Specific reaginic antibody IgG1-induced changes of airway smooth muscle cells

It was found that 1) an administration of both immunoglobulin G1 (IgG1) or immunized serum caused an immediate depolarization and an increase in the isometric force of airway smooth muscle (ASM) cells, followed by a sustained hyperpolarization and a return of the tone to the base-line values; 2) an IgG1 concentration-dependent relationship was found between a peak depolarization, a peak hyperpolarization, and a peak isometric force; for these events 50% effective dose (ED50) was found to be 0.17, 0.14, and 0.25 microgram/ml of IgG1, respectively; 3) both electrical and contractile responses to ovalbumin of ASM cells sensitized with IgG1 were also dependent on the concentration of IgG1; the ED50 values of this relationship were 0.27 and 0.25 micrograms/ml of IgG1, respectively; 4) amiloride (10(-8) to 10(-5) M) pretreatment and a sodium-deficient environment attenuated sensitized-induced electrical and contractile changes as well as the response of ASM to ovalbumin (0.1%); and 5) pretreatment of ASM with diphenhydramine (10(-5) M) or FPL 55712 (10(-6) M) had no effect on sensitization-induced changes in membrane potential but attenuated electrical and contractile response of ASM to ovalbumin (0.1%).

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Prostanoids mediate IL-1β-induced β-adrenergic hyporesponsiveness in human airway smooth muscle cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1998.275.3.l491 ◽

1998 ◽

Vol 275 (3) ◽

pp. L491-L501 ◽

Cited By ~ 24

Author(s):

Johanne D. Laporte ◽

Paul E. Moore ◽

Reynold A. Panettieri ◽

Winfried Moeller ◽

Joachim Heyder ◽

...

Keyword(s):

Smooth Muscle ◽

Airway Smooth Muscle ◽

Cell Stiffness ◽

Airway Smooth Muscle Cells ◽

Human Airway Smooth Muscle ◽

Human Airway ◽

Heterologous Desensitization ◽

Cox 2 ◽

Inhibitor Of Protein Synthesis ◽

Induced Changes

We have previously reported that pretreatment of cultured human airway smooth muscle (HASM) cells with interleukin-1β (IL-1β) results in decreased β-adrenergic responsiveness. The purpose of this study was to determine whether prostanoids released as a result of cyclooxygenase-2 (COX-2) induction by IL-1β contribute to this effect of the cytokine. Confluent serum-deprived HASM cells were studied in passages 4–7. IL-1β (20 ng/ml for 22 h) reduced the ability of the β-agonist isoproterenol (Iso) to decrease stiffness of HASM cells as measured by magnetic twisting cytometry. The effect of IL-1β on Iso-induced changes in cell stiffness was abolished by nonselective [indomethacin (Indo), 10−6 M] and selective (NS-398, 10−5 M) COX-2 inhibitors. Indo and NS-398 also inhibited both the increased basal cAMP and the decreases in Iso-stimulated cAMP production induced by IL-1β. IL-1β (20 ng/ml for 22 h) caused an increase in both basal (15-fold) and arachidonic acid (AA)-stimulated (10-fold) PGE2 release. Indo blocked basal and AA-stimulated PGE2 release in both control and IL-1β-treated cells. NS-398 also markedly reduced basal and AA-stimulated PGE2release in IL-1β-treated cells but had no significant effect on AA-stimulated PGE2 release in control cells. Western blot analysis confirmed the induction of COX-2 by IL-1β. Exogenously administered PGE2(10−7 M, 22 h) caused a significant reduction in the ability of Iso to decrease cell stiffness, mimicking the effects of IL-1β. Cycloheximide (10 μg/ml for 24 h), an inhibitor of protein synthesis, also abolished the effects of IL-1β on Iso-induced cell stiffness changes and cAMP formation. In summary, our results indicate that IL-1β significantly increases prostanoid release by HASM cells as a result of increased COX-2 expression. The prostanoids appear to contribute to β-adrenergic hyporesponsiveness, perhaps by heterologous desensitization of the β2 receptor.

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Saponins of Dioscorea Nipponicae Inhibits IL-17A-Induced Changes in Biomechanical Behaviors of In Vitro Cultured Human Airway Smooth Muscle Cells

Journal of Engineering and Science in Medical Diagnostics and Therapy ◽

10.1115/1.4042317 ◽

2019 ◽

Vol 2 (1) ◽

Author(s):

Yue Wang ◽

Yifan Zhang ◽

Ming Zhang ◽

Jingjing Li ◽

Yan Pan ◽

...

