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Regulation of P2X1 receptors by modulators of the cAMP effectors PKA and EPAC. Proc Natl Acad Sci U S A 2021; 118:2108094118. [PMID: 34508006 DOI: 10.1073/pnas.2108094118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2021] [Indexed: 11/18/2022] Open
Abstract
P2X1 receptors are adenosine triphosphate (ATP)-gated cation channels that are functionally important for male fertility, bladder contraction, and platelet aggregation. The activity of P2X1 receptors is modulated by lipids and intracellular messengers such as cAMP, which can stimulate protein kinase A (PKA). Exchange protein activated by cAMP (EPAC) is another cAMP effector; however, its effect on P2X1 receptors has not yet been determined. Here, we demonstrate that P2X1 currents, recorded from human embryonic kidney (HEK) cells transiently transfected with P2X1 cDNA, were inhibited by the highly selective EPAC activator 007-AM. In contrast, EPAC activation enhanced P2X2 current amplitude. The PKA activator 6-MB-cAMP did not affect P2X1 currents, but inhibited P2X2 currents. The inhibitory effects of EPAC on P2X1 were prevented by triple mutation of residues 21 to 23 on the amino terminus of P2X1 subunits to the equivalent amino acids on P2X2 receptors. Double mutation of residues 21 and 22 and single mutation of residue 23 also protected P2X1 receptors from inhibition by EPAC activation. Finally, the inhibitory effects of EPAC on P2X1 were also prevented by NSC23766, an inhibitor of Rac1, a member of the Rho family of small GTPases. These data suggest that EPAC is an important regulator of P2X1 and P2X2 receptors.
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2
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Coordination between Rac1 and Rab Proteins: Functional Implications in Health and Disease. Cells 2019; 8:cells8050396. [PMID: 31035701 PMCID: PMC6562727 DOI: 10.3390/cells8050396] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 02/07/2023] Open
Abstract
The small GTPases of the Rho family regulate many aspects of actin dynamics, but are functionally connected to many other cellular processes. Rac1, a member of this family, besides its known function in the regulation of actin cytoskeleton, plays a key role in the production of reactive oxygen species, in gene transcription, in DNA repair, and also has been proven to have specific roles in neurons. This review focuses on the cooperation between Rac1 and Rab proteins, analyzing how the coordination between these GTPases impact on cells and how alterations of their functions lead to disease.
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Marei H, Malliri A. Rac1 in human diseases: The therapeutic potential of targeting Rac1 signaling regulatory mechanisms. Small GTPases 2017; 8:139-163. [PMID: 27442895 PMCID: PMC5584733 DOI: 10.1080/21541248.2016.1211398] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 07/05/2016] [Accepted: 07/05/2016] [Indexed: 12/11/2022] Open
Abstract
Abnormal Rac1 signaling is linked to a number of debilitating human diseases, including cancer, cardiovascular diseases and neurodegenerative disorders. As such, Rac1 represents an attractive therapeutic target, yet the search for effective Rac1 inhibitors is still underway. Given the adverse effects associated with Rac1 signaling perturbation, cells have evolved several mechanisms to ensure the tight regulation of Rac1 signaling. Thus, characterizing these mechanisms can provide invaluable information regarding major cellular events that lead to aberrant Rac1 signaling. Importantly, this information can be utilized to further facilitate the development of effective pharmacological modulators that can restore normal Rac1 signaling. In this review, we focus on the pathological role of Rac1 signaling, highlighting the benefits and potential drawbacks of targeting Rac1 in a clinical setting. Additionally, we provide an overview of available compounds that target key Rac1 regulatory mechanisms and discuss future therapeutic avenues arising from our understanding of these mechanisms.
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Affiliation(s)
- Hadir Marei
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
| | - Angeliki Malliri
- Cell Signaling Group, Cancer Research UK Manchester Institute, The University of Manchester, Manchester, UK
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Quantitative Phosphoproteomics Reveals a Role for Collapsin Response Mediator Protein 2 in PDGF-Induced Cell Migration. Sci Rep 2017. [PMID: 28638064 PMCID: PMC5479788 DOI: 10.1038/s41598-017-04015-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The Platelet Derived Growth Factor (PDGF) family of ligands have well established functions in the induction of cell proliferation and migration during development, tissue homeostasis and interactions between tumours and stroma. However, the mechanisms by which these actions are executed are incompletely understood. Here we report a differential phosphoproteomics study, using a SILAC approach, of PDGF-stimulated mouse embryonic fibroblasts (MEFs). 116 phospho-sites were identified as up-regulated and 45 down-regulated in response to PDGF stimulation. These encompass proteins involved in cell adhesion, cytoskeleton regulation and vesicle-mediated transport, significantly expanding the range of proteins implicated in PDGF signalling pathways. Included in the down-regulated class was the microtubule bundling protein Collapsin Response Mediator Protein 2 (CRMP2). In response to stimulation with PDGF, CRMP2 was dephosphorylated on Thr514, an event known to increase CRMP2 activity. This was reversed in the presence of micromolar concentrations of the protein phosphatase inhibitor okadaic acid, implicating PDGF-induced activation of protein phosphatase 1 (PP1) in CRMP2 regulation. Depletion of CRMP2 resulted in impairment of PDGF-mediated cell migration in an in vitro wound healing assay. These results show that CRMP2 is required for PDGF-directed cell migration in vitro.
