scholarly journals Effect of proinflammatory cytokines on regulation of sarcoplasmic reticulum Ca2+ reuptake in human airway smooth muscle

2009 ◽  
Vol 297 (1) ◽  
pp. L26-L34 ◽  
Author(s):  
Venkatachalem Sathish ◽  
Michael A. Thompson ◽  
Jeffrey P. Bailey ◽  
Christina M. Pabelick ◽  
Y. S. Prakash ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Airway Inflammation ◽  
Airway Smooth Muscle ◽  
Proinflammatory Cytokines ◽  
Cell Types ◽  
Human Airway Smooth Muscle ◽  
Inhibitory Protein ◽  
Intracellular Ca ◽  
Additional Exposure

Airway inflammation leads to increased intracellular Ca2+ ([Ca2+]i) levels in airway smooth muscle (ASM) cells. Sarcoplasmic reticulum Ca2+ release and reuptake are key components of ASM [Ca2+]i regulation. Ca2+ reuptake occurs via sarcoendoplasmic reticulum Ca2+ ATPase (SERCA) and is regulated by the inhibitory protein phospholamban (PLB) in many cell types. In human ASM, we tested the hypothesis that inflammation increases PLB, thus inhibiting SERCA function, and leading to maintained [Ca2+]i levels. Surprisingly, we found that human ASM does not express PLB protein (although mRNA is detectable). Overnight exposure to the proinflammatory cytokines TNFα and IL-13 did not induce PLB expression, raising the issue of how SERCA is regulated. We then found that direct SERCA phosphorylation (via CaMKII) occurs in human ASM. In fura-2-loaded human ASM cells, we found that the CaMKII antagonist KN-93 significantly slowed the rate of fall of [Ca2+]i transients induced by ACh or bradykinin (in zero extracellular Ca2+), suggesting a role for CaMKII-mediated SERCA regulation. SERCA expression was decreased by cytokine exposure, and the rate of fall of [Ca2+]i transients was slowed in cells exposed to TNFα and IL-13. Cytokine effects on Ca2+ reuptake were unaffected by additional exposure to KN-93. These data indicate that in human ASM, SERCA is regulated by mechanisms such as CaMKII and that airway inflammation maintains [Ca2+]i levels by decreasing SERCA expression and slowing Ca2+ reuptake.

Selected Contribution: Tryptase-induced PAR-2-mediated Ca2+signaling in human airway smooth muscle cells

2001 ◽  
Vol 91 (2) ◽  
pp. 995-1003 ◽  
Author(s):  
Patrick Berger ◽  
J. Manuel Tunon-De-Lara ◽  
Jean-Pierre Savineau ◽  
Roger Marthan
Keyword(s):  
Smooth Muscle ◽  
Airway Inflammation ◽  
Airway Smooth Muscle ◽  
Airway Smooth Muscle Cells ◽  
Atpase Inhibitor ◽  
Human Airway Smooth Muscle ◽  
Human Airway ◽  
Transient Rise ◽  
Intracellular Ca ◽  
Protein Kinase C Inhibitor

Tryptase, the major mast cell product, is considered to play an important role in airway inflammation and hyperresponsiveness. Tryptase produces different, sometimes opposite, effects on airway responsiveness (bronchoprotection and/or airway contraction). This study was designed to examine the effect of human lung tryptase and activation of protease-activated receptor (PAR)-2 by synthetic activated peptide (AP) SLIGKV-NH2 on Ca2+ signaling in human airway smooth muscle (HASM) cells. Immunocytochemistry revealed that PAR-2 was expressed by HASM cells. Tryptase (7.5–30 mU/ml) induced a concentration-dependent transient relative rise in cytoplasmic Ca2+ concentration ([Ca2+]i) that reached 207 ± 32 nM ( n = 10) measured by indo 1 spectrofluorometry. The protease inhibitors leupeptin or benzamidine (100 μM) abolished tryptase-induced [Ca2+]iincrease. Activation of PAR-2 by AP (1–100 μM) also induced a concentration-dependent transient rise in [Ca2+]i, whereas the reverse peptide produced no effect. There was a homologous desensitization of the [Ca2+]i response on repeated stimulation with tryptase or AP. U-73122, a specific phospholipase C (PLC) antagonist, xestospongin, an inositol trisphosphate (IP3)-receptor antagonist, or thapsigargin, a sarcoplamic Ca2+-ATPase inhibitor, abolished tryptase-induced [Ca2+]iresponse, whereas Ca2+ removal, in the additional presence of EGTA, had no effect. Calphostin C, a protein kinase C inhibitor, increased PAR-2 [Ca2+]i response. Our results indicate that tryptase activates a [Ca2+]iresponse, which appears as PAR-2 mediated in HASM cells. Signal transduction implicates the intracellular Ca2+ store via PLC activation and thus via the IP3 pathway. This study provides evidence that tryptase, which is increasingly recognized as an important mediator in airway inflammation and hyperresponsiveness, is also a potent direct agonist at the site of airway smooth muscle.