Keyword(s):

Smooth Muscle ◽

Smooth Muscle Cells ◽

Airway Smooth Muscle ◽

Traction Force ◽

Muscle Cells ◽

Airway Smooth Muscle Cells ◽

Human Airway Smooth Muscle ◽

Human Airway ◽

Induced Changes

Airway hyperresponsiveness (AHR) is one of the main pathologic features of bronchial asthma, which is largely attributable to enhanced contractile response of asthmatic airway smooth muscle. Although β2 adrenergic receptor agonists are commonly used to relax airway smooth muscle for treating AHR, there are side effects such as desensitization of long-term use. Therefore, it is desirable to develop alternative relaxant for airway smooth muscle, preferably based on natural products. One potential candidate is the inexpensive and widely available natural herb saponins of Dioscorea nipponicae (SDN), which has recently been reported to suppress the level of inflammatory factor IL-17A in ovalbumin-induced mice, thereby alleviating the inflammation symptoms of asthma. Here, we evaluated the biomechanical effect of SDN on IL-17A-mediated changes of cultured human airway smooth muscle cells (HASMCs) in vitro. The stiffness and traction force of the cells were measured by optical magnetic twisting cytometry (OMTC), and Fourier transform traction microscopy (FTTM), respectively. The cell proliferation was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetry, the cell migration was measured by cell scratch test, and the changes of cell cytoskeleton were assessed by laser confocal microscopy. We found that the stiffness and traction force of HASMCs were enhanced along with the increases of IL-17A concentration and exposure time, and SDN treatment dose-dependently reduced these IL-17A-induced changes in cell mechanical properties. Furthermore, SDN alleviated IL-17A-mediated effects on HASMCs proliferation, migration, and cytoskeleton remodeling. These results demonstrate that SDN could potentially be a novel drug candidate as bronchodilator for treating asthma-associated AHR.

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Electromechanical coupling of ferret airway smooth muscle in response to leukotriene C4

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.6.2533 ◽

1989 ◽

Vol 66 (6) ◽

pp. 2533-2538 ◽

Cited By ~ 3

Author(s):

C. G. Murlas ◽

C. A. Doupnik

Keyword(s):

Smooth Muscle ◽

Membrane Potential ◽

Airway Smooth Muscle ◽

Electromechanical Coupling ◽

Isometric Force ◽

Force Generation ◽

Base Line ◽

Leukotriene C4 ◽

Force Transducers ◽

Intracellular Microelectrodes

We investigated the possible electrophysiological basis for the slow, prolonged force generation by airway smooth muscle (ASM) produced by leukotriene C4 (LTC4). Preparations of ASM were made from ferret trachea and placed in tissue microchambers for study. Some of these preparations were arranged so that force transducers and intracellular microelectrodes (with tip resistances of 30–80 M omega) could be used to measure isometric force and cell membrane potential (Em) simultaneously from ASM cells stimulated by LTC4. We found that ferret tracheal muscle was relatively sensitive to LTC4 and that this sensitivity was not significantly affected by atropine (1 microM), phentolamine (1 microM), propranolol (3 microM), and pyrilamine (1 microM). In a 1 nM solution of LTC4, Em was -54.0 +/- 1.2 mV from 18 impalements (n) from 6 animals (N) compared with a base-line value of -61.6 +/- 0.8 mV (n/N = 29/8, P less than 0.0005). This change did not lead to force generation, however. Higher concentrations of LTC4 led to progressive decreases in Em to which force generation was closely coupled. Concentrations greater than or equal to 70 nM led to phasic oscillations in Em of 0.6–0.8 Hz and 1.7 mV in amplitude, which were abolished by 10 microM verapamil, although the base-line Em was unaffected by this concentration. Although 300 nM LTE4 by itself caused only a small depolarization of ferret trachealis, it substantially antagonized the electromechanical responsiveness of this smooth muscle to LTC4. We conclude that ferret ASM is relatively sensitive to LTC4 and that there is an electrical basis for the slow, prolonged force generation caused by this mediator.

