitouni, Nedjma; Benedetti, Andrea; Lavoie, Jean-Pierre; Lauzon, Anne-Marie

    2016-05-01

    Heaves is a naturally occurring equine disease that shares many similarities with human asthma, including reversible antigen-induced bronchoconstriction, airway inflammation, and remodeling. The purpose of this study was to determine whether the trachealis muscle is mechanically representative of the peripheral airway smooth muscle (ASM) in an equine model of asthma. Tracheal and peripheral ASM of heaves-affected horses under exacerbation, or under clinical remission of the disease, and control horses were dissected and freed of epithelium to measure unloaded shortening velocity (Vmax), stress (force/cross-sectional area), methacholine effective concentration at which 50% of the maximum response is obtained, and stiffness. Myofibrillar Mg(2+)-ATPase activity, actomyosin in vitro motility, and contractile protein expression were also measured. Horses with heaves had significantly greater Vmax and Mg(2+)-ATPase activity in peripheral airway but not in tracheal smooth muscle. In addition, a significant correlation was found between Vmax and the time elapsed since the end of the corticosteroid treatment for the peripheral airways in horses with heaves. Maximal stress and stiffness were greater in the peripheral airways of the horses under remission compared with controls and the horses under exacerbation, potentially due to remodeling. Actomyosin in vitro motility was not different between controls and horses with heaves. These data demonstrate that peripheral ASM is mechanically and biochemically altered in heaves, whereas the trachealis behaves as in control horses. It is therefore conceivable that the trachealis muscle may not be representative of the peripheral ASM in human asthma either, but this will require further investigation. PMID:26473389

  5. A study of airway smooth muscle in asthmatic and non-asthmatic airways using PS-OCT (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Adams, David C.; Holz, Jasmin A.; Szabari, Margit V.; Hariri, Lida P.; Harris, R. Scott; Cho, Jocelyn L.; Hamilos, Daniel L.; Luster, Andrew D.; Medoff, Benjamin D.; Suter, Melissa J.

    2016-03-01

    Present understanding of the pathophysiological mechanisms of asthma has been severely limited by the lack of an imaging modality capable of assessing airway conditions of asthma patients in vivo. Of particular interest is the role that airway smooth muscle (ASM) plays in the development of asthma and asthma related symptoms. With standard Optical Coherence Tomography (OCT), imaging ASM is often not possible due to poor structural contrast between the muscle and surrounding tissues. A potential solution to this problem is to utilize additional optical contrast factors intrinsic to the tissue, such as birefringence. Due to its highly ordered structure, ASM is strongly birefringent. Previously, we demonstrated that Polarization Sensitive OCT(PS-OCT) has the potential to be used to visualize ASM as well as easily segment it from the surrounding (weakly) birefringent tissue by exploiting a property which allows it to discriminate the orientation of birefringent fibers. We have already validated our technology with a substantial set of histological comparisons made against data obtained ex vivo. In this work we present a comprehensive comparison of ASM distributions in asthmatic and non-asthmatic human volunteers. By isolating the ASM we parameterize its distribution in terms of both thickness and band width, calculated volumetrically over centimeters of airway. Using this data we perform analyses of the asthmatic and non-asthmatic airways using a broad number and variety and subjects.

  6. c-Myc regulates proliferation and Fgf10 expression in airway smooth muscle after airway epithelial injury in mouse.

    PubMed

    Volckaert, Thomas; Campbell, Alice; De Langhe, Stijn

    2013-01-01

    During lung development, Fibroblast growth factor 10 (Fgf10), which is expressed in the distal mesenchyme and regulated by Wnt signaling, acts on the distal epithelial progenitors to maintain them and prevent them from differentiating into proximal (airway) epithelial cells. Fgf10-expressing cells in the distal mesenchyme are progenitors for parabronchial smooth muscle cells (PSMCs). After naphthalene, ozone or bleomycin-induced airway epithelial injury, surviving epithelial cells secrete Wnt7b which then activates the PSMC niche to induce Fgf10 expression. This Fgf10 secreted by the niche then acts on a subset of Clara stem cells to break quiescence, induce proliferation and initiate epithelial repair. Here we show that conditional deletion of the Wnt target gene c-Myc from the lung mesenchyme during development does not affect proper epithelial or mesenchymal differentiation. However, in the adult lung we show that after naphthalene-mediated airway epithelial injury c-Myc is important for the activation of the PSMC niche and as such induces proliferation and Fgf10 expression in PSMCs. Our data indicate that conditional deletion of c-Myc from PSMCs inhibits airway epithelial repair, whereas c-Myc ablation from Clara cells has no effect on airway epithelial regeneration. These findings may have important implications for understanding the misregulation of lung repair in asthma and COPD. PMID:23967208

  7. Steroids and antihistamines synergize to inhibit rat's airway smooth muscle contractility.

    PubMed

    Liu, Shao-Cheng; Chu, Yueng-Hsiang; Kao, Chuan-Hsiang; Wu, Chi-Chung; Wang, Hsing-Won

    2015-06-01

    Both glucocorticoids and H1-antihistamines were widely used on patients with allergic rhinitis (AR) and obstructive airway diseases. However, their direct effects on airway smooth muscle were not fully explored. In this study, we tested the effectiveness of prednisolone (Kidsolone) and levocetirizine (Xyzal) on isolated rat trachea submersed in Kreb's solution in a muscle bath. Changes in tracheal contractility in response to the application of parasympathetic mimetic agents were measured. The following assessments of the drug were performed: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10(-6) M methacholine; (3) effect of the drug on electrical field stimulation (EFS) induced tracheal smooth muscle contractions. The result revealed sole use of Kidsolone or Xyzal elicited no significant effect or only a little relaxation response on tracheal tension after methacholine treatment. The tension was 90.5 ± 7.5 and 99.5 ± 0.8 % at 10(-4) M for Xyzal and 10(-5) M for Kidsolone, respectively. However, a dramatically spasmolytic effect was observed after co-administration of Kidsolone and Xyzal and the tension dropped to 67.5 ± 13.6 %, with statistical significance (p < 0.05). As for EFS-induced contractions, Kidsolone had no direct effect but Xyzal could inhibit it, with increasing basal tension. In conclusion, using glucocorticoids alone had no spasmolytic effect but they can be synergized with antihistamines to dramatically relax the trachea smooth muscle within minutes. Therefore, for AR patients with acute asthma attack, combined use of those two drugs is recommended. PMID:25115316

  8. How the airway smooth muscle in cystic fibrosis reacts in proinflammatory conditions: implications for airway hyper-responsiveness and asthma in cystic fibrosis.

    PubMed

    McCuaig, Sarah; Martin, James G

    2013-04-01

    Among patients with cystic fibrosis there is a high prevalence (40-70%) of asthma signs and symptoms such as cough and wheezing and airway hyper-responsiveness to inhaled histamine or methacholine. Whether these abnormal airway responses are due to a primary deficiency in the cystic fibrosis transmembrane conductance regulator (CFTR) or are secondary to the inflammatory environment in the cystic fibrosis lungs is not clear. A role for the CFTR in smooth muscle function is emerging, and alterations in contractile signalling have been reported in CFTR-deficient airway smooth muscle. Persistent bacterial infection, especially with Pseudomonas aeruginosa, stimulates interleukin-8 release from the airway epithelium, resulting in neutrophilic inflammation. Increased neutrophilia and skewing of CFTR-deficient T-helper cells to type 2 helper T cells creates an inflammatory environment characterised by high concentrations of tumour necrosis factor α, interleukin-8, and interleukin-13, which might all contribute to increased contractility of airway smooth muscle in cystic fibrosis. An emerging role of interleukin-17, which is raised in patients with cystic fibrosis, in airway smooth muscle proliferation and hyper-responsiveness is apparent. Increased understanding of the molecular mechanisms responsible for the altered smooth muscle physiology in patients with cystic fibrosis might provide insight into airway dysfunction in this disease. PMID:24429094

  9. The effects of cannabidiol on the antigen-induced contraction of airways smooth muscle in the guinea-pig.

    PubMed

    Dudášová, A; Keir, S D; Parsons, M E; Molleman, A; Page, C P

    2013-06-01

    (-)-Δ(9)-Tetrahydrocannabinol has been demonstrated to have beneficial effects in the airways, but its psychoactive effects preclude its therapeutic use for the treatment of airways diseases. In the present study we have investigated the effects of (-)-cannabidiol, a non-psychoactive component of cannabis for its actions on bronchial smooth muscle in vitro and in vivo. Guinea-pig bronchial smooth muscle contractions induced by exogenously applied spasmogens were measured isometrically. In addition, contractile responses of bronchial smooth muscle from ovalbumin-sensitized guinea-pigs were investigated in the absence or presence of (-)-cannabidiol. Furthermore, the effect of (-)-cannabidiol against ovalbumin-induced airway obstruction was investigated in vivo in ovalbumin-sensitized guinea-pigs. (-)-Cannabidiol did not influence the bronchial smooth muscle contraction induced by carbachol, histamine or neurokinin A. In contrast, (-)-cannabidiol inhibited anandamide- and virodhamine-induced responses of isolated bronchi. A fatty acid amide hydrolase inhibitor, phenylmethanesulfonyl fluoride reversed the inhibitory effect of (-)-cannabidiol on anandamide-induced contractions. In addition, (-)-cannabidiol inhibited the contractile response of bronchi obtained from allergic guinea-pigs induced by ovalbumin. In vivo, (-)-cannabidiol reduced ovalbumin-induced airway obstruction. In conclusion, our results suggest that cannabidiol can influence antigen-induced airway smooth muscle tone suggesting that this molecule may have beneficial effects in the treatment of obstructive airway disorders. PMID:23428645

  10. Regulation of actin dynamics by WNT-5A: implications for human airway smooth muscle contraction

    PubMed Central

    Koopmans, Tim; Kumawat, Kuldeep; Halayko, Andrew J; Gosens, Reinoud

    2016-01-01

    A defining feature of asthma is airway hyperresponsiveness (AHR), which underlies the exaggerated bronchoconstriction response of asthmatics. The role of the airway smooth muscle (ASM) in AHR has garnered increasing interest over the years, but how asthmatic ASM differs from healthy ASM is still an active topic of debate. WNT-5A is increasingly expressed in asthmatic ASM and has been linked with Th2-high asthma. Due to its link with calcium and cytoskeletal remodelling, we propose that WNT-5A may modulate ASM contractility. We demonstrated that WNT-5A can increase maximum isometric tension in bovine tracheal smooth muscle strips. In addition, we show that WNT-5A is preferentially expressed in contractile human airway myocytes compared to proliferative cells, suggesting an active role in maintaining contractility. Furthermore, WNT-5A treatment drives actin polymerisation, but has no effect on intracellular calcium flux. Next, we demonstrated that WNT-5A directly regulates TGF-β1-induced expression of α-SMA via ROCK-mediated actin polymerization. These findings suggest that WNT-5A modulates fundamental mechanisms that affect ASM contraction and thus may be of relevance for AHR in asthma. PMID:27468699

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

    PubMed

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

    2015-06-01

    Multiple pulmonary conditions are characterized by an abnormal misbalance between various tissue components, for example, an increase in the fibrous connective tissue and loss/increase in extracellular matrix proteins (ECM). Such tissue remodeling may adversely impact physiological function of airway smooth muscle cells (ASMCs) responsible for contraction of airways and release of a variety of bioactive molecules. However, few efforts have been made to understand the potentially significant impact of tissue remodeling on ASMCs. Therefore, this study reports how ASMCs respond to a change in mechanical stiffness of a matrix, to which ASMCs adhere because mechanical stiffness of the remodeled airways is often different from the physiological stiffness. Accordingly, using atomic force microscopy (AFM) measurements, we found that the elastic modulus of the mouse bronchus has an arithmetic mean of 23.1 ± 14 kPa (SD) (median 18.6 kPa). By culturing ASMCs on collagen-conjugated polyacrylamide hydrogels with controlled elastic moduli, we found that gels designed to be softer than average airway tissue significantly increased cellular secretion of vascular endothelial growth factor (VEGF). Conversely, gels stiffer than average airways stimulated cell proliferation, while reducing VEGF secretion and agonist-induced calcium responses of ASMCs. These dependencies of cellular activities on elastic modulus of the gel were correlated with changes in the expression of integrin-β1 and integrin-linked kinase (ILK). Overall, the results of this study demonstrate that changes in matrix mechanics alter cell proliferation, calcium signaling, and proangiogenic functions in ASMCs. PMID:25724668

  12. Smooth muscle in human bronchi is disposed to resist airway distension.

    PubMed

    Gazzola, Morgan; Henry, Cyndi; Couture, Christian; Marsolais, David; King, Gregory G; Fredberg, Jeffrey J; Bossé, Ynuk

    2016-07-15

    Studying airway smooth muscle (ASM) in conditions that emulate the in vivo environment within which the bronchi normally operate may provide important clues regarding its elusive physiological function. The present study examines the effect of lengthening and shortening of ASM on tension development in human bronchial segments. ASM from each bronchial segment was set at a length approximating in situ length (Linsitu). Bronchial tension was then measured during a slow cyclical strain (0.004Hz, from 0.7Linsitu to 1.3Linsitu) in the relaxed state and at graded levels of activation by methacholine. In all cases, tension was greater at longer ASM lengths, and greater during lengthening than shortening. The threshold of methacholine concentration that was required for ASM to account for bronchial tension across the entire range of ASM lengths tested was on average smaller by 2.8 logs during lengthening than during shortening. The length-dependency of ASM tension, together with this lower threshold of methacholine concentration during lengthening versus shortening, suggest that ASM has a greater ability to resist airway dilation during lung inflation than to narrow the airways during lung deflation. More than serving to narrow the airway, as has long been thought, these data suggest that the main function of ASM contraction is to limit airway wall distension during lung inflation. PMID:27095271

  13. Fetal human airway smooth muscle cell production of leukocyte chemoattractants is differentially regulated by fluticasone

    PubMed Central

    Pearson, Helen; Britt, Rodney D.; Pabelick, Christine M.; Prakash, Y.S.; Amrani, Yassine; Pandya, Hitesh C.

    2016-01-01

    Background Adult human airway smooth muscle (ASM) produce cytokines involved in recruitment and survival of leukocytes within airway walls. Cytokine generation by adult ASM is glucocorticoid-sensitive. Whether developing lung ASM produces cytokines in a glucocorticoid-sensitive fashion is unknown. Methods Cultured fetal human ASM cells stimulated with TNF-α (0–20 ng/ml) were incubated with TNF-α receptor-blocking antibodies, fluticasone (1 and 100 nm), or vehicle. Supernatants and cells were assayed for the production of CCL5, CXCL10, and CXCL8 mRNA and protein and glucocorticoid receptor phosphorylation. Results CCL5, CXCL10, and CXCL8 mRNA and protein production by fetal ASM cell was significantly and dose-dependently following TNF-α treatment. Cytokine mRNA and protein production were effectively blocked by TNF-α R1 and R2 receptor neutralizing antibodies but variably inhibited by fluticasone. TNF-α-induced TNF-R1 and R2 receptor mRNA expression was only partially attenuated by fluticasone. Glucocorticoid receptor phosphorylation at serine (Ser) 211 but not at Ser 226 was enhanced by fluticasone. Conclusion Production of CCL5, CXCL10, and CXCL8 by fetal ASM appears to involve pathways that are both qualitatively and mechanistically distinct to those described for adult ASM. The findings imply developing ASM has potential to recruit leukocyte into airways and, therefore, of relevance to childhood airway diseases. PMID:26331770

  14. IL-1β: a key modulator in asthmatic airway smooth muscle hyper-reactivity.

    PubMed

    Liao, Zhi; Xiao, Hong-tao; Zhang, Yuan; Tong, Rong-Sheng; Zhang, Li-Juan; Bian, Yuan; He, Xia

    2015-08-01

    Asthma is a chronic inflammatory disorder of the airway. It is characterized by airway hyper-reactivity, which can be attributed to the chronically inflamed airway. However, the molecular mechanism is still under investigation. In this article, we have shown that IL-1β is a key molecule that can orchestrate both Toll-like receptor and muscarinic receptor pathways, and that antagonizing the function of IL-1β has a promising future as a potential drug target for asthma treatment. IL-1β can activate NF-κB pathways via Toll-like receptors, and NF-κB will eventually transactivate the genes of cytokines, chemokines, proteins of the complement system, adhesion molecules and immune receptors involved in inflammation. IL-1β can activate eosinophils, which can release major basic protein (MBP) to antagonize the M2 receptors leading to excessive acetylcholine release. Acetylcholine has an effect on M3 receptors, which are related to airway smooth muscle contraction and mucus production. IL-1β is reported to activate COX-2 resulting in heterologous desensitization of adenylate cyclase and impairs relaxation of the ASM. IL-1β is involved in mediation of neutrophilic inflammation. Identification of the prominent role of IL-1β in asthma could lead to successful use of anti-IL1β agents. PMID:26134749

  15. Assays for in vitro monitoring of proliferation of human airway smooth muscle (ASM) and human pulmonary arterial vascular smooth muscle (VSM) cells.

    PubMed

    Goncharova, Elena A; Lim, Poay; Goncharov, Dmitry A; Eszterhas, Andrew; Panettieri, Reynold A; Krymskaya, Vera P

    2006-01-01

    Vascular and airway remodeling, which are characterized by airway smooth muscle (ASM) and pulmonary arterial vascular smooth muscle (VSM) proliferation, contribute to the pathology of asthma, pulmonary hypertension, restenosis and atherosclerosis. To evaluate the proliferation of VSM and ASM cells in response to mitogens, we perform a [3H]thymidine incorporation assay. The proliferation protocol takes approximately 48 h and includes stimulating cells synchronized in G0/G1 phase of the cell cycle with agonists, labeling cells with [3H]thymidine and examining levels of [3H]thymidine incorporation by scintillation counting. Although using radiolabeled [3H]thymidine incorporation is a limitation, the greatest benefit of the assay is providing reliable and statistically significant data. PMID:17406550

  16. Endobronchial Ultrasound Reliably Quantifies Airway Smooth Muscle Remodeling in an Equine Asthma Model.

    PubMed

    Bullone, Michela; Beauchamp, Guy; Godbout, Mireille; Martin, James G; Lavoie, Jean-Pierre

    2015-01-01

    Endobronchial ultrasonography (EBUS) revealed differences in the thickness of the layer representing subepithelial tissues (L2) between human asthmatics and controls, but whether this measurement correlates with airway smooth muscle (ASM) remodeling in asthma is unknown. In this study, we sought to determine the ability of EBUS to predict histological ASM remodeling in normal and equine asthmatic airways. We studied 109 isolated bronchi from the lungs of 13 horses. They underwent EBUS examination using a 30 MHz radial probe before being processed for histology. ASM remodeling parameters were evaluated in EBUS images (L2 thickness, L2 area, L2 area/internal perimeter [Pi] and L2 area/Pi2) and histological cuts (ASM area/Pi2), and compared. EBUS was then performed ex vivo on the lungs of 4 horses with heaves, an asthma-like condition of horses, and 7 controls to determine whether central bronchial remodeling could be detected with this technique. An optimized approach was developed based on data variability within airways, subjects, and groups, and then validated in 7 horses (3 controls, 4 with heaves) that underwent EBUS in vivo. L2 area was significantly associated to ASM area in isolated lungs (p<0.0001), in the absence of significant bias related to the airway size. Bronchial size significantly affected EBUS ASM-related parameters, except for L2 area/Pi2. L2 area/Pi2 was increased in the airways of asthmatic horses compared to controls, both ex vivo and in vivo (p<0.05). Bronchial histology confirmed our findings (AASM/Pi2 was increased in asthmatic horses compared to controls, p<0.05). In both horses with heaves and controls, L2 was composed of ASM for the outer 75% of its thickness and by ECM for the remaining inner 25%. In conclusion, EBUS reliably allows assessment of asthma-associated ASM remodeling of central airways in a non-invasive way. PMID:26348727

  17. Endobronchial Ultrasound Reliably Quantifies Airway Smooth Muscle Remodeling in an Equine Asthma Model

    PubMed Central

    Bullone, Michela; Beauchamp, Guy; Godbout, Mireille; Martin, James G.; Lavoie, Jean-Pierre

    2015-01-01

    Endobronchial ultrasonography (EBUS) revealed differences in the thickness of the layer representing subepithelial tissues (L2) between human asthmatics and controls, but whether this measurement correlates with airway smooth muscle (ASM) remodeling in asthma is unknown. In this study, we sought to determine the ability of EBUS to predict histological ASM remodeling in normal and equine asthmatic airways. We studied 109 isolated bronchi from the lungs of 13 horses. They underwent EBUS examination using a 30 MHz radial probe before being processed for histology. ASM remodeling parameters were evaluated in EBUS images (L2 thickness, L2 area, L2 area/internal perimeter [Pi] and L2 area/Pi2) and histological cuts (ASM area/Pi2), and compared. EBUS was then performed ex vivo on the lungs of 4 horses with heaves, an asthma-like condition of horses, and 7 controls to determine whether central bronchial remodeling could be detected with this technique. An optimized approach was developed based on data variability within airways, subjects, and groups, and then validated in 7 horses (3 controls, 4 with heaves) that underwent EBUS in vivo. L2 area was significantly associated to ASM area in isolated lungs (p<0.0001), in the absence of significant bias related to the airway size. Bronchial size significantly affected EBUS ASM-related parameters, except for L2 area/Pi2. L2 area/Pi2 was increased in the airways of asthmatic horses compared to controls, both ex vivo and in vivo (p<0.05). Bronchial histology confirmed our findings (AASM/Pi2 was increased in asthmatic horses compared to controls, p<0.05). In both horses with heaves and controls, L2 was composed of ASM for the outer 75% of its thickness and by ECM for the remaining inner 25%. In conclusion, EBUS reliably allows assessment of asthma-associated ASM remodeling of central airways in a non-invasive way. PMID:26348727

  18. Triptolide inhibits TGF-β1-induced cell proliferation in rat airway smooth muscle cells by suppressing Smad signaling

    SciTech Connect

    Chen, Ming; Lv, Zhiqiang; Huang, Linjie; Zhang, Wei; Lin, Xiaoling; Shi, Jianting; Zhang, Wei; Liang, Ruiyun; Jiang, Shanping

    2015-02-15

    Background: We have reported that triptolide can inhibit airway remodeling in a murine model of asthma via TGF-β1/Smad signaling. In the present study, we aimed to investigate the effect of triptolide on airway smooth muscle cells (ASMCs) proliferation and the possible mechanism. Methods: Rat airway smooth muscle cells were cultured and made synchronized, then pretreated with different concentration of triptolide before stimulated by TGF-β1. Cell proliferation was evaluated by MTT assay. Flow cytometry was used to study the influence of triptolide on cell cycle and apoptosis. Signal proteins (Smad2, Smad3 and Smad7) were detected by western blotting analysis. Results: Triptolide significantly inhibited TGF-β1-induced ASMC proliferation (P<0.05). The cell cycle was blocked at G1/S-interphase by triptolide dose dependently. No pro-apoptotic effects were detected under the concentration of triptolide we used. Western blotting analysis showed TGF-β1 induced Smad2 and Smad3 phosphorylation was inhibited by triptolide pretreatment, and the level of Smad7 was increased by triptolide pretreatment. Conclusions: Triptolide may function as an inhibitor of asthma airway remodeling by suppressing ASMCs proliferation via negative regulation of Smad signaling pathway. - Highlights: • In this study, rat airway smooth muscle cells were cultured and made synchronized. • Triptolide inhibited TGF-β1-induced airway smooth muscle cells proliferation. • Triptolide inhibited ASMCs proliferation via negative regulation of Smad signaling pathway.

  19. Airway hyperresponsiveness in asthma: a problem of limited smooth muscle relaxation with inspiration.

    PubMed Central

    Skloot, G; Permutt, S; Togias, A

    1995-01-01

    We hypothesized that hyperresponsiveness in asthma is caused by an impairment in the ability of inspiration to stretch airway smooth muscle. If the hypothesis was correct, we reasoned that the sensitivity to inhaled methacholine in normal and asthmatic subjects should be the same if the challenge was carried out under conditions where deep inspirations were prohibited. 10 asthmatic and 10 normal subjects received increasing concentrations of inhaled methacholine under conditions where forced expirations from a normal end-tidal inspiration were performed. When no deep inspirations were allowed, the response to methacholine was similar in the normal and asthmatic subjects, compatible with the hypothesis we propose. Completely contrary to our expectations, however, was the marked responsivity to methacholine that remained in the normal subjects after deep breaths were initiated. 6 of the 10 normal subjects had > 20% reduction in forced expiratory volume in one second (FEV 1) at doses of methacholine < 8 mg/ml, whereas there was < 15% reduction with 75 mg/ml during routine challenge. The ability of normal subjects to develop asthmatic responses when the modulating effects of increases in lung volume was voluntarily suppressed suggests that an intrinsic impairment of the ability of inspiration to stretch airway smooth muscle is a major feature of asthma. PMID:7593627

  20. A Synthetic Chloride Channel Relaxes Airway Smooth Muscle of the Rat

    PubMed Central

    Yau, Kwok-hei; Mak, Judith Choi-wo; Leung, Susan Wai-sum; Yang, Dan; Vanhoutte, Paul M.

    2012-01-01

    Synthetic ion channels may have potential therapeutic applications, provided they possess appropriate biological activities. The present study was designed to examine the ability of small molecule-based synthetic Cl– channels to modulate airway smooth muscle responsiveness. Changes in isometric tension were measured in rat tracheal rings. Relaxations to the synthetic chloride channel SCC-1 were obtained during sustained contractions to KCl. The anion dependency of the effect of SCC-1 was evaluated by ion substitution experiments. The sensitivity to conventional Cl– transport inhibitors was also tested. SCC-1 caused concentration-dependent relaxations during sustained contractions to potassium chloride. This relaxing effect was dependent on the presence of extracellular Cl– and HCO3−. It was insensitive to conventional Cl– channels/transport inhibitors that blocked the cystic fibrosis transmembrane conductance regulator and calcium-activated Cl– channels. SCC-1 did not inhibit contractions induced by carbachol, endothelin-1, 5-hydroxytryptamine or the calcium ionophore A23187. SCC-1 relaxes airway smooth muscle during contractions evoked by depolarizing solutions. The Cl– conductance conferred by this synthetic compound is distinct from the endogenous transport systems for chloride anions. PMID:23049786

  1. Effect of airway inflammation on smooth muscle shortening and contractility in guinea pig trachealis.

    PubMed

    Mitchell, R W; Ndukwu, I M; Arbetter, K; Solway, J; Leff, A R

    1993-12-01

    We studied the effect of either 1) immunogenic inflammation caused by aerosolized ovalbumin or 2) neurogenic inflammation caused by aerosolized capsaicin in vivo on guinea pig tracheal smooth muscle (TSM) contractility in vitro. Force-velocity relationships were determined for nine epithelium-intact TSM strips from ovalbumin-sensitized (OAS) vs. seven sham-sensitized controls and TSM strips for seven animals treated with capsaicin aerosol (Cap-Aer) vs. eight sham controls. Muscle strips were tethered to an electromagnetic lever system, which allowed isotonic shortening when load clamps [from 0 to maximal isometric force (Po)] were applied at specific times after onset of contraction. Contractions were elicited by supramaximal electrical field stimulation (60 Hz, 10-s duration, 18 V). Optimal length for each muscle was determined during equilibration. Maximal shortening velocity (Vmax) was increased in TSM from OAS (1.72 +/- 0.46 mm/s) compared with sham-sensitized animals (0.90 +/- 0.15 mm/s, P < 0.05); Vmax for TSM from Cap-Aer (0.88 +/- 0.11 mm/s) was not different from control TSM (1.13 +/- 0.08 mm/s, P = NS). Similarly, maximal shortening (delta max) was augmented in TSM from OAS (1.01 +/- 0.15 mm) compared with sham-sensitized animals (0.72 +/- 0.14 mm, P < 0.05); delta max for TSM from Cap-Aer animals (0.65 +/- 0.11 mm) was not different from saline aerosol controls (0.71 +/- 0.15 mm, P = NS). We demonstrate Vmax and delta max are augmented in TSM after ovalbumin sensitization; in contrast, neurogenic inflammation caused by capsaicin has no effect on isolated TSM contractility in vitro. These data suggest that airway hyperresponsiveness in vivo that occurs in association with immunogenic or neurogenic inflammation may result from different effects of these types of inflammation on airway smooth muscle. PMID:8279571

  2. M2 Muscarinic acetylcholine receptor modulates rat airway smooth muscle cell proliferation

    PubMed Central

    2013-01-01

    Airways chronic inflammatory conditions in asthma and COPD are characterized by tissue remodeling, being smooth muscle hyperplasia, the most important feature. Non-neuronal and neuronal Acetylcholine acting on muscarinic receptors (MAChRs) has been postulated as determinant of tissue remodeling in asthma and COPD by promoting proliferation and phenotypic changes of airway smooth muscle cells (ASMC). The objective was to evaluate proliferative responses to muscarinic agonist as carbamylcholine (Cch) and to identify the MAchR subtype involved. ASMC were isolated from tracheal fragments of Sprague–Dawley rats by enzymatic digestion. Proliferation assays were performed by MTS-PMS method. Viability was confirmed by trypan blue exclusion method. Mitogens as, epidermal growth factor (EGF), Tumor necrosis factor-alpha (TNF-α) and fetal bovine serum (FBS) increased ASMC proliferation (p < 0.05, n = 5). Cch alone increased ASMC proliferation at 24 and 48 hrs. However, combination of Cch with other mitogens exhibited a dual effect, synergistic proliferation effect in the presence of EGF (5 ng/mL) and 5% FBS and inhibiting the proliferation induced by 10% FBS, EGF (10 ng/mL) and TNF-α (10 ng/mL). To determine the MAChR subtype involved in these biological responses, a titration curve of selective muscarinic antagonists were performed. The Cch stimulatory and inhibitory effects on ASCM proliferation was blocked by AF-DX-116 (M2AChR selective antagonist), in greater proportion than 4-DAMP (M3AChR selective antagonist), suggesting that the modulation of muscarinic agonist-induced proliferation is M2AChR mediated responses. Thus, M2AChR can activate multiple signal transduction systems and mediate both effects on ASMC proliferation depending on the plethora and variable airway microenvironments existing in asthma and COPD. PMID:24377382

  3. Sex Steroids Influence Brain-Derived Neurotropic Factor Secretion From Human Airway Smooth Muscle Cells.

    PubMed

    Wang, Sheng-Yu; Freeman, Michelle R; Sathish, Venkatachalem; Thompson, Michael A; Pabelick, Christina M; Prakash, Y S

    2016-07-01

    Brain derived neurotropic factor (BDNF) is emerging as an important player in airway inflammation, remodeling, and hyperreactivity. Separately, there is increasing evidence that sex hormones contribute to pathophysiology in the lung. BDNF and sex steroid signaling are thought to be intricately linked in the brain. There is currently little information on BDNF and sex steroid interactions in the airway but is relevant to understanding growth factor signaling in the context of asthma in men versus women. In this study, we assessed the effect of sex steroids on BDNF expression and secretion in human airway smooth muscle (ASM). Human ASM was treated with estrogen (E2 ) or testosterone (T, 10 nM each) and intracellular BDNF and secreted BDNF measured. E2 and T significantly reduced secretion of BDNF; effects prevented by estrogen and androgen receptor inhibitor, ICI 182,780 (1 μM), and flutamide (10 μM), respectively. Interestingly, no significant changes were observed in intracellular BDNF mRNA or protein expression. High affinity BDNF receptor, TrkB, was not altered by E2 or T. E2 (but not T) significantly increased intracellular cyclic AMP levels. Notably, Epac1 and Epac2 expression were significantly reduced by E2 and T. Furthermore, SNARE complex protein SNAP25 was decreased. Overall, these novel data suggest that physiologically relevant concentrations of E2 or T inhibit BDNF secretion in human ASM, suggesting a potential interaction of sex steroids with BDNF in the airway that is different from brain. The relevance of sex steroid-BDNF interactions may lie in their overall contribution to airway diseases such as asthma. J. Cell. Physiol. 231: 1586-1592, 2016. © 2015 Wiley Periodicals, Inc. PMID:26566264

  4. Inflammatory responses of airway smooth muscle cells and effects of endothelin receptor antagonism.

    PubMed

    Knobloch, Jürgen; Lin, Yingfeng; Konradi, Jürgen; Jungck, David; Behr, Juergen; Strauch, Justus; Stoelben, Erich; Koch, Andrea

    2013-07-01

    Endothelin receptor antagonists (ETRAs), authorized for pulmonary hypertension, have failed to prove their utility in chronic lung diseases with corticosteroid-resistant airway inflammation when applied at late disease stages with emphysema/fibrosis. Earlier administration might prove effective by targeting the interaction between airway inflammation and tissue remodeling. We hypothesized that human airway smooth muscle cells (HASMCs) participate in linking inflammation with remodeling and that associated genes become differentially suppressed by ambrisentan (A-receptor selective ETRA) and bosentan (nonselective/dual ETRA). Inflammatory responses of ex vivo-cultivated HASMCs to TNF-α were investigated by whole-genome microarray analyses. qRT-PCR and ELISA were used to test inflammatory and remodeling genes for sensitivity to bosentan and ambrisentan and to investigate differential sensitivities mechanistically. ETRA and corticosteroid effects were compared in HASMCs from patients with chronic obstructive pulmonary disease. TNF-α induced the expression of 18 cytokines/chemokines and five tissue remodeling genes involved in severe, corticosteroid-insensitive asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and/or pulmonary hypertension. Thirteen cytokines/chemokines, MMP13, and WISP1 were suppressed by ETRAs. Eight genes had differential sensitivity to bosentan and ambrisentan depending on the endothelin-B receptor impact on transcriptional regulation and mRNA stabilization. Chemokine (C-C motif) ligands 2 and 5, granulocyte macrophage colony-stimulating factor, and MMP13 had increased sensitivity to bosentan or bosentan/dexamethasone combination versus dexamethasone alone. Suppression of cytokine and remodeling gene expression by ETRAs was confirmed in TNF-α-activated human bronchial epithelial cells. HASMCs and human bronchial epithelial cells participate in the interaction of inflammation and tissue remodeling. This interaction is

  5. The effects of in utero vitamin D deficiency on airway smooth muscle mass and lung function.

    PubMed

    Foong, Rachel E; Bosco, Anthony; Jones, Anya C; Gout, Alex; Gorman, Shelley; Hart, Prue H; Zosky, Graeme R

    2015-11-01

    We have previously demonstrated increased airway smooth muscle (ASM) mass and airway hyperresponsiveness in whole-life vitamin D-deficient female mice. In this study, we aimed to uncover the molecular mechanisms contributing to altered lung structure and function. RNA was extracted from lung tissue of whole-life vitamin D-deficient and -replete female mice, and gene expression patterns were profiled by RNA sequencing. The data showed that genes involved in embryonic organ development, pattern formation, branching morphogenesis, Wingless/Int signaling, and inflammation were differentially expressed in vitamin D-deficient mice. Network analysis suggested that differentially expressed genes were connected by the hubs matrix metallopeptidase 9; NF-κ light polypeptide gene enhancer in B cells inhibitor, α; epidermal growth factor receptor; and E1A binding protein p300. Given our findings that developmental pathways may be altered, we investigated if the timing of vitamin D exposure (in utero vs. postnatal) had an impact on lung health outcomes. Gene expression was measured in in utero or postnatal vitamin D-deficient mice, as well as whole-life vitamin D-deficient and -replete mice at 8 weeks of age. Baseline lung function, airway hyperresponsiveness, and airway inflammation were measured and lungs fixed for lung structure assessment using stereological methods and quantification of ASM mass. In utero vitamin D deficiency was sufficient to increase ASM mass and baseline airway resistance and alter lung structure. There were increased neutrophils but decreased lymphocytes in bronchoalveolar lavage. Expression of inflammatory molecules S100A9 and S100A8 was mainly increased in postnatal vitamin D-deficient mice. These observations suggest that in utero vitamin D deficiency can alter lung structure and function and increase inflammation, contributing to symptoms in chronic diseases, such as asthma. PMID:25867172

  6. Antimitogenic effect of bitter taste receptor agonists on airway smooth muscle cells.

    PubMed

    Sharma, Pawan; Panebra, Alfredo; Pera, Tonio; Tiegs, Brian C; Hershfeld, Alena; Kenyon, Lawrence C; Deshpande, Deepak A

    2016-02-15

    Airway remodeling is a hallmark feature of asthma and chronic obstructive pulmonary disease. Clinical studies and animal models have demonstrated increased airway smooth muscle (ASM) mass, and ASM thickness is correlated with severity of the disease. Current medications control inflammation and reverse airway obstruction effectively but have limited effect on remodeling. Recently we identified the expression of bitter taste receptors (TAS2R) on ASM cells, and activation with known TAS2R agonists resulted in ASM relaxation and bronchodilation. These studies suggest that TAS2R can be used as new therapeutic targets in the treatment of obstructive lung diseases. To further establish their effectiveness, in this study we aimed to determine the effects of TAS2R agonists on ASM growth and promitogenic signaling. Pretreatment of healthy and asthmatic human ASM cells with TAS2R agonists resulted in a dose-dependent inhibition of ASM proliferation. The antimitogenic effect of TAS2R ligands was not dependent on activation of protein kinase A, protein kinase C, or high/intermediate-conductance calcium-activated K(+) channels. Immunoblot analyses revealed that TAS2R agonists inhibit growth factor-activated protein kinase B phosphorylation without affecting the availability of phosphatidylinositol 3,4,5-trisphosphate, suggesting TAS2R agonists block signaling downstream of phosphatidylinositol 3-kinase. Furthermore, the antimitogenic effect of TAS2R agonists involved inhibition of induced transcription factors (activator protein-1, signal transducer and activator of transcription-3, E2 factor, nuclear factor of activated T cells) and inhibition of expression of multiple cell cycle regulatory genes, suggesting a direct inhibition of cell cycle progression. Collectively, these findings establish the antimitogenic effect of TAS2R agonists and identify a novel class of receptors and signaling pathways that can be targeted to reduce or prevent airway remodeling as well as

  7. Ovalbumin sensitization of guinea pig at birth prevents the ontogenetic decrease in airway smooth muscle responsiveness

    PubMed Central

    Chitano, Pasquale; Wang, Lu; Degan, Simone; Worthington, Charles L.; Pozzato, Valeria; Hussaini, Syed H.; Turner, Wesley C.; Dorscheid, Delbert R.; Murphy, Thomas M.

    2014-01-01

    Abstract Airway smooth muscle (ASM) displays a hyperresponsive phenotype at young age and becomes less responsive in adulthood. We hypothesized that allergic sensitization, which causes ASM hyperresponsiveness and typically occurs early in life, prevents the ontogenetic loss of the ASM hyperresponsive phenotype. We therefore studied whether neonatal allergic sensitization, not followed by later allergen challenges, alters the ontogenesis of ASM properties. We neonatally sensitized guinea pigs to ovalbumin and studied them at 1 week, 3 weeks, and 3 months (adult). A Schultz‐Dale response in isolated tracheal rings confirmed sensitization. The occurrence of inflammation was evaluated in the blood and in the submucosa of large airways. We assessed ASM function in tracheal strips as ability to produce force and shortening. ASM content of vimentin was also studied. A Schultz‐Dale response was observed in all 3‐week or older sensitized animals. A mild inflammatory process was characterized by eosinophilia in the blood and in the airway submucosa. Early life sensitization had no effect on ASM force generation, but prevented the ontogenetic decline of shortening velocity and the increase in resistance to shortening. Vimentin increased with age in control but not in sensitized animals. Allergic sensitization at birth without subsequent allergen exposures is sufficient to prevent normal ASM ontogenesis, inducing persistence to adulthood of an ASM hyperresponsive phenotype. PMID:25501429

  8. Studying airway smooth muscle in vivo with PS-OCT (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Adams, David C.; Hariri, Lida P.; Miller, Alyssa J.; Villiger, Martin; Holz, Jasmin; Szabari, Margit V.; Bouma, Brett E.; Luster, Andrew D.; Medoff, Benjamin D.; Suter, Melissa J.

    2016-03-01

    Present understanding of the pathophysiological mechanisms of asthma has been severely limited by the lack of an imaging modality capable of assessing airway conditions of asthma patients in vivo. Of particular interest is the role that airway smooth muscle (ASM) plays in the development of asthma and asthma related symptoms. We have developed novel techniques that we applied to Polarization Sensitive OCT (PS-OCT) in order to assess ASM, and validated our results with a substantial number of histological matches. In this work we employ our system in the study of ASM distributions in both asthmatic and non-asthmatic airways with data obtained in vivo from human volunteers. By isolating the ASM and performing volumetric analysis we obtain a variety of informative metrics such as ASM thickness and band width, and compare these quantities between subject types. Furthermore, we demonstrate that the degree of birefringence of the ASM can be associated with contractility, allowing us to estimate pressure exerted by ASM during contraction. We apply this technique to in vivo datasets from human volunteers as well.

  9. Cigarette smoke-induced mitochondrial fragmentation and dysfunction in human airway smooth muscle

    PubMed Central

    Aravamudan, Bharathi; Kiel, Alexander; Freeman, Michelle; Delmotte, Philippe; Thompson, Michael; Vassallo, Robert; Sieck, Gary C.; Pabelick, Christina M.

    2014-01-01

    The balance between mitochondrial fission and fusion is crucial for mitochondria to perform its normal cellular functions. We hypothesized that cigarette smoke (CS) disrupts this balance and enhances mitochondrial dysfunction in the airway. In nonasthmatic human airway smooth muscle (ASM) cells, CS extract (CSE) induced mitochondrial fragmentation and damages their networked morphology in a concentration-dependent fashion, via increased expression of mitochondrial fission protein dynamin-related protein 1 (Drp1) and decreased fusion protein mitofusin (Mfn) 2. CSE effects on Drp1 vs. Mfn2 and mitochondrial network morphology involved reactive oxygen species (ROS), activation of extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt), protein kinase C (PKC) and proteasome pathways, as well as transcriptional regulation via factors such as NF-κB and nuclear erythroid 2-related factor 2. Inhibiting Drp1 prevented CSE effects on mitochondrial networks and ROS generation, whereas blocking Mfn2 had the opposite, detrimental effect. In ASM from asmatic patients, mitochondria exhibited substantial morphological defects at baseline and showed increased Drp1 but decreased Mfn2 expression, with exacerbating effects of CSE. Overall, these results highlight the importance of mitochondrial networks and their regulation in the context of cellular changes induced by insults such as inflammation (as in asthma) or CS. Altered mitochondrial fission/fusion proteins have a further potential to influence parameters such as ROS and cell proliferation and apoptosis relevant to airway diseases. PMID:24610934

  10. Effects of miRNA-145 on airway smooth muscle cells function.

    PubMed

    Liu, Yun; Sun, Xiuzhen; Wu, Yuanyuan; Fang, Ping; Shi, Hongyang; Xu, Jing; Li, Manxiang

    2015-11-01

    The pathological changes of airway smooth muscle (ASM) contribute to airway remodeling during asthma. Here, we investigated the effect of miR-145 on ASM function. We found that miR-145 was aberrantly more highly expressed in ASM cells exposed to cytokine stimulation that mimic the airway conditions of patients with asthma. Repression of miR-145 resulted in decreased ASM cell proliferation and migration in a dose-dependent manner and down-regulation of type I collagen and contractile protein MHC in ASM cells. qRT-PCR and Western blot analysis demonstrated that miR-145 negatively regulated the expression of downstream target Krüppel-like factor 4 (KLF4) protein, and overexpression of KLF4 attenuated the effects of miR-145 on ASM cells. Further studies showed that KLF4 significantly up-regulated the expression of p21 and down-regulated matrix metalloproteinase (MMP-2 and MMP-9). In conclusion, miR-145 overexpression in ASM cells significantly inhibited KLF4, and subsequently affected downstream p21, MMP-2, and MMP-9 expressions, eventually leading to enhanced proliferation and migration of ASM cells in vitro. PMID:26197891

  11. Relaxant Action of Plumula Nelumbinis Extract on Mouse Airway Smooth Muscle

    PubMed Central

    Tan, Li; Chen, Weiwei; Wei, Ming-Yu; Shen, Jinhua; Yu, Meng-Fei; Yang, Guangzhong; Guo, Donglin; Qin, Gangjian; Ji, Guangju; Liu, Qing-Hua

    2015-01-01

    The traditional herb Plumula Nelumbinis is widely used in the world because it has many biological activities, such as anti-inflammation, antioxidant, antihypertension, and butyrylcholinesterase inhibition. However, the action of Plumula Nelumbinis on airway smooth muscle (ASM) relaxation has not been investigated. A chloroform extract of Plumula Nelumbinis (CEPN) was prepared, which completely inhibited precontraction induced by high K+ in a concentration-dependent manner in mouse tracheal rings, but it had no effect on resting tension. CEPN also blocked voltage-dependent L-type Ca2+ channel- (VDCC-) mediated currents. In addition, ACh-induced precontraction was also completely blocked by CEPN and partially inhibited by nifedipine or pyrazole 3. Besides, CEPN partially reduced ACh-activated nonselective cation channel (NSCC) currents. Taken together, our data demonstrate that CEPN blocked VDCC and NSCC to inhibit Ca2+ influx, resulting in relaxation of precontracted ASM. This finding indicates that CEPN would be a candidate of new potent bronchodilators. PMID:25763092

  12. Human airway smooth muscle maintain in situ cell orientation and phenotype when cultured on aligned electrospun scaffolds

    PubMed Central

    Morris, G. E.; Bridge, J. C.; Eltboli, O. M. I.; Lewis, M. P.; Knox, A. J.; Aylott, J. W.; Brightling, C. E.; Ghaemmaghami, A. M.

    2014-01-01

    Human airway smooth muscle (HASM) contraction plays a central role in regulating airway resistance in both healthy and asthmatic bronchioles. In vitro studies that investigate the intricate mechanisms that regulate this contractile process are predominantly conducted on tissue culture plastic, a rigid, 2D geometry, unlike the 3D microenvironment smooth muscle cells are exposed to in situ. It is increasingly apparent that cellular characteristics and responses are altered between cells cultured on 2D substrates compared with 3D topographies. Electrospinning is an attractive method to produce 3D topographies for cell culturing as the fibers produced have dimensions within the nanometer range, similar to cells' natural environment. We have developed an electrospun scaffold using the nondegradable, nontoxic, polymer polyethylene terephthalate (PET) composed of uniaxially orientated nanofibers and have evaluated this topography's effect on HASM cell adhesion, alignment, and morphology. The fibers orientation provided contact guidance enabling the formation of fully aligned sheets of smooth muscle. Moreover, smooth muscle cells cultured on the scaffold present an elongated cell phenotype with altered contractile protein levels and distribution. HASM cells cultured on this scaffold responded to the bronchoconstrictor bradykinin. The platform presented provides a novel in vitro model that promotes airway smooth muscle cell development toward a more in vivo-like phenotype while providing topological cues to ensure full cell alignment. PMID:24793171

  13. Role of Dystrophin in Airway Smooth Muscle Phenotype, Contraction and Lung Function

    PubMed Central

    Sharma, Pawan; Basu, Sujata; Mitchell, Richard W.; Stelmack, Gerald L.; Anderson, Judy E.; Halayko, Andrew J.

    2014-01-01

    Dystrophin links the transmembrane dystrophin-glycoprotein complex to the actin cytoskeleton. We have shown that dystrophin-glycoprotein complex subunits are markers for airway smooth muscle phenotype maturation and together with caveolin-1, play an important role in calcium homeostasis. We tested if dystrophin affects phenotype maturation, tracheal contraction and lung physiology. We used dystrophin deficient Golden Retriever dogs (GRMD) and mdx mice vs healthy control animals in our approach. We found significant reduction of contractile protein markers: smooth muscle myosin heavy chain (smMHC) and calponin and reduced Ca2+ response to contractile agonist in dystrophin deficient cells. Immunocytochemistry revealed reduced stress fibers and number of smMHC positive cells in dystrophin-deficient cells, when compared to control. Immunoblot analysis of Akt1, GSK3β and mTOR phosphorylation further revealed that downstream PI3K signaling, which is essential for phenotype maturation, was suppressed in dystrophin deficient cell cultures. Tracheal rings from mdx mice showed significant reduction in the isometric contraction to methacholine (MCh) when compared to genetic control BL10ScSnJ mice (wild-type). In vivo lung function studies using a small animal ventilator revealed a significant reduction in peak airway resistance induced by maximum concentrations of inhaled MCh in mdx mice, while there was no change in other lung function parameters. These data show that the lack of dystrophin is associated with a concomitant suppression of ASM cell phenotype maturation in vitro, ASM contraction ex vivo and lung function in vivo, indicating that a linkage between the DGC and the actin cytoskeleton via dystrophin is a determinant of the phenotype and functional properties of ASM. PMID:25054970

  14. Biomechanical effects of environmental and engineered particles on human airway smooth muscle cells

    PubMed Central

    Berntsen, P.; Park, C. Y.; Rothen-Rutishauser, B.; Tsuda, A.; Sager, T. M.; Molina, R. M.; Donaghey, T. C.; Alencar, A. M.; Kasahara, D. I.; Ericsson, T.; Millet, E. J.; Swenson, J.; Tschumperlin, D. J.; Butler, J. P.; Brain, J. D.; Fredberg, J. J.; Gehr, P.; Zhou, E. H.

    2010-01-01

    The past decade has seen significant increases in combustion-generated ambient particles, which contain a nanosized fraction (less than 100 nm), and even greater increases have occurred in engineered nanoparticles (NPs) propelled by the booming nanotechnology industry. Although inhalation of these particulates has become a public health concern, human health effects and mechanisms of action for NPs are not well understood. Focusing on the human airway smooth muscle cell, here we show that the cellular mechanical function is altered by particulate exposure in a manner that is dependent upon particle material, size and dose. We used Alamar Blue assay to measure cell viability and optical magnetic twisting cytometry to measure cell stiffness and agonist-induced contractility. The eight particle species fell into four categories, based on their respective effect on cell viability and on mechanical function. Cell viability was impaired and cell contractility was decreased by (i) zinc oxide (40–100 nm and less than 44 μm) and copper(II) oxide (less than 50 nm); cell contractility was decreased by (ii) fluorescent polystyrene spheres (40 nm), increased by (iii) welding fumes and unchanged by (iv) diesel exhaust particles, titanium dioxide (25 nm) and copper(II) oxide (less than 5 μm), although in none of these cases was cell viability impaired. Treatment with hydrogen peroxide up to 500 μM did not alter viability or cell mechanics, suggesting that the particle effects are unlikely to be mediated by particle-generated reactive oxygen species. Our results highlight the susceptibility of cellular mechanical function to particulate exposures and suggest that direct exposure of the airway smooth muscle cells to particulates may initiate or aggravate respiratory diseases. PMID:20356875

  15. Effect of different bronchodilators on airway smooth muscle responsiveness to contractile agents.

    PubMed

    Gustafsson, B; Persson, C G

    1991-05-01

    "Functional antagonism" is often used to describe the general relaxant effect of beta 2 agonists and xanthines and their ability to protect the airways against bronchoconstrictor stimuli. This study in guinea pig isolated trachea addresses the question of whether the capacity of these drugs to protect against constrictor stimuli is related to smooth muscle relaxation. Three antimuscarinic drugs were also examined to determine whether antagonism of mediators other than muscarinic agonists might contribute to bronchodilatation by these antimuscarinic drugs. Terbutaline (1.1 x 10(-7), 2.2 x 10(-7) M), theophylline (2.2 x 10(-4), 4.4 x 10(-4) M), and enprofylline (5.2 x 10(-5), 1.0 x 10(-4) M) relaxed the tracheal tension that remained after indomethacin treatment. They did not, however, alter the carbachol concentration-response curve significantly. In addition, neither theophylline (2.2 x 10(-4) M) nor terbutaline (1.1 x 10(-7) M) altered histamine induced contraction. Atropine sulphate, glycopyrrolate, and ipratropium bromide had EC50 values of 10(-9) - 10(-8) M for relaxation of carbachol induced contractions, whereas concentrations of 10(-6) - 10(-3) M or greater were required to relax contractions induced by allergen and nine other non-muscarinic mediators. It is suggested that bronchodilatation by antimuscarinic drugs in vivo is due to inhibition of acetylcholine induced bronchoconstriction alone and that beta 2 agonists and xanthines have poor ability to protect airway smooth muscle against constrictor stimuli. Hence mechanisms other than bronchodilatation and "functional antagonism" should be considered to explain the protection against constrictor stimuli in asthma seen with beta 2 agonists and xanthines. PMID:2068693

  16. Diacylglycerol-containing docosahexaenoic acid in acyl chain modulates airway smooth muscle tone.

    PubMed

    Hichami, Aziz; Morin, Caroline; Rousseau, Eric; Khan, Naim A

    2005-10-01

    We synthesized and assessed the role of a diacylglycerol (DAG)-containing docosahexaenoic acid (DHA), that is, 1-stearoyl-2-docosahexaenoyl-sn-glycerol (SDHG), in the contraction of guinea pig airway smooth muscle (ASM). We compared its action with 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG) and 1,2-dioctanoyl-sn-glycerol (1,2-DiC8), a stable DAG analog. The three DAGs (SAG, SDHG, and 1,2-DiC8) induced reversible concentration-dependent contraction of ASM. SDHG induced higher guinea pig ASM contraction than did SAG and 1,2-DiC8. The effects of SDHG were blocked, to different extents, by nifedipine (L-type Ca2+ channel blocker). By employing GF-109203X (protein kinase C [PKC] inhibitor) and lanthanum (La3+), a nonselective cation channel blocker, we observed that SDHG evoked ASM contractile response via PKC-dependent and PKC-independent (but Ca2+-dependent) pathways. Interestingly, SAG exerted its action only by increasing [Ca2+]i and did not require PKC activation. To probe the implication of calcium mobilization, we employed thapsigargin (TG), which also induced ASM contraction in a calcium-dependent manner. SDHG and 1,2-DiC8, in a PKC-dependent manner, induced the phosphorylation of CPI-17 (myosin light chain phosphatase inhibitor of 17 kD). Furthermore, SAG and TG failed to phosphorylate CPI-17 in ASM cells. Our results suggest that different DAG species, produced during a dietary supplementation with fatty acids, could modulate the reactivity of airway smooth muscles in a PKC-dependent and -independent manner, and hence, may play a critical role in health and disease. PMID:15961724

  17. IL-9-mediated induction of eotaxin1/CCL11 in human airway smooth muscle cells.

    PubMed

    Gounni, Abdelilah Soussi; Hamid, Qutayba; Rahman, Sahidur M; Hoeck, Jutta; Yang, Jie; Shan, Lianyu

    2004-08-15

    Recent work has shown the potential importance of IL-9 in allergic diseases. The development of transgenic mice overexpressing IL-9 has suggested a key role for this cytokine in the development of the asthmatic phenotype including airway eosinophilia. In this study, we evaluated the expression of the IL-9R and the effects of IL-9 on human ASM cells by examining the release of Th2-associated chemokines (eotaxin1/CCL11 and thymus- and activation-regulated chemokine (TARC)/CCL17). IL-9R alpha-chain mRNA and surface expression were detected in cultured human airway smooth muscle (ASM) cells. In addition, primary cultured ASM cells, as well as bronchial smooth muscle cells within biopsies of asthmatics and not control subjects, revealed IL-9R protein expression. IL-9 stimulation of human ASM cells resulted in release of eotaxin1/CCL11, but had no effect on the release of TARC/CCL17, in time- and dose-dependent manner. Moreover, in vitro chemotaxis assay demonstrated that conditioned medium from IL-9-stimulated ASM cells attracted human eosinophils. Neutralizing Abs to IL-9, but not to IL-4 or IL-13, reduced significantly IL-9-induced production of eotaxin1/CCL11 from ASM cells. Interestingly, real-time RT-PCR showed that IL-9 up-regulated eotaxin1/CCL11 mRNA expression, but had no effect on TARC/CCL17. Treatment with Act D abrogates IL-9-induced eotaxin1/CCL11 mRNA and protein release by ASM cells. Finally, transfection study using eotaxin1/CCL11 promoter luciferase construct confirmed that IL-9 induced eotaxin1/CCL11 at the transcriptional level. Taken together, these data provide new evidence demonstrating that IL-9-dependent activation of ASM cells contributes to eosinophilic inflammation observed in asthma. PMID:15294996

  18. Biomechanical effects of environmental and engineered particles on human airway smooth muscle cells.

    PubMed

    Berntsen, P; Park, C Y; Rothen-Rutishauser, B; Tsuda, A; Sager, T M; Molina, R M; Donaghey, T C; Alencar, A M; Kasahara, D I; Ericsson, T; Millet, E J; Swenson, J; Tschumperlin, D J; Butler, J P; Brain, J D; Fredberg, J J; Gehr, P; Zhou, E H

    2010-06-01

    The past decade has seen significant increases in combustion-generated ambient particles, which contain a nanosized fraction (less than 100 nm), and even greater increases have occurred in engineered nanoparticles (NPs) propelled by the booming nanotechnology industry. Although inhalation of these particulates has become a public health concern, human health effects and mechanisms of action for NPs are not well understood. Focusing on the human airway smooth muscle cell, here we show that the cellular mechanical function is altered by particulate exposure in a manner that is dependent upon particle material, size and dose. We used Alamar Blue assay to measure cell viability and optical magnetic twisting cytometry to measure cell stiffness and agonist-induced contractility. The eight particle species fell into four categories, based on their respective effect on cell viability and on mechanical function. Cell viability was impaired and cell contractility was decreased by (i) zinc oxide (40-100 nm and less than 44 microm) and copper(II) oxide (less than 50 nm); cell contractility was decreased by (ii) fluorescent polystyrene spheres (40 nm), increased by (iii) welding fumes and unchanged by (iv) diesel exhaust particles, titanium dioxide (25 nm) and copper(II) oxide (less than 5 microm), although in none of these cases was cell viability impaired. Treatment with hydrogen peroxide up to 500 microM did not alter viability or cell mechanics, suggesting that the particle effects are unlikely to be mediated by particle-generated reactive oxygen species. Our results highlight the susceptibility of cellular mechanical function to particulate exposures and suggest that direct exposure of the airway smooth muscle cells to particulates may initiate or aggravate respiratory diseases. PMID:20356875

  19. Human airway smooth muscle cells secrete amphiregulin via bradykinin/COX-2/PGE2, inducing COX-2, CXCL8, and VEGF expression in airway epithelial cells

    PubMed Central

    Knox, Alan J.

    2015-01-01

    Human airway smooth muscle cells (HASMC) contribute to asthma pathophysiology through an increased smooth muscle mass and elevated cytokine/chemokine output. Little is known about how HASMC and the airway epithelium interact to regulate chronic airway inflammation and remodeling. Amphiregulin is a member of the family of epidermal growth factor receptor (EGFR) agonists with cell growth and proinflammatory roles and increased expression in the lungs of asthma patients. Here we show that bradykinin (BK) stimulation of HASMC increases amphiregulin secretion in a mechanism dependent on BK-induced COX-2 expression, increased PGE2 output, and the stimulation of HASMC EP2 and EP4 receptors. Conditioned medium from BK treated HASMC induced CXCL8, VEGF, and COX-2 mRNA and protein accumulation in airway epithelial cells, which were blocked by anti-amphiregulin antibodies and amphiregulin siRNA, suggesting a paracrine effect of HASMC-derived amphiregulin on airway epithelial cells. Consistent with this, recombinant amphiregulin induced CXCL8, VEGF, and COX-2 in airway epithelial cells. Finally, we found that conditioned media from amphiregulin-stimulated airway epithelial cells induced amphiregulin expression in HASMC and that this was dependent on airway epithelial cell COX-2 activity. Our study provides evidence of a dynamic axis of interaction between HASMC and epithelial cells that amplifies CXCL8, VEGF, COX-2, and amphiregulin production. PMID:26047642

  20. Effects of cigarette smoke extract on human airway smooth muscle cells in COPD.

    PubMed

    Chen, Ling; Ge, Qi; Tjin, Gavin; Alkhouri, Hatem; Deng, Linghong; Brandsma, Corry-Anke; Adcock, Ian; Timens, Wim; Postma, Dirkje; Burgess, Janette K; Black, Judith L; Oliver, Brian G G

    2014-09-01

    We hypothesised that the response to cigarette smoke in airway smooth muscle (ASM) cells from smokers with chronic obstructive pulmonary disease (COPD) would be intrinsically different from smokers without COPD, producing greater pro-inflammatory mediators and factors relating to airway remodelling. ASM cells were obtained from smokers with or without COPD, and then stimulated with cigarette smoke extract (CSE) or transforming growth factor-β1. The production of chemokines and matrix metalloproteinases (MMPs) were measured by ELISA, and the deposition of collagens by extracellular matrix ELISA. The effects of CSE on cell attachment and wound healing were measured by toluidine blue attachment and cell tracker green wound healing assays. CSE increased the release of CXCL8 and CXCL1 from human ASM cells, and cells from smokers with COPD produced more CSE-induced CXCL1. The production of MMP-1, -3 and -10, and the deposition of collagen VIII alpha 1 (COL8A1) were increased by CSE, especially in the COPD group which had higher production of MMP-1 and deposition of COL8A1. CSE decreased ASM cell attachment and wound healing in the COPD group only. ASM cells from smokers with COPD were more sensitive to CSE stimulation, which may explain, in part, why some smokers develop COPD. PMID:24969654

  1. Baicalin inhibits PDGF-induced proliferation and migration of airway smooth muscle cells

    PubMed Central

    Yang, Guang; Li, Jian-Qiang; Bo, Jian-Ping; Wang, Bei; Tian, Xin-Rui; Liu, Tan-Zhen; Liu, Zhuo-La

    2015-01-01

    Airway smooth muscle (ASM) cell proliferation and migration play important roles in airway remodeling in asthma. In vitro platelet-derived growth factor (PDGF) induced ASM cell proliferation and migration. Baicalin is one of flavonoid extracts from Scutellaria baicalensis, which has an anti-asthma effect. However, little is known about its role in PDGF-induced proliferation and migration in rat ASM (RASM) cells. In this study, we aimed to investigate the effects of baicalin on PDGF-induced RASM cell proliferation and migration. We also identified the signaling pathway by which baicalin influences RASM cell proliferation and migration. In the current study, we demonstrated that baicalin suppressed PDGF-induced RASM cell proliferation, arrested PDGF-induced cell-cycle progression. It also suppressed PDGF-induced RASM cell migration. Furthermore, baicalin suppressed PDGF-induced expression of phosphorylated p38, ERK1/2 and JNK in RASM cells. In summary, our study is the first to show that baicalin pretreatment can significantly inhibit PDGF-induced RASM cell proliferation and migration by suppressing the MAPK signaling pathway, and baicalin may be a useful chemotherapeutic agent for asthma. PMID:26884970

  2. Olfactory Receptors Modulate Physiological Processes in Human Airway Smooth Muscle Cells.

    PubMed

    Kalbe, Benjamin; Knobloch, Jürgen; Schulz, Viola M; Wecker, Christine; Schlimm, Marian; Scholz, Paul; Jansen, Fabian; Stoelben, Erich; Philippou, Stathis; Hecker, Erich; Lübbert, Hermann; Koch, Andrea; Hatt, Hanns; Osterloh, Sabrina

    2016-01-01

    Pathophysiological mechanisms in human airway smooth muscle cells (HASMCs) significantly contribute to the progression of chronic inflammatory airway diseases with limited therapeutic options, such as severe asthma and COPD. These abnormalities include the contractility and hyperproduction of inflammatory proteins. To develop therapeutic strategies, key pathological mechanisms, and putative clinical targets need to be identified. In the present study, we demonstrated that the human olfactory receptors (ORs) OR1D2 and OR2AG1 are expressed at the RNA and protein levels in HASMCs. Using fluorometric calcium imaging, specific agonists for OR2AG1 and OR1D2 were identified to trigger transient Ca(2+) increases in HASMCs via a cAMP-dependent signal transduction cascade. Furthermore, the activation of OR2AG1 via amyl butyrate inhibited the histamine-induced contraction of HASMCs, whereas the stimulation of OR1D2 with bourgeonal led to an increase in cell contractility. In addition, OR1D2 activation induced the secretion of IL-8 and GM-CSF. Both effects were inhibited by the specific OR1D2 antagonist undecanal. We herein provide the first evidence to show that ORs are functionally expressed in HASMCs and regulate pathophysiological processes. Therefore, ORs might be new therapeutic targets for these diseases, and blocking ORs could be an auspicious strategy for the treatment of early-stage chronic inflammatory lung diseases. PMID:27540365

  3. Olfactory Receptors Modulate Physiological Processes in Human Airway Smooth Muscle Cells

    PubMed Central

    Kalbe, Benjamin; Knobloch, Jürgen; Schulz, Viola M.; Wecker, Christine; Schlimm, Marian; Scholz, Paul; Jansen, Fabian; Stoelben, Erich; Philippou, Stathis; Hecker, Erich; Lübbert, Hermann; Koch, Andrea; Hatt, Hanns; Osterloh, Sabrina

    2016-01-01

    Pathophysiological mechanisms in human airway smooth muscle cells (HASMCs) significantly contribute to the progression of chronic inflammatory airway diseases with limited therapeutic options, such as severe asthma and COPD. These abnormalities include the contractility and hyperproduction of inflammatory proteins. To develop therapeutic strategies, key pathological mechanisms, and putative clinical targets need to be identified. In the present study, we demonstrated that the human olfactory receptors (ORs) OR1D2 and OR2AG1 are expressed at the RNA and protein levels in HASMCs. Using fluorometric calcium imaging, specific agonists for OR2AG1 and OR1D2 were identified to trigger transient Ca2+ increases in HASMCs via a cAMP-dependent signal transduction cascade. Furthermore, the activation of OR2AG1 via amyl butyrate inhibited the histamine-induced contraction of HASMCs, whereas the stimulation of OR1D2 with bourgeonal led to an increase in cell contractility. In addition, OR1D2 activation induced the secretion of IL-8 and GM-CSF. Both effects were inhibited by the specific OR1D2 antagonist undecanal. We herein provide the first evidence to show that ORs are functionally expressed in HASMCs and regulate pathophysiological processes. Therefore, ORs might be new therapeutic targets for these diseases, and blocking ORs could be an auspicious strategy for the treatment of early-stage chronic inflammatory lung diseases. PMID:27540365

  4. Prostaglandin E2 induces expression of MAPK phosphatase 1 (MKP-1) in airway smooth muscle cells.

    PubMed

    Rumzhum, Nowshin N; Ammit, Alaina J

    2016-07-01

    Prostaglandin E2 (PGE2) is a prostanoid with diverse actions in health and disease. In chronic respiratory diseases driven by inflammation, PGE2 has both positive and negative effects. An enhanced understanding of the receptor-mediated cellular signalling pathways induced by PGE2 may help us separate the beneficial properties from unwanted actions of this important prostaglandin. PGE2 is known to exert anti-inflammatory and bronchoprotective actions in human airways. To date however, whether PGE2 increases production of the anti-inflammatory protein MAPK phosphatase 1 (MKP-1) was unknown. We address this herein and use primary cultures of human airway smooth muscle (ASM) cells to show that PGE2 increases MKP-1 mRNA and protein upregulation in a concentration-dependent manner. We explore the signalling pathways responsible and show that PGE2-induces CREB phosphorylation, not p38 MAPK activation, in ASM cells. Moreover, we utilize selective antagonists of EP2 (PF-04418948) and EP4 receptors (GW 627368X) to begin to identify EP-mediated functional outcomes in ASM cells in vitro. Taken together with earlier studies, our data suggest that PGE2 increases production of the anti-inflammatory protein MKP-1 via cAMP/CREB-mediated cellular signalling in ASM cells and demonstrates that EP2 may, in part, be involved. PMID:27108790

  5. Hyaluronic acid influence on platelet-induced airway smooth muscle cell proliferation

    SciTech Connect

    Svensson Holm, Ann-Charlotte B.; Bengtsson, Torbjoern; Grenegard, Magnus; Lindstroem, Eva G.

    2012-03-10

    Hyaluronic acid (HA) is one of the main components of the extracellular matrix (ECM) and is expressed throughout the body including the lung and mostly in areas surrounding proliferating and migrating cells. Furthermore, platelets have been implicated as important players in the airway remodelling process, e.g. due to their ability to induce airway smooth muscle cell (ASMC) proliferation. The aim of the present study was to investigate the role of HA, the HA-binding surface receptor CD44 and focal adhesion kinase (FAK) in platelet-induced ASMC proliferation. Proliferation of ASMC was measured using the MTS-assay, and we found that the CD44 blocking antibody and the HA synthase inhibitor 4-Methylumbelliferone (4-MU) significantly inhibited platelet-induced ASMC proliferation. The interaction between ASMC and platelets was studied by fluorescent staining of F-actin. In addition, the ability of ASMC to synthesise HA was investigated by fluorescent staining using biotinylated HA-binding protein and a streptavidin conjugate. We observed that ASMC produced HA and that a CD44 blocking antibody and 4-MU significantly inhibited platelet binding to the area surrounding the ASMC. Furthermore, the FAK-inhibitor PF 573228 inhibited platelet-induced ASMC proliferation. Co-culture of ASMC and platelets also resulted in increased phosphorylation of FAK as detected by Western blot analysis. In addition, 4-MU significantly inhibited the increased FAK-phosphorylation. In conclusion, our findings demonstrate that ECM has the ability to influence platelet-induced ASMC proliferation. Specifically, we propose that HA produced by ASMC is recognised by platelet CD44. The platelet/HA interaction is followed by FAK activation and increased proliferation of co-cultured ASMC. We also suggest that the mitogenic effect of platelets represents a potential important and novel mechanism that may contribute to airway remodelling.

