RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Ophiocordyceps sinensis (O. sinensis) is a genus of Ascomycete fungus that is endemic to the alpine meadows of the Tibetan Plateau and adjoining Himalayas. It has been used traditionally as a tonic to improve respiratory health in ancient China as well as to promote vitality and longevity. Bioactive components found in O. sinensis such as adenosine, cordycepin, 3-deoxyadenosine, L-arginine and polysaccharides have gained increasing interest in recent years due to their antioxidative and other properties, which include anti-asthmatic, antiviral, immunomodulation and improvement of general health. AIM OF THE STUDY: This study's primary aim was to investigate the effect of a cultivated fruiting body of O. sinensis strain (OCS02®) on airways patency and the secondary focus was to investigate its effect on the lifespan of Caenorhabditis elegans. MATERIALS AND METHODS: A cultivated strain, OCS02®, was employed and the metabolic profile of its cold-water extract (CWE) was analysed through liquid chromatography-mass spectrometry (LC-MS). Organ bath approach was used to investigate the pharmacological properties of OCS02® CWE when applied on airway tissues obtained from adult male Sprague-Dawley rats. The airway relaxation mechanisms of OCS02® CWE were explored using pharmacological tools, where the key regulators in airway relaxation and constriction were investigated. For the longevity study, age-synchronised, pos-1 RNAi-treated wild-type type Caenorhabditis elegans at the L4 stage were utilised for a lifespan assay. RESULTS: Various glycopeptides and amino acids, particularly a high concentration of L-arginine, were identified from the LC-MS analysis. In airway tissues, OCS02® CWE induced a significantly greater concentration-dependent relaxation when compared to salbutamol. The relaxation response was significantly attenuated in the presence of NG-Nitro-L-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ) and several K+ channel blockers. The longevity effect induced by OCS02® CWE (5 mg/mL and above) was observed in C. elegans by at least 17%. CONCLUSIONS: These findings suggest that the airway relaxation mechanisms of OCS02® CWE involved cGMP-dependent and cGMP-independent nitric oxide signalling pathways. This study provides evidence that the cultivated strain of OCS02® exhibits airway relaxation effects which supports the traditional use of its wild O. sinensis in strengthening respiratory health.
Asunto(s)
Cuerpos Fructíferos de los Hongos , Músculo Liso , Ratas Sprague-Dawley , Animales , Masculino , Cuerpos Fructíferos de los Hongos/química , Músculo Liso/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Ratas , Tráquea/efectos de los fármacos , Tráquea/metabolismo , Longevidad/efectos de los fármacos , HypocrealesRESUMEN
Since its first discovery as a bioactive phospholipid inducing potent platelet aggregation, platelet-activating factor (PAF) has been shown to be involved in a wide variety of inflammatory and allergic disease states. Many pharmacological studies in the 1980s and 1990s also showed that PAF induces endothelium-dependent vascular relaxation and contraction of various smooth muscles (SMs), including those in the airway, gastrointestinal organs, and uterus. However, since the late 1990s, there have been few reports on the SM contractions induced by PAF. The lower urinary tract (LUT), particularly the urinary bladder (UB) has attracted recent attention in SM pharmacology research because patients with LUT dysfunctions including overactive bladder are increasing as the population ages. In addition, recent clinical studies have implicated the substantial role of PAF in the inflammatory state in LUT because its production increases with smoking and with cancer. However, the effects of PAF on mechanical activities of LUT SMs including UBSM have not been investigated to date. Recently, we found that PAF very strongly increased mechanical activities of UBSM in guinea pigs and mice, and partly elucidated the possible mechanisms underlying these actions of PAF. In this review, we describe the effects of PAF on LUT SMs by introducing our recent findings obtained in isolated UBSMs and discuss the physiological and pathophysiological significance. We also introduce our data showing the effects of PAF on the SM mechanical activities of genital tissues (prostate and vas deferens).
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Contracción Muscular , Músculo Liso , Factor de Activación Plaquetaria , Factor de Activación Plaquetaria/farmacología , Factor de Activación Plaquetaria/metabolismo , Animales , Humanos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Músculo Liso/metabolismo , Contracción Muscular/efectos de los fármacos , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo , Vejiga Urinaria/fisiología , Masculino , FemeninoRESUMEN
Pulmonary surfactant serves as a barrier to respiratory epithelium but can also regulate airway smooth muscle (ASM) tone. Surfactant (SF) relaxes contracted ASM, similar to ß2-agonists, anticholinergics, nitric oxide, and prostanoids. The exact mechanism of surfactant relaxation and whether surfactant relaxes hyperresponsive ASM remains unknown. Based on previous research, relaxation requires an intact epithelium and prostanoid synthesis. We sought to examine the mechanisms by which surfactant causes ASM relaxation. Organ bath measurements of isometric tension of ASM of guinea pigs in response to exogenous surfactant revealed that surfactant reduces tension of healthy and hyperresponsive tracheal tissue. The relaxant effect of surfactant was reduced if prostanoid synthesis was inhibited and/or if prostaglandin E2-related EP2 receptors were antagonized. Atomic force microscopy revealed that human ASM cells stiffen during contraction and soften during relaxation. Surfactant softened ASM cells, similarly to the known bronchodilator prostaglandin E2 (PGE2) and the cell softening was abolished when EP4 receptors for PGE2 were antagonized. Elevated levels of PGE2 were found in cultures of normal human bronchial epithelial cells exposed to pulmonary surfactant. We conclude that prostaglandin E2 and its EP2 and EP4 receptors are likely involved in the relaxant effect of pulmonary surfactant in airways.
