1
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Ito MA, Kojima E, Yanagihara Y, Yoshida K, Matsuoka I. Differential Effects of Gq Protein-Coupled Uridine Receptor Stimulation on IL-8 Production in 1321N1 Human Astrocytoma Cells. Biol Pharm Bull 2022; 45:691-697. [PMID: 35650097 DOI: 10.1248/bpb.b21-01020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
G-protein-coupled receptors (GPCRs) trigger various physiological functions. GPCR-mediated effects largely depend on the receptor-associated G-protein subtypes. However, compelling evidence suggests that single receptor proteins activate multiple G-protein subtypes to induce diverse physiological responses. This study compared responses mediated by three different Gq-binding uridine nucleotide receptors, P2Y2, P2Y4, and P2Y6, by measuring Ca2+ signaling and interleukin (IL)-8 production. In 1321N1 human astrocytoma cells stably expressing these receptors, agonist stimulation evoked concentration-dependent intracellular Ca2+ elevation to a similar extent. In contrast, agonist-induced IL-8 production was prominent in P2Y6-expressing cells, but not in P2Y2- and P2Y4-expressing cells. In addition to inhibition of Gq signaling, G12 signal blockade attenuated uridine 5'-diphosphate (UDP)-induced IL-8 production, suggesting the involvement of a small G-protein pathway. The Rac inhibitor EHop-16 prevented UDP-induced IL-8 release. The P2Y6-triggered IL-8 production was also inhibited by extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and protein kinase B (Akt) inhibitors. These results suggest that P2Y6 receptor-induced IL-8 production requires Gq-mediated Ca2+ signaling as well as G12-mediated activation of Rac. The results also suggest the importance of considering the involvement of multiple G proteins in understanding GPCR-mediated functions.
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Affiliation(s)
- Masa-Aki Ito
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare
| | - Erika Kojima
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare
| | - Yu Yanagihara
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare
| | - Kazuki Yoshida
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare
| | - Isao Matsuoka
- Laboratory of Pharmacology, Faculty of Pharmacy, Takasaki University of Health and Welfare
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2
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Genetic Variation in the SLC8A1 Calcium Signaling Pathway Is Associated With Susceptibility to Kawasaki Disease and Coronary Artery Abnormalities. ACTA ACUST UNITED AC 2016; 9:559-568. [DOI: 10.1161/circgenetics.116.001533] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 11/02/2016] [Indexed: 02/07/2023]
Abstract
Background—
Kawasaki disease (KD) is an acute pediatric vasculitis in which host genetics influence both susceptibility to KD and the formation of coronary artery aneurysms. Variants discovered by genome-wide association studies and linkage studies only partially explain the influence of genetics on KD susceptibility.
Methods and Results—
To search for additional functional genetic variation, we performed pathway and gene stability analysis on a genome-wide association study data set. Pathway analysis using European genome-wide association study data identified 100 significantly associated pathways (
P
<5×10
−
4
). Gene stability selection identified 116 single nucleotide polymorphisms in 26 genes that were responsible for driving the pathway associations, and gene ontology analysis demonstrated enrichment for calcium transport (
P
=1.05×10
−
4
). Three single nucleotide polymorphisms in solute carrier family 8, member 1 (
SLC8A1
), a sodium/calcium exchanger encoding NCX1, were validated in an independent Japanese genome-wide association study data set (meta-analysis
P
=0.0001). Patients homozygous for the A (risk) allele of rs13017968 had higher rates of coronary artery abnormalities (
P
=0.029). NCX1, the protein encoded by
SLC8A1
, was expressed in spindle-shaped and inflammatory cells in the aneurysm wall. Increased intracellular calcium mobilization was observed in B cell lines from healthy controls carrying the risk allele.
Conclusions—
Pathway-based association analysis followed by gene stability selection proved to be a valuable tool for identifying risk alleles in a rare disease with complex genetics. The role of
SLC8A1
polymorphisms in altering calcium flux in cells that mediate coronary artery damage in KD suggests that this pathway may be a therapeutic target and supports the study of calcineurin inhibitors in acute KD.