  6. Three Paradigms of Airway Smooth Muscle Hyperresponsiveness in Young Guinea Pigs

    PubMed Central

    Chitano, Pasquale; Wang, Lu; Murphy, Thomas M.

    2008-01-01

    Evidence for contributions of airway smooth muscle (ASM) to the hyperresponsiveness of newborn and juvenile airways continues to accumulate. In our laboratory three novel paradigms of hyperresponsiveness of newborn and young ASM have recently emerged using a guinea pig model of maturation in three age groups-- 1 week (newborn); 3 week (juvenile) and 2−3 months (adult). These include 1) evidence for a natural decline after newborn and juvenile life of the shortening velocity of ASM shortening associated with a decrease in regulatory myosin light chain (MLC) phosphorylation and a parallel decline in the content of MLC kinase. Associated with the decrease in ASM shortening with age is an increase in the internal resistance to shortening. This relationship can be approximated as dP/dtmax ≈ dP/dLpassive × dL/dtmax (the maximal rate of increase of active stress generation ≈ the passive stiffness × the maximal shortening velocity V0). 2) The second paradigm demonstrates that newborn ASM, unlike that in adults, does not relax with prolonged electrical field stimulation. The impaired relaxation is related to changes in prostaglandin synthesis and acetylcholinesterase function; 3) the third paradigm demonstrates that while oscillatory strain serves to relax adult ASM, the response in newborns is the potentiation of active stress. This is related to developmental changes in the cytoskeleton. Oscillatory stiffness is shown to relate inversely to the expression of myosin light chain kinase. This suggests that developmental changes in shortening relate inversely to the stiffness of the ASM early in shortening, suggesting a dynamic role for the cytoskeleton in facilitating and opposing ASM shortening. Together these paradigms demonstrate that ASM contributes by multiple mechanisms to the natural hyperresponsiveness of newborn and juvenile airways. Future studies will elaborate the mechanisms and extend these paradigms relate to ASM hyperresponsiveness that is increased

  7. Reactive oxygen species induce a Ca(2+)-spark increase in sensitized murine airway smooth muscle cells.

    PubMed

    Tuo, Qing-Rong; Ma, Yun-Fei; Chen, Weiwei; Luo, Xiao-Jing; Shen, Jinhua; Guo, Donglin; Zheng, Yun-Min; Wang, Yong-Xiao; Ji, Guangju; Liu, Qing-Hua

    2013-05-10

    The level of reactive oxygen species (ROS) and the activity of spontaneous, transient, localized Ca(2+) increases (known as Ca(2+) sparks) in tracheal smooth muscle cells (TSMCs) in an experimental allergic asthma mouse model has not yet been investigated. We used laser confocal microscopy and fluorescent dyes to measure ROS levels and Ca(2+) sparks, and we found that both events were significantly increased in TSMCs obtained from ovalbumin (OVA)-sensitized/-challenged mice compared with control mice. ROS levels began to increase in TSMCs after the first OVA challenge, and this increase was sustained. However, this elevation and Ca(2+)-spark increase was abolished after the administration of the ROS scavenger N-acetylcysteine amide (NACA) for 5days. Furthermore, a similar inhibition was also observed following the direct perfusion of NACA into cells isolated from the (OVA)-sensitized mice that were not treated with NACA. Moreover, we used 0.1-mM caffeine treatment to increase the Ca(2+) sparks in single TSMCs and observed cell shortening. In addition, we did not find increases in the mRNA levels of ryanodine (RyRs) and inositol 1,4,5-trisphosphate (IP3Rs) receptors in the tracheal smooth muscle cells of (OVA)-sensitized mice compared with controls. We concluded that ROS and Ca(2+) sparks increased in (OVA)-sensitized TSMCs. We found that ROS induces Ca(2+) sparks, and increased Ca(2+) sparks resulted in the contraction of (OVA)-sensitized TSMCs, resulting in the generation of airway hyperresponsiveness (AHR). This effect may represent a novel mechanism for AHR pathogenesis and might provide insight into new methods for the clinical prevention and treatment of asthma and asthmatic AHR. PMID:23583396

  8. TLR3 activation increases chemokine expression in human fetal airway smooth muscle cells.

    PubMed

    Faksh, Arij; Britt, Rodney D; Vogel, Elizabeth R; Thompson, Michael A; Pandya, Hitesh C; Martin, Richard J; Pabelick, Christina M; Prakash, Y S

    2016-01-15

    Viral infections, such as respiratory syncytial virus and rhinovirus, adversely affect neonatal and pediatric populations, resulting in significant lung morbidity, including acute asthma exacerbation. Studies in adults have demonstrated that human airway smooth muscle (ASM) cells modulate inflammation through their ability to secrete inflammatory cytokines and chemokines. The role of ASM in the developing airway during infection remains undefined. In our study, we used human fetal ASM cells as an in vitro model to examine the effect of Toll-like receptor (TLR) agonists on chemokine secretion. We found that fetal ASM express multiple TLRs, including TLR3 and TLR4, which are implicated in the pathogenesis of respiratory syncytial virus and rhinovirus infection. Cells were treated with TLR agonists, polyinosinic-polycytidylic acid [poly(I:C)] (TLR3 agonist), lipopolysaccharide (TLR4 agonist), or R848 (TLR7/8 agonist), and IL-8 and chemokine (C-C motif) ligand 5 (CCL5) secretion were evaluated. Interestingly, poly(I:C), but neither lipopolysaccharide nor R848, increased IL-8 and chemokine (C-C motif) ligand 5 secretion. Examination of signaling pathways suggested that the poly(I:C) effects in fetal ASM involve TLR and ERK signaling, in addition to another major inflammatory pathway, NF-κB. Moreover, there are variations between fetal and adult ASM with respect to poly(I:C) effects on signaling pathways. Pharmacological inhibition suggested that ERK pathways mediate poly(I:C) effects. Overall, our data show that poly(I:C) initiates activation of proinflammatory pathways in developing ASM, which may contribute to immune responses to infection and exacerbation of asthma. PMID:26589477

  9. Development and characterization of a 3D multicell microtissue culture model of airway smooth muscle

    PubMed Central

    Zaman, Nishat; Cole, Darren J.; Walker, Matthew J.; Legant, Wesley R.; Boudou, Thomas; Chen, Christopher S.; Favreau, John T.; Gaudette, Glenn R.; Cowley, Elizabeth A.; Maksym, Geoffrey N.

    2013-01-01

    Airway smooth muscle (ASM) cellular and molecular biology is typically studied with single-cell cultures grown on flat 2D substrates. However, cells in vivo exist as part of complex 3D structures, and it is well established in other cell types that altering substrate geometry exerts potent effects on phenotype and function. These factors may be especially relevant to asthma, a disease characterized by structural remodeling of the airway wall, and highlights a need for more physiologically relevant models of ASM function. We utilized a tissue engineering platform known as microfabricated tissue gauges to develop a 3D culture model of ASM featuring arrays of ∼0.4 mm long, ∼350 cell “microtissues” capable of simultaneous contractile force measurement and cell-level microscopy. ASM-only microtissues generated baseline tension, exhibited strong cellular organization, and developed actin stress fibers, but lost structural integrity and dissociated from the cantilevers within 3 days. Addition of 3T3-fibroblasts dramatically improved survival times without affecting tension development or morphology. ASM-3T3 microtissues contracted similarly to ex vivo ASM, exhibiting reproducible responses to a range of contractile and relaxant agents. Compared with 2D cultures, microtissues demonstrated identical responses to acetylcholine and KCl, but not histamine, forskolin, or cytochalasin D, suggesting that contractility is regulated by substrate geometry. Microtissues represent a novel model for studying ASM, incorporating a physiological 3D structure, realistic mechanical environment, coculture of multiple cells types, and comparable contractile properties to existing models. This new model allows for rapid screening of biochemical and mechanical factors to provide insight into ASM dysfunction in asthma. PMID:23125251

  10. MicroRNA Mediated Chemokine Responses in Human Airway Smooth Muscle Cells

    PubMed Central

    Dileepan, Mythili; Sarver, Anne E.; Rao, Savita P.; Panettieri, Reynold A.; Subramanian, Subbaya; Kannan, Mathur S.

    2016-01-01

    Airway smooth muscle (ASM) cells play a critical role in the pathophysiology of asthma due to their hypercontractility and their ability to proliferate and secrete inflammatory mediators. microRNAs (miRNAs) are gene regulators that control many signaling pathways and thus serve as potential therapeutic alternatives for many diseases. We have previously shown that miR-708 and miR-140-3p regulate the MAPK and PI3K signaling pathways in human ASM (HASM) cells following TNF-α exposure. In this study, we investigated the regulatory effect of these miRNAs on other asthma-related genes. Microarray analysis using the Illumina platform was performed with total RNA extracted from miR-708 (or control miR)-transfected HASM cells. Inhibition of candidate inflammation-associated gene expression was further validated by qPCR and ELISA. The most significant biologic functions for the differentially expressed gene set included decreased inflammatory response, cytokine expression and signaling. qPCR revealed inhibition of expression of CCL11, CXCL10, CCL2 and CXCL8, while the release of CCL11 was inhibited in miR-708-transfected cells. Transfection of cells with miR-140-3p resulted in inhibition of expression of CCL11, CXCL12, CXCL10, CCL5 and CXCL8 and of TNF-α-induced CXCL12 release. In addition, expression of RARRES2, CD44 and ADAM33, genes known to contribute to the pathophysiology of asthma, were found to be inhibited in miR-708-transfected cells. These results demonstrate that miR-708 and miR-140-3p exert distinct effects on inflammation-associated gene expression and biological function of ASM cells. Targeting these miRNA networks may provide a novel therapeutic mechanism to down-regulate airway inflammation and ASM proliferation in asthma. PMID:26998837

  11. Airway smooth muscle inflammation is regulated by microRNA-145 in COPD.

    PubMed

    O'Leary, Lawrence; Sevinç, Kenan; Papazoglou, Ilektra M; Tildy, Bernadett; Detillieux, Karen; Halayko, Andrew J; Chung, Kian Fan; Perry, Mark M

    2016-05-01

    Chronic obstructive pulmonary disease (COPD) is a common, highly debilitating disease of the airways, primarily caused by smoking. Chronic inflammation and structural remodelling are key pathological features of this disease, in part caused by the aberrant function of airway smooth muscle (ASM) cells under the regulation of transforming growth factor (TGF)-β. miRNA are short, noncoding gene transcripts involved in the negative regulation of specific target genes, through their interactions with mRNA. Previous studies have proposed that mRNA-145 (miR-145) may interact with SMAD3, an important downstream signalling molecule of the TGF-β pathway. TGF-β was used to stimulate primary human ASM cells isolated from healthy nonsmokers, healthy smokers and COPD patients. This resulted in a TGF-β-dependent increase in CXCL8 and IL-6 release, most notably in the cells from COPD patients. TGF-β stimulation increased SMAD3 expression, only in cells from COPD patients, with a concurrent increased miR-145 expression. Regulation of miR-145 was found to be negatively controlled by pathways involving the MAP kinases, MEK-1/2 and p38 MAPK. Subsequent, overexpression of miR-145 (using synthetic mimics) in ASM cells from patients with COPD suppressed IL-6 and CXCL8 release, to levels comparable to the nonsmoker controls. Therefore, this study suggests that miR-145 negatively regulates pro-inflammatory cytokine release from ASM cells in COPD by targeting SMAD3. PMID:27060571

  12. Human Lung Mast Cell Products Regulate Airway Smooth Muscle CXCL10 Levels

    PubMed Central

    Alkhouri, H.; Cha, V.; Tong, K.; Moir, L. M.; Armour, C. L.; Hughes, J. M.

    2014-01-01

    In asthma, the airway smooth muscle (ASM) produces CXCL10 which may attract CXCR3+ mast/T cells to it. Our aim was to investigate the effects of mast cell products on ASM cell CXCL10 production. ASM cells from people with and without asthma were stimulated with IL-1β, TNF-α, and/or IFNγ and treated with histamine (1–100 μM) ± chlorpheniramine (H1R antagonist; 1 μM) or ranitidine (H2R antagonist; 50 μM) or tryptase (1 nM) ± leupeptin (serine protease inhibitor; 50 μM), heat-inactivated tryptase, or vehicle for 4 h or 24 h. Human lung mast cells (MC) were isolated and activated with IgE/anti-IgE and supernatants were collected after 2 h or 24 h. The supernatants were added to ASM cells for 48 h and ASM cell CXCL10 production detected using ELISA (protein) and real-time PCR (mRNA). Histamine reduced IL-1β/TNF-α-induced CXCL10 protein, but not mRNA, levels independent of H1 and H2 receptor activation, whereas tryptase and MC 2 h supernatants reduced all cytokine-induced CXCL10. Tryptase also reduced CXCL10 levels in a cell-free system. Leupeptin inhibited the effects of tryptase and MC 2 h supernatants. MC 24 h supernatants contained TNF-α and amplified IFNγ-induced ASM cell CXCL10 production. This is the first evidence that MC can regulate ASM cell CXCL10 production and its degradation. Thus MC may regulate airway myositis in asthma. PMID:24648846

  13. MicroRNA Mediated Chemokine Responses in Human Airway Smooth Muscle Cells.

    PubMed

    Dileepan, Mythili; Sarver, Anne E; Rao, Savita P; Panettieri, Reynold A; Subramanian, Subbaya; Kannan, Mathur S

    2016-01-01

    Airway smooth muscle (ASM) cells play a critical role in the pathophysiology of asthma due to their hypercontractility and their ability to proliferate and secrete inflammatory mediators. microRNAs (miRNAs) are gene regulators that control many signaling pathways and thus serve as potential therapeutic alternatives for many diseases. We have previously shown that miR-708 and miR-140-3p regulate the MAPK and PI3K signaling pathways in human ASM (HASM) cells following TNF-α exposure. In this study, we investigated the regulatory effect of these miRNAs on other asthma-related genes. Microarray analysis using the Illumina platform was performed with total RNA extracted from miR-708 (or control miR)-transfected HASM cells. Inhibition of candidate inflammation-associated gene expression was further validated by qPCR and ELISA. The most significant biologic functions for the differentially expressed gene set included decreased inflammatory response, cytokine expression and signaling. qPCR revealed inhibition of expression of CCL11, CXCL10, CCL2 and CXCL8, while the release of CCL11 was inhibited in miR-708-transfected cells. Transfection of cells with miR-140-3p resulted in inhibition of expression of CCL11, CXCL12, CXCL10, CCL5 and CXCL8 and of TNF-α-induced CXCL12 release. In addition, expression of RARRES2, CD44 and ADAM33, genes known to contribute to the pathophysiology of asthma, were found to be inhibited in miR-708-transfected cells. These results demonstrate that miR-708 and miR-140-3p exert distinct effects on inflammation-associated gene expression and biological function of ASM cells. Targeting these miRNA networks may provide a novel therapeutic mechanism to down-regulate airway inflammation and ASM proliferation in asthma. PMID:26998837

  14. A novel role for RhoA GTPase in the regulation of airway smooth muscle contraction.

    PubMed

    Zhang, Wenwu; Huang, Youliang; Wu, Yidi; Gunst, Susan J

    2015-02-01

    Recent studies have demonstrated a novel molecular mechanism for the regulation of airway smooth muscle (ASM) contraction by RhoA GTPase. In ASM tissues, both myosin light chain (MLC) phosphorylation and actin polymerization are required for active tension generation. RhoA inactivation dramatically suppresses agonist-induced tension development and completely inhibits agonist-induced actin polymerization, but only slightly reduces MLC phosphorylation. The inhibition of MLC phosphatase does not reverse the effects of RhoA inactivation on contraction or actin polymerization. Thus, RhoA regulates ASM contraction through its effects on actin polymerization rather than MLC phosphorylation. Contractile stimulation of ASM induces the recruitment and assembly of paxillin, vinculin, and focal adhesion kinase (FAK) into membrane adhesion complexes (adhesomes) that regulate actin polymerization by catalyzing the activation of cdc42 GTPase by the G-protein-coupled receptor kinase-interacting target (GIT) - p21-activated kinase (PAK) - PAK-interacting exchange factor (PIX) complex. Cdc42 is a necessary and specific activator of the actin filament nucleation activator, N-WASp. The recruitment and activation of paxillin, vinculin, and FAK is prevented by RhoA inactivation, thus preventing cdc42 and N-WASp activation. We conclude that RhoA regulates ASM contraction by catalyzing the assembly and activation of membrane adhesome signaling modules that regulate actin polymerization, and that the RhoA-mediated assembly of adhesome complexes is a fundamental step in the signal transduction process in response to a contractile agonist. PMID:25531582

  15. Effects of acute ethanol exposure on cytokine production by primary airway smooth muscle cells.

    PubMed

    Kaphalia, Lata; Kalita, Mridul; Kaphalia, Bhupendra S; Calhoun, William J

    2016-02-01

    Both chronic and binge alcohol abuse can be significant risk factors for inflammatory lung diseases such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. However, metabolic basis of alcohol-related lung disease is not well defined, and may include key metabolites of ethanol [EtOH] in addition to EtOH itself. Therefore, we investigated the effects of EtOH, acetaldehyde [ACE], and fatty acid ethyl esters [FAEEs] on oxidative stress, endoplasmic reticulum (ER) stress, AMP-activated protein kinase (AMPK) signaling and nuclear translocation of phosphorylated (p)-NF-κB p65 in primary human airway smooth muscle (HASM) cells stimulated to produce cytokines using LPS exposure. Both FAEEs and ACE induced evidence of cellular oxidative stress and ER stress, and increased p-NF-κB in nuclear extracts. EtOH and its metabolites decreased p-AMPKα activation, and induced expression of fatty acid synthase, and decreased expression of sirtuin 1. In general, EtOH decreased secretion of IP-10, IL-6, eotaxin, GCSF, and MCP-1. However, FAEEs and ACE increased these cytokines, suggesting that both FAEEs and ACE as compared to EtOH itself are proinflammatory. A direct effect of EtOH could be consistent with blunted immune response. Collectively, these two features of EtOH exposure, coupled with the known inhibition of innate immune response in our model might explain some clinical manifestations of EtOH exposure in the lung. PMID:26721307

  16. Spatial and temporal traction response in human airway smooth muscle cells

    NASA Technical Reports Server (NTRS)

    Tolic-Norrelykke, Iva Marija; Butler, James P.; Chen, Jianxin; Wang, Ning

    2002-01-01

    Tractions that cells exert on their substrates are essential in cell spreading, migration, and contraction. These tractions can be determined by plating the cells on a flexible gel and measuring the deformation of the gel by using fluorescent beads embedded just below the surface of the gel. In this article we describe the image correlation method (ICM) optimized for determining the displacement field of the gel under a contracting cell. For the calculation of the traction field from the displacement field we use the recently developed method of Fourier transform traction cytometry (FTTC). The ICM and FTTC methods are applied to human airway smooth muscle cells during stimulation with the contractile agonist histamine or the relaxing agonist isoproterenol. The overall intensity of the cell contraction (the median traction magnitude, the energy transferred from the cell to the gel, and the net contractile moment) increased after activation with histamine, and decreased after treatment with isoproterenol. Cells exhibited regional differences in the time course of traction during the treatment. Both temporal evolution and magnitude of traction increase induced by histamine varied markedly among different cell protrusions, whereas the nuclear region showed the smallest response. These results suggest that intracellular mediators of cell adhesion and contraction respond to contractile stimuli with different rates and intensities in different regions of the cell.

  17. The effect of hyperpolarization-activated cyclic nucleotide-gated ion channel inhibitors on the vagal control of guinea pig airway smooth muscle tone

    PubMed Central

    McGovern, Alice E; Robusto, Jed; Rakoczy, Joanna; Simmons, David G; Phipps, Simon; Mazzone, Stuart B

    2014-01-01

    BACKGROUND AND PURPOSE Subtypes of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of cation channels are widely expressed on nerves and smooth muscle cells in many organ systems, where they serve to regulate membrane excitability. Here we have assessed whether HCN channel inhibitors alter the function of airway smooth muscle or the neurons that regulate airway smooth muscle tone. EXPERIMENTAL APPROACH The effects of the HCN channel inhibitors ZD7288, zatebradine and Cs+ were assessed on agonist and nerve stimulation-evoked changes in guinea pig airway smooth muscle tone using tracheal strips in vitro, an innervated tracheal tube preparation ex vivo or in anaesthetized mechanically ventilated guinea pigs in vivo. HCN channel expression in airway nerves was assessed using immunohistochemistry, PCR and in situ hybridization. KEY RESULTS HCN channel inhibition did not alter airway smooth muscle reactivity in vitro to exogenously administered smooth muscle spasmogens, but significantly potentiated smooth muscle contraction evoked by the sensory nerve stimulant capsaicin and electrical field stimulation of parasympathetic cholinergic postganglionic neurons. Sensory nerve hyperresponsiveness was also evident in in vivo following HCN channel blockade. Cs+, but not ZD7288, potentiated preganglionic nerve-dependent airway contractions and over time induced autorhythmic preganglionic nerve activity, which was not mimicked by inhibitors of potassium channels. HCN channel expression was most evident in vagal sensory ganglia and airway nerve fibres. CONCLUSIONS AND IMPLICATIONS HCN channel inhibitors had a previously unrecognized effect on the neural regulation of airway smooth muscle tone, which may have implications for some patients receiving HCN channel inhibitors for therapeutic purposes. PMID:24762027

  18. Chrysin inhibits human airway smooth muscle cells proliferation through the extracellular signal-regulated kinase 1/2 signaling pathway.

    PubMed

    Yao, Jing; Zhang, Yun-Shi; Feng, Gan-Zhu; Du, Qiang

    2015-11-01

    Asthma is a chronic airway inflammatory disease characterized by an increased mass of airway smooth muscle (ASM). Chrysin (5,7-dihydroxyflavone), a natural flavonoid, has been shown to exert multiple biological activities, including anti-inflammatory, anti-proliferative and anti-oxidant effects, as well as the potency to ameliorate asthma in animal models. The objective of the present study was to identify the underlying mechanism of the therapeutic effects of chrysin. The impact of chrysin on basal and platelet-derived growth factor (PDGF)-induced proliferation and apoptosis of human airway smooth muscle cells (HASMCs) was investigated. Furthermore, the activation of the extracellular signal-regulated protein kinase (ERK) signaling pathway was evaluated in HASMCs. The results revealed that chrysin significantly inhibited basal as well as PDGF-induced HASMC proliferation, most likely through the suppression of ERK1/2 phosphorylation. However, chrysin did not significantly reduce PDGF-induced apoptosis of HASMCs. The present study indicated that chrysin may be a promising medication for controlling airway remodeling and clinical manifestations of asthma. PMID:26502995

  19. Vitamin D Modulates Expression of the Airway Smooth Muscle Transcriptome in Fatal Asthma

    PubMed Central

    Johnson, Martin; Nikolos, Christina; Jester, William; Klanderman, Barbara; Litonjua, Augusto A.; Tantisira, Kelan G.; Truskowski, Kevin; MacDonald, Kevin; Panettieri, Reynold A.; Weiss, Scott T.

    2015-01-01

    Globally, asthma is a chronic inflammatory respiratory disease affecting over 300 million people. Some asthma patients remain poorly controlled by conventional therapies and experience more life-threatening exacerbations. Vitamin D, as an adjunct therapy, may improve disease control in severe asthma patients since vitamin D enhances glucocorticoid responsiveness and mitigates airway smooth muscle (ASM) hyperplasia. We sought to characterize differences in transcriptome responsiveness to vitamin D between fatal asthma- and non-asthma-derived ASM by using RNA-Seq to measure ASM transcript expression in five donors with fatal asthma and ten non-asthma-derived donors at baseline and with vitamin D treatment. Based on a Benjamini-Hochberg corrected p-value <0.05, 838 genes were differentially expressed in fatal asthma vs. non-asthma-derived ASM at baseline, and vitamin D treatment compared to baseline conditions induced differential expression of 711 and 867 genes in fatal asthma- and non-asthma-derived ASM, respectively. Functional gene categories that were highly represented in all groups included extracellular matrix, and responses to steroid hormone stimuli and wounding. Genes differentially expressed by vitamin D also included cytokine and chemokine activity categories. Follow-up qPCR and individual analyte ELISA experiments were conducted for four cytokines (i.e. CCL2, CCL13, CXCL12, IL8) to measure TNFα-induced changes by asthma status and vitamin D treatment. Vitamin D inhibited TNFα-induced IL8 protein secretion levels to a comparable degree in fatal asthma- and non-asthma-derived ASM even though IL8 had significantly higher baseline levels in fatal asthma-derived ASM. Our findings identify vitamin D-specific gene targets and provide transcriptomic data to explore differences in the ASM of fatal asthma- and non-asthma-derived donors. PMID:26207385

  20. Bidirectional counter-regulation of human lung mast cell and airway smooth muscle β2-adrenoceptors

    PubMed Central

    Newby, Chris; Amrani, Yassine; Bradding, Peter

    2015-01-01

    Human lung mast cells (HLMCs) play a central role in asthma pathogenesis through their relocation to the airway smooth muscle (ASM) bundles. β2 adrenoceptor (β2-AR)-agonists are used to relieve bronchoconstriction in asthma, but may reduce asthma control, particularly when used as monotherapy. We hypothesised that HLMC and human ASM cell (HASMC) responsiveness to β2-AR agonists would be attenuated when HLMCs are in contact with HASMCs. Cells were cultured in the presence of the short-acting β2-agonist albuterol, and the long-acting β2-agonists formoterol and olodaterol. Constitutive and FcεRI-dependent HLMC histamine release, HASMC contraction, and β2-AR phosphorylation at tyrosine 350 (Tyr350) were assessed. Constitutive HLMC histamine release was increased in HLMC-HASMC co-culture and this was enhanced by β2-AR agonists. Inhibition of FcεRI-dependent HLMC mediator release by β2-agonists was greatly reduced in HLMC-HASMC co-culture. These effects were reversed by neutralisation of stem cell factor (SCF) or cell adhesion molecule 1 (CADM1). β2-AR agonists did not prevent HASMC contraction when HLMCs were present, but this was reversed by fluticasone. β2-AR phosphorylation at Tyr350 occurred within 5 minutes in both HLMCs and HASMCs when the cells were co-cultured, and was inhibited by neutralising SCF or CADM1. HLMC interactions with HASMCs via CADM1 and Kit inhibit the potentially beneficial effects of β2-AR agonists on these cells via phosphorylation of the β2-AR. These results may explain the potentially adverse effects of β2-ARs agonists when used for asthma therapy. Targeting SCF and CADM1 may enhance β2-AR efficacy, particularly in corticosteroid-resistant patients. PMID:26608913

  1. A deterministic model predicts the properties of stochastic calcium oscillations in airway smooth muscle cells.

    PubMed

    Cao, Pengxing; Tan, Xiahui; Donovan, Graham; Sanderson, Michael J; Sneyd, James

    2014-08-01

    The inositol trisphosphate receptor ([Formula: see text]) is one of the most important cellular components responsible for oscillations in the cytoplasmic calcium concentration. Over the past decade, two major questions about the [Formula: see text] have arisen. Firstly, how best should the [Formula: see text] be modeled? In other words, what fundamental properties of the [Formula: see text] allow it to perform its function, and what are their quantitative properties? Secondly, although calcium oscillations are caused by the stochastic opening and closing of small numbers of [Formula: see text], is it possible for a deterministic model to be a reliable predictor of calcium behavior? Here, we answer these two questions, using airway smooth muscle cells (ASMC) as a specific example. Firstly, we show that periodic calcium waves in ASMC, as well as the statistics of calcium puffs in other cell types, can be quantitatively reproduced by a two-state model of the [Formula: see text], and thus the behavior of the [Formula: see text] is essentially determined by its modal structure. The structure within each mode is irrelevant for function. Secondly, we show that, although calcium waves in ASMC are generated by a stochastic mechanism, [Formula: see text] stochasticity is not essential for a qualitative prediction of how oscillation frequency depends on model parameters, and thus deterministic [Formula: see text] models demonstrate the same level of predictive capability as do stochastic models. We conclude that, firstly, calcium dynamics can be accurately modeled using simplified [Formula: see text] models, and, secondly, to obtain qualitative predictions of how oscillation frequency depends on parameters it is sufficient to use a deterministic model. PMID:25121766

  2. A-kinase-anchoring proteins coordinate inflammatory responses to cigarette smoke in airway smooth muscle

    PubMed Central

    Heijink, Irene H.; Holtzer, Laura J.; Skroblin, Philipp; Klussmann, Enno; Halayko, Andrew J.; Timens, Wim; Maarsingh, Harm; Schmidt, Martina

    2015-01-01

    β2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the β2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with β2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy. PMID:25637608

  3. A-kinase-anchoring proteins coordinate inflammatory responses to cigarette smoke in airway smooth muscle.

    PubMed

    Poppinga, Wilfred J; Heijink, Irene H; Holtzer, Laura J; Skroblin, Philipp; Klussmann, Enno; Halayko, Andrew J; Timens, Wim; Maarsingh, Harm; Schmidt, Martina

    2015-04-15

    β2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the β2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with β2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy. PMID:25637608

  4. Bidirectional Counterregulation of Human Lung Mast Cell and Airway Smooth Muscle β2 Adrenoceptors.

    PubMed

    Lewis, Rebecca J; Chachi, Latifa; Newby, Chris; Amrani, Yassine; Bradding, Peter

    2016-01-01

    Human lung mast cells (HLMCs) play a central role in asthma pathogenesis through their relocation to the airway smooth muscle (ASM) bundles. β2 adrenoceptor (β2-AR)-agonists are used to relieve bronchoconstriction in asthma, but may reduce asthma control, particularly when used as monotherapy. We hypothesized that HLMC and human ASM cell (HASMC) responsiveness to β2-AR agonists would be attenuated when HLMCs are in contact with HASMCs. Cells were cultured in the presence of the short-acting β2-agonist albuterol, and the long-acting β2-agonists formoterol and olodaterol. Constitutive and FcεRI-dependent HLMC histamine release, HASMC contraction, and β2-AR phosphorylation at Tyr(350) were assessed. Constitutive HLMC histamine release was increased in HLMC-HASMC coculture and this was enhanced by β2-AR agonists. Inhibition of FcεRI-dependent HLMC mediator release by β2-agonists was greatly reduced in HLMC-HASMC coculture. These effects were reversed by neutralization of stem cell factor (SCF) or cell adhesion molecule 1 (CADM1). β2-AR agonists did not prevent HASMC contraction when HLMCs were present, but this was reversed by fluticasone. β2-AR phosphorylation at Tyr(350) occurred within 5 min in both HLMCs and HASMCs when the cells were cocultured, and was inhibited by neutralizing SCF or CADM1. HLMC interactions with HASMCs via CADM1 and Kit inhibit the potentially beneficial effects of β2-AR agonists on these cells via phosphorylation of the β2-AR. These results may explain the potentially adverse effects of β2-ARs agonists when used for asthma therapy. Targeting SCF and CADM1 may enhance β2-AR efficacy, particularly in corticosteroid-resistant patients. PMID:26608913

  5. Myosin filament polymerization and depolymerization in a model of partial length adaptation in airway smooth muscle.

    PubMed

    Ijpma, Gijs; Al-Jumaily, Ahmed M; Cairns, Simeon P; Sieck, Gary C

    2011-09-01

    Length adaptation in airway smooth muscle (ASM) is attributed to reorganization of the cytoskeleton, and in particular the contractile elements. However, a constantly changing lung volume with tidal breathing (hence changing ASM length) is likely to restrict full adaptation of ASM for force generation. There is likely to be continuous length adaptation of ASM between states of incomplete or partial length adaption. We propose a new model that assimilates findings on myosin filament polymerization/depolymerization, partial length adaptation, isometric force, and shortening velocity to describe this continuous length adaptation process. In this model, the ASM adapts to an optimal force-generating capacity in a repeating cycle of events. Initially the myosin filament, shortened by prior length changes, associates with two longer actin filaments. The actin filaments are located adjacent to the myosin filaments, such that all myosin heads overlap with actin to permit maximal cross-bridge cycling. Since in this model the actin filaments are usually longer than myosin filaments, the excess length of the actin filament is located randomly with respect to the myosin filament. Once activated, the myosin filament elongates by polymerization along the actin filaments, with the growth limited by the overlap of the actin filaments. During relaxation, the myosin filaments dissociate from the actin filaments, and then the cycle repeats. This process causes a gradual adaptation of force and instantaneous adaptation of shortening velocity. Good agreement is found between model simulations and the experimental data depicting the relationship between force development, myosin filament density, or shortening velocity and length. PMID:21659490

  6. Airway smooth muscle dysfunction precedes teratogenic congenital diaphragmatic hernia and may contribute to hypoplastic lung morphogenesis.

    PubMed

    Featherstone, Neil C; Connell, Marilyn G; Fernig, David G; Wray, Susan; Burdyga, Theodor V; Losty, Paul D; Jesudason, Edwin C

    2006-11-01

    Fetal intervention aims to improve lung growth and survival in congenital diaphragmatic hernia (CDH). Airway smooth muscle (ASM) is important in lung development: ASM progenitors produce a key growth factor for lung morphogenesis (fibroblast growth factor 10); ASM contractility is also coupled to growth. ASM hyperreactivity occurs in postnatal CDH and may exacerbate barotrauma via impaired lung compliance. We hypothesize that ASM hyperreactivity and its sequelae are based on an early developmental lesion of ASM activity in hypoplastic lung. Sprague-Dawley rats were fed 100 mg nitrofen on Day 9.5 of pregnancy to induce lung hypoplasia in offspring (controls had vehicle alone). Normal and hypoplastic lung primordia were cultured from Day 13.5 of gestation at 37 degrees C in 5% CO(2) and loaded at 54 or 78 h with Ca(2+)-sensitive indicators: Fluo-4 for confocal imaging and Indo-1 or Fura-2 for photometric measurements of [Ca(2+)](i). Hypoplastic lung features spontaneous propagating ASM Ca(2+) transients with reduced frequency, increased amplitude, and significantly prolonged plateau duration, relative to control lung. Nonetheless, hypoplastic lung exhibits normal requirement for extracellular calcium entry and intracellular calcium release in initiation and regulation of ASM Ca(2+) waves. Early ASM dysfunction in lung hypoplasia is apparent as specific anomalies of Ca(2+) transients that indicate a problem with plasmalemmal ion channels/action potential generation. Elucidation of such an ASM lesion may allow pharmacologic amelioration not only of ASM hyperreactivity and its sequelae, but also of hypoplastic lung growth itself. PMID:16728706

  7. Biological characteristics of tracheal smooth muscle cells regulated by NK-1R in asthmatic rat with airway remodeling

    PubMed Central

    Wei, Bing; Liu, Yali; Yue, Xiaozhe; Li, Yinping; Shang, Yunxiao

    2015-01-01

    This study aims to investigate the biological characteristic changes of infant rat tracheal smooth muscle cells in asthma airway remodeling and the impact of NK-1R on the mechanism. Ovalbumin (OVA) was used to excited juvenile SD rats by 8 w. Immunofluorescence, MTT assay, transwell chambers, real time quantitative PCR, Western blot and other methods were used to observe the proliferation, migration, synthesis and secretion changes of infant airway remodeling in rat tracheal smooth muscle cell and the Neurokinin 1 receptor (NK-1R) expression. 1. NK-1R mRNA, protein expression of airway smooth muscle cell (ASMC) of each asthma group were higher than that of the control group, especially the asthma 8 w group had highest expression (P<0.01). 2. The average A value of 8 w asthma group measured by MTT method were significantly higher than that of the control group (P<0.05), WIN62577 10-8 mol/L group had the strongest inhibition of ASMC proliferation (P<0.01). 3. The number of cell migration in the asthma group significantly increased than that in the control group. The number of migrating cells in the NK-1R antagonist group significantly reduced compared with the asthma 8 w group (P<0.05). 4. The average gray value of type III collagen in each asthma group were higher than that of the control group, and the asthma 8 w group had the highest (P<0.01). After NK-1R blocking, the average gray value of type III collagen was significantly lower (P<0.05). ASMC proliferation, migration, synthesis and secretion function increased in the airway remodeling group, and NK-1R played an important role. PMID:26628953

  8. YAP is up-regulated in the bronchial airway smooth muscle of the chronic asthma mouse model.

    PubMed

    Zhou, Jing; Xu, Fei; Yu, Jing Jing; Zhang, Wei

    2015-01-01

    Asthma is characterized by leukocytic infiltration and tissue remodeling with structural changes including subepithelial fibrosis and ASM cells proliferation. The Hippo pathway is a key regulatory point involved in cell proliferation, fibroblasts, and smooth muscle cell differentiation. In order to disclose the relation between asthma and the Hippo pathway, expression of the Yes-associated protein (YAP), a key gene in the Hippo pathway, in the bronchial smooth muscle of chronic asthma model (CAM) was studied. 40 mice were randomly divided into control (wide type) and experimental group to construct CAM using chicken ovalbumin (OVA). Pathological changes of the lung tissues were observed in the CAM mice compared with the control using HE staining method. Immunohistochemistry (IHC) was used to detect if YAP protein is expressed in the lung tissues. The pathological changes of the CAM group showed that a large number of inflammatory cells infiltration including mainly lymphocytes and a small amount of eosinophilic, with the presence of certain airway smooth muscle hyperplasia, was observed in comparison with the control. IHC results showed that the YAP protein was significantly increased compared with the control groups (P < 0.01). This result was further confirmed by quantitative real-time PCR (qPCR) assay which detected the up-regulation of the YAP gene (P < 0.01) and Western blot. In conclusion, the YAP protein was significantly expressed in the bronchial airway tissues of the CAM mice, and could be used as an indicator for asthma. PMID:26617833

  9. The Pro-Proliferative Effects of Nicotine and Its Underlying Mechanism on Rat Airway Smooth Muscle Cells

    PubMed Central

    He, Fang; Li, Bing; Zhao, Zhuxiang; Zhou, Yumin; Hu, Guoping; Zou, Weifeng; Hong, Wei; Zou, Yimin; Jiang, Changbin; Zhao, Dongxing; Ran, Pixin

    2014-01-01

    Recent studies have shown that nicotine, a major component of cigarette smoke, can stimulate the proliferation of non-neuronal cells. Cigarette smoking can promote a variety of pulmonary and cardiovascular diseases, such as chronic obstructive pulmonary disease (COPD), atherosclerosis, and cancer. A predominant feature of COPD is airway remodeling, which includes increased airway smooth muscle (ASM) mass. The mechanisms underlying ASM remodeling in COPD have not yet been fully elucidated. Here, we show that nicotine induces a profound and time-dependent increase in DNA synthesis in rat airway smooth muscle cells (RASMCs) in vitro. Nicotine also significantly increased the number of RASMCs, which was associated with the increased expression of Cyclin D1, phosphorylation of the retinoblastoma protein (RB) and was dependent on the activation of Akt. The activation of Akt by nicotine occurred within minutes and depended upon the nicotinic acetylcholine receptors (nAchRs). Activated Akt increased the phosphorylation of downstream substrates such as GSK3β. Our data suggest that the binding of nicotine to the nAchRs on RASMCs can regulate cellular proliferation by activating the Akt pathway. PMID:24690900

  10. Glucocorticoid and TNF signaling converge at A20 (TNFAIP3) to repress airway smooth muscle cytokine expression.

    PubMed

    Sasse, Sarah K; Altonsy, Mohammed O; Kadiyala, Vineela; Cao, Gaoyuan; Panettieri, Reynold A; Gerber, Anthony N

    2016-08-01

    Airway smooth muscle is a major target tissue for glucocorticoid (GC)-based asthma therapies, however, molecular mechanisms through which the GC receptor (GR) exerts therapeutic effects in this key airway cell type have not been fully elucidated. We previously identified the nuclear factor-κB (NF-κB) inhibitor, A20 (TNFAIP3), as a mediator of cytokine repression by glucocorticoids (GCs) in airway epithelial cells and defined cooperative regulation of anti-inflammatory genes by GR and NF-κB as a key mechanistic underpinning of airway epithelial GR function. Here, we expand on these findings to determine whether a similar mechanism is operational in human airway smooth muscle (HASM). Using HASM cells derived from normal and fatal asthma samples as an in vitro model, we demonstrate that GCs spare or augment TNF-mediated induction of A20 (TNFAIP3), TNIP1, and NFKBIA, all implicated in negative feedback control of NF-κB-driven inflammatory processes. We applied chromatin immunoprecipitation and reporter analysis to show that GR and NF-κB directly regulate A20 expression in HASM through cooperative induction of an intronic enhancer. Using overexpression, we show for the first time that A20 and its interacting partner, TNIP1, repress TNF signaling in HASM cells. Moreover, we applied small interfering RNA-based gene knockdown to demonstrate that A20 is required for maximal cytokine repression by GCs in HASM. Taken together, our data suggest that inductive regulation of A20 by GR and NF-κB contributes to cytokine repression in HASM. PMID:27371733

  11. Exploiting the relationship between birefringence and force to measure airway smooth muscle contraction with PS-OCT (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Adams, David C.; Hariri, Lida P.; Holz, Jasmin A.; Szabari, Margit V.; Harris, R. Scott; Cho, Jocelyn L.; Hamilos, Daniel L.; Luster, Andrew D.; Medoff, Benjamin D.; Suter, Melissa J.

    2016-03-01

    The ability to observe airway dynamics is fundamental to forming a complete understanding of pulmonary diseases such as asthma. We have previously demonstrated that Optical Coherence Tomography (OCT) can be used to observe structural changes in the airway during bronchoconstriction, but standard OCT lacks the contrast to discriminate airway smooth muscle (ASM) bands- ASM being responsible for generating the force that drives airway constriction- from the surrounding tissue. Since ASM in general exhibits a greater degree of birefringence than the surrounding tissue, a potential solution to this problem lies in the implementation of polarization sensitivity (PS) to the OCT system. By modifying the OCT system so that it is sensitive to the birefringence of tissue under inspection, we can visualize the ASM with much greater clarity and definition. In this presentation we show that the force of contraction can be indirectly measured by an associated increase in the birefringence signal of the ASM. We validate this approach by attaching segments of swine trachea to an isometric force transducer and stimulating contraction, while simultaneously measuring the exerted force and imaging the segment with PS-OCT. We then show how our results may be used to extrapolate the force of contraction of closed airways in absence of additional measurement devices. We apply this technique to assess ASM contractility volumetrically and in vivo, in both asthmatic and non-asthmatic human volunteers.

  12. Arachidonate-Regulated Ca2+ Influx in Human Airway Smooth Muscle

    PubMed Central

    Thompson, Michael A.; Prakash, Y. S.

    2014-01-01

    Plasma membrane Ca2+ influx, especially store-operated Ca2+ entry triggered by sarcoplasmic reticulum (SR) Ca2+ release, is a key component of intracellular calcium concentration ([Ca2+]i) regulation in airway smooth muscle (ASM). Agonist-induced Ca2+ oscillations in ASM that involve both influx and SR mechanisms have been previously demonstrated. In nonexcitable cells, [Ca2+]i oscillations involve Ca2+ influx via arachidonic acid (AA) –stimulated channels, which show similarities to store-operated Ca2+ entry, although their molecular identity remains undetermined. Little is known about AA-regulated Ca2+ channels or their regulation in ASM. In enzymatically dissociated human ASM cells loaded with the Ca2+ indicator, fura-2, AA (1–10 μM) triggered [Ca2+]i oscillations that were inhibited by removal of extracellular Ca2+. Other fatty acids, such as the diacylglycerol analog, 1-oleoyl-2-acetyl-SN-glycerol, oleic acid, and palmitic acid (10 μM each), failed to elicit similar [Ca2+]i responses. Preincubation with LaCl3 (1 μM or 1 mM) inhibited AA-induced oscillations. Inhibition of receptor-operated channels (SKF96,365 [10 μM]), lipoxygenase (zileuton [10 μM]), or cyclooxygenase (indomethacin [10 μM]) did not affect oscillation parameters. Inhibition of SR Ca2+ release (ryanodine [10 μM] or inositol 1,4,5-trisphosphate receptor inhibitor, xestospongin C [1 μM]) decreased [Ca2+]i oscillation frequency and amplitude. Small interfering RNA against caveolin-1, stromal interaction molecule 1, or Orai3 (20 nM each) reduced the frequency and amplitude of AA-induced [Ca2+]i oscillations. In ASM cells derived from individuals with asthma, AA increased oscillation amplitude, but not frequency. These results are highly suggestive of a novel AA-mediated Ca2+–regulatory mechanism in human ASM, reminiscent of agonist-induced oscillations. Given the role of AA in ASM intracellular signaling, especially with inflammation, AA-regulated Ca2+ channels could potentially

  13. Nonadrenergic, noncholinergic responses stabilize smooth muscle tone, with and without parasympathetic activation, in guinea-pig isolated airways.

    PubMed

    Lindén, A; Löfdahl, C G; Ullman, A; Skoogh, B E

    1993-03-01

    In guinea-pig isolated airways, nonadrenergic, noncholinergic (NANC) neural responses converge towards a similar level of smooth muscle tone, via a contraction when the tone is low prior to stimulation, and via a relaxation when the tone is high prior to stimulation. We wanted to assess the effect of simultaneous parasympathetic activation on these converging NANC responses, with and without the addition of sympathetic activation. In guinea-pig isolated airways, the spontaneous airway tone was initially abolished by indomethacin (10 microM). In one series, adrenergic depletion by guanethidine (10 microM) was then established, with and without cholinergic blockade by atropine (1 microM). In another series, either cholinergic blockade by atropine (1 microM) or no blockade was utilized. Responses to electrical field stimulation (1,200 mA, 0.5 ms, 3 Hz for 240 s) were studied with no induced tone, at a moderate (0.3 microM) and at a near-maximum (6 microM), histamine-induced tone. The mean level of the tonus equilibrium (% of maximum tone) was higher with the simultaneous NANC and parasympathetic activation than with NANC activation alone (75% compared with 44%, in the main bronchus, n = 8). The level of the tonus equilibrium was also higher with the simultaneous NANC, sympathetic and parasympathetic activation than with NANC and sympathetic activation only (49% compared with 21%, in the main bronchus, n = 8). The pattern was similar in the distal trachea. In conclusion, NANC neural responses can stabilize smooth muscle tone, and this stabilizing effect can be modulated by both parasympathetic and sympathetic activation, in guinea-pig isolated airways. PMID:8472834

  14. Hydrogen sulphide inhibits Ca2+ release through InsP3 receptors and relaxes airway smooth muscle

    PubMed Central

    Castro-Piedras, Isabel; Perez-Zoghbi, Jose F

    2013-01-01

    Hydrogen sulphide (H2S) is a signalling molecule that appears to regulate diverse cell physiological process in several organs and systems including vascular and airway smooth muscle cell (SMC) contraction. Decreases in endogenous H2S synthesis have been associated with the development of cardiovascular diseases and asthma. Here we investigated the mechanism of airway SMC relaxation induced by H2S in small intrapulmonary airways using mouse lung slices and confocal and phase-contrast video microscopy. Exogenous H2S donor Na2S (100 μm) reversibly inhibited Ca2+ release and airway contraction evoked by inositol-1,4,5-trisphosphate (InsP3) uncaging in airway SMCs. Similarly, InsP3-evoked Ca2+ release and contraction was inhibited by endogenous H2S precursor l-cysteine (10 mm) but not by l-serine (10 mm) or either amino acid in the presence of dl-propargylglycine (PPG). Consistent with the inhibition of Ca2+ release through InsP3 receptors (InsP3Rs), Na2S reversibly inhibited acetylcholine (ACh)-induced Ca2+ oscillations in airway SMCs. In addition, Na2S, the H2S donor GYY-4137, and l-cysteine caused relaxation of airways pre-contracted with either ACh or 5-hydroxytryptamine (5-HT). Na2S-induced airway relaxation was resistant to a guanylyl cyclase inhibitor (ODQ) and a protein kinase G inhibitor (Rp-8-pCPT-cGMPS). The effects of H2S on InsP3-evoked Ca2+ release and contraction as well as on the relaxation of agonist-contracted airways were mimicked by the thiol-reducing agent dithiothreitol (DTT, 10 mm) and inhibited by the oxidizing agent diamide (30 μm). These studies indicate that H2S causes airway SMC relaxation by inhibiting Ca2+ release through InsP3Rs and consequent reduction of agonist-induced Ca2+ oscillations in SMCs. The results suggest a novel role for endogenously produced H2S that involves the modulation of InsP3-evoked Ca2+ release – a cell-signalling system of critical importance for many physiological and pathophysiological processes. PMID

  15. Hydrogen sulphide inhibits Ca2+ release through InsP3 receptors and relaxes airway smooth muscle.

    PubMed

    Castro-Piedras, Isabel; Perez-Zoghbi, Jose F

    2013-12-01

    Hydrogen sulphide (H2S) is a signalling molecule that appears to regulate diverse cell physiological process in several organs and systems including vascular and airway smooth muscle cell (SMC) contraction. Decreases in endogenous H2S synthesis have been associated with the development of cardiovascular diseases and asthma. Here we investigated the mechanism of airway SMC relaxation induced by H2S in small intrapulmonary airways using mouse lung slices and confocal and phase-contrast video microscopy. Exogenous H2S donor Na2S (100 μm) reversibly inhibited Ca(2+) release and airway contraction evoked by inositol-1,4,5-trisphosphate (InsP3) uncaging in airway SMCs. Similarly, InsP3-evoked Ca(2+) release and contraction was inhibited by endogenous H2S precursor l-cysteine (10 mm) but not by l-serine (10 mm) or either amino acid in the presence of dl-propargylglycine (PPG). Consistent with the inhibition of Ca(2+) release through InsP3 receptors (InsP3Rs), Na2S reversibly inhibited acetylcholine (ACh)-induced Ca(2+) oscillations in airway SMCs. In addition, Na2S, the H2S donor GYY-4137, and l-cysteine caused relaxation of airways pre-contracted with either ACh or 5-hydroxytryptamine (5-HT). Na2S-induced airway relaxation was resistant to a guanylyl cyclase inhibitor (ODQ) and a protein kinase G inhibitor (Rp-8-pCPT-cGMPS). The effects of H2S on InsP3-evoked Ca(2+) release and contraction as well as on the relaxation of agonist-contracted airways were mimicked by the thiol-reducing agent dithiothreitol (DTT, 10 mm) and inhibited by the oxidizing agent diamide (30 μm). These studies indicate that H2S causes airway SMC relaxation by inhibiting Ca(2+) release through InsP3Rs and consequent reduction of agonist-induced Ca(2+) oscillations in SMCs. The results suggest a novel role for endogenously produced H2S that involves the modulation of InsP3-evoked Ca(2+) release - a cell-signalling system of critical importance for many physiological and pathophysiological processes

  16. The Oligo Fucoidan Inhibits Platelet-Derived Growth Factor-Stimulated Proliferation of Airway Smooth Muscle Cells

    PubMed Central

    Yang, Chao-Huei; Tsao, Chiung-Fang; Ko, Wang-Sheng; Chiou, Ya-Ling

    2016-01-01

    In the pathogenesis of asthma, the proliferation of airway smooth muscle cells (ASMCs) is a key factor in airway remodeling and causes airway narrowing. In addition, ASMCs are also the effector cells of airway inflammation. Fucoidan extracted from marine brown algae polysaccharides has antiviral, antioxidant, antimicrobial, anticlotting, and anticancer properties; however, its effectiveness for asthma has not been elucidated thus far. Platelet-derived growth factor (PDGF)-treated primary ASMCs were cultured with or without oligo-fucoidan (100, 500, or 1000 µg/mL) to evaluate its effects on cell proliferation, cell cycle, apoptosis, and Akt, ERK1/2 signaling pathway. We found that PDGF (40 ng/mL) increased the proliferation of ASMCs by 2.5-fold after 48 h (p < 0.05). Oligo-fucoidan reduced the proliferation of PDGF-stimulated ASMCs by 75%–99% after 48 h (p < 0.05) and induced G1/G0 cell cycle arrest, but did not induce apoptosis. Further, oligo-fucoidan supplementation reduced PDGF-stimulated extracellular signal-regulated kinase (ERK1/2), Akt, and nuclear factor (NF)-κB phosphorylation. Taken together, oligo-fucoidan supplementation might reduce proliferation of PDGF-treated ASMCs through the suppression of ERK1/2 and Akt phosphorylation and NF-κB activation. The results provide basis for future animal experiments and human trials. PMID:26761017

  17. Cyclic mechanical strain-induced proliferation and migration of human airway smooth muscle cells: role of EMMPRIN and MMPs.

    PubMed

    Hasaneen, Nadia A; Zucker, Stanley; Cao, Jian; Chiarelli, Christian; Panettieri, Reynold A; Foda, Hussein D

    2005-09-01

    Airway smooth muscle (ASM) proliferation and migration are major components of airway remodeling in asthma. Asthmatic airways are exposed to mechanical strain, which contributes to their remodeling. Matrix metalloproteinase (MMP) plays an important role in remodeling. In the present study, we examined if the mechanical strain of human ASM (HASM) cells contributes to their proliferation and migration and the role of MMPs in this process. HASM were exposed to mechanical strain using the FlexCell system. HASM cell proliferation, migration and MMP release, activation, and expression were assessed. Our results show that cyclic strain increased the proliferation and migration of HASM; cyclic strain increased release and activation of MMP-1, -2, and -3 and membrane type 1-MMP; MMP release was preceded by an increase in extracellular MMP inducer; Prinomastat [a MMP inhibitor (MMPI)] significantly decreased cyclic strain-induced proliferation and migration of HASM; and the strain-induced increase in the release of MMPs was accompanied by an increase in tenascin-C release. In conclusion, cyclic mechanical strain plays an important role in HASM cell proliferation and migration. This increase in proliferation and migration is through an increase in MMP release and activation. Pharmacological MMPIs should be considered in the pursuit of therapeutic options for airway remodeling in asthma. PMID:16014803

  18. Does smooth muscle in an intact airway undergo length adaptation during a sustained change in transmural pressure?

    PubMed

    Ansell, Thomas K; McFawn, Peter K; McLaughlin, Robert A; Sampson, David D; Eastwood, Peter R; Hillman, David R; Mitchell, Howard W; Noble, Peter B

    2015-03-01

    In isolated airway smooth muscle (ASM) strips, an increase or decrease in ASM length away from its current optimum length causes an immediate reduction in force production followed by a gradual time-dependent recovery in force, a phenomenon termed length adaptation. In situ, length adaptation may be initiated by a change in transmural pressure (Ptm), which is a primary physiological determinant of ASM length. The present study sought to determine the effect of sustained changes in Ptm and therefore, ASM perimeter, on airway function. We measured contractile responses in whole porcine bronchial segments in vitro before and after a sustained inflation from a baseline Ptm of 5 cmH2O to 25 cmH2O, or deflation to -5 cmH2O, for ∼50 min in each case. In one group of airways, lumen narrowing and stiffening in response to electrical field stimulation (EFS) were assessed from volume and pressure signals using a servo-controlled syringe pump with pressure feedback. In a second group of airways, lumen narrowing and the perimeter of the ASM in situ were determined by anatomical optical coherence tomography. In a third group of airways, active tension was determined under isovolumic conditions. Both inflation and deflation reduced the contractile response to EFS. Sustained Ptm change resulted in a further decrease in contractile response, which returned to baseline levels upon return to the baseline Ptm. These findings reaffirm the importance of Ptm in regulating airway narrowing. However, they do not support a role for ASM length adaptation in situ under physiological levels of ASM lengthening and shortening. PMID:25729015

  19. Nuclear factor-κB mediates the phenotype switching of airway smooth muscle cells in a murine asthma model

    PubMed Central

    Qiu, Chen; Zhang, Jian; Su, Meiping; Fan, Xiujun

    2015-01-01

    Airway smooth muscle cells (ASMCs) phenotype modulation, characterized by reversible switching between contractile and proliferative phenotypes, is considered to contribute to airway proliferative diseases such as allergic asthma. Nuclear Factor-κB (NF-κB) has been reported as a key regulator for the occurrence and development of asthma. However, little is known regarding its role in ASM cell phenotypic modulation. To elucidate the role of NF-κB in regulating ASM cells phenotypic modulation, we investigated the effects of NF-κB on ASM cells contractile marker protein expression, and its impact on proliferation and apoptosis. We found that chronic asthma increased the activation of NF-κB in the primary murine ASM cells with a concomitant marked decrease in the expression of contractile phenotypic marker protein including smooth muscle alpha-actin (α-SMA). Additionally, we used the normal ASM cells under different processing to build the phenotype switching when we found the activation of NF-κB. Meanwhile, the expression of α-SMA in asthma was significantly increased by the NF-κB blocker. NF-κB blocker also suppressed asthma mouse ASM cell proliferation and promoted apoptosis. These findings highlight a novel role for the NF-κB in murine ASM cell phenotypic modulation and provide a potential target for therapeutic intervention for asthma. PMID:26722396

  20. Protective effects of anisodamine on cigarette smoke extract-induced airway smooth muscle cell proliferation and tracheal contractility

    SciTech Connect

    Xu, Guang-Ni; Yang, Kai; Xu, Zu-Peng; Zhu, Liang; Hou, Li-Na; Qi, Hong; Chen, Hong-Zhuan Cui, Yong-Yao

    2012-07-01

    Anisodamine, an antagonist of muscarinic acetylcholine receptors (mAChRs), has been used therapeutically to improve smooth muscle function, including microvascular, intestinal and airway spasms. Our previous studies have revealed that airway hyper-reactivity could be prevented by anisodamine. However, whether anisodamine prevents smoking-induced airway smooth muscle (ASM) cell proliferation remained unclear. In this study, a primary culture of rat ASM cells was used to evaluate an ASM phenotype through the ability of the cells to proliferate and express contractile proteins in response to cigarette smoke extract (CSE) and intervention of anisodamine. Our results showed that CSE resulted in an increase in cyclin D1 expression concomitant with the G0/G1-to-S phase transition, and high expression of M2 and M3. Functional studies showed that tracheal hyper-contractility accompanied contractile marker α-SMA high-expression. These changes, which occur only after CSE stimulation, were prevented and reversed by anisodamine, and CSE-induced cyclin D1 expression was significantly inhibited by anisodamine and the specific inhibitor U0126, BAY11-7082 and LY294002. Thus, we concluded that the protective and reversal effects and mechanism of anisodamine on CSE-induced events might involve, at least partially, the ERK, Akt and NF-κB signaling pathways associated with cyclin D1 via mAChRs. Our study validated that anisodamine intervention on ASM cells may contribute to anti-remodeling properties other than bronchodilation. -- Highlights: ► CSE induces tracheal cell proliferation, hyper-contractility and α-SMA expression. ► Anisodamine reverses CSE-induced tracheal hyper-contractility and cell proliferation. ► ERK, PI3K, and NF-κB pathways and cyclin D1 contribute to the reversal effect.

  1. Real-time imaging of ATP release induced by mechanical stretch in human airway smooth muscle cells.

    PubMed

    Takahara, Norihiro; Ito, Satoru; Furuya, Kishio; Naruse, Keiji; Aso, Hiromichi; Kondo, Masashi; Sokabe, Masahiro; Hasegawa, Yoshinori

    2014-12-01

    Airway smooth muscle (ASM) cells within the airway walls are continually exposed to mechanical stimuli, and exhibit various functions in response to these mechanical stresses. ATP acts as an extracellular mediator in the airway. Moreover, extracellular ATP is considered to play an important role in the pathophysiology of asthma and chronic obstructive pulmonary disease. However, it is not known whether ASM cells are cellular sources of ATP secretion in the airway. We therefore investigated whether mechanical stretch induces ATP release from ASM cells. Mechanical stretch was applied to primary human ASM cells cultured on a silicone chamber coated with type I collagen using a stretching apparatus. Concentrations of ATP in cell culture supernatants measured by luciferin-luciferase bioluminescence were significantly elevated by cyclic stretch (12 and 20% strain). We further visualized the stretch-induced ATP release from the cells in real time using a luminescence imaging system, while acquiring differential interference contrast cell images with infrared optics. Immediately after a single uniaxial stretch for 1 second, strong ATP signals were produced by a certain population of cells and spread to surrounding spaces. The cyclic stretch-induced ATP release was significantly reduced by inhibitors of Ca(2+)-dependent vesicular exocytosis, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl ester, monensin, N-ethylmaleimide, and bafilomycin. In contrast, the stretch-induced ATP release was not inhibited by a hemichannel blocker, carbenoxolone, or blockade of transient receptor potential vanilloid 4 by short interfering RNA transfection or ruthenium red. These findings reveal a novel property of ASM cells: mechanically induced ATP release may be a cellular source of ATP in the airway. PMID:24885163

  2. Kv7 potassium channels in airway smooth muscle cells: signal transduction intermediates and pharmacological targets for bronchodilator therapy.

    PubMed

    Brueggemann, Lioubov I; Kakad, Priyanka P; Love, Robert B; Solway, Julian; Dowell, Maria L; Cribbs, Leanne L; Byron, Kenneth L

    2012-01-01

    Expression and function of Kv7 (KCNQ) voltage-activated potassium channels in guinea pig and human airway smooth muscle cells (ASMCs) were investigated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), patch-clamp electrophysiology, and precision-cut lung slices. qRT-PCR revealed expression of multiple KCNQ genes in both guinea pig and human ASMCs. Currents with electrophysiological and pharmacological characteristics of Kv7 currents were measured in freshly isolated guinea pig and human ASMCs. In guinea pig ASMCs, Kv7 currents were significantly suppressed by application of the bronchoconstrictor agonists methacholine (100 nM) or histamine (30 μM), but current amplitudes were restored by addition of a Kv7 channel activator, flupirtine (10 μM). Kv7 currents in guinea pig ASMCs were also significantly enhanced by another Kv7.2-7.5 channel activator, retigabine, and by celecoxib and 2,5-dimethyl celecoxib. In precision-cut human lung slices, constriction of airways by histamine was significantly reduced in the presence of flupirtine. Kv7 currents in both guinea pig and human ASMCs were inhibited by the Kv7 channel blocker XE991. In human lung slices, XE991 induced robust airway constriction, which was completely reversed by addition of the calcium channel blocker verapamil. These findings suggest that Kv7 channels in ASMCs play an essential role in the regulation of airway diameter and may be targeted pharmacologically to relieve airway hyperconstriction induced by elevated concentrations of bronchoconstrictor agonists. PMID:21964407

  3. Kv7 potassium channels in airway smooth muscle cells: signal transduction intermediates and pharmacological targets for bronchodilator therapy

    PubMed Central

    Brueggemann, Lioubov I.; Kakad, Priyanka P.; Love, Robert B.; Solway, Julian; Dowell, Maria L.; Cribbs, Leanne L.

    2012-01-01

    Expression and function of Kv7 (KCNQ) voltage-activated potassium channels in guinea pig and human airway smooth muscle cells (ASMCs) were investigated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), patch-clamp electrophysiology, and precision-cut lung slices. qRT-PCR revealed expression of multiple KCNQ genes in both guinea pig and human ASMCs. Currents with electrophysiological and pharmacological characteristics of Kv7 currents were measured in freshly isolated guinea pig and human ASMCs. In guinea pig ASMCs, Kv7 currents were significantly suppressed by application of the bronchoconstrictor agonists methacholine (100 nM) or histamine (30 μM), but current amplitudes were restored by addition of a Kv7 channel activator, flupirtine (10 μM). Kv7 currents in guinea pig ASMCs were also significantly enhanced by another Kv7.2–7.5 channel activator, retigabine, and by celecoxib and 2,5-dimethyl celecoxib. In precision-cut human lung slices, constriction of airways by histamine was significantly reduced in the presence of flupirtine. Kv7 currents in both guinea pig and human ASMCs were inhibited by the Kv7 channel blocker XE991. In human lung slices, XE991 induced robust airway constriction, which was completely reversed by addition of the calcium channel blocker verapamil. These findings suggest that Kv7 channels in ASMCs play an essential role in the regulation of airway diameter and may be targeted pharmacologically to relieve airway hyperconstriction induced by elevated concentrations of bronchoconstrictor agonists. PMID:21964407

  4. CXCL8 histone H3 acetylation is dysfunctional in airway smooth muscle in asthma: regulation by BET

    PubMed Central

    Clifford, Rachel L.; Patel, Jamie K.; John, Alison E.; Tatler, Amanda L.; Mazengarb, Lisa; Brightling, Christopher E.

    2015-01-01

    Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation. PMID:25713319

  5. Vitamin D deficiency causes airway hyperresponsiveness, increases airway smooth muscle mass, and reduces TGF‐β expression in the lungs of female BALB/c mice

    PubMed Central

    Foong, Rachel E.; Shaw, Nicole C.; Berry, Luke J.; Hart, Prue H.; Gorman, Shelley; Zosky, Graeme R.

    2014-01-01

    Abstract Vitamin D deficiency is associated with disease severity in asthma. We tested whether there is a causal association between vitamin D deficiency, airway smooth muscle (ASM) mass, and the development of airway hyperresponsiveness (AHR). A physiologically relevant mouse model of vitamin D deficiency was developed by raising BALB/c mice on vitamin D‐deficient or ‐replete diets. AHR was assessed by measuring lung function responses to increasing doses of inhaled methacholine. Five‐micron sections from formalin‐fixed lungs were used for ASM measurement and assessment of lung structure using stereological methods. Transforming growth factor (TGF)‐β levels were measured in bronchoalveolar lavage fluid (BALF). Lungs were dissected from embryonic day (E) 17.5 vitamin D‐deficient and ‐replete fetal mice for quantification of ASM density and relative gene expression of TGF‐β signaling pathway molecules. Eight‐week‐old adult vitamin D‐deficient female mice had significantly increased airway resistance and ASM in the large airways compared with controls. Vitamin D‐deficient female mice had a smaller lung volume, volume of parenchyma, and alveolar septa. Both vitamin D‐deficient male and female mice had reduced TGF‐β levels in BALF. Vitamin D deficiency did not have an effect on ASM density in E17.5 mice, however, expression of TGF‐β1 and TGF‐β receptor I was downregulated in vitamin D‐deficient female fetal mice. Decreased expression of TGF‐β1 and TGF‐β receptor I during early lung development in vitamin D‐deficient mice may contribute to airway remodeling and AHR in vitamin D‐deficient adult female mice. This study provides a link between vitamin D deficiency and respiratory symptoms in chronic lung disease. PMID:24760528

  6. IgE induces proliferation in human airway smooth muscle cells: role of MAPK and STAT3 pathways.

    PubMed

    Redhu, Naresh Singh; Shan, Lianyu; Al-Subait, Duaa; Ashdown, Heather L; Movassagh, Hesam; Lamkhioued, Bouchaib; Gounni, Abdelilah S

    2013-01-01

    Airway remodeling is not specifically targeted by current asthma medications, partly owing to the lack of understanding of remodeling mechanisms, altogether posing great challenges in asthma treatment. Increased airway smooth muscle (ASM) mass due to hyperplasia/hypertrophy contributes significantly to overall airway remodeling and correlates with decline in lung function. Recent evidence suggests that IgE sensitization can enhance the survival and mediator release in inflammatory cells. Human ASM (HASM) cells express both low affinity (FcεRII/CD23) and high affinity IgE Fc receptors (FcεRI), and IgE can modulate the contractile and synthetic function of HASM cells. IgE was recently shown to induce HASM cell proliferation but the detailed mechanisms remain unknown. We report here that IgE sensitization induces HASM cell proliferation, as measured by 3H-thymidine, EdU incorporation, and manual cell counting. As an upstream signature component of FcεRI signaling, inhibition of spleen tyrosine kinase (Syk) abrogated the IgE-induced HASM proliferation. Further analysis of IgE-induced signaling depicted an IgE-mediated activation of Erk 1/2, p38, JNK MAPK, and Akt kinases. Lastly, lentiviral-shRNA-mediated STAT3 silencing completely abolished the IgE-mediated HASM cell proliferation. Collectively, our data provide mechanisms of a novel function of IgE which may contribute, at least in part, to airway remodeling observed in allergic asthma by directly inducing HASM cell proliferation. PMID:24499258

  7. [Role of bronchodilators in therapy for COPD-mechanisms of LABA and LAMA on airway smooth muscle].

