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Selivanova EK, Gaynullina DK, Tarasova OS. Thyroxine Induces Acute Relaxation of Rat Skeletal Muscle Arteries via Integrin αvβ3, ERK1/2 and Integrin-Linked Kinase. Front Physiol 2021; 12:726354. [PMID: 34594239 PMCID: PMC8477044 DOI: 10.3389/fphys.2021.726354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/23/2021] [Indexed: 11/17/2022] Open
Abstract
Aim: Hyperthyroidism is associated with a decreased peripheral vascular resistance, which could be caused by the vasodilator genomic or non-genomic effects of thyroid hormones (TH). Non-genomic, or acute, effects develop within several minutes and involve a wide tissue-specific spectrum of molecular pathways poorly studied in vasculature. We aimed to investigate the mechanisms of acute effects of TH on rat skeletal muscle arteries. Methods: Sural arteries from male Wistar rats were used for isometric force recording (wire myography) and phosphorylated protein content measurement (Western blotting). Results: Both triiodothyronine (T3) and thyroxine (T4) reduced contractile response of sural arteries to α1-adrenoceptor agonist methoxamine. The effect of T4 was more prominent than T3 and not affected by iopanoic acid, an inhibitor of deiodinase 2. Endothelium denudation abolished the effect of T3, but not T4. Integrin αvβ3 inhibitor tetrac abolished the effect of T4 in endothelium-denuded arteries. T4 weakened methoxamine-induced elevation of phospho-MLC2 (Ser19) content in arterial samples. The effect of T4 in endothelium-denuded arteries was abolished by inhibiting ERK1/2 activation with U0126 as well as by ILK inhibitor Cpd22 but persisted in the presence of Src- or Rho-kinase inhibitors (PP2 and Y27632, respectively). Conclusion: Acute non-genomic relaxation of sural arteries induced by T3 is endothelium-dependent and that induced by T4 is endothelium-independent. The effect of T4 on α1-adrenergic contraction is stronger compared to T3 and involves the suppression of extracellular matrix signaling via integrin αvβ3, ERK1/2 and ILK with subsequent decrease of MLC2 (Ser19) phosphorylation.
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Affiliation(s)
- Ekaterina K Selivanova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Dina K Gaynullina
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.,Department of Physiology, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Olga S Tarasova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.,Laboratory of Exercise Physiology, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
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Pang Y, Thomas P. Progesterone induces relaxation of human umbilical cord vascular smooth muscle cells through mPRα (PAQR7). Mol Cell Endocrinol 2018; 474:20-34. [PMID: 29428395 DOI: 10.1016/j.mce.2018.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 02/07/2023]
Abstract
Progesterone effects on vascular smooth muscle cell (VSMC) relaxation and the mechanism were investigated in cultured human umbilical vein VSMCs. Membrane progesterone receptors mPRα, mPRβ, and mPRγ were highly expressed in VSMCs, whereas nuclear progesterone receptor (nPR) had low expression. Progesterone (20 nM) and 02-0 (mPR-selective agonist), but not R5020 (nPR agonist), induced muscle relaxation in both a VSMC collagen gel disk contraction assay and an endothelium-denuded human umbilical artery ring tension assay. Progesterone and 02-0 increased ERK and Akt phosphorylation and decreased cAMP levels. These effects were blocked by preincubation with pertussis toxin. Progestin-induced muscle relaxation was blocked by pretreatment with mPRα, but not nPR, siRNAs, and by co-treatment with 8-Br-cAMP, AZD6244 (MAP kinase inhibitor), and wortmannin (PI3K inhibitor). Progestins reduced myosin light chain phosphorylation which was blocked with AZD6244 and wortmannin. These results demonstrate progesterone directly relaxes human VSMCs through mPRα/Gi and MAP kinase/ERK-, Akt/PI3K-, and cAMP-dependent pathways.
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Affiliation(s)
- Yefei Pang
- Marine Science Institute, University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX, 78373, USA.
| | - Peter Thomas
- Marine Science Institute, University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX, 78373, USA.
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Koziol-White CJ, Yoo EJ, Cao G, Zhang J, Papanikolaou E, Pushkarsky I, Andrews A, Himes BE, Damoiseaux RD, Liggett SB, Di Carlo D, Kurten RC, Panettieri RA. Inhibition of PI3K promotes dilation of human small airways in a rho kinase-dependent manner. Br J Pharmacol 2016; 173:2726-38. [PMID: 27352269 PMCID: PMC4995285 DOI: 10.1111/bph.13542] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 05/27/2016] [Accepted: 06/05/2016] [Indexed: 12/03/2022] Open
Abstract
Background and Purpose Asthma manifests as a heterogeneous syndrome characterized by airway obstruction, inflammation and hyperresponsiveness (AHR). Although the molecular mechanisms remain unclear, activation of specific PI3K isoforms mediate inflammation and AHR. We aimed to determine whether inhibition of PI3Kδ evokes dilation of airways and to elucidate potential mechanisms. Experimental Approach Human precision cut lung slices from non‐asthma donors and primary human airway smooth muscle (HASM) cells from both non‐asthma and asthma donors were utilized. Phosphorylation of Akt, myosin phosphatase target subunit 1 (MYPT1) and myosin light chain (MLC) were assessed in HASM cells following either PI3K inhibitor or siRNA treatment. HASM relaxation was assessed by micro‐pattern deformation. Reversal of constriction of airways was assessed following stimulation with PI3K or ROCK inhibitors. Key Results Soluble inhibitors or PI3Kδ knockdown reversed carbachol‐induced constriction of human airways, relaxed agonist‐contracted HASM and inhibited pAkt, pMYPT1 and pMLC in HASM. Similarly, inhibition of Rho kinase also dilated human PCLS airways and suppressed pMYPT1 and pMLC. Baseline pMYPT1 was significantly elevated in HASM cells derived from asthma donors in comparison with non‐asthma donors. After desensitization of the β2‐adrenoceptors, a PI3Kδ inhibitor remained an effective dilator. In the presence of IL‐13, dilation by a β agonist, but not PI3K inhibitor, was attenuated. Conclusion and Implications PI3Kδ inhibitors act as dilators of human small airways. Taken together, these findings provide alternative approaches to the clinical management of airway obstruction in asthma.