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Mottola G, Chatterjee A, Wu B, Chen M, Conte MS. Aspirin-triggered resolvin D1 attenuates PDGF-induced vascular smooth muscle cell migration via the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway. PLoS One 2017; 12:e0174936. [PMID: 28362840 PMCID: PMC5376330 DOI: 10.1371/journal.pone.0174936] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/17/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Resolvin D1 (RvD1) is a specialized pro-resolving lipid mediator that has been previously shown to attenuate vascular smooth muscle cell (VSMC) migration, a key process in the development of intimal hyperplasia. We sought to investigate the role of the cAMP/PKA pathway in mediating the effects of the aspirin-triggered epimer 17R-RvD1 (AT-RvD1) on VSMC migration. METHODS VSMCs were harvested from human saphenous veins. VSMCs were analyzed for intracellular cAMP levels and PKA activity after exposure to AT-RvD1. Platelet-derived growth factor (PDGF)-induced migration and cytoskeletal changes in VSMCs were observed through scratch, Transwell, and cell shape assays in the presence or absence of a PKA inhibitor (Rp-8-Br-cAMP). Further investigation of the pathways involved in AT-RvD1 signaling was performed by measuring Rac1 activity, vasodilator stimulated phosphoprotein (VASP) phosphorylation and paxillin translocation. Finally, we examined the role of RvD1 receptors (GPR32 and ALX/FPR2) in AT-RvD1 induced effects on VSMC migration and PKA activity. RESULTS Treatment with AT-RvD1 induced a significant increase in cAMP levels and PKA activity in VSMCs at 5 minutes and 30 minutes, respectively. AT-RvD1 attenuated PDGF-induced VSMC migration and cytoskeletal rearrangements. These effects were attenuated by the PKA inhibitor Rp-8-Br-cAMP, suggesting cAMP/PKA involvement. Treatment of VSMC with AT-RvD1 inhibited PDGF-stimulated Rac1 activity, increased VASP phosphorylation, and attenuated paxillin localization to focal adhesions; these effects were negated by the addition of Rp-8-Br-cAMP. The effects of AT-RvD1 on VSMC migration and PKA activity were attenuated by blocking ALX/FPR2, suggesting an important role of this G-protein coupled receptor. CONCLUSIONS Our results suggest that AT-RvD1 attenuates PDGF-induced VSMC migration via ALX/FPR2 and cAMP/PKA. Interference with Rac1, VASP and paxillin function appear to mediate the downstream effects of AT-RvD1 on VSMC migration.
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Affiliation(s)
- Giorgio Mottola
- Department of Surgery, Division of Vascular and Endovascular Surgery, Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
| | - Anuran Chatterjee
- Department of Surgery, Division of Vascular and Endovascular Surgery, Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Bian Wu
- Department of Surgery, Division of Vascular and Endovascular Surgery, Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Mian Chen
- Department of Surgery, Division of Vascular and Endovascular Surgery, Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Michael S. Conte
- Department of Surgery, Division of Vascular and Endovascular Surgery, Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
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Yan JF, Huang WJ, Zhao JF, Fu HY, Zhang GY, Huang XJ, Lv BD. The platelet-derived growth factor receptor/STAT3 signaling pathway regulates the phenotypic transition of corpus cavernosum smooth muscle in rats. PLoS One 2017; 12:e0172191. [PMID: 28245285 PMCID: PMC5330473 DOI: 10.1371/journal.pone.0172191] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 02/01/2017] [Indexed: 01/09/2023] Open
Abstract
Erectile dysfunction (ED) is a common clinical disease that is difficult to treat. We previously found that hypoxia modulates the phenotype of primary corpus cavernosum smooth muscle cells (CCSMCs) in rats, but the underlying molecular mechanism is still unknown. Platelet-derived growth factor receptor (PDGFR)-related signaling pathways are correlated with cell phenotypic transition, but research has been focused more on vascular smooth muscle and tracheal smooth muscle and less on CCSMCs. Here, we investigated the role of PDGFR-related signaling pathways in penile CCSMCs, which were successfully isolated from rats and cultured in vitro. PDGF-BB at 5, 10, or 20 ng/ml altered CCSMC morphology from the original elongated, spindle shape to a broader shape and promoted the synthetic phenotype and expression of the related proteins vimentin and collagen-I, while inhibiting the contractile phenotype and expression of the related proteins smooth muscle (SM) α-actin (α-SMA) and desmin. Inhibition of PDGFR activity via siRNA or the PDGFR inhibitor crenolanib inhibited vimentin and collagen-I expression, increased α-SMA and desmin expression, and considerably inhibited serine-threonine protein kinase (AKT) and signal transducer and activator of transcription 3 (STAT3) phosphorylation. STAT3 knockdown promoted the contractile phenotype, inhibited vimentin and collagen-I expression, and increased α-SMA and desmin expression, whereas AKT knockdown did not affect phenotype-associated proteins. STAT3 overexpression in CCSMC cells weakened the suppressive effect of PDGFR inhibition on the morphology and phenotypic transformation induced by PDGF-BB. Through activation of the PDGFR/STAT3 signaling pathway, PDGF promoted the synthetic phenotype transition; thus, regulation of this pathway might contribute to ED therapy.