    PubMed

    Kume, Hiroaki

    2016-05-01

    Long-acting β2-adrenergic receptor agonists (LABAs) and anticholinergics (LAMAs) are widely used clinically as therpy for COPD. Clinical reports have demonstrated that LABAs (salmeterol, formoterol, indacaterol, olodaterol, vilanterol) and LAMAs (tiotropium, glycopyrronium, umeclidinium, aclidinium) are useful to improving symptoms and lung function, and to reducing exacerbation and hospitarization. LABAs expect salmeterol are strong partial agonists, and LAMAs are non-specific antagonists. Ca2+ dynamics and Ca2+ sensitization contribute to relaxation of airway smooth muscle in these bronchodilators. LABAs act on orthosteric and allosteric sites on the β2-adrenergic receptors. In contrast, LAMAs act not only on orthosteric site on the muscarinic receptors, but also allosteric site on the β2-adrenergic receptors, leading to enhancing β2-adrenergic action. Allosteric GPCR modulation is involved in the synergistic effects between LABAs and LAMAs. PMID:27254952

  8. Vasoactive peptides upregulate mRNA expression and secretion of vascular endothelial growth factor in human airway smooth muscle cells.

    PubMed

    Alagappan, Vijay K T; Willems-Widyastuti, Anna; Seynhaeve, Ann L B; Garrelds, Ingrid M; ten Hagen, Timo L M; Saxena, Pramod R; Sharma, Hari S

    2007-01-01

    Airway remodeling and associated angiogenesis are documented features of asthma, of which the molecular mechanisms are not fully understood. Angiotensin (ANG)II and endothelin (ET)-1 are potent vasoconstricting circulatory hormones implicated in asthma. We investigated the effects of ANG II and ET-1 on human airway smooth muscle (ASM) cells proliferation and growth and examined the mRNA expression and release of the angiogenic peptide, vascular endothelial growth factor (VEGF). Serum deprived (48 h) human ASM cells were incubated with ANG II (100 nM) or ET-1 (10 nM) for 30 min, 1, 2, 4, 8, 16, and 24 h and the endogenous synthesis of VEGF was examined in relation to control cells receiving serum free culture medium. ET-1 induced time dependent DNA biosynthesis as determined by [3H]-thymidine incorporation assay. Using northern blot hybridization, we detected two mRNA species of 3.9 and 1.7 kb encoding VEGF in the cultured smooth muscle cells. Both ANG II and ET-1 induced the mRNA expression (two- to threefold) and secretion (1.8- to 2.8-fold) of VEGF reaching maximal levels between 4-8 h of incubation. Induced expression and release of VEGF declined after 8 h of ANG II incubation while levels remained elevated in the case of ET-1. The conditioned medium derived from ET-1-treated ASM cells induced [3H]-thymidine incorporation and cell number in porcine pulmonary artery endothelial as well as human umbilical vein endothelial cells. Moreover, the VEGF tyrosine kinase receptor inhibitor blocked the conditioned medium induced mitogenesis in endothelial cells. Our results suggest a potential role for ANG II and ET-1 in ASM cell growth and upregulation of VEGF that may participate in endothelial cell proliferation via paracrine mechanisms and thus causing pathological angiogenesis and vascular remodelling seen during asthma. PMID:17406064

  9. Selective visualisation of sensory receptors in the smooth muscle layer of ex-vivo airway whole-mounts by styryl pyridinium dyes.

    PubMed

    De Proost, Ian; Pintelon, Isabel; Brouns, Inge; Timmermans, Jean-Pierre; Adriaensen, Dirk

    2007-09-01

    Recently, we established the location, morphology and neurochemical coding of vagal smooth-muscle-associated airway receptors (SMARs) in rat lungs. These receptors were characterised as branching laminar terminals that originated from myelinated nerve fibres and were intercalated between airway smooth-muscle bundles. To allow the direct physiological examination of these receptors, the present investigation aimed at visualising SMARs in airway whole-mounts of rat and mouse lungs ex vivo. Short incubation with various styryl pyridinium dyes (AM1-43, FM2-10, FM4-64 or 4-Di-2-ASP) gave a highly selective fluorescent visualisation of both laminar nerve terminals and myelinated fibres from which they originated throughout the intrapulmonary airway tree in mouse and in rat. The reliable and specific labelling of SMARs ex vivo with these lipophilic membrane dyes was confirmed via immunostaining for protein gene-product 9.5 and vesicular glutamate transporters. Similar to the intrapulmonary location of NEBs, these SMARs appeared to be even more explicitly located near airway bifurcations. Both the trachealis muscle and the smooth-muscle bundles of extrapulmonary bronchi were also shown to contain laminar nerve terminals that were morphologically similar to the SMARs reported in the intrapulmonary airways. Thus, this study provides an in-vitro model enabling, for the first time, the fast and reliable visualisation of SMARs and the myelinated nerve fibres from which they originate in airway whole-mount preparations ex vivo. As such, this model opens up further perspectives and creates a valid basis for direct physiological measurement and manipulation of the individually identified airway receptors. PMID:17522895

  10. Abnormal Histone Methylation is Responsible for Increased VEGF165a Secretion from Airway Smooth Muscle Cells in Asthma

    PubMed Central

    Clifford, Rachel L.; John, Alison E.; Brightling, Christopher E.; Knox, Alan J.

    2012-01-01

    Vascular Endothelial Growth Factor (VEGF), a key angiogenic molecule, is aberrantly expressed in several diseases including asthma where it contributes to bronchial vascular remodelling and chronic inflammation. Asthmatic human airway smooth muscle (HASM) cells hypersecrete VEGF but the mechanism is unclear. Here we defined the mechanism in HASM cells from non-asthmatic (NA) and asthmatic (A) patients. We found that asthmatic cells lacked a repression complex at the VEGF promoter which was present in non-asthmatic cells. Recruitment of G9A, trimethylation of histone H3 at lysine 9 (H3K9me3) and a resultant decrease in RNA polymerase II (RNA pol II) at the VEGF promoter was critical to repression of VEGF secretion in non-asthmatic cells. At the asthmatic promoter H3K9me3 was absent due to failed recruitment of G9a; RNA pol II binding, in association with TAF1, was increased, H3K4me3 was present and Sp1 binding was exaggerated and sustained. In contrast DNA methylation and histone acetylation were similar in A and NA cells. This is the first study to show that airway cells in asthma have altered epigenetic regulation of remodelling gene(s). Histone methylation at genes such as VEGF may be an important new therapeutic target. PMID:22689881

  11. Effects of age on muscarinic agonist-induced contraction an IP accumulation in airway smooth muscle

    SciTech Connect

    Wills-Karp, M. )

    1991-01-01

    The effects of age on carbachol-stimulated force development and ({sup 3}H)inositol phosphate production was studied in tracheal rings from guinea pigs aged 1 month and 25 months of age. The pD{sub 2} for the contractile response to carbachol was significantly reduced in tracheal tissues from old animals as compared to that of the young tissues, respectively. In contrast, inositol phosphate formation was not altered with increasing age when stimulated by carbachol or NaF, a direct activator of G proteins. Carbachol-induced inositol phosphate accumulation was inhibited by treatment with 1{mu}g/ml pertussis toxin, suggesting that IP1 accumulation is coupled to a pertussis-toxin-sensitive protein. The pD{sub 2} values for contraction were significantly different from the pD{sub 2} values for IP1 accumulation, in both young and old tissues, respectively. These data suggest that IP1 accumulation is not responsible for the decreased contractile ability in tracheal smooth muscle during aging.

  12. Oxidative stress–induced mitochondrial dysfunction drives inflammation and airway smooth muscle remodeling in patients with chronic obstructive pulmonary disease

    PubMed Central

    Wiegman, Coen H.; Michaeloudes, Charalambos; Haji, Gulammehdi; Narang, Priyanka; Clarke, Colin J.; Russell, Kirsty E.; Bao, Wuping; Pavlidis, Stelios; Barnes, Peter J.; Kanerva, Justin; Bittner, Anton; Rao, Navin; Murphy, Michael P.; Kirkham, Paul A.; Chung, Kian Fan; Adcock, Ian M.; Brightling, Christopher E.; Davies, Donna E.; Finch, Donna K.; Fisher, Andrew J.; Gaw, Alasdair; Knox, Alan J.; Mayer, Ruth J.; Polkey, Michael; Salmon, Michael; Singh, David

    2015-01-01

    Background Inflammation and oxidative stress play critical roles in patients with chronic obstructive pulmonary disease (COPD). Mitochondrial oxidative stress might be involved in driving the oxidative stress–induced pathology. Objective We sought to determine the effects of oxidative stress on mitochondrial function in the pathophysiology of airway inflammation in ozone-exposed mice and human airway smooth muscle (ASM) cells. Methods Mice were exposed to ozone, and lung inflammation, airway hyperresponsiveness (AHR), and mitochondrial function were determined. Human ASM cells were isolated from bronchial biopsy specimens from healthy subjects, smokers, and patients with COPD. Inflammation and mitochondrial function in mice and human ASM cells were measured with and without the presence of the mitochondria-targeted antioxidant MitoQ. Results Mice exposed to ozone, a source of oxidative stress, had lung inflammation and AHR associated with mitochondrial dysfunction and reflected by decreased mitochondrial membrane potential (ΔΨm), increased mitochondrial oxidative stress, and reduced mitochondrial complex I, III, and V expression. Reversal of mitochondrial dysfunction by the mitochondria-targeted antioxidant MitoQ reduced inflammation and AHR. ASM cells from patients with COPD have reduced ΔΨm, adenosine triphosphate content, complex expression, basal and maximum respiration levels, and respiratory reserve capacity compared with those from healthy control subjects, whereas mitochondrial reactive oxygen species (ROS) levels were increased. Healthy smokers were intermediate between healthy nonsmokers and patients with COPD. Hydrogen peroxide induced mitochondrial dysfunction in ASM cells from healthy subjects. MitoQ and Tiron inhibited TGF-β–induced ASM cell proliferation and CXCL8 release. Conclusions Mitochondrial dysfunction in patients with COPD is associated with excessive mitochondrial ROS levels, which contribute to enhanced inflammation and cell

  13. L-thyroxine promotes a proliferative airway smooth muscle phenotype in the presence of TGF-β1.

    PubMed

    Dekkers, Bart G J; Naeimi, Saeideh; Bos, I Sophie T; Menzen, Mark H; Halayko, Andrew J; Hashjin, Goudarz Sadeghi; Meurs, Herman

    2015-02-01

    Hypothyroidism may reduce, whereas hyperthyroidism may aggravate, asthma symptoms. The mechanisms underlying this relationship are largely unknown. Since thyroid hormones have central roles in cell growth and differentiation, we hypothesized that airway remodeling, in particular increased airway smooth muscle (ASM) mass, may be involved. To address this hypothesis, we investigated the effects of triiodothyronine (T3) and l-thyroxine (T4) in the absence and presence of the profibrotic transforming growth factor (TGF)-β1 on human ASM cell phenotype switching. T3 (1-100 nM) and T4 (1-100 nM) did not affect basal ASM proliferation. However, when combined with TGF-β1 (2 ng/ml), T4 synergistically increased the proliferative response, whereas only a minor effect was observed for T3. In line with a switch from a contractile to a proliferative ASM phenotype, T4 reduced the TGF-β1-induced contractile protein expression by ∼50%. Cotreatment with T3 reduced TGF-β1-induced contractile protein expression by ∼25%. The synergistic increase in proliferation was almost fully inhibited by the integrin αvβ3 antagonist tetrac (100 nM), whereas no significant effects of the thyroid receptor antagonist 1-850 (3 μM) were observed. Inhibition of MEK1/2, downstream of the integrin αvβ3, also inhibited the T4- and TGF-β1-induced proliferative responses. Collectively, the results indicate that T4, and to a lesser extent T3, promotes a proliferative ASM phenotype in the presence of TGF-β1, which is predominantly mediated by the membrane-bound T4 receptor αvβ3. These results indicate that thyroid hormones may enhance ASM remodeling in asthma, which could be of relevance for hyperthyroid patients with this disease. PMID:25480330

  14. BET Bromodomains Regulate Transforming Growth Factor-β-induced Proliferation and Cytokine Release in Asthmatic Airway Smooth Muscle*

    PubMed Central

    Perry, Mark M.; Durham, Andrew L.; Austin, Philip J.; Adcock, Ian M.; Chung, Kian Fan

    2015-01-01

    Airway smooth muscle (ASM) mass is increased in asthma, and ASM cells from patients with asthma are hyperproliferative and release more IL-6 and CXCL8. The BET (bromo- and extra-terminal) family of proteins (Brd2, Brd3, and Brd4) govern the assembly of histone acetylation-dependent chromatin complexes. We have examined whether they modulate proliferation and cytokine expression in asthmatic ASM cells by studying the effect of BET bromodomain mimics JQ1/SGCBD01 and I-BET762. ASM cells from healthy individuals and nonsevere and severe asthmatics were pretreated with JQ1/SGCBD01 and I-BET762 prior to stimulation with FCS and TGF-β. Proliferation was measured by BrdU incorporation. IL-6 and CXCL8 release was measured by ELISA, and mRNA expression was measured by quantitative RT-PCR. ChIP using a specific anti-Brd4 antibody and PCR primers directed against the transcriptional start site of IL-6 and CXCL8 gene promoters was performed. Neither JQ1/SGCBD01 nor I-BET762 had any effect on ASM cell viability. JQ1/SGCBD01 and I-BET762 inhibited FCS+TGF-β-induced ASM cell proliferation and IL-6 and CXCL8 release in healthy individuals (≥ 30 nm) and in nonsevere and severe asthma patients (≥100 nm), with the latter requiring higher concentrations of these mimics. JQ1/SGCBD01 reduced Brd4 binding to IL8 and IL6 promoters induced by FCS+TGF-β. Mimics of BET bromodomains inhibit aberrant ASM cell proliferation and inflammation with lesser efficiency in those from asthmatic patients. They may be effective in reducing airway remodeling in asthma. PMID:25697361

  15. A new nitrosyl ruthenium complex nitric oxide donor presents higher efficacy than sodium nitroprusside on relaxation of airway smooth muscle.

    PubMed

    Castro, Patrícia F S; Pereira, Amanda de C; Rogrigues, Gerson J; Batista, Aline C; da Silva, Roberto S; Bendhack, Lusiane M; Rocha, Matheus L

    2011-08-17

    Nitric oxide (NO) has been demonstrated to be the primary agent in relaxing airways in humans and animals. We investigated the mechanisms involved in the relaxation induced by NO-donors, ruthenium complex [Ru(terpy)(bdq)NO(+)](3+) (TERPY) and sodium nitroprusside (SNP) in isolated trachea of rats contracted with carbachol in an isolated organs chamber. For instance, we verified the contribution of K(+) channels, the importance of sGC/cGMP pathway, the influence of the extra and intracellular Ca(2+) sources and the contribution of the epithelium on the relaxing response. Additionally, we have used confocal microscopy in order to analyze the action of the NO-donors on cytosolic Ca(2+) concentration. The results demonstrated that both compounds led to the relaxation of trachea in a dependent-concentration way. However, the maximum effect (E(max)) of TERPY is higher than the SNP. The relaxation induced by SNP (but not TERPY) was significantly reduced by pretreatment with ODQ (sGC inhibitor). Only TERPY-induced relaxation was reduced by tetraethylammonium (K(+) channels blocker) and by pre-contraction with 75mM KCl (membrane depolarization). The response to both NO-donors was not altered by the presence of thapsigargin (sarcoplasmic reticulum Ca(2+)-ATPase inhibitor). The epithelium removal has reduced the relaxation only to SNP, and it has no effect on TERPY. The both NO-donors reduced the contraction evoked by Ca(2+) influx, while TERPY have shown a higher inhibitory effect on contraction. Moreover, the TERPY was more effective than SNP in reducing the cytosolic Ca(2+) concentration measured by confocal microscopy. In conclusion, these results show that TERPY induces airway smooth muscle relaxation by cGMP-independent mechanisms, it involves the fluxes of Ca(2+) and K(+) across the membrane, it is more effective in reducing cytosolic Ca(2+) concentration and inducing relaxation in the rat trachea than the standard drug, SNP. PMID:21605670

  16. The Role of Inflammation Resolution Speed in Airway Smooth Muscle Mass Accumulation in Asthma: Insight from a Theoretical Model

    PubMed Central

    Chernyavsky, Igor L.; Croisier, Huguette; Chapman, Lloyd A. C.; Kimpton, Laura S.; Hiorns, Jonathan E.; Brook, Bindi S.; Jensen, Oliver E.; Billington, Charlotte K.; Hall, Ian P.; Johnson, Simon R.

    2014-01-01

    Despite a large amount of in vitro data, the dynamics of airway smooth muscle (ASM) mass increase in the airways of patients with asthma is not well understood. Here, we present a novel mathematical model that describes qualitatively the growth dynamics of ASM cells over short and long terms in the normal and inflammatory environments typically observed in asthma. The degree of ASM accumulation can be explained by an increase in the rate at which ASM cells switch between non-proliferative and proliferative states, driven by episodic inflammatory events. Our model explores the idea that remodelling due to ASM hyperplasia increases with the frequency and magnitude of these inflammatory events, relative to certain sensitivity thresholds. It highlights the importance of inflammation resolution speed by showing that when resolution is slow, even a series of small exacerbation events can result in significant remodelling, which persists after the inflammatory episodes. In addition, we demonstrate how the uncertainty in long-term outcome may be quantified and used to design an optimal low-risk individual anti-proliferative treatment strategy. The model shows that the rate of clearance of ASM proliferation and recruitment factors after an acute inflammatory event is a potentially important, and hitherto unrecognised, target for anti-remodelling therapy in asthma. It also suggests new ways of quantifying inflammation severity that could improve prediction of the extent of ASM accumulation. This ASM growth model should prove useful for designing new experiments or as a building block of more detailed multi-cellular tissue-level models. PMID:24632688

  17. A mannose receptor mediates mannosyl-rich glycoprotein-induced mitogenesis in bovine airway smooth muscle cells.

    PubMed Central

    Lew, D B; Songu-Mize, E; Pontow, S E; Stahl, P D; Rattazzi, M C

    1994-01-01

    The putative mannose receptor (MR), previously implicated in mannosyl-rich glycoprotein-induced mitogenesis in bovine airway smooth muscle (ASM) cells, was studied to determine its properties. Specific binding of the mitogenic neoglycoprotein, mannosylated bovine serum albumin (Man-BSA) to ASM cells was saturable, with an apparent Kd = 5.0 x 10(-8) M. Cell-bound ManBSA-colloidal gold conjugate was localized by electron microscopy to clathrin-coated pits on the cell surface, and was found to undergo internalization to endosomes; this was inhibitable by weak bases and swainsonine, that also inhibited ligand-induced mitogenesis. The ASM-MR, isolated by mannose-affinity chromatography, had the same apparent molecular mass as the macrophage (Mø) MR (M(r) = 175 kD), and was immunoprecipitated by an anti-MøMR immune serum. This antiserum blocked 125I-labeled-ManBSA binding to intact ASM cells, stimulated mitogenesis, and immunolocalized the ASM-MR in cytoplasmic vesicles compatible with endosomes. A monoclonal antibody directed against the MøMR also reacted with the ASM-MR; like the polyclonal antibodies, it stimulated mitogenesis as effectively as beta-hexosaminidases. These data indicate that the ASM-MR shares a number of functional and structural properties with the MøMR and suggest that similar receptors may have different main functions in different cells. Images PMID:7962531

  18. Nanotubes connect CD4+ T cells to airway smooth muscle cells: novel mechanism of T cell survival.

    PubMed

    Al Heialy, Saba; Zeroual, Melissa; Farahnak, Soroor; McGovern, Toby; Risse, Paul-André; Novali, Mauro; Lauzon, Anne-Marie; Roman, Horia N; Martin, James G

    2015-06-15

    Contact between airway smooth muscle (ASM) cells and activated CD4(+) T cells, a key interaction in diseases such as asthma, triggers ASM cell proliferation and enhances T cell survival. We hypothesized that direct contact between ASM and CD4(+) T cells facilitated the transfer of anti-apoptotic proteins via nanotubes, resulting in increased survival of activated CD4(+) T cells. CD4(+) T cells, isolated from PBMCs of healthy subjects, when activated and cocultured with ASM cells for 24 h, formed nanotubes that were visualized by immunofluorescence and atomic force microscopy. Cell-to-cell transfer of the fluorescent dye calcein-AM confirmed cytoplasmic communication via nanotubes. Immunoreactive B cell lymphoma 2 (Bcl-2) and induced myeloid leukemia cell differentiation protein (Mcl-1), two major anti-apoptotic proteins, were present within the nanotubes. Downregulation of Mcl-1 by small interfering RNA in ASM cells significantly increased T cell apoptosis, whereas downregulation of Bcl-2 had no effect. Transfer of GFP-tagged Mcl-1 from ASM cells to CD4(+) T cells via the nanotubes confirmed directionality of transfer. In conclusion, activated T cells communicate with ASM cells via nanotube formation. Direct transfer of Mcl-1 from ASM to CD(+) T cells via nanotubes is involved in T cell survival. This study provides a novel mechanism of survival of CD4(+) T cells that is dependent on interaction with a structural cell. PMID:25934863

  19. Selective targeting of the α5-subunit of GABAA receptors relaxes airway smooth muscle and inhibits cellular calcium handling

    PubMed Central

    Yocum, Gene T.; Siviski, Matthew E.; Yim, Peter D.; Fu, Xiao Wen; Poe, Michael M.; Cook, James M.; Harrison, Neil; Perez-Zoghbi, Jose; Emala, Charles W.

    2015-01-01

    The clinical need for novel bronchodilators for the treatment of bronchoconstrictive diseases remains a major medical issue. Modulation of airway smooth muscle (ASM) chloride via GABAA receptor activation to achieve relaxation of precontracted ASM represents a potentially beneficial therapeutic option. Since human ASM GABAA receptors express only the α4- and α5-subunits, there is an opportunity to selectively target ASM GABAA receptors to improve drug efficacy and minimize side effects. Recently, a novel compound (R)-ethyl8-ethynyl-6-(2-fluorophenyl)-4-methyl-4H-benzo[f]imidazo[1,5-a][1,4] diazepine-3-carboxylate (SH-053-2′F-R-CH3) with allosteric selectivity for α5-subunit containing GABAA receptors has become available. We questioned whether this novel GABAA α5-selective ligand relaxes ASM and affects intracellular calcium concentration ([Ca2+]i) regulation. Immunohistochemical staining localized the GABAA α5-subunit to human ASM. The selective GABAA α5 ligand SH-053-2′F-R-CH3 relaxes precontracted intact ASM; increases GABA-activated chloride currents in human ASM cells in voltage-clamp electrophysiology studies; and attenuates bradykinin-induced increases in [Ca2+]i, store-operated Ca2+ entry, and methacholine-induced Ca2+ oscillations in peripheral murine lung slices. In conclusion, selective subunit targeting of endogenous α5-subunit containing GABAA receptors on ASM may represent a novel therapeutic option to treat severe bronchospasm. PMID:25659897

  20. Selective targeting of the α5-subunit of GABAA receptors relaxes airway smooth muscle and inhibits cellular calcium handling.

    PubMed

    Gallos, George; Yocum, Gene T; Siviski, Matthew E; Yim, Peter D; Fu, Xiao Wen; Poe, Michael M; Cook, James M; Harrison, Neil; Perez-Zoghbi, Jose; Emala, Charles W

    2015-05-01

    The clinical need for novel bronchodilators for the treatment of bronchoconstrictive diseases remains a major medical issue. Modulation of airway smooth muscle (ASM) chloride via GABAA receptor activation to achieve relaxation of precontracted ASM represents a potentially beneficial therapeutic option. Since human ASM GABAA receptors express only the α4- and α5-subunits, there is an opportunity to selectively target ASM GABAA receptors to improve drug efficacy and minimize side effects. Recently, a novel compound (R)-ethyl8-ethynyl-6-(2-fluorophenyl)-4-methyl-4H-benzo[f]imidazo[1,5-a][1,4] diazepine-3-carboxylate (SH-053-2'F-R-CH3) with allosteric selectivity for α5-subunit containing GABAA receptors has become available. We questioned whether this novel GABAA α5-selective ligand relaxes ASM and affects intracellular calcium concentration ([Ca(2+)]i) regulation. Immunohistochemical staining localized the GABAA α5-subunit to human ASM. The selective GABAA α5 ligand SH-053-2'F-R-CH3 relaxes precontracted intact ASM; increases GABA-activated chloride currents in human ASM cells in voltage-clamp electrophysiology studies; and attenuates bradykinin-induced increases in [Ca(2+)]i, store-operated Ca(2+) entry, and methacholine-induced Ca(2+) oscillations in peripheral murine lung slices. In conclusion, selective subunit targeting of endogenous α5-subunit containing GABAA receptors on ASM may represent a novel therapeutic option to treat severe bronchospasm. PMID:25659897

  1. Parabronchial smooth muscle constitutes an airway epithelial stem cell niche in the mouse lung after injury.

    PubMed

    Volckaert, Thomas; Dill, Erik; Campbell, Alice; Tiozzo, Caterina; Majka, Susan; Bellusci, Saverio; De Langhe, Stijn P

    2011-11-01

    During lung development, parabronchial SMC (PSMC) progenitors in the distal mesenchyme secrete fibroblast growth factor 10 (Fgf10), which acts on distal epithelial progenitors to promote their proliferation. β-catenin signaling within PSMC progenitors is essential for their maintenance, proliferation, and expression of Fgf10. Here, we report that this Wnt/Fgf10 embryonic signaling cascade is reactivated in mature PSMCs after naphthalene-induced injury to airway epithelium. Furthermore, we found that this paracrine Fgf10 action was essential for activating surviving variant Clara cells (the cells in the airway epithelium from which replacement epithelial cells originate) located at the bronchoalveolar duct junctions and adjacent to neuroendocrine bodies. After naphthalene injury, PSMCs secreted Fgf10 to activate Notch signaling and induce Snai1 expression in surviving variant Clara cells, which subsequently underwent a transient epithelial to mesenchymal transition to initiate the repair process. Epithelial Snai1 expression was important for regeneration after injury. We have therefore identified PSMCs as a stem cell niche for the variant Clara cells in the lung and established that paracrine Fgf10 signaling from the niche is critical for epithelial repair after naphthalene injury. These findings also have implications for understanding the misregulation of lung repair in asthma and cancer. PMID:21985786

  2. A New Approach for the Study of Lung Smooth Muscle Phenotypes and Its Application in a Murine Model of Allergic Airway Inflammation

    PubMed Central

    Paez-Cortez, Jesus; Krishnan, Ramaswamy; Arno, Anneliese; Aven, Linh; Ram-Mohan, Sumati; Patel, Kruti R.; Lu, Jining; King, Oliver D.; Ai, Xingbin; Fine, Alan

    2013-01-01

    Phenotypes of lung smooth muscle cells in health and disease are poorly characterized. This is due, in part, to a lack of methodologies that allow for the independent and direct isolation of bronchial smooth muscle cells (BSMCs) and vascular smooth muscle cells (VSMCs) from the lung. In this paper, we describe the development of a bi-fluorescent mouse that permits purification of these two cell populations by cell sorting. By subjecting this mouse to an acute allergen based-model of airway inflammation that exhibits many features of asthma, we utilized this tool to characterize the phenotype of so-called asthmatic BSMCs. First, we examined the biophysical properties of single BSMCs from allergen sensitized mice and found increases in basal tone and cell size that were sustained ex vivo. We then generated for the first time, a comprehensive characterization of the global gene expression changes in BSMCs isolated from the bi-fluorescent mice with allergic airway inflammation. Using statistical methods and pathway analysis, we identified a number of differentially expressed mRNAs in BSMCs from allergen sensitized mice that code for key candidate proteins underlying changes in matrix formation, contractility, and immune responses. Ultimately, this tool will provide direction and guidance for the logical development of new markers and approaches for studying human lung smooth muscle. PMID:24040256

  3. Comparative Study of Protective Effects of Salbutamol and Beclomethasone against Insulin Induced Airway Hyper-reactivity on Isolated Tracheal Smooth Muscle of Guinea Pig

    PubMed Central

    Sharif, Mahjabeen; Tayyaba Khan, Bushra; Bakhtiar, Salman; Anwar, Mohammad Asim

    2015-01-01

    Inhalational insulin was withdrawn from the market due to its potential to produce airway hyper-reactivity and bronchoconstriction. So the present study was designed to explore the acute effects of insulin on airway reactivity of guinea pigs and protective effects of salbutamol and beclomethasone against insulin induced airway hyper-responsiveness on isolated tracheal smooth muscle of guinea pig. Effects of varying concentrations of insulin (10-7 to 10-3 M), insulin pretreated with fixed concentration of salbutamol (10-7 M) and beclomethasone (10-6 M) were studied on isolated tracheal tissue of guinea pig by constructing cumulative concentration response curves. Changes in tracheal smooth muscle contractions were recorded on four channel oscillograph. The mean ± SEM of maximum amplitudes of contraction with increasing concentrations of insulin, insulin pretreated with fixed concentration of salbutamol and beclomethasone were 35 ± 1.13 mm, 14.55 ± 0.62 mm and 22 ± 1.154 mm respectively. Although salbutamol and beclomethasone both had a profound inhibitory effect on insulin induced airway hyper-reactivity, yet salbutamol is more efficacious than beclomethasone. So we suggest that pretreatment of inhaled insulin with salbutamol may be preferred over beclomethasone in amelioration of its potential respiratory adverse effects such as bronchoconstriction. PMID:25901165

  4. Bronchodilator and anti-inflammatory activities of glaucine: In vitro studies in human airway smooth muscle and polymorphonuclear leukocytes.

    PubMed

    Cortijo, J; Villagrasa, V; Pons, R; Berto, L; Martí-Cabrera, M; Martinez-Losa, M; Domenech, T; Beleta, J; Morcillo, E J

    1999-08-01

    1. Selective phosphodiesterase 4 (PDE4) inhibitors are of potential interest in the treatment of asthma. We examined the effects of the alkaloid S-(+)-glaucine, a PDE4 inhibitor, on human isolated bronchus and granulocyte function. 2. Glaucine selectively inhibited PDE4 from human bronchus and polymorphonuclear leukocytes (PMN) in a non-competitive manner (Ki=3.4 microM). Glaucine displaced [3H]-rolipram from its high-affinity binding sites in rat brain cortex membranes (IC50 approximately 100 microM). 3. Glaucine inhibited the spontaneous and histamine-induced tone in human isolated bronchus (pD2 approximately 4.5). Glaucine (10 microM) did not potentiate the isoprenaline-induced relaxation but augmented cyclic AMP accumulation by isoprenaline. The glaucine-induced relaxation was resistant to H-89, a protein kinase A inhibitor. Glaucine depressed the contractile responses to Ca2+ (pD'2 approximately 3.62) and reduced the sustained rise of [Ca2+]i produced by histamine in cultured human airway smooth muscle cells (-log IC50 approximately 4.3). 4. Glaucine augmented cyclic AMP levels in human polymorphonuclear leukocytes challenged with N-formyl-Met-Leu-Phe (FMLP) or isoprenaline, and inhibited FMLP-induced superoxide generation, elastase release, leukotriene B4 production, [Ca2+]i signal and platelet aggregation as well as opsonized zymosan-, phorbol myristate acetate-, and A23187-induced superoxide release. The inhibitory effect of glaucine on superoxide generation by FMLP was reduced by H-89. 5. In conclusion, Ca2+ channel antagonism by glaucine appears mainly responsible for the relaxant effect of glaucine in human isolated bronchus while PDE4 inhibition contributes to the inhibitory effects of glaucine in human granulocytes. The very low PDE4/binding site ratio found for glaucine makes this compound attractive for further structure-activity studies. PMID:10455321

  5. Bronchodilator and anti-inflammatory activities of glaucine: In vitro studies in human airway smooth muscle and polymorphonuclear leukocytes

    PubMed Central

    Cortijo, J; Villagrasa, V; Pons, R; Berto, L; Martí-Cabrera, M; Martinez-Losa, M; Domenech, T; Beleta, J; Morcillo, E J

    1999-01-01

    Selective phosphodiesterase 4 (PDE4) inhibitors are of potential interest in the treatment of asthma. We examined the effects of the alkaloid S-(+)-glaucine, a PDE4 inhibitor, on human isolated bronchus and granulocyte function.Glaucine selectively inhibited PDE4 from human bronchus and polymorphonuclear leukocytes (PMN) in a non-competitive manner (Ki=3.4 μM). Glaucine displaced [3H]-rolipram from its high-affinity binding sites in rat brain cortex membranes (IC50∼100 μM).Glaucine inhibited the spontaneous and histamine-induced tone in human isolated bronchus (pD2∼4.5). Glaucine (10 μM) did not potentiate the isoprenaline-induced relaxation but augmented cyclic AMP accumulation by isoprenaline. The glaucine-induced relaxation was resistant to H-89, a protein kinase A inhibitor. Glaucine depressed the contractile responses to Ca2+ (pD'2∼3.62) and reduced the sustained rise of [Ca2+]i produced by histamine in cultured human airway smooth muscle cells (−log IC50∼4.3).Glaucine augmented cyclic AMP levels in human polymorphonuclear leukocytes challenged with N-formyl-Met-Leu-Phe (FMLP) or isoprenaline, and inhibited FMLP-induced superoxide generation, elastase release, leukotriene B4 production, [Ca2+]i signal and platelet aggregation as well as opsonized zymosan-, phorbol myristate acetate-, and A23187-induced superoxide release. The inhibitory effect of glaucine on superoxide generation by FMLP was reduced by H-89.In conclusion, Ca2+ channel antagonism by glaucine appears mainly responsible for the relaxant effect of glaucine in human isolated bronchus while PDE4 inhibition contributes to the inhibitory effects of glaucine in human granulocytes. The very low PDE4/binding site ratio found for glaucine makes this compound attractive for further structure-activity studies. PMID:10455321

  6. Targeting the γ-Aminobutyric Acid A Receptor α4 Subunit in Airway Smooth Muscle to Alleviate Bronchoconstriction.

    PubMed

    Yocum, Gene T; Gallos, George; Zhang, Yi; Jahan, Rajwana; Stephen, Michael Rajesh; Varagic, Zdravko; Puthenkalam, Roshan; Ernst, Margot; Cook, James M; Emala, Charles W

    2016-04-01

    We previously demonstrated that airway smooth muscle (ASM) cells express γ-aminobutyric acid A receptors (GABAARs), and that GABAAR agonists acutely relax ASM. Among the GABAAR α subunits, human ASM cells express only α4 and α5, providing the opportunity for selective pharmacologic targeting. Novel GABAAR-positive allosteric modulators designed for enhanced α4/α6 subunit selectivity were synthesized using iterative computational analyses (CMD-45 and XHe-III-74). Studies using oocyte heterologous expression systems confirmed that CMD-45 and XHe-III-74 led to significantly greater augmentation of currents induced by a 3% maximal effective concentration (EC3) of GABA [EC3]-induced currents in oocytes expressing α4 or α6 subunits (along with β3 and γ2) compared with other α subunits. CMD-45 and XHe-III-74 also led to greater ex vivo relaxation of contracted wild-type mouse tracheal rings compared with tracheal rings from GABAAR α4 subunit (Gabra4) knockout mice. Furthermore, CMD-45 and XHe-III-74 significantly relaxed precontracted human ASM ex vivo, and, at a low concentration, both ligands led to a significant leftward shift in albuterol-mediated ASM relaxation. In vivo, inhaled XHe-III-74 reduced respiratory system resistance in an asthmatic mouse model. Pretreatment of human ASM cells with CMD-45 and XHe-III-74 inhibited histamine-induced increases in intracellular calcium concentrations in vitro, an effect that was lost when calcium was omitted from the extracellular buffer, suggesting that inhibition of calcium influx due to alterations in plasma membrane potential may play a role in the mechanism of ASM relaxation. Selective targeting of the GABAAR α4 subunit with inhaled ligands may be a novel therapeutic pathway to treat bronchoconstriction, while avoiding sedative central nervous system effects, which are largely mediated by α1-3 subunit-containing GABAARs in the brain. PMID:26405827

  7. 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...

  8. T-bet is induced by interferon-γ to mediate chemokine secretion and migration in human airway smooth muscle cells

    PubMed Central

    2011-01-01

    An inappropriate balance between T-helper (Th)1 and Th2 cytokine production underlies inflammatory changes that result in airway disease. Expression of the T-box transcription factor T-bet regulates differentiation of Th cells and production of Th1 cytokines, particularly IFNγ. T-bet-deficient mice develop airway hyperreactivity, undergo airway remodeling, and exhibit defects in IFNγ production while overproducing Th2 cytokines. T-bet is also reduced in the airways of asthmatic patients, suggesting loss of T-bet expression or activity promotes development of inflammatory airway disease. We present novel data demonstrating T-bet expression is induced in human airway smooth muscle cells (ASMC) by IFNγ. This IFNγ-stimulated expression of T-bet is dependent on signaling through JAK2 and signal transducers and activators of transcription 1 (STAT1) and activates T-bet-dependent DNA binding activity. Expression of T-bet stimulates IFNγ-stimulated IFNγ expression, secretion, and promoter activity, while inhibiting IFNγ-stimulated release of chemokines including monocyte chemoattractant protein (MCP)-1/CCL2, regulated on activation normal T-expressed and secreted (RANTES)/CCL5, and eotaxin/CCL11. This is accompanied by changes in expression of the chemokine receptors CCR3 and IL12Rβ2 and TNFα. T-bet expression also reduces chemotactic migration of ASMC in response to serum and PDGF, which contributes to airway hyperplasia. These results are the first to identify T-bet expression and activity in a structural cell of the lung and may provide new insights into therapeutic targets for inflammatory airway disease. PMID:21239533

  9. Effect of the plant derivative Compound A on the production of corticosteroid-resistant chemokines in airway smooth muscle cells.

    PubMed

    Gavrila, Adelina; Chachi, Latifa; Tliba, Omar; Brightling, Christopher; Amrani, Yassine

    2015-11-01

    Preclinical models of human conditions including asthma showed the therapeutic potential of Compound A (CpdA), a dissociated glucocorticoid (GC) receptor (GRα) ligand. Whether CpdA inhibits GC resistance, a central feature of severe asthma, has not been addressed. We investigated whether CpdA modulates cytokine-induced GC resistance in human airway smooth muscle (ASM) cells. Healthy and asthmatic ASM cells were treated with TNF-α/IFN-γ for 24 hours in the presence or absence of CpdA. ELISA and quantitative PCR assays were used to assess the effect of CpdA on chemokine expression. Activation of GRα by CpdA was assessed by quantitative PCR, immunostaining, and receptor antagonism using RU486. An effect of CpdA on the transcription factor interferon regulatory factor 1 (IRF-1) was investigated using immunoblot, immunostaining, and small interfering RNA (siRNA) knockdown. CpdA inhibited production of fluticasone-resistant chemokines CCL5, CX3CL1, and CXCL10 at protein and mRNA levels in both asthmatic and healthy cells. CpdA failed to induce expression of GC-induced Leucine Zipper while transiently inducing mitogen-activated protein kinase phosphatase 1 (MKP-1) at both mRNA and protein levels. CpdA inhibitory action was not associated with GRα nuclear translocation, nor was it prevented by RU486 antagonism. Activation of IRF-1 by TNF-α/IFN-γ was inhibited by CpdA. IRF-1 siRNA knockdown reduced cytokine-induced CCL5 and CX3CL1 production. siRNA MKP-1 prevented the inhibitory effect of CpdA on cytokine-induced CXCL10 production. For the first time, we show that CpdA inhibits the production of GC-resistant chemokines via GRα-independent mechanisms involving the inhibition of IRF-1 and up-regulation of MKP-1. Thus, targeting CpdA-sensitive pathways in ASM cells represents an alternative therapeutic approach to treat GC resistance in asthma. PMID:25897650

  10. Extracellular acidification induces connective tissue growth factor production through proton-sensing receptor OGR1 in human airway smooth muscle cells

    SciTech Connect

    Matsuzaki, Shinichi; Ishizuka, Tamotsu; Yamada, Hidenori; Kamide, Yosuke; Hisada, Takeshi; Ichimonji, Isao; Aoki, Haruka; Yatomi, Masakiyo; Komachi, Mayumi; Tsurumaki, Hiroaki; Ono, Akihiro; Koga, Yasuhiko; Dobashi, Kunio; Mogi, Chihiro; Sato, Koichi; Tomura, Hideaki; Mori, Masatomo; Okajima, Fumikazu

    2011-10-07

    Highlights: {yields} The involvement of extracellular acidification in airway remodeling was investigated. {yields} Extracellular acidification alone induced CTGF production in human ASMCs. {yields} Extracellular acidification enhanced TGF-{beta}-induced CTGF production in human ASMCs. {yields} Proton-sensing receptor OGR1 was involved in acidic pH-stimulated CTGF production. {yields} OGR1 may play an important role in airway remodeling in asthma. -- Abstract: Asthma is characterized by airway inflammation, hyper-responsiveness and remodeling. Extracellular acidification is known to be associated with severe asthma; however, the role of extracellular acidification in airway remodeling remains elusive. In the present study, the effects of acidification on the expression of connective tissue growth factor (CTGF), a critical factor involved in the formation of extracellular matrix proteins and hence airway remodeling, were examined in human airway smooth muscle cells (ASMCs). Acidic pH alone induced a substantial production of CTGF, and enhanced transforming growth factor (TGF)-{beta}-induced CTGF mRNA and protein expression. The extracellular acidic pH-induced effects were inhibited by knockdown of a proton-sensing ovarian cancer G-protein-coupled receptor (OGR1) with its specific small interfering RNA and by addition of the G{sub q/11} protein-specific inhibitor, YM-254890, or the inositol-1,4,5-trisphosphate (IP{sub 3}) receptor antagonist, 2-APB. In conclusion, extracellular acidification induces CTGF production through the OGR1/G{sub q/11} protein and inositol-1,4,5-trisphosphate-induced Ca{sup 2+} mobilization in human ASMCs.

  11. Viscoelastic and dynamic nonlinear properties of airway smooth muscle tissue: roles of mechanical force and the cytoskeleton.

    PubMed

    Ito, Satoru; Majumdar, Arnab; Kume, Hiroaki; Shimokata, Kaoru; Naruse, Keiji; Lutchen, Kenneth R; Stamenovic, Dimitrije; Suki, Béla

    2006-06-01

    The viscoelastic and dynamic nonlinear properties of guinea pig tracheal smooth muscle tissues were investigated by measuring the storage (G') and loss (G") moduli using pseudorandom small-amplitude length oscillations between 0.12 and 3.5 Hz superimposed on static strains of either 10 or 20% of initial length. The G" and G' spectra were interpreted using a linear viscoelastic model incorporating damping (G) and stiffness (H), respectively. Both G and H were elevated following an increase in strain from 10 to 20%. There was no change in harmonic distortion (K(d)), an index of dynamic nonlinearity, between 10 and 20% strains. Application of methacholine at 10% strain significantly increased G and H while it decreased K(d). Cytochalasin D, isoproterenol, and HA-1077, a Rho-kinase inhibitor, significantly decreased both G and H but increased K(d). Following cytochalasin D, G, H, and K(d) were all elevated when mean strain increased from 10 to 20%. There were no changes in hysteresivity, G/H, under any condition. We conclude that not all aspects of the viscoelastic properties of tracheal smooth muscle strips are similar to those previously observed in cultured cells. We attribute these differences to the contribution of the extracellular matrix. Additionally, using a network model, we show that the dynamic nonlinear behavior, which has not been observed in cell culture, is associated with the state of the contractile stress and may derive from active polymerization within the cytoskeleton. PMID:16414980

  12. Calcineurin/Nuclear Factor of Activated T Cells–Coupled Vanilliod Transient Receptor Potential Channel 4 Ca2+ Sparklets Stimulate Airway Smooth Muscle Cell Proliferation

    PubMed Central

    Zhao, Limin; Sullivan, Michelle N.; Chase, Marlee; Gonzales, Albert L.

    2014-01-01

    Proliferation of airway smooth muscle cells (ASMCs) contributes to the remodeling and irreversible obstruction of airways during severe asthma, but the mechanisms underlying this disease process are poorly understood. Here we tested the hypothesis that Ca2+ influx through the vanilliod transient receptor potential channel (TRPV) 4 stimulates ASMC proliferation. We found that synthetic and endogenous TRPV4 agonists increase proliferation of primary ASMCs. Furthermore, we demonstrate that Ca2+ influx through individual TRPV4 channels produces Ca2+ microdomains in ASMCs, called “TRPV4 Ca2+ sparklets.” We also show that TRPV4 channels colocalize with the Ca2+/calmodulin–dependent protein phosphatase calcineurin in ASMCs. Activated calcineurin dephosphorylates nuclear factor of activated T cells (NFAT) transcription factors cytosolic (c) to allow nuclear translocation and activation of synthetic transcriptional pathways. We show that ASMC proliferation in response to TRPV4 activity is associated with calcineurin-dependent nuclear translocation of the NFATc3 isoform tagged with green florescent protein. Our findings suggest that Ca2+ microdomains created by TRPV4 Ca2+ sparklets activate calcineurin to stimulate nuclear translocation of NFAT and ASMC proliferation. These findings further suggest that inhibition of TRPV4 could diminish asthma-induced airway remodeling. PMID:24392954

  13. Anti-smooth muscle antibody

    MedlinePlus

    ... medlineplus.gov/ency/article/003531.htm Anti-smooth muscle antibody To use the sharing features on this page, please enable JavaScript. Anti-smooth muscle antibody is a blood test that detects the ...

  14. Sexual Dimorphism in the Regulation of Estrogen, Progesterone, and Androgen Receptors by Sex Steroids in the Rat Airway Smooth Muscle Cells

    PubMed Central

    Zarazúa, Abraham; González-Arenas, Aliesha; Ramírez-Vélez, Gabriela; Bazán-Perkins, Blanca; Guerra-Araiza, Christian; Campos-Lara, María G.

    2016-01-01

    The role of sex hormones in lung is known. The three main sex steroid receptors, estrogen, progesterone, and androgen, have not been sufficiently studied in airway smooth muscle cells (ASMC), and the sex hormone regulation on these receptors is unknown. We examined the presence and regulation of sex hormone receptors in female and male rat ASMC by Western blotting and flow cytometry. Gonadectomized rats were treated with 17β-estradiol, progesterone, 17β-estradiol + progesterone, or testosterone. ASMC were enzymatically isolated from tracheas and bronchi. The experiments were performed with double staining flow cytometry (anti-α-actin smooth muscle and antibodies to each hormone receptor). ERα, ERβ, tPR, and AR were detected in females or males. ERα was upregulated by E2 and T and downregulated by P4 in females; in males, ERα was downregulated by P4, E + P, and T. ERβ was downregulated by each treatment in females, and only by E + P and T in males. tPR was downregulated by P4, E + P, and T in females. No hormonal regulation was observed in male receptors. AR was downregulated in males treated with E + P and T. We have shown the occurrence of sex hormone receptors in ASMC and their regulation by the sex hormones in female and male rats. PMID:27110242

  15. Sexual Dimorphism in the Regulation of Estrogen, Progesterone, and Androgen Receptors by Sex Steroids in the Rat Airway Smooth Muscle Cells.

    PubMed

    Zarazúa, Abraham; González-Arenas, Aliesha; Ramírez-Vélez, Gabriela; Bazán-Perkins, Blanca; Guerra-Araiza, Christian; Campos-Lara, María G

    2016-01-01

    The role of sex hormones in lung is known. The three main sex steroid receptors, estrogen, progesterone, and androgen, have not been sufficiently studied in airway smooth muscle cells (ASMC), and the sex hormone regulation on these receptors is unknown. We examined the presence and regulation of sex hormone receptors in female and male rat ASMC by Western blotting and flow cytometry. Gonadectomized rats were treated with 17β-estradiol, progesterone, 17β-estradiol + progesterone, or testosterone. ASMC were enzymatically isolated from tracheas and bronchi. The experiments were performed with double staining flow cytometry (anti-α-actin smooth muscle and antibodies to each hormone receptor). ERα, ERβ, tPR, and AR were detected in females or males. ERα was upregulated by E2 and T and downregulated by P4 in females; in males, ERα was downregulated by P4, E + P, and T. ERβ was downregulated by each treatment in females, and only by E + P and T in males. tPR was downregulated by P4, E + P, and T in females. No hormonal regulation was observed in male receptors. AR was downregulated in males treated with E + P and T. We have shown the occurrence of sex hormone receptors in ASMC and their regulation by the sex hormones in female and male rats. PMID:27110242

  16. Upregulation of TRPM7 augments cell proliferation and interleukin-8 release in airway smooth muscle cells of rats exposed to cigarette smoke.

    PubMed

    Lin, Xiaoling; Yang, Cheng; Huang, Linjie; Chen, Ming; Shi, Jianting; Ouyang, Lihua; Tang, Tiantian; Zhang, Wei; Li, Yiqun; Liang, Ruiyun; Jiang, Shanping

    2016-06-01

    Proliferation and synthetic function (i.e. the capacity to release numerous chemokines and cytokines) of airway smooth muscle cells (ASMCs) are important in airway remodeling induced by cigarette smoke exposure. However, the molecular mechanism has not been clarified. Transient receptor potential cation channel subfamily M member 7 (TRPM7) is expressed ubiquitously and is crucial for the cellular physiological function of many cell types. The present study aimed to detect the expression of TRPM7 in ASMCs from smoke‑exposed rats and determine the importance of TRPM7 in proliferation and interleukin‑8 (IL‑8) release. ASMCs were isolated and cultured from smoke‑exposed rats. Expression levels of TRPM7 were determined by reverse transcription‑polymerase chain reaction, western blot analysis and immunofluorescence. TRPM7 was silenced with TRPM7‑short hairpin RNA lentivirus vector. DNA synthesis, cell number and IL‑8 release of ASMCs induced by cigarette smoke extract (CSE) and tumor necrosis factor‑α (TNF‑α) were assessed using [3H]-thymidine incorporation assay, hemocytometer and enzyme‑linked immunosorbent assay, respectively. It was determined that mRNA and protein expression levels of TRPM7 were increased in ASMCs from smoke‑exposed rats. Stimulation with CSE or TNF‑α elevated DNA synthesis, cell number and IL‑8 release were more marked in ASMCs from smoke‑exposed rats. Silencing of TRPM7 reduced DNA synthesis, cell number and IL‑8 release induced by CSE or TNF‑α in ASMCs from smoke-exposed rats. In conclusion, expression of TRPM7 increased significantly in ASMCs from smoke‑exposed rats and the upregulation of TRPM7 led to augmented cell proliferation and IL-8 release in ASMCs from rats exposed to cigarette smoke. PMID:27108806

  17. Upregulation of TRPM7 augments cell proliferation and interleukin-8 release in airway smooth muscle cells of rats exposed to cigarette smoke

    PubMed Central

    LIN, XIAOLING; YANG, CHENG; HUANG, LINJIE; CHEN, MING; SHI, JIANTING; OUYANG, LIHUA; TANG, TIANTIAN; ZHANG, WEI; LI, YIQUN; LIANG, RUIYUN; JIANG, SHANPING

    2016-01-01

    Proliferation and synthetic function (i.e. the capacity to release numerous chemokines and cytokines) of airway smooth muscle cells (ASMCs) are important in airway remodeling induced by cigarette smoke exposure. However, the molecular mechanism has not been clarified. Transient receptor potential cation channel subfamily M member 7 (TRPM7) is expressed ubiquitously and is crucial for the cellular physiological function of many cell types. The present study aimed to detect the expression of TRPM7 in ASMCs from smoke-exposed rats and determine the importance of TRPM7 in proliferation and interleukin-8 (IL-8) release. ASMCs were isolated and cultured from smoke-exposed rats. Expression levels of TRPM7 were determined by reverse transcription-polymerase chain reaction, western blot analysis and immunofluorescence. TRPM7 was silenced with TRPM7-short hairpin RNA lentivirus vector. DNA synthesis, cell number and IL-8 release of ASMCs induced by cigarette smoke extract (CSE) and tumor necrosis factor-α (TNF-α) were assessed using [3H]-thymidine incorporation assay, hemocytometer and enzyme-linked immunosorbent assay, respectively. It was determined that mRNA and protein expression levels of TRPM7 were increased in ASMCs from smoke-exposed rats. Stimulation with CSE or TNF-α elevated DNA synthesis, cell number and IL-8 release were more marked in ASMCs from smoke-exposed rats. Silencing of TRPM7 reduced DNA synthesis, cell number and IL-8 release induced by CSE or TNF-α in ASMCs from smoke-exposed rats. In conclusion, expression of TRPM7 increased significantly in ASMCs from smoke-exposed rats and the upregulation of TRPM7 led to augmented cell proliferation and IL-8 release in ASMCs from rats exposed to cigarette smoke. PMID:27108806

  18. Functional Effects of WNT1-Inducible Signaling Pathway Protein-1 on Bronchial Smooth Muscle Cell Migration and Proliferation in OVA-Induced Airway Remodeling.

    PubMed

    Yang, Mingjin; Du, Yuejun; Xu, Zhibo; Jiang, Youfan

    2016-02-01

    Upregulation of WISP1 has been demonstrated in lung remodeling. Moreover, it has been recently found that some signaling components of WNT pathway can activate GSK3β signaling to mediate remodeling of airway smooth muscle (ASM) in asthma. Therefore, we hypothesized that WISP1, a signaling molecule downstream of the WNT signaling pathway, is involved in PI3K/GSK3β signaling to mediate ASM remodeling in asthma. Our results showed that WISP1 depletion partly suppressed OVA-induced ASM hypertrophy in vivo. In vitro, WISP1 could induce hBSMC hypertrophy and proliferation, accompanied by upregulation of levels of PI3K, p-Akt, p-GSK3β, and its own expression. TGF-β treatment could increase expression of PI3K, p-Akt, p-GSK3β, and WISP1. SH-5 treatment could partly suppress TGF-β-induced hypertrophy and proliferation of hBSMC, and depress expression of p-GSK3β and WISP1. In conclusion, WISP1 may be a potential inducer of ASM proliferation and hypertrophy in asthma. The pro-remodeling effect of WISP1 is likely due to be involved in PI3K-GSK3β-dependent noncanonical TGF-β signaling. PMID:26242865

  19. Short-term variability in respiratory impedance and effect of deep breath in asthmatic and healthy subjects with airway smooth muscle activation and unloading.

    PubMed

    Gobbi, Alessandro; Pellegrino, Riccardo; Gulotta, Carlo; Antonelli, Andrea; Pompilio, Pasquale; Crimi, Claudia; Torchio, Roberto; Dutto, Luca; Parola, Paolo; Dellacà, Raffaele L; Brusasco, Vito

    2013-09-01

    Inspiratory resistance (RINSP) and reactance (XINSP) were measured for 7 min at 5 Hz in 10 subjects with mild asymptomatic asthma and 9 healthy subjects to assess the effects of airway smooth muscle (ASM) activation by methacholine (MCh) and unloading by chest wall strapping (CWS) on the variability of lung function and the effects of deep inspiration (DI). Subjects were studied at control conditions, after MCh, with CWS, and after MCh with CWS. In all experimental conditions XINSP was significantly more negative in subjects with asthma than in healthy subjects, suggesting greater inhomogeneity in the former. However, the variability in both RINSP and XINSP was increased by either ASM activation or CWS, without significant difference between groups. DI significantly reversed MCh-induced changes in RINSP both in subjects with asthma and healthy subjects, but XINSP in the former only. This effect was impaired by CWS more in subjects with asthma than in healthy subjects. The velocity of RINSP and XINSP recovery after DI was faster in subjects with asthma than healthy subjects. In conclusion, these results support the opinion that the short-term variability in respiratory impedance is related to ASM tone or operating length, rather than to the disease. Nevertheless, ASM in individuals with asthma differs from that in healthy individuals in an increased velocity of shortening and a reduced sensitivity to mechanical stress when strain is reduced. PMID:23766502

  20. Induction of cyclo-oxygenase-2 by cytokines in human cultured airway smooth muscle cells: novel inflammatory role of this cell type

    PubMed Central

    Belvisi, Maria G; Saunders, Michael A; Haddad, El-Bdaoui; Hirst, Stuart J; Yacoub, Magdi H; Barnes, Peter J; Mitchell, Jane A

    1997-01-01

    Cyclo-oxygenase (COX) is the enzyme that converts arachidonic acid to prostaglandin H2 (PGH2) which can then be further metabolized to prostanoids which modulate various airway functions. COX exists in at least two isoforms. COX-1 is expressed constitutively, whereas COX-2 is expressed in response to pro-inflammatory stimuli. Prostanoids are produced under physiological and pathophysiological conditions by many cell types in the lung. However, the regulation of the different COX isoforms in human airway smooth muscle (HASM) cells has not yet been determined.COX-1 and COX-2 protein were measured by Western blot analysis with specific antibodies for COX-1 and COX-2. COX-2 mRNA levels were assessed by Northern blot analysis by use of a COX-2 cDNA probe. COX activity was determined by measuring conversion of either endogenous or exogenous arachidonic acid to three metabolites, PGE2, thromboxane B2 or 6-ketoPGF1α by radioimmunoassay.Under control culture conditions HASM cells expressed COX-1, but not COX-2, protein. However, a mixture of cytokines (interleukin-1β (IL-1β), tumour necrosis factor α (TNFα) and interferon γ (IFNγ) each at 10 ng ml−1) induced COX-2 mRNA expression, which was maximal at 12 h and inhibited by dexamethasone (1 μM; added 30 min before the cytokines). Furthermore, COX-2 protein was detected 24 h after the cytokine treatment and the expression of this protein was also inhibited by dexamethasone (1 μM) and cyclohexamide (10 μg ml−1; added 30 min before the cytokines).Untreated HASM cells released low or undetectable amounts of all COX metabolites measured over a 24 h period. Incubation of the cells with the cytokine mixture (IL-1β, TNFα, IFNγ each at 10 ng ml−1 for 24 h) caused the accumulation of PGE2 and 6-keto-PGF1α.In experiments where COX-2 metabolized endogenous stores of arachidonic acid, treatment of HASM cells with IL-1β in combination with TNFα caused a similar release of PGE2 to that when

  1. Smooth Muscle Strips for Intestinal Tissue Engineering

    PubMed Central

    Walthers, Christopher M.; Lee, Min; Wu, Benjamin M.; Dunn, James C. Y.

    2014-01-01

    Functionally contracting smooth muscle is an essential part of the engineered intestine that has not been replicated in vitro. The purpose of this study is to produce contracting smooth muscle in culture by maintaining the native smooth muscle organization. We employed intact smooth muscle strips and compared them to dissociated smooth muscle cells in culture for 14 days. Cells isolated by enzymatic digestion quickly lost maturity markers for smooth muscle cells and contained few enteric neural and glial cells. Cultured smooth muscle strips exhibited periodic contraction and maintained neural and glial markers. Smooth muscle strips cultured for 14 days also exhibited regular fluctuation of intracellular calcium, whereas cultured smooth muscle cells did not. After implantation in omentum for 14 days on polycaprolactone scaffolds, smooth muscle strip constructs expressed high levels of smooth muscle maturity markers as well as enteric neural and glial cells. Intact smooth muscle strips may be a useful component for engineered intestinal smooth muscle. PMID:25486279

  2. Activity of the oxidation products of oleum terebinthinae "Landes" on guinea pig airway smooth muscle in vivo and in vitro.

    PubMed

    Bermudez, J; Burgess, M F; Cassidy, F; Clarke, G D

    1987-11-01

    The oxidation products of Oleum Terebinthinae "Landes" (Ozothin; in the following briefly called Ox. O. T. L.) have been described in many studies as being of benefit in the treatment of disturbed tracheobronchial function in obstructive airways diseases. Previous literature has dealt mainly with the influence of Ox. O. T. L. on the visco-elastic properties of mucus. However, the purpose of the present work was to study the bronchospasmolytic component. Using a standard methodology for the measurement of bronchospasmolytic effects, it could be demonstrated that Ox.O.T.L., given orally or as an aerosol, protected conscious guinea pigs against histamine-induced bronchoconstriction. The potency was lower than that of isoprenaline but was significant and reproducible. These results in vivo are paralleled by effects observed on guinea pig lung strips and tracheal spiral preparations. Ox.O.T.L. relaxed, in a dose-dependent fashion, guinea pig lung strip preparations contracted with histamine. Potency and efficacy was, however, less than that of isoprenaline. Similarly, in guinea pig tracheal spiral preparations, Ox.O.T.L. was less potent than isoprenaline in counteracting carbachol-elevated tone. However, efficacy equalled that of isoprenaline. Ox.O.T.L. was approximately 3 times more potent in the isolated tracheal spiral preparation than in lung strips. The activity of non-oxidised turpentine oil and terpin hydrate against histamine-induced bronchoconstriction in conscious animals and in the isolated organ preparations was substantially lower than that of the oxidation products of O.T.L. PMID:3440034

  3. Divergent modulation of Rho‐kinase and Ca2+ influx pathways by Src family kinases and focal adhesion kinase in airway smooth muscle

    PubMed Central

    Shaifta, Yasin; Irechukwu, Nneka; Prieto‐Lloret, Jesus; MacKay, Charles E; Marchon, Keisha A; Ward, Jeremy P T

    2015-01-01

    Background and Purpose The importance of tyrosine kinases in airway smooth muscle (ASM) contraction is not fully understood. The aim of this study was to investigate the role of Src‐family kinases (SrcFK) and focal adhesion kinase (FAK) in GPCR‐mediated ASM contraction and associated signalling events. Experimental Approach Contraction was recorded in intact or α‐toxin permeabilized rat bronchioles. Phosphorylation of SrcFK, FAK, myosin light‐chain‐20 (MLC20) and myosin phosphatase targeting subunit‐1 (MYPT‐1) was evaluated in cultured human ASM cells (hASMC). [Ca2+]i was evaluated in Fura‐2 loaded hASMC. Responses to carbachol (CCh) and bradykinin (BK) and the contribution of SrcFK and FAK to these responses were determined. Key Results Contractile responses in intact bronchioles were inhibited by antagonists of SrcFK, FAK and Rho‐kinase, while after α‐toxin permeabilization, they were sensitive to inhibition of SrcFK and Rho‐kinase, but not FAK. CCh and BK increased phosphorylation of MYPT‐1 and MLC20 and auto‐phosphorylation of SrcFK and FAK. MYPT‐1 phosphorylation was sensitive to inhibition of Rho‐kinase and SrcFK, but not FAK. Contraction induced by SR Ca2+ depletion and equivalent [Ca2+]i responses in hASMC were sensitive to inhibition of both SrcFK and FAK, while depolarization‐induced contraction was sensitive to FAK inhibition only. SrcFK auto‐phosphorylation was partially FAK‐dependent, while FAK auto‐phosphorylation was SrcFK‐independent. Conclusions and Implications SrcFK mediates Ca2+‐sensitization in ASM, while SrcFK and FAK together and individually influence multiple Ca2+ influx pathways. Tyrosine phosphorylation is therefore a key upstream signalling event in ASM contraction and may be a viable target for modulating ASM tone in respiratory disease. PMID:26294392

  4. Tumor Necrosis Factor Alpha Inhibits L-Type Ca2+ Channels in Sensitized Guinea Pig Airway Smooth Muscle through ERK 1/2 Pathway

    PubMed Central

    Reyes-García, Jorge; Flores-Soto, Edgar; Solís-Chagoyán, Héctor; Sommer, Bettina; Díaz-Hernández, Verónica; García-Hernández, Luz María

    2016-01-01

    Tumor necrosis factor alpha (TNF-α) is a potent proinflammatory cytokine that plays a significant role in the pathogenesis of asthma by inducing hyperresponsiveness and airway remodeling. TNF-α diminishes the L-type voltage dependent Ca2+ channel (L-VDCC) current in cardiac myocytes, an observation that seems paradoxical. In guinea pig sensitized tracheas KCl responses were lower than in control tissues. Serum from sensitized animals (Ser-S) induced the same phenomenon. In tracheal myocytes from nonsensitized (NS) and sensitized (S) guinea pigs, an L-VDCC current (ICa) was observed and diminished by Ser-S. The same decrease was detected in NS myocytes incubated with TNF-α, pointing out that this cytokine might be present in Ser-S. We observed that a small-molecule inhibitor of TNF-α (SMI-TNF) and a TNF-α receptor 1 (TNFR1) antagonist (WP9QY) reversed ICa decrease induced by Ser-S in NS myocytes, confirming the former hypothesis. U0126 (a blocker of ERK 1/2 kinase) also reverted the decrease in ICa. Neither cycloheximide (a protein synthesis inhibitor) nor actinomycin D (a transcription inhibitor) showed any effect on the TNF-α-induced ICa reduction. We found that CaV1.2 and CaV1.3 mRNA and proteins were expressed in tracheal myocytes and that sensitization did not modify them. In cardiac myocytes, ERK 1/2 phosphorylates two sites of the L-VDCC, augmenting or decreasing ICa; we postulate that, in guinea pig tracheal smooth muscle, TNF-α diminishes ICa probably by phosphorylating the L-VDCC site that reduces its activity through the ERK1/2 MAP kinase pathway. PMID:27445440

  5. Schisandrin B inhibits the proliferation of airway smooth muscle cells via microRNA-135a suppressing the expression of transient receptor potential channel 1.

    PubMed

    Zhang, Xiao-Yu; Zhang, Luo-Xian; Guo, Ya-Li; Zhao, Li-Min; Tang, Xue-Yi; Tian, Cui-Jie; Cheng, Dong-Jun; Chen, Xian-Liang; Ma, Li-Jun; Chen, Zhuo-Chang

    2016-07-01

    Airway smooth muscle cell (ASMC) was known to involve in the pathophysiology of asthma. Schisandrin B was reported to have anti-asthmatic effects in a murine asthma model. However, the molecular mechanism involving in the effect of Schisandrin B on ASMCs remains poorly understood. Sprague-Dawley rats were divided into three groups: rats as the control (Group 1), sensitized rats (Group 2), sensitized rats and intragastric-administrated Schisandrin B (Group 3). The expression of miR-135a and TRPC1 was detected in the rats from three groups. Platelet-derived growth factor (PDGF)-BB was used to induce the proliferation of isolated ASMCs, and the expression of miR-135a and TRPC1 was detected in PDGF-BB-treated ASMCs. Cell viability was examined in ASMCs transfected with miR-135a inhibitor or si-TRPC1. The expression of TRPC1 was examined in A10 cells pretreated with miR-135a inhibitor or miR-135a mimic. In this study, we found that Schisandrin B attenuated the inspiratory and expiratory resistances in sensitized rats. Schisandrin B upregulated the mRNA level of miR-135a and decreased the expression of TRPC1 in sensitized rats. In addition, Schisandrin B reversed the expression of miR-135a and TRPC1 in PDGF-BB-induced ASMCs. Si-TRPC1 abrogated the increasing proliferation of ASMCs induced by miR-135a inhibitor. We also found that miR-135a regulated the expression of TRPC1 in the A10 cells. These results demonstrate that Schisandrin B inhibits the proliferation of ASMCs via miR-135a suppressing the expression of TRPC1. PMID:26916957

  6. Theophylline Represses IL-8 Secretion from Airway Smooth Muscle Cells Independently of Phosphodiesterase Inhibition. Novel Role as a Protein Phosphatase 2A Activator.

    PubMed

    Patel, Brijeshkumar S; Rahman, Md Mostafizur; Rumzhum, Nowshin N; Oliver, Brian G; Verrills, Nicole M; Ammit, Alaina J

    2016-06-01

    Theophylline is an old drug experiencing a renaissance owing to its beneficial antiinflammatory effects in chronic respiratory diseases, such as asthma and chronic obstructive pulmonary disease. Multiple modes of antiinflammatory action have been reported, including inhibition of the enzymes that degrade cAMP-phosphodiesterase (PDE). Using primary cultures of airway smooth muscle (ASM) cells, we recently revealed that PDE4 inhibitors can potentiate the antiinflammatory action of β2-agonists by augmenting cAMP-dependent expression of the phosphatase that deactivates mitogen-activated protein kinase (MAPK)-MAPK phosphatase (MKP)-1. Therefore, the aim of this study was to address whether theophylline repressed cytokine production in a similar, PDE-dependent, MKP-1-mediated manner. Notably, theophylline did not potentiate cAMP release from ASM cells treated with the long-acting β2-agonist formoterol. Moreover, theophylline (0.1-10 μM) did not increase formoterol-induced MKP-1 messenger RNA expression nor protein up-regulation, consistent with the lack of cAMP generation. However, theophylline (at 10 μM) was antiinflammatory and repressed secretion of the neutrophil chemoattractant cytokine IL-8, which is produced in response to TNF-α. Because theophylline's effects were independent of PDE4 inhibition or antiinflammatory MKP-1, we then wished to elucidate the novel mechanisms responsible. We investigated the impact of theophylline on protein phosphatase (PP) 2A, a master controller of multiple inflammatory signaling pathways, and show that theophylline increases TNF-α-induced PP2A activity in ASM cells. Confirmatory results were obtained in A549 lung epithelial cells. PP2A activators have beneficial effects in ex vivo and in vivo models of respiratory disease. Thus, our study is the first to link theophylline with PP2A activation as a novel mechanism to control respiratory inflammation. PMID:26574643

  7. Inositol 1,4,5-trisphosphate activates TRPC3 channels to cause extracellular Ca2+ influx in airway smooth muscle cells.