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Affiliation(s)
- Cynthia J Koziol-White
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Edwin J Yoo
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Gaoyuan Cao
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Jie Zhang
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Eleni Papanikolaou
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
| | - Ivan Pushkarsky
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Adam Andrews
- Department of Bioengineering, University of California, Los Angeles, CA, USA
| | - Blanca E Himes
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert D Damoiseaux
- California NanoSystems Institute, University of California, Los Angeles, CA, USA.,Department of Molecular and Medicinal Pharmacology, University of California, Los Angeles, CA, USA
| | | | - Dino Di Carlo
- Department of Bioengineering, University of California, Los Angeles, CA, USA.,California NanoSystems Institute, University of California, Los Angeles, CA, USA.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA, USA
| | - Richard C Kurten
- Arkansas Children's Hospital Research Institute and Department of Physiology & Biophysics, University of Arkansas Medical Sciences, Little Rock, AR, USA
| | - Reynold A Panettieri
- Rutgers Institute for Translational Medicine and Science, Child Health Institute, Rutgers University, New Brunswick, NJ, USA
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Hu G, Li X, Zhang S, Wang X. Association of rat thoracic aorta dilatation by astragaloside IV with the generation of endothelium-derived hyperpolarizing factors and nitric oxide, and the blockade of Ca 2+ channels. Biomed Rep 2016; 5:27-34. [PMID: 27347401 PMCID: PMC4907089 DOI: 10.3892/br.2016.680] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 04/11/2016] [Indexed: 01/18/2023] Open
Abstract
The aim of the present study was to elucidate the roles of endothelium-derived hyperpolarizing factors (EDHFs) and nitric oxide (NO) in mediating the vasodilatation response to astragaloside IV and the effects of astragaloside IV on voltage-dependent Ca2+ channels and receptor-operated Ca2+ channels in rat thoracic aortic rings precontracted with potassium chloride (KCl; 60 mM) or phenylephrine (PHE; 1 µM). The results showed that astragaloside IV (1×10−4-3×10−1 g/l) concentration-dependently relaxed the contraction induced by KCl (10–90 mM) or PHE (1×10−9-3×10−5 µM) and inhibited concentration-contraction curves for the two vasoconstrictors in the aortic rings. Preincubation with Nω-nitro-L-arginine methyl ester (L-NAME, 100 µM) significantly attenuated astragaloside IV-induced relaxation in the endothelium-intact and -denuded arterial rings precontracted with PHE. Astragaloside IV, following preincubation with L-NAME (100 µM) plus indomethacin (10 µM), exerted vasodilatation, which was depressed by tetraethtylamine (1 mM) and propargylglycine (100 µM), but not by carbenoxolone (10 µM), catalase (500 U/ml) or proadifen hydrochloride (10 µM). The action mode of astragaloside IV was evident in comparison to nifedipine. Inhibition of PHE-induced contraction by astragaloside IV (100 mg/l) was more potent compared to inhibition of KCl-induced contraction, while inhibition of KCl-induced contraction by nifedipine (100 mg/l) was more potent compared to inhibition of PHE-induced contraction by nifedipine (100 mg/l). In addition, the combination of astragaloside IV and nifedipine exhibited synergistic and additive inhibitory effects on contraction evoked by KCl, which was similar to PHE. In conclusion, astragaloside IV, as a Ca2+ antagonist, relaxes the vessels through the blockade of superior receptor-operated Ca2+ and inferior voltage-dependent Ca2+ channels, which modulate NO from vascular endothelial cells and vascular smooth muscle cells, and EDHFs including K+ and hydrogen sulfide.
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Affiliation(s)
- Guanying Hu
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Xixiong Li
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Sanyin Zhang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
| | - Xin Wang
- Basic Medical College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, P.R. China
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Kaufmann J, Martinka P, Moede O, Sendeski M, Steege A, Fähling M, Hultström M, Gaestel M, Moraes-Silva IC, Nikitina T, Liu ZZ, Zavaritskaya O, Patzak A. Noradrenaline enhances angiotensin II responses via p38 MAPK activation after hypoxia/re-oxygenation in renal interlobar arteries. Acta Physiol (Oxf) 2015; 213:920-32. [PMID: 25594617 DOI: 10.1111/apha.12457] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Revised: 03/14/2014] [Accepted: 01/11/2015] [Indexed: 11/29/2022]
Abstract
AIM Hypoxia and sympathetic activation are main factors in the pathogenesis of acute kidney injury (AKI). We tested the hypothesis that noradrenaline (NE) in combination with hypoxia aggravates the vasoreactivity of renal arteries after hypoxia/re-oxygenation (H/R). We tested the role of adrenergic receptors and p38 MAPK using an in vitro H/R protocol. METHODS Mouse interlobar arteries (ILA) and afferent arterioles (AA) were investigated under isometric and isotonic conditions respectively. The in vitro protocol consisted of 60-min hypoxia and control condition, respectively, 10-min re-oxygenation followed by concentration-response curves for Ang II or endothelin. RESULTS Hypoxia reduced the response to Ang II. Hypoxia and NE (10(-9) mol L(-1) ) together increased it in ILA and AA. In ILA, NE alone influenced neither Ang II responses under control conditions nor endothelin responses after hypoxia. Prazosin or yohimbine treatment did not significantly influence the NE+hypoxia effect. The combination of prazosin and yohimbine or propranolol alone inhibited the effect of NE+hypoxia. BRL37344 (β3 receptor agonist) mimicked the NE effect. In contrast, the incubation with β3 receptor blocker did not influence the mentioned effect. Phosphorylation of p38 MAPK and MLC(20) was increased after H/R with NE and Ang II treatment. The selective p38 MAPK inhibitor SB202190 blocked the NE+hypoxia effect on the Ang II response. CONCLUSION The results suggest an interaction of NE and hypoxia in enhancing vasoreactivity, which may be important for the pathogenesis of AKI. The effect of NE+hypoxia in ILA is mediated by several adrenergic receptors and requires the p38 MAPK activation.
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Affiliation(s)
- J. Kaufmann
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - P. Martinka
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - O. Moede
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - M. Sendeski
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - A. Steege
- Department of Internal Medicine II; University Medical Center Regensburg; Regensburg Germany
| | - M. Fähling
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - M. Hultström
- Institute of Medical Cell Biology; Uppsala University; Uppsala Sweden
| | - M. Gaestel
- Institute of Biochemistry; Hannover Medical School; Hannover Germany
| | - I. C. Moraes-Silva
- Heart Institute; University of São Paulo; School of Medicine; São Paulo Brazil
| | - T. Nikitina
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - Z. Z. Liu
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - O. Zavaritskaya
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
- Cardiovascular Physiology; Centre for Biomedicine and Medical Technology Mannheim; Ruprecht-Karls-University Heidelberg; Mannheim Germany
| | - A. Patzak
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
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Liu L, Zhang J, Zhu Y, Xiao X, Peng X, Yang G, Zang J, Liu S, Li T. Beneficial effects of platelet-derived growth factor on hemorrhagic shock in rats and the underlying mechanisms. Am J Physiol Heart Circ Physiol 2014; 307:H1277-87. [PMID: 25172895 DOI: 10.1152/ajpheart.00006.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Studies have shown that local application of platelet-derived growth factor (PDGF) can be used for the treatment of acute and chronic wounds. We investigated if systemic application of PDGF has a protective effect on acute hemorrhagic shock in rats in the present study. Using hemorrhagic shock rats and isolated superior mesenteric arteries, the effects of PDGF-BB on hemodynamics, animal survival, and vascular reactivity as well as the roles of the gap junction proteins connexin (Cx)40 and Cx43, PKC, and Rho kinase were observed. PDGF-BB (1–15 μg/kg iv) significantly improved the hemodynamics and blood perfusion to vital organs (liver and kidney) as well as vascular reactivity and improved the animal survival in hemorrhagic shock rats. PDGF recovering shock-induced vascular hyporeactivity depended on the integrity of the endothelium and myoendothelial gap junction. Cx43 antisense oligodeoxynucleotide abolished these improving effects of PDGF, whereas Cx40 oligodeoxynucleotide did not. Further study indicated that PDGF increased the activity of Rho kinase and PKC as well as vascular Ca2+ sensitivity, whereas it did not interfere with the intracellular Ca2+ concentration in hypoxia-treated vascular smooth muscle cells. In conclusion, systemic application of PDGF-BB may exert beneficial effects on hemorrhagic shock, which are closely related to the improvement of vascular reactivity and hemodynamics. The improvement of PDGF-BB in vascular reactivity is vascular endothelium and myoendothelial gap junction dependent. Cx43, Rho kinase, and PKC play very important role in this process. These findings suggest that PDGF may be a potential measure to treat acute clinical critical diseases such as severe trauma, shock, and sepsis.
