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Navarro-Becerra JA, Caballero-Robledo GA, Franco-Urquijo CA, Ríos A, Escalante B. Functional Activity and Endothelial-Lining Integrity of Ex Vivo Arteries Exposed to Ultrasound-Mediated Microbubble Destruction. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2335-2348. [PMID: 32553691 DOI: 10.1016/j.ultrasmedbio.2020.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Ultrasound-mediated microbubble destruction (UMMD) is a promising strategy to improve local drug delivery in specific tissues. However, acoustic cavitation can lead to harmful bioeffects in endothelial cells. We investigated the side effects of UMMD treatment on vascular function (contraction and relaxation) and endothelium integrity of ex vivo Wistar rat arteries. We used an isolated organ system to evaluate vascular responses and confocal microscopy to quantify the integrity and viability of endothelial cells. The arteries were exposed for 1-3 min to ultrasound at a 100 Hz pulse-repetition frequency, 0.5 MPa acoustic pressure, 50% duty cycle and 1%-5% v/v microbubbles. The vascular contractile response was not affected. The acetylcholine-dependent maximal relaxation response was reduced from 78% (control) to 60% after 3 min of ultrasound exposure. In arteries treated simultaneously with 1 min of ultrasound exposure and 1%, 2%, 3% or 5% microbubble concentration, vascular relaxation was reduced by 19%, 58%, 80% or 93%, respectively, compared with the control arteries. Fluorescent labeling revealed that apoptotic death, detachment of endothelial cells and reduced nitric oxide synthase phosphorylation are involved in relaxation impairment. We demonstrated that UMMD can be a safe technology if the correct ultrasound and microbubble parameters are applied. Furthermore, we found that tissue-function evaluation combined with cellular analysis can be useful to study ultrasound-microbubble-tissue interactions in the optimization of targeted endothelial drug delivery.
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Affiliation(s)
| | | | | | - Amelia Ríos
- Centro de Investigación y de Estudios Avanzados del IPN, Unidad-Monterrey, Apodaca, México
| | - Bruno Escalante
- Centro de Investigación y de Estudios Avanzados del IPN, Unidad-Monterrey, Apodaca, México; Universidad de Monterrey, San Pedro Garza García, México
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Usui-Kawanishi F, Takahashi M, Sakai H, Suto W, Kai Y, Chiba Y, Hiraishi K, Kurahara LH, Hori M, Inoue R. Implications of immune-inflammatory responses in smooth muscle dysfunction and disease. J Smooth Muscle Res 2020; 55:81-107. [PMID: 32023567 PMCID: PMC6997890 DOI: 10.1540/jsmr.55.81] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In the past few decades, solid evidence has been accumulated for the pivotal significance
of immunoinflammatory processes in the initiation, progression, and exacerbation of many
diseases and disorders. This groundbreaking view came from original works by Ross who
first described that excessive inflammatory-fibroproliferative response to various forms
of insult to the endothelium and smooth muscle of the artery wall is essential for the
pathogenesis of atherosclerosis (Ross, Nature 1993; 362(6423): 801–9). It is now widely
recognized that both innate and adaptive immune reactions are avidly involved in the
inflammation-related remodeling of many tissues and organs. When this state persists,
irreversible fibrogenic changes would occur often culminating in fatal insufficiencies of
many vital parenchymal organs such as liver, lung, heart, kidney and intestines. Thus,
inflammatory diseases are becoming the common life-threatening risk for and urgent concern
about the public health in developed countries (Wynn et al., Nature Medicine 2012; 18(7):
1028–40). Considering this timeliness, we organized a special symposium entitled
“Implications of immune/inflammatory responses in smooth muscle dysfunction and disease”
in the 58th annual meeting of the Japan Society of Smooth Muscle Research. This symposium
report will provide detailed synopses of topics presented in this symposium; (1) the role
of inflammasome in atherosclerosis and abdominal aortic aneurysms by Fumitake
Usui-Kawanishi and Masafumi Takahashi; (2) Mechanisms underlying the pathogenesis of
hyper-contractility of bronchial smooth muscle in allergic asthma by Hiroyasu Sakai,
Wataru Suto, Yuki Kai and Yoshihiko Chiba; (3) Vascular remodeling in pulmonary arterial
hypertension by Keizo Hiraishi, Lin Hai Kurahara and Ryuji Inoue.