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3
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Baetta R, Lento S, Ghilardi S, Barbati E, Corsini A, Tremoli E, Banfi C. Atorvastatin reduces long pentraxin 3 expression in vascular cells by inhibiting protein geranylgeranylation. Vascul Pharmacol 2015; 67-69:38-47. [PMID: 25849951 DOI: 10.1016/j.vph.2014.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 11/12/2014] [Accepted: 11/27/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND The long pentraxin PTX3 is an acute-phase multi-functional protein that might play both positive and detrimental effects under different pathophysiological conditions. We previously showed that statins down-regulate the release of PTX3 in human endothelial cells (ECs). The present study investigated the mechanism mediating this effect, its occurrence in other cells involved in atherogenesis, and whether it takes place in experimental atherosclerosis. METHODS AND RESULTS We found that atorvastatin (1-5 μmol/L) decreased the production and release of PTX3 in human ECs through a post-transcriptional effect. Co-incubation with mevalonate or geranylgeranyl pyrophosphate prevented this effect. Direct blockade of geranylgeranyl transferase I by GGTI-286, treatment with the Rac inhibitor NSC23766 or silencing of the geranylgeranylated GTPase Rac2 by siRNA closely mimicked the action of atorvastatin. In contrast, inactivation of other geranylgeranylated proteins such as RhoA, RhoB, and RhoC or Rac1 did not affect PTX3 release. In addition, we found that atorvastatin also decreased PTX3 secretion in aortic SMCs through a mechanism likely dependent on protein geranylgeranylation, while no effect was observed in monocytes. Finally, we found that atherosclerotic lesions from cholesterol-fed rabbits treated with atorvastatin (2.5 mg/kg/day for 8 weeks) showed less immunoreactive PTX3 than lesions from control animals. CONCLUSIONS Results suggest that statins may interfere with PTX3 expression in vascular cells via inhibition of protein geranylgeranylation. Since PTX3 is increasingly regarded as an important mediator of the inflammatory response underlying atherosclerosis and its complications, these results highlight the need for further studies of the role of PTX3 and its potential pharmacological modulation in cardiovascular disease.
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Affiliation(s)
- Roberta Baetta
- Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | - Sabrina Lento
- Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy
| | | | - Elisa Barbati
- Humanitas Clinical and Research Center, Via Manzoni 113, 20089 Rozzano, Milano, Italy
| | - Alberto Corsini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy; MultiMedica IRCCS, Via Milanese 300, 20099 Sesto San Giovanni, Milano, Italy
| | - Elena Tremoli
- Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy; Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, 20133 Milano, Italy
| | - Cristina Banfi
- Centro Cardiologico Monzino IRCCS, Via Parea 4, 20138 Milano, Italy.
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4
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Barnes J, Pat B, Chen YW, Powell PC, Bradley WE, Zheng J, Karki A, Cui X, Guichard J, Wei CC, Collawn J, Dell'Italia LJ. Whole-genome profiling highlights the molecular complexity underlying eccentric cardiac hypertrophy. Ther Adv Cardiovasc Dis 2014; 8:97-118. [PMID: 24692245 DOI: 10.1177/1753944714527490] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Heart failure is typically preceded by myocardial hypertrophy and remodeling, which can be concentric due to pressure overload (PO), or eccentric because of volume overload (VO). The molecular mechanisms that underlie these differing patterns of hypertrophy are distinct and have yet to be fully elucidated. Thus, the goal of this work is to identify novel therapeutic targets for cardiovascular conditions marked by hypertrophy that have previously been resistant to medical treatment, such as a pure VO. METHODS Concentric or eccentric hypertrophy was induced in rats for 2 weeks with transverse aortic constriction (TAC) or aortocaval fistula (ACF), respectively. Hemodynamic and echocardiographic analysis were used to assess the development of left ventricular (LV) hypertrophy and functional differences between groups. Changes in gene expression were determined by microarray and further characterized with Ingenuity Pathway Analysis. RESULTS Both models of hypertrophy increased LV mass. Rats with TAC demonstrated concentric LV remodeling while rats with ACF exhibited eccentric LV remodeling. Microarray analysis associated eccentric remodeling with a more extensive alteration of gene expression compared with concentric remodeling. Rats with VO had a marked activation of extracellular matrix genes, promotion of cell cycle genes, downregulation of genes associated with oxidative metabolism, and dysregulation of genes critical to cardiac contractile function. Rats with PO demonstrated similar categorical changes, but with the involvement of fewer individual genes. CONCLUSIONS Our results indicate that eccentric remodeling is a far more complex process than concentric remodeling. This study highlights the importance of several key biological functions early in the course of VO, including regulation of matrix, metabolism, cell proliferation, and contractile function. Thus, the results of this analysis will inform the ongoing search for new treatments to prevent the progression to heart failure in VO.