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Dinoprostona , Relajación Muscular , Músculo Liso , Surfactantes Pulmonares , Tráquea , Cobayas , Animales , Humanos , Masculino , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Músculo Liso/metabolismo , Relajación Muscular/efectos de los fármacos , Dinoprostona/farmacología , Dinoprostona/metabolismo , Surfactantes Pulmonares/metabolismo , Surfactantes Pulmonares/farmacología , Tráquea/efectos de los fármacos , Tráquea/fisiología , Tráquea/metabolismo , Subtipo EP2 de Receptores de Prostaglandina E/metabolismo , Células Cultivadas , Subtipo EP4 de Receptores de Prostaglandina E/metabolismoRESUMEN
The stomach, a central organ in the Gastrointestinal (GI) tract, regulates the processing of ingested food through gastric motility and emptying. Understanding the stomach function is crucial for treating gastric disorders. Experimental studies in this field often face difficulties due to limitations and invasiveness of available techniques and ethical concerns. To counter this, researchers resort to computational and numerical methods. However, existing computational studies often isolate one aspect of the stomach function while neglecting the rest and employ computationally expensive methods. This paper proposes a novel cost-efficient multi-compartmental model, offering a comprehensive insight into gastric function at an organ level, thus presenting a promising alternative. The proposed approach divides the spatial geometry of the stomach into four compartments: Proximal/Middle/Terminal antrum and Pyloric sphincter. Each compartment is characterized by a set of ordinary differential equations (ODEs) with respect to time to characterize the stomach function. Electrophysiology is represented by simplified equations reflecting the "slow wave behavior" of Interstitial Cells of Cajal (ICC) and Smooth Muscle Cells (SMC) in the stomach wall. An electro-mechanical coupling model translates SMC "slow waves" into smooth muscle contractions. Muscle contractions induce peristalsis, affecting gastric fluid flow velocity and subsequent emptying when the pyloric sphincter is open. Contraction of the pyloric sphincter initiates a retrograde flow jet at the terminal antrum, modeled by a circular liquid jet flow equation. The results from the proposed model for a healthy human stomach were compared with experimental and computational studies on electrophysiology, muscle tissue mechanics, and fluid behavior during gastric emptying. These findings revealed that each "ICC" slow wave corresponded to a muscle contraction due to electro-mechanical coupling behavior. The rate of gastric emptying and mixing efficiency decreased with increasing viscosity of gastric liquid but remained relatively unchanged with gastric liquid density variations. Utilizing different ODE solvers in MATLAB, the model was solved, with ode15s demonstrating the fastest computation time, simulating 180 s of real-time stomach response in just 2.7 s. This multi-compartmental model signifies a promising advancement in understanding gastric function, providing a cost-effective and comprehensive approach to study complex interactions within the stomach and test innovative therapies like neuromodulation for treating gastric disorders.
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Vaciamiento Gástrico , Modelos Biológicos , Estómago , Humanos , Vaciamiento Gástrico/fisiología , Estómago/fisiología , Músculo Liso/fisiología , Contracción Muscular/fisiología , Motilidad Gastrointestinal/fisiología , Células Intersticiales de Cajal/fisiología , Simulación por ComputadorRESUMEN
A thin film of pulmonary surfactant lines the surface of the airways and alveoli, where it lowers the surface tension in the peripheral lungs, preventing collapse of the bronchioles and alveoli and reducing the work of breathing. It also possesses a barrier function for maintaining the blood-gas interface of the lungs and plays an important role in innate immunity. The surfactant film covers the epithelium lining both large and small airways, forming the first line of defense between toxic airborne particles/pathogens and the lungs. Furthermore, surfactant has been shown to relax airway smooth muscle (ASM) after exposure to ASM agonists, suggesting a more subtle function. Whether surfactant masks irritant sensory receptors or interacts with one of them is not known. The relaxant effect of surfactant on ASM is absent in bronchial tissues denuded of an epithelial layer. Blocking of prostanoid synthesis inhibits the relaxant function of surfactant, indicating that prostanoids might be involved. Another possibility for surfactant to be active, namely through ATP-dependent potassium channels and the cAMP-regulated epithelial chloride channels [cystic fibrosis transmembrane conductance regulators (CFTRs)], was tested but could not be confirmed. Hence, this review discusses the mechanisms of known and potential relaxant effects of pulmonary surfactant on ASM. This review summarizes what is known about the role of surfactant in smooth muscle physiology and explores the scientific questions and studies needed to fully understand how surfactant helps maintain the delicate balance between relaxant and constrictor needs.