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Affiliation(s)
- Fumitake Usui-Kawanishi
- Division of Biopharmaceutical Engineering, Department of Pharmaceutical Engineering, Toyoma Prefectural University, 5180 Kurokawa, Imizu-shi, Toyama 939-0398, Japan.,Division of Inflammation Research, Center of Molecular Medicine, Jichi Medical University, 3311-159 Yakushiji, Shimono-shi, Tochigi 329-0498, Japan
| | - Masafumi Takahashi
- Division of Inflammation Research, Center of Molecular Medicine, Jichi Medical University, 3311-159 Yakushiji, Shimono-shi, Tochigi 329-0498, Japan
| | - Hiroyasu Sakai
- Department of Analytical Pathophysiology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Wataru Suto
- Department of Physiology and Molecular Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Yuki Kai
- Department of Analytical Pathophysiology, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Yoshihiko Chiba
- Department of Physiology and Molecular Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Keizo Hiraishi
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Lin Hai Kurahara
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.,Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, 1750-1 Ido, Miki-machi, Kida-gun, Kagawa 761-0793, Japan
| | - Masatoshi Hori
- Department of Veterinary Pharmacology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
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Kai Y, Motegi M, Suzuki Y, Takeuchi H, Harada Y, Sato F, Chiba Y, Kamei J, Sakai H. Up-regulation of Rac1 in the bronchial smooth muscle of murine experimental asthma. Basic Clin Pharmacol Toxicol 2019; 125:8-15. [PMID: 30697954 DOI: 10.1111/bcpt.13204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/16/2019] [Indexed: 01/19/2023]
Abstract
There has been considerable research on the involvement of RhoA/Rho kinase signalling in smooth muscle contractions. However, only a few reports have addressed the specific role of Rac1, which is a member of the Rho GTPase superfamily. Therefore, this study investigated the role of Rac1-related pathways in bronchial smooth muscle (BSM) contractions. Bronchial rings isolated from mice were suspended in an organ bath, and the isometric contractions of circular smooth muscles were monitored. The phosphorylation of myosin light chains (MLCs) was analysed by immunoblotting. The Rac1 inhibitor EHT1864 inhibited carbachol (CCh)-induced BSM contractions, although high K+ depolarization-induced BSM contractions were not significantly attenuated by EHT1864. Moreover, high K+ - and phorbol 12,13-dibutyrate (PDBu; PKC activator)-induced contractions were not attenuated by Rac1 inhibition, whereas sodium fluoride (NaF)-induced force development was inhibited by EHT1864. The gene and protein expression of Rac1 was increased in the BSM of a murine model with antigen-induced airway hyper-responsiveness (AHR). In addition, an increased force of the BSM contractions in AHR was suppressed by EHT1864 treatment, suggesting that the up-regulation of Rac1 is involved in AHR. These findings suggest that an increase in Rac1-mediated signalling is involved in the augmented contractions of BSMs in antigen-induced AHR mice.