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Affiliation(s)
- Justin Barnes
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USADepartment of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Betty Pat
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yuan-Wen Chen
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Pamela C Powell
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wayne E Bradley
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Junying Zheng
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Amrit Karki
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jason Guichard
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USADepartment of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Chih-Chang Wei
- Birmingham Department of Veteran Affairs, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - James Collawn
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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5
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Sakamoto K, Wada I, Kimura J. Inhibition of Rab1 GTPase and endoplasmic reticulum-to-Golgi trafficking underlies statin's toxicity in rat skeletal myofibers. J Pharmacol Exp Ther 2011; 338:62-9. [PMID: 21467191 DOI: 10.1124/jpet.111.179762] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
HMG-CoA reductase inhibitor statins are used for the treatment of hypercholesterolemia. However, statins have adverse effects on skeletal muscles with unknown mechanism. We have reported previously that fluvastatin induced vacuolation and cell death in rat skeletal myofibers by depleting geranylgeranylpyrophosphate (GGPP) and suppressing small GTPases, particularly Rab (FASEB J 21:4087-4094, 2007). Rab1 is one of the most susceptible Rab isoforms to GGPP depletion and is essential for endoplasmic reticulum (ER)-to-Golgi trafficking. Here, we explored whether Rab1 and ER-to-Golgi vesicle trafficking were affected by statins in cultured single myofibers isolated from flexor digitorum brevis muscles of adult rats. Western blot analysis revealed that Rab1A protein resided predominantly in membrane but not in cytosol in control myofibers, whereas it was opposite in fluvastatin-treated myofibers, indicating that fluvastatin inhibited Rab1A translocation from cytosol to membrane. GGPP supplementation prevented the effect of fluvastatin on Rab1A translocation. Brefeldin A, a specific suppressor of ER-to-Golgi trafficking, induced vacuolation and cell death in myofibers in a manner similar to that of fluvastatin. Although ER-to-Golgi traffic suppression induces unfolded protein response (UPR) and cell death in some cell types, neither fluvastatin nor brefeldin A up-regulated UPR in myofibers. Immunofluorescence study revealed that the distribution of an ER marker, calnexin, was restricted to the region around nucleus with fluvastatin, suggesting the inhibition of ER membrane traffic by fluvastatin. We conclude that suppression of Rab1 GTPase and the subsequent inhibition of ER-to-Golgi traffic are involved in statin-induced skeletal myotoxicity.
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Affiliation(s)
- Kazuho Sakamoto
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Fukushima 960-1295, Japan.