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MESH Headings
- Angiogenesis Inducing Agents/pharmacology
- Angiogenesis Inducing Agents/therapeutic use
- Animals
- Becaplermin
- Calcium Signaling
- Connexin 43/genetics
- Connexin 43/metabolism
- Connexins/genetics
- Connexins/metabolism
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Gap Junctions/drug effects
- Gap Junctions/metabolism
- Gap Junctions/physiology
- Hemodynamics/drug effects
- Liver Circulation
- Mesenteric Artery, Superior/cytology
- Mesenteric Artery, Superior/metabolism
- Mesenteric Artery, Superior/physiopathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Protein Kinase C/metabolism
- Proto-Oncogene Proteins c-sis/pharmacology
- Proto-Oncogene Proteins c-sis/therapeutic use
- Rats
- Rats, Wistar
- Renal Circulation
- Shock, Hemorrhagic/drug therapy
- Shock, Hemorrhagic/metabolism
- Shock, Hemorrhagic/physiopathology
- rho-Associated Kinases/metabolism
- Gap Junction alpha-5 Protein
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Liu L, Yang G, Zhu Y, Xu J, Zang J, Zhang J, Peng X, Lan D, Li T. Role of non-MLC20 phosphorylation pathway in the regulation of vascular reactivity during shock. J Surg Res 2014; 187:571-80. [DOI: 10.1016/j.jss.2013.10.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 10/26/2022]
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Lam M, Dey A, Lang RJ, Exintaris B. Effects of imatinib mesylate on the spontaneous activity generated by the guinea-pig prostate. BJU Int 2013; 112:E398-405. [PMID: 23879919 DOI: 10.1111/j.1464-410x.2012.11660.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
UNLABELLED What's known on the subject? and what does the study add?: Several studies have examined the functional role of tyrosine kinase receptors in the generation of spontaneous activity in various segments of the gastrointestinal and urogenital tracts through the application of its inhibitor, imatinib mesylate (Glivec®), but results are fairly inconsistent. This is the first study detailing the effects of imatinib mesylate on the spontaneous activity in the young and ageing prostate gland. As spontaneous electrical activity underlies the spontaneous rhythmic prostatic contractions that occur at rest, elucidating the mechanisms involved in the regulation of the spontaneous electrical activity and the resultant phasic contractions could conceivably lead to the identification of better targets and the development of more specific therapeutic agents to treat prostate conditions. OBJECTIVE To investigate the effect of imatinib mesylate, a tyrosine kinase receptor inhibitor, in the generation of spontaneous electrical and contractile activity in the young and ageing guinea-pig prostate. MATERIALS AND METHODS Standard tension and intracellular recording were used to measure spontaneous contractions and slow waves, respectively from the guinea-pig prostate at varying concentrations of imatinib mesylate (1-50 μm). RESULTS Imatinib mesylate (1-10 μm), did not significantly affect slow waves recorded in the prostate of both age groups but at 50 μm, the amplitude of slow waves from the ageing guinea-pig prostate was significantly reduced (P < 0.05, n = 5). In contrast, the amplitude of contractions across all concentrations in the young guinea-pig prostate was reduced to between 35% and 41% of control, while the frequency was reduced to 15.7% at 1 μm (n = 7), 49.8% at 5 μm (n = 10), 46.2% at 10 μm (n = 7) and 53.1% at 50 μm (n = 5). Similarly, imatinib mesylate attenuated the amplitude and slowed the frequency of contractions in ageing guinea-pigs to 5.15% and 3.3% at 1 μm (n = 6); 21.1% and 20.8% at 5 μm (n = 8); 58.4% and 8.8% at 10 μm (n = 11); 72.7% and 60% at 50 μm (n = 5). CONCLUSIONS A significant reduction in contractions but persistence of slow waves suggests imatinib mesylate may affect the smooth muscle contractile mechanism. Imatinib mesylate also significantly reduced contractions in the prostates of younger guinea pigs more than older ones, which is consistent with the notion that the younger guinea-pig prostate is more reliant on the tyrosine-dependent pacemaker ability of interstitial cells of Cajal-like prostatic interstitial cells.
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Affiliation(s)
- Michelle Lam
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Australia
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Endogenous cardiac troponin T modulates Ca(2+)-mediated smooth muscle contraction. Sci Rep 2012; 2:979. [PMID: 23248744 PMCID: PMC3522072 DOI: 10.1038/srep00979] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 11/20/2012] [Indexed: 02/08/2023] Open
Abstract
Mechanisms linked to actin filaments have long been thought to cooperate in smooth muscle contraction, although key molecules were unclear. We show evidence that cardiac troponin T (cTnT) substantially contributes to Ca2+-mediated contraction in a physiological range of cytosolic Ca2+ concentration ([Ca2+]i). cTnT was detected in various smooth muscles of the aorta, trachea, gut and urinary bladder, including in humans. Also, cTnT was distributed along with tropomyosin in smooth muscle cells, suggesting that these proteins are ready to cause smooth muscle contraction. In chemically permeabilised smooth muscle of cTnT+/− mice in which cTnT reduced to ~50%, the Ca2+-force relationship was shifted toward greater [Ca2+]i, indicating a sizeable contribution of cTnT to smooth muscle contraction at [Ca2+]i < 1 μM. Furthermore, addition of supplemental TnI and TnC reconstructed a troponin system to enhance contraction. The results indicated that a Tn/Tn-like system on actin-filaments cooperates together with the thick-filament pathway.