    PubMed

    Song, Tengyao; Hao, Qiongyu; Zheng, Yun-Min; Liu, Qing-Hua; Wang, Yong-Xiao

    2015-12-15

    Transient receptor potential-3 (TRPC3) channels play a predominant role in forming nonselective cation channels (NSCCs) in airway smooth muscle cells (ASMCs) and are significantly increased in their activity and expression in asthmatic ASMCs. To extend these novel findings, we have explored the regulatory mechanisms that control the activity of TRPC3 channels. Our data for the first time reveal that inositol 1,4,5-trisphosphate (IP3), an important endogenous signaling molecule, can significantly enhance the activity of single NSCCs in ASMCs. The analog of diacylglycerol (DAG; another endogenous signaling molecule), 1-oleyl-2-acetyl-sn-glycerol (OAG), 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG), and 1-stearoyl-2-linoleoyl-sn-glycerol (SLG) all augment NSCC activity. The effects of IP3 and OAG are fully abolished by lentiviral short-hairpin (sh)RNA-mediated TRPC3 channel knockdown (KD). The stimulatory effect of IP3 is eliminated by heparin, an IP3 receptor (IP3R) antagonist that blocks the IP3-binding site, but not by xestospongin C, the IP3R antagonist that has no effect on the IP3-binding site. Lentiviral shRNA-mediated KD of IP3R1, IP3R2, or IP3R3 does not alter the excitatory effect of IP3. TRPC3 channel KD greatly inhibits IP3-induced increase in intracellular Ca(2+) concentration. IP3R1 KD produces a similar inhibitory effect. TRPC3 channel and IP3R1 KD both diminish the muscarinic receptor agonist methacholine-evoked Ca(2+) responses. Taking these findings together, we conclude that IP3, the important intracellular second messenger, may activate TRPC3 channels to cause extracellular Ca(2+) influx, in addition to opening IP3Rs to induce intracellular Ca(2+) release. This novel extracellular Ca(2+) entry route may play a significant role in mediating IP3-mediated numerous cellular responses in ASMCs and other cells. PMID:26453517

  8. The small heat shock-related protein, HSP20, is a cAMP-dependent protein kinase substrate that is involved in airway smooth muscle relaxation

    PubMed Central

    Komalavilas, Padmini; Penn, Raymond B.; Flynn, Charles R.; Thresher, Jeffrey; Lopes, Luciana B.; Furnish, Elizabeth J.; Guo, Manhong; Pallero, Manuel A.; Murphy-Ullrich, Joanne E.; Brophy, Colleen M.

    2009-01-01

    Activation of the cAMP/cAMP-dependent PKA pathway leads to relaxation of airway smooth muscle (ASM). The purpose of this study was to examine the role of the small heat shock-related protein HSP20 in mediating PKA-dependent ASM relaxation. Human ASM cells were engineered to constitutively express a green fluorescent protein-PKA inhibitory fusion protein (PKI-GFP) or GFP alone. Activation of the cAMP-dependent signaling pathways by isoproterenol (ISO) or forskolin led to increases in the phosphorylation of HSP20 in GFP but not PKI-GFP cells. Forskolin treatment in GFP but not PKI-GFP cells led to a loss of central actin stress fibers and decreases in the number of focal adhesion complexes. This loss of stress fibers was associated with dephosphorylation of the actin-depolymerizing protein cofilin in GFP but not PKI-GFP cells. To confirm that phosphorylated HSP20 plays a role in PKA-induced ASM relaxation, intact strips of bovine ASM were precontracted with serotonin followed by ISO. Activation of the PKA pathway led to relaxation of bovine ASM, which was associated with phosphorylation of HSP20 and dephosphorylation of cofilin. Finally, treatment with phosphopeptide mimetics of HSP20 possessing a protein transduction domain partially relaxed precontracted bovine ASM strips. In summary, ISO-induced phosphorylation of HSP20 or synthetic phosphopeptide analogs of HSP20 decreases phosphorylation of cofilin and disrupts actin in ASM, suggesting that one possible mechanism by which HSP20 mediates ASM relaxation is via regulation of actin filament dynamics. PMID:17993590

  9. Tumor Necrosis Factor Alpha Inhibits L-Type Ca(2+) Channels in Sensitized Guinea Pig Airway Smooth Muscle through ERK 1/2 Pathway.

    PubMed

    Reyes-García, Jorge; Flores-Soto, Edgar; Solís-Chagoyán, Héctor; Sommer, Bettina; Díaz-Hernández, Verónica; García-Hernández, Luz María; Montaño, Luis M

    2016-01-01

    Tumor necrosis factor alpha (TNF-α) is a potent proinflammatory cytokine that plays a significant role in the pathogenesis of asthma by inducing hyperresponsiveness and airway remodeling. TNF-α diminishes the L-type voltage dependent Ca(2+) channel (L-VDCC) current in cardiac myocytes, an observation that seems paradoxical. In guinea pig sensitized tracheas KCl responses were lower than in control tissues. Serum from sensitized animals (Ser-S) induced the same phenomenon. In tracheal myocytes from nonsensitized (NS) and sensitized (S) guinea pigs, an L-VDCC current (ICa) was observed and diminished by Ser-S. The same decrease was detected in NS myocytes incubated with TNF-α, pointing out that this cytokine might be present in Ser-S. We observed that a small-molecule inhibitor of TNF-α (SMI-TNF) and a TNF-α receptor 1 (TNFR1) antagonist (WP9QY) reversed ICa decrease induced by Ser-S in NS myocytes, confirming the former hypothesis. U0126 (a blocker of ERK 1/2 kinase) also reverted the decrease in ICa. Neither cycloheximide (a protein synthesis inhibitor) nor actinomycin D (a transcription inhibitor) showed any effect on the TNF-α-induced ICa reduction. We found that CaV1.2 and CaV1.3 mRNA and proteins were expressed in tracheal myocytes and that sensitization did not modify them. In cardiac myocytes, ERK 1/2 phosphorylates two sites of the L-VDCC, augmenting or decreasing ICa; we postulate that, in guinea pig tracheal smooth muscle, TNF-α diminishes ICa probably by phosphorylating the L-VDCC site that reduces its activity through the ERK1/2 MAP kinase pathway. PMID:27445440

  10. Suppression of the increasing level of acetylcholine-stimulated intracellular Ca2+ in guinea pig airway smooth muscle cells by mabuterol

    PubMed Central

    SONG, XIRUI; ZHAO, CHAO; DAI, CAILING; REN, YANXIN; AN, NAN; WEN, HUIMIN; PAN, LI; CHENG, MAOSHENG; ZHANG, YUYANG

    2015-01-01

    The present study aimed to establish an effective method for the in vitro culture of guinea pig airway smooth muscle (ASM) cells, and also investigate the suppressive effect of mabuterol hydrochloride (Mab) on the increased level of intracellular Ca2+ in ASM cells induced with acetylcholine (Ach). Two different methods, i.e. with or without collagenase to pretreat tracheal tissues, were applied to the manufacture of ASM cells. Cell viability was determined with the 3-(4,5-dimethylthinazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Immunocytochemistry and immunofluorescence were used for the identification of ASM cells. Different concentration levels (10−3, 10−4, 10−5, 10−6 and 10−7 mmol/l) of Mab were administered 5 min before Ach (10−4 M) treatment, respectively. The Ca2+ fluorescent probe, Fura-2/AM or Fluo-3/AM were applied to the inspection of Ca2+ fluorescent intensity with Varioskan Flash, immunocytometry systems and an inverted system microscope, respectively. The results showed that the fresh method, in which isolated tracheal tissues were previously treated with collagenase for 20 min, was more advantageous for the preparation of guinea pig ASM cells compared to when the enzyme was not used. The time for the ASM cells to initially migrate out of the ‘tissue blocks’ and the culture having to be generated due to the thick cell density was significantly less. On identification with immunocytochemistry or immunofluorescent staining, >95% of the cells were ASM cells. Mab (10−3−10−7 mmol/l) significantly suppressed the elevation of intracellular Ca2+ induced by Ach in a concentration-dependent manner. The inhibitory rates of intracellular Ca2+ by different concentrations of Mab, from low to high, were 14.93, 24.73, 40.06, 48.54 and 57.13%, respectively, when Varioskan Flash was used for determination. In conclusion, this novel method has a shorter harvesting period for ASM cells. Mab can suppress the increasing level of intracellular Ca2

  11. A systematic study on the influence of the main ingredients of an ivy leaves dry extract on the β2-adrenergic responsiveness of human airway smooth muscle cells.

    PubMed

    Greunke, Christian; Hage-Hülsmann, Anne; Sorkalla, Thomas; Keksel, Nelli; Häberlein, Felix; Häberlein, Hanns

    2015-04-01

    The bronchospasmolytic and secretolytic effects of ivy leaves dry extracts can be explained by an increased β2-adrenergic responsiveness of the bronchi. Recently, it was shown that α-hederin inhibits the internalization of β2-adrenergic receptors (ß2AR) under stimulating conditions. α-Hederin pretreated alveolar type II cells and human airway smooth muscle cells revealed an increased ß2AR binding and an elevated intracellular cAMP level, respectively. In order to identify whether additional compounds also mediate an increased β2-adrenergic responsiveness, we examined the ingredients of an ivy leaves dry extract (EA 575) protocatechuic acid, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, rutin, kaempferol-3-O-rutinoside, 3,4-, 3,5- and 4,5-dicaffeoylquinic acid, hederacoside B, and β-hederin. Within all the tested substances, only β-hederin inhibited the internalization of GFP-tagged ß2AR in stably transfected HEK293 cells. Using fluorescence correlation spectroscopy β-hederin (1 μM, 24 h) pretreated HASM cells showed a statistically significant increase in the ß2AR binding from 33.0 ± 8.9% to 44.1 ± 11.5% which was distributed with 36.0 ± 9.5% for τbound1 and 8.1 ± 2.6% for τbound2, respectively (n = 8, p < 0.05). The increased binding was selectively found for the receptor-ligand complex with unrestricted lateral mobility (τbound1 of 0.9 ± 0.1 ms, D1 = 9.1 ± 0.2 μm(2)/s, n = 8), whereas the binding of ß2AR with hindered lateral mobility (τbound2 of 64.2 ± 47.6 ms, D2 = 0.15 ± 0.02 μm(2)/s, n = 8) was not affected. Compared to control cells, a statistically significant increase of 17.5 ± 6.4% (n = 4, p < 0.05) and 24.2 ± 5.8% (n = 4, p < 0.001) in the cAMP formation was found for β-hederin pretreated HASM cells after stimulation with 10 μM of terbutaline and simultaneous stimulation with 10 μM terbutaline and 10 μM forskolin, respectively. Within this systematic study

  12. Vascular smooth muscle in hypertension.

    PubMed

    Winquist, R J; Webb, R C; Bohr, D F

    1982-06-01

    The cause of the elevated arterial pressure in most forms of hypertension is an increase in total peripheral resistance. This brief review is directed toward an assessment of recent investigations contributing information about the factors responsible for this increased vascular resistance. Structural abnormalities in the vasculature that characterize the hypertensive process are 1) changes in the vascular media, 2) rarefication of the resistance vessels, and 3) lesions of the intimal vascular surface. These abnormalities are mainly the result of an adaptive process and are secondary to the increase in wall stress and/or to pathological damage to cellular components in the vessel wall. Functional alterations in the vascular smooth muscle are described as changes in agonist-smooth muscle interaction or plasma membrane permeability. These types of changes appear to play a primary, initiating role in the elevation of vascular resistance of hypertension. These alterations are not the result of an increase in wall stress and they often precede the development of high blood pressure. The functional changes are initiated by abnormal function of neurogenic, humoral, and/or myogenic changes that alter vascular smooth muscle activity. PMID:6282652

  13. Calcium Signaling in Smooth Muscle

    PubMed Central

    Hill-Eubanks, David C.; Werner, Matthias E.; Heppner, Thomas J.; Nelson, Mark T.

    2011-01-01

    Changes in intracellular Ca2+ are central to the function of smooth muscle, which lines the walls of all hollow organs. These changes take a variety of forms, from sustained, cell-wide increases to temporally varying, localized changes. The nature of the Ca2+ signal is a reflection of the source of Ca2+ (extracellular or intracellular) and the molecular entity responsible for generating it. Depending on the specific channel involved and the detection technology employed, extracellular Ca2+ entry may be detected optically as graded elevations in intracellular Ca2+, junctional Ca2+ transients, Ca2+ flashes, or Ca2+ sparklets, whereas release of Ca2+ from intracellular stores may manifest as Ca2+ sparks, Ca2+ puffs, or Ca2+ waves. These diverse Ca2+ signals collectively regulate a variety of functions. Some functions, such as contractility, are unique to smooth muscle; others are common to other excitable cells (e.g., modulation of membrane potential) and nonexcitable cells (e.g., regulation of gene expression). PMID:21709182

  14. Research Upregulation of CD23 (FcεRII) Expression in Human Airway Smooth Muscle Cells (huASMC) in Response to IL-4, GM-CSF, and IL-4/GM-CSF

    PubMed Central

    Belleau, Joseph T; Gandhi, Radha K; McPherson, Holly M; Lew, D Betty

    2005-01-01

    Background Airway smooth muscle cells play a key role in remodeling that contributes to airway hyperreactivity. Airway smooth muscle remodeling includes hypertrophy and hyperplasia. It has been previously shown that the expression of CD23 on ASMC in rabbits can be induced by the IgE component of the atopic serum. We examined if other components of atopic serum are capable of inducing CD23 expression independent of IgE. Methods Serum starved huASMC were stimulated with either IL-4, GM-CSF, IL-13, IL-5, PGD2, LTD4, tryptase or a combination of IL-4, IL-5, IL-13 each with GM-CSF for a period of 24 h. CD23 expression was analyzed by flow cytometry, western blot, and indirect immunofluorescence. Results The CD23 protein expression was upregulated in huASMC in response to IL-4, GM-CSF, and IL-4/GM-CSF. The percentage of cells with increased fluorescence intensity above the control was 25.1 ± 4.2% (IL-4), 15.6 ± 2.7% (GM-CSF) and 32.9 ± 13.9% (IL-4/GMCSF combination)(n = 3). The protein content of IL-4/GMCSF stimulated cells was significantly elevated. Expression of CD23 in response to IL-4, GM-CSF, IL-4/GM-CSF was accompanied by changes in cell morphology including depolymerization of isoactin fibers, cell spreading, and membrane ruffling. Western blot revealed abundant expression of the IL-4Rα and a low level expression of IL-2Rγc in huASMC. Stimulation with IL-4 resulted in the phosphorylation of STAT-6 and an increase in the expression of the IL-2Rγc. Conclusion CD23 on huASMC is upregulated by IL-4, GM-CSF, and IL-4/GM-CSF. The expression of CD23 is accompanied by an increase in cell volume and an increase in protein content per cell, suggesting hypertrophy. Upregulation of CD23 by IL-4/GM-CSF results in phenotypic changes in huASMC that could play a role in cell migration or a change in the synthetic function of the cells. Upregulation of CD23 in huASMC by IL-4 and GM-CSF can contribute to changes in huASMC and may provide an avenue for new therapeutic options

  15. An invertebrate smooth muscle with striated muscle myosin filaments

    PubMed Central

    Sulbarán, Guidenn; Alamo, Lorenzo; Pinto, Antonio; Márquez, Gustavo; Méndez, Franklin; Padrón, Raúl; Craig, Roger

    2015-01-01

    Muscle tissues are classically divided into two major types, depending on the presence or absence of striations. In striated muscles, the actin filaments are anchored at Z-lines and the myosin and actin filaments are in register, whereas in smooth muscles, the actin filaments are attached to dense bodies and the myosin and actin filaments are out of register. The structure of the filaments in smooth muscles is also different from that in striated muscles. Here we have studied the structure of myosin filaments from the smooth muscles of the human parasite Schistosoma mansoni. We find, surprisingly, that they are indistinguishable from those in an arthropod striated muscle. This structural similarity is supported by sequence comparison between the schistosome myosin II heavy chain and known striated muscle myosins. In contrast, the actin filaments of schistosomes are similar to those of smooth muscles, lacking troponin-dependent regulation. We conclude that schistosome muscles are hybrids, containing striated muscle-like myosin filaments and smooth muscle-like actin filaments in a smooth muscle architecture. This surprising finding has broad significance for understanding how muscles are built and how they evolved, and challenges the paradigm that smooth and striated muscles always have distinctly different components. PMID:26443857

  16. Mechanics of Vascular Smooth Muscle.

    PubMed

    Ratz, Paul H

    2015-01-01

    Vascular smooth muscle (VSM; see Table 1 for a list of abbreviations) is a heterogeneous biomaterial comprised of cells and extracellular matrix. By surrounding tubes of endothelial cells, VSM forms a regulated network, the vasculature, through which oxygenated blood supplies specialized organs, permitting the development of large multicellular organisms. VSM cells, the engine of the vasculature, house a set of regulated nanomotors that permit rapid stress-development, sustained stress-maintenance and vessel constriction. Viscoelastic materials within, surrounding and attached to VSM cells, comprised largely of polymeric proteins with complex mechanical characteristics, assist the engine with countering loads imposed by the heart pump, and with control of relengthening after constriction. The complexity of this smart material can be reduced by classical mechanical studies combined with circuit modeling using spring and dashpot elements. Evaluation of the mechanical characteristics of VSM requires a more complete understanding of the mechanics and regulation of its biochemical parts, and ultimately, an understanding of how these parts work together to form the machinery of the vascular tree. Current molecular studies provide detailed mechanical data about single polymeric molecules, revealing viscoelasticity and plasticity at the protein domain level, the unique biological slip-catch bond, and a regulated two-step actomyosin power stroke. At the tissue level, new insight into acutely dynamic stress-strain behavior reveals smooth muscle to exhibit adaptive plasticity. At its core, physiology aims to describe the complex interactions of molecular systems, clarifying structure-function relationships and regulation of biological machines. The intent of this review is to provide a comprehensive presentation of one biomachine, VSM. PMID:26756629

  17. Leiomodin and tropomodulin in smooth muscle

    NASA Technical Reports Server (NTRS)

    Conley, C. A.

    2001-01-01

    Evidence is accumulating to suggest that actin filament remodeling is critical for smooth muscle contraction, which implicates actin filament ends as important sites for regulation of contraction. Tropomodulin (Tmod) and smooth muscle leiomodin (SM-Lmod) have been found in many tissues containing smooth muscle by protein immunoblot and immunofluorescence microscopy. Both proteins cofractionate with tropomyosin in the Triton-insoluble cytoskeleton of rabbit stomach smooth muscle and are solubilized by high salt. SM-Lmod binds muscle tropomyosin, a biochemical activity characteristic of Tmod proteins. SM-Lmod staining is present along the length of actin filaments in rat intestinal smooth muscle, while Tmod stains in a punctate pattern distinct from that of actin filaments or the dense body marker alpha-actinin. After smooth muscle is hypercontracted by treatment with 10 mM Ca(2+), both SM-Lmod and Tmod are found near alpha-actinin at the periphery of actin-rich contraction bands. These data suggest that SM-Lmod is a novel component of the smooth muscle actin cytoskeleton and, furthermore, that the pointed ends of actin filaments in smooth muscle may be capped by Tmod in localized clusters.

  18. A long-acting β2-adrenergic agonist increases the expression of muscarine cholinergic subtype-3 receptors by activating the β2-adrenoceptor cyclic adenosine monophosphate signaling pathway in airway smooth muscle cells

    PubMed Central

    LIU, YUAN-HUA; WU, SONG-ZE; WANG, GANG; HUANG, NI-WEN; LIU, CHUN-TAO

    2015-01-01

    The persistent administration of β2-adrenergic (β2AR) agonists has been demonstrated to increase the risk of severe asthma, partly due to the induction of tolerance to bronchoprotection via undefined mechanisms. The present study investigated the potential effect of the long-acting β2-adrenergic agonist, formoterol, on the expression of muscarinic M3 receptor (M3R) in rat airway smooth muscle cells (ASMCs). Primary rat ASMCs were isolated and characterized following immunostaining with anti-α-smooth muscle actin antibodies. The protein expression levels of M3R and phospholipase C-β1 (PLCβ1) were characterized by western blot analysis and the production of inositol 1,4,5-trisphosphate (IP3) was determined using an enzyme-linked immunosorbent assay. Formoterol increased the protein expression of M3R in rat ASMCs in a time- and dose-dependent manner, which was significantly inhibited by the β2AR antagonist, ICI118,551 and the cyclic adenosine monophosphate (cAMP) inhibitor, SQ22,536. The increased protein expression of M3R was positively correlated with increased production of PLCβ1 and IP3. Furthermore, treatment with the glucocorticoid, budesonide, and the PLC inhibitor, U73,122, significantly suppressed the formoterol-induced upregulated protein expression levels of M3R and PLCβ1 and production of IP3. The present study demonstrated that formoterol mediated the upregulation of M3R in the rat ASMCs by activating the β2AR-cAMP signaling pathway, resulting in increased expression levels of PLCβ1 and IP3, which are key to inducing bronchoprotection tolerance. Administration of glucocorticoids or a PLC antagonist prevented formoterol-induced bronchoprotection tolerance by suppressing the protein expression of M3R. PMID:25672589

  19. 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

  20. 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

  1. Caveolae in smooth muscles: nanocontacts

    PubMed Central

    Popescu, LM; Gherghiceanu, Mihaela; Mandache, E; Cretoiu, D

    2006-01-01

    Smooth muscle cell (SMC) caveolae have been investigated by quantitative and qualitative analysis of transmission electron microscopy (TEM) images of rat stomach, bladder and myometrium, guinea pig taenia coli, human ileum, and rat aortic SMCs. Ultrathin (below 30 nm) serial sections were used for examination of caveolar morphology and their connections with SMC organelles. Average caveolar diameter was smaller in vascular SMCs (70 nm, n=50) than in visceral SMCs (77 nm, n=100), but with the same morphology. Most of the caveolae, featured as flask-shaped plasma membrane (PM) invaginations, opened to the extracellular space through a 20 nm stoma (21, 3nm) having a 7 nm thick diaphragm. A small percentage of caveolae (3%), gathered as grape-like clusters, did not open directly to the extracellular space, but to irregular PM pockets having a 20-30 nm opening to the extracellular space. In visceral SMCs, caveolae were disposed in 4 - 6 rows, parallel to myofilaments, whilst aortic SMCs caveolae were arranged as clusters. This caveolar organization in rows or clusters minimizes the occupied volume, providing more space for the contractile machinery. The morphometric analysis of relative volumes (% of cell volume) showed that caveolae were more conspicuous in visceral than in vascular SMCs (myometrium - 2.40%; bladder - 3.66%, stomach - 2.61%, aorta - 1.43%). We also observed a higher number of caveolae per length unit of cell membrane in most visceral SMCs compared to vascular SMCs (myometrium - 1.06/μm, bladder - 0.74/μm, aorta - 0.57/μm, stomach - 0.48/μm). Caveolae increase the cellular perimeter up to 15% and enlarge the surface area of the plasma membrane about 80% in SMCs. Three-dimensional reconstructions (15μ3) showed that most caveolae, in both visceral and vascular SMCs, have nanocontacts with SR (87%), or with mitochondria (10%), and only 3%, apparently, have no contact with these organelles. Usually, 15 nm wide junctional spaces exist between caveolae

  2. Autonomic Modification of Intestinal Smooth Muscle Contractility

    ERIC Educational Resources Information Center

    Montgomery, Laura E. A.; Tansey, Etain A.; Johnson, Chris D.; Roe, Sean M.; Quinn, Joe G.

    2016-01-01

    Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe…

  3. Abnormal tracheal smooth muscle function in the CF mouse

    PubMed Central

    Wallace, Helen L; Southern, Kevin W; Connell, Marilyn G; Wray, Susan; Burdyga, Theodor

    2013-01-01

    Increased airway smooth muscle (ASM) contractility is thought to underlie symptoms of airway hyperresponsiveness (AHR). In the cystic fibrosis (CF) airway, ASM anomalies have been reported, but have not been fully characterized and the underlying mechanisms are largely unknown. We examined ASM in an adult CF mouse tracheal ring preparation, and determined whether changes in contractility were associated with altered ASM morphology. We looked for inherent changes in the cellular pathways involved in contractility, and characterized trachea morphology in the adult trachea and in an embryonic lung culture model during development. Results showed that that there was a reduction in tracheal caliber in CF mice as indicated by a reduction in the number of cartilage rings; proximal cross-sectional areas of cftr−/− tracheas and luminal areas were significantly smaller, but there was no difference in the area or distribution of smooth muscle. Morphological differences observed in adult trachea were not evident in the embryonic lung at 11.5 days gestation or after 72 h in culture. Functional data showed a significant reduction in the amplitude and duration of contraction in response to carbachol (CCh) in Ca-free conditions. The reduction in contraction was agonist specific, and occurred throughout the length of the trachea. These data show that there is a loss in the contractile capacity of the CF mouse trachea due to downregulation of the pathway specific to acetylcholine (ACh) activation. This reduction in contraction is not associated with changes in the area or distribution of ASM. PMID:24400140

  4. 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

  5. Long-term effects of acupuncture treatment on airway smooth muscle in a rat model of smoke-induced chronic obstructive pulmonary disease

    PubMed Central

    Li, Jia; Wu, Song; Tang, Hongtu; Huang, Wei; Wang, Lushan; Zhou, Huanjiao; Zhou, Miao; Wang, Hua; Li, Jing

    2016-01-01

    Background Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. It is a chronic inflammatory process characterised by airway obstruction and progressive lung inflammation, associated with difficulty breathing and insensitivity to corticosteroid therapy. Although there is some preliminary evidence to suggest a beneficial effect of acupuncture on COPD, its mechanism of action has not been investigated. Our aim was to examine the anti-inflammatory effects of acupuncture in a rat model of COPD induced by exposure to cigarette smoke (CS). Methods Sixty Sprague–Dawley rats were exposed to the smoke of 15 cigarettes for 1 h/day, 6 days/week for 3 months to induce COPD and treated with acupuncture at BL13 (Feishu), BL23 (Shenshu) and Dingchuan (COPD+Acupuncture, n=15), sham acupuncture (COPD+Sham, n=15) or left untreated (n=15). Exposed rats were compared with controls not exposed to CS (control, n=15). Pulmonary function was measured, and tumour necrosis factor-α (TNF-α) and interleukin-8 (IL-8) levels were determined in bronchoalveolar lavage fluid by ELISA. Histone deacetylase 2 (HDAC2) protein and mRNA expression were examined in lung tissue and in bronchus. Results Acupuncture treatment appeared to protect pulmonary function and reduce the COPD-induced inflammatory response by decreasing cell inflammation and the production of TNF-α and IL-8. Acupuncture also enhanced HDAC2 mRNA and protein expression, suggesting a possible direct effect on protein structure through post-translational modifications. Conclusions Our results suggest that acupuncture regulates inflammatory cytokines and contributes to lung protection in a rat model of smoke-induced COPD by modulating HDAC2. PMID:26345700

  6. Platelet-derived-growth-factor stimulation of the p42/p44 mitogen-activated protein kinase pathway in airway smooth muscle: role of pertussis-toxin-sensitive G-proteins, c-Src tyrosine kinases and phosphoinositide 3-kinase.

    PubMed Central

    Conway, A M; Rakhit, S; Pyne, S; Pyne, N J

    1999-01-01

    The mechanism used by the platelet-derived growth factor receptor (PDGFR) to activate the mitogen-activated- protein-kinase (p42/p44 MAPK) pathway was investigated in cultured airway smooth muscle (ASM) cells. We have found that pertussis toxin (PTX, which was used to inactivate the heterotrimeric G-protein Gi) induced an approx. 40-50% decrease in the activation of c-Src and p42/p44 MAPK by PDGF. An essential role for c-Src was confirmed using the c-Src inhibitor, PP1, which abolished p42/p44 MAPK activation (PP1 and PTX were without effect on PDGFR tyrosine phosphorylation). Furthermore, the PTX-dependent decrease in c-Src and p42/p44 MAPK activation appeared correlated. These findings suggest that the PDGFR can utilize the PTX-sensitive G-protein, Gi, to regulate c-Src and subsequent p42/p44 MAPK activation. Phosphoinositide 3-kinase (PI3K) has been shown by others to be involved in p42/p44 MAPK activation. This is confirmed here by experiments which showed that PI3K inhibitors (wortmannin and LY294002) reduced the activation of p42/p44 MAPK by PDGF. PI3K activity was increased in Grb-2 immunoprecipitates from PDGF-stimulated cells and was decreased by pretreating these cells with PTX. These findings show that Gi might also promote Grb-2-PI3K complex formation and that Grb-2 may be a site at which PI3K is integrated into the p42/p44 MAPK cascade. In conclusion, our results demonstrate that Gi enables the PDGFR to signal more efficiently to p42/p44 MAPK, and this appears to be achieved through the regulation of c-Src and Grb-2/PI3K, which are intermediates in the p42/p44 MAPK cascade. PMID:9882612

  7. Sphingosine 1-phosphate stimulation of the p42/p44 mitogen-activated protein kinase pathway in airway smooth muscle. Role of endothelial differentiation gene 1, c-Src tyrosine kinase and phosphoinositide 3-kinase.

    PubMed Central

    Rakhit, S; Conway, A M; Tate, R; Bower, T; Pyne, N J; Pyne, S

    1999-01-01

    We report here that cultured airway smooth muscle cells contain transcripts of endothelial differentiation gene 1 (EDG-1), a prototypical orphan Gi-coupled receptor whose natural ligand is sphingosine 1-phosphate (S1P). This is consistent with data that showed that S1P activated both c-Src and p42/p44 mitogen-activated protein kinase (p42/p44 MAPK) in a pertussis toxin (PTX)-sensitive manner in these cells. An essential role for c-Src was confirmed by using the c-Src inhibitor, PP1, which markedly decreased p42/p44 MAPK activation. We have also shown that phosphoinositide 3-kinase (PI-3K) inhibitors (wortmannin and LY294002) decreased p42/p44 MAPK activation. An essential role for PI-3K was supported by experiments that showed that PI-3K activity was increased in Grb-2 immunoprecipitates from S1P-stimulated cells. Significantly, Grb-2 associated PI-3K activity was decreased by pretreatment of cells with PTX. Finally, we have shown that the co-stimulation of cells with platelet-derived growth factor (PDGF) and S1P (which failed to stimulate DNA synthesis) elicited a larger p42/p44 MAPK activation over a 30 min stimulation compared with each agonist alone. This was associated with a S1P-dependent increase in PDGF-stimulated DNA synthesis. These results demonstrate that S1P activates c-Src and Grb-2-PI-3K (intermediates in the p42/p44 MAPK cascade) via a PTX-sensitive mechanism. This action of S1P is consistent with the stimulation of EDG-1 receptors. S1P might also function as a co-mitogen with PDGF, producing a more robust activation of a common permissive signal transduction pathway linked to DNA synthesis. PMID:10051434

  8. Autonomic modification of intestinal smooth muscle contractility.

    PubMed

    Montgomery, Laura E A; Tansey, Etain A; Johnson, Chris D; Roe, Sean M; Quinn, Joe G

    2016-03-01

    Intestinal smooth muscle contracts rhythmically in the absence of nerve and hormonal stimulation because of the activity of pacemaker cells between and within the muscle layers. This means that the autonomic nervous system modifies rather than initiates intestinal contractions. The practical described here gives students an opportunity to observe this spontaneous activity and its modification by agents associated with parasympathetic and sympathetic nerve activity. A section of the rabbit small intestine is suspended in an organ bath, and the use of a pressure transducer and data-acquisition software allows the measurement of tension generated by the smooth muscle of intestinal walls. The application of the parasympathetic neurotransmitter ACh at varying concentrations allows students to observe an increase in intestinal smooth muscle tone with increasing concentrations of this muscarinic receptor agonist. Construction of a concentration-effect curve allows students to calculate an EC50 value for ACh and consider some basic concepts surrounding receptor occupancy and activation. Application of the hormone epinephrine to the precontracted intestine allows students to observe the inhibitory effects associated with sympathetic nerve activation. Introduction of the drug atropine to the preparation before a maximal concentration of ACh is applied allows students to observe the inhibitory effect of a competitive antagonist on the physiological response to a receptor agonist. The final experiment involves the observation of the depolarizing effect of K(+) on smooth muscle. Students are also invited to consider why the drugs atropine, codeine, loperamide, and botulinum toxin have medicinal uses in the management of gastrointestinal problems. PMID:26873897

  9. Effects of tracheal airway occlusion on hyoid muscle length and upper airway volume.

    PubMed

    van Lunteren, E; Haxhiu, M A; Cherniack, N S

    1989-12-01

    Complex relationships exist among electromyograms (EMGs) of the upper airway muscles, respective changes in muscle length, and upper airway volume. To test the effects of preventing lung inflation on these relationships, recordings were made of EMGs and length changes of the geniohyoid (GH) and sternohyoid (SH) muscles as well as of tidal changes in upper airway volume in eight anesthetized cats. During resting breathing, tracheal airway occlusion tended to increase the inspiratory lengthening of GH and SH. In response to progressive hypercapnia, the GH eventually shortened during inspiration in all animals; the extent of muscle shortening was minimally augmented by airway occlusion despite substantial increases in EMGs. SH lengthened during inspiration in six of eight animals under hypercapnic conditions, and in these cats lengthening was greater during airway occlusion even though EMGs increased. Despite the above effects on SH and GH length, upper airway tidal volume was increased significantly by tracheal occlusion under hypercapnic conditions. These data suggest that the thoracic and upper airway muscle reflex effects of preventing lung inflation during inspiration act antagonistically on hyoid muscle length, but, because of the mechanical arrangement of the hyoid muscles relative to the airway and thorax, they act agonistically to augment tidal changes in upper airway volume. The augmentation of upper airway tidal volume may occur in part as a result of the effects of thoracic movements being passively transmitted through the hyoid muscles. PMID:2606835

  10. Endothelial and smooth muscle histamine receptors

    SciTech Connect

    Blank, R.S.; Hollis, T.M.

    1986-03-01

    Histamine is produced within the vascular wall and mediates a variety of normal and pathologic vascular responses. The interaction of histamine with its vascular cell receptors has been shown to affect factors such as actin cable formation, cyclase activities, prostacyclin synthesis, cell motility, and proliferation. In addition, abundant evidence exists to implicate an arterial nascent histamine pool in the control of vessel wall permeability under conditions of stress and injury. However, endothelial and smooth muscle cell histamine receptors have been only incompletely characterized. The authors report here the time-dependent, saturable, and trypsin sensitive binding of /sup 3/H-histamine to the endothelial cell surface. The K/sub d/ for endothelial and smooth muscle cell histamine receptors are 0.70 and 2.80 ..mu..M respectively. Histamine binding to smooth muscle cells also exhibited saturation with concentrations of /sup 3/H-histamine up to 4 ..mu..M. While the smooth muscle cell H/sub 1/ receptor binding was negligible, the H/sub 2/ receptor appeared to represent a relatively low affinity, high capacity site for histamine binding. The uptake of /sup 3/H-histamine in both cell types displayed kinetics consistent with that of fluid-phase pinocytosis.

  11. On the thermodynamics of smooth muscle contraction

    NASA Astrophysics Data System (ADS)

    Stålhand, Jonas; McMeeking, Robert M.; Holzapfel, Gerhard A.

    2016-09-01

    Cell function is based on many dynamically complex networks of interacting biochemical reactions. Enzymes may increase the rate of only those reactions that are thermodynamically consistent. In this paper we specifically treat the contraction of smooth muscle cells from the continuum thermodynamics point of view by considering them as an open system where matter passes through the cell membrane. We systematically set up a well-known four-state kinetic model for the cross-bridge interaction of actin and myosin in smooth muscle, where the transition between each state is driven by forward and reverse reactions. Chemical, mechanical and energy balance laws are provided in local forms, while energy balance is also formulated in the more convenient temperature form. We derive the local (non-negative) production of entropy from which we deduce the reduced entropy inequality and the constitutive equations for the first Piola-Kirchhoff stress tensor, the heat flux, the ion and molecular flux and the entropy. One example for smooth muscle contraction is analyzed in more detail in order to provide orientation within the established general thermodynamic framework. In particular the stress evolution, heat generation, muscle shorting rate and a condition for muscle cooling are derived.

  12. Calcium Sensitization Mechanisms in Gastrointestinal Smooth Muscles

    PubMed Central

    Perrino, Brian A

    2016-01-01

    An increase in intracellular Ca2+ is the primary trigger of contraction of gastrointestinal (GI) smooth muscles. However, increasing the Ca2+ sensitivity of the myofilaments by elevating myosin light chain phosphorylation also plays an essential role. Inhibiting myosin light chain phosphatase activity with protein kinase C-potentiated phosphatase inhibitor protein-17 kDa (CPI-17) and myosin phosphatase targeting subunit 1 (MYPT1) phosphorylation is considered to be the primary mechanism underlying myofilament Ca2+ sensitization. The relative importance of Ca2+ sensitization mechanisms to the diverse patterns of GI motility is likely related to the varied functional roles of GI smooth muscles. Increases in CPI-17 and MYPT1 phosphorylation in response to agonist stimulation regulate myosin light chain phosphatase activity in phasic, tonic, and sphincteric GI smooth muscles. Recent evidence suggests that MYPT1 phosphorylation may also contribute to force generation by reorganization of the actin cytoskeleton. The mechanisms responsible for maintaining constitutive CPI-17 and MYPT1 phosphorylation in GI smooth muscles are still largely unknown. The characteristics of the cell-types comprising the neuroeffector junction lead to fundamental differences between the effects of exogenous agonists and endogenous neurotransmitters on Ca2+ sensitization mechanisms. The contribution of various cell-types within the tunica muscularis to the motor responses of GI organs to neurotransmission must be considered when determining the mechanisms by which Ca2+ sensitization pathways are activated. The signaling pathways regulating Ca2+ sensitization may provide novel therapeutic strategies for controlling GI motility. This article will provide an overview of the current understanding of the biochemical basis for the regulation of Ca2+ sensitization, while also discussing the functional importance to different smooth muscles of the GI tract. PMID:26701920

  13. Tracheobronchial smooth muscle atrophy and separation.

    PubMed

    Mehta, Atul C; Zaki, Khawaja Salman; Banga, Amit; Singh, Jarmanjeet; Gildea, Thomas R; Arrossi, Valeria

    2015-01-01

    We report a case series involving 4 patients with chronic obstructive pulmonary disease who were on an appropriate medical regimen including a high dose of inhaled corticosteroids (ICS). During bronchoscopy, patients were found to have an excessive dynamic collapse of the posterior wall and its separation from the ends of the adjacent cartilaginous rings. This was causing a near-total occlusion of the tracheal and bronchial lumen during exhalation, thereby presenting with an obstructive pattern on the pulmonary functions. We suspect that this was caused by the atrophy of the smooth muscles of the tracheobronchial wall. We reviewed the literature to explore the mechanisms causing atrophy of the bronchial smooth muscle, focusing on the potential role of long-term ICS use. PMID:26138002

  14. Dense-body aggregates as plastic structures supporting tension in smooth muscle cells.

    PubMed

    Zhang, Jie; Herrera, Ana M; Paré, Peter D; Seow, Chun Y

    2010-11-01

    The wall of hollow organs of vertebrates is a unique structure able to generate active tension and maintain a nearly constant passive stiffness over a large volume range. These properties are predominantly attributable to the smooth muscle cells that line the organ wall. Although smooth muscle is known to possess plasticity (i.e., the ability to adapt to large changes in cell length through structural remodeling of contractile apparatus and cytoskeleton), the detailed structural basis for the plasticity is largely unknown. Dense bodies, one of the most prominent structures in smooth muscle cells, have been regarded as the anchoring sites for actin filaments, similar to the Z-disks in striated muscle. Here, we show that the dense bodies and intermediate filaments formed cable-like structures inside airway smooth muscle cells and were able to adjust the cable length according to cell length and tension. Stretching the muscle cell bundle in the relaxed state caused the cables to straighten, indicating that these intracellular structures were connected to the extracellular matrix and could support passive tension. These plastic structures may be responsible for the ability of smooth muscle to maintain a nearly constant tensile stiffness over a large length range. The finding suggests that the structural plasticity of hollow organs may originate from the dense-body cables within the smooth muscle cells. PMID:20709732

  15. 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

  16. Mechanisms of Vascular Smooth Muscle Contraction and the Basis for Pharmacologic Treatment of Smooth Muscle Disorders

    PubMed Central

    Brozovich, F.V.; Nicholson, C.J.; Degen, C.V.; Gao, Yuan Z.; Aggarwal, M.

    2016-01-01

    The smooth muscle cell directly drives the contraction of the vascular wall and hence regulates the size of the blood vessel lumen. We review here the current understanding of the molecular mechanisms by which agonists, therapeutics, and diseases regulate contractility of the vascular smooth muscle cell and we place this within the context of whole body function. We also discuss the implications for personalized medicine and highlight specific potential target molecules that may provide opportunities for the future development of new therapeutics to regulate vascular function. PMID:27037223

  17. Length adaptation of smooth muscle contractile filaments in response to sustained activation.

    PubMed

    Stålhand, Jonas; Holzapfel, Gerhard A

    2016-05-21

    Airway and bladder smooth muscles are known to undergo length adaptation under sustained contraction. This adaptation process entails a remodelling of the intracellular actin and myosin filaments which shifts the peak of the active force-length curve towards the current length. Smooth muscles are therefore able to generate the maximum force over a wide range of lengths. In contrast, length adaptation of vascular smooth muscle has attracted very little attention and only a handful of studies have been reported. Although their results are conflicting on the existence of a length adaptation process in vascular smooth muscle, it seems that, at least, peripheral arteries and arterioles undergo such adaptation. This is of interest since peripheral vessels are responsible for pressure regulation, and a length adaptation will affect the function of the cardiovascular system. It has, e.g., been suggested that the inward remodelling of resistance vessels associated with hypertension disorders may be related to smooth muscle adaptation. In this study we develop a continuum mechanical model for vascular smooth muscle length adaptation by assuming that the muscle cells remodel the actomyosin network such that the peak of the active stress-stretch curve is shifted towards the operating point. The model is specialised to hamster cheek pouch arterioles and the simulated response to stepwise length changes under contraction. The results show that the model is able to recover the salient features of length adaptation reported in the literature. PMID:26925813

  18. In vivo recording of electrical activity of canine tracheal smooth muscle.

    PubMed

    Kondo, T; Tamura, K; Onoe, K; Takahira, H; Ohta, Y; Yamabayashi, H

    1992-01-01

    Electrical activity of the tracheal smooth muscle was studied using extracellular bipolar electrodes in 37 decerebrate, paralyzed, and mechanically ventilated dogs. A spontaneous oscillatory potential that consisted of a slow sinusoidal wave of 0.57 +/- 0.13 (SD) Hz mean frequency but lacked a fast spike component was recorded from 15 dogs. Lung collapse accomplished by bilateral pneumothoraxes evoked or augmented the slow potentials that were associated with an increase in tracheal muscle contraction in 26 dogs. This suggests that the inputs from the airway mechanoreceptors reflexly activate the tracheal smooth muscle cells. Bilateral vagal transection abolished both the spontaneous and the reflexly evoked slow waves and provided relaxation of the tracheal smooth muscle. Electrical stimulation of the distal nerve with a train pulse (0.5 ms, 1-30 Hz) evoked slow-wave oscillatory potentials accompanied by a contraction of the tracheal smooth muscle in all the experimental animals. Our observations in this in vivo study confirm that the electrical activity of tracheal smooth muscle consists of slow oscillatory potentials and that tracheal contraction is at least partly coupled to the slow-wave activity of the smooth muscle. PMID:1537706

  19. A role for p38(MAPK)/HSP27 pathway in smooth muscle cell migration.

    PubMed

    Hedges, J C; Dechert, M A; Yamboliev, I A; Martin, J L; Hickey, E; Weber, L A; Gerthoffer, W T

    1999-08-20

    Smooth muscle cells are exposed to growth factors and cytokines that contribute to pathological states including airway hyperresponsiveness, atherosclerosis, angiogenesis, smooth muscle hypertrophy, and hyperplasia. A common feature of several of these conditions is migration of smooth muscle beyond the initial boundary of the organ. Signal transduction pathways activated by extracellular signals that instigate migration are mostly undefined in smooth muscles. We measured migration of cultured tracheal myocytes in response to platelet-derived growth factor, interleukin-1beta, and transforming growth factor-beta. Cellular migration was blocked by SB203580, an inhibitor of p38(MAPK). Time course experiments demonstrated increased phosphorylation of p38(MAPK). Activation of p38(MAPK) resulted in the phosphorylation of HSP27 (heat shock protein 27), which may modulate F-actin polymerization. Inhibition of p38(MAPK) activity inhibited phosphorylation of HSP27. Adenovirus-mediated expression of activated mutant MAPK kinase 6b(E), an upstream activator for p38(MAPK), increased cell migration, whereas overexpression of p38alpha MAPK dominant negative mutant and an HSP27 phosphorylation mutant blocked cell migration completely. The results indicate that activation of the p38(MAPK) pathway by growth factors and proinflammatory cytokines regulates smooth muscle cell migration and may contribute to pathological states involving smooth muscle dysfunction. PMID:10446196

  20. Changes of smooth muscle contractile filaments in small bowel atresia

    PubMed Central

    Gfroerer, Stefan; Fiegel, Henning; Ramachandran, Priya; Rolle, Udo; Metzger, Roman

    2012-01-01

    AIM: To investigate morphological changes of intestinal smooth muscle contractile fibres in small bowel atresia patients. METHODS: Resected small bowel specimens from small bowel atresia patients (n = 12) were divided into three sections (proximal, atretic and distal). Standard histology hematoxylin-eosin staining and enzyme immunohistochemistry was performed to visualize smooth muscle contractile markers α-smooth muscle actin (SMA) and desmin using conventional paraffin sections of the proximal and distal bowel. Small bowel from age-matched patients (n = 2) undergoing Meckel’s diverticulum resection served as controls. RESULTS: The smooth muscle coat in the proximal bowel of small bowel atresia patients was thickened compared with control tissue, but the distal bowel was unchanged. Expression of smooth muscle contractile fibres SMA and desmin within the proximal bowel was slightly reduced compared with the distal bowel and control tissue. There were no major differences in the architecture of the smooth muscle within the proximal bowel and the distal bowel. The proximal and distal bowel in small bowel atresia patients revealed only minimal differences regarding smooth muscle morphology and the presence of smooth muscle contractile filament markers. CONCLUSION: Changes in smooth muscle contractile filaments do not appear to play a major role in postoperative motility disorders in small bowel atresia. PMID:22791945

  1. 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

  2. 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

  3. 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

  4. 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

  5. Regeneration and Maintenance of Intestinal Smooth Muscle Phenotypes

    NASA Astrophysics Data System (ADS)

    Walthers, Christopher M.

    Tissue engineering is an emerging field of biomedical engineering that involves growing artificial organs to replace those lost to disease or injury. Within tissue engineering, there is a demand for artificial smooth muscle to repair tissues of the digestive tract, bladder, and vascular systems. Attempts to develop engineered smooth muscle tissues capable of contracting with sufficient strength to be clinically relevant have so far proven unsatisfactory. The goal of this research was to develop and sustain mature, contractile smooth muscle. Survival of implanted SMCs is critical to sustain the benefits of engineered smooth muscle. Survival of implanted smooth muscle cells was studied with layered, electrospun polycaprolactone implants with lasercut holes ranging from 0--25% porosity. It was found that greater angiogenesis was associated with increased survival of implanted cells, with a large increase at a threshold between 20% and 25% porosity. Heparan sulfate coatings improved the speed of blood vessel infiltration after 14 days of implantation. With these considerations, thicker engineered tissues may be possible. An improved smooth muscle tissue culture technique was utilized. Contracting smooth muscle was produced in culture by maintaining the native smooth muscle tissue organization, specifically by sustaining intact smooth muscle strips rather than dissociating tissue in to isolated smooth muscle cells. Isolated cells showed a decrease in maturity and contained fewer enteric neural and glial cells. Muscle strips also exhibited periodic contraction and regular fluctuation of intracellular calclium. The muscle strip maturity persisted after implantation in omentum for 14 days on polycaprolactone scaffolds. A low-cost, disposable bioreactor was developed to further improve maturity of cultured smooth muscle cells in an environment of controlled cyclical stress.The bioreactor consistently applied repeated mechanical strain with controllable inputs for strain

  6. O3-induced mucosa-linked airway muscle hyperresponsiveness in the guinea pig

    SciTech Connect

    Murlas, C.G.; Murphy, T.P.; Chodimella, V. )

    1990-07-01

    We investigated the effects of ozone exposure (3.0 ppm, 2 h) on the responsiveness of guinea pig airway muscle in vitro from animals developing bronchial hyperreactivity. Muscarinic reactivity in vivo was determined by measuring specific airway resistance (sRaw) in response to increasing concentrations of aerosolized acetylcholine (ACh) administered before and 30 min after exposure. Immediately after reactivity testing, multiple tracheal rings from ozone- and air-exposed animals were prepared and the contractile responses to increasing concentrations of substance P, ACh, or KCl were assessed in the presence of 10 microM indomethacin with or without 1 microM phosphoramidon, an inhibitor of neutral endopeptidase. Isometric force generation in vitro was measured on stimulation by cumulative concentrations of the agonists, and force generation (in g/cm2) was calculated after determination of muscle cross-sectional area. The smooth muscle of mucosa-intact airways from guinea pigs with ozone-induced bronchial hyper-reactivity proved to be hyperresponsive in vitro to substance P and ACh but not to KCl. Pretreatment with phosphoramidon abolished the increase in substance P responsiveness but had no effect on muscarinic hyperresponsiveness after ozone exposure. Furthermore, substance P responsiveness was not augmented in ozone-exposed airways in which the mucosa had been removed before testing in vitro. Likewise, muscarinic hyperresponsiveness was not present in ozone-exposed airways without mucosa. Our data indicate that airway smooth muscle responsiveness is increased in guinea pigs with ozone-induced bronchial hyperreactivity and suggest that this hyperresponsiveness may be linked to non-cyclooxygenase mucosa-derived factors.

  7. 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

  8. 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

  9. Nox regulation of smooth muscle contraction

    PubMed Central

    Ritsick, Darren R.; Edens, William A.; Finnerty, Victoria; Lambeth, J. David

    2007-01-01

    The catalytic subunit, gp91phox (a.k.a., Nox2) of the NADPH-oxidase of mammalian phagocytes is activated by microbes and immune mediators to produce large amounts of reactive oxygen species (ROS) which participate in microbial killing. Homologs of gp91phox, the Nox and Duox enzymes, were recently described in a range of organisms, including plants, vertebrates, and invertebrates such as Drosophila melanogaster. While their enzymology and cell biology is being extensively studied in many laboratories, little is known about in vivo functions of Noxes. Here, we establish and use an inducible system for RNAi to discover functions of dNox, an ortholog of human Nox5 in Drosophila. We report here that depletion of dNox in musculature causes retention of mature eggs within ovaries, leading to female sterility. In dNox-depleted ovaries and ovaries treated with a Nox inhibitor, muscular contractions induced by the neuropeptide proctolin are markedly inhibited. This functional defect results from a requirement for dNox for the proctolin-induced calcium flux in Drosophila ovaries. Thus, these studies demonstrate a novel biological role for Nox-generated ROS in mediating agonist-induced calcium flux and smooth muscle contraction. PMID:17561091

  10. 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

  11. Modeling the dispersion effects of contractile fibers in smooth muscles

    NASA Astrophysics Data System (ADS)

    Murtada, Sae-Il; Kroon, Martin; Holzapfel, Gerhard A.

    2010-12-01

    Micro-structurally based models for smooth muscle contraction are crucial for a better understanding of pathological conditions such as atherosclerosis, incontinence and asthma. It is meaningful that models consider the underlying mechanical structure and the biochemical activation. Hence, a simple mechanochemical model is proposed that includes the dispersion of the orientation of smooth muscle myofilaments and that is capable to capture available experimental data on smooth muscle contraction. This allows a refined study of the effects of myofilament dispersion on the smooth muscle contraction. A classical biochemical model is used to describe the cross-bridge interactions with the thin filament in smooth muscles in which calcium-dependent myosin phosphorylation is the only regulatory mechanism. A novel mechanical model considers the dispersion of the contractile fiber orientations in smooth muscle cells by means of a strain-energy function in terms of one dispersion parameter. All model parameters have a biophysical meaning and may be estimated through comparisons with experimental data. The contraction of the middle layer of a carotid artery is studied numerically. Using a tube the relationships between the internal pressure and the stretches are investigated as functions of the dispersion parameter, which implies a strong influence of the orientation of smooth muscle myofilaments on the contraction response. It is straightforward to implement this model in a finite element code to better analyze more complex boundary-value problems.

  12. 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.

  13. 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

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

    PubMed

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

    2016-09-01

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

  15. 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.

  16. Acute administration of ivacaftor to people with cystic fibrosis and a G551D-CFTR mutation reveals smooth muscle abnormalities

    PubMed Central

    Adam, Ryan J.; Hisert, Katherine B.; Dodd, Jonathan D.; Grogan, Brenda; Launspach, Janice L.; Barnes, Janel K.; Gallagher, Charles G.; Sieren, Jered P.; Gross, Thomas J.; Fischer, Anthony J.; Cavanaugh, Joseph E.; Hoffman, Eric A.; Singh, Pradeep K.; Welsh, Michael J.; McKone, Edward F.; Stoltz, David A.

    2016-01-01

    Background Airflow obstruction is common in cystic fibrosis (CF), yet the underlying pathogenesis remains incompletely understood. People with CF often exhibit airway hyperresponsiveness, CF transmembrane conductance regulator (CFTR) is present in airway smooth muscle (ASM), and ASM from newborn CF pigs has increased contractile tone, suggesting that loss of CFTR causes a primary defect in ASM function. We hypothesized that restoring CFTR activity would decrease smooth muscle tone in people with CF. Methods To increase or potentiate CFTR function, we administered ivacaftor to 12 adults with CF with the G551D-CFTR mutation; ivacaftor stimulates G551D-CFTR function. We studied people before and immediately after initiation of ivacaftor (48 hours) to minimize secondary consequences of CFTR restoration. We tested smooth muscle function by investigating spirometry, airway distensibility, and vascular tone. Results Ivacaftor rapidly restored CFTR function, indicated by reduced sweat chloride concentration. Airflow obstruction and air trapping also improved. Airway distensibility increased in airways less than 4.5 mm but not in larger-sized airways. To assess smooth muscle function in a tissue outside the lung, we measured vascular pulse wave velocity (PWV) and augmentation index, which both decreased following CFTR potentiation. Finally, change in distensibility of <4.5-mm airways correlated with changes in PWV. Conclusions Acute CFTR potentiation provided a unique opportunity to investigate CFTR-dependent mechanisms of CF pathogenesis. The rapid effects of ivacaftor on airway distensibility and vascular tone suggest that CFTR dysfunction may directly cause increased smooth muscle tone in people with CF and that ivacaftor may relax smooth muscle. Funding This work was funded in part from an unrestricted grant from the Vertex Investigator-Initiated Studies Program. PMID:27158673

  17. Caffeine relaxes smooth muscle through actin depolymerization.

    PubMed

    Tazzeo, Tracy; Bates, Genevieve; Roman, Horia Nicolae; Lauzon, Anne-Marie; Khasnis, Mukta D; Eto, Masumi; Janssen, Luke J

    2012-08-15

    Caffeine is sometimes used in cell physiological studies to release internally stored Ca(2+). We obtained evidence that caffeine may also act through a different mechanism that has not been previously described and sought to examine this in greater detail. We ruled out a role for phosphodiesterase (PDE) inhibition, since the effect was 1) not reversed by inhibiting PKA or adenylate cyclase; 2) not exacerbated by inhibiting PDE4; and 3) not mimicked by submillimolar caffeine nor theophylline, both of which are sufficient to inhibit PDE. Although caffeine is an agonist of bitter taste receptors, which in turn mediate bronchodilation, its relaxant effect was not mimicked by quinine. After permeabilizing the membrane using β-escin and depleting the internal Ca(2+) store using A23187, we found that 10 mM caffeine reversed tone evoked by direct application of Ca(2+), suggesting it functionally antagonizes the contractile apparatus. Using a variety of molecular techniques, we found that caffeine did not affect phosphorylation of myosin light chain (MLC) by MLC kinase, actin-filament motility catalyzed by MLC kinase, phosphorylation of CPI-17 by either protein kinase C or RhoA kinase, nor the activity of MLC-phosphatase. However, we did obtain evidence that caffeine decreased actin filament binding to phosphorylated myosin heads and increased the ratio of globular to filamentous actin in precontracted tissues. We conclude that, in addition to its other non-RyR targets, caffeine also interferes with actin function (decreased binding by myosin, possibly with depolymerization), an effect that should be borne in mind in studies using caffeine to probe excitation-contraction coupling in smooth muscle. PMID:22683573

  18. Smooth muscle signalling pathways in health and disease

    PubMed Central

    Kim, H R; Appel, S; Vetterkind, S; Gangopadhyay, S S; Morgan, K G

    2008-01-01

    Smooth muscle contractile activity is a major regulator of function of the vascular system, respiratory system, gastrointestinal system and the genitourinary systems. Malfunction of contractility in these systems leads to a host of clinical disorders, and yet, we still have major gaps in our understanding of the molecular mechanisms by which contractility of the differentiated smooth muscle cell is regulated. This review will summarize recent advances in the molecular understanding of the regulation of smooth muscle myosin activity via phosphorylation/dephosphorylation of myosin, the regulation of the accessibility of actin to myosin via the actin-binding proteins calponin and caldesmon, and the remodelling of the actin cytoskeleton. Understanding of the molecular ‘players’ should identify target molecules that could point the way to novel drug discovery programs for the treatment of smooth muscle disorders such as cardiovascular disease, asthma, functional bowel disease and pre-term labour. PMID:19120701

  19. Exposure of immature rats to hyperoxia increases tracheal smooth muscle stress generation in vitro.

    PubMed

    Hershenson, M B; Wylam, M E; Punjabi, N; Umans, J G; Schumacker, P T; Mitchell, R W; Solway, J

    1994-02-01

    Recently, we demonstrated that chronic exposure to hyperoxia causes in vivo airway muscarinic receptor hyperresponsiveness in the developing rat [Am. J. Physiol. 262 (Lung Cell. Mol. Physiol. 6): L263-L269, 1992]. To test whether airway cholinergic hyperresponsiveness might result from intrinsic alterations in smooth muscle contractility, we measured the effect of in vivo hyperoxia on the contractile force elicited by acetylcholine (ACh) of isometrically mounted tracheal rings in vitro. Tracheal rings were obtained from 3-wk-old rats exposed to air or to > 95% O2 for 8 days. Muscarinic responses were determined by measuring the force elicited by exposure to increasing concentrations of ACh. Responses were normalized to the morphometrically determined tracheal smooth muscle cross-sectional area in a plane perpendicular to the axis of force generation. In vivo O2 exposure significantly increased maximal ACh-induced stress generation (response to 10(-3) M ACh: air, 15.92 +/- 1.37 g/mm2; O2, 21.78 +/- 1.52 g/mm2; P = 0.010). The ACh-induced stress generation of cylinders from hyperoxic rats was substantially reduced by both epithelial removal and treatment with the cyclooxygenase inhibitor indomethacin. We conclude that in vivo hyperoxic exposure increases tracheal smooth muscle contractile function in vitro and that epithelium-derived prostaglandin(s) contributes to the observed increase in maximal contractile responsiveness. PMID:8175585

  20. 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.

  1. Transforming growth factor-beta as a differentiating factor for cultured smooth muscle cells.

    PubMed

    Gawaziuk, J P; X; Sheikh, F; Cheng, Z-Q; Cattini, P A; Stephens, N L

    2007-10-01

    The aim of the present study was to determine whether the development of supercontractile smooth muscle cells, contributing to the nonspecific hyperreactivity of airways in asthmatic patients, is due to transforming growth factor (TGF)-beta. In cultured smooth muscle cells starved by removal of 10% foetal bovine serum for 7 days, growth arrest was seen; 30% became elongated and demonstrated super contractility. Study of conditioned medium suggested that the differentiating factor was TGF-beta. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) was carried out on conditioned medium from the arrested cells. Two protein bands were identified as matrix metalloproteinase (MMP)-2 and TGF-beta1. To determine second messenger signalling by SMAD2, Western blotting and confocal microscopy were employed. Conditioned medium from arrested cultures showed the presence of MMP-2 and TGF-beta1, as revealed by SDS-PAGE; 68- and 25-kDa bands were seen. Differentiation was confirmed by upregulation of marker proteins, smooth muscle type myosin heavy chain and myosin light chain kinase. Confirmation was obtained by downregulating these proteins with decorin treatment, which reduces the levels of active TGF-beta and an adenoviral dominant-negative vector coding for a mutated type II TGF-beta-receptor. Activation of second messenger signalling was demonstrated immunocytochemically by the presence of phosphorylated SMAD2 and SMAD4. Transforming growth factor-beta is likely to be the differentiating factor responsible for the development of these supercontractile smooth muscle cells. The development of such cells in vivo after cessation of an asthmatic attack could contribute to the nonspecific hyperreactivity of airways seen in patients. PMID:17596270

  2. Ablation of smooth muscle myosin heavy chain SM2 increases smooth muscle contraction and results in postnatal death in mice.

    PubMed

    Chi, Mei; Zhou, Yingbi; Vedamoorthyrao, Srikanth; Babu, Gopal J; Periasamy, Muthu

    2008-11-25

    The physiological relevance of smooth muscle myosin isoforms SM1 and SM2 has not been understood. In this study we generated a mouse model specifically deficient in SM2 myosin isoform but expressing SM1, using an exon-specific gene targeting strategy. The SM2 homozygous knockout (SM2(-/-)) mice died within 30 days after birth, showing pathologies including segmental distention of alimentary tract, retention of urine in renal pelvis, distension of bladder, and the development of end-stage hydronephrosis. In contrast, the heterozygous (SM2(+/-)) mice appeared normal and reproduced well. In SM2(-/-) bladder smooth muscle the loss of SM2 myosin was accompanied by a concomitant down-regulation of SM1 and a reduced number of thick filaments. However, muscle strips from SM2(-/-) bladder showed increased contraction to K(+) depolarization or in response to M3 receptor agonist Carbachol. An increase of contraction was also observed in SM2(-/-) aorta. However, the SM2(-/-) bladder was associated with unaltered regulatory myosin light chain (MLC20) phosphorylation. Moreover, other contractile proteins, such as alpha-actin and tropomyosin, were not altered in SM2(-/-) bladder. Therefore, the loss of SM2 myosin alone could have induced hypercontractility in smooth muscle, suggesting that distinctly from SM1, SM2 may negatively modulate force development during smooth muscle contraction. Also, because SM2(-/-) mice develop lethal multiorgan dysfunctions, we propose this regulatory property of SM2 is essential for normal contractile activity in postnatal smooth muscle physiology. PMID:19011095

  3. 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

  4. 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

  5. Muscarinic receptor size on smooth muscle cells and membranes

    SciTech Connect

    Collins, S.M.; Jung, C.Y.; Grover, A.K.

    1986-08-01

    The loss of (/sup 3/H)quinuclidinyl benzilate ((/sup 3/H)QNB) binding following high-energy radiation was used to compare the muscarinic receptor size on single smooth muscle cells isolated by collagenase digestion from the canine stomach and on plasma membranes derived from intact gastric smooth muscle without exposure to exogenous proteolysis. Radiation inactivation of galactose oxidase (68 kdaltons), yeast alcohol dehydrogenase (160 kdaltons), and pyruvate kinase (224 kdaltons) activities were used as molecular-weight standards. Radiation inactivation of (/sup 3/H)QNB binding to rat brain membranes, which gave a target size of 86 kdaltons, served as an additional control. In isolated smooth muscle cells, the calculated size of the muscarinic receptor was 80 +/- 8 kdaltons. In contrast, in a smooth muscle enriched plasma membrane preparation, muscarinic receptor size was significantly smaller at 45 +/- 3 kdaltons. Larger molecular sizes were obtained either in the presence of protease inhibitors (62 +/- 4 kdaltons) or by using a crude membrane preparation of gastric smooth muscle 86 +/- 7 kdaltons).

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

    PubMed Central

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

    2016-01-01

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

  7. Inhibitory action of relaxin on human cervical smooth muscle.

    PubMed

    Norström, A; Bryman, I; Wiqvist, N; Sahni, S; Lindblom, B

    1984-09-01

    The influence of purified porcine relaxin on contractility of human cervical smooth muscle was investigated in vitro. Strips of cervical tissue were obtained by needle biopsy from pregnant and nonpregnant women and were mounted in a superfused organ chamber for isometric measurement of contractile activity. Relaxin (0.005-25 micrograms/ml) inhibited the spontaneous contractions in cervical strips from 18% of nonpregnant, 68% of early pregnant, and in 100% of term pregnant women. These results indicate that relaxin has an inhibitory action on cervical smooth muscle and that this effect is more constantly detected as pregnancy proceeds. PMID:6746858

  8. Histochemical properties of upper airway muscles: comparison of dilator and nondilator muscles.

    PubMed

    Bracher, A; Coleman, R; Schnall, R; Oliven, A

    1997-05-01

    The upper airway dilator muscles (UADMs) represent a subgroup of muscles in the pharyngeal area which, in addition to their roles in mastication, vocalization, etc., also have an important respiratory function. Failure of these muscles to maintain upper airway patency during sleep is important in the development of the obstructive sleep apnoea syndrome. In the present study, we evaluated the histochemical properties of the UADMs and compared them to those of neighbouring muscles without respiratory functions, and to the diaphragm, to determine whether the UADMs are specifically adapted to their respiratory role. Our results, both in dogs and rats, indicate that the dilator and nondilator upper airway muscles are similar and differ from the diaphragm. In rats, there were significantly less type I fibres (<12% as compared to 42% for the diaphragm) and more type IIb fibres (39-67% as compared to 27% for the diaphragm). A similar pattern was seen in dogs: type I fibres <38% as compared to 46% for the diaphragm, and type IIb fibres, 29-35% as compared to 10% for the diaphragm. These findings suggest that the upper airway dilator muscles are not specifically designed for their respiratory role. They may fail in the presence of increased loads, often encountered in patients with obstructive sleep apnoea, unless appropriate adaptive structural changes take place. PMID:9163636

  9. Effect of gamma-aminobutyric acid on neurally mediated contraction of guinea pig trachealis smooth muscle.

    PubMed

    Tamaoki, J; Graf, P D; Nadel, J A

    1987-10-01

    To determine whether gamma-aminobutyric acid (GABA) affects the contractile properties of airway smooth muscle and, if so, what the mechanism of action is, the authors studied guinea pig tracheal rings under isometric conditions in vitro. GABA and related substances, baclofen and muscimol, had no effect on the resting tension but reversibly depressed contractions induced by electrical field stimulation in a dose-dependent fashion, IC50 values (mean +/- S.E.) being 5.6 +/- 1.4 X 10(-6) M, 6.8 +/- 0.9 X 10(-6) M and 8.5 +/- 1.5 X 10(-5) M, respectively. In contrast, GABA did not alter the response to exogenous acetylcholine or the nonadrenergic noncholinergic inhibitory component. Pretreatment of tissues with bicuculline antagonized the inhibitory effect of GABA as well as that of baclofen. This inhibitory effect was not modified by propranolol, phentolamine, hemicholinium-3 or naloxone, but it was blocked by the Cl channel blocker furosemide and by the substitution of external Cl. These results suggest that GABA decreases the contractile response of airway smooth muscle to cholinergic nerve stimulation by inhibiting the evoked release of acetylcholine and that this effect is exerted by activating Cl-dependent, bicuculline-sensitive GABA receptors. PMID:3668869

  10. Impact of obstructive apnea syndrome on upper airway respiratory muscles.

    PubMed

    Svanborg, Eva

    2005-07-28

    This article reviews studies of upper airway muscles in humans, with emphasis on muscle fiber structural and electrophysiological changes observed in patients with obstructive sleep apnea syndrome (OSAS). The concept of OSAS as a progressive disease is discussed and also possible causes. These include local nervous lesions in the upper airway, both motor and sensory. Previous muscle biopsy studies have given evidence for motor neuron lesions such as, e.g., the phenomenon of type grouping in histological sections. New data obtained with concentric needle EMG recordings from the palatopharyngeus muscles are also presented. In 10/12 OSAS patients there were typical findings indicating motor neuropathy (reduced EMG activity at maximal voluntary effort, long and polyphasic motor-unit potentials and, in two cases, spontaneous denervation activity), whereas such findings were only present in 3/15 patients with habitual snoring. This supports the hypothesis that progression from habitual snoring to the clinical disease of OSAS could be attributed to peripheral neurogenic lesions. PMID:16054444

  11. A smooth muscle-like origin for beige adipocytes.

    PubMed

    Long, Jonathan Z; Svensson, Katrin J; Tsai, Linus; Zeng, Xing; Roh, Hyun C; Kong, Xingxing; Rao, Rajesh R; Lou, Jesse; Lokurkar, Isha; Baur, Wendy; Castellot, John J; Rosen, Evan D; Spiegelman, Bruce M

    2014-05-01

    Thermogenic UCP1-positive cells, which include brown and beige adipocytes, transform chemical energy into heat and increase whole-body energy expenditure. Using a ribosomal profiling approach, we present a comprehensive molecular description of brown and beige gene expression from multiple fat depots in vivo. This UCP1-TRAP data set demonstrates striking similarities and important differences between these cell types, including a smooth muscle-like signature expressed by beige, but not classical brown, adipocytes. In vivo fate mapping using either a constitutive or an inducible Myh11-driven Cre demonstrates that at least a subset of beige cells arise from a smooth muscle-like origin. Finally, ectopic expression of PRDM16 converts bona fide vascular smooth muscle cells into Ucp1-positive adipocytes in vitro. These results establish a portrait of brown and beige adipocyte gene expression in vivo and identify a smooth muscle-like origin for beige cells. PMID:24709624

  12. Smooth Muscle-Mediated Connective Tissue Remodeling in Pulmonary Hypertension

    NASA Astrophysics Data System (ADS)

    Mecham, Robert P.; Whitehouse, Loren A.; Wrenn, David S.; Parks, William C.; Griffin, Gail L.; Senior, Robert M.; Crouch, Edmond C.; Stenmark, Kurt R.; Voelkel, Norbert F.