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6
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Tanaka S, Sakamoto K, Yamamoto M, Mizuno A, Ono T, Waguri S, Kimura J. Mechanism of statin-induced contractile dysfunction in rat cultured skeletal myofibers. J Pharmacol Sci 2010; 114:454-63. [PMID: 21127387 DOI: 10.1254/jphs.10229fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
An adverse effect of statins, cholesterol-lowering drugs, is contractile dysfunction of skeletal muscles. We investigated the mechanism underlying this effect in cultured myofibers isolated from rats. Fluvastatin (Flv) for 72 h decreased caffeine- and ionomycin-induced contraction of myofibers and Ca(2+) release from sarcoplasmic reticulum (SR). Ca(2+)-shortening curves measured in skinned myofibers indicated that myofibrillar Ca(2+) sensitivity was unaffected by Flv. A luciferin-luciferase assay revealed less ATP contents in Flv-treated myofibers. Among mevalonate metabolites, including geranylgeranylpyrophosphate (GGPP), farnesylpyrophosphate (FPP), coenzyme Q9, and coenzyme Q10, only GGPP prevented Flv-induced ATP reduction. A selective Rab geranylgeranyltransferase (GG transferase) inhibitor, perillyl alcohol (POH), and a specific GG transferase-I inhibitor, GGTI-298, both mimicked Flv in decreasing ATP and contraction. Mitochondrial membrane potential was decreased by Flv, and this effect was rescued by GGPP and mimicked by POH and GGTI-298. An endoplasmic reticulum (ER)-to-Golgi traffic inhibitor, brefeldin A, and a Rho inhibitor, membrane permeable exoenzyme C3 transferase, both decreased ATP. We conclude that statin-induced contractile dysfunction is due to reduced Ca(2+) release from SR and reduced ATP levels in myofibers with damaged mitochondria. GGPP depletion and subsequent inactivation of Rab1, possibly along with Rho, may underlie the mitochondrial damage by Flv.
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Affiliation(s)
- Syoko Tanaka
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Fukushima 960-1295, Japan
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7
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Zheng X, Diao L, Ekins S, Polli JE. Why we should be vigilant: drug cytotoxicity observed with in vitro transporter inhibition studies. Biochem Pharmacol 2010; 80:1087-92. [PMID: 20599790 DOI: 10.1016/j.bcp.2010.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 06/11/2010] [Accepted: 06/15/2010] [Indexed: 01/11/2023]
Abstract
From routine in vitro drug-transporter inhibition assays, observed inhibition is typically assumed from direct interaction with the transporter. Other mechanisms that possibly reduce substrate uptake are not frequently fully examined. The objective of this study was to investigate the association of transporter inhibition with drug cytotoxicity. From a pool of drugs that were identified as known ASBT or OCTN2 inhibitors, 21 drugs were selected to screen inhibitory potency of their prototypical substrate and cytotoxicity against three human sodium-dependent solute carrier (SLC) transporters: apical sodium-dependent bile acid transporter (ASBT), organic cation/carnitine transporter (OCTN2), and the excitatory amino acid transporter 4 (EAAT4) in stable cell lines. Twenty drugs showed apparent inhibition in OCTN2-MDCK and ASBT-MDCK. Four dihydropyridine calcium channel blockers were cytotoxic to MDCK cells, and the observed cytotoxicity of three of them accounted for their apparent OCTN2 inhibition, and consequently were classified as non-OCTN2 inhibitors. Meanwhile, since their cytotoxicity only moderately contributed to ASBT inhibition, these three were still considered ASBT inhibitors. Four other drugs showed apparent inhibition in EAAT4-HEK cells, and cytotoxicity of three drugs corresponded with their inhibition of this transporter. Therefore, cytotoxicity significantly affected EAAT4 observations. Results showed the potential of cytotoxicity as a mechanism that can account for apparent in vitro transporter inhibition. Drug cytotoxicity varied in different cell lines, which could increase false positives for pharmacophore development.