scholarly journals Interleukin-6 family cytokines: signaling and effects in human airway smooth muscle cells

2001 ◽  
Vol 280 (6) ◽  
pp. L1225-L1232 ◽  
Author(s):  
Thomas Lahiri ◽  
Johanne D. Laporte ◽  
Paul E. Moore ◽  
Reynold A. Panettieri ◽  
Stephanie A. Shore
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Cell Types ◽  
Oncostatin M ◽  
Airway Smooth Muscle Cells ◽  
Human Airway Smooth Muscle ◽  
Human Airway ◽  
Cox 2 ◽  
Transcription 3 ◽  
Dose Dependent

Interleukin (IL)-1β induces cyclooxygenase (COX)-2 expression and prostanoid formation in cultured human airway smooth muscle (HASM) cells. In other cell types, IL-6 family cytokines induce COX-2 or augment IL-1β-induced COX-2 expression. The purpose of this study was to determine whether IL-6 family cytokines were involved in COX-2 expression in HASM cells. RT-PCR was used to demonstrate that the necessary receptor components for IL-6-type cytokine binding are expressed in HASM cells. IL-6 and oncostatin M (OSM) each caused a dose-dependent phosphorylation of signal transducer and activator of transcription-3, whereas IL-11 did not. IL-6, IL-11, and OSM alone had no effect on COX-2 expression. However, OSM caused dose-dependent augmentation of COX-2 expression and prostaglandin (PG) E2release induced by IL-1β. In contrast, IL-6 and IL-11 did not alter IL-1β-induced COX-2 expression. IL-6 did increase IL-1β-induced PGE2formation in unstimulated cells but not in cells stimulated with arachidonic acid (AA; 10−5M), suggesting that IL-6 effects were mediated at the level of AA release. Our results indicate that IL-6 and OSM are capable of inducing signaling in HASM cells. In addition, OSM and IL-1β synergistically cause COX-2 expression and PGE2release.

Regulation of store-operated Ca2+ entry by CD38 in human airway smooth muscle

2008 ◽  
Vol 294 (2) ◽  
pp. L378-L385 ◽  
Author(s):  
Gary C. Sieck ◽  
Thomas A. White ◽  
Michael A. Thompson ◽  
Christina M. Pabelick ◽  
Mark E. Wylam ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Critical Role ◽  
Human Airway Smooth Muscle ◽  
Cd38 Expression ◽  
Adp Ribosyl Cyclase ◽  
Cyclic Adp Ribose ◽  
Intracellular Ca ◽  
Interfering Rna ◽  
Synthesis And Degradation

The ectoenzyme CD38 catalyzes synthesis and degradation of cyclic ADP ribose in airway smooth muscle (ASM). The proinflammatory cytokine TNFα, which enhances agonist-induced intracellular Ca2+ ([Ca2+]i) responses, has been previously shown to increases CD38 expression. In the present study, we tested the hypothesis that the effects of TNFα on CD38 expression vs. changes in [Ca2+]i regulation in ASM cells are linked. Using isolated human ASM cells, CD38 expression was either increased (transfection) or knocked down [small interfering RNA (siRNA)], and [Ca2+]i responses to sarcoplasmic reticulum depletion [i.e., store-operated Ca2+ entry (SOCE)] were evaluated in the presence vs. absence of TNFα. Results confirmed that TNFα significantly increased CD38 expression and ADP-ribosyl cyclase activity, an effect inhibited by CD38 siRNA, but unaltered by CD38 overexpression. CD38 suppression blunted, whereas overexpression enhanced, ACh-induced [Ca2+]i responses. TNFα-induced enhancement of [Ca2+]i response to agonist was blunted by CD38 suppression, but enhanced by CD38 overexpression. Finally, TNFα-induced increase in SOCE was blunted by CD38 siRNA and potentiated by CD38 overexpression. Overall, these results indicate a critical role for CD38 in TNFα-induced enhancement of [Ca2+]i in human ASM cells, and potentially to TNFα augmentation of airway responsiveness.