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Wang T, Kendig DM, Trappanese DM, Smolock EM, Moreland RS. Phorbol 12,13-dibutyrate-induced, protein kinase C-mediated contraction of rabbit bladder smooth muscle. Front Pharmacol 2012; 2:83. [PMID: 22232602 PMCID: PMC3249380 DOI: 10.3389/fphar.2011.00083] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 12/06/2011] [Indexed: 11/13/2022] Open
Abstract
Contraction of bladder smooth muscle is predominantly initiated by M(3) muscarinic receptor-mediated activation of the G(q/11)-phospholipase C β-protein kinase C (PKC) and the G(12/13)-RhoGEF-Rho kinase (ROCK) pathways. However, these pathways and their downstream effectors are not well understood in bladder smooth muscle. We used phorbol 12,13-dibutyrate (PDBu), and 1,2-dioctanoyl-sn-glycerol (DOG), activators of PKC, in this investigation. We were interested in dissecting the role(s) of PKC and to clarify the signaling pathways in bladder smooth muscle contraction, especially the potential cross-talk with ROCK and their downstream effectors in regulating myosin light chain phosphatase activity and force. To achieve this goal, the study was performed in the presence or absence of the PKC inhibitor bisindolylmaleimide-1 (Bis) or the ROCK inhibitor H-1152. Phosphorylation levels of Thr(38)-CPI-17 and Thr(696)/Thr(850) myosin phosphatase target subunit (MYPT1) were measured during PDBu or DOG stimulation using site specific antibodies. PDBu-induced contraction in bladder smooth muscle involved both activation of PKC and PKC-dependent activation of ROCK. CPI-17 as a major downstream effector, is phosphorylated by PKC and ROCK during PDBu and DOG stimulation. Our results suggest that Thr(696) and Thr(850)-MYPT1 phosphorylation are not involved in the regulation of a PDBu-induced contraction. The results also demonstrate that bladder smooth muscle contains a constitutively active isoform of ROCK that may play an important role in the regulation of bladder smooth muscle basal tone. Together with the results from our previous study, we developed a working model to describe the complex signaling pathways that regulate contraction of bladder smooth muscle.
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Affiliation(s)
- Tanchun Wang
- Departments of Pharmacology and Physiology, Drexel University College of Medicine Philadelphia, PA, USA
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Shen D, Li J, Lepore JJ, Anderson TJT, Sinha S, Lin AY, Cheng L, Cohen ED, Roberts JD, Dedhar S, Parmacek MS, Gerszten RE. Aortic aneurysm generation in mice with targeted deletion of integrin-linked kinase in vascular smooth muscle cells. Circ Res 2011; 109:616-28. [PMID: 21778429 DOI: 10.1161/circresaha.110.239343] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
RATIONALE Integrin-linked kinase (ILK) is located at focal adhesions and links the extracellular matrix (ECM) to the actin cytoskeleton via β1- and β3-integrins. ILK plays a role in the activation of kinases including protein kinase B/Akt and glycogen synthase kinase 3β and regulates cell proliferation, motility, and survival. OBJECTIVE To determine the function of ILK in vascular smooth muscle cells (SMCs) in vivo. METHODS AND RESULTS SM22Cre(+)Ilk(Fl/Fl) conditional mutant mice were generated in which the Ilk gene was selectively ablated in SMCs. SM22Cre(+)Ilk(Fl/Fl) conditional mutant mice survive to birth but die in the perinatal period exhibiting multiple vascular pathologies including aneurysmal dilatation of the aorta and patent ductus arteriosus (PDA). Defects in morphogenetic development of the aorta were observed as early as E12.5 in SM22Cre(+)Ilk(Fl/Fl) mutant embryos. By late gestation (E16.5 to 18.5), striking expansion of the thoracic aorta was observed in ILK mutant embryos. Histological analyses revealed that the structural organization of the arterial tunica media is severely disrupted with profound derangements in SMC morphology, cell-cell, and cell-matrix relationships, including disruption of the elastic lamellae. ILK deletion in primary aortic SMCs results in alterations of RhoA/cytoskeletal signaling transduced through aberrant localization of myocardin-related transcription factor (MRTF)-A repressing the transcription and expression of SMC genes, which are required for the maintenance of the contractile SMC phenotype. CONCLUSIONS These data identify a molecular pathway linking ILK signaling to the contractile SMC gene program. Activation of this pathway is required for morphogenetic development of the aorta and ductus arteriosus during embryonic and postnatal survival.
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Affiliation(s)
- Dongxiao Shen
- Cardiovascular Research Center, Massachusetts General Hospital East-8307, Charlestown, MA 02129, USA
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López RM, Pérez T, Castillo C, Castillo EF. Effects induced by inhibitors of the phosphatidylinositol 3-kinase/Akt and nitric oxide synthase/guanylyl cyclase pathways on the isometric contraction in rat aorta: a comparative study. Fundam Clin Pharmacol 2011; 25:313-22. [DOI: 10.1111/j.1472-8206.2010.00833.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Ruth M López
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Col. Casco de Santo Tomás, CP 11340, México, DF, México
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Smolock EM, Trappanese DM, Chang S, Wang T, Titchenell P, Moreland RS. siRNA-mediated knockdown of h-caldesmon in vascular smooth muscle. Am J Physiol Heart Circ Physiol 2009; 297:H1930-9. [PMID: 19767533 PMCID: PMC2781382 DOI: 10.1152/ajpheart.00129.2009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 09/15/2009] [Indexed: 01/13/2023]
Abstract
Smooth muscle contraction involves phosphorylation of the regulatory myosin light chain. However, this thick-filament system of regulation cannot account for all aspects of a smooth muscle contraction. An alternate site of contractile regulation may be in the thin-filament-associated proteins, in particular caldesmon. Caldesmon has been proposed to be an inhibitory protein that acts either as a brake to stop any increase in resting or basal tone, or as a modulatory protein during contraction. The goal of this study was to use short interfering RNA technology to decrease the levels of the smooth muscle-specific isoform of caldesmon in intact vascular smooth muscle tissue to determine more carefully what role(s) caldesmon has in smooth muscle regulation. Intact strips of vascular tissue depleted of caldesmon produced significant levels of shortening velocity, indicative of cross-bridge cycling, in the unstimulated tissue and exhibited lower levels of contractile force to histamine. Our results also suggest that caldesmon does not play a role in the cooperative activation of unphosphorylated cross bridges by phosphorylated cross bridges. The velocity of shortening of the constitutively active tissue and the high basal values of myosin light chain phosphorylation suggest that h-caldesmon in vivo acts as a brake against contractions due to basally phosphorylated myosin. It is also possible that phosphorylation of h-caldesmon alone in the resting state may be a mechanism to produce increases in force without stimulation and increases in calcium. Disinhibition of h-caldesmon by phosphorylation would then allow force to be developed by activated myosin in the resting state.