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Affiliation(s)
- Xiaowan Zheng
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N. Pine Street, Baltimore, MD 21201, United States
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8
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Sakamoto K, Owada Y, Shikama Y, Wada I, Waguri S, Iwamoto T, Kimura J. Involvement of Na+/Ca2+ exchanger in migration and contraction of rat cultured tendon fibroblasts. J Physiol 2009; 587:5345-59. [PMID: 19770194 DOI: 10.1113/jphysiol.2009.172080] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In response to injury and inflammation of tendons, tendon fibroblasts are activated, migrate to the wound, and eventually induce contraction of the extracellular matrices to repair the tissue. Under such conditions, Ca(2+) signalling is involved in motility and contractility of tendon fibroblasts. Using cultured tendon fibroblasts isolated from rat Achilles tendons, we investigated functional expression of Na(+)/Ca(2+) exchangers (NCX). The fluorometric study showed that the intracellular Ca(2+) concentration ([Ca(2+)](i)) was increased by reducing extracellular Na(+) concentration ([Na(+)](o)) in tendon fibroblasts. Selective NCX inhibitors, KB-R7943 and SEA0400, both attenuated [Na(+)](o)-dependent [Ca(2+)](i) elevation and the resting [Ca(2+)](i) in tendon fibroblasts. RT-PCR, Western blots and sequence analyses revealed that NCX1.3 and NCX1.7 were expressed in cultured tendon fibroblasts. NCX2 mRNA was undetected. NCX3 expression was negligibly low. Immunofluorescence microscopy indicated that NCX1 protein localized in the plasma membrane especially at the microspikes of tendon fibroblasts. In the wound-healing scratch assay, the cells migrated toward the space created by a scratch and almost completely filled the space within 48 h. This phenomenon was significantly suppressed by KB-R7943 and SEA0400. Furthermore, the NCX inhibitors abrogated the tendon fibroblast-mediated collagen-matrix contractions. Two types of siRNAs for NCX1 also suppressed the migration and contraction of tendon fibroblasts. We conclude that NCX is expressed and mediates Ca(2+) influx in cultured tendon fibroblasts. Since the pharmacological inhibitors and siRNA for NCX1 suppressed motility and contractility of tendon fibroblasts, NCX may play an important role in the function of tendon fibroblasts in the wound healing.
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Affiliation(s)
- Kazuho Sakamoto
- Department of Pharmacology, Fukushima Medical University, School of Medicine, Hikarigaoka, Fukushima, Japan.
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9
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Rodrigues AC, Curi R, Hirata MH, Hirata RDC. Decreased ABCB1 mRNA expression induced by atorvastatin results from enhanced mRNA degradation in HepG2 cells. Eur J Pharm Sci 2009; 37:486-91. [DOI: 10.1016/j.ejps.2009.04.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 03/19/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
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10
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Kimura J, Ono T, Sakamoto K, Ito E, Watanabe S, Maeda S, Shikama Y, Yatabe MS, Matsuoka I. Na+ -Ca2+ exchanger expression and its modulation. Biol Pharm Bull 2009; 32:325-31. [PMID: 19252272 DOI: 10.1248/bpb.32.325] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Here we reviewed our recent work on the chronic effects of nicotine on the Na+ -Ca2+ exchanger (NCX) gene and protein expressions in various organs of rats treated with nicotine in the drinking water for 4-12 weeks. Microarray analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) did not detect significant changes in NCX mRNA expression in cerebral cortex, hippocampus, heart and skeletal muscle. However, NCX1 protein was up-regulated by nicotine in cerebral cortex and hippocampus, but was down-regulated in the heart. NCX2 protein was up-regulated by nicotine in hippocampus. We suggest that although mRNA change was insignificant, NCX protein expression was altered by chronic nicotine administration in brain and heart in rats. We also reviewed our work on modulators of NCX gene expression and function in cardiac myocytes.
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Affiliation(s)
- Junko Kimura
- Department of Pharmacology, Fukushima Medical University, School of Medicine, Japan.
