VRAC Complex Modulates Mechano-Electrical Signal Responses in Human Airway Smooth Muscle Shortening.

Leucine-rich repeat containing 8A (LRRC8A) is an obligatory constituent of the volume-regulated anion channel (VRAC) that is fundamental to a wide range of biological processes, including regulating cell size, proliferation, and migration. Here we explored the physiological role for VRAC in excitation-contraction (E-C) coupling and shortening of human airway smooth muscle (HASM). In HASM cells, pharmacological inhibition of VRAC with DCPIB (0.

Prorelaxant E-type Prostanoid Receptors Functionally Partition to Different Procontractile Receptors in Airway Smooth Muscle.

Prostaglandin E2 imparts diverse physiological effects on multiple airway cells through its actions on four distinct E-type prostanoid (EP) receptor subtypes (EP1-EP4). Gs-coupled EP2 and EP4 receptors are expressed on airway smooth muscle (ASM), yet their capacity to regulate the ASM contractile state remains subject to debate. We used EP2 and EP4 subtype-specific agonists (ONO-259 and ONO-329, respectively) in cell- and tissue-based models of human ASM contraction-magnetic twisting cytometry (MTC), and precision-cut lung slices (PCLSs), respectively-to study the EP2 and EP4 regulation of ASM contraction and signaling under conditions of histamine or methacholine (MCh) stimulation.

Identification of a β-arrestin-biased negative allosteric modulator for the β-adrenergic receptor.

Catecholamine-stimulated β-adrenergic receptor (βAR) signaling via the canonical G-adenylyl cyclase-cAMP-PKA pathway regulates numerous physiological functions, including the therapeutic effects of exogenous β-agonists in the treatment of airway disease. βAR signaling is tightly regulated by GRKs and β-arrestins, which together promote βAR desensitization and internalization as well as downstream signaling, often antithetical to the canonical pathway. Thus, the ability to βAR signaling toward the G pathway while avoiding β-arrestin-mediated effects may provide a strategy to improve the functional consequences of βAR activation.

Cells in the polyaneuploid cancer cell (PACC) state have increased metastatic potential.

Although metastasis is the leading cause of cancer deaths, it is quite rare at the cellular level. Only a rare subset of cancer cells (~ 1 in 1.5 billion) can complete the entire metastatic cascade: invasion, intravasation, survival in the circulation, extravasation, and colonization (i.

A Par3/LIM Kinase/Cofilin Pathway Mediates Human Airway Smooth Muscle Relaxation by TAS2R14.

TAS2Rs (bitter taste receptors) are GPCRs (G protein-coupled receptors) expressed on human airway smooth muscle (HASM) cells; when activated by receptor agonists they evoke marked airway relaxation. In both taste and HASM cells, TAS2Rs activate a canonical G-mediated stimulation of Ca release from intracellular stores by activation of PLCβ (phospholipase Cβ). Alone, this [Ca] signaling does not readily account for relaxation, particularly since bronchoconstrictive agonists acting at G-coupled receptors also increase [Ca].

Mendelian Randomization Analysis Reveals a Complex Genetic Interplay among Atopic Dermatitis, Asthma, and Gastroesophageal Reflux Disease.

Gastroesophageal reflux disease (GERD) is commonly associated with atopic disorders, but cause-effect relationships remain unclear. We applied Mendelian randomization analysis to explore whether GERD is causally related to atopic disorders of the lung (asthma) and/or skin (atopic dermatitis [AD]). We conducted two-sample bidirectional Mendelian randomization to infer the magnitude and direction of causality between asthma and GERD, using summary statistics from the largest genome-wide association studies conducted on asthma ( = 56,167) and GERD ( = 71,522).

Epinephrine evokes shortening of human airway smooth muscle cells following β adrenergic receptor desensitization.

Epinephrine (EPI), an endogenous catecholamine involved in the body's fight-or-flight responses to stress, activates α-adrenergic receptors (αARs) expressed on various organs to evoke a wide range of physiological functions, including vasoconstriction. In the smooth muscle of human bronchi, however, the functional role of EPI on αARs remains controversial. Classically, evidence suggests that EPI promotes bronchodilation by stimulating β-adrenergic receptors (βARs).

β -Adrenoceptor agonist profiling reveals biased signalling phenotypes for the β -adrenoceptor with possible implications for the treatment of asthma.

Background And Purpose: β-Adrenoceptor agonists relieve airflow obstruction by activating β -adrenoceptors, which are G protein-coupled receptors (GPCRs) expressed on human airway smooth muscle (HASM) cells. The currently available β-adrenoceptor agonists are balanced agonists, however, and signal through both the stimulatory G protein (G )- and β-arrestin-mediated pathways. While G signalling is beneficial and promotes HASM relaxation, β-arrestin activation is associated with reduced G efficacy.

Selective Signal Capture from Multidimensional GPCR Outputs with Biased Agonists: Progress Towards Novel Drug Development.

G protein coupled receptors (GPCRs) are a superfamily of transmembrane-spanning receptors that are activated by multiple endogenous ligands and are the most common target for agonist or antagonist therapeutics across a broad spectrum of diseases. Initial characterization within the superfamily suggested that a receptor activated a single intracellular pathway, depending on the G protein to which it coupled. However, it has become apparent that a given receptor can activate multiple different pathways, some being therapeutically desirable, while others are neutral or promote deleterious signaling.

Identification and characterization of an atypical Gαs-biased βAR agonist that fails to evoke airway smooth muscle cell tachyphylaxis.