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Músculo Liso , Surfactantes Pulmonares , Humanos , Surfactantes Pulmonares/metabolismo , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Animales , Tono Muscular/efectos de los fármacos , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismoRESUMEN
Integrin activation resulting in enhanced adhesion to the extracellular matrix plays a key role in fundamental cellular processes. Although integrin activation has been extensively studied in circulating cells such as leukocytes and platelets, much less is known about the regulation and functional impact of integrin activation in adherent cells such as smooth muscle. Here, we show that two different asthmagenic cytokines, IL-13 and IL-17A, activate type I and IL-17 cytokine receptor families, respectively, to enhance adhesion of airway smooth muscle. These cytokines also induce activation of ß1 integrins detected by the conformation-specific antibody HUTS-4. Moreover, HUTS-4 binding is increased in the smooth muscle of patients with asthma compared to nonsmokers without lung disease, suggesting a disease-relevant role for integrin activation in smooth muscle. Indeed, integrin activation induced by the ß1-activating antibody TS2/16, the divalent cation manganese, or the synthetic peptide ß1-CHAMP that forces an extended-open integrin conformation dramatically enhances force transmission in smooth muscle cells and airway rings even in the absence of cytokines. We demonstrate that cytokine-induced activation of ß1 integrins is regulated by a common pathway of NF-κB-mediated induction of RhoA and its effector Rho kinase, which in turn stimulates PIP5K1γ-mediated synthesis of PIP2 at focal adhesions, resulting in ß1 integrin activation. Taken together, these data identify a pathway by which type I and IL-17 cytokine receptor family stimulation induces functionally relevant ß1 integrin activation in adherent smooth muscle and help to explain the exaggerated force transmission that characterizes chronic airway diseases such as asthma.
Asunto(s)
Asma , Integrina beta1 , Interleucina-13 , Interleucina-17 , Músculo Liso , FN-kappa B , Quinasas Asociadas a rho , Humanos , Integrina beta1/metabolismo , Interleucina-17/metabolismo , Músculo Liso/metabolismo , FN-kappa B/metabolismo , Quinasas Asociadas a rho/metabolismo , Interleucina-13/metabolismo , Asma/metabolismo , Transducción de Señal , Adhesión Celular , Miocitos del Músculo Liso/metabolismo , AnimalesRESUMEN
Disorders of gallbladder motility can lead to serious pathology. Bitter tastants acting upon bitter taste receptors (TAS2R family) have been proposed as a novel class of smooth muscle relaxants to combat excessive contraction in the airways and other organs. To explore whether this might also emerge as an option for gallbladder diseases, we here tested bitter tastants for relaxant properties and profiled Tas2r expression in the mouse gallbladder. In organ bath experiments, the bitter tastants denatonium, quinine, dextromethorphan, and noscapine, dose-dependently relaxed the pre-contracted gallbladder. Utilizing gene-deficient mouse strains, neither transient receptor potential family member 5 (TRPM5), nor the Tas2r143/Tas2r135/Tas2r126 gene cluster, nor tuft cells proved to be required for this relaxation, indicating direct action upon smooth muscle cells (SMC). Accordingly, denatonium, quinine and dextromethorphan increased intracellular calcium concentration preferentially in isolated gallbladder SMC and, again, this effect was independent of TRPM5. RT-PCR revealed transcripts of Tas2r108, Tas2r126, Tas2r135, Tas2r137, and Tas2r143, and analysis of gallbladders from mice lacking tuft cells revealed preferential expression of Tas2r108 and Tas2r137 in tuft cells. A TAS2R143-mCherry reporter mouse labeled tuft cells in the gallbladder epithelium. An in silico analysis of a scRNA sequencing data set revealed Tas2r expression in only few cells of different identity, and from in situ hybridization histochemistry, which did not label distinct cells. Our findings demonstrate profound tuft cell- and TRPM5-independent relaxing effects of bitter tastants on gallbladder smooth muscle, but do not support the concept that these effects are mediated by bitter receptors.