    1987-07-01

    Abnormal accumulation of connective tissue in blood vessels contributes to alterations in vascular physiology associated with disease states such as hypertension and atherosclerosis. Elastin synthesis was studied in blood vessels from newborn calves with severe pulmonary hypertension induced by alveolar hypoxia in order to investigate the cellular stimuli that elicit changes in pulmonary arterial connective tissue production. A two- to fourfold increase in elastin production was observed in pulmonary artery tissue and medial smooth muscle cells from hypertensive calves. This stimulation of elastin production was accompanied by a corresponding increase in elastin messenger RNA consistent with regulation at the transcriptional level. Conditioned serum harvested from cultures of pulmonary artery smooth muscle cells isolated from hypertensive animals contained one or more low molecular weight elastogenic factors that stimulated the production of elastin in both fibroblasts and smooth muscle cells and altered the chemotactic responsiveness of fibroblasts to elastin peptides. These results suggest that connective tissue changes in the pulmonary vasculature in response to pulmonary hypertension are orchestrated by the medial smooth muscle cell through the generation of specific differentiation factors that alter both the secretory phenotype and responsive properties of surrounding cells.

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

    PubMed

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

    2007-01-01

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

  14. Inhibition of tracheal smooth muscle contraction and myosin phosphorylation by ryanodine

    SciTech Connect

    Gerthoffer, W.T.; Murphey, K.A.; Khoyi, M.A.

    1988-08-01

    Previous studies have shown that muscarinic activation of airway smooth muscle in low Ca++ solutions increases myosin phosphorylation without increasing tension. Blocking Ca++ influx reduced phosphorylation, but not to basal levels. It was proposed that release of intracellular Ca++ contributed to dissociation of phosphorylation and contraction. To test this hypothesis the effects of ryanodine were studied under similar conditions. Ryanodine (10(-7) to 10(-5) M) antagonized caffeine-induced contraction of canine tracheal smooth muscle. Ryanodine also reduced carbachol-induced contractions and carbachol-induced myosin phosphorylation. The effect of ryanodine on potassium and serotonin-induced contractions was also investigated to test for a nonspecific inhibitory effect. In contrast to the effect on carbachol responses, ryanodine (10(-5) M) potentiated the contractile response to low concentrations of serotonin and potassium, but had no effect on the maximum response to either stimulant. Carbachol (10(-6) M) and ryanodine (10(-5) M) both significantly decreased /sup 45/Ca++ content of tracheal muscle. The effect of ryanodine and carbachol together on /sup 45/Ca++ content was not greater than either drug alone suggesting that ryanodine reduces the caffeine and carbachol responses by depleting releaseable Ca++ stores. Ryanodine significantly reduced Ca++-induced contraction and myosin phosphorylation in carbachol-stimulated muscle, suggesting that some of the Ca++ responsible for elevated phosphorylation is released from the sarcoplasmic reticulum.

  15. Estimates of activation in arterial smooth muscle.

    PubMed

    Singer, H A; Kamm, K E; Murphy, R A

    1986-09-01

    We have previously described the onset of a "latch" state in the swine carotid media after K+ depolarization. This state was characterized by maintained stress after a decrease in shortening velocities and in the level of cross-bridge phosphorylation. The present experiments were designed to determine whether there were changes in other mechanical properties in swine carotid media associated with the onset of the latch state. Medial strips (less than 500 microM thick), incubated in physiological salt solution (PSS) at 37 degrees C at their optimal length (Lo), were subjected to ramp stretches (5.86 mm/s) of 5% Lo. The active stress (Sa) response to stretch was computed by subtraction of the passive element contribution (as determined from identical stretches after 30 min incubation in Ca2+-free PSS) from the total response in the activated muscle. Transitions in the total and active stress responses to stretch were observed in strips stimulated with 109 mM K+ for 1 min or longer and were interpreted as yielding of the contractile apparatus. Active dynamic stiffness (dS/dLo) calculated from the initial 1% Lo portion of the stretch response, correlated linearly with active stress over a wide range. Maximal stress and dynamic stiffness were reached by 1 min and were maintained for at least 30 min in K+-depolarized preparations. However, yield stress increased significantly between 1 and 10 min, and there was a large increase in the length at which yield was observed (1.09 +/- 0.06 to 1.86 +/- 0.10% Lo; n = 9). These increases were maintained between 10 and 30 min.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3752237

  16. Effect of gender on rat upper airway muscle contractile properties.

    PubMed

    Cantillon, D; Bradford, A

    1998-08-01

    Obstructive sleep apnoea arises due to upper airway (UA) collapse which is normally counteracted by contraction of UA muscles such as the sternohyoids and geniohyoids. The disorder has a marked male predominance but the effect of gender on UA muscle contractile properties is unknown and these properties have not been compared for the sternohyoid and geniohyoid muscles in the same species. Isometric contractile characteristics were determined using strips of sternohyoid and geniohyoid muscle from male and female rats in Krebs solution at 30 degrees C. For both muscles, there were no differences between male and female contractile kinetics, twitch or tetanic tension, tension-length or tension-frequency relationship or endurance. In both males and females, sternohyoid twitch and tetanic tension was greater than geniohyoid. Sternohyoid endurance was less than geniohyoid but contractile kinetics, tension-length and tension-frequency relationships were similar. Therefore, gender does not affect UA muscle contractile properties and sternohyoid tension is greater and endurance less than that of the geniohyoid. PMID:9832233

  17. A modified force-velocity equation for smooth muscle contraction.

    PubMed

    Wang, J; Jiang, H; Stephens, N L

    1994-01-01

    It has been suggested that in skeletal muscle the force-velocity relationship may not be a simple hyperbolic one, as defined by Hill's equation. To determine whether smooth muscle demonstrated the same properties, quick-release force-velocity curves were obtained from canine tracheal smooth muscle. The results showed that the observed data points for tracheal smooth muscle systematically deviated from a hyperbola. Such deviation occurred at values of force (P) approaching maximum isometric force (Po) for curves elicited by quick release at 2 and 10 s in the course of isometric contractions. Shortening velocities under a given afterload were overestimated at the high-force end (P > 75% Po) by Hill's equation; this implied that a relationship more complex than a simple hyperbola was involved at high loads. We next focused on finding an equation to also fit those directly measured data points that did not conform to a hyperbola. Our rationale in developing the equation was that a plot of the linearized transform of Hill's equation should yield a straight line over the entire range of loads at which velocities were measured. The plot demonstrated that, in the low-load high-velocity portion of the curve, a peak value was reached at 70-80% Po, which decreased as load increased in the high-load low-velocity portion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8175513

  18. Increased smooth muscle contractility in mice deficient for neuropilin 2.

    PubMed

    Bielenberg, Diane R; Seth, Abhishek; Shimizu, Akio; Pelton, Kristine; Cristofaro, Vivian; Ramachandran, Aruna; Zwaans, Bernadette M M; Chen, Cheng; Krishnan, Ramaswamy; Seth, Meetu; Huang, Lin; Takashima, Seiji; Klagsbrun, Michael; Sullivan, Maryrose P; Adam, Rosalyn M

    2012-08-01

    Neuropilins (NRPs) are transmembrane receptors that bind class 3 semaphorins and VEGF family members to regulate axon guidance and angiogenesis. Although expression of NRP1 by vascular smooth muscle cells (SMCs) has been reported, NRP function in smooth muscle (SM) in vivo is unexplored. Using Nrp2(+/LacZ) and Nrp2(+/gfp) transgenic mice, we observed robust and sustained expression of Nrp2 in the SM compartments of the bladder and gut, but no expression in vascular SM, skeletal muscle, or cardiac muscle. This expression pattern was recapitulated in vitro using primary human SM cell lines. Alterations in cell morphology after treatment of primary visceral SMCs with the NRP2 ligand semaphorin-3F (SEMA3F) were accompanied by inhibition of RhoA activity and myosin light chain phosphorylation, as well as decreased cytoskeletal stiffness. Ex vivo contractility testing of bladder muscle strips exposed to electrical stimulation or soluble agonists revealed enhanced tension generation of tissues from mice with constitutive or SM-specific knockout of Nrp2, compared with controls. Mice lacking Nrp2 also displayed increased bladder filling pressures, as assessed by cystometry in conscious mice. Together, these findings identify Nrp2 as a mediator of prorelaxant stimuli in SMCs and suggest a novel function for Nrp2 as a regulator of visceral SM contractility. PMID:22688055

  19. Human vascular smooth muscle cells express a urate transporter.

    PubMed

    Price, Karen L; Sautin, Yuri Y; Long, David A; Zhang, Li; Miyazaki, Hiroki; Mu, Wei; Endou, Hitoshi; Johnson, Richard J

    2006-07-01

    An elevated serum uric acid is associated with the development of hypertension and renal disease. Renal regulation of urate excretion is largely controlled by URAT1 (SLC22A12), a member of the organic anion transporter superfamily. This study reports the specific expression of URAT1 on human aortic vascular smooth muscle cells, as assessed by reverse transcription-PCR and Western blot analysis. Expression of URAT1 was localized to the cell membrane. Evidence that the URAT1 transporter was functional was provided by the finding that uptake of 14C-urate was significantly inhibited in the presence of probenecid, an organic anion transporter inhibitor. It is proposed that URAT1 may provide a mechanism by which uric acid enters the human vascular smooth muscle cell, a finding that may be relevant to the role of uric acid in cardiovascular disease. PMID:16775029

  20. Smooth muscle and skeletal muscle myosins produce similar unitary forces and displacements in the laser trap.

    PubMed Central

    Guilford, W H; Dupuis, D E; Kennedy, G; Wu, J; Patlak, J B; Warshaw, D M

    1997-01-01

    Purified smooth muscle myosin in the in vitro motility assay propels actin filaments at 1/10 the velocity, yet produces 3-4 times more force than skeletal muscle myosin. At the level of a single myosin molecule, these differences in force and actin filament velocity may be reflected in the size and duration of single motion and force-generating events, or in the kinetics of the cross-bridge cycle. Specifically, an increase in either unitary force or duty cycle may explain the enhanced force-generating capacity of smooth muscle myosin. Similarly, an increase in attached time or decrease in unitary displacement may explain the reduced actin filament velocity of smooth muscle myosin. To discriminate between these possibilities, we used a laser trap to measure unitary forces and displacements from single smooth and skeletal muscle myosin molecules. We analyzed our data using mean-variance analysis, which does not rely on scoring individual events by eye, and emphasizes periods in the data with constant properties. Both myosins demonstrated multiple but similar event populations with discrete peaks at approximately +11 and -11 nm in displacement, and 1.5 and 3.5 pN in force. Mean attached times for smooth muscle myosin were longer than for skeletal-muscle myosin. These results explain much of the difference in actin filament velocity between these myosins, and suggest that an increased duty cycle is responsible for the enhanced force-generating capacity of smooth over skeletal-muscle myosin. Images FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:9138552

  1. Focal Ca2+ transient detection in smooth muscle.

    PubMed

    Young, John S; Amos, Robert J; Brain, Keith L

    2009-01-01

    Ca2+ imaging of smooth muscle provides insight into cellular mechanisms that may not result in changes of membrane potential, such as the release of Ca2+ from internal stores, and allows multiple cells to be monitored simultaneously to assess, for example, coupling in syncytial tissue. Subcellular Ca2+ transients are common in smooth muscle, yet are difficult to measure accurately because of the problems caused by their stochastic occurrence, over an often wide field of view, in an organ that it prone to contract. To overcome this problem, we've developed a series of imaging protocols and analysis routines to acquire and then analyse, in an automated fashion, the frequency, location and amplitude of such events. While this approach may be applied in other contexts, our own work involves the detection of local purinergic Ca2+ transients for locating transmitter release with submicron resolution. ATP is released as a cotransmitter from autonomic nerves, where it binds to P2X1 receptors on the smooth muscle of the detrusor and vas deferens. Ca2+ enters the smooth muscle, resulting in purinergic neuroeffector Ca2+ transients (NCTs). The focal Ca2+ transients allow the optical monitoring of neurotransmitter release in a manner that has many advantages over electrophysiology. Apart from the greatly improved spatial resolution, optical recording has the additional advantage of allowing the recording of transmitter release from many distinguishable sites simultaneously. Furthermore, the optical plane of focus is easier to maintain or correct during long recording series than is the repositioning of an intracellular sharp microelectrode. In summary, a method for imaging of Ca2+ fluorescence is outlined which details the preparation of tissue, and the acquisition and analysis of data. We outline the use of several scripts for the analysis of such Ca2+ transients. PMID:19564842

  2. Smooth muscle FGF/TGFβ cross talk regulates atherosclerosis progression.

    PubMed

    Chen, Pei-Yu; Qin, Lingfeng; Li, Guangxin; Tellides, George; Simons, Michael

    2016-01-01

    The conversion of vascular smooth muscle cells (SMCs) from contractile to proliferative phenotype is thought to play an important role in atherosclerosis. However, the contribution of this process to plaque growth has never been fully defined. In this study, we show that activation of SMC TGFβ signaling, achieved by suppression of SMC fibroblast growth factor (FGF) signaling input, induces their conversion to a contractile phenotype and dramatically reduces atherosclerotic plaque size. The FGF/TGFβ signaling cross talk was observed in vitro and in vivo In vitro, inhibition of FGF signaling increased TGFβ activity, thereby promoting smooth muscle differentiation and decreasing proliferation. In vivo, smooth muscle-specific knockout of an FGF receptor adaptor Frs2α led to a profound inhibition of atherosclerotic plaque growth when these animals were crossed on Apoe(-/-) background and subjected to a high-fat diet. In particular, there was a significant reduction in plaque cellularity, increase in fibrous cap area, and decrease in necrotic core size. In agreement with these findings, examination of human coronary arteries with various degrees of atherosclerosis revealed a strong correlation between the activation of FGF signaling, loss of TGFβ activity, and increased disease severity. These results identify SMC FGF/TGFβ signaling cross talk as an important regulator of SMC phenotype switch and document a major contribution of medial SMC proliferation to atherosclerotic plaque growth. PMID:27189169

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

    PubMed

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

    2016-04-01

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

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

    SciTech Connect

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

    2008-02-01

    Lysyl oxidase is required for the normal biosynthesis and maturation of collagen and elastin. It is expressed by vascular smooth muscle cells, and its increased expression has been previously found in atherosclerosis and in models of balloon angioplasty. The lysyl oxidase propeptide (LOX-PP) has more recently been found to have biological activity as a tumor suppressor, and it inhibits Erk1/2 Map kinase activation. We reasoned that LOX-PP may have functions in normal non-transformed cells. We, therefore, investigated its effects on smooth muscle cells, focusing on important biological processes mediated by Erk1/2-dependent signaling pathways including proliferation and matrix metalloproteinase-9 (MMP-9) expression. In addition, we investigated whether evidence for accumulation of LOX-PP could be found in vivo in a femoral artery injury model. Recombinant LOX-PP was expressed and purified, and was found to inhibit primary rat aorta smooth muscle cell proliferation and DNA synthesis by more than 50%. TNF-{alpha}-stimulated MMP-9 expression and Erk1/2 activation were both significantly inhibited by LOX-PP. Immunohistochemistry studies carried out with affinity purified anti-LOX-PP antibody showed that LOX-PP epitopes were expressed at elevated levels in vascular lesions of injured arteries. These novel data suggest that LOX-PP may provide a feedback control mechanism that serves to inhibit properties associated with the development of vascular pathology.

  5. Smooth muscle titin forms in vitro amyloid aggregates.

    PubMed

    Bobylev, Alexandr G; Galzitskaya, Oxana V; Fadeev, Roman S; Bobyleva, Liya G; Yurshenas, Darya A; Molochkov, Nikolay V; Dovidchenko, Nikita V; Selivanova, Olga M; Penkov, Nikita V; Podlubnaya, Zoya A; Vikhlyantsev, Ivan M

    2016-07-01

    Amyloids are insoluble fibrous protein aggregates, and their accumulation is associated with amyloidosis and many neurodegenerative diseases, including Alzheimer's disease. In the present study, we report that smooth muscle titin (SMT; 500 kDa) from chicken gizzard forms amyloid aggregates in vitro This conclusion is supported by EM data, fluorescence analysis using thioflavin T (ThT), Congo red (CR) spectroscopy and X-ray diffraction. Our dynamic light scattering (DLS) data show that titin forms in vitro amyloid aggregates with a hydrodynamic radius (Rh) of approximately 700-4500 nm. The initial titin aggregates with Rh approximately 700 nm were observed beyond first 20 min its aggregation that shows a high rate of amyloid formation by this protein. We also showed using confocal microscopy the cytotoxic effect of SMT amyloid aggregates on smooth muscle cells from bovine aorta. This effect involves the disorganization of the actin cytoskeleton and result is cell damage. Cumulatively, our results indicate that titin may be involved in generation of amyloidosis in smooth muscles. PMID:27129292

  6. Ultrastructural Changes of the Smooth Muscle in Esophageal Atresia.

    PubMed

    Al-Shraim, Mubarak M; Eid, Refaat A; Musalam, Adel Osman; Radad, Khaled; Ibrahim, Ashraf H M; Malki, Talal A

    2015-01-01

    Esophageal atresia (EA) with or without tracheo-esophageal fistula (TEF) is a relatively rare congenital anomaly. Despite the advances in the management techniques and neonatal intensive care, esophageal dysmotility remains a very common problem following EA/TEF repair. Our current study aimed to describe the most significant ultrastructural changes of the smooth muscle cells (SMCs) trying to highlight some of the underlying mechanisms of esophageal dysmotility following EA/TEF repair. Twenty-three biopsies were obtained from the tip of the lower esophageal pouch (LEP) of 23 patients during primary repair of EA/TEF. Light microscopic examination was performed with hematoxylin and eosin (HE), and Van Gieson's stains. Ultrastructural examination was done using transmission electron microscopy (TEM). Histopathological examination showed distortion of smooth muscle layer and deposition of an abundant amount of fibrous tissue in-between smooth muscles. Using TEM, SMCs exhibited loss of the cell-to-cell adhesion, mitochondrial vacuolation, formation of myelin figures, and apoptotic fragmentation. There were also plasmalemmal projections and formation of ghost bodies. Interestingly, SMCs were found extending pseudopodia-like projections around adjacent collagen fibers. Engulfed collagen fibers by SMCs underwent degradation within autophagic vacuoles. Degeneration of SMCs and deposition of abundant extracellular collagen fibers are prominent pathological changes in LEP of EA/TEF. These changes might contribute to the pathogenesis of esophageal dysmotility in patients who have survived EA/TEF. PMID:26548437

  7. Contribution of intestinal smooth muscle to Crohn's disease fibrogenesis.

    PubMed

    Severi, C; Sferra, R; Scirocco, A; Vetuschi, A; Pallotta, N; Pronio, A; Caronna, R; Di Rocco, G; Gaudio, E; Corazziari, E; Onori, P

    2014-01-01

    Mesenchymal cells transdifferentiation and extracellular matrix deposition are involved in the fibrotic process of Crohn's disease (CD). Mesenchymal smooth muscle cells (SMCs) de-differentiation, driven by Platelet-derived growth factor (PDGF) that counteracts Transforming growth factor (TGF-β) has been studied in vascular muscle. The role of SMCs in intestinal fibrogenesis is still not clearly elucidated. Aim of the study was to evaluate the possible myogenic contribution to CD fibrotic process through the comparative analysis of histological, morphometric and molecular alterations occurring in human smooth muscle. Full thickness specimens were obtained from CD (non-involved and stenotic tracts) and healthy (control) ileum. Tissues were processed for histological and immunohistochemical (IHC) analyses and SMCs were isolated from the muscularis propria for morphofunctional and molecular (qPCR) analyses. CD stenotic ileum showed a significant increased thickness of all layers compared to CD non-involved and control ileum. IHC revealed an overexpression of α-smooth muscle actin and collagens I-III throughout all intestinal layers only in stenotic tracts. The two growth factors, PDGF and TGF-β, showed a progressive increase in expression in the muscle layer from CD non-involved to stenotic tracts. Freshly isolated SMCs presented alterations in CD non-involved tracts that progressively increased in the stenotic tracts consisting in a statistical increase in mRNA encoding for PDGF-β and collagen III, paralleled to a decrease in TGF-β and Tribbles-like protein-3 mRNA, and altered morphofunctional parameters consisting in progressive decreases in cell length and contraction to acetylcholine. These findings indicate that intrinsic myogenic alterations occur in CD ileum, that they likely precede stricture formation, and might represent suitable new targets for anti-fibrotic interventions. PMID:25578979

  8. Effect of subchronic in vivo exposure to nitrogen dioxide on lung tissue inflammation, airway microvascular leakage, and in vitro bronchial muscle responsiveness in rats.

    PubMed Central

    Chitano, P; Rado, V; Di Stefano, A; Papi, A; Boniotti, A; Zancuoghi, G; Boschetto, P; Romano, M; Salmona, M; Ciaccia, A; Fabbri, L M; Mapp, C E

    1996-01-01

    OBJECTIVES: In a previous study on bronchoalveolar lavage fluid from rats exposed in vivo for seven days to 10 ppm nitrogen dioxide (NO2), it has been shown that there is an influx of macrophages into the airways. The present study investigated the effect of seven day exposure to 10 ppm NO2, on: (a) lung tissue inflammation and morphology; (b) airway microvascular leakage; (c) in vitro contractile response of main bronchi. METHODS: Lung tissue was studied by light microscopy, after fixing the lungs by inflation with 4% formalin at a pressure of 20 cm H2O. Microvascular leakage was measured by extravasation of Evans blue dye in the larynx, trachea, main bronchi, and intrapulmonary airways. Smooth muscle responsiveness was evaluated by concentration-responses curves to acetylcholine (10(-9)-10(-3) M), serotonin (10(-9)-10(-4) M), and voltage-response curves (12-28 V) to electrical field stimulation. RESULTS: Histology showed an increased total inflammation at the level of respiratory bronchioles and alveoli. No influx of inflammatory cells was found in the main bronchi. A loss of cilia in the epithelium of small airways and ectasia of alveolar capillaries was also found. By contrast, no alterations to microvascular permeability or modification of bronchial smooth muscle responsiveness was found. CONCLUSIONS: Subchronic exposure to 10 ppm NO2 causes airway inflammation and structural damage, but does not cause any persistent alteration to microvascular permeability or bronchial smooth muscle responsiveness in rats. Images Figure 1 PMID:8758032

  9. 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

  10. EDNRA variants associate with smooth muscle mRNA levels, cell proliferation rates, and cystic fibrosis pulmonary disease severity

    PubMed Central

    Darrah, Rebecca; McKone, Edward; O'Connor, Clare; Rodgers, Christine; Genatossio, Alan; McNamara, Sharon; Gibson, Ronald; Stuart Elborn, J.; Ennis, Madeleine; Gallagher, Charles G.; Kalsheker, Noor; Aitken, Moira; Wiese, Dawn; Dunn, John; Smith, Paul; Pace, Rhonda; Londono, Douglas; Goddard, Katrina A. B.; Knowles, Michael R.

    2010-01-01

    Airway inflammation and pulmonary disease are heterogeneous phenotypes in cystic fibrosis (CF) patients, even among patients with the same cystic fibrosis transmembrane conductance regulator (CFTR) genotype. Endothelin, a proinflammatory peptide and smooth muscle agonist, is increased in CF airways, potentially contributing to the pulmonary phenotype. Four cohorts of CF patients were screened for variants in endothelin pathway genes to determine whether any of these variants associated with pulmonary function. An initial cohort of 808 CF patients homozygous for the common CF mutation, ΔF508, showed significant association for polymorphisms in the endothelin receptor A gene, EDNRA (P = 0.04), but not in the related endothelin genes (EDN1, EDN2, EDN3, or EDNRB) or NOS1, NOS2A, or NOS3. Variants within EDNRA were examined in three additional cohorts of CF patients, 238 patients from Seattle, WA, 303 from Ireland and the U.K., and 228 from Cleveland, OH, for a total of 1,577 CF patients. The three additional groups each demonstrated a significant association between EDNRA 3′-untranslated region (UTR) variant rs5335 and pulmonary function (P = 0.002). At the molecular level, single nucleotide primer extension assays suggest that the effect of the variants is quantitative. EDNRA mRNA levels from cultured primary tracheal smooth muscle cells are greater for the allele that appears to be deleterious to lung function than for the protective allele, suggesting a mechanism by which increased receptor function is harmful to the CF airway. Finally, cell proliferation studies using human airway smooth muscle cells demonstrated that cells homozygous for the deleterious allele proliferate at a faster rate than those homozygous for the protective allele. PMID:20028935

  11. Hydrogen peroxide induced responses of cat tracheal smooth muscle cells

    PubMed Central

    Bauer, V; Oike, M; Tanaka, H; Inoue, R; Ito, Y

    1997-01-01

    The effects of hydrogen peroxide H2O2 (10−6 and 10−3 M) on membrane potential, membrane currents, intracellular calcium concentration, resting muscle tone and contractions elicited by electrical field stimulation (EFS) and carbachol were examined in cat tracheal strips and isolated smooth muscle cells. H2O2 (10−4 and 10−5 M) enhanced the amplitude of contractions and excitatory junction potentials (e.j.p.) evoked by EFS without changing muscle tone and resting membrane potential of the tracheal smooth muscle, and enhanced the contraction induced by carbachol (10−8 M). At an increased concentration (10−3 M), H2O2 elevated resting muscle tone and marginally hyperpolarized the membrane in the majority of the cells. In 51 out of 56 cells examined, H2O2 (10−6–10−3 M) elicited an outward current at a holding potential of −40 mV and enhanced the frequency of the spontaneous transient outward current (STOC). In 20 cells the outward current was preceded by a small inward current. In the other cells, H2O2 elicited only an inward current or did not affect the background current. In Ca2+ free solution the action of H2O2 on the resting muscle tone, STOCs, background current and on the current induced by ramp depolarization was significantly reduced. H2O2 (10−4 M) increased the intracellular ionized calcium concentration both in the absence and presence of external Ca2+. However, the effect developed faster and was of a higher amplitude in the presence of external Ca2+. These results suggest that H2O2 increases intracellular Ca2+, with a subsequent augmentation of stimulation-evoked contractions, and enhances Ca2+ and voltage-sensitive potassium conductance. PMID:9222542

  12. Kinematic MRI study of upper-airway biomechanics using electrical muscle stimulation

    NASA Astrophysics Data System (ADS)

    Brennick, Michael J.; Margulies, Susan S.; Ford, John C.; Gefter, Warren B.; Pack, Allan I.

    1997-05-01

    We have developed a new and powerful method to study the movement and function of upper airway muscles. Our method is to use direct electrical stimulation of individual upper airway muscles, while performing state of the art high resolution magnetic resonance imaging (MRI). We have adapted a paralyzed isolated UA cat model so that positive or negative static pressure in the UA can be controlled at specific levels while electrical muscle stimulation is applied during MRI. With these techniques we can assess the effect of muscle stimulation on airway cross-sectional area compliance and soft tissue motion. We are reporting the preliminary results and MRI techniques which have enabled us to examine changes in airway dimensions which result form electrical stimulation of specific upper airway dilator muscles. The results of this study will be relevant to the development of new clinical treatments for obstructive sleep apnea by providing new information as to exactly how upper airway muscles function to dilate the upper airway and the strength of stimulation required to prevent the airway obstruction when overall muscle tone may not be sufficient to maintain regular breathing.

  13. K(V)7 potassium channels: a new therapeutic target in smooth muscle disorders.

    PubMed

    Stott, Jennifer B; Jepps, Thomas A; Greenwood, Iain A

    2014-04-01

    Potassium channels are key regulators of smooth muscle tone, with increases in activity resulting in hyperpolarisation of the cell membrane, which acts to oppose vasoconstriction. Several potassium channels exist within smooth muscle, but the KV7 family of voltage-gated potassium channels have been identified as being crucial mediators of this process in a variety of smooth muscle. Recently, KV7 channels have been shown to be involved in the pathogenesis of hypertension, as well as being implicated in other smooth muscle disorders, providing a new and inviting target for smooth muscle disorders. PMID:24333708

  14. Bronchodilatory and B-adrenergic effects of methanolic and aqueous extracts of Althaea root on isolated tracheobronchial smooth rat muscle

    PubMed Central

    Alani, Behrang; Zare, Mohammad; Noureddini, Mahdi

    2015-01-01

    Background: The smooth muscle contractions of the tracheobronchial airways are mediated through the balance of adrenergic, cholinergic and peptidergic nervous mechanisms. This research was designed to determine the bronchodilatory and B-adrenergic effects of methanolic and aqueous extracts of root Althaea on the isolated tracheobronchial smooth muscle of the rat. Materials and Methods: In this experimental study, 116 tracheobronchial sections (5 mm) from 58 healthy male Sprague-Dawley rats were dissected and divided into 23 groups. The effect of methanolic and aqueous extracts of the root Althaea was assayed at different concentrations (0.2, 0.6, 2.6, 6.6, 14.6 μg/ml) and epinephrine (5 μm) in the presence and absence of propranolol (1 μM) under one g tension based on the isometric method. This assay was recorded in an organ bath containing Krebs-Henseleit solution for tracheobronchial smooth muscle contractions using potassium chloride (KCl) (60 mM) induction. Results: Epinephrine (5 μm) alone and root methanolic and aqueous extract concentrations (0.6-14.6 μg/ml) reduced tracheobronchial smooth muscle contractions induced using KCl (60 mM) in a dose dependent manner. Propranolol inhibited the antispasmodic effect of epinephrine on tracheobronchial smooth muscle contractions, but could not reduce the antispasmodic effect of the root extract concentrations. Conclusion: The methanolic and aqueous extracts of Althaea root inhibited the tracheobronchial smooth muscle contractions of rats in a dose dependent manner, but B-adrenergic receptors do not appear to engage in this process. Understanding the mechanism of this process can be useful in the treatment of pulmonary obstructive diseases like asthma. PMID:25879003

  15. Adaptive response of pulmonary arterial smooth muscle to length change.

    PubMed

    Syyong, Harley; Cheung, Christine; Solomon, Dennis; Seow, Chun Y; Kuo, Kuo H

    2008-04-01

    Hypervasoconstriction is associated with pulmonary hypertension and dysfunction of the pulmonary arterial smooth muscle (PASM) is implicated. However, relatively little is known about the mechanical properties of PASM. Recent advances in our understanding of plastic adaptation in smooth muscle may shed light on the disease mechanism. In this study, we determined whether PASM is capable of adapting to length changes (especially shortening) and regain its contractile force. We examined the time course of length adaptation in PASM in response to step changes in length and to length oscillations mimicking the periodic stretches due to pulsatile arterial pressure. Rings from sheep pulmonary artery were mounted on myograph and stimulated using electrical field stimulation (12-16 s, 20 V, 60 Hz). The length-force relationship was determined at L(ref) to 0.6 L(ref), where L(ref) was a reference length close to the in situ length of PASM. The response to length oscillations was determined at L(ref), after the muscle was subjected to length oscillation of various amplitudes for 200 s at 1.5 Hz. Release (or stretch) of resting PASM from L(ref) to 0.6 (and vice versa) was followed by a significant force recovery (73 and 63%, respectively), characteristic of length adaptation. All recoveries of force followed a monoexponential time course. Length oscillations with amplitudes ranging from 5 to 20% L(ref) caused no significant change in force generation in subsequent contractions. It is concluded that, like many smooth muscles, PASM possesses substantial capability to adapt to changes in length. Under pathological conditions, this could contribute to hypervasoconstriction in pulmonary hypertension. PMID:18218913

  16. Stimulant actions of volatile anaesthetics on smooth muscle

    PubMed Central

    Rang, H. P.

    1964-01-01

    A number of volatile anaesthetics, and some compounds synthesized in the search for new anaesthetics, have been tested on guinea-pig intestinal smooth muscle in vitro. All the compounds produced a contractile response. This effect did not correlate well with convulsant activity in vivo among the compounds tested. Two kinds of stimulant effect were distinguishable: (1) Rapid, transient contractions, abolished by cocaine or lachesine; most of the anaesthetics in clinical use had this action. (2) Slow, sustained contractions, unaffected by cocaine or lachesine; this effect predominated among the fluorinated ring compounds. Hexamethonium and mepyramine did not affect the contractile response to any of the compounds. The first type of effect presumably represents excitation of postganglionic nerve cells, while the second type is a direct action on the muscle cell. The action of perfluorobenzene, which is of the latter kind, was studied further. Adrenaline and lack of calcium diminished the contraction in parallel with the contraction to histamine, which suggests that the cell membrane was the site of action; in contrast to the stimulant action of histamine or acetylcholine, the effect was highly temperature-sensitive, being almost abolished by cooling to 32° C, and enhanced at 40° C. The depressant action of anaesthetics on smooth muscle is affected very little by temperature changes. These findings are discussed in relation to other observations which suggest a stimulant action of volatile anaesthetics on excitable tissues. Protein denaturation is tentatively suggested as a mechanism of action. PMID:14190470

  17. 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

  18. Ionic conductances regulating the excitability of colonic smooth muscles

    PubMed Central

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

    2012-01-01

    The tunica muscularis of the gastrointestinal (GI) tract contains two layers of smooth muscle cells (SMC) oriented perpendicular to each other. SMC express a variety of voltage-dependent and voltage-independent ionic conductance(s) that develop membrane potential and control excitability. Resting membrane potentials (RMP) vary through the GI tract but generally are within the range of −80 to −40mV. RMP sets the ‘gain’ of smooth muscle and regulates openings of voltage-dependent Ca2+ channels. A variety of K+ channels contribute to setting RMP of SMC. In most regions RMP is considerably less negative than the K+ equilibrium potential, due to a finely tuned balance between background K+ channels and non-selective cation channels (NSCC). Variations in expression patterns and openings of K+ channels and NSCC account for differences of the RMP in different regions of the GI tract. Smooth muscle excitability is also regulated by interstitial cells (interstitial cells of Cajal (ICC) and PDGFRα+ cells) that express additional conductances and are electrically coupled to SMC. Thus, ‘myogenic’ activity results from the integrated behavior of the SMC/ICC/PDGFRα+ cell (SIP) syncytium. Inputs from excitatory and inhibitory motor neurons are required to produce the complex motor patterns of the gut. Motor neurons innervate three cell-types in the SIP, and receptors, second messenger pathways and ion channels in these cells mediate post-junctional responses. Studies of isolated SIP cells have begun to unravel the mechanisms responsible for neural responses. This review discusses ion channels that set and regulate RMP of SIP cells and how neurotransmitters regulate membrane potential. PMID:22726670

  19. 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

  20. Epstein-Barr Virus-Associated Smooth Muscle Tumor.

    PubMed

    Dekate, Jyoti; Chetty, Runjan

    2016-07-01

    Immunodeficient individuals are prone to develop a number of opportunistic infections and unique neoplasms. Epstein-Barr virus-associated smooth muscle tumor is an uncommon neoplasm associated with immunodeficiency. It has been described in patients infected with human immunodeficiency virus, in the posttransplant setting, and in those with congenital immunodeficiency. Different anatomic sites can be involved by Epstein-Barr virus-associated smooth muscle tumor, and even multiple locations can contain these unique lesions within the same patient. The presence of variable numbers of intratumoral lymphocytes and primitive round cell areas are the unique defining features for this tumor. Histopathologic features may vary considerably in terms of cellular atypia, mitotic activity, and necrosis, with no correlation to the clinical behavior. Demonstration of Epstein-Barr virus infection by in situ hybridization within tumor cell remains critical for the diagnosis. The mechanism for Epstein-Barr virus infection of progenitor cells and neoplastic transformation has been an area of interest and conjecture. Different treatment strategies are proposed according to underlying disease status. This paper reviews the clinicopathologic features of this uncommon neoplasm with detailed discussion of the role of Epstein-Barr virus in the pathogenesis. PMID:27362573

  1. Calcium oscillations in human mesenteric vascular smooth muscle.

    PubMed

    Navarro-Dorado, Jorge; Garcia-Alonso, Mauricio; van Breemen, Cornelis; Tejerina, Teresa; Fameli, Nicola

    2014-02-28

    Phenylephrine (PE)-induced oscillatory fluctuations in intracellular Ca(2+) concentration ([Ca(2+)]i) of vascular smooth muscle have been observed in many blood vessels isolated from a wide variety of mammals. Paradoxically, until recently similar observations in humans have proven elusive. In this study, we report for the first time observations of adrenergically-stimulated [Ca(2+)]i oscillations in human mesenteric artery smooth muscle. In arterial segments preloaded with Fluo-4 AM and mounted on a myograph on the stage of a confocal microscope, we observed PE-induced oscillations in [Ca(2+)]i, which initiated and maintained vasoconstriction. These oscillations present some variability, possibly due to compromised health of the tissue. This view is corroborated by our ultrastructural analysis of the cells, in which we found only (5 ± 2)% plasma membrane-sarcoplasmic reticulum apposition, markedly less than measured in healthy tissue from laboratory animals. We also partially characterized the oscillations by using the inhibitory drugs 2-aminoethoxydiphenyl borate (2-APB), cyclopiazonic acid (CPA) and nifedipine. After PE contraction, all drugs provoked relaxation of the vessel segments, sometimes only partial, and reduced or inhibited oscillations, except CPA, which rarely caused relaxation. These preliminary results point to a potential involvement of the sarcoplasmic reticulum Ca(2+) and inositol 1,4,5-trisphosphate receptor (IP3R) in the maintenance of the Ca(2+) oscillations observed in human blood vessels. PMID:24508261

  2. Alpha-Smooth Muscle Actin Expression Upregulates Fibroblast Contractile Activity

    PubMed Central

    Hinz, Boris; Celetta, Giuseppe; Tomasek, James J.; Gabbiani, Giulio; Chaponnier, Christine

    2001-01-01

    To evaluate whether α-smooth muscle actin (α-SMA) plays a role in fibroblast contractility, we first compared the contractile activity of rat subcutaneous fibroblasts (SCFs), expressing low levels of α-SMA, with that of lung fibroblasts (LFs), expressing high levels of α-SMA, with the use of silicone substrates of different stiffness degrees. On medium stiffness substrates the percentage of cells producing wrinkles was similar to that of α-SMA–positive cells in each fibroblast population. On high stiffness substrates, wrinkle production was limited to a subpopulation of LFs very positive for α-SMA. In a second approach, we measured the isotonic contraction of SCF- and LF-populated attached collagen lattices. SCFs exhibited 41% diameter reduction compared with 63% by LFs. TGFβ1 increased α-SMA expression and lattice contraction by SCFs to the levels of LFs; TGFβ-antagonizing agents reduced α-SMA expression and lattice contraction by LFs to the level of SCFs. Finally, 3T3 fibroblasts transiently or permanently transfected with α-SMA cDNA exhibited a significantly higher lattice contraction compared with wild-type 3T3 fibroblasts or to fibroblasts transfected with α-cardiac and β- or γ-cytoplasmic actin. This took place in the absence of any change in smooth muscle or nonmuscle myosin heavy-chain expression. Our results indicate that an increased α-SMA expression is sufficient to enhance fibroblast contractile activity. PMID:11553712

  3. Relaxant effect of 6-deoxyclitoriacetal on smooth muscle preparations.

    PubMed

    Itthipanichpong, C; Ruangrungsi, N; Saibundasak, K

    2001-06-01

    The pharmacological effect of 6-deoxyclitoriacetal (6-DA), a rotenoid compound isolated from the roots of Clitoria macrophylla Wall. (Papilionaceae), was examined on different smooth muscle preparations. 6-Deoxyclitoriacetal 0.2 mg/ml produced a significant decrease in the spontaneous contraction of isolated rat uterus. It also suppressed the contraction induced by acetylcholine 5x10(-6) M and oxytocin 5x10(-3) IU/ml. The cumulative contractile responses of rat aortic strips caused by serotonin 10(-8)-10(-4) M and norepinephrine 10(-11)-10(-7) M were reduced by 6-DA 0.4 mg/ml. In calcium free Kreb's solution, 6-DA inhibited the aortic contraction produced by a cumulative dose of calcium chloride (0.1-30 mM). In guinea-pig ileum, 6-DA 0.15 mg/ml exerted the spasmolytic activity by inhibition of the contractile response evoked by various contractile agents e.g. acetylcholine 10(-9)-10(-5) M, serotonin 10(-9)-10(-5) M and histamine 10(-9)-10(-5) M. All of the results indicated that 6-DA could induce a smooth muscle relaxant effect by interference with intracellular calcium metabolism. PMID:11529336

  4. Pericytes are progenitors for coronary artery smooth muscle.

    PubMed

    Volz, Katharina S; Jacobs, Andrew H; Chen, Heidi I; Poduri, Aruna; McKay, Andrew S; Riordan, Daniel P; Kofler, Natalie; Kitajewski, Jan; Weissman, Irving; Red-Horse, Kristy

    2015-01-01

    Epicardial cells on the heart's surface give rise to coronary artery smooth muscle cells (caSMCs) located deep in the myocardium. However, the differentiation steps between epicardial cells and caSMCs are unknown as are the final maturation signals at coronary arteries. Here, we use clonal analysis and lineage tracing to show that caSMCs derive from pericytes, mural cells associated with microvessels, and that these cells are present in adults. During development following the onset of blood flow, pericytes at arterial remodeling sites upregulate Notch3 while endothelial cells express Jagged-1. Deletion of Notch3 disrupts caSMC differentiation. Our data support a model wherein epicardial-derived pericytes populate the entire coronary microvasculature, but differentiate into caSMCs at arterial remodeling zones in response to Notch signaling. Our data are the first demonstration that pericytes are progenitors for smooth muscle, and their presence in adult hearts reveals a new potential cell type for targeting during cardiovascular disease. PMID:26479710

  5. MURC deficiency in smooth muscle attenuates pulmonary hypertension

    PubMed Central

    Nakanishi, Naohiko; Ogata, Takehiro; Naito, Daisuke; Miyagawa, Kotaro; Taniguchi, Takuya; Hamaoka, Tetsuro; Maruyama, Naoki; Kasahara, Takeru; Nishi, Masahiro; Matoba, Satoaki; Ueyama, Tomomi

    2016-01-01

    Emerging evidence suggests that caveolin-1 (Cav1) is associated with pulmonary arterial hypertension. MURC (also called Cavin-4) is a member of the cavin family, which regulates caveolar formation and functions together with caveolins. Here, we show that hypoxia increased Murc mRNA expression in the mouse lung, and that Murc-null mice exhibited attenuation of hypoxia-induced pulmonary hypertension (PH) accompanied by reduced ROCK activity in the lung. Conditional knockout mice lacking Murc in smooth muscle also resist hypoxia-induced PH. MURC regulates the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) through Rho/ROCK signalling. Cav1 suppresses RhoA activity in PASMCs, which is reversed by MURC. MURC binds to Cav1 and inhibits the association of Cav1 with the active form of Gα13, resulting in the facilitated association of the active form of Gα13 with p115RhoGEF. These results reveal that MURC has a function in the development of PH through modulating Rho/ROCK signalling. PMID:27546070

  6. MicroRNAs Dynamically Remodel Gastrointestinal Smooth Muscle Cells

    PubMed Central

    Park, Chanjae; Yan, Wei; Ward, Sean M.; Hwang, Sung Jin; Wu, Qiuxia; Hatton, William J.; Park, Jong Kun; Sanders, Kenton M.; Ro, Seungil

    2011-01-01

    Smooth muscle cells (SMCs) express a unique set of microRNAs (miRNAs) which regulate and maintain the differentiation state of SMCs. The goal of this study was to investigate the role of miRNAs during the development of gastrointestinal (GI) SMCs in a transgenic animal model. We generated SMC-specific Dicer null animals that express the reporter, green fluorescence protein, in a SMC-specific manner. SMC-specific knockout of Dicer prevented SMC miRNA biogenesis, causing dramatic changes in phenotype, function, and global gene expression in SMCs: the mutant mice developed severe dilation of the intestinal tract associated with the thinning and destruction of the smooth muscle (SM) layers; contractile motility in the mutant intestine was dramatically decreased; and SM contractile genes and transcriptional regulators were extensively down-regulated in the mutant SMCs. Profiling and bioinformatic analyses showed that SMC phenotype is regulated by a complex network of positive and negative feedback by SMC miRNAs, serum response factor (SRF), and other transcriptional factors. Taken together, our data suggest that SMC miRNAs are required for the development and survival of SMCs in the GI tract. PMID:21533178

  7. Endothelin ETA receptor expression in human cerebrovascular smooth muscle cells.

    PubMed Central

    Yu, J. C.; Pickard, J. D.; Davenport, A. P.

    1995-01-01

    1. Endothelin (ET) has been implicated in cerebrovasospasm for example, following subarachnoid haemorrhage, and blocking the interaction of ET with its receptors on cerebral vessels, may be of therapeutic benefit. The aim of our study was to characterize endothelin receptor sub-types on medial smooth muscle cells of human cerebral vessels. Cultures of vascular smooth muscle cells were explanted from human cerebral resistance vessels and characterized as human brain smooth muscle cells (HBSMCs). 2. Over a 48 h incubation period, HBSMC cultures secreted comparable levels of immunoreactive (IR) big endothelin-1 (big ET-1) and IR endothelin (ET): 12.7 +/- 10.3 and 8.3 +/- 5.6 pmol/10(6) cells, respectively (mean +/- s.e. mean from three different individuals), into the culture medium. 3. Total RNA was extracted from cultures of human brain smooth muscle cells. Reverse-transcriptase polymerase chain reaction (RI-PCR) assays and subsequent product separation by agarose gel electrophoresis revealed single bands corresponding to the expected product sizes encoding cDNA for ETA (299 base pairs) and ETB (428 base pairs) (n = 3 different cultures). 4. Autoradiography demonstrated the presence of specific binding sites for [125I]-ET-1 which labels all ET receptors, and [125I]-PD151242, an ETA subtype-selective antagonist which exclusively labels ETA receptors, but no specific-binding was detected using ETB subtype-selective [125I]-BQ3020 (n = 3 different cultures, in duplicate). 5. In saturation binding assays, [123I]-ET-1 bound with high affinity: KD = 0.8 +/- 0.1 nM and Bmax = 690 +/- 108 fmol mg-1. A one-site fit was preferred and Hill slopes were close to unity over the concentration range (10(-12) to 10(-8) M). [125I]-PD151242 also bound with similar affinity: KD = 0.4 +/- 0.1 nM and Bmax = 388 +/- 68 fmol mg-1 (mean +/- s.e. mean, n = 3 different cultures). Again, a one-site fit was preferred and Hill slopes were close to unity over the concentration range. Unlabelled PD

  8. Role of magnesium in activation of smooth muscle.

    PubMed

    Paul, R J; Rüegg, J C

    1988-10-01

    We studied the effects of Mg2+-free solutions on isometric force (F0) and unloaded shortening velocity (Vus) in contractions elicited by Ca2+ or by ATP after thiophosphorylation by adenosine 5'-O-(3-thiotriphosphate (ATP gamma S) in chemically skinned guinea pig taenia coli smooth muscle. In Mg2+-free solutions, increasing Ca2+ did not increase Fo above resting levels. At the peak of a control contraction elicited by Ca2+, transfer to Mg2+-free (but Ca2+-containing) solutions resulted in a rapid relaxation and concomitant dephosphorylation of myosin. After ATP gamma S, a contracture required neither Mg2+ nor Ca2+ in the solutions for control levels of Fo. Vus in the Mg2+-free solutions after ATP gamma S was approximately 50% of control and could be restored to near control levels by addition of Mg2+ but not Ca2+. After ATP gamma S, pretreatment with 4 mM EDTA and contracture in 0.1 mM EDTA-containing solutions decreased Fo to 70-80% of control and Vus to 50-60% of control. Our results suggest that the relatively high requirement for Mg2+ for contraction in skinned smooth muscle largely reflects the Mg2+ dependence of myosin kinase and not for actin-myosin interaction. The dependence of Fo on Mg2+ (in the presence of excess ATP) in taenia coli is less than that reported for skeletal muscle. Appreciable force can be maintained with no added Mg2+ in the presence of 4 mMEDTA, and thus it appears that ATP4- can be a substrate for contraction after ATP gamma S treatment. In addition, our data imply that any Ca2+-dependent regulatory mechanism that does not involve myosin phosphorylation/dephosphorylation, if present, requires Mg2+ for expression. PMID:3140671

  9. Phosphate and ADP differently inhibit coordinated smooth muscle myosin groups.

    PubMed

    Hilbert, Lennart; Balassy, Zsombor; Zitouni, Nedjma B; Mackey, Michael C; Lauzon, Anne-Marie

    2015-02-01

    Actin filaments propelled in vitro by groups of skeletal muscle myosin motors exhibit distinct phases of active sliding or arrest, whose occurrence depends on actin length (L) within a range of up to 1.0 μm. Smooth muscle myosin filaments are exponentially distributed with ≈150 nm average length in vivo--suggesting relevance of the L-dependence of myosin group kinetics. Here, we found L-dependent actin arrest and sliding in in vitro motility assays of smooth muscle myosin. We perturbed individual myosin kinetics with varying, physiological concentrations of phosphate (Pi, release associated with main power stroke) and adenosine diphosphate (ADP, release associated with minor mechanical step). Adenosine triphosphate was kept constant at physiological concentration. Increasing [Pi] lowered the fraction of time for which actin was actively sliding, reflected in reduced average sliding velocity (ν) and motile fraction (fmot, fraction of time that filaments are moving); increasing [ADP] increased the fraction of time actively sliding and reduced the velocity while sliding, reflected in reduced ν and increased fmot. We introduced specific Pi and ADP effects on individual myosin kinetics into our recently developed mathematical model of actin propulsion by myosin groups. Simulations matched our experimental observations and described the inhibition of myosin group kinetics. At low [Pi] and [ADP], actin arrest and sliding were reflected by two distinct chemical states of the myosin group. Upon [Pi] increase, the probability of the active state decreased; upon [ADP] increase, the probability of the active state increased, but the active state became increasingly similar to the arrested state. PMID:25650929

  10. Regulation of vascular tone and arterial blood pressure: role of chloride transport in vascular smooth muscle.

    PubMed

    Hübner, Christian A; Schroeder, Björn C; Ehmke, Heimo

    2015-03-01

    Recent studies suggest that primary changes in vascular resistance can cause sustained changes in arterial blood pressure. In this review, we summarize current knowledge about Cl(-) homeostasis in vascular smooth muscle cells. Within vascular smooth muscle cells, Cl(-) is accumulated above the electrochemical equilibrium, causing Cl(-) efflux, membrane depolarization, and increased contractile force when Cl(-) channels are opened. At least two different transport mechanisms contribute to raise [Cl(-)] i in vascular smooth muscle cells, anion exchange, and cation-chloride cotransport. Recent work suggests that TMEM16A-associated Ca(2+)-activated Cl(-) currents mediate Cl(-) efflux in vascular smooth muscle cells leading to vasoconstriction. Additional proteins associated with Cl(-) flux in vascular smooth muscle are bestrophins, which modulate vasomotion, the volume-activated LRRC8, and the cystic fibrosis transmembrane conductance regulator (CFTR). Cl(-) transporters and Cl(-) channels in vascular smooth muscle cells (VSMCs) significantly contribute to the physiological regulation of vascular tone and arterial blood pressure. PMID:25588975

  11. Effect of inflammatory mediators on airway nerves and muscle

    SciTech Connect

    Daniel, E.E.; O'Byrne, P. )

    1991-03-01

    The neuromuscular mechanisms underlying airway hyperresponsiveness have been reviewed on the basis of studies of the changes induced by ozone inhalation in dogs. In vivo, there is increased, nonspecific airway hyperresponsiveness based on studies of the response to inhaled acetylcholine or histamine. The underlying inflammatory mechanism involves release of LTB4 and/or other chemotactic agents from epithelial or lumenal cells, ingress of macrophages, neutrophils, and platelets from the blood vessels between the muscle and epithelium, and migration of mast cells into the epithelium. The hyperresponsiveness seems to depend upon the influx of neutrophils and actions of thromboxane A2 released from the neutrophils. In vitro, there is increased responsiveness to field stimulation of cholinergic nerves and to acetylcholine (not to KCI) in tracheal strips. These effects can be mimicked by a thromboxane A2 analog (U44619). In the sucrose gap, the TxA2 analog does not affect the excitatory junction potential, but in low concentration it increases and prolongs a series of fading membrane oscillations closely related to the contractions. We consider these oscillations to reflect ongoing release and/or action of acetylcholine. In high concentrations the analog causes a small depolarization and a tonic contraction, but it does not enhance the sensitivity to acetylcholine. TxA2 may be acting either presynaptically or postsynaptically or both to produce these effects; however, changes in release of an epithelial-derived relaxing factor do not seem to be involved. We conclude that TxA2 actions probably underlie hyperresponsiveness developed in vivo and in vitro after ozone inhalation.

  12. Rho-kinase mediated cytoskeletal stiffness in skinned smooth muscle

    PubMed Central

    Lan, Bo; Wang, Lu; Zhang, Jenny; Pascoe, Chris D.; Norris, Brandon A.; Liu, Jeffrey C.-Y.; Solomon, Dennis; Paré, Peter D.; Deng, Linhong

    2013-01-01

    The structurally dynamic cytoskeleton is important in many cell functions. Large gaps still exist in our knowledge regarding what regulates cytoskeletal dynamics and what underlies the structural plasticity. Because Rho-kinase is an upstream regulator of signaling events leading to phosphorylation of many cytoskeletal proteins in many cell types, we have chosen this kinase as the focus of the present study. In detergent skinned tracheal smooth muscle preparations, we quantified the proteins eluted from the muscle cells over time and monitored the muscle's ability to respond to acetylcholine (ACh) stimulation to produce force and stiffness. In a partially skinned preparation not able to generate active force but could still stiffen upon ACh stimulation, we found that the ACh-induced stiffness was independent of calcium and myosin light chain phosphorylation. This indicates that the myosin light chain-dependent actively cycling crossbridges are not likely the source of the stiffness. The results also indicate that Rho-kinase is central to the ACh-induced stiffness, because inhibition of the kinase by H1152 (1 μM) abolished the stiffening. Furthermore, the rate of relaxation of calcium-induced stiffness in the skinned preparation was faster than that of ACh-induced stiffness, with or without calcium, suggesting that different signaling pathways lead to different means of maintenance of stiffness in the skinned preparation. PMID:24072407

  13. Smooth Muscle-Alpha Actin Inhibits Vascular Smooth Muscle Cell Proliferation and Migration by Inhibiting Rac1 Activity

    PubMed Central

    Chen, Lihua; DeWispelaere, Allison; Dastvan, Frank; Osborne, William R. A.; Blechner, Christine; Windhorst, Sabine; Daum, Guenter

    2016-01-01

    Smooth muscle alpha-actin (SMA) is a marker for the contractile, non-proliferative phenotype of adult smooth muscle cells (SMCs). Upon arterial injury, expression of SMA and other structural proteins decreases and SMCs acquire a pro-migratory and proliferative phenotype. To what extent SMA regulates migration and proliferation of SMCs is unclear and putative signaling pathways involved remain to be elucidated. Here, we used lentiviral-mediated gene transfer and siRNA technology to manipulate expression of SMA in carotid mouse SMCs and studied effects of SMA. Overexpression of SMA results in decreased proliferation and migration and blunts serum-induced activation of the small GTPase Rac, but not RhoA. All inhibitory effects of SMA are rescued by expression of a constitutively active Rac1 mutant (V12rac1). Moreover, reduction of SMA expression by siRNA technology results in an increased activation of Rac. Taken together, this study identifies Rac1 as a downstream target for SMA to inhibit SMC proliferation and migration. PMID:27176050

  14. In vitro proliferation of aortic smooth muscle cells from spontaneously hypertensive and normotensive rats.

    PubMed

    Pang, S C

    1989-06-01

    The characteristics and proliferation of aortic smooth muscle cells (SMC) from spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were studied in culture. Smooth muscle cells were isolated from the tunica media of the thoracic aorta by an explant method. Immunofluorescence microscopy showed that 93-95 per cent of cells were positively labelled with antibodies raised against smooth muscle actin, indicating that these were smooth muscle cells. The proliferative activity was compared between aortic smooth muscle cells from hypertensive and normotensive rats in culture by thymidine incorporation and cell number determinations. The results demonstrate that aortic smooth muscle cells from hypertensive rats grew faster than those from normotensive rats in culture. The increased proliferative activity of cultured aortic smooth muscle cells from hypertensive rats was detectable even when they were cultured in a chemically defined serum-free medium. These data have shown that an increased proliferative activity of aortic smooth muscle cells from hypertensive rats can occur in culture conditions without the influence of arterial pressure or other stimuli as in intact animals. The mechanisms underlying the accelerated proliferative activity of aortic smooth muscle cells from genetically hypertensive rats in vitro remain to be determined. PMID:2754547

  15. Potassium and insulin affect the contractility of abomasal smooth muscle.

    PubMed

    Türck, G; Leonhard-Marek, S

    2010-08-01

    Abomasal displacement is a frequent and important disease of high yielding dairy cows. Although several factors are related to its occurrence, the pathogenesis of the condition is still inadequately understood, particularly in regard to K(+) and insulin homeostasis. For this reason the aim was to investigate the effects of K(+) and insulin concentrations on in vitro motility of abomasal smooth muscle. The second aim was to determine whether the in vivo change in K(+) and insulin levels might be sufficient to induce reduced abomasal motility. Muscle strips were isolated from the abomasum of slaughtered cows and incubated in buffer solution under isometric conditions. Results show that a decrease in extracellular K(+) (between 5 and 1 mmol/L) or an increase in extracellular insulin concentrations (to 21 mU/L or higher) were able to affect the contraction activity of abomasal muscles. Contraction activity given as median (25th, 75th percentiles) changed from 28.1 mN/min (2.5, 49.9) at 5 mmol/L of K(+) to 9.4 mN/min (0.6, 35.7) at 1 mmol/L of K(+), and from 34.5 mN/min (10.8, 112.4) at 0 mU/L of insulin to 12.0 mN/min (7.6, 49.8) at 120 mU/L of insulin. Because the effect of insulin could be abolished by barium, glybenclamide, or ouabain, the underlying mechanisms of the insulin action could be an increased K(+) conductance or an increased Na/K-ATPase activity or both. Low K(+) or high insulin concentrations both reduced the activity of the circular muscle of the abomasal corpus (i.e., of the part that is responsible for the propulsion of abomasal chymus) and might play an important role in the pathogenesis of abomasal displacement. PMID:20655424

  16. Simulated Hypergravity Alters Vascular Smooth Muscle Cell Proliferation and Motility

    NASA Technical Reports Server (NTRS)

    Hunt, Shameka; Bettis, Barika; Harris-Hooker, Sandra; Sanford, Gary L.

    1997-01-01

    The cellular effects of gravity are poorly understood due to its constancy and nonavailability of altered gravitational models. Such an understanding is crucial for prolonged space flights. In these studies, we assessed the influence of centrifugation at 6G (HGrav) on vascular smooth muscle (SMC) mobility and proliferation. Cells were: (a) plated at low density and subjected to HGrav for 24-72 hr for proliferation studies, or (b) grown to confluency, subjected to HGrav, mechanically denuded and monitored for cell movement into the denuded area. Controls were maintained under normogravity. SMC showed a 50% inhibition of growth under HGrav and 10% serum; HGrav and low serum resulted in greater growth inhibition. The rate of movement of SMC into the denuded area was 2-3-fold higher under HGrav in low serum compared to controls, but similar in 10% serum. These studies show that HGrav has significant effects on SMC growth and mobility, which are dependent on serum levels.

  17. Smooth muscle relaxing flavonoids and terpenoids from Conyza filaginoides.

    PubMed

    Mata, R; Rojas, A; Acevedo, L; Estrada, S; Calzada, F; Rojas, I; Bye, R; Linares, E

    1997-02-01

    Activity-guided fractionation of the smooth muscle relaxing, chloroform-methanol (1:1) extract of Conyza filaginoides (D.C.) Hieron (Asteraceae) led to the isolation of three flavonoids (quercetin 3-glucoside, rutin, and pinostrobin), one sterol (alpha-spinasterol), a sesquiterpenoid (beta-caryophyllene 4,5-alpha-oxide), and two triterpenoids (erythrodiol and 3-beta-tridecanoyloxy-28-hydroxyolean-12-ene). 3-beta-Tridecanoyloxy-28-hydroxy-olean-12-ene is a new naturally occurring terpenoid. All the isolated compounds induced a concentration-dependent inhibition of the spontaneous contractions of rat ileum. The spasmolytic activity exhibited by the extract and active principles tends to support the traditional use of C filaginoides as an antispasmodic agent. PMID:9063094

  18. Oxygen mediates vascular smooth muscle relaxation in hypoxia.

    PubMed

    Dada, Jessica; Pinder, Andrew G; Lang, Derek; James, Philip E

    2013-01-01

    The activation of soluble guanylate cyclase (sGC) by nitric oxide (NO) and other ligands has been extensively investigated for many years. In the present study we considered the effect of molecular oxygen (O2) on sGC both as a direct ligand and its affect on other ligands by measuring cyclic guanosine monophosphate (cGMP) production, as an index of activity, as well as investigating smooth muscle relaxation under hypoxic conditions. Our isolated enzyme studies confirm the function of sGC is impaired under hypoxic conditions and produces cGMP in the presence of O2, importantly in the absence of NO. We also show that while O2 could partially affect the magnitude of sGC stimulation by NO when the latter was present in excess, activation by the NO independent, haem-dependent sGC stimulator 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) was unaffected. Our in vitro investigation of smooth muscle relaxation confirmed that O2 alone in the form of a buffer bolus (equilibrated at 95% O2/5% CO2) had the ability to dilate vessels under hypoxic conditions and that this was dependent upon sGC and independent of eNOS. Our studies confirm that O2 can be a direct and important mediator of vasodilation through an increase in cGMP production. In the wider context, these observations are key to understanding the relative roles of O2 versus NO-induced sGC activation. PMID:23451175

  19. Oxygen Mediates Vascular Smooth Muscle Relaxation in Hypoxia

    PubMed Central

    Lang, Derek; James, Philip E.