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Affiliation(s)
- Yuki Kai
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Momoko Motegi
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Yuta Suzuki
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Hiroto Takeuchi
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Yui Harada
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Fumiaki Sato
- Department of Analytical Pathophysiology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Yoshihiko Chiba
- Department of Physiology and Molecular Sciences, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Junzo Kamei
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
| | - Hiroyasu Sakai
- Department of Biomolecular Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
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Sakai H, Suto W, Kai Y, Chiba Y. Mechanisms underlying the pathogenesis of hyper-contractility of bronchial smooth muscle in allergic asthma. J Smooth Muscle Res 2018; 53:37-47. [PMID: 28484126 PMCID: PMC5411784 DOI: 10.1540/jsmr.53.37] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Airway hyperresponsiveness (AHR) and inflammation are key pathophysiological
features of asthma. Enhanced contraction of bronchial smooth muscle (BSM) is one
of the causes of the AHR. It is thus important for development of asthma therapy
to understand the change in the contractile signaling of airway smooth muscle
cells associated with the AHR. In addition to the Ca2+-mediated
phosphorylation of myosin light chain (MLC), contractile agonists also enhance
MLC phosphorylation level, Ca2+-independently, by inactivating MLC
phosphatase (MLCP), called Ca2+ sensitization of contraction, in
smooth muscle cells including airways. To date, involvements of RhoA/ROCKs and
PKC/Ppp1r14a (also called as CPI-17) pathways in the Ca2+
sensitization have been identified. Our previous studies revealed that the
agonist-induced Ca2+ sensitization of contraction is markedly
augmented in BSMs of animal models of allergen-induced AHR. In BSMs of these
animal models, the expression of RhoA and CPI-17 proteins were significantly
increased, indicating that both the Ca2+ sensitizing pathways are
augmented. Interestingly, incubation of BSM cells with asthma-associated
cytokines, such as interleukin-13 (IL-13), IL-17, and tumor necrosis factor-α
(TNF-α), caused up-regulations of RhoA and CPI-17 in BSM cells of naive animals
and cultured human BSM cells. In addition to the transcription factors such as
STAT6 and NF-κB activated by these inflammatory cytokines, an involvement of
down-regulation of miR-133a, a microRNA that negatively regulates RhoA
translation, has also been suggested in the IL-13- and IL-17-induced
up-regulation of RhoA. Thus, the Ca2+ sensitizing pathways and the
cytokine-mediated signaling including microRNAs in BSMs might be potential
targets for treatment of allergic asthma, especially the AHR.
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Affiliation(s)
- Hiroyasu Sakai
- Department of Analytical Pathophysiology, Hoshi University
| | - Wataru Suto
- Department of Physiology and Molecular Sciences, Hoshi University
| | - Yuki Kai
- Department of Analytical Pathophysiology, Hoshi University
| | - Yoshihiko Chiba
- Department of Physiology and Molecular Sciences, Hoshi University
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5
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Rac1 modulates G-protein-coupled receptor-induced bronchial smooth muscle contraction. Eur J Pharmacol 2018; 818:74-83. [DOI: 10.1016/j.ejphar.2017.10.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/17/2017] [Accepted: 10/17/2017] [Indexed: 01/15/2023]
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Eddinger TJ. Smooth muscle-protein translocation and tissue function. Anat Rec (Hoboken) 2015; 297:1734-46. [PMID: 25125185 DOI: 10.1002/ar.22970] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 03/18/2014] [Accepted: 03/18/2014] [Indexed: 01/25/2023]
Abstract
Smooth muscle (SM) tissue is a complex organization of multiple cell types and is regulated by numerous signaling molecules (neurotransmitters, hormones, cytokines, etc.). SM contractile function can be regulated via expression and distribution of the contractile and cytoskeletal proteins, and activation of any of the second messenger pathways that regulate them. Spatial-temporal changes in the contractile, cytoskeletal or regulatory components of SM cells (SMCs) have been proposed to alter SM contractile activity. Ca(2+) sensitization/desensitization can occur as a result of changes at any of these levels, and specific pathways have been identified at all of these levels. Understanding when and how proteins can translocate within the cytoplasm, or to-and-from the plasmalemma and the cytoplasm to alter contractile activity is critical. Numerous studies have reported translocation of proteins associated with the adherens junction and G protein-coupled receptor activation pathways in isolated SMC systems. Specific examples of translocation of vinculin to and from the adherens junction and protein kinase C (PKC) and 17 kDa PKC-potentiated inhibitor of myosin light chain phosphatase (CPI-17) to and from the plasmalemma in isolated SMC systems but not in intact SM tissues are discussed. Using both isolated SMC systems and SM tissues in parallel to pursue these studies will advance our understanding of both the role and mechanism of these pathways as well as their possible significance for Ca(2+) sensitization in intact SM tissues and organ systems.