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Affiliation(s)
- Jun-Feng Yan
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Wen-Jie Huang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jian-Feng Zhao
- Department of Urology, The Second Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
| | - Hui-Ying Fu
- Andrology Laboratory on Integration of Chinese and Western Medicine, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine, Hangzhou, China
- Central Laboratory, The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Gao-Yue Zhang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, China
| | - Xiao-Jun Huang
- Department of Urology, The Second Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
| | - Bo-Dong Lv
- Department of Urology, The Second Affiliated Hospital, Zhejiang Chinese Medical University, Hangzhou, China
- Andrology Laboratory on Integration of Chinese and Western Medicine, Zhejiang Provincial Key Laboratory of Traditional Chinese Medicine, Hangzhou, China
- * E-mail:
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7
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Mesenchymal Stem Cells Induce Directional Migration of Invasive Breast Cancer Cells through TGF-β. Sci Rep 2015; 5:16941. [PMID: 26585689 PMCID: PMC4653660 DOI: 10.1038/srep16941] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 10/14/2015] [Indexed: 12/24/2022] Open
Abstract
Mesenchymal stem cells (MSCs) are recruited to the tumor microenvironment and influence tumor progression; however, how MSCs induce the invasion of cancer cells is not completely understood. Here, we used a 3D coculture model to determine how MSCs affect the migration of invasive breast cancer cells. Coculture with MSCs increases the elongation, directional migration, and traction generation of breast cancer cells. MSC-induced directional migration directly correlates with traction generation and is mediated by transforming growth factor β (TGF-β) and the migratory proteins rho-associated kinase, focal adhesion kinase, and matrix metalloproteinases. Treatment with MSC conditioned media or recombinant TGF-β1 elicits a similar migration response to coculture. Taken together, this work suggests TGF-β is secreted by MSCs, leading to force-dependent directional migration of invasive breast cancer cells. These pathways may be potential targets for blocking cancer cell invasion and subsequent metastasis.
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8
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Thymic stromal lymphopoietin induces migration in human airway smooth muscle cells. Sci Rep 2014; 3:2301. [PMID: 23892442 PMCID: PMC3725475 DOI: 10.1038/srep02301] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 07/10/2013] [Indexed: 02/06/2023] Open
Abstract
Airway remodeling due to increased airway smooth muscle (ASM) mass, likely due to enhanced migration and proliferation, has been shown to be highly associated with decline in lung function in asthma. Thymic stromal lymphopoietin (TSLP) is an IL-7-like, pro-allergic cytokine that has been shown to be necessary and sufficient for the development of allergic asthma. Human ASM (HASM) cells express TSLP receptor (TSLPR), the activation of which leads to enhanced release of proinflammatory mediators such as IL-6, CCL11/eotaxin-1, and CXCL8/IL-8. We show here that TSLP induces HASM cell migration through STAT3 activation since lentiviral-shRNA inhibition of STAT3 abrogated the TSLP-induced cell migration. Moreover, TSLP induced multiple cytoskeleton changes in HASM cells such as actin polymerization, cell polarization, and activation of small GTPase Rac1. Collectively, our data suggest a pro-migratory function of TSLP in ASM remodeling and provides better rationale for targeting TSLP/TSLPR pathway for therapeutic approaches in allergic asthma.
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Rahman A, Davis B, Lövdahl C, Hanumaiah VT, Feil R, Brakebusch C, Arner A. The small GTPase Rac1 is required for smooth muscle contraction. J Physiol 2013; 592:915-26. [PMID: 24297853 DOI: 10.1113/jphysiol.2013.262998] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The role of the small GTP-binding protein Rac1 in smooth muscle contraction was examined using small molecule inhibitors (EHT1864, NSC23766) and a novel smooth muscle-specific, conditional, Rac1 knockout mouse strain. EHT1864, which affects nucleotide binding and inhibits Rac1 activity, concentration-dependently inhibited the contractile responses induced by several different modes of activation (high-K+, phenylephrine, carbachol and protein kinase C activation by phorbol-12,13-dibutyrate) in several different visceral (urinary bladder, ileum) and vascular (mesenteric artery, saphenous artery, aorta) smooth muscle tissues. This contractile inhibition was associated with inhibition of the Ca2+ transient. Knockout of Rac1 (with a 50% loss of Rac1 protein) lowered active stress in the urinary bladder and the saphenous artery consistent with a role of Rac1 in facilitating smooth muscle contraction. NSC23766, which blocks interaction between Rac1 and some guanine nucleotide exchange factors, specifically inhibited the α1 receptor responses (phenylephrine) in vascular tissues and potentiated prostaglandin F2α and thromboxane (U46619) receptor responses. The latter potentiating effect occurred at lowered intracellular [Ca2+]. These results show that Rac1 activity is required for active contraction in smooth muscle, probably via enabling an adequate Ca2+ transient. At the same time, specific agonists recruit Rac1 signalling via upstream modulators, resulting in either a potentiation of contraction via Ca2+ mobilization (α1 receptor stimulation) or an attenuated contraction via inhibition of Ca2+ sensitization (prostaglandin and thromboxane receptors).