Regulation of sarcoplasmic reticulum Ca2+ reuptake in porcine airway smooth muscle

2008 ◽  
Vol 294 (4) ◽  
pp. L787-L796 ◽  
Author(s):  
Venkatachalem Sathish ◽  
Figen Leblebici ◽  
Sertac N. Kip ◽  
Michael A. Thompson ◽  
Christina M. Pabelick ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Airway Smooth Muscle ◽  
Small Interfering Rna ◽  
Regulatory Protein ◽  
Plasmic Reticulum ◽  
Intracellular Ca ◽  
Subsequent Exposure ◽  
Interfering Rna ◽  
Serca Inhibition

Regulation of intracellular Ca2+ concentration ([Ca2+]i) in airway smooth muscle (ASM) during agonist stimulation involves sarcoplasmic reticulum (SR) Ca2+ release and reuptake. The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is key to replenishment of SR Ca2+ stores. We examined regulation of SERCA in porcine ASM: our hypothesis was that the regulatory protein phospholamban (PLN) and the calmodulin (CaM)-CaM kinase (CaMKII) pathway (both of which are known to regulate SERCA in cardiac muscle) play a role. In porcine ASM microsomes, we examined the expression and extent of PLN phosphorylation after pharmacological inhibition of CaM (with W-7) vs. CaMKII (with KN-62/KN-93) and found that PLN is phosphorylated by CaMKII. In parallel experiments using enzymatically dissociated single ASM cells loaded with the Ca2+ indicator fluo 3 and imaged using fluorescence microscopy, we measured the effects of PLN small interfering RNA, W-7, and KN-62 on [Ca2+]i responses to ACh and direct SR stimulation. PLN small interfering RNA slowed the rate of fall of [Ca2+]i transients to 1 μM ACh, as did W-7 and KN-62. The two inhibitors additionally slowed reuptake in the absence of PLN. In other cells, preexposure to W-7 or KN-62 did not prevent initiation of ACh-induced [Ca2+]i oscillations (which were previously shown to result from repetitive SR Ca2+ release/reuptake). However, when ACh-induced [Ca2+]i oscillations reached steady state, subsequent exposure to W7 or KN-62 decreased oscillation frequency and amplitude and slowed the fall time of [Ca2+]i transients, suggesting SERCA inhibition. Exposure to W-7 completely abolished ongoing ACh-induced [Ca2+]i oscillations in some cells. Preexposure to W-7 or KN-62 did not affect caffeine-induced SR Ca2+ release, indicating that ryanodine receptor channels were not directly inhibited. These data indicate that, in porcine ASM, the CaM-CaMKII pathway regulates SR Ca2+ reuptake, potentially through altered PLN phosphorylation.

The reverse mode of the Na+/Ca2+ exchanger provides a source of Ca2+ for store refilling following agonist-induced Ca2+ mobilization

2007 ◽  
Vol 292 (2) ◽  
pp. L438-L447 ◽  
Author(s):  
Simon Hirota ◽  
Evi Pertens ◽  
Luke J. Janssen
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Airway Smooth Muscle ◽  
Extracellular Domain ◽  
Selective Inhibitor ◽  
Cation Channels ◽  
Reverse Mode ◽  
Intracellular Ca

Agonist-induced contraction of airway smooth muscle (ASM) can be triggered by an elevation in the intracellular Ca2+ concentration, primarily through the release of Ca2+ from the sarcoplasmic reticulum (SR). The refilling of the SR is integral for subsequent contractions. It has been suggested that Ca2+ entry via store-operated cation (SOC) and receptor-operated cation channels may facilitate refilling of the SR. Indeed, depletion of the SR activates substantial inward SOC currents in ASM that are composed of both Ca2+ and Na+. Accumulation of Na+ within the cell may regulate Ca2+ handling in ASM by forcing the Na+/Ca2+ exchanger (NCX) into the reverse mode, leading to the influx of Ca2+ from the extracellular domain. Since depletion of the SR activates substantial inward Na+ current, it is conceivable that the reverse mode of the NCX may contribute to the intracellular Ca2+ pool from which the SR is refilled. Indeed, successive contractions of bovine ASM, evoked by various agonists (ACh, histamine, 5-HT, caffeine) were significantly reduced upon removal of extracellular Na+; whereas contractions evoked by KCl were unchanged by Na+ depletion. Ouabain, a selective inhibitor of the Na+/K+ pump, had no effect on the reductions observed under normal and zero-Na+ conditions. KB-R7943, a selective inhibitor of the reverse mode of the NCX, significantly reduced successive contractions induced by all agonists without altering KCl responses. Furthermore, KB-R7943 abolished successive caffeine-induced Ca2+ transients in single ASM cells. Together, these data suggest a role for the reverse mode of the NCX in refilling the SR in ASM following Ca2+ mobilization.