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Vesícula Biliar , Músculo Liso , Receptores Acoplados a Proteínas G , Canales Catiónicos TRPM , Animales , Ratones , Calcio/metabolismo , Dextrometorfano/farmacología , Vesícula Biliar/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Relajación Muscular/efectos de los fármacos , Músculo Liso/metabolismo , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/efectos de los fármacos , Noscapina/farmacología , Compuestos de Amonio Cuaternario/farmacología , Quinina/farmacología , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/genética , Transducción de Señal , Gusto/fisiología , Canales Catiónicos TRPM/metabolismo , Canales Catiónicos TRPM/genética , Células en Penacho/metabolismoAsunto(s)
Neoplasias Endometriales , Músculo Liso , Sarcoma Estromático Endometrial , Humanos , Femenino , Neoplasias Endometriales/patología , Sarcoma Estromático Endometrial/patología , Sarcoma Estromático Endometrial/diagnóstico , Diagnóstico Diferencial , Músculo Liso/patología , Diferenciación Celular , Vimentina/metabolismo , Adulto , Leiomioma/patología , Tumores de los Cordones Sexuales y Estroma de las Gónadas/patología , Tumores de los Cordones Sexuales y Estroma de las Gónadas/diagnóstico , Tumores Estromáticos Endometriales/patología , Tumores Estromáticos Endometriales/diagnóstico , Actinas/metabolismoRESUMEN
AIMS: It is well established that intracellular cAMP contributes to the relaxation of vas deferens smooth muscle. In many tissues, intracellular cAMP is actively transported to the extracellular space, where it exerts regulatory functions, via its metabolite adenosine. These actions take place through the cAMP conversion to adenosine by ectoenzymes, a process called "extracellular cAMP-adenosine pathway". Herein, we investigated whether, in addition to ATP, extracellular cAMP might be an alternative source of adenosine, influencing the contraction of vas deferens smooth muscle. MAIN METHODS: The effects of cAMP, 8-Br-cAMP and adenosine were analyzed in the isometric contractions of rat vas deferens. cAMP efflux was analyzed by measuring extracellular cAMP levels after exposure of vas deferens segments to isoproterenol and forskolin in the presence or absence of MK-571, an inhibitor of MRP/ABCC transporters. KEY FINDINGS: While 8-Br-cAMP, a cell-permeable cAMP analog, induced relaxation of KCl-precontracted vas deferens, the non-permeant cAMP increased the KCl-induced contractile response, which was mimicked by adenosine, but prevented by inhibitors of ecto-5'-nucleotidase or A1 receptors. Our results also showed that isoproterenol and forskolin increases cAMP efflux via an MRP/ABCC transporter-dependent mechanism, since it is inhibited by MK-571. SIGNIFICANCE: Our data show that activation of ß-adrenoceptors and adenylyl cyclase increases cAMP efflux from vas deferens tissue, which modulates the vas deferens contractile response via activation of adenosine A1 receptors. Assuming that inhibition of vas deferens contractility has been proposed as a strategy for male contraception, the extracellular cAMP-adenosine pathway emerges as a potential pharmacological target that should be considered in studies of male fertility.
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5'-Nucleotidasa , AMP Cíclico , Contracción Muscular , Ratas Wistar , Receptor de Adenosina A1 , Conducto Deferente , Masculino , Animales , Conducto Deferente/efectos de los fármacos , Conducto Deferente/metabolismo , AMP Cíclico/metabolismo , 5'-Nucleotidasa/metabolismo , Receptor de Adenosina A1/metabolismo , Receptor de Adenosina A1/efectos de los fármacos , Ratas , Contracción Muscular/efectos de los fármacos , Adenosina/farmacología , Adenosina/análogos & derivados , Adenosina/metabolismo , Isoproterenol/farmacología , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Colforsina/farmacologíaRESUMEN
Intestinal helminth infection triggers a type 2 immune response that promotes a 'weep-and sweep' response characterised by increased mucus secretion and intestinal hypermotility, which function to dislodge the worm from its intestinal habitat. Recent studies have discovered that several other pathogens cause intestinal dysmotility through major alterations to the immune and enteric nervous systems (ENS), and their interactions, within the gastrointestinal tract. However, the involvement of these systems has not been investigated for helminth infections. Eosinophils represent a key cell type recruited by the type 2 immune response and alter intestinal motility under steady-state conditions. Our study aimed to investigate whether altered intestinal motility driven by the murine hookworm, Nippostrongylus brasiliensis, infection involves eosinophils and how the ENS and smooth muscles of the gut are impacted. Eosinophil deficiency did not influence helminth-induced intestinal hypermotility and hypermotility did not involve gross structural or functional changes to the ENS. Hypermotility was instead associated with a dramatic increase in smooth muscle thickness and contractility, an observation that extended to another rodent nematode, Heligmosomoides polygyrus. In summary our data indicate that, in contrast to other pathogens, helminth-induced intestinal hypermotility is driven by largely by myogenic, rather than neurogenic, alterations with such changes occurring independently of eosinophils. (<300 words).