    2013-01-01

    The activation of soluble guanylate cyclase (sGC) by nitric oxide (NO) and other ligands has been extensively investigated for many years. In the present study we considered the effect of molecular oxygen (O2) on sGC both as a direct ligand and its affect on other ligands by measuring cyclic guanosine monophosphate (cGMP) production, as an index of activity, as well as investigating smooth muscle relaxation under hypoxic conditions. Our isolated enzyme studies confirm the function of sGC is impaired under hypoxic conditions and produces cGMP in the presence of O2, importantly in the absence of NO. We also show that while O2 could partially affect the magnitude of sGC stimulation by NO when the latter was present in excess, activation by the NO independent, haem-dependent sGC stimulator 3-(5′-hydroxymethyl-2′-furyl)-1-benzylindazole (YC-1) was unaffected. Our in vitro investigation of smooth muscle relaxation confirmed that O2 alone in the form of a buffer bolus (equilibrated at 95% O2/5% CO2) had the ability to dilate vessels under hypoxic conditions and that this was dependent upon sGC and independent of eNOS. Our studies confirm that O2 can be a direct and important mediator of vasodilation through an increase in cGMP production. In the wider context, these observations are key to understanding the relative roles of O2 versus NO-induced sGC activation. PMID:23451175

  20. Engineering smooth muscle tissue with a predefined structure.

    PubMed

    Kim, B S; Mooney, D J

    1998-08-01

    Nonwoven meshes of polyglycolic acid (PGA) fibers are attractive synthetic extracellular matrices (ECMs) for tissue engineering and have been used to engineer many types of tissues. However, these synthetic ECMs lack structural stability and often cannot maintain their original structure during tissue development. This makes it difficult to design an engineered tissue with a predefined configuration and dimensions. In this study, we investigated the ability of PGA fiber-based matrices bonded at their fiber crosspoints with a secondary polymer, poly-L-lactic acid (PLLA), to resist cellular contractile forces and maintain their predefined structure during the process of smooth muscle (SM) tissue development in vitro. Physically bonded PGA matrices exhibited a 10- to 35-fold increase in the compressive modulus over unbonded PGA matrices, depending on the mass of PLLA utilized to bond the PGA matrices. In addition, the bonded PGA matrices degraded much more slowly than the unbonded matrices. The PLLA bonding of PGA matrices had no effect on the ability of cells to adhere to the matrices. After 7 weeks in culture, the bonded matrices maintained 101 +/- 4% of their initial volume and an approximate original shape while the unbonded matrices contracted to 5 +/- 1% of their initial volume with an extreme change in their shape. At this time the bonded PGA matrices had a high cellularity, with smooth muscle cells (SMCs) and ECM proteins produced by these cells (e.g., elastin) filling the pores between PGA fibers. This study demonstrated that physically bonded PGA fiber-based matrices allow the maintenance of the configuration and dimensions of the original matrices and the development of a new tissue in a predefined three-dimensional structure. This approach may be useful for engineering a variety of tissues of various structures and shapes, and our study demonstrates the importance of matching both the initial mechanical properties and the degradation rate of a matrix to

  1. Role of smooth muscle cell mineralocorticoid receptor in vascular tone.

    PubMed

    Tarjus, Antoine; Belozertseva, Ekaterina; Louis, Huguette; El Moghrabi, Soumaya; Labat, Carlos; Lacolley, Patrick; Jaisser, Frédéric; Galmiche, Guillaume

    2015-08-01

    Identification of the mineralocorticoid receptor (MR) in the vasculature (i.e., endothelial and smooth muscle cells) raised the question of its role in vascular function and blood pressure control. Using a mouse model with conditional inactivation of MR in vascular smooth muscle cell (VSMC) (MR(SMKO)), we have recently shown that the VSMC MR is crucial for aldosterone-salt-induced carotid stiffening. In the present study, we have investigated the specific contribution of the VSMC MR in the regulation of vascular tone in large vessels. In MR(SMKO) mice, contractions induced by potassium chloride and calcium (Ca(2+)) are decreased in the aorta, whereas contraction is normal in response to phenylephrine and caffeine. The difference in response to Ca(2+) suggests that the VSMC-specific deficiency of the MR modifies VSM Ca(2+) signaling but without altering the intracellular Ca(2+) store handling. The relaxation induced by acetylcholine is not affected by the absence of MR. However, the relaxation induced by Ach in the presence of indomethacin and the relaxation induced by sodium nitroprussiate are significantly reduced in MR(SMKO) mice compared to controls. Since endothelial nitric oxide synthase (eNOS) activity is increased in mutant mice, their altered relaxation reflects impairment of the nitric oxide (NO) signaling pathway. In addition to altered NO and Ca(2+) signaling, the activity of myosin light chain and its regulators, myosin light chain kinase (MLCK) and myosin phosphatase (MLCP), is reduced. In conclusion, MR expressed in VSMC is required for NO and Ca(2+) signaling pathways and contractile protein activity leading to an altered contraction/relaxation coupling. PMID:25262754

  2. Circular smooth muscle contributes to esophageal shortening during peristalsis

    PubMed Central

    Vegesna, Anil K; Chuang, Keng-Yu; Besetty, Ramashesai; Phillips, Steven J; Braverman, Alan S; Barbe, Mary F; Ruggieri, Michael R; Miller, Larry S

    2012-01-01

    AIM: To study the angle between the circular smooth muscle (CSM) and longitudinal smooth muscle (LSM) fibers in the distal esophagus. METHODS: In order to identify possible mechanisms for greater shortening in the distal compared to proximal esophagus during peristalsis, the angles between the LSM and CSM layers were measured in 9 cadavers. The outer longitudinal layer of the muscularis propria was exposed after stripping the outer serosa. The inner circular layer of the muscularis propria was then revealed after dissection of the esophageal mucosa and the underlying muscularis mucosa. Photographs of each specimen were taken with half of the open esophagus folded back showing both the outer longitudinal and inner circular muscle layers. Angles were measured every one cm for 10 cm proximal to the squamocolumnar junction (SCJ) by two independent investigators. Two human esophagi were obtained from organ transplant donors and the angles between the circular and longitudinal smooth muscle layers were measured using micro-computed tomography (micro CT) and Image J software. RESULTS: All data are presented as mean ± SE. The CSM to LSM angle at the SCJ and 1 cm proximal to SCJ on the autopsy specimens was 69.3 ± 4.62 degrees vs 74.9 ± 3.09 degrees, P = 0.32. The CSM to LSM angle at SCJ were statistically significantly lower than at 2, 3, 4 and 5 cm proximal to the SCJ, 69.3 ± 4.62 degrees vs 82.58 ± 1.34 degrees, 84.04 ± 1.64 degrees, 84.87 ± 1.04 degrees and 83.72 ± 1.42 degrees, P = 0.013, P = 0.008, P = 0.004, P = 0.009 respectively. The CSM to LSM angle at SCJ was also statistically significantly lower than the angles at 6, 7 and 8 cm proximal to the SCJ, 69.3 ± 4.62 degrees vs 80.18 ± 2.09 degrees, 81.81 ± 1.75 degrees and 80.96 ± 2.04 degrees, P = 0.05, P = 0.02, P = 0.03 respectively. The CSM to LSM angle at 1 cm proximal to SCJ was statistically significantly lower than at 3, 4 and 5 cm proximal to the SCJ, 74.94 ± 3.09 degrees vs 84.04 ± 1

  3. Tonic activity in inspiratory muscles during continuous negative airway pressure.

    PubMed

    Meessen, N E; van der Grinten, C P; Folgering, H T; Luijendijk, S C

    1993-05-01

    We studied tonic inspiratory activity (TIA) induced by continuous negative airway pressure (CNAP) in anaesthetized, spontaneously breathing cats. TIA in the diaphragm and parasternal intercostal muscles (ICM) was quantified in response to tracheal pressure (PTR) = -0.3 to -1.2 kPa. To differentiate between reflexes from rapidly adapting receptors (RARs), slowly adapting receptors (SARs) and C-fiber endings different temperatures of the vagus nerves (TVG) were used between 4 and 37 degrees C. At PTR = -1.2 kPa mean TIA values were 41% and 62% of peak inspiratory EMG activity of control breaths for the diaphragm and ICM, respectively. After vagotomy and for TVG < 6 degrees C CNAP did not induce TIA anymore. Changes in inspiratory and expiratory time during vagal cooling down to 4 degrees C confirmed the selective block of conductance in vagal afferents of the three types of lung receptors. We conclude that CNAP-induced TIA results from stimulation of RARs. Our data strongly indicate that stimulation of SARs suppresses TIA, whereas C-fiber endings are not involved in TIA at all. The results suggest that part of the hyperinflation in bronchial asthma may be caused by TIA in response to mechanical stimulation of RARs. PMID:8327788

  4. Pullulan-based hydrogel for smooth muscle cell culture.

    PubMed

    Autissier, Aude; Letourneur, Didier; Le Visage, Catherine

    2007-08-01

    A hydrogel was prepared from pullulan and evaluated as a novel biomaterial for vascular engineering. Using a crosslinking process with sodium trimetaphosphate in aqueous solution, homogeneous, transparent, and easy-to-handle pullulan gels were obtained with water-content higher than 90%. A circular punch was used to cut 6-mm diameter and 2-mm thickness discs for cell culture. Environmental scanning electron microscopy analysis of hydrated gels revealed a smooth surface, on which rabbit vascular smooth muscle cells were successfully seeded. The absence of cytotoxicity was evidenced by a live/dead assay. Fluorescence-labeled cells were observed adhering and progressively spreading out on the surface of the material. Cellular proliferation was followed for up to 1 week using an MTT assay. In addition, a complete in vitro degradation of the gels was achieved in 3 h upon incubation in a pullulanase solution (44 U/mL). In conclusion, we have shown the feasibility of preparing a biocompatible pullulan-based hydrogel that could support vascular cell culture. Based on these promising results, future studies will focus on the seeding of vascular cells on tubular-shaped hydrogels and the in vivo implantation of these new biomaterials. PMID:17295223

  5. Impaired Bronchoprotection Is Not Induced by Increased Smooth Muscle Mass in Chronic Treatment In Vivo with Formoterol in Asthmatic Mouse Model

    PubMed Central

    Luo, W; Liu, C-T; Yang, Q-H; Yu, Q; Wang, T

    2014-01-01

    ABSTRACT Objective: Inhaling β2-adrenoceptor agonist is first-line asthma treatment, which is used for both acute relief of and prevention of bronchoconstriction. However, chronic use of β-agonists results in impaired bronchoprotection and increasing occurrences of severe asthma exacerbation, even death in clinical practice. The mechanism of β-adrenoceptor hyposensitivity has not been thoroughly elucidated thus far. Bronchial smooth muscle contraction induces airway narrowing and also mediates airway inflammation. Moreover, bronchial smooth muscle mass significantly increases in asthmatics. We aim to establish an asthmatic model that demonstrated that formoterol induced impaired bronchoprotection and to see whether increased smooth muscle mass played a role in it. Methods: We combined routine allergen challenging (seven weeks) with repeated application of formoterol, formoterol plus budesonide or physiological saline in allergen-sensitized BALB/c mouse. The bronchoprotection mediated by β-agonist was measured in five consecutive weeks. Smooth muscle mass was shown by morphometric analysis, and α-actin expression was detected by western blot. Results: The trend of bronchoprotection was wavy in drug interventional groups, which initially increased and then decreased. Chronic treatment with formoterol significantly impaired bronchoprotection. According to the morphometric analysis and α-actin expression, no significant difference was detected in smooth muscle mass in all groups. Conclusion: This experiment successfully established that a chronic asthmatic mouse model, which manifested typical features of asthmatic patients, when treated chronically with formoterol, showed a loss of bronchoprotection. No significant difference was detected in smooth muscle mass in all groups, which implied some subcellular signalling changes may be the key points. PMID:25803396

  6. Unregulated smooth-muscle myosin in human intestinal neoplasia.

    PubMed

    Alhopuro, Pia; Phichith, Denis; Tuupanen, Sari; Sammalkorpi, Heli; Nybondas, Miranda; Saharinen, Juha; Robinson, James P; Yang, Zhaohui; Chen, Li-Qiong; Orntoft, Torben; Mecklin, Jukka-Pekka; Järvinen, Heikki; Eng, Charis; Moeslein, Gabriela; Shibata, Darryl; Houlston, Richard S; Lucassen, Anneke; Tomlinson, Ian P M; Launonen, Virpi; Ristimäki, Ari; Arango, Diego; Karhu, Auli; Sweeney, H Lee; Aaltonen, Lauri A

    2008-04-01

    A recent study described a recessive ATPase activating germ-line mutation in smooth-muscle myosin (smmhc/myh11) underlying the zebrafish meltdown (mlt) phenotype. The mlt zebrafish develops intestinal abnormalities reminiscent of human Peutz-Jeghers syndrome (PJS) and juvenile polyposis (JP). To examine the role of MYH11 in human intestinal neoplasia, we searched for MYH11 mutations in patients with colorectal cancer (CRC), PJS and JP. We found somatic protein-elongating frameshift mutations in 55% of CRCs displaying microsatellite instability and in the germ-line of one individual with PJS. Additionally, two somatic missense mutations were found in one microsatellite stable CRC. These two missense mutations, R501L and K1044N, and the frameshift mutations were functionally evaluated. All mutations resulted in unregulated molecules displaying constitutive motor activity, similar to the mutant myosin underlying mlt. Thus, MYH11 mutations appear to contribute also to human intestinal neoplasia. Unregulated MYH11 may affect the cellular energy balance or disturb cell lineage decisions in tumor progenitor cells. These data challenge our view on MYH11 as a passive differentiation marker functioning in muscle contraction and add to our understanding of intestinal neoplasia. PMID:18391202

  7. The LIM protein leupaxin is enriched in smooth muscle and functions as an serum response factor cofactor to induce smooth muscle cell gene transcription.

    PubMed

    Sundberg-Smith, Liisa J; DiMichele, Laura A; Sayers, Rebecca L; Mack, Christopher P; Taylor, Joan M

    2008-06-20

    Leupaxin is a LIM domain-containing adapter protein belonging to the paxillin family that has been previously reported to be preferentially expressed in hematopoietic cells. Herein, we identified leupaxin in a screen for focal adhesion kinase binding partners in aortic smooth muscle, and we show that leupaxin is enriched in human and mouse vascular smooth muscle and that leupaxin expression is dynamically regulated during development. In addition, our studies reveal that leupaxin can undergo cytoplasmic/nuclear shuttling and functions as an serum response factor cofactor in the nucleus. We found that leupaxin forms a complex with serum response factor and associates with CArG-containing regions of smooth muscle promoters and that ectopic expression of leupaxin induces smooth muscle marker gene expression in both 10T1/2 cells and rat aortic smooth muscle cells. Subsequent studies indicated that enhanced focal adhesion kinase activity (induced by fibronectin or expression of constitutively active focal adhesion kinase) attenuates the nuclear accumulation of leupaxin and limits the ability of leupaxin to enhance serum response factor-dependent gene transcription. Thus, these studies indicate that modulation of the subcellular localization of serum response factor cofactors is 1 mechanism by which extracellular matrix-dependent signals may regulate phenotypic switching of smooth muscle cells. PMID:18497331

  8. Immune/Inflammatory Response and Hypocontractility of Rabbit Colonic Smooth Muscle After TNBS-Induced Colitis

    PubMed Central

    Zhang, Yonggang; Li, Fang; Wang, Hong; Yin, Chaoran; Huang, JieAn; Mahavadi, Sunila; Murthy, Karnam S.

    2016-01-01

    Background The contractility of colonic smooth muscle is dysregulated due to immune/inflammatory responses in inflammatory bowel diseases. Inflammation in vitro induces up-regulation of regulator of G-protein signaling 4 (RGS4) expression in colonic smooth muscle cells. Aims To characterize the immune/inflammatory responses and RGS4 expression pattern in colonic smooth muscle after induction of colitis. Methods Colitis was induced in rabbits by intrarectal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Innate/adaptive immune response RT-qPCR array was performed using colonic circular muscle strips. At 1–9 weeks after colonic intramuscular microinjection of lentivirus, the distal and proximal colons were collected, and muscle strips and dispersed muscle cells were prepared from circular muscle layer. Expression levels of RGS4 and NFκB signaling components were determined by Western blot analysis. The biological consequences of RGS4 knockdown were assessed by measurement of muscle contraction and phospholipase C (PLC)-β activity in response to acetylcholine (ACh). Results Contraction in response to ACh was significantly inhibited in the inflamed colonic circular smooth muscle cells. RGS4, IL-1, IL-6, IL-8, CCL3, CD1D, and ITGB2 were significantly up-regulated, while IL-18, CXCR4, CD86, and C3 were significantly down-regulated in the inflamed muscle strips. RGS4 protein expression in the inflamed smooth muscles was dramatically increased. RGS4 stable knockdown in vivo augmented ACh-stimulated PLC-β activity and contraction in colonic smooth muscle cells. Conclusion Inflamed smooth muscle exhibits up-regulation of IL-1-related signaling components, Th1 cytokines and RGS4, and inhibition of contraction. Stable knockdown of endogenous RGS4 in colonic smooth muscle increases PLC-β activity and contractile responses. PMID:26879904

  9. Functional identification of a sarcolemmal chloride channel from bovine tracheal smooth muscle.

    PubMed

    Salvail, D; Alioua, A; Rousseau, E

    1996-11-01

    The biophysical and pharmacological characteristics of unitary Cl- currents from bovine tracheal smooth muscle cells were studied after reconstitution of microsomal vesicles into planar lipid bilayers. Two types of currents were recorded simultaneously in KCl buffer: the well-defined Ca(2+)-dependent K+ conductance [GK(Ca)] and a much smaller Cl- current, indicating that the Cl- channels under scrutiny originate from the same membrane as the GK(Ca)-type channels, the plasma membrane of airway smooth muscle (ASM) cells. The GK(Ca) activities were eliminated by the use of CsCl buffer. The average unitary Cl- conductance measured in 50 mM trans-250 mM cis CsCl was 77 +/- 6 pS (n = 21), and the reversal potential measured in various CsCl gradients followed the Cl- equilibrium potential as determined from the Nernst equation. In contrast with the previous reports describing the Ca2+ sensitivity of macroscopic ASM Cl- currents, this channel was found to be insensitive to cytoplasmic and extracellular Ca2+ levels. Phosphorylation cocktails, including protein kinases A, G, or C, did not alter the activity of the channel nor did changes in pH. Among a series of Cl- channel inhibitors, 4,4'-diisothiocyanostilbene-2, 2'-disulfonic acid [50% effective concentration (EC50) = 30 microM] and 5-nitro-2-(3-phenylpropylamino) benzoic acid (EC50 = 130 microM) were the most potent blockers of the current examined. The exact role of this surface Cl- conductance remains unclear, and its involvement in cellular activity needs further investigation. PMID:8944656

  10. miR-145 and miR-143 Regulate Smooth Muscle Cell Fate Decisions

    PubMed Central

    Cordes, Kimberly R.; Sheehy, Neil T.; White, Mark; Berry, Emily; Morton, Sarah U.; Muth, Alecia N.; Lee, Ting-Hein; Miano, Joseph M.; Ivey, Kathryn N.; Srivastava, Deepak

    2009-01-01

    SUMMARY microRNAs are regulators of myriad cellular events, but evidence for a single microRNA that can efficiently differentiate multipotent cells into a specific lineage or regulate direct reprogramming of cells into an alternate cell fate has been elusive. Here, we show that miR-145 and miR-143 are co-transcribed in multipotent cardiac progenitors before becoming localized to smooth muscle cells, including neural crest stem cell–derived vascular smooth muscle cells. miR-145 and miR-143 were direct transcriptional targets of serum response factor, myocardin and Nkx2.5, and were downregulated in injured or atherosclerotic vessels containing proliferating, less differentiated smooth muscle cells. miR-145 was necessary for myocardin-induced reprogramming of adult fibroblasts into smooth muscle cells and sufficient to induce differentiation of multipotent neural crest stem cells into vascular smooth muscle. Furthermore, miR-145 and miR-143 cooperatively targeted a network of transcription factors, including Klf4, myocardin, and Elk-1 to promote differentiation and repress proliferation of smooth muscle cells. These findings demonstrate that miR-145 can direct the smooth muscle fate and that miR-145 and miR-143 function to regulate the quiescent versus proliferative phenotype of smooth muscle cells. PMID:19578358

  11. Calcium ion-regulated thin filaments from vascular smooth muscle.

    PubMed Central

    Marston, S B; Trevett, R M; Walters, M

    1980-01-01

    Myosin and actin competition tests indicated the presence of both thin-filament and myosin-linked Ca2+-regulatory systems in pig aorta and turkey gizzard smooth-muscle actomyosin. A thin-filament preparation was obtained from pig aortas. The thin filaments had no significant ATPase activity [1.1 +/- 2.6 nmol/mg per min (mean +/- S.D.)], but they activated skeletal-muscle myosin ATPase up to 25-fold [500 nmol/mg of myosin per min (mean +/- S.D.)] in the presence of 10(-4) M free Ca2+. At 10(-8) M-Ca2+ the thin filaments activated myosin ATPase activity only one-third as much. Thin-filament activation of myosin ATPase activity increased markedly in the range 10(-6)-10(-5) M-Ca2+ and was half maximal at 2.7 x 10(-6) M (pCa2+ 5.6). The skeletal myosin-aorta-thin-filament mixture gave a biphasic ATPase-rate-versus-ATP-concentration curve at 10(-8) M-Ca2+ similar to the curve obtained with skeletal-muscle thin filaments. Thin filaments bound up to 9.5 mumol of Ca2+/g in the presence of MgATP2-. In the range 0.06-27 microM-Ca2+ binding was hyperbolic with an estimated binding constant of (0.56 +/- 0.07) x 10(6) M-1 (mean +/- S.D.) and maximum binding of 8.0 +/- 0.8 mumol/g (mean +/- S.D.). Significantly less Ca2+ bound in the absence of ATP. The thin filaments contained actin, tropomyosin and several other unidentified proteins. 6 M-Urea/polyacrylamide-gel electrophoresis at pH 8.3 showed proteins that behaved like troponin I and troponin C. This was confirmed by forming interspecific complexes between radioactive skeletal-muscle troponin I and troponin C and the aorta thin-filament proteins. The thin filaments contained at least 1.4 mumol of a troponin C-like protein/g and at least 1.1 mumol of a troponin I-like protein/g. PMID:6446898

  12. Lingual Muscle Activity Across Sleep–Wake States in Rats with Surgically Altered Upper Airway

    PubMed Central

    Rukhadze, Irma; Kalter, Julie; Stettner, Georg M.; Kubin, Leszek

    2014-01-01

    Obstructive sleep apnea (OSA) patients have increased upper airway muscle activity, including such lingual muscles as the genioglossus (GG), geniohyoid (GH), and hyoglossus (HG). This adaptation partially protects their upper airway against obstructions. Rodents are used to study the central neural control of sleep and breathing but they do not naturally exhibit OSA. We investigated whether, in chronically instrumented, behaving rats, disconnecting the GH and HG muscles from the hyoid (H) apparatus would result in a compensatory increase of other upper airway muscle activity (electromyogram, EMG) and/or other signs of upper airway instability. We first determined that, in intact rats, lingual (GG and intrinsic) muscles maintained stable activity levels when quantified based on 2 h-long recordings conducted on days 6 through 22 after instrumentation. We then studied five rats in which the tendons connecting the GH and HG muscles to the H apparatus were experimentally severed. When quantified across all recording days, lingual EMG during slow-wave sleep (SWS) was modestly but significantly increased in rats with surgically altered upper airway [8.6 ± 0.7% (SE) vs. 6.1 ± 0.7% of the mean during wakefulness; p = 0.012]. Respiratory modulation of lingual EMG occurred mainly during SWS and was similarly infrequent in both groups, and the incidence of sighs and central apneas also was similar. Thus, a weakened action of selected lingual muscles did not produce sleep-disordered breathing but resulted in a relatively elevated activity in other lingual muscles during SWS. These results encourage more extensive surgical manipulations with the aim to obtain a rodent model with collapsible upper airway. PMID:24803913

  13. The comparative effects of aminoglycoside antibiotics and muscle relaxants on electrical field stimulation response in rat bladder smooth muscle.

    PubMed

    Min, Chang Ho; Min, Young Sil; Lee, Sang Joon; Sohn, Uy Dong

    2016-06-01

    It has been reported that several aminoglycoside antibiotics have a potential of prolonging the action of non-depolarizing muscle relaxants by drug interactions acting pre-synaptically to inhibit acetylcholine release, but antibiotics itself also have a strong effect on relaxing the smooth muscle. In this study, four antibiotics of aminoglycosides such as gentamicin, streptomycin, kanamycin and neomycin were compared with skeletal muscle relaxants baclofen, tubocurarine, pancuronium and succinylcholine, and a smooth muscle relaxant, papaverine. The muscle strips isolated from the rat bladder were stimulated with pulse trains of 40 V in amplitude and 10 s in duration, with pulse duration of 1 ms at the frequency of 1-8 Hz, at 1, 2, 4, 6, 8 Hz respectively. To test the effect of four antibiotics on bladder smooth muscle relaxation, each of them was treated cumulatively from 1 μM to 0.1 mM with an interval of 5 min. Among the four antibiotics, gentamicin and neomycin inhibited the EFS response. The skeletal muscle relaxants (baclofen, tubocurarine, pancuronium and succinylcholine) and inhibitory neurotransmitters (GABA and glycine) did not show any significant effect. However, papaverine, had a significant effect in the relaxation of the smooth muscle. It was suggested that the aminoglycoside antibiotics have inhibitory effect on the bladder smooth muscle. PMID:27260628

  14. Cardiac, skeletal, and smooth muscle mitochondrial respiration: are all mitochondria created equal?

    PubMed Central

    Park, Song-Young; Gifford, Jayson R.; Andtbacka, Robert H. I.; Trinity, Joel D.; Hyngstrom, John R.; Garten, Ryan S.; Diakos, Nikolaos A.; Ives, Stephen J.; Dela, Flemming; Larsen, Steen; Drakos, Stavros

    2014-01-01

    Unlike cardiac and skeletal muscle, little is known about vascular smooth muscle mitochondrial respiration. Therefore, the present study examined mitochondrial respiratory rates in smooth muscle of healthy human feed arteries and compared with that of healthy cardiac and skeletal muscles. Cardiac, skeletal, and smooth muscles were harvested from a total of 22 subjects (53 ± 6 yr), and mitochondrial respiration was assessed in permeabilized fibers. Complex I + II, state 3 respiration, an index of oxidative phosphorylation capacity, fell progressively from cardiac to skeletal to smooth muscles (54 ± 1, 39 ± 4, and 15 ± 1 pmol·s−1·mg−1, P < 0.05, respectively). Citrate synthase (CS) activity, an index of mitochondrial density, also fell progressively from cardiac to skeletal to smooth muscles (222 ± 13, 115 ± 2, and 48 ± 2 μmol·g−1·min−1, P < 0.05, respectively). Thus, when respiration rates were normalized by CS (respiration per mitochondrial content), oxidative phosphorylation capacity was no longer different between the three muscle types. Interestingly, complex I state 2 normalized for CS activity, an index of nonphosphorylating respiration per mitochondrial content, increased progressively from cardiac to skeletal to smooth muscles, such that the respiratory control ratio, state 3/state 2 respiration, fell progressively from cardiac to skeletal to smooth muscles (5.3 ± 0.7, 3.2 ± 0.4, and 1.6 ± 0.3 pmol·s−1·mg−1, P < 0.05, respectively). Thus, although oxidative phosphorylation capacity per mitochondrial content in cardiac, skeletal, and smooth muscles suggest all mitochondria are created equal, the contrasting respiratory control ratio and nonphosphorylating respiration highlight the existence of intrinsic functional differences between these muscle mitochondria. This likely influences the efficiency of oxidative phosphorylation and could potentially alter ROS production. PMID:24906913

  15. PDMS Elastic Micropost Arrays for Studying Vascular Smooth Muscle Cells

    PubMed Central

    Cheng, Qi; Sun, Zhe; Meininger, Gerald; Almasri, Mahmoud

    2015-01-01

    This paper describes the design, modeling, fabrication and characterization of a micromachined array of high-density 3-dimensional microposts (100×100) made of flexible material (silicone elastomers) for use to measure quantitatively the cellular traction force and contractile events in isolated vascular smooth muscle cells (VSMCs). The micropost array was fabricated with diameters ranged from 3 to 10 μm, with edge to edge spacing of 5, 7 and 10 μm, and with a height to diameter aspect ratio up to 10. VSMCs exerted larger basal traction forces when they were grown on stiffer micropost arrays. These basal traction forces were 80% larger in control VSMCs than in VSMCs in which integrin linked kinase (ILK) was knocked down using shRNA. The addition of Angiotensin II (ANGII) led to VSMC contraction as evidenced by an increased traction force exerted on the microposts under the cell. This ANGII induced contractile response and change in traction force on the microposts was not observed in VSMCs lacking ILK. Following treatment of VSMCs with Cytochalasin D to depolymerize the actin cytoskeleton, the VSMCs exhibited relaxation that was apparent as a significant reduction in the measured traction force exerted on microposts under the cell. Overall, this study demonstrates the usefulness of micropost arrays for study of the contractile responsiveness of VSMC and the results indicate that ILK plays a critical role in the signaling pathways leading to the generation of substrate traction force in VSMC. PMID:26451074

  16. Tensile Properties of Contractile and Synthetic Vascular Smooth Muscle Cells

    NASA Astrophysics Data System (ADS)

    Miyazaki, Hiroshi; Hasegawa, Yoshitaka; Hayashi, Kozaburo

    Tensile properties of vascular smooth muscle cells (VSMCs) of synthetic and contractile phenotypes were determined using a newly developed tensile test system. Synthetic and contractile VSMCs were isolated from the rabbit thoracic aorta with an explant and an enzymatic digestion method, respectively. Each cell floated in Hanks' balanced salt solution of 37°C was attached to the fine tips of a pair of micropipettes with a cell adhesive and, then, stretched at the rate of 6µm/sec by moving one of the micropipettes with a linear actuator. Load applied to the cell was measured with a cantilever-type load cell; its elongation was determined from the distance between the micropipette tips using a video dimension analyzer. The synthetic and contractile VSMCs were not broken even at the tensile force of 2.4µN and 3.4µN, respectively. Their stiffness was significantly higher in contractile phenotype (0.17N/m) than in synthetic one (0.09N/m). The different tensile properties between synthetic and contractile cells are attributable to the differences in cytoskeletal structures and contractile apparatus.

  17. Origin and differentiation of vascular smooth muscle cells

    PubMed Central

    Wang, Gang; Jacquet, Laureen; Karamariti, Eirini; Xu, Qingbo

    2015-01-01

    Vascular smooth muscle cells (SMCs), a major structural component of the vessel wall, not only play a key role in maintaining vascular structure but also perform various functions. During embryogenesis, SMC recruitment from their progenitors is an important step in the formation of the embryonic vascular system. SMCs in the arterial wall are mostly quiescent but can display a contractile phenotype in adults. Under pathophysiological conditions, i.e. vascular remodelling after endothelial dysfunction or damage, contractile SMCs found in the media switch to a secretory type, which will facilitate their ability to migrate to the intima and proliferate to contribute to neointimal lesions. However, recent evidence suggests that the mobilization and recruitment of abundant stem/progenitor cells present in the vessel wall are largely responsible for SMC accumulation in the intima during vascular remodelling such as neointimal hyperplasia and arteriosclerosis. Therefore, understanding the regulatory mechanisms that control SMC differentiation from vascular progenitors is essential for exploring therapeutic targets for potential clinical applications. In this article, we review the origin and differentiation of SMCs from stem/progenitor cells during cardiovascular development and in the adult, highlighting the environmental cues and signalling pathways that control phenotypic modulation within the vasculature. PMID:25952975

  18. Molecular mechanisms of increased vascular smooth muscle contraction in SHR

    SciTech Connect

    Sharma, R.V.; Aqel, M.B.; Butters, C.; McEldoon, J.; Bhalla, R.C.

    1986-03-01

    The isometric tension development and /sup 45/Ca influx in response to NE and methoxamine stimulation were significantly (P < .05) increased in SHR caudal arteries as compared to WKY. Estimation of /sup 3/H-prazosin binding to the membranes isolated from caudal artery of WKY and SHR showed a single class of high affinity binding sites with Kd values: SHR, 128 +/- 14 pM; WKY, 141 +/- 19 pM and the Bmax values; SHR, 108 +/- 14 fmoles/mg protein; WKY, 113 +/- 21 fmoles/mg protein. Nifedipine inhibition of caudal artery contractions in response to NE stimulation was significantly greater (P < .05) in SHR as compared to WKY. On the other hand, there were no differences between WKY and SHR caudal artery rings either in the isometric tension development, /sup 45/Ca influx or nifedipine inhibition in response to K/sup +/-depolarization. Their results indicate that the increased vascular smooth muscle contraction in SHR in response to NE-stimulation may be due to increased Ca/sup 2 +/ influx through the receptor operated Ca/sup 2 +/ channels.

  19. Extracellular calcium sensing in rat aortic vascular smooth muscle cells

    SciTech Connect

    Smajilovic, Sanela; Hansen, Jakob Lerche; Christoffersen, Tue E.H.

    2006-10-06

    Extracellular calcium (Ca2+o) can act as a first messenger in many cell types through a G protein-coupled receptor, calcium-sensing receptor (CaR). It is still debated whether the CaR is expressed in vascular smooth muscle cells (VSMCs). Here, we report the expression of CaR mRNA and protein in rat aortic VSMCs and show that Ca2+o stimulates proliferation of the cells. The effects of Ca2+o were attenuated by pre-treatment with MAPK kinase 1 (MEK1) inhibitor, as well as an allosteric modulator, NPS 2390. Furthermore, stimulation of the VSMCs with Ca2+o-induced phosphorylation of ERK1/2, but surprisingly did not cause inositol phosphate accumulation. We were not able to conclusively state that the CaR mediates Ca2+o-induced cell proliferation. Rather, an additional calcium-sensing mechanism may exist. Our findings may be of importance with regard to atherosclerosis, an inflammatory disease characterized by abnormal proliferation of VSMCs and high local levels of calcium.

  20. Upregulation of decorin by FXR in vascular smooth muscle cells

    SciTech Connect

    He Fengtian; Zhang Qiuhong; Kuruba, Ramalinga; Gao Xiang; Li Jiang; Li Yong; Gong Wei; Jiang, Yu; Xie Wen; Li Song

    2008-08-08

    Decorin is a member of the family of small leucine-rich proteoglycans that are present in blood vessels and synthesized by vascular smooth muscle cells (VSMCs). Decorin plays complex roles in both normal vascular physiology and the pathogenesis of various types of vascular disorders. However, the mechanisms of regulation of decorin expression in vasculature are not clearly understood. Particularly little information is available about a role of nuclear receptors in the regulation of decorin expression. In the present study, we report that activation of vascular FXR by a specific ligand resulted in upregulation of decorin at the levels of both mRNA and protein. FXR appears to induce decorin expression at a transcriptional level because (1) upregulation of decorin mRNA expression was abolished by the treatment of a transcription inhibitor, actinomycin D; and (2) decorin promoter activity was significantly increased by activation of FXR. Functional analysis of human decorin promoter identified an imperfect inverted repeat DNA motif, IR8 (-2313TGGTCAtagtgtcaTGACCT-2294), as a likely FXR-responsive element that is involved in decorin regulation.

  1. Contraction of gut smooth muscle cells assessed by fluorescence imaging.

    PubMed

    Tokita, Yohei; Akiho, Hirotada; Nakamura, Kazuhiko; Ihara, Eikichi; Yamamoto, Masahiro

    2015-03-01

    Here we discuss the development of a novel cell imaging system for the evaluation of smooth muscle cell (SMC) contraction. SMCs were isolated from the circular and longitudinal muscular layers of mouse small intestine by enzymatic digestion. SMCs were stimulated by test agents, thereafter fixed in acrolein. Actin in fixed SMCs was stained with phalloidin and cell length was determined by measuring diameter at the large end of phalloidin-stained strings within the cells. The contractile response was taken as the decrease in the average length of a population of stimulated-SMCs. Various mediators and chemically identified compounds of daikenchuto (DKT), pharmaceutical-grade traditional Japanese prokinetics, were examined. Verification of the integrity of SMC morphology by phalloidin and DAPI staining and semi-automatic measurement of cell length using an imaging analyzer was a reliable method by which to quantify the contractile response. Serotonin, substance P, prostaglandin E2 and histamine induced SMC contraction in concentration-dependent manner. Two components of DKT, hydroxy-α-sanshool and hydroxy-β-sanshool, induced contraction of SMCs. We established a novel cell imaging technique to evaluate SMC contractility. This method may facilitate investigation into SMC activity and its role in gastrointestinal motility, and may assist in the discovery of new prokinetic agents. PMID:25837933

  2. Human colonic smooth muscle: electrical and contractile activity in vitro.

    PubMed Central

    Gill, R C; Cote, K R; Bowes, K L; Kingma, Y J

    1986-01-01

    Extracellular electrical and contractile activities were recorded in vitro from strips of human colonic smooth muscle obtained at the time of surgery. Serosal electrical activity of longitudinally oriented strips from the taenia and intertaenial region was characterised by continuous oscillation at a frequency of 28 +/- 1/min. Contractions were marked electrically by a series of oscillations upon which spikes were superimposed. The electrical activity recorded from the submucosal surface of circularly oriented strips exhibited oscillations at 24 +/- 4/min, a frequency significantly lower (p less than 0.001) than that recorded from the serosal surface of similar preparations. The contractile force and frequency was dependent upon the part of the colon from which the strip originated; the most powerful contractions were recorded from strips of sigmoid colon. The contractile frequency of circularly oriented strips from the right colon was 6.3 +/- 0.6/min, significantly higher (p less than 0.001) than that of strips from the left colon (3.4 +/- 0.3/min). Stretching these strips caused an increase in contractile frequency to that of the electrical oscillation. PMID:3699550

  3. LAT1 regulates growth of uterine leiomyoma smooth muscle cells.

    PubMed

    Xia Luo; Coon, John S; Su, Emily; Pearson, Elizabeth Kerry; Ping Yin; Ishikawa, Hiroshi; Bulun, Serdar E

    2010-09-01

    L-type amino acid transporter 1 (LAT1) and LAT2 were shown to encode system L, which mediates the Na(+)-independent transport of branched-chain and aromatic amino acids. We demonstrated previously that LAT2 is a progesterone receptor target gene involved in leiomyoma growth. The role of LAT1 in the regulation of human uterine leiomyoma growth, however, remains unelucidated. We herein investigated the function of LAT1 and its progesterone-mediated regulation within human uterine leiomyoma smooth muscle (LSM) cells (n = 8) and tissues (n = 29). In vivo, LAT1 expression was higher in leiomyoma than in myometrial tissue. LAT1 knockdown augmented cell proliferation and viability. Treatment of LSM cells with RU486 markedly increased LAT1 messenger RNA (mRNA) levels but decreased proliferation in a dose-dependent manner. L-type amino acid transporter 1 as a downstream target, however, did not entirely account for this antiproliferative effect of RU486 on LSM cells. Taken together, LAT1 may have a critical and complex role in regulating human leiomyoma cell growth. PMID:20601542

  4. Hydraulic Conductivity of Smooth Muscle Cell-Initiated Arterial Cocultures.

    PubMed

    Mathura, Rishi A; Russell-Puleri, Sparkle; Cancel, Limary M; Tarbell, John M

    2016-05-01

    The purpose of the study was to examine the effects of arterial coculture conditions on the transport properties of several in vitro endothelial cell (EC)-smooth muscle cell (SMC)-porous filter constructs in which SMC were grown to confluence first and then EC were inoculated. This order of culturing simulates the environment of a blood vessel wall after endothelial layer damage due to stenting, vascular grafting or other vascular wall insult. For all coculture configurations examined, we observed that hydraulic conductivity (L p) values were significantly higher than predicted by a resistances-in-series (RIS) model accounting for the L p of EC and SMC measured separately. The greatest increases were observed when EC were plated directly on top of a confluent SMC layer without an intervening filter, presumably mediated by direct EC-SMC contacts that were observed under confocal microscopy. The results are the opposite of a previous study that showed L p was significantly reduced compared to an RIS model when EC were grown to confluency first. The physiological, pathophysiological and tissue engineering implications of these results are discussed. PMID:26265460

  5. Arterial Myogenic Activation through Smooth Muscle Filamin A.

    PubMed

    Retailleau, Kevin; Arhatte, Malika; Demolombe, Sophie; Peyronnet, Rémi; Baudrie, Véronique; Jodar, Martine; Bourreau, Jennifer; Henrion, Daniel; Offermanns, Stefan; Nakamura, Fumihiko; Feng, Yuanyi; Patel, Amanda; Duprat, Fabrice; Honoré, Eric

    2016-03-01

    Mutations in the filamin A (FlnA) gene are frequently associated with severe arterial abnormalities, although the physiological role for this cytoskeletal element remains poorly understood in vascular cells. We used a conditional mouse model to selectively delete FlnA in smooth muscle (sm) cells at the adult stage, thus avoiding the developmental effects of the knockout. Basal blood pressure was significantly reduced in conscious smFlnA knockout mice. Remarkably, pressure-dependent tone of the resistance caudal artery was lost, whereas reactivity to vasoconstrictors was preserved. Impairment of the myogenic behavior was correlated with a lack of calcium influx in arterial myocytes upon an increase in intraluminal pressure. Notably, the stretch activation of CaV1.2 was blunted in the absence of smFlnA. In conclusion, FlnA is a critical upstream element of the signaling cascade underlying the myogenic tone. These findings allow a better understanding of the molecular basis of arterial autoregulation and associated disease states. PMID:26923587

  6. Smooth Muscle Cell-targeted RNA Aptamer Inhibits Neointimal Formation.

    PubMed

    Thiel, William H; Esposito, Carla L; Dickey, David D; Dassie, Justin P; Long, Matthew E; Adam, Joshua; Streeter, Jennifer; Schickling, Brandon; Takapoo, Maysam; Flenker, Katie S; Klesney-Tait, Julia; Franciscis, Vittorio de; Miller, Francis J; Giangrande, Paloma H

    2016-04-01

    Inhibition of vascular smooth muscle cell (VSMC) proliferation by drug eluting stents has markedly reduced intimal hyperplasia and subsequent in-stent restenosis. However, the effects of antiproliferative drugs on endothelial cells (EC) contribute to delayed re-endothelialization and late stent thrombosis. Cell-targeted therapies to inhibit VSMC remodeling while maintaining EC health are necessary to allow vascular healing while preventing restenosis. We describe an RNA aptamer (Apt 14) that functions as a smart drug by preferentially targeting VSMCs as compared to ECs and other myocytes. Furthermore, Apt 14 inhibits phosphatidylinositol 3-kinase/protein kinase-B (PI3K/Akt) and VSMC migration in response to multiple agonists by a mechanism that involves inhibition of platelet-derived growth factor receptor (PDGFR)-β phosphorylation. In a murine model of carotid injury, treatment of vessels with Apt 14 reduces neointimal formation to levels similar to those observed with paclitaxel. Importantly, we confirm that Apt 14 cross-reacts with rodent and human VSMCs, exhibits a half-life of ~300 hours in human serum, and does not elicit immune activation of human peripheral blood mononuclear cells. We describe a VSMC-targeted RNA aptamer that blocks cell migration and inhibits intimal formation. These findings provide the foundation for the translation of cell-targeted RNA therapeutics to vascular disease. PMID:26732878

  7. Identification of possible adenosine receptors in vascular smooth muscle

    SciTech Connect

    Doctrow, S.R.

    1985-01-01

    Adenosine is a vasodilator and has been implicated in increased blood flow in tissues that undergo energy deficiency. During conditions such as hypoxia and ischemia, adenosine is produced and is said to increase blood flow by relaxing the vascular smooth muscle (VSM) lining the resistance vessels. The goal of this research was to identify receptors that might be responsible for adenosine-mediated VSM relaxation. When an insoluble fraction from calf aortic VSM was incubated with /sup 32/P-ATP, two components were phosphorylated. One was identified as myosin light chain by MW, pl, and immunoprecipitation. The other product was identified as phosphatidylinositol-4-phosphate (DPI) by tic. Both phosphorylations were inhibited by adenosine and by 5'-chloro-5'-deoxyadenosine (Cl-Ado). DPI production was much more sensitive to the nucleosides than was myosin phosphorylation. Neither inhibition involved change in cAMP production. Phosphatidylinositol (Pl) kinase in the VSM membranes required magnesium, was activated and solubilized by Triton X-100, and phosphorylated both endogenous and exogenous Pl. Cl-Ado inhibited Pl kinase in a manner competitive with respect to ATP and noncompetitive with respect to Pl. Adenosine and adenosine analogs modified in the ribose ring were inhibitors with potencies comparable to that of Cl-Ado. Adenine nucleotides and purine-modified adenosine analogs were weaker inhibitors than Cl-Ado.

  8. PDT-induced apoptosis in arterial smooth muscles cells

    NASA Astrophysics Data System (ADS)

    Nyamekye, Isaac; Renick, R.; Gilbert, C.; McEwan, Jean R.; Evan, G.; Bishop, Christopher C. R.; Bown, Stephen G.

    1995-03-01

    PDT kills smooth muscle cells (SMC) in vivo and thus prevents intimal hyperplasia after angioplasty. It causes little inflammation and structural integrity of the artery is not compromised. We have studied the process of the SMC death in vitro. Cultured rat SMC (cell line sv40 ATCC) were sensitized with aluminum disulphonated phthalocyanine (AlS2Pc), and then irradiated with 675 nm laser light (2.5 J/cm2). Controls were studied using only sensitizer or laser for treatment. The cells were incubated and the dying process observed with a time lapse video and microscope system. PDT caused a characteristic pattern of death. Cells lost contact with neighbors, shrank, and showed hyperactivity and membrane ruffling. The cells imploded into active and condensed membrane bound vesicles which were terminally reduced to residual bodies. These are the morphological changes of apoptosis. The control cells which were given AlS2Pc alone or laser alone showed no death. PDT induced cultured arterial SMC death by apoptosis rather than necrosis. An apoptotic mechanism of cell death in vivo would explain the relative lack of inflammation and local tissue destruction in the face of massive death.

  9. Arteriolar vascular smooth muscle cells: mechanotransducers in a complex environment.

    PubMed

    Hill, Michael A; Meininger, Gerald A

    2012-09-01

    Contraction of small artery (diameters typically less than 250 μm) vascular smooth muscle cells (VSMCs) plays a critical role in local control of blood flow and arterial pressure through its affect on vascular caliber. Specifically, contraction of small arteries in response to increased intraluminal pressure is referred to as the myogenic response and represents an important role for mechanotransduction. Critical questions remain as to how changes in pressure are sensed by VSMCs and transduced across the cell membrane to tune the contractile state of the cell. Recent studies suggest a pivotal role for interactions between VSMCs and extracellular matrix (ECM) proteins. Thus, pressure-induced deformation of ECM proteins and their cell surface receptors (for example, integrins) may initiate contraction and cytoskeletal remodeling through modulation of ion channels, membrane depolarization, increased intracellular Ca(2+) and actomyosin crossbridge cycling. Importantly, it is argued that the contractile properties of small artery VSMCs reflect an intimate and integrated interaction with their extracellular environment and the three-dimensional structure of the vessel wall. PMID:22677491

  10. SREBP inhibits VEGF expression in human smooth muscle cells

    SciTech Connect

    Motoyama, Koka; Fukumoto, Shinya . E-mail: sfukumoto@med.osaka-cu.ac.jp; Koyama, Hidenori; Emoto, Masanori; Shimano, Hitoshi; Maemura, Koji; Nishizawa, Yoshiki

    2006-03-31

    Sterol regulatory element-binding proteins (SREBPs) are transcription factors that regulate expression of genes encoding enzymes for lipid biosynthesis. SREBPs are activated by HMG-CoA reductase inhibitors (statins). Statins have been also reported to suppress vascular endothelial growth factor (VEGF) expression in vascular smooth muscle cells (VSMCs). Therefore, we hypothesized that SREBPs are involved in statin-mediated regulation of VEGF production in VSMCs. SREBP1 was robustly expressed, and was activated by atorvastatin in VSMCs, as demonstrated by increased levels of the mature nuclear form of SREBP1, and increased promoter activities of a reporter containing sterol regulatory elements by atorvastatin. Moreover, overexpression of SREBP1a dose-dependently suppressed VEGF promoter activity. Site-specific mutation or deletion of the proximal Sp1 sites reduced the inhibitory effects of SREBP1a on VEGF promoter activity. These data demonstrated that SREBP1, activated by atorvastatin, suppressed VEGF expression through the indirect interaction with the proximal tandem Sp1 sites in VSMCs.

  11. Protein kinase C, arachidonate metabolism, and tracheal smooth muscle - effects of temperature

    SciTech Connect

    Huang, C.; Baraban, J.; Menkes, H.

    1986-03-01

    Cooling causes airway obstruction in asthma. Contractions of airway smooth muscle may be produced through the phosphatidylinositol cycle and the activation of protein kinase C. Protein kinase C can be activated directly with phorbol esters. The authors studied the effects of temperature on responses to phorbol 12,13-diacetate (PDA) in guinea pig tracheal rings bathed in Krebs-Henseleit solution. At 37/sup 0/C, 1 ..mu..M PDA relaxed the tissue (tension fell 0.60 +/- S.E. 0.04 g). At 27/sub 0/C, 1 ..mu..M PDA contracted the tissue (tension rose 0.050 +/- 0.05 g). In comparison, near maximum contractions produced by 4 ..mu..M carbachol were 2.00 +/- 0.09 g at 37/sub 0/C and 1.90 +/- 0.09 g at 27/sup 0/C. Butler-Gralla et al. showed that phorbol esters may stimulate the release of arachidonic acid from cultured cells. In order to determine whether arachidonate metabolites play a role in responses observed in guinea pig trachea, the authors used indomethacin (a cyclooxygenase inhibitor), FPL 55712 (a leukotriene receptor antagonist) and Na arachidonate. At 37/sup 0/C, 3 ..mu..M indomethacin pretreatment abolished relaxationby 1 uM PDA. At 27/sup 0/C, 10 uM FPL 55712 pretreatment abolished contractions by 1 ..mu..M PDA. Like PDA, 1 ..mu..M Na arachidonate produced relaxation at 37/sup 0/C and contraction at 27/sup 0/C. The authors conclude that the effects of PDA at different temperatures parallel the effects of Na arachidonate. These results suggest that the effects of PDA in the guinea pig trachea are related to the release of endogenous arachidonic acid and that the cyclooxygenase pathway predominates at high temperature and the lipoxygenase pathway predominates at low temperature.

  12. Multum non multa: airway distensibility by forced oscillations.

    PubMed

    Mermigkis, Charalampos; Schiza, Sophia E; Panagou, Panagiotis

    2016-01-01

    Airway distensibility although appears to be unaffected by airway smooth muscle tone probably related to airway remodelling, after bronchodilator treatment is significantly increased in subjects with asthma. We assessed airway distensibity and its first moment derivative in two patients with mild intermittent asthma and normal spirometry. The increase in airway distensibility after bronchodilation measured at the tidal volume range during quiet breathing by forced oscillations was not accompanied by a change in its first moment, while the latter showed a significant increase in a second patient after anti-inflammatory treatment. It appears that airway distensibility is sensitive to reduction of bronchial smooth muscle tone after bronchodilation, but in addition its first moment might provide information on a change of both bronchial smooth muscle tone and small airways inflammation. PMID:27374218

  13. Phosphorylation of the 27-kDa heat shock protein via p38 MAP kinase and MAPKAP kinase in smooth muscle.

    PubMed

    Larsen, J K; Yamboliev, I A; Weber, L A; Gerthoffer, W T

    1997-11-01

    The 27-kDa heat shock protein (HSP27) is expressed in a variety of tissues in the absence of stress and is thought to regulate actin filament dynamics, possibly by a phosphorylation/dephosphorylation mechanism. HSP27 has also been suggested to be involved in contraction of intestinal smooth muscle. We have investigated phosphorylation of HSP27 in airway smooth muscle in response to the muscarinic agonist carbachol. Carbachol increased 32P incorporation into canine tracheal HSP27 and induced a shift in the distribution of charge isoforms on two-dimensional gels to more acidic, phosphorylated forms. The canine HSP27 amino acid sequence includes three serine residues corresponding to sites in human HSP27 known to be phosphorylated by mitogen-activated protein kinase-activated protein (MAPKAP) kinase-2. To determine whether muscarinic receptors are coupled to a "stress response" pathway in smooth muscle culminating in phosphorylation of HSP27, we assayed MAPKAP kinase-2 activity and tyrosine phosphorylation of p38 mitogen-activated protein (MAP) kinase, the enzyme thought to activate MAPKAP kinase-2. Recombinant canine HSP27 expressed in Escherichia coli was a substrate for MAPKAP kinase-2 in vitro as well as a substrate for endogenous smooth muscle HSP27 kinase, which was activated by carbachol. Carbachol also increased tyrosine phosphorylation of p38 MAP kinase. SB-203580, an inhibitor of p38 MAP kinases, reduced activation of endogenous HSP27 kinase activity and blocked the shift in HSP27 charge isoforms to acidic forms. We suggest that HSP27 in airway smooth muscle, in addition to being a stress response protein, is phosphorylated by a receptor-initiated signaling cascade involving muscarinic receptors, tyrosine phosphorylation of p38 MAP kinase, and activation of MAPKAP kinase-2. PMID:9374719

  14. Pharmacological modulation of sarcoplasmic reticulum function in smooth muscle.

    PubMed

    Laporte, Régent; Hui, Adrian; Laher, Ismail

    2004-12-01

    The sarco/endoplasmic reticulum (SR/ER) is the primary storage and release site of intracellular calcium (Ca2+) in many excitable cells. The SR is a tubular network, which in smooth muscle (SM) cells distributes close to cellular periphery (superficial SR) and in deeper aspects of the cell (deep SR). Recent attention has focused on the regulation of cell function by the superficial SR, which can act as a buffer and also as a regulator of membrane channels and transporters. Ca2+ is released from the SR via two types of ionic channels [ryanodine- and inositol 1,4,5-trisphosphate-gated], whereas accumulation from thecytoplasm occurs exclusively by an energy-dependent sarco-endoplasmic reticulum Ca2+-ATPase pump (SERCA). Within the SR, Ca2+ is bound to various storage proteins. Emerging evidence also suggests that the perinuclear portion of the SR may play an important role in nuclear transcription. In this review, we detail the pharmacology of agents that alter the functions of Ca2+ release channels and of SERCA. We describe their use and selectivity and indicate the concentrations used in investigating various SM preparations. Important aspects of cell regulation and excitation-contractile activity coupling in SM have been uncovered through the use of such activators and inhibitors of processes that determine SR function. Likewise, they were instrumental in the recent finding of an interaction of the SR with other cellular organelles such as mitochondria. Thus, an appreciation of the pharmacology and selectivity of agents that interfere with SR function in SM has greatly assisted in unveiling the multifaceted nature of the SR. PMID:15602008

  15. Caveolin-3 Promotes a Vascular Smooth Muscle Contractile Phenotype

    PubMed Central

    Gutierrez-Pajares, Jorge L.; Iturrieta, Jeannette; Dulam, Vipin; Wang, Yu; Pavlides, Stephanos; Malacari, Gabriella; Lisanti, Michael P.; Frank, Philippe G.

    2015-01-01

    Epidemiological studies have demonstrated the importance of cardiovascular diseases in Western countries. Among the cell types associated with a dysfunctional vasculature, smooth muscle (SM) cells are believed to play an essential role in the development of these illnesses. Vascular SM cells are key regulators of the vascular tone and also have an important function in the development of atherosclerosis and restenosis. While in the normal vasculature, contractile SM cells are predominant, in atherosclerotic vascular lesions, synthetic cells migrate toward the neointima, proliferate, and synthetize extracellular matrix proteins. In the present study, we have examined the role of caveolin-3 in the regulation of SM cell phenotype. Caveolin-3 is expressed in vivo in normal arterial SM cells, but its expression appears to be lost in cultured SM cells. Our data show that caveolin-3 expression in the A7r5 SM cell line is associated with increased expression of contractility markers such as SM α-actin, SM myosin heavy chain but decreased expression of the synthetic phenotype markers such as p-Elk and Klf4. Moreover, we also show that caveolin-3 expression can reduce proliferation upon treatment with LDL or PDGF. Finally, we show that caveolin-3-expressing SM cells are less sensitive to apoptosis than control cells upon treatment with oxidized LDL. Taken together, our data suggest that caveolin-3 can regulate the phenotypic switch between contractile and synthetic SM cells. A better understanding of the factors regulating caveolin-3 expression and function in this cell type will permit the development of a better comprehension of the factors regulating SM function in atherosclerosis and restenosis. PMID:26664898

  16. Agonist-induced Ca2+ Sensitization in Smooth Muscle

    PubMed Central

    Artamonov, Mykhaylo V.; Momotani, Ko; Stevenson, Andra; Trentham, David R.; Derewenda, Urszula; Derewenda, Zygmunt S.; Read, Paul W.; Gutkind, J. Silvio; Somlyo, Avril V.

    2013-01-01

    Many agonists, acting through G-protein-coupled receptors and Gα subunits of the heterotrimeric G-proteins, induce contraction of smooth muscle through an increase of [Ca2+]i as well as activation of the RhoA/RhoA-activated kinase pathway that amplifies the contractile force, a phenomenon known as Ca2+ sensitization. Gα12/13 subunits are known to activate the regulator of G-protein signaling-like family of guanine nucleotide exchange factors (RhoGEFs), which includes PDZ-RhoGEF (PRG) and leukemia-associated RhoGEF (LARG). However, their contributions to Ca2+-sensitized force are not well understood. Using permeabilized blood vessels from PRG(−/−) mice and a new method to silence LARG in organ-cultured blood vessels, we show that both RhoGEFs are activated by the physiologically and pathophysiologically important thromboxane A2 and endothelin-1 receptors. The co-activation is the result of direct and independent activation of both RhoGEFs as well as their co-recruitment due to heterodimerization. The isolated recombinant C-terminal domain of PRG, which is responsible for heterodimerization with LARG, strongly inhibited Ca2+-sensitized force. We used photolysis of caged phenylephrine, caged guanosine 5′-O-(thiotriphosphate) (GTPγS) in solution, and caged GTPγS or caged GTP loaded on the RhoA·RhoGDI complex to show that the recruitment and activation of RhoGEFs is the cause of a significant time lag between the initial Ca2+ transient and phasic force components and the onset of Ca2+-sensitized force. PMID:24106280

  17. Regulation of smooth muscle cell phenotype by glycosaminoglycan identity.

    PubMed

    Qu, Xin; Jimenez-Vergara, Andrea Carolina; Munoz-Pinto, Dany J; Ortiz, Diana; McMahon, Rebecca E; Cristancho, Deissy; Becerra-Bayona, Silvia; Guiza-Arguello, Viviana; Grande-Allen, K Jane; Hahn, Mariah S

    2011-03-01

    The retention of lipoproteins in the arterial intima is an initial event in early atherosclerosis and occurs, in part, through interactions between negatively charged glycosaminoglycans (GAGs) and the positively charged residues of apolipoproteins. Smooth muscle cells (SMCs) which infiltrate into the lipoprotein-enriched intima have been observed to transform into lipid-laden foam cells. This phenotypic switch is associated with SMC acquisition of a macrophage-like capacity to phagocytose lipoproteins and/or of an adipocyte-like capacity to synthesize fatty acids de novo. The aim of the present work was to explore the impact of GAG identity on SMC foam cell formation using a scaffold environment intended to be mimetic of early atherosclerosis. In these studies, we focused on chondroitin sulfate C (CSC), dermatan sulfate (DS), and an intermediate molecular weight hyaluronan (HAIMW, ∼400 kDa), the levels and/or distribution of each of which are significantly altered in atherosclerosis. DS hydrogels were associated with greater SMC phagocytosis of apolipoprotein B than HAIMW gels. Similarly, only SMCs in DS constructs maintained increased expression of the adipocyte marker A-FABP relative to HAIMW gels over 35 days of culture. The increased SMC foam cell phenotype in DS hydrogels was reflected in a corresponding decrease in SMC myosin heavy chain expression in these constructs relative to HAIMW gels at day 35. In addition, this DS-associated increase in foam cell formation was mirrored in an increased SMC synthetic phenotype, as evidenced by greater levels of collagen type I and glucose 6-phosphate dehydrogenase in DS gels than in HAIMW gels. Combined, these results support the increasing body of literature that suggests a critical role for DS-bearing proteoglycans in early atherosclerosis. PMID:21094702

  18. Distribution of a lanthanide (147 Pm) in vascular smooth muscle.

    PubMed

    Weiss, G B; Goodman, F R

    1976-08-01

    In order to ascertain whether trivalent rare earth ions such as lanthanum (La+++) penetrate the cell membrane under physiological conditions, the extracellular and cellular distribution of promethium (147 Pm), a carrier-free rare earth radioisotope, was examined in rabbit aortic smooth muscle. As the duration of incubation was lengthened, uptake of 147Pm continued to increase; it was inhibited by La+++ and other rare earth ions (Nd+++, Lu+++) only when the 147 Pm/rare earth concentration ratio exceeded 1:10(6). However, equally high concentrations of Ca++ had no effect on 147Pm uptake. Efflux of 147Pm was only transiently increased by 1.5 mM La+++, and exposure to 0.05 mM EDTA elicited an increased 147Pm efflux with both transient and maintained components. The magnitude of the EDTA-induced increase in 147 Pm efflux was similar over a 30-fold range of EDTA concentration (0.05-1.5 mM); the limiting factor for 147Pm efflux is the rate of 147Pm desorption from the tissue rather than the extracellular concentration of EDTA. Loss of 147Pm in the presence of 0.05 mM EDTA could be described in terms of two specific washout components (the more rapid of which included 147Pm within the extracellular space and the slower of which had half-times of washout of approximately 7-10 minutes). Uptake of 147Pm was inhibited by lowering the incubation solution temperature to 0 degrees C or by procaine. However, concentrations of metabolic inhibitors (iodoacetate and dinitrophenol) which diminish loss of Ca++ from the cell did not decrease either the uptake or efflux of 147Pm. Thus, significant quantities of 147Pm do not appear to be accumulated within the cell or transported out of the cell; distribution of 147Pm can be most simply described in terms of a binding at and desorption from surface acessible fiber sites. PMID:820850

  19. Interaction of chicken gizzard smooth muscle calponin with brain microtubules.

    PubMed

    Fujii, T; Hiromori, T; Hamamoto, M; Suzuki, T

    1997-08-01

    Calponin, a major actin-, tropomyosin-, and calmodulin-binding protein in smooth muscle, interacted with tubulin, a main constituent of microtubules, in a concentration-dependent fashion in vitro. The apparent K(d) value of calponin to tubulin was calculated to be 5.2 microM with 2 mol of calponin maximally bound per 1 mol of tubulin. At low ionic strength, tubulin bound to calponin immobilized on Sepharose 4B, and the bound protein was released at about 270 mM NaCl. Chemical cross-linking experiments showed that a 1:1 molar covalent complex of calponin and tubulin was produced. The amount of calponin bound to microtubules decreased with increasing ionic strength or Ca2+ concentration. The addition of calmodulin or S100 to the mixture of calponin and microtubule proteins caused the removal of calponin from microtubules in the presence of Ca2+, but not in the presence of EGTA. Calponin-related proteins including tropomyosin, SM22, and caldesmon had little effect on the calponin binding to microtubules, whereas MAP2 inhibited the binding. Interestingly, there was little, if any, effect of mycalolide B-treated actin on the binding of calponin to microtubules. Furthermore, only about 20% of calponin-F-actin interaction was inhibited in the presence of an excess amount of tubulin (4 mol per mol of calponin), indicating that tubulin binds to calponin at a different site from that of actin. Compared with MAP2, calponin had little effect on microtubule polymerization. PMID:9378712

  20. Segregation of striated and smooth muscle lineages by a Notch-dependent regulatory network

    PubMed Central

    2014-01-01

    Background Lineage segregation from multipotent epithelia is a central theme in development and in adult stem cell plasticity. Previously, we demonstrated that striated and smooth muscle cells share a common progenitor within their epithelium of origin, the lateral domain of the somite-derived dermomyotome. However, what controls the segregation of these muscle subtypes remains unknown. We use this in vivo bifurcation of fates as an experimental model to uncover the underlying mechanisms of lineage diversification from bipotent progenitors. Results Using the strength of spatio-temporally controlled gene missexpression in avian embryos, we report that Notch harbors distinct pro-smooth muscle activities depending on the duration of the signal; short periods prevent striated muscle development and extended periods, through Snail1, promote cell emigration from the dermomyotome towards a smooth muscle fate. Furthermore, we define a Muscle Regulatory Network, consisting of Id2, Id3, FoxC2 and Snail1, which acts in concert to promote smooth muscle by antagonizing the pro-myogenic activities of Myf5 and Pax7, which induce striated muscle fate. Notch and BMP closely regulate the network and reciprocally reinforce each other’s signal. In turn, components of the network strengthen Notch signaling, while Pax7 silences this signaling. These feedbacks augment the robustness and flexibility of the network regulating muscle subtype segregation. Conclusions Our results demarcate the details of the Muscle Regulatory Network, underlying the segregation of muscle sublineages from the lateral dermomyotome, and exhibit how factors within the network promote the smooth muscle at the expense of the striated muscle fate. This network acts as an exemplar demonstrating how lineage segregation occurs within epithelial primordia by integrating inputs from competing factors. PMID:25015411

  1. Muscarinic M2 receptors in bovine tracheal smooth muscle: discrepancies between binding and function.

    PubMed

    Roffel, A F; Elzinga, C R; Van Amsterdam, R G; De Zeeuw, R A; Zaagsma, J

    1988-08-01

    Previous work showing that AF-DX 116, a cardioselective muscarinic antagonist in functional experiments, does not discriminate between muscarinic receptors in bovine cardiac and tracheal membranes has been extended. In addition to AF-DX 116 we used the muscarinic antagonists, atropine, pirenzepine, 4-DAMP methobromide, gallamine, hexahydrosiladifenidol and methoctramine, in radioligand binding experiments on bovine cardiac left ventricular and tracheal smooth muscle membranes. The functional antagonism of the methacholine-induced contraction of bovine tracheal smooth muscle strips was also evaluated. An excellent correlation was found for all compounds between the binding affinities for muscarinic receptors in cardiac and tracheal smooth muscle membranes; moreover, the affinities found in cardiac membranes correspond with the pA2 values reported for atrial preparations of rat and guinea pig. However, significant and occasionally marked discrepancies were found between binding and functional affinities of these muscarinic antagonists on bovine tracheal smooth muscle. PMID:3215279

  2. Mebendazole Reduces Vascular Smooth Muscle Cell Proliferation and Neointimal Formation Following Vascular Injury in Mice

    PubMed Central

    Wang, Jintao; Wang, Hui; Guo, Chiao; Luo, Wei; Lawler, Alyssa; Reddy, Aswin; Wang, Julia; Sun, Eddy B.; Eitzman, Daniel T.

    2014-01-01

    Mebendazole is an antihelminthic drug that exerts its effects via interference with microtubule function in parasites. To determine the utility of mebendazole as a potential treatment for vascular diseases involving proliferation of vascular smooth muscle cells, the effects of mebendazole on vascular smooth muscle cell proliferation were tested in vitro and in a mouse model of arterial injury. In vitro, mebendazole inhibited proliferation and migration of murine vascular smooth muscle cells and this was associated with altered intracellular microtubule organization. To determine in vivo effects of mebendazole following vascular injury, femoral arterial wire injury was induced in wild-type mice treated with either mebendazole or placebo control. Compared with placebo-treated mice, mebendazole-treated mice formed less neointima at the site of injury. Mebendazole is effective at inhibiting vascular smooth muscle cell proliferation and migration, and neointimal formation following arterial injury in mice. PMID:24587248

  3. ROLE OF ACETYLCHOLINE IN RHYTHMIC SPONTANEOUS CONTRACTIONS OF RAT'S DUODENAL SMOOTH MUSCLE

    EPA Science Inventory

    The purpose of the study is to reexamine the role of endogenous acetylcholine in spontaneous contractions of smooth muscle whose contractions are associated with cell metabolism. The study does not attempt to define the role of endogenous acetylcholine.

  4. Cyclic GMP alters Ca exchange in vascular smooth muscle

    SciTech Connect

    Magliola, L.; Bailey, B.; Jones, A.W.

    1986-03-05

    Contraction and /sup 42/K efflux from vascular smooth muscle stimulated either by norepinephrine (NE) or by K-depolarization is dependent on an increase in cytosolic Ca concentration. The purpose of this study was to determine if cyclic GMP (cGMP) inhibited these processes and if inhibition was secondary to the action of cGMP on Ca movements. Basal cGMP content of rat aorta was 1.2 fmol/mg wet wt. Sodium nitroprusside (NP) increased cGMP approx.2-fold at 1 nM and approx.750-fold at 1 ..mu..M with no effect on cAMP levels. A 5 min pretreatment with NP (1 ..mu..M) completely prevented tension development induced by 3 ..mu..M NE. The same concentration of NP also inhibited NE-stimulated /sup 42/K and /sup 45/Ca efflux > 90 and > 80%, respectively. Removal of NP in the continued presence of NE (3 ..mu..M) caused recovery of the /sup 42/K efflux response to approx.75% of control with a half-time of approx.2.5 min. NP (1 ..mu..M) also caused a rapid relaxation of aorta contracted with 3 ..mu..M NE and a loss of the /sup 42/K efflux response with half-times of 2-3 min. In contrast, 100 ..mu..M NP produced only a 50% inhibition of contraction induced by high K (55 mM). Also, NP (1 ..mu..M) inhibited K-stimulated /sup 42/K efflux only approx.25%. These results demonstrate both a concentration- and a time-dependent relationship between increases in cGMP induced by NP and decreases in NE-stimulated contraction, /sup 42/K and /sup 45/Ca effluxes. They also indicate that the sensitivity of NE-induced contraction and /sup 42/K efflux to NP is greater than that induced by high K. These studies suggest that cGMP modulates the control sites for Ca exchange in the plasma membrane and sarcoplasmic reticulum.

  5. 3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells

    PubMed Central

    Luo, Tong; Chen, Huan; Kassab, Ghassan S.