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Affiliation(s)
- Awahan Rahman
- Department of Physiology and Pharmacology, Karolinska Institutet, von Eulers väg 8, SE 171 77 Stockholm, Sweden.
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10
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Daugaard M, Nitsch R, Razaghi B, McDonald L, Jarrar A, Torrino S, Castillo-Lluva S, Rotblat B, Li L, Malliri A, Lemichez E, Mettouchi A, Berman JN, Penninger JM, Sorensen PH. Hace1 controls ROS generation of vertebrate Rac1-dependent NADPH oxidase complexes. Nat Commun 2013; 4:2180. [PMID: 23864022 PMCID: PMC3759041 DOI: 10.1038/ncomms3180] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 06/21/2013] [Indexed: 02/04/2023] Open
Abstract
The Hace1-HECT E3 ligase is a tumor suppressor that ubiquitylates the activated GTP-bound form of the Rho family GTPase Rac1, leading to Rac1 proteasomal degradation. Here we show that, in vertebrates, Hace1 targets Rac1 for degradation when Rac1 is localized to the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase holoenzyme. This event blocks de novo reactive oxygen species generation by Rac1-dependent NADPH oxidases, and thereby confers cellular protection from reactive oxygen species-induced DNA damage and cyclin D1-driven hyper-proliferation. Genetic inactivation of Hace1 in mice or zebrafish, as well as Hace1 loss in human tumor cell lines or primary murine or human tumors, leads to chronic NADPH oxidase-dependent reactive oxygen species elevation, DNA damage responses and enhanced cyclin D1 expression. Our data reveal a conserved ubiquitin-dependent molecular mechanism that controls the activity of Rac1-dependent NADPH oxidase complexes, and thus constitutes the first known example of a tumor suppressor protein that directly regulates reactive oxygen species production in vertebrates.
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Affiliation(s)
- Mads Daugaard
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Roberto Nitsch
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr Bohrgasse 3, Vienna 1030 Austria
| | - Babak Razaghi
- Department of Pediatrics, Dalhousie University and IWK Health Centre, Halifax, Nova Scotia B3K 6R8, Canada
| | - Lindsay McDonald
- Department of Pediatrics, Dalhousie University and IWK Health Centre, Halifax, Nova Scotia B3K 6R8, Canada
| | - Ameer Jarrar
- Department of Pediatrics, Dalhousie University and IWK Health Centre, Halifax, Nova Scotia B3K 6R8, Canada
| | - Stéphanie Torrino
- Equipe labellisée Ligue Contre Le Cancer, U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Université de Nice-Sophia-Antipolis, 8 06204 Nice, France
| | - Sonia Castillo-Lluva
- Cell Signalling Group, Cancer Research UK Paterson Institute for Cancer Research, The University of Manchester, Manchester, M20 4BX, UK
| | - Barak Rotblat
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L3, Canada
| | - Liheng Li
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L3, Canada
| | - Angeliki Malliri
- Cell Signalling Group, Cancer Research UK Paterson Institute for Cancer Research, The University of Manchester, Manchester, M20 4BX, UK
| | - Emmanuel Lemichez
- Equipe labellisée Ligue Contre Le Cancer, U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Université de Nice-Sophia-Antipolis, 8 06204 Nice, France
| | - Amel Mettouchi
- Equipe labellisée Ligue Contre Le Cancer, U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Université de Nice-Sophia-Antipolis, 8 06204 Nice, France
| | - Jason N. Berman
- Department of Pediatrics, Dalhousie University and IWK Health Centre, Halifax, Nova Scotia B3K 6R8, Canada
| | - Josef M. Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Dr Bohrgasse 3, Vienna 1030 Austria
| | - Poul H. Sorensen
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Talukder MAH, Elnakish MT, Yang F, Nishijima Y, Alhaj MA, Velayutham M, Hassanain HH, Zweier JL. Cardiomyocyte-specific overexpression of an active form of Rac predisposes the heart to increased myocardial stunning and ischemia-reperfusion injury. Am J Physiol Heart Circ Physiol 2012; 304:H294-302. [PMID: 23161879 DOI: 10.1152/ajpheart.00367.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The GTP-binding protein Rac regulates diverse cellular functions including activation of NADPH oxidase, a major source of superoxide production (O(2)(·-)). Rac1-mediated NADPH oxidase activation is increased after myocardial infarction (MI) and heart failure both in animals and humans; however, the impact of increased myocardial Rac on impending ischemia-reperfusion (I/R) is unknown. A novel transgenic mouse model with cardiac-specific overexpression of constitutively active mutant form of Zea maize Rac D (ZmRacD) gene has been reported with increased myocardial Rac-GTPase activity and O(2)(·-) generation. The goal of the present study was to determine signaling pathways related to increased myocardial ZmRacD and to what extent hearts with increased ZmRacD proteins are susceptible to I/R injury. The effect of myocardial I/R was examined in young adult wild-type (WT) and ZmRacD transgenic (TG) mice. In vitro reversible myocardial I/R for postischemic cardiac function and in vivo regional myocardial I/R for MI were performed. Following 20-min global ischemia and 45-min reperfusion, postischemic cardiac contractile function and heart rate were significantly reduced in TG hearts compared with WT hearts. Importantly, acute regional myocardial I/R (30-min ischemia and 24-h reperfusion) caused significantly larger MI in TG mice compared with WT mice. Western blot analysis of cardiac homogenates revealed that increased myocardial ZmRacD gene expression is associated with concomitant increased levels of NADPH oxidase subunit gp91(phox), O(2)(·-), and P(21)-activated kinase. Thus these findings provide direct evidence that increased levels of active myocardial Rac renders the heart susceptible to increased postischemic contractile dysfunction and MI following acute I/R.