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Sistema Nervioso Entérico , Eosinófilos , Motilidad Gastrointestinal , Músculo Liso , Nippostrongylus , Animales , Ratones , Eosinófilos/inmunología , Músculo Liso/parasitología , Sistema Nervioso Entérico/parasitología , Sistema Nervioso Entérico/inmunología , Motilidad Gastrointestinal/fisiología , Nematospiroides dubius/fisiología , Nematospiroides dubius/inmunología , Infecciones por Strongylida/inmunología , Infecciones por Strongylida/parasitología , Parasitosis Intestinales/inmunología , Parasitosis Intestinales/parasitología , Helmintiasis/inmunología , Helmintiasis/parasitología , Neuronas/parasitología , Neuronas/metabolismo , Ratones Endogámicos C57BLRESUMEN
Determining the female animal cycle is crucial in preclinical studies and animal husbandry. Changes in hormone levels during the cycle affect physiological responses, including altered contractility of the visceral smooth muscle. The study aimed to identify estrus and anestrus using smooth muscle electromyographic (SMEMG) measurements, in vivo fluorescent imaging (IVIS) and in vitro organ contractility of the uterus and cecum. The study involved sexually mature female Sprague-Dawley rats, aged 10-12 weeks. The rats received a daily injection of cetrorelix acetate solution for 7 days, while another group served as the control. The animals were subjected to gastrointestinal and myometrial SMEMG. The change in αvß3 integrin activity was measured with IVIS in the abdominal cavity. Contractility studies were performed in isolated organ baths using dissected uterus and cecum samples. Plasma samples were collected for hormone level measurements. A 3-fold increase in spontaneous contraction activity was detected in SMEMG measurements, while a significant decrease in αvß3 integrin was measured in the IVIS imaging procedure. Cetrorelix reduced the level of LH and the progesterone / estradiol ratio, increased the spontaneous activity of the cecum rings, and enhanced KCl-evoked contractions in the uterus. We found a significant change in the rate of SMEMG signals, indicating simultaneous increases in the contraction of the cecum and the non-pregnant uterus, as evidenced by isolated organ bath results. Fluorescence imaging showed high levels of uterine αvß3 integrin during the proestrus-estrus phase, but inhibiting the sexual cycle reduced fluorescence activity. Based on the results, the SMEMG and IVIS imaging methods are suitable for detecting estrus phase alterations in rats.
Asunto(s)
Electromiografía , Ciclo Estral , Ratas Sprague-Dawley , Animales , Femenino , Ratas , Ciclo Estral/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/fisiología , Progesterona/sangre , Contracción Muscular/efectos de los fármacos , Estro/fisiología , Útero/fisiología , Útero/efectos de los fármacos , Ciego/efectos de los fármacos , Integrina alfaVbeta3/metabolismo , Estradiol/sangre , Estradiol/análogos & derivadosRESUMEN
The synthesized compound 1-(2-chlorophenyl) 6-7-dimethoxy-3-methyl-3,4-dihydroisoquinoline (DIQ) was investigated as a biological agent. Its potential to affect muscle contractility was predicted through in silico PASS analysis. Based on the in silico analysis, its capabilities were experimentally investigated. The study aimed to investigate the effects of DIQ on the ex vivo spontaneous contractile activity (CA) of smooth muscle (SM) tissue. DIQ was observed to reduce the strength of Ca2+-dependent contractions in SM preparations (SMP), possibly by increasing cytosolic Ca2+ levels through the activation of a voltage-gated L-type Ca2+ channel. DIQ potently affected calcium currents by modulating the function of muscarinic acetylcholine receptors (mAChRs) and 5-hydroxytryptamine (5-HT) receptors at a concentration of 50 µM. Immunohistochemical tests showed a 47% reduction in 5-HT2A and 5-HT2B receptor activity in SM cells and neurons in the myenteric plexus (MP), further confirming the effects of DIQ. Furthermore, a significant inhibition of neuronal activity was observed when the compound was co-administered with 5-HT to SM tissues. The conducted experiments confirm the ability of the isoquinoline analog to act as a physiologically active molecule to control muscle contractility and related physiological processes.
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Isoquinolinas , Contracción Muscular , Músculo Liso , Animales , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Isoquinolinas/farmacología , Isoquinolinas/química , Calcio/metabolismo , Receptores de Serotonina/metabolismo , Ratas , Receptores Muscarínicos/metabolismo , Masculino , Neuronas/efectos de los fármacos , Neuronas/metabolismoRESUMEN
Shortening of airway smooth muscle and bronchoconstriction are pathognomonic for asthma. Airway shortening occurs through calcium-dependent activation of myosin light chain kinase, and RhoA-dependent calcium sensitization, which inhibits myosin light chain phosphatase. The mechanism through which pro-contractile stimuli activate calcium sensitization is poorly understood. Our review of the literature suggests that pro-contractile G protein coupled receptors likely signal through G12/13 to activate RhoA and mediate calcium sensitization. This hypothesis is consistent with the effects of pro-contractile agonists on RhoA and Rho kinase activation, actin polymerization and myosin light chain phosphorylation. Recognizing the likely role of G12/13 signaling in the pathophysiology of asthma rationalizes the effects of pro-contractile stimuli on airway hyperresponsiveness, immune activation and airway remodeling, and suggests new approaches for asthma treatment.