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11
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Maeda S, Sakamoto K, Matsuoka I, Iwamoto T, Kimura J. Lysophosphatidylcholine Increases Na+/Ca2+ Exchanger Expression via RhoB-Geranylgeranylation in H9c2 Cells. J Pharmacol Sci 2009; 109:565-72. [DOI: 10.1254/jphs.08253fp] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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12
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Hu YF, Chen YC, Cheng CC, Higa S, Chen YJ, Chen SA. Fluvastatin reduces pulmonary vein spontaneous activity through nitric oxide pathway. J Cardiovasc Electrophysiol 2008; 20:200-6. [PMID: 18775044 DOI: 10.1111/j.1540-8167.2008.01281.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Pulmonary veins (PVs) are the most important focus for the generation of atrial fibrillation. The HMG-CoA reductase inhibitors (statins) can reduce the occurrence of atrial fibrillation. The purposes of this study were to evaluate whether statins may inhibit the PV arrhythmogenic activity to prevent atrial arrhythmias from PVs and to investigate the link between fluvastatin, nitric oxide synthase (NOS) activity, mechanical activity, and electrical activity. METHODS Conventional microelectrodes and Western blot were used to record the electrical activity, diastolic tension, contractility and expression of Akt, endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and phosphorylated Akt and eNOS before and after the administration of fluvastatin in rabbit PVs or atria. RESULTS Fluvastatin decreased the PV spontaneous activity, diastolic tension, and contractility, but did not change the action potential duration or resting membrane potential. The effects of fluvastatin on the PV firing rate and diastolic tension were attenuated in the presence of L-NAME (100 microM), wortmannin (100 nM), and ODQ (3 microM). Fluvastatin (1 muM) increased the phosphorylated Akt and eNOS, but did not change the total Akt or eNOS in the PVs and atria. In contrast, fluvastatin (1 microM) decreased the total nNOS in the PVs and atria. CONCLUSIONS AND IMPLICATIONS Fluvastatin produced nitric oxide through the PI3kinase/Akt pathway, thus reducing the PV vascular diastolic tension and PV spontaneous activity. These results may contribute to the beneficial effects of statins.
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Affiliation(s)
- Yu-Feng Hu
- Division of Cardiology and Cardiovascular Research Center, Veterans General Hospital-Taipei, Taiwan
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13
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Xu N, Keung B, Myat MM. Rho GTPase controls invagination and cohesive migration of the Drosophila salivary gland through Crumbs and Rho-kinase. Dev Biol 2008; 321:88-100. [PMID: 18585373 DOI: 10.1016/j.ydbio.2008.06.007] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2008] [Revised: 05/28/2008] [Accepted: 06/03/2008] [Indexed: 01/26/2023]
Abstract
Coordinated cell movements shape simple epithelia into functional tissues and organs during embryogenesis. Regulators and effectors of the small GTPase Rho have been shown to be essential for epithelial morphogenesis in cell culture; however, the mechanism by which Rho GTPase and its downstream effectors control coordinated movement of epithelia in a developing tissue or organ is largely unknown. Here, we show that Rho1 GTPase activity is required for the invagination of Drosophila embryonic salivary gland epithelia and for directed migration of the internalized gland. We demonstrate that the absence of zygotic function of Rho1 results in the selective loss of the apical proteins, Crumbs (Crb), Drosophila atypical PKC and Stardust during gland invagination and that this is partially due to reduced crb RNA levels and apical localization. In parallel to regulation of crb RNA and protein, Rho1 activity also signals through Rho-kinase (Rok) to induce apical constriction and cell shape change during invagination. After invagination, Rho-Rok signaling is required again for the coordinated contraction and dorsal migration of the proximal half of the gland. We also show that Rho1 activity is required for proper development of the circular visceral mesoderm upon which the gland migrates. Our genetic and live-imaging analyses provide novel evidence that the proximal gland cells play an essential and active role in salivary gland migration that propels the entire gland to turn and migrate posteriorly.