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Affiliation(s)
- Thomas J Eddinger
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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Zhang Y, Hermanson ME, Eddinger TJ. Tonic and phasic smooth muscle contraction is not regulated by the PKCα - CPI-17 pathway in swine stomach antrum and fundus. PLoS One 2013; 8:e74608. [PMID: 24058600 PMCID: PMC3776813 DOI: 10.1371/journal.pone.0074608] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 08/04/2013] [Indexed: 01/31/2023] Open
Abstract
Regulation of myosin light chain phosphatase (MLCP) via protein kinase C (PKC) and the 17 kDa PKC-potentiated inhibitor of myosin light chain phosphatase (CPI-17) has been reported as a Ca2+ sensitization signaling pathway in smooth muscle (SM), and thus may be involved in tonic vs. phasic contractions. This study examined the protein expression and spatial-temporal distribution of PKCα and CPI-17 in intact SM tissues. KCl or carbachol (CCh) stimulation of tonic stomach fundus SM generates a sustained contraction while the phasic stomach antrum generates a transient contraction. In addition, the tonic fundus generates greater relative force than phasic antrum with 1 µM phorbol 12, 13-dibutyrate (PDBu) stimulation which is reported to activate the PKCα – CPI-17 pathway. Western blot analyses demonstrated that this contractile difference was not caused by a difference in the protein expression of PKCα or CPI-17 between these two tissues. Immunohistochemical results show that the distribution of PKCα in the longitudinal and circular layers of the fundus and antrum do not differ, being predominantly localized near the SM cell plasma membrane. Stimulation of either tissue with 1 µM PDBu or 1 µM CCh does not alter this peripheral PKCα distribution. There are no differences between these two tissues for the CPI-17 distribution, but unlike the PKCα distribution, CPI-17 appears to be diffusely distributed throughout the cytoplasm under relaxed tissue conditions but shifts to a primarily peripheral distribution at the plasma membrane with stimulation of the tissues with 1 µM PDBu or 1 µM CCh. Results from double labeling show that neither PKCα nor CPI-17 co-localize at the adherens junction (vinculin/talin) at the membrane but they do co-localize with each other and with caveoli (caveolin) at the membrane. This lack of difference suggests that the PKCα - CPI-17 pathway is not responsible for the tonic vs. phasic contractions observed in stomach fundus and antrum.
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Affiliation(s)
- Yu Zhang
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America
| | - Meghan E. Hermanson
- Department of Biology, Bradley University, Peoria, Illinois, United States of America
| | - Thomas J. Eddinger
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Chiba Y, Tanabe M, Sakai H, Kimura S, Misawa M. A functional interaction between CPI-17 and RACK1 proteins in bronchial smooth muscle cells. Biochem Biophys Res Commun 2010; 401:487-90. [PMID: 20875397 DOI: 10.1016/j.bbrc.2010.09.086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Accepted: 09/18/2010] [Indexed: 10/19/2022]
Abstract
CPI-17 is a phosphorylation-dependent inhibitor of smooth muscle myosin light chain. Using yeast two-hybrid system, we have identified the receptor for activated C kinase 1 (RACK1) as a novel interaction partner of CPI-17. The direct interaction and co-localization of CPI-17 with RACK1 were confirmed by immunoprecipitation and confocal microscopy analysis, respectively. An in vitro assay system using recombinant/purified proteins revealed that the PKC-mediated phosphorylation of CPI-17 was augmented in the presence of RACK1. These results suggest that RACK1 may play a role in PKC/CPI-17 signaling pathway.
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Affiliation(s)
- Yoshihiko Chiba
- Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan.