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Affiliation(s)
- M A Hassan Talukder
- Dorothy M. Davis Heart and Lung Research Institute, Division of Cardiovascular Medicine
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12
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Gabunia K, Jain S, England RN, Autieri MV. Anti-inflammatory cytokine interleukin-19 inhibits smooth muscle cell migration and activation of cytoskeletal regulators of VSMC motility. Am J Physiol Cell Physiol 2011; 300:C896-906. [PMID: 21209363 DOI: 10.1152/ajpcell.00439.2010] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vascular smooth muscle cell (VSMC) migration is an important cellular event in multiple vascular diseases, including atherosclerosis, restenosis, and transplant vasculopathy. Little is known regarding the effects of anti-inflammatory interleukins on VSMC migration. This study tested the hypothesis that an anti-inflammatory Th2 interleukin, interleukin-19 (IL-19), could decrease VSMC motility. IL-19 significantly decreased platelet-derived growth factor (PDGF)-stimulated VSMC chemotaxis in Boyden chambers and migration in scratch wound assays. IL-19 significantly decreased VSMC spreading in response to PDGF. To determine the molecular mechanism(s) for these cellular effects, we examined the effect of IL-19 on activation of proteins that regulate VSMC cytoskeletal dynamics and locomotion. IL-19 decreased PDGF-driven activation of several cytoskeletal regulatory proteins that play an important role in smooth muscle cell motility, including heat shock protein-27 (HSP27), myosin light chain (MLC), and cofilin. IL-19 decreased PDGF activation of the Rac1 and RhoA GTPases, important integrators of migratory signals. IL-19 was unable to inhibit VSMC migration nor was able to inhibit activation of cytoskeletal regulatory proteins in VSMC transduced with a constitutively active Rac1 mutant (RacV14), suggesting that IL-19 inhibits events proximal to Rac1 activation. Together, these data are the first to indicate that IL-19 can have important inhibitory effects on VSMC motility and activation of cytoskeletal regulatory proteins. This has important implications for the use of anti-inflammatory cytokines in the treatment of vascular occlusive disease.
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Affiliation(s)
- Khatuna Gabunia
- Dept. of Physiology, Independence Blue Cross Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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13
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Jiang C, Zhang H, Zhang W, Kong W, Zhu Y, Zhang H, Xu Q, Li Y, Wang X. Homocysteine promotes vascular smooth muscle cell migration by induction of the adipokine resistin. Am J Physiol Cell Physiol 2009; 297:C1466-76. [PMID: 19828833 DOI: 10.1152/ajpcell.00304.2009] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Adipokines may represent a mechanism linking insulin resistance to cardiovascular disease. We showed previously that homocysteine (Hcy), an independent risk factor for cardiovascular disease, can induce the expression and secretion of resistin, a novel adipokine, in vivo and in vitro. Since vascular smooth muscle cell (VSMC) migration is a key event in vascular disease, we hypothesized that adipocyte-derived resistin is involved in Hcy-induced VSMC migration. To confirm our hypothesis, Sprague-Dawley rat aortic SMCs were cocultured with Hcy-stimulated primary rat epididymal adipocytes or treated directly with increasing concentrations of resistin for up to 24 h. Migration of VSMCs was investigated. Cytoskeletal structure and cytoskeleton-related proteins were also detected. The results showed that Hcy (300-500 microM) increased migration significantly in VSMCs cocultured with adipocytes but not in VSMC cultured alone. Resistin alone also significantly increased VSMC migration in a time- and concentration-dependent manner. Resistin small interfering RNA (siRNA) significantly attenuated VSMC migration in the coculture system, which indicated that adipocyte-derived resistin mediates Hcy-induced VSMC migration. On cell spreading assay, resistin induced the formation of focal adhesions near the plasma membrane, which suggests cytoskeletal rearrangement via an alpha(5)beta(1)-integrin-focal adhesion kinase/paxillin-Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway. Our data demonstrate that Hcy promotes VSMC migration through a paracrine or endocrine effect of adipocyte-derived resistin, which provides further evidence of the adipose-vascular interaction in metabolic disorders. The migratory action exerted by resistin on VSMCs may account in part for the increased incidence of restenosis in diabetic patients.