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Affiliation(s)
- Na Xu
- Department of Cell and Developmental Biology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10065, USA
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14
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Saito A, Saito N, Mol W, Furukawa H, Tsutsumida A, Oyama A, Sekido M, Sasaki S, Yamamoto Y. Simvastatin inhibits growth via apoptosis and the induction of cell cycle arrest in human melanoma cells. Melanoma Res 2008; 18:85-94. [DOI: 10.1097/cmr.0b013e3282f60097] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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15
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Sakamoto K, Honda T, Yokoya S, Waguri S, Kimura J. Rab-small GTPases are involved in fluvastatin and pravastatin-induced vacuolation in rat skeletal myofibers. FASEB J 2007; 21:4087-94. [PMID: 17634390 DOI: 10.1096/fj.07-8713com] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Three-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitors, known as statins, induce skeletal muscle injury including myalgia, myositis, and rhabdomyolysis. The mechanism of this myotoxicity remains unknown. This study examined the effect of statins on single skeletal myofibers enzymatically isolated from the rat flexor digitorum brevis muscles. Fluvastatin and pravastatin induced the formation of numerous vacuoles in the myofibers after 72 h of treatment. This effect progressed in a time- and concentration-dependent manner and, consequently, cell death occurred after 120 h. Electron micrographs revealed craters along the sarcolemma and swelling of the sarcoplasmic reticula and mitochondria, in addition to intracellular vacuoles. When caffeine was added after 72 h of fluvastatin treatment, contractile shortening of statin-treated myofibers was significantly attenuated and blebs formed on the surface of the myofibers. The coapplication of geranylgeranylpyrophosphate (GGPP) with fluvastatin prevented the morphological changes, while that of farnesylpyrophosphate (FPP) was ineffective. Furthermore, perillyl alcohol, an inhibitor of Rab geranylgeranyl transferase and geranylgeranyl transferase-I (GGTase-I), mimicked the effect of statins, while a specific GGTase-I inhibitor (GGTI-298) or a farnesyl transferase inhibitor (FTI-277) failed to do so. These results suggest that the inactivation of Rab GTPase, which involved in intracellular membrane transport, is a crucial factor in statin-induced-morphological abnormality in skeletal muscle fibers.
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MESH Headings
- Animals
- Cell Line
- Cells, Cultured
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Fatty Acids, Monounsaturated/adverse effects
- Female
- Fluvastatin
- Hydroxymethylglutaryl-CoA Reductase Inhibitors/adverse effects
- Indoles/adverse effects
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/enzymology
- Muscle Fibers, Skeletal/pathology
- Muscle Fibers, Skeletal/ultrastructure
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Pravastatin/adverse effects
- Rats
- Rats, Sprague-Dawley
- Rats, Wistar
- Vacuoles/drug effects
- Vacuoles/enzymology
- Vacuoles/pathology
- Vacuoles/ultrastructure
- rab GTP-Binding Proteins/adverse effects
- rab GTP-Binding Proteins/physiology
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Affiliation(s)
- Kazuho Sakamoto
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Hikarigaoka 1, Fukushima 960-1295, Japan.
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16
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Sakamoto T, Ishibashi T, Sugimoto K, Sakamoto N, Ohkawara H, Niinuma M, Nagata K, Kamioka M, Sugimoto N, Watanabe A, Kurabayashi M, Takuwa Y, Maruyama Y. RhoA-dependent PAI-1 gene expression induced in endothelial cells by monocyte adhesion mediates geranylgeranyl transferase I and Ca2+ signaling. Atherosclerosis 2007; 193:44-54. [PMID: 16973169 DOI: 10.1016/j.atherosclerosis.2006.08.036] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Revised: 08/07/2006] [Accepted: 08/11/2006] [Indexed: 11/29/2022]
Abstract
We investigated the role of RhoA activation and its mechanism in plasminogen activator inhibitor-1 (PAI-1) gene expression induced in endothelial cells by monocyte adhesion. Isolated human peripheral blood monocytes were added to cultured human coronary endothelial cells. Monocyte adhesion to endothelial cells increased PAI-1 expression at the transcriptional level and activated RhoA which was accompanied by an increase in the activity of geranylgeranyl transferase I (GGTase I), an enzyme responsible for geranylgeranylation, and actin stress fiber formation. Inhibition of RhoA by C3 exoenzyme or by adenovirus-mediated expression of N19RhoA, as well as by pravastatin, prevented the upregulation of PAI-1 induced by monocyte adhesion. GGTI-286, an inhibitor of GGTase I, prevented the monocyte-induced RhoA activation and PAI-1 expression in endothelial cells. Monocyte attachment induced an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) in endothelial cells and Ca(2+) chelation prevented the increased promoter activity and expression of PAI-1 induced by monocyte adhesion. C3 exoenzyme and GGTI-286 also suppressed endothelial intracellular Ca(2+) mobilization and Ca(2+) entry induced by monocytes. The present study shows that GGTase I plays a role in the RhoA activation in endothelial cells induced by monocyte adhesion and that GGTase I-mediated Ca(2+) signaling may contribute to RhoA-dependent PAI-1 gene expression.