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Asma , Transducción de Señal , Asma/metabolismo , Asma/fisiopatología , Asma/tratamiento farmacológico , Humanos , Transducción de Señal/fisiología , Animales , Subunidades alfa de la Proteína de Unión al GTP G12-G13/metabolismo , Músculo Liso/metabolismo , Músculo Liso/fisiopatología , Músculo Liso/efectos de los fármacos , Remodelación de las Vías Aéreas (Respiratorias)/fisiologíaRESUMEN
6-Cyanodopamine is a novel catecholamine released from rabbit isolated heart. However, it is not known whether this catecholamine presents any biological activity. Here, it was evaluated whether 6-cyanodopamine (6-CYD) is released from rat vas deferens and its effect on this tissue contractility. Basal release of 6-CYD, 6-nitrodopamine (6-ND), 6-bromodopamine, 6-nitrodopa, and 6-nitroadrenaline from vas deferens were quantified by LC-MS/MS. Electric-field stimulation (EFS) and concentration-response curves to noradrenaline, adrenaline, and dopamine of the rat isolated epididymal vas deferens (RIEVD) were performed in the absence and presence of 6-CYD and /or 6-ND. Expression of tyrosine hydroxylase was assessed by immunohistochemistry. The rat isolated vas deferens released significant amounts of both 6-CYD and 6-ND. The voltage-gated sodium channel blocker tetrodotoxin had no effect on the release of 6-CYD, but it virtually abolished 6-ND release. 6-CYD alone exhibited a negligible RIEVD contractile activity; however, at 10 nM, 6-CYD significantly potentiated the noradrenaline- and EFS-induced RIEVD contractions, whereas at 10 and 100 nM, it also significantly potentiated the adrenaline- and dopamine-induced contractions. The potentiation of noradrenaline- and adrenaline-induced contractions by 6-CYD was unaffected by tetrodotoxin. Co-incubation of 6-CYD (100 pM) with 6-ND (10 pM) caused a significant leftward shift and increased the maximal contractile responses to noradrenaline, even in the presence of tetrodotoxin. Immunohistochemistry revealed the presence of tyrosine hydroxylase in both epithelial cell cytoplasm of the mucosae and nerve fibers of RIEVD. The identification of epithelium-derived 6-CYD and its remarkable synergism with catecholamines indicate that epithelial cells may regulate vas deferens smooth muscle contractility.
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Dopamina , Contracción Muscular , Conducto Deferente , Masculino , Animales , Conducto Deferente/efectos de los fármacos , Conducto Deferente/metabolismo , Conducto Deferente/fisiología , Contracción Muscular/efectos de los fármacos , Ratas , Dopamina/metabolismo , Dopamina/farmacología , Ratas Wistar , Norepinefrina/farmacología , Norepinefrina/metabolismo , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Músculo Liso/fisiología , Estimulación Eléctrica , Epinefrina/farmacología , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Enhanced electrical activity in detrusor smooth muscle (DSM) cells is a key factor in detrusor overactivity which causes overactive bladder pathological disorders. Transient receptor potential melastatin-4 (TRPM4) channels, which are calcium-activated cation channels, play a role in regulating DSM electrical activities. These channels likely contribute to depolarizing the DSM cell membrane, leading to bladder overactivity. Our research focuses on understanding TRPM4 channel function in the DSM cells of mice, using computational modeling. We aimed to create a detailed computational model of the TRPM4 channel based on existing electrophysiological data. We employed a modified Hodgkin-Huxley model with an incorporated TRP-like current to simulate action potential firing in response to current and synaptic stimulus inputs. Validation against experimental data showed close agreement with our simulations. Our model is the first to analyze the TRPM4 channel's role in DSM electrical activity, potentially revealing insights into bladder overactivity. In conclusion, TRPM4 channels are pivotal in regulating human DSM function, and TRPM4 channel inhibitors could be promising targets for treating overactive bladder.
Asunto(s)
Simulación por Computador , Canales Catiónicos TRPM , Vejiga Urinaria Hiperactiva , Animales , Humanos , Ratones , Potenciales de Acción , Fenómenos Electrofisiológicos , Músculo Liso/metabolismo , Músculo Liso/fisiopatología , Canales Catiónicos TRPM/metabolismo , Vejiga Urinaria/metabolismo , Vejiga Urinaria/fisiopatología , Vejiga Urinaria Hiperactiva/metabolismo , Vejiga Urinaria Hiperactiva/fisiopatologíaRESUMEN
Transient receptor potential vanilloid 1 (TRPV1) is a calcium-permeable ion channel that is gated by the pungent constituent of red chili pepper, capsaicin, and by related chemicals from the group of vanilloids, in addition to noxious heat. It is expressed mostly in sensory neurons to act as a detector of painful stimuli produced by pungent chemicals and high temperatures. Although TRPV1 is also found outside the sensory nervous system, its expression and function in the bladder detrusor smooth muscle (DSM) remain controversial. Here, by using Ca2+ imaging and patch clamp on isolated rat DSM cells, in addition to tensiometry on multicellular DSM strips, we show that TRPV1 is expressed functionally in only a fraction of DSM cells, in which it acts as an endoplasmic reticulum Ca2+-release channel responsible for the capsaicin-activated [Ca2+]i rise. Carbachol-stimulated contractions of multicellular DSM strips contain a TRPV1-dependent component, which is negligible in the circular DSM but reaches ≤50% in the longitudinal DSM. Activation of TRPV1 in rat DSM during muscarinic cholinergic stimulation is ensured by phospholipase A2-catalysed derivation of arachidonic acid and its conversion by lipoxygenases to eicosanoids, which act as endogenous TRPV1 agonists. Immunofluorescence detection of TRPV1 protein in bladder sections and isolated DSM cells confirmed both its preferential expression in the longitudinal DSM sublayer and its targeting to the endoplasmic reticulum. We conclude that TRPV1 is an essential contributor to the cholinergic contraction of bladder longitudinal DSM, which might be important for producing spatial and/or temporal anisotropy of bladder wall deformation in different regions during parasympathetic stimulation. KEY POINTS: The transient receptor potential vanilloid 1 (TRPV1) heat/capsaicin receptor/channel is localized in the endoplasmic reticulum membrane of detrusor smooth muscle (DSM) cells of the rat bladder, operating as a calcium-release channel. Isolated DSM cells are separated into two nearly equal groups, within which the cells either show or do not show TRPV1-dependent [Ca2+]i rise. Carbachol-stimulated, muscarinic ACh receptor-mediated contractions of multicellular DSM strips contain a TRPV1-dependent component. This component is negligible in the circular DSM but reaches ≤50% in longitudinal DSM. Activation of TRPV1 in rat DSM during cholinergic stimulation involves phospholipase A2-catalysed derivation of arachidonic acid and its conversion by lipoxygenases to eicosanoids, which act as endogenous TRPV1 agonists.