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Affiliation(s)
- Changtao Jiang
- Dept. of Physiology and Pathophysiology, Peking Univ., Beijing, People's Republic of China
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14
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Mercure MZ, Ginnan R, Singer HA. CaM kinase II delta2-dependent regulation of vascular smooth muscle cell polarization and migration. Am J Physiol Cell Physiol 2008; 294:C1465-75. [PMID: 18385282 DOI: 10.1152/ajpcell.90638.2007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Previous studies indicate involvement of the multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII) in vascular smooth muscle (VSM) cell migration. In the present study, molecular loss-of-function studies were used specifically to assess the role of the predominant CaMKII delta2 isoform on VSM cell migration using a scratch wound healing assay. Targeted CaMKII delta2 knockdown using siRNA or inhibition of activity by overexpressing a kinase-negative mutant resulted in attenuation of VSM cell migration. Temporal and spatial assessments of kinase autophosphorylation indicated rapid and transient activation in response to wounding, in addition to a sustained activation in the leading edge of migrating and spreading cells. Furthermore, siRNA-mediated suppression of CaMKII delta2 resulted in the inhibition of wound-induced Rac activation and Golgi reorganization, and disruption of leading edge morphology, indicating an important function for CaMKII delta2 in regulating VSM cell polarization. Numerous previous reports link activation of CaMKII to ERK1/2 signaling in VSM. Wound-induced ERK1/2 activation was also found to be dependent on CaMKII; however, ERK activity did not account for effects of CaMKII in regulating Golgi polarization, indicating alternative mechanisms by which CaMKII affects the complex events involved in cell migration. Wounding a VSM cell monolayer results in CaMKII delta2 activation, which positively regulates VSM cell polarization and downstream signaling, including Rac and ERK1/2 activation, leading to cell migration.
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Affiliation(s)
- Melissa Z Mercure
- Center for Cardiovascular Sciences, Albany Medical College, Albany, NY 12208, USA
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Abstract
Migration of smooth muscle cells is a process fundamental to development of hollow organs, including blood vessels and the airways. Migration is also thought to be part of the response to tissue injury. It has also been suggested to contribute to airways remodeling triggered by chronic inflammation. In both nonmuscle and smooth muscle cells numerous external signaling molecules and internal signal transduction pathways contribute to cell migration. The review includes evidence for the functional significance of airway smooth muscle migration, a summary of promigratory and antimigratory agents, and summaries of important signaling pathways mediating migration. Important signaling pathways and effector proteins described include small G proteins, phosphatidylinositol 3-kinases (PI3-K), Rho activated protein kinase (ROCK), p21-activated protein kinases (PAK), Src family tyrosine kinases, and mitogen-activated protein kinases (MAPK). These signaling modules control multiple critical effector proteins including actin nucleating, capping and severing proteins, myosin motors, and proteins that remodel microtubules. Actin filament remodeling, focal contact remodeling and propulsive force of molecular motors are all coordinated to move cells along gradients of chemical cues, matrix adhesiveness, or matrix stiffness. Airway smooth muscle cell migration can be modulated in vitro by drugs commonly used in pulmonary medicine including beta-adrenergic agonists and corticosteroids. Future studies of airway smooth muscle cell migration may uncover novel targets for drugs aimed at modifying airway remodeling.
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Tian Y, Autieri MV. Cytokine expression and AIF-1-mediated activation of Rac2 in vascular smooth muscle cells: a role for Rac2 in VSMC activation. Am J Physiol Cell Physiol 2007; 292:C841-9. [PMID: 16987989 DOI: 10.1152/ajpcell.00334.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Allograft inflammatory factor-1 (AIF-1) is a cytoplasmic, calcium-binding, inflammation-responsive scaffold protein involved in vascular smooth muscle cell (VSMC) migration and proliferation. The objective of this study is to characterize AIF-1 functional protein interactions that may regulate VSMC activation. Through use of a bacterial two-hybrid screen, we identified a molecular interaction between AIF-1 and the small GTPase, Rac2, which was verified by pull-down and colocalization experiments. This was unexpected in that Rac2 expression had been considered to be restricted to hematopoietic cells. The Rac2/AIF-1 interaction is functional, in that a loss-of-function, point-mutated AIF-1 does not interact with Rac2; Rac2 colocalizes with AIF-1 in the cytoplasm of VSMC and cotranslocates to lamellopodia upon platelet-derived growth factor stimulation; and AIF-1 expression in VSMC leads to Rac2 activation. Because Rac2 function in VSMC had not been described, we focused on characterization of its function in these cells. Rac2 protein expression in VSMC is inducible by inflammatory cytokines, and Rac2 activation in VSMC is also responsive to inflammatory cytokines. Rac2 expression and activation patterns differ from the ubiquitously expressed Rac1. We hypothesized that Rac2 participates in VSMC activation. Retroviral overexpression of Rac2 in primary VSMC leads to increased migration, activation of the NADPH oxidation cascade, and increased activation of the Rac2 effector protein Pak1 and its proximal effectors, ERK1/2, and p38 (P < 0.05 for all). The major points of this study indicate a functional interaction between AIF-1 and Rac2 in VSMC leading to Rac2 activation and a potential function for Rac2 in inflammation-driven VSMC response to injury.