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Siegling-Vlitakis C, Martens H, Lüdtke R. In VitroExamination of Potentized Atropine Sulfate Dilutions on the Contractility of the Isolated Rat Ileum. J Altern Complement Med 2009; 15:1121-6. [DOI: 10.1089/acm.2008.0614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Shiraki A, Kume H, Oguma T, Makino Y, Ito S, Shimokata K, Honjo H, Kamiya K. Role of Ca2+ mobilization and Ca2+ sensitization in 8-iso-PGF 2 alpha-induced contraction in airway smooth muscle. Clin Exp Allergy 2008; 39:236-45. [PMID: 19134015 DOI: 10.1111/j.1365-2222.2008.03164.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Isoprostanes are prostaglandin (PG)-like compounds synthesized by oxidative stress, not by cyclooxygenase, and increase in bronchoalveolar lavage fluid of patients with asthma. The airway inflammation implicated in this disease may be amplified by oxidants. Although isoprostanes are useful biomarkers for oxidative stress, the action of these agents on airways has not been fully elucidated. OBJECTIVE This study was designed to determine the intracellular mechanisms underlying the effects of oxidative stress on airway smooth muscle, focused on Ca(2+) signalling pathways involved in the effect of 8-iso-PGF(2 alpha). METHODS Using simultaneous recording of isometric tension and F(340)/F(380) (an indicator of intracellular concentrations of Ca(2+), [Ca(2+)]i, we examined the correlation between tension and [Ca(2+)]i in response to 8-iso-PGF(2 alpha) in the fura-2 loaded tracheal smooth muscle. RESULTS Augmented tension and F(340)/F(380) by 8-iso-PGF(2 alpha) were attenuated by ICI-192605, an antagonist of thromboxane A(2) receptors (TP receptors). Moreover, D609, an antagonist of phosphatidylcholine-specific phospholipase C, markedly reduced both the tension and F(340)/F(380) induced by 8-iso-PGF(2 alpha), whereas U73122, an antagonist of phosphatidylinositol-specific phospholipase C, modestly inhibited them by 8-iso-PGF(2 alpha). SKF96365, a non-selective antagonist of Ca(2+) channels, markedly reduced both tension and F(340)/F(380) by 8-iso-PGF(2 alpha). However, diltiazem and verapamil, voltage-dependent Ca(2+) channel inhibitors, modestly attenuated tension although their reduction of F(340)/F(380) was not different from that by SKF96365. Y-27632, an inhibitor of Rho-kinase, significantly attenuated contraction induced by 8-iso-PGF(2 alpha) without reducing F(340)/F(380), whereas GF109203X and Go6983, protein kinase C inhibitors, did not markedly antagonize them although reducing F(340)/F(380) with a potency similar to Y-27632. CONCLUSION 8-iso-PGF(2 alpha) causes airway smooth muscle contraction via activation of TP receptors. Ca(2+) mobilization by SKF96365- and D609-sensitive Ca(2+) influx and Ca(2+) sensitization by Rho-kinase contribute to the intracellular mechanisms underlying the action of 8-iso-PGF(2 alpha). Rho-kinase may be a therapeutic target for the physiologic abnormalities induced by oxidative stress in airways.
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Affiliation(s)
- A Shiraki
- Department of Respiratory Medicine, Nagoya University Graduate School of Medicine, Nagoya University, Nagoya, Japan
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Goto K, Chiba Y, Sakai H, Misawa M. Glucocorticoids inhibited airway hyperresponsiveness through downregulation of CPI-17 in bronchial smooth muscle. Eur J Pharmacol 2008; 591:231-6. [PMID: 18577381 DOI: 10.1016/j.ejphar.2008.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2007] [Revised: 05/26/2008] [Accepted: 06/05/2008] [Indexed: 11/15/2022]
Abstract
Glucocorticoids are the most effective anti-inflammatory treatment for asthma, and inhaled corticosteroids are the most effective long-term control therapy for persistent asthma. In the present study, to determine the mechanism of the inhibitory effect of glucocorticoids on airway hyperresponsiveness, the effects of glucocorticoids on the expression and activation of PKC-potentiated protein phosphatase 1 inhibitory protein of 17 kDa (CPI-17) were examined in bronchial smooth muscles of antigen-induced airway hyperresponsive rats. Repeated antigen inhalation to animals sensitized with DNP-Ascaris antigen caused a marked bronchial smooth muscle hyperresponsiveness to acetylcholine, accompanied by upregulation and acetylcholine-induced activation of CPI-17 to result in an increase in myosin light chain (MLC) phosphorylation. Treatment with glucocorticoids (prednisolone or beclomethasone, 10 mg/kg, i.p., respectively) significantly inhibited the airway hyperresponsiveness, and markedly reduced both the protein and mRNA levels of CPI-17 in bronchial smooth muscle. The acetylcholine-induced activation of CPI-17, i.e., phosphorylation of CPI-17, was also significantly inhibited by glucocorticoids. Glucocorticoids also prevented the augmented acetylcholine-induced MLC phosphorylation observed in the airway hyperresponsive rats. Therefore, glucocorticoids might inhibit the airway hyperresponsiveness through the inhibition of overexpression and activation of CPI-17.
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Affiliation(s)
- Kumiko Goto
- Department of Pharmacology, School of Pharmacy, Hoshi University, Tokyo, Japan
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