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Dynamic Cytosolic Ca2+ and Force Responses to Muscarinic Stimulation in Airway Smooth Muscle

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00596.2020 ◽

2021 ◽

Author(s):

Young-Soo Han ◽

Philippe F. Delmotte ◽

Grace M Arteaga ◽

Gary C. Sieck

Keyword(s):

Smooth Muscle ◽

Airway Smooth Muscle ◽

Contractile Response ◽

Isometric Force ◽

Dynamic Properties ◽

Maximum Force ◽

Dynamic Nature ◽

Regulatory Myosin Light Chain ◽

Static Assessment ◽

Phase Loop

During agonist stimulation of airway smooth muscle (ASM), agonists such as ACh induce a transient increase in cytosolic Ca2+ concentration ([Ca2+]cyt), which leads to a contractile response (excitation-contraction (E-C) coupling). Previously, the sensitivity of the contractile response of ASM to elevated [Ca2+]cyt (Ca2+ sensitivity) was assessed as the ratio of maximum force to maximum [Ca2+]cyt. However, this static assessment of Ca2+ sensitivity overlooks the dynamic nature of E-C coupling in ASM. In this study, we simultaneously measured [Ca2+]cyt and isometric force responses to three concentrations of ACh (1, 2.6 and 10 μM). Both maximum [Ca2+]cyt and maximum force responses were ACh concentration-dependent, but force increased disproportionately, thereby increasing static Ca2+ sensitivity. The dynamic properties of E-C coupling were assessed in several ways. The temporal delay between the onset of ACh-induced [Ca2+]cyt and onset force responses was not affected by ACh concentration. The rates of rise of the ACh-induced [Ca2+]cyt and force responses increased with increasing ACh concentration. The integral of the phase-loop plot of [Ca2+]cyt and force from onset to steady-state also increased with increasing ACh concentration, whereas the rate of relaxation remained unchanged. Although these results suggest an ACh concentration-dependent increase in the rate of cross-bridge recruitment and in the rate of rise of [Ca2+]cyt, the extent of regulatory myosin light chain (rMLC20) phosphorylation was not dependent on ACh concentration. We conclude that the dynamic properties of [Ca2+]cyt and force responses in ASM are dependent on ACh concentration but reflect more than changes in the extent of rMLC20 phosphorylation.

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Cholinergic neuromodulation by prostaglandin D2 in canine airway smooth muscle

Journal of Applied Physiology ◽

10.1152/jappl.1987.63.4.1396 ◽

1987 ◽

Vol 63 (4) ◽

pp. 1396-1400 ◽

Cited By ~ 37

Author(s):

J. Tamaoki ◽

K. Sekizawa ◽

P. D. Graf ◽

J. A. Nadel

Keyword(s):

Smooth Muscle ◽

Airway Smooth Muscle ◽

Contractile Response ◽

Electrical Field Stimulation ◽

Prostaglandin D2 ◽

Base Line ◽

Field Stimulation ◽

Electrical Field ◽

Adrenergic Antagonist

To determine whether prostaglandin D2 (PGD2) modulates cholinergic neurotransmission in airway smooth muscle and, if so, what the mechanism of action is, we studied bronchial segments from dogs under isometric conditions in vitro. PGD2 (10(-8)-10(-5) M) elicited dose-dependent muscle contraction, which was reduced after blockade of muscarinic receptors, so that 50% effective dose (ED50) increased from 1.3 +/- 0.3 X 10(-6) to 3.9 +/- 1.0 X 10(-6) M by atropine (10(-6) M) (mean +/- SE, P less than 0.05). Physostigmine, at a concentration insufficient to alter base-line tension (10(-8) M), enhanced the PGD2-induced contraction and decreased ED50 to 6.4 +/- 0.5 X 10(-7) M (P less than 0.05). When added at the highest doses that did not cause spontaneous contraction (1.9 +/- 0.5 X 10(-7) M), PGD2 increased the contractile response to electrical field stimulation (1–50 Hz) by 21.9 +/- 6.6% (P less than 0.001). In contrast to this effect, the response to administered acetylcholine was not affected by PGD2. On the other hand, PGD2-induced augmentation of the response to electrical field stimulation (5 Hz) was further increased from 23.6 +/- 3.0 to 70.4 +/- 8.8% in the presence of physostigmine (10(-8) M) and was abolished by atropine but not affected by the alpha-adrenergic antagonist phentolamine or the histamine H1-blocker pyrilamine. These results suggest that the contraction of airway smooth muscle induced by PGD2 is in in part mediated by a cholinergic action and that PGD2 prejunctionally augments the parasympathetic contractile response, likely involving the accelerated release of acetylcholine at the neuromuscular junction.

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