Intracellular Cl− fluxes play a novel role in Ca2+ handling in airway smooth muscle

2006 ◽  
Vol 290 (6) ◽  
pp. L1146-L1153 ◽  
Author(s):  
Simon Hirota ◽  
Nancy Trimble ◽  
Evi Pertens ◽  
Luke J. Janssen
Keyword(s):  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Benzoic Acid ◽  
Airway Smooth Muscle ◽  
Channel Blocker ◽  
Negative Charge ◽  
Ryanodine Receptors ◽  
Inositol 1,4,5 Trisphosphate ◽  
Intracellular Ca ◽  
Uptake And Release

Intracellular Ca2+ is actively sequestered into the sarcoplasmic reticulum (SR), whereas the release of Ca2+ from the SR can be triggered by activation of the inositol 1,4,5-trisphosphate and ryanodine receptors. Uptake and release of Ca2+ across the SR membrane are electrogenic processes; accumulation of positive or negative charge across the SR membrane could electrostatically hinder the movement of Ca2+ into or out of the SR, respectively. We hypothesized that the movement of intracellular Cl− (Cl[Formula: see text]) across the SR membrane neutralizes the accumulation of charge that accompanies uptake and release of Ca2+. Thus inhibition of SR Cl− fluxes will reduce Ca2+ sequestration and agonist-induced release. The Cl− channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB; 10−4 M), previously shown to inhibit SR Cl− channels, significantly reduced the magnitude of successive acetylcholine-induced contractions of airway smooth muscle (ASM), suggesting a “run down” of sequestered Ca2+ within the SR. Niflumic acid (10−4 M), a structurally different Cl− channel blocker, had no such effect. Furthermore, NPPB significantly reduced caffeine-induced contraction and increases in intracellular Ca2+ concentration ([Ca2+]i). Depletion of Cl[Formula: see text], accomplished by bathing ASM strips in Cl−-free buffer, significantly reduced the magnitude of successive acetylcholine-induced contractions. In addition, Cl− depletion significantly reduced caffeine-induced increases in [Ca2+]i. Together these data suggest a novel role for Cl[Formula: see text] fluxes in Ca2+ handling in smooth muscle. Because the release of sequestered Ca2+ is the predominate source of Ca2+ for contraction of ASM, targeting Cl[Formula: see text] fluxes may prove useful in the control of ASM hyperresponsiveness associated with asthma.

scholarly journals Estrogens modulate intracellular Ca 2+ in human airway smooth muscle

2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Elizabeth A Townsend ◽  
Michael A Thompson ◽  
Christina M Pabelick ◽  
YS Prakash
Keyword(s):  
Smooth Muscle ◽  
Airway Smooth Muscle ◽  
Human Airway Smooth Muscle ◽  
Human Airway ◽  
Intracellular Ca

scholarly journals Expression and coupling of neurokinin receptor subtypes to inositol phosphate and calcium signaling pathways in human airway smooth muscle cells

2008 ◽  
Vol 294 (3) ◽  
pp. L523-L534 ◽  
Author(s):  
Kentaro Mizuta ◽  
George Gallos ◽  
Defen Zhu ◽  
Fumiko Mizuta ◽  
Farida Goubaeva ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Substance P ◽  
Calcium Signaling ◽  
Airway Smooth Muscle ◽  
Inositol Phosphate ◽  
Nerve Fibers ◽  
Neurokinin A ◽  
Human Airway Smooth Muscle ◽  
Human Airway ◽  
Intracellular Ca

Neuropeptide tachykinins (substance P, neurokinin A, and neurokinin B) are present in peripheral terminals of sensory nerve fibers within the respiratory tract and cause airway contractile responses and hyperresponsiveness in humans and most mammalian species. Three subtypes of neurokinin receptors (NK1R, NK2R, and NK3R) classically couple to Gq protein-mediated inositol 1,4,5-trisphosphate (IP3) synthesis and liberation of intracellular Ca2+, which initiates contraction, but their expression and calcium signaling mechanisms are incompletely understood in airway smooth muscle. All three subtypes were identified in native and cultured human airway smooth muscle (HASM) and were subsequently overexpressed in HASM cells using a human immunodeficiency virus-1-based lentivirus transduction system. Specific NKR agonists {NK1R, [Sar9,Met(O2)11]-substance P; NK2R, [β-Ala8]-neurokinin A(4–10); NK3R, senktide} stimulated inositol phosphate synthesis and increased intracellular Ca2+ concentration ([Ca2+]i) in native HASM cells and in HASM cells transfected with each NKR subtype. These effects were blocked by NKR-selective antagonists (NK1R, L-732138; NK2R, GR-159897; NK3R, SB-222200). The initial transient and sustained phases of increased [Ca2+]i were predominantly inhibited by the IP3 receptor antagonist 2-aminoethoxydiphenyl borate (2-APB) or the store-operated Ca2+ channel antagonist SKF-96365, respectively. These results show that all three subtypes of NKRs are expressed in native HASM cells and that IP3 levels are the primary mediators of NKR-stimulated initial [Ca2+]i increases, whereas store-operated Ca2+ channels mediate the sustained phase of the [Ca2+]i increase.

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