    2016-01-01

    Aims The 3D geometry of individual vascular smooth muscle cells (VSMCs), which are essential for understanding the mechanical function of blood vessels, are currently not available. This paper introduces a new 3D segmentation algorithm to determine VSMC morphology and orientation. Methods and Results A total of 112 VSMCs from six porcine coronary arteries were used in the analysis. A 3D semi-automatic segmentation method was developed to reconstruct individual VSMCs from cell clumps as well as to extract the 3D geometry of VSMCs. A new edge blocking model was introduced to recognize cell boundary while an edge growing was developed for optimal interpolation and edge verification. The proposed methods were designed based on Region of Interest (ROI) selected by user and interactive responses of limited key edges. Enhanced cell boundary features were used to construct the cell’s initial boundary for further edge growing. A unified framework of morphological parameters (dimensions and orientations) was proposed for the 3D volume data. Virtual phantom was designed to validate the tilt angle measurements, while other parameters extracted from 3D segmentations were compared with manual measurements to assess the accuracy of the algorithm. The length, width and thickness of VSMCs were 62.9±14.9μm, 4.6±0.6μm and 6.2±1.8μm (mean±SD). In longitudinal-circumferential plane of blood vessel, VSMCs align off the circumferential direction with two mean angles of -19.4±9.3° and 10.9±4.7°, while an out-of-plane angle (i.e., radial tilt angle) was found to be 8±7.6° with median as 5.7°. Conclusions A 3D segmentation algorithm was developed to reconstruct individual VSMCs of blood vessel walls based on optical image stacks. The results were validated by a virtual phantom and manual measurement. The obtained 3D geometries can be utilized in mathematical models and leads a better understanding of vascular mechanical properties and function. PMID:26882342

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

    PubMed

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

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments. PMID:25734774

  7. Emodin augments calcium activated chloride channel in colonic smooth muscle cells by Gi/Go protein.

    PubMed

    Xu, Long; Ting-Lou; Lv, Nonghua; Zhu, Xuan; Chen, Youxiang; Yang, Jing

    2009-08-01

    Emodin is a natural anthraquinone in rhubarb. It has been identified as a prokinetic drug for gastrointestinal motility in Chinese traditional medicine. Emodin contracts smooth muscle by increasing the concentration of intracellular Ca(2+). In many smooth muscles, increasing intracellular Ca(2+) activates Ca(2+)-activated Cl(-) channels (ClCA). The study was aimed to investigate the effects of emodin on ClCA channels in colonic smooth muscle. 4 channel physiology signal acquire system was used to measure isometric contraction of smooth muscle strips. ClCA currents were recorded by EPC10 with perforated whole cell model. Emodin contracted strips and cells in colonic smooth muscle and augmented ClCA currents. Niflumic acid (NFA) and 4', 4'-diisothiostilbene-2, 2-disulfonic acid (DIDS) blocked the effects. Gi/Go protein inhibits protein kinase A (PKA) and protein kinase C (PKC), and PKA and PKC reduced ClCA currents. Pertussis toxin (PTX, a special inhibitor of Gi/Go protein), 8-bromoadenosine 38, 58-cyclic monophosphate (8-BrcAMP, a membrane-permeant protein kinase A activator) and Phorbol-12-myristate-13-acetate (PMA, a membrane-permeant protein kinase C activator) inhibited the effects on ClCA currents significantly. Our findings suggest that emodin augments ClCA channels to contract smooth muscle in colon, and the effect is induced mostly by enhancement of membrane Gi/Go protein signal transducer pathway. PMID:19409890

  8. Adult human arterial smooth muscle cells in primary culture. Modulation from contractile to synthetic phenotype.

    PubMed

    Thyberg, J; Nilsson, J; Palmberg, L; Sjölund, M

    1985-01-01

    Smooth muscle cells were isolated enzymatically from adult human arteries, grown in primary culture in medium containing 10% whole blood serum, and studied by transmission electron microscopy and [3H]thymidine autoradiography. In the intact arterial wall and directly after isolation, each smooth muscle cell had a nucleus with a wide peripheral zone of condensed chromatin and a cytoplasm dominated by myofilament bundles with associated dense bodies. After 1-2 days of culture, the cells had attached to the substrate and started to spread out. At the same time, a characteristic fine-structural modification took place. It included nuclear enlargement, dispersion of the chromatin and formation of large nucleoli. Moreover, myofilament bundles disappeared and an extensive rough endoplasmic reticulum and a large Golgi complex were organized in the cytoplasm. This morphological transformation of the cells was completed in 3-4 days. It was accompanied by initiation of DNA replication and mitosis. The observations demonstrate that adult human arterial smooth muscle cells, when cultivated in vitro, pass through a phenotypic modulation of the same type as arterial smooth muscle cells from experimental animals. This modulation gives the cells morphological and functional properties resembling those of the modified smooth muscle cells found in fibroproliferative lesions of atherosclerosis. Further studies of the regulation of smooth muscle phenotype and growth may provide important clues for a better understanding of the pathogenesis of atherosclerosis. PMID:3967287

  9. Recruitment of β-catenin to N-cadherin is necessary for smooth muscle contraction.

    PubMed

    Wang, Tao; Wang, Ruping; Cleary, Rachel A; Gannon, Olivia J; Tang, Dale D

    2015-04-01

    β-Catenin is a key component that connects transmembrane cadherin with the actin cytoskeleton at the cell-cell interface. However, the role of the β-catenin/cadherin interaction in smooth muscle has not been well characterized. Here stimulation with acetylcholine promoted the recruitment of β-catenin to N-cadherin in smooth muscle cells/tissues. Knockdown of β-catenin by lentivirus-mediated shRNA attenuated smooth muscle contraction. Nevertheless, myosin light chain phosphorylation at Ser-19 and actin polymerization in response to contractile activation were not reduced by β-catenin knockdown. In addition, the expression of the β-catenin armadillo domain disrupted the recruitment of β-catenin to N-cadherin. Force development, but not myosin light chain phosphorylation and actin polymerization, was reduced by the expression of the β-catenin armadillo domain. Furthermore, actin polymerization and microtubules have been implicated in intracellular trafficking. In this study, the treatment with the inhibitor latrunculin A diminished the interaction of β-catenin with N-cadherin in smooth muscle. In contrast, the exposure of smooth muscle to the microtubule depolymerizer nocodazole did not affect the protein-protein interaction. Together, these findings suggest that smooth muscle contraction is mediated by the recruitment of β-catenin to N-cadherin, which may facilitate intercellular mechanotransduction. The association of β-catenin with N-cadherin is regulated by actin polymerization during contractile activation. PMID:25713069

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

    PubMed Central

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

    2015-01-01

    The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments. PMID:25734774

  11. Increased Vascular Smooth Muscle Contractility in TRPC6−/− Mice

    PubMed Central

    Dietrich, Alexander; Mederos y Schnitzler, Michael; Gollasch, Maik; Gross, Volkmar; Storch, Ursula; Dubrovska, Galyna; Obst, Michael; Yildirim, Eda; Salanova, Birgit; Kalwa, Hermann; Essin, Kirill; Pinkenburg, Olaf; Luft, Friedrich C.; Gudermann, Thomas; Birnbaumer, Lutz

    2005-01-01

    Among the TRPC subfamily of TRP (classical transient receptor potential) channels, TRPC3, -6, and -7 are gated by signal transduction pathways that activate C-type phospholipases as well as by direct exposure to diacylglycerols. Since TRPC6 is highly expressed in pulmonary and vascular smooth muscle cells, it represents a likely molecular candidate for receptor-operated cation entry. To define the physiological role of TRPC6, we have developed a TRPC6-deficient mouse model. These mice showed an elevated blood pressure and enhanced agonist-induced contractility of isolated aortic rings as well as cerebral arteries. Smooth muscle cells of TRPC6-deficient mice have higher basal cation entry, increased TRPC-carried cation currents, and more depolarized membrane potentials. This higher basal cation entry, however, was completely abolished by the expression of a TRPC3-specific small interference RNA in primary TRPC6−/− smooth muscle cells. Along these lines, the expression of TRPC3 in wild-type cells resulted in increased basal activity, while TRPC6 expression in TRPC6−/− smooth muscle cells reduced basal cation influx. These findings imply that constitutively active TRPC3-type channels, which are up-regulated in TRPC6-deficient smooth muscle cells, are not able to functionally replace TRPC6. Thus, TRPC6 has distinct nonredundant roles in the control of vascular smooth muscle tone. PMID:16055711

  12. Chronic effects of mechanical force on airways.

    PubMed

    Tschumperlin, Daniel J; Drazen, Jeffrey M

    2006-01-01

    Airways are embedded in the mechanically dynamic environment of the lung. In utero, this mechanical environment is defined largely by fluid secretion into the developing airway lumen. Clinical, whole lung, and cellular studies demonstrate pivotal roles for mechanical distention in airway morphogenesis and cellular behavior during lung development. In the adult lung, the mechanical environment is defined by a dynamic balance of surface, tissue, and muscle forces. Diseases of the airways modulate both the mechanical stresses to which the airways are exposed as well as the structure and mechanical behavior of the airways. For instance, in asthma, activation of airway smooth muscle abruptly changes the airway size and stress state within the airway wall; asthma also results in profound remodeling of the airway wall. Data now demonstrate that airway epithelial cells, smooth muscle cells, and fibroblasts respond to their mechanical environment. A prominent role has been identified for the epithelium in transducing mechanical stresses, and in both the fetal and mature airways, epithelial cells interact with mesenchymal cells to coordinate remodeling of tissue architecture in response to the mechanical environment. PMID:16460284

  13. Blockade by calmodulin inhibitors of Ca2+ channels in smooth muscle from rat vas deferens.

    PubMed Central

    Nakazawa, K.; Higo, K.; Abe, K.; Tanaka, Y.; Saito, H.; Matsuki, N.

    1993-01-01

    1. Effects of three compounds which are used as calmodulin inhibitors (trifluoperazine, W-7 and calmidazolium) on Ca2+ channels were investigated in smooth muscle from rat vas deferens. 2. All three calmodulin inhibitors relaxed the smooth muscle precontracted by a high concentration of KCl (63.7 mM). The order of potency for the relaxation was trifluoperazine > W-7 > calmidazolium. 3. In binding studies using a microsomal fraction of vas deferens, all these calmodulin inhibitors displaced specific [3H]-nimodipine binding. Trifluoperazine and W-7 inhibited the binding at concentrations that relaxed the smooth muscle whereas calmidazolium inhibited at concentrations much lower than those necessary for muscle relaxation. 4. Ba2+ current flowing through voltage-gated Ca2+ channels was measured under whole-cell voltage-clamp conditions in isolated smooth muscle cells. The Ba2+ current was suppressed by the three calmodulin inhibitors in the concentration-range where inhibition of [3H]-nimodipine binding was observed. Neither voltage-dependence nor the inactivation time course of Ba2+ current were affected by these compounds. 5. The results suggest that the calmodulin inhibitors directly block Ca2+ channels in the smooth muscle cells. The channel inhibition by trifluoperazine and W-7, but perhaps not that by calmidazolium, may be responsible for the muscle relaxation observed with these compounds. PMID:8495236

  14. OUABAIN- AND MARINOBUFAGENIN-INDUCED PROLIFERATION OF HUMAN UMBILICAL VEIN SMOOTH MUSCLE CELLS AND A RAT VASCULAR SMOOTH MUSCLE CELL LINE, A7R5

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied the growth-promoting effects of 2 sodium pump-selective cardiotonic steroids, ouabain and marinobufagenin, on cultured cells from vascular smooth muscle (VSMCs) from human umbilical vein and a rat VSMC line, A7r5. Both ouabain and marinobufagenin activated proliferation of these cells in...

  15. Forkhead Box M1 Transcriptional Factor is Required for Smooth Muscle Cells during Embryonic Development of Blood Vessels and Esophagus

    PubMed Central

    Ustiyan, Vladimir; Wang, I-Ching; Ren, Xiaomeng; Zhang, Yufang; Snyder, Jonathan; Xu, Yan; Wert, Susan E.; Lessard, James L.; Kalin, Tanya V.; Kalinichenko, Vladimir V.

    2009-01-01

    The Forkhead Box m1 (Foxm1 or Foxm1b) transcription factor (previously called HFH-11B, Trident, Win, or MPP2) is expressed in a variety of tissues during embryogenesis, including vascular, airway and intestinal smooth muscle cells (SMC). Although global deletion of Foxm1 in Foxm1−/− mice is lethal in the embryonic period due to multiple abnormalities in the liver, heart and lung, the specific role of Foxm1 in SMC remains unknown. In the present study, Foxm1 was deleted conditionally in the developing SMC (smFoxm1−/− mice). The majority of smFoxm1−/− mice died immediately after birth due to severe pulmonary hemorrhage, and structural defects in arterial wall and esophagus. Although Foxm1 deletion did not influence SMC differentiation, decreased proliferation of SMC was found in smFoxm1−/− blood vessels and esophagus. Depletion of Foxm1 in cultured SMC caused G2 arrest and decreased numbers of cells undergoing mitosis. Foxm1-deficiency in vitro and in vivo was associated with reduced expression of cell cycle regulatory genes, including cyclin B1, Cdk1-activator Cdc25b phosphatase, Polo-like 1 and JNK1 kinases, and cMyc transcription factor. Foxm1 is critical for proliferation of smooth muscle cells and is required for proper embryonic development of blood vessels and esophagus. PMID:19835856

  16. From depolarization-dependent contractions in gastrointestinal smooth muscle to aortic pulse-synchronized contractions

    PubMed Central

    Marion, Sarah B; Mangel, Allen W

    2014-01-01

    For decades, it was believed that the diameter of gastrointestinal smooth muscle cells is sufficiently narrow, and that the diffusion of calcium across the plasma membrane is sufficient, to support contractile activity. Thus, depolarization-triggered release of intracellular calcium was not believed to be operative in gastrointestinal smooth muscle. However, after the incubation of muscle segments in solutions devoid of calcium and containing the calcium chelator ethylene glycol tetraacetic acid, an alternative electrical event occurred that was distinct from normal slow waves and spikes. Subsequently, it was demonstrated in gastrointestinal smooth muscle segments that membrane depolarization associated with this alternative electrical event triggered rhythmic contractions by release of intracellular calcium. Although this concept of depolarization-triggered calcium release was iconoclastic, it has now been demonstrated in multiple gastrointestinal smooth muscle preparations. On the basis of these observations, we investigated whether a rhythmic electrical and mechanical event would occur in aortic smooth muscle under the same calcium-free conditions. The incubation of aortic segments in a solution with no added calcium plus ethylene glycol tetraacetic acid induced a fast electrical event without corresponding tension changes. On the basis of the frequency of these fast electrical events, we pursued, contrary to what has been established dogma for more than three centuries, the question of whether the smooth muscle wall of the aorta undergoes rhythmic activation during the cardiac cycle. As with depolarization-triggered contractile activity in gastrointestinal smooth muscle, it was “well known” that rhythmic activation of the aorta does not occur in synchrony with the heartbeat. In a series of experiments, however, it was demonstrated that rhythmic contractions occur in the aortic wall in synchrony with the heartbeat and share a common pacemaker with the heart

  17. Smooth muscle NOS, colocalized with caveolin-1, modulates contraction in mouse small intestine

    PubMed Central

    El-Yazbi, Ahmed F; Cho, Woo Jung; Cena, Jonathan; Schulz, Richard; Daniel, Edwin E

    2008-01-01

    Neuronal nitric oxide synthase (nNOS) in myenteric neurons is activated during peristalsis to produce nitric oxide which relaxes intestinal smooth muscle. A putative nNOS is also found in the membrane of intestinal smooth muscle cells in mouse and dog. In this study we studied the possible functions of this nNOS expressed in mouse small intestinal smooth muscle colocalized with caveolin-1(Cav-1). Cav-1 knockout mice lacked nNOS in smooth muscle and provided control tissues. 60 mM KCl was used to increase intracellular [Ca2+] through L-type Ca2+ channel opening and stimulate smooth muscle NOS activity in intestinal tissue segments. An additional contractile response to LNNA (100 μM, NOS inhibitor) was observed in KCl-contracted tissues from control mice and was almost absent in tissues from Cav-1 knockout mice. Disruption of caveolae with 40 mM methyl-β cyclodextrin in tissues from control mice led to the loss of Cav-1 and nNOS immunoreactivity from smooth muscle as shown by immunohistochemistry and a reduction in the response of these tissues to N-ω-nitro-L-arginine (LNNA). Reconstitution of membrane cholesterol using water soluble cholesterol in the depleted segments restored the immunoreactivity and the response to LNNA added after KCl. Nicardipine (1 μM) blocked the responses to KCl and LNNA confirming the role of L-type Ca2+ channels. ODQ (1 μM, soluble guanylate cyclase inhibitor) had the same effect as inhibition of NOS following KCl. We conclude that the activation of nNOS, localized in smooth muscle caveolae, by calcium entering through L-type calcium channels triggers nitric oxide production which modulates muscle contraction by a cGMP-dependent mechanism. PMID:18400048

  18. Developmental changes in expression of contractile and cytoskeletal proteins in human aortic smooth muscle.

    PubMed

    Glukhova, M A; Frid, M G; Koteliansky, V E

    1990-08-01

    To describe phenotypic changes of human aortic smooth muscle cells (SMCs), proportion of smooth muscle and nonmuscle variants of actin, myosin heavy chains (MHCs), vinculin, and caldesmon, during prenatal and several months of postnatal development was determined. In aortic SMCs from 9-10-week-old fetus, both nonmuscle and smooth muscle-specific variants of all four proteins were present, however, the nonmuscle forms were more abundant. During development, a shift towards the expression of muscle-specific variants was observed, although the time course of changes in protein variant content was not similar for all the proteins studied. By the 24th week of gestation, fractional content of alpha-smooth muscle actin and smooth muscle MHCs was rather close to that in the mature SMCs, and comprised approximately 80 and 90%, respectively, of the levels characteristic of SMCs from adult aortic media. On the contrary, fractional ratio of meta-vinculin and 150-kDa caldesmon was still rather low in the aorta from the 24-week-old fetus, did not increase in a 2-month-old child aorta, and did not reach the level characteristic of mature SMCs even in the 6-month-old child aorta. Thus changes in alpha-smooth muscle actin and smooth muscle MHC fractional content occur mainly during the prenatal period of development, before the 24th week of gestation; while meta-vinculin and the 150-kDa caldesmon proportion increases mainly in the postnatal period, during several months after birth. In the "Discussion," phenotypes of SMCs from developing aorta were compared to those from different layers of the adult aortic wall. PMID:2376586

  19. Smooth muscle and purinergic contraction of the human, rabbit, rat, and mouse testicular capsule.

    PubMed

    Banks, Frederick C L; Knight, Gillian E; Calvert, Robert C; Turmaine, Mark; Thompson, Cecil S; Mikhailidis, Dimitri P; Morgan, Robert J; Burnstock, Geoffrey

    2006-03-01

    The smooth-muscle cells of the testicular capsule (tunica albuginea) of man, rat, and mouse were examined by electron microscopy. They were characteristically flattened, elongated, branching cells and diffusely incorporated into the collagenous matrix and did not form a compact muscle layer. Contractile and synthetic smooth-muscle cell phenotypes were identified. Nerve varicosities in close apposition to smooth muscle were seen in human tissue. Contractions induced by adenosine 5'-triphosphate (ATP), alpha, beta-methylene ATP, noradrenaline (NA), acetylcholine (ACh), and electrical field stimulation (EFS) of autonomic nerves were investigated. Nerve-mediated responses of the rabbit and human tunica albuginea were recorded. The EFS-induced human responses were completely abolished by prazosin. In the rabbit, EFS-induced contractile responses were reduced by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid by 36% and by prazosin by 77%. Both antagonists together almost completely abolished all EFS-induced contractions. The human tunica albuginea was contracted by NA, ATP, and alpha, beta-methylene ATP, but not by ACh. The rabbit and rat tunica albuginea were contracted by NA, ATP, alpha, beta-methylene ATP, and ACh. The mouse tunica albuginea was contracted by ACh, ATP, and alpha, beta-methylene ATP, but relaxed to NA. Immunohistochemical studies showed that P2X1 (also known as P2RX1) and P2X2 (also known as P2RX2) receptors were expressed on the smooth muscle of the rodent testicular capsule, expression being less pronounced in man. The testicular capsule of the rat, mouse, rabbit, and man all contain contractile smooth muscle. ATP, released as a cotransmitter from sympathetic nerves, can stimulate the contraction of rabbit smooth muscle. Human, rat, and mouse testicular smooth muscle demonstrated purinergic responsiveness, probably mediated through the P2X1 and/or P2X2 receptors. PMID:16280417

  20. A Simple, Inexpensive Model to Demonstrate How Contraction of GI Longitudinal Smooth Muscle Promotes Propulsion

    ERIC Educational Resources Information Center

    Lujan, Heidi L.; DiCarlo, Stephen E.

    2015-01-01

    Peristalis is a propulsive activity that involves both circular and longitudinal muscle layers of the esophagus, distal stomach, and small and large intestines. During peristalsis, the circular smooth muscle contracts behind (on the orad side) the bolus and relaxes in front (on the aborad side) of the bolus. At the same time, the longitudinal…

  1. Cellular mechanism underlying the facilitation of contractile response of vas deferens smooth muscle by sodium orthovanadate.

    PubMed

    Zhao, Lei; Wang, Zhe; Ruan, Ye-Chun; Zhou, Wen-Liang

    2012-07-01

    In the earlier study, sodium orthovanadate (SOV) has been reported to be a powerful inhibitor of (Na(+), K(+)) adenosine triphosphatase, exhibit widespread actions on the renal and cardiovascular systems, induces smooth muscle contraction by inhibiting the phosphorylation of the protein tyrosine phosphatases. In the current study, we aimed to investigate the cellular mechanisms by which SOV facilitated contractile response of vas deferens smooth muscle and its potential therapeutic advantage. Exogenous application of ATP and NA-caused contraction was strengthened by pretreatment with SOV. This facilitation was inhibited not by bath with the inhibitor of P2 receptor, PPADS, or the inhibitor of α1 receptor, Prazosin, but by bath with the protein tyrosine kinase inhibitor, Genistein. SOV induced a sustained increase in intracellular Ca(2+) of smooth muscle cells, which was abolished by 100 μM Genistein or Ca(2+)-free solution. The facilitation of SOV could also be inhibited by the selective inhibitors of TRP channel, 2-APB and non-selective cation channel, Gd(3+), Ni(+). The in vivo study showed that peritoneal injection of SOV in dystrophic mice (mdx mice) enhanced the contraction of vas deferens smooth muscle stimulated by electrical field stimulation, ATP, noradrenaline, or KCl. The above results suggest that SOV facilitates the concentration of vas deferens smooth muscle through the tyrosine phosphorylation activated the non-selective cation channels, which has potential use in the therapy for muscle dysfunction. PMID:22476902

  2. Pleomorphic rhabdomyosarcoma showing smooth-muscle and fibrohistiocytic differentiation: a single case report.

    PubMed

    Eyden, Brian

    2010-02-01

    Rhabdomyosarcoma has traditionally been subclassified into alveolar, embryonal, and pleomorphic variants. Less commonly, spindle-cell, neuroendocrine, sclerosing, and lipid-rich or clear-cell subtypes are seen. The author recently encountered a myogenic sarcoma, with all the common markers of rhabdomyosarcoma, but expressing the unusual features of alpha-smooth-muscle actin and abundant rough endoplasmic reticulum (rER). This myogenic sarcoma, therefore, exhibited four lines of differentiation, and is documented here. The patient was a 65-year-old man with an inguinal soft tissue mass. Following surgical excision, the patient was given radiotherapy and was well without disease after 6 years. The tumor was positive for vimentin, desmin, alpha-smooth-muscle actin, alpha-sarcomeric actin, myogenin, MyoD1, and CD68. Cytoplasm was dominated by abundant rER intermingled with lipid droplets and lysosomes. Cell surfaces exhibited microvillous processes and focal adhesions, but no lamina. Subplasmalemmal smooth-muscle-type myofilaments with focal densities and rare sarcomeric filaments were seen. The low level of expression of some markers was interpreted as consistent with a poorly differentiated tumor. Given the four lines of differentiation--striated muscle, smooth muscle, fibroblastic, and histiocytic--a name reflecting its phenotype would be pleomorphic rhabdomyosarcoma showing smooth-muscle and fibrohistiocytic differentiation. PMID:20070153

  3. Cell shape and the presentation of adhesion ligands guide smooth muscle myogenesis.

    PubMed

    Zhang, Douglas; Sun, Michael B; Lee, Junmin; Abdeen, Amr A; Kilian, Kristopher A

    2016-05-01

    The reliable generation of smooth muscle cells is important for a number of tissue engineering applications. Human mesenchymal stem cells (MSCs) are a promising progenitor of smooth muscle, with high expression of smooth muscle markers observed in a fraction of isolated cells, which can be increased by introduction of soluble supplements that direct differentiation. Here we demonstrate a new micropatterning technique, where peptides of different ligand affinity can be microcontact printed onto an inert background, to explore MSC differentiation to smooth muscle through controlled biochemical and biophysical cues alone. Using copper-catalyzed alkyne-azide cycloaddition (CuAAC), we patterned our surfaces with RGD peptide ligands-both a linear peptide with low integrin affinity and a cyclic version with high integrin affinity-for the culture of MSCs in shapes with various aspect ratios. At low aspect ratio, ligand affinity is a prime determinant for smooth muscle differentiation, while at high aspect ratio, ligand affinity has less of an effect. Pathway analysis reveals a role for focal adhesion turnover, Rac1, RhoA/ROCK, and calpain during smooth muscle differentiation of MSCs in response to cell shape and the affinity of the cell adhesion interface. Controlling integrin-ligand affinity at the biomaterials interface is important for mediating adhesion but may also prove useful for directing smooth muscle myogenesis. Peptide patterning enables the systematic investigation of single to multiple peptides derived from any protein, at different densities across a biomaterials surface, which has the potential to direct multiple MSC differentiation outcomes without the need for soluble supplements. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1212-1220, 2016. PMID:26799164

  4. Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology

    PubMed Central

    Kullmann, F. Aura; Daugherty, Stephanie L.; de Groat, William C.; Birder, Lori A.

    2015-01-01

    We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties of the smooth muscle as well as changes induced by pathology. This method provides critical information for understanding bladder function while overcoming major methodological difficulties encountered in in vivo experiments, such as surgical and pharmacological manipulations that affect stability and survival of the preparations, the use of human tissue, and/or the use of expensive chemicals. It also provides a way to investigate the properties of each bladder component (i.e. smooth muscle, mucosa, nerves) in healthy and pathological conditions. The urinary bladder is removed from an anesthetized animal, placed in Krebs solution and cut into strips. Strips are placed into a chamber filled with warm Krebs solution. One end is attached to an isometric tension transducer to measure contraction force, the other end is attached to a fixed rod. Tissue is stimulated by directly adding compounds to the bath or by electric field stimulation electrodes that activate nerves, similar to triggering bladder contractions in vivo. We demonstrate the use of this method to evaluate spontaneous smooth muscle contractility during development and after an experimental spinal cord injury, the nature of neurotransmission (transmitters and receptors involved), factors involved in modulation of smooth muscle activity, the role of individual bladder components, and species and organ differences in response to pharmacological agents. Additionally, it could be used for investigating intracellular pathways involved in contraction and/or relaxation of the smooth muscle, drug structure-activity relationships and evaluation of transmitter release. The in vitro smooth muscle contractility method has been used extensively for over 50 years, and has provided data that significantly contributed to our understanding of bladder function as well as to

  5. Effects of upper airway pressure on abdominal muscle activity in conscious dogs.

    PubMed

    Plowman, L; Lauff, D C; McNamara, F; Berthon-Jones, M; Sullivan, C E

    1991-12-01

    We have examined arousal and abdominal muscle electromyogram (EMGabd) responses to upper airway pressure stimuli during physiological sleep in four dogs with permanent side-hole tracheal stomata. The dogs were trained to sleep with a tightly fitting snout mask, hermetically sealed in place, while breathing through a cuffed endotracheal tube inserted through the tracheostomy. Sleep stage was determined by behavioral and electroencephalographic criteria. EMGabd activity was measured using bipolar fine-wire electrodes inserted into the abdominal muscle layers. Static increases or decreases in upper airway pressure (+/- 6 cmH2O), when applied at the snout mask or larynx (upper trachea), caused an immediate decrease in EMGabd on the first two to three breaths; EMGabd usually returned to control levels within the 1-min test interval. In contrast, oscillatory pressure waves at 30 Hz and +/- 3 cmH2O amplitude (or -2 to -8 cmH2O amplitude) produced an immediate and sustained reduction in IMGabd in all sleep states. Inhibition of EMGabd could be maintained over many minutes when the oscillatory pressure stimulus was pulsed by using a cycle of 0.5 s on and 0.5 s off. Oscillatory upper airway pressures were also found to be powerful arousal-promoting stimuli, producing arousal in 94% of tests in drowsiness and 66% of tests in slowwave sleep. The results demonstrate the presence of breath-by-breath upper airway control of abdominal muscle activity. PMID:1778951

  6. Human smooth muscle VLA-1 integrin: purification, substrate specificity, localization in aorta, and expression during development.

    PubMed

    Belkin, V M; Belkin, A M; Koteliansky, V E

    1990-11-01

    A membrane glycoprotein complex was isolated and purified from human smooth muscle by detergent solubilization and affinity chromatography on collagen-Sepharose. The complex was identified as VLA-1 integrin and consisted of two subunits of 195 and 130 kD in SDS-PAGE. Liposomes containing the VLA-1 integrin adhered to surfaces coated with type I, II, III, and IV collagens, Clq subcomponent of the first component of the complement, and laminin. The liposomes specifically adhered to these proteins in a Ca2+, Mg2(+)-dependent manner, but did not bind to gelatin, fibronectin, and thrombospondin substrates. The expression of VLA-1 integrin in different human tissues and cell types, and during aorta smooth muscle development was studied by SDS-PAGE, and subsequent quantitative immunoblotting was performed with antibodies recognizing alpha 1 and beta 1 subunits of the VLA-1 integrin. A high level of VLA-1 integrin expression was an exceptional feature of smooth muscles. Fibroblasts, endothelial cells, keratinocytes, striated muscles, and platelets contained trace amounts of VLA-1 integrin. In the 10-wk-old human fetal aorta, VLA-1 integrin was found only in smooth muscle cells whereas mesenchymal cells, surrounding aortic smooth muscle cells, were VLA-1 integrin negative. By the 24th wk of gestation, the amount of VLA-1 integrin was significantly reduced in the aortic media (4.3-fold for alpha 1 subunit and 2.5-fold for beta 1 subunit) compared with that in the 10-wk-old aortic smooth muscle cells. After birth, the expression of VLA-1 integrin increased and in the 1.5-yr-old child aorta the VLA-1 integrin level was almost the same as in adult aortic media. Smooth muscle cells from intimal thickening of adult aorta express five times less alpha 1 subunit of VLA integrin that smooth muscle cells from adult aortic media. In primary culture of aortic smooth muscle cells, the content of the VLA-1 integrin was dramatically reduced and subcultured cells did not contain VLA-1

  7. Evidence of hypoxic tolerance in weak upper airway muscle from young mdx mice.

    PubMed

    Burns, David P; O'Halloran, Ken D

    2016-06-01

    Duchenne muscular dystrophy (DMD) is a genetic disease characterised by deficiency in the protein dystrophin. The respiratory system is weakened and patients suffer from sleep disordered breathing and hypoventilation culminating in periods of hypoxaemia. We examined the effects of an acute (6h) hypoxic stress on sternohyoid muscle function (representative pharyngeal dilator). 8 week old male, wild-type (WT; C57BL/10ScSnJ; n=18) and mdx (C57BL/10ScSn-Dmd(mdx)/J; n=16) mice were exposed to sustained hypoxia (FIO2=0.10) or normoxia. Muscle functional properties were examined ex vivo. Additional WT (n=5) and mdx (n=5) sternohyoid muscle was exposed to an anoxic challenge. Sternohyoid dysfunction was observed in mdx mice with significant reductions in force and power. Following exposure to the acute in vivo hypoxic stress, WT sternohyoid muscle showed evidence of functional impairment (reduced force, work and power). Conversely, mdx sternohyoid showed an apparent tolerance to the acute hypoxic stress. This tolerance was not maintained for mdx following a severe hypoxic stress. A dysfunctional upper airway muscle phenotype is present at 8 weeks of age in the mdx mouse, which may have implications for the control of airway patency in DMD. Hypoxic tolerance in mdx respiratory muscle is suggestive of adaptation to chronic hypoxia, which could be present due to respiratory morbidity. We speculate a role for hypoxia in mdx respiratory muscle morbidity. PMID:26691169

  8. Acute response of airway muscle to extreme temperature includes disruption of actin-myosin interaction.

    PubMed

    Dyrda, Peter; Tazzeo, Tracy; DoHarris, Lindsay; Nilius, Berndt; Roman, Horia Nicolae; Lauzon, Anne-Marie; Aziz, Tariq; Lukic, Dusan; Janssen, Luke J

    2011-02-01

    Despite the emerging use of bronchial thermoplasty in asthma therapy, the response of airway smooth muscle (ASM) to extreme temperatures is unknown. We investigated the immediate effects of exposing ASM to supraphysiologic temperatures. Isometric contractions were studied in bovine ASM before and after exposure to various thermal loads and/or pharmacologic interventions. Actin-myosin interactions were investigated using a standard in vitro motility assay. We found steep thermal sensitivity for isometric contractions evoked by acetylcholine, with threshold and complete inhibition at less than 50°C and greater than 55°C, respectively. Contractile responses to serotonin or KCl were similarly affected, whereas isometric relaxations evoked by the nitric oxide donor S-nitrosyl-N-acetylpenicillamine or the β-agonist isoproterenol were unaffected. This thermal sensitivity developed within 15 minutes, but did not evolve further over the course of several days (such a rapid time-course rules out heat shock proteins, apoptosis, autophagy, and necrosis). Although heat-sensitive transient receptor potential (TRPV2) channels and the calmodulin-dependent (Cam) kinase-II-induced inactivation of myosin light chain kinase are both acutely thermally sensitive, with a temperature producing half-maximal effect (T(1/2)) of 52.5°C, the phenomenon we describe was not prevented by blockers of TRPV2 channels (e.g., ruthenium red, gadolinium, zero-Ca(2+) or zero-Na(+)/zero-Ca(2+) media, and cromakalim) or of Cam kinase-II (e.g., W7, trifluoperazine, and KN-93). However, direct measurements of actin-myosin interactions showed the same steep thermal profile. The functional changes preceded any histologic evidence of necrosis or apoptosis. We conclude that extreme temperatures (such as those used in bronchial thermoplasty) directly disrupt actin-myosin interactions, likely through a denaturation of the motor protein, leading to an immediate loss of ASM cell function. PMID:20395634

  9. Has cervical smooth muscle any physiological role in the human?

    PubMed

    Bryman, I; Norström, A; Lindblom, B

    1985-01-01

    Strips of human cervical tissue were obtained by needle biopsy and contractile activity was registered isometrically in a tissue chamber perfused by Krebs-Ringer bicarbonate buffer. The most frequently encountered pattern of contractile activity was high frequency-short duration. Prostaglandin (PG)E2, PGI2 and 6-keto-PGF1 alpha had an inhibitory effect on the muscular activity. Cervical muscle from pregnant women was more sensitive to PGE2 than specimens from non-pregnant women. PGF2 alpha had no apparent effect on cervical contractility in non-pregnant and early pregnant patients. In late pregnancy, however, PGF2 alpha inhibited muscle contractions. The present results point to a physiological role of the cervical muscles for the control of cervical competence during pregnancy. The inhibitory effect of PGs on the muscle activity may promote cervical dilatation and retraction. PMID:3893038

  10. Neostigmine but not sugammadex impairs upper airway dilator muscle activity and breathing

    PubMed Central

    Eikermann, M.; Zaremba, S.; Malhotra, A.; Jordan, A. S.; Rosow, C.; Chamberlin, N. L.

    2008-01-01

    Background Cholinesterase inhibitor-based reversal agents, given in the absence of neuromuscular block, evoke a partial upper airway obstruction by decreasing skeletal upper airway muscle function. Sugammadex reverses neuromuscular block by encapsulating rocuronium. However, its effects on upper airway integrity and breathing are unknown. Methods Fifty-one adult male rats were anaesthetized with isoflurane, tracheostomized, and a femoral artery and vein were cannulated. First, we compared the efficacy of sugammadex 15 mg kg−1 and neostigmine 0.06 mg kg−1 to reverse respiratory effects of rocuronium-induced partial paralysis [train-of-four ratio (T4/T1)=0.5]. Subsequently, we compared the safety of sugammadex and neostigmine given after recovery of the T4/T1 to 1, by measuring phasic genioglossus activity and breathing. Results During partial paralysis (T4/T1=0.5), time to recovery of minute volume to baseline values was 10.9 (2), 75.8 (18), and 153 (54) s with sugammadex, neostigmine, and placebo, respectively (sugammadex was significantly faster than neostigmine and placebo, P<0.05). Recovery of T4/T1 was also faster for sugammadex than neostigmine and placebo. Neostigmine administration after complete recovery of T4/T1 decreased upper airway dilator muscle activity to 64 (30)% of baseline and decreased tidal volume (P<0.05 for both variables), whereas sugammadex had no effect on either variable. Conclusions In contrast to neostigmine, which significantly impairs upper airway dilator muscle activity when given after recovery from neuromuscular block, a reversal dose of sugammadex given under the same conditions does not affect genioglossus muscle activity and normal breathing. Human studies will be required to evaluate the clinical relevance of our findings. PMID:18559352

  11. Membrane currents that govern smooth muscle contraction in a ctenophore.

    PubMed

    Bilbaut, A; Hernandez-Nicaise, M L; Leech, C A; Meech, R W

    1988-02-11

    Ctenophores are transparent marine organisms that swim by means of beating cilia; they are the simplest animals with individual muscle fibres. Predatory species, such as Beroe ovata, have particularly well-developed muscles and are capable of an elaborate feeding response. When Beroe contacts its prey, the mouth opens, the body shortens, the pharynx expands, the prey is engulfed and the lips then close tightly. How this sequence, which lasts 1 s, is accomplished is unclear. The muscles concerned are structurally uniform and are innervated at each end by a neuronal nerve net with no centre for coordination. Isolated muscle cells studied under voltage-clamp provide a solution to this puzzle. We find that different groups of muscle cells have different time-dependent membrane currents. Because muscle contraction depends upon calcium entry during each action potential, these different currents produce different patterns of contraction. We conclude that in a simple animal such as a ctenophore, a sophisticated set of membrane conductances can compensate for the absence of an elaborate system of effectors. PMID:2448648

  12. Mechanisms of relaxant activity of the nitric oxide-independent soluble guanylyl cyclase stimulator BAY 41-2272 in rat tracheal smooth muscle.

    PubMed

    Toque, Haroldo A; Mónica, Fabíola Z T; Morganti, Rafael P; De Nucci, Gilberto; Antunes, Edson

    2010-10-25

    The soluble guanylyl cyclase is expressed in airway smooth muscle, and agents that stimulate this enzyme activity cause airway smooth muscle relaxation and bronchodilation. The compound 5-Cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine (BAY 41-2272) is a potent nitric oxide (NO)-independent soluble guanylyl cyclase stimulator, but little is known about its effects in airway smooth muscle. Therefore, this study aimed to investigate the mechanisms underlying the relaxations of rat tracheal smooth muscle induced by BAY 41-2272. Tracheal rings were mounted in 10-ml organ baths for isometric force recording. BAY 41-2272 concentration-dependently relaxed carbachol-precontracted tracheal rings (pEC(50)=6.68+/-0.14). Prior incubation with the NO synthesis inhibitor l-NAME (100 microM) or the soluble guanylyl cyclase inhibitor ODQ (10 microM) caused significant rightward shifts in the concentration-response curves to BAY 41-2272. Sodium nitroprusside caused concentration-dependent relaxations, which were greatly potentiated by BAY 41-2272 and completely inhibited by ODQ. In addition, BAY 41-2272 shifted to the right the tracheal contractile responses to either carbachol (0.01-1 microM) or electrical field stimulation (EFS, 1-32 Hz). BAY 41-2272 (1 microM) also caused a marked rightward shift and decreased the maximal contractile responses to extracellular CaCl2, and such effect was not modified by pretreatment with ODQ. In addition, BAY 41-2272 (up to 1 microM) significantly increased the cGMP levels, and that was abolished by ODQ. Our results indicate that BAY 41-2272 causes cGMP-dependent rat tracheal smooth muscle relaxations in a synergistic fashion with exogenous NO. BAY 41-2272 has also an additional mechanism independently of soluble guanylyl cyclase activation possibly involving Ca(2+) entry blockade. PMID:20670622

  13. Basic fibroblast growth factor: its role in the control of smooth muscle cell migration.

    PubMed Central

    Jackson, C. L.; Reidy, M. A.

    1993-01-01

    The formation of an intimal lesion in an injured artery is the consequence of the replication and migration of smooth muscle cells. Recent studies have implicated basic fibroblast growth factor (bFGF) as an important mediator of replication in the arterial media, and platelet-derived growth factor as an important mediator of migration. However, the degree of arterial trauma produced during injury has a significant influence on the time of onset of intimal thickening, suggesting that factors released from damaged smooth muscle cells may affect migration. We have investigated the role of one of these factors, bFGF, in smooth muscle cell migration in vivo. We found that 1) deendothelialization of the rat carotid artery results in significantly more migration when it is accompanied by traumatic injury to the underlying smooth muscle; 2) the rate of migration in arteries that have been gently deendothelialized is significantly stimulated by systemic injection of bFGF; and 3) inhibition of bFGF with a blocking antibody significantly reduces the amount of migration after traumatic deendothelializing injury with a balloon catheter. These findings suggest that bFGF plays an important role in the mediation of smooth muscle cell migration after arterial injury. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8213998

  14. Phenotypic and Functional Changes of Endothelial and Smooth Muscle Cells in Thoracic Aortic Aneurysms

    PubMed Central

    Malashicheva, Anna; Kostina, Daria; Kostina, Aleksandra; Irtyuga, Olga; Voronkina, Irina; Smagina, Larisa; Ignatieva, Elena; Gavriliuk, Natalia; Uspensky, Vladimir; Moiseeva, Olga; Vaage, Jarle; Kostareva, Anna

    2016-01-01

    Thoracic aortic aneurysm develops as a result of complex series of events that alter the cellular structure and the composition of the extracellular matrix of the aortic wall. The purpose of the present work was to study the cellular functions of endothelial and smooth muscle cells from the patients with aneurysms of the thoracic aorta. We studied endothelial and smooth muscle cells from aneurysms in patients with bicuspid aortic valve and with tricuspid aortic valve. The expression of key markers of endothelial (CD31, vWF, and VE-cadherin) and smooth muscle (SMA, SM22α, calponin, and vimentin) cells as well extracellular matrix and MMP activity was studied as well as and apoptosis and cell proliferation. Expression of functional markers of endothelial and smooth muscle cells was reduced in patient cells. Cellular proliferation, migration, and synthesis of extracellular matrix proteins are attenuated in the cells of the patients. We show for the first time that aortic endothelial cell phenotype is changed in the thoracic aortic aneurysms compared to normal aortic wall. In conclusion both endothelial and smooth muscle cells from aneurysms of the ascending aorta have downregulated specific cellular markers and altered functional properties, such as growth rate, apoptosis induction, and extracellular matrix synthesis. PMID:26904289

  15. Estradiol attenuates directed migration of vascular smooth muscle cells in vitro.

    PubMed Central

    Kolodgie, F. D.; Jacob, A.; Wilson, P. S.; Carlson, G. C.; Farb, A.; Verma, A.; Virmani, R.

    1996-01-01

    Although the cardiovascular benefits of the hormone estrogen are at least, in part, mediated by its antiproliferative effect on vascular smooth muscle, its action on the migration of these cells is unknown. To explore this relationship, female rat aortic smooth muscle cells were grown in hormone-free medium, and the effect of various concentrations of beta-estradiol on directed cellular migration was measured in vitro using a microwell Boyden chamber apparatus. Migration of smooth muscle cells to the known chemoattractants platelet-derived growth factor, insulin-like growth factor-1, and fibronectin (all at peak doses for migratory activity) was attenuated by beta-estradiol (0.5 to 10 ng/ml) in a concentration-dependent manner relative to control cells treated with vehicle (0.01% ethanol). This response was insensitive to pretreatment with indomethacin and was stereospecific (17 alpha-estradiol lacked response). Like beta-estradiol, the synthetic estrogen diethylstilbestrol attenuated directed smooth muscle cell migration whereas the male hormone testosterone was ineffective. Additional studies showed that beta-estradiol-mediated suppression of migration was inhibited by the anti-estrogen ICI 164,384 and the gene transcription inhibitor actinomycin D. These are the first results demonstrating a reduction in directed smooth muscle cell migration by beta-estradiol. The mechanism of this estrogen-mediated response appears to involve conventional estrogen receptors. PMID:8774151

  16. Captopril augments acetylcholine-induced bronchial smooth muscle contractions in vitro via kinin-dependent mechanisms.

    PubMed

    Agrawal, Naman; Akella, Aparna; Deshpande, Shripad B

    2016-06-01

    Angiotensin converting enzyme (ACE) inhibitors therapy is aassociated with bothersome dry cough as an adverse effect. The mechanisms underlying this adverse effect are not clear. Therefore, influence of captopril (an ACE inhibitor) on acetylcholine (ACh)-induced bronchial smooth muscle contractions was investigated. Further, the mechanisms underlying the captopril-induced changes were also explored. In vitro contractions of rat bronchial smooth muscle to cumulative concentrations of ACh were recorded before and after exposure to captopril. Further, the involvement of kinin and inositol triphosphate (IP₃) pathways for captopril-induced alterations were explored. ACh produced concentration-dependent (5-500 µM) increase in bronchial smooth muscle contractions. Pre-treatment with captopril augmented the ACh-induced contractions at each concentration significantly. Pre-treatment with aprotinin (kinin synthesis inhibitor) or heparin (inositol triphosphate, IP₃-inhibitor), blocked the captopril-induced augmentation of bronchial smooth muscle contractions evoked by ACh. Further, captopril-induced augmentation was absent in calcium-free medium. These results suggest that captopril sensitizes bronchial smooth muscles to ACh-induced contractions. This sensitization may be responsible for dry cough associated with captopril therapy. PMID:27468462

  17. Inhibition of the Ca sup 2+ -ATPase of vascular smooth muscle sarcoplasmic reticulum by superoxide radicals

    SciTech Connect

    Suzuki, Yuichiro; Ford, G.D. )

    1991-03-15

    The effect of oxygen free radicals generated by hypoxanthine plus xanthine oxidase on the Ca{sup 2+}-ATPase of sarcoplasmic reticulum from bovine aortic smooth muscle were studied. Exogenous hypoxanthine plus xanthine oxidase produced an hypoxanthine concentration dependent inhibition of the Ca{sup 2+}-ATPase. The inhibition could be completely blocked by superoxide dismutase but not by either mannitol or deferoxamine. Direct addition of reagent hydrogen peroxide in the {mu}M range did not cause significant inhibition. These results suggest that superoxide is the primary damaging species. Additionally, 1.16 {plus minus} 0.17 mU/g wet wt of xanthine oxidase activity were detected in the post-nuclear supernatant of bovine aortic smooth muscle, suggesting the existence of a possible intracellular source of superoxide. This value was calculated to be approximately 5 mU/ml by using a usual value of vascular smooth muscle cellular volume. Thus the level of endogenous xanthine oxidase resident in vascular smooth muscle is comparable with the level of exogenous xanthine oxidase used in the present study. These findings suggest a potential role of xanthine oxidase-generated superoxide in free radical injury to vascular smooth muscle.

  18. Influences on vascular wall smooth muscle cells with novel short-duration thermal angioplasty

    NASA Astrophysics Data System (ADS)

    Kunio, M.; Shimazaki, N.; Arai, T.; Sakurada, M.

    2012-02-01

    We investigated the influences on smooth muscle cells after our novel short-duration thermal angioplasty, Photo-thermo Dynamic Balloon Angioplasty (PTDBA), to reveal the mechanism that can suppress neo-intimal hyperplasia after PTDBA. We obtained the sufficient arterial dilatations by short-duration heating (<=15 s, <70°C) and low dilatation pressure (<0.4 MPa) without arterial injuries in our previous in vivo studies. Smooth muscle cells, which play most important role in chronic treatment effects, were heated during PTDBA and stretch-fixed after PTDBA. The dead cell rate by heating, estimated by Arrhenius equation with A=2.5x1016 s-1 and Ea=1.17×105 J mol-1, was 15.7+/-2.2% after PTDBA. The measured deformation rate of smooth muscle cells' nuclei was 1.6+/-0.1 after PTDBA in vivo. We found that the expression of smooth muscle cells' growth factor after PTDBA was inhibited 0.52 fold compared to that after the conventional balloon angioplasty in vivo. The measured neo-intimal hyperplasia occupancy rate was less than 20% after PTDBA in vivo. We prospect that the inhibition of the growth factor's expression by stretch-fixing may result to suppress the neo-intimal hyperplasia. In addition, the decrease of smooth muscle cells' density in the vessel media by heating might be another reason for the neo-intimal hyperplasia suppression.

  19. Urinary Bladder Smooth Muscle Engineered from Adipose Stem Cells and a Three Dimensional Synthetic Composite

    PubMed Central

    Jack, Gregory S.; Zhang, Rong; Lee, Min; Xu, Yuhan; Wu, Ben; Rodríguez, Larissa V.

    2009-01-01

    Human adipose stem cells were cultured in smooth muscle inductive media and seeded into synthetic bladder composites to tissue engineer bladder smooth muscle. 85:15 poly-lactic-glycolic acid bladder dome composites were cast using an electropulled microfiber luminal surface combined with an outer porous sponge. Cell seeded bladders expressed smooth muscle actin, myosin heavy chain, calponinin, and caldesmon via RT-PCR and immunoflourescence. Nude rats (n=45) underwent removal of half their bladder and repair using: (i) augmentation with the adipose stem cell seeded composites, (ii) augmentation with a matched acellular composite, or (iii) suture closure. Animals were followed for 12 weeks post-implantation and bladders were explanted serially. Results showed that bladder capacity and compliance were maintained in the cell seeded group throughout the 12 weeks, but deteriorated in the acellular scaffold group sequentially with time. Control animals repaired with sutures regained their baseline bladder capacities by week 12, demonstrating a long term limitation of this model. Histological analysis of explanted materials demonstrated viable adipose stem cells and increasing smooth muscle mass in the cell seeded scaffolds with time. Tissue bath stimulation demonstrated smooth muscle contraction of the seeded implants but not the acellular implants after 12 weeks in vivo. Our study demonstrates the feasibility and short term physical properties of bladder tissue engineered from adipose stem cells. PMID:19345408

  20. 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

  1. 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

  2. Phenotypic and Functional Changes of Endothelial and Smooth Muscle Cells in Thoracic Aortic Aneurysms.

    PubMed

    Malashicheva, Anna; Kostina, Daria; Kostina, Aleksandra; Irtyuga, Olga; Voronkina, Irina; Smagina, Larisa; Ignatieva, Elena; Gavriliuk, Natalia; Uspensky, Vladimir; Moiseeva, Olga; Vaage, Jarle; Kostareva, Anna

    2016-01-01

    Thoracic aortic aneurysm develops as a result of complex series of events that alter the cellular structure and the composition of the extracellular matrix of the aortic wall. The purpose of the present work was to study the cellular functions of endothelial and smooth muscle cells from the patients with aneurysms of the thoracic aorta. We studied endothelial and smooth muscle cells from aneurysms in patients with bicuspid aortic valve and with tricuspid aortic valve. The expression of key markers of endothelial (CD31, vWF, and VE-cadherin) and smooth muscle (SMA, SM22α, calponin, and vimentin) cells as well extracellular matrix and MMP activity was studied as well as and apoptosis and cell proliferation. Expression of functional markers of endothelial and smooth muscle cells was reduced in patient cells. Cellular proliferation, migration, and synthesis of extracellular matrix proteins are attenuated in the cells of the patients. We show for the first time that aortic endothelial cell phenotype is changed in the thoracic aortic aneurysms compared to normal aortic wall. In conclusion both endothelial and smooth muscle cells from aneurysms of the ascending aorta have downregulated specific cellular markers and altered functional properties, such as growth rate, apoptosis induction, and extracellular matrix synthesis. PMID:26904289

  3. Proliferation modulates intestinal smooth muscle phenotype in vitro and in colitis in vivo.

    PubMed

    Nair, Dileep G; Han, T Y; Lourenssen, S; Blennerhassett, Michael G

    2011-05-01

    Intestinal inflammation causes an increased intestinal wall thickness, in part, due to the proliferation of smooth muscle cells, which impairs the contractile phenotype elsewhere. To study this, cells from the circular muscle layer of the rat colon (CSMC) were isolated and studied, both in primary culture and after extended passage, using quantitative PCR, Western blot analysis, and immunocytochemistry. By 4 days in vitro, both mRNA and protein for the smooth muscle marker proteins α-smooth muscle actin, desmin, and SM22-α were reduced by >50%, and mRNA for cyclin D1 was increased threefold, evidence for modulation to a proliferative phenotype. Continued growth caused significant further decrease in expression, evidence that phenotypic loss in CSMC was proportional to the extent of proliferation. In CSMC isolated at day 2 of trinitrobenzene sulfonic acid-induced colitis, flow cytometry and Western blotting showed that these differentiated markers were reduced in mitotic CSMC, while similar to control in nonmitotic CSMC. By day 35 post-trinitrobenzene sulfonic acid, when inflammation has resolved, CSMC were hypertrophic, but, nonetheless, showed markedly decreased expression of smooth muscle protein markers per cell. In vitro, day 35 CSMC displayed an accelerated loss of phenotype and increased thymidine uptake in response to serum or PDGF-BB. Furthermore, carbachol-induced expression of phospho-AKT (a marker of cholinergic response) was lost from day 35 CSMC in vitro, while retained in control cells. Therefore, proliferation reduces the expression of smooth-muscle-specific markers in CSMC, possibly leading to altered contractility. However, inflammation-induced proliferation in vivo also causes lasting changes that include unexpected priming for an exaggerated response to proliferative stimuli. Identification of the molecular mechanisms of intestinal smooth muscle cell phenotypic modulation will be helpful in reducing the detrimental effects of inflammation. PMID

  4. Isolation and characterization of the inositol trisphosphate receptor from smooth muscle

    SciTech Connect

    Chadwick, C.C.; Saito, A.; Fleischer, S. )

    1990-03-01

    The release of Ca{sup 2+} from internal stores is requisite to muscle contraction. In skeletal muscle and heart, the Ca{sup 2+} release channels (ryanodine receptor) of sarcoplasmic reticulum, involved in excitation-contraction coupling, have recently been isolated and characterized. In smooth muscle, inositol 1,4,5-trisphosphate (IP{sub 3}) is believed to mobilize Ca{sup 2+} from internal stores and thereby modulate contraction. The authors describe the isolation of an IP{sub 3} receptor from smooth muscle. Bovine aorta smooth muscle microsomes were solubilized with 3-((3-cholamidopropyl) dimethylammonio)-1-propanesulfonate, and the IP{sub 3} receptor was purified by sucrose gradient centrifugation and column chromatography with heparin-agarose and wheat germ agglutinin-agarose. The receptor is an oligomer of a single polypeptide with a M{sub r} of 224,000 as determined by SDS/PAGE. Negative-staining electron microscopy reveals that the receptor is a large pinwheel-like structure having surface dimensions of {approx}250 {times} 250 {angstrom} with fourfold symmetry. The IP{sub 3} receptor from smooth muscle is similar to the ryanodine receptor with regard to its large size and fourfold symmetry, albeit distinct with regard to appearance, protomer size, and ligand binding.

  5. Mechanical properties of the rabbit iris smooth muscles.

    PubMed

    Yamaji, Kazutsuna; Yoshitomi, Takeshi; Usui, Shiro; Ohnishi, Yoshitaka

    2003-02-01

    The study focuses on obtaining the visco-elastic properties of the iris sphincter and dilator muscles. Two kinds of experiments were performed: the isometric contraction experiment and the isotonic quick release experiment. The length-tension relationship was obtained from the former experiment. This relationship clarified the contribution of each muscle in determining the statics of the pupil. The viscous and serial elastic properties were obtained from the latter experiment. The viscosity could be expressed by the expanded Hill's equation as a function of velocity and contractile tension. We argue that serial elasticity is independent of contractile tension. These properties provide insights into the pupillary mechanism. PMID:12536003

  6. Ranolazine inhibits voltage-gated mechanosensitive sodium channels in human colon circular smooth muscle cells.

    PubMed

    Neshatian, Leila; Strege, Peter R; Rhee, Poong-Lyul; Kraichely, Robert E; Mazzone, Amelia; Bernard, Cheryl E; Cima, Robert R; Larson, David W; Dozois, Eric J; Kline, Crystal F; Mohler, Peter J; Beyder, Arthur; Farrugia, Gianrico

    2015-09-15

    Human jejunum smooth muscle cells (SMCs) and interstitial cells of Cajal (ICCs) express the SCN5A-encoded voltage-gated, mechanosensitive sodium channel NaV1.5. NaV1.5 contributes to small bowel excitability, and NaV1.5 inhibitor ranolazine produces constipation by an unknown mechanism. We aimed to determine the presence and molecular identity of Na(+) current in the human colon smooth muscle and to examine the effects of ranolazine on Na(+) current, mechanosensitivity, and smooth muscle contractility. Inward currents were recorded by whole cell voltage clamp from freshly dissociated human colon SMCs at rest and with shear stress. SCN5A mRNA and NaV1.5 protein were examined by RT-PCR and Western blots, respectively. Ascending human colon strip contractility was examined in a muscle bath preparation. SCN5A mRNA and NaV1.5 protein were identified in human colon circular muscle. Freshly dissociated human colon SMCs had Na(+) currents (-1.36 ± 0.36 pA/pF), shear stress increased Na(+) peaks by 17.8 ± 1.8% and accelerated the time to peak activation by 0.7 ± 0.3 ms. Ranolazine (50 μM) blocked peak Na(+) current by 43.2 ± 9.3% and inhibited shear sensitivity by 25.2 ± 3.2%. In human ascending colon strips, ranolazine decreased resting tension (31%), reduced the frequency of spontaneous events (68%), and decreased the response to smooth muscle electrical field stimulation (61%). In conclusion, SCN5A-encoded NaV1.5 is found in human colonic circular smooth muscle. Ranolazine blocks both peak amplitude and mechanosensitivity of Na(+) current in human colon SMCs and decreases contractility of human colon muscle strips. Our data provide a likely mechanistic explanation for constipation induced by ranolazine. PMID:26185330

  7. Stretch activates myosin light chain kinase in arterial smooth muscle

    SciTech Connect

    Barany, K.; Rokolya, A.; Barany, M. )

    1990-11-30

    Stretching of porcine carotid arterial muscle increased the phosphorylation of the 20 kDa myosin light chain from 0.23 to 0.68 mol (32P)phosphate/mol light chain, whereas stretching of phorbol dibutyrate treated muscle increased the phosphorylation from 0.30 to 0.91 mol/mol. Two-dimensional gel electrophoresis followed by two-dimensional tryptic phosphopeptide mapping was used to identify the enzyme involved in the stretch-induced phosphorylation. Quantitation of the (32P)phosphate content of the peptides revealed considerable light chain phosphorylation by protein kinase C only in the phorbol dibutyrate treated arterial muscle, whereas most of the light chain phosphorylation was attributable to myosin light chain kinase. Upon stretch of either the untreated or treated muscle, the total increment in (32P)phosphate incorporation into the light chain could be accounted for by peptides characteristic for myosin light chain kinase catalyzed phosphorylation, demonstrating that the stretch-induced phosphorylation is caused by this enzyme exclusively.

  8. Hypoxia Exerts Dualistic Effects on Inflammatory and Proliferative Responses of Healthy and Asthmatic Primary Human Bronchial Smooth Muscle Cells

    PubMed Central

    Keglowich, Laura; Baraket, Melissa; Tamm, Michael; Borger, Peter

    2014-01-01

    Background For oxygen supply, airway wall cells depend on diffusion though the basement membrane, as well as on delivery by micro-vessels. In the asthmatic lung, local hypoxic conditions may occur due to increased thickness and altered composition of the basement membrane, as well as due to edema of the inflamed airway wall. Objective In our study we investigated the effect of hypoxia on proliferation and pro-inflammatory and pro-angiogenic parameter production by human bronchial smooth muscle cells (BSMC). Furthermore, conditioned media of hypoxia-exposed BSMC was tested for its ability to induce sprout outgrowth from endothelial cells spheroids. Methods BSMC were cultured in RPMI1640 (5% FCS) under normoxic (21% O2) and hypoxic (1% and 5% O2) conditions. Proliferation was determined by cell count and Western blot analysis for cyclin E and Proliferating Cell Nuclear Antigen (PCNA). Secretion of IL-6, IL-8, ENA-78 and VEGF-A was analyzed by ELISA. BSMC conditioned medium was tested for its angiogenic capacity by endothelial cell (EC)-spheroid in vitro angiogenesis assay. Results Proliferation of BSMC obtained from asthmatic and non-asthmatic patients was significantly reduced in the presence of 1% O2, whereas 5% O2 reduced proliferation of asthmatic BSMC only. Hypoxia induced HIF-1α expression in asthmatic and non-asthmatic BSMC, which coincided with significantly increased release of IL-6, IL-8 and VEGF-A, but not ENA-78. Finally, endothelial sprout outgrowth from EC spheroids was increased when exposed to hypoxia conditioned BSMC medium. Conclusion Hypoxia had dualistic effects on proliferative and inflammatory responses of asthmatic and non-asthmatic BSMC. First, hypoxia reduced BSMC proliferation. Second, hypoxia induced a pro-inflammatory, pro-angiogenic response. BSMC and EC may thus be promising new targets to counteract and/or alleviate airway wall remodeling. PMID:24587090

  9. Role of Telokin in Regulating Murine Gastric Fundus Smooth Muscle Tension

    PubMed Central

    An, Changlong; Bhetwal, Bhupal P.; Sanders, Kenton M.; Somlyo, Avril V.; Perrino, Brian A.

    2015-01-01

    Telokin phosphorylation by cyclic GMP-dependent protein kinase facilitates smooth muscle relaxation. In this study we examined the relaxation of gastric fundus smooth muscles from basal tone, or pre-contracted with KCl or carbachol (CCh), and the phosphorylation of telokin S13, myosin light chain (MLC) S19, MYPT1 T853, T696, and CPI-17 T38 in response to 8-Bromo-cGMP, the NO donor sodium nitroprusside (SNP), or nitrergic neurotransmission. We compared MLC phosphorylation and the contraction and relaxation responses of gastric fundus smooth muscles from telokin-/- mice and their wild-type littermates to KCl or CCh, and 8-Bromo-cGMP, SNP, or nitrergic neurotransmission, respectively. We compared the relaxation responses and telokin phosphorylation of gastric fundus smooth muscles from wild-type mice and W/WV mice which lack ICC-IM, to 8-Bromo-cGMP, SNP, or nitrergic neurotransmission. We found that telokin S13 is basally phosphorylated and that 8-Bromo-cGMP and SNP increased basal telokin phosphorylation. In muscles pre-contracted with KCl or CCh, 8-Bromo-cGMP and SNP had no effect on CPI-17 or MYPT1 phosphorylation, but increased telokin phosphorylation and reduced MLC phosphorylation. In telokin-/- gastric fundus smooth muscles, basal tone and constitutive MLC S19 phosphorylation were increased. Pre-contracted telokin-/- gastric fundus smooth muscles have increased contractile responses to KCl, CCh, or cholinergic neurotransmission and reduced relaxation to 8-Bromo-cGMP, SNP, and nitrergic neurotransmission. However, basal telokin phosphorylation was not increased when muscles were stimulated with lower concentrations of SNP or when the muscles were stimulated by nitrergic neurotransmission. SNP, but not nitrergic neurotransmission, increased telokin Ser13 phosphorylation in both wild-type and W/WV gastric fundus smooth muscles. Our findings indicate that telokin may play a role in attenuating constitutive MLC phosphorylation and provide an additional mechanism to

  10. Cannabinoid CB{sub 1} receptor inhibition decreases vascular smooth muscle migration and proliferation

    SciTech Connect

    Rajesh, Mohanraj; Mukhopadhyay, Partha; Hasko, Gyoergy; Pacher, Pal

    2008-12-26

    Vascular smooth muscle proliferation and migration triggered by inflammatory stimuli and chemoattractants such as platelet-derived growth factor (PDGF) are key events in the development and progression of atherosclerosis and restenosis. Cannabinoids may modulate cell proliferation and migration in various cell types through cannabinoid receptors. Here we investigated the effects of CB{sub 1} receptor antagonist rimonabant (SR141716A), which has recently been shown to have anti-atherosclerotic effects both in mice and humans, on PDGF-induced proliferation, migration, and signal transduction of human coronary artery smooth muscle cells (HCASMCs). PDGF induced Ras and ERK 1/2 activation, while increasing proliferation and migration of HCASMCs, which were dose dependently attenuated by CB{sub 1} antagonist, rimonabant. These findings suggest that in addition to improving plasma lipid alterations and decreasing inflammatory cell migration and inflammatory response, CB{sub 1} antagonists may exert beneficial effects in atherosclerosis and restenosis by decreasing vascular smooth muscle proliferation and migration.

  11. Smooth muscle relaxant activity of Crocus sativus (saffron) and its constituents: possible mechanisms.

    PubMed

    Mokhtari-Zaer, Amin; Khazdair, Mohammad Reza; Boskabady, Mohammad Hossein

    2015-01-01

    Saffron, Crocus sativus L. (C. sativus) is rich in carotenoids and used in traditional medicine for treatment of various conditions such as coughs, stomach disorders, amenorrhea, asthma and cardiovascular disorders. These therapeutic effects of the plant are suggested to be due to its relaxant effect on smooth muscles. The effect of C. sativus and its constituents on different smooth muscles and the underlying mechanisms have been studied. Several studies have shown the relaxant effects of C. sativus and its constituents including safranal, crocin, crocetin and kaempferol on blood vessels. In addition, it was reported that saffron stigma lowers systolic blood pressure. The present review highlights the relaxant effects of C. sativus and its constituents on various smooth muscles. The possible mechanisms of this relaxing effect including activation of ß2-adrenoceptors, inhibition of histamine H1 and muscarinic receptors and calcium channels and modulation of nitric oxide (NO) are also reviewed. PMID:26468456

  12. Smooth muscle relaxant activity of Crocus sativus (saffron) and its constituents: possible mechanisms

    PubMed Central

    Mokhtari-Zaer, Amin; Khazdair, Mohammad Reza; Boskabady, Mohammad Hossein

    2015-01-01

    Saffron, Crocus sativus L. (C. sativus) is rich in carotenoids and used in traditional medicine for treatment of various conditions such as coughs, stomach disorders, amenorrhea, asthma and cardiovascular disorders. These therapeutic effects of the plant are suggested to be due to its relaxant effect on smooth muscles. The effect of C. sativus and its constituents on different smooth muscles and the underlying mechanisms have been studied. Several studies have shown the relaxant effects of C. sativus and its constituents including safranal, crocin, crocetin and kaempferol on blood vessels. In addition, it was reported that saffron stigma lowers systolic blood pressure. The present review highlights the relaxant effects of C. sativus and its constituents on various smooth muscles. The possible mechanisms of this relaxing effect including activation of ß2-adrenoceptors, inhibition of histamine H1 and muscarinic receptors and calcium channels and modulation of nitric oxide (NO) are also reviewed. PMID:26468456

  13. The role of mechanotransduction on vascular smooth muscle myocytes cytoskeleton and contractile function

    PubMed Central

    Ye, George J.C.; Nesmith, Alexander P.; Parker, Kevin Kit

    2016-01-01

    Smooth muscle exhibits a highly organized structural hierarchy that extends over multiple spatial scales to perform a wide range of functions at the cellular, tissue, and organ levels. Early efforts primarily focused on understanding vascular smooth muscle function through biochemical signaling. However, accumulating evidence suggests that mechanotransduction, the process through which cells convert mechanical stimuli into biochemical cues, is requisite for regulating contractility. Cytoskeletal proteins that comprise the extracellular, intercellular, and intracellular domains are mechanosensitive and can remodel their structure and function in response to external mechanical cues. Pathological stimuli such as malignant hypertension can act through the same mechanotransductive pathways to induce maladaptive remodeling, leading to changes in cellular shape and loss of contractile function. In both health and disease, the cytoskeletal architecture integrates the mechanical stimuli and mediates structural and functional remodeling in the vascular smooth muscle. PMID:25125187

  14. Development of the smooth muscle foam cell: uptake of macrophage lipid inclusions.

    PubMed

    Wolfbauer, G; Glick, J M; Minor, L K; Rothblat, G H

    1986-10-01

    A possible mechanism for the formation of smooth muscle foam cells in the atherosclerotic lesion was explored. Cultured macrophages (J774 cell line) were induced to form cytoplasmic cholesteryl ester inclusions by exposure to acetylated low density lipoprotein in the presence of cholesterol-rich phospholipid dispersions. The macrophages were disrupted by brief sonication, and the inclusions were isolated by flotation. When these inclusions were placed in direct contact with cultured smooth muscle cells, cellular uptake of the inclusions in a time- and dose-dependent manner was observed. Light and electron microscopy indicated the presence of lipid inclusions throughout the cytoplasm of the cells. Uptake of inclusion lipid by the smooth muscle cells was inhibited by several metabolic inhibitors, indicating that the process is dependent on metabolic activity. A modest but significant hydrolysis of the cholesteryl ester was observed, showing that the stored cholesteryl esters are metabolically available. PMID:3020555

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

    SciTech Connect

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

    1991-03-01

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

  16. Augmented Vascular Smooth Muscle Cell Stiffness and Adhesion when Hypertension is Superimposed on Aging

    PubMed Central

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

    2014-01-01

    Hypertension and aging are both recognized to increase aortic stiffness, but their interactions are not completely understood. Most prior studies have attributed increased aortic stiffness to changes in extracellular matrix proteins that alter mechanical properties of the vascular wall. Alternatively, we hypothesized that a significant component of increased vascular stiffness in hypertension is due to changes in the mechanical and adhesive properties of vascular smooth muscle cells, and that aging would augment the contribution from vascular smooth muscle cells compared to the extracellular matrix. Accordingly, we studied aortic stiffness in young (16 wks) and old (64 wks) spontaneously hypertensive rats and Wistar-Kyoto wild-type controls. Systolic and pulse pressures were significantly increased in young spontaneously hypertensive rats, compared to young Wistar-Kyoto rats, and these continued to rise in old spontaneously hypertensive rats, compared to age-matched controls. Excised aortic ring segments exhibited significantly greater elastic moduli in both young and old spontaneously hypertensive rats vs. Wistar-Kyoto rats. Vascular smooth muscle cells were isolated from the thoracic aorta, and stiffness and adhesion to fibronectin were measured by atomic force microscopy. Hypertension increased both vascular smooth muscle cell stiffness and vascular smooth muscle cell adhesion, and these increases were both augmented with aging. By contrast, hypertension did not affect histological measures of aortic collagen and elastin, which were predominantly changed by aging. This supports the concept that stiffness and adhesive properties of vascular smooth muscle cells are novel mechanisms contributing to the increased aortic stiffness occurring with hypertension superimposed on aging. PMID:25452471

  17. In vitro differentiation of porcine aortic vascular precursor cells to endothelial and vascular smooth muscle cells.

    PubMed

    Zaniboni, Andrea; Bernardini, Chiara; Bertocchi, Martina; Zannoni, Augusta; Bianchi, Francesca; Avallone, Giancarlo; Mangano, Chiara; Sarli, Giuseppe; Calzà, Laura; Bacci, Maria Laura; Forni, Monica

    2015-09-01

    Recent findings suggest that progenitor and multipotent mesenchymal stromal cells (MSCs) are associated with vascular niches. Cells displaying mesenchymal properties and differentiating to whole components of a functional blood vessel, including endothelial and smooth muscle cells, can be defined as vascular stem cells (VSCs). Recently, we isolated a population of porcine aortic vascular precursor cells (pAVPCs), which have MSC- and pericyte-like properties. The aim of the present work was to investigate whether pAVPCs possess VSC-like properties and assess their differentiation potential toward endothelial and smooth muscle lineages. pAVPCs, maintained in a specific pericyte growth medium, were cultured in high-glucose DMEM + 10% FBS (long-term medium, LTM) or in human endothelial serum-free medium + 5% FBS and 50 ng/ml of hVEGF (endothelial differentiation medium, EDM). After 21 days of culture in LTM, pAVPCs showed an elongated fibroblast-like morphology, and they seem to organize in cord-like structures. qPCR analysis of smooth muscle markers [α-smooth muscle actin (α-SMA), calponin, and smooth muscle myosin (SMM) heavy chain] showed a significant increment of the transcripts, and immunofluorescence analysis confirmed the presence of α-SMA and SMM proteins. After 21 days of culture in EDM, pAVPCs displayed an endothelial cell-like morphology and revealed the upregulation of the expression of endothelial markers (CD31, vascular endothelial-cadherin, von Willebrand factor, and endothelial nitric oxide synthase) showing the CD31-typical pattern. In conclusion, pAVPCs could be defined as a VSC-like population considering that, if they are maintained in a specific pericyte medium, they express MSC markers, and they have, in addition to the classical mesenchymal trilineage differentiation potential, the capacity to differentiate in vitro toward the smooth muscle and the endothelial cell phenotypes. PMID:26135800

  18. A Novel Selectable Islet 1 Positive Progenitor Cell Reprogrammed to Expandable and Functional Smooth Muscle Cells.

    PubMed

    Turner, Elizabeth C; Huang, Chien-Ling; Sawhney, Neha; Govindarajan, Kalaimathi; Clover, Anthony J P; Martin, Kenneth; Browne, Tara C; Whelan, Derek; Kumar, Arun H S; Mackrill, John J; Wang, Shaohua; Schmeckpeper, Jeffrey; Stocca, Alessia; Pierce, William G; Leblond, Anne-Laure; Cai, Liquan; O'Sullivan, Donnchadh M; Buneker, Chirlei K; Choi, Janet; MacSharry, John; Ikeda, Yasuhiro; Russell, Stephen J; Caplice, Noel M

    2016-05-01

    Disorders affecting smooth muscle structure/function may require technologies that can generate large scale, differentiated and contractile smooth muscle cells (SMC) suitable for cell therapy. To date no clonal precursor population that provides large numbers of differentiated SMC in culture has been identified in a rodent. Identification of such cells may also enhance insight into progenitor cell fate decisions and the relationship between smooth muscle precursors and disease states that implicate differentiated SMC.  In this study, we used classic clonal expansion techniques to identify novel self-renewing Islet 1 (Isl-1) positive primitive progenitor cells (PPC) within rat bone marrow that exhibited canonical stem cell markers and preferential differentiation towards a smooth muscle-like fate. We subsequently used molecular tagging to select Isl-1 positive clonal populations from expanded and de novo marrow cell populations. We refer to these previously undescribed cells as the PPC given its stem cell marker profile, and robust self-renewal capacity. PPC could be directly converted into induced smooth muscle cells (iSMC) using single transcription factor (Kruppel-like factor 4) knockdown or transactivator (myocardin) overexpression in contrast to three control cells (HEK 293, endothelial cells and mesenchymal stem cells) where such induction was not possible. iSMC exhibited immuno- and cytoskeletal-phenotype, calcium signaling profile and contractile responses similar to bona fide SMC. Passaged iSMC could be expanded to a scale sufficient for large scale tissue replacement.  PPC and reprogramed iSMC so derived may offer future opportunities to investigate molecular, structure/function and cell-based replacement therapy approaches to diverse cardiovascular, respiratory, gastrointestinal, and genitourinary diseases that have as their basis smooth muscle cell functional aberrancy or numerical loss. Stem Cells 2016;34:1354-1368. PMID:26840832

  19. Myosin light chain phosphorylation in contraction of gastric antral smooth muscle from neonate and adult rabbits.

    PubMed

    Ierardi, J A; Paul, D A; Ryan, J P

    1996-01-01

    The decreased contractility of gastric antral smooth muscle in the neonate has been attributed to reduced levels of activator calcium. It is generally accepted that calcium-dependent myosin light chain phosphorylation (MLCP) is the key step in the initiation of force development in smooth muscle. In this study, we investigated the relationship between MLCP and force development in gastric antral smooth muscle from neonatal (4-6 d old) and adult rabbits. We tested the hypothesis that the reduced force development of circular smooth muscle from the neonate would be accompanied by decreased levels of MLCP, as compared with data from adult animals. Full thickness muscle strips oriented parallel to the circular muscle layer were examined for their contractile response to acetylcholine (ACh) (10(-8) M to 10(-3) M) or 10(-4) M ACh only. In the latter study, tissues were rapidly frozen in a dry ice-acetone slurry for subsequent MLCP determination. MLCP was determined at times corresponding to 5, 10, 15, 30, and 60 s of stimulation. For each age group, maximal active force developed at an ACh concentration of 10(-4) M and was significantly greater in tissues from adults (1.86 +/- 0.24 N/m2, adult; 0.95 +/- 0.05 N/m2, neonate; p < 0.05). In contrast, no significant differences were observed with respect to basal or agonist-stimulated levels of MLCP. The data suggest that factors other than levels of MLCP contribute to the reduced force-generating capacity of antral smooth muscle from the neonate. PMID:8825402

  20. Induced Pluripotent Stem Cell-derived Vascular Smooth Muscle Cells: Methods and Application

    PubMed Central

    Dash, Biraja C.; Jiang, Zhengxin; Suh, Carol; Qyang, Yibing

    2015-01-01

    Vascular smooth muscle cells (VSMCs) play a major role in the pathophysiology of cardiovascular diseases. The advent of induced pluripotent stem cell (iPSC) technology and their capability to differentiation into virtually every cell type in the human body make this field a ray of hope for vascular regenerative therapy and for understanding disease mechanism. In this review, we first discuss the recent iPSC technology and vascular smooth muscle development from embryo and then examine different methodology to derive VSMCs from iPSCs and their applications in regenerative therapy and disease modeling. PMID:25559088

  1. Thrombospondin-1 limits ischemic tissue survival by inhibiting nitric oxide–mediated vascular smooth muscle relaxation

    PubMed Central

    Isenberg, Jeff S.; Hyodo, Fuminori; Matsumoto, Ken-Ichiro; Romeo, Martin J.; Abu-Asab, Mones; Tsokos, Maria; Kuppusamy, Periannan; Wink, David A.; Krishna, Murali C.