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Affiliation(s)
- Ying Tian
- Dept. of Physiology, Cardiovascular Research Center, Temple Univ. School of Medicine, Philadelphia, PA 10140, USA
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Ceacareanu AC, Ceacareanu B, Zhuang D, Chang Y, Ray RM, Desai L, Chapman KE, Waters CM, Hassid A. Nitric oxide attenuates IGF-I-induced aortic smooth muscle cell motility by decreasing Rac1 activity: essential role of PTP-PEST and p130cas. Am J Physiol Cell Physiol 2005; 290:C1263-70. [PMID: 16354758 DOI: 10.1152/ajpcell.00241.2005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent data support the hypothesis that reactive oxygen species (ROS) play a central role in the initiation and progression of vascular diseases. An important vasoprotective function related to the regulation of ROS levels appears to be the antioxidant capacity of nitric oxide (NO). We previously reported that treatment with NO decreases phosphotyrosine levels of adapter protein p130(cas) by increasing protein tyrosine phosphatase-proline, glutamate, serine, and threonine sequence protein (PTP-PEST) activity, which leads to the suppression of agonist-induced H(2)O(2) elevation and motility in cultured rat aortic smooth muscle cells (SMCs). The present study was performed to investigate the hypotheses that 1) IGF-I increases the activity of the small GTPase Rac1 as well as H(2)O(2) levels and 2) NO suppresses IGF-I-induced H(2)O(2) elevation by decreasing Rac1 activity via increased PTP-PEST activity and dephosphorylation of p130(cas). We report that IGF-I induces phosphorylation of p130(cas) and activation of Rac1 and that NO attenuates these effects. The effects of NO are mimicked by the overexpression of PTP-PEST or dominant-negative (dn)-p130(cas) and antagonized by the expression of dn-PTP-PEST or p130(cas). We conclude that IGF-I induces rat aortic SMC motility by increasing phosphotyrosine levels of p130(cas) and activating Rac1 and that NO decreases motility by activating PTP-PEST, inducing dephosphorylating p130(cas), and decreasing Rac1 activity. Decreased Rac1 activity lowers intracellular H(2)O(2) levels, thus attenuating cell motility.
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Affiliation(s)
- Alice-Corina Ceacareanu
- Department of Physiology, University of Tennessee Health Science Center, 894 Union Ave., Memphis, 38163, USA
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Kappert K, Caglayan E, Huntgeburth M, Bäumer AT, Sparwel J, Uebel M, Rosenkranz S. 17Beta-estradiol attenuates PDGF signaling in vascular smooth muscle cells at the postreceptor level. Am J Physiol Heart Circ Physiol 2005; 290:H538-46. [PMID: 16227346 DOI: 10.1152/ajpheart.00240.2005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Estrogens are known to display significant vasoprotective effects in premenopausal women. PDGF is an important mediator of vascular smooth muscle cell (VSMC) migration and proliferation, and thus atherogenesis. We analyzed the effects of 17beta-estradiol (E2) on beta-PDGF receptor (beta-PDGFR) expression/activation and PDGF-dependent VSMC proliferation, migration, and downstream signaling events. Pretreatment of VSMCs with E2 (0.3 microM-0.1 mM) for 24 h concentration-dependently inhibited PDGF-induced proliferation and migration up to 85.5 +/- 15.8% and 79.4 +/- 9.8%, respectively (both P < 0.05). These effects were prevented by coincubation with the ER antagonist ICI-182780. E2 did not alter beta-PDGFR expression, nor did it impair the ligand-induced tyrosine phosphorylation of the beta-PDGFR and consecutive binding of the receptor-associated signaling molecules Src homology region 2-containing phosphatase-2, PLC-gamma, phosphatidylinositol 3-kinase, and RasGAP. Thus estrogens inhibited PDGF-induced cellular responses at the postreceptor level. Although stimulation of VSMCs with PDGF-BB led to a transient increase of rac-1 activity, pretreatment with E2 for 24 h concentration-dependently inhibited PDGF-induced rac-1 activation. Furthermore, inhibition of rac-1 by Clostridium sordellii lethal toxin or overexpression of dominant-negative rac-1 (rac-N17) significantly inhibited PDGF-induced VSMC migration, indicating that rac-1 activity is essential for PDGF-dependent cellular responses. E2 did not further reduce PDGF-induced migration in rac-N17-overexpressing cells, suggesting that it diminishes VSMC migration by altering rac-1 activity. We conclude that E2 attenuates PDGF-dependent cellular functions of VSMCs downstream of the beta-PDGFR via inhibition of rac-1. These observations offer a molecular explanation for the vasoprotective effects of estrogens.