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Affiliation(s)
- Elaine M Smolock
- Department of Pharmacology and Physiology, Drexel University College of Medicine, 245 N. 15th St., MS #488, Philadelphia, PA 19102, USA
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14
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Wang T, Kendig DM, Smolock EM, Moreland RS. Carbachol-induced rabbit bladder smooth muscle contraction: roles of protein kinase C and Rho kinase. Am J Physiol Renal Physiol 2009; 297:F1534-42. [PMID: 19794111 DOI: 10.1152/ajprenal.00095.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Smooth muscle contraction is regulated by phosphorylation of the myosin light chain (MLC) catalyzed by MLC kinase and dephosphorylation catalyzed by MLC phosphatase. Agonist stimulation of smooth muscle results in the inhibition of MLC phosphatase activity and a net increase in MLC phosphorylation and therefore force. The two pathways believed to be primarily important for inhibition of MLC phosphatase activity are protein kinase C (PKC)-catalyzed CPI-17 phosphorylation and Rho kinase (ROCK)-catalyzed myosin phosphatase-targeting subunit (MYPT1) phosphorylation. The goal of this study was to determine the roles of PKC and ROCK and their downstream effectors in regulating MLC phosphorylation levels and force during the phasic and sustained phases of carbachol-stimulated contraction in intact bladder smooth muscle. These studies were performed in the presence and absence of the PKC inhibitor bisindolylmaleimide-1 (Bis) or the ROCK inhibitor H-1152. Phosphorylation levels of Thr(38)-CPI-17 and Thr(696)/Thr(850)-MYPT1 were measured at different times during carbachol stimulation using site-specific antibodies. Thr(38)-CPI-17 phosphorylation increased concurrently with carbachol-stimulated force generation. This increase was reduced by inhibition of PKC during the entire contraction but was only reduced by ROCK inhibition during the sustained phase of contraction. MYPT1 showed high basal phosphorylation levels at both sites; however, only Thr(850) phosphorylation increased with carbachol stimulation; the increase was abolished by the inhibition of either ROCK or PKC. Our results suggest that during agonist stimulation, PKC regulates MLC phosphatase activity through phosphorylation of CPI-17. In contrast, ROCK phosphorylates both Thr(850)-MYPT1 and CPI-17, possibly through cross talk with a PKC pathway, but is only significant during the sustained phase of contraction. Last, our results demonstrate that there is a constitutively activate pool of ROCK that phosphorylates MYPT1 in the basal state, which may account for the high resting levels of MLC phosphorylation measured in rabbit bladder smooth muscle.
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Affiliation(s)
- Tanchun Wang
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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15
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Zhang Y, Kwon SH, Vogel WK, Filtz TM. PI(3,4,5)P3 potentiates phospholipase C-beta activity. J Recept Signal Transduct Res 2009; 29:52-62. [PMID: 19519170 DOI: 10.1080/10799890902729449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Phospholipase C-beta (PLC-beta) isozymes are key effectors in G protein-coupled signaling pathways. Previously, we showed that PLC-beta1 and PLC-beta3 bound immobilized PIP(3). In this study, PIP(3) was found to potentiate Ca(2+)-stimulated PLC-beta activities using an in vitro reconstitution assay. LY294002, a specific PI 3-kinase inhibitor, significantly inhibited 10 min of agonist-stimulated total IP accumulation. Both LY294002 and wortmannin inhibited 90 sec of agonist-stimulated IP(3) accumulation in intact cells. Moreover, transfected p110CAAX, a constitutively activated PI 3-kinase catalytic subunit, increased 90 sec of oxytocin-stimulated IP(3) accumulation. Receptor-ligand binding assays indicated that LY294002 did not affect G protein-coupled receptors directly, suggesting a physiological role for PIP(3) in directly potentiating PLC-beta activity. When coexpressed with p110CAAX, fluorescence-tagged PLC-beta3 was increasingly localized to the plasma membrane. Additional observations suggest that the PH domain of PLC-beta is not important for p110CAAX-induced membrane association.
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Affiliation(s)
- Yong Zhang
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331, USA
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16
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Xu YJ, Tappia PS, Goyal RK, Dhalla NS. Mechanisms of the lysophosphatidic acid-induced increase in [Ca(2+)](i) in skeletal muscle cells. J Cell Mol Med 2008; 12:942-54. [PMID: 18494935 PMCID: PMC4401138 DOI: 10.1111/j.1582-4934.2008.00139.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Although lysophosphatidic acid (LPA) is known to increase intracellularfree calcium concentration ([Ca2+]i) in different cell types, the effect of LPA on the skeletal muscle cells is not known. The present study was therefore undertaken to examine the effect of LPA on the [Ca2+]i in C2C12 cells. LPA induced a concentration and time dependent increase in [Ca2+]i, which was inhibited by VPC12249, VPC 32183 and dioctanoyl glycerol pyrophosphate, LPA1/3 receptor antagonists. Pertussis toxin, a Gi protein inhibitor, also inhibited the LPA-induced increase in [Ca2+]i. Inhibition of tyrosine kinase activities with tyrphostin A9 and genistein also prevented the increase in [Ca2+]i due to LPA. Likewise, wortmannin and LY 294002, phosphatidylinositol 3-kinase (PI3-K) inhibitors, inhibited [Ca2+]i response to LPA. The LPA effect was also attenuated by ethylene glycolbis(β-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA), an extracellular Ca2+ chelator, Ni2+ and KB-R7943, inhibitors of the Na+-Ca2+ exchanger; the receptor operated Ca2+ channel (ROC) blockers, 2-aminoethoxydiphenyl borate and SK&F 96365. However, the L-type Ca2+ channel blockers, verapamil and diltiazem; the store operated Ca2+ channel blockers, La3+ and Gd3+; a sarcoplasmic reticulum calcium pump inhibitor, thapsigargin; an inositol trisphosphate receptor antagonist, xestospongin and a phospholipase C inhibitor, U73122, did not prevent the increase [Ca2+]i due to LPA. Our data suggest that the LPA-induced increase in [Ca2+]i might occur through Gi-protein coupled LPA1/3 receptors that may be linked to tyrosine kinase and PI3-K, and may also involve the Na+-Ca2+ exchanger as well as the ROC. In addition, LPA stimulated C2C12 cell proliferation via PI3-K. Thus, LPA may be an important phospholipid in the regulation of [Ca2+]i and growth of skeletal muscle cells.
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Affiliation(s)
- Yan-Jun Xu
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Centre, Winnipeg, Manitoba, Canada
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17
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Babaei H, Azarmi Y. 17beta-estradiol inhibits calcium-dependent and -independent contractions in isolated human saphenous vein. Steroids 2008; 73:844-50. [PMID: 18486173 DOI: 10.1016/j.steroids.2008.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 02/22/2008] [Accepted: 04/01/2008] [Indexed: 12/13/2022]
Abstract
Studies suggest that estrogen modulate vascular reactivity but at present its exact mechanism of action has yet to be clarified. The aim of this study was to evaluate the effect of 17beta-estradiol (E2) on calcium-dependent and -independent contractions induced in the human saphenous veins (HSVs). HSVs were obtained from patients undergoing coronary artery bypass graft surgery. The ability of E2 to modulate Ca(2+) entry was assessed by obtaining concentration-response curve to CaCl(2) in the absence or presence of E2. In other experiments intracellular Ca(2+) was depleted by repeated application of phenylephrine in the presence of cyclopiazonic acid (CPA). Then, at the plateau of PGF(2alpha) contraction, E2 or nifedipine (NIF) was added. Involvement of protein kinase C (PKC) in relaxant effect of E2 was evaluated by application of phorbol-12,13-dibutyrate (PDBu) in normal or Ca(2+)-free Krebs' solution. When the contraction was obtained, E2 or NIF was added. In Ca(2+)-free hyperpolarizing solution, pretreatment with E2, concentration dependently reduced contractions induced by cumulative addition of calcium chloride. Furthermore, E2 elicited relaxant effects on the PGF(2alpha)-induced contractions in Ca(2+)-free solution in the presence or absence of CPA. Both E2 and NIF produced significant relaxation in HSV rings contracted by direct activation of PKC in Krebs' solution. However, in Ca(2+)-free solution, NIF failed to induce relaxant effect but E2 kept its effect on the PDBu-induced contraction. These results suggest that the relaxant effect of E2 on HSV is elicited by calcium-dependent and -independent pathways. The calcium-independent pathway may involve PKC inhibition.