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Affiliation(s)
- Takayuki Sakamoto
- First Department of Internal Medicine, Fukushima Medical University, Fukushima, Japan
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17
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Maeda S, Matsuoka I, Kimura J. Modulation pathways of NCX mRNA stability: involvement of RhoB. Ann N Y Acad Sci 2007; 1099:193-4. [PMID: 17446458 DOI: 10.1196/annals.1387.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cardiac Na+/Ca2+ exchanger 1 (NCX1) expression levels change under various pathophysiological conditions. However, its mechanism is unknown. We found that fluvastatin, an HMG-CoA reductase inhibitor, decreased NCX1 mRNA and protein by inhibiting a small G protein, RhoB, in H9c2 cardiomyoblasts. Conversely, lysophosphatidylcholine (LPC) increased NCX1 mRNA and protein by activating RhoB. The effect of LPC was mediated by geranylgeranylation but not farnesylation of RhoB. Furthermore, we also detected that activation of RhoB increased NCX1 mRNA stability. Our results suggest that RhoB is involved in modulation of cardiac NCX1 mRNA expression.
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Affiliation(s)
- Sachiko Maeda
- Department of Pharmacology, Fukushima Medical University, Fukushima 960-1295, Japan
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18
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Zuccaro P, Mombelli G, Calabresi L, Baldassarre D, Palmi I, Sirtori CR. Tolerability of statins is not linked to CYP450 polymorphisms, but reduced CYP2D6 metabolism improves cholesteraemic response to simvastatin and fluvastatin. Pharmacol Res 2007; 55:310-7. [PMID: 17289397 DOI: 10.1016/j.phrs.2006.12.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 12/14/2006] [Accepted: 12/18/2006] [Indexed: 10/23/2022]
Abstract
Statin therapy, although generally well tolerated, leads not infrequently to significant subjective and at times objective adverse effects (AEs), mainly of a muscular nature. The genetic background of these AEs is not clear and possibly side effects and lipid lowering efficacy may be linked. Aim of the study was a detailed evaluation of CYP450 and apolipoprotein E gene polymorphisms in two large series of age-sex matched patients with and without muscular side effects to statins. In a Clinical Institution specialised in lipid-lipoprotein disorders, 50 statin treated patients were selected, with subjective or objective statin-associated myopathy, evaluated using standardized forms. These were sex and age matched with 50 statin-treated patients from the same Clinic, without any subjective or objective complaints. DNA samples for the evaluation of CYP450 genetic polymorphisms and apo E genotypes were collected in order to assess correlations with both genetic polymorphisms and AEs, as well as with therapeutic efficacy. None of the assessed CYP450 polymorphisms appeared to be related to an increased incidence of AEs. The CYP2D6 *1/*4 and *4/4* poor metabolizer (PM) status was associated to a higher efficacy of statins metabolized by this system and, in addition, the apo E2 genotype was, in this series, linked to increased HDL-C levels after therapy. Patients with statin associated myopathy are not characterized by significantly different genotypes for the CYP450s responsible for statin metabolism. On the other hand, CYP2D6 PM status is associated to an increased efficacy of statins metabolized by this system.
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Affiliation(s)
- Piergiorgio Zuccaro
- Department of Drug Research and Evaluation, Italian National Institute of Health, Rome, Italy
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