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MESH Headings
- Animals
- Cell Cycle/drug effects
- Cell Movement/physiology
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- Chemotaxis/drug effects
- Chemotaxis/physiology
- Estradiol/pharmacology
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/physiology
- Platelet-Derived Growth Factor/metabolism
- Rats
- Rats, Inbred WKY
- Receptor, Platelet-Derived Growth Factor beta/metabolism
- Receptors, Estrogen/physiology
- Signal Transduction/drug effects
- rac1 GTP-Binding Protein/metabolism
- rac1 GTP-Binding Protein/physiology
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Affiliation(s)
- Kai Kappert
- Klinik III für Innere Medizin der Universität zu Köln, Kerpener Str. 62, 50924 Köln, Germany
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Gregg D, Rauscher FM, Goldschmidt-Clermont PJ. Rac regulates cardiovascular superoxide through diverse molecular interactions: more than a binary GTP switch. Am J Physiol Cell Physiol 2003; 285:C723-34. [PMID: 12958025 DOI: 10.1152/ajpcell.00230.2003] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The small G protein Rac has been implicated in multiple cardiovascular processes. Rac has two major functions: 1) it regulates the organization of the actin cytoskeleton, and 2) it controls the activity of the key enzyme complex NADPH oxidase to control superoxide production in both phagocytes and nonphagocytic cells. In phagocytes, superoxide derived from NADPH has a bactericidal function, whereas Rac-derived superoxide in the cardiovascular system has a diverse array of functions that have recently been a subject of intense interest. Rac is differentially activated by cellular receptors coupled to distinct Rac-activating adapter molecules, with each leading to pathway-specific arrays of downstream effects. Thus it may be important to investigate not just whether Rac is activated but also where, how, and for what effector. An understanding of the biochemical functions of Rac and its effectors lays the groundwork for a dissection of the exact array of effects produced by Rac in common cardiovascular processes, including cardiac and vascular hypertrophy, hypertension, leukocyte migration, platelet biology, and atherosclerosis. In addition, investigation of the spatiotemporal regulation of both Rac activation and consequent superoxide generation may produce new insights into the development of targeted antioxidant therapies for cardiovascular disease and enhance our understanding of important cardiovascular drugs, including angiotensin II antagonists and statins, that may depend on Rac modulation for their effect.
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Affiliation(s)
- David Gregg
- Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
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Campbell M, Allen WE, Silversides JA, Trimble ER. Glucose-induced phosphatidylinositol 3-kinase and mitogen-activated protein kinase-dependent upregulation of the platelet-derived growth factor-beta receptor potentiates vascular smooth muscle cell chemotaxis. Diabetes 2003; 52:519-26. [PMID: 12540630 DOI: 10.2337/diabetes.52.2.519] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The aim of this study was to investigate the effects of elevated D-glucose concentrations on vascular smooth muscle cell (VSMC) expression of the platelet-derived growth factor (PDGF)beta receptor and VSMC migratory behavior. Immunoprecipitation, immunofluorescent staining, and RT-PCR of human VSMCs showed that elevated D-glucose induced an increase in the PDGFbeta receptor that was inhibited by phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathway inhibitors. Exposure to 25 mmol/l D-glucose (HG) induced increased phosphorylation of protein kinase B (PKB) and extracellular-regulated kinase (ERK). All HG chemotaxis assays (with either 10 days' preincubation in HG or no preincubation) in a FCS or PDGF-BB gradient showed positive chemotaxis, whereas those in 5 mmol/l D-glucose did not. Assays were also run with concentrations ranging from 5 to 25 mmol/l D-glucose. Chemotaxis was induced at concentrations > or =9 mmol/l D-glucose. An anti-PDGFbeta receptor antibody inhibited glucose-potentiated VSMC chemotaxis, as did the inhibitors for the PI3K and MAPK pathways. This study has shown that small increases in D-glucose concentration, for a short period, increase VSMC expression of the PDGFbeta receptor and VSMC sensitivity to chemotactic factors in serum, leading to altered migratory behavior in vitro. It is probable that similar processes occur in vivo with glucose-enhanced chemotaxis of VSMCs, operating through PDGFbeta receptor-operated pathways, contributing to the accelerated formation of atheroma in diabetes.
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Affiliation(s)
- Malcolm Campbell
- Department of Clinical Biochemistry, Queen's University, Belfast, UK
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