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Affiliation(s)
- Hossein Babaei
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
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18
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Gao Y, Portugal AD, Liu J, Negash S, Zhou W, Tian J, Xiang R, Longo LD, Raj JU. Preservation of cGMP-induced relaxation of pulmonary veins of fetal lambs exposed to chronic high altitude hypoxia: role of PKG and Rho kinase. Am J Physiol Lung Cell Mol Physiol 2008; 295:L889-96. [PMID: 18757523 DOI: 10.1152/ajplung.00463.2007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The roles of Rho kinase (ROCK) and cGMP-dependent protein kinase (PKG) in cGMP-mediated relaxation of fetal pulmonary veins exposed to chronic hypoxia (CH) were investigated. Fourth generation pulmonary veins were dissected from near-term fetuses ( approximately 140 days of gestation) delivered from ewes exposed to chronic high altitude hypoxia for approximately 110 days (CH) and from control ewes. After constriction with endothelin-1, 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) caused a similar relaxation of both control and CH vessels. Rp-8-Br-PET-cGMPS (a PKG inhibitor) inhibited whereas Y-27632 (a ROCK inhibitor) augmented relaxation of control veins to 8-Br-cGMP. These effects were significantly diminished in CH veins. PKG protein expression and activity were greater whereas ROCK protein expression and activity were less in CH vessels compared with controls. Phosphorylation of threonine 696 (ROCK substrate) and serine 695 (PKG substrate) of the regulatory myosin phosphatase targeting subunit MYPT1 of myosin light chain (MLC) phosphatase was stimulated to a lesser extent in CH than in control veins by endothelin-1 (ROCK stimulant) and 8-Br-cGMP (PKG stimulant), respectively. The phosphorylation and dephosphorylation of MLC caused by endothelin-1 and 8-Br-cGMP, respectively, were less in CH veins than in controls. These results suggest that CH in utero upregulates PKG activity but attenuates PKG action in fetal pulmonary veins. These effects are offset by the diminished ROCK action on MYPT1 and MLC and thus lead to an unaltered response to cGMP.
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Affiliation(s)
- Yuansheng Gao
- Division of Neonatology, Los Angeles Biomedical Institute, Harbor-UCLA Medical Center, 1124 W. Carson Street, Torrance, CA 90502, USA.
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19
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Farghaly HSM, Blagbrough IS, Medina-Tato DA, Watson ML. Interleukin 13 increases contractility of murine tracheal smooth muscle by a phosphoinositide 3-kinase p110delta-dependent mechanism. Mol Pharmacol 2008; 73:1530-7. [PMID: 18276774 DOI: 10.1124/mol.108.045419] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Th2 cytokine interleukin (IL) 13 can elicit a number of responses consistent with a key role in the pathogenesis of asthma. We have used pharmacological and genetic approaches to demonstrate the role of signaling via the class I phosphoinositide 3-kinase p110delta isoform in IL-13-induced hyper-responsiveness of murine tracheal smooth muscle contractility in vitro. IL-13 treatment of tracheal tissue is associated with an early activation of phosphoinositide 3-kinase (PI3K), as assessed by phosphorylation of Akt. Tracheal smooth muscle contractility is enhanced by overnight incubation with IL-13, resulting in increased maximal contractions (E(max)) to carbachol (CCh) and KCl. Inhibition of PI3K by the non-isoform-selective inhibitors wortmannin or 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), or the selective inhibitor of the PI3K p110delta isoform 2-(6-aminopurin-9-ylmethyl)-5-methyl-3-O-tolyl-3H-quinazolin-4-one (IC87114), prevented IL-13-induced hyper-responsiveness. Consistent with a role for PI3K p110delta in IL-13-induced hyper-responsiveness, IL-13 was unable to induce hyper-responsiveness in tissues from mice expressing the catalytically inactive form of p110delta (p110delta(D910A)). These data indicate that IL-13 contributes to tracheal smooth muscle hyper-responsiveness via the PI3K p110delta isoform. In addition to previously reported effects on airway inflammation, inhibition of PI3K p110delta may be a useful target for the treatment of asthma by preventing IL-13-induced airway smooth muscle hyper-responsiveness.
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Affiliation(s)
- Hanan S M Farghaly
- Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK
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20
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Wang Y, Yoshioka K, Azam M, Takuwa N, Sakurada S, Kayaba Y, Sugimoto N, Inoki I, Kimura T, Kuwaki T, Takuwa Y. Class II phosphoinositide 3-kinase alpha-isoform regulates Rho, myosin phosphatase and contraction in vascular smooth muscle. Biochem J 2006; 394:581-92. [PMID: 16336212 PMCID: PMC1383708 DOI: 10.1042/bj20051471] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We demonstrated previously that membrane depolarization and excitatory receptor agonists such as noradrenaline induce Ca2+-dependent Rho activation in VSM (vascular smooth muscle), resulting in MP (myosin phosphatase) inhibition through the mechanisms involving Rho kinase-mediated phosphorylation of its regulatory subunit MYPT1. In the present study, we show in de-endothelialized VSM strips that the PI3K (phosphoinositide 3-kinase) inhibitors LY294002 and wortmannin inhibited KCl membrane depolarization- and noradrenaline-induced Rho activation and MYPT1 phosphorylation, with concomitant inhibition of MLC (20-kDa myosin light chain) phosphorylation and contraction. LY294002 also augmented de-phosphorylation of MLC and resultantly relaxation in KCl-contracted VSM, whereas LY294002 was much less effective or ineffective under the conditions in which MP was inhibited by either a phosphatase inhibitor or a phorbol ester in Rho-independent manners. VSM express at least four PI3K isoforms, including the class I enzymes p110alpha and p110beta and the class II enzymes PI3K-C2alpha and -C2beta. The dose-response relationships of PI3K-inhibitor-induced inhibition of Rho, MLC phosphorylation and contraction were similar to that of PI3K-C2alpha inhibition, but not to that of the class I PI3K inhibition. Moreover, KCl and noradrenaline induced stimulation of PI3K-C2alpha in a Ca2+-dependent manner, but not of p110alpha or p110beta. Down-regulation of PI3K-C2alpha expression by siRNA (small interfering RNA) inhibited contraction and phosphorylation of MYPT1 and MLC in VSM cells. Finally, intravenous wortmannin infusion induced sustained hypotension in rats, with inhibition of PI3K-C2alpha activity, GTP-loading of Rho and MYPT1 phosphorylation in the artery. These results indicate the novel role of PI3K-C2alpha in Ca2+-dependent Rho-mediated negative control of MP and thus VSM contraction.