    2007-01-01

    The nitric oxide (NO)/cGMP pathway, by relaxing vascular smooth muscle cells, is a major physiologic regulator of tissue perfusion. We now identify thrombospondin-1 as a potent antagonist of NO for regulating F-actin assembly and myosin light chain phosphorylation in vascular smooth muscle cells. Thrombospondin-1 prevents NO-mediated relaxation of precontracted vascular smooth muscle cells in a collagen matrix. Functional magnetic resonance imaging demonstrated that an NO-mediated increase in skeletal muscle perfusion was enhanced in thrombospondin-1–null relative to wild-type mice, implicating endogenous thrombospondin-1 as a physiologic antagonist of NO-mediated vasodilation. Using a random myocutaneous flap model for ischemic injury, tissue survival was significantly enhanced in thrombospondin-1–null mice. Improved flap survival correlated with increased recovery of oxygen levels in the ischemic tissue of thrombospondin-1–null mice as measured by electron paramagnetic resonance oximetry. These findings demonstrate an important antag-onistic relation between NO/cGMP signaling and thrombospondin-1 in vascular smooth muscle cells to regulate vascular tone and tissue perfusion. PMID:17082319

  2. Crystal Structure of a Phosphorylated Light Chain Domain of Scallop Smooth-Muscle Myosin

    SciTech Connect

    Kumar, V.S.; Robinson, H.; O-Neall-Hennessey, E.; Reshetnikova, L.; Brown, J. H.; Szent-Gyorgyi, A. G.; Cohen, C.

    2011-11-02

    We have determined the crystal structure of a phosphorylated smooth-muscle myosin light chain domain (LCD). This reconstituted LCD is of a sea scallop catch muscle myosin with its phosphorylatable regulatory light chain (RLC SmoA). In the crystal structure, Arg{sup 16}, an arginine residue that is present in this isoform but not in vertebrate smooth-muscle RLC, stabilizes the phosphorylation site. This arginine interacts with the carbonyl group of the phosphorylation-site serine in the unphosphorylated LCD (determined previously), and with the phosphate group when the serine is phosphorylated. However, the overall conformation of the LCD is essentially unchanged upon phosphorylation. This result provides additional evidence that phosphorylation of the RLC is unlikely to act as an on-switch in regulation of scallop catch muscle myosin.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  5. Embracing change: striated-for-smooth muscle replacement in esophagus development.

    PubMed

    Krauss, Robert S; Chihara, Daisuke; Romer, Anthony I

    2016-01-01

    The esophagus functions to transport food from the oropharyngeal region to the stomach via waves of peristalsis and transient relaxation of the lower esophageal sphincter. The gastrointestinal tract, including the esophagus, is ensheathed by the muscularis externa (ME). However, while the ME of the gastrointestinal tract distal to the esophagus is exclusively smooth muscle, the esophageal ME of many vertebrate species comprises a variable amount of striated muscle. The esophageal ME is initially composed only of smooth muscle, but its developmental maturation involves proximal-to-distal replacement of smooth muscle with striated muscle. This fascinating phenomenon raises two important questions: what is the developmental origin of the striated muscle precursor cells, and what are the cellular and morphogenetic mechanisms underlying the process? Studies addressing these questions have provided controversial answers. In this review, we discuss the development of ideas in this area and recent work that has shed light on these issues. A working model has emerged that should permit deeper understanding of the role of ME development and maturation in esophageal disorders and in the functional and evolutionary underpinnings of the variable degree of esophageal striated myogenesis in vertebrate species. PMID:27504178

  6. Differential Expression of Lipid and Carbohydrate Metabolism Genes in Upper Airway versus Diaphragm Muscle

    PubMed Central

    van Lunteren, Erik; Spiegler, Sarah; Moyer, Michelle

    2010-01-01

    Study Objectives: Contractile properties of upper airway muscles influence upper airway patency, an issue of particular importance for subjects with obstructive sleep apnea. Expression of genes related to cellular energetics is, in turn, critical for the maintenance of contractile integrity over time during repetitive activation. We tested the hypothesis that sternohyoid has lower expression of genes related to lipid and carbohydrate energetic pathways than the diaphragm. Methods: Sternohyoid and diaphragm from normal adult rats were examined with gene expression arrays. Analysis focused on genes belonging to Gene Ontology (GO) groups carbohydrate metabolism and lipid metabolism. Results: There were 433 genes with at least ± 2-fold significant differential expression between sternohyoid and diaphragm, of which 192 had sternohyoid > diaphragm and 241 had diaphragm > sternohyoid expression. Among genes with higher sternohyoid expression, there was over-representation of the GO group carbohydrate metabolism (P = 0.0053, n = 13 genes, range of differential expression 2.1- to 6.2-fold) but not lipid metabolism (P = 0.44). Conversely, among genes with higher diaphragm expression, there was over-representation of the GO group lipid metabolism (P = 0.0000065, n = 32 genes, range of differential expression 2.0- to 37.9-fold) but not carbohydrate metabolism (P = 0.23). Nineteen genes with diaphragm > sternohyoid expression were related to fatty acid metabolism (P = 0.000000058), in particular fatty acid β oxidation and biosynthesis in the mitochondria. Conclusions: Sternohyoid has much lower gene expression than diaphragm for mitochondrial enzymes that participate in fatty acid oxidation and biosynthesis. This likely contributes to the lower fatigue resistance of pharyngeal upper airway muscles compared with the diaphragm. Citation: van Lunteren E; Spiegler S; Moyer M. Differential expression of lipid and carbohydrate metabolism genes in upper airway versus diaphragm

  7. Simulations demonstrate a simple network to be sufficient to control branch point selection, smooth muscle and vasculature formation during lung branching morphogenesis.

    PubMed

    Cellière, Géraldine; Menshykau, Denis; Iber, Dagmar

    2012-08-15

    Proper lung functioning requires not only a correct structure of the conducting airway tree, but also the simultaneous development of smooth muscles and vasculature. Lung branching morphogenesis is strongly stereotyped and involves the recursive use of only three modes of branching. We have previously shown that the experimentally described interactions between Fibroblast growth factor (FGF)10, Sonic hedgehog (SHH) and Patched (Ptc) can give rise to a Turing mechanism that not only reproduces the experimentally observed wildtype branching pattern but also, in part counterintuitive, patterns in mutant mice. Here we show that, even though many proteins affect smooth muscle formation and the expression of Vegfa, an inducer of blood vessel formation, it is sufficient to add FGF9 to the FGF10/SHH/Ptc module to successfully predict simultaneously the emergence of smooth muscles in the clefts between growing lung buds, and Vegfa expression in the distal sub-epithelial mesenchyme. Our model reproduces the phenotype of both wildtype and relevant mutant mice, as well as the results of most culture conditions described in the literature. PMID:23213471

  8. Simulations demonstrate a simple network to be sufficient to control branch point selection, smooth muscle and vasculature formation during lung branching morphogenesis

    PubMed Central

    Cellière, Géraldine; Menshykau, Denis; Iber, Dagmar

    2012-01-01

    Summary Proper lung functioning requires not only a correct structure of the conducting airway tree, but also the simultaneous development of smooth muscles and vasculature. Lung branching morphogenesis is strongly stereotyped and involves the recursive use of only three modes of branching. We have previously shown that the experimentally described interactions between Fibroblast growth factor (FGF)10, Sonic hedgehog (SHH) and Patched (Ptc) can give rise to a Turing mechanism that not only reproduces the experimentally observed wildtype branching pattern but also, in part counterintuitive, patterns in mutant mice. Here we show that, even though many proteins affect smooth muscle formation and the expression of Vegfa, an inducer of blood vessel formation, it is sufficient to add FGF9 to the FGF10/SHH/Ptc module to successfully predict simultaneously the emergence of smooth muscles in the clefts between growing lung buds, and Vegfa expression in the distal sub-epithelial mesenchyme. Our model reproduces the phenotype of both wildtype and relevant mutant mice, as well as the results of most culture conditions described in the literature. PMID:23213471

  9. Nitric Oxide-mediated Relaxation by High K in Human Gastric Longitudinal Smooth Muscle.

    PubMed

    Kim, Young Chul; Choi, Woong; Yun, Hyo-Young; Sung, Rohyun; Yoo, Ra Young; Park, Seon-Mee; Yun, Sei Jin; Kim, Mi-Jung; Song, Young-Jin; Xu, Wen-Xie; Lee, Sang Jin

    2011-12-01

    This study was designed to elucidate high-K(+)induced response of circular and longitudinal smooth muscle from human gastric corpus using isometric contraction. Contraction from circular and longitudinal muscle stripes of gastric corpus greater curvature and lesser curvature were compared. Circular smooth muscle from corpus greater curvature showed high K(+) (50 mM)-induced tonic contraction. On the contrary, however, longitudinal smooth muscle strips showed high K(+) (50 mM)-induced sustained relaxation. To find out the reason for the discrepancy we tested several relaxation mechanisms. Protein kinase blockers like KT5720, PKA inhibitor, and KT5823, PKG inhibitor, did not affect high K(+)-induced relaxation. K(+) channel blockers like tetraethylammonium (TEA), apamin (APA), glibenclamide (Glib) and barium (Ba(2+)) also had no effect. However, N(G)-nitro-L-arginine (L-NNA) and 1H-(1,2,4) oxadiazolo (4,3-A) quinoxalin-1-one (ODQ), an inhibitor of soluble guanylate cyclase (sGC) and 4-AP (4-aminopyridine), voltage-dependent K(+) channel (K(V)) blocker, inhibited high K(+)-induced relaxation, hence reversing to tonic contraction. High K(+)-induced relaxation was observed in gastric corpus of human stomach, but only in the longitudinal muscles from greater curvature not lesser curvature. L-NNA, ODQ and K(V) channel blocker sensitive high K(+)-induced relaxation in longitudinal muscle of higher portion of corpus was also observed. These results suggest that longitudinal smooth muscle from greater curvature of gastric corpus produced high K(+)-induced relaxation which was activated by NO/sGC pathway and by K(V) channel dependent mechanism. PMID:22359479

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

    SciTech Connect

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

    2009-04-01

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

  11. Cytotoxicity of some oxysterols on human vascular smooth muscle cells was mediated by apoptosis.

    PubMed

    Miyashita, Y; Shirai, K; Ito, Y; Watanabe, J; Urano, Y; Murano, T; Tomioka, H

    1997-01-01

    A decrease in smooth muscle cells is observed in advanced atherosclerotic lesion. To understand this mechanism, we selected oxysterols as candidates for toxic lipid, and examined their cytotoxicity on human cultured vascular smooth muscle cells, together with the manner of cell death. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol (50 mumol/L), the percentage of detached cells increased significantly with dose dependency, and an increase in detached cell number and DNA nick detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling study (TUNEL) preceded an increase in lactate dehydrogenase released into the medium. DNA extracted from smooth muscle cells incubated with 7-ketocholesterol or 7 beta-hydroxycholesterol showed a laddering pattern on agarose electrophoresis. In the presence of 7-ketocholesterol or 7 beta-hydroxycholesterol, fragmented DNA quantified by the quantitative sandwich enzyme immunoassay was significantly increased. From these results, it is proposed that 7-ketocholesterol and 7 beta-hydroxycholesterol are toxic to smooth muscle cells, and that this cytotoxicity is mediated by apoptosis. PMID:9638517

  12. ACTIVATION OF GATA-4 BY SEROTONIN IN PULMONARY ARTERY SMOOTH MUSCLE CELLS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serotonin (5-HT) is a mitogen of pulmonary artery smooth muscle cells (PASMC) and plays an important role in the development of pulmonary hypertension. Signal transduction initiated by 5-HT involves serotonin transporter (SERT)-dependent generation of reactive oxygen species (ROS) and activation of...

  13. Intercellular ultrafast Ca2+ wave in vascular smooth muscle cells: numerical and experimental study

    PubMed Central

    Quijano, J. C.; Raynaud, F.; Nguyen, D.; Piacentini, N.; Meister, J. J.

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca2+ waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca2+ wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca2+ wave and it was suggested to be the result of the interplay between membrane potential and Ca2+ dynamics which depended on influx of extracellular Ca2+, cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca2+ wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca2+ wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca2+ wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca2+ waves in smooth muscle cells. PMID:27507785

  14. Effects of sumatriptan nasal spray (Imigran) on isolated rat's tracheal smooth muscle.

    PubMed

    Cheng, Li-Hsiang; Wu, Pei-Chuan; Liu, Shao-Cheng; Chiu, Feng-Shiang; Chu, Yueng-Hsiang; Chang, Ying-Nan; Wang, Hsing-Won

    2015-10-01

    Sumatriptan (Imigran) is a potent and highly selective 5-HT1 receptor agonist often used in treating acute migraine. Intranasal sumatriptan is well absorbed and is generally effective in relieving headache. However, the effects of Imigran given intratracheally have rarely been well explored. We aimed to verify the effect of Imigran, which acts on the tracheal smooth muscle directly in vitro. We examined the effectiveness of Imigran on isolated rat tracheal smooth muscle by testing: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10(-6) M methacholine as a parasympathetic mimetic; (3) effect of the drugs on electrically induced tracheal smooth muscle contractions. The results indicated that the addition of methacholine to the incubation medium caused the trachea to contract in a dose-dependent manner. The addition of Imigran at doses of 10(-5) M or above elicited a significant relaxation response to 10(-6) M methacholine-induced contraction. Imigran could inhibit electrical field stimulation-induced spike contraction. It also had a minimal effect on the basal tension of trachea as the concentration increased. The study indicated high concentrations of Imigran could cause bronchodilation to reduce asthma attacks not only by blocking parasympathetic tone, but also by directly antagonizing the effect of cholinergic receptors. PMID:25394582

  15. Anti-cholinergic effect of singulair on isolated rat's tracheal smooth muscle.

    PubMed

    Cheng, Li-Hsiang; Kao, Chuan-Hsiang; Wang, Chih-Hung; Chu, Yueng-Hsiang; Wang, Jia-Yi; Wang, Hsing-Won

    2012-08-01

    Singulair (Montelukast) is a potent and selective leukotriene D(4) receptor antagonist, often used in treating inflammatory conditions of the respiratory system such as allergic rhinitis and asthma. However, the effects of singulair given intratracheally have rarely been well explored. To verify the effect of singulair, which acts on the tracheal smooth muscle directly in vitro. We used our preparation to test the effects of singulair on isolated rat's tracheal smooth muscle. The following assessments of singulair were performed: (1) effect on the tracheal smooth muscle resting tension, (2) effect on contraction caused by 10(-6) M methacholine as a parasympathetic mimetic, and (3) effect of the drugs on electrically induced tracheal smooth muscle contractions. The results indicated that the addition of methacholine to the incubation medium caused the trachea to contract in a dose-dependent manner. Addition of singulair at doses of 10(-5) M or above elicited a significant relaxation response to 10(-6) M methacholine-induced contraction. Singulair could not inhibit electrical field stimulation-induced spike contraction. It also had a minimal effect on the basal tension of trachea as the concentration increased. This study showed that the high concentrations of singulair also had an anti-cholinergic effect for relieving symptoms of asthma. PMID:22203119

  16. Circumferential alignment of vascular smooth muscle cells in a circular microfluidic channel.

    PubMed

    Choi, Jong Seob; Piao, Yunxian; Seo, Tae Seok

    2014-01-01

    The circumferential alignment of human aortic smooth muscle cells (HASMCs) in an orthogonally micropatterned circular microfluidic channel is reported to form an in vivo-like smooth muscle cell layer. To construct a biomimetic smooth muscle cell layer which is aligned perpendicular to the axis of blood vessel, a half-circular polydimethylsiloxane (PDMS) microchannel is first fabricated by soft lithography using a convex PDMS mold. Then, the orthogonally microwrinkle patterns are generated inside the half-circular microchannel by a strain responsive wrinkling method. During the UV treatment on a PDMS substrate with uniaxial 40% stretch and a subsequent strain releasing step, the microwrinkle patterns perpendicular to the axial direction of the circular microchannel are generated, which can guide the circumferential alignment of HASMCs during cultivation. The analysis of orientation angle, shape index, and contractile protein marker expression indicates that the cultured HASMCs reveal the in vivo-like cell phenotype. Finally, a fully circular microchannel is produced by bonding two half-circular microchannels, and the HASMCs are cultured circumferentially inside the channels with high alignment and viability for 5 days. These results demonstrated the creation of an in vivo-like 3D smooth muscle cell layer in the circular microfluidic channel which can provide a bioassay platforms for in-depth study of HASMC biology and vascular function. PMID:24120039

  17. A specific gastrin receptor on plasma membranes of antral smooth muscle.

    PubMed

    Baur, S; Bacon, V C

    1976-12-20

    Plasma membranes with a 17 fold enrichment in 5'-nucleotidase over homogenate were prepared from antral smooth muscle. A specific gastrin receptor on the plasma membranes has been demonstrated. By Scatchard analysis receptor has a Kaff of 2x10(9)M(-1) and a binding capacity of 5x10(-14) moles/mg of membrane protein. PMID:15625862

  18. Epstein-Barr virus-associated smooth muscle tumor of the tonsil.

    PubMed

    Suwansirikul, Songkiet; Sukpan, Kornkanok; Sittitrai, Pichit; Suwiwat, Supaporn; Khunamornpong, Surapan

    2012-06-01

    Smooth muscle tumors of the tonsil are rare. Recently, the occurrence of Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) has been increasingly recognized in immunocompromised patients, mainly post-transplantation and AIDS patients. The clinicopathologic features of EBV-SMT are different from conventional smooth muscle tumors. To the best of our knowledge, EBV-SMT involving the tonsil in an AIDS patient has not been reported. A 27-year-old man presented with a 2.2cm right tonsillar mass six months after AIDS diagnosis. The tumor was composed of a cellular proliferation of oval to spindle-shaped cells with mitotic count up to 10 in 10 high-power fields. The diagnosis of EBV-SMT was confirmed by in situ hybridization for EBV-encoded RNA (EBER) transcripts. Synchronous lesions were also detected in the liver and peritoneum by an abdominal computed tomographic scan. EBV-SMT should be included in the differential diagnoses of a mesenchymal tumor in immunocompromised patients, and in the differential diagnoses of a smooth muscle tumor occurring in uncommon sites including the tonsil. PMID:21885224

  19. Intercellular ultrafast Ca(2+) wave in vascular smooth muscle cells: numerical and experimental study.

    PubMed

    Quijano, J C; Raynaud, F; Nguyen, D; Piacentini, N; Meister, J J

    2016-01-01

    Vascular smooth muscle cells exhibit intercellular Ca(2+) waves in response to local mechanical or KCl stimulation. Recently, a new type of intercellular Ca(2+) wave was observed in vitro in a linear arrangement of smooth muscle cells. The intercellular wave was denominated ultrafast Ca(2+) wave and it was suggested to be the result of the interplay between membrane potential and Ca(2+) dynamics which depended on influx of extracellular Ca(2+), cell membrane depolarization and its intercel- lular propagation. In the present study we measured experimentally the conduction velocity of the membrane depolarization and performed simulations of the ultrafast Ca(2+) wave along coupled smooth muscle cells. Numerical results reproduced a wide spectrum of experimental observations, including Ca(2+) wave velocity, electrotonic membrane depolarization along the network, effects of inhibitors and independence of the Ca(2+) wave speed on the intracellular stores. The numerical data also provided new physiological insights suggesting ranges of crucial model parameters that may be altered experimentally and that could significantly affect wave kinetics allowing the modulation of the wave characteristics experimentally. Numerical and experimental results supported the hypothesis that the propagation of membrane depolarization acts as an intercellular messenger mediating intercellular ultrafast Ca(2+) waves in smooth muscle cells. PMID:27507785

  20. 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

  1. A mechanochemical 3D continuum model for smooth muscle contraction under finite strains.

    PubMed

    Stålhand, J; Klarbring, A; Holzapfel, G A

    2011-01-01

    This paper presents a modelling framework in which the mechanochemical properties of smooth muscle cells may be studied. The activation of smooth muscles is considered in a three-dimensional continuum model which is key to realistically capture the function of hollow organs such as blood vessels. On the basis of a general thermodynamical framework the mechanical and chemical phases are specialized in order to quantify the coupled mechanochemical process. A free-energy function is proposed as the sum of a mechanical energy stored in the passive tissue, a coupling between the mechanical and chemical kinetics and an energy related purely to the chemical kinetics and the calcium ion concentration. For the chemical phase it is shown that the cross-bridge model of Hai and Murphy [1988. Am. J. Physiol. Cell Physiol. 254, C99-C106] is included in the developed evolution law as a special case. In order to show the specific features and the potential of the proposed continuum model a uniaxial extension test of a tissue strip is analysed in detail and the related kinematics and stress-stretch relations are derived. Parameter studies point to coupling phenomena; in particular the tissue response is analysed in terms of the calcium ion level. The model for smooth muscle contraction may significantly contribute to current modelling efforts of smooth muscle tissue responses. PMID:20946904

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

    PubMed

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

    2013-01-01

    Estrogen signaling, through estrogen receptor (ER)α, has been shown to cause hypertrophy in the prostate. Our recent report has shown that epithelial ERα knockout (KO) will not affect the normal prostate development or homeostasis. However, it remains unclear whether ERα in different types of stromal cells has distinct roles in prostate development. This study proposed to elucidate how KO of ERα in the stromal smooth muscle or fibroblast cells may interrupt cross talk between prostate stromal and epithelial cells. Smooth muscle ERαKO (smERαKO) mice showed decreased glandular infolding with the proximal area exhibiting a significant decrease. Fibroblast ERαKO mouse prostates did not exhibit this phenotype but showed a decrease in the number of ductal tips. Additionally, the amount of collagen observed in the basement membrane was reduced in smERαKO prostates. Interestingly, these phenotypes were found to be mutually exclusive among smERαKO or fibroblast ERαKO mice. Compound KO of ERα in both fibroblast and smooth muscle showed combined phenotypes from each of the single KO. Further mechanistic studies showed that IGF-I and epidermal growth factor were down-regulated in prostate smooth muscle PS-1 cells lacking ERα. Together, our results indicate the distinct functions of fibroblast vs. smERα in prostate development. PMID:23204329

  3. Modeling smooth muscle cell proliferation of coronary artery expanded with a drug eluting stent

    NASA Astrophysics Data System (ADS)

    Lyu, Suping

    2010-03-01

    The drug eluting coronary stent is for the treatment of narrowed coronary artery. A high strength balloon is used to open the narrowed vessel and leave behind a tiny metal mesh, or stent, to mechanically prevent the vessel from re-narrowing and biologically slow down proliferation of the smooth muscle cells. However, the drug eluting stents that had better performance also more seriously prevented the healing processes of the vessels, which could cause serious thrombotic reactions. In this study, we assume the healing process is controlled by proper proliferation of smooth cells. We also assume that the inflammation reactions and mechanical traction drive the smooth muscle cells to proliferate while the drug loaded in the stents drives the processes at the opposite direction. Numerical calculation was applied to the system. The drug distribution and elution durations, inflammation reactions and mechanical traction were discussed.

  4. The induction of YAP expression following arterial injury is crucial for smooth muscle phenotypic modulation and neointima formation

    PubMed Central

    Wang, Xiaobo; Hu, Guoqing; Gao, Xiangwei; Wang, Yong; Zhang, Wei; Harmon, Erin Yund; Zhi, Xu; Xu, Zhengping; Lennartz, Michelle R.; Barroso, Margarida; Trebak, Mohamed; Chen, Ceshi; Zhou, Jiliang

    2012-01-01

    Objective Abnormal proliferation and migration of vascular smooth muscle cells (SMCs) are the key events in the progression of neointima formation in response to vascular injury. The goal of this study is to investigate the functional role of a potent oncogene YAP in smooth muscle phenotypic modulation in vitro and in vivo. Methods and Results In vitro in cell culture and in vivo in both mouse and rat arterial injury models YAP expression is significantly induced and correlated with the vascular SMC synthetic phenotype. Over-expression of YAP promotes SMC migration and proliferation while attenuating smooth muscle contractile gene expression. Conversely, knocking-down endogenous YAP in SMCs up-regulates smooth muscle gene expression but attenuates SMC proliferation and migration. Consistent with this, knocking-down YAP expression in a rat carotid balloon injury model and genetic deletion of YAP specifically in vascular SMCs in mouse after carotid artery ligation injury attenuates injury-induced smooth muscle phenotypic switch and neointima formation. Conclusions YAP plays a novel integrative role in smooth muscle phenotypic modulation by inhibiting smooth muscle-specific gene expression while promoting smooth muscle proliferation and migration in vitro and in vivo. Blocking the induction of YAP would be a potential therapeutic approach for ameliorating vascular occlusive diseases. PMID:22922963

  5. Predicted EC50 and EC95 of Remifentanil for Smooth Removal of a Laryngeal Mask Airway Under Propofol Anesthesia

    PubMed Central

    Yoo, Ji Young; Kwak, Hyun Jeong; Lee, Kyung Cheon; Kim, Go Wun

    2015-01-01

    Purpose The purpose of this study was to determine the effect-site concentration (Ce) of remifentanil in 50% of patients (EC50) and 95% of patients (EC95) for smooth laryngeal mask airway (LMA) removal in adults under propofol and remifentanil anesthesia. Materials and Methods Twenty-five patients of ASA physical status I-II and ages 18-60 years who were to undergo minor gynecological or orthopedic surgery were assessed in this study. Anesthesia was induced and maintained with propofol and remifentanil target-controlled infusion (TCI). Remifentanil was maintained at a predetermined Ce during the emergence period. The modified Dixon's up-and-down method was used to determine the remifentanil concentration, starting from 1.0 ng/mL (step size of 0.2 ng/mL). Successful removal of the LMA was regarded as absence of coughing/gagging, clenched teeth, gross purposeful movements, breath holding, laryngospasm, or desaturation to SpO2<90%. Results The mean±SD Ce of remifentanil for smooth LMA removal after propofol anesthesia was 0.83±0.16 ng/mL. Using isotonic regression with a bootstrapping approach, the estimated EC50 and EC95 of remifentanil Ce were 0.91 ng/mL [95% confidence interval (CI), 0.77-1.07 ng/mL] and 1.35 ng/mL (95% CI, 1.16-1.38 ng/mL), respectively. Conclusion Our results showed that remifentanil TCI at an established Ce is a reliable technique for achieving safe and smooth emergence without coughing, laryngospasm, or other airway reflexes. PMID:26069139

  6. AMPK Dilates Resistance Arteries via Activation of SERCA and BKCa Channels in Smooth Muscle.

    PubMed

    Schneider, Holger; Schubert, Kai Michael; Blodow, Stephanie; Kreutz, Claus-Peter; Erdogmus, Serap; Wiedenmann, Margarethe; Qiu, Jiehua; Fey, Theres; Ruth, Peter; Lubomirov, Lubomir T; Pfitzer, Gabriele; Mederos Y Schnitzler, Michael; Hardie, D Grahame; Gudermann, Thomas; Pohl, Ulrich

    2015-07-01

    The protective effects of 5'-AMP-activated protein kinase (AMPK) on the metabolic syndrome may include direct effects on resistance artery vasomotor function. However, the precise actions of AMPK on microvessels and their potential interaction are largely unknown. Thus, we set to determine the effects of AMPK activation on vascular smooth muscle tone and the underlying mechanisms. Resistance arteries isolated from hamster and mouse exhibited a pronounced endothelium-independent dilation on direct pharmacological AMPK activation by 2 structurally unrelated compounds (PT1 and A769662). The dilation was associated with a decrease of intracellular-free calcium [Ca(2+)]i in vascular smooth muscle cell. AMPK stimulation induced activation of BKCa channels as assessed by patch clamp studies in freshly isolated hamster vascular smooth muscle cell and confirmed by direct proof of membrane hyperpolarization in intact arteries. The BKCa channel blocker iberiotoxin abolished the hyperpolarization but only partially reduced the dilation and did not affect the decrease of [Ca(2+)]i. By contrast, the sarcoplasmic/endoplasmic Ca(2+)-ATPase (SERCA) inhibitor thapsigargin largely reduced these effects, whereas combined inhibition of SERCA and BKCa channels virtually abolished them. AMPK stimulation significantly increased the phosphorylation of the SERCA modulator phospholamban at the regulatory T17 site. Stimulation of smooth muscle AMPK represents a new, potent vasodilator mechanism in resistance vessels. AMPK directly relaxes vascular smooth muscle cell by a decrease of [Ca(2+)]i. This is achieved by calcium sequestration via SERCA activation, as well as activation of BKCa channels. There is in part a mutual compensation of both calcium-lowering mechanisms. However, SERCA activation which involves an AMPK-dependent phosphorylation of phospholamban is the predominant mechanism in resistance vessels. PMID:26034200

  7. Collagen degradation and platelet-derived growth factor stimulate the migration of vascular smooth muscle cells.

    PubMed

    Stringa, E; Knäuper, V; Murphy, G; Gavrilovic, J

    2000-06-01

    Cell migration is a key event in many biological processes and depends on signals from both extracellular matrix and soluble motogenic factors. During atherosclerotic plaque development, vascular smooth muscle cells migrate from the tunica media to the intima through a basement membrane and interstitial collagenous matrix and proliferate to form a neointima. Matrix metalloproteinases have previously been implicated in neointimal formation and in this study smooth muscle cell adhesion and migration on degraded collagen have been evaluated. Vascular smooth muscle cells adhered to native intact collagen type I and to its first degradation by-product, 3/4 fragment (generated by collagenase-3 cleavage), unwound at 35 degrees C to mimic physiological conditions. PDGF-BB pre-treatment induced a fourfold stimulation of smooth muscle cell motility on the collagen 3/4 fragment whereas no increase in smooth muscle cell motility on collagen type I was observed. Cell migration on collagen type I was mediated by alpha2 integrin, whereas PDGF-BB-stimulated migration on the 3/4 collagen fragment was dependent on alphavbeta3 integrin. alphavbeta3 integrin was organised in clusters concentrated at the leading and trailing edges of the cells and was only expressed when cells were exposed to the 3/4 collagen fragment. Tyrphostin A9, an inhibitor of PDGF receptor-beta tyrosine kinase activity, resulted in complete abolition of migration of PDGF-BB treated cells on collagen type I and 3/4 fragment. These results strongly support the hypothesis that the cellular migratory response to soluble motogens can be regulated by proteolytic modification of the extracellular matrix. PMID:10806116

  8. Electrical properties of purinergic transmission in smooth muscle of the guinea-pig prostate.

    PubMed

    Lam, Michelle; Mitsui, Retsu; Hashitani, Hikaru

    2016-01-01

    Prostatic smooth muscle develops spontaneous myogenic tone which is modulated by autonomic neuromuscular transmission. This study aimed to investigate the role of purinergic transmission in regulating electrical activity of prostate smooth muscle and whether its contribution may be altered with age. Intracellular recordings were simultaneously made with isometric tension recordings in smooth muscle preparations of the guinea-pig prostate. Immunostaining for P2X1 receptors on whole mount preparations was also performed. In prostate preparations which generated spontaneous slow waves, electrical field stimulation (EFS)-evoked excitatory junction potentials (EJPs) which were abolished by guanethidine (10 μM), α-β-methylene ATP (10 μM) or pyridoxal phosphate-6-azophenyl-2,4-disulfonic acid (PPADS, 10 μM) but not phentolamine (1 μM). Consistently, immunostaining revealed the expression of P2X1 receptors on prostatic smooth muscle. EJPs themselves did not cause contractions, but EJPs could sum to trigger a slow wave and associated contraction. Yohimbine (1 μM) and 3,7-dimethyl-1-propargylxanthine (DMPX, 10 μM) but not propranolol (1 μM) potentiated EJPs. Although properties of EJPs were not different between young and aging guinea-pig prostates, ectoATPase inhibitor ARL 67156 (100 μM) augmented EJP amplitudes by 64.2 ± 29.6% in aging animals, compared to 22.1 ± 19.9% in young animals. These results suggest that ATP released from sympathetic nerves acts on P2X1 purinoceptors located on prostate smooth muscle to evoke EJPs, while pre-junctional α2-adrenergic and adenosine A2 receptors may play a role in preventing excessive transmitter release. Age-related up-regulation of enzymatic ATP breakdown may be a compensatory mechanism for the enhanced purinergic transmission which would cause hypercontractility arising from increased ATP release in older animals. PMID:26657181

  9. A new enzymic method for the isolation and culture of human bladder body smooth muscle cells.

    PubMed

    Ma, F -H; Higashira, H; Ukai, Y; Hanai, T; Kiwamoto, H; Park, Y C; Kurita, T

    2002-01-01

    Cultured cells of the human urinary bladder smooth muscle are useful for investigating bladder function, but methods for culturing them are not well developed. We have now established a novel enzymic technique. The smooth muscle layer was separated out and incubated with 0.2% trypsin for 30 min at 37 degrees C. The samples were then minced and incubated with 0.1% collagenase for 30 min and centrifuged at 900 g. The pellets were resuspended in RPMI-1640 medium containing 10% fetal calf serum (FCS) and centrifuged at 250 g. The smooth muscle cells from the supernatant were cultured in RPMI-1640 containing 10% FCS. The cells grew to confluence after 7-10 days, forming the "hills and valleys" growth pattern characteristic of smooth muscle cells. Immunostaining with anti-alpha-actin, anti-myosin, and anti-caldesmon antibodies demonstrated that 99% of the cells were smooth muscle cells. To investigate the pharmacological properties of the cultured cells, we determined the inhibitory effect of muscarinic receptor antagonists on the binding of [3H]N-methylscopolamine to membranes from cultured cells. The pKi values obtained for six antagonists agreed with the corresponding values for transfected cells expressing the human muscarinic M2 subtype. Furthermore, carbachol produced an increase in the concentration of cytoplasmic free Ca2+ an action that was blocked by 4-diphenylacetoxy-N-methylpiperidine methiodide, an M3 selective antagonist. This result suggests that these cells express functional M3 muscarinic receptors, in addition to M2 receptors. The subcultured cells therefore appear to be unaffected by our new isolation method. PMID:11835427

  10. Rapid effects of phytoestrogens on human colonic smooth muscle are mediated by oestrogen receptor beta.

    PubMed

    Hogan, A M; Collins, D; Sheehan, K; Zierau, O; Baird, A W; Winter, D C

    2010-05-14

    Epidemiological studies have correlated consumption of dietary phytoestrogens with beneficial effects on colon, breast and prostate cancers. Genomic and non-genomic mechanisms are responsible for anti-carcinogenic effects but, until now, the effect on human colon was assumed to be passive and remote. No direct effect on human colonic smooth muscle has previously been described. Institutional research board approval was granted. Histologically normal colon was obtained from the proximal resection margin of colorectal carcinoma specimens. Circular smooth muscle strips were microdissected and suspended under 1g of tension in organ baths containing oxygenated Krebs solution at 37 degrees C. After an equilibration period, tissues were exposed to diarylpropionitrile (DPN) (ER beta agonist) and 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) (ER alpha agonist) or to the synthetic phytoestrogen compounds genistein (n=8), daidzein (n=8), fisetin (n=8) and quercetin (n=8) in the presence or absence of fulvestrant (oestrogen receptor antagonist). Mechanism of action was investigated by inhibition of downstream pathways. The cholinergic agonist carbachol was used to induce contractile activity. Tension was recorded isometrically. Phytoestrogens inhibit carbachol-induced colonic contractility. In keeping with a non-genomic, rapid onset direct action, the effect was within minutes, reversible and similar to previously described actions of 17 beta oestradiol. No effect was seen in the presence of fulvestrant indicating receptor modulation. While the DPN exerted inhibitory effects, PPT did not. The effect appears to be reliant on a p38/mitogen activated protein kinase mediated induction of nitric oxide production in colonic smooth muscle. The present data set provides the first description of a direct effect of genistein, daidzein, fisetin and quercetin on human colonic smooth muscle. The presence of ER in colonic smooth muscle has been functionally proven and the beta

  11. Differentiated muscles are mandatory for gas-filling of the Drosophila airway system

    PubMed Central

    Wang, Yiwen; Cruz, Tina; Irion, Uwe; Moussian, Bernard

    2015-01-01

    ABSTRACT At the end of development, organs acquire functionality, thereby ensuring autonomy of an organism when it separates from its mother or a protective egg. In insects, respiratory competence starts when the tracheal system fills with gas just before hatching of the juvenile animal. Cellular and molecular mechanisms of this process are not fully understood. Analyses of the phenotype of Drosophila embryos with malformed muscles revealed that they fail to gas-fill their tracheal system. Indeed, we show that major regulators of muscle formation like Lame duck and Blown fuse are important, while factors involved in the development of subsets of muscles including cardiac and visceral muscles are dispensable for this process, suggesting that somatic muscles (or parts of them) are essential to enable tracheal terminal differentiation. Based on our phenotypic data, we assume that somatic muscle defect severity correlates with the penetrance of the gas-filling phenotype. This argues that a limiting molecular or mechanical muscle-borne signal tunes tracheal differentiation. We think that in analogy to the function of smooth muscles in vertebrate lungs, a balance of physical forces between muscles and the elasticity of tracheal walls may be decisive for tracheal terminal differentiation in Drosophila. PMID:26621831

  12. A new level of plasticity: Drosophila smooth-like testes muscles compensate failure of myoblast fusion

    PubMed Central

    Kuckwa, Jessica; Fritzen, Katharina; Buttgereit, Detlev; Rothenbusch-Fender, Silke; Renkawitz-Pohl, Renate

    2016-01-01

    The testis of Drosophila resembles an individual testis tubule of mammals. Both are surrounded by a sheath of smooth muscles, which in Drosophila are multinuclear and originate from a pool of myoblasts that are set aside in the embryo and accumulate on the genital disc later in development. These muscle stem cells start to differentiate early during metamorphosis and give rise to all muscles of the inner male reproductive system. Shortly before the genital disc and the developing testes connect, multinuclear nascent myotubes appear on the anterior tips of the seminal vesicles. Here, we show that adhesion molecules are distinctly localized on the seminal vesicles; founder cell (FC)-like myoblasts express Dumbfounded (Duf) and Roughest (Rst), and fusion-competent myoblast (FCM)-like cells mainly express Sticks and stones (Sns). The smooth but multinuclear myotubes of the testes arose by myoblast fusion. RNAi-mediated attenuation of Sns or both Duf and Rst severely reduced the number of nuclei in the testes muscles. Duf and Rst probably act independently in this context. Despite reduced fusion in all of these RNAi-treated animals, myotubes migrated onto the testes, testes were shaped and coiled, muscle filaments were arranged as in the wild type and spermatogenesis proceeded normally. Hence, the testes muscles compensate for fusion defects so that the myofibres encircling the adult testes are indistinguishable from those of the wild type and male fertility is guaranteed. PMID:26657767

  13. Two-pore-domain potassium channels in smooth muscles: new components of myogenic regulation.

    PubMed

    Sanders, Kenton M; Koh, Sang Don

    2006-01-01

    Gastrointestinal (GI) smooth muscles are influenced by many levels of regulation, including those provided by enteric motor neurones, hormones and paracrine substances. The integrated contractile responses to these regulatory mechanisms depend heavily on the state of excitability of smooth muscle cells. Resting ionic conductances and myogenic responses to agonists and physical parameters, such as stretch, are important in establishing basal excitability. This review discusses the role of 2-pore-domain K+ channels in contributing to background conductances and in mediating responses of GI muscles to enteric inhibitory nerve stimulation and stretch. Murine GI muscles express TREK-1 channels and display a stretch-dependent K+ (SDK) conductance that is also activated by nitric oxide via a cGMP-dependent mechanism. Cloning and expression of mTREK-1 produced an SDK conductance that was activated by cGMP-dependent phosphorylation at serine-351. GI muscle cells also express TASK-1 and TASK-2 channels that are inhibited by lidocaine and external acidification. These conductances appear to provide significant background K+ permeability that contributes to the negative resting potentials of GI muscles. PMID:16239268

  14. A new level of plasticity: Drosophila smooth-like testes muscles compensate failure of myoblast fusion.

    PubMed

    Kuckwa, Jessica; Fritzen, Katharina; Buttgereit, Detlev; Rothenbusch-Fender, Silke; Renkawitz-Pohl, Renate

    2016-01-15

    The testis of Drosophila resembles an individual testis tubule of mammals. Both are surrounded by a sheath of smooth muscles, which in Drosophila are multinuclear and originate from a pool of myoblasts that are set aside in the embryo and accumulate on the genital disc later in development. These muscle stem cells start to differentiate early during metamorphosis and give rise to all muscles of the inner male reproductive system. Shortly before the genital disc and the developing testes connect, multinuclear nascent myotubes appear on the anterior tips of the seminal vesicles. Here, we show that adhesion molecules are distinctly localized on the seminal vesicles; founder cell (FC)-like myoblasts express Dumbfounded (Duf) and Roughest (Rst), and fusion-competent myoblast (FCM)-like cells mainly express Sticks and stones (Sns). The smooth but multinuclear myotubes of the testes arose by myoblast fusion. RNAi-mediated attenuation of Sns or both Duf and Rst severely reduced the number of nuclei in the testes muscles. Duf and Rst probably act independently in this context. Despite reduced fusion in all of these RNAi-treated animals, myotubes migrated onto the testes, testes were shaped and coiled, muscle filaments were arranged as in the wild type and spermatogenesis proceeded normally. Hence, the testes muscles compensate for fusion defects so that the myofibres encircling the adult testes are indistinguishable from those of the wild type and male fertility is guaranteed. PMID:26657767

  15. Influence of upper airway sensory receptors on respiratory muscle activation in humans.

    PubMed

    Redline, S; Strohl, K P

    1987-07-01

    We reasoned that neural information from upper airway (UA) sensory receptors could influence the relationship between UA and diaphragmatic neuromuscular responses to hypercapnia. In this study, the electromyographic (EMG) activities of the alae nasi (AN), genioglossus (GG), and chest wall (CW) or diaphragm (Di) to ventilatory loading were assessed in six laryngectomized, tracheostomized human subjects and in six subjects breathing with an intact UA before and after topical UA anesthesia. The EMG activities of the UA and thoracic muscles increased at similar rates with increasing hypercapnia in normal subjects, in subjects whose upper airways were anesthetized, and in laryngectomized subjects breathing with a cervical tracheostomy. Furthermore, in the laryngectomized subjects, respiratory muscle EMG activation increased with resistive inspiratory loading (15 cmH2O X l-1 X s) applied at the level of a cervical tracheostomy. At an average expired CO2 fraction of 7.0%, resistive loading resulted in a 93 +/- 26.3% (SE) increase in peak AN EMG activity, a 39 +/- 2.0% increase in peak GG EMG activity, and a 43.2 +/- 16.5% increase in peak CW (Di) EMG activity compared with control values. We conclude that the ventilatory responses of the UA and thoracic muscles to ventilatory loading are not substantially influenced by laryngectomy or UA anesthesia. PMID:3624139

  16. beta. -adrenergic relaxation of smooth muscle: differences between cells and tissues

    SciTech Connect

    Scheid, C.R.

    1987-09-01

    The present studies were carried out in an attempt to resolve the controversy about the Na/sup +/ dependence of ..beta..-adrenergic relaxation in smooth muscle. Previous studies on isolated smooth muscle cells from the toad stomach had suggested that at least some of the actions of ..beta..-adrenergic agents, including a stimulatory effect on /sup 45/Ca efflux, were dependent on the presence of a normal transmembrane Na/sup +/ gradient. Studies by other investigators using tissues derived from mammalian sources had suggested that the relaxing effect of ..beta..-adrenergic agents was Na/sup +/ independent. Uncertainty remained as to whether these discrepancies reflected differences between cells and tissues or differences between species. Thus, in the present studies, the authors utilized both tissues and cells from the same source, the stomach muscle of the toad Bufo marinus, and assessed the Na/sup +/ dependence of ..beta..-adrenergic relaxation. They found that elimination of a normal Na/sup +/ gradient abolished ..beta..-adrenergic relaxation of isolated cells. In tissues, however, similar manipulations had no effect on relaxation. The reasons for this discrepancy are unclear but do not appear to be attributable to changes in smooth muscle function following enzymatic dispersion. Thus the controversy concerning the mechanisms of ..beta..-adrenergic relaxation may reflect inherent differences between tissues and cells.

  17. Nitric oxide mediates stretch-induced Ca2+ oscillation in smooth muscle.

    PubMed

    Zheng, Ji; Zhai, Kui; Chen, Yingxiao; Zhang, Xu; Miao, Lin; Wei, Bin; Ji, Guangju

    2016-06-15

    The stretching of smooth muscle tissue modulates contraction through augmentation of Ca(2+) transients, but the mechanism underlying stretch-induced Ca(2+) transients is still unknown. We found that mechanical stretching and maintenance of mouse urinary bladder smooth muscle strips and single myocytes at 30% and 18% beyond the initial length, respectively, resulted in Ca(2+) oscillations. Experiments indicated that mechanical stretching remarkably increased the production of nitric oxide (NO) as well as the amplitude and duration of muscle contraction. Stretch-induced Ca(2+) oscillations and contractility increases were completely abolished by the NO inhibitor L-NAME or eNOS (also known as NOS3) gene inactivation. Moreover, exposure of eNOS-knockout myocytes to exogenous NO donor induced Ca(2+) oscillations. The stretch-induced Ca(2+) oscillations were greatly inhibited by the selective inositol 1,4,5-trisphosphate receptor (IP3R) inhibitor xestospongin C and partially inhibited by ryanodine. Moreover, the stretch-induced Ca(2+) oscillations were also suppressed by the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, but not by the soluble guanylyl cyclase (sGC) inhibitor ODQ. These results suggest that stretching myocyte and maintenance at a certain length results in Ca(2+) oscillations that are NO dependent , and sGC and cGMP independent, and results from the activation of PI3K in smooth muscle. PMID:27189081

  18. Combined electric field and gap junctions on propagation of action potentials in cardiac muscle and smooth muscle in PSpice simulation.

    PubMed

    Sperelakis, Nicholas

    2003-10-01

    Propagation of action potentials in cardiac muscle and smooth muscle were simulated using the PSpice program. Excitation was transmitted from cell to cell along a strand of 6 cells (cardiac muscle) or 10 cells (smooth muscle) either not connected (control) or connected by low-resistance tunnels (gap-junction connexons). A significant negative cleft potential (V(jv) ) develops in the narrow junctional cleft when the pre-JM fires. V(jc) depolarizes the postjunctional membrane (post-JM) to threshold by a patch-clamp action. With few connecting tunnels, cell-to-cell transmission by the EF mechanism was facilitated. With many tunnels, propagation was dominated by the low-resistance mechanism, and propagation velocity (theta) became very fast and nonphysiological. In conclusion, when the 2 mechanisms for cell-to-cell transfer of excitation were combined, the two mechanisms facilitated each other in a synergistic manner. When there were many connecting tunnels, the tunnel mechanism was dominant. PMID:14661164

  19. Depolarization-induced contractile activity of smooth muscle in calcium-free solution.

    PubMed

    Mangel, A W; Nelson, D O; Rabovsky, J L; Prosser, C L; Connor, J A

    1982-01-01

    In calcium-free solution, strips of cat intestinal muscle developed slow, rhythmic electrical potential changes that triggered contractions. Some strips failed to develop spontaneous electrical activity in calcium-free solution but responded with contractions to depolarization by direct electrical stimulation or by treatment with barium chloride, potassium chloride, or acetylcholine. Similar results were obtained with segments of cat stomach, colon, esophagus, bladder, uterus, and vena cava, as well as with rabbit vena cava. In calcium-free saline, rat small intestinal muscle showed fast electrical activity with accompanying development of a tetanuslike contraction. After 60 min in calcium-free solution, cat small intestinal muscle retained 17.7% of its original concentration of calcium. It is concluded that in some smooth muscles, depolarization-triggered release of intracellular calcium does not require an associated influx of calcium. PMID:7058877

  20. Smooth muscle myosin light chain kinase efficiently phosphorylates serine 15 of cardiac myosin regulatory light chain

    SciTech Connect

    Josephson, Matthew P.; Sikkink, Laura A.; Penheiter, Alan R.; Burghardt, Thomas P.; Ajtai, Katalin

    2011-12-16

    Highlights: Black-Right-Pointing-Pointer Cardiac myosin regulatory light chain (MYL2) is phosphorylated at S15. Black-Right-Pointing-Pointer Smooth muscle myosin light chain kinase (smMLCK) is a ubiquitous kinase. Black-Right-Pointing-Pointer It is a widely believed that MYL2 is a poor substrate for smMLCK. Black-Right-Pointing-Pointer In fact, smMLCK efficiently and rapidly phosphorylates S15 in MYL2. Black-Right-Pointing-Pointer Phosphorylation kinetics measured by novel fluorescence method without radioactivity. -- Abstract: Specific phosphorylation of the human ventricular cardiac myosin regulatory light chain (MYL2) modifies the protein at S15. This modification affects MYL2 secondary structure and modulates the Ca{sup 2+} sensitivity of contraction in cardiac tissue. Smooth muscle myosin light chain kinase (smMLCK) is a ubiquitous kinase prevalent in uterus and present in other contracting tissues including cardiac muscle. The recombinant 130 kDa (short) smMLCK phosphorylated S15 in MYL2 in vitro. Specific modification of S15 was verified using the direct detection of the phospho group on S15 with mass spectrometry. SmMLCK also specifically phosphorylated myosin regulatory light chain S15 in porcine ventricular myosin and chicken gizzard smooth muscle myosin (S20 in smooth muscle) but failed to phosphorylate the myosin regulatory light chain in rabbit skeletal myosin. Phosphorylation kinetics, measured using a novel fluorescence method eliminating the use of radioactive isotopes, indicates similar Michaelis-Menten V{sub max} and K{sub M} for regulatory light chain S15 phosphorylation rates in MYL2, porcine ventricular myosin, and chicken gizzard myosin. These data demonstrate that smMLCK is a specific and efficient kinase for the in vitro phosphorylation of MYL2, cardiac, and smooth muscle myosin. Whether smMLCK plays a role in cardiac muscle regulation or response to a disease causing stimulus is unclear but it should be considered a potentially significant

  1. Systems-level airway models of bronchoconstriction.

    PubMed

    Donovan, Graham M

    2016-09-01

    Understanding lung and airway behavior presents a number of challenges, both experimental and theoretical, but the potential rewards are great in terms of both potential treatments for disease and interesting biophysical phenomena. This presents an opportunity for modeling to contribute to greater understanding, and here, we focus on modeling efforts that work toward understanding the behavior of airways in vivo, with an emphasis on asthma. We look particularly at those models that address not just isolated airways but many of the important ways in which airways are coupled both with each other and with other structures. This includes both interesting phenomena involving the airways and the layer of airway smooth muscle that surrounds them, and also the emergence of spatial ventilation patterns via dynamic airway interaction. WIREs Syst Biol Med 2016, 8:459-467. doi: 10.1002/wsbm.1349 For further resources related to this article, please visit the WIREs website. PMID:27348217

  2. Smooth Muscle-Targeted Overexpression of Peroxisome Proliferator Activated Receptor-γ Disrupts Vascular Wall Structure and Function

    PubMed Central

    Kleinhenz, Jennifer M.; Murphy, Tamara C.; Pokutta-Paskaleva, Anastassia P.; Gleason, Rudolph L.; Lyle, Alicia N.; Taylor, W. Robert; Blount, Mitsi A.; Cheng, Juan; Yang, Qinglin; Sutliff, Roy L.; Hart, C. Michael

    2015-01-01

    Activation of the nuclear hormone receptor, PPARγ, with pharmacological agonists promotes a contractile vascular smooth muscle cell phenotype and reduces oxidative stress and cell proliferation, particularly under pathological conditions including vascular injury, restenosis, and atherosclerosis. However, pharmacological agonists activate both PPARγ-dependent and -independent mechanisms in multiple cell types confounding efforts to clarify the precise role of PPARγ in smooth muscle cell structure and function in vivo. We, therefore, designed and characterized a mouse model with smooth muscle cell-targeted PPARγ overexpression (smPPARγOE). Our results demonstrate that smPPARγOE attenuated contractile responses in aortic rings, increased aortic compliance, caused aortic dilatation, and reduced mean arterial pressure. Molecular characterization revealed that compared to littermate control mice, aortas from smPPARγOE mice expressed lower levels of contractile proteins and increased levels of adipocyte-specific transcripts. Morphological analysis demonstrated increased lipid deposition in the vascular media and in smooth muscle of extravascular tissues. In vitro adenoviral-mediated PPARγ overexpression in human aortic smooth muscle cells similarly increased adipocyte markers and lipid uptake. The findings demonstrate that smooth muscle PPARγ overexpression disrupts vascular wall structure and function, emphasizing that balanced PPARγ activity is essential for vascular smooth muscle homeostasis. PMID:26451838

  3. Se Enhances MLCK Activation by Regulating Selenoprotein T (SelT) in the Gastric Smooth Muscle of Rats.

    PubMed

    Li, Jia-Ping; Zhou, Jing-Xuan; Wang, Qi; Gu, Gao-Qin; Yang, Shi-Jin; Li, Cheng-Ye; Qiu, Chang-Wei; Deng, Gan-Zhen; Guo, Meng-Yao

    2016-09-01

    Selenium (Se), a nutritionally essential trace element, is associated with health and disease. Selenoprotein T (SelT) was identified as a redoxin protein with a selenocystein, localizing in the endoplasmic reticulum. The myosin light chain kinase (MLCK) and myosin light chain (MLC) play key roles in the contraction process of smooth muscle. The present study was to detect the effect and mechanism of SelT on the contraction process of gastric smooth muscle. The WT rats were fed with different Se concentration diets, and Se and Ca(2+) concentrations were detected in the gastric smooth muscle. Western blot and qPCR were performed to determine SelT, CaM, MLCK, and MLC expressions. MLCK activity was measured by identifying the rates of [γ-32P]ATP incorporated into the MLC. The results showed Se and Ca(2+) concentrations were enhanced with Se intake in gastric smooth muscle tissues. With increasing Se, SelT, CaM, MLCK and MLC expressions increased, and MLCK and MLC activation improved in gastric smooth muscle tissue. The SelT RNA interference experiments showed that Ca(2+) release, MLCK activation, and MLC phosphorylation were regulated by SelT. Se affected the gastric smooth muscle constriction by regulating Ca(2+) release, MLCK activation, and MLC phosphorylation through SelT. Se plays a major role in regulating the contraction processes of gastric smooth muscle with the SelT. PMID:26779623

  4. Cation channels of the transient receptor potential superfamily: their role in physiological and pathophysiological processes of smooth muscle cells.

    PubMed

    Dietrich, Alexander; Chubanov, Vladimir; Kalwa, Hermann; Rost, Benjamin R; Gudermann, Thomas

    2006-12-01

    Smooth muscle cells (SMC) are essential components of many tissues of the body. Ion channels regulate their membrane potential, the intracellular Ca(2+) concentration ([Ca(2+)](i)) and their contractility. Among the ion channels expressed in SMC cation channels of the transient receptor potential (TRP) superfamily allow the entry of Na(+), Ca(2+) and Mg(2+). Members of the TRP superfamily are essential constituents of tonically active channels (TAC), receptor-operated channels (ROC), store-operated channels (SOC) and stretch-activated channels (SAC). This review focusses on TRP channels (TRPC1, TRPC3, TRPC4, TRPC5, TRPC6, TRPC7, TRPV2, TRPV4, TRPM4, TRPM7, TRPP2) whose physiological functions in SMC were dissected by downregulating channel activity in isolated tissues or by the analysis of gene-deficient mouse models. Their possible functional role and physiological regulation as homomeric or heteromeric channels in SMC are discussed. Moreover, TRP channels may also be responsible for pathophysiological processes involving SMC-like airway hyperresponsiveness and pulmonary hypertension. Therefore, they present important drug targets for future pharmacological interventions. PMID:16842858

  5. Migration of smooth muscle cells from the arterial anastomosis of arteriovenous fistulas requires Notch activation to form neointima.

    PubMed

    Liang, Ming; Wang, Yun; Liang, Anlin; Mitch, William E; Roy-Chaudhury, Prabir; Han, Guofeng; Cheng, Jizhong

    2015-09-01

    A major factor contributing to failure of arteriovenous fistulas (AVFs) is migration of smooth muscle cells into the forming neointima. To identify the source of smooth muscle cells in neointima, we created end-to-end AVFs by anastomosing the common carotid artery to the jugular vein and studied neural crest-derived smooth muscle cells from the carotid artery, which are Wnt1-positive during development. In Wnt1-cre-GFP mice, smooth muscle cells in the carotid artery but not the jugular vein are labeled with GFP. About half of the cells were GFP-positive in the neointima, indicating their migration from the carotid artery to the jugular vein in AVFs created in these mice. As fibroblast-specific protein-1 (FSP-1) regulates smooth muscle cell migration, we examined FSP-1 in failed AVFs and polytetrafluoroethylene grafts from patients with end-stage kidney disease or from AVFs in mice with chronic kidney disease. In smooth muscle cells of AVFs or polytetrafluoroethylene grafts, FSP-1 and activation of Notch1 are present. In smooth muscle cells, Notch1 increased RBP-Jκ transcription factor activity and RBP-Jκ stimulated FSP-1 expression. Conditional knockout of RBP-Jκ in smooth muscle cells or general knockout of FSP-1 suppressed neointima formation in AVFs in mice. Thus, the artery of AVFs is the major source of smooth muscle cells during neointima formation. Knockout of RBP-Jκ or FSP-1 ameliorates neointima formation and might improve AVF patency during long-term follow-up. PMID:25786100

  6. HEF-19-induced relaxation of colonic smooth muscles and the underlying mechanisms

    PubMed Central

    Wei, Yuan-Yuan; Sun, Lu-Lu; Fu, Shou-Ting

    2013-01-01

    AIM: To investigate the relaxant effect of chromane HEF-19 on colonic smooth muscles isolated from rabbits, and the underlying mechanisms. METHODS: The relaxant effect and action mechanisms of HEF-19 were investigated using descending colon smooth muscle of the rabbits. Preparations 1 cm long were mounted in 15-mL tissue baths containing Tyrode’s solution, maintained at 37 ± 0.5 °C and aerated with a mixture of 5% CO2 in oxygen (Carbogen). The tension and amplitude of the smooth muscle strips were recorded after adding HEF-19 (10-6, 10-5 and 10-4 mol/L). After cumulative administration of four antispasmodic agents, including acetylcholine chloride (Ach) (10-4 mol/L), histamine (10-4 mol/L), high-K+ (60 mmol/L) and BaCl2 (8.2 mmol/L), HEF-19 (3 × 10-7-3 × 10-4 mol/L) was added to investigate the relaxant effect of HEF-19. CaCl2 (10-4-2.5 × 10-3 mol/L) was added cumulatively to the smooth muscle preparations pretreated with and without HEF-19 (1 × 10-6 or 3 × 10-6 mol/L) and verapamil (1 × 10-7 mol/L) to study the mechanisms involved. Finally, phasic contraction was induced with ACh (15 × 10-6 mol/L), and CaCl2 (4 × 10-3 mol/L) was added to the smooth muscle preparations pretreated with and without HEF-19 (3 × 10-6 mol/L or 1 × 10-5 mol/L) and verapamil (1 × 10-7 mol/L) in calcium-free medium to further study the underlying mechanisms. RESULTS: HEF-19 (1 × 10-6, 1 × 10-5 and 1 × 10-4 mol/L) suppressed spontaneous contraction of rabbit colonic smooth muscles. HEF-19 (3 × 10-7-3 × 10-4 mol/L) relaxed in a concentration-dependent manner colonic smooth muscle preparations pre-contracted with BaCl2, high-K+ solution, Ach or histamine with respective EC50 values of 5.15 ± 0.05, 5.12 ± 0.08, 5.58 ± 0.16 and 5.25 ± 0.24, thus showing a spasmolytic activity. HEF-19 (1 × 10-6 mol/L and 3 × 10-6 mol/L) shifted the concentration-response curves of CaCl2 to the right and depressed the maximum response to CaCl2. The two components contracted by Ach were

  7. Generation of vascular endothelial and smooth muscle cells from human pluripotent stem cells

    PubMed Central

    Patsch, Christoph; Challet-Meylan, Ludivine; Thoma, Eva C.; Urich, Eduard; Heckel, Tobias; O’Sullivan, John F; Grainger, Stephanie J; Kapp, Friedrich G.; Sun, Lin; Christensen, Klaus; Xia, Yulei; Florido, Mary H. C.; He, Wei; Pan, Wei; Prummer, Michael; Warren, Curtis R.; Jakob-Roetne, Roland; Certa, Ulrich; Jagasia, Ravi; Freskgård, Per-Ola; Adatto, Isaac; Kling, Dorothee; Huang, Paul; Zon, Leonard I; Chaikof, Elliot L.; Gerszten, Robert E.; Graf, Martin; Iacone, Roberto; Cowan, Chad A.

    2015-01-01

    The use of human pluripotent stem cells for in vitro disease modeling and clinical applications requires protocols that convert these cells into relevant adult cell types. Here, we report the rapid and efficient differentiation of human pluripotent stem cells into vascular endothelial and smooth muscle cells. We found that GSK3 inhibition and BMP4 treatment rapidly committed pluripotent cells to a mesodermal fate and subsequent exposure to VEGF or PDGF-BB resulted in the differentiation of either endothelial or vascular smooth muscle cells, respectively. Both protocols produced mature cells with efficiencies over 80% within six days. Upon purification to 99% via surface markers, endothelial cells maintained their identity, as assessed by marker gene expression, and showed relevant in vitro and in vivo functionality. Global transcriptional and metabolomic analyses confirmed that the cells closely resembled their in vivo counterparts. Our results suggest that these cells could be used to faithfully model human disease. PMID:26214132

  8. Generation of vascular endothelial and smooth muscle cells from human pluripotent stem cells.

    PubMed

    Patsch, Christoph; Challet-Meylan, Ludivine; Thoma, Eva C; Urich, Eduard; Heckel, Tobias; O'Sullivan, John F; Grainger, Stephanie J; Kapp, Friedrich G; Sun, Lin; Christensen, Klaus; Xia, Yulei; Florido, Mary H C; He, Wei; Pan, Wei; Prummer, Michael; Warren, Curtis R; Jakob-Roetne, Roland; Certa, Ulrich; Jagasia, Ravi; Freskgård, Per-Ola; Adatto, Isaac; Kling, Dorothee; Huang, Paul; Zon, Leonard I; Chaikof, Elliot L; Gerszten, Robert E; Graf, Martin; Iacone, Roberto; Cowan, Chad A

    2015-08-01

    The use of human pluripotent stem cells for in vitro disease modelling and clinical applications requires protocols that convert these cells into relevant adult cell types. Here, we report the rapid and efficient differentiation of human pluripotent stem cells into vascular endothelial and smooth muscle cells. We found that GSK3 inhibition and BMP4 treatment rapidly committed pluripotent cells to a mesodermal fate and subsequent exposure to VEGF-A or PDGF-BB resulted in the differentiation of either endothelial or vascular smooth muscle cells, respectively. Both protocols produced mature cells with efficiencies exceeding 80% within six days. On purification to 99% via surface markers, endothelial cells maintained their identity, as assessed by marker gene expression, and showed relevant in vitro and in vivo functionality. Global transcriptional and metabolomic analyses confirmed that the cells closely resembled their in vivo counterparts. Our results suggest that these cells could be used to faithfully model human disease. PMID:26214132

  9. Vanilloid and Melastatin Transient Receptor Potential Chann