G protein-coupled receptors display multifunctional signaling, offering the potential for agonist structures to promote conformational selectivity for biased outputs. For β-adrenergic receptors (βAR), unbiased agonists stabilize conformation(s) that evoke coupling to Gαs (cyclic adenosine monophosphate [cAMP] production/human airway smooth muscle [HASM] cell relaxation) and β-arrestin engagement, the latter acting to quench Gαs signaling, contributing to receptor desensitization/tachyphylaxis. We screened a 40-million-compound scaffold ranking library, revealing unanticipated agonists with dihydroimidazolyl-butyl-cyclic urea scaffolds.

Inhibition of ABCC1 Decreases cAMP Egress and Promotes Human Airway Smooth Muscle Cell Relaxation.

In most living cells, the second-messenger roles for adenosine 3',5'-cyclic monophosphate (cAMP) are short-lived, confined to the intracellular space, and tightly controlled by the binary switch-like actions of Gα (stimulatory G protein)-activated adenylyl cyclase (cAMP production) and cAMP-specific PDE (cAMP breakdown). Here, by using human airway smooth muscle (HASM) cells in culture as a model, we report that activation of the cell-surface βAR (β-adrenoceptor), a G-coupled GPCR (G protein-coupled receptor), evokes cAMP egress to the extracellular space. Increased extracellular cAMP levels ([cAMP]) are long-lived in culture and are induced by receptor-dependent and receptor-independent mechanisms in such a way as to define a universal response class of increased intracellular cAMP levels ([cAMP]).

Degradation of Premature-miR-181b by the Translin/Trax RNase Increases Vascular Smooth Muscle Cell Stiffness.

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Molecular Nanomechanical Mapping of Histamine-Induced Smooth Muscle Cell Contraction and Shortening.

Mechanical response to external stimuli is a conserved feature of many cell types. For example, neurotransmitters (e.g.

PGC1/PPAR drive cardiomyocyte maturation at single cell level via YAP1 and SF3B2.

Cardiomyocytes undergo significant structural and functional changes after birth, and these fundamental processes are essential for the heart to pump blood to the growing body. However, due to the challenges of isolating single postnatal/adult myocytes, how individual newborn cardiomyocytes acquire multiple aspects of the mature phenotype remains poorly understood. Here we implement large-particle sorting and analyze single myocytes from neonatal to adult hearts.

Identification and Characterization of Novel Bronchodilator Agonists Acting at Human Airway Smooth Muscle Cell TAS2R5.

Bitter taste receptors (TAS2Rs) are recognized as being expressed on multiple cell types and organs, including human airway smooth muscle (HASM) cells, where agonists promote significant relaxation to constrictive stimuli. Thus, the HASM TAS2Rs have been targeted as novel bronchodilators for the treatment of asthma and other obstructive lung diseases. The TAS2R5 subtype, a dominant receptor on HASM, has few known agonists, all with reported low potency and efficacy.

FFAR1 activation attenuates histamine-induced myosin light chain phosphorylation and cortical tension development in human airway smooth muscle cells.

Background: Activation of free fatty acid receptors (FFAR1 and FFAR4) which are G protein-coupled receptors (GPCRs) with established (patho)physiological roles in a variety of obesity-related disorders, induce human airway smooth muscle (HASM) cell proliferation and shortening. We reported amplified agonist-induced cell shortening in HASM cells obtained from obese lung donors. We hypothesized that FFAR1 modulate excitation-contraction (EC) coupling in HASM cells and play a role in obesity-associated airway hyperresponsiveness.

The odorant receptor OR2W3 on airway smooth muscle evokes bronchodilation via a cooperative chemosensory tradeoff between TMEM16A and CFTR.

The recent discovery of sensory (tastant and odorant) G protein-coupled receptors on the smooth muscle of human bronchi suggests unappreciated therapeutic targets in the management of obstructive lung diseases. Here we have characterized the effects of a wide range of volatile odorants on the contractile state of airway smooth muscle (ASM) and uncovered a complex mechanism of odorant-evoked signaling properties that regulate excitation-contraction (E-C) coupling in human ASM cells. Initial studies established multiple odorous molecules capable of increasing intracellular calcium ([Ca]) in ASM cells, some of which were (paradoxically) associated with ASM relaxation.

Cystic fibrosis transmembrane conductance regulator function, not TAS2R38 gene haplotypes, predict sinus surgery in children and young adults with cystic fibrosis.

Background: Chronic rhinosinusitis symptomatology begins in early childhood individuals with cystic fibrosis (CF). Cystic fibrosis transmembrane conductance regulator (CFTR) function contributes to sinus development and disease. Genetic variants of the bitter taste receptor TAS2R38 have been suggested to contribute to sinus disease severity in individuals without CF.

Role of Isocitrate Dehydrogenase 2 on DNA Hydroxymethylation in Human Airway Smooth Muscle Cells.

Global DNA hydroxymethylation mediated by the TET (ten-eleven translocation) enzyme was induced in allergen-induced airway hyperresponsiveness in mouse lung tissues and specifically in isolated airway smooth muscle (ASM) cells. TET is an α-ketoglutarate (α-KG)-dependent enzyme, and the production of α-KG is catalyzed by IDH (isocitrate dehydrogenase). However, the role of IDH in the regulation of DNA hydroxymethylation in ASM cells is unknown.

Deletion of the microRNA-degrading nuclease, translin/trax, prevents pathogenic vascular stiffness.

Vascular stiffness plays a key role in the pathogenesis of hypertension. Recent studies indicate that the age-associated reduction in miR-181b levels in vascular smooth muscle cells (VSMCs) contributes to increased vascular stiffness. As these findings suggest that inhibiting degradation of miR-181b might prevent vascular stiffening, we have assessed whether the microRNA-degrading translin/trax (TN/TX) complex mediates degradation of miR-181b in the aorta.