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Affiliation(s)
- Yu Wang
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Kazuaki Yoshioka
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Mohammed Ali Azam
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Noriko Takuwa
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Sotaro Sakurada
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Yuji Kayaba
- †Department of Physiology, Chiba University Graduate School of Medical Sciences, 1-8-1 Inohana, Chiba, 260-8670, Japan
| | - Naotoshi Sugimoto
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Isao Inoki
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Takaharu Kimura
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
| | - Tomoyuki Kuwaki
- †Department of Physiology, Chiba University Graduate School of Medical Sciences, 1-8-1 Inohana, Chiba, 260-8670, Japan
| | - Yoh Takuwa
- *Department of Physiology, Kanazawa University Graduate School of Medicine, 13-1 Takara-machi, Kanazawa, 920-8640, Japan
- To whom correspondence should be addressed (email )
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Wenzel D, Schmidt A, Reimann K, Hescheler J, Pfitzer G, Bloch W, Fleischmann BK. Endostatin, the proteolytic fragment of collagen XVIII, induces vasorelaxation. Circ Res 2006; 98:1203-11. [PMID: 16574906 DOI: 10.1161/01.res.0000219899.93384.ed] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Collagen XVIII is an important component of the extracellular matrix and is expressed in basement membranes. Its degradation results in the generation of endostatin claimed to possess antiangiogenic activity. To date, only limited knowledge exists with regard to the cellular signaling of this molecule. We show in single-cell measurements using the Ca2+ indicator fura-2 acetoxy methylester (fura-2 AM) and the nitric oxide (NO) indicator 4,5-diaminofluorescein diacetate that application of endostatin (ES) (5 pmol/L, 100 ng/mL) induced Ca2+ spikes and an increase of NO production in human and murine endothelial cells. The NO response was independent of an increase in cytosolic Ca2+ and blocked by the endothelial NO synthase (eNOS) inhibitor NG-nitro-L-arginine methyl ester and by incubation with pertussis toxin known to inhibit G(i/o) proteins. The physiological relevance of this novel signaling pathway of ES was assessed with isometric force measurements in large and small arteries of mouse. Physiological concentrations of ES were found to decrease vascular tone in an endothelium-dependent manner. This occurred via an Arg-Gly-Asp (RGD) peptide-independent pathway through activation of G(i/o) proteins, phosphatidylinositol 3-kinase, Akt, and eNOS. We conclude that the proteolytic matrix fragment ES is a prominent vasorelaxing agent. Because ES is constantly released into the blood, it is a novel regulator of blood pressure and, therefore, represents an interesting pharmacological target.
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Affiliation(s)
- D Wenzel
- Institute of Physiology I, University of Bonn, Argelanderstr. 2a, 53115 Bonn, Germany
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22
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Kobayashi T, Hayashi Y, Taguchi K, Matsumoto T, Kamata K. ANG II enhances contractile responses via PI3-kinase p110 delta pathway in aortas from diabetic rats with systemic hyperinsulinemia. Am J Physiol Heart Circ Physiol 2006; 291:H846-53. [PMID: 16517941 DOI: 10.1152/ajpheart.01349.2005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the involvement of ANG II and phosphatidylinositol 3-kinase (PI3-K) in the enhanced aortic contractile responses induced by hyperinsulinemia in chronic insulin-treated Type 1 diabetic rats. Plasma ANG II levels were elevated in untreated compared with control diabetic rats and further increased in insulin-treated diabetic rats. Aortic contractile responses and systolic blood pressure were significantly enhanced in chronic insulin-treated diabetic rats compared with the other groups. These insulin-induced increases were largely prevented by cotreatment with losartan (an ANG II type 1 receptor antagonist) or enalapril (an angiotensin-converting enzyme inhibitor). LY-294002 (a PI3-K inhibitor) diminished the increases in contractile responses in ANG II-incubated aortas and aortas from chronic insulin-treated diabetic rats. The norepinephrine (NE)-stimulated levels of p110 delta-associated PI3-K activity and p110 delta protein expression were increased in aortas from insulin-treated diabetic compared with control and untreated diabetic rats, and chronic administration of losartan blunted these increases. Contractions were significantly larger in aortas from diabetic rats incubated with a low concentration (inducing approximately 10% of the maximum contraction) of ANG II or with NE or isotonic K+ than in aortas from nonincubated diabetic rats. NE-stimulated p110 PI3-K activity was elevated in aortas from diabetic rats coincubated with a noncontractile dose of ANG II. These results suggest that, in insulin-treated Type 1 diabetic rats with hyperinsulinemia, chronic ANG II type 1 receptor blockade blunts the increases in vascular contractility and blood pressure via a decrease in p110 delta-associated PI3-K activity.
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Affiliation(s)
- Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
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23
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Kono S, Stiffel VM, Gilbert RD. Effects of long-term, high-altitude hypoxia on tension and intracellular calcium responses in coronary arteries of fetal and adult sheep. ACTA ACUST UNITED AC 2005; 13:11-8. [PMID: 16303320 DOI: 10.1016/j.jsgi.2005.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Indexed: 11/17/2022]
Abstract
OBJECTIVES We have previously shown that after exposure to long-term hypoxia, fetal coronary flow is maintained at control levels despite a 25% reduction in cardiac output. We also demonstrated that coronary vascular rings isolated from the long-term hypoxic fetuses and studied in well-oxygenated bath system displayed significantly reduced depolarization-induced contraction strength in response to KCl. To study the mechanism of reduced fetal coronary vascular responses to KCl-induced contractions following exposure to long-term hypoxia, we measured tension and intracellular calcium simultaneously, as well as L-type Ca2+ channel density and sensitivity. METHODS Pregnant ewes were housed at altitude (3820 m) for approximately 110 days. At 138 to 141 days of gestation, long-term hypoxic and control animals were killed and fetal and adult left anterior descending coronary artery (LAD) was isolated and studied in a well-oxygenated bath system. Tension and intracellular calcium ([Ca2+]i) were measured simultaneously in response to increasing concentrations of KCl and, in addition, the sensitivity to the calcium channel blocker nifedipine was measured at a half maximal concentration of KCl. We also measured L-type Ca2+ channel density with (+)-[3H]PN200-110. RESULTS L-type Ca2+ channel density was decreased by approximately 31% in the long-term hypoxic fetal, but not adult, LAD. Tension in the long-term hypoxic fetal and adult LAD was significantly lower at all concentrations of KCl. [Ca2+]i was lower at rest in both fetal and adult LAD from long-term hypoxic animals and increased to lower levels at all concentrations of KCl. The ratio of tension to [Ca2+]i was also lower at all concentrations of KCl. Sensitivity to nifedipine was unchanged. CONCLUSIONS The reduced L-type Ca2+ channel density and the reduced [Ca2+]i response to KCl, as well as the reduced tension response to [Ca2+]i, could potentially be involved in the reduction in depolarization-induced contractions in LAD from long-term hypoxic fetuses. In hypoxic adults, reduced [Ca2+]i and reduced tension response to [Ca2+]i may be involved in the lower tension response to KCl-induced contractions.