Asunto(s)
Contracción Muscular , Músculo Liso , Canales Catiónicos TRPV , Vejiga Urinaria , Animales , Canales Catiónicos TRPV/metabolismo , Vejiga Urinaria/fisiología , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/metabolismo , Contracción Muscular/fisiología , Músculo Liso/fisiología , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Ratas , Masculino , Carbacol/farmacología , Capsaicina/farmacología , Calcio/metabolismo , Ratas Sprague-Dawley , Ratas WistarRESUMEN
G-protein-coupled receptors (GPCRs) belonging to the type 2 taste receptors (TAS2Rs) family are predominantly present in taste cells to allow the perception of bitter-tasting compounds. TAS2Rs have also been shown to be expressed in human airway smooth muscle (ASM), and TAS2R agonists relax ASM cells and bronchodilate airways despite elevating intracellular calcium. This calcium "paradox" (calcium mediates contraction by pro-contractile Gq-coupled GPCRs) and the mechanisms by which TAS2R agonists relax ASM remain poorly understood. To gain insight into pro-relaxant mechanisms effected by TAS2Rs, we employed an unbiased phosphoproteomic approach involving dual-mass spectrometry to determine differences in the phosphorylation of contractile-related proteins in ASM following the stimulation of cells with TAS2R agonists, histamine (an agonist of the Gq-coupled H1 histamine receptor) or isoproterenol (an agonist of the Gs-coupled ß2-adrenoceptor) alone or in combination. Our study identified differential phosphorylation of proteins regulating contraction, including A-kinase anchoring protein (AKAP)2, AKAP12, and RhoA guanine nucleotide exchange factor (ARHGEF)12. Subsequent signaling analyses revealed RhoA and the T853 residue on myosin light chain phosphatase (MYPT)1 as points of mechanistic divergence between TAS2R and Gs-coupled GPCR pathways. Unlike Gs-coupled receptor signaling, which inhibits histamine-induced myosin light chain (MLC)20 phosphorylation via protein kinase A (PKA)-dependent inhibition of intracellular calcium mobilization, HSP20 and ERK1/2 activity, TAS2Rs are shown to inhibit histamine-induced pMLC20 via inhibition of RhoA activity and MYPT1 phosphorylation at the T853 residue. These findings provide insight into the TAS2R signaling in ASM by defining a distinct signaling mechanism modulating inhibition of pMLC20 to relax contracted ASM.
Asunto(s)
Músculo Liso , Receptores Acoplados a Proteínas G , Humanos , Receptores Acoplados a Proteínas G/metabolismo , Receptores Acoplados a Proteínas G/agonistas , Músculo Liso/metabolismo , Músculo Liso/efectos de los fármacos , Fosforilación , Relajación Muscular/efectos de los fármacos , Histamina/metabolismo , Histamina/farmacología , Fosfatasa de Miosina de Cadena Ligera/metabolismo , Isoproterenol/farmacología , Calcio/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Gusto/fisiología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/efectos de los fármacos , Transducción de Señal , Células CultivadasRESUMEN
Cross talk between T cells and airway smooth muscle (ASM) may play a role in modulating asthmatic airway inflammation and remodeling. Infiltrating T cells have been observed within the ASM bundles of asthmatics, and a wide range of direct and indirect interactions between T cells and ASM has been demonstrated using various in vitro and in vivo model systems. Contact-dependent mechanisms such as ligation and activation of cellular adhesion and costimulatory molecules, as well as the formation of lymphocyte-derived membrane conduits, facilitate the adhesion, bidirectional communication, and transfer of materials between T and ASM cells. T cell-derived cytokines, particularly of the Th1, Th2, and Th17 subsets, modulate the secretome, proliferation, and contractility of ASM cells. This review summarizes the mechanisms governing T cell-ASM cross talk in the context of asthma. Understanding the underlying mechanistic basis is important for directing future research and developing therapeutic interventions targeted toward this complex interaction.
Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias) , Asma , Comunicación Celular , Músculo Liso , Humanos , Asma/patología , Asma/inmunología , Asma/metabolismo , Remodelación de las Vías Aéreas (Respiratorias)/inmunología , Animales , Músculo Liso/metabolismo , Músculo Liso/patología , Inflamación/patología , Inflamación/metabolismo , Inflamación/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Citocinas/metabolismo , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/patologíaRESUMEN
Gut motility undergoes a switch from myogenic to neurogenic control in late embryonic development. Here, we report on the electrical events that underlie this transition in the enteric nervous system, using the GCaMP6f reporter in neural crest cell derivatives. We found that spontaneous calcium activity is tetrodotoxin (TTX) resistant at stage E11.5, but not at E18.5. Motility at E18.5 was characterized by periodic, alternating high- and low-frequency contractions of the circular smooth muscle; this frequency modulation was inhibited by TTX. Calcium imaging at the neurogenic-motility stages E18.5-P3 showed that CaV1.2-positive neurons exhibited spontaneous calcium activity, which was inhibited by nicardipine and 2-aminoethoxydiphenyl borate (2-APB). Our protocol locally prevented muscle tone relaxation, arguing for a direct effect of nicardipine on enteric neurons, rather than indirectly by its relaxing effect on muscle. We demonstrated that the ENS was mechanosensitive from early stages on (E14.5) and that this behaviour was TTX and 2-APB resistant. We extended our results on L-type channel-dependent spontaneous activity and TTX-resistant mechanosensitivity to the adult colon. Our results shed light on the critical transition from myogenic to neurogenic motility in the developing gut, as well as on the intriguing pathways mediating electro-mechanical sensitivity in the enteric nervous system. HIGHLIGHTS: What is the central question of this study? What are the first neural electric events underlying the transition from myogenic to neurogenic motility in the developing gut, what channels do they depend on, and does the enteric nervous system already exhibit mechanosensitivity? What is the main finding and its importance? ENS calcium activity is sensitive to tetrodotoxin at stage E18.5 but not E11.5. Spontaneous electric activity at fetal and adult stages is crucially dependent on L-type calcium channels and IP3R receptors, and the enteric nervous system exhibits a tetrodotoxin-resistant mechanosensitive response. Abstract figure legend Tetrodotoxin-resistant Ca2+ rise induced by mechanical stimulation in the E18.5 mouse duodenum.
Asunto(s)
Canales de Calcio Tipo L , Calcio , Sistema Nervioso Entérico , Motilidad Gastrointestinal , Neuronas , Tetrodotoxina , Animales , Canales de Calcio Tipo L/metabolismo , Tetrodotoxina/farmacología , Sistema Nervioso Entérico/efectos de los fármacos , Sistema Nervioso Entérico/metabolismo , Sistema Nervioso Entérico/fisiología , Ratones , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuronas/fisiología , Motilidad Gastrointestinal/efectos de los fármacos , Motilidad Gastrointestinal/fisiología , Calcio/metabolismo , Músculo Liso/efectos de los fármacos , Músculo Liso/metabolismo , Músculo Liso/fisiología , Ratones Endogámicos C57BL , Bloqueadores de los Canales de Calcio/farmacología , Femenino , Contracción Muscular/efectos de los fármacos , Contracción Muscular/fisiología , Nicardipino/farmacología , Compuestos de BoroRESUMEN
Exposure to particulate matter (PM10) can induce respiratory diseases that are closely related to bronchial hyperresponsiveness. However, the involved mechanism remains to be fully elucidated. This study aimed to demonstrate the effects of PM10 on the acetylcholine muscarinic 3 receptor (CHRM3) expression and the role of the ERK1/2 pathway in rat bronchial smooth muscle. A whole-body PM10 exposure system was used to stimulate bronchial hyperresponsiveness in rats for 2 and 4 months, accompanied by MEK1/2 inhibitor U0126 injection. The whole-body plethysmography system and myography were used to detect the pulmonary and bronchoconstrictor function, respectively. The mRNA and protein levels were determined by Western blotting, qPCR, and immunofluorescence. Enzyme-linked immunosorbent assay was used to detect the inflammatory cytokines. Compared with the filtered air group, 4 months of PM10 exposure significantly increased CHRM3-mediated pulmonary function and bronchial constriction, elevated CHRM3 mRNA and protein expression levels on bronchial smooth muscle, then induced bronchial hyperreactivity. Additionally, 4 months of PM10 exposure caused an increase in ERK1/2 phosphorylation and increased the secretion of inflammatory factors in bronchoalveolar lavage fluid. Treatment with the MEK1/2 inhibitor, U0126 inhibited the PM10 exposure-induced phosphorylation of the ERK1/2 pathway, thereby reducing the PM10 exposure-induced upregulation of CHRM3 in bronchial smooth muscle and CHRM3-mediated bronchoconstriction. U0126 could rescue PM10 exposure-induced pathological changes in the bronchus. In conclusion, PM10 exposure can induce bronchial hyperresponsiveness in rats by upregulating CHRM3, and the ERK1/2 pathway may be involved in this process. These findings could reveal a potential therapeutic target for air pollution induced respiratory diseases.