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Affiliation(s)
- Satoshi Kono
- Center for Perinatal Biology, Loma Linda University, Loma Linda, California 92382, USA
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24
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Budzyn K, Marley PD, Sobey CG. Opposing Roles of Endothelial and Smooth Muscle Phosphatidylinositol 3-Kinase in Vasoconstriction: Effects of Rho-Kinase and Hypertension. J Pharmacol Exp Ther 2005; 313:1248-53. [PMID: 15743931 DOI: 10.1124/jpet.104.082784] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Phosphatidylinositol 3-kinase (PI3K) can activate endothelial nitric oxide synthase (eNOS), leading to production of the vasodilator NO. In contrast, vascular smooth muscle (VSM) PI3K may partially mediate vascular contraction, particularly during hypertension. We tested whether endothelial and VSM PI3K may have opposing functional roles in regulating vascular contraction. Secondly, we tested whether the procontractile protein rho-kinase can suppress endothelial PI3K/eNOS activity in intact arteries, thus contributing to vasoconstriction by G protein-coupled receptor (GPCR) agonists. We studied contractile responses to the GPCR agonist phenylephrine, and the receptor-independent vasoconstrictor KCl, in aortic rings from Sprague-Dawley rats. In endothelium-intact rings, the PI3K inhibitor wortmannin (0.1 microM) markedly augmented responses to phenylephrine (P < 0.05) by approximately 50% but not to KCl. However, in endothelium-denuded or N(G)-nitro-L-arginine methyl ester (L-NAME) (100 microM)-treated rings, wortmannin reduced responses to phenylephrine and KCl (P < 0.05). Furthermore, the rhokinase inhibitor Y-27632 (R-[+]-trans-N-[4-pyridyl]-4-[1-aminoethyl]-cycloheaxanecarboxamide; 1 microM) abolished responses to phenylephrine, and this effect was partially reversed by wortmannin or L-NAME. The ability of wortmannin to oppose the effect of rho-kinase inhibition on contractions to phenylephrine was L-NAME-sensitive. In aortas from angiotensin II-induced hypertensive rats, relaxation to acetylcholine (10 microM) was impaired (P < 0.05), and vasoconstriction by phenylephrine was markedly enhanced and not further augmented by wortmannin. These data suggest that endothelial PI3K-induced NO production can modulate GPCR agonist-induced vascular contraction and that this effect is impaired in hypertension in association with endothelial dysfunction. In addition, endothelial rho-kinase may act to suppress PI3K activity and, hence, attenuate NO-mediated relaxation and augment GPCR-dependent contraction.
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Affiliation(s)
- Klaudia Budzyn
- Department of Pharmacology, University of Melbourne, Parkville, Victoria, Australia
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Teng B, Qin W, Ansari HR, Mustafa SJ. Involvement of p38-mitogen-activated protein kinase in adenosine receptor-mediated relaxation of coronary artery. Am J Physiol Heart Circ Physiol 2005; 288:H2574-80. [PMID: 15653766 DOI: 10.1152/ajpheart.00912.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The purpose of this study was to explore the involvement of adenosine receptor(s) in porcine coronary artery (PCA) relaxation and to define the role of MAPK signaling pathways. Isometric tensions were recorded in denuded PCA rings. 5'-(N-ethylcarboxamido)adenosine (NECA), a nonselective adenosine receptor agonist, induced a concentration-dependent relaxation (EC(50) = 16.8 nM) of PGF(2alpha) (10 microM)-preconstricted arterial rings. NECA-induced relaxation was completely blocked by 0.1 microM SCH-58261 (A(2A) antagonist) at lower doses (1-40 nM) but not at higher doses (80-1,000 nM). MRS-1706 (1 microM, A(2B) antagonist) was able to shift the NECA concentration-response curve to the right. CGS-21680 (selective A(2A) agonist) induced responses similarly to NECA, whereas N(6)-cyclopentyladenosine (A(1) agonist) and Cl-IB-MECA (A(3) agonist) did not. Furthermore, the effect of NECA was attenuated by the addition of SB-203580 (10 microM, p38 MAPK inhibitor) but not by PD-98059 (10 microM, MEK inhibitor). Interestingly, SB-203580 had no effect on CGS-21680-induced relaxation. Western blot analysis demonstrated that PGF(2alpha) and adenosine agonists stimulated p38 MAPK at a concentration of 40 nM in PCA smooth muscle cells. MRS-1706 (1 microM) significantly reduced NECA-induced p38 MAPK phosphorylation. Addition of NECA and SB-203580 alone or in combination inhibited PGF(2alpha)-induced p38 MAPK. Western blot data were further confirmed by p38 MAPK activity measurement using activating transcription factor-2 assay. Our results suggest that the adenosine receptor subtype involved in causing relaxation of porcine coronary smooth muscle is mainly A(2A) subtype, although A(2B) also may play a role, possibly through p38 MAPK pathway.
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Affiliation(s)
- Bunyen Teng
- Dept. of Pharmacology and Toxicology, Brody School of Medicine, East Carolina Univ., Greenville, NC 27834, USA
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Rubin LJ, Magliola L, Feng X, Jones AW, Hale CC. Metabolic activation of AMP kinase in vascular smooth muscle. J Appl Physiol (1985) 2004; 98:296-306. [PMID: 15377643 DOI: 10.1152/japplphysiol.00075.2004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
AMP-activated kinase (AMPK) is a highly conserved heterotrimeric kinase that functions as a metabolic master switch to coordinate cellular enzymes involved in carbohydrate and fat metabolism that regulate ATP conservation and synthesis. AMPK is activated by conditions that increase AMP-to-ATP ratio, such as exercise and metabolic stress. In the present study, we probed whether AMPK was expressed in vascular smooth muscle and would be activated by metabolic stress. Endothelium-denuded porcine carotid artery segments were metabolically challenged with 2-deoxyglucose (10 mM) plus N(2) (N(2)-2DG). These vessels exhibited a rapid increase in AMPK activity by 1 min that was near maximal by 20 min. AMPK inactivation on return to normal physiological saline was approximately 50% in 1 min and fully recovered by 5 min. Immunoprecipitation of the alpha(1)- and alpha(2)-catalytic subunit followed by immunoblot analysis for [P]Thr(172)-AMPK indicates that alpha(1)-AMPK accounts for all activity. Little if any alpha(2)-AMPK was detected in carotid smooth muscle. AMPK activity was not increased by contractile agonist (endothelin-1) or by the reported AMPK activators 5-aminoimidazole-4-carboxamide ribofuranoside (2 mM), metformin (2 mM), or phenformin (0.2 mM). AMPK activation by N(2)-2DG was associated with a rapid and pronounced reduction in endothelin-induced force and reduced phosphorylation of Akt and Erk 1/2. These data demonstrate that AMPK expression differs in vascular smooth muscle compared with striated muscles and that activation and inactivation after metabolic stress occur rapidly and are associated with signaling pathways that may regulate smooth-muscle contraction.
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Affiliation(s)
- L J Rubin
- Dept. of Biomedical Sciences, University of Missouri, Columbia, MO 